Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 02/28/12


AREA FORECAST DISCUSSION
NWS DENVER CO
551 PM MST MON FEB 27 2012 .UPDATE... && .SHORT TERM...HAVE MADE SOME ADJUSTMENTS TO THE TONIGHT PERIOD OF THE FORECAST. GIVEN OBSERVATIONS...HAVE BACKED OFF ON CHANCES OF SNOW IN THE MOUNTAINS THIS EVENING AS THE STRONG SOUTHWEST FLOW IS NOT CONDUCIVE TO MUCH SHOWER ACTIVITY IN OUR MOUNTAINS. HAVE ALSO ADJUSTED SKY COVER TO MOSTLY CLEAR OVER THE PLAINS EARLY THIS EVENING THEN INCREASE THE CLOUDS GIVEN THE STRATUS DEVELOPING ACROSS FAR SOUTHEAST COLORADO AND WESTERN KANSAS. CHANCES OF ANY PRECIP LOOK VERY LOW OVER EASTERN COLORADO WITH MAINLY DRY AIRMASS IN THE MID AND UPPER LEVELS. HAVE REMOVED MOST OF THE POPS. ALSO BUMPED UP WIND SPEEDS FOR TUESDAY AFTERNOON AS THE TROF SWEEPS ACROSS NORTHERN COLORADO. .AVIATION...MAIN CHANGE TO 00Z TAFS WAS TO INCREASE THE WESTERLY WINDS FOR TUESDAY AFTERNOON AS MODELS AGAIN SEEM TO BE UNDERDOING WIND SPEEDS. LATEST HRRR SHOWS DEN CYCLONE THRU THE NIGHT WITH LOW LEVEL MOISTURE WRAPPING AROUND THE LOW LATER TONIGHT WITH THE POTENTIAL FOR FOG/STRATUS OVER THE TERMINALS. STILL A CLOSE CALL AND MAYBE A BETTER CHANCE AT BJC. LEFT THE VCFG AT KDEN BUT GIVEN CYCLONE WE MAY GET MORE FOG THAN FORECAST. WILL LIKELY MAKE MORE ADJUSTMENTS THIS EVENING. NOT VERY CONFIDENT ON PRECIP OCCURRING AT LOCAL TERMINALS BUT DID LEAVE A VCSH IN FOR NOW. && .PREV DISCUSSION... /ISSUED 323 PM MST MON FEB 27 2012/ SHORT TERM...UPPER TROUGH HEADING TOWARDS THE GREAT BASIN AT THIS TIME WITH FAIRLY TIGHT SOUTHERLY FLOW ALOFT OVER THE REGION. AT THE SURFACE...GUSTY SOUTHERLY WINDS CONTINUING ACROSS THE PLAINS MAINLY FROM DENVER EASTWARD. MODELS STILL PERSISTENT WITH WEAKENING THAT GRADIENT DURING THE EVENING...WITH SURFACE WINDS DECREASING A RESULT. WILL CONTINUE THIS TREND. SATELLITE SHOWING MOISTURE CONTINUING TO SPREAD INTO WESTERN COLORADO...WITH RADAR SHOWING SOME ECHOES ACROSS THE WESTERN MOUNTAINS. NOT ALOT CURRENTLY HAPPENING OVER THE NORTHERN AND CENTRAL MOUNTAINS... PERHAPS A FEW ECHOES ACROSS ZONE 31. AS TROUGH MOVES INTO THE GREAT BASIN THIS EVENING...SHOULD SEE MOISTURE INCREASE AND SNOW SPREAD ACROSS THE AREA. SOUTHWEST FLOW ALOFT NOT FAVORABLE FOR GOOD SNOWFALL AND ACCUMULATIONS...BUT WITH INCREASING ASCENT AND LAPSE RATES...LIKELY POPS SEEM WARRANTED WITH THE HIGHEST POPS FOR FAVORED ZONE 31. SNOW AMOUNTS TO BE IN THE 1 TO 3 INCH RANGE. ACROSS PLAINS....SURFACE WINDS TO BECOME SOUTHWEST DURING THE EVENING AS THE SOUTHWEST GRADIENT INCREASES. MOISTURE TO INCREASE ACROSS THE AREA BY MIDNIGHT. LOW LEVELS SLOWING MOISTEN OVERNIGHT AS LOW LEVEL MOISTURE SPREADS NORTHWEST. QUESTION REMAINS HOW MUCH LOW LEVEL MOISTURE MAKES IT TO THE FOOTHILLS. LATEST RUC AS WELL AS THE HI RESOLUTION MODELS BRING THE LOW LEVEL MOISTURE INTO EASTERN ADAMS AND EASTERN ARAPAHOE COUNTIES AROUND 10Z...ENOUGH PERHAPS FOR PATCHY FOG. THIS ALREADY IN THE GRIDS. PRECIP CHANCES LOW OVERNIGHT...WITH THE BEST CHANCE ACROSS ZONE 38 WHERE SOME BANDED PRECIP IS POSSIBLE. MAY BE A RAIN/SNOW MIX FOR A FEW HOURS. ON TUESDAY...THE TROUGH IS EXPECTED TO MOVE ACROSS THE REGION WITH THE BEST DYNAMICS OCCURRING DURING THE MORNING. OROGRAPHICS IMPROVE DURING THE AFTERNOON BUT LIFT IS EAST OF THE MOUNTAINS AND MOISTURE DEPTH DECREASES. STILL A DECENT SHOT OF SNOW EXPECTED FOR THE MOUNTAINS...ESPECIALLY FOR THE MORNING HOURS...WITH ANOTHER 2 TO 5 INCHES. ACROSS PLAINS...BEST CHANCE FOR SNOW LOOKS TO BE DURING THE MORNING WHEN THE DYNAMICS MOVES OVERHEAD. BUT DOWNSLOPE WINDS WILL OFFSET THE SNOW POTENTIAL. SO ANY ACCUMULATION SHOULD BE LESS THAN AN INCH....MAINLY ACROSS ZONE 38. SNOW CHANCES DECREASE DURING THE AFTERNOON AS TROUGH MOVES INTO THE CENTRAL PLAINS AND DOWNSLOPE INCREASES. LATEST MODELS STILL SHOW SOME LIGHT ACCUMULATION ACROSS FAR NORTHEAST CORNER DURING THE AFTERNOON. WILL KEEP CHANCE POPS THERE...BUT AMOUNTS WILL BE LIGHT. AS FOR PRECIP TYPE...THICKESS PROGS SUGGEST ALL SNOW. LONG TERM...A CLOSED UPPER LEVEL LOW MOVING ACROSS THE NORTHERN PLAINS WILL BRING A NORTHWEST FLOW ALOFT TO COLORADO TUESDAY NIGHT. AS THIS SYSTEM EXITS THE REGION...MOUNTAIN SNOW WILL COME TO AN END DURING THE NIGHT. A STABLE LAYER WILL FORM JUST ABOVE RIDGE TOP AND CREATE A MOUNTAIN WAVE. WINDS AT RIDGE TOP WILL BE AROUND 50 KNOTS. THE WAVE WILL ACCELERATE THESE WINDS DOWN THE FOOTHILLS RESULTING IN WIND GUSTS UP TO 80 MPH. WILL ISSUE A HIGH WIND WATCH FOR THE FOOTHILLS AND AREAS AT THE BASE OF THE FOOTHILLS FOR TUESDAY NIGHT AND EARLY WEDNESDAY MORNING. THE WINDS WILL QUICKLY DIE OFF WEDNESDAY AS AN UPPER LEVEL RIDGE QUICKLY PASSES OVER THE STATE. THIS WILL BRING MILD AND DRY CONDITIONS TO NORTHEAST COLORADO. NEXT STORM SYSTEM WILL DIG SOUTH ACROSS THE PACIFIC NORTHWEST AND NORTHERN ROCKIES THURSDAY. THIS SYSTEM WILL LIKELY BRING ANOTHER SHOT OF SNOW TO THE MOUNTAINS...THURSDAY AND FRIDAY. COLD FRONT WILL PUSH SOUTH ACROSS NORTHEAST COLORADO THURSDAY. WINDS WILL BECOME NORTHEAST BEHIND THE FRONT...PRODUCING AN UPSLOPE FLOW. WILL HAVE SCATTERED POPS IN THE FORECAST THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. THE AREA WILL BE ON THE BACKSIDE OF THIS SYSTEM ON FRIDAY. AIRMASS WILL BE SOMEWHAT UNSTABLE AND WILL KEEP LOW POPS FOR NORTHEAST COLORADO IN THE FORECAST. FOR THE MOUNTAINS...THE SLIGHTLY UNSTABLE FLOW OVER THE MOUNTAINS WILL PRODUCE SNOW SHOWERS...THUS WILL HAVE HIGHER POPS OVER THE MOUNTAINS. UPPER LEVEL RIDGE WILL BE ALONG THE WEST COAST SATURDAY. THIS WILL PRODUCE A DRY AND MILD NORTHWEST FLOW OVER COLORADO. THE RIDGE WILL SHIFT EAST THROUGH THE WEEKEND AND EARLY NEXT WEEK. THIS WILL ALLOW TEMPERATURES TO CLIMB ABOVE NORMAL SUNDAY AND MONDAY AS DRY CONDITIONS CONTINUE. ON MONDAY...SOME 60S WILL BE POSSIBLE OVER NORTHEAST COLORADO. AVIATION..STRONG SOUTHERLY GRADIENT TO SLOWLY WEAKEN ACROSS PLAINS THIS EVENING...WITH WINDS DECREASING AT DEN AND APA. WINDS TO BECOME SOUTHWEST AT ALL THE AREA AIRPORTS BY 05Z AS SOUTHWEST FLOW ALOFT INCREASES. MOISTURE TO GRADUALLY INCREASE THIS EVENING...WITH CEILINGS OF 5000-6000 FEET AGL PREVAILING. CHANCE FOR MVFR CEILINGS AT DEN AND APA AFTER 07Z IF LOW LEVEL MOISTURE INCREASES FROM THE SOUTHEAST. SLIGHT CHANCE OF SNOW SHOWERS AFTER 06Z...POSSIBLY MIXED WITH RAIN. BEST CHANCE FOR SNOW TUESDAY MORNING...AS TROUGH MOVES OVERHEAD. VFR CONDITIONS TO PREVAIL...WITH POSSIBLE MVFR CONDITIONS WITH PASSING SNOW SHOWERS. WINDS TO SHIFT TO THE NORTHWEST AFTER 16Z...CONTINUING THROUGH THE DAY WITH SOME GUSTS TO 20 KTS POSSIBLE DURING THE AFTERNOON. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING FOR COZ035-036-038-039. && $$ SHORT TERM...ENTREKIN LONG TERM....MEIER AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS MIAMI FL
720 PM EST MON FEB 27 2012 .AVIATION...THRU. 00Z WED. VFR CONDITIONS WILL PERSIST THROUGH THE BULK OF THE PERIOD WITH MUCH OF THE SHOWER AND THUNDERSTORM COVERAGE REMAINING NORTH OF THE TERMINALS OVER CENTRAL FLORIDA THIS EVENING. LIGHT EASTERLY LOW- LEVEL FLOW WILL CONTINUE THROUGH THE OVERNIGHT HOURS. THERE REMAINS A SLIGHT CHANCE FOR PATCHY FOG DEVELOPING LATE TONIGHT INTO TUESDAY MORNING...MAINLY INLAND AND WEST WHERE MUCH OF THE SHOWER COVERAGE WAS THIS AFTERNOON. 85/AG && .PREV DISCUSSION... /ISSUED 237 PM EST MON FEB 27 2012/ DISCUSSION... AS THE AFTERNOON PROGRESSES THE CHANCES FOR STRONG ISOLATED THUNDERSTORMS IS SOLIDIFYING MORE BASED ON RADAR, SATELLITE AND SURFACE OBSERVATIONS AROUND THE REGION. THE RUC RAPID REFRESH MODEL INSISTS IN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER INTERIOR SECTIONS OF SOUTH FLORIDA THIS EVENING. THE RUC SHOWS THE HIGHEST COVERAGE AFTER 4 PM EST. CURRENTLY, THE RADAR IS SHOWING AN INCREASE IN SHOWERS SOUTHWEST OF THE LAKE. AT THE PRESENT TIME THE ONLY LIGHTNING IN THE AREA IS ASSOCIATED WITH THE STORMS NORTH OF THE LAKE OUTSIDE OF OUR CWA. ANOTHER IMPORTANT FACTOR IS THE WEST COAST SEA BREEZE, WHICH IS CURRENTLY INLAND PASSED NAPLES, IS FORECAST TO CONTINUE TO MOVE EAST AND COLLIDE WITH THE EAST AND SOUTHEAST WINDS OVER THE EASTERN TWO THIRDS OF SOUTH FLORIDA. TEMPERATURE MEASUREMENTS FROM DIFFERENT AIRPLANES ACROSS SOUTH FLORIDA INDICATE THAT THE CAP BETWEEN 600 TO 700 MB IS STILL PRESENT WITH SOME HINTS OF SOME CAP EROSION AS FORECAST BY THE RUC MODEL. WITH THESE CONDITIONS THERE IS A SLIGHT CHANCE OF THUNDERSTORMS LATE THIS AFTERNOON INTO THIS EVENING OVER INTERIOR AREAS OF SOUTH FLORIDA. THE PRIMARY IMPACTS FROM THE STORMS WILL BE LIGHTNING STRIKES, HAIL, GUSTY WINDS, AND LOCALLY HEAVY RAINFALL. THE STRONGEST STORMS WILL BE CAPABLE OF PRODUCING HAIL UP TO NICKEL SIZE HAIL ESPECIALLY AROUND THE LAKE OKEECHOBEE AREA WHERE THE SEA BREEZE AND LAKE BREEZES COLLIDE LATE THIS AFTERNOON INTO EARLY THIS EVENING. THE MOST LIKELY TIME PERIOD FOR CONVECTION WILL BE FROM 4 TO 8 PM SINCE WE STILL NEED MORE TIME FOR THE CAP TO ERODE FURTHER. CURRENT SATELLITE IMAGE SHOWS THAT THE CLOUD TOPS OF MOST OF THE SHOWERS ARE BEGINNING TO BLOW TO THE EAST SOUTHEAST AT AROUND 20000 FEET, WHICH SHOWS THAT SOME OF THESE SHOWERS ARE BEGINNING TO BREAK THROUGH THE CAP. AFTER TODAY THE REST OF THE WEEK LOOKS DRY WITH THE EXCEPTION OF A FEW SHOWERS STILL POSSIBLE FOR TUESDAY ESPECIALLY OVER THE EAST AND CENTRAL SECTION OF SOUTH FLORIDA. THE NEXT TIME FOR SHOWERS IS EXPECTED FOR SUNDAY AS A COLD FRONT IS FORECAST TO APPROACH SOUTH FLORIDA. HOWEVER, THERE IS STILL CONSIDERABLE UNCERTAINTY ABOUT THE STRENGTH AND TIMING OF THIS FRONT. MARINE... BENIGN MARINE CONDITIONS WILL ESTABLISH ON TUESDAY WITH THE REST OF THE WEEK HAVING SEAS OF 2 TO 3 FEET. NO FIRE WEATHER CONCERNS ARE EXPECTED THIS WEEK. A FEW HOURS OF RELATIVE HUMIDITY VALUES IN THE 40S ARE POSSIBLE THURSDAY AND FRIDAY OVER GLADES AND HENDRY...OTHERWISE THE NEXT CHANCE FOR LOWER RELATIVE HUMIDITY VALUES, BUT STILL ABOVE FIRE THRESHOLDS IS FOR SUNDAY WITH A LOT OF UNCERTAINTY STILL WITH THIS FORECAST. AVIATION...(ISSUED AT 1228 PM EST MON FEB 27 2012) THE EAST AND WEST COAST SEA BREEZES WILL CONTINUE TO DEVELOP AND PUSH INLAND THIS AFTERNOON. THIS WILL KEEP THE EAST COAST TAF SITES IN A SOUTHEAST WIND FLOW AT 15 TO 20 KNOTS...WHILE KAPF TAF SITE BECOMES SOUTHWEST AT 5 TO 10 KNOTS AROUND 19Z THIS AFTERNOON. THERE COULD BE A FEW SHOWERS AROUND THE TAF SITES OF KPBI...KFLL...KFXE...AND KAPF THIS AFTERNOON AS THE SEA BREEZES PUSHES INLAND. THE WINDS WILL THEN DECREASE TO LESS THAN 5 KNOTS AT ALL OF THE TAF SITES THIS EVENING INTO TONIGHT AND CONTINUE TO BE EASTERLY. THE WEATHER WILL ALSO REMAIN DRY TONIGHT AT ALL OF THE TAF SITES. THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS THIS AFTERNOON INTO TONIGHT AT ALL OF THE TAF SITES. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 71 83 71 82 / 20 10 - 10 FORT LAUDERDALE 72 82 72 82 / 20 10 - - MIAMI 72 84 71 83 / 20 10 - - NAPLES 68 85 67 84 / 10 10 - - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...60/BD AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION...CORRECTED TYPO IN AVIATION SECTION
NWS QUAD CITIES IA IL
1139 AM CST SUN FEB 26 2012 .AVIATION... STRONG LOW PRESSURE WILL CONTINUE PASSING NORTH OF THE TERMINALS. WINDS WILL BE THE MAIN CONCERN REST OF TDY. TIGHT MSLP GRADIENT AND STEEP LOW LEVEL LAPSE RATES MIXING DOWN HIGHER WINDS ALOFT WILL RESULT IN WINDY CONDITIONS WITH WINDS SUSTAINED 15-25 KTS AND GUSTING 25-35 KTS WHILE VEERING FROM S TO SW THIS AFTN. AS THE LOW PASSES THIS EVE IT WILL DRAG A COLD FRONT THROUGH TERMINALS. WINDS WILL DIMINISH TO AROUND 10 KTS EARLY EVE FROM SW BEFORE VEERING TO W/NW WITH THE PASSAGE OF FRONT WITH GUSTS NEAR 20 KTS POSSIBLE AT TIMES. COULD SEE SOME LOWER CLOUDS TICKLE KDBQ TERMINAL LATE TNGT AND MON AM... WITH ADDITIONAL ST/SC WITH MVFR BASES POSSIBLE MID-LATE AM KCID-KMLI WITH SFC HEATING AND COLD CYCLONIC FLOW. CANT RULE OUT PERIOD OF MVFR CIGS AT KDBQ BUT CONFIDENCE TOO LOW FOR INCLUSION ATTIM. && .PREV DISCUSSION... /ISSUED 538 AM CST SUN FEB 26 2012/ UPDATE... THE STRONGEST NOCTURNAL WAA IS OCCURRING ACROSS THE CWFA BASED ON THE 3 HR PRESSURE FALLS. THIS WAA COMBINED WITH THE PV0.5 ANOMALY MOVING THROUGH IS CREATING THE STRONG SUSTAINED WINDS NORTH OF I-80 AND WEST OF THE MISSISSIPPI. RUC TRENDS SHOW THE PV0.5 ANOMALY EXITING THE CWFA BY OR SHORTLY AFTER SUNRISE SO SUSTAINED WINDS SHOULD DIMINISH. A SIDE AFFECT OF THE STRONGER WINDS IS THAT TEMPERATURES ARE RESPONDING QUICKER THAN FCST. THIS TREND WILL NEED TO BE EVALUATED FURTHER TO SEE IF RAISING MAX TEMPS FOR TODAY IS WARRANTED. .08.. PREV DISCUSSION... /ISSUED 313 AM CST SUN FEB 26 2012/ SYNOPSIS... 06Z SFC ANALYSIS HAS A LOW WEST NORTHWEST OF KPIR AND ANOTHER NEAR KHSI. A WARM FRONT RAN SOUTH FROM THE KPIR LOW TO THE LOW NEAR KHSI. A DEVELOPING WARM FRONT RAN FROM THE KHSI LOW SOUTHEAST INTO CENTRAL MISSOURI. DEW POINTS WERE GENERALLY IN THE TEENS AND 20S ACROSS THE MIDWEST AND PLAINS. SATELLITE SHOWS PLENTY OF MID AND UPPER LEVEL CLOUDS ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST. SHORT TERM...TODAY AND TONIGHT... WINDY BUT DRY CONDITIONS WILL BE SEEN ACROSS THE CWFA FOR THE NEXT 36 HRS. THE TWO QUESTIONS FOR TODAY IS HOW WARM WILL IT GET AND WHETHER HEADLINES ARE NEEDED FOR THE WIND. THE SNOW PACK ACROSS THE CWFA IS COLD AND VERY COMPACTED. THUS CONSIDERABLE ENERGY WILL GO INTO WARMING IT UP TO PROMOTE MELTING. AS A RESULT TEMPERATURES WILL BE HELD DOWN OVER THE NORTHERN HALF OF THE CWFA WHERE THE SNOW PACK IS THE DEEPEST. A COMPLETE MELT SHOULD OCCUR TODAY ACROSS THE SOUTHERN 40 PERCENT OF THE CWFA WITH AREAS FROM THE I-80 CORRIDOR UP TO HWY 30 SEEING NEARLY A COMPLETE MELT. THE NORTHERN THIRD OF THE CWFA SHOULD SEE SNOW DEPTH REDUCED BY ONE THIRD TO ONE HALF BY EVENING. THUS A LARGE TEMPERATURE GRADIENT SHOULD BE SEEN ACROSS THE CWFA TODAY WITH LOWER 40S IN THE FAR NORTH TO NEAR 60 IN THE EXTREME SOUTH. AS FOR HEADLINES FOR WIND...THE SNOW PACK WILL HAVE A STABILIZING AFFECT ON LOW LEVEL LAPSE RATES DURING THE DAY. INDEED THE MODELS SHOW THIS TO VARYING DEGREES WITH POTENTIALLY ONLY THE SOUTH QUARTER TO THIRD OF THE CWFA SEEING STEEP LAPSE RATES AND DEEPER MIXING BY MID TO LATE AFTERNOON. CURRENTLY...THERE IS A WEAK POTENTIAL VORTICITY ANOMALY WORKING ACROSS THE NORTHWEST CWFA WHICH IS JUST AHEAD OF THE 500 METER WIND MAX OF 50-60 KTS. THIS PV ANOMALY MOVES OUT OF THE CWFA BY SUNRISE AND THE 500 METER WIND MAX IS JUST EAST OF THE CWFA BY MID DAY. IF WINDS WERE TO ACHIEVE ADVISORY CRITERIA IT WOULD BE DURING A NARROW WINDOW OF OPPORTUNITY FROM LATE MORNING UNTIL EARLY AFTERNOON DURING THE STRONGEST DIURNAL HEATING. THE LACK OF DEEP MIXING UNTIL MID TO LATE AFTERNOON WHEN THE PRESSURE GRADIENT IS STARTING TO RELAX SUGGESTS THAT SUSTAINED WINDS AND GUSTS WILL FALL SHORT OF ADVISORY CRITERIA. HOWEVER...IT WILL BE QUITE WINDY AND WILL MENTION THAT IN THE HWO. TONIGHT...THE COLD FRONT SWEEPS THROUGH THE AREA UNDER BREEZY CONDITIONS. OTHER THAN SOME PASSING CLOUDS THE FRONTAL PASSAGE WILL BE DRY. 08.. LONG TERM...MONDAY THROUGH NEXT SATURDAY... PRIMARY FOCUS FOR THE LONGER RANGE REMAINS THE STRONG SYSTEM MOVING THROUGH THE REGION TUESDAY THROUGH WEDNESDAY NIGHT. THE 00Z MODEL RUNS REMAIN REASONABLY CLOSE ON THE TIMING AND TRACK OF THE UPPER TROF/LOW AND THE SURFACE LOW. THE MAJORITY OF THE SOLUTIONS TRACK THE SURFACE LOW ALONG THE IA/MN BORDER LATE TUESDAY NIGHT AND WEDNESDAY. THE ECMWF WAS SLIGHTLY SOUTH OF THIS TRACK ON IT/S 00Z RUN...WHICH IS CONSISTENT WITH IT/S PAST FEW RUNS. THE WORK WEEK WILL GET OFF TO A QUIET START. A VIGOROUS UPPER TROF DIGGING INTO CENTRAL CA WILL FORCE SURFACE AND UPPER RIDGING THROUGH THE FORECAST AREA MONDAY AND MONDAY EVENING. WITH THE LOW LEVEL RIDGE TO OUR WEST EARLY MONDAY WE WILL STILL BE COLD ADVECTING IN THE LOW LEVELS...THEN WINDS SHOULD DIE OFF DURING AFTERNOON WITH ARRIVAL OF THE RIDGE AXIS. THIS SHOULD KEEP TEMPERATURES ON THE COOL SIDE...IN THE MID 30S NORTH TO MID 40S IN THE FAR SOUTH. THE RIDGE WILL BE EAST OF THE CWFA BY MONDAY EVENING. SOUTHEAST FLOW BECOMING ESTABLISHED WEST OF THE RIDGE WILL KEEP TEMPERATURES FROM FALLING MUCH DURING THE EVENING AND POSSIBLY RISING SOME AFTER MIDNIGHT AS LOW LEVEL WINDS CONTINUE TO INCREASE. FOR TUESDAY THROUGH WEDNESDAY NIGHT THE WEATHER WILL BECOME MORE ACTIVE AS A STRONG STORM MOVES THROUGH THE REGION. THE UPPER TROF OVER THE WESTERN U.S. DIGS SOUTH INTO AZ/NM BY TUESDAY MORNING THEN LIFTS NORTHEAST INTO THE CENTRAL PLAINS. A SURFACE LOW DEVELOPING OVER EASTERN CO...MOVES INTO EASTERN NE BY 00Z TUESDAY. THE SYSTEM BECOMES VERTICALLY STACKED TUESDAY NIGHT AS IT MOVES EAST THROUGH NRN IA OR SRN MN. MODELS HAVE SLOWED THE SYSTEM DOWN SOME FROM PREVIOUS RUNS RESULTING IN A SLOWER ONSET OF PRECIPITATION. POPS WERE TRIMMED BACK SOME FOR LATE MONDAY NIGHT WITH SLIGHT CHANCE POPS LIMITED TO THE WESTERN MOST ROW OF COUNTIES. ANY PRECIP BEGINNING BEFORE 12Z TUESDAY WOULD LIKELY BE FZRA/SN MIX IN THE SW AND MAINLY SNOW NW. DURING THE DAY TUESDAY A COMBINATION OF STRONG LOW LEVEL MOISTURE RETURN AND FORCING AHEAD OF THE SYSTEM ARGUES FOR HIGH END LIKELY POPS WEST OF THE RIVER BY THE AFTERNOON AND CHANCE POPS EAST OF THE RIVER. DEVELOPING PRECIPITATION WILL HAVE TO OVERCOME LOW LEVEL DRY AIR DURING THE MORNING SO HELD POPS MAINLY IN THE CHANCE CATEGORY. ANY PRECIPITATION FALLING IN THE MORNING WILL BE A MIX WITH R/FZRA POSSIBLE IN THE SOUTH AND SN/IP IN THE NORTH. BY THE AFTERNOON THE THERMAL PROFILE WARMS ENOUGH FOR ALL RAIN. A HIGH PROBABILITY OF RAIN WILL CONTINUE INTO THE EVENING AS THE SURFACE OCCLUSION LIFTS NORTHEAST THROUGH THE CWFA. MODELS CONTINUE TO SHOW SOME WEAK ELEVATED CAPES ASSOCIATED WITH THE OCCLUDED FRONT SO KEPT A MENTION OF THUNDER DURING THE AFTERNOON AND EVENING. TUESDAY NIGHT THE BETTER CHANCE OF PRECIPITATION WILL BE LIMITED TO THE EVENING THEN THE DRY SLOT WILL MOVE IN AFTER MIDNIGHT. HELD ONTO CHANCE POPS FOR -SN WEDNESDAY WITH THE DRY SLOT OVER THE AREA. THE BETTER CHANCE WILL BE IN THE FAR NORTH NEAR THE NORTHERN EDGE OF THE DRIER AIR. STRONG WESTERLY WINDS WILL SPREAD OVER THE AREA WEDNESDAY AS THE LOW MOVES EAST OF THE AREA. THE SOUTHERN HALF WHERE THERE IS A BETTER CHANCE OF SOME SUN AND DEEPER MIXING COULD SEE SUSTAINED WINDS APPROACHING 30 MPH WITH GUSTS NEAR 40 MPH. THE 00Z RUNS HAVE BACKED OFF ON PRECIP CHANCES OVER THE AREA FOR THE END OF THE WEEK. IT APPEARS A SPLIT FLOW REGIME WILL BE IN PLACE BY DURING THE LATTER PART OF THE WEEK. 00Z ECMWF/GFS SOLUTIONS SHOW NORTHERN/SOUTHERN STREAM TROFS MOVING OUT OF THE WESTERN U.S. AND PHASING EAST OF THE MISSISSIPPI RIVER BY LATE FRIDAY...KEEPING MOST OF THE PRECIPITATION TO OUR EAST. ..DLF.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
538 AM CST SUN FEB 26 2012 .UPDATE... THE STRONGEST NOCTURNAL WAA IS OCCURRING ACROSS THE CWFA BASED ON THE 3 HR PRESSURE FALLS. THIS WAA COMBINED WITH THE PV0.5 ANOMALY MOVING THROUGH IS CREATING THE STRONG SUSTAINED WINDS NORTH OF I-80 AND WEST OF THE MISSISSIPPI. RUC TRENDS SHOW THE PV0.5 ANOMALY EXITING THE CWFA BY OR SHORTLY AFTER SUNRISE SO SUSTAINED WINDS SHOULD DIMINISH. A SIDE AFFECT OF THE STRONGER WINDS IS THAT TEMPERATURES ARE RESPONDING QUICKER THAN FCST. THIS TREND WILL NEED TO BE EVALUATED FURTHER TO SEE IF RAISING MAX TEMPS FOR TODAY IS WARRANTED. ..08.. && .AVIATION... 12Z BALLOON FLIGHT SHOWS WINDS OF 40 KTS ARND 1.5KFT AGL. LLWS IS LIKELY OR HAS A HIGH PROBABILITY OF OCCURRING THROUGH 15Z/26 AT 1.5-2.0KFT AGL. AFT 15Z/26 SUSTAINED WINDS OVR 20KTS WILL BE DVLPG WITH VFR CONDITIONS. AFT 00Z/27 VFR CONDITIONS WILL CONTINUE WITH A FRONTAL PASSAGE. LLWS APPEARS TO BE MARGINAL AFT 00Z/27 AND WAS NOT INCLUDED IN THE 12Z TAFS. ..08.. && .PREV DISCUSSION... /ISSUED 313 AM CST SUN FEB 26 2012/ SYNOPSIS... 06Z SFC ANALYSIS HAS A LOW WEST NORTHWEST OF KPIR AND ANOTHER NEAR KHSI. A WARM FRONT RAN SOUTH FROM THE KPIR LOW TO THE LOW NEAR KHSI. A DEVELOPING WARM FRONT RAN FROM THE KHSI LOW SOUTHEAST INTO CENTRAL MISSOURI. DEW POINTS WERE GENERALLY IN THE TEENS AND 20S ACROSS THE MIDWEST AND PLAINS. SATELLITE SHOWS PLENTY OF MID AND UPPER LEVEL CLOUDS ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST. SHORT TERM...TODAY AND TONIGHT... WINDY BUT DRY CONDITIONS WILL BE SEEN ACROSS THE CWFA FOR THE NEXT 36 HRS. THE TWO QUESTIONS FOR TODAY IS HOW WARM WILL IT GET AND WHETHER HEADLINES ARE NEEDED FOR THE WIND. THE SNOW PACK ACROSS THE CWFA IS COLD AND VERY COMPACTED. THUS CONSIDERABLE ENERGY WILL GO INTO WARMING IT UP TO PROMOTE MELTING. AS A RESULT TEMPERATURES WILL BE HELD DOWN OVER THE NORTHERN HALF OF THE CWFA WHERE THE SNOW PACK IS THE DEEPEST. A COMPLETE MELT SHOULD OCCUR TODAY ACROSS THE SOUTHERN 40 PERCENT OF THE CWFA WITH AREAS FROM THE I-80 CORRIDOR UP TO HWY 30 SEEING NEARLY A COMPLETE MELT. THE NORTHERN THIRD OF THE CWFA SHOULD SEE SNOW DEPTH REDUCED BY ONE THIRD TO ONE HALF BY EVENING. THUS A LARGE TEMPERATURE GRADIENT SHOULD BE SEEN ACROSS THE CWFA TODAY WITH LOWER 40S IN THE FAR NORTH TO NEAR 60 IN THE EXTREME SOUTH. AS FOR HEADLINES FOR WIND...THE SNOW PACK WILL HAVE A STABILIZING AFFECT ON LOW LEVEL LAPSE RATES DURING THE DAY. INDEED THE MODELS SHOW THIS TO VARYING DEGREES WITH POTENTIALLY ONLY THE SOUTH QUARTER TO THIRD OF THE CWFA SEEING STEEP LAPSE RATES AND DEEPER MIXING BY MID TO LATE AFTERNOON. CURRENTLY...THERE IS A WEAK POTENTIAL VORTICITY ANOMALY WORKING ACROSS THE NORTHWEST CWFA WHICH IS JUST AHEAD OF THE 500 METER WIND MAX OF 50-60 KTS. THIS PV ANOMALY MOVES OUT OF THE CWFA BY SUNRISE AND THE 500 METER WIND MAX IS JUST EAST OF THE CWFA BY MID DAY. IF WINDS WERE TO ACHIEVE ADVISORY CRITERIA IT WOULD BE DURING A NARROW WINDOW OF OPPORTUNITY FROM LATE MORNING UNTIL EARLY AFTERNOON DURING THE STRONGEST DIURNAL HEATING. THE LACK OF DEEP MIXING UNTIL MID TO LATE AFTERNOON WHEN THE PRESSURE GRADIENT IS STARTING TO RELAX SUGGESTS THAT SUSTAINED WINDS AND GUSTS WILL FALL SHORT OF ADVISORY CRITERIA. HOWEVER...IT WILL BE QUITE WINDY AND WILL MENTION THAT IN THE HWO. TONIGHT...THE COLD FRONT SWEEPS THROUGH THE AREA UNDER BREEZY CONDITIONS. OTHER THAN SOME PASSING CLOUDS THE FRONTAL PASSAGE WILL BE DRY. .08.. LONG TERM...MONDAY THROUGH NEXT SATURDAY... PRIMARY FOCUS FOR THE LONGER RANGE REMAINS THE STRONG SYSTEM MOVING THROUGH THE REGION TUESDAY THROUGH WEDNESDAY NIGHT. THE 00Z MODEL RUNS REMAIN REASONABLY CLOSE ON THE TIMING AND TRACK OF THE UPPER TROF/LOW AND THE SURFACE LOW. THE MAJORITY OF THE SOLUTIONS TRACK THE SURFACE LOW ALONG THE IA/MN BORDER LATE TUESDAY NIGHT AND WEDNESDAY. THE ECMWF WAS SLIGHTLY SOUTH OF THIS TRACK ON IT/S 00Z RUN...WHICH IS CONSISTENT WITH IT/S PAST FEW RUNS. THE WORK WEEK WILL GET OFF TO A QUIET START. A VIGOROUS UPPER TROF DIGGING INTO CENTRAL CA WILL FORCE SURFACE AND UPPER RIDGING THROUGH THE FORECAST AREA MONDAY AND MONDAY EVENING. WITH THE LOW LEVEL RIDGE TO OUR WEST EARLY MONDAY WE WILL STILL BE COLD ADVECTING IN THE LOW LEVELS...THEN WINDS SHOULD DIE OFF DURING AFTERNOON WITH ARRIVAL OF THE RIDGE AXIS. THIS SHOULD KEEP TEMPERATURES ON THE COOL SIDE...IN THE MID 30S NORTH TO MID 40S IN THE FAR SOUTH. THE RIDGE WILL BE EAST OF THE CWFA BY MONDAY EVENING. SOUTHEAST FLOW BECOMING ESTABLISHED WEST OF THE RIDGE WILL KEEP TEMPERATURES FROM FALLING MUCH DURING THE EVENING AND POSSIBLY RISING SOME AFTER MIDNIGHT AS LOW LEVEL WINDS CONTINUE TO INCREASE. FOR TUESDAY THROUGH WEDNESDAY NIGHT THE WEATHER WILL BECOME MORE ACTIVE AS A STRONG STORM MOVES THROUGH THE REGION. THE UPPER TROF OVER THE WESTERN U.S. DIGS SOUTH INTO AZ/NM BY TUESDAY MORNING THEN LIFTS NORTHEAST INTO THE CENTRAL PLAINS. A SURFACE LOW DEVELOPING OVER EASTERN CO...MOVES INTO EASTERN NE BY 00Z TUESDAY. THE SYSTEM BECOMES VERTICALLY STACKED TUESDAY NIGHT AS IT MOVES EAST THROUGH NRN IA OR SRN MN. MODELS HAVE SLOWED THE SYSTEM DOWN SOME FROM PREVIOUS RUNS RESULTING IN A SLOWER ONSET OF PRECIPITATION. POPS WERE TRIMMED BACK SOME FOR LATE MONDAY NIGHT WITH SLIGHT CHANCE POPS LIMITED TO THE WESTERN MOST ROW OF COUNTIES. ANY PRECIP BEGINNING BEFORE 12Z TUESDAY WOULD LIKELY BE FZRA/SN MIX IN THE SW AND MAINLY SNOW NW. DURING THE DAY TUESDAY A COMBINATION OF STRONG LOW LEVEL MOISTURE RETURN AND FORCING AHEAD OF THE SYSTEM ARGUES FOR HIGH END LIKELY POPS WEST OF THE RIVER BY THE AFTERNOON AND CHANCE POPS EAST OF THE RIVER. DEVELOPING PRECIPITATION WILL HAVE TO OVERCOME LOW LEVEL DRY AIR DURING THE MORNING SO HELD POPS MAINLY IN THE CHANCE CATEGORY. ANY PRECIPITATION FALLING IN THE MORNING WILL BE A MIX WITH R/FZRA POSSIBLE IN THE SOUTH AND SN/IP IN THE NORTH. BY THE AFTERNOON THE THERMAL PROFILE WARMS ENOUGH FOR ALL RAIN. A HIGH PROBABILITY OF RAIN WILL CONTINUE INTO THE EVENING AS THE SURFACE OCCLUSION LIFTS NORTHEAST THROUGH THE CWFA. MODELS CONTINUE TO SHOW SOME WEAK ELEVATED CAPES ASSOCIATED WITH THE OCCLUDED FRONT SO KEPT A MENTION OF THUNDER DURING THE AFTERNOON AND EVENING. TUESDAY NIGHT THE BETTER CHANCE OF PRECIPITATION WILL BE LIMITED TO THE EVENING THEN THE DRY SLOT WILL MOVE IN AFTER MIDNIGHT. HELD ONTO CHANCE POPS FOR -SN WEDNESDAY WITH THE DRY SLOT OVER THE AREA. THE BETTER CHANCE WILL BE IN THE FAR NORTH NEAR THE NORTHERN EDGE OF THE DRIER AIR. STRONG WESTERLY WINDS WILL SPREAD OVER THE AREA WEDNESDAY AS THE LOW MOVES EAST OF THE AREA. THE SOUTHERN HALF WHERE THERE IS A BETTER CHANCE OF SOME SUN AND DEEPER MIXING COULD SEE SUSTAINED WINDS APPROACHING 30 MPH WITH GUSTS NEAR 40 MPH. THE 00Z RUNS HAVE BACKED OFF ON PRECIP CHANCES OVER THE AREA FOR THE END OF THE WEEK. IT APPEARS A SPLIT FLOW REGIME WILL BE IN PLACE BY DURING THE LATTER PART OF THE WEEK. 00Z ECMWF/GFS SOLUTIONS SHOW NORTHERN/SOUTHERN STREAM TROFS MOVING OUT OF THE WESTERN U.S. AND PHASING EAST OF THE MISSISSIPPI RIVER BY LATE FRIDAY...KEEPING MOST OF THE PRECIPITATION TO OUR EAST. ..DLF.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
313 AM CST SUN FEB 26 2012 .SYNOPSIS... 06Z SFC ANALYSIS HAS A LOW WEST NORTHWEST OF KPIR AND ANOTHER NEAR KHSI. A WARM FRONT RAN SOUTH FROM THE KPIR LOW TO THE LOW NEAR KHSI. A DEVELOPING WARM FRONT RAN FROM THE KHSI LOW SOUTHEAST INTO CENTRAL MISSOURI. DEW POINTS WERE GENERALLY IN THE TEENS AND 20S ACROSS THE MIDWEST AND PLAINS. SATELLITE SHOWS PLENTY OF MID AND UPPER LEVEL CLOUDS ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST. && .SHORT TERM...TODAY AND TONIGHT... WINDY BUT DRY CONDITIONS WILL BE SEEN ACROSS THE CWFA FOR THE NEXT 36 HRS. THE TWO QUESTIONS FOR TODAY IS HOW WARM WILL IT GET AND WHETHER HEADLINES ARE NEEDED FOR THE WIND. THE SNOW PACK ACROSS THE CWFA IS COLD AND VERY COMPACTED. THUS CONSIDERABLE ENERGY WILL GO INTO WARMING IT UP TO PROMOTE MELTING. AS A RESULT TEMPERATURES WILL BE HELD DOWN OVER THE NORTHERN HALF OF THE CWFA WHERE THE SNOW PACK IS THE DEEPEST. A COMPLETE MELT SHOULD OCCUR TODAY ACROSS THE SOUTHERN 40 PERCENT OF THE CWFA WITH AREAS FROM THE I-80 CORRIDOR UP TO HWY 30 SEEING NEARLY A COMPLETE MELT. THE NORTHERN THIRD OF THE CWFA SHOULD SEE SNOW DEPTH REDUCED BY ONE THIRD TO ONE HALF BY EVENING. THUS A LARGE TEMPERATURE GRADIENT SHOULD BE SEEN ACROSS THE CWFA TODAY WITH LOWER 40S IN THE FAR NORTH TO NEAR 60 IN THE EXTREME SOUTH. AS FOR HEADLINES FOR WIND...THE SNOW PACK WILL HAVE A STABILIZING AFFECT ON LOW LEVEL LAPSE RATES DURING THE DAY. INDEED THE MODELS SHOW THIS TO VARYING DEGREES WITH POTENTIALLY ONLY THE SOUTH QUARTER TO THIRD OF THE CWFA SEEING STEEP LAPSE RATES AND DEEPER MIXING BY MID TO LATE AFTERNOON. CURRENTLY...THERE IS A WEAK POTENTIAL VORTICITY ANOMALY WORKING ACROSS THE NORTHWEST CWFA WHICH IS JUST AHEAD OF THE 500 METER WIND MAX OF 50-60 KTS. THIS PV ANOMALY MOVES OUT OF THE CWFA BY SUNRISE AND THE 500 METER WIND MAX IS JUST EAST OF THE CWFA BY MID DAY. IF WINDS WERE TO ACHIEVE ADVISORY CRITERIA IT WOULD BE DURING A NARROW WINDOW OF OPPORTUNITY FROM LATE MORNING UNTIL EARLY AFTERNOON DURING THE STRONGEST DIURNAL HEATING. THE LACK OF DEEP MIXING UNTIL MID TO LATE AFTERNOON WHEN THE PRESSURE GRADIENT IS STARTING TO RELAX SUGGESTS THAT SUSTAINED WINDS AND GUSTS WILL FALL SHORT OF ADVISORY CRITERIA. HOWEVER...IT WILL BE QUITE WINDY AND WILL MENTION THAT IN THE HWO. TONIGHT...THE COLD FRONT SWEEPS THROUGH THE AREA UNDER BREEZY CONDITIONS. OTHER THAN SOME PASSING CLOUDS THE FRONTAL PASSAGE WILL BE DRY. ..08.. .LONG TERM...MONDAY THROUGH NEXT SATURDAY... PRIMARY FOCUS FOR THE LONGER RANGE REMAINS THE STRONG SYSTEM MOVING THROUGH THE REGION TUESDAY THROUGH WEDNESDAY NIGHT. THE 00Z MODEL RUNS REMAIN REASONABLY CLOSE ON THE TIMING AND TRACK OF THE UPPER TROF/LOW AND THE SURFACE LOW. THE MAJORITY OF THE SOLUTIONS TRACK THE SURFACE LOW ALONG THE IA/MN BORDER LATE TUESDAY NIGHT AND WEDNESDAY. THE ECMWF WAS SLIGHTLY SOUTH OF THIS TRACK ON IT/S 00Z RUN...WHICH IS CONSISTENT WITH IT/S PAST FEW RUNS. THE WORK WEEK WILL GET OFF TO A QUIET START. A VIGOROUS UPPER TROF DIGGING INTO CENTRAL CA WILL FORCE SURFACE AND UPPER RIDGING THROUGH THE FORECAST AREA MONDAY AND MONDAY EVENING. WITH THE LOW LEVEL RIDGE TO OUR WEST EARLY MONDAY WE WILL STILL BE COLD ADVECTING IN THE LOW LEVELS...THEN WINDS SHOULD DIE OFF DURING AFTERNOON WITH ARRIVAL OF THE RIDGE AXIS. THIS SHOULD KEEP TEMPERATURES ON THE COOL SIDE...IN THE MID 30S NORTH TO MID 40S IN THE FAR SOUTH. THE RIDGE WILL BE EAST OF THE CWFA BY MONDAY EVENING. SOUTHEAST FLOW BECOMING ESTABLISHED WEST OF THE RIDGE WILL KEEP TEMPERATURES FROM FALLING MUCH DURING THE EVENING AND POSSIBLY RISING SOME AFTER MIDNIGHT AS LOW LEVEL WINDS CONTINUE TO INCREASE. FOR TUESDAY THROUGH WEDNESDAY NIGHT THE WEATHER WILL BECOME MORE ACTIVE AS A STRONG STORM MOVES THROUGH THE REGION. THE UPPER TROF OVER THE WESTERN U.S. DIGS SOUTH INTO AZ/NM BY TUESDAY MORNING THEN LIFTS NORTHEAST INTO THE CENTRAL PLAINS. A SURFACE LOW DEVELOPING OVER EASTERN CO...MOVES INTO EASTERN NE BY 00Z TUESDAY. THE SYSTEM BECOMES VERTICALLY STACKED TUESDAY NIGHT AS IT MOVES EAST THROUGH NRN IA OR SRN MN. MODELS HAVE SLOWED THE SYSTEM DOWN SOME FROM PREVIOUS RUNS RESULTING IN A SLOWER ONSET OF PRECIPITATION. POPS WERE TRIMMED BACK SOME FOR LATE MONDAY NIGHT WITH SLIGHT CHANCE POPS LIMITED TO THE WESTERN MOST ROW OF COUNTIES. ANY PRECIP BEGINNING BEFORE 12Z TUESDAY WOULD LIKELY BE FZRA/SN MIX IN THE SW AND MAINLY SNOW NW. DURING THE DAY TUESDAY A COMBINATION OF STRONG LOW LEVEL MOISTURE RETURN AND FORCING AHEAD OF THE SYSTEM ARGUES FOR HIGH END LIKELY POPS WEST OF THE RIVER BY THE AFTERNOON AND CHANCE POPS EAST OF THE RIVER. DEVELOPING PRECIPITATION WILL HAVE TO OVERCOME LOW LEVEL DRY AIR DURING THE MORNING SO HELD POPS MAINLY IN THE CHANCE CATEGORY. ANY PRECIPITATION FALLING IN THE MORNING WILL BE A MIX WITH R/FZRA POSSIBLE IN THE SOUTH AND SN/IP IN THE NORTH. BY THE AFTERNOON THE THERMAL PROFILE WARMS ENOUGH FOR ALL RAIN. A HIGH PROBABILITY OF RAIN WILL CONTINUE INTO THE EVENING AS THE SURFACE OCCLUSION LIFTS NORTHEAST THROUGH THE CWFA. MODELS CONTINUE TO SHOW SOME WEAK ELEVATED CAPES ASSOCIATED WITH THE OCCLUDED FRONT SO KEPT A MENTION OF THUNDER DURING THE AFTERNOON AND EVENING. TUESDAY NIGHT THE BETTER CHANCE OF PRECIPITATION WILL BE LIMITED TO THE EVENING THEN THE DRY SLOT WILL MOVE IN AFTER MIDNIGHT. HELD ONTO CHANCE POPS FOR -SN WEDNESDAY WITH THE DRY SLOT OVER THE AREA. THE BETTER CHANCE WILL BE IN THE FAR NORTH NEAR THE NORTHERN EDGE OF THE DRIER AIR. STRONG WESTERLY WINDS WILL SPREAD OVER THE AREA WEDNESDAY AS THE LOW MOVES EAST OF THE AREA. THE SOUTHERN HALF WHERE THERE IS A BETTER CHANCE OF SOME SUN AND DEEPER MIXING COULD SEE SUSTAINED WINDS APPROACHING 30 MPH WITH GUSTS NEAR 40 MPH. THE 00Z RUNS HAVE BACKED OFF ON PRECIP CHANCES OVER THE AREA FOR THE END OF THE WEEK. IT APPEARS A SPLIT FLOW REGIME WILL BE IN PLACE BY DURING THE LATTER PART OF THE WEEK. 00Z ECMWF/GFS SOLUTIONS SHOW NORTHERN/SOUTHERN STREAM TROFS MOVING OUT OF THE WESTERN U.S. AND PHASING EAST OF THE MISSISSIPPI RIVER BY LATE FRIDAY...KEEPING MOST OF THE PRECIPITATION TO OUR EAST. ..DLF.. && .AVIATION... LLWS HAS YET TO BE REALIZED ACRS EASTERN IOWA AND ILLINOIS. PROFILES FROM RADARS AND WIND PROFILERS AT 500 METERS HAVE 15-25 KT WNDS. WINDS OF 50-60 KTS AT 500 METERS ARE BEING SEEN IN WESTERN PARTS OF IOWA/MISSOURI. RUC TRENDS BRING THESE WINDS INTO EASTERN IA AND THE MISS RIVER VALLEY ARND SUNRISE. THE THREAT OF LLWS SHOULD BE THE GREATEST IN THE 11Z-14Z/26 TIME FRAME BEFORE MIXING INCREASES SURFACE WIND SPEEDS. OTHERWISE...VFR WX WILL BE SEEN THROUGH 12Z/27. LLWS MAY BE POSSIBLE AFT 00Z/26 WITH FRONTAL PASSAGE BUT APPEARS MARGINAL RIGHT NOW. ..08.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
346 PM MST SUN FEB 26 2012 .UPDATE... ISSUED AT 335 PM MST SUN FEB 26 2012 OBSERVATIONS ALONG AND NORTH OF HIGHWAY 24 SHOW THAT THE WIND GUSTS HAVE BEEN BELOW CRITERIA FOR A COUPLE OF HOURS...WITH SPEEDS OF 30 TO 35 MPH COMMON. AM EXPECTING THE WINDS TO CONTINUE TO DECLINE SO WILL GO AHEAD AND CANCEL THE WIND ADVISORY. RED FLAG CONDITIONS ARE STILL BEING REPORTED ACROSS THE TRI-STATE AREA SO WILL LET THE RED FLAG WARNING CONTINUE. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 236 PM MST SUN FEB 26 2012 LATEST VISIBLE SATELLITE IMAGERY AND RUC UPPER AIR ANALYSIS SHOW AN UPPER LEVEL TROUGH OVER THE NORTHERN CONUS WITH AN UPPER LEVEL JET OVER NORTHWEST KANSAS AND SOUTHERN NEBRASKA. SURFACE OBSERVATIONS REPORT NORTHWEST WINDS GUSTING 35 TO 45 MPH AS THE STRONGER WINDS ABOVE THE SURFACE MIX DOWN. THE STRONG WINDS THAT PLAGUED THE NORTHERN PORTIONS OF THE TRI-STATE AREA WILL COME TO AN END AROUND SUNSET AS TEMPERATURES COOL. DURING THE NIGHT A SURFACE HIGH PRESSURE WILL MOVE EAST THROUGH NEBRASKA...CAUSING THE WINDS TO SWING TO THE NORTH. DURING THE OVERNIGHT HOURS ISENTROPIC ANALYSIS AND RELATIVE HUMIDITY PLOTS SHOW SOME LIFT AND SATURATED AIR MOVING INTO THE AREA FROM THE SOUTH...WHICH WILL LEAD INCREASED CLOUD COVER FROM NORTH TO SOUTH. WITH DRIER AIR IN PLACE AND LIGHT WINDS...TEMPERATURES WILL BE COOLER THAN LAST NIGHT...RANGING FROM THE UPPER TEENS IN SOUTHWEST NEBRASKA TO THE LOWER 20S IN WEST CENTRAL KANSAS. MONDAY THROUGH MONDAY NIGHT...UPPER LOW WILL BE OVER PACIFIC COAST EARLY MONDAY MORNING...AND WILL STILL BE OVER GREAT BASIN EARLY MONDAY EVENING. OVERALL TREND WITH GUIDANCE HAS BEEN TO SLOW DOWN THIS FEATURE. WHILE THERE IS DECENT H7-H5 MOISTURE IN PLACE BY 18Z MONDAY...WITH LIMITED LIFT AND DRY LAYER BELOW H7...I DECIDED AGAINST MENTION OF SPRINKLES MONDAY AFTERNOON. I ADJUSTED TIMING TO KEEP FORECAST DRY THROUGH 03Z...AND TO LIMIT BEST CHANCES IN THE FAR EASTERN PART OF THE CWA...TRIMMING POPS IN THE WEST. WAA OVERNIGHT MONDAY WILL RESULT IN TEMPS INCREASING AFTER MIDNIGHT...WITH LOWS LIKELY LATE MONDAY EVENING. AS A RESULT PRECIP SHOULD MAINLY FALL AS RAIN...THOUGH A BRIEF RAIN/SNOW MIX COULDNT BE RULED OUT IN EASTERN COLORADO. WHILE WINDY CONDITIONS ARE EXPECTED MONDAY...LIMITED MIXING DUE TO CLOUD COVER SHOULD KEEP CONDITIONS BELOW ADVISORY LEVELS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 236 PM MST SUN FEB 26 2012 TUESDAY...THE UPPER LOW WILL DEEPEN AS IT MOVES OUT OF THE INTER-MOUNTAIN WEST TOWARDS THE NEBRASKA PANHANDLE BY MIDDAY TUESDAY. GUIDANCE HAS COME IN GOOD AGREEMENT WITH A NORTHERN TRACK...SPEEDING UP THE EASTWARD THE UPPER LOW. THIS RESULTS IN A DRY SLOT QUICKLY PROGRESSING NORTH OVER THE CWA BY 18Z. I ADJUSTED POPS ACCORDINGLY WITH HIGHEST POPS TUESDAY MORNING...AND THEN DECREASING IN COVERAGE TUESDAY AFTERNOON. I LEFT ISOLATED THUNDERSTORMS IN FORECAST WITH GUIDANCE STILL SHOWING INSTABILITY AXIS ACROSS EASTERN HALF OF CWA. STRONG WINDS ALOFT WILL ALSO LEAD TO STRONG WINDS TUESDAY AS THE SYSTEM MOVES THROUGH THE REGION...WHICH COULD RESULT IN WARNING CRITERIA WINDS (GUSTS 60MPH OR GREATER). WEDNESDAY THROUGH SUNDAY...SHORTWAVE RIDGE WILL BUILD IN THE REGION WEDNESDAY AND THURSDAY...WITH DRY CONDITIONS AND MILD TEMPS CONTINUING. A SHORTWAVE TROUGH IS STILL EXPECTED TO PASS OVER THE REGION THURSDAY NIGHT. MEASURABLE PRECIP CANT BE RULED OUT...SO SLIGHT CHANCE POPS WERE LEFT IN PLACE. THE REMAINDER OF THE FORECAST PERIOD IS EXPECTED TO REMAIN DRY. SEASONAL HIGH TEMPERATURES (MID/UPPER 40S) WILL RETURN FRIDAY AND SATURDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. RIDGE WILL BEGIN TO DEEPEN SUNDAY ACROSS THE WESTERN US...WITH MILD TEMPERATURES RETURNING TO THE CWA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1051 AM MST SUN FEB 26 2012 STRONG NORTHWESTERLY WINDS WILL CONTINUE ACROSS THE REGION BEHIND AN UPPER LEVEL TROUGH THAT MOVED ACROSS SOUTH DAKOTA OVERNIGHT. SUSTAINED WINDS OF 25 TO 30KTS WILL OCCUR AT BOTH TERMINALS...WITH KMCK SEEING HIGHER WIND GUSTS THIS AFTERNOON OF 40 TO 45KTS. GIVEN YESTERDAYS STRONG WINDS PICKING UP DUST...TODAYS STRONG WINDS MAY ALSO LOFT DUST INTO THE LOWER LEVELS REDUCING VISIBILITY. WILL NEED TO MONITOR FOR BLOWING DUST NEAR THE TERMINALS THIS AFTERNOON. WINDS WILL QUICKLY DROP OFF AFTER 00Z BECOMING LIGHT OVERNIGHT AS PRESSURE GRADIENT SLACKENS AND DAYTIME MIXING DROPS OFF. AS SURFACE HIGH PRESSURE MOVES EASTWARD TONIGHT...WINDS WILL SWITCH AROUND TO THE SOUTHEAST BY 14Z TOMORROW MORNING. MID AND UPPER LEVEL CLOUDS WILL INCREASE TOMORROW MORNING AS THE NEXT UPPER LEVEL SYSTEM MOVES INTO THE DESERT SOUTHWEST. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING UNTIL 6 PM MST THIS EVENING FOR COZ252>254. KS...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. NE...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR NEZ079>081. && $$ UPDATE...JTL SHORT TERM...JTL/DR LONG TERM....DR AVIATION...PMM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
236 PM MST SUN FEB 26 2012 .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 236 PM MST SUN FEB 26 2012 LATEST VISIBLE SATELLITE IMAGERY AND RUC UPPER AIR ANALYSIS SHOW AN UPPER LEVEL TROUGH OVER THE NORTHERN CONUS WITH AN UPPER LEVEL JET OVER NORTHWEST KANSAS AND SOUTHERN NEBRASKA. SURFACE OBSERVATIONS REPORT NORTHWEST WINDS GUSTING 35 TO 45 MPH AS THE STRONGER WINDS ABOVE THE SURFACE MIX DOWN. THE STRONG WINDS THAT PLAGUED THE NORTHERN PORTIONS OF THE TRI-STATE AREA WILL COME TO AN END AROUND SUNSET AS TEMPERATURES COOL. DURING THE NIGHT A SURFACE HIGH PRESSURE WILL MOVE EAST THROUGH NEBRASKA...CAUSING THE WINDS TO SWING TO THE NORTH. DURING THE OVERNIGHT HOURS ISENTROPIC ANALYSIS AND RELATIVE HUMIDITY PLOTS SHOW SOME LIFT AND SATURATED AIR MOVING INTO THE AREA FROM THE SOUTH...WHICH WILL LEAD INCREASED CLOUD COVER FROM NORTH TO SOUTH. WITH DRIER AIR IN PLACE AND LIGHT WINDS...TEMPERATURES WILL BE COOLER THAN LAST NIGHT...RANGING FROM THE UPPER TEENS IN SOUTHWEST NEBRASKA TO THE LOWER 20S IN WEST CENTRAL KANSAS. MONDAY THROUGH MONDAY NIGHT...UPPER LOW WILL BE OVER PACIFIC COAST EARLY MONDAY MORNING...AND WILL STILL BE OVER GREAT BASIN EARLY MONDAY EVENING. OVERALL TREND WITH GUIDANCE HAS BEEN TO SLOW DOWN THIS FEATURE. WHILE THERE IS DECENT H7-H5 MOISTURE IN PLACE BY 18Z MONDAY...WITH LIMITED LIFT AND DRY LAYER BELOW H7...I DECIDED AGAINST MENTION OF SPRINKLES MONDAY AFTERNOON. I ADJUSTED TIMING TO KEEP FORECAST DRY THROUGH 03Z...AND TO LIMIT BEST CHANCES IN THE FAR EASTERN PART OF THE CWA...TRIMMING POPS IN THE WEST. WAA OVERNIGHT MONDAY WILL RESULT IN TEMPS INCREASING AFTER MIDNIGHT...WITH LOWS LIKELY LATE MONDAY EVENING. AS A RESULT PRECIP SHOULD MAINLY FALL AS RAIN...THOUGH A BRIEF RAIN/SNOW MIX COULDNT BE RULED OUT IN EASTERN COLORADO. WHILE WINDY CONDITIONS ARE EXPECTED MONDAY...LIMITED MIXING DUE TO CLOUD COVER SHOULD KEEP CONDITIONS BELOW ADVISORY LEVELS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 236 PM MST SUN FEB 26 2012 TUESDAY...THE UPPER LOW WILL DEEPEN AS IT MOVES OUT OF THE INTER-MOUNTAIN WEST TOWARDS THE NEBRASKA PANHANDLE BY MIDDAY TUESDAY. GUIDANCE HAS COME IN GOOD AGREEMENT WITH A NORTHERN TRACK...SPEEDING UP THE EASTWARD THE UPPER LOW. THIS RESULTS IN A DRY SLOT QUICKLY PROGRESSING NORTH OVER THE CWA BY 18Z. I ADJUSTED POPS ACCORDINGLY WITH HIGHEST POPS TUESDAY MORNING...AND THEN DECREASING IN COVERAGE TUESDAY AFTERNOON. I LEFT ISOLATED THUNDERSTORMS IN FORECAST WITH GUIDANCE STILL SHOWING INSTABILITY AXIS ACROSS EASTERN HALF OF CWA. STRONG WINDS ALOFT WILL ALSO LEAD TO STRONG WINDS TUESDAY AS THE SYSTEM MOVES THROUGH THE REGION...WHICH COULD RESULT IN WARNING CRITERIA WINDS (GUSTS 60MPH OR GREATER). WEDNESDAY THROUGH SUNDAY...SHORTWAVE RIDGE WILL BUILD IN THE REGION WEDNESDAY AND THURSDAY...WITH DRY CONDITIONS AND MILD TEMPS CONTINUING. A SHORTWAVE TROUGH IS STILL EXPECTED TO PASS OVER THE REGION THURSDAY NIGHT. MEASURABLE PRECIP CANT BE RULED OUT...SO SLIGHT CHANCE POPS WERE LEFT IN PLACE. THE REMAINDER OF THE FORECAST PERIOD IS EXPECTED TO REMAIN DRY. SEASONAL HIGH TEMPERATURES (MID/UPPER 40S) WILL RETURN FRIDAY AND SATURDAY...WITH NW FLOW OVER THE CENTRAL HIGH PLAINS. RIDGE WILL BEGIN TO DEEPEN SUNDAY ACROSS THE WESTERN US...WITH MILD TEMPERATURES RETURNING TO THE CWA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1051 AM MST SUN FEB 26 2012 STRONG NORTHWESTERLY WINDS WILL CONTINUE ACROSS THE REGION BEHIND AN UPPER LEVEL TROUGH THAT MOVED ACROSS SOUTH DAKOTA OVERNIGHT. SUSTAINED WINDS OF 25 TO 30KTS WILL OCCUR AT BOTH TERMINALS...WITH KMCK SEEING HIGHER WIND GUSTS THIS AFTERNOON OF 40 TO 45KTS. GIVEN YESTERDAYS STRONG WINDS PICKING UP DUST...TODAYS STRONG WINDS MAY ALSO LOFT DUST INTO THE LOWER LEVELS REDUCING VISIBILITY. WILL NEED TO MONITOR FOR BLOWING DUST NEAR THE TERMINALS THIS AFTERNOON. WINDS WILL QUICKLY DROP OFF AFTER 00Z BECOMING LIGHT OVERNIGHT AS PRESSURE GRADIENT SLACKENS AND DAYTIME MIXING DROPS OFF. AS SURFACE HIGH PRESSURE MOVES EASTWARD TONIGHT...WINDS WILL SWITCH AROUND TO THE SOUTHEAST BY 14Z TOMORROW MORNING. MID AND UPPER LEVEL CLOUDS WILL INCREASE TOMORROW MORNING AS THE NEXT UPPER LEVEL SYSTEM MOVES INTO THE DESERT SOUTHWEST. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING UNTIL 6 PM MST THIS EVENING FOR COZ252>254. WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ090. KS...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR KSZ001>004-013>016-027>029-041-042. WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016. NE...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR NEZ079>081. WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR NEZ079>081. && $$ SHORT TERM...JTL/DR LONG TERM....DR AVIATION...PMM
AREA FORECAST DISCUSSION
NWS TOPEKA KS
308 PM CST SUN FEB 26 2012 .DISCUSSION... SHORT RANGE FORECAST - TONIGHT AND MONDAY... CLEAR SKIES AND W-NW DOWNSLOPE WINDS HAVE ALLOWED SURFACE TEMPERATURES TO RISE INTO THE UPPER 50S TO MID 60S ACROSS MOST OF NORTHEAST KANSAS. EXPECT THE WARM AND DRY CONDITIONS TO PERSIST FOR THE REST OF THE AFTERNOON. SURFACE HIGH PRESSURE WILL BUILD INTO THE NORTHERN PLAINS AND NOSE INTO THE FORECAST AREA BRINGING CLEAR SKIES OVERNIGHT WITH CALM WINDS. DO NOT EXPECT MUCH IN THE WAY OF COLD AIR ADVECTION...BUT RADIATIONAL COOLING WILL ALLOW THE BOUNDARY LAYER TO COOL TO BELOW FREEZING. EXPECT SOME COLD AIR ADVECTION TO TRICKLE INTO THE AREA BEHIND THE VERY LIGHT NORTHERLY FLOW FOR MONDAY. MIXING NOT QUITE AS DEEP ON MONDAY AS SUNDAY...SO THAT FACTOR IN COMBINATION WITH THE WEAK COLD AIR ADVECTION WILL KEEP TEMPS ON MONDAY MORE SEASONAL. CLOUDS WILL BE ON THE INCREASE BY MONDAY AFTERNOON/EVENING AS WARM/MOIST AIR GETS ADVECTED NORTHWARD. CONDENSATION AS A RESULT OF THE ISENTROPIC LIFT ASSOCIATED WITH THE WARM AIR ADVECTION WILL LIKELY BEGIN SHORTLY AFTER NOON...WHICH WILL ALSO AID IN KEEPING TEMPERATURES FROM RISING MUCH HIGHER THAN THE LOWER 50S. JL LEIGHTON LONG TERM - MONDAY NIGHT THROUGH SUNDAY... MONDAY NIGHT THROUGH TUESDAY NIGHT... MODEL AGREEMENT IS NOW FAIRLY GOOD IN THE TRACK OF A POTENT NEGATIVELY TILTED UPPER LEVEL TROUGH. THE SURFACE LOW WILL TRACK WELL NORTH OF THE LOCAL FORECAST AREA WITH A SHARP FAST MOVING DRY LINE CROSSING THE AREA BETWEEN 21Z TUESDAY AND 03Z WEDNESDAY. WARM MOIST ADVECTION WILL TAKE PLACE ON MONDAY NIGHT AND TUESDAY MORNING AHEAD OF THE SYSTEM WITH SHOWERS AND A FEW ELEVATED THUNDERSTORMS EXPECTED TO DEVELOP AND MOVE INTO THE AREA MONDAY NIGHT. THIS ACTIVITY SHOULD ALL REMAIN BELOW SEVERE LIMITS WITH SOME LOW END POTENTIAL FOR SMALL HAIL THROUGH NOON ON TUESDAY. WHILE CLOUD COVER WILL BE ABUNDANT THROUGH THE DAY ON TUESDAY... TEMPERATURES WILL WARM NICELY WITH AMPLE WARM ADVECTION. THE CLOUD LAYER WILL ALSO BE RELATIVELY SHALLOW AND LOW BY TUESDAY AFTERNOON...AND A FEW BREAKS WILL BE POSSIBLE AHEAD OF THE DRY LINE BY LATE AFTERNOON. SURFACE DEWPOINTS WILL CLIMB INTO THE MID 50S BY LATE TUESDAY ACROSS MUCH OF THE FORECAST AREA WITH TEMPS IN THE UPPER 50S AND LOW 60S. EXPECT THE DRY LINE TO ENTER THE FORECAST AREA SOMETIME BETWEEN 21Z AND 00Z...AND PUSH EAST INTO MISSOURI ONLY 3 TO 4 HOURS LATER. CONVECTION IS EXPECTED TO DEVELOP IMMEDIATELY ALONG THE DRY LINE BOUNDARY BY LATE AFTERNOON AND CROSS THE FORECAST AREA...BUT SUBSTANTIAL UNCERTAINTY EXISTS REGARDING THE POTENTIAL FOR STRONG TO SEVERE STORMS. CURRENT INDICATIONS ARE THAT 200-500 J/KG OF SURFACE BASED CAPE WILL BE PRESENT IN A NARROW BAND NEAR THE BOUNDARY. THOSE ARE MEAGER VALUES BUT THE MAJORITY OF THIS INSTABILITY WILL BE IN THE LOWEST 15000 FEET OF THE ATMOSPHERE WITH MAX LIFTED INDEX VALUES IN THAT LAYER APPROACHING -5. THIS WOULD SUGGEST THE POTENTIAL FOR SOME STRONGER SHALLOW UPDRAFTS. SHEAR THROUGH THE DEPTH OF THE CONVECTIVE LAYER...ABOUT 0-4 KM...IS 50-60 KTS WHILE 0-1 KM SHEAR IS 30-40 KTS. THESE VALUES ARE MORE THAN SUFFICIENT TO PRODUCE ORGANIZED STORMS WITH SOME POTENTIAL FOR LOW TOPPED SUPERCELL DEVELOPMENT. HOWEVER...THE UNIDIRECTIONAL NATURE OF THE SHEAR MAY SUGGEST MORE OF A QUASI-LINEAR DEVELOPMENT WITH A BIT MORE POTENTIAL FOR DAMAGING WINDS AT THE SURFACE. IT WILL BE DIFFICULT TO GET LARGE HAIL WITH SUCH SHALLOW UPDRAFTS PERHAPS HAVING TROUBLE CLIMBING ABOVE THE -20C LEVEL...BUT AT LEAST SMALL HAIL WOULD REMAIN POSSIBLE. TORNADO POTENTIAL IS NON-ZERO...BUT HIGHLY DEPENDENT UPON DEVELOPMENT OF MORE ROBUST UPDRAFTS...AND STRONG UPDRAFT POTENTIAL IS THE MOST SIGNIFICANT UNCERTAINTY WITH THIS FORECAST. WEDNESDAY THROUGH SUNDAY... WILL DRY OUT QUICKLY BEHIND THIS SYSTEM AND REMAIN DRY WITH A SLIGHT COOL DOWN FOR WEDNESDAY AND A QUICK RECOVERY WITH WARM TEMPS AGAIN ON THURSDAY. A WEAKER STORM SYSTEM WILL THEN CROSS THE PLAINS THURSDAY NIGHT INTO FRIDAY. THIS SYSTEM DOES NOT HAVE A PARTICULARLY STRONG PRECIP SIGNAL BUT APPEARS WORTHY OF AT LEAST A SLIGHT CHANCE OF LIGHT RAIN WITH PERHAPS A MIX TO LIGHT SNOW THURSDAY NIGHT. IT DOES NOT APPEAR TO BE A HIGH IMPACT EVENT AT THIS TIME. EXPECT DRY CONDITIONS AND NEAR NORMAL TEMPERATURES FOR SATURDAY AND SUNDAY. BARJENBRUCH && .AVIATION... VFR CONDITIONS EXPECTED THROUGH 24 HOUR FORECAST PERIOD. EXPECT WINDS TO REMAIN AROUND 10 TO 15 KTS TODAY WITH OCCASIONAL GUSTS UP TO 18 KTS. EXPECT A GRADUAL TRANSITION FROM WESTERLY WINDS TO NORTHERLY OVERNIGHT AND EVENTUALLY N-NE BY MONDAY MORNING. JL && .FIRE WEATHER... DEEP MIXING HAS COMMENCED ACROSS ALL OF NORTHEAST KANSAS BRINGING VERY DRY LOW LEVEL AIR TO THE SURFACE. RUC SOUNDINGS INDICATE THAT THE ATMOSPHERE HAS MIXED TO APPROXIMATELY 800 MB OR 5600 FEET. W-NW WINDS AT THE SURFACE CONTAIN QUITE A BIT OF A DOWNSLOPE TRAJECTORY WHICH HAS AIDED IN WARMING AND DRYING THE AIR. AS A RESULT RELATIVE HUMIDITY VALUES HAVE DROPPED INTO THE MID TEENS THIS AFTERNOON...AND WILL LIKELY REMAIN IN THE MIDDLE TEENS THROUGH AT LEAST SUNSET. WINDS THROUGHOUT THE DAY HAVE BEEN RELATIVELY LIGHT AS OBSERVATIONS HAVE INDICATED 10 TO 15 MPH W-NW WINDS. DUE TO THE DEEP MIXING SOME WIND GUSTS OF UP TO 20-25 MPH ARE POSSIBLE...BUT THOSE GUSTS WILL BE RATHER INFREQUENT. RH VALUES WILL START TO RISE ONCE SURFACE TEMPERATURES BEGIN TO COOL RIGHT AROUND SUNSET. JL && .TOP WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ008>012- 020>024-026-034>040. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
