Aikyam-Lab/Synoptic-Bench huggingface dataset:
WHAT WE CAN SAY IS EACH TROUGH OF LOW PRESSURE WILL BE PROGRESSIVE AND NOT ALLOW A LOT OF TIME FOR LARGE AMOUNTS OF PRECIPITATION. TULAROSA VALLEY AND THE LOWER RIO GRANDE VALLEY FROM SOCORRO SOUTH.
Cold front sitting northwest of the forecast area will continue its approach, moving through at least the northwestern half to two-thirds by morning. Compact short wave trough over south central KS/north central OK at this time will translate across nern OK/nwrn AR tonight. A compact upper low spinning across western KS will drop southeast across the region overnight. Reinforcing high pressure behind the system will bring slightly cooler air for the few days however.
941 PM EST SAT JAN 2 2016 LOW PRESSURE WILL SLOWLY MOVE EAST THROUGH SOUTHERN QUEBEC TONIGHT THROUGH SUNDAY AND WILL DRIVE A COLD FRONT THROUGH THE REGION LATE IN THE DAY.
Based on the latest radar trends, have increased PoPs for the first half of tonight and expanded the higher PoPs slightly further north for the second half of tonight.
458 PM CST SAT JAN 2 2016 TEMPERATURES ARE THE MAIN FORECAST CHALLENGE THROUGH SUNDAY AS THE BATTLE BETWEEN THE PERSISTENT SNOW PACK AND UPPER RIDGE CONTINUES ACROSS THE FORECAST AREA. A 500HPA TROUGH DIGS OVER THE GREAT LAKES AS A 250HPA JET STREAK MOVES SOUTH OVER THE UPPER MISSISSIPPI VALLEY. THINKING THE BACK DOOR COLD FRONT WILL HOLD EAST OF THE AREA FOR THIS FORECAST PERIOD.
HIGH PRESSURE (1030 MILLIBARS) WAS BUILDING EASTWARD INTO OUR REGION FROM TEXAS. LOWS IN COASTAL NORTHEAST AND NORTH CENTRAL FL WILL FALL INTO THE LOWER 50S. WITH HIGHS IN THE LOW TO MID 50S. RAINFALL WILL OVERSPREAD THE FLORIDA COASTAL WATERS DURING THE OVERNIGHT AND PREDAWN HOURS AS LOW PRESSURE DEVELOPS EAST OF THE FLORIDA PENINSULA.
638 PM MST SAT JAN 2 2016 BENIGN WEATHER THROUGH THE SHORT TERM AS HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER. LIGHT WINDS WITH RIDGE OF HIGH PRESSURE OVERHEAD THROUGH SUNDAY AFTERNOON.
/ISSUED 228 PM EST SAT JAN 2 2016/ HIGH PRESSURE HAS SETTLED DEEP INTO THE HEART OF TEXAS WITH A DRY NORTHERLY FLOW THE RESULT OVER THE LOCAL AREA. LOW PRESSURE FORMING OFF THE FLORIDA COAST SHOULD JUST REINFORCE DRY LOW LEVEL FLOW WHILE INCREASE IN MID CLOUDS ARE NOT ANTICIPATED TO RESULT IN ANY ADDITIONAL RAINFALL FOR THE LOCAL AREA.
535 PM CST SAT JAN 2 2016 Forecast area remains cloud-free this afternoon, and winds have already switched back to the southwest behind the earlier trough passage. Next trough/front is seen on afternoon surface map from near Duluth southwest into north central Kansas. Temperatures expected to fall into the 20-25 degree range, with some locally cooler conditions over the remaining snow cover. The surace trof should push out of our area on Sunday with Canadian high pressure building southeast into our area.
DRY AIR IN THE LOW LEVELS SHOULD KEEP RAINFALL TOTALS MUCH LIGHTER IN THE UTS AREA NORTHEASTWARD. SOUTHWESTERLY FLOW ATOP THE LOWER LEVEL WEAK NORTH(EAST)ERLY FLOW DEFINING THE ISENTROPIC UPGLIDE PATTERN THAT HAS KEPT EITHER PERIODIC SOUTHERN FORECAST AREA LIGHT RAIN OR DRIZZLE AROUND THESE PAST FEW DAYS. OR UNTIL THE SHALLOW UPPER TROUGH AXIS NOW ADVANCING EAST INTO NORTHERN MEXICO IS EAST OF THE REGION. SUNDAY WILL AGAIN BE COLD WITH ANOTHER SHOT OF COOLER AND DRIER AIR DESCENDING UPON EASTERN TEXAS LATE TOMORROW. CLEARING OVERCAST FROM WEST TO EAST ALONG THE BACKSIDE OF THE EXITING MAXIMUM TEMPS TOMORROW WILL BE IN THE RELATIVELY WARMER MIDDLE 50S BUT STILL BELOW BY EARLY JANUARY'S STANDARDS.
