Aikyam-Lab/Synoptic-Bench huggingface dataset:
a narrow axis of 850-500mb moisture caught in between an upper level trough over the Great Lakes area and an upper level low over southern Nevada is forecast to slowly lift north tonight as the upper trough approaches. As the upper trough moves through tomorrow the axis of moisture moves east with it. Low temperatures are expected to be range from the mid to upper 20s in far eastern Colorado to the low 30s east of the CO/KS border.
As the valley's cool, higher terrain and locations along and west of the MS River my see enough mixing to keep temps above freezing overnight. NAM model depicts a 925mb pressure trof moving through the Midsouth overnight, with winds in excess of 10 knots either side. This appears borne out by KNQA VAD wind profiler showing southerly winds of 20 knots at 1 kft AGL just prior to 10 PM, ahead of the approaching trof off the surface. /issued 315 PM CDT Wed Apr 21 2021/ Expect another cold night across the Mid-South as Canadian high pressure will settle over the area. The high will shift east on Thursday and the upper flow is expected to be more zonal. Highs should reach into the lower to mid 60s.
Winds will veer to the northwest and north overnight as high pressure builds into the southeastern U. Cooler overnight temperatures tonight, as lows drop into the mid to upper 50s across the interior, with some traditionally cooler spots across the far north reaching in the low 50s, and low 60s across the coast.
A couple weak low pressure systems will drop down from the north through Thursday. Winds will decrease tonight but cooler temperatures will hold into Thursday.
Overall this should not impact the ongoing temperature forecast tonight with sub-freezing temperatures still on track with no changes planned to tonight's Freeze Warning headlines. Highs in the low to mid 50s and breezy west winds are expected, with plenty of sunshine helping it "feel" a bit warmer.
612 PM CDT Wed Apr 21 2021 Key Message: - Sub-freezing temperatures are expected late tonight into Thursday morning.
Precipitation tried to move in across the island chain, especially the Lower Keys but failed. Breezes will briefly slacken in the afternoon on Thursday before freshening to moderate to fresh late Thursday night as high pressure settles across the southeast U.
1017 PM EDT Wed Apr 21 2021 A strong cold front has passed through the region bringing gusty winds and falling temperatures.
Temperatures are already falling into the low 30s on the Plateau and, as winds become calm, we'll see most areas east of I-65 follow suit. Areas west of 65 will drop very close to freezing by early Thursday morning. A small shield of clouds over western KY will sink down into northwest Middle TN and could help stabilize temperatures just above freezing in that area, but widespread frost is still expected, even in areas that don't quite touch freezing. Tonight should be the last of the freezing temperatures.
Trough moving across the Red River Valley has shifted winds to a northwesterly direction and boosted temps into the 50s, with 40s still further east.
(Today and tonight) Zonal flow aloft will exist today, before becoming southwesterly tonight as an upper level trough moves down into the Four Corners region. Although some warmer air will come in from the southerly flow and overall warming of the air mass, the cloudy conditions today will keep temperatures on the cool side (highs in the low 60s).
Temperatures are already falling into the low 30s on the Plateau and, as winds become calm, we'll see most areas east of I-65 follow suit. Areas west of 65 will drop very close to freezing by early Thursday morning. A small shield of clouds over western KY will sink down into northwest Middle TN and could help stabilize temperatures just above freezing in that area, but widespread frost is still expected, even in areas that don't quite touch freezing. Tonight should be the last of the freezing temperatures. High pressure continues to build in from the west, and winds have finally diminished owing to a weakening surface pressure gradient.
420 AM EDT Thu Apr 22 2021 Cold and windy conditions are expected today as upper level low pushes across our area, snow showers will continue through much of the day, especially in the higher elevations.
Otherwise, mostly clear skies are being observed ahead of the trough to our northwest. The strongest wind gusts have been observed along and northeast of the higher terrain with speeds of 50-55 mph in locations such as Bellemont, Doney Park, and Taylor. Shower chances will progress to the east Thursday night as the trough passes through.