306 AM CST SUN FEB 26 2012 ...UPDATED SHORT TERM, LONG TERM, AND FIRE WEATHER DISCUSSION... .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 258 AM CST SUN FEB 26 2012 A SURFACE COLD WAS CROSSING SOUTHWEST KANSAS AS OF 07Z WITH 4-5MB 3HR PRESSURE RISES EVIDENT ACROSS NORTHWEST KANSAS. WIND SPEEDS THIS MORNING BEHIND THIS FRONT HAVE BEEN AVERAGING BETWEEN 15 AND 20 MPH BRIEFLY. ALL THE MODELS THIS MORNING WERE IN GOOD AGREEMENT WITH MOVING THIS COLD FRONT QUICKLY INTO OKLAHOMA BY DAYBREAK WITH A RIDGE OF HIGH PRESSURE AT THE SURFACE THEN STARTING TO WORK ITS WAY INTO PORTIONS OF FAR WESTERN KANSAS. THE NAM AND GFS PLACES THIS SURFACE RIDGE AXIS FROM NEAR SYRACUSE TO DODGE CITY BY MID DAY AND THEN EXPANDING IT EASTWARD LATE TODAY AND EARLY TONIGHT. NORTHEAST OF THIS RIDGE AXIS THE SURFACE PRESSURE GRADIENT WILL BE A LITTLE STRONGER AND THE BOUNDARY LAYER AND MIXED LAYER WINDS SUPPORTS WIND SPEEDS INCREASING INTO THE 20 TO 25 MPH EARLY THIS AFTERNOON. IN ADDITION DRIER AIR WILL BE FILTERING INTO THE AREA FROM THIS NORTHWEST FLOW WITH BOTH THE NAM AND GFS SUGGESTING THE SURFACE DEWPOINTS WILL FALL BACK INTO SINGLE DIGITS. USING THE NAM AND GFS BOUNDARY LAYER DEWPOINTS AS A GUIDE FOR AFTERNOON DEWPOINTS IT CURRENTLY APPEARS THAT MUCH OF SOUTHWEST AND NORTH CENTRAL KANSAS WILL HAVE RELATIVE HUMIDITIES BOTTOMING AT OR BELOW 15 PERCENT. TAKING THESE LOW RELATIVE HUMIDITIES INTO ACCOUNT ALONG WITH THE GUSTY NORTHWEST WINDS DEVELOPING ACROSS NORTHWEST AND NORTH CENTRAL KANSAS HAVE DECIDED TO ISSUE A RED FLAG WARNING FOR AREAS ALONG AND NORTH OF HIGHWAY 96. FURTHER SOUTH AFTERNOON RELATIVE HUMIDITIES ARE ALSO EXPECTED TO APPROACH 15 PERCENT BUT WIND SPEEDS ARE NOT EXPECTED TO BE AS STRONG. TEMPERATURES TODAY WILL BE COOLER THAN YESTERDAY, HOWEVER BASED ON THE 900-850MB TEMPERATURE TRENDS BETWEEN 00Z SUNDAY AND 00Z MONDAY THE HIGHS TODAY ARE EXPECTED TO RANGE FROM THE LOW TO MID 50S WHICH ARE NEAR CLIMATOLOGY FOR THIS TIME OF YEAR. TONIGHT THE SURFACE HIGH WILL MOVE EAST INTO CENTRAL KANSAS WITH LIGHT NORTH WINDS PERSISTING INTO THE EARLY MORNING HOURS EAST OF DODGE CITY. BOTH THE NAM AND GFS PLACE THE 850MB BAROCLINIC ZONE ACROSS THE TEXAS PANHANDLE AND WESTERN OKLAHOMA OVERNIGHT WITH THE NORTH/NORTHEAST WINDS ACROSS CENTRAL KANSAS KEEPING THE LOWER DEWPOINTS/DRIER AIR IN THE LOWER LEVELS THROUGH 12Z MONDAY. ABOVE THE 850MB LEVEL WARM AIR ADVECTION/ISENTROPIC LIFT WILL BEGIN TO IMPROVE ACROSS SOUTHWEST KANSAS AFTER MIDNIGHT. BASED MODEL SOUNDINGS AND THE 290 INSENTROPIC SURFACE FROM THE NAM AND GFS WILL BRING CLOUDS BACK INTO THE SOUTH/SOUTHWEST BY 09Z AND THEN CONTINUE TO SPREAD THESE CLOUDS NORTH THROUGH 12Z MONDAY. THESE INCREASING CLOUDS IN THE SOUTHWEST SHOULD KEEP TEMPERATURES WARMER THAN GUIDANCE SUNDAY NIGHT. IN NORTH CENTRAL KANSAS WHERE THE LIGHTER WINDS WILL BE LOCATED BETWEEN 06Z AND 12Z MONDAY ALONG WITH A LONGER PERIOD OF CLEAR SKIES WILL TREND TOWARDS THE COOL AS THE MET/MAV. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 258 AM CST SUN FEB 26 2012 NOT MUCH HAS CHANGED SIGNIFICANTLY TO THE OVERALL PATTERN OF THE NUMERICAL MODELS FROM PREVIOUS RUNS WITH RESPECT TO THE EXTENDED FORECAST PERIOD. A HIGH LEVEL OF UNCERTAINTY STILL SURROUNDS THE EVOLUTION OF THE INCOMING TROUGH/PV ANOMALY AND RESULTANT PRECIPITATION/IMPACTS EXPECTATIONS FOR MONDAY AND TUESDAY. AGAIN WITH YESTERDAYS RUN OF THE ECMWF, IT IS STRONGER WITH THE LOW PRESSURE DEVELOPMENT AND THE POSITION OF THE UPPER JET SEEMS TO ALLOW FOR BETTER LIFT AND MID LEVEL FRONTOGENESIS FOR PRECIPITATION ACROSS THE AREA. IN STARK CONTRAST THE GFS AND IT`S MOS FAMILY OF PRODUCTS ARE MUCH DRIER OVER THE AREA SEEMINGLY DRY SLOTTING THE BETTER PART OF WESTERN KANSAS QUICKLY ON TUESDAY. THIS IS MUCH LIKE THE PATTERN OF HOW THE NAM DEVELOPS PRECIPITATION AS WELL. AS A BASELINE FORECAST WE`VE GONE WITH THE NAM 3 HOURLY POPS FOR THE MONDAY AND TUESDAY TIMEFRAME, WITH SOME ADJUSTMENT UPWARD ON TUESDAY TO NOT TOTALLY DISCOUNT THE SLOWER AND DEEPER MORE EVOLVED ECMWF MODEL. A LARGE DEGREE OF UNCERTAINTY ALSO REVOLVES AROUND JUST HOW WINDY THE WESTERLY SURFACE FLOW WILL BE BEHIND THE FRONT. IT IS SAFE TO SAY AT LEAST A LOW END ADVISORY WIND EVENT SHOULD UNFOLD TUESDAY BUT THE POTENTIAL TO PUSH HIGH WIND CRITERIA IS ALSO PLAUSIBLE. THE ALLBLEND FORECAST APPROACH DOES DEVELOP A VERY SLIGHT CHANCE FOR LIGHT SNOW IN THE NORTHERN COUNTIES THURSDAY EVENING, CLOSELY TIED TO THE MID LEVEL COLD POOL AND THE UPPER JET DEFORMATION/700MB TROUGH. THE 850 TO SFC LAYER LOOKS FAIRLY DRY, BUT WITH THE COLD LAYER ALOFT WE CERTAINLY COULDN`T RULE OUT A PERIOD OF FLURRIES OR LIGHT SNOW WITH NO ACCUMULATION. FOR THE BULK OF THE WEEK THE UPPER PATTERN MAINTAINS THE POLAR JET ACROSS THE SOUTHERN HALF OF THE CONUS BEFORE SLOWLY PHASING WITH THE NORTHERN BRANCH JET SEGMENT AND CREATING A POSITIVELY TILTED TROUGH ACROSS THE AREA DURING THE WEEKEND. DURING THIS PERIOD, NO LARGE TEMPERATURE SWINGS ARE EXPECTED WITH HIGHS AROUND NORMAL FOR LATE FEBRUARY INTO EARLY MARCH IN THE LOW TO MID 50S. THE MODELS DO INDICATE SOME SLIGHT CHANCES FOR A LIGHT PRECIPITATION EVENT ASSOCIATED WITH A WEAK FRONTAL PASSAGE FRIDAY NIGHT OR SATURDAY BUT CONFIDENCE IS NOT LARGE ENOUGH TO INTRODUCE SUCH AN EVENT AT THIS POINT ESPECIALLY SINCE GFSMOS ONLY INDICATES ABOUT A 10 PERCENT CHANCE OR LESS OF OCCURRENCE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1108 PM CST SAT FEB 25 2012 LATEST NAM, RUC AND HRRR WERE ALL IN GOOD AGREEMENT WITH A COLD FRONT CROSSING SOUTHWEST KANSAS BETWEEN 06Z AND 09Z SUNDAY. SURFACE OBSERVATIONS DO INDICATED 4-5MB 3HR PRESSURE RISES BEHIND THIS FRONT WITH THE BETTER PRESSURE GRADIENT EARLY THIS MORNING BEING LOCATED AT HAYS. GIVEN THESE PRESSURE TENDENCIES AND THE NEW RUC AND NAM BOUNDARY LAYER WINDS WILL INCREASE WIND SPEEDS AT HAYS TO AROUND 25 KNOTS FOR A BRIEF TIME AFTER FRONTAL PASSAGE. AT DDC AND GCK WIND SPEEDS WILL ALSO INCREASE BUT WIND SPEEDS ARE EXPECTED TO HOVER AROUND 20KTS. THESE NORTHWEST WINDS WILL THEN CONTINUE THROUGH THE DAY ON SUNDAY WITH BOUNDARY LAYER WIND SPEEDS THROUGH 00Z MONDAY AND AVERAGE MIXED LAYER WIND SPEEDS BOTH SUPPORTING KEEPING THESE NORTHWEST WINDS IN THE 15 TO NEAR 25KT RANGE WITH THE STRONGER WINDS FORECAST TO OCCUR AT HAYS. MOISTURE LIMITED TO THE MID-UPPER LEVELS SO VFR CONDITIONS ARE EXPECT TED THROUGH SUNDAY NIGHT. && .FIRE WEATHER... ISSUED AT 258 AM CST SUN FEB 26 2012 LOWER DEWPOINTS WILL RETURN TO MUCH OF WESTERN KANSAS TODAY AS A NORTHWEST FLOW PERSISTS. THESE LOWER DEWPOINTS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES BOTTOMING OUT AT 15 PERCENT OR LESS FOR MUCH OF SOUTHWEST AND NORTH CENTRAL KANSAS. THE NAM AND GFS AVERAGE MIXED LAYER WINDS ACROSS NORTHWEST AND NORTH CENTRAL KANSAS THIS AFTERNOON WILL PRODUCE SURFACE WINDS IN THE 20 TO 25 MPH RANGE WITH HIGHER GUSTS LIKELY. GIVEN THESE WINDS LATER TODAY ALONG WITH LOW AFTERNOON RELATIVE HUMIDITIES...CRITICAL FIRE WEATHER CONDITIONS WILL EXIST ALONG AND NORTH OF HIGHWAY 96. WILL THEREFORE ISSUE A RED FLAG WARNING FOR THIS AREA THIS AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 54 29 47 44 / 0 0 30 50 GCK 52 29 46 42 / 0 10 30 70 EHA 51 29 49 41 / 0 10 30 60 LBL 53 31 49 43 / 0 0 30 60 HYS 54 20 46 41 / 0 0 30 60 P28 58 29 52 48 / 0 0 30 50 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 7 PM CST THIS EVENING FOR KSZ030-031-043>046. && $$ UPDATE...BURGERT SHORT TERM...BURGERT LONG TERM....RUSSELL AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1134 PM CST SAT FEB 25 2012 ...UPDATED AVIATION AND NEAR TERM DISCUSSION... .UPDATE... ISSUED AT 1108 PM CST SAT FEB 25 2012 AS OF 04Z A COLD FRONT EXTENDED ACROSS NORTHWEST KANSAS WITH SURFACE OBSERVATIONS BEHIND THIS FRONT INDICATING 30 TO 35 MPH WINDS REDEVELOPING BEHIND THIS FRONT IN A FEW LOCATIONS. ALSO NOTICING A 4-5MB 3HR PRESSURE RISE WAS ALSO PRESENT BEHIND THIS FRONT. LATEST NAM, RUC, AND HRRR WERE ALL IN GOOD AGREEMENT WITH MOVING THIS COLD FRONT ACROSS MOST OF SOUTHWEST KANSAS BETWEEN MIDNIGHT AND 3 AM WITH THE BETTER SURFACE PRESSURE GRADIENT DURING THIS TIME FRAME BEING MAINLY CONFINED TO NORTH CENTRAL KANSAS. AS A RESULT WILL BE INCREASING WINDS OVERNIGHT BEHIND THIS FRONTAL PASSAGE WITH THE STRONGER WINDS STAYING NEAR THE INTERSTATE 70 CORRIDOR. AFTER 3 AM THESE WINDS WILL BEGIN TO SUBSIDE...HOWEVER GUSTY NORTHWEST WINDS ARE EXPECTED TO RETURN BY MID DAY. THE BOUNDARY LAYER WINDS AND AVERAGE MIXED LAYER WINDS FROM THE NAM AND RUC ARE CURRENTLY SUPPORTING WINDS SUNDAY AFTERNOON CLOSER TO THE NEW MAV, MOSGUIDE, AND CONSMOS GUIDANCE. AS A RESULT WILL ALSO BE INCREASING WINDS DURING THE AFTERNOON INTO THE 15 TO 25 MPH WITH THE STRONGER WIND SPEEDS ONCE AGAIN BEING IN OUR NORTH. THIS WILL INCREASE THE FIRE DANGER LEVELS ACROSS NORTH CENTRAL KANSAS AND POSSIBLY AS FAR SOUTH AS GARDEN CITY, JETMORE AND LARNED. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 145 PM CST SAT FEB 25 2012 THE MAIN FORECAST FOCUS WILL BE ON TEMPERATURES DURING THE PERIOD. WV IMAGERY AND 12Z UPPER AIR ANALYSIS INDICATE AN UPPER LEVEL RIDGE OF HIGH PRESSURE TRANSITIONING EAST ACROSS THE WESTERN HIGH PLAINS. MEANWHILE, AN UPPER LEVEL TROUGH OF LOW PRESSURE IS PUSHING ASHORE INTO THE PACIFIC NORTHWEST. NEAR THE SURFACE, A LEE SIDE TROUGH OF LOW PRESSURE IS STRENGTHENING ACROSS EASTERN COLORADO. SHORT RANGE MODELS INDICATE THE UPPER LEVEL RIDGE PUSHING EAST ACROSS THE CENTRAL PLAINS TONIGHT AND INTO THE GREAT LAKES REGION SUNDAY. AS THIS OCCURS, THE UPPER LEVEL TROUGH IN THE PACIFIC NORTHWEST WILL TRACK EASTWARD ACROSS THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS TONIGHT BRINGING THE POSSIBILITY FOR PRECIP TO THE DAKOTAS INTO EARLY SUNDAY. HOWEVER, DRY CONDITIONS ARE LIKELY TO CONTINUE ACROSS WESTERN KANSAS EVEN AS AN ATTENDANT COLD FRONT BEGINS TO PUSH SOUTHEAST INTO WESTERN KANSAS TONIGHT. EXTREMELY DRY LAYERS NEAR THE SURFACE AND IN THE MID LEVELS, ALONG WITH A LACK OF INSTABILITY, WILL KEEP PRECIP CHANCES AWAY FROM WESTERN KANSAS THROUGH LATE SUNDAY AFTERNOON. TEMPERATURES ARE EXPECTED TO BE A LITTLE WARMER TONIGHT EVEN AS THE AFOREMENTIONED COLD FRONT PUSHES SLOWLY ACROSS MUCH OF WESTERN KANSAS BY SUNRISE SUNDAY MORNING. THE NAM AND GFS SHOW THE COLD FRONT TO BE FAIRLY WEAK WITH H85 TEMPERATURES ONLY DROPPING FROM THE TEENS(C) AHEAD OF THE FRONT TO THE SINGLE DIGITS(C) ON THE BACKSIDE OF THE BOUNDARY. AS A RESULT, LOOK FOR LOWS DOWN INTO THE 30S(F) WITH UPPER 20S(F) STILL POSSIBLE IN OUR NORTH AND WEST. FOR SUNDAY, COOLER AIR WILL FILTER SOUTH INTO WESTERN KANSAS THROUGH THE AFTERNOON KEEPING H85 TEMPERATURES JUST ABOVE 0C ACROSS CENTRAL KANSAS TO NEAR 5C IN OUR FAR SOUTHWEST. SHOULD SEE HIGHS MAINLY IN THE 50S(F) ACROSS THE FORECAST AREA SUNDAY AFTERNOON. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 256 PM CST SAT FEB 25 2012 A SHORTWAVE RIDGE WILL BE GOING THROUGH THE PLAINS ON SUNDAY NIGHT AND MONDAY AHEAD THE NEXT STRONG UPPER LEVEL TROUGH DIGGING INTO THE SOUTHWESTERN CONUS. THE UPPER LEVEL STORM SYSTEM WILL THEN BECOME NEGATIVELY TILTED AS IT MOVES QUICKLY INTO THE NORTHERN AND CENTRAL PLAINS ON TUESDAY. THE TRACK OF THE UPPER LOW WILL STAY NORTH OF KANSAS AND TRACK FROM NORTHEASTERN COLORADO INTO NEBRASKA. SO IT WILL BE WARM ENOUGH FOR RAIN. AS THE WAVE APPROACHES ABUNDANT LOW LEVEL MOISTURE WILL MOVE IN FROM TEXAS BY MONDAY AFTERNOON WITH A SLIGHT CHANCE OF LIGHT SHOWERS WITH UPSLOPE FLOW. THEN FOR MONDAY NIGHT MORE LIGHT RAIN IS EXPECTED WITH SOME DRIZZLE AND LIGHT FOG AS MOIST UPSLOPE FLOW CONTINUES. FOR TUESDAY AFTERNOON AS THE UPPER TROUGH MOVES ACROSS KANSAS A DRYLINE TROUGH WILL PUSH FROM WEST TO EAST ACROSS SOUTHWESTERN KANSAS. A FEW THUNDERSTORMS ARE POSSIBLE TUESDAY MORNING ALONG AND AHEAD OF THE DRYLINE. BY AFTERNOON WITH THE UPPER LEVEL DRY SLOT AND THE DRYLINE MOVING INTO CENTRAL KANSAS SKIES WILL BE CLEARING WITH WINDS INCREASING TO 25 TO 40 MPH. SEVERE THUNDERSTORMS ARE NOT ANTICIPATED AT THIS TIME WITH MUCH OF THE ACTIVITY MOVING EAST OF SAINT JOHN TO PRATT AND MEDICINE LODGE BY AROUND NOON. IF THE SYSTEM MOVES A BIT SLOWER THAN EXPECTED IT IS POSSIBLE SOME OF THE THUNDERSTORMS IN THE FAR EAST CWA COULD HAVE SOME SMALL HAIL, HOWEVER CURRENT INSTABILITY IS NOT IMPRESSIVE WITH WEAK MID LEVEL CAPE AND DEWPOINTS ONLY AROUND 50. ANOTHER UPPER LEVEL SHORTWAVE TROUGH MOVES INTO THE HIGH PLAINS ON THURSDAY WITH A COLD FRONT AND ONLY A SLIGHT CHANCE OF RAIN OR SNOW IN THE FAR NORTH AROUND HAYS TO SCOTT CITY AND NESS CITY ON THURSDAY NIGHT. A REINFORCING UPPER LEVEL TROUGH MOVES INTO THE PLAINS ON FRIDAY WITH A COOLER AIRMASS. BY SATURDAY AS THE UPPER TROUGH MOVES EAST A WARMING TREND BEGINS WITH A LEE TROUGH AND A RETURN TO SOUTHERLY WINDS. OVERNIGHT LOWS WILL BE IN THE 20S ON SUNDAY NIGHT THEN RISE INTO THE 40S ON MONDAY NIGHT AHEAD OF THE STORM SYSTEM. THEN FOR TUESDAY NIGHT INTO FRIDAY NIGHT OVERNIGHT LOWS WILL RANGE FROM 28 TO 35. HIGH TEMPERATURES WILL BE IN THE MID TO UPPER 40S ON MONDAY THEN RISE INTO THE UPPER 50S TO LOWER 60S ON TUESDAY AFTERNOON BEHIND THE STORM SYSTEM AS WINDS TURN STRONG WESTERLY DOWNSLOPE AND WARM. HIGHS WARM FROM THE 50S WEDNESDAY TO THE LOW 60S THURSDAY AHEAD OF THE NEXT COLD FRONT ON THURSDAY NIGHT. HIGHS ON FRIDAY WILL BE AROUND 50 THEN INTO THE LOW TO MID 50S ON SATURDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1108 PM CST SAT FEB 25 2012 LATEST NAM, RUC AND HRRR WERE ALL IN GOOD AGREEMENT WITH A COLD FRONT CROSSING SOUTHWEST KANSAS BETWEEN 06Z AND 09Z SUNDAY. SURFACE OBSERVATIONS DO INDICATED 4-5MB 3HR PRESSURE RISES BEHIND THIS FRONT WITH THE BETTER PRESSURE GRADIENT EARLY THIS MORNING BEING LOCATED AT HAYS. GIVEN THESE PRESSURE TENDENCIES AND THE NEW RUC AND NAM BOUNDARY LAYER WINDS WILL INCREASE WIND SPEEDS AT HAYS TO AROUND 25 KNOTS FOR A BRIEF TIME AFTER FRONTAL PASSAGE. AT DDC AND GCK WIND SPEEDS WILL ALSO INCREASE BUT WIND SPEEDS ARE EXPECTED TO HOVER AROUND 20KTS. THESE NORTHWEST WINDS WILL THEN CONTINUE THROUGH THE DAY ON SUNDAY WITH BOUNDARY LAYER WIND SPEEDS THROUGH 00Z MONDAY AND AVERAGE MIXED LAYER WIND SPEEDS BOTH SUPPORTING KEEPING THESE NORTHWEST WINDS IN THE 15 TO NEAR 25KT RANGE WITH THE STRONGER WINDS FORECAST TO OCCUR AT HAYS. MOISTURE LIMITED TO THE MID-UPPER LEVELS SO VFR CONDITIONS ARE EXPECT TED THROUGH SUNDAY NIGHT. && .PRELIMINARY POINT TEMPS/POPS... DDC 33 55 26 47 / 0 0 0 30 GCK 31 53 25 46 / 0 0 10 30 EHA 32 53 27 49 / 0 0 10 30 LBL 32 54 28 49 / 0 0 0 30 HYS 31 53 24 46 / 0 0 0 30 P28 38 58 33 52 / 0 0 0 30 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BURGERT SHORT TERM...JJOHNSON LONG TERM....KRUSE AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1247 AM EST SUN FEB 26 2012 .SYNOPSIS... WITH COLD WESTERLY WINDS SUBSIDING OVERNIGHT, THE REMAINING SNOW SHOWERS AND BLOWING SNOW WILL END BY DAWN. INCOMING MIDWEST HIGH PRESSURE WILL PROVIDE DRY CONDITIONS SUNDAY THROUGH TUESDAY, WITH TEMPERATURES EVENTUALLY REBOUNDING TO SEASONABLE LEVELS. && .NEAR TERM /THROUGH TODAY/... FOR MIDNIGHT UPDATE...MADE SEVERAL MINOR CHANGES. HELD ONTO POPS SLIGHTLY LONGER WITH RADAR STILL SHOWING RETURNS. UPDATED SKY GRIDS TO ACCOUNT FOR CLEARING SKIES MOVING FROM SOUTHWEST TO NORTHEAST. IN ADDITION...DROPPED OVERNIGHT LOWS A FEW DEGREES WHERE SKIES HAVE ALREADY GONE CLEAR...AS RADIATIONAL COOLING SHOULD BE ABLE TO TAKE EFFECT. PREVIOUS DISCUSSION FOLLOWS. PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR AND NAM MODEL OUTPUT, SNOW SHOWERS AND PATCHES OF BLOWING SNOW SHOULD END BY DAWN SUNDAY. RECENT RADAR AND SATELLITE DATA SHOWS THE REMAINING BANDS OF LAKE EFFECT SNOW SHOWERS CONTINUE TO WEAKEN. INFRARED SATELLITE IMAGERY SHOWS CLOUD TOPS HAVE BEEN WARMING, WHICH SUPPORTS NAM MODEL PROFILE PREDICTION OF A LOWERING SUBSIDENCE INVERSION AND SUBSEQUENT SHRINKING UNSTABLE SURFACE LAYER. SO EXPECT NO MORE THAN SCATTERED SNOW SHOWERS ACROSS THE NORTH AND MOUNTAINS BY MIDNIGHT, AND ONLY FLURRIES AND PARTLY CLOUDY SKIES BY 4 AM. HAVE TWEAKED TEMPERATURES FOR THE OVERNIGHT AND DAYTIME SUNDAY, CONSIDERING REFRIGERATIVE RADIATIVE EFFECTS OF FRESH SNOW COVER. HENCE HAVE LOWS TONIGHT AND HIGHS SUNDAY AS MUCH AS 3 DEGREES COLDER THAN THE PREFERRED COLDER NAM MOS. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... RECENT SREF MODEL OUTPUT SHOWS CANADIAN LOW PRESSURE PASSING EASTWARD THROUGH THE GREAT LAKES SUNDAY NIGHT, THAT WILL PUSH A WEAK COLD FRONT SOUTHWARD INTO THE UPPER OHIO VALLEY LATE SUNDAY NIGHT AND DAYTIME MONDAY. SYSTEM WILL HAVE LIMITED MOISTURE INFUSION, SO AT THIS JUNCTURE EXPECT ONLY AN INCREASE IN CLOUDS. HIGH PRESSURE,MOVING EAST FROM THE NORTHERN PLAINS, WILL MAINTAIN DRY CONDITIONS TUESDAY, AS CONSENSUS OF GFS AND NAM MOS SHOW TEMPERATURES MODERATING TO ABOVE NORMAL LEVELS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... MEDIUM RANGE MODELS SHOW A CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW TRACKING FROM THE CENTRAL PLAINS INTO THE LOWER GREAT LAKES/UPPER OHIO VALLEY BY WEDNESDAY NIGHT...AND OFF THE ATLANTIC COAST THURSDAY. EXPECT RAIN TO SPREAD EAST INTO THE FORECAST AREA BY LATE TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY MORNING. FORECAST DAYTIME TEMPERATURES ON WEDNESDAY SHOW A LARGE NORTH TO SOUTH RANGE AS A WARM FRONT CREEPS NORTHWARD INTO THE UPPER OHIO VALLEY. TEMPERATURES COULD PUSH WELL INTO THE 50S TO NEAR 60 IN EAST CENTRAL OHIO WHILE HOLDING IN THE 40S NORTH OF I-80. SCATTERED SHOWERS BEHIND THE SYSTEM MAY MIX WITH SNOW LATE WEDNESDAY NIGHT AND EARLY THURSDAY MAINLY ACROSS THE NORTH AS COLDER AIR MOVES IN. A BREAK FROM PRECIPITATION IS EXPECTED THURSDAY NIGHT AND EARLY FRIDAY UNDER WEAK RIDGING. THE NEXT SYSTEM WILL MOVE INTO THE GREAT LAKES AND SWING A COLD FRONT ACROSS THE REGION SATURDAY. SCATTERED SHOWERS CAN BE EXPECTED WITH THIS SYSTEM BEGINNING FRIDAY NIGHT INTO SATURDAY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... A STRATOCUMULUS DECK AT 3-4KFT WILL PULL NORTHEAST THIS MORNING AS HIGH PRESSURE PUSHES ACROSS THE AREA. CLEAR SKIES CAN BE EXPECTED ACROSS THE TERMINALS BY 15Z. ASIDE FROM BRIEF MVFR CEILINGS INITIALLY AT KDUJ/KFKL, VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD. WESTERLY WINDS AT 10KTS WILL SHIFT TO MORE SOUTHERLY THIS AFTERNOON. OUTLOOK...MONDAY THROUGH THURSDAY... HIGH PRESSURE WILL ALLOW FOR VFR CONDITIONS TO CONTINUE INTO TUESDAY EVENING. RESTRICTIONS WILL THEN BE POSSIBLE AS RAIN SHOWERS PUSH INTO THE AREA TUESDAY NIGHT INTO WEDNESDAY. LINGERING RESTRICTIONS CAN BE EXPECTED ON THURSDAY WITH SCATTERED RAIN AND SNOW SHOWERS POSSIBLE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1214 AM EST SUN FEB 26 2012 .SYNOPSIS... WITH COLD WESTERLY WINDS SUBSIDING OVERNIGHT, THE REMAINING SNOW SHOWERS AND BLOWING SNOW WILL END BY DAWN. INCOMING MIDWEST HIGH PRESSURE WILL PROVIDE DRY CONDITIONS SUNDAY THROUGH TUESDAY, WITH TEMPERATURES EVENTUALLY REBOUNDING TO SEASONABLE LEVELS. && .NEAR TERM /THROUGH TODAY/... FOR MIDNIGHT UPDATE...MADE SEVERAL MINOR CHANGES. HELD ONTO POPS SLIGHTLY LONGER WITH RADAR STILL SHOWING RETURNS. UPDATED SKY GRIDS TO ACCOUNT FOR CLEARING SKIES MOVING FROM SOUTHWEST TO NORTHEAST. IN ADDITION...DROPPED OVERNIGHT LOWS A FEW DEGREES WHERE SKIES HAVE ALREADY GONE CLEAR...AS RADIATIONAL COOLING SHOULD BE ABLE TO TAKE EFFECT. PREVIOUS DISCUSSION FOLLOWS. PER RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR AND NAM MODEL OUTPUT, SNOW SHOWERS AND PATCHES OF BLOWING SNOW SHOULD END BY DAWN SUNDAY. RECENT RADAR AND SATELLITE DATA SHOWS THE REMAINING BANDS OF LAKE EFFECT SNOW SHOWERS CONTINUE TO WEAKEN. INFRARED SATELLITE IMAGERY SHOWS CLOUD TOPS HAVE BEEN WARMING, WHICH SUPPORTS NAM MODEL PROFILE PREDICTION OF A LOWERING SUBSIDENCE INVERSION AND SUBSEQUENT SHRINKING UNSTABLE SURFACE LAYER. SO EXPECT NO MORE THAN SCATTERED SNOW SHOWERS ACROSS THE NORTH AND MOUNTAINS BY MIDNIGHT, AND ONLY FLURRIES AND PARTLY CLOUDY SKIES BY 4 AM. HAVE TWEAKED TEMPERATURES FOR THE OVERNIGHT AND DAYTIME SUNDAY, CONSIDERING REFRIGERATIVE RADIATIVE EFFECTS OF FRESH SNOW COVER. HENCE HAVE LOWS TONIGHT AND HIGHS SUNDAY AS MUCH AS 3 DEGREES COLDER THAN THE PREFERRED COLDER NAM MOS. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... RECENT SREF MODEL OUTPUT SHOWS CANADIAN LOW PRESSURE PASSING EASTWARD THROUGH THE GREAT LAKES SUNDAY NIGHT, THAT WILL PUSH A WEAK COLD FRONT SOUTHWARD INTO THE UPPER OHIO VALLEY LATE SUNDAY NIGHT AND DAYTIME MONDAY. SYSTEM WILL HAVE LIMITED MOISTURE INFUSION, SO AT THIS JUNCTURE EXPECT ONLY AN INCREASE IN CLOUDS. HIGH PRESSURE,MOVING EAST FROM THE NORTHERN PLAINS, WILL MAINTAIN DRY CONDITIONS TUESDAY, AS CONSENSUS OF GFS AND NAM MOS SHOW TEMPERATURES MODERATING TO ABOVE NORMAL LEVELS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MEDIUM RANGE MODELS SHOW A CLOSED UPPER LOW AND ASSOCIATED SURFACE LOW TRACKING FROM THE CENTRAL PLAINS INTO THE LOWER GREAT LAKES/UPPER OHIO VALLEY BY WEDNESDAY NIGHT...AND OFF THE ATLANTIC COAST THURSDAY. EXPECT RAIN TO SPREAD EAST INTO THE FORECAST AREA BY LATE TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY MORNING. FORECAST DAYTIME TEMPERATURES ON WEDNESDAY SHOW A LARGE NORTH TO SOUTH RANGE AS A WARM FRONT CREEPS NORTHWARD INTO THE UPPER OHIO VALLEY. TEMPERATURES COULD PUSH WELL INTO THE 50S TO NEAR 60 IN EAST CENTRAL OHIO WHILE HOLDING IN THE 40S NORTH OF I-80. SCATTERED SHOWERS BEHIND THE SYSTEM MAY MIX WITH SNOW LATE WEDNESDAY NIGHT AND EARLY THURSDAY MAINLY ACROSS THE NORTH AS COLDER AIR MOVES IN. A BREAK FROM PRECIPITATION IS EXPECTED THURSDAY NIGHT AND EARLY FRIDAY UNDER WEAK RIDGING. THE NEXT SYSTEM WILL MOVE INTO THE GREAT LAKES AND SWING A COLD FRONT ACROSS THE REGION SATURDAY. SCATTERED SHOWERS CAN BE EXPECTED WITH THIS SYSTEM BEGINNING FRIDAY NIGHT INTO SATURDAY. && .AVIATION /05Z SUNDAY THROUGH THURSDAY/... AS SUGGESTED BY HRRR AND NAM MODEL OUTPUT, AND SUPPORTED BY RECENT SURFACE AND RADAR DATA, SNOW SHOWERS CONTINUE TO WEAKEN. SO HAVE MAINTAINED FORECAST OF STRATOCUMULUS CEILINGS AND SNOW SHOWERS, NO LOWER THAN MVFR, TIL 09Z. STRATOCUMULUS SHOULD GO SCATTERED WITH VISIBILITIES UNRESTRICTED AFTER THAT. VFR WILL CONTINUE THROUGH SUNDAY NIGHT. WEST WINDS WILL CONTINUE TO DIMINISH, WITH GUSTS NO HIGHER THAN 20 KTS INTO 06Z. WINDS WILL THEN BE 5 TO 10 KTS LATE TONIGHT AND BECOME SOUTHWESTERLY DAYTIME SUNDAY. OUTLOOK...MONDAY THROUGH THURSDAY... VFR CONDITIONS INTO TUESDAY EVENING. THEN RESTRICTIONS DUE TO A MIX OF RAIN AND SNOW SHOWERS LATE TUESDAY NIGHT AND WEDNESDAY. GUSTY WINDS POSSIBLE. COLDER THURSDAY WITH LINGERING RESTRICTIONS DUE TO SCATTERED SNOW SHOWERS. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1233 PM CST SUN FEB 26 2012 .UPDATE... BASED ON RADAR TRENDS...AREA WEBCAMS AND HRRR/WRF TRENDS...HAVE OPTED TO CANCEL THE WINTER WX ADVY FOR THE REST OF TDA. SNOWFALL AMTS HAVE BEEN QUITE LIGHT...AND THAT/S EVEN FOR THOSE SITES THAT HAD REPORTED SNOW...AND SWATH OF SNOWFALL HAS PUSHED WELL N AND E OF THE MPX CWFA. THERE MAY BE PATCHY SPOTS OF SOME BLOWING SNOW FOR THOSE ISOLD LOCATIONS THAT RECEIVED SNOW ACCUM...BUT VAST MAJORITY OF AREA RECEIVED TOO LITTLE ACCUM TO CAUSE BLOWING SNOW ISSUES. EVEN AS THE LOW PRES CENTER OVER SW MN SHIFT E...DRY AIR ENTRAINED ARND THE SYSTEM WILL MAKE FOR FLURRIES AT BEST RATHER THAN STRONGER SNOW SHOWERS OR LIGHT SNOW SO AM NOT THINKING THAT BLOWING SNOW WILL BE AN ISSUE ENOUGH TO WARRANT THE ADVY FOR THE REST OF THE DAY. NEXT ISSUE IS FOR WINDS. STRONG LLJ COMBINED WITH A VERY TIGHT PRES GRADIENT IS MAKING FOR STRONG WINDS THAT ARE SHIFTING EVENTUALLY TO W AS THE LOW PRES CENTER CROSSES SRN MN TODAY. AM KEEPING THE WIND ADVY GOING BUT HAVE OPTED TO ADD IN ANOTHER ROW OF COUNTIES IN SRN MN AS SPEEDS ARE ALREADY IN THE 20-25 KT RANGE OVER FAR SRN MN AND THESE SPEEDS LOOK TO CREEP A LITTLE FURTHER N THRU THE AFTN HOURS. && .AVIATION... /18Z TAF ISSUANCE/ LOW PRES CENTER NEAR KMVE TO CONTINUE SHIFTING E ACRS SRN MN INTO WRN WI THROUGH TONIGHT. LOW CLOUDS ASSOCIATED WITH THE LOW WILL IMPACT ALL TERMINALS...BRINGING THEM DOWN TO MVFR CIGS THAT WILL REMAIN THROUGH THE OVERNIGHT HOURS. GENERAL RANGE FOR CIGS SHOULD BE 1500-2000FT FOR KAXN-KSTC WHILE THE REMAINING SITES DROP TO 2000-2500FT. CANNOT BE RULED OUT THAT THEY DROP FURTHER BUT CONFIDENCE NOT THAT GREAT IN THAT IDEA PER MODEL GUIDANCE. KMPX RADAR DOES SHOW SOME WEAK ECHOES DRIFTING TO THE NE SO A FEW PERIODS OF FLURRIES OR SNOW SHOWERS CANNOT BE RULED OUT. THAT SAID...AM NOT EXPECTING ANYTHING TO REDUCE VSBY OUT OF VFR RANGE DURING THIS TAF PERIOD. CLOUDS WILL GRADUALLY SCOUR OUT AROUND OR SHORTLY AFTER DAYBREAK TMRW AS HIGH PRESSURE ENTERS THE REGION. STRONG GUSTY WINDS WILL PERSIST THROUGH THE REST OF TODAY THOUGH THE TRICKY PART WILL BE DIRECTIONS AS THE LOW PRES CIRCULATION SHIFTS THROUGH MN. WILL KEEP AN EYE ON OBSERVATIONS AND ADJUST TAF WINDS AS NEEDED. KMSP...MVFR CIGS TO PREVAIL THROUGH THE REST OF TDA AND MUCH OF THE OVERNIGHT. HAVE BROUGHT CIGS DOWN TO OVC020 BUT THERE IS A SMALL CHC THAT CIGS COULD DROP TO OVC017 OR SLIGHTLY LOWER FOR SOME TIME OVERNIGHT. HOWEVER...ELEVATED LOW LEVEL WINDS AND SHALLOW DRY LAYER SHOULD PREVENT CIGS FROM ENTERING LOWER-LEVEL MVFR /AND AM NOT EXPECTING IFR CIGS AT ALL/. COULD SEE A FEW PASSING FLURRIES OR BRIEF SNOW SHOWERS THIS AFTN THROUGH LATE EVENING BUT AM NOT EXPECTING ANYTHING THAT WILL REDUCE VSBYS LOWER THAN 6SM. MAIN CONCERN CONTINUES TO BE WINDS. SW WINDS WILL CONTINUE VEERING TO W THROUGH THIS AFTN AND EVE WITH SPEEDS MAINLY AROUND 15G25KT. SPEEDS WILL SETTLE DOWN OVERNIGHT THRU TMRW AFTN AS HIGH PRESSURE MOVES OVER THE AREA. OUTLOOK... /MON/...VFR. /TUE-WED/...SIGNIFICANT WINTER STORM EXPECTED. LIKELY IFR OR WORSE CONDITIONS...MAINLY TUE AFTN THRU WED MRNG. IMPROVING CONDS LATE WED. /THU/...VFR. && .PREV DISCUSSION... /ISSUED 545 AM CST SUN FEB 26 2012/ IN CONTRAST TO MOST OF THE WINTER... OUR AREA WILL BE IMPACTED BY QUITE A BIT OF SIGNIFICANT WEATHER OVER THE NEXT SEVERAL DAYS AS SEVERAL POTENT SHORTWAVES MOVE THROUGH THE REGION. A VARIETY OF WEATHER HEADLINES ARE THE RESULT OF THE ACTIVE WEATHER... WITH WINTER WEATHER AND WIND ADVISORIES RESULTING FROM THE SYSTEM MOVING THROUGH THE REGION TODAY... AND WINTER STORM WATCHES IN ASSOCIATION WITH THE STRONG SYSTEM EXPECTED TO IMPACT THE AREA DURING THE TUESDAY-WEDNESDAY TIME FRAME. THE LATEST WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSES DO A NICE JOB OF DEPICTING WHERE THE FEATURES OF INTEREST ARE AT THE CURRENT TIME. THE SHORTWAVE SEEN PUSHING THROUGH THE DAKOTAS IS THE DRIVING FORCE BEHIND THE SURFACE LOW PRESSURE IN THE SAME AREA... AND THE CHANCES FOR SNOW TODAY ACROSS PRIMARILY THE NORTHERN PART OF THE FORECAST AREA. HOWEVER... STRONG WINDS ALOFT AND MIXING BEHIND THE FRONTAL BOUNDARY SHOULD WORK TO GENERATE SOME SURFACE GUSTS ABOVE 40 MPH LATE THIS MORNING AND THIS AFTERNOON SOUTH OF THE MINNESOTA RIVER VALLEY. TWO OTHER SHORTWAVES OF INTEREST CAN ALSO BE SEEN IN THE WATER VAPOR IMAGERY... ONE DIVING SOUTH OFF THE PACIFIC NORTHWEST COAST AND A SECOND DROPPING SOUTH THROUGH BRITISH COLUMBIA. THE UPPER LEVEL PV ANOMALIES ASSOCIATED WITH THESE FEATURES ARE NICELY DEPICTED IN THE RUC ANALYSES... AND THE EXPECTATION IS FOR THESE TO COALESCE OVER THE SOUTHWEST CONUS TONIGHT AND MONDAY. WE WILL THEN WAIT FOR THIS POTENT UPPER TROUGH TO LIFT NORTHEAST FROM THE SOUTHERN ROCKIES AND WORK INTO THE PLAINS AND MID-UPPER MISSISSIPPI VALLEY TUESDAY INTO WEDNESDAY... BRINGING THE POTENTIAL FOR WIDESPREAD SIGNIFICANT SNOWFALL TO MUCH OF THE FORECAST AREA... ALONG WITH SOME MIXED PRECIPITATION. IN TERMS OF THE MODEL GUIDANCE... EVERYTHING HAS COME INTO EXCELLENT AGREEMENT WITH REGARD TO THE SYSTEM CURRENTLY OVER THE DAKOTAS WHICH WILL BE MOVING EAST ACROSS THE FORECAST AREA TODAY. THE SURFACE LOW SHOULD PASS THROUGH THE NORTHERN HALF OF THE AREA... WITH THE BULK OF THE PCPN ALONG AND NORTH OF ITS TRACK WHERE BETTER ISENTROPIC LIFT... DPVA... AND SOME UPPER DIVERGENCE ARE FOCUSED. HOWEVER... AS CAN BE SEEN IN CURRENT RADAR IMAGERY... THERE IS ENOUGH LOW LEVEL CONVERGENCE AND WARM ADVECTION AHEAD OF THE SURFACE TROUGH TO GENERATE SOME ECHOES. THUS FAR... MOST OF THAT ACTIVITY HAS REMAINED ALOFT... BUT WOULD EXPECT MORE OF IT TO REACH THE GROUND AS THE SYSTEM MOVES EAST AND THINGS SLOWLY SATURATE. THE GOING FORECAST LOOKS TO HAVE THINGS HANDLED FAIRLY WELL...SO ONLY MADE MINIMAL CHANGES... MAINLY TO NUDGE DOWN SNOWFALL TOTALS SLIGHTLY DUE TO A LONGER PERIOD OF VIRGA OCCURRING. KEPT THE ADVISORY IN PLACE AND EXTENDED IT THROUGH THE AFTERNOON WITH THE EXPECTATION THAT GUSTY WINDS BEHIND THE SURFACE LOW COULD KEEP SOME BLOWING SNOW AND REDUCED VISIBILITIES GOING UNTIL EVENING. THE GREATEST TOTALS STILL LOOK LIKE THEY SHOULD BE ALONG THE FAR NORTHERN PORTION OF THE FORECAST AREA... WHERE SOME AMOUNTS OF 3 OR 4 INCHES ARE POSSIBLE. AS MENTIONED EARLIER... THE STRONGEST WINDS ACROSS OUR FORECAST AREA TODAY LOOK TO DEVELOP SOUTH OF THE SURFACE LOW IN THE WAKE OF THE TROUGH/FRONTAL PASSAGE AS WINDS SHIFT TO THE SOUTHWEST AND WEST. WOULD EXPECT TO SEE SOME GUSTS ABOVE 40 MPH DURING THE AFTERNOON AS MIXING HELPS BRING DOWN THE 30-40KT WINDS PROGGED AROUND 925MB. WILL ISSUE A WIND ADVISORY FOR THE SOUTHWEST AND SOUTH TO ACCOUNT FOR THIS PERIOD OF GUSTY WINDS. KEPT SOME CHANCE OF SNOW THOUGH THE NIGHT OVER THE NORTH CENTRAL AND NORTHEAST CWFA AS MOISTURE AND CYCLONIC FLOW LINGER ON THE BACK SIDE OF THE SURFACE LOW... WHILE THE UPPER TROUGH IS SLOW TO PROGRESS EAST OF THE AREA. A STOUT 1035MB RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON MONDAY... BRINGING A PERIOD OF TRANQUIL WEATHER BEFORE ATTENTION IS FOCUSED ON THE SIGNIFICANT SYSTEM EXPECTED TO IMPACT THE REGION TUESDAY THROUGH WEDNESDAY. AS EXPECTED OVER THE PAST FEW DAYS... THIS NEXT SYSTEM LOOKS LIKE IT WILL BE A BIT SLOWER THAN ORIGINALLY PROGGED TO EJECT OUT OF THE SOUTHWEST CONUS... AND DOESN/T LOOK TO BRING PCPN INTO OUR AREA UNTIL PERHAPS LATE MONDAY NIGHT AND MORE LIKELY ON TUESDAY. THERE REMAINS A FAIR DEGREE OF SPREAD IN THE MODEL SOLUTIONS ON THE TRACK OF THE SURFACE LOW... BUT MOST OF THE GUIDANCE HAS TRENDED TOWARD THE IDEA OFFERED BY THE ECMWF FOR SEVERAL RUNS. THIS SUGGESTS THE NEGATIVELY TILTED UPPER WAVE WILL LIFT OUT INTO THE CENTRAL PLAINS BY TUESDAY NIGHT... DEEPENING THE SURFACE LOW OVER NEBRASKA AS IT DOES SO. THEN THE SYSTEM LOOKS TO BECOME VERTICALLY STACKED AND OCCLUDE NEAR NORTHWEST IOWA LATE TUESDAY NIGHT. IT IS AT THIS POINT... WHEN THE SYSTEM IS OCCLUDING AND THE UPPER WAVE IS BEGINNING TO RUN INTO CONFLUENT FLOW OVER THE NORTHERN GREAT LAKES... THAT IT SHOULD START TO TRACK EASTWARD AND SLOWLY WEAKEN WITH TIME. THERE REMAIN SOME DIFFERENCES IN HOW THINGS WILL EVOLVE DURING THIS STAGE... BUT THE GFS... ECMWF... AND FIM CONSENSUS WOULD SUGGEST A SURFACE LOW TRACK NEAR OR A BIT SOUTH OF THE IOWA BORDER. A PROMINENT TROWAL FEATURE IS SUGGESTED BY THE THETA-E SURFACES WITH THIS SYSTEM... WITH THAT TROWAL WRAPPING INTO SOUTHERN MINNESOTA AND HELPING TO FOCUS THE HEAVIEST PCPN ACROSS CENTRAL MINNESOTA. WARM AIR SURGING NORTH AND WRAPPING INTO THE SYSTEM LOOKS TO BRING AN ELEVATED WARM LAYER INTO THE SOUTHERN PART OF THE STATE... WITH THE WARM NOSE LOOKING LIKE IT WILL BE LOCATED AROUND 825MB. WITH MINIMAL PRE-EXISTING COLD AIR IN PLACE... NEAR SURFACE TEMPERATURES WILL ALSO BE RELATIVELY WARM WITH THIS SYSTEM... FURTHER COMPLICATING PCPN-TYPE ISSUES. AT THIS POINT... THE FULL SOUNDING PROFILE LOOKS TO REMAIN BELOW FREEZING FROM AROUND THE TWIN CITIES NORTHWARD... WITH THE WARM LAYER MAX TEMPERATURE INCREASING AS YOU HEAD SOUTH... AND POSSIBLY AS WARM AS +2C NEAR THE IOWA BORDER. SURFACE TEMPERATURES MAY ALSO GET INTO THE 30-35F RANGE OVER THE SOUTHERN PART OF THE AREA. AT THIS POINT... THIS POINTS TOWARD AN ALL SNOW EVENT NORTH OF THE TWIN CITIES... THE POSSIBILITY OF SOME SLEET AS FAR NORTH AS THE TWIN CITIES METRO... AND SLEET AND SOME RAIN POSSIBLE AS YOU GET TOWARD THE IOWA BORDER. THERE COULD ALSO BE A NARROW ZONE OF FREEZING RAIN... BUT WITH SUCH MARGINALLY FREEZING SURFACE TEMPERATURES... AM NOT TOO CONCERNED ABOUT THAT POTENTIAL AT THIS POINT. FORECAST PCPN TOTALS FROM THE GFS... ECMWF... FIM... AND GFS ENSEMBLES SUGGEST AMOUNTS BETWEEN 1 AND 2 INCHES ACROSS A GOOD PART OF THE CENTRAL AND NORTHERN CWFA... WHICH COULD TRANSLATE TO SNOW AMOUNTS WELL IN EXCESS OF A FOOT. THESE SIGNIFICANT PCPN AMOUNTS LOOK REASONABLE GIVEN STRONG FORCING AND ABUNDANT MOISTURE THAT IS SUGGESTED BY ALL OF THE GUIDANCE. MIXING RATIOS IN THE MID-LEVEL ISENTROPIC LIFT ZONE WILL BE IN THE 3-4 G/KG RANGE... WHICH WOULD SUGGEST AT LEAST 6-8 INCH SNOW AMOUNTS PER 12 HOURS... AND MUCH OF THE AREA WILL SEE SNOWFALL FOR 18-24 HOURS. FRONTOGENESIS LOOKS TO BE MAXIMIZED IN THE 800-700MB LAYER... WITH A FAIRLY DEEP LAYER OF EPV PROGGED JUST ABOVE THAT... OWING TO SOME UPRIGHT INSTABILITY OVER THE SOUTHERN PART OF THE AREA... AND SYMMETRIC INSTABILITY FARTHER NORTH. THERE ALSO APPEARS TO BE A GOOD WINDOW OF 6+ HOURS WHEN THE FRONTOGENETICAL CIRCULATION IS CO-LOCATED WITH THE UPPER JET INDUCED CIRCULATION AS WE FIND OURSELVES IN A NICE COUPLED JET REGION FOR A TIME. GIVEN THIS POTENTIAL FOR SIGNIFICANT SNOWFALL... AS WELL AS THE POSSIBILITY OF SLEET AND GUSTY WINDS... A WINTER STORM WATCH WILL BE ISSUED FOR ALL OF THE MINNESOTA PORTION OF THE CWFA. THE WATCH MAY VERY WELL BE EXTENDED FARTHER EAST LATER TODAY IF CONDITIONS STILL LOOK FAVORABLE AS THINGS MOVE INTO THAT AREA. A QUICK LOOK AT THE CIPS ANALOGS SHOW A NICE MATCH IN THE MEAN SNOWFALL SWATH FROM THE TOP ANALOGS IN TERMS OF POSITION AS WELL AS MAGNITUDE TO SOME DEGREE... WITH HIGH PROBABILITIES OF GREATER THAN 8 INCHES... AS WELL AS SOME PROBABILITIES FOR 12+ AND 18+ AMOUNTS OVER PORTIONS OF THE NORTH HALF OF THE CWFA. WITH THIS SYSTEM STILL A FEW DAYS AWAY... THERE IS OBVIOUSLY A GOOD DEAL OF UNCERTAINTY... EVEN WITH WHAT WOULD SEEM TO BE FAIRLY GOOD MODEL CONSENSUS AT THIS POINT. THE MODEL CONSENSUS IS WHAT IS HELPING TO DRIVE THE DECISION TO ISSUE A WINTER STORM WATCH... BUT UNTIL THE UPPER WAVES DROP INTO THE WESTERN US BEGIN TO WORK EASTWARD... WE COULD STILL SEE THE DETAILS OF THE FORECAST CHANGE QUITE A BIT. SHOULD THE SYSTEM COME MUCH FARTHER NORTH IT WOULD MEAN MUCH MORE IN THE WAY OF SLEET AND RAIN FOR THE SOUTHERN HALF OF THE AREA... AND ANY SOUTHWARD SHIFT IN THE TRACK WOULD BRING THE AXIS OF HEAVIEST SNOWFALL TO THE TWIN CITIES AREA AND POINTS SOUTH. BUT... AT THIS POINT IN TIME THERE IS THE POTENTIAL FOR WIDESPREAD SNOW AMOUNTS IN EXCESS OF 8 INCHES WITH TOTALS WELL IN EXCESS OF A FOOT CERTAINLY POSSIBLE. NEEDLESS TO SAY... THIS SYSTEM WILL NEED TO BE MONITORED CLOSELY OVER THE COMING TWO DAYS. THE BULK OF THE ACTION LOOKS TO OCCUR FROM LATE TUESDAY AFTERNOON THROUGH MONDAY MORNING. A WEAK RIDGE OF HIGH PRESSURE WILL ARRIVE IN THE WAKE OF THE TUESDAY-WEDNESDAY SYSTEM... BRINGING DRY WEATHER FOR MOST OF WEDNESDAY NIGHT AND THURSDAY. UNLIKE WITH MOST SIGNIFICANT WINTER STORMS... WE SHOULDN/T SEE A HUGE DROP IN TEMPERATURES BEHIND THE TUESDAY- WEDNESDAY STORM... ALTHOUGH LOWS WILL DEFINITELY HAVE AN OPPORTUNITY TO BE COLDER GIVEN THE CHANCE FOR BETTER RADIATIONAL COOLING. A CHANCE FOR SOME SNOW STILL LOOKS POSSIBLE ON FRIDAY... PERHAPS LINGERING INTO SATURDAY... AS A SHORTWAVE AND ATTENDANT SURFACE LOW MOVE EAST ALONG THE US/CANADIAN BORDER. THE IS ALSO A SOUTHERN STREAM WAVE THAT IS EXPECTED TO LIFT NORTHEAST FROM THE SOUTHWEST CONUS DURING THE SAME TIME PERIOD... BUT AT THIS POINT IN TIME MOST OF THE GUIDANCE SUGGESTS ITS MAIN IMPACTS WILL OCCUR SOUTHEAST OF OUR AREA. HOWEVER... SHOULD THE NORTHERN WAVE ARRIVE MORE SLOWLY AND/OR DIG FARTHER SOUTH... THEN WE COULD SEE A MORE INTERESTING SCENARIO UNFOLD FOR OUR AREA DURING THAT TIME FRAME. FOR NOW... SIMPLY MAINTAINED POPS ON FRIDAY AND LINGERED THEM INTO SATURDAY OVER THE EASTERN PORTION OF THE AREA. TEMPERATURES LOOK LIKE THEY SHOULD BE SLIGHTLY COOLER THAN NORMAL TO ROUND OUT THE WEEK. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR BLUE EARTH-BROWN- CHIPPEWA-FARIBAULT-FREEBORN-GOODHUE-LAC QUI PARLE-LE SUEUR- MARTIN-NICOLLET-REDWOOD-RENVILLE-RICE-SIBLEY-STEELE-WASECA- WATONWAN-YELLOW MEDICINE. WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR ANOKA-BENTON-BLUE EARTH-BROWN-CARVER-CHIPPEWA- CHISAGO-DAKOTA-DOUGLAS-FARIBAULT-FREEBORN-GOODHUE-HENNEPIN- ISANTI-KANABEC-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN- MCLEOD-MEEKER-MILLE LACS-MORRISON-NICOLLET-POPE-RAMSEY- REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE- STEVENS-SWIFT-TODD-WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE. WI...NONE. && $$ JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
958 AM CST SUN FEB 26 2012 .UPDATE... BASED ON RADAR TRENDS...AREA WEBCAMS AND HRRR/WRF TRENDS...HAVE OPTED TO CANCEL THE WINTER WX ADVY FOR THE REST OF TDA. SNOWFALL AMTS HAVE BEEN QUITE LIGHT...AND THAT/S EVEN FOR THOSE SITES THAT HAD REPORTED SNOW...AND SWATH OF SNOWFALL HAS PUSHED WELL N AND E OF THE MPX CWFA. THERE MAY BE PATCHY SPOTS OF SOME BLOWING SNOW FOR THOSE ISOLD LOCATIONS THAT RECEIVED SNOW ACCUM...BUT VAST MAJORITY OF AREA RECEIVED TOO LITTLE ACCUM TO CAUSE BLOWING SNOW ISSUES. EVEN AS THE LOW PRES CENTER OVER SW MN SHIFT E...DRY AIR ENTRAINED ARND THE SYSTEM WILL MAKE FOR FLURRIES AT BEST RATHER THAN STRONGER SNOW SHOWERS OR LIGHT SNOW SO AM NOT THINKING THAT BLOWING SNOW WILL BE AN ISSUE ENOUGH TO WARRANT THE ADVY FOR THE REST OF THE DAY. NEXT ISSUE IS FOR WINDS. STRONG LLJ COMBINED WITH A VERY TIGHT PRES GRADIENT IS MAKING FOR STRONG WINDS THAT ARE SHIFTING EVENTUALLY TO W AS THE LOW PRES CENTER CROSSES SRN MN TODAY. AM KEEPING THE WIND ADVY GOING BUT HAVE OPTED TO ADD IN ANOTHER ROW OF COUNTIES IN SRN MN AS SPEEDS ARE ALREADY IN THE 20-25 KT RANGE OVER FAR SRN MN AND THESE SPEEDS LOOK TO CREEP A LITTLE FURTHER N THRU THE AFTN HOURS. && .AVIATION... /12Z TAF ISSUANCE/ A LOW PRESSURE SYSTEM WILL MOVE OVER CENTRAL MN TODAY. SNOW WILL CONTINUE TO DEVELOP OVER CENTRAL MN AHEAD OF THE LOW. A DRY EAST-SOUTHEASTERLY AIRFLOW IN THE LOW LEVELS CONTINUE TO DELAY THE ONSET OF THE PRECIPITATION OVER THE AREA. CEILING HEIGHTS SO FAR REMAIN ABOVE 5000 FEET AGL MOST TAF SITES IN OUR AREA THIS MORNING. EXPECT MARGINAL VFR CONDITIONS TO DEVELOP OVER THE FORECAST AREA...ESPECIALLY LATER TODAY AND TONIGHT. GUSTY SOUTHEAST WINDS OF 20 TO 40 KNOTS WILL GRADUALLY SHIFT TO NORTHWEST OVER WESTERN AND SOUTH CENTRAL MN DURING THE AFTERNOON. TONIGHT...SKIES WILL REMAIN OVERCAST WITH CEILING BETWEEN 2000-3000 FEET AGL. KMSP...A FEW SNOW FLURRIES OR SPRINKLES DEVELOPING LATER THIS MORNING. EXPECT VFR CONDITIONS TO PREVAIL THROUGH THIS EVENING WITH CEILING HEIGHTS LOWERING AROUND 3000 FEET BY MIDNIGHT. SOUTHEAST WINDS 15 TO 25 KNOTS SHIFTING TO SOUTHWEST-WEST LATER THIS AFTERNOON. OUTLOOK... /MON/...VFR. /TUE-WED/...SIGNIFICANT WINTER STORM EXPECTED. LIKELY IFR OR WORSE CONDITIONS...MAINLY TUE AFTN THRU WED MRNG. IMPROVING CONDS LATE WED. /THU/...VFR. && .PREV DISCUSSION... /ISSUED 545 AM CST SUN FEB 26 2012/ IN CONTRAST TO MOST OF THE WINTER... OUR AREA WILL BE IMPACTED BY QUITE A BIT OF SIGNIFICANT WEATHER OVER THE NEXT SEVERAL DAYS AS SEVERAL POTENT SHORTWAVES MOVE THROUGH THE REGION. A VARIETY OF WEATHER HEADLINES ARE THE RESULT OF THE ACTIVE WEATHER... WITH WINTER WEATHER AND WIND ADVISORIES RESULTING FROM THE SYSTEM MOVING THROUGH THE REGION TODAY... AND WINTER STORM WATCHES IN ASSOCIATION WITH THE STRONG SYSTEM EXPECTED TO IMPACT THE AREA DURING THE TUESDAY-WEDNESDAY TIME FRAME. THE LATEST WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSES DO A NICE JOB OF DEPICTING WHERE THE FEATURES OF INTEREST ARE AT THE CURRENT TIME. THE SHORTWAVE SEEN PUSHING THROUGH THE DAKOTAS IS THE DRIVING FORCE BEHIND THE SURFACE LOW PRESSURE IN THE SAME AREA... AND THE CHANCES FOR SNOW TODAY ACROSS PRIMARILY THE NORTHERN PART OF THE FORECAST AREA. HOWEVER... STRONG WINDS ALOFT AND MIXING BEHIND THE FRONTAL BOUNDARY SHOULD WORK TO GENERATE SOME SURFACE GUSTS ABOVE 40 MPH LATE THIS MORNING AND THIS AFTERNOON SOUTH OF THE MINNESOTA RIVER VALLEY. TWO OTHER SHORTWAVES OF INTEREST CAN ALSO BE SEEN IN THE WATER VAPOR IMAGERY... ONE DIVING SOUTH OFF THE PACIFIC NORTHWEST COAST AND A SECOND DROPPING SOUTH THROUGH BRITISH COLUMBIA. THE UPPER LEVEL PV ANOMALIES ASSOCIATED WITH THESE FEATURES ARE NICELY DEPICTED IN THE RUC ANALYSES... AND THE EXPECTATION IS FOR THESE TO COALESCE OVER THE SOUTHWEST CONUS TONIGHT AND MONDAY. WE WILL THEN WAIT FOR THIS POTENT UPPER TROUGH TO LIFT NORTHEAST FROM THE SOUTHERN ROCKIES AND WORK INTO THE PLAINS AND MID-UPPER MISSISSIPPI VALLEY TUESDAY INTO WEDNESDAY... BRINGING THE POTENTIAL FOR WIDESPREAD SIGNIFICANT SNOWFALL TO MUCH OF THE FORECAST AREA... ALONG WITH SOME MIXED PRECIPITATION. IN TERMS OF THE MODEL GUIDANCE... EVERYTHING HAS COME INTO EXCELLENT AGREEMENT WITH REGARD TO THE SYSTEM CURRENTLY OVER THE DAKOTAS WHICH WILL BE MOVING EAST ACROSS THE FORECAST AREA TODAY. THE SURFACE LOW SHOULD PASS THROUGH THE NORTHERN HALF OF THE AREA... WITH THE BULK OF THE PCPN ALONG AND NORTH OF ITS TRACK WHERE BETTER ISENTROPIC LIFT... DPVA... AND SOME UPPER DIVERGENCE ARE FOCUSED. HOWEVER... AS CAN BE SEEN IN CURRENT RADAR IMAGERY... THERE IS ENOUGH LOW LEVEL CONVERGENCE AND WARM ADVECTION AHEAD OF THE SURFACE TROUGH TO GENERATE SOME ECHOES. THUS FAR... MOST OF THAT ACTIVITY HAS REMAINED ALOFT... BUT WOULD EXPECT MORE OF IT TO REACH THE GROUND AS THE SYSTEM MOVES EAST AND THINGS SLOWLY SATURATE. THE GOING FORECAST LOOKS TO HAVE THINGS HANDLED FAIRLY WELL...SO ONLY MADE MINIMAL CHANGES... MAINLY TO NUDGE DOWN SNOWFALL TOTALS SLIGHTLY DUE TO A LONGER PERIOD OF VIRGA OCCURRING. KEPT THE ADVISORY IN PLACE AND EXTENDED IT THROUGH THE AFTERNOON WITH THE EXPECTATION THAT GUSTY WINDS BEHIND THE SURFACE LOW COULD KEEP SOME BLOWING SNOW AND REDUCED VISIBILITIES GOING UNTIL EVENING. THE GREATEST TOTALS STILL LOOK LIKE THEY SHOULD BE ALONG THE FAR NORTHERN PORTION OF THE FORECAST AREA... WHERE SOME AMOUNTS OF 3 OR 4 INCHES ARE POSSIBLE. AS MENTIONED EARLIER... THE STRONGEST WINDS ACROSS OUR FORECAST AREA TODAY LOOK TO DEVELOP SOUTH OF THE SURFACE LOW IN THE WAKE OF THE TROUGH/FRONTAL PASSAGE AS WINDS SHIFT TO THE SOUTHWEST AND WEST. WOULD EXPECT TO SEE SOME GUSTS ABOVE 40 MPH DURING THE AFTERNOON AS MIXING HELPS BRING DOWN THE 30-40KT WINDS PROGGED AROUND 925MB. WILL ISSUE A WIND ADVISORY FOR THE SOUTHWEST AND SOUTH TO ACCOUNT FOR THIS PERIOD OF GUSTY WINDS. KEPT SOME CHANCE OF SNOW THOUGH THE NIGHT OVER THE NORTH CENTRAL AND NORTHEAST CWFA AS MOISTURE AND CYCLONIC FLOW LINGER ON THE BACK SIDE OF THE SURFACE LOW... WHILE THE UPPER TROUGH IS SLOW TO PROGRESS EAST OF THE AREA. A STOUT 1035MB RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON MONDAY... BRINGING A PERIOD OF TRANQUIL WEATHER BEFORE ATTENTION IS FOCUSED ON THE SIGNIFICANT SYSTEM EXPECTED TO IMPACT THE REGION TUESDAY THROUGH WEDNESDAY. AS EXPECTED OVER THE PAST FEW DAYS... THIS NEXT SYSTEM LOOKS LIKE IT WILL BE A BIT SLOWER THAN ORIGINALLY PROGGED TO EJECT OUT OF THE SOUTHWEST CONUS... AND DOESN/T LOOK TO BRING PCPN INTO OUR AREA UNTIL PERHAPS LATE MONDAY NIGHT AND MORE LIKELY ON TUESDAY. THERE REMAINS A FAIR DEGREE OF SPREAD IN THE MODEL SOLUTIONS ON THE TRACK OF THE SURFACE LOW... BUT MOST OF THE GUIDANCE HAS TRENDED TOWARD THE IDEA OFFERED BY THE ECMWF FOR SEVERAL RUNS. THIS SUGGESTS THE NEGATIVELY TILTED UPPER WAVE WILL LIFT OUT INTO THE CENTRAL PLAINS BY TUESDAY NIGHT... DEEPENING THE SURFACE LOW OVER NEBRASKA AS IT DOES SO. THEN THE SYSTEM LOOKS TO BECOME VERTICALLY STACKED AND OCCLUDE NEAR NORTHWEST IOWA LATE TUESDAY NIGHT. IT IS AT THIS POINT... WHEN THE SYSTEM IS OCCLUDING AND THE UPPER WAVE IS BEGINNING TO RUN INTO CONFLUENT FLOW OVER THE NORTHERN GREAT LAKES... THAT IT SHOULD START TO TRACK EASTWARD AND SLOWLY WEAKEN WITH TIME. THERE REMAIN SOME DIFFERENCES IN HOW THINGS WILL EVOLVE DURING THIS STAGE... BUT THE GFS... ECMWF... AND FIM CONSENSUS WOULD SUGGEST A SURFACE LOW TRACK NEAR OR A BIT SOUTH OF THE IOWA BORDER. A PROMINENT TROWAL FEATURE IS SUGGESTED BY THE THETA-E SURFACES WITH THIS SYSTEM... WITH THAT TROWAL WRAPPING INTO SOUTHERN MINNESOTA AND HELPING TO FOCUS THE HEAVIEST PCPN ACROSS CENTRAL MINNESOTA. WARM AIR SURGING NORTH AND WRAPPING INTO THE SYSTEM LOOKS TO BRING AN ELEVATED WARM LAYER INTO THE SOUTHERN PART OF THE STATE... WITH THE WARM NOSE LOOKING LIKE IT WILL BE LOCATED AROUND 825MB. WITH MINIMAL PRE-EXISTING COLD AIR IN PLACE... NEAR SURFACE TEMPERATURES WILL ALSO BE RELATIVELY WARM WITH THIS SYSTEM... FURTHER COMPLICATING PCPN-TYPE ISSUES. AT THIS POINT... THE FULL SOUNDING PROFILE LOOKS TO REMAIN BELOW FREEZING FROM AROUND THE TWIN CITIES NORTHWARD... WITH THE WARM LAYER MAX TEMPERATURE INCREASING AS YOU HEAD SOUTH... AND POSSIBLY AS WARM AS +2C NEAR THE IOWA BORDER. SURFACE TEMPERATURES MAY ALSO GET INTO THE 30-35F RANGE OVER THE SOUTHERN PART OF THE AREA. AT THIS POINT... THIS POINTS TOWARD AN ALL SNOW EVENT NORTH OF THE TWIN CITIES... THE POSSIBILITY OF SOME SLEET AS FAR NORTH AS THE TWIN CITIES METRO... AND SLEET AND SOME RAIN POSSIBLE AS YOU GET TOWARD THE IOWA BORDER. THERE COULD ALSO BE A NARROW ZONE OF FREEZING RAIN... BUT WITH SUCH MARGINALLY FREEZING SURFACE TEMPERATURES... AM NOT TOO CONCERNED ABOUT THAT POTENTIAL AT THIS POINT. FORECAST PCPN TOTALS FROM THE GFS... ECMWF... FIM... AND GFS ENSEMBLES SUGGEST AMOUNTS BETWEEN 1 AND 2 INCHES ACROSS A GOOD PART OF THE CENTRAL AND NORTHERN CWFA... WHICH COULD TRANSLATE TO SNOW AMOUNTS WELL IN EXCESS OF A FOOT. THESE SIGNIFICANT PCPN AMOUNTS LOOK REASONABLE GIVEN STRONG FORCING AND ABUNDANT MOISTURE THAT IS SUGGESTED BY ALL OF THE GUIDANCE. MIXING RATIOS IN THE MID-LEVEL ISENTROPIC LIFT ZONE WILL BE IN THE 3-4 G/KG RANGE... WHICH WOULD SUGGEST AT LEAST 6-8 INCH SNOW AMOUNTS PER 12 HOURS... AND MUCH OF THE AREA WILL SEE SNOWFALL FOR 18-24 HOURS. FRONTOGENESIS LOOKS TO BE MAXIMIZED IN THE 800-700MB LAYER... WITH A FAIRLY DEEP LAYER OF EPV PROGGED JUST ABOVE THAT... OWING TO SOME UPRIGHT INSTABILITY OVER THE SOUTHERN PART OF THE AREA... AND SYMMETRIC INSTABILITY FARTHER NORTH. THERE ALSO APPEARS TO BE A GOOD WINDOW OF 6+ HOURS WHEN THE FRONTOGENETICAL CIRCULATION IS CO-LOCATED WITH THE UPPER JET INDUCED CIRCULATION AS WE FIND OURSELVES IN A NICE COUPLED JET REGION FOR A TIME. GIVEN THIS POTENTIAL FOR SIGNIFICANT SNOWFALL... AS WELL AS THE POSSIBILITY OF SLEET AND GUSTY WINDS... A WINTER STORM WATCH WILL BE ISSUED FOR ALL OF THE MINNESOTA PORTION OF THE CWFA. THE WATCH MAY VERY WELL BE EXTENDED FARTHER EAST LATER TODAY IF CONDITIONS STILL LOOK FAVORABLE AS THINGS MOVE INTO THAT AREA. A QUICK LOOK AT THE CIPS ANALOGS SHOW A NICE MATCH IN THE MEAN SNOWFALL SWATH FROM THE TOP ANALOGS IN TERMS OF POSITION AS WELL AS MAGNITUDE TO SOME DEGREE... WITH HIGH PROBABILITIES OF GREATER THAN 8 INCHES... AS WELL AS SOME PROBABILITIES FOR 12+ AND 18+ AMOUNTS OVER PORTIONS OF THE NORTH HALF OF THE CWFA. WITH THIS SYSTEM STILL A FEW DAYS AWAY... THERE IS OBVIOUSLY A GOOD DEAL OF UNCERTAINTY... EVEN WITH WHAT WOULD SEEM TO BE FAIRLY GOOD MODEL CONSENSUS AT THIS POINT. THE MODEL CONSENSUS IS WHAT IS HELPING TO DRIVE THE DECISION TO ISSUE A WINTER STORM WATCH... BUT UNTIL THE UPPER WAVES DROP INTO THE WESTERN US BEGIN TO WORK EASTWARD... WE COULD STILL SEE THE DETAILS OF THE FORECAST CHANGE QUITE A BIT. SHOULD THE SYSTEM COME MUCH FARTHER NORTH IT WOULD MEAN MUCH MORE IN THE WAY OF SLEET AND RAIN FOR THE SOUTHERN HALF OF THE AREA... AND ANY SOUTHWARD SHIFT IN THE TRACK WOULD BRING THE AXIS OF HEAVIEST SNOWFALL TO THE TWIN CITIES AREA AND POINTS SOUTH. BUT... AT THIS POINT IN TIME THERE IS THE POTENTIAL FOR WIDESPREAD SNOW AMOUNTS IN EXCESS OF 8 INCHES WITH TOTALS WELL IN EXCESS OF A FOOT CERTAINLY POSSIBLE. NEEDLESS TO SAY... THIS SYSTEM WILL NEED TO BE MONITORED CLOSELY OVER THE COMING TWO DAYS. THE BULK OF THE ACTION LOOKS TO OCCUR FROM LATE TUESDAY AFTERNOON THROUGH MONDAY MORNING. A WEAK RIDGE OF HIGH PRESSURE WILL ARRIVE IN THE WAKE OF THE TUESDAY-WEDNESDAY SYSTEM... BRINGING DRY WEATHER FOR MOST OF WEDNESDAY NIGHT AND THURSDAY. UNLIKE WITH MOST SIGNIFICANT WINTER STORMS... WE SHOULDN/T SEE A HUGE DROP IN TEMPERATURES BEHIND THE TUESDAY- WEDNESDAY STORM... ALTHOUGH LOWS WILL DEFINITELY HAVE AN OPPORTUNITY TO BE COLDER GIVEN THE CHANCE FOR BETTER RADIATIONAL COOLING. A CHANCE FOR SOME SNOW STILL LOOKS POSSIBLE ON FRIDAY... PERHAPS LINGERING INTO SATURDAY... AS A SHORTWAVE AND ATTENDANT SURFACE LOW MOVE EAST ALONG THE US/CANADIAN BORDER. THE IS ALSO A SOUTHERN STREAM WAVE THAT IS EXPECTED TO LIFT NORTHEAST FROM THE SOUTHWEST CONUS DURING THE SAME TIME PERIOD... BUT AT THIS POINT IN TIME MOST OF THE GUIDANCE SUGGESTS ITS MAIN IMPACTS WILL OCCUR SOUTHEAST OF OUR AREA. HOWEVER... SHOULD THE NORTHERN WAVE ARRIVE MORE SLOWLY AND/OR DIG FARTHER SOUTH... THEN WE COULD SEE A MORE INTERESTING SCENARIO UNFOLD FOR OUR AREA DURING THAT TIME FRAME. FOR NOW... SIMPLY MAINTAINED POPS ON FRIDAY AND LINGERED THEM INTO SATURDAY OVER THE EASTERN PORTION OF THE AREA. TEMPERATURES LOOK LIKE THEY SHOULD BE SLIGHTLY COOLER THAN NORMAL TO ROUND OUT THE WEEK. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR BLUE EARTH-BROWN- CHIPPEWA-FARIBAULT-FREEBORN-GOODHUE-LAC QUI PARLE-LE SUEUR- MARTIN-NICOLLET-REDWOOD-RENVILLE-RICE-SIBLEY-STEELE-WASECA- WATONWAN-YELLOW MEDICINE. WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR ANOKA-BENTON-BLUE EARTH-BROWN-CARVER-CHIPPEWA- CHISAGO-DAKOTA-DOUGLAS-FARIBAULT-FREEBORN-GOODHUE-HENNEPIN- ISANTI-KANABEC-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN- MCLEOD-MEEKER-MILLE LACS-MORRISON-NICOLLET-POPE-RAMSEY- REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE- STEVENS-SWIFT-TODD-WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE. WI...NONE. && $$ JPC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
