Aikyam-Lab/Synoptic-Bench huggingface dataset:
The Pacific Northwest will remain under a northwest upper level flow due to upper level ridging along 130W. The highest pops will be over the Blue and Wallowa mountains and along the Cascade crest. Low to moderate chances of precip should continue into Wednesday night as a warm front develops ahead of a Pacific system expected to affect the region beyond this time period. Some rain or freezing rain may begin to mix in over central and east-central Oregon Wednesday morning as snow levels begin to rise. As such, could see some rain or freezing rain begin to mix in with the light snow over north-central Oregon and Oregon Blue mountain foothills during these periods.
Surface analysis reveals a high pressure off the VA/NC coastline, with a slow moving frontal boundary sagging across northern portions of AL/GA/SC. ) With dew points holding high and precipitation ongoing across the CWA - the low temperature forecast near 70 seems solid.
/issued 308 PM CST Tue Dec 26 2017/ SHORT TERM (Tonight through Wednesday Night): Colder weather is on the way, with a cold front expected across the ranchlands and brush country between 9 pm and 3 am tonight, and arriving in the lower valley between 3 am and 9 am Wednesday morning. Low temperatures tonight will range from the upper 40s across the ranchlands and brush country to the lower 60s for the lower valley.
601 PM EST Tue Dec 26 2017 An arctic cold front will gradually sag south through the region tonight through Wednesday and will stall south of the region Wednesday night.
The clouds may help temps to stay warmer than elsewhere.
/Tonight through Wednesday/ Center of arctic high pressure was centered over southeast South Dakota this afternoon. The models were consistent in moving the center of the high southeast having it centered over southwest Iowa by 12z Wednesday. Apparent temperatures are forecast to range from 17 to 28 below zero with light northwest winds ahead of the high pressure center easily within wind chill criteria.
Current temperatures range from the upper 30s to the lower 40s across this area. Concerned that precipitation will change over to freezing rain and/or sleet as temperatures drop to or slightly below freezing. Will update to add rain chances for the remainder of the evening hours and change precipitation type to rain, freezing rain or sleet after midnight. 5 degrees F which would likely result in snow while the NAM has a much warmer warn nose over 5-6 degrees which would likely result in sleet. A broad deep trough that spans most of the country will remain in place centered roughly over the Great Lakes.
High pressure is centered across the northern Plains, with very cold air gradually building southeast into the lower Ohio Valley. Another mostly cloudy day has been on tap for eastern Kentucky, with temperatures ranging from the low to mid 30s across the area. Some of the higher resolution models suggest a glancing blow of measurable snowfall north of I-64, but given the dry low levels and weakening trend to the mid-level short wave, will keep POPs low. A gradient of warmer readings will be found towards the Tennessee/Virginia border, where lower 20s will be more common.
Hi pres over the Carolinas will be absorbed and pulled west by a much stronger ridge pushing out of the Northern Plains.
High pressure aloft along the west coast will maintain a dry and mild west-northwest across much of Utah over the next several days.
Short range models have been very consistent in bringing in drier air at the low levels and in weakening the frontogenesis over the area. The 12z GFS is an outlier regarding a deep trof digging into the wrn Plains this weekend as the low currently south of AK phases with a trof currently over Hudson Bay region. For now, have kept PoPs capped in the low chance range with limited precip.
Patchy freezing drizzle may develop across mainly the Big Country this evening, possibly affecting KABI. Very cold temperatures with areas of freezing drizzle across the Big Country. Light drizzle, some freezing, was indicated by the Dyess AFB radar. Icy bridges and overpasses will be the main concern tonight, especially along and north of I-20, where temperatures will be in the 20s. Freezing drizzle amounts will be mainly trace amounts, but even these amounts could produce hazardous conditions. Went 2-3 degrees cooler than most short range MOS guidance Wednesday with cloudy skies and strong cold advection.
East to Southeast winds have also picked up this evening helping to somewhat clear the low clouds and fog.
With high pressure sitting over the area on Wednesday, high temperatures will likely stay in the single digits to teens.
