Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/29/13


AREA FORECAST DISCUSSION
NWS TUCSON AZ
845 PM MST THU MAR 28 2013 .SYNOPSIS...DRY AND WARM THROUGH THE WEEKEND. A LOW PRESSURE SYSTEM SKIRTING BY NORTHEAST OF THE AREA WILL BRING GUSTY WINDS AND A FEW DEGREES OF COOLING EARLY NEXT WEEK. && .DISCUSSION...PATCHY MID AND HIGH CLOUD OVERNIGHT IN A MODEST WESTERLY FLOW ON THE BACK SIDE OF A LOW AMPLITUDE DIRTY RIDGE. SOME ADJUSTMENTS TO ENHANCE FIRST PERIOD CLOUD COVER AND SHOW MORE OF A BREAK IN SOME AREAS FRIDAY AS WE MAY MANAGE A DECENT BREAK IN CLOUD COVER TOMORROW BEFORE KICKING IN ANOTHER THICK PATCH TOMORROW NIGHT. OTHERWISE CURRENT FORECAST PACKAGE HAS GOOD TRENDS. NO SURPRISES IN EARLY LOOKS AT 00Z MODEL DATA OR LATEST HRRR TRENDS. && .PREV DISCUSSION...A LARGE LOW PRESSURE SYSTEM CENTERED WELL OFF THE CALIFORNIA COAST TODAY CONTINUED TO PROVIDE A STREAM OF HIGH LEVEL CLOUDS OVER THE REGION. SOME INCREASE IN MID LEVEL MOISTURE COMBINED WITH SURFACE HEATING HAD ALSO RESULTED IN SCATTERED FAIR WEATHER CUMULUS CLOUDS TODAY. MODELS SHOWED VERY LITTLE CHANGE IN THE WEATHER PATTERN THROUGH ABOUT SUNDAY...SO JUST EXPECTING MORE OF THE SAME WITH VARIABLE HIGH CLOUDINESS AND SIMILAR TEMPERATURES. EVENTUALLY...MODELS SHOWED THE LOW PRESSURE SYSTEM OFF THE CALIFORNIA COAST TODAY MOVING INLAND ON SUNDAY. THEREAFTER...MEDIUM RANGE MODELS DIFFERED A BIT ON THE TRACK AND STRENGTH OF THE SYSTEM MONDAY INTO WEDNESDAY. LATEST GFS AND ECMWF MODELS WERE IN A LITTLE BETTER AGREEMENT WITH KEEPING THE BULK OF THE SYSTEM AND SUBSEQUENT PRECIPITATION CHANCES NORTH OF THE AREA MONDAY AND TUESDAY AS IT WEAKENS AND BRUSHES NORTHERN ARIZONA. THE MAIN INFLUENCE OF THE SYSTEM ON SOUTHERN ARIZONA WILL BE AN INCREASE IN WIND AND A SLIGHT DROP IN DAY TIME TEMPERATURES. && .AVIATION...SCT-BKN CLOUDS MAINLY ABOVE 10K-15K FT AGL WILL PREVAIL THROUGH MID FRIDAY MORNING OR 29/15Z WITH PARTIAL CLEARING FROM THE WEST DURING THE DAY FRIDAY. DIURNAL SURFACE WIND LESS THAN 8 KTS INTO FRIDAY MORNING...THEN WESTERLY 10-15 KTS AND GUSTY AT TIMES AFTER 29/19Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH SUNDAY. NORMAL DIURNAL WIND TRENDS ARE EXPECTED INTO THE WEEKEND...WITH OCCASIONAL GUSTS DURING THE AFTERNOON HOURS DUE TO DAYTIME HEATING. A WEAKENING LOW PRESSURE SYSTEM WILL MOVE NORTH OF THE AREA MONDAY THROUGH TUESDAY. THIS SYSTEM WILL BRING A COOLING TREND AS WELL AS SOME BREEZINESS MAINLY DURING THE AFTERNOON HOURS. THERE IS ALSO A SLIGHT CHANCE OF SHOWERS ACROSS THE WHITE MOUNTAINS TUESDAY. DRY CONDITIONS WITH ANOTHER WARMING TREND NEXT WEDNESDAY. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS POCATELLO ID
203 PM MDT WED MAR 27 2013 .SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT. A LOW PRESSURE SYSTEM OFF OF THE COAST OF OREGON IS SPREADING MOISTURE THROUGH THE REGION. A FEW SHOWERS ARE POSSIBLE TONIGHT. ANOTHER LOW PRESSURE SYSTEM WEST OF THE OREGON SYSTEM WILL DROP SOUTH THROUGH THE PERIOD. THE OREGON LOW WILL WEAKEN AND BECOME ABSORBED BY THE SECOND LOW PRESSURE SYSTEM. DURING THIS TIME...MOISTURE WILL CONTINUE TO SPREAD THROUGH THE AREA. ISOLATED SHOWERS WILL REMAIN POSSIBLE FOR THE REMAINDER OF THE WEEK. ENOUGH INSTABILITY MAY DEVELOP ON THURSDAY TO PRODUCE A FEW ISOLATED THUNDERSTORMS. A COLD FRONT WILL ARRIVE FRIDAY. THE FRONT WILL INCREASE THE AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS. TEMPS WILL BE ABOVE AVERAGE FOR THE REMAINDER OF THE WEEK BECAUSE OF SOUTHERLY FLOW OVER THE REGION. VALLE .LONG TERM...SATURDAY THROUGH WEDNESDAY. FOCUS IS ON THE EVOLUTION AND TRAJECTORY OF UPPER LOW EXPECTED TO MAKE LANDFALL LATE SUNDAY NIGHT. GFS CONTINUES TO DROP THE LOW FURTHER SOUTH INTO ARIZONA WHILE THE ECMWF MAINTAINS A WEAKER CIRCULATION...BUT MOVES THE LOW ACROSS CENTRAL UTAH. THE ECMWF SOLUTION IS THEREFORE THE WETTER ONE FOR SOUTHEAST IDAHO...HOWEVER IT IS MORE PROGRESSIVE WITH THE UPPER FEATURE. KEPT THE FOCUS OF POPS OVER THE SOUTHERN HIGHLANDS AND WILL CONTINUE TO MONITOR TRENDS IN BOTH MODELS AS WE HEAD INTO THE WEEKEND. UPPER RIDGING WILL BUILD INTO THE AREA TUESDAY AS TEMPERATURES WARM THROUGH WEDNESDAY. MODELS ARE A BIT UNCERTAIN AS TO THE INTENSITY OF UPPER RIDGING OVER THE WEST ON WEDNESDAY. GFS HAS A WEAK SHORTWAVE TROUGH IN THE NORTHWESTERLY FLOW DROPPING OUT OF ALBERTA. THE ECMWF RUN YESTERDAY SHOWED THIS TO BE A MORE SIGNIFICANT FEATURE...BUT TODAY KEEPS THE SYSTEM NORTH OF THE CANADIAN BORDER. HINSBERGER && .AVIATION...VIS IMAGERY SHOWING CLOUD FIELD OVER SOUTHEAST IDAHO GRADUALLY LIFTING NORTHEAST. RESULTING HEATING COULD DECREASE STABILITY OVER THE SNAKE PLAIN MEANING POTENTIAL FOR SHOWERS. INDEED THE HRRR HINTS AT SHOWERS DEVELOPING THIS AFTERNOON. TERMINALS SHOULD REMAIN VFR THROUGH THE PERIOD. HINSBERGER && .PIH WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
251 PM CDT WED MAR 27 2013 .DISCUSSION... ISSUED 250 PM CDT WED MAR 27 2013 UPPER NORTHWEST FLOW WILL PERSIST THROUGH MUCH OF THE FORECAST VALID PERIOD. BIGGEST DIFFERENCES IN 12Z MODEL SUITES INVOLVE THE STRENGTH OF WAVES IN NW FLOW AND THE RESULTANT ARCTIC AIR SURGES OVER THE NEXT SEVEN DAYS. SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT SFC RIDGE OVER MISSISSIPPI RIVER VALLEY WILL PUSH ONLY SLOWLY EAST OVER THE NEXT 24 HOURS. ALTHOUGH...LATE MARCH SUNSHINE TODAY CONTINUES TO PUT A MAJOR DENT IN SNOW COVER...LIGHT WINDS AND CLEAR SKIES UNDER THE RIDGE SHOULD ALLOW TEMPS TO FALL WELL BELOW NORMAL. KSPI RECORD IS 14F TONIGHT. WILL PROBABLY NOT SEE THE MERCURY DIP THAT LOW...BUT SOME TEENS ARE LIKELY IN LOW SPOTS THAT RETAIN WIDESPREAD SNOW COVER. SURFACE RIDGE SHOULD REACH APPALACHIANS BY LATE FRIDAY NIGHT ALLOWING SOME WAA TO PUSH INTO ILLINOIS. CLOUDS SHOULD TEMPER WARMING SOMEWHAT...BUT HIGHS SHOULD CLIMB SEVERAL DEGREES EACH DAY...REACHING UPPER 40S TO LOWER 50S. NORMAL THIS TIME OF YEAR IS MOSTLY UPPER 50S. LONG TERM...SATURDAY THROUGH WEDNESDAY COLD AIR CURRENTLY POOLING OVER ALASKA...CURRENTLY 20-30 DEGREES BLO NORMAL...IS PROGGED TO GET CAUGHT IN GENERAL NORTHWEST FLOW AND SPILL DOWN INTO MIDWEST BY SUNDAY NIGHT. AHEAD OF THE COLDEST AIR...SEVERAL SURGES WILL PUSH ACROSS ILLINOIS BEGINNING SATURDAY...EACH COLDER. THE INITIAL FRONT ON SATURDAY AFTERNOON/EVENING SHOULD INTERACT WITH GULF MOISTURE TO PRODUCE GOOD CHANCE/LIKELY POPS. INSTABILITY AXIS REMAINS TO OUR WEST AND REACHES ILLINOIS AFTER SUNSET...SO WITH CURRENT TIMING THUNDER NOT EXPECTED...BUT LATER SHIFTS WILL NEED TO MONITOR. FINAL SURGE ON SUNDAY NIGHT BRINGS UNSEASONABLY COLD 850 TEMPS... AROUND -10C...BACK INTO ILLINOIS. WOULD NOT BE SURPRISED TO SEE SOME SNOW MIXED IN WITH ANY LIGHT PRECIP ACCOMPANYING THIS FRONT LATE SUNDAY NIGHT OR MONDAY MORNING. HOWEVER...MOISTURE SHOULD BE VERY LIMITED GIVEN THAT THE FIRST FRONT IS EXPECTED TO SHUNT THE GULF MOISTURE EAST WELL BEFORE THE COLD AIR ARRIVES. BY MONDAY 12Z...850 TEMPS ARE EXPECTED TO HAVE DROPPED 15-20C IN APPROXIMATELY 24 HOURS. CURRENTLY HOLDING ON TO 40S FOR MONDAY AND TUESDAYS HIGHS...BUT THE RUN-TO-RUN TREND HAS BEEN GOING COLDER. THE 00Z ECMWF HAD BEEN A BIT WARMER THAN THE GFS AND GEFS MEAN...BUT THE 12Z ECMWF IS NOW ALSO TAPPING THE COLD AIR AND PLUNGING A 5100 M 500 MB LOW INTO ONTARIO SIMILAR TO THE GFS BY MONDAY SUGGESTING THAT HIGHS MAY REMAIN IN THE 30S ACROSS CENTRAL ILLINOIS FOR THE FIRST FEW DAYS OF APRIL. BARKER && .AVIATION... ISSUED 1247 PM CDT WED MAR 27 2013 VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS AT ALL OF THE TAF SITES IN CENTRAL AND EASTERN IL. A RIDGE OF HIGH PRESSURE ALONG THE MS RIVER VALLEY WILL SLOWLY DRIFT INTO CENTRAL IL TONIGHT AND THURSDAY MORNING RESULTING IN LIGHT AND MAINLY VARIABLE WIND. LOW LEVEL MOISTURE FIELDS IN THE RUC AND HRRR MODELS...ALONG WITH STEEPER LAPSE RATES HAS RESULTED IN THE DEVELOPMENT OF CUMULUS IN PARTS OF CENTRAL IL EARLY THIS AFTERNOON. THIS DIURNAL CLOUDINESS WILL RESULT IN BROKEN VFR CIGS UNTIL DUSK. THE EXCEPTION WILL BE WHERE THE DEEPEST SNOW PACK IS LOCATED...NEAR KSPI...WHERE LESS HEATING WILL RESULT IN FEWER CLOUDS. LOW AND MID LEVEL WARM ADVECTION WILL RESULT IN INCREASING CLOUDS AROUND 10KFT THURSDAY MORNING...PARTICULARLY IN SW IL EARLY IN THE DAY...AND THEN INTO CENTRAL IL LATE IN THE MORNING. KEPT THE CLOUD COVER TO A MINIMUM IN EASTERN IL DUE TO CONTINUED SUBSIDENCE IN THE MORNING AND WARM ADVECTION HOLDING OFF UNTIL AFTERNOON AND LATER. MILLER && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1246 PM CDT WED MAR 27 2013 .DISCUSSION... ISSUED 1106 AM CDT WED MAR 27 2013 NO CHANGES WILL BE MADE TO THE CURRENT FORECAST...ONLY MINOR TWEAKS TO SOME OF HOURLY GRIDS FOR THIS AFTERNOON. SATELLITE INDICATED THAT MOST AREAS OF CENTRAL AND SE IL HAVE CLEARED... EXCEPT IN FAR EASTERN IL AND FAR SE IL. THE RUC AND HRRR MODELS BOTH INDICATE THAT CU IS EXPECTED TO FORM BY EARLY THIS AFTERNOON. THE LAPSE RATES AND CONVECTIVE TEMP ON THE 12Z ILX SOUNDING INDICATE THAT READINGS CLOSE TO 40 SHOULD RESULT IN CU FORMING...SO PARTLY SUNNY LOOKS GOOD IN THE FORECAST FOR MOST LOCATIONS. LINGERING SNOW COVER WILL KEEP HIGH TEMPS CLOSE TO 40 DEGREES IN CENTRAL IL WITH MID 40S SOUTH OF I-70. MILLER && .AVIATION... ISSUED 1247 PM CDT WED MAR 27 2013 VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS AT ALL OF THE TAF SITES IN CENTRAL AND EASTERN IL. A RIDGE OF HIGH PRESSURE ALONG THE MS RIVER VALLEY WILL SLOWLY DRIFT INTO CENTRAL IL TONIGHT AND THURSDAY MORNING RESULTING IN LIGHT AND MAINLY VARIABLE WIND. LOW LEVEL MOISTURE FIELDS IN THE RUC AND HRRR MODELS...ALONG WITH STEEPER LAPSE RATES HAS RESULTED IN THE DEVELOPMENT OF CUMULUS IN PARTS OF CENTRAL IL EARLY THIS AFTERNOON. THIS DIURNAL CLOUDINESS WILL RESULT IN BROKEN VFR CIGS UNTIL DUSK. THE EXCEPTION WILL BE WHERE THE DEEPEST SNOW PACK IS LOCATED...NEAR KSPI...WHERE LESS HEATING WILL RESULT IN FEWER CLOUDS. LOW AND MID LEVEL WARM ADVECTION WILL RESULT IN INCREASING CLOUDS AROUND 10KFT THURSDAY MORNING...PARTICULARLY IN SW IL EARLY IN THE DAY...AND THEN INTO CENTRAL IL LATE IN THE MORNING. KEPT THE CLOUD COVER TO A MINIMUM IN EASTERN IL DUE TO CONTINUED SUBSIDENCE IN THE MORNING AND WARM ADVECTION HOLDING OFF UNTIL AFTERNOON AND LATER. MILLER && .PREV DISCUSSION... ISSUED 303 AM CDT WED MAR 27 2013 SHORT TERM...TODAY THROUGH FRIDAY LARGE AREAS OF STRATOCUMULUS ARE STILL AFFECTING THE CWA EARLY THIS MORNING WITH SOME BREAKS WORKING IN FROM THE NORTHEAST. FEEL THIS TREND WILL CONTINUE THROUGH MUCH OF THE MORNING. STEEP LOW LEVEL LAPSE RATES AND BOUNDARY LAYER MOISTURE FROM SNOW MELT WILL LIKELY LEAD TO RAPID REFORMING OF STRATOCU IN AREAS THAT DO CLEAR OUT FOR A TIME TODAY. OVERALL PARTLY SUNNY SKIES AND LIGHTER WINDS WITH SURFACE RIDGE AXIS MOVING IN. GRADUAL THERMAL MODERATION CONTINUES AND MOST AREAS SHOULD SEE HIGHS BREAK INTO THE 40S...STILL AROUND 15 DEGREES BELOW NORMAL. QUIET WEATHER WITH SLOW WARMING TREND THU/FRI AS THE RIDGE AXIS SLOWLY SHIFTS EAST INTO THE LOWER GREAT LAKES AND OHIO VALLEY. WILL NEED TO WATCH A WARM FRONT DEVELOPING OVER MO LATE THU AS MOST MODELS SHOWING ENOUGH LIFT AND SATURATION FOR LIGHT SHOWERS NEAR THIS FEATURE INTO FRIDAY. NAM IS ONLY OPERATIONAL MODEL SHOWING THIS ACTIVITY FAR ENOUGH EAST TO AFFECT THE SOUTHWEST CWA...WHILE ALL OTHER SOLUTIONS KEEP THE LOCAL AREA DRY AND WILL FOLLOW MODEL CONSENSUS FOR NOW. LONG TERM...SATURDAY THROUGH TUESDAY A POTENT MID LEVEL TROF DIVING THROUGH SOUTHERN CANADA WILL SEND TWO COLD FRONTS SOUTHEAST ACROSS THE MIDWEST THIS WEEKEND. RELATIVELY MILD AIR STILL EXPECTED TO OVERSPREAD THE AREA WITH HIGHS GETTING INTO AT LEAST THE LOWER 50S BOTH SATURDAY AND SUNDAY. RAIN SHOWERS WILL ACCOMPANY THE INITIAL FRONTAL PASSAGE WHICH WILL MOVE THROUGH THE CWA SATURDAY NIGHT/SUNDAY MORNING. HAVE RAISED POPS TO LIKELY ACROSS THE NORTH SATURDAY NIGHT WHERE BETTER DYNAMICS ASSOCIATED WITH THE MID LEVEL TROUGH WILL BE LOCATED. THIS LOOKS TO BE A LIGHT/MODERATE RAIN EVENT QPF OF .1-.5 INCHES. SOME TIMING DIFFERENCES NOTED IN THE 00Z SOLUTIONS WITH ECMWF NOW 6+ HOURS FASTER WITH FRONTAL PASSAGE WHILE GFS SLOWER SHOWING A SFC LOW DEVELOPING ALONG THE BOUNDARY. WILL BASE FORECAST ON MORE CONSISTENT SLOWER TIMING BUT MONITOR TRENDS CLOSELY ON NEXT COUPLE RUNS. A SIGNIFICANT AIRMASS CHANGE WILL OCCUR WITH A SECONDARY FRONTAL PASSAGE ON SUNDAY NIGHT. THIS WILL SEND TEMPS CRASHING WELL BELOW NORMAL FOR MONDAY AND TUESDAY...AS A CANADIAN HIGH BUILDS FROM THE PLAINS INTO THE UPPER MIDWEST. 850 MB TEMPS DIPPING INTO A -6 TO -10 C RANGE WILL SEND HIGHS INTO THE LOW/MID 40S AND LOWS INTO THE 20S FOR THE BEGINNING OF APRIL. A SERIES OF SOUTHERN STREAM WAVES WILL SHIFT EAST FROM THE PLAINS THROUGH THE TENNESSEE VALLEY LATE MONDAY THROUGH MID- WEEK SPREADING PRECIP BACK NORTH ACROSS THE SOUTHERN FLANK OF THE COLD AIRMASS. MOST MEDIUM RANGE MODELS/ENSEMBLES SUGGEST HIGH WILL BE STRONG ENOUGH TO KEEP THIS ACTIVITY SOUTH OF THE AREA AND WILL KEEP THE FORECAST DRY THROUGH TUESDAY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1107 AM CDT WED MAR 27 2013 .DISCUSSION... ISSUED 1106 AM CDT WED MAR 27 2013 NO CHANGES WILL BE MADE TO THE CURRENT FORECAST...ONLY MINOR TWEAKS TO SOME OF HOURLY GRIDS FOR THIS AFTERNOON. SATELLITE INDICATED THAT MOST AREAS OF CENTRAL AND SE IL HAVE CLEARED... EXCEPT IN FAR EASTERN IL AND FAR SE IL. THE RUC AND HRRR MODELS BOTH INDICATE THAT CU IS EXPECTED TO FORM BY EARLY THIS AFTERNOON. THE LAPSE RATES AND CONVECTIVE TEMP ON THE 12Z ILX SOUNDING INDICATE THAT READINGS CLOSE TO 40 SHOULD RESULT IN CU FORMING...SO PARTLY SUNNY LOOKS GOOD IN THE FORECAST FOR MOST LOCATIONS. LINGERING SNOW COVER WILL KEEP HIGH TEMPS CLOSE TO 40 DEGREES IN CENTRAL IL WITH MID 40S SOUTH OF I-70. MILLER && .AVIATION... ISSUED 650 AM CDT WED MAR 27 2013 VFR CONDITIONS SHOULD CONTINUE ACROSS THE CENTRAL IL AIRPORTS THROUGH 12Z/7 AM THU. SCATTERED TO BROKEN 4.5-7K FT CLOUDS WILL OCCUR TODAY OVER CENTRAL IL ESPECIALLY ALONG I-74 TAF SITES AS SHORT WAVE OVER CENTRAL IOWA DIVES SE ACROSS CENTRAL IL BY MIDDAY AND INTO CENTRAL/EASTERN KY BY SUNSET. ALSO HAVE BROKEN CIRRUS CLOUDS 20-25K FT PASSING SE OVER CENTRAL IL INTO EARLY AFTERNOON. MOSTLY CLEAR SKIES ARE EXPECTED TONIGHT WITH FEW-SCATTERED MID LEVEL CLOUDS TONIGHT AFTER SUNSET ESPECIALLY SW AT SPI. WNW WINDS 5-10 KTS TODAY TO BECOMING LIGHT NNE TONIGHT AS 1029 MB HIGH PRESSURE RIDGE OVER THE MS VALLEY DRIFTS SLOWLY EAST INTO IL BY THU MORNING. 07 && .PREV DISCUSSION... ISSUED 303 AM CDT WED MAR 27 2013 SHORT TERM...TODAY THROUGH FRIDAY LARGE AREAS OF STRATOCUMULUS ARE STILL AFFECTING THE CWA EARLY THIS MORNING WITH SOME BREAKS WORKING IN FROM THE NORTHEAST. FEEL THIS TREND WILL CONTINUE THROUGH MUCH OF THE MORNING. STEEP LOW LEVEL LAPSE RATES AND BOUNDARY LAYER MOISTURE FROM SNOW MELT WILL LIKELY LEAD TO RAPID REFORMING OF STRATOCU IN AREAS THAT DO CLEAR OUT FOR A TIME TODAY. OVERALL PARTLY SUNNY SKIES AND LIGHTER WINDS WITH SURFACE RIDGE AXIS MOVING IN. GRADUAL THERMAL MODERATION CONTINUES AND MOST AREAS SHOULD SEE HIGHS BREAK INTO THE 40S...STILL AROUND 15 DEGREES BELOW NORMAL. QUIET WEATHER WITH SLOW WARMING TREND THU/FRI AS THE RIDGE AXIS SLOWLY SHIFTS EAST INTO THE LOWER GREAT LAKES AND OHIO VALLEY. WILL NEED TO WATCH A WARM FRONT DEVELOPING OVER MO LATE THU AS MOST MODELS SHOWING ENOUGH LIFT AND SATURATION FOR LIGHT SHOWERS NEAR THIS FEATURE INTO FRIDAY. NAM IS ONLY OPERATIONAL MODEL SHOWING THIS ACTIVITY FAR ENOUGH EAST TO AFFECT THE SOUTHWEST CWA...WHILE ALL OTHER SOLUTIONS KEEP THE LOCAL AREA DRY AND WILL FOLLOW MODEL CONSENSUS FOR NOW. LONG TERM...SATURDAY THROUGH TUESDAY A POTENT MID LEVEL TROF DIVING THROUGH SOUTHERN CANADA WILL SEND TWO COLD FRONTS SOUTHEAST ACROSS THE MIDWEST THIS WEEKEND. RELATIVELY MILD AIR STILL EXPECTED TO OVERSPREAD THE AREA WITH HIGHS GETTING INTO AT LEAST THE LOWER 50S BOTH SATURDAY AND SUNDAY. RAIN SHOWERS WILL ACCOMPANY THE INITIAL FRONTAL PASSAGE WHICH WILL MOVE THROUGH THE CWA SATURDAY NIGHT/SUNDAY MORNING. HAVE RAISED POPS TO LIKELY ACROSS THE NORTH SATURDAY NIGHT WHERE BETTER DYNAMICS ASSOCIATED WITH THE MID LEVEL TROUGH WILL BE LOCATED. THIS LOOKS TO BE A LIGHT/MODERATE RAIN EVENT QPF OF .1-.5 INCHES. SOME TIMING DIFFERENCES NOTED IN THE 00Z SOLUTIONS WITH ECMWF NOW 6+ HOURS FASTER WITH FRONTAL PASSAGE WHILE GFS SLOWER SHOWING A SFC LOW DEVELOPING ALONG THE BOUNDARY. WILL BASE FORECAST ON MORE CONSISTENT SLOWER TIMING BUT MONITOR TRENDS CLOSELY ON NEXT COUPLE RUNS. A SIGNIFICANT AIRMASS CHANGE WILL OCCUR WITH A SECONDARY FRONTAL PASSAGE ON SUNDAY NIGHT. THIS WILL SEND TEMPS CRASHING WELL BELOW NORMAL FOR MONDAY AND TUESDAY...AS A CANADIAN HIGH BUILDS FROM THE PLAINS INTO THE UPPER MIDWEST. 850 MB TEMPS DIPPING INTO A -6 TO -10 C RANGE WILL SEND HIGHS INTO THE LOW/MID 40S AND LOWS INTO THE 20S FOR THE BEGINNING OF APRIL. A SERIES OF SOUTHERN STREAM WAVES WILL SHIFT EAST FROM THE PLAINS THROUGH THE TENNESSEE VALLEY LATE MONDAY THROUGH MID- WEEK SPREADING PRECIP BACK NORTH ACROSS THE SOUTHERN FLANK OF THE COLD AIRMASS. MOST MEDIUM RANGE MODELS/ENSEMBLES SUGGEST HIGH WILL BE STRONG ENOUGH TO KEEP THIS ACTIVITY SOUTH OF THE AREA AND WILL KEEP THE FORECAST DRY THROUGH TUESDAY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1158 AM CDT WED MAR 27 2013 ...UPDATED FOR AVIATION... .SYNOPSIS... ISSUED AT 355 AM CDT WED MAR 27 2013 A QUIET ZONAL LONGWAVE PATTERN PREVAILED ACROSS MUCH OF THE CONUS. ONLY A FEW VERY MINOR SHORTWAVE DISTURBANCES WITHIN THE ZONAL LONGWAVE PATTERN COULD BE IDENTIFIED ON RAP ANALYSIS AND WATER VAPOR IMAGERY OVERNIGHT. ONE OF THESE FEATURES WAS LOCATED ACROSS THE SIOUX LAND AREA WELL TO OUR NORTHEAST...WITH A MINOR DISTURBANCE FURTHER UPSTREAM EXITING THE GREAT SALT LAKE REGION. WARM ADVECTION FROM DOWNSLOPE IN THE 800-700MB LAYER LED TO SOME VIRGA AND PERHAPS A FEW SPRINKLES ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS. NO CEILINGS BELOW 8000 FEET COULD BE FOUND ON ANY OF THE METAR OBSERVATIONS ACROSS THE CENTRAL PLAINS, THOUGH. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT WED MAR 27 2013 THE WARM-UP YESTERDAY FOLLOWING THE RECENT COLD SNAP WILL CONTINUE INTO TODAY..DESPITE THE PASSAGE OF A WEAK COLD FRONTAL BOUNDARY. THIS FRONT WILL NOT BE NOTICEABLE TEMPERATURE WISE...BUT SURFACE WINDS WILL SHIFT AROUND TO THE NORTHEAST BY EARLY TO MID AFTERNOON. THE WIND SHIFT AND ASSOCIATED WEAK COLD ADVECTION WILL BE TOO LATE AS FAR AS AFFECTING DAYTIME WARM-UP POTENTIAL. SHOULD SEE HIGHS TOUCHING OR EXCEEDING 60 DEGREES FROM THE ARKANSAS RIVER SOUTH TO THE OKLAHOMA BORDER. THE GREAT SALT LAKE DISTURBANCE (AS MENTIONED IN THE SYNOPSIS SECTION) WILL CONTINUE TO MOVE EAST-SOUTHEASTWARD DURING THE DAY WHICH WILL AID IN PUSHING THE SURFACE LOW SOUTHEAST DOWN INTO WESTERN OKLAHOMA LATE TONIGHT. LOW TEMPERATURES TONIGHT WILL BE AROUND SEASONAL AVERAGES FROM THE UPPER 20S TO THE MID/UPPER 30S ACROSS WEST CENTRAL, SOUTHWEST, AND SOUTH CENTRAL KANSAS WITH SURFACE WINDS AVERAGING 5 TO 7 KNOTS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 355 AM CDT WED MAR 27 2013 WEAK NORTHWEST ALOFT FLOW ALOFT WILL BE IN PLACE ACROSS THE HIGH PLAINS REGION THURSDAY WHILE A SURFACE ANTICYCLONE CONTINUES TO SLOWLY RETREAT FROM THE UPPER MIDWEST TOWARD THE OHIO VALLEY. THE SURFACE HIGH WILL PROVIDE LIGHT EAST TO SOUTHEASTERLY SURFACE WINDS ACROSS ON THURSDAY. THIS WILL PROVIDE A INCREASING MOISTURE IN THE BOUNDARY LAYER AS DEW POINTS RISE INTO THE 40S AND CLOUDS INCREASE (LIKELY STRATUS MAINLY ACROSS CENTRAL KANSAS). SHOWERS AND THUNDERSTORMS ARE POSSIBLE FRIDAY INTO SATURDAY, AND MORE PROBABLE CENTRAL KANSAS THAN THE FAR WEST. ANY POTENTIAL SHOWER OR STORMS WOULD LIKELY BE FOCUSED ALONG MOISTURE POOLING ZONE JUST AHEAD OF AN APPROACHING COLD FRONT COMING INTO KANSAS ON SATURDAY AFTERNOON. A FEW SHOWERS COULD OCCUR ON FRIDAY ALONG A WARM FRONT, BUT THE BETTER CHANCES WOULD SEEM MORE REASONABLE ON SATURDAY AS LOW LEVEL FORCING PLAYS A ROLE. WITH SPLIT UPPER FLOW ACROSS NORTH AMERICA AND A STRONG NW FLOW UPPER JET FOCUSED ACROSS WESTERN CANADA, ANOTHER LARGE ARCTIC HIGH PRESSURE AIRMASS IS LOOKING MORE LIKELY TO BREAK SOUTHWARD ACROSS THE U.S. GREAT PLAINS, BEGINNING AS EARLY AS SUNDAY NIGHT. THE BRUNT OF THE COLD AIR WON`T BE REALIZED ACROSS THE CENTRAL HIGH PLAINS UNTIL MONDAY AND MONDAY NIGHT. INTERESTINGLY, BOTH THE GFS AND ECMWF TRACK A 500 MB LEVEL CLOSED LOW PRESSURE SYSTEM ACROSS COLORADO ON DAY 7, PROVIDING SYNOPTIC SCALE LIFT ACROSS SOUTHWEST AND CENTRAL KANSAS TUESDAY AND TUESDAY NIGHT. DEEPLY SATURATED LAYERS SHOULD EASILY SUPPORT FREEZING RAIN OR SNOW, DEPENDING ON WHICH MODELS` THERMODYNAMIC PROFILE IS CONSIDERED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1154 AM CDT WED MAR 27 2013 VFR CONDITIONS WILL PREVAIL INTO THURSDAY. MODEL FORECAST SOUNDINGS SHOW INCREASING HIGH AND MID LEVEL CLOUDINESS AFTER MIDNIGHT. LIGHT NORTHEAST WINDS BEHIND A COLD FRONT WILL BECOME SOUTHEASTERLY AFTER 18Z THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... DDC 61 34 61 42 / 0 10 10 10 GCK 59 32 61 41 / 0 10 0 10 EHA 65 33 63 43 / 0 0 0 10 LBL 66 35 63 44 / 0 10 0 20 HYS 53 31 58 39 / 10 10 10 10 P28 62 37 61 47 / 0 10 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...UMSCHEID SHORT TERM...UMSCHEID LONG TERM...RUSSELL AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
641 AM CDT WED MAR 27 2013 ...UPDATED FOR AVIATION SECTION... .SYNOPSIS... ISSUED AT 355 AM CDT WED MAR 27 2013 A QUIET ZONAL LONGWAVE PATTERN PREVAILED ACROSS MUCH OF THE CONUS. ONLY A FEW VERY MINOR SHORTWAVE DISTURBANCES WITHIN THE ZONAL LONGWAVE PATTERN COULD BE IDENTIFIED ON RAP ANALYSIS AND WATER VAPOR IMAGERY OVERNIGHT. ONE OF THESE FEATURES WAS LOCATED ACROSS THE SIOUX LAND AREA WELL TO OUR NORTHEAST...WITH A MINOR DISTURBANCE FURTHER UPSTREAM EXITING THE GREAT SALT LAKE REGION. WARM ADVECTION FROM DOWNSLOPE IN THE 800-700MB LAYER LED TO SOME VIRGA AND PERHAPS A FEW SPRINKLES ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS. NO CEILINGS BELOW 8000 FEET COULD BE FOUND ON ANY OF THE METAR OBSERVATIONS ACROSS THE CENTRAL PLAINS, THOUGH. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT WED MAR 27 2013 THE WARM-UP YESTERDAY FOLLOWING THE RECENT COLD SNAP WILL CONTINUE INTO TODAY..DESPITE THE PASSAGE OF A WEAK COLD FRONTAL BOUNDARY. THIS FRONT WILL NOT BE NOTICEABLE TEMPERATURE WISE...BUT SURFACE WINDS WILL SHIFT AROUND TO THE NORTHEAST BY EARLY TO MID AFTERNOON. THE WIND SHIFT AND ASSOCIATED WEAK COLD ADVECTION WILL BE TOO LATE AS FAR AS AFFECTING DAYTIME WARM-UP POTENTIAL. SHOULD SEE HIGHS TOUCHING OR EXCEEDING 60 DEGREES FROM THE ARKANSAS RIVER SOUTH TO THE OKLAHOMA BORDER. THE GREAT SALT LAKE DISTURBANCE (AS MENTIONED IN THE SYNOPSIS SECTION) WILL CONTINUE TO MOVE EAST-SOUTHEASTWARD DURING THE DAY WHICH WILL AID IN PUSHING THE SURFACE LOW SOUTHEAST DOWN INTO WESTERN OKLAHOMA LATE TONIGHT. LOW TEMPERATURES TONIGHT WILL BE AROUND SEASONAL AVERAGES FROM THE UPPER 20S TO THE MID/UPPER 30S ACROSS WEST CENTRAL, SOUTHWEST, AND SOUTH CENTRAL KANSAS WITH SURFACE WINDS AVERAGING 5 TO 7 KNOTS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 355 AM CDT WED MAR 27 2013 WEAK NORTHWEST ALOFT FLOW ALOFT WILL BE IN PLACE ACROSS THE HIGH PLAINS REGION THURSDAY WHILE A SURFACE ANTICYCLONE CONTINUES TO SLOWLY RETREAT FROM THE UPPER MIDWEST TOWARD THE OHIO VALLEY. THE SURFACE HIGH WILL PROVIDE LIGHT EAST TO SOUTHEASTERLY SURFACE WINDS ACROSS ON THURSDAY. THIS WILL PROVIDE A INCREASING MOISTURE IN THE BOUNDARY LAYER AS DEW POINTS RISE INTO THE 40S AND CLOUDS INCREASE (LIKELY STRATUS MAINLY ACROSS CENTRAL KANSAS). SHOWERS AND THUNDERSTORMS ARE POSSIBLE FRIDAY INTO SATURDAY, AND MORE PROBABLE CENTRAL KANSAS THAN THE FAR WEST. ANY POTENTIAL SHOWER OR STORMS WOULD LIKELY BE FOCUSED ALONG MOISTURE POOLING ZONE JUST AHEAD OF AN APPROACHING COLD FRONT COMING INTO KANSAS ON SATURDAY AFTERNOON. A FEW SHOWERS COULD OCCUR ON FRIDAY ALONG A WARM FRONT, BUT THE BETTER CHANCES WOULD SEEM MORE REASONABLE ON SATURDAY AS LOW LEVEL FORCING PLAYS A ROLE. WITH SPLIT UPPER FLOW ACROSS NORTH AMERICA AND A STRONG NW FLOW UPPER JET FOCUSED ACROSS WESTERN CANADA, ANOTHER LARGE ARCTIC HIGH PRESSURE AIRMASS IS LOOKING MORE LIKELY TO BREAK SOUTHWARD ACROSS THE U.S. GREAT PLAINS, BEGINNING AS EARLY AS SUNDAY NIGHT. THE BRUNT OF THE COLD AIR WON`T BE REALIZED ACROSS THE CENTRAL HIGH PLAINS UNTIL MONDAY AND MONDAY NIGHT. INTERESTINGLY, BOTH THE GFS AND ECMWF TRACK A 500 MB LEVEL CLOSED LOW PRESSURE SYSTEM ACROSS COLORADO ON DAY 7, PROVIDING SYNOPTIC SCALE LIFT ACROSS SOUTHWEST AND CENTRAL KANSAS TUESDAY AND TUESDAY NIGHT. DEEPLY SATURATED LAYERS SHOULD EASILY SUPPORT FREEZING RAIN OR SNOW, DEPENDING ON WHICH MODELS` THERMODYNAMIC PROFILE IS CONSIDERED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 639 AM CDT WED MAR 27 2013 WEAK SURFACE LOW PRESSURE WILL SHIFT FROM SOUTHEAST COLORADO INTO THE PANHANDLES TODAY. AS A RESULT SURFACE WINDS WILL SHIFT FROM SOUTHEAST THIS MORNING TO NORTHEASTERLY LATER IN THE DAY. WIND SPEEDS WILL REMAIN AROUND 12 KNOTS OR LESS. MVFR CEILINGS ARE POSSIBLE OVERNIGHT, BUT CONFIDENCE IN OCCURRENCE IS LOW. && .PRELIMINARY POINT TEMPS/POPS... DDC 61 34 61 42 / 0 10 10 10 GCK 59 32 61 41 / 0 10 0 10 EHA 65 33 63 43 / 0 0 0 10 LBL 66 35 63 44 / 0 10 0 20 HYS 53 31 58 39 / 10 10 10 10 P28 62 37 61 47 / 0 10 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...UMSCHEID SHORT TERM...UMSCHEID LONG TERM...RUSSELL AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
356 AM CDT WED MAR 27 2013 ...UPDATED SYNOPSIS, SHORT TERM, LONG TERM SECTIONS... .SYNOPSIS... ISSUED AT 355 AM CDT WED MAR 27 2013 A QUIET ZONAL LONGWAVE PATTERN PREVAILED ACROSS MUCH OF THE CONUS. ONLY A FEW VERY MINOR SHORTWAVE DISTURBANCES WITHIN THE ZONAL LONGWAVE PATTERN COULD BE IDENTIFIED ON RAP ANALYSIS AND WATER VAPOR IMAGERY OVERNIGHT. ONE OF THESE FEATURES WAS LOCATED ACROSS THE SIOUX LAND AREA WELL TO OUR NORTHEAST...WITH A MINOR DISTURBANCE FURTHER UPSTREAM EXITING THE GREAT SALT LAKE REGION. WARM ADVECTION FROM DOWNSLOPE IN THE 800-700MB LAYER LED TO SOME VIRGA AND PERHAPS A FEW SPRINKLES ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS. NO CEILINGS BELOW 8000 FEET COULD BE FOUND ON ANY OF THE METAR OBSERVATIONS ACROSS THE CENTRAL PLAINS, THOUGH. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 355 AM CDT WED MAR 27 2013 THE WARM-UP YESTERDAY FOLLOWING THE RECENT COLD SNAP WILL CONTINUE INTO TODAY..DESPITE THE PASSAGE OF A WEAK COLD FRONTAL BOUNDARY. THIS FRONT WILL NOT BE NOTICEABLE TEMPERATURE WISE...BUT SURFACE WINDS WILL SHIFT AROUND TO THE NORTHEAST BY EARLY TO MID AFTERNOON. THE WIND SHIFT AND ASSOCIATED WEAK COLD ADVECTION WILL BE TOO LATE AS FAR AS AFFECTING DAYTIME WARM-UP POTENTIAL. SHOULD SEE HIGHS TOUCHING OR EXCEEDING 60 DEGREES FROM THE ARKANSAS RIVER SOUTH TO THE OKLAHOMA BORDER. THE GREAT SALT LAKE DISTURBANCE (AS MENTIONED IN THE SYNOPSIS SECTION) WILL CONTINUE TO MOVE EAST-SOUTHEASTWARD DURING THE DAY WHICH WILL AID IN PUSHING THE SURFACE LOW SOUTHEAST DOWN INTO WESTERN OKLAHOMA LATE TONIGHT. LOW TEMPERATURES TONIGHT WILL BE AROUND SEASONAL AVERAGES FROM THE UPPER 20S TO THE MID/UPPER 30S ACROSS WEST CENTRAL, SOUTHWEST, AND SOUTH CENTRAL KANSAS WITH SURFACE WINDS AVERAGING 5 TO 7 KNOTS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 355 AM CDT WED MAR 27 2013 WEAK NORTHWEST ALOFT FLOW ALOFT WILL BE IN PLACE ACROSS THE HIGH PLAINS REGION THURSDAY WHILE A SURFACE ANTICYCLONE CONTINUES TO SLOWLY RETREAT FROM THE UPPER MIDWEST TOWARD THE OHIO VALLEY. THE SURFACE HIGH WILL PROVIDE LIGHT EAST TO SOUTHEASTERLY SURFACE WINDS ACROSS ON THURSDAY. THIS WILL PROVIDE A INCREASING MOISTURE IN THE BOUNDARY LAYER AS DEW POINTS RISE INTO THE 40S AND CLOUDS INCREASE (LIKELY STRATUS MAINLY ACROSS CENTRAL KANSAS). SHOWERS AND THUNDERSTORMS ARE POSSIBLE FRIDAY INTO SATURDAY, AND MORE PROBABLE CENTRAL KANSAS THAN THE FAR WEST. ANY POTENTIAL SHOWER OR STORMS WOULD LIKELY BE FOCUSED ALONG MOISTURE POOLING ZONE JUST AHEAD OF AN APPROACHING COLD FRONT COMING INTO KANSAS ON SATURDAY AFTERNOON. A FEW SHOWERS COULD OCCUR ON FRIDAY ALONG A WARM FRONT, BUT THE BETTER CHANCES WOULD SEEM MORE REASONABLE ON SATURDAY AS LOW LEVEL FORCING PLAYS A ROLE. WITH SPLIT UPPER FLOW ACROSS NORTH AMERICA AND A STRONG NW FLOW UPPER JET FOCUSED ACROSS WESTERN CANADA, ANOTHER LARGE ARCTIC HIGH PRESSURE AIRMASS IS LOOKING MORE LIKELY TO BREAK SOUTHWARD ACROSS THE U.S. GREAT PLAINS, BEGINNING AS EARLY AS SUNDAY NIGHT. THE BRUNT OF THE COLD AIR WON`T BE REALIZED ACROSS THE CENTRAL HIGH PLAINS UNTIL MONDAY AND MONDAY NIGHT. INTERESTINGLY, BOTH THE GFS AND ECMWF TRACK A 500 MB LEVEL CLOSED LOW PRESSURE SYSTEM ACROSS COLORADO ON DAY 7, PROVIDING SYNOPTIC SCALE LIFT ACROSS SOUTHWEST AND CENTRAL KANSAS TUESDAY AND TUESDAY NIGHT. DEEPLY SATURATED LAYERS SHOULD EASILY SUPPORT FREEZING RAIN OR SNOW, DEPENDING ON WHICH MODELS` THERMODYNAMIC PROFILE IS CONSIDERED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 100 AM CDT WED MAR 27 2013 SOUTH TO SOUTHEAST WINDS ARE EXPECTED TO REMAIN IN THE 14 TO 18 KNOT RANGE THROUGH THE REMAINDER OF THE OVERNIGHT HOURS. THE WINDS WILL GRADUALLY DECREASE AS A WEAK SURFACE LOW/TROUGH AXIS MOVES INTO SOUTHWESTERN KANSAS DURING THE 12-18Z TIME FRAME WEDNESDAY. AFTER A 4 TO 6 HOUR PERIOD OF LIGHT WINDS...A NORTHEAST WIND WILL PREVAIL BY AFTERNOON...BUT SPEEDS ARE EXPECTED TO REMAIN AROUND 12 TO 15 KNOTS. NO REDUCTION IN FLIGHT CATEGORY FROM VFR IS EXPECTED THROUGH THE PERIOD. && .PRELIMINARY POINT TEMPS/POPS... DDC 61 34 61 42 / 0 10 10 10 GCK 59 32 61 41 / 0 10 0 10 EHA 65 33 63 43 / 0 0 0 10 LBL 66 35 63 44 / 0 10 0 20 HYS 53 31 58 39 / 10 10 10 10 P28 62 37 61 47 / 0 10 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...UMSCHEID SHORT TERM...UMSCHEID LONG TERM...RUSSELL AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1000 PM EDT THU MAR 28 2013 .SYNOPSIS... COLD NORTHWEST WINDS WILL ALLOW FOR A FEW SNOW SHOWERS OVERNIGHT WITH A SPRINKLE OR FLURRY POSSIBLE ON FRIDAY FOR THE RIDGES. HIGH PRESSURE WILL FINALLY BREAK THE CLOUDS FRIDAY AFTERNOON WITH MILDER TEMPERATURES AND A GOOD DEAL OF SUNSHINE FOR SATURDAY. LOW PRESSURE WILL BRING RAIN SHOWERS SUNDAY. && .NEAR TERM /THROUGH FRIDAY/... A QUICK UPDATE HAS BEEN ISSUED THIS EVENING TO ACCOUNT FOR THE LATEST TRENDS IN TEMP AND DEW POINT. THE REST OF THE PREVIOUS DISCUSSION REMAINS THE SAME. THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A NORTHWESTERLY FLOW WELL TO THE WEST OF A 500MB TROUGH AXIS LOCATED OFF THE MID-ATLANTIC. A SWATH OF MID-LAYER DRY AIR IS PASSING OVER THE AREA. HOWEVER...A 1000-750MB LAYER OF MOISTURE REMAINS IN PLACE WITH A NORTHWESTERLY LOW-LEVEL FLOW OFF OF THE EASTERN GREAT LAKES. THUS...THE AREA REMAINS CLOUDY WITH A FEW LINGERING SNOW SHOWERS ACROSS THE HIGHER ELEVATIONS EAST OF PITTSBURGH AND FLURRIES NORTH OF THE METRO. IR SAT IMAGERY INDICATES THAT THE BACK EDGE OF A STRATOCUMULUS DECK IS ACROSS CENTRAL OHIO AND IS ENCROACHING THE WESTERN FRINGES OF THE FORECAST AREA. TONIGHT...ALTHOUGH THE MID-LEVEL TROUGH AXIS OFF THE MID-ATLANTIC COAST WILL PUSH EAST OF THE AREA...THE UPPER OHIO VALLEY WILL REMAIN IN A PREVAILING NORTHWESTERLY FLOW IN ITS WAKE. THIS WILL CONTINUE TO ALLOW FOR UPSLOPING SNOW SHOWERS ACROSS THE RIDGES ALONG WITH CLOUDINESS ACROSS MUCH OF THE AREA. ANTICIPATE LITTLE ACCUMULATION...LESS THAN AN INCH...ACROSS THE RIDGES WITH WEAK FORCING AND INVERSION HEIGHTS LOWERING. FOR TEMPS...HAVE GONE 3-4 DEGREES ABOVE MAV/MET NUMBERS AS CLOUD COVERAGE WILL CONTINUE TO PROVIDE INSULATION AND PREVENT RADIATIONAL COOLING DESPITE NEAR CALM WINDS. CLOUD COVERAGE WILL BEGIN TO BREAK IN EASTERN OHIO NEAR DAWN...SO HAVE A FEW LOCATIONS THAT DROP INTO THE UPPER 20S THERE. FRIDAY...THE NORTHWESTERLY FLOW WILL CONTINUE TO PREVAIL WITH A WEAK WAVE PASSING NORTHEAST OF THE AREA LATE IN THE DAY. AS HIGH PRESSURE MOVES IN FROM THE NORTHWEST...HAVE GONE WITH A DRY FORECAST ALMOST EVERYWHERE. THE EXCEPTION IS FOR THE RIDGES EAST OF PITTSBURGH. THERE...A WEAK UPSLOPING COMPONENT WILL ALLOW FOR A FEW SNOW SHOWERS. THE LOW-LEVEL NORTHWESTERLY FLOW WILL ALLOW FOR A CLOUDY DAY EARLY...WITH THE CLOUD DECK BEGINNING TO ERODE FROM THE WEST IN THE AFTERNOON AND SKIES BEGINNING TO BREAK. HIGH TEMPS ARE CLOSER TO THE SLIGHTLY COOLER MAV...RANGING FROM THE LOWER 50S WITH MORE SUNSHINE BREAKING THROUGH IN EASTERN OHIO TO THE UPPER 30S IN THE RIDGES OF WV/MD. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... WITH CLEARING SKIES FRIDAY NIGHT UNDER SURFACE RIDGE AND LIGHT WINDS TEMPERATURES WILL FALL WELL INTO THE 20S. A QUICK WARM UP WILL THEN BE IN STORE FOR THE WEEKEND AS MOSTLY SUNNY SKIES SATURDAY ALLOW MAX TEMPS TO REACH THE 50S EXCEPT UPPER 40S FAR NORTH. CLOUDS WILL BE ON THE INCREASE SATURDAY NIGHT AND WARM ADVECTION WILL BE UNDER WAY WITH AN APPROACHING UPPER LEVEL TROUGH AND COLD FRONT FOR SUNDAY. CHANCE POPS MAINLY LATER SATURDAY NIGHT AS DEEP MOISTURE AND LIFT APPROACHES WITH CAT POPS ON SUNDAY AS THE FRONT CROSSES THE REGION. TEMPERATURES TREND NEAR NORMAL FOR SATURDAY NIGHT AND SUNDAY UNTIL FRONT PASSES EAST OF RIDGES SUNDAY EVENING. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... A SECONDARY CDFNT IS EXPD TO MOVE ACRS THE RGN MON INTO MON NGT. WL KEEP CHCS FOR SHRA/SHSN MON...CHG TO ALL SHSN MON NGT AS COLDER H8 TEMPS WORK IN FM THE NW. SHSN CHCS WL CONT TUE AND TUE NGT AS A COUPLE OF UPR LVL SHRTWVS MOVE THRU IN COLD NW FLOW. DRY CONDS SHOULD RETURN WED AND THU AS HI PRES BLDS BACK IN. TEMPS ARE EXPD TO BE WELL BLO AVG ERLY IN THE WK WITH H8 TEMPS -8 TO -12 DEG C...WITH A SLGT WRMG TREND WED AND THU. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... VFR IS EXPECTED THROUGH THE TAF PERIOD FOR A MAJORITY OF TERMINALS. FKL/DUJ WILL KEEP MVFR STRATOCU THROUGH AT LEAST LATE MORNING...WITH FKL LIKELY TO EVENTUALLY RISE TO VFR. SOME MODEL GUIDANCE INDICATES DUJ COULD EVEN DROP TO IFR...BUT THINK THIS IS PESSIMISTIC. WAS ALSO ON THE FENCE ABOUT INCLUDING MVFR CIGS IN LBE...BUT AM NOT CONFIDENT ENOUGH TO INCLUDE MVFR AT THIS TIME. NEARLY ALL SITES SHOULD BEGIN TO SCATTER OUT LATE IN THE TAF PERIOD. WINDS WILL BE OUT OF THE WEST-NORTHWEST AOB 10 KTS. .OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/... HI PRES IS EXPD TO BRING VFR CONDS LT FRI THRU SAT NGT BEFORE A SERIES OF CDFNTS BRING OCNL RESTRNS SUN THRU TUE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ SYNOPSIS...WOODRUM NEAR TERM...WOODRUM AVIATION...TGREEN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
845 PM EDT THU MAR 28 2013 .SYNOPSIS... COLD NORTHWEST WINDS WILL ALLOW FOR A FEW SNOW SHOWERS OVERNIGHT WITH A SPRINKLE OR FLURRY POSSIBLE ON FRIDAY FOR THE RIDGES. HIGH PRESSURE WILL FINALLY BREAK THE CLOUDS FRIDAY AFTERNOON WITH MILDER TEMPERATURES AND A GOOD DEAL OF SUNSHINE FOR SATURDAY. LOW PRESSURE WILL BRING RAIN SHOWERS SUNDAY. && .NEAR TERM /THROUGH FRIDAY/... 00Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCREASE CLOUD COVERAGE ACROSS THE AREA OVERNIGHT AND TO REDUCE POPS ACROSS THE LOWLANDS. THE LATEST RAP MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A NORTHWESTERLY FLOW WELL TO THE WEST OF A 500MB TROUGH AXIS LOCATED OFF THE MID-ATLANTIC. A SWATH OF MID-LAYER DRY AIR IS PASSING OVER THE AREA. HOWEVER...A 1000-750MB LAYER OF MOISTURE REMAINS IN PLACE WITH A NORTHWESTERLY LOW-LEVEL FLOW OFF OF THE EASTERN GREAT LAKES. THUS...THE AREA REMAINS CLOUDY WITH A FEW LINGERING SNOW SHOWERS ACROSS THE HIGHER ELEVATIONS EAST OF PITTSBURGH AND FLURRIES NORTH OF THE METRO. IR SAT IMAGERY INDICATES THAT THE BACK EDGE OF A STRATOCUMULUS DECK IS ACROSS CENTRAL OHIO AND IS ENCROACHING THE WESTERN FRINGES OF THE FORECAST AREA. TONIGHT...ALTHOUGH THE MID-LEVEL TROUGH AXIS OFF THE MID-ATLANTIC COAST WILL PUSH EAST OF THE AREA...THE UPPER OHIO VALLEY WILL REMAIN IN A PREVAILING NORTHWESTERLY FLOW IN ITS WAKE. THIS WILL CONTINUE TO ALLOW FOR UPSLOPING SNOW SHOWERS ACROSS THE RIDGES ALONG WITH CLOUDINESS ACROSS MUCH OF THE AREA. ANTICIPATE LITTLE ACCUMULATION...LESS THAN AN INCH...ACROSS THE RIDGES WITH WEAK FORCING AND INVERSION HEIGHTS LOWERING. FOR TEMPS...HAVE GONE 3-4 DEGREES ABOVE MAV/MET NUMBERS AS CLOUD COVERAGE WILL CONTINUE TO PROVIDE INSULATION AND PREVENT RADIATIONAL COOLING DESPITE NEAR CALM WINDS. CLOUD COVERAGE WILL BEGIN TO BREAK IN EASTERN OHIO NEAR DAWN...SO HAVE A FEW LOCATIONS THAT DROP INTO THE UPPER 20S THERE. FRIDAY...THE NORTHWESTERLY FLOW WILL CONTINUE TO PREVAIL WITH A WEAK WAVE PASSING NORTHEAST OF THE AREA LATE IN THE DAY. AS HIGH PRESSURE MOVES IN FROM THE NORTHWEST...HAVE GONE WITH A DRY FORECAST ALMOST EVERYWHERE. THE EXCEPTION IS FOR THE RIDGES EAST OF PITTSBURGH. THERE...A WEAK UPSLOPING COMPONENT WILL ALLOW FOR A FEW SNOW SHOWERS. THE LOW-LEVEL NORTHWESTERLY FLOW WILL ALLOW FOR A CLOUDY DAY EARLY...WITH THE CLOUD DECK BEGINNING TO ERODE FROM THE WEST IN THE AFTERNOON AND SKIES BEGINNING TO BREAK. HIGH TEMPS ARE CLOSER TO THE SLIGHTLY COOLER MAV...RANGING FROM THE LOWER 50S WITH MORE SUNSHINE BREAKING THROUGH IN EASTERN OHIO TO THE UPPER 30S IN THE RIDGES OF WV/MD. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... WITH CLEARING SKIES FRIDAY NIGHT UNDER SURFACE RIDGE AND LIGHT WINDS TEMPERATURES WILL FALL WELL INTO THE 20S. A QUICK WARM UP WILL THEN BE IN STORE FOR THE WEEKEND AS MOSTLY SUNNY SKIES SATURDAY ALLOW MAX TEMPS TO REACH THE 50S EXCEPT UPPER 40S FAR NORTH. CLOUDS WILL BE ON THE INCREASE SATURDAY NIGHT AND WARM ADVECTION WILL BE UNDER WAY WITH AN APPROACHING UPPER LEVEL TROUGH AND COLD FRONT FOR SUNDAY. CHANCE POPS MAINLY LATER SATURDAY NIGHT AS DEEP MOISTURE AND LIFT APPROACHES WITH CAT POPS ON SUNDAY AS THE FRONT CROSSES THE REGION. TEMPERATURES TREND NEAR NORMAL FOR SATURDAY NIGHT AND SUNDAY UNTIL FRONT PASSES EAST OF RIDGES SUNDAY EVENING. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... A SECONDARY CDFNT IS EXPD TO MOVE ACRS THE RGN MON INTO MON NGT. WL KEEP CHCS FOR SHRA/SHSN MON...CHG TO ALL SHSN MON NGT AS COLDER H8 TEMPS WORK IN FM THE NW. SHSN CHCS WL CONT TUE AND TUE NGT AS A COUPLE OF UPR LVL SHRTWVS MOVE THRU IN COLD NW FLOW. DRY CONDS SHOULD RETURN WED AND THU AS HI PRES BLDS BACK IN. TEMPS ARE EXPD TO BE WELL BLO AVG ERLY IN THE WK WITH H8 TEMPS -8 TO -12 DEG C...WITH A SLGT WRMG TREND WED AND THU. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... VFR IS EXPECTED THROUGH THE TAF PERIOD FOR A MAJORITY OF TERMINALS. FKL/DUJ WILL KEEP MVFR STRATOCU THROUGH AT LEAST LATE MORNING...WITH FKL LIKELY TO EVENTUALLY RISE TO VFR. SOME MODEL GUIDANCE INDICATES DUJ COULD EVEN DROP TO IFR...BUT THINK THIS IS PESSIMISTIC. WAS ALSO ON THE FENCE ABOUT INCLUDING MVFR CIGS IN LBE...BUT AM NOT CONFIDENT ENOUGH TO INCLUDE MVFR AT THIS TIME. NEARLY ALL SITES SHOULD BEGIN TO SCATTER OUT LATE IN THE TAF PERIOD. WINDS WILL BE OUT OF THE WEST-NORTHWEST AOB 10 KTS. .OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/... HI PRES IS EXPD TO BRING VFR CONDS LT FRI THRU SAT NGT BEFORE A SERIES OF CDFNTS BRING OCNL RESTRNS SUN THRU TUE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ SYNOPSIS...WOODRUM NEAR TERM...WOODRUM AVIATION...TGREEN
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
123 PM EDT WED MAR 27 2013 .SYNOPSIS... LOW PRESSURE WILL CONTINUE TO SPIN OVER THE NORTHERN ATLANTIC THROUGH THURSDAY. HIGH PRESSURE WILL SLOWLY BUILD INTO THE AREA FROM THE WEST THURSDAY AFTERNOON INTO SATURDAY...BRINGING A GRADUAL WARMING TREND AND MAINLY DRY CONDITIONS TO THE REGION. THE NEXT SYSTEM WILL APPROACH FROM THE WEST SATURDAY NIGHT AND MOVE ACROSS THE REGION ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS STRONG UPPER LEVEL LOW PRESSURE SPINNING NEAR 50N/50W ACRS THE NORTHERN ATLANTIC...WITH A UPPER TROUGH EXTENDING BACK TO WSW INTO THE NE STATES AND NEW ENGLAND. WITH THIS FEATURE STILL BY ANOMALOUS UPPER LEVEL HIGH PRESSURE FROM HUDSON BAY TO GREENLAND...EXPECT A CONTINUED NW FLOW AND PERIODIC SHORTWAVES TO PUSH AROUND THE BASE OF THE TROUGH ACRS THE NE AND MID ATLC STATES THROUGH THU. IN OTHER WORDS...EXPECT ONLY MINIMAL CHANGES TODAY IN COMPARISON TO YESTERDAY. OVERALL...MOISTURE FIELDS ARE SLIGHTLY DRIER SO WILL PROBABLY SEE A LITTLE LESS IN THE WAY OF CLOUD COVER ESPECIALLY THIS MORNING WHEN SKIES WILL AVG OUT PARTLY/MOSTLY SUNNY. WV SATELLITE SHOWS ANOTHER SHORTWAVE PUSHING ESE FROM WV AND THIS SHOULD BE SLIDING INTO THE CWA BY LATE MORNING INTO THE AFTN. SKIES WILL BEGIN TO CLOUD UP AND WILL TEND TO AVG OUT PARTLY TO MOSTLY CLOUDY THIS AFTN. RUC EVEN DEPICTS SOME LIGHT QPF ACRS SE VA THIS AFTN WHILE NAM AND GFS ARE DRY. GIVEN DEW PTS IN THE 20S TO LWR 30S WILL GENLY DISREGARD THIS AND KEEP POP FCST AT OR BELOW 14%. LOW LEVEL THICKNESSES ARE SIMILAR TO YESTERDAY WHEN HIGHS WERE WITHIN A DEGREE OR TWO OF 50 F THROUGHOUT THE REGION. WITH A LITTLE MORE SUNSHINE THINK HIGHS TODAY WILL BE SLIGHTLY WARMER BUT STILL ABOUT 10 DEGREES BELOW AVG...MAINLY IN THE LOWER TO MID 50S ACRS THE AREA (GENLY SIDED ON COOL SIDE OF GUIDANCE). LOOKS LIKE WITH THE INCREASING CLOUDINESS THIS AFTERNOON MAX TEMPERATURES WILL BE REACHED EARLY IN THE AFTERNOON WITH TEMPERATURES THEN BECOMING STEADY TO SLOWLY FALLING. BECOMING MOSTLY CLEAR TONIGHT...BUT OVERNIGHT AS ANOTHER SHORTWAVE DIVES SOUTH FROM THE NE STATES AND DOWN INTO THE DELMARVA SKIES WILL BECOME PARTLY CLOUDY AT LEAST ACRS THE N. TEMPS FALL FAST IN THE EVENING THEN WILL BE NEARLY STEADY OR ONLY FALL SLIGHTLY OVERNIGHT W/ MIXING AND CLOUDS. LOWS IN THE UPPER 20S SOUTH CENTRAL VA (WHERE LEAST AMT OF WIND WILL BE AND WHERE SKIES STAY MOSTLY CLEAR)..TO THE LWR-MID 30S FARTHER N/E. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... ONLY SLIGHT DIFFERENCES IN THE GFS/NAM/ECMWF MODELS OF HANDLING THE PROGRESSION OF THIS SHORTWAVE ON THU. KEPT IT DRY FOR NOW...BUT MAY NEED TO ADD A SLIGHT CHC POP TO THE LWR MD/VA ERN SHORE IF THE WAVE WERE TO DIG FARTHER SOUTH. THE INCREASED NNW FLOW WILL KEEP HIGHS SIMILAR TO OR PERHAPS SLIGHTLY COOLER THAN WED IN SOME AREAS...RANGING FROM AROUND 50 ACRS THE EASTERN SHORE TO THE MID 50S SOUTH CENTRAL VA. PARTLY SUNNY SKIES OVERALL EXCEPT PROBABLY AVERAGING OUT MSTLY CLDY FOR THE ERN SHORE. HI PRES WILL BUILD CLOSER TO THE AREA THU NGT AND FRI...AND LOWS WILL AGAIN DROP INTO THE UPPER 20S WEST OF I-95 TO THE MID- UPPER 30S AT THE IMMEDIATE COAST. OVERALL THE WARMING TREND STARTS FRI...BUT ONLY SLIGHTLY AS WE REMAIN IN NW FLOW. SKIES WILL AVG OUT MSTLY SUNNY W/ SOME SCT AFTN CLOUDS. ON FRI WITH MAX TEMPS IN THE LWR 50S NE TO MID-UPR 50S FOR MOST OF THE REST OF THE CWA. LIGHT FLOW/SFC HIGH PRESSURE BUILDS OVERHEAD FRI NIGHT...SO WILL GO A LITTLE BELOW GUIDANCE FOR LOWS DESPITE THE RISING HEIGHTS ALOFT. LOWS GENLY BETWEEN 30 AND 35. && .LONG TERM /SATURDAY THROUGH TUESDAY/... SFC HIGH PRESSURE WILL GRADUALLY BUILD EAST OVER THE REGION TO BEGIN THE WEEKEND, SLIDING OFFSHORE LATE THIS WEEKEND. RESULTANT INCREMENTAL HEIGHT INCREASE WILL TRANSLATE TO A CONTINUED GRADUAL WARMING OF TEMPERATURES OVER THE WEEKEND AND INTO MONDAY. INCREASED RAIN CHANCES A BIT BY SUNDAY AFTN/EVE EVENING IN ASSOCIATION WITH OVERRUNNING SHRAS/INCREASING BROAD ISENTROPIC LIFT AHEAD OF NEXT COLD FRONT. FRONT STILL LOOKS TO CROSS INTO THE LOCAL AREA BY LATER MONDAY W/RAIN CHCS AHEAD OF THIS FRONTAL PASSAGE RAMPING BACK UP BY LATER MON/EARLY TUE. FOR TEMPERATURES, MAXIMA WILL FINALLY BE NEAR TO ONLY SLIGHTLY BELOW AVG FOR MOST AREAS ON SAT WITH HIGHS AROUND 60 WEST OF THE BAY (STAYING COOLER/IN THE 50S NEAR THE COAST AS RELATIVELY LIGH FLOW MAY ALLOW SOME SEABREEZE DEVELOPMENT). TEMPS FINALLY WARMING TO NEAR/JUST ABOVE AVERAGE (M-U60S TO NEAR 70) FOR EASTER SUNDAY AND ON MONDAY OF NEXT WEEK IN RETURN FLOW/WAA. EARLY MORNING LOWS GRADUALLY WARMING THROUGH THE PERIOD AS WELL, GENERALLY IN THE MID 30S TO LOWER 40S. && .AVIATION /17Z WEDNESDAY THROUGH SUNDAY/... CONDITIONS WILL REMAIN VFR THROUGH THE TAF PERIOD. MIXING ASSOCIATED WITH THE UPPER WAVE PROGRESSING ACROSS THE REGION IS RESULTING IN A SCT-BKN DECK AROUND 5KFT. WIND GUSTS HAVE DECREASED SOME IN MOST LOCATIONS AS THE PRES GRAD RELAXES A LITTLE THIS AFTERNOON AND EARLY EVENING. NW WINDS WILL INCREASE AGAIN TO 15 TO 20 KT THURSDAY MORNING WITH MIXING. THE SCT-BKN CLOUD DECK AROUND 6KFT WILL RETURN THURSDAY AFTERNOON AS WELL. OUTLOOK...PASSING WEAK MID-LEVEL DISTURBANCES AND COOL AIR ALOFT WILL RESULT IN PERIODS OF DIURNAL CLOUDINESS INTO FRIDAY. OTHERWISE...VFR AND DRY CONDITIONS WILL PERSIST THROUGH EARLY WEEKEND AS HIGH PRESSURE GRADUALLY BUILDS INTO THE MID ATLANTIC FROM THE W. THERE WILL BE A CHC FOR SHOWERS BY SUNDAY OR MONDAY. && .MARINE... SCA CONTINUES IN EFFECT FOR ALL THE WATERS THROUGH EARLY THIS EVENING AND FOR THE BAY AND COASTAL WATERS TIL 10Z THURSDAY. IN SOME CASES...CONDITIONS ARE EXPECTED TO BE MARGINAL BUT THERE IS ENOUGH JUSTIFICATION TO KEEP HEADLINES IN PLACE. MODELS APPEAR TO BE UNDERCUTTING THE WINDS A BIT AND THESE WINDS STARTED TO INCREASE TO NEAR SCA IN THE BAY EARLY THIS MORNING. IN THE COASTAL WATERS...THE SCA IS MAINLY FOR SEAS WHICH ARE OCCASIONALLY REACHING 5 FT NEAR 20NM OFFSHORE...APPARENTLY DUE TO SWELLS. WINDS MAY OCCASIONALLY GUST TO 25 KNOTS...ESPECIALLY IN THE NORTHERN COASTAL WATERS. WINDS SHOULD DIMINISH A BIT AS GRADIENT SLACKENS WEDNESDAY NIGHT, THOUGH ANOTHER PERIOD OF SCA IS INDICATED ON THU/EARLY FRI AS A STRONGER SHORTWAVE MOVES OVER THE WATERS. CONDITIONS SHOULD DIMINISH FRIDAY AND INTO THE WEEKEND AS HIGH PRESSURE SETTLES OVERHEAD. SFC HIGH SLIDES OFFSHORE LATE IN THE WEEKEND, WITH RETURN (SOUTHERLY) FLOW DEVELOPING SUN/MON AHEAD OF NEXT COLD FRONT, WHICH CROSSES BY LATE MONDAY/TUESDAY OF NEXT WEEK. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633- 635>638. SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ630>632- 634-650-652-654-656-658. && $$ SYNOPSIS...LKB/TMG NEAR TERM...LKB/JAB SHORT TERM...LKB LONG TERM...MAM AVIATION...LSA/JAO MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
951 AM EDT WED MAR 27 2013 .SYNOPSIS... LOW PRESSURE WILL CONTINUE TO SPIN OVER THE NORTHERN ATLANTIC THROUGH THURSDAY. HIGH PRESSURE WILL SLOWLY BUILD INTO THE AREA FROM THE WEST THURSDAY AFTERNOON INTO SATURDAY...BRINGING A GRADUAL WARMING TREND AND MAINLY DRY CONDITIONS TO THE REGION. THE NEXT SYSTEM WILL APPROACH FROM THE WEST SATURDAY NIGHT AND MOVE ACROSS THE REGION ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS STRONG UPPER LEVEL LOW PRESSURE SPINNING NEAR 50N/50W ACRS THE NORTHERN ATLANTIC...WITH A UPPER TROUGH EXTENDING BACK TO WSW INTO THE NE STATES AND NEW ENGLAND. WITH THIS FEATURE STILL BY ANOMALOUS UPPER LEVEL HIGH PRESSURE FROM HUDSON BAY TO GREENLAND...EXPECT A CONTINUED NW FLOW AND PERIODIC SHORTWAVES TO PUSH AROUND THE BASE OF THE TROUGH ACRS THE NE AND MID ATLC STATES THROUGH THU. IN OTHER WORDS...EXPECT ONLY MINIMAL CHANGES TODAY IN COMPARISON TO YESTERDAY. OVERALL...MOISTURE FIELDS ARE SLIGHTLY DRIER SO WILL PROBABLY SEE A LITTLE LESS IN THE WAY OF CLOUD COVER ESPECIALLY THIS MORNING WHEN SKIES WILL AVG OUT PARTLY/MOSTLY SUNNY. WV SATELLITE SHOWS ANOTHER SHORTWAVE PUSHING ESE FROM WV AND THIS SHOULD BE SLIDING INTO THE CWA BY LATE MORNING INTO THE AFTN. SKIES WILL BEGIN TO CLOUD UP AND WILL TEND TO AVG OUT PARTLY TO MOSTLY CLOUDY THIS AFTN. RUC EVEN DEPICTS SOME LIGHT QPF ACRS SE VA THIS AFTN WHILE NAM AND GFS ARE DRY. GIVEN DEW PTS IN THE 20S TO LWR 30S WILL GENLY DISREGARD THIS AND KEEP POP FCST AT OR BELOW 14%. LOW LEVEL THICKNESSES ARE SIMILAR TO YESTERDAY WHEN HIGHS WERE WITHIN A DEGREE OR TWO OF 50 F THROUGHOUT THE REGION. WITH A LITTLE MORE SUNSHINE THINK HIGHS TODAY WILL BE SLIGHTLY WARMER BUT STILL ABOUT 10 DEGREES BELOW AVG...MAINLY IN THE LOWER TO MID 50S ACRS THE AREA (GENLY SIDED ON COOL SIDE OF GUIDANCE). LOOKS LIKE WITH THE INCREASING CLOUDINESS THIS AFTERNOON MAX TEMPERATURES WILL BE REACHED EARLY IN THE AFTERNOON WITH TEMPERATURES THEN BECOMING STEADY TO SLOWLY FALLING. BECOMING MOSTLY CLEAR TONIGHT...BUT OVERNIGHT AS ANOTHER SHORTWAVE DIVES SOUTH FROM THE NE STATES AND DOWN INTO THE DELMARVA SKIES WILL BECOME PARTLY CLOUDY AT LEAST ACRS THE N. TEMPS FALL FAST IN THE EVENING THEN WILL BE NEARLY STEADY OR ONLY FALL SLIGHTLY OVERNIGHT W/ MIXING AND CLOUDS. LOWS IN THE UPPER 20S SOUTH CENTRAL VA (WHERE LEAST AMT OF WIND WILL BE AND WHERE SKIES STAY MOSTLY CLEAR)..TO THE LWR-MID 30S FARTHER N/E. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... ONLY SLIGHT DIFFERENCES IN THE GFS/NAM/ECMWF MODELS OF HANDLING THE PROGRESSION OF THIS SHORTWAVE ON THU. KEPT IT DRY FOR NOW...BUT MAY NEED TO ADD A SLIGHT CHC POP TO THE LWR MD/VA ERN SHORE IF THE WAVE WERE TO DIG FARTHER SOUTH. THE INCREASED NNW FLOW WILL KEEP HIGHS SIMILAR TO OR PERHAPS SLIGHTLY COOLER THAN WED IN SOME AREAS...RANGING FROM AROUND 50 ACRS THE EASTERN SHORE TO THE MID 50S SOUTH CENTRAL VA. PARTLY SUNNY SKIES OVERALL EXCEPT PROBABLY AVERAGING OUT MSTLY CLDY FOR THE ERN SHORE. HI PRES WILL BUILD CLOSER TO THE AREA THU NGT AND FRI...AND LOWS WILL AGAIN DROP INTO THE UPPER 20S WEST OF I-95 TO THE MID- UPPER 30S AT THE IMMEDIATE COAST. OVERALL THE WARMING TREND STARTS FRI...BUT ONLY SLIGHTLY AS WE REMAIN IN NW FLOW. SKIES WILL AVG OUT MSTLY SUNNY W/ SOME SCT AFTN CLOUDS. ON FRI WITH MAX TEMPS IN THE LWR 50S NE TO MID-UPR 50S FOR MOST OF THE REST OF THE CWA. LIGHT FLOW/SFC HIGH PRESSURE BUILDS OVERHEAD FRI NIGHT...SO WILL GO A LITTLE BELOW GUIDANCE FOR LOWS DESPITE THE RISING HEIGHTS ALOFT. LOWS GENLY BETWEEN 30 AND 35. && .LONG TERM /SATURDAY THROUGH TUESDAY/... SFC HIGH PRESSURE WILL GRADUALLY BUILD EAST OVER THE REGION TO BEGIN THE WEEKEND, SLIDING OFFSHORE LATE THIS WEEKEND. RESULTANT INCREMENTAL HEIGHT INCREASE WILL TRANSLATE TO A CONTINUED GRADUAL WARMING OF TEMPERATURES OVER THE WEEKEND AND INTO MONDAY. INCREASED RAIN CHANCES A BIT BY SUNDAY AFTN/EVE EVENING IN ASSOCIATION WITH OVERRUNNING SHRAS/INCREASING BROAD ISENTROPIC LIFT AHEAD OF NEXT COLD FRONT. FRONT STILL LOOKS TO CROSS INTO THE LOCAL AREA BY LATER MONDAY W/RAIN CHCS AHEAD OF THIS FRONTAL PASSAGE RAMPING BACK UP BY LATER MON/EARLY TUE. FOR TEMPERATURES, MAXIMA WILL FINALLY BE NEAR TO ONLY SLIGHTLY BELOW AVG FOR MOST AREAS ON SAT WITH HIGHS AROUND 60 WEST OF THE BAY (STAYING COOLER/IN THE 50S NEAR THE COAST AS RELATIVELY LIGH FLOW MAY ALLOW SOME SEABREEZE DEVELOPMENT). TEMPS FINALLY WARMING TO NEAR/JUST ABOVE AVERAGE (M-U60S TO NEAR 70) FOR EASTER SUNDAY AND ON MONDAY OF NEXT WEEK IN RETURN FLOW/WAA. EARLY MORNING LOWS GRADUALLY WARMING THROUGH THE PERIOD AS WELL, GENERALLY IN THE MID 30S TO LOWER 40S. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... MAINLY CLR SKIES WILL CONTINUE THROUGH MID MORNING. TODAY IS EXPECTED TO BE FAIRLY SIMILAR TO TUESDAY WITH BKN TO OCCASIONALLY OVERCAST CLOUDS WITH BASES OF 5-7K FT AND NW WINDS GUSTING TO AROUND 20 KNOTS. SKIES CLEAR AND WINDS DIMINISH TOWARD SUNSET. LAVMOS KEEPS GUSTS GOING AT ORF WELL INTO THE EVENING. OUTLOOK...PASSING WEAK MID-LEVEL DISTURBANCES AND COOL AIR ALOFT WILL RESULT IN PERIODS OF DIURNAL CLOUDINESS THURSDAY AND PROBABLY FRIDAY. OTHERWISE...VFR AND DRY CONDITIONS WILL PERSIST THROUGH EARLY WEEKEND AS HIGH PRESSURE GRADUALLY BUILDS INTO THE MID ATLANTIC FROM THE W. THERE WILL BE A CHC FOR SHOWERS BY SUNDAY OR MONDAY. && .MARINE... SCA CONTINUES IN EFFECT FOR ALL THE WATERS THROUGH EARLY THIS EVENING AND FOR THE BAY AND COASTAL WATERS TIL 10Z THURSDAY. IN SOME CASES...CONDITIONS ARE EXPECTED TO BE MARGINAL BUT THERE IS ENOUGH JUSTIFICATION TO KEEP HEADLINES IN PLACE. MODELS APPEAR TO BE UNDERCUTTING THE WINDS A BIT AND THESE WINDS STARTED TO INCREASE TO NEAR SCA IN THE BAY EARLY THIS MORNING. IN THE COASTAL WATERS...THE SCA IS MAINLY FOR SEAS WHICH ARE OCCASIONALLY REACHING 5 FT NEAR 20NM OFFSHORE...APPARENTLY DUE TO SWELLS. WINDS MAY OCCASIONALLY GUST TO 25 KNOTS...ESPECIALLY IN THE NORTHERN COASTAL WATERS. WINDS SHOULD DIMINISH A BIT AS GRADIENT SLACKENS WEDNESDAY NIGHT, THOUGH ANOTHER PERIOD OF SCA IS INDICATED ON THU/EARLY FRI AS A STRONGER SHORTWAVE MOVES OVER THE WATERS. CONDITIONS SHOULD DIMINISH FRIDAY AND INTO THE WEEKEND AS HIGH PRESSURE SETTLES OVERHEAD. SFC HIGH SLIDES OFFSHORE LATE IN THE WEEKEND, WITH RETURN (SOUTHERLY) FLOW DEVELOPING SUN/MON AHEAD OF NEXT COLD FRONT, WHICH CROSSES BY LATE MONDAY/TUESDAY OF NEXT WEEK. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633- 635>638. SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ630>632- 634-650-652-654-656-658. && $$ SYNOPSIS...LKB/TMG NEAR TERM...LKB/JAB SHORT TERM...LKB LONG TERM...MAM AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
415 AM EDT WED MAR 27 2013 .SYNOPSIS... LOW PRESSURE WILL CONTINUE TO SPIN OVER THE NORTHERN ATLANTIC THROUGH THURSDAY. HIGH PRESSURE WILL SLOWLY BUILD INTO THE AREA FROM THE WEST THURSDAY AFTERNOON INTO SATURDAY...BRINGING A GRADUAL WARMING TREND AND MAINLY DRY CONDITIONS TO THE REGION. THE NEXT SYSTEM WILL APPROACH FROM THE WEST SATURDAY NIGHT AND MOVE ACROSS THE REGION ON SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS STRONG UPPER LEVEL LOW PRESSURE SPINNING NEAR 50N/50W ACRS THE NORTHERN ATLANTIC...WITH A UPPER TROUGH EXTENDING BACK TO WSW INTO THE NE STATES AND NEW ENGLAND. WITH THIS FEATURE STILL BY ANOMALOUS UPPER LEVEL HIGH PRESSURE FROM HUDSON BAY TO GREENLAND...EXPECT A CONTINUED NW FLOW AND PERIODIC SHORTWAVES TO PUSH AROUND THE BASE OF THE TROUGH ACRS THE NE AND MID ATLC STATES THROUGH THU. IN OTHER WORDS...EXPECT ONLY MINIMAL CHANGES TODAY IN COMPARISON TO YESTERDAY. OVERALL...MOISTURE FIELDS ARE SLIGHTLY DRIER SO WILL PROBABLY SEE A LITTLE LESS IN THE WAY OF CLOUD COVER ESPECIALLY THIS MORNING WHEN SKIES WILL AVG OUT PARTLY/MOSTLY SUNNY. WV SATELLITE SHOWS ANOTHER SHORTWAVE PUSHING ESE FROM WV AND THIS SHOULD BE SLIDING INTO THE CWA BY LATE MORNING INTO THE AFTN. SKIES WILL BEGIN TO CLOUD UP AND WILL TEND TO AVG OUT PARTLY TO MOSTLY CLOUDY THIS AFTN. RUC EVEN DEPICTS SOME LIGHT QPF ACRS SE VA THIS AFTN WHILE NAM AND GFS ARE DRY. GIVEN DEW PTS IN THE 20S TO LWR 30S WILL GENLY DISREGARD THIS AND KEEP POP FCST AT OR BELOW 14%. LOW LEVEL THICKNESSES ARE SIMILAR TO YESTERDAY WHEN HIGHS WERE WITHIN A DEGREE OR TWO OF 50 F THROUGHOUT THE REGION. WITH A LITTLE MORE SUNSHINE THINK HIGHS TODAY WILL BE SLIGHTLY WARMER BUT STILL ABOUT 10 DEGREES BELOW AVG...MAINLY IN THE LOWER TO MID 50S ACRS THE AREA (GENLY SIDED ON COOL SIDE OF GUIDANCE). BECOMING MOSTLY CLEAR TONIGHT...BUT OVERNIGHT AS ANOTHER SHORTWAVE DIVES SOUTH FROM THE NE STATES AND DOWN INTO THE DELMARVA SKIES WILL BECOME PARTLY CLOUDY AT LEAST ACRS THE N. TEMPS FALL FAST IN THE EVENING THEN WILL BE NEARLY STEADY OR ONLY FALL SLIGHTLY OVERNIGHT W/ MIXING AND CLOUDS. LOWS IN THE UPPER 20S SOUTH CENTRAL VA (WHERE LEAST AMT OF WIND WILL BE AND WHERE SKIES STAY MOSTLY CLEAR)..TO THE LWR-MID 30S FARTHER N/E. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... ONLY SLIGHT DIFFERENCES IN THE GFS/NAM/ECMWF MODELS OF HANDLING THE PROGRESSION OF THIS SHORTWAVE ON THU. KEPT IT DRY FOR NOW...BUT MAY NEED TO ADD A SLIGHT CHC POP TO THE LWR MD/VA ERN SHORE IF THE WAVE WERE TO DIG FARTHER SOUTH. THE INCREASED NNW FLOW WILL KEEP HIGHS SIMILAR TO OR PERHAPS SLIGHTLY COOLER THAN WED IN SOME AREAS...RANGING FROM AROUND 50 ACRS THE EASTERN SHORE TO THE MID 50S SOUTH CENTRAL VA. PARTLY SUNNY SKIES OVERALL EXCEPT PROBABLY AVERAGING OUT MSTLY CLDY FOR THE ERN SHORE. HI PRES WILL BUILD CLOSER TO THE AREA THU NGT AND FRI...AND LOWS WILL AGAIN DROP INTO THE UPPER 20S WEST OF I-95 TO THE MID- UPPER 30S AT THE IMMEDIATE COAST. OVERALL THE WARMING TREND STARTS FRI...BUT ONLY SLIGHTLY AS WE REMAIN IN NW FLOW. SKIES WILL AVG OUT MSTLY SUNNY W/ SOME SCT AFTN CLOUDS. ON FRI WITH MAX TEMPS IN THE LWR 50S NE TO MID-UPR 50S FOR MOST OF THE REST OF THE CWA. LIGHT FLOW/SFC HIGH PRESSURE BUILDS OVERHEAD FRI NIGHT...SO WILL GO A LITTLE BELOW GUIDANCE FOR LOWS DESPITE THE RISING HEIGHTS ALOFT. LOWS GENLY BETWEEN 30 AND 35. && .LONG TERM /SATURDAY THROUGH TUESDAY/... SFC HIGH PRESSURE WILL GRADUALLY BUILD EAST OVER THE REGION TO BEGIN THE WEEKEND, SLIDING OFFSHORE LATE THIS WEEKEND. RESULTANT INCREMENTAL HEIGHT INCREASE WILL TRANSLATE TO A CONTINUED GRADUAL WARMING OF TEMPERATURES OVER THE WEEKEND AND INTO MONDAY. INCREASED RAIN CHANCES A BIT BY SUNDAY AFTN/EVE EVENING IN ASSOCIATION WITH OVERRUNNING SHRAS/INCREASING BROAD ISENTROPIC LIFT AHEAD OF NEXT COLD FRONT. FRONT STILL LOOKS TO CROSS INTO THE LOCAL AREA BY LATER MONDAY W/RAIN CHCS AHEAD OF THIS FRONTAL PASSAGE RAMPING BACK UP BY LATER MON/EARLY TUE. FOR TEMPERATURES, MAXIMA WILL FINALLY BE NEAR TO ONLY SLIGHTLY BELOW AVG FOR MOST AREAS ON SAT WITH HIGHS AROUND 60 WEST OF THE BAY (STAYING COOLER/IN THE 50S NEAR THE COAST AS RELATIVELY LIGH FLOW MAY ALLOW SOME SEABREEZE DEVELOPMENT). TEMPS FINALLY WARMING TO NEAR/JUST ABOVE AVERAGE (M-U60S TO NEAR 70) FOR EASTER SUNDAY AND ON MONDAY OF NEXT WEEK IN RETURN FLOW/WAA. EARLY MORNING LOWS GRADUALLY WARMING THROUGH THE PERIOD AS WELL, GENERALLY IN THE MID 30S TO LOWER 40S. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... MAINLY CLR SKIES WILL CONTINUE THROUGH MID MORNING. TODAY IS EXPECTED TO BE FAIRLY SIMILAR TO TUESDAY WITH BKN TO OCCASIONALLY OVERCAST CLOUDS WITH BASES OF 5-7K FT AND NW WINDS GUSTING TO AROUND 20 KNOTS. SKIES CLEAR AND WINDS DIMINISH TOWARD SUNSET. LAVMOS KEEPS GUSTS GOING AT ORF WELL INTO THE EVENING. OUTLOOK...PASSING WEAK MID-LEVEL DISTURBANCES AND COOL AIR ALOFT WILL RESULT IN PERIODS OF DIURNAL CLOUDINESS THURSDAY AND PROBABLY FRIDAY. OTHERWISE...VFR AND DRY CONDITIONS WILL PERSIST THROUGH EARLY WEEKEND AS HIGH PRESSURE GRADUALLY BUILDS INTO THE MID ATLANTIC FROM THE W. THERE WILL BE A CHC FOR SHOWERS BY SUNDAY OR MONDAY. && .MARINE... SCA CONTINUES IN EFFECT FOR ALL THE WATERS THROUGH EARLY THIS EVENING AND FOR THE BAY AND COASTAL WATERS TIL 10Z THURSDAY. IN SOME CASES...CONDITIONS ARE EXPECTED TO BE MARGINAL BUT THERE IS ENOUGH JUSTIFICATION TO KEEP HEADLINES IN PLACE. MODELS APPEAR TO BE UNDERCUTTING THE WINDS A BIT AND THESE WINDS STARTED TO INCREASE TO NEAR SCA IN THE BAY EARLY THIS MORNING. IN THE COASTAL WATERS...THE SCA IS MAINLY FOR SEAS WHICH ARE OCCASIONALLY REACHING 5 FT NEAR 20NM OFFSHORE...APPARENTLY DUE TO SWELLS. WINDS MAY OCCASIONALLY GUST TO 25 KNOTS...ESPECIALLY IN THE NORTHERN COASTAL WATERS. WINDS SHOULD DIMINISH A BIT AS GRADIENT SLACKENS WEDNESDAY NIGHT, THOUGH ANOTHER PERIOD OF SCA IS INDICATED ON THU/EARLY FRI AS A STRONGER SHORTWAVE MOVES OVER THE WATERS. CONDITIONS SHOULD DIMINISH FRIDAY AND INTO THE WEEKEND AS HIGH PRESSURE SETTLES OVERHEAD. SFC HIGH SLIDES OFFSHORE LATE IN THE WEEKEND, WITH RETURN (SOUTHERLY) FLOW DEVELOPING SUN/MON AHEAD OF NEXT COLD FRONT, WHICH CROSSES BY LATE MONDAY/TUESDAY OF NEXT WEEK. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633- 635>638. SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ630>632- 634-650-652-654-656-658. && $$ SYNOPSIS...LKB/TMG NEAR TERM...LKB SHORT TERM...LKB LONG TERM...MAM AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