545 AM CST SUN FEB 26 2012 .DISCUSSION.../ISSUED AT 301 AM CST SUN FEB 26 2012/ IN CONTRAST TO MOST OF THE WINTER... OUR AREA WILL BE IMPACTED BY QUITE A BIT OF SIGNIFICANT WEATHER OVER THE NEXT SEVERAL DAYS AS SEVERAL POTENT SHORTWAVES MOVE THROUGH THE REGION. A VARIETY OF WEATHER HEADLINES ARE THE RESULT OF THE ACTIVE WEATHER... WITH WINTER WEATHER AND WIND ADVISORIES RESULTING FROM THE SYSTEM MOVING THROUGH THE REGION TODAY... AND WINTER STORM WATCHES IN ASSOCIATION WITH THE STRONG SYSTEM EXPECTED TO IMPACT THE AREA DURING THE TUESDAY-WEDNESDAY TIME FRAME. THE LATEST WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSES DO A NICE JOB OF DEPICTING WHERE THE FEATURES OF INTEREST ARE AT THE CURRENT TIME. THE SHORTWAVE SEEN PUSHING THROUGH THE DAKOTAS IS THE DRIVING FORCE BEHIND THE SURFACE LOW PRESSURE IN THE SAME AREA... AND THE CHANCES FOR SNOW TODAY ACROSS PRIMARILY THE NORTHERN PART OF THE FORECAST AREA. HOWEVER... STRONG WINDS ALOFT AND MIXING BEHIND THE FRONTAL BOUNDARY SHOULD WORK TO GENERATE SOME SURFACE GUSTS ABOVE 40 MPH LATE THIS MORNING AND THIS AFTERNOON SOUTH OF THE MINNESOTA RIVER VALLEY. TWO OTHER SHORTWAVES OF INTEREST CAN ALSO BE SEEN IN THE WATER VAPOR IMAGERY... ONE DIVING SOUTH OFF THE PACIFIC NORTHWEST COAST AND A SECOND DROPPING SOUTH THROUGH BRITISH COLUMBIA. THE UPPER LEVEL PV ANOMALIES ASSOCIATED WITH THESE FEATURES ARE NICELY DEPICTED IN THE RUC ANALYSES... AND THE EXPECTATION IS FOR THESE TO COALESCE OVER THE SOUTHWEST CONUS TONIGHT AND MONDAY. WE WILL THEN WAIT FOR THIS POTENT UPPER TROUGH TO LIFT NORTHEAST FROM THE SOUTHERN ROCKIES AND WORK INTO THE PLAINS AND MID-UPPER MISSISSIPPI VALLEY TUESDAY INTO WEDNESDAY... BRINGING THE POTENTIAL FOR WIDESPREAD SIGNIFICANT SNOWFALL TO MUCH OF THE FORECAST AREA... ALONG WITH SOME MIXED PRECIPITATION. IN TERMS OF THE MODEL GUIDANCE... EVERYTHING HAS COME INTO EXCELLENT AGREEMENT WITH REGARD TO THE SYSTEM CURRENTLY OVER THE DAKOTAS WHICH WILL BE MOVING EAST ACROSS THE FORECAST AREA TODAY. THE SURFACE LOW SHOULD PASS THROUGH THE NORTHERN HALF OF THE AREA... WITH THE BULK OF THE PCPN ALONG AND NORTH OF ITS TRACK WHERE BETTER ISENTROPIC LIFT... DPVA... AND SOME UPPER DIVERGENCE ARE FOCUSED. HOWEVER... AS CAN BE SEEN IN CURRENT RADAR IMAGERY... THERE IS ENOUGH LOW LEVEL CONVERGENCE AND WARM ADVECTION AHEAD OF THE SURFACE TROUGH TO GENERATE SOME ECHOES. THUS FAR... MOST OF THAT ACTIVITY HAS REMAINED ALOFT... BUT WOULD EXPECT MORE OF IT TO REACH THE GROUND AS THE SYSTEM MOVES EAST AND THINGS SLOWLY SATURATE. THE GOING FORECAST LOOKS TO HAVE THINGS HANDLED FAIRLY WELL...SO ONLY MADE MINIMAL CHANGES... MAINLY TO NUDGE DOWN SNOWFALL TOTALS SLIGHTLY DUE TO A LONGER PERIOD OF VIRGA OCCURRING. KEPT THE ADVISORY IN PLACE AND EXTENDED IT THROUGH THE AFTERNOON WITH THE EXPECTATION THAT GUSTY WINDS BEHIND THE SURFACE LOW COULD KEEP SOME BLOWING SNOW AND REDUCED VISIBILITIES GOING UNTIL EVENING. THE GREATEST TOTALS STILL LOOK LIKE THEY SHOULD BE ALONG THE FAR NORTHERN PORTION OF THE FORECAST AREA... WHERE SOME AMOUNTS OF 3 OR 4 INCHES ARE POSSIBLE. AS MENTIONED EARLIER... THE STRONGEST WINDS ACROSS OUR FORECAST AREA TODAY LOOK TO DEVELOP SOUTH OF THE SURFACE LOW IN THE WAKE OF THE TROUGH/FRONTAL PASSAGE AS WINDS SHIFT TO THE SOUTHWEST AND WEST. WOULD EXPECT TO SEE SOME GUSTS ABOVE 40 MPH DURING THE AFTERNOON AS MIXING HELPS BRING DOWN THE 30-40KT WINDS PROGGED AROUND 925MB. WILL ISSUE A WIND ADVISORY FOR THE SOUTHWEST AND SOUTH TO ACCOUNT FOR THIS PERIOD OF GUSTY WINDS. KEPT SOME CHANCE OF SNOW THOUGH THE NIGHT OVER THE NORTH CENTRAL AND NORTHEAST CWFA AS MOISTURE AND CYCLONIC FLOW LINGER ON THE BACK SIDE OF THE SURFACE LOW... WHILE THE UPPER TROUGH IS SLOW TO PROGRESS EAST OF THE AREA. A STOUT 1035MB RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON MONDAY... BRINGING A PERIOD OF TRANQUIL WEATHER BEFORE ATTENTION IS FOCUSED ON THE SIGNIFICANT SYSTEM EXPECTED TO IMPACT THE REGION TUESDAY THROUGH WEDNESDAY. AS EXPECTED OVER THE PAST FEW DAYS... THIS NEXT SYSTEM LOOKS LIKE IT WILL BE A BIT SLOWER THAN ORIGINALLY PROGGED TO EJECT OUT OF THE SOUTHWEST CONUS... AND DOESN/T LOOK TO BRING PCPN INTO OUR AREA UNTIL PERHAPS LATE MONDAY NIGHT AND MORE LIKELY ON TUESDAY. THERE REMAINS A FAIR DEGREE OF SPREAD IN THE MODEL SOLUTIONS ON THE TRACK OF THE SURFACE LOW... BUT MOST OF THE GUIDANCE HAS TRENDED TOWARD THE IDEA OFFERED BY THE ECMWF FOR SEVERAL RUNS. THIS SUGGESTS THE NEGATIVELY TILTED UPPER WAVE WILL LIFT OUT INTO THE CENTRAL PLAINS BY TUESDAY NIGHT... DEEPENING THE SURFACE LOW OVER NEBRASKA AS IT DOES SO. THEN THE SYSTEM LOOKS TO BECOME VERTICALLY STACKED AND OCCLUDE NEAR NORTHWEST IOWA LATE TUESDAY NIGHT. IT IS AT THIS POINT... WHEN THE SYSTEM IS OCCLUDING AND THE UPPER WAVE IS BEGINNING TO RUN INTO CONFLUENT FLOW OVER THE NORTHERN GREAT LAKES... THAT IT SHOULD START TO TRACK EASTWARD AND SLOWLY WEAKEN WITH TIME. THERE REMAIN SOME DIFFERENCES IN HOW THINGS WILL EVOLVE DURING THIS STAGE... BUT THE GFS... ECMWF... AND FIM CONSENSUS WOULD SUGGEST A SURFACE LOW TRACK NEAR OR A BIT SOUTH OF THE IOWA BORDER. A PROMINENT TROWAL FEATURE IS SUGGESTED BY THE THETA-E SURFACES WITH THIS SYSTEM... WITH THAT TROWAL WRAPPING INTO SOUTHERN MINNESOTA AND HELPING TO FOCUS THE HEAVIEST PCPN ACROSS CENTRAL MINNESOTA. WARM AIR SURGING NORTH AND WRAPPING INTO THE SYSTEM LOOKS TO BRING AN ELEVATED WARM LAYER INTO THE SOUTHERN PART OF THE STATE... WITH THE WARM NOSE LOOKING LIKE IT WILL BE LOCATED AROUND 825MB. WITH MINIMAL PRE-EXISTING COLD AIR IN PLACE... NEAR SURFACE TEMPERATURES WILL ALSO BE RELATIVELY WARM WITH THIS SYSTEM... FURTHER COMPLICATING PCPN-TYPE ISSUES. AT THIS POINT... THE FULL SOUNDING PROFILE LOOKS TO REMAIN BELOW FREEZING FROM AROUND THE TWIN CITIES NORTHWARD... WITH THE WARM LAYER MAX TEMPERATURE INCREASING AS YOU HEAD SOUTH... AND POSSIBLY AS WARM AS +2C NEAR THE IOWA BORDER. SURFACE TEMPERATURES MAY ALSO GET INTO THE 30-35F RANGE OVER THE SOUTHERN PART OF THE AREA. AT THIS POINT... THIS POINTS TOWARD AN ALL SNOW EVENT NORTH OF THE TWIN CITIES... THE POSSIBILITY OF SOME SLEET AS FAR NORTH AS THE TWIN CITIES METRO... AND SLEET AND SOME RAIN POSSIBLE AS YOU GET TOWARD THE IOWA BORDER. THERE COULD ALSO BE A NARROW ZONE OF FREEZING RAIN... BUT WITH SUCH MARGINALLY FREEZING SURFACE TEMPERATURES... AM NOT TOO CONCERNED ABOUT THAT POTENTIAL AT THIS POINT. FORECAST PCPN TOTALS FROM THE GFS... ECMWF... FIM... AND GFS ENSEMBLES SUGGEST AMOUNTS BETWEEN 1 AND 2 INCHES ACROSS A GOOD PART OF THE CENTRAL AND NORTHERN CWFA... WHICH COULD TRANSLATE TO SNOW AMOUNTS WELL IN EXCESS OF A FOOT. THESE SIGNIFICANT PCPN AMOUNTS LOOK REASONABLE GIVEN STRONG FORCING AND ABUNDANT MOISTURE THAT IS SUGGESTED BY ALL OF THE GUIDANCE. MIXING RATIOS IN THE MID-LEVEL ISENTROPIC LIFT ZONE WILL BE IN THE 3-4 G/KG RANGE... WHICH WOULD SUGGEST AT LEAST 6-8 INCH SNOW AMOUNTS PER 12 HOURS... AND MUCH OF THE AREA WILL SEE SNOWFALL FOR 18-24 HOURS. FRONTOGENESIS LOOKS TO BE MAXIMIZED IN THE 800-700MB LAYER... WITH A FAIRLY DEEP LAYER OF EPV PROGGED JUST ABOVE THAT... OWING TO SOME UPRIGHT INSTABILITY OVER THE SOUTHERN PART OF THE AREA... AND SYMMETRIC INSTABILITY FARTHER NORTH. THERE ALSO APPEARS TO BE A GOOD WINDOW OF 6+ HOURS WHEN THE FRONTOGENETICAL CIRCULATION IS CO-LOCATED WITH THE UPPER JET INDUCED CIRCULATION AS WE FIND OURSELVES IN A NICE COUPLED JET REGION FOR A TIME. GIVEN THIS POTENTIAL FOR SIGNIFICANT SNOWFALL... AS WELL AS THE POSSIBILITY OF SLEET AND GUSTY WINDS... A WINTER STORM WATCH WILL BE ISSUED FOR ALL OF THE MINNESOTA PORTION OF THE CWFA. THE WATCH MAY VERY WELL BE EXTENDED FARTHER EAST LATER TODAY IF CONDITIONS STILL LOOK FAVORABLE AS THINGS MOVE INTO THAT AREA. A QUICK LOOK AT THE CIPS ANALOGS SHOW A NICE MATCH IN THE MEAN SNOWFALL SWATH FROM THE TOP ANALOGS IN TERMS OF POSITION AS WELL AS MAGNITUDE TO SOME DEGREE... WITH HIGH PROBABILITIES OF GREATER THAN 8 INCHES... AS WELL AS SOME PROBABILITIES FOR 12+ AND 18+ AMOUNTS OVER PORTIONS OF THE NORTH HALF OF THE CWFA. WITH THIS SYSTEM STILL A FEW DAYS AWAY... THERE IS OBVIOUSLY A GOOD DEAL OF UNCERTAINTY... EVEN WITH WHAT WOULD SEEM TO BE FAIRLY GOOD MODEL CONSENSUS AT THIS POINT. THE MODEL CONSENSUS IS WHAT IS HELPING TO DRIVE THE DECISION TO ISSUE A WINTER STORM WATCH... BUT UNTIL THE UPPER WAVES DROP INTO THE WESTERN US BEGIN TO WORK EASTWARD... WE COULD STILL SEE THE DETAILS OF THE FORECAST CHANGE QUITE A BIT. SHOULD THE SYSTEM COME MUCH FARTHER NORTH IT WOULD MEAN MUCH MORE IN THE WAY OF SLEET AND RAIN FOR THE SOUTHERN HALF OF THE AREA... AND ANY SOUTHWARD SHIFT IN THE TRACK WOULD BRING THE AXIS OF HEAVIEST SNOWFALL TO THE TWIN CITIES AREA AND POINTS SOUTH. BUT... AT THIS POINT IN TIME THERE IS THE POTENTIAL FOR WIDESPREAD SNOW AMOUNTS IN EXCESS OF 8 INCHES WITH TOTALS WELL IN EXCESS OF A FOOT CERTAINLY POSSIBLE. NEEDLESS TO SAY... THIS SYSTEM WILL NEED TO BE MONITORED CLOSELY OVER THE COMING TWO DAYS. THE BULK OF THE ACTION LOOKS TO OCCUR FROM LATE TUESDAY AFTERNOON THROUGH MONDAY MORNING. A WEAK RIDGE OF HIGH PRESSURE WILL ARRIVE IN THE WAKE OF THE TUESDAY-WEDNESDAY SYSTEM... BRINGING DRY WEATHER FOR MOST OF WEDNESDAY NIGHT AND THURSDAY. UNLIKE WITH MOST SIGNIFICANT WINTER STORMS... WE SHOULDN/T SEE A HUGE DROP IN TEMPERATURES BEHIND THE TUESDAY- WEDNESDAY STORM... ALTHOUGH LOWS WILL DEFINITELY HAVE AN OPPORTUNITY TO BE COLDER GIVEN THE CHANCE FOR BETTER RADIATIONAL COOLING. A CHANCE FOR SOME SNOW STILL LOOKS POSSIBLE ON FRIDAY... PERHAPS LINGERING INTO SATURDAY... AS A SHORTWAVE AND ATTENDANT SURFACE LOW MOVE EAST ALONG THE US/CANADIAN BORDER. THE IS ALSO A SOUTHERN STREAM WAVE THAT IS EXPECTED TO LIFT NORTHEAST FROM THE SOUTHWEST CONUS DURING THE SAME TIME PERIOD... BUT AT THIS POINT IN TIME MOST OF THE GUIDANCE SUGGESTS ITS MAIN IMPACTS WILL OCCUR SOUTHEAST OF OUR AREA. HOWEVER... SHOULD THE NORTHERN WAVE ARRIVE MORE SLOWLY AND/OR DIG FARTHER SOUTH... THEN WE COULD SEE A MORE INTERESTING SCENARIO UNFOLD FOR OUR AREA DURING THAT TIME FRAME. FOR NOW... SIMPLY MAINTAINED POPS ON FRIDAY AND LINGERED THEM INTO SATURDAY OVER THE EASTERN PORTION OF THE AREA. TEMPERATURES LOOK LIKE THEY SHOULD BE SLIGHTLY COOLER THAN NORMAL TO ROUND OUT THE WEEK. && .AVIATION... /12Z TAF ISSUANCE/ A LOW PRESSURE SYSTEM WILL MOVE OVER CENTRAL MN TODAY. SNOW WILL CONTINUE TO DEVELOP OVER CENTRAL MN AHEAD OF THE LOW. A DRY EAST-SOUTHEASTERLY AIRFLOW IN THE LOW LEVELS CONTINUE TO DELAY THE ONSET OF THE PRECIPITATION OVER THE AREA. CEILING HEIGHTS SO FAR REMAIN ABOVE 5000 FEET AGL MOST TAF SITES IN OUR AREA THIS MORNING. EXPECT MARGINAL VFR CONDITIONS TO DEVELOP OVER THE FORECAST AREA...ESPECIALLY LATER TODAY AND TONIGHT. GUSTY SOUTHEAST WINDS OF 20 TO 40 KNOTS WILL GRADUALLY SHIFT TO NORTHWEST OVER WESTERN AND SOUTH CENTRAL MN DURING THE AFTERNOON. TONIGHT...SKIES WILL REMAIN OVERCAST WITH CEILING BETWEEN 2000-3000 FEET AGL. KMSP...A FEW SNOW FLURRIES OR SPRINKLES DEVELOPING LATER THIS MORNING. EXPECT VFR CONDITIONS TO PREVAIL THROUGH THIS EVENING WITH CEILING HEIGHTS LOWERING AROUND 3000 FEET BY MIDNIGHT. SOUTHEAST WINDS 15 TO 25 KNOTS SHIFTING TO SOUTHWEST-WEST LATER THIS AFTERNOON. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR ANOKA-BENTON-BLUE EARTH-BROWN-CARVER-CHIPPEWA- CHISAGO-DAKOTA-DOUGLAS-FARIBAULT-FREEBORN-GOODHUE-HENNEPIN- ISANTI-KANABEC-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN- MCLEOD-MEEKER-MILLE LACS-MORRISON-NICOLLET-POPE-RAMSEY- REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE- STEVENS-SWIFT-TODD-WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE. WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BENTON- DOUGLAS-KANABEC-MILLE LACS-MORRISON-POPE-STEARNS-STEVENS- SWIFT-TODD. WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM CST THIS EVENING FOR BLUE EARTH-BROWN-FARIBAULT-FREEBORN-MARTIN-REDWOOD- STEELE-WASECA-WATONWAN-YELLOW MEDICINE. WI...NONE. && $$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
301 AM CST SUN FEB 26 2012 .DISCUSSION... IN CONTRAST TO MOST OF THE WINTER... OUR AREA WILL BE IMPACTED BY QUITE A BIT OF SIGNIFICANT WEATHER OVER THE NEXT SEVERAL DAYS AS SEVERAL POTENT SHORTWAVES MOVE THROUGH THE REGION. A VARIETY OF WEATHER HEADLINES ARE THE RESULT OF THE ACTIVE WEATHER... WITH WINTER WEATHER AND WIND ADVISORIES RESULTING FROM THE SYSTEM MOVING THROUGH THE REGION TODAY... AND WINTER STORM WATCHES IN ASSOCIATION WITH THE STRONG SYSTEM EXPECTED TO IMPACT THE AREA DURING THE TUESDAY-WEDNESDAY TIME FRAME. THE LATEST WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSES DO A NICE JOB OF DEPICTING WHERE THE FEATURES OF INTEREST ARE AT THE CURRENT TIME. THE SHORTWAVE SEEN PUSHING THROUGH THE DAKOTAS IS THE DRIVING FORCE BEHIND THE SURFACE LOW PRESSURE IN THE SAME AREA... AND THE CHANCES FOR SNOW TODAY ACROSS PRIMARILY THE NORTHERN PART OF THE FORECAST AREA. HOWEVER... STRONG WINDS ALOFT AND MIXING BEHIND THE FRONTAL BOUNDARY SHOULD WORK TO GENERATE SOME SURFACE GUSTS ABOVE 40 MPH LATE THIS MORNING AND THIS AFTERNOON SOUTH OF THE MINNESOTA RIVER VALLEY. TWO OTHER SHORTWAVES OF INTEREST CAN ALSO BE SEEN IN THE WATER VAPOR IMAGERY... ONE DIVING SOUTH OFF THE PACIFIC NORTHWEST COAST AND A SECOND DROPPING SOUTH THROUGH BRITISH COLUMBIA. THE UPPER LEVEL PV ANOMALIES ASSOCIATED WITH THESE FEATURES ARE NICELY DEPICTED IN THE RUC ANALYSES... AND THE EXPECTATION IS FOR THESE TO COALESCE OVER THE SOUTHWEST CONUS TONIGHT AND MONDAY. WE WILL THEN WAIT FOR THIS POTENT UPPER TROUGH TO LIFT NORTHEAST FROM THE SOUTHERN ROCKIES AND WORK INTO THE PLAINS AND MID-UPPER MISSISSIPPI VALLEY TUESDAY INTO WEDNESDAY... BRINGING THE POTENTIAL FOR WIDESPREAD SIGNIFICANT SNOWFALL TO MUCH OF THE FORECAST AREA... ALONG WITH SOME MIXED PRECIPITATION. IN TERMS OF THE MODEL GUIDANCE... EVERYTHING HAS COME INTO EXCELLENT AGREEMENT WITH REGARD TO THE SYSTEM CURRENTLY OVER THE DAKOTAS WHICH WILL BE MOVING EAST ACROSS THE FORECAST AREA TODAY. THE SURFACE LOW SHOULD PASS THROUGH THE NORTHERN HALF OF THE AREA... WITH THE BULK OF THE PCPN ALONG AND NORTH OF ITS TRACK WHERE BETTER ISENTROPIC LIFT... DPVA... AND SOME UPPER DIVERGENCE ARE FOCUSED. HOWEVER... AS CAN BE SEEN IN CURRENT RADAR IMAGERY... THERE IS ENOUGH LOW LEVEL CONVERGENCE AND WARM ADVECTION AHEAD OF THE SURFACE TROUGH TO GENERATE SOME ECHOES. THUS FAR... MOST OF THAT ACTIVITY HAS REMAINED ALOFT... BUT WOULD EXPECT MORE OF IT TO REACH THE GROUND AS THE SYSTEM MOVES EAST AND THINGS SLOWLY SATURATE. THE GOING FORECAST LOOKS TO HAVE THINGS HANDLED FAIRLY WELL... SO ONLY MADE MINIMAL CHANGES... MAINLY TO NUDGE DOWN SNOWFALL TOTALS SLIGHTLY DUE TO A LONGER PERIOD OF VIRGA OCCURRING. KEPT THE ADVISORY IN PLACE AND EXTENDED IT THROUGH THE AFTERNOON WITH THE EXPECTATION THAT GUSTY WINDS BEHIND THE SURFACE LOW COULD KEEP SOME BLOWING SNOW AND REDUCED VISIBILITIES GOING UNTIL EVENING. THE GREATEST TOTALS STILL LOOK LIKE THEY SHOULD BE ALONG THE FAR NORTHERN PORTION OF THE FORECAST AREA... WHERE SOME AMOUNTS OF 3 OR 4 INCHES ARE POSSIBLE. AS MENTIONED EARLIER... THE STRONGEST WINDS ACROSS OUR FORECAST AREA TODAY LOOK TO DEVELOP SOUTH OF THE SURFACE LOW IN THE WAKE OF THE TROUGH/FRONTAL PASSAGE AS WINDS SHIFT TO THE SOUTHWEST AND WEST. WOULD EXPECT TO SEE SOME GUSTS ABOVE 40 MPH DURING THE AFTERNOON AS MIXING HELPS BRING DOWN THE 30-40KT WINDS PROGGED AROUND 925MB. WILL ISSUE A WIND ADVISORY FOR THE SOUTHWEST AND SOUTH TO ACCOUNT FOR THIS PERIOD OF GUSTY WINDS. KEPT SOME CHANCE OF SNOW THOUGH THE NIGHT OVER THE NORTH CENTRAL AND NORTHEAST CWFA AS MOISTURE AND CYCLONIC FLOW LINGER ON THE BACK SIDE OF THE SURFACE LOW... WHILE THE UPPER TROUGH IS SLOW TO PROGRESS EAST OF THE AREA. A STOUT 1035MB RIDGE OF HIGH PRESSURE WILL BUILD ACROSS THE AREA ON MONDAY... BRINGING A PERIOD OF TRANQUIL WEATHER BEFORE ATTENTION IS FOCUSED ON THE SIGNIFICANT SYSTEM EXPECTED TO IMPACT THE REGION TUESDAY THROUGH WEDNESDAY. AS EXPECTED OVER THE PAST FEW DAYS... THIS NEXT SYSTEM LOOKS LIKE IT WILL BE A BIT SLOWER THAN ORIGINALLY PROGGED TO EJECT OUT OF THE SOUTHWEST CONUS... AND DOESN/T LOOK TO BRING PCPN INTO OUR AREA UNTIL PERHAPS LATE MONDAY NIGHT AND MORE LIKELY ON TUESDAY. THERE REMAINS A FAIR DEGREE OF SPREAD IN THE MODEL SOLUTIONS ON THE TRACK OF THE SURFACE LOW... BUT MOST OF THE GUIDANCE HAS TRENDED TOWARD THE IDEA OFFERED BY THE ECMWF FOR SEVERAL RUNS. THIS SUGGESTS THE NEGATIVELY TILTED UPPER WAVE WILL LIFT OUT INTO THE CENTRAL PLAINS BY TUESDAY NIGHT... DEEPENING THE SURFACE LOW OVER NEBRASKA AS IT DOES SO. THEN THE SYSTEM LOOKS TO BECOME VERTICALLY STACKED AND OCCLUDE NEAR NORTHWEST IOWA LATE TUESDAY NIGHT. IT IS AT THIS POINT... WHEN THE SYSTEM IS OCCLUDING AND THE UPPER WAVE IS BEGINNING TO RUN INTO CONFLUENT FLOW OVER THE NORTHERN GREAT LAKES... THAT IT SHOULD START TO TRACK EASTWARD AND SLOWLY WEAKEN WITH TIME. THERE REMAIN SOME DIFFERENCES IN HOW THINGS WILL EVOLVE DURING THIS STAGE... BUT THE GFS... ECMWF... AND FIM CONSENSUS WOULD SUGGEST A SURFACE LOW TRACK NEAR OR A BIT SOUTH OF THE IOWA BORDER. A PROMINENT TROWAL FEATURE IS SUGGESTED BY THE THETA-E SURFACES WITH THIS SYSTEM... WITH THAT TROWAL WRAPPING INTO SOUTHERN MINNESOTA AND HELPING TO FOCUS THE HEAVIEST PCPN ACROSS CENTRAL MINNESOTA. WARM AIR SURGING NORTH AND WRAPPING INTO THE SYSTEM LOOKS TO BRING AN ELEVATED WARM LAYER INTO THE SOUTHERN PART OF THE STATE... WITH THE WARM NOSE LOOKING LIKE IT WILL BE LOCATED AROUND 825MB. WITH MINIMAL PRE-EXISTING COLD AIR IN PLACE... NEAR SURFACE TEMPERATURES WILL ALSO BE RELATIVELY WARM WITH THIS SYSTEM... FURTHER COMPLICATING PCPN-TYPE ISSUES. AT THIS POINT... THE FULL SOUNDING PROFILE LOOKS TO REMAIN BELOW FREEZING FROM AROUND THE TWIN CITIES NORTHWARD... WITH THE WARM LAYER MAX TEMPERATURE INCREASING AS YOU HEAD SOUTH... AND POSSIBLY AS WARM AS +2C NEAR THE IOWA BORDER. SURFACE TEMPERATURES MAY ALSO GET INTO THE 30-35F RANGE OVER THE SOUTHERN PART OF THE AREA. AT THIS POINT... THIS POINTS TOWARD AN ALL SNOW EVENT NORTH OF THE TWIN CITIES... THE POSSIBILITY OF SOME SLEET AS FAR NORTH AS THE TWIN CITIES METRO... AND SLEET AND SOME RAIN POSSIBLE AS YOU GET TOWARD THE IOWA BORDER. THERE COULD ALSO BE A NARROW ZONE OF FREEZING RAIN... BUT WITH SUCH MARGINALLY FREEZING SURFACE TEMPERATURES... AM NOT TOO CONCERNED ABOUT THAT POTENTIAL AT THIS POINT. FORECAST PCPN TOTALS FROM THE GFS... ECMWF... FIM... AND GFS ENSEMBLES SUGGEST AMOUNTS BETWEEN 1 AND 2 INCHES ACROSS A GOOD PART OF THE CENTRAL AND NORTHERN CWFA... WHICH COULD TRANSLATE TO SNOW AMOUNTS WELL IN EXCESS OF A FOOT. THESE SIGNIFICANT PCPN AMOUNTS LOOK REASONABLE GIVEN STRONG FORCING AND ABUNDANT MOISTURE THAT IS SUGGESTED BY ALL OF THE GUIDANCE. MIXING RATIOS IN THE MID-LEVEL ISENTROPIC LIFT ZONE WILL BE IN THE 3-4 G/KG RANGE... WHICH WOULD SUGGEST AT LEAST 6-8 INCH SNOW AMOUNTS PER 12 HOURS... AND MUCH OF THE AREA WILL SEE SNOWFALL FOR 18-24 HOURS. FRONTOGENESIS LOOKS TO BE MAXIMIZED IN THE 800-700MB LAYER... WITH A FAIRLY DEEP LAYER OF EPV PROGGED JUST ABOVE THAT... OWING TO SOME UPRIGHT INSTABILITY OVER THE SOUTHERN PART OF THE AREA... AND SYMMETRIC INSTABILITY FARTHER NORTH. THERE ALSO APPEARS TO BE A GOOD WINDOW OF 6+ HOURS WHEN THE FRONTOGENETICAL CIRCULATION IS CO-LOCATED WITH THE UPPER JET INDUCED CIRCULATION AS WE FIND OURSELVES IN A NICE COUPLED JET REGION FOR A TIME. GIVEN THIS POTENTIAL FOR SIGNIFICANT SNOWFALL... AS WELL AS THE POSSIBILITY OF SLEET AND GUSTY WINDS... A WINTER STORM WATCH WILL BE ISSUED FOR ALL OF THE MINNESOTA PORTION OF THE CWFA. THE WATCH MAY VERY WELL BE EXTENDED FARTHER EAST LATER TODAY IF CONDITIONS STILL LOOK FAVORABLE AS THINGS MOVE INTO THAT AREA. A QUICK LOOK AT THE CIPS ANALOGS SHOW A NICE MATCH IN THE MEAN SNOWFALL SWATH FROM THE TOP ANALOGS IN TERMS OF POSITION AS WELL AS MAGNITUDE TO SOME DEGREE... WITH HIGH PROBABILITIES OF GREATER THAN 8 INCHES... AS WELL AS SOME PROBABILITIES FOR 12+ AND 18+ AMOUNTS OVER PORTIONS OF THE NORTH HALF OF THE CWFA. WITH THIS SYSTEM STILL A FEW DAYS AWAY... THERE IS OBVIOUSLY A GOOD DEAL OF UNCERTAINTY... EVEN WITH WHAT WOULD SEEM TO BE FAIRLY GOOD MODEL CONSENSUS AT THIS POINT. THE MODEL CONSENSUS IS WHAT IS HELPING TO DRIVE THE DECISION TO ISSUE A WINTER STORM WATCH... BUT UNTIL THE UPPER WAVES DROP INTO THE WESTERN US BEGIN TO WORK EASTWARD... WE COULD STILL SEE THE DETAILS OF THE FORECAST CHANGE QUITE A BIT. SHOULD THE SYSTEM COME MUCH FARTHER NORTH IT WOULD MEAN MUCH MORE IN THE WAY OF SLEET AND RAIN FOR THE SOUTHERN HALF OF THE AREA... AND ANY SOUTHWARD SHIFT IN THE TRACK WOULD BRING THE AXIS OF HEAVIEST SNOWFALL TO THE TWIN CITIES AREA AND POINTS SOUTH. BUT... AT THIS POINT IN TIME THERE IS THE POTENTIAL FOR WIDESPREAD SNOW AMOUNTS IN EXCESS OF 8 INCHES WITH TOTALS WELL IN EXCESS OF A FOOT CERTAINLY POSSIBLE. NEEDLESS TO SAY... THIS SYSTEM WILL NEED TO BE MONITORED CLOSELY OVER THE COMING TWO DAYS. THE BULK OF THE ACTION LOOKS TO OCCUR FROM LATE TUESDAY AFTERNOON THROUGH MONDAY MORNING. A WEAK RIDGE OF HIGH PRESSURE WILL ARRIVE IN THE WAKE OF THE TUESDAY-WEDNESDAY SYSTEM... BRINGING DRY WEATHER FOR MOST OF WEDNESDAY NIGHT AND THURSDAY. UNLIKE WITH MOST SIGNIFICANT WINTER STORMS... WE SHOULDN/T SEE A HUGE DROP IN TEMPERATURES BEHIND THE TUESDAY- WEDNESDAY STORM... ALTHOUGH LOWS WILL DEFINITELY HAVE AN OPPORTUNITY TO BE COLDER GIVEN THE CHANCE FOR BETTER RADIATIONAL COOLING. A CHANCE FOR SOME SNOW STILL LOOKS POSSIBLE ON FRIDAY... PERHAPS LINGERING INTO SATURDAY... AS A SHORTWAVE AND ATTENDANT SURFACE LOW MOVE EAST ALONG THE US/CANADIAN BORDER. THE IS ALSO A SOUTHERN STREAM WAVE THAT IS EXPECTED TO LIFT NORTHEAST FROM THE SOUTHWEST CONUS DURING THE SAME TIME PERIOD... BUT AT THIS POINT IN TIME MOST OF THE GUIDANCE SUGGESTS ITS MAIN IMPACTS WILL OCCUR SOUTHEAST OF OUR AREA. HOWEVER... SHOULD THE NORTHERN WAVE ARRIVE MORE SLOWLY AND/OR DIG FARTHER SOUTH... THEN WE COULD SEE A MORE INTERESTING SCENARIO UNFOLD FOR OUR AREA DURING THAT TIME FRAME. FOR NOW... SIMPLY MAINTAINED POPS ON FRIDAY AND LINGERED THEM INTO SATURDAY OVER THE EASTERN PORTION OF THE AREA. TEMPERATURES LOOK LIKE THEY SHOULD BE SLIGHTLY COOLER THAN NORMAL TO ROUND OUT THE WEEK. && .AVIATION... /06Z TAF ISSUANCE/ /ISSUED 1134 PM CST SAT FEB 25 2012/ A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE TAF SITES TODAY AND TONIGHT. SNOW CHANCES WITH MVFR CEILINGS AND VISIBILITIES ARE HIGHEST FOR KAXN AND KSTC AND FEW ADJUSTMENTS WERE MADE. SATURATION MAY TAKE A LITTLE LONGER FROM KRWF THROUGH KMSP TO KEAU WITH SNOW CHANCES HIGHEST BETWEEN 12Z-18Z. CEILINGS WILL BE TRENDING DOWN AS WELL WITH MVFR FORECAST FROM KMSP ON EAST FROM LATE MORNING ONWARD. A BRISK SOUTHEAST WIND WILL OCCUR OVERNIGHT DUE TO A TIGHT PRESSURE GRADIENT AHEAD OF THE LOW. THE WIND WILL GRADUALLY COME AROUND TO A WEST NORTHWEST DIRECTION AT KRWF AND KAXN EARLY IN THE AFTERNOON AND AT THE OTHER TAF SITES DURING THE LATE AFTERNOON/EVENING. KMSP...A TEMPO GROUP FOR MVFR CEILING/VISIBILITY IN SNOW WAS PUSHED BACK A BIT WITH SATURATION TAKING A BIT LONGER THIS MORNING. CHANCES FOR MVFR CEILINGS FROM LATE MORNING ONWARD REMAIN HIGH. SOUTHEAST WINDS 13-18 KNOTS...WITH GUSTS INTO THE MID 20S OVERNIGHT WILL VEER TO THE SOUTHWEST SUNDAY AFTERNOON AND THEN TO THE WEST NORTHWEST SUNDAY NIGHT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR ANOKA-BENTON-BLUE EARTH-BROWN-CARVER-CHIPPEWA- CHISAGO-DAKOTA-DOUGLAS-FARIBAULT-FREEBORN-GOODHUE-HENNEPIN- ISANTI-KANABEC-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN- MCLEOD-MEEKER-MILLE LACS-MORRISON-NICOLLET-POPE-RAMSEY- REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE- STEVENS-SWIFT-TODD-WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE. WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BENTON- DOUGLAS-KANABEC-MILLE LACS-MORRISON-POPE-STEARNS-STEVENS- SWIFT-TODD. WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM CST THIS EVENING FOR BLUE EARTH-BROWN-FARIBAULT-FREEBORN-MARTIN-REDWOOD- STEELE-WASECA-WATONWAN-YELLOW MEDICINE. WI...NONE. && $$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
903 PM MST SAT FEB 25 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY... LOW PRESSURE SYSTEM HAS BEEN TAKING MORE OF A TURN TO THE S AS EARLIER MENTIONED...THE SURFACE LOW CENTER NW SD. UPPER LOW JUST NW OF GGW. MSAS SURFACE PRESSURE LOOP SHOWING INVERTED TROUGH EXTENDING NW FROM THE LOW ACROSS OUR WESTERN ZONES. THIS BEHAVING AS A COLD OCCLUSION WITH THE HEAVIEST SNOW LINING UP WITH THIS TROUGH...OVER VALLEY COUNTY. THIS SEEN WELL ON 88D RADAR LOOPS AS WELL AS BAND OF COLDER-TOPPED CLOUDS ON IR SATELLITE. THIS IS SLOWING DOWN...BUT MODELS WEAKEN IT OVERNIGHT. THE HRRR SHOWS THIS HEAVIER SNOW AREA MOVING SE AND THRU OUR SE LATE TONIGHT...WHICH LOOKS GOOD LOOKING AT T88D RADAR LOOP. THEREFORE THE EXPANDED WINTER WEATHER ADVISORY APPEARS ON TRACK. THIS IS MORE OF A PROGRESSIVE SYSTEM THAN EARLIER THOUGHT...SO AMOUNTS WILL PROBABLY FALL A BIT SHORT OF FORECAST...BUT LIGHTER SNOW IS OVER MUCH OF S AB/S SK...AND MODELS INDICATE LINGERING LIGHTER SNOW ALSO IN OUR AREA INTO MORNING. STRONGER W-NW WINDS ON W SIDE OF THE TROUGH...GUSTING FROM 35 TO AS HIGH AS 48 MPH IN OUR SW AND NC MT. THIS WILL TEND TO EXPAND ACROSS MUCH OF THE ARA OVERNIGHT...SO MAIN UPDATED IS TO ADJUST WINDS AND EXPAND THE AREAS OF BLOWING SNOW. SIMONSEN PREVIOUS SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...THE CURRENT SITUATION RIGHT NOW IS THAT AN UPPER LEVEL CLIPPER SYSTEM IS ENTERING WESTERN MONTANA AND SOUTHERN ALBERTA SATURDAY AFTERNOON. A SURFACE LOW IS SITTING OVER HAVRE RIGHT NOW WITH THE 700 MB LOW OVER SOUTHERN ALBERTA AND SASKATCHEWAN. THE LATEST 12Z MODEL RUNS HAVE ALL MOVED THE PRECIP FARTHER SOUTH ACROSS OUR CWA...THEN WHAT THEY SHOWED YESTERDAY. SURFACE LOW WILL TRACK FROM NEAR HAVRE THIS EVENING TO JUST SOUTH OF BAKER MONTANA LATE TONIGHT BEFORE HEADING INTO NORTH DAKOTA SUNDAY MORNING. THE 700 MB LOW WILL REMAIN JUST TO THE NORTH AND WEST OF THE SURFACE LOW AND FOLLOW THE SAME NORTHWEST TO SOUTHEAST. MODELS ARE ALL IN PRETTY GOOD AGREEMENT WITH THIS. SO DECIDED TO EXPAND THE WINTER WEATHER ADVISORY TO INCLUDE ALL OF OUR EASTERN ZONES. THIS INCLUDES ALL OF GARFIELD...MCCONE... PRAIRIE...DAWSON AND WIBAUX COUNTIES. THE GOOD NEWS ABOUT THIS SYSTEM SHIFTING SOUTHWARD IS THE FACT THAT THE HIGHER WIND SPEEDS HAVE ALSO SHIFTED FARTHER SOUTH. MOST OF THE DRIFTING AND BLOWING SNOW WILL OCCUR ACROSS THE FAR SOUTHERN ZONES AND ALSO ACROSS SOUTHEASTERN MONTANA ALONG THE I-94 CORRIDOR. THE HIGHER WIND SPEEDS ARE STILL EXPECTED TO START AFTER MIDNIGHT WHEN THE COLD FRONT PASSES THOUGH EASTERN MONTANA. THE WINDS ARE STILL EXPECTED TO LAST INTO LATE SUNDAY MORNING. SO IF YOU ARE TRAVELING DOWN TO MILES CITY OR AREAS FARTHER SOUTH BE PREPARED FOR BLOWING AND DRIFTING SNOW ALONG WITH NEW SNOWFALL. SNOWFALL TOTALS ACROSS THE SOUTH WILL BE IN THE 2 TO 4 INCH RANGE AND NORTH OF THE MISSOURI THE TOTALS WILL STILL REMAIN BETWEEN 3 TO 6 INCHES...OVER A 24 HOUR PERIOD. LOWS TEMPERATURES WILL DROP INTO THE LOWER TEENS TONIGHT AND WILL REMAIN IN THE UPPER TEENS TO LOWER 20S ACROSS EASTERN MONTANA TOMORROW AFTERNOON. THE MODELS ARE IN GOOD AGREEMENT ON WHEN TO END THE SNOWFALL. IT WILL BE SOMETIME LATE SUNDAY EVENING OR EARLY SUNDAY EVENING AS THE CLIPPER SYSTEM MOVES INTO OFF INTO THE NORTHERN PLAINS. RSMITH .LONG TERM...MONDAY NIGHT THROUGH SATURDAY... FOR THE PERIOD SUNDAY NIGHT THROUGH NEXT WEEKEND. WEAK RIDGING ON THE BACK SIDE OF THE EXITING STORM SYSTEM WILL MAKE FOR DRY CONDITIONS...BUT TEMPS WILL REMAIN COLDER THANKS TO LINGERING ARCTIC AIR INTO MONDAY. MONDAY NIGHT INTO TUESDAY ANOTHER STORM SYSTEM WILL DRIFT THROUGH THE GREAT PLAINS...POSSIBLY IMPACTING AREAS AS FAR NORTH AS WIBAUX PRAIRIE AND DAWSON COUNTIES WITH WRAPAROUND PRECIP. THE LATEST TRENDS HAVE BEEN FURTHER SOUTH WITH THIS SYSTEM...MAKING FOR LESSER IMPACTS FOR NORTHEAST MONTANA THUS TRENDED DOWN POPS SLIGHTLY DURING THIS TIME. WEAK RIDGING AGAIN RETURNS MAKING FOR MODERATING TEMPS AND LARGELY DRY CONDITIONS TUESDAY NIGHT INTO WEDNESDAY. FOR WEDNESDAY NIGHT INTO THURSDAY THE FORECAST MODELS SOMEWHAT AGREE WITH A WEAK SHORTWAVE PASSAGE THAT COULD BRING ANOTHER COLD FRONT AND A FEW SNOW SHOWERS TO NORTHEAST MONTANA. GIVEN REASONABLE CONSISTENCY THIS FAR OUT TRENDED UP POPS CLOSER TO THE CLIMATOLOGICAL NORMS OF SLIGHT CHANCE. FOR THURSDAY AND BEYOND A DRY NORTHWEST FLOW ALOFT BUILDS BACK IN...HOWEVER TEMPS WILL REMAIN SLIGHTLY BELOW NORMALS THANKS TO LINGERING MODIFIED ARCTIC AIR. GILCHRIST PREVIOUS LONG TERM DISCUSSION...OVERALL COLDER AND MORE WINTER LIKE PATTERN FOR THE EXTENDED PERIOD WITH A BROAD TROF ACROSS THE WESTERN STATES AND JET PUSHED TO THE SOUTH. MAIN FEATURE OF NOTE IS CLOSED LOW LIFTING ACROSS THE GREAT BASIN INTO THE CENTRAL PLAINS MONDAY NIGHT AND TUESDAY. EXPECT A SHARP NORTHERN EDGE TO THE ASSOCIATED PRECIPITATION WITH RIDGING ACROSS CENTRAL CANADA AND DRY AIR PUSHING SOUTH. SIGNIFICANT DIFFERENCES AMONG THE MODELS ON WHERE THIS BOUNDARY WILL OCCUR...WITH GFS BRINGING IT ACROSS SOUTHEAST MONTANA AND EC JUST BRUSHING THE SOUTHEAST ZONES. GEM IS MUCH FURTHER NORTH BUT ALSO SLOWER THEN THE OTHER MODELS. TRENDED POPS A LITTLE FURTHER TO THE SOUTH THAN IN PREVIOUS FORECAST DUE TO AGREEMENT OF GFS...GFS ENSEMBLES AND EC. ANOTHER TROF MOVES ACROSS THE STATE ON WEDNESDAY NIGHT/THURSDAY. PRECIPITATION ASSOCIATED WITH THIS TROF IS NOT AS CERTAIN WITH SOME SPLITTING OF THE TROF INDICATED IN THE MODELS. NORTHWEST FLOW OVER THE REGION FOR THE END OF THE WEEK WILL KEEP TEMPERATURES NEAR NORMAL AND WITHOUT SIGNIFICANT PRECIPITATION. EBERT && .AVIATION... IFR/MVFR CONDITIONS WILL CONTINUE THROUGH EARLY SUNDAY ACROSS THE AREA AS A LOW PRESSURE SYSTEM MOVES THROUGH. FLIGHT CONDITIONS WILL SEE SOME IMPROVEMENT TO MVFR/VFR AFTER 15Z. PROTON && .GLASGOW WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN VALLEY...PETROLEUM... GARFIELD...NORTHERN PHILLIPS...SOUTHWEST PHILLIPS...NORTHERN VALLEY. WINTER WEATHER ADVISORY UNTIL 5 PM MST SUNDAY FOR DANIELS... SHERIDAN...WESTERN ROOSEVELT...MCCONE...RICHLAND...DAWSON... PRAIRIE...WIBAUX...EASTERN ROOSEVELT. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1205 PM CST SUN FEB 26 2012 .UPDATE...MORNING UPPER AIR ANALYSIS INDICATES SUBTLE UPPER LEVEL RIDGING OVER THE EASTERN CONUS AND SUBTLE TROUGHING OVER THE WEST. A MID LEVEL LOW IS ALSO NOTED MOVING EAST INTO THE UPPER MISSISSIPPI VALLEY. MID AND UPPER LEVEL JET ENERGY IS POSITIONED DIRECTLY OVER OUR AREA TODAY...WITH A MID LEVEL JET STREAK OF AROUND 80KTS EXTENDING FROM THE FOUR CORNERS REGION TO THE MID AND UPPER MISSISSIPPI VALLEY. A 700MB JET STREAK OF AROUND 60KTS IS ALSO NOTED OVER OUR AREA...HOWEVER THIS FEATURE IS QUICKLY PUSHING EAST INTO THE MISSISSIPPI VALLEY. WATER VAPOR IMAGERY INDICATES FAIRLY DRY TROPOSPHERIC MOISTURE ACROSS THE CENTRAL PLAINS...ALTHOUGH INCREASING MID LEVEL MOISTURE IS NOTED FLOWING IN FROM THE PACIFIC VIA THE MID LEVEL JET AXIS. AT THE SURFACE AN AREA OF LOW PRESSURE IS NOTED MOVING ACROSS MINNESOTA. A COLD FRONT EXTENDS SOUTHWEST FROM THE SURFACE LOW ACROSS PORTIONS OF NEBRASKA AND AS OF 16Z WAS LOCATED FROM NEAR KBVN...TO NEAR KLBF AND KSNY. BREEZY CONDITIONS CONTINUE ACROSS OUR NORTHERN CWA AS OF MIDDAY AS LOW LEVEL PRESSURE RISES BEHIND THE BAROCLINIC ZONE PERSIST. THAT BEING SAID...SUSTAINED WINDS HAVE BEEN NO WHERE NEAR ADVISORY CRITERIA AND WITH THE LOW LEVEL PRESSURE RISES AND RESULTANT PRESSURE GRADIENT EXPECTED TO DECREASE THROUGH THE AFTERNOON HOURS...IT IS BECOMING MORE AND MORE UNLIKELY OUR CWA WILL ACTUALLY OBSERVE WIND ADVISORY WINDS TODAY. THAT BEING THE CASE...FORECAST PROXIMITY SOUNDINGS FROM THE NAM AND OPERATIONAL GFS SUGGEST AFTERNOON BOUNDARY LAYER MIXING WILL CLIMB TO SOMEWHERE BETWEEN 750MB AND 700MB...AND WITH 60KT WINDS STILL WAITING AT 700MB ACROSS PORTIONS OF OUR AREA PER RUC ANALYSIS...WILL PLAY IT SAFE AND KEEP THE ADVISORY GOING FOR AT LEAST A FEW MORE HOURS JUST TO MAKE SURE STRONGER WINDS ALOFT DONT MIX DOWN CAUSING A SUDDEN INCREASE IN WIND SPEEDS AS WE HEAD INTO THE AFTERNOON HOURS. SHOULD ADVISORY WIND SPEEDS NOT BE REALIZED WITHIN THE NEXT 2-3 HOURS HOWEVER...WILL MOST LIKELY CANCEL THE HEADLINE EARLY. MUCH DRIER LOW LEVEL AIR CONTINUES ADVECTING INTO THE AREA FROM THE WEST/NORTHWEST TODAY...WITH SURFACE DEW POINTS ALREADY WELL INTO THE SINGLE DIGITS ACROSS SOUTHWESTERN PORTIONS OF OUR CWA...THUS RESULTING IN SURFACE RH VALUES WELL BELOW 20% ACROSS OUR SOUTHWEST. RFW CONTINUES TO LOOK GOOD...WITH AFTERNOON BOUNDARY LAYER MIXING LIKELY PROMOTING DECREASING DEW POINTS FARTHER NORTHEAST ACROSS OUR CWA...PERHAPS APPROACHING KHSI...BY MID TO LATE AFTERNOON. AS A RESULT...NO CHANGES HAVE BEEN MADE TO THE RFW. && .AVIATION...18Z KGRI TAF. VFR CONDITIONS TO CONTINUE THROUGH THE TAF PERIOD. CANNOT RULE OUT SOME WEAK CU DEVELOPMENT NEAR AND NORTH OF THE TERMINAL THIS AFTERNOON AS MID LEVEL LAPSE RATES INCREASE...WITH WEAK CU DEVELOPMENT ALREADY EVIDENT ON SATELLITE IMAGERY NEAR KODX. MAY ALSO BE SOME HIGH LEVEL CLOUDS THROUGH PORTIONS OF THE TAF PERIOD. SURFACE WINDS WILL REMAIN FROM THE WEST/NORTHWEST...WITH SUSTAINED WINDS PERHAPS NEAR 26KTS POSSIBLE THROUGH MID OR LATE AFTERNOON...DECREASING SIGNIFICANTLY THEREAFTER. VISIBILITY RESTRICTIONS ARE NOT EXPECTED AT KGRI THROUGH THE NEXT 24 HOURS. && .PREV DISCUSSION... /ISSUED 419 AM CST SUN FEB 26 2012/ SHORT TERM...TODAY THROUGH TUESDAY NIGHT. THE WEATHER PATTERN WILL REMAIN ACTIVE THE NEXT COUPLE OF DAYS. EARLY THIS MORNING...A POTENT UPPER LOW PRESSURE WAS LOCATED ACROSS THE CENTRAL DAKOTAS WITH AN ASSOCIATED 996MB SURFACE LOW CENTERED IN WEST CENTRAL SOUTH DAKOTA. INTENSE PRESSURE RISES/STRONG GRADIENT BEHIND THE FRONT ACROSS THE HIGH PLAINS INTO WESTERN NEBRASKA HAS RESULTED IN SIGNIFICANT WIND GUSTS OVER 50 MPH. MODELS GENERALLY KEEP THE BRUNT OF THE STRONGEST WINDS TO THE NORTH/WEST OF OUR CWA...HOWEVER MODELS IN GENERAL HAVE NOT HANDLED THE STRENGTH OF THE SFC LOW AND MAGNITUDE OF WINDS TO THE WEST VERY WELL. FRONTAL BOUNDARY/GUSTY WINDS WILL CROSS OUR CWA THIS MORNING AND GIVEN THAT WINDS HAVE YET TO SUBSIDE...WILL GO AHEAD AND BUMP UP TIMING OF ONSET OF OUR CURRENT WIND ADVISORY AND EXPAND IN COVERAGE BY A FEW COUNTIES. THE SURFACE LOW BEGINS TO FILL DURING THE MORNING AND TREKS INTO MINNESOTA THIS AFTN. OUR STRONGEST WINDS SHOULD BE REALIZED THRU THE MORNING HOURS UNTIL AROUND MID AFTERNOON BEFORE THE THE SFC GRADIENT RELAXES...AND WINDS GRADUALLY SUBSIDE TOWARD EVENING. FORECAST SOUNDINGS SUGGEST MIXING WILL BE NEAR H75 AT TIMES TODAY AND MUCH DRIER AIR/DRY DPS WILL ADVECT EAST/MIX DOWN AND LOW RELATIVE HUMIDITIES WILL DROP BELOW 20 PCNT ACROSS MUCH OF OUR SOUTHERN CWA. LOOKS LIKE FIRE WEATHER WARNING CRITERIA WILL BE MET ACROSS NC KANSAS INTO SOUTHERN NEBRASKA. CURRENT FIRE WEATHER WATCH WILL BE CONVERTED INTO A FIRE WEATHER WARNING...WITH THAYER COUNTY SOMEWHAT QUESTIONABLE AS DPS MAY NOT LOWER SUBSTANTIALLY ENOUGH FOR RH THRESHOLDS AT TIMES. HEADING INTO TONIGHT...THE NORTHERN PLAINS SYSTEM EXITS TOWARDS THE GREAT LAKES REGION AND A 1036MB SURFACE HIGH BUILDS SOUTH FM THE EASTERN DAKOTAS ALONG THE MISSOURI RIVER. WINDS DROP...AND TEMPS ARE EXPECTED TO PLUMMET IN THE COLDER...DRY AIRMASS WITH GOOD RADIATING CONDITIONS. A COLD NIGHT IS IN STORE FOR OUR REGION WITH LOWS PRIMARILY IN THE TEENS. THE SURFACE RIDGE AXIS SHIFTS EAST ON MONDAY...ALLOWING FOR RETURN FLOW OF SOUTHEASTERLY WINDS. ATTENTION THEN TURNS TO NEXT POTENT TROUGH MOVING INTO THE ROCKIES LATE MONDAY. ISENTROPIC LIFT INCREASES AHEAD OF THIS NEXT SYSTEM AS INDICATED ON THE 295K SURFACE...HOWEVER MODELS HAVE SLOWED ONSET OF SATURATION AND ALTHOUGH CLOUD COVER WILL INCREASE...PCPN SHLD HOLD OFF NOW UNTIL MONDAY NIGHT...ESPECIALLY AFTER MIDNIGHT. MOISTURE SURGES NORTH MONDAY NIGHT IN INCREASING SOUTHERLY FLOW AND THE LLVL JET STRENGTHENS TO 60KTS. DIFFERENCES IN THERMAL FIELDS REMAIN BETWEEN THE NAM/GFS WITH THE GFS SUGGESTING THAT AS PCPN DEVELOPS...LLVL TEMPS WILL BE WARM ENOUGH TO SUPPORT A MAINLY LIQUID EVENT. THE NAM ON THE OTHER HAND CONTINUES TO SUGGEST THAT PCPN WILL DEVELOP WHEN SFC TEMPS ARE BELOW FREEZING AND MAY RESULT IN A FEW HOURS OF FREEZING RAIN/SLEET BEFORE LLVL THERMAL PROFILE WARMS AND TRANSITIONS PCPN TO RAIN. CONFIDENCE IN THE FREEZING PCPN POTENTIAL IS NOT HIGH ENOUGH YET TO INSERT IN FORECAST YET...AND WILL MAINTAIN A R/S MIX FOR NORTHERN AREAS FOR NOW. ALSO MONDAY NIGHT...WITH THE SLOWER MOISTURE RETURN/ONSET OF PCPN IN GENERAL...MODELS HAVE BACKED OFF ON INSTABILITY WITH MUCAPES REMAINING BELOW 100 J/KG AND RATHER HIT AND MISS AT THAT. WITH LESS IN THE WAY OF INSTABILITY PROGGED...HAVE REMOVED THUNDER FM THE FORECAST DURING THIS TIME FRAME. THE UPPER LOW LIFTS ACROSS THE CENTRAL PLAINS ON TUESDAY AND MODELS HAVE FINALLY COME INTO BETTER AGREEMENT FAVORING A MORE NORTHERN TRACK OF THE SYSTEM...LIFTING THE LOW INTO NC NEBRASKA/SOUTHERN SOUTH DAKOTA. PCPN CHCS CONTINUE TUESDAY AHEAD OF THE SYSTEM...APPROACHING DRY SLOT/DRY LINE. THE NAM PROGS MUCAPES AROUND 400 J/KG AHEAD OF THE DRY LINE AND POTENTIAL REMAINS FOR TSTM DEVELOPMENT AND A STRONG STORM OR TWO CANNOT BE RULED OUT. DRY LINE SWEEPS ACROSS OUR CWA BY EARLY EVENING...AND WRAPAROUND PCPN/SNOWFALL ON BACK SIDE OF UPPER LOW SHLD REMAIN TO OUR NORTH AND HAVE ONLY CARRIED SOME LOW BUFFER POPS...BUT DRY THINGS OUT BEFORE MIDNIGHT. LAST BUT NOT LEAST...ANOTHER WINDY DAY WILL UNFOLD FOLLOWING DRY LINE/FRONTAL PASSAGE ON TUESDAY. INTENSE WESTERLY WINDS WILL DEVELOP AS THE SURFACE LOW DEEPENS IN NORTHEAST NEBRASKA...RESULTING IN A TIGHT PRESSURE GRADIENT ACROSS THE CENTRAL PLAINS. WINDS LOOK TO REACH AT LEAST WIND ADVISORY CRITERIA. LONG TERM...DAYTIME WEDNESDAY THROUGH SATURDAY. FORTUNATELY...NO MAJOR ISSUES ANTICIPATED DURING THIS TIME...ALTHOUGH WILL STATE OFF THE TOP THAT EVEN THOUGH THE OFFICIAL FORECAST DEPICTS ONLY ONE PERIOD OF POSSIBLE PRECIPITATION...ON THURSDAY NIGHT...THERE COULD EASILY END UP BEING A FEW OTHER PERIODS WHERE AT LEAST SPRINKLES OR FLURRIES COULD BRUSH PARTS OF THE CWA. STARTING OFF AT 12Z WEDNESDAY...THE LATEST 00Z OR 06Z RUNS OF THE ECWMF/GFS/NAM ARE IN MUCH BETTER AGREEMENT THAN 24 HOURS AGO REGARDING THE PRIMARY POSITIONING OF SYNOPTIC FEATURES...WITH ALL 3 PLACING THE CENTER OF THE DEPARTING POWERFUL...NEARLY VERTICALLY STACKED LOW NEAR CENTRAL PORTIONS OF THE IA/MN BORDER. ALTHOUGH IT IS NOT COMPLETELY OUT OF THE QUESTION THAT THE VERY BACK EDGE OF THIS SYSTEM COULD STILL PRODUCE SOME FLURRIES OR LIGHT SNOW MAINLY WED MORNING IN FAR NORTHERN ZONES...WILL CONTINUE TO KEEP IT PRECIP FREE FOR NOW. OVER THE COURSE OF THE DAY...SHORTWAVE RIDGING WILL BUILD INTO THE PLAINS FROM THE WEST...WITH A BROAD SURFACE HIGH PRESSURE AXIS STARTING TO NOSE IN FROM THE NORTH AND DIMINISH BREEZES DURING THE AFTERNOON. BEFORE THIS OCCURS THOUGH...MOST OF THE DAYTIME HOURS WILL REMAIN QUITE BREEZY/WINDY FROM THE NORTHWEST...WITH SUSTAINED SPEEDS AROUND 25 MPH LIKELY ESPECIALLY ACROSS THE NORTHEAST 1/2 OF THE CWA. ALTHOUGH NOT QUITE ADVERTISING ADVISORY LEVEL SPEEDS JUST YET DURING THE DAY...THIS MIGHT CHANGE WITH TIME...AS GFS SOUNDINGS INDICATE MIXING TO AROUND 800MB WITH MIXED LAYER AVERAGE SPEEDS OVER 30KT. TEMP WISE...MADE VERY LITTLE CHANGE TO PREVIOUS FORECAST...RANGING FROM UPPER 30S NORTH TO NEAR 50 FAR SOUTH. IF WRAP-AROUND STRATUS IS SLOW TO VACATE NORTHEAST COUNTIES...UPPER 30S MAY BE A BIT OPTIMISTIC HOWEVER. WED NIGHT THROUGH THE DAYTIME THURSDAY...CONFIDENCE IS FAIRLY HIGH IN THE FORECAST REMAINING DRY...ESPECIALLY FOR WED NIGHT AS A SURFACE RIDGE AXIS QUICKLY SLIDES THROUGH THE AREA...PROMOTING A WELCOME PERIOD OF LIGHT BREEZES. ALTHOUGH PASSING MID/HIGH CLOUDS SHOULD KEEP TEMPS FROM BOTTOMING OUT...KEPT LOWS ABOUT THE SAME WITH 20S ACROSS MOST OF THE CWA. DURING THE DAY THURS...FORCING INCREASES AS THE NEXT BATCH OF SHORTWAVE ENERGY RIDES OUT OF THE NORTHERN ROCKIES...PRIMARILY INTO THE DAKOTAS. ALTHOUGH THIS WILL SEND AT LEAST A WEAK COLD FRONT/WIND SHIFT SOUTHWARD ACROSS THE CWA...IT CURRENTLY APPEARS THAT IT WILL REMAIN DRY WITH LIMITED LOW LEVEL MOISTURE AROUND...ALTHOUGH THE ECMWF COMES CLOSE TO BRUSHING THE FAR NORTHERN CWA WITH SOME LIGHT QPF DURING THE DAY. TEMP WISE...AGAIN PRETTY MUCH STATUS QUO WITH A RANGE FROM MID 40S NORTH TO MID 50S SOUTH. THURS NIGHT...MAINTAINED SLIGHT POPS FOR RAIN OR SNOW ACROSS ALL BUT PARTS OF THE NORTHWEST CWA PER ALLBLEND CONSENSUS...BUT CONFIDENCE IN COVERAGE IS LOW AS ADDITIONAL SHORTWAVE ENERGY SWINGS EASTWARD FROM THE CENTRAL ROCKIES...ROTATING AROUND THE SOUTHERN PERIPHERY OF THE PARENT 500MB CIRCULATION NEAR THE ND/CANADA BORDER. FORECAST SOUNDINGS FROM THE GFS REMAIN QUITE DRY...ALTHOUGH THE ECMWF TARGETS MAINLY KS ZONES FOR A LIGHT QPF EVENT WITHIN AN EAST-WEST ZONE OF MID LEVEL FRONTOGENESIS. FRIDAY/FRIDAY NIGHT...KEPT IT DRY ALTHOUGH ANOTHER BATCH OF UPPER JET ENERGY DIGGING INTO THE NORTHWEST CONUS WILL CONTINUE TO CARVE OUT A FAIRLY EXPANSIVE TROUGH ACROSS THE CENTRAL CONUS DURING THIS TIME. BOTH THE ECMWF/GFS SUGGEST THAT VARIOUS POCKETS OF LIGHT PRECIPITATION COULD FLIRT WITH THE CWA DURING THIS TIME...BUT CONFIDENCE IS TOO LOW AT THIS RANGE TO INSERT A MENTION. KEPT HIGH TEMPS FRIDAY FAIRLY UNIFORM...WITH NEARLY THE ENTIRE CWA SOMEWHERE IN THE 40S. FINALLY FOR SATURDAY...FOLLOWED ALLBLEND CONSENSUS AND PULLED MENTION OF SLIGHT POPS FROM SOUTHWESTERN CWA THAT WAS JUST INTRODUCED YESTERDAY...BUT THAT/S NOT TO SAY THAT THEY WON/T NEED RE-INTRODUCED AT SOME POINT DOWN THE ROAD AS BOTH THE ECMWF/GFS ARE IN GOOD AGREEMENT ON THE LARGE SCALE SHOWING HIGHLY AMPLIFIED NORTH-NORTHWEST FLOW ALOFT OVER THE CENTRAL PLAINS. AT LEAST FOR NOW HAVE SAT HIGHS WELL INTO THE 40S MOST AREAS...BUT THIS COULD PROVE TO BE A BIT OPTIMISTIC ESPECIALLY NORTHEAST. PEEKING JUST BEYOND THE OFFICIAL FORECAST PERIOD...NO MAJOR WEATHER SYSTEMS IN SIGHT THROUGH LEAST MARCH 5TH...WITH SOME DEGREE OF RIDGING SUGGESTED TO DOMINATE THE UPPER AIR PATTERN. && .GID WATCHES/WARNINGS/ADVISORIES... NE...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ072>076- 082>087. WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>048- 060>063-072-073-082. KS...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ005>007- 017>019. && $$ UPDATE/AVIATION...BRYANT SHORT TERM...CF LONG TERM...