Aikyam-Lab/Synoptic-Bench huggingface dataset:
The main cold front is well southeast of the area, extending from central Kansas through central Iowa. Otherwise, skies were overcast with temperatures mostly in the lower 50s across western Nebraska. The southern extent of the upper trough axis will swing across western Nebraska tonight, providing one last shot for showers. The highest chances will be in the evening from near 60 percent east of Arnold through Valentine, and 30 to 50 percent to the west. Clearing skies after midnight in the eastern panhandle and western sandhills for lows in the lower to mid 30s. On Tuesday, mostly sunny skies return as the upper trough lifts from the Dakotas into the western Great Lakes.
730 PM EDT Mon Sep 25 2017 An upper level ridge will remain over the region through mid week. Much cooler air will settle into the region by the end of the week. The ridge will continue to hold across the region on Tuesday. Since the area is on the backside of the ridge, the low level moisture will be on the increase, so there should be an increase in cu for Tuesday. Cold front will be pushing up the Ohio Valley Tuesday night, but the night should be dry. Lows will be in the lower to mid 60s.
537 PM MDT Mon Sep 25 2017 Water vapor shows upper low over central WY, with a deep moisture plume through the Plains, including our south central SD zones. Upper low is then expected to shift into western ND overnight, with showers coming to an end and clouds eroding in our western/southwestern zones. Dry and warmer weather then expected the remainder of the work week with weak ridging aloft. An upper low over the Desert Southwest is then expected to lift northeast and get picked up by the next upper trof spreading into the Pacific Northwest.
MVFR CIGs will once again move in tonight and will remain through the end of the TAF period as a cold front arrives around 18Z Tuesday shifting winds from the northeast and bringing more moisture and rainfall. /issued 325 PM CDT Mon Sep 25 2017/ WV imagery shows the upper trough has moved NE over the past 24 hours, and is now centered over SE MT. This is still scheduled to move into Canada by 00Z Wed, at which time a secondary trough will be taking its place over srn NV. Of more immediate concern is a cold front that has just entered the NW Texas Panhandle. Ensembles indicate anomalous PWATs of 2 std devs or better running just left of central Texas, up thru the Panhandle, coincident w/a low-lvl theta-e ridge, all of which should help maximize rainfall potential efficiency.
Think things should saturate enough by 03Z for some rain to start and generally went with a HRRR and continuity blend, maybe increasing the higher POPs by about an hour or two. Upper low to propagate east from the northern high plains across the forecast area overnight and Tuesday. Model guidance indicating best potential across the remainder of the forecast area from 12-18z Tuesday with upper low passage. Will keep higher pops across the east closer to surface inverted trough. Rain should gradually diminish Tuesday night as upper low continues to propagate northeast.
Warmer and drier conditions will exist across the area through midweek. The next upper low will develop over western Arizona Tuesday, then turn back to the north and impact much of southern and eastern Utah during the latter half of the week. The forecast area remains within a mean longwave trough position this evening. This upstream feature will continue south overnight, eventually forming a closed low over the lower Colorado River valley during the day Tuesday, leaving a mid level deformation axis across the forecast area with a dry airmass. As this low eventually lifts northward during the middle to latter portion of the week, moisture will spread northward into the forecast area, bringing a chance of showers to the eastern half of the CWA.
705 PM CDT Mon Sep 25 2017 Little change the next 12 hours as a cold front slowly makes it way across the area. JPK Upper pattern will be transitioning from southwest to northwest flow mid-late this week as upper trough currently over western Canada digs southeastward into the eastern CONUS.
The cold front is currently located from a Chanute, KS to Oklahoma City line and will continue to slowly push southward overnight TUL 69 81 63 72 / 20 50 60 50 FSM 68 89 69 85 / 10 10 20 30 MLC 69 86 66 79 / 10 20 20 30 BVO 66 77 60 70 / 30 70 60 50 FYV 63 84 63 77 / 10 20 20 30 BYV 64 85 64 76 / 10 20 20 30 MKO 68 85 65 76 / 10 30 20 30 MIO 67 82 62 71 / 10 50 50 50 F10 68 83 64 74 / 10 30 30 40 HHW 68 89 69 85 / 10 10 10 30.
