Aikyam-Lab/Synoptic-Bench huggingface dataset:
South to southwesterly winds will also become gusty at CHA and TYS after 09Z with gusts of 15-25 kts as the remnants of Hurricane Laura interact with a cold front. Garuckas Chattanooga Airport, TN 84 73 88 73 87 / 50 90 70 30 30 Knoxville McGhee Tyson Airport, TN 86 73 86 70 85 / 50 100 90 30 20 Oak Ridge, TN 85 72 87 70 86 / 50 100 80 20 20 Tri Cities Airport, TN 85 70 83 65 84 / 50 90 100 30 10.
Left behind is some showers which have formed ahead of the cold front. Cold front associated with 500 mb short wave moving thru Manitoba will enter DVL basin 12z-15z and move southeast thru the area during the day. Pops in the fcst have the high pops ending in the southern fcst area by 14z then 20-30 pops ahead of the cold front. High pressure will move into E ND late tonight and east on Saturday. Warm temperatures will begin the period as the upper ridge is in place over the area. and return flow drags the warmer air into the Dakotas ahead of a cold front.
Bands of convection are expected to develop across the region with the influence of the mid-level trough, possible sea breeze interaction and lingering elevated tropical moisture levels.
1028 AM EDT Fri Aug 28 2020 Currently - A surface through lower level ridge extends westward across Florida into the Gulf of Mexico. While this mornings sounding indicated a PWAT of just over 2 inches, there are some dry layers above 800 mb and the low level contribution to CAPE is fairly weak. The background ridging, fairly weak flow and vertical structure has allowed for very little in the way of shower development this morning. Short Term Update - Ridging will continue to dominate Keys weather this afternoon. A ridge across Florida will maintain mainly gentle southeast breezes across Keys waters through the afternoon.
At 10Z (4 am MDT), the effective cold front was located invof a line from Akron-Holyoke-North Platte -- the leading edge of which is marked by an undular bore (check out KGLD reflectivity data) -- and was rapidly progressing SSE-SE into Yuma county, CO. an increasingly upslope component to low-level flow should assist in the development of widespread convection along the Palmer Divide/Raton Ridge (i.
The southwestern periphery of an upper trough remains over the region today collocated with PWATs as high as 2. The weak upper trough dampens even further on Saturday, but there is a slightly better window for a few showers over the waters toward daybreak even spreading onshore for a short distance across the northern Coastal Bend.
Overall dry weather this week but a few late day storms possible over the high Sierra today. Observed temperatures across much of interior Northern California early this morning are around 3 to 8 degrees warmer than this time yesterday. There is another weak chance of thunderstorms over the high Sierra as the upper trough moves through, though moisture looks to be less than yesterday with PWATs generally around and less than 0. Ensembles continue to indicate upper level heights lowering slight over NorCal this weekend as a weak trough moves through the PacNW.
445 AM MDT Fri Aug 28 2020 An upper level high will remain over the southern Rockies as subtropical moisture moves into the area. As far as tstm activity, believe best chc of tstm activity this aftn will focus mainly over the higher terrain and Palmer Divide, with little activity over the plains.
915 AM EDT Fri Aug 28 2020 Axis of subtropical ridge will extend across the Lake Okeechobee region today, with low level winds out of the S/SW with an increasing offshore component north of Okeechobee County/Treasure Coast. It will be another hot afternoon, with highs easily reaching the low 90s along the coast due to slower sea breeze development, and low to mid 90s over the interior. This combined with rather warm temps aloft (-5/-6C at 500mb) and a strong ridge overhead, may act to suppress convective development somewhat this afternoon. (Previous Discussion) Broad ridge axis across the central FL waters will bring favorable open water conds.
822 AM EDT Fri Aug 28 2020 Latest RAP model has deep layer ridging easing south across the area today with light easterly/variable winds becoming south and southwest for the afternoon and enhanced by the west coast sea breeze. Scattered coverage this morning becomes scattered to numerous in the afternoon with the highest inland. Winds/seas at or below 15 knots/3 feet as high pressure settling south over the state shifts winds to south and southwest then west during the weekend.