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1200 AM CST SUN FEB 26 2012 .UPDATE... IT LOOKS LIKE STRONG WINDS SHOULD SPREAD THROUGH EASTERN CHERRY...HOOKER AND MCPHERSON COUNTIES OVERNIGHT ACCORDING TO THE RUC WHICH HAS BEEN VERIFYING WELL. WINDS AT THE LOWEST GATES AT MERRIMAN PROFILER AND KLNX VWP ARE 40KTS AND 50KT JUST ABOVE THE LOWEST GATE. SO THE WIND ADZY HAS BEEN EXPANDED EAST ANOTHER ROW OF COUNTIES. && .PREV DISCUSSION... /ISSUED 1131 PM CST SAT FEB 25 2012/ UPDATE... AVIATION... VFR IS EXPECTED THROUGH 21Z SUNDAY. WINDS 27030G50KT ACROSS WRN NEBRASKA TONIGHT SHOULD SUBSIDE BY 08Z BUT THEN INCREASE TO 30025G40KT SUNDAY MORNING AND SPREAD ACROSS MOST OF THE FCST AREA. AFTER 21Z SUNDAY...MVFR CIGS DEVELOP ACROSS NRN NEB WITH COLD AIR SPILLING SOUTH. WINDS SUBSIDE BY 01Z MONDAY. PREV DISCUSSION... /ISSUED 1118 PM CST SAT FEB 25 2012/ UPDATE... MAJOR LEAGUE HIGH WIND EVENT CONTINUES TO SPREAD ACROSS WRN NEBRASKA THIS EVENING. MEDICINE BOW PROFILER PEAKED AT 70KT/LOWEST GATE AT 03Z AND WINDS ARE INCREASING AT THE MERRIMAN PROFILE. KIEN METAR JUST GUSTED TO 47KT. THE RUC12 SHOWS 70KT 800MB WINDS SWEEPING MOST OF THE FCST AREA OVERNIGHT AND WITH COLD AIR ADVECTION HELPING TO MIX DOWN THESE HIGH SPEED WINDS...THE HIGH WIND WARNING HAS BEEN EXPANDED ACROSS MOST OF WRN NEB UNTIL 4 AM CST. PREV DISCUSSION... /ISSUED 1009 PM CST SAT FEB 25 2012/ UPDATE... WINDS ARE INCREASING TO ADVISORY LEVELS ACROSS SHERIDAN COUNTY AND THE RUC SUGGESTS STRONG WINDS WILL PUSH INTO WESTERN CHERRY...GRANT AND ARTHUR COUNTIES. SO MORE COUNTIES HAVE BEEN ADDED TO THE ADVISORY. PREV DISCUSSION... /ISSUED 852 PM CST SAT FEB 25 2012/ UPDATE... ADDED A COUPLE MORE COUNTIES TO THE WIND ADVISORY. WE ARE GETTING SOME WARM AIR ADVECTION ACROSS SWRN NEBRASKA WHICH SHOULD HELP MIX DOWN THE STRONG WINDS AND THEY ARE PLENTY STRONG. DALTON NEB...NEAR SIDNEY...GUSTED TO 65 MPH 835 PM CST. PREV DISCUSSION... /ISSUED 820 PM CST SAT FEB 25 2012/ UPDATE... QUICK UPDATE FOR THE WIND ADVISORY CONDITIONS DEVELOPING ACROSS SWRN NEBRASKA THIS EVENING. THE ADVISORY RUNS UNTIL 4 AM CST. STRONG WINDS MAY SPREAD FARTHER EAST BUT WILL WAIT AND SEE AS STRONG RADIATIONAL COOLING COULD PUT THE BRAKES ON THE WINDS. PREV DISCUSSION... /ISSUED 552 PM CST SAT FEB 25 2012/ UPDATE... AVIATION... STRONG GUSTY SOUTH SFC WINDS...AT TIMES GUSTING TO NEAR 30 KTS...WILL CONTINUE EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED...WITH SOME MID LEVEL CLOUDINESS ACROSS NORTH CENTRAL NEBRASKA WITH HIGH CLOUDS ACROSS SOUTHERN AND CENTRAL NEBRASKA. COLD FRONT CROSSES THE AREA BY BY THE MID EVENING FROM 0100 ACROSS THE EASTERN PANHANDLE TO 0600 TOWARDS ONEILL. WINDS MAY BRIEFLY BACK TO 140 TO 170 BEFORE TURNING RAPIDLY WNW AT 20 TO 25 KTS GUSTING TO 33 KTS. WINDS WILL REMAIN WNW INCREASING AGAIN DURING THE AFTERNOON SUNDAY WITH INCREASING MOD LEVEL CLOUDS ACROSS THE NORTH. PREV DISCUSSION... /ISSUED 332 PM CST SAT FEB 25 2012/ SYNOPSIS...UPPER AIR ANALYSIS THIS MORNING HAS A PROGRESSIVE PATTERN ACROSS THE WESTERN HALF OF THE CONUS WITH 200 METER HT FALLS NOTED ACROSS IDAHO AND EASTERN WASHINGTON STATE. DOWN STREAM HT RISES UP TO 160 METERS WERE NOTED AT OMAHA WITH A LOW AMPLITUDE RIDGE PRESENT OVER THE HIGH PLAINS AND THE FRONT RANGES OF COLORADO...WYOMING AND ERN MT. A DEEPENING TROUGH OF LOW PRESSURE TO THE WEST AND EXITING HIGH PRESSURE...HAVE LED TO WINDY CONDS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THIS AFTERNOON. SUSTAINED WINDS OF 20 TO 30 MPH WITH SOME PERIODIC GUSTS TO 40 MPH HAVE BEEN COMMON. FORTUNATELY...WITH LOW LEVEL WAA WORKING INTO THE AREA FROM THE SOUTHWEST...WINDS HAVE REMAINED BELOW ADVISORY CRITERIA TDY. TEMPERATURES AS OF 2 PM CST VARIED WIDELY ACROSS THE FORECAST AREA...WITH TEMPS RANGING FROM 36 AT ONEILL...TO 51 AT OGALLALA AND IMPERIAL. DISCUSSION... NEAR TERM...TONIGHT THROUGH TUESDAY...FORECAST CHALLENGES IN THE NEAR TERM ARE WINDS...THEN PRECIPITATION CHANCES AND PRECIPITATION TYPES MONDAY NIGHT INTO TUESDAY IN ASSOCIATION WITH A STRONG LOW PRESSURE CENTER EXPECTED TO IMPACT THE CENTRAL AND NORTHERN PLAINS. FOR TONIGHT AND SUNDAY...A VIGOROUS UPPER LEVEL LOW WILL INTENSIFY AND TRACK ACROSS THE NRN TIER OF STATES OVER THE NEXT 24 HRS. PRECIPITATION ASSOCIATED WITH THIS SYSTEM IS EXPECTED TO REMAIN NORTH OF THE AREA...WITH THE EXCEPTION OF SOME PRECIPITATION ASSOCIATED WITH A COLD FROPA IN THE NORTHWEST THIS EVENING. FURTHER SOUTH...VERY DRY AIR IS IN PLACE AND SHOULD INHIBIT PCPN DEVELOPMENT. WINDS WILL BE A CONCERN FOR SUNDAY. MAV GUIDANCE IS INDICATIVE OF ADVISORY WINDS ACROSS THE NRN HALF OF THE CWA FOR SUNDAY...WITH SUSTAINED WESTERLY WINDS OF 30 TO 40 MPH...WHILE THE MET GUIDANCE IS WINDY...WITH WINDS MORE ON THE ORDER OF 15 TO 30 MPH. DIFFERENCES BETWEEN THE TWO GUIDANCE MEMBERS SEEM TO LIE WITH THE DEGREE OF MIXING AS WELL AS DIFFERENCES IN FCST HIGHS SUNDAY WITH THE MET GUIDANCE RUNNING 3 TO 7 DEGREES COOLER ON HIGHS. NO SURPRISE IT HAS THE SLOWER WINDS TOMORROW AFTERNOON. BUFKIT SOUNDINGS ARE HINTING AT ADVISORY CRITERIA WINDS TOMORROW AFTERNOON IN THE FAR NORTHERN COUNTIES WITH GUSTS TO OVER 45 MPH AROUND 18Z SUNDAY. IN LIGHT OF THE BUFKIT DATA...WOULD LIKE TO SEE BETTER AGREEMENT WITH THE MAV AND MET GUIDANCE BEFORE ISSUING ANY WIND HEADLINES FOR SUNDAY AFTERNOON. AFTER SUNDAY...FORECAST FOCUS SHIFTS TO A DEVELOPING STORM SYSTEM...WHICH HAS THE POTENTIAL TO SPREAD SIGNIFICANT SNOWS TO THE CENTRAL AND NORTHERN PLAINS TUESDAY INTO WEDNESDAY. BEGINNING MONDAY...THE UPPER PATTERN WILL BEGIN TO AMPLIFY ACROSS THE WESTERN CONUS. SURFACE HIGH PRESSURE WILL DROP SOUTH INTO THE UPPER MISSISSIPPI VALLEY...THEN THE SRN GREAT LAKES BY THE END OF THE DAY. SHALLOW ARCTIC AIR WILL BACK INTO THE AREA MONDAY...ONLY TO LIFT NORTH MONDAY NIGHT AS STRONG SRLY FLOW AND INTENSE WAA PUSHES NORTH FROM THE SRN PLAINS. TEMPS WILL BE VERY TRICKY ON MONDAY AND MONDAY NIGHT...AND CHOSE TO INCORPORATE A NON DIURNAL T FOR TEMPS LATE MONDAY INTO TUESDAY. AFTER TEMPS STRUGGLE TO GET OUT OF THE LWR 30S MONDAY...TEMPS WILL RISE INTO THE 30S AND LWR 40S OVERNIGHT AS INTENSE WARM AIR ADVECTION AND LOW LEVEL MOISTURE WORKS INTO THE REGION. OVERNIGHT LOWS SHOULD BE IN THE EARLY EVENING...WHILE HIGHS TUESDAY WILL BE EARLY WITH FALLING TEMPS EXPECTED IN THE AFTERNOON HOURS. NOW FOR PRECIPITATION...A LEAD DISTURBANCE WILL LIFT INTO WESTERN AND NORTH CENTRAL NEBRASKA MONDAY NIGHT...WHICH WILL LEAD TO INCREASED PRECIPITATION CHANCES. STRUGGLED A BIT WITH PRECIPITATION TYPE MONDAY NIGHT WITH SNOW AND RAIN SNOW MIX EXPECTED FIRST...FOLLOWED BY RAIN SHOWERS OVERNIGHT. WILL NEED TO TAKE A LOOK AT FREEZING RAIN POTENTIAL MONDAY EVENING AS WELL AS THE NAM TRIES TO HOLD ONTO A SHALLOW...SUBFREEZING LAYER IN THE EAST AND NORTHEAST. EVEN THE THREAT FOR AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE SRN ZONES WITH NEGATIVE LI/S AND SB CAPES AROUND 200J/KG. PTYES...AS WELL AS SNOW ACCUMULATIONS ON THE BACK SIDE OF THE LOW LATE TUESDAY INTO TUESDAY NIGHT WILL HINGE HEAVILY ON MODEL CHOICE. THE NAM AND CANADIAN CONTINUE TO BE NORTH WITH THEIR TRACKS...THE ECMWF IS SOUTH AND THE GFS IS A COMPROMISE. IF THE ECMWF VERIFIES...OUR FAR NORTHERN ZONES COULD BE BURIED BY THIS SYSTEM...IF THE NAM VERIFIES...THE HEAVIEST SNOWS WOULD BE PUSHED WELL NORTH OF THE CWA. WITH A GFS/ECMWF COMPROMISE...OUR NORTHWESTERN AND FAR NORTHERN ZONES HAVE THE BEST POTENTIAL FOR SIGNIFICANT SNOWS OF 6+ INCHES. IN ADDITION TO SNOW...VERY STRONG WINDS WILL DEVELOP ON THE BACK SIDE OF THIS SYSTEM...LEADING TO THE POTENTIAL FOR BLIZZARD OR NEAR BLIZZARD CONDITIONS EVEN WITH ONLY A FEW INCHES OF SNOW. WILL CONTINUE TO HIGHLIGHT THE THREAT IN THE HWO AND...GIVEN THE ONGOING UNCERTAINTIES IN THE FORECAST TRACK...WILL NOT BE ISSUING ANY HEADLINES AT THIS POINT. LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...FOLLOWED CLOSER TO THE ECMWF FOR THE TUESDAY NIGHT PERIOD. ALL MODELS BRING STRONG NORTH TO NORTHWEST WINDS ACROSS THE AREA ON THE BACKSIDE OF A POWERFUL LOW PRESSURE SYSTEM. THE ECMWF IS THE MOST AGGRESSIVE WITH WRAP AROUND SNOW...AND GIVES SEVERAL INCHES OF ACCUMULATION ACROSS NORTH CENTRAL NEBRASKA. QUITE CONCERNED THAT EVEN JUST AN INCH OR TWO...LIKE THE GFS INDICATES...COULD GIVE SOME REAL VISIBILITY PROBLEMS DUE TO BLOWING SNOW. THE ECMWF WOULD BE THE WORST CASE SCENARIO...WITH SEVERAL INCHES ACCUMULATION PLUS THE STRONG WINDS. THIS SOLUTION WOULD BE NEAR BLIZZARD...AND WILL BEEF UP THE HAZARDOUS WEATHER OUTLOOK TO ACCOUNT FOR THIS POTENTIAL. SYSTEM QUICKLY DEPARTS TO THE EAST WEDNESDAY...BUT SOME BLOWING SNOW AND FLURRIES LIKELY TO LINGER INTO THE MORNING ACROSS NORTH CENTRAL NEBRASKA. RATHER UNSETTLED WEATHER WILL CONTINUE FOR LATE WEEK INTO NEXT WEEKEND. ANOTHER SYSTEM...CURRENTLY PROJECTED TO CROSS THE NORTHERN PLAINS...WILL DRAG A COLD FRONT THROUGH THE AREA A MAYBE A FEW SNOW SHOWERS THURSDAY NIGHT. AVIATION... STRONG GUSTY SOUTH SFC WINDS...AT TIMES GUSTING TO NEAR 30 KTS...WILL CONTINUE EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED...WITH SOME MID LEVEL CLOUDINESS ACROSS NORTH CENTRAL NEBRASKA. COLD FRONT CROSSES THE AREA BY LATE EVENING...WITH SFC WINDS SWITCHING FROM SSW TO WNW AT 15 TO 25 KTS. FIRE WEATHER...GUSTY WEST TO NORTHWEST WINDS WILL COMBINE WITH HUMIDITY VALUES OF 18 TO 25 PERCENT SUNDAY TO CREATE HIGH FIRE DANGER. AT THIS TIME WILL NOT ISSUE ANY FIRE WEATHER HEADLINES DUE TO RATHER COOL TEMPERATURES IN THE UPPER 30S AND 40S. WILL HOWEVER INCLUDE A SECTION ON HIGH FIRE DANGER IN THE HAZARDOUS WEATHER OUTLOOK. EVENING AND NIGHT SHIFTS CAN EVALUATE FURTHER AND DETERMINE IF A RED FLAG WARNING IS NECESSARY FOR SUNDAY. && .LBF WATCHES/WARNINGS/ADVISORIES...HIGH WIND WARNING UNTIL 3 AM MST SUNDAY FOR NEZ004-022-023-035-056>058-094. WIND ADVISORY UNTIL 4 AM CST /3 AM MST/ SUNDAY FOR NEZ005-024- 036-059-069>071. && $$ SHORT TERM/EXTENDED...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1131 PM CST SAT FEB 25 2012 .UPDATE... .AVIATION... VFR IS EXPECTED THROUGH 21Z SUNDAY. WINDS 27030G50KT ACROSS WRN NEBRASKA TONIGHT SHOULD SUBSIDE BY 08Z BUT THEN INCREASE TO 30025G40KT SUNDAY MORNING AND SPREAD ACROSS MOST OF THE FCST AREA. AFTER 21Z SUNDAY...MVFR CIGS DEVELOP ACROSS NRN NEB WITH COLD AIR SPILLING SOUTH. WINDS SUBSIDE BY 01Z MONDAY. && .PREV DISCUSSION... /ISSUED 1118 PM CST SAT FEB 25 2012/ UPDATE... MAJOR LEAGUE HIGH WIND EVENT CONTINUES TO SPREAD ACROSS WRN NEBRASKA THIS EVENING. MEDICINE BOW PROFILER PEAKED AT 70KT/LOWEST GATE AT 03Z AND WINDS ARE INCREASING AT THE MERRIMAN PROFILE. KIEN METAR JUST GUSTED TO 47KT. THE RUC12 SHOWS 70KT 800MB WINDS SWEEPING MOST OF THE FCST AREA OVERNIGHT AND WITH COLD AIR ADVECTION HELPING TO MIX DOWN THESE HIGH SPEED WINDS...THE HIGH WIND WARNING HAS BEEN EXPANDED ACROSS MOST OF WRN NEB UNTIL 4 AM CST. PREV DISCUSSION... /ISSUED 1009 PM CST SAT FEB 25 2012/ UPDATE... WINDS ARE INCREASING TO ADVISORY LEVELS ACROSS SHERIDAN COUNTY AND THE RUC SUGGESTS STRONG WINDS WILL PUSH INTO WESTERN CHERRY...GRANT AND ARTHUR COUNTIES. SO MORE COUNTIES HAVE BEEN ADDED TO THE ADVISORY. PREV DISCUSSION... /ISSUED 852 PM CST SAT FEB 25 2012/ UPDATE... ADDED A COUPLE MORE COUNTIES TO THE WIND ADVISORY. WE ARE GETTING SOME WARM AIR ADVECTION ACROSS SWRN NEBRASKA WHICH SHOULD HELP MIX DOWN THE STRONG WINDS AND THEY ARE PLENTY STRONG. DALTON NEB...NEAR SIDNEY...GUSTED TO 65 MPH 835 PM CST. PREV DISCUSSION... /ISSUED 820 PM CST SAT FEB 25 2012/ UPDATE... QUICK UPDATE FOR THE WIND ADVISORY CONDITIONS DEVELOPING ACROSS SWRN NEBRASKA THIS EVENING. THE ADVISORY RUNS UNTIL 4 AM CST. STRONG WINDS MAY SPREAD FARTHER EAST BUT WILL WAIT AND SEE AS STRONG RADIATIONAL COOLING COULD PUT THE BRAKES ON THE WINDS. PREV DISCUSSION... /ISSUED 552 PM CST SAT FEB 25 2012/ UPDATE... AVIATION... STRONG GUSTY SOUTH SFC WINDS...AT TIMES GUSTING TO NEAR 30 KTS...WILL CONTINUE EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED...WITH SOME MID LEVEL CLOUDINESS ACROSS NORTH CENTRAL NEBRASKA WITH HIGH CLOUDS ACROSS SOUTHERN AND CENTRAL NEBRASKA. COLD FRONT CROSSES THE AREA BY BY THE MID EVENING FROM 0100 ACROSS THE EASTERN PANHANDLE TO 0600 TOWARDS ONEILL. WINDS MAY BRIEFLY BACK TO 140 TO 170 BEFORE TURNING RAPIDLY WNW AT 20 TO 25 KTS GUSTING TO 33 KTS. WINDS WILL REMAIN WNW INCREASING AGAIN DURING THE AFTERNOON SUNDAY WITH INCREASING MOD LEVEL CLOUDS ACROSS THE NORTH. PREV DISCUSSION... /ISSUED 332 PM CST SAT FEB 25 2012/ SYNOPSIS...UPPER AIR ANALYSIS THIS MORNING HAS A PROGRESSIVE PATTERN ACROSS THE WESTERN HALF OF THE CONUS WITH 200 METER HT FALLS NOTED ACROSS IDAHO AND EASTERN WASHINGTON STATE. DOWN STREAM HT RISES UP TO 160 METERS WERE NOTED AT OMAHA WITH A LOW AMPLITUDE RIDGE PRESENT OVER THE HIGH PLAINS AND THE FRONT RANGES OF COLORADO...WYOMING AND ERN MT. A DEEPENING TROUGH OF LOW PRESSURE TO THE WEST AND EXITING HIGH PRESSURE...HAVE LED TO WINDY CONDS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THIS AFTERNOON. SUSTAINED WINDS OF 20 TO 30 MPH WITH SOME PERIODIC GUSTS TO 40 MPH HAVE BEEN COMMON. FORTUNATELY...WITH LOW LEVEL WAA WORKING INTO THE AREA FROM THE SOUTHWEST...WINDS HAVE REMAINED BELOW ADVISORY CRITERIA TDY. TEMPERATURES AS OF 2 PM CST VARIED WIDELY ACROSS THE FORECAST AREA...WITH TEMPS RANGING FROM 36 AT ONEILL...TO 51 AT OGALLALA AND IMPERIAL. DISCUSSION... NEAR TERM...TONIGHT THROUGH TUESDAY...FORECAST CHALLENGES IN THE NEAR TERM ARE WINDS...THEN PRECIPITATION CHANCES AND PRECIPITATION TYPES MONDAY NIGHT INTO TUESDAY IN ASSOCIATION WITH A STRONG LOW PRESSURE CENTER EXPECTED TO IMPACT THE CENTRAL AND NORTHERN PLAINS. FOR TONIGHT AND SUNDAY...A VIGOROUS UPPER LEVEL LOW WILL INTENSIFY AND TRACK ACROSS THE NRN TIER OF STATES OVER THE NEXT 24 HRS. PRECIPITATION ASSOCIATED WITH THIS SYSTEM IS EXPECTED TO REMAIN NORTH OF THE AREA...WITH THE EXCEPTION OF SOME PRECIPITATION ASSOCIATED WITH A COLD FROPA IN THE NORTHWEST THIS EVENING. FURTHER SOUTH...VERY DRY AIR IS IN PLACE AND SHOULD INHIBIT PCPN DEVELOPMENT. WINDS WILL BE A CONCERN FOR SUNDAY. MAV GUIDANCE IS INDICATIVE OF ADVISORY WINDS ACROSS THE NRN HALF OF THE CWA FOR SUNDAY...WITH SUSTAINED WESTERLY WINDS OF 30 TO 40 MPH...WHILE THE MET GUIDANCE IS WINDY...WITH WINDS MORE ON THE ORDER OF 15 TO 30 MPH. DIFFERENCES BETWEEN THE TWO GUIDANCE MEMBERS SEEM TO LIE WITH THE DEGREE OF MIXING AS WELL AS DIFFERENCES IN FCST HIGHS SUNDAY WITH THE MET GUIDANCE RUNNING 3 TO 7 DEGREES COOLER ON HIGHS. NO SURPRISE IT HAS THE SLOWER WINDS TOMORROW AFTERNOON. BUFKIT SOUNDINGS ARE HINTING AT ADVISORY CRITERIA WINDS TOMORROW AFTERNOON IN THE FAR NORTHERN COUNTIES WITH GUSTS TO OVER 45 MPH AROUND 18Z SUNDAY. IN LIGHT OF THE BUFKIT DATA...WOULD LIKE TO SEE BETTER AGREEMENT WITH THE MAV AND MET GUIDANCE BEFORE ISSUING ANY WIND HEADLINES FOR SUNDAY AFTERNOON. AFTER SUNDAY...FORECAST FOCUS SHIFTS TO A DEVELOPING STORM SYSTEM...WHICH HAS THE POTENTIAL TO SPREAD SIGNIFICANT SNOWS TO THE CENTRAL AND NORTHERN PLAINS TUESDAY INTO WEDNESDAY. BEGINNING MONDAY...THE UPPER PATTERN WILL BEGIN TO AMPLIFY ACROSS THE WESTERN CONUS. SURFACE HIGH PRESSURE WILL DROP SOUTH INTO THE UPPER MISSISSIPPI VALLEY...THEN THE SRN GREAT LAKES BY THE END OF THE DAY. SHALLOW ARCTIC AIR WILL BACK INTO THE AREA MONDAY...ONLY TO LIFT NORTH MONDAY NIGHT AS STRONG SRLY FLOW AND INTENSE WAA PUSHES NORTH FROM THE SRN PLAINS. TEMPS WILL BE VERY TRICKY ON MONDAY AND MONDAY NIGHT...AND CHOSE TO INCORPORATE A NON DIURNAL T FOR TEMPS LATE MONDAY INTO TUESDAY. AFTER TEMPS STRUGGLE TO GET OUT OF THE LWR 30S MONDAY...TEMPS WILL RISE INTO THE 30S AND LWR 40S OVERNIGHT AS INTENSE WARM AIR ADVECTION AND LOW LEVEL MOISTURE WORKS INTO THE REGION. OVERNIGHT LOWS SHOULD BE IN THE EARLY EVENING...WHILE HIGHS TUESDAY WILL BE EARLY WITH FALLING TEMPS EXPECTED IN THE AFTERNOON HOURS. NOW FOR PRECIPITATION...A LEAD DISTURBANCE WILL LIFT INTO WESTERN AND NORTH CENTRAL NEBRASKA MONDAY NIGHT...WHICH WILL LEAD TO INCREASED PRECIPITATION CHANCES. STRUGGLED A BIT WITH PRECIPITATION TYPE MONDAY NIGHT WITH SNOW AND RAIN SNOW MIX EXPECTED FIRST...FOLLOWED BY RAIN SHOWERS OVERNIGHT. WILL NEED TO TAKE A LOOK AT FREEZING RAIN POTENTIAL MONDAY EVENING AS WELL AS THE NAM TRIES TO HOLD ONTO A SHALLOW...SUBFREEZING LAYER IN THE EAST AND NORTHEAST. EVEN THE THREAT FOR AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE SRN ZONES WITH NEGATIVE LI/S AND SB CAPES AROUND 200J/KG. PTYES...AS WELL AS SNOW ACCUMULATIONS ON THE BACK SIDE OF THE LOW LATE TUESDAY INTO TUESDAY NIGHT WILL HINGE HEAVILY ON MODEL CHOICE. THE NAM AND CANADIAN CONTINUE TO BE NORTH WITH THEIR TRACKS...THE ECMWF IS SOUTH AND THE GFS IS A COMPROMISE. IF THE ECMWF VERIFIES...OUR FAR NORTHERN ZONES COULD BE BURIED BY THIS SYSTEM...IF THE NAM VERIFIES...THE HEAVIEST SNOWS WOULD BE PUSHED WELL NORTH OF THE CWA. WITH A GFS/ECMWF COMPROMISE...OUR NORTHWESTERN AND FAR NORTHERN ZONES HAVE THE BEST POTENTIAL FOR SIGNIFICANT SNOWS OF 6+ INCHES. IN ADDITION TO SNOW...VERY STRONG WINDS WILL DEVELOP ON THE BACK SIDE OF THIS SYSTEM...LEADING TO THE POTENTIAL FOR BLIZZARD OR NEAR BLIZZARD CONDITIONS EVEN WITH ONLY A FEW INCHES OF SNOW. WILL CONTINUE TO HIGHLIGHT THE THREAT IN THE HWO AND...GIVEN THE ONGOING UNCERTAINTIES IN THE FORECAST TRACK...WILL NOT BE ISSUING ANY HEADLINES AT THIS POINT. LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...FOLLOWED CLOSER TO THE ECMWF FOR THE TUESDAY NIGHT PERIOD. ALL MODELS BRING STRONG NORTH TO NORTHWEST WINDS ACROSS THE AREA ON THE BACKSIDE OF A POWERFUL LOW PRESSURE SYSTEM. THE ECMWF IS THE MOST AGGRESSIVE WITH WRAP AROUND SNOW...AND GIVES SEVERAL INCHES OF ACCUMULATION ACROSS NORTH CENTRAL NEBRASKA. QUITE CONCERNED THAT EVEN JUST AN INCH OR TWO...LIKE THE GFS INDICATES...COULD GIVE SOME REAL VISIBILITY PROBLEMS DUE TO BLOWING SNOW. THE ECMWF WOULD BE THE WORST CASE SCENARIO...WITH SEVERAL INCHES ACCUMULATION PLUS THE STRONG WINDS. THIS SOLUTION WOULD BE NEAR BLIZZARD...AND WILL BEEF UP THE HAZARDOUS WEATHER OUTLOOK TO ACCOUNT FOR THIS POTENTIAL. SYSTEM QUICKLY DEPARTS TO THE EAST WEDNESDAY...BUT SOME BLOWING SNOW AND FLURRIES LIKELY TO LINGER INTO THE MORNING ACROSS NORTH CENTRAL NEBRASKA. RATHER UNSETTLED WEATHER WILL CONTINUE FOR LATE WEEK INTO NEXT WEEKEND. ANOTHER SYSTEM...CURRENTLY PROJECTED TO CROSS THE NORTHERN PLAINS...WILL DRAG A COLD FRONT THROUGH THE AREA A MAYBE A FEW SNOW SHOWERS THURSDAY NIGHT. AVIATION... STRONG GUSTY SOUTH SFC WINDS...AT TIMES GUSTING TO NEAR 30 KTS...WILL CONTINUE EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED...WITH SOME MID LEVEL CLOUDINESS ACROSS NORTH CENTRAL NEBRASKA. COLD FRONT CROSSES THE AREA BY LATE EVENING...WITH SFC WINDS SWITCHING FROM SSW TO WNW AT 15 TO 25 KTS. FIRE WEATHER...GUSTY WEST TO NORTHWEST WINDS WILL COMBINE WITH HUMIDITY VALUES OF 18 TO 25 PERCENT SUNDAY TO CREATE HIGH FIRE DANGER. AT THIS TIME WILL NOT ISSUE ANY FIRE WEATHER HEADLINES DUE TO RATHER COOL TEMPERATURES IN THE UPPER 30S AND 40S. WILL HOWEVER INCLUDE A SECTION ON HIGH FIRE DANGER IN THE HAZARDOUS WEATHER OUTLOOK. EVENING AND NIGHT SHIFTS CAN EVALUATE FURTHER AND DETERMINE IF A RED FLAG WARNING IS NECESSARY FOR SUNDAY. && .LBF WATCHES/WARNINGS/ADVISORIES...HIGH WIND WARNING UNTIL 3 AM MST SUNDAY FOR NEZ004-022-023-035- 056>058-094. WIND ADVISORY UNTIL 4 AM CST /3 AM MST/ SUNDAY FOR NEZ059- 069>071. && $$ SHORT TERM/EXTENDED...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1118 PM CST SAT FEB 25 2012 .UPDATE... MAJOR LEAGUE HIGH WIND EVENT CONTINUES TO SPREAD ACROSS WRN NEBRASKA THIS EVENING. MEDICINE BOW PROFILER PEAKED AT 70KT/LOWEST GATE AT 03Z AND WINDS ARE INCREASING AT THE MERRIMAN PROFILE. KIEN METAR JUST GUSTED TO 47KT. THE RUC12 SHOWS 70KT 800MB WINDS SWEEPING MOST OF THE FCST AREA OVERNIGHT AND WITH COLD AIR ADVECTION HELPING TO MIX DOWN THESE HIGH SPEED WINDS...THE HIGH WIND WARNING HAS BEEN EXPANDED ACROSS MOST OF WRN NEB UNTIL 4 AM CST. && .PREV DISCUSSION... /ISSUED 1009 PM CST SAT FEB 25 2012/ UPDATE... WINDS ARE INCREASING TO ADVISORY LEVELS ACROSS SHERIDAN COUNTY AND THE RUC SUGGESTS STRONG WINDS WILL PUSH INTO WESTERN CHERRY...GRANT AND ARTHUR COUNTIES. SO MORE COUNTIES HAVE BEEN ADDED TO THE ADVISORY. PREV DISCUSSION... /ISSUED 852 PM CST SAT FEB 25 2012/ UPDATE... ADDED A COUPLE MORE COUNTIES TO THE WIND ADVISORY. WE ARE GETTING SOME WARM AIR ADVECTION ACROSS SWRN NEBRASKA WHICH SHOULD HELP MIX DOWN THE STRONG WINDS AND THEY ARE PLENTY STRONG. DALTON NEB...NEAR SIDNEY...GUSTED TO 65 MPH 835 PM CST. PREV DISCUSSION... /ISSUED 820 PM CST SAT FEB 25 2012/ UPDATE... QUICK UPDATE FOR THE WIND ADVISORY CONDITIONS DEVELOPING ACROSS SWRN NEBRASKA THIS EVENING. THE ADVISORY RUNS UNTIL 4 AM CST. STRONG WINDS MAY SPREAD FARTHER EAST BUT WILL WAIT AND SEE AS STRONG RADIATIONAL COOLING COULD PUT THE BRAKES ON THE WINDS. PREV DISCUSSION... /ISSUED 552 PM CST SAT FEB 25 2012/ UPDATE... AVIATION... STRONG GUSTY SOUTH SFC WINDS...AT TIMES GUSTING TO NEAR 30 KTS...WILL CONTINUE EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED...WITH SOME MID LEVEL CLOUDINESS ACROSS NORTH CENTRAL NEBRASKA WITH HIGH CLOUDS ACROSS SOUTHERN AND CENTRAL NEBRASKA. COLD FRONT CROSSES THE AREA BY BY THE MID EVENING FROM 0100 ACROSS THE EASTERN PANHANDLE TO 0600 TOWARDS ONEILL. WINDS MAY BRIEFLY BACK TO 140 TO 170 BEFORE TURNING RAPIDLY WNW AT 20 TO 25 KTS GUSTING TO 33 KTS. WINDS WILL REMAIN WNW INCREASING AGAIN DURING THE AFTERNOON SUNDAY WITH INCREASING MOD LEVEL CLOUDS ACROSS THE NORTH. PREV DISCUSSION... /ISSUED 332 PM CST SAT FEB 25 2012/ SYNOPSIS...UPPER AIR ANALYSIS THIS MORNING HAS A PROGRESSIVE PATTERN ACROSS THE WESTERN HALF OF THE CONUS WITH 200 METER HT FALLS NOTED ACROSS IDAHO AND EASTERN WASHINGTON STATE. DOWN STREAM HT RISES UP TO 160 METERS WERE NOTED AT OMAHA WITH A LOW AMPLITUDE RIDGE PRESENT OVER THE HIGH PLAINS AND THE FRONT RANGES OF COLORADO...WYOMING AND ERN MT. A DEEPENING TROUGH OF LOW PRESSURE TO THE WEST AND EXITING HIGH PRESSURE...HAVE LED TO WINDY CONDS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THIS AFTERNOON. SUSTAINED WINDS OF 20 TO 30 MPH WITH SOME PERIODIC GUSTS TO 40 MPH HAVE BEEN COMMON. FORTUNATELY...WITH LOW LEVEL WAA WORKING INTO THE AREA FROM THE SOUTHWEST...WINDS HAVE REMAINED BELOW ADVISORY CRITERIA TDY. TEMPERATURES AS OF 2 PM CST VARIED WIDELY ACROSS THE FORECAST AREA...WITH TEMPS RANGING FROM 36 AT ONEILL...TO 51 AT OGALLALA AND IMPERIAL. DISCUSSION... NEAR TERM...TONIGHT THROUGH TUESDAY...FORECAST CHALLENGES IN THE NEAR TERM ARE WINDS...THEN PRECIPITATION CHANCES AND PRECIPITATION TYPES MONDAY NIGHT INTO TUESDAY IN ASSOCIATION WITH A STRONG LOW PRESSURE CENTER EXPECTED TO IMPACT THE CENTRAL AND NORTHERN PLAINS. FOR TONIGHT AND SUNDAY...A VIGOROUS UPPER LEVEL LOW WILL INTENSIFY AND TRACK ACROSS THE NRN TIER OF STATES OVER THE NEXT 24 HRS. PRECIPITATION ASSOCIATED WITH THIS SYSTEM IS EXPECTED TO REMAIN NORTH OF THE AREA...WITH THE EXCEPTION OF SOME PRECIPITATION ASSOCIATED WITH A COLD FROPA IN THE NORTHWEST THIS EVENING. FURTHER SOUTH...VERY DRY AIR IS IN PLACE AND SHOULD INHIBIT PCPN DEVELOPMENT. WINDS WILL BE A CONCERN FOR SUNDAY. MAV GUIDANCE IS INDICATIVE OF ADVISORY WINDS ACROSS THE NRN HALF OF THE CWA FOR SUNDAY...WITH SUSTAINED WESTERLY WINDS OF 30 TO 40 MPH...WHILE THE MET GUIDANCE IS WINDY...WITH WINDS MORE ON THE ORDER OF 15 TO 30 MPH. DIFFERENCES BETWEEN THE TWO GUIDANCE MEMBERS SEEM TO LIE WITH THE DEGREE OF MIXING AS WELL AS DIFFERENCES IN FCST HIGHS SUNDAY WITH THE MET GUIDANCE RUNNING 3 TO 7 DEGREES COOLER ON HIGHS. NO SURPRISE IT HAS THE SLOWER WINDS TOMORROW AFTERNOON. BUFKIT SOUNDINGS ARE HINTING AT ADVISORY CRITERIA WINDS TOMORROW AFTERNOON IN THE FAR NORTHERN COUNTIES WITH GUSTS TO OVER 45 MPH AROUND 18Z SUNDAY. IN LIGHT OF THE BUFKIT DATA...WOULD LIKE TO SEE BETTER AGREEMENT WITH THE MAV AND MET GUIDANCE BEFORE ISSUING ANY WIND HEADLINES FOR SUNDAY AFTERNOON. AFTER SUNDAY...FORECAST FOCUS SHIFTS TO A DEVELOPING STORM SYSTEM...WHICH HAS THE POTENTIAL TO SPREAD SIGNIFICANT SNOWS TO THE CENTRAL AND NORTHERN PLAINS TUESDAY INTO WEDNESDAY. BEGINNING MONDAY...THE UPPER PATTERN WILL BEGIN TO AMPLIFY ACROSS THE WESTERN CONUS. SURFACE HIGH PRESSURE WILL DROP SOUTH INTO THE UPPER MISSISSIPPI VALLEY...THEN THE SRN GREAT LAKES BY THE END OF THE DAY. SHALLOW ARCTIC AIR WILL BACK INTO THE AREA MONDAY...ONLY TO LIFT NORTH MONDAY NIGHT AS STRONG SRLY FLOW AND INTENSE WAA PUSHES NORTH FROM THE SRN PLAINS. TEMPS WILL BE VERY TRICKY ON MONDAY AND MONDAY NIGHT...AND CHOSE TO INCORPORATE A NON DIURNAL T FOR TEMPS LATE MONDAY INTO TUESDAY. AFTER TEMPS STRUGGLE TO GET OUT OF THE LWR 30S MONDAY...TEMPS WILL RISE INTO THE 30S AND LWR 40S OVERNIGHT AS INTENSE WARM AIR ADVECTION AND LOW LEVEL MOISTURE WORKS INTO THE REGION. OVERNIGHT LOWS SHOULD BE IN THE EARLY EVENING...WHILE HIGHS TUESDAY WILL BE EARLY WITH FALLING TEMPS EXPECTED IN THE AFTERNOON HOURS. NOW FOR PRECIPITATION...A LEAD DISTURBANCE WILL LIFT INTO WESTERN AND NORTH CENTRAL NEBRASKA MONDAY NIGHT...WHICH WILL LEAD TO INCREASED PRECIPITATION CHANCES. STRUGGLED A BIT WITH PRECIPITATION TYPE MONDAY NIGHT WITH SNOW AND RAIN SNOW MIX EXPECTED FIRST...FOLLOWED BY RAIN SHOWERS OVERNIGHT. WILL NEED TO TAKE A LOOK AT FREEZING RAIN POTENTIAL MONDAY EVENING AS WELL AS THE NAM TRIES TO HOLD ONTO A SHALLOW...SUBFREEZING LAYER IN THE EAST AND NORTHEAST. EVEN THE THREAT FOR AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE SRN ZONES WITH NEGATIVE LI/S AND SB CAPES AROUND 200J/KG. PTYES...AS WELL AS SNOW ACCUMULATIONS ON THE BACK SIDE OF THE LOW LATE TUESDAY INTO TUESDAY NIGHT WILL HINGE HEAVILY ON MODEL CHOICE. THE NAM AND CANADIAN CONTINUE TO BE NORTH WITH THEIR TRACKS...THE ECMWF IS SOUTH AND THE GFS IS A COMPROMISE. IF THE ECMWF VERIFIES...OUR FAR NORTHERN ZONES COULD BE BURIED BY THIS SYSTEM...IF THE NAM VERIFIES...THE HEAVIEST SNOWS WOULD BE PUSHED WELL NORTH OF THE CWA. WITH A GFS/ECMWF COMPROMISE...OUR NORTHWESTERN AND FAR NORTHERN ZONES HAVE THE BEST POTENTIAL FOR SIGNIFICANT SNOWS OF 6+ INCHES. IN ADDITION TO SNOW...VERY STRONG WINDS WILL DEVELOP ON THE BACK SIDE OF THIS SYSTEM...LEADING TO THE POTENTIAL FOR BLIZZARD OR NEAR BLIZZARD CONDITIONS EVEN WITH ONLY A FEW INCHES OF SNOW. WILL CONTINUE TO HIGHLIGHT THE THREAT IN THE HWO AND...GIVEN THE ONGOING UNCERTAINTIES IN THE FORECAST TRACK...WILL NOT BE ISSUING ANY HEADLINES AT THIS POINT. LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...FOLLOWED CLOSER TO THE ECMWF FOR THE TUESDAY NIGHT PERIOD. ALL MODELS BRING STRONG NORTH TO NORTHWEST WINDS ACROSS THE AREA ON THE BACKSIDE OF A POWERFUL LOW PRESSURE SYSTEM. THE ECMWF IS THE MOST AGGRESSIVE WITH WRAP AROUND SNOW...AND GIVES SEVERAL INCHES OF ACCUMULATION ACROSS NORTH CENTRAL NEBRASKA. QUITE CONCERNED THAT EVEN JUST AN INCH OR TWO...LIKE THE GFS INDICATES...COULD GIVE SOME REAL VISIBILITY PROBLEMS DUE TO BLOWING SNOW. THE ECMWF WOULD BE THE WORST CASE SCENARIO...WITH SEVERAL INCHES ACCUMULATION PLUS THE STRONG WINDS. THIS SOLUTION WOULD BE NEAR BLIZZARD...AND WILL BEEF UP THE HAZARDOUS WEATHER OUTLOOK TO ACCOUNT FOR THIS POTENTIAL. SYSTEM QUICKLY DEPARTS TO THE EAST WEDNESDAY...BUT SOME BLOWING SNOW AND FLURRIES LIKELY TO LINGER INTO THE MORNING ACROSS NORTH CENTRAL NEBRASKA. RATHER UNSETTLED WEATHER WILL CONTINUE FOR LATE WEEK INTO NEXT WEEKEND. ANOTHER SYSTEM...CURRENTLY PROJECTED TO CROSS THE NORTHERN PLAINS...WILL DRAG A COLD FRONT THROUGH THE AREA A MAYBE A FEW SNOW SHOWERS THURSDAY NIGHT. AVIATION... STRONG GUSTY SOUTH SFC WINDS...AT TIMES GUSTING TO NEAR 30 KTS...WILL CONTINUE EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED...WITH SOME MID LEVEL CLOUDINESS ACROSS NORTH CENTRAL NEBRASKA. COLD FRONT CROSSES THE AREA BY LATE EVENING...WITH SFC WINDS SWITCHING FROM SSW TO WNW AT 15 TO 25 KTS. FIRE WEATHER...GUSTY WEST TO NORTHWEST WINDS WILL COMBINE WITH HUMIDITY VALUES OF 18 TO 25 PERCENT SUNDAY TO CREATE HIGH FIRE DANGER. AT THIS TIME WILL NOT ISSUE ANY FIRE WEATHER HEADLINES DUE TO RATHER COOL TEMPERATURES IN THE UPPER 30S AND 40S. WILL HOWEVER INCLUDE A SECTION ON HIGH FIRE DANGER IN THE HAZARDOUS WEATHER OUTLOOK. EVENING AND NIGHT SHIFTS CAN EVALUATE FURTHER AND DETERMINE IF A RED FLAG WARNING IS NECESSARY FOR SUNDAY. && .LBF WATCHES/WARNINGS/ADVISORIES...HIGH WIND WARNING UNTIL 3 AM MST SUNDAY FOR NEZ004-022-023-035- 056>058-094. WIND ADVISORY UNTIL 4 AM CST /3 AM MST/ SUNDAY FOR NEZ059- 069>071. && $$ SHORT TERM/EXTENDED...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1009 PM CST SAT FEB 25 2012 .UPDATE... WINDS ARE INCREASING TO ADVISORY LEVELS ACROSS SHERIDAN COUNTY AND THE RUC SUGGESTS STRONG WINDS WILL PUSH INTO WESTERN CHERRY...GRANT AND ARTHUR COUNTIES. SO MORE COUNTIES HAVE BEEN ADDED TO THE ADVISORY. && .PREV DISCUSSION... /ISSUED 852 PM CST SAT FEB 25 2012/ UPDATE... ADDED A COUPLE MORE COUNTIES TO THE WIND ADVISORY. WE ARE GETTING SOME WARM AIR ADVECTION ACROSS SWRN NEBRASKA WHICH SHOULD HELP MIX DOWN THE STRONG WINDS AND THEY ARE PLENTY STRONG. DALTON NEB...NEAR SIDNEY...GUSTED TO 65 MPH 835 PM CST. PREV DISCUSSION... /ISSUED 820 PM CST SAT FEB 25 2012/ UPDATE... QUICK UPDATE FOR THE WIND ADVISORY CONDITIONS DEVELOPING ACROSS SWRN NEBRASKA THIS EVENING. THE ADVISORY RUNS UNTIL 4 AM CST. STRONG WINDS MAY SPREAD FARTHER EAST BUT WILL WAIT AND SEE AS STRONG RADIATIONAL COOLING COULD PUT THE BRAKES ON THE WINDS. PREV DISCUSSION... /ISSUED 552 PM CST SAT FEB 25 2012/ UPDATE... AVIATION... STRONG GUSTY SOUTH SFC WINDS...AT TIMES GUSTING TO NEAR 30 KTS...WILL CONTINUE EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED...WITH SOME MID LEVEL CLOUDINESS ACROSS NORTH CENTRAL NEBRASKA WITH HIGH CLOUDS ACROSS SOUTHERN AND CENTRAL NEBRASKA. COLD FRONT CROSSES THE AREA BY BY THE MID EVENING FROM 0100 ACROSS THE EASTERN PANHANDLE TO 0600 TOWARDS ONEILL. WINDS MAY BRIEFLY BACK TO 140 TO 170 BEFORE TURNING RAPIDLY WNW AT 20 TO 25 KTS GUSTING TO 33 KTS. WINDS WILL REMAIN WNW INCREASING AGAIN DURING THE AFTERNOON SUNDAY WITH INCREASING MOD LEVEL CLOUDS ACROSS THE NORTH. PREV DISCUSSION... /ISSUED 332 PM CST SAT FEB 25 2012/ SYNOPSIS...UPPER AIR ANALYSIS THIS MORNING HAS A PROGRESSIVE PATTERN ACROSS THE WESTERN HALF OF THE CONUS WITH 200 METER HT FALLS NOTED ACROSS IDAHO AND EASTERN WASHINGTON STATE. DOWN STREAM HT RISES UP TO 160 METERS WERE NOTED AT OMAHA WITH A LOW AMPLITUDE RIDGE PRESENT OVER THE HIGH PLAINS AND THE FRONT RANGES OF COLORADO...WYOMING AND ERN MT. A DEEPENING TROUGH OF LOW PRESSURE TO THE WEST AND EXITING HIGH PRESSURE...HAVE LED TO WINDY CONDS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THIS AFTERNOON. SUSTAINED WINDS OF 20 TO 30 MPH WITH SOME PERIODIC GUSTS TO 40 MPH HAVE BEEN COMMON. FORTUNATELY...WITH LOW LEVEL WAA WORKING INTO THE AREA FROM THE SOUTHWEST...WINDS HAVE REMAINED BELOW ADVISORY CRITERIA TDY. TEMPERATURES AS OF 2 PM CST VARIED WIDELY ACROSS THE FORECAST AREA...WITH TEMPS RANGING FROM 36 AT ONEILL...TO 51 AT OGALLALA AND IMPERIAL. DISCUSSION... NEAR TERM...TONIGHT THROUGH TUESDAY...FORECAST CHALLENGES IN THE NEAR TERM ARE WINDS...THEN PRECIPITATION CHANCES AND PRECIPITATION TYPES MONDAY NIGHT INTO TUESDAY IN ASSOCIATION WITH A STRONG LOW PRESSURE CENTER EXPECTED TO IMPACT THE CENTRAL AND NORTHERN PLAINS. FOR TONIGHT AND SUNDAY...A VIGOROUS UPPER LEVEL LOW WILL INTENSIFY AND TRACK ACROSS THE NRN TIER OF STATES OVER THE NEXT 24 HRS. PRECIPITATION ASSOCIATED WITH THIS SYSTEM IS EXPECTED TO REMAIN NORTH OF THE AREA...WITH THE EXCEPTION OF SOME PRECIPITATION ASSOCIATED WITH A COLD FROPA IN THE NORTHWEST THIS EVENING. FURTHER SOUTH...VERY DRY AIR IS IN PLACE AND SHOULD INHIBIT PCPN DEVELOPMENT. WINDS WILL BE A CONCERN FOR SUNDAY. MAV GUIDANCE IS INDICATIVE OF ADVISORY WINDS ACROSS THE NRN HALF OF THE CWA FOR SUNDAY...WITH SUSTAINED WESTERLY WINDS OF 30 TO 40 MPH...WHILE THE MET GUIDANCE IS WINDY...WITH WINDS MORE ON THE ORDER OF 15 TO 30 MPH. DIFFERENCES BETWEEN THE TWO GUIDANCE MEMBERS SEEM TO LIE WITH THE DEGREE OF MIXING AS WELL AS DIFFERENCES IN FCST HIGHS SUNDAY WITH THE MET GUIDANCE RUNNING 3 TO 7 DEGREES COOLER ON HIGHS. NO SURPRISE IT HAS THE SLOWER WINDS TOMORROW AFTERNOON. BUFKIT SOUNDINGS ARE HINTING AT ADVISORY CRITERIA WINDS TOMORROW AFTERNOON IN THE FAR NORTHERN COUNTIES WITH GUSTS TO OVER 45 MPH AROUND 18Z SUNDAY. IN LIGHT OF THE BUFKIT DATA...WOULD LIKE TO SEE BETTER AGREEMENT WITH THE MAV AND MET GUIDANCE BEFORE ISSUING ANY WIND HEADLINES FOR SUNDAY AFTERNOON. AFTER SUNDAY...FORECAST FOCUS SHIFTS TO A DEVELOPING STORM SYSTEM...WHICH HAS THE POTENTIAL TO SPREAD SIGNIFICANT SNOWS TO THE CENTRAL AND NORTHERN PLAINS TUESDAY INTO WEDNESDAY. BEGINNING MONDAY...THE UPPER PATTERN WILL BEGIN TO AMPLIFY ACROSS THE WESTERN CONUS. SURFACE HIGH PRESSURE WILL DROP SOUTH INTO THE UPPER MISSISSIPPI VALLEY...THEN THE SRN GREAT LAKES BY THE END OF THE DAY. SHALLOW ARCTIC AIR WILL BACK INTO THE AREA MONDAY...ONLY TO LIFT NORTH MONDAY NIGHT AS STRONG SRLY FLOW AND INTENSE WAA PUSHES NORTH FROM THE SRN PLAINS. TEMPS WILL BE VERY TRICKY ON MONDAY AND MONDAY NIGHT...AND CHOSE TO INCORPORATE A NON DIURNAL T FOR TEMPS LATE MONDAY INTO TUESDAY. AFTER TEMPS STRUGGLE TO GET OUT OF THE LWR 30S MONDAY...TEMPS WILL RISE INTO THE 30S AND LWR 40S OVERNIGHT AS INTENSE WARM AIR ADVECTION AND LOW LEVEL MOISTURE WORKS INTO THE REGION. OVERNIGHT LOWS SHOULD BE IN THE EARLY EVENING...WHILE HIGHS TUESDAY WILL BE EARLY WITH FALLING TEMPS EXPECTED IN THE AFTERNOON HOURS. NOW FOR PRECIPITATION...A LEAD DISTURBANCE WILL LIFT INTO WESTERN AND NORTH CENTRAL NEBRASKA MONDAY NIGHT...WHICH WILL LEAD TO INCREASED PRECIPITATION CHANCES. STRUGGLED A BIT WITH PRECIPITATION TYPE MONDAY NIGHT WITH SNOW AND RAIN SNOW MIX EXPECTED FIRST...FOLLOWED BY RAIN SHOWERS OVERNIGHT. WILL NEED TO TAKE A LOOK AT FREEZING RAIN POTENTIAL MONDAY EVENING AS WELL AS THE NAM TRIES TO HOLD ONTO A SHALLOW...SUBFREEZING LAYER IN THE EAST AND NORTHEAST. EVEN THE THREAT FOR AN ISOLATED THUNDERSTORM IS POSSIBLE IN THE SRN ZONES WITH NEGATIVE LI/S AND SB CAPES AROUND 200J/KG. PTYES...AS WELL AS SNOW ACCUMULATIONS ON THE BACK SIDE OF THE LOW LATE TUESDAY INTO TUESDAY NIGHT WILL HINGE HEAVILY ON MODEL CHOICE. THE NAM AND CANADIAN CONTINUE TO BE NORTH WITH THEIR TRACKS...THE ECMWF IS SOUTH AND THE GFS IS A COMPROMISE. IF THE ECMWF VERIFIES...OUR FAR NORTHERN ZONES COULD BE BURIED BY THIS SYSTEM...IF THE NAM VERIFIES...THE HEAVIEST SNOWS WOULD BE PUSHED WELL NORTH OF THE CWA. WITH A GFS/ECMWF COMPROMISE...OUR NORTHWESTERN AND FAR NORTHERN ZONES HAVE THE BEST POTENTIAL FOR SIGNIFICANT SNOWS OF 6+ INCHES. IN ADDITION TO SNOW...VERY STRONG WINDS WILL DEVELOP ON THE BACK SIDE OF THIS SYSTEM...LEADING TO THE POTENTIAL FOR BLIZZARD OR NEAR BLIZZARD CONDITIONS EVEN WITH ONLY A FEW INCHES OF SNOW. WILL CONTINUE TO HIGHLIGHT THE THREAT IN THE HWO AND...GIVEN THE ONGOING UNCERTAINTIES IN THE FORECAST TRACK...WILL NOT BE ISSUING ANY HEADLINES AT THIS POINT. LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...FOLLOWED CLOSER TO THE ECMWF FOR THE TUESDAY NIGHT PERIOD. ALL MODELS BRING STRONG NORTH TO NORTHWEST WINDS ACROSS THE AREA ON THE BACKSIDE OF A POWERFUL LOW PRESSURE SYSTEM. THE ECMWF IS THE MOST AGGRESSIVE WITH WRAP AROUND SNOW...AND GIVES SEVERAL INCHES OF ACCUMULATION ACROSS NORTH CENTRAL NEBRASKA. QUITE CONCERNED THAT EVEN JUST AN INCH OR TWO...LIKE THE GFS INDICATES...COULD GIVE SOME REAL VISIBILITY PROBLEMS DUE TO BLOWING SNOW. THE ECMWF WOULD BE THE WORST CASE SCENARIO...WITH SEVERAL INCHES ACCUMULATION PLUS THE STRONG WINDS. THIS SOLUTION WOULD BE NEAR BLIZZARD...AND WILL BEEF UP THE HAZARDOUS WEATHER OUTLOOK TO ACCOUNT FOR THIS POTENTIAL. SYSTEM QUICKLY DEPARTS TO THE EAST WEDNESDAY...BUT SOME BLOWING SNOW AND FLURRIES LIKELY TO LINGER INTO THE MORNING ACROSS NORTH CENTRAL NEBRASKA. RATHER UNSETTLED WEATHER WILL CONTINUE FOR LATE WEEK INTO NEXT WEEKEND. ANOTHER SYSTEM...CURRENTLY PROJECTED TO CROSS THE NORTHERN PLAINS...WILL DRAG A COLD FRONT THROUGH THE AREA A MAYBE A FEW SNOW SHOWERS THURSDAY NIGHT. AVIATION... STRONG GUSTY SOUTH SFC WINDS...AT TIMES GUSTING TO NEAR 30 KTS...WILL CONTINUE EARLY THIS EVENING. OTHERWISE VFR CONDITIONS EXPECTED...WITH SOME MID LEVEL CLOUDINESS ACROSS NORTH CENTRAL NEBRASKA. COLD FRONT CROSSES THE AREA BY LATE EVENING...WITH SFC WINDS SWITCHING FROM SSW TO WNW AT 15 TO 25 KTS. FIRE WEATHER...GUSTY WEST TO NORTHWEST WINDS WILL COMBINE WITH HUMIDITY VALUES OF 18 TO 25 PERCENT SUNDAY TO CREATE HIGH FIRE DANGER. AT THIS TIME WILL NOT ISSUE ANY FIRE WEATHER HEADLINES DUE TO RATHER COOL TEMPERATURES IN THE UPPER 30S AND 40S. WILL HOWEVER INCLUDE A SECTION ON HIGH FIRE DANGER IN THE HAZARDOUS WEATHER OUTLOOK. EVENING AND NIGHT SHIFTS CAN EVALUATE FURTHER AND DETERMINE IF A RED FLAG WARNING IS NECESSARY FOR SUNDAY. && .LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 4 AM CST /3 AM MST/ SUNDAY FOR NEZ004-022- 023-035-056>059-069>071-094. && $$ SHORT TERM/EXTENDED...MASEK AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
940 PM EST MON FEB 27 2012 .SYNOPSIS... A WEAK COLD FRONT WILL SLIDE THROUGH THE AREA LATE TONIGHT. HIGH PRESSURE REMAINING TO OUR NORTH WILL BRING WARMER TEMPERATURES WEDNESDAY. A WEAK COLD FRONT WILL BRING RAIN CHANCES WEDNESDAY NIGHT INTO THURSDAY. A STRONGER COLD FRONT IS EXPECTED ON SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 PM MONDAY...SURFACE WINDS HAVE SHIFTED NORTHWESTERLY ALONG THE HORRY COUNTY COASTLINE INDICATING THE SURFACE TROUGH HAS SLIPPED OFFSHORE THERE. WINDS IN THE CAPE FEAR REGION REMAIN FROM THE SOUTH OUT AHEAD OF THE TROUGH...BUT EVEN HERE WINDS SHOULD SHIFT NORTH OR NORTHWESTERLY WITHIN THE NEXT HOUR AS THE TROUGH SHIFTS OFFSHORE. RADAR COMPOSITES STILL SHOW A BROKEN AREA OF LIGHT RAIN EXTENDING ACROSS THE LOWER CAPE FEAR RIVER AREA AND MOVING EAST AROUND 15 MPH. ACTIVITY IS TIED TO ISENTROPIC LIFT ON THE 295K ISENTROPIC SURFACE...ALTHOUGH THE CHARACTER OF THE RADAR ECHOES ARE BECOMING MORE CONVECTIVE AS THE RAIN MOVES INTO A REGION WITH A DEEPER LAYER OF CONDITIONAL INSTABILITY. THE LATEST FEW RUNS OF THE HRRR ACTUALLY TURN THIS INTO A LINE OF HEAVY SHOWERS (IF NOT THUNDERSTORMS) IN SEVERAL HOURS ONCE THE ACTIVITY IS 20-40 MILES OFFSHORE. CLOUDS WILL REMAIN IN PLACE THROUGH MUCH OF THE NIGHT...ERODING ONLY LATE TONIGHT FROM THE NORTHWEST AS DRIER AIR MAKES ITS WAY SOUTH BEHIND A COLD FRONT BEING PUSHED THIS WAY BY HIGH PRESSURE OVER THE UPPER MIDWEST. NO CHANGES HAVE BEEN MADE TO FORECAST LOW TEMPERATURES OVERNIGHT...STILL EXPECTED TO REACH THE LOWER TO MIDDLE 40S FOR MOST AREAS...WITH SOME UPPER 40S AT THE IMMEDIATE COAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...DESPITE A WEAK WEDGE OF SURFACE HIGH PRESSURE PERSISTING ACROSS THE CAROLINAS TUESDAY WILL BRING AMPLE SUNSHINE AND WARMTH DUE TO MID LEVEL DRYING AND A BROAD LOW LEVEL HIGH ACROSS THE SOUTHEASTERN U.S AND BAHAMAS. MOISTURE ADVECTION IN THE LOW LEVELS WILL INCREASE CLOUD COVER TUESDAY NIGHT AS THE SURFACE WEDGE LIFTS OUT TO THE NORTHEAST. THIS WILL PAVE THE WAY FOR MORE ROBUST WARM ADVECTION ON WEDNESDAY PUSHING AFTERNOON TEMPERATURES INTO THE 70S. FIGURING OUT WHEN THIS ADVECTION OF MOISTURE LEADS TO MEASURABLE RAINFALL IS ALWAYS RATHER TOUGH ESPECIALLY IN SITUATIONS LIKE THIS ONE WHERE MID LEVEL FORCING FOR ASCENT IS NEARLY NEGLIGIBLE. ADDITIONALLY GUIDANCE IS OFTEN TOO QUICK TO INDICATE WHEN RAIN BREAKS OUT. CURRENT FORECAST SHOWS LOW RAIN CHANCES MOST OF WED NEAR SLIGHT CHANCE/CHANCE THRESHOLDS WITH INCREASING POPS WEDNESDAY NIGHT AS SOME WEAK HEIGHT FALLS FINALLY SPREAD ACROSS THE AREA. THERE IS STILL NO INDICATION THAT ANY DEEP VERTICAL MOTION MANAGES TO DEVELOP. THIS WILL BE IMPORTANT SINCE SOME ELEVATED INSTABILITY FORMS WED NIGHT AND LOW LEVEL WIND FIELDS GROW STRONG. SPC HAS OUTLINED A SLIGHT RISK IN DAY 3 OUTLOOKS BUT FEEL THAT CURRENT SEVERE RISK IS LOW ENOUGH TO ONLY WARRANT A MENTION IN THE HWO. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 3 PM MONDAY...MEDIUM RANGE MODELS REMAIN RELATIVELY STABLE THIS AFTERNOON. THE 0600 UTC GFS SUITE BRIEFLY ADOPTED A FASTER SOLUTION BUT THE 1200 UTC CYCLE HAS SLOWED DOWN AGAIN AND THIS IS THE SCENARIO HPC PREFERS. FOR THE SENSIBLE WEATHER ELEMENTS...EXTENDED POPS THROUGH THE OVERNIGHT SATURDAY/SUNDAY MORNING TIMEFRAME IS THE BIGGEST CHANGE. IF THE OPERATIONAL GFS VERIFIES...IT COULD BE A DECENT QPF EVENT AS THE AREA REMAINS IN A FAVORABLE AREA OF THE 300MB JET (RIGHT ENTRANCE REGION) FOR SEVERAL HOURS. WE SHOULD SEE A GLANCING SHOT OF ARCTIC AIR IN THE WAKE OF THE FRONT AND WITH THE POSSIBILITY OF A SECONDARY SHORTWAVE EMBEDDED IN THE PARENT TROUGH ROTATING THROUGH...BELOW FREEZING SURFACE TEMPERATURES ARE NOT EXPECTED...COURTESY OF A WELL MIXED BOUNDARY LAYER. TUESDAY MORNING IS WHEN...AT LEAST AT THIS POINT THE BEST RADIATIONAL CONDITIONS ARE EXPECTED. NO CHANGES TO THE REMAINDER OF THE FORECAST REGARDING TEMPERATURES WITH THURSDAY REMAINING THE MOST INTERESTING. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 00Z...A COASTAL/WARM FRONT IS CURRENTLY SITUATED BETWEEN THE THE COASTAL AND INLAND TERMINALS. THE FLO/LBT TERMINALS ARE ON THE COLD SIDE OF THE BOUNDARY AND ARE EXPERIENCING IFR/LIFR CEILINGS. ON THE WARM SIDE OF THE BOUNDARY THE COASTAL TERMINAL HAVE LOW VFR CEILINGS. LIGHT RAIN IS CONTINUING TO MOVE ACROSS THE TERMINALS WHICH IS RESULTING IN MVFR/IFR VISIBILITIES IN -RA/BR IN THE COLD AIR. LATEST MODELS SUGGEST THE BOUNDARY WILL SHIFT BACK THROUGH THE TERMINALS EARLY THIS EVENING SPREADING LIFR/IFR CONDITIONS INTO THE COASTAL TERMINALS. CONFIDENCE IS HIGH THIS WILL OCCUR BUT CONFIDENCE IN THE EXACT TIMING OF BOUNDARY PASSAGE IS ONLY LOW TO MODERATE. LOW CONDITIONS WILL THEN PERSIST AT ALL TERMINALS GENERALLY THROUGH 09-12Z...ALTHOUGH THERE ARE SOME INDICATIONS THAT CONDITIONS MAY LIFT TO MVFR OR BETTER AFTER 09Z. AFTER 13Z CONFIDENCE IS HIGH VFR CONDITIONS WILL PERSIST AT ALL TERMINALS THROUGH THE REMAINDER OF THE DAY. NORTHEAST WINDS WILL BECOME EAST TO SOUTHEAST BY AFTERNOON AS HIGH PRESSURE MOVES ACROSS TO THE NORTH THE TERMINALS. BY LATE AFTERNOON LOW LEVEL MOISTURE WILL BEGIN TO INCREASE AGAIN BY ANY CEILINGS ARE EXPECTED TO REMAIN VFR. EXTENDED OUTLOOK...A SLIGHT CHANCE FOR SHOWERS WEDNESDAY OVER THE NORTHERN PORTION OF THE REGION. A BETTER CHANCE FOR PRECIP WEDNESDAY NIGHT WITH A COLD FRONT. VFR THURSDAY. CHANCE OF RAIN CONTINUES FOR FRIDAY AND SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 930 PM MONDAY...THE SURFACE TROUGH HAS PUSHED BACK OFF THE SOUTH CAROLINA COASTLINE AS SHOWN BY WIND OBSERVATIONS FROM SPRINGMAID PIER IN MYRTLE BEACH OF NORTHWEST WINDS. ALONG THE CAPE FEAR COASTLINE THE TROUGH AXIS REMAINS JUST TO THE WEST WITH SOUTHERLY WINDS STILL NOTED AT MERCER PIER ON WRIGHTSVILLE BEACH. MODELS ARE VERY CONSISTENT BRINGING THE TROUGH AXIS COMPLETELY OFFSHORE DURING THE NEXT 1-2 HOURS WITH LIGHT NORTHERLY WINDS DEVELOPING ACROSS ALL OF OUR COASTAL WATERS. WIND SPEEDS WILL INCREASE LATE TONIGHT AS A COLD FRONT DROPS IN FROM THE NORTH. THIS FRONT...PUSHED BY HIGH PRESSURE OVER THE UPPER MIDWEST...WILL MAKE IT DOWN TO THE GEORGIA COAST TUESDAY BEFORE TURNING BACK AROUND LATER THIS WEEK. SEAS ARE RUNNING JUST A LITTLE HIGHER THAN ANTICIPATED BY ABOUT A FOOT AT THE FRYING PAN SHOALS BUOY. DATA FROM THE SUITE OF CORMP BUOYS IS UNAVAILABLE THIS EVENING...BUT WE HAVE RAISED SEAS ACROSS THE OUTER PORTION OF THE COASTAL WATERS BY ABOUT A FOOT THROUGH THE REMAINDER OF THE NIGHT. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...HIGH PRESSURE WILL BE IN PLACE ACROSS THE LANDMASS WHILE WEAK SURFACE TROUGH DEVELOPS WELL OFFSHORE. RESULT WILL BE A PINCHED NE GRADIENT WIND THAT COULD LEAD TO HIGH ENOUGH SEAS...3 TO 5 FT...THAT SCEC HEADLINES ARE NEEDED. WITH THE LIFTING OUT OF THE SURFACE HIGH TUESDAY NIGHT THE NE WIND WILL BEGIN TO VEER IN DIRECTION AND BY WED THIS WILL TRANSLATE TO A SOUTHERLY FLOW. SEAS WILL HAVE TO ADJUST TO THE NEW WIND DIRECTION BUT ONCE THIS OCCURS LATE WEDNESDAY INTO WEDNESDAY NIGHT THEY WILL BUILD FURTHER AND A SMALL CRAFT ADVISORY WILL BE NEEDED. LONG TERM/THURSDAY THROUGH SATURDAY/... AS OF 3 PM MONDAY...SOUTHWEST FLOW INITIALLY AS THE LONG ADVERTISED FRONT HAS SLOWED DOWN AND REMAINS TO THE WEST. WILL SEE A SUBTLE VEERING OF THE WINDS LATER THURSDAY AS THE FRONT FINALLY MOVES ACROSS. WINDS DIMINISH RAPIDLY BY FRIDAY MORNING AND TURN TO THE NORTHEAST AS HIGH PRESSURE BUILDS IN. A SUSTAINED AND SIGNIFICANT SOUTHERLY FLOW DEVELOPS EARLY SATURDAY AND CONTINUES THROUGH THE END OF THE PERIOD...THIS AHEAD OF THE NEXT SYSTEM. WILL EXPECT SMALL CRAFT CONDITIONS TO EXTEND INTO THE DAY THURSDAY AND TO BE HOISTED ONCE AGAIN FOR SATURDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...TRA NEAR TERM...TRA SHORT TERM...MBB LONG TERM...SHK AVIATION...MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
900 PM CST MON FEB 27 2012 .DISCUSSION... FORECAST CHALLENGE FOR THE EVENING WILL BE TEMPS IN THE IMMEDIATE SHORT TERM...THEN OBVIOUSLY THE UPCOMING WINTER STORM. TEMPS HAVE DROPPED OFF RATHER QUICKLY GIVEN THE FRESH SNOW...BUT DO EXPECT WARM ADVECTION TO START WITHIN NEXT COUPLE OF HOURS FROM SW TO NE. HAVE DROPPED TEMPS DOWN A GOOD 5 DEG...ESPECIALLY OVER NW MN WHERE THEY HAVE DROPPED THE FASTEST. EXPECT MOST AREAS TO SEE SINGLE DIGITS BY MIDNIGHT...THEN BEGIN A GRADUAL RISE. OTHER CONCERN IS WARM ADVECTION ASSOCIATED PRECIP. NAM AND RUC BOTH SHOWING DECENT H925 TO H850 WAA LAYER ENTERING SWRN ZONES BY 05Z...WITH HRRR REFLECTIVITIES PRODUCING SNOWFALL. INITIAL THOUGHT WAS WITH THE DRIER AIR OVER THE AREA...ASSOCIATED WITH SFC HIGH...IT WILL TAKE A WHILE TO SATURATE AND MAY NOT SEE MEASURABLE PRECIP. INITIAL REAL-TIME REFLECTIVITIES FROM ABR SUPPORT THIS...DRYING UP AS IT ENTERED OUR CWA ALTHOUGH BEGINNING TO SPREAD INTO AREA NOW. WHILE THE LOW POPS LOOK REASONABLE...MAY END UP SLOWING TIMING DOWN TO AROUND 09Z PRIOR TO SENDING UPDATE OUT...UNDECIDED AT THIS POINT. FOR UPCOMING STORM...00Z NAM CAME IN A BIT FURTHER NORTH AND FURTHER WEST THAN 18Z RUN...WITH SOME CHANGES IN PLACEMENT OF QPFS. HAVING LOOKED AT 18Z MODELS AND ONLY THE NEW NAM TO GO WITH...WILL KEEP WATCH IN PLACE (NO UPGRADES THIS SHIFT) AND ALLOW NIGHT SHIFT TO ASSESS THE LATEST EUROPEAN MODEL. DOES NOT LOOK LIKE SNOWFALL SIGNIFICANT ENOUGH TO IMPACT DRIVING WILL OCCUR UNTIL AFT 06Z WED...THUS STILL TIME TO ASSESS THE WIND (SEE PREV AFD) SITUATION AND MAKE THE RIGHT CALL ON BLIZZARD VERSUS WINTER STORM WARNING HEADLINES...ALTHOUGH I DO EXPECT ONE OR THE OTHER. && .AVIATION... VFR CONDS GRADUALLY BECOMING MVFR BY 12Z AS WARMER AIR IS USHERED IN FROM THE SW. MAY SEE SOME LIGHT SNOW ACROSS SOUTHERN VALLEY. CIGS SHOULD NOT GET INTO LOWER MVFR RANGE UNTIL TOMORROW AFTN...BEFORE DETERIORATING RAPIDLY TOMORROW EVENING AS A WINTER STORM MOVES INTO THE AREA. && .PREV DISCUSSION... /ISSUED 251 PM CST MON FEB 27 2012/ SHORT TERM... MAIN FORECAST CHALLENGE REMAINS THE UPCOMING TUE NIGHT/WED STORM SYSTEM. MODEL SOLUTIONS TODAY SEEM TO HAVE SWUNG BACK MORE TO A SLIGHTLY MORE NORTHWARD SOLUTION WHICH WOULD FAVOR SHIFTING THE SNOW BAND A LITTLE FURTHER NORTHWARD. WILL TRY TO ADJUST THE FORECAST ACCORDINGLY. MAIN QUESTIONS STILL CENTER ON THE DEGREE OF WIND DURING THE STORM. EXPECTING TO SEE WINTER STORM CRITERIA IN THE CURRENT WATCH AREA BUT NOT CERTAIN YET ON MEETING SUSTAINED/ FREQUENT GUSTS TO 35 MPH FOR BLIZZARD CRITERIA. THEREFORE AS THE EVENT IS STILL OVER 24 HOURS AWAY WILL HOLD ONTO WATCH PRODUCTS RATHER THAN MATCH ADJOINING OFFICES WITH WARNING PRODUCTS. TONIGHT...SEEING A LOT OF CIRRUS STREAMING NORTHEASTWARD THIS AFTERNOON AHEAD OF THE NEXT SYSTEM. SHOULD SEE QUITE A BIT OF CLOUD COVER OVERNIGHT WHICH WOULD HELP HOLD UP TEMPS. ALMOST LOOKS LIKE A NOCTURNAL TSTM SCENARIO TONIGHT IF THIS WAS ABOUT 4 MONTHS LATER. HAVE A STRONG LOW LEVEL JET FORMING AND STRONG WARM ADVECTION JUST OFF THE DECK. THE NOSE OF THESE FEATURES MOVE RIGHT THRU THE FA OVERNIGHT. MODELS LATCH ONTO THIS AND TRY TO FORM SOME PCPN OVERNIGHT. NOT SURE HOW EFFICIENT THIS WILL BE AT GETTING ANY PCPN TO THE SFC. A LOT OF IT MAY JUST WORK AT SATURATING THE ATMOSPHERE IN THE FORM OF VIRGA. GFS SHOWS THE MOST QPF WITH THIS BAND OF WARM ADVECTION BUT IT DOES TEND TO OVERDO WARM ADVECTION SCENARIOS. WILL HOLD OFF ON MENTIONING ANY PCPN UNTIL LATE AND KEEP IT IN THE FORM OF LIGHT SNOW. SFC WINDS MAY BE SLOW TO INCREASE. EVEN SO DO NOT THINK TEMPS WILL FAR OFF TOO FAR OVERNIGHT. TUE-THU...TUE STILL LOOKING LIKE A GOOD DAY INITIALLY WITH THE FIRST WAVE OF WARM ADVECTION AND THE LOW LEVEL JET HAVING PUSHED THRU. BIG STORM SYSTEM STILL LOOKS SLOW TO EVOLVE AND MOST OF THE EFFECTS WILL NOT GET GOING UNTIL AFTER 00Z WED. COULD BE SOME HEAVIER SNOW STARTING ACROSS THE FAR SOUTHERN FA BY MID TO LATE TUE AFTERNOON BUT WILL NOT PLAY AROUND WITH START TIMES ON THE WATCH FOR NOW. THERE HAVE JUST BEEN TOO MANY SWINGS WITH THE MODELS AND THE TREND HAS BEEN FOR SLOWING IT DOWN. STRONG SURGE OF LOW LEVEL JET GETS GOING AGAIN TUE NIGHT WITH PRECIPITABLE WATER VALUES ON THE RISE. ALL SAID LOOKS GOOD FOR HEAVY SNOW SETTING UP ACROSS THE FA ESPECIALLY ACROSS SOUTHEAST ND INTO WEST CENTRAL MN. SFC LOW SHOULD TRACK INTO SOUTHERN MN BY 12Z WED. THEREFORE FOR MOST OF TUE NIGHT SFC WINDS SHOULD STILL BE CROSS VALLEY. THIS MAY SUPPORT HIGHER WIND GUSTS ACROSS THE HIGHER ELEVATIONS WEST OF THE RED RIVER VALLEY BUT NOT EXPECTING THE MORE NORTHERLY WIND DIRECTIONS UNTIL AFTER 06Z WED INTO THE DAY WED. LIKE MENTIONED THERE HAS BEEN A FURTHER NORTHWARD SHIFT IN THE MODELS WITH THE HEAVIER SNOW. THIS STILL KEEPS SOUTHEAST ND INTO WEST CENTRAL MN WITH WELL OVER A FOOT OF SNOW. THE HIGHWAY 2 CORRIDOR COULD SEE 6 TO 8 INCHES. THEREFORE WILL ADD ON A TIER OF COUNTIES JUST NORTH OF THE CURRENT BLIZZARD WATCH AND GO WITH A WINTER STORM WATCH. DUE TO THE QUESTIONS ON WIND SPEEDS FOR THE STORM SYSTEM THINK THE WINTER STORM WATCH IS THE WAY TO GO FOR THIS ADDITIONAL STRIP OF COUNTIES. STORM SYSTEM SHOULD PUSH OFF ON WED NIGHT WITH THE REST OF THE SHORT TERM LOOKING UNEVENTFUL LONG TERM (FRI THRU MON)... THERE SHOULD BE AN UPPER TROUGH OVER THE REGION ON FRI...WITH THE CHANCE FOR SOME LIGHT SNOW. THEREAFTER EXPECT OVERALL DRY WEATHER WITH TEMPS NEAR NORMAL GIVEN THE FRESH/DEEP SNOWPACK THAT SHOULD BE OVER THE REGION BY THE END OF THIS WEEK. AVIATION... VFR CONDITIONS MAY FALL IT THE MVFR CATEGORY BY TUE AFTERNOON...AS MOISTURE INCREASES AHEAD OF APPROACHING STORM SYSTEM. WINDS WILL SHIFT TO A SOUTHERLY DIRECTION OVERNIGHT AND TURN MORE EASTERLY BY TUE AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...BLIZZARD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON FOR NDZ024-026>030-038-039-049-052-053. WINTER STORM WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON FOR NDZ014>016-054. MN...BLIZZARD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON FOR MNZ001>003-013>016-022>024-027>032-040. WINTER STORM WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY AFTERNOON FOR MNZ007>009-017. && $$ SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
