Aikyam-Lab/Synoptic-Bench huggingface dataset:
The upper level closed low is now near the Bahamas with a ridge extending from the Lower Mississippi River Valley northwards into the Great Lakes. The ridge axis will move across the area late tonight into Christmas morning. Overnight lows will be well above normal with temperatures on Christmas morning starting out in the low to mid 40s for most locations. The ridge axis will shift slightly to the east of the area on Christmas Day. Very strong ridge of high pressure is the dominant feature at the opening of the forecast period.
1234 PM EST Tue Dec 24 2019 High pressure provides dry and relatively warm conditions through the Christmas Holiday. Rain chances increase over the weekend with a cold front. High pressure in control with dry and warm conditions. A few degrees warmer on Wednesday, as strong upper ridge continues to build across the area.
Our area is under southwest flow aloft, and the mean position of an upper trough will remain over the western CONUS. Highs on Wednesday will be mostly in the lower 70s.
1142 AM CST Tue Dec 24 2019 The mid/upper ridge over the central CONUS is progged to translate slowly eastward over the Mississippi Valley area today and into the Ohio and Tennessee Valley areas by tonight.
Winds will continue into Christmas day with warm air advection omngoing as low pressure remains west of the area.
An upper-level ridge is beginning to settle in behind the feature across the state, aiding in the advection of cooler and drier air.
235 PM CST Tue Dec 24 2019 The pattern across the Nation today is a bit amplified, with the juxtaposition of a trough across the far western states and a ridge across the eastern 2/3 of the CONUS, inducing a southwest flow over the Plains States.
213 PM EST Tue Dec 24 2019 An anomalous upper level ridge will continue to bring a lack of cloud cover and mild temperatures to the region for the next couple days.
An upper trough will move across the area tonight, weakening as it moves into the Central Plains so its only effect will be to give the Guadalupe Mountains a slight chance for showers.
Upper trof over the western coastal states with moisture streaming north across the Rockies and northern Plains. The remainder of the week will feature split flow with a semi closed low over the desert southwest and the Pacific jet pushing into the northern Rockies.
Currently, southwest flow aloft with an upper level ridge over the eastern CONUS and a long wave trough across the west. Light snow and freezing drizzle continue to be the main feature for the Christmas holiday period.
121 PM EST Tue Dec 24 2019 High pressure will keep mild and clear weather over the area through Christmas.
250 PM CST Tue Dec 24 2019 Another mild yet cloudy day occurring across the area this afternoon with high temperatures sitting in the middle 30s to 40s as upper ridging remains in control. Some brief periods of freezing drizzle will be possible across areas mainly north of I-90 during the morning hours where temperatures may be near or below freezing. However, once temperatures warm throughout the morning/day, the chance for freezing drizzle will become minimal.
234 PM CST Tue Dec 24 2019 Ridging currently over the area making for a nice afternoon. Heights will begin to fall as a trof digs into the western U.
High pressure is expected across the area through the end of the week. A low pressure system may affect the area over the weekend. Strong upper ridging expected to hold over the local area, while upper troughing holds over the western parts of the country through the short term.
205 PM MST Tue Dec 24 2019 The northern plains remain in southwest flow, with the upper trough covering the western CONUS. As light upslope flow continues tonight and RH increases, expect freezing fog/freezing drizzle to expand across the western SD plains. Confidence is low as to whether shear will be enough for freezing drizzle, but freezing fog looks more likely. Surface winds will become northerly as the low slides across NE, allowing fog to gradually dissipate.
547 PM CST Tue Dec 24 2019 VFR conditions will prevail across the terminals this evening and early on overnight with high pressure in place across the region. /Tonight through Wednesday night/ The building upper ridge has scoured out much of the morning cirrus with a great view on the visible imagery. The big trough out West is plugged into this machine with the Southwest flow in the mid deck over West Texas. The warmer air spreading in over cooler ground will be turning on the fog machine each night.
430 PM MST Tue Dec 24 2019 The northern plains remain in southwest flow, with the upper trough covering the western CONUS. As light upslope flow continues tonight and RH increases, expect freezing fog/freezing drizzle to expand across the western SD plains. Confidence is low as to whether shear will be enough for freezing drizzle, but freezing fog looks more likely. Surface winds will become northerly as the low slides across NE, allowing fog to gradually dissipate.