By early afternoon, the more substantial precipitation had shifted to the southeast of the area, however a trailing trough will be rotating through the forecast area this afternoon and tonight. We will be in- between weather systems Thursday with mid-level ridging. 12Z models all indicate that an upper level low will form overnight from this deepening system and then start to advance to the east. However, as it moves east, it will be advancing into the broad flow pattern around the large upper level low over western Quebec.
With a light SE wind through sunrise, and some extra cloud cover, temperatures at sunrise are expected to be a few degrees above freezing at most locations.
High pressure moving into the area today will move offshore Friday.
Subsidence associated with strong mid level confluence overhead on Thursday followed by short wavelength ridging on Friday will sustain dry conditions with limited cloud cover.
Temperatures have cooled quickly this evening, now ranging from the mid 50s over most inland areas to the lower 60s right along the coast. High temperatures on Thursday should be in the upper 60s and lower 70s, but likely feel a little cooler due to still somewhat gusty winds (especially down along the coast). a little warmer on Thursday night with temperatures in the mid to upper 40s across most of the area, but low to mid 50s near and along the coast. On Friday, with return flow look for temperatures mainly be in the middle 70s, but lower 70s over far northwestern zones due to increasing cloud cover and down at the coast where temps will be modified slightly by the cooler offshore waters.
241 AM CDT Thu Apr 22 2021 Some cloud cover has worked its way into the northwest, but elsewhere, temperatures have fallen rapidly to freezing and below freezing. Either way, much of the area is seeing freezing temps and even under the cloud cover, temps are cold enough for frost. Most of Friday will be dry, and a bit warmer as southerly winds bring some warmer air ahead of the next trough. The Plains trough will move east towards AR tonight, and precip will develop out ahead and move into the mid state Friday evening.
Thursday into Friday morning - High pressure will lead to mostly sunny skies, and the warmer temperatures aloft should keep the clouds from developing. With cloudy skies hanging on through the day high temperatures will be several degrees cooler than Thursday with highs in the low to mid 50s. A cold front then moves through from northwest to southeast Friday night with a slight chance of showers.
Trough moving across the Red River Valley has shifted winds to a northwesterly direction and boosted temps into the 50s, with 40s still further east. A rather potent cold front is scheduled to cross the forecast area Thursday night into Friday, dropping temperatures in the afternoon back to the 30s. Along and posterior to this cold front, some snow is possible, a dusting to perhaps a half inch at the outside.
Temperatures will be in the lower 80s across the eastern half of South Florida and upper 80s along the Gulf Coast. This flow will advect a warmer air mass into the area, as well as waves of moisture.
Garuckas Chattanooga Airport, TN 64 42 68 52 70 / 0 0 10 90 100 Knoxville McGhee Tyson Airport, TN 60 38 66 49 66 / 0 0 0 70 100 Oak Ridge, TN 60 38 65 47 65 / 0 0 0 70 100 Tri Cities Airport, TN 54 32 62 45 63 / 0 0 0 40 100 NC.
Winds have decoupled and are calm as high pressure builds into the area. Dewpoints have come up significantly over the past few hours from the low to mid 20s around sunset into the upper 20s to lower 30s in most locations. Some very patchy freezing fog is not out of the question in northern Alabama and southern middle Tennessee towards daybreak. Temperatures should rise more than today, into the low to maybe a few mid 60s, a good 10 or more degrees below seasonable norms. As the high slides to the east, not as cool for Thu night with lows from the upper 30s to lower 40s. The lower end of this could again support patchy frost development in those normally cooler areas.
256 AM EDT Thu Apr 22 2021 Upper air pattern consists of a 500 mb trough over the upper Great Lakes this morning and a trough in the Great Basin. Our upper trough will continue to head to the east adn into New England by 12z Thu. The Great Basin trough will head to the northern and central plains by 00z Fri. Friday, expect a warmer day.
A relatively unsettled pattern will continue through the work week with the second piece of the system over the Desert Southwest phasing with a weak Pacific Northwest trough during the day Thursday as they move across the forecast area through early Friday.
High pressure will provide mainly sunny skies today.