942 AM CST SUN FEB 26 2012 .DISCUSSION... THE MAIN CHALLENGE WILL BE ONGOING HEADLINES TODAY INTO TONIGHT. WATER VAPOR SHOWS AN INTENSE SHORTWAVE MOVING INTO SOUTHERN ND. A DEFORMATION ZONE SNOW BAND IS COVERING MUCH OF THE REGION...WITH VARYING SNOW INTENSITIES. WHEN IT DOES SNOW VSBYS DROP INTO THE 3/4 TO 1/4SM RANGE WITH WINDS GUSTING TO 30 MPH AT TIMES. THIS IS MAKING OPEN COUNTRY TRAVEL DIFFICULT TODAY IN MOST AREAS. EXPECT A GRADUAL WEAKENING TREND TO THE DEFORMATION SNOW BAND TODAY AS THE UPPER LOW SLOWLY OPENS UP AND MOVES EAST. NORTHERLY WINDS WILL INCREASE THIS AFTERNOON WITH BLOWING AND DRIFTING SNOW CONTINUING INTO THIS EVENING AT LEAST. FOR NOW WILL LEAVE CURRENT HEADLINES ALONE...AND ADDRESS ONCE AGAIN THIS AFTERNOON. WILL TAKE A LOOK AT THE CURRENT GRIDS...WITH LITTLE CHANGE EXPECTED. SOME AREAS WILL NOT GET AS MUCH SNOW AS CURRENTLY ADVERTISED...BUT WITH HIGH VARIABILITY EXPECT MOST COUNTIES IN WARNED AREA TO GET AROUND 4 INCHES AND UP TO 6 POSSIBLE. && .AVIATION... HIGHLY VARIABLE CONDITIONS TODAY WITH LOW CONFIDENCE IN ANY ONE TIME PERIOD FORECAST. SNOW BANDS WILL GIVE IFR VSBYS AND MVFR CIGS TODAY BUT OUTSIDE OF BANDS VSBYS/CIGS MAY IMPROVE TO MVFR/VFR CONDITIONS. WINDS WILL BE GUSTY EASTERLY THEN TURN NORTHEAST TO NORTHERLY TODAY INTO TONIGHT AT 20 TO 30 KTS IN THE RED RIVER VALLEY AND EASTERN ND. A BIT LESS WIND SPEED IN BJI. && .PREV DISCUSSION... /ISSUED 708 AM CST SUN FEB 26 2012/ DISCUSSION... WATER VAPOR SHOWS WELL DEFINED UPPER LOW MOVING TOWARD THE MN/SD/MN BORDER REGION. AREA OF HEAVY SNOW KEEPS RE-DEVELOPING IN ROBERTS COUNTY SD AND MOVING INTO RICHLAND COUNTY AND EASTERN SARGENT/RANSOM COUNTIES. REPORT OF 3 INCHES AT LIDGERWOOD SO FAR AND RADAR SHOWS MODERATE TO HEAVY SNOW TO CONTINUE TO ANOTHER 1-3 HOURS. THUS WILL UPDATE THAT AREA TO A WARNING. PREV DISCUSSION... /ISSUED 354 AM CST SUN FEB 26 2012/ SHORT TERM... ANOTHER USUAL TRYING SNOW EVENT....THESE "HYBRID" STORMS COMING OFF THE PACIFIC THROUGH BRITISH COLUMBIA ALWAYS GIVES US FITS AND THIS IS NO EXCEPTION. DECENT FRONTOGENETIC FORCING OUT AHD OF SYSTEM CREATING SNOW BANDS....BUT DEEP LAYERED SATURATION JUST NOT ENOUGH TO CAUSE A LOT OF SNOW TO FALL. ISSUE TODAY WILL BE DEF ZONE SNOW AREA. INTERESTING WATER VAPOR PICTURE WITH ONE SHORT WAVE NORTHWEST OF BISMARCK AND THIS IS ASSOC WITH BAND OF SNOW WHICH HAS BEEN BTWN BIS/MOT MOST OF THE NIGHT. BAND OF SNOW HAS BEEN LOCATED FROM BTWN MOT/BIS SOUTHEAST INTO SOUTHEAST ND EARLY TONIGHT LIFTING NORTHWARD. THIS BAND PRODUCING SOME SPITS OF SNOW AT TIMES BUT NOTHING HEAVY. THE VORT MAX NORTHWEST OF BISMARCK IS BEGINNING TO COMBINE WITH SECOND AND MORE POWERFUL VORT MAX SNOW CLEARLY SEEN IN SOUTH DAKOTA SOUTHWEST OF ABERDEEN. RADAR SHOWING A SECOND BAND OF SNOW DEVELOPING AND LIFTING NORTHEAST AHD OF IT INTO SE ND. LATEST RUC LIFTS THIS 500 MB VORT NORTHEAST WITH UPPER LOW JUST EAST OF FARGO AT 15Z. RUC DEVELOPS BAND OF SNOW MORE INTENSELY 12Z-15Z JUST NORTH/NORTHWEST OF UPPER LOW FROM THIEF RIVER FALLS TO GRAND FORKS TO DEVILS LAKE THROUGH 18Z. THIS AXIS OF HEAVIER PRECIP 12-18Z ALSO SHOWN BY ECMWF. SLOWER SOLN AS SHOWN BY EARLIER ECMWF RUNS SEEMS TO BE WORKING OUT COMPARED TO FASTER GFS FROM A DAY AGO. THAT SAID... DO EXPECT SNOWFALL TO PICK UP IN A BROAD AREA FROM DVL TO GFK TO BJI SOUTH TO PKD-FAR-VCY 12Z-18Z PERIOD. NOW SNOWFALL AMTS MAY BE REAL TOUGH TO REACH PREV FCST OF 6 INCHES...THOUGH LOCAL AREAS SO FAR EARLY THIS MORNING HAS SEEN BRIEFLY HEAVIER SNOW. WILL TONE DOWN SNOWFALL TOTALS FROM EVENT TO 4-5 INCH WITH STILL CHC OF ISOLD 6 MARK IN WARNING AREA AND HOPE THAT MATERIALIZES. WILL KEEP WARNING OUT AS THERE IS SOME POTENTIAL FOR BLOWING SNOW ISSUES LATER TODAY AS SFC-925 MB WINDS LINK UP AND WINDS BLOW FROM THE NORTH DOWN THE VALLEY. 925 MB WINDS MAX OUT NR 30KTS WITH LITTLE LINKAGE ABV 900 MB. BUT IF THESE WINDS OCCUR THEN LOCAL WARNING CRITERIA OF 4/12 HR STILL REASONABLE. SYSTEM PULLS EAST TONIGHT BUT WINDS MAY HOLD UP TIL 06Z IN THE VALLEY AND LIGHT SNOW ENDS IN THE EAST BY 12Z. BREAK ON MONDAY WITH SOME CLEARING AND LIGHT WINDS. NEXT SYSTEM POISED TO BE A BIT SLOWER THAN PREV RUNS...WHICH ECMWF ONCE AGAIN HAS DONE A BIT BETTER JOB WITH TIMING WISE. LATEST INFO SUGGEST SNOW WILL SPREAD INTO NRN SD TUES MORNING AND THEN INTO SRN ND TUES AFTN-EVE. WILL ISSUE ANOTHER SPS AS WANT TO GET THROUGH WITH THIS STORM FIRST BEFORE HEADLINES FOR NEXT ONE. LONG TERM (WED-SAT)... MODELS IN GOOD AGREEMENT IN PLACEMENT OF THE 500MB LOW AT 12Z WED...BEGINNING TIME OF THE EXTENDED FORECAST...APPROX IN S MN ALONG 90 NEAR FAIRMONT. DEFORMATION SNOW ONGOING ACROSS THE SOUTHERN HALF OF THE FA ON WEDNESDAY. MODELS DEPICT AMPLE MOISTURE AVAILABLE WITH PWATS AROUND HALF AN INCH THROUGH WEDNESDAY YIELDING TOTAL PRECIP ACROSS THE SOUTHERN HALF OF THE FA RANGING FROM THREE QUARTERS OF AN INCH AROUND FARGO IN THE 00Z GFS TO UP TO TWO INCHES IN THE SISSETON HILLS ON THE 00Z ECMWF...EITHER WAY LEADING TO HEAVY AND SIGNIFICANT SNOWFALL TOTALS. MODELS HAVE COME INTO A BIT BETTER AGREEMENT IN HAVING A SHARP NRN EDGE TO SNOWFALL SOMEWHERE NEAR HIGHWAY 2 DURING THIS EVENT. ANOTHER LOW WILL MOVE ACROSS THE AREA THURSDAY NIGHT AND BRING SNOW CHANCES TO THE REGION. TEMPS FOR THE PERIOD EXPECTED TO CONTINUE TO BE BELOW NORMAL. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR NDZ006>008- 014>016-024-026>030-038-039-049-052>054. MN...WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR MNZ001>004-007- 029. WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR MNZ005-006-008- 009-013>017-022>024-027-028. WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ030>032-040. && $$ DK
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
708 AM CST SUN FEB 26 2012 .DISCUSSION... WATER VAPOR SHOWS WELL DEFINED UPPER LOW MOVING TOWARD THE MN/SD/MN BORDER REGION. AREA OF HEAVY SNOW KEEPS RE-DEVELOPING IN ROBERTS COUNTY SD AND MOVING INTO RICHLAND COUNTY AND EASTERN SARGENT/RANSOM COUNTIES. REPORT OF 3 INCHES AT LIDGERWOOD SO FAR AND RADAR SHOWS MODERATE TO HEAVY SNOW TO CONTINUE TO ANOTHER 1-3 HOURS. THUS WILL UPDATE THAT AREA TO A WARNING. && .PREV DISCUSSION... /ISSUED 354 AM CST SUN FEB 26 2012/ SHORT TERM... ANOTHER USUAL TRYING SNOW EVENT....THESE "HYBRID" STORMS COMING OFF THE PACIFIC THROUGH BRITISH COLUMBIA ALWAYS GIVES US FITS AND THIS IS NO EXCEPTION. DECENT FRONTOGENETIC FORCING OUT AHD OF SYSTEM CREATING SNOW BANDS....BUT DEEP LAYERED SATURATION JUST NOT ENOUGH TO CAUSE A LOT OF SNOW TO FALL. ISSUE TODAY WILL BE DEF ZONE SNOW AREA. INTERESTING WATER VAPOR PICTURE WITH ONE SHORT WAVE NORTHWEST OF BISMARCK AND THIS IS ASSOC WITH BAND OF SNOW WHICH HAS BEEN BTWN BIS/MOT MOST OF THE NIGHT. BAND OF SNOW HAS BEEN LOCATED FROM BTWN MOT/BIS SOUTHEAST INTO SOUTHEAST ND EARLY TONIGHT LIFTING NORTHWARD. THIS BAND PRODUCING SOME SPITS OF SNOW AT TIMES BUT NOTHING HEAVY. THE VORT MAX NORTHWEST OF BISMARCK IS BEGINNING TO COMBINE WITH SECOND AND MORE POWERFUL VORT MAX SNOW CLEARELY SEEN IN SOUTH DAKOTA SOUTHWEST OF ABERDEEN. RADAR SHOWING A SECOND BAND OF SNOW DEVELOPING AND LIFTING NORTHEAST AHD OF IT INTO SE ND. LATEST RUC LIFTS THIS 500 MB VORT NORTHEAST WITH UPPER LOW JUST EAST OF FARGO AT 15Z. RUC DEVELOPS BAND OF SNOW MORE INTENSELY 12Z-15Z JUST NORTH/NORTHWEST OF UPPER LOW FROM THIEF RIVER FALLS TO GRAND FORKS TO DEVILS LAKE THROUGH 18Z. THIS AXIS OF HEAVIER PRECIP 12-18Z ALSO SHOWN BY ECMWF. SLOWER SOLN AS SHOWN BY EARLIER ECMWF RUNS SEEMS TO BE WORKING OUT COMPARED TO FASTER GFS FROM A DAY AGO. THAT SAID... DO EXPECT SNOWFALL TO PICK UP IN A BROAD AREA FROM DVL TO GFK TO BJI SOUTH TO PKD-FAR-VCY 12Z-18Z PERIOD. NOW SNOWFALL AMTS MAY BE REAL TOUGH TO REACH PREV FCST OF 6 INCHES...THOUGH LOCAL AREAS SO FAR EARLY THIS MORNING HAS SEEN BRIEFLY HEAVIER SNOW. WILL TONE DOWN SNOWFALL TOTALS FROM EVENT TO 4-5 INCH WITH STILL CHC OF ISOLD 6 MARK IN WARNING AREA AND HOPE THAT MATERIALIZES. WILL KEEP WARNING OUT AS THERE IS SOME POTENTIAL FOR BLOWING SNOW ISSUES LATER TODAY AS SFC-925 MB WINDS LINK UP AND WINDS BLOW FROM THE NORTH DOWN THE VALLEY. 925 MB WINDS MAX OUT NR 30KTS WITH LITTLE LINKAGE ABV 900 MB. BUT IF THESE WINDS OCCUR THEN LOCAL WARNING CRITERIA OF 4/12 HR STILL REASONABLE. SYSTEM PULLS EAST TONIGHT BUT WINDS MAY HOLD UP TIL 06Z IN THE VALLEY AND LIGHT SNOW ENDS IN THE EAST BY 12Z. BREAK ON MONDAY WITH SOME CLEARING AND LIGHT WINDS. NEXT SYSTEM POISED TO BE A BIT SLOWER THAN PREV RUNS...WHICH ECMWF ONCE AGAIN HAS DONE A BIT BETTER JOB WITH TIMING WISE. LATEST INFO SUGGEST SNOW WILL SPREAD INTO NRN SD TUES MORNING AND THEN INTO SRN ND TUES AFTN-EVE. WILL ISSUE ANOTHER SPS AS WANT TO GET THROUGH WITH THIS STORM FIRST BEFORE HEADLINES FOR NEXT ONE. LONG TERM (WED-SAT)... MODELS IN GOOD AGREEMENT IN PLACEMENT OF THE 500MB LOW AT 12Z WED...BEGINNING TIME OF THE EXTENDED FORECAST...APPROX IN S MN ALONG 90 NEAR FAIRMONT. DEFORMATION SNOW ONGOING ACROSS THE SOUTHERN HALF OF THE FA ON WEDNESDAY. MODELS DEPICT AMPLE MOISTURE AVAILABLE WITH PWATS AROUND HALF AN INCH THROUGH WEDNESDAY YIELDING TOTAL PRECIP ACROSS THE SOUTHERN HALF OF THE FA RANGING FROM THREE QUARTERS OF AN INCH AROUND FARGO IN THE 00Z GFS TO UP TO TWO INCHES IN THE SISSETON HILLS ON THE 00Z ECMWF...EITHER WAY LEADING TO HEAVY AND SIGNIFICANT SNOWFALL TOTALS. MODELS HAVE COME INTO A BIT BETTER AGREEMENT IN HAVING A SHARP NRN EDGE TO SNOWFALL SOMEWHERE NEAR HIGHWAY 2 DURING THIS EVENT. ANOTHER LOW WILL MOVE ACROSS THE AREA THURSDAY NIGHT AND BRING SNOW CHANCES TO THE REGION. TEMPS FOR THE PERIOD EXPECTED TO CONTINUE TO BE BELOW NORMAL. AVIATION... HIGHLY VARIABLE CONDITIONS TODAY WITH LOW CONFIDENCE IN ANY ONE TIME PERIOD FOREAST. SNOW BANDS WILL GIVE IFR VSBYS AND MVFR CIGS TODAY BUT OUTSIDE OF BANDS VSBYS/CIGS MAY IMPROVE TO MVFR/VFR CONDITIONS. WINDS WILL BE GUSTY EASTERLY THEN TURN NORTHEAST TO NORTHERLY TODAY INTO TONIGHT AT 20 TO 30 KTS IN THE RED RIVER VALLEY AND EASTERN ND. A BIT LESS WIND SPEED IN BJI. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR NDZ006>008- 014>016-024-026>030-038-039-049-052>054. MN...WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR MNZ001>004-007- 029. WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR MNZ005-006-008- 009-013>017-022>024-027-028. WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ030>032-040. && $$ RIDDLE/JK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
354 AM CST SUN FEB 26 2012 .SHORT TERM... ANOTHER USUAL TRYING SNOW EVENT....THESE "HYBRID" STORMS COMING OFF THE PACIFIC THROUGH BRITISH COLUMBIA ALWAYS GIVES US FITS AND THIS IS NO EXCEPTION. DECENT FRONTOGENETIC FORCING OUT AHD OF SYSTEM CREATING SNOW BANDS....BUT DEEP LAYERED SATURATION JUST NOT ENOUGH TO CAUSE A LOT OF SNOW TO FALL. ISSUE TODAY WILL BE DEF ZONE SNOW AREA. INTERESTING WATER VAPOR PICTURE WITH ONE SHORT WAVE NORTHWEST OF BISMARCK AND THIS IS ASSOC WITH BAND OF SNOW WHICH HAS BEEN BTWN BIS/MOT MOST OF THE NIGHT. BAND OF SNOW HAS BEEN LOCATED FROM BTWN MOT/BIS SOUTHEAST INTO SOUTHEAST ND EARLY TONIGHT LIFTING NORTHWARD. THIS BAND PRODUCING SOME SPITS OF SNOW AT TIMES BUT NOTHING HEAVY. THE VORT MAX NORTHWEST OF BISMARCK IS BEGINNING TO COMBINE WITH SECOND AND MORE POWERFUL VORT MAX SNOW CLEARELY SEEN IN SOUTH DAKOTA SOUTHWEST OF ABERDEEN. RADAR SHOWING A SECOND BAND OF SNOW DEVELOPING AND LIFTING NORTHEAST AHD OF IT INTO SE ND. LATEST RUC LIFTS THIS 500 MB VORT NORTHEAST WITH UPPER LOW JUST EAST OF FARGO AT 15Z. RUC DEVELOPS BAND OF SNOW MORE INTENSELY 12Z-15Z JUST NORTH/NORTHWEST OF UPPER LOW FROM THIEF RIVER FALLS TO GRAND FORKS TO DEVILS LAKE THROUGH 18Z. THIS AXIS OF HEAVIER PRECIP 12-18Z ALSO SHOWN BY ECMWF. SLOWER SOLN AS SHOWN BY EARLIER ECMWF RUNS SEEMS TO BE WORKING OUT COMPARED TO FASTER GFS FROM A DAY AGO. THAT SAID... DO EXPECT SNOWFALL TO PICK UP IN A BROAD AREA FROM DVL TO GFK TO BJI SOUTH TO PKD-FAR-VCY 12Z-18Z PERIOD. NOW SNOWFALL AMTS MAY BE REAL TOUGH TO REACH PREV FCST OF 6 INCHES...THOUGH LOCAL AREAS SO FAR EARLY THIS MORNING HAS SEEN BRIEFLY HEAVIER SNOW. WILL TONE DOWN SNOWFALL TOTALS FROM EVENT TO 4-5 INCH WITH STILL CHC OF ISOLD 6 MARK IN WARNING AREA AND HOPE THAT MATERIALIZES. WILL KEEP WARNING OUT AS THERE IS SOME POTENTIAL FOR BLOWING SNOW ISSUES LATER TODAY AS SFC-925 MB WINDS LINK UP AND WINDS BLOW FROM THE NORTH DOWN THE VALLEY. 925 MB WINDS MAX OUT NR 30KTS WITH LITTLE LINKAGE ABV 900 MB. BUT IF THESE WINDS OCCUR THEN LOCAL WARNING CRITERIA OF 4/12 HR STILL REASONABLE. SYSTEM PULLS EAST TONIGHT BUT WINDS MAY HOLD UP TIL 06Z IN THE VALLEY AND LIGHT SNOW ENDS IN THE EAST BY 12Z. BREAK ON MONDAY WITH SOME CLEARING AND LIGHT WINDS. NEXT SYSTEM POISED TO BE A BIT SLOWER THAN PREV RUNS...WHICH ECMWF ONCE AGAIN HAS DONE A BIT BETTER JOB WITH TIMING WISE. LATEST INFO SUGGEST SNOW WILL SPREAD INTO NRN SD TUES MORNING AND THEN INTO SRN ND TUES AFTN-EVE. WILL ISSUE ANOTHER SPS AS WANT TO GET THROUGH WITH THIS STORM FIRST BEFORE HEADLINES FOR NEXT ONE. .LONG TERM (WED-SAT)... MODELS IN GOOD AGREEMENT IN PLACEMENT OF THE 500MB LOW AT 12Z WED...BEGINNING TIME OF THE EXTENDED FORECAST...APPROX IN S MN ALONG 90 NEAR FAIRMONT. DEFORMATION SNOW ONGOING ACROSS THE SOUTHERN HALF OF THE FA ON WEDNESDAY. MODELS DEPICT AMPLE MOISTURE AVAILABLE WITH PWATS AROUND HALF AN INCH THROUGH WEDNESDAY YIELDING TOTAL PRECIP ACROSS THE SOUTHERN HALF OF THE FA RANGING FROM THREE QUARTERS OF AN INCH AROUND FARGO IN THE 00Z GFS TO UP TO TWO INCHES IN THE SISSETON HILLS ON THE 00Z ECMWF...EITHER WAY LEADING TO HEAVY AND SIGNIFICANT SNOWFALL TOTALS. MODELS HAVE COME INTO A BIT BETTER AGREEMENT IN HAVING A SHARP NRN EDGE TO SNOWFALL SOMEWHERE NEAR HIGHWAY 2 DURING THIS EVENT. ANOTHER LOW WILL MOVE ACROSS THE AREA THURSDAY NIGHT AND BRING SNOW CHANCES TO THE REGION. TEMPS FOR THE PERIOD EXPECTED TO CONTINUE TO BE BELOW NORMAL. && && .AVIATION... HIGHLY VARIABLE CONDITIONS TODAY WITH LOW CONFIDENCE IN ANY ONE TIME PERIOD FOREAST. SNOW BANDS WILL GIVE IFR VSBYS AND MVFR CIGS TODAY BUT OUTSIDE OF BANDS VSBYS/CIGS MAY IMPROVE TO MVFR/VFR CONDITIONS. WINDS WILL BE GUSTY EASTERLY THEN TURN NORTHEAST TO NORTHERLY TODAY INTO TONIGHT AT 20 TO 30 KTS IN THE RED RIVER VALLEY AND EASTERN ND. A BIT LESS WIND SPEED IN BJI. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY UNTIL 3 AM CST MONDAY FOR NDZ049-052-053. WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR NDZ006>008- 014>016-024-026>030-038-039-054. MN...WINTER WEATHER ADVISORY UNTIL 3 AM CST MONDAY FOR MNZ029. WINTER STORM WARNING UNTIL 6 AM CST MONDAY FOR MNZ005-006-008- 009-013>017-022>024-027-028. WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ030>032-040. WINTER STORM WARNING UNTIL 3 AM CST MONDAY FOR MNZ001>004-007. && $$ RIDDLE/KAISER
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
930 PM EST MON FEB 27 2012 .SYNOPSIS... HIGH PRESSURE TO THE WEST WILL QUICKLY BUILD EAST OVER THE AREA TONIGHT. THE HIGH WILL MOVE TO THE EAST COAST BY LATE TUESDAY. ANOTHER STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE CENTRAL GREAT LAKES WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... TWEAKED CLOUD COVER AS CLOUDS OVER SE LOWER MICHIGAN BEGINNING TO ERODE. TWEAKED OVERNIGHT LOWS DOWN A DEGREE OR TWO. PREVIOUS DISCUSSION... BIG ISSUE IN THE SHORT TERM WILL BE THE WINDS THIS EVENING IN RESPONSE TO A RATHER TIGHT GRADIENT BETWEEN LOW PRESSURE OVER THE NORTHERN GREAT LAKES AND STRONG HIGH PRESSURE OVER THE PLAINS QUICKLY BUILDING TOWARD THE AREA. HAVE EXPANDED THE WIND ADVISORY ACROSS EASTERN COUNTIES WITH EXCEPTION FOR THE FAR SOUTH THROUGH THIS EVENING. HRRR MODEL RUNS HAVE BEEN HANDLING THE WINDS RATHER WELL THIS AFTERNOON...AND THEY HAVE ADVISORY WIND GUSTS PUSHING THROUGH NORTHEAST OHIO COUNTIES OVER THE NEXT SEVERAL HOURS. WINDS SHOULD DIMINISH QUICKLY FROM WEST TO EAST ESPECIALLY AFTER SUNSET TONIGHT. AFTER MIDNIGHT EXPECTING WINDS TO BE DOWN BELOW 10 MPH. ASIDE FROM THAT A DRY AND MOSTLY CLEAR NIGHT EXPECTED WITH TEMPS DROPPING BACK TO THE LOWER TO MID 20S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... HIGH PRESSURE OVER THE AREA TUESDAY MORNING...THEN MOVING TO THE EAST WILL ALLOW FOR A QUIET AND DRY WEATHER DAY WITH SEASONABLE TEMPERATURES. LATEST MODELS SEEM TO BE DELAYING THE ONSET OF THE PRECIP ACROSS THE AREA TUESDAY NIGHT. WHILE CLOUDS ARE EXPECTED TO OVERSPREAD THE REGION EARLY ON...THINKING PERHAPS NOT TOWARD 06Z ACROSS THE SOUTHWEST AREAS AND NOT UNTIL CLOSE TO 12Z WED FOR PRECIP ACROSS NW PA. DO BRING UP POPS QUICKLY ACROSS THE AREA THOUGH AFTER 06Z. STILL SOME QUESTION AS TO PRECIP TYPE AT THE ONSET ESPECIALLY FROM CLE-CAK NORTHEAST. ACROSS OH THINKING THAT THERE MAY BE A RAIN/SNOW MIX WITH BEST CONFIDENCE OF ALL SNOW AT THE ONSET FOR FAR NE OH AND NW PA. MODELS SHOWING LOWER LEVELS WARMING UP ENOUGH BY 12Z WED THOUGH THAT MANY LOCATIONS WILL SWITCH OVER TO RAIN. MODELS LEANING TOWARD A MORE NORTHERN TRACK OF THE LOW CENTER ALLOWING MUCH OF THE AREA TO GET WARM ON WED. LEFT THE HIGH POPS AND MENTION OF THUNDER IN THE MORNING...BUT THEN CONCERNED ABOUT DRY SLOT MOVING ESPECIALLY INTO WESTERN AREAS FOR THE AFTERNOON SO REDUCED POPS AND CLOUDS A BIT ACROSS THE WEST. TEMPS WILL ALSO BE TRICKIEST DURING WED SO FOR NOW USED A BLEND OF MAV AND MET NUMBERS. CONCERNED MOST ABOUT NORTHERN AREAS WHICH MAY GET WARMER THAN FORECAST. ALSO CONCERNED ABOUT WIND POTENTIAL ON WED ESPECIALLY ACROSS THE WEST WHERE BETTER MIXING IS POSSIBLE. LOW PRESSURE NORTH OF THE AREA WEDNESDAY NIGHT AND THROUGH MUCH OF THURSDAY WILL ALLOW FOR SOME RAIN/SNOW SHOWERS MAINLY ACROSS THE NORTH WEDNESDAY NIGHT...THEN CONTINUED CHANCES FOR SHOWERS ACROSS NE OH AND NW PA THROUGH MUCH OF THURSDAY. HIGH PRESSURE RIDGING IN WILL DRY OUT THE AREA THURSDAY NIGHT. && .LONG TERM /FRIDAY THROUGH MONDAY/... SOUTHERLY WINDS WILL BE ON THE INCREASE ON FRIDAY AS LOW PRESSURE MOVES FROM THE CENTRAL PLAINS TO THE CENTRAL GREAT LAKES BY FRIDAY EVENING. THIS WILL PROVIDE WARM CONDITIONS FOR THE REGION WITH HIGHS INTO THE 50S FOR MOST LOCATIONS. RAIN CHANCES WILL BE ON THE INCREASE FRIDAY EVENING INTO THE OVERNIGHT. SOME RAIN MAY LINGER INTO SATURDAY MORNING. COOLER AIR WILL SPILL ACROSS THE LAKE SATURDAY NIGHT INTO EARLY SUNDAY AND COULD BE JUST COLD ENOUGH TO PROVIDE A FEW SNOW SHOWERS OFF OF LAKE ERIE. ANOTHER FAST MOVING STORM SYSTEM MAY AFFECT THE REGION SUNDAY NIGHT AND MAY ENHANCE ANY SNOW SHOWERS THAT ARE IN THE AREA. SLIGHTLY COOLER ON SATURDAY WITH HIGHS BACK INTO THE 40S. EVEN COOLER BY SUNDAY INTO MONDAY WITH HIGHS AT MOST LOCATIONS WITHIN A COUPLE DEGREES OF 40. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... ENDED WIND ADVISORY FOR ENTIRE AREA. WINDS HAVE DROPPED OFF SIGNIFICANTLY BEHIND THE FRONT WITH SUSTAIND WINDS IN THE 20S AND MAX GUSTS ONLY INTO THE LOWER 30S. PREVIOUS DISCUSSION... HIGH PRESSURE WILL CONTINUE TO BUILD IN ACROSS THE AREA OVERNIGHT BEHIND A COLD FRONT NOW EAST OF THE AREA. MOISTURE BETWEEN 2 AND 3 KFT OVER SRN LWR MI ON THE BACK SIDE OF THE ASSOCIATED SURFACE LOW MOVING ESE TOWARD THE AREA BUT IR SATELLITE LOOP SHOWS THE CLOUDS DISSIPATING AS THEY APPROACH. THE CLOUDS DID MANAGE TO GET INTO KTOL AND STILL BELIEVE THEY WILL GET INTO KCLE AND KERI THROUGH THE EVENING HOURS HOWEVER FOR NOW WILL NOT EXPECT ANY RESTRICTION. WINDS REMAIN GUSTY AT 23Z HOWEVER THEY HAVE BEEN DIMINISHING OVER THE PAST HOUR. THROUGH THE EVENING EXPECT WINDS TO DIMINISH RAPIDLY AS LOW LEVELS DECOUPLE. TUESDAY EXPECT SO HIGH LEVEL MOISTURE MOVING IN BUT EXPECT CIGS TO REMAIN VFR ABOVE BKN- OVC120-150. OUTLOOK...PERIODS OF NON-VFR WILL RETURN TUESDAY NIGHT AND CONTINUE AT TIMES THROUGH THURSDAY. NON-VFR MAY RETURN BY FRIDAY NIGHT INTO SATURDAY. && .MARINE... A COLD FRONT MOVING ACROSS LAKE ERIE THIS AFTERNOON IS RESPONSIBLE FOR STRONG WESTERLY WINDS OF 20 TO 30 KNOTS. WINDS ARE APPROACHING GALE FORCE ON THE EAST END OF THE LAKE BUT SHOULD REMAIN JUST BELOW GIVEN THAT THE COLD ADVECTION BEHIND THE FRONT IS NOT THAT STRONG. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL NEARSHORE WATERS AND WILL COME TO AN END FROM WEST TO EAST OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD AND WINDS/WAVES QUICKLY DECREASE. EASTERLY WINDS WILL INCREASE ON TUESDAY NIGHT AHEAD OF THE NEXT LOW PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. WE WILL HAVE TO MONITOR THE EXACT TRACK AND STRENGTH OF THE SURFACE LOW FROM WEDNESDAY INTO THURSDAY TO DETERMINE MOST LIKELY WINDOW OF SMALL CRAFT ADVISORY CONDITIONS. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED ON THE EAST END OF THE LAKE FOR THURSDAY BUT MAY NEED TO BE EXPANDED TO THE WEST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR LEZ144>149. && $$ SYNOPSIS...ABE NEAR TERM...ABE SHORT TERM...ABE/DJB LONG TERM...MULLEN AVIATION...TK MARINE...KEC
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
624 PM EST MON FEB 27 2012 .SYNOPSIS... HIGH PRESSURE TO THE WEST WILL QUICKLY BUILD EAST OVER THE AREA TONIGHT. THE HIGH WILL MOVE TO THE EAST COAST BY LATE TUESDAY. ANOTHER STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE CENTRAL GREAT LAKES WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... BIG ISSUE IN THE SHORT TERM WILL BE THE WINDS THIS EVENING IN RESPONSE TO A RATHER TIGHT GRADIENT BETWEEN LOW PRESSURE OVER THE NORTHERN GREAT LAKES AND STRONG HIGH PRESSURE OVER THE PLAINS QUICKLY BUILDING TOWARD THE AREA. HAVE EXPANDED THE WIND ADVISORY ACROSS EASTERN COUNTIES WITH EXCEPTION FOR THE FAR SOUTH THROUGH THIS EVENING. HRRR MODEL RUNS HAVE BEEN HANDLING THE WINDS RATHER WELL THIS AFTERNOON...AND THEY HAVE ADVISORY WIND GUSTS PUSHING THROUGH NORTHEAST OHIO COUNTIES OVER THE NEXT SEVERAL HOURS. WINDS SHOULD DIMINISH QUICKLY FROM WEST TO EAST ESPECIALLY AFTER SUNSET TONIGHT. AFTER MIDNIGHT EXPECTING WINDS TO BE DOWN BELOW 10 MPH. ASIDE FROM THAT A DRY AND MOSTLY CLEAR NIGHT EXPECTED WITH TEMPS DROPPING BACK TO THE LOWER TO MID 20S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... HIGH PRESSURE OVER THE AREA TUESDAY MORNING...THEN MOVING TO THE EAST WILL ALLOW FOR A QUIET AND DRY WEATHER DAY WITH SEASONABLE TEMPERATURES. LATEST MODELS SEEM TO BE DELAYING THE ONSET OF THE PRECIP ACROSS THE AREA TUESDAY NIGHT. WHILE CLOUDS ARE EXPECTED TO OVERSPREAD THE REGION EARLY ON...THINKING PERHAPS NOT TOWARD 06Z ACROSS THE SOUTHWEST AREAS AND NOT UNTIL CLOSE TO 12Z WED FOR PRECIP ACROSS NW PA. DO BRING UP POPS QUICKLY ACROSS THE AREA THOUGH AFTER 06Z. STILL SOME QUESTION AS TO PRECIP TYPE AT THE ONSET ESPECIALLY FROM CLE-CAK NORTHEAST. ACROSS OH THINKING THAT THERE MAY BE A RAIN/SNOW MIX WITH BEST CONFIDENCE OF ALL SNOW AT THE ONSET FOR FAR NE OH AND NW PA. MODELS SHOWING LOWER LEVELS WARMING UP ENOUGH BY 12Z WED THOUGH THAT MANY LOCATIONS WILL SWITCH OVER TO RAIN. MODELS LEANING TOWARD A MORE NORTHERN TRACK OF THE LOW CENTER ALLOWING MUCH OF THE AREA TO GET WARM ON WED. LEFT THE HIGH POPS AND MENTION OF THUNDER IN THE MORNING...BUT THEN CONCERNED ABOUT DRY SLOT MOVING ESPECIALLY INTO WESTERN AREAS FOR THE AFTERNOON SO REDUCED POPS AND CLOUDS A BIT ACROSS THE WEST. TEMPS WILL ALSO BE TRICKIEST DURING WED SO FOR NOW USED A BLEND OF MAV AND MET NUMBERS. CONCERNED MOST ABOUT NORTHERN AREAS WHICH MAY GET WARMER THAN FORECAST. ALSO CONCERNED ABOUT WIND POTENTIAL ON WED ESPECIALLY ACROSS THE WEST WHERE BETTER MIXING IS POSSIBLE. LOW PRESSURE NORTH OF THE AREA WEDNESDAY NIGHT AND THROUGH MUCH OF THURSDAY WILL ALLOW FOR SOME RAIN/SNOW SHOWERS MAINLY ACROSS THE NORTH WEDNESDAY NIGHT...THEN CONTINUED CHANCES FOR SHOWERS ACROSS NE OH AND NW PA THROUGH MUCH OF THURSDAY. HIGH PRESSURE RIDGING IN WILL DRY OUT THE AREA THURSDAY NIGHT. && .LONG TERM /FRIDAY THROUGH MONDAY/... SOUTHERLY WINDS WILL BE ON THE INCREASE ON FRIDAY AS LOW PRESSURE MOVES FROM THE CENTRAL PLAINS TO THE CENTRAL GREAT LAKES BY FRIDAY EVENING. THIS WILL PROVIDE WARM CONDITIONS FOR THE REGION WITH HIGHS INTO THE 50S FOR MOST LOCATIONS. RAIN CHANCES WILL BE ON THE INCREASE FRIDAY EVENING INTO THE OVERNIGHT. SOME RAIN MAY LINGER INTO SATURDAY MORNING. COOLER AIR WILL SPILL ACROSS THE LAKE SATURDAY NIGHT INTO EARLY SUNDAY AND COULD BE JUST COLD ENOUGH TO PROVIDE A FEW SNOW SHOWERS OFF OF LAKE ERIE. ANOTHER FAST MOVING STORM SYSTEM MAY AFFECT THE REGION SUNDAY NIGHT AND MAY ENHANCE ANY SNOW SHOWERS THAT ARE IN THE AREA. SLIGHTLY COOLER ON SATURDAY WITH HIGHS BACK INTO THE 40S. EVEN COOLER BY SUNDAY INTO MONDAY WITH HIGHS AT MOST LOCATIONS WITHIN A COUPLE DEGREES OF 40. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... ENDED WIND ADVISORY FOR ENTIRE AREA. WINDS HAVE DROPPED OFF SIGNIFICANTLY BEHIND THE FRONT WITH SUSTAIND WINDS IN THE 20S AND MAX GUSTS ONLY INTO THE LOWER 30S. PREVIOUS DISCUSSION... HIGH PRESSURE WILL CONTINUE TO BUILD IN ACROSS THE AREA OVERNIGHT BEHIND A COLD FRONT NOW EAST OF THE AREA. MOISTURE BETWEEN 2 AND 3 KFT OVER SRN LWR MI ON THE BACK SIDE OF THE ASSOCIATED SURFACE LOW MOVING ESE TOWARD THE AREA BUT IR SATELLITE LOOP SHOWS THE CLOUDS DISSIPATING AS THEY APPROACH. THE CLOUDS DID MANAGE TO GET INTO KTOL AND STILL BELIEVE THEY WILL GET INTO KCLE AND KERI THROUGH THE EVENING HOURS HOWEVER FOR NOW WILL NOT EXPECT ANY RESTRICTION. WINDS REMAIN GUSTY AT 23Z HOWEVER THEY HAVE BEEN DIMINISHING OVER THE PAST HOUR. THROUGH THE EVENING EXPECT WINDS TO DIMINISH RAPIDLY AS LOW LEVELS DECOUPLE. TUESDAY EXPECT SO HIGH LEVEL MOISTURE MOVING IN BUT EXPECT CIGS TO REMAIN VFR ABOVE BKN- OVC120-150. OUTLOOK...PERIODS OF NON-VFR WILL RETURN TUESDAY NIGHT AND CONTINUE AT TIMES THROUGH THURSDAY. NON-VFR MAY RETURN BY FRIDAY NIGHT INTO SATURDAY. && .MARINE... A COLD FRONT MOVING ACROSS LAKE ERIE THIS AFTERNOON IS RESPONSIBLE FOR STRONG WESTERLY WINDS OF 20 TO 30 KNOTS. WINDS ARE APPROACHING GALE FORCE ON THE EAST END OF THE LAKE BUT SHOULD REMAIN JUST BELOW GIVEN THAT THE COLD ADVECTION BEHIND THE FRONT IS NOT THAT STRONG. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL NEARSHORE WATERS AND WILL COME TO AN END FROM WEST TO EAST OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD AND WINDS/WAVES QUICKLY DECREASE. EASTERLY WINDS WILL INCREASE ON TUESDAY NIGHT AHEAD OF THE NEXT LOW PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. WE WILL HAVE TO MONITOR THE EXACT TRACK AND STRENGTH OF THE SURFACE LOW FROM WEDNESDAY INTO THURSDAY TO DETERMINE MOST LIKELY WINDOW OF SMALL CRAFT ADVISORY CONDITIONS. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED ON THE EAST END OF THE LAKE FOR THURSDAY BUT MAY NEED TO BE EXPANDED TO THE WEST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR LEZ144>149. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ142- 143. && $$ SYNOPSIS...ABE NEAR TERM...ABE SHORT TERM...ABE/DJB LONG TERM...MULLEN AVIATION...TK MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
621 PM EST MON FEB 27 2012 .SYNOPSIS... HIGH PRESSURE TO THE WEST WILL QUICKLY BUILD EAST OVER THE AREA TONIGHT. THE HIGH WILL MOVE TO THE EAST COAST BY LATE TUESDAY. ANOTHER STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE CENTRAL GREAT LAKES WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... BIG ISSUE IN THE SHORT TERM WILL BE THE WINDS THIS EVENING IN RESPONSE TO A RATHER TIGHT GRADIENT BETWEEN LOW PRESSURE OVER THE NORTHERN GREAT LAKES AND STRONG HIGH PRESSURE OVER THE PLAINS QUICKLY BUILDING TOWARD THE AREA. HAVE EXPANDED THE WIND ADVISORY ACROSS EASTERN COUNTIES WITH EXCEPTION FOR THE FAR SOUTH THROUGH THIS EVENING. HRRR MODEL RUNS HAVE BEEN HANDLING THE WINDS RATHER WELL THIS AFTERNOON...AND THEY HAVE ADVISORY WIND GUSTS PUSHING THROUGH NORTHEAST OHIO COUNTIES OVER THE NEXT SEVERAL HOURS. WINDS SHOULD DIMINISH QUICKLY FROM WEST TO EAST ESPECIALLY AFTER SUNSET TONIGHT. AFTER MIDNIGHT EXPECTING WINDS TO BE DOWN BELOW 10 MPH. ASIDE FROM THAT A DRY AND MOSTLY CLEAR NIGHT EXPECTED WITH TEMPS DROPPING BACK TO THE LOWER TO MID 20S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... HIGH PRESSURE OVER THE AREA TUESDAY MORNING...THEN MOVING TO THE EAST WILL ALLOW FOR A QUIET AND DRY WEATHER DAY WITH SEASONABLE TEMPERATURES. LATEST MODELS SEEM TO BE DELAYING THE ONSET OF THE PRECIP ACROSS THE AREA TUESDAY NIGHT. WHILE CLOUDS ARE EXPECTED TO OVERSPREAD THE REGION EARLY ON...THINKING PERHAPS NOT TOWARD 06Z ACROSS THE SOUTHWEST AREAS AND NOT UNTIL CLOSE TO 12Z WED FOR PRECIP ACROSS NW PA. DO BRING UP POPS QUICKLY ACROSS THE AREA THOUGH AFTER 06Z. STILL SOME QUESTION AS TO PRECIP TYPE AT THE ONSET ESPECIALLY FROM CLE-CAK NORTHEAST. ACROSS OH THINKING THAT THERE MAY BE A RAIN/SNOW MIX WITH BEST CONFIDENCE OF ALL SNOW AT THE ONSET FOR FAR NE OH AND NW PA. MODELS SHOWING LOWER LEVELS WARMING UP ENOUGH BY 12Z WED THOUGH THAT MANY LOCATIONS WILL SWITCH OVER TO RAIN. MODELS LEANING TOWARD A MORE NORTHERN TRACK OF THE LOW CENTER ALLOWING MUCH OF THE AREA TO GET WARM ON WED. LEFT THE HIGH POPS AND MENTION OF THUNDER IN THE MORNING...BUT THEN CONCERNED ABOUT DRY SLOT MOVING ESPECIALLY INTO WESTERN AREAS FOR THE AFTERNOON SO REDUCED POPS AND CLOUDS A BIT ACROSS THE WEST. TEMPS WILL ALSO BE TRICKIEST DURING WED SO FOR NOW USED A BLEND OF MAV AND MET NUMBERS. CONCERNED MOST ABOUT NORTHERN AREAS WHICH MAY GET WARMER THAN FORECAST. ALSO CONCERNED ABOUT WIND POTENTIAL ON WED ESPECIALLY ACROSS THE WEST WHERE BETTER MIXING IS POSSIBLE. LOW PRESSURE NORTH OF THE AREA WEDNESDAY NIGHT AND THROUGH MUCH OF THURSDAY WILL ALLOW FOR SOME RAIN/SNOW SHOWERS MAINLY ACROSS THE NORTH WEDNESDAY NIGHT...THEN CONTINUED CHANCES FOR SHOWERS ACROSS NE OH AND NW PA THROUGH MUCH OF THURSDAY. HIGH PRESSURE RIDGING IN WILL DRY OUT THE AREA THURSDAY NIGHT. && .LONG TERM /FRIDAY THROUGH MONDAY/... SOUTHERLY WINDS WILL BE ON THE INCREASE ON FRIDAY AS LOW PRESSURE MOVES FROM THE CENTRAL PLAINS TO THE CENTRAL GREAT LAKES BY FRIDAY EVENING. THIS WILL PROVIDE WARM CONDITIONS FOR THE REGION WITH HIGHS INTO THE 50S FOR MOST LOCATIONS. RAIN CHANCES WILL BE ON THE INCREASE FRIDAY EVENING INTO THE OVERNIGHT. SOME RAIN MAY LINGER INTO SATURDAY MORNING. COOLER AIR WILL SPILL ACROSS THE LAKE SATURDAY NIGHT INTO EARLY SUNDAY AND COULD BE JUST COLD ENOUGH TO PROVIDE A FEW SNOW SHOWERS OFF OF LAKE ERIE. ANOTHER FAST MOVING STORM SYSTEM MAY AFFECT THE REGION SUNDAY NIGHT AND MAY ENHANCE ANY SNOW SHOWERS THAT ARE IN THE AREA. SLIGHTLY COOLER ON SATURDAY WITH HIGHS BACK INTO THE 40S. EVEN COOLER BY SUNDAY INTO MONDAY WITH HIGHS AT MOST LOCATIONS WITHIN A COUPLE DEGREES OF 40. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... HIGH PRESSURE WILL CONTINUE TO BUILD IN ACROSS THE AREA OVERNIGHT BEHIND A COLD FRONT NOW EAST OF THE AREA. MOISTURE BETWEEN 2 AND 3 KFT OVER SRN LWR MI ON THE BACK SIDE OF THE ASSOCIATED SURFACE LOW MOVING ESE TOWARD THE AREA BUT IR SATELLITE LOOP SHOWS THE CLOUDS DISSIPATING AS THEY APPROACH. THE CLOUDS DID MANAGE TO GET INTO KTOL AND STILL BELIEVE THEY WILL GET INTO KCLE AND KERI THROUGH THE EVENING HOURS HOWEVER FOR NOW WILL NOT EXPECT ANY RESTRICTION. WINDS REMAIN GUSTY AT 23Z HOWEVER THEY HAVE BEEN DIMINISHING OVER THE PAST HOUR. THROUGH THE EVENING EXPECT WINDS TO DIMINISH RAPIDLY AS LOW LEVELS DECOUPLE. TUESDAY EXPECT SO HIGH LEVEL MOISTURE MOVING IN BUT EXPECT CIGS TO REMAIN VFR ABOVE BKN- OVC120-150. OUTLOOK...PERIODS OF NON-VFR WILL RETURN TUESDAY NIGHT AND CONTINUE AT TIMES THROUGH THURSDAY. NON-VFR MAY RETURN BY FRIDAY NIGHT INTO SATURDAY. && .MARINE... A COLD FRONT MOVING ACROSS LAKE ERIE THIS AFTERNOON IS RESPONSIBLE FOR STRONG WESTERLY WINDS OF 20 TO 30 KNOTS. WINDS ARE APPROACHING GALE FORCE ON THE EAST END OF THE LAKE BUT SHOULD REMAIN JUST BELOW GIVEN THAT THE COLD ADVECTION BEHIND THE FRONT IS NOT THAT STRONG. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL NEARSHORE WATERS AND WILL COME TO AN END FROM WEST TO EAST OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD AND WINDS/WAVES QUICKLY DECREASE. EASTERLY WINDS WILL INCREASE ON TUESDAY NIGHT AHEAD OF THE NEXT LOW PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. WE WILL HAVE TO MONITOR THE EXACT TRACK AND STRENGTH OF THE SURFACE LOW FROM WEDNESDAY INTO THURSDAY TO DETERMINE MOST LIKELY WINDOW OF SMALL CRAFT ADVISORY CONDITIONS. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED ON THE EAST END OF THE LAKE FOR THURSDAY BUT MAY NEED TO BE EXPANDED TO THE WEST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR OHZ003-006>011- 017>020-027>030. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR LEZ144>149. SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ142- 143. && $$ SYNOPSIS...ABE NEAR TERM...ABE SHORT TERM...ABE LONG TERM...MULLEN AVIATION...TK MARINE...KEC
AREA FORECAST DISCUSSION
NWS NORMAN OK
906 PM CST MON FEB 27 2012 .DISCUSSION... DEW POINT TEMPERATURES WERE RAISED SLIGHT IN LINE WITH TRENDS AND THE RUC FORECAST OVERNIGHT. OTHERWISE LITTLE CHANGES ARE NECESSARY. MOISTURE WILL INCREASE SLOWLY ACROSS THE SOUTHWEST HALF OF OKLAHOMA TO THE SOUTH OF A WEAK STATIONARY FRONT. LIGHT RAIN THAT IS OCCURRING IN THE EASTERN TEXAS PANHANDLE WILL LIKELY ALSO DEVELOP FARTHER EAST WITH INCREASING LOW LEVEL WINDS OVER THE FRONT. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 60 51 65 39 / 10 40 70 20 HOBART OK 57 51 71 38 / 30 60 60 10 WICHITA FALLS TX 61 55 76 42 / 30 60 50 20 GAGE OK 52 45 69 33 / 20 60 60 10 PONCA CITY OK 58 50 65 37 / 10 40 70 30 DURANT OK 63 52 68 51 / 10 30 40 40 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR OKZ004-005-009-010-014>016-021-022-033>037. WIND ADVISORY FROM 10 AM TO 7 PM CST TUESDAY FOR OKZ004>006- 009>011-014>016-021-022-033>036. TX...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR TXZ083>085-087-088. WIND ADVISORY FROM 10 AM TO 7 PM CST TUESDAY FOR TXZ083-084-087. && $$ 09/24
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
520 AM EST SUN FEB 26 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE INTO PENNSYLVANIA TODAY AND DRIFT EAST TO THE MID-ATLANTIC COAST TONIGHT. NORTHWEST FLOW ALOFT WILL GIVE WAY TO A MILD ZONAL FLOW PATTERN THAT WILL CONTINUE THROUGH NEXT WEEK. IN THIS PROGRESSIVE PATTERN...A SERIES OF STORM SYSTEMS OF PACIFIC ORIGIN WILL PASS NORTH OF PENNSYLVANIA WITH THE BEST CHANCE OF WIDESPREAD PRECIPITATION COMING ON WEDNESDAY. && .NEAR TERM /UNTIL NOON TODAY/... WANING CHANNELED LAKE MOISTURE...TOPPED BY WEAK WESTERLY ISENTROPIC UPGLIDE WITHIN THE 275-285K LAYER...IS CAPTURED VERY WELL BY THE 06Z RUC AND WILL BE FOLLOWED CLOSELY FOR THE EXTENT/MOVEMENT OF CLOUD COVER /PRODUCING GENERALLY LIGHT SNOW SHOWERS/FLURRIES/ OVER THE NEXT SEVERAL HOURS ACROSS THE CENTRAL AND WESTERN MTNS. THIS AREA OF SHALLOW...BUT RATHER COLD STRATO CU WITH CLOUD TEMPS OF IN THE -9-14C RANGE WILL SLOWLY ERODE FROM BOTH THE SOUTHWEST AND EAST DURING THE MID TO LATE MORNING HOURS...BUT CONTINUE TO PRODUCE FLURRIES AND SCATTERED NARROW BANDS OF LIGHT SNOW SHOWERS THROUGH DAYBREAK. ANY SNOW ACCUMS WILL BE LIMITED TO JUST A TENTH OF AN INCH OR SO /DUSTING/ ACROSS THE ALLEGHENY PLATEAU. WINDS ARE SUBSIDING QUICKLY OVER WESTERN PA AS HIGH PRES BUILDS INTO THE UPPER OH VLY. HOWEVER 15-25KT WILL CONTINUE INTO THE EARLY MORNING HOURS IN THE EAST BEFORE RELAXING AS THE DAY WEARS ON. MID-DAY TEMPERATURES SHOULD RANGE FROM THE MID 20S IN THE NW TO UPPER 30S IN THE SE. && .SHORT TERM /NOON TODAY THROUGH 6 AM MONDAY/... AS THE SFC HIGH SHIFTS EWD TO THE MID-ATLC COAST THIS AFTN AND INTO TNT...WAA WILL STEADILY INC IN THE RETURN FLOW AHEAD OF LOW PRES MOVG THRU THE GREAT LKS. UNDER PARTLY TO MOSTLY SUNNY SKIES HIGH TEMPS WILL GENERALLY REACH CLIMO VALUES WITH THE EXCEPTION OF THE WESTERN HIGH TERRAIN...WHERE YESTERDAYS SNOW COVER SHOULD HOLD MAXES ABOUT 5 DEGREES BELOW NORMAL ON AVG. MODELS ARE IN GOOD AGREEMENT WITH LOW PRESSURE REACHING THE U.P. OF MI BY THE END OF THE PD. TEMPS SHOULD LEVEL OFF EARLY IN THE WEST AND MAY RISE A FEW DEGS TOWARD 12Z AS W/SWLY FLOW PICKS UP AHEAD OF TRAILING COLD FRONT PUSHING INTO THE UPPER OH VLY. TEMPS SHOULD EXHIBIT TYPICAL DIURNAL TREND OVR THE ERN VLYS AS BLYR DECOUPLES UNDER DEPARTING SFC HIGH. && .LONG TERM /MONDAY THROUGH SATURDAY/... MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE MID ATLANTIC COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH. WE`LL CONTINUE TO ADVERTISE LITTLE /OR MORE LIKELY/...NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN FOR THE PERIOD 12Z MONDAY THROUGH 00Z WEDNESDAY. POPS ACRS THE NRN AND WESTERN MTNS WILL BE LIMITED TO 10-15 PERCENT AT BEST. A SEVERAL HOUR PERIOD OF BKN STRATO/LOW-BASED AC CLOUDS WILL PROGRESS SE ACROSS THE STATE...ALONG AND IN ADVANCE OF A COLD FRONT IN THE AFTERNOON AND EVENING. BUFKIT NAM TIME/HEIGHT CROSS SECTION SUGGEST THAT THE BOUNDARY LAYER WILL GROW TO BETWEEN 4-6 KFT AGL MONDAY. WINDS AT THE TOP OF THIS MIXED LAYER WILL BE FROM THE WSW AT 35-45KT...AND SOME GUSTS OF AT LEAST 30-35 KTS WILL BE MIXED TO THE SFC BEGINNING DURING THE MIDDAY AND CONTINUING THROUGH THE AFTERNOON HOURS. THE GUSTY WIND...UNSEASONABLY MILD TEMPERATURES...LOW RELATIVE HUMIDITY AND DRY FINE FUELS ACROSS SOUTHERN PARTS OF THE CWA WILL LEAD TO THE POTENTIAL FOR ELEVATED FIRE WEATHER CONDITIONS. TEMPS MONDAY WILL BE THE MILDEST READINGS THAT WE/LL SEE IN AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S AND UPPER 40S ACROSS THE NORTHERN MTNS...TO THE MID AND UPPER 50S THROUGHOUT THE MIDDLE AND LOWER SUSQUEHANNA RIVER VALLEY. A SIGNIFICANT STORM WILL HEAD OUT OF THE CENTRAL ROCKIES TUESDAY...AND GRIND NORTHEAST TO THE UPPER MIDWEST BY WEDNESDAY. THIS SYSTEM WILL SPREAD THICKENING CLOUDS INTO THE REGION LATE TUESDAY/TUESDAY NIGHT WITH PRECIPITATION BEGINNING SOMETIME DURING THE MID TO LATE MORNING HOURS. VERY INTERESTING DUAL JET STRUCTURE WILL DEVELOP ACROSS THE NE US DURING THE MIDWEEK PERIOD WITH THE TAIL END OF A NRN SPEED MAX MOVING ACROSS THE NEW ENGLAND STATES...WHILE THE NOSE OF SOUTHERN STREAM JET HEADS EAST OUT OF THE OHIO VALLEY BY 18Z WEDNESDAY. NEAR SFC...AGEOSTROPHIC NORTHERLY FLOW WILL STRENGTHEN TO AN IMPRESSIVE 40-45 KTS DURING THE DAY WEDNESDAY WHICH WILL HELP TO DRIVE SOUTH/LOCK IN SHALLOW COLD AIR ACROSS THE CENTRAL AND ERN PARTS OF THE FCST AREA. U.S./EURO OPERATIONAL MODEL CONSENSUS IS FOR AT LEAST A 3- 6 HOUR PERIOD OF MIXED PRECIP /AND MAYBE EVEN A FEW TO SVRL INCHES OF SNOW ACROSS THE NCENT MTNS...EAST TOWARD THE WYOMING VALLEY AND POCONOS/. OF THE U.S. ENSEMBLE PACKAGES...THE 03Z SREF HAS MOST MEMBERS DISPLAYING SNOW OR FZRA FOR THE REGION BETWEEN KIPT AND KELM...WHILE THE GEFS IS PREDOMINANTLY RAIN. EVEN AFTER A LIKELY CHANGEOVER TO LIQUID PRECIP IN THE LATE WEDNESDAY AFTERNOON AS TEMPS ALOFT RISE TO PLUS 3-6C....SFC WET BULB TEMPS AT...OR JUST BELOW FREEZING COULD CAUSE PERIODS OF FREEZING RAIN TO CONTINUE INTO WEDNESDAY NIGHT AND EARLY THURSDAY - ESP TO THE NORTH AND EAST OF KIPT. SNOW/SLEET AMOUNTS AND THE THREAT FOR FREEZING RAIN SHOULD BE ENOUGH TO POST WINTER WEATHER ADVISORIES FOR PORTIONS OF CENTRAL AND NRN PENN WEDNESDAY. MEDIAN RAINFALL/LEQ AMOUNTS OFF THE GEFS STILL APPEAR TO BE CLUSTERED BETWEEN 0.65 AND 0.90 INCH. AFTER A BRIEF PERIOD OF COOLER WEATHER WITH SCATTERED RAIN SHOWERS IN THE SE...AND NRN/WRN MTN SNOW SHOWERS...MILDER CONDITIONS RETURN TO CLOSE OUT THE WEEK. SATURDAY WILL BRING ANOTHER CHC FOR RAIN OR MIXED PRECIP IN THE SW FLOW ALOFT AHEAD OF AN UPPER TROUGH AMPLIFYING OVER THE CENTRAL U.S. AND MISSISSIPPI VALLEY FRIDAY AND FRI NIGHT. && .AVIATION /10Z SUNDAY THROUGH THURSDAY/... WANING NWLY FLOW ALOFT OVER THE GREAT LAKES IS STILL PRODUCING LIGHT SNOW SHOWERS AND FLURRIES OVR WESTERN AND CENTRAL TAFS. VSBYS ARE BETTER THAN PREVIOUSLY FCST /3-8SM/ AT JST AND THEREFORE AMENDED TO REFLECT THIS. IR SATL TRENDS SHOW THE BACK EDGE OF THE LOW CLOUDS SHOULD BE NEAR JST AROUND 12Z. EXPECT THE LIGHT SNOW SHOWERS/FLURRIES AND LOW CLOUDS TO SLOWLY DIMINISH THROUGH THE MORNING...AS HIGH PRES BUILDS INTO THE REGION FROM THE WEST. THIS WILL ALSO LEAD TO SUBSIDING WINDS. VFR CONDS WILL PREVAIL FM THIS AFTN THROUGH THE REMAINDER OF THE 06Z TAF PD. OUTLOOK... MON...VFR. OCNL MVFR -SHRA PSBL NRN TERMINALS WITH WK CLD FROPA. TUE...VFR. RESTRICTIONS PSBL LATE TUE NGT. WED/THU...RESTRICTIONS LKLY. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT/STEINBUGL NEAR TERM...LAMBERT/STEINBUGL SHORT TERM...STEINBUGL LONG TERM...LAMBERT AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
331 AM EST SUN FEB 26 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE INTO PENNSYLVANIA TODAY AND DRIFT EAST TO THE MID-ATLANTIC COAST TONIGHT. NORTHWEST FLOW ALOFT WILL GIVE WAY TO A MILD ZONAL FLOW PATTERN THAT WILL CONTINUE THROUGH NEXT WEEK. IN THIS PROGRESSIVE PATTERN...A SERIES OF STORM SYSTEMS OF PACIFIC ORIGIN WILL PASS NORTH OF PENNSYLVANIA WITH THE BEST CHANCE OF WIDESPREAD PRECIPITATION COMING ON WEDNESDAY. && .NEAR TERM /UNTIL NOON TODAY/... WANING CHANNELED LAKE MOISTURE...TOPPED BY WEAK WESTERLY ISENTROPIC UPGLIDE WITHIN THE 275-285K LAYER...IS CAPTURED VERY WELL BY THE 06Z RUC AND WILL BE FOLLOWED CLOSELY FOR THE EXTENT/MOVEMENT OF CLOUD COVER /PRODUCING GENERALLY LIGHT SNOW SHOWERS/FLURRIES/ OVER THE NEXT SEVERAL HOURS ACROSS THE CENTRAL AND WESTERN MTNS. THIS AREA OF SHALLOW...BUT RATHER COLD STRATO CU WITH CLOUD TEMPS OF IN THE -9-14C RANGE WILL SLOWLY ERODE FROM BOTH THE SOUTHWEST AND EAST DURING THE MID TO LATE MORNING HOURS...BUT CONTINUE TO PRODUCE FLURRIES AND SCATTERED NARROW BANDS OF LIGHT SNOW SHOWERS THROUGH DAYBREAK. ANY SNOW ACCUMS WILL BE LIMITED TO JUST A TENTH OF AN INCH OR SO /DUSTING/ ACROSS THE ALLEGHENY PLATEAU. WINDS ARE SUBSIDING QUICKLY OVER WESTERN PA AS HIGH PRES BUILDS INTO THE UPPER OH VLY. HOWEVER 15-25KT WILL CONTINUE INTO THE EARLY MORNING HOURS IN THE EAST BEFORE RELAXING AS THE DAY WEARS ON. MID-DAY TEMPERATURES SHOULD RANGE FROM THE MID 20S IN THE NW TO UPPER 30S IN THE SE. && .SHORT TERM /NOON TODAY THROUGH 6 AM MONDAY/... AS THE SFC HIGH SHIFTS EWD TO THE MID-ATLC COAST THIS AFTN AND INTO TNT...WAA WILL STEADILY INC IN THE RETURN FLOW AHEAD OF LOW PRES MOVG THRU THE GREAT LKS. UNDER PARTLY TO MOSTLY SUNNY SKIES HIGH TEMPS WILL GENERALLY REACH CLIMO VALUES WITH THE EXCEPTION OF THE WESTERN HIGH TERRAIN...WHERE YESTERDAYS SNOW COVER SHOULD HOLD MAXES ABOUT 5 DEGREES BELOW NORMAL ON AVG. MODELS ARE IN GOOD AGREEMENT WITH LOW PRESSURE REACHING THE U.P. OF MI BY THE END OF THE PD. TEMPS SHOULD LEVEL OFF EARLY IN THE WEST AND MAY RISE A FEW DEGS TOWARD 12Z AS W/SWLY FLOW PICKS UP AHEAD OF TRAILING COLD FRONT PUSHING INTO THE UPPER OH VLY. TEMPS SHOULD EXHIBIT TYPICAL DIURNAL TREND OVR THE ERN VLYS AS BLYR DECOUPLES UNDER DEPARTING SFC HIGH. && .LONG TERM /MONDAY THROUGH SATURDAY/... MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH. VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES. THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN PLAINS AND ACROSS THE UPPER GLAKES REGION. THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE NORTH OF LAKE ONTARIO. TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER SUSQ VALLEY. ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE GFS OR GEFS SOLUTIONS. EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV AND KIPT. MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH. NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE REGION. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... WANING NWLY FLOW ALOFT OVER THE GREAT LAKES IS STILL PRODUCING LIGHT SNOW SHOWERS AND FLURRIES OVR WESTERN AND CENTRAL TAFS. VSBYS ARE BETTER THAN PREVIOUSLY FCST /3-8SM/ AT JST AND THEREFORE AMENDED TO REFLECT THIS. IR SATL TRENDS SHOW THE BACK EDGE OF THE LOW CLOUDS SHOULD BE NEAR JST AROUND 12Z. EXPECT THE LIGHT SNOW SHOWERS/FLURRIES AND LOW CLOUDS TO SLOWLY DIMINISH THROUGH THE MORNING...AS HIGH PRES BUILDS INTO THE REGION FROM THE WEST. THIS WILL ALSO LEAD TO SUBSIDING WINDS. VFR CONDS WILL PREVAIL FM THIS AFTN THROUGH THE REMAINDER OF THE 06Z TAF PD. OUTLOOK... MON...VFR. OCNL MVFR -SHRA PSBL NRN TERMINALS WITH WK CLD FROPA. TUE...VFR. RESTRICTIONS PSBL LATE TUE NGT. WED/THU...RESTRICTIONS LKLY. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT/STEINBUGL NEAR TERM...LAMBERT/STEINBUGL SHORT TERM...STEINBUGL LONG TERM...LAMBERT/GARTNER AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