Forecast Summary: The forecast's primary concerns are the opportunity for some light freezing drizzle early Christmas morning and the likelihood of both rain and snow this weekend. Otherwise, near record high temps in southern portions of the area on Wednesday will be replaced by cooler temps for the remainder of the next 7 days.
/Tonight through Wednesday night/ The building upper ridge has scoured out much of the morning cirrus with a great view on the visible imagery. The big trough out West is plugged into this machine with the Southwest flow in the mid deck over West Texas. The warmer air spreading in over cooler ground will be turning on the fog machine each night.
Thanks to high pressure from the surface up, Christmas Day will be another nice but unusually warm day. A ridge pattern will continue through this taf period with VFR expected.
800 PM EST Tue Dec 24 2019 An anomalous upper level ridge will continue to bring a lack of cloud cover and mild temperatures to the region for the next couple days.
217 PM MST Tue Dec 24 2019 Early afternoon WV/IR imagery depicted a upper trough over the Intermountain West and upper ridge centered over the MS Valley. A quasi-stationary front extended from the Midwest through NE to the MT/WY border, then south to a low pressure center over western AZ. Accumulating snowfall is likely, especially over the higher elevations through Christmas evening. Light snow showers will spread east onto the high plains later Christmas afternoon and evening, with less than a half inch. High temperatures Christmas Day will be 5 to 10 degrees cooler than today. The GFS & ECM are in agreement with a 4 Corners closed low being absorbed by a sharp short wave diving south across the Northern Plains. No fire weather concerns with cooler temperatures, lingering snow pack, and chances for additional snow through Christmas evening.
First of all, the temperatures are near or below freezing at the surface for lows tonight. With the front drifting through the southeastern part of the forecast area, the temperatures will be cooler in the northwest than in the southeast.
Tonight and Wednesday The main foci of the short term are the fog trends through tomorrow, and the freezing drizzle potential tonight into tomorrow. Temperature wise, conditions remained above normal, so stuck with the warmer guidance once again.
/issued 234 PM CST Tue Dec 24 2019/ Ridging currently over the area making for a nice afternoon. Heights will begin to fall as a trof digs into the western U.
725 PM EST Tue Dec 24 2019 An anomalous upper level ridge will continue to bring a lack of cloud cover and mild temperatures to the region for the next couple days.
355 PM CST Tue Dec 24 2019 Upper ridge axis across the Southern Plains was pushing off to the east this afternoon. southerly winds 5-15 mph and the scattered cirrus clouds should continue across CWA as a longwave trof holds over the West Coast allowing for the upper level southwesterly flow to remain over the Southern Plains.
518 PM CST Tue Dec 24 2019 The pattern across the Nation today is a bit amplified, with the juxtaposition of a trough across the far western states and a ridge across the eastern 2/3 of the CONUS, inducing a southwest flow over the Plains States.
340 PM CST Tue Dec 24 2019 Currently, a weak trough of low pressure exists from N to S across MN. The high shifts east across southern Canada tonight and into tomorrow. and we will see an increased chance for some light freezing drizzle out of the fog/clouds as Christmas day goes on tomorrow. The best chance for precip will be tomorrow night when it's expected to start as freezing rain/drizzle and change over to snow in the evening.
Winds will continue into Christmas day with warm air advection ongoing as low pressure remains west of the area.
A deep layer ridge of high pressure will build across the forecast area through tonight before shifting eastward across the Eastern Seaboard and southeastern U. Highs on Christmas Day should once again range from around 70 to the lower 70s inland, and in the mid to upper 60s near the coast, which is around 10 degrees above normal for the date.
The northern plains remain in southwest flow, with the upper trough covering the western CONUS. As light upslope flow continues tonight and RH increases, expect freezing fog/freezing drizzle to expand across the western SD plains. Confidence is low as to whether shear will be enough for freezing drizzle, but freezing fog looks more likely. Surface winds will become northerly as the low slides across NE, allowing fog to gradually dissipate.
700 PM EST Tue Dec 24 2019 Current surface analysis shows the low pressure system that had been impacting the area over the last few days has pushed far southeast of the forecast area. For the rest of the short term forecast, high pressure will build into the area both aloft and at the surface.