642 AM CDT Fri Aug 28 2020 A surface cold front will push through the forecast area today bringing a small chance for showers and thunderstorms. Ahead of the front, temperatures in the 90s and dewpoints in the lower to mid 70s should lead to moderate instability across the area by peak heating. A cooler and welcome pattern change is expected for the remainder of the weekend bringing cooler temperatures to the area.
Issued by National Weather Service Tulsa OK 638 AM CDT Fri Aug 28 2020 (Today and tonight) Westerly flow at 850 mb this morning will bring very warm low- level air from the High Plains east into the area today. The highest temperature at Oklahoma City so far this summer has been 97, and we are forecasting 100 this afternoon. Tonight, a cold front will approach northwest Oklahoma with some potential for showers and storms near the front late tonight.
A baggy mid level trough is across the region between a high pressure center over northern Mexico and northern EPAC through the weekend.
513 AM EDT Fri Aug 28 2020 Showers and thunderstorms are on tap again today, and cloud cover may keep it much cooler than the past few days.
Weak west/northwest flow aloft will prevail around a broad upper level ridge over south TX, into the gulf.
Cold front lats across extreme northwest Colorado down into the Texas/Oklahoma Panhandle this afternoon. GFS 700mb winds climb to 25-30kts out there after 15Z with afternoon humidity falling back into the low teens.
257 PM CDT Fri Aug 28 2020 High pressure across the region is finally giving way to a cold front crossing the local area this afternoon. as a strong CAP in place across the area will likely prevent any further development along the cold front through the afternoon hours. The main story for tomorrow will then be the much cooler temperatures. Expect noticably cooler temperatures and multiple. expect an area of decaying convection from the high plains to approach the local area during the overnight hours.
435 PM EDT Fri Aug 28 2020 A stationary front associated with a developing low pressure over northwest Ohio is expected to transition into a warm front and begin moving northward overnight. The low pressure will force a cold front southeast across the area Saturday morning.
The prefrontal trough has allowed winds to shift to the northwest across the area, but the true front bringing lower dew points is still moving across western MN. Brief upper ridging on Saturday, with light winds and highs in the 70s. The pattern begins to shift Saturday night as the next upper trough moves into the northern Rockies and winds pick up from the southeast as low pressure develops over western ND. Overnight lows should still be fairly cool in the upper 40s and 50s as the higher dew points do not arrive until later in the weekend.
1130 AM EDT Fri Aug 28 2020 Showers and thunderstorms are on tap again today, and cloud cover may keep it much cooler than the past few days.
Deterministic runs predict the weak upper trough axis over the CNTRL/WRN Gulf of Mexico to move slowly westward or remain quasi- stationary during the period.
The remnants of Laura are located over the Mid-Mississippi Valley region early this afternoon and are embedded in an upper level trough that extends southward across the Lower Mississippi Valley and into southwest LA/southeast TX. A deeply moist south to southwest flow persists across the north central Gulf Coast region this afternoon ahead of the trough axis. The upper level trough axis will progress eastward across the Tennessee Valley tonight before moving over the Eastern Seaboard and western Atlantic by late Saturday afternoon. A weak upper level trough axis remains oriented from western AL through southeast MS and LA on Saturday. Highs Saturday range in the upper 80s along the coast to the lower 90s inland, but the high humidity allows for maximum heat indices in the upper 90s to around 103 degrees.
141 PM CDT Fri Aug 28 2020 Upper ridge centered over NM today will expand east across TX as the remains of Laura move off to the east.
Tonight and Saturday The earlier convection north of the warm front and with the MCS has really stabilized the atmosphere early this afternoon. It is trying to destabilize again but it is difficult to determine whether it can quickly enough to get severe storms across east central Wisconsin before the cold front moves through. Saturday will be mostly sunny and cooler, though a bit breezy.
24 hour temps are already 3 to 10 degrees warmer than yesterday. 6 (Today and tonight) Westerly flow at 850 mb this morning will bring very warm low- level air from the High Plains east into the area today. The highest temperature at Oklahoma City so far this summer has been 97, and we are forecasting 100 this afternoon. Tonight, a cold front will approach northwest Oklahoma with some potential for showers and storms near the front late tonight.