531 PM CST Tue Dec 26 2017 Tonight: This afternoon, a deep upper-deck low continued to cover Ontario but was weakening while upper-deck ridging was punching NNW from just off the Pacific Northwest Coast to the Gulf Of Alaska. The GFS takes a MUCH STRONGER & FASTER approach on the SE track of the Arctic High, bringing it as far south as the Nebraska/Kansas state line late New Year's Eve night & early New Year's Day morning whereas the ECMWF brings it only as far as the Dakotas/MN with the attendant inverted ridge reaching as far as around the IA/MO state line.
Areas along and north of I-94 where temps will be colder are more of a slam dunk for meeting wind chill criteria, where as areas south are more borderline given slightly "warmer" temps and the expectation of light winds. High temps will be around 3-5 degrees warmer than today, mostly from zero to 10 above.
5 degrees F which would likely result in snow while the NAM has a much warmer warn nose over 5-6 degrees which would likely result in sleet. A broad deep trough that spans most of the country will remain in place centered roughly over the Great Lakes.
In the mountains, breezy conditions over the peaks and ridges are probably producing the patchy blowing snow that is in the forecast already, so will not make any changes up there. Expect warmer temperatures on the plains on Wednesday given the stronger downslope flow. Continued NW flow aloft over the state will keep light snow possible in the higher mountains through the weekend.
Arctic high pressure centered from northwest North Dakota through southeast South Dakota this afternoon will propagate east to be centered just east of the I-29 corridor by Wednesday morning. This is not too far from the 12 UTC global consensus for lows for tonight, but, above the lowest edge of the forecast envelope which so far has not verified well on a large scale across the area.
426 PM MST Tue Dec 26 2017 Broad upper trough continues across much of the CONUS, with the area under deep northwest flow. Surface analysis shows strong arctic high pressure across the Dakotas with southerly low level flow developing over the last few hours.
Dry west-northwesterly flow aloft with high pressure along the California coast will continue for the next several days. Extended range models show high pressure weakening by the weekend with daytime temps cooling a bit for the Northland.
Otherwise, temperatures will generally be seasonable with warmer than normal daytime highs over the interior.
Strong Arctic high pressure ridge will build into the area progressively over the next 12 to 24 hrs and will help overnight temperatures plummet to well below zero especially north of I-70.
/ISSUED 346 PM CST Tue Dec 26 2017/ Low amplitude trough and associated ascent continues to shift away from east TX this afternoon, pulling weak showers with it. This will also aid in shifting reinforcing cold front now moving into central TX offshore tonight. Overall should see a trend towards somewhat warmer weather into late week/early weekend before yet another cold front ushers in return to much below normal temps to start the New Year. Winds will veer to more of an easterly direction later in the week as high pressure moves away.
We still see a slight opportunity for isolated flurries overnight as weak isentropic lift in the 275k layer combines with a slight increase of low level moisture, especially given the lower level of the DGZ.
With the northern areas cold enough that it will only be flurries, and the southern areas will be in the mix of flurries and freezing drizzle. Freezing drizzle has been reported on elevated surfaces, like web cams and windshields. By Wednesday afternoon warmer air from the west will start to invade the Panhandles.
Clouds are expected to increase from the west to east Wednesday morning as the 850mb ridge shifts to the east and we start seeing return flow. Increasing clouds will keep high temperatures on Wednesday in the low to mid teens.
941 PM CST Tue Dec 26 2017 Advisory for freezing drizzle was cancelled as much drier air has spread well south of the Red River.
Cold front currently making its way southward through the mid state.
High pressure will remain over the area for the next several days. Inversion conditions in the San Joaquin Valley have kept visibilities mainly in the 3 to 5 mile range while dry and mild conditions prevail over the higher elevations as a dry upper ridge strengthens off the CA coast.
A cold front will push through overnight and increase winds further, but will not clear out stratus deck. Persistent low stratus has remained across most of South Texas today, keeping temperatures on the cooler side this afternoon. An approaching cold front will move through the region overnight, bringing additional rain chances and colder weather to the region. Persistent CAA will allow temperatures to fall into the low to mid 40s most locations overnight, and upper 40s along the immediate coast.
