Aikyam-Lab/Synoptic-Bench huggingface dataset:
The closed upper low will open up into a trough axis as it pivots across the lower Ohio Valley late tonight into Tuesday. Even more likely would be an increase in activity by late morning into the afternoon on Tuesday as the trough continues slowly churning east across the area. Our second system will be tied to a cold frontal passage on Wednesday as a low pressure system tracks by to our north across the Great Lakes. Timing differences remain, but currently it looks like the highest coverage for convection on Wednesday would be across west Kentucky. Moisture levels remain unseasonably strong for early September, leading to dewpoints in the low to mid 70s through Wednesday. The large scale pattern late this week into the weekend will feature troughing across the Ohio Valley/Appalachians and ridging across NM/west TX.
500 mb high pressure will remain the dominant weather feature over the BRO CWFA during the period. Meanwhile, while the aforementioned mid-level ridge will indeed be the dominant weather feature, model guidance suggests that a weak 500 mb low or inverted trough will briefly form over the southern half of the Lone Star State on Wednesday. NBM guidance really swung for the fences, suggesting numerous showers and thunderstorms over the lower Texas coastal waters.
1234 AM CDT Tue Sep 5 2023 (This evening through Tuesday) Mid-level satellite water vapor analysis shows the upper closed near northeast Oklahoma as it becomes absorbed into the upper trough swinging across the Northern Rockies today. Tonight, the lee trough will continue to push east over the Central Plains with the low level jet increasing. By tomorrow morning, the shallow cold front will move into the far southern Texas Panhandle.
With the dry air mass in place, overnight lows will be cooler than normal tonight and Tuesday night, with low 40s for the Flagstaff area and even dipping into the 30s for the usual cold spots such as Tusayan and Bellemont. As high pressure strengthens and shifts northward into New Mexico and southern Arizona from Wednesday onward, our breezy southwest winds of the past couple days will drop off a bit. However, as the ridge moves closer we will see afternoon highs become much warmer as well.
Otherwise, it is going to be warmer and drier this week as the ridge retrogrades westward toward the Desert Southwest/northern Baja.
141 AM MDT Tue Sep 5 2023 Water vapor shows upper low over northwest SD, with quasi-zonal flow covering much of the western CONUS. Radar returns show wrap around showers covering much of northeast WY, the northern Black Hills, and northwest SD, with relatively weak linear convection along the cold front across south central SD. Highs mostly in the 60s today, with a few locations in the lower 70s. Dry conditions along with a slow warming trend are expected mid to late week as a weak ridge slowly builds north across the western CONUS.
(Today and tonight) Yet another day of record heat for Lubbock is in the cards even as a decaying cold front slices through much of the region later this morning. Dewpoints east of this trough will only tick higher in the hours ahead with some upper 60s likely reaching the southern Rolling Plains shortly after sunrise. The cold front meanwhile should hang up in the Rolling Plains by midday and likely lead to a triple point along a mesolow in the Snyder vicinity later this afternoon. Elsewhere, the cooler air will lag the front as it often does, so Lubbock's record high of 102 may still be tied or broken despite light NE winds. Lows tonight will be cooler across the board on steady E-NE winds.
At the surface, high pressure remains the dominant weather feature east of the Mississippi River, with weak southerly low level flow over Central Alabama. Highs will be in the low to mid 90s.
The next batch of showers and storms will be associated with the main trough axis lifting through the region tomorrow afternoon. An upper level low pressure system will slowly lift from western Arkansas into southern Missouri tonight. Thunderstorms will continue in advance of this upper low.
229 AM MDT Tue Sep 5 2023 Satellite imagery early this morning shows the upper level low now along the WY/SD border. As the low moves east into the Dakotas this morning, these rain showers will gradually come to an end, generally by 6 to 9 AM. Outside of the smoke, today will be generally quiet and cool as a weak ridge builds in aloft. By Wednesday, warmer temperatures will return with highs in the mid 80s expected.
