Aikyam-Lab/Synoptic-Bench huggingface dataset:
The CAMs continue to show that a cold front will move slowly east across the area from this afternoon into tonight. The highest PMM is across west-central Wisconsin.
In its wake, brief ridging will commence through the morning ahead of the diving H500 trough rotating across the western high plains and down the Llano Estacado later this morning. This feature is part of the larger extended upper trough from the Canadian Prairies, south. With weaker flow, the Northern Plains portion of the upper trough will sweep toward the region by midday. Ahead, modest moisture through the low to mid levels will support scattered showers given modest forcing for ascent with the associated weak surface boundary.
On tab for today, a cloudy day as an area of low pressure is expected to move across Southeastern U. with a cold front extending from northern Florida into the Gulf of Mexico increasing moisture and instability across our forecast area. The threat for severe weather remains on the low side (level 1 of 5) , SPC have a Marginal Risk across the interior and Tampa Bay northward.
322 AM EDT Fri Apr 28 2023 Current surface analysis reveals weak low pressure centered near west-central KY with associated cold front extending SSW through TN and MS. Otherwise to our south, an area of showers with embedded thunder has developed ahead of and along the cold front across central TN. A fairly large upper level trough will dig into the Midwest and Great Lakes region over the weekend, and gradually occlude and wrap up into a broad upper level low (ULL). A surface frontal boundary associated with the digging trough will pass through the area Saturday, and we may see some light shower along and ahead of the front with very minimal chances for storms given very weak instability.
Main area of concern in the mid-state continues to be south of I-40 and west of I-65 as instability has increased to 500-700 J/Kg over the last several hours due to the cold temperatures aloft associated with the upper low over the mid-Mississippi valley. to the lower 60s southwest. Shear values are on the lower end for this time of year, so it will take a healthy storm to generate some winds.
Drier and cooler air will filter into western Kansas today with strong north winds. Warmer weather will arrive Saturday, with a westerly to northwesterly downslope flow pattern ahead of a weak cold front, allowing afternoon readings to reach into the lower to mid 70s.
1126 PM CDT Thu Apr 27 2023 As the upper level trough over the region weakens and lifts out into the Ohio Valley, scattered showers and isolated storms will continue to slide east and taper off late tonight. The next trough currently over the Northern Plains will continue to deepen and drop south into the Southern Plains over the next 24 to 36 hours. In the meantime, expect dry and slightly warmer conditions on Friday with highs in the mid 60s to low 70s. By Friday night, as the trough over the Southern Plains begins to slide east across the lower Mississippi River Valley, it will drag a weak cold front through the area, beginning late Friday evening through Saturday.
This will be brought about by an upper trough digging in across Minnesota. An attendant jet streak wrapping around the digging trough will yield increasing rain chances across eastern North Dakota by way of a preferential left exit region and area of divergence aloft. This rain shower activity will likely linger throughout the day on Saturday as the upper trough becomes blocked over the western Great Lakes.
Discussion: Troughing at 500 MB will prevail through the short term across the Upper Midwest, A 500 MB trough will lift from Arkansas across Missouri and into Illinois tonight with mainly high clouds spilling into the area. Low temperatures on Friday morning will be noticeably warmer with lows between 43 to 48 degrees from north to south across the area. The better moisture and precipitation is forecast along and behind the cold front and result in around 20 percent chances to the northwest of Cedar Rapids. High temperatures on Friday will range from the upper 60s along and north of Highway 30 to the lower 70s south. Cooler this weekend.
The NAM, RAP, and GFS model soundings all indicate a rather dry air mass in place between these two areas of precipitation, so it will take some time before any precipitation from the cold front materializes once the column saturates from the top-down. CAMs are indicating that rain showers will develop along the cold front, likely not until later this evening or even after midnight tonight into early Saturday morning. Instability appears to be pretty modest, with some guidance indicating up to a few hundred J/kg of most-unstable CAPE across our far northwestern areas as the cold front moves in. With increasing cloud cover tonight along the cold front, temperatures will dip only to the lower to middle 40s.