526 PM CST Tue Dec 26 2017 Cold high pressure will drift across the area tonight, allowing for another very cold night/morning. As a relatively weak wave moves into the Central Plains on Wednesday the west and southwest flow in the low to mid levels will increase.
Cold high pressure remained across much of the region at 20z, extending from western Canada into the central plains. Most of the forecast area will experience some of the coldest temperatures so far this season tonight as the high sinks slowly southeast.
524 PM EST Tue Dec 26 2017 Some adjustments had to be made to account for a backdoor cold front that has crawled down the coast into the Jacksonville area. This has brought cooler temps and an overcast stratus layer to these areas, along with some slightly higher winds. The stratus layer will likely hold in place through the night and will eventually spread inland some overnight due to an inverted trough just offshore. Amendments were made to KSSI, KJAX, and KVQQ to account for overcast stratus layer that has slipped into the area behind a backdoor cold front. Winds/seas a little stronger in the northeast flow around the inverted coastal trough.
A ridge of high pressure to the west southwest will keep things mostly quiet today and tonight.
There are still difference on how far northwest this moisture will push but the general consensus is that the southeastern third to half of the area could see dewpoints climb into the low 40s by sunrise tomorrow. Even with the warmer temperatures, RH values will stay between 15 to 20 percent on the Caprock with near 30 percent for the Rolling Plains and wind speeds will be a bit lower than today which should help a bit with the fire danger.
1117 AM EST Thu Jan 25 2018 Dry high pressure over the region today will move off the coast Friday. A cold front will bring rain to the region over the weekend.
316 PM CST Thu Jan 25 2018 The main forecast challenge over the short term is temperature as an upper ridge breaks down and a surface cold front comes through. Perhaps the bigger factor on lows will be the 10C+ thermal ridge exiting the area and strong 40kt southwesterly flow at H85. Kept the Platte River Valley cooler as there will be less mixing and more of a drainage effect. The cold front clears the forecast area by 12z, so CAA takes over throughout the day. Kept highs on the cooler end of guidance, especially with the snow pack, resulting in upper 30s panhandle and lower 40s elsewhere. Did introduce schc -SN along the Pine Ridge during the morning for terrain enhanced lift and remnant surface moisture.
149 PM MST Thu Jan 25 2018 The forecast area will be under southwest flow aloft tonight ahead of an upper trough and associated cold front that move through Friday.
318 PM CST Thu Jan 25 2018 A se wind of 5 to 10 mph today as high pressure has shifted into the southeast states.
Forecast confidence is medium to high: High pressure will continue to exit to the east tonight ahead of an approaching trough. Could see sprinkles or a few rain showers as the trough and associated front move though Friday evening into Friday night.
248 PM CST Thu Jan 25 2018 Tonight and Friday: Temperatures have climbed into the lower 60s over the central and southern portions of the area resulting in relative humidity values near 25 percent. Mid afternoon surface analysis had a 1033mb ridge axis nosing across our CWA from the northeast. Together these features will lead to a slow moisture increase and slightly warmer than normal temperatures again.
Without snow, this would be a situation with sunshine and warmer temperatures for all. However, the thick snowpack from the winter storm earlier this week is cooling the lowest layers of the atmosphere causing some areas in southwest Minnesota to remain cloudy, with patchy fog lasting into the late afternoon. This evening, patchy fog may re-develop briefly, but after midnight, a strengthening surface gradient will increase wind strength and cause a subtle shift to more southerly wind direction ahead of an approaching upper-level trough. This should minimize the upslope component of surface flow relative to the Buffalo Ridge; along with deeper mixing, this should reduce chances for dense fog overnight into Friday morning. During Friday morning the shift to southwesterly winds will lead to a brief period of downslope wind enhancement for areas on the eastern slope of the Buffalo Ridge.
Warm air pushing into the CWA this afternoon ahead of a cold front has made it to higher elevated bare ground areas while snow-filled valleys of the Milk, Missouri and Yellowstone are struggling to rise through the 20s.