717 PM EST Tue Dec 24 2019 An area of low pressure surface and aloft persists east of the Florida peninsula. The area of low pressure will shift east of the area tonight.
535 PM CST Tue Dec 24 2019 Another mild yet cloudy day occurring across the area this afternoon with high temperatures sitting in the middle 30s to 40s as upper ridging remains in control. Some brief periods of freezing drizzle will be possible across areas mainly north of I-90 during the morning hours where temperatures may be near or below freezing. However, once temperatures warm throughout the morning/day, the chance for freezing drizzle will become minimal.
516 PM CST Tue Dec 24 2019 Currently, a weak trough of low pressure exists from N to S across MN. The high shifts east across southern Canada tonight and into tomorrow. and we will see an increased chance for some light freezing drizzle out of the fog/clouds as Christmas day goes on tomorrow. The best chance for precip will be tomorrow night when it's expected to start as freezing rain/drizzle and change over to snow in the evening.
Low pressure system dropping south along the coast will spread a few showers over NorCal late tonight into Christmas day. Snow levels will be quite low with this system down to 2500 feet, but the low moisture amounts will only give 1-3 inches over the Sierra.
Temps/dewpoints expected to remain at or above 32F and no freezing fog/ice accretion is anticipated given marginal temps. Upper level ridge axis shifts slowly eastward and surface winds become more southerly with better WAA for a quick temperature recovery.
41 Current surface analysis shows the low pressure system that had been impacting the area over the last few days has pushed far southeast of the forecast area. For the rest of the short term forecast, high pressure will build into the area both aloft and at the surface.
630 PM EST Tue Dec 24 2019 High pressure provides dry and relatively warm conditions through the Christmas Holiday. Rain chances increase over the second half of the weekend as a cold front approaches. High pressure in control with dry and warm conditions. A few degrees warmer on Wednesday, as strong upper ridge continues to build across the area. Continued quiet weather expected during the remainder of the week as mid level ridging maintains an influence on the region.
Otherwise, VFR conditions with surface ridging producing light winds through the period. Chattanooga Airport, TN 45 66 42 64 48 / 0 0 0 0 10 Knoxville McGhee Tyson Airport, TN 43 66 40 62 45 / 0 0 0 0 10 Oak Ridge, TN 43 65 40 62 45 / 0 0 0 0 10 Tri Cities Airport, TN 39 65 38 64 43 / 0 0 0 0 10.
Widespread snow and rain showers will continue through late this evening, with snow showers continuing mainly over the higher terrain on Christmas Day.
Tuesday ended up cooler than expected due to persistent fog and low clouds.
354 AM EST Wed Dec 25 2019 The morning surface analysis shows high pressure nosing southwest toward eastern Kentucky from the Mid Atlantic. In the upper levels ridging is extending northwest from the southeastern US. We have seen some ridge riding cirrus through the night and that continues to push east based on the GOES-16 suite of products. This will lead to warmer temperatures on the ridges than advertised by the NBM, but there will be a 10 or more degree split seen in the eastern valleys.
1007 PM EST Tue Dec 24 2019 An anomalous upper level ridge will continue to bring a lack of cloud cover and mild temperatures to the region for the next couple days.
1235 AM EST Wed Dec 25 2019 An anomalous upper level ridge will continue to bring a lack of cloud cover and mild temperatures to the region for the next couple days.
With temperatures below freezing, some of the bridges and overpasses could become slick overnight. The low level clouds should make it to about I80, thus there may be enough moisture for some sprinkles or light rain along/north of I80. This wave lifts northward through the area pretty quick, and some of this will fall where surface temperatures remain above freezing along the I80 corridor. Generally trace amounts could occur north of a line from Columbus to Wayne where temps would be below freezing. Surface temperatures drop to below freezing at KOFK about the same time so will have to watch out for freezing fog developing with visibilities down to 1 mile at times. At KLNK/KOMA, could see temporary MVFR conditions at KLNK/KOMA 13-15z, but temps remain above freezing at these locations.
It should be a warm Christmas for southwest Kansas as southwest winds will combine with some sunshine and highs reach into the low to mid 60s.
