Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/13/12


AREA FORECAST DISCUSSION
NWS ALBANY NY
158 PM EDT MON JUN 11 2012 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION THROUGH TODAY...WITH WARM AND SOMEWHAT HUMID CONDITIONS THROUGH TONIGHT. AN ISOLATED AFTERNOON SHOWER OR THUNDERSTORM WILL BE POSSIBLE ACROSS PORTIONS OF THE WESTERN MOHAWK VALLEY AND ADIRONDACKS. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL RETURN FOR TUESDAY INTO EARLY WEDNESDAY... ASSOCIATED WITH A PERIOD OF MODERATE TO HEAVY RAINFALL AS A FRONTAL BOUNDARY SLOWLY CROSSES THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1230 PM...ISOLATED CONVECTION HAS DEVELOPED OVER THE ADIRONDACK ZONES SO WILL LEAVE THE SLIGHT CHANCE POPS IN THAT AREA AND THE MOHAWK VALLEY AS WELL. HAVE LEFT HIGH TEMP FORECAST FOR TODAY AS IS...OR RAISED BY A FEW DEGREES...ESPECIALLY ACROSS THE NORTHWEST PART OF THE FORECSAT AREA. ****PREVIOUS DISCUSSION**** AS OF 935 AM EDT...STRATUS CLOUDS CONTINUE TO EXPAND N AND W...ACROSS NW CT...THE MID HUDSON VALLEY REGION AND BERKSHIRES...AS WELL AS ACROSS THE SE CATSKILLS. AREAS OF LOW CLOUDS/FOG ACROSS THE WESTERN ADIRONDACKS...AND PORTIONS OF THE HELDERBERGS APPEARS TO BE DECREASING. HAVE MADE SOME CHANGES TO GRIDDED DATABASE BASED ON RECENT OBS...12Z UA SOUNDINGS...AND LATEST RAP/HRRR. FIRST WAS TO EXPAND THE SLIGHT CHC POPS A BIT FURTHER SOUTH INTO THE CENTRAL AND WESTERN MOHAWK VALLEY. THE LATEST RAP AND HRRR CONTINUE TO INDICATE POCKETS OF FAIRLY DECENT INSTABILITY DEVELOPING THIS AFTERNOON IN THIS REGION. IN ADDITION...THIS REGION WILL BE CLOSER TO A WEAK BOUNDARY...SEPARATING A SLIGHTLY COOLER MODIFIED MARINE AIR MASS TO THE E AND S...FROM A WARMER...MORE CONTINENTAL AIR MASS TO THE N AND W. ELSEWHERE...HAVE INCREASED CLOUDS COVERAGE AND LOWERED MAX TEMPS ACROSS WESTERN NEW ENGLAND...AND THE MID HUDSON VALLEY REGION. AS THE AFOREMENTIONED MODIFIED MARINE AIR CONTINUES TO WORK N AND W...MAX TEMPS MAY FAIL TO REACH 80 ACROSS THE BERKSHIRES/SOUTHERN GREENS...LITCHFIELD CO AND THE MID HUDSON VALLEY. ELSEWHERE...STILL EXPECT MAXES TO REACH 80-85 ACROSS THE UPPER HUDSON VALLEY FROM ALBANY NORTH...AND MID 80S ACROSS THE CENTRAL AND WESTERN MOHAWK VALLEY...WHERE EVEN SOME UPPER 80S ARE POSSIBLE. WILL NEED TO WATCH HOW FAR N AND W THE LOWER CLOUDS REACH...AS THIS MAY REQUIRE ADDITIONAL MODIFICATIONS TO MAX TEMPS/TOWARD LOWER VALUES/WITHIN THE CAPITAL REGION SHOULD MORE CLOUDS FORM. FOR TONIGHT...ANY CONVECTION SHOULD QUICKLY DISSIPATE THIS EVENING AS THE UPPER LEVEL RIDGE AXIS SLIDES FURTHER OFFSHORE. THIS WILL ALLOW THE UPSTREAM NORTHERN PLAINS TROUGH TO MIGRATE FURTHER EAST TOWARD THE CENTRAL GREAT LAKES REGION. ALONG WITH ITS APPROACH...MOISTURE ADVECTION FROM THE SOUTHEAST CONUS AND OHIO VALLEY WILL ADVANCE NORTHWARD. FORECAST SOUNDINGS SUPPORT AN ENTRAINMENT OF LOW LEVEL STRATUS FROM THE ATLANTIC YET RATHER DRY BETWEEN 850-500MB TO KEEP THE CHANCE OF PRECIP WEST OF THE REGION. EXPECTATIONS ARE FOR AN INCREASING CLOUD COVER AND A MILD OVERNIGHT WITH LOWS MAINLY INTO THE 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... RAINFALL POTENTIAL INCREASES FROM WEST TO EAST AS THE LOW LEVEL JET INCREASES TO >40KTS TO ASSIST WITH RAPID MOISTURE TRANSPORT INTO THE CWFA. NCEP MODEL SUITE ARE IN EXCELLENT AGREEMENT WITH A PERIOD OF MODERATE RAINFALL TO MOVE ACROSS THE REGION ON TUESDAY. INSTABILITY PARAMETERS ARE NOT FAVORABLE FOR SEVERE WEATHER...HOWEVER...MID LEVEL VALUES PER THE SHOWALTERS STILL SUPPORT EMBEDDED DEEPER CONVECTION. PWATS ARE PROGGED TO CLIMB IN EXCESS OF 1.75" WITH UPSTREAM VALUES CLOSE TO 2.00". THESE VALUES ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL TO SUPPORT EMBEDDED PERIODS OF HEAVY RAINFALL. FAVORED UPSLOPE REGIONS OF THE CATSKILLS...NW CT INTO THE BERKS AND SOUTHERN VT MAY ENHANCE RAINFALL RATES. SEE THE HYDRO DISCUSSION FOR FURTHER DETAILS ON THE RAINFALL POTENTIAL IMPACTS. OTHERWISE...RATHER HIGH POPS EXPECTED DURING THE DAY WITH TEMPERATURES A BIT COOLER DUE TO THE MARINE INFLUENCE...CLOUDS AND PRECIP WITH HIGHS MAINLY IN THE MID 60S TO LOWER 70S. MODELS HAVE COME AROUND TO THE ECMWF OF THE PAST SEVERAL DAYS WITH A MORE PROGRESSIVE FROPA TUESDAY EVENING. SO WE WILL GRADUALLY LOWER POPS FROM WEST TO EAST ALONG WITH IMPROVEMENTS TO THE SKY COVER. HOWEVER...EAST OF THE HUDSON RIVER...THOSE CLOUDS WILL LIKELY LINGER LONGER UNTIL THE FRONT HAS CLEARED THE EASTERN SEABOARD. CONFIDENCE CONTINUES TO INCREASE THAT WEDNESDAY SHOULD TURN OUT TO BE A DRIER DAY. WHILE THE MID LEVELS OF THE ATMOSPHERE ARE EXPECTED TO REMAIN RATHER DRY...LOWER LEVELS WILL LIKELY REMAIN A BIT MORE MOIST DUE TO THE RAINFALL FROM TUESDAY EVENT AND LOW LEVEL NORTHEAST WIND TRAJECTORIES. SCT-BKN CLOUDS ARE EXPECTED FOR OUT ADJACENT WESTERN NEW ENGLAND COUNTIES WITH DOWNSLOPING COMPONENT INTO THE HUDSON RIVER VALLEY FOR AT LEAST A PTSUNNY DAY. AS FOR TEMPERATURES...A MODEL BLEND APPROACH WAS UTILIZED WHICH DOWNPLAYS THE COOLER VALUES WITHIN THE GFS MOS AND THE MUCH WARMER VALUES SEEN IN THE MET MOS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE MODELS HAVE STARTED TO COME INTO BETTER AGREEMENT REGARDING THE EXTENDED PERIOD...FOR THE PERIOD BEGINNING ON WEDNESDAY EVENING. AT THIS POINT...IT APPEARS THAT THE UPPER TROUGH RESPONSIBLE FOR BRINGING THE MID WEEK WET WEATHER WILL BE PROGRESSIVE AND CONTINUE TO MOVE EASTWARD ACROSS CANADA. ALTHOUGH THE SURFACE FRONTAL BOUNDARY WON/T MAKE A CLEAN SWEEP OUT TO SEA...IT LOOKS TO GENERALLY WASH OUT ACROSS NEW ENGLAND TO THE EAST OF OUR REGION. ALSO...WHILE IT STILL APPEARS THAT A SURFACE WAVE MAY DEVELOP ALONG THIS FRONT...THE LATEST 00 UTC ECMWF/GFS BOTH SHOW A WEAK LOW REMAINING OFF THE COAST...WITH HIGH PRESSURE BUILDING INTO OUR AREA FROM SOUTHERN CANADA. WHILE WE STILL MAY HAVE A LOW CHC/SLIGHT CHC FOR A RAIN SHOWER ACROSS THE REGION /ESP FOR EASTERN AREAS/ FOR WED NIGHT INTO THURSDAY DUE TO THE PROXIMITY OF THE SFC BOUNDARY...IT DOESN/T APPEAR TO BE A WASHOUT BY ANY STRETCH. SKIES LOOK TO RANGE FROM PARTLY CLOUDY IN WESTERN AREAS...TO MOSTLY CLOUDY FOR WESTERN NEW ENGLAND...DUE TO THE WEAK NE SURFACE FLOW IN PLACE. MIN TEMPS LOOK TO RANGE FROM THE MID 40S TO UPPER 50S FOR WED NIGHT...WITH MAX TEMPS GENERALLY IN THE 70S ON THURSDAY. STRONG UPPER RIDGING LOOKS TO BUILD INTO THE REGION FOR FRIDAY INTO THE WEEKEND AS A RIDGE OVER THE GREAT LAKES BENDS NORTHEASTWARD INTO OUR AREA. ALTHOUGH THE MODELS SHOW A CLOSED OFF 500 HPA LOW ACROSS THE WESTERN ATLANTIC...IT LOOKS TO STAY FAR ENOUGH EAST OF OUR AREA TO BE OF ANY CONCERN FOR US. WITH THE BUILDING RIDGE...AND WARMING TEMPS ALOFT...ENOUGH OF A CAP LOOKS TO BE IN PLACE TO PREVENT ANY CONVECTION FROM FIRING UP...SO HAVE GONE WITH A DRY FORECAST FOR FRIDAY ONWARD. VALLEY MAX TEMPS SHOULD BE GRADUALLY WARMER AND WARMER EACH DAY...WITH UPPER 70S TO NEAR 80 FOR FRIDAY...LOW 80S FOR SATURDAY...AND LOW TO MID 80S FOR SUNDAY. SKIES GENERALLY LOOK MOSTLY CLEAR TO PARTLY CLOUDY. AT THIS POINT...DEWPOINTS DON/T LOOK TOO MUGGY JUST YET...WITH TDS GENERALLY IN THE 50S F. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... HIGH PRESSURE WILL REMAIN ANCHORED OFF THE NEW ENGLAND COAST THROUGH TONIGHT. A WARM FRONT APPROACHING FROM THE SOUTHWEST WILL SPREAD CLOUDS...AND SHOWERS INTO THE REGION FOR TUESDAY AFTERNOON AND NIGHT. EXPECT VFR CONDITIONS THROUGH AT LEAST EARLY TONIGHT. THEN...AS A MOIST S/SE FLOW CONTINUES...SOME LOW CLOUDS ARE EXPECTED TO DEVELOP AND SPREAD NORTHWARD AFTER 06Z/TUE. THIS SHOULD LEAD TO MVFR CIGS DEVELOPING PRIOR TO 12Z/TUE...WITH A CHANCE FOR IFR CIGS AT KPSF...AND POSSIBLY KPOU. THERE IS A SLIGHT CHANCE THAT IFR CIGS MAY SPREAD EVEN FURTHER N...BUT AT THIS TIME...CONFIDENCE NOT QUITE HIGH ENOUGH TO INCLUDE AT KALB/KGFL. AREAS OF MVFR CIGS WILL LINGER THROUGH 14Z-15Z/TUE...WITH SOME POSSIBILITY OF IMPROVEMENT INTO THE LOW VFR RANGE THEREAFTER. HOWEVER...SHOWERS SHOULD DEVELOP ACROSS WESTERN AND CENTRAL NYS DURING THE MORNING...AND MAY IMPACT TAF SITES WEST OF THE HUDSON RIVER AFTER 16Z/TUE. SOUTH TO SOUTHEAST WINDS WILL REMAIN AT 8-12 KT THIS AFTERNOON...WITH SOME GUSTS OF 20-25 KT POSSIBLE...ESP AT KALB DUE TO FUNNELING EFFECTS UP THE HUDSON RIVER VALLEY. SOUTH TO SOUTHEAST WINDS WILL DIMINISH TO 5-10 KT TONIGHT...THEN INCREASE AGAIN TO 8-12 KT TUE MORNING...WITH SOME GUSTS OF 20-25 KT POSSIBLE. OUTLOOK... TUE-TUE NT...VFR/MVFR. CHC IFR. AFTERNOON SHRA/TSRA LIKELY. WED...VFR/MVFR. SHRA POSSIBLE EARLY. THU/SAT...VFR. SLIGHT CHC -SHRA. CHC LATE NIGHT/EARLY MORNING MVFR/IFR IN FOG/STRATUS. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. A SOUTH TO SOUTHEAST WIND WILL INCREASE TO AROUND 10 MPH TODAY WITH DRY WEATHER EXPECTED. AFTERNOON RH VALUES WILL DROP INTO THE 35-50 PERCENT...HIGHEST TO THE WEST OF ALBANY. MINIMUM RH VALUES TONIGHT REBOUND TO GREATER THAN 80 PERCENT. A WETTING RAIN IS EXPECTED ON TUESDAY TO FURTHER REDUCE FIRE WEATHER CONCERNS. && .HYDROLOGY... A MODERATE RAINFALL EVENT IS EXPECTED ON TUESDAY ACROSS THE HYDRO SERVICE AREA. LATEST MODEL GUIDANCE SUPPORTS A ROBUST MOISTURE TRANSPORT THAT SHOULD GENERATE AT LEAST BROKEN COVERAGE OF MODERATE TO HEAVY EMBEDDED CONVECTIVE RAINFALL RATES. EXPECTING THE RAINFALL TO BE OROGRAPHICALLY ENHANCED ACROSS PORTIONS OF THE CATSKILLS....BERKSHIRES AND SOUTHERN GREENS. PWAT ANOMALIES OF 2 TO 3 STD DEV ABOVE NORMAL...A >40 KT SOUTHERLY LOW LEVEL JET HELPING TO ENHANCE ISENTROPIC LIFT AND OROGRAPHICS SHOULD HELP ENHANCE RAINFALL RATES...AND THUS EXPECTING SOME LOCALLY HEAVIER TOTALS FOR THE EVENT AT OR ABOVE 2 INCHES. THIS SHOULD PRODUCE RISES ON AREA RIVERS AND STREAMS...BUT NO FLOODING IS EXPECTED ON THE STREAMS AND RIVERS. LATEST RUN OF THE MMEFS GUIDANCE ALSO SUPPORT THIS IDEA WITH NO POINTS EXPECTED TO CLIMB ABOVE FLOOD STAGE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...GJM/KL/BGM NEAR TERM...GJM/KL/BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...KL FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
142 PM EDT MON JUN 11 2012 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION THROUGH TODAY...WITH WARM AND SOMEWHAT HUMID CONDITIONS THROUGH TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL RETURN FOR TUESDAY INTO EARLY WEDNESDAY ASSOCIATED WITH A PERIOD OF MODERATE TO HEAVY RAINFALL AS A FRONTAL BOUNDARY SLOWLY CROSSES THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 935 AM EDT...STRATUS CLOUDS CONTINUE TO EXPAND N AND W...ACROSS NW CT...THE MID HUDSON VALLEY REGION AND BERKSHIRES...AS WELL AS ACROSS THE SE CATSKILLS. AREAS OF LOW CLOUDS/FOG ACROSS THE WESTERN ADIRONDACKS...AND PORTIONS OF THE HELDERBERGS APPEARS TO BE DECREASING. HAVE MADE SOME CHANGES TO GRIDDED DATABASE BASED ON RECENT OBS...12Z UA SOUNDINGS...AND LATEST RAP/HRRR. FIRST WAS TO EXPAND THE SLIGHT CHC POPS A BIT FURTHER SOUTH INTO THE CENTRAL AND WESTERN MOHAWK VALLEY. THE LATEST RAP AND HRRR CONTINUE TO INDICATE POCKETS OF FAIRLY DECENT INSTABILITY DEVELOPING THIS AFTERNOON IN THIS REGION. IN ADDITION...THIS REGION WILL BE CLOSER TO A WEAK BOUNDARY...SEPARATING A SLIGHTLY COOLER MODIFIED MARINE AIR MASS TO THE E AND S...FROM A WARMER...MORE CONTINENTAL AIR MASS TO THE N AND W. ELSEWHERE...HAVE INCREASED CLOUDS COVERAGE AND LOWERED MAX TEMPS ACROSS WESTERN NEW ENGLAND...AND THE MID HUDSON VALLEY REGION. AS THE AFOREMENTIONED MODIFIED MARINE AIR CONTINUES TO WORK N AND W...MAX TEMPS MAY FAIL TO REACH 80 ACROSS THE BERKSHIRES/SOUTHERN GREENS...LITCHFIELD CO AND THE MID HUDSON VALLEY. ELSEWHERE...STILL EXPECT MAXES TO REACH 80-85 ACROSS THE UPPER HUDSON VALLEY FROM ALBANY NORTH...AND MID 80S ACROSS THE CENTRAL AND WESTERN MOHAWK VALLEY...WHERE EVEN SOME UPPER 80S ARE POSSIBLE. WILL NEED TO WATCH HOW FAR N AND W THE LOWER CLOUDS REACH...AS THIS MAY REQUIRE ADDITIONAL MODIFICATIONS TO MAX TEMPS/TOWARD LOWER VALUES/WITHIN THE CAPITAL REGION SHOULD MORE CLOUDS FORM. FOR TONIGHT...ANY CONVECTION SHOULD QUICKLY DISSIPATE THIS EVENING AS THE UPPER LEVEL RIDGE AXIS SLIDES FURTHER OFFSHORE. THIS WILL ALLOW THE UPSTREAM NORTHERN PLAINS TROUGH TO MIGRATE FURTHER EAST TOWARD THE CENTRAL GREAT LAKES REGION. ALONG WITH ITS APPROACH...MOISTURE ADVECTION FROM THE SOUTHEAST CONUS AND OHIO VALLEY WILL ADVANCE NORTHWARD. FORECAST SOUNDINGS SUPPORT AN ENTRAINMENT OF LOW LEVEL STRATUS FROM THE ATLANTIC YET RATHER DRY BETWEEN 850-500MB TO KEEP THE CHANCE OF PRECIP WEST OF THE REGION. EXPECTATIONS ARE FOR AN INCREASING CLOUD COVER AND A MILD OVERNIGHT WITH LOWS MAINLY INTO THE 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... RAINFALL POTENTIAL INCREASES FROM WEST TO EAST AS THE LOW LEVEL JET INCREASES TO >40KTS TO ASSIST WITH RAPID MOISTURE TRANSPORT INTO THE CWFA. NCEP MODEL SUITE ARE IN EXCELLENT AGREEMENT WITH A PERIOD OF MODERATE RAINFALL TO MOVE ACROSS THE REGION ON TUESDAY. INSTABILITY PARAMETERS ARE NOT FAVORABLE FOR SEVERE WEATHER...HOWEVER...MID LEVEL VALUES PER THE SHOWALTERS STILL SUPPORT EMBEDDED DEEPER CONVECTION. PWATS ARE PROGGED TO CLIMB IN EXCESS OF 1.75" WITH UPSTREAM VALUES CLOSE TO 2.00". THESE VALUES ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL TO SUPPORT EMBEDDED PERIODS OF HEAVY RAINFALL. FAVORED UPSLOPE REGIONS OF THE CATSKILLS...NW CT INTO THE BERKS AND SOUTHERN VT MAY ENHANCE RAINFALL RATES. SEE THE HYDRO DISCUSSION FOR FURTHER DETAILS ON THE RAINFALL POTENTIAL IMPACTS. OTHERWISE...RATHER HIGH POPS EXPECTED DURING THE DAY WITH TEMPERATURES A BIT COOLER DUE TO THE MARINE INFLUENCE...CLOUDS AND PRECIP WITH HIGHS MAINLY IN THE MID 60S TO LOWER 70S. MODELS HAVE COME AROUND TO THE ECMWF OF THE PAST SEVERAL DAYS WITH A MORE PROGRESSIVE FROPA TUESDAY EVENING. SO WE WILL GRADUALLY LOWER POPS FROM WEST TO EAST ALONG WITH IMPROVEMENTS TO THE SKY COVER. HOWEVER...EAST OF THE HUDSON RIVER...THOSE CLOUDS WILL LIKELY LINGER LONGER UNTIL THE FRONT HAS CLEARED THE EASTERN SEABOARD. CONFIDENCE CONTINUES TO INCREASE THAT WEDNESDAY SHOULD TURN OUT TO BE A DRIER DAY. WHILE THE MID LEVELS OF THE ATMOSPHERE ARE EXPECTED TO REMAIN RATHER DRY...LOWER LEVELS WILL LIKELY REMAIN A BIT MORE MOIST DUE TO THE RAINFALL FROM TUESDAY EVENT AND LOW LEVEL NORTHEAST WIND TRAJECTORIES. SCT-BKN CLOUDS ARE EXPECTED FOR OUT ADJACENT WESTERN NEW ENGLAND COUNTIES WITH DOWNSLOPING COMPONENT INTO THE HUDSON RIVER VALLEY FOR AT LEAST A PTSUNNY DAY. AS FOR TEMPERATURES...A MODEL BLEND APPROACH WAS UTILIZED WHICH DOWNPLAYS THE COOLER VALUES WITHIN THE GFS MOS AND THE MUCH WARMER VALUES SEEN IN THE MET MOS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE MODELS HAVE STARTED TO COME INTO BETTER AGREEMENT REGARDING THE EXTENDED PERIOD...FOR THE PERIOD BEGINNING ON WEDNESDAY EVENING. AT THIS POINT...IT APPEARS THAT THE UPPER TROUGH RESPONSIBLE FOR BRINGING THE MID WEEK WET WEATHER WILL BE PROGRESSIVE AND CONTINUE TO MOVE EASTWARD ACROSS CANADA. ALTHOUGH THE SURFACE FRONTAL BOUNDARY WON/T MAKE A CLEAN SWEEP OUT TO SEA...IT LOOKS TO GENERALLY WASH OUT ACROSS NEW ENGLAND TO THE EAST OF OUR REGION. ALSO...WHILE IT STILL APPEARS THAT A SURFACE WAVE MAY DEVELOP ALONG THIS FRONT...THE LATEST 00 UTC ECMWF/GFS BOTH SHOW A WEAK LOW REMAINING OFF THE COAST...WITH HIGH PRESSURE BUILDING INTO OUR AREA FROM SOUTHERN CANADA. WHILE WE STILL MAY HAVE A LOW CHC/SLIGHT CHC FOR A RAIN SHOWER ACROSS THE REGION /ESP FOR EASTERN AREAS/ FOR WED NIGHT INTO THURSDAY DUE TO THE PROXIMITY OF THE SFC BOUNDARY...IT DOESN/T APPEAR TO BE A WASHOUT BY ANY STRETCH. SKIES LOOK TO RANGE FROM PARTLY CLOUDY IN WESTERN AREAS...TO MOSTLY CLOUDY FOR WESTERN NEW ENGLAND...DUE TO THE WEAK NE SURFACE FLOW IN PLACE. MIN TEMPS LOOK TO RANGE FROM THE MID 40S TO UPPER 50S FOR WED NIGHT...WITH MAX TEMPS GENERALLY IN THE 70S ON THURSDAY. STRONG UPPER RIDGING LOOKS TO BUILD INTO THE REGION FOR FRIDAY INTO THE WEEKEND AS A RIDGE OVER THE GREAT LAKES BENDS NORTHEASTWARD INTO OUR AREA. ALTHOUGH THE MODELS SHOW A CLOSED OFF 500 HPA LOW ACROSS THE WESTERN ATLANTIC...IT LOOKS TO STAY FAR ENOUGH EAST OF OUR AREA TO BE OF ANY CONCERN FOR US. WITH THE BUILDING RIDGE...AND WARMING TEMPS ALOFT...ENOUGH OF A CAP LOOKS TO BE IN PLACE TO PREVENT ANY CONVECTION FROM FIRING UP...SO HAVE GONE WITH A DRY FORECAST FOR FRIDAY ONWARD. VALLEY MAX TEMPS SHOULD BE GRADUALLY WARMER AND WARMER EACH DAY...WITH UPPER 70S TO NEAR 80 FOR FRIDAY...LOW 80S FOR SATURDAY...AND LOW TO MID 80S FOR SUNDAY. SKIES GENERALLY LOOK MOSTLY CLEAR TO PARTLY CLOUDY. AT THIS POINT...DEWPOINTS DON/T LOOK TOO MUGGY JUST YET...WITH TDS GENERALLY IN THE 50S F. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... HIGH PRESSURE WILL REMAIN ANCHORED OFF THE NEW ENGLAND COAST THROUGH TONIGHT. A WARM FRONT APPROACHING FROM THE SOUTHWEST WILL SPREAD CLOUDS...AND SHOWERS INTO THE REGION FOR TUESDAY AFTERNOON AND NIGHT. EXPECT VFR CONDITIONS THROUGH AT LEAST EARLY TONIGHT. THEN...AS A MOIST S/SE FLOW CONTINUES...SOME LOW CLOUDS ARE EXPECTED TO DEVELOP AND SPREAD NORTHWARD AFTER 06Z/TUE. THIS SHOULD LEAD TO MVFR CIGS DEVELOPING PRIOR TO 12Z/TUE...WITH A CHANCE FOR IFR CIGS AT KPSF...AND POSSIBLY KPOU. THERE IS A SLIGHT CHANCE THAT IFR CIGS MAY SPREAD EVEN FURTHER N...BUT AT THIS TIME...CONFIDENCE NOT QUITE HIGH ENOUGH TO INCLUDE AT KALB/KGFL. AREAS OF MVFR CIGS WILL LINGER THROUGH 14Z-15Z/TUE...WITH SOME POSSIBILITY OF IMPROVEMENT INTO THE LOW VFR RANGE THEREAFTER. HOWEVER...SHOWERS SHOULD DEVELOP ACROSS WESTERN AND CENTRAL NYS DURING THE MORNING...AND MAY IMPACT TAF SITES WEST OF THE HUDSON RIVER AFTER 16Z/TUE. SOUTH TO SOUTHEAST WINDS WILL REMAIN AT 8-12 KT THIS AFTERNOON...WITH SOME GUSTS OF 20-25 KT POSSIBLE...ESP AT KALB DUE TO FUNNELING EFFECTS UP THE HUDSON RIVER VALLEY. SOUTH TO SOUTHEAST WINDS WILL DIMINISH TO 5-10 KT TONIGHT...THEN INCREASE AGAIN TO 8-12 KT TUE MORNING...WITH SOME GUSTS OF 20-25 KT POSSIBLE. OUTLOOK... TUE-TUE NT...VFR/MVFR. CHC IFR. AFTERNOON SHRA/TSRA LIKELY. WED...VFR/MVFR. SHRA POSSIBLE EARLY. THU/SAT...VFR. SLIGHT CHC -SHRA. CHC LATE NIGHT/EARLY MORNING MVFR/IFR IN FOG/STRATUS. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. A SOUTH TO SOUTHEAST WIND WILL INCREASE TO AROUND 10 MPH TODAY WITH DRY WEATHER EXPECTED. AFTERNOON RH VALUES WILL DROP INTO THE 35-50 PERCENT...HIGHEST TO THE WEST OF ALBANY. MINIMUM RH VALUES TONIGHT REBOUND TO GREATER THAN 80 PERCENT. A WETTING RAIN IS EXPECTED ON TUESDAY TO FURTHER REDUCE FIRE WEATHER CONCERNS. && .HYDROLOGY... A MODERATE RAINFALL EVENT IS EXPECTED ON TUESDAY ACROSS THE HYDRO SERVICE AREA. LATEST MODEL GUIDANCE SUPPORTS A ROBUST MOISTURE TRANSPORT THAT SHOULD GENERATE AT LEAST BROKEN COVERAGE OF MODERATE TO HEAVY EMBEDDED CONVECTIVE RAINFALL RATES. EXPECTING THE RAINFALL TO BE OROGRAPHICALLY ENHANCED ACROSS PORTIONS OF THE CATSKILLS....BERKSHIRES AND SOUTHERN GREENS. PWAT ANOMALIES OF 2 TO 3 STD DEV ABOVE NORMAL...A >40 KT SOUTHERLY LOW LEVEL JET HELPING TO ENHANCE ISENTROPIC LIFT AND OROGRAPHICS SHOULD HELP ENHANCE RAINFALL RATES...AND THUS EXPECTING SOME LOCALLY HEAVIER TOTALS FOR THE EVENT AT OR ABOVE 2 INCHES. THIS SHOULD PRODUCE RISES ON AREA RIVERS AND STREAMS...BUT NO FLOODING IS EXPECTED ON THE STREAMS AND RIVERS. LATEST RUN OF THE MMEFS GUIDANCE ALSO SUPPORT THIS IDEA WITH NO POINTS EXPECTED TO CLIMB ABOVE FLOOD STAGE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...KL/BGM NEAR TERM...KL/BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...KL FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1108 AM EDT MON JUN 11 2012 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION THROUGH TODAY...WITH WARM AND SOMEWHAT HUMID CONDITIONS THROUGH TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL RETURN FOR TUESDAY INTO EARLY WEDNESDAY ASSOCIATED WITH A PERIOD OF MODERATE TO HEAVY RAINFALL AS A FRONTAL BOUNDARY SLOWLY CROSSES THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 935 AM EDT...STRATUS CLOUDS CONTINUE TO EXPAND N AND W...ACROSS NW CT...THE MID HUDSON VALLEY REGION AND BERKSHIRES...AS WELL AS ACROSS THE SE CATSKILLS. AREAS OF LOW CLOUDS/FOG ACROSS THE WESTERN ADIRONDACKS...AND PORTIONS OF THE HELDERBERGS APPEARS TO BE DECREASING. HAVE MADE SOME CHANGES TO GRIDDED DATABASE BASED ON RECENT OBS...12Z UA SOUNDINGS...AND LATEST RAP/HRRR. FIRST WAS TO EXPAND THE SLIGHT CHC POPS A BIT FURTHER SOUTH INTO THE CENTRAL AND WESTERN MOHAWK VALLEY. THE LATEST RAP AND HRRR CONTINUE TO INDICATE POCKETS OF FAIRLY DECENT INSTABILITY DEVELOPING THIS AFTERNOON IN THIS REGION. IN ADDITION...THIS REGION WILL BE CLOSER TO A WEAK BOUNDARY...SEPARATING A SLIGHTLY COOLER MODIFIED MARINE AIR MASS TO THE E AND S...FROM A WARMER...MORE CONTINENTAL AIR MASS TO THE N AND W. ELSEWHERE...HAVE INCREASED CLOUDS COVERAGE AND LOWERED MAX TEMPS ACROSS WESTERN NEW ENGLAND...AND THE MID HUDSON VALLEY REGION. AS THE AFOREMENTIONED MODIFIED MARINE AIR CONTINUES TO WORK N AND W...MAX TEMPS MAY FAIL TO REACH 80 ACROSS THE BERKSHIRES/SOUTHERN GREENS...LITCHFIELD CO AND THE MID HUDSON VALLEY. ELSEWHERE...STILL EXPECT MAXES TO REACH 80-85 ACROSS THE UPPER HUDSON VALLEY FROM ALBANY NORTH...AND MID 80S ACROSS THE CENTRAL AND WESTERN MOHAWK VALLEY...WHERE EVEN SOME UPPER 80S ARE POSSIBLE. WILL NEED TO WATCH HOW FAR N AND W THE LOWER CLOUDS REACH...AS THIS MAY REQUIRE ADDITIONAL MODIFICATIONS TO MAX TEMPS/TOWARD LOWER VALUES/WITHIN THE CAPITAL REGION SHOULD MORE CLOUDS FORM. FOR TONIGHT...ANY CONVECTION SHOULD QUICKLY DISSIPATE THIS EVENING AS THE UPPER LEVEL RIDGE AXIS SLIDES FURTHER OFFSHORE. THIS WILL ALLOW THE UPSTREAM NORTHERN PLAINS TROUGH TO MIGRATE FURTHER EAST TOWARD THE CENTRAL GREAT LAKES REGION. ALONG WITH ITS APPROACH...MOISTURE ADVECTION FROM THE SOUTHEAST CONUS AND OHIO VALLEY WILL ADVANCE NORTHWARD. FORECAST SOUNDINGS SUPPORT AN ENTRAINMENT OF LOW LEVEL STRATUS FROM THE ATLANTIC YET RATHER DRY BETWEEN 850-500MB TO KEEP THE CHANCE OF PRECIP WEST OF THE REGION. EXPECTATIONS ARE FOR AN INCREASING CLOUD COVER AND A MILD OVERNIGHT WITH LOWS MAINLY INTO THE 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... RAINFALL POTENTIAL INCREASES FROM WEST TO EAST AS THE LOW LEVEL JET INCREASES TO >40KTS TO ASSIST WITH RAPID MOISTURE TRANSPORT INTO THE CWFA. NCEP MODEL SUITE ARE IN EXCELLENT AGREEMENT WITH A PERIOD OF MODERATE RAINFALL TO MOVE ACROSS THE REGION ON TUESDAY. INSTABILITY PARAMETERS ARE NOT FAVORABLE FOR SEVERE WEATHER...HOWEVER...MID LEVEL VALUES PER THE SHOWALTERS STILL SUPPORT EMBEDDED DEEPER CONVECTION. PWATS ARE PROGGED TO CLIMB IN EXCESS OF 1.75" WITH UPSTREAM VALUES CLOSE TO 2.00". THESE VALUES ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL TO SUPPORT EMBEDDED PERIODS OF HEAVY RAINFALL. FAVORED UPSLOPE REGIONS OF THE CATSKILLS...NW CT INTO THE BERKS AND SOUTHERN VT MAY ENHANCE RAINFALL RATES. SEE THE HYDRO DISCUSSION FOR FURTHER DETAILS ON THE RAINFALL POTENTIAL IMPACTS. OTHERWISE...RATHER HIGH POPS EXPECTED DURING THE DAY WITH TEMPERATURES A BIT COOLER DUE TO THE MARINE INFLUENCE...CLOUDS AND PRECIP WITH HIGHS MAINLY IN THE MID 60S TO LOWER 70S. MODELS HAVE COME AROUND TO THE ECMWF OF THE PAST SEVERAL DAYS WITH A MORE PROGRESSIVE FROPA TUESDAY EVENING. SO WE WILL GRADUALLY LOWER POPS FROM WEST TO EAST ALONG WITH IMPROVEMENTS TO THE SKY COVER. HOWEVER...EAST OF THE HUDSON RIVER...THOSE CLOUDS WILL LIKELY LINGER LONGER UNTIL THE FRONT HAS CLEARED THE EASTERN SEABOARD. CONFIDENCE CONTINUES TO INCREASE THAT WEDNESDAY SHOULD TURN OUT TO BE A DRIER DAY. WHILE THE MID LEVELS OF THE ATMOSPHERE ARE EXPECTED TO REMAIN RATHER DRY...LOWER LEVELS WILL LIKELY REMAIN A BIT MORE MOIST DUE TO THE RAINFALL FROM TUESDAY EVENT AND LOW LEVEL NORTHEAST WIND TRAJECTORIES. SCT-BKN CLOUDS ARE EXPECTED FOR OUT ADJACENT WESTERN NEW ENGLAND COUNTIES WITH DOWNSLOPING COMPONENT INTO THE HUDSON RIVER VALLEY FOR AT LEAST A PTSUNNY DAY. AS FOR TEMPERATURES...A MODEL BLEND APPROACH WAS UTILIZED WHICH DOWNPLAYS THE COOLER VALUES WITHIN THE GFS MOS AND THE MUCH WARMER VALUES SEEN IN THE MET MOS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE MODELS HAVE STARTED TO COME INTO BETTER AGREEMENT REGARDING THE EXTENDED PERIOD...FOR THE PERIOD BEGINNING ON WEDNESDAY EVENING. AT THIS POINT...IT APPEARS THAT THE UPPER TROUGH RESPONSIBLE FOR BRINGING THE MID WEEK WET WEATHER WILL BE PROGRESSIVE AND CONTINUE TO MOVE EASTWARD ACROSS CANADA. ALTHOUGH THE SURFACE FRONTAL BOUNDARY WON/T MAKE A CLEAN SWEEP OUT TO SEA...IT LOOKS TO GENERALLY WASH OUT ACROSS NEW ENGLAND TO THE EAST OF OUR REGION. ALSO...WHILE IT STILL APPEARS THAT A SURFACE WAVE MAY DEVELOP ALONG THIS FRONT...THE LATEST 00 UTC ECMWF/GFS BOTH SHOW A WEAK LOW REMAINING OFF THE COAST...WITH HIGH PRESSURE BUILDING INTO OUR AREA FROM SOUTHERN CANADA. WHILE WE STILL MAY HAVE A LOW CHC/SLIGHT CHC FOR A RAIN SHOWER ACROSS THE REGION /ESP FOR EASTERN AREAS/ FOR WED NIGHT INTO THURSDAY DUE TO THE PROXIMITY OF THE SFC BOUNDARY...IT DOESN/T APPEAR TO BE A WASHOUT BY ANY STRETCH. SKIES LOOK TO RANGE FROM PARTLY CLOUDY IN WESTERN AREAS...TO MOSTLY CLOUDY FOR WESTERN NEW ENGLAND...DUE TO THE WEAK NE SURFACE FLOW IN PLACE. MIN TEMPS LOOK TO RANGE FROM THE MID 40S TO UPPER 50S FOR WED NIGHT...WITH MAX TEMPS GENERALLY IN THE 70S ON THURSDAY. STRONG UPPER RIDGING LOOKS TO BUILD INTO THE REGION FOR FRIDAY INTO THE WEEKEND AS A RIDGE OVER THE GREAT LAKES BENDS NORTHEASTWARD INTO OUR AREA. ALTHOUGH THE MODELS SHOW A CLOSED OFF 500 HPA LOW ACROSS THE WESTERN ATLANTIC...IT LOOKS TO STAY FAR ENOUGH EAST OF OUR AREA TO BE OF ANY CONCERN FOR US. WITH THE BUILDING RIDGE...AND WARMING TEMPS ALOFT...ENOUGH OF A CAP LOOKS TO BE IN PLACE TO PREVENT ANY CONVECTION FROM FIRING UP...SO HAVE GONE WITH A DRY FORECAST FOR FRIDAY ONWARD. VALLEY MAX TEMPS SHOULD BE GRADUALLY WARMER AND WARMER EACH DAY...WITH UPPER 70S TO NEAR 80 FOR FRIDAY...LOW 80S FOR SATURDAY...AND LOW TO MID 80S FOR SUNDAY. SKIES GENERALLY LOOK MOSTLY CLEAR TO PARTLY CLOUDY. AT THIS POINT...DEWPOINTS DON/T LOOK TOO MUGGY JUST YET...WITH TDS GENERALLY IN THE 50S F. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... A BATCH OF STRATUS CLOUDS OF 3-5 KFT OVER PORTIONS OF THE REGION...ALONG WITH A LIGHT S-SW WIND...PREVENTED ANY IFR FOG FROM DEVELOPING THIS MORNING. SOME MVFR BR IS POSSIBLE FOR A BRIEF TIME AT KPOU...OTHERWISE...VFR CONDITIONS SHOULD CONTINUE AT ALL TAF SITES THIS MORNING. SCT DIURNAL CU WILL DEVELOP WITHIN DAYTIME HEATING BY THE LATE MORNING. SOME PASSING HIGH CIRRUS IS POSSIBLE AS WELL. WITHIN DAYTIME MIXING...SOUTHERLY WINDS WILL AVERAGE AROUND 10 KTS. AN APPROACHING FRONTAL SYSTEM WILL SPREAD MID AND HIGH LEVEL CLOUDS ACROSS THE REGION TONIGHT. IN ADDITION...LIGHT S-SE SFC WINDS WILL CONTINUE AS WELL. THESE TWO FACTORS SHOULD PREVENT ANY RADIATIONAL FOG FROM DEVELOPING...KEEPING FLYING CONDITIONS MAINLY VFR. HOWEVER...THE MOIST SOUTHERLY FLOW MAY ALLOW FOR SOME MVFR STRATUS TO MOVE INTO KPOU FOR THE SECOND HALF OF THE NIGHT. OUTLOOK... TUE-TUE NT...VFR TO MVFR. SHRA/TSRA LIKELY. WED...VFR/MVFR. SHRA POSSIBLE EARLY. THU/FRI...VFR. SLIGHT CHC -SHRA. CHC LATE NIGHT/EARLY MORNING MVFR/IFR IN FOG/STRATUS. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. A SOUTH TO SOUTHEAST WIND WILL INCREASE TO AROUND 10 MPH TODAY WITH DRY WEATHER EXPECTED. AFTERNOON RH VALUES WILL DROP INTO THE 35-50 PERCENT...HIGHEST TO THE WEST OF ALBANY. MINIMUM RH VALUES TONIGHT REBOUND TO GREATER THAN 80 PERCENT. A WETTING RAIN IS EXPECTED ON TUESDAY TO FURTHER REDUCE FIRE WEATHER CONCERNS. && .HYDROLOGY... A MODERATE RAINFALL EVENT IS EXPECTED ON TUESDAY ACROSS THE HYDRO SERVICE AREA. LATEST MODEL GUIDANCE SUPPORTS A ROBUST MOISTURE TRANSPORT THAT SHOULD GENERATE AT LEAST BROKEN COVERAGE OF MODERATE TO HEAVY EMBEDDED CONVECTIVE RAINFALL RATES. EXPECTING THE RAINFALL TO BE OROGRAPHICALLY ENHANCED ACROSS PORTIONS OF THE CATSKILLS....BERKSHIRES AND SOUTHERN GREENS. PWAT ANOMALIES OF 2 TO 3 STD DEV ABOVE NORMAL...A >40 KT SOUTHERLY LOW LEVEL JET HELPING TO ENHANCE ISENTROPIC LIFT AND OROGRAPHICS SHOULD HELP ENHANCE RAINFALL RATES...AND THUS EXPECTING SOME LOCALLY HEAVIER TOTALS FOR THE EVENT AT OR ABOVE 2 INCHES. THIS SHOULD PRODUCE RISES ON AREA RIVERS AND STREAMS...BUT NO FLOODING IS EXPECTED ON THE STREAMS AND RIVERS. LATEST RUN OF THE MMEFS GUIDANCE ALSO SUPPORT THIS IDEA WITH NO POINTS EXPECTED TO CLIMB ABOVE FLOOD STAGE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...KL/BGM NEAR TERM...KL/BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...KL/FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