These conditions will be short lived as we are seeing low clouds build in behind the southward moving cold front. Storms south of the front in the warmer area have been holding together. The upper level trough over the western CONUS that has provided this prefrontal southerly flow is now working its way west over the Central Plains and towards the Great Lakes.
849 PM CDT Mon Sep 25 2017 An increasingly sheared cut-off low is still evident in GOES-16 Water Vapor bands and in model analyses to our S-SW. Weak ridging is building over the area today and the subsidence associated with it will result in a dry forecast for the short-term.
Weak ridging at the surface and aloft remains in place across the northern gulf coast. also, an upper trough is located across the western half of the country.
The first of which will be in the form of precipitation chances ahead of a cold front, expected to cross through northwest Missouri this evening, steadily pushing through the remainder of the CWA through Tuesday morning. Showers and thunderstorms are expected to continue ahead of and along the cold front as the boundary pushes through central Missouri during the evening and overnight hours.
Slow moving cold front across central OK will track slowly east. MVFR/IFR cigs possible in these locations as well with MVFR cigs persisting into Tuesday morning/afternoon as cold front passes through. /Issued 353 PM CDT Mon Sep 25 2017/ A cold front will progress slowly east across the area late tonight and Tuesday.
20Z, a weak cold front was draped along a line from Ladysmith to Rochester to Mason City. For this evening, a second area of showers and scattered thunderstorms currently across southwest IA are expected to lift northeastward along the eastward advancing cold front and across the forecast area. Overcast skies will keep temperatures elevated despite the cooler air mass, with lows from the upper 50s to lower 60s. Aforementioned cold front will be across the far eastern forecast area by 12Z Tuesday and then into eastern WI by mid-afternoon. Temperatures Tuesday will be noticeably cooler, ranging from the mid 60s across the northwest to mid 70s across the southeast.
An increasingly sheared cut-off low is still evident in GOES-16 Water Vapor bands and in model analyses to our S-SW. Weak ridging is building over the area today and the subsidence associated with it will result in a dry forecast for the short-term.
Ridging at the surface and aloft will continue to provide us with dry, warm weather through Tuesday.
Think the heaviest rainfall amounts will be along or just west of the KS turnpike, where instability will be the highest. As the front pushes south, cooler more seasonal type temps with highs in the 70s and lows in the 50s look to return to the region. Ketcham Ridging looks to shift over the region for Wed night through Fri, with drier air moving into the northern plains. Upper ridging looks to flatten out for the weekend, with chances of showers and a few storms increasing for Sat/Sun. Ketcham Widespread MVFR and areas of IFR will prevail behind a slow moving cold front across central Kansas tonight with these conditions gradually developing further east across south central and parts of southeast Kansas on Tuesday morning.
Will continue to see quiet conditions with high pressure in control.
Isolated to scattered showers have been confined to the southwest portions of central Alabama this afternoon, in response to an upper low over Mississippi.
744 PM EDT Mon Sep 25 2017 High pressure over the Eastern Great Lakes today will weaken and shift east Tuesday.
Upper low over the Great Basin will lift northeast tonight, and should in the process spread showers northeast across much of the cwa along and east of the Missouri River valley. It should start to slowly clear off on Tuesday from southwest to northeast across the cwa, as the upper low tracks away from the region. KMBG and KPIR will improve to VFR after midnight, but KABR and KATY will remain under the lower cigs until Tuesday afternoon.
631 PM CDT Mon Sep 25 2017 Deep trough through the Rockies will finally eject the main impulse northeastward across the area later this evening, leaving behind a closed portion around western AZ. Northwest winds should freshen a bit more, and eventually the subsidence with cold advection and passage of the upper trough should work on breaking clouds, but still a seasonably cool day in the upper 50s to mid 60s.
727 PM EDT Mon Sep 25 2017 High pressure will hold over the region tonight and will shift east on Tuesday.
833 PM EDT Mon Sep 25 2017 Maria continues to lift north well to the east of the state weakening the ridging that was in place across the area. Temperatures are on track to fall into the lower to mid 70s.
Winds are northerly above 500 mb from being under the western side of an upper low. /issued 409 PM CDT Mon Sep 25 2017/ Weak upper low is over the forecast area and is triggering a few showers and thunderstorms over the area.