Going into the overnight, we'll see quiet weather conditions in the wake of the trough, but high boundary layer RH and light wind could support some fog. /EC/ Friday night through Saturday night: Within continued broader mid/upper troughing, another more pronounced wave and cutoff upper low will swing into the Deep South Saturday into Saturday night. Nevertheless, rain chances will increase by Saturday afternoon and evening as the upper low moves overhead. If sufficient low level warming and moisture recovery were to occur during the daytime Saturday, steeper lapse rates in the vicinity of the upper low could initiate a few stronger storms. Then, during the night, a corridor of locally heavy rain may materialize under a deformation zone along the track of the upper low.
A weather disturbance passing by to our east tonight will drag a cold front through the area - bringing breezy north winds to much of Lincoln, Clark, Mohave, and eastern San Bernardino counties overnight into Friday. The hottest temperatures of the season will occur this weekend as a strong ridge builds over the west coast. At 1200, temperatures were about 5-9 degrees warmer than 24 hours ago with Las Vegas currently running 8 degrees warmer than yesterday. Persistent ridging over the Western US will allow for afternoon temperatures around 15+ degrees above normal over the weekend.
Current WV imagery and upper air analysis depicts a broad upper trof over the midwest with upper ridge building over the west coast. Upper ridge builds into the region through the weekend. Strengthening upper low over the Great Lakes stalls out and keeps the ridge from progressing eastward through the early week.
High pressure will build and gradually shift into western portions of the state through tomorrow. We will be above pretty much at all elevations, even on the highest peaks like Borah and such. Highest elevations of the central mountains and along the Montana border will be "cooler" with mid 40s and 50s. We will likely see only 50-60 around Bear Lake as the massive snowpack is still helping to keep temperatures a bit cooler.
Upper-level trough to deepen into a closed low across northeast Texas on Saturday and slowly migrate east into Mississippi by Saturday night leading to a continued unsettled weather pattern characterized by mostly cloudy skies and increased rain chances. Rainfall totals of 1 to 2 inches may be possible ahead of this low across the I-30 through Saturday with lesser values elsewhere. /05/ (Saturday Night through Friday) By sunset Saturday the upper low will over our LA Parishes, moving across the MS River during the mid to late evening.
WIth southeast progression of upper trough this morning, cold front expected to pick up momentum and extend from southwest Oklahoma/western north Texas into central Oklahoma by early afternoon. While overall instability will be lacking, cold temperatures aloft associated with mentioned trough will move over the region and yield some elevated instability. Potential for severe storms will be confined mainly to far southeast portions of our forecast where higher quality h2o and warmer boundary layer will yield greater instability late this afternoon and evening. Cooler and breezy conditions can be expected across the region behind the front tonight into Saturday. Residual post frontal showers expected to linger over far southeast Oklahoma Saturday morning as upper trough slows and cutoff low forms over the Arklatex region.
With lingering cloud cover coupled with low level flow veering more to the west, temps this afternoon may struggle to climb past the lower/mid 70s.
The bulk of this low pressure system is now affecting Middle Tennessee with a general northeastward movement with the storm. Current models show the highest SBCAPE values are over the southeastern quadrant of the CWA, ranging from 550-650 J/Kg with a ribbon of 400 J/Kg over the Nashville metro area. Two upper level lows will bring another round of rain across the area Saturday. The majority of the rain will come from the upper low lifting out of the Great Plains. It looks like we will get the tail end of the showers from the upper low over the Great Lakes.
Temperatures behind the front will be a good deal cooler and we may even see a few wet snowflakes from the sandhills into the panhandle. Saturday will see temps rebound well into the 60s ahead of another cold front dropping down from the north.
(Today through Saturday) A closed upper low over Middle Tennessee will track eastward through the morning hours. A trof axis extending southward from the upper low has been producing isolated showers and storms over Central Alabama since midnight. The trof axis will continue to track eastward and any remaining showers or storms should be out of Central Alabama by sunrise today. The next upstream short wave trof will move to near the TX/LA state line Saturday morning. Additional convection will develop across Mississippi Saturday afternoon in advance of the approaching upper trof.
deepening into a closed upper low. Expect convection to develop ahead of this trough across portions of AR into TX and LA starting tonight. some marginally SVR hail will be possible across SWRN/SRN sections late tonight into Sat afternoon in closer proximity to the SFC/upper lows to the south. The upper low will weaken as it moves east of the region Sat night.