937 AM EDT MON JUN 11 2012 .SYNOPSIS... HIGH PRESSURE ALOFT WILL BUILD INTO THE REGION THROUGH TODAY...WITH WARM AND SOMEWHAT HUMID CONDITIONS THROUGH TONIGHT. WIDESPREAD SHOWERS AND THUNDERSTORMS WILL RETURN FOR TUESDAY INTO EARLY WEDNESDAY ASSOCIATED WITH A PERIOD OF MODERATE TO HEAVY RAINFALL AS A FRONTAL BOUNDARY SLOWLY CROSSES THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 935 AM EDT...STRATUS CLOUDS CONTINUE TO EXPAND N AND W...ACROSS NW CT...THE MID HUDSON VALLEY REGION AND BERKSHIRES...AS WELL AS ACROSS THE SE CATSKILLS. AREAS OF LOW CLOUDS/FOG ACROSS THE WESTERN ADIRONDACKS...AND PORTIONS OF THE HELDERBERGS APPEARS TO BE DECREASING. HAVE MADE SOME CHANGES TO GRIDDED DATABASE BASED ON RECENT OBS...12Z UA SOUNDINGS...AND LATEST RAP/HRRR. FIRST WAS TO EXPAND THE SLIGHT CHC POPS A BIT FURTHER SOUTH INTO THE CENTRAL AND WESTERN MOHAWK VALLEY. THE LATEST RAP AND HRRR CONTINUE TO INDICATE POCKETS OF FAIRLY DECENT INSTABILITY DEVELOPING THIS AFTERNOON IN THIS REGION. IN ADDITION...THIS REGION WILL BE CLOSER TO A WEAK BOUNDARY...SEPARATING A SLIGHTLY COOLER MODIFIED MARINE AIR MASS TO THE E AND S...FROM A WARMER...MORE CONTINENTAL AIR MASS TO THE N AND W. ELSEWHERE...HAVE INCREASED CLOUDS COVERAGE AND LOWERED MAX TEMPS ACROSS WESTERN NEW ENGLAND...AND THE MID HUDSON VALLEY REGION. AS THE AFOREMENTIONED MODIFIED MARINE AIR CONTINUES TO WORK N AND W...MAX TEMPS MAY FAIL TO REACH 80 ACROSS THE BERKSHIRES/SOUTHERN GREENS...LITCHFIELD CO AND THE MID HUDSON VALLEY. ELSEWHERE...STILL EXPECT MAXES TO REACH 80-85 ACROSS THE UPPER HUDSON VALLEY FROM ALBANY NORTH...AND MID 80S ACROSS THE CENTRAL AND WESTERN MOHAWK VALLEY...WHERE EVEN SOME UPPER 80S ARE POSSIBLE. WILL WIL NEED TO WATCH HOW FAR N AND W THE LOWER CLOUDS REACH...AS THIS MAY REQUIRE ADDITIONAL MODIFICATIONS TO MAX TEMPS/TOWARD LOWER VALUES/WITHIN THE CAPITAL REGION SHOULD MORE CLOUDS FORM. FOR TONIGHT...ANY CONVECTION SHOULD QUICKLY DISSIPATE THIS EVENING AS THE UPPER LEVEL RIDGE AXIS SLIDES FURTHER OFFSHORE. THIS WILL ALLOW THE UPSTREAM NORTHERN PLAINS TROUGH TO MIGRATE FURTHER EAST TOWARD THE CENTRAL GREAT LAKES REGION. ALONG WITH ITS APPROACH...MOISTURE ADVECTION FROM THE SOUTHEAST CONUS AND OHIO VALLEY WILL ADVANCE NORTHWARD. FORECAST SOUNDINGS SUPPORT AN ENTRAINMENT OF LOW LEVEL STRATUS FROM THE ATLANTIC YET RATHER DRY BETWEEN 850-500MB TO KEEP THE CHANCE OF PRECIP WEST OF THE REGION. EXPECTATIONS ARE FOR AN INCREASING CLOUD COVER AND A MILD OVERNIGHT WITH LOWS MAINLY INTO THE 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... RAINFALL POTENTIAL INCREASES FROM WEST TO EAST AS THE LOW LEVEL JET INCREASES TO >40KTS TO ASSIST WITH RAPID MOISTURE TRANSPORT INTO THE CWFA. NCEP MODEL SUITE ARE IN EXCELLENT AGREEMENT WITH A PERIOD OF MODERATE RAINFALL TO MOVE ACROSS THE REGION ON TUESDAY. INSTABILITY PARAMETERS ARE NOT FAVORABLE FOR SEVERE WEATHER...HOWEVER...MID LEVEL VALUES PER THE SHOWALTERS STILL SUPPORT EMBEDDED DEEPER CONVECTION. PWATS ARE PROGGED TO CLIMB IN EXCESS OF 1.75" WITH UPSTREAM VALUES CLOSE TO 2.00". THESE VALUES ARE 2-3 STANDARD DEVIATIONS ABOVE NORMAL TO SUPPORT EMBEDDED PERIODS OF HEAVY RAINFALL. FAVORED UPSLOPE REGIONS OF THE CATSKILLS...NW CT INTO THE BERKS AND SOUTHERN VT MAY ENHANCE RAINFALL RATES. SEE THE HYDRO DISCUSSION FOR FURTHER DETAILS ON THE RAINFALL POTENTIAL IMPACTS. OTHERWISE...RATHER HIGH POPS EXPECTED DURING THE DAY WITH TEMPERATURES A BIT COOLER DUE TO THE MARINE INFLUENCE...CLOUDS AND PRECIP WITH HIGHS MAINLY IN THE MID 60S TO LOWER 70S. MODELS HAVE COME AROUND TO THE ECMWF OF THE PAST SEVERAL DAYS WITH A MORE PROGRESSIVE FROPA TUESDAY EVENING. SO WE WILL GRADUALLY LOWER POPS FROM WEST TO EAST ALONG WITH IMPROVEMENTS TO THE SKY COVER. HOWEVER...EAST OF THE HUDSON RIVER...THOSE CLOUDS WILL LIKELY LINGER LONGER UNTIL THE FRONT HAS CLEARED THE EASTERN SEABOARD. CONFIDENCE CONTINUES TO INCREASE THAT WEDNESDAY SHOULD TURN OUT TO BE A DRIER DAY. WHILE THE MID LEVELS OF THE ATMOSPHERE ARE EXPECTED TO REMAIN RATHER DRY...LOWER LEVELS WILL LIKELY REMAIN A BIT MORE MOIST DUE TO THE RAINFALL FROM TUESDAY EVENT AND LOW LEVEL NORTHEAST WIND TRAJECTORIES. SCT-BKN CLOUDS ARE EXPECTED FOR OUT ADJACENT WESTERN NEW ENGLAND COUNTIES WITH DOWNSLOPING COMPONENT INTO THE HUDSON RIVER VALLEY FOR AT LEAST A PTSUNNY DAY. AS FOR TEMPERATURES...A MODEL BLEND APPROACH WAS UTILIZED WHICH DOWNPLAYS THE COOLER VALUES WITHIN THE GFS MOS AND THE MUCH WARMER VALUES SEEN IN THE MET MOS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE MODELS HAVE STARTED TO COME INTO BETTER AGREEMENT REGARDING THE EXTENDED PERIOD...FOR THE PERIOD BEGINNING ON WEDNESDAY EVENING. AT THIS POINT...IT APPEARS THAT THE UPPER TROUGH RESPONSIBLE FOR BRINGING THE MID WEEK WET WEATHER WILL BE PROGRESSIVE AND CONTINUE TO MOVE EASTWARD ACROSS CANADA. ALTHOUGH THE SURFACE FRONTAL BOUNDARY WON/T MAKE A CLEAN SWEEP OUT TO SEA...IT LOOKS TO GENERALLY WASH OUT ACROSS NEW ENGLAND TO THE EAST OF OUR REGION. ALSO...WHILE IT STILL APPEARS THAT A SURFACE WAVE MAY DEVELOP ALONG THIS FRONT...THE LATEST 00 UTC ECMWF/GFS BOTH SHOW A WEAK LOW REMAINING OFF THE COAST...WITH HIGH PRESSURE BUILDING INTO OUR AREA FROM SOUTHERN CANADA. WHILE WE STILL MAY HAVE A LOW CHC/SLIGHT CHC FOR A RAIN SHOWER ACROSS THE REGION /ESP FOR EASTERN AREAS/ FOR WED NIGHT INTO THURSDAY DUE TO THE PROXIMITY OF THE SFC BOUNDARY...IT DOESN/T APPEAR TO BE A WASHOUT BY ANY STRETCH. SKIES LOOK TO RANGE FROM PARTLY CLOUDY IN WESTERN AREAS...TO MOSTLY CLOUDY FOR WESTERN NEW ENGLAND...DUE TO THE WEAK NE SURFACE FLOW IN PLACE. MIN TEMPS LOOK TO RANGE FROM THE MID 40S TO UPPER 50S FOR WED NIGHT...WITH MAX TEMPS GENERALLY IN THE 70S ON THURSDAY. STRONG UPPER RIDGING LOOKS TO BUILD INTO THE REGION FOR FRIDAY INTO THE WEEKEND AS A RIDGE OVER THE GREAT LAKES BENDS NORTHEASTWARD INTO OUR AREA. ALTHOUGH THE MODELS SHOW A CLOSED OFF 500 HPA LOW ACROSS THE WESTERN ATLANTIC...IT LOOKS TO STAY FAR ENOUGH EAST OF OUR AREA TO BE OF ANY CONCERN FOR US. WITH THE BUILDING RIDGE...AND WARMING TEMPS ALOFT...ENOUGH OF A CAP LOOKS TO BE IN PLACE TO PREVENT ANY CONVECTION FROM FIRING UP...SO HAVE GONE WITH A DRY FORECAST FOR FRIDAY ONWARD. VALLEY MAX TEMPS SHOULD BE GRADUALLY WARMER AND WARMER EACH DAY...WITH UPPER 70S TO NEAR 80 FOR FRIDAY...LOW 80S FOR SATURDAY...AND LOW TO MID 80S FOR SUNDAY. SKIES GENERALLY LOOK MOSTLY CLEAR TO PARTLY CLOUDY. AT THIS POINT...DEWPOINTS DON/T LOOK TOO MUGGY JUST YET...WITH TDS GENERALLY IN THE 50S F. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... A BATCH OF STRATUS CLOUDS OF 3-5 KFT OVER PORTIONS OF THE REGION...ALONG WITH A LIGHT S-SW WIND...PREVENTED ANY IFR FOG FROM DEVELOPING THIS MORNING. SOME MVFR BR IS POSSIBLE FOR A BRIEF TIME AT KPOU...OTHERWISE...VFR CONDITIONS SHOULD CONTINUE AT ALL TAF SITES THIS MORNING. SCT DIURNAL CU WILL DEVELOP WITHIN DAYTIME HEATING BY THE LATE MORNING. SOME PASSING HIGH CIRRUS IS POSSIBLE AS WELL. WITHIN DAYTIME MIXING...SOUTHERLY WINDS WILL AVERAGE AROUND 10 KTS. AN APPROACHING FRONTAL SYSTEM WILL SPREAD MID AND HIGH LEVEL CLOUDS ACROSS THE REGION TONIGHT. IN ADDITION...LIGHT S-SE SFC WINDS WILL CONTINUE AS WELL. THESE TWO FACTORS SHOULD PREVENT ANY RADIATIONAL FOG FROM DEVELOPING...KEEPING FLYING CONDITIONS MAINLY VFR. HOWEVER...THE MOIST SOUTHERLY FLOW MAY ALLOW FOR SOME MVFR STRATUS TO MOVE INTO KPOU FOR THE SECOND HALF OF THE NIGHT. OUTLOOK... TUE-TUE NT...VFR TO MVFR. SHRA/TSRA LIKELY. WED...VFR/MVFR. SHRA POSSIBLE EARLY. THU/FRI...VFR. SLIGHT CHC -SHRA. CHC LATE NIGHT/EARLY MORNING MVFR/IFR IN FOG/STRATUS. && .FIRE WEATHER... NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT SEVERAL DAYS. A SOUTH TO SOUTHEAST WIND WILL INCREASE TO AROUND 10 MPH TODAY WITH DRY WEATHER EXPECTED. AFTERNOON RH VALUES WILL DROP INTO THE 35-50 PERCENT...HIGHEST TO THE WEST OF ALBANY. MINIMUM RH VALUES TONIGHT REBOUND TO GREATER THAN 80 PERCENT. A WETTING RAIN IS EXPECTED ON TUESDAY TO FURTHER REDUCE FIRE WEATHER CONCERNS. && .HYDROLOGY... A MODERATE RAINFALL EVENT IS EXPECTED ON TUESDAY ACROSS THE HYDRO SERVICE AREA. LATEST MODEL GUIDANCE SUPPORTS A ROBUST MOISTURE TRANSPORT THAT SHOULD GENERATE AT LEAST BROKEN COVERAGE OF MODERATE TO HEAVY EMBEDDED CONVECTIVE RAINFALL RATES. EXPECTING THE RAINFALL TO BE OROGRAPHICALLY ENHANCED ACROSS PORTIONS OF THE CATSKILLS....BERKSHIRES AND SOUTHERN GREENS. PWAT ANOMALIES OF 2 TO 3 STD DEV ABOVE NORMAL...A >40 KT SOUTHERLY LOW LEVEL JET HELPING TO ENHANCE ISENTROPIC LIFT AND OROGRAPHICS SHOULD HELP ENHANCE RAINFALL RATES...AND THUS EXPECTING SOME LOCALLY HEAVIER TOTALS FOR THE EVENT AT OR ABOVE 2 INCHES. THIS SHOULD PRODUCE RISES ON AREA RIVERS AND STREAMS...BUT NO FLOODING IS EXPECTED ON THE STREAMS AND RIVERS. LATEST RUN OF THE MMEFS GUIDANCE ALSO SUPPORT THIS IDEA WITH NO POINTS EXPECTED TO CLIMB ABOVE FLOOD STAGE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...KL/BGM NEAR TERM...KL/BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...KL/FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
511 PM CDT MON JUN 11 2012 .DISCUSSION... 320 PM CDT THE FORECAST CONCERNS ARE VERY MINIMAL THROUGH THE REST OF THE WEEK WITH A CONTINUED DRY PATTERN. WILL BE MONITORING FOR A FEW STORMS LATE THIS AFTERNOON INTO EARLY EVENING...OTHERWISE THAT MAY WILL LIKELY BE ALL THAT IS ON THE SCOPE FOR QUITE A WHILE. ISOLATED SHOWERS WITH A FEW STORMS REDEVELOPING OVER COOK COUNTY AND SOUTH ALONG THE IL/IN STATE LINE...WHICH IS ALONG AND JUST AHEAD OF A WEAK CONVERGENT AXIS AND APPARENT SHORT WAVE SEEN ON SATELLITE. MID 80S TEMPERATURES AND UPPER 60S DEW POINTS ALONG AND AHEAD OF THIS CORRIDOR HAS BUILT SURFACE BASED CAPE TO AROUND OR SLIGHTLY OVER 2000 J/KG. THIS CONVECTION SHOULD LAST LONGER THAN THE PREVIOUS ACTIVITY NEAR NOON BEING CLOSER TO THE SHORT WAVE CENTER AND HAVING MORE INSTABILITY TO WORK WITH. UPPER LEVEL WIND SHEAR LOOKS TO BE AROUND A MEAGER 20 KT PER PROFILER ANALYSIS. THE BEHAVIOR OF THE STORM CORES IS LIKELY TO BE SOMEWHAT PULSY WITH INSTABILITY IN THE DRIVERS SEAT...AND WITH LIMITED ATTENDANT SHEAR IT LEAVES ONLY A VERY SMALL CHANCE FOR ANY TYPE OF SEVERE ACTIVITY. THE SYSTEM UPPER TROUGH CENTER IS LOCATED ALONG THE MN/WESTERN QUEBEC BORDER WITH PRIMARY HEIGHT FALLS...THE UPPER JET AXIS...AND ASSOCIATED DEEPER ASCENT MOVING EAST FROM THERE. THIS FORCING HAS AIDED SOME SHOWER DEVELOPMENT ALONG THE SURFACE COLD FRONT IN WESTERN WI. THE COOL FRONT EXTENDS SOUTH FROM THERE WHERE IT WILL MOVE INTO NW IL BY 4 PM AND EAST THROUGH THE FORECAST AREA THIS EVE. THE WIND SHIFT IS GRADUAL FROM WEST SOUTHWEST TO WEST NORTHWEST ALONG THE BOUNDARY...AND IT IS ACTUALLY AHEAD OF THE STRONGEST MOISTURE CONVERGENCE. SO OVERALL CONVERGENCE IS LIMITED AND FEEL THAT WILL BE THE CASE WITH ANY CONVECTION THAT WERE TO TRIGGER ALONG IT...WHICH IS NOW APPEARING DOUBTFUL IN OUR AREA. THE HRRR AND OTHER EXPLICIT CONVECTIVE MODELS AGREE IN THIS LIMITED COVERAGE. THE COOL FRONT WILL MOVE THROUGH THE AREA THIS EVENING AND IT LOOKS LIKE THE BOUNDARY LAYER WILL STAY MIXED AS IT DOES SUCH...WITH SOME GUSTS UP TO 20 MPH AS THE PRESSURE RISE AXIS MOVES THROUGH. SUNNY AND DRY WEATHER WILL THEN ONCE AGAIN BE THE STORY AS CANADIAN HIGH PRESSURE MOVES OVERHEAD TUESDAY NIGHT INTO WEDNESDAY. THE REALLY ONLY WEATHER OF INTEREST FROM DAY TO DAY WILL BE HOW LOW DEW POINTS WILL DROP DURING THE AFTERNOON MIXING...AND TO WHAT DEGREE OF COOLING WILL THERE BE FROM THE LAKE. NORTHWEST WINDS WILL BEGIN TO DECREASE TUESDAY AFTERNOON...POTENTIALLY ALLOWING FOR A SLIGHT LAKE BREEZE INTO IL...BUT LIKELY INTO IN. THIS MAY NOT DEVELOP UNTIL LATE AFTERNOON THOUGH...SO WIDESPREAD HIGHS IN THE MID TO UPPER 70S ARE EXPECTED. UPSTREAM DEW POINTS TODAY HAVE BEEN IN THE LOWER TO MID 40S ACROSS EASTERN SD. THIS AND POSSIBLY EVEN LOWER SHOULD BE REALIZED DURING TUESDAY AFTERNOON WITH PROJECTED MIXING TO 850 MB. THE AFTERNOON HUMIDITY WILL REMAIN LOW...UNDER 25 PERCENT...ON WEDNESDAY AFTERNOON WITH THE SYNOPTIC FLOW TURNING NORTHEAST AND THEN EAST. INFLUENCE FROM THE LAKE WILL LIKELY CONTINUE TO MOVE INTO CHICAGO DURING THE AFTERNOON ALL THE WAY THROUGH SATURDAY. THE UPPER LEVEL HEIGHTS AND LOW-LEVEL THERMAL RIDGE BUILD MORE INTO THE AREA THURSDAY NIGHT INTO SATURDAY. THE EC HAS SHOWN IN THE UPPER LEVEL SW FLOW THAT SHORT WAVE ENERGY IS POSSIBLE WITHIN THIS AND MAY DAMPEN THE RIDGE SLIGHTLY SATURDAY NIGHT INTO SUNDAY...AND HAVE A SMALL CHANCE FOR POPS DURING PART OF THAT TIME. OTHERWISE...HAVE COLLABORATED GOING DRIER THAN POPS AND DEW POINTS FROM GUIDANCE BLENDS IN THE EXTENDED PER PERSISTENCE AND AN OVERALL STAGNANT PATTERN. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * DECREASING TSRA/SHRA THREAT. * GUSTY WSW WINDS SHIFTING TO NW WITH COLD FROPA AROUND 02-03Z. RATZER //DISCUSSION...UPDATED 22Z... ISOLATED SHRA/TSRA WHICH HAD FORMED SOUTHEAST OF ORD/MDW THIS AFTERNOON HAVE WEAKENED AND MOVED OUT OVER SOUTHERN LAKE MICHIGAN. PRE-FRONTAL TROUGH HAS MOVED THROUGH MOST OF TERMINAL AREA...WITH WINDS SHIFTING WEST-SOUTHWEST BEHIND IT. THIS IS EXPECTED TO LIMIT LOW LEVEL CONVERGENCE NECESSARY FOR ADDITIONAL TSRA/SHRA DEVELOPMENT AHEAD OF COLD FRONT AND UPPER TROUGH WHICH WILL MOVE ACROSS THE AREA LATER THIS EVENING. THUS WHILE ISOLATED SHRA/TSRA CANT COMPLETELY BE RULED OUT OF THE REALM OF POSSIBILITY FOR THE NEXT 3-4 HOURS...PROBABILITY OF THIS OCCURRING IS VERY LOW AND WILL NOT CARRY ANY MENTION IN TAFS. AS INDICATED...WINDS SHIFTING MORE WEST-SOUTHWEST WITH SOME GUSTS AROUND 20 KTS BETWEEN PRE- FRONTAL TROUGH AND APPROACHING COLD FRONT...THEN WILL SHIFT WEST- NORTHWEST AFTER COLD FROPA. TIMING OF FRONT IN THE 02-03Z TIME FRAME STILL LOOKS REASONABLE. LATEST GUIDANCE INDICATES LOW LEVEL MIXING MAY SUPPORT GUSTS FOR A FEW HOURS POST FROPA. RATZER PREVIOUS DISCUSSION FROM 18Z... A COLD FRONT LIES ACROSS NORTHWEST WISCONSIN SOUTH INTO CENTRAL IOWA THIS AFTERNOON. ONGOING THUNDERSTORMS CONTINUE ACROSS PORTIONS SOUTHERN MISSOURI INTO CENTRAL ILLINOIS PROVIDING A CANOPY OF CLOUD COVER ACROSS MUCH OF NORTHERN ILLINOIS THIS AFTERNOON. THERE IS SOME CLEARING ACROSS PORTIONS OF EAST CENTRAL ILLINOIS AND NORTHWEST INDIANA WHERE AN AXIS OF MODEST INSTABILITY HAS BEGUN TO DEVELOP. AN UPPER LEVEL DISTURBANCE MOVING ACROSS IOWA EARLY THIS AFTERNOON WILL PUSH EAST ACROSS NORTHERN ILLINOIS WITH THE POTENTIAL FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ACROSS THIS INSTABILITY AXIS MID AFTERNOON. IT APPEARS THE THREAT SHOULD STAY SOUTHEAST/EAST OF ORD/MDW WITH SOME POTENTIAL FOR GYY TO BE IMPACTED OR AT LEAST TO SEE ACTIVITY IN THE VICINITY OF THE TERMINAL. MOVED UP VCTS AT GYY TO START OF TAF GIVEN ACTIVITY CURRENTLY IN THE AREA JUST NORTHWEST OF THE TERMINAL AT 18Z. LATE THIS EVENING...THE COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA WITH WINDS BECOMING NORTHWEST. THERE MAY BE ADDITIONAL THUNDERSTORMS THAT DEVELOP ALONG THE FRONT...BUT GIVEN THE WEAK CONVERGENCE ALONG THE FRONT AND LOSS OF DIURNAL HEATING...EXPECT COVERAGE TO BE ISOLATED TO WIDELY SCATTERED WITH LOW THREAT OF BEING ON STATION. ON TUESDAY...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE NORTHWEST. WILL HAVE TO MONITOR THE POSSIBILITY OF A LAKE BREEZE TURNING WINDS NORTHEAST IN THE CHICAGO AREA LATE IN THE AFTERNOON. BMD/RC //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM-HIGH CONFIDENCE IN WIND TRENDS THROUGH LATE EVENING. * MEDIUM-HIGH CONFIDENCE IN NO ADDITIONAL TSRA/SHRA PRIOR TO COLD FROPA THIS EVENING. RATZER //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH SATURDAY...VFR. SUNDAY...VFR. SLIGHT CHC SHRA/TSRA. BEACHLER && .MARINE... 231 PM CDT A LARGE LOW HAS MOVED INTO HUDSON BAY...WHILE HIGH PRESSURE SITS OFF THE NEW ENGLAND COAST. THE UPPER LEVEL PRESSURE GRADIENT HAS RELAXED...RESULTING IN SOUTH TO SOUTHWEST WINDS 15-25 KT ACROSS THE LAKE THIS AFTERNOON. STRONGEST WINDS AROUND 25 KT WILL CONTINUE TO BE OVER THE NORTHERN HALF OF THE LAKE WHICH IS CLOSER TO THE LOW AND ITS TIGHT PRESSURE GRADIENT. THE LOWS COLD FRONT WILL SWEEP ACROSS THE LAKE TONIGHT. WINDS WILL TURN OUT OF THE WEST AT 15 TO 25 KT ACROSS THE LAKE BEHIND THE FRONT. HIGH PRESSURE MOVES IN BEHIND THE FRONT TUESDAY NIGHT...WITH WINDS DIMINISHING AND BECOMING NORTHERLY FOR A ON TUESDAY. THE LIGHT WINDS WILL CONTINUE TO VEER TO EASTERLY AS THE HIGH MOVES OVER THE LAKE WEDNESDAY. WINDS TURN SOUTHEASTERLY AS THE HIGH MAKES ITS WAY OVER NORTHERN QUEBEC ON THURSDAY. ALTHOUGH THE CENTER OF THE HIGH MOVES OFF TO THE NORTHEAST...A LARGE RIDGE WILL REMAIN OVER THE EASTERN THIRD OF THE US THROUGH THE REMAINING PART OF THE FORECAST PERIOD. THIS PATTERN WILL RESULT IN LIGHT WINDS VARYING BETWEEN EAST AND SOUTH. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 PM CDT MON JUN 11 2012 .DISCUSSION... 320 PM CDT THE FORECAST CONCERNS ARE VERY MINIMAL THROUGH THE REST OF THE WEEK WITH A CONTINUED DRY PATTERN. WILL BE MONITORING FOR A FEW STORMS LATE THIS AFTERNOON INTO EARLY EVENING...OTHERWISE THAT MAY WILL LIKELY BE ALL THAT IS ON THE SCOPE FOR QUITE A WHILE. ISOLATED SHOWERS WITH A FEW STORMS REDEVELOPING OVER COOK COUNTY AND SOUTH ALONG THE IL/IN STATE LINE...WHICH IS ALONG AND JUST AHEAD OF A WEAK CONVERGENT AXIS AND APPARENT SHORT WAVE SEEN ON SATELLITE. MID 80S TEMPERATURES AND UPPER 60S DEW POINTS ALONG AND AHEAD OF THIS CORRIDOR HAS BUILT SURFACE BASED CAPE TO AROUND OR SLIGHTLY OVER 2000 J/KG. THIS CONVECTION SHOULD LAST LONGER THAN THE PREVIOUS ACTIVITY NEAR NOON BEING CLOSER TO THE SHORT WAVE CENTER AND HAVING MORE INSTABILITY TO WORK WITH. UPPER LEVEL WIND SHEAR LOOKS TO BE AROUND A MEAGER 20 KT PER PROFILER ANALYSIS. THE BEHAVIOR OF THE STORM CORES IS LIKELY TO BE SOMEWHAT PULSY WITH INSTABILITY IN THE DRIVERS SEAT...AND WITH LIMITED ATTENDANT SHEAR IT LEAVES ONLY A VERY SMALL CHANCE FOR ANY TYPE OF SEVERE ACTIVITY. THE SYSTEM UPPER TROUGH CENTER IS LOCATED ALONG THE MN/WESTERN QUEBEC BORDER WITH PRIMARY HEIGHT FALLS...THE UPPER JET AXIS...AND ASSOCIATED DEEPER ASCENT MOVING EAST FROM THERE. THIS FORCING HAS AIDED SOME SHOWER DEVELOPMENT ALONG THE SURFACE COLD FRONT IN WESTERN WI. THE COOL FRONT EXTENDS SOUTH FROM THERE WHERE IT WILL MOVE INTO NW IL BY 4 PM AND EAST THROUGH THE FORECAST AREA THIS EVE. THE WIND SHIFT IS GRADUAL FROM WEST SOUTHWEST TO WEST NORTHWEST ALONG THE BOUNDARY...AND IT IS ACTUALLY AHEAD OF THE STRONGEST MOISTURE CONVERGENCE. SO OVERALL CONVERGENCE IS LIMITED AND FEEL THAT WILL BE THE CASE WITH ANY CONVECTION THAT WERE TO TRIGGER ALONG IT...WHICH IS NOW APPEARING DOUBTFUL IN OUR AREA. THE HRRR AND OTHER EXPLICIT CONVECTIVE MODELS AGREE IN THIS LIMITED COVERAGE. THE COOL FRONT WILL MOVE THROUGH THE AREA THIS EVENING AND IT LOOKS LIKE THE BOUNDARY LAYER WILL STAY MIXED AS IT DOES SUCH...WITH SOME GUSTS UP TO 20 MPH AS THE PRESSURE RISE AXIS MOVES THROUGH. SUNNY AND DRY WEATHER WILL THEN ONCE AGAIN BE THE STORY AS CANADIAN HIGH PRESSURE MOVES OVERHEAD TUESDAY NIGHT INTO WEDNESDAY. THE REALLY ONLY WEATHER OF INTEREST FROM DAY TO DAY WILL BE HOW LOW DEW POINTS WILL DROP DURING THE AFTERNOON MIXING...AND TO WHAT DEGREE OF COOLING WILL THERE BE FROM THE LAKE. NORTHWEST WINDS WILL BEGIN TO DECREASE TUESDAY AFTERNOON...POTENTIALLY ALLOWING FOR A SLIGHT LAKE BREEZE INTO IL...BUT LIKELY INTO IN. THIS MAY NOT DEVELOP UNTIL LATE AFTERNOON THOUGH...SO WIDESPREAD HIGHS IN THE MID TO UPPER 70S ARE EXPECTED. UPSTREAM DEW POINTS TODAY HAVE BEEN IN THE LOWER TO MID 40S ACROSS EASTERN SD. THIS AND POSSIBLY EVEN LOWER SHOULD BE REALIZED DURING TUESDAY AFTERNOON WITH PROJECTED MIXING TO 850 MB. THE AFTERNOON HUMIDITY WILL REMAIN LOW...UNDER 25 PERCENT...ON WEDNESDAY AFTERNOON WITH THE SYNOPTIC FLOW TURNING NORTHEAST AND THEN EAST. INFLUENCE FROM THE LAKE WILL LIKELY CONTINUE TO MOVE INTO CHICAGO DURING THE AFTERNOON ALL THE WAY THROUGH SATURDAY. THE UPPER LEVEL HEIGHTS AND LOW-LEVEL THERMAL RIDGE BUILD MORE INTO THE AREA THURSDAY NIGHT INTO SATURDAY. THE EC HAS SHOWN IN THE UPPER LEVEL SW FLOW THAT SHORT WAVE ENERGY IS POSSIBLE WITHIN THIS AND MAY DAMPEN THE RIDGE SLIGHTLY SATURDAY NIGHT INTO SUNDAY...AND HAVE A SMALL CHANCE FOR POPS DURING PART OF THAT TIME. OTHERWISE...HAVE COLLABORATED GOING DRIER THAN POPS AND DEW POINTS FROM GUIDANCE BLENDS IN THE EXTENDED PER PERSISTENCE AND AN OVERALL STAGNANT PATTERN. MTF && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * WINDS SHIFTING FROM SW THIS AFTERNOON TO NW THIS EVENING...POTENTIAL FOR GUSTINESS TO CONTINUE OVERNIGHT. * COUPLE WINDOWS OF POTENTIAL FOR ADDITIONAL THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND AGAIN THIS EVENING. RC //DISCUSSION...UPDATED 20Z... STILL DO NOT THINK TSRA WILL DIRECTLY IMPACT ORD/MDW THE NEXT FEW HOURS AND PROBABILITY OF REDEVELOPMENT AHEAD OF FRONT THIS EVENING IS LOW. VCTS NEAR GYY SHOULD REMAIN SOUTHEAST OF GYY. WILL MONITOR POTENTIAL FOR POP-UP DEVELOPMENT THE NEXT FEW HOURS. OTHER CHANGE IN 20Z AMD WAS TO MOVE UP TIMING OF WIND SHIFT TO NORTHWEST BY 1 HOUR EARLIER AT TAF SITES. THIS MAY NEED TO BE MOVED UP A BIT MORE. POTENTIAL FOR NW WIND GUSTS AFTER FRONTAL PASSAGE EXISTS...BUT NOT ENOUGH CONFIDENCE TO INCLUDE IN TAF. RC ...FROM 18Z... A COLD FRONT LIES ACROSS NORTHWEST WISCONSIN SOUTH INTO CENTRAL IOWA THIS AFTERNOON. ONGOING THUNDERSTORMS CONTINUE ACROSS PORTIONS SOUTHERN MISSOURI INTO CENTRAL ILLINOIS PROVIDING A CANOPY OF CLOUD COVER ACROSS MUCH OF NORTHERN ILLINOIS THIS AFTERNOON. THERE IS SOME CLEARING ACROSS PORTIONS OF EAST CENTRAL ILLINOIS AND NORTHWEST INDIANA WHERE AN AXIS OF MODEST INSTABILITY HAS BEGUN TO DEVELOP. AN UPPER LEVEL DISTURBANCE MOVING ACROSS IOWA EARLY THIS AFTERNOON WILL PUSH EAST ACROSS NORTHERN ILLINOIS WITH THE POTENTIAL FOR ADDITIONAL THUNDERSTORM DEVELOPMENT ACROSS THIS INSTABILITY AXIS MID AFTERNOON. IT APPEARS THE THREAT SHOULD STAY SOUTHEAST/EAST OF ORD/MDW WITH SOME POTENTIAL FOR GYY TO BE IMPACTED OR AT LEAST TO SEE ACTIVITY IN THE VICINITY OF THE TERMINAL. MOVED UP VCTS AT GYY TO START OF TAF GIVEN ACTIVITY CURRENTLY IN THE AREA JUST NORTHWEST OF THE TERMINAL AT 18Z. LATE THIS EVENING...THE COLD FRONT IS EXPECTED TO MOVE ACROSS THE AREA WITH WINDS BECOMING NORTHWEST. THERE MAY BE ADDITIONAL THUNDERSTORMS THAT DEVELOP ALONG THE FRONT...BUT GIVEN THE WEAK CONVERGENCE ALONG THE FRONT AND LOSS OF DIURNAL HEATING...EXPECT COVERAGE TO BE ISOLATED TO WIDELY SCATTERED WITH LOW THREAT OF BEING ON STATION. ON TUESDAY...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE NORTHWEST. WILL HAVE TO MONITOR THE POSSIBILITY OF A LAKE BREEZE TURNING WINDS NORTHEAST IN THE CHICAGO AREA LATE IN THE AFTERNOON. BMD/RC //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM TO HIGH CONFIDENCE IN WIND DIRECTION...LOW CONFIDENCE IN WIND GUST MAGNITUDE...PARTICULARLY THIS EVENING BEHIND THE FRONT. * MEDIUM CONFIDENCE IN TSRA SE OF THE TERMINALS THIS AFTERNOON...LOW CONFIDENCE IT WILL IMPACT ORD/MDW. * LOW CONFIDENCE IN TSRA ALONG THE FRONT THIS EVENING. RC //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH SATURDAY...VFR. SUNDAY...VFR. SLIGHT CHC SHRA/TSRA. BEACHLER && .MARINE... 231 PM CDT A LARGE LOW HAS MOVED INTO HUDSON BAY...WHILE HIGH PRESSURE SITS OFF THE NEW ENGLAND COAST. THE UPPER LEVEL PRESSURE GRADIENT HAS RELAXED...RESULTING IN SOUTH TO SOUTHWEST WINDS 15-25 KT ACROSS THE LAKE THIS AFTERNOON. STRONGEST WINDS AROUND 25 KT WILL CONTINUE TO BE OVER THE NORTHERN HALF OF THE LAKE WHICH IS CLOSER TO THE LOW AND ITS TIGHT PRESSURE GRADIENT. THE LOWS COLD FRONT WILL SWEEP ACROSS THE LAKE TONIGHT. WINDS WILL TURN OUT OF THE WEST AT 15 TO 25 KT ACROSS THE LAKE BEHIND THE FRONT. HIGH PRESSURE MOVES IN BEHIND THE FRONT TUESDAY NIGHT...WITH WINDS DIMINISHING AND BECOMING NORTHERLY FOR A ON TUESDAY. THE LIGHT WINDS WILL CONTINUE TO VEER TO EASTERLY AS THE HIGH MOVES OVER THE LAKE WEDNESDAY. WINDS TURN SOUTHEASTERLY AS THE HIGH MAKES ITS WAY OVER NORTHERN QUEBEC ON THURSDAY. ALTHOUGH THE CENTER OF THE HIGH MOVES OFF TO THE NORTHEAST...A LARGE RIDGE WILL REMAIN OVER THE EASTERN THIRD OF THE US THROUGH THE REMAINING PART OF THE FORECAST PERIOD. THIS PATTERN WILL RESULT IN LIGHT WINDS VARYING BETWEEN EAST AND SOUTH. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