Chattanooga Airport, TN 65 89 66 90 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 62 88 64 87 / 0 0 0 0 Oak Ridge, TN 63 88 65 88 / 0 0 0 0 Tri Cities Airport, TN 59 87 60 86 / 0 0 0 0.
A cold front will pass through the region Tuesday night which may touch off a few showers or a thunderstorm. The main story with the front however is that cooler air will filter in behind it.
Clear skies and calm winds should let the lows drop into the upper 20s to low 30s. We should remain a degree or two warmer on the lows tonight but still below freezing in many spots.
A Wet Start to the Week, but Cooler/Drier the Next Several Days. Forecast concerns in the short term will primarily be the ending of the showers and thunderstorms, then cooler temperatures for the rest of the week. The latest subjective surface analysis highlighted a cold front over southeast Nebraska and southwest Iowa at Noon. Water vapor satellite imagery/the H50 pattern depict a closed low pressure system over southeast Montana with troughing extending southwestward toward southern California. The short range models are in good agreement with the closed low opening up tonight as it shifts east into the Dakotas.
A cold front along the the I-35 corridor is expected to edge slowly towards our area tonight and on Tuesday keeping most of our area unseasonably warm for another 24 to 36 hours. If the frontal boundary slows down any tomorrow, a few more record highs will be broken tomorrow afternoon, especially across the east and southeast areas just ahead of the cold front. Warmest temps, as mentioned above, should be over east central and southeast Illinois ahead of the slow moving front with afternoon highs ranging from the mid 80s northwest to the lower 90s roughly along and especially east of the I-55 corridor.
A weak upper level low pressure area centered over southeast Mississippi will drift south-southeast and begin to dissipate as a weak upper level ridge begins to build west of the low. Isolated showers to scattered and thunderstorms are expected to re-develop after mid Tuesday morning southwest of a line from Butler AL to Navarre Beach FL (closer to the upper low) due to decreasing stability.
Clouds continue to move southeast into the area, with very light returns showing up on radar over the higher terrain of Baker County, northern Harney and Malheur Counties, and the West-Central Mountains.
1002 PM MDT Mon Sep 25 2017 Upper low is slowly lifting ne across the area. Could see a few of the high spots obscured in low clouds/fog too. One other concern is freezing temperatures east of the divide. Will issue a sps for low lying freezing temps. Debated a freeze watch or warning but we've had several episodes already around freezing so will wait for the killing freeze yet.
Radar imagery shows echoes around small closed low affecting the eastern zones this evening. Templer Previous discussion - Synoptic Setup: a large trough runs from the western Dakotas through Manitoba. A broad weak ridge resides over British Columbia and the high Plains of Alberta. The ridge to the west is attempting to push dry air near the surface inward but the clash of these two airmasses has generated a stall and therefore only the western zones may be clear with lows bottoming out overnight. Tuesday: Ridge will begin to win out and should clear out most of the eastern zones as well.
Next main s/wv trough for organized precipitation actually approaches just after this forecast cycle, and mainly affecting far southwest Oklahoma and KSPS terminals. /issued 351 PM CDT Mon Sep 25 2017/ Just east of the thicker cloud shield over western Oklahoma and north Texas, weak instability has developed where temperatures have warmed into the lower/mid 80s. As a cold front moves across Oklahoma and western north Texas tonight into Tuesday, the axis of better rain chances will gradually shift to the south and east.
746 PM EDT Mon Sep 25 2017 Hurricane Maria will continue to move to the Northeast of the region Tonight, with high pressure to the Northwest. Coastal flood advisory to continue, and have extended the high risk for rip currents for NE FL through Tuesday.
708 PM EDT Mon Sep 25 2017 High pressure remains in control through midweek. Cold front to bring cooler temperatures but limited precipitation Thurday. High pressure dominates the weather the start the week. Temperatures will remain well above normal for this time of year to start the period as the responsible upper-level ridge erodes with an approaching trough from the West.
Upper level low over Wyoming this morning will advect into southern Ontario while the base of the trough spins over the four corners. The associated cold front tied to the Ontario low will bring the band of showers and thunderstorms eastward into western Missouri tonight into Tuesday.