642 PM EST SAT JAN 2 2016 LOW PRESSURE WILL SLOWLY MOVE EAST THROUGH SOUTHERN QUEBEC TONIGHT THROUGH SUNDAY AND WILL DRIVE A COLD FRONT THROUGH THE REGION LATE IN THE DAY.
MID AND UPPER LEVEL MOISTURE INCOMING FROM THE SOUTHWEST AHEAD OF AN ASSOCIATED TROF WILL BRING A FEW SPRINKLES OR LIGHT SHOWERS TO OUR SOUTHERN TERMINALS OVERNIGHT. DRIER AIR IN THE LOW LEVELS WILL RESULT IN PREVAILING VFR. SKIES WILL CLEAR TOWARD MIDDAY SUNDAY AS DRIER AIR ADVANCES INTO THE REGION WITH PASSAGE OF THE AFOREMENTIONED TROF. TONIGHT WILL SEE TEMPS A BIT COOLER THAN LAST NIGHT AS DEW POINTS ARE A BIT COOLER AND THIS SHOULD ALLOW TEMPS TO FALL A BIT MORE.
AN INTENSE UPPER CYCLONE IS CENTERED OVER FAR NORTHERN QUEBEC & IS THE MORE DOMINANT OF THE 2 CHARACTERS. THE WLY WINDS ARE COMBINING WITH SUNNY SKIES TO BOOST TEMPERATURES INTO THE LOWER & MID 40S. ALL WILL REMAIN QUIET ACROSS THE NEIGHBORHOOD AS THE PERSISTENT NW MID-UPPER FLOW DRIVES MASSIVE(!) HIGH PRESSURE SLOWLY SE FROM THE NORTHERN & CENTRAL ROCKIES. WITH THE W/NW SFC FLOW SLOWLY SHIFTING TO THE N THEN NE COOLER/COLDER WEATHER IS CERTAIN FOR ALL AREAS. A SHARP UPPER-DECK TROF THAT IS SCHEDULED TO REACH THE W COAST TUE EVENING WILL PUSH E ACROSS THE GREAT BASIN ON WED AT WHICH TIME IT BEGINS TO SHEAR. LIGHT WEST-SOUTHWEST WINDS AHEAD OF THE TROUGH PASSAGE.
834 PM MST SAT JAN 2 2016 HIGH CLOUD COVER MOVING OVER THE MOUNTAINS AND HELPED TO LIMIT THE COOLING IN THE HIGH VALLEYS THIS EVENING. HIGH PRESSURE RIDGE ALOFT WILL BE OVER COLORADO THROUGH SUNDAY.
THERE HAVE BEEN A FEW MORE BREAKS IN THE HIGHER CLOUD STREAM THAN YESTERDAY. THIS CLOUD STREAM ASSOCIATED WITH THE ACTIVE SOUTHERN BRANCH OF THE JET STREAM SHOWS SIGNS OF HAVING AN END OVER OUR REGION WITHIN 24 HOURS AS A DISTURBANCE EMBEDDED IN THE SOUTHERN JET STREAM TRANSITIONS ACROSS THE LOWER MS VALLEY. ALTHOUGH A FEW LIGHT SHOWERS OR SPRINKLES CANNOT BE RULED OUT ALONG AND SOUTH OF THE HIGHWAY 84 CORRIDOR. ALTHOUGH WELL NORTH OF I-20 SOME SPLOTCHES OF RADIATIONAL COOLING MAY ALLOW READINGS TO BRIEFLY DIP DOWN INTO THE LOW TO MID 30S.
738 PM EST SAT JAN 2 2016 AN UPPER LEVEL DISTURBANCE AND COLD FRONT WILL DROP INTO THE AREA LATE TONIGHT INTO SUNDAY MORNING BRINGING A CHANCE OF SNOW SHOWERS.
SOUTHWESTERLY FLOW ATOP THE LOWER LEVEL WEAK NORTH(EAST)ERLY FLOW DEFINING THE ISENTROPIC UPGLIDE PATTERN THAT HAS KEPT EITHER PERIODIC SOUTHERN FORECAST AREA LIGHT RAIN OR DRIZZLE AROUND THESE PAST FEW DAYS. OR UNTIL THE SHALLOW UPPER TROUGH AXIS NOW ADVANCING EAST INTO NORTHERN MEXICO IS EAST OF THE REGION. SUNDAY WILL AGAIN BE COLD WITH ANOTHER SHOT OF COOLER AND DRIER AIR DESCENDING UPON EASTERN TEXAS LATE TOMORROW. CLEARING OVERCAST FROM WEST TO EAST ALONG THE BACKSIDE OF THE EXITING MAXIMUM TEMPS TOMORROW WILL BE IN THE RELATIVELY WARMER MIDDLE 50S BUT STILL BELOW BY EARLY JANUARY'S STANDARDS.