309 AM CDT Thu Apr 22 2021 Cloud cover has developed over our northeastern area otherwise temperatures continue to drop to near freezing across west Tennessee.
There isn't much in the way of lift during the day, but soundings do show that the troposphere moistens up considerably in the afternoon, behind a southward moving sfc cold front.
949 PM PDT Wed Apr 21 2021 Cold front drops into region overnight from the North.
452 AM EDT Thu Apr 22 2021 High pressure will build across the state today as a deep trough moves off the east coast. Seeing some freezing temperatures in the northwest this morning. Low temperatures tonight into Friday morning look to be a little warmer than this morning. there could be some values near freezing in the far northeast.
The low levels will begin to saturate late tonight across south central Kansas as moisture transport increases.
410 AM EDT Thu Apr 22 2021 A stalled out boundary that brought us gloomy, wet, and muggy start to our work week finally start to push south as high pressure moved in yesterday. This resulted in drier and slightly cooler air moving in. As we go throughout the weekend another cold front will be heading our way from the midwest.
428 AM EDT Thu Apr 22 2021 A late April cold snap will bring subfreezing temperatures and gusty winds early today and again early Friday morning.
Further south, dry and breezy conditions have prevailed with Red Flag conditions occurring across the lower elevations in southeast Utah and southwest Colorado. The backside of the upper level trough will finally lift across the region Thursday night with showers lingering into Friday morning, favoring the higher elevations. The current trough axis will be just over the CWA on Friday morning. Additionally, Friday will allow for a few showers mainly across the higher terrain near the Continental Divide.
Will also keep the Freeze Warning as is with temperature trends showing a quick decrease at sites exhibiting a calm wind on the last observations despite the high cloud cover.
149 AM EDT Thu Apr 22 2021 After a very cold early morning with temperatures in the 20s, high temperatures this afternoon will reach into the low 50s under mostly sunny skies. Lows tonight will once again be well below freezing before warmer weather returns Thursday into Friday.
Early Friday another weak upper trough is expected to emanate from the broader southwestern U. trough.
1044 PM CDT Wed Apr 21 2021 Key Message: - Sub-freezing temperatures are expected late tonight into Thursday morning.
142 AM EDT Thu Apr 22 2021 Upper air pattern consists of a 500 mb trough over the upper Great Lakes this morning and a trough in the Great Basin. Our upper trough will continue to head to the east adn into New England by 12z Thu. The Great Basin trough will head to the northern and central plains by 00z Fri. Friday, expect a warmer day.
330 AM CDT Thu Apr 22 2021 Freeze Warning will remain in effect until 13z for parts of northeast OK and northwest AR, where temps have dipped to near the freezing mark in some locations. Temps should quickly rise above freezing this morning. There is also a threat of heavy rainfall, especially near the warm front in southeast OK and along and north of advancing Pacific cold front into northeast OK.
Looking at long range trends, it seems this may be the last freeze warning of the season with low temperatures above freezing from here on out. Otherwise, focus will shift to an increasing chance for showers today as an upper trough moves across the Rockies.
Temperatures in the low 20s are currently being observed in Bad Axe. The combination of mostly clear skies and the resident cold airmass that moved into the region is supporting these sub freezing temperatures. A tightening pressure gradient north of this high pressure will be enough to support some gusty afternoon conditions as diurnal mixing depths increase to around 2 km. Westerly winds will begin to usher in warmer air across southeast Michigan throughout the day. Continued warming trend into Friday as the ridge dampens and more zonal flow is present throughout the column.
This is a result of a ridge and subsequent warm air advection that will occur from breezy southwest flow. The lack of moisture in the lower levels will result in low RH values around 20-25%. Rain will transition to snow Friday night as temps drop below freezing.
Low lying valleys known for being colder will likely again fall into the lower to middle 20s. Short range models show good overall consistency in digging the next system that is descending the Pacific upper ridge. While there are some differences in handling pieces of energy exiting the mean trough. Another byproduct of the low level jet will be increasing precipital water ahead of this system.