902 PM MST Tue Dec 24 2019 Patchy fog and low clouds have established for the Baker, Long, and Upper Treasure/Magic Valleys this evening in the wake of the low pressure system.
1037 PM EST Tue Dec 24 2019 A cloud band with a few light showers has been pivoting southward through the Lower/Middle Keys this evening, on the back side of an exiting low pressure center well northeast of the northernmost Bahamas. Meanwhile, a mid-level ridge will build north from the western Caribbean, bringing warmer air aloft.
Ridging at the surface and aloft will provide a pleasant day across the tri-state region. Afternoon high temperatures are expected to range from the mid 60s across the northern portions of the area to the low to mid 70s across the Florida panhandle and big bend.
Temperatures should remain in the low to mid 20s across most of the area.
1010 PM EST Tue Dec 24 2019 The multi-layer low pressure system to the east of Florida this evening will continue to move away from the local area.
1030 PM CST Tue Dec 24 2019 Another mild yet cloudy day occurring across the area this afternoon with high temperatures sitting in the middle 30s to 40s as upper ridging remains in control. Some brief periods of freezing drizzle will be possible across areas mainly north of I-90 during the morning hours where temperatures may be near or below freezing. However, once temperatures warm throughout the morning/day, the chance for freezing drizzle will become minimal.
With temperatures below freezing, some of the bridges and overpasses could become slick overnight. The low level clouds should make it to about I80, thus there may be enough moisture for some sprinkles or light rain along/north of I80. This wave lifts northward through the area pretty quick, and some of this will fall where surface temperatures remain above freezing along the I80 corridor. Generally trace amounts could occur north of a line from Columbus to Wayne where temps would be below freezing. Could also be a few spotty showers at KOFK 10-13z, with temperatures below freezing. VFR conditions expected at KLNK/KOMA, with the low clouds staying just to the north. Couldn't rule out a sprinkle at these two locations, but temperatures would be just above freezing and thus no real impacts.
An upper level trough will weaken as it slowly moves east over the next couple of days. Impacts from this weakening trough will be felt across Utah through Christmas day. In fact RAP analysis shows 700mb temperatures at or below -8C confined to Nevada and this will likely remain the case through the remainder of the evening, until the next weak feature currently rotating through the lower Colorado River valley lifts northeast.
1151 PM CST Tue Dec 24 2019 The pattern across the Nation today is a bit amplified, with the juxtaposition of a trough across the far western states and a ridge across the eastern 2/3 of the CONUS, inducing a southwest flow over the Plains States.
159 AM EST Wed Dec 25 2019 An anomalous upper level ridge will continue to bring a lack of cloud cover and mild temperatures to the region for the next couple days.
CDG Chattanooga Airport, TN 66 42 64 48 64 / 0 0 0 10 10 Knoxville McGhee Tyson Airport, TN 66 40 62 45 61 / 0 0 0 10 10 Oak Ridge, TN 65 40 62 45 61 / 0 0 0 10 10 Tri Cities Airport, TN 65 38 64 43 60 / 0 0 0 10 10.
1027 PM CST Tue Dec 24 2019 06Z TAF issuance VFR with winds becoming west behind a cold front this morning.
238 AM MST Wed Dec 25 2019 Areas of dense freezing fog and a few light snow showers will linger through Christmas morning before skies begin to clear from the north and west. Weak flow at the surface and aloft combined with abundant low-level moisture continues to result in large swaths of dense freezing fog across north-central and parts of southwest Montana. Meanwhile, over southwest Montana skies are likely to remain on the cloudy side with continued patchy light snow and some areas of freezing fog lingering through tonight.
Areas of accumulating snow and rain at the lowest elevations will continue today as an additional weather disturbance slips across northern Arizona.
323 AM MST Wed Dec 25 2019 Freezing fog continues to be a concern across northeast Montana along with associated riming and possible slick road conditions. Look for a continuation of colder temperatures through the balance of the week as the main upper trough across the western U. Maliawco Look for IFR to LIFR conditions at times through at least 18Z this morning due to freezing fog and low ceilings.
In addition to the widespread clouds cover, areas of freezing fog are being observed especially across the Magic Valley.
540 AM EST Wed Dec 25 2019 An anomalous upper level ridge will build over the eastern conus the second half of this week.