WV Imagery indicates a building upper level ridge of high pressure shifting slowly east across the Central and Southern Rockies. Near the surface, a broad area of high pressure remains situated across the Northern Rockies. Light west to northwest winds are expected tonight in advance of a weak cold front. In this dry airmass, temperatures will easily fall into the lower to mid 20s. Given the lack of strong cold advection and abundant sunshine, highs Sunday should still range from the lower 40s in central Kansas to the mid to upper 40s in far southwestern Kansas. The coolest night will be Sunday night as the aforementioned area of high pressure settles across the plains, along with light winds and dry air. Weak lee troughing and southerly flow will allow for some moisture return and milder overnight lows by mid-week.
637 PM EST SAT JAN 2 2016 A COLD FRONT, WITH THE COLDEST AIRMASS OF THE WINTER SEASON, WILL CROSS THE AREA SUNDAY AFTERNOON AND EVENING.
SFC ANALYSIS THIS EVE SHOWS COLD FRONT DRAPED ACROSS SOUTH FL WITH MULTI-LAYERED CLOUDS NORTH OF THE BOUNDARY. NORTHERLY WINDS AROUND 10-15 KNOTS EXPECTED INTO THIS EVENING BEFORE MODELS SHOW A WEAK WAVE/LOW PRESSURE DEVELOPING EAST OF THE COASTAL WATERS AND ALONG STALLED BOUNDARY SOUTH OF THE AREA.
MID AND UPPER LEVEL MOISTURE INCOMING FROM THE SOUTHWEST AHEAD OF AN ASSOCIATED TROF WILL BRING A FEW SPRINKLES OR LIGHT SHOWERS TO ALL TERMINALS OVERNIGHT. DRIER AIR IN THE LOW LEVELS WILL RESULT IN PREVAILING VFR. SKIES WILL CLEAR TOWARD MIDDAY SUNDAY AS DRIER AIR ADVANCES INTO THE REGION WITH PASSAGE OF THE AFOREMENTIONED TROF. TONIGHT WILL SEE TEMPS A BIT COOLER THAN LAST NIGHT AS DEW POINTS ARE A BIT COOLER AND THIS SHOULD ALLOW TEMPS TO FALL A BIT MORE.
AND A WEAK COLD FRONT WILL PUSH SOUTH THROUGH THE AREA IN THE WAKE OF THE TWO FEATURES.
LATEST HRRR TIME ENSEMBLE GUIDANCE SUGGESTS A GREATER LIKELIHOOD FOR MEASURABLE RAIN SOUTH OF THE HIGHWAY 84 CORRIDOR DURING THE EARLY MORNING HOURS. THERE HAVE BEEN A FEW MORE BREAKS IN THE HIGHER CLOUD STREAM THAN YESTERDAY. THIS CLOUD STREAM ASSOCIATED WITH THE ACTIVE SOUTHERN BRANCH OF THE JET STREAM SHOWS SIGNS OF HAVING AN END OVER OUR REGION WITHIN 24 HOURS AS A DISTURBANCE EMBEDDED IN THE SOUTHERN JET STREAM TRANSITIONS ACROSS THE LOWER MS VALLEY. ALTHOUGH A FEW LIGHT SHOWERS OR SPRINKLES CANNOT BE RULED OUT ALONG AND SOUTH OF THE HIGHWAY 84 CORRIDOR. ALTHOUGH WELL NORTH OF I-20 SOME SPLOTCHES OF RADIATIONAL COOLING MAY ALLOW READINGS TO BRIEFLY DIP DOWN INTO THE LOW TO MID 30S.
VFR CIGS ARE AROUND 6-7KFT AT THE LOWEST WITH MOST BEING MIDDECK AND CIRRUS THIS CYCLE. AN UPPER LOW OVER S KN/N OK AND ONE OVER THE RIO GRANDE WILL BOTH MOVE E BRINGING SKC EARLY ON SUNDAY. /ISSUED 224 PM CST SAT JAN 2 2016/ CLOUDS TO PERSIST ACROSS THE REGION THROUGH THE OVERNIGHT HOURS WITH TEMPERATURES FORECAST TO FALL INTO THE LOW TO MID 30S AREAWIDE. AN UPPER-LOW TO PUSH SOUTHEAST ACROSS ARKANSAS OVERNIGHT INTO SUNDAY WITH UPPER-LEVEL RIDGE FORECAST TO REBUILD BEHIND IT. A FAIRLY STABLE WEATHER PATTERN TO PERSIST FROM SUNDAY THROUGH THE MIDDLE OF THE WORK WEEK WITH TEMPERATURES RANGING FROM HIGHS IN THE UPPER 40S TO LOWS NEAR FREEZING.