A cold front is forecast to move through the area Saturday morning with a wind shift to NNW. Early Saturday morning thunderstorms and a cold front could impact KPVW. Simultaneously a cold front will be moving southward towards the FA. High pressure extends from the Caribbean Sea into northern Mexico and into the desert southwest.
Radar trends have shown greater concentration of showers and storms over northwestern half of the CWA in wake trough axis behind Laura, with cell motions to the NE 15-20 kt, bases generally running 025-035.
132 PM PDT Fri Aug 28 2020 Cooler conditions can be expected this weekend as the high pressure system that was dominate over the west gets pushed to our south and a weak trough of low pressure moves across the California coast.
A cold front was located across far western KS this afternoon, and thunderstorms are to develop this afternoon/evening over the high plains in upslope regime north of the boundary. Sustained cells near the boundary may also possess a limited tornado threat, especially as the low level jet strengthens 00-03z.
While the remnants of Laura continue to spin over the Mid- Mississippi Valley, mid-level ridging centered just to our west is bringing mostly clear skies and hot temperatures to south-central TX. As of 18Z many locations are already in the upper 90s to near 100, and with dew points in the low to mid 70s heat indices already range from 100-110 except across the Hill Country. The ridge will gradually de-amplify through the period, but similarly hot conditions are expected tomorrow.
231 PM MDT Fri Aug 28 2020 Lingering low-level moisture behind a cold front continues to manifest itself as a stratus deck over portions of cntrl/s cntrl SD this aftn, with a very shallow cu field evident to its NW via satellite imagery. Sfc analysis indicates that a center of high pressure continues to nose SEwd into the Dakotas. High pressure shifts toward cntrl SD/NE overnight, initiating return flow over the WY plains and into wrn SD.
As the high pressure system continues to slide southeastwards, quiet conditions are expected throughout the day on Saturday. Look for afternoon highs to be a touch cooler than they were today, hovering closer to the 80 degree mark with dew points continuing to drop into the lower 50s.
1227 PM EDT Fri Aug 28 2020 Showers and thunderstorms are on tap again today, and cloud cover may keep it much cooler than the past few days.
On Saturday, a trough will push southeast across southwest Canada with an increasing westerly flow over the forecast area.
Later in the evening and early overnight, model soundings show some upper to mid level drying as we get on the backside of the low, and that will bring the rain threat to an end from west to east during the overnight hours. Getting into the day Saturday, the upper low will be well off to the east, but rain chances will return in the afternoon. A cold front looks to move in from the north during the late afternoon and evening, which will help kick off some showers and thunderstorms.
1224 PM EDT Fri Aug 28 2020 Upper level and surface ridging will remain in control of the region today with remnants of Hurricane Laura moving through the region Saturday.
However, with a tropical system, PWAT values in addition to a high freezing level/deep warm cloud depth support showers and storms producing very heavy rainfall in a short duration.
/issued 822 AM EDT Fri Aug 28 2020/ Latest RAP model has deep layer ridging easing south across the area today with light easterly/variable winds becoming south and southwest for the afternoon and enhanced by the west coast sea breeze. Scattered coverage this morning becomes scattered to numerous in the afternoon with the highest inland. Winds/seas at or below 15 knots/3 feet as high pressure settling south over the state shifts winds to south and southwest then west during the weekend.
1237 PM CDT Fri Aug 28 2020 (Today and tonight) Westerly flow at 850 mb this morning will bring very warm low- level air from the High Plains east into the area today. The highest temperature at Oklahoma City so far this summer has been 97, and we are forecasting 100 this afternoon. Tonight, a cold front will approach northwest Oklahoma with some potential for showers and storms near the front late tonight.
Things begin to change tomorrow when a mostly dry cold front moves through the region. The higher terrain could see gusts exceeding 40 to 45 mph at times as well.
Thunderstorm chances will return Saturday night with a weak short wave trough and waa moving into the region.
146 PM EDT Fri Aug 28 2020 Aviation -Showers and thunderstorms through this morning -Another more potent round of storms through Friday night -Cooler trends through weekend No major changes to the going forecast. It wouldn't be surprising at all to for this convection to be the primary activity today and essentially work over the atmoshpere prior to the arrival of the cold front. These showers and storms are sparking off a warm frontal boundary that is draped east to west across the region. Following the boundary and the corresponding warm front will be a cold frontal boundary that will move through the region Friday night into Saturday. --Cooler trends through weekend-- Temperatures will cool down behind the front Saturday. Scattered to numerous thunderstorms are expected ahead of a cold front that is currently in western Wisconsin.