1209 PM CST Thu Jan 25 2018 Dense fog is currently lingering on the eastern half of the Buffalo Ridge, but other areas have seen improvement in visibility. Upper ridge axis tracks across the Plains today, with upper level flow turning southwesterly by this evening ahead of a trough digging into the northern Rockies. Unseasonably warm temperatures will continue into Friday, as a trough moves into the northern and central High Plains.
Overnight, the PAH forecast area will be under a brief period of ridging aloft, followed by a minor perturbation in southwesterly mid level flow Fri. In this warm advection pattern, lows will be above freezing tonight, and highs Fri are forecast to be quite similar to today, in the middle to upper 50s. As a cold front, with its parent low near the Canadian border, approaches the PAH forecast area Fri night, clouds will rapidly increase from west to east, along with PoPs, especially after midnight.
1211 PM EST Thu Jan 25 2018 Aviation A mix of light snow and freezing drizzle is possible through the morning with isolated slick spots possible where the precipitation is more persistent.
1113 AM EST Thu Jan 25 2018 Hydro A mix of light snow and freezing drizzle is possible through the morning with isolated slick spots possible where the precipitation is more persistent.
251 PM CST Thu Jan 25 2018 Cirrus a bit thicker than forecast and an east wind has brought slightly cooler temperatures from the bay into the eastern half of the forecast area today. Considerably warmer temperatures are expected tonight as clouds develop during the mid evening. Its still dry aloft but the low levels look moist enough to generate some showers.
In the low levels, a deepening lee trough over the northern High Plains will develop into a cyclone which will move into northern MN by Friday afternoon, while a trailing cold front advances southeast into the mid-MO Valley.
1234 PM EST Thu Jan 25 2018 High pressure over the region will move off to the eat Friday.
1255 PM EST Thu Jan 25 2018 Dry high pressure over the region today will move off the coast Friday. A cold front will bring rain to the region over the weekend.
A progressive upper tropospheric pattern will be present through the period with longwave ridging over the central U. translating eastward and a Pacific NW trough following in its wake by midday Friday. As this trough approaches, the surface pressure gradient over the state likewise increases overnight; aiding in keeping winds up in the 10 to 15 kt range and holding lows in the lower 40s. A weak cold front slides southeastward through the CWA on Friday late afternoon. A band of 800-900mb Fg forcing concurrent with the passing cold front may generate some rain Friday night over portions of east central Kansas, but amounts look to be light and the chance of rain ends before midnight as the front advances eastward.
With mixing, this could potentially bring central Oklahoma dewpoints down into the lower teens this afternoon. So have populated today's dewpoints very much on the low side of the range of model forecasts today, close to the ECMWF.
Aloft - Troughing on both the western and eastern U. seaboards with ridging extending over the eastern plains to Canada all slide east. An Atlantic ridge over Cuba builds into the Gulf of Mexico and FL tonight then northward Fri. amplifying the Plains ridge when it reaches the east U. Surface - High pressure centered along the MS/AL border tracks east-northeast. A cold front moving across the western states will stretch from the Upper Great Lakes to the southern high plains by Fri afternoon. The ridging. with the lower values in the north.
Winds should pick up again going into this evening as an LLJ sets up ahead of the cold front progressing through the region tomorrow morning. /Issued 345 AM CST Thu Jan 25 2018/ An upper low over northern Mexico is expected to move northeastward across Texas today. Tomorrow a cold front remains on track to drop southward across the area.
1245 PM EST Thu Jan 25 2018 Flurries should continue until high pressure returns dry weather later this morning through Friday.
1100 AM CST Thu Jan 25 2018 252 AM CST Fair and mild conditions are in store today and tonight as 1035 mb high pressure slides east. The influence of troughing west to the west over the Plains will tighten the pressure gradient enough for sustained south and southeast winds of about 10-15 mph with gusts up to 20-25 mph south of I-80 during daylight hours.
A slow moving cold front continues to bring moderate snow to portions of southwest Montana this afternoon.
Vort max on the backside of the Pac NW trof will move into the CWA this afternoon and evening so showers will spread over the CWA. JHM Much of interior NorCal is seeing a relative break early this morning as precip associated with the front has shifted into central California while showers are spreading across NW California ahead of the approaching upper trough. Showers, along with a few thunderstorms (small hail will be the primary threat), will increase across the region today as the upper trough moves overhead.