233 AM EST SUN FEB 26 2012 .SYNOPSIS... HIGH PRESSURE WILL MOVE INTO PENNSYLVANIA TODAY AND DRIFT EAST TO THE MID-ATLANTIC COAST TONIGHT. NORTHWEST FLOW ALOFT WILL GIVE WAY TO A MILD ZONAL FLOW PATTERN THAT WILL CONTINUE THROUGH NEXT WEEK. IN THIS PROGRESSIVE PATTERN...A SERIES OF STORM SYSTEMS OF PACIFIC ORIGIN WILL PASS NORTH OF PENNSYLVANIA WITH THE BEST CHANCE OF WIDESPREAD PRECIPITATION COMING ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... WANING CHANNELED LAKE MOISTURE...TOPPED BY WEAK WESTERLY ISENTROPIC UPGLIDE WITHIN THE 275-285K LAYER...IS CAPTURED VERY WELL BY THE 06Z RUC AND WILL BE FOLLOWED CLOSELY FOR THE EXTENT/MOVEMENT OF CLOUD COVER /PRODUCING GENERALLY LIGHT SNOW SHOWERS/FLURRIES/ OVER THE NEXT SEVERAL HOURS ACROSS THE CENTRAL AND WESTERN MTNS. THIS AREA OF SHALLOW...BUT RATHER COLD STRATO CU WITH CLOUD TEMPS OF IN THE -9-14C RANGE WILL SLOWLY ERODE FROM BOTH THE WEST AND EAST DURING THE MID TO LATE MORNING HOURS...BUT CONTINUE TO PRODUCE FLURRIES AND SCATTERED NARROW BANDS OF LIGHT SNOW SHOWERS THROUGH DAYBREAK. ANY SNOW ACCUMS WILL BE LIMITED TO JUST A TENTH OF AN INCH OR SO ACROSS THE ALLEGHENY PLATEAU. TEMPS WILL FALL ANOTHER 2-4 DEGREES IN MOST LOCATIONS OVER THE NEXT 4-5 HOURS AND WINDS WILL CONTINUE IN THE 10-15 KT RANGE FROM THE WEST NORTHWEST WITH SOME GUSTS AROUND 20 MPH. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/... RIDGE OF HIGH PRESSURE OVR PA WILL PROVIDE SUNNY SKIES AND LIGHT WINDS FOR MOST OF THE STATE. ANY LINGERING STRATO-CU OVR THE LAUREL HIGHLANDS EARLY IN THE DAY WILL MIX OUT BY LATE AM. A BIT OF AFTN CLOUDINESS IS POSSIBLE ACROSS THE NW MTNS...WHERE WAA DEVELOPS AHEAD OF LOW PRES OVR THE W GRT LKS. GEFS 925 TEMPS SUPPORT HIGH TEMPS FROM THE M30S W MTNS...TO THE M40S ACROSS THE LOWER SUSQ VALLEY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... MILDER TEMPS RETURN FOR MONDAY AND TUESDAY AS THE FLOW ALOFT BECOMES HIGHLY ZONAL...AND A SFC HIGH PRESSURE RIDGE SLIDES OFF THE EAST COAST CREATING A SOUTHERLY FLOW OF AIR INTO THE COMMONWEALTH. VIRTUALLY NO CHC OF PRECIP ANYWHERE ACROSS CENTRAL AND SOUTHERN PENN FOR THE PERIOD 12Z SUNDAY THROUGH 00Z WEDNESDAY. EVEN POPS ACRS THE NRN MTNS WILL ONLY CLIMB SLIGHTLY TO AROUND 10 PERCENT AT TIMES. THERE WILL BE A FEW...SEVERAL-HOUR PERIODS OF MID CLOUDS /AND PERHAPS EVEN SOME HIGH BASED STRATO CU/ SLIDING EAST ACROSS THE REGION SUNDAY AND MONDAY AS LOW PRESSURE MOVES EAST FROM THE NRN PLAINS AND ACROSS THE UPPER GLAKES REGION. THE SOUTHWEST TO WESTERLY FLOW MONDAY COULD BECOME QUITE GUSTY...AND OVER 30 MPH AT TIMES AS THE AFOREMENTIONED LOW DRIFTS BY TO THE NORTH OF LAKE ONTARIO. TEMPS MONDAY SHOULD BE THE MILDEST READINGS THAT WE/LL SEE IN AT LEAST A WEEK OR SO. HIGHS WILL VARY FROM THE MID 40S ACROSS THE NORTHERN MTNS...TO THE LOWER AND MID 50S IN THE CENTRAL AND LOWER SUSQ VALLEY. ANOTHER MORE SIGNIFICANT SYSTEM LIKELY IMPACTS THE REGION FOR WEDNESDAY INTO THURSDAY. SFC LOW TRACKS WELL TO OUR NW...THRU THE UPPER MIDWEST/UPPER GLAKES REGION DURING THIS PERIOD A RATHER STRONG...1035MB SFC HIGH WILL ATTEMPT TO FUNNEL LLVL COLD AIR SOUTH INTO THE REGION FOR THE TUESDAY NIGHT - THURSDAY PERIOD. THE 00Z EC MODEL APPEARS TO PAINT THIS LLVL COLD AIR DAMMING MORE SO THAN THE GFS OR GEFS SOLUTIONS. EC SHOWS A LONGER DURATION/FEW DAY EVENT WEDNESDAY THROUGH THURSDAY ASSOCIATED WITH SECONDARY SFC LOW DEVELOPMENT NEAR THE DELMARVA COAST /ALONG IT EASTWARD EXTENDING LLVL QUASI STNRY FRONT/. IN CONTRAST...THE GEFS AND GFS ARE MORE PROGRESSIVE WITH THIS SYSTEM AND CARRY A MORE CONSOLIDATED/SINGLE SFC LOW ENE ACROSS THE UPPER GREAT LAKES...WHILE LIFTING A SFC-850 MB WARM FRONT GRADUALLY NORTH ACROSS THE STATE ON WEDNESDAY. GEFS PLUMES AND GFS THERMAL AND WET BULB PROFILES PAINT MAINLY RAIN FOR THE REGION...WHILE THE EC SUGGESTS AN EXTENDING PERIOD OF MIXED PRECIP AND EVEN SOME ACCUMULATING WET SNOW LIKELY ACROSS MAINLY THE NORTH CENTRAL AND EASTERN MTNS OF THE STATE WEDNESDAY INTO THURSDAY. PAINTED A FEW INCHES OF ACCUMULATION IN OUR GRIDS ACROSS THE REGION NORTH OF KUNV AND KIPT. MEDIAN RAINFALL/LEQ AMOUNTS ARE BETWEEN 0.75 AND 1.00 INCH. NEXT WEEK CLOSES OUT MAINLY DRY...WITH ABOVE NORMAL TEMPS AND PARTLY CLOUDY SKIES AS HIGH PRESSURE AT THE SFC AND ALOFT MOVES ACROSS THE REGION. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... WANING NWLY FLOW ALOFT OVER THE GREAT LAKES IS STILL PRODUCING SNOW SHOWERS AND IFR VIS AT JST. MVFR CIGS AND VFR VISBYS ARE COMMON ELSEWHERE AT KBFD/KAOO/KUNV...WITH VFR PREVAILING IN THE EAST. EXPECT THE SNOW SHOWERS TO SLOWLY DIMINISH THROUGH THE MORNING AS HIGH PRES BUILDS INTO THE REGION. THIS WILL ALSO LEAD TO SUBSIDING WINDS ESPECIALLY AT WESTERN SITES. LOW CLOUDS WILL GIVE WAY TO M/CLR SKIES BY THIS AFTN WITH WIDESPREAD VFR CONDS THROUGH THE REMAINDER OF THE 06Z TAF PD. OUTLOOK... MON...VFR. OCNL MVFR -SHRA PSBL NRN TERMINALS WITH WK CLD FROPA. TUE...VFR. RESTRICTIONS PSBL LATE TUE NGT. WED/THU...RESTRICTIONS LKLY. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/STEINBUGL NEAR TERM...LAMBERT/STEINBUGL SHORT TERM...FITZGERALD/LA CORTE LONG TERM...LAMBERT/GARTNER AVIATION...STEINBUGL
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1105 AM CST SUN FEB 26 2012 .UPDATE... SURFACE LOW PRESSURE OVER SOUTHWEST MINNESOTA WILL TRACK NORTHEAST INTO NORTHERN WI BY EARLY EVENING AND ACROSS THE UPPER PENINSULA OF MICHIGAN TONIGHT. STRONG SOUTHEAST WINDS SHOULD BE APPROACHING THEIR HIGHEST SPEEDS AND GUSTS BETWEEN NOW AND AROUND 1 PM...PER RUC AND 12Z NAM MODEL SNDGS. WE ARE JUST BEGINNING TO MIX INTO THE STRONG WINDS THAT ARE MOVING OVERHEAD THIS MORNING WITH THE LOW LEVEL JET. THE EXACT HEIGHT OF MIXING IS VERY UNCERTAIN GIVEN THE MID CLOUDS OVERHEAD AND SNOW PACK/COLD SURFACE TEMPERATURES. MODELS SUGGEST MIXING UP TO AROUND 1500 FEET AT MOST LOCATIONS...EXCEPT UP TO 2000 FEET AT SHEBOYGAN AND NORTHWARD. THEREFORE...OPTED TO ADD SHEBOYGAN COUNTY TO THE EXISTING WIND ADVISORY. MAX TEMPS ARE ALSO UNCERTAIN FOR THIS AFTERNOON. THE WARM AIR ADVECTION IS STRONG AND UPSTREAM OBS IN EASTERN IOWA ARE ALREADY IN THE UPPER 30S TO AROUND 40 ON THE NORTH END OF THE SNOWPACK. KEPT CONSERVATIVE MAX TEMPS AROUND 40 TO 41 GIVEN OUR SNOWPACK AND MID CLOUDS OVERHEAD LIMITING THE HEATING AND MIXING...BUT WILL KEEP AN EYE ON THEM AND MAY NEED TO BUMP THEM UP A COUPLE OF DEGREES FOR THIS AFTERNOON. && .AVIATION/18Z TAFS/... STRONG LOW PRESSURE OVER SOUTHWEST MN WILL REACH NORTHERN WI LATE THIS AFTERNOON AND CROSS THE UPPER PENINSULA OF MICHIGAN TONIGHT. THE STRONG PRESSURE GRADIENT WITH THE LOW CROSSING TO THE NORTH WILL CAUSE STRONG AND GUSTY SOUTHERLY WINDS THROUGH THE AFTERNOON. WINDS WILL DIMINISH SLIGHTLY AS THEY VEER SOUTHWEST LATE THIS AFTERNOON. SURFACE WINDS WILL REMAIN ELEVATED AND GUSTY THROUGH TONIGHT OUT OF THE WEST DUE THE COLD AIR ADVECTION. SOUTHEAST WINDS ARE NOW TAPPING INTO THE STRONG WINDS JUST ABOVE THE SURFACE CAUSING HIGH WIND GUSTS. HIGHEST WIND GUSTS WILL BE NEAR LAKE MICHIGAN...INCLUDING MKE AND ENW. A WIND ADVISORY IS IN EFFECT FOR SOUTHEAST WI. WINDS 20 TO 25 KNOTS LIKELY WITH GUSTS UP TO 35 TO 40 KNOTS POSSIBLE THROUGH MID AFTERNOON. WITH 55 KNOT WINDS AROUND 2000 FT THIS MORNING...LOW LEVEL WIND SHEAR IS POSSIBLE. THE GREATEST DIRECTIONAL SHEAR IS BETWEEN THE SURFACE WITH SOUTHEAST WINDS AROUND 20 KNOTS...AND 3000 FEET WITH SOUTHWEST WINDS GREATER THAN 50 KNOTS. VFR CIGS TODAY...THEN MVFR AS COLD AIR STRATOCUMULUS PUSHES IN FROM THE NORTH BEHIND THE STRONG LOW INTO AT LEAST NORTHERN PORTIONS OF THE FORECAST AREA TOWARD THE DELLS TO SHEBOYGAN LATE TONIGHT. THE MVFR CIGS COULD SAG TOWARD THE ILLINOIS BORDER TOWARDS SUNRISE MONDAY. && .MARINE... STRONG LOW PRESSURE OVER SOUTHWEST MN WILL REACH NORTHERN WI LATE THIS AFTERNOON AND CROSS THE UPPER PENINSULA OF MICHIGAN TONIGHT. THE STRONG PRESSURE GRADIENT WITH THE LOW CROSSING TO THE NORTH WILL CAUSE STRONG AND GUSTY SOUTHERLY WINDS THROUGH THE AFTERNOON. A GALE WARNING IS IN EFFECT THROUGH 00Z. THIS IS THE TIME PERIOD WITH THE HIGHEST GUST POTENTIAL WITH A SOUTH WIND AND SLIGHT ONSHORE COMPONENT. WINDS AND GUSTS WILL DIMINISH SLIGHTLY AS WINDS VEER SOUTHWEST BEHIND THE SURFACE TROUGH/COLD FRONT LATE THIS AFTERNOON. WINDS AHEAD OF LOW WILL BUILD LARGE WAVES. SMALL CRAFT ADVISORIES WILL BE NEEDED AFTER THE GALES EXPIRE DUE TO BRISK WEST WINDS. && .PREV DISCUSSION... /ISSUED 325 AM CST SUN FEB 26 2012/ TODAY AND TONIGHT...FORECAST CONFIDENCE HIGH. STRONG LOW PRESSURE OVER SOUTH DAKOTA WILL MOVE TO CENTRAL MINNESOTA BY NOON AND REACH SOUTHERN LAKE SUPERIOR THIS EVENING. THE STRONG PRESSURE GRADIENT WITH THE LOW CROSSING TO THE NORTH WILL CAUSE STRONG AND GUSTY WINDS TO DEVELOP THIS MORNING. THE SOUTHEASTERLY COMPONENT AHEAD OF THE SFC TROUGH/COLD FRONT WILL ALLOW FOR A LITTLE DEEPER MIXING NEAR THE SHORELINE...SO EXPECT HIGHEST WINDS THERE. ELSEWHERE...IT IS A LITTLE UNCERTAIN AS TO HOW FAR UP THE AIR WILL MIX. 00Z NAM AND GFS ARE SHOWING WINDS UP TO 60 KNOTS AT 850 MB BUT THE QUESTION IS HOW HIGH THE MIXED LAYER WILL GET TO. BY THE TIME LAPSE RATES INCREASE TO 5 C/KM FROM 900 MB IS THIS AFTERNOON AFTER THE CORE OF THE STRONGEST WINDS HAVE PUSHED OFF TO THE EAST. NAM FORECAST SOUNDINGS MIX 35 KNOT GUSTS AROUND NOON IN THE SOUTHEAST. RUC MIXES OUT HIGHER ALMOST TO 2 THSD FT AND MIXES GUSTS TO AROUND 40 KNOTS AT MKE. HOWEVER GIVEN SNOW COVER AND CURRENT INVERSION THIS MAY BE TO AGGRESSIVE. LAV GUST GUIDANCE KEEPS GUSTS TO 32 KNOTS. TEMPERATURES ARE ALSO TRICKY AS THE 850 MB WARM AIR ADVECTION COOLS BY AFTERNOON. THIS AND THE SNOW COVER SHOULD KEEP TEMPERATURES COOLER THAN THE MAV MOS GUIDANCE. NAM FORECAST SOUNDINGS INDICATE AT BEST MID 30S. THERE IS A SURGE OF WARMER AIR PUSHING INTO NORTHEAST MISSOURI WITH TEMPERATURES ALREADY IN THE MID 40S. GIVEN THE UNCERTAINTY OF THE LAPSE RATES IN THE LOWEST LAYERS IT MAY BE BEST TO GO WITH A WIND ADVISORY OVER PORTIONS OF SOUTHEAST WISCONSIN LEANING MORE TOWARD THE RUC. FAIRLY STRONG 700 MB UPWARD MOTION OF 9 UBAR/SEC WILL MOVE ACROSS THE FAR NORTHERN SECTIONS OF THE FORECAST AREA. HOWEVER MID LEVELS SATURATE ONLY IN THE 12 TO 18 THSD FT LAYER WITH MUCH OF THE LIFT IN THE DRIER LOW LEVELS. THEREFORE EXPECT MAINLY VIRGA WITH ONLY A FEW FLURRIES REACHING THE GROUND. EARLY TONIGHT A STRONG WEST WIND OCCURS AT 850 MB ON THE 06Z NAM...REACHING 70 KNOTS. THIS WITH STEEPER LAPSE RATES BEHIND COLD/OCCLUDED FRONT. WILL INCREASE WINDS FROM MOS FOR THIS. MONDAY - CONFIDENCE...MEDIUM COUPLE VORTS WITHIN SHORTWAVE TROUGH AXIS SHIFT EAST OF THE AREA BY EARLY AFTERNOON. HOWEVER AIRMASS QUITE DRY WITH PLENTY OF 700 DOWNWARD MOTION AND LOWER LEVEL COOL ADVECTION. 500 MILLIBAR FLOW BECOMES INCREASINGLY ANTICYCLONIC. SURFACE/850 GRADIENT SUGGESTS A NORTHWEST BREEZE WILL LIKELY PERSIST FOR MUCH OF THE MORNING BUT WITH SURFACE/850 RIDGE AXES COMING CLOSER DURING THE AFTERNOON...WINDS SHOULD EASE. TUESDAY - CONFIDENCE...MEDIUM SURFACE/850 RIDGE AXES WELL TO THE EAST. STRONG S/SE FLOW DEVELOPS IN THE LOW LEVELS. CYCLOGENESIS RAMPS UP IN RESPONSE TO HIGHLY DYNAMICAL UPPER SYSTEM APPROACHING IOWA. WARM ADVECTION INCREASES...WITH SOME DISAGREEMENT AMONGST THE MODELS ON HOW QUICK THE 850/925 LAYER WARMS. SURFACE TEMPS EXPECTED TO BE ABOVE FREEZING IF NAM SCENARIO PANS OUT WITH THE MORE PRONOUNCED WARM SURGE IN THE AFTERNOON. SOME SLEET POTENTIAL NOTED ON NAM SOUNDING AT KMSN. TUESDAY NIGHT - CONFIDENCE...MEDIUM VERY CONSISTENT SIGNALS FOR THE MAIN PRECIP EVENT THIS TIME FRAME WITH STRONG WAVE IMPINGING ON THE CWA. HIGH CONFIDENCE IN PRECIP OCCURRENCE AND LOW CONFIDENCE IN PRECIP TYPE. DIFFERENTIAL CYCLONIC VORTICITY ADVECTION ...NOSE OF 250 JET AIMED RIGHT INTO THE CWA AND CORRIDOR OF MOISTURE WITH SOUTHERLY FLOW ADVECTING HIGHER THETA-E AIR INTO SRN WI. MAIN CHALLENGE CONTINUES TO BE PRECIP TYPE. ECMWF SUGGESTS NORTHERN CWA REMAINS ALL SNOW WHILE OTHER MODELS MORE AGGRESSIVE WITH TIGHT 850 BAROCLINIC ZONE SHIFTING FURTHER NORTH OUT OF THE CWA. APPEARS THE SOUTHERN CWA WILL BE ALL RAIN WITH CONSENSUS AMONGST THE MODELS FOR A PURELY WARM PROFILE THERE...BUT THE NORTH REMAINS VULNERABLE TO THE WINTRY MIX OR ALL SNOW. PONDERED THUNDER IN PARTS OF THE SOUTH THOUGH LAPSE RATES/ELEVATED CAPE TOO MARGINAL FOR GRID INCLUSION AT THIS POINT. WEDNESDAY - CONFIDENCE...MEDIUM SURFACE/UPPER LOW PROGGD TO SHIFT ACROSS SRN WI. 700 LOW POSITION FAVORS THE NORTHERN CWA QPF MAX OF AROUND A TENTH OR A SMIDGE HIGHER. THERMAL PROFILE SUPPORTS A TRANSITION TO SOME LIGHT SNOW IN THE SOUTHERN AREAS AS WELL. THURSDAY - CONFIDENCE...MEDIUM APPEARS SHORTWAVE RIDGING WILL TAKE HOLD AND BRING A QUIET DAY IN THE WAKE OF THE PRIOR DAYS STORM SYSTEM. FRIDAY AND SATURDAY - CONFIDENCE...LOW TO MEDIUM ANOTHER UNSETTLED PERIOD AS UPPER FLOW BECOMES SOUTHWEST AND AN INITIAL WAVE RIDES NORTHEAST TOWARDS SE WI. MAIN VORT/UPPER TROUGH WILL THEN WAFFLE ACROSS WI ON SATURDAY KEEPING PRECIP CHANCES GOING. GFS A BIT MORE AGGRESSIVE ON THIS LOW RIDING NORTHEAST ALONG THE BAROCLINIC ZONE WHILE THE ECMWF IS A SKEWED A BIT MORE SOUTHEAST. AVIATION/12Z TAFS/...STRONG LOW PRESSURE OVER SOUTH DAKOTA WILL MOVE TO CENTRAL MINNESOTA BY NOON AND REACH SOUTHERN LAKE SUPERIOR THIS EVENING. THE STRONG PRESSURE GRADIENT WITH THE LOW CROSSING TO THE NORTH WILL CAUSE STRONG AND GUSTY WINDS TO DEVELOP THIS MORNING. SOUTH WINDS WILL INCREASE THIS MORNING WITH LOW LEVEL WIND SHEAR LIKELY. 55 KNOT WINDS DEVELOPING AROUND 2 THSD FT THIS MORNING. THE WINDS WILL BE STRONGEST FROM MID MORNING THROUGH EARLY AFTERNOON WITH THE SOUTHEAST TO SOUTH COMPONENT...THEN THEY WILL DIMINISH SLIGHTLY BEHIND THE SURFACE TROUGH AT 2 THSD FT AS THEY VEER TO THE SOUTHWEST. HOWEVER AT THE SURFACE WINDS WILL GUSTY INTO THE AFTERNOON AS LOW LEVEL LAPSE RATES INCREASE. SOME GUSTS TO 35 KNOTS POSSIBLE. EARLY TONIGHT A STRONG WEST WIND OCCURS AT 850 MB ON THE 06Z NAM...REACHING 70 KNOTS. THIS WITH STEEPER LAPSE RATES BEHIND COLD/OCCLUDED FRONT. WILL INCREASE WINDS FROM MOS FOR THIS AND MAY ALSO BRING SOME WIND SHEAR POTENTIAL. MAINLY VFR CIGS TODAY...THEN MVFR AS COLD AIR STRATOCUMULUS PUSHES IN FROM THE NORTH BEHIND THE STRONG LOW INTO AT LEAST NORTHERN PORTIONS TOWARD THE DELLS TO SHEBOYGAN LATE TONIGHT. THE MVFR CIGS COULD SAG TOWARD THE ILLINOIS BORDER TOWARDS SUNRISE MONDAY. MARINE...STRONG LOW PRESSURE OVER SOUTH DAKOTA WILL MOVE TO CENTRAL MINNESOTA BY NOON AND REACH SOUTHERN LAKE SUPERIOR THIS EVENING. THE STRONG PRESSURE GRADIENT WITH THE LOW CROSSING TO THE NORTH WILL CAUSE STRONG AND GUSTY WINDS TO DEVELOP THIS MORNING. A GALE WARNING IS IN EFFECT TODAY FROM 15Z TO 21Z. THIS IS THE TIME PERIOD WITH THE HIGHEST GUST POTENTIAL WITH A SOUTHEAST TO SOUTH WIND ONSHORE COMPONENT. WINDS AND GUSTS WILL DIMINISH SLIGHTLY AS WINDS VEER SOUTHWEST BEHIND THE SURFACE TROUGH/COLD FRONT. WINDS AHEAD OF LOW WILL BUILD LARGE WAVES. SMALL CRAFT ADVISORIES WILL BE NEEDED AFTER THE GALES EXPIRE DUE TO BRISK WEST WINDS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR WIZ052-060-065- 066-069>072. LM...GALE WARNING UNTIL 6 PM CST THIS EVENING FOR LMZ643>646. && $$ UPDATE...MRC TODAY/TONIGHT AND AVIATION/MARINE...HENTZ MONDAY THROUGH SATURDAY...COLLAR
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
1030 AM CST SUN FEB 26 2012 UPDATED SHORT TERM AND AVIATION PORTION. .SHORT TERM...TDA/TNGT/MON. IN THE NEAR-TERM...DRY LOW-LEVEL AIR TAKING A TOLL ON PRECIPITATION... AS MUCH WHAT IS ON RADAR IS VIRGA OR VERY LIGHT SPRINKLES AND FLURRIES. 26/15Z RUC SEEMS TO BE HANDLING THIS WELL AND KEEPS MOST OF THE MEASURABLE PRECIP N OF THE UPPER MICHIGAN BORDER UNTIL MID AFTERNOON. HAVE CUT BACK ON PRECIP PROB AND AMOUNTS FOR THE DAY. BAND OF VIRGA/LIGHT PRECIP IS MOVING THROUGH EASTERN PART OF FORECAST AREA PRESENTLY AND HAVE ACCOUNTED FOR THAT IN THE UPDATE. MILD AIR THAT DOWNSLOPED THE ROCKIES WL SURGE INTO THE FCST AREA LATE TDA...SO MAXES WL PROBABLY OCCUR ARND 00Z. BUT DESPITE WARMING TEMPS...STG S/SE WINDS WL MAKE IT A RATHER UNPLEASANT DAY TO BE OUTDOORS. STRONGEST SFC PRESSURE GRADIENT WL OCCUR MID- DAY...WHEN WINDS COULD GUST TO 35-40 MPH ACRS THE SRN 1/2 OF THE FCST AREA...AND EVEN HIGHER AT THE LAKESHORE. A LITTLE BIT OF A LULL IN THE WINDS WL OCCUR DURING THE EARLY EVENING...THEN THERE WL PROBABLY BE ANOTHER SURGE OF STG WINDS OVERNIGHT AS CAA SWEEPS ACRS THE AREA AND MIXES STRONGER WINDS BACK DOWN TO THE SFC. GIVEN THE EXPECTED WINDS...BUILT 3-HOURLY TEMP GRIDS FROM A BLEND OF GUID...AND THEN TOOK MINS FM THOSE. THAT TECHNIQUE TYPICALLY WORKS WELL DURING NIGHTS WITH STG WINDS. WINDS WL SLOWLY DIMINISH MON AS THE STORM PULLS AWAY FM THE RGN. .LONG TERM...MONDAY NIGHT THROUGH SATURDAY. A MAJOR WINTER STORM IS EXPECTED TO IMPACT MUCH OF WISCONSIN FROM TUESDAY AFTERNOON INTO WEDNESDAY EVENING. THE WELL ADVERTISED STORM IS EXPECTED TO ARRIVE A LITTLE SLOWER AS IT RUNS INTO LARGE HUDSON BAY HIGH. HAVE REMOVED CHANCES FOR LIGHT SNOW MONDAY NIGHT AND LOWERED CHANCES FOR SNOW TUESDAY MORNING...THEN RAISED SNOW CHANCES CONSIDERABLY TUESDAY AFTERNOON. THE BRUNT OF THE STORM WILL BE TUESDAY NIGHT INTO WEDNESDAY WITH THE SNOW TAPERING OFF OR ENDING WEDNESDAY EVENING. THE 00Z MODEL RUNS TONIGHT CONTINUE TO SHOW DIFFERENCES IN THE WARM LAYER AND HOW FAR NORTH IT WILL MAKE IT INTO WISCONSIN. THIS WILL HAVE SIGNIFICANT IMPACTS ON SNOWFALL TOTALS AND PRECIPITATION TYPES ACROSS PORTIONS OF NORTHEAST AND EAST CENTRAL WISCONSIN. THE WRF MODEL WOULD ALSO SUGGEST A DRY SLOT MOVING OVER THIS PORTION OF THE STATE THAT WOULD LIMIT SNOWFALL TOTALS FOR A PERIOD OF TIME LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. FOR TUESDAY NIGHT AND WEDNESDAY...WILL GO WITH SNOW/OCCASIONAL SNOW ACROSS MUCH OF THE AREA. CURRENT SNOW GRIDS HAVE 6 TO 13 INCHES WITH THE HIGHEST TOTALS ACROSS PORTIONS OF CENTRAL AND NORTH CENTRAL WISCONSIN... WHILE THE LOWEST AMOUNTS ARE FROM GREEN BAY AND THE FOX CITIES EAST TO THE LAKE. IF THERE IS LESS OF A WARM LAYER OR THE DRY SLOT DOES NOT MATERIALIZE ACROSS GREEN BAY AND THE FOX CITIES EAST TO THE LAKE...SNOWFALL TOTALS WILL NEED TO BE INCREASED SUBSTANTIALLY. STRONG WINDS ARE EXPECTED TUESDAY NIGHT INTO WEDNESDAY MORNING AHEAD OF THE LOW PRESSURE SYSTEM...WHICH WILL CAUSE CONSIDERABLE BLOWING AND DRIFTING OF THE SNOW. WINDS WILL DIMINISH LATER WEDNESDAY MORNING ACROSS MUCH OF THE AREA AS THE LOW MOVES ACROSS THE STATE. SINCE THE SYSTEM IS SLOWER TO EXIT THE REGION...LIGHT SNOW WILL LINGER INTO WEDNESDAY EVENING...ESPECIALLY ACROSS EASTERN WISCONSIN. SNOW CHANCES WILL PROBABLY NEED TO BE INCREASED WEDNESDAY EVENING WITH LATER FORECASTS. COULD SEE SOME MINOR ADDITIONAL ACCUMULATION ACROSS EASTERN WISCONSIN. ATTENTION THEN TURNS TO SYSTEM FRIDAY INTO FRIDAY NIGHT. THE ECMWF HAS SHIFTED THE SYSTEM EAST OF THE AREA...THE GFS CLIPS OUR EAST WHILE THE CANADIAN MODEL WOULD SUGGEST ANOTHER SNOWSTORM. LOOKING AT THE GFS ENSEMBLE MEMBERS...THERE ARE SOME ENSEMBLE MEMBERS THAT WOULD BRING THE SYSTEM FURTHER WEST. WILL CONTINUE WITH CURRENT CHANCES FOR SNOW AND LET THE MODELS CONVERGE ON A SOLUTION. && .AVIATION...FOR 18Z TAF ISSUANCE...VFR CIGS FOR MUCH OF AREA. EXCEPTIONS ARE NEAR LAKE MICHIGAN WITH CIGS AROUND 2500 FT FROM TIME TO TIME FROM STRATUS OFF LAKE MICHIGAN. IN ADDITION...THE FAR NORTH WILL SEE MVFR CIGS AND VSBYS WITH SCATTERED SNOW SHOWERS. STRONG SE WINDS WILL BECOME S THIS AFTERNOON THEN SW DURING THE EVE. GUSTS NEAR 35 KTS POSSIBLE. JKL && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
325 AM CST SUN FEB 26 2012 .TODAY AND TONIGHT...FORECAST CONFIDENCE HIGH. STRONG LOW PRESSURE OVER SOUTH DAKOTA WILL MOVE TO CENTRAL MINNESOTA BY NOON AND REACH SOUTHERN LAKE SUPERIOR THIS EVENING. THE STRONG PRESSURE GRADIENT WITH THE LOW CROSSING TO THE NORTH WILL CAUSE STRONG AND GUSTY WINDS TO DEVELOP THIS MORNING. THE SOUTHEASTERLY COMPONENT AHEAD OF THE SFC TROUGH/COLD FRONT WILL ALLOW FOR A LITTLE DEEPER MIXING NEAR THE SHORELINE...SO EXPECT HIGHEST WINDS THERE. ELSEWHERE...IT IS A LITTLE UNCERTAIN AS TO HOW FAR UP THE AIR WILL MIX. 00Z NAM AND GFS ARE SHOWING WINDS UP TO 60 KNOTS AT 850 MB BUT THE QUESTION IS HOW HIGH THE MIXED LAYER WILL GET TO. BY THE TIME LAPSE RATES INCREASE TO 5 C/KM FROM 900 MB IS THIS AFTERNOON AFTER THE CORE OF THE STRONGEST WINDS HAVE PUSHED OFF TO THE EAST. NAM FORECAST SOUNDINGS MIX 35 KNOT GUSTS AROUND NOON IN THE SOUTHEAST. RUC MIXES OUT HIGHER ALMOST TO 2 THSD FT AND MIXES GUSTS TO AROUND 40 KNOTS AT MKE. HOWEVER GIVEN SNOW COVER AND CURRENT INVERSION THIS MAY BE TO AGGRESSIVE. LAV GUST GUIDANCE KEEPS GUSTS TO 32 KNOTS. TEMPERATURES ARE ALSO TRICKY AS THE 850 MB WARM AIR ADVECTION COOLS BY AFTERNOON. THIS AND THE SNOW COVER SHOULD KEEP TEMPERATURES COOLER THAN THE MAV MOS GUIDANCE. NAM FORECAST SOUNDINGS INDICATE AT BEST MID 30S. THERE IS A SURGE OF WARMER AIR PUSHING INTO NORTHEAST MISSOURI WITH TEMPERATURES ALREADY IN THE MID 40S. GIVEN THE UNCERTAINTY OF THE LAPSE RATES IN THE LOWEST LAYERS IT MAY BE BEST TO GO WITH A WIND ADVISORY OVER PORTIONS OF SOUTHEAST WISCONSIN LEANING MORE TOWARD THE RUC. FAIRLY STRONG 700 MB UPWARD MOTION OF 9 UBAR/SEC WILL MOVE ACROSS THE FAR NORTHERN SECTIONS OF THE FORECAST AREA. HOWEVER MID LEVELS SATURATE ONLY IN THE 12 TO 18 THSD FT LAYER WITH MUCH OF THE LIFT IN THE DRIER LOW LEVELS. THEREFORE EXPECT MAINLY VIRGA WITH ONLY A FEW FLURRIES REACHING THE GROUND. EARLY TONIGHT A STRONG WEST WIND OCCURS AT 850 MB ON THE 06Z NAM...REACHING 70 KNOTS. THIS WITH STEEPER LAPSE RATES BEHIND COLD/OCCLUDED FRONT. WILL INCREASE WINDS FROM MOS FOR THIS. MONDAY - CONFIDENCE...MEDIUM COUPLE VORTS WITHIN SHORTWAVE TROUGH AXIS SHIFT EAST OF THE AREA BY EARLY AFTERNOON. HOWEVER AIRMASS QUITE DRY WITH PLENTY OF 700 DOWNWARD MOTION AND LOWER LEVEL COOL ADVECTION. 500 MILLIBAR FLOW BECOMES INCREASINGLY ANTICYCLONIC. SURFACE/850 GRADIENT SUGGESTS A NORTHWEST BREEZE WILL LIKELY PERSIST FOR MUCH OF THE MORNING BUT WITH SURFACE/850 RIDGE AXES COMING CLOSER DURING THE AFTERNOON...WINDS SHOULD EASE. TUESDAY - CONFIDENCE...MEDIUM SURFACE/850 RIDGE AXES WELL TO THE EAST. STRONG S/SE FLOW DEVELOPS IN THE LOW LEVELS. CYCLOGENESIS RAMPS UP IN RESPONSE TO HIGHLY DYNAMICAL UPPER SYSTEM APPROACHING IOWA. WARM ADVECTION INCREASES...WITH SOME DISAGREEMENT AMONGST THE MODELS ON HOW QUICK THE 850/925 LAYER WARMS. SURFACE TEMPS EXPECTED TO BE ABOVE FREEZING IF NAM SCENARIO PANS OUT WITH THE MORE PRONOUNCED WARM SURGE IN THE AFTERNOON. SOME SLEET POTENTIAL NOTED ON NAM SOUNDING AT KMSN. TUESDAY NIGHT - CONFIDENCE...MEDIUM VERY CONSISTENT SIGNALS FOR THE MAIN PRECIP EVENT THIS TIME FRAME WITH STRONG WAVE IMPINGING ON THE CWA. HIGH CONFIDENCE IN PRECIP OCCURRENCE AND LOW CONFIDENCE IN PRECIP TYPE. DIFFERENTIAL CYCLONIC VORTICITY ADVECTION ...NOSE OF 250 JET AIMED RIGHT INTO THE CWA AND CORRIDOR OF MOISTURE WITH SOUTHERLY FLOW ADVECTING HIGHER THETA-E AIR INTO SRN WI. MAIN CHALLENGE CONTINUES TO BE PRECIP TYPE. ECMWF SUGGESTS NORTHERN CWA REMAINS ALL SNOW WHILE OTHER MODELS MORE AGGRESSIVE WITH TIGHT 850 BAROCLINIC ZONE SHIFTING FURTHER NORTH OUT OF THE CWA. APPEARS THE SOUTHERN CWA WILL BE ALL RAIN WITH CONSENSUS AMONGST THE MODELS FOR A PURELY WARM PROFILE THERE...BUT THE NORTH REMAINS VULNERABLE TO THE WINTRY MIX OR ALL SNOW. PONDERED THUNDER IN PARTS OF THE SOUTH THOUGH LAPSE RATES/ELEVATED CAPE TOO MARGINAL FOR GRID INCLUSION AT THIS POINT. WEDNESDAY - CONFIDENCE...MEDIUM SURFACE/UPPER LOW PROGGD TO SHIFT ACROSS SRN WI. 700 LOW POSITION FAVORS THE NORTHERN CWA QPF MAX OF AROUND A TENTH OR A SMIDGE HIGHER. THERMAL PROFILE SUPPORTS A TRANSITION TO SOME LIGHT SNOW IN THE SOUTHERN AREAS AS WELL. THURSDAY - CONFIDENCE...MEDIUM APPEARS SHORTWAVE RIDGING WILL TAKE HOLD AND BRING A QUIET DAY IN THE WAKE OF THE PRIOR DAYS STORM SYSTEM. FRIDAY AND SATURDAY - CONFIDENCE...LOW TO MEDIUM ANOTHER UNSETTLED PERIOD AS UPPER FLOW BECOMES SOUTHWEST AND AN INITIAL WAVE RIDES NORTHEAST TOWARDS SE WI. MAIN VORT/UPPER TROUGH WILL THEN WAFFLE ACROSS WI ON SATURDAY KEEPING PRECIP CHANCES GOING. GFS A BIT MORE AGGRESSIVE ON THIS LOW RIDING NORTHEAST ALONG THE BAROCLINIC ZONE WHILE THE ECMWF IS A SKEWED A BIT MORE SOUTHEAST. && .AVIATION/12Z TAFS/...STRONG LOW PRESSURE OVER SOUTH DAKOTA WILL MOVE TO CENTRAL MINNESOTA BY NOON AND REACH SOUTHERN LAKE SUPERIOR THIS EVENING. THE STRONG PRESSURE GRADIENT WITH THE LOW CROSSING TO THE NORTH WILL CAUSE STRONG AND GUSTY WINDS TO DEVELOP THIS MORNING. SOUTH WINDS WILL INCREASE THIS MORNING WITH LOW LEVEL WIND SHEAR LIKELY. 55 KNOT WINDS DEVELOPING AROUND 2 THSD FT THIS MORNING. THE WINDS WILL BE STRONGEST FROM MID MORNING THROUGH EARLY AFTERNOON WITH THE SOUTHEAST TO SOUTH COMPONENT...THEN THEY WILL DIMINISH SLIGHTLY BEHIND THE SURFACE TROUGH AT 2 THSD FT AS THEY VEER TO THE SOUTHWEST. HOWEVER AT THE SURFACE WINDS WILL GUSTY INTO THE AFTERNOON AS LOW LEVEL LAPSE RATES INCREASE. SOME GUSTS TO 35 KNOTS POSSIBLE. EARLY TONIGHT A STRONG WEST WIND OCCURS AT 850 MB ON THE 06Z NAM...REACHING 70 KNOTS. THIS WITH STEEPER LAPSE RATES BEHIND COLD/OCCLUDED FRONT. WILL INCREASE WINDS FROM MOS FOR THIS AND MAY ALSO BRING SOME WIND SHEAR POTENTIAL. MAINLY VFR CIGS TODAY...THEN MVFR AS COLD AIR STRATOCUMULUS PUSHES IN FROM THE NORTH BEHIND THE STRONG LOW INTO AT LEAST NORTHERN PORTIONS TOWARD THE DELLS TO SHEBOYGAN LATE TONIGHT. THE MVFR CIGS COULD SAG TOWARD THE ILLINOIS BORDER TOWARDS SUNRISE MONDAY. && .MARINE...STRONG LOW PRESSURE OVER SOUTH DAKOTA WILL MOVE TO CENTRAL MINNESOTA BY NOON AND REACH SOUTHERN LAKE SUPERIOR THIS EVENING. THE STRONG PRESSURE GRADIENT WITH THE LOW CROSSING TO THE NORTH WILL CAUSE STRONG AND GUSTY WINDS TO DEVELOP THIS MORNING. A GALE WARNING IS IN EFFECT TODAY FROM 15Z TO 21Z. THIS IS THE TIME PERIOD WITH THE HIGHEST GUST POTENTIAL WITH A SOUTHEAST TO SOUTH WIND ONSHORE COMPONENT. WINDS AND GUSTS WILL DIMINISH SLIGHTLY AS WINDS VEER SOUTHWEST BEHIND THE SURFACE TROUGH/COLD FRONT. WINDS AHEAD OF LOW WILL BUILD LARGE WAVES. SMALL CRAFT ADVISORIES WILL BE NEEDED AFTER THE GALES EXPIRE DUE TO BRISK WEST WINDS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...WIND ADVISORY FROM 11 AM THIS MORNING TO 4 PM CST THIS AFTERNOON FOR WIZ060-065-066-069>072. LM...GALE WARNING FROM 9 AM THIS MORNING TO 6 PM CST THIS EVENING FOR LMZ643>646. && $$ TODAY/TONIGHT AND AVIATION/MARINE...HENTZ MONDAY THROUGH SATURDAY...COLLAR
AREA FORECAST DISCUSSION
NWS DENVER CO
925 PM MST MON FEB 27 2012 .UPDATE...LOOKING AT SOME OF THE 00Z MODELS BELIEVE THERE IS LESS OF A CHANCE THE PLAINS WILL SEE MEASURABLE PRECIPITATION TOMORROW. ALSO...LOOKS LIKE TEMPERATURES WILL BE SLIGHTLY WARMER AND WILL INTRODUCE RAIN MIXING WITH SNOW ON THE PLAINS TOMORROW AS WELL AS BUMPED UP MAX TEMPERATURES. && .PREV DISCUSSION... /ISSUED 551 PM MST MON FEB 27 2012/ SHORT TERM...HAVE MADE SOME ADJUSTMENTS TO THE TONIGHT PERIOD OF THE FORECAST. GIVEN OBSERVATIONS...HAVE BACKED OFF ON CHANCES OF SNOW IN THE MOUNTAINS THIS EVENING AS THE STRONG SOUTHWEST FLOW IS NOT CONDUCIVE TO MUCH SHOWER ACTIVITY IN OUR MOUNTAINS. HAVE ALSO ADJUSTED SKY COVER TO MOSTLY CLEAR OVER THE PLAINS EARLY THIS EVENING THEN INCREASE THE CLOUDS GIVEN THE STRATUS DEVELOPING ACROSS FAR SOUTHEAST COLORADO AND WESTERN KANSAS. CHANCES OF ANY PRECIP LOOK VERY LOW OVER EASTERN COLORADO WITH MAINLY DRY AIRMASS IN THE MID AND UPPER LEVELS. HAVE REMOVED MOST OF THE POPS. ALSO BUMPED UP WIND SPEEDS FOR TUESDAY AFTERNOON AS THE TROF SWEEPS ACROSS NORTHERN COLORADO. .AVIATION...MAIN CHANGE TO 00Z TAFS WAS TO INCREASE THE WESTERLY WINDS FOR TUESDAY AFTERNOON AS MODELS AGAIN SEEM TO BE UNDERDOING WIND SPEEDS. LATEST HRRR SHOWS DEN CYCLONE THRU THE NIGHT WITH LOW LEVEL MOISTURE WRAPPING AROUND THE LOW LATER TONIGHT WITH THE POTENTIAL FOR FOG/STRATUS OVER THE TERMINALS. STILL A CLOSE CALL AND MAYBE A BETTER CHANCE AT BJC. LEFT THE VCFG AT KDEN BUT GIVEN CYCLONE WE MAY GET MORE FOG THAN FORECAST. WILL LIKELY MAKE MORE ADJUSTMENTS THIS EVENING. NOT VERY CONFIDENT ON PRECIP OCCURRING AT LOCAL TERMINALS BUT DID LEAVE A VCSH IN FOR NOW. && .PREV DISCUSSION... /ISSUED 323 PM MST MON FEB 27 2012/ SHORT TERM...UPPER TROUGH HEADING TOWARDS THE GREAT BASIN AT THIS TIME WITH FAIRLY TIGHT SOUTHERLY FLOW ALOFT OVER THE REGION. AT THE SURFACE...GUSTY SOUTHERLY WINDS CONTINUING ACROSS THE PLAINS MAINLY FROM DENVER EASTWARD. MODELS STILL PERSISTENT WITH WEAKENING THAT GRADIENT DURING THE EVENING...WITH SURFACE WINDS DECREASING A RESULT. WILL CONTINUE THIS TREND. SATELLITE SHOWING MOISTURE CONTINUING TO SPREAD INTO WESTERN COLORADO...WITH RADAR SHOWING SOME ECHOES ACROSS THE WESTERN MOUNTAINS. NOT A LOT CURRENTLY HAPPENING OVER THE NORTHERN AND CENTRAL MOUNTAINS... PERHAPS A FEW ECHOES ACROSS ZONE 31. AS TROUGH MOVES INTO THE GREAT BASIN THIS EVENING...SHOULD SEE MOISTURE INCREASE AND SNOW SPREAD ACROSS THE AREA. SOUTHWEST FLOW ALOFT NOT FAVORABLE FOR GOOD SNOWFALL AND ACCUMULATIONS...BUT WITH INCREASING ASCENT AND LAPSE RATES...LIKELY POPS SEEM WARRANTED WITH THE HIGHEST POPS FOR FAVORED ZONE 31. SNOW AMOUNTS TO BE IN THE 1 TO 3 INCH RANGE. ACROSS PLAINS....SURFACE WINDS TO BECOME SOUTHWEST DURING THE EVENING AS THE SOUTHWEST GRADIENT INCREASES. MOISTURE TO INCREASE ACROSS THE AREA BY MIDNIGHT. LOW LEVELS SLOWING MOISTEN OVERNIGHT AS LOW LEVEL MOISTURE SPREADS NORTHWEST. QUESTION REMAINS HOW MUCH LOW LEVEL MOISTURE MAKES IT TO THE FOOTHILLS. LATEST RUC AS WELL AS THE HI RESOLUTION MODELS BRING THE LOW LEVEL MOISTURE INTO EASTERN ADAMS AND EASTERN ARAPAHOE COUNTIES AROUND 10Z...ENOUGH PERHAPS FOR PATCHY FOG. THIS ALREADY IN THE GRIDS. PRECIP CHANCES LOW OVERNIGHT...WITH THE BEST CHANCE ACROSS ZONE 38 WHERE SOME BANDED PRECIP IS POSSIBLE. MAY BE A RAIN/SNOW MIX FOR A FEW HOURS. ON TUESDAY...THE TROUGH IS EXPECTED TO MOVE ACROSS THE REGION WITH THE BEST DYNAMICS OCCURRING DURING THE MORNING. OROGRAPHICS IMPROVE DURING THE AFTERNOON BUT LIFT IS EAST OF THE MOUNTAINS AND MOISTURE DEPTH DECREASES. STILL A DECENT SHOT OF SNOW EXPECTED FOR THE MOUNTAINS...ESPECIALLY FOR THE MORNING HOURS...WITH ANOTHER 2 TO 5 INCHES. ACROSS PLAINS...BEST CHANCE FOR SNOW LOOKS TO BE DURING THE MORNING WHEN THE DYNAMICS MOVES OVERHEAD. BUT DOWNSLOPE WINDS WILL OFFSET THE SNOW POTENTIAL. SO ANY ACCUMULATION SHOULD BE LESS THAN AN INCH....MAINLY ACROSS ZONE 38. SNOW CHANCES DECREASE DURING THE AFTERNOON AS TROUGH MOVES INTO THE CENTRAL PLAINS AND DOWNSLOPE INCREASES. LATEST MODELS STILL SHOW SOME LIGHT ACCUMULATION ACROSS FAR NORTHEAST CORNER DURING THE AFTERNOON. WILL KEEP CHANCE POPS THERE...BUT AMOUNTS WILL BE LIGHT. AS FOR PRECIP TYPE...THICKNESS PROGS SUGGEST ALL SNOW. LONG TERM...A CLOSED UPPER LEVEL LOW MOVING ACROSS THE NORTHERN PLAINS WILL BRING A NORTHWEST FLOW ALOFT TO COLORADO TUESDAY NIGHT. AS THIS SYSTEM EXITS THE REGION...MOUNTAIN SNOW WILL COME TO AN END DURING THE NIGHT. A STABLE LAYER WILL FORM JUST ABOVE RIDGE TOP AND CREATE A MOUNTAIN WAVE. WINDS AT RIDGE TOP WILL BE AROUND 50 KNOTS. THE WAVE WILL ACCELERATE THESE WINDS DOWN THE FOOTHILLS RESULTING IN WIND GUSTS UP TO 80 MPH. WILL ISSUE A HIGH WIND WATCH FOR THE FOOTHILLS AND AREAS AT THE BASE OF THE FOOTHILLS FOR TUESDAY NIGHT AND EARLY WEDNESDAY MORNING. THE WINDS WILL QUICKLY DIE OFF WEDNESDAY AS AN UPPER LEVEL RIDGE QUICKLY PASSES OVER THE STATE. THIS WILL BRING MILD AND DRY CONDITIONS TO NORTHEAST COLORADO. NEXT STORM SYSTEM WILL DIG SOUTH ACROSS THE PACIFIC NORTHWEST AND NORTHERN ROCKIES THURSDAY. THIS SYSTEM WILL LIKELY BRING ANOTHER SHOT OF SNOW TO THE MOUNTAINS...THURSDAY AND FRIDAY. COLD FRONT WILL PUSH SOUTH ACROSS NORTHEAST COLORADO THURSDAY. WINDS WILL BECOME NORTHEAST BEHIND THE FRONT...PRODUCING AN UPSLOPE FLOW. WILL HAVE SCATTERED POPS IN THE FORECAST THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. THE AREA WILL BE ON THE BACKSIDE OF THIS SYSTEM ON FRIDAY. AIRMASS WILL BE SOMEWHAT UNSTABLE AND WILL KEEP LOW POPS FOR NORTHEAST COLORADO IN THE FORECAST. FOR THE MOUNTAINS...THE SLIGHTLY UNSTABLE FLOW OVER THE MOUNTAINS WILL PRODUCE SNOW SHOWERS...THUS WILL HAVE HIGHER POPS OVER THE MOUNTAINS. UPPER LEVEL RIDGE WILL BE ALONG THE WEST COAST SATURDAY. THIS WILL PRODUCE A DRY AND MILD NORTHWEST FLOW OVER COLORADO. THE RIDGE WILL SHIFT EAST THROUGH THE WEEKEND AND EARLY NEXT WEEK. THIS WILL ALLOW TEMPERATURES TO CLIMB ABOVE NORMAL SUNDAY AND MONDAY AS DRY CONDITIONS CONTINUE. ON MONDAY...SOME 60S WILL BE POSSIBLE OVER NORTHEAST COLORADO. AVIATION..STRONG SOUTHERLY GRADIENT TO SLOWLY WEAKEN ACROSS PLAINS THIS EVENING...WITH WINDS DECREASING AT DEN AND APA. WINDS TO BECOME SOUTHWEST AT ALL THE AREA AIRPORTS BY 05Z AS SOUTHWEST FLOW ALOFT INCREASES. MOISTURE TO GRADUALLY INCREASE THIS EVENING...WITH CEILINGS OF 5000-6000 FEET AGL PREVAILING. CHANCE FOR MVFR CEILINGS AT DEN AND APA AFTER 07Z IF LOW LEVEL MOISTURE INCREASES FROM THE SOUTHEAST. SLIGHT CHANCE OF SNOW SHOWERS AFTER 06Z...POSSIBLY MIXED WITH RAIN. BEST CHANCE FOR SNOW TUESDAY MORNING...AS TROUGH MOVES OVERHEAD. VFR CONDITIONS TO PREVAIL...WITH POSSIBLE MVFR CONDITIONS WITH PASSING SNOW SHOWERS. WINDS TO SHIFT TO THE NORTHWEST AFTER 16Z...CONTINUING THROUGH THE DAY WITH SOME GUSTS TO 20 KTS POSSIBLE DURING THE AFTERNOON. && .BOU WATCHES/WARNINGS/ADVISORIES... HIGH WIND WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING FOR COZ035-036-038-039. && $$ SHORT TERM...ENTREKIN LONG TERM....MEIER AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
302 AM EST TUE FEB 28 2012 .SYNOPSIS... HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE NORTH TODAY. A WARM FRONT SOUTH OF THE FORECAST AREA WILL LIFT NORTH OF THE AREA WEDNESDAY AHEAD OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL MOVE INTO THE FORECAST AREA WEDNESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LINGERING LOW-LEVEL MOISTURE WITH DRYING ALOFT HAS HELPED CAUSE DENSE FOG EARLY THIS MORNING. THE LATEST RUC AND PRESSURE RISES OCCURRING NORTH OF THE AREA SUPPORT AN INCREASE IN BOUNDARY LAYER WINDS LATER THIS MORNING. EXPECT IMPROVEMENT WILL OCCUR BEFORE 1000 AM THIS MORNING. THE DRY RIDGING SHOULD THEN BE DOMINATE DURING MUCH OF TODAY EXCEPT THE MODELS INDICATE ISENTROPIC LIFT LATER IN DAY NORTH OF A DEVELOPING WARM FRONT. EXPECT AN INCREASE IN CLOUDINESS MAINLY IN THE SOUTH PART. THE NAM MOS INDICATES RAIN MAY DEVELOP IN THE CENTRAL SAVANNAH RIVER AREA THIS AFTERNOON. THE LIFT APPEARS WEAK SO USED THE GFS MOS AND SREF GUIDANCE AND KEPT THE DRY FORECAST FOR THE ENTIRE AREA TODAY. THE TEMPERATURE GUIDANCE WAS CONSISTENT. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... CONTINUED ISENTROPIC LIFT NORTH OF THE WARM FRONT SUPPORTS POSSIBLE RAIN TONIGHT. THE MODELS KEPT THE LIFT WEAK WITH A FLAT UPPER-LEVEL PATTERN. THE NAM AND GFS MOS SUPPORT SLIGHT CHANCE OR CHANCE POPS. THE NAM LI PATTERN SUGGEST THE WARM FRONT WILL LIFT NORTH OF THE FORECAST AREA WEDNESDAY. USED THE GFS AND NAM MOS AND FORECASTED A SMALL CHANCE OF SHOWERS BECAUSE OF WEAK ISENTROPIC LIFT AND CONVERGENCE NEAR THE WARM FRONT. THE CHANCE APPEARS LIMITED BECAUSE OF THE WEAK LIFT...SHALLOW MOISTURE...AND A FLAT UPPER-LEVEL PATTERN. THE NAM AND GFS SHOW A WEAKENING COLD FRONT APPROACHING THE FORECAST AREA WEDNESDAY NIGHT. CHANCE POPS AS INDICATED BY THE GFS AND NAM MOS APPEARS REASONABLE BECAUSE OF DIMINISHING CONVERGENCE ASSOCIATED WITH THE WEAKENING FRONT AND LITTLE UPPER-LEVEL LIFT. DESPITE THE WEAKENING CONVERGENCE THE NAM AND GFS ARE IN GOOD AGREEMENT SHOWING HIGH SHEAR WITH H85 WINDS OF 40 TO 50 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S OF -1 TO -3. THIS COMBINATION OF SHEAR AND INSTABILITY SUPPORTS POSSIBLE SEVERE WIND GUSTS AND WE HAVE NOTED THE THREAT IN THE HAZARDOUS WEATHER OUTLOOK. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURES EXCEPT THE WARMER VALUES APPEAR BETTER WEDNESDAY NIGHT BECAUSE OF CLOUDINESS AND MIXING AHEAD OF THE FRONT. && .LONG TERM /THURSDAY THROUGH MONDAY/... THE GFS SHOWS THE FRONT STALLING AND BECOMING DIFFUSE IN THE FORECAST AREA THURSDAY. DEEPER MOISTURE APPEARS TO SHIFT SOUTH AND EAST OF THE AREA. THE FRONT APPEARS TO BECOME A WARM FRONT FRIDAY WITH AN INCREASE IN MOISTURE. THIS WARM FRONT SHOULD LIFT NORTH OF THE FORECAST AREA AHEAD OF THE NEXT COLD FRONT. THE GFS AND ECMWF SHOW THIS COLD FRONT IN THE FORECAST AREA SATURDAY. STRONG SHEAR AND SOME INSTABILITY WILL LIKELY BE ASSOCIATED WITH THIS FRONT SUPPORTING A THREAT OF SEVERE THUNDERSTORMS. DRYING BEHIND THE FRONT SHOULD DOMINATE SUNDAY AND MONDAY. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... WIDESPREAD LIFR CONDITIONS AREAWIDE IN DENSE FOG. AFTERNOON STRATUS HAS PUSHED EAST OF ALL TERMINALS EXCEPT OGB AND THE CLEARING HAS ALLOWED TEMPERATURES TO FALL AND WIDESPREAD FOG HAS DEVELOPED. EXPECT LIFR CONDITIONS TO PERSIST THROUGH 12Z-14Z BEFORE FOG LIFTS AND CIGS/VSBYS RETURN TO VFR BY 16Z. WINDS WILL REMAIN NEAR CALM OVERNIGHT BEFORE PICKING UP OUT OF THE NORTHEAST AROUND 10 MPH AFTER 15Z. HIGH CLOUDS WILL BLANKET THE AREA BY LATE AFTERNOON AND LOWER VFR CIGS WILL RETURN AFTER 00Z ASSOCIATED WITH WARM ADVECTION AHEAD OF THE NEXT WEATHER SYSTEM. MVFR CIGS ARE POSSIBLE TOWARDS THE END OF THE FORECAST PERIOD BUT CONFIDENCE IS LOW OUTSIDE OF AGS/DNL. EXTENDED AVIATION OUTLOOK...IFR/MVFR CONDITIONS POSSIBLE WED/WED NT INTO EARLY THU...EARLY FRI...AND AGAIN SAT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
119 AM EST TUE FEB 28 2012 .SYNOPSIS... HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE NORTH TODAY. A WARM FRONT SOUTH OF THE FORECAST AREA WILL LIFT NORTH OF THE AREA WEDNESDAY AHEAD OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL MOVE INTO THE FORECAST AREA WEDNESDAY NIGHT. && .NEAR TERM /THROUGH TODAY/... LINGERING LOW-LEVEL MOISTURE WITH DRYING ALOFT HAS HELPED CAUSE DENSE FOG EARLY THIS MORNING. THE LATEST RUC AND PRESSURE RISES OCCURRING NORTH OF THE AREA SUPPORT AN INCREASE IN BOUNDARY LAYER WINDS LATER THIS MORNING. EXPECT IMPROVEMENT WILL OCCUR BEFORE 1000 AM THIS MORNING. THE DRY RIDGING SHOULD THEN BE DOMINATE DURING MUCH OF TODAY EXCEPT THE MODELS INDICATE ISENTROPIC LIFT LATER IN DAY NORTH OF A DEVELOPING WARM FRONT. EXPECT AN INCREASE IN CLOUDINESS MAINLY IN THE SOUTH PART. THE NAM MOS INDICATES RAIN MAY DEVELOP IN THE CENTRAL SAVANNAH RIVER AREA THIS AFTERNOON. THE LIFT APPEARS WEAK SO USED THE GFS MOS AND SREF GUIDANCE AND KEPT THE DRY FORECAST FOR THE ENTIRE AREA TODAY. THE TEMPERATURE GUIDANCE WAS CONSISTENT. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... CONTINUED ISENTROPIC LIFT NORTH OF THE WARM FRONT SUPPORTS POSSIBLE RAIN TONIGHT. THE MODELS KEPT THE LIFT WEAK WITH A FLAT UPPER-LEVEL PATTERN. THE NAM AND GFS MOS SUPPORT SLIGHT CHANCE OR CHANCE POPS. THE NAM LI PATTERN SUGGEST THE WARM FRONT WILL LIFT NORTH OF THE FORECAST AREA WEDNESDAY. USED THE GFS AND NAM MOS AND FORECASTED A SMALL CHANCE OF SHOWERS BECAUSE OF WEAK ISENTROPIC LIFT AND CONVERGENCE NEAR THE WARM FRONT. THE CHANCE APPEARS LIMITED BECAUSE OF THE WEAK LIFT...SHALLOW MOISTURE...AND A FLAT UPPER-LEVEL PATTERN. THE NAM AND GFS SHOW A WEAKENING COLD FRONT APPROACHING THE FORECAST AREA WEDNESDAY NIGHT. CHANCE POPS AS INDICATED BY THE GFS AND NAM MOS APPEARS REASONABLE BECAUSE OF DIMINISHING CONVERGENCE ASSOCIATED WITH THE WEAKENING FRONT AND LITTLE UPPER-LEVEL LIFT. DESPITE THE WEAKENING CONVERGENCE THE NAM AND GFS ARE IN GOOD AGREEMENT SHOWING HIGH SHEAR WITH H85 WINDS OF 40 TO 50 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S OF -1 TO -3. THIS COMBINATION OF SHEAR AND INSTABILITY SUPPORTS POSSIBLE SEVERE WIND GUSTS AND WE HAVE NOTED THE THREAT IN THE HAZARDOUS WEATHER OUTLOOK. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURES EXCEPT THE WARMER VALUES APPEAR BETTER WEDNESDAY NIGHT BECAUSE OF CLOUDINESS AND MIXING AHEAD OF THE FRONT. && .LONG TERM /THURSDAY THROUGH MONDAY/... THE GFS SHOWS THE FRONT STALLING AND BECOMING DIFFUSE IN THE FORECAST AREA THURSDAY. DEEPER MOISTURE APPEARS TO SHIFT SOUTH AND EAST OF THE AREA. THE FRONT APPEARS TO BECOME A WARM FRONT FRIDAY WITH AN INCREASE IN MOISTURE. THIS WARM FRONT SHOULD LIFT NORTH OF THE FORECAST AREA AHEAD OF THE NEXT COLD FRONT. THE GFS AND ECMWF SHOW THIS COLD FRONT IN THE FORECAST AREA SATURDAY. STRONG SHEAR AND SOME INSTABILITY WILL LIKELY BE ASSOCIATED WITH THIS FRONT SUPPORTING A THREAT OF SEVERE THUNDERSTORMS. DRYING BEHIND THE FRONT SHOULD DOMINATE SUNDAY AND MONDAY. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... WIDESPREAD LIFR CONDITIONS AREAWIDE IN DENSE FOG. AFTERNOON STRATUS HAS PUSHED EAST OF ALL TERMINALS EXCEPT OGB AND THE CLEARING HAS ALLOWED TEMPERATURES TO FALL AND WIDESPREAD FOG HAS DEVELOPED. EXPECT LIFR CONDITIONS TO PERSIST THROUGH 12Z-14Z BEFORE FOG LIFTS AND CIGS/VSBYS RETURN TO VFR BY 16Z. WINDS WILL REMAIN NEAR CALM OVERNIGHT BEFORE PICKING UP OUT OF THE NORTHEAST AROUND 10 MPH AFTER 15Z. HIGH CLOUDS WILL BLANKET THE AREA BY LATE AFTERNOON AND LOWER VFR CIGS WILL RETURN AFTER 00Z ASSOCIATED WITH WARM ADVECTION AHEAD OF THE NEXT WEATHER SYSTEM. MVFR CIGS ARE POSSIBLE TOWARDS THE END OF THE FORECAST PERIOD BUT CONFIDENCE IS LOW OUTSIDE OF AGS/DNL. EXTENDED AVIATION OUTLOOK...IFR/MVFR CONDITIONS POSSIBLE WED/WED NT INTO EARLY THU...EARLY FRI...AND AGAIN SAT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1136 PM EST MON FEB 27 2012 .SYNOPSIS... HIGH PRESSURE TO THE WEST WILL QUICKLY BUILD EAST OVER THE AREA TONIGHT. THE HIGH WILL MOVE TO THE EAST COAST BY LATE TUESDAY. ANOTHER STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS THE CENTRAL GREAT LAKES WEDNESDAY INTO THURSDAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... TWEAKED CLOUD COVER AS CLOUDS OVER SE LOWER MICHIGAN BEGINNING TO ERODE. TWEAKED OVERNIGHT LOWS DOWN A DEGREE OR TWO. PREVIOUS DISCUSSION... BIG ISSUE IN THE SHORT TERM WILL BE THE WINDS THIS EVENING IN RESPONSE TO A RATHER TIGHT GRADIENT BETWEEN LOW PRESSURE OVER THE NORTHERN GREAT LAKES AND STRONG HIGH PRESSURE OVER THE PLAINS QUICKLY BUILDING TOWARD THE AREA. HAVE EXPANDED THE WIND ADVISORY ACROSS EASTERN COUNTIES WITH EXCEPTION FOR THE FAR SOUTH THROUGH THIS EVENING. HRRR MODEL RUNS HAVE BEEN HANDLING THE WINDS RATHER WELL THIS AFTERNOON...AND THEY HAVE ADVISORY WIND GUSTS PUSHING THROUGH NORTHEAST OHIO COUNTIES OVER THE NEXT SEVERAL HOURS. WINDS SHOULD DIMINISH QUICKLY FROM WEST TO EAST ESPECIALLY AFTER SUNSET TONIGHT. AFTER MIDNIGHT EXPECTING WINDS TO BE DOWN BELOW 10 MPH. ASIDE FROM THAT A DRY AND MOSTLY CLEAR NIGHT EXPECTED WITH TEMPS DROPPING BACK TO THE LOWER TO MID 20S. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... HIGH PRESSURE OVER THE AREA TUESDAY MORNING...THEN MOVING TO THE EAST WILL ALLOW FOR A QUIET AND DRY WEATHER DAY WITH SEASONABLE TEMPERATURES. LATEST MODELS SEEM TO BE DELAYING THE ONSET OF THE PRECIP ACROSS THE AREA TUESDAY NIGHT. WHILE CLOUDS ARE EXPECTED TO OVERSPREAD THE REGION EARLY ON...THINKING PERHAPS NOT TOWARD 06Z ACROSS THE SOUTHWEST AREAS AND NOT UNTIL CLOSE TO 12Z WED FOR PRECIP ACROSS NW PA. DO BRING UP POPS QUICKLY ACROSS THE AREA THOUGH AFTER 06Z. STILL SOME QUESTION AS TO PRECIP TYPE AT THE ONSET ESPECIALLY FROM CLE-CAK NORTHEAST. ACROSS OH THINKING THAT THERE MAY BE A RAIN/SNOW MIX WITH BEST CONFIDENCE OF ALL SNOW AT THE ONSET FOR FAR NE OH AND NW PA. MODELS SHOWING LOWER LEVELS WARMING UP ENOUGH BY 12Z WED THOUGH THAT MANY LOCATIONS WILL SWITCH OVER TO RAIN. MODELS LEANING TOWARD A MORE NORTHERN TRACK OF THE LOW CENTER ALLOWING MUCH OF THE AREA TO GET WARM ON WED. LEFT THE HIGH POPS AND MENTION OF THUNDER IN THE MORNING...BUT THEN CONCERNED ABOUT DRY SLOT MOVING ESPECIALLY INTO WESTERN AREAS FOR THE AFTERNOON SO REDUCED POPS AND CLOUDS A BIT ACROSS THE WEST. TEMPS WILL ALSO BE TRICKIEST DURING WED SO FOR NOW USED A BLEND OF MAV AND MET NUMBERS. CONCERNED MOST ABOUT NORTHERN AREAS WHICH MAY GET WARMER THAN FORECAST. ALSO CONCERNED ABOUT WIND POTENTIAL ON WED ESPECIALLY ACROSS THE WEST WHERE BETTER MIXING IS POSSIBLE. LOW PRESSURE NORTH OF THE AREA WEDNESDAY NIGHT AND THROUGH MUCH OF THURSDAY WILL ALLOW FOR SOME RAIN/SNOW SHOWERS MAINLY ACROSS THE NORTH WEDNESDAY NIGHT...THEN CONTINUED CHANCES FOR SHOWERS ACROSS NE OH AND NW PA THROUGH MUCH OF THURSDAY. HIGH PRESSURE RIDGING IN WILL DRY OUT THE AREA THURSDAY NIGHT. && .LONG TERM /FRIDAY THROUGH MONDAY/... SOUTHERLY WINDS WILL BE ON THE INCREASE ON FRIDAY AS LOW PRESSURE MOVES FROM THE CENTRAL PLAINS TO THE CENTRAL GREAT LAKES BY FRIDAY EVENING. THIS WILL PROVIDE WARM CONDITIONS FOR THE REGION WITH HIGHS INTO THE 50S FOR MOST LOCATIONS. RAIN CHANCES WILL BE ON THE INCREASE FRIDAY EVENING INTO THE OVERNIGHT. SOME RAIN MAY LINGER INTO SATURDAY MORNING. COOLER AIR WILL SPILL ACROSS THE LAKE SATURDAY NIGHT INTO EARLY SUNDAY AND COULD BE JUST COLD ENOUGH TO PROVIDE A FEW SNOW SHOWERS OFF OF LAKE ERIE. ANOTHER FAST MOVING STORM SYSTEM MAY AFFECT THE REGION SUNDAY NIGHT AND MAY ENHANCE ANY SNOW SHOWERS THAT ARE IN THE AREA. SLIGHTLY COOLER ON SATURDAY WITH HIGHS BACK INTO THE 40S. EVEN COOLER BY SUNDAY INTO MONDAY WITH HIGHS AT MOST LOCATIONS WITHIN A COUPLE DEGREES OF 40. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... CEILINGS AROUND 3 KFT CONTINUE TO AFFECT THE TOLEDO AREA HOWEVER THE DECK OF STRATUS HAS BEEN SHRINKING THROUGH THE EVENING. EXPECT THIS TREND TO CONTINUE AND WILL BREAK UP AND CLEAR OUT THE TOL TERMINAL AT 08Z. STRATUS DECK AROUND ERI LIKEWISE WILL DRIFT SOUTH AND EAST AROUND 09Z. OTHERWISE HIGH PRESSURE CONTINUE TO BUILD IN OVERNIGHT AND TUESDAY MORNING BEFORE DRIFTING EAST. TUESDAY AFTERNOON HIGH LEVEL MOISTURE WILL BEGIN TO INCREASE AND LOWER AS A WARM FRONT APPROACHES FROM THE SOUTHWEST. AFTER 09Z WEDNESDAY BROUGHT MVFR RAIN INTO THE CLEVELAND. OUTLOOK...PERIODS OF NON-VFR WILL RETURN TUESDAY NIGHT AND CONTINUE AT TIMES THROUGH THURSDAY. NON-VFR ALSO POSSIBLE FRIDAY NIGHT INTO SATURDAY. && .MARINE... A COLD FRONT MOVING ACROSS LAKE ERIE THIS AFTERNOON IS RESPONSIBLE FOR STRONG WESTERLY WINDS OF 20 TO 30 KNOTS. WINDS ARE APPROACHING GALE FORCE ON THE EAST END OF THE LAKE BUT SHOULD REMAIN JUST BELOW GIVEN THAT THE COLD ADVECTION BEHIND THE FRONT IS NOT THAT STRONG. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL NEARSHORE WATERS AND WILL COME TO AN END FROM WEST TO EAST OVERNIGHT AS HIGH PRESSURE BUILDS OVERHEAD AND WINDS/WAVES QUICKLY DECREASE. EASTERLY WINDS WILL INCREASE ON TUESDAY NIGHT AHEAD OF THE NEXT LOW PRESSURE SYSTEM TRACKING OUT OF THE PLAINS. WE WILL HAVE TO MONITOR THE EXACT TRACK AND STRENGTH OF THE SURFACE LOW FROM WEDNESDAY INTO THURSDAY TO DETERMINE MOST LIKELY WINDOW OF SMALL CRAFT ADVISORY CONDITIONS. A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED ON THE EAST END OF THE LAKE FOR THURSDAY BUT MAY NEED TO BE EXPANDED TO THE WEST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR LEZ144>149. && $$ SYNOPSIS...ABE NEAR TERM...ABE SHORT TERM...ABE/DJB LONG TERM...MULLEN AVIATION...TK MARINE...KEC
AREA FORECAST DISCUSSION
NWS NORMAN OK
1128 PM CST MON FEB 27 2012 .AVIATION... LOW CEILINGS AND VISIBILITIES NOW APPEAR THAT THEY WILL HOLD OFF UNTIL ABOUT 12-15Z TOMORROW...EXCEPT ALONG THE W BORDER OF OK...WHERE THE DETERIORATION OF CONDITIONS WILL OCCUR EARLIER. SCT PATCHES OF -RA/-DZ MAY ALSO CAUSE BRIEF DROPS IN CEILING/VISIBILITY OVERNIGHT. MORE SOLIDLY IFR TO LOW MVFR CONDITIONS ARE EXPECTED FROM 12Z TO 21Z. AFTER 21Z...THE DRY LINE WILL ADVANCE E...POSSIBLY HELPING TO SET OFF SOME TSRA IN C AND E OK. CLEARING CONDITIONS WILL FOLLOW THE DRY LINE AS IT ADVANCES FAIRLY QUICKLY E IN THE LATE AFTERNOON/EARLY EVENING. && .PREV DISCUSSION... /ISSUED 906 PM CST MON FEB 27 2012/ DISCUSSION... DEW POINT TEMPERATURES WERE RAISED SLIGHT IN LINE WITH TRENDS AND THE RUC FORECAST OVERNIGHT. OTHERWISE LITTLE CHANGES ARE NECESSARY. MOISTURE WILL INCREASE SLOWLY ACROSS THE SOUTHWEST HALF OF OKLAHOMA TO THE SOUTH OF A WEAK STATIONARY FRONT. LIGHT RAIN THAT IS OCCURRING IN THE EASTERN TEXAS PANHANDLE WILL LIKELY ALSO DEVELOP FARTHER EAST WITH INCREASING LOW LEVEL WINDS OVER THE FRONT. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 51 65 39 69 / 40 70 20 0 HOBART OK 51 71 38 67 / 60 60 10 0 WICHITA FALLS TX 55 76 42 71 / 60 50 20 0 GAGE OK 45 69 33 65 / 60 60 10 0 PONCA CITY OK 50 65 37 62 / 40 70 30 10 DURANT OK 52 68 51 72 / 30 40 40 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR OKZ004-005-009-010-014>016-021-022-033>037. WIND ADVISORY FROM 10 AM TO 7 PM CST TUESDAY FOR OKZ004>006- 009>011-014>016-021-022-033>036. TX...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR TXZ083>085-087-088. WIND ADVISORY FROM 10 AM TO 7 PM CST TUESDAY FOR TXZ083-084-087. && $$ 09/23/23