947 AM PDT Fri Aug 28 2020 Cooler conditions can be expected this weekend as the high pressure system that was dominate over the west gets pushed to our south and a weak trough of low pressure moves into California.
With winds out of the southeast off of the Gulf of Mexico bringing in plenty of moisture and an upper level ridge across Northern Mexico and the Texas Big Bend Region highs will soar to some of the highest levels seen this summer.
253 PM CDT Fri Aug 28 2020 Hot and a bit humid this afternoon as the region is sandwiched between Tropical Depression Laura to the southeast and an approaching cold front to the northwest. This cold front should enter NW Missouri by this evening and be completely through the region by Saturday morning. Cooler air will come into the region behind the front, and this paired with ample high level cloud cover will yield high temperatures on Saturday likely around 10 degrees or so cooler than those of today.
The western CWA has seen sunny skies most of the day and has warmed into the low to mid 90s with heat index values in the mid to upper 90s. A cold front will move south into the area late tonight and Saturday. Highs Saturday will range from the low-mid 80s over the north to the mid 90s near the Arkansas Border, where heat index values will be as high as 100.
The primary story going into the weekend will be the strong ridge centered initially over the region and the hot temperatures. The H5 ridge center across south Florida will generate general subsidence, which will limit cloud cover and precipitation chances through Saturday afternoon. Tonight the ridge begins to weaken a bit and slides southward. With thicknesses a bit lower and heights slowly dropping, temperatures may be a degree or two cooler on Saturday, but many will not notice the difference again as heat index values across the southern metros climb well into the 100s.
1227 PM CDT Fri Aug 28 2020 At 08Z, an outflow boundary was dropping south through the central Sandhills as the main cold front was dropping southeast through the northwest Sandhills. Temperatures remained in the low to mid 70s ahead of the front, with lower 60s reported across the northern panhandle. Today, an upper trough will move into the western Great Lakes. Will keep a slight chance for showers across the far northeast until mid-morning, which will be just ahead of an advancing cold front and 700mb trough passage. the cold front will clear eastern counties by late morning. Highs will be noticeably cooler in the lower to mid 80s, with upper 80s across the southwest. Much cooler lows from the upper 40s to lower 50s north to mid 50s south.
At upper levels, flow will be nearly zonal and a ridge will build to the north in Montana and southern Canada. At the surface, high pressure moves in from the north, crossing through Nebraska overnight, causing winds to shift from the north to the south by Saturday morning.
251 PM CDT Fri Aug 28 2020 (Issued 250 PM CDT Fri Aug 28 2020) Tonight through Saturday night: The cold front currently over southeast Minnesota and northeast Iowa will be main driver of any additional thunderstorms today. At this point coverage looks isolated to scattered with the best chances over far southern and far southeastern Wisconsin as that area hasn't been worked over as much and it's where the highest instability and lapse rates are expected.
Ridge aloft and mid level drier air has limited storm development so far this afternoon.
Cold front will gradually shift south of the state during the early evening.
A cold front and frontal wave will move across much of western and parts of northern Oklahoma on Saturday. The front will bring some relief to parts of western and northern Oklahoma with: post frontal clouds, cooler air, and perhaps widely scattered showers and thunderstorms.
335 PM CDT Fri Aug 28 2020 Lower Mississippi River Valley region is under the influence of wake trough aligning with upper level trough axis to maintain a focus for convection that has persisted since the early morning from southwest Louisiana, through the Atchafalaya Basin into southern Mississippi. GFS shows some enhancement of moisture on an axis oriented on the west flank of the building Bermuda ridge that lurks off the coast heading into Saturday.
CD Chattanooga Airport, TN 73 88 73 87 71 / 80 50 30 30 40 Knoxville McGhee Tyson Airport, TN 73 86 70 85 69 / 90 50 30 20 40 Oak Ridge, TN 72 87 70 86 69 / 90 40 20 20 50 Tri Cities Airport, TN 70 83 65 84 63 / 90 80 30 10 50.