(Today and tonight) The cold front is continuing to push southward and, as of 1 AM, is through the northwestern Texas Panhandle. Ongoing rain behind the front is also expected to push southward as the upper trough digs southward. Tonight will be much quieter with winds becoming light after sunset as surface ridging begins to set in. Some areas, particularly across the far southwestern Texas Panhandle, could see temps reach the freezing mark.
1217 AM CDT Fri Apr 28 2023 (This evening through Saturday) WV imagery shows upper low clearly over NE Oklahoma, about to cross into NW Arkansas. With the cold core upper low, and the storms developing in the exit region of a midlevel jet, there is a concern for the possible development of large hail in the stronger storms. Another closed low will be dropping down in place of the first, although the models favor it dropping down about 300 miles further south than the last one.
Current surface analysis reveals weak low pressure centered near west-central KY with associated cold front extending SSW through TN and MS. Otherwise to our south, an area of showers with embedded thunder has developed ahead of and along the cold front across central TN. A fairly large upper level trough will dig into the Midwest and Great Lakes region over the weekend, and gradually occlude and wrap up into a broad upper level low (ULL). A surface frontal boundary associated with the digging trough will pass through the area Saturday, and we may see some light shower along and ahead of the front with very minimal chances for storms given very weak instability.
Most places will see high temperatures in the 60s today, with parts of southeast Oklahoma and west central Arkansas reaching the lower 70s.
Temperatures will continue to trend warmer through the weekend bringing an increased risk of flooding to area streams, creeks and rivers.
Cloudy skies will persist as a low pressure to the north increases southerly flow and moisture across the area.
-Breezy and cooler Saturday. Another cold front is forecast to move into the area tonight and bring with it a round of convection. As a cold front approaches, convection from the hill country is expected to merge into an MCS/squall line and push quickly southward into our area. By sunrise Saturday convection should be offshore with cooler and drier air filtering in behind it. Low temperatures by Saturday morning will likely be into the upper 50s for a lot of the area, though may remain in the lower 60s near the coast. Upper level trough passes during the day Saturday and temperatures should remain in the 70s with cold advection going strong.
We're starting out between the exiting low over southern MN and IA at 12Z, and strong high pressure across ID and western WY. At 500mb we'll still have the main trough set up across the eastern Dakotas. The ridge will sink south tonight.
Strong upper level ridge will continue to hold over northern California through Saturday. Upper level trough moving through the Pacific NW will approach the West Coast Saturday night with lowering heights, which will likely initiate a Delta breezy, as early as Saturday evening.
(Rest of Today) The central US remains entrenched in a longwave troughing pattern. OHX's morning sounding shows the capping inversion above the freezing level with low levels of CAPE.
606 AM CDT Fri Apr 28 2023 (Today and tonight) The cold front is continuing to push southward and, as of 1 AM, is through the northwestern Texas Panhandle. Ongoing rain behind the front is also expected to push southward as the upper trough digs southward. Tonight will be much quieter with winds becoming light after sunset as surface ridging begins to set in. Some areas, particularly across the far southwestern Texas Panhandle, could see temps reach the freezing mark.
324 AM PDT Fri Apr 28 2023 There will be much warmer days for inland areas through the weekend with Saturday the hottest day for the valleys. The marine layer will keep coastal areas cooler with areas of night and morning low clouds and fog extending into western valleys with limited afternoon clearing at the beaches.