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1048 AM EST Tue Feb 28 2012 .UPDATE... This mornings total column RUC analysis shows rather zonal flow through the middle to upper levels, transitioning to ridging from the middle levels to the surface. Locally, we reside on the southern periphery of the surface ridge, placing our area under an easterly flow regime. With bountiful moisture in place, a mixture of fog and low ceilings were able to develop overnight, through this morning. The fog is finally beginning to dissipate in most locations, however, the low clouds will not respond the same. Expect the low clouds to stick around for most if not all of the day today. A few breaks in the cloud cover are possible late this afternoon along the immediate coastline and along and east of a line from Cape San Blas north through Valdosta. As we transition to weak ridging, higher heights will allow the atmosphere to warm, even in the presence of the solid deck of clouds. However, have nudged temperatures down just slightly for this afternoon. Expect middle to upper 70s southeast of the aforementioned cloud line, and lower 70s northeast of the line. Rain chances will primarily be confined to the western/northwestern portions of our CWA where a more southerly flow component near the eastern edge of the ridge will allow for some light isentropic showers to develop. Expect very little (if any) rain south of the FL/AL & FL/GA state lines. && .AVIATION... Fog dissipation has been slightly slower than originally thought this morning. Most terminals have returned to MVFR visibilities, with the exception of KDHN. However, this is somewhat irrelevant due to the IFR ceilings in place region-wide. Expect the IFR ceilings to persist through the first part of the afternoon. After 18z, or possibly 21z, ceilings will predominantly be MVFR region-wide, with the possibility of some VFR scattering at KTLH, KECP, and KVLD. Expect a mixture of fog and low ceilings once again tonight. This threat will be addressed further in the afternoon TAF package. && .TAE WATCHES/WARNINGS/ADVISORIES... AL...None. GA...None. FL...None. GM...None. && $$ Harrigan
AREA FORECAST DISCUSSION
NWS MIAMI FL
1011 AM EST TUE FEB 28 2012 .UPDATE... LATEST SURFACE ANALYSIS SHOWS WEAK FRONTAL SYSTEM OFF THE MID ATLANTIC STATES STRETCHING SW AND WEST ACROSS THE SOUTHEAST. LARGE AREA OF FOG ASSOCIATED WITH THIS SYSTEM EXTENDED THIS MORNING AS FAR SOUTH AS CENTRAL FLORIDA AND DOWN THE SOUTHWEST FLORIDA COAST. AT THE MID LEVELS SHORT WAVE TROUGH RESPONSIBLE FOR YESTERDAY`S CONVECTION IS NOW EAST OF THE PENINSULA WITH LOW AND MID LEVEL RIDGE NOW BEGINNING TO BUILD INTO THE REGION FROM THE SOUTHWEST. LOOKING AT THE 12Z MODIFIED CONVECTIVE PARAMETERS THE LOW LEVEL INSTABILITY REMAINS VERY LIMITED AS IT WAS YESTERDAY. THAT COMBINED WITH WARMER AND LESS STEEP MID LEVEL LAPSE RATES MEAN THE POTENTIAL FOR CONVECTION TODAY IS LESS. IN FACT, LOOKING AT AN ENSEMBLE OF HI RES MODELS THAT INCLUDE THE NATIONAL ARW AND NMM EAST, THE LOCAL ARW AND NMM RUNS, AND THE HRRR SUPPORT THE CURRENT FORECAST WITH POPS RANGING FROM 10 PERCENT EASTERN PART OF THE CWA TO 20-30 PERCENT INTERIOR AND WEST COAST THIS AFTERNOON AND EARLY EVENING WITH THE CAVEAT THAT THAT MIGHT BE GENEROUS GIVEN LOCAL WRF CONFIGURATIONS AND THE HRRR KEEP US MOSTLY DRY. SO CURRENT FORECAST LOOKS ON TRACK WITH NO CHANGE IN OUTLOOK AS FAR AS POTENTIAL HAZARDOUS/IMPACT WEATHER CONDITIONS FROM THIS MORNING ASSESSMENT. MODIFIED SKY CONDITION GRIDS TO MORE ACCURATELY REFLECT THIS MORNING TRENDS. && .PREV DISCUSSION... /ISSUED 558 AM EST TUE FEB 28 2012/ AVIATION...HIGH PRES CENTERED OVR THE OH RVR VLY WL MOV E OVR NEW ENGLAND AND THE MID ATLC COAST TONIGHT AND OVER THE ATLC OVR THE NXT 24 HRS. THIS KEEPS AN E-ESE WND FLOW OVR S FLA THRU THE PD. VFR THRU THE PD THOUGH SOME ERLY MORN SHRA WITH BRIEF MVFR CIG WITH NO VSBY RESTRICTION THRU 15Z. MIFG PSBL AT KAPF FM TO 13Z. SFC WNDS E COAST 3 TO 6 MPH ATTM BCMG 8-11 KTS WITH SOME GUSTS PSBL TO MID TEENS AFT 14Z. AT KAPF...CALM WNDS BCMG ENE-E < 1- KTS WITH W COAST SEA BRZE DVLPG AFT 19Z WITH WNDS BCMG SW-WSW ARND 10 KTS. SKC THEN BCMG SCT030 AFT 15Z WITH VCTS AFT 20Z. PREV DISCUSSION... /ISSUED 246 AM EST TUE FEB 28 2012/ DISCUSSION...MID LEVEL TROUGH THAT PROVIDED AFTERNOON/EVENING CONVECTION ACROSS THE LAKE REGION TO COASTAL COLLIER COUNTY NOW EXITING TO THE EAST WITH THE SHRA ACTIVITY RAPIDLY DISSIPATING. EVEN THOUGH THIS TROUGH IS LEAVING THE REGION, FCST SOUNDINGS INDICATE RESIDUAL MOISTURE REMAINING IN PLACE ALONG WITH WEAK/MODERATE INSTABILITY. MOST MODELS INCLUDING THE GFS, NAM AND RAPID REFRESH SHOW AFTERNOON CONVECTION DEVELOPING IN THE EASTERLY FLOW ACROSS INTERIOR S FL AND THEN MOVING TOWARDS THE WEST. THUS HAVE INDICATED THIS IN THE GRIDS AND EVEN THOUGH THE INSTABILITY WILL BE MARGINAL, CANNOT RULE OUT AN OCCASIONAL LIGHTNING STRIKE SO ALSO ADDED THUNDER POSSIBLE. BY TONIGHT THROUGH THURSDAY, SEVERAL STRONG MID LEVEL TROUGHS WILL MOVE ACROSS THE NORTHERN TIER OF STATES IN THE ZONAL FLOW PATTERN WITH THE SUBTROPICAL RIDGE BUILDING BACK OVER THE FL PENINSULA. THIS WILL RESULT IN BENIGN WX CONDITIONS THROUGH THAT PERIOD WITH TEMPERATURES REMAINING ABOVE CLIMATOLOGICAL AVERAGES. AT THE SFC, A SFC RIDGE ACROSS THE SOUTHEAST STATES WILL SLOWLY SHIFT TO S FL BY THURSDAY AND THIS WILL PROVIDE FOR THE EASTERLY FLOW TO WEAKEN SIGNIFICANTLY OVER THE NEXT FEW DAYS WITH THE THREAT FOR RIP CURRENTS AT THE ATLANTIC BEACHES TO LESSEN AND THE CHANCES FOR INTERIOR LATE NIGHT FOG TO INCREASE. LOOKING AHEAD TO NEXT WEEKEND, A STRONGER TROUGH WILL MOVE INTO THE GREAT LAKES REGION AND CARVE OUT A LARGER SCALE TROUGH ACROSS THE EASTERN STATES WITH ITS ASSOCIATED COLD FRONT MOVING DOWN THE PENINSULA. THE PARENT LOW PRESSURE WILL REMAIN WELL NORTH OF THE REGION ALONG WITH THE MAIN DYNAMICS WITH THE FRONT LACKING MUCH PUSH BY THE TIME IT REACHES S FL BY LATE IN THE WEEKEND. STILL A FEW DEGREES OF COOLING CAN BE EXPECTED SUNDAY NIGHT AND MONDAY WITH CHANCES OF RAINFALL LOOKING MINIMAL. MARINE...THE EASTERLY WIND WILL CONTINUE AND DIMINISH THROUGH TODAY BECOMING SOUTHEAST ON WEDNESDAY AND THEN SOUTH ON SATURDAY AHEAD OF THE APPROACHING FRONT. SEAS WILL GENERALLY BE 4 FT OR LESS THROUGH THE PERIOD. FIRE WEATHER...NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 82 71 83 69 / 10 - - - FORT LAUDERDALE 83 73 82 73 / 10 - - - MIAMI 84 72 83 72 / 10 - - - NAPLES 86 66 85 65 / 30 20 - - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...52/PS AVIATION/RADAR...59/RM
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
ISSUED BY NATIONAL WEATHER SERVICE COLUMBIA SC 1033 AM EST TUE FEB 28 2012 .SYNOPSIS... A COLD FRONT HAS MOVED OFFSHORE AND HIGH PRESSURE WILL BUILD ACROSS THE AREA THIS AFTERNOON. A WARM FRONT WILL LIFT NORTH THROUGH THE AREA WEDNESDAY MORNING...FOLLOWED BY THE PASSAGE OF A WEAK COLD FRONT EARLY THURSDAY WHICH WILL THEN STALL SOUTH OF THE AREA INTO THURSDAY NIGHT. THE FRONT WILL RETURN NORTH AS A WARM FRONT ON FRIDAY...WITH A MUCH STRONGER COLD FRONT EXPECTED TO MOVE THROUGH ON SATURDAY. HIGH PRESSURE WILL THEN BUILD OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LOW CLOUDS AND FOG DISSIPATED FROM THIS MORNING AS HIGH PRESSURE WAS BUILDING ACROSS THE REGION. MORNING SUN INCREASED TEMPERATURES INTO THE LOWER 60S IN MANY LOCATIONS...HELPING TO CLEAR SKIES OUT. LOWERED SKY COVER GRIDS TO MAINLY PARTLY CLOUDY. UPPED THE HOURLY TEMPERATURES 1-2 DEGREES USING THE RUC MODEL AND ADJUST HIGH TEMPERATURES USING THE MAX TEMP SMART TOOL. SUBJECT COLD FRONT NOW OVER THE MOUNTAINS OF WESTERN NORTH AND SOUTH CAROLINA...TEMPORARILY HUNG UP BEHIND A BUBBLE HIGH LOCATED OVER THE CAROLINA PIEDMONT REGION. GUIDANCE DROPS FRONT RAPIDLY SE ACROSS THE COASTAL PLAIN THIS MORNING AND WELL OFFSHORE BY DAYBREAK. THE FRONT STALLS OFFSHORE...BENDING BACK TOWARDS SC AND GA THIS AFTERNOON AS A SERIES OF WEAK FRONTAL WAVES DEVELOP AND MOVE ALONG THE BOUNDARY. DAYLIGHT HOURS WILL BE PLEASANT..WITH SKIES BECOMING PARTLY CLOUDY LATER THIS MORNING AS A DRYER AIR MASS MOVES IN OVER SOUTH CAROLINA AND GEORGIA IN WAKE OF THE COLD FROPA. MODEL SOUNDINGS SHOW A RETURN TO LOW LEVEL MOISTURE AND RESULTANT CLOUDINESS OVERNIGHT AS EASTERLY FLOW ADVECTS IN AND TRAPS ATLANTIC MOISTURE UNDER A SUBSIDENCE INVERSION. WARM FRONT APPROACHING FROM THE WEST MAY PROVIDE JUST ENOUGH LIFT FOR SOME LIGHT SHOWER ACTIVITY TOWARDS DAYBREAK WEDNESDAY MORNING OVER THE NORTHERN FRINGES OF THE FORECAST AREA. MODEL CONSENSUS GIVES TEMPERATURES IN THE LOWER 70S TODAY AND LOWER TO MOD 50S OVERNIGHT. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... A WEAK WARM FRONT WILL LIFT NORTH WEDNESDAY MORNING. A WEAK COASTAL TROUGH WILL PERSIST OFF THE SC COAST BUT ANY SHOWERS WILL BE REFINED TO THE COASTAL WATERS SINCE THE DEEP MOISTURE WILL HAVE CLEARED OUT. CLOUDINESS WILL BRIEFLY THIN OUT ON TUESDAY BEFORE FILLING BACK IN LATE IN THE AFTERNOON AND INCREASING FURTHER TUESDAY NIGHT WITH THE WARM FRONT LIFTING NORTH. HIGHS WILL BE AROUND 70 ACROSS MOST OF THE AREA...WITH WARM AIR ADVECTION AND CLOUD COVER KEEPING LOWS GENERALLY IN THE 50-55 DEGREE RANGE TUESDAY NIGHT. UPPER LEVEL RIDGING WILL PERSIST OVER THE REGION THROUGH MUCH OF WEDNESDAY BEFORE FLATTENING OUT AND ALLOWING SEVERAL EMBEDDED SHORTWAVES TO MOVE THROUGH CENTRAL SC. MEANWHILE THE SURFACE HIGH WILL SHIFT OFF THE COAST AND ALLOW STRONG WARM MOIST ADVECTION TO DEVELOP IN RESPONSE. A COLD FRONT ASSOCIATED WITH A DEEP GREAT LAKES SURFACE LOW WILL DROP SOUTHEAST INTO THE AREA WEDNESDAY NIGHT. DESPITE CONSIDERABLE CLOUDINESS ON WEDNESDAY...THICKNESS ADVECTION SHOULD ALLOW HIGH TEMPS TO REACH THE MID 70S NORTH TO LOWER 80S SOUTH. ALTHOUGH LOW-LEVEL DEWPOINTS WILL RISE TO AROUND 60F WEDNESDAY AFTERNOON...THE SYNOPTIC FORCING DOES NOT ARRIVE UNTIL THE EVENING AND OVERNIGHT HOURS. WE HAVE KEPT WEDNESDAY DRY WITH A SLIGHT CHANCE OF SHOWERS MOVING IN DURING THE EVENING AND 20-30 POPS OVERNIGHT. THERE SHOULD BE JUST ENOUGH INSTABILITY TO JUSTIFY KEEPING ISOLATED THUNDERSTORMS IN THE FORECAST. A SLIGHT RISK OF SEVERE THUNDERSTORMS IS FORECAST BY THE STORM PREDICTION CENTER JUST NORTHWEST OF THE AREA WEDNESDAY NIGHT...BUT GIVEN THE UNFAVORABLE TIMING AND WEAKENING STATE OF THE FRONT...WE DO NOT PLAN ON MENTIONING ANY SEVERE WEATHER IN THE HAZARDOUS WEATHER OUTLOOK AT THIS TIME. THURSDAY...THE WEAK COLD FRONT WILL PUSH THROUGH THE AREA IN THE MORNING...THEN STALL JUST SOUTH OF THE AREA AS IT BECOMES NEARLY PARALLEL TO THE UPPER LEVEL FLOW. THERE MAY BE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE MORNING WITH ITS PASSAGE...BUT DRIER AIR SHOULD MOVE IN ENDING ANY SHOWERS BY AFTERNOON. DESPITE THE PASSAGE OF THE FRONT...A DOWNSLOPE FLOW AND CLEARING SKIES WILL ALLOW FOR SLIGHTLY WARMER TEMPERATURES THAN WEDNESDAY WITH HIGHS WELL INTO THE UPPER 70S. && .LONG TERM /THURSDAY THROUGH MONDAY/... MEDIUM RANGE GUIDANCE IS IN RELATIVELY GOOD AGREEMENT THROUGH THE LONG TERM PERIOD. SURFACE HIGH PRESSURE WILL PASS NORTH OF THE AREA THURSDAY NIGHT...WITH A WEAK WARM FRONT LIFTING NORTHWARD ON FRIDAY. A STRONG COLD FRONT WILL THEN APPROACH FROM THE WEST FRIDAY NIGHT AND MOVE ACROSS THE AREA ON SATURDAY. HIGH PRESSURE THEN BUILDS OVER THE REGION LATE IN THE WEEKEND INTO EARLY NEXT WEEK. AS FOR EXPECTED WEATHER...THERE IS A SLIGHT CHANCE OF SHOWERS FRIDAY AND FRIDAY NIGHT AS THE WARM FRONT LIFTS THROUGH AND MOISTURE INCREASES WITHIN A DEVELOPING SOUTHWEST FLOW. A SOLID CHANCE OF SHOWERS AND THUNDERSTORMS IS THEN EXPECTED SATURDAY INTO SATURDAY NIGHT WITH THE FRONT ITSELF...BEFORE DRIER CONDITIONS RETURN BY SUNDAY AS HIGH PRESSURE BUILDS IN. IT SHOULD BE NOTED THAT LOW LEVEL WIND FIELDS AHEAD OF THE FRONT APPEAR VERY IMPRESSIVE. IF THE ATMOSPHERE CAN DESTABILIZE ENOUGH AHEAD OF THE FRONT...THEN THERE IS CERTAINLY A POTENTIAL FOR SEVERE WEATHER ACROSS THE AREA. IN ADDITION...BREEZY OR WINDY CONDITIONS ARE EXPECTED ON SATURDAY EVEN OUTSIDE OF CONVECTION DUE TO THE STRONG LOW LEVEL WIND FIELDS AND AGAIN ON SUNDAY WITH STRONG COLD AIR ADVECTION IN WAKE OF THE FRONT. TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THROUGH THE FIRST PART OF THE WEEKEND...BEFORE RETURNING CLOSER TO NORMAL LATE IN THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... HIGH PRESSURE WITH VFR CONDITIONS EXPECTED FOR THE PERIOD. EXTENDED AVIATION OUTLOOK... RISK FOR LOW-LEVEL WIND SHEAR AND MVFR OR LOWER CONDITIONS WEDNESDAY NIGHT AHEAD OF A COLD FRONT WITH A POTENTIAL FOR TSTMS AS WELL. VFR SHOULD THEN PREVAIL THROUGH FRIDAY. MVFR OR LOWER CIGS/VSBYS POSSIBLE ON SATURDAY IN SCATTERED SHOWERS/TSTORMS. && .MARINE... A COLD FRONT WILL MOVE OFFSHORE THIS MORNING...TURNING WINDS TO THE NE BY AROUND DAYBREAK. A MODEST COLD SURGE WILL KICK WINDS UP TO AROUND 15 KTS OR SO INTO THE EARLY EVENING HOURS AS HIGH PRESSURE BUILDS OVER THE WATERS. SEAS WILL INCREASE MAINLY INTO THE 3 TO 4 FT RANGE...WITH SOME 5 FOOTERS POSSIBLE OVER THE OUTER FRINGES OF OUR WATERS. WINDS WILL ABATE TO 10 KTS OR LESS OVERNIGHT AS HIGH PRESSURE CONTINUES TO BUILD IN...WITH SEAS CONTINUING IN THE 3 TO 4 FT RANGE. SOUTHWEST WINDS WILL INCREASE LATE WEDNESDAY AND WEDNESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT...WITH WINDS AND WAVES NEARING SMALL CRAFT ADVISORY LEVELS...BUT FORECAST TO REMAIN JUST BELOW CRITERIA AT THIS TIME. THE FRONT WILL PUSH OFFSHORE EARLY THURSDAY WITH WINDS/SEAS EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH FRIDAY. VERY STRONG LOW LEVEL WIND FIELDS AHEAD OF A POTENT COLD FRONT EXPECTED TO MOVE THROUGH ON SATURDAY WILL LIKELY RESULT IN SMALL CRAFT ADVISORY CONDITIONS ACROSS MOST OF THE WATERS FRIDAY NIGHT AND SATURDAY. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
920 AM EST TUE FEB 28 2012 .SYNOPSIS... HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE NORTH TODAY. A WARM FRONT SOUTH OF THE FORECAST AREA WILL LIFT NORTH OF THE AREA WEDNESDAY AHEAD OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL MOVE INTO THE FORECAST AREA WEDNESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... HAVE EXTENDED DENSE FOG ADVISORY UNTIL 10 AM THIS MORNING FOR MUCH OF THE AREA. STILL EXPECT OVERALL IMPROVEMENT IN VSBYS BY 10 AM. LINGERING LOW- LEVEL MOISTURE WITH DRYING ALOFT HAS HELPED CAUSE DENSE FOG EARLY THIS MORNING. THE LATEST RUC AND PRESSURE RISES OCCURRING NORTH OF THE AREA SUPPORT AN INCREASE IN BOUNDARY LAYER WINDS LATER THIS MORNING. THE DRY RIDGING SHOULD THEN BE DOMINATE DURING MUCH OF TODAY EXCEPT THE MODELS INDICATE ISENTROPIC LIFT LATER IN DAY NORTH OF A DEVELOPING WARM FRONT. EXPECT AN INCREASE IN CLOUDINESS MAINLY IN THE SOUTH PART. THE NAM MOS INDICATES RAIN MAY DEVELOP IN THE CENTRAL SAVANNAH RIVER AREA THIS AFTERNOON. THE LIFT APPEARS WEAK SO USED THE GFS MOS AND SREF GUIDANCE AND KEPT THE DRY FORECAST FOR THE ENTIRE AREA TODAY. THE TEMPERATURE GUIDANCE WAS CONSISTENT. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... CONTINUED ISENTROPIC LIFT NORTH OF THE WARM FRONT SUPPORTS POSSIBLE RAIN TONIGHT. THE MODELS KEPT THE LIFT WEAK WITH A FLAT UPPER-LEVEL PATTERN. THE NAM AND GFS MOS SUPPORT SLIGHT CHANCE OR CHANCE POPS. THE NAM LI PATTERN SUGGEST THE WARM FRONT WILL LIFT NORTH OF THE FORECAST AREA WEDNESDAY. USED THE GFS AND NAM MOS AND FORECASTED A SMALL CHANCE OF SHOWERS BECAUSE OF WEAK ISENTROPIC LIFT AND CONVERGENCE NEAR THE WARM FRONT. THE CHANCE APPEARS LIMITED BECAUSE OF THE WEAK LIFT...SHALLOW MOISTURE...AND A FLAT UPPER-LEVEL PATTERN. THE NAM AND GFS SHOW A WEAKENING COLD FRONT APPROACHING THE FORECAST AREA WEDNESDAY NIGHT. CHANCE POPS AS INDICATED BY THE GFS AND NAM MOS APPEARS REASONABLE BECAUSE OF DIMINISHING CONVERGENCE ASSOCIATED WITH THE WEAKENING FRONT AND LITTLE UPPER-LEVEL LIFT. DESPITE THE WEAKENING CONVERGENCE THE NAM AND GFS ARE IN GOOD AGREEMENT SHOWING HIGH SHEAR WITH H85 WINDS OF 40 TO 50 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S OF -1 TO -3. THIS COMBINATION OF SHEAR AND INSTABILITY SUPPORTS POSSIBLE SEVERE WIND GUSTS AND WE HAVE NOTED THE THREAT IN THE HAZARDOUS WEATHER OUTLOOK. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURES EXCEPT THE WARMER VALUES APPEAR BETTER WEDNESDAY NIGHT BECAUSE OF CLOUDINESS AND MIXING AHEAD OF THE FRONT. && .LONG TERM /THURSDAY THROUGH MONDAY/... THE GFS SHOWS THE FRONT STALLING AND BECOMING DIFFUSE IN THE FORECAST AREA THURSDAY. DEEPER MOISTURE APPEARS TO SHIFT SOUTH AND EAST OF THE AREA. THE FRONT APPEARS TO BECOME A WARM FRONT FRIDAY WITH AN INCREASE IN MOISTURE. THIS WARM FRONT SHOULD LIFT NORTH OF THE FORECAST AREA AHEAD OF THE NEXT COLD FRONT. THE GFS AND ECMWF SHOW THIS COLD FRONT IN THE FORECAST AREA SATURDAY. STRONG SHEAR AND SOME INSTABILITY WILL LIKELY BE ASSOCIATED WITH THIS FRONT SUPPORTING A THREAT OF SEVERE THUNDERSTORMS. DRYING BEHIND THE FRONT SHOULD DOMINATE SUNDAY AND MONDAY. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... VSBYS BEGINNING TO SLOWLY IMPROVE OVER THE AREA...SLOWLY BECOMING IFR. VSBYS SHOULD CONTINUE TO SLOWLY IMPROVE THROUGH 15Z-16Z. WINDS WILL BE PICKING UP OUT OF THE NORTHEAST AROUND 10 MPH AFTER 15Z. HIGH CLOUDS WILL BLANKET THE AREA BY LATE AFTERNOON AND LOWER VFR CIGS WILL RETURN AFTER 00Z ASSOCIATED WITH WARM ADVECTION AHEAD OF THE NEXT WEATHER SYSTEM. INCREASING CONFIDENCE IN MVFR CIGS AFTER 06Z WITH POSSIBLE IFR CONDITIONS 09Z-12Z. EXTENDED AVIATION OUTLOOK...IFR/MVFR CONDITIONS POSSIBLE WED/WED NT INTO EARLY THU...EARLY FRI...AND AGAIN SAT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
630 AM EST TUE FEB 28 2012 .SYNOPSIS... HIGH PRESSURE WILL RIDGE INTO THE FORECAST AREA FROM THE NORTH TODAY. A WARM FRONT SOUTH OF THE FORECAST AREA WILL LIFT NORTH OF THE AREA WEDNESDAY AHEAD OF AN APPROACHING COLD FRONT. THE COLD FRONT WILL MOVE INTO THE FORECAST AREA WEDNESDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LINGERING LOW-LEVEL MOISTURE WITH DRYING ALOFT HAS HELPED CAUSE DENSE FOG EARLY THIS MORNING. THE LATEST RUC AND PRESSURE RISES OCCURRING NORTH OF THE AREA SUPPORT AN INCREASE IN BOUNDARY LAYER WINDS LATER THIS MORNING. EXPECT IMPROVEMENT WILL OCCUR BEFORE 1000 AM THIS MORNING. THE DRY RIDGING SHOULD THEN BE DOMINATE DURING MUCH OF TODAY EXCEPT THE MODELS INDICATE ISENTROPIC LIFT LATER IN DAY NORTH OF A DEVELOPING WARM FRONT. EXPECT AN INCREASE IN CLOUDINESS MAINLY IN THE SOUTH PART. THE NAM MOS INDICATES RAIN MAY DEVELOP IN THE CENTRAL SAVANNAH RIVER AREA THIS AFTERNOON. THE LIFT APPEARS WEAK SO USED THE GFS MOS AND SREF GUIDANCE AND KEPT THE DRY FORECAST FOR THE ENTIRE AREA TODAY. THE TEMPERATURE GUIDANCE WAS CONSISTENT. && .SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... CONTINUED ISENTROPIC LIFT NORTH OF THE WARM FRONT SUPPORTS POSSIBLE RAIN TONIGHT. THE MODELS KEPT THE LIFT WEAK WITH A FLAT UPPER-LEVEL PATTERN. THE NAM AND GFS MOS SUPPORT SLIGHT CHANCE OR CHANCE POPS. THE NAM LI PATTERN SUGGEST THE WARM FRONT WILL LIFT NORTH OF THE FORECAST AREA WEDNESDAY. USED THE GFS AND NAM MOS AND FORECASTED A SMALL CHANCE OF SHOWERS BECAUSE OF WEAK ISENTROPIC LIFT AND CONVERGENCE NEAR THE WARM FRONT. THE CHANCE APPEARS LIMITED BECAUSE OF THE WEAK LIFT...SHALLOW MOISTURE...AND A FLAT UPPER-LEVEL PATTERN. THE NAM AND GFS SHOW A WEAKENING COLD FRONT APPROACHING THE FORECAST AREA WEDNESDAY NIGHT. CHANCE POPS AS INDICATED BY THE GFS AND NAM MOS APPEARS REASONABLE BECAUSE OF DIMINISHING CONVERGENCE ASSOCIATED WITH THE WEAKENING FRONT AND LITTLE UPPER-LEVEL LIFT. DESPITE THE WEAKENING CONVERGENCE THE NAM AND GFS ARE IN GOOD AGREEMENT SHOWING HIGH SHEAR WITH H85 WINDS OF 40 TO 50 KNOTS. THE NAM INDICATES SURFACE-BASED LI/S OF -1 TO -3. THIS COMBINATION OF SHEAR AND INSTABILITY SUPPORTS POSSIBLE SEVERE WIND GUSTS AND WE HAVE NOTED THE THREAT IN THE HAZARDOUS WEATHER OUTLOOK. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURES EXCEPT THE WARMER VALUES APPEAR BETTER WEDNESDAY NIGHT BECAUSE OF CLOUDINESS AND MIXING AHEAD OF THE FRONT. && .LONG TERM /THURSDAY THROUGH MONDAY/... THE GFS SHOWS THE FRONT STALLING AND BECOMING DIFFUSE IN THE FORECAST AREA THURSDAY. DEEPER MOISTURE APPEARS TO SHIFT SOUTH AND EAST OF THE AREA. THE FRONT APPEARS TO BECOME A WARM FRONT FRIDAY WITH AN INCREASE IN MOISTURE. THIS WARM FRONT SHOULD LIFT NORTH OF THE FORECAST AREA AHEAD OF THE NEXT COLD FRONT. THE GFS AND ECMWF SHOW THIS COLD FRONT IN THE FORECAST AREA SATURDAY. STRONG SHEAR AND SOME INSTABILITY WILL LIKELY BE ASSOCIATED WITH THIS FRONT SUPPORTING A THREAT OF SEVERE THUNDERSTORMS. DRYING BEHIND THE FRONT SHOULD DOMINATE SUNDAY AND MONDAY. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... WIDESPREAD LIFR CONDITIONS AREAWIDE IN DENSE FOG. EXPECT LIFR CONDITIONS TO PERSIST THROUGH 14Z-15Z BEFORE FOG LIFTS AND CIGS/VSBYS RETURN TO VFR BY 16Z. WINDS WILL BE PICKING UP OUT OF THE NORTHEAST AROUND 10 MPH AFTER 15Z. HIGH CLOUDS WILL BLANKET THE AREA BY LATE AFTERNOON AND LOWER VFR CIGS WILL RETURN AFTER 00Z ASSOCIATED WITH WARM ADVECTION AHEAD OF THE NEXT WEATHER SYSTEM. INCREASING CONFIDENCE IN MVFR CIGS AFTER 06Z WITH POSSIBLE IFR CONDITIONS 09Z-12Z. EXTENDED AVIATION OUTLOOK...IFR/MVFR CONDITIONS POSSIBLE WED/WED NT INTO EARLY THU...EARLY FRI...AND AGAIN SAT. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ015-016- 018-020>022-025>031-035>038-041. GA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR GAZ040- 063>065-077. && $$ SYNOPSIS...JL NEAR TERM...JL SHORT TERM...JL LONG TERM...JL AVIATION...HC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
310 AM MST TUE FEB 28 2012 .SHORT TERM...VALID FOR TDY AND WED... CLOUD TOPS COOLING RAPIDLY IN SE ID AND WY IN RESPONSE TO ENERGETIC TROF BEGINNING TO LIFT OUT OF THE SOUTHERN ROCKIES. RADAR MOSAIC/SFC OBS INDICATE PCPN THROUGH RIW AND CPR...AND WITHIN A FEW HOURS OF SHERIDAN. SATELLITE IMAGERY SHOWS STRONGLY DIFFLUENT SIGNATURE IN UT/CO PER 100+KT JET. ALSO OF NOTE IS WEAK 700MB LOW IN SE ID WHICH IS PRODUCING PCPN FROM PIH TO IDA AND NEARLY WEY...AND WHICH WILL IMPACT OUR WEST LATER THIS MORNING. SHERIDAN COUNTY AND OUR FAR SOUTHEAST WILL BE STRONGEST HIT IN OUR AREA WITH THIS UPCOMING SYSTEM. FORCING/UPSLOPE FLOW WILL YIELD SOME MODERATE TO HEAVY SNOWFALL ALONG THE EAST SLOPES OF THE BIG HORN MOUNTAINS TODAY. AS LOW DEEPENS TO OUR EAST...LOCATION OF HEAVIER PCPN WILL SHIFT EAST OVER TIME AND IMPACT OUR FAR EAST TONIGHT. SREF PLUMES/MIXING RATIOS AND EVEN MODEL QPF ARE ALL IN PRETTY GOOD AGREEMENT IN SHOWING A GENERAL 3-6 INCH SNOWFALL FROM SHERIDAN COUNTY TO POWDER RIVER AND CARTER COUNTIES TODAY AND TONIGHT...AND HAVE ISSUED ADVISORIES FOR THESE AREAS. I-90 TRAVEL IN SHERIDAN COUNTY WILL CERTAINLY BE IMPACTED BEGINNING EARLY THIS MORNING...AS WILL HIGHWAY 212 FROM BROADUS TO ALZADA. AMOUNTS WILL TAPER TO THE NW WITH MAINLY 1-3 AMOUNTS FROM SOUTHERN BIG HORN...SOUTHERN ROSEBUD...SOUTHERN CUSTER AND FALLON COUNTIES. WITHOUT ANY ADDITIONAL IMPACTS OTHER THAN DAYTIME SNOWFALL WILL LEAVE THESE AREAS WITHOUT A HIGHLIGHT. IF LOW SLOWS A BIT THE HIGHER TERRAIN IN THESE AREAS COULD SEE A BIT MORE SNOW...AND WILL NEED TO WATCH THIS. LATEST RUC ANALYSIS ALONG WITH RAPIDLY COOLING TOPS IN SE ID SEEM TO INDICATE SOME UPSLOPE SNOW WILL DEVELOP ALONG THE FOOTHILLS OF THE BEARTOOTH ABSAROKAS THIS MORNING...AS DEEPENING EAST FLOW IS BEGINNING TO MOISTEN UP ALREADY AS OF 10Z. HAVE RAISED POPS IN THESE AREAS AND GIVEN THE NYE AND RED LODGE AREAS A COUPLE INCHES OF SNOW...BEFORE DOWNSLOPING TAKES OVER LATE THIS AFTERNOON. SHOULD EVEN SEE SOME LIGHT SNOW IN LIVINGSTON PER THE EAST WINDS. AS FOR BILLINGS...THE ASCENT WILL BE ENOUGH TO PRODUCE SOME LIGHT SNOW BEGINNING AROUND 18Z...BUT THE QUESTION IS WHETHER THE LOW LEVELS WILL MOISTEN UP ENOUGH AS NE FLOW WILL PROVIDE A FEED OF DRIER BOUNDARY LAYER AIR. WILL FLIP A COIN AND GIVE BILLINGS A 50 POP TODAY. IF IT HAPPENS...THE BETTER CHANCE WILL BE THIS AFTERNOON INTO PERHAPS THE EARLY EVENING...AND AMOUNTS SHOULD BE A HALF INCH OR LESS. SYSTEM WILL EXIT TO OUR EAST BY 12Z WEDNESDAY. DOWNSLOPE GRADIENTS ACTUALLY TIGHTEN UP AFTER 06Z TONIGHT IN OUR WEST...SO EXPECT SOME GUSTY SW WINDS TO DEVELOP AT LIVINGSTON AND NYE AFTER MIDNIGHT. WEDNESDAY WILL BE WARMER ACROSS THE AREA PER THE DOWNSLOPING AND SHOULD SEE HIGHS INTO THE 40S EXPECT FOR OUR FAR EAST AND WHERE FRESH SNOW COVER WILL BE. NEXT PACIFIC TROF IS MOVING IN RAPIDLY THOUGH. EXPECT A GOOD DOSE OF SNOW FOR OUR WESTERN SLOPES WEDNESDAY INTO WEDNESDAY EVENING AS THE AIRMASS TURNS FAIRLY UNSTABLE PER VERY COLD MID LEVEL TEMPS. ISOLATED TO SCATTERED RAIN TO SNOW SHOWERS WILL IMPACT OUR LOWER ELEVATIONS. WOULD NOT BE SURPRISED IF THERE WERE A FEW LIGHTNING STRIKES AS MODELS SHOW A BIT OF CAPE IN OUR WEST AROUND 00Z LATE WEDNESDAY AFTERNOON. JKL .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... BROAD CYCLONIC FLOW WILL BE OVER THE AREA ON THURSDAY WITH A SPLITTING TR0UGH MOVING ACROSS MONTANA. THE STRONGEST ENERGY WILL STAY IN THE NORTHERN BRANCH AND WILL BRING SCATTERED SNOW SHOWERS TO THE FORECAST AREA. BEST LIFT AND Q VECTOR FORCING WILL BE OVER OUR SOUTHWEST MOUNTAINS AND HAVE RAISED POPS TO CATEGORICAL FOR THE COOKE CITY AREA WITH SNOW AMOUNTS OF 4 TO 6 INCHES EXPECTED. THIS IS WILL BE A QUICK MOVING SYSTEM AND AMOUNTS WILL STAY BELOW WARNING CRITERIA FOR THE MOUNTAINS. SNOW AMOUNTS OVER THE PLAINS WILL BE LESS THAN A INCH. UPPER FLOW WILL QUICKLY TRANSITION TO AN UNSTABLE NORTHWEST FLOW FRIDAY AND SATURDAY. CONTINUED A SLIGHT CHANCE OF RAIN AND SNOW SHOWERS THROUGH THIS TIME PERIOD. UPPER RIDGE OF HIGH PRESSURE WILL BEGIN TO BUILD OVER THE REGION SUNDAY NIGHT INTO MONDAY. THIS WILL BRING DRY WEATHER AND WARMER TEMPERATURES. SHOULD SEE UPPER 40S MONDAY WITH LOW 50S SUNDAY FOR AFTERNOON HIGH TEMPERATURES. ANOTHER TROUGH OF LOW PRESSURE TO PUSH ACROSS THE AREA MONDAY NIGHT INTO TUESDAY. LOW AND MID LEVEL MOISTURE LOOKS LIMITED AT THIS TIME AND HAVE GONE WITH ONLY ISOLATED POPS. SURFACE PATTERN SETTING UP FOR POSSIBLE GUSTY WINDS IN THE GAP FLOW AREAS FRIDAY NIGHT AND SATURDAY. 700 MB WINDS INCREASING TO 60 KTS OVER OUR WESTERN ZONES. THESE STRONG MID LEVEL WINDS WILL SHIFT OUT INTO THE PLAINS SATURDAY AND THIS WILL TRANSLATE TO GUSTY WINDS FROM BILLINGS TO HARLOWTON. RICHMOND && .AVIATION... PATCHY FOG CAN BE EXPECTED EAST OF KBIL THROUGH MID MORNING. A STRONG STORM SYSTEM WILL MOVE INTO THE CENTRAL PLAINS TODAY AND WILL SPREAD SNOW NORTHWARD. THE HEAVIEST SNOW IS EXPECTED FROM KSHR NORTHEAST THROUGH EKALAKA. IFR/LIFR CONDITIONS CAN BE EXPECTED. SNOW WILL SPREAD INTO KLVM TO KBIL BY 18Z AND WILL BRING OCCASIONAL MVFR TO IFR CONDITIONS. SNOW SHOWERS WILL BE HEAVY OVER THE MOUNTAINS AND TOTAL OBSCURATIONS WILL BE ENCOUNTERED. CONDITIONS WILL IMPROVE TONIGHT AS THE STORM SYSTEM MOVES AWAY FROM THE REGION. RICHMOND && .PRELIMINARY POINT TEMP/POPS... TDY WED THU FRI SAT SUN MON ------------------------------------------------------- BIL 031 021/045 025/038 020/038 025/043 030/049 029/051 5/S 31/N 24/J 22/J 22/W 20/N 01/B LVM 033 023/040 021/033 014/034 017/037 025/044 025/045 6/S 13/W 45/J 32/J 22/J 21/N 11/N HDN 028 013/043 024/039 021/038 023/043 028/049 026/051 6/S 41/B 23/J 22/J 22/W 20/B 01/B MLS 026 012/040 022/037 020/034 021/040 027/045 027/050 3/S 30/B 22/J 22/J 22/J 20/B 01/B 4BQ 024 013/040 020/036 017/033 019/038 025/046 024/049 +/S 91/B 22/J 22/J 22/J 20/B 01/B BHK 022 010/033 017/034 016/026 013/035 021/042 023/046 6/S 81/B 22/J 22/J 11/B 21/B 01/B SHR 027 013/041 022/035 014/034 016/037 023/046 023/049 +/S 60/U 23/J 32/J 22/J 21/B 12/J && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MST WEDNESDAY FOR ZONES 36-37. WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MST TONIGHT FOR ZONES 98-99. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
430 AM CST TUE FEB 28 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY AFTERNOON... FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL FOCUS ON THE IMPENDING STORM SET TO BRING SEVERE WINTER WEATHER TO MUCH OF THE LOCAL REGION LATER TODAY...THROUGH TONIGHT...AND INTO WEDNESDAY. THE 00Z GFS/ECMWF/GEM HAVE TRENDED TOWARDS A CONSENSUS...AND LEANED HEAVILY ON A BLEND OF THEIR OUTPUT. CURRENTLY...LOW LEVEL STRATUS BLOB...NOW OVER SOUTHWEST...WEST CENTRAL...AND PORTIONS OF NORTH CENTRAL ND...CONTINUES TO EXPAND SLIGHTLY NORTH AND NOW IS INCREASING ITS EXPANSION EAST INTO MY CENTRAL COUNTIES. WHILE THE NORTHWARD TREND IS EXPECTED TO SLOW DOWN...THE EASTWARD EXPANSION OF THE STRATUS IS EXPECTED TO CONTINUE THIS MORNING WITH AN INCREASING UPSLOPE FLOW COMPONENT OVER SOUTH CENTRAL ND. AREAS OF FOG DEVELOPED WEST AS SFC WINDS WENT CALM AND THANKS TO AN EAST/NORTHEASTERLY UPSLOPE LOW LEVEL FLOW REGIME. WILL MAINTAIN AREAS OF FOG THROUGH 18Z WEST AND CENTRAL AND PATCHY FOG EAST. THE 00Z GFS/GEM/ECMWF HAVE ONCE AGAIN TRENDED SLOWER WITH THE ONSET OF PRECIPITATION TODAY. WILL MAINTAIN THE EDITS MADE FOR THE EARLY MORNING UPDATE. BASICALLY WE HAVE SLIGHT CHANCES FAR SOUTH ALONG THE BORDER COUNTIES OF SOUTH DAKOTA 12-18Z THIS MORNING. UPPER LEVEL TROUGH WILL CONTINUE TO LIFT NORTHEAST ACROSS THE CENTRAL ROCKIES THIS MORNING...THEN CLOSES OFF AND BECOMES NEGATIVELY TILTED THIS AFTERNOON OVER WESTERN NB/WESTERN SD. AS THIS OCCURS LEE SIDE CYCLOGENESIS RAMPS UP 12-18Z...WITH A COLORADO LOW DEVELOPING AND LIFTING NORTHEAST ACROSS CENTRAL NEBRASKA THIS AFTERNOON. LARGE SCALE ASCENT INCREASES ACROSS SOUTHERN NORTH DAKOTA AFTER 18Z AHEAD OF THE UPPER LOW ALONG WITH INCREASING THERMAL LIFT AS THE SYSTEMS WARM CONVEYOR BELT/TROWAL DEVELOPS AND WRAPS BACK WESTWARD ACROSS SOUTH DAKOTA AND ACROSS MY SOUTHERN COUNTIES. WITH MODELS SLOWING THINGS DOWN...FORCING NOW EXPANDS FARTHER NORTHWARD THIS EVENING AND OVERNIGHT INTO WEDNESDAY MORNING THAN WHAT MODELS HAD PREVIOUSLY ADVERTISED. THE TROWAL AXIS AND DEFORMATION ZONE...ADVERTISED BY THE GFS AND ECMWF...WILL BE COLOCATED AND IN A FAVORABLE POSITION TO BRING HEAVY WRAP AROUND SNOW ACROSS MUCH OF CENTRAL AND EASTERN NORTH DAKOTA THROUGH TONIGHT...WINDING DOWN GRADUALLY 12-18Z WED CENTRAL BUT STILL STRONG EAST. PRECIPITATION REALLY STARTS TO WIND DOWN FROM WEST TO EAST WEDNESDAY AFTERNOON AS THE UPPER LOW MOVES INTO THE GREAT LAKES REGION. WITH THE SLOW DOWN AND FARTHER NORTH TRACK...STORM TOTAL SNOW NOW RANGES FROM 8-12 INCHES OVER ALMOST THE ENTIRE WARNED AREA (WINTER STORM AND BLIZZARD). COULD VERY POSSIBLY SEE SNOW TOTALS IN EXCESS OF A FOOT WITH ELEVATED INSTABILITY PRESENT ACROSS MY SOUTH CENTRAL AND SOUTHEAST (ADVERTISED BY THE HRRR MODEL AND BUFKIT SOUNDINGS). IN ADDITION TO THE HEAVY SNOW...BUFFER DATA CONTINUES TO INDICATE WIND GUSTS IN EXCESS OF 30 KTS (GREATER THAN 35 MPH) TONIGHT OVER THE BLIZZARD WARNING AREA (FAR SOUTH CENTRAL AND ACROSS MUCH OF THE JAMES RIVER BASIN) ONCE THE STORM LIFTS INTO EASTERN SD AND EVENTUALLY INTO SOUTHERN MN. FREQUENT WIND GUSTS GREATER THAN 35 MPH AND VIS OF 1/4 MILE IS BLIZZARD WARNING CRITERIA. WILL HAVE NO PROBLEM SEEING VISIBILITIES OF 1/4 MILE AND LESS. WE BELIEVE MODELS ARE UNDERESTIMATING THE WIND MAGNITUDES GIVEN THE PRESSURE GRADIENT DEPICTED AND BASED ON THE GEOSTROPHIC SFC WINDS ADVERTISED. THUS BUMPED THE MODEL OUTPUT WINDS UP SLIGHTLY. THE HEADLINES INHERITED FROM MONDAYS DAYSHIFT ARE SPOT ON AND WILL MAKE NO CHANGES WITH THIS MORNINGS FORECAST PACKAGE. WE WILL NEED TO MONITOR THE 12Z MODEL TRENDS CLOSELY FOR A) POSSIBLE EXPANSION OF THE WINTER STORM WARNING (NORTHWARD INTO THE NORTH CENTRAL AND B) POSSIBLY UPGRADING PORTIONS OF THE WINTER STORM WARNING TO A BLIZZARD WARNING. .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... THE WINTER STORM SYSTEM SHOULD BE EXITING THE REGION TO THE EAST WEDNESDAY NIGHT...BUT MODELS ARE ALREADY DEPICTING A BROAD LONGWAVE TROUGH DEVELOPING AND MOVING ACROSS THE ROCKIES BY THURSDAY. THIS TROUGH WILL AFFECT THE AREA THURSDAY AND FRIDAY. COOL CYCLONIC FLOW ALOFT WILL SUPPORT A CHANCE OF SNOW...WITH THE FOCUS ON THE THURSDAY TIME PERIOD. AN INCH OR TWO OF SNOW IS POSSIBLE DURING THIS TIME. FOLLOWING THIS UPPER TROUGH...THE MODELS INDICATE RIDGING BUILDING ACROSS THE ROCKIES FOR THE WEEKEND. THERE IS A HINT THAT A FAST-MOVING SHORTWAVE IN THE UPPER FLOW MAY MOVE ACROSS SOUTH CENTRAL CANADA AND THE NORTHERN TIER OF THE US ON MONDAY. KEPT A SLIGHT CHANCE OF LIGHT RAIN/SNOW IN NORTHERN COUNTIES MONDAY. TEMPERATURES SHOULD BE ON THE COOL SIDE THROUGH THE END OF THE WEEK WITH THE UPPER LEVEL OVER THE REGION. EXPECT LOWS IN THE SINGLE DIGITS TO TEENS...AND HIGHS IN THE 20S TO LOWER 30S. BUT SIGNIFICANT WARMING IS INDICATED WITH THE BROAD H500 RIDGE INTO THE WEEKEND AND EARLY NEXT WEEK. HIGHS MAINLY IN THE 30S TO AROUND 40 SUNDAY...AND MID 30S TO LOWER 40S MONDAY. && .AVIATION...AT 3 AM CST...DEVELOPING LOW PRESSURE OVER COLORADO AND THE ASSOCIATED SOUTHERLY WINDS AHEAD OF THE LOW WERE BRINGING LOW LEVEL MOISTURE AND CLOUDS INTO WESTERN AND CENTRAL NORTH DAKOTA. IFR/LOW IFR CEILINGS HAVE DEVELOPED AT KDIK AND WILL CONTINUE THROUGH THE TAF PERIOD. MVFR CIGS WILL DEVELOP OVER KBIS/KMOT BY 12Z/6 AM CST. MVFR TO IFR CIGS EXPECTED AT KJMS AFTER 15Z. THEN THE DEVELOPING WINTER STORM OVER COLORADO WILL MOVE NORTHEAST BRINGING IFR CIGS AND VSBYS IN SNOW ACROSS SOUTHERN AND CENTRAL NORTH DAKOTA AFTER 00Z...AT KBIS/KDIK/KJMS. MVFR AT KISN/KMOT AFTER 00Z. && .BIS WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 3 PM CST /2 PM MST/ THIS AFTERNOON TO 6 PM CST /5 PM MST/ WEDNESDAY FOR NDZ012-013-018-019-021- 031>033-040-043. BLIZZARD WARNING FROM 3 PM THIS AFTERNOON TO 6 PM CST WEDNESDAY FOR NDZ037-045>048-050-051. WINTER STORM WARNING FROM 3 PM CST /2 PM MST/ THIS AFTERNOON TO 6 PM CST /5 PM MST/ WEDNESDAY FOR NDZ020-022-023-025-034>036-041- 042-044. && $$ SHORT TERM...NH LONG TERM....WAA AVIATION...WAA
AREA FORECAST DISCUSSION
NWS NORMAN OK
550 AM CST TUE FEB 28 2012 .AVIATION... CEILINGS SHOULD SLOWLY LOWER THIS MORNING WITH BETTER MOISTURE RETURN...SIMILAR TO CEILING HEIGHTS ACROSS NORTH TEXAS AT 12Z. WEAK UPGLIDE MAY RESULT IN WIDELY SCATTERED LIGHT SHOWERS THROUGH ROUGH 18-19Z. SOME IMPROVEMENT IN CEILINGS SHOULD OCCUR ACROSS WESTERN OKLAHOMA DURING THE EARLY TO MID AFTERNOON WITH LOW MVFR CEILINGS ACROSS CENTRAL OKLAHOMA. VERY STRONG WINDS WILL DEVELOP NEAR GAG/WWR SITES AS DRYLINE PUSHES THROUGH BY LATE AFTERNOON. BEST OPPORTUNITY FOR TSRA ALONG I-35 WILL BE FROM 00-03Z. && .PREV DISCUSSION... /ISSUED 406 AM CST TUE FEB 28 2012/ DISCUSSION... MOISTURE AND MODEST THERMAL ADVECTION THIS MORNING INTO THE AFTERNOON SHOULD RESULT IN WIDELY SCATTERED LIGHT RAIN SHOWERS WITH PERHAPS BETTER COVERAGE OUT WEST EARLY THIS MORNING. 00Z NSSL WRF AND HRRR SIMILAR WITH BETTER CHANCES FOR PRECIP EARLY THIS AFTERNOON LIFTING NORTH AND EAST OF FA. BY MID TO LATE AFTERNOON...A DRYLINE WILL MIX INTO FAR WESTERN OKLAHOMA AND THE ADJACENT AREA OF WESTERN NORTH TEXAS. DEEP MIXING BEHIND THE DRYLINE SHOULD CREATE MODERATE TO HIGH END RED FLAG CONDITIONS...ESPECIALLY ACROSS NORTHWEST OKLAHOMA. NEAR/JUST ABOVE SEVERE WIND GUSTS MAY OCCUR FOR A FEW HOURS LATE THIS AFTERNOON ACROSS FAR NORTHWEST OKLAHOMA. CONSIDERED A HIGH WIND WARNING FOR 3 OR 4 COUNTIES BUT FOR NOW WILL KEEP THIS AREA IN A WIND ADVISORY. STORM CHANCES WITH THIS SYSTEM APPEAR TO BE LIMITED...AT LEAST IN COVERAGE. THE NSSL WRF ATTEMPTS INITIATION NEAR THE DRYLINE LATE IN THE AFTERNOON WITH PERHAPS A BETTER CHANCE ACROSS EASTERN PARTS OF THE FA DURING THE EARLY TO MID EVENING. ANY STORM THAT CAN REALIZE BETTER INSTABILITY...WILL POSE A RISK OF PRODUCING DAMAGING WINDS AND LARGE HAIL. ANOTHER TROUGH/SYSTEM WILL IMPACT THE SOUTHERN PLAINS THURSDAY INTO FRIDAY. ALTHOUGH TEMPERATURES WILL BE RATHER WARM THURSDAY WITH INCREASING WINDS...HUMIDITY LEVELS MAY REMAIN HIGH ENOUGH MOST AREAS TO ALLEVIATE FIRE WEATHER CONCERNS. THIS SYSTEM WILL PUSH A COLD FRONT ACROSS THE AREA LATE THURSDAY INTO FRIDAY. THE BEST OPPORTUNITY FOR STORMS WILL BE ACROSS SOUTHEAST OKLAHOMA. THIS SYSTEM WILL BRING SOME COOLER AIR FOR THE FIRST PART OF THE WEEKEND BUT TEMPERATURES WILL WARM AGAIN GOING INTO EARLY NEXT WEEK. ANOTHER SYSTEM MAY HELP INCREASE RAIN/STORM CHANCES NEXT TUESDAY INTO WEDNESDAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 68 39 70 38 / 50 20 0 0 HOBART OK 70 38 68 36 / 50 10 0 0 WICHITA FALLS TX 77 42 74 40 / 30 20 0 10 GAGE OK 71 33 66 30 / 50 10 0 0 PONCA CITY OK 69 37 66 38 / 60 30 10 0 DURANT OK 68 51 73 44 / 30 40 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CST THIS EVENING FOR OKZ004>006-009>011-014>016-021-022-033>036. RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM CST THIS EVENING FOR OKZ004-005-009-010-014-021-033-034-036. TX...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CST THIS EVENING FOR TXZ083-084-087. RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM CST THIS EVENING FOR TXZ083-084-087. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
406 AM CST TUE FEB 28 2012 .DISCUSSION... MOISTURE AND MODEST THERMAL ADVECTION THIS MORNING INTO THE AFTERNOON SHOULD RESULT IN WIDELY SCATTERED LIGHT RAIN SHOWERS WITH PERHAPS BETTER COVERAGE OUT WEST EARLY THIS MORNING. 00Z NSSL WRF AND HRRR SIMILAR WITH BETTER CHANCES FOR PRECIP EARLY THIS AFTERNOON LIFTING NORTH AND EAST OF FA. BY MID TO LATE AFTERNOON...A DRYLINE WILL MIX INTO FAR WESTERN OKLAHOMA AND THE ADJACENT AREA OF WESTERN NORTH TEXAS. DEEP MIXING BEHIND THE DRYLINE SHOULD CREATE MODERATE TO HIGH END RED FLAG CONDITIONS...ESPECIALLY ACROSS NORTHWEST OKLAHOMA. NEAR/JUST ABOVE SEVERE WIND GUSTS MAY OCCUR FOR A FEW HOURS LATE THIS AFTERNOON ACROSS FAR NORTHWEST OKLAHOMA. CONSIDERED A HIGH WIND WARNING FOR 3 OR 4 COUNTIES BUT FOR NOW WILL KEEP THIS AREA IN A WIND ADVISORY. STORM CHANCES WITH THIS SYSTEM APPEAR TO BE LIMITED...AT LEAST IN COVERAGE. THE NSSL WRF ATTEMPTS INITIATION NEAR THE DRYLINE LATE IN THE AFTERNOON WITH PERHAPS A BETTER CHANCE ACROSS EASTERN PARTS OF THE FA DURING THE EARLY TO MID EVENING. ANY STORM THAT CAN REALIZE BETTER INSTABILITY...WILL POSE A RISK OF PRODUCING DAMAGING WINDS AND LARGE HAIL. ANOTHER TROUGH/SYSTEM WILL IMPACT THE SOUTHERN PLAINS THURSDAY INTO FRIDAY. ALTHOUGH TEMPERATURES WILL BE RATHER WARM THURSDAY WITH INCREASING WINDS...HUMIDITY LEVELS MAY REMAIN HIGH ENOUGH MOST AREAS TO ALLEVIATE FIRE WEATHER CONCERNS. THIS SYSTEM WILL PUSH A COLD FRONT ACROSS THE AREA LATE THURSDAY INTO FRIDAY. THE BEST OPPORTUNITY FOR STORMS WILL BE ACROSS SOUTHEAST OKLAHOMA. THIS SYSTEM WILL BRING SOME COOLER AIR FOR THE FIRST PART OF THE WEEKEND BUT TEMPERATURES WILL WARM AGAIN GOING INTO EARLY NEXT WEEK. ANOTHER SYSTEM MAY HELP INCREASE RAIN/STORM CHANCES NEXT TUESDAY INTO WEDNESDAY. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 68 39 70 38 / 50 20 0 0 HOBART OK 70 38 68 36 / 50 10 0 0 WICHITA FALLS TX 77 42 74 40 / 30 20 0 10 GAGE OK 71 33 66 30 / 50 10 0 0 PONCA CITY OK 69 37 66 38 / 60 30 10 0 DURANT OK 68 51 73 44 / 30 40 10 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CST THIS EVENING FOR OKZ004>006-009>011-014>016-021-022-033>036. RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM CST THIS EVENING FOR OKZ004-005-009-010-014-021-033-034-036. TX...WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CST THIS EVENING FOR TXZ083-084-087. RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 7 PM CST THIS EVENING FOR TXZ083-084-087. && $$ 01/01
AREA FORECAST DISCUSSION
NWS MIAMI FL
1250 PM EST TUE FEB 28 2012 .AVIATION... EAST COAST SEA BREEZE PUSHING INLAND IN PREVAILING EAST FLOW THIS AFTERNOON. THIS SHOULD KEEP SIGNIFICANT CONVECTION INLAND OF THE EAST COAST TERMINALS. AT KAPF...GULF SEA BREEZE SHOULD COMMENCE AROUND 19Z WITH BETTER CHANCE OF SHRA NEAR TERMINAL. FOR NOW WILL NOT INCLUDE TSRA ALTHOUGH THIS WILL HAVE TO BE CLOSELY WATCHED. OTHERWISE, PREVAILING VFR EXPECTED AT ALL SITES OVER THE ENTIRE FORECAST PERIOD. INCLUDED TEMPO 5SM BR AT KAPF DUE TO LIGHT EAST FLOW AND LEFTOVER MOISTURE FROM ANY AFTERNOON/EVENING PRECIP. /MOLLEDA && .PREV DISCUSSION... /ISSUED 1011 AM EST TUE FEB 28 2012/ UPDATE... LATEST SURFACE ANALYSIS SHOWS WEAK FRONTAL SYSTEM OFF THE MID ATLANTIC STATES STRETCHING SW AND WEST ACROSS THE SOUTHEAST. LARGE AREA OF FOG ASSOCIATED WITH THIS SYSTEM EXTENDED THIS MORNING AS FAR SOUTH AS CENTRAL FLORIDA AND DOWN THE SOUTHWEST FLORIDA COAST. AT THE MID LEVELS SHORT WAVE TROUGH RESPONSIBLE FOR YESTERDAY`S CONVECTION IS NOW EAST OF THE PENINSULA WITH LOW AND MID LEVEL RIDGE NOW BEGINNING TO BUILD INTO THE REGION FROM THE SOUTHWEST. LOOKING AT THE 12Z MODIFIED CONVECTIVE PARAMETERS THE LOW LEVEL INSTABILITY REMAINS VERY LIMITED AS IT WAS YESTERDAY. THAT COMBINED WITH WARMER AND LESS STEEP MID LEVEL LAPSE RATES MEAN THE POTENTIAL FOR CONVECTION TODAY IS LESS. IN FACT, LOOKING AT AN ENSEMBLE OF HI RES MODELS THAT INCLUDE THE NATIONAL ARW AND NMM EAST, THE LOCAL ARW AND NMM RUNS, AND THE HRRR SUPPORT THE CURRENT FORECAST WITH POPS RANGING FROM 10 PERCENT EASTERN PART OF THE CWA TO 20-30 PERCENT INTERIOR AND WEST COAST THIS AFTERNOON AND EARLY EVENING WITH THE CAVEAT THAT THAT MIGHT BE GENEROUS GIVEN LOCAL WRF CONFIGURATIONS AND THE HRRR KEEP US MOSTLY DRY. SO CURRENT FORECAST LOOKS ON TRACK WITH NO CHANGE IN OUTLOOK AS FAR AS POTENTIAL HAZARDOUS/IMPACT WEATHER CONDITIONS FROM THIS MORNING ASSESSMENT. MODIFIED SKY CONDITION GRIDS TO MORE ACCURATELY REFLECT THIS MORNING TRENDS. PREV DISCUSSION... /ISSUED 558 AM EST TUE FEB 28 2012/ AVIATION...HIGH PRES CENTERED OVR THE OH RVR VLY WL MOV E OVR NEW ENGLAND AND THE MID ATLC COAST TONIGHT AND OVER THE ATLC OVR THE NXT 24 HRS. THIS KEEPS AN E-ESE WND FLOW OVR S FLA THRU THE PD. VFR THRU THE PD THOUGH SOME ERLY MORN SHRA WITH BRIEF MVFR CIG WITH NO VSBY RESTRICTION THRU 15Z. MIFG PSBL AT KAPF FM TO 13Z. SFC WNDS E COAST 3 TO 6 MPH ATTM BCMG 8-11 KTS WITH SOME GUSTS PSBL TO MID TEENS AFT 14Z. AT KAPF...CALM WNDS BCMG ENE-E < 1- KTS WITH W COAST SEA BRZE DVLPG AFT 19Z WITH WNDS BCMG SW-WSW ARND 10 KTS. SKC THEN BCMG SCT030 AFT 15Z WITH VCTS AFT 20Z. PREV DISCUSSION... /ISSUED 246 AM EST TUE FEB 28 2012/ DISCUSSION...MID LEVEL TROUGH THAT PROVIDED AFTERNOON/EVENING CONVECTION ACROSS THE LAKE REGION TO COASTAL COLLIER COUNTY NOW EXITING TO THE EAST WITH THE SHRA ACTIVITY RAPIDLY DISSIPATING. EVEN THOUGH THIS TROUGH IS LEAVING THE REGION, FCST SOUNDINGS INDICATE RESIDUAL MOISTURE REMAINING IN PLACE ALONG WITH WEAK/MODERATE INSTABILITY. MOST MODELS INCLUDING THE GFS, NAM AND RAPID REFRESH SHOW AFTERNOON CONVECTION DEVELOPING IN THE EASTERLY FLOW ACROSS INTERIOR S FL AND THEN MOVING TOWARDS THE WEST. THUS HAVE INDICATED THIS IN THE GRIDS AND EVEN THOUGH THE INSTABILITY WILL BE MARGINAL, CANNOT RULE OUT AN OCCASIONAL LIGHTNING STRIKE SO ALSO ADDED THUNDER POSSIBLE. BY TONIGHT THROUGH THURSDAY, SEVERAL STRONG MID LEVEL TROUGHS WILL MOVE ACROSS THE NORTHERN TIER OF STATES IN THE ZONAL FLOW PATTERN WITH THE SUBTROPICAL RIDGE BUILDING BACK OVER THE FL PENINSULA. THIS WILL RESULT IN BENIGN WX CONDITIONS THROUGH THAT PERIOD WITH TEMPERATURES REMAINING ABOVE CLIMATOLOGICAL AVERAGES. AT THE SFC, A SFC RIDGE ACROSS THE SOUTHEAST STATES WILL SLOWLY SHIFT TO S FL BY THURSDAY AND THIS WILL PROVIDE FOR THE EASTERLY FLOW TO WEAKEN SIGNIFICANTLY OVER THE NEXT FEW DAYS WITH THE THREAT FOR RIP CURRENTS AT THE ATLANTIC BEACHES TO LESSEN AND THE CHANCES FOR INTERIOR LATE NIGHT FOG TO INCREASE. LOOKING AHEAD TO NEXT WEEKEND, A STRONGER TROUGH WILL MOVE INTO THE GREAT LAKES REGION AND CARVE OUT A LARGER SCALE TROUGH ACROSS THE EASTERN STATES WITH ITS ASSOCIATED COLD FRONT MOVING DOWN THE PENINSULA. THE PARENT LOW PRESSURE WILL REMAIN WELL NORTH OF THE REGION ALONG WITH THE MAIN DYNAMICS WITH THE FRONT LACKING MUCH PUSH BY THE TIME IT REACHES S FL BY LATE IN THE WEEKEND. STILL A FEW DEGREES OF COOLING CAN BE EXPECTED SUNDAY NIGHT AND MONDAY WITH CHANCES OF RAINFALL LOOKING MINIMAL. MARINE...THE EASTERLY WIND WILL CONTINUE AND DIMINISH THROUGH TODAY BECOMING SOUTHEAST ON WEDNESDAY AND THEN SOUTH ON SATURDAY AHEAD OF THE APPROACHING FRONT. SEAS WILL GENERALLY BE 4 FT OR LESS THROUGH THE PERIOD. FIRE WEATHER...NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 71 83 69 83 / - - - - FORT LAUDERDALE 73 82 73 83 / - - - - MIAMI 72 83 72 84 / - - - - NAPLES 66 85 65 85 / 20 - - - && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ PUBLIC/MARINE...52/SANTOS AVIATION/FIRE/RADAR...59/MOLLEDA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