305 PM CDT Fri Aug 28 2020 A cold front stretches from northeast Iowa southwestward to near KDSM to KOMA. Ahead of the cold front dewpoints were in the upper 60s to lower 70s with temperatures in the upper 80s to near 90 degrees. An unstable but capped environment is in place across the region ahead of a cold front that will move across the area this evening. Model timing appears to be slower than originally thought based on observations although a secondary cold front is moving through northwest Iowa. Behind the cold front, expect clearing skies overnight with falling temperatues and dewpoints. High pressure will move across the region through the weekend with lower dewpoints and noticeably cooler temperatures on Saturday.
324 PM EDT Fri Aug 28 2020 Synopsis/Discussion/Marine/Hydro - Storms tonight, then a dry weekend - Cooler -- Storms tonight, then a dry weekend -- Low pressure over northwest Wisconsin this afternoon will drag a cold front eastward across Lower Michigan tonight. Cooler air will flow in behind the front. An even cooler airmass will arrive by the end of the week. Scattered to numerous thunderstorms are expected ahead of a cold front that is currently in western Wisconsin. Cold air flowing in behind the cold front tonight will will cause waves to build Saturday. A cold front just moving through Western Wisconsin will track across southwest Lower Michigan this evening triggering another round of storms.
The cold front remains on track to impact the area Saturday evening, bringing gusty conditions across the region.
136 PM CDT Fri Aug 28 2020 At 1 pm, a surface cold front was dropping south through the area, extending from northeast WI through southwest WI and then into northeast IA. Otherwise, there is currently a N-S line of showers forming across north central MN associated with mid-level trough but these are expected to weaken/diminish as they approach our area this evening. For the rest of tonight, drier and cooler air continues to filter in courtesy of Canadian high pressure building in. Quiet/cooler/drier weather set for the weekend as Canadian high pressure builds over the region.
358 PM CDT Fri Aug 28 2020 A cold front approaching the CWA is expected to lead to showers and thunderstorms this afternoon and evening. Lows are expected to be a bit cooler than last night, with temps in the low to mid 50s. This cold front is in conjunction with a vertically stacked low currently over northwestern Ontario. The low is expected to slide southeastward, reaching the eastern side of Lake Superior tomorrow afternoon. This low pressure is expected to interact with high pressure likely to build over North Dakota tonight into tomorrow. High pressure remains over the area heading into Saturday night leading to mostly clear skies and winds calming down by early evening.
759 PM PDT Fri Aug 28 2020 Cooler conditions can be expected this weekend as the high pressure system that was dominate over the west slips south, and a weak trough develops along the California coast.
750 PM EDT Fri Aug 28 2020 Aviation - Storms tonight, then a dry weekend - Cooler -- Storms tonight, then a dry weekend -- Low pressure over northwest Wisconsin this afternoon will drag a cold front eastward across Lower Michigan tonight. Cooler air will flow in behind the front. An even cooler airmass will arrive by the end of the week. Later tonight and early Saturday (after the storms have ended) expect MVFR cigs to pour in from the north behind a cold front, with winds shifting to the northwest and increasing to 10-20 kts. Cold air flowing in behind the cold front tonight will will cause waves to build Saturday. A cold front just moving through Western Wisconsin will track across southwest Lower Michigan this evening triggering another round of storms.
Forecast is on track calling for increasing west winds Saturday afternoon as a dry cold front approaches from the northwest.
Overall dry weather this week but a few late day storms possible over the high Sierra today. Today's model guidance has backed off on the high elevation thunderstorm threat substantially; however, there is still a slight chance we could see an isolated storm or two due to orographic lift. Current temperature readings across interior norCal range from upper 70s in the higher elevations to the mid 90s to 106 down in the Valley. The Delta Breeze is expected to make another appearance tonight, Ensembles continue to indicate upper level heights lowering slight over NorCal this weekend as a weak trough moves through the PacNW.
/issued 141 PM CDT Fri Aug 28 2020/ Upper ridge centered over NM today will expand east across TX as the remains of Laura move off to the east.
CKV is in closest proximity to the low pressure center of remnant Laura, so heavier RA has tapered to -RA or VCSH.