TEMPS ARE ALSO STEADY UNDER THE LOW CLOUDS ALONG AND EAST OF THE VALLEY. WE WILL RAISE OVERNIGHT LOWS UNDER THE CLOUD DECK INTO THE LOW 20S. CLOUDS ASSOCIATED WITH WAVE/BACK DOOR COLD FRONT WILL COVER ROUGHLY THE THE NE HALF OF THE FA BY MORNING. WITH COLUMN COOLER TEMPERATURES NOT AS MILD AS TODAY BUT STILL ABOVE AVERAGE.
AT THE SURFACE AND IN THE LOWER TO MIDDLE LEVELS. LATEST AVAILABLE LAND AND MARINE SURFACE ANALYSIS AND OBSERVATIONS AS OF 900 PM DETAIL A 1030 MB ANTICYCLONIC RIDGE OVER THE LONE STAR STATE. A SURFACE COLD FRONT HAS MANAGED TO CREEP INTO SOUTH FLORIDA AND IS ANALYZED FROM NAPLES TO PALM BEACH COUNTY. A RARE JANUARY CLOUDLINE WAS IN PLACE NEAR THE LOWER FLORIDA KEYS. ALLOWING FOR BRIEF MODERATE SHOWERS WITH DUAL POL 1 HOUR RAINFALL ESTIMATES OF A TENTH INCH OR LESS OCCURRING OVER PORTIONS OF THE LOWER FLORIDA KEYS. TEMPERATURES ACROSS THE ISLANDS ARE PRESENTLY IN THE LOWER TO MID 70S WITH NEARLY SIMILAR DEWPOINTS. SO THE ACTUAL SURFACE COLD FRONT WILL REMAIN TO OUR NORTH. A COLD FRONT IS FORECAST TO REACH THE KEYS SUNDAY NIGHT AND ACTIVE WEATHER CAN POSSIBLY AFFECT THE TERMINALS AFTER 03/18Z.
Compact short wave trough over south central KS/north central OK at this time will translate across nern OK/nwrn AR tonight. A compact upper low spinning across western KS will drop southeast across the region overnight. Reinforcing high pressure behind the system will bring slightly cooler air for the few days however.
ANOTHER QUIET NIGHT EXPECTED ACROSS THE MID STATE WITH HIGH PRESSURE SETTLING IN OVER THE AREA. WITH LOWS IN THE LOW 20S POSSIBLE FOR THOSE AREAS.
436 PM MST SAT JAN 2 2016 17Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED COMPACT SHORT WAVE TROUGH MOVING SOUTH ALONG PERIPHERY OF LARGER RIDGE AXIS STRETCHING FROM SOUTHERN COLORADO TO MONTANA. DESPITE THE AFOREMENTIONED TROUGH. WITH H5 RIDGE BUILDING THROUGH THE AREA. WHILE LATEST DATA SUGGEST TEMPS A FEW DEGREES WARMER OR SIMILAR TO LAST NIGHT. HIGHS ON SUNDAY WILL BE COOLER THAN TODAY. ESPECIALLY IN THE EAST WHERE COOLER AIR WILL BACK IN FROM THE EAST AND AN INCREASING CIRRUS DECK WILL LIMIT FULL SURFACE HEATING.
952 PM EST SAT JAN 2 2016 THE NEAR TERM SECTION HAS BEEN UPDATED BELOW QUIET WEATHER IS EXPECTED FOR THE REST OF THE WEEKEND AS INDIANA REMAINS CAUGHT BETWEEN LOW PRESSURE OVER CANADA AND HIGH PRESSURE OVER THE SOUTHERN PLAINS. A COLD FRONT IS EXPECTED TO PUSH TOWARD INDIANA ON SUNDAY AND ACROSS THE STATE ON SUNDAY NIGHT. COOLER AIR IS EXPECTED TO ARRIVE IN THE AREA IN THE WAKE OF THE FRONT ALONG WITH HIGH PRESSURE AS THE WORK WEEK BEGINS. CURRENT TEMPS ACROSS THE AREA ARE GENERALLY IN THE LOW 30S. SOME HINTS TOWARD THE ARRIVAL OF LOWER LEVEL CLOUDS ARE PRESENT AS THE COLD FRONT APPROACHES AND 925MB RH POINT TOWARD SATURATION. GFS AND NAM BOTH SUGGEST A COLD FRONT SWEEPING ACROSS INDIANA ON SUNDAY AS LOWER LEVEL FLOW BECOMES NORTHWESTERLY.