158 AM EDT Tue Sep 5 2023 High pressure brings mainly dry weather with hot afternoons through Wednesday. A cold front arrives late week with showers and even the chance for storms. Cooler for the weekend. A beautiful Labor Day is underway across the Central Appalachians as high pressure remains nestled nearby. Prevailing high pressure will promote dry weather both today into Tuesday coupled with above normal temperatures. Afternoon highs both today and tomorrow steer into the low 90s in most spots along the Ohio River Valley into the Charleston metro area and the West Virginia foothills. High pressure maintains dry weather and above normal temperatures into mid week, with afternoon highs on Wednesday expected to range from mid 70s in the higher elevations of the mountains to upper 80s/low 90s in the lowlands.
Upper ridging was noted early this morning over West Virginia and over northern Mexico. The upper trough that produced the localized very heavy rain near Lake Pontchartrain yesterday was centered from Missouri into Mississippi early this morning. Southeasterly onshore flow is producing isolated rain showers that are moving generally northward this morning, but echo tops are barely reaching the freezing level. The upper trough should be pulling away from the area this morning, and we can already see drying evident in the water vapor imagery across the area.
(Today and tonight) Low level jet bringing better low level moisture back to West Central Texas early this morning with dewpoint at Junction climbing into the lower 70s. Speaking of temperatures, with the upper ridge building a little more into place, temperatures look to climb another degree or two.
(Today and tonight) Quiet conditions will prevail through the near term as an upper level ridge overhead slowly breaks down. High temperatures will be in the low 90s.
500 AM EDT Tue Sep 5 2023 08Z sfc analysis shows high pressure over eastern parts of the state as low pressure is approaching from the northwest. This has also resulted in a small to moderate ridge to valley temperature split as readings range from the low 70s in the thermal belts to the mid 60s in the most sheltered spots. They all depict the eastern ridge further weakening today and tonight on account of the troughiness and mid level energy moving into the Ohio Valley from the west. This initial foray is bolstered by the end of the period, at mid week, by a better defined trough inbound from the Upper Midwest for Wednesday afternoon.
208 AM EDT Tue Sep 5 2023 A large ridge of high pressure across the Ohio Valley will build into the eastern Great Lakes by Tuesday, bringing dry weather and late season heat.
Current observations show the low pressure system and front roughly around Central Kansas. The low should slow slightly in its easterly progression while higher pressure moves in from the northwest today. Tomorrow, a fairly seasonable day is in store as the high pressure begins to move off to the east with the upper ridge trying to reamplify over the Rockies. High temperatures are forecasted to be in the low to mid 80's with winds shifting to out of the south/southeast. Tomorrow evening, mostly clear skies are expected along with warmer lows in the 50's.
This could briefly bring triple digit high temperatures back to Las Vegas with the lower deserts including Death Valley and the Colorado River Valley approaching 110 degrees. There could be a minor increase in mid and high clouds over the weekend as a few models are indicating some moisture being pulled into the area from a tropical cyclone over the eastern Pacific. The general outlook for the next couple of days is for dry conditions across the region with slightly warmer temperatures and afternoon breezes. Synoptically, the weather pattern has broad troughing off the west coast and high pressure centered over Chihuahua Mexico. Today, we are expecting generally quiet weather conditions with temperatures around 5 degrees warmer than yesterday but still below normal.
Now the main cooler air is well behind the wind shift and more tied to the 850 mb front and that is moving east as well and near a Hallock to just west of Grand Forks to Jamestown line. Winds behind this 850 mb increase from the north 20-30 mph and noticeably cooler air is present. 500 mb upper trough is moving slowly into western South Dakota and aloft there remains a south to north area of moisture that is maintaining clusters of showers and t-storms from Aberdeen SD area north to Jamestown to Devils Lake and into southern Manitoba.
This activity is expected to diminish from west to east as the low-level jet axis shifts eastward this morning. This feature is forecast to advance eastward throughout the day with the trough axis forecast to extend southward across the mid-Missouri River valley by 00z tonight. Ahead of this feature, a cold front extends from the eastern Dakotas into northeast Nebraska and south to central Kansas. Ahead and behind this boundary, strong mixing should push temperatures into the low to possibly mid 90s. A secondary cold front will bring stronger northwest winds into the region and we could see gusts to near 25 to 35 mph by late this afternoon into the early evening. Breezy winds and forecast dewpoints in the upper 50s will provide a much cooler and breezy evening for the region.