258 PM CDT MON JUN 11 2012 .DISCUSSION... ISSUED 258 PM CDT MON JUN 11 2012 SHORT TERM...TONIGHT THROUGH THURSDAY MAIN QUESTION IN THE IMMEDIATE SHORT-TERM IS WHETHER OR NOT ANY CONVECTION WILL RE-DEVELOP ALONG AN ADVANCING COLD FRONT THIS EVENING. 2 PM SURFACE ANALYSIS SHOWS FRONT ACROSS EASTERN IOWA...HOWEVER AIRMASS AHEAD OF IT IS STILL QUITE STABLE DUE TO MORNING CONVECTION THAT DECAYED ACROSS WEST-CENTRAL ILLINOIS. LATEST MESO-ANALYSIS FROM SPC IS INDICATING SOME DESTABILIZATION ALONG THE BOUNDARY...WITH SURFACE-BASED CAPES BACK UP TO AROUND 1500 TO 2000J/KG. 19Z VISIBLE SATELLITE IMAGERY IS SHOWING A NARROW RIBBON OF CU DEVELOPING IN THE INSTABILITY AXIS...HOWEVER NO SHOWERS/STORMS HAVE FIRED YET. 12Z MODELS ARE LARGELY USELESS...AS NONE OF THEM ADEQUATELY PREDICTED THE STORMS THAT ROLLED ACROSS SOUTH-CENTRAL AND SOUTHEAST ILLINOIS THIS AFTERNOON ALONG THE LEADING EDGE OF AN OLD OUTFLOW BOUNDARY. EVEN SOME OF THE HIGHER-RES MODELS SUCH AS THE 4KM WRF FAILED TO CAPTURE THIS CONVECTION...SO THEIR SOLUTIONS FOR LATE THIS AFTERNOON AND EVENING ARE SUSPECT. THE 17Z HRRR SEEMS TO HAVE THE BEST HANDLE ON REALITY...SHOWING THE CURRENT CONVECTION ACROSS THE FAR E/SE KILX CWA EXITING THE AREA OVER THE NEXT 2 TO 3 HOURS...FOLLOWED BY LARGELY DRY CONDITIONS THIS EVENING. THE HRRR DOES TRY TO DEVELOP SOME ISOLATED CONVECTION ALONG THE COLD FRONT AS IT PUSHES INTO THE ILLINOIS RIVER VALLEY AROUND 00Z...BUT THIS RAPIDLY DISSIPATES AS DAYTIME INSTABILITY IS LOST AFTER SUNSET. SINCE THE FRONT IS STILL OFF TO THE WEST...THINK THIS SOLUTION SEEMS REASONABLE...SO WILL MENTION ISOLATED THUNDER ACROSS THE BOARD DURING THE EARLY EVENING. AFTER THAT...SKIES WILL CLEAR FROM WEST TO EAST ACROSS THE AREA AS THE FRONT PUSHES INTO INDIANA AFTER MIDNIGHT. HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES FOR THE MIDDLE OF THE WEEK...PROVIDING COOLER AND LESS HUMID CONDITIONS FOR TUESDAY THROUGH THURSDAY. COOLEST MORNING WILL BE WEDNESDAY MORNING...WHEN TEMPS FALL INTO THE LOWER 50S. AFTERNOON HIGHS ON WEDNESDAY WILL BE NEAR OR SLIGHTLY BELOW NORMAL IN THE UPPER 70S/LOWER 80S. LONG TERM...FRIDAY THROUGH MONDAY WARMER AND MORE HUMID WEATHER WILL RETURN FOR THE EXTENDED...AS UPPER TROUGH DIGS ACROSS THE WESTERN CONUS AND RIDGING DEVELOPS ACROSS THE EAST. MODELS CONTINUE TO DISAGREE ON THE EXACT DEGREE OF AMPLIFICATION WITHIN THE FLOW...WITH THE 12Z 11 JUN GFS FEATURING A STRONG RIDGE AND RESULTING DRY CONDITIONS RIGHT THROUGH EARLY NEXT WEEK. MEANWHILE...THE LATEST ECMWF CONTINUES TO BE WEAKER WITH THE UPPER RIDGE AND BRINGS A FRONTAL BOUNDARY INTO THE AREA SUNDAY INTO MONDAY. GIVEN CURRENT MODEL DISCREPANCIES AND THE FACT THAT PARTS OF CENTRAL ILLINOIS ARE IN A MODERATE DROUGHT...WILL MAINTAIN HOT AND DRY CONDITIONS THROUGH MONDAY. BARNES && .AVIATION... ISSUED 1255 PM CDT MON JUN 11 2012 LINE OF STRONG THUNDERSTORMS ALONG I-57 ON LEADING EDGE OF MCS AT CMI JUST GOT A NW WIND GUST OF 35 KTS WITH HEAVY RAINS TO REDUCE VSBY TO 1/2-1 MILE DURING THE NEXT HOUR OR SO AS LINE MOVES STEADILY EASTWARD. MVFR CEILINGS LIKELY AS WELL AT CMI. NO REPORTS OF HAIL YET AND THINK BETTER HAIL THREAT WILL BE SOUTH OF CMI. HAVE TS WITH MVFR CEILINGS AND VSBY AT DEC NEXT HOUR WHILE CONVECTION APPEARS TO BE EAST OF I-55/REST OF CENTRAL IL TAF SITES THIS AFTERNOON. COULD STILL BE ISOLATED CONVECTION THIS AFTERNOON AS COLD FRONT IN SE IA INTO CENTRAL MO TRACKS SE INTO SE IL EARLY THIS EVENING. SKIES TO CLEAR LATER THIS EVENING AND CONTINUE THROUGH TUE AS 1026 MB HIGH PRESSURE OVER THE NORTHERN ROCKIES SETTLES INTO THE MIDWEST BY 18Z/TUE. SSW WINDS 10-15 KTS WITH POSSIBLE WIND GUSTS NEAR 20 KTS TO TURN NW BEHIND THE FRONT AND DIMINISH TO 5-10 KTS THEN BE NW 10-15 KTS TUESDAY WITH GUSTS TO 20 KTS BY MIDDAY TUE. HUETTL && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
301 AM CDT MON JUN 11 2012 .DISCUSSION... 929 PM CDT SOME MINOR CHANGES MADE TO ARRIVAL TIMING OF POPS FOR MONDAY MORNING...OTHERWISE NO REAL CHANGES MADE TO GOING FORECAST FOR TONIGHT INTO MONDAY. EXPANSIVE UPPER LEVEL LOW AND ASSOCIATED HIGH PWAT AIR...AS SEEN ON WATER VAPOR...IS EXPANDING NORTHWARD. A WEAK UPPER LEVEL WAVE IN SOUTHWEST IL THIS EVE HAS HELPED TO SPREAD THIS NORTH CAUSING AN EXPANSION IN HIGH CLOUDS ACROSS THE AREA...WHICH SHOULD CONTINUE INTO OVERNIGHT. THESE CLOUDS ALONG WITH SOUTHERLY FLOW REMAINING AROUND 10 MPH TONIGHT SHOULD KEEP MINIMUM TEMPERATURES 3 TO 5 DEGREES WARMER THAN LAST NIGHT...WHICH IS RIGHT ON PAR WITH GOING FORECAST. LIGHT RETURNS ON THE KIND RADAR ARE INDICATIVE OF GRADUAL MID-LEVEL ASCENT AND SATURATION OCCURRING AHEAD OF THIS UPPER LOW. SATELLITE TRENDS AND GUIDANCE FORECASTS KEEP ALMOST ALL OF THIS ENTIRELY EAST OF THE AREA LATER TONIGHT INTO MONDAY MORNING. THE FEATURE WHICH WILL HAVE MORE INFLUENCE ON THE AREA IS A WELL- DEFINED UPPER LEVEL TROUGH ACROSS THE CANADIAN/U.S. HIGH PLAINS BORDER. IMPRESSIVE NORTH-TO-SOUTH LINE OF CONVECTION FROM NEAR INTERNATIONAL FALLS TO NORTHEAST KS HAS DEVELOPED JUST AHEAD OF THE SURFACE COOL FRONT WHERE CONVERGENCE WAS MAXIMIZED AND WITHIN A CORRIDOR OF HIGHER THETA-E RETURN. THE FRONT AND CONVECTION AHEAD OF IT WILL EVOLVE EAST INTO OVERNIGHT...LIKELY GRADUALLY TAPERING IN INTENSITY AND AT LEAST SOMEWHAT IN COVERAGE OVERNIGHT ACROSS IA AND NORTHERN MO. A PORTION OF THIS MAY MAKE IT INTO THE WESTERN FORECAST AREA IN THE EARLY MORNING...AND THE HRRR SOLUTION DEPICTS THIS...HOWEVER IT SEEMS TOO GENEROUS ON DEVELOPMENT OVERNIGHT IN THE ABSENCE OF MUCH OF A LOW-LEVEL JET/WAA. THE MID-LEVEL SHORT WAVE AXIS ACROSS EASTERN NE AND KS HELPING TO DRIVE SOME OF THE CONVECTION IS DEPICTED IN MOST GUIDANCE...AND TRACKS ACROSS THE FORECAST AREA DURING THE LATE MORNING AND AFTERNOON. COLLOCATED WITH THIS APPEARS TO BE A PRE-FRONTAL TROUGH...AT LEAST IN THE 925-700MB FLOW...WHICH HELPS IN FOCUSING SOME OF THE CONVERGENCE FIELDS. INSTABILITY VALUES ARE SIMILAR ON THE 11.00 NAM TO THOSE MENTIONED IN PRIOR DISCUSSION...SO SOME SCATTERED CONVECTION REGENERATING IN COVERAGE DURING THE MIDDAY TIME IS FAVORED AT THIS TIME. HAVE ADJUSTED MORNING POPS TO ACCOUNT FOR THIS TYPE OF TIMING/REASONING. AFTERNOON POPS STILL LOOK GOOD. MTF //PREV DISCUSSION... 317 PM CDT FOCUS OF FORECAST IS ON RAIN CHANCES MON AND MON EVE WITH A COLD FRONT MOVING ACROSS THE AREA...AND THEN ON THE VERY LOW...IF ANY...PROBABILITIES FOR RAIN THROUGH THE REST OF THE WORK WEEK AND WELL INTO NEXT WEEKEND. AN UPPER LOW OVER SOUTHERN SASKATCHEWAN AND NORTHEASTERN MT HAS CONTINUED TO BECOME SHEARED/ELONGATED TODAY...SLOWING ITS EASTWARD PROGRESS. AS A RESULT THE ASSOCIATED SURFACE LOW AND ATTENDANT COLD FRONT HAVE ALSO BEEN RELUCTANT TO MOVE EASTWARD WITH ANY VIGOR. MODELS SHOW THE UPPER LOW IS TO ACCELERATE NORTHEASTWARD LATER TODAY AND TONIGHT AS A SHORT WAVE AND JET MAX DIG SSE FROM THE YUKON-NW TERRITORIES BORDER TO SOUTHERN SASKATCHEWAN AND NE MT BY 12Z MON. THIS SHORT WAVE AND SPEED MAX ARE THEN PROGGED TO TURN SOUTHEASTERLY ACROSS THE DAKOTAS AND MN DURING THE DAY MON. WITH THE UPPER TROUGH BECOMING MORE PROGRESSIVE THE COLD FRONT...WHICH IS CURRENTLY LINGERING ACROSS NW AND W CENTRAL MN AND FAR SE SD AND NE NE... WILL ALSO START TO ACCELERATE EASTWARD...REACHING THE MID MS VALLEY BY EARLY MON AFTERNOON AND CONTINUING TO SE WI AND NE IL EARLY MON EVENING. CONVERGENCE ALONG THE COLD FRONT AS IT MOVES ACROSS THE LOCAL FORECAST AREA IS NOT VERY STRONG THOUGH TIMING OF THE FRONTAL PASSAGE DURING OR SOON AFTER PEAK HEATING LEADS TO IT OCCURRING WHEN INSTABILITY WILL BE MAXIMIZED WITH DEW POINTS SLOWLY CREEPING UP INTO THE 60S OVERNIGHT AND MON. HOWEVER...IF 10.12Z RUN OF GFS VERIFIES WITH THE LAYER FROM 2 TO 4K FT AGL SOME 3-4 DEG C WARMER THAN THE NAM SOLUTION DURING THE DAY MON THEN CONVECTIVE DEVELOPMENT AHEAD OF THE COLD FRONT WILL BE INHIBITED BY THE WARMTH ALOFT MAINTAINING A SIGNIFICANT AREA OF CIN AND CAPPING AT LEAST THROUGH 18Z MON. NAM HAS MINIMAL CIN AHEAD OF THE FRONT BUT THE QPF AND MOS POP VALUES ARE FLIPPED FROM WHAT ONE WOULD EXPECT GIVEN THE DIFFERENCES IN THE FORECAST SOUNDINGS. THAT IS...THE GFS IS MORE GENEROUS WITH THE QPF WHILE THE NAM GENERATES SOME SMALL RAINFALL AMOUNTS INTO N CENTRAL IL BOTH ONLY A FEW HUNDREDTHS AT MOST ACROSS THE REST OF THE FA...WITH MOS POPS IN LOWER END OF CHANCE CATEGORY AND GFS AT HIGH END. HAVE LOWERED POPS SLIGHTLY FOR MON THOUGH STILL LEFT AT VERY LOW END OF LIKELY WITH 55-60 PCT ACROSS THE FA. ZONAL FLOW SPREADS EASTWARD ACROSS THE ROCKIES AND GREAT PLAINS BY TUE...AND ACROSS THE MIDWEST AND GREAT LAKES BY WED BRINGING MILDER AND DRY AIR TO THE REGION. MODELS INDICATE A MINOR SHORT WAVE TO TRAVERSE THE DAKOTAS TUE NIGHT AND WED...AND THE UPPER MIDWEST WED NIGHT AND THU. THE SURFACE RIDGE THAT WILL BUILD IN BEHIND THE COLD FRONT IS PROGGED TO STILL HAVE ITS AXIS FROM QUEBEC SW BACK ACROSS THE GREAT LAKES AND TO THE MID MS VALLEY. THIS WOULD PLACE ANY THREAT OF RAIN WITH THIS DISTURBANCE TO THE N OF THE FA. UPPER RIDGING TO PUSH BACK NORTHEASTWARD ACROSS THE MIDWEST AND GREAT LAKES THU AND FRI AS AN UPPER TROUGH DEEPENS OVER FAR WESTERN NOAM. AFTER MAX TEMPS COOL TO THE 70S FOR A COUPLE DAYS AFTER THE COLD FRONTAL PASSAGE THEY CLIMB BACK INTO THE MID AND UPPER 80S FOR FRI AND NEXT WEEKEND WITH THE UPPER RIDGE BUILDING OVERHEAD. AREAS NEAR THE LAKE WILL BE COOLER FROM TUE INTO NEXT WEEKEND AS THE SURFACE HIGH BUILDING INTO THE REGION ALLOWS NNE FLOW TO TURN IN OFF OF THE LAKE TUE AND THEN WITH THE CENTER OF THE ANTICYCLONE MOVING OVER THE CENTRAL GREAT LAKES PROVIDES E TO SE LOW LEVEL FLOW OFF OF THE LAKE FROM WED ON. RIDGING SURFACE AND ALOFT TO KEEP AREA RAIN-FREE TUE THROUGH SAT...WITH ONLY SLIGHT CHANCES IN N CENTRAL IL ON SUN. WITH THE AREA NOT SEEING ANY LET ALONE SIGNIFICANT RAINFALL SINCE THE END OF MAY ANY AREAS THAT DO NOT GET ANY SIGNIFICANT RAIN WITH COLD FRONT WILL SEE MUCH GREATER MOISTURE DEFICITS AS NO ADDITIONAL THREAT OF SIGNIFICANT RAINS UNTIL AT LEAST LATE NEXT WEEKEND OR EARLY NEXT WORK WEEK. TRS && .FIRE WEATHER... 317 PM CDT WINDS AND RH VALUES APPROACHING BUT NOT EXPECTED TO REACH RED FLAG CRITERIA THE REST OF THE AFTERNOON OR EARLY THIS EVENING. TRS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NO IMPACTS THROUGH 12Z. * TSRA POTENTIAL IN THE AFTERNOON HOURS. BEACHLER //DISCUSSION...UPDATED 06Z... LOW LEVEL HIGH PRESSURE HAS PUSHED FURTHER EAST OF THE REGION...ALLOWING A CONTINUED FEED OF SOUTHERLY WINDS OVER NORTHERN IL/NORTHWEST IN AIRFIELDS. A COLD FRONTAL BOUNDARY REMAINS WEST OF THE REGION...HOWEVER WILL CONTINUE TO SLOWLY PUSH EAST THROUGHOUT THE DAY TODAY. FRONTAL PASSAGE IS EXPECTED TO OCCUR DURING THE LATE AFTN/EVE HOURS. THEN WINDS VEER WEST/NORTHWEST DURING THE EVENING AND OVERNIGHT HOURS INTO TUE. THE OTHER CONCERN IS IN REGARDS TO TSRA DEVELOPMENT. GUIDANCE HAS STRUGGLED WITH THE PRECISE TIMING/PLACEMENT/INTENSITY...AND MANY THINGS STILL NEED TO COME TOGETHER. AT THIS TIME THE BEST TIMING IS FOR SHRA/TSRA DEVELOPMENT TO OCCUR DURING THE AFTN/EVE HOURS...THEN PUSH EAST INTO NORTHERN IN. AT THIS TIME GIVEN THE LOW CONFIDENCE HAVE MAINTAINED THE PROB30 GROUP...AND WILL ALLOW FOR FURTHER ADJUSTMENTS AS WE APPROACH THE LATE MORNING HOURS. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 16Z. * MEDIUM CONFIDENCE ON TSRA DEVELOPMENT AFT 16Z. * LOW CONFIDENCE ON COVERAGE OF TSRA. * HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH SATURDAY...VFR. RATZER && .MARINE... 300 AM CDT SURFACE HIGH PRESSURE CENTERED OVER THE SOUTHEAST COASTAL UNITED STATES WILL CONTINUE TO PUSH EAST...WHILE AN UPPER LEVEL TROUGH OF LOW PRESSURE PUSHES EAST ACROSS THE UPPER MIDWEST. ASSOCIATED WITH THE UPPER LEVEL SYSTEM WAS A COUPLE OF SURFACE LOW PRESSURES OVER CENTRAL AND SOUTHWEST ONTARIO. THESE LOW PRESSURE SYSTEMS WILL CONSOLIDATE ALLOWING FOR A TIGHTENING GRADIENT ALONG THE NORTHERN PORTION OF LAKE MICHIGAN FOR THE FIRST HALF OF TODAY...THEN THE GRADIENT WILL BEGIN TO SLACKEN MARGINALLY. SOUTHERLY FLOW WILL DOMINATE THE LAKE FOR TODAY...THEN AS A FRONTAL BOUNDARY SLOWLY APPROACHES FROM THE WEST WINDS WILL BEGIN TO TURN SOUTHWESTERLY. FRONTAL PASSAGE WILL BRING WEST AND EVENTUALLY NORTHWEST WINDS ACROSS THE LAKE. THE LOW PRESSURE SYSTEM OVER SOUTHERN HUDSON BAY WILL THEN DEEPEN...ALLOWING FOR AN INCREASED GRADIENT TO OCCUR ACROSS THE NORTHERN LAKES AND MAY STRETCH SOUTH ACROSS LAKE MICHIGAN TUE. OVERALL EXPECT WINDS TUE FROM A NORTHWEST/NORTH WIND TO BE 15 TO 25 KT. BROAD HIGH PRESSURE THEN BUILDS INTO THE GREAT LAKES REGION AND WILL PROVIDE MUCH LIGHTER WINDS FOR THE TUE NGT THROUGH THUR PERIODS. WINDS WILL MAINLY BE NORTH/NORTHEAST DURING THESE PERIODS. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
101 AM CDT MON JUN 11 2012 .DISCUSSION... 929 PM CDT SOME MINOR CHANGES MADE TO ARRIVAL TIMING OF POPS FOR MONDAY MORNING...OTHERWISE NO REAL CHANGES MADE TO GOING FORECAST FOR TONIGHT INTO MONDAY. EXPANSIVE UPPER LEVEL LOW AND ASSOCIATED HIGH PWAT AIR...AS SEEN ON WATER VAPOR...IS EXPANDING NORTHWARD. A WEAK UPPER LEVEL WAVE IN SOUTHWEST IL THIS EVE HAS HELPED TO SPREAD THIS NORTH CAUSING AN EXPANSION IN HIGH CLOUDS ACROSS THE AREA...WHICH SHOULD CONTINUE INTO OVERNIGHT. THESE CLOUDS ALONG WITH SOUTHERLY FLOW REMAINING AROUND 10 MPH TONIGHT SHOULD KEEP MINIMUM TEMPERATURES 3 TO 5 DEGREES WARMER THAN LAST NIGHT...WHICH IS RIGHT ON PAR WITH GOING FORECAST. LIGHT RETURNS ON THE KIND RADAR ARE INDICATIVE OF GRADUAL MID-LEVEL ASCENT AND SATURATION OCCURRING AHEAD OF THIS UPPER LOW. SATELLITE TRENDS AND GUIDANCE FORECASTS KEEP ALMOST ALL OF THIS ENTIRELY EAST OF THE AREA LATER TONIGHT INTO MONDAY MORNING. THE FEATURE WHICH WILL HAVE MORE INFLUENCE ON THE AREA IS A WELL- DEFINED UPPER LEVEL TROUGH ACROSS THE CANADIAN/U.S. HIGH PLAINS BORDER. IMPRESSIVE NORTH-TO-SOUTH LINE OF CONVECTION FROM NEAR INTERNATIONAL FALLS TO NORTHEAST KS HAS DEVELOPED JUST AHEAD OF THE SURFACE COOL FRONT WHERE CONVERGENCE WAS MAXIMIZED AND WITHIN A CORRIDOR OF HIGHER THETA-E RETURN. THE FRONT AND CONVECTION AHEAD OF IT WILL EVOLVE EAST INTO OVERNIGHT...LIKELY GRADUALLY TAPERING IN INTENSITY AND AT LEAST SOMEWHAT IN COVERAGE OVERNIGHT ACROSS IA AND NORTHERN MO. A PORTION OF THIS MAY MAKE IT INTO THE WESTERN FORECAST AREA IN THE EARLY MORNING...AND THE HRRR SOLUTION DEPICTS THIS...HOWEVER IT SEEMS TOO GENEROUS ON DEVELOPMENT OVERNIGHT IN THE ABSENCE OF MUCH OF A LOW-LEVEL JET/WAA. THE MID-LEVEL SHORT WAVE AXIS ACROSS EASTERN NE AND KS HELPING TO DRIVE SOME OF THE CONVECTION IS DEPICTED IN MOST GUIDANCE...AND TRACKS ACROSS THE FORECAST AREA DURING THE LATE MORNING AND AFTERNOON. COLLOCATED WITH THIS APPEARS TO BE A PRE-FRONTAL TROUGH...AT LEAST IN THE 925-700MB FLOW...WHICH HELPS IN FOCUSING SOME OF THE CONVERGENCE FIELDS. INSTABILITY VALUES ARE SIMILAR ON THE 11.00 NAM TO THOSE MENTIONED IN PRIOR DISCUSSION...SO SOME SCATTERED CONVECTION REGENERATING IN COVERAGE DURING THE MIDDAY TIME IS FAVORED AT THIS TIME. HAVE ADJUSTED MORNING POPS TO ACCOUNT FOR THIS TYPE OF TIMING/REASONING. AFTERNOON POPS STILL LOOK GOOD. MTF //PREV DISCUSSION... 317 PM CDT FOCUS OF FORECAST IS ON RAIN CHANCES MON AND MON EVE WITH A COLD FRONT MOVING ACROSS THE AREA...AND THEN ON THE VERY LOW...IF ANY...PROBABILITIES FOR RAIN THROUGH THE REST OF THE WORK WEEK AND WELL INTO NEXT WEEKEND. AN UPPER LOW OVER SOUTHERN SASKATCHEWAN AND NORTHEASTERN MT HAS CONTINUED TO BECOME SHEARED/ELONGATED TODAY...SLOWING ITS EASTWARD PROGRESS. AS A RESULT THE ASSOCIATED SURFACE LOW AND ATTENDANT COLD FRONT HAVE ALSO BEEN RELUCTANT TO MOVE EASTWARD WITH ANY VIGOR. MODELS SHOW THE UPPER LOW IS TO ACCELERATE NORTHEASTWARD LATER TODAY AND TONIGHT AS A SHORT WAVE AND JET MAX DIG SSE FROM THE YUKON-NW TERRITORIES BORDER TO SOUTHERN SASKATCHEWAN AND NE MT BY 12Z MON. THIS SHORT WAVE AND SPEED MAX ARE THEN PROGGED TO TURN SOUTHEASTERLY ACROSS THE DAKOTAS AND MN DURING THE DAY MON. WITH THE UPPER TROUGH BECOMING MORE PROGRESSIVE THE COLD FRONT...WHICH IS CURRENTLY LINGERING ACROSS NW AND W CENTRAL MN AND FAR SE SD AND NE NE... WILL ALSO START TO ACCELERATE EASTWARD...REACHING THE MID MS VALLEY BY EARLY MON AFTERNOON AND CONTINUING TO SE WI AND NE IL EARLY MON EVENING. CONVERGENCE ALONG THE COLD FRONT AS IT MOVES ACROSS THE LOCAL FORECAST AREA IS NOT VERY STRONG THOUGH TIMING OF THE FRONTAL PASSAGE DURING OR SOON AFTER PEAK HEATING LEADS TO IT OCCURRING WHEN INSTABILITY WILL BE MAXIMIZED WITH DEW POINTS SLOWLY CREEPING UP INTO THE 60S OVERNIGHT AND MON. HOWEVER...IF 10.12Z RUN OF GFS VERIFIES WITH THE LAYER FROM 2 TO 4K FT AGL SOME 3-4 DEG C WARMER THAN THE NAM SOLUTION DURING THE DAY MON THEN CONVECTIVE DEVELOPMENT AHEAD OF THE COLD FRONT WILL BE INHIBITED BY THE WARMTH ALOFT MAINTAINING A SIGNIFICANT AREA OF CIN AND CAPPING AT LEAST THROUGH 18Z MON. NAM HAS MINIMAL CIN AHEAD OF THE FRONT BUT THE QPF AND MOS POP VALUES ARE FLIPPED FROM WHAT ONE WOULD EXPECT GIVEN THE DIFFERENCES IN THE FORECAST SOUNDINGS. THAT IS...THE GFS IS MORE GENEROUS WITH THE QPF WHILE THE NAM GENERATES SOME SMALL RAINFALL AMOUNTS INTO N CENTRAL IL BOTH ONLY A FEW HUNDREDTHS AT MOST ACROSS THE REST OF THE FA...WITH MOS POPS IN LOWER END OF CHANCE CATEGORY AND GFS AT HIGH END. HAVE LOWERED POPS SLIGHTLY FOR MON THOUGH STILL LEFT AT VERY LOW END OF LIKELY WITH 55-60 PCT ACROSS THE FA. ZONAL FLOW SPREADS EASTWARD ACROSS THE ROCKIES AND GREAT PLAINS BY TUE...AND ACROSS THE MIDWEST AND GREAT LAKES BY WED BRINGING MILDER AND DRY AIR TO THE REGION. MODELS INDICATE A MINOR SHORT WAVE TO TRAVERSE THE DAKOTAS TUE NIGHT AND WED...AND THE UPPER MIDWEST WED NIGHT AND THU. THE SURFACE RIDGE THAT WILL BUILD IN BEHIND THE COLD FRONT IS PROGGED TO STILL HAVE ITS AXIS FROM QUEBEC SW BACK ACROSS THE GREAT LAKES AND TO THE MID MS VALLEY. THIS WOULD PLACE ANY THREAT OF RAIN WITH THIS DISTURBANCE TO THE N OF THE FA. UPPER RIDGING TO PUSH BACK NORTHEASTWARD ACROSS THE MIDWEST AND GREAT LAKES THU AND FRI AS AN UPPER TROUGH DEEPENS OVER FAR WESTERN NOAM. AFTER MAX TEMPS COOL TO THE 70S FOR A COUPLE DAYS AFTER THE COLD FRONTAL PASSAGE THEY CLIMB BACK INTO THE MID AND UPPER 80S FOR FRI AND NEXT WEEKEND WITH THE UPPER RIDGE BUILDING OVERHEAD. AREAS NEAR THE LAKE WILL BE COOLER FROM TUE INTO NEXT WEEKEND AS THE SURFACE HIGH BUILDING INTO THE REGION ALLOWS NNE FLOW TO TURN IN OFF OF THE LAKE TUE AND THEN WITH THE CENTER OF THE ANTICYCLONE MOVING OVER THE CENTRAL GREAT LAKES PROVIDES E TO SE LOW LEVEL FLOW OFF OF THE LAKE FROM WED ON. RIDGING SURFACE AND ALOFT TO KEEP AREA RAIN-FREE TUE THROUGH SAT...WITH ONLY SLIGHT CHANCES IN N CENTRAL IL ON SUN. WITH THE AREA NOT SEEING ANY LET ALONE SIGNIFICANT RAINFALL SINCE THE END OF MAY ANY AREAS THAT DO NOT GET ANY SIGNIFICANT RAIN WITH COLD FRONT WILL SEE MUCH GREATER MOISTURE DEFICITS AS NO ADDITIONAL THREAT OF SIGNIFICANT RAINS UNTIL AT LEAST LATE NEXT WEEKEND OR EARLY NEXT WORK WEEK. TRS && .FIRE WEATHER... 317 PM CDT WINDS AND RH VALUES APPROACHING BUT NOT EXPECTED TO REACH RED FLAG CRITERIA THE REST OF THE AFTERNOON OR EARLY THIS EVENING. TRS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * NO IMPACTS THROUGH 12Z. * TSRA POTENTIAL IN THE AFTERNOON HOURS. BEACHLER //DISCUSSION...UPDATED 06Z... LOW LEVEL HIGH PRESSURE HAS PUSHED FURTHER EAST OF THE REGION...ALLOWING A CONTINUED FEED OF SOUTHERLY WINDS OVER NORTHERN IL/NORTHWEST IN AIRFIELDS. A COLD FRONTAL BOUNDARY REMAINS WEST OF THE REGION...HOWEVER WILL CONTINUE TO SLOWLY PUSH EAST THROUGHOUT THE DAY TODAY. FRONTAL PASSAGE IS EXPECTED TO OCCUR DURING THE LATE AFTN/EVE HOURS. THEN WINDS VEER WEST/NORTHWEST DURING THE EVENING AND OVERNIGHT HOURS INTO TUE. THE OTHER CONCERN IS IN REGARDS TO TSRA DEVELOPMENT. GUIDANCE HAS STRUGGLED WITH THE PRECISE TIMING/PLACEMENT/INTENSITY...AND MANY THINGS STILL NEED TO COME TOGETHER. AT THIS TIME THE BEST TIMING IS FOR SHRA/TSRA DEVELOPMENT TO OCCUR DURING THE AFTN/EVE HOURS...THEN PUSH EAST INTO NORTHERN IN. AT THIS TIME GIVEN THE LOW CONFIDENCE HAVE MAINTAINED THE PROB30 GROUP...AND WILL ALLOW FOR FURTHER ADJUSTMENTS AS WE APPROACH THE LATE MORNING HOURS. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN ALL ELEMENTS THROUGH 16Z. * MEDIUM CONFIDENCE ON TSRA DEVELOPMENT AFT 16Z. * LOW CONFIDENCE ON COVERAGE OF TSRA. * HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z... TUESDAY THROUGH SATURDAY...VFR. RATZER && .MARINE... 202 PM...SOUTHERLY FLOW WILL CONTINUE THROUGH MONDAY AFTERNOON UNTIL A COLD FRONT MOVES ACROSS LAKE MICHIGAN MONDAY EVENING. A LARGE AREA OF LOW PRESSURE OVER SOUTHERN CANADA WILL EVENTUALLY CONSOLIDATE INTO ONE LOW AND SLOWLY LIFT NORTHEAST TO HUDSON BAY MONDAY. THE GRADIENT IS STILL EXPECTED TO TIGHTEN SOME... ESPECIALLY OVER THE NORTHERN PORTION OF THE LAKE WHERE 15-25KTS IS POSSIBLE. WINDS WILL SLOWLY DIMINISH AHEAD OF THE FRONT AND THEN SHIFT NORTHWEST BEHIND THE FRONT MONDAY EVENING INTO MONDAY NIGHT. HIGH PRESSURE BUILDS ACROSS THE PLAINS TUESDAY...MAINTAINING A NORTHWESTERLY FLOW ACROSS THE LAKE AND AS THE HIGH SPREADS EAST IN THE AFTERNOON...EXPECT THE GRADIENT TO WEAKEN ENOUGH FOR A LAKE BREEZE TO FORM ACROSS NORTHEAST IL AND NORTHWEST INDIANA. THE HIGH WILL MOVE ACROSS THE LAKES REGION TUESDAY NIGHT INTO WEDNESDAY WITH LIGHT WINDS BECOMING SOUTHERLY THURSDAY AS THE HIGH DEPARTS. CMS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1109 PM CDT SUN JUN 10 2012 .DISCUSSION... ISSUED 852 PM CDT SUN JUN 10 2012 LATEST SURFACE ANALYSIS INDICATES THE COLD FRONT WHICH WILL AFFECT OUR AREA ON MONDAY WAS LOCATED OVER EXTREME WESTERN IOWA EARLY THIS EVENING. CONVECTION HAS BEEN ORGANIZING ALONG AND JUST TO THE EAST OF THE FRONT OVER THE PAST SEVERAL HOURS AND SEEMS TO BE GETTING BETTER ORGANIZED...ESPECIALLY ACRS SOUTHWEST IOWA INTO SE NEBRASKA WHERE THE CONVERGENCE WAS MOST PRONOUNCED OVER THE PAST SEVERAL HOURS. SHORT TERM MODELS CONTINUE TO SUGGEST THE CONVECTION WILL PUSH EAST AND SOUTHEAST THRU IOWA AND INTO NORTHERN MISSOURI LATE THIS EVENING AND INTO THE EARLY MORNING HOURS WITH A GRADUAL WEAKENING TREND AS IT TRACKS TO EXTREME EASTERN IOWA AND NE MISSOURI TOWARDS 300 AM...AND POSSIBLY INTO PARTS OF WEST CENTRAL IL JUST BEFORE DAWN. THE 00Z ILX AND SGF SOUNDINGS SHOWING A FAIRLY STRONG CAP IN PLACE EARLY THIS EVENING WITH OUR AREAS IN BETWEEN THE BETTER MOISTURE SOURCES...WITH THE DEEP TROPICAL MOISTURE ASSOCIATED WITH THE SOUTHERN MISSISSIPPI VALLEY UPPER WAVE MAINLY ACRS THE EAST AND SE SECTIONS OF OUR FORECAST AREA...AND THE BETTER LOW LEVEL MOISTURE AHEAD OF THE FRONT LOCATED IN A NARROW SW-NE CORRIDOR JUST AHEAD OF THE COLD FRONT. THE BETTER INSTABILITY FROM THE SPC MESOANALYSIS WAS LOCATED ACROSS PARTS OF SOUTHWEST IOWA INTO EASTERN KS AND NW MO WHERE SURFACE BASE CAPES WERE IN THE 2500 TO 3000 J/JG OVER THE PAST HOUR WITH THE ELEVATED MIXED LAYER STARTING TO ERODE THANKS TO THE INCREASING SFC MOISTURE CONVERGENCE AND JET DYNAMICS. PROPAGATION VECTORS SUGGEST THE MORE ORGANIZED CONVECTION MAY START TO TURN SE INTO PARTS OF NW MO AND NE KS EARLY THIS EVENING AS THE NORTHERN PORTION OF THE CONVECTION WEAKENS SOME AS IT TRACKS FURTHER EAST. THIS TYPE OF SCENARIO DOES NOT BODE WELL WITH RESPECT TO SEEING SOME DECENT RAINFALL ACRS OUR AREA ON MONDAY. WHAT IS LEFT OF THE CONVECTION WILL PUSH ACRS WESTERN IL DURING THE MORNING AND POSSIBLY REDEVELOP ALONG OR EAST OF THE I-55 CORRIDOR DURING THE AFTERNOON AS THE COLD FRONT APPROACHES THE AREA. UPPER LEVEL SUPPORT AS WELL AS ANY LOW LEVEL CONVERGENCE DOES NOT LOOK THAT GREAT FOR ANY SIGNIFICANT ORGANIZATION TO THE CONVECTION TOMORROW AHEAD OF THE COLD FRONT...DESPITE THE MODERATE INSTABILITY SEEN ON MODELS...NEVER THE LESS...WE SHOULD SEE AT LEAST SOME SCATTERED SHOWERS AND THUNDERSTORMS ACRS THE AREA DURING THE DAY BUT THIS CERTAINLY DOESN`T LOOK LIKE IT WILL PRODUCE WIDESPREAD RAINFALL...WHICH WE DESPERATELY NEED. THE CURRENT ZONE FORECAST IS IN GOOD SHAPE THIS EVENING...SO OTHER THAN THE USUAL EARLY EVENING TWEAKS TO THE HOURLY TEMPERATURE GRIDS...NO OTHER ADJUSTMENTS WILL BE NEEDED...AS A RESULT NO ZONE UPDATE WILL BE NEEDED. && .AVIATION... ISSUED 1105 PM CDT SUN JUN 10 2012 LOOKING AT MAINLY VFR CONDITIONS THRU THIS FORECAST PERIOD. STILL SOME QUESTIONS WITH RESPECT TO TIMING OF CONVECTION...OR WHAT IS LEFT OF THE CONVECTION CURRENTLY GOING ACRS CENTRAL IOWA AND ANY AFFECT ON CIGS ACRS OUR AREA TOMORROW MORNING. TIMING OF PRECIP STILL LOOKS TO BE IN THE 10Z-14Z TIME FRAME ACRS THE WEST BEFORE DISSIPATING. MAY SEE SOME RE-DEVELOPMENT ALONG OR JUST EAST OF I-55 BETWEEN 18Z-22Z WITH COVERAGE STILL LIMITED ENOUGH TO CONTINUE WITH VCTS. ANY CONVECTION THAT DOES FORM LATE TOMORROW MORNING OR EARLY AFTN SHOULD PUSH EAST OF THE TAF SITES BY 00Z WITH THE ACTUAL COLD FRONT LAGGING SEVERAL HOURS BEHIND THE PRECIP. SURFACE WINDS WILL CONTINUE FROM A SE DIRECTION OVERNIGHT AT 5 TO 10 KTS...AND THEN WINDS WILL BEGIN TO VEER MORE INTO THE SOUTHWEST TOMORROW WITH SPEEDS RUNNING FROM 10 TO 15 KTS. THE WIND WILL SHIFT INTO THE WEST LATE TOMORROW AFTN AND EVENING AS THE FRONT EDGES ACRS THE FORECAST AREA. SMITH && .PREV DISCUSSION... ISSUED 257 PM CDT SUN JUN 10 2012 SHORT TERM...TONIGHT THROUGH WEDNESDAY UPPER-LEVEL DISTURBANCE CURRENTLY OVER THE LOWER MISSISSIPPI RIVER VALLEY WILL CONTINUE TO SPREAD MOISTURE NORTHWARD INTO THE REGION TONIGHT. LATEST SATELLITE/RADAR LOOPS INDICATE THE DEEPER MOISTURE AND ASSOCIATED PRECIP ARE PRIMARILY LIMITED TO LOCATIONS ALONG AND TO THE RIGHT OF THIS FEATURE. AS A RESULT...THE BEST RAIN CHANCES WILL SPREAD INTO THE TENNESSEE AND OHIO RIVER VALLEYS TONIGHT...GENERALLY STAYING EAST OF ILLINOIS. HIGH-RES MODELS SUCH AS THE HRRR ARE KEEPING THE KILX CWA DRY...HOWEVER WITH DEEPER MOISTURE COMING SO CLOSE TO THE E/SE...HAVE OPTED TO MAINTAIN A SLIM CHANCE FOR SHOWERS ALONG/EAST OF I-57 TONIGHT. MEANWHILE...VIGOROUS UPPER WAVE OVER THE NORTHERN ROCKIES WILL TRACK ALONG THE CANADIAN BORDER TOWARD THE NORTHERN GREAT LAKES BY MONDAY EVENING. TRAILING COLD FRONT WILL CROSS THE MISSISSIPPI RIVER BY AROUND MIDDAY MONDAY AND BE LOCATED ALONG THE I-55 CORRIDOR BY EARLY MONDAY EVENING. AIRMASS AHEAD OF THE FRONT WILL BECOME MODERATELY UNSTABLE...CHARACTERIZED BY CAPE VALUES OF 1500 TO 2500J/KG. MITIGATING FACTOR FOR WIDESPREAD THUNDERSTORMS AND SEVERE POTENTIAL WILL BE LACK OF WIND SHEAR. FORECAST SOUNDINGS INDICATE WEAK WIND PROFILE THROUGHOUT THE ENTIRE DEPTH OF THE ATMOSPHERE AND VERY WEAK 0-6 KM BULK SHEAR VALUES OF 15 TO 25KT. DESPITE LACK OF SHEAR...ADEQUATE INSTABILITY AND GOOD CONVERGENCE ALONG THE ADVANCING FRONT WILL RESULT IN A BROKEN LINE OF STORMS...WITH A LOW PROBABILITY FOR SEVERE. PRIMARY TIME FRAME WILL BE DURING THE LATE MORNING/AFTERNOON WEST OF I-55...AND DURING THE EVENING FURTHER EAST. ANY CONVECTION WILL QUICKLY EXIT INTO INDIANA AFTER MIDNIGHT...WITH CLEARING SKIES NOTED FROM WEST TO EAST ACROSS THE AREA TOWARD DAWN. HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES BEHIND THE DEPARTING COLD FRONT ON TUESDAY AND WEDNESDAY...BRINGING A COOLER/DRIER AIRMASS INTO THE REGION. WITH 850MB TEMPS PROGGED TO DROP INTO THE 12 TO 14C RANGE...HIGHS WILL FALL BACK TO NEAR NORMAL FOR THIS TIME OF YEAR IN THE UPPER 70S/LOWER 80S. LONG TERM...THURSDAY THROUGH SUNDAY MODELS CONTINUE TO ADVERTISE UPPER TROUGHING DEVELOPING ACROSS THE WESTERN CONUS BY THE END OF THE WEEK...RESULTING IN DOWNSTREAM RIDGING AND WARMER WEATHER FOR THE MIDWEST. EXACT EVOLUTION AND DEGREE OF AMPLIFICATION STILL REMAIN IN QUESTION...WITH A SLIGHTLY DIFFERENT SOLUTION FEATURED ON EACH SUCCESSIVE MODEL RUN. GIVEN UNCERTAINTIES...HAVE OPTED TO MAINTAIN A DRY FORECAST THROUGH NEXT WEEKEND EVEN THOUGH THE ECMWF SUGGESTS A FRONT MAY APPROACH FROM THE NORTHWEST BY SUNDAY. 12Z 10 JUN GFS IS MUCH STRONGER WITH THE EASTERN RIDGE AND DEVELOPS A REX BLOCK ACROSS THE GREAT LAKES/OHIO RIVER VALLEY. IF THIS SOLUTION PANS OUT...THE NEXT CHANCE FOR RAIN WOULD BE DELAYED PERHAPS UNTIL THE MIDDLE OF NEXT WEEK. WILL THEREFORE MAINTAIN WARM/DRY CONDITIONS THROUGH SUNDAY...UNTIL BETTER MODEL CONSISTENCY IS ACHIEVED. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1230 AM EDT MON JUN 11 2012 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 308 PM EDT SUN JUN 10 2012 AN UPPER SYSTEM WILL MOVE SOUTHEAST OF THE AREA ON MONDAY BRINGING SOME RAIN TO THE AREA...THEN A COLD FRONT WILL MOVE THROUGH ON MONDAY NIGHT BRINGING ADDITIONAL CHANCES FOR RAIN. HIGH PRESSURE WILL THEN BUILD IN AND DRY WEATHER INTO NEXT WEEKEND. && .NEAR TERM /OVERNIGHT/... ISSUED AT 940 PM EDT SUN JUN 10 2012 MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH THE UPPER LEVEL DISTURBANCE OVER THE TENNESSEE VALLEY CONTINUING TO SPREAD INTO THE REGION THIS EVENING. HAVE SEEN A FEW SPRINKLES/VERY LIGHT RAIN SHOWERS MOVING NORTH THROUGH SOUTHERN FORECAST AREA. TEMPS WERE IN THE UPPER 70S AND LOWER 80S AT 01Z. NOT MUCH CHANGE TO CURRENT FORECAST FOR THE OVERNIGHT. ONLY EXCEPTION WILL BE TO MAKE SOME REFINEMENTS TO POPS BASED ON RADAR AND SATELLITE TRENDS AND SUPPORTED BY MOST RECENT SHORT RANGE MODEL GUIDANCE. GREATER COVERAGE TO RAINFALL ASSOCIATED WITH THE UPPER DISTURBANCE FROM MIDDLE TENNESSEE SOUTH INTO ALABAMA/GEORGIA CURRENTLY. RAP APPEARS TO CAPTURE THIS ACTIVITY WELL THIS EVENING...TRACKING IT N/NE OVERNIGHT AND INTO THE OHIO VALLEY TOWARDS DAYBREAK. WILL CONTINUE WITH LIKELY POPS OVER FAR SOUTHEAST COUNTIES WHERE CONFIDENCE IS HIGHEST IN MEASURABLE PRECIP LATE. DROPPED BACK TO LOW CHANCE POPS FURTHER NORTH AND WEST OVER MUCH OF THE REMAINDER OF THE FORECAST AREA. ALSO REMOVED ISOLATED THUNDER FROM ALL BUT FAR SOUTHEAST COUNTIES WITH ONLY WEAK ELEVATED CAPE VALUES PRESENT AND LITTLE IN THE WAY OF LIGHTNING STRIKES WITH PRECIP SHIELD TO OUR SOUTH. ZONE AND GRID UPDATES OUT SHORTLY. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... ISSUED AT 308 PM EDT SUN JUN 10 2012 FOCUS IS ON RAIN CHANCES EARLY IN THE PERIOD. NAM IS A LITTLE STRONGER THAN THE OTHER MODELS AND STANDS OUT...SO WENT CLOSER TO GFS/ECMWF. UPPER SYSTEM TO OUR EAST WILL STILL BE CLOSE ENOUGH FOR LOW END LIKELY POPS MONDAY MORNING ACROSS THE EAST AND CHANCE POPS ELSEWHERE. THEN FOR THE AFTERNOON THE FORECAST AREA WILL BE IN BETWEEN THE EASTERN SYSTEM AND A COLD FRONT APPROACHING FROM THE WEST. THUS WENT CHANCE POPS ALL AREAS DURING THE AFTERNOON. THE FRONT WILL MOVE IN MONDAY NIGHT...BUT BY THEN TIMING IS NOT FAVORABLE AS INSTABILITY WILL BE DIMINISHING. THUS AGAIN ONLY WENT CHANCE POPS DURING THE EVENING...DECREASING OVERNIGHT. ONLY KEPT SLIGHT CHANCE POPS IN THE FAR EAST ON TUESDAY TO ACCOUNT FOR ANY LINGERING SHOWERS BEHIND THE FRONT...BUT THIS WILL PROBABLY BE ABLE TO BE REMOVED IF CURRENT MODEL TRENDS CONTINUE. DRY CONDITIONS WILL THEN MOVE IN THROUGH WEDNESDAY AS HIGH PRESSURE MOVES IN. AS FAR AS TEMPERATURES ARE CONCERNED...WENT CLOSER TO THE WARMER MAV ON MONDAY AS NOTED ABOVE MOST OF THE AREA WILL BE IN BETWEEN SYSTEMS DURING THE DAY. STUCK CLOSE TO MODEL BLEND FOR MUCH OF THE REST OF THE PERIOD. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... ISSUED AT 308 PM EDT SUN JUN 10 2012 HIGH PRESSURE OVER THE GREAT LAKES WILL SLOWLY MAKES ITS WAY TOWARDS NEW ENGLAND KEEPING CONDITIONS DRY THROUGHOUT THE PERIOD. THE GFS AND CANADIAN DEPICT A WEAK WAVE AND ASSOCIATED VORT MAX POSSIBLY IMPACTING THE AREA ON SUNDAY. HOWEVER...MODELS CURRENTLY INDICATE PRECIPITATION CHANCES NOT EXPECTED TO IMPACT THE AREA UNTIL SUNDAY NIGHT AT THE EARLIEST. THEREFORE...REMOVED ALLBLEND SLIGHT CHANCE POPS AND CONTINUED WITH AN ENTIRELY DRY FORECAST FOR THE LONG TERM. TEMPERATURES WILL START OUT NEAR NORMAL VALUES AND GRADUALLY INCREASE THROUGHOUT THE PERIOD ALLOWING ABOVE NORMAL VALUES TO RETURN. && .AVIATION /DISCUSSION FOR THE 110600Z TAFS/... ISSUED AT 1230 AM EDT MON JUN 11 2012 EXPECTING CEILINGS TO FALL INTO THE 040-050 RANGE DURING THE PRE DAWN HOURS AS DEEPER MOISTURE CONTINUES TO ADVECT INTO THE AREA. UPPER DISTURBANCE CURRENTLY OVER THE TENNESSEE VALLEY EXPECTED TO DRIFT NORTHEAST INTO THE LOCAL AREA AFTER SUNRISE ON MONDAY. LIFT LOOKS RATHER DISORGANIZED WITH THIS SYSTEM WITH 850MB WINDS GENERALLY WEAK. SOME SCATTERED SHOWER ACTIVITY POSSIBLE AFTER SUNRISE ON MONDAY...ESPECIALLY IN THE VICINITY OF KIND/KBMG...BUT WITH THE DISORGANIZED LIFT...ONLY MVFR VISIBILITY RESTRICTIONS EXPECTED IN ANY SHOWERS. HEATING OF THE MOIST BOUNDARY LAYER MAY RESULT IN SOME AREAS OF MVFR CEILINGS AFTER SUNRISE AS WELL. A BETTER THREAT FOR ORGANIZED CONVECTION MAY DEVELOP OVER THE TAF SITES AFTER ABOUT 112000Z WITH THE APPROACH OF A FRONTAL ZONE/UPPER TROUGH FROM THE WEST. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...50 NEAR TERM...RYAN SHORT TERM...50 LONG TERM....HOMANN/50 AVIATION...JAS/JP
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1214 PM CDT MON JUN 11 2012 ...UPDATE TO AVIATION... .DISCUSSION... STRONG MOISTURE CONVERGENCE CONTINUES IN FAR NORTHEAST KANSAS BEHIND SURFACE FRONT...WHICH LIES FROM ROUGHLY FROM KDSM TO KTOP TO KWLD AT 08Z. GUSTY NORTHEAST WINDS WERE REPORTED AT KMHK AT 08Z WITH OUTFLOW BOUNDARY SHOWING NEAR THE KTWX RADAR. MUCH DRIER AIR NOT FAR BEHIND WITH SURFACE DEWPOINTS IN THE UPPER 40S IN NORTH CENTRAL KANSAS AND LOWER 30S IN NORTHWEST KANSAS. WEAK MID LEVEL RETURNS SHOWING UP ON WESTERN KANSAS RADARS BUT LITTLE NEARING THE SURFACE IN MID LEVEL FRONTOGENESIS. 0Z 850MB TEMPS WERE VERY CLOSE TO 20C THROUGHOUT THE SURROUNDING STATES...THOUGH TEMPS BELOW 10C WERE SAMPLED IN MONTANA. WILL GO ALONG WITH HRRR AND RUC WITH CONVECTION SLOWLY PUSHING SOUTHEAST OUT OF THE AREA THIS MORNING AS THE MODIFIED CONTINENTAL AIRMASS MOVES IN. WESTERN MID LEVEL RETURNS SHOULD ENCOUNTER THIS DRIER AIR AND STILL STRUGGLE TO REACH THE GROUND. COLD AIR ADVECTION TAKES ITS TIME GETTING HERE HOWEVER...WITH SOMEWHAT INCREASED LEVELS COMING LATE IN THE DAY. WITH SOME EARLY DAY HIGH CLOUD AS WELL...THIS MAY KEEP NORTHERN AREAS IN THE MID 80S...WITH SOME UPPER 80S ALONG I-70 WHERE EARLY DAY DEBRIS IS MORE REMOVED AND BETTER CALL WILL HOLD OFF LONGER. TONIGHT INTO TUESDAY PERIODS LOOK RATHER QUIET WITH SURFACE HIGH PASSING ACROSS NEBRASKA AND IOWA AND 700-850MB RIDGING OVER EASTERN KANSAS. MAY SEE SOME HIGH CLOUD MOVE OUT OF THE ROCKIES TUESDAY WITH HIGHS A LITTLE COOLER THAN TODAY. MODELS HAVE BEEN FAIRLY CONSISTENT WITH A WEAK UPPER WAVE MOVING THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. SOUTHERLY LOW/MID LEVEL FLOW WILL SLOWLY INCREASE RESULTING IN WEAK ISENTROPIC LIFT WHILE PRECIPITABLE WATER VALUES RISE TO AROUND 1.3 INCHES BY LATE WEDNESDAY. COMBINED FORCING AND DEEPER MOISTURE MAY BE ENOUGH FOR SOME CONVECTION...THOUGH COVERAGE IS MUCH IN QUESTION AT THIS POINT. WILL KEEP POPS ON THE LOW SIDE WEDNESDAY AND WEDNESDAY NIGHT...KEEPING TUESDAY NIGHT DRY AT THIS POINT. WEAK MID LEVEL LAPSE RATES SHOULD KEEP STRONG INSTABILITY IN CHECK. WARM AND HUMID CONDITIONS TO RULE MUCH OF THE EXTENDED PERIODS WITH LITTLE CHANGE IN AIRMASS FROM THE AFOREMENTIONED SITUATION. FAIRLY GOOD MODEL AGREEMENT WITH WEAK UPPER RIDGE FROM THE SOUTHERN PLAINS INTO THE GREAT LAKES THROUGH AT LEAST SATURDAY AND STRONG FORCING MECHANISM APPEAR LACKING...BUT ALSO LACKING IS STRONG CAPPING. SMALL PRECIPITATION CHANCES...NEAR CLIMATOLOGICAL VALUES FOR MID JUNE... WILL BE KEPT FOR THE BULK OF THESE PERIODS WITH TEMPS SOMEWHAT ABOVE NORMAL. 65 && .AVIATION... VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD. NORTH WINDS WILL PERSIST WITH GUSTS APPROACHING 20 KTS TODAY...BUT WILL TAPER OFF TO LIGHT NNE OR NEAR CALM AFTER SUNSET THROUGH THE REMAINDER OF THE TAF. BARJENBRUCH && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
642 AM CDT MON JUN 11 2012 ...UPDATE TO AVIATION... .DISCUSSION... STRONG MOISTURE CONVERGENCE CONTINUES IN FAR NORTHEAST KANSAS BEHIND SURFACE FRONT...WHICH LIES FROM ROUGHLY FROM KDSM TO KTOP TO KWLD AT 08Z. GUSTY NORTHEAST WINDS WERE REPORTED AT KMHK AT 08Z WITH OUTFLOW BOUNDARY SHOWING NEAR THE KTWX RADAR. MUCH DRIER AIR NOT FAR BEHIND WITH SURFACE DEWPOINTS IN THE UPPER 40S IN NORTH CENTRAL KANSAS AND LOWER 30S IN NORTHWEST KANSAS. WEAK MID LEVEL RETURNS SHOWING UP ON WESTERN KANSAS RADARS BUT LITTLE NEARING THE SURFACE IN MID LEVEL FRONTOGENESIS. 0Z 850MB TEMPS WERE VERY CLOSE TO 20C THROUGHOUT THE SURROUNDING STATES...THOUGH TEMPS BELOW 10C WERE SAMPLED IN MONTANA. WILL GO ALONG WITH HRRR AND RUC WITH CONVECTION SLOWLY PUSHING SOUTHEAST OUT OF THE AREA THIS MORNING AS THE MODIFIED CONTINENTAL AIRMASS MOVES IN. WESTERN MID LEVEL RETURNS SHOULD ENCOUNTER THIS DRIER AIR AND STILL STRUGGLE TO REACH THE GROUND. COLD AIR ADVECTION TAKES ITS TIME GETTING HERE HOWEVER...WITH SOMEWHAT INCREASED LEVELS COMING LATE IN THE DAY. WITH SOME EARLY DAY HIGH CLOUD AS WELL...THIS MAY KEEP NORTHERN AREAS IN THE MID 80S...WITH SOME UPPER 80S ALONG I-70 WHERE EARLY DAY DEBRIS IS MORE REMOVED AND BETTER CALL WILL HOLD OFF LONGER. TONIGHT INTO TUESDAY PERIODS LOOK RATHER QUIET WITH SURFACE HIGH PASSING ACROSS NEBRASKA AND IOWA AND 700-850MB RIDGING OVER EASTERN KANSAS. MAY SEE SOME HIGH CLOUD MOVE OUT OF THE ROCKIES TUESDAY WITH HIGHS A LITTLE COOLER THAN TODAY. MODELS HAVE BEEN FAIRLY CONSISTENT WITH A WEAK UPPER WAVE MOVING THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. SOUTHERLY LOW/MID LEVEL FLOW WILL SLOWLY INCREASE RESULTING IN WEAK ISENTROPIC LIFT WHILE PRECIPITABLE WATER VALUES RISE TO AROUND 1.3 INCHES BY LATE WEDNESDAY. COMBINED FORCING AND DEEPER MOISTURE MAY BE ENOUGH FOR SOME CONVECTION...THOUGH COVERAGE IS MUCH IN QUESTION AT THIS POINT. WILL KEEP POPS ON THE LOW SIDE WEDNESDAY AND WEDNESDAY NIGHT...KEEPING TUESDAY NIGHT DRY AT THIS POINT. WEAK MID LEVEL LAPSE RATES SHOULD KEEP STRONG INSTABILITY IN CHECK. WARM AND HUMID CONDITIONS TO RULE MUCH OF THE EXTENDED PERIODS WITH LITTLE CHANGE IN AIRMASS FROM THE AFOREMENTIONED SITUATION. FAIRLY GOOD MODEL AGREEMENT WITH WEAK UPPER RIDGE FROM THE SOUTHERN PLAINS INTO THE GREAT LAKES THROUGH AT LEAST SATURDAY AND STRONG FORCING MECHANISM APPEAR LACKING...BUT ALSO LACKING IS STRONG CAPPING. SMALL PRECIPITATION CHANCES...NEAR CLIMATOLOGICAL VALUES FOR MID JUNE... WILL BE KEPT FOR THE BULK OF THESE PERIODS WITH TEMPS SOMEWHAT ABOVE NORMAL. 65 && .AVIATION... CONVECTION HAS MOVED OFF TO THE SOUTHEAST OF THE TOP AND FOE TERMINALS. A MID CLOUD DECK QWITH SOME LOWER STRATUS WILL CLEAR OUT BY 15Z THIS MORNING. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NORTH TO NORTHWEST WIND NEAR 10 KTS EXPECTED THROUGH 12/01Z THEN BECOME NORTH NORTHEAST LESS THAN 5 KTS. 53 && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
326 AM CDT MON JUN 11 2012 .DISCUSSION... STRONG MOISTURE CONVERGENCE CONTINUES IN FAR NORTHEAST KANSAS BEHIND SURFACE FRONT...WHICH LIES FROM ROUGHLY FROM KDSM TO KTOP TO KWLD AT 08Z. GUSTY NORTHEAST WINDS WERE REPORTED AT KMHK AT 08Z WITH OUTFLOW BOUNDARY SHOWING NEAR THE KTWX RADAR. MUCH DRIER AIR NOT FAR BEHIND WITH SURFACE DEWPOINTS IN THE UPPER 40S IN NORTH CENTRAL KANSAS AND LOWER 30S IN NORTHWEST KANSAS. WEAK MID LEVEL RETURNS SHOWING UP ON WESTERN KANSAS RADARS BUT LITTLE NEARING THE SURFACE IN MID LEVEL FRONTOGENESIS. 0Z 850MB TEMPS WERE VERY CLOSE TO 20C THROUGHOUT THE SURROUNDING STATES...THOUGH TEMPS BELOW 10C WERE SAMPLED IN MONTANA. WILL GO ALONG WITH HRRR AND RUC WITH CONVECTION SLOWLY PUSHING SOUTHEAST OUT OF THE AREA THIS MORNING AS THE MODIFIED CONTINENTAL AIRMASS MOVES IN. WESTERN MID LEVEL RETURNS SHOULD ENCOUNTER THIS DRIER AIR AND STILL STRUGGLE TO REACH THE GROUND. COLD AIR ADVECTION TAKES ITS TIME GETTING HERE HOWEVER...WITH SOMEWHAT INCREASED LEVELS COMING LATE IN THE DAY. WITH SOME EARLY DAY HIGH CLOUD AS WELL...THIS MAY KEEP NORTHERN AREAS IN THE MID 80S...WITH SOME UPPER 80S ALONG I-70 WHERE EARLY DAY DEBRIS IS MORE REMOVED AND BETTER CALL WILL HOLD OFF LONGER. TONIGHT INTO TUESDAY PERIODS LOOK RATHER QUIET WITH SURFACE HIGH PASSING ACROSS NEBRASKA AND IOWA AND 700-850MB RIDGING OVER EASTERN KANSAS. MAY SEE SOME HIGH CLOUD MOVE OUT OF THE ROCKIES TUESDAY WITH HIGHS A LITTLE COOLER THAN TODAY. MODELS HAVE BEEN FAIRLY CONSISTENT WITH A WEAK UPPER WAVE MOVING THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY EVENING. SOUTHERLY LOW/MID LEVEL FLOW WILL SLOWLY INCREASE RESULTING IN WEAK ISENTROPIC LIFT WHILE PRECIPITABLE WATER VALUES RISE TO AROUND 1.3 INCHES BY LATE WEDNESDAY. COMBINED FORCING AND DEEPER MOISTURE MAY BE ENOUGH FOR SOME CONVECTION...THOUGH COVERAGE IS MUCH IN QUESTION AT THIS POINT. WILL KEEP POPS ON THE LOW SIDE WEDNESDAY AND WEDNESDAY NIGHT...KEEPING TUESDAY NIGHT DRY AT THIS POINT. WEAK MID LEVEL LAPSE RATES SHOULD KEEP STRONG INSTABILITY IN CHECK. WARM AND HUMID CONDITIONS TO RULE MUCH OF THE EXTENDED PERIODS WITH LITTLE CHANGE IN AIRMASS FROM THE AFOREMENTIONED SITUATION. FAIRLY GOOD MODEL AGREEMENT WITH WEAK UPPER RIDGE FROM THE SOUTHERN PLAINS INTO THE GREAT LAKES THROUGH AT LEAST SATURDAY AND STRONG FORCING MECHANISM APPEAR LACKING...BUT ALSO LACKING IS STRONG CAPPING. SMALL PRECIPITATION CHANCES...NEAR CLIMATOLOGICAL VALUES FOR MID JUNE... WILL BE KEPT FOR THE BULK OF THESE PERIODS WITH TEMPS SOMEWHAT ABOVE NORMAL. 65 && .AVIATION... PRIMARY UPPER LEVEL FORCING SHOULD EXIT THE AREA BY 06Z TAKING THE MAJORITY OF THE CONVECTION WITH IT SO HAVE WENT WITH A DRY FCST AT ALL TAFS SITES. HOWEVER...OUTFLOW BOUNDARY MAY STILL SERVE TO DEVELOP SOME ISOLATED CONVECTION BEFORE 09Z...BUT CHANCES APPEAR TOO LOW TO INCLUDE IN THE TERMINAL FCSTS. FRONT AND OUTFLOW COMBINATION WILL KEEP NORTH/NORTH WINDS THROUGH 12Z AND THEN INCREASE SLIGHTLY. ONLY SCT-BKN STRATOCU THROUGH 12Z THEN A FEW AC BEYOND 12Z. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS JACKSON KY
140 AM EDT MON JUN 11 2012 .UPDATE... ISSUED AT 140 AM EDT MON JUN 11 2012 WELL...RADAR CONTINUES TO PAINT LIGHT RETURNS ACROSS OUR SWRN COUNTIES BUT IT STILL APPEARS THAT VERY LITTLE OF THIS IS REACHING THE GROUND. MODELS CONTINUE TO RUN AMUCK WITH PRECIP OVERNIGHT BUT GENERALLY APPEAR TO BE OVER DOING THINGS BASED ON CURRENT OBS/TRENDS. WILL GO AHEAD AND SCALE POPS BACK A BIT FOR THE NEXT FEW HOURS BUT WILL ALSO KEEP SOME CHANCES IN FOR AROUND DAYBREAK. UPDATE ISSUED AT 1036 PM EDT SUN JUN 10 2012 LATEST NAM AND RUC HAVE REALLY BACKED OFF ON PRECIPITATION ACROSS SOUTHEAST KENTUCKY THROUGH THE REMAINDER OF THE NIGHT. THIS MAY BE DUE TO THE CONTINUED DOWNSLOPING (DRYING) FLOW. IF THIS IS THE CASE...MUCH OF THE AREA MAY GET ROBBED OVERNIGHT. HOWEVER...AREAS ALONG AND NORTH OF THE MOUNTAIN PARKWAY MAY NOT FEEL THIS INFLUENCE AS MUCH WITH DEWPOINTS POOLING A BIT HIGHER ACROSS THE AREA. THUS...THE NAM DEPICTION OF A BAND OF PRECIPITATION FORMING ACROSS OUR NORTH SEEMS REASONABLE AND WILL DRIFT NORTH TOWARDS DAYBREAK INTO NORTHERN KENTUCKY. MEANWHILE...LOW LEVEL JET WILL LIKELY BLOSSOM AN AREA OF SHOWERS ACROSS CENTRAL TENNESSEE LATE TONIGHT AND THESE WILL LIKELY PUSH NORTH ALONG THE I-75 CORRIDOR THROUGH DAYBREAK AND BEYOND. AGAIN...NOT SURE HOW MUCH INFLUENCE COULD BE ATTRIBUTED TO THE DOWNSLOPING FLOW...BUT THE EVOLUTION OF THIS SYSTEM WILL NEED TO BE WATCHED AS IT TOO COULD FALL APART AND BECOME MORE SCATTERED SHOWERS OR SPRINKLES AT BEST. REGARDLESS...STILL A BIT OF A CHANCE WE COULD END UP STAYING DRY IN SEVERAL AREAS THROUGH DAYBREAK AND PERHAPS WELL INTO MONDAY AS WELL. UPDATE ISSUED AT 806 PM EDT SUN JUN 10 2012 LOOKING AT ALL AVENUES IN WHICH WE COULD ACHIEVE THUNDER TONIGHT CAME BACK NEGATIVE. LIFTING PARCELS FROM MANY DIFFERENT LEVELS COULD NOT GENERATE ENOUGH INSTABILITY TO WARRANT THUNDER LATE TONIGHT. THIS IS SUPPORTED BY THE LACK OF LIGHTNING UPSTREAM. ALTHOUGH WE ARE ANTICIPATING NEW DEVELOPMENT...IT WILL LIKELY TRANSITION INTO MORE RAIN SHOWERS. IT WOULD TAKE SOME PRETTY VIGOROUS UPDRAFTS TO GET MOISTURE ABOVE THE VERY HIGH FREEZING LEVEL...THUS...FEEL SAFE REMOVING THUNDER. STILL NOT CONFIDENT TO GO ANY HIGHER WITH POPS...BUT WE MAY NEED TO GO HIGHER WITH A LATER UPDATE IF THINGS BEGIN TO DEVELOP AS EXPECTED. HOWEVER...AT THIS TIME...PREFER TO WAIT AND SEE AND STICK WITH OUR 60 TO 70 POPS. IT STILL LOOKS LIKE SHOWERS SHOULD BEGIN TO DEVELOP NEAR THE TENNESSEE BORDER AROUND 1 OR 2 AM...THEN SPREAD NORTHWARD...REACHING THE I-64 CORRIDOR BY 4 OR 5 AM...AND INTO NORTHERN KENTUCKY AROUND DAYBREAK. AFTER THE INITIAL SURGE OF MOISTURE AND RAIN...IT APPEARS WE COULD DRY OUT BEHIND THIS FEATURE TOMORROW MORNING...LEADING TO A DRIER PERIOD DURING THE MID MORNING HOURS. THEN WE MAY HAVE TO WAIT FOR DAYTIME INSTABILITY TO REFIRE THINGS IN THE AFTERNOON IF WE DON`T HAVE TOO MANY CLOUDS AROUND TO PREVENT THE DEVELOPMENT OF INSTABILITY. REGARDLESS...STILL PLENTY OF QUESTIONS SWIRLING AROUND TOMORROW`S FORECAST. GOING TO HOLD OFF TO MAKE ANY CHANGES AS MUCH WILL BE DETERMINED IN THE NEXT 6 TO 12 HOURS. UPDATE ISSUED AT 524 PM EDT SUN JUN 10 2012 DECIDED TO INTRODUCE A FEW HOURS OF SPRINKLES FOR AREAS SOUTH OF THE HAL ROGERS PARKWAY FOR THIS EVENING. CEILINGS ARE AROUND 5KFT...SO I IMAGINE A FEW DROPS ARE MAKING IT TO THE SURFACE. STILL LOOKS LIKE THE BEST FORCING WITH THE MAIN PRECIPITATION WILL HOLD OFF UNTIL AROUND OR SHORTLY AFTER MIDNIGHT. THE TARGETED AREAS EARLY...WILL BE NEAR THE TENNESSEE BORDER WITH THE THREAT FOR RAIN PUSHING INTO NORTHERN KENTUCKY TOWARDS DAYBREAK. DOWNSLOPING MAY KEEP INITIAL PRECIPITATION TOTALS ON THE LIGHT SIDE AND PERHAPS NOT EVEN MEASURABLE ACROSS SOUTHEAST KENTUCKY...BUT EVENTUALLY THE FORCING SHOULD WIN OUT. LOWER CLOUD DECK HAS BROUGHT SOME EARLIER COOLING INTO OUR SOUTHERN COUNTIES...SO HAVE ADJUSTED THE HOURLY TEMPERATURE TRACE TO REFLECT THIS EARLIER COOLING. NO NEED TO UPDATE ZONES WITH ANY OF THESE CHANGES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 259 PM EDT SUN JUN 10 2012 EASTERN KENTUCKY REMAINS SANDWICHED BETWEEN AN AREA OF SURFACE HIGH PRESSURE SITUATED OFF OF THE CAROLINA COAST...AND OCCLUDING LOW PRESSURE ACROSS SOUTH CENTRAL CANADA...LINKED TO A NEARLY STATIONARY FRONT ALIGNED NORTH TO SOUTH ALONG THE PLAINS. ALOFT...PLENTIFUL MOISTURE HAS BEEN FEEDING IN FROM THE SOUTHWEST OUT AHEAD OF A SLOW- MOVING SHORT WAVE TROUGH THAT HAS BEEN PLAGUING THE GULF COAST FOR THE PAST FEW DAYS. MEANWHILE...A MORE STOUT UPPER LEVEL TROUGH IS MOVING EAST ALONG THE U.S./CANADIAN BORDER. DOWNSLOPING SOUTHEASTERLY WINDS HAVE BEEN SCOURING OUT ANY PRECIPITATION THAT HAS TRIED TO MAKE IT IN FROM THE SOUTH TODAY...WITH ONLY A FEW SPRINKLES NOTED THUS FAR. THIS TREND LOOKS TO CONTINUE THROUGH THIS EVENING. THE MODELS ARE IN GOOD AGREEMENT WITH SLOWLY LIFTING THE GULF WAVE THROUGH THE TENNESSEE AND OHIO VALLEYS OVER THE NEXT 24 TO 36 HOURS AS IT GETS GRADUALLY INGESTED INTO THE MAIN WESTERLIES BY THE MORE DOMINATE NORTHERN STREAM WAVE. THIS WILL BRING ROUNDS OF SHOWERS AND ISOLATED TO SCATTERED THUNDER TO THE AREA BEGINNING LATER TONIGHT AND THROUGH THE DAY ON TUESDAY AS DEEP MOISTURE WILL BE IN PLACE...WITH PERIODS OF WEAK TO MODEST FORCING. DESPITE VERY HIGH PWATS FOR THIS TIME OF YEAR...AS HAS BEEN PREVIOUSLY NOTED...INSTABILITY CONTINUES TO BE IN QUESTION WITH SO MUCH CLOUD COVER...SO AM NOT CONFIDENT THAT THESE VALUES WILL BE REALIZED. STILL...WITH THIS KIND OF PATTERN IN PLACE...IT CERTAINLY CONTINUES TO BEAR WATCHING FOR LOCALLY HEAVY RAINERS. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 259 PM EDT SUN JUN 10 2012 LONG RANGE MODELS SHOW A RATHER BAGGY LONGWAVE PATTERN OVER THE SOUTHERN APPALACHIANS THROUGH THE REST OF THE WORK WEEK. BY THE WEEKEND...SOME AMPLIFICATION OCCURS AT 500 MB WITH RIDGING TAKING SHAPE OVER THE UPPER MIDWEST AND GREAT LAKES WHILE STUBBORN TROUGHINESS HANGS IN ALONG THE EASTERN SEABOARD. THE COLD FRONT AND UPPER LEVEL LOW WHICH WILL BRING THE EARLY WEEK RAINS WILL BE OFF TO OUR EAST BY TUESDAY NIGHT AND BROAD...WEAK HIGH PRESSURE WILL BUILD INTO THE APPALACHIANS FOR THE DURATION OF THE PERIOD. SENSIBLE WEATHER WILL FEATURE A FEW LINGERING SHOWERS TUESDAY NIGHT BEHIND OUR DEPARTING FRONTAL SYSTEM. THE REST OF THE PERIOD WILL LIKELY BE PRECIP FREE FOR MOST FOLKS AS A DRY NORTHEASTERLY FLOW DOMINATES. A FEW WEAK DISTURBANCES RETROGRADING TO THE SOUTHWEST UNDER THE BUILDING RIDGE OVER THE GREAT LAKES MAY KICK OFF AN ISOLATED SHOWER FRIDAY THROUGH SUNDAY. HOWEVER...SURFACE DEWPOINTS WILL BE FAIRLY LOW AND PWATS ONLY REBOUND TO AROUND AN INCH SO MODELS MAY BE OVERDOING THE QPF...AT LEAST ON THIS SIDE OF THE APPALACHIAN SPINE. AS SUCH...HAVE TRIMMED BACK ANY MENTION OF PRECIP TO JUST THE HIGHER TERRAIN AREAS ALONG THE TN AND VA BORDERS. TEMPERATURES ARE EXPECTED TO REMAIN PRETTY MUCH NEAR NORMAL THROUGH THE PERIOD...AND WITH COMFORTABLE DEWPOINTS. OVERNIGHT LOWS WILL LIKELY SNEAK INTO THE 50S MOST NIGHTS IN THE VALLEYS AS WELL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 140 AM EDT MON JUN 11 2012 VFR CONDITIONS WILL CONTINUE THROUGH THE OVERNIGHT HOURS BUT CIGS ARE EXPECTED TO BEGIN LOWERING WITH -RA POSSIBLE AT SME AND LOZ. STILL SOME UNCERTAINTY THOUGH AS TO HOW MUCH PRECIP WILL DEVELOP THROUGH 12Z AND WHAT THE END RESULT WILL BE ON FLIGHT CATS..BUT AM EXPECTING MVFR CONDITIONS TO MATERIALIZE AROUND DAYBREAK AND CONTINUE THROUGH THE DAY AS -SHRA BECOME MORE PREVALENT ACROSS ERN KY. STILL CANNOT RULE OUT SOME THUNDER DURING THE DAY AS WELL...BUT WITH UNCERTAINTY HERE AS WELL WILL CONTINUE TO ADVERTISE THIS WITH VCTS AT THE TAF SITES. A COLD FRONT CURRENTLY MOVING THROUGH THE MIDWEST IS EXPECTED TO BEGIN ENCROACHING ON THE AREA LATER TODAY/TONIGHT AND WILL KEEP UNSETTLED CONDITIONS WITH A CHANCE FOR MORE TSTMS THROUGH THE END OF THE PERIOD. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KAS/MB SHORT TERM...GEOGERIAN LONG TERM....ABE AVIATION...MB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1012 PM EDT TUE JUN 12 2012 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND SLOWLY CROSS THE REGION ON WEDNESDAY THEN MOVE EAST WEDNESDAY NIGHT. HIGH PRESSURE FROM NORTHERN CANADA WILL SLOWLY BUILD TOWARD THE REGION THROUGH THE REMAINDER OF THE WEEK INTO THE WEEKEND. && .NEAR TERM /THROUGH WEDNESDAY/... 1000 PM UPDATE: FORECAST ON TRACK, NO CHANGES NEEDED AT THIS TIME. 700 PM UPDATE: USING THE RUC MODEL AND RADAR TREND, HAVE DELAYED THE ONSET OF SHOWERS ACROSS MOST OF THE REGION FROM LATE TONIGHT UNTIL WEDNESDAY MORNING. ALSO INCREASED CLOUDS A BIT FASTER TONIGHT THAN PREVIOUS FORECAST BASED ON RH PROGS. PREVIOUS DISCUSSION: A COLD FRONT CURRENTLY STRETCHING FROM WESTERN QUEBEC SOUTHWARD THROUGH THE GREAT LAKES WILL CONTINUE TO TREK EASTWARD TONIGHT AND WILL PASS ACROSS THE STATE TOMORROW. THIS FEATURE IS PRODUCING A SWATH OF LIGHT TO MODERATE SHOWERS ACROSS EASTERN NEW YORK AND WESTERN NEW ENGLAND THIS AFTERNOON, AND THIS TOO WILL SHIFT EASTWARD. PRECIPITATION SHOULD REACH WESTERN SECTIONS LATE THIS EVENING, BY AROUND MIDNIGHT, BUT IT WILL BE EARLY TOMORROW MORNING BEFORE IT MAKES IT INTO EASTERN MAINE. NOT SEEING MUCH EVIDENCE OF SURFACE BASED OR ELEVATED INSTABILITY OVERNIGHT, SO THERE SHOULDN`T BE ANY THUNDER. HOWEVER HAVE INCLUDED THE CHANCE OF THUNDERSTORMS TOMORROW AFTERNOON WITH THE ACTUAL FRONTAL PASSAGE. HEAVY RAIN IS ALSO A POSSIBILITY AS PWATS WILL BE RUNNING HIGH, 1 TO 1.5+ INCHES, BUT GIVEN THAT THIS SYSTEM WILL BE WEAKENING AS IT MOVES THROUGH HAVE OPTED TO NOT INCLUDE HEAVY RAIN IN THE FORECAST FOR NOW. RAINFALL TOTALS WILL BE HIGHEST IN CENTRAL AND WESTERN MAINE, WHERE 0.50 TO 0.75 INCHES ARE EXPECTED THROUGH EARLY TOMORROW EVENING. AMOUNTS DROP OFF AS YOU MOVE SOUTH AND EAST, WITH A TENTH TO A THIRD OF AN INCH ACROSS EASTERN AND DOWNEAST MAINE. OVERNIGHT LOWS WILL BE MILD GIVEN THE INFLUX OF MOISTURE, WITH MOST LOCATIONS DROPPING INTO THE MID AND UPPER 50S. TOMORROW WILL BE MUCH COOLER THAN THE PREVIOUS COUPLE OF DAYS; HIGHS ARE EXPECTED TO BE IN THE MID AND UPPER 60S. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... MODELS APPEAR TO REASONABLY CONSISTENT WITH THE DEPARTURE TIME OF SHWRS E OF THE FA WED NGT WITH MAX THU 00-06Z QPF MSLY LESS THAN 0.10 INCHES FOR LOCATIONS EXPERIENCING RNFL...WITH ALL LOCATIONS DRYING BY THU MORN. WITH WINDS BECOMING N AT 5 TO 10 MPH BEHIND A COLD FRONT LATE WED NGT AND ERLY THU MORN...CURRENT THINKING IS THAT THERE WILL NOT BE MUCH TM FOR PATCHY FOG TO FORM IN THE WAKE OF RNFL...SO FOR NOW WE DID NOT INCLUDE ANY FOG IN THE GRIDS FOR THIS PD...BUT BRIEF FOG CANNOT BE COMPLETELY RULED FOR A FEW LOCATIONS. OTHERWISE...MODELS HAVE BACKED OFF OF KEEPING CLDNSS AND ASSOCIATED SHWRS WITH THE UPPER LOW SE OF NOVA SCOTIA ACROSS SRN PTNS OF THE FA THU INTO THU NGT...SO WE LOWERED POPS BLO SLGT CHC AND ALLOWED FOR AT LEAST PARTIAL CLRG. WITH HI PRES BOTH AT THE SFC ALD ALF SLOWLY SUBSIDING SWRD FROM NRN/CNTRL CAN...FAIR SKIES AND LGT WINDS WILL CONT INTO FRI. LOW AND HI TEMPS WED NGT THRU THU NGT SHOULD BE NEAR NORMAL FOR THIS TM OF SEASON...WITH A SLIGHT WARMING TREND BEGINNING ON FRI. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... A STRONG RIDGE OF HIGH PRESSURE IS EXPECTED TO REMAIN ACROSS THE NORTHEAST THIS WEEKEND THROUGH MUCH OF NEXT WEEK BRING EXCEPTIONALLY WARM WEATHER TO THE REGION. AFTER A CLEAR NIGHT FRIDAY NIGHT...SATURDAY IS EXPECTED TO BE SUNNY WITH HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT CRESTING OVER THE AREA. THE HIGH WILL REMAIN IN PLACE ON SUNDAY BRINGING ANOTHER MOSTLY SUNNY AND VERY WARM DAY. CLOUDS MAY INCREASE LATE IN THE DAY AS A WEAK SHORTWAVE SLIDES ACROSS THE NORTH AND SOME SCATTERED LATE DAY SHOWERS OR THUNDERSHOWERS ARE POSSIBLE ACROSS THE NORTH. SURFACE HIGH PRESSURE WILL THEN SLIDE SOUTH OF THE AREA EARLY NEXT WEEK. SOUTHWESTERLY WINDS JUST NORTH OF THE HIGH WILL THEN CHANNEL VERY WARM AIR INTO THE NORTHEAST FROM THE MIDWEST. THE WEAK DISTURBANCE OVER THE FAR NORTH MAY BRING SOME SHOWERS OR THUNDERSHOWERS ACROSS THE NORTH MONDAY INTO TUESDAY. OTHERWISE...THE DAYS WILL BE PARTLY CLOUDY...WARM AND HUMID. THE WARMEST AIR MAY THEN REACH THE STATE DURING MID WEEK WHEN TEMPS ON WEDNESDAY AND AGAIN ON THURSDAY COULD SOAR WELL INTO THE 80S AND POSSIBLY REACH 90 OR HIGHER IN SOME AREAS UNDER MOSTLY SUNNY SKIES. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: VFR CEILINGS WILL LOWER TO MVFR CEILING AFTER MIDNIGHT, AND REMAIN MVFR IN RAIN SHOWERS WEDNESDAY. CEILINGS WILL REMAIN MVFR THROUGH THE REMAINDER OF THE DAY AND MAY OCCASIONALLY DIP BELOW 1000 FT IN HEAVIER SHOWERS. SCATTERED THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON. SHORT TERM: ALL SITES WILL INITIALLY BEGIN MVFR WITH LOW CLGS AND OCNL VSBYS BETWEEN 3 TO 6 SM IN SHWRS WED EVE AND THEN IMPROVE TO VFR BY THU MORN BEHIND A COLD FRONT. ALL SITES SHOULD THEN CONT VFR THRU SUN. && .MARINE... NEAR TERM: A COLD FRONT WILL APPROACH THE WATERS LATE TONIGHT AND MOVE ACROSS THE AREA LATE TOMORROW. WHILE WINDS AND WAVES WILL INCREASE IN RESPONSE, THEY ARE EXPECTED TO REMAIN BELOW SMALL CRAFT LEVELS. THEREFORE, NO HEADLINES ARE NEEDED. SHORT TO LONG TERM: BOTH WINDS AND SEAS WILL REMAIN BLO SCA CRITERIA THRU SUN...WITH WINDS INCREASING TO 10 TO 15 KT FROM THE N BEHIND A COLD FRONT THU INTO THU NGT...THEN GRADUALLY DIMINISHING FRI INTO THE WEEKEND. USED A BLEND OF NAM12...GFS40 AND GMOS FOR WINDS AND KEPT CLOSE TO WW3 WV GUIDANCE FOR WV HTS... LOWERED FOR BAYS IMMEDIATELY ADJACENT TO THE COAST. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...FOSTER/HASTINGS SHORT TERM...VJN LONG TERM...BLOOMER AVIATION...FOSTER/HASTINGS MARINE...FOSTER/HASTINGS/VJN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