400 AM EDT WED MAR 27 2013 .SYNOPSIS... LOW PRESSURE WILL CONTINUE TO SPIN OVER THE NORTHERN ATLANTIC OVERNIGHT THROUGH THURSDAY. HIGH PRESSURE WILL SLOWLY BUILD INTO THE AREA FROM THE WEST WEDNESDAY AFTERNOON INTO SATURDAY...BRINGING A GRADUAL WARMING TREND AND MAINLY DRY CONDITIONS TO THE REGION. && .NEAR TERM /THROUGH TONIGHT/... LATEST WX ANALYSIS DEPICTS STRONG UPPER LEVEL LOW PRESSURE SPINNING NEAR 50N/50W ACRS THE NORTHERN ATLANTIC...WITH A UPPER TROUGH EXTENDING BACK TO WSW INTO THE NE STATES AND NEW ENGLAND. WITH THIS FEATURE STILL BY ANOMALOUS UPPER LEVEL HIGH PRESSURE FROM HUDSON BAY TO GREENLAND...EXPECT A CONTINUED NW FLOW AND PERIODIC SHORTWAVES TO PUSH AROUND THE BASE OF THE TROUGH ACRS THE NE AND MID ATLC STATES THROUGH THU. IN OTHER WORDS...EXPECT ONLY MINIMAL CHANGES TODAY IN CAOMPARISON TO YESTERDAY. OVERALL...MOSITURE FIELDS ARE SLIGHTLY DRIER SO WILL PRAOBALY SEE A LITTLE LESS IN THE WAY OF CLOUD COVER ESPECIALLY THIS MORNING WHEN SKIES WILL AVG OUT PARTLY/MOSTLY SUNNY. WITH ANOTHER SHORTWAVE PUSHING ESE FROM WV BY LATE MORNING INTO THE AFTN SKIES WILL BEGIN TO CLOUD UP AND WILL TEND TO AVG OUT PARTLY TO MOSTLY CLOUDY THIS AFTN. RUC EVEN DEPICTS SOME LIGHT QPF ACRS SE VA THIS AFTN WHILE NAM AND GFS ARE DRY. GIVEN DEW PTS IN THE 20S TO LWR 30S WILL GENLY DISREGARD THIS AND KEEP POP FCST AT OR BELOW 14%. LOW LEVEL THICKNESSES ARE SIMILAR TO YESTERDAY WHEN HIGHS WERE WITHIN A DEGREE OR TWO OF 50 F THROUGHOUT THE REGION. WITH A LITTLE MORE SUNSHINE THINK HIGHS TODAY WILL BE SLIGHTLY WARMER BUT STILL ABOUT 10 DEGREES BELOW AVG...MAINLY IN THE LOWER TO MID 50S ACRS THE AREA (GENLY SIDED ON COOL SIDE OF GUIDANCE). BECOMING MOSTLY CLEAR TONIGHT...BUT OVERNIGHT AS ANOTHER SHORTAVE DIVES SOUTH FROM THE NE STATES AND DOWN INTO THE DELMARVA SKIES WILL BECOME PARTLY CLOUDY AT LEAST ACRS THE N. TEMPS FALL FAST IN THE EVENING THEN WILL BE NEARLY STEADY OR ONLY FALL SLIGHTLY OVERNIGHT W/ MIXING AND CLOUDS. LOWS IN THE UPPER 20S SOUTH CENTRAL VA (WHERE LEAST AMT OF WIND WILL BE AND WHERE SKIES STAY MOSTLY CLEAR)..TO THE LWR-MID 30S FARTHER N/E. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... ONLY SLGT DIFFERENCES IN THE GFS/NAM/ECMWF MODELS OF HANDLING THE PROGRESSION OF THIS SHORTAVE ON THU. KEPT IT DRY FOR NOW...BUT MAY NEED TO ADD A SLGT CHC POP TO THE LWR MD/VA ERN SHR IF THE WAVE WERE TO DIG FARTHER SOUTH. THE INCREASED NNW FLOW WILL KEEP HIGHS SIMILAR TO OR PERHAPS SLIGHTLY COOLER THAN WED...MAINLY 50-55 (COOLEST NE). PARTLY SUNNY SKIES (MSTLY CLDY NE). HI PRES WILL BLD CLSR TO THE AREA THU NGT AND FRI...AND LOWS WILL AGAIN DROP INTO THE UPPER 20S WEST OF I-95 TO THE MID-UPPER 30S AT THE IMMEDIATE COAST. MSTLY CLR THU NGT WITH LOWS RANGING FM THE UPR 20S TO UPR 30S. OVERALL WTHE WARMING TREND STARTS FRI...BUT ONLY SLIGHTLY AS WE REMAIN IN NW FLOW. SKIES WILL AVG OUT MSTLY SNY W/ SOME SCT AFTN CLOUDS. ON FRI WITH MAX TEMPS IN THE LWR 50S NE TO UPR 50S SW. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... SFC HIGH PRESSURE WILL GRADUALLY BUILD EAST OVER THE REGION TO BEGIN THE WEEKEND, SLIDING OFFSHORE LATE THIS WEEKEND. RESULTANT INCREMENTAL HEIGHT INCREASE WILL TRANSLATE TO A GRADUAL WARMING OF TEMPERATURES OVER THE WEEKEND AND INTO MONDAY. INCREASED RAIN CHANCES A BIT BY SUNDAY AFTN/EVE EVENING IN ASSOCIATION WITH OVERRUNNING SHRAS/INCREASING BROAD ISENTROPIC LIFT AHEAD OF NEXT COLD FRONT. FRONT STILL LOOKS TO CROSS INTO THE LOCAL AREA BY LATER MONDAY W/RAIN CHCS AHEAD OF THIS FRONTAL PASSAGE RAMPING BACK UP BY LATER MON/EARLY TUE. FOR TEMPERATURES, MAXIMA REMAIN BELOW NORMAL FOR THE LATE WEEK PERIOD (M/U50S), FINALLY WARMING TO NEAR/JUST ABOVE AVERAGE (M-U60S TO NEAR 70) FOR EASTER SUNDAY AND ON MONDAY OF NEXT WEEK IN RETURN FLOW/WAA. EARLY MORNING LOWS GRADUALLY WARMING THROUGH THE PERIOD AS WELL, GENERALLY IN THE MID 30S TO LOWER 40S. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... MAINLY CLR SKIES WILL CONTINUE THROUGH MID MORNING. TODAY IS EXPECTED TO BE FAIRLY SIMILAR TO TUESDAY WITH BKN TO OCCASIONALLY OVERCAST CLOUDS WITH BASES OF 5-7K FT AND NW WINDS GUSTING TO AROUND 20 KNOTS. SKIES CLEAR AND WINDS DIMINISH TOWARD SUNSET. LAVMOS KEEPS GUSTS GOING AT ORF WELL INTO THE EVENING. OUTLOOK...PASSING WEAK MID-LEVEL DISTURBANCES AND COOL AIR ALOFT WILL RESULT IN PERIODS OF DIURNAL CLOUDINESS THURSDAY AND PROBABLY FRIDAY. OTHERWISE...VFR AND DRY CONDITIONS WILL PERSIST THROUGH EARLY WEEKEND AS HIGH PRESSURE GRADUALLY BUILDS INTO THE MID ATLANTIC FROM THE W. THERE WILL BE A CHC FOR SHOWERS BY SUNDAY OR MONDAY. && .MARINE... SCA CONTINUES IN EFFECT FOR ALL THE WATERS THROUGH EARLY THIS EVENING AND FOR THE BAY AND COASTAL WATERS TIL 10Z THURSDAY. IN SOME CASES...CONDITIONS ARE EXPECTED TO BE MARGINAL BUT THERE IS ENOUGH JUSTIFICATION TO KEEP HEADLINES IN PLACE. MODELS APPEAR TO BE UNDERCUTTING THE WINDS A BIT AND THESE WINDS STARTED TO INCREASE TO NEAR SCA IN THE BAY EARLY THIS MORNING. IN THE COASTAL WATERS...THE SCA IS MAINLY FOR SEAS WHICH ARE OCCASIONALLY REACHING 5 FT NEAR 20NM OFFSHORE...APPARENTLY DUE TO SWELLS. WINDS MAY OCCASIONALLY GUST TO 25 KNOTS...ESPECIALLY IN THE NORTHERN COASTAL WATERS. WINDS SHOULD DIMINISH A BIT AS GRADIENT SLACKENS WEDNESDAY NIGHT, THOUGH ANOTHER PERIOD OF SCA IS INDICATED ON THU/EARLY FRI AS A STRONGER SHORTWAVE MOVES OVER THE WATERS. CONDITIONS SHOULD DIMINISH FRIDAY AND INTO THE WEEKEND AS HIGH PRESSURE SETTLES OVERHEAD. SFC HIGH SLIDES OFFSHORE LATE IN THE WEEKEND, WITH RETURN (SOUTHERLY) FLOW DEVELOPING SUN/MON AHEAD OF NEXT COLD FRONT, WHICH CROSSES BY LATE MONDAY/TUESDAY OF NEXT WEEK. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633- 635>638. SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ630>632- 634-650-652-654-656-658. && $$ SYNOPSIS...LKB/TMG NEAR TERM...LKB SHORT TERM...LKB LONG TERM...MAM AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1113 PM CDT TUE MAR 26 2013 .SYNOPSIS... ISSUED AT 339 PM CDT TUE MAR 26 2013 AT 19Z...SURFACE ANALYSIS INDICATED A WEAK WARM FRONT ACROSS WYOMING AND WESTERN NEBRASKA. THERE WAS ALSO A LOW PRESSURE CENTER OVER NORTHERN NEW MEXICO WITH ANOTHER WARM FRONT EXTENDING ACROSS NORTH TEXAS. WATER VAPOR IMAGERY SHOWED A MATURING WAVE OVER THE MONTANA-WYOMING LINE. VISIBLE SATELLITE IMAGERY SHOWED SOME CUMULUS DEVELOPMENT IN THE SOUTHWEST NEBRASKA PANHANDLE AND OVER SOUTHEAST WYOMING. && .UPDATE... ISSUED AT 1109 PM CDT TUE MAR 26 2013 THE RAP13 HAS A GOOD FIX ON THE RAIN AND SNOW SHOWERS DRIFTING EAST OVERNIGHT THROUGH SWRN NEB AND KEEPS THE ACTIVITY GOING WEDNESDAY MORNING. THE MODEL ALSO FCSTS HIGHS IN THE 50S AND PERFORMED BETTER WITH TUESDAYS HIGHS IN THE UPPER 40S SO A NEW FCST IS OUT FOR THESE TWO ELEMENTS. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 339 PM CDT TUE MAR 26 2013 FOR TONIGHT...RETURN FLOW OVER THE WEAK WARM FRONT IN NEBRASKA AND SOUTH DAKOTA WILL GENERATE DECENT ISENTROPIC LIFT FROM SOUTHERN SOUTH DAKOTA TO SOUTHWEST NEBRASKA. HOWEVER...EXCEPT FOR SOUTHERN SOUTH DAKOTA...THE LIFTED AIR IS QUITE DRY (SATURATION DEFICITS EXCEEDING 90MB) WITH POCKETS OF LOWER SATURATION DEFICITS. THETA-E FOLDS IN THE 290-300K LAYER INDICATE SOME INSTABILITY...ESPECIALLY IN SOUTHERN NEBRASKA...SO SOME MENTION OF PRECIPITATION IS STILL APPROPRIATE THOUGH WE WILL KEEP THE COVERAGE/PROBABILITY LOW. THERE IS SOME LIFT IN THE DENDRITIC LAYER WITH RELATIVE HUMIDITY 70-90 PERCENT...SO SNOW IS LIKELY TO FORM ALOFT. TEMPERATURES IN THE BOUNDARY LAYER ARE ABOVE 0C...BUT WET BULB TEMPERATURES ARE BELOW 0C. THEREFORE...IF ANY PRECIPITATION CAN REACH THE SURFACE...SNOW WOULD MOST LIKELY BE THE FORM IT WOULD TAKE. IN NORTHERN NEBRASKA...THE NORTH AMERICAN MODEL AND THE RAPID UPDATE MODEL ARE INDICATING SUBSIDENCE ABOVE A MOIST TO SATURATED NEAR-SURFACE LAYER. TEMPERATURE IN THE MOIST LAYER IS EXPECTED TO BE BELOW 0C...SO THERE IS SOME RISK OF FREEZING DRIZZLE. FOR WEDNESDAY...WE ARE EXPECTING DRIER AIR OVER CENTRAL AND WESTERN NEBRASKA. CLOUDS ARE LIKELY TO CLEAR...BUT THE COLD AIR WILL CONTINUE OVER THE AREA. THEREFORE...TEMPERATURES WILL BE ONLY SLIGHTLY WARMER THAN WE ARE HAVING TODAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 339 PM CDT TUE MAR 26 2013 THIS PORTION OF THE FORECAST WILL SEE WARMING THROUGH THE WEEKEND...WITH A CHANCE FOR A FEW THUNDERSTORMS...THEN ANOTHER COOL DOWN FOR EARLY NEXT WEEK. ALTHOUGH THE PATTERN WILL ALLOW FOR GOOD WARM AIR ADVECTION INTO THE FORECAST AREA FRIDAY AND SATURDAY...THE REGION WILL BE ANCHORED IN NORTHWEST FLOW THROUGHOUT THIS PERIOD...WITH MULTIPLE WEAK SHORTWAVE TROUGHS PASSING ACROSS THE AREA. WEAK ENERGY ALOFT WILL BE MOVING INTO THE CENTRAL PLAINS AFTER MIDNIGHT WEDNESDAY NIGHT...WHICH THEN CROSSES REGION BY THE END OF THE DAY ON THURSDAY. THERE WOULD BE ENOUGH LIFT TO SUGGEST A NEED FOR PRECIPITATION CHANCES ACROSS THE NORTHERN TIER OF COUNTIES IN NEBRASKA...HOWEVER MOISTURE IS SEVERELY LACKING. CROSS SECTIONS AND SOUNDINGS IN THESE AREAS SHOW A SATURATION WILL NOT BE ACHIEVED SO HELD OFF ON ANY MENTION OF PRECIPITATION THROUGH THIS TIME FRAME. COULD BE AN INSTANCE WITH A NEED FOR FLURRIES/SPRINKLES...HOWEVER KEPT THE MENTION OUT OF THE FORECAST AT THIS POINT. THE STORY FOR FRIDAY AND SATURDAY WILL BE WARMING TEMPERATURES...ALONG WITH A CHANCE FOR SHOWERS AND THUNDERSTORMS. TEMPERATURES WILL WARM QUITE A BIT UNDER SOUTHERLY LOW LEVEL FLOW...WITH 850MB TEMPERATURES LOOKING TO RISE INTO THE LOW AND MID TEENS OVER SOUTHWEST NEBRASKA BY 00Z SATURDAY. THERE DOES REMAIN A QUESTION TO HOW WARM IT WILL GET...DEPENDING IF CURRENT SNOW COVER IS GONE...AS WELL AS THE AMOUNT OF CLOUD COVER. AFTERNOON MIXING AND SOME INCREASED MOISTURE SHOULD BRING AN INCREASE IN CLOUDS. THE FORECAST STAYS NEAR THE MIDDLE OF THE ROAD UNTIL CONFIDENCE INCREASES. BUT...HIGHS AT LEAST AROUND 60 NEAR AND WEST OF HIGHWAY 83...WITH 50S TO THE EAST LOOKS LIKELY FOR FRIDAY. SOME INSTABILITY DOES BUILD INTO SOUTHWEST NEBRASKA FRIDAY AFTERNOON...WITH MU CAPE VALUES OF A FEW HUNDRED. CONTINUED THE MENTION OF ISOLATED THUNDER AT THIS POINT AS WOULD LIKE TO SEE A STRONGER SIGNAL FROM A SYNOPTIC STANDPOINT...STEEPER LAPSE RATES...AND MORE INSTABILITY TO GET WIDESPREAD THUNDERSTORMS. A FRONT IS BEING PROJECTED TO MOVE EAST ACROSS THE FORECAST AREA FRIDAY NIGHT WHICH WILL CONTINUE THE CHANCES FOR PRECIPITATION THROUGH THE NIGHT. THUNDER MENTION WILL REMAIN IN THE EVENING HOURS...BUT AS INSTABILITY DIMINISHES OVERNIGHT...SHOULD JUST SEE RAIN SHOWERS. THE HIGHER CHANCES FOR RAIN ON SATURDAY WILL BE ACROSS CENTRAL NEBRASKA AS THE FRONT CONTINUES TO MOVE EASTWARD. WILL STILL HAVE A CHANCE FOR THUNDERSTORMS THROUGH THE DAY...BUT AGAIN...THE SITUATION IS NOT LOOKING FOR ANY WIDESPREAD THUNDERSTORMS...AND WITH MODELS ONLY INDICATING MODERATE SHEAR VALUES...AT THIS TIME NOT EXPECTING ANY STRONG STORMS. SATURDAY NIGHT THROUGH MONDAY WILL SEE AN UPPER LOW COME SOUTH OUT OF CANADA INTO THE GREAT LAKES. THIS SYSTEM WILL PUSH A BACKDOOR COLD FRONT ACROSS NEBRASKA. THE IMPACT FROM THIS FRONT IN TERMS OF TEMPERATURES SHOULDN/T BE REALIZED UNTIL SUNDAY NIGHT AND MONDAY...ALTHOUGH HIGHS ON SUNDAY IN NORTH CENTRAL NEBRASKA WILL BE COOLER THAN AREAS TO THE SOUTH. SO...FOR THE START OF THE NEXT WORK WEEK...COULD AGAIN BE LOOKING AT HIGHS IN THE 40S...WITH LOWS DROPPING INTO THE TEENS AND 20S. ALSO...THE COLD FRONT IS BEING PROJECTED TO BE PLACED JUST SOUTH OF NEBRASKA FOR SUNDAY THROUGH TUESDAY...AND WITH WEAK SHORTWAVES PASSING BY THE AREA ALOFT...COULD BE ENOUGH TO SPARK OFF THE DEVELOPMENT OF PRECIPITATION. WITH THE COLDER AIR...THIS PRECIPITATION WILL LIKELY BE SNOW AT TIMES. DUE TO MODEL DIFFERENCES IN TEMPERATURE FIELDS...AND A BIT OF UNCERTAINTY IN WHERE THE FRONT WILL BE...CONTINUED WITH JUST SLIGHT CHANCES FOR NOW AND A RAIN/SNOW MIX THROUGH MUCH OF THE FIRST PART OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1109 PM CDT TUE MAR 26 2013 VFR IS EXPECTED MOST AREAS TONIGHT THROUGH WEDNESDAY EVENING. A WEAK DISTURBANCE...CURRENTLY ACROSS ERN WY AND THE SRN NEB PANHANDLE WILL MOVE EAST OVERNIGHT. THE LATEST RAP MODEL SUGGEST THIS ACTIVITY COULD CONTINUE FOR FEW HOURS WEDNESDAY MORNING. LOCAL MVFR IS POSSIBLE IN ISOLATED RAIN AND SNOW SHOWERS...MAINLY ALONG AND SOUTH OF INTERSTATE 80. OTHERWISE...THE NAM MODEL CONTINUES TO ADVERTISE STRATUS AND PERHAPS FREEZING DRIZZLE ACROSS NRN NEB TONIGHT. THE RUC HOWEVER WILL HAVE NONE OF THAT KEEPING SKIES VFR. THE GFS...GEM AND ECM MODELS ARE IN BETWEEN...SHOWING AN INCREASE IN LOW LEVEL MOISTURE...BUT NOT ENOUGH FOR STRATUS. GIVEN THE CURRENT OBSERVATIONS...SATELLITE TRENDS AND RECENT LOW LEVEL MOIST BIAS IN THE NAM...THE FCST CALLS FOR VFR ACROSS NORTHERN NEB...THE MOST LIKELY SCENARIO. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CDC SYNOPSIS...SPRINGER SHORT TERM...SPRINGER LONG TERM...BROOKS AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
624 PM EDT WED MAR 27 2013 .SYNOPSIS... A COLD NORTHWEST FLOW WILL PERSIST THROUGH THE REMAINDER OF THE WORK WEEK...OCCASIONALLY BRINGING SCATTERED SNOW AND RAIN SHOWERS. TEMPERATURES WILL FINALLY BUT BRIEFLY TURN SLIGHTLY MILDER OVER THE WEEKEND...AND THEN WE WILL RETURN TO A COOL UNSETTLED PATTERN. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 4 PM UPDATE... QUICK UPDATE TO EXPAND 50 POPS ACRS MOST OF THE CWA WITH EXCEPTION OF NERN CNTYS AS THEY RMN UNDER SUBSIDENCE AFT FIRST S/WV PASSED BY. EXPECT SNOW SHOWERS TO WEAKEN BY 00Z TNGT BFR RE-DVLPNG AFT MIDNIGHT AS MAIN UL TROF DROPS THRU AND REGENERATES POPS. 130 PM UPDATE... WEAK WAVE IS DROPPING OVER THE REGION WHICH WITH DIURNAL HEATING IS CAUSING EXPECTED BLOSSOM OF SCATTERED RAIN/SNOW SHOWERS AND SPRINKLES/FLURRIES. AS PER LOCAL HIGH RESOLUTION MODELS...WE ARE HAVING A RELATIVE MAXIMUM IN DIURNAL ACTIVITY ACROSS THE CENTRAL TO SOUTHWESTERN ZONES COMPARED TO THE NORTHEAST. SUBSIDENCE AND DRIER COLUMN THIS AFTERNOON/EARLY EVENING BEHIND WAVE IN THE NORTHEASTERN ZONES INCLUDING MOHAWK VALLEY AND NY THRUWAY...SHOULD LEAD TO RELATIVE MINIMUM IN ACTIVITY THERE...BEFORE BETTER WAVE DROPS IN LATER TONIGHT. FORECAST DETAILS HAVE BEEN ADJUSTED ACCORDINGLY. RUC/RAP SOUNDINGS HAVE STEEPER LAPSE RATES AND THUS MORE INSTABILITY COMPARED TO THE NAM. GIVEN THAT MAV AND ESPECIALLY MET GUIDANCE HAVE BEEN TOO COLD LATELY...AND THE EXTRA ENERGY FROM EARLY SUNSHINE TODAY...THE MORE UNSTABLE RUC SOUNDINGS ARE A BETTER REPRESENTATION. CONVECTIVE NATURE TO THE SCATTERED SHOWERS ARE THUS BEING REALIZED AS CAN BE SEEN ON THE RADAR THE LAST HOUR OR SO...COMPLETE WITH BURSTS OF GRAUPEL. ALSO...MET GUIDANCE AGAIN HAS BEEN SHOWN TO BE MUCH TOO COOL FOR TEMPERATURES THIS AFTERNOON. AFTER DIURNAL ACTIVITY WANES LATE AFTERNOON INTO EVENING...A BETTER UPPER TROUGH WILL DROP NORTH TO SOUTH 03Z-09Z OVERNIGHT...ALLOWING SCATTERED SNOW SHOWERS TO REDEVELOP...ESPECIALLY CENTRAL NY. THAT BEING SAID...ACCUMULATIONS WILL BE GENERALLY ONLY A FEW TO SEVERAL TENTHS OF AN INCH FOR MOST LOCATIONS. WITH AMOUNT OF CLOUDS OVERNIGHT...NOT FIGURING ON MUCH RADIATIONAL COOLING AND SO NEAR OR SLIGHTLY ABOVE BLENDED GUIDANCE IS EXPECTED FOR LOW TEMPERATURES /MID 20S TO AROUND 30/. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... 230 PM UPDATE... MAIN UPPER TROUGH AXIS WILL FINISH EXITING SOUTH THURSDAY MORNING. MODELS SUGGEST THAT A WEAKER SHORTWAVE WILL STILL SLIP THROUGH DURING THE DAY. HOWEVER...THICKNESSES WILL BE A GOOD 5 OR SO DECAMETERS HIGHER...AND SO LAPSE RATES WILL NOT BE AS STEEP. AS DIURNAL ENERGY AGAIN TRIES TO BURP UP SCATTERED SHOWERS...THERE WILL NOT BE AS MUCH INSTABILITY COMPARED TO 24 HOURS PRIOR...AND RIDGING WILL ALREADY BE INITIATING ALOFT. I ONLY PLACED SLIGHT TO LOW CHANCE POPS...AND MAINLY UP TO MIDDAY...FOR DIURNAL ENHANCEMENT AND PASSING WAVE. AS WITH RECENT DAYS...I HAVE STAYED ON WARM SIDE OF MODEL GUIDANCE FOR HIGH TEMPERATURES THURSDAY...ESPECIALLY THE MAV WHICH HAS BEEN MUCH TOO COOL LATELY. MAINLY 40S AREAWIDE. WETBULBING AGAIN WILL ALLOW SNOW OR GRAUPEL WITHIN THE SHOWERS DESPITE TEMPERATURES GETTING WELL ABOVE FREEZING. WEAK RIDGING THURSDAY EVENING...WILL GIVE WAY TO ANOTHER WEAK TROUGH THAT WILL DIP INTO THE AREA FRIDAY...THOUGH FOR THE FIRST TIME IN QUITE AWHILE...NOT ONE ASSOCIATED WITH THE RESIDENT UPPER LOW IN THE CANADIAN MARITIMES. MOISTURE WILL BE FAIRLY SHALLOW...YET LAPSE RATES ALSO STEEPER. THUS WITH THE PASSING FEATURE...DIURNAL INSTABILITY WILL PROBABLY HELP TO REALIZE ADDITIONAL SCATTERED RAIN/SNOW SHOWERS. BY SATURDAY...CYCLONIC FLOW WILL GIVE WAY TO A BETTER RIDGE ON ITS WAY IN. MOISTURE GETS VERY SHALLOW AS WARM AIR ADVECTION ENSUES ALOFT. FIGURING ON A DRY NEAR CLIMATOLOGY DAY WITH STRATOCUMULUS BECOME MORE CELLULAR AND THEN SCATTERING OUT. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... 2 PM UPDATE... FOLLOWED WPC GUIDANCE. A BRIEF BREAK IN THE COLD SAT NGT TO SUNDAY WITH SFC HIGH PRESSURE AND AN UL RIDGE. A COLD FRONT GOES THROUGH SUN AFTN AND EVE WITH MOSTLY RAIN...WHICH MAY CHANGE TO SNOW BEFORE ENDING. ANOTHER BREAK LATE SUN NGT TO MON BEFORE COLDER AIR COMES IN MON NGT WITH SNOW...A COLD FRONT AND STRONG SHORT WAVE. THE LOW LEVEL FLOW SHIFTS TO NW BEHIND THE FRONT SO SNOW SHOWERS FOR TUES AND WED. COOLER THAN NORMAL WITH A DEEP UPPER LEVEL TROF IN THE NE US. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... LINE OF SNOW SQUALLS MOVING TOWARD BGM WILL PRODUCE TEMPO IFR CONDITIONS BETWEEN 630 PM AND 8 PM EDT. THEREAFTER THE CONVECTIVE ELEMENTS OF THE SNOW/RAIN SHOWERS WILL WEAKEN AND DISSIPATE. HOWEVER ENERGY MOVING OFF THE LAKES WILL CAUSE LIGHT SNOW SHOWERS OR FLURRIES TO REFORM OVERNIGHT. THIS ACTIVITY WILL BE VERY HIT AND MISS, AND WILL BE ON THE LIGHT SIDE. SO WE WILL FORECAST MVFR RESTRICTIONS WITHIN SNOW SHOWERS. GENERALLY LOW VFR TO HIGH MVFR CEILINGS WILL PERSIST INTO MIDDAY THURSDAY. WINDS WILL BE WESTERLY AROUND 10 KNOTS. .OUTLOOK... THUR AFTN TO FRI NGT...OCNL RESTRICTIONS IN -SHSN/FLRYS THROUGHOUT THIS PD...MAINLY FOR THE CNY TERMINALS. SAT TO SUN AM...MAINLY VFR. SUN AFTN TO EVE...MVFR POSSIBLE IN RAIN SHOWERS. LATE SUN NGT TO MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP/PVN SHORT TERM...MDP LONG TERM...TAC AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
411 PM EDT WED MAR 27 2013 .SYNOPSIS... A COLD NORTHWEST FLOW WILL PERSIST THROUGH THE REMAINDER OF THE WORK WEEK...OCCASIONALLY BRINGING SCATTERED SNOW AND RAIN SHOWERS. TEMPERATURES WILL FINALLY BUT BRIEFLY TURN SLIGHTLY MILDER OVER THE WEEKEND...AND THEN WE WILL RETURN TO A COOL UNSETTLED PATTERN. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 4 PM UPDATE... QUICK UPDATE TO EXPAND 50 POPS ACRS MOST OF THE CWA WITH EXCEPTION OF NERN CNTYS AS THEY RMN UNDER SUBSIDENCE AFT FIRST S/WV PASSED BY. EXPECT SNOW SHOWERS TO WEAKEN BY 00Z TNGT BFR RE-DVLPNG AFT MIDNIGHT AS MAIN UL TROF DROPS THRU AND REGENERATES POPS. 130 PM UPDATE... WEAK WAVE IS DROPPING OVER THE REGION WHICH WITH DIURNAL HEATING IS CAUSING EXPECTED BLOSSOM OF SCATTERED RAIN/SNOW SHOWERS AND SPRINKLES/FLURRIES. AS PER LOCAL HIGH RESOLUTION MODELS...WE ARE HAVING A RELATIVE MAXIMUM IN DIURNAL ACTIVITY ACROSS THE CENTRAL TO SOUTHWESTERN ZONES COMPARED TO THE NORTHEAST. SUBSIDENCE AND DRIER COLUMN THIS AFTERNOON/EARLY EVENING BEHIND WAVE IN THE NORTHEASTERN ZONES INCLUDING MOHAWK VALLEY AND NY THRUWAY...SHOULD LEAD TO RELATIVE MINIMUM IN ACTIVITY THERE...BEFORE BETTER WAVE DROPS IN LATER TONIGHT. FORECAST DETAILS HAVE BEEN ADJUSTED ACCORDINGLY. RUC/RAP SOUNDINGS HAVE STEEPER LAPSE RATES AND THUS MORE INSTABILITY COMPARED TO THE NAM. GIVEN THAT MAV AND ESPECIALLY MET GUIDANCE HAVE BEEN TOO COLD LATELY...AND THE EXTRA ENERGY FROM EARLY SUNSHINE TODAY...THE MORE UNSTABLE RUC SOUNDINGS ARE A BETTER REPRESENTATION. CONVECTIVE NATURE TO THE SCATTERED SHOWERS ARE THUS BEING REALIZED AS CAN BE SEEN ON THE RADAR THE LAST HOUR OR SO...COMPLETE WITH BURSTS OF GRAUPEL. ALSO...MET GUIDANCE AGAIN HAS BEEN SHOWN TO BE MUCH TOO COOL FOR TEMPERATURES THIS AFTERNOON. AFTER DIURNAL ACTIVITY WANES LATE AFTERNOON INTO EVENING...A BETTER UPPER TROUGH WILL DROP NORTH TO SOUTH 03Z-09Z OVERNIGHT...ALLOWING SCATTERED SNOW SHOWERS TO REDEVELOP...ESPECIALLY CENTRAL NY. THAT BEING SAID...ACCUMULATIONS WILL BE GENERALLY ONLY A FEW TO SEVERAL TENTHS OF AN INCH FOR MOST LOCATIONS. WITH AMOUNT OF CLOUDS OVERNIGHT...NOT FIGURING ON MUCH RADIATIONAL COOLING AND SO NEAR OR SLIGHTLY ABOVE BLENDED GUIDANCE IS EXPECTED FOR LOW TEMPERATURES /MID 20S TO AROUND 30/. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... 230 PM UPDATE... MAIN UPPER TROUGH AXIS WILL FINISH EXITING SOUTH THURSDAY MORNING. MODELS SUGGEST THAT A WEAKER SHORTWAVE WILL STILL SLIP THROUGH DURING THE DAY. HOWEVER...THICKNESSES WILL BE A GOOD 5 OR SO DECAMETERS HIGHER...AND SO LAPSE RATES WILL NOT BE AS STEEP. AS DIURNAL ENERGY AGAIN TRIES TO BURP UP SCATTERED SHOWERS...THERE WILL NOT BE AS MUCH INSTABILITY COMPARED TO 24 HOURS PRIOR...AND RIDGING WILL ALREADY BE INITIATING ALOFT. I ONLY PLACED SLIGHT TO LOW CHANCE POPS...AND MAINLY UP TO MIDDAY...FOR DIURNAL ENHANCEMENT AND PASSING WAVE. AS WITH RECENT DAYS...I HAVE STAYED ON WARM SIDE OF MODEL GUIDANCE FOR HIGH TEMPERATURES THURSDAY...ESPECIALLY THE MAV WHICH HAS BEEN MUCH TOO COOL LATELY. MAINLY 40S AREAWIDE. WETBULBING AGAIN WILL ALLOW SNOW OR GRAUPEL WITHIN THE SHOWERS DESPITE TEMPERATURES GETTING WELL ABOVE FREEZING. WEAK RIDGING THURSDAY EVENING...WILL GIVE WAY TO ANOTHER WEAK TROUGH THAT WILL DIP INTO THE AREA FRIDAY...THOUGH FOR THE FIRST TIME IN QUITE AWHILE...NOT ONE ASSOCIATED WITH THE RESIDENT UPPER LOW IN THE CANADIAN MARITIMES. MOISTURE WILL BE FAIRLY SHALLOW...YET LAPSE RATES ALSO STEEPER. THUS WITH THE PASSING FEATURE...DIURNAL INSTABILITY WILL PROBABLY HELP TO REALIZE ADDITIONAL SCATTERED RAIN/SNOW SHOWERS. BY SATURDAY...CYCLONIC FLOW WILL GIVE WAY TO A BETTER RIDGE ON ITS WAY IN. MOISTURE GETS VERY SHALLOW AS WARM AIR ADVECTION ENSUES ALOFT. FIGURING ON A DRY NEAR CLIMATOLOGY DAY WITH STRATOCUMULUS BECOME MORE CELLULAR AND THEN SCATTERING OUT. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... 2 PM UPDATE... FOLLOWED WPC GUIDANCE. A BRIEF BREAK IN THE COLD SAT NGT TO SUNDAY WITH SFC HIGH PRESSURE AND AN UL RIDGE. A COLD FRONT GOES THROUGH SUN AFTN AND EVE WITH MOSTLY RAIN...WHICH MAY CHANGE TO SNOW BEFORE ENDING. ANOTHER BREAK LATE SUN NGT TO MON BEFORE COLDER AIR COMES IN MON NGT WITH SNOW...A COLD FRONT AND STRONG SHORT WAVE. THE LOW LEVEL FLOW SHIFTS TO NW BEHIND THE FRONT SO SNOW SHOWERS FOR TUES AND WED. COOLER THAN NORMAL WITH A DEEP UPPER LEVEL TROF IN THE NE US. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... 130 PM UPDATE... VFR THIS AFTN...THEN FALLING TO MVFR CIGS AND MAYBE VSBYS TONIGHT WITH ADDITIONAL MOISTURE AND SNOW SHOWERS. BECOMING MVFR BETWEEN 2 AND 6Z EVERYWHERE. WITH NW LOW LEVEL FLOW AND WEAK LAKE ENHANCEMENT TO ADD TO THE WEAK SYNOPTIC FORCING MVFR CONDITIONS WILL SLOWLY IMPROVE THU MORNING BETWEEN 14 AND 16Z. WEST TO WEST-NORTHWEST WINDS AROUND 10 KTS WITH GUSTS TO 15 TO 20 KTS THIS AFTN. W TO NW WINDS AROUND 5 KTS TONIGHT. THU W TO NW AT 8 TO 10 KTS. .OUTLOOK... THUR AFTN TO FRI NGT...OCNL RESTRICTIONS IN -SHSN/FLRYS THROUGHOUT THIS PD...MAINLY FOR THE CNY TERMINALS. SAT TO SUN AM...MAINLY VFR. SUN AFTN TO EVE...MVFR POSSIBLE IN RAIN SHOWERS. LATE SUN NGT TO MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP/PVN SHORT TERM...MDP LONG TERM...TAC AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
356 PM EDT WED MAR 27 2013 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE REGION THIS EVENING THROUGH EARLY THURSDAY...BRINGING SOME RAIN AND SNOW SHOWERS TO THE NORTH COUNTRY. A LIGHT SNOW ACCUMULATION WILL BE POSSIBLE TONIGHT...ESPECIALLY IN THE MOUNTAINS. ANOTHER TROUGH OF LOW PRESSURE WILL MOVE SOUTHEAST FROM CANADA ON FRIDAY...BRINGING A CHANCE OF RAIN AND SNOW SHOWERS TO THE REGION. TEMPERATURES WILL CONTINUE TO BE AT OR SLIGHTLY BELOW NORMAL FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 107 PM EDT WEDNESDAY...BUMPED UP TEMPS EARLY THIS AFTERNOON BUT CLOUD COVER MOVING IN FROM THE NORTHEAST WILL KEEP TEMPS FROM GETTING MUCH WARMER THAN 45 TO 50 WHICH IS WHERE WE ARE NOW. RAP SOUNDINGS SHOW SUPER ADIABATIC LAPSE RATES LIKELY DUE TO THE BROWN GROUND ESPECIALLY IN THE CHAMPLAIN VALLEY. WE`LL LOSE THIS WITH THE INCREASE IN CLOUDS. A WEAK BACKDOOR WARM FRONT WILL BE DROPPING INTO THE FORECAST AREA FROM THE NORTHEAST LATER THIS AFTERNOON AND OVERNIGHT. NOT EXPECTING TO SEE MUCH IN THE WAY OF PRECIPITATION DURING THE DAYLIGHT HOURS EXCEPT FOR THE FAR NEK. FOR BTV RAP SIMULATED REFLECTIVITY SUGGESTS BEST CHANCES OF SHOWERS AFTER 00Z. IT SHOULD END UP BEING A FAIRLY NICE SPRING DAY WITH MAX TEMPS ABOUT 5 DEGREES ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/... AS OF 455 AM EDT WEDNESDAY...MOISTURE OVER NORTHERN MAINE AT THIS TIME WILL MOVE INTO THE REGION TONIGHT. HAVE GONE WITH LIKELY POPS ACROSS THE NORTHERN PORTION OF THE FORECAST AREA. CONDITIONS WILL BE WARM ENOUGH INITIALLY SO THAT PRECIPITATION WILL BEGIN AS RAIN IN VALLEY LOCATIONS BEFORE CHANGING TO SNOW. EXPECTING 1 TO 3 INCHES OF SNOW BY DAYBREAK THURSDAY ACROSS THE ADIRONDACKS AND GREEN MOUNTAINS...WITH A DUSTING TO 2 INCHES IN VALLEY LOCATIONS. EXPECTING PRECIPITATION TO DIMINISH THURSDAY MORNING...AS MODELS SHOW AN UPPER RIDGE AT 500 MB BUILDING INTO THE REGION BY THURSDAY AFTERNOON THAT WILL REMAIN THROUGH THURSDAY NIGHT. A WEAK UPPER SHORTWAVE WILL MOVE SOUTHEAST FROM CANADA ON FRIDAY...BRINGING ANOTHER CHANCE OF SHOWERS TO THE REGION. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 356 PM EDT WEDNESDAY...LINGERING SNOW SHOWERS SATURDAY MORNING...MAINLY OVER THE MTNS WILL DISSIPATE THROUGHOUT THE DAY AS HIGH PRESSURE TO OUR SOUTH...ACCOMPANIED BY SOME UPPER LEVEL RIDGING SETTLES IN FOR SATURDAY AND SATURDAY NIGHT. THE HIGH WILL BE PUSHED OFF SHORE ON SUNDAY AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST. TRACK OF THIS SYSTEM STILL UNCERTAIN IN MODEL GUIDANCE...BUT RECENT MODEL RUNS HAVE BEEN STEADY WITH SOUTHERLY FLOW AHEAD OF A COLD FRONT THAT WILL BRING PRECIP INTO THE NORTH COUNTRY LATE SUNDAY THROUGH AT LEAST MONDAY NIGHT. SOUTHERLY FLOW WILL SHIFT SE...ALLOWING FOR ENHANCED PRECIP AMOUNTS ON THE EASTERN SLOPES SUNDAY NIGHT. AFOREMENTIONED SOUTHERLY FLOW WILL KEEP TEMPS WARM SATURDAY THROUGH MONDAY NIGHT...RESULTING IN RAIN LATE SUNDAY INTO SUNDAY NIGHT...CHANGING OVER TO SNOW ACROSS THE HIGH TRN. RAIN EXPECTED FOR THE FIRST HALF OF MONDAY AS COLD AIR WILL BEGIN TO FILTER INTO THE REGION LATE MONDAY BEHIND THE FRONT WITH WINDS SHIFTING SW-W...ALLOWING PRECIP TO CHANGE TO ALL SNOW MONDAY NIGHT. THREAT FOR SNOW WILL CONTINUE AS ADDITIONAL VORTICITY ROTATES ABOUT THE CLOSED UPPER LOW ASSOCIATED WITH THIS SYSTEM. ABOVE NORMAL TEMPS WITH VALLEYS REACHING L50S BY SUNDAY WILL COOL TO THE U30S ON TUESDAY. MIN TEMPS ABOVE NORMAL IN THE 20S TO NEAR 30 SATURDAY NIGHT WARMING INTO THE U20S-U30S SUNDAY NIGHT WILL COOL TO NEAR NORMAL MONDAY NIGHT AND SLIGHTLY BELOW NORMAL TUESDAY NIGHT. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...VFR CONDITIONS WILL DETERIORATE TO MVFR CONDITIONS LATE THIS AFTERNOON AND OVERNIGHT. NE FLOW ALOFT WILL CONTINUE TO GRADUALLY BRING CLOUDS AND EVENTUALLY INCREASED MOISTURE ACROSS THE NORTH COUNTRY FROM NE TO SW. NW FLOW AT THE SFC MAY HELP SLGTLY TO IMPEDE MOISTENING IN THE LOW LEVELS. VCSH THIS AFTN EXPECTED TO INCREASE TO -SHSN/-RASN AS VORTICITY AND TROUGH MOVE FROM NE TO SW ACROSS THE REGION. WITHIN THESE SHOWERS...EXPECT VFR CIGS TO DECREASE TO MVFR...WITH VSBYS FOLLOWING: MPV AT 21Z...PBG/BTV/MSS/SLK BTWN 00Z-03Z...AND RUT AT 05Z. CONDITIONS WILL GRADUALLY IMPROVE THURSDAY MORNING. WINDS MAINLY OUT OF NW-N AROUND 10 KTS...GUSTY UP TO 25KTS AT TIMES THIS AFTN WILL SUBSIDE TO 5-10 KTS OVERNIGHT THROUGH LATE THURSDAY MORNING/EARLY AFTN. OUTLOOK 18Z THURSDAY THROUGH MONDAY... 18Z THURSDAY THROUGH 12Z SATURDAY...GENERALLY VFR WITH PSBL MVFR IN -SHSN IN THE MTNS FRIDAY/FRIDAY NIGHT. 12Z SATURDAY THROUGH 18Z SUNDAY...WIDESPREAD VFR CONDITIONS IN HIGH PRESSURE. 18Z SUNDAY ONWARD...POSSIBLE MVFR CONDITIONS IN SHRA AND SHSN. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...SISSON SHORT TERM...WGH LONG TERM...KGM AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
242 PM EDT WED MAR 27 2013 .SYNOPSIS... A COLD NORTHWEST FLOW WILL PERSIST THROUGH THE REMAINDER OF THE WORK WEEK...OCCASIONALLY BRINGING SCATTERED SNOW AND RAIN SHOWERS. TEMPERATURES WILL FINALLY BUT BRIEFLY TURN SLIGHTLY MILDER OVER THE WEEKEND...AND THEN WE WILL RETURN TO A COOL UNSETTLED PATTERN. && .NEAR TERM /THROUGH TONIGHT/... 130 PM UPDATE... WEAK WAVE IS DROPPING OVER THE REGION WHICH WITH DIURNAL HEATING IS CAUSING EXPECTED BLOSSOM OF SCATTERED RAIN/SNOW SHOWERS AND SPRINKLES/FLURRIES. AS PER LOCAL HIGH RESOLUTION MODELS...WE ARE HAVING A RELATIVE MAXIMUM IN DIURNAL ACTIVITY ACROSS THE CENTRAL TO SOUTHWESTERN ZONES COMPARED TO THE NORTHEAST. SUBSIDENCE AND DRIER COLUMN THIS AFTERNOON/EARLY EVENING BEHIND WAVE IN THE NORTHEASTERN ZONES INCLUDING MOHAWK VALLEY AND NY THRUWAY...SHOULD LEAD TO RELATIVE MINIMUM IN ACTIVITY THERE...BEFORE BETTER WAVE DROPS IN LATER TONIGHT. FORECAST DETAILS HAVE BEEN ADJUSTED ACCORDINGLY. RUC/RAP SOUNDINGS HAVE STEEPER LAPSE RATES AND THUS MORE INSTABILITY COMPARED TO THE NAM. GIVEN THAT MAV AND ESPECIALLY MET GUIDANCE HAVE BEEN TOO COLD LATELY...AND THE EXTRA ENERGY FROM EARLY SUNSHINE TODAY...THE MORE UNSTABLE RUC SOUNDINGS ARE A BETTER REPRESENTATION. CONVECTIVE NATURE TO THE SCATTERED SHOWERS ARE THUS BEING REALIZED AS CAN BE SEEN ON THE RADAR THE LAST HOUR OR SO...COMPLETE WITH BURSTS OF GRAUPEL. ALSO...MET GUIDANCE AGAIN HAS BEEN SHOWN TO BE MUCH TOO COOL FOR TEMPERATURES THIS AFTERNOON. AFTER DIURNAL ACTIVITY WANES LATE AFTERNOON INTO EVENING...A BETTER UPPER TROUGH WILL DROP NORTH TO SOUTH 03Z-09Z OVERNIGHT...ALLOWING SCATTERED SNOW SHOWERS TO REDEVELOP...ESPECIALLY CENTRAL NY. THAT BEING SAID...ACCUMULATIONS WILL BE GENERALLY ONLY A FEW TO SEVERAL TENTHS OF AN INCH FOR MOST LOCATIONS. WITH AMOUNT OF CLOUDS OVERNIGHT...NOT FIGURING ON MUCH RADIATIONAL COOLING AND SO NEAR OR SLIGHTLY ABOVE BLENDED GUIDANCE IS EXPECTED FOR LOW TEMPERATURES /MID 20S TO AROUND 30/. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... 230 PM UPDATE... MAIN UPPER TROUGH AXIS WILL FINISH EXITING SOUTH THURSDAY MORNING. MODELS SUGGEST THAT A WEAKER SHORTWAVE WILL STILL SLIP THROUGH DURING THE DAY. HOWEVER...THICKNESSES WILL BE A GOOD 5 OR SO DECAMETERS HIGHER...AND SO LAPSE RATES WILL NOT BE AS STEEP. AS DIURNAL ENERGY AGAIN TRIES TO BURP UP SCATTERED SHOWERS...THERE WILL NOT BE AS MUCH INSTABILITY COMPARED TO 24 HOURS PRIOR...AND RIDGING WILL ALREADY BE INITIATING ALOFT. I ONLY PLACED SLIGHT TO LOW CHANCE POPS...AND MAINLY UP TO MIDDAY...FOR DIURNAL ENHANCEMENT AND PASSING WAVE. AS WITH RECENT DAYS...I HAVE STAYED ON WARM SIDE OF MODEL GUIDANCE FOR HIGH TEMPERATURES THURSDAY...ESPECIALLY THE MAV WHICH HAS BEEN MUCH TOO COOL LATELY. MAINLY 40S AREAWIDE. WETBULBING AGAIN WILL ALLOW SNOW OR GRAUPEL WITHIN THE SHOWERS DESPITE TEMPERATURES GETTING WELL ABOVE FREEZING. WEAK RIDGING THURSDAY EVENING...WILL GIVE WAY TO ANOTHER WEAK TROUGH THAT WILL DIP INTO THE AREA FRIDAY...THOUGH FOR THE FIRST TIME IN QUITE AWHILE...NOT ONE ASSOCIATED WITH THE RESIDENT UPPER LOW IN THE CANADIAN MARITIMES. MOISTURE WILL BE FAIRLY SHALLOW...YET LAPSE RATES ALSO STEEPER. THUS WITH THE PASSING FEATURE...DIURNAL INSTABILITY WILL PROBABLY HELP TO REALIZE ADDITIONAL SCATTERED RAIN/SNOW SHOWERS. BY SATURDAY...CYCLONIC FLOW WILL GIVE WAY TO A BETTER RIDGE ON ITS WAY IN. MOISTURE GETS VERY SHALLOW AS WARM AIR ADVECTION ENSUES ALOFT. FIGURING ON A DRY NEAR CLIMATOLOGY DAY WITH STRATOCUMULUS BECOME MORE CELLULAR AND THEN SCATTERING OUT. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... 2 PM UPDATE... FOLLOWED WPC GUIDANCE. A BRIEF BREAK IN THE COLD SAT NGT TO SUNDAY WITH SFC HIGH PRESSURE AND AN UL RIDGE. A COLD FRONT GOES THROUGH SUN AFTN AND EVE WITH MOSTLY RAIN...WHICH MAY CHANGE TO SNOW BEFORE ENDING. ANOTHER BREAK LATE SUN NGT TO MON BEFORE COLDER AIR COMES IN MON NGT WITH SNOW...A COLD FRONT AND STRONG SHORT WAVE. THE LOW LEVEL FLOW SHIFTS TO NW BEHIND THE FRONT SO SNOW SHOWERS FOR TUES AND WED. COOLER THAN NORMAL WITH A DEEP UPPER LEVEL TROF IN THE NE US. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... 130 PM UPDATE... VFR THIS AFTN...THEN FALLING TO MVFR CIGS AND MAYBE VSBYS TONIGHT WITH ADDITIONAL MOISTURE AND SNOW SHOWERS. BECOMING MVFR BETWEEN 2 AND 6Z EVERYWHERE. WITH NW LOW LEVEL FLOW AND WEAK LAKE ENHANCEMENT TO ADD TO THE WEAK SYNOPTIC FORCING MVFR CONDITIONS WILL SLOWLY IMPROVE THU MORNING BETWEEN 14 AND 16Z. WEST TO WEST-NORTHWEST WINDS AROUND 10 KTS WITH GUSTS TO 15 TO 20 KTS THIS AFTN. W TO NW WINDS AROUND 5 KTS TONIGHT. THU W TO NW AT 8 TO 10 KTS. .OUTLOOK... THUR AFTN TO FRI NGT...OCNL RESTRICTIONS IN -SHSN/FLRYS THROUGHOUT THIS PD...MAINLY FOR THE CNY TERMINALS. SAT TO SUN AM...MAINLY VFR. SUN AFTN TO EVE...MVFR POSSIBLE IN RAIN SHOWERS. LATE SUN NGT TO MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP SHORT TERM...MDP LONG TERM...TAC AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
204 PM EDT WED MAR 27 2013 .SYNOPSIS... A COLD NORTHWEST FLOW WILL PERSIST THROUGH THE REMAINDER OF THE WORK WEEK...OCCASIONALLY BRINGING SCATTERED SNOW AND RAIN SHOWERS. TEMPERATURES WILL FINALLY BUT BRIEFLY TURN SLIGHTLY MILDER OVER THE WEEKEND...AND THEN WE WILL RETURN TO A COOL UNSETTLED PATTERN. && .NEAR TERM /THROUGH TONIGHT/... 130 PM UPDATE... WEAK WAVE IS DROPPING OVER THE REGION WHICH WITH DIURNAL HEATING IS CAUSING EXPECTED BLOSSOM OF SCATTERED RAIN/SNOW SHOWERS AND SPRINKLES/FLURRIES. AS PER LOCAL HIGH RESOLUTION MODELS...WE ARE HAVING A RELATIVE MAXIMUM IN DIURNAL ACTIVITY ACROSS THE CENTRAL TO SOUTHWESTERN ZONES COMPARED TO THE NORTHEAST. SUBSIDENCE AND DRIER COLUMN THIS AFTERNOON/EARLY EVENING BEHIND WAVE IN THE NORTHEASTERN ZONES INCLUDING MOHAWK VALLEY AND NY THRUWAY...SHOULD LEAD TO RELATIVE MINIMUM IN ACTIVITY THERE...BEFORE BETTER WAVE DROPS IN LATER TONIGHT. FORECAST DETAILS HAVE BEEN ADJUSTED ACCORDINGLY. RUC/RAP SOUNDINGS HAVE STEEPER LAPSE RATES AND THUS MORE INSTABILITY COMPARED TO THE NAM. GIVEN THAT MAV AND ESPECIALLY MET GUIDANCE HAVE BEEN TOO COLD LATELY...AND THE EXTRA ENERGY FROM EARLY SUNSHINE TODAY...THE MORE UNSTABLE RUC SOUNDINGS ARE A BETTER REPRESENTATION. CONVECTIVE NATURE TO THE SCATTERED SHOWERS ARE THUS BEING REALIZED AS CAN BE SEEN ON THE RADAR THE LAST HOUR OR SO...COMPLETE WITH BURSTS OF GRAUPEL. ALSO...MET GUIDANCE AGAIN HAS BEEN SHOWN TO BE MUCH TOO COOL FOR TEMPERATURES THIS AFTERNOON. AFTER DIURNAL ACTIVITY WANES LATE AFTERNOON INTO EVENING...A BETTER UPPER TROUGH WILL DROP NORTH TO SOUTH 03Z-09Z OVERNIGHT...ALLOWING SCATTERED SNOW SHOWERS TO REDEVELOP...ESPECIALLY CENTRAL NY. THAT BEING SAID...ACCUMULATIONS WILL BE GENERALLY ONLY A FEW TO SEVERAL TENTHS OF AN INCH FOR MOST LOCATIONS. WITH AMOUNT OF CLOUDS OVERNIGHT...NOT FIGURING ON MUCH RADIATIONAL COOLING AND SO NEAR OR SLIGHTLY ABOVE BLENDED GUIDANCE IS EXPECTED FOR LOW TEMPERATURES /MID 20S TO AROUND 30/. && .SHORT TERM /THURSDAY THROUGH SATURDAY/... UPPER LEVEL TROF WILL REMAIN OVER THE NORTHEAST THROUGH THIS PERIOD BRINGING A CONTINUATION OF COOL WEATHER ALONG WITH SCATTERED FLURRIES, SPRINKLES AND LIGHT SNOW SHOWERS. SKIES WILL BE PRIMARILY PARTLY CLOUDY DURING THE OVERNIGHT PERIODS AND PARTLY TO MOSTLY CLOUDY DURING THE DAY. TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS IN THE UPPER 30S TO MID 40S AND LOWS IN THE MID 20S TO AROUND 30. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... 2 PM UPDATE... FOLLOWED WPC GUIDANCE. A BRIEF BREAK IN THE COLD SAT NGT TO SUNDAY WITH SFC HIGH PRESSURE AND AN UL RIDGE. A COLD FRONT GOES THROUGH SUN AFTN AND EVE WITH MOSTLY RAIN...WHICH MAY CHANGE TO SNOW BEFORE ENDING. ANOTHER BREAK LATE SUN NGT TO MON BEFORE COLDER AIR COMES IN MON NGT WITH SNOW...A COLD FRONT AND STRONG SHORT WAVE. THE LOW LEVEL FLOW SHIFTS TO NW BEHIND THE FRONT SO SNOW SHOWERS FOR TUES AND WED. COOLER THAN NORMAL WITH A DEEP UPPER LEVEL TROF IN THE NE US. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... 130 PM UPDATE... VFR THIS AFTN...THEN FALLING TO MVFR CIGS AND MAYBE VSBYS TONIGHT WITH ADDITIONAL MOISTURE AND SNOW SHOWERS. BECOMING MVFR BETWEEN 2 AND 6Z EVERYWHERE. WITH NW LOW LEVEL FLOW AND WEAK LAKE ENHANCEMENT TO ADD TO THE WEAK SYNOPTIC FORCING MVFR CONDITIONS WILL SLOWLY IMPROVE THU MORNING BETWEEN 14 AND 16Z. WEST TO WEST-NORTHWEST WINDS AROUND 10 KTS WITH GUSTS TO 15 TO 20 KTS THIS AFTN. W TO NW WINDS AROUND 5 KTS TONIGHT. THU W TO NW AT 8 TO 10 KTS. .OUTLOOK... THUR AFTN TO FRI NGT...OCNL RESTRICTIONS IN -SHSN/FLRYS THROUGHOUT THIS PD...MAINLY FOR THE CNY TERMINALS. SAT TO SUN AM...MAINLY VFR. SUN AFTN TO EVE...MVFR POSSIBLE IN RAIN SHOWERS. LATE SUN NGT TO MON...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP SHORT TERM...RRM LONG TERM...TAC AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
201 PM EDT WED MAR 27 2013 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE REGION THIS EVENING THROUGH EARLY THURSDAY...BRINGING SOME RAIN AND SNOW SHOWERS TO THE NORTH COUNTRY. A LIGHT SNOW ACCUMULATION WILL BE POSSIBLE TONIGHT...ESPECIALLY IN THE MOUNTAINS. ANOTHER TROUGH OF LOW PRESSURE WILL MOVE SOUTHEAST FROM CANADA ON FRIDAY...BRINGING A CHANCE OF RAIN AND SNOW SHOWERS TO THE REGION. TEMPERATURES WILL CONTINUE TO BE AT OR SLIGHTLY BELOW NORMAL FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 107 PM EDT WEDNESDAY...BUMPED UP TEMPS EARLY THIS AFTERNOON BUT CLOUD COVER MOVING IN FROM THE NORTHEAST WILL KEEP TEMPS FROM GETTING MUCH WARMER THAN 45 TO 50 WHICH IS WHERE WE ARE NOW. RAP SOUNDINGS SHOW SUPER ADIABATIC LAPSE RATES LIKELY DUE TO THE BROWN GROUND ESPECIALLY IN THE CHAMPLAIN VALLEY. WE`LL LOSE THIS WITH THE INCREASE IN CLOUDS. A WEAK BACKDOOR WARM FRONT WILL BE DROPPING INTO THE FORECAST AREA FROM THE NORTHEAST LATER THIS AFTERNOON AND OVERNIGHT. NOT EXPECTING TO SEE MUCH IN THE WAY OF PRECIPITATION DURING THE DAYLIGHT HOURS EXCEPT FOR THE FAR NEK. FOR BTV RAP SIMULATED REFLECTIVITY SUGGESTS BEST CHANCES OF SHOWERS AFTER 00Z. IT SHOULD END UP BEING A FAIRLY NICE SPRING DAY WITH MAX TEMPS ABOUT 5 DEGREES ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AS OF 455 AM EDT WEDNESDAY...MOISTURE OVER NORTHERN MAINE AT THIS TIME WILL MOVE INTO THE REGION TONIGHT. HAVE GONE WITH LIKELY POPS ACROSS THE NORTHERN PORTION OF THE FORECAST AREA. CONDITIONS WILL BE WARM ENOUGH INITIALLY SO THAT PRECIPITATION WILL BEGIN AS RAIN IN VALLEY LOCATIONS BEFORE CHANGING TO SNOW. EXPECTING 1 TO 3 INCHES OF SNOW BY DAYBREAK THURSDAY ACROSS THE ADIRONDACKS AND GREEN MOUNTAINS...WITH A DUSTING TO 2 INCHES IN VALLEY LOCATIONS. EXPECTING PRECIPITATION TO DIMINISH THURSDAY MORNING...AS MODELS SHOW AN UPPER RIDGE AT 500 MB BUILDING INTO THE REGION BY THURSDAY AFTERNOON THAT WILL REMAIN THROUGH THURSDAY NIGHT. A WEAK UPPER SHORTWAVE WILL MOVE SOUTHEAST FROM CANADA ON FRIDAY...BRINGING ANOTHER CHANCE OF SHOWERS TO THE REGION. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 345 AM EDT WEDNESDAY...WEAK UPPER LEVEL TROUGH MOVING ACROSS THE NORTH COUNTRY WITH NW FLOW IN PLACE THEREFORE HAVE MENTIONED CHANCE FOR MOUNTAIN SNOW SHOWERS FRIDAY NIGHT. HIGH PRESSURE AT THE SFC BUILDING OVER THE OHIO VALLEY ON SATURDAY WILL LEAD TO DRY CONDITIONS FOR SATURDAY AND SATURDAY NIGHT. LOW PRESSURE OVER THE GREAT LAKES REGION ON SUNDAY MORNING WILL TRACK NORTHEASTWARD TOWARDS THE SAINT LAWRENCE VALLEY BY ABOUT 00Z MONDAY. THEREFORE HAVE MENTIONED CHANCE FOR RAIN ACROSS OUR FAR WESTERN ZONES. LOW WILL TRACK WELL NORTH OF OUR FORECAST AREA...AND COLD FRONT CROSSES OUR CWA MONDAY NIGHT CHANGING RAIN OVER TO SNOW...THOUGH BULK OF DEEP LAYER MOISTURE WILL ALSO BE SHUNTED EAST OF OUR FORECAST AREA BY 12Z MONDAY. GUSTY WINDS WILL TRAIL THE COLD FRONT WITH STRONG PRESSURE GRADIENT. LARGE CLOSED UPPER LOW WILL LAG BEHIND THE SURFACE FEATURE...SLOWLY TRACKING ACROSS OUR FORECAST AREA MONDAY AFTERNOON AND OVERNIGHT. SEVERAL VORT MAXES ROTATE AROUND THIS LOW/TROF...SO WILL PROBABLY SEE SOME LINGERING SHOWERS. ANOTHER SURFACE HIGH WILL RIDGE INTO THE NORTH COUNTRY TOWARDS THE MIDDLE OF THE WEEK. TEMPERATURES IN THE EXTENDED WILL START OUT ABOVE NORMAL WITH ABUNDANT CLOUD COVER...THOUGH TRENDS BACK BELOW NORMAL AGAIN FOLLOWING COLD FROPA AND THEN COLD HIGH PRESSURE RIDGING INTO THE REGION OUT OF CANADA. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...VFR CONDITIONS WILL DETERIORATE TO MVFR CONDITIONS LATE THIS AFTERNOON AND OVERNIGHT. NE FLOW ALOFT WILL CONTINUE TO GRADUALLY BRING CLOUDS AND EVENTUALLY INCREASED MOISTURE ACROSS THE NORTH COUNTRY FROM NE TO SW. NW FLOW AT THE SFC MAY HELP SLGTLY TO IMPEDE MOISTENING IN THE LOW LEVELS. VCSH THIS AFTN EXPECTED TO INCREASE TO -SHSN/-RASN AS VORTICITY AND TROUGH MOVE FROM NE TO SW ACROSS THE REGION. WITHIN THESE SHOWERS...EXPECT VFR CIGS TO DECREASE TO MVFR...WITH VSBYS FOLLOWING: MPV AT 21Z...PBG/BTV/MSS/SLK BTWN 00Z-03Z...AND RUT AT 05Z. CONDITIONS WILL GRADUALLY IMPROVE THURSDAY MORNING. WINDS MAINLY OUT OF NW-N AROUND 10 KTS...GUSTY UP TO 25KTS AT TIMES THIS AFTN WILL SUBSIDE TO 5-10 KTS OVERNIGHT THROUGH LATE THURSDAY MORNING/EARLY AFTN. OUTLOOK 18Z THURSDAY THROUGH MONDAY... 18Z THURSDAY THROUGH 12Z SATURDAY...GENERALLY VFR WITH PSBL MVFR IN -SHSN IN THE MTNS FRIDAY/FRIDAY NIGHT. 12Z SATURDAY THROUGH 18Z SUNDAY...WIDESPREAD VFR CONDITIONS IN HIGH PRESSURE. 18Z SUNDAY ONWARD...POSSIBLE MVFR CONDITIONS IN SHRA AND SHSN. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...SISSON SHORT TERM...WGH LONG TERM...NEILES AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
132 PM EDT WED MAR 27 2013 .SYNOPSIS... A COLD NORTHWEST FLOW WILL PERSIST THROUGH THE REMAINDER OF THE WORK WEEK...OCCASIONALLY BRINGING SCATTERED SNOW AND RAIN SHOWERS. TEMPERATURES WILL FINALLY BUT BRIEFLY TURN SLIGHTLY MILDER OVER THE WEEKEND...AND THEN WE WILL RETURN TO A COOL UNSETTLED PATTERN. && .NEAR TERM /THROUGH TONIGHT/... 130 PM UPDATE... WEAK WAVE IS DROPPING OVER THE REGION WHICH WITH DIURNAL HEATING IS CAUSING EXPECTED BLOSSOM OF SCATTERED RAIN/SNOW SHOWERS AND SPRINKLES/FLURRIES. AS PER LOCAL HIGH RESOLUTION MODELS...WE ARE HAVING A RELATIVE MAXIMUM IN DIURNAL ACTIVITY ACROSS THE CENTRAL TO SOUTHWESTERN ZONES COMPARED TO THE NORTHEAST. SUBSIDENCE AND DRIER COLUMN THIS AFTERNOON/EARLY EVENING BEHIND WAVE IN THE NORTHEASTERN ZONES INCLUDING MOHAWK VALLEY AND NY THRUWAY...SHOULD LEAD TO RELATIVE MINIMUM IN ACTIVITY THERE...BEFORE BETTER WAVE DROPS IN LATER TONIGHT. FORECAST DETAILS HAVE BEEN ADJUSTED ACCORDINGLY. RUC/RAP SOUNDINGS HAVE STEEPER LAPSE RATES AND THUS MORE INSTABILITY COMPARED TO THE NAM. GIVEN THAT MAV AND ESPECIALLY MET GUIDANCE HAVE BEEN TOO COLD LATELY...AND THE EXTRA ENERGY FROM EARLY SUNSHINE TODAY...THE MORE UNSTABLE RUC SOUNDINGS ARE A BETTER REPRESENTATION. CONVECTIVE NATURE TO THE SCATTERED SHOWERS ARE THUS BEING REALIZED AS CAN BE SEEN ON THE RADAR THE LAST HOUR OR SO...COMPLETE WITH BURSTS OF GRAUPEL. ALSO...MET GUIDANCE AGAIN HAS BEEN SHOWN TO BE MUCH TOO COOL FOR TEMPERATURES THIS AFTERNOON. AFTER DIURNAL ACTIVITY WANES LATE AFTERNOON INTO EVENING...A BETTER UPPER TROUGH WILL DROP NORTH TO SOUTH 03Z-09Z OVERNIGHT...ALLOWING SCATTERED SNOW SHOWERS TO REDEVELOP...ESPECIALLY CENTRAL NY. THAT BEING SAID...ACCUMULATIONS WILL BE GENERALLY ONLY A FEW TO SEVERAL TENTHS OF AN INCH FOR MOST LOCATIONS. WITH AMOUNT OF CLOUDS OVERNIGHT...NOT FIGURING ON MUCH RADIATIONAL COOLING AND SO NEAR OR SLIGHTLY ABOVE BLENDED GUIDANCE IS EXPECTED FOR LOW TEMPERATURES /MID 20S TO AROUND 30/. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... UPPER LEVEL TROF WILL REMAIN OVER THE NORTHEAST THROUGH THIS PERIOD BRINGING A CONTINUATION OF COOL WEATHER ALONG WITH SCATTERED FLURRIES, SPRINKLES AND LIGHT SNOW SHOWERS. SKIES WILL BE PRIMARILY PARTLY CLOUDY DURING THE OVERNIGHT PERIODS AND PARTLY TO MOSTLY CLOUDY DURING THE DAY. TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS IN THE UPPER 30S TO MID 40S AND LOWS IN THE MID 20S TO AROUND 30. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 330 AM UPDATE...NO BIG CHANGES TO THE GOING FORECAST WITH A DRY FIRST HALF OF THE WEEKEND AND TEMPS IN THE 50S FOR SUNDAY. BUMPED UP POPS SUNDAY NIGHT TO HIGH CHANCE WITH BOTH THE EURO AND GFS IN AGREEMENT ON A COLD FRONTAL PASSAGE. SOME WET SNOW IS POSSIBLE BY MONDAY MORNING BUT IT APPEARS MOST OF THE MOISTURE WILL BE TO OUR EAST BY THE TIME THE COLDER AIR ARRIVES. RAIN AND WET SNOW SHOWERS POSSIBLE FROM LATE MONDAY AFTERNOON THROUGH THE MIDDLE OF NEXT WEEK ALONG WITH BELOW NORMAL TEMPS AS ANOTHER TROF SETS AIM ON OUR AREA. THE PREVIOUS AFD IS BELOW... 330 PM UPDATE...UL BLOCKING WL CONTINUE THRU THE MIDDLE PART OF NEXT WEEK WITH HIGH PRESSURE CNTRD OVR GREENLAND. 12Z GFS AND EURO BRINGS A WEAK S/WV RIDGE INTO AREA 00-12Z SUNDAY, BRINGING A BRIEF END TO THE NEVER-ENDING PCPN. NEXT SYSTEM WL DRAG A CLD FNT TWD CWA ON SUNDAY AFTN AS H5 HGTS APPCH 550 DM, YIELDING HIGHS ARND 50F. LIGHT RAIN WL SPREAD IN SUN NGT THRU MONDAY AND FOR NOW HV GONE WITH HICHC POPS. AS CLD AIR MVS IN BHND SYSTEM A RAIN/SNOW MIX WL OVRSPRD THE REGION. AREA WL BE UNDER INFLUENCE OF UL TROF THRU TUESDAY WITH TEMPS CONTINUING TO RUN BLO NRML. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... 12Z UPDATE... MAINLY VFR THROUGH MIDDAY WITH A MID DECK AROUND 9KFT. LATER THIS AFTERNOON AND EVENING AS A DISTURBANCE IN THE JET STREAM WINDS ALOFT MOVES THROUGH...WE HAVE A BETTER SHOT AT LOWER CIGS AND VSBYS. THE COMBINATION OF THIS ALONG WITH PEAK DAYTIME HEATING LOOKS TO PRODUCE THE BEST SHOT AT SCT. SNOW SHOWERS ACROSS THE SOUTHERN TERMINALS BETWEEN 19Z AND 23Z. DURING THIS TIME BRIEF MVFR VSBYS AND/OR CIGS POSSIBLE IN THE SNOW SHOWERS THEMSELVES. THE DURATION OF MVFR WILL BE BRIEF HOWEVER AND WILL JUST COVER IT WITH A TEMPO GROUP. EARLY THIS EVENING AND INTO TONIGHT...AS THE MOISTURE DEEPENS MORE WIDESPREAD AND LONGER LASTING MVFR CIGS ARE MORE LIKELY AND WILL PREVAIL THEM THROUGH THE OVERNIGHT. WEST TO WEST-NORTHWEST WINDS AROUND 5 KTS THROUGH THIS MORNING. SAME WIND DIRECTION BUT IN THE 5 TO 15 KT RANGE THROUGH LATE AFTERNOON. LIGHT WEST-NORTHWEST WINDS TONIGHT AROUND 5KTS. .OUTLOOK... THUR THROUGH FRI...OCNL RESTRICTIONS IN -SHSN/FLRYS THROUGHOUT THIS PD...MAINLY FOR THE CNY TERMINALS. SAT...MAINLY VFR. SUN...MVFR POSSIBLE LATE IN RAIN SHOWERS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP SHORT TERM...RRM LONG TERM...HEDEN/PVN AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
108 PM EDT WED MAR 27 2013 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE REGION THIS EVENING THROUGH EARLY THURSDAY...BRINGING SOME RAIN AND SNOW SHOWERS TO THE NORTH COUNTRY. A LIGHT SNOW ACCUMULATION WILL BE POSSIBLE TONIGHT...ESPECIALLY IN THE MOUNTAINS. ANOTHER TROUGH OF LOW PRESSURE WILL MOVE SOUTHEAST FROM CANADA ON FRIDAY...BRINGING A CHANCE OF RAIN AND SNOW SHOWERS TO THE REGION. TEMPERATURES WILL CONTINUE TO BE AT OR SLIGHTLY BELOW NORMAL FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 107 PM EDT WEDNESDAY...BUMPED UP TEMPS EARLY THIS AFTERNOON BUT CLOUD COVER MOVING IN FROM THE NORTHEAST WILL KEEP TEMPS FROM GETTING MUCH WARMER THAN 45 TO 50 WHICH IS WHERE WE ARE NOW. RAP SOUNDINGS SHOW SUPER ADIABATIC LAPSE RATES LIKELY DUE TO THE BROWN GROUND ESPECIALLY IN THE CHAMPLAIN VALLEY. WE`LL LOSE THIS WITH THE INCREASE IN CLOUDS. A WEAK BACKDOOR WARM FRONT WILL BE DROPPING INTO THE FORECAST AREA FROM THE NORTHEAST LATER THIS AFTERNOON AND OVERNIGHT. NOT EXPECTING TO SEE MUCH IN THE WAY OF PRECIPITATION DURING THE DAYLIGHT HOURS EXCEPT FOR THE FAR NEK. FOR BTV RAP SIMULATED REFLECTIVITY SUGGESTS BEST CHANCES OF SHOWERS AFTER 00Z. IT SHOULD END UP BEING A FAIRLY NICE SPRING DAY WITH MAX TEMPS ABOUT 5 DEGREES ABOVE NORMAL. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AS OF 455 AM EDT WEDNESDAY...MOISTURE OVER NORTHERN MAINE AT THIS TIME WILL MOVE INTO THE REGION TONIGHT. HAVE GONE WITH LIKELY POPS ACROSS THE NORTHERN PORTION OF THE FORECAST AREA. CONDITIONS WILL BE WARM ENOUGH INITIALLY SO THAT PRECIPITATION WILL BEGIN AS RAIN IN VALLEY LOCATIONS BEFORE CHANGING TO SNOW. EXPECTING 1 TO 3 INCHES OF SNOW BY DAYBREAK THURSDAY ACROSS THE ADIRONDACKS AND GREEN MOUNTAINS...WITH A DUSTING TO 2 INCHES IN VALLEY LOCATIONS. EXPECTING PRECIPITATION TO DIMINISH THURSDAY MORNING...AS MODELS SHOW AN UPPER RIDGE AT 500 MB BUILDING INTO THE REGION BY THURSDAY AFTERNOON THAT WILL REMAIN THROUGH THURSDAY NIGHT. A WEAK UPPER SHORTWAVE WILL MOVE SOUTHEAST FROM CANADA ON FRIDAY...BRINGING ANOTHER CHANCE OF SHOWERS TO THE REGION. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 345 AM EDT WEDNESDAY...WEAK UPPER LEVEL TROUGH MOVING ACROSS THE NORTH COUNTRY WITH NW FLOW IN PLACE THEREFORE HAVE MENTIONED CHANCE FOR MOUNTAIN SNOW SHOWERS FRIDAY NIGHT. HIGH PRESSURE AT THE SFC BUILDING OVER THE OHIO VALLEY ON SATURDAY WILL LEAD TO DRY CONDITIONS FOR SATURDAY AND SATURDAY NIGHT. LOW PRESSURE OVER THE GREAT LAKES REGION ON SUNDAY MORNING WILL TRACK NORTHEASTWARD TOWARDS THE SAINT LAWRENCE VALLEY BY ABOUT 00Z MONDAY. THEREFORE HAVE MENTIONED CHANCE FOR RAIN ACROSS OUR FAR WESTERN ZONES. LOW WILL TRACK WELL NORTH OF OUR FORECAST AREA...AND COLD FRONT CROSSES OUR CWA MONDAY NIGHT CHANGING RAIN OVER TO SNOW...THOUGH BULK OF DEEP LAYER MOISTURE WILL ALSO BE SHUNTED EAST OF OUR FORECAST AREA BY 12Z MONDAY. GUSTY WINDS WILL TRAIL THE COLD FRONT WITH STRONG PRESSURE GRADIENT. LARGE CLOSED UPPER LOW WILL LAG BEHIND THE SURFACE FEATURE...SLOWLY TRACKING ACROSS OUR FORECAST AREA MONDAY AFTERNOON AND OVERNIGHT. SEVERAL VORT MAXES ROTATE AROUND THIS LOW/TROF...SO WILL PROBABLY SEE SOME LINGERING SHOWERS. ANOTHER SURFACE HIGH WILL RIDGE INTO THE NORTH COUNTRY TOWARDS THE MIDDLE OF THE WEEK. TEMPERATURES IN THE EXTENDED WILL START OUT ABOVE NORMAL WITH ABUNDANT CLOUD COVER...THOUGH TRENDS BACK BELOW NORMAL AGAIN FOLLOWING COLD FROPA AND THEN COLD HIGH PRESSURE RIDGING INTO THE REGION OUT OF CANADA. && .AVIATION /17Z WEDNESDAY THROUGH MONDAY/... THROUGH 12Z THURSDAY...MAINLY VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH THE 24 HOUR FORECAST PERIOD. SCT SKY COVER THIS MORNING WITH WINDS 5KTS OR LESS. EXPECT CHANCE FOR SOME RAIN AND SNOW SHOWERS BEGINNING AROUND 21Z AND HAVE MAINLY JUST MENTIONED VCSH AT TAF SITES AT THIS TIME. AS WE GET CLOSER TO THE AFTERNOON HOURS WE WILL BE ABLE TO BETTER TIME THE SHOWERS AND WHICH TERMINALS WILL BE IMPACTED. WINDS WILL INCREASE DURING THE DAY OUT OF THE NORTHWEST AROUND 10 KTS AT ALL SITES. SHOWERS WILL BE ENDING AFTER ABOUT 06Z...THOUGH MAY LINGER LONGEST AT RUTLAND. BRIEF IFR IS POSSIBLE IN ANY SNOW SHOWERS...THOUGH GENERALLY VFR/MVFR CONDITIONS WILL PREVAIL. OUTLOOK 06Z THURSDAY THROUGH SUNDAY... DRIER AIR AND LESS NW FLOW INFLUENCE WILL ALLOW FOR VFR CONDITIONS WITH NEXT CHANCE OF PRECIPITATION AND POSSIBLE MVFR CONDITIONS LATE SUN/SUN NIGHT. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...SISSON NEAR TERM...SISSON SHORT TERM...WGH LONG TERM...NEILES AVIATION...NEILES
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
928 AM EDT WED MAR 27 2013 .SYNOPSIS... STRONG HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE WEST THROUGH FRIDAY. THE HIGH WILL BE OVER THE AREA SATURDAY AND THEN MOVE OFFSHORE. A WARM FRONT WILL MOVE ACROSS FROM THE SOUTH SUNDAY AND A A COLD FRONT WILL AFFECT THE AREA MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 930 AM WEDNESDAY...CLEAR SKIES CURRENTLY ACROSS EASTERN NC. FORECAST SOUNDINGS AGAIN SHOW SOME INCREASED MOISTURE AROUND THE 800 MB LEVEL AND COULD AGAIN SEE SOME COLD-AIR STRATOCUMULUS THIS AFTERNOON AND HAVE KEPT PTCLOUDY CATEGORY FOR THE AFTERNOON. TEMPERATURES SHOULD BE SIMILAR TO YESTERDAY...PERHAPS A DEGREE OR TWO WARMER WITH MOST HIGHS IN THE 50 TO 54 DEGREE RANGE...EXCEPT 45 TO 50 OVER THE NORTHERN OUTER BANKS. EVEN THOUGH THE RAP AND 4 KM WRF SHOW A FEW LIGHT SHOWERS OR SPRINKLES...SUB-CLOUD LAYER WILL LIKELY PRECLUDE ANY PRECIP REACHING THE GROUND AND WILL LEAVE POPS OUT FOR THE REMAINDER OF THE DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... AS OF 330 AM WEDNESDAY...LINGERING SCU EXPECTED TO DIMINISH WITH LOSS OF HEATING DURING EVENING SIMILAR TO PAST FEW NIGHTS. MAIN FCST ISSUE WILL BE MIN TEMPS INLAND AS GROWING SEASON STARTS TODAY FOR AREAS INLAND FROM COAST. MOS GDNC INDICATES LOWS 30-32 FOR KISO-KDPL AND KOAJ...BUT HAS BEEN TOO COOL PAST FEW NIGHTS AS LIGHT W-NW WINDS HAVE PREVENTED DECOUPLING AND KEPT TEMPS ABOVE FREEZING FOR MOST PART. SEEING A SIMILAR SET-UP FOR TONIGHT WITH CONTINUED CAA EXPECTED TO KEEP WINDS 4-6 MPH OVERNIGHT...THUS KEPT MIN TEMPS JUST ABOVE 32 AGAIN. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 310 AM WED...BOTH 26/12Z ECMWF AND 00Z GFS IN CLOSE AGREEMENT THROUGH MUCH OF THE EXTENDED PERIOD. USED A CONSENSUS BLEND. NOT MUCH CHANGE TO THE PREVIOUS EXTENDED PACKAGE...EXCEPT THAT EARLY NEXT WEEK IS LOOKING MORE UNSETTLED THAN PREVIOUSLY. THE SURFACE RIDGE TO THE NORTHWEST THURSDAY WILL PASS THROUGH THE CAROLINAS AND OFF THE SOUTHEAST COAST SUNDAY. THE UNSEASONABLY COOL NORTHWEST FLOW OF PAST SEVERAL DAYS WILL BACK TO SOUTHERLY BY SUNDAY ALLOWING TEMPS TO CLIMB CLOSER TO NORMAL. MODELS ARE A BIT FASTER IN BRINGING IN SHOWERS THIS WEEKEND. I BROUGHT IN A SLIGHT CHANCE IN THE SOUTHWEST COUNTIES FOR SATURDAY NIGHT AND CHANCE ON SUNDAY AS A WARM FRONT LIFTS INTO THE AREA. INSTABILITY FOR THUNDER WILL REMAIN TO THE SOUTH AND DID NOT INCLUDE A MENTION. CHANCE POPS CONTINUE INTO SUNDAY NIGHT AS THE WARM FRONT LIFTS THROUGH. TAPERED POPS BACK TO SLIGHT CHANCE MONDAY AS THE TRAILING COLD FRONT PASSES THROUGH IN THE MORNING. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH 12Z THURSDAY/... AS OF 700 AM WEDNESDAY...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE TAF PERIOD. MOSTLY CLEAR SKIES WILL PREVAIL THROUGH MORNING...THEN SCT-BKN CU/SCU EXPECTED DURING AFTN WITH CONTINUED SHRT WV ACTIVITY IN NW FLOW ALOFT. NW WINDS GUSTING TO AROUND 20 KT DURING PEAK HEATING. CLEARING SKIES AND DIMINISHING WINDS AGAIN THIS EVENING AND CONTINUING OVERNIGHT. LONG TERM /THU THRU SUN/ AS OF 310 AM WED...GOOD FLYING WEATHER FOR THE MOST PART BEFORE A CHANCE OF SHOWERS ARRIVES ON SUNDAY WITH THE APPROACH OF A WARM FRONT. HOWEVER...NO THUNDER FORECAST SUNDAY AS INSTABILITY WILL REMAIN WELL TO THE SOUTH. LIGHT NORTHWEST WIND THURSDAY INTO SATURDAY WILL BACK TO SOUTH ON SUNDAY. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 930 AM WEDNESDAY...WINDS HOVERING AROUND 20 KNOTS OVER THE CENTRAL WATERS WITH THE BUOY 13 MILES EAST OF OREGON INLET SHOWING 6 FEET. SMALL CRAFT WILL CONTINUE INTO EARLY AFTERNOON NORTH OF OCRACOKE. WINDS INCREASE TO AROUND 20 KT AGAIN TONIGHT WITH ANOTHER CAA SURGE. NO MAJOR CHANGES AT THIS TIME. LONG TERM /THU THRU SUN/ AS OF 310 AM WED...MODELS IN CLOSE AGREEMENT AND USED BLEND OF THE 26/12Z ECMWF AND 00Z GFS. LARGE CIRCULATION AROUND DEEP IN THE CANADIAN MARITIMES WILL FINALLY LOSE ITS GRIP ON THE AREA AS HIGH PRESSURE APPROACHES FROM THE NORTHWEST. THE HIGH WILL MOVE ACROSS THE MARINE AREA SATURDAY. ON SUNDAY THE HIGH MOVES OFF THE SOUTHEAST COAST AS A WARM FRONT LIFTS IN FROM THE SOUTH. NORTHWEST WINDS THURSDAY WILL GRADUALLY DIMINISH AND BACK TO WEST ON SATURDAY THEN SOUTHERLY ON SUNDAY. SEAS WILL SUBSIDE AS WELL. HOWEVER...SMALL CRAFT SEAS FORECAST TO RETURN ON SUNDAY IN RETURN SOUTHERLY FLOW WITH WARM FRONT LIFTING NORTH. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ150- 152-154. && $$ SYNOPSIS...JBM NEAR TERM...CTC SHORT TERM...JBM LONG TERM...HSA AVIATION...JBM/HSA MARINE...JBM/CTC/HSA