Otw, high amplitude upper ridge hanging on for one more day today. To the west we are starting to see some troughing and we actually have a few echoes on radar just west of the TN river at this time.
101 AM EDT Tue Sep 5 2023 High pressure will remain in control through most of Wednesday.
232 AM MDT Tue Sep 5 2023 West-northwest flow aloft will prevail today behind an upper level trough moving across the northern plains. Subsidence behind last evening's cold front brought drier conditions and gusty downslope winds overnight across parts of the Front Range. It will be cooler with highs in the mid to upper 70s across northeast Colorado. With less wind and continued dry airmass, temperatures should be cooler tonight with mid 40s to lower 50s across northeast Colorado. Dry light westerly flow aloft will continue across Colorado into this weekend on the north side of an upper level high.
153 AM PDT Tue Sep 5 2023 Warmer and drier weather this week with temperatures near to slightly below normal by mid-week. Weak trough lingers this week, though heights aloft will be gradually increasing. Highs across the Central Valley will warm back into the lower 90s, but heat risk will remain minor.
A cold front Wednesday will start temperatures trending downward for the end of the work week. A couple isolated showers continue across the lower Illinois River Valley towards Springfield, and this activity should remain isolated for the next hour or two before diminishing altogether. Once current convection ends, expect the remainder of the night to be dry with temps falling into the lower to mid 70s.
Onshore flow will continue for cooler than average contiions.
327 AM CDT Tue Sep 5 2023 Key Messages: * Cooler weather expected through the rest of the week and into the weekend behind this morning's cold front.
Predawn temps were in the lower and mid 70s. Highs today wl be mainly in the lower and mid 90s. As upper ridging conts to bld to the west of AR thru mid-week, the steering flow acrs AR wl turn NWly.
High pressure across the southeast US is producing E/SE flow across ECFL and the adjacent Atlantic waters this morning. Much like yesterday, a few higher (40-50) dBZ echoes are showing up, indicating that the lower levels continue to moisten. The Florida peninsula remains under a mid/upper level high pressure ridge extending across the eastern US. At the same time, an upper level short wave across the mid-lower MS Valley will continue to lift NE, as a large trough over the west Atlantic continues to deepen. At the surface, the high pressure ridge over FL will build south and westward through the day. Overnight lows will be in the low to mid 70s.
(Today through Wednesday night) The expected weak cold front is still on track to move in through the early morning hours of today as models project the upper-level trough to continue progressing east into the Great Plains. Current guidance expect temperatures to stick to the high 80s to mid 90s. Heading into the overnight and Wednesday, model agreement is still expecting high pressure to begin building back in with the 500mb center over Western Texas and Southeastern New Mexico. With the high pressure building back in, hot and dry conditions are expected to continue with afternoon temperatures returning low to mid 90s for tomorrow.
Upper ridge is starting to slowly shift east, as a deep upper wave pushes through the Rockies today. With this low now approaching us, we have opened up the gulf transport of moisture. Although, we are forecasting dewpoints in the low 70s for most. Fortunately, we will have quite a nice southwesterly breeze, which will help keep you "cooler. This wave is forecast to pass through Tuesday night, with a cold front dragging through the area overnight. Beyond Tuesday, guidance continues to break down the blocking pattern. After the ridge breaks down, we will fall under an active northwesterly flow pattern.
For this evening/tonight, an upper low will continue to move northeast across the Ozarks. Otherwise, the larger scale upper trof will continue to lift northeast from the Rockies across the northern Plains tonight thru Tuesday. The associated surface cold front will move across central Kansas toward dawn and be situated across southeast Kansas near peak heating on Tuesday.