Broad H500 troughing was noted over the Upper Midwest w/ the FA under a regime of synoptic forcing for descent. Stagnant high pressure and calmer overnight winds wl certainly promote strong diurnal cooling across the north where near or at freezing temps are anticipated. As such, winds wl become more Srly and promote a poleward flux of Gulf moisture w/ Td's expected to return back to the low to mid 40s over the Srn half of the state by Fri morning.
415 AM EDT Thu Apr 22 2021 Snow moderate to heavy at times over the region will taper off to snow showers this evening as low pressure moves through New Hampshire. Cold and windy weather along with snow showers and flurries will continue later tonight into Thursday as the low moves away.
430 AM EDT Thu Apr 22 2021 A late April cold snap will bring subfreezing temperatures and gusty winds early today and again early Friday morning.
416 AM EDT Thu Apr 22 2021 Snow moderate to heavy at times over the region will taper off to snow showers this evening as low pressure moves through New Hampshire. Cold and windy weather along with snow showers and flurries will continue later tonight into Thursday as the low moves away.
Looking at highs to top off in the 50s with a few locations cracking into the low 60s.
High pressure at the surface translates west to east across the FA today, so another seasonally cool day even with sunshine is in store. Winds will be light, however, with the High's move across the region. As the high pressure ridge axis shifts to the east, return flow southerlies eventually develop.
This suggests 1 AM to 6 AM as the period with the peak risk for freezing temperatures. Temperatures in the 50s are expect Thursday, with highs in the lower 60s forecast on Friday. Over the Weekend: Guidance has generally backed off on the strength of a cold frontal passage Friday night, and this has implications for Saturdays forecast.
134 AM EDT Thu Apr 22 2021 A late April cold snap will bring subfreezing temperatures and gusty winds tonight into Friday morning.
A Freezing Fog Advisory has been issued for the I-80 Summit for the dense fog there and temperatures well below freezing. Gusty southerly winds across the High Plains over the course of the morning as the system ejects eastward over the Plains. Long range models continue to show a decent warming trend heading into the weekend, as a flattened upper level ridge axis progresses east into the Great Plains and amplifies.
443 AM EDT Thu Apr 22 2021 Temperatures will finally moderate today with highs rising close to 50 this afternoon as an upper level ridge builds into the area.
A trough axis will move in from the west early Friday, along with a cold front.
First, a patch of fog has developed as expected on the back side of a developing Denver cyclone circulation. It's actually warmer on the west side of this boundary, but also saturated. The showers should weaken as they move east over the cooler low level air, but some will make it over the Front Range cities this afternoon. Lows tonight on the plains will probably still be around freezing thanks to the clearing period.
This convergent line will be the focus for organized precipitation while more isolated to scattered precipitation develops in this conditionally unstable environment under the trough. However not really expecting much impact over roadways through the daytime with the bulk of the high snow accumulations limited to timberline or above. The focus the better precipitation chances migrate to the south this evening and overnight as the jet shifts southward and the base of this trough lingers. Several inches above 10kft agl is possible over the Southern mountains with some minor impacts along the Highway 550 corridor. Energy diving through the back of the trough will move over our CWA on Friday before warm advection on the nose of the ridge moves in to stabilize things out for the weekend. Again time of year will limit snow impact to the highest elevations tomorrow afternoon.
Some cloud cover has worked its way into the northwest, but elsewhere, temperatures have fallen rapidly to freezing and below freezing. Either way, much of the area is seeing freezing temps and even under the cloud cover, temps are cold enough for frost. Most of Friday will be dry, and a bit warmer as southerly winds bring some warmer air ahead of the next trough. The Plains trough will move east towards AR tonight, and precip will develop out ahead and move into the mid state Friday evening.
438 AM CDT Thu Apr 22 2021 A couple of cold fronts will bring the most significant weather during this period.
630 AM CDT Thu Apr 22 2021 Surface ridging square over the area this AM causing surface winds to be light and variable throughout the region. With the cool air mass in place, as well as clear skies and light wind temperatures are universally at or below freezing, and may drop another couple degrees by sunrise. For the rest of the day the weather will be quiet from an impact standpoint, but as the ridge slowly creeps eastward surface winds will become a little more predominantly southerly.