The upper high pressure ridge moving into the region from the west will help warm temperatures today. The high center wl cont to shift eastward away fm the region, with south winds further increasing the next few days. By Fri ngt, a new cold front wl apch NW AR with better rain chances returning to most of the FA.
Looking ahead, temperatures will cool on Friday behind a cold front, but it will still be mild for January with highs in the 40s and 50s.
TFJ Aside from very patchy freezing fog in deeper river valley locations early this morning, the other observation point is high cloudiness streaming across the region at times as indicated by satellite imagery. A large upper ridge previously over the western U.
1058 AM CST Thu Jan 25 2018 Warm front is still lingering to the southwest along the mid Mississippi River Valley this morning, but winds out ahead of it are also out of the south/southeast. High pressure will continue to drift eastward into the Appalachians, allowing a southerly return flow to bring warmer conditions to central Illinois today. Thanks to continued southerly flow, lows tonight will be warmer than in recent nights. with readings remaining in the lower to middle 30s. As a cold front begins to approach from the northwest on Friday, the pressure gradient will tighten across the Midwest.
An upper level ridge is moving east away from the area, with a weak disturbance to our south bringing elevated dry thunderstorms to west central Texas. Southwesterly flow will transition to westerly and northwesterly flow over the weekend as a long wave ridge establishes itself out west.
As the high shifts offshore, warmer temperatures are expected to develop Friday through the weekend, along with the chance for valley rain and mountain snow showers. With mostly clear skies temps are on track to be a couple of degrees warmer than forecast so i made a small adjustment up in the very near term to temps. Otherwise high pressure continues building and its a pleasant North Country Day blue bird day. Coldest day of the week is in the forecast for today as we remain under the influence of an East Coast upper trough and north-northwesterly low/mid-level flow. Daytime temps will range through the low/mid teens, while tonight's lows will dip into the single digits above and below zero as skies clear out and winds abate.
As winds remain from the south/southeast this evening, the low clouds and fog will likely persist, and models have been having a hard time drying the boundary layer out too fast. Otherwise, a cold front will move across the area Friday afternoon/evening, and drop our temperatures back to near or below normal for the weekend. As previously said, a cold front will move across the area Friday afternoon/evening, dropping temperatures back to near or below normal for this weekend.
Winds will be out of the southwest for the majority of the TAF period becoming more westerly toward the end of the TAF period ahead of an approaching cold front. Winds will then begin to shift to more westerly around 16Z with sct high clouds moving in as well along the approaching cold front. Winds should pick up again going into this evening as an LLJ sets up ahead of the cold front progressing through the region tomorrow morning. /Issued 345 AM CST Thu Jan 25 2018/ An upper low over northern Mexico is expected to move northeastward across Texas today. Tomorrow a cold front remains on track to drop southward across the area.
Surface wise, a huge area of high pressure is over the Eastern United States, most of the Gulf of Mexico and the Florida peninsula.
On Friday, the downslope-modified cold front tied to the storm system will move across western Kansas, with a gradual wind shift from southwest to northwest around midday.
238 PM EST Thu Jan 25 2018 High pressure exits tonight, allowing a southwest flow of milder air to start the weekend.
Lows tonight will drop into the middle 30s to the lower 40s. The disturbance will help to increase cloud cover across the area which will result in highs being slightly cooler Friday, with readings in the middle to upper 50s. An upper level trough will push across the Plains on Friday and then the area Friday night. Light rain is expected to develop ahead of the trough and spread east across the region.
1043 AM MST Thu Jan 25 2018 Current surface analysis shows low pressure over southeast Alberta, with warm front extending southeastward into the Northern Plains, north and east of most of the CWA. Upper level analysis shows ridge axis now over the high plains, with long wave trough and area of low pressure along the Pacific NW coast. High clouds continue to push over and through the ridge, bringing variably cloudy conditions. The cold front will arrive over northeast WY late this afternoon and push east-southeast across the rest of the area during the evening hours.
Overnight lows should also be much warmer compared to this morning, both due to the overcast skies and southerly flow.