At the surface, broad low pressure ahead of the upper level trough is spread out from the northern plains/southern Canada through the central plains, which is supporting gusty southerly/south-southwesterly winds across southwest KS. These downsloping winds along with fully clear skies have already resulted in temperatures rising into the low/mid 90s, and will peak in the low 100s later this afternoon. Northerly winds behind this boundary will cause temperatures to drop into the low to mid 60s for most areas early Tuesday, with only the far southeast zones holding in the upper 60s/low 70s given shorter residence time within cold advection.
Look for highs today to continue seasonably warm trend as of late, but generally be a few degrees cooler than those experienced yesterday, ranging upper 80s to lower 90s, mid 80s Cumberland Plateau Region. An unsettled quasi northwesterly flow pattern aloft will continue across our area as Wednesday progresses with eventual shifting of upper level troughing influences eastward. High temperatures on Wednesday may be a degree or so cooler than those experienced today per convective coverage, but will still be on the warm side ranging in upper 80s, mid 80s Cumberland Plateau Region.
1145 PM EDT Mon Sep 4 2023 VFR conditions will prevail as high pressure remains poised to the east and southeast.
The trough looks begin moving through late in the day on Wednesday. At the surface, high pressure will generally remain in control of the sensible weather. The high center should begin to shift offshore late Wednesday ahead of an approaching weak front. If the upper trough has a bit more forcing with it or the front approaches sooner than anticipated, precip may start earlier in the NW corner late Wednesday afternoon.
(Now through Wednesday) An upper trof near the lower/mid Mississippi River valley weakens while advancing into the eastern states and becomes partially absorbed into a Plains upper trof which approaches the Great Lakes region. Highs today will be mostly in the lower 90s, then Wednesday will be a bit warmer with some locations reaching the mid 90s.
204 AM MDT Tue Sep 5 2023 Weak ridging builds over the Treasure State as the Pacific low exits eastward. Warmer and drier conditions develop today, lasting through the rest of the week. Weak ridging propagates over the Treasure State in its wake, resulting in things settling down quite significantly for the remainder of the week.
The 500 mb trough axis will move east of the Mississippi River by 18z, which will result in decreasing rain chances for se Missouri this afternoon.
149 AM EDT Tue Sep 5 2023 (This afternoon through Tuesday) Models depict high pressure remaining well established across the region during the short term with relatively dry air keeping dew points in the upper 60s to low 70s. However, the lower dew points are going to help in moderating heat index values, which are expected to remain in the low to mid 90s.
The threat for severe weather today is overall low as instability values are greatly diminished, and perhaps not high enough to compete with the high amounts of shear still in place. Breezy to perhaps windy northwest winds may be found today behind the mentioned cold front. Lows tonight will be cooler than normal, with many areas in the 40s. A fairly quiet zonal flow to weak ridging pattern sets up for the remainder of the work week.
A better chance for showers and thunderstorms will develop through the day on Wednesday as an upper level low pressure system moves through the region. Mid and upper level ridging will break down as it shifts off to the east today. This is ahead of a mid level short wave that will move into the lower Ohio Valley through this afternoon. Meanwhile, a broader mid level trough will move across the Great Lakes later tonight and into the day on Wednesday.
348 AM EDT Tue Sep 5 2023 High pressure will remain over the area through Wednesday with mainly dry and hot conditions. Unsettled weather returns by the end of the week, along with cooler conditions by the weekend. 325 AM Update: A strong ridge overhead will bring very warm conditions to the area today again. With the ridge a bit more amplified compared to yesterday, temperatures and dew points will be a degree or two higher, along with plenty of sunshine. These advisories are mainly for the urban/valley locations, but very warm and humid conditions will be present at the higher elevations as well. Low temperatures will be above normal for this time of the year, but will actually be on the cooler side considering the heat during the day.
336 AM CDT Tue Sep 5 2023 Key Points: - Another warm day today before cooler air moves in Wednesday. Ascent and moisture advection due to a strong low-level jet and a surging cold front moving into the area are producing some showers and thunderstorms this morning. Winds ahead of the trough should remain gusty as they slowly veer to the west. Areas further north and west should see slightly lower temperatures as the surface boundary will move through earlier in the morning, advecting in cooler and drier air.