AREA FORECAST DISCUSSION
NWS TULSA OK
910 PM CDT THU MAR 28 2013 .UPDATE... FORECAST WAS UPDATED TO REDUCE POPS THIS EVENING BASED ON LATEST DATA. SEE DISCUSSION BELOW. && .DISCUSSION... THE LATEST DATA FROM THE HRRR AND NEW 00Z NAM SUGGEST THAT THE ACTIVITY WILL BE SLOWER TO GET GOING TONIGHT...AND THUS POPS WERE REDUCED THRU 06Z. POPS AFT 06Z LOOK GOOD...AND ARE A GOOD COMPROMISE BETWEEN THE HRRR AND NAM SOLUTIONS. ISENTROPIC CHARTS EXPLAIN WHY THE ACTIVITY WILL BE SLOWER TO GET GOING...WITH LITTLE IN THE WAY OF ASCENT FORECAST THRU 06Z. BY 06Z AND AFTER...THE 295K SHOWS SOME LIFT AND GOOD MOISTURE TRANSPORT AIMED AT THE OZARK REGION. THERE IS STILL A LIMITED RISK OF AN ISOLATED SEVERE HAIL STORM WITH POTENTIAL FOR UP TO HALF DOLLAR SIZE GIVEN SUFFICIENT SHEAR AND INCREASING ELEVATED INSTABILITY ACROSS EASTERN OKLAHOMA AFT MIDNIGHT. LACY && .PREV DISCUSSION... /ISSUED 630 PM CDT THU MAR 28 2013/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. CONDITIONS WILL DETERIORATE TONIGHT WITH MVFR CONDITIONS DEVELOPING AFTER MIDNIGHT AND CONTINUING THROUGH FRIDAY MORNING. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO AFFECT AREA TAFS LATE TONIGHT INTO FRIDAY MORNING WITH SOME REDEVELOPED EXPECTED LATE FRIDAY AFTERNOON PRIOR TO THE EXPIRATION OF THE CURRENT TAF PERIOD. PREV DISCUSSION... /ISSUED 346 PM CDT THU MAR 28 2013/ DISCUSSION... A NEARLY STATIONARY FRONTAL BOUNDARY WAS POSITIONED FROM THE OKLAHOMA PANHANDLE TO SOUTHEAST KANSAS THIS AFTERNOON. SOUTH OF THE BOUNDARY...TEMPERATURES ARE RUNNING ABOUT 5 TO 10 DEGREES WARMER THAN THIS TIME YESTERDAY WITH HIGH CLOUDS AND SOUTHERLY WINDS BEING COMMON. LOW LEVEL MOISTURE HAS ALSO INCREASED FROM SOUTH TO NORTH ACROSS THE REGION THIS AFTERNOON...LIMITING FIRE WEATHER DANGERS FOR EASTERN OKLAHOMA AND NORTHWEST ARKANSAS. THE FRONTAL BOUNDARY JUST NORTH OF THE CWA WILL BE THE FOCUS FOR CHANCES OF SHOWERS AND THUNDERSTORMS OVER THE NEXT SEVERAL DAYS AS MID LEVEL WAVES PROGRESS THROUGH THE PLAINS WITHIN NORTHWESTERLY UPPER LEVEL FLOW. THE FIRST WAVE IS EXPECTED TO MOVE THROUGH TONIGHT AND FRIDAY...WITH A SECOND WAVE FRIDAY NIGHT AND SATURDAY. CHANCES FOR SHOWERS AND THUNDERSTORMS BECOME POSSIBLE THIS EVENING ACROSS THE REGION WITH GREATER CHANCES LATE TONIGHT AND FRIDAY ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. CHANCES THEN CONTINUE TO SPREAD SOUTHWARD FRIDAY EVENING AND SATURDAY WITH THE NEXT WAVE. WARM SURFACE TEMPS...STEEP LAPSE RATES AND COLD TEMPERATURES ALOFT DURING THIS TIME FRAME WILL ALLOW FOR INSTABILITY TO DEVELOP OVER THE REGION WHICH COULD ALLOW FOR SOME THUNDERSTORMS TO BECOME STRONG TO SEVERE WITH LARGE HAIL BEING THE MAIN THREAT. THE FRONTAL BOUNDARY IS PROGGED TO PUSH INTO EASTERN OKLAHOMA AND NORTHWEST ARKANSAS SATURDAY NIGHT AS A MORE DEFINED UPPER LEVEL WAVE DROPS SOUTHEAST OUT OF CANADA. THIS WILL CONTINUE CHANCES FOR SHOWERS AND THUNDERSTORMS INTO SUNDAY. LATEST MODEL SOLUTIONS ARE INDICATING THAT THE FRONTAL BOUNDARY COULD HANG UP NEAR THE RED RIVER VALLEY...WHICH WOULD CONTINUE PRECIP CHANCES ACROSS THE SOUTH DURING THE DAY SUNDAY. TEMPERATURES DURING THE DAY SUNDAY LOOK TO REMAIN WARM WITH HIGHS IN THE MID 60S TO LOW 70S POSSIBLE. THE WARM TEMPERATURES WILL BE QUICK TO MOVE OUT SUNDAY NIGHT AND MONDAY AS ANOTHER MORE STRONGER COLD FRONT PUSHES THROUGH THE REGION. CHANCES OF SHOWERS AND THUNDERSTORMS WILL AGAIN SPREAD OVER THE REGION DURING THE DAY MONDAY WITH THE MOVEMENT OF THE FRONT. BEHIND THE FRONT...MUCH COLDER AND DRIER AIR IS EXPECTED TO FILTER IN WITH TEMPERATURES DROPPING DURING THE DAY BEHIND THE FRONT. LOWS TUESDAY MORNING COULD POTENTIALLY REACH CLOSE TO FREEZING NEAR THE KANSAS BORDER. THIS FRONT LOOKS TO PUSH THROUGH THE REGION AND KEEP AN UPPER LEVEL WAVE MOVING OUT OF THE DESERT SOUTHWEST SOUTH OF THE REGION. THIS SHOULD KEEP PRECIP SOUTH OF THE REGION FOR THE MIDDLE PART OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... TUL 54 69 53 71 / 50 60 70 40 FSM 53 68 54 69 / 50 60 70 60 MLC 55 69 55 71 / 30 50 70 50 BVO 52 67 51 70 / 60 60 60 30 FYV 50 65 49 66 / 60 60 70 50 BYV 49 64 49 65 / 60 60 70 50 MKO 54 68 54 69 / 50 60 70 50 MIO 50 66 51 69 / 60 60 70 50 F10 55 68 54 71 / 40 60 70 50 HHW 54 71 56 72 / 20 20 50 50 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ LONG TERM....30
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
531 AM EDT WED MAR 27 2013 .SYNOPSIS... HIGH PRESSURE WILL GRADUALLY BUILD INTO THE REGION FROM THE WEST THROUGH THE END OF THE WORKWEEK...ALLOWING FOR A SLOW WARMING TREND. THE HIGH WILL SHIFT EAST OF THE AREA THIS WEEKEND...AS A COLD FRONT PUSHES INTO THE OHIO VALLEY. && .NEAR TERM /THROUGH THURSDAY/... 430 AM UPDATE...THERE DOES SEEM TO HAVE BEEN A REDUCTION IN PRECIP ACTIVITY OVER THE PAST HOUR OR SO WITH WV IMAGERY NOW SHOWING BASE OF SHORTWAVE HAS PASSED THE MTNS. SOME STRATOCU WERE ABLE TO FORM OVER THE NRN NC FOOTHILLS EARLIER BUT THESE ARE ALSO BREAKING UP...PROBABLY FOR THE SAME REASON. CURRENT POPS OK. REVISED TEMPS THROUGH DAYBREAK FOLLOWING 4 AM OBS AND HOURLY LAMP TEMPS. AS OF 3 AM WED...UPPER TROUGH WILL REMAIN SOMEWHAT FIXED OVER THE NORTHEAST CONUS THROUGH WED NIGHT. THIS WILL ALLOW DEEP CYCLONIC FLOW TO CONTINUE ALOFT ACROSS OUR REGION. WEAK DISTURBANCES ARE SEEN ROUNDING THE TROUGH WITH THE MOST SIGNIFICANT ONE COMING IN WED AFTN AND PUSHING OUT BY AROUND MIDNIGHT WED NIGHT. LLVL FLOW WILL REMAIN STEADILY NW IN THE MTNS THROUGH THU. HOWEVER HEIGHT RISES OVER THE CENTRAL CONUS WILL ALLOW SFC HIGH TO BUILD IN WHICH WILL RELAX THE PRESSURE GRADIENT. THEREFORE THE UPSLOPING WILL DIMINISH. LLVL MOISTURE FIELDS SHOW DRYING EXCEPT FOR BRIEF UPTICKS IN RH ASSOCIATED WITH THE LIFT COMING FROM THE UPPER DISTURBANCES. WITH THE FORCING BECOMING WEAKER IN GENERAL THERE SHOULD BE AN OVERALL DOWNWARD TREND IN PRECIP COVERAGE ALONG THE TENN/NC BORDER BUT THE TREND SHOULD AT LEAST BE TO REMAIN STEADY TONIGHT WITH THE MOST SIGNIFICANT WAVE. BY EARLY DAYTIME THU ANY REMAINING PRECIP SHOULD BE CONFINED TO THE NRN MTNS. ADDITIONAL TOTALS FROM THIS MORNING WILL LIKELY BE AN INCH OR LESS...WITH DETERMINISTIC MODELS PRODUCING ONLY A COUPLE HUNDREDTHS OF TOTAL QPF THROUGH THE END OF THE PERIOD...AND SREF ACCUM PROBS SHOWING LOW CHANCES OF ANYTHING MEASURABLE. THICKNESSES DON/T MAKE A HUGE JUMP FROM WED TO THU...BUT DO MANAGE TO RISE A BIT AS THE UPPER RIDGE NEARS...AND GENERALLY LIGHTER WINDS SHOULD ALLOW BETTER WARMING...GENERALLY INTO THE MID 50S. THE SAVANNAH RIVER VALLEY COULD SEE HIGHS AROUND 60 ONCE AGAIN. TONIGHT/S LOWS REMAIN QUITE CHILLY WITH GUIDANCE SUGGESTIVE OF ANOTHER FREEZE HEADLINE. NO REASON TO BELIEVE IT WILL BE SIGNIFICANTLY WARMER TONIGHT THAN THIS MORNING...WITH UPPER RH LACKING /FOR CIRRUS WITH UPPER DISTURBANCES/ AND WINDS BEING CALM OVER MOST OF THE PIEDMONT. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 230 AM EDT ON WEDNESDAY...EXPECT QUIET CONDITIONS WITH MODERATING TEMPERATURES THROUGH THE SHORT TERM PERIOD. AN UPPER TROUGH AXIS WILL MOVE OFFSHORE THU NIGHT LEAVING OUR FORECAST AREA UNDER NORTHWEST FLOW ALOFT. THE UPPER FLOW PATTERN IS FORECAST TO REMAIN OUT OF THE NORTHWEST THROUGH FRIDAY ALLOWING CANADIAN SURFACE HIGH PRESSURE TO BUILD INTO THE REGION FROM THE WEST THROUGH THE PERIOD. CONTINUED NW COLD ADVECTION FLOW ALONG WITH GOOD RADIATIONAL COOLING WILL SUPPORT FREEZING MORNING LOW TEMPS ON FRI ACROSS MUCH OF THE REGION. HOWEVER...AFTERNOON TEMPS WILL QUICKLY WARM UP INTO THE U50/L60 EAST OF THE MOUNTAINS AS THE HIGH SETTLES OVER THE REGION AND LIGHT LLVL SWLY FLOW DEVELOPS OVER THE AREA. FOR FRI NIGHT...MODELS AGREE THAT THE CENTER OF HIGH WILL SHIFT EAST OF THE AREA AND A SERIES OF UPPER DISTURBANCES WILL RIPPLE THROUGH THE AREA IN NW FLOW ALOFT. WITH INCREASING MOIST LLVL SW FLOW AND SOME DEGREE OF UPPER FORCING...LIGHT UPSLOPE PRECIP SHOULD DEVELOP MAINLY ACROSS THE WESTERN ESCARPMENT OF THE BLUE RIDGE MOUNTAINS. THEREFORE...POPS RAMP UP INTO THE SLIGHT CHANCE RANGE OVER THE WESTERN ZONES OF THE MOUNTAINS LATE FRI NIGHT. PRECIP SHOULD BE A MIX OF RAIN AND SNOW PER MODEL SOUNDING. FRI OVERNIGHT LOW TEMPS WILL REMAIN ABOVE FREEZING LEVEL ACROSS THE PIEDMONT AND PORTIONS OF THE WESTERN MOUNTAINS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 AM EDT WEDNESDAY...MODELS AGREE THAT NW FLOW WILL CONTINUE ACROSS THE REGION THROUGH THE EXTENDED PART OF THE FORECAST. AN UPPER SHORTWAVE TROUGH WILL SWING ACROSS THE UPPER MISSISSIPPI RIVER VALLEY SATURDAY...ESTABLISHING A SOUTHWESTERLY LLVL FLOW AND BRINGING MORE MOISTURE INTO THE REGION. LIGHT PRECIP SHOULD BEGIN TO SPREAD OVER THE AREA SAT AND PRECIP BECOMES HEAVIER BY LATE SUN AS THE TROUGH AXIS ASSOCIATED WITH SURFACE COLD FRONT PUSHES THROUGH THE FORECAST AREA. POPS GENERALLY REMAIN IN THE SLIGHT CHANCE RANGE SAT AND RAMP UP INTO THE SOLID CHANCE RANGE SUN. THERE IS BROAD MODEL AGREEMENT THAT A STRONG UPPER LOW PRESSURE TROUGH WILL SWING ACROSS THE GREAT LAKES REGION EARLY NEXT WEEK...PUSHING AN ASSOCIATED COLD FRONT THROUGH THE REGION EARLY TUE. THE NEW 00Z GFS/ECMWF SUGGEST THE FRONT WILL WEAKEN AS IT MOVE SE TOWARD THE REGION. THEREFORE...I KEPT POPS IN THE SLIGHT CHANCE RANGE THROUGH THE PERIOD. TEMPERATURES WILL MODERATE OVER THE REGION THIS WEEKEND AND INTO EARLY NEXT WEEK. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... 09Z UPDATE...AT KCLT...ONLY CHANGE NEEDED IS TO BACK WINDS SLIGHTLY FOR INITIAL PERIOD FOR APPROACHING SHORTWAVE TROUGH. VFR STRATOCU DEVELOPED EARLIER TONIGHT OVER KHKY AND AREAS TO ITS NW AS THAT SHORTWAVE TROUGH PUSHED OVERHEAD. AS THE SHORTWAVE DEPARTS THE REGION THESE SHOULD BEGIN TO BREAK UP AND THEY ARE NOT EXPECTED TO AFFECT ANY OTHER TAF SITE. LIKEWISE...SOME BREAKS OCCURRING IN THE SW NC MTNS AS LLVL SUBSIDENCE INCREASES AS SFC RIDGE APPROACHES FROM WEST. CIGS REMAIN AT KAVL ATTM WITH A LOWERING TREND...NOW HOVERING JUST ABOVE VFR THRESHOLD. RAP AND LAMP BOTH SHOW A BRIEF DROP TO MVFR THERE BY 10-11Z. SOME MTN OBS SITES HAVE LIFTED WHILE OTHERS HAVE LOWERED OVER PAST COUPLE HRS...BUT WITH WAVE HAVING PASSED WILL FORGO A TEMPO FOR NOW. AT KCLT AND ELSEWHERE...VFR THROUGH THE PERIOD EXCEPT NEAR THE TENN BORDER WHERE UPSLOPE -SHSN AND CLOUDS WILL CONTINUE...ALBEIT BEGINNING TO DIMINISH FOR THE MOST PART. SFC HIGH PRESSURE WILL BUILD IN FROM THE WEST OVERNIGHT INTO WEDNESDAY MAINTAINING NORTHWEST FLOW IN THE MTNS. ENOUGH MOISTURE REMAINS TO WARRANT SOME DEGREE OF MVFR CLOUDINESS WITH OCCASIONAL MVFR VSBY IN -SHSN THOUGH THIS WILL NOT AFFECT TAF SITES. VFR CIGS AT KAVL INTO WED AFTN. WINDS SHOULD BACK TO A MORE WESTERLY DIRECTION DURING THE DAY AS THE SFC HIGH GROWS OVER THE GULF STATES...BUT RETURN TO LIGHT NW BY EVENING. THE ONLY CLOUDS SEEN OUTSIDE THE MTNS/FOOTHILLS WILL BE A FEW CIRRUS ASSOCIATED WITH FAST CYCLONIC UPPER FLOW. OUTLOOK...MVFR CIGS AND -SHSN WILL LAST INTO THU MORNING ALONG THE NC/TN BORDER...BUT NO RESTRICTIONS ARE EXPECTED EAST OF THE MTNS THROUGH THAT PERIOD. DRY HIGH PRESSURE WILL REMAIN OVER THE REGION IN THE LATE WEEK WITH VFR EXPECTED THRU FRIDAY. CONFIDENCE TABLE... 09-15Z 15-21Z 21-03Z 03-09Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .FIRE WEATHER... AS TEMPERATURES INCREASE DURING MID-WEEK...MUCH DRIER CONDITIONS ARE ANTICIPATED FOR WEDNESDAY AND THURSDAY. MINIMUM RH VALUES WILL FALL TO 20-30 PERCENT OVER MUCH OF FOOTHILLS AND PIEDMONT BOTH DAYS. WINDS SHOULDN/T BE TOO MUCH OF AN ISSUE OUTSIDE THE MTNS...BUT AN OCCASIONAL GUST OF AROUND 15 MPH WILL BE POSSIBLE BOTH DAYS. FINE FUEL MOISTURE LEVELS SHOULD CONTINUE TO DRY QUICKLY OVER THE NEXT COUPLE OF DAYS. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR GAZ018-026-028- 029. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 10 AM EDT THURSDAY FOR GAZ028-029. NC...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR NCZ035>037-056- 057-068>072-082-502-504-506-508-510. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 10 AM EDT THURSDAY FOR NCZ035>037-056-057-068>072-082-502-504-506-508-510. WINTER WEATHER ADVISORY UNTIL NOON EDT TODAY FOR NCZ033- 048>053-058-059-062-063. SC...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR SCZ004>014-019. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 10 AM EDT THURSDAY FOR SCZ004>014-019. && $$ SYNOPSIS...JOH NEAR TERM...WIMBERLEY SHORT TERM...JOH LONG TERM...JOH AVIATION...WIMBERLEY FIRE WEATHER...JOH
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
442 AM EDT WED MAR 27 2013 .SYNOPSIS... HIGH PRESSURE WILL GRADUALLY BUILD INTO THE REGION FROM THE WEST THROUGH THE END OF THE WORKWEEK...ALLOWING FOR A SLOW WARMING TREND. THE HIGH WILL SHIFT EAST OF THE AREA THIS WEEKEND...AS A COLD FRONT PUSHES INTO THE OHIO VALLEY. && .NEAR TERM /THROUGH THURSDAY/... 430 AM UPDATE...THERE DOES SEEM TO HAVE BEEN A REDUCTION IN PRECIP ACTIVITY OVER THE PAST HOUR OR SO WITH WV IMAGERY NOW SHOWING BASE OF SHORTWAVE HAS PASSED THE MTNS. SOME STRATOCU WERE ABLE TO FORM OVER THE NRN NC FOOTHILLS EARLIER BUT THESE ARE ALSO BREAKING UP...PROBABLY FOR THE SAME REASON. CURRENT POPS OK. REVISED TEMPS THROUGH DAYBREAK FOLLOWING 4 AM OBS AND HOURLY LAMP TEMPS. AS OF 3 AM WED...UPPER TROUGH WILL REMAIN SOMEWHAT FIXED OVER THE NORTHEAST CONUS THROUGH WED NIGHT. THIS WILL ALLOW DEEP CYCLONIC FLOW TO CONTINUE ALOFT ACROSS OUR REGION. WEAK DISTURBANCES ARE SEEN ROUNDING THE TROUGH WITH THE MOST SIGNIFICANT ONE COMING IN WED AFTN AND PUSHING OUT BY AROUND MIDNIGHT WED NIGHT. LLVL FLOW WILL REMAIN STEADILY NW IN THE MTNS THROUGH THU. HOWEVER HEIGHT RISES OVER THE CENTRAL CONUS WILL ALLOW SFC HIGH TO BUILD IN WHICH WILL RELAX THE PRESSURE GRADIENT. THEREFORE THE UPSLOPING WILL DIMINISH. LLVL MOISTURE FIELDS SHOW DRYING EXCEPT FOR BRIEF UPTICKS IN RH ASSOCIATED WITH THE LIFT COMING FROM THE UPPER DISTURBANCES. WITH THE FORCING BECOMING WEAKER IN GENERAL THERE SHOULD BE AN OVERALL DOWNWARD TREND IN PRECIP COVERAGE ALONG THE TENN/NC BORDER BUT THE TREND SHOULD AT LEAST BE TO REMAIN STEADY TONIGHT WITH THE MOST SIGNIFICANT WAVE. BY EARLY DAYTIME THU ANY REMAINING PRECIP SHOULD BE CONFINED TO THE NRN MTNS. ADDITIONAL TOTALS FROM THIS MORNING WILL LIKELY BE AN INCH OR LESS...WITH DETERMINISTIC MODELS PRODUCING ONLY A COUPLE HUNDREDTHS OF TOTAL QPF THROUGH THE END OF THE PERIOD...AND SREF ACCUM PROBS SHOWING LOW CHANCES OF ANYTHING MEASURABLE. THICKNESSES DON/T MAKE A HUGE JUMP FROM WED TO THU...BUT DO MANAGE TO RISE A BIT AS THE UPPER RIDGE NEARS...AND GENERALLY LIGHTER WINDS SHOULD ALLOW BETTER WARMING...GENERALLY INTO THE MID 50S. THE SAVANNAH RIVER VALLEY COULD SEE HIGHS AROUND 60 ONCE AGAIN. TONIGHT/S LOWS REMAIN QUITE CHILLY WITH GUIDANCE SUGGESTIVE OF ANOTHER FREEZE HEADLINE. NO REASON TO BELIEVE IT WILL BE SIGNIFICANTLY WARMER TONIGHT THAN THIS MORNING...WITH UPPER RH LACKING /FOR CIRRUS WITH UPPER DISTURBANCES/ AND WINDS BEING CALM OVER MOST OF THE PIEDMONT. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 230 AM EDT ON WEDNESDAY...EXPECT QUIET CONDITIONS WITH MODERATING TEMPERATURES THROUGH THE SHORT TERM PERIOD. AN UPPER TROUGH AXIS WILL MOVE OFFSHORE THU NIGHT LEAVING OUR FORECAST AREA UNDER NORTHWEST FLOW ALOFT. THE UPPER FLOW PATTERN IS FORECAST TO REMAIN OUT OF THE NORTHWEST THROUGH FRIDAY ALLOWING CANADIAN SURFACE HIGH PRESSURE TO BUILD INTO THE REGION FROM THE WEST THROUGH THE PERIOD. CONTINUED NW COLD ADVECTION FLOW ALONG WITH GOOD RADIATIONAL COOLING WILL SUPPORT FREEZING MORNING LOW TEMPS ON FRI ACROSS MUCH OF THE REGION. HOWEVER...AFTERNOON TEMPS WILL QUICKLY WARM INTO THE U50/L60 EAST OF THE MOUNTAINS AS THE HIGH SETTLES OVER THE REGION AND LLVL SWLY FLOW DEVELOPS OVER THE AREA. FOR FRI NIGHT...MODELS AGREE THAT THE CENTER OF HIGH WILL SHIFT EAST OF THE AREA AND A SERIES OF UPPER DISTURBANCES WILL RIPPLE THROUGH THE AREA IN NW FLOW ALOFT. WITH INCREASING MOIST LLVL SW FLOW AND SOME DEGREE OF UPPER FORCING...LIGHT UPSLOPE PRECIP SHOULD DEVELOP MAINLY ACROSS THE WESTERN ESCARPMENT OF THE BLUE RIDGE. THEREFORE...POPS RAMP UP INTO THE SLIGHT CHANCE RANGE OVER THE WESTERN ZONES OF THE MOUNTAINS LATE FRI NIGHT. PRECIP SHOULD BE A MIX OF RAIN AND SNOW PER MODEL SOUNDING. FRI NIGHT TEMPS WILL REMAIN ABOVE FREEZING LEVEL ACROSS THE PIEDMONT AND PORTIONS OF THE WESTERN MOUNTAINS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 200 PM EDT TUESDAY...NW FLOW WILL CONTINUE ACROSS THE REGION THROUGH THE EXTENDED PART OF THE FORECAST. ENERGY WILL DIG ACROSS THE MISSISSIPPI RIVER VALLEY LATE FRIDAY AND SATURDAY... ESTABLISHING A SOUTHWESTERLY LOW LEVEL FLOW AND BRINGING MORE MOISTURE INTO THE REGION. INITIALLY MOISTURE MAY HAVE A HARD TIME MAKING IT EAST OF THE MTNS...BUT BY THE TIME THE DIGGING SHORT WAVE STARTS TO KICK EAST ON SUNDAY WE SHOULD SEE PCPN DEVELOP ACROSS THE REGION. RIGHT NOW IT LOOKS MAINLY LIKE A RAIN EVENT...THOUGH SOME MIX IS POSSIBLE IN THE MTNS IF PCPN WERE TO BEGIN SATURDAY NIGHT. THERE IS BROAD MODEL AGREEMENT THAT THE POLAR VORTEX WILL REASSERT ITSELF OVER THE NORTHERN GREAT LAKES STATES EARLY NEXT WEEK. HOWEVER...IT/S UNCERTAIN HOW DEEP THE TROUGH WILL BE AND HOW FAR WEST IT WILL DIG. THE NEW GFS IS FAR ENOUGH WEST THAT PCPN DEVELOPS OVER THE TN VALLEY AND WRN CAROLINAS AND NE GA LATE MONDAY OR TUE. THE OLD ECMWF IS FAR ENOUGH EAST THAT HIGH PRESSURE AND DRY CONDITIONS PREVAIL. FOR NOW I JUST HAVE SLIGHT CHANCE POPS MONDAY AND DRY TUESDAY...BUT IT/S NOT A HIGH CONFIDENCE FORECAST. TEMPERATURES WILL MODERATE OVER THE REGION THIS WEEKEND AND INTO EARLY NEXT WEEK. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... 09Z UPDATE...AT KCLT...ONLY CHANGE NEEDED IS TO BACK WINDS SLIGHTLY FOR INITIAL PERIOD FOR APPROACHING SHORTWAVE TROUGH. VFR STRATOCU DEVELOPED EARLIER TONIGHT OVER KHKY AND AREAS TO ITS NW AS THAT SHORTWAVE TROUGH PUSHED OVERHEAD. AS THE SHORTWAVE DEPARTS THE REGION THESE SHOULD BEGIN TO BREAK UP AND THEY ARE NOT EXPECTED TO AFFECT ANY OTHER TAF SITE. LIKEWISE...SOME BREAKS OCCURRING IN THE SW NC MTNS AS LLVL SUBSIDENCE INCREASES AS SFC RIDGE APPROACHES FROM WEST. CIGS REMAIN AT KAVL ATTM WITH A LOWERING TREND...NOW HOVERING JUST ABOVE VFR THRESHOLD. RAP AND LAMP BOTH SHOW A BRIEF DROP TO MVFR THERE BY 10-11Z. SOME MTN OBS SITES HAVE LIFTED WHILE OTHERS HAVE LOWERED OVER PAST COUPLE HRS...BUT WITH WAVE HAVING PASSED WILL FORGO A TEMPO FOR NOW. AT KCLT AND ELSEWHERE...VFR THROUGH THE PERIOD EXCEPT NEAR THE TENN BORDER WHERE UPSLOPE -SHSN AND CLOUDS WILL CONTINUE...ALBEIT BEGINNING TO DIMINISH FOR THE MOST PART. SFC HIGH PRESSURE WILL BUILD IN FROM THE WEST OVERNIGHT INTO WEDNESDAY MAINTAINING NORTHWEST FLOW IN THE MTNS. ENOUGH MOISTURE REMAINS TO WARRANT SOME DEGREE OF MVFR CLOUDINESS WITH OCCASIONAL MVFR VSBY IN -SHSN THOUGH THIS WILL NOT AFFECT TAF SITES. VFR CIGS AT KAVL INTO WED AFTN. WINDS SHOULD BACK TO A MORE WESTERLY DIRECTION DURING THE DAY AS THE SFC HIGH GROWS OVER THE GULF STATES...BUT RETURN TO LIGHT NW BY EVENING. THE ONLY CLOUDS SEEN OUTSIDE THE MTNS/FOOTHILLS WILL BE A FEW CIRRUS ASSOCIATED WITH FAST CYCLONIC UPPER FLOW. OUTLOOK...MVFR CIGS AND -SHSN WILL LAST INTO THU MORNING ALONG THE NC/TN BORDER...BUT NO RESTRICTIONS ARE EXPECTED EAST OF THE MTNS THROUGH THAT PERIOD. DRY HIGH PRESSURE WILL REMAIN OVER THE REGION IN THE LATE WEEK WITH VFR EXPECTED THRU FRIDAY. CONFIDENCE TABLE... 08-14Z 14-20Z 20-02Z 02-08Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR GAZ018-026-028- 029. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 10 AM EDT THURSDAY FOR GAZ028-029. NC...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR NCZ035>037-056- 057-068>072-082-502-504-506-508-510. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 10 AM EDT THURSDAY FOR NCZ035>037-056-057-068>072-082-502-504-506-508-510. WINTER WEATHER ADVISORY UNTIL NOON EDT TODAY FOR NCZ033- 048>053-058-059-062-063. SC...FREEZE WARNING UNTIL 10 AM EDT THIS MORNING FOR SCZ004>014-019. FREEZE WARNING FROM MIDNIGHT TONIGHT TO 10 AM EDT THURSDAY FOR SCZ004>014-019. && $$ SYNOPSIS...JOH NEAR TERM...WIMBERLEY SHORT TERM...JOH LONG TERM...JOH/MCAVOY AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
226 PM MDT WED MAR 27 2013 .SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT ISSUED AT 221 PM MDT WED MAR 27 2013 20Z UPPER LEVEL ANALYSIS SHOWS A RIDGE OVER THE WESTERN CONUS MOVING INTO THE NORTHERN PLAINS. SKIES ACROSS THE AREA ARE MOSTLY SUNNY. WINDS ARE LIGHT AND VARIABLE...AND TEMPS ARE CLIMBING INTO THE 40S AND LOWER 50S. LIGHT WINDS AND PARTLY CLOUDY SKIES ARE EXPECTED TONIGHT...WITH LOWS IN THE 20S. THE NAM IS SHOWING THE POSSIBILITY FOR SOME PATCHY SHALLOW FOG ACROSS PARTS OF WESTERN SOUTH DAKOTA BY EARLY THURSDAY MORNING...BUT THE RAP AND GFS ARE DRIER. NOT CONVINCED ANYTHING WILL DEVELOP...SO WILL LEAVE IT OUT OF THE FORECAST FOR NOW. AS THE RIDGE PROGRESSES EASTWARD...TEMPS WILL WARM INTO LOWER 50S TO LOWER 60S ON THURSDAY. WINDS WILL BE LIGHT AND EASTERLY. A SMALL AMOUNT OF CAPE IS EXPECTED TO DEVELOP OVER THE BLACK HILLS IN THE LATE AFTERNOON...ALONG AN AREA OF FRONTOGENESIS AND MOISTURE CONVERGENCE. THEREFORE...THE HILLS COULD SEE SOME LIGHT RAIN SHOWERS THURSDAY AFTERNOON. THE POSSIBILITY FOR FOG LOOKS A LITTLE BETTER EARLY FRIDAY MORNING WITH HIGHER RH PREDICTED...BUT WILL LET LATER SHIFTS DECIDE ON WHETHER TO ADD IT. .LONG TERM...FRIDAY THROUGH WEDNESDAY ISSUED AT 221 PM MDT WED MAR 27 2013 RIDGE TO THE WEST WILL WEAKEN BY THE WEEKEND AS UPPER LOW SLIDES SLOWLY SOUTHEAST ACROSS SOUTH CENTRAL CANADA. CYCLONIC FLOW AROUND THE LOW WILL BRING AN UPPER LEVEL DISTURBANCE THROUGH THE AREA FRIDAY NIGHT AND SATURDAY. FRIDAY WILL BE THE MILDEST DAY OF THE WEEK...WITH HIGH TEMPERATURES IN THE MID 50S TO MID 60S. A FEW SHOWERS ARE POSSIBLE OVER THE BLACK HILLS FRIDAY AFTERNOON AS THE DISTURBANCE APPROACHES. WITH SOME WEAK INSTABILITY IN PLACE...WOULD NOT BE SURPRISED TO SEE A FEW THUNDERSTORMS LATE FRIDAY INTO FRIDAY EVENING FROM THE BLACK HILLS AREA INTO SOUTHERN SD. OTHERWISE...WILL KEEP CHANCE FOR MOSTLY RAIN SHOWERS...WITH LATE NIGHT/EARLY MORNING SNOW SHOWERS POSSIBLE OVER NORTHERN AND WESTERN PORTIONS OF THE CWA. BEYOND SATURDAY...THE FORECAST REMAINS UNCERTAIN WITH AN UPPER LOW MOVING EAST ACROSS THE SOUTHWESTERN CONUS AND A STRONGER UPPER LOW ACROSS CENTRAL CANADA BRINGING DEEP NORTHWEST FLOW ACROSS THE REGION. ADDITIONAL WEAKER DISTURBANCES IN THE NORTHWESTERLY FLOW WILL MOVE ACROSS THE REGION THROUGH SUNDAY...SO WILL KEEP SOME SLIGHT CHANCES FOR SHOWERS ACROSS THE CWA. DRIER CONDITIONS ARE EXPECTED FOR THE EARLY WORK WEEK AS A COLD CANADIAN AIRMASS PUSHES INTO THE NORTHERN PLAINS. HAVE DROPPED TEMPS FOR THIS PERIOD...BUT MAY NEED TO BE DROPPED FURTHER IF TRENDS CONTINUE TOWARD COLDER AIR. && .AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON ISSUED AT 926 AM MDT WED MAR 27 2013 VFR CONDITIONS WITH LIGHT WINDS WILL PREVAIL THROUGH TONIGHT INTO THURSDAY MORNING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...POJORLIE LONG TERM...13 AVIATION...BARBER
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1234 PM CDT WED MAR 27 2013 .UPDATE... ISSUED AT 1025 AM CDT WED MAR 27 2013 BRIGHT AND SUNNY WITH AT MOST PATCHY MID AND HIGH CLOUDS. EARLIER FORECAST WAS PRETTY GOOD BUT HAVE BUMPED UP HIGH TEMPERATURES FOR THIS AFTERNOON A LITTLE. ALSO WINDS NEED A LITTLE ADJUSTING TO MORE SOUTHEASTERLY INSTEAD OF EAST SOUTHEASTERLY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 336 AM CDT WED MAR 27 2013 WEAK SURFACE RIDGE AXIS SPRAWLS ACROSS MINNESOTA AND EASTERN IOWA EARLY THIS MORNING. HIGH CLOUDS WITH WEAK WAVE ARE PULLING AWAY... WITH MAINLY CLEAR SKIES OVERHEAD. HAVE NOT YET SEEN EARLIER EXPECTATIONS OF WIDESPREAD FOG WITH A PATCHY FREEZING DRIZZLE THREAT MATERIALIZE WITH MOIST LAYER LIKELY JUST A BIT TOO SHALLOW BASED ON RAP THERMODYNAMIC PROFILES...AND GRADIENT JUST A BIT TOO STOUT IN THE SOUTH CENTRAL...SO REMOVED FROM FORECAST EARLIER THIS MORNING. OTHERWISE...OUR LONG ADVERTISED WARMING TREND SHOULD CONTINUE TODAY...AS BUILDING HEIGHTS AND ABUNDANT SUNSHINE ATTEMPT TO OVERCOME LINGERING SNOWCOVER...GREATEST ALONG AND NORTH OF HIGHWAY 14...GREGORY COUNTY...AND THROUGH MUCH OF NORTHWEST IOWA... ESPECIALLY THE SOUTHEAST SECTIONS. MODELS SEEM TO HAVE BIAS TO GREAT COVERAGE AND IMPACT...KEEPING SURFACE LAYER A BIT TOO COOL OVERALL WITH EXCEPTION OF THE DEEPER AREAS. LIKELY TO FIND A LITTLE PATCHY MID CLOUD DRIFTING ACROSS MAINLY THE NORTHERN AREAS WITH SOME WEAK ELEVATED WARM AIR ADVECTION/FRONTOGENESIS THROUGH MIDDAY...AND WILL ALSO FIND A LITTLE FOG AROUND AND FOR A COUPLE HOURS AFTER SUNRISE WHERE FLOW IS BIT WEAKER THROUGH THE NORTH/EAST CWA...AND WHERE TERRAIN CAN HELP FOCUS. STRATOCUMULUS DEVELOPMENT DOES NOT LOOK AS FAVORED TODAY. AFTER ANOTHER DAY OF MELTING AND LIMITED MIXING...LOOKS TO MOISTEN UP THE SUB INVERSION LAYER A BIT MORE. WITH LATER NIGHT SLIGHT WEAKENING OF LOW LEVEL WINDS AND VEERING PROFILE...PROSPECT FOR A LITTLE BETTER COVERAGE OF FOG EXISTS...AND GIVEN THE PERSISTENCE OF EAST TO SOUTHEAST FLOW...MAY BE A REPEAT PERFORMANCE FOR A COUPLE MORNINGS AFTER THIS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 336 AM CDT WED MAR 27 2013 WHILE A COUPLE OF WEAKER SYSTEMS MOVE QUICKLY PAST IN NORTHWEST FLOW ALOFT ON THURSDAY AND AGAIN ON FRIDAY...THERE IS LITTLE MOISTURE ALOFT FOR SYSTEM TO WORK WITH...AND THUS AM NOT LOOKING AT ANY SIGNIFICANT PRECIPITATION THREAT THROUGH FRIDAY. TEMPERATURES CONTINUE TO WARM ALOFT...AND WILL SEE READINGS CREEP UPWARD BOTH DAY AND NIGHT THROUGH FRIDAY...ESPECIALLY FRIDAY AS FLOW BECOMES MORE SOUTHERLY AT LOW LEVELS. A LITTLE STRONGER WAVE SLATED TO SLIDE SOUTHEAST FRIDAY NIGHT AND EARLY SATURDAY. A LITTLE RICHER MOISTURE FLOW ON SOUTHERLY FLOW PRIMES THE PUMP AHEAD OF TROUGH PUSHING ACROSS NEBRASKA...AND SHOULD SEE INCREASE CHANCE LEVEL POPS AS FRIDAY NIGHT PROGRESSES...ESPECIALLY SOUTH. TEMPS ALOFT FAR TOO WARM FOR ANYTHING OTHER THAN LIQUID... AND PROGGED SURFACE TEMPS SHOULD KEEP FROM ANY FREEZING RAIN...ALTHOUGH REMAINING COLD GROUND TEMPERATURES MAY YIELD A COUPLE OF SLIPPERY SPOTS WHERE DAYTIME SOLAR POWER FAILS TO REACH. DID TOSS IN ISOLATED THUNDER TO LOWER MISSOURI VALLEY THROUGH NORTHWEST IOWA LATER FRIDAY NIGHT/SATURDAY MORNING...WITH WEAK ELEVATED INSTABILITY. BEST CHANCE OF PRECIPITATION LOOKS TO FIT SATURDAY PERIOD... AND IF MODEL TRENDS CONTINUE ON SPEEDING UP THE MID LEVEL TROUGH...MAY BE ABLE TO KNOCK BACK AFTERNOON CHANCE EVEN MORE. THIS WILL SAY A LOT ABOUT TEMPERATURE POTENTIAL...WITH CURRENT FORECAST HOLDING BACK A BIT WITH CLOUDS/PRECIP...ESPECIALLY SOUTH AND EAST. WARMUP HAS AN UNFORTUNATE END WITH VERY STRONG WAVE DIGGING ANOMALOUSLY DEEP TROUGH TOWARD THE NORTHERN GREAT LAKES SUNDAY INTO MONDAY...AND SHOVING A STRONG COLD FRONT SOUTHWARD THROUGH THE PLAINS. STILL A DECENT AMOUNT OF SPREAD SURROUNDING THE FRONTAL PASSAGE...WITH GFS/CANADIAN AS MUCH AS 6 TO 12 HOURS QUICKER. HUGE POTENTIAL DIFFERENCES RESULT FROM FRONTAL TIMING... WITH ECMWF INDICATING A WINDOW FOR MIXING TOWARD NORMAL THROUGH MIDDAY SUNDAY BEFORE TEMPS FALL BACK...BUT GFS/CANADIAN VERY LITTLE CHANCE OF THAT...AND LIKELY AROUND 10 DEGREES COOLER. SOMEWHAT MORE ECMWF INFLUENCE IN FORECAST...BUT WEIGHTED IT WITH MORE IMPACT SOUTH THAN NORTH. LIKELY THAT WILL GET A FAIRLY LARGE EXPANSE OF LOWER CLOUDINESS SWEEPING THROUGH ON SUNDAY NIGHT AND INTO MONDAY...WITH TEMPERATURES FALLING BACK TO DENDRITIC IN CLOUD LAYER...SUGGESTING FLURRIES ONCE AGAIN AT TIMES DURING THAT PERIOD...NO APRIL FOOLS. REMAINDER OF THE FORECAST INTO TUESDAY WILL CONTINUE THE VERY COLD THEME...AS SURFACE RIDGE BECOMES CENTERED OVER THE AREA BY TUESDAY MORNING. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1230 PM CDT WED MAR 27 2013 VFR EXCEPT FOR PATCHY 3-5SM AND ISOLATED 1-3SM IN FOG 28/08Z-16Z. CLOUDS ABOVE 8K FEET AGL WILL INCREASE FROM THE WEST AFTER 28/09Z. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...25 SHORT TERM...CHAPMAN LONG TERM...CHAPMAN AVIATION...25
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1025 AM CDT WED MAR 27 2013 .UPDATE... ISSUED AT 1025 AM CDT WED MAR 27 2013 BRIGHT AND SUNNY WITH AT MOST PATCHY MID AND HIGH CLOUDS. EARLIER FORECAST WAS PRETTY GOOD BUT HAVE BUMPED UP HIGH TEMPERATURES FOR THIS AFTERNOON A LITTLE. ALSO WINDS NEED A LITTLE ADJUSTING TO MORE SOUTHEASTERLY INSTEAD OF EAST SOUTHEASTERLY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 336 AM CDT WED MAR 27 2013 WEAK SURFACE RIDGE AXIS SPRAWLS ACROSS MINNESOTA AND EASTERN IOWA EARLY THIS MORNING. HIGH CLOUDS WITH WEAK WAVE ARE PULLING AWAY... WITH MAINLY CLEAR SKIES OVERHEAD. HAVE NOT YET SEEN EARLIER EXPECTATIONS OF WIDESPREAD FOG WITH A PATCHY FREEZING DRIZZLE THREAT MATERIALIZE WITH MOIST LAYER LIKELY JUST A BIT TOO SHALLOW BASED ON RAP THERMODYNAMIC PROFILES...AND GRADIENT JUST A BIT TOO STOUT IN THE SOUTH CENTRAL...SO REMOVED FROM FORECAST EARLIER THIS MORNING. OTHERWISE...OUR LONG ADVERTISED WARMING TREND SHOULD CONTINUE TODAY...AS BUILDING HEIGHTS AND ABUNDANT SUNSHINE ATTEMPT TO OVERCOME LINGERING SNOWCOVER...GREATEST ALONG AND NORTH OF HIGHWAY 14...GREGORY COUNTY...AND THROUGH MUCH OF NORTHWEST IOWA... ESPECIALLY THE SOUTHEAST SECTIONS. MODELS SEEM TO HAVE BIAS TO GREAT COVERAGE AND IMPACT...KEEPING SURFACE LAYER A BIT TOO COOL OVERALL WITH EXCEPTION OF THE DEEPER AREAS. LIKELY TO FIND A LITTLE PATCHY MID CLOUD DRIFTING ACROSS MAINLY THE NORTHERN AREAS WITH SOME WEAK ELEVATED WARM AIR ADVECTION/FRONTOGENESIS THROUGH MIDDAY...AND WILL ALSO FIND A LITTLE FOG AROUND AND FOR A COUPLE HOURS AFTER SUNRISE WHERE FLOW IS BIT WEAKER THROUGH THE NORTH/EAST CWA...AND WHERE TERRAIN CAN HELP FOCUS. STRATOCUMULUS DEVELOPMENT DOES NOT LOOK AS FAVORED TODAY. AFTER ANOTHER DAY OF MELTING AND LIMITED MIXING...LOOKS TO MOISTEN UP THE SUB INVERSION LAYER A BIT MORE. WITH LATER NIGHT SLIGHT WEAKENING OF LOW LEVEL WINDS AND VEERING PROFILE...PROSPECT FOR A LITTLE BETTER COVERAGE OF FOG EXISTS...AND GIVEN THE PERSISTENCE OF EAST TO SOUTHEAST FLOW...MAY BE A REPEAT PERFORMANCE FOR A COUPLE MORNINGS AFTER THIS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 336 AM CDT WED MAR 27 2013 WHILE A COUPLE OF WEAKER SYSTEMS MOVE QUICKLY PAST IN NORTHWEST FLOW ALOFT ON THURSDAY AND AGAIN ON FRIDAY...THERE IS LITTLE MOISTURE ALOFT FOR SYSTEM TO WORK WITH...AND THUS AM NOT LOOKING AT ANY SIGNIFICANT PRECIPITATION THREAT THROUGH FRIDAY. TEMPERATURES CONTINUE TO WARM ALOFT...AND WILL SEE READINGS CREEP UPWARD BOTH DAY AND NIGHT THROUGH FRIDAY...ESPECIALLY FRIDAY AS FLOW BECOMES MORE SOUTHERLY AT LOW LEVELS. A LITTLE STRONGER WAVE SLATED TO SLIDE SOUTHEAST FRIDAY NIGHT AND EARLY SATURDAY. A LITTLE RICHER MOISTURE FLOW ON SOUTHERLY FLOW PRIMES THE PUMP AHEAD OF TROUGH PUSHING ACROSS NEBRASKA...AND SHOULD SEE INCREASE CHANCE LEVEL POPS AS FRIDAY NIGHT PROGRESSES...ESPECIALLY SOUTH. TEMPS ALOFT FAR TOO WARM FOR ANYTHING OTHER THAN LIQUID... AND PROGGED SURFACE TEMPS SHOULD KEEP FROM ANY FREEZING RAIN...ALTHOUGH REMAINING COLD GROUND TEMPERATURES MAY YIELD A COUPLE OF SLIPPERY SPOTS WHERE DAYTIME SOLAR POWER FAILS TO REACH. DID TOSS IN ISOLATED THUNDER TO LOWER MISSOURI VALLEY THROUGH NORTHWEST IOWA LATER FRIDAY NIGHT/SATURDAY MORNING...WITH WEAK ELEVATED INSTABILITY. BEST CHANCE OF PRECIPITATION LOOKS TO FIT SATURDAY PERIOD... AND IF MODEL TRENDS CONTINUE ON SPEEDING UP THE MID LEVEL TROUGH...MAY BE ABLE TO KNOCK BACK AFTERNOON CHANCE EVEN MORE. THIS WILL SAY A LOT ABOUT TEMPERATURE POTENTIAL...WITH CURRENT FORECAST HOLDING BACK A BIT WITH CLOUDS/PRECIP...ESPECIALLY SOUTH AND EAST. WARMUP HAS AN UNFORTUNATE END WITH VERY STRONG WAVE DIGGING ANOMALOUSLY DEEP TROUGH TOWARD THE NORTHERN GREAT LAKES SUNDAY INTO MONDAY...AND SHOVING A STRONG COLD FRONT SOUTHWARD THROUGH THE PLAINS. STILL A DECENT AMOUNT OF SPREAD SURROUNDING THE FRONTAL PASSAGE...WITH GFS/CANADIAN AS MUCH AS 6 TO 12 HOURS QUICKER. HUGE POTENTIAL DIFFERENCES RESULT FROM FRONTAL TIMING... WITH ECMWF INDICATING A WINDOW FOR MIXING TOWARD NORMAL THROUGH MIDDAY SUNDAY BEFORE TEMPS FALL BACK...BUT GFS/CANADIAN VERY LITTLE CHANCE OF THAT...AND LIKELY AROUND 10 DEGREES COOLER. SOMEWHAT MORE ECMWF INFLUENCE IN FORECAST...BUT WEIGHTED IT WITH MORE IMPACT SOUTH THAN NORTH. LIKELY THAT WILL GET A FAIRLY LARGE EXPANSE OF LOWER CLOUDINESS SWEEPING THROUGH ON SUNDAY NIGHT AND INTO MONDAY...WITH TEMPERATURES FALLING BACK TO DENDRITIC IN CLOUD LAYER...SUGGESTING FLURRIES ONCE AGAIN AT TIMES DURING THAT PERIOD...NO APRIL FOOLS. REMAINDER OF THE FORECAST INTO TUESDAY WILL CONTINUE THE VERY COLD THEME...AS SURFACE RIDGE BECOMES CENTERED OVER THE AREA BY TUESDAY MORNING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 657 AM CDT WED MAR 27 2013 VFR THROUGH THE PERIOD. THERE WILL BE A SMALL THREAT FOR SOME IFR FOG AFTER ABOUT 9Z TONIGHT BUT CONFIDENCE IS NOT REAL HIGH AT THIS TIME. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...25 SHORT TERM...CHAPMAN LONG TERM...CHAPMAN AVIATION...08
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
658 AM CDT WED MAR 27 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 336 AM CDT WED MAR 27 2013 WEAK SURFACE RIDGE AXIS SPRAWLS ACROSS MINNESOTA AND EASTERN IOWA EARLY THIS MORNING. HIGH CLOUDS WITH WEAK WAVE ARE PULLING AWAY... WITH MAINLY CLEAR SKIES OVERHEAD. HAVE NOT YET SEEN EARLIER EXPECTATIONS OF WIDESPREAD FOG WITH A PATCHY FREEZING DRIZZLE THREAT MATERIALIZE WITH MOIST LAYER LIKELY JUST A BIT TOO SHALLOW BASED ON RAP THERMODYNAMIC PROFILES...AND GRADIENT JUST A BIT TOO STOUT IN THE SOUTH CENTRAL...SO REMOVED FROM FORECAST EARLIER THIS MORNING. OTHERWISE...OUR LONG ADVERTISED WARMING TREND SHOULD CONTINUE TODAY...AS BUILDING HEIGHTS AND ABUNDANT SUNSHINE ATTEMPT TO OVERCOME LINGERING SNOWCOVER...GREATEST ALONG AND NORTH OF HIGHWAY 14...GREGORY COUNTY...AND THROUGH MUCH OF NORTHWEST IOWA... ESPECIALLY THE SOUTHEAST SECTIONS. MODELS SEEM TO HAVE BIAS TO GREAT COVERAGE AND IMPACT...KEEPING SURFACE LAYER A BIT TOO COOL OVERALL WITH EXCEPTION OF THE DEEPER AREAS. LIKELY TO FIND A LITTLE PATCHY MID CLOUD DRIFTING ACROSS MAINLY THE NORTHERN AREAS WITH SOME WEAK ELEVATED WARM AIR ADVECTION/FRONTOGENESIS THROUGH MIDDAY...AND WILL ALSO FIND A LITTLE FOG AROUND AND FOR A COUPLE HOURS AFTER SUNRISE WHERE FLOW IS BIT WEAKER THROUGH THE NORTH/EAST CWA...AND WHERE TERRAIN CAN HELP FOCUS. STRATOCUMULUS DEVELOPMENT DOES NOT LOOK AS FAVORED TODAY. AFTER ANOTHER DAY OF MELTING AND LIMITED MIXING...LOOKS TO MOISTEN UP THE SUB INVERSION LAYER A BIT MORE. WITH LATER NIGHT SLIGHT WEAKENING OF LOW LEVEL WINDS AND VEERING PROFILE...PROSPECT FOR A LITTLE BETTER COVERAGE OF FOG EXISTS...AND GIVEN THE PERSISTENCE OF EAST TO SOUTHEAST FLOW...MAY BE A REPEAT PERFORMANCE FOR A COUPLE MORNINGS AFTER THIS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 336 AM CDT WED MAR 27 2013 WHILE A COUPLE OF WEAKER SYSTEMS MOVE QUICKLY PAST IN NORTHWEST FLOW ALOFT ON THURSDAY AND AGAIN ON FRIDAY...THERE IS LITTLE MOISTURE ALOFT FOR SYSTEM TO WORK WITH...AND THUS AM NOT LOOKING AT ANY SIGNIFICANT PRECIPITATION THREAT THROUGH FRIDAY. TEMPERATURES CONTINUE TO WARM ALOFT...AND WILL SEE READINGS CREEP UPWARD BOTH DAY AND NIGHT THROUGH FRIDAY...ESPECIALLY FRIDAY AS FLOW BECOMES MORE SOUTHERLY AT LOW LEVELS. A LITTLE STRONGER WAVE SLATED TO SLIDE SOUTHEAST FRIDAY NIGHT AND EARLY SATURDAY. A LITTLE RICHER MOISTURE FLOW ON SOUTHERLY FLOW PRIMES THE PUMP AHEAD OF TROUGH PUSHING ACROSS NEBRASKA...AND SHOULD SEE INCREASE CHANCE LEVEL POPS AS FRIDAY NIGHT PROGRESSES...ESPECIALLY SOUTH. TEMPS ALOFT FAR TOO WARM FOR ANYTHING OTHER THAN LIQUID... AND PROGGED SURFACE TEMPS SHOULD KEEP FROM ANY FREEZING RAIN...ALTHOUGH REMAINING COLD GROUND TEMPERATURES MAY YIELD A COUPLE OF SLIPPERY SPOTS WHERE DAYTIME SOLAR POWER FAILS TO REACH. DID TOSS IN ISOLATED THUNDER TO LOWER MISSOURI VALLEY THROUGH NORTHWEST IOWA LATER FRIDAY NIGHT/SATURDAY MORNING...WITH WEAK ELEVATED INSTABILITY. BEST CHANCE OF PRECIPITATION LOOKS TO FIT SATURDAY PERIOD... AND IF MODEL TRENDS CONTINUE ON SPEEDING UP THE MID LEVEL TROUGH...MAY BE ABLE TO KNOCK BACK AFTERNOON CHANCE EVEN MORE. THIS WILL SAY A LOT ABOUT TEMPERATURE POTENTIAL...WITH CURRENT FORECAST HOLDING BACK A BIT WITH CLOUDS/PRECIP...ESPECIALLY SOUTH AND EAST. WARMUP HAS AN UNFORTUNATE END WITH VERY STRONG WAVE DIGGING ANOMALOUSLY DEEP TROUGH TOWARD THE NORTHERN GREAT LAKES SUNDAY INTO MONDAY...AND SHOVING A STRONG COLD FRONT SOUTHWARD THROUGH THE PLAINS. STILL A DECENT AMOUNT OF SPREAD SURROUNDING THE FRONTAL PASSAGE...WITH GFS/CANADIAN AS MUCH AS 6 TO 12 HOURS QUICKER. HUGE POTENTIAL DIFFERENCES RESULT FROM FRONTAL TIMING... WITH ECMWF INDICATING A WINDOW FOR MIXING TOWARD NORMAL THROUGH MIDDAY SUNDAY BEFORE TEMPS FALL BACK...BUT GFS/CANADIAN VERY LITTLE CHANCE OF THAT...AND LIKELY AROUND 10 DEGREES COOLER. SOMEWHAT MORE ECMWF INFLUENCE IN FORECAST...BUT WEIGHTED IT WITH MORE IMPACT SOUTH THAN NORTH. LIKELY THAT WILL GET A FAIRLY LARGE EXPANSE OF LOWER CLOUDINESS SWEEPING THROUGH ON SUNDAY NIGHT AND INTO MONDAY...WITH TEMPERATURES FALLING BACK TO DENDRITIC IN CLOUD LAYER...SUGGESTING FLURRIES ONCE AGAIN AT TIMES DURING THAT PERIOD...NO APRIL FOOLS. REMAINDER OF THE FORECAST INTO TUESDAY WILL CONTINUE THE VERY COLD THEME...AS SURFACE RIDGE BECOMES CENTERED OVER THE AREA BY TUESDAY MORNING. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 657 AM CDT WED MAR 27 2013 VFR THROUGH THE PERIOD. THERE WILL BE A SMALL THREAT FOR SOME IFR FOG AFTER ABOUT 9Z TONIGHT BUT CONFIDENCE IS NOT REAL HIGH AT THIS TIME. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHAPMAN LONG TERM...CHAPMAN AVIATION...08
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
422 AM CDT WED MAR 27 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 336 AM CDT WED MAR 27 2013 WEAK SURFACE RIDGE AXIS SPRAWLS ACROSS MINNESOTA AND EASTERN IOWA EARLY THIS MORNING. HIGH CLOUDS WITH WEAK WAVE ARE PULLING AWAY... WITH MAINLY CLEAR SKIES OVERHEAD. HAVE NOT YET SEEN EARLIER EXPECTATIONS OF WIDESPREAD FOG WITH A PATCHY FREEZING DRIZZLE THREAT MATERIALIZE WITH MOIST LAYER LIKELY JUST A BIT TOO SHALLOW BASED ON RAP THERMODYNAMIC PROFILES...AND GRADIENT JUST A BIT TOO STOUT IN THE SOUTH CENTRAL...SO REMOVED FROM FORECAST EARLIER THIS MORNING. OTHERWISE...OUR LONG ADVERTISED WARMING TREND SHOULD CONTINUE TODAY...AS BUILDING HEIGHTS AND ABUNDANT SUNSHINE ATTEMPT TO OVERCOME LINGERING SNOWCOVER...GREATEST ALONG AND NORTH OF HIGHWAY 14...GREGORY COUNTY...AND THROUGH MUCH OF NORTHWEST IOWA... ESPECIALLY THE SOUTHEAST SECTIONS. MODELS SEEM TO HAVE BIAS TO GREAT COVERAGE AND IMPACT...KEEPING SURFACE LAYER A BIT TOO COOL OVERALL WITH EXCEPTION OF THE DEEPER AREAS. LIKELY TO FIND A LITTLE PATCHY MID CLOUD DRIFTING ACROSS MAINLY THE NORTHERN AREAS WITH SOME WEAK ELEVATED WARM AIR ADVECTION/FRONTOGENESIS THROUGH MIDDAY...AND WILL ALSO FIND A LITTLE FOG AROUND AND FOR A COUPLE HOURS AFTER SUNRISE WHERE FLOW IS BIT WEAKER THROUGH THE NORTH/EAST CWA...AND WHERE TERRAIN CAN HELP FOCUS. STRATOCUMULUS DEVELOPMENT DOES NOT LOOK AS FAVORED TODAY. AFTER ANOTHER DAY OF MELTING AND LIMITED MIXING...LOOKS TO MOISTEN UP THE SUB INVERSION LAYER A BIT MORE. WITH LATER NIGHT SLIGHT WEAKENING OF LOW LEVEL WINDS AND VEERING PROFILE...PROSPECT FOR A LITTLE BETTER COVERAGE OF FOG EXISTS...AND GIVEN THE PERSISTENCE OF EAST TO SOUTHEAST FLOW...MAY BE A REPEAT PERFORMANCE FOR A COUPLE MORNINGS AFTER THIS. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 336 AM CDT WED MAR 27 2013 WHILE A COUPLE OF WEAKER SYSTEMS MOVE QUICKLY PAST IN NORTHWEST FLOW ALOFT ON THURSDAY AND AGAIN ON FRIDAY...THERE IS LITTLE MOISTURE ALOFT FOR SYSTEM TO WORK WITH...AND THUS AM NOT LOOKING AT ANY SIGNIFICANT PRECIPITATION THREAT THROUGH FRIDAY. TEMPERATURES CONTINUE TO WARM ALOFT...AND WILL SEE READINGS CREEP UPWARD BOTH DAY AND NIGHT THROUGH FRIDAY...ESPECIALLY FRIDAY AS FLOW BECOMES MORE SOUTHERLY AT LOW LEVELS. A LITTLE STRONGER WAVE SLATED TO SLIDE SOUTHEAST FRIDAY NIGHT AND EARLY SATURDAY. A LITTLE RICHER MOISTURE FLOW ON SOUTHERLY FLOW PRIMES THE PUMP AHEAD OF TROUGH PUSHING ACROSS NEBRASKA...AND SHOULD SEE INCREASE CHANCE LEVEL POPS AS FRIDAY NIGHT PROGRESSES...ESPECIALLY SOUTH. TEMPS ALOFT FAR TOO WARM FOR ANYTHING OTHER THAN LIQUID... AND PROGGED SURFACE TEMPS SHOULD KEEP FROM ANY FREEZING RAIN...ALTHOUGH REMAINING COLD GROUND TEMPERATURES MAY YIELD A COUPLE OF SLIPPERY SPOTS WHERE DAYTIME SOLAR POWER FAILS TO REACH. DID TOSS IN ISOLATED THUNDER TO LOWER MISSOURI VALLEY THROUGH NORTHWEST IOWA LATER FRIDAY NIGHT/SATURDAY MORNING...WITH WEAK ELEVATED INSTABILITY. BEST CHANCE OF PRECIPITATION LOOKS TO FIT SATURDAY PERIOD... AND IF MODEL TRENDS CONTINUE ON SPEEDING UP THE MID LEVEL TROUGH...MAY BE ABLE TO KNOCK BACK AFTERNOON CHANCE EVEN MORE. THIS WILL SAY A LOT ABOUT TEMPERATURE POTENTIAL...WITH CURRENT FORECAST HOLDING BACK A BIT WITH CLOUDS/PRECIP...ESPECIALLY SOUTH AND EAST. WARMUP HAS AN UNFORTUNATE END WITH VERY STRONG WAVE DIGGING ANOMALOUSLY DEEP TROUGH TOWARD THE NORTHERN GREAT LAKES SUNDAY INTO MONDAY...AND SHOVING A STRONG COLD FRONT SOUTHWARD THROUGH THE PLAINS. STILL A DECENT AMOUNT OF SPREAD SURROUNDING THE FRONTAL PASSAGE...WITH GFS/CANADIAN AS MUCH AS 6 TO 12 HOURS QUICKER. HUGE POTENTIAL DIFFERENCES RESULT FROM FRONTAL TIMING... WITH ECMWF INDICATING A WINDOW FOR MIXING TOWARD NORMAL THROUGH MIDDAY SUNDAY BEFORE TEMPS FALL BACK...BUT GFS/CANADIAN VERY LITTLE CHANCE OF THAT...AND LIKELY AROUND 10 DEGREES COOLER. SOMEWHAT MORE ECMWF INFLUENCE IN FORECAST...BUT WEIGHTED IT WITH MORE IMPACT SOUTH THAN NORTH. LIKELY THAT WILL GET A FAIRLY LARGE EXPANSE OF LOWER CLOUDINESS SWEEPING THROUGH ON SUNDAY NIGHT AND INTO MONDAY...WITH TEMPERATURES FALLING BACK TO DENDRITIC IN CLOUD LAYER...SUGGESTING FLURRIES ONCE AGAIN AT TIMES DURING THAT PERIOD...NO APRIL FOOLS. REMAINDER OF THE FORECAST INTO TUESDAY WILL CONTINUE THE VERY COLD THEME...AS SURFACE RIDGE BECOMES CENTERED OVER THE AREA BY TUESDAY MORNING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1039 PM CDT TUE MAR 26 2013 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE FORECAST PERIOD. LIGHT EASTERLY FLOW IS EXPECTED...WITH THE POTENTIAL OF FOG DEVELOPING WEDNESDAY NIGHT. CONFIDENCE IS LOW AT THIS POINT WITH MODELS DOING A RELATIVELY POOR JOB WITH MOISTURE...SO DID NOT INCLUDE IN THE FORECAST FOR NOW. WILL BE SOMETHING WE HAVE TO WATCH FOR FUTURE UPDATES. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...CHAPMAN LONG TERM...CHAPMAN AVIATION...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
402 PM EDT WED MAR 27 2013 .SYNOPSIS... LITTLE CHANGE IS EXPECTED IN THE WEATHER PATTERN THROUGH THURSDAY. FRIDAY AND SATURDAY HIGH PRESSURE BUILDS INTO THE REGION THEN MOVES OFFSHORE. A COLD FRONT WILL APPROACH THE REGION EARLY NEXT WEEK. && .NEAR TERM /THROUGH THURSDAY/... AS OF 400 PM EDT WEDNESDAY... EXPECTING TWO SHORT WAVES TO ENHANCE UPSLOPE SHOWERS. THE FIRST WAS CROSSING THROUGH THE REGION OUT OF THE OHIO VALLEY THIS EVENING. COVERAGE ON RADAR HAD BEEN INCREASING AS THIS WAVE APPROACHED. WATER VAPOR LOOP SHOWED THE NEXT FEATURE MOVING SOUTH THROUGH THE EASTERN GREAT LAKES. MODELS HAVE THIS SHORT WAVE MOVING THROUGH EASTERN VIRGINIA ON THURSDAY MORNING. 850 MB WINDS THROUGH THE PERIOD REMAIN IN THE 20 TO 35 KNOT RANGE FROM THE NORTHWEST. RAP GUIDANCE AND LOCAL WRF BOTH INDICATED SOME BANDS OF SNOW SHOWERS MAY DEVELOP BEFORE MIDNIGHT TONIGHT. HAVE ADDED MORE CLOUD COVER IN THE EAST THURSDAY MORNING...WITH THE NEXT SHORT WAVE...OTHERWISE PERSISTENT DOWNSLOPE FLOW WILL LIMIT COVER COVER AND SHOWERS EAST OF THE FOOTHILLS OVERNIGHT. HOWEVER...TEMPERATURES ALOFT REMAIN COLD ENOUGH AND LAPSE RATES DURING THE DAY ARE LARGE ENOUGH THAT MORE SCATTERED STRATOCUMULUS WILL FORM AGAIN BY LATE THURSDAY MORNING. STAYED ON THE COOL SIDE OF GUIDANCE FOR LOWS TONIGHT AND ESPECIALLY HIGHS ON THURSDAY. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... AS OF 200 PM EDT WEDNESDAY... THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE REGION WILL CONTINUE TO BE IN A PATTERN OF NORTHWEST FLOW. HOWEVER...THE VARIOUS SHORTWAVE TROUGHS WITHIN THE LARGER SYNOPTIC PATTERN WITH BE PROGRESSIVELY FARTHER NORTH OF THE REGION. ALSO...THE PRESSURE GRADIENT WILL BE BROADENING...AND THEREFORE...THE MAGNITUDE OF THE UPSLOPE WINDS WILL BE LESS. WHILE WE WILL STILL BE FORECASTING UPSLOPE SNOW SHOWERS/FLURRIES FOR SOUTHEAST WEST VIRGINIA...THE IMPACT WILL BE ALSO BE DECREASING IN TIME. THE ONE CLINKER IN THIS SCENARIO IS THE POTENTIAL FOR SOME LIGHT PRECIPITATION ACROSS THE SOUTHWEST PART OF THE FORECAST AREA FRIDAY NIGHT. THE 12Z/8AM GFS/NAM/CANADIAN SOLUTIONS HAVE BEEN HINTING AT A WEAK DISTURBANCE PROGRESSING THROUGH KY/TN AND INTO SW VA/NW NC. WHILE IT HAS BEEN WEAK...IT HAS BEEN CONSISTENT FROM MODEL RUN TO MODEL RUN. OUR CURRENT FORECAST HAS THIS FEATURE REFLECTED LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING TO A MINIMAL DEGREE. WE WILL SHOW AN INCREASE IN THE POTENTIAL OF A LIGHT MIX OF WINTRY PRECIPITATION IN THIS FORECAST PACKAGE...WHILE STILL MAINTAINING RELATIVELY LOW CHANCES. BY SATURDAY INTO SATURDAY NIGHT...MODEL GUIDANCE IS SUGGESTING WHAT HAS BEEN AN EXTENDED PERIOD OF NORTHWEST FLOW COMES TO AN END AS AN UPPER LEVEL SHORTWAVE RIDGE BUILDS ACROSS THE REGION...AND THE PREVAILING FLOW BECOMES SOUTHWEST. RIDGING OVER THE REGION WILL BE BE BRIEF AS IT DEVELOPS AS A RESULT OF OUR NEXT SHORTWAVE TROUGH PROGRESSING THROUGH THE CENTER OF THE COUNTRY. WITHIN THIS SOUTHWEST FLOW WILL BE A NEW SOURCE OF MOISTURE...THE GULF OF MEXICO. WE WILL EXPERIENCE PATCHY LIGHT RAIN AND INCREASED CLOUD COVER MOVING INTO THE SOUTHWEST PART OF THE AREA AS EARLY AS SATURDAY EVENING. THROUGHOUT SATURDAY NIGHT...THE PRECIPITATION WILL PROGRESS NORTH...AND EXPAND IN COVERAGE...HOWEVER...AMOUNTS ARE EXPECTED TO BE ON THE LIGHT SIDE. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AS OF 1245 PM EDT WEDNESDAY... ON SUNDAY...THE TREND WILL CONTINUE FOR INCREASING CHANCES OF RAIN THROUGHOUT THE MORNING AND AFTERNOON...WITH HEAVIER SHOWERS POSSIBLE ACROSS THE MOUNTAINS DURING THE AFTERNOON THANKS TO THE APPROACH OF A COLD FRONT. TEMPERATURES WILL CONTINUE TO TREND MILDER. LOWS SUNDAY MORNING WILL BE IN THE LOWER 40S ACROSS MUCH OF THE REGION...WITH HIGHER RIDGE TOPS OF SE WV IN THE MID TO UPPER 30S. ON SUNDAY...LOW TO MID 50S FOR HIGHS ARE EXPECTED IN THE MOUNTAINS...WITH UPPER 50S TO AROUND 60 EAST OF THE BLUE RIDGE. SUNDAY NIGHT...THE COLD FRONT CROSSES THE REGION WITH ITS ASSOCIATED PRECIPITATION...AND THEN COLDER AIR STARTS TO RETURN. BY LATE SUNDAY NIGHT...ENOUGH COLD AIR MAY BRING SOME SNOW SHOWERS MIXED WITH THE RAIN SHOWERS TO WESTERN GREENBRIER CO WV. MONDAY THROUGH WEDNESDAY...THE REGION REMAINS WITH A NORTHWEST FLOW PATTERN DURING THIS PERIOD. THIS WILL PUT US BACK IN AN UPSLOPE PATTERN WITH A MIX OF RAIN AND SNOW SHOWERS ACROSS SE WV. THE GFS IS SUGGESTING TUESDAY MAY BE A DAY WITH PRECIPITATION ACROSS A WIDER SWATH OF THE AREA IN ADDITION TO THE UPSLOPE PRECIPITATION. ITS SOLUTION BRINGS A SOUTHERN STREAM SYSTEM ALONG THE GULF COAST STATES AND THEN NORTH ALONG THE COAST ALONG THE FRONTAL BOUNDARY THAT WOULD HAVE CROSS OUR REGION ON SUNDAY. OUR FORECAST WILL OFFER SOME CREDENCE TO THIS POTENTIAL...BUT ONLY WITH A SLIGHT CHANCE OF RAIN SHOWERS IN THE EAST. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... AS OF 200 PM EDT WEDNESDAY... SCATTERED SNOW SHOWERS AND FLURRIES WILL BE PRESENT THROUGHOUT THE AFTERNOON ESPECIALLY AREAS WEST OF THE BLUE RIDGE...CAUSING MVFR CEILINGS AND VISIBILITY...LIGHT TO MODERATE WINDS WITH GUSTS UP TO 25 KNOTS. WHEN THE SUN DIPS BELOW THE HORIZON THE WINDS BECOME LIGHT AND CLOUD COVER WILL BE REDUCED TO CLEAR SKY IN AREAS EAST OF THE BLUE RIDGE...FOR THE WESTERN MOUNTAINS LIGHT SNOW SHOWERS CONTINUE OVERNIGHT. AFTER SUNRISE THE WINDS PICK BACK UP WITH GUSTS 20 TO 25 KNOTS. THE SKY REMAIN CLEAR FOR THE PIEDMONT...LIGHT SNOW SHOWERS ACCOMPANIED BY LOWER CEILINGS WILL REMAIN IN THE AREAS WEST OF THE BLUE RIDGE. BUFKIT SUGGESTED A MORE SHALLOW LAYER OF MOISTURE BUT STILL MVFR CEILINGS AT BLF. HIGHER CONFIDENCE OF VFR CONDITIONS AT LWB/ROA AND BCB EVEN THOUGH THERE MAY BE SNOWFLAKES IN THE AIR. BY FRIDAY THE LOW LEVEL MOISTURE ERODES AND PUTS AN END TO THE UPSLOPE SNOW SHOWERS ACROSS THE MOUNTAINS AND CLEARS OUT THE LOW LEVEL CU. SURFACE HIGH PRESSURE BUILDS IN FOR FRIDAY AND SATURDAY RESULTING IN LIGHTER WINDS AND VFR CONDITIONS. CLOUDS INCREASE AGAIN AHEAD OF ANOTHER FRONT ON SATURDAY NIGHT. DEEPER MOISTURE ALONG WITH THE THREAT OF SHOWERS WILL HOLD OFF UNTIL SUNDAY WHEN MVFR CEILINGS AND VISIBILITIES OR WORSE MAY DEVELOP. A STRONG COLD FRONT IS EXPECTED TO CROSS THROUGH THE REGION..RETURNING BELOW NORMAL TEMPERATURES AND MOUNTAIN SNOW SHOWERS ON MONDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...DS LONG TERM...DS AVIATION...AMS/JH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1043 PM CDT THU MAR 28 2013 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 247 PM CDT THU MAR 28 2013 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH PRESSURE STRETCHING FROM THE SOUTHEAST GULF COAST TO THE WESTERN GREAT LAKES TO HUDSON BAY EARLY THIS AFTERNOON. MOSTLY CLEAR SKIES PREVAIL ACROSS MUCH OF THE STATE AS TEMPERATURES CLIMB INTO THE UPPER 30S TO MID 40S. MEANWHILE OUT WEST...A THIN BAND OF ALTO-STRATUS HAS BEEN SLOWLY FALLING APART TODAY...WHICH IS ALIGNED ALONG A WEAK 850MB BAROCLINIC ZONE. A SOUTHEAST MOVING SHORTWAVE OVER NORTHERN MINNESOTA HAS BEEN BENIGN SO FAR...BUT STARTING TO GET A FEW CU POPPING OVER THE HIGHER TERRAIN OF UPPER MICHIGAN WHICH ARE SPREADING SOUTH. 12Z SOUNDINGS ACROSS THE REGION ARE PRETTY DRY...AND DEWPOINTS HAVE FALLEN INTO THE LOWER TEENS OVER N-C WISCONSIN. WILL STILL TAKE DOWN SKY COVER A COUPLE NOTCHES THROUGH THE REST OF THE AFTERNOON. TEMPS AND CLOUDS ARE THE MAIN FORECAST CONCERNS. TONIGHT...WEAK SHORTWAVE WILL MOVE ACROSS NORTHEAST WISCONSIN WITHOUT MUCH OF AN IMPACT. A RATHER DRY MOISTURE PROFILE WITHIN THE 12Z SOUNDINGS ACROSS THE REGION SUGGEST THERE IS LITTLE HOPE FOR CLOUD COVER SO WILL DROP WORDING INTO THE MOSTLY CLEAR CATEGORY EVERYWHERE. WITH HIGH PRESSURE AND LIGHT WINDS AT THE SURFACE...MOSTLY CLEAR SKIES WILL CAUSE TEMPS TO FALL SIMILAR TO LAST NIGHTS. SO USED MAINLY PERSISTENCE FOR LOW TEMPS FOR THIS FORECAST...AND BLENDED IN THE ORIGINAL FORECAST TO GIVE THEM A COUPLE DEGREES BUMP SINCE AFTERNOON HIGHS WILL BE A TAD WARMER THAN YESTERDAYS. FRIDAY...HIGH PRESSURE WILL REMAIN ACROSS THE AREA WHICH WILL LEAD TO A MOSTLY SUNNY DAY. WEAK WARM ADVECTION WILL ARRIVE OVER CENTRAL WISCONSIN IN THE AFTERNOON...AND MAY PUSH A FEW CLOUDS INTO THAT AREA. OTHERWISE...TEMPS SHOULD BE A COUPLE MORE DEGREES WARMER THAN TODAY...AND WILL GO WITH HIGHS IN THE MID TO UPPER 40S. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 247 PM CDT THU MAR 28 2013 THE LARGE SCALE PATTERN SHOWS A DEVELOPING UPR RDG OVER THE WRN CONUS AND A GENERAL MEAN TROFFING FROM THE PLAINS TO THE MID-ATLANTIC STATES. THERE ARE SIGNS THAT THIS PATTERN WL BREAK DOWN LATER NEXT WEEK AS A NEW UPR TROF HEADS TOWARD THE WEST COAST AND SHOVES THE WRN CONUS UPR RDG EWD INTO THE ROCKIES. MAIN WEATHER FEATURES TO IMPACT NE WI WL BE THE PASSAGE OF A SHORTWAVE TROF/CDFNT THIS WEEKEND AND A POLAR VORTEX SWINGING THRU NRN SECTIONS OF THE GREAT LAKES EARLY NEXT WEEK. TEMPS TO PEAK ON SAT... DROP TO WELL BELOW NORMAL MON...AND RECOVER TO NEAR NORMAL BY NEXT THU. CLOUDS WL STEADILY BE ON THE INCREASE FRI NGT AS THE SFC HI MOVES TOWARD THE ERN GREAT LAKES AND A SHORTWAVE TROF/CDFNT COMBINATION PUSHES E-SE INTO THE UPR MS VALLEY. A PREVAILING SW FLOW ALOFT WL HELP TO INCREASE MOISTURE INTO WI ALONG WITH WAA. THE GFS APPEARS TO SPREAD THE PCPN TOO FAR EAST (INTO FAR NE WI) BY DAYBREAK CONSIDERING THE STRONGEST LIFT TO STILL BE OVER S-CNTRL MN TO NW WI. THEREFORE...PREFER TO FOLLOW THE MAJORITY MDL SOLUTION OF BRINGING THE LEADING EDGE OF PCPN TOWARD CNTRL WI BY 12Z SAT. ONLY CONCERN WOULD BE PCPN TYPE DUE TO SFC TEMPS STILL EXPECTED TO BE BELOW THE FREEZING MARK. N-CNTRL WI COULD SEE A BRIEF PERIOD OF A WINTRY MIX BEFORE TEMPS WARM UP ENUF PAST SUNRISE. EXPECT TEMPS OVER CNTRL WI TO BOTTOM OUT SHORTLY AFTER MIDNGT AND THEN EITHER STEADY OUT OR EVEN RISE A COUPLE OF DEGS. ERN WI SHOULD REACH A TYPICAL SUNRISE MIN TEMP IN THE UPR 20S TO LWR 30S. THE SHORTWAVE TROF/CDFNT REACH THE WRN GREAT LAKES ON SAT WITH A SWATH OF MAINLY RAIN ACROSS THE FCST AREA. ONCE AGAIN...NRN WI MAY SEE MIXED PCPN CARRY OVER TIL AROUND MID-MORNING BEFORE THE ATMOSPHERIC COLUMN WARMS ENUF TO SUSTAIN ALL LIQUID. MDLS ALL POINT 0.25-0.50" OF QPF OVER CNTRL WI BY 00Z SUNDAY AND MAY NEED TO RAISE POPS EVEN MORE. ALL THE CLOUDS AND PCPN WL LIMIT DAYTIME WARMING WITH MOST OF NE WI REACHING THE MID TO UPR 40S. SHORTWAVE TROF/CDFNT PUSH THRU THE REST OF WI PRIMARILY DURING SAT EVENING WITH PCPN CHCS DIMNISHING UPON FROPA. ERN WI TO HAVE THE HIGHEST POPS (LIKELY)...WHILE N-CNTRL WI TO ONLY HAVE A LOW-END CHC POP. AS COLDER AIR RUSHES INTO WI BEHIND THE FNT...THE RAIN WL MIX WITH OR CHANGE TOTALLY TO ALL LIGHT SNOW. MDLS DO SHOW SOME SUBSIDENCE BUILDING THRU CNTRL WI AFTER MIDNGT...THUS ANY LINGERING POPS TO BE RELEGATED TO N-CNTRL WI AND ERN WI. TIMING ISSUES WITH BOTH THE POLAR VORTEX AND SECONDARY CDFNT MAKE SUNDAY`S FCST DIFFICULT AT BEST. THE POLAR VORTEX LOCATION RANGES FROM THE ERN TIP OF LAKE SUPERIOR (GEM) TO SW ONTARIO (GFS) TO WEST OF JAMES BAY (NAM). THIS TIMING DIFFERENCE IS IMPORTANT BECAUSE THIS FEATURE WL HELP TO DRIVE THE CDFNT THRU NE WI EITHER SUNDAY MORNING WITH FALLING AFTERNOON TEMPS OR LATER SUNDAY AFTERNOON WITH TEMPS ABLE TO REACH THE UPR 30S TO LWR 40S. SINCE MODELS CONT TO WAFFLE WITH THE TIMING ASPECT...FEEL A COMPROMISE SOLUTION WOULD WORK BEST WITH A LATER MORNING TO EARLY AFTERNOON FROPA ACCOMPANIED BY EITHER SOME RAIN OR SNOW SHWRS. WINDS WL ALSO STEADILY INCREASE THRU THE DAY AND BECOME RATHER BLUSTERY AT TIMES ONCE THE FNT PASSES THRU. THE WRN GREAT LAKES TO THEN BE LOCKED IN A COLD...CYCLONIC FLWO SUNDAY NGT INTO MON AS THE POLAR VORTEX SWINGS ACROSS SRN ONTARIO INTO SRN QUEBEC. CAA CONTS TO POUR INTO WI AS WINDS VEER MORE TO THE NW AND 8H TEMPS DROP INTO THE LWR TO MID TEENS BELOW ZERO (C). THIS LEADS TO THE POSSIBILITY OF LAKE EFFECT SNOW SHWRS OVER N-CNTRL WI WITH A MINOR ACCUMULATION IN THE FAVORED SNOWBELT OF VILAS CNTY. CANNOT RULE OUT A FEW SNOW SHWRS OVER THE REST OF THE FCST AREA ON MON AS LAPSE RATES STEEPEN AND INSTABILITY INCREASES. AN UNSEASONABLY COOL AND BLUSTERY SPRING DAY ON TAP FOR MON WITH MAX TEMPS TO EASILY BE 15 TO 20 DEGS BELOW NORMAL. SNOW SHWR THREAT FROM LAKE SUPERIOR COULD LINGER OVER N-CNTRL WI RIGHT INTO TUE DEPENDING ON HOW FAST A RDG OF HI PRES BUILDS EWD FROM THE PLAINS. FOR NOW...HAVE KEPT A SMALL POP MAINLY FOR VILAS CNTY MON NGT INTO TUE. THE REST OF NE WI WL REMAIN DRY (OTHER THAN A FEW PASSING FLURRIES MON NGT) WITH A MIX OF SUNY AND CLOUDS ON TUE. TEMPS SHOULD BEGIN A SLOW MODERATING TREND AS THE CORE OF THE COLDEST AIR SHIFTS OFF TO THE EAST. LONG-TERM MDLS ALSO DISAGREE ON WHEN TO SEND THIS SFC RDG THRU THE WRN GREAT LAKES HEADED TOWARD THE MIDDLE OF NEXT WEEK WITH THE GFS ALMOST 12 HOURS FASTER THAN THE ECMWF. WHILE THIS DIFFERENCE WOULD NOT IMPACT THE DRY WEATHER EXPECTED...IT WOULD AFFECT BOTH WIND DIRECTION AND MAX TEMPS. HAVE AGAIN SPLIT THE DIFFERENCE WITH WINDS BACKING S-SW WED AFTERNOON. MDLS NOW BRING A QUICK-MOVING CLIPPER SYSTEM ACROSS SRN CANADA WITH A CDFNT RACING THRU WI WED NGT. GULF MOISTURE IS CUT-OFF...THUS ANY PCPN APPEARS TO BE VERY LIGHT AND SCATTERED AT BEST. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1038 PM CDT THU MAR 28 2013 HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH DAY PERIOD FRI... ASIDE FROM SOME PATCHY MVFR VSBYS IN FOG LATE TONIGHT. BY FRI EVENING HIGH WILL MOVE OFF TO THE EAST WITH INCREASING SOUTHERLY FLOW OVER THE AREA. LOOK FOR INCREASE IN MID LEVEL CLOUDS AND INCREASING DEW POINTS. INCREASING LLVL MOISTURE MAY LEAD TO FOG DEVELOPMENT OVER REMAINING SNOW COVER LATE FRI NIGHT INTO SAT...BEYOND THIS PERIOD. && .HYDROLOGY... ISSUED AT 247 PM CDT THU MAR 28 2013 EXPECT A GRADUAL MODERATION IN TEMPERATURES FOR THE REST OF THE WEEK...WITH HIGHS REACHING INTO MID TO UPPER 40S OVER THE FORECAST AREA ON FRIDAY AND SATURDAY. THIS WILL CONTINUE THE GRADUAL MELTING OF THE SNOWPACK. RAIN OR MIXED PCPN IS EXPECTED THIS WEEKEND...BUT PCPN AMOUNTS SHOULD ONLY BE AROUND A QUARTER INCH. GIVEN THIS SCENARIO...THE EXPECTED RUNOFF SHOULD ONLY CAUSE A GRADUAL RISE IN THE RIVERS OVER CENTRAL AND EAST CENTRAL WISCONSIN BY THE WEEKEND. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KALLAS AVIATION.......TE HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