A slow moving cold front will move though much of eastern Oklahoma late tonight into tomorrow bringing scattered showers as well. The cold front is currently located from a Chanute, KS to Oklahoma City line and will continue to slowly push southward overnight TUL 69 81 63 72 / 20 50 60 50 FSM 68 89 69 85 / 10 10 20 30 MLC 69 86 66 79 / 10 20 20 30 BVO 66 77 60 70 / 30 70 60 50 FYV 63 84 63 77 / 10 20 20 30 BYV 64 85 64 76 / 10 20 20 30 MKO 68 85 65 76 / 10 30 20 30 MIO 67 82 62 71 / 10 50 50 50 F10 68 83 64 74 / 10 30 30 40 HHW 68 89 69 85 / 10 10 10 30.
745 PM EDT Mon Sep 25 2017 High pressure over the Eastern Great Lakes today will weaken and shift east Tuesday.
Think the heaviest rainfall amounts will be along or just west of the KS turnpike, where instability will be the highest. As the front pushes south, cooler more seasonal type temps with highs in the 70s and lows in the 50s look to return to the region. Ketcham Ridging looks to shift over the region for Wed night through Fri, with drier air moving into the northern plains. Upper ridging looks to flatten out for the weekend, with chances of showers and a few storms increasing for Sat/Sun. Ketcham Widespread MVFR and areas of IFR will prevail behind a slow moving cold front across central Kansas tonight with these conditions gradually developing further east across south central Kansas.
1026 PM CDT Mon Sep 25 2017 Deep trough through the Rockies will finally eject the main impulse northeastward across the area later this evening, leaving behind a closed portion around western AZ. Northwest winds should freshen a bit more, and eventually the subsidence with cold advection and passage of the upper trough should work on breaking clouds, but still a seasonably cool day in the upper 50s to mid 60s.
827 PM EDT Mon Sep 25 2017 High pressure will bring dry and warm weather through mid-week before the passage of a cold front heralds a return to seasonably-cool conditions. Upper ridging on the nrn side of Hurricane Maria will maintain broad subsidence over the region, leading to dry mid levels and only passing cirrus. After another warm day on Wed, this front will make a swd push Wed evening and help escort the hurricane out to sea, but will also serve to scour out the low-level warmth and moisture from the area. Given a more-realistic dewpoint in the low-mid 60s, instability is more meager, so PoPs with the frontal passage were reduced from the default model blend values. High pressure returns on Thu with a marked cooldown expected.
1056 PM MDT Mon Sep 25 2017 Water vapor shows upper low over central WY, with a deep moisture plume through the Plains, including our south central SD zones. Upper low is then expected to shift into western ND overnight, with showers coming to an end and clouds eroding in our western/southwestern zones. Dry and warmer weather then expected the remainder of the work week with weak ridging aloft. An upper low over the Desert Southwest is then expected to lift northeast and get picked up by the next upper trof spreading into the Pacific Northwest.
1149 PM CDT Mon Sep 25 2017 Little change the next 12 hours as a cold front slowly makes it way across the area. JPK Upper pattern will be transitioning from southwest to northwest flow mid-late this week as upper trough currently over western Canada digs southeastward into the eastern CONUS.
I also adjusted temperatures down a degree or two in eastern zones due to observed afternoon temperatures trending cooler than forecast. Upper level low will continue to work across SE Montana and into the Dakotas tonight. Will see warmer and dry conditions on Tuesday, with downslope west/northwest winds spreading across the area.
Observational data this evening show an area of high pressure over the Ohio River Valley has weakened as Hurricane Maria continues to move slowly northward off the coast of North Carolina.
Continuous synoptic ascent is expected through Tuesday morning across this area aided by a longwave trough axis anchored across the intermountain west and northwest Mexico.
1012 PM EDT Mon Sep 25 2017 Currently - The Florida Keys lie in a region of nebulous flow due to lower pressure out to the southwest, Hurricane Maria off the Carolina Coast, and high pressure over the eastern United States. The environment has moistened considerably over the past day, largely due to a nearly cut off upper level low over the extreme eastern Gulf of Mexico.
/issued 351 PM CDT Mon Sep 25 2017/ Just east of the thicker cloud shield over western Oklahoma and north Texas, weak instability has developed where temperatures have warmed into the lower/mid 80s. As a cold front moves across Oklahoma and western north Texas tonight into Tuesday, the axis of better rain chances will gradually shift to the south and east.