647 PM EDT MON JUN 11 2012 .SYNOPSIS... A COLD FRONT WILL BRING SHOWERS AND A CHANCE FOR THUNDERSTORMS TONIGHT INTO TUESDAY. HIGH PRESSURE IS THEN EXPECTED TO BRING DRY WEATHER THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... RADAR LOOP SHOWS WIDELY SCATTERED SHOWERS DEVELOPING OVER RLX THE PAST FEW HOURS AND SLOWLY MOVING NORTHWARD. LATEST HRRR AND RAP MODELS SUGGEST MORE SCATTERED SHOWERS TO DEVELOP TONIGHT BEFORE TAPERING OFF IN THE MID MORNING HOURS. THUS HAVE INCREASED POPS SLIGHTLY TO INCLUDE MORE CATEGORICAL AREAS TONIGHT. KEPT ONLY SLIGHT CHANCE OF THUNDER TONIGHT AS INSTABILITY REMAINS MINIMAL AND CIN BEGINNING TO FORM OVER THE REGION. COLD FRONT WILL THEN PASS ACROSS THE REGION TUESDAY AFTERNOON. SPC HAS CONTINUED TO INCLUDE THE AREA AS A `SEE TEXT` MENTION IN THE DAY 2 CONVECTIVE OUTLOOK. APPEARS THAT MODERATE INSTABILITY WILL BE PRESENT...BUT ONLY LOW VALUES OF WIND SHEAR WILL BE PRESENT. AT THIS POINT...APPEARS AS IF THERE WILL ONLY BE A MINIMAL CHANCE FOR SEVERE WEATHER. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... A CHANCE OF STORMS REMAINS EAST OF I-79 TUESDAY NIGHT...BUT ONLY THE RIDGES SHOULD HAVE A CHANCE FOR PRECIPITATION AFTER MIDNIGHT. BY WEDNESDAY MORNING HIGH PRESSURE WILL BE CENTERED OVER LOWER MICHIGAN...AND THE HIGH WILL DRIFT INTO QUEBEC THROUGH THE REST OF THE PERIOD. WITH LAKE ERIE TEMPERATURES STILL IN THE 60S AND NORTHERLY WINDS WEDNESDAY AND WEDNESDAY NIGHT...TEMPERATURES WILL BE A FEW DEGREES BELOW NORMAL DURING THAT TIME. AS WINDS SHIFT TO THE EAST FOR THURSDAY...HIGHS WILL RISE BY A FEW DEGREES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW UPPER LEVEL RIDGE BUILDING ACROSS THE EASTERN U.S. THIS PERIOD, AS UPPER LEVEL TROUGHING IS PROJECTED ACROSS THE WESTERN U.S. HENCE EXPECT THE UPPER OHIO VALLEY TO BE DRY THROUGH THE WEEKEND WITH TEMPERATURES EACH DAY SLIGHTLY WARMER THAN THE PREVIOUS. BLEND OF GFS AND ECMWF MOS SHOW TEMPERATURES FRIDAY TO BE NEAR NORMAL, THEN GRADUALLY WARMING TO VALUES 5 TO 8 DEGREES WARMER THAN NORMAL SUNDAY AND MONDAY. BY EARLY NEXT WEEK, THE SURFACE HIGH CENTER COULD BE OFFSHORE, BECOMING WHAT IS TERMED A BERMUDA HIGH, WHICH WOULD ALLOW WEAK LOWLEVEL SOUTHERLY WINDS TO BRING INCREASING HUMIDITY TO THE UPPER OHIO VALLEY. THIS WOULD PROMOTE A SLIGHT CHANCE OF LATE DAY INSTABILITY THUNDERSTORMS STARTING MONDAY OR TUESDAY. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... BLEND OF RECENT RADAR AND SURFACE DATA, COUPLED WITH HRRR AND WRF-NMM MODEL OUTPUT, SHOW A PREFRONTAL SURGE OF MVFR SHOWERS TO MOVE NORTHWARD THROUGH THE UPPER OHIO VALLEY THROUGH EARLY EVENING. AS SURFACE TEMPERATURES WARM PAST 78, ISOLATED THUNDERSTORMS CAN DEVELOP. MVFR CONDITIONS WILL BE PREVALENT TONIGHT, AND MAY LOWER TO IFR LATE TONIGHT, DEPENDING ON THE EXTENT THAT EVAPORATING RAINFALL SATURATES A NOCTURNALLY-COOLING SURFACE LAYER. WITH THE MODELS SHOWING SHOWER COVERAGE DECREASING BY MIDDAY TUESDAY, CONDITIONS CAN LIFT TO VFR PRIOR TO THE COLD FRONTAL PASSAGE, ALTHOUGH A FRONTAL BAND OF SHOWERS AND POSSIBLE THUNDERSTORMS CAN CAUSE A BRIEF TEMPORARY DROP TO MVFR TUESDAY AFTERNOON. SURFACE WINDS WILL BE MAINLY FROM THE SOUTH AT ABOUT 10 KTS THROUGH TUESDAY MORNING, WITH GUSTS TO 20 KTS POSSIBLE THIS AFTERNOON. SURFACE WINDS WILL BE WESTERLY TUESDAY AFTERNOON WITH THE COLD FRONTAL PASSAGE. .OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY... EXCEPT FOR POSSIBLE RESTRICTIONS EARLY WEDNESDAY MORNING IF FOG DEVELOPS, POST FRONTAL DRYING AND ENSUING HIGH PRESSURE SUBSIDENCE WILL PROMOTE VFR INTO THE WEEKEND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
330 PM EDT MON JUN 11 2012 .SYNOPSIS... A COLD FRONT WILL BRING SHOWERS AND A CHANCE FOR THUNDERSTORMS TONIGHT INTO TUESDAY. HIGH PRESSURE IS THEN EXPECTED TO BRING DRY WEATHER THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TUESDAY/... RADAR SHOWS THAT SHOWERS HAVE MADE PROGRESS ALL THE WAY TO INTERSTATE 80...ALTHOUGH EARLIER RETURNS THIS AFTERNOON HAVE BEEN VIRGA. SHOWERS HAVE BEEN QUITE SCATTERED IN COVERAGE...WITH NO THUNDERSTORMS IN THE REGION EITHER. HAVE CONTINUED TO BACK OFF POPS IN THE NEAR TERM...ALTHOUGH COVERAGE IS EXPECTED TO INCREASE OVER TIME. HAVE CONTINUED LIKELY/CATEGORICAL SHOWERS OVERNIGHT...ALTHOUGH AM CONCERNED THAT HIGH-RESOLUTION MODELS NEVER SHOW ANYTHING RESEMBLING STRATIFORM COVERAGE. WILL CONTINUE SLIGHT CHANCE FOR THUNDER OVERNIGHT AND INTO TUESDAY MORNING...ACCORDING TO SREF CALIBRATED PROBABILITIES. COLD FRONT WILL THEN PASS ACROSS THE REGION LATE TUESDAY MORNING INTO TUESDAY AFTERNOON. SPC HAS CONTINUED TO INCLUDE THE AREA AS A `SEE TEXT` MENTION IN THE DAY 2 CONVECTIVE OUTLOOK. APPEARS THAT MODERATE INSTABILITY WILL BE PRESENT...BUT ONLY LOW VALUES OF WIND SHEAR WILL BE PRESENT. AT THIS POINT...APPEARS AS IF THERE WILL ONLY BE A MINIMAL CHANCE FOR SEVERE WEATHER. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... A CHANCE OF STORMS REMAINS EAST OF I-79 TUESDAY NIGHT...BUT ONLY THE RIDGES SHOULD HAVE A CHANCE FOR PRECIPITATION AFTER MIDNIGHT. BY WEDNESDAY MORNING HIGH PRESSURE WILL BE CENTERED OVER LOWER MICHIGAN...AND THE HIGH WILL DRIFT INTO QUEBEC THROUGH THE REST OF THE PERIOD. WITH LAKE ERIE TEMPERATURES STILL IN THE 60S AND NORTHERLY WINDS WEDNESDAY AND WEDNESDAY NIGHT...TEMPERATURES WILL BE A FEW DEGREES BELOW NORMAL DURING THAT TIME. AS WINDS SHIFT TO THE EAST FOR THURSDAY...HIGHS WILL RISE BY A FEW DEGREES. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW UPPER LEVEL RIDGE BUILDING ACROSS THE EASTERN U.S. THIS PERIOD, AS UPPER LEVEL TROUGHING IS PROJECTED ACROSS THE WESTERN U.S. HENCE EXPECT THE UPPER OHIO VALLEY TO BE DRY THROUGH THE WEEKEND WITH TEMPERATURES EACH DAY SLIGHTLY WARMER THAN THE PREVIOUS. BLEND OF GFS AND ECMWF MOS SHOW TEMPERATURES FRIDAY TO BE NEAR NORMAL, THEN GRADUALLY WARMING TO VALUES 5 TO 8 DEGREES WARMER THAN NORMAL SUNDAY AND MONDAY. BY EARLY NEXT WEEK, THE SURFACE HIGH CENTER COULD BE OFFSHORE, BECOMING WHAT IS TERMED A BERMUDA HIGH, WHICH WOULD ALLOW WEAK LOWLEVEL SOUTHERLY WINDS TO BRING INCREASING HUMIDITY TO THE UPPER OHIO VALLEY. THIS WOULD PROMOTE A SLIGHT CHANCE OF LATE DAY INSTABILITY THUNDERSTORMS STARTING MONDAY OR TUESDAY. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... BLEND OF RECENT RADAR AND SURFACE DATA, COUPLED WITH HRRR AND WRF-NMM MODEL OUTPUT, SHOW A PREFRONTAL SURGE OF MVFR SHOWERS TO MOVE NORTHWARD THROUGH THE UPPER OHIO VALLEY THROUGH EARLY EVENING. AS SURFACE TEMPERATURES WARM PAST 78, ISOLATED THUNDERSTORMS CAN DEVELOP. MVFR CONDITIONS WILL BE PREVALENT TONIGHT, AND MAY LOWER TO IFR LATE TONIGHT, DEPENDING ON THE EXTENT THAT EVAPORATING RAINFALL SATURATES A NOCTURNALLY-COOLING SURFACE LAYER. WITH THE MODELS SHOWING SHOWER COVERAGE DECREASING BY MIDDAY TUESDAY, CONDITIONS CAN LIFT TO VFR PRIOR TO THE COLD FRONTAL PASSAGE, ALTHOUGH A FRONTAL BAND OF SHOWERS AND POSSIBLE THUNDERSTORMS CAN CAUSE A BRIEF TEMPORARY DROP TO MVFR TUESDAY AFTERNOON. SURFACE WINDS WILL BE MAINLY FROM THE SOUTH AT ABOUT 10 KTS THROUGH TUESDAY MORNING, WITH GUSTS TO 20 KTS POSSIBLE THIS AFTERNOON. SURFACE WINDS WILL BE WESTERLY TUESDAY AFTERNOON WITH THE COLD FRONTAL PASSAGE. .OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY... EXCEPT FOR POSSIBLE RESTRICTIONS EARLY WEDNESDAY MORNING IF FOG DEVELOPS, POST FRONTAL DRYING AND ENSUING HIGH PRESSURE SUBSIDENCE WILL PROMOTE VFR INTO THE WEEKEND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
209 PM EDT MON JUN 11 2012 .SYNOPSIS... A COLD FRONT WILL BRING SHOWERS AND STORMS THIS AFTERNOON THROUGH TUESDAY, FOLLOWED BY DRY AND SEASONABLE CONDITIONS WEDNESDAY INTO FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... WITH 115PM UPDATE...HAVE BACKED OFF PRECIPITATION BY A FEW MORE HOURS IN MOST LOCATIONS. LOW LEVEL MOISTURE IS TAKING ITS TIME MOVING INTO THE AREA...AND RADAR HAS BEEN SHOWING A LOT OF VIRGA. THE VIRGA SHOULD EVENTUALLY MOISTEN LOW LEVELS AND ALLOW RAIN AT THE SURFACE. ALSO TWEAKED AFTERNOON TEMPERATURES...BUMPING UP NORTHERN COUNTIES UP A DEGREE OR TWO AND DECREASING TEMPERATURES ACROSS EASTERN OHIO WHERE RAINFALL HAS ALREADY ARRIVED. PREVIOUS DISCUSSION FOLLOWS. BASED ON RECENT SATELLITE DATA AND NAM MODEL OUTPUT, EXPECT SKIES TO BECOME MOSTLY CLOUDY ACROSS THE WHOLE UPPER OHIO VALLEY BY MIDDAY, AS DEEP MOISTURE MOVES INTO THE REGION WITH UPPER LEVEL SHORTWAVE MOVING NORTH FROM THE TENNESSEE VALLEY. THIS WILL MERGE WITH A COLD FRONT AND A DEEPER TOUGH MOVING EAST FROM THE UPPER GREAT LAKES TO PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT. RAINFALL AMOUNTS OVER ONE HALF INCH WITH LOCALLY AN INCH EXPECTED. SEVERE THREAT WILL BE LIMITED BY A LACK OF LOW LEVEL INSTABILITY AT THE SURFACE AND BEST UPPER LEVEL DYNAMICS WELL WEST OF REGION. WITH MID AND UPPER LEVEL CLOUDS ALREADY ENTERING REGION LOWERED MAX TEMPS TOWARD MAV MOS. QUITE MILD AND HUMID TONIGHT AHEAD OF FRONT. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... SHOWERS AND THUNDERSTORMS WILL BE LIKELY TUESDAY UNTIL THE COLD FRONTAL PASSAGE AND LOW LEVEL DRYING TOWARD EVENING. ISOLATED SEVERE THREAT WITH AMOUNT OF AVAILABLE INSTABILITY IN DOUBT AS WELL AS WEAKENING UPPER LEVEL DYNAMICS. TRENDED TOWARD THE NAM AND ECMWF FOR SHOWERS TO DIMINISH WEST TO EAST TUESDAY EVENING AS DRY AIR WORKS ACROSS REGION. MODELS THEN IN GOOD OVERALL AGREEMENT FOR DRY HIGH PRESSURE TO MOVE EAST WITH MUCH LOWER DEW POINTS AND NEAR NORMAL TEMPERATURES WEDNESDAY AND THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW UPPER LEVEL RIDGE BUILDING ACROSS THE EASTERN U.S. THIS PERIOD, AS UPPER LEVEL TROUGHING IS PROJECTED ACROSS THE WESTERN U.S. HENCE EXPECT THE UPPER OHIO VALLEY TO BE DRY THROUGH THE WEEKEND WITH TEMPERATURES EACH DAY SLIGHTLY WARMER THAN THE PREVIOUS. BLEND OF GFS AND ECMWF MOS SHOW TEMPERATURES FRIDAY TO BE NEAR NORMAL, THEN GRADUALLY WARMING TO VALUES 5 TO 8 DEGREES WARMER THAN NORMAL SUNDAY AND MONDAY. BY EARLY NEXT WEEK, THE SURFACE HIGH CENTER COULD BE OFFSHORE, BECOMING A WHAT IS TERMED A BERMUDA HIGH, WHICH WOULD ALLOW WEAK LOWLEVEL SOUTHERLY WINDS TO BRING INCREASING HUMIDITY TO THE UPPER OHIO VALLEY AND SO PROMOTE A SLIGHT CHANCE OF LATE DAY INSTABILITY THUNDERSTORMS STARTING MONDAY OR TUESDAY. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... BLEND OF RECENT RADAR AND SURFACE DATA, COUPLED WITH HRRR AND WRF-NMM MODEL OUTPUT, SHOW A PREFRONTAL SURGE OF MVFR SHOWERS TO MOVE NORTHWARD THROUGH THE UPPER OHIO VALLEY THROUGH EARLY EVENING. AS SURFACE TEMPERATURES WARM PAST 78, ISOLATED THUNDERSTORMS CAN DEVELOP. MVFR CONDITIONS WILL BE PREVALENT TONIGHT, AND MAY LOWER TO IFR LATE TONIGHT, DEPENDING ON THE EXTENT THAT EVAPORATING RAINFALL SATURATES A NOCTURNALLY-COOLING SURFACE LAYER. WITH THE MODELS SHOWING SHOWER COVERAGE DECREASING BY MIDDAY TUESDAY, CONDITIONS CAN LIFT TO VFR PRIOR TO THE COLD FRONTAL PASSAGE, ALTHOUGH A FRONTAL BAND OF SHOWERS AND POSSIBLE THUNDERSTORMS CAN CAUSE A BRIEF TEMPORARY DROP TO MVFR TUESDAY AFTERNOON. SURFACE WINDS WILL BE MAINLY FROM THE SOUTH AT ABOUT 10 KTS THROUGH TUESDAY MORNING, WITH GUSTS TO 20 KTS POSSIBLE THIS AFTERNOON. SURFACE WINDS WILL BE WESTERLY TUESDAY AFTERNOON WITH THE COLD FRONTAL PASSAGE. .OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY... EXCEPT FOR POSSIBLE RESTRICTIONS EARLY WEDNESDAY MORNING IF FOG DEVELOPS, POST FRONTAL DRYING AND ENSUING HIGH PRESSURE SUBSIDENCE WILL PROMOTE VFR INTO THE WEEKEND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 PM EDT TUE JUN 12 2012 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 325 PM EDT TUE JUN 12 2012 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PROGRESSIVE UPR TROF EXTENDING FM HUDSON BAY INTO THE GRT LKS MOVING E IN ADVANCE OF UPR RDG OVER WRN CANADA. SHRTWV EMBEDDED WITHIN THIS TROF BROUGHT LOTS OF CLDS AND SOME -SHRA TO MAINLY THE NRN TIER INTO EARLY AFTN... BUT TREND THIS AFTN HAS BEEN FOR MORE SUNSHINE AS DNVA/ LARGER SCALE QVECTOR DVGC/MORE ACYC FLOW AND DRIER AIR SHOWN ON THE 12Z INL RAOB IS FOLLOWING IN THE WAKE OF THAT DISTURBANCE IN ADVANCE OF SFC HI PRES CENTERED OVER SE SDAKOTA. SKIES ARE MOCLR FM THE HI CENTER STRETCHING TOWARD LK WINNIPEG...WHERE THE 12Z RAOB AT THE PAS IN MANITOBA SHOWS A PWAT OF 0.28 INCH. SFC DEWPTS THIS AFTN HAVE MIXED OUT INTO THE LO-MID 30S IN THIS UPSTREAM AIRMASS. MORE CLDS ARE PRESENT A BIT FARTHER W IN THE NRN PLAINS IN THE RETURN SW FLOW ARND THE SFC HI AND IN ADVANCE OF SHRTWV TRACKING E ACRS WYOMING/MONTANA. 12Z BIS RAOB SHOWS MORE MSTR/PWAT OF 0.70 INCH NEAR THE WAD CLD BAND. MAIN FCST CONCERNS IN THE SHORT TERM REVOLVE ARND CLRG TRENDS THIS AFTN AND THEN TEMPS/POTENTIAL FOR FROST TNGT. TNGT...SFC HI PRES IS FCST TO MOVE E AND TO OVER NRN LWR MI BY 12Z WED. EXPECT ANY LINGERING CLDS TO DSPT LATE THIS AFTN/EARLY THIS EVNG WITH THE ARRIVAL OF MORE ACYC FLOW AND WARMER/DRIER AIR AT H925. STRONGER WSW FLOW ARND SFC HI IS FCST TO DVLP OVER THE NW HALF OF THE CWA AFT 06Z...WITH PWAT RISING AS THIS FLOW TAPS MORE MSTR SHOWN ON THE 12Z BIS RAOB. MOST SUSTAINED CONDITIONS FOR RADIATIONAL COOLING LOOK TO BE OVER THE SCNTRL AND E...WHERE THE GRADIENT FLOW WL REMAIN WEAKER/PWAT LOWER AND UNDER 0.5 INCH THRU 12Z WED. OPTED TO EXTEND GOING FROST ADVY NEAR THE WI BORDER TO INCLUDE MOST OF THE CWA FROM BARAGA TO THE E...WITH MIN TEMPS CLOSER TO THE LOWER END OF GUIDANCE IN THESE AREAS PER OBSVD MIXING OF DEWPTS UPSTREAM. WED...AS SFC HI PRES DRIFTS SLOWLY E ACRS LK HURON...STRONGER SW FLOW WL DVLP OVER THE ENTIRE CWA. WITH APRCH OF DISTURBANCE NOW MOVING THRU THE NRN PLAINS AND SOME MSTR RETURN...EXPECT AT LEAST SOME CLDS TO INVADE MAINLY THE WRN ZNS IN THE AFTN. ALTHOUGH THE GFS GENERATES SOME PCPN OVER THE FAR W LATE IN THE DAY...PREFER TO FOLLOW THE DRY 12Z NAM/CNDN/LOCAL WRF-ARW DUE TO VERY DRY NATURE OF LLVL AIRMASS. MIXING TO H8 ON NAM FCST SDNGS YIELDS HI TEMPS REBOUNDING TO 70 TO 75 AWAY FM LK MODERATION. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 PM EDT TUE JUN 12 2012 THE WEAK HIGH PRESSURE RIDGE IN PLACE FOR WEDNESDAY WILL SLIDE EASTWARD AS A TROUGH OVER THE CANADIAN PRAIRIE DIGS DOWN INTO THE NORTHERN PLAINS. MODELS AGREE THAT A SHORTWAVE WILL BE APPROACHING WESTERN UPPER MICHIGAN BY 00Z THURSDAY...THOUGH THERE SEEMS TO BE DIFFERENCES WITH HOW STRONG IT WILL BE. THE GEM/ECMWF SEEM TO AGREE ON A WEAKER SOLUTION...WHILE THE GFS DEVELOPS A SMALL TROUGH. THE GFS ALSO AMPLIFIES THE EXITING RIDGE MUCH MORE THAN THE OTHER MODELS. WILL STICK WITH A BLEND MORE SIMILAR TO THE GEM/ECMWF FOR NOW GIVEN THEIR AGREEMENT...THOUGH CONFIDENCE IS NOT VERY HIGH. THIS KEEPS MOST OF THE PRECIPITATION THAT WILL OCCUR WITH THIS SHORTWAVE OVER WESTERN LAKE SUPERIOR AND THE WEST HALF OF THE CWA. WILL KEEP LOW CHANCE POPS OVER THESE AREAS TO ACCOUNT FOR UNCERTAINTY DURING THE DAY ON THURSDAY. MODEL SOUNDINGS SUGGEST MIXING TO AROUND 850MB...WHICH PUTS HIGHS IN THE 70S AND PERHAPS LOW 80S. DESPITE INCOMING CLOUD COVER WITH THE SHORTWAVE...EXPECT THE WARMEST TEMPERATURES TO BE OUT WEST WITH THE HIGHEST 850MB TEMPS OF AROUND 13C. WITH SKIES MOSTLY SUNNY OUT EAST...EXPECT MIXING TO BRING RELATIVE HUMIDITY DOWN INTO THE 30 PERCENT RANGE. WITH THE STRONGER PRESSURE GRADIENT ASSOCIATED WITH THE LOW PRESSURE SYSTEM...EXPECT GUSTY SOUTHERLY TO SOUTHEASTERLY WINDS ACROSS MUCH OF THE AREA...MAINLY NORTH CENTRAL AND OVER LAKE SUPERIOR. HIGHEST GUSTS ARE EXPECTED TO BE AROUND 25 KNOTS. FRIDAY THE TROUGH WILL SWING JUST NORTH OF LAKE SUPERIOR...REACHING HUDSON BAY BY 00Z SATURDAY. MODELS SEEM TO BE IN FAIRLY GOOD AGREEMENT ON THE AMOUNT OF QPF ASSOCIATED WITH THE PASSING FRONT ACROSS WEST AND CENTRAL UPPER MICHIGAN...WITH AROUND 0.25-0.50 INCH IMPACTING THE AREA. THE NAM BRINGS THE FRONT ALL THE WAY THROUGH THE CWA...BRINGING 0.25 INCH TO THE EASTERN AREAS. THE ECMWF/GEM/GFS TAKE THE BEST UPPER LEVEL FORCING NORTHWARD /PER 850-500MB QVECTOR CONVERGENCE/ AND THEREFORE KEEP MUCH OF THE EASTERN CWA DRY. THERE ARE ALSO DIFFERENCES IN TIMING OF PRECIPITATION...SO HAVE LOWERED CONFIDENCE IN PUTTING SPECIFICS INTO THE FORECAST. KEPT THE BEST CHANCES OVER LAKE SUPERIOR AND ACROSS THE WEST AND CENTRAL. MU/ML CAPE VALUES THURSDAY NIGHT INTO FRIDAY AFTERNOON RANGE FROM AROUND 200-1000 J/KG...SO KEPT THUNDER CHANCES IN. WITH PRESSURE GRADIENT REMAINING TIGHT...WINDS WILL CONTINUE TO GUST INTO THE 20-25 KNOT RANGE THROUGH FRIDAY EVENING. FOR THE EXTENDED /THE WEEKEND INTO TUESDAY/... FOR THE MOST PART...IT SEEMS THROUGH THE WEEKEND A RIDGE WILL CENTER ITSELF OVER LOWER MICHIGAN...AND SHORTWAVES WILL RIDE AROUND THE IT BRINGING CHANCES OF PRECIPITATION. FOR THE FIRST PART OF THE WORK WEEK...A STRONGER LOW PRESSURE TROUGH WILL SWING INTO THE NORTHERN PLAINS AND BRING ADDITIONAL PRECIPITATION/THUNDERSTORMS TO MUCH OF THE CWA. HOWEVER...MODELS DIFFER ON TIMING AND PLACEMENT OF FEATURES. THE GFS/GEM BRING A STRONGER RIDGE UP FROM THE PLAINS...KEEPING MUCH OF THE PRECIPITATION ASSOCIATED WITH A SECOND TROUGH/SHORTWAVE CONFINED TO THE WESTERN CWA OR NOT IN THE UPPER PENINSULA AT ALL. THE GFS EVENTUALLY DEVELOPS THE TROUGH INTO A CLOSED LOW...AND THEN MOVES THE PRECIPITATION THROUGH ON MONDAY. THE ECMWF KEEPS THE RIDGE FURTHER SOUTH AND EAST...AND BRINGS A MUCH MORE POTENT SHORTWAVE INTO UPPER MICHIGAN SATURDAY MORNING INTO MONDAY. WITH SUCH A VARIANCE IN SOLUTIONS...DO NOT FEEL CONFIDENT BUMPING UP ANY POPS. WILL KEEP THE MENTION OF THUNDER AS MODELS SEEM TO BRING IN A DECENT AMOUNT OF INSTABILITY THROUGH THE WEEKEND. AS FOR HIGH TEMPERATURES...850MB TEMPS LOOK TO BE IN THE 16-18C RANGE...SO WILL KEEP FORECASTED HIGHS IN THE UPPER 70S TO THE MID 80S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 720 PM EDT TUE JUN 12 2012 HIGH PRESSURE TO DOMINATE THE REGION THROUGH THE FORECAST... RESULTING IN VFR CONDITIONS. WINDS TO BE LIGHT OVERNIGHT AS THE PRESSURE GRADIENT RELAXES AND THE BOUNDARY LAYER DECOUPLES. AS THE HIGH SHIFTS OVER NORTHERN LOWER MICHIGAN ON WEDNESDAY...SOUTHWEST WINDS TO PICK UP OVER THE AREA WITH SOME GUSTS TO 20 KTS AT KIWD. INCREASING MID CLOUDS AND WINDS BACKING TO THE SOUTH TO SOUTHEAST LATE IN THE FORECAST IN RESPONSE TO APPROACHING LOW PRESSURE SYSTEM. THIS FEATURE COULD BRING AN ISOLATED SHOWER OR THUNDERSTORM TO IWD BY 0Z THURSDAY...BUT WITH BETTER FORCING AND MOISTURE WELL TO THE WEST WILL LEAVE OUT AT THIS TIME. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 325 PM EDT TUE JUN 12 2012 EXPECT NW WINDS UP TO 25-30 KTS INTO THIS EVENING OVER THE E TO DIMINISH OVERNIGHT WITH THE ARRIVAL OF A HI PRES RIDGE. THESE LIGHT WINDS WILL PERSIST INTO WED NIGHT AS THE HI REMAINS DOMINANT. THEN A STRONGER S WIND UP TO 25 KTS WILL IMPACT MAINLY THE NCENTRAL AND E PART OF THE LAKE ON THU/FRI UNDER A TIGHTER PRES GRADIENT BETWEEN THE HI DEPARTING TO THE E AND A LO PRES TROF APPROACHING FROM THE W. THEN LIGHTER WINDS WILL PREVAIL AGAIN THIS COMING WEEKEND WITH A WEAKER PRES GRADIENT FORECAST TO DOMINATE THE UPPER LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FROST ADVISORY FROM 1 AM EDT /MIDNIGHT CDT/ TO 7 AM EDT /6 AM CDT/ WEDNESDAY FOR MIZ002-004>007-009>014-084-085. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...MCB AVIATION...RJT MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
419 PM EDT MON JUN 11 2012 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 419 PM EDT MON JUN 11 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A FAIRLY DEEP TROF AND ASSOC STRONG SHORTWAVE MOVING FM ND INTO NW MN. THE EASTWARD MOVEMENT OF THIS SHORTWAVE IS HELPING TO SLOWLY PUSH A SFC COLD FRONT ACROSS WRN UPPER MI THIS AFTERNOON. LATEST 19Z SFC PLOT/ANALYSIS SHOWS THE FRONT IS ALONG A CRYSTAL FALLS-MICHIGAMME LINE. ALTHOUGH 12Z MODEL SNDGS INDICATE IN EXCESS OF 1000 J/KG MLCAPE WITH T/TD OF 82/63...VIS SATELLITE LOOP SHOWS LITTLE DVLPMT TO CU FIELD UPSTREAM OVER CENTRAL UPPER MI OR IMMEDIATELY UPSTREAM OVER NRN WI. SUSPECT THAT DRY ALOFT MOVING IN AHEAD OF THE SHORTWAVE AS NOTED ON VERY DRY 12Z KMPX SNDGS MAY BE INHIBITING CU DVLPMT OVER THE FCST AREA. TONIGHT...GIVEN LACK OF CU DVLPMT ON VIS SATELLITE MAY END UP EVENTUALLY HAVING TO BACK OFF ON POPS TO SLIGHT CHC OVER CENTRAL AND ERN COUNTIES FOR THIS EVENING AHEAD OF APPROACHING FRONT. IF SOME CONVECTION IS ABLE TO FIRE ALONG THE FRONT...THERE IS A CHANCE FOR AN ISOLATED STRONG TO SVR STORM GIVEN THE INSTABILITY AND DEEP LAYER SHEAR GREATER THAN 40 KTS OVER THE AREA. RELUCTANT TO PULL POPS OUT COMPLETELY SINCE FRONT IS STILL APPROACHING BUT CHC OF PCPN IS LOOKING MORE AND MORE DOUBTFUL THIS EVENING OVER CENTRAL AND ERN CWA. MODEL SNDGS INDICATE WEST WINDS ARE EXPECTED TO PICK UP BEHIND THE FRONT THIS EVENING ESPECIALLY OVER THE KEWEENAW PENINSULA WHERE PASSAGE OF SECONDARY COLD FRONT AND INCREASING MIXING/INSTABILITY WITH COLDER AIR COMING IN MAY PRODUCE GUSTS TO 40 MPH. LOOK FOR LOWS TO REACH INTO THE MID 40S WEST TO MID 50S SOUTH CENTRAL AND EAST. TUESDAY...THE 500MB TROUGH AXIS WILL MOVE ACROSS THE AREA MIDDAY ALONG WITH THE 8H THERMAL TROF AS 850 MB TEMPS LOWER TO AROUND 0C. WITH GOOD CAA IN THE WNW FLOW OVER THE AREA. WITH LIMITED MIXING ALONG THE LAKE SUPERIOR SHORE EXPECT HIGHS IN THE LOWER TO MID 50S WHILE DEEPER SOUTH CENTRAL WILL YIELD HIGHS IN THE LOWER TO MID 60S. INCREASINGLY ANTICYCLONIC SFC-850 MB FLOW AND RDGG BUILDING IN FROM THE WEST SHOULD SCOUR OUT LOW CLOUDS FROM WEST TO EAST IN THE AFTERNOON. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 419 PM EDT MON JUN 11 2012 THE SFC HIGH SHOULD BE DIRECTLY OVERHEAD FROM 00-06Z WEDNESDAY...BEFORE SHIFTING OFF TO QUEBEC WEDNESDAY AFTERNOON INTO THURSDAY. SIMILAR TO A FEW DAYS AGO...WE WILL MONITOR THE DEVELOPMENT OF AN ELONGATED SFC LOW STRETCHING FROM S CENTRAL CANADA THROUGH THE CO ROCKIES. FROST WILL REMAIN POSSIBLE TUESDAY NIGHT/WEDNESDAY MORNING...WITH TEMPS BOTTOMING OUT 31-36F INLAND FROM THE GREAT LAKES AS WINDS GO NEARLY CALM AND CLOUDS DISSIPATE. WEDNESDAY WILL LIKELY BE A BIT DRIER THAN ORIGINALLY THROUGH...WITH MIXED DEW POINTS IN THE MID 20S BY 18Z. THIS SCENARIO WOULD RESULT IN MIN RH VALUES NEAR 20 PERCENT OVER THE WEST HALF OF UPPER MI...AND 25-30 PERCENT EAST. EXPECT THE RETURN OF LIGHT/SOUTHERLY FLOW AS THE HIGH SHIFTS ACROSS LAKE HURON AND STRETCHES THROUGH QUEBEC...STILL BELOW 15MPH. DID PUSH THE FCST CLOSER TO THESE LOWEST VALUES. THE ELONGATED SFC LOW STRETCHING FROM SOUTHERN SASKATCHEWAN/MANITOBA THROUGH THE DAKOTAS AND E CO/NM THURSDAY MORNING WILL CONTINUE TO REMAIN NEARLY STEADY. ALTHOUGH THURSDAY SHOULD BE WARMER...WITH INCREASED SOUTHERLY WINDS /20-35KTS BETWEEN THE SFC AND 850MB/...MOISTURE SHOULD BE ON THE INCREASE AS WELL. MIN RH VALUES COULD STILL NEAR 30 PERCENT OVER PORTIONS OF INTERIOR W UPPER MI BY LATE MORNING/EARLY AFTERNOON. THE FCST FOR SUNDAY MONDAY REMAINS VERY UNCERTAIN...SO DID NOT GO TOO FAR IN DEPTH WITH ADJUSTMENTS FOR THAT PERIOD. THE WESTERN SFC LOW WILL BE LOCATED SOMEWHERE BETWEEN NWS ONTARIO AND MN BY 12Z MONDAY...WITH THE TRAILING COLD FRONT STILL REMAINING TO OUR W BY THE END OF THE DAY. THE RESULT SHOULD BE ANOTHER ROUND OF WARM/HOT WEATHER SATURDAY THROUGH MONDAY...AS S WINDS REMAIN STEADY AND 850MB TEMPS RISE AGAIN TO 16 TO 20C. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 155 PM EDT MON JUN 11 2012 VFR CONDITIONS SHOULD PREVAIL INTO THE EVENING HRS AT KIWD/KCMX/KSAW. SCT -SHRA/-TSRA COULD FORM BTWN 18-00Z IN VCNTY OF KSAW ALONG INCOMING COLD FRONT BUT GIVEN CONSIDERABLE UNCERTAINTY IN PLACEMENT/COVERAGE OF AFTN CONVECTION DUE TO CLOUD COVER...SHRA/TSRA WERE NOT MENTIONED AT KSAW. WEST WINDS COULD BECOME GUSTY AND PICK UP SUBSTANTIALLY AT KIWD AND ESPECIALLY KCMX AS A SECONDARY COLD FRONT PASSES THRU THE AREA LATE AFTN/EVENING. LOOKING UPSTREAM...MVFR CIGS COULD DEVELOP OVERNIGHT AT KIWD AND KCMX AND THEN LATE TUE MORNING AT KSAW WITH PASSAGE OF SECONDARY COLD FRONT. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 419 PM EDT MON JUN 11 2012 LOW PRESSURE ACROSS HUDSON BAY WILL KEEP A TROUGH ACROSS LS THIS EVENING...AHEAD OF HIGH NEARING FROM THE WEST. EXPECT THE HIGH OVER MINNESOTA TUESDAY MORNING TO PUSH ACROSS THE UPPER GREAT LAKES TUESDAY AFTERNOON THROUGH WEDNESDAY...BEFORE EXITING ACROSS QUEBEC WEDNESDAY NIGHT. W-NW GUSTS OF 30 TO POSSIBLY 30KTS WILL SLIDE IN OVERNIGHT AND LINGER THROUGH THE DAY TUESDAY. A RIDGE WILL REMAIN ACROSS LS THROUGH SATURDAY...AS AN ELONGATED AREA OF LOW PRESSURE ORGANIZES ACROSS THE CENTRAL AND NORTHERN PLAINS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...KF AVIATION...VOSS MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