06Z observations show a large upper level trough extending from the Canadian border through central Colorado and a departing upper low in central Missouri. At the surface a fast moving cold front extends from Hays to Elkhart with gusty winds mixing down to the surface out of the northwest around 15-35 mph. With the cold air advection throughout the day temperatures should be much cooler with highs in the upper 80s to lower 90s. Wednesday should be another relatively cool day with winds gradually switching to the south as the high departs to the east.
The stronger winds are expected Tuesday behind the cold front where peak wind gusts will be near 30 mph. On the south side of that closed low, it has initiated a line of thunderstorms in southern Missouri. On the north side of the low, it has led to weak showers which may not even be reaching the surface as the low levels are very dry. Winds will maintain some strength ahead of a cold front that will begin to move into the forecast area very late this evening. In addition to the frontal passage, the low level jet will increase to about 40 to 50 knots late this evening and maintain it's strength until the frontal passage.
Given the drier air mass and high pressure, no rain is expected.
Temperatures range from mid 70s in our west to mid 90s across our east, with dew points in the 50s for most to the lower 60s near the northern/northeastern foothills. Given deep, dry boundary layers over much of the area--which will support strong, merging outflow boundaries--and increasing midlevel flow as the aforementioned trof approaches, damaging straight-line winds will be the primary threat. Much milder 850 mb temps arrive late tonight behind an attendant cold front, which should support below average temps tomorrow. Much drier 500 mb to tropopause air arrives late tomorrow into Wednesday as ridging begins to build from the Desert Southwest northward into the Rockies.
The cloud cover will help temperatures be a few degrees cooler than yesterday. Tonight the main upper level trough will move into the area with positive vorticity advection, 850 to 700 mb warm air advection, and the low level jet. The upper level trough will linger over the area with the surface front moving through later on Wednesday.
Continued hot with small chances of showers and storms this High Impact Weather Potential. Small chances of non-severe Large area of high pressure remains centered across the Eastern US. a complex area of low pressure continues to develop from Western Ontario thru the Northern and Central Plains. A surface cold front will slice across the region later Wednesday into early Wednesday night. However, a majority of guidance develops showers and embedded thunderstorms across the area during the afternoon and evening out ahead of the cold front.
- Isolated showers and thunderstorms possible over the Victoria Crossroads and over the waters today and Wednesday The high pressure ridge anchored over West Texas and northern Mexico will continue to spread to the east today and Wednesday, resulting in hot temperatures again.
The low pressure system responsible for our recent wet and cool weather pattern (sorry Labor Day weekend campers!) has departed, and today we transition into a WSW flow that will support a warming/drying trend into the week.
A upper level trough will deepen west of the area tonight and lift northeast into Tuesday. The chances for thunderstorms diminish through the day as a pre frontal trough moves in and then the main cold front follows. Looking at the expected instability, most of it is focused along and ahead of the pre frontal trough which is mostly west of the area by about 18z.
923 PM PDT Mon Sep 4 2023 Low pressure covering the West this Labor Day, will give way to building high pressure over the Southwest this week.
A cold front will approach from the northwest late Tuesday, and should be able to focus additional activity across mainly northern sections of the forecast area.
(Through Tonight) High pressure will be over the area through Tonight.
Some relief from the heat will be possible today behind the front in at least NW parts of the fa where highs in the low to mid 90s will be possible.
455 AM EDT Tue Sep 5 2023 08Z sfc analysis shows high pressure over eastern parts of the state as low pressure is approaching from the northwest. This has also resulted in a small to moderate ridge to valley temperature split as readings range from the low 70s in the thermal belts to the mid 60s in the most sheltered spots. They all depict the eastern ridge further weakening today and tonight on account of the troughiness and mid level energy moving into the Ohio Valley from the west. This initial foray is bolstered by the end of the period, at mid week, by a better defined trough inbound from the Upper Midwest for Wednesday afternoon.
355 AM EDT Tue Sep 5 2023 High pressure will remain in control through most of Wednesday.