An additional inch or two will be possible for the lower elevations of Carbon County, with 6-12 inches likely for the Sierra Madres. A few pockets of 1-2 inches are possible over some higher terrain areas including the Pine/Cheyenne ridges.
The formidable low pressure system well northeast of the extreme Northwest Bahamas early this morning, will move quickly eastward pulling a low level speed convergence boundary associated with higher moisture through our region tonight. For the balance of this week, a large region of high pressure centered over the eastern United States will slide eastward, resulting in a freshening and veering easterly flow. High temperatures will average in the mid 70s today, before moderating into the lower 80s on Thursday and near 80 degrees due to considerable clouds and a few episodes of rainfall. For this weekend, medium range guidance is in good agreement with the large western Atlantic ridge axis dropping southward and down the Sunshine State.
On the weather map, a broad longwave trough continues across the western US, with a strong ridge located over the Gulf of Mexico. As high clouds push east of the region today, the airmass should remain rather mild for this time of year, although similar to yesterday, with highs in the low to mid 70s.
Upper level ridge in upper levels and southwesterly flow in low levels will continue to produce well above normal temperatures with near record highs in the 60s on Christmas Day. Thursday morning a cold front will through the area which will lower temps about 10 degrees but still a good 10 to 15 degrees above normal.
The low stratus and fog is forecast to gradually mix out around 15Z-17Z, with VFR conditions thereafter. Southerly flow will continue tonight and lows Thursday will be warmer than today.
Forecast challenge for the short term will be the system moving through the region later today as an upper trough moves through the midwest. This could impact any travel christmas night, expecially near the coteau area, which could get around a tenth of freezing precipitation.
This boundary will hang around for most of the day tomorrow which will keep high temperatures 5-10 degrees cooler than today. By tomorrow night, an upper low will begin to deepen over Southern California and cause Gulf of Mexico moisture to be pulled westward into West Texas.
Areas of dense freezing fog and a few light snow showers will linger through Christmas morning before skies begin to clear from the north and west. Weak flow at the surface and aloft combined with abundant low-level moisture continues to result in large swaths of dense freezing fog across north-central and parts of southwest Montana. Meanwhile, over southwest Montana skies are likely to remain on the cloudy side with continued patchy light snow and some areas of freezing fog lingering through tonight.
Current surface analysis places low to the lee of the central Rockies, with ridging over Manitoba into northern Ontario. Upper level analysis places ridge over the eastern CONUS with trough over the west coast placing us in southwest flow. Still anticipate a possibility of a snow/freezing drizzle mix as forecast soundings continue to indicate a lack of ice aloft.
Southerly flow will continue tonight and lows Thursday will be warmer than today.
635 AM EST Wed Dec 25 2019 High pressure will remain over the region through Thursday.
Highs should be in the 60s to near 70 degrees, which is around 20-30 degrees warmer than normal for this time of year. Kanofsky Temperatures will remain above normal on Thu before a cold front moves into the region on Thu night and stalls across the southern half of MO.
Lee trough will deepen across the Plains this afternoon, with winds increasing across northeast Oklahoma and northwest Arkansas. Minimum RH values will again fall in the 30-35% range with the warmer weather. A cold front will move into northeast Oklahoma on Thursday. Cooler readings are likely across portions of Osage/Pawnee counties with an earlier frontal passage.
/Today through Thursday/ Upper-level ridge has shifted east of the region with southwest flow now prevailing aloft.
Our warmer than normal weather will continue today thanks to strong ridging over the eastern U. Skies will be mostly clear this morning, but as the upper ridge begins to break down we should see a few more clouds slide in from the west this evening and overnight tonight. Overnight lows tonight are expected to be several degrees warmer thanks to the cloud cover over the west and increased warm air advection.
For Christmas Day, it will be a bit breezy as the pressure gradient tightens from a developing lee cyclone over west-central Kansas.
Various Freezing Fog Advisories are in effect through later this morning to account for visibility less than one quarter mile at times.
Flight conditions will remain VFR through the rest of the day with southeast winds increasing as high pressure moves off to the east. With a 500 mb ridge moving off to the east and a deep trough moving into the western CONUS, Deep South Texas and the Rio Grande Valley will remain under weak surface ridging.