157 PM EDT MON JUN 11 2012 .SHORT TERM...(TODAY) ISSUED AT 518 AM EDT MON JUN 11 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A FAIRLY DEEP TROF MOVING ACROSS THE NRN PLAINS. AS EXPECTED DUE TO WEAKENING INSTABILITY... SHRA/TSRA THAT DEVELOPED YESTERDAY AFTN AHEAD OF COLD FRONT IN MN DIMINISHED AS THEY APPROACHED UPPER MI EARLIER IN THE NIGHT. HOWEVER...A LINGERING RIBBON OF MUCAPE WHICH HAS RECENTLY INCREASED TO 500-1000J/KG PER LATEST SPC MESOANALYSIS IS SUPPORTING SCT SHRA/TSRA WHICH ARE SPREADING/DEVELOPING NE INTO THE WRN FCST AREA AS OF 09Z. MAIN CONCERN IN THE SHORT TERM REVOLVES AROUND REDEVELOPMENT OF CONVECTION TODAY AS COLD FRONT DRIFTS ACROSS THE AREA. SHRA/TSRA SPREADING INTO WRN UPPER MI WILL PROBABLY PERSIST FOR THE NEXT FEW HRS GIVEN AVBL INSTABILITY. COLD FRONT SHOULD THEN CLEAR THE W BEFORE REDEVELOPMENT CAN OCCUR TODAY. TO THE E...DEBRIS CLOUDS FROM SHRA/TSRA WILL PROBABLY THIN OUT SUFFICIENTLY TO ALLOW FOR DECENT HEATING AHEAD OF THE COLD FRONT AS IT MOVES ACROSS CNTRL UPPER MI THIS AFTN. UTILIZING MODIFIED NAM FCST SOUNDINGS FOR T/TD OF MID 80S/LWR 60S PRIOR TO MODEL GENERATED PCPN (GFS SOUNDING CONTAMINATED BY PCPN) YIELDS SBCAPE IN THE 1000-1500J/KG RANGE. WITH DEEP LAYER SHEAR OF 30-40KT...THERE WILL BE THE POTENTIAL FOR ORGANIZED STORMS AND SVR WX. HIGH RES MODELS GIVE CONFLICTING SIGNALS ABOUT WHETHER CONVECTION WILL REDVELOP AS SEVERAL INDICATE LITTLE OR NO REGENERATION TODAY. HOWEVER...GIVEN POTENTIAL INSTABILITY...SEEMS PRUDENT TO MENTION AT LEAST SCT SHRA/TSRA THIS AFTN. A QUICK CHECK OF THE 06Z LOCAL HIGH RES WRF AND 4KM NAM ARE VERY SUPPORTIVE OF THIS IDEA AS THEY SHOW CONVECTION DEVELOPING ACROSS CNTRL UPPER MI EARLY THIS AFTN AND THEN SPREADING E. APPEARS THE AREA FROM ROUGHLY CRYSTAL FALLS TO ISHPEMING EASTWARD WILL HAVE THE POTENTIAL FOR SVR STORMS THIS AFTN. SVR POTENTIAL SHOULD BE LOWER TOWARD LAKE MICHIGAN ACROSS SE DELTA/SRN SCHOOLCRAFT COUNTIES WITH SRLY FLOW/MARINE INFLUENCE OFF THE LAKE. OTHER ITEM OF NOTE TODAY IS THE DRIER AIR MOVING INTO WRN UPPER MI BEHIND FRONT. SEVERAL PIECES OF GUIDANCE SUGGEST DWPTS FALLING INTO THE UPPER 40S WHICH RESULTS IN RH FALLING TO AROUND 30PCT THIS AFTN. WITH WINDS GUSTING TO 20-25MPH THIS AFTN...THERE WILL BE AN INCREASED RISK OF WILDFIRES WHERE SIGNIFICANT RAINFALL HAS NOT OCCURRED RECENTLY. .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 518 AM EDT MON JUN 11 2012 FOR THE START OF THE PERIOD 00Z TUE...A MID LEVEL SHORTWAVE TROUGH AXIS WILL BE FROM WRN HUDSON BAY TO CENTRAL MN...WITH A SFC LOW OVER CENTRAL NRN ONTARIO. A COLD FRONT/SFC TROUGH WILL STRETCH S TO CENTRAL UPPER MI BY 00Z TUE. SOME SHOWERS AND THUNDERSTORMS WILL BE ONGOING ALONG AND AHEAD OF THE COLD FRONT...BUT THE DRY SLOT WILL BE MOVING IN AROUND THIS TIME DURING LOSS OF DAYTIME HEATING. THERE IS A POSSIBILITY OF SOME ELEVATED CONVECTION LATE IN THE EVENING OR EARLY OVERNIGHT...BUT I THINK THE DRY AIR WILL KEEP THAT FROM HAPPENING. WILL DEPICT PRECIP WITH CHANCE POPS MOVING OUT OF THE CWA BY 06Z TUE. BY 12Z TUE...THE 500MB TROUGH AXIS WILL BE FROM ERN HUDSON BAY TO WRN LAKE SUPERIOR...WITH THE SFC LOW NEAR JAMES BAY AND SFC HIGH PRESSURE MOVING INTO WRN MN. THE COLD FRONT WILL BE E OF THE CWA...WITH GOOD CAA IN THE WNW LOW LEVEL FLOW OVER THE AREA. 850MB TEMPS WILL BE AROUND 3C E AND -1C W. BY 18Z TUE...THE 500MB TROUGH AXIS WILL BE OVER THE CENTER OF THE CWA...WITH THE SFC HIGH BEGINNING TO MOVE INTO THE WRN CWA. 850MB TEMPS AT 18Z WILL RANGE FROM -2C N TO 2C S. BY 00Z WED...THE 500MB TROUGH AXIS WILL BE OVER FAR ERN UPPER MI...WHILE THE SFC HIGH WILL BE OVER MOST OF THE CWA. MODEL SOUNDING SUGGEST MIXING TO AROUND 825MB TUE...RESULTING IN HIGHS IN THE 50S N TO 60S S...AND LOW DEW PTS. THE SFC HIGH WILL BE CENTERED OVER THE CWA TUE NIGHT...WHICH WILL LEAD TO FROST POTENTIAL AS COOL TEMPS TUE DROP QUICKLY UNDER MOSTLY CLEAR SKIES. WENT WITH THE LOW SIDE OF TEMP GUIDANCE...WITH MANY LOCATIONS OVER THE INTERIOR DROPPING NEAR OR BELOW FREEZING. WILL KEEP MENTION OF FROST IN HWO. WED THROUGH FRI...THE SFC HIGH MOVES E WHILE SFC LOW PRESSURE DEVELOPS WELL TO OUR W IN RESPONSE TO A SERIES OF SHORTWAVES. THE RESULTING SLY FLOW IN THE LOW LEVELS BRINGS OFF AND ON CONVECTION FROM LATE WED THROUGH FRI...BUT MODELS INDICATE MOST OF THAT STAYING W OF THE CWA AND INTO WRN LAKE SUPERIOR. WILL KEEP FORECAST FOR UPPER MI DRY THROUGH THIS PERIOD AS A DRIER PATTERN HAS VERIFIED BETTER RECENTLY...AND MOST MODELS KEEP US DRY ANYWAYS. AN UPPER RIDGE WILL BUILD INTO THE AREA FROM THE S...BRINGING STEADILY INCREASING TEMPS WED THROUGH AT LEAST FRI. BY FRI...850MB TEMPS SHOULD BE UP TO 16C...THEN UP TO 18C ON SAT AND SUN. MODELS DIVERGE ON SOLUTIONS FOR THE WEEKEND...WITH THE 12Z/10 ECMWF BRINGING A TROUGH PUSHING IN FROM THE NW...WHILE THE 00Z/11 GFS KEEPS THE UPPER RIDGE IN PLACE. USED A CONSENSUS OF MODELS FOR THE WEEKEND GIVEN LOW CONFIDENCE IN ANY PARTICULAR MODEL SOLUTION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 155 PM EDT MON JUN 11 2012 VFR CONDITIONS SHOULD PREVAIL INTO THE EVENING HRS AT KIWD/KCMX/KSAW. SCT -SHRA/-TSRA COULD FORM BTWN 18-00Z IN VCNTY OF KSAW ALONG INCOMING COLD FRONT BUT GIVEN CONSIDERABLE UNCERTAINTY IN PLACEMENT/COVERAGE OF AFTN CONVECTION DUE TO CLOUD COVER...SHRA/TSRA WERE NOT MENTIONED AT KSAW. WEST WINDS COULD BECOME GUSTY AND PICK UP SUBSTANTIALLY AT KIWD AND ESPECIALLY KCMX AS A SECONDARY COLD FRONT PASSES THRU THE AREA LATE AFTN/EVENING. LOOKING UPSTREAM...MVFR CIGS COULD DEVELOP OVERNIGHT AT KIWD AND KCMX AND THEN LATE TUE MORNING AT KSAW WITH PASSAGE OF SECONDARY COLD FRONT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 518 AM EDT MON JUN 11 2012 AHEAD OF A COLD FRONT...S WINDS WILL BE IN THE 15-25KT RANGE OVER ERN LAKE SUPERIOR TODAY...ESPECIALLY EARLY IN THE DAY. SOME OF THE HIGHER OBSERVING PLATFORMS WILL SEE WINDS TO AROUND 30KT. BEHIND THE COLD FRONT...A PUSH OF STRONGER WESTERLY WINDS TO 25-30KT WILL ARRIVE OVER WRN LAKE SUPERIOR MID/LATE AFTN. THESE STRONGER WINDS WILL THEN SPREAD ACROSS THE LAKE TONIGHT. LOOK FOR THE WINDS TO GRADUALLY DIMINISH FROM W TO E TUE WITH WINDS FALLING BLO 15KT TUE NIGHT AS HIGH PRES ARRIVES OVER THE UPPER LAKES. WINDS WED THRU FRI SHOULD BE UNDER 20KT AS PRES GRADIENT REMAINS RELATIVELY WEAK BTWN THE DEPARTING HIGH AND A LOW PRES TROF SETTING UP WELL TO THE W AND NW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
739 AM EDT MON JUN 11 2012 .SHORT TERM...(TODAY) ISSUED AT 518 AM EDT MON JUN 11 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A FAIRLY DEEP TROF MOVING ACROSS THE NRN PLAINS. AS EXPECTED DUE TO WEAKENING INSTABILITY... SHRA/TSRA THAT DEVELOPED YESTERDAY AFTN AHEAD OF COLD FRONT IN MN DIMINISHED AS THEY APPROACHED UPPER MI EARLIER IN THE NIGHT. HOWEVER...A LINGERING RIBBON OF MUCAPE WHICH HAS RECENTLY INCREASED TO 500-1000J/KG PER LATEST SPC MESOANALYSIS IS SUPPORTING SCT SHRA/TSRA WHICH ARE SPREADING/DEVELOPING NE INTO THE WRN FCST AREA AS OF 09Z. MAIN CONCERN IN THE SHORT TERM REVOLVES AROUND REDEVELOPMENT OF CONVECTION TODAY AS COLD FRONT DRIFTS ACROSS THE AREA. SHRA/TSRA SPREADING INTO WRN UPPER MI WILL PROBABLY PERSIST FOR THE NEXT FEW HRS GIVEN AVBL INSTABILITY. COLD FRONT SHOULD THEN CLEAR THE W BEFORE REDEVELOPMENT CAN OCCUR TODAY. TO THE E...DEBRIS CLOUDS FROM SHRA/TSRA WILL PROBABLY THIN OUT SUFFICIENTLY TO ALLOW FOR DECENT HEATING AHEAD OF THE COLD FRONT AS IT MOVES ACROSS CNTRL UPPER MI THIS AFTN. UTILIZING MODIFIED NAM FCST SOUNDINGS FOR T/TD OF MID 80S/LWR 60S PRIOR TO MODEL GENERATED PCPN (GFS SOUNDING CONTAMINATED BY PCPN) YIELDS SBCAPE IN THE 1000-1500J/KG RANGE. WITH DEEP LAYER SHEAR OF 30-40KT...THERE WILL BE THE POTENTIAL FOR ORGANIZED STORMS AND SVR WX. HIGH RES MODELS GIVE CONFLICTING SIGNALS ABOUT WHETHER CONVECTION WILL REDVELOP AS SEVERAL INDICATE LITTLE OR NO REGENERATION TODAY. HOWEVER...GIVEN POTENTIAL INSTABILITY...SEEMS PRUDENT TO MENTION AT LEAST SCT SHRA/TSRA THIS AFTN. A QUICK CHECK OF THE 06Z LOCAL HIGH RES WRF AND 4KM NAM ARE VERY SUPPORTIVE OF THIS IDEA AS THEY SHOW CONVECTION DEVELOPING ACROSS CNTRL UPPER MI EARLY THIS AFTN AND THEN SPREADING E. APPEARS THE AREA FROM ROUGHLY CRYSTAL FALLS TO ISHPEMING EASTWARD WILL HAVE THE POTENTIAL FOR SVR STORMS THIS AFTN. SVR POTENTIAL SHOULD BE LOWER TOWARD LAKE MICHIGAN ACROSS SE DELTA/SRN SCHOOLCRAFT COUNTIES WITH SRLY FLOW/MARINE INFLUENCE OFF THE LAKE. OTHER ITEM OF NOTE TODAY IS THE DRIER AIR MOVING INTO WRN UPPER MI BEHIND FRONT. SEVERAL PIECES OF GUIDANCE SUGGEST DWPTS FALLING INTO THE UPPER 40S WHICH RESULTS IN RH FALLING TO AROUND 30PCT THIS AFTN. WITH WINDS GUSTING TO 20-25MPH THIS AFTN...THERE WILL BE AN INCREASED RISK OF WILDFIRES WHERE SIGNIFICANT RAINFALL HAS NOT OCCURRED RECENTLY. .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 518 AM EDT MON JUN 11 2012 FOR THE START OF THE PERIOD 00Z TUE...A MID LEVEL SHORTWAVE TROUGH AXIS WILL BE FROM WRN HUDSON BAY TO CENTRAL MN...WITH A SFC LOW OVER CENTRAL NRN ONTARIO. A COLD FRONT/SFC TROUGH WILL STRETCH S TO CENTRAL UPPER MI BY 00Z TUE. SOME SHOWERS AND THUNDERSTORMS WILL BE ONGOING ALONG AND AHEAD OF THE COLD FRONT...BUT THE DRY SLOT WILL BE MOVING IN AROUND THIS TIME DURING LOSS OF DAYTIME HEATING. THERE IS A POSSIBILITY OF SOME ELEVATED CONVECTION LATE IN THE EVENING OR EARLY OVERNIGHT...BUT I THINK THE DRY AIR WILL KEEP THAT FROM HAPPENING. WILL DEPICT PRECIP WITH CHANCE POPS MOVING OUT OF THE CWA BY 06Z TUE. BY 12Z TUE...THE 500MB TROUGH AXIS WILL BE FROM ERN HUDSON BAY TO WRN LAKE SUPERIOR...WITH THE SFC LOW NEAR JAMES BAY AND SFC HIGH PRESSURE MOVING INTO WRN MN. THE COLD FRONT WILL BE E OF THE CWA...WITH GOOD CAA IN THE WNW LOW LEVEL FLOW OVER THE AREA. 850MB TEMPS WILL BE AROUND 3C E AND -1C W. BY 18Z TUE...THE 500MB TROUGH AXIS WILL BE OVER THE CENTER OF THE CWA...WITH THE SFC HIGH BEGINNING TO MOVE INTO THE WRN CWA. 850MB TEMPS AT 18Z WILL RANGE FROM -2C N TO 2C S. BY 00Z WED...THE 500MB TROUGH AXIS WILL BE OVER FAR ERN UPPER MI...WHILE THE SFC HIGH WILL BE OVER MOST OF THE CWA. MODEL SOUNDING SUGGEST MIXING TO AROUND 825MB TUE...RESULTING IN HIGHS IN THE 50S N TO 60S S...AND LOW DEW PTS. THE SFC HIGH WILL BE CENTERED OVER THE CWA TUE NIGHT...WHICH WILL LEAD TO FROST POTENTIAL AS COOL TEMPS TUE DROP QUICKLY UNDER MOSTLY CLEAR SKIES. WENT WITH THE LOW SIDE OF TEMP GUIDANCE...WITH MANY LOCATIONS OVER THE INTERIOR DROPPING NEAR OR BELOW FREEZING. WILL KEEP MENTION OF FROST IN HWO. WED THROUGH FRI...THE SFC HIGH MOVES E WHILE SFC LOW PRESSURE DEVELOPS WELL TO OUR W IN RESPONSE TO A SERIES OF SHORTWAVES. THE RESULTING SLY FLOW IN THE LOW LEVELS BRINGS OFF AND ON CONVECTION FROM LATE WED THROUGH FRI...BUT MODELS INDICATE MOST OF THAT STAYING W OF THE CWA AND INTO WRN LAKE SUPERIOR. WILL KEEP FORECAST FOR UPPER MI DRY THROUGH THIS PERIOD AS A DRIER PATTERN HAS VERIFIED BETTER RECENTLY...AND MOST MODELS KEEP US DRY ANYWAYS. AN UPPER RIDGE WILL BUILD INTO THE AREA FROM THE S...BRINGING STEADILY INCREASING TEMPS WED THROUGH AT LEAST FRI. BY FRI...850MB TEMPS SHOULD BE UP TO 16C...THEN UP TO 18C ON SAT AND SUN. MODELS DIVERGE ON SOLUTIONS FOR THE WEEKEND...WITH THE 12Z/10 ECMWF BRINGING A TROUGH PUSHING IN FROM THE NW...WHILE THE 00Z/11 GFS KEEPS THE UPPER RIDGE IN PLACE. USED A CONSENSUS OF MODELS FOR THE WEEKEND GIVEN LOW CONFIDENCE IN ANY PARTICULAR MODEL SOLUTION. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 739 AM EDT MON JUN 11 2012 VFR CONDITIONS SHOULD PREVAIL THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW. NARROW BAND OF SCT -SHRA/-TSRA PER CURRENT KMQT RADAR IMAGERY WILL LIKELY AFFECT KSAW UNTIL AROUND 14Z. OTHERWISE...AS COLD FRONT SLOWLY MOVES ACROSS THE AREA TODAY... POTENTIAL IS THERE FOR SHRA/TSRA TO REDEVELOP OVER CNTRL UPPER MI THIS AFTN. WITH CONSIDERABLE UNCERTAINTY IN PLACEMENT/COVERAGE OF ANY AFTN CONVECTION...SHRA/TSRA WERE NOT MENTIONED AT KSAW. WEST WINDS COULD BECOME GUSTY AND PICK UP SUBSTANTIALLY AT KIWD AND ESPECIALLY KCMX AS A SECONDARY COLD FRONT PASSES THRU THE AREA LATE AFTN/EVENING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 518 AM EDT MON JUN 11 2012 AHEAD OF A COLD FRONT...S WINDS WILL BE IN THE 15-25KT RANGE OVER ERN LAKE SUPERIOR TODAY...ESPECIALLY EARLY IN THE DAY. SOME OF THE HIGHER OBSERVING PLATFORMS WILL SEE WINDS TO AROUND 30KT. BEHIND THE COLD FRONT...A PUSH OF STRONGER WESTERLY WINDS TO 25-30KT WILL ARRIVE OVER WRN LAKE SUPERIOR MID/LATE AFTN. THESE STRONGER WINDS WILL THEN SPREAD ACROSS THE LAKE TONIGHT. LOOK FOR THE WINDS TO GRADUALLY DIMINISH FROM W TO E TUE WITH WINDS FALLING BLO 15KT TUE NIGHT AS HIGH PRES ARRIVES OVER THE UPPER LAKES. WINDS WED THRU FRI SHOULD BE UNDER 20KT AS PRES GRADIENT REMAINS RELATIVELY WEAK BTWN THE DEPARTING HIGH AND A LOW PRES TROF SETTING UP WELL TO THE W AND NW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
532 AM EDT MON JUN 11 2012 .SHORT TERM...(TODAY) ISSUED AT 518 AM EDT MON JUN 11 2012 WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A FAIRLY DEEP TROF MOVING ACROSS THE NRN PLAINS. AS EXPECTED DUE TO WEAKENING INSTABILITY... SHRA/TSRA THAT DEVELOPED YESTERDAY AFTN AHEAD OF COLD FRONT IN MN DIMINISHED AS THEY APPROACHED UPPER MI EARLIER IN THE NIGHT. HOWEVER...A LINGERING RIBBON OF MUCAPE WHICH HAS RECENTLY INCREASED TO 500-1000J/KG PER LATEST SPC MESOANALYSIS IS SUPPORTING SCT SHRA/TSRA WHICH ARE SPREADING/DEVELOPING NE INTO THE WRN FCST AREA AS OF 09Z. MAIN CONCERN IN THE SHORT TERM REVOLVES AROUND REDEVELOPMENT OF CONVECTION TODAY AS COLD FRONT DRIFTS ACROSS THE AREA. SHRA/TSRA SPREADING INTO WRN UPPER MI WILL PROBABLY PERSIST FOR THE NEXT FEW HRS GIVEN AVBL INSTABILITY. COLD FRONT SHOULD THEN CLEAR THE W BEFORE REDEVELOPMENT CAN OCCUR TODAY. TO THE E...DEBRIS CLOUDS FROM SHRA/TSRA WILL PROBABLY THIN OUT SUFFICIENTLY TO ALLOW FOR DECENT HEATING AHEAD OF THE COLD FRONT AS IT MOVES ACROSS CNTRL UPPER MI THIS AFTN. UTILIZING MODIFIED NAM FCST SOUNDINGS FOR T/TD OF MID 80S/LWR 60S PRIOR TO MODEL GENERATED PCPN (GFS SOUNDING CONTAMINATED BY PCPN) YIELDS SBCAPE IN THE 1000-1500J/KG RANGE. WITH DEEP LAYER SHEAR OF 30-40KT...THERE WILL BE THE POTENTIAL FOR ORGANIZED STORMS AND SVR WX. HIGH RES MODELS GIVE CONFLICTING SIGNALS ABOUT WHETHER CONVECTION WILL REDVELOP AS SEVERAL INDICATE LITTLE OR NO REGENERATION TODAY. HOWEVER...GIVEN POTENTIAL INSTABILITY...SEEMS PRUDENT TO MENTION AT LEAST SCT SHRA/TSRA THIS AFTN. A QUICK CHECK OF THE 06Z LOCAL HIGH RES WRF AND 4KM NAM ARE VERY SUPPORTIVE OF THIS IDEA AS THEY SHOW CONVECTION DEVELOPING ACROSS CNTRL UPPER MI EARLY THIS AFTN AND THEN SPREADING E. APPEARS THE AREA FROM ROUGHLY CRYSTAL FALLS TO ISHPEMING EASTWARD WILL HAVE THE POTENTIAL FOR SVR STORMS THIS AFTN. SVR POTENTIAL SHOULD BE LOWER TOWARD LAKE MICHIGAN ACROSS SE DELTA/SRN SCHOOLCRAFT COUNTIES WITH SRLY FLOW/MARINE INFLUENCE OFF THE LAKE. OTHER ITEM OF NOTE TODAY IS THE DRIER AIR MOVING INTO WRN UPPER MI BEHIND FRONT. SEVERAL PIECES OF GUIDANCE SUGGEST DWPTS FALLING INTO THE UPPER 40S WHICH RESULTS IN RH FALLING TO AROUND 30PCT THIS AFTN. WITH WINDS GUSTING TO 20-25MPH THIS AFTN...THERE WILL BE AN INCREASED RISK OF WILDFIRES WHERE SIGNIFICANT RAINFALL HAS NOT OCCURRED RECENTLY. .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 518 AM EDT MON JUN 11 2012 FOR THE START OF THE PERIOD 00Z TUE...A MID LEVEL SHORTWAVE TROUGH AXIS WILL BE FROM WRN HUDSON BAY TO CENTRAL MN...WITH A SFC LOW OVER CENTRAL NRN ONTARIO. A COLD FRONT/SFC TROUGH WILL STRETCH S TO CENTRAL UPPER MI BY 00Z TUE. SOME SHOWERS AND THUNDERSTORMS WILL BE ONGOING ALONG AND AHEAD OF THE COLD FRONT...BUT THE DRY SLOT WILL BE MOVING IN AROUND THIS TIME DURING LOSS OF DAYTIME HEATING. THERE IS A POSSIBILITY OF SOME ELEVATED CONVECTION LATE IN THE EVENING OR EARLY OVERNIGHT...BUT I THINK THE DRY AIR WILL KEEP THAT FROM HAPPENING. WILL DEPICT PRECIP WITH CHANCE POPS MOVING OUT OF THE CWA BY 06Z TUE. BY 12Z TUE...THE 500MB TROUGH AXIS WILL BE FROM ERN HUDSON BAY TO WRN LAKE SUPERIOR...WITH THE SFC LOW NEAR JAMES BAY AND SFC HIGH PRESSURE MOVING INTO WRN MN. THE COLD FRONT WILL BE E OF THE CWA...WITH GOOD CAA IN THE WNW LOW LEVEL FLOW OVER THE AREA. 850MB TEMPS WILL BE AROUND 3C E AND -1C W. BY 18Z TUE...THE 500MB TROUGH AXIS WILL BE OVER THE CENTER OF THE CWA...WITH THE SFC HIGH BEGINNING TO MOVE INTO THE WRN CWA. 850MB TEMPS AT 18Z WILL RANGE FROM -2C N TO 2C S. BY 00Z WED...THE 500MB TROUGH AXIS WILL BE OVER FAR ERN UPPER MI...WHILE THE SFC HIGH WILL BE OVER MOST OF THE CWA. MODEL SOUNDING SUGGEST MIXING TO AROUND 825MB TUE...RESULTING IN HIGHS IN THE 50S N TO 60S S...AND LOW DEW PTS. THE SFC HIGH WILL BE CENTERED OVER THE CWA TUE NIGHT...WHICH WILL LEAD TO FROST POTENTIAL AS COOL TEMPS TUE DROP QUICKLY UNDER MOSTLY CLEAR SKIES. WENT WITH THE LOW SIDE OF TEMP GUIDANCE...WITH MANY LOCATIONS OVER THE INTERIOR DROPPING NEAR OR BELOW FREEZING. WILL KEEP MENTION OF FROST IN HWO. WED THROUGH FRI...THE SFC HIGH MOVES E WHILE SFC LOW PRESSURE DEVELOPS WELL TO OUR W IN RESPONSE TO A SERIES OF SHORTWAVES. THE RESULTING SLY FLOW IN THE LOW LEVELS BRINGS OFF AND ON CONVECTION FROM LATE WED THROUGH FRI...BUT MODELS INDICATE MOST OF THAT STAYING W OF THE CWA AND INTO WRN LAKE SUPERIOR. WILL KEEP FORECAST FOR UPPER MI DRY THROUGH THIS PERIOD AS A DRIER PATTERN HAS VERIFIED BETTER RECENTLY...AND MOST MODELS KEEP US DRY ANYWAYS. AN UPPER RIDGE WILL BUILD INTO THE AREA FROM THE S...BRINGING STEADILY INCREASING TEMPS WED THROUGH AT LEAST FRI. BY FRI...850MB TEMPS SHOULD BE UP TO 16C...THEN UP TO 18C ON SAT AND SUN. MODELS DIVERGE ON SOLUTIONS FOR THE WEEKEND...WITH THE 12Z/10 ECMWF BRINGING A TROUGH PUSHING IN FROM THE NW...WHILE THE 00Z/11 GFS KEEPS THE UPPER RIDGE IN PLACE. USED A CONSENSUS OF MODELS FOR THE WEEKEND GIVEN LOW CONFIDENCE IN ANY PARTICULAR MODEL SOLUTION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 136 AM EDT MON JUN 11 2012 EXPECT MAINLY VFR CONDITIONS THROUGH THE FCST PERIOD. HOWEVER...THERE MAY BE PERIOD OF MVFR CIGS AT KIWD EARLY THIS MORNING ASSOCIATED WITH LOW LEVEL MOISTURE BEHIND A COLD FRONT MOVING INTO WRN UPPER MI. IN ADDITION...EXPECT LLWS OVERNIGHT WITH A LOW LEVEL JET AHEAD OF THE COLD FRONT. SCT -SHRA ARE POSSIBLE AS THE FRONT MOVES THROUGH BUT CONFIDENCE IS ONLY MARGINAL THAT ANY TSRA WILL OCCUR SO WERE NOT INCLUDED AT THIS TIME. BY MID TO LATE MORNING...CLOUDS CLEAR OUT AS DRY AIR MOVES IN. WEST WINDS COULD BECOMING GUSTY AND PICK UP SUBSTANTIALLY AT KCMX AND KIWD BY EVENING AS A SECONDARY COLD FRONT MOVES THROUGH. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 518 AM EDT MON JUN 11 2012 AHEAD OF A COLD FRONT...S WINDS WILL BE IN THE 15-25KT RANGE OVER ERN LAKE SUPERIOR TODAY...ESPECIALLY EARLY IN THE DAY. SOME OF THE HIGHER OBSERVING PLATFORMS WILL SEE WINDS TO AROUND 30KT. BEHIND THE COLD FRONT...A PUSH OF STRONGER WESTERLY WINDS TO 25-30KT WILL ARRIVE OVER WRN LAKE SUPERIOR MID/LATE AFTN. THESE STRONGER WINDS WILL THEN SPREAD ACROSS THE LAKE TONIGHT. LOOK FOR THE WINDS TO GRADUALLY DIMINISH FROM W TO E TUE WITH WINDS FALLING BLO 15KT TUE NIGHT AS HIGH PRES ARRIVES OVER THE UPPER LAKES. WINDS WED THRU FRI SHOULD BE UNDER 20KT AS PRES GRADIENT REMAINS RELATIVELY WEAK BTWN THE DEPARTING HIGH AND A LOW PRES TROF SETTING UP WELL TO THE W AND NW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...JLB MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
659 AM CDT MON JUN 11 2012 .UPDATE... 12Z AVIATION DISCUSSION ADDED BELOW. && .DISCUSSION... SHORTWAVE TROUGH CENTERED OVER LAKE WINNIPEG CANADA WILL CONTINUE TO LIFT NORTHEAST OVER THE UPPER GREAT LAKES TODAY. COLD POOL ALOFT ASSOCIATED WITH THE UPPER LEVEL LOW PRESSURE SYSTEM ALONG WITH ANY DAYTIME HEATING COULD GENERATE ISOLATED SHOWERS OVER THE FAR NORTHERN SECTION OF OUR FORECAST AREA LATE MORNING THROUGH MID AFTERNOON. ELSEWHERE...DRIER AIR WILL CONTINUE TO FILTER IN THROUGH TUESDAY. HIGHS TODAY WILL BE MUCH COOLER THAN PREVIOUS COUPLE OF DAYS WITH READINGS MAINLY IN THE 70S. HIGH PRESSURE WILL BEGIN TO BUILD OVER THE NORTHERN PLAINS THIS AFTERNOON AND OVER THE WESTERN GREAT LAKES AREA LATER TONIGHT AND TUESDAY. OVERNIGHT LOWS TONIGHT WILL COOL DOWN INTO THE 40S TO LOWER 50S. HIGHS ON TUESDAY WILL WARM BACK INTO THE UPPER 60S AND LOWER 70S. MEDIUM RANGE MODELS HAVE BEEN CONSISTENT WITH NEXT SHORTWAVE TROUGH FORECAST TO MOVE INTO THE UPPER MIDWEST WEDNESDAY NIGHT AND THURSDAY AS THE UPPER AIRFLOW BECOMES MORE ZONAL ACROSS THE NORTHERN TIER OF CONUS. WL KEEP SOME POPS GOING THROUGH THE REST OF THE WORK WEEK. UPPER HIGH PRESSURE RIDGE OVER THE EASTERN CONUS WILL RETROGRESS BACK WEST OVER THE MIDWEST BY THE END OF THE WORK WEEK AND WEEKEND. THE LATEST LONG TERM MODELS INDICATE A SPLIT UPPER AIR FLOW OVER THE UPPER MIDWEST. ECMWF MODEL KEEPS MUCH OF THE PRECIPITATION OVER NORTHERN HALF OF THE STATE. UPPER RIDGE WILL BRING MUCH OF THE EASTERN FORECAST AREA DRY CONDITIONS ALONG WITH MAX TEMPERATURES MODERATING INTO THE UPPER 80S. && .AVIATION.../12Z TAF ISSUANCE/ A FEW LINGERING IFR/MVFR CONDITIONS OVER WRN WI WILL QUICKLY GET PUSHED OUT BY DRIER AIR FROM THE WEST...WITH VFR CONDITIONS DOMINATING THIS TAF PERIOD. A SECONDARY BOUNDARY IS WORKING INTO WRN MN RIGHT NOW AND WILL WORK ACROSS MN THIS MORNING AND THROUGH EAU BY THE EARLY AFTERNOON. WINDS WILL BE SW OUT AHEAD OF THIS BOUNDARY...AND SWITCH TO THE W BEHIND WHILE ALSO PICKING UP IN STRENGTH. STRONGEST WINDS WILL BE OVER NW MN...BUT A FEW GUSTS AOA 30 KTS WILL BE POSSIBLE AT MAINLY AXN THIS AFTERNOON. FOR SHOWERS...THE RAP SHOWS SOME INSTABILITY DEVELOPING AHEAD OF THE BOUNDARY BY THE AFTERNOON...WITH THE HRRR GENERATING A LINE OF SHRA AS A RESULT. THE HRRR HAS BEEN DEVELOPING THESE SHOWERS FURTHER EAST WITH EACH SUCCESSIVE RUN...AND WHAT WAS NEAR MSP WITH THE 04Z RUN IS NOW NOT GETTING GENERATED UNTIL EAST OF EAU...WHICH IS WERE HIGHEST RISK OF FOR A BRIEF SHRA WILL EXIST. OTHERWISE...BKN CU FIELD AROUND 5K FT IS EXPECTED BY THE AFTERNOON DOWN TO THE TWIN CITIES...WITH A BRIEF MVFR CIG POSSIBLE AT AXN BETWEEN 14 AND 16Z. KMSP...FAVORED TAF WIND DIRECTIONS TOWARD THAT OF THE HRRR...WITH WINDS EXPECTED TO VEER TO THE WEST BY THE AFTERNOON. DO NOT EXPECT WINDS TO BE CONSISTENTLY NORTH OF 240 UNTIL AFTER 15Z...SO THERE COULD BE A FEW ISSUES WITH HAVING THE AIRPORT ON THE 30S HERE IN THE FIRST COUPLE OF HOURS. AFTER THAT...DO EXPECT BKN CIGS...BUT CAPPING INVERSION LOOKS TO BE LOW ENOUGH THIS AFTERNOON TO LIMIT ANY SHOWER POTENTIAL. ALSO...BASED ON WINDS ACROSS THE DAKOTAS ALL NIGHT...LOOKS GOOD TO SEE ANOTHER DAY OF GUSTS UP TO AROUND 30 KTS...EXCEPT THIS TIME WITH A WEST WIND. WILL SEE LIGHTER WINDS TUESDAY AS HIGH PRESSURE MOVES THROUGH. OUTLOOK... .TUE...VFR/SKC. WINDS NW 5-10 KTS. .WED...VFR WITH BRIEF PERIODS OF MVFR WITH SCTD SHRA/TSRA. WINDS S 10-15 KTS. .THU...CHC SHRA/TSRA. VFR...EXCEPT MVFR WITH ANY SHRA/TSRA. WINDS S AROUND 10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JVM/MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1220 PM CDT Mon Jun 11 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... Short Term (Tonight-Wednesday) Overnight, the focus was on two lines of convection: the leading line being the advancing gust front and the second line being focused along the cold front. The showers and thunderstorms along the gust front continued to weaken through the overnight hours, with the bit of remnant activity tracking southeast of the Missouri River by 09Z. The better area of convective activity was focused along the cold front that was stretching roughly along a line from North Kansas City to Cameron and Bethany around 09Z. The activity was remaining well below severe limits with 1000-1500 J/kg MUCAPE, weak shear, and poor lapse rates present. This line of thunderstorms had been fairly slow-moving, but has become a bit more progressive toward the southeast with the help of 20-25kt 850mb winds. This slow tracking was resulting in higher rainfall rates across extreme northeast Kansas and northwest Missouri, with some locations likely accumulating more than one inch of rain within an hour. HRRR shows the line of thunderstorms stretching along a Kansas City to Chillicothe line by around 10Z, progressing just south of the Missouri River by around 13Z. Short range models are in fairly good agreement that this thunderstorm activity will shift southeast of the forecast area late this morning, but cannot rule out a few lingering showers and thunderstorms across central Missouri early this afternoon. Winds will shift to the northwest behind the advancing cold front. However, cold air advection behind the cold front will be limited today so should see afternoon temperatures still warmer than normal -- into the middle 80s. High pressure will build in across the Northern and Central Plains later this afternoon and track toward the Great Lakes region by the middle of the week, keeping conditions dry. Temperatures look to be near to slightly above seasonal normals through Wednesday as winds shift from northeast to southeast with the eastward-moving surface high. As the upper level trough over the Northern Plains progresses toward the northern Great Lakes, a more zonal flow will set up across the western and central CONUS through mid-week. Models have shown the potential for a few disturbances to develop within the zonal flow primarily west of the forecast area across Kansas. Confidence is low in whether or not any of these impulses will spread enough eastward to clip eastern Kansas and extreme western Missouri Wednesday and Wednesday night, so have nothing more than slight chance pops in for that area. ACH Medium Range (Thursday through Sunday)... Prefer a wait and see approach as it relates to rain chances during the medium range period. The 00z ECMWF and GFS build mid level heights, with the ECMWF developing a closed high, across the mid MO River Valley while a western U.S. trough builds. While it`s certainly possible a weak vorticity lobe or two will meander across the Central Plains Thursday or Friday within a chaotic and weak westerly flow coming out of the Rockies, confidence is low on just how much convection, if any can make it into the CWA. Agree with the previous discussion in favoring the drier ECMWF over the relatively wet GFS. As such can only justify slight chance pops until the end late Sunday when falling heights across the Plains in response to the approaching upper trough offers some hope that increasing dynamics will generate some scattered convection. A gradual warm up on temperatures and dewpoints continues to look in order with readings in the upper 80s/90 by the weekend. MJ && .AVIATION... For the 18z TAFs: Secondary cold front beginning to push through the terminals early this afternoon will allow drier air to filter southward. Scattered strato-cu deck behind this front and ahead of 850 trough will persist into the afternoon hours. Skies will clear by this evening and remain VFR though the overnight period. Will need to monitor for the potential of fog development near daybreak at the terminals as winds turn light. Recent rainfall combined with these light winds may support development, but advection of drier air from the northwest will also inhibit development. Dux && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