114 PM MST TUE FEB 28 2012 .UPDATE... ISSUED AT 107 PM MST TUE FEB 28 2012 HAD TO RAISE MAXES EVEN MORE FROM EARLIER. REMAINDER OF FORECAST APPEARS TO BE ON TRACK AT THIS TIME. UPDATE ISSUED AT 1104 AM MST TUE FEB 28 2012 WINDS OVER THE SOUTHWEST PORTION OF THE FORECAST AREA AND TO THE SOUTHWEST OF THE AREA HAVE BEGUN TO GUST TO 60 MPH OR GREATER. GLD VWP SHOWS THAT 50 KNOTS PLUS IS GETTING WITHIN 1 TO 2 THOUSAND OF THE SURFACE. BELIEVE RUC IS CATCHING THE LOW LEVEL WINDS THE BEST BUT IT HAS THE HIGHEST BAND OF WINDS TOO FAR EAST. GOING BY CURRENT TRENDS...RUC...AND MODELS UNDERDOING THE LAPSE RATES...HAVE DECIDED TO PUT THE HIGH WIND WARNING OUT FOR THE ENTIRE AREA ALTHOUGH CLOUD COVER MAY INHIBIT THAT SOME IN THE EAST. UPDATE ISSUED AT 1004 AM MST TUE FEB 28 2012 JUST COMPLETED AN UPDATE. OVERALL THE RUC AND TO A LESSER EXTENT THE NAM IS CATCHING THE LOW LEVEL MOISTURE/THERMAL FIELDS THE BEST. INITIAL PROBLEM WAS WEATHER/POPS. SOME FOG STILL GOING BUT PER RUC SHOULD BE GONE SHORTLY. DRY SLOT PER SATELLITE HAS PUSHED OVER THE AREA ALREADY. MODELS LOOK BEHIND AND NOT DRY ENOUGH WITH THIS FEATURE. WHAT PRECIPITATION THERE WAS HAS NOW MOVED EAST OUT OF THE AREA AHEAD OF THE DRY SLOT. PER SATELLITE AND THE ABQ SOUNDING AM REALLY CONCERNED IF WILL SEE ANY MORE PRECIPITATION FROM WHAT WE HAD. THERE IS A DRY LINE AND SOME MID LEVEL LIFT BUT BELIEVE THE MOISTURE WILL BE GOOD ENOUGH FOR ANYTHING WIDESPREAD. THE NAM LIMITS THE INSTABILITY TO THE FAR EAST BY LATE THIS AFTERNOON BUT WHERE THIS INSTABILITY IS THE AIR MASS MAY BE CAPPED. ACTIVITY IS BLOSSOMING TO THE NORTHEAST OF THE AREA AT THIS TIME...AND BELIEVE THAT IS WHERE THAT WILL BE. CANNOT TOTALLY RULE OUT AN ISOLATED THUNDERSTORM IN THE EAST INTO EARLY THIS EVENING. BASED ON THE UPPER LOW TRAJECTORY THINK IT WILL BE DRY AFTER THAT. RUC IS CLOSEST TO REALITY ON TEMPS/DEWPOINTS AND USED FOR THE UPDATE. THIS MEANS WARMER TEMPERATURES AND HIGHER DEWPOINTS THAN CURRENTLY DEPICTED. ALSO ADJUSTED SKY COVER BASED ON REALITY. AT THIS TIME...WINDS LOOK FINE BASED ON THE LATEST DATA BUT WILL CONTINUE TO WATCH CLOSELY. UPDATE ISSUED AT 735 AM MST TUE FEB 28 2012 AREA OBSERVATIONS SHOWING WIDESPREAD STRATUS OVER THE ENTIRE AREA WITH AREAS OF FOG AT MOST LOCATIONS AS WELL. EXPECT THE FOG AND STRATUS/CLOUD COVER TO CONTINUE TO BE GREATER THAN CURRENTLY DEPICTED DUE TO CONTINUED LOW LEVEL MOISTURE INFLOW. WINDS LOOK FINE AT THIS TIME WITH ADVISORY CRITERIA ALREADY BEING REACHED IN SOME LOCATIONS. WILL NEED TO ADDRESS THE FORECAST AGAIN SHORTLY ESPECIALLY IF THE WIND SHIFT TO SOUTHWEST AND DRIER AIR DOES NOT GET IN HERE AS FAST AS CURRENTLY EXPECTED. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 107 PM MST TUE FEB 28 2012 WINDS WILL HAVE DECREASED SIGNIFICANTLY THIS EVENING FROM WHAT OCCURRED TODAY. HOWEVER...IT APPEARS THAT THEY WILL STAY IN THE 15 TO 25 MPH RANGE AND GUSTY AT TIMES. THIS SHOULD KEEP TEMPERATURES FROM DROPPING TOO MUCH SO RAISED THEM FROM THE PREVIOUS PACKAGE. MOISTURE/INSTABILITY AXIS EXITS THE FORECAST AREA EARLY THIS EVENING AND THAT IS WHEN THE PRECIPITATION SHOULD END. AT THIS TIME NOT EXPECTING ANY WARP AROUND TO OCCUR DUE TO THE PATH THE UPPER LOW IS TAKING. CURRENT SATELLITE AND RADAR TRENDS SUPPORT THIS. EVEN WITH THE CLOUD COVER...MODELS WERE ON THE COOL SIDE WITH TODAYS MAXES. SO BASED ON THE TRENDS...PROGGED 850 MB TEMPERATURES...SIMILAR TO TODAYS 850 MB TEMPERATURES...WESTERLY WINDS AND LOW DEWPOINTS...RAISED MAXES INTO THE 60S FOR MOST LOCATIONS. IF THESE MAXES AND THE LOW DEWPOINTS ARE REALIZED...WILL NEED ANOTHER FIRE WEATHER HIGHLIGHT FOR TOMORROW. BUT TO AVOID CONFUSION WITH THE CURRENT HIGHLIGHTS...WILL NOT ISSUE IT AND LET THE EVENING TAKE ANOTHER LOOK AT IT. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 228 AM MST TUE FEB 28 2012 DRY CONDITIONS CONTINUE WITH A RIDGE OVER THE PLAINS ON WEDNESDAY NIGHT. THE RIDGE SHIFT EAST THURSDAY AHEAD OF THE NEXT TROUGH. POPS WILL REMAIN NIL UNTIL THURSDAY NIGHT WHEN DYNAMICS FROM THE TROUGH AND ASSOCIATED COLD FRONT MOVE INTO THE FA. PLAN TO CONTINUE CHANCE POPS WHICH WILL BE TIED TO THE FRONT.POPS WILL DECREASE TO SLIGHT CHANCE BEHIND THE FRONT. SOUNDINGS INDICATE A CHANGE FROM RAIN TO SNOW BEHIND THE FRONT WHICH ENTERS THE FA AROUND 06Z FRIDAY. DUE TO SPEED OF FRONT SNOWFALL SHOULD ONLY AMOUNT TO A FEW TENTHS OF AN INCH. DAYS 4-7...THE UPPER TROUGH AND SURFACE LOW WILL BE EXITING THE CENTRAL HIGH PLAINS REGION ON FRIDAY WITH LIGHT PRECIPITATION DIMINISHING DURING THE DAY. THE HIGH AMPLITUDE RIDGE OVER THE EASTERN PACIFIC AND WESTERN UNITED STATES BEGINS MOVING OVER THE REMAINDER OF THE WESTERN U.S. OVER THE WEEKEND. NORTHWEST FLOW OVER THE FORECAST AREA WILL TRANSITION TO WESTERLY FLOW ALOFT WITH A LEE TROUGH DEVELOPING IN RESPONSE BY EARLY NEXT WEEK AS THE RIDGE AXIS MOVES OVER THE ROCKIES SUNDAY NIGHT AND THE PLAINS REGION ACROSS THE THE CENTRAL U.S. BY LATE MONDAY. EXCEPT FOR FRIDAY...THIS PERIOD WILL REMAIN DRY WITH TEMPERATURES WARMING THROUGH THE BEGINNING OF NEXT WEEK. TEMPERATURES WILL BE ABOVE NORMAL FROM SUNDAY THROUGH TUESDAY WITH HIGHS IN THE 60S ON MONDAY AND TUESDAY AND LOWS IN THE MIDDLE TO UPPER 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1040 AM MST TUE FEB 28 2012 TRICKY SET OF TAFS DUE TO LOW CLOUDS AND PRECIPITATION UNCERTAINTY. CONDITIONS BECOME VFR AT KGLD AND EXPECT THAT TO CONTINUE. STRONG AND GUSTY WINDS WILL CONTINUE THROUGH THE ENTIRE ALTHOUGH THE STRENGTH WILL DROP NEAR SUNSET. AT KMCK MVFR OR NEAR MVFR CIGS TO START OUT AND THEN SHOULD CLEAR. THERE IS A THREAT OF AN ISOLATED -TSRA NEAR THERE BUT BELIEVE MAIN THREAT IS TO THE NORTH OF THE AREA. KEPT VCTS IN THERE THROUGH 00Z. TRENDS FOR THE STRONG AND GUSTY WINDS WILL BE THE SAME KGLD. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ090>092. RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ254. KS...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016-027>029-041-042. RED FLAG WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ027-028-041-042. NE...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR NEZ079>081. && $$ UPDATE...BULLER SHORT TERM...BULLER LONG TERM....FS/LOCKHART AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1110 AM MST TUE FEB 28 2012 .UPDATE... ISSUED AT 1104 AM MST TUE FEB 28 2012 WINDS OVER THE SOUTHWEST PORTION OF THE FORECAST AREA AND TO THE SOUTHWEST OF THE AREA HAVE BEGUN TO GUST TO 60 MPH OR GREATER. GLD VWP SHOWS THAT 50 KNOTS PLUS IS GETTING WITHIN 1 TO 2 THOUSAND OF THE SURFACE. BELIEVE RUC IS CATCHING THE LOW LEVEL WINDS THE BEST BUT IT HAS THE HIGHEST BAND OF WINDS TOO FAR EAST. GOING BY CURRENT TRENDS...RUC...AND MODELS UNDERDOING THE LAPSE RATES...HAVE DECIDED TO PUT THE HIGH WIND WARNING OUT FOR THE ENTIRE AREA ALTHOUGH CLOUD COVER MAY INHIBIT THAT SOME IN THE EAST. UPDATE ISSUED AT 1004 AM MST TUE FEB 28 2012 JUST COMPLETED AN UPDATE. OVERALL THE RUC AND TO A LESSER EXTENT THE NAM IS CATCHING THE LOW LEVEL MOISTURE/THERMAL FIELDS THE BEST. INITIAL PROBLEM WAS WEATHER/POPS. SOME FOG STILL GOING BUT PER RUC SHOULD BE GONE SHORTLY. DRY SLOT PER SATELLITE HAS PUSHED OVER THE AREA ALREADY. MODELS LOOK BEHIND AND NOT DRY ENOUGH WITH THIS FEATURE. WHAT PRECIPITATION THERE WAS HAS NOW MOVED EAST OUT OF THE AREA AHEAD OF THE DRY SLOT. PER SATELLITE AND THE ABQ SOUNDING AM REALLY CONCERNED IF WILL SEE ANY MORE PRECIPITATION FROM WHAT WE HAD. THERE IS A DRY LINE AND SOME MID LEVEL LIFT BUT BELIEVE THE MOISTURE WILL BE GOOD ENOUGH FOR ANYTHING WIDESPREAD. THE NAM LIMITS THE INSTABILITY TO THE FAR EAST BY LATE THIS AFTERNOON BUT WHERE THIS INSTABILITY IS THE AIR MASS MAY BE CAPPED. ACTIVITY IS BLOSSOMING TO THE NORTHEAST OF THE AREA AT THIS TIME...AND BELIEVE THAT IS WHERE THAT WILL BE. CANNOT TOTALLY RULE OUT AN ISOLATED THUNDERSTORM IN THE EAST INTO EARLY THIS EVENING. BASED ON THE UPPER LOW TRAJECTORY THINK IT WILL BE DRY AFTER THAT. RUC IS CLOSEST TO REALITY ON TEMPS/DEWPOINTS AND USED FOR THE UPDATE. THIS MEANS WARMER TEMPERATURES AND HIGHER DEWPOINTS THAN CURRENTLY DEPICTED. ALSO ADJUSTED SKY COVER BASED ON REALITY. AT THIS TIME...WINDS LOOK FINE BASED ON THE LATEST DATA BUT WILL CONTINUE TO WATCH CLOSELY. UPDATE ISSUED AT 735 AM MST TUE FEB 28 2012 AREA OBSERVATIONS SHOWING WIDESPREAD STRATUS OVER THE ENTIRE AREA WITH AREAS OF FOG AT MOST LOCATIONS AS WELL. EXPECT THE FOG AND STRATUS/CLOUD COVER TO CONTINUE TO BE GREATER THAN CURRENTLY DEPICTED DUE TO CONTINUED LOW LEVEL MOISTURE INFLOW. WINDS LOOK FINE AT THIS TIME WITH ADVISORY CRITERIA ALREADY BEING REACHED IN SOME LOCATIONS. WILL NEED TO ADDRESS THE FORECAST AGAIN SHORTLY ESPECIALLY IF THE WIND SHIFT TO SOUTHWEST AND DRIER AIR DOES NOT GET IN HERE AS FAST AS CURRENTLY EXPECTED. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 228 AM MST TUE FEB 28 2012 THE MAIN WEATHER TODAY WILL BE WIND...NOT PRECIPITATION. MODELS INDICATE A HIGH END WIND ADVISORY ACROSS ALL ZONES EXCEPT THE NORTHWEST WHERE WIND WILL STILL REACH ADVISORY FOR A BRIEF TIME. THEREFORE HAVE EXPANDED THE CURRENT WIND ADVISORY TO INCLUDE ALL OF THE FA. DUE TO THE LACK OF PRECIPITATION AND STRONG WIND, RH VALUES WILL DROP TO CRITICAL FIRE WEATHER LEVELS OVER THE SOUTH FA THIS AFTERNOON. PLAN ON ISSUING A RED FLAG WARNING TO COVER THAT AREA AS WELL (SEE DETAILS BELOW). FORECAST SOUNDINGS ACROSS THE FA INDICATE PRECIPITATION SHOULD BE ALL LIQUID. AROUND 200 J/KG CAPE WILL BE AVAILABLE FOR SOME POSSIBLE THUNDERSTORMS. THE SYSTEM WILL MOVE THROUGH THE FA QUICKLY. SOME LIGHT SHOWERS/ISOLATED THUNDERSTORMS MAY LINGER IN THE EAST LATE THIS AFTERNOON. SUBSIDENCE WILL MOVE INTO THE FA THIS EVENING AND CONTINUE THROUGH WEDNESDAY AS A RIDGE BUILDS INTO THE PLAINS. CONSEQUENTLY POPS WILL BE NIL FOR TONIGHT/WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 228 AM MST TUE FEB 28 2012 DRY CONDITIONS CONTINUE WITH A RIDGE OVER THE PLAINS ON WEDNESDAY NIGHT. THE RIDGE SHIFT EAST THURSDAY AHEAD OF THE NEXT TROUGH. POPS WILL REMAIN NIL UNTIL THURSDAY NIGHT WHEN DYNAMICS FROM THE TROUGH AND ASSOCIATED COLD FRONT MOVE INTO THE FA. PLAN TO CONTINUE CHANCE POPS WHICH WILL BE TIED TO THE FRONT.POPS WILL DECREASE TO SLIGHT CHANCE BEHIND THE FRONT. SOUNDINGS INDICATE A CHANGE FROM RAIN TO SNOW BEHIND THE FRONT WHICH ENTERS THE FA AROUND 06Z FRIDAY. DUE TO SPEED OF FRONT SNOWFALL SHOULD ONLY AMOUNT TO A FEW TENTHS OF AN INCH. DAYS 4-7...THE UPPER TROUGH AND SURFACE LOW WILL BE EXITING THE CENTRAL HIGH PLAINS REGION ON FRIDAY WITH LIGHT PRECIPITATION DIMINISHING DURING THE DAY. THE HIGH AMPLITUDE RIDGE OVER THE EASTERN PACIFIC AND WESTERN UNITED STATES BEGINS MOVING OVER THE REMAINDER OF THE WESTERN U.S. OVER THE WEEKEND. NORTHWEST FLOW OVER THE FORECAST AREA WILL TRANSITION TO WESTERLY FLOW ALOFT WITH A LEE TROUGH DEVELOPING IN RESPONSE BY EARLY NEXT WEEK AS THE RIDGE AXIS MOVES OVER THE ROCKIES SUNDAY NIGHT AND THE PLAINS REGION ACROSS THE THE CENTRAL U.S. BY LATE MONDAY. EXCEPT FOR FRIDAY...THIS PERIOD WILL REMAIN DRY WITH TEMPERATURES WARMING THROUGH THE BEGINNING OF NEXT WEEK. TEMPERATURES WILL BE ABOVE NORMAL FROM SUNDAY THROUGH TUESDAY WITH HIGHS IN THE 60S ON MONDAY AND TUESDAY AND LOWS IN THE MIDDLE TO UPPER 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1040 AM MST TUE FEB 28 2012 TRICKY SET OF TAFS DUE TO LOW CLOUDS AND PRECIPITATION UNCERTAINTY. CONDITIONS BECOME VFR AT KGLD AND EXPECT THAT TO CONTINUE. STRONG AND GUSTY WINDS WILL CONTINUE THROUGH THE ENTIRE ALTHOUGH THE STRENGTH WILL DROP NEAR SUNSET. AT KMCK MVFR OR NEAR MVFR CIGS TO START OUT AND THEN SHOULD CLEAR. THERE IS A THREAT OF AN ISOLATED -TSRA NEAR THERE BUT BELIEVE MAIN THREAT IS TO THE NORTH OF THE AREA. KEPT VCTS IN THERE THROUGH 00Z. TRENDS FOR THE STRONG AND GUSTY WINDS WILL BE THE SAME KGLD. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ090>092. RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ254. KS...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016-027>029-041-042. RED FLAG WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ027-028-041-042. NE...HIGH WIND WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR NEZ079>081. && $$ UPDATE...BULLER SHORT TERM...FS LONG TERM....FS/LOCKHART AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1044 AM MST TUE FEB 28 2012 .UPDATE... ISSUED AT 1004 AM MST TUE FEB 28 2012 JUST COMPLETED AN UPDATE. OVERALL THE RUC AND TO A LESSER EXTENT THE NAM IS CATCHING THE LOW LEVEL MOISTURE/THERMAL FIELDS THE BEST. INITIAL PROBLEM WAS WEATHER/POPS. SOME FOG STILL GOING BUT PER RUC SHOULD BE GONE SHORTLY. DRY SLOT PER SATELLITE HAS PUSHED OVER THE AREA ALREADY. MODELS LOOK BEHIND AND NOT DRY ENOUGH WITH THIS FEATURE. WHAT PRECIPITATION THERE WAS HAS NOW MOVED EAST OUT OF THE AREA AHEAD OF THE DRY SLOT. PER SATELLITE AND THE ABQ SOUNDING AM REALLY CONCERNED IF WILL SEE ANY MORE PRECIPITATION FROM WHAT WE HAD. THERE IS A DRY LINE AND SOME MID LEVEL LIFT BUT BELIEVE THE MOISTURE WILL BE GOOD ENOUGH FOR ANYTHING WIDESPREAD. THE NAM LIMITS THE INSTABILITY TO THE FAR EAST BY LATE THIS AFTERNOON BUT WHERE THIS INSTABILITY IS THE AIR MASS MAY BE CAPPED. ACTIVITY IS BLOSSOMING TO THE NORTHEAST OF THE AREA AT THIS TIME...AND BELIEVE THAT IS WHERE THAT WILL BE. CANNOT TOTALLY RULE OUT AN ISOLATED THUNDERSTORM IN THE EAST INTO EARLY THIS EVENING. BASED ON THE UPPER LOW TRAJECTORY THINK IT WILL BE DRY AFTER THAT. RUC IS CLOSEST TO REALITY ON TEMPS/DEWPOINTS AND USED FOR THE UPDATE. THIS MEANS WARMER TEMPERATURES AND HIGHER DEWPOINTS THAN CURRENTLY DEPICTED. ALSO ADJUSTED SKY COVER BASED ON REALITY. AT THIS TIME...WINDS LOOK FINE BASED ON THE LATEST DATA BUT WILL CONTINUE TO WATCH CLOSELY. UPDATE ISSUED AT 735 AM MST TUE FEB 28 2012 AREA OBSERVATIONS SHOWING WIDESPREAD STRATUS OVER THE ENTIRE AREA WITH AREAS OF FOG AT MOST LOCATIONS AS WELL. EXPECT THE FOG AND STRATUS/CLOUD COVER TO CONTINUE TO BE GREATER THAN CURRENTLY DEPICTED DUE TO CONTINUED LOW LEVEL MOISTURE INFLOW. WINDS LOOK FINE AT THIS TIME WITH ADVISORY CRITERIA ALREADY BEING REACHED IN SOME LOCATIONS. WILL NEED TO ADDRESS THE FORECAST AGAIN SHORTLY ESPECIALLY IF THE WIND SHIFT TO SOUTHWEST AND DRIER AIR DOES NOT GET IN HERE AS FAST AS CURRENTLY EXPECTED. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 228 AM MST TUE FEB 28 2012 THE MAIN WEATHER TODAY WILL BE WIND...NOT PRECIPITATION. MODELS INDICATE A HIGH END WIND ADVISORY ACROSS ALL ZONES EXCEPT THE NORTHWEST WHERE WIND WILL STILL REACH ADVISORY FOR A BRIEF TIME. THEREFORE HAVE EXPANDED THE CURRENT WIND ADVISORY TO INCLUDE ALL OF THE FA. DUE TO THE LACK OF PRECIPITATION AND STRONG WIND, RH VALUES WILL DROP TO CRITICAL FIRE WEATHER LEVELS OVER THE SOUTH FA THIS AFTERNOON. PLAN ON ISSUING A RED FLAG WARNING TO COVER THAT AREA AS WELL (SEE DETAILS BELOW). FORECAST SOUNDINGS ACROSS THE FA INDICATE PRECIPITATION SHOULD BE ALL LIQUID. AROUND 200 J/KG CAPE WILL BE AVAILABLE FOR SOME POSSIBLE THUNDERSTORMS. THE SYSTEM WILL MOVE THROUGH THE FA QUICKLY. SOME LIGHT SHOWERS/ISOLATED THUNDERSTORMS MAY LINGER IN THE EAST LATE THIS AFTERNOON. SUBSIDENCE WILL MOVE INTO THE FA THIS EVENING AND CONTINUE THROUGH WEDNESDAY AS A RIDGE BUILDS INTO THE PLAINS. CONSEQUENTLY POPS WILL BE NIL FOR TONIGHT/WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 228 AM MST TUE FEB 28 2012 DRY CONDITIONS CONTINUE WITH A RIDGE OVER THE PLAINS ON WEDNESDAY NIGHT. THE RIDGE SHIFT EAST THURSDAY AHEAD OF THE NEXT TROUGH. POPS WILL REMAIN NIL UNTIL THURSDAY NIGHT WHEN DYNAMICS FROM THE TROUGH AND ASSOCIATED COLD FRONT MOVE INTO THE FA. PLAN TO CONTINUE CHANCE POPS WHICH WILL BE TIED TO THE FRONT.POPS WILL DECREASE TO SLIGHT CHANCE BEHIND THE FRONT. SOUNDINGS INDICATE A CHANGE FROM RAIN TO SNOW BEHIND THE FRONT WHICH ENTERS THE FA AROUND 06Z FRIDAY. DUE TO SPEED OF FRONT SNOWFALL SHOULD ONLY AMOUNT TO A FEW TENTHS OF AN INCH. DAYS 4-7...THE UPPER TROUGH AND SURFACE LOW WILL BE EXITING THE CENTRAL HIGH PLAINS REGION ON FRIDAY WITH LIGHT PRECIPITATION DIMINISHING DURING THE DAY. THE HIGH AMPLITUDE RIDGE OVER THE EASTERN PACIFIC AND WESTERN UNITED STATES BEGINS MOVING OVER THE REMAINDER OF THE WESTERN U.S. OVER THE WEEKEND. NORTHWEST FLOW OVER THE FORECAST AREA WILL TRANSITION TO WESTERLY FLOW ALOFT WITH A LEE TROUGH DEVELOPING IN RESPONSE BY EARLY NEXT WEEK AS THE RIDGE AXIS MOVES OVER THE ROCKIES SUNDAY NIGHT AND THE PLAINS REGION ACROSS THE THE CENTRAL U.S. BY LATE MONDAY. EXCEPT FOR FRIDAY...THIS PERIOD WILL REMAIN DRY WITH TEMPERATURES WARMING THROUGH THE BEGINNING OF NEXT WEEK. TEMPERATURES WILL BE ABOVE NORMAL FROM SUNDAY THROUGH TUESDAY WITH HIGHS IN THE 60S ON MONDAY AND TUESDAY AND LOWS IN THE MIDDLE TO UPPER 30S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1040 AM MST TUE FEB 28 2012 TRICKY SET OF TAFS DUE TO LOW CLOUDS AND PRECIPITATION UNCERTAINTY. CONDITIONS BECOME VFR AT KGLD AND EXPECT THAT TO CONTINUE. STRONG AND GUSTY WINDS WILL CONTINUE THROUGH THE ENTIRE ALTHOUGH THE STRENGTH WILL DROP NEAR SUNSET. AT KMCK MVFR OR NEAR MVFR CIGS TO START OUT AND THEN SHOULD CLEAR. THERE IS A THREAT OF AN ISOLATED -TSRA NEAR THERE BUT BELIEVE MAIN THREAT IS TO THE NORTH OF THE AREA. KEPT VCTS IN THERE THROUGH 00Z. TRENDS FOR THE STRONG AND GUSTY WINDS WILL BE THE SAME KGLD. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ090>092. RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ254. KS...WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016-027>029-041-042. RED FLAG WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ027-028-041-042. NE...WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR NEZ079>081. && $$ UPDATE...BULLER SHORT TERM...FS LONG TERM....FS/LOCKHART AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1014 AM MST TUE FEB 28 2012 .UPDATE... ISSUED AT 1004 AM MST TUE FEB 28 2012 JUST COMPLETED AN UPDATE. OVERALL THE RUC AND TO A LESSER EXTENT THE NAM IS CATCHING THE LOW LEVEL MOISTURE/THERMAL FIELDS THE BEST. INITIAL PROBLEM WAS WEATHER/POPS. SOME FOG STILL GOING BUT PER RUC SHOULD BE GONE SHORTLY. DRY SLOT PER SATELLITE HAS PUSHED OVER THE AREA ALREADY. MODELS LOOK BEHIND AND NOT DRY ENOUGH WITH THIS FEATURE. WHAT PRECIPITATION THERE WAS HAS NOW MOVED EAST OUT OF THE AREA AHEAD OF THE DRY SLOT. PER SATELLITE AND THE ABQ SOUNDING AM REALLY CONCERNED IF WILL SEE ANY MORE PRECIPITATION FROM WHAT WE HAD. THERE IS A DRY LINE AND SOME MID LEVEL LIFT BUT BELIEVE THE MOISTURE WILL BE GOOD ENOUGH FOR ANYTHING WIDESPREAD. THE NAM LIMITS THE INSTABILITY TO THE FAR EAST BY LATE THIS AFTERNOON BUT WHERE THIS INSTABILITY IS THE AIR MASS MAY BE CAPPED. ACTIVITY IS BLOSSOMING TO THE NORTHEAST OF THE AREA AT THIS TIME...AND BELIEVE THAT IS WHERE THAT WILL BE. CANNOT TOTALLY RULE OUT AN ISOLATED THUNDERSTORM IN THE EAST INTO EARLY THIS EVENING. BASED ON THE UPPER LOW TRAJECTORY THINK IT WILL BE DRY AFTER THAT. RUC IS CLOSEST TO REALITY ON TEMPS/DEWPOINTS AND USED FOR THE UPDATE. THIS MEANS WARMER TEMPERATURES AND HIGHER DEWPOINTS THAN CURRENTLY DEPICTED. ALSO ADJUSTED SKY COVER BASED ON REALITY. AT THIS TIME...WINDS LOOK FINE BASED ON THE LATEST DATA BUT WILL CONTINUE TO WATCH CLOSELY. UPDATE ISSUED AT 735 AM MST TUE FEB 28 2012 AREA OBSERVATIONS SHOWING WIDESPREAD STRATUS OVER THE ENTIRE AREA WITH AREAS OF FOG AT MOST LOCATIONS AS WELL. EXPECT THE FOG AND STRATUS/CLOUD COVER TO CONTINUE TO BE GREATER THAN CURRENTLY DEPICTED DUE TO CONTINUED LOW LEVEL MOISTURE INFLOW. WINDS LOOK FINE AT THIS TIME WITH ADVISORY CRITERIA ALREADY BEING REACHED IN SOME LOCATIONS. WILL NEED TO ADDRESS THE FORECAST AGAIN SHORTLY ESPECIALLY IF THE WIND SHIFT TO SOUTHWEST AND DRIER AIR DOES NOT GET IN HERE AS FAST AS CURRENTLY EXPECTED. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 228 AM MST TUE FEB 28 2012 THE MAIN WEATHER TODAY WILL BE WIND...NOT PRECIPITATION. MODELS INDICATE A HIGH END WIND ADVISORY ACROSS ALL ZONES EXCEPT THE NORTHWEST WHERE WIND WILL STILL REACH ADVISORY FOR A BRIEF TIME. THEREFORE HAVE EXPANDED THE CURRENT WIND ADVISORY TO INCLUDE ALL OF THE FA. DUE TO THE LACK OF PRECIPITATION AND STRONG WIND, RH VALUES WILL DROP TO CRITICAL FIRE WEATHER LEVELS OVER THE SOUTH FA THIS AFTERNOON. PLAN ON ISSUING A RED FLAG WARNING TO COVER THAT AREA AS WELL (SEE DETAILS BELOW). FORECAST SOUNDINGS ACROSS THE FA INDICATE PRECIPITATION SHOULD BE ALL LIQUID. AROUND 200 J/KG CAPE WILL BE AVAILABLE FOR SOME POSSIBLE THUNDERSTORMS. THE SYSTEM WILL MOVE THROUGH THE FA QUICKLY. SOME LIGHT SHOWERS/ISOLATED THUNDERSTORMS MAY LINGER IN THE EAST LATE THIS AFTERNOON. SUBSIDENCE WILL MOVE INTO THE FA THIS EVENING AND CONTINUE THROUGH WEDNESDAY AS A RIDGE BUILDS INTO THE PLAINS. CONSEQUENTLY POPS WILL BE NIL FOR TONIGHT/WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY) ISSUED AT 228 AM MST TUE FEB 28 2012 DRY CONDITIONS CONTINUE WITH A RIDGE OVER THE PLAINS ON WEDNESDAY NIGHT. THE RIDGE SHIFT EAST THURSDAY AHEAD OF THE NEXT TROUGH. POPS WILL REMAIN NIL UNTIL THURSDAY NIGHT WHEN DYNAMICS FROM THE TROUGH AND ASSOCIATED COLD FRONT MOVE INTO THE FA. PLAN TO CONTINUE CHANCE POPS WHICH WILL BE TIED TO THE FRONT.POPS WILL DECREASE TO SLIGHT CHANCE BEHIND THE FRONT. SOUNDINGS INDICATE A CHANGE FROM RAIN TO SNOW BEHIND THE FRONT WHICH ENTERS THE FA AROUND 06Z FRIDAY. DUE TO SPEED OF FRONT SNOWFALL SHOULD ONLY AMOUNT TO A FEW TENTHS OF AN INCH. DAYS 4-7...THE UPPER TROUGH AND SURFACE LOW WILL BE EXITING THE CENTRAL HIGH PLAINS REGION ON FRIDAY WITH LIGHT PRECIPITATION DIMINISHING DURING THE DAY. THE HIGH AMPLITUDE RIDGE OVER THE EASTERN PACIFIC AND WESTERN UNITED STATES BEGINS MOVING OVER THE REMAINDER OF THE WESTERN U.S. OVER THE WEEKEND. NORTHWEST FLOW OVER THE FORECAST AREA WILL TRANSITION TO WESTERLY FLOW ALOFT WITH A LEE TROUGH DEVELOPING IN RESPONSE BY EARLY NEXT WEEK AS THE RIDGE AXIS MOVES OVER THE ROCKIES SUNDAY NIGHT AND THE PLAINS REGION ACROSS THE THE CENTRAL U.S. BY LATE MONDAY. EXCEPT FOR FRIDAY...THIS PERIOD WILL REMAIN DRY WITH TEMPERATURES WARMING THROUGH THE BEGINNING OF NEXT WEEK. TEMPERATURES WILL BE ABOVE NORMAL FROM SUNDAY THROUGH TUESDAY WITH HIGHS IN THE 60S ON MONDAY AND TUESDAY AND LOWS IN THE MIDDLE TO UPPER 30S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 351 AM MST TUE FEB 28 2012 IFR CONDITIONS EXPECTED THIS MORNING AT KGLD AND KMCK AS UPPER SYSTEM IMPACTS THE AREA. PRECIPITATION WILL BE BRIEF WHILE STRONG WIND WILL PERSIST UNTIL EVENING. VFR CONDITIONS WILL RETURN BY MID AFTERNOON AT BOTH SITES WITH CLEARING AND DECREASING WIND OVERNINGHT. && .GLD WATCHES/WARNINGS/ADVISORIES... CO...WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ090>092. RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ254. KS...WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016-027>029-041-042. RED FLAG WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ027-028-041-042. NE...WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR NEZ079>081. && $$ UPDATE...BULLER SHORT TERM...FS LONG TERM....FS/LOCKHART AVIATION...FS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
412 PM EST TUE FEB 28 2012 .SYNOPSIS... ISSUED AT 359 PM EST TUE FEB 28 2012 A LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS WILL CONTINUE TO ADVANCE TOWARDS NORTHERN MICHIGAN...GENERATING A WINTRY MIX OF PRECIPITATION WHICH WILL BEGIN LATE TONIGHT...AND LAST THROUGH WEDNESDAY NIGHT...WITH HEAVY SNOW EXPECTED OVER THE UPPER PENINSULA. AFTER A BRIEF BREAK THURSDAY AS AN AREA OF HIGH PRESSURE BUILDS OVER THE REGION...ANOTHER LOW PRESSURE SYSTEM WILL START TO TAKE SHAPE IN THE WESTERN GREAT LAKES ON FRIDAY. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 359 PM EST TUE FEB 28 2012 TOP DOWN SATURATION ONGOING OVER THE FORECAST AREA WITH SNOW ALREADY HAVING REACHING THE GROUND FROM BEAVER ISLAND EAST TO MACKINAC ISLAND. THIS SNOW HAS DEVELOPED LESS IN RESPONSE TO OUR UPCOMING WEATHER-MAKER...AND MORE IN-LINE WITH THE RIGHT ENTRANCE REGION OF A H25 JET MAX THAT EXTENDS FROM LAKE SUPERIOR SOUTH AND EAST INTO SOUTHERN ONTARIO...AS WELL AS A WEAK PV ANOMALY SEEN IN WATER VAPOR IMAGERY NOW JUST NORTH EAST OF LAKE SUPERIOR AND RACING EAST. THESE FEATURES...COMBINED WITH STRENGTHENING UPSTREAM WARM ADVECTION IN ADVANCE OF EJECTING FOUR CORNERS SHORTWAVE HAS HELPED CONSOLIDATE A BAND OF MID LEVEL FRONTOGENESIS...WITH JUST ENOUGH MOISTURE FOR SNOW TO REACH THE GROUND. ANYTHING THROUGH THIS EVENING SHOULD BE PRETTY LIGHT...HOWEVER...AND AS THE AFOREMENTIONED SHORTWAVE PUSHES EAST...WE WILL LIKELY SEE THIS ACTIVITY DRY UP SOME WITH PERHAPS JUST A FEW FLURRIES OVER NORTHWEST LOWER AND THE STRAITS REGION WITH STRENGTHENING DRY LOW LEVEL SOUTHEASTERLY FLOW HELPING ERODE ANY MOISTURE. EARLY AFTERNOON HRRR IS IN GOOD AGREEMENT WITH THESE TRENDS. A WINTER WEATHER MESS IS SET TO ARRIVE LATE TONIGHT COURTESY OF THE AFOREMENTIONED SHORTWAVE EJECTING OUT OF THE SOUTHWESTERN STATES...BEING KICKED NORTH AND EAST BY ARRIVING ENERGY ALONG THE PACIFIC COAST. MODEL INITIALIZATION WAS GENERALLY GOOD AT 12UTC WITH ANY ERRORS NOT ENOUGH TO PRODUCE SIGNIFICANT DIFFERENCES IN FORECASTS FROM THE NAM/GFS/ECMWF. THE TREND OVER THE PAST 24 HOURS OF A MORE ROBUST AND NORTHERN SOLUTION TO THE SURFACE LOW HAS ENDED WITH ALL GUIDANCE SHOWING A SLIGHT SOUTHWARD SHIFT IN THEIR 12Z SOLUTIONS WITH GOOD CLUSTERING OF THE GEFS AROUND THE GFS AND THE 09Z SREF CLOSE TO THE 12Z NAM. THIS BRINGS LOW PRESSURE NORTHEAST ACROSS THE CENTRAL PLAINS TO A POSITION OVER SOUTHWEST MINNESOTA BY DAYBREAK WEDNESDAY /NEAR 990 MB/ WITH A LOW TRACK THAT THEN MOVES JUST ABOUT DUE EAST AS THE SYSTEM OCCLUDES. IN TERMS OF PATTERN RECOGNITION...H7 LOW TRACK MOVES EAST ACROSS NORTHERN LOWER SOMETIME WEDNESDAY NIGHT...SUGGESTING THE BEST CHANCES FOR PROLONGED SNOWS WILL BE FROM THE TIP OF THE MITT NORTH. OUR WEATHER-MAKER WILL HAVE AMPLE MOISTURE TO WORK WITH AS THE GULF WAS WIDE OPEN AS OF 12UTC WITH H85 DEWPOINTS AT OR ABOVE 10C STREAMING NORTH ACROSS TX/OK/AK/LA. THE RESULT OF STRENGTHENING MOISTURE ADVECTION WILL BE 1" PWATS MAKING A RUN AT THE SOUTHERN GREAT LAKES TONIGHT. TONIGHT...BAND OF STRONG ISENTROPIC ASCENT ON THE I290 SURFACE WILL SPREAD NORTH AS THE AFOREMENTIONED STREAM OF MOISTURE PUSHES NORTH. PRIMARY FORECAST CONCERN TONIGHT RESIDES AROUND PRECIPITATION START TIME...AS DRY LOW LEVEL SOUTHEASTERLY FLOW ATTEMPTS TO ERODE MOISTURE AS IT ARRIVES. THERE HAS BEEN A NOTICEABLE TREND TO SLOW PRECIPITATION ONSET TIME WITH THE 12UTC GUIDANCE...WHICH IS VERY REASONABLE GIVEN THE SETUP. HAVE ADJUSTED POPS FOR THIS REASON...WHICH SHOULD KEEP PRECIPITATION SOUTH OF THE BRIDGE THROUGH DAYBREAK. FURTHER SOUTH...A SWATH OF MODERATE TO POTENTIALLY HEAVY PRECIPITATION WILL ARRIVE FROM SOUTHWEST TO NORTHEAST. WITHIN THIS BAND...INGREDIENTS LOOK GOOD FOR SOME BANDED HEAVY SNOW POTENTIAL... WITH OMEGA BULLS-EYED NEAR OR AT OR JUST ABOVE THE CENTER OF THE DGZ WITH REDUCED EPV ALOFT AS STRONG WARM ADVECTION REDUCES MID LEVEL LAPSE RATES. PRECIPITATION TYPE ISSUES WILL ENSUE QUICKLY BEHIND INITIAL EDGE OF SNOWFALL AS WETBULB ZERO LINE AT H85 ARRIVES OVER MY FAR SOUTHWEST ZONES TOWARDS DAYBREAK. THEREFORE...WILL INTRODUCE A SLEET/FREEZING RAIN MIX AFTER 9Z IN THE FAR SOUTHEAST. THROUGH DAYBREAK...EXPECT 1 TO 3 INCHES OF SNOW ALONG AND SOUTHWEST OF A CHARLEVOIX TO GAYLORD TO HARRISVILLE LINE...WITH SNOW COMING DOWN PRETTY HEAVILY AS MORNING ARRIVES IN THESE SPOTS. TEMPERATURES WILL ONLY FALL OF A LITTLE OVERNIGHT...GENERALLY IN THE UPPER 20S TO AROUND FREEZING. TOUGH FORECAST FOR THE DAY WEDNESDAY AS LOW PRESSURE OCCLUDES AND WARM NOSE CONTINUES TO SLOWLY MOVE NORTH. FIRST THINGS FIRST...PRECIPITATION WILL CONTINUE TO PUSH NORTH AND SHOULD ARRIVE OVER EASTERN UPPER NO LATER THAN LATE MORNING/NOON. FURTHER SOUTH...BAND OF HEAVY SNOW WILL MAKE THE TRANSITION TO SLEET/FREEZING RAIN AS TEMPS ALOFT WARM...BUT IT/S LOOKING LIKE A PRETTY SMALL WINDOW FOR ICING POTENTIAL AS DEEP MOISTURE WILL RAPIDLY LIFT OUT OF MY SOUTHERN ZONES BY MID MORNING /PERHAPS QUICKER...HAVE SEEN THIS HAPPEN BEFORE/ TRANSITIONING PRECIPITATION TO DRIZZLE/ AND SHOWERS. WITH THE SLIGHTLY FURTHER SOUTH SOLUTION...EXPECT THAT ANY MIX WILL HAVE A TOUGH TIME REACHING MUCH FARTHER NORTH THAN M-32 WITH PERHAPS SOME SLEET MIXING AT TIMES UP TO M-68. BY AFTERNOON...EXPECT MOST LOCATIONS SOUTH OF M-68 TO TRANSITION TO SOME DRIZZLE OR SHOWERS...WITH STRONG H7-5 LAPSE RATES AND NON-NEGLIGIBLE ELEVATED INSTABILITY SUGGESTING ANY SHOWERS THAT DEVELOP IN THE AIRMASS BEHIND THE SURFACE OCCLUSION COULD BE ROBUST. SNOWFALL AMOUNTS WEDNESDAY LOOK GREATEST OVER EASTERN UPPER WHERE 12 HOUR TOTALS NEAR 6 INCHES LOOK LIKELY GIVEN THAT THE DRYSLOT WILL NEVER REACH THIS LOCATION. AMOUNTS WILL TAPER OFF FURTHER SOUTH AND HAVE GONE A LITTLE BELOW THE GUIDANCE CONSENSUS QPF GIVEN SYNOPTIC SETUP/PATTERN RECOGNITION. THIS WILL YIELD ADDITIONAL SNOWS 1-2 INCHES NEAR M-72 UP TO 3-5 INCHES NEAR M-68. SOUTH OF M-72 AND WEST OF US-131 THERE WILL LIKELY BE LITTLE/NO ADDITIONAL SNOW...WITH ICING AMOUNTS GENERALLY ONE TENTH OF AN INCH OR LESS. FINALLY THERE IS ALSO GOING TO BE A WIND ELEMENT AS LOW PRESSURE NEARS DURING THE DAY WEDNESDAY. THIS WILL LIKELY PRODUCE SOME BLOWING/DRIFTING OF SNOW THAT FALLS...PARTICULARLY NEAR THE STRAITS WHERE THE SNOW WILL BE /SLIGHTLY/ DRIER AND WINDS STRONGER. GUSTS TO 35 MPH WILL BE POSSIBLE IN THIS REGION. AS FOR HEADLINES...WILL ADD THE TIP OF THE MITT COUNTIES /EMMET CHEBOYGAN/ AS WELL AS PRESQUE ISLE TO THE WARNING GIVEN 4-6 INCHES OF SNOW AND LIKELY SIGNIFICANT BLOWING/DRIFTING NEAR THE COAST. FURTHER SOUTH...IN COORDINATION WITH GRR/DTX WILL TRANSITION ALL LOCATIONS TO A WINTER WEATHER ADVISORY FOR THE SNOW CHANGING TO MIX. ARNOTT && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 359 PM EST TUE FEB 28 2012 MAIN FOCUS OVER THE LONG TERM PORTION OF THE FORECAST WILL BE HANDLING THE DEPARTURE OF WEDNESDAY`S SYSTEM AND WITH THE EVOLUTION OF THE NEXT POTENTIALLY STRONG STORM SYSTEM FOR FRIDAY INTO THE WEEKEND...AND THE LAKE EFFECT SNOW CHANCES THEREAFTER. WEDNESDAY NIGHT...THE MESSY STORM SYSTEM WILL BE DEPARTING TO THE EAST WITH A TRACK GENERALLY ACROSS M-68. THE OCCLUDED LOW PRESSURE WILL CONTINUE TO WEAKEN ALONG WITH THE ASSOCIATED FORCING. THAT SAID...WE ARE STILL GOING TO HAVE BROAD CYCLONIC FLOW/CONVERGENCE FOR PRECIPITATION TO BE OCCURRING ALL OF NRN MICHIGAN FOR MOST OF THE NIGHT...ESPECIALLY IN THE EVENING AND A FEW HOURS PAST MIDNIGHT...AHEAD OF APPROACHING SFC/UPPER LOWS. TRYING TO PICK OUT THE PARTICULAR PRECIPITATION TYPES IN THE EARLY EVENING IS A RATHER DAUNTING TASK...AS INITIAL DRY SLOTTING ALOFT IS LIKELY TO RESULT IN SOME DRIZZLE TYPE PRECIP FROM NRN LOWER AND THEN INTO EASTERN UPPER DURING THE EVENING AND TO SOME DEGREE OVERNIGHT. IN ADDITION...AND DEPENDING ON RATE OF DECAY OF THE TROWAL...COULD EVEN SEE SOME EARLY EVENING SNOW/SLEET LINGERING OVER THE ALPENA AREA. THE DEEPEST MOISTURE WILL PASS THROUGH NRN LOWER FOR OCCASIONAL LIGHT SNOWS THROUGH MUCH OF THE NIGHT...WHILE SOME LIGHT SNOW AND OCCASIONAL DRIZZLY TYPE PRECIP COULD BE ON AND OFF ACROSS EASTERN UPPER THROUGH THE NIGHT. PRECIP WILL WIND DOWN ACROSS NW LOWER TOWARD DAYBREAK WITH THE ATMOSPHERE DRYING OUT MORE SUBSTANTIALLY. TOTAL SNOWFALL WILL GENERALLY BE AROUND AN INCH FOR MOST ALL OF NRN MICHIGAN...WITH SOME 2 INCH REPORTS LIKELY. THURSDAY THROUGH THURSDAY NIGHT...SOME ILL-DEFINED TROUGHING REMAINS STRETCHED OUT ACROSS NE LOWER THROUGH EASTERN UPPER THROUGH THE DAY WHILE MOISTURE CONTINUES TO EXIT EAST. ONLY SMALL CHANCES FOR LINGERING LIGHT PRECIP (LIGHT SNOW/FREEZING DRIZZLE) EARLY IN THE MORNING. THIS DAY WILL BE BETTER CHARACTERIZED BY RIDGING ALOFT AND DRYING...WHILE NEXT UPPER TROUGH SHARPENS/DROPS THROUGH THE ROCKIES WITH BROAD LOW PRESSURE IN THE CENTER OF THE COUNTRY. THROUGH THURSDAY NIGHT...A COUPLE OF AREAS OF LOW PRESSURE ARE EXPECTED TO BECOME MORE DEFINED. ONE WITH SHORTWAVE ACTIVITY IN SRN CANADA AND OUR NRN BORDER...AND ANOTHER NEAR KS/OK ASSOCIATED WITH STRONGER SHORTWAVE/STRENGTHENING UPPER JET DYNAMICS ROUNDING THE BASE OF THE UPPER TROUGH. SKIES WILL BE INCREASING IN CLOUDINESS THROUGH THE NIGHT WITHIN INITIAL WEAK PVA...WITH ONLY SMALL CHANCES OF BROAD SCALE THETA-E ADVECTION MOISTENING UP THE ATMOSPHERE ENOUGH FOR SOME LIGHT SNOW OR FLURRIES ACROSS NW LOWER THROUGH EASTERN UPPER. FRIDAY ONWARD...DETAILS ARE STILL UNCLEAR ON WHAT HAPPENS FRIDAY THROUGH SATURDAY...AS THERE ARE STILL CONSIDERABLE DIFFERENCES REGARDING THE SFC AND UPPER LEVEL PATTERNS IN MODEL SOLUTIONS. THE GENERAL IDEA IS FOR THE NRN/SRN STREAM WAVES TO UNDERGO SOME SORT OF PHASING FRIDAY INTO SATURDAY...WITH ONE CONSOLIDATED SFC LOW PRESSURE STRENGTHENING...OR POSSIBLY "BOMBING" OUT...DEEPENING NEARLY 30 MB OVER 18 HRS. NOW...THE MAIN QUESTION IS WHERE AND WHEN THIS WILL OCCUR...SINCE IT WILL HAVE OBVIOUS IMPLICATIONS ON THE SPECIFIC WEATHER TO OCCUR. GEM THE OUTLIER AND HAS WEAKEST AND FURTHEST EAST PHASING...WITH THE GFS THE MOST RADICAL IN STRENGTHENING. EVEN WITH THINGS BEING UNCLEAR ON MANY PARTS...THERE IS SOME DECENT AGREEMENT ON THE LOW PRESSURE GATHERING STRENGTH AS IT PASSES OVER OR JUST TO OUR EAST THROUGH SATURDAY. HOW MUCH MOISTURE IS INVOLVED...AND OTHER MORE DETAILED THINGS ARE DEFINITELY MORE UNCLEAR...BUT A RAIN/SNOW SCENARIO IS THE BEST FORECAST AT THIS POINT...WITH RAIN EAST AND SNOW IN THE NW CWA. CAN REFINE THE DETAILS AS THINGS UNFOLD. ONE OTHER COMMONALITY WITH THESE SOLUTIONS IS FOR COLD ENOUGH AIR TO DRAIN INTO NRN MICHIGAN WITH DEEP ENOUGH MOISTURE FOR A PERIOD OF LAKE EFFECT SNOW PRIMARILY SATURDAY NIGHT THROUGH SUNDAY NIGHT. MAYBE SOME DECENT ACCUMS IF THE SAME GENERAL IDEAS ARE UPHELD IN FUTURE MODEL RUNS. THINGS QUIET DOWN FROM LES LATE MONDAY/TUESDAY OR SO...WITH EVIDENCE OF STRONG WARMING ARRIVING TUESDAY AND POSSIBLY WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1252 PM EST TUE FEB 28 2012 ASIDE FROM SOME LIGHT SNOW AT KPLN NEXT COUPLE OF HRS...VFR CONDITIONS WILL PREVAIL INTO TONIGHT ACROSS NRN MI AS MID CLOUDS THICKEN OVERHEAD. PRECIP ARRIVES LATER TONIGHT AS STORM SYSTEM APPROACHES FROM THE SW. EXPECT WIDESPREAD MVFR/IFR CONDITIONS AFTER ROUGHLY 07Z AS SNOW...FREEZING RAIN...SLEET...AND RAIN ARRIVE. LLWS ALSO POSSIBLE AFTER 05Z WITH APPROACH OF WARM FRONT. && .MARINE... ISSUED AT 359 PM EST TUE FEB 28 2012 WILL GO AHEAD AND EXPAND GALE WARNINGS TO BASICALLY INCLUDE ALL ZONES SAVE STURGEON POINT TO ALABASTER AS BOUNDARY LAYER WINDS TO 40KTS /950MB TO 50KTS/ WITH SOME LLEVEL MIXING SUGGESTS THAT GUSTS TO GALE FORCE ARE LIKELY JUST ABOUT EVERYWHERE...WITH THE STRONGEST WINDS THROUGH THE STRAITS WHERE SOME FUNNELING/COASTAL CONVERGENCE WILL GIVE THINGS AN ADDED BOOST. WINDS AND WAVES WILL DIMINISH LATE WEDNESDAY NIGHT AND THURSDAY AS LOW PRESSURE PULLS EAST OF THE REGION. ANOTHER ROUND OF STRONG WINDS LOOKS POSSIBLE IN THE FRIDAY-SATURDAY TIMEFRAME AS A NEW LOW PRESSURE SYSTEM DEVELOPS IN THE GREAT LAKES REGION. THERE/S PLENTY OF TIME TO LOOK AT THIS SYSTEM...BUT AT THIS EARLY JUNCTURE GALES LOOK TO BE A DISTINCT POSSIBILITY. && .APX WATCHES/WARNINGS/ADVISORIES... MI...WINTER WEATHER ADVISORY FROM 1 AM TO 3 PM EST WEDNESDAY FOR MIZ019>036-041-042. WINTER STORM WARNING FROM 7 AM WEDNESDAY TO 5 AM EST THURSDAY FOR MIZ008-015. WINTER STORM WARNING FROM 4 AM WEDNESDAY TO 5 AM EST THURSDAY FOR MIZ016>018. LH...SMALL CRAFT ADVISORY FROM 1 AM TO 11 PM EST WEDNESDAY FOR LHZ349. GALE WARNING FROM 1 AM TO 11 PM EST WEDNESDAY FOR LHZ345>348. LM...GALE WARNING FROM 1 AM TO 11 PM EST WEDNESDAY FOR LMZ341-342. GALE WARNING FROM 1 AM TO 5 PM EST WEDNESDAY FOR LMZ323-344>346. LS...NONE. && $$ SYNOPSIS...TL SHORT TERM...ARNOTT LONG TERM....SMD AVIATION...BS MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
300 PM CST TUE FEB 28 2012 .DISCUSSION... WHAT A DIFFERENCE ABOUT 125 MILES MAKES... WHICH IS ROUGHLY THE DIFFERENCE IN WHERE THIS SYSTEM LOOKS TO BE TRACKING VS HOW IT APPEARED TWO DAYS AGO. OVERALL... THIS MEANS THE FORECAST IS PRETTY SIMILAR TO WHAT HAS BEEN EXPECTED... EXCEPT EVERYTHING HAS BEEN SHIFTED BY ABOUT THAT DISTANCE NORTHWARD. THERE WILL BE SOME ADDITIONAL CHANGES FORTHCOMING IN TERMS OF THE HEADLINES AND SNOWFALL EXPECTATIONS... AS WELL AS THE NORTHWARD EXTENT OF MIXED PRECIPITATION. LATEST WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSES SHOW OUR SYSTEM FINALLY BEGINNING TO EMERGE FROM THE SOUTHERN ROCKIES... WITH THE SURFACE LOW LOCATED NEAR THE INTERSECTION OF COLORADO... NEBRASKA... AND KANSAS. THE GUIDANCE IS... FINALLY... IN EXCELLENT AGREEMENT ON THE TIMING AND MOVEMENT OF THIS SYSTEM... TAKING THE SURFACE LOW NORTHEAST INTO SOUTHERN MINNESOTA BY 12Z WEDNESDAY... THEN VERY NEAR THE TWIN CITIES BY 18Z... BEFORE MOVING OFF TO THE GREAT LAKES WEDNESDAY NIGHT. SOME DIFFERENCES DO REMAIN IN THE GUIDANCE IN TERMS OF EXACTLY HOW WARM THE ELEVATED WARM LAYER WILL GET... AS WELL AS THE NEAR SURFACE TEMPERATURES AND NORTHWARD EXTENT OF THE WARMER TEMPERATURES. OVERALL... IT NOW LOOKS LIKE WE SHOULD GET SOME DEGREE OF MIXED PRECIPITATION OVER ALL BUT PERHAPS THE FAR NORTHERN PART OF THE AREA FOR A TIME TONIGHT. THE SOUTHERN CWFA HAS ALREADY TRANSITIONED TO SLEET OR RAIN... AND THIS WILL CONTINUE TO PUSH NORTH THROUGH THE EVENING. BASED THE FORECAST DETAILS ON A BLEND OF GFS... NAM... AND SREF GUIDANCE... BUT WITH A BIT OF WEIGHT ON THE RUC DURING THE FIRST 12 HOURS. ALSO LIKE THE GENERAL LOOK OF THE HRRR PRECIPITATION/REFLECTIVITY FIELDS THROUGH THIS EVENING... SO TOOK THAT INTO ACCOUNT. AS MENTIONED... EXPECT TO SEE THE MIXED PRECIPITATION PUSH NORTH THROUGH THIS EVENING AS THE STRONG LOW LEVEL JET PERSIST AHEAD OF THE SURFACE LOW. SUFFICIENTLY WARM TEMPERATURES AROUND 850-825MB LOOK TO GET AS FAR NORTH AS KAXN... BRINGING SOME CHANCE OF AT LEAST ICE PELLETS INTO THE FAR NORTHERN PART OF THE FORECAST AREA. A BRIEF WINDOW OF FREEZING RAIN STILL SEEMS POSSIBLE DURING THE TRANSITION FROM SLEET TO RAIN WHICH WILL OCCUR OVER THE CENTRAL AND SOUTHERN PART OF THE CWFA... ALTHOUGH OBSERVATIONS AND FORECAST PROFILES SUGGEST THAT ANY FZRA SHOULD BE SHORT-LIVED WITH THINGS PRIMARILY GOING FROM SLEET TO RAIN OVER NEARLY THE SOUTHERN HALF OF THE AREA BY EARLY THIS EVENING. AS THE SYSTEM OCCLUDES LATER TONIGHT AND WEDNESDAY MORNING AND BEGINS DRIFTING EAST WE SHOULD SEE THINGS COOL DOWN ONCE AGAIN... WITH THE WARM TONGUE ERODING FROM 09Z-15Z... CHANGING THE PCPN ASSOCIATED THE UPPER TROUGH BACK TO SNOW FOR THE DAY ON WEDNESDAY. PRIOR TO THEN... IT STILL APPEARS THAT WE WILL HAVE HEAVY PCPN TONIGHT... FALLING AS SNOW AND SLEET OVER THE NORTH... SLEET AND RAIN OVER THE CENTRAL... AND RAIN OVER THE SOUTH. HOWEVER... THE SOUTHERN PART OF THE AREA SHOULD ALSO SEE THE DRY SLOT WORK IN... WHICH WILL END HEAVIER PCPN IN THAT AREA TONIGHT. THERE IS SOME POSSIBILITY FOR SOME CONVECTION TO DEVELOP IN THE DRY WEDGE... MAINLY TO OUR SOUTH... BUT SOME ISOLATED THUNDER COULD GET UP INTO THE SOUTHERN PART OF THE CWFA THIS EVENING INTO THE OVERNIGHT HOURS. IN THE NORTH... WHERE THE PERSISTENT MODERATE TO HEAVY PCPN IS EXPECTED TO OCCUR... SIGNIFICANT SNOWFALL ACCUMULATIONS STILL APPEAR LIKELY... ALTHOUGH THEY MAY BE TEMPERED TO SOME DEGREE BY MIXING WITH SLEET. STRONG MID-LEVEL FRONTOGENESIS... AND COUPLING WITH THE UPPER JET CIRCULATION... STILL APPEAR TO BE IN PLACE FOR A TIME TONIGHT... ALONG WITH NEGATIVE EPV NEAR AND ABOVE THAT LAYER OF FORCING. OVER THE SOUTHERN PART OF THE AREA... THAT INSTABILITY IS UPRIGHT GIVEN NEGATIVE DIFFERENTIAL THETA-E WHICH WILL BE IN PLACE... BUT AS YOU GO NORTH THINGS SUGGEST IT WOULD BE MORE SYMMETRIC IN NATURE. THAT WOULD SUGGEST MORE OF A CELLULAR PCPN LOOK ON THE SOUTH END OF THINGS AS THEY PUSH NORTH LATER TONIGHT... WITH MORE IN THE WAY OF BANDING FARTHER NORTH. PCPN WILL LINGER THROUGH MUCH OF THE DAY ON WEDNESDAY AS THE UPPER TROUGH SLOWLY PUSHES ACROSS THE AREA AND ABUNDANT DEEP LAYER MOISTURE PERSISTS. SOME MIXED PCPN MAY STILL BE POSSIBLE IN THE MORNING OVER THE SOUTHEAST PORTION OF THE AREA... BUT BY LATE MORNING ANY REMAINING PCPN SHOULD BE IN THE FORM OF SNOW... WITH SOME ADDITIONAL ACCUMULATIONS STILL EXPECTED... PARTICULARLY OVER THE NORTH CENTRAL AND NORTHEAST CWFA. VERY WEAK RIDGING LOOKS TO WORK INTO THE AREA WEDNESDAY NIGHT... BRINGING AN END THE PCPN... BUT A WEAK NORTHERN STREAM SHORTWAVE MAY BRING A CHANCE OF SNOW BACK INTO THE NORTHERN CWFA ON THURSDAY. THE NEXT FEATURE OF ANY CONCERN STILL LOOKS LIKE IT WILL BE MOVING NEAR THE AREA ON FRIDAY... BUT THE LATEST GUIDANCE CONTINUES THE IDEA OF KEEPING THAT SYSTEM OFF TO OUR SOUTHEAST. WITH THE AFOREMENTIONED NORTHERN STREAM UPPER TROUGH STILL IN THE VICINITY THROUGH FRIDAY... AND THE SOUTHERN WAVE PASSING BY TO OUR SOUTHEAST... DID CARRY SOME LOW POPS OVER MUCH OF THE AREA ON FRIDAY... BUT AT THIS POINT IT DOES NOT APPEAR IT WILL BE MUCH OF AN ISSUE FOR OUR AREA. THE WEEKEND INTO EARLY NEXT WEEK LOOK TO BE MAINLY DRY... ALTHOUGH THERE COULD BE SOME FLURRIES AROUND OVER THE WEEKEND WITH CYCLONIC FLOW AND FAIRLY STEEP BOUNDARY LAYER LAPSE RATES IN PLACE. DIDN/T INCLUDE MUCH IN THE WAY OF PCPN MENTION AT THIS POINT... BUT WOULDN/T BE SURPRISED TO EVENTUALLY NEED TO INCLUDE SOME SNOW SHOWERS AND/OR FLURRIES FOR SATURDAY INTO SUNDAY. THE START OF NEXT WEEK SHOULD SEE A SIGNIFICANT WARM UP ACROSS THE AREA AS HEIGHTS BUILD... AND 1000-500MB THICKNESS VALUES CLIMB WELL ABOVE 555DM. INCLUDED HIGHS OF NEAR 50 DEGREES BY TUESDAY... WHICH CERTAINLY DOESN/T LOOK UNREASONABLE AT THIS POINT SHOULD THINGS WARM AS SUGGESTED. && .AVIATION.../00Z TAF ISSUANCE/ WITH THIS WARM SURGE...INCLUDED A MIX OF SLEET AND/OR RAIN IN ALL THE TAFS. IFR CEILINGS LOOK LIKELY EVERYWHERE BY 00Z OR SO THIS EVENING. THE VIS RESTRICTION MAY NOT BE ALL THAT BAD WITH THE PRECIPITATION TYPE GOING FROM SNOW TO A MIX. LOCATIONS SUCH AS KMSP...KRNH...KEAU...WILL SEE A SNOW/SLEET MIXTURE TRANSITION TO SLEET/RAIN OVER THE NEXT 6 HOURS...SO BY AROUND 00Z. THE SLEET ACCUMULATION COULD CAUSE POTENTIAL PROBLEMS LATE THIS AFTERNOON AND EARLY THIS EVENING. KRWF...WILL BE NEARLY ALL RAIN FOR THE NEXT 12-15 HOURS. THE PRECIP SHOULD CHANGE BACK OVER SNOW LATE TONIGHT AND TOMORROW MORNING FROM NORTHWEST TO SOUTHEAST. KMSP...SNOW WILL BEGIN TO MIX WITH SLEET OVER THE NEXT 2-3 HOURS AND THEN TRANSITION TO A SLEET AND RAIN MIXTURE EARLY THIS EVENING. VIS WILL REMAIN VFR/MVFR...BUT CEILINGS WILL DROP TO IFR BY THIS EVENING. SNOW CHANGE OVER BACK TO SNOW WILL BE SNOW TONIGHT AND MIGHT BE CLOSE TO SUNRISE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR BROWN- CARVER-DAKOTA-GOODHUE-HENNEPIN-LE SUEUR-MCLEOD-NICOLLET- REDWOOD-RENVILLE-RICE-SCOTT-SIBLEY-YELLOW MEDICINE. WINTER STORM WARNING UNTIL 6 PM CST WEDNESDAY FOR ANOKA-BENTON- DOUGLAS-MORRISON-POPE-SHERBURNE-STEARNS-STEVENS-SWIFT-TODD. WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST WEDNESDAY FOR CHISAGO-ISANTI-KANABEC-MILLE LACS. WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR RAMSEY- WASHINGTON. WINTER STORM WARNING UNTIL 6 PM CST WEDNESDAY FOR CHIPPEWA- KANDIYOHI-LAC QUI PARLE-MEEKER-WRIGHT. WI...WINTER STORM WARNING UNTIL 6 PM CST WEDNESDAY FOR CHIPPEWA. WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST WEDNESDAY FOR BARRON-POLK-RUSK. WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR DUNN-EAU CLAIRE-PEPIN-PIERCE-ST. CROIX. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
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
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
221 PM CST TUE FEB 28 2012 .SHORT TERM...TONIGHT AND WEDNESDAY. LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY INDICATES LOW PRESSURE EMERGING FROM THE ROCKIES INTO WESTERN KANSAS THIS AFTERNOON...WITH ITS ASSOCIATED WARM FRONT LIFTING NORTH ALONG THE KS/NE BORDER AND ACROSS MISSOURI. CONVECTION HAS DEVELOPED ALREADY AHEAD OF THE LOW JUST AHEAD OF A POTENT DRY SLOT PUNCHING INTO NEBRASKA. CLOSER TO HOME...LEADING EDGE OF RETURN MOISTURE IS NOW PUSHING INTO SOUTHERN WISCONSIN A TAD AHEAD OF SCHEDULE...AS EVIDENT BY A BAND OF RAIN AND SNOW. EARLIER MODERATE SNOW OVER N-C WISCONSIN IS HANGING ON ALONG THE U.P. BORDER WHERE THEY RECEIVED 2-3 INCHES OF SNOW. BUT THE MAIN PROBLEM FOR THIS FORECAST IS THE LOW OUT WEST AND HEAVY SNOW POTENTIAL AS IT MOVES ACROSS THE REGION TONIGHT INTO WEDNESDAY. TONIGHT...LOW PRESSURE OVER THE PLAINS WILL MOVE NORTHEAST AND OCCLUDE AS IT MOVES INTO SOUTHWEST MINNESOTA BY 12Z WEDNESDAY. AHEAD OF THE LOW...A 40-50KT LLJ WILL RAMP UP AND SHIFT INTO NORTHERN ILLINOIS DURING THE OVERNIGHT HOURS. THIS LLJ WILL TRANSPORT RICH GULF OF MEXICO MOISTURE NORTHEAST WITH PWATS OF UPWARDS OF 0.75 INCHES REACHING INTO CENTRAL WISCONSIN. THIS IS OVER 200 PCT OF NORMAL AND 2 STANDARD DEVIATIONS ABOVE NORMAL. BEFORE THIS OCCURS THOUGH...LEADING EDGE OF THE RETURN MOISTURE ON THE 285K SURFACE IS CREATING A BAND OF LIGHT RAIN AND SNOW WHICH SHOULD APPROACH CENTRAL WISCONSIN LATE THIS AFTERNOON AND INTO THE FOX VALLEY BY EARLY IN THE EVENING. WET BULB TEMPS HAVE BEEN RISING THIS AFTERNOON...BUT FIGURING SNOW OVER CENTRAL WISCONSIN...AND RAIN/SNOW MIX OVER EAST-CENTRAL WHERE ONSHORE FLOW WILL CONTINUE. THE MAIN SURGE OF PRECIPITATION SHOULD NOT ARRIVE UNTIL LATE INTO THE EVENING AND THE OVERNIGHT HOURS WHEN FORCING VIA LLJ AND MID-LEVEL FGEN LIFTS INTO THE REGION. WITH MID-LEVEL LAPSE RATES OF 6.5-7 C/KM AND NEGATIVE EPV ABOVE THE FGEN LAYER...CONVECTION IS DEFINITELY POSSIBLE WITH THE PRECIPITATION OVERNIGHT...AND UPSTREAM OBS BEAR THIS OUT AS WELL. THERMAL PROFILES VARY WIDELY BETWEEN THE WARMER GFS AND THE COLDER ECMWF/NAM. ALTHOUGH THERE IS PLENTY OF WARM AIR TO OUR SOUTH...THE WARM LAYER IS MARGINALLY HIGH AT AROUND 800MB WHICH LEAVES THE POTENTIAL FOR CONVECTION TO WIPE OUT THAT WARM NOSE...THEREBY KEEPING THE PROFILE NEAR OR JUST BELOW FREEZING OVER CENTRAL AND EAST-CENTRAL WISCONSIN. AS A RESULT...HAVE BOOSTED SNOW AMOUNTS OVER CENTRAL WISCONSIN AND THE NORTHERN FOX VALLEY. AM MOST CONFIDENT OF RAIN/SLEET MIXING IN OVER KEWAUNEE AND MANITOWOC COUNTIES THANKS TO THE LAKE INFLUENCE. SE WINDS WILL ALSO RAMP UP OVERNIGHT WHICH COULD CREATE NEAR WHITE OUT VSBYS AT TIMES WITHIN THE HEAVY SNOW. WILL UPGRADE DOOR COUNTY TO WARNING CRITERIA...AS THEY DO SURPRISINGLY WELL IN CASES LIKE THIS...WHERE COLDER AIR AT 925MB WILL HANG ON THE LONGEST. OTHERWISE...CURRENT HEADLINES LOOK GOOD FOR WARNING/ADVISORY CONFIGURATION. THE NEXT SHIFT WILL HAVE TO MONITOR FOR UPGRADES FOR THE NEXT ROW OF COUNTIES SOUTH OF THE WARNING IF CONVECTION DOES COOL THE COLUMN ENOUGH FOR A MOSTLY SNOW PTYPE. WEDNESDAY...OCCLUDED LOW PRESSURE WILL SLOW AND MOVE FROM SW MINNESOTA TO WESTERN WISCONSIN OVER THE COURSE OF THE DAY. LOW LEVEL WARM AIR WILL CONTINUE TO WRAP AROUND THE LOW INTO EASTERN WISCONSIN DURING THE MORNING...WHILE THE DRY SLOW MOVES IN ALOFT. MODERATE TO HEAVY SNOW WILL BE WIDESPREAD NORTH AND WEST OF THE DRY SLOT OVER NORTHERN AND NORTHWEST WISCONSIN FOR MUCH OF THE MORNING. BUT FARTHER SOUTH...THE DRY SLOT WILL MAKE IT DIFFICULT FOR ICE CRYSTALS TO GET INTRODUCED INTO THE CLOUD...SO HAVE ADDED THE CHANCE OF FREEZING DRIZZLE OVER CENTRAL AND PARTS OF NORTHEAST WISCONSIN. RAIN OR DRIZZLE SHOULD BE MIXING WITH SNOW BY THE TIME OF THE MORNING COMMUTE OVER THE FOX VALLEY AND LAKESHORE WHICH LOOKS TO BE A SLOPPY MESS. SHOULD ALSO SEE A PERIOD OF OF JUST RAIN/DRIZZLE AS WELL...MID-MORNING THROUGH MID-AFTERNOON BEFORE COLDER AIR SURGES EAST AS IT WRAPS AROUND THE LOW. WITH ALL THIS IN MIND...TOTAL SNOWFALL ACCUMULATION THROUGH 00Z THU LOOKS LIKE 10-15 INCHES OVER N-C WISCONSIN...6-10 NORTH OF A MARSHFIELD TO STURGEON BAY LINE...AND 3-7 INCHES FOR CENTRAL WISCONSIN AND MUCH OF THE FOX VALLEY. DID END HEADLINES EARLY FOR THE FOX VALLEY AND LAKESHORE...AS SNOW CHANGING TO RAIN SHOULD CAUSE CONDITIONS TO RAPIDLY IMPROVE BY 18Z WED. .LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. PERIOD TO SEE SHIFT FROM OUR SPLIT FLOW PATTERN TO A MORE CONSOLIDATED FLOW WITH TROF SHIFTING EAST THROUGH THE LAKES REGION THIS WEEKEND. TEMPS FOR SAT AND SUN EXPECTED TO BE AOB NORMS. RIDGE TO FOLLOW FOR MUCH OF THE WORK WEEK FOR A DRY AND MILD PERIOD. WED NIGHT TO THU...STORM TO BE EXITING THE AREA WITH SNOW ENDING WEST TO EAST. LEFT OUT OF GRIDS AT THIS TIME...THOUGH MODEL SOUNDINGS INDICATE SOME FREEZING DRIZZLE POSSIBLE OVER THE EAST BEHIND SYSTEM. WEAK HIGH PRESSURE MOVES THROUGH DURING DAY THU...SMALL CHANCE OF LAKE EFFECT FAR NW VILAS IN THE MORNING THOUGH SUPPORT FOR THAT WEAKENS BY AFTERNOON. THU NIGHT TO FRIDAY...MODELS STILL HAVING DIFFICULTY THIS PERIOD...THOUGH STARTING TO GEL A BIT. TROF OF LOW PRESSURE/DEVELOPING COLD FRONT MOVES EAST INTO STATE LATE THU NIGHT. SIG WAA AHEAD OF SYSTEM AND SOME FGEN SAYS KEEP SMALL POPS...MAINLY NORTH...UPPER SUPPORT WEAK THOUGH. ALL MODELS WANT TO DEVELOP WAVE ON FRONT SOUTH OF STATE...BRING IT NE ALONG FRONT. MOST TO OUR EAST...THOUGH GFS REMAINS CONSISTENT BRINGING LOW THROUGH STATE. EITHER WAY KEPT CHANCE POPS HIGHEST EAST. SOME CONCERN WITH PCPN TYPE...WILL GO FOR MIX EAST...THOUGH LATEST EC BRINGING COLDER AIR FURTHER EAST. WEEKEND...HINTS AT POSSIBLE CLIPPER SYSTEM SUN...AND POSSIBLE LAKE EFFECT FAR NORTHWEST CWA WITH NORTHWEST FLOW. && .AVIATION...LIGHT SNOW WITH IFR VSBYS WILL BE DIMINISHING THIS AFTERNOON OVER N-C WISCONSIN WHILE THE REST OF THE AREA WILL BE VFR. THEN LOW PRESSURE WILL DEEPEN AS IT MOVES ACROSS THE PLAINS TONIGHT. A WARM FRONT WILL LIFT NE INTO THE NORTHERN MISSISSIPPI VALLEY AND PROVIDE THE FOCUS FOR THE ARRIVAL OF HEAVY SNOW. DRY AIR WILL ERODE THE SNOW AS IT ARRIVES OVER NE WISCONSIN...BUT WILL BRING IN THE SNOW INTO N-C WISCONSIN BY MID-EVENING...AND INTO THE FOX VALLEY BY LATE EVENING. MODERATE TO HEAVY SNOW WILL CONTINUE THROUGH MUCH OF THE NIGHT ONCE IT ARRIVES. WARMER TEMPERATURES ALOFT WILL ARRIVE BY LATE TONIGHT INTO WEDNESDAY MORNING...WHICH SHOULD CAUSE SLEET AND FREEZING DRIZZLE TO MIX IN OVER CENTRAL AND EAST-CENTRAL WISCONSIN THROUGH MIDDAY. WARMER AIR ARRIVES AT THE SURFACE OVER E-C WISCONSIN IN THE MORNING...WHICH SHOULD LEAD TO IMPROVING CONDITIONS. MPC && .GRB WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST WEDNESDAY FOR WIZ038>040-048>050. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST WEDNESDAY FOR WIZ035>037-045. WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST WEDNESDAY FOR WIZ005-010-011-018>020-030-031. WINTER STORM WARNING FROM 9 PM THIS EVENING TO 6 PM CST WEDNESDAY FOR WIZ012-013-021-073-074. WINTER STORM WARNING FROM 9 PM THIS EVENING TO NOON CST WEDNESDAY FOR WIZ022. && $$ MPC/TE