632 PM CDT THU MAR 28 2013 .SHORT TERM...TONIGHT THROUGH SUNDAY 345 PM CDT THU MAR 28 2013 AT 3 PM...A 1028 MB SURFACE HIGH WAS CENTERED OVER SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN. DESPITE THIS HIGH PRESSURE AREA...A BROKEN DECK OF MID CLOUDS WERE LOCATED ACROSS THIS AFOREMENTIONED AREA. THIS WAS DUE TO MODERATE WARM AIR ADVECTION AHEAD OF A SHORT WAVE MOVING THROUGH SOUTHWEST MINNESOTA. OVERALL THE 28.17Z RAP MODEL IS HANDLING THESE CLOUDS THE BEST. THEY SHOW THAT THESE MID CLOUDS WILL MOVE SOUTHEAST OUT OF THE AREA BY 29.03Z...AND THEN SOME MORE MID CLOUDS WILL MOVE BACK INTO THE AREA FROM WESTERN MINNESOTA AND DAKOTAS AFTER 29.06Z. THESE CLOUDS ARE THE RESULT OF SOME WARM AIR ADVECTION AHEAD OF YET ANOTHER SHORT WAVE TROUGH MOVING OUT OF NORTH DAKOTA. SOUNDINGS SUGGEST THAT THIS MOISTURE WILL LIMITED TO A 100 TO 150 MB LAYER AROUND 700 MB. AS A RESULT...NOT EXPECTING ANY PRECIPITATION FROM THIS WAVE. THIS IS IN DESPITE THE GFS TRYING TO GENERATE SOME PRECIPITATION JUST UPSTREAM OF THE FORECAST AREA. FROM LATE FRIDAY NIGHT INTO SATURDAY EVENING...A STRONG SHORT WAVE TROUGH WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA. AHEAD OF THIS WAVE...THERE WILL BE MODERATE TO STRONG 290K ISENTROPIC LIFT...AND MODERATE 925 MB TO 850 MB MOISTURE TRANSPORT. THIS WILL RESULT IN THE DEVELOPMENT OF A BAND OF RAIN ALONG AND AHEAD OF THIS FRONT. INSTABILITY STILL LOOKS LIMITED WITH MOST UNSTABLE CAPES CLIMBING UP TO 100 J/KG. AS A RESULT...LEFT ISOLATED THUNDERSTORMS IN THE FORECAST MAINLY ALONG AND SOUTH OF INTERSTATE 90. TEMPERATURES AT THE ONSET OF THIS PRECIPITATION MAY RESULT IN A BRIEF WINTRY MIX OF FREEZING RAIN AND SLEET MAINLY NORTHEAST OF INTERSTATE 94. THERE MAY BE A BRIEF PERIOD OF GLAZING. HOWEVER... IT WILL SHORT-LIVED AS TEMPERATURES CLIM QUICKLY INTO THE 40S. ON SUNDAY...A STRONG CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA. THERE IS VERY LITTLE 925 AND 850 MB MOISTURE TRANSPORT ASSOCIATED WITH THIS FRONT. IN THE WAKE OF THIS FRONT...THERE WILL BE MODERATE 290K ISENTROPIC LIFT. HOWEVER SUBSIDENCE IN THE WAKE OF THIS FRONT WILL CAUSE CONDENSATION PRESSURE DEFICITS TO RISE INTO THE 50 TO 100 MB RANGE. AS A RESULT...THERE IS A QUESTION ON WHETHER THERE WILL BE ENOUGH MOISTURE FOR ANY RAIN AND SNOW SHOWERS DURING THE AFTERNOON AND EVENING...THUS...KEPT PRECIPITATION CHANCES ON THE LOW SIDE MAINLY NORTH OF INTERSTATE 94. .LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY 345 PM CDT THU MAR 28 2013 FROM SUNDAY NIGHT INTO TUESDAY...IT CONTINUES TO LOOK LIKE ANOMALOUS COLD AIR MASS WILL BE LOCATED ACROSS THE AREA. THE ECMWF 850 TEMPERATURES ARE RUNNING 1 TO 1.5 STANDARD DEVIATIONS BELOW NORMAL ON MONDAY...AND AROUND 1 STANDARD DEVIATION BELOW NORMAL ON TUESDAY. THIS WILL RESULT IN HIGH TEMPERATURES IN THE LOWER AND MID 30S ON MONDAY...AND IN THE MID AND UPPER 30S ON TUESDAY. ON WEDNESDAY...ANOTHER COLD FRONT WILL MOVE SOUTHEAST THROUGH THE REGION. AT THIS TIME...IT LOOKS LIKE THE BEST MOISTURE AND LIFT WILL BE TO OUR NORTH...THUS KEPT THE FORECAST DRY. LOOKING AHEAD TO THE FIRST HALF OF APRIL...THE CFS VERSION 2 CONTINUES TO SHOW THAT THE AREA WILL SEE PREDOMINANTLY NORTHWEST FLOW. AS A RESULT...IT CONTINUES TO SHOW COLDER-THAN-NORMAL TEMPERATURES PERSISTING THROUGH THIS TIME PERIOD. THE MAIN REASON FOR THIS IS THAT THE ARCTIC OSCILLATION REMAINS NEGATIVE. && .AVIATION...TONIGHT AND FRIDAY 632 PM CDT THU MAR 28 2013 CONTINUED VFR WEATHER WITH MINIMAL CONCERNS NEXT 24 HOURS. SOME WEAK LIFT HAS GENERATED PATCHES OF MID LEVEL CLOUDS BUT THIS WILL REMAIN SCATTERED MOST OF TONIGHT. WITH WARMER TEMPERATURES AND LOW LEVEL WIND STILL ON THE LIGHT SIDE...COULD SEE MINOR REDUCTIONS TO VISIBILITY BUT CONFIDENCE IN ANY IMPACT IS LOW. STRONGER WAVE SHOULD PRODUCE INCREASING CLOUDS LATE ON FRIDAY BUT STILL HAVE DRY LAYERS TO WORK THROUGH. && .HYDROLOGY... 345 PM CDT THU MAR 28 2013 DUE TO A MELTING SNOWPACK OVER THE LAST SEVERAL DAYS...MANY RIVERS ACROSS NORTHEAST IA/SOUTHEAST MN/AND SOUTHWEST WI HAVE EXPERIENCED WITHIN BANK RISES OF 2 TO 4 FEET. IN AREAS WHERE THE SNOW HAS MELTED...SOME OF THE FROST HAS MELTED IN THE TOP FEW INCHES OF THE SOIL...THIS IS ALLOWING SOME OF THE SNOW MELT TO GET INTO THE TOP SOILS. THIS MOISTURE THEN FREEZES IN THE TOP SOILS AT NIGHT. THIS IS LIMITING THE AMOUNT OF RUNOFF INTO THE RIVERS. ON SATURDAY...LOOK FOR A QUARTER TO HALF INCH OF RAIN. THIS WILL ADD ONTO THE RUNOFF FROM THE SNOW MELT. HOWEVER THE WARM RAINS WILL HELP TO MELT SOME FROST IN THE TOP SOILS...SO NOT LOOKING FOR COMPLETE RUNOFF LIKE WE HAD EARLIER IN THE MONTH. WHILE NO FLOODING IS EXPECTED AT THIS TIME...PEOPLE LIVING NEAR OR HAVING INTERESTS ALONG RIVER WAYS ARE URGED TO MONITOR LATEST RIVER FORECASTS AND STATEMENTS. && .ARX WATCHES/WARNINGS/ADVISORIES... 243 PM CDT THU MAR 28 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION....SHEA HYDROLOGY...DAS/BOYNE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
628 PM CDT THU MAR 28 2013 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 247 PM CDT THU MAR 28 2013 THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH PRESSURE STRETCHING FROM THE SOUTHEAST GULF COAST TO THE WESTERN GREAT LAKES TO HUDSON BAY EARLY THIS AFTERNOON. MOSTLY CLEAR SKIES PREVAIL ACROSS MUCH OF THE STATE AS TEMPERATURES CLIMB INTO THE UPPER 30S TO MID 40S. MEANWHILE OUT WEST...A THIN BAND OF ALTO-STRATUS HAS BEEN SLOWLY FALLING APART TODAY...WHICH IS ALIGNED ALONG A WEAK 850MB BAROCLINIC ZONE. A SOUTHEAST MOVING SHORTWAVE OVER NORTHERN MINNESOTA HAS BEEN BENIGN SO FAR...BUT STARTING TO GET A FEW CU POPPING OVER THE HIGHER TERRAIN OF UPPER MICHIGAN WHICH ARE SPREADING SOUTH. 12Z SOUNDINGS ACROSS THE REGION ARE PRETTY DRY...AND DEWPOINTS HAVE FALLEN INTO THE LOWER TEENS OVER N-C WISCONSIN. WILL STILL TAKE DOWN SKY COVER A COUPLE NOTCHES THROUGH THE REST OF THE AFTERNOON. TEMPS AND CLOUDS ARE THE MAIN FORECAST CONCERNS. TONIGHT...WEAK SHORTWAVE WILL MOVE ACROSS NORTHEAST WISCONSIN WITHOUT MUCH OF AN IMPACT. A RATHER DRY MOISTURE PROFILE WITHIN THE 12Z SOUNDINGS ACROSS THE REGION SUGGEST THERE IS LITTLE HOPE FOR CLOUD COVER SO WILL DROP WORDING INTO THE MOSTLY CLEAR CATEGORY EVERYWHERE. WITH HIGH PRESSURE AND LIGHT WINDS AT THE SURFACE...MOSTLY CLEAR SKIES WILL CAUSE TEMPS TO FALL SIMILAR TO LAST NIGHTS. SO USED MAINLY PERSISTENCE FOR LOW TEMPS FOR THIS FORECAST...AND BLENDED IN THE ORIGINAL FORECAST TO GIVE THEM A COUPLE DEGREES BUMP SINCE AFTERNOON HIGHS WILL BE A TAD WARMER THAN YESTERDAYS. FRIDAY...HIGH PRESSURE WILL REMAIN ACROSS THE AREA WHICH WILL LEAD TO A MOSTLY SUNNY DAY. WEAK WARM ADVECTION WILL ARRIVE OVER CENTRAL WISCONSIN IN THE AFTERNOON...AND MAY PUSH A FEW CLOUDS INTO THAT AREA. OTHERWISE...TEMPS SHOULD BE A COUPLE MORE DEGREES WARMER THAN TODAY...AND WILL GO WITH HIGHS IN THE MID TO UPPER 40S. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 247 PM CDT THU MAR 28 2013 THE LARGE SCALE PATTERN SHOWS A DEVELOPING UPR RDG OVER THE WRN CONUS AND A GENERAL MEAN TROFFING FROM THE PLAINS TO THE MID-ATLANTIC STATES. THERE ARE SIGNS THAT THIS PATTERN WL BREAK DOWN LATER NEXT WEEK AS A NEW UPR TROF HEADS TOWARD THE WEST COAST AND SHOVES THE WRN CONUS UPR RDG EWD INTO THE ROCKIES. MAIN WEATHER FEATURES TO IMPACT NE WI WL BE THE PASSAGE OF A SHORTWAVE TROF/CDFNT THIS WEEKEND AND A POLAR VORTEX SWINGING THRU NRN SECTIONS OF THE GREAT LAKES EARLY NEXT WEEK. TEMPS TO PEAK ON SAT... DROP TO WELL BELOW NORMAL MON...AND RECOVER TO NEAR NORMAL BY NEXT THU. CLOUDS WL STEADILY BE ON THE INCREASE FRI NGT AS THE SFC HI MOVES TOWARD THE ERN GREAT LAKES AND A SHORTWAVE TROF/CDFNT COMBINATION PUSHES E-SE INTO THE UPR MS VALLEY. A PREVAILING SW FLOW ALOFT WL HELP TO INCREASE MOISTURE INTO WI ALONG WITH WAA. THE GFS APPEARS TO SPREAD THE PCPN TOO FAR EAST (INTO FAR NE WI) BY DAYBREAK CONSIDERING THE STRONGEST LIFT TO STILL BE OVER S-CNTRL MN TO NW WI. THEREFORE...PREFER TO FOLLOW THE MAJORITY MDL SOLUTION OF BRINGING THE LEADING EDGE OF PCPN TOWARD CNTRL WI BY 12Z SAT. ONLY CONCERN WOULD BE PCPN TYPE DUE TO SFC TEMPS STILL EXPECTED TO BE BELOW THE FREEZING MARK. N-CNTRL WI COULD SEE A BRIEF PERIOD OF A WINTRY MIX BEFORE TEMPS WARM UP ENUF PAST SUNRISE. EXPECT TEMPS OVER CNTRL WI TO BOTTOM OUT SHORTLY AFTER MIDNGT AND THEN EITHER STEADY OUT OR EVEN RISE A COUPLE OF DEGS. ERN WI SHOULD REACH A TYPICAL SUNRISE MIN TEMP IN THE UPR 20S TO LWR 30S. THE SHORTWAVE TROF/CDFNT REACH THE WRN GREAT LAKES ON SAT WITH A SWATH OF MAINLY RAIN ACROSS THE FCST AREA. ONCE AGAIN...NRN WI MAY SEE MIXED PCPN CARRY OVER TIL AROUND MID-MORNING BEFORE THE ATMOSPHERIC COLUMN WARMS ENUF TO SUSTAIN ALL LIQUID. MDLS ALL POINT 0.25-0.50" OF QPF OVER CNTRL WI BY 00Z SUNDAY AND MAY NEED TO RAISE POPS EVEN MORE. ALL THE CLOUDS AND PCPN WL LIMIT DAYTIME WARMING WITH MOST OF NE WI REACHING THE MID TO UPR 40S. SHORTWAVE TROF/CDFNT PUSH THRU THE REST OF WI PRIMARILY DURING SAT EVENING WITH PCPN CHCS DIMNISHING UPON FROPA. ERN WI TO HAVE THE HIGHEST POPS (LIKELY)...WHILE N-CNTRL WI TO ONLY HAVE A LOW-END CHC POP. AS COLDER AIR RUSHES INTO WI BEHIND THE FNT...THE RAIN WL MIX WITH OR CHANGE TOTALLY TO ALL LIGHT SNOW. MDLS DO SHOW SOME SUBSIDENCE BUILDING THRU CNTRL WI AFTER MIDNGT...THUS ANY LINGERING POPS TO BE RELEGATED TO N-CNTRL WI AND ERN WI. TIMING ISSUES WITH BOTH THE POLAR VORTEX AND SECONDARY CDFNT MAKE SUNDAY`S FCST DIFFICULT AT BEST. THE POLAR VORTEX LOCATION RANGES FROM THE ERN TIP OF LAKE SUPERIOR (GEM) TO SW ONTARIO (GFS) TO WEST OF JAMES BAY (NAM). THIS TIMING DIFFERENCE IS IMPORTANT BECAUSE THIS FEATURE WL HELP TO DRIVE THE CDFNT THRU NE WI EITHER SUNDAY MORNING WITH FALLING AFTERNOON TEMPS OR LATER SUNDAY AFTERNOON WITH TEMPS ABLE TO REACH THE UPR 30S TO LWR 40S. SINCE MODELS CONT TO WAFFLE WITH THE TIMING ASPECT...FEEL A COMPROMISE SOLUTION WOULD WORK BEST WITH A LATER MORNING TO EARLY AFTERNOON FROPA ACCOMPANIED BY EITHER SOME RAIN OR SNOW SHWRS. WINDS WL ALSO STEADILY INCREASE THRU THE DAY AND BECOME RATHER BLUSTERY AT TIMES ONCE THE FNT PASSES THRU. THE WRN GREAT LAKES TO THEN BE LOCKED IN A COLD...CYCLONIC FLWO SUNDAY NGT INTO MON AS THE POLAR VORTEX SWINGS ACROSS SRN ONTARIO INTO SRN QUEBEC. CAA CONTS TO POUR INTO WI AS WINDS VEER MORE TO THE NW AND 8H TEMPS DROP INTO THE LWR TO MID TEENS BELOW ZERO (C). THIS LEADS TO THE POSSIBILITY OF LAKE EFFECT SNOW SHWRS OVER N-CNTRL WI WITH A MINOR ACCUMULATION IN THE FAVORED SNOWBELT OF VILAS CNTY. CANNOT RULE OUT A FEW SNOW SHWRS OVER THE REST OF THE FCST AREA ON MON AS LAPSE RATES STEEPEN AND INSTABILITY INCREASES. AN UNSEASONABLY COOL AND BLUSTERY SPRING DAY ON TAP FOR MON WITH MAX TEMPS TO EASILY BE 15 TO 20 DEGS BELOW NORMAL. SNOW SHWR THREAT FROM LAKE SUPERIOR COULD LINGER OVER N-CNTRL WI RIGHT INTO TUE DEPENDING ON HOW FAST A RDG OF HI PRES BUILDS EWD FROM THE PLAINS. FOR NOW...HAVE KEPT A SMALL POP MAINLY FOR VILAS CNTY MON NGT INTO TUE. THE REST OF NE WI WL REMAIN DRY (OTHER THAN A FEW PASSING FLURRIES MON NGT) WITH A MIX OF SUNY AND CLOUDS ON TUE. TEMPS SHOULD BEGIN A SLOW MODERATING TREND AS THE CORE OF THE COLDEST AIR SHIFTS OFF TO THE EAST. LONG-TERM MDLS ALSO DISAGREE ON WHEN TO SEND THIS SFC RDG THRU THE WRN GREAT LAKES HEADED TOWARD THE MIDDLE OF NEXT WEEK WITH THE GFS ALMOST 12 HOURS FASTER THAN THE ECMWF. WHILE THIS DIFFERENCE WOULD NOT IMPACT THE DRY WEATHER EXPECTED...IT WOULD AFFECT BOTH WIND DIRECTION AND MAX TEMPS. HAVE AGAIN SPLIT THE DIFFERENCE WITH WINDS BACKING S-SW WED AFTERNOON. MDLS NOW BRING A QUICK-MOVING CLIPPER SYSTEM ACROSS SRN CANADA WITH A CDFNT RACING THRU WI WED NGT. GULF MOISTURE IS CUT-OFF...THUS ANY PCPN APPEARS TO BE VERY LIGHT AND SCATTERED AT BEST. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 623 PM CDT THU MAR 28 2013 HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. ASIDE FROM SOME PATCHY MVFR VSBYS IN FOG LATE THU NGT...VFR CONDITIONS ARE ANTICIPATED THROUGH THE TAF PERIOD. && .HYDROLOGY... ISSUED AT 247 PM CDT THU MAR 28 2013 EXPECT A GRADUAL MODERATION IN TEMPERATURES FOR THE REST OF THE WEEK...WITH HIGHS REACHING INTO MID TO UPPER 40S OVER THE FORECAST AREA ON FRIDAY AND SATURDAY. THIS WILL CONTINUE THE GRADUAL MELTING OF THE SNOWPACK. RAIN OR MIXED PCPN IS EXPECTED THIS WEEKEND...BUT PCPN AMOUNTS SHOULD ONLY BE AROUND A QUARTER INCH. GIVEN THIS SCENARIO...THE EXPECTED RUNOFF SHOULD ONLY CAUSE A GRADUAL RISE IN THE RIVERS OVER CENTRAL AND EAST CENTRAL WISCONSIN BY THE WEEKEND. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KALLAS AVIATION.......TE HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
525 PM CDT WED MAR 27 2013 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 229 PM CDT WED MAR 27 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE STRETCHING FROM THE GULF COAST UP THE MISSISSIPPI RIVER TO CENTRAL CANADA EARLY THIS AFTERNOON. LINGERING CLOUD COVER AT THE BASE OF THE INVERSION REMAINS ARCED FROM NORTHERN INDIANA TO WESTERN ONTARIO...BUT HAS BEEN SLOWLY BREAKING UP. SKIES BECOME CLEAR ON EITHER SIDE OF THIS ARCING CLOUD BAND WITH TEMPS MAINLY IN THE 30S TO LOWER 40S. CLOUDS AND TEMPS REMAIN THE MAIN FORECAST CONCERNS. TONIGHT...HIGH PRESSURE RIDGE AXIS WILL GRADUALLY MOVE EAST FROM THE NORTHERN MISSISSIPPI VALLEY INTO WESTERN WISCONSIN. OVERCAST 5-6KFT CLOUD DECK HAS BECOME THINNER BASED OFF OF 12Z SOUNDINGS...AND STARTED TO BREAK UP BY LATE IN THE MORNING. BUT STILL NOT AN EASY CLOUD FORECAST TONIGHT. BASED ON THE RATE OF CLEARING SO FAR TODAY...WENT MORE OPTIMISTIC WITH SKY COVER THIS EVENING...AND SHOW MOSTLY CLEAR SKIES ARRIVING BY MIDNIGHT EXCEPT FOR WESTERN SECTIONS OF THE CWA. FORECASTED LOWS ARE DEPENDENT UPON CLEARING AGAIN SO CONFIDENCE IS LOW ONCE AGAIN. WILL GO WITH LOWS MAINLY IN THE 20S EXCEPT A FEW COLD SPOTS MAY DROP A COUPLE DEGREES COLDER. THURSDAY...HIGH PRESSURE WILL BE OVER THE REGION...LEADING TO ANOTHER QUIET DAY. A MOSTLY CLEAR TO PARTLY CLOUDY START TO THE DAY...WILL SEE DIURNAL CU BUILD BY EARLY IN THE AFTERNOON. HIGHS A COUPLE DEGREES WARMER INTO THE LOW TO MID 40S. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 229 PM CDT WED MAR 27 2013 SPLIT FLOW OVER THE ERN PACIFIC CONTS TO GIVE THE MDLS FITS AS TO WHAT THE FLOW WL DO DOWNSTREAM OVER THE CONUS. LATEST TREND IS TO BRING A NRN BRANCH SYSTEM THRU THE GREAT LAKES THIS WEEKEND...THEN SWING A POLAR VORTEX SOUTH/THEN EAST ACROS SRN ONTARIO/SRN QUEBEC EARLY NEXT WEEK. THIS TREND WOULD BRING UNSETTLED WEATHER TO NE WI DURING THE WEEKEND/MON...TO BE FOLLOWED BY A DRYING TREND THEREAFTER. TEMPS SHOULD BE AT OR EVEN SLIGHTLY ABOVE NORMAL INTO THE WEEKEND AND THEN COOL TO BELOW NORMAL LEVELS FOR THE FIRST HALF OF NEXT WEEK. RDG OF HI PRES TO EXTEND FROM THE UPR MS VALLEY SEWD THRU WI TO THE TN VALLEY REGION THU NGT. ANY DAYTIME CU FIELD WL DISSIPATE UPON SUNSET LEAVING GENERALLY MOSTLY CLEAR SKIES AND LIGHT WINDS OVER NE WI. THIS SYNOPTIC SET-UP COULD BRING SOME LATE NIGHT FOG INTO THE AREA AS MELTING SNOW ADDS MOISTURE TO THE ATMOSPHERE. MIN TEMPS ARE EXPECTED TO DIP INTO THE UPR TEENS NORTH...MID 20S E-CNTRL WI. THIS SFC RDG AXIS SLIDES ACROSS WI FRI MORNING AND BE TO OUR EAST BY THE AFTERNOON HOURS. LIGHT W-NW WINDS WL BACK W-SW WITH WEAK WAA BEGINNING IN THE AFTERNOON. UNDER MOSTLY SUNNY SKIES...MAX TEMPS SHOULD BE ABLE TO RANGE FROM THE LWR TO MID 40S NORTH...MID TO UPR 40S CNTRL/E-CNTRL WI. ONLY EXCEPTION MIGHT BE ALONG LAKE MI WHERE AN ONSHORE WIND MAY KEEP READINGS IN THE LWR 40S. AS THE NEXT WEATHER SYSTEM (IN THE FORM OF A CDFNT AND SHORTWAVE TROF) DROPS SE THRU THE NRN PLAINS AND REACHES THE UPR MIDWEST BY DAYBREAK...SW WINDS WL BEGIN TO DRAW MOISTURE TOWARD WI WHICH WL GRADUALLY INCREASE CLOUDS ACROSS WI. MAY NEED TO RAISE TEMPS OVER CNTRL WI WHERE THE CLOUDS TO REACH FIRST BY A FEW DEGS (UPR 20S TO AROUND 30) WHILE KEEPING ERN WI SIMILAR TO THE PREVIOUS FCST (UPR 20S). MDLS CONT TO SHOW THE APPROACH OF A SFC CDFNT/MID-LEVEL SHORWAVE TROF TOWARD THE WRN GREAT LAKES ON SAT. SOUTH WINDS IN PLACE AHEAD OF THIS SYSTEM WL BRING AN INCREASE IN BOTH MOISTURE AND ISEN LIFT TO WI AND EXPECT TO SEE PCPN CHCS INCREASE FROM WEST TO EAST... ESPECIALLY AS BETTER MOISTURE CONVERGENCE/FORCING ARRIVE. THERE COULD BE A LINGERING PCPN TYPE ISSUE OVER CNTRL WI EARLY SAT MORNING WITH SFC TEMPS BELOW 32 DEGS AND A SMALL LAYER OF ABOVE FREEZING TEMPS JUST ABOVE THE SFC. MAY NEED TO MENTION A LITTLE SLEET INITIALLY BEFORE THE PCPN TRANSITIONS TO EITHER ALL RAIN OR A RAIN/SNOW MIX BY MID-MORNING. BY SAT AFTERNOON...TEMPS TO HAVE WARMED ENUF TO CARRY HI CHC POPS OF RAIN FOR THE ENTIRE FCST AREA. CDFNT/SHORTWAVE TROF PUSH THRU WI MAINLY SAT EVENING (PERHAPS AROUND MIDNGT OVER THE EAST)...THUS WL CONT THE NEED FOR POPS IN THE FCST. PCPN TYPE TIMING REMAINS AN ISSUE DEPENDING ON HOW FAST COOLER AIR SPREADS INTO THE REGION BEHIND THE CDFNT. HAVE ATTEMPTED TO SHOW THIS GRADUAL TRANSITION IN THE GRIDS WITH N-CNTRL WI ALL SNOW BY MIDNGT AND RAIN BECOMING MIXED WITH SNOW AFTER MIDNGT E-CNTRL WI. DO NOT EXPECT MUCH IN THE WAY OF ACCUMULATION SAT NGT AS BETTER MOISTURE TO ALREADY HAVE BEEN SHUNTED EAST BY THE TIME THE COOLER AIR ARRIVES. MDL DIFFERENCES REMAIN ON SUNDAY AS THE GFS DRIVES A SECONDARY CDFNT THRU WI...WHILE THE REST OF THE MDLS HOLD THIS SECOND FNT BACK OVER NRN SECTIONS OF THE GREAT LAKES. IF THE LATTER SOLUTION IS CORRECT...PCPN CHCS MAY BE LIMITED TO NRN WI CLOSER TO THE FNT AND A SHORTWAVE ROTATING SEWD TOWARD THE WRN GREAT LAKES. WOULD STILL EXPECT A DECENT AMOUNT OF CLOUDS IN THIS COLD...CYCLONIC PATTERN LEFT OVER THE STATE ON SUNDAY WITH MAX TEMPS DIPPING INTO THE UPR 30S TO MID 40S. THIS SECOND CDFNT TO DROP SOUTH INTO CNTRL SECTIONS OF WI SUNDAY NGT AND SHOVE OUT OF WI ALTOGETHER ON MON. SOME SNOW SHWRS MAY ACCOMPANY THIS FROPA...BUT THE MAIN FOCUS FOR SNOW SHWR ACTIVITY WOULD BE LAKE EFFECT OVER N-CNTRL WI AS 8H TEMPS OVER LAKE SUPERIOR DROP TO AROUND -17C BY 12Z MON...DELTA-T`S CLIMB INTO THE UPR TEENS AND THERE IS LITTLE IN THE WAY OF ANY LOW-LEVEL INVERSIONS. THE ONLY THING LACKING IS FAVORABLE TRAJS AS WINDS TO BE FROM THE W-NW. NEVERTHELESS...WL CARRY A MEDIUM CHC POP FOR VILAS CNTY SUNDAY NGT INTO MON WITH LESSER POPS FARTHER SOUTH AS THE CYCLONIC FLOW PERSISTS THRU MON. THE LAKE EFFECT FOR N-CNTRL WI COULD LINGER INTO TUE MORNING BEFORE A LARGE AREA OF HI PRES OVER THE NRN PLAINS BEGINS TO BUILD EWD AND SENDS ENUF DRY AIR TOWARD WI TO END THE LAKE EFFECT. THE REST OF NE WI WL SEE A DECENT AMOUNT OF SUNSHINE...ALBEIT WITH BELOW NORMAL TEMPS. THIS HI PRES THEN OVERSPREADS THE WRN GREAT LAKES BY NEXT WED WHICH WL BRING A MIX OF SUN AND CLOUDS ALONG WITH LIGHT WINDS. TEMPS SHOULD BEGIN A SLOW MODERATION WITH MAX TEMPS REACHING THE UPR 30S TO LWR 40S. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 520 PM CDT WED MAR 27 2013 HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE TAF PERIOD. FEW LINGERING CLOUDS EXPECTED TO DISSIPATE WITH SUNSET...WITH SOME DIURNAL CU EXPECTED AGAIN ON THU. MOISTURE WITH MELTING SNOW MAY LEAD TO PATCHY FOG LATE TONIGHT CENTRAL AND NORTH CENTRAL WITH EXPECTED LIGHT WINDS. WILL KEEP IN RHI TAF ATTM...THOUGH NOT CONFIDENT ENOUGH TO ADD ANYWHERE ELSE. VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. && .HYDROLOGY... ISSUED AT 229 PM CDT WED MAR 27 2013 EXPECT A GRADUAL MODERATION IN TEMPERATURES FOR THE REST OF THE WEEK...WITH HIGHS REACHING INTO MID TO UPPER 40S OVER THE FORECAST AREA THIS WEEKEND. THIS WILL RESULT IN A GRADUAL MELTING OF THE SNOWPACK. RAIN OR MIXED PCPN IS EXPECTED THIS WEEKEND...BUT PCPN AMOUNTS SHOULD BE FAIRLY LIGHT. GIVEN THIS SCENARIO...THE EXPECTED RUNOFF SHOULD ONLY CAUSE A GRADUAL RISE IN THE RIVERS OVER CENTRAL AND EAST CENTRAL WISCONSIN BY THE WEEKEND. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KALLAS AVIATION.......TE HYDROLOGY......MPC
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 229 PM CDT WED MAR 27 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE STRETCHING FROM THE GULF COAST UP THE MISSISSIPPI RIVER TO CENTRAL CANADA EARLY THIS AFTERNOON. LINGERING CLOUD COVER AT THE BASE OF THE INVERSION REMAINS ARCED FROM NORTHERN INDIANA TO WESTERN ONTARIO...BUT HAS BEEN SLOWLY BREAKING UP. SKIES BECOME CLEAR ON EITHER SIDE OF THIS ARCING CLOUD BAND WITH TEMPS MAINLY IN THE 30S TO LOWER 40S. CLOUDS AND TEMPS REMAIN THE MAIN FORECAST CONCERNS. TONIGHT...HIGH PRESSURE RIDGE AXIS WILL GRADUALLY MOVE EAST FROM THE NORTHERN MISSISSIPPI VALLEY INTO WESTERN WISCONSIN. OVERCAST 5-6KFT CLOUD DECK HAS BECOME THINNER BASED OFF OF 12Z SOUNDINGS...AND STARTED TO BREAK UP BY LATE IN THE MORNING. BUT STILL NOT AN EASY CLOUD FORECAST TONIGHT. BASED ON THE RATE OF CLEARING SO FAR TODAY...WENT MORE OPTIMISTIC WITH SKY COVER THIS EVENING...AND SHOW MOSTLY CLEAR SKIES ARRIVING BY MIDNIGHT EXCEPT FOR WESTERN SECTIONS OF THE CWA. FORECASTED LOWS ARE DEPENDENT UPON CLEARING AGAIN SO CONFIDENCE IS LOW ONCE AGAIN. WILL GO WITH LOWS MAINLY IN THE 20S EXCEPT A FEW COLD SPOTS MAY DROP A COUPLE DEGREES COLDER. THURSDAY...HIGH PRESSURE WILL BE OVER THE REGION...LEADING TO ANOTHER QUIET DAY. A MOSTLY CLEAR TO PARTLY CLOUDY START TO THE DAY...WILL SEE DIURNAL CU BUILD BY EARLY IN THE AFTERNOON. HIGHS A COUPLE DEGREES WARMER INTO THE LOW TO MID 40S. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 229 PM CDT WED MAR 27 2013 SPLIT FLOW OVER THE ERN PACIFIC CONTS TO GIVE THE MDLS FITS AS TO WHAT THE FLOW WL DO DOWNSTREAM OVER THE CONUS. LATEST TREND IS TO BRING A NRN BRANCH SYSTEM THRU THE GREAT LAKES THIS WEEKEND...THEN SWING A POLAR VORTEX SOUTH/THEN EAST ACROS SRN ONTARIO/SRN QUEBEC EARLY NEXT WEEK. THIS TREND WOULD BRING UNSETTLED WEATHER TO NE WI DURING THE WEEKEND/MON...TO BE FOLLOWED BY A DRYING TREND THEREAFTER. TEMPS SHOULD BE AT OR EVEN SLIGHTLY ABOVE NORMAL INTO THE WEEKEND AND THEN COOL TO BELOW NORMAL LEVELS FOR THE FIRST HALF OF NEXT WEEK. RDG OF HI PRES TO EXTEND FROM THE UPR MS VALLEY SEWD THRU WI TO THE TN VALLEY REGION THU NGT. ANY DAYTIME CU FIELD WL DISSIPATE UPON SUNSET LEAVING GENERALLY MOSTLY CLEAR SKIES AND LIGHT WINDS OVER NE WI. THIS SYNOPTIC SET-UP COULD BRING SOME LATE NIGHT FOG INTO THE AREA AS MELTING SNOW ADDS MOISTURE TO THE ATMOSPHERE. MIN TEMPS ARE EXPECTED TO DIP INTO THE UPR TEENS NORTH...MID 20S E-CNTRL WI. THIS SFC RDG AXIS SLIDES ACROSS WI FRI MORNING AND BE TO OUR EAST BY THE AFTERNOON HOURS. LIGHT W-NW WINDS WL BACK W-SW WITH WEAK WAA BEGINNING IN THE AFTERNOON. UNDER MOSTLY SUNNY SKIES...MAX TEMPS SHOULD BE ABLE TO RANGE FROM THE LWR TO MID 40S NORTH...MID TO UPR 40S CNTRL/E-CNTRL WI. ONLY EXCEPTION MIGHT BE ALONG LAKE MI WHERE AN ONSHORE WIND MAY KEEP READINGS IN THE LWR 40S. AS THE NEXT WEATHER SYSTEM (IN THE FORM OF A CDFNT AND SHORTWAVE TROF) DROPS SE THRU THE NRN PLAINS AND REACHES THE UPR MIDWEST BY DAYBREAK...SW WINDS WL BEGIN TO DRAW MOISTURE TOWARD WI WHICH WL GRADUALLY INCREASE CLOUDS ACROSS WI. MAY NEED TO RAISE TEMPS OVER CNTRL WI WHERE THE CLOUDS TO REACH FIRST BY A FEW DEGS (UPR 20S TO AROUND 30) WHILE KEEPING ERN WI SIMILAR TO THE PREVIOUS FCST (UPR 20S). MDLS CONT TO SHOW THE APPROACH OF A SFC CDFNT/MID-LEVEL SHORWAVE TROF TOWARD THE WRN GREAT LAKES ON SAT. SOUTH WINDS IN PLACE AHEAD OF THIS SYSTEM WL BRING AN INCREASE IN BOTH MOISTURE AND ISEN LIFT TO WI AND EXPECT TO SEE PCPN CHCS INCREASE FROM WEST TO EAST... ESPECIALLY AS BETTER MOISTURE CONVERGENCE/FORCING ARRIVE. THERE COULD BE A LINGERING PCPN TYPE ISSUE OVER CNTRL WI EARLY SAT MORNING WITH SFC TEMPS BELOW 32 DEGS AND A SMALL LAYER OF ABOVE FREEZING TEMPS JUST ABOVE THE SFC. MAY NEED TO MENTION A LITTLE SLEET INITIALLY BEFORE THE PCPN TRANSITIONS TO EITHER ALL RAIN OR A RAIN/SNOW MIX BY MID-MORNING. BY SAT AFTERNOON...TEMPS TO HAVE WARMED ENUF TO CARRY HI CHC POPS OF RAIN FOR THE ENTIRE FCST AREA. CDFNT/SHORTWAVE TROF PUSH THRU WI MAINLY SAT EVENING (PERHAPS AROUND MIDNGT OVER THE EAST)...THUS WL CONT THE NEED FOR POPS IN THE FCST. PCPN TYPE TIMING REMAINS AN ISSUE DEPENDING ON HOW FAST COOLER AIR SPREADS INTO THE REGION BEHIND THE CDFNT. HAVE ATTEMPTED TO SHOW THIS GRADUAL TRANSITION IN THE GRIDS WITH N-CNTRL WI ALL SNOW BY MIDNGT AND RAIN BECOMING MIXED WITH SNOW AFTER MIDNGT E-CNTRL WI. DO NOT EXPECT MUCH IN THE WAY OF ACCUMULATION SAT NGT AS BETTER MOISTURE TO ALREADY HAVE BEEN SHUNTED EAST BY THE TIME THE COOLER AIR ARRIVES. MDL DIFFERENCES REMAIN ON SUNDAY AS THE GFS DRIVES A SECONDARY CDFNT THRU WI...WHILE THE REST OF THE MDLS HOLD THIS SECOND FNT BACK OVER NRN SECTIONS OF THE GREAT LAKES. IF THE LATTER SOLUTION IS CORRECT...PCPN CHCS MAY BE LIMITED TO NRN WI CLOSER TO THE FNT AND A SHORTWAVE ROTATING SEWD TOWARD THE WRN GREAT LAKES. WOULD STILL EXPECT A DECENT AMOUNT OF CLOUDS IN THIS COLD...CYCLONIC PATTERN LEFT OVER THE STATE ON SUNDAY WITH MAX TEMPS DIPPING INTO THE UPR 30S TO MID 40S. THIS SECOND CDFNT TO DROP SOUTH INTO CNTRL SECTIONS OF WI SUNDAY NGT AND SHOVE OUT OF WI ALTOGETHER ON MON. SOME SNOW SHWRS MAY ACCOMPANY THIS FROPA...BUT THE MAIN FOCUS FOR SNOW SHWR ACTIVITY WOULD BE LAKE EFFECT OVER N-CNTRL WI AS 8H TEMPS OVER LAKE SUPERIOR DROP TO AROUND -17C BY 12Z MON...DELTA-T`S CLIMB INTO THE UPR TEENS AND THERE IS LITTLE IN THE WAY OF ANY LOW-LEVEL INVERSIONS. THE ONLY THING LACKING IS FAVORABLE TRAJS AS WINDS TO BE FROM THE W-NW. NEVERTHELESS...WL CARRY A MEDIUM CHC POP FOR VILAS CNTY SUNDAY NGT INTO MON WITH LESSER POPS FARTHER SOUTH AS THE CYCLONIC FLOW PERSISTS THRU MON. THE LAKE EFFECT FOR N-CNTRL WI COULD LINGER INTO TUE MORNING BEFORE A LARGE AREA OF HI PRES OVER THE NRN PLAINS BEGINS TO BUILD EWD AND SENDS ENUF DRY AIR TOWARD WI TO END THE LAKE EFFECT. THE REST OF NE WI WL SEE A DECENT AMOUNT OF SUNSHINE...ALBEIT WITH BELOW NORMAL TEMPS. THIS HI PRES THEN OVERSPREADS THE WRN GREAT LAKES BY NEXT WED WHICH WL BRING A MIX OF SUN AND CLOUDS ALONG WITH LIGHT WINDS. TEMPS SHOULD BEGIN A SLOW MODERATION WITH MAX TEMPS REACHING THE UPR 30S TO LWR 40S. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1232 PM CDT WED MAR 27 2013 HIGH PRESSURE WILL SLOWLY MOVE INTO THE REGION OVER THE TAF PERIOD. PESKY 5-6KFT CLOUD DECK WILL LIKELY REMAIN IN PLACE THROUGH THIS EVENING BEFORE GRADUALLY DISSIPATING. DIURNAL CU TO BUILD MIDDAY OVER NE WISCONSIN THEN DIMINISH EARLY THIS EVENING. IN GENERAL THOUGH...VFR CONDITIONS THROUGH THE TAF PERIOD. && .HYDROLOGY... ISSUED AT 229 PM CDT WED MAR 27 2013 EXPECT A GRADUAL MODERATION IN TEMPERATURES FOR THE REST OF THE WEEK...WITH HIGHS REACHING INTO MID TO UPPER 40S OVER THE FORECAST AREA THIS WEEKEND. THIS WILL RESULT IN A GRADUAL MELTING OF THE SNOWPACK. RAIN OR MIXED PCPN IS EXPECTED THIS WEEKEND...BUT PCPN AMOUNTS SHOULD BE FAIRLY LIGHT. GIVEN THIS SCENARIO...THE EXPECTED RUNOFF SHOULD ONLY CAUSE A GRADUAL RISE IN THE RIVERS OVER CENTRAL AND EAST CENTRAL WISCONSIN BY THE WEEKEND. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KALLAS AVIATION.......MPC HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
602 AM CDT WED MAR 27 2013 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT 332 AM CDT WED MAR 27 2013 MAIN FORECAST CONCERNS THIS PACKAGE...CLOUD AND TEMPERATURE TRENDS TODAY THROUGH FRI...PRECIP CHANCES/TYPES LATE FRI NIGHT. DATA ANALYSIS AT 06Z HAD THE SFC HIGH PRESSURE RIDGE AXIS FROM NEAR LK WINNIPEG TO EASTERN MO. CONSIDERABLE STRATUS REMAINED OVER WI/ EASTERN MN/NORTHERN IL EAST OF THE SFC-850MB RIDGE AXIS. CLOUD DECK HELPING KEEP TEMPS ON THE MILD SIDE EARLY THIS MORNING...WITH READINGS UNDER THE CLOUDS MOSTLY IN THE UPPER 20S TO MID 30S. SHORTWAVE SEEN IN WV IMAGERY OVER EASTERN SD/NEB WAS SPREADING SOME HIGH CLOUDS OVER SOUTHERN MN/WESTERN IA...WITH TEMPS IN THESE AREAS FREE OF THE STRATUS IN THE MID-UPPER 20S. UNDER THE RIDGE AXIS WITH CLEAR SKIES...TEMPS ACROSS WEST-CENTRAL/NORTHWEST MN WERE AGAIN IN THE SINGLE DIGITS AND TEENS. 27.00Z MODELS LOOK TO HAVE INITIALIZED WITHOUT SIGNIFICANT ERRORS. SOLUTIONS RATHER SIMILAR FOR TODAY THRU FRI NIGHT AS THE LONGWAVE FLOW PATTERN SLOWLY PROGRESSES AND HGTS GRADUALLY RISE OVER THE REGION THRU FRI...THEN FALL FRI NIGHT WITH THE APPROACH OF A STRONGER SHORTWAVE. DPROG/DT OF 500MB HGTS AT 27.00Z SHOWED THE MODEL RUNS OF 25.00Z AND 26.00Z VERIFIED VERY WELL ACROSS NOAM/ EASTERN PAC...WITH A TREND FAVORING STRONGER OF EARLIER RUNS ON THE SHORTWAVE APPROACHING THE OR/WA COAST. MODELS OFFER A GOOD CONSENSUS FOR TODAY THRU THU NIGHT AS HGTS OVER THE CENTRAL/WESTERN CONUS GRADUALLY RISE AND WEAK SHORTWAVES IN THE NORTHWEST FLOW ALOFT RIPPLE SOUTHEAST ACROSS THE NORTH-CENTRAL CONUS. CONSISTENCY IMPROVING AS A STRONGER SHORTWAVE TROUGH DROPS INTO THE NORTH- CENTRAL CONUS FRI NIGHT. OVERALL TREND IS A BIT STRONGER WITH THIS TROUGH BY 12Z SAT. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED MODELS GOOD WITH THE SFC RIDGE AXIS OVER THE CENTRAL CONUS INTO CAN. MODELS STRUGGLING A BIT WITH SFC DEW POINTS OVER THE NORTH-CENTRAL CONUS... AS THEY ARE WITH THE STRATUS CLOUDS/MOISTURE EAST OF THE LOW LEVEL RIDGE AXIS. NAM LOOKED BETTER WITH THESE CLOUDS/MOISTURE...AS DID LOCAL/REGIONAL HI-RES WRF MODELS. PER WV IMAGERY...ALL LOOKED GOOD WITH THE NOAM/EASTERN PAC SHORTWAVE DETAILS. FAVORED NAM/HI-RES WRF MODELS FOR THE CLOUD TRENDS TODAY/TONIGHT...THEN WITH MODELS TRENDING TOWARD A TIGHTER CONSENSUS THU THRU FRI NIGHT FAVORED THE MODEL/ENSEMBLE CONSENSUS. SHORT-TERM FCST CONFIDENCE AVERAGE TO GOOD THIS CYCLE. IN THE SHORT TERM...NAM/SHORT-TERM HI-RES MODELS INDICATE MOISTURE/ CLOUDS IN THE 850-800MB LAYER WILL REMAIN RATHER PERSISTENT THRU THE MORNING...AND INCREASED/HELD ONTO MORE CLOUDS ALONG/EAST OF THE MS RIVER THRU THE MORNING. ALL MODELS INDICATE SOME EASTWARD PUSH OF THE MOISTURE/CLOUDS THRU THE AFTERNOON/EVENING AS THE SFC-850MB RIDGE AXIS AND SOME SUBSIDENCE MOVES INTO EASTERN MN TO WESTERN IL. CLOUDS /OR NOT/ TO HAVE AN IMPACT ON TEMPS TODAY. WARMER START IN THE EASTERN HALF OF THE FCST AREA VS. THE WEST HALF...BUT MORE SUN IN THE WEST HALF TODAY VS. THE EAST HALF. RAISED HIGHS A BIT OVER THE WEST END OF THE FCST WITH LATE MARCH SUNSHINE LOOKING TO OFFSET THE COLDER START AND SLOWLY DIMINISHING SNOW COVER. MOISTURE/STRATUS FINALLY MOVE EAST OF THE AREA TONIGHT WITH THE SFC-850MB RIDGE AXIS MOVING IN AND A MORE WESTERLY COMPONENT TO THE 850-700MB WIND FLOW. LIGHT WINDS/CLEAR-MOSTLY CLEAR SKIES AND RESIDUAL SNOW COVER SHOULD ALLOW FOR STRONG RADIATIONAL COOLING AND LOWS DROPPING WELL BELOW NORMAL. AT THE SAME TIME...EXPECTED ABUNDANT LATE MARCH SUNSHINE ON THU ALONG WITH SOME WEAK 925-850MB WARM ADVECTION SHOULD ALLOW FOR STRONG DIURNAL WARMING...EVEN OVER THE SNOW COVER. LOW LEVEL WARM ADVECTION CONTINUES/STRENGTHENS THU NIGHT FRI AS THE LOW LEVEL RIDGE AXIS SLOWLY DRIFTS EAST OF THE AREA. WEAK SHORTWAVES RIPPLING THRU THE NORTHWEST FLOW SPREAD SOME MID TO HIGH LEVEL MOISTURE ACROSS THE AREA FROM TIME TO TIME THU THRU FRI. THIS LOOKS TO REMAIN QUITE TRANSIENT WITH SKIES GENERALLY PARTLY CLOUDY TO MOSTLY CLEAR THU NIGHT/FRI. LEAD PIECE OF ENERGY WITH THE STRONGER TROUGH DROPPING INTO THE NORTH-CENTRAL CONUS HEADS TOWARD THE AREA FRI NIGHT. MOISTURE INCREASE AND LIFT WITH WARM ADVECTION/ISENTROPIC UPGLIDE IN THE 925- 700MB SPREAD SOUTHEAST INTO THE AREA LATER FRI NIGHT AHEAD OF/WITH THE LOW LEVEL TROUGH/FRONT. THIS ALONG WITH THE PV ADVECTION/LIFT ALOFT WITH THE LEAD SHORTWAVE. A LOT OF DRY AIR TO OVERCOME BEFORE PRECIP WOULD OCCUR BUT ECMWF/GEM/GFS HAVE NEAR OR INTO THE NORTHWEST END OF THE FCST AREA BY 12Z SAT. HONORED THIS WITH A 20- 30 PERCENT CHANCE OF PRECIP OVER THE NORTHWEST 1/3 OF THE FCST AREA LATE FRI NIGHT. PRECIP TYPE PRESENTS SOME PROBLEMS WITH BOUNDARY LAYER TEMPS LOOKING TO BE BELOW 32F LATER FRI NIGHT. LOWS FRI NIGHT LOOK TO BE AROUND MIDNIGHT WITH STEADY SLOWLY RISING TEMPS LATE AS CLOUDS THICKEN AND TEMPS ALOFT WARM. THE LOW LEVEL WARM ADVECTION PUSHES 925-850MB TEMPS ABOVE 0C AFTER MIDNIGHT FRI NIGHT. ADDED A SLEET/-FZRA MENTION TO PRECIP CHANCES LATER FRI NIGHT TO ACCOUNT FOR THE WARMING LAYER ALOFT AND COLD BOUNDARY LAYER. USED A BLEND OF THE NUMERICAL GUIDANCE HIGHS/LOWS FOR TODAY THRU FRI NIGHT. IF CLOUDS CLEAR FASTER EASTWARD TODAY...HIGHS ALONG THE MS RIVER MAY END UP A CATEGORY TOO COOL. IF SKIES STAY CLEAR/MOSTLY CLEAR WITH THE LIGHT WINDS THU NIGHT...CONSENSUS LOWS MAY BE A CATEGORY OR TWO TOO WARM...ESPECIALLY IN THE NORMALLY COLDER SHELTERED LOCATIONS. .LONG TERM...SATURDAY THROUGH TUESDAY 332 AM CDT WED MAR 27 2013 27.00Z MEDIUM RANGE MODELS IN GOOD AGREEMENT ON A LEAD SHORTWAVE AND A SFC-700MB TROUGH TO PUSH SOUTHEAST ACROSS THE AREA SAT. THIS HAS BEEN A RATHER CONSISTENT SIGNAL SINCE THE 25.00Z RUNS WITH ALL MODELS NOW PRODUCING SOME LIGHT TO LOCALLY MODERATE PRECIP ACROSS THE FCST AREA. RAISE PRECIP CHANCES INTO THE 55 TO 65 PERCENT RANGE OVER MOST OF THE FCST AREA. COLUMN MAY STILL BE COLD ENOUGH FOR SOME MIXED PRECIP TYPES EARLY SAT MORNING...MAINLY OVER THE NORTH END OF THE FCST AREA...BUT MAINLY -RA EXPECTED WITH THE PASSAGE OF THIS SYSTEM ON SAT. CONFIDENCE GOOD WITH THE PRECIP CHANCES SAT... BUT LESSER CONFIDENCE ON HIGH TEMPS. WITH MORE CLOUDS/-RA SPREADING INTO THE AREA SAT MORNING...HIGHS ACROSS MUCH OF THE AREA MAY STRUGGLE TO CLIMB ABOVE THE LOW-MID 40S BUT WILL LEAVE THE CONSENSUS UPPER 40S-LOW 50S HIGHS FOR NOW. MODELS CONTINUE TO DIVERGE ON THE DETAILS OF WHAT HAPPENS BEHIND THIS SYSTEM SAT NIGHT/SUN. TIGHTENING CONSENSUS BUT GFS REMAINS FASTER WITH COLDER AIR POURING IN BEHIND THIS SYSTEM SAT NIGHT. GEM NOW IT ITS CAMP BUT ECMWF MAINTAINS A SECOND FRONT AND THE COLDER AIR TO DROP ACROSS THE AREA LATER SUN/SUN NIGHT. EITHER WAY...SUNDAY TRENDS COOLER THAN SAT WITH PLENTY OF CLOUDS...NORTHWEST WINDS AND MDT TO STRONG LOW LEVEL COLD ADVECTION ACROSS MN/IA/WI. SMALL PRECIP CHANCE SUNDAY IN COOLING CYCLONIC FLOW REASONABLE. IMPROVING/BETTER MODEL CONSISTENCY FOR COLD...CANADIAN HIGH PRESSURE TO BE SETTLING INTO THE REGION FOR MON/TUE...WITH TEMPS AGAIN WELL BELOW NORMAL. THIS WELL HANDLED IN DAYS 6/7 BY THE MODEL/ENSEMBLE CONSENSUS DATA SET. && .AVIATION...TODAY AND TONIGHT 602 AM CDT WED MAR 27 2013 A BAND OF STUBBORN MID LEVEL CLOUDS REMAINS ACROSS NORTHEAST MINNESOTA INTO WISCONSIN THIS MORNING. THE BAND IS SHOWING VERY LITTLE MOVEMENT AS HIGH PRESSURE EVER SO SLOWLY BUILDS IN FROM THE WEST. THE 27.06Z NAM AND 27.09Z RAP BOTH SHOW THIS MOISTURE REMAINING IN PLACE TODAY AS IT SLOWLY CONTRACTS ON THE WEST AND EAST SIDES. THIS SHOULD KEEP KRST OUT OF THE CLOUDS WITH CLEAR SKIES BUT EXPECTING THE CLOUDS TO HOLD ON THROUGH LATE AFTERNOON AT KLSE WITH VFR CEILINGS. ONCE THE CLOUDS CLEAR OUT...EXPECTING EITHER JUST SOME SCATTERED MID LEVEL CLOUDS OR CLEAR SKIES FOR THE OVERNIGHT HOURS AS A WEAK SHORT WAVE TROUGH PASSES OVERHEAD WITH THE AREA OF HIGH PRESSURE IN PLACE AT THE SURFACE. && .ARX WATCHES/WARNINGS/ADVISORIES... 332 AM CDT WED MAR 27 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...RRS LONG TERM....RRS AVIATION...04
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1233 AM CDT WED MAR 27 2013 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SYNOPSIS... ISSUED AT 229 PM CDT TUE MAR 26 2013 QUIET WEATHER WITH MODERATING TEMPERATURES THE REST OF THE WORK WEEK...SOME LIGHT PRECIPTIATION THIS WEEKEND...THEN PROBABLY COLDER AGAIN NEXT WEEK. THE BLOCKING ACRS THE CONUS WL EASE DURING THE PERIOD...WITH LOW AMPLITUDE WNWLY UPR FLOW BECOMING RE-ESTABLISHED. BUT THE FLOW AT HIGHER LATITUDES WL REMAIN BLOCKY. THE BREAK DOWN OF THE MIDDLE LATITUDE BLOCKING WL ALLOW W TO E PROGRESSION OF WX SYSTEMS TO RESUME...AND TEMPERATURES TO MODERATE BACK TO NEAR OR EVEN A LITTLE ABOVE SEASONAL NORMALS. BUT IT WL BE TOUGH TO GET ANY PROLONGED SIGNIFICANT WARMING AS LONG AS HIGH LATITUDES ARE BLOCKED...AND ANOTHER SHOT OF CHILLY CANADIAN AIR IS LIKELY TO OVERSPREAD THE AREA EARLY NEXT WK. THE PATTERN LOOKS UNFAVORABLE FOR SIG PCPN. && .SHORT TERM...TONIGHT AND WEDNESDAY ISSUED AT 229 PM CDT TUE MAR 26 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SHORTWAVE ACTIVITY PROGRESSING SOUTH ACROSS MUCH OF CENTRAL AND SOUTHERN WISCONSIN. DEEP CYCLONIC FLOW AND COLD TEMPS ALOFT HAVE MAINTAINED A WIDESPREAD VFR CLOUD DECK FROM NORTHERN ILLINOIS/INDIANA TO WESTERN ONTARIO. FLURRY ACTIVITY MOVED OUT OF THE AREA FOR THE MOST PART BY LATE IN THE MORNING...BUT DIURNAL INSTABILITY GENERATED SCT SNOW SHOWERS EARLY THIS AFTERNOON ACROSS MUCH OF THE AREA. THINK MUCH OF THE SNOW SHOWERS WILL DISSIPATE WITH LOSS OF HEATING LATE THIS AFTERNOON OR EARLY THIS EVENING...BUT WILL KEEP A MENTION OF FLURRIES GOING THROUGH 01Z. DRIER AIR IS MOVING SE OVER EASTERN UPPER MICHIGAN AND LAKE SUPERIOR...AND IS APPROACHING NORTHERN LAKE MICHIGAN EARLY THIS AFTERNOON. BESIDES THE SNOW SHOWERS...CLOUD TRENDS ARE THE MAIN FORECAST CONCERN. TONIGHT...THE SHORTWAVE TROUGH WILL MOVE SOUTHEAST OVER THE SOUTH-CENTRAL GREAT LAKES TOWARDS THE OHIO VALLEY. CHALLENGING CLOUD FORECAST TONIGHT...WHICH WILL IMPACT TEMPS. MID-LEVEL HEIGHT RISES WILL ONLY BE MODEST THIS EVENING...SO NOT ANTICIPATING A FAST CLEARING TREND. ADVECTION OF DRIER AIR FROM THE NORTHEAST AND ALSO FROM HIGH PRESSURE OVER THE NORTHERN PLAINS WILL CAUSE THE MID-LEVEL MOISTURE RIBBON TO BECOME STRETCHED ACROSS NORTHEAST WISCONSIN TONIGHT. AS A RESULT...THINK CLOUDS SHOULD THIN AS HOLES DEVELOP THROUGH THE NIGHT. CLOUDS TO HANG A BIT LONGER OVER N-C WISCONSIN WHERE FLOW REMAINS OFF LAKE SUPERIOR. IN THE END...MOSTLY CLOUDY THIS EVENING TO BECOME PARTLY CLOUDY OVERNIGHT. IF SKY CLEARS OUT QUICKER...TEMPS WILL FALL LOWER THAN CURRENTLY PLANNED. WILL GO WITH LOWS IN THE MID TEENS OVER THE COLD SPOT OF CENTRAL WISCONSIN...TO THE MID 20S NEAR LAKE MICHIGAN. WEDNESDAY...WILL STILL HAVE CYCLONIC FLOW THROUGH THE COLUMN TOMORROW...ALONG WITH AMPLE LOW LEVEL MOISTURE. AS LOW LEVEL LAPSE RATES STEEPEN WITH MORE IN THE WAY OF SUNSHINE...SHOULD SEE LINGERING CLOUD COVER BECOME ENHANCED THROUGH DIURNAL TEMPS RISES BY LATE MORNING TO EARLY AFTERNOON. TEMPS ALOFT WILL BE SIMILAR TO TODAY...BUT SHOULD SEE MORE SUNSHINE...SO WILL GO WITH TEMPS MAYBE A DEGREE WARMER THAN TODAY. .LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY ISSUED AT 229 PM CDT TUE MAR 26 2013 QUIET FOR THE REST OF THE WORK WEEK AS HIGH PRESSURE RIDGING SWD FM CANADA CONTROLS THE WX ACRS THE AREA. MODERATION OF THE AIR MASS SHOULD YIELD A LITTLE WARMING EACH DAY...ESP ONCE LOW-LEVELS DRY OUT A BIT MORE AND THERE ARE FEWER CLDS. STILL LOOKS LIKE THERE IS A CHC FOR PCPN WITH SHRTWV CROSSING THE AREA THIS WEEKEND. LATER SAT AND SAT NGT SEEM TO BE MOST FAVORED TIME PERIOD. BUT WITH LIMITED MOISTURE AND MODEST FORCING AT BEST...PCPN AMNTS WL BE LIGHT AND SOME AREAS MAY MISS OUT ON THE PCPN COMPLETELY. UPR VORTEX DIGGING ESE THROUGH THE LAKE SUPERIOR RGN COULD BRING ANOTHER BATCH OF LGT PCPN LATE IN THE WEEKEND OR EARLY NEXT WK. BUT IT/S MAIN INFLUENCE WL BE TO USHER ANOTHER COLD AIR MASS INTO THE AREA. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1229 AM CDT WED MAR 27 2013 CLEARING SKIES HAVE WORKED THEIR WAY INTO NE WI...BUT OVERCAST CONDITIONS PREVAILED ELSEWHERE. CIGS WERE VFR...WITH BASES MAINLY 5-7K FT. CLEARING SHOULD SPREAD INTO EC WI...BUT CLOUDS WILL LIKELY HOLD IN ACROSS NC/C WI UNTIL WEDS NGT...WHEN HIGH PRESSURE WILL BUILD INTO WSTRN WI. && .HYDROLOGY... ISSUED AT 229 PM CDT TUE MAR 26 2013 CONDITIONS FOR A FAST SNOWMELT NOT ON THE RADAR FOR MOST OF THE WORK WEEK...WITH CONTINUED DRY WEATHER AND COOL TEMPERATURES PERSISTING. HOWEVER...THERE STILL WILL BE A GRADUAL EROSION OF THE SNOWPACK WITH TEMPERATURES CLIMBING ABOVE THE FREEZING MARK EACH DAY. RUNOFF POTENTIAL FROM SNOW MELT INCREASES FOR NEXT WEEKEND WITH FORECAST TEMPERATURES CLIMBING TO THE LOWER TO MIDDLE 40S ON FRIDAY/SATURDAY/SUNDAY. OVERNIGHT LOW TEMPERATURES SATURDAY NIGHT ONLY FALL TO THE FREEZING MARK OVER EAST CENTRAL WISCONSIN AHEAD OF A WEAK COOL FRONT TO KEEP THE SNOWMELT PARTIALLY GOING. WITH THIS SCENARIO...THE MAIN AFFECTS OF RUNOFF COULD PRODUCE SOME PONDING OF WATER...AND A RISE IN THE RIVERS OVER CENTRAL AND EAST CENTRAL WISCONSIN LATE NEXT WEEKEND. RAIN OR MIXED PCPN MAY ALSO OCCUR THIS WEEKEND WITH THE FRONT...BUT PCPN AMOUNTS LOOK LIKE THEY WILL BE FAIRLY LIGHT AT THIS TIME. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....MPC LONG TERM......SKOWRONSKI AVIATION.......KIECKBUSCH HYDROLOGY......MPC
AREA FORECAST DISCUSSION...CORRECTED
NWS TAMPA BAY RUSKIN FL
320 AM EDT FRI MAR 29 2013 .SYNOPSIS... 07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A GENERALLY BENIGN UPPER LEVEL PATTERN ACROSS THE CONUS THIS MORNING. NORTHERN STREAM FLOW FORMS A BROAD LONGWAVE RIDGE OVER THE INTER-MOUNTAIN WEST AND CENTRAL PLAINS BEFORE SLIPPING BACK TO THE SOUTHEAST INTO A BROAD TROUGH NOW EXITING INTO THE WESTERN ATLANTIC. 29/00Z KTBW SOUNDING PROFILE CONTINUED TO SHOW A DRY COLUMN THROUGH THE EXTENT OF THE TROP WITH A PW VALUE OF ONLY AROUND 0.3". WITH LITTLE MOISTURE AND ESSENTIALLY NO SYNOPTIC SUPPORT FOR LIFT...SKIES ARE MOSTLY CLEAR OVER THE REGION THIS MORNING. AT THE SURFACE...HIGH PRESSURE IS RIDGING DOWN OVER THE PENINSULA FROM THE SOUTHERN/CENTRAL APPALACHIANS. ONCE AGAIN THE LIGHT GRADIENT...AND DRY ATMOSPHERE ARE ALLOWING TEMPERATURES TO BECOME QUITE COOL FOR LATE MARCH DUE TO THE GOOD RADIATIONAL COOLING SETUP. DUE TO CURRENTLY SLIGHTLY HIGHER DEWPOINTS COMPARED TO PREVIOUS NIGHTS...NOT ANTICIPATING LOW TEMPERATURES TO DROP DOWN AS LOW AS WAS SEEN THE PAST COUPLE NIGHTS. HOWEVER...A FEW NORMALLY COLDER LOCATIONS OVER THE INTERIOR NATURE COAST AND ALSO DOWN ACROSS DE SOTO...HARDEE... AND HIGHLANDS COUNTIES MAY BRIEFLY DIP INTO THE MIDDLE 30S TOWARD SUNRISE WITH A THREAT FOR SOME PATCHY FROST. && .SHORT TERM (TODAY THROUGH SUNDAY)... TODAY/TONIGHT...A PLEASANT AND QUIET DAY ON TAP IN TERMS OF SENSIBLE WEATHER. SURFACE HIGH PRESSURE WILL HOLD IN CONTROL OF THE REGION UNDER A DEEP LAYER WEST TO NORTHWEST FLOW REGIME. THE LIGHT GRADIENT WILL NOT BE IDEAL FOR MIXING...HOWEVER ABUNDANT SUNSHINE WOULD HELP TEMPERATURES RISE INTO THE LOW/MID 70S NORTH OF I-4 AND MID/UPPER 70S SOUTH. SHOULD SEE JUST ENOUGH TERRESTRIAL WARMING TO FORCE A FEEBLE SEA-BREEZE NEAR THE COAST THIS AFTERNOON...WHICH WILL HELP KEEP THINGS A BIT COOLER AT THE BEACHES. LOW TEMPERATURES TONIGHT WILL CONTINUE THE SLOW WARMING TREND...BUT STILL BE QUITE A BIT BELOW AVERAGE FOR MANY LOCATIONS. LOOKS AS THROUGH TEMPS WILL STAY WARM ENOUGH TO PREVENT ANY FROST CONCERNS...WITH THE COLDEST SPOTS ACROSS THE NATURE COAST AND INTERIOR CENTRAL COUNTIES DROPPING DOWN TO AROUND 40. ELSEWHERE WIDESPREAD MID/UPPER 40S LOOK COMMON AWAY FROM THE WARMER SUNCOAST BEACHES. SATURDAY/SATURDAY NIGHT...THE WARMING TREND CONTINUES! SURFACE HIGH PRESSURE WILL SLIP OFF THE SE CONUS COAST...BUT CONTINUE TO RIDGE BACK ACROSS THE CENTRAL FL PENINSULA. SLIGHTLY BETTER MIXING AND MODIFIED LOW LEVEL AIRMASS SHOULD ALLOW AFTERNOON TEMPS TO REACH WELL UP INTO THE 70S NORTH AND INTO THE LOWER 80S SOUTH AWAY FROM THE BEACHES. THE BETTER WARMING SHOULD CERTAINLY HELP TO FORCE SEA-BREEZE CIRCULATIONS SATURDAY AFTERNOON AND KEEP THE BEACHES COOLER. THE SEA-BREEZES WILL HAVE MORE POTENTIAL TO MOVE INLAND NORTH OF TAMPA BAY WHERE THE GRADIENT FLOW ON THE NORTH SIDE OF THE RIDGE AXIS WILL AID IN THE EASTWARD EXPANSION OF THE CIRCULATION. THE COOLEST SHELF WATERS ARE STILL FOUND OFF THE NATURE COAST...AND WITH THIS IN MIND...HAVE TEMPERATURES DROPPING BACK DOWN TOWARD THE UPPER 60S/LOW 70S NEAR THE COAST TO THE NORTH OF TAMPA BAY DURING THE SECOND HALF OF THE AFTERNOON. PLENTY OF SUNSHINE IS LIKELY TO START THE DAY...HOWEVER DURING THE MIDDLE TO LATER PORTION OF THE AFTERNOON WOULD EXPECT A SLOW INCREASE IN MID/HIGH LEVEL CLOUDS TO FILTER THE SUN IN RESPONSE TO THE APPROACH OF A WEAK IMPULSE. SATURDAY NIGHT LOOKS TO BE DRY AND SEASONABLY COOL. COLDEST SPOTS WILL ONLY DROP INTO THE UPPER 40S WITH MOST LOCATIONS STAYING ABOVE 50. THESE NUMBERS ARE CLOSE TO THE MOS CONSENSUS...HOWEVER COULD SEE LOW TEMPS BEING EVEN WARMER...ESPECIALLY ACROSS THE NATURE COAST. LATEST GFS/NAM CROSS SECTIONS BOTH SHOWING A BRIEF BY DECENT SWATH OF MID/HIGH LEVEL MOISTURE AND SYNOPTIC LIFT ASSOCIATED WITH THE PASSAGE OF THE PRE-MENTIONED IMPULSE. ALL THE DYNAMICS AND MOISTURE ARE PRETTY HIGH...SO NOT ANTICIPATING ANY PRECIP POTENTIAL. HOWEVER...IF SKIES DO END UP MOSTLY CLOUDY...THEN TEMPS SHOULD HAVE A MORE DIFFICULT TIME FALLING FOR THE MAJORITY OF THE NIGHT. SUNDAY...INITIAL IMPULSE QUICKLY PULLS EAST OF THE AREA DURING THE MORNING. LOOKING WELL TO OUR NORTH...AN AMPLIFYING UPPER TROUGH WILL HELP PUSH A WEAK COLD FRONT INTO THE SOUTHEASTERN CONUS DURING THE DAY. THIS FRONT LOOKS TO STALL NORTH OF I-10 AND NEVER GET DOWN THIS FAR DURING THE UPCOMING WEEKEND. NOT OUT OF THE QUESTION TO SEE A BRIEF SHOWER OR TWO ACROSS LEVY/CITRUS COUNTIES ON SUNDAY... HOWEVER THE BETTER LOW LEVEL FOCUS FOR LIFT ASSOCIATED WITH THE FRONT IS CURRENTLY PROGGED TO STAY NORTH OF OUR ZONES. OF NOTE...THE CONVECTIVE PARAMETRIZATION SCHEMES FROM THE GFS AND SOME SREF MEMBERS ARE KICKING OFF OVER THE PENINSULA (SOUTH OF I-4) DURING SUNDAY AFTERNOON. AGAIN...NOT OUT OF THE QUESTION TO SEE A BRIEF SHOWER...HOWEVER...SURFACE DEWPOINTS IN THE 50S ARGUE AGAINST ANY INSTABILITY THAT WOULD CURRENTLY WARRANT SHOWER MENTION IN THE FORECAST. WILL KEEP POPS AT SILENT 10%. TEMPERATURES WILL CONTINUE TO CLIMB ANOTHER COUPLE OF DEGREES FROM HIGHS ON SATURDAY. && .LONG TERM (SUNDAY NIGHT THROUGH NEXT THURSDAY)... HE PERIOD BEGINS WITH AN UPPER TROUGH JUST NORTH OF THE UPPER GREAT LAKES WITH NEARLY ZONAL FLOW ALOFT THE GULF REGION...A FRONTAL BOUNDARY STRETCHED ALONG THE GULF COAST/SE STATES...AND ATLANTIC HIGH PRESSURE RIDGING WEST ACROSS FL TO THE GULF. THROUGH ABOUT MID-WEEK THE UPPER TROUGH SAGS SOUTHWARD SOME AS IT TRACKS ALONG THE GREAT LAKES...WITH THE FRONTAL BOUNDARY SHIFTING INTO NORTHERN GULF WATERS AND THE NORTHERN HALF OF FL AS THE SURFACE RIDGE MOVES EAST AND SOUTH. BY MID-WEEK THE UPPER TROUGH LIFTS NORTHEAST AS A SHORT WAVE TROUGH MOVES FROM THE ROCKIES INTO THE SOUTHERN PLAINS THEN EAST TO THE CENTRAL GULF COAST. THIS FORMS A SURFACE TROUGH/LOW INITIALLY OVER THE WEST OR SOUTHWEST GULF THAT MOVES UP TO THE NORTH-CENTRAL OR NORTHEAST GULF BY THE END OF THE PERIOD...WITH THE BOUNDARY ACROSS THE STATE MOVING NORTH AS A WARM FRONT. A SLIGHT CHANCE OF SHOWERS WILL ONLY REACH THE NORTHERN CWA MON AND TUE BUT THEN SPREAD SOUTHWARD ACROSS THE REST OF THE CWA WED AND THU...INCREASING TO LOW END CHANCE. TEMPERATURES WILL RUN ABOVE NORMAL ALTHOUGH THEY WILL DECREASE SLIGHTLY AFTER MID-WEEK DUE TO AN INCREASE IN CLOUDS AND RAIN CHANCES. && .AVIATION... VFR FOR THE NEXT 24 HOURS. LIGHT VARIABLE WINDS OVERNIGHT INCREASE AND BECOME NE OR EAST IN THE MORNING THEN SHIFT TO NORTH OR NW IN THE AFTERNOON. && .MARINE... HIGH PRESSURE WILL REMAIN IN CONTROL OF THE EASTERN GULF THROUGH THE UPCOMING WEEKEND. WINDS AND SEAS ARE FORECAST TO REMAIN BELOW HEADLINE CRITERIA WITH WINDS BECOME VARIABLE NEAR THE COAST EACH AFTERNOON WITH THE DEVELOPMENT OF SEA-BREEZE CIRCULATIONS. A WEAK FRONT WILL SETTLE INTO THE NORTHERN GULF AROUND TUESDAY OF NEXT WEEK FOLLOWED BY WHAT LOOKS TO BE A PERIOD OF INCLEMENT WEATHER FOR THE MIDDLE AND END OF THE WEEK. && .FIRE WEATHER... HIGH PRESSURE WILL REMAIN IN CONTROL OF THE REGION THE NEXT COUPLE OF DAYS PROVIDING DRY CONDITIONS. WIDESPREAD DURATIONS OF CRITICALLY LOW RELATIVE HUMIDITY ARE EXPECTED TODAY WITH MINIMUM VALUES DROPPING INTO THE LOWER 20S FOR MANY LOCATIONS. RED FLAG WARNINGS REMAIN IN EFFECT FOR PINELLAS...HIGHLANDS...POLK...SARASOTA...AND LEE COUNTIES WHERE FORECASTED ERC VALUES ARE AT OR GREATER THAN 37. ANOTHER DAY WITH WIDESPREAD CRITICALLY LOW RELATIVE HUMIDITY VALUES EXPECTED FOR SATURDAY...HOWEVER THE MINIMUM VALUES SHOULD BE IN THE MIDDLE AND UPPER 20S. A FIRE WEATHER WATCH HAS BEEN ISSUED FOR POLK...HIGHLANDS...SARASOTA...AND LEE COUNTIES. PINELLAS AS BEEN LEFT OUT OF THE WATCH AS CRITICAL DURATIONS OF LOW RELATIVE HUMIDITY ARE NOT CURRENTLY EXPECTED ALONG THE COAST. && .PRELIMINARY POINT TEMPS/POPS... TPA 73 53 75 60 / 0 0 0 10 FMY 79 54 81 59 / 0 0 0 10 GIF 76 48 80 55 / 0 0 0 10 SRQ 73 51 75 57 / 0 0 0 10 BKV 75 42 78 49 / 0 0 0 10 SPG 73 59 76 62 / 0 0 0 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...RED FLAG WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR HIGHLANDS-LEE-PINELLAS-POLK-SARASOTA. FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR HIGHLANDS-LEE-POLK-SARASOTA. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA LONG TERM/AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
525 AM EDT FRI MAR 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 523 AM EDT FRI MAR 29 2013 WEAK SHORT WAVE AND ASSOCIATED JET STREAK MOVING ACROSS THE GREAT LAKES THIS MORNING. COUPLED WITH WEAK MID LEVEL THETA E ADVECTION THESE FEATURES HAVE HELPED GENERATE AN AREA OF MID LEVEL CLOUDS THIS MORNING JUST TO OUR WEST. RAP13 SEEMS TO HAVE BEST HANDLE ON THIS MOISTURE WITH ITS 850-700MB LAYER RH. HRRR IS TRYING TO CATCH UP BUT STILL DOES NOT APPEAR TO HAVE THE SCOPE SEEN ON SATELLITE. SPECTRAL MODELS GENERALLY CLUELESS. SHORT WAVE WILL PASS THROUGH OUR AREA DURING EARLY TO MID MORNING HOURS. RAP13 MOVES HIGHER RH VALUES ACROSS WESTERN HALF OF OUR AREA THIS MORNING AND GRADUALLY SINKS THIS AREA SOUTH WHILE MIXING ALSO HELPS TO ERODE CLOUDS. HAVE INCREASED CLOUD COVER THIS MORNING SUBSTANTIALLY ACROSS WESTERN AREAS USING SATELLITE TRENDS AND RAP AS GUIDANCE. GRADUALLY DECREASED AMOUNT OF SKY COVER BY EARLY AFTERNOON SO SHOULD SEE A PARTLY TO MOSTLY CLOUDY MORNING TRANSITIONING TO MOSTLY SUNNY THIS AFTERNOON. EASTERN AREAS TO REMAIN FAR ENOUGH REMOVED PER TRAJECTORIES TO KEEP MOSTLY SUNNY THROUGH THE DAY. RESULT OF THIS MAY HELP KEEP TEMPS DOWN A FEW DEGREES WEST BUT EXPECT RAPID INCREASE ONCE CLOUDS DEPART. OTHERWISE TEMPS WILL BE A FEW DEGREES WARMER THAN THURSDAY OUTSIDE OF CLOUDS. WARMER TEMPS ON SATURDAY AHEAD OF NEXT SHORT WAVE WITH HIGHS NEARING 60. INCREASING HIGH CLOUDS IN AFTERNOON MAY SLOW WARMING BUT IF SKIES REMAIN CLEAR WOULD EXPECT SOME AREAS INTO 60S GIVEN MOS COOL BIAS YESTERDAY WITH FULL SUN. STRONG THETA E SURGE WITH MID LEVEL TROUGH APPROACHING SAT NIGHT SHOULD LEAD TO RAIN SHOWERS. MODELS CONTINUE TO TREND FASTER WITH NAM12 SHOWING PCPN DURING FIRST HALF OF NIGHT. USED COMPROMISE OF SOLUTIONS FOR TIMING BUT LOOKS LIKE ALL AREAS WILL RECEIVE A NICE RAINFALL OF ONE QUARTER TO ONE HALF INCH. ELEVATED THUNDER STILL NOT OUT OF QUESTION BUT REMAINS LOW PROB EVENT SO NO INCLUSION JUST YET. IF WE CAN GET SOME LIGHTNING WITH THIS RAIN RAPID GREEN UP WOULD BE EXPECTED IN WAKE OF RAIN. && .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 523 AM EDT FRI MAR 29 2013 SUNDAY THROUGH THURSDAY...A WEAK UPPER LEVEL TROF WILL BE MOVING ACROSS THE AREA SUNDAY...FOLLOWED BY A COLD FRONT SUNDAY NIGHT. THERMAL PROFILES SUNDAY ARE BORDERLINE BETWEEN RAIN AND A RAIN/SNOW MIX SUNDAY MORNING OVER NORTHERN AREAS...ESPECIALLY THE GFS. FOR NOW LEFT JUST RAIN IN THE FCST GIVEN SFC TEMPERATURES MAINLY IN THE 40S AND NAM 1000/850 MB THICKNESSES ALMOST EXCLUSIVELY ABOVE 1300 METERS. VERY CHILLY AIR WILL ONCE AGAIN SPREAD ACROSS THE AREA SUNDAY NIGHT AND MONDAY. DELTA T VALUES SUPPORT SOME LAKE EFFECT SNOW SHOWERS...HOWEVER...VERY LITTLE PRECONDITIONING IS EXPECTED. A 300 TO 310 FETCH WITH UPSTREAM DEW PTS IN THE SINGLE DIGITS MAY NOT ALLOW MUCH MORE THAN LAKE EFFECT CLOUDS. OTHERWISE...ATTEMPTED TO TREND TEMPERATURES DOWN MONDAY NIGHT THROUGH WEDNESDAY IN LINE WITH THE GFS MEX MOS. 850 MB TEMPS TUESDAY MORNING NEAR -14C TUESDAY WILL HELP KEEP HIGHS IN THE 30S...ESPECIALLY NEAR THE LAKE WITH LAKE ENHANCED CLOUDS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY) ISSUED AT 123 AM EDT FRI MAR 29 2013 VFR CONDITIONS EXPECTED AT TAF SITES BUT SATELLITE SHOWS A LARGE AREA OF MID LEVEL CLOUDS ACROSS IL ASSOCIATED WITH WEAK SHORT WAVE AND MID LEVEL MOISTURE ADVECTION. RUC13 AND HRRR TO SOME EXTENT ONLY MODELS PICKING UP ON THESE CLOUDS WITH RUC13 850-700MB RH FIELDS HANDLING IT THE BEST. THIS GUIDANCE AND SATELLITE LOOPS SUPPPORT A SOUTHEAST MOVEMENT AND EXPECT THESE CLOUDS INTO KSBN IN NEXT FEW HOURS AND KFWA TOWARD DAYBREAK. SOUNDINGS AND CROSS SECTIONS SUGGEST CLOUDS TO LINGER THROUGH MID TO LATE MORNING BEFORE MIXING AND MOVING SOUTH. OTHERWISE LIGHT AND VARIABLE WINDS GENERALLY UNDER 10 KNOTS THROUGH THE PERIOD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
141 AM EDT FRI MAR 29 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 327 PM EDT THU MAR 28 2013 NO SENSIBLE WEATHER CONCERNS THROUGH THE PERIOD WITH SFC RIDGE AXIS...CURRENTLY LOCATED FROM THE ARROWHEAD OF MN INTO CENTRAL TENNESSEE...SET TO DRIFT SLOWLY EAST. EVEN ON THE "COLD" SIDE OF THE RIDGE...TEMPS HAVE REBOUNDED NICELY WITH MOST LOCATIONS IN THE MID 40S. SNOW PACK STILL EXISTS IN THE FAR SOUTHERN COUNTIES...HAMPERING THE WARM UP SLIGHTLY. HOWEVER...INCREASING LATE MARCH SUN ANGLE HELPING OFFSET THE USUAL COLD CONTRIBUTION WITH MOST SITES NOW PUSHING 40 AND SNOW PACK DWINDLING EACH HOUR. GENERALLY CLEAR SKIES WILL PREVAIL WITH OVERNIGHT LOWS VERY SIMILAR TO LAST NIGHT IN THE MID TO UPPER 20S. TEMPS WILL REBOUND ONCE AGAIN ON FRIDAY...WITH SOUNDING INDICATE MIXING THROUGH TO AT LEAST 900 MB. AFTERNOON HIGHS WILL BE AT LEAST AS HIGH...IF NOT A FEW DEGREES WARMER FRI AFTERNOON WITH MOST LOCATIONS IN THE UPR 40S TO AROUND 50. && .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 327 PM EDT THU MAR 28 2013 UPR LOW OVER NW TERRITORIES THIS AFTN WILL STRENGTHEN AND DIG SE TO ONTARIO OVER THE WEEKEND AS JET STREAK OVER THE GULF OF ALASKA PROPAGATES EAST INTO BASE OF THE TROF. LEAD SHRTWV TO S-SE OF UPR LOW WILL MOVE ACROSS THE GRTLKS SAT NGT/SUNDAY. LOW LEVEL WAA AND LINGERING DRY AIRMASS SHOULD ALLOW FOR ABOVE NORMAL TEMPS AHEAD OF THIS SYSTEM SAT. NAM APPEARS TO BE SUFFERING FROM LOW LEVEL COOL BIAS LATELY THUS LEANED TOWARD WARMER GFS/MAV GUIDANCE FOR HIGHS SAT FCST IN THE M-U50S. STRONG/DEEP UVM... LOW LEVEL THETA-E ADVECTION... AND WK INSTABILITY EXPECTED TO ACCOMPANY SHRTWV/CDFNT SAT NGT AS IT MOVES INTO THE CWA... THUS TRENDED POPS/QPF UP FOR THIS PERIOD... SOME POTENTIAL FOR ELEVATED TSTMS REACHING AS FAR NORTH AS OUR CWA... BUT HELD OFF ADDING TO FCST ATTM. FRONTAL BOUNDARY MOVG THROUGH ERN PORTION OF THE CWA SUNDAY MORNING WILL LIKELY RESULT IN SHOWERS CONTG THERE... WITH JUST A CHC FARTHER WEST. SHOULD BE A LITTLE COOLER SUNDAY BUT MAIN BLAST OF COLD AIR EXPECTED TO MOVE INTO THE AREA SUNDAY NIGHT. ALONG WITH THE SECONDARY CDFNT... SERIES OF MID LEVEL SHRTWV`S ROTATING AROUND ONTARIO LOW WILL MOVE THROUGH THE GRTLKS SUNDAY NIGHT/MONDAY...PSBLY ACCOMPANIED BY RAIN/SNOW SHOWERS. STRONG CANADIAN SFC HIGH EXPECTED TO MOVE SE ACROSS THE PLAINS AND INTO GRTLKS/OH VALLEY TUE-WED RESULTING IN DRY PERIOD. UNSEASONABLY COLD CONDITIONS EXPECTED WITH HIGHS 35-40 MON-TUE. TEMPS SHOULD WARM INTO THE 40S WED AS AIRMASS MODIFIES AND BACK TO NEAR NORMAL BY THU AS WAA ON BACKSIDE OF THE RIDGE AND AHEAD OF A WK CDFNT OVERSPREADS THE CWA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 134 AM EDT FRI MAR 29 2013 VFR CONDITIONS EXPECTED AT TAF SITES BUT SATELLITE SHOWS A LARGE AREA OF MID LEVEL CLOUDS ACROSS IL ASSOCIATED WITH WEAK SHORT WAVE AND MID LEVEL MOISTURE ADVECTION. RUC13 AND HRRR TO SOME EXTENT ONLY MODELS PICKING UP ON THESE CLOUDS WITH RUC13 850-700MB RH FIELDS HANDLING IT THE BEST. THIS GUIDANCE AND SATELLITE LOOPS SUPPPORT A SOUTHEAST MOVEMENT AND EXPECT THESE CLOUDS INTO KSBN IN NEXT FEW HOURS AND KFWA TOWARD DAYBREAK. SOUNDINGS AND CROSS SECTIONS SUGGEST CLOUDS TO LINGER THROUGH MID TO LATE MORNING BEFORE MIXING AND MOVING SOUTH. OTHERWISE LIGHT AND VARIABLE WINDS GENERALLY UNDER 10 KNOTS THROUGH THE PERIOD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...FISHER LONG TERM...JT AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