Compact upper low continues to drop southeastward over western Kansas, the main impacts of which have been to boost highs a bit with better mixing, and to drop dewpoints as you go west and mix into the drier air. High pressure at the surface continues to drop southward from the high Northern Plains into the Central Plains tonight and into Sunday. As the front comes in, think lows across the far southeastern counties will hold in the lower 20s while the northern counties drop into the teens. Cold advection continues tomorrow but in combination with mostly clear skies still think highs should make it into the lower/middle 30s tomorrow afternoon.
17Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED COMPACT SHORT WAVE TROUGH MOVING SOUTH ALONG PERIPHERY OF LARGER RIDGE AXIS STRETCHING FROM SOUTHERN COLORADO TO MONTANA. DESPITE THE AFOREMENTIONED TROUGH. WITH H5 RIDGE BUILDING THROUGH THE AREA. WHILE LATEST DATA SUGGEST TEMPS A FEW DEGREES WARMER OR SIMILAR TO LAST NIGHT. HIGHS ON SUNDAY WILL BE COOLER THAN TODAY. ESPECIALLY IN THE EAST WHERE COOLER AIR WILL BACK IN FROM THE EAST AND AN INCREASING CIRRUS DECK WILL LIMIT FULL SURFACE HEATING.
529 PM CST SAT JAN 2 2016 FOR 00Z TAFS /ISSUED 153 PM CST SAT JAN 2 2016/ NOT A BAD JANUARY DAY WITH TEMPS ACROSS THE CWA IN THE LOW/MID 40S WITH LIGHT WINDS. OTHERWISE MODEL SOUNDINGS AND TIME SECTIONS SHOW VERY DRY CONDITIONS IN THE LOWER LAYERS OF THE ATMOSPHERE TONIGHT.
THE REGION IS BETWEEN A LARGE AREA OF SUBSIDENCE UNDER THE LARGE HIGH PRESSURE RIDGE AXIS. TEMPS ARE SLIGHTLY COOLER THAN PREVIOUS TRENDING.
544 PM CST SAT JAN 2 2016 HIGH PRESSURE CONTINUES OVER THE AREA TODAY.
THIS AND THE ARRIVAL OF A WEAK COLD FRONT LATE TONIGHT SHOULD ALLOW TEMPERATURES TO FALL MORE RAPIDLY AS WE MOVE INTO THE OVERNIGHT HOURS. SO WE WILL KEEP THE LOW TEMPS AS IS. AND A WEAK COLD FRONT WILL PUSH SOUTH THROUGH THE AREA IN THE WAKE OF THE TWO FEATURES.
600 PM CST SAT JAN 2 2016 A COLD FRONT. MAINLY FOR THE HIGHER TERRAIN FROM DULUTH AND ALONG THE NORTH SHORE. THE LOW LEVEL CONVECTIVE LAYER OVER THE LAKE WILL CLIMB TO ABOUT 3500 FEET DEEP OVERNIGHT. THE PERIOD OF LIGHT SNOWFALL RATES COULD ADD UP TO A FEW INCHES OF SNOW IN THE HIGHER TERRAIN OF IRON COUNTY. THE LOWS SHOULD RANGE FROM THE MIDDLE TO UPPER TEENS. SFC AND UPPER RIDGING MOVE ACROSS THE REST OF THE FORECAST AREA SUNDAY NIGHT.
THE HIGH WIND WARNING WILL BE CONTINUED. THEN GRADUALLY DIMINISH AS A COLD FRONT MOVES SOUTHWARD INTO THE REGION. A GENERALLY DRY COLD FRONT WILL BEGIN TO CROSS THE INTERNATIONAL BORDER AFTER MIDNIGHT AND PUSH SLOWLY SOUTH. WINDS BEHIND THE FRONT WILL SHIFT TO THE NORTH-NORTHWEST AND COOLER AIR WILL MOVE IN BEHIND THE FRONT.
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER DURING THIS PERIOD. RIDGING ALOFT AND AT THE SFC WILL HOLD CONTROL OF THE WEATHER THROUGH THE PERIOD. A WEAK COLD FRONT WILL DRIFT INTO NRN LOWER LATE TUE NIGHT. LATEST OPERATIONAL AND ENSEMBLE RUNS OF THE ECMWF AND GFS SHOW RIDGING BOTH AT THE SURFACE AND ALOFT THROUGH THE ENTIRE PERIOD. IF THERE IS GOING TO BE ANY ISSUE WITH THE DRY AND MAINLY CLEAR FORECAST IT WILL COME FROM THE HANDLING OF THE LOW SOUTHWEST OF THE SOUTHERN CALIFORNIA COAST AND THE POTENTIAL TROPICAL SYSTEM OFF THE BAJA OF CALIFORNIA. THE SYSTEM IS ABSORBED BY THE RIDGE IN THE MODELS WITH DIFFERENT TIMING AND LOCATION.