During the morning hours Friday a cold front will push south across the area with the chance for some light snow or rain showers to develop behind it within the CAA regime.
758 AM EDT Thu Apr 22 2021 Cold and windy conditions are expected today as upper level low pushes across our area, snow showers will continue through much of the day, especially in the higher elevations.
633 AM EDT Thu Apr 22 2021 Temperatures will finally moderate today with highs rising close to 50 this afternoon as an upper level ridge builds into the area.
1006 AM EDT Thu Apr 22 2021 High pressure moving into the area today will move offshore Friday.
Temps have remained much warmer than this time on Wed morning as a result of these increased clouds. There may be some struggle for temps to drop to near or below freezing across NRN sections of the CWA due to some increased clouds as well. confidence is decreasing in seeing another morning of widespread freezing temps in the current Freeze Warning area. This trough will provide some additional forcing.
616 AM CDT Thu Apr 22 2021 (Today and tonight) Zonal flow aloft will exist today, before becoming southwesterly tonight as an upper level trough moves down into the Four Corners region. Although some warmer air will come in from the southerly flow and overall warming of the air mass, the cloudy conditions today will keep temperatures on the cool side (highs in the low 60s).
Clouds will increase across north central and southwest Montana this morning as another cold front brings periods of rain and snow, along with gusty winds, and cooler conditions. Another upper level weather system and as associated surface cold front will sweep south-southeastward out of Canada this morning.
/Issued 330 AM CDT Thu Apr 22 2021/ Freeze Warning will remain in effect until 13z for parts of northeast OK and northwest AR, where temps have dipped to near the freezing mark in some locations. Temps should quickly rise above freezing this morning. There is also a threat of heavy rainfall, especially near the warm front in southeast OK and along and north of advancing Pacific cold front into northeast OK.
Dry today and Friday with temperatures trending warmer.
1035 AM EDT Thu Apr 22 2021 High pressure center will continue to build in from the west today. /Issued 725 AM EDT Thu Apr 22 2021/ High pressure will build across the state today as a deep trough moves off the east coast. Seeing some freezing temperatures in the northwest this morning. Low temperatures tonight into Friday morning look to be a little warmer than this morning. there could be some values near freezing in the far northeast.
954 AM EDT Thu Apr 22 2021 Mostly dry conditions are expected today with potentially impactful freezing temperature developing Friday morning.
331 AM MDT Thu Apr 22 2021 Cold front passage expected from late morning through mid afternoon across the CWA today. QPF amounts are not high, but could get a covering of snow across the more favorable upslope ridge tops of the southern zones. Upper trof across the northern plains/Canadian prairies will hold colder air over eastern Montana for Friday. Flat upper ridge slides across the intermountain west into the high plains over the weekend as an upper low moves into the Pacific northwest.
As our active pattern continues this week, winds will decrease for most locations today compared to yesterday with cooler temperatures.
725 AM EDT Thu Apr 22 2021 High pressure will build across the state today as a deep trough moves off the east coast. Seeing some freezing temperatures in the northwest this morning. Low temperatures tonight into Friday morning look to be a little warmer than this morning. there could be some values near freezing in the far northeast.
715 AM EDT Thu Apr 22 2021 A late April cold snap will bring subfreezing temperatures and gusty winds early today and again early Friday morning.
512 AM EDT Thu Apr 22 2021 A late April cold snap will bring subfreezing temperatures and gusty winds early today and again early Friday morning.
The Canadian cold front dropping out of Alberta is currently making its way into central Montana.
645 AM CDT Thu Apr 22 2021 Another morning of near to below freezing temperatures to start the day across the local area.
High pressure over the region will keep the dry weather in place for the next 24 hrs, with some cirrus moving in from the west. Light/variable to calm winds overnight will continue into the day, picking up more of an easterly fetch as the ridge axis drifts east this morning. Winds slowly veer to east/southeasterly by this afternoon, but return flow is a little slow in regards to warmer air or moisture working into the region.