317 AM EDT FRI MAR 29 2013 .Short Term (Now - Saturday)... Issued at 300 AM EDT Fri Mar 29 2013 An upper level shortwave and weak sfc boundary were located to our WSW early this morning producing showers and t-storms from eastern KS to western KY. The latest RAP model guidance seems to be handling this area of precip quite well, so have relied on it for short term POPs. Rain showers look likely across portions of south central KY this morning before moving south of the area into TN this afternoon. Think that better lapse rates out west are producing the t-storms with this wave and do not anticipate those better lapse rates to translate eastward so will not include thunder in this forecast. For high temperatures today, have gone with mid 50s over southern Indiana and north central KY which will see less cloud cover overall and no precip. Lower 50s can be expected for highs over south central KY where rain is anticipated. Tonight sfc high pressure will quickly work in from the north allowing for dry conditions and only partly cloudy skies across southern IN and northern KY. Went with a decent temp gradient due to cloud cover with low to mid 30s for lows over southern IN/northern KY to upper 30s and lower 40s over south central KY. The next push of moisture doesn`t look to arrive until late Sat afternoon or evening as a warm front pushes into south central KY. Therefore, limited POP chances to just the afternoon hours over south central KY for Sat. The rest of the area should be dry and warm up quite nicely. With only partly cloudy skies anticipated during the morning and early afternoon, went with high temps in the low to mid 60s. .Long Term (Saturday Night - Thursday)... Issued at 300 AM EDT Fri Mar 29 2013 Cold front number one will be fast approaching from the northwest Saturday night. Rain and a few embedded rumbles of thunder will overspread the forecast area Saturday night and through the morning hours Sunday. Rain chances will diminish from west to east late Sunday morning, with a dry period anticipated from roughly Sunday afternoon through Sunday night. A second cold front will quickly enter the forecast area from the north Monday and sag south through Monday night. Expect rain chances to increase through the day Monday and rain should exit the southern CWA by Tuesday morning. Temperatures will fall behind the front Monday night and soundings indicate the potential for some smaller ice crystal growth. It appears the loss of moisture/ice crystals within the dendritic growth layer will limit large snowflake generation. So, there could be some light snow mixed with the rain overnight as the system exits. Then, high pressure will build across the Ohio Valley, with the active storm track being pushed well to our south. The only question is whether a southern track system Thursday will be deep enough to increase moisture and rain potential across the Ohio and Tennessee Valleys as it tracks across the Gulf States. Rain probabilities are low for Thursday, with an overall slower trend noted in latest guidance. Will go with a dry forecast Tuesday through Thursday, with perhaps a slight rain chance across our south and southeast CWA just beyond the long-term period. The cold front that swings through the area early Sunday will not be followed by a cold air mass. Still expect temperatures in the 60s Sunday afternoon. However, the passage of the second front on Monday will bring a return to unseasonably cool conditions through Thursday. The good news is temperatures appear to moderate some through the work week. So, while highs in the 40s are expected Tuesday, highs Thursday appear to reach the middle 50s. && .Aviation (06Z TAF Issuance)... Issued at 105 AM EDT Fri Mar 29 2013 VFR conditions are expected for this TAF period. Mid and upper level clouds will continue to stream into the area overnight and continue through the day as an upper level shortwave passes through south central KY. This wave looks to bring precip in the form of rain showers to BWG today. These showers have made it as far east as western KY and a few will likely make it into the BWG TAF within the next 1-3 hrs. The main push of moisture should hold off until later this morning with light steady rain showers expected from roughly 13Z-20Z. SDF/LEX still look to remain dry. The 0Z NAM indicates MVFR conditions will develop at BWG today, but feel it is an outlier at this point compared to other model runs and upstream obs. Still will need to watch BWG for some cig/vsby restrictions today. Winds will be hard to pin down throughout the TAF period. Generally they will remain light (under 5 kts). Variable winds can be expected during the early morning hours and again this evening. Think that the predominant wind direction at BWG this afternoon will be SSE with SDF/LEX winds predominantly SSW. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. $$ Short Term.......AMS Long Term........MJP Aviation.........AMS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
340 AM CDT FRI MAR 29 2013 .SHORT TERM...TODAY THROUGH SATURDAY NIGHT. THE MAIN FORECAST CONCERNS IN THIS PERIOD ARE CHANCES FOR SHOWERS/ THUNDERSTORMS AND TEMPERATURES. TEMPERATURES YESTERDAY TOPPED OUT MAINLY IN THE UPPER 50S AND LOWER 60S ACROSS THE FORECAST AREA. HIGHS TODAY SHOULD BE ABOUT 3 TO 5 DEGREES WARMER...BASED ON A SMALL INCREASE IN 850 MB TEMPS. THERE IS SOME CONCERN THAT PCPN COULD DEVELOP LATE THIS AFTERNOON AS LOW LEVEL MOISTURE AND INSTABILITY INCREASE. BUT BASED ON MOST RECENT FORECASTS OF MOST UNSTABLE CAPE FORECASTS FROM RAP MODEL...KEPT THINGS DRY UNTIL THIS EVENING. 850 MB DEWPOINTS WERE IN THE 5 TO 10 DEGREE CELSIUS RANGE LAST EVENING ACROSS THE SOUTHERN PLAINS... MAINLY FROM OKLAHOMA SOUTH. MODEL SHOW MOISTURE INCREASING IN OUR AREA...BUT MAIN AXIS STAYS MAINLY TO OUR WEST IN CENTRAL NEBRASKA THROUGH 00Z THIS EVENING. THIS 850 MB MOISTURE SHOULD SPREAD OVER OUR AREA TONIGHT AND THEN OUT OF THE AREA SATURDAY. KEPT FAIRLY HIGH POPS GOING FOR TONIGHT AND SATURDAY MORNING. SOME OF THE MODEL QPFS LOOK A LITTLE HIGH...BUT CERTAINLY AMOUNTS BETWEEN A TENTH AND A QUARTER OF AN INCH SEEM REASONABLE...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. COMBINATION OF CLOUD COVER AND WIND SHOULD HELP KEEP LOWS TONIGHT IN THE 40S MOST SPOTS. ON SATURDAY...A WIND SHIFT WILL MOVE ACROSS THE AREA...BUT 850 MB TEMPERATURES DO NOT CHANGE MUCH AND MIXING SHOULD BE GOOD. STAYED FAIRLY CLOSE TO PREVIOUS FORECAST FOR HIGHS SATURDAY...RANGING FROM UPPER 50S NORTH TO MID OR UPPER 60S FAR SOUTH. IF CLOUDS AND PCPN CLEAR OUT FASTER THAN CURRENTLY EXPECTED...HIGHS COULD BE A LITTLE WARMER NORTHERN AND CENTRAL ZONES. SATURDAY NIGHT WE ARE BETWEEN SYSTEMS AND FOR NOW KEPT THINGS DRY. SOME SHOWERS COULD DEVELOP TO OUR WEST IN THE AFTERNOON BUT FOR NOW EXPECTED THESE TO DISSIPATE SATURDAY EVENING BEFORE REACHING SOUTHEAST NEBRASKA. LOWS WILL DROP INTO THE 30S SATURDAY NIGHT. MILLER .LONG TERM...SUNDAY THROUGH THURSDAY. MAIN CONCERNS IN THIS PERIOD ARE TEMPERATURES SUNDAY AND PCPN CHANCES FOR SUNDAY INTO SUNDAY NIGHT. A STRONG COLD FRONT WILL BE PUSHING INTO OUR NORTHERN ZONES SUNDAY AFTERNOON...SO JUST HOW WARM IT WILL GET IS PROBLEMATIC. AIRMASS WILL BE STARTING OUT QUITE MILD...BUT TEMPERATURES SHOULD BE FALLING IN THE AFTERNOON ACROSS NORTHEAST NEBRASKA AS WINDS SHIFT TO THE NORTH. WENT WITH HIGHS CLOSE TO NOON NORTH IN THE 50S...BUT IN THE 60S MID OR LATE AFTERNOON SOUTH. BUT AGAIN THIS WILL DEPEND ON FRONTAL TIMING. AREAS ALONG THE KANSAS BORDER COULD APPROACH 70...BUT DID NOT WANT TO GET TOO OPTIMISTIC AT THIS POINT. FAIRLY DECENT FORCING IS EXPECTED ALONG AND BEHIND THE FRONT...SO KEPT POPS 20 TO 30 PERCENT MOST AREAS SUNDAY AFTERNOON. PCPN TYPE WILL BE AN ISSUE AS THE COLD AIR POURS IN FOR SUNDAY NIGHT...WITH RAIN CHANGING TO SNOW. TRIED TO ADD SOME DETAIL TO PCPN TYPE SUNDAY NIGHT BUT THIS WILL BE REFINED AS WE GET CLOSER. DID NOT MENTION ANY SNOW ACCUMULATION AT THIS POINT...BUT THAT WILL NEED TO BE MONITORED CLOSELY. HIGHS MONDAY SHOULD ONLY REACH THE 30S...BUT THEN LOOK FOR MODERATING TEMPERATURES THROUGH THURSDAY AS MILDER AIR MOVES IN FROM THE SOUTH AND WEST. MILLER && .AVIATION... 06Z TAFS FOR KOMA...KLNK...KOFK. LIGHT FOG REMAINS A SMALL RISK AT TAF SITES LATE TONIGHT...BUT DWPTS HAVE REMAINED LOW ENOUGH SO THAT CHANCES APPEARED TOO SMALL TO INCLUDE IN 06Z TAFS. A DISTURBANCE TRACKING ACROSS THE DAKOTAS LATE FRIDAY WILL BRING INCREASING MID CLOUDS AND POSSIBLY MVFR CIGS TO TAF SITES FRIDAY NIGHT...ALONG WITH SCT SHOWERS/ THUNDERSTORMS. IT APPEARED MVFR OR LOWER CIGS...IF THEY OCCURRED... WOULD HOLD OFF UNTIL AFTER 30/06Z. SHOWERS COULD APPROACH KOFK VICINITY BEFORE 30/06Z AND A PROB30 GROUP WAS INCLUDED AT THAT SITE LAST 3 HRS OF TAF PERIOD. APPEARS SHOWER CHANCES AT KOMA AND KLNK WOULD BE MAINLY AFTER 30/06Z. CHERMOK && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
331 AM CDT FRI MAR 29 2013 .SHORT TERM...TODAY AND TONIGHT... ISSUED AT 330 AM CDT FRI MAR 29 2013 THE CHALLENGES OF THE SHORT TERM ARE HOW LONG THE ONGOING DENSE FOG WILL PERSIST...THE IMPACT OF THE FOG ON TEMPERATURES FOR TODAY AND THE POTENTIAL FOR ISOLATED THUNDERSTORMS ACROSS THE SOUTHWEST THIS AFTERNOON WITH A WINTRY MIX NORTH. THE RAP AND HRRR HAVE HAD A GOOD HANDLE ON THE EVOLUTION OF THE DENSE FOG ACROSS CENTRAL AND NORTHWEST NORTH DAKOTA THROUGH THE NIGHT...AND WILL FOLLOW THEIR VISIBILITY FORECASTS FROM THEIR LATEST RUN (29/04 UTC). THIS WOULD SUGGEST THAT DENSE FOG...ESPECIALLY OVER THE SNOWPACK MAY HOLD NEAR ONE QUARTER OF A MILE THROUGH 18 UTC. THIS IS SUPPORTED BY THE OBSERVED FOG TRENDS SEEN ON THURSDAY IN A SIMILAR ENVIRONMENT. THUS HAVE EXPANDED THE DENSE FOG ADVISORY THROUGH 18 UTC. WOULD NOT RULE OUT A POSSIBLE EXPANSION IN TIME FOR PORTIONS OF THE ADVISORY LATER INTO THE AFTERNOON AS MID LEVEL CLOUD COVER MAY SLOW DOWN THE BURNING OFF OF THE FOG. IN REGARDS TO TEMPERATURES...WILL USE THE OBSERVED TEMPERATURE PATTERN ON THURSDAY AS A GUIDE...AND WILL LIMIT HIGHS TO THE UPPER 20S ACROSS MUCH OF THE SNOWPACK IMPACTED BY FOG. LIKE THURSDAY...THE SNOW AND FOG FREE SOUTHWEST IS EXPECTED TO WARM INTO THE UPPER 50S TO THE LOWER 60S AS MIXING INCREASES BEHIND A WEAK TROUGH. STEEP LAPSE RATES THROUGH MUCH OF THE TROPOSPHERE SUGGESTS DIURNALLY DRIVEN SHOWER ACTIVITY IS POSSIBLE...WITH ISOLATED THUNDERSTORMS NOT OUT OF THE QUESTION GIVEN THE COOL TEMPERATURES ALOFT AND STEEP LAPSE RATES SUPPORTING AFTERNOON ML CAPE VALUES OF 200-400 J/KG. ELSEWHERE IN REGARDS TO PRECIPITATION TODAY...A WEAK WAVE ACROSS SOUTHWEST SASKATCHEWAN AS OF 08 UTC WILL PROPAGATE SOUTHEAST THROUGH THE DAY. GIVEN THE WEAK FORCING AND DRY LOW LEVELS...PRECIPITATION WITH SCATTERED ACTIVITY WILL BE LIGHT. HOWEVER...WITH A WARM LAYER ALOFT ABOVE THE SUB-FREEZING SURFACE TEMPERATURES OF THE SNOWPACK...FREEZING RAIN AND SLEET ARE POSSIBLE. FOR TONIGHT...BOUNDARY LAYER MIXING ON THE ORDER OF 10 KTS CWA WIDE IN THE WAKE OF THE AFOREMENTIONED SURFACE TROUGH SHOULD HELP TO KEEP TEMPERATURES FROM BOTTOMING OUT TOO FAR...WITH SOME STRATUS ALSO HINTED IN THE 00 UTC DETERMINISTIC GUIDANCE. THUS...FOLLOWED FAIRLY CLOSELY TO A BLEND OF THE 00 UTC DETERMINISTIC MODEL SUITE FOR LOWS TONIGHT. .LONG TERM...SATURDAY THROUGH NEXT FRIDAY... ISSUED AT 330 AM CDT FRI MAR 29 2013 WILL SEE AN ACTIVE FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND AS A CLOSED UPPER LOW MOVES SOUTH ACROSS CENTRAL CANADA ON SATURDAY AND INTO THE GREAT LAKES REGION SUNDAY AND MONDAY. CYCLONIC FLOW ALOFT WILL BRING SEVERAL EMBEDDED S/WVS ACROSS THE NORTHERN PLAINS SATURDAY THROUGH SUNDAY AFTERNOON SO WILL MAINTAIN PRECIP CHANCES. ONLY LIGHT QPF IS DEPICTED. THE UPPER LOW WILL ALSO BRING A SURGE OF COLDER AIR INTO THE NORTHERN PLAINS SUNDAY INTO MONDAY. TEMPERATURES MODERATE BACK TO NORMAL BY MID-WEEK AS THE COLDER AIR MOVES OFF TO OUR EAST. WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. OPTED TO KEEP THE FORECAST DRY. NEXT CHANCE OF PRECIPITATION ARRIVES AT THE END OF THE WORK WEEK WHEN THE UPPER JET PUSHES SOUTH TO ACROSS FAR SOUTHERN CANADA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 330 AM CDT FRI MAR 29 2013 VLIFR CONDITIONS IN FOG WILL CONTINUE AT KMOT AND KJMS THROUGH AT LEAST 18 UTC FRIDAY...WITH SLOW IMPROVEMENT THEREAFTER. VLIFR FOG AT KBIS SHOULD BURN OFF A BIT FASTER...IN THE 15-17 UTC TIMEFRAME WITH THE LACK OF A DEEP SNOWPACK. KISN AND KDIK HAVE REMAINED ON THE FRINGE OF THE FOG BANK THUS FAR TONIGHT...AND ARE EXPECTED TO THROUGH FRIDAY MORNING. THAT SAID...TEMPORARY REDUCTIONS TO IFR CANNOT BE RULED OUT. SCATTERED PRECIPITATION POSSIBLY IN THE FORM OF FREEZING RAIN OR SLEET MAY IMPACT KISN AND KMOT...AND POSSIBLY KJMS FRIDAY EVENING. SCATTERED SHOWERS WITH POSSIBLY AN ISOLATED THUNDERSTORM IS POSSIBLE NEAR KDIK FRIDAY AFTERNOON. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING FOR NDZ001>005-009>013-019>023-025-034>037-042-045>048-050-051. && $$ SHORT TERM/AVIATION...AYD LONG TERM...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1251 AM CDT FRI MAR 29 2013 .UPDATE... ISSUED AT 1240 AM CDT FRI MAR 29 2013 BASED UPON WEBCAMS AND SURFACE OBSERVATIONS THROUGH 0530 UTC...EXPANDED THE DENSE FOG ADVISORY INTO DICKEY...LAMOURE... MCINTOSH...MORTON...MERCER...GRANT...OLIVER AND SIOUX COUNTIES. THE HRRR THROUGH THE NIGHT HAS CONSISTENTLY BEEN HANDLING THE EVOLUTION OF THE FOG WELL...WHICH CONTINUES WITH ITS LATEST 02 UTC RUN. BASED ON THE HRRR...MAY HAVE TO EXTEND THE ADVISORY PAST 15 UTC...ESPECIALLY OVER THE SNOWPACK WITH THE NEXT UPDATE IF ITS FORECAST TRENDS CONTINUE. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 314 PM CDT THU MAR 28 2013 THE MAIN FORECAST CHALLENGE FOR THE SHORT TERM IS FOG TONIGHT AND MIXED PRECIPITATION FOR LATE TONIGHT AND FRIDAY. FOG HAD BEEN PROBLEMATIC TODAY AS THE CURRENT SNOW PACK MAINLY NORTH AND EAST OF THE MISSOURI RIVER WAS PROVIDING LOW LEVEL MOISTURE AND KEEPING THE SURFACE LAYER COOLER. ADDING TO THE COMPLEXITY WAS THE EAST/NORTH LIGHT WIND FLOW WHICH MOVES UP IN ELEVATION ALONG THE COTEAU OVER NORTHERN NORTH DAKOTA TO SOUTH AND WEST OF JAMESTOWN...COOLING JUST ENOUGH TO KEEP LOW CLOUDS AND FOG IN THE AREA. ONLY AROUND 1-2 PM CDT WAS SIGNIFICANT DISSIPATION OF THE FOG LAYER EVIDENT ON SATELLITE. SOME LINGERING PATCHY DENSE FOG CONTINUED AT MINOT TO HARVEY/CARRINGTON/RUGBY AT 2 PM. ABOVE THE SURFACE BOUNDARY LAYER THROUGH H850...SIGNIFICANT WARM ADVECTION WAS MOVING IN FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION. HAD EXPECTED THE FOG TO DISSIPATE EARLIER BASED ON THIS...BUT IT WAS DELAYED BY THE SNOW PACK AND COTEAU INFLUENCES MENTIONED ABOVE. AS THE FOG AND LOW CLOUDS DISSIPATE...THE WARM ADVECTION FROM ABOVE THE BOUNDARY LAYER SHOULD BECOME MORE WELL-ESTABLISHED WHICH SHOULD ACT TO KEEP FOG FROM RE-DEVELOPING. HOWEVER...WITH SUNSET APPROACHING TEMPERATURES WILL FALL AND THE THREAT FOR RE-DEVELOPMENT OF FOG OVER THE SNOW PACK RISES. THUS THE PROBLEM FOR TONIGHT IS WHERE/WHEN/HOW DENSE ANY FOG WILL RE-DEVELOP - IN OTHER WORDS WHICH FORCES WILL WIN OUT. THUS REGARDING FOG TONIGHT - HAVE A MENTION OF PATCHY/AREAS/WIDESPREAD FOG MAINLY OVER THE SNOW PACK THROUGH MID MORNING ON FRIDAY. NEXT ATTENTION TURNS TO THE UPPER LEVEL SHORTWAVE TO BRING SOME LIGHT PRECIPITATION TO THE AREA. LATEST SATELLITE IMAGERY INDICATES THE SHORTWAVE IS OVER SOUTHERN ALBERTA/SASKATCHEWAN. THIS SHORTWAVE IS PROGGED TO REACH WESTERN NORTH DAKOTA AROUND MIDNIGHT AND SPREAD EASTWARD ACROSS THE STATE ON FRIDAY. TEMPERATURE PROFILES FROM FORECAST SOUNDINGS INDICATE A STRONG WARM LAYER ALOFT AT H850 MENTIONED ABOVE. THESE FACTORS RESULT IN EXPECTED PRECIPITATION TO BE IN THE FORM OF FREEZING RAIN OR SLEET IN THE NORTHWEST AND FREEZING RAIN SOUTHWEST AFTER MIDNIGHT THROUGH DAYBREAK. PRECIPITATION SPREADS EASTWARD ON FRIDAY...MAINLY IN THE FORM OF RAIN IN THE SOUTHWEST AND FAR SOUTH CENTRAL BY LATE MORNING/AFTERNOON...AND IN THE FORM OF A WINTRY MIX ACROSS THE NORTHWEST AND NORTH CENTRAL. LIGHT AMOUNTS OF ONLY A FEW HUNDREDTHS UP TO A TENTH OF AN INCH ARE EXPECTED. REGARDING TEMPERATURES: LOWS TONIGHT MAINLY IN THE TEENS NORTH AND EAST OF THE MISSOURI RIVER AND IN THE 20S SOUTH AND WEST OF THE RIVER. STRONG WARM ADVECTION ON FRIDAY SHOULD ALLOW THE SNOW FREE AREAS OF THE SOUTHWEST TO WARM INTO THE MID 50S TO LOWER 60S (NOTING THAT HETTINGER HAD REACHED THE LOWER 50S AS OF 2 PM CDT THURSDAY). ACROSS THE SNOWPACK LOOK FOR HIGHS FRIDAY IN THE 30S. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 314 PM CDT THU MAR 28 2013 H5 PATTERN PER GFS/ECMWF/GEM ADVERTISE AN UPPER LOW FORECAST TO MOVE FROM THE NORTHWEST TERRITORIES OF CANADA FRIDAY NIGHT INTO THE NORTHERN GREAT LAKES BY EARLY NEXT WEEK. IN DOING SO...A NORTHWESTERLY FLOW ALOFT WILL BECOME FIRMLY ENTRENCHED INTO NORTH DAKOTA FOR THE WEEKEND AND INTO THE EARLY/MIDDLE PART OF NEXT WEEK. A COUPLE OF SHORTWAVES WILL MOVE THROUGH WITH THEIR ASSOCIATED SURFACE FEATURES/COLD FRONTAL PASSAGES...RESULTING IN COLDER AIR FOR THE WEEKEND. THE FIRST COLD FRONT IS FORECAST TO MOVE THROUGH FRIDAY NIGHT WITH A CHANCE OF A WINTRY MIX OF FREEZING RAIN/SLEET/OR RAIN. SATURDAY LOOKS DRY...A BIT COOLER BEHIND THE INITIAL COLD FRONT AS MENTIONED ABOVE. HOWEVER...THE MAIN SURGE OF THE COLDEST AIR WILL MOVE THROUGH SATURDAY NIGHT...AND REMAIN IN WESTERN AND CENTRAL NORTH DAKOTA THROUGH MONDAY MORNING. THIS IS WHEN THE MAIN H85 BAROCLINIC ZONE WITH TEMPERATURES AS COLD AS -16C DOMINATE MOST OF NORTH DAKOTA. WITH THAT BAROCLINIC ZONE PUSHING INTO THE SOUTHWEST...THE INTERACTION OF LOW LEVEL CONVERGENCE AND A 100KT H3 JET STREAK WILL PRODUCE ENOUGH LARGE SCALE ASCENT/H85-H3 OMEGA FOR AN AREA OF SNOW TO DEVELOP LATE SATURDAY NIGHT INTO SUNDAY IN THE SOUTHWEST. UPWARDS OF AROUND ONE INCH IS FORECAST BY SUNDAY EVENING IN THE SOUTHWEST. UPPER LEVEL RIDGING AND ITS ASSOCIATED SURFACE HIGH PRESSURE OF 1037MB WILL FOLLOW FOR MONDAY AND TUESDAY RESULTING IN DRY WEATHER. THE SURFACE HIGH IS FORECAST TO REACH NORTHWEST NORTH DAKOTA MONDAY MORNING PRODUCING THE COLDEST READINGS THERE...THEN SHIFTING INTO THE JAMES RIVER VALLEY BY TUESDAY MORNING. ON THE BACK SIDE OF THE HIGH PRESSURE...EXPECT A BRIEF RETURN OF MILDER AIR AS A LOW LEVEL SOUTHERLY FLOW INITIATES TUESDAY INTO TUESDAY NIGHT. ANOTHER COLD FRONT WHIPS THROUGH WEDNESDAY...HOWEVER PRECIPITATION LOOKS MINIMAL AT THIS TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 845 PM CDT THU MAR 28 2013 LIFR/VLIFR CONDITIONS IN DENSE FOG WILL CONTINUE AT KMOT AND KJMS POSSIBLY THROUGH 17-18 UTC FRIDAY. SIMILIAR CONDITIONS AT KBIS MAY IMPROVE SLIGHTLY FASTER IN THE 15-16 UTC TIME FRAME. AS OF 0530 UTC...KISN WAS ON THE FRINGE OF THE DENSE FOG BANK...AND MAY FALL INTO IFR CONDITIONS BY 08 UTC...AFTER WHICH MID LEVEL CLOUDS SPREAD ACROSS THE AREA AND MAY LIMIT FOG THEREAFTER FOR KISN. WITH WEAK UPSLOPE FLOW THROUGH THE NIGHT...KDIK MAY SEE A CONTINUED TREND TOWARDS MVFR/IFR VISIBILITIES IN FOG. FOR FRIDAY...SCATTERED PRECIPITATION POSSIBLY IN THE FORM OF FREEZING RAIN OR SLEET MAY IMPACT KISN AND KMOT...AND POSSIBLY KJMS FRIDAY EVENING. SCATTERED SHOWERS WITH POSSIBLY AN ISOLATED THUNDERSTORM IS POSSIBLE NEAR KDIK FRIDAY AFTERNOON. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM CDT /9 AM MDT/ THIS MORNING FOR NDZ001>005-009>013-019>023-025-034>037-042-045>048-050-051. && $$ UPDATE...AYD SHORT TERM...JV LONG TERM...KS AVIATION...AYD
AREA FORECAST DISCUSSION
NWS TULSA OK
1150 PM CDT THU MAR 28 2013 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS ARE THE NORM ACROSS THE AREA AT THIS TIME..THAT IS EXPECTED TO CHANGE SOME AS WE MOVE INTO FRIDAY MORNING WITH MVFR CONDITIONS DEVELOPING DUE TO CEILINGS AND SCATTERED SHOWERS AND THUNDERSTORMS. CONDITIONS WILL IMPROVE SOME LATE FRIDAY MORNING/EARLY AFTERNOON BEFORE MORE SHOWERS AND THUNDERSTORMS MOVE INTO THE AREA. && .PREV DISCUSSION... /ISSUED 910 PM CDT THU MAR 28 2013/ UPDATE... FORECAST WAS UPDATED TO REDUCE POPS THIS EVENING BASED ON LATEST DATA. SEE DISCUSSION BELOW. DISCUSSION... THE LATEST DATA FROM THE HRRR AND NEW 00Z NAM SUGGEST THAT THE ACTIVITY WILL BE SLOWER TO GET GOING TONIGHT...AND THUS POPS WERE REDUCED THRU 06Z. POPS AFT 06Z LOOK GOOD...AND ARE A GOOD COMPROMISE BETWEEN THE HRRR AND NAM SOLUTIONS. ISENTROPIC CHARTS EXPLAIN WHY THE ACTIVITY WILL BE SLOWER TO GET GOING...WITH LITTLE IN THE WAY OF ASCENT FORECAST THRU 06Z. BY 06Z AND AFTER...THE 295K SHOWS SOME LIFT AND GOOD MOISTURE TRANSPORT AIMED AT THE OZARK REGION. THERE IS STILL A LIMITED RISK OF AN ISOLATED SEVERE HAIL STORM WITH POTENTIAL FOR UP TO HALF DOLLAR SIZE GIVEN SUFFICIENT SHEAR AND INCREASING ELEVATED INSTABILITY ACROSS EASTERN OKLAHOMA AFT MIDNIGHT. LACY PREV DISCUSSION... /ISSUED 630 PM CDT THU MAR 28 2013/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. CONDITIONS WILL DETERIORATE TONIGHT WITH MVFR CONDITIONS DEVELOPING AFTER MIDNIGHT AND CONTINUING THROUGH FRIDAY MORNING. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO AFFECT AREA TAFS LATE TONIGHT INTO FRIDAY MORNING WITH SOME REDEVELOPED EXPECTED LATE FRIDAY AFTERNOON PRIOR TO THE EXPIRATION OF THE CURRENT TAF PERIOD. PREV DISCUSSION... /ISSUED 346 PM CDT THU MAR 28 2013/ DISCUSSION... A NEARLY STATIONARY FRONTAL BOUNDARY WAS POSITIONED FROM THE OKLAHOMA PANHANDLE TO SOUTHEAST KANSAS THIS AFTERNOON. SOUTH OF THE BOUNDARY...TEMPERATURES ARE RUNNING ABOUT 5 TO 10 DEGREES WARMER THAN THIS TIME YESTERDAY WITH HIGH CLOUDS AND SOUTHERLY WINDS BEING COMMON. LOW LEVEL MOISTURE HAS ALSO INCREASED FROM SOUTH TO NORTH ACROSS THE REGION THIS AFTERNOON...LIMITING FIRE WEATHER DANGERS FOR EASTERN OKLAHOMA AND NORTHWEST ARKANSAS. THE FRONTAL BOUNDARY JUST NORTH OF THE CWA WILL BE THE FOCUS FOR CHANCES OF SHOWERS AND THUNDERSTORMS OVER THE NEXT SEVERAL DAYS AS MID LEVEL WAVES PROGRESS THROUGH THE PLAINS WITHIN NORTHWESTERLY UPPER LEVEL FLOW. THE FIRST WAVE IS EXPECTED TO MOVE THROUGH TONIGHT AND FRIDAY...WITH A SECOND WAVE FRIDAY NIGHT AND SATURDAY. CHANCES FOR SHOWERS AND THUNDERSTORMS BECOME POSSIBLE THIS EVENING ACROSS THE REGION WITH GREATER CHANCES LATE TONIGHT AND FRIDAY ACROSS NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS. CHANCES THEN CONTINUE TO SPREAD SOUTHWARD FRIDAY EVENING AND SATURDAY WITH THE NEXT WAVE. WARM SURFACE TEMPS...STEEP LAPSE RATES AND COLD TEMPERATURES ALOFT DURING THIS TIME FRAME WILL ALLOW FOR INSTABILITY TO DEVELOP OVER THE REGION WHICH COULD ALLOW FOR SOME THUNDERSTORMS TO BECOME STRONG TO SEVERE WITH LARGE HAIL BEING THE MAIN THREAT. THE FRONTAL BOUNDARY IS PROGGED TO PUSH INTO EASTERN OKLAHOMA AND NORTHWEST ARKANSAS SATURDAY NIGHT AS A MORE DEFINED UPPER LEVEL WAVE DROPS SOUTHEAST OUT OF CANADA. THIS WILL CONTINUE CHANCES FOR SHOWERS AND THUNDERSTORMS INTO SUNDAY. LATEST MODEL SOLUTIONS ARE INDICATING THAT THE FRONTAL BOUNDARY COULD HANG UP NEAR THE RED RIVER VALLEY...WHICH WOULD CONTINUE PRECIP CHANCES ACROSS THE SOUTH DURING THE DAY SUNDAY. TEMPERATURES DURING THE DAY SUNDAY LOOK TO REMAIN WARM WITH HIGHS IN THE MID 60S TO LOW 70S POSSIBLE. THE WARM TEMPERATURES WILL BE QUICK TO MOVE OUT SUNDAY NIGHT AND MONDAY AS ANOTHER MORE STRONGER COLD FRONT PUSHES THROUGH THE REGION. CHANCES OF SHOWERS AND THUNDERSTORMS WILL AGAIN SPREAD OVER THE REGION DURING THE DAY MONDAY WITH THE MOVEMENT OF THE FRONT. BEHIND THE FRONT...MUCH COLDER AND DRIER AIR IS EXPECTED TO FILTER IN WITH TEMPERATURES DROPPING DURING THE DAY BEHIND THE FRONT. LOWS TUESDAY MORNING COULD POTENTIALLY REACH CLOSE TO FREEZING NEAR THE KANSAS BORDER. THIS FRONT LOOKS TO PUSH THROUGH THE REGION AND KEEP AN UPPER LEVEL WAVE MOVING OUT OF THE DESERT SOUTHWEST SOUTH OF THE REGION. THIS SHOULD KEEP PRECIP SOUTH OF THE REGION FOR THE MIDDLE PART OF THE WEEK. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...10
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
350 AM CDT FRI MAR 29 2013 .DISCUSSION... LATEST UPPER AIR ANALYSIS SHOWS TROUGHS OF LOW PRESSURE ACROSS THE NORTHEASTERN CONUS AND NORTHWESTERN CANADA. A SHORTWAVE CAN BE SEEN MOVING ONSHORE BAJA CALIFORNIA AND THIS DISTURBANCE WILL BE THE MAIN FOCUS FOR THE NEXT 24 HOURS. ON THE SURFACE...A LOW CENTER REMAINS POSITIONED NEAR THE TEXAS PANHANDLE WITH A TROUGH EXTENDING TO THE EAST INTO OKLAHOMA. THE 00Z FWD RAOB INDICATED A STOUT CAP IN PLACE AS WEST WINDS BETWEEN 700 AND 800 MB ARE LEADING TO WARM AIR ADVECTION. THIS CAP WILL KEEP NORTH TEXAS RAIN FREE FOR MOST OF THE DAY TODAY. THE FORECAST THEN BECOMES PROBLEMATIC AS THE SHORTWAVE NEARS THE REGION THIS EVENING. THE MODELS DIFFER ON THE HANDLING OF THIS SYSTEM AND THE WEAKENING OF THE CAP BY LATE AFTERNOON. THE GFS KEEPS THE CAP IN PLACE AND MOST OF THE AREA RAIN FREE...WHILE THE NAM/WRF/CANADIAN/ECMWF ALL WEAKEN THE CAP TO SOME DEGREE. THE NAM IS THE MOST AGGRESSIVE WITH THE REMOVAL OF THE CAP COMPLETELY BY 00Z. CURRENTLY ON WATER VAPOR THE SHORTWAVE LOOKS STRONGER THAN WHAT MOST MODELS HAVE INITIALIZED. THE DISTURBANCE IS STRONG ENOUGH THAT IT CAN BE SEEN ON CONSTANT PV SURFACES AS THE TROPOPAUSE DESCENDS IN THE ATMOSPHERE WITHIN THE CENTER OF THE TROUGH OF LOW PRESSURE. THE 00-HR RAP IS CURRENTLY INITIALIZING THIS TO OCCUR AT 330 MB...WHILE THE GFS AND NAM ARE AT 280 MB AND 295 MB RESPECTIVELY. WITH THE STRONGER TROUGH...WILL HOLD MORE WEIGHT WITH THE NAMS FORECAST OF ERODING THE CAP THIS AFTERNOON. HIGH-RES MODELS ARE INITIALIZING THUNDERSTORM DEVELOPMENT WEST/NORTHWEST OF THE FORECAST AREA...NEAR THE SURFACE LOW BEFORE 00Z THIS EVENING. PREVIOUS THINKING WAS THE CAP WOULD HOLD AND THESE STORMS WOULD WEAKEN AS THEY PROGRESSED EAST...RUNNING INTO THE CAP. IF THE CAP DOES ERODE...THERE SHOULD BE A DECENT COVERAGE OF STORMS INTO THE NORTHWEST ZONES AFTER 00Z. WITH CAPE VALUES NEAR 1500 J/KG AND MODERATE SHEAR VALUES A STRONG TO MARGINALLY SEVERE STORM IS POSSIBLE. OVERNIGHT...A COMPLEX OF STORMS IS EXPECTED TO DEVELOP NEAR THE SURFACE TROUGH IN OKLAHOMA AND THIS ACTIVITY COULD CLIP OUR NORTHEASTERN ZONES NEAR SUNRISE SATURDAY. AFTER THIS SYSTEM MOVES OUT ON SATURDAY...THINK THE REMAINDER OF THE DAY SHOULD BE RELATIVELY QUIET AS NO LARGE SCALE FORCING FOR ASCENT IS IN PLACE. SATURDAY NIGHT...THE TROUGH THAT IS CURRENTLY IN NORTHWESTERN CANADA WILL CONTINUE TO SLIDE SOUTHEAST AND SEND A COLD FRONT INTO SOUTHERN OKLAHOMA. THIS FRONT COMBINING WITH ANOTHER WEAK EMBEDDED SHORTWAVE WILL BRING MORE THUNDERSTORM CHANCES TO MAINLY THE NORTHERN ZONES. THIS FRONTAL BOUNDARY IS EXPECTED TO STALL NEAR THE I-20 CORRIDOR SUNDAY AFTERNOON AS THE UPPER LOW SHIFTS EAST. WITH THE SURFACE FOCUS IN PLACE FOR THE CWA...ADDITIONAL THUNDERSTORMS ARE POSSIBLE FOR THE AREA. CAPE VALUES MAY EXCEED 2000 J/KG AS LOWER 60 DEWPOINTS WILL BE IN PLACE. SHEAR IS EXPECTED TO BE WEAKER AND THIS WILL LIMIT THE OVERALL SEVERE POTENTIAL...BUT CANT RULE OUT A STRONG OR MARGINALLY SEVERE STORM SUNDAY AFTERNOON. ANOTHER SOUTHWARD MOVING IMPULSE OF UPPER ENERGY OUT OF CANADA WILL SEND A STRONGER FRONT SOUTH ON MONDAY. THIS FRONT IS EXPECTED TO MOVE THROUGH THE CWA MONDAY EVENING AND WILL CARRY ADDITIONAL THUNDERSTORM CHANCES WITH THE FROPA. MEDIUM RANGE GUIDANCE HAS HAD POOR RUN-TO-RUN CONSISTENCY WITH THE HANDLING OF FEATURES BEYOND MONDAY. THE 00Z GFS AND ECMWF ARE SIMILAR AND KEEP STRONG UPGLIDE ON TOP OF THE FRONTAL INVERSION THROUGH TUESDAY NIGHT AND WILL KEEP SLIGHT TO CHANCE POPS FOR LIGHT RAIN IN THE FORECAST. AFTER A VERY ACTIVE PERIOD...THE FINAL CHANCE OF RAIN WILL COME WHEN THE UPPER TROUGH CURRENTLY OVER THE PACIFIC OCEAN WILL SWING THROUGH THE AREA WEDNESDAY/WEDNESDAY NIGHT. MODELS LAST NIGHT SHOWED THIS LOW WEAKENING BEFORE IT MOVED THROUGH...BUT TONIGHT KEEP IT AS A STRONGER CLOSED LOW. THE TRACK OF THE LOW IS DIFFERENT BETWEEN THE GFS AND ECMWF...BUT BOTH SHOW LARGE SCALE FORCING FOR ASCENT AND WILL FORECAST 30 POPS FOR WEDNESDAY AND WEDNESDAY NIGHT. AGAIN...MODELS HAVE HAD A HARD TIME WITH THE FORECAST BEYOND MONDAY AND CONFIDENCE IS NOT HIGH. NEVERTHELESS...AN UNSETTLED WEATHER PATTERN IS EXPECTED BETWEEN TODAY AND NEXT WEDNESDAY WITH RAIN CHANCES IN THE FORECAST EACH DAY FOR MOST OF THE AREA. IT WONT RAIN EVERYDAY FOR ALL LOCATIONS...BUT CHANCES ARE THERE EACH DAY. TEMPERATURES THROUGH MONDAY WILL BE IN THE 70S/80S FOR HIGHS WITH LOWS IN THE 50S/60S. AFTER MONDAY...TEMPERATURES WILL BE DRASTICALLY COLDER BEHIND THE FRONT. HIGHS BEHIND THE FRONT TUESDAY AND WEDNESDAY WILL BE IN THE 40S/50S FOR HIGHS WITH LITTLE DIURNAL RANGE GIVEN THE CLOUD COVER AND RAIN CHANCES. SOUTH WINDS WILL RETURN BY THE END OF THE WEEK AND MODERATING TEMPERATURES CAN BE EXPECTED. HAMPSHIRE && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 77 62 80 62 76 / 10 30 20 40 40 WACO, TX 77 61 79 64 79 / 5 20 20 20 40 PARIS, TX 73 58 75 60 74 / 20 50 30 50 40 DENTON, TX 75 61 80 58 75 / 10 30 20 40 40 MCKINNEY, TX 75 61 80 60 76 / 10 30 20 40 40 DALLAS, TX 77 62 81 63 76 / 10 30 20 40 40 TERRELL, TX 76 62 79 63 75 / 10 30 20 30 40 CORSICANA, TX 76 60 77 62 78 / 10 20 20 20 40 TEMPLE, TX 76 61 78 62 81 / 5 10 20 20 30 MINERAL WELLS, TX 77 57 83 59 78 / 10 40 20 30 40 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /
AREA FORECAST DISCUSSION...CORRECTED
NWS LA CROSSE WI
1137 PM CDT THU MAR 28 2013 .SHORT TERM...TONIGHT THROUGH SUNDAY 345 PM CDT THU MAR 28 2013 AT 3 PM...A 1028 MB SURFACE HIGH WAS CENTERED OVER SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST WISCONSIN. DESPITE THIS HIGH PRESSURE AREA...A BROKEN DECK OF MID CLOUDS WERE LOCATED ACROSS THIS AFOREMENTIONED AREA. THIS WAS DUE TO MODERATE WARM AIR ADVECTION AHEAD OF A SHORT WAVE MOVING THROUGH SOUTHWEST MINNESOTA. OVERALL THE 28.17Z RAP MODEL IS HANDLING THESE CLOUDS THE BEST. THEY SHOW THAT THESE MID CLOUDS WILL MOVE SOUTHEAST OUT OF THE AREA BY 29.03Z...AND THEN SOME MORE MID CLOUDS WILL MOVE BACK INTO THE AREA FROM WESTERN MINNESOTA AND DAKOTAS AFTER 29.06Z. THESE CLOUDS ARE THE RESULT OF SOME WARM AIR ADVECTION AHEAD OF YET ANOTHER SHORT WAVE TROUGH MOVING OUT OF NORTH DAKOTA. SOUNDINGS SUGGEST THAT THIS MOISTURE WILL LIMITED TO A 100 TO 150 MB LAYER AROUND 700 MB. AS A RESULT...NOT EXPECTING ANY PRECIPITATION FROM THIS WAVE. THIS IS IN DESPITE THE GFS TRYING TO GENERATE SOME PRECIPITATION JUST UPSTREAM OF THE FORECAST AREA. FROM LATE FRIDAY NIGHT INTO SATURDAY EVENING...A STRONG SHORT WAVE TROUGH WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA. AHEAD OF THIS WAVE...THERE WILL BE MODERATE TO STRONG 290K ISENTROPIC LIFT...AND MODERATE 925 MB TO 850 MB MOISTURE TRANSPORT. THIS WILL RESULT IN THE DEVELOPMENT OF A BAND OF RAIN ALONG AND AHEAD OF THIS FRONT. INSTABILITY STILL LOOKS LIMITED WITH MOST UNSTABLE CAPES CLIMBING UP TO 100 J/KG. AS A RESULT...LEFT ISOLATED THUNDERSTORMS IN THE FORECAST MAINLY ALONG AND SOUTH OF INTERSTATE 90. TEMPERATURES AT THE ONSET OF THIS PRECIPITATION MAY RESULT IN A BRIEF WINTRY MIX OF FREEZING RAIN AND SLEET MAINLY NORTHEAST OF INTERSTATE 94. THERE MAY BE A BRIEF PERIOD OF GLAZING. HOWEVER... IT WILL SHORT-LIVED AS TEMPERATURES CLIM QUICKLY INTO THE 40S. ON SUNDAY...A STRONG CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE FORECAST AREA. THERE IS VERY LITTLE 925 AND 850 MB MOISTURE TRANSPORT ASSOCIATED WITH THIS FRONT. IN THE WAKE OF THIS FRONT...THERE WILL BE MODERATE 290K ISENTROPIC LIFT. HOWEVER SUBSIDENCE IN THE WAKE OF THIS FRONT WILL CAUSE CONDENSATION PRESSURE DEFICITS TO RISE INTO THE 50 TO 100 MB RANGE. AS A RESULT...THERE IS A QUESTION ON WHETHER THERE WILL BE ENOUGH MOISTURE FOR ANY RAIN AND SNOW SHOWERS DURING THE AFTERNOON AND EVENING...THUS...KEPT PRECIPITATION CHANCES ON THE LOW SIDE MAINLY NORTH OF INTERSTATE 94. .LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY 345 PM CDT THU MAR 28 2013 FROM SUNDAY NIGHT INTO TUESDAY...IT CONTINUES TO LOOK LIKE ANOMALOUS COLD AIR MASS WILL BE LOCATED ACROSS THE AREA. THE ECMWF 850 TEMPERATURES ARE RUNNING 1 TO 1.5 STANDARD DEVIATIONS BELOW NORMAL ON MONDAY...AND AROUND 1 STANDARD DEVIATION BELOW NORMAL ON TUESDAY. THIS WILL RESULT IN HIGH TEMPERATURES IN THE LOWER AND MID 30S ON MONDAY...AND IN THE MID AND UPPER 30S ON TUESDAY. ON WEDNESDAY...ANOTHER COLD FRONT WILL MOVE SOUTHEAST THROUGH THE REGION. AT THIS TIME...IT LOOKS LIKE THE BEST MOISTURE AND LIFT WILL BE TO OUR NORTH...THUS KEPT THE FORECAST DRY. LOOKING AHEAD TO THE FIRST HALF OF APRIL...THE CFS VERSION 2 CONTINUES TO SHOW THAT THE AREA WILL SEE PREDOMINANTLY NORTHWEST FLOW. AS A RESULT...IT CONTINUES TO SHOW COLDER-THAN-NORMAL TEMPERATURES PERSISTING THROUGH THIS TIME PERIOD. THE MAIN REASON FOR THIS IS THAT THE ARCTIC OSCILLATION REMAINS NEGATIVE. && .AVIATION...FRIDAY 1137 PM CDT THU MAR 28 2013 QUIET VFR CONDITIONS WILL PREVAIL FOR MOST OF FRIDAY AS HIGH PRESSURE SLOWLY RETREATS EASTWARD. JUST PATCHY MID LEVEL CLOUDS MOVING THROUGH WESTERN GREAT LAKES AS LOW LEVEL FLOW BECOMES SOUTHEASTERLY THROUGH THE MORNING. DEW POINTS A BIT HIGHER CLOSER TO INTERSTATE 35 AND WITH TEMPERATURES STAYING UP COULD SEE SOME LIGHT FOG /4-6SM BR/ DEVELOP OVER PARTS OF NORTHEAST IOWA AND SOUTHEAST MINNESOTA. ALREADY SEEING SOME MINOR RESTRICTIONS TO VISIBILITIES CLOSER TO SOUTH DAKOTA BORDER. SOME INCREASE IN CLOUDS NOTED AHEAD OF CANADIAN SHORT WAVE TROUGH BY FRIDAY EVENING BUT PRECIPITATION THREAT SHOULD HOLD OFF UNTIL AFTER 30/06Z. && .HYDROLOGY... 345 PM CDT THU MAR 28 2013 DUE TO A MELTING SNOWPACK OVER THE LAST SEVERAL DAYS...MANY RIVERS ACROSS NORTHEAST IA/SOUTHEAST MN/AND SOUTHWEST WI HAVE EXPERIENCED WITHIN BANK RISES OF 2 TO 4 FEET. IN AREAS WHERE THE SNOW HAS MELTED...SOME OF THE FROST HAS MELTED IN THE TOP FEW INCHES OF THE SOIL...THIS IS ALLOWING SOME OF THE SNOW MELT TO GET INTO THE TOP SOILS. THIS MOISTURE THEN FREEZES IN THE TOP SOILS AT NIGHT. THIS IS LIMITING THE AMOUNT OF RUNOFF INTO THE RIVERS. ON SATURDAY...LOOK FOR A QUARTER TO HALF INCH OF RAIN. THIS WILL ADD ONTO THE RUNOFF FROM THE SNOW MELT. HOWEVER THE WARM RAINS WILL HELP TO MELT SOME FROST IN THE TOP SOILS...SO NOT LOOKING FOR COMPLETE RUNOFF LIKE WE HAD EARLIER IN THE MONTH. WHILE NO FLOODING IS EXPECTED AT THIS TIME...PEOPLE LIVING NEAR OR HAVING INTERESTS ALONG RIVER WAYS ARE URGED TO MONITOR LATEST RIVER FORECASTS AND STATEMENTS. && .ARX WATCHES/WARNINGS/ADVISORIES... 243 PM CDT THU MAR 28 2013 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION....SHEA HYDROLOGY...DAS/BOYNE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
709 AM EDT FRI MAR 29 2013 .SYNOPSIS... MILD AND MAINLY DRY WEATHER IS EXPECTED THROUGH THE FIRST PART OF THE WEEKEND. A SERIES OF FRONTS WILL BRING SOME WET WEATHER SUNDAY NIGHT INTO MONDAY...WITH COLDER WEATHER EXPECTED INTO THE MID PART OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 7 AM UPDATE... ONLY MINOR TWEAKS NEEDED TO THE FORECAST THIS MORNING. UPDATED SKIES TOWARD LATEST RAP SOLUTION GIVEN IT IS HANDLING SOME MID CLOUDS OVER SRN NEW HAMPSHIRE AND CLOUDS UPSTREAM ASSOCIATED WITH A SHORTWAVE EXPECTED TO MOVE OVER THE AREA TODAY. STILL EXPECTING ANOTHER ROUND OF DIURNALLY DRIVEN SHOWERS PARTICULARLY CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA...SO HAVE ADJUSTED POPS SOMEWHAT AS WELL. OTHERWISE...ASIDE FROM BRINGING TEMPS AND DWPTS UP TO CURRENT TRENDS...OTHER PARAMETERS REMAIN ON TRACK. PREVIOUS DISCUSSION... A MIXTURE OF CLOUDS AND SUNSHINE THIS MORNING WILL PROBABLY GIVE WAY TO MORE IN THE WAY OF CLOUDINESS DURING THE AFTERNOON. THIS A RESULT OF A MID LEVEL SHORTWAVE APPROACHING FROM THE WEST AND 500 MB TEMPS DROPPING BELOW -30C. THIS SHOULD RESULT IN ENOUGH INSTABILITY FOR ISOLATED SHOWERS TO DEVELOP DURING THE AFTERNOON. HOWEVER...AREAL COVERAGE OF ANY ACTIVITY THAT DEVELOPS SHOULD BE LIMITED AND THE VAST MAJORITY OF THE DAY SHOULD BE DRY IN A GIVEN LOCATION. THEREFORE...JUST WILL INCLUDE LOW POPS IN THE FORECAST. AS FOR HIGH TEMPS...THE ATMOSPHERE SHOULD BE WELL MIXED WITH NORTHWEST SURFACE WINDS. SO DESPITE 850 MB TEMPS AROUND -3C...HIGH TEMPS SHOULD REACH WELL INTO THE 50S ACROSS MOST LOCATIONS. WEAK GRADIENT MAY ALLOW FOR SEA BREEZES TO DEVELOP ALONG THE VERY IMMEDIATE COAST...RESULTING LOCALLY COOLER TEMPS IN THIS REGION DURING THE AFTERNOON. && .SHORT TERM /SATURDAY/... TONIGHT... ISOLATED DIURNALLY DRIVEN SHOWERS SHOULD DISSIPATE DURING THE EVENING HOURS. HOWEVER...CONSIDERABLE CLOUDINESS MAY LINGER WELL INTO THE OVERNIGHT HOURS GIVEN COLD POOL ALOFT AND A FAIR AMOUNT OF MID LEVEL MOISTURE. THEREFORE...THINK GUIDANCE NUMBERS MAY BE A BIT TOO COOL AND LOW TEMPS WILL MAINLY BE IN THE UPPER 20S TO THE MIDDLE 30S IN MOST LOCALES. SATURDAY... A NICE START TO THE WEEKEND IS ON TAP FOR SOUTHERN NEW ENGLAND. THE UPPER TROUGH BEGINS TO MOVE EAST OF THE REGION ALLOWING FOR RISING HEIGHT FIELDS. THIS SHOULD YIELD MAINLY DRY WEATHER AND MORE SUNSHINE THAN TODAY. HIGHS AGAIN SHOULD BE IN THE LOWER TO MIDDLE 50S ACROSS MOST LOCALES. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... * WARMER TEMPERATURES EXPECTED THROUGH THE WEEKEND * SHOWERS EXPECTED AHEAD OF WARM FRONT SUN AND MON * COOLER WEATHER MOVES BACK IN TUES AND WED OVERVIEW AND MODEL PREFERENCES... 29/00Z MODEL GUIDANCE SUITE IS BEGINNING TO CONVERGE ON BROAD SCALE PATTERN THROUGH MUCH OF THE LONG TERM. MAINLY IN THAT THEY CONTINUE THE GREENLAND BLOCK THAT HAS BEEN IN PLACE FOR MUCH OF THE LAST MONTH OR SO. THEREFORE THE CUTOFF LOW PRES ASSOCIATED WITH THE EARLY WEEK OCCLUSION/COLD FRONTAL PASSAGE WILL STALL IN THE NEWFOUNDLAND LABRADOR REGION...DRAWING A FAIR AMOUNT OF COLD AIR INTO SRN NEW ENGLAND THROUGH NEXT WEEK. WILL CONTINUE TO ERR TOWARD A GFS/ECMWF BLEND AS A BASELINE. THE ONLY CAVEAT WILL BE A SECONDARY ARCTIC FROPA STALLING S OF THE REGION AND SECONDARY SHORTWAVE AND SFC LOW WHICH WILL PASS ALONG IT ON TUE. LATEST GFS IS MORE SUPPRESSED...LEANING CLOSER TO ITS ENSEMBLE MEAN...WHILE ECMWF HAS ALWAYS BEEN AB IT MORE SUPPRESSED. THERE IS STILL THE SLIGHT THREAT FOR SOME LIGHT PRECIP /WHAT WOULD LIKELY BE SNOW/ ALONG THE S COAST WITH THIS WAVE...SO WILL MAINTAIN AT LEAST SLIGHT CHANCE POPS /CLOSER TO THE ECWMF SOLUTION/ ON TUE. DETAILS... SAT NIGHT INTO SUN... UPPER LVL RIDGE AND SFC HIGH PRES CREST OVER THE REGION AND BEGINS TO SLIDE E. THIS ALLOWS FOR WARM ADVECTION UNDER RETURN FLOW INTO SUN. THEREFORE...WARM TEMPS /POSSIBLY APPROACHING 60/ ARE LIKELY DISPUTE INCREASING CLOUDS IN ADVANCE OF OCCLUDED FRONT. MUCH OF THE DAY REMAINS DRY ALTHOUGH AREAS NEAR AND W OF THE CT VALLEY MAY BEGIN TO SEE SOME RAIN BY LATE AFTERNOON AND EVENING. SUN NIGHT AND MON... MODELS STILL SHOWING DECENT OCCLUSION PUSHING THROUGH THE AREA AS LOW PRES PASSES WELL N OF THE ST LAWRENCE VALLEY. DECENT MOISTURE AND LIFT SUPPORT WIDESPREAD QPF VALUES AROUND A HALF INCH ALTHOUGH WITH PWAT VALUES CLOSER TO 0.75-1.0 INCHES...A FEW LOCALLY HIGHER AMOUNTS ARE POSSIBLE. GIVEN THE WARM START AND DECENT RIDGING THE PRECIP WILL LIKELY REMAIN MOSTLY RAIN...ALTHOUGH THERMAL PROFILES DO SUGGEST THAT HIGHER TERRAIN OF SRN MA AND NRN MA MAY CHANGE OVER BRIEFLY LATE SUN NIGHT...WITH LITTLE ACCUMULATION. STEERING FLOW SUGGESTS THIS FRONT IS A FAST MOVER AND PRECIP MAY LIKELY DONE EVERYWHERE SAVE FOR MAYBE EXTREME N AND E LOCATIONS NOT LONG AFTER 06Z. HOWEVER...AFTER A BRIEF LULL...A SECONDARY ARCTIC FRONT IS EXPECTED TO PUSH THROUGH DURING THE AFTERNOON...PRECIP FROM THIS TOO WILL LIKELY BE SHOWERY AND MOSTLY RAIN TO START BUT A BRIEF CHANGE-OVER TO SNOW CANNOT BE RULED OUT THANKS TO A VERY COLD AIRMASS BUILDING IN FROM THE W BEHIND THE FRONT ESPECIALLY TOWARD THE OVERNIGHT HOURS. EXPECTING THAT THE FRONT SHOULD BE OFFSHORE BY EARLY OVERNIGHT MON NIGHT. TUE.... THE KEY HERE IS A MIX OF HOW QUICKLY SFC RIDGING MOVES IN AND WHERE THE ARCTIC FRONT STALLS IN PROXIMITY TO SRN NEW ENGLAND. THE ECMWF AND SOME ECENS/GEFS MEMBERS CONTINUE TO KEEP THE BAROCLINIC ZONE FROM THE DELMARVA TO ABOUT THE BENCHMARK...WHILE THE GFS AND A FEW ENSEMBLE MEMBERS ARE FURTHER S. WHEN A SECONDARY WAVE MOVES THROUGH A WEAK LOW PRES IS EXPECTED TO MOVE ALONG THIS WAVE. THE CLOSER PASS /ECMWF/ WOULD SUGGEST SOME PRECIP /LIKELY MOSTLY SNOW...ALTHOUGH SOME RAIN COULD STILL MIX IN GIVEN THE EARLY APRIL SUN ANGLE/ ESPECIALLY S OF THE MA PIKE WHILE THE GFS IS DRY. WILL STILL AT LEAST HAVE POPS BECAUSE THE POTENTIAL IS THERE GIVEN THE UPSTREAM BLOCK...BUT WILL NEED TO MONITOR THE SHORTWAVE ONCE IT BECOMES BETTER SAMPLED. WED INTO FRI... UPPER LVL CUTOFF HOLDS NEAR LABRADOR-NEWFOUNDLAND ALLOWING FOR A DRAW OF SEASONABLY COLD AIR INTO THE REGION AS STRONG HIGH PRES BUILDS OVER FROM THE W. LIKELY SEE MOSTLY DRY CONDITIONS WITH TEMPERATURES GENERALLY BELOW NORMAL FOR EARLY APRIL. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. OVERVIEW...HIGH CONFIDENCE THROUGH SATURDAY AFTERNOON. VFR CONDITIONS DOMINATE MUCH OF THE DAY WITH SOME EVEN WITH SOME LOWER STRATO-CU EXPECTED TO BUILD IN THROUGH THE DAY. CAN/T RULE OUT SOME ISOLATED MVFR CIGS/VSBYS ASSOCIATED WITH SOME DIURNALLY DRIVEN SHOWERS PARTICULARLY DURING THE AFTERNOON HOURS. KBOS TAF...HIGH CONFIDENCE IN VFR BUT LOWER CONFIDENCE IN WIND DIRECTION. MAIN CONCERN IS THE POTENTIAL FOR A WEAK SEABREEZE DEVELOPMENT DURING THE AFTERNOON. WILL CARRY IT IN THE TAF DUE TO POTENTIAL...BUT SHOULD WINDS NEVER QUITE DIMINISH BELOW 10 KT MAY BE VERY LOW POTENTIAL IN SEA BREEZE COMING ONSHORE. WILL NEED TO KEEP AN EYE ON WINDS THROUGH THE DAY. KBDL TAF...HIGH CONFIDENCE IN TAF. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SAT NIGHT INTO EARLY SUN AFTERNOON...HIGH CONFIDENCE. VFR. LIGHT AND VRB WINDS BECOME MORE SW INTO SUN. LATE DAY SUN INTO MON...MODERATE CONFIDENCE. VFR GIVES WAY TO MIX OF MVFR AND POTENTIALLY IFR IN RAIN. BULK OF RAIN OCCURS EVENING AND EARLY OVERNIGHT SUN NIGHT WITH A BREAK EARLY MON. POSSIBLE MVFR AGAIN WITH COLD FRONT DURING MON AFTERNOON. TUESDAY...MODERATE TO HIGH CONFIDENCE. MAINLY VFR. && .MARINE... HIGH CONFIDENCE THROUGH SATURDAY AFTERNOON. WEAK PRESSURE GRADIENT WILL KEEP WINDS/SEAS BELOW SCA THRESHOLDS THROUGH THAT TIME. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SAT NIGHT INTO EARLY SUN...HIGH CONFIDENCE. WINDS AND SEAS REMAIN BELOW SMALL CRAFT THRESHOLDS THROUGH THE PERIOD. SUN NIGHT THROUGH TUE...MODERATE CONFIDENCE. A SERIES OF FRONTS CROSS THE WATERS SUN NIGHT AND MON. THIS WILL ALLOW WINDS TO APPROACH 25 KT AT TIMES PARTICULARLY ON THE OUTER WATERS. SEAS ALSO GRADUALLY BUILD TO 5-8 FT ON OUTER WATERS WHICH WILL LIKELY LINGER INTO TUE. SMALL CRAFT ADVISORIES ARE LIKELY NEEDED THROUGH THE PERIOD. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...FRANK/DOODY NEAR TERM...FRANK/DOODY SHORT TERM...FRANK LONG TERM...DOODY AVIATION...FRANK/DOODY MARINE...FRANK/DOODY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
949 AM CDT FRI MAR 29 2013 .DISCUSSION... ISSUED 948 AM CDT FRI MAR 29 2013 HIGH PRESSURE AXIS CURRENTLY ANALYZED FROM WISCONSIN SOUTHEAST INTO THE CAROLINAS. EARLIER WARM AIR ADVECTION SHOWERS HAVE SHIFTED INTO THE OHIO VALLEY...ALTHOUGH SOME ALTOCUMULUS LINGERS IN THE FORECAST AREA AND HAVE EVEN HAD A FEW SPRINKLES OUT OF IT AROUND CHAMPAIGN. WHILE THE ALTOCUMULUS SHOULD DIMINISH WITH TIME...CU-RULE OFF THE RAP MODEL SHOWS SOME DIURNAL CUMULUS POTENTIAL FOR THIS AFTERNOON...WITH THE NET RESULT BEING PARTLY TO MOSTLY SUNNY SKIES. MORNING COOPERATIVE OBSERVATIONS SHOWING ONLY 1 TO 3 INCHES OF SNOW LINGERING FROM NEAR LINCOLN SOUTHWEST TO PITTSFIELD AND TRACE AMOUNTS EASTWARD...AND MUCH OF THIS SHOULD DISAPPEAR TODAY AS HIGHS REACH INTO THE 50S. HAVE SENT SOME UPDATED GRIDS TO ADJUST HOURLY TRENDS...BUT NO CHANGES NEEDED TO THE ZONE FORECASTS AT THIS TIME. GEELHART && .AVIATION... ISSUED 615 AM CDT FRI MAR 29 2013 MAIN FORECAST CONCERN THIS PERIOD WILL BE COVERAGE OF LOW VFR CIGS...ESP ACRS OUR SOUTHERN TAF (KSPI...KDEC AND KCMI) SITES LATER THIS MORNING INTO THE AFTERNOON HOURS. NOT MANY CHANGES PLANNED TO CURRENT SET OF TAFS AS MOISTURE FROM A DISTURBANCE PASSING TO OUR SOUTH MAY KEEP THE LOWER VFR CIGS AROUND A BIT LONGER ACROSS THE SOUTH BEFORE THEY PUSH OFF TO THE EAST AND SOUTH BY LATE AFTN...LEAVING MAINLY VFR CONDITIONS FOR TNT. WILL HAVE TO WATCH FOR THE POSSIBILITY OF SOME PATCHY FOG DEVELOP LATE TONIGHT BUT AT THIS TIME IT APPEARS THAT PROBABILITY IS TOO LOW TO INCLUDE IN THIS SET OF TAFS. WINDS WILL NOT BE A FACTOR THRU TNT WITH SPEEDS OF LESS THAN 10 KTS...MOSTLY OUT OF AN EASTERLY DIRECTION. SMITH && .PREV DISCUSSION... ISSUED 236 AM CDT FRI MAR 29 2013 SHORT TERM...TODAY THROUGH SATURDAY SURFACE RIDGE AXIS EXTENDING FROM THE UPPER MS VALLEY SOUTHEAST INTO THE OHIO VALLEY PROVIDED LIGHT WINDS OVERNIGHT. SCATTERED SHOWERS WERE AFFECTING SOUTHERN MO IN THE VICINITY OF A SFC WARM FRONT...WHILE ELEVATED WARM ADVECTION WAS PRODUCING SHOWERS INTO SOUTHERN IL. OBSERVATIONAL TRENDS SUGGEST THIS ACTIVITY WILL REMAIN SOUTH OF THE AREA THIS MORNING...BUT MAIN AFFECT FOR MOST AREAS WILL BE AREAS OF AC AND MOSTLY CLOUDY SKIES THIS MORNING. AS THE SYSTEM SINKS SOUTHEAST...A CLEARING TREND WORKS IN FROM THE NORTH THIS AFTERNOON. WILL ADD A FEW DEGREES TO YESTERDAYS HIGHS WITH MOST AREAS GETTING INTO THE LOW/MID 50S. A COLD FRONT MOVING ACROSS THE STATE SATURDAY AFTERNOON/NIGHT BRINGS SCATTERED SHOWERS WITH GENERALLY LIGHT QPF OF A QUARTER TO LESS THAN A HALF INCH. 00Z NAM HAD TRENDED MUCH QUICKER WITH THIS FEATURE BRINGING SHOWERS ALL THE WAY TO EASTERN IL BY SAT AFTERNOON. FEEL THIS IS A BIT FAST AND HAVE BASED FORECAST ON SREF/GFS BLEND WHICH BRINGS RAIN WEST OF THE IL RIVER BY MID TO LATE AFTERNOON...THEN SHIFTS EAST ACROSS THE REMAINDER OF THE CWA THROUGH EVENING. SOUTHERLY FLOW AHEAD OF THE FRONT WILL PRODUCE THE WARMEST DAY OF THE MONTH FOR MANY AREAS WITH HIGHS IN THE UPPER 50S. LONG TERM...SUNDAY THROUGH THURSDAY NOT MUCH OF A COOL PUSH BEHIND THE INITIAL FRONT AND READINGS EXPECTED TO GET BACK UP INTO THE 50S SUNDAY ALONG WITH A FAIR AMOUNT OF SUNSHINE. AN ARCTIC FRONT DIVING IN FROM THE NORTH SUNDAY NIGHT SENDS TEMPERATURES CRASHING BACK WELL BELOW NORMAL. FRONTOGENETIC FORCING ALONG/BEHIND THE BOUNDARY WILL WRING OUT WHAT MOISTURE REMAINS AFTER THE PREVIOUS FRONTAL PASSAGE. THERMAL PROFILES SUGGEST THE BULK OF THE PRECIP TO FALL AS SNOW AFTER A BRIEF RAIN/SNOW MIX AT ONSET SUNDAY NIGHT. NAM MOST AGGRESSIVE AT BRINGING ACCUMULATING SNOW...BUT GIVEN PROGRESSIVE NATURE OF FRONT AND WARM GROUND FEEL ANY ACCUMULATIONS WILL BE MINOR. SNOW SHOULD EXIT THE SOUTH/EAST MONDAY MORNING. BRISK NORTHERLY WINDS ON THE EASTERN FLANK OF STRONG LATE SEASON 1035 MB ARCTIC HIGH BUILDING INTO THE NORTHERN PLAINS...BRINGS STRONG COLD ADVECTION. 850 MB TEMPS DIP AS LOW AS -12C ACROSS CENTRAL IL MONDAY AFTERNOON THROUGH TUESDAY. THIS PRODUCES TEMPERATURES 20+ DEGREES BELOW NORMAL WHICH MAY NOT BE TOO FAR FROM RECORD TERRITORY. IN CONTRAST TO THE LAST ARCTIC AIR MASS...CYCLONIC FLOW IS DISPLACED MUCH FARTHER NORTHEAST THIS TIME AROUND AND SHOULD RESULT IN MORE SUNSHINE BY DAY AND CLEAR COLD NIGHTS. UNSEASONABLY COLD AND DRY WEATHER CONTINUES THROUGH MID WEEK AS THE MODIFIED ARCTIC RIDGE SETTLES OVERHEAD. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
623 AM EDT FRI MAR 29 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 523 AM EDT FRI MAR 29 2013 WEAK SHORT WAVE AND ASSOCIATED JET STREAK MOVING ACROSS THE GREAT LAKES THIS MORNING. COUPLED WITH WEAK MID LEVEL THETA E ADVECTION THESE FEATURES HAVE HELPED GENERATE AN AREA OF MID LEVEL CLOUDS THIS MORNING JUST TO OUR WEST. RAP13 SEEMS TO HAVE BEST HANDLE ON THIS MOISTURE WITH ITS 850-700MB LAYER RH. HRRR IS TRYING TO CATCH UP BUT STILL DOES NOT APPEAR TO HAVE THE SCOPE SEEN ON SATELLITE. SPECTRAL MODELS GENERALLY CLUELESS. SHORT WAVE WILL PASS THROUGH OUR AREA DURING EARLY TO MID MORNING HOURS. RAP13 MOVES HIGHER RH VALUES ACROSS WESTERN HALF OF OUR AREA THIS MORNING AND GRADUALLY SINKS THIS AREA SOUTH WHILE MIXING ALSO HELPS TO ERODE CLOUDS. HAVE INCREASED CLOUD COVER THIS MORNING SUBSTANTIALLY ACROSS WESTERN AREAS USING SATELLITE TRENDS AND RAP AS GUIDANCE. GRADUALLY DECREASED AMOUNT OF SKY COVER BY EARLY AFTERNOON SO SHOULD SEE A PARTLY TO MOSTLY CLOUDY MORNING TRANSITIONING TO MOSTLY SUNNY THIS AFTERNOON. EASTERN AREAS TO REMAIN FAR ENOUGH REMOVED PER TRAJECTORIES TO KEEP MOSTLY SUNNY THROUGH THE DAY. RESULT OF THIS MAY HELP KEEP TEMPS DOWN A FEW DEGREES WEST BUT EXPECT RAPID INCREASE ONCE CLOUDS DEPART. OTHERWISE TEMPS WILL BE A FEW DEGREES WARMER THAN THURSDAY OUTSIDE OF CLOUDS. WARMER TEMPS ON SATURDAY AHEAD OF NEXT SHORT WAVE WITH HIGHS NEARING 60. INCREASING HIGH CLOUDS IN AFTERNOON MAY SLOW WARMING BUT IF SKIES REMAIN CLEAR WOULD EXPECT SOME AREAS INTO 60S GIVEN MOS COOL BIAS YESTERDAY WITH FULL SUN. STRONG THETA E SURGE WITH MID LEVEL TROUGH APPROACHING SAT NIGHT SHOULD LEAD TO RAIN SHOWERS. MODELS CONTINUE TO TREND FASTER WITH NAM12 SHOWING PCPN DURING FIRST HALF OF NIGHT. USED COMPROMISE OF SOLUTIONS FOR TIMING BUT LOOKS LIKE ALL AREAS WILL RECEIVE A NICE RAINFALL OF ONE QUARTER TO ONE HALF INCH. ELEVATED THUNDER STILL NOT OUT OF QUESTION BUT REMAINS LOW PROB EVENT SO NO INCLUSION JUST YET. IF WE CAN GET SOME LIGHTNING WITH THIS RAIN RAPID GREEN UP WOULD BE EXPECTED IN WAKE OF RAIN. && .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 523 AM EDT FRI MAR 29 2013 SUNDAY THROUGH THURSDAY...A WEAK UPPER LEVEL TROF WILL BE MOVING ACROSS THE AREA SUNDAY...FOLLOWED BY A COLD FRONT SUNDAY NIGHT. THERMAL PROFILES SUNDAY ARE BORDERLINE BETWEEN RAIN AND A RAIN/SNOW MIX SUNDAY MORNING OVER NORTHERN AREAS...ESPECIALLY THE GFS. FOR NOW LEFT JUST RAIN IN THE FCST GIVEN SFC TEMPERATURES MAINLY IN THE 40S AND NAM 1000/850 MB THICKNESSES ALMOST EXCLUSIVELY ABOVE 1300 METERS. VERY CHILLY AIR WILL ONCE AGAIN SPREAD ACROSS THE AREA SUNDAY NIGHT AND MONDAY. DELTA T VALUES SUPPORT SOME LAKE EFFECT SNOW SHOWERS...HOWEVER...VERY LITTLE PRECONDITIONING IS EXPECTED. A 300 TO 310 FETCH WITH UPSTREAM DEW PTS IN THE SINGLE DIGITS MAY NOT ALLOW MUCH MORE THAN LAKE EFFECT CLOUDS. OTHERWISE...ATTEMPTED TO TREND TEMPERATURES DOWN MONDAY NIGHT THROUGH WEDNESDAY IN LINE WITH THE GFS MEX MOS. 850 MB TEMPS TUESDAY MORNING NEAR -14C TUESDAY WILL HELP KEEP HIGHS IN THE 30S...ESPECIALLY NEAR THE LAKE WITH LAKE ENHANCED CLOUDS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 622 AM EDT FRI MAR 29 2013 VFR CONDITIONS EXPECTED THROUGH THE PERIOD. SATELLITE SHOWS AREA OF MID LEVEL CLOUDS THINNING WITH TIME AS THEY MOVE EAST INTO DRIER AIR AND MID LEVEL JET MAX EXITS REGION. A FEW MORE HOURS OF OCCASIONAL BKN080 POSSIBLE THIS MORNING BEFORE BECOMING SCT. WINDS WILL REMAIN LIGHT THIS MORNING AND SHOULD STAY UNDER 10 KNOTS TODAY. CLEAR SKIES AND LIGHT WINDS AGAIN TONIGHT. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS TOPEKA KS
914 AM CDT FRI MAR 29 2013 .UPDATE... ISSUED AT 901 AM CDT FRI MAR 29 2013 NO MAJOR UPDATES TO THE FORECAST. INTITIALIZED FORECAST GRIDS WITH 900 AM OBSERVATIONS. GARGAN && .SHORT TERM AND LONG TERM...(TODAY THROUGH THURSDAY) ISSUED AT 414 AM CDT FRI MAR 29 2013 MOST RECENT SHORTWAVE TROUGH AT 08Z EXTENDING FROM IA INTO KS IS MOVING SOUTHEAST AND WILL EXIT THE CWA EARLY THIS MORNING. THIS WAVE IN CONJUNCTION WITH ISENTROPIC LIFT NORTH OF THE STATIONARY BOUNDARY TO THE SOUTH HAS RESULTED IN NUMEROUS ELEVATED SHOWERS AND THUNDERSTORMS PRIMARILY SOUTH OF I 70. AS THE WAVE AND LIFT SHIFT SOUTHEAST AND MUCH DRIER AIR ALOFT OVERSPREADS THE AREA...PRECIP CHANCES WILL DIMINISH BY SUNRISE LEAVING A DRY FCST ACROSS THE COUNTY WARNING AREA FOR THE REMAINDER OF THE DAY. CLOUDS WILL ALSO DECREASE OVER THE SOUTHERN AREA EARLY LEAVING MOSTLY SUNNY SKIES MOST AREAS. HAVE THEREFORE BUMPED UP HIGHS FOR TODAY INTO THE MIDDLE TO UPPER 60S ALL AREAS. AS THE LLVL FLOW VEERS TONIGHT AND BECOMES MORE SOUTH/SOUTHWESTERLY...MOISTURE WILL ONCE AGAIN SURGE BACK TO THE NORTH...MAINLY FROM LATE EVENING THROUGH THE MORNING HOURS ON SATURDAY. THE BETTER FOCUS FOR FORCING/CONVERGENCE AND ISENTROPIC LIFT WILL OCCUR ACROSS PRIMARILY THE NORTHERN CWA AND HAVE MAINTAINED HIGHER END CHANCE POPS IN THIS AREA...THEN DECREASED SOUTHWARD. AS THE NEXT FRONT MOVES SOUTHEAST ACROSS THE CWA ON SATURDAY...THE AXIS OF HIGHER CAPE/INSTABILITY WILL SET UP ACROSS THE SOUTHEAST PORTIONS OF THE CWA IN THE AFTERNOON...PRIMARILY SOUTH AND EAST OF THE TURNPIKE. IF INHIBITION IS ERODED...STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE IN THIS AREA INTO THE EVENING HOURS BEFORE DECREASING AND EXITING THE SOUTHEAST CORNER BY MIDNIGHT. UP TO QUARTER SIZE HAIL AND STRONG GUSTY WINDS WOULD BE THE PRIMARY THREAT WITH THE STRONGER CELLS. SUNDAY IS STILL LOOKING DRY AHEAD OF THE NEXT...MUCH STRONGER COLD FRONT ON MONDAY. A WEDGE OF WARM AIR WILL STILL RESIDE ACROSS THE CWA OUT AHEAD OF THIS FRONT AND HAVE THEREFORE INCREASED SUNDAYS HIGH TEMPS INTO THE MIDDLE TO UPPER 60S. AS THE FRONT THEN TRAVERSES THE CWA FROM NORTH TO SOUTH...AT LEAST SCATTERED POST FRONTAL RAIN SHOULD DEVELOP AND MAY MIX WITH AND/OR CHANGEOVER TO ALL SNOW LATE SUNDAY NIGHT AND MONDAY BEFORE ENDING BY AFTERNOON. ANY SNOWFALL ACCUMULATIONS AT THIS POINT APPEAR TO BE GENERALLY LESS THAN AN INCH. EITHER WAY...MUCH COLDER CONDITIONS WITH HIGHS IN THE UPPER 30S TO LOW 40S ARE IN STORE FOR THE AREA ON MONDAY. THE AREA SHOULD GRADUALLY TRANSITION FROM COOLER NORTHWEST FLOW ALOFT TO A MORE ZONAL PATTERN THROUGH THE WEEK RESULTING IN MODERATING TEMPERATURES. HIGHS SHOULD RISE INTO THE 50S BY WEDNESDAY...THEN THE 60S BY THURSDAY. WILL MAINTAIN A DRY FCST THROUGH THE REMAINDER OF THE WEEK. 63 && .AVIATION... 11Z WATER VAPOR IMAGERY SHOWS THE WEAK UPPER WAVE BEGINNING TO PASS TO THE EAST. WITH THE RAP AND NAM SHOWING ISENTROPIC LIFT DIMINISHING...THINK ELEVATED SHOWERS WILL CONTINUE TO MOVE OFF TO THE EAST. MODELS DO NOT SHOW THE MOISTURE ADVECTION AND ISENTROPIC LIFT RETURNING UNTIL AFTER 02Z SAT. UNTIL THEN EXPECT VFR CONDITIONS DUE TO A LACK OF STRONG FORCING AND THE BOUNDARY REMAINING TO THE SOUTH AND WEST. UNCERTAINTY IN LOCATION OF PRECIP OVERNIGHT PRELUDES ANY MENTION OTHER THAN A VCSH ONCE THE 850 WINDS VEER AROUND TO THE SOUTHWEST AND BEGIN TO LIFT MOISTURE BACK INTO NORTHEAST KS LATE THIS EVENING. WOLTERS && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GARGAN SHORT TERM...63 LONG TERM...63 AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1107 AM CDT FRI MAR 29 2013 .DISCUSSION... SEE PREV DISCUSSION. && .AVIATION... 11Z WATER VAPOR IMAGERY SHOWS THE WEAK UPPER WAVE BEGINNING TO PASS TO THE EAST. WITH THE RAP AND NAM SHOWING ISENTROPIC LIFT DIMINISHING...THINK ELEVATED SHOWERS WILL CONTINUE TO MOVE OFF TO THE EAST. MODELS DO NOT SHOW THE MOISTURE ADVECTION AND ISENTROPIC LIFT RETURNING UNTIL AFTER 02Z SAT. UNTIL THEN EXPECT VFR CONDITIONS DUE TO A LACK OF STRONG FORCING AND THE BOUNDARY REMAINING TO THE SOUTH AND WEST. UNCERTAINTY IN LOCATION OF PRECIP OVERNIGHT PRELUDES ANY MENTION OTHER THAN A VCSH ONCE THE 850 WINDS VEER AROUND TO THE SOUTHWEST AND BEGIN TO LIFT MOISTURE BACK INTO NORTHEAST KS LATE THIS EVENING. WOLTERS && .PREV DISCUSSION... /414 AM CDT FRI MAR 29 2013/ MOST RECENT SHORTWAVE TROUGH AT 08Z EXTENDING FROM IA INTO KS IS MOVING SOUTHEAST AND WILL EXIT THE CWA EARLY THIS MORNING. THIS WAVE IN CONJUNCTION WITH ISENTROPIC LIFT NORTH OF THE STATIONARY BOUNDARY TO THE SOUTH HAS RESULTED IN NUMEROUS ELEVATED SHOWERS AND THUNDERSTORMS PRIMARILY SOUTH OF I 70. AS THE WAVE AND LIFT SHIFT SOUTHEAST AND MUCH DRIER AIR ALOFT OVERSPREADS THE AREA...PRECIP CHANCES WILL DIMINISH BY SUNRISE LEAVING A DRY FCST ACROSS THE COUNTY WARNING AREA FOR THE REMAINDER OF THE DAY. CLOUDS WILL ALSO DECREASE OVER THE SOUTHERN AREA EARLY LEAVING MOSTLY SUNNY SKIES MOST AREAS. HAVE THEREFORE BUMPED UP HIGHS FOR TODAY INTO THE MIDDLE TO UPPER 60S ALL AREAS. AS THE LLVL FLOW VEERS TONIGHT AND BECOMES MORE SOUTH/SOUTHWESTERLY...MOISTURE WILL ONCE AGAIN SURGE BACK TO THE NORTH...MAINLY FROM LATE EVENING THROUGH THE MORNING HOURS ON SATURDAY. THE BETTER FOCUS FOR FORCING/CONVERGENCE AND ISENTROPIC LIFT WILL OCCUR ACROSS PRIMARILY THE NORTHERN CWA AND HAVE MAINTAINED HIGHER END CHANCE POPS IN THIS AREA...THEN DECREASED SOUTHWARD. AS THE NEXT FRONT MOVES SOUTHEAST ACROSS THE CWA ON SATURDAY...THE AXIS OF HIGHER CAPE/INSTABILITY WILL SET UP ACROSS THE SOUTHEAST PORTIONS OF THE CWA IN THE AFTERNOON...PRIMARILY SOUTH AND EAST OF THE TURNPIKE. IF INHIBITION IS ERODED...STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE IN THIS AREA INTO THE EVENING HOURS BEFORE DECREASING AND EXITING THE SOUTHEAST CORNER BY MIDNIGHT. UP TO QUARTER SIZE HAIL AND STRONG GUSTY WINDS WOULD BE THE PRIMARY THREAT WITH THE STRONGER CELLS. SUNDAY IS STILL LOOKING DRY AHEAD OF THE NEXT...MUCH STRONGER COLD FRONT ON MONDAY. A WEDGE OF WARM AIR WILL STILL RESIDE ACROSS THE CWA OUT AHEAD OF THIS FRONT AND HAVE THEREFORE INCREASED SUNDAYS HIGH TEMPS INTO THE MIDDLE TO UPPER 60S. AS THE FRONT THEN TRAVERSES THE CWA FROM NORTH TO SOUTH...AT LEAST SCATTERED POST FRONTAL RAIN SHOULD DEVELOP AND MAY MIX WITH AND/OR CHANGEOVER TO ALL SNOW LATE SUNDAY NIGHT AND MONDAY BEFORE ENDING BY AFTERNOON. ANY SNOWFALL ACCUMULATIONS AT THIS POINT APPEAR TO BE GENERALLY LESS THAN AN INCH. EITHER WAY...MUCH COLDER CONDITIONS WITH HIGHS IN THE UPPER 30S TO LOW 40S ARE IN STORE FOR THE AREA ON MONDAY. THE AREA SHOULD GRADUALLY TRANSITION FROM COOLER NORTHWEST FLOW ALOFT TO A MORE ZONAL PATTERN THROUGH THE WEEK RESULTING IN MODERATING TEMPERATURES. HIGHS SHOULD RISE INTO THE 50S BY WEDNESDAY...THEN THE 60S BY THURSDAY. WILL MAINTAIN A DRY FCST THROUGH THE REMAINDER OF THE WEEK. 63 && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