346 AM EDT MON SEP 21 2015 HIGH PRESSURE WILL DOMINATE THROUGH THE WEEK AND INTO THE WEEKEND BRINGING FAIRLY SEASONABLE AND DRY FALL WEATHER. WITH SLIGHTLY COOLER READINGS IN THE UPPER 60S ACROSS THE HIGHER TERRAIN. THIS LIGHT DOWNSLOPE FLOW WILL KEEP TEMPERATURES A FEW DEGREES WARMER THAN LAST NIGHT WITH READINGS GENERALLY IN THE MID TO UPPER 40S.
A COLD FRONT WAS LOCATED FROM APPROXIMATELY NORWAY HOUSE AIRPORT MANITOBA/CYNE. AND INTO LETHBRIDGE AIRPORT ALBERTA/CYQL. A DRY COLD FRONTAL PASSAGE REMAINS ON TRACK FOR WESTERN AND CENTRAL NORTH DAKOTA TODAY.
Temperatures today will be a real challenge, and with all this moisture in place along with a slow erosion of the expected fog/low stratus, we will probably only see temperatures topping out in the lower to mid 80s northeast of a Dighton to Dodge City to Coldwater line.
OTHERWISE THE WEEK WILL BE DOMINATED BY HIGH PRESSURE AND MODERATING TEMPERATURES. THE NEAR TERM WILL BE DOMINATED BY AN AMPLIFYING UPPER TROUGH MOVING INTO THE OHIO VALLEY.
139 AM EDT MON SEP 21 2015 WEAK SFC/LOW LEVEL TROUGH CONTINUES TO LINGER OVER SOUTH FLORIDA WITH A FEW SMALL SHOWERS ALONG THE EAST COAST PROBABLY LASTING MOST OF THE OVERNIGHT AND INTO THE MORNING HOURS.
1206 AM CDT MON SEP 21 2015 FOR 06Z TAFS /ISSUED 930 PM CDT SUN SEP 20 2015/ MID-LEVEL LONGWAVE TROUGH CURRENTLY SITUATED FROM THE WESTERN GREAT LAKES INTO THE SABINE VALLEY REGION OF EAST TEXAS IS PROGGED TO SHIFT SLOWLY EASTWARD OVERNIGHT. MID/HIGH-LEVEL CLOUD COVER WILL CONTINUE TO INCREASE THROUGHOUT THE NIGHT AS THE TROUGH AXIS APPROACHES -- AND THIS WILL LIKELY KEEP MINIMUM TEMPERATURES A FEW DEGREES ABOVE MOS GUIDANCE VALUES AS INDICATED IN THE CURRENT FORECAST. UPPER-LVL TROUGH AXIS TO THE WEST OF THE REGION WILL CONTINUE TO PUSH SLOWLY EWD OVERNIGHT. POCKETS OF LGT RAIN DEVELOPING EAST OF UPPER TROUGH CONTINUE TO APPROACH THE AREA FROM NRN MISSISSIPPI. AS TROUGH AXIS SHIFTS TO THE SE.
AN UPPER LEVEL LOW PASSING TO THE SOUTH WILL INTRODUCE THE CHANCE OF SHOWERS AND THUNDERSTORMS FOR PARTS OF LOS ANGELES COUNTY MONDAY INTO TUESDAY. SOUTHWESTERLY FLOW ALOFT CONTINUES TO DEVELOP BETWEEN A RIDGE OF HIGH PRESSURE ALOFT OVER THE DESERT SOUTHWEST AND A TROUGH OF LOW PRESSURE ABOUT 350 MILES SOUTH-SOUTHWEST OF LOS ANGELES. AND THE TROUGH OF LOW PRESSURE TO THE SOUTH-SOUTHWEST OF LOS ANGELES. WITH THE TROUGHS LOCATION. THERE IS SOME UNCERTAINTY WITH THE FORECAST AS THE MODEL SOLUTIONS DO NOT HANDLE TROUGHS TO THE SOUTHWEST VERY WELL. THIS INCLUDES SOME OF THE HIGHER RESOLUTION MODELS.