633 AM CDT Mon Jun 11 2012 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... Short Term (Tonight-Wednesday) Overnight, the focus was on two lines of convection: the leading line being the advancing gust front and the second line being focused along the cold front. The showers and thunderstorms along the gust front continued to weaken through the overnight hours, with the bit of remnant activity tracking southeast of the Missouri River by 09Z. The better area of convective activity was focused along the cold front that was stretching roughly along a line from North Kansas City to Cameron and Bethany around 09Z. The activity was remaining well below severe limits with 1000-1500 J/kg MUCAPE, weak shear, and poor lapse rates present. This line of thunderstorms had been fairly slow-moving, but has become a bit more progressive toward the southeast with the help of 20-25kt 850mb winds. This slow tracking was resulting in higher rainfall rates across extreme northeast Kansas and northwest Missouri, with some locations likely accumulating more than one inch of rain within an hour. HRRR shows the line of thunderstorms stretching along a Kansas City to Chillicothe line by around 10Z, progressing just south of the Missouri River by around 13Z. Short range models are in fairly good agreement that this thunderstorm activity will shift southeast of the forecast area late this morning, but cannot rule out a few lingering showers and thunderstorms across central Missouri early this afternoon. Winds will shift to the northwest behind the advancing cold front. However, cold air advection behind the cold front will be limited today so should see afternoon temperatures still warmer than normal -- into the middle 80s. High pressure will build in across the Northern and Central Plains later this afternoon and track toward the Great Lakes region by the middle of the week, keeping conditions dry. Temperatures look to be near to slightly above seasonal normals through Wednesday as winds shift from northeast to southeast with the eastward-moving surface high. As the upper level trough over the Northern Plains progresses toward the northern Great Lakes, a more zonal flow will set up across the western and central CONUS through mid-week. Models have shown the potential for a few disturbances to develop within the zonal flow primarily west of the forecast area across Kansas. Confidence is low in whether or not any of these impulses will spread enough eastward to clip eastern Kansas and extreme western Missouri Wednesday and Wednesday night, so have nothing more than slight chance pops in for that area. ACH Medium Range (Thursday through Sunday)... Prefer a wait and see approach as it relates to rain chances during the medium range period. The 00z ECMWF and GFS build mid level heights, with the ECMWF developing a closed high, across the mid MO River Valley while a western U.S. trough builds. While it`s certainly possible a weak vorticity lobe or two will meander across the Central Plains Thursday or Friday within a chaotic and weak westerly flow coming out of the Rockies, confidence is low on just how much convection, if any can make it into the CWA. Agree with the previous discussion in favoring the drier ECMWF over the relatively wet GFS. As such can only justify slight chance pops until the end late Sunday when falling heights across the Plains in response to the approaching upper trough offers some hope that increasing dynamics will generate some scattered convection. A gradual warm up on temperatures and dewpoints continues to look in order with readings in the upper 80s/90 by the weekend. MJ && .AVIATION... For the 12Z TAFs, the showers and thunderstorms that have developed along the cold front will continue to track southeastward through central and into southern Missouri this morning. Winds will shift to the northwest behind this passing front with dry conditions expected for the remainder of the period as high pressure begins to settle into the Northern and Central Plains. Some scattered mid-level clouds are possible through the day before clearing out by later this afternoon. ACH && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
411 AM CDT Mon Jun 11 2012 .DISCUSSION... Short Term (Tonight-Wednesday) Overnight, the focus was on two lines of convection: the leading line being the advancing gust front and the second line being focused along the cold front. The showers and thunderstorms along the gust front continued to weaken through the overnight hours, with the bit of remnant activity tracking southeast of the Missouri River by 09Z. The better area of convective activity was focused along the cold front that was stretching roughly along a line from North Kansas City to Cameron and Bethany around 09Z. The activity was remaining well below severe limits with 1000-1500 J/kg MUCAPE, weak shear, and poor lapse rates present. This line of thunderstorms had been fairly slow-moving, but has become a bit more progressive toward the southeast with the help of 20-25kt 850mb winds. This slow tracking was resulting in higher rainfall rates across extreme northeast Kansas and northwest Missouri, with some locations likely accumulating more than one inch of rain within an hour. HRRR shows the line of thunderstorms stretching along a Kansas City to Chillicothe line by around 10Z, progressing just south of the Missouri River by around 13Z. Short range models are in fairly good agreement that this thunderstorm activity will shift southeast of the forecast area late this morning, but cannot rule out a few lingering showers and thunderstorms across central Missouri early this afternoon. Winds will shift to the northwest behind the advancing cold front. However, cold air advection behind the cold front will be limited today so should see afternoon temperatures still warmer than normal -- into the middle 80s. High pressure will build in across the Northern and Central Plains later this afternoon and track toward the Great Lakes region by the middle of the week, keeping conditions dry. Temperatures look to be near to slightly above seasonal normals through Wednesday as winds shift from northeast to southeast with the eastward-moving surface high. As the upper level trough over the Northern Plains progresses toward the northern Great Lakes, a more zonal flow will set up across the western and central CONUS through mid-week. Models have shown the potential for a few disturbances to develop within the zonal flow primarily west of the forecast area across Kansas. Confidence is low in whether or not any of these impulses will spread enough eastward to clip eastern Kansas and extreme western Missouri Wednesday and Wednesday night, so have nothing more than slight chance pops in for that area. ACH Medium Range (Thursday through Sunday)... Prefer a wait and see approach as it relates to rain chances during the medium range period. The 00z ECMWF and GFS build mid level heights, with the ECMWF developing a closed high, across the mid MO River Valley while a western U.S. trough builds. While it`s certainly possible a weak vorticity lobe or two will meander across the Central Plains Thursday or Friday within a chaotic and weak westerly flow coming out of the Rockies, confidence is low on just how much convection, if any can make it into the CWA. Agree with the previous discussion in favoring the drier ECMWF over the relatively wet GFS. As such can only justify slight chance pops until the end late Sunday when falling heights across the Plains in response to the approaching upper trough offers some hope that increasing dynamics will generate some scattered convection. A gradual warm up on temperatures and dewpoints continues to look in order with readings in the upper 80s/90 by the weekend. MJ && .AVIATION... Convection percolating along and behind front will continue for the next few hours over the terminals as the front lays out more east west. Shear is weak and gust front getting out ahead will keep storms below severe levels but as new elevated storms develop the terminals will be in and out of MVFR until around daybreak. Adolphson && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ WFO EAX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1159 PM CDT SUN JUN 10 2012 .UPDATE... ISSUED AT 1037 PM CDT SUN JUN 10 2012 ISSUED AT 651 PM CDT SUN JUN 10 2012 MADE SOME MINOR CHANGES TO THE POPS FORECAST FOR EAST CENTRAL MISSOURI CONCERNING THE TIMING OF THE CHANCE FOR POPS. SLIGHTLY DELAYED TO POPS ARRIVAL OVER EAST CENTRAL MISSOOURI. STRONG CAP CONTINUES OVER CENTRAL THROUGH SOUTHEAST AND EAST CENTRAL KANSAS AT THIS TIME. STILL BELIEVE THAT THE LOCAL LSX WRF AND HRRR IN SOME FORM HAS THE BEST SOLUTIONS COMPARED TO THE NSSL-NCEP WRF MODEL. HRRR APPEARS TO BE TO SHOW VERY STRONG REFELCTVITY ORGANIZATION WHICH MIGHT BE SUSPECT GIVEN THE EVENING ENVIRONMENT. LIKE THE LOCAL WRF THE BEST. STILL BELIEVE MUCH OF THE PRECIPITATION WILL REMAIN GENERALLY ALONG AND NORTH OF I-70. AS CONVECTION GENERALLY MOVES ACROSS THE NORTHERN HALF OF MISSOURI IT WILL HAVE SOME PROBLEMS MAINTAIN LINE STRUCTURE DUE TO WEAK VERTICAL SHEAR. ALSO WOULD LIKE TO SEE HIGHER CAPE VALUES FOR THIS TIME OF THE YEAR FOR A DYNAMIC SYSTEM TO EVOLVE. COMPARING CURRENT CASE TO PREVIOUS LINE CASES THIS EVENING. LINE-TO WEAK BROAD BOWING REFLECTIVITY STRUCTURE WILL FURTHER WEAKEN AS CONVECTIVE SYSTEM MOVES INTO EXTREME NORTHEAST MISSOURI AND EAST CENTRAL SECTIONS OF THE STATE BY 11 TO 13 UTC. PRZYBYLINSKI .SHORT TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (TONIGHT) ISO-SCT SHRA/TSRA MAY CLIP THE SERN CWA LATE THIS AFTN BUT THE BULK OF ANY PCPN SHOULD REMAIN CLOSER TO THE MID-LEVEL LOW OVER AR/LA/MS AS IT LIFTS INTO THE TN VALLEY. ADDITIONAL SCT TSRA ARE EXPECTED TO DEVELOP LATE TONIGHT ALONG A TRAILING COLD FRONT AS IT SINKS SEWD FROM THE PLAINS TOWARDS THE CWA. PCPN MAY NOT BE VERY WIDESPREAD GIVEN THE LIMITED DYNAMICS AND LACK OF UPPER LEVEL SUPPORT. KANOFSKY && .SHORT TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (TONIGHT) ISO-SCT SHRA/TSRA MAY CLIP THE SERN CWA LATE THIS AFTN BUT THE BULK OF ANY PCPN SHOULD REMAIN CLOSER TO THE MID-LEVEL LOW OVER AR/LA/MS AS IT LIFTS INTO THE TN VALLEY. ADDITIONAL SCT TSRA ARE EXPECTED TO DEVELOP LATE TONIGHT ALONG A TRAILING COLD FRONT AS IT SINKS SEWD FROM THE PLAINS TOWARDS THE CWA. PCPN MAY NOT BE VERY WIDESPREAD GIVEN THE LIMITED DYNAMICS AND LACK OF UPPER LEVEL SUPPORT. KANOFSKY && .LONG TERM... ISSUED AT 325 PM CDT SUN JUN 10 2012 (MONDAY THROUGH NEXT SUNDAY) UPPER LEVEL RIDGE WILL GET SUPPRESSED BY MONDAY AS A STRONG SHORTWAVE PASSES TO OUR N...AND WILL RESULT IN ZONAL FLOW UNTIL THURSDAY. AT THE SFC...A CDFNT WILL PUSH THRU MAINLY ON MONDAY AFTERNOON AND EVENING WITH HI PRES THEN DOMINATING THE REGION TUESDAY THRU WEDNESDAY NIGHT. MONDAY STILL LOOKS OUR BEST CHC FOR PCPN OVER THE NEXT WEEK... AND EVEN THEN...IT ISN/T AS MUCH OF A SLAM DUNK AS ONE WOULD THINK. WHILE THE MOISTURE AHEAD OF THE FRONT SHOULD BE DECENTLY RICH WITH SFC DWPTS PUSHING 70F...H850 DWPTS BETWEEN 13-16C...AND PWATS AROUND 1.75" WHICH IS NEAR THE 99TH PERCENTILE FOR CLIMO AND THIS SHOULD RESULT IN A VERY UNSTABLE ATMOSPHERE...LIFTING MECHANISMS DO NOT LOOK AS GOOD AND SCENARIOS TO BRING THIS ABOUT DEPICTED BY MODELS DO NOT INSPIRE CONFIDENCE. FIRST...SYNOPTIC SETUP OF CD FROPA WILL FEATURE /LAND-BETWEEN-THE-LOWS/ WHICH WILL FEATURE WEAK LO LEVEL CONVERGENCE WITH A RAPID PUNCH OF RIDGING IMMEDIATELY BEHIND. UPPER LEVEL SUPPORT LOOKS WEAK IF MODEL SIGNALS ARE CORRECT...AND IF INCORRECT WOULD MEAN JUST MODEL NOISE. IN ADDITION...A COUPLE EXPICIT 4KM WRF MODELS (BOTH NMM AND ARW) ARE SHOWING CDFNT AND DRY LINE LIGHTING UP TONIGHT...WITH THE SRN PART REMAINING THE MOST ACTIVE AND DIVING THRU SWRN MO...PUSHING AN EFFECTIVE BOUNDARY THRU MUCH OF THE FA BEFORE THINGS FIRE UP AGAIN IN THE FAR ERN FA MONDAY AFTERNOON. WHILE IT IS HARD TO BUY FULLY INTO THE EXPLICIT MODELS...THE MESSAGE IS THAT OF NOT HI CONFIDENCE IN RAIN CHCS AS WELL AS KEEPING IN MIND THE ONGOING MILD-MODERATE DROUGHT IN THE AREA. HAVE ONCE AGAIN CAPPED POPS AT 50PCT AREAWIDE AND JUST DIFFERENTIATED IN ROUGH TIMING OF BEST CHCS. CONVECTIVE DEBRIS CLOUDS AND PCPN CHCS SHOULD KEEP TEMPS IN CHECK ON MONDAY...BUT OVERALL PREFERRED THE HIGHER MET MOS NUMBERS. SHOULD SEE DRY WX TUESDAY THRU WEDNESDAY NIGHT ALTHOUGH ORDINARILY ZONAL FLOW IN JUNE WOULD GIVE ONE CAUSE FOR PAUSE. LO PWATS AND HI PRES IN CONTROL SHOULD ENSURE THAT...ALTHOUGH THE VACATING SFC HI ON WEDNESDAY NIGHT MAY LET SOMETHING SLIP THRU WITH BRIEF WINDOW OF OPPORTUNITY BETWEEN THAT AND RETURN OF UPPER RIDGE...WILL KEEP A CLOSE EYE ON THAT. THE UPPER LEVEL RIDGE WILL THEN RETURN IN FORCE THURSDAY THRU NEXT SUNDAY BRINGING WITH IT A RETURN OF THE HEAT OF COURSE. HAVE MAX TEMPS AROUND 90F GOING EACH DAY FROM FRIDAY ON...BUT WOULD NOT BE SURPRISED TO SEE FRIDAY AND SATURDAY 3-4F WARMER. THERE ARE VERY WEAK SIGNALS FOR RAIN CHCS FOR MUCH OF THIS PERIOD BUT OVERALL SYNOPTIC PATTERN SHOULD KEEP ANY CONVECTION OF A PULSE NATURE FROM WEAK SHEAR ENVIRONMENT AND LIMITED TO AFTERNOON HOURS...AND GENERALLY ISOLATED IN COVERAGE. PROBABILITIES ARE LO ENOUGH TO LIMIT TO 20PCT OR LESS...AND THUS SILENT ON THE FCST. MODELS ATTEMPT TO BREAK RIDGE DOWN A BIT ON SUNDAY...BUT BY DIFFERENT MEANS...BUT RESULT MAY BE THE SAME. HAVE EDGED BACK 30PCT CHC FROM SATURDAY TO SUNDAY BUT THIS IS EVEN SCALED BACK FROM WHAT MODELS ARE SHOWING AS SOMETHING DOESN/T QUITE LOOK RIGHT ABOUT IT. TES && .AVIATION... ISSUED AT 1141 PM CDT SUN JUN 10 2012 THUNDERSTORMS OVER NORTHWEST MISSOURI WILL CONTINUE MOVING EAST AND SHOULD BE MOVING INTO CENTRAL AND NORTHEAST MISSOURI BETWEEN 09Z-10Z. UNCERTAIN HOW EXTENSIVE THE COVERAGE WILL BE AS IT MOVES THROUGH CENTRAL INTO EASTERN MISSOURI AFTER SUNRISE. CURRENT INDICATIONS ARE THAT IT WILL STILL BE WIDELY SCATTERED TO SCATTERED COVERAGE SINCE THE STORMS WILL BE MOVING AWAY FROM THE GREATEST INSTABILITY. THINK WIDELY SCATTERED STORMS WILL CONTINUE INTO MONDAY AFTERNOON UNTIL THE FRONT MOVES THROUGH THE AREA. ELSEWHERE AND OTHERWISE...AREAS OF CIGS BETWEEN 2000-3000FT ARE DEVELOPING OVER SOUTHEAST MISSOURI AND MAY CONTINUE TO SPREAD NORTH-NORTHEAST ACROSS SOUTHWEST ILLINOIS AND EASTERN SECTIONS OF THE STL METRO AREA. MVFR CIGS SHOULD LIFT QUICKLY AFTER SUNRISE AND VFR FLIGHT CONDITIONS WILL PREVAIL OUTSIDE OF THUNDERSTORMS. SPECIFICS FOR KSTL... LATEST SATELLITE PICTURES ARE SHOWING A MVFR DECK BETWEEN 2000-3000FT DEVELOPING AROUND KFAM. LOOKS LIKE THE DECK MAY PASS EAST OF THE TERMINAL...BUT I CAN`T RULE OUT SOME INTERMITTENT MVFR CIGS BEFORE SUNRISE. ANY MVFR CIGS THAT DO FORM SHOULD BREAK UP AND LIFT QUICKLY AFTER SUNRISE. STILL EXPECTING THUNDERSTORMS IN THE VICINITY AFTER 12Z...NOT SURE WHAT THE COVERAGE WILL BE SO WILL CONTINUE VCTS WORDING INSTEAD OF TEMPO. WIDELY SCATTERED SHOWERS AND STORMS WILL LIKELY CONTINUE INTO THE AFTERNOON...WITH THE THREAT FINALLY ENDING WITH THE COLD FRONT PASSAGE. CARNEY && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS GLASGOW MT
257 PM MDT MON JUN 11 2012 .SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY... A WEAK UPPER RIDGE OVER THE PACIFIC NORTHWEST INTO ALBERTA WILL MOVE OVER THE NORTHERN ROCKIES TONIGHT INTO TOMORROW. A WEAK SHORTWAVE WILL UNDERCUT THE UPPER RIDGE ON TUESDAY. ANOTHER SLIGHTLY STRONGER SHORTWAVE TROUGH WILL ROTATE AROUND THE UPPER LOW OVER THE GULF OF ALASKA AND MOVE OVER THE NORTHERN ROCKIES TUESDAY NIGHT INTO WEDNESDAY. THIS AFTERNOON AND EVENING THE WINDS WILL CONTINUE TO DROP OFF AS THE PRESSURE GRADIENT RELAXES AS A SURFACE HIGH MOVES IN FROM THE SOUTHWEST. SO WILL CANCEL THE LAKE WIND ADVISORY WITH THE AFTERNOON PACKAGE...A FEW HOURS EARLIER THEN EXPECTED. COULD BE SOME SCATTERED SHOWERS AROUND WITH SOME ISOLATED THUNDERSTORMS MOVING ACROSS THE REGION THIS EVENING WHICH WAS INDICATED ON THE LATEST HRRR RUN. THIS ACTIVITY WILL END BEFORE MIDNIGHT SO DROPPED POPS DOWN TO NOTHING AFTER THAT. TUESDAY...ADDED SOME SLIGHT CHANCE POPS OVER MY SW ZONES AS THE WEAK WAVE MOVES ACROSS SOUTHERN MONTANA. MODELS SOUNDING DO SHOW A SMALL AMOUNT OF ELEVATED CAPE ACROSS THE REGION SO A FEW ISOLATED STORMS ARE POSSIBLE SO WENT WITH A SLIGHT CHANCE OF THUNDER FOR TUESDAY AFTERNOON AND EVENING. TUESDAY NIGHT THROUGH WEDNESDAY...THE SLIGHTLY STRONGER SHORTWAVE WILL MOVE INTO WESTERN MONTANA WHICH WILL HELP GENERATE SOUTHWEST FLOW OVER EASTERN MONTANA. THIS WILL HELP TO DESTABILIZE THE MID LEVELS AHEAD OF THE SHORTWAVE. CAPE VALUES ARE ONCE AGAIN WEAK AND ELEVATED OTHER THUNDERSTORM PARAMETERS ARE WEAK AS WELL. THE THINKING AT THIS TIME IS JUST GENERAL THUNDER POSSIBLE FOR WEDNESDAY AFTERNOON AND EVENING. RSMITH .LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY... THE EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL SHORTWAVE TROUGH MOVING OVER MONTANA THURSDAY NIGHT. THE ASSOCIATED COLD FRONT SWINGS ACROSS THE AREA...MEETING MODERATE INSTABILITY...GENERATING THUNDERSTORMS IN THE EVENING. TIMING IS NOT CERTAIN WITH THIS WAVE DUE TO DIFFERENCES BETWEEN THE 12Z GFS AND THE 00Z ECMWF. THESE DIFFERENCES CONTINUE THROUGH THE ENTIRE PERIOD. ALTHOUGH NOT CERTAIN...THERE APPEARS TO BE A BREAK IN THE ACTION ON THURSDAY AND FRIDAY WITH A SHORT PERIOD UPPER RIDGE. THIS RIDGE GETS OVERTAKEN BY THE NEXT UPPER TROUGH LATE FRIDAY. FROM THIS POINT ON THE MODELS AGREE WITH AN UPPER TROUGH ONLY IN GENERAL...BUT DIFFER TOTALLY WITH THE EMBEDDED FEATURES. LATE IN THE SHIFT THE 12Z EC CONTINUES THE DISAGREEMENT WITH THE GFS. AGREE THE BEST BET IS TO MAINTAIN CHANCE POPS AND COOLER TEMPERATURES THROUGH THE ENTIRE PERIOD UNTIL BETTER AGREEMENT IS OBTAINED. SCT PREVIOUS DISCUSSION... SHORTWAVE TROUGH EXITS THE AREA WEDNESDAY NIGHT WITH LINGERING SHOWERS AND THUNDERSTORMS POSSIBLE ESPECIALLY IN THE NORTHEAST. HIGH PRESSURE SYSTEM AND SHORTWAVE RIDGE WILL BE OVER THE AREA ON THURSDAY WITH MAINLY DRY WEATHER. THE WESTERN ZONES COULD SEE A SHOWER OR THUNDERSTORM IN THE AFTERNOON AHEAD OF THE NEXT SYSTEM. AN UPPER TROUGH WILL BE OVER MONTANA AND NEARBY AREAS OVER THE WEEKEND AND EARLY NEXT WEEK. THERE ARE DIFFERENCES BETWEEN THE MODELS ON HOW THE TROUGH WILL BE CONFIGURED...TIMING OF SHORTWAVES WITHIN THE TROUGH AND WHEN AND WHERE INDIVIDUAL STORMS WILL OCCUR. NORTHEAST MONTANA WILL SEE RAIN WITH SHOWERS AND THUNDERSTORMS AT TIMES OVER THE PERIOD BUT MODEL CONFIDENCE IS TOO LOW TO TIME WHEN RAIN WILL OCCUR AT THIS POINT. PREVIOUS FORECAST IDEA OF A 30 TO 40 POP BROAD-BRUSH LOOKS REASONABLE FOR NOW. FORRESTER && .AVIATION... VFR. AN UPPER LEVEL RIDGE WILL MOVE ACROSS NORTHEAST MONTANA TONIGHT WHICH SHOULD END THE THREAT OF SHOWERS AND REDUCE SKY COVER. IN ADDITION A WEAK SURFACE PRESSURE DIFFERENCE WILL REDUCE WINDS TO LIGHT AND VARIABLE TONIGHT. ON TUESDAY A WEAK SHORTWAVE TROUGH NUDGES INTO THE NORTHERN ROCKIES LEADING TO THUNDERSTORMS. ALTHOUGH NORTHEAST MONTANA WILL DEVELOP MODERATE INSTABILITY...THE LACK OF LOCAL DISTURBANCES WILL DIMINISH THE THREAT OF THUNDERSTORMS. WITH A BROAD LEE SURFACE TROUGH...EXPECT WESTERLY WINDS TO REMAIN LESS THAN 15KTS. SCT && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1226 PM CDT MON JUN 11 2012 .AVIATION... /FOR THE 11.18Z TAF ISSUANCE/ MINIMAL AVIATION CONCERNS THROUGH MID-DAY TUESDAY. FAIR WEATHER CUMULUS WILL OCCUR OVER NORTHERN NEBRASKA THIS AFTERNOON...BUT CEILINGS WILL REMAIN VFR. HIGH PRESSURE WILL BUILD INTO THE UPPER MIDWEST TONIGHT AND TUESDAY WHICH WILL CAUSE WINDS TO DECREASE AND SHIFT THE NORTH WINDS AROUND TO THE SOUTH BY TUESDAY MORNING. THE BOUNDARY LAYER IS EXPECTED TO BECOME WELL MIXED AGAIN ON TUESDAY SO WILL SEE GUSTY CONDITIONS IN THE LATE MORNING AND AFTERNOON. FORECAST SOUNDINGS SHOWING AN INCREASE IN MOISTURE AT THE MID- LEVELS SO SHOULD SEE INCREASED CLOUD COVER TUESDAY...HOWEVER WILL REMAIN VFR. && .PREV DISCUSSION... /ISSUED 838 AM CDT MON JUN 11 2012/ UPDATE... HRRR AND RAP INDICATE LOWER 80S ACROSS SWRN NEB THIS AFTN. THE HRRR AND RAP WERE DEAD ON SUNDAY ACROSS THIS AREA SO THE FCST HAS BEEN UPDATED FOR SLIGHTLY WARMER TEMPS. REST OF FCST OKAY FOR NOW. PREV DISCUSSION... /ISSUED 300 AM CDT MON JUN 11 2012/ DISCUSSION... PACIFIC HIGH PRESSURE WILL BUILD EAST INTO THE CNTRL/NRN PLAINS TODAY. BREEZY NORTHWEST WINDS STARTING THE DAY BEHIND A SECONDARY COLD FRONTAL PASSAGE...WILL DIMINISH THIS AFTERNOON AS THE HIGH PRESSURE BUILDS IN. AIRMASS ACROSS THE AREA IS VERY DRY...WITH A DOWNSLOPE WIND COMPONENT AIDING THE DRYNESS. DEW POINTS GENERALLY IN THE 30S TODAY...WILL CREATE AFTERNOON RELATIVE HUMIDITY VALUES IN THE 15 TO 25 PERCENT RANGE. FORTUNATELY WINDS WILL BE DIMINISHING DURING THE PERIOD OF LOWEST RELATIVE HUMIDITY...SO FIRE WEATHER HEADLINES ARE NOT EXPECTED TO BE NEEDED. SOME GULF MOISTURE BEGINS TO RETURN NORTH INTO THE AREA TUESDAY...BUT REALLY DOESN/T GET INTO FULL SWING UNTIL TUESDAY NIGHT...WHEN H85 DEW POINTS RISE TO NEAR 14C ON SOUTHERLY LLJ. MODELS CONTINUE TO INDICATE A DECENT MID LEVEL WAVE WILL INTERACT WITH THE RETURNING MOISTURE...AND SCATTERED TSTM DEVELOPMENT IS POSSIBLE DURING THE AFTERNOON IN UPSLOPE ENVIRONMENT ACROSS THE NEB PANHANDLE/EASTERN WY AND CO. A LITTLE CONCERNED ABOUT THE LACK OF BETTER MOISTURE AT FIRST...SO WILL KEEP CHANCES SLIGHT TUESDAY AFTERNOON...AND INCREASE TO LOW CHANCE TUESDAY NIGHT AS STORMS MOVE EAST INTO AN INCREASINGLY FAVORABLE MOIST/UNSTABLE ENVIRONMENT DUE TO SOUTHERLY 45 KT LLJ. MID LEVEL WAVE AND CONVECTION SHOULD PUSH EAST OF THE AREA WEDNESDAY. A LARGE CLOSED LOW IS EXPECTED TO DEVELOP ACROSS SOUTHWEST CANADA BY THURSDAY. GFS ENSEMBLE MEAN KEEPS THE LOW INVOF SOUTHWEST CANADA THROUGH THE UPCOMING WEEKEND. BUILDING HEAT IS EXPECTED THURSDAY RIGHT THROUGH THE WEEKEND...AS ANY COLD FRONT ASSOCIATED WITH THE LOW STAYS WELL NORTHWEST OF THE AREA. RAIN CHANCES WILL NOT BE NIL HOWEVER...AS THE AREA APPEARS TO BE IN A RATHER ACTIVE SOUTHWEST FLOW ALOFT. LEEWARD TROUGHING DEVELOPS DAILY...AND THIS COULD SERVE FOR CONVECTIVE DEVELOPMENT. MOISTURE IS IN PLACE...WITH A DECENT TRAJECTORY OFF THE GULF DURING THE PERIOD. THE CAVEAT HERE IS POTENTIAL MID LEVEL WARM AIR...WHICH WOULD TEND TO CAP THE ATMOSPHERE. THIS WAS THE CASE THIS PAST WEEK...AND WON/T BE OVER AMBITIOUS WITH RAIN CHANCES AT THIS TIME. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...TAYLOR UPDATE...CDC AVIATION...BROOKS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
838 AM CDT MON JUN 11 2012 .UPDATE... HRRR AND RAP INDICATE LOWER 80S ACROSS SWRN NEB THIS AFTN. THE HRRR AND RAP WERE DEAD ON SUNDAY ACROSS THIS AREA SO THE FCST HAS BEEN UPDATED FOR SLIGHTLY WARMER TEMPS. REST OF FCST OKAY FOR NOW. && .PREV DISCUSSION... /ISSUED 640 AM CDT MON JUN 11 2012/ AVIATION... NO FLIGHT RESTRICTIONS ARE FORECAST THROUGH TONIGHT AND INTO TUESDAY MORNING. SMOKE FROM AT LEAST FOUR FIRES IN COLORADO WILL BE VISIBLE THROUGH TODAY AND BEYOND. BASED ON THE UPPER LEVEL WINDS... THE BASE OF THE SMOKE LAYER COULD BE AS LOW AS 7000 FEET AGL. HOWEVER...IT IS UNLIKELY THAT THE SMOKE WILL PRODUCE A CEILING. NORTHWEST WIND 300-330 IS EXPECTED TO INCREASE TO 12-18G21-27KT BY 15Z. WIND WILL THEN CONTINUE THUS UNTIL AFTER 01Z WHEN IT BECOMES LIGHT AND VARIABLE. PREV DISCUSSION... /ISSUED 300 AM CDT MON JUN 11 2012/ DISCUSSION... PACIFIC HIGH PRESSURE WILL BUILD EAST INTO THE CNTRL/NRN PLAINS TODAY. BREEZY NORTHWEST WINDS STARTING THE DAY BEHIND A SECONDARY COLD FRONTAL PASSAGE...WILL DIMINISH THIS AFTERNOON AS THE HIGH PRESSURE BUILDS IN. AIRMASS ACROSS THE AREA IS VERY DRY...WITH A DOWNSLOPE WIND COMPONENT AIDING THE DRYNESS. DEW POINTS GENERALLY IN THE 30S TODAY...WILL CREATE AFTERNOON RELATIVE HUMIDITY VALUES IN THE 15 TO 25 PERCENT RANGE. FORTUNATELY WINDS WILL BE DIMINISHING DURING THE PERIOD OF LOWEST RELATIVE HUMIDITY...SO FIRE WEATHER HEADLINES ARE NOT EXPECTED TO BE NEEDED. SOME GULF MOISTURE BEGINS TO RETURN NORTH INTO THE AREA TUESDAY...BUT REALLY DOESN/T GET INTO FULL SWING UNTIL TUESDAY NIGHT...WHEN H85 DEW POINTS RISE TO NEAR 14C ON SOUTHERLY LLJ. MODELS CONTINUE TO INDICATE A DECENT MID LEVEL WAVE WILL INTERACT WITH THE RETURNING MOISTURE...AND SCATTERED TSTM DEVELOPMENT IS POSSIBLE DURING THE AFTERNOON IN UPSLOPE ENVIRONMENT ACROSS THE NEB PANHANDLE/EASTERN WY AND CO. A LITTLE CONCERNED ABOUT THE LACK OF BETTER MOISTURE AT FIRST...SO WILL KEEP CHANCES SLIGHT TUESDAY AFTERNOON...AND INCREASE TO LOW CHANCE TUESDAY NIGHT AS STORMS MOVE EAST INTO AN INCREASINGLY FAVORABLE MOIST/UNSTABLE ENVIRONMENT DUE TO SOUTHERLY 45 KT LLJ. MID LEVEL WAVE AND CONVECTION SHOULD PUSH EAST OF THE AREA WEDNESDAY. A LARGE CLOSED LOW IS EXPECTED TO DEVELOP ACROSS SOUTHWEST CANADA BY THURSDAY. GFS ENSEMBLE MEAN KEEPS THE LOW INVOF SOUTHWEST CANADA THROUGH THE UPCOMING WEEKEND. BUILDING HEAT IS EXPECTED THURSDAY RIGHT THROUGH THE WEEKEND...AS ANY COLD FRONT ASSOCIATED WITH THE LOW STAYS WELL NORTHWEST OF THE AREA. RAIN CHANCES WILL NOT BE NIL HOWEVER...AS THE AREA APPEARS TO BE IN A RATHER ACTIVE SOUTHWEST FLOW ALOFT. LEEWARD TROUGHING DEVELOPS DAILY...AND THIS COULD SERVE FOR CONVECTIVE DEVELOPMENT. MOISTURE IS IN PLACE...WITH A DECENT TRAJECTORY OFF THE GULF DURING THE PERIOD. THE CAVEAT HERE IS POTENTIAL MID LEVEL WARM AIR...WHICH WOULD TEND TO CAP THE ATMOSPHERE. THIS WAS THE CASE THIS PAST WEEK...AND WON/T BE OVER AMBITIOUS WITH RAIN CHANCES AT THIS TIME. && .LBF WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM/EXTENDED...CDC AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1007 PM EDT TUE JUN 12 2012 .SYNOPSIS... A COLD FRONT WILL MOVE SOUTHEAST AND ACROSS THE EASTERN CAROLINAS WEDNESDAY...MOVING OFFSHORE WEDNESDAY NIGHT. SHOWERS AND THUNDERSTORMS WILL END AS THE FRONT MOVES OFFSHORE. LOW PRESSURE SHOULD DEVELOP ALONG THE FRONT THURSDAY...BRINGING NORTHEAST WINDS AND MILD TEMPERATURES TO THE CAROLINAS THURSDAY INTO SATURDAY. HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHEAST EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1005 PM TUESDAY...DECENT CLUSTER OF SHOWERS AND THUNDERSTORMS EXTENDS ACROSS THE SE NC COASTAL COUNTIES AND THE ADJACENT COASTAL AND OFFSHORE WATERS. MOVEMENT IS TO THE ENE NEAR 15 MPH. VIA LATEST KLTX RAINFALL ESTIMATES...LOOK FOR AN ADDITIONAL ONE TENTH TO ONE QUARTER OF AN INCH...EXCEPT ONE HALF TO 1 INCH FROM ANY OF THE STRONGER SHOWERS AND STORMS. THIS CLUSTER/AREA SHOULD TRACK NE OF THE AREA BY MIDNIGHT TO 1 AM. THE DEEP PLUME OF MOISTURE FROM THE TROPICS IS SLOWLY BEING CUT OFF AS THE MID-UPPER LEVEL TROF REACHES THE EASTERN CAROLINAS...VIA THE LATEST NEAR TERM RUC MODEL HOURLY RUNS. AS A RESULT...THE BEST CHANCES FOR PCPN AND THE ORIENTATION OF OVERNIGHT POPS ACROSS THE ILM CWA...WILL CONTINUE TO BE GEARED ALONG THE COASTAL COUNTIES AND ADJACENT COASTAL/OFFSHORE WATERS. THE 5H VORT ACROSS SOUTHERN GA IS PROGGED TO TRACK OFF THE GA COAST LATE THIS EVENING AND OVERNIGHT AND SHOULD NOT BE A PROBLEM FOR THE ILM CWA. WILL HAVE TO MAINLY DEAL WITH THE APPROACH OF FRONTAL DYNAMICS AND ANY SHEARED MID LEVEL VORTS ACCOMPANYING IT FOR THE CONTINUED POPS OVERNIGHT. TWEAKED MIN TEMPS UPWARDS BY A DEGREE OR 2 BASED ON LATEST TRENDS AND A PEAK LOOK AT THE NEW 00Z GUIDANCE. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...THE BAND OF DEEP TROPICAL MOISTURE WILL BEGIN TO NUDGE OFFSHORE WEDNESDAY AS THE 500 MB UPPER TROUGH BEGINS TO KICK EAST AND FINALLY OFF THE COAST WEDNESDAY NIGHT. THE SURFACE COLD FRONT WILL ACCOMPANY THE UPPER TROUGH TO THE COAST WEDNESDAY AFTERNOON...BUT A WEAK SEABREEZE WILL HOLD UP THE FRONT`S EASTWARD PROGRESS UNTIL EVENING. THE HIGHEST CHANCES FOR SHOWERS AND STORMS WEDNESDAY WILL OCCUR NEAR THE COAST WHERE ENHANCED LOW-LEVEL CONVERGENCE WILL COEXIST WITH THE LINGERING TROPICAL HIGH-PRECIPITABLE WATER ATMOSPHERE. CONVECTIVE COVERAGE SHOULD RANGE FROM 50-60 PERCENT ALONG THE COAST TO ONLY 20-30 PERCENT ALONG AND WEST OF INTERSTATE 95. UNLIKE TODAY...WEDNESDAY`S STORM MOTION SHOULD BE FROM NORTH TO SOUTH AS THE MID-LEVEL FLOW SHIFTS BEFORE THE SURFACE FRONT ARRIVES. DRIER AIR SHOULD OVERSPREAD THE REGION FROM NW TO SE WEDNESDAY NIGHT WITH MODEL PRECIP WATER VALUES DROPPING FROM ~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`S PROGRESS EAST. SCATTERED SHOWERS AND STORMS WILL ACCOMPANY THE SLOW-MOVING FRONT WEDNESDAY. THE FRONT WILL RESUME ITS OFFSHORE MOVEMENT DURING THE EVENING AND SHOULD MOVE WELL OFFSHORE WEDNESDAY NIGHT. THE 12Z NAM HAS COME INTO AGREEMENT WITH YESTERDAY`S GFS (AND TODAY`S GFS AS WELL) SHOWING THE DEVELOPMENT OF MULTIPLE CENTERS OF LOW PRESSURE OFFSHORE THURSDAY ALONG THE FRONT. THE EXACT LOCATION OF THESE LOWS ARE NOT AS IMPORTANT AS THE OVERALL IMPACT ON TIGHTENING OUR LOCAL PRESSURE GRADIENT THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH A SUBSTANTIAL INCREASE IN WIND SPEEDS EXPECTED ALONG THE COAST. OUR LATEST FORECAST INCREASES WINDS INTO THE 20-25 KT RANGE THURSDAY NIGHT WITH THE POTENTIAL FOR GUSTS APPROACHING 30 KT LATE. THIS WILL BUILD SEAS FROM A GENTLE 2-3 FT WEDNESDAY...TO AS HIGH AS 6-8 FEET NORTH AND EAST OF CAPE FEAR LATE THURSDAY NIGHT. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 300 PM TUESDAY...PERSISTENT NORTHEAST FLOW IS EXPECTED OVER THE WATERS AS SURFACE HIGH PRESSURE EXTENDS SOUTHWARD ACROSS THE INLAND CAROLINAS...AND A TROUGH LINGERS WELL OFFSHORE. A MODERATE PRESSURE GRADIENT ACROSS THE WATERS WILL LIKELY KEEP WINDS IN A 15-25 KT RANGE...AND A PERSISTENT FETCH SHOULD ALLOW SEAS TO BUILD AS HIGH AS 5-7 FT IN THE 10-20 NM RANGE. SMALL CRAFT ADVISORY THRESHOLDS WILL BE APPROACHED...IF NOT EXCEEDED AT TIMES FRIDAY AND SATURDAY...ESPECIALLY ACROSS THE NORTH CAROLINA COASTAL WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...TRA NEAR TERM...DCH SHORT TERM...TRA LONG TERM...CRM AVIATION...SRP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