948 AM EDT FRI MAR 29 2013 .UPDATE... ISSUED AT 948 AM EDT FRI MAR 29 2013 MESONET DATA SHOWING MEASURABLE RAIN HAS OCCURRED OVER MOST OF WESTERN KY AND AS FAR SOUTHEAST AS CUMBERLAND COUNTY. RAIN ALSO FALLING AS FAR NORTH AS EVV INDIANA. RADAR SHOWS MOVEMENT OF RAIN TO THE ESE...SO EXPECT NUMEROUS SHOWERS TO AFFECT THE FAR SOUTHWEST AND FAR SOUTHERN PART OF THE FORECAST AREA. THIS IS SUPPORTED BY SREF PROBABILITIES AND LATEST DATA FROM THE HRRR AND NAM. AS SUCH HAVE UPDATED NDFD AND ZFP TO INCREASE RAIN PROBABILITIES IN THE FAR SOUTHWEST AND FAR SOUTH TODAY. UPDATE ISSUED AT 740 AM EDT FRI MAR 29 2013 UPDATED THE FORECAST TO BETTER REFLECT CURRENT CONDITIONS AND MODEL TRENDS. ONLY MADE SOME SLIGHT CHANGES TO TEMPERATURES...DEW POINTS CLOUDS AND WINDS IN THE FIRST TWO PERIODS. THE REST OF THE FORECAST IS ON TRACK. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 308 AM EDT FRI MAR 29 2013 A WEAK WEATHER SYSTEM WILL BRING SOME LIGHT RAIN TO THE SOUTHWESTERN HALF OF EASTERN KENTUCKY TODAY. THIS SYSTEM IS A WARM FRONT WHICH WILL TRY MOVING INTO THE AREA BUT THEN BE PUSHED BACK TO THE SOUTH TONIGHT. THIS WILL MAKE FOR A DRY SATURDAY BEFORE THE NEXT SYSTEM STARTS PUSHING ITS WAY INTO THE AREA ON SATURDAY NIGHT. THE JURY IS OUT ABOUT HOW MUCH RAIN THE WEAK SYSTEM TODAY WILL BE ABLE TO PRODUCE. IT MAY BE A LOT OF CLOUDS AND SOME SPRINKLES...AT BEST AND JUST A COUPLE OF HUNDREDTHS OF AN INCH OF RAIN AT THE WORST. AS YOU MOVE TO THE NORTHEAST FROM WAYNE COUNTY...THE CHANCE FOR MEASURABLE RAIN DECREASES. EXPECTING HIGHS IN THE MID 50S TODAY AND THEN NEAR 60 ON SATURDAY AS SOME WARMER AIR WORKS ITS WAY INTO THE AREA. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 412 AM EDT FRI MAR 29 2013 THE GFS AND ECMWF ARE IN GOOD AGREEMENT THROUGH THE PERIOD. FOR THE LOCAL AREA THEY SHOW A WARM AIR ADVECTION REGIME DEVELOPING IN ADVANCE OF A COLD FRONT SATURDAY NIGHT...WITH THE COLD FRONT THEN PASSING THROUGH ON SUNDAY. THERE APPEARS TO BE A DECENT AMOUNT OF MOISTURE WHICH MAKES ITS WAY IN FROM THE GULF BEFORE THE FRONT ARRIVES...AND LIKELY POPS FROM GFS MEXMOS SEEM REASONABLE. MARGINAL DEEP INSTABILITY IS ALSO INDICATED...AND IS WORTH A MENTION OF A SLIGHT CHANCE OF THUNDER. ANY LINGERING PRECIP IN THE SOUTH AND EAST ASSOCIATED WITH THE COLD FRONT SHOULD EXIT MONDAY EVENING. HOWEVER...THERE IS ADDITIONAL POTENTIAL FOR MORE PRECIP TOWARD THE END OF THE NIGHT...ALBEIT SMALL. THE NAM SHOWS A WAVE PASSING TO OUR SOUTH AND GRAZING OUR AREA...WHILE THE GFS AND ECMWF ARE FURTHER SOUTH WITH IT. WITH THE NAM BEING THE ONLY MODEL THAT EVEN GETS PRECIP TO THE EDGE OF OUR AREA...WILL NOT BRING ANY PRECIP INTO THE LOCAL AREA WITH THIS SYSTEM. HOWEVER...ALL THREE MODELS SHOW ANOTHER COLD FRONT MOVING IN FROM THE NW TOWARD MONDAY MORNING. WHILE THEY KEEP THE DEEP MOISTURE WITH THE FRONT NEAR OR NORTH OF THE OHIO RIVER...CONFIDENCE IN TIMING IS NOT GOOD ENOUGH TO PRECLUDE PRECIP HERE...AND HAVE ALLOWED FOR A SLIGHT CHANCE IN THE NORTH AT DAWN. WILL USE CHANCE POPS FOR RAIN ON MONDAY AS THE FRONT MOVES THROUGH. HAVE RESERVED THE HIGHEST POPS WITH THIS FRONT...STILL IN CHANCE CATEGORY...FOR MONDAY NIGHT AS A WAVE MOVES ALONG THE FRONT AFTER IT HAS PASSED. UP UNTIL MONDAY THE PRECIP FORM SHOULD BE LIQUID...BUT ENOUGH COLD AIR ARRIVES TO THREATEN SNOW BEFORE POPS DROP OFF LATE MONDAY NIGHT. LARGE...COLD...SPRAWLING SURFACE HIGH PRESSURE THEN HEADS IN FROM THE NW AND IS EXPECTED TO BRING DRY WEATHER INTO THURSDAY. LOW PRESSURE PASSING WELL TO OUR SOUTH THURSDAY AND THURSDAY NIGHT LOOKS AT THIS POINT LIKE IT WILL GRAZE THE SOUTHERN PART OF THE FORECAST AREA WITH RAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 740 AM EDT FRI MAR 29 2013 VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. HIGH CLOUDS AND MIDDLE CLOUDS HAVE ARRIVED AND WILL BE LOWERING THROUGH THE DAY TODAY. ISOLATED LIGHT SHOWER POSSIBLE BY MID DAY IN THE CUMBERLAND VALLEY. MAINTAINED A VCSH AND CIGS AROUND 5K FEET FOR THIS IN THE LOZ AND SME TAFS. WINDS WILL HAVE A W TO WNW TENDENCY...AT 5 KTS OR LESS THROUGH THE PERIOD AS WELL. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...JJ LONG TERM...HAL AVIATION...JJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
926 AM EDT FRI MAR 29 2013 .Forecast Update... Issued at 926 AM EDT Fri Mar 29 2013 Quick update to raise PoPs to 100% where it is currently raining and sky cover to 100% where it is currently overcast. Also bumped up precipitation amounts a bit based on totals coming in from western Kentucky this morning. && .Short Term (Now - Saturday)... Issued at 300 AM EDT Fri Mar 29 2013 An upper level shortwave and weak sfc boundary were located to our WSW early this morning producing showers and t-storms from eastern KS to western KY. The latest RAP model guidance seems to be handling this area of precip quite well, so have relied on it for short term POPs. Rain showers look likely across portions of south central KY this morning before moving south of the area into TN this afternoon. Think that better lapse rates out west are producing the t-storms with this wave and do not anticipate those better lapse rates to translate eastward so will not include thunder in this forecast. For high temperatures today, have gone with mid 50s over southern Indiana and north central KY which will see less cloud cover overall and no precip. Lower 50s can be expected for highs over south central KY where rain is anticipated. Tonight sfc high pressure will quickly work in from the north allowing for dry conditions and only partly cloudy skies across southern IN and northern KY. Went with a decent temp gradient due to cloud cover with low to mid 30s for lows over southern IN/northern KY to upper 30s and lower 40s over south central KY. The next push of moisture doesn`t look to arrive until late Sat afternoon or evening as a warm front pushes into south central KY. Therefore, limited POP chances to just the afternoon hours over south central KY for Sat. The rest of the area should be dry and warm up quite nicely. With only partly cloudy skies anticipated during the morning and early afternoon, went with high temps in the low to mid 60s. .Long Term (Saturday Night - Thursday)... Issued at 300 AM EDT Fri Mar 29 2013 Cold front number one will be fast approaching from the northwest Saturday night. Rain and a few embedded rumbles of thunder will overspread the forecast area Saturday night and through the morning hours Sunday. Rain chances will diminish from west to east late Sunday morning, with a dry period anticipated from roughly Sunday afternoon through Sunday night. A second cold front will quickly enter the forecast area from the north Monday and sag south through Monday night. Expect rain chances to increase through the day Monday and rain should exit the southern CWA by Tuesday morning. Temperatures will fall behind the front Monday night and soundings indicate the potential for some smaller ice crystal growth. It appears the loss of moisture/ice crystals within the dendritic growth layer will limit large snowflake generation. So, there could be some light snow mixed with the rain overnight as the system exits. Then, high pressure will build across the Ohio Valley, with the active storm track being pushed well to our south. The only question is whether a southern track system Thursday will be deep enough to increase moisture and rain potential across the Ohio and Tennessee Valleys as it tracks across the Gulf States. Rain probabilities are low for Thursday, with an overall slower trend noted in latest guidance. Will go with a dry forecast Tuesday through Thursday, with perhaps a slight rain chance across our south and southeast CWA just beyond the long-term period. The cold front that swings through the area early Sunday will not be followed by a cold air mass. Still expect temperatures in the 60s Sunday afternoon. However, the passage of the second front on Monday will bring a return to unseasonably cool conditions through Thursday. The good news is temperatures appear to moderate some through the work week. So, while highs in the 40s are expected Tuesday, highs Thursday appear to reach the middle 50s. && .Aviation (12Z TAF Issuance)... Issued at 645 AM EDT Fri Mar 29 2013 VFR conditions are expected for this TAF period. Mid and upper level clouds will continue to stream into the area this morning and continue through the day as an upper level shortwave passes through south central KY. This wave looks to bring precip in the form of rain showers to BWG today. These showers have made it into the BWG terminal with the main push of moisture progged to occur from roughly 13Z-20Z. SDF/LEX still look to remain dry although will need to monitor the northern extent of the precip shield to make sure it doesn`t creep into SDF. The 0Z NAM indicates MVFR conditions will develop at BWG today, but feel it is an outlier at this point compared to other model runs and upstream obs. Still will need to watch BWG for some cig/vsby restrictions today. Winds will be hard to pin down throughout the TAF period. Generally they will remain light (under 5 kts). Variable winds can be expected during the early morning hours and again tonight. Think that the predominant wind direction at BWG this afternoon will be SSE with SDF/LEX winds predominantly SSW. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. $$ Update...........13 Short Term.......AMS Long Term........MJP Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
648 AM EDT FRI MAR 29 2013 ...Updated Aviation Discussion... .Short Term (Now - Saturday)... Issued at 300 AM EDT Fri Mar 29 2013 An upper level shortwave and weak sfc boundary were located to our WSW early this morning producing showers and t-storms from eastern KS to western KY. The latest RAP model guidance seems to be handling this area of precip quite well, so have relied on it for short term POPs. Rain showers look likely across portions of south central KY this morning before moving south of the area into TN this afternoon. Think that better lapse rates out west are producing the t-storms with this wave and do not anticipate those better lapse rates to translate eastward so will not include thunder in this forecast. For high temperatures today, have gone with mid 50s over southern Indiana and north central KY which will see less cloud cover overall and no precip. Lower 50s can be expected for highs over south central KY where rain is anticipated. Tonight sfc high pressure will quickly work in from the north allowing for dry conditions and only partly cloudy skies across southern IN and northern KY. Went with a decent temp gradient due to cloud cover with low to mid 30s for lows over southern IN/northern KY to upper 30s and lower 40s over south central KY. The next push of moisture doesn`t look to arrive until late Sat afternoon or evening as a warm front pushes into south central KY. Therefore, limited POP chances to just the afternoon hours over south central KY for Sat. The rest of the area should be dry and warm up quite nicely. With only partly cloudy skies anticipated during the morning and early afternoon, went with high temps in the low to mid 60s. .Long Term (Saturday Night - Thursday)... Issued at 300 AM EDT Fri Mar 29 2013 Cold front number one will be fast approaching from the northwest Saturday night. Rain and a few embedded rumbles of thunder will overspread the forecast area Saturday night and through the morning hours Sunday. Rain chances will diminish from west to east late Sunday morning, with a dry period anticipated from roughly Sunday afternoon through Sunday night. A second cold front will quickly enter the forecast area from the north Monday and sag south through Monday night. Expect rain chances to increase through the day Monday and rain should exit the southern CWA by Tuesday morning. Temperatures will fall behind the front Monday night and soundings indicate the potential for some smaller ice crystal growth. It appears the loss of moisture/ice crystals within the dendritic growth layer will limit large snowflake generation. So, there could be some light snow mixed with the rain overnight as the system exits. Then, high pressure will build across the Ohio Valley, with the active storm track being pushed well to our south. The only question is whether a southern track system Thursday will be deep enough to increase moisture and rain potential across the Ohio and Tennessee Valleys as it tracks across the Gulf States. Rain probabilities are low for Thursday, with an overall slower trend noted in latest guidance. Will go with a dry forecast Tuesday through Thursday, with perhaps a slight rain chance across our south and southeast CWA just beyond the long-term period. The cold front that swings through the area early Sunday will not be followed by a cold air mass. Still expect temperatures in the 60s Sunday afternoon. However, the passage of the second front on Monday will bring a return to unseasonably cool conditions through Thursday. The good news is temperatures appear to moderate some through the work week. So, while highs in the 40s are expected Tuesday, highs Thursday appear to reach the middle 50s. && .Aviation (12Z TAF Issuance)... Issued at 645 AM EDT Fri Mar 29 2013 VFR conditions are expected for this TAF period. Mid and upper level clouds will continue to stream into the area this morning and continue through the day as an upper level shortwave passes through south central KY. This wave looks to bring precip in the form of rain showers to BWG today. These showers have made it into the BWG terminal with the main push of moisture progged to occur from roughly 13Z-20Z. SDF/LEX still look to remain dry although will need to monitor the northern extent of the precip shield to make sure it doesn`t creep into SDF. The 0Z NAM indicates MVFR conditions will develop at BWG today, but feel it is an outlier at this point compared to other model runs and upstream obs. Still will need to watch BWG for some cig/vsby restrictions today. Winds will be hard to pin down throughout the TAF period. Generally they will remain light (under 5 kts). Variable winds can be expected during the early morning hours and again tonight. Think that the predominant wind direction at BWG this afternoon will be SSE with SDF/LEX winds predominantly SSW. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. $$ Short Term.......AMS Long Term........MJP Aviation.........AMS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
959 AM EDT FRI MAR 29 2013 .SYNOPSIS... ISSUED AT 329 AM EDT FRI MAR 29 2013 HIGH PRESSURE WILL ADVANCE FROM THE UPPER MIDWEST THROUGH THE GREAT LAKES TO ROUND OUT TODAY. THIS PATTERN WILL BRING SUNSHINE THROUGH THE FIRST HALF OF SATURDAY. TEMPERATURES WILL ALSO FINALLY...ALTHOUGH BRIEFLY...WARM ABOVE NORMAL FOR THE FIRST HALF OF THE WEEKEND. THAT TREND WILL BE SHORT LIVED...AS A STRONG COLD FRONT ARRIVES SATURDAY NIGHT...WITH A ROUND OF RAIN OR SNOW SHOWERS LIKELY. AS THE FRONT PASSES...MUCH COLDER WEATHER WILL ARRIVE LATER SUNDAY AND STICK AROUND THROUGH AT LEAST TUESDAY...WITH PERIODIC LAKE EFFECT SNOW SHOWERS AND WINDY CONDITIONS. && .UPDATE... ISSUED AT 959 AM EDT FRI MAR 29 2013 PATCHY STRATUS CONTINUES IN EASTERN CHIPPEWA CO AND OVER WHITEFISH BAY...THOUGH HAS BROKEN UP SOMEWHAT OVER THE SAULTS PROPER. THE STRATUS SHOULD ERODE AND MIX OUT OVER THE NEXT 3 HOURS. TEMPS HAVE REBOUNDED INTO THE MID 20S TO MID 30S...DO NOT PLAN ON ANY SIGNIFICANT CHANGES TO THE MAX TEMP FORECAST. UPDATE ISSUED AT 613 AM EDT FRI MAR 29 2013 CHANGES THIS HOUR: COULDN/T QUITE GET THROUGH THE OVERNIGHT WITHOUT DEALING WITH SOME STRATUS. A PATCH HAS POPPED UP OVER THE PAST HOUR FROM KANJ NORTH INTO THE HIGH TERRAIN EAST OF WHITEFISH BAY ACROSS THE BORDER IN ONTARIO. NEAR TERM RUC PROGS SUGGEST THAT SOMEWHAT ENHANCED H9 MOISTURE FROM THIS AREA EAST WILL MOVE EAST AND AWAY FROM THE REGION THIS MORNING. DON/T EXPECT THIS TO GET TOO OUT OF HAND/WIDESPREAD...BUT WILL CARRY SOME ADDITIONAL CLOUDINESS THROUGH THE NEXT FEW HOURS AS EARLY MORNING INVERSION WILL ALLOW ANYTHING THAT DEVELOPS TO PERSIST FOR A TIME. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 329 AM EDT FRI MAR 29 2013 HIGH IMPACT WEATHER POTENTIAL: NONE. OVERVIEW: EARLY MORNING WATER VAPOR IMAGERY REVEALS RECENT BLOCKING OVER EASTERN CANADA RETREATING EAST AS BROAD NORTHWEST FLOW BEGINS TO TAKE OVER ALOFT ACROSS THE GREAT LAKES REGION. THE CLOSED HIGH ASSOCIATED WITH THIS BLOCK HAS OPENED UP...AND WAS OVERHEAD AS SHORTWAVE RIDGING YESTERDAY AND HAS NOW PUSHED INTO THE NORTHEASTERN CONUS AS OF THIS MORNING. MOVING DOWN TO THE SURFACE...A MODEST SURFACE RIDGE AXIS IS DRAPED FROM JUST WEST OF THE WESTERN LAKES INTO INDIANA/KENTUCKY...WHICH HAS PROVIDED CALM/QUIET WEATHER ACROSS THE GREAT LAKES REGION. 00Z APX RAOB SHOWED -4C AT H8...JUST ABOUT NORMAL FOR THIS TIME OF YEAR WITH OUR AVERAGE TEMPERATURE FOR THE DATE YESTERDAY SIMILARLY CLOSE TO NORMAL. WITH THIS HIGH OVERHEAD AND THE MAJORITY OF ANY JET ENERGY RESIDING OVER THE SOUTHEASTERN STATES...THE WEATHER LOOKS QUIET THROUGH THE SHORT TERM PORTION OF THE FORECAST...BUT THE AFOREMENTIONED BREAKING DOWN OF THE BLOCK OVER CANADA PORTENDS THAT THIS QUIET STRETCH OF WEATHER WILL BE COMING TO AN END SOON...SO DON/T GET USED TO WHAT YOU SEE TODAY! THROUGH DAYBREAK: TERRIFIC RADIATIONAL COOLING CONDITIONS ALLOWING SOME SPOTS TO REACH 20F AS OF THIS WRITING...WITH A WEAK WIND KEEPING SOME HIGHER TERRAIN SPOTS AS WELL AS THE NE LOWER COAST IN THE UPPER 20S TO AROUND 30 UNDER CLEAR SKIES. LITTLE CHANGE THROUGH DAYBREAK...WITH SOME LOCAL SLICK SPOTS LIKELY AS AFTERNOON PUDDLES REFREEZE. TODAY: WEAK SHORTWAVE TROUGH NOW EXITING TO THE SOUTHEAST OF THE REGION WILL ALLOW FOR GRADUALLY BUILDING MID LEVEL HEIGHTS /ALONG WITH MID LEVEL NVA/ TODAY WITH THE RIDGE OF SURFACE HIGH PRESSURE SLIDING EAST INTO THE REGION. LLEVEL TRAJECTORIES SHOW TODAY/S AIRMASS ARRIVING FROM WESTERN ONTARIO 24 HOURS PREVIOUSLY...AND A LOOK AT YESTERDAY/S CONDITIONS THERE SHOW NO CUMULUS DEVELOPMENT /DEWPOINTS FALLING INTO THE LOWER-MID TEENS/ ALONG WITH LOWER 40S FOR HIGHS. GIVEN THE OVERHEAD HIGH PRESSURE AND NVA...WILL ALLOW FOR SOME WARMING TO THIS AIRMASS THROUGH SUBSIDENCE WHICH SUGGESTS TRENDING TOWARDS THE WARMER ECMWF-MOS GUIDANCE TODAY...YIELDING HIGHS IN THE MID-UPPER 40S MOST LOCATIONS UNDER SUNNY SKIES... WARMEST SOUTHEASTERN AREAS WHERE LAKE INFLUENCE ON TEMPS WILL BE LESS. TONIGHT: HIGH PRESSURE SETTLES OVERHEAD WITH SHORT-WAVE RIDGING CONTINUING/SHARPENING AT MID LEVELS IN RESPONSE TO OUR NEXT WEATHER MAKER DROPPING SOUTH OUT OF CENTRAL CANADA. THIS WILL LIKELY SPREAD SOME HIGH CLOUDINESS INTO THE REGION AFTER MIDNIGHT...BUT FOR THE MOST PART EXPECT ANOTHER CALM/CLEAR/QUIET NIGHT WITH TERRIFIC RADIATIONAL COOLING CONDITIONS YET AGAIN. AFTERNOON CROSSOVER TEMPS WILL LIKELY BE IN THE LOWER-MIDDLE TEENS...SO LOWS SHOULD HAVE NO PROBLEM FALLING INTO THE MIDDLE-UPPER TEENS IN THE COLD SPOTS YET AGAIN WITH LOWS GENERALLY IN THE LOWER 20S ELSEWHERE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 AM EDT FRI MAR 29 2013 SATURDAY...AS THE SFC HIGH MOVES EAST, THE COLD FRONT FROM THE WEST BEARS DOWN ON THE FORECAST AREA. AIDING THE COLD FRONT IS THE 500 MB SHORTWAVE TROUGH THAT IS CHASING THE RIDGE EAST AS WELL. THE MORNING LOOKS TO REMAIN DRY AS THE MOISTURE AT 850 MB AND IN THE 700-500 MB LAYER TAKES UNTIL AROUND 18Z TO BEGIN GETTING MOIST ENOUGH TO SUPPORT PRECIPITATION. THE PROFILE WOULD SUGGEST THAT THE PRECIPITATION WOULD BE ALL RAIN THROUGH 00Z. SATURDAY NIGHT...MOISTURE CONTINUES OVER THE REGION AND THE PROFILES BEGIN TO MOVE TOWARD 0C SO THAT THERE WILL BE A MIX IN E UPPER AND PROBABLY RAIN IN N LOWER. THE PROFILES DON`T CHANGE MUCH OVERNIGHT SO THAT A MIX IS WHAT WILL BE EXPECTED. ALSO, THE 700-500 MB LAYER BEGINS TO DRY OUT SIGNIFICANTLY ENOUGH THAT IT MAY STOP PRECIPITATING. SO WILL GO WITH THE CHANCE POPS IN E UPPER AND OVER LAKE MICHIGAN. STILL LOTS OF MOISTURE OVER N LOWER AND LAKE HURON TO CONTINUE THE LIKELY POPS. SUNDAY...THE MOISTURE CONTINUES TO MOVE EAST, WITH COLD AIR SPILLING INTO THE FORECAST AREA. AS THE COLD AIR MOVES IN THE MOISTURE BEGINS TO MOVE INTO THE REGION WITH SATURATION REACHING -10C. THIS GETS THE LIGHT SNOW/FLURRIES STARTED AS THE STABILITY BEGINS TO DECREASE AND UNDER THE 500 MB LOW AND SHORTWAVES ROTATING AROUND IT. OVERNIGHT, THE 850 MB TEMPERATURES FALL TO AROUND -13C ON THE ECMWF BY 12Z. THE GFS IS SIGNIFICANTLY COLDER (-17C) AND WOULD PRODUCE LES FAIRLY WELL WITH THE 500 MB LOW. WILL HEDGE PESSIMISTIC AS THIS SEASON HAS REMAINED COLDER THAN FIRST THOUGHT. EXTENDED (MONDAY THROUGH THURSDAY)...MONDAY, LOOKS LIKE THE TEMPERATURES FALL ENOUGH TO HAVE LES ON BOTH MODELS AS THE ECMWF HAS -14C AT 850 MB BY 00Z. EARLIER IN THE WEEK, THE WINDS LOOKED STRONGER, NOW IT LOOKS BREEZY. WILL CONTINUE THE GUSTY WINDS IN THE HWO. TUESDAY, AS THE SFC HIGH BEGINS TO MOVE INTO THE REGION, THE 850 MB TEMPERATURES BEGIN TO WARM SLIGHTLY, JUST ENOUGH THAT WE MAY LOSE THE INSTABILITY NEEDED FOR THE LES. THIS CONTINUES INTO THE NIGHT SO WOULD EXPECT THAT THE SNOW WOULD STOP. 00Z ECMWF SAYS THAT IT SHOULD. WEDNESDAY, HIGH PRESSURE AT THE SFC AND 500 MB RIDGE MOVES THROUGH THE REGION SO THAT WE WILL REMAIN DRY FOR THE DAY. OVERNIGHT, THE ANOTHER COLD FRONT AND 500 MB SHORTWAVE TROUGH MOVE THROUGH THE REGION. ONE SOLUTION IS WARM ENOUGH FOR RAIN AND ONE COLD ENOUGH FOR SNOW. SO WILL GO WITH A MIX AT THIS POINT. THURSDAY, THINK THAT THE GFS IS A LITTLE TOO WET AT 850 MB AND THINK THAT THE THE ECMWF HAS THE RIGHT IDEA, THAT IS IT IS IN LINE WITH THE CURRENT FORECAST SO WILL CONTINUE THE DRY DAY AND NIGHT AT HIGH PRESSURE BEGINS TO BUILD INTO THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 638 AM EDT FRI MAR 29 2013 SUMMARY: HIGH PRESSURE CENTERED JUST WEST OF THE WESTERN GREAT LAKES WILL SHIFT EAST...MOVING OVERHEAD THROUGH MOST OF THE UPCOMING TAF PERIOD...ALLOWING FOR CONTINUED GOOD FLYING CONDITIONS. RESTRICTIONS: NONE EXPECTED THROUGH THE TAF PERIOD. CONFIDENCE HIGH. WINDS: CALM WINDS WILL BECOME NORTHWEST 5-10KTS BY MID-LATE MORNING AND THROUGH THE AFTERNOON BEFORE RETURNING TO CALM TONIGHT. A LAKE BREEZE MAY CAUSE THESE NORTHWEST WINDS TO DIE OFF/SHIFT WEAK SOUTHEAST AT APN BY MID/LATE AFTERNOON. && .MARINE... ISSUED AT 329 AM EDT FRI MAR 29 2013 SUMMARY: HIGH PRESSURE WILL REMAIN IN CONTROL OF THE REGION/S WEATHER THROUGH SATURDAY WITH QUIET CONDITIONS OVER THE LAKES. A COLD FRONT WILL APPROACH SUNDAY...BRINGING STRENGTHENING SOUTHERLY WINDS. IN IT/S WAKE...NORTHWEST WINDS WILL DEVELOP AND STRENGTHEN SUNDAY NIGHT INTO MONDAY WITH STRONG WINDS CONTINUING THROUGH TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION FROM THE WEST. HEADLINE POTENTIAL: SMALL CRAFT POTENTIAL UNDER SOUTHERLY FLOW SATURDAY WITH A PROLONGED PERIOD OF SMALL CRAFT WINDS DEVELOPING BEHIND A STRONG COLD FRONT SUNDAY NIGHT AND CONTINUING THROUGH NEXT TUESDAY. THERE IS SOME POTENTIAL FOR LOW-END GALE FORCE WINDS IN THE MONDAY-TUESDAY TIMEFRAME FOR NW FLOW FAVORED AREAS /NEAR WHITEFISH POINT AND ALONG THE LAKE HURON COAST FROM THE BRIDGE SOUTHEAST TO PRESQUE ISLE LIGHT/. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...JZ SYNOPSIS...JL SHORT TERM...ARNOTT LONG TERM...JL AVIATION...ARNOTT MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS GAYLORD MI
639 AM EDT FRI MAR 29 2013 .SYNOPSIS... ISSUED AT 329 AM EDT FRI MAR 29 2013 HIGH PRESSURE WILL ADVANCE FROM THE UPPER MIDWEST THROUGH THE GREAT LAKES TO ROUND OUT TODAY. THIS PATTERN WILL BRING SUNSHINE THROUGH THE FIRST HALF OF SATURDAY. TEMPERATURES WILL ALSO FINALLY...ALTHOUGH BRIEFLY...WARM ABOVE NORMAL FOR THE FIRST HALF OF THE WEEKEND. THAT TREND WILL BE SHORT LIVED...AS A STRONG COLD FRONT ARRIVES SATURDAY NIGHT...WITH A ROUND OF RAIN OR SNOW SHOWERS LIKELY. AS THE FRONT PASSES...MUCH COLDER WEATHER WILL ARRIVE LATER SUNDAY AND STICK AROUND THROUGH AT LEAST TUESDAY...WITH PERIODIC LAKE EFFECT SNOW SHOWERS AND WINDY CONDITIONS. && .UPDATE... ISSUED AT 613 AM EDT FRI MAR 29 2013 CHANGES THIS HOUR: COULDN/T QUITE GET THROUGH THE OVERNIGHT WITHOUT DEALING WITH SOME STRATUS. A PATCH HAS POPPED UP OVER THE PAST HOUR FROM KANJ NORTH INTO THE HIGH TERRAIN EAST OF WHITEFISH BAY ACROSS THE BORDER IN ONTARIO. NEAR TERM RUC PROGS SUGGEST THAT SOMEWHAT ENHANCED H9 MOISTURE FROM THIS AREA EAST WILL MOVE EAST AND AWAY FROM THE REGION THIS MORNING. DON/T EXPECT THIS TO GET TOO OUT OF HAND/WIDESPREAD...BUT WILL CARRY SOME ADDITIONAL CLOUDINESS THROUGH THE NEXT FEW HOURS AS EARLY MORNING INVERSION WILL ALLOW ANYTHING THAT DEVELOPS TO PERSIST FOR A TIME. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 329 AM EDT FRI MAR 29 2013 HIGH IMPACT WEATHER POTENTIAL: NONE. OVERVIEW: EARLY MORNING WATER VAPOR IMAGERY REVEALS RECENT BLOCKING OVER EASTERN CANADA RETREATING EAST AS BROAD NORTHWEST FLOW BEGINS TO TAKE OVER ALOFT ACROSS THE GREAT LAKES REGION. THE CLOSED HIGH ASSOCIATED WITH THIS BLOCK HAS OPENED UP...AND WAS OVERHEAD AS SHORTWAVE RIDGING YESTERDAY AND HAS NOW PUSHED INTO THE NORTHEASTERN CONUS AS OF THIS MORNING. MOVING DOWN TO THE SURFACE...A MODEST SURFACE RIDGE AXIS IS DRAPED FROM JUST WEST OF THE WESTERN LAKES INTO INDIANA/KENTUCKY...WHICH HAS PROVIDED CALM/QUIET WEATHER ACROSS THE GREAT LAKES REGION. 00Z APX RAOB SHOWED -4C AT H8...JUST ABOUT NORMAL FOR THIS TIME OF YEAR WITH OUR AVERAGE TEMPERATURE FOR THE DATE YESTERDAY SIMILARLY CLOSE TO NORMAL. WITH THIS HIGH OVERHEAD AND THE MAJORITY OF ANY JET ENERGY RESIDING OVER THE SOUTHEASTERN STATES...THE WEATHER LOOKS QUIET THROUGH THE SHORT TERM PORTION OF THE FORECAST...BUT THE AFOREMENTIONED BREAKING DOWN OF THE BLOCK OVER CANADA PORTENDS THAT THIS QUIET STRETCH OF WEATHER WILL BE COMING TO AN END SOON...SO DON/T GET USED TO WHAT YOU SEE TODAY! THROUGH DAYBREAK: TERRIFIC RADIATIONAL COOLING CONDITIONS ALLOWING SOME SPOTS TO REACH 20F AS OF THIS WRITING...WITH A WEAK WIND KEEPING SOME HIGHER TERRAIN SPOTS AS WELL AS THE NE LOWER COAST IN THE UPPER 20S TO AROUND 30 UNDER CLEAR SKIES. LITTLE CHANGE THROUGH DAYBREAK...WITH SOME LOCAL SLICK SPOTS LIKELY AS AFTERNOON PUDDLES REFREEZE. TODAY: WEAK SHORTWAVE TROUGH NOW EXITING TO THE SOUTHEAST OF THE REGION WILL ALLOW FOR GRADUALLY BUILDING MID LEVEL HEIGHTS /ALONG WITH MID LEVEL NVA/ TODAY WITH THE RIDGE OF SURFACE HIGH PRESSURE SLIDING EAST INTO THE REGION. LLEVEL TRAJECTORIES SHOW TODAY/S AIRMASS ARRIVING FROM WESTERN ONTARIO 24 HOURS PREVIOUSLY...AND A LOOK AT YESTERDAY/S CONDITIONS THERE SHOW NO CUMULUS DEVELOPMENT /DEWPOINTS FALLING INTO THE LOWER-MID TEENS/ ALONG WITH LOWER 40S FOR HIGHS. GIVEN THE OVERHEAD HIGH PRESSURE AND NVA...WILL ALLOW FOR SOME WARMING TO THIS AIRMASS THROUGH SUBSIDENCE WHICH SUGGESTS TRENDING TOWARDS THE WARMER ECMWF-MOS GUIDANCE TODAY...YIELDING HIGHS IN THE MID-UPPER 40S MOST LOCATIONS UNDER SUNNY SKIES... WARMEST SOUTHEASTERN AREAS WHERE LAKE INFLUENCE ON TEMPS WILL BE LESS. TONIGHT: HIGH PRESSURE SETTLES OVERHEAD WITH SHORT-WAVE RIDGING CONTINUING/SHARPENING AT MID LEVELS IN RESPONSE TO OUR NEXT WEATHER MAKER DROPPING SOUTH OUT OF CENTRAL CANADA. THIS WILL LIKELY SPREAD SOME HIGH CLOUDINESS INTO THE REGION AFTER MIDNIGHT...BUT FOR THE MOST PART EXPECT ANOTHER CALM/CLEAR/QUIET NIGHT WITH TERRIFIC RADIATIONAL COOLING CONDITIONS YET AGAIN. AFTERNOON CROSSOVER TEMPS WILL LIKELY BE IN THE LOWER-MIDDLE TEENS...SO LOWS SHOULD HAVE NO PROBLEM FALLING INTO THE MIDDLE-UPPER TEENS IN THE COLD SPOTS YET AGAIN WITH LOWS GENERALLY IN THE LOWER 20S ELSEWHERE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 AM EDT FRI MAR 29 2013 SATURDAY...AS THE SFC HIGH MOVES EAST, THE COLD FRONT FROM THE WEST BEARS DOWN ON THE FORECAST AREA. AIDING THE COLD FRONT IS THE 500 MB SHORTWAVE TROUGH THAT IS CHASING THE RIDGE EAST AS WELL. THE MORNING LOOKS TO REMAIN DRY AS THE MOISTURE AT 850 MB AND IN THE 700-500 MB LAYER TAKES UNTIL AROUND 18Z TO BEGIN GETTING MOIST ENOUGH TO SUPPORT PRECIPITATION. THE PROFILE WOULD SUGGEST THAT THE PRECIPITATION WOULD BE ALL RAIN THROUGH 00Z. SATURDAY NIGHT...MOISTURE CONTINUES OVER THE REGION AND THE PROFILES BEGIN TO MOVE TOWARD 0C SO THAT THERE WILL BE A MIX IN E UPPER AND PROBABLY RAIN IN N LOWER. THE PROFILES DON`T CHANGE MUCH OVERNIGHT SO THAT A MIX IS WHAT WILL BE EXPECTED. ALSO, THE 700-500 MB LAYER BEGINS TO DRY OUT SIGNIFICANTLY ENOUGH THAT IT MAY STOP PRECIPITATING. SO WILL GO WITH THE CHANCE POPS IN E UPPER AND OVER LAKE MICHIGAN. STILL LOTS OF MOISTURE OVER N LOWER AND LAKE HURON TO CONTINUE THE LIKELY POPS. SUNDAY...THE MOISTURE CONTINUES TO MOVE EAST, WITH COLD AIR SPILLING INTO THE FORECAST AREA. AS THE COLD AIR MOVES IN THE MOISTURE BEGINS TO MOVE INTO THE REGION WITH SATURATION REACHING -10C. THIS GETS THE LIGHT SNOW/FLURRIES STARTED AS THE STABILITY BEGINS TO DECREASE AND UNDER THE 500 MB LOW AND SHORTWAVES ROTATING AROUND IT. OVERNIGHT, THE 850 MB TEMPERATURES FALL TO AROUND -13C ON THE ECMWF BY 12Z. THE GFS IS SIGNIFICANTLY COLDER (-17C) AND WOULD PRODUCE LES FAIRLY WELL WITH THE 500 MB LOW. WILL HEDGE PESSIMISTIC AS THIS SEASON HAS REMAINED COLDER THAN FIRST THOUGHT. EXTENDED (MONDAY THROUGH THURSDAY)...MONDAY, LOOKS LIKE THE TEMPERATURES FALL ENOUGH TO HAVE LES ON BOTH MODELS AS THE ECMWF HAS -14C AT 850 MB BY 00Z. EARLIER IN THE WEEK, THE WINDS LOOKED STRONGER, NOW IT LOOKS BREEZY. WILL CONTINUE THE GUSTY WINDS IN THE HWO. TUESDAY, AS THE SFC HIGH BEGINS TO MOVE INTO THE REGION, THE 850 MB TEMPERATURES BEGIN TO WARM SLIGHTLY, JUST ENOUGH THAT WE MAY LOSE THE INSTABILITY NEEDED FOR THE LES. THIS CONTINUES INTO THE NIGHT SO WOULD EXPECT THAT THE SNOW WOULD STOP. 00Z ECMWF SAYS THAT IT SHOULD. WEDNESDAY, HIGH PRESSURE AT THE SFC AND 500 MB RIDGE MOVES THROUGH THE REGION SO THAT WE WILL REMAIN DRY FOR THE DAY. OVERNIGHT, THE ANOTHER COLD FRONT AND 500 MB SHORTWAVE TROUGH MOVE THROUGH THE REGION. ONE SOLUTION IS WARM ENOUGH FOR RAIN AND ONE COLD ENOUGH FOR SNOW. SO WILL GO WITH A MIX AT THIS POINT. THURSDAY, THINK THAT THE GFS IS A LITTLE TOO WET AT 850 MB AND THINK THAT THE THE ECMWF HAS THE RIGHT IDEA, THAT IS IT IS IN LINE WITH THE CURRENT FORECAST SO WILL CONTINUE THE DRY DAY AND NIGHT AT HIGH PRESSURE BEGINS TO BUILD INTO THE REGION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 638 AM EDT FRI MAR 29 2013 SUMMARY: HIGH PRESSURE CENTERED JUST WEST OF THE WESTERN GREAT LAKES WILL SHIFT EAST...MOVING OVERHEAD THROUGH MOST OF THE UPCOMING TAF PERIOD...ALLOWING FOR CONTINUED GOOD FLYING CONDITIONS. RESTRICTIONS: NONE EXPECTED THROUGH THE TAF PERIOD. CONFIDENCE HIGH. WINDS: CALM WINDS WILL BECOME NORTHWEST 5-10KTS BY MID-LATE MORNING AND THROUGH THE AFTERNOON BEFORE RETURNING TO CALM TONIGHT. A LAKE BREEZE MAY CAUSE THESE NORTHWEST WINDS TO DIE OFF/SHIFT WEAK SOUTHEAST AT APN BY MID/LATE AFTERNOON. && .MARINE... ISSUED AT 329 AM EDT FRI MAR 29 2013 SUMMARY: HIGH PRESSURE WILL REMAIN IN CONTROL OF THE REGION/S WEATHER THROUGH SATURDAY WITH QUIET CONDITIONS OVER THE LAKES. A COLD FRONT WILL APPROACH SUNDAY...BRINGING STRENGTHENING SOUTHERLY WINDS. IN IT/S WAKE...NORTHWEST WINDS WILL DEVELOP AND STRENGTHEN SUNDAY NIGHT INTO MONDAY WITH STRONG WINDS CONTINUING THROUGH TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION FROM THE WEST. HEADLINE POTENTIAL: SMALL CRAFT POTENTIAL UNDER SOUTHERLY FLOW SATURDAY WITH A PROLONGED PERIOD OF SMALL CRAFT WINDS DEVELOPING BEHIND A STRONG COLD FRONT SUNDAY NIGHT AND CONTINUING THROUGH NEXT TUESDAY. THERE IS SOME POTENTIAL FOR LOW-END GALE FORCE WINDS IN THE MONDAY-TUESDAY TIMEFRAME FOR NW FLOW FAVORED AREAS /NEAR WHITEFISH POINT AND ALONG THE LAKE HURON COAST FROM THE BRIDGE SOUTHEAST TO PRESQUE ISLE LIGHT/. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...ARNOTT SYNOPSIS...JL SHORT TERM...ARNOTT LONG TERM...JL AVIATION...ARNOTT MARINE...ARNOTT
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
619 AM EDT FRI MAR 29 2013 .SYNOPSIS... ISSUED AT 329 AM EDT FRI MAR 29 2013 HIGH PRESSURE WILL ADVANCE FROM THE UPPER MIDWEST THROUGH THE GREAT LAKES TO ROUND OUT TODAY. THIS PATTERN WILL BRING SUNSHINE THROUGH THE FIRST HALF OF SATURDAY. TEMPERATURES WILL ALSO FINALLY...ALTHOUGH BRIEFLY...WARM ABOVE NORMAL FOR THE FIRST HALF OF THE WEEKEND. THAT TREND WILL BE SHORT LIVED...AS A STRONG COLD FRONT ARRIVES SATURDAY NIGHT...WITH A ROUND OF RAIN OR SNOW SHOWERS LIKELY. AS THE FRONT PASSES...MUCH COLDER WEATHER WILL ARRIVE LATER SUNDAY AND STICK AROUND THROUGH AT LEAST TUESDAY...WITH PERIODIC LAKE EFFECT SNOW SHOWERS AND WINDY CONDITIONS. && .UPDATE... ISSUED AT 613 AM EDT FRI MAR 29 2013 CHANGES THIS HOUR: COULDN/T QUITE GET THROUGH THE OVERNIGHT WITHOUT DEALING WITH SOME STRATUS. A PATCH HAS POPPED UP OVER THE PAST HOUR FROM KANJ NORTH INTO THE HIGH TERRAIN EAST OF WHITEFISH BAY ACROSS THE BORDER IN ONTARIO. NEAR TERM RUC PROGS SUGGEST THAT SOMEWHAT ENHANCED H9 MOISTURE FROM THIS AREA EAST WILL MOVE EAST AND AWAY FROM THE REGION THIS MORNING. DON/T EXPECT THIS TO GET TOO OUT OF HAND/WIDESPREAD...BUT WILL CARRY SOME ADDITIONAL CLOUDINESS THROUGH THE NEXT FEW HOURS AS EARLY MORNING INVERSION WILL ALLOW ANYTHING THAT DEVELOPS TO PERSIST FOR A TIME. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 329 AM EDT FRI MAR 29 2013 HIGH IMPACT WEATHER POTENTIAL: NONE. OVERVIEW: EARLY MORNING WATER VAPOR IMAGERY REVEALS RECENT BLOCKING OVER EASTERN CANADA RETREATING EAST AS BROAD NORTHWEST FLOW BEGINS TO TAKE OVER ALOFT ACROSS THE GREAT LAKES REGION. THE CLOSED HIGH ASSOCIATED WITH THIS BLOCK HAS OPENED UP...AND WAS OVERHEAD AS SHORTWAVE RIDGING YESTERDAY AND HAS NOW PUSHED INTO THE NORTHEASTERN CONUS AS OF THIS MORNING. MOVING DOWN TO THE SURFACE...A MODEST SURFACE RIDGE AXIS IS DRAPED FROM JUST WEST OF THE WESTERN LAKES INTO INDIANA/KENTUCKY...WHICH HAS PROVIDED CALM/QUIET WEATHER ACROSS THE GREAT LAKES REGION. 00Z APX RAOB SHOWED -4C AT H8...JUST ABOUT NORMAL FOR THIS TIME OF YEAR WITH OUR AVERAGE TEMPERATURE FOR THE DATE YESTERDAY SIMILARLY CLOSE TO NORMAL. WITH THIS HIGH OVERHEAD AND THE MAJORITY OF ANY JET ENERGY RESIDING OVER THE SOUTHEASTERN STATES...THE WEATHER LOOKS QUIET THROUGH THE SHORT TERM PORTION OF THE FORECAST...BUT THE AFOREMENTIONED BREAKING DOWN OF THE BLOCK OVER CANADA PORTENDS THAT THIS QUIET STRETCH OF WEATHER WILL BE COMING TO AN END SOON...SO DON/T GET USED TO WHAT YOU SEE TODAY! THROUGH DAYBREAK: TERRIFIC RADIATIONAL COOLING CONDITIONS ALLOWING SOME SPOTS TO REACH 20F AS OF THIS WRITING...WITH A WEAK WIND KEEPING SOME HIGHER TERRAIN SPOTS AS WELL AS THE NE LOWER COAST IN THE UPPER 20S TO AROUND 30 UNDER CLEAR SKIES. LITTLE CHANGE THROUGH DAYBREAK...WITH SOME LOCAL SLICK SPOTS LIKELY AS AFTERNOON PUDDLES REFREEZE. TODAY: WEAK SHORTWAVE TROUGH NOW EXITING TO THE SOUTHEAST OF THE REGION WILL ALLOW FOR GRADUALLY BUILDING MID LEVEL HEIGHTS /ALONG WITH MID LEVEL NVA/ TODAY WITH THE RIDGE OF SURFACE HIGH PRESSURE SLIDING EAST INTO THE REGION. LLEVEL TRAJECTORIES SHOW TODAY/S AIRMASS ARRIVING FROM WESTERN ONTARIO 24 HOURS PREVIOUSLY...AND A LOOK AT YESTERDAY/S CONDITIONS THERE SHOW NO CUMULUS DEVELOPMENT /DEWPOINTS FALLING INTO THE LOWER-MID TEENS/ ALONG WITH LOWER 40S FOR HIGHS. GIVEN THE OVERHEAD HIGH PRESSURE AND NVA...WILL ALLOW FOR SOME WARMING TO THIS AIRMASS THROUGH SUBSIDENCE WHICH SUGGESTS TRENDING TOWARDS THE WARMER ECMWF-MOS GUIDANCE TODAY...YIELDING HIGHS IN THE MID-UPPER 40S MOST LOCATIONS UNDER SUNNY SKIES... WARMEST SOUTHEASTERN AREAS WHERE LAKE INFLUENCE ON TEMPS WILL BE LESS. TONIGHT: HIGH PRESSURE SETTLES OVERHEAD WITH SHORT-WAVE RIDGING CONTINUING/SHARPENING AT MID LEVELS IN RESPONSE TO OUR NEXT WEATHER MAKER DROPPING SOUTH OUT OF CENTRAL CANADA. THIS WILL LIKELY SPREAD SOME HIGH CLOUDINESS INTO THE REGION AFTER MIDNIGHT...BUT FOR THE MOST PART EXPECT ANOTHER CALM/CLEAR/QUIET NIGHT WITH TERRIFIC RADIATIONAL COOLING CONDITIONS YET AGAIN. AFTERNOON CROSSOVER TEMPS WILL LIKELY BE IN THE LOWER-MIDDLE TEENS...SO LOWS SHOULD HAVE NO PROBLEM FALLING INTO THE MIDDLE-UPPER TEENS IN THE COLD SPOTS YET AGAIN WITH LOWS GENERALLY IN THE LOWER 20S ELSEWHERE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 AM EDT FRI MAR 29 2013 SATURDAY...AS THE SFC HIGH MOVES EAST, THE COLD FRONT FROM THE WEST BEARS DOWN ON THE FORECAST AREA. AIDING THE COLD FRONT IS THE 500 MB SHORTWAVE TROUGH THAT IS CHASING THE RIDGE EAST AS WELL. THE MORNING LOOKS TO REMAIN DRY AS THE MOISTURE AT 850 MB AND IN THE 700-500 MB LAYER TAKES UNTIL AROUND 18Z TO BEGIN GETTING MOIST ENOUGH TO SUPPORT PRECIPITATION. THE PROFILE WOULD SUGGEST THAT THE PRECIPITATION WOULD BE ALL RAIN THROUGH 00Z. SATURDAY NIGHT...MOISTURE CONTINUES OVER THE REGION AND THE PROFILES BEGIN TO MOVE TOWARD 0C SO THAT THERE WILL BE A MIX IN E UPPER AND PROBABLY RAIN IN N LOWER. THE PROFILES DON`T CHANGE MUCH OVERNIGHT SO THAT A MIX IS WHAT WILL BE EXPECTED. ALSO, THE 700-500 MB LAYER BEGINS TO DRY OUT SIGNIFICANTLY ENOUGH THAT IT MAY STOP PRECIPITATING. SO WILL GO WITH THE CHANCE POPS IN E UPPER AND OVER LAKE MICHIGAN. STILL LOTS OF MOISTURE OVER N LOWER AND LAKE HURON TO CONTINUE THE LIKELY POPS. SUNDAY...THE MOISTURE CONTINUES TO MOVE EAST, WITH COLD AIR SPILLING INTO THE FORECAST AREA. AS THE COLD AIR MOVES IN THE MOISTURE BEGINS TO MOVE INTO THE REGION WITH SATURATION REACHING -10C. THIS GETS THE LIGHT SNOW/FLURRIES STARTED AS THE STABILITY BEGINS TO DECREASE AND UNDER THE 500 MB LOW AND SHORTWAVES ROTATING AROUND IT. OVERNIGHT, THE 850 MB TEMPERATURES FALL TO AROUND -13C ON THE ECMWF BY 12Z. THE GFS IS SIGNIFICANTLY COLDER (-17C) AND WOULD PRODUCE LES FAIRLY WELL WITH THE 500 MB LOW. WILL HEDGE PESSIMISTIC AS THIS SEASON HAS REMAINED COLDER THAN FIRST THOUGHT. EXTENDED (MONDAY THROUGH THURSDAY)...MONDAY, LOOKS LIKE THE TEMPERATURES FALL ENOUGH TO HAVE LES ON BOTH MODELS AS THE ECMWF HAS -14C AT 850 MB BY 00Z. EARLIER IN THE WEEK, THE WINDS LOOKED STRONGER, NOW IT LOOKS BREEZY. WILL CONTINUE THE GUSTY WINDS IN THE HWO. TUESDAY, AS THE SFC HIGH BEGINS TO MOVE INTO THE REGION, THE 850 MB TEMPERATURES BEGIN TO WARM SLIGHTLY, JUST ENOUGH THAT WE MAY LOSE THE INSTABILITY NEEDED FOR THE LES. THIS CONTINUES INTO THE NIGHT SO WOULD EXPECT THAT THE SNOW WOULD STOP. 00Z ECMWF SAYS THAT IT SHOULD. WEDNESDAY, HIGH PRESSURE AT THE SFC AND 500 MB RIDGE MOVES THROUGH THE REGION SO THAT WE WILL REMAIN DRY FOR THE DAY. OVERNIGHT, THE ANOTHER COLD FRONT AND 500 MB SHORTWAVE TROUGH MOVE THROUGH THE REGION. ONE SOLUTION IS WARM ENOUGH FOR RAIN AND ONE COLD ENOUGH FOR SNOW. SO WILL GO WITH A MIX AT THIS POINT. THURSDAY, THINK THAT THE GFS IS A LITTLE TOO WET AT 850 MB AND THINK THAT THE THE ECMWF HAS THE RIGHT IDEA, THAT IS IT IS IN LINE WITH THE CURRENT FORECAST SO WILL CONTINUE THE DRY DAY AND NIGHT AT HIGH PRESSURE BEGINS TO BUILD INTO THE REGION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 129 AM EDT FRI MAR 29 2013 SUMMARY: HIGH PRESSURE JUST WEST OF THE GREAT LAKES REGION WILL PUSH OVERHEAD BRINGING VERY QUIET CONDITIONS THROUGH THE UPCOMING TAF PERIOD. OUTSIDE OF A FEW HIGH CLOUDS...EXPECT CLEAR SKIES THROUGH THE TAF PERIOD. RESTRICTIONS: NONE EXPECTED THROUGH THE TAF PERIOD. CONFIDENCE HIGH. WINDS: CALM WINDS THROUGH DAYBREAK WILL BECOME NORTHWEST 5-10KTS BY MID-LATE MORNING AND THROUGH THE AFTERNOON BEFORE RETURNING TO CALM FRIDAY NIGHT. A LAKE BREEZE MAY CAUSE THESE NORTHWEST WINDS TO DIE OFF/SHIFT WEAK SOUTHEAST AT APN BY MID/LATE AFTERNOON. && .MARINE... ISSUED AT 329 AM EDT FRI MAR 29 2013 SUMMARY: HIGH PRESSURE WILL REMAIN IN CONTROL OF THE REGION/S WEATHER THROUGH SATURDAY WITH QUIET CONDITIONS OVER THE LAKES. A COLD FRONT WILL APPROACH SUNDAY...BRINGING STRENGTHENING SOUTHERLY WINDS. IN IT/S WAKE...NORTHWEST WINDS WILL DEVELOP AND STRENGTHEN SUNDAY NIGHT INTO MONDAY WITH STRONG WINDS CONTINUING THROUGH TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION FROM THE WEST. HEADLINE POTENTIAL: SMALL CRAFT POTENTIAL UNDER SOUTHERLY FLOW SATURDAY WITH A PROLONGED PERIOD OF SMALL CRAFT WINDS DEVELOPING BEHIND A STRONG COLD FRONT SUNDAY NIGHT AND CONTINUING THROUGH NEXT TUESDAY. THERE IS SOME POTENTIAL FOR LOW-END GALE FORCE WINDS IN THE MONDAY-TUESDAY TIMEFRAME FOR NW FLOW FAVORED AREAS /NEAR WHITEFISH POINT AND ALONG THE LAKE HURON COAST FROM THE BRIDGE SOUTHEAST TO PRESQUE ISLE LIGHT/. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...ARNOTT SYNOPSIS...JL SHORT TERM...ARNOTT LONG TERM...JL AVIATION...ARNOTT MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
628 AM CDT FRI MAR 29 2013 .AVIATION... 12Z TAFS FOR KOMA...KLNK...KOFK. VFR CONDITIONS EXPECTED THROUGH 03Z THEN CONDITIONS EXPECTED TO DETERIORATE FOR THE REMAINDER OF THE PERIOD AS APPROACHING COLD FRONT BRINGS SCATTERED SHOWERS AND THUNDERSTORMS INTO THE AREA WITH MVFR CIGS AND VSBYS. && .PREV DISCUSSION... /ISSUED 340 AM CDT FRI MAR 29 2013/ SHORT TERM...TODAY THROUGH SATURDAY NIGHT. THE MAIN FORECAST CONCERNS IN THIS PERIOD ARE CHANCES FOR SHOWERS/ THUNDERSTORMS AND TEMPERATURES. TEMPERATURES YESTERDAY TOPPED OUT MAINLY IN THE UPPER 50S AND LOWER 60S ACROSS THE FORECAST AREA. HIGHS TODAY SHOULD BE ABOUT 3 TO 5 DEGREES WARMER...BASED ON A SMALL INCREASE IN 850 MB TEMPS. THERE IS SOME CONCERN THAT PCPN COULD DEVELOP LATE THIS AFTERNOON AS LOW LEVEL MOISTURE AND INSTABILITY INCREASE. BUT BASED ON MOST RECENT FORECASTS OF MOST UNSTABLE CAPE FORECASTS FROM RAP MODEL...KEPT THINGS DRY UNTIL THIS EVENING. 850 MB DEWPOINTS WERE IN THE 5 TO 10 DEGREE CELSIUS RANGE LAST EVENING ACROSS THE SOUTHERN PLAINS... MAINLY FROM OKLAHOMA SOUTH. MODEL SHOW MOISTURE INCREASING IN OUR AREA...BUT MAIN AXIS STAYS MAINLY TO OUR WEST IN CENTRAL NEBRASKA THROUGH 00Z THIS EVENING. THIS 850 MB MOISTURE SHOULD SPREAD OVER OUR AREA TONIGHT AND THEN OUT OF THE AREA SATURDAY. KEPT FAIRLY HIGH POPS GOING FOR TONIGHT AND SATURDAY MORNING. SOME OF THE MODEL QPFS LOOK A LITTLE HIGH...BUT CERTAINLY AMOUNTS BETWEEN A TENTH AND A QUARTER OF AN INCH SEEM REASONABLE...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. COMBINATION OF CLOUD COVER AND WIND SHOULD HELP KEEP LOWS TONIGHT IN THE 40S MOST SPOTS. ON SATURDAY...A WIND SHIFT WILL MOVE ACROSS THE AREA...BUT 850 MB TEMPERATURES DO NOT CHANGE MUCH AND MIXING SHOULD BE GOOD. STAYED FAIRLY CLOSE TO PREVIOUS FORECAST FOR HIGHS SATURDAY...RANGING FROM UPPER 50S NORTH TO MID OR UPPER 60S FAR SOUTH. IF CLOUDS AND PCPN CLEAR OUT FASTER THAN CURRENTLY EXPECTED...HIGHS COULD BE A LITTLE WARMER NORTHERN AND CENTRAL ZONES. SATURDAY NIGHT WE ARE BETWEEN SYSTEMS AND FOR NOW KEPT THINGS DRY. SOME SHOWERS COULD DEVELOP TO OUR WEST IN THE AFTERNOON BUT FOR NOW EXPECTED THESE TO DISSIPATE SATURDAY EVENING BEFORE REACHING SOUTHEAST NEBRASKA. LOWS WILL DROP INTO THE 30S SATURDAY NIGHT. MILLER LONG TERM...SUNDAY THROUGH THURSDAY. MAIN CONCERNS IN THIS PERIOD ARE TEMPERATURES SUNDAY AND PCPN CHANCES FOR SUNDAY INTO SUNDAY NIGHT. A STRONG COLD FRONT WILL BE PUSHING INTO OUR NORTHERN ZONES SUNDAY AFTERNOON...SO JUST HOW WARM IT WILL GET IS PROBLEMATIC. AIRMASS WILL BE STARTING OUT QUITE MILD...BUT TEMPERATURES SHOULD BE FALLING IN THE AFTERNOON ACROSS NORTHEAST NEBRASKA AS WINDS SHIFT TO THE NORTH. WENT WITH HIGHS CLOSE TO NOON NORTH IN THE 50S...BUT IN THE 60S MID OR LATE AFTERNOON SOUTH. BUT AGAIN THIS WILL DEPEND ON FRONTAL TIMING. AREAS ALONG THE KANSAS BORDER COULD APPROACH 70...BUT DID NOT WANT TO GET TOO OPTIMISTIC AT THIS POINT. FAIRLY DECENT FORCING IS EXPECTED ALONG AND BEHIND THE FRONT...SO KEPT POPS 20 TO 30 PERCENT MOST AREAS SUNDAY AFTERNOON. PCPN TYPE WILL BE AN ISSUE AS THE COLD AIR POURS IN FOR SUNDAY NIGHT...WITH RAIN CHANGING TO SNOW. TRIED TO ADD SOME DETAIL TO PCPN TYPE SUNDAY NIGHT BUT THIS WILL BE REFINED AS WE GET CLOSER. DID NOT MENTION ANY SNOW ACCUMULATION AT THIS POINT...BUT THAT WILL NEED TO BE MONITORED CLOSELY. HIGHS MONDAY SHOULD ONLY REACH THE 30S...BUT THEN LOOK FOR MODERATING TEMPERATURES THROUGH THURSDAY AS MILDER AIR MOVES IN FROM THE SOUTH AND WEST. MILLER && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ FOBERT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
956 AM EDT FRI MAR 29 2013 .SYNOPSIS... HIGH PRESSURE WILL MOVE ACROSS THE REGION TODAY AND OFF THE SOUTHEAST COAST SATURDAY. AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE WEST LATE TODAY...MOVING THROUGH THE REGION OVERNIGHT AND EARLY SATURDAY. A FRONTAL SYSTEM WILL APPROACH FROM THE WEST LATE SATURDAY AND MOVE SLOWLY THROUGH THE AREA SUNDAY. && .NEAR TERM /THROUGH SATURDAY/... AS OF 955 AM FRIDAY... THROUGH TONIGHT: THE LATEST SURFACE ANALYSIS SHOWED THE SURFACE RIDGE OF HIGH PRESSURE DIRECTLY OVER CENTRAL NORTH CAROLINA...AND THIS WILL GRADUALLY MOVE TO THE EAST DURING THE AFTERNOON AS MID-LEVEL SHORTWAVE APPROACHES THE AREA FROM THE WEST AND NORTHWEST. IR IMAGES SHOW A SMALL REGION OF COLD-TOPPED CLOUDS ASSOCIATED WITH PRECIPITATION OVER PARTS OF KENTUCKY AND TENNESSEE...THOUGH GUIDANCE SUGGESTS THESE CLOUDS SHOULD WARM AND PRECIPITATION WEAKEN AS DRY AIR IS ENCOUNTERED TO THE EAST. THE MORNING KGSO SOUNDING SHOWED A PRECIPITABLE WATER VALUE UNDER A QUARTER-INCH...AND CENTRAL NORTH CAROLINA WAS REGIONALLY THE MINIMUM IN SURFACE THETA-E...ALONG WITH BUFR SOUNDINGS FROM THE NAM AND THE GFS MAINTAINING A FAIRLY DRY AIR MASS THROUGH THE AFTERNOON. A LARGE PATCH OF COOL HIGH SC/LOW AC TOWARD KRZZ AND KETC SHOULD GRADUALLY SHIFT EAST-SOUTHEAST LATE THIS MORNING AND THIS AFTERNOON IN CONCERT WITH THE LOW-LEVEL MOISTURE FIELDS OF THE RUC AND NAM...SUCH THAT MOST OF CENTRAL NORTH CAROLINA WILL SEE CONSIDERABLE SUNSHINE FOR MUCH OF THE DAY. MID-LEVEL CLOUDS WILL INCREASE LATE...AND WHILE MOISTURE INCREASES IN THE ICE NUCLEATION ZONE BETWEEN -10C AND -15C VERY LATE TODAY AND ESPECIALLY THIS EVENING...THE DEPTH OF MOISTURE IS SHALLOW WITH DRY AIR REMAINING IN THE BOUNDARY LAYER. KEPT HIGH TEMPERATURES AS IS THOUGH THE IMMEDIATE TRIAD MAY BE ON THE HIGH END OF THE EXPECTED RANGE...BUT GOOD SUN FOR MUCH OF THE DAY AND WEST WINDS WITH A FEW GUSTS IN THE LOWER TEENS KTS SHOULD HELP WARM THE AIR MASS. THE LATEST BUFR SOUNDINGS FROM THE NAM AND THE GFS SUGGEST THAT THE SOUTHWEST PIEDMONT INTO THE SANDHILLS HAVE A CHANCE OF SPRINKLES OVERNIGHT. TOWARD KGSO...KRDU...AND KRWI...THE MOISTURE DEPTH REMAINS SHALLOW...HOWEVER...TOWARD KFAY...ON BOTH MODELS THE DEPTH OF MOISTURE IS GREATER WITH ALSO GREATER MOISTURE IN THE BOUNDARY LAYER. WITH QPF FORECAST BY BOTH MODELS AS WELL...FOR NOW HAVE INTRODUCED SPRINKLES AND MAY HAVE TO INCREASE POPS INTO THE CHANCE CATEGORY FOR PARTS OF THIS AREA IN SUBSEQUENT FORECASTS...WHICH COULD LINGER INTO PART OF SATURDAY MORNING. THE INCREASE IN CLOUD COVER SHOULD LEAD TO WARMER OVERNIGHT LOW TEMPERATURES THAN PREVIOUS NIGHTS...WITH LOWS GENERALLY IN THE UPPER 30S TO LOWER 40S. -DJF SATURDAY: SURFACE HIGH PRESSURE CENTERED TO THE NORTH OF THE AREA SATURDAY MORNING WILL QUICKLY SHIFT OFFSHORE ON SATURDAY AFTERNOON RESULTING IN A RENEWED SOUTHERLY/SOUTHWESTERLY RETURN FLOW AFTER A BRIEF PERIOD OF NORTHERLY SURFACE FLOW BEHIND THE AFOREMENTIONED SURFACE TROUGH. HOWEVER... GIVEN LINGERING LOW LEVEL MOISTURE BELOW THE SUBSIDENCE INVERSION AROUND 800 MB ALONG WITH INCREASING MID AND HIGH CLOUDS IN ADVANCE OF A SYSTEM APPROACHING THE AREA FROM THE WEST WILL HELP KEEP SKIES PARTLY SUNNY DURING THE AFTERNOON. AFTERNOON LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS BELOW NORMAL AT LEAST. THUS... GIVEN THIS AND THE CLOUD COVER WILL CONTINUE TO TREND FORECAST HIGHS FOR SATURDAY A LITTLE BIT BELOW STATISTICAL GUIDANCE VALUES. THIS YIELDS HIGH TEMPS IN THE LOWER TO MID 60S ACROSS THE AREA. -BSD && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 305 AM FRIDAY... SATURDAY NIGHT INTO SUNDAY...INCREASING LOW LEVEL WAA COUPLED WITH MODEST MOISTURE TRANSPORT OFF THE NE GULF OF MEXICO AND ATLANTIC WILL AID IN THE DEVELOPMENT OF SPOTTY RAIN SHOWERS LATE SATURDAY NIGHT INTO SUNDAY MORNING...MAINLY ACROSS THE SOUTHERN AND WESTERN SECTIONS OF CENTRAL NC. INCREASING/THICKENING CLOUD COVERAGE AND A LIGHT SLY SFC WIND WILL RESULT IN MIN TEMPS SATURDAY NIGHT ABOUT 10 DEGREES WARMER THAN TONIGHT. LATER SUNDAY...A WEAK MID LEVEL TROUGH WILL CROSS THE REGION. THIS FEATURE INTERACTING WITH THE AVAILABLE MOISTURE AND WEAK INSTABILITY WILL TRIGGER ADDITIONAL SHOWER ACTIVITY. EXPECT SHOWER COVERAGE TO BE A LITTLE MORE IN THE NORTHERN PIEDMONT DUE TO CLOSE PROXIMITY OF A STALLED SURFACE BOUNDARY ACROSS SOUTHERN VA. SHOWER COVERAGE/INTENSITY SHOULD DIMINISH WEST-TO-EAST BY MID-LATE AFTERNOON AS THE MID LEVEL TROUGH EXITS THE REGION. RAIN TOTALS APPEAR MEAGER THOUGH DUE TO LACK OF STRONG CONVERGENCE IN THE LOW-MID LEVELS OF THE ATMOSPHERE. RAINFALL SHOULD TOTAL UNDER A QUARTER OF AN INCH WITH MOST LOCATIONS MEASURING LESS THAN A TENTH OF AN INCH. IN SPITE OF CONSIDERABLE CLOUDINESS AND SCATTERED SHOWERS...MAX TEMPS SUNDAY WILL BE JUST A FEW DEGREES SHY OF NORMAL...MAINLY IN THE MID-UPPER 60S. IF SHOWER COVERAGE IS MORE EXTENSIVE THAN CURRENT THINKING...THIS MAY HOLD DOWN TEMPS BY 4-6 DEGREES...ESPECIALLY ACROSS THE NW. SUNDAY NIGHT AND MONDAY...SUBSIDENCE IN WEAK OF DEPARTING MID LEVEL TROUGH ALONG WITH MEAN WLY FLOW WILL RESULT IN DECREASING CLOUD COVERAGE SUNDAY NIGHT INTO MONDAY. RESIDUAL SFC MOISTURE AND CLEARING SKIES ALOFT MAY ALLOW FOR THE DEVELOPMENT OF PATCHY FOG BY EARLY MONDAY. A LIGHT SW SFC FLOW ALONG WITH PATCHY CLOUD COVER SHOULD RESULT IN FAIRLY MILD OVERNIGHT TEMPS (COMPARED TO THE PAST TWO WEEKS). MIN TEMPS GENERALLY 50-55. A MIXTURE OF CLOUDS/SUN ON MONDAY PLUS A STEADY SW WIND OCCASIONALLY GUSTING BETWEEN 20-25 MPH WILL BOOST TEMPS TO NEAR OR SLIGHTLY ABOVE NORMAL (NEAR 70-LOWER 70S). AFTERNOON HEATING MAY TRIGGER A SHOWER OR TWO BUT MOST LOCATIONS WILL REMAIN DRY. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... AS OF 305 AM FRIDAY... MONDAY NIGHT THROUGH TUESDAY NIGHT...A MODERATE TO STRONG S/W IN THE NORTHERN BRANCH OF POLAR JET CROSSING THE GREAT LAKES WILL AID TO DRIVE THE STALLED SFC BOUNDARY ACROSS SOUTHERN VA THROUGH CENTRAL NC LATE MONDAY NIGHT INTO TUESDAY. GFS MUCH QUICKER WITH THIS FRONTAL MOVEMENT...ABOUT 6-8 HOURS FASTER COMPARED TO THE ECMWF. ECMWF HAS BACKING OF OTHER MODELS WHILE GFS APPEARS TO BE A SOUTHERN/EASTERN OUTLIER BY TUESDAY. THUS WILL FAVOR THE SLOWER FRONTAL ARRIVAL TIME. THIS REQUIRES SOME ADJUSTMENT TO MIN TEMPS MONDAY NIGHT. WILL RAISE MIN TEMPS ABOUT 5 DEGREES FROM PREVIOUS FORECAST (WITH THE POTENTIAL FOR MIN TEMPS TO BE AN ADDITIONAL 5-7 DEGREES WARMER). MIN TEMPS UPPER 40S TO LOWER 50S. COOL/MOIST NE FLOW BEHIND THE BOUNDARY WILL RESULT IN A DREARY DAY TUESDAY WITH PATCHES OF LIGHT RAIN PROBABLE IN THE HYBRID DAMMING SCENARIO. TEMPS WILL BE MUCH COOLER (ABOUT 20 DEGREES) COMPARED TO MONDAY WITH DAYTIME TEMPS 50-55. FOR MANY LOCATIONS...CALENDER DAY HIGH TEMPS WILL LIKELY OCCUR BETWEEN MIDNIGHT-8 AM. EXPECT IMPROVING CONDITIONS LATE TUESDAY INTO TUESDAY NIGHT AS SFC FRONT SLIDES FARTHER AWAY AND MID LEVEL TROUGH CROSSES THE REGION. MIN TEMPS TUESDAY NIGHT LOW-MID 30S. WEDNESDAY INTO THURSDAY WILL FEATURE DRY AND COOL CONDITIONS AS SURFACE HIGH OVER THE CENTRAL U.S. BUILDS INTO THE CAROLINAS AND BASE OF L/W TROUGH SETTLES OVERHEAD. THICKNESSES WEDNESDAY CLOSE TO 40M BELOW NORMAL WITH A MODEST RECOVERY ON THU. THIS SUGGEST AFTERNOON TEMPS WELL BELOW NORMAL FOR EARLY APRIL. MAX TEMPS 50-55 WEDNESDAY AND LOW-MID 50S THURSDAY. EXPECT MIN TEMPS EARLY THU IN THE 30-35 DEGREE RANGE. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 620 AM FRIDAY... 24 HOUR TAF PERIOD: VFR CONDITIONS ARE EXPECTED TO CONTINUE FOR THE 24 HOUR TAF PERIOD. SURFACE HIGH PRESSURE WILL SLOWLY SLIP TO THE SOUTH AND SOUTHEAST OF THE AREA TODAY... ALLOWING LIGHT NORTH TO NORTHWESTERLY WINDS THIS MORNING TO BECOME WEST TO SOUTHWESTERLY BY AFTERNOON IN THE 6 TO 10 KT RANGE... WITH POSSIBLY A FEW GUSTS OF AROUND 15 KTS OR SO DURING THE AFTERNOON (BEST CHANCE OF ANY WINDS GUSTS AT KINT/KGSO). EXPECT CLOUD COVER WILL BEGIN TO INCREASE ACROSS THE AREA IN THE MID TO LATE AFTERNOON AS A WEAK UPPER LEVEL DISTURBANCE APPROACHES THE AREA ALONG WITH AN ACCOMPANYING WEAK SURFACE TROUGH... WHICH IS EXPECTED TO MOVE THROUGH THE AREA LATE THIS EVENING INTO EARLY SATURDAY MORNING... WITH SURFACE HIGH PRESSURE BUILDING INTO THE AREA IN THE WAKE OF THE SYSTEM. THUS... EXPECT AN INCREASE IN CLOUD COVER (WITH MOSTLY TO CLOUDY TO EVEN OVERCAST SKIES EXPECTED LATE IN THE DAY INTO THE OVERNIGHT)... GENERALLY 5 KFT OR ABOVE... TO ACCOMPANY THE DISTURBANCE. OUTLOOK: VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH SATURDAY. LOW LEVEL MOISTENING WILL OCCUR SATURDAY NIGHT AS THE SURFACE RIDGE MOVES OFFSHORE... AND SUB-VFR CONDITIONS WITH FOG/STRATUS ARE EXPECTED TO FORM TOWARD SUNDAY MORNING WITH INCREASE CHANCES FOR SHOWERS. PERIODS OF SUB-VFR CONDITIONS ALONG WITH PERIODS OF SHOWERS ARE EXPECTED SUNDAY THROUGH TUESDAY AS A FRONTAL SYSTEM MOVES INTO THE AREA AND STALLS SOMEWHERE ACROSS THE REGION. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF/BSD SHORT TERM...WSS LONG TERM...WSS AVIATION...BSD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1041 AM CDT FRI MAR 29 2013 .UPDATE... ISSUED AT 1041 AM CDT FRI MAR 29 2013 FOG CONTINUES TO DISSIPATE ACROSS WESTERN AND PORTIONS OF CENTRAL NORTH DAKOTA THIS MORNING. AS A RESULT...CANCELLED THE DENSE FOG ADVISORY FOR AREAS ALONG AND WEST OF HIGHWAY 83. THE KGGW WSR-88D DETECTED AN AREA OF LIGHT PRECIPITATION MOVING EAST ACROSS NORTHEASTERN MONTANA THIS MORNING. THIS ACTIVITY IS EXPECTED TO ENTER NORTHWESTERN NORTH DAKOTA LATER THIS MORNING. HOWEVER...BY THE TIME IT REACHES SAID PORTION OF THE STATE...SURFACE TEMPS MAY BE NEAR OR ABOVE FREEZING. AS A RESULT...WILL HOLD OFF ON A FREEZING RAIN ADVISORY FOR NOW. WILL LIKELY HANDLE THE SITUATION WITH SPECIAL WEATHER STATEMENTS BASED ON SPOTTER REPORTS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 645 AM CDT FRI MAR 29 2013 NO MAJOR CHANGES FROM THE CURRENT FORECAST. DENSE FOG REMAINS ALONG THE MISSOURI RIVER COUNTIES AND ALL POINTS NORTH AND EAST. DID GET A REPORT OF BREAKS IN THE FOG IN MCLEAN COUNTY...BUT OVERALL SFC OBS ARE COMING IN AT 1/4SM OR ZERO. FREEZING RAIN HAS BEEN REPORTED IN GLASGOW MONTANA...AND WILL NEED TO MONITOR IN CASE A FREEZING RAIN ADVISORY BECOMES NEEDED THIS MORNING. RIGHT NOW IT IS UNCERTAIN WHERE THE BEST ACCUMULATING PRECIPITATION WILL FALL OVER MY WEST. THE RAP TAKES IT SOUTH OF THE MISSOURI RIVER WHILE THE EC AND GEM ARE FARTHER NORTH NEAR KISN...AND THE NAM BRINGS THE HIGHER QPF OVER MY FAR NORTHWEST ALONG THE CANADIAN BORDER. && .SHORT TERM...TODAY AND TONIGHT... ISSUED AT 330 AM CDT FRI MAR 29 2013 THE CHALLENGES OF THE SHORT TERM ARE HOW LONG THE ONGOING DENSE FOG WILL PERSIST...THE IMPACT OF THE FOG ON TEMPERATURES FOR TODAY AND THE POTENTIAL FOR ISOLATED THUNDERSTORMS ACROSS THE SOUTHWEST THIS AFTERNOON WITH A WINTRY MIX NORTH. THE RAP AND HRRR HAVE HAD A GOOD HANDLE ON THE EVOLUTION OF THE DENSE FOG ACROSS CENTRAL AND NORTHWEST NORTH DAKOTA THROUGH THE NIGHT...AND WILL FOLLOW THEIR VISIBILITY FORECASTS FROM THEIR LATEST RUN (29/04 UTC). THIS WOULD SUGGEST THAT DENSE FOG...ESPECIALLY OVER THE SNOWPACK MAY HOLD NEAR ONE QUARTER OF A MILE THROUGH 18 UTC. THIS IS SUPPORTED BY THE OBSERVED FOG TRENDS SEEN ON THURSDAY IN A SIMILAR ENVIRONMENT. THUS HAVE EXPANDED THE DENSE FOG ADVISORY THROUGH 18 UTC. WOULD NOT RULE OUT A POSSIBLE EXPANSION IN TIME FOR PORTIONS OF THE ADVISORY LATER INTO THE AFTERNOON AS MID LEVEL CLOUD COVER MAY SLOW DOWN THE BURNING OFF OF THE FOG. IN REGARDS TO TEMPERATURES...WILL USE THE OBSERVED TEMPERATURE PATTERN ON THURSDAY AS A GUIDE...AND WILL LIMIT HIGHS TO THE UPPER 20S ACROSS MUCH OF THE SNOWPACK IMPACTED BY FOG. LIKE THURSDAY...THE SNOW AND FOG FREE SOUTHWEST IS EXPECTED TO WARM INTO THE UPPER 50S TO THE LOWER 60S AS MIXING INCREASES BEHIND A WEAK TROUGH. STEEP LAPSE RATES THROUGH MUCH OF THE TROPOSPHERE SUGGESTS DIURNALLY DRIVEN SHOWER ACTIVITY IS POSSIBLE...WITH ISOLATED THUNDERSTORMS NOT OUT OF THE QUESTION GIVEN THE COOL TEMPERATURES ALOFT AND STEEP LAPSE RATES SUPPORTING AFTERNOON ML CAPE VALUES OF 200-400 J/KG. ELSEWHERE IN REGARDS TO PRECIPITATION TODAY...A WEAK WAVE ACROSS SOUTHWEST SASKATCHEWAN AS OF 08 UTC WILL PROPAGATE SOUTHEAST THROUGH THE DAY. GIVEN THE WEAK FORCING AND DRY LOW LEVELS...PRECIPITATION WITH SCATTERED ACTIVITY WILL BE LIGHT. HOWEVER...WITH A WARM LAYER ALOFT ABOVE THE SUB-FREEZING SURFACE TEMPERATURES OF THE SNOWPACK...FREEZING RAIN AND SLEET ARE POSSIBLE. FOR TONIGHT...BOUNDARY LAYER MIXING ON THE ORDER OF 10 KTS CWA WIDE IN THE WAKE OF THE AFOREMENTIONED SURFACE TROUGH SHOULD HELP TO KEEP TEMPERATURES FROM BOTTOMING OUT TOO FAR...WITH SOME STRATUS ALSO HINTED IN THE 00 UTC DETERMINISTIC GUIDANCE. THUS...FOLLOWED FAIRLY CLOSELY TO A BLEND OF THE 00 UTC DETERMINISTIC MODEL SUITE FOR LOWS TONIGHT. .LONG TERM...SATURDAY THROUGH NEXT FRIDAY... ISSUED AT 330 AM CDT FRI MAR 29 2013 WILL SEE AN ACTIVE FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND AS A CLOSED UPPER LOW MOVES SOUTH ACROSS CENTRAL CANADA ON SATURDAY AND INTO THE GREAT LAKES REGION SUNDAY AND MONDAY. CYCLONIC FLOW ALOFT WILL BRING SEVERAL EMBEDDED S/WVS ACROSS THE NORTHERN PLAINS SATURDAY THROUGH SUNDAY AFTERNOON SO WILL MAINTAIN PRECIP CHANCES. ONLY LIGHT QPF IS DEPICTED. THE UPPER LOW WILL ALSO BRING A SURGE OF COLDER AIR INTO THE NORTHERN PLAINS SUNDAY INTO MONDAY. TEMPERATURES MODERATE BACK TO NORMAL BY MID-WEEK AS THE COLDER AIR MOVES OFF TO OUR EAST. WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. OPTED TO KEEP THE FORECAST DRY. NEXT CHANCE OF PRECIPITATION ARRIVES AT THE END OF THE WORK WEEK WHEN THE UPPER JET PUSHES SOUTH TO ACROSS FAR SOUTHERN CANADA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 645 AM CDT FRI MAR 29 2013 VLIFR CONDITIONS IN FOG WILL CONTINUE AT KMOT AND KJMS THROUGH AT LEAST 18 UTC FRIDAY...WITH SLOW IMPROVEMENT THEREAFTER. VLIFR FOG AT KBIS SHOULD BURN OFF A BIT FASTER...IN THE 15-17 UTC TIMEFRAME WITH THE LACK OF A DEEP SNOWPACK. KISN AND KDIK HAVE REMAINED ON THE FRINGE OF THE FOG BANK THUS FAR TONIGHT...AND ARE EXPECTED TO THROUGH FRIDAY MORNING. THAT SAID...TEMPORARY REDUCTIONS TO IFR CANNOT BE RULED OUT. SCATTERED PRECIPITATION POSSIBLY IN THE FORM OF FREEZING RAIN OR SLEET MAY IMPACT KISN AND KMOT...AND POSSIBLY KJMS FRIDAY EVENING. SCATTERED SHOWERS WITH POSSIBLY AN ISOLATED THUNDERSTORM IS POSSIBLE NEAR KDIK FRIDAY AFTERNOON. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR NDZ004-005- 012-013-022-023-025-036-037-047-048-050-051. && $$ UPDATE...TM SHORT TERM...AYD LONG TERM...NH AVIATION...AYD/NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