544 AM EDT MON SEP 21 2015 AN APPROACHING COLD FRONT WILL SLOWLY SINK SOUTHWARD AND THROUGH THE AREA TODAY AND TONIGHT. LEANED TOWARD THE HIGHER GUIDANCE TEMPERATURES IN THE SOUTH PART JUST AHEAD OF THE FRONT. WHILE COOLER READINGS FOUND ACROSS THE NORTH BEHIND THE FRONTAL ZONE. MODELS SHOW AN UPPER TROUGH DRAPED ACROSS THE APPALACHIANS TONIGHT WITH THE FRONTAL BOUNDARY SLOWLY SLIPPING SOUTH OF THE FORECAST AREA. A WEAK UPPER LOW WILL REMAIN ACROSS THE SOUTHEASTERN STATES THROUGH THE WORK WEEK AND WILL SLOWLY RETROGRADE WESTWARD BY THE WEEKEND.
222 AM PDT MON SEP 21 2015 VERY WARM TEMPERATURES CONTINUE THROUGH TODAY AS HIGH PRESSURE PERSISTS. VERY WARM RIDGE IN PLACE OVER CENTRAL CALIFORNIA AGAIN TODAY, SO ANOTHER HOT DAY IS ON TAP. BOTH WATER VAPOR AND INFRARED IMAGERY SHOW QUITE A BIT OF CONVECTION WITH THIS LOW AND THIS MUCH BE WATCHED CAREFULLY. FORECAST MODELS APPEAR TO BE TOO DRY WITH THE LOW AS IT IS PROGGED TO MOVE NORTHEAST ACROSS MAINLY SOUTHERN CALIFORNIA TONIGHT AND TUESDAY. BY LATER TUESDAY, THE LOW IS PROJECTED TO QUICKLY GET CAUGHT UP IN THE INCREASING WESTERLY FLOW INTO CALIFORNIA AND A QUICK DRYING WILL OCCUR.
539 AM CDT MON SEP 21 2015 UPPER TROUGH AXIS WAS LOCATED JUST UPSTREAM THIS MORNING. HIGH PRESSURE INFLUENCES AND UPPER LEVEL RIDGING INFLUENCES BUILDING IN FROM THE MS RIVER VALLEY WILL BE THE MAIN WX PLAYERS ACROSS THE MID STATE THRU WED NIGHT. AS UPPER LEVEL TROUGHING INFLUENCES MOVE EWD AND ABOVE MENTIONED UPPER LEVEL RIDGING INFLUENCES BUILD ACROSS THE AREA. MAINLY IN THE LOW TO MID 50S. THE ORIENTATION OF THE UPPER RIDGE AXIS LOOKS A BIT UNORTHODOX AS IT STRETCHES FROM THE DESERT SOUTHWEST NORTHEASTWARD AND THE SOUTHEAST ACROSS THE MID ATLANTIC. THE GFS SOLUTIONS SHOWS A GENTLE RETROGRADE MOTION IN REGARD TO WEAK UPPER LEVEL TROUGHING OVER THE SOUTHEASTERN U.
359 AM CDT MON SEP 21 2015 WARM AIR WILL SURGE NORTHWARD ACROSS THE REGION TODAY AHEAD OF AN APPROACHING COLD FRONT. GOOD SETUP FOR IMPRESSIVE WARMING ACROSS THE AREA TODAY AS 850 MB TEMPS RISE INTO THE UPPER TEENS TO LOW 20S CELSIUS WITHIN THE THERMAL RIDGE. COLD FRONT WILL THEN DROP SOUTH THROUGH THE CWA OVERNIGHT. WITH COOLER TEMPS TO FOLLOW FOR TUESDAY.
WEAK TROF OF LOW PRESSURE IS PRESENT ACROSS THE CENTRAL DAKOTAS WITH HIGH PRESSURE OVER THE CENTRAL ROCKIES. A WEAK SURFACE TROF WILL MOVE THROUGH THE AREA.
425 AM MDT MON SEP 21 2015 AN UPPER LEVEL RIDGE WILL BE OVER THE SRN ROCKIES WITH DRY WLY FLOW ALOFT ACROSS NRN CO THRU THE AFTN. SOME OF THE MOIST AIR IS EXPECTED TO MOVE OVER COLORADO AFTER IT GETS SWEPT UP BY A WEAK UPPER TROUGH THAT MOVES NORTHEASTWARD FROM SOUTHERN CALIFORNIA.
UPPER RIDGE TRANSLATES OVER THE EASTERN PART OF THE STATE TODAY AS SUBTROPICAL DISTURBANCE LIFTS NORTHWARD INTO AZ/NM. BUT WARMING TEMPERATURES ALOFT SHOULD YIELD TEMPERATURES ANOTHER 5 DEGREES OR SO WARMER THAN YESTERDAY.