1002 PM EDT Mon Sep 25 2017 High pressure remains in control through midweek. Cold front to bring cooler temperatures but limited precipitation Thurday. High pressure dominates the weather the start the week. Temperatures will remain well above normal for this time of year to start the period as the responsible upper-level ridge erodes with an approaching trough from the West.
High pressure will hold on for a little bit longer across northern Michigan bringing more unseasonably warm conditions through Tuesday. An approaching cold front will result in low end shower or thunderstorm chances later Tuesday afternoon across far western sections of the forecast area (though there isn't a lot of cape to work with per model soundings). Highs Tuesday ranging from the lower 80s north to the upper 80s south. Flattening upper ridge quickly erodes as it gets shunted east Tuesday evening. This front will usher in a sharply colder airmass with temperatures running a good 20+ degrees cooler than the current warm stretch (but near normal for late September).
Main upper trough aloft is forecast to move into the Dakotas after midnight with westerly flow aloft over our counties. Will carry low POPS for showers this evening with some instability and cooler temperatures aloft. May see some increasing clouds in advance of the approaching upper trough near the Four Corners.
Stratus deck continues to edge in from the south early this morning with the main trough evident on water vapor imagery over the intermountain west. Low to mid 50s will be common with perhaps slightly warmer high temperatures across our far southeastern counties. The lower levels of the atmosphere remain fairly saturated even as this happens and thus could see some areas of drizzle. Will remain on the cool/normal side for temperatures Sunday, as the cooler air lingers behind the retreating trough.
A few light showers or drizzle is possible over the eastern half this evening along and ahead of a cold front. Clouds will then be on the increase Sat ahead of a low pressure system. weak ridging and drier air building quickly into the area behind the system will bring an end for most of the pcpn. Sunday night, lowering inversion heights and dry low level air should limit potential for additional lake pcpn as weak ridging builds into the area.
341 AM CDT Sat Oct 14 2017 Looking at one more summer-like day before a strong cold front arrives tonight with a chance for showers and thunderstorms. A large upper ridge was centered over the central Gulf Coast this morning with our region on its western periphery. Temperatures will be hot for mid October as a mid level thermal ridge sets up over the area.
This evening's surface analysis showed a rather strong high pressure ridge along the U. Deep layer high pressure will continue to drive the region's weather through the short term period. Drier air underneath the passing ridge axis to the north will continue to filter into the region, driven by northeasterly mid-level flow along the eastern periphery of the high.
A limited severe threat will be possible north of Interstate 44 early this evening where surface based instability will be the highest.
A weak and broad trough is moving west near the Yucatan Peninsula. Island communities are in the lower 80s, and aside from portions of the Lower Keys, most locations have been rain free. A weakened TUTT cell currently northeast of the Bahamas will consolidate over the next couple of days, strengthened by infusions of mid level energy rounding the mean layer ridge.
424 AM EDT Sat Oct 14 2017 Ridge of high pressure across the area will remain in place through the weekend providing mostly clear skies and light winds.
The day will begin with quite a bit of cloud cover across the southern half of the area as high pressure east of the Appalachians has spread low level moisture into the TN Valley. Morning clouds may keep temps a bit below yesterday's highs, in the lower 80s for most spots.
A passing cold front will lead to breezy north winds across the region this afternoon, with the windiest conditions in the Colorado River Valley.
305 AM CDT Sat Oct 14 2017 High pressure both aloft and at the sfc has resulted in calm or light srly sfc winds, thus maintaining moist lower levels with dewpoints in the 60s and 70s being commonplace early this morning. This slight downslope wind component coupled with the presence of the UL ridge will promote dry conditions and above normal warmth, with daytime temps warming into the lower 90s today. However, changes will be underway tonight as an UA trough across the northern Rockies early this morning, translates eastward onto the Plains and towards the Great Lakes Region by tomorrow morning. A cold front associated with the said disturbance will be propagating southeastward nearing far southeast OK and extreme northeast TX between 15/06Z-15/09Z, impinging the aforementioned areas as well as southwest AR aoa 15/12Z according to the majority of the model solutions.
Broad high pressure over the Southeast Plains will slowly weaken today into Sunday as it moves over South Florida.