645 AM CDT FRI MAR 29 2013 .UPDATE... ISSUED AT 645 AM CDT FRI MAR 29 2013 NO MAJOR CHANGES FROM THE CURRENT FORECAST. DENSE FOG REMAINS ALONG THE MISSOURI RIVER COUNTIES AND ALL POINTS NORTH AND EAST. DID GET A REPORT OF BREAKS IN THE FOG IN MCLEAN COUNTY...BUT OVERALL SFC OBS ARE COMING IN AT 1/4SM OR ZERO. FREEZING RAIN HAS BEEN REPORTED IN GLASGOW MONTANA...AND WILL NEED TO MONITOR IN CASE A FREEZING RAIN ADVISORY BECOMES NEEDED THIS MORNING. RIGHT NOW IT IS UNCERTAIN WHERE THE BEST ACCUMULATING PRECIPITATION WILL FALL OVER MY WEST. THE RAP TAKES IT SOUTH OF THE MISSOURI RIVER WHILE THE EC AND GEM ARE FARTHER NORTH NEAR KISN...AND THE NAM BRINGS THE HIGHER QPF OVER MY FAR NORTHWEST ALONG THE CANADIAN BORDER. && .SHORT TERM...TODAY AND TONIGHT... ISSUED AT 330 AM CDT FRI MAR 29 2013 THE CHALLENGES OF THE SHORT TERM ARE HOW LONG THE ONGOING DENSE FOG WILL PERSIST...THE IMPACT OF THE FOG ON TEMPERATURES FOR TODAY AND THE POTENTIAL FOR ISOLATED THUNDERSTORMS ACROSS THE SOUTHWEST THIS AFTERNOON WITH A WINTRY MIX NORTH. THE RAP AND HRRR HAVE HAD A GOOD HANDLE ON THE EVOLUTION OF THE DENSE FOG ACROSS CENTRAL AND NORTHWEST NORTH DAKOTA THROUGH THE NIGHT...AND WILL FOLLOW THEIR VISIBILITY FORECASTS FROM THEIR LATEST RUN (29/04 UTC). THIS WOULD SUGGEST THAT DENSE FOG...ESPECIALLY OVER THE SNOWPACK MAY HOLD NEAR ONE QUARTER OF A MILE THROUGH 18 UTC. THIS IS SUPPORTED BY THE OBSERVED FOG TRENDS SEEN ON THURSDAY IN A SIMILAR ENVIRONMENT. THUS HAVE EXPANDED THE DENSE FOG ADVISORY THROUGH 18 UTC. WOULD NOT RULE OUT A POSSIBLE EXPANSION IN TIME FOR PORTIONS OF THE ADVISORY LATER INTO THE AFTERNOON AS MID LEVEL CLOUD COVER MAY SLOW DOWN THE BURNING OFF OF THE FOG. IN REGARDS TO TEMPERATURES...WILL USE THE OBSERVED TEMPERATURE PATTERN ON THURSDAY AS A GUIDE...AND WILL LIMIT HIGHS TO THE UPPER 20S ACROSS MUCH OF THE SNOWPACK IMPACTED BY FOG. LIKE THURSDAY...THE SNOW AND FOG FREE SOUTHWEST IS EXPECTED TO WARM INTO THE UPPER 50S TO THE LOWER 60S AS MIXING INCREASES BEHIND A WEAK TROUGH. STEEP LAPSE RATES THROUGH MUCH OF THE TROPOSPHERE SUGGESTS DIURNALLY DRIVEN SHOWER ACTIVITY IS POSSIBLE...WITH ISOLATED THUNDERSTORMS NOT OUT OF THE QUESTION GIVEN THE COOL TEMPERATURES ALOFT AND STEEP LAPSE RATES SUPPORTING AFTERNOON ML CAPE VALUES OF 200-400 J/KG. ELSEWHERE IN REGARDS TO PRECIPITATION TODAY...A WEAK WAVE ACROSS SOUTHWEST SASKATCHEWAN AS OF 08 UTC WILL PROPAGATE SOUTHEAST THROUGH THE DAY. GIVEN THE WEAK FORCING AND DRY LOW LEVELS...PRECIPITATION WITH SCATTERED ACTIVITY WILL BE LIGHT. HOWEVER...WITH A WARM LAYER ALOFT ABOVE THE SUB-FREEZING SURFACE TEMPERATURES OF THE SNOWPACK...FREEZING RAIN AND SLEET ARE POSSIBLE. FOR TONIGHT...BOUNDARY LAYER MIXING ON THE ORDER OF 10 KTS CWA WIDE IN THE WAKE OF THE AFOREMENTIONED SURFACE TROUGH SHOULD HELP TO KEEP TEMPERATURES FROM BOTTOMING OUT TOO FAR...WITH SOME STRATUS ALSO HINTED IN THE 00 UTC DETERMINISTIC GUIDANCE. THUS...FOLLOWED FAIRLY CLOSELY TO A BLEND OF THE 00 UTC DETERMINISTIC MODEL SUITE FOR LOWS TONIGHT. .LONG TERM...SATURDAY THROUGH NEXT FRIDAY... ISSUED AT 330 AM CDT FRI MAR 29 2013 WILL SEE AN ACTIVE FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND AS A CLOSED UPPER LOW MOVES SOUTH ACROSS CENTRAL CANADA ON SATURDAY AND INTO THE GREAT LAKES REGION SUNDAY AND MONDAY. CYCLONIC FLOW ALOFT WILL BRING SEVERAL EMBEDDED S/WVS ACROSS THE NORTHERN PLAINS SATURDAY THROUGH SUNDAY AFTERNOON SO WILL MAINTAIN PRECIP CHANCES. ONLY LIGHT QPF IS DEPICTED. THE UPPER LOW WILL ALSO BRING A SURGE OF COLDER AIR INTO THE NORTHERN PLAINS SUNDAY INTO MONDAY. TEMPERATURES MODERATE BACK TO NORMAL BY MID-WEEK AS THE COLDER AIR MOVES OFF TO OUR EAST. WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. OPTED TO KEEP THE FORECAST DRY. NEXT CHANCE OF PRECIPITATION ARRIVES AT THE END OF THE WORK WEEK WHEN THE UPPER JET PUSHES SOUTH TO ACROSS FAR SOUTHERN CANADA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 645 AM CDT FRI MAR 29 2013 VLIFR CONDITIONS IN FOG WILL CONTINUE AT KMOT AND KJMS THROUGH AT LEAST 18 UTC FRIDAY...WITH SLOW IMPROVEMENT THEREAFTER. VLIFR FOG AT KBIS SHOULD BURN OFF A BIT FASTER...IN THE 15-17 UTC TIMEFRAME WITH THE LACK OF A DEEP SNOWPACK. KISN AND KDIK HAVE REMAINED ON THE FRINGE OF THE FOG BANK THUS FAR TONIGHT...AND ARE EXPECTED TO THROUGH FRIDAY MORNING. THAT SAID...TEMPORARY REDUCTIONS TO IFR CANNOT BE RULED OUT. SCATTERED PRECIPITATION POSSIBLY IN THE FORM OF FREEZING RAIN OR SLEET MAY IMPACT KISN AND KMOT...AND POSSIBLY KJMS FRIDAY EVENING. SCATTERED SHOWERS WITH POSSIBLY AN ISOLATED THUNDERSTORM IS POSSIBLE NEAR KDIK FRIDAY AFTERNOON. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 1 PM CDT /NOON MDT/ THIS AFTERNOON FOR NDZ001>005-009>013-019>023-025-034>037-042-045>048-050-051. && $$ UPDATE...NH AVIATION...AYD/NH SHORT TERM...AYD LONG TERM...NH
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
630 AM CDT FRI MAR 29 2013 .AVIATION... MVFR CEILINGS ARE EXPECTED THROUGH 18-19Z BEFORE CLOUDS LIFT ABOVE 3000 FEET. SOUTH WINDS 10-16 KNOTS WILL PREVAIL. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP TO THE NORTHWEST OF NORTH TEXAS LATE AFTERNOON/EARLY EVENING AND THEN MOVE SOUTHEAST TONIGHT. THE CHANCES ARE NOT HIGH ENOUGH TO MENTION TSRA IN THE TAFS AT THIS TIME...BUT HAVE PLACED VCSH IN THE METROPLEX TAFS SITES FOR THE 03Z THROUGH 08Z PERIOD. MVFR CEILINGS ARE EXPECTED TO SPREAD BACK NORTH AFTER 07Z AT WACO...AND AFTER 08Z IN THE METROPLEX. 58 && .PREV DISCUSSION... /ISSUED 350 AM CDT FRI MAR 29 2013/ LATEST UPPER AIR ANALYSIS SHOWS TROUGHS OF LOW PRESSURE ACROSS THE NORTHEASTERN CONUS AND NORTHWESTERN CANADA. A SHORTWAVE CAN BE SEEN MOVING ONSHORE BAJA CALIFORNIA AND THIS DISTURBANCE WILL BE THE MAIN FOCUS FOR THE NEXT 24 HOURS. ON THE SURFACE...A LOW CENTER REMAINS POSITIONED NEAR THE TEXAS PANHANDLE WITH A TROUGH EXTENDING TO THE EAST INTO OKLAHOMA. THE 00Z FWD RAOB INDICATED A STOUT CAP IN PLACE AS WEST WINDS BETWEEN 700 AND 800 MB ARE LEADING TO WARM AIR ADVECTION. THIS CAP WILL KEEP NORTH TEXAS RAIN FREE FOR MOST OF THE DAY TODAY. THE FORECAST THEN BECOMES PROBLEMATIC AS THE SHORTWAVE NEARS THE REGION THIS EVENING. THE MODELS DIFFER ON THE HANDLING OF THIS SYSTEM AND THE WEAKENING OF THE CAP BY LATE AFTERNOON. THE GFS KEEPS THE CAP IN PLACE AND MOST OF THE AREA RAIN FREE...WHILE THE NAM/WRF/CANADIAN/ECMWF ALL WEAKEN THE CAP TO SOME DEGREE. THE NAM IS THE MOST AGGRESSIVE WITH THE REMOVAL OF THE CAP COMPLETELY BY 00Z. CURRENTLY ON WATER VAPOR THE SHORTWAVE LOOKS STRONGER THAN WHAT MOST MODELS HAVE INITIALIZED. THE DISTURBANCE IS STRONG ENOUGH THAT IT CAN BE SEEN ON CONSTANT PV SURFACES AS THE TROPOPAUSE DESCENDS IN THE ATMOSPHERE WITHIN THE CENTER OF THE TROUGH OF LOW PRESSURE. THE 00-HR RAP IS CURRENTLY INITIALIZING THIS TO OCCUR AT 330 MB...WHILE THE GFS AND NAM ARE AT 280 MB AND 295 MB RESPECTIVELY. WITH THE STRONGER TROUGH...WILL HOLD MORE WEIGHT WITH THE NAMS FORECAST OF ERODING THE CAP THIS AFTERNOON. HIGH-RES MODELS ARE INITIALIZING THUNDERSTORM DEVELOPMENT WEST/NORTHWEST OF THE FORECAST AREA...NEAR THE SURFACE LOW BEFORE 00Z THIS EVENING. PREVIOUS THINKING WAS THE CAP WOULD HOLD AND THESE STORMS WOULD WEAKEN AS THEY PROGRESSED EAST...RUNNING INTO THE CAP. IF THE CAP DOES ERODE...THERE SHOULD BE A DECENT COVERAGE OF STORMS INTO THE NORTHWEST ZONES AFTER 00Z. WITH CAPE VALUES NEAR 1500 J/KG AND MODERATE SHEAR VALUES A STRONG TO MARGINALLY SEVERE STORM IS POSSIBLE. OVERNIGHT...A COMPLEX OF STORMS IS EXPECTED TO DEVELOP NEAR THE SURFACE TROUGH IN OKLAHOMA AND THIS ACTIVITY COULD CLIP OUR NORTHEASTERN ZONES NEAR SUNRISE SATURDAY. AFTER THIS SYSTEM MOVES OUT ON SATURDAY...THINK THE REMAINDER OF THE DAY SHOULD BE RELATIVELY QUIET AS NO LARGE SCALE FORCING FOR ASCENT IS IN PLACE. SATURDAY NIGHT...THE TROUGH THAT IS CURRENTLY IN NORTHWESTERN CANADA WILL CONTINUE TO SLIDE SOUTHEAST AND SEND A COLD FRONT INTO SOUTHERN OKLAHOMA. THIS FRONT COMBINING WITH ANOTHER WEAK EMBEDDED SHORTWAVE WILL BRING MORE THUNDERSTORM CHANCES TO MAINLY THE NORTHERN ZONES. THIS FRONTAL BOUNDARY IS EXPECTED TO STALL NEAR THE I-20 CORRIDOR SUNDAY AFTERNOON AS THE UPPER LOW SHIFTS EAST. WITH THE SURFACE FOCUS IN PLACE FOR THE CWA...ADDITIONAL THUNDERSTORMS ARE POSSIBLE FOR THE AREA. CAPE VALUES MAY EXCEED 2000 J/KG AS LOWER 60 DEWPOINTS WILL BE IN PLACE. SHEAR IS EXPECTED TO BE WEAKER AND THIS WILL LIMIT THE OVERALL SEVERE POTENTIAL...BUT CANT RULE OUT A STRONG OR MARGINALLY SEVERE STORM SUNDAY AFTERNOON. ANOTHER SOUTHWARD MOVING IMPULSE OF UPPER ENERGY OUT OF CANADA WILL SEND A STRONGER FRONT SOUTH ON MONDAY. THIS FRONT IS EXPECTED TO MOVE THROUGH THE CWA MONDAY EVENING AND WILL CARRY ADDITIONAL THUNDERSTORM CHANCES WITH THE FROPA. MEDIUM RANGE GUIDANCE HAS HAD POOR RUN-TO-RUN CONSISTENCY WITH THE HANDLING OF FEATURES BEYOND MONDAY. THE 00Z GFS AND ECMWF ARE SIMILAR AND KEEP STRONG UPGLIDE ON TOP OF THE FRONTAL INVERSION THROUGH TUESDAY NIGHT AND WILL KEEP SLIGHT TO CHANCE POPS FOR LIGHT RAIN IN THE FORECAST. AFTER A VERY ACTIVE PERIOD...THE FINAL CHANCE OF RAIN WILL COME WHEN THE UPPER TROUGH CURRENTLY OVER THE PACIFIC OCEAN WILL SWING THROUGH THE AREA WEDNESDAY/WEDNESDAY NIGHT. MODELS LAST NIGHT SHOWED THIS LOW WEAKENING BEFORE IT MOVED THROUGH...BUT TONIGHT KEEP IT AS A STRONGER CLOSED LOW. THE TRACK OF THE LOW IS DIFFERENT BETWEEN THE GFS AND ECMWF...BUT BOTH SHOW LARGE SCALE FORCING FOR ASCENT AND WILL FORECAST 30 POPS FOR WEDNESDAY AND WEDNESDAY NIGHT. AGAIN...MODELS HAVE HAD A HARD TIME WITH THE FORECAST BEYOND MONDAY AND CONFIDENCE IS NOT HIGH. NEVERTHELESS...AN UNSETTLED WEATHER PATTERN IS EXPECTED BETWEEN TODAY AND NEXT WEDNESDAY WITH RAIN CHANCES IN THE FORECAST EACH DAY FOR MOST OF THE AREA. IT WONT RAIN EVERYDAY FOR ALL LOCATIONS...BUT CHANCES ARE THERE EACH DAY. TEMPERATURES THROUGH MONDAY WILL BE IN THE 70S/80S FOR HIGHS WITH LOWS IN THE 50S/60S. AFTER MONDAY...TEMPERATURES WILL BE DRASTICALLY COLDER BEHIND THE FRONT. HIGHS BEHIND THE FRONT TUESDAY AND WEDNESDAY WILL BE IN THE 40S/50S FOR HIGHS WITH LITTLE DIURNAL RANGE GIVEN THE CLOUD COVER AND RAIN CHANCES. SOUTH WINDS WILL RETURN BY THE END OF THE WEEK AND MODERATING TEMPERATURES CAN BE EXPECTED. HAMPSHIRE && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 77 62 80 62 76 / 10 30 20 40 40 WACO, TX 77 61 79 64 79 / 5 20 20 20 40 PARIS, TX 73 58 75 60 74 / 20 50 30 50 40 DENTON, TX 75 61 80 58 75 / 10 30 20 40 40 MCKINNEY, TX 75 61 80 60 76 / 10 30 20 40 40 DALLAS, TX 77 62 81 63 76 / 10 30 20 40 40 TERRELL, TX 76 62 79 63 75 / 10 30 20 30 40 CORSICANA, TX 76 60 77 62 78 / 10 20 20 20 40 TEMPLE, TX 76 61 78 62 81 / 5 10 20 20 30 MINERAL WELLS, TX 77 57 83 59 78 / 10 40 20 30 40 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 58/85
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1220 PM CDT FRI MAR 29 2013 .DISCUSSION... ISSUED 948 AM CDT FRI MAR 29 2013 HIGH PRESSURE AXIS CURRENTLY ANALYZED FROM WISCONSIN SOUTHEAST INTO THE CAROLINAS. EARLIER WARM AIR ADVECTION SHOWERS HAVE SHIFTED INTO THE OHIO VALLEY...ALTHOUGH SOME ALTOCUMULUS LINGERS IN THE FORECAST AREA AND HAVE EVEN HAD A FEW SPRINKLES OUT OF IT AROUND CHAMPAIGN. WHILE THE ALTOCUMULUS SHOULD DIMINISH WITH TIME...CU-RULE OFF THE RAP MODEL SHOWS SOME DIURNAL CUMULUS POTENTIAL FOR THIS AFTERNOON...WITH THE NET RESULT BEING PARTLY TO MOSTLY SUNNY SKIES. MORNING COOPERATIVE OBSERVATIONS SHOWING ONLY 1 TO 3 INCHES OF SNOW LINGERING FROM NEAR LINCOLN SOUTHWEST TO PITTSFIELD AND TRACE AMOUNTS EASTWARD...AND MUCH OF THIS SHOULD DISAPPEAR TODAY AS HIGHS REACH INTO THE 50S. HAVE SENT SOME UPDATED GRIDS TO ADJUST HOURLY TRENDS...BUT NO CHANGES NEEDED TO THE ZONE FORECASTS AT THIS TIME. GEELHART && .AVIATION... ISSUED 1220 PM CDT FRI MAR 29 2013 VFR CONDITIONS EXPECTED THE NEXT 24 HOURS. SOME SCATTERED TO BROKEN CLOUDS AROUND 5000 FEET ARE EXPECTED THROUGH THE AFTERNOON. WOULD NOT BE SURPRISED TO SEE THESE LINGER NEAR KSPI/KDEC FURTHER INTO THE EVENING. SATURDAY MORNING...WILL BEGIN TO SEE A GENERAL INCREASE IN CLOUDS FROM THE WEST...ALTHOUGH REMAINING VERY HIGH THROUGH THE MORNING. WINDS THROUGH THIS EVENING WILL GENERALLY REMAIN EASTERLY DUE TO AN AREA OF HIGH PRESSURE OVER THE MIDWEST...THEN TREND TOWARD THE SOUTHEAST AND INCREASE ON SATURDAY AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. GEELHART && .PREV DISCUSSION... ISSUED 236 AM CDT FRI MAR 29 2013 SHORT TERM...TODAY THROUGH SATURDAY SURFACE RIDGE AXIS EXTENDING FROM THE UPPER MS VALLEY SOUTHEAST INTO THE OHIO VALLEY PROVIDED LIGHT WINDS OVERNIGHT. SCATTERED SHOWERS WERE AFFECTING SOUTHERN MO IN THE VICINITY OF A SFC WARM FRONT...WHILE ELEVATED WARM ADVECTION WAS PRODUCING SHOWERS INTO SOUTHERN IL. OBSERVATIONAL TRENDS SUGGEST THIS ACTIVITY WILL REMAIN SOUTH OF THE AREA THIS MORNING...BUT MAIN AFFECT FOR MOST AREAS WILL BE AREAS OF AC AND MOSTLY CLOUDY SKIES THIS MORNING. AS THE SYSTEM SINKS SOUTHEAST...A CLEARING TREND WORKS IN FROM THE NORTH THIS AFTERNOON. WILL ADD A FEW DEGREES TO YESTERDAYS HIGHS WITH MOST AREAS GETTING INTO THE LOW/MID 50S. A COLD FRONT MOVING ACROSS THE STATE SATURDAY AFTERNOON/NIGHT BRINGS SCATTERED SHOWERS WITH GENERALLY LIGHT QPF OF A QUARTER TO LESS THAN A HALF INCH. 00Z NAM HAD TRENDED MUCH QUICKER WITH THIS FEATURE BRINGING SHOWERS ALL THE WAY TO EASTERN IL BY SAT AFTERNOON. FEEL THIS IS A BIT FAST AND HAVE BASED FORECAST ON SREF/GFS BLEND WHICH BRINGS RAIN WEST OF THE IL RIVER BY MID TO LATE AFTERNOON...THEN SHIFTS EAST ACROSS THE REMAINDER OF THE CWA THROUGH EVENING. SOUTHERLY FLOW AHEAD OF THE FRONT WILL PRODUCE THE WARMEST DAY OF THE MONTH FOR MANY AREAS WITH HIGHS IN THE UPPER 50S. LONG TERM...SUNDAY THROUGH THURSDAY NOT MUCH OF A COOL PUSH BEHIND THE INITIAL FRONT AND READINGS EXPECTED TO GET BACK UP INTO THE 50S SUNDAY ALONG WITH A FAIR AMOUNT OF SUNSHINE. AN ARCTIC FRONT DIVING IN FROM THE NORTH SUNDAY NIGHT SENDS TEMPERATURES CRASHING BACK WELL BELOW NORMAL. FRONTOGENETIC FORCING ALONG/BEHIND THE BOUNDARY WILL WRING OUT WHAT MOISTURE REMAINS AFTER THE PREVIOUS FRONTAL PASSAGE. THERMAL PROFILES SUGGEST THE BULK OF THE PRECIP TO FALL AS SNOW AFTER A BRIEF RAIN/SNOW MIX AT ONSET SUNDAY NIGHT. NAM MOST AGGRESSIVE AT BRINGING ACCUMULATING SNOW...BUT GIVEN PROGRESSIVE NATURE OF FRONT AND WARM GROUND FEEL ANY ACCUMULATIONS WILL BE MINOR. SNOW SHOULD EXIT THE SOUTH/EAST MONDAY MORNING. BRISK NORTHERLY WINDS ON THE EASTERN FLANK OF STRONG LATE SEASON 1035 MB ARCTIC HIGH BUILDING INTO THE NORTHERN PLAINS...BRINGS STRONG COLD ADVECTION. 850 MB TEMPS DIP AS LOW AS -12C ACROSS CENTRAL IL MONDAY AFTERNOON THROUGH TUESDAY. THIS PRODUCES TEMPERATURES 20+ DEGREES BELOW NORMAL WHICH MAY NOT BE TOO FAR FROM RECORD TERRITORY. IN CONTRAST TO THE LAST ARCTIC AIR MASS...CYCLONIC FLOW IS DISPLACED MUCH FARTHER NORTHEAST THIS TIME AROUND AND SHOULD RESULT IN MORE SUNSHINE BY DAY AND CLEAR COLD NIGHTS. UNSEASONABLY COLD AND DRY WEATHER CONTINUES THROUGH MID WEEK AS THE MODIFIED ARCTIC RIDGE SETTLES OVERHEAD. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1227 PM EDT FRI MAR 29 2013 .UPDATE... ISSUED AT 1227 PM EDT FRI MAR 29 2013 GRID UPDATE COMPLETED TO ADJUST FOR GENERALLY FASTER TRENDS IN TEMP CLIMB...MUCH LOWER DEWPTS ACROSS THE NORTH AND SKY COVER. SLOWLY DECREASING AREA OF MID CLOUDS THAT ORIGINATED OVER N ILLINOIS WAS SLOWLY DRIFTING SE IMPACTING MAINLY ALONG AND SOUTH OF US 30. WARMING CLOUD TOPS AND OVERALL APPEARANCE OF THE CLOUDS WOULD SUGGEST A CONTINUATION OF MIXING OUT SHOULD OCCUR OVER THE NEXT COUPLE OF HOURS...LEADING TO SUNNY TO MOSTLY SUNNY SKIES. TEMPS CLIMBED FAIRLY RAPIDLY THIS MORNING BUT HAVE SINCE SHOWED SIGNS OF SLOWING DOWN. IN AREAS WHERE THE SNOW PACK HAS BEEN GONE MUCH DRIER SFC DEWPTS WERE IN PLACE WITH READINGS IN THE UPR TEENS TO LOWER 20S VS UPR 20S TO AROUND 30 IN FAR S SECTIONS. DO EXPECT THESE HIGHER DEWPTS TO MIX SOMEWHAT THROUGH THE DAY AS THE CLOUD COVER LEAVES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 523 AM EDT FRI MAR 29 2013 WEAK SHORT WAVE AND ASSOCIATED JET STREAK MOVING ACROSS THE GREAT LAKES THIS MORNING. COUPLED WITH WEAK MID LEVEL THETA E ADVECTION THESE FEATURES HAVE HELPED GENERATE AN AREA OF MID LEVEL CLOUDS THIS MORNING JUST TO OUR WEST. RAP13 SEEMS TO HAVE BEST HANDLE ON THIS MOISTURE WITH ITS 850-700MB LAYER RH. HRRR IS TRYING TO CATCH UP BUT STILL DOES NOT APPEAR TO HAVE THE SCOPE SEEN ON SATELLITE. SPECTRAL MODELS GENERALLY CLUELESS. SHORT WAVE WILL PASS THROUGH OUR AREA DURING EARLY TO MID MORNING HOURS. RAP13 MOVES HIGHER RH VALUES ACROSS WESTERN HALF OF OUR AREA THIS MORNING AND GRADUALLY SINKS THIS AREA SOUTH WHILE MIXING ALSO HELPS TO ERODE CLOUDS. HAVE INCREASED CLOUD COVER THIS MORNING SUBSTANTIALLY ACROSS WESTERN AREAS USING SATELLITE TRENDS AND RAP AS GUIDANCE. GRADUALLY DECREASED AMOUNT OF SKY COVER BY EARLY AFTERNOON SO SHOULD SEE A PARTLY TO MOSTLY CLOUDY MORNING TRANSITIONING TO MOSTLY SUNNY THIS AFTERNOON. EASTERN AREAS TO REMAIN FAR ENOUGH REMOVED PER TRAJECTORIES TO KEEP MOSTLY SUNNY THROUGH THE DAY. RESULT OF THIS MAY HELP KEEP TEMPS DOWN A FEW DEGREES WEST BUT EXPECT RAPID INCREASE ONCE CLOUDS DEPART. OTHERWISE TEMPS WILL BE A FEW DEGREES WARMER THAN THURSDAY OUTSIDE OF CLOUDS. WARMER TEMPS ON SATURDAY AHEAD OF NEXT SHORT WAVE WITH HIGHS NEARING 60. INCREASING HIGH CLOUDS IN AFTERNOON MAY SLOW WARMING BUT IF SKIES REMAIN CLEAR WOULD EXPECT SOME AREAS INTO 60S GIVEN MOS COOL BIAS YESTERDAY WITH FULL SUN. STRONG THETA E SURGE WITH MID LEVEL TROUGH APPROACHING SAT NIGHT SHOULD LEAD TO RAIN SHOWERS. MODELS CONTINUE TO TREND FASTER WITH NAM12 SHOWING PCPN DURING FIRST HALF OF NIGHT. USED COMPROMISE OF SOLUTIONS FOR TIMING BUT LOOKS LIKE ALL AREAS WILL RECEIVE A NICE RAINFALL OF ONE QUARTER TO ONE HALF INCH. ELEVATED THUNDER STILL NOT OUT OF QUESTION BUT REMAINS LOW PROB EVENT SO NO INCLUSION JUST YET. IF WE CAN GET SOME LIGHTNING WITH THIS RAIN RAPID GREEN UP WOULD BE EXPECTED IN WAKE OF RAIN. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 523 AM EDT FRI MAR 29 2013 SUNDAY THROUGH THURSDAY...A WEAK UPPER LEVEL TROF WILL BE MOVING ACROSS THE AREA SUNDAY...FOLLOWED BY A COLD FRONT SUNDAY NIGHT. THERMAL PROFILES SUNDAY ARE BORDERLINE BETWEEN RAIN AND A RAIN/SNOW MIX SUNDAY MORNING OVER NORTHERN AREAS...ESPECIALLY THE GFS. FOR NOW LEFT JUST RAIN IN THE FCST GIVEN SFC TEMPERATURES MAINLY IN THE 40S AND NAM 1000/850 MB THICKNESSES ALMOST EXCLUSIVELY ABOVE 1300 METERS. VERY CHILLY AIR WILL ONCE AGAIN SPREAD ACROSS THE AREA SUNDAY NIGHT AND MONDAY. DELTA T VALUES SUPPORT SOME LAKE EFFECT SNOW SHOWERS...HOWEVER...VERY LITTLE PRECONDITIONING IS EXPECTED. A 300 TO 310 FETCH WITH UPSTREAM DEW PTS IN THE SINGLE DIGITS MAY NOT ALLOW MUCH MORE THAN LAKE EFFECT CLOUDS. OTHERWISE...ATTEMPTED TO TREND TEMPERATURES DOWN MONDAY NIGHT THROUGH WEDNESDAY IN LINE WITH THE GFS MEX MOS. 850 MB TEMPS TUESDAY MORNING NEAR -14C TUESDAY WILL HELP KEEP HIGHS IN THE 30S...ESPECIALLY NEAR THE LAKE WITH LAKE ENHANCED CLOUDS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1227 PM EDT FRI MAR 29 2013 A VFR MID DECK OF CLOUDS HAS BEEN PROGRESSIVELY MIXING OUT...IMPACTING ONLY FT WAYNE AT THIS TIME. OVER THE NEXT COUPLE OF HOURS CLEAR SKIES SHOULD SETTLE IN WITH CONTINUATION OF LIGHT WINDS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...FISHER SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...FISHER
AREA FORECAST DISCUSSION
NWS JACKSON KY
133 PM EDT FRI MAR 29 2013 .UPDATE... ISSUED AT 1253 PM EDT FRI MAR 29 2013 HAVE UPDATED NDFD AND ZFP FOR LATEST OBSERVATIONAL TRENDS. RAIN HAS MEASURED AT MONTICELLO AND IT HAS STARTED RAINING AT SME. MAIN CHANGES WERE TO REDUCE THE NORTHERN EXTENT OF ANY RAIN CHANCES. HAVE ALSO LOWERED MAXIMUM TEMPERATURES IN THE SOUTH WHERE EXTENSIVE CLOUD COVER WILL PERSIST THIS AFTERNOON. UPDATE ISSUED AT 948 AM EDT FRI MAR 29 2013 MESONET DATA SHOWING MEASURABLE RAIN HAS OCCURRED OVER MOST OF WESTERN KY AND AS FAR SOUTHEAST AS CUMBERLAND COUNTY. RAIN ALSO FALLING AS FAR NORTH AS EVV INDIANA. RADAR SHOWS MOVEMENT OF RAIN TO THE ESE...SO EXPECT NUMEROUS SHOWERS TO AFFECT THE FAR SOUTHWEST AND FAR SOUTHERN PART OF THE FORECAST AREA. THIS IS SUPPORTED BY SREF PROBABILITIES AND LATEST DATA FROM THE HRRR AND NAM. AS SUCH HAVE UPDATED NDFD AND ZFP TO INCREASE RAIN PROBABILITIES IN THE FAR SOUTHWEST AND FAR SOUTH TODAY. UPDATE ISSUED AT 740 AM EDT FRI MAR 29 2013 UPDATED THE FORECAST TO BETTER REFLECT CURRENT CONDITIONS AND MODEL TRENDS. ONLY MADE SOME SLIGHT CHANGES TO TEMPERATURES...DEW POINTS CLOUDS AND WINDS IN THE FIRST TWO PERIODS. THE REST OF THE FORECAST IS ON TRACK. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 308 AM EDT FRI MAR 29 2013 A WEAK WEATHER SYSTEM WILL BRING SOME LIGHT RAIN TO THE SOUTHWESTERN HALF OF EASTERN KENTUCKY TODAY. THIS SYSTEM IS A WARM FRONT WHICH WILL TRY MOVING INTO THE AREA BUT THEN BE PUSHED BACK TO THE SOUTH TONIGHT. THIS WILL MAKE FOR A DRY SATURDAY BEFORE THE NEXT SYSTEM STARTS PUSHING ITS WAY INTO THE AREA ON SATURDAY NIGHT. THE JURY IS OUT ABOUT HOW MUCH RAIN THE WEAK SYSTEM TODAY WILL BE ABLE TO PRODUCE. IT MAY BE A LOT OF CLOUDS AND SOME SPRINKLES...AT BEST AND JUST A COUPLE OF HUNDREDTHS OF AN INCH OF RAIN AT THE WORST. AS YOU MOVE TO THE NORTHEAST FROM WAYNE COUNTY...THE CHANCE FOR MEASURABLE RAIN DECREASES. EXPECTING HIGHS IN THE MID 50S TODAY AND THEN NEAR 60 ON SATURDAY AS SOME WARMER AIR WORKS ITS WAY INTO THE AREA. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 412 AM EDT FRI MAR 29 2013 THE GFS AND ECMWF ARE IN GOOD AGREEMENT THROUGH THE PERIOD. FOR THE LOCAL AREA THEY SHOW A WARM AIR ADVECTION REGIME DEVELOPING IN ADVANCE OF A COLD FRONT SATURDAY NIGHT...WITH THE COLD FRONT THEN PASSING THROUGH ON SUNDAY. THERE APPEARS TO BE A DECENT AMOUNT OF MOISTURE WHICH MAKES ITS WAY IN FROM THE GULF BEFORE THE FRONT ARRIVES...AND LIKELY POPS FROM GFS MEXMOS SEEM REASONABLE. MARGINAL DEEP INSTABILITY IS ALSO INDICATED...AND IS WORTH A MENTION OF A SLIGHT CHANCE OF THUNDER. ANY LINGERING PRECIP IN THE SOUTH AND EAST ASSOCIATED WITH THE COLD FRONT SHOULD EXIT MONDAY EVENING. HOWEVER...THERE IS ADDITIONAL POTENTIAL FOR MORE PRECIP TOWARD THE END OF THE NIGHT...ALBEIT SMALL. THE NAM SHOWS A WAVE PASSING TO OUR SOUTH AND GRAZING OUR AREA...WHILE THE GFS AND ECMWF ARE FURTHER SOUTH WITH IT. WITH THE NAM BEING THE ONLY MODEL THAT EVEN GETS PRECIP TO THE EDGE OF OUR AREA...WILL NOT BRING ANY PRECIP INTO THE LOCAL AREA WITH THIS SYSTEM. HOWEVER...ALL THREE MODELS SHOW ANOTHER COLD FRONT MOVING IN FROM THE NW TOWARD MONDAY MORNING. WHILE THEY KEEP THE DEEP MOISTURE WITH THE FRONT NEAR OR NORTH OF THE OHIO RIVER...CONFIDENCE IN TIMING IS NOT GOOD ENOUGH TO PRECLUDE PRECIP HERE...AND HAVE ALLOWED FOR A SLIGHT CHANCE IN THE NORTH AT DAWN. WILL USE CHANCE POPS FOR RAIN ON MONDAY AS THE FRONT MOVES THROUGH. HAVE RESERVED THE HIGHEST POPS WITH THIS FRONT...STILL IN CHANCE CATEGORY...FOR MONDAY NIGHT AS A WAVE MOVES ALONG THE FRONT AFTER IT HAS PASSED. UP UNTIL MONDAY THE PRECIP FORM SHOULD BE LIQUID...BUT ENOUGH COLD AIR ARRIVES TO THREATEN SNOW BEFORE POPS DROP OFF LATE MONDAY NIGHT. LARGE...COLD...SPRAWLING SURFACE HIGH PRESSURE THEN HEADS IN FROM THE NW AND IS EXPECTED TO BRING DRY WEATHER INTO THURSDAY. LOW PRESSURE PASSING WELL TO OUR SOUTH THURSDAY AND THURSDAY NIGHT LOOKS AT THIS POINT LIKE IT WILL GRAZE THE SOUTHERN PART OF THE FORECAST AREA WITH RAIN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 133 PM EDT FRI MAR 29 2013 VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. A WEAK WEATHER DISTURBANCE WILL BRING LIGHT RAIN TO THE EXTREME SOUTHERN PART OF THE FORECAST AREA THIS AFTERNOON...WELL SOUTH OF JKL...AND MAINLY SOUTH OF SME AND LOZ AS WELL. WHERE THE RAIN OCCURS LOCAL MVFR TO IFR CONDITIONS ARE POSSIBLE...MAINLY WITH LOWER VISIBILITIES. OUTSIDE OF THE RAIN AREA VFR CONDITIONS WILL PREVAIL TODAY. DEWPOINTS HAVE INCREASED IN THE FAR SOUTH TODAY...AND IF CLOUDS BREAK TONIGHT SOME FOG IS POSSIBLE. HOWEVER...AT THIS POINT EXPECT EXTENSIVE CLOUDINESS IN THE SOUTHERN PART OF THE FORECAST AREA TO LIMIT FOG FORMATION TONIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...JJ LONG TERM...HAL AVIATION...SBH
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
109 PM EDT FRI MAR 29 2013 ...Updated Aviation Discussion... .Short Term (Now - Saturday)... Issued at 300 AM EDT Fri Mar 29 2013 An upper level shortwave and weak sfc boundary were located to our WSW early this morning producing showers and t-storms from eastern KS to western KY. The latest RAP model guidance seems to be handling this area of precip quite well, so have relied on it for short term POPs. Rain showers look likely across portions of south central KY this morning before moving south of the area into TN this afternoon. Think that better lapse rates out west are producing the t-storms with this wave and do not anticipate those better lapse rates to translate eastward so will not include thunder in this forecast. For high temperatures today, have gone with mid 50s over southern Indiana and north central KY which will see less cloud cover overall and no precip. Lower 50s can be expected for highs over south central KY where rain is anticipated. Tonight sfc high pressure will quickly work in from the north allowing for dry conditions and only partly cloudy skies across southern IN and northern KY. Went with a decent temp gradient due to cloud cover with low to mid 30s for lows over southern IN/northern KY to upper 30s and lower 40s over south central KY. The next push of moisture doesn`t look to arrive until late Sat afternoon or evening as a warm front pushes into south central KY. Therefore, limited POP chances to just the afternoon hours over south central KY for Sat. The rest of the area should be dry and warm up quite nicely. With only partly cloudy skies anticipated during the morning and early afternoon, went with high temps in the low to mid 60s. .Long Term (Saturday Night - Thursday)... Issued at 300 AM EDT Fri Mar 29 2013 Cold front number one will be fast approaching from the northwest Saturday night. Rain and a few embedded rumbles of thunder will overspread the forecast area Saturday night and through the morning hours Sunday. Rain chances will diminish from west to east late Sunday morning, with a dry period anticipated from roughly Sunday afternoon through Sunday night. A second cold front will quickly enter the forecast area from the north Monday and sag south through Monday night. Expect rain chances to increase through the day Monday and rain should exit the southern CWA by Tuesday morning. Temperatures will fall behind the front Monday night and soundings indicate the potential for some smaller ice crystal growth. It appears the loss of moisture/ice crystals within the dendritic growth layer will limit large snowflake generation. So, there could be some light snow mixed with the rain overnight as the system exits. Then, high pressure will build across the Ohio Valley, with the active storm track being pushed well to our south. The only question is whether a southern track system Thursday will be deep enough to increase moisture and rain potential across the Ohio and Tennessee Valleys as it tracks across the Gulf States. Rain probabilities are low for Thursday, with an overall slower trend noted in latest guidance. Will go with a dry forecast Tuesday through Thursday, with perhaps a slight rain chance across our south and southeast CWA just beyond the long-term period. The cold front that swings through the area early Sunday will not be followed by a cold air mass. Still expect temperatures in the 60s Sunday afternoon. However, the passage of the second front on Monday will bring a return to unseasonably cool conditions through Thursday. The good news is temperatures appear to moderate some through the work week. So, while highs in the 40s are expected Tuesday, highs Thursday appear to reach the middle 50s. && .Aviation (18Z TAF Issuance)... Issued at 109 PM EDT Fri Mar 29 2013 Ceilings are the main challenge with this forecast package. Mesoscale models are showing MVFR clouds forming to our west early this afternoon and spreading eastward by mid and late afternoon, particularly over southern Kentucky. Recent obs show that some low stratus has indeed formed across southeast Missouri and southern Illinois. In southern Kentucky, GLW has started reporting a ceiling at 032. Will go ahead and bring an MVFR ceiling into BWG, but will keep it on the high side of MVFR -- above 2000 feet. Will monitor to see if we need to go lower. The rain at BWG should cease around 19Z. The northern TAF sites should stay VFR. Winds at all three sites will remain light and variable. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...NONE. KY...NONE. $$ Short Term.......AMS Long Term........MJP Aviation.........13
AREA FORECAST DISCUSSION
NWS JACKSON KY
1254 PM EDT FRI MAR 29 2013 .UPDATE... ISSUED AT 1253 PM EDT FRI MAR 29 2013 HAVE UPDATED NDFD AND ZFP FOR LATEST OBSERVATIONAL TRENDS. RAIN HAS MEASURED AT MONTICELLO AND IT HAS STARTED RAINING AT SME. MAIN CHANGES WERE TO REDUCE THE NORTHERN EXTENT OF ANY RAIN CHANCES. HAVE ALSO LOWERED MAXIMUM TEMPERATURES IN THE SOUTH WHERE EXTENSIVE CLOUD COVER WILL PERSIST THIS AFTERNOON. UPDATE ISSUED AT 948 AM EDT FRI MAR 29 2013 MESONET DATA SHOWING MEASURABLE RAIN HAS OCCURRED OVER MOST OF WESTERN KY AND AS FAR SOUTHEAST AS CUMBERLAND COUNTY. RAIN ALSO FALLING AS FAR NORTH AS EVV INDIANA. RADAR SHOWS MOVEMENT OF RAIN TO THE ESE...SO EXPECT NUMEROUS SHOWERS TO AFFECT THE FAR SOUTHWEST AND FAR SOUTHERN PART OF THE FORECAST AREA. THIS IS SUPPORTED BY SREF PROBABILITIES AND LATEST DATA FROM THE HRRR AND NAM. AS SUCH HAVE UPDATED NDFD AND ZFP TO INCREASE RAIN PROBABILITIES IN THE FAR SOUTHWEST AND FAR SOUTH TODAY. UPDATE ISSUED AT 740 AM EDT FRI MAR 29 2013 UPDATED THE FORECAST TO BETTER REFLECT CURRENT CONDITIONS AND MODEL TRENDS. ONLY MADE SOME SLIGHT CHANGES TO TEMPERATURES...DEW POINTS CLOUDS AND WINDS IN THE FIRST TWO PERIODS. THE REST OF THE FORECAST IS ON TRACK. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 308 AM EDT FRI MAR 29 2013 A WEAK WEATHER SYSTEM WILL BRING SOME LIGHT RAIN TO THE SOUTHWESTERN HALF OF EASTERN KENTUCKY TODAY. THIS SYSTEM IS A WARM FRONT WHICH WILL TRY MOVING INTO THE AREA BUT THEN BE PUSHED BACK TO THE SOUTH TONIGHT. THIS WILL MAKE FOR A DRY SATURDAY BEFORE THE NEXT SYSTEM STARTS PUSHING ITS WAY INTO THE AREA ON SATURDAY NIGHT. THE JURY IS OUT ABOUT HOW MUCH RAIN THE WEAK SYSTEM TODAY WILL BE ABLE TO PRODUCE. IT MAY BE A LOT OF CLOUDS AND SOME SPRINKLES...AT BEST AND JUST A COUPLE OF HUNDREDTHS OF AN INCH OF RAIN AT THE WORST. AS YOU MOVE TO THE NORTHEAST FROM WAYNE COUNTY...THE CHANCE FOR MEASURABLE RAIN DECREASES. EXPECTING HIGHS IN THE MID 50S TODAY AND THEN NEAR 60 ON SATURDAY AS SOME WARMER AIR WORKS ITS WAY INTO THE AREA. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 412 AM EDT FRI MAR 29 2013 THE GFS AND ECMWF ARE IN GOOD AGREEMENT THROUGH THE PERIOD. FOR THE LOCAL AREA THEY SHOW A WARM AIR ADVECTION REGIME DEVELOPING IN ADVANCE OF A COLD FRONT SATURDAY NIGHT...WITH THE COLD FRONT THEN PASSING THROUGH ON SUNDAY. THERE APPEARS TO BE A DECENT AMOUNT OF MOISTURE WHICH MAKES ITS WAY IN FROM THE GULF BEFORE THE FRONT ARRIVES...AND LIKELY POPS FROM GFS MEXMOS SEEM REASONABLE. MARGINAL DEEP INSTABILITY IS ALSO INDICATED...AND IS WORTH A MENTION OF A SLIGHT CHANCE OF THUNDER. ANY LINGERING PRECIP IN THE SOUTH AND EAST ASSOCIATED WITH THE COLD FRONT SHOULD EXIT MONDAY EVENING. HOWEVER...THERE IS ADDITIONAL POTENTIAL FOR MORE PRECIP TOWARD THE END OF THE NIGHT...ALBEIT SMALL. THE NAM SHOWS A WAVE PASSING TO OUR SOUTH AND GRAZING OUR AREA...WHILE THE GFS AND ECMWF ARE FURTHER SOUTH WITH IT. WITH THE NAM BEING THE ONLY MODEL THAT EVEN GETS PRECIP TO THE EDGE OF OUR AREA...WILL NOT BRING ANY PRECIP INTO THE LOCAL AREA WITH THIS SYSTEM. HOWEVER...ALL THREE MODELS SHOW ANOTHER COLD FRONT MOVING IN FROM THE NW TOWARD MONDAY MORNING. WHILE THEY KEEP THE DEEP MOISTURE WITH THE FRONT NEAR OR NORTH OF THE OHIO RIVER...CONFIDENCE IN TIMING IS NOT GOOD ENOUGH TO PRECLUDE PRECIP HERE...AND HAVE ALLOWED FOR A SLIGHT CHANCE IN THE NORTH AT DAWN. WILL USE CHANCE POPS FOR RAIN ON MONDAY AS THE FRONT MOVES THROUGH. HAVE RESERVED THE HIGHEST POPS WITH THIS FRONT...STILL IN CHANCE CATEGORY...FOR MONDAY NIGHT AS A WAVE MOVES ALONG THE FRONT AFTER IT HAS PASSED. UP UNTIL MONDAY THE PRECIP FORM SHOULD BE LIQUID...BUT ENOUGH COLD AIR ARRIVES TO THREATEN SNOW BEFORE POPS DROP OFF LATE MONDAY NIGHT. LARGE...COLD...SPRAWLING SURFACE HIGH PRESSURE THEN HEADS IN FROM THE NW AND IS EXPECTED TO BRING DRY WEATHER INTO THURSDAY. LOW PRESSURE PASSING WELL TO OUR SOUTH THURSDAY AND THURSDAY NIGHT LOOKS AT THIS POINT LIKE IT WILL GRAZE THE SOUTHERN PART OF THE FORECAST AREA WITH RAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 740 AM EDT FRI MAR 29 2013 VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. HIGH CLOUDS AND MIDDLE CLOUDS HAVE ARRIVED AND WILL BE LOWERING THROUGH THE DAY TODAY. ISOLATED LIGHT SHOWER POSSIBLE BY MID DAY IN THE CUMBERLAND VALLEY. MAINTAINED A VCSH AND CIGS AROUND 5K FEET FOR THIS IN THE LOZ AND SME TAFS. WINDS WILL HAVE A W TO WNW TENDENCY...AT 5 KTS OR LESS THROUGH THE PERIOD AS WELL. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...JJ LONG TERM...HAL AVIATION...JJ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
130 PM EDT FRI MAR 29 2013 .SYNOPSIS... ISSUED AT 329 AM EDT FRI MAR 29 2013 HIGH PRESSURE WILL ADVANCE FROM THE UPPER MIDWEST THROUGH THE GREAT LAKES TO ROUND OUT TODAY. THIS PATTERN WILL BRING SUNSHINE THROUGH THE FIRST HALF OF SATURDAY. TEMPERATURES WILL ALSO FINALLY...ALTHOUGH BRIEFLY...WARM ABOVE NORMAL FOR THE FIRST HALF OF THE WEEKEND. THAT TREND WILL BE SHORT LIVED...AS A STRONG COLD FRONT ARRIVES SATURDAY NIGHT...WITH A ROUND OF RAIN OR SNOW SHOWERS LIKELY. AS THE FRONT PASSES...MUCH COLDER WEATHER WILL ARRIVE LATER SUNDAY AND STICK AROUND THROUGH AT LEAST TUESDAY...WITH PERIODIC LAKE EFFECT SNOW SHOWERS AND WINDY CONDITIONS. && .UPDATE... ISSUED AT 129 PM EDT FRI MAR 29 2013 STRATUS IS GONE OVER EASTERN UPPER. A FEW CU HAVE FIRED SOUTH OF CAD/HTL...AND INLAND OF OSC/TAWAS...OTHERWISE SKIES ARE CLEAR. OSC BRIEFLY TWEAKED UP TO 47F...BUT A LAKE BREEZE HAS BROUGHT THEM BACK TO EARTH. MOST SITES NEAR 40S TO THE MID 40S...SOME OF THE MORE MARITIME LOCALES STILL STUCK IN THE 30S. NO MAJOR CHANGES MADE. UPDATE ISSUED AT 959 AM EDT FRI MAR 29 2013 PATCHY STRATUS CONTINUES IN EASTERN CHIPPEWA CO AND OVER WHITEFISH BAY...THOUGH HAS BROKEN UP SOMEWHAT OVER THE SAULTS PROPER. THE STRATUS SHOULD ERODE AND MIX OUT OVER THE NEXT 3 HOURS. TEMPS HAVE REBOUNDED INTO THE MID 20S TO MID 30S...DO NOT PLAN ON ANY SIGNIFICANT CHANGES TO THE MAX TEMP FORECAST. UPDATE ISSUED AT 613 AM EDT FRI MAR 29 2013 CHANGES THIS HOUR: COULDN/T QUITE GET THROUGH THE OVERNIGHT WITHOUT DEALING WITH SOME STRATUS. A PATCH HAS POPPED UP OVER THE PAST HOUR FROM KANJ NORTH INTO THE HIGH TERRAIN EAST OF WHITEFISH BAY ACROSS THE BORDER IN ONTARIO. NEAR TERM RUC PROGS SUGGEST THAT SOMEWHAT ENHANCED H9 MOISTURE FROM THIS AREA EAST WILL MOVE EAST AND AWAY FROM THE REGION THIS MORNING. DON/T EXPECT THIS TO GET TOO OUT OF HAND/WIDESPREAD...BUT WILL CARRY SOME ADDITIONAL CLOUDINESS THROUGH THE NEXT FEW HOURS AS EARLY MORNING INVERSION WILL ALLOW ANYTHING THAT DEVELOPS TO PERSIST FOR A TIME. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 329 AM EDT FRI MAR 29 2013 HIGH IMPACT WEATHER POTENTIAL: NONE. OVERVIEW: EARLY MORNING WATER VAPOR IMAGERY REVEALS RECENT BLOCKING OVER EASTERN CANADA RETREATING EAST AS BROAD NORTHWEST FLOW BEGINS TO TAKE OVER ALOFT ACROSS THE GREAT LAKES REGION. THE CLOSED HIGH ASSOCIATED WITH THIS BLOCK HAS OPENED UP...AND WAS OVERHEAD AS SHORTWAVE RIDGING YESTERDAY AND HAS NOW PUSHED INTO THE NORTHEASTERN CONUS AS OF THIS MORNING. MOVING DOWN TO THE SURFACE...A MODEST SURFACE RIDGE AXIS IS DRAPED FROM JUST WEST OF THE WESTERN LAKES INTO INDIANA/KENTUCKY...WHICH HAS PROVIDED CALM/QUIET WEATHER ACROSS THE GREAT LAKES REGION. 00Z APX RAOB SHOWED -4C AT H8...JUST ABOUT NORMAL FOR THIS TIME OF YEAR WITH OUR AVERAGE TEMPERATURE FOR THE DATE YESTERDAY SIMILARLY CLOSE TO NORMAL. WITH THIS HIGH OVERHEAD AND THE MAJORITY OF ANY JET ENERGY RESIDING OVER THE SOUTHEASTERN STATES...THE WEATHER LOOKS QUIET THROUGH THE SHORT TERM PORTION OF THE FORECAST...BUT THE AFOREMENTIONED BREAKING DOWN OF THE BLOCK OVER CANADA PORTENDS THAT THIS QUIET STRETCH OF WEATHER WILL BE COMING TO AN END SOON...SO DON/T GET USED TO WHAT YOU SEE TODAY! THROUGH DAYBREAK: TERRIFIC RADIATIONAL COOLING CONDITIONS ALLOWING SOME SPOTS TO REACH 20F AS OF THIS WRITING...WITH A WEAK WIND KEEPING SOME HIGHER TERRAIN SPOTS AS WELL AS THE NE LOWER COAST IN THE UPPER 20S TO AROUND 30 UNDER CLEAR SKIES. LITTLE CHANGE THROUGH DAYBREAK...WITH SOME LOCAL SLICK SPOTS LIKELY AS AFTERNOON PUDDLES REFREEZE. TODAY: WEAK SHORTWAVE TROUGH NOW EXITING TO THE SOUTHEAST OF THE REGION WILL ALLOW FOR GRADUALLY BUILDING MID LEVEL HEIGHTS /ALONG WITH MID LEVEL NVA/ TODAY WITH THE RIDGE OF SURFACE HIGH PRESSURE SLIDING EAST INTO THE REGION. LLEVEL TRAJECTORIES SHOW TODAY/S AIRMASS ARRIVING FROM WESTERN ONTARIO 24 HOURS PREVIOUSLY...AND A LOOK AT YESTERDAY/S CONDITIONS THERE SHOW NO CUMULUS DEVELOPMENT /DEWPOINTS FALLING INTO THE LOWER-MID TEENS/ ALONG WITH LOWER 40S FOR HIGHS. GIVEN THE OVERHEAD HIGH PRESSURE AND NVA...WILL ALLOW FOR SOME WARMING TO THIS AIRMASS THROUGH SUBSIDENCE WHICH SUGGESTS TRENDING TOWARDS THE WARMER ECMWF-MOS GUIDANCE TODAY...YIELDING HIGHS IN THE MID-UPPER 40S MOST LOCATIONS UNDER SUNNY SKIES... WARMEST SOUTHEASTERN AREAS WHERE LAKE INFLUENCE ON TEMPS WILL BE LESS. TONIGHT: HIGH PRESSURE SETTLES OVERHEAD WITH SHORT-WAVE RIDGING CONTINUING/SHARPENING AT MID LEVELS IN RESPONSE TO OUR NEXT WEATHER MAKER DROPPING SOUTH OUT OF CENTRAL CANADA. THIS WILL LIKELY SPREAD SOME HIGH CLOUDINESS INTO THE REGION AFTER MIDNIGHT...BUT FOR THE MOST PART EXPECT ANOTHER CALM/CLEAR/QUIET NIGHT WITH TERRIFIC RADIATIONAL COOLING CONDITIONS YET AGAIN. AFTERNOON CROSSOVER TEMPS WILL LIKELY BE IN THE LOWER-MIDDLE TEENS...SO LOWS SHOULD HAVE NO PROBLEM FALLING INTO THE MIDDLE-UPPER TEENS IN THE COLD SPOTS YET AGAIN WITH LOWS GENERALLY IN THE LOWER 20S ELSEWHERE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 AM EDT FRI MAR 29 2013 SATURDAY...AS THE SFC HIGH MOVES EAST, THE COLD FRONT FROM THE WEST BEARS DOWN ON THE FORECAST AREA. AIDING THE COLD FRONT IS THE 500 MB SHORTWAVE TROUGH THAT IS CHASING THE RIDGE EAST AS WELL. THE MORNING LOOKS TO REMAIN DRY AS THE MOISTURE AT 850 MB AND IN THE 700-500 MB LAYER TAKES UNTIL AROUND 18Z TO BEGIN GETTING MOIST ENOUGH TO SUPPORT PRECIPITATION. THE PROFILE WOULD SUGGEST THAT THE PRECIPITATION WOULD BE ALL RAIN THROUGH 00Z. SATURDAY NIGHT...MOISTURE CONTINUES OVER THE REGION AND THE PROFILES BEGIN TO MOVE TOWARD 0C SO THAT THERE WILL BE A MIX IN E UPPER AND PROBABLY RAIN IN N LOWER. THE PROFILES DON`T CHANGE MUCH OVERNIGHT SO THAT A MIX IS WHAT WILL BE EXPECTED. ALSO, THE 700-500 MB LAYER BEGINS TO DRY OUT SIGNIFICANTLY ENOUGH THAT IT MAY STOP PRECIPITATING. SO WILL GO WITH THE CHANCE POPS IN E UPPER AND OVER LAKE MICHIGAN. STILL LOTS OF MOISTURE OVER N LOWER AND LAKE HURON TO CONTINUE THE LIKELY POPS. SUNDAY...THE MOISTURE CONTINUES TO MOVE EAST, WITH COLD AIR SPILLING INTO THE FORECAST AREA. AS THE COLD AIR MOVES IN THE MOISTURE BEGINS TO MOVE INTO THE REGION WITH SATURATION REACHING -10C. THIS GETS THE LIGHT SNOW/FLURRIES STARTED AS THE STABILITY BEGINS TO DECREASE AND UNDER THE 500 MB LOW AND SHORTWAVES ROTATING AROUND IT. OVERNIGHT, THE 850 MB TEMPERATURES FALL TO AROUND -13C ON THE ECMWF BY 12Z. THE GFS IS SIGNIFICANTLY COLDER (-17C) AND WOULD PRODUCE LES FAIRLY WELL WITH THE 500 MB LOW. WILL HEDGE PESSIMISTIC AS THIS SEASON HAS REMAINED COLDER THAN FIRST THOUGHT. EXTENDED (MONDAY THROUGH THURSDAY)...MONDAY, LOOKS LIKE THE TEMPERATURES FALL ENOUGH TO HAVE LES ON BOTH MODELS AS THE ECMWF HAS -14C AT 850 MB BY 00Z. EARLIER IN THE WEEK, THE WINDS LOOKED STRONGER, NOW IT LOOKS BREEZY. WILL CONTINUE THE GUSTY WINDS IN THE HWO. TUESDAY, AS THE SFC HIGH BEGINS TO MOVE INTO THE REGION, THE 850 MB TEMPERATURES BEGIN TO WARM SLIGHTLY, JUST ENOUGH THAT WE MAY LOSE THE INSTABILITY NEEDED FOR THE LES. THIS CONTINUES INTO THE NIGHT SO WOULD EXPECT THAT THE SNOW WOULD STOP. 00Z ECMWF SAYS THAT IT SHOULD. WEDNESDAY, HIGH PRESSURE AT THE SFC AND 500 MB RIDGE MOVES THROUGH THE REGION SO THAT WE WILL REMAIN DRY FOR THE DAY. OVERNIGHT, THE ANOTHER COLD FRONT AND 500 MB SHORTWAVE TROUGH MOVE THROUGH THE REGION. ONE SOLUTION IS WARM ENOUGH FOR RAIN AND ONE COLD ENOUGH FOR SNOW. SO WILL GO WITH A MIX AT THIS POINT. THURSDAY, THINK THAT THE GFS IS A LITTLE TOO WET AT 850 MB AND THINK THAT THE THE ECMWF HAS THE RIGHT IDEA, THAT IS IT IS IN LINE WITH THE CURRENT FORECAST SO WILL CONTINUE THE DRY DAY AND NIGHT AT HIGH PRESSURE BEGINS TO BUILD INTO THE REGION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 129 PM EDT FRI MAR 29 2013 VFR. CLOUDS INCREASING ON SATURDAY. HIGH PRESSURE OVER THE PRESSURE PROVIDING NEARLY CLEAR SKIES THIS AFTERNOON AND MOST OF TONIGHT. THE HIGH MOVES EAST TONIGHT AND MORE RAPIDLY SO ON SATURDAY...ALLOWING CLOUDS TO FILTER IN FROM THE WEST. ANY PRECIP THREAT WILL WAIT UNTIL AFTER 18Z SATURDAY. LIGHT NW WINDS TODAY...INTERRUPTED BY LAKE BREEZES. LIGHT WINDS TONIGHT...SOUTHERLY WINDS SATURDAY. && .MARINE... ISSUED AT 329 AM EDT FRI MAR 29 2013 SUMMARY: HIGH PRESSURE WILL REMAIN IN CONTROL OF THE REGION/S WEATHER THROUGH SATURDAY WITH QUIET CONDITIONS OVER THE LAKES. A COLD FRONT WILL APPROACH SUNDAY...BRINGING STRENGTHENING SOUTHERLY WINDS. IN IT/S WAKE...NORTHWEST WINDS WILL DEVELOP AND STRENGTHEN SUNDAY NIGHT INTO MONDAY WITH STRONG WINDS CONTINUING THROUGH TUESDAY BEFORE HIGH PRESSURE BUILDS INTO THE GREAT LAKES REGION FROM THE WEST. HEADLINE POTENTIAL: SMALL CRAFT POTENTIAL UNDER SOUTHERLY FLOW SATURDAY WITH A PROLONGED PERIOD OF SMALL CRAFT WINDS DEVELOPING BEHIND A STRONG COLD FRONT SUNDAY NIGHT AND CONTINUING THROUGH NEXT TUESDAY. THERE IS SOME POTENTIAL FOR LOW-END GALE FORCE WINDS IN THE MONDAY-TUESDAY TIMEFRAME FOR NW FLOW FAVORED AREAS /NEAR WHITEFISH POINT AND ALONG THE LAKE HURON COAST FROM THE BRIDGE SOUTHEAST TO PRESQUE ISLE LIGHT/. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...JZ SYNOPSIS...JL SHORT TERM...ARNOTT LONG TERM...JL AVIATION...JZ MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
318 PM CDT FRI MAR 29 2013 .SYNOPSIS... ISSUED AT 318 PM CDT FRI MAR 29 2013 H5 HAND ANALYSIS THIS MORNING IS INDICATING BROAD LOW AMPLITUDE FLOW ACROSS THE LOWER 48...WITH EMBEDDED SHORTWAVES NOTED OVER THE NORTHERN ROCKIES OF IDAHO AND MONTANA. ABUNDANT MID LEVEL INSTABILITY AND MID LEVEL ALTO CU HAS TRACKED INTO WESTERN AND CENTRAL NEBRASKA THIS MORNING...WITH RADAR INDICATING HIGHLY ELEVATED SHOWERS...NONE OF WHICH IS REACHING THE GROUND ATTM. AT THE SURFACE...A LEE SIDE TROUGH HAS BEGUN TO DEEPEN ACROSS THE PANHANDLE AND FAR EASTERN COLORADO OVER THE PAST COUPLE OF HOURS. THIS HAS RESULTED IN INCREASED SRLY WINDS THIS AFTERNOON AND INCREASED LOW LEVEL MOISTURE...WITH DEW POINTS BEGINNING TO REACH INTO THE LOWER 40S AS OF 3 PM CDT. TEMPERATURES AS OF 3 PM CDT RANGED FROM 64 DEGREES AT VALENTINE TO 71 DEGREES AT OGALLALA. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 318 PM CDT FRI MAR 29 2013 MAIN FORECASTING CHALLENGES OVER THE NEXT 24 HOURS ARE THUNDERSTORM POTENTIAL AND ASSOCIATED PRECIPITATION CHANCES TONIGHT...THEN LOW PRECIPITATION CHANCES FOR SATURDAY...IN PARTICULAR SATURDAY AFTERNOON. FOR TONIGHT...AM EXPECTING SOME ISOLATED TSRA INITIATION INVOF OF SURFACE TROUGH AXIS LATER THIS AFTERNOON. BASED ON THE LATEST NAM AND RUC SOLNS...THIS SHOULD BE SOMEWHERE FROM AROUND OGALLALA TO NORTHERN CHERRY COUNTY BY 21Z THIS AFTERNOON. AM EXPECTING ISOLATED CONVECTION TO FIRE INVOF OF THIS FEATURE DURING THE 21Z TO 00Z TIME FRAME LATER THIS AFTERNOON. DECENT MID LEVEL FLOW...WILL TRACK ANY ISOLATED CONVECTION QUICKLY EAST INTO THE CENTRAL AND EASTERN CWFA LATER THIS EVENING AND OVERNIGHT. CONVECTION IS EXPECTED TO BECOME BETTER ORGANIZED IN THE EASTERN CWFA OVERNIGHT AS A NICE LOW LEVEL JET PUSHES NORTH INTO EASTERN NEBR...THE NOSE OF WHICH PUSHES INTO OUR NERN ZONES. FOR PRECIPITATION CHANCES TONIGHT...FAVORED POPS AROUND 20 PERCENT...ALONG AND WEST OF HIGHWAY 83...INCREASING THEM EASTWARD TO AROUND 50 PERCENT IN THE NERN CWA. AS FOR THE THREAT OF SEVERE THUNDERSTORMS TONIGHT...THE LATEST SWODY1 HAS A SEE TEXT ACROSS OUR SWRN ZONES AND CENTRAL SANDHILLS MAINLY FOR EARLY EVENING CONVECTION TIED TO PEAK HEATING. AT THIS JUNCTURE...SOME GUSTY WINDS MAY ACCOMPANY THE STRONGEST STORMS GIVEN THE DRY CONDS BLO 10000 FT AGL AND EXPECTED HIGH BASED TSRAS IN THE WEST. EVEN IN LIGHT OF WET BULB ZEROES OF AROUND 9000 FT MSL...LARGE HAIL THREAT WILL BE MINIMAL AS DEEP LAYER SHEAR IS ONLY AROUND 30 KTS AND FREEZING LEVELS ARE AROUND 5 TO 7 THOUSAND FT AGL. FOR SATURDAY...NORTHWESTERLY WINDS WILL DEVELOP BEHIND EXITING LOW PRESSURE AND MAY BECOME GUSTY DURING THE AFTERNOON HOURS. WITH SURFACE HEATING...MID LEVEL LAPSE RATES WILL STEEPEN SIGNIFICANTLY DURING THE AFTERNOON HOURS...AND WILL CONTINUE MENTION OF ISOLATED SHOWERS. LI`S ARE BARELY NEGATIVE TOMORROW AFTERNOON AND WILL FORGO MENTION OF THUNDER ATTM. HIGHS SATURDAY WILL BE COOLER THAN TDYS READINGS. BASED ON H85 TEMPS AND GOOD MIXING...HIGHS WILL RANGE FROM THE 50S NORTH...TO THE LOWER 60S IN THE SOUTH. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 318 PM CDT FRI MAR 29 2013 SATURDAY NIGHT WILL SEE A DISTURBANCE PUSHING SOUTH AND AN ARCTIC COLD FRONT DIPPING SOUTH ACROSS THE NORTHERN PLAINS. BY SUNDAY AFTERNOON THE COLD FRONT WILL BE PUSHING INTO NRN NEBRASKA. SHOULD SQUEAK OUT ANOTHER NICE DAY WITH HIGHS IN THE 60S FOR MOST OF THE CWA. PORTIONS OF NORTH CENTRAL WILL SEE HIGHS ONLY IN THE 50S AS THE COLD FRONT ARRIVES BEFORE PEAK HEAT. ALSO GOING TO SEE SOME SHOWERS DEVELOP ALONG/AHEAD OF THE FRONT...MAINLY WHERE THERE IS BETTER MOISTURE TO THE EAST. BY SUNDAY NIGHT COLD AIR WILL PUSH ACROSS THE AREA. NOT A GREAT CHANCE FOR PRECIP...BUT COLD AIR ALOFT WILL CREATE SOME STEEP LAPSE RATES. ALSO AS TEMPS FALL A MIX OR CHANGE TO SNOW CAN BE EXPECTED. MONDAY WILL FEEL THE COLD ARCTIC AIR AS HIGHS ONLY WARM INTO THE MID 30S TO MID 40S. PRECIP WILL BE PUSHING SOUTH...SO HIGHS MAY ACTUALLY BE ABLE TO WARM UP A LITTLE MORE THAN FORECAST AS APRIL SUNSHINE ARRIVES FOR THE AFTERNOON. COLD AIR IS SHORT LIVED AS CENTER OF HIGH SHIFTS TO THE EAST FOR TUESDAY...WITH RETURN SOUTHERLY FLOW BY TUESDAY AFTERNOON. NOT A FAST REBOUND ON TUESDAY AS HIGHS ONLY IN THE 40S TO LOW 50S. WEDNESDAY INTO THURSDAY WILL CONTINUE TO SEE A REBOUND OF TEMPS. SURF HIGH CONTINUES TO PUSH TO THE SE WITH MORE WARM AIR TO PUSH NORTHWARD AND THE BACKSIDE OF THE HIGH. 850 MB TEMPS PUSH INTO THE SINGLE DIGITS ABOVE ZERO AND CLOSE TO 10 IN THE WEST WITH GUIDANCE CLOSE TO 60. PRECIP CHANCES DO NOT LOOK GOOD THROUGH THE WEEK...AS GULF MOISTURE REMAINS SHUT OFF AND MODELS CONTINUE A DRY BL. AN UPPER LEVEL DISTURBANCE LATE IN THE WEEK MAY BRING SOME LIGHT PRECIP...BUT WILL HAVE TO BE A TOP DOWN SATURATION AND DO NOT HAVE IN THE FORECAST ATTM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1250 CDT FRI MAR 29 2013 GENERALLY VRF CONDITIONS THE NEXT 24 HOURS. TROUGH MOVING ACROSS THE AREA THIS EVENING. WEAK INSTABILITY SHOULD BE ENOUGH FOR ISOLD TO SCT THUNDERSTORM DEVELOPMENT. DEVELOPMENT IS EXPECTED ACROSS WESTERN NEBRASKA AROUND 22Z TO 23Z AND PROGRESS EASTWARD. AM EXPECTING IMPACT AT BOTH TERMINALS...KLBF AND KVTN...HOWEVER DURATION WILL NOT BE LONG. COULD SEE A BRIEF REDUCTION TO MVFR VSBY...HOWEVER THE THUNDER WILL BE THE MAIN CONCERN. BY 01Z THE STORMS SHOULD BE EAST OF THE TERMINALS. WINDS TODAY WILL BE SOUTHERLY...BECOMING NORTHWESTERLY OVERNIGHT...BEHIND THE TROUGH. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...CLB LONG TERM...MASEK AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1244 PM CDT FRI MAR 29 2013 .AVIATION... 18Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST 04Z THEN ARE EXPECTED TO DETERIORATE AS AN AREA OF SHOWERS DEVELOPS TO THE WEST AND DRIFTS SOUTHEAST AHEAD OF AN APPROCHING COLD FRONT. A FEW ISOLATED THUNDERSTORMS ARE POSSIBLE BUT WILL LEAVE THE MENTION OUT OF THE TAFS FOR NOW WITH ANOTHER MAIN TAF ISSUANCE BETWEEN NOW AND THE TIME ANY DEVELOPMENT WOULD OCCUR. CIGS MAY DROP TO MVFR OR EVEN AS LOW AS IFR IN THE SHOWERS. SFC WINDS WILL TURN TO THE NORTHWEST AROUND 12Z AS THE SFC COLD FRONT PUSHES ACROSS THE SITES. && .PREV DISCUSSION... /ISSUED 340 AM CDT FRI MAR 29 2013/ SHORT TERM...TODAY THROUGH SATURDAY NIGHT. THE MAIN FORECAST CONCERNS IN THIS PERIOD ARE CHANCES FOR SHOWERS/ THUNDERSTORMS AND TEMPERATURES. TEMPERATURES YESTERDAY TOPPED OUT MAINLY IN THE UPPER 50S AND LOWER 60S ACROSS THE FORECAST AREA. HIGHS TODAY SHOULD BE ABOUT 3 TO 5 DEGREES WARMER...BASED ON A SMALL INCREASE IN 850 MB TEMPS. THERE IS SOME CONCERN THAT PCPN COULD DEVELOP LATE THIS AFTERNOON AS LOW LEVEL MOISTURE AND INSTABILITY INCREASE. BUT BASED ON MOST RECENT FORECASTS OF MOST UNSTABLE CAPE FORECASTS FROM RAP MODEL...KEPT THINGS DRY UNTIL THIS EVENING. 850 MB DEWPOINTS WERE IN THE 5 TO 10 DEGREE CELSIUS RANGE LAST EVENING ACROSS THE SOUTHERN PLAINS... MAINLY FROM OKLAHOMA SOUTH. MODEL SHOW MOISTURE INCREASING IN OUR AREA...BUT MAIN AXIS STAYS MAINLY TO OUR WEST IN CENTRAL NEBRASKA THROUGH 00Z THIS EVENING. THIS 850 MB MOISTURE SHOULD SPREAD OVER OUR AREA TONIGHT AND THEN OUT OF THE AREA SATURDAY. KEPT FAIRLY HIGH POPS GOING FOR TONIGHT AND SATURDAY MORNING. SOME OF THE MODEL QPFS LOOK A LITTLE HIGH...BUT CERTAINLY AMOUNTS BETWEEN A TENTH AND A QUARTER OF AN INCH SEEM REASONABLE...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. COMBINATION OF CLOUD COVER AND WIND SHOULD HELP KEEP LOWS TONIGHT IN THE 40S MOST SPOTS. ON SATURDAY...A WIND SHIFT WILL MOVE ACROSS THE AREA...BUT 850 MB TEMPERATURES DO NOT CHANGE MUCH AND MIXING SHOULD BE GOOD. STAYED FAIRLY CLOSE TO PREVIOUS FORECAST FOR HIGHS SATURDAY...RANGING FROM UPPER 50S NORTH TO MID OR UPPER 60S FAR SOUTH. IF CLOUDS AND PCPN CLEAR OUT FASTER THAN CURRENTLY EXPECTED...HIGHS COULD BE A LITTLE WARMER NORTHERN AND CENTRAL ZONES. SATURDAY NIGHT WE ARE BETWEEN SYSTEMS AND FOR NOW KEPT THINGS DRY. SOME SHOWERS COULD DEVELOP TO OUR WEST IN THE AFTERNOON BUT FOR NOW EXPECTED THESE TO DISSIPATE SATURDAY EVENING BEFORE REACHING SOUTHEAST NEBRASKA. LOWS WILL DROP INTO THE 30S SATURDAY NIGHT. MILLER LONG TERM...SUNDAY THROUGH THURSDAY. MAIN CONCERNS IN THIS PERIOD ARE TEMPERATURES SUNDAY AND PCPN CHANCES FOR SUNDAY INTO SUNDAY NIGHT. A STRONG COLD FRONT WILL BE PUSHING INTO OUR NORTHERN ZONES SUNDAY AFTERNOON...SO JUST HOW WARM IT WILL GET IS PROBLEMATIC. AIRMASS WILL BE STARTING OUT QUITE MILD...BUT TEMPERATURES SHOULD BE FALLING IN THE AFTERNOON ACROSS NORTHEAST NEBRASKA AS WINDS SHIFT TO THE NORTH. WENT WITH HIGHS CLOSE TO NOON NORTH IN THE 50S...BUT IN THE 60S MID OR LATE AFTERNOON SOUTH. BUT AGAIN THIS WILL DEPEND ON FRONTAL TIMING. AREAS ALONG THE KANSAS BORDER COULD APPROACH 70...BUT DID NOT WANT TO GET TOO OPTIMISTIC AT THIS POINT. FAIRLY DECENT FORCING IS EXPECTED ALONG AND BEHIND THE FRONT...SO KEPT POPS 20 TO 30 PERCENT MOST AREAS SUNDAY AFTERNOON. PCPN TYPE WILL BE AN ISSUE AS THE COLD AIR POURS IN FOR SUNDAY NIGHT...WITH RAIN CHANGING TO SNOW. TRIED TO ADD SOME DETAIL TO PCPN TYPE SUNDAY NIGHT BUT THIS WILL BE REFINED AS WE GET CLOSER. DID NOT MENTION ANY SNOW ACCUMULATION AT THIS POINT...BUT THAT WILL NEED TO BE MONITORED CLOSELY. HIGHS MONDAY SHOULD ONLY REACH THE 30S...BUT THEN LOOK FOR MODERATING TEMPERATURES THROUGH THURSDAY AS MILDER AIR MOVES IN FROM THE SOUTH AND WEST. MILLER && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