411 AM MDT MON SEP 21 2015 HIGH PRESSURE WILL PERSIST OVER THE AREA TODAY AND TONIGHT BEFORE WE BEGIN TO SEE A TRANSITION TO WETTER CONDITIONS BEGINNING TUESDAY. AND A LOW PRESSURE SYSTEM OFF THE SO CA COAST OFFERING A KICK TO THE TROPICAL REMNANTS AS THEY MOVE S-N THROUGH AZ ON TUE. THE THERMAL RIDGE AT 700 MB WILL STRENGTHEN WITH HIGH TEMPERATURES EXPECTED TO REACH UP TO 10 DEGREES ABOVE NORMAL FOR THE SEASON. LOW TEMPERATURES WILL BE SEVERAL DEGREES WARMER THAN THE PREVIOUS FEW NIGHTS. NUMERICAL HIGH TEMPERATURE GUIDANCE SHOWS A BIG DIFFERENCE BETWEEN THE MAV (DRIER/WARMER) AND THE MET (WETTER/COOLER).
AN UPPER LEVEL LOW PASSING TO THE SOUTH WILL INTRODUCE THE CHANCE OF SHOWERS AND THUNDERSTORMS FOR PARTS OF LOS ANGELES COUNTY LATER TONIGHT INTO TUESDAY. THE THUNDERSTORM COMPLEX IS ASSOCIATED WITH A VORT MAX AND A JET STREAK THAT ARE CIRCLING AN UPPER LOW 360 MILES TO THE SW OF LAX. GRADIENTS ARE TRENDING OFFSHORE WITH HELP FROM THE SFC REFLECTION OF THE UPPER LOW DOWN TO THE SW WEST. THE COMBINATION OF WARM OVERNIGHT LOWS OFFSHORE FLOW AND LOTS OF SUNSHINE WILL ALLOW MAX TEMPS TO CLIMB TO ABOUT 10 DEGREES ABOVE NORMAL STILL THIS IS ABOUT 4 DEGREES COOLER THAN YDY.
WEAK TROUGHING REMAINS ACROSS THE EASTERN CONUS WITH A COUPLE WEAK SHORT WAVES MOVING THROUGH THE WESTERN GREAT LAKES AND OHIO VALLEY REGION. WEAK SHORT WAVE TROUGH PASSES THROUGH THE REGION TODAY INTO THE EASTERN LAKES BY TUESDAY MORNING.
This slightly higher moisture combined with better subsidence from the arrival of the upper ridge, might be enough to produce some isld patches of light fog Tues morning.
VERY WARM TEMPERATURES ARE EXPECTED TUESDAY AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDS NORTHWARD FROM THE SOUTHERN INTO THE CENTRAL PLAINS. SO DESPITE A WARM FRONT LIFTING NORTHWARD THROUGH THE FORECAST AREA.
331 AM CDT MON SEP 21 2015 MAIN FCST CONCERN TODAY IS WHETHER OR NOT WE GET ANY PCPN ACROSS THE CWA AS A WEAK UPPER TROF MOVES ACROSS THE TN VALLEY. ALL SHOW IT FAIRLY DRY IN THE LOWER LAYERS OF THE ATMOSPHERE. MODELS AND STLT TRENDS BOTH ARE SHOWING THAT CLOUDS SHOULD BEGIN TO DISSIPATE BY THIS AFTN AS THE UPPER TROF MOVES EAST OF THE CWA.
550 AM EDT MON SEP 21 2015 HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY AND LINGER RIGHT THROUGH THE WEEK. TEMPERATURES HAVE DROPPED OFF EARLY THIS MORNING, WITH MANY LOCATIONS ACROSS THE NORTH IN THE LOWER TO MID 30S. HIGH PRESSURE WILL BUILD ACROSS NEW ENGLAND TODAY AND TONIGHT, RESULTING IN CLEAR SKIES AND LIGHT WINDS.
FLOW ALOFT BEGINS TURNING SWLY TUESDAY NIGHT AS UPPER TROF DIGS OVER THE GULF OF AK.
MODELS COMING INTO BETTER AGREEMENT WITH STRENGTH/TIMING OF STRONGER THOUGH STILL SOME DIFFERENCES REGARDING HOW QUICKLY THE WARM FRONT WILL LIFT BACK TO THE NORTH TUESDAY NIGHT.
The best chances for precipitation will mainly be on the higher terrain across northwest Montana. This feature will also usher in a cooler airmass so temperatures will mainly be in the 60s and 70s across western Montana with the 70s and 80s prevalent across north central Idaho.
349 AM EDT MON SEP 21 2015 HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER THROUGH THE WEEK. CLOSER TO THE INVERTED TROUGH.