745 PM EDT TUE JUN 12 2012 .SYNOPSIS... A COLD FRONT WILL MOVE SOUTHEAST AND ACROSS THE EASTERN CAROLINAS WEDNESDAY...MOVING OFFSHORE WEDNESDAY NIGHT. SHOWERS AND THUNDERSTORMS WILL END AS THE FRONT MOVES OFFSHORE. LOW PRESSURE SHOULD DEVELOP ALONG THE FRONT THURSDAY...BRINGING NORTHEAST WINDS AND MILD TEMPERATURES TO THE CAROLINAS THURSDAY INTO SATURDAY. HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHEAST EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 740 PM TUESDAY...THE DEEP PLUME OF MOISTURE FROM THE TROPICS IS SLOWLY BEING CUT OFF AS THE MID-UPPER LEVEL TROF REACHES THE EASTERN CAROLINAS...VIA THE LATEST NEAR TERM RUC MODEL HOURLY RUNS. AS A RESULT...THE BEST CHANCES FOR PCPN AND THE ORIENTATION OF OVERNIGHT POPS ACROSS THE ILM CWA...WILL BE GEARED ALONG THE COASTAL COUNTIES AND ADJACENT COASTAL WATERS. THE 5H VORT ACROSS SOUTHERN GA IS PROGGED TO TRACK OFF THE GA COAST LATE THIS EVENING AND OVERNIGHT AND SHOULD NOT BE A PROBLEM FOR THE ILM CWA. WILL MAINLY DEAL WITH THE APPROACH OF FRONTAL DYNAMICS AND ANY SHEARED MID LEVEL VORT ACCOMPANYING IT FOR THE CONTINUED POPS OVERNIGHT. MIN TEMPS LOOK ON TARGET AND SEE NO REASON TO TWEAK AT THIS TIME. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...THE BAND OF DEEP TROPICAL MOISTURE WILL BEGIN TO NUDGE OFFSHORE WEDNESDAY AS THE 500 MB UPPER TROUGH BEGINS TO KICK EAST AND FINALLY OFF THE COAST WEDNESDAY NIGHT. THE SURFACE COLD FRONT WILL ACCOMPANY THE UPPER TROUGH TO THE COAST WEDNESDAY AFTERNOON...BUT A WEAK SEABREEZE WILL HOLD UP THE FRONT`S EASTWARD PROGRESS UNTIL EVENING. THE HIGHEST CHANCES FOR SHOWERS AND STORMS WEDNESDAY WILL OCCUR NEAR THE COAST WHERE ENHANCED LOW-LEVEL CONVERGENCE WILL COEXIST WITH THE LINGERING TROPICAL HIGH-PRECIPITABLE WATER ATMOSPHERE. CONVECTIVE COVERAGE SHOULD RANGE FROM 50-60 PERCENT ALONG THE COAST TO ONLY 20-30 PERCENT ALONG AND WEST OF INTERSTATE 95. UNLIKE TODAY...WEDNESDAY`S STORM MOTION SHOULD BE FROM NORTH TO SOUTH AS THE MID-LEVEL FLOW SHIFTS BEFORE THE SURFACE FRONT ARRIVES. DRIER AIR SHOULD OVERSPREAD THE REGION FROM NW TO SE WEDNESDAY NIGHT WITH MODEL PRECIP WATER VALUES DROPPING FROM ~2.0 INCHES TO BARELY 0.6 INCHES BY 12Z THURSDAY. MULTIPLE AREAS OF LOW PRESSURE WILL DEVELOP ALONG THE FRONT WELL OFFSHORE THURSDAY AND THURSDAY NIGHT. THE MAIN IMPACTS TO LAND WILL BE INCREASING NORTH TO NORTHEAST WINDS AND ENOUGH COLD ADVECTION TO KEEP TEMPERATURES AND DEWPOINTS SURPRISINGLY MILD FOR MID-JUNE. ENOUGH ATLANTIC MOISTURE SHOULD GET ADVECTED BACK ONSHORE LATE THURSDAY AFTERNOON INTO THURSDAY NIGHT TO SPREAD A BATCH OF LOW CLOUDS INLAND ALONG THE COAST WITH THE LARGEST IMPACTS EXPECTED AROUND WILMINGTON. MOS TEMPERATURES LOOK PRETTY GOOD THROUGH THE PERIOD WITH LITTLE SPREAD SEEN BETWEEN NUMBERS FROM THE GFS...NAM...OR THE EXPERIMENTAL ECMWF MOS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 300 PM TUESDAY...SYNOPTIC PATTERN WILL BE CHARACTERIZED BY A MID-LEVEL RIDGE AXIS EXTENDING FROM THE GREAT LAKES SOUTHWESTWARD TO THE SOUTHERN PLAINS...AND A MID-LEVEL TROUGH AXIS A FEW HUNDRED MILES OFF THE CAROLINA COAST. AT THE SURFACE...THIS WILL TRANSLATE INTO WEDGE SCENARIO AS HIGH PRESSURE EXTENDS SOUTHWARD ALONG THE EASTERN SIDE OF THE APPALACHIANS...WITH NORTHEASTERLY FLOW KEEPING TEMPERATURES ON THE COOL SIDE OF CLIMATOLOGY. MODELS SUGGEST THIS PATTERN WILL PERSIST THROUGH THE EXTENDED PERIOD. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 23Z...WIDELY SCATTERED CONVECTION CONTINUES ACROSS THE AREA...BUT REMAINS WEAK. COASTAL TERMINALS WILL LIKELY SEE ANOTHER ROUND WITH LESS AREAL COVERAGE EXPECTED AT KLBT AND KFLO. MANY AREAS RECEIVED RAINFALL TODAY AND MAY SEE IFR CIGS DEVELOP OVERNIGHT IN THE AREAS THAT RECEIVED THE MOST RAINFALL. THUS BROUGHT IN TEMPO IFR CONDITIONS THROUGH AROUND 1200 UTC WEDNESDAY. HEATING WILL ALLOW THE CIGS TO LIFT DURING THE MORNING...BUT SCATTERED CONVECTION IS EXPECTED TO REDEVELOP WITH THE HEATING WEDNESDAY AFTERNOON. EXTENDED OUTLOOK...VFR THROUGH THE FORECAST PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 740 PM TUESDAY...SCEC WILL BE ALLOWED TO EXPIRE AT MIDNIGHT FOR THE ILM NC WATERS. UNTIL THE COLD FRONT REACHES THE COASTAL WATERS WHICH WILL LIKELY BE CLOSER TO DAYBREAK WED...THE SFC PG AND PATTERN AHEAD OF IT WILL YIELD SW WINDS AROUND 15 KT...OCCASIONALLY UP TO 20 KT FOR THE LOCAL WATERS OFF CAPE FEAR. SIGNIFICANT SEAS WILL RUN 3 TO 4 FT...UP TO 5 FT ACROSS THE LOCAL WATERS OFF CAPE FEAR THROUGH MIDNIGHT. DOMINANT PERIODS WILL BE AROUND 6 SECONDS. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...A SURFACE COLD FRONT WILL MAKE ITS WAY DOWN TO THE COAST MORNING WEDNESDAY...BUT IT SHOULD STALL NEAR THE BEACHES DURING THE AFTERNOON AS A WEAK SEABREEZE HOLDS UP THE FRONT`S PROGRESS EAST. SCATTERED SHOWERS AND STORMS WILL ACCOMPANY THE SLOW-MOVING FRONT WEDNESDAY. THE FRONT WILL RESUME ITS OFFSHORE MOVEMENT DURING THE EVENING AND SHOULD MOVE WELL OFFSHORE WEDNESDAY NIGHT. THE 12Z NAM HAS COME INTO AGREEMENT WITH YESTERDAY`S GFS (AND TODAY`S GFS AS WELL) SHOWING THE DEVELOPMENT OF MULTIPLE CENTERS OF LOW PRESSURE OFFSHORE THURSDAY ALONG THE FRONT. THE EXACT LOCATION OF THESE LOWS ARE NOT AS IMPORTANT AS THE OVERALL IMPACT ON TIGHTENING OUR LOCAL PRESSURE GRADIENT THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH A SUBSTANTIAL INCREASE IN WIND SPEEDS EXPECTED ALONG THE COAST. OUR LATEST FORECAST INCREASES WINDS INTO THE 20-25 KT RANGE THURSDAY NIGHT WITH THE POTENTIAL FOR GUSTS APPROACHING 30 KT LATE. THIS WILL BUILD SEAS FROM A GENTLE 2-3 FT WEDNESDAY...TO AS HIGH AS 6-8 FEET NORTH AND EAST OF CAPE FEAR LATE THURSDAY NIGHT. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 300 PM TUESDAY...PERSISTENT NORTHEAST FLOW IS EXPECTED OVER THE WATERS AS SURFACE HIGH PRESSURE EXTENDS SOUTHWARD ACROSS THE INLAND CAROLINAS...AND A TROUGH LINGERS WELL OFFSHORE. A MODERATE PRESSURE GRADIENT ACROSS THE WATERS WILL LIKELY KEEP WINDS IN A 15-25 KT RANGE...AND A PERSISTENT FETCH SHOULD ALLOW SEAS TO BUILD AS HIGH AS 5-7 FT IN THE 10-20 NM RANGE. SMALL CRAFT ADVISORY THRESHOLDS WILL BE APPROACHED...IF NOT EXCEEDED AT TIMES FRIDAY AND SATURDAY...ESPECIALLY ACROSS THE NORTH CAROLINA COASTAL WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...TRA NEAR TERM...DCH SHORT TERM...TRA LONG TERM...CRM AVIATION...SRP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
752 PM EDT TUE JUN 12 2012 .SYNOPSIS... A COLD FRONT WILL PUSH SLOWLY SOUTHEAST THROUGH THE REGION LATE TONIGHT AND WEDNESDAY...BRINGING COOLER AND MUCH DRIER CONDITIONS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 PM TUESDAY... OVERVIEW: A WEAK MID-LEVEL TROUGH CENTERED OVER THE WESTERN CAROLINAS (NEAR I-77 PER 700 MB 15Z SPC MESOANALYSIS) WILL TRACK SLOWLY EASTWARD INTO THE CENTRAL CAROLINAS THIS AFTERNOON/EVENING...PROGRESSING TO THE CAROLINA COAST BY 12Z WED MORNING. IN THE LOWER LEVELS...A SFC-H85 REFLECTION ATTENDANT THE MID-LEVEL WAVE WILL ALSO PROGRESS EASTWARD INTO THE CENTRAL CAROLINAS. FURTHER UPSTREAM...A COLD FRONT EXTENDING SSW FROM THE GREAT LAKES INTO THE WESTERN OH/TN VALLEY AT 15Z THIS MORNING WILL PROGRESS INTO THE SOUTHERN APPALACHIANS BY 00Z THIS EVENING. THE FRONT WILL SLOW DOWN AND BECOME INCREASINGLY WEST-EAST ORIENTED TONIGHT...THEN PROGRESS SOUTH THROUGH THE AREA ON WED AS HIGH PRESSURE STRENGTHENS OVER THE GREAT LAKES AND NORTHERN MID-ATLANTIC. PRECIPITATION CHANCES: DESPITE A VERY MOIST BOUNDARY LAYER WITH SFC DEWPOINTS IN THE LOWER 70S...WEAK MID-LEVEL LAPSE RATES AND EXTENSIVE CLOUD COVER OVER THE AREA SHOULD TEMPER DIURNAL DESTABILIZATION THIS AFTERNOON ALONG/EAST OF HWY 1...WHERE 500-1000 J/KG OF MLCAPE IS PROGGED AT BEST. IN THE WESTERN PIEDMONT...LESS CLOUD COVER AND BETTER INSOLATION WILL LEAD TO STRONGER DIURNAL DESTABILIZATION...WITH MLCAPE VALUES PROGGED AT 1000-1500 J/KG. BASED ON SPC MESOANALYSIS AND THE LATEST OBSERVATIONAL DATA...THE LOW/MID-LEVEL TROUGH IN VICINITY OF I-77 OVER THE WESTERN CAROLINAS AT 15Z WILL BE THE PRIMARY FOCUSING MECHANISM FOR CONVECTION TODAY AS IT PROGRESSES EASTWARD INTO CENTRAL NC IN THE PRESENCE OF A TROPICAL (PWAT NEAR 2.00") AIRMASS. 15Z VWP DATA FROM SURROUNDING SITES ALREADY SHOW WESTERLY LOW-LEVEL FLOW AT GSP/RNK/CAE...SUGGESTING THE BEST LOW-LEVEL CONVERGENCE AND FOCUS FOR CONVECTION TODAY SHOULD REMAIN ALONG AND EAST OF HIGHWAY 1...AND WILL MAINTAIN CATEGORICAL (80%) PRECIPITATION CHANCES IN THAT AREA. FURTHER WEST THE FORECAST IS MORE UNCERTAIN. ALTHOUGH THE BEST CONVERGENCE WITH THE LOW/MID-LEVEL TROUGH IS ALREADY IN VICINITY OF HWY 1...15Z WV IMAGERY SHOWED A SHEAR AXIS PROGRESSING EASTWARD THROUGH EASTERN KY/CENTRAL TN...AND THE LATEST RAP MODEL DATA PROGS THIS FEATURE TO PROGRESS INTO THE MOUNTAINS AND FOOTHILLS LATER THIS AFTERNOON AND EVENING (IN VICINITY OF PEAK HEATING). ALTERNATELY...DIFFERENTIAL HEATING IN THE PRESENCE OF A VERY MOIST AIRMASS MAY LEAD TO THE DEVELOPMENT OF ISOLD/SCT CONVECTION IN THE MOUNTAINS EARLY THIS AFTERNOON...WHICH COULD PROGRESS EAST/SE INTO THE WESTERN PIEDMONT BY MID TO LATE AFTERNOON VIA 15 KT W/NW MID-LEVEL FLOW. THE 00-12Z HIGH-RES CONVECTION ALLOWING MODELS OFFER VARYING SOLUTIONS WITH REGARD TO CONVECTION THIS AFTERNOON... RANGING FROM LITTLE MORE THAN ISOLD CONVECTION IN THE WESTERN PIEDMONT TO THE DEVELOPMENT OF A SW-NE ORIENTED LINE OF CONVECTION FROM CLT-INT AT 20Z THAT PROGRESSES THROUGH ALL OF CENTRAL NC BY SUNSET. ADDITIONALLY...LARGE MCS`S UPSTREAM OF THE AREA LAST NIGHT MAY HAVE ALTERED THE MID-LEVELS IN A MANNER NOT CAPTURED WELL BY THE 00-06Z MODEL RUNS...ADDING FURTHER UNCERTAINTY TO THE PRECIP FORECAST. WITH THE ABOVE IN MIND...FEEL THAT IT WOULD BE UNWISE TO REDUCE PRECIP CHANCES MUCH BELOW WHAT HAS BEEN PREVIOUSLY ADVERTISED IN THE WESTERN PIEDMONT. AFTER SUNSET...EXPECT CONVECTION TO WEAKEN AND SHIFT SOUTHEAST IN CONCERT WITH THE MID-LEVEL TROUGH...WITH PRECIP CHANCES DECREASING AND ENDING FROM NW-SE BY OR SHORTLY AFTER MIDNIGHT AS A DRIER MID-LEVEL AIRMASS PROGRESSES INTO THE AREA. SEVERE/FLOODING THREAT: DO NOT ANTICIPATE A THREAT FOR AREA-WIDE FLOODING GIVEN A LACK OF WIDESPREAD HEAVY RAIN YESTERDAY (ISOLD AREAS GOT 1-2") AND 1-3 HR FLASH FLOOD GUIDANCE IN THE 2-4" RANGE IN MOST LOCATIONS (EXCLUDING URBAN AREAS). HOWEVER...GIVEN THE TROPICAL AIRMASS IN PLACE... RAINFALL RATES WITH CONVECTION THIS AFTERNOON WILL BE ON THE HIGH-END...AND A LOCALIZED THREAT FOR FLOODING WILL CERTAINLY BE PRESENT...PRIMARILY IN URBAN AREAS. ALTHOUGH MODERATE INSTABILITY WILL BE POSSIBLE IN THE WESTERN PIEDMONT THIS AFT/EVE...DEEP LAYER SHEAR IS PROGGED TO BE NO HIGHER THAN 15-20 KT...AND ORGANIZED CONVECTION IS NOT EXPECTED. RELATIVELY BETTER INSOLATION IN THE WESTERN PIEDMONT MAY YIELD 500-750 J/KG OF DCAPE THIS AFTERNOON...IN THE PRESENCE OF 1.50"+ PWAT VALUES. THIS COMBINATION OF PRECIP LOADING AND BOUNDARY LAYER EVAP COOLING COULD RESULT IN ISOLD SEVERE DOWNBURSTS IN THE WESTERN PIEDMONT BETWEEN 300-800 PM. TEMPERATURES: EXTENSIVE CLOUD COVER AND SHOWER ACTIVITY WILL KEEP HIGHS TODAY SIMILAR TO YESTERDAY...IN THE LOWER 80S...OR 81-85F. LOWS TONIGHT WILL PRIMARILY DEPEND ON THE PROGRESS OF THE COLD (DRY) FRONT APPROACHING THE AREA FROM THE NORTHWEST. THE BULK OF MODEL GUIDANCE AGREES THAT THE FRONT SHOULD MAKE PROGRESS INTO THE N/NW PIEDMONT BY SUNRISE WED...AND WILL INDICATE LOWS RANGING FROM THE MID/UPPER 60S N/NW TO ~70F SOUTHEAST. -VINCENT && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 245 PM TUESDAY... WEDNESDAY: THE MID-LEVEL TROUGH TRACKING EASTWARD INTO CENTRAL NC TODAY IS PROGGED TO PROGRESS TO THE CAROLINA COAST BY 12Z WED...WITH A MUCH DRIER MID-LEVEL AIRMASS OVERSPREADING THE AREA. IN THE LOWER LEVELS...THE SW-NE ORIENTED COLD FRONT LOCATED OVER THE CENTRAL OH/TN VALLEY THIS AFTERNOON WILL BECOME MORE WEST-EAST ORIENTED AS IT MOVES INTO THE MID-ATLANTIC TONIGHT. THE FRONT WILL PROGRESS SOUTHWARD THROUGH CENTRAL NC DURING THE DAY WED AS HIGH PRESSURE STRENGTHENS OVER THE GREAT LAKES. THE LATEST MODEL GUIDANCE SHOWS THE LEADING EDGE OF THE FRONT (AND WIND SHIFT TO THE N/NE) OCCURRING AROUND OR SHORTLY AFTER SUNRISE WED MORNING...HOWEVER...MODEL GUIDANCE IS IN RELATIVELY GOOD AGREEMENT THAT THE BOUNDARY LAYER WILL REMAIN RELATIVELY MOIST THROUGH PEAK HEATING WED...WITH THE BULK OF THE DRIER AIR NOT ADVECTING INTO CENTRAL NC FROM THE NORTH/NE UNTIL THE LATE AFTERNOON/EVENING. FCST SOUNDINGS SHOW SFC DEWPOINTS IN THE MID 60S ALMOST EVERYWHERE...WITH UPPER 60S TO NEAR 70F IN SOUTH/SW PORTIONS OF THE AREA. GIVEN THE RESIDUAL MOIST BOUNDARY LAYER AND GOOD INSOLATION ASSOC/W DRIER MID-LEVELS...MLCAPE VALUES COULD REACH AS HIGH AS 1000-1500 J/KG DURING PEAK HEATING... PRIMARILY IN THE SANDHILLS/SW PIEDMONT. THOUGH THE BEST LOW-LEVEL CONVERGENCE SHOULD BE ALONG OR JUST OFFSHORE THE CAROLINA COAST WED AFTERNOON...MODEL GUIDANCE INDICATES SHORTWAVE ENERGY PROGRESSING INTO WESTERN PORTIONS OF THE STATE BY MID/LATE AFTERNOON. IT IS POSSIBLE THAT ISOLD CONVECTION COULD DEVELOP OVER PORTIONS OF THE AREA BETWEEN 21-00Z IF SHORTWAVE ENERGY ARRIVES DURING PEAK HEATING AND/OR PRIOR TO THE ADVECTION OF THE DRIER /MORE STABLE/ LOW-LEVEL AIRMASS FROM THE NORTH. AT THIS TIME THE SHORTWAVE ENERGY APPEARS TO ARRIVE A BIT TOO LATE...AND CONSIDERABLE DRY AIR ALOFT WOULD LIKELY ACT TO HINDER EVEN ISOLD DEVELOPMENT. WILL KEEP PRECIP CHANCES CONFINED TO A SLIGHT CHANCE SOUTH OF HWY 64 IN THE SANDHILLS/SW PIEDMONT DURING THE AFTERNOON. WITH MOSTLY SUNNY SKIES AND COLD ADVECTION OCCURRING CLOSER TOWARD SUNSET EXPECT HIGHS IN THE MID/UPPER 80S. -VINCENT WEDNESDAY NIGHT THROUGH FRIDAY: MUCH DRIER AND COOLER CONDITIONS ARRIVE WEDNESDAY NIGHT AND THURSDAY...LASTING THROUGH THE WEEKEND. THE MODELS ARE IN GOOD GENERAL AGREEMENT IN THE DEVELOPMENT OF A WESTERN ATLANTIC UPPER TROUGH WITH OUR REGION ON THE SUBSIDENCE SIDE OF THE TROUGH WEDNESDAY NIGHT THROUGH THE END OF THE WEEK. THE MUCH DRIER AIR WILL BE FELT WEDNESDAY NIGHT AND THURSDAY AS DEW POINTS FALL INTO THE 50S WITH THE NNE LOW LEVEL FLOW. THE SKIES ARE EXPECTED TO BE MOSTLY CLEAR WEDNESDAY NIGHT. SOME MIXING WILL CONTINUE WEDNESDAY NIGHT AS THE HIGH PRESSURE BUILDS SOUTHWARD DOWN THE EASTERN SEABOARD INTO NC/SC. LOWS MAY BE HELD UP AS WELL BY THE NE FLOW AT 5-10 MPH. WE WILL LEAN TOWARD THE WARMER NAM GUIDANCE...60-65 FOR LOWS. THURSDAY...MODELS ALSO SUGGEST A PERIOD OF CLOUDINESS WILL BE LIKELY AS THE NE FLOW ADVECTS ATLANTIC MOISTURE ACROSS EASTERN VA INTO CENTRAL NC DURING THE AFTERNOON AND EVENING. THE FORECAST SOUNDINGS INDICATE PARTLY SUNNY TO MOSTLY CLOUDY SKIES THROUGH THE AFTERNOON WITH HIGHS 75-82 (NE TO S). AS THE SURFACE HIGH PRESSURE STRENGTHENS AND MOVES TOWARD THE MID-ATLANTIC STATES THURSDAY INTO THURSDAY NIGHT...THE SKIES ARE EXPECTED TO BECOME MOSTLY CLEAR/MOSTLY SUNNY. LOWS WILL DIP INTO THE 55-62 RANGE THURSDAY MORNING...WITH HIGHS EXPECTED TO HOLD IN THE UPPER 70S TO LOWER 80S. THESE READINGS WILL BE 5-8 DEGREES BELOW THE MID JUNE NORMALS. -BADGETT && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 220 PM TUESDAY... AN EXTENDED DRY AND COOL PATTERN FOR MID JUNE. THE SURFACE RIDGE ALONG THE EAST COAST IS FORECAST TO STRENGTHEN FRIDAY INTO THE WEEKEND WITH A CONTINUED SUPPLY OF COOL AND DRY AIR ADVECTION INTO NC. FRI-SUN SHOULD FEATURE MOSTLY CLEAR NIGHTS AND MOSTLY SUNNY DAYS WITH LOW HUMIDITY. LOWS WILL BE IN THE 50S TO AROUND 60 (5-10 DEGREES BELOW NORMAL). HIGHS WILL BE IN THE 77-82 RANGE... OR 5-8 DEGREES BELOW NORMAL). BY MONDAY AND TUESDAY... THERE IS A CHANCE OF SOME RETROGRESSION OF THE UPPER PATTERN WITH THE MID/UPPER LOW OVER THE WESTERN ATLANTIC POSSIBLY DRIFTING SLOWLY WESTWARD TOWARD THE EASTERN SEABOARD. STRONG RIDING IS EXPECTED TO OUR NW OVER THE OHIO VALLEY AND MIDWEST. THIS WILL LEAD TO A CONTINUED NORTHERLY FLOW ALOFT WITH DRY CONDITIONS. TEMPERATURES AND HUMIDITIES WILL MODERATE BACK CLOSER TO MID JUNE NORMALS... YET NOT QUITE ALL THE WAY BACK. LOWS 62-67 WITH HIGHS IN THE MID TO UPPER 80S. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 750 PM TUESDAY... 24 HOUR TAF PERIOD: AS OF 00Z A SMALL LINE OF THUNDERSTORMS IS MOVING INTO THE PIEDMONT TRIAD AREA. HAVE TEMPO GROUP FOR THUNDER IN THE TAFS AT KGSO AND KINT THROUGH 3Z. OUTSIDE OF THE TRIAD...EARLIER RAIN AND THUNDER HAS EXITED TO THE EAST. WILL WAIT TO SEE HOW THUNDER THREAT TO THE NORTH AND WEST EVOLVES BEFORE PUTTING ANYTHING INTO THE KRDU...KFAY...AND KRWI TAFS. EXPECT FOG AND OR LOW STRATUS AT ALL SITES AFTER 3Z AND CONTINUING UNTIL NEAR SUNRISE. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT...EVENTUALLY SHIFTING AROUND TO NORTH NORTHEASTERLY BY WEDNESDAY MORNING AND MAY TAKE ON A MORE EASTERLY COMPONENT BY THE AFTERNOON. BROKEN CEILINGS WILL REMAIN THROUGHOUT THE AFTERNOON ON WEDNESDAY MOSTLY IN THE 3-5 KFT RANGE. A COLD FRONT WILL LINGER ACROSS SOUTHERN PORTIONS OF THE AREA TOMORROW AFTERNOON WHICH COULD LEAD TO SOME SHOWER AND THUNDERSTORM ACTIVITY AT KFAY BUT HAVE KEPT IT OUT OF THE 00Z TAF PACKAGE UNTIL FORECAST CONFIDENCE RISES. VFR CONDITIONS ARE LARGELY EXPECTED THROUGH THE END OF THE WEEK HOWEVER SOME MVFR CEILINGS MAY RESULT FROM THE PREVAILING NORTHEASTERLY FLOW DURING THE EARLY MORNING HOURS EACH DAY THIS WEEK. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BADGETT NEAR TERM...VINCENT SHORT TERM...VINCENT/BADGETT LONG TERM...BADGETT AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
302 PM EDT MON JUN 11 2012 .SYNOPSIS... A TROPICAL AIRMASS WILL CONTINUE TO BRING OCCASIONAL SHOWERS AND THUNDERSTORMS TO THE EASTERN CAROLINAS TONIGHT INTO TUESDAY. LOCALLY HEAVY RAINFALL IS EXPECTED. A WEAK FRONT WILL SLIDE EAST TO THE COAST WEDNESDAY...WITH DRIER AIR BEHIND THE FRONT LEADING TO REDUCED CHANCES OF SHOWERS AND STORMS LATER IN THE WEEK. NORTHEAST WINDS AROUND HIGH PRESSURE TO OUR NORTH WILL BRING SURPRISINGLY MILD TEMPERATURES THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 300 PM WEDNESDAY...SOMEWHAT COMPLICATED SETUP IN PLACE DUE TO THE JUXTAPOSITION OF LATE-SUMMERLIKE TROPICAL MOISTURE AND UPPER PIECES OF ENERGY USUALLY ONLY SEEN ON FRINGES OF SUMMER. MAIN VORT MAX CURRENTLY CLEARLY EVIDENT ON BOTH SAT AND RADAR NR CLT WITH BAND OF HEAVY SHOWERS/EMBEDDED THUNDERSTORMS ALONG ITS LEADING EDGE. THIS HEAVY RAIN WILL SWEEP THROUGH WESTERN COUNTIES OVER THE NEXT COUPLE OF HOURS. THEREAFTER COME A FEW POINTS OF FCST UNCERTAINTY. FOR ONE...SUBSIDENCE BEHIND THE MAIN VORT SHOULD SUPPRESS CONVECTION OVER WRN ZONES FOR NEXT SEVERAL HOURS AS THE VORT MOVES NE AND WEAKENS. SECOND...IT`LL BE INTERESTING TO SEE HOW THE TRAILING/TRAINING BAND OF SHOWERS PERSISTS AND HOW FAR EAST THEY PUSH. MODEL GUIDANCE NOT PERFORMING VERY WELL IN THE 1ST PLACE...BUT SUGGESTS THAT THE MAIN FORCING SHIFTS SOUTH OF THE REGION ASSOC WITH WEAK JETLET TRAILING THE VORT AS THE MAIN PIECE WEAKENS NEAR THE CAPE FEAR REGION. FOR WHAT ITS WORTH THE SRF IS RELUCTANT TO BRING SIGNIFICANT RAIN ASSOC WITH THIS FEATURE ALL THE WAY EAST TO COASTAL NC COUNTIES DUE TO THE UPPER FEATURE WEAKENING. GRANTED...THIS IS ALL JUST REALLY TRYING TO FINE-TUNE POPS...WITH THE LCL SO LOW/500-750M/AREA-WIDE AND THE COLUMN SATURATED THROUGH SUCH A DEEP LAYER VIRTUALLY EVERY LITTLE RIPPLE WILL BE ABLE TO GENERATE SHOWERS THAT WILL PUT DOWN APPRECIABLE RAINFALL. FORECAST THUS STILL BRINGS LIKELY POPS TO NC COAST THIS EVE. A RELATIVE LULL MAY OCCUR LATE EVENING INTO THE FIRST PART OF TONIGHT AS ALL OF THESE SHORTWAVES WEAKEN AND/OR MOVE EAST OUT OF THE AREA. FOCUS WILL THEN SHIFT TO THE IMMEDIATE COASTAL AREAS WHERE ANOTHER CHAIN OF SHEAR VORTS DEVELOP IN THE FLOW AND LEAD TO ASCENT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...A WET PATTERN WILL CONTINUE INTO TUESDAY WITH PRECIPITABLE WATER AT OR ABOVE 2.00 INCHES AND THE 500 MB TROUGH JUST TO OUR WEST. THE BULK OF THE RAINFALL TUESDAY MORNING SHOULD BE OFFSHORE PERHAPS AFFECTING THE BEACHES...BUT ACTIVITY WILL SHIFT BACK ONSHORE BY MID TO LATE MORNING WITH SLOW-MOVING HEAVY SHOWERS AND ISOLATED TSTMS EXPECTED TO SPREAD ALL THE WAY BACK INTO CENTRAL NC/SC BY EARLY AFTERNOON. PLENTY OF CLOUDS...A NEARLY SATURATED TROPOSPHERE...AND LITTLE VERTICAL WIND SHEAR SHOULD REDUCE OUR SEVERE WEATHER POTENTIAL AND LEAVE LOCALIZED RAINFALL- INDUCED FLOODING AS THE PRIMARY ADVERSE WEATHER POTENTIAL. ANTECEDENT CONDITIONS ARE NOT TREMENDOUSLY WET OVER THE EASTERN CAROLINAS: TS BERYL BROUGHT OUR LAST SIGNIFICANT RAINFALL EVENT OVER 10 DAYS AGO AND ONE-WEEK RAINFALL (NOT COUNTING TODAY) IS ONLY 5-25% OF NORMAL. FLOODING POTENTIAL IS NOT QUITE HIGH ENOUGH FOR A FLOOD WATCH AT THIS TIME...BUT WE WILL CONTINUE THE MENTION OF LOCALIZED FLOODING IN THE HAZARDOUS WEATHER OUTLOOK. THE 500 MB TROUGH SHOULD EASE ITS WAY TO THE COAST WEDNESDAY AFTERNOON WITH DRIER MID-LEVEL AIR (1.50 INCH PW) ADVECTING IN ON LIGHT NW/N WINDS ALOFT DURING THE DAY. THIS IS NEARLY THE SAME TIMING OF THE SURFACE COLD FRONT AS WELL. THIS SHOULD LEAD TO GRADUALLY DIMINISHING POPS WITH THE HIGHEST CHANCES OF SHOWERS AND STORMS WEDNESDAY ALONG THE COAST. THE GFS IS MUCH MORE BULLISH DEVELOPING SYNOPTIC LOW PRESSURE ALONG THE FRONT WEDNESDAY NIGHT WHICH WOULD BRING A SOMEWHAT STRONGER NE SURGE DOWN THE COAST WITH DRIER AND COOLER AIR PENETRATING FARTHER SOUTH INTO SOUTH CAROLINA. DIURNAL TEMPERATURE RANGES WILL BE RESTRICTED TUESDAY DUE TO CLOUDS AND RATHER WIDESPREAD SHOWER ACTIVITY. HIGH TEMPERATURES SHOULD BRIEFLY REACH 84-85 DEGREES ALTHOUGH THIS MIGHT BE FOR ONLY A FEW MINUTES IN BREAKS BETWEEN SHOWERS. AFTER A HUMID TUESDAY NIGHT WITH LOWS 69-73...SOMEWHAT DRIER CONDITIONS WEDNESDAY WILL ALLOW HIGHS INLAND TO REACH THE UPPER 80S. LOWS WEDNESDAY NIGHT SHOULD FALL TO 67-71...ALTHOUGH STRONGER COLD ADVECTION BEHIND OFFSHORE LOW PRESSURE AS ADVERTISED BY THE 12Z GFS COULD BRING SLIGHTLY COOLER READINGS. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 PM MONDAY...MEDIUM RANGE GUIDANCE CONTINUES TO ADVERTISE THE MID LEVEL PATTERN DEVELOPING INTO A OMEGA CONFIGURATION FOR THE WEEKEND. AT THE SURFACE...HIGH PRESSURE WILL BE THE FEATURE OF FOCUS FOR OUR AREA WITH THE RIDGE AXIS ALIGNED ALONG THE APPALACHIANS AS LOW PRESSURE REMAINS WELL OFFSHORE. THURSDAY AND FRIDAY SHOULD BE DRY. IT APPEARS ENOUGH MOISTURE POOLING OCCURS SATURDAY THROUGH MONDAY TO WARRANT NORTHEAST RESULTANT SEA BREEZE POPS. OPERATIONAL GFS/MEX NUMBERS ARE QUITE COOL AND OPTED FOR SLIGHTLY MODIFIED/WARMER HIGHS AND OVERNIGHT LOWS. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z...AIRMASS VERY JUICY WITH PRECIPITABLE WATER VALUES AROUND TWO INCHES. THIS CREATES MODERATE UNCERTAINTY WITH RESPECT TO TIMING OF CONVECTION. THE HRRR MODEL DID NOT INITIALIZE WELL WITH THE PRECIP OVER SOUTHEASTERN NORTH CAROLINA...SO IT MAY NOT HOLD WEIGHT FOR ACTIVITY THIS AFTERNOON. NEVERTHELESS...IT SHOWS AN AREA OF ACTIVE CONVECTION MOVING THROUGH THE CWA FROM WEST TO EAST THIS AFTERNOON...WEAKENING FOR DIURNAL REASONS AS IT NEARS THE COAST. VISIBILITIES COULD BRIEFLY GO DOWN TO IFR IN THE BRIEF HEAVY RAIN. OVERNIGHT...EXPECT CONVECTION TO WANE...BUT COULD NOT RULE OUT A SHOWER AT NEARLY ANY TIME. CEILINGS WILL REMAIN MVFR FOR THE MOST PART BUT COULD GO IFR INLAND TOWARD MORNING. TUESDAY...A FRONTAL BOUNDARY APPROACHES FROM THE WEST AS WELL AS A PRE FRONTAL TROUGH. CONVECTION IS EXPECTED...MAINLY FROM LATE MORNING ON. EXTENDED OUTLOOK...CHANCE FOR THUNDERSTORMS/IFR TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM MONDAY...HIGH PRESSURE MAINTAINS ITS PRESENCE OFF THE SOUTHEAST COAST THROUGH THE PERIOD ALTHOUGH IT IS A FAIRLY WEAK HIGH...ITS MAIN CENTER OFF THE COAST OF NEW ENGLAND AND NOVA SCOTIA. A PIEDMONT TROUGH WILL GRADUALLY DEVELOP DURING THE NEAR TERM HOWEVER AND ADD A FEW KNOTS OF WIND SPEED TO THE FCST. THIS BUMP IN WINDS PAIRED WITH THE SLIGHT INC IN SE SWELL ENERGY WILL YIELD A FORECAST OF 2 OR 3 TO 4 FT FORECAST FOR ALL ZONES. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 PM MONDAY...MODERATE SOUTH-SOUTHWEST WINDS ARE EXPECTED TUESDAY IN ADVANCE OF A COLD FRONT THAT WILL MAKE ITS WAY TO THE BEACHES DURING THE DAY WEDNESDAY. SLOW-MOVING HEAVY SHOWERS AND ISOLATED TSTMS WILL BE THE MAIN WEATHER STORY AHEAD OF THIS FRONT. ALTHOUGH IT IS ALWAYS DIFFICULT TO PREDICT WHERE BATCHES OF CONVECTION WILL BE MORE THAN A FEW HOURS IN THE FUTURE...MODEL TRENDS HINT AT THE BEST CHANCES ACROSS THE COASTAL WATERS TUESDAY MORNING...WITH PERHAPS A SECOND MAXIMUM IN COVERAGE LATE TUESDAY NIGHT. ONCE THE FRONT PUSHES OFFSHORE WEDNESDAY AFTERNOON WINDS WILL TURN NORTHEASTERLY...WITH CONSIDERABLE MODEL DISAGREEMENT CONCERNING WHETHER A NORTHEAST SURGE DEVELOPS WITH LOW PRESSURE DEVELOPING ALONG THE FRONT OFFSHORE. FOR NOW WE HAVE ONLY INCREASED FORECAST WIND SPEEDS INTO THE 10-15 KT RANGE...BUT THE 12Z GFS WOULD IMPLY SPEEDS IN THE 15-20 KT RANGE WEDNESDAY NIGHT...BUT STRONGER THAN THE 12Z NAM MODEL. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 PM MONDAY...NORTHEASTERLY FLOW WILL PREVAIL THROUGH THE PERIOD AS SURFACE HIGH PRESSURE AXIS IS