704 PM EDT FRI MAR 29 2013 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE COLD FRONT WILL SHIFT SOUTHEASTWARD ACROSS THE NORTH COUNTRY DURING THE LATE AFTERNOON AND EVENING HOURS...BRINGING SCATTERED RAIN SHOWERS AND HIGHER ELEVATION SNOW SHOWERS. PRECIPITATION WILL END DURING THE PRE-DAWN HOURS SATURDAY. SURFACE HIGH PRESSURE BUILDS INTO THE NORTH COUNTRY DURING SATURDAY BRINGING MOSTLY SUNNY SKIES AND VALLEY TEMPERATURES IN THE UPPER 40S TO LOWER 50S. CLOUDS WILL INCREASE DURING SUNDAY...WITH THE NEXT FRONTAL SYSTEM BRINGING RAIN LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. && .NEAR TERM /UNTIL 7 AM SATURDAY MORNING/... AS OF 651 PM EDT FRIDAY...RECENT COMPOSITE RADAR IMAGERY SHOWS AN OVERALL DECREASE IN COVERAGE OF INSTABILITY RAIN/MTN SNOW SHOWERS ACROSS THE NORTH COUNTRY LATE THIS AFTERNOON. WATER VAPOR IMAGERY AND RAP OBJECTIVE ANALYSES SUGGEST THE THE WEAK SHORTWAVE DISTURBANCE IN NORTHWEST FLOW ALOFT AND ITS ASSOCIATED COLD POCKET OF AIR IN LOW/MID-LEVELS IS CURRENTLY PUSHING INTO SOUTHERN NEW ENGLAND...WITH DRIER SUBSIDENT FLOW ENTERING INTO THE SAINT LAWRENCE VALLEY. COMBINATION OF LOSS OF DAYTIME HEATING AND THE CONTINUED SOUTHEASTWARD MOVEMENT OF THE SHORTWAVE TROUGH SHOULD CONTINUE TO RESULT IN A DECREASE IN RAIN/SNOW SHOWER COVERAGE AND SKY COVER OVER THE NEXT FEW HOURS. BY LATE EVENING...WOULD EXPECT THAT ANY SHOWER ACTIVITY WOULD HAVE ENDED. MAINLY DRY FORECAST WITH SKIES CONTINUING TO CLEAR OUT DURING THE OVERNIGHT. THERE COULD BE A FEW SHELTERED VALLEYS AND HOLLOWS THAT MAY SEE SOME GROUND FOG/MIST BUT WILL LEAVE OUT OF THE FORECAST FOR NOW DUE TO THE LIMITED EXTENT OF ANY MIST/FOG. NO CHANGES TO LOW TEMPERATURES FOR THIS EVENING...GENERALLY IN THE 20S TO LOWER 30S. PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 337 PM EDT FOLLOWS... MARGINALLY UNSTABLE AIR MASS IN PLACE LATE THIS AFTERNOON (RAP- BASED LAPS ANALYSIS SHOWS SBCAPE VALUES AROUND 100 J/KG AT 19Z) WITH TEMPS IN THE UPR 40S IN THE VALLEYS. WEAK UPR TROUGH AND ASSOCIATED SFC COLD FRONT ACROSS THE ST. LAWRENCE VALLEY WILL TRANSLATE STEADILY SEWD ACROSS THE NORTH COUNTRY THIS EVENING...AND ASSOCIATED WEAK SYNOPTIC ASCENT AND INSTABILITY WILL MAINTAIN SCATTERED CONVECTIVE SHOWERS ALONG AND IN ADVANCE OF THE FRONT THROUGH 03Z. THEREAFTER...CLEARING IS RATHER SHARP BEHIND THE SHORTWAVE TROUGH...AND PRECIPITATION SHOULD GENERALLY END. MAY SEE A FEW LINGERING SNOW SHOWERS THRU 06-09Z ACROSS THE NRN MTNS WITH 1-2 ACCUMULATION ACROSS THE SUMMITS...BUT SKIES WILL GRADUALLY CLEAR IN VALLEY LOCATIONS. NW WINDS 5-10 MPH OVERNIGHT SHOULD PRECLUDE MUCH IN THE WAY OF FOG...BUT CAN/T COMPLETELY RULE OUT A BIT OF GROUND FOG IN THE SHELTERED VALLEYS DURING THE PRE- DAWN HOURS. STAYED SLIGHTLY ABOVE GUIDANCE FOR OVERNIGHT LOWS...MAINLY IN THE LOW 30S ACROSS THE CHAMPLAIN VALLEY AND UPR 20S ELSEWHERE. && .SHORT TERM /7 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 337 PM EDT FRIDAY...MUCH DRIER AIR MASS IN PLACE SATURDAY WITH SURFACE RIDGE AXIS MOVING IN AND CRESTING OVER THE NORTH COUNTRY LATE SATURDAY AFTN/EVE. LOOKING AT MOSTLY CLEAR SKIES AND LIGHT NWLY WINDS. HAVE RAISED HIGH TEMPS 5 DEG FROM MAV/MET BLEND BASED ON RECENT TRENDS...YIELDING A HIGH AROUND 50F IN BURLINGTON. OVERALL...A PLEASANT SATURDAY EXPECTED. CLEAR SKIES PERSIST MOST OF SATURDAY NIGHT WITH GOOD RADIATIONAL COOLING. LIGHT AND VARIABLE WINDS BECOME LIGHT S-SW ACROSS ST. LAWRENCE COUNTY AND INTO THE CHAMPLAIN VALLEY LATE AS RIDGE AXIS SLIDES TO THE MAINE COAST. LOWS AROUND 30F IN THE CHAMPLAIN/ST. LAWRENCE VALLEYS...BUT WILL LOCALLY DROP TO AROUND 20F IN THE MORE SHELTERED LOCATIONS OF THE ADIRONDACKS AND NE KINGDOM OF VERMONT GIVEN GOOD RADIATIVE COOLING SETUP IN THOSE LOCATIONS. A BREEZY DAY AND MILD DAY IS EXPECTED SUNDAY AS P-GRADIENT INCREASES. GRADIENT FLOW INCREASES FROM THE SOUTH AS OCCLUDED FRONT REACHES WRN NY/WRN PA BY 18Z SUNDAY. LOOKING AT 15-25 MPH WITH GUSTS TO 30 MPH EXPECTED. INCREASING HIGH CLOUDS DURING THE MORNING...THEN INTRODUCED INCREASING CHANCES FOR RAIN FROM WEST TO EAST DURING THE AFTN AND EVENING HOURS CONSISTENT WITH MOST OF THE MODEL GUIDANCE (12Z ECMWF IS A BIT SLOWER). WENT A COULD DEGREES ABOVE MOS CONSENSUS FOR HIGH TEMPS (MAINLY IN THE MID 50S IN THE VALLEYS). OCCLUDED FRONT SWINGS THRU 00-06Z MONDAY AND HAVE A PERIOD OF 80-100 POPS WITH SYSTEM BRINGING 0.2-0.4" RAINFALL AMTS MOST SECTIONS. SHOULD SEE ENOUGH COOLING ACROSS THE NRN ADIRONDACKS FOR A SWITCH TO SNOW ACROSS THE HIGHER TERRAIN LATE SUNDAY NIGHT WITH LIGHT SNOW ACCUMULATION POSSIBLE. LOW TEMPS WILL GENERALLY BE IN THE 30S SUNDAY NIGHT. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 337 PM EDT FRIDAY...OCCLUDED FRONT FROM THE ABOVE MENTIONED SYSTEM SHIFTS EAST OFF THE ATLANTIC COAST MONDAY LEAVING THE CWA IN A SEMI-DRY SLOT MONDAY MORNING. PRECIPITATION WILL FILL BACK IN ACROSS THE REGION BY MID-DAY THOUGH AS SURFACE COLD FRONT MOVES IN ASSOCIATED WITH PARENT LOW MOVING THROUGH SOUTHERN ONTARIO/QUEBEC. BOUNDARY LAYER PROFILES CONTINUE TO SHOW MAIN PTYPE WILL BE RAIN THROUGH MONDAY...BUT TRANSITIONS TO SNOW SHOWERS AS THE FRONT PUSHES THROUGH MONDAY NIGHT. CHANCES FOR SNOW/RAIN SHOWERS CONTINUE TUESDAY AND WEDNESDAY AS WELL AS UPPER LOW IS SLOW TO SHIFT EAST ACROSS QUEBEC AND A SERIES OF SHORTWAVES ROTATE AROUND THE UPPER FLOW. WITH THE COLD CORE UPPER LOW OVER THE REGION AND STRONG COLD AIR ADVECTION AT THE SURFACE...HIGH TEMPS TUESDAY/WEDNESDAY WILL BE WELL BELOW NORMAL IN THE 30S. LOOKS LIKE A FAIRLY COLD NIGHT TOO FOR TUESDAY NIGHT WITH 925-850MB TEMPS IN THE TEENS BELOW ZERO SUPPORTING LOWS MAINLY IN THE TEENS AND DOWN INTO THE SINGLE NUMBERS IN THE COLDER HOLLOWS OF THE DACKS (IE KSLK). PRECIP CHANCES DECREASE GOING INTO WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS EAST FROM THE GREAT LAKES AND ANOTHER BELOW NORMAL NIGHT IS EXPECTED WITH LOWS IN THE TEENS TO LOWER 20S. UPPER RIDGE CRESTS OVER THE NORTH COUNTRY THURSDAY WITH A NICE SPRING DAY LIKELY WITH SUNNY SKIES AND TEMPS WARMING INTO THE 40S. RIDGE BREAKS DOWN THOUGH GOING INTO THURSDAY NIGHT AND FRIDAY TURNING INTO FAIRLY ZONAL FLOW. NO REAL SYSTEMS ON THE OUTLOOK THROUGH THIS PERIOD BUT WITH WESTERLY FLOW ALOFT WE`LL LIKELY SEE A MIX OF SUN AND CLOUDS AND TEMPS RUNNING NEAR NORMAL WITH HIGHS IN THE 40S AND LOWS IN THE 20S TO LOW 30S. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... THROUGH 00Z SUNDAY...ANY LINGERING LIGHT SHOWERS/SPRINKLES ENDING THIS EVENING AS BKN/OVC VFR CIGS TREND TOWARD SKC AFTER 04-08Z AS HIGH PRESSURE BUILDS INTO THE REGION. ONLY EXCEPTION AT KSLK TERMINAL WHERE SOME PESKY MVFR CIGS AROUND FL025 WILL PERSIST THROUGH 03-05Z. WINDS GENERALLY LIGHT WEST TO NORTHWESTERLY AT 5 KTS OR LESS. WE COULD ALSO SEE SOME PATCHY BR SFC VISIBILITIES LATER TONIGHT AS LOWER LEVELS NEAR SATURATION...BUT FEEL ENOUGH MIXING IN THE LOWER LEVELS TO PRECLUDE MENTION AT ANY DISCRETE TERMINAL AT THIS TIME. AFTER 14Z SATURDAY...CLEAR SKIES AND LIGHT WEST TO NORTHWESTERLY WINDS OF 5-10 KTS ARE EXPECTED AS AFOREMENTIONED HIGH PRESSURE BUILDS INTO THE REGION. OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY... 00Z SUNDAY THROUGH 18Z SUNDAY...VFR CONDITIONS UNDER HIGH PRESSURE. 18Z SUNDAY THROUGH 12Z WEDNESDAY...FRONTAL SYSTEM MOVING THROUGH SOUTHERN ONTARIO/QUEBEC WILL BRING LOWERING CEILINGS AND MVFR CONDITIONS IN SCATTERED RAIN/SNOW SHOWERS. 12Z WEDNESDAY THROUGH 00Z THURSDAY...MVFR TRENDING TO VFR AS HIGH PRESSURE BUILDS INTO THE REGION. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS/LOCONTO SHORT TERM...BANACOS LONG TERM...LAHIFF AVIATION...JMG/LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
651 PM EDT FRI MAR 29 2013 .SYNOPSIS... AN UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE COLD FRONT WILL SHIFT SOUTHEASTWARD ACROSS THE NORTH COUNTRY DURING THE LATE AFTERNOON AND EVENING HOURS...BRINGING SCATTERED RAIN SHOWERS AND HIGHER ELEVATION SNOW SHOWERS. PRECIPITATION WILL END DURING THE PRE-DAWN HOURS SATURDAY. SURFACE HIGH PRESSURE BUILDS INTO THE NORTH COUNTRY DURING SATURDAY BRINGING MOSTLY SUNNY SKIES AND VALLEY TEMPERATURES IN THE UPPER 40S TO LOWER 50S. CLOUDS WILL INCREASE DURING SUNDAY...WITH THE NEXT FRONTAL SYSTEM BRINGING RAIN LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. && .NEAR TERM /UNTIL 7 AM SATURDAY MORNING/... AS OF 651 PM EDT FRIDAY...RECENT COMPOSITE RADAR IMAGERY SHOWS AN OVERALL DECREASE IN COVERAGE OF INSTABILITY RAIN/MTN SNOW SHOWERS ACROSS THE NORTH COUNTRY LATE THIS AFTERNOON. WATER VAPOR IMAGERY AND RAP OBJECTIVE ANALYSES SUGGEST THE THE WEAK SHORTWAVE DISTURBANCE IN NORTHWEST FLOW ALOFT AND ITS ASSOCIATED COLD POCKET OF AIR IN LOW/MID-LEVELS IS CURRENTLY PUSHING INTO SOUTHERN NEW ENGLAND...WITH DRIER SUBSIDENT FLOW ENTERING INTO THE SAINT LAWRENCE VALLEY. COMBINATION OF LOSS OF DAYTIME HEATING AND THE CONTINUED SOUTHEASTWARD MOVEMENT OF THE SHORTWAVE TROUGH SHOULD CONTINUE TO RESULT IN A DECREASE IN RAIN/SNOW SHOWER COVERAGE AND SKY COVER OVER THE NEXT FEW HOURS. BY LATE EVENING...WOULD EXPECT THAT ANY SHOWER ACTIVITY WOULD HAVE ENDED. MAINLY DRY FORECAST WITH SKIES CONTINUING TO CLEAR OUT DURING THE OVERNIGHT. THERE COULD BE A FEW SHELTERED VALLEYS AND HOLLOWS THAT MAY SEE SOME GROUND FOG/MIST BUT WILL LEAVE OUT OF THE FORECAST FOR NOW DUE TO THE LIMITED EXTENT OF ANY MIST/FOG. NO CHANGES TO LOW TEMPERATURES FOR THIS EVENING...GENERALLY IN THE 20S TO LOWER 30S. PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 337 PM EDT FOLLOWS... MARGINALLY UNSTABLE AIR MASS IN PLACE LATE THIS AFTERNOON (RAP- BASED LAPS ANALYSIS SHOWS SBCAPE VALUES AROUND 100 J/KG AT 19Z) WITH TEMPS IN THE UPR 40S IN THE VALLEYS. WEAK UPR TROUGH AND ASSOCIATED SFC COLD FRONT ACROSS THE ST. LAWRENCE VALLEY WILL TRANSLATE STEADILY SEWD ACROSS THE NORTH COUNTRY THIS EVENING...AND ASSOCIATED WEAK SYNOPTIC ASCENT AND INSTABILITY WILL MAINTAIN SCATTERED CONVECTIVE SHOWERS ALONG AND IN ADVANCE OF THE FRONT THROUGH 03Z. THEREAFTER...CLEARING IS RATHER SHARP BEHIND THE SHORTWAVE TROUGH...AND PRECIPITATION SHOULD GENERALLY END. MAY SEE A FEW LINGERING SNOW SHOWERS THRU 06-09Z ACROSS THE NRN MTNS WITH 1-2 ACCUMULATION ACROSS THE SUMMITS...BUT SKIES WILL GRADUALLY CLEAR IN VALLEY LOCATIONS. NW WINDS 5-10 MPH OVERNIGHT SHOULD PRECLUDE MUCH IN THE WAY OF FOG...BUT CAN/T COMPLETELY RULE OUT A BIT OF GROUND FOG IN THE SHELTERED VALLEYS DURING THE PRE- DAWN HOURS. STAYED SLIGHTLY ABOVE GUIDANCE FOR OVERNIGHT LOWS...MAINLY IN THE LOW 30S ACROSS THE CHAMPLAIN VALLEY AND UPR 20S ELSEWHERE. && .SHORT TERM /7 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 337 PM EDT FRIDAY...MUCH DRIER AIR MASS IN PLACE SATURDAY WITH SURFACE RIDGE AXIS MOVING IN AND CRESTING OVER THE NORTH COUNTRY LATE SATURDAY AFTN/EVE. LOOKING AT MOSTLY CLEAR SKIES AND LIGHT NWLY WINDS. HAVE RAISED HIGH TEMPS 5 DEG FROM MAV/MET BLEND BASED ON RECENT TRENDS...YIELDING A HIGH AROUND 50F IN BURLINGTON. OVERALL...A PLEASANT SATURDAY EXPECTED. CLEAR SKIES PERSIST MOST OF SATURDAY NIGHT WITH GOOD RADIATIONAL COOLING. LIGHT AND VARIABLE WINDS BECOME LIGHT S-SW ACROSS ST. LAWRENCE COUNTY AND INTO THE CHAMPLAIN VALLEY LATE AS RIDGE AXIS SLIDES TO THE MAINE COAST. LOWS AROUND 30F IN THE CHAMPLAIN/ST. LAWRENCE VALLEYS...BUT WILL LOCALLY DROP TO AROUND 20F IN THE MORE SHELTERED LOCATIONS OF THE ADIRONDACKS AND NE KINGDOM OF VERMONT GIVEN GOOD RADIATIVE COOLING SETUP IN THOSE LOCATIONS. A BREEZY DAY AND MILD DAY IS EXPECTED SUNDAY AS P-GRADIENT INCREASES. GRADIENT FLOW INCREASES FROM THE SOUTH AS OCCLUDED FRONT REACHES WRN NY/WRN PA BY 18Z SUNDAY. LOOKING AT 15-25 MPH WITH GUSTS TO 30 MPH EXPECTED. INCREASING HIGH CLOUDS DURING THE MORNING...THEN INTRODUCED INCREASING CHANCES FOR RAIN FROM WEST TO EAST DURING THE AFTN AND EVENING HOURS CONSISTENT WITH MOST OF THE MODEL GUIDANCE (12Z ECMWF IS A BIT SLOWER). WENT A COULD DEGREES ABOVE MOS CONSENSUS FOR HIGH TEMPS (MAINLY IN THE MID 50S IN THE VALLEYS). OCCLUDED FRONT SWINGS THRU 00-06Z MONDAY AND HAVE A PERIOD OF 80-100 POPS WITH SYSTEM BRINGING 0.2-0.4" RAINFALL AMTS MOST SECTIONS. SHOULD SEE ENOUGH COOLING ACROSS THE NRN ADIRONDACKS FOR A SWITCH TO SNOW ACROSS THE HIGHER TERRAIN LATE SUNDAY NIGHT WITH LIGHT SNOW ACCUMULATION POSSIBLE. LOW TEMPS WILL GENERALLY BE IN THE 30S SUNDAY NIGHT. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 337 PM EDT FRIDAY...OCCLUDED FRONT FROM THE ABOVE MENTIONED SYSTEM SHIFTS EAST OFF THE ATLANTIC COAST MONDAY LEAVING THE CWA IN A SEMI-DRY SLOT MONDAY MORNING. PRECIPITATION WILL FILL BACK IN ACROSS THE REGION BY MID-DAY THOUGH AS SURFACE COLD FRONT MOVES IN ASSOCIATED WITH PARENT LOW MOVING THROUGH SOUTHERN ONTARIO/QUEBEC. BOUNDARY LAYER PROFILES CONTINUE TO SHOW MAIN PTYPE WILL BE RAIN THROUGH MONDAY...BUT TRANSITIONS TO SNOW SHOWERS AS THE FRONT PUSHES THROUGH MONDAY NIGHT. CHANCES FOR SNOW/RAIN SHOWERS CONTINUE TUESDAY AND WEDNESDAY AS WELL AS UPPER LOW IS SLOW TO SHIFT EAST ACROSS QUEBEC AND A SERIES OF SHORTWAVES ROTATE AROUND THE UPPER FLOW. WITH THE COLD CORE UPPER LOW OVER THE REGION AND STRONG COLD AIR ADVECTION AT THE SURFACE...HIGH TEMPS TUESDAY/WEDNESDAY WILL BE WELL BELOW NORMAL IN THE 30S. LOOKS LIKE A FAIRLY COLD NIGHT TOO FOR TUESDAY NIGHT WITH 925-850MB TEMPS IN THE TEENS BELOW ZERO SUPPORTING LOWS MAINLY IN THE TEENS AND DOWN INTO THE SINGLE NUMBERS IN THE COLDER HOLLOWS OF THE DACKS (IE KSLK). PRECIP CHANCES DECREASE GOING INTO WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS EAST FROM THE GREAT LAKES AND ANOTHER BELOW NORMAL NIGHT IS EXPECTED WITH LOWS IN THE TEENS TO LOWER 20S. UPPER RIDGE CRESTS OVER THE NORTH COUNTRY THURSDAY WITH A NICE SPRING DAY LIKELY WITH SUNNY SKIES AND TEMPS WARMING INTO THE 40S. RIDGE BREAKS DOWN THOUGH GOING INTO THURSDAY NIGHT AND FRIDAY TURNING INTO FAIRLY ZONAL FLOW. NO REAL SYSTEMS ON THE OUTLOOK THROUGH THIS PERIOD BUT WITH WESTERLY FLOW ALOFT WE`LL LIKELY SEE A MIX OF SUN AND CLOUDS AND TEMPS RUNNING NEAR NORMAL WITH HIGHS IN THE 40S AND LOWS IN THE 20S TO LOW 30S. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... THROUGH 12Z SATURDAY...GENERALLY VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS. WIDESPREAD BKN-OVC VFR DECK THIS AFTERNOON WITH A SOME ISOLATED SHOWERS OUT THERE ASSOCIATED WITH A WEAK DISTURBANCE PASSING THROUGH THE FLOW ALOFT. AS THIS EXITS THE REGION TO THE EAST LATER THIS EVENING AND HIGH PRESSURE BUILDS IN...SKIES WILL BEGIN TO CLEAR FROM WEST TO EAST AFTER 22Z AT KMSS...AND BY 02/03Z AT KMPV/KRUT. FOR THE REMAINDER OF THE OVERNIGHT HOURS...GOOD LIKELIHOOD OF SOME BR FORMING WITH CLEARING SKIES...ABATING WINDS AND LOTS OF SOIL MOISTURE ACROSS THE REGION. DON`T THINK WE`LL SEE ANYTHING LOWER THEN MVFR THOUGH AS BOUNDARY LAYER WINDS STAY AROUND 5-10KTS UP TO 1 KFT. AFTER 14Z...CLEAR SKIES AND LIGHT NW WINDS OF 5-10 KTS IS EXPECTED FOR SATURDAY. OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY... 18Z SATURDAY THROUGH 18Z SUNDAY...VFR CONDITIONS UNDER HIGH PRESSURE. 18Z SUNDAY THROUGH 12Z WEDNESDAY...FRONTAL SYSTEM MOVING THROUGH SOUTHERN ONTARIO/QUEBEC WILL BRING LOWERING CEILINGS AND MVFR CONDITIONS IN SCATTERED RAIN/SNOW SHOWERS. 12Z WEDNESDAY THROUGH 00Z THURSDAY...MVFR TRENDING TO VFR AS HIGH PRESSURE BUILDS INTO THE REGION. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...BANACOS NEAR TERM...BANACOS/LOCONTO SHORT TERM...BANACOS LONG TERM...LAHIFF AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
106 PM EDT FRI MAR 29 2013 .SYNOPSIS... SURFACE HIGH PRESSURE WILL CONTINUE TO MOVE SLOWLY EAST THROUGH SATURDAY. AN UPPER LEVEL DISTURBANCE MOVES THROUGH THE REGION OVERNIGHT THROUGH EARLY SATURDAY. A WARM FRONT LIFTS NORTH ACROSS PARTS OF THE CAROLINAS SUNDAY...WITH A WEAK COLD FRONT SWEEPING EAST OVER THE REGION SUNDAY AFTERNOON AND SUNDAY NIGHT. && .NEAR TERM /THROUGH SATURDAY/... AS OF 955 AM FRIDAY... THROUGH TONIGHT: THE LATEST SURFACE ANALYSIS SHOWED THE SURFACE RIDGE OF HIGH PRESSURE DIRECTLY OVER CENTRAL NORTH CAROLINA...AND THIS WILL GRADUALLY MOVE TO THE EAST DURING THE AFTERNOON AS MID-LEVEL SHORTWAVE APPROACHES THE AREA FROM THE WEST AND NORTHWEST. IR IMAGES SHOW A SMALL REGION OF COLD-TOPPED CLOUDS ASSOCIATED WITH PRECIPITATION OVER PARTS OF KENTUCKY AND TENNESSEE...THOUGH GUIDANCE SUGGESTS THESE CLOUDS SHOULD WARM AND PRECIPITATION WEAKEN AS DRY AIR IS ENCOUNTERED TO THE EAST. THE MORNING KGSO SOUNDING SHOWED A PRECIPITABLE WATER VALUE UNDER A QUARTER-INCH...AND CENTRAL NORTH CAROLINA WAS REGIONALLY THE MINIMUM IN SURFACE THETA-E...ALONG WITH BUFR SOUNDINGS FROM THE NAM AND THE GFS MAINTAINING A FAIRLY DRY AIR MASS THROUGH THE AFTERNOON. A LARGE PATCH OF COOL HIGH SC/LOW AC TOWARD KRZZ AND KETC SHOULD GRADUALLY SHIFT EAST-SOUTHEAST LATE THIS MORNING AND THIS AFTERNOON IN CONCERT WITH THE LOW-LEVEL MOISTURE FIELDS OF THE RUC AND NAM...SUCH THAT MOST OF CENTRAL NORTH CAROLINA WILL SEE CONSIDERABLE SUNSHINE FOR MUCH OF THE DAY. MID-LEVEL CLOUDS WILL INCREASE LATE...AND WHILE MOISTURE INCREASES IN THE ICE NUCLEATION ZONE BETWEEN -10C AND -15C VERY LATE TODAY AND ESPECIALLY THIS EVENING...THE DEPTH OF MOISTURE IS SHALLOW WITH DRY AIR REMAINING IN THE BOUNDARY LAYER. KEPT HIGH TEMPERATURES AS IS THOUGH THE IMMEDIATE TRIAD MAY BE ON THE HIGH END OF THE EXPECTED RANGE...BUT GOOD SUN FOR MUCH OF THE DAY AND WEST WINDS WITH A FEW GUSTS IN THE LOWER TEENS KTS SHOULD HELP WARM THE AIR MASS. THE LATEST BUFR SOUNDINGS FROM THE NAM AND THE GFS SUGGEST THAT THE SOUTHWEST PIEDMONT INTO THE SANDHILLS HAVE A CHANCE OF SPRINKLES OVERNIGHT. TOWARD KGSO...KRDU...AND KRWI...THE MOISTURE DEPTH REMAINS SHALLOW...HOWEVER...TOWARD KFAY...ON BOTH MODELS THE DEPTH OF MOISTURE IS GREATER WITH ALSO GREATER MOISTURE IN THE BOUNDARY LAYER. WITH QPF FORECAST BY BOTH MODELS AS WELL...FOR NOW HAVE INTRODUCED SPRINKLES AND MAY HAVE TO INCREASE POPS INTO THE CHANCE CATEGORY FOR PARTS OF THIS AREA IN SUBSEQUENT FORECASTS...WHICH COULD LINGER INTO PART OF SATURDAY MORNING. THE INCREASE IN CLOUD COVER SHOULD LEAD TO WARMER OVERNIGHT LOW TEMPERATURES THAN PREVIOUS NIGHTS...WITH LOWS GENERALLY IN THE UPPER 30S TO LOWER 40S. -DJF SATURDAY: SURFACE HIGH PRESSURE CENTERED TO THE NORTH OF THE AREA SATURDAY MORNING WILL QUICKLY SHIFT OFFSHORE ON SATURDAY AFTERNOON RESULTING IN A RENEWED SOUTHERLY/SOUTHWESTERLY RETURN FLOW AFTER A BRIEF PERIOD OF NORTHERLY SURFACE FLOW BEHIND THE AFOREMENTIONED SURFACE TROUGH. HOWEVER... GIVEN LINGERING LOW LEVEL MOISTURE BELOW THE SUBSIDENCE INVERSION AROUND 800 MB ALONG WITH INCREASING MID AND HIGH CLOUDS IN ADVANCE OF A SYSTEM APPROACHING THE AREA FROM THE WEST WILL HELP KEEP SKIES PARTLY SUNNY DURING THE AFTERNOON. AFTERNOON LOW LEVEL THICKNESS VALUES ARE EXPECTED TO BE AROUND 10 TO 15 METERS BELOW NORMAL AT LEAST. THUS... GIVEN THIS AND THE CLOUD COVER WILL CONTINUE TO TREND FORECAST HIGHS FOR SATURDAY A LITTLE BIT BELOW STATISTICAL GUIDANCE VALUES. THIS YIELDS HIGH TEMPS IN THE LOWER TO MID 60S ACROSS THE AREA. -BSD && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 305 AM FRIDAY... SATURDAY NIGHT INTO SUNDAY...INCREASING LOW LEVEL WAA COUPLED WITH MODEST MOISTURE TRANSPORT OFF THE NE GULF OF MEXICO AND ATLANTIC WILL AID IN THE DEVELOPMENT OF SPOTTY RAIN SHOWERS LATE SATURDAY NIGHT INTO SUNDAY MORNING...MAINLY ACROSS THE SOUTHERN AND WESTERN SECTIONS OF CENTRAL NC. INCREASING/THICKENING CLOUD COVERAGE AND A LIGHT SLY SFC WIND WILL RESULT IN MIN TEMPS SATURDAY NIGHT ABOUT 10 DEGREES WARMER THAN TONIGHT. LATER SUNDAY...A WEAK MID LEVEL TROUGH WILL CROSS THE REGION. THIS FEATURE INTERACTING WITH THE AVAILABLE MOISTURE AND WEAK INSTABILITY WILL TRIGGER ADDITIONAL SHOWER ACTIVITY. EXPECT SHOWER COVERAGE TO BE A LITTLE MORE IN THE NORTHERN PIEDMONT DUE TO CLOSE PROXIMITY OF A STALLED SURFACE BOUNDARY ACROSS SOUTHERN VA. SHOWER COVERAGE/INTENSITY SHOULD DIMINISH WEST-TO-EAST BY MID-LATE AFTERNOON AS THE MID LEVEL TROUGH EXITS THE REGION. RAIN TOTALS APPEAR MEAGER THOUGH DUE TO LACK OF STRONG CONVERGENCE IN THE LOW-MID LEVELS OF THE ATMOSPHERE. RAINFALL SHOULD TOTAL UNDER A QUARTER OF AN INCH WITH MOST LOCATIONS MEASURING LESS THAN A TENTH OF AN INCH. IN SPITE OF CONSIDERABLE CLOUDINESS AND SCATTERED SHOWERS...MAX TEMPS SUNDAY WILL BE JUST A FEW DEGREES SHY OF NORMAL...MAINLY IN THE MID-UPPER 60S. IF SHOWER COVERAGE IS MORE EXTENSIVE THAN CURRENT THINKING...THIS MAY HOLD DOWN TEMPS BY 4-6 DEGREES...ESPECIALLY ACROSS THE NW. SUNDAY NIGHT AND MONDAY...SUBSIDENCE IN WEAK OF DEPARTING MID LEVEL TROUGH ALONG WITH MEAN WLY FLOW WILL RESULT IN DECREASING CLOUD COVERAGE SUNDAY NIGHT INTO MONDAY. RESIDUAL SFC MOISTURE AND CLEARING SKIES ALOFT MAY ALLOW FOR THE DEVELOPMENT OF PATCHY FOG BY EARLY MONDAY. A LIGHT SW SFC FLOW ALONG WITH PATCHY CLOUD COVER SHOULD RESULT IN FAIRLY MILD OVERNIGHT TEMPS (COMPARED TO THE PAST TWO WEEKS). MIN TEMPS GENERALLY 50-55. A MIXTURE OF CLOUDS/SUN ON MONDAY PLUS A STEADY SW WIND OCCASIONALLY GUSTING BETWEEN 20-25 MPH WILL BOOST TEMPS TO NEAR OR SLIGHTLY ABOVE NORMAL (NEAR 70-LOWER 70S). AFTERNOON HEATING MAY TRIGGER A SHOWER OR TWO BUT MOST LOCATIONS WILL REMAIN DRY. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... AS OF 305 AM FRIDAY... MONDAY NIGHT THROUGH TUESDAY NIGHT...A MODERATE TO STRONG S/W IN THE NORTHERN BRANCH OF POLAR JET CROSSING THE GREAT LAKES WILL AID TO DRIVE THE STALLED SFC BOUNDARY ACROSS SOUTHERN VA THROUGH CENTRAL NC LATE MONDAY NIGHT INTO TUESDAY. GFS MUCH QUICKER WITH THIS FRONTAL MOVEMENT...ABOUT 6-8 HOURS FASTER COMPARED TO THE ECMWF. ECMWF HAS BACKING OF OTHER MODELS WHILE GFS APPEARS TO BE A SOUTHERN/EASTERN OUTLIER BY TUESDAY. THUS WILL FAVOR THE SLOWER FRONTAL ARRIVAL TIME. THIS REQUIRES SOME ADJUSTMENT TO MIN TEMPS MONDAY NIGHT. WILL RAISE MIN TEMPS ABOUT 5 DEGREES FROM PREVIOUS FORECAST (WITH THE POTENTIAL FOR MIN TEMPS TO BE AN ADDITIONAL 5-7 DEGREES WARMER). MIN TEMPS UPPER 40S TO LOWER 50S. COOL/MOIST NE FLOW BEHIND THE BOUNDARY WILL RESULT IN A DREARY DAY TUESDAY WITH PATCHES OF LIGHT RAIN PROBABLE IN THE HYBRID DAMMING SCENARIO. TEMPS WILL BE MUCH COOLER (ABOUT 20 DEGREES) COMPARED TO MONDAY WITH DAYTIME TEMPS 50-55. FOR MANY LOCATIONS...CALENDER DAY HIGH TEMPS WILL LIKELY OCCUR BETWEEN MIDNIGHT-8 AM. EXPECT IMPROVING CONDITIONS LATE TUESDAY INTO TUESDAY NIGHT AS SFC FRONT SLIDES FARTHER AWAY AND MID LEVEL TROUGH CROSSES THE REGION. MIN TEMPS TUESDAY NIGHT LOW-MID 30S. WEDNESDAY INTO THURSDAY WILL FEATURE DRY AND COOL CONDITIONS AS SURFACE HIGH OVER THE CENTRAL U.S. BUILDS INTO THE CAROLINAS AND BASE OF L/W TROUGH SETTLES OVERHEAD. THICKNESSES WEDNESDAY CLOSE TO 40M BELOW NORMAL WITH A MODEST RECOVERY ON THU. THIS SUGGEST AFTERNOON TEMPS WELL BELOW NORMAL FOR EARLY APRIL. MAX TEMPS 50-55 WEDNESDAY AND LOW-MID 50S THURSDAY. EXPECT MIN TEMPS EARLY THU IN THE 30-35 DEGREE RANGE. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 105 PM FRIDAY... VFR CONDITIONS ARE ANTICIPATED THROUGH THE 18Z VALID TAF PERIOD. MID-LEVEL CLOUDS WILL INCREASE OVER CENTRAL NORTH CAROLINA...AND AS AN UPPER-LEVEL DISTURBANCE MOVES INTO AND THROUGH THE REGION LATE TONIGHT AND EARLY SATURDAY...THERE SHOULD BE AREAS OF LIGHT RAIN MAINLY TOWARD KFAY. MODEL GUIDANCE SUGGESTS THAT CONDITIONS SHOULD REMAIN PREDOMINANTLY VFR IN THE LIGHT RAIN...ALTHOUGH THERE IS CERTAINLY A MODEST CHANCE OF MVFR CONDITIONS IN CLOUDS AND/OR VISIBILITY AT KFAY MAINLY BETWEEN 10Z AND 16Z SATURDAY. BEYOND THE 18Z VALID TAF PERIOD...CHANCES FOR ADVERSE AVIATION CONDITIONS INCLUDING IFR CONDITIONS INCREASE FOR LATE SATURDAY NIGHT AND SUNDAY MORNING. AHEAD OF A WARM FRONT...THERE IS SOME POTENTIAL FOR LOW-LEVEL WIND SHEAR AS WELL DURING THE SAME TIME FRAME...WITH VEERING OF THE WINDS ALOFT AND AN INCREASE IN SPEED THROUGH THE LOW LEVELS OF THE ATMOSPHERE. A FEW THUNDERSTORMS ARE ALSO POSSIBLE SUNDAY AHEAD OF A COLD FRONT. BEYOND SUNDAY...THERE IS ANOTHER CHANCE FOR IFR CONDITIONS OVERNIGHT MONDAY INTO EARLY TUESDAY AHEAD OF ANOTHER COLD FRONT THAT WILL PUSH THROUGH CENTRAL NORTH CAROLINA. CONDITIONS ARE MOST LIKELY VFR DURING THE DAY MONDAY...AND AGAIN FOR WEDNESDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF/BSD SHORT TERM...WSS LONG TERM...WSS AVIATION...DJF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
324 PM CDT FRI MAR 29 2013 .SHORT TERM... MAIN CHALLENGE FOR THIS FORECAST CONTINUES TO BE PERSISTENT FOG AND TEMPERATURES. SOUNDINGS CONTINUE TO SHOW STRONG INVERSION NEAR THE SURFACE WITH LIGHT WINDS...THUS EXPECT AREAS OF FOG TO CONTINUE IN THE DVL BASIN AND ALONG THE RED RIVER VALLEY. HOWEVER...WILL LET THE ADVISORY EXPIRE AT 21Z AS MOST AREAS HAVE IMPROVED. FOR THIS EVENING INTO TONIGHT...A WAVE ASSOCIATED WITH AN AREA OF LOW PRESSURE IS EXPECTED TO MOVE ACROSS THE AREA TONIGHT. ANALYSIS OF THE 295K ISENTROPIC SFC SHOWS DECENT UPGLIDE AND FAVORABLE CONDENSATION PRESSURE DEFICITS POINTING TOWARD PCPN OVERNIGHT. FCST SOUNDINGS SHOW A WARM LAYER ALOFT AND IS SUFFICIENTLY DEEP TO FAVOR -ZR ACROSS THE SRN ZONES AND IS REFLECTED IN THE GRIDS. FOR SATURDAY...GFS AND ECMWF SHOW GOOD COLD ADVECTION BEHIND THE FRONT WITH BREEZY CONDITIONS AND EXPECT THE COLD AIR WILL OFFSET ANY SOLAR. WITH A SIGNIFICANT SNOWPACK OVER THE FA...WILL KEEP TEMPS A BIT COOLER WITH LITTLE RECOVERY DURING THE DAY. OTHERWISE...EXPECT LOWS SUNDAY MORNING TO BE NEAR SINGLE DIGITS ACROSS THE NORTH. THE SFC RIDGE LOOKS TO CROSS THE AREA RAPIDLY AND RETURN FLOW ON MONDAY WILL HELP TEMPS RECOVER A BIT BUT REMAIN BELOW SEASONAL AVERAGES. LITTLE PCPN IS EXPECTED FOR THE REMAINDER OF THE WEEKEND. .LONG TERM (TUE THRU FRI)... THROUGH MUCH OF THE EXTENDED PERIOD THE VARIOUS MODELS ARE IN DECENT AGREEMENT THROUGH MOST OF THIS PERIOD. LIKE THE GFS BLENDED WITH BC-ECMWF. MODELS DIVERGE ON SOLUTIONS TOWARD THE END OF THE PERIOD AND BEYOND. AT THE START OF THE EXTENDED A SHARP TROUGH OVER THE GREAT LAKES WITH RESULTING NORTHWEST FLOW OVER CWFA. ECMWF/GEM/GFS/DGEX ALL IN GOOD AGREEMENT WITH SURFACE HIGH NORTH TO SOUTH THROUGH FA. LIGHT WINDS AND DECREASING CLOUD COVER FORECAST SO HAVE OPTED TO LOWER MINS TUESDAY MORNING ABOUT 5F...CLOSER TO BC-GRIDS WHICH HAVE BEEN PERFORMING BETTER. RETURN FLOW BEGINS BY 00Z WEDNESDAY BUT GUIDANCE SUGGESTS LOW LEVEL WAA SLOW TO CRANK UP. THEREFORE HAVE LOWERED MAXES ABOUT 2F TO 4F... AGAIN LEANING ON A BC-BLEND. LOW LEVEL WAA DOES KICK IN PRETTY STRONGLY BY 12Z WEDNESDAY. WHEN COMBINED WITH APPROACHING SHORTWAVE ...LOW LEVEL LIFT...850-500MB OMEGA AND LOWER COND PRES DEF LIKE THE IDEA OF SLGHT CHC/CHC POPS. LIKELY A MIX OF RA/SN...PERHAPS ALL RA AFTERNOON...BUT LIGHT AMOUNTS FORECAST. MODEST BOUNDARY LAYER TEMPERATURE DROP OF 4C TO 6C FORECAST BETWEEN WEDNESDAY AND THURSDAY...SO HAVE LOWERED THURSDAY MAXES ACCORDINGLY. I HAVE ALSO UPPED WIND SPEEDS A TAD AS THE LOW LEVEL CAA APPEARS FAIRLY IMPRESSIVE ON ALL MODELS. THIS FORECAST PERIOD ENDS WITH MODEL DIFFERENCES BECOMING MORE GLARING. WITH RETURN FLOW...INCREASING CLOUDS AND MOISTURE AS STRONG LOW LEVEL BOUNDARY SET THE STAGE FOR LIGHT -RA/-SN. ECMWF HAS A MORE PROGRESSIVE AND FARTHER NORTH SYSTEM WHILE GFS MUCH SLOWER AND FARTHER SOUTH. FOLLOWED GUIDANCE TO PAINT SWATH OF PRECIPITATION MOVING WEST TO EAST LATE THURSDAY INTO FRIDAY. MADE A RASN MIX DURING THE OVERNIGHT THURSDAY INTO EARLY FRIDAY. && .AVIATION... CONDITIONS ARE ALL OVER THE PLACE AS FOG DISSIPATES IN USUAL CHAOTIC MANNER. WELL DEFINED TONGUE OF IFR CIG/VSBY WITHIN THE RRV FLOOR SHRINKING FROM OUTSIDE INWARD. BIG QUESTION IS WILL LIFR FOG AND CIGS REDEVELOP AFTER SUNSET. GFS AND LAMP-MOS RE-EXPAND THE LOW CLOUDS AFTER 02Z. WILL FOLLOW THE LAMP/GFS MOS AS IT HAS HAD AN OKAY HANDLE ON THE CONDITIONS. HRRR HAS BEEN TOO EXPANSIVE AND GENERALLY IGNORED. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR NDZ006>008- 014>016-024-026>030-038-039-049-052>054. MN...DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ001>004- 007-029. && $$ HOPKINS/EWENS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
109 PM CDT FRI MAR 29 2013 .UPDATE... ISSUED AT 109 PM CDT FRI MAR 29 2013 TRIMMED THE WESTERN FRINGE OF THE DENSE FOG ADVISORY AS VISIBILITIES HAVE RECENTLY IMPROVED. JAMESTOWN IS STILL REPORTING ONE QUARTER MILE VISIBILITIES WITH SLOW IMPROVEMENT EXPECTED THROUGH THE AFTERNOON. AS A RESULT...EXTENDED THE DENSE FOG ADVISORY FOR THE EXTREME EASTERN CWA UNTIL 4 PM CDT. WILL CONTINUE TO MONITOR AFTERNOON OBS/TRENDS. FURTHERMORE...ADDED A SLIGHT CHANCE OF THUNDER SOUTHWEST AS THE LATEST SHORT RANGE MODELS PROG CAPE APPROACHING 200 J/KG AND SHOWALTER INDICES APPROACHING ZERO THIS AFTERNOON. NOT MUCH IF ANY PRECIP ASSOCIATED WITH A SHORTWAVE MOVING ACROSS THE REGION HAS BEEN REACHING THE GROUND. FURTHERMORE...SURFACE TEMPS NEAR TIOGA AND STANLEY ARE RIGHT AT 32 DEGREES. THEREFORE...THINK THE FREEZING RAIN THREAT IS DIMINISHING ACROSS NORTHWESTERN NORTH DAKOTA. HOWEVER...WILL CONTINUE TO HIGHLIGHT THIS ACTIVITY WITH SPECIAL WEATHER STATEMENTS. UPDATE ISSUED AT 1041 AM CDT FRI MAR 29 2013 FOG CONTINUES TO DISSIPATE ACROSS WESTERN AND PORTIONS OF CENTRAL NORTH DAKOTA THIS MORNING. AS A RESULT...CANCELLED THE DENSE FOG ADVISORY FOR AREAS ALONG AND WEST OF HIGHWAY 83. THE KGGW WSR-88D DETECTED AN AREA OF LIGHT PRECIPITATION MOVING EAST ACROSS NORTHEASTERN MONTANA THIS MORNING. THIS ACTIVITY IS EXPECTED TO ENTER NORTHWESTERN NORTH DAKOTA LATER THIS MORNING. HOWEVER...BY THE TIME IT REACHES SAID PORTION OF THE STATE...SURFACE TEMPS MAY BE NEAR OR ABOVE FREEZING. AS A RESULT...WILL HOLD OFF ON A FREEZING RAIN ADVISORY FOR NOW. WILL LIKELY HANDLE THE SITUATION WITH SPECIAL WEATHER STATEMENTS BASED ON SPOTTER REPORTS. THE UPDATED GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT. UPDATE ISSUED AT 645 AM CDT FRI MAR 29 2013 NO MAJOR CHANGES FROM THE CURRENT FORECAST. DENSE FOG REMAINS ALONG THE MISSOURI RIVER COUNTIES AND ALL POINTS NORTH AND EAST. DID GET A REPORT OF BREAKS IN THE FOG IN MCLEAN COUNTY...BUT OVERALL SFC OBS ARE COMING IN AT 1/4SM OR ZERO. FREEZING RAIN HAS BEEN REPORTED IN GLASGOW MONTANA...AND WILL NEED TO MONITOR IN CASE A FREEZING RAIN ADVISORY BECOMES NEEDED THIS MORNING. RIGHT NOW IT IS UNCERTAIN WHERE THE BEST ACCUMULATING PRECIPITATION WILL FALL OVER MY WEST. THE RAP TAKES IT SOUTH OF THE MISSOURI RIVER WHILE THE EC AND GEM ARE FARTHER NORTH NEAR KISN...AND THE NAM BRINGS THE HIGHER QPF OVER MY FAR NORTHWEST ALONG THE CANADIAN BORDER. && .SHORT TERM...TODAY AND TONIGHT... ISSUED AT 330 AM CDT FRI MAR 29 2013 THE CHALLENGES OF THE SHORT TERM ARE HOW LONG THE ONGOING DENSE FOG WILL PERSIST...THE IMPACT OF THE FOG ON TEMPERATURES FOR TODAY AND THE POTENTIAL FOR ISOLATED THUNDERSTORMS ACROSS THE SOUTHWEST THIS AFTERNOON WITH A WINTRY MIX NORTH. THE RAP AND HRRR HAVE HAD A GOOD HANDLE ON THE EVOLUTION OF THE DENSE FOG ACROSS CENTRAL AND NORTHWEST NORTH DAKOTA THROUGH THE NIGHT...AND WILL FOLLOW THEIR VISIBILITY FORECASTS FROM THEIR LATEST RUN (29/04 UTC). THIS WOULD SUGGEST THAT DENSE FOG...ESPECIALLY OVER THE SNOWPACK MAY HOLD NEAR ONE QUARTER OF A MILE THROUGH 18 UTC. THIS IS SUPPORTED BY THE OBSERVED FOG TRENDS SEEN ON THURSDAY IN A SIMILAR ENVIRONMENT. THUS HAVE EXPANDED THE DENSE FOG ADVISORY THROUGH 18 UTC. WOULD NOT RULE OUT A POSSIBLE EXPANSION IN TIME FOR PORTIONS OF THE ADVISORY LATER INTO THE AFTERNOON AS MID LEVEL CLOUD COVER MAY SLOW DOWN THE BURNING OFF OF THE FOG. IN REGARDS TO TEMPERATURES...WILL USE THE OBSERVED TEMPERATURE PATTERN ON THURSDAY AS A GUIDE...AND WILL LIMIT HIGHS TO THE UPPER 20S ACROSS MUCH OF THE SNOWPACK IMPACTED BY FOG. LIKE THURSDAY...THE SNOW AND FOG FREE SOUTHWEST IS EXPECTED TO WARM INTO THE UPPER 50S TO THE LOWER 60S AS MIXING INCREASES BEHIND A WEAK TROUGH. STEEP LAPSE RATES THROUGH MUCH OF THE TROPOSPHERE SUGGESTS DIURNALLY DRIVEN SHOWER ACTIVITY IS POSSIBLE...WITH ISOLATED THUNDERSTORMS NOT OUT OF THE QUESTION GIVEN THE COOL TEMPERATURES ALOFT AND STEEP LAPSE RATES SUPPORTING AFTERNOON ML CAPE VALUES OF 200-400 J/KG. ELSEWHERE IN REGARDS TO PRECIPITATION TODAY...A WEAK WAVE ACROSS SOUTHWEST SASKATCHEWAN AS OF 08 UTC WILL PROPAGATE SOUTHEAST THROUGH THE DAY. GIVEN THE WEAK FORCING AND DRY LOW LEVELS...PRECIPITATION WITH SCATTERED ACTIVITY WILL BE LIGHT. HOWEVER...WITH A WARM LAYER ALOFT ABOVE THE SUB-FREEZING SURFACE TEMPERATURES OF THE SNOWPACK...FREEZING RAIN AND SLEET ARE POSSIBLE. FOR TONIGHT...BOUNDARY LAYER MIXING ON THE ORDER OF 10 KTS CWA WIDE IN THE WAKE OF THE AFOREMENTIONED SURFACE TROUGH SHOULD HELP TO KEEP TEMPERATURES FROM BOTTOMING OUT TOO FAR...WITH SOME STRATUS ALSO HINTED IN THE 00 UTC DETERMINISTIC GUIDANCE. THUS...FOLLOWED FAIRLY CLOSELY TO A BLEND OF THE 00 UTC DETERMINISTIC MODEL SUITE FOR LOWS TONIGHT. .LONG TERM...SATURDAY THROUGH NEXT FRIDAY... ISSUED AT 330 AM CDT FRI MAR 29 2013 WILL SEE AN ACTIVE FLOW PATTERN THROUGH THE EASTER HOLIDAY WEEKEND AS A CLOSED UPPER LOW MOVES SOUTH ACROSS CENTRAL CANADA ON SATURDAY AND INTO THE GREAT LAKES REGION SUNDAY AND MONDAY. CYCLONIC FLOW ALOFT WILL BRING SEVERAL EMBEDDED S/WVS ACROSS THE NORTHERN PLAINS SATURDAY THROUGH SUNDAY AFTERNOON SO WILL MAINTAIN PRECIP CHANCES. ONLY LIGHT QPF IS DEPICTED. THE UPPER LOW WILL ALSO BRING A SURGE OF COLDER AIR INTO THE NORTHERN PLAINS SUNDAY INTO MONDAY. TEMPERATURES MODERATE BACK TO NORMAL BY MID-WEEK AS THE COLDER AIR MOVES OFF TO OUR EAST. WILL MAINTAIN A DRY FORECAST SUNDAY NIGHT THROUGH TUESDAY NIGHT WITH UPPER LEVEL RIDGING BUILDING ALOFT. FOR MID-WEEK...MODELS DISAGREEING ON A POTENTIAL CLIPPER IMPACTING THE REGION. OPTED TO KEEP THE FORECAST DRY. NEXT CHANCE OF PRECIPITATION ARRIVES AT THE END OF THE WORK WEEK WHEN THE UPPER JET PUSHES SOUTH TO ACROSS FAR SOUTHERN CANADA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 109 PM CDT FRI MAR 29 2013 VLIFR CONDITIONS IN FOG WILL CONTINUE AT KJMS THROUGH MID- AFTERNOON. OTHERWISE...ELEVATED SHOWER ACTIVITY WILL CONTINUE TO PUSH ACROSS THE STATE GENERATING VIRGA FROM MID-LEVEL CLOUDS. MOISTURE TRAPPED BENEATH HIGH PRESSURE BUILDING INTO THE REGION TONIGHT MAY GENERATE MVFR CIGS...MAINLY AFTER 06Z SATURDAY. A MIX OF MVFR/VFR CIGS ARE EXPECTED AREAWIDE SATURDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR NDZ005-013- 023-025-037-048-051. && $$ UPDATE...TM SHORT TERM...AYD LONG TERM...NH AVIATION...TM
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1240 PM CDT FRI MAR 29 2013 .AVIATION... A PERIOD OF UNSETTLED WEATHER IS EXPECTED THE NEXT 24-30 HOURS FOR ALL NORTH TEXAS TAF SITES. AN UPPER LEVEL DISTURBANCE WILL BE MOVING ACROSS THE REGION TONIGHT AND WILL PRODUCE SCATTERED TO CLUSTERS OF CONVECTION THAT BEGIN TO THE WEST AND TRACK EAST ACROSS THE METROPLEX TONIGHT /04-09 UTC /. HAVE ADDED A TEMPO GROUP FOR TSRA/BKN018CB 05-08 UTC. THERE IS ALSO THE POTENTIAL FOR A FEW STORMS TO BE MARGINALLY SEVERE OR SEVERE. IF THIS PANS OUT...THEN THE SEVERE WEATHER THREAT WILL BE MAINLY LARGE HAIL /ONE INCH TO TWO INCHES/ AND A LESSER THREAT OF DAMAGING WINDS. KACT SHOULD ESCAPE THIS EVENT BUT SHOULD SEE VCSH OVERNIGHT. CIGS ARE LIFTING AND EXPECT VFR SKIES THE REST OF THE AFTERNOON. MVFR CIGS WILL RETURN TONIGHT AFTER 03 UTC AND LAST THROUGH MID SUNDAY MORNING BEFORE IMPROVING. ALL SITES HAVE THE POTENTIAL TO SEE BRIEF IFR CONDITIONS 11-14 UTC SUNDAY AFTER THE CONVECTION MOVES EAST OF THE TAF SITES...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THIS CYCLE. WINDS WILL REMAIN SOUTHERLY 13-18KTS TODAY AND SUNDAY...AND 10-15KTS TONIGHT. 75 && .UPDATE... CURRENT FORECAST THROUGH THIS AFTERNOON IS IN GOOD SHAPE AND WILL ONLY MAKE SOME MINOR ADJUSTMENTS TO THE HOURLY GRIDDED DATA. SURFACE ANALYSIS INDICATES A WEAK LOW PRESSURE CENTER ACROSS THE TEXAS PANHANDLE THIS MORNING WITH A STATIONARY FRONTAL BOUNDARY EXTENDING EASTWARD ACROSS CENTRAL OKLAHOMA. STRONG LOW LEVEL WARM ADVECTION HAS AIDED IN A CLUSTER OF SHOWERS AND ELEVATED THUNDERSTORMS ACROSS CENTRAL OKLAHOMA. THESE SHOULD PRIMARILY CONTINUE TO MOVE EAST/SOUTHEAST THROUGH THE DAY WITH A GENERAL WEAKENING TREND AS LOW LEVEL FLOW BACKS AND WEAKENS OVER THE NEXT SEVERAL HOURS. FARTHER SOUTH...SOME SHOWERS ARE APPROACHING THE NORTHWEST COUNTIES. THIS ACTIVITY SHOULD REMAIN IN THE FORM OF SHOWERS AS A STRONG CAPPING INVERSION IS PRESENT ACROSS NORTH TEXAS AT THE PRESENT TIME. FOCUS QUICKLY TURNS TO AN APPROACHING MID LEVEL DISTURBANCE CURRENTLY ENTERING NEW MEXICO. THIS FEATURE INITIALLY WAS NOT SAMPLED WELL BY THE GUIDANCE AS IT WAS OFF THE COAST OF BAJA CALIFORNIA. IT SHOWED UP BETTER IN THE 12Z UPPER AIR ANALYSIS AS A MID LEVEL COLD POCKET OVER TUCSON ARIZONA THIS MORNING AND NOW APPEARS TO BE APPROACHING FAR WEST TEXAS. 12Z GUIDANCE APPEARS TO GENERATE SIGNIFICANTLY MORE FORCING FOR ASCENT WITH THIS FEATURE THIS AFTERNOON DURING PEAK HEATING. BY 00Z A DRYLINE SHOULD BE LOCATED ACROSS THE PANHANDLE AS THE STRONGEST FORCING OVERSPREADS IT. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY LATE AFTERNOON/EARLY EVENING IN AN AREA OF MODERATE INSTABILITY WITH VERY STEEP MID LEVEL LAPSE RATES. THIS SCENARIO WOULD SUPPORT A LARGE HAIL AND DAMAGING WIND THREAT MAINLY ACROSS NORTHWEST TEXAS. IT NOW APPEARS THAT AS THIS FORCING SPREADS EAST...CAPPING ACROSS NORTH TEXAS WILL RAPIDLY WEAKEN AND A CLUSTER OF THUNDERSTORMS WILL SPREAD EAST. THE COVERAGE AND INTENSITY DOES REMAIN SOMEWHAT IN QUESTION FARTHER EAST THOUGH DESPITE AN ERODING CAP. STORMS MAY TEND TO BECOME ELEVATED AS THE BOUNDARY LAYER COOLS AFTER SUNSET. WILL BE ASSESSING SOME HIGH RES GUIDANCE THROUGH EARLY AFTERNOON AND WILL LIKELY UP POPS DURING THE OVERNIGHT TIME FRAME ACROSS NORTH TEXAS. DUNN && .PREV DISCUSSION... /ISSUED 350 AM CDT FRI MAR 29 2013/ LATEST UPPER AIR ANALYSIS SHOWS TROUGHS OF LOW PRESSURE ACROSS THE NORTHEASTERN CONUS AND NORTHWESTERN CANADA. A SHORTWAVE CAN BE SEEN MOVING ONSHORE BAJA CALIFORNIA AND THIS DISTURBANCE WILL BE THE MAIN FOCUS FOR THE NEXT 24 HOURS. ON THE SURFACE...A LOW CENTER REMAINS POSITIONED NEAR THE TEXAS PANHANDLE WITH A TROUGH EXTENDING TO THE EAST INTO OKLAHOMA. THE 00Z FWD RAOB INDICATED A STOUT CAP IN PLACE AS WEST WINDS BETWEEN 700 AND 800 MB ARE LEADING TO WARM AIR ADVECTION. THIS CAP WILL KEEP NORTH TEXAS RAIN FREE FOR MOST OF THE DAY TODAY. THE FORECAST THEN BECOMES PROBLEMATIC AS THE SHORTWAVE NEARS THE REGION THIS EVENING. THE MODELS DIFFER ON THE HANDLING OF THIS SYSTEM AND THE WEAKENING OF THE CAP BY LATE AFTERNOON. THE GFS KEEPS THE CAP IN PLACE AND MOST OF THE AREA RAIN FREE...WHILE THE NAM/WRF/CANADIAN/ECMWF ALL WEAKEN THE CAP TO SOME DEGREE. THE NAM IS THE MOST AGGRESSIVE WITH THE REMOVAL OF THE CAP COMPLETELY BY 00Z. CURRENTLY ON WATER VAPOR THE SHORTWAVE LOOKS STRONGER THAN WHAT MOST MODELS HAVE INITIALIZED. THE DISTURBANCE IS STRONG ENOUGH THAT IT CAN BE SEEN ON CONSTANT PV SURFACES AS THE TROPOPAUSE DESCENDS IN THE ATMOSPHERE WITHIN THE CENTER OF THE TROUGH OF LOW PRESSURE. THE 00-HR RAP IS CURRENTLY INITIALIZING THIS TO OCCUR AT 330 MB...WHILE THE GFS AND NAM ARE AT 280 MB AND 295 MB RESPECTIVELY. WITH THE STRONGER TROUGH...WILL HOLD MORE WEIGHT WITH THE NAMS FORECAST OF ERODING THE CAP THIS AFTERNOON. HIGH-RES MODELS ARE INITIALIZING THUNDERSTORM DEVELOPMENT WEST/NORTHWEST OF THE FORECAST AREA...NEAR THE SURFACE LOW BEFORE 00Z THIS EVENING. PREVIOUS THINKING WAS THE CAP WOULD HOLD AND THESE STORMS WOULD WEAKEN AS THEY PROGRESSED EAST...RUNNING INTO THE CAP. IF THE CAP DOES ERODE...THERE SHOULD BE A DECENT COVERAGE OF STORMS INTO THE NORTHWEST ZONES AFTER 00Z. WITH CAPE VALUES NEAR 1500 J/KG AND MODERATE SHEAR VALUES A STRONG TO MARGINALLY SEVERE STORM IS POSSIBLE. OVERNIGHT...A COMPLEX OF STORMS IS EXPECTED TO DEVELOP NEAR THE SURFACE TROUGH IN OKLAHOMA AND THIS ACTIVITY COULD CLIP OUR NORTHEASTERN ZONES NEAR SUNRISE SATURDAY. AFTER THIS SYSTEM MOVES OUT ON SATURDAY...THINK THE REMAINDER OF THE DAY SHOULD BE RELATIVELY QUIET AS NO LARGE SCALE FORCING FOR ASCENT IS IN PLACE. SATURDAY NIGHT...THE TROUGH THAT IS CURRENTLY IN NORTHWESTERN CANADA WILL CONTINUE TO SLIDE SOUTHEAST AND SEND A COLD FRONT INTO SOUTHERN OKLAHOMA. THIS FRONT COMBINING WITH ANOTHER WEAK EMBEDDED SHORTWAVE WILL BRING MORE THUNDERSTORM CHANCES TO MAINLY THE NORTHERN ZONES. THIS FRONTAL BOUNDARY IS EXPECTED TO STALL NEAR THE I-20 CORRIDOR SUNDAY AFTERNOON AS THE UPPER LOW SHIFTS EAST. WITH THE SURFACE FOCUS IN PLACE FOR THE CWA...ADDITIONAL THUNDERSTORMS ARE POSSIBLE FOR THE AREA. CAPE VALUES MAY EXCEED 2000 J/KG AS LOWER 60 DEWPOINTS WILL BE IN PLACE. SHEAR IS EXPECTED TO BE WEAKER AND THIS WILL LIMIT THE OVERALL SEVERE POTENTIAL...BUT CANT RULE OUT A STRONG OR MARGINALLY SEVERE STORM SUNDAY AFTERNOON. ANOTHER SOUTHWARD MOVING IMPULSE OF UPPER ENERGY OUT OF CANADA WILL SEND A STRONGER FRONT SOUTH ON MONDAY. THIS FRONT IS EXPECTED TO MOVE THROUGH THE CWA MONDAY EVENING AND WILL CARRY ADDITIONAL THUNDERSTORM CHANCES WITH THE FROPA. MEDIUM RANGE GUIDANCE HAS HAD POOR RUN-TO-RUN CONSISTENCY WITH THE HANDLING OF FEATURES BEYOND MONDAY. THE 00Z GFS AND ECMWF ARE SIMILAR AND KEEP STRONG UPGLIDE ON TOP OF THE FRONTAL INVERSION THROUGH TUESDAY NIGHT AND WILL KEEP SLIGHT TO CHANCE POPS FOR LIGHT RAIN IN THE FORECAST. AFTER A VERY ACTIVE PERIOD...THE FINAL CHANCE OF RAIN WILL COME WHEN THE UPPER TROUGH CURRENTLY OVER THE PACIFIC OCEAN WILL SWING THROUGH THE AREA WEDNESDAY/WEDNESDAY NIGHT. MODELS LAST NIGHT SHOWED THIS LOW WEAKENING BEFORE IT MOVED THROUGH...BUT TONIGHT KEEP IT AS A STRONGER CLOSED LOW. THE TRACK OF THE LOW IS DIFFERENT BETWEEN THE GFS AND ECMWF...BUT BOTH SHOW LARGE SCALE FORCING FOR ASCENT AND WILL FORECAST 30 POPS FOR WEDNESDAY AND WEDNESDAY NIGHT. AGAIN...MODELS HAVE HAD A HARD TIME WITH THE FORECAST BEYOND MONDAY AND CONFIDENCE IS NOT HIGH. NEVERTHELESS...AN UNSETTLED WEATHER PATTERN IS EXPECTED BETWEEN TODAY AND NEXT WEDNESDAY WITH RAIN CHANCES IN THE FORECAST EACH DAY FOR MOST OF THE AREA. IT WONT RAIN EVERYDAY FOR ALL LOCATIONS...BUT CHANCES ARE THERE EACH DAY. TEMPERATURES THROUGH MONDAY WILL BE IN THE 70S/80S FOR HIGHS WITH LOWS IN THE 50S/60S. AFTER MONDAY...TEMPERATURES WILL BE DRASTICALLY COLDER BEHIND THE FRONT. HIGHS BEHIND THE FRONT TUESDAY AND WEDNESDAY WILL BE IN THE 40S/50S FOR HIGHS WITH LITTLE DIURNAL RANGE GIVEN THE CLOUD COVER AND RAIN CHANCES. SOUTH WINDS WILL RETURN BY THE END OF THE WEEK AND MODERATING TEMPERATURES CAN BE EXPECTED. HAMPSHIRE && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 77 62 80 62 76 / 10 30 20 40 40 WACO, TX 77 61 79 64 79 / 5 20 20 20 40 PARIS, TX 73 58 75 60 74 / 20 50 30 50 40 DENTON, TX 75 61 80 58 75 / 10 30 20 40 40 MCKINNEY, TX 75 61 80 60 76 / 10 30 20 40 40 DALLAS, TX 77 62 81 63 76 / 10 30 20 40 40 TERRELL, TX 76 62 79 63 75 / 10 30 20 30 40 CORSICANA, TX 76 60 77 62 78 / 10 20 20 20 40 TEMPLE, TX 76 61 78 62 81 / 5 10 20 20 30 MINERAL WELLS, TX 77 57 83 59 78 / 10 40 20 30 40 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 75/
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1118 AM CDT FRI MAR 29 2013 .UPDATE... CURRENT FORECAST THROUGH THIS AFTERNOON IS IN GOOD SHAPE AND WILL ONLY MAKE SOME MINOR ADJUSTMENTS TO THE HOURLY GRIDDED DATA. SURFACE ANALYSIS INDICATES A WEAK LOW PRESSURE CENTER ACROSS THE TEXAS PANHANDLE THIS MORNING WITH A STATIONARY FRONTAL BOUNDARY EXTENDING EASTWARD ACROSS CENTRAL OKLAHOMA. STRONG LOW LEVEL WARM ADVECTION HAS AIDED IN A CLUSTER OF SHOWERS AND ELEVATED THUNDERSTORMS ACROSS CENTRAL OKLAHOMA. THESE SHOULD PRIMARILY CONTINUE TO MOVE EAST/SOUTHEAST THROUGH THE DAY WITH A GENERAL WEAKENING TREND AS LOW LEVEL FLOW BACKS AND WEAKENS OVER THE NEXT SEVERAL HOURS. FARTHER SOUTH...SOME SHOWERS ARE APPROACHING THE NORTHWEST COUNTIES. THIS ACTIVITY SHOULD REMAIN IN THE FORM OF SHOWERS AS A STRONG CAPPING INVERSION IS PRESENT ACROSS NORTH TEXAS AT THE PRESENT TIME. FOCUS QUICKLY TURNS TO AN APPROACHING MID LEVEL DISTURBANCE CURRENTLY ENTERING NEW MEXICO. THIS FEATURE INITIALLY WAS NOT SAMPLED WELL BY THE GUIDANCE AS IT WAS OFF THE COAST OF BAJA CALIFORNIA. IT SHOWED UP BETTER IN THE 12Z UPPER AIR ANALYSIS AS A MID LEVEL COLD POCKET OVER TUCSON ARIZONA THIS MORNING AND NOW APPEARS TO BE APPROACHING FAR WEST TEXAS. 12Z GUIDANCE APPEARS TO GENERATE SIGNIFICANTLY MORE FORCING FOR ASCENT WITH THIS FEATURE THIS AFTERNOON DURING PEAK HEATING. BY 00Z A DRYLINE SHOULD BE LOCATED ACROSS THE PANHANDLE AS THE STRONGEST FORCING OVERSPREADS IT. SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY LATE AFTERNOON/EARLY EVENING IN AN AREA OF MODERATE INSTABILITY WITH VERY STEEP MID LEVEL LAPSE RATES. THIS SCENARIO WOULD SUPPORT A LARGE HAIL AND DAMAGING WIND THREAT MAINLY ACROSS NORTHWEST TEXAS. IT NOW APPEARS THAT AS THIS FORCING SPREADS EAST...CAPPING ACROSS NORTH TEXAS WILL RAPIDLY WEAKEN AND A CLUSTER OF THUNDERSTORMS WILL SPREAD EAST. THE COVERAGE AND INTENSITY DOES REMAIN SOMEWHAT IN QUESTION FARTHER EAST THOUGH DESPITE AN ERODING CAP. STORMS MAY TEND TO BECOME ELEVATED AS THE BOUNDARY LAYER COOLS AFTER SUNSET. WILL BE ASSESSING SOME HIGH RES GUIDANCE THROUGH EARLY AFTERNOON AND WILL LIKELY UP POPS DURING THE OVERNIGHT TIMEFRAME ACROSS NORTH TEXAS. DUNN && .AVIATION... MVFR CEILINGS ARE EXPECTED THROUGH 18-19Z BEFORE CLOUDS LIFT ABOVE 3000 FEET. SOUTH WINDS 10-16 KNOTS WILL PREVAIL. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP TO THE NORTHWEST OF NORTH TEXAS LATE AFTERNOON/EARLY EVENING AND THEN MOVE SOUTHEAST TONIGHT. THE CHANCES ARE NOT HIGH ENOUGH TO MENTION TSRA IN THE TAFS AT THIS TIME...BUT HAVE PLACED VCSH IN THE METROPLEX TAFS SITES FOR THE 03Z THROUGH 08Z PERIOD. MVFR CEILINGS ARE EXPECTED TO SPREAD BACK NORTH AFTER 07Z AT WACO...AND AFTER 08Z IN THE METROPLEX. 58 && .PREV DISCUSSION... /ISSUED 350 AM CDT FRI MAR 29 2013/ LATEST UPPER AIR ANALYSIS SHOWS TROUGHS OF LOW PRESSURE ACROSS THE NORTHEASTERN CONUS AND NORTHWESTERN CANADA. A SHORTWAVE CAN BE SEEN MOVING ONSHORE BAJA CALIFORNIA AND THIS DISTURBANCE WILL BE THE MAIN FOCUS FOR THE NEXT 24 HOURS. ON THE SURFACE...A LOW CENTER REMAINS POSITIONED NEAR THE TEXAS PANHANDLE WITH A TROUGH EXTENDING TO THE EAST INTO OKLAHOMA. THE 00Z FWD RAOB INDICATED A STOUT CAP IN PLACE AS WEST WINDS BETWEEN 700 AND 800 MB ARE LEADING TO WARM AIR ADVECTION. THIS CAP WILL KEEP NORTH TEXAS RAIN FREE FOR MOST OF THE DAY TODAY. THE FORECAST THEN BECOMES PROBLEMATIC AS THE SHORTWAVE NEARS THE REGION THIS EVENING. THE MODELS DIFFER ON THE HANDLING OF THIS SYSTEM AND THE WEAKENING OF THE CAP BY LATE AFTERNOON. THE GFS KEEPS THE CAP IN PLACE AND MOST OF THE AREA RAIN FREE...WHILE THE NAM/WRF/CANADIAN/ECMWF ALL WEAKEN THE CAP TO SOME DEGREE. THE NAM IS THE MOST AGGRESSIVE WITH THE REMOVAL OF THE CAP COMPLETELY BY 00Z. CURRENTLY ON WATER VAPOR THE SHORTWAVE LOOKS STRONGER THAN WHAT MOST MODELS HAVE INITIALIZED. THE DISTURBANCE IS STRONG ENOUGH THAT IT CAN BE SEEN ON CONSTANT PV SURFACES AS THE TROPOPAUSE DESCENDS IN THE ATMOSPHERE WITHIN THE CENTER OF THE TROUGH OF LOW PRESSURE. THE 00-HR RAP IS CURRENTLY INITIALIZING THIS TO OCCUR AT 330 MB...WHILE THE GFS AND NAM ARE AT 280 MB AND 295 MB RESPECTIVELY. WITH THE STRONGER TROUGH...WILL HOLD MORE WEIGHT WITH THE NAMS FORECAST OF ERODING THE CAP THIS AFTERNOON. HIGH-RES MODELS ARE INITIALIZING THUNDERSTORM DEVELOPMENT WEST/NORTHWEST OF THE FORECAST AREA...NEAR THE SURFACE LOW BEFORE 00Z THIS EVENING. PREVIOUS THINKING WAS THE CAP WOULD HOLD AND THESE STORMS WOULD WEAKEN AS THEY PROGRESSED EAST...RUNNING INTO THE CAP. IF THE CAP DOES ERODE...THERE SHOULD BE A DECENT COVERAGE OF STORMS INTO THE NORTHWEST ZONES AFTER 00Z. WITH CAPE VALUES NEAR 1500 J/KG AND MODERATE SHEAR VALUES A STRONG TO MARGINALLY SEVERE STORM IS POSSIBLE. OVERNIGHT...A COMPLEX OF STORMS IS EXPECTED TO DEVELOP NEAR THE SURFACE TROUGH IN OKLAHOMA AND THIS ACTIVITY COULD CLIP OUR NORTHEASTERN ZONES NEAR SUNRISE SATURDAY. AFTER THIS SYSTEM MOVES OUT ON SATURDAY...THINK THE REMAINDER OF THE DAY SHOULD BE RELATIVELY QUIET AS NO LARGE SCALE FORCING FOR ASCENT IS IN PLACE. SATURDAY NIGHT...THE TROUGH THAT IS CURRENTLY IN NORTHWESTERN CANADA WILL CONTINUE TO SLIDE SOUTHEAST AND SEND A COLD FRONT INTO SOUTHERN OKLAHOMA. THIS FRONT COMBINING WITH ANOTHER WEAK EMBEDDED SHORTWAVE WILL BRING MORE THUNDERSTORM CHANCES TO MAINLY THE NORTHERN ZONES. THIS FRONTAL BOUNDARY IS EXPECTED TO STALL NEAR THE I-20 CORRIDOR SUNDAY AFTERNOON AS THE UPPER LOW SHIFTS EAST. WITH THE SURFACE FOCUS IN PLACE FOR THE CWA...ADDITIONAL THUNDERSTORMS ARE POSSIBLE FOR THE AREA. CAPE VALUES MAY EXCEED 2000 J/KG AS LOWER 60 DEWPOINTS WILL BE IN PLACE. SHEAR IS EXPECTED TO BE WEAKER AND THIS WILL LIMIT THE OVERALL SEVERE POTENTIAL...BUT CANT RULE OUT A STRONG OR MARGINALLY SEVERE STORM SUNDAY AFTERNOON. ANOTHER SOUTHWARD MOVING IMPULSE OF UPPER ENERGY OUT OF CANADA WILL SEND A STRONGER FRONT SOUTH ON MONDAY. THIS FRONT IS EXPECTED TO MOVE THROUGH THE CWA MONDAY EVENING AND WILL CARRY ADDITIONAL THUNDERSTORM CHANCES WITH THE FROPA. MEDIUM RANGE GUIDANCE HAS HAD POOR RUN-TO-RUN CONSISTENCY WITH THE HANDLING OF FEATURES BEYOND MONDAY. THE 00Z GFS AND ECMWF ARE SIMILAR AND KEEP STRONG UPGLIDE ON TOP OF THE FRONTAL INVERSION THROUGH TUESDAY NIGHT AND WILL KEEP SLIGHT TO CHANCE POPS FOR LIGHT RAIN IN THE FORECAST. AFTER A VERY ACTIVE PERIOD...THE FINAL CHANCE OF RAIN WILL COME WHEN THE UPPER TROUGH CURRENTLY OVER THE PACIFIC OCEAN WILL SWING THROUGH THE AREA WEDNESDAY/WEDNESDAY NIGHT. MODELS LAST NIGHT SHOWED THIS LOW WEAKENING BEFORE IT MOVED THROUGH...BUT TONIGHT KEEP IT AS A STRONGER CLOSED LOW. THE TRACK OF THE LOW IS DIFFERENT BETWEEN THE GFS AND ECMWF...BUT BOTH SHOW LARGE SCALE FORCING FOR ASCENT AND WILL FORECAST 30 POPS FOR WEDNESDAY AND WEDNESDAY NIGHT. AGAIN...MODELS HAVE HAD A HARD TIME WITH THE FORECAST BEYOND MONDAY AND CONFIDENCE IS NOT HIGH. NEVERTHELESS...AN UNSETTLED WEATHER PATTERN IS EXPECTED BETWEEN TODAY AND NEXT WEDNESDAY WITH RAIN CHANCES IN THE FORECAST EACH DAY FOR MOST OF THE AREA. IT WONT RAIN EVERYDAY FOR ALL LOCATIONS...BUT CHANCES ARE THERE EACH DAY. TEMPERATURES THROUGH MONDAY WILL BE IN THE 70S/80S FOR HIGHS WITH LOWS IN THE 50S/60S. AFTER MONDAY...TEMPERATURES WILL BE DRASTICALLY COLDER BEHIND THE FRONT. HIGHS BEHIND THE FRONT TUESDAY AND WEDNESDAY WILL BE IN THE 40S/50S FOR HIGHS WITH LITTLE DIURNAL RANGE GIVEN THE CLOUD COVER AND RAIN CHANCES. SOUTH WINDS WILL RETURN BY THE END OF THE WEEK AND MODERATING TEMPERATURES CAN BE EXPECTED. HAMPSHIRE && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 77 62 80 62 76 / 10 30 20 40 40 WACO, TX 77 61 79 64 79 / 5 20 20 20 40 PARIS, TX 73 58 75 60 74 / 20 50 30 50 40 DENTON, TX 75 61 80 58 75 / 10 30 20 40 40 MCKINNEY, TX 75 61 80 60 76 / 10 30 20 40 40 DALLAS, TX 77 62 81 63 76 / 10 30 20 40 40 TERRELL, TX 76 62 79 63 75 / 10 30 20 30 40 CORSICANA, TX 76 60 77 62 78 / 10 20 20 20 40 TEMPLE, TX 76 61 78 62 81 / 5 10 20 20 30 MINERAL WELLS, TX 77 57 83 59 78 / 10 40 20 30 40 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
547 PM CDT FRI MAR 29 2013 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND SATURDAY ISSUED AT 236 PM CDT FRI MAR 29 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE STRETCHING FROM THE SOUTHEAST CONUS TO THE WESTERN GREAT LAKES EARLY THIS AFTERNOON. MID-LEVEL CLOUD DECK IS SLOWLY MOVING EAST OVER WESTERN WISCONSIN AND IS APPROACHING CENTRAL WISCONSIN. A FEW SPRINKLES HAVE BEEN REPORTED OVER MINNESOTA OUT OF THIS CLOUD DECK BUT AIRMASS IS COMPARATIVELY DRIER OVER CENTRAL WISCONSIN...SO WILL KEEP ANY MENTION OF SPRINKLES OUT OF THE FORECAST. SHORTWAVE TROUGH... WHICH WILL BRING THE NEXT CHANCE OF PRECIP TOMORROW...IS JUST ENTERING THE WESTERN DAKOTAS. AS THIS WAVE AND ATTENDANT COLD FRONT APPROACHES...PRECIP CHANCES ARE THE MAIN FORECAST CONCERN. TONIGHT...SURFACE HIGH PRESSURE WILL MOVE FROM THE CENTRAL TO THE EASTERN GREAT LAKES...WHILE A SHEARED SHORTWAVE WILL PUSH A COOL FRONT ACROSS THE NORTHERN PLAINS INTO THE NORTHERN MISSISSIPPI VALLEY. SCT TO BKN LOW TO MID-DECK UPSTREAM WILL GRADUALLY MOVE NORTHEAST THROUGH THE NIGHT...BUT DEEPER MOISTURE WILL NOT ARRIVE INTO NORTHWEST WISCONSIN UNTIL LATE TONIGHT. SOUTH TO SOUTHWEST LOW LEVEL WINDS WILL ADVECT IN DRY AIR FROM THE RECEDING AIRMASS...WHICH WILL CAUSE LEVELS BELOW 5-6KFT TO STRUGGLE TO SATURATE. FIRST THOUGHT WAS TO DELAY PRECIP CHANCES BECAUSE OF THIS DRY AIR...BUT AREAS ACROSS THE NORTH MAY STILL REACH ENOUGH SATURATION FOR LIGHT RAIN TO ARRIVE AFTER 09Z. SO WILL TREND A LITTLE SLOWER WITH THE PRECIP CHANCES OVER CENTRAL AND NORTHEAST WISCONSIN...WHICH WILL KEEP THE SE HALF OF THE AREA DRY BEFORE 15Z. THE DRY AIR SHOULD ALLOW TEMPS TO FALL QUICKLY THIS EVENING AND WILL HAVE LOWS AROUND MIDNIGHT...THEN TEMPS SHOULD RISE AS THICKENING CLOUDS ARRIVE. WET BULB TEMPS LOOK TO BE SLIGHTLY ABOVE FREEZING OVER N-C WISCONSIN BY THE TIME THE PRECIP ARRIVES...SO WILL KEEP A MENTION OF FREEZING RAIN OUT OF THE FORECAST. THOUGH WILL MENTION TO THE EVENING CREW TO WATCH TEMPS CLOSELY. LOWS IN THE UPPER 20S TO LOW 30S. SATURDAY...WEAK SHORTWAVE WILL MOVE FROM NORTHERN MINNESOTA TO EASTERN LAKE SUPERIOR AND WILL PUSH THE COOL FRONT ACROSS MOST OF THE STATE EXCEPT FOR EASTERN WISCONSIN. WARM ADVECTION PRECIP OVER NORTH-CENTRAL WISCONSIN WILL LIFT NORTH INTO THE UPPER PENINSULA DURING THE EARLY MORNING. THEN THE 850MB THETAE AXIS WILL SHIFT INTO CENTRAL WISCONSIN BY 15Z AND INTO EASTERN WISCONSIN AFTER 18Z. PRECIP AMOUNTS SHOULD RANGE FROM A QUARTER TO A HALF INCH. HIGHS MAINLY IN THE LOW TO MID 40S. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY ISSUED AT 236 PM CDT FRI MAR 29 2013 MODELS SHOWED A COLD FRONT...THAT WAS MOVING ACROSS WISCONSIN...EXTENDING FROM NORTHEAST TO SOUTHWEST WISCONSIN AT 00Z SUNDAY. HAVE KEPT LIKELY POPS FOR THE SOUTHEAST PART OF THE AREA DURING THE EARLY PART OF THE EVENING...BUT THEN DOWN TO CHANCE POPS BY LATE EVENING. HAVE A SLIGHT CHANCE FOR SNOW SHOWERS ACROSS THE FAR NORTH LATE IN THE NIGHT AS COLD AIR PASSES OVER THE WARMER LAKE SUPERIOR WATERS IN CYCLONIC FLOW. SNOW AND/OR RAIN SHOWERS REMAIN POSSIBLE ON SUNDAY AS A SECONDARY COLD FRONT PUSHES THROUGH WISCONSIN. THERE WILL BE A CHANCE OF SNOW SHOWERS SUNDAY NIGHT AND MONDAY BUT THEY SHOULD MAINLY BE CONFINED TO VILAS COUNTY AS WINDS BECOME LESS FAVORABLE FOR LAKE EFFECT IN MOST LOCATIONS. CLOUDS AND THE COLD FRONT SHOULD KEEP TEMPERATURES MAINLY IN THE 30S IN THE FAR NORTH ON SUNDAY...AND THE ENTIRE AREA MONDAY AND TUESDAY. A SURFACE HIGH AND UPPER LEVEL RIDGE WILL BRING DRIER CONDITIONS TO THE AREA FOR THE MIDDLE PART OF THE WEEK AND TEMPERATURES SHOULD WARM UP A BIT WITH LESS CLOUD COVER. RETURN FLOW AROUND THE HIGH SHOULD BRING NEAR NORMAL TEMPERATURES TO THE AREA ON THURSDAY. ANOTHER SYSTEM APPROACHING THE AREA WILL BRING A SLIGHT CHANCE OF PRECIPITATION FOR FRIDAY. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 545 PM CDT FRI MAR 29 2013 WL CARRY LOW-END LLWS IN ALL THE TAFS LATE TNGT AS SSWLY FLOW ALOFT INCREASES. EXPECT BAND OF SHRA TO WORK ACRS THE AREA SAT. CIGS MAY HOLD UP INITIALLY AS LOW-LEVELS WL START OUT DRY. A BETTER CHC AT LOWER CIGS DEVELOPING IN THE WAKE OF THE MAIN RAIN BAND AS WINDS DECR NEAR FRONTAL BOUNDARY. && .HYDROLOGY... ISSUED AT 236 PM CDT FRI MAR 29 2013 EXPECT MILD TEMPERATURES FOR THE NEXT TWO DAYS...WITH HIGHS IN MID TO UPPER 40S OVER THE FORECAST AREA. THIS WILL CONTINUE THE GRADUAL MELTING OF THE SNOWPACK. RAIN IS EXPECTED SATURDAY INTO SATURDAY EVENING...WITH PCPN AMOUNTS OF A QUARTER TO HALF INCH POSSIBLE. GIVEN THIS SCENARIO...THE EXPECTED RUNOFF SHOULD CAUSE A GRADUAL RISE IN THE RIVERS OVER THE FORECAST AREA THIS WEEKEND. A FEW RIVERS IN EAST CENTRAL WISCONSIN COULD EXCEED BANKFULL. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......MG AVIATION.......SKOWRONSKI HYDROLOGY......MPC
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND SATURDAY ISSUED AT 236 PM CDT FRI MAR 29 2013 LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE STRETCHING FROM THE SOUTHEAST CONUS TO THE WESTERN GREAT LAKES EARLY THIS AFTERNOON. MID-LEVEL CLOUD DECK IS SLOWLY MOVING EAST OVER WESTERN WISCONSIN AND IS APPROACHING CENTRAL WISCONSIN. A FEW SPRINKLES HAVE BEEN REPORTED OVER MINNESOTA OUT OF THIS CLOUD DECK BUT AIRMASS IS COMPARATIVELY DRIER OVER CENTRAL WISCONSIN...SO WILL KEEP ANY MENTION OF SPRINKLES OUT OF THE FORECAST. SHORTWAVE TROUGH... WHICH WILL BRING THE NEXT CHANCE OF PRECIP TOMORROW...IS JUST ENTERING THE WESTERN DAKOTAS. AS THIS WAVE AND ATTENDANT COLD FRONT APPROACHES...PRECIP CHANCES ARE THE MAIN FORECAST CONCERN. TONIGHT...SURFACE HIGH PRESSURE WILL MOVE FROM THE CENTRAL TO THE EASTERN GREAT LAKES...WHILE A SHEARED SHORTWAVE WILL PUSH A COOL FRONT ACROSS THE NORTHERN PLAINS INTO THE NORTHERN MISSISSIPPI VALLEY. SCT TO BKN LOW TO MID-DECK UPSTREAM WILL GRADUALLY MOVE NORTHEAST THROUGH THE NIGHT...BUT DEEPER MOISTURE WILL NOT ARRIVE INTO NORTHWEST WISCONSIN UNTIL LATE TONIGHT. SOUTH TO SOUTHWEST LOW LEVEL WINDS WILL ADVECT IN DRY AIR FROM THE RECEDING AIRMASS...WHICH WILL CAUSE LEVELS BELOW 5-6KFT TO STRUGGLE TO SATURATE. FIRST THOUGHT WAS TO DELAY PRECIP CHANCES BECAUSE OF THIS DRY AIR...BUT AREAS ACROSS THE NORTH MAY STILL REACH ENOUGH SATURATION FOR LIGHT RAIN TO ARRIVE AFTER 09Z. SO WILL TREND A LITTLE SLOWER WITH THE PRECIP CHANCES OVER CENTRAL AND NORTHEAST WISCONSIN...WHICH WILL KEEP THE SE HALF OF THE AREA DRY BEFORE 15Z. THE DRY AIR SHOULD ALLOW TEMPS TO FALL QUICKLY THIS EVENING AND WILL HAVE LOWS AROUND MIDNIGHT...THEN TEMPS SHOULD RISE AS THICKENING CLOUDS ARRIVE. WET BULB TEMPS LOOK TO BE SLIGHTLY ABOVE FREEZING OVER N-C WISCONSIN BY THE TIME THE PRECIP ARRIVES...SO WILL KEEP A MENTION OF FREEZING RAIN OUT OF THE FORECAST. THOUGH WILL MENTION TO THE EVENING CREW TO WATCH TEMPS CLOSELY. LOWS IN THE UPPER 20S TO LOW 30S. SATURDAY...WEAK SHORTWAVE WILL MOVE FROM NORTHERN MINNESOTA TO EASTERN LAKE SUPERIOR AND WILL PUSH THE COOL FRONT ACROSS MOST OF THE STATE EXCEPT FOR EASTERN WISCONSIN. WARM ADVECTION PRECIP OVER NORTH-CENTRAL WISCONSIN WILL LIFT NORTH INTO THE UPPER PENINSULA DURING THE EARLY MORNING. THEN THE 850MB THETAE AXIS WILL SHIFT INTO CENTRAL WISCONSIN BY 15Z AND INTO EASTERN WISCONSIN AFTER 18Z. PRECIP AMOUNTS SHOULD RANGE FROM A QUARTER TO A HALF INCH. HIGHS MAINLY IN THE LOW TO MID 40S. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY ISSUED AT 236 PM CDT FRI MAR 29 2013 MODELS SHOWED A COLD FRONT...THAT WAS MOVING ACROSS WISCONSIN...EXTENDING FROM NORTHEAST TO SOUTHWEST WISCONSIN AT 00Z SUNDAY. HAVE KEPT LIKELY POPS FOR THE SOUTHEAST PART OF THE AREA DURING THE EARLY PART OF THE EVENING...BUT THEN DOWN TO CHANCE POPS BY LATE EVENING. HAVE A SLIGHT CHANCE FOR SNOW SHOWERS ACROSS THE FAR NORTH LATE IN THE NIGHT AS COLD AIR PASSES OVER THE WARMER LAKE SUPERIOR WATERS IN CYCLONIC FLOW. SNOW AND/OR RAIN SHOWERS REMAIN POSSIBLE ON SUNDAY AS A SECONDARY COLD FRONT PUSHES THROUGH WISCONSIN. THERE WILL BE A CHANCE OF SNOW SHOWERS SUNDAY NIGHT AND MONDAY BUT THEY SHOULD MAINLY BE CONFINED TO VILAS COUNTY AS WINDS BECOME LESS FAVORABLE FOR LAKE EFFECT IN MOST LOCATIONS. CLOUDS AND THE COLD FRONT SHOULD KEEP TEMPERATURES MAINLY IN THE 30S IN THE FAR NORTH ON SUNDAY...AND THE ENTIRE AREA MONDAY AND TUESDAY. A SURFACE HIGH AND UPPER LEVEL RIDGE WILL BRING DRIER CONDITIONS TO THE AREA FOR THE MIDDLE PART OF THE WEEK AND TEMPERATURES SHOULD WARM UP A BIT WITH LESS CLOUD COVER. RETURN FLOW AROUND THE HIGH SHOULD BRING NEAR NORMAL TEMPERATURES TO THE AREA ON THURSDAY. ANOTHER SYSTEM APPROACHING THE AREA WILL BRING A SLIGHT CHANCE OF PRECIPITATION FOR FRIDAY. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 236 PM CDT FRI MAR 29 2013 HIGH PRESSURE WILL DRIFT SE TODAY...REACHING SOUTHERN LAKE MICHIGAN THIS EVENING. THE HIGH WILL BRING VFR CONDITIONS TO THE FORECAST AREA...WITH INCREASING MID-LEVEL CLOUDS DURING THE EVENING. SOUTH TO SOUTHWEST WINDS WILL BRING AN INCREASE IN MOISTURE LATE TONIGHT... AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE NORTHWEST. THIS SYSTEM WILL BRING SCT RAIN SHOWERS TO MAINLY NC WI AFTER 09Z/SAT. && .HYDROLOGY... ISSUED AT 236 PM CDT FRI MAR 29 2013 EXPECT MILD TEMPERATURES FOR THE NEXT TWO DAYS...WITH HIGHS IN MID TO UPPER 40S OVER THE FORECAST AREA. THIS WILL CONTINUE THE GRADUAL MELTING OF THE SNOWPACK. RAIN IS EXPECTED SATURDAY INTO SATURDAY EVENING...WITH PCPN AMOUNTS OF A QUARTER TO HALF INCH POSSIBLE. GIVEN THIS SCENARIO...THE EXPECTED RUNOFF SHOULD CAUSE A GRADUAL RISE IN THE RIVERS OVER THE FORECAST AREA THIS WEEKEND. A FEW RIVERS IN EAST CENTRAL WISCONSIN COULD EXCEED BANKFULL. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......MG AVIATION.......MPC HYDROLOGY......MPC