322 AM MDT Fri Apr 28 2023 Satellite shows the upper level trough axis sinking south of the forecast area, and with that heavier precipitation is quickly winding down. Deep northerly flow will be over the forecast area as a high amplitude ridge builds to our west. Over the weekend, a ridge of high pressure will be over the Rocky Mountain region, with a fairly brisk northerly flow aloft over eastern CO on Saturday.
a trough will dig down from the north and brush across the Four Corners region this morning. Moisture is extremely limited with this feature but there is the chance we could see a few light showers develop across the Kaibab, San Francisco Peaks, and over the higher points of the Chuskas. Winds will increase early this morning but should start to drop off through afternoon as the trough passes off to the east.
625 AM CDT Fri Apr 28 2023 (Today through Saturday) A closed upper low over Middle Tennessee will track eastward through the morning hours. A trof axis extending southward from the upper low has been producing isolated showers and storms over Central Alabama since midnight. The trof axis will continue to track eastward and any remaining showers or storms should be out of Central Alabama by sunrise today. The next upstream short wave trof will move to near the TX/LA state line Saturday morning. Additional convection will develop across Mississippi Saturday afternoon in advance of the approaching upper trof.
146 PM EDT Fri Apr 28 2023 Low pressure will push a cold front north through the Mid Atlantic region tonight.
(This evening through Saturday) Precipitation will taper off and move east late this afternoon into the early evening as a sharp upper level trough axis moves overhead.
100 PM CDT Fri Apr 28 2023 (This afternoon) The mid-morning water vapor imagery indicates a digging trough aloft diving S through Cntrl NM, which will eventually enter the TX Panhandle and the S Plains and remain positively tilted. Also made some minor downward adjustments to max temps today, given the slower Nwd progress of a warm front across Cntrl and ECntrl TX. This convection should weaken by mid to late evening, although scattered convection should persist evening overnight through much of the day Saturday as a closed low shifts E across the region. low MVFR cigs should develop/begin to spread E beneath the low late this evening and overnight, eventually lowering to IFR from W to E overnight through shortly after daybreak Saturday.
The lows for tonight are in the mid 40s for the entire CWA with calm, variable winds and mostly clear skies. A cold front is poised to make its way through central Illinois early Saturday morning (just before 12z Saturday) and be out of here by Saturday evening (~21z Saturday). The lows north of I-70 are expected to be in the low 40s and upper 40s south of I-70.
Expect these winds to weaken through the day as the pressure gradient loosens, and more stable high pressure moves in from the west. Highs in the 60s are expected in the high country, with 70s, 80s, and 90s in the lower elevations.
Overnight, Middle Tennessee will be stuck right along a warm front. The warm front will lift north of the area during the morning.
(This evening through Saturday) Cold front making rapid progress across the southeast portions of the area, with temperatures falling into the 50s across the Big Country. Otherwise, much cooler air mass moving into the area with temperatures diving down into the low to mid 40s tonight, or roughly 15 degrees below normal. Gusty northerly winds will continue into Saturday, but will lots more sunshine, temperatures will still have a chance to rebound back into the low to mid 70s.
The showers will exit Saturday evening as high pressure builds in from the northwest. The strong winds coupled with RH in the lower 20s by late afternoon will lead to elevated fire danger for the west river counties.
A few clouds will persist as a low pressure to the north increases southerly flow and moisture across the area. Conditions will remain pretty muggy today and tomorrow as afternoon high temperatures reach into the middle 80s to lower 90s with dewpoints in the lower to middle 70s.
(This afternoon through Saturday night) The much-advertised cold front has nearly made it to the Rio Grande early this afternoon, with gusty northerly to northeasterly winds and fairly widespread blowing dust in its wake. Saturday night will be cool, but several degrees warmer than tonight as southerly return flow resumes, with lows in the middle 40s and lower 50s across the region.
1236 PM CDT Fri Apr 28 2023 (The rest of today ) An upper level trough is diving into the area and closing off. As of right now, a band of precipitation associated with the upper level trough is moving into the CWA from the west, and is primarily being driven by mid level ascent from the diffluence of the trough. However, as the trough closes off the forcing for this ascent will wain and the precipitation band will fall apart across northeast OK. As the upper level low closes off a lower atmosphere low pressure center will spin up near the OK-TX-AR triple point, with good frontogenesis in the 925-850 hPa layer on the backside of this low.
Low pressure departs after midnight with showers diminishing in its wake. Mild conditions are expected overnight with temperatures climbing into the 60s and 70s on Saturday; although mountain locations will be slightly cooler in the 50s.
821 AM PDT Fri Apr 28 2023 Building high pressure over the Southwest will bring warmer days inland this weekend, while coastal areas are moderated by periods of low clouds and cool sea breezes in a shallow marine layer.
As the low continues northward tonight and Saturday, it will combine with an eastward moving low tracking through WI. The resulting low will strengthen and a resulting cold front will cross the region from northwest to southeast Saturday night. Low stratus and cooler air over nw CWA will keep temperatures at or below 60 for most of IN and west of a Wapakoneta-Dayton line. Eastern CWA with some sunny breaks will approach 70 degrees from Columbus to Maysville, with some lower 70s possible in the lower Scioto Valley from Waverly southward and into Lewis County KY. Suppose a few wraparound SHRA along a subtle LL convergent axis/trof cannot be completely ruled out in central OH through the first part of the overnight, but most spots will be dry tonight into Saturday morning.
159 PM MDT Fri Apr 28 2023 Upper ridging slowly moves into central MT and allows our temperatures to stay above normal through the weekend with highs flirting with the 70s each day. What will keep temperatures from increasing more is persistent east flow at the low-levels, and this will also keep surface humidities fairly mild. At the end of the weekend, the national flow becomes an omega blocking pattern, with a deep upper low off the west coast, and sitting over the Great Lakes region.
- Temperatures in the low to mid 30s tonight promote frost formation, especially across north central Kansas.
115 PM CDT Fri Apr 28 2023 Despite a recent frontal passage, we remain under a generally troffy flow pattern that will therefore subject us to its cold core of clouds/cooler temps into/thru the weekend.
So a weak cold front associated with the two systems will slowly slide east across the forecast area tonight through Saturday. Since the forecast area will be split between the two systems, the chances of precipitation remain limited due to lack of moisture return and best energy to our north and to our south as the cold front moves through.
Weak high pressure in the central Atlantic will maintain a loose grip on the Florida Keys. The system will reach the Gulf coast by late Saturday night, then pivot northeastward and merge with a trough in the northern trek of the jet stream.
(This afternoon) The mid-morning water vapor imagery indicates a digging trough aloft diving S through Cntrl NM, which will eventually enter the TX Panhandle and the S Plains and remain positively tilted. Also made some minor downward adjustments to max temps today, given the slower Nwd progress of a warm front across Cntrl and ECntrl TX.
The upper level trough axis will continue to move across the Tennessee River Valley, with a few light showers possible through the afternoon. A slightly drier and cooler airmass is working in behind the front across the northwest counties, where highs will top out in the low to mid 70s. Southeast of the front, we'll top out in the low to mid 80s with plenty of sunshine. As it does so, we'll keep an eye on the radar, as storms could become surface rooted as low-level moisture and instability increases south of the warm front. Additional showers and storms will begin to develop into the evening hours as the upper level low moves eastward out of Mississippi and becomes stacked.
(This evening through Saturday night) Zonal flow has been over the area today as we are in between a trough over the upper great lakes and another one over the southern rockies. Tomorrow, the trough over the southern rockies is expected to dig into the southern plains and eject over Texas Saturday morning. Later in the day, it is possible for more storms to develop later in the early- evening over southeast Louisiana due to dynamical forcing from the trough and its associated cold front.
A broad area of low pressure is centered over the Ohio River Valley with a couple boundaries sitting across our area. The bulk of this low pressure system is now affecting Middle Tennessee with a general northeastward movement with the storm. Current models show the highest SBCAPE values are over the southeastern quadrant of the CWA, ranging from 550-650 J/Kg with a ribbon of 400 J/Kg over the Nashville metro area. Two upper level lows will bring another round of rain across the area Saturday. The majority of the rain will come from the upper low lifting out of the Great Plains. It looks like we will get the tail end of the showers from the upper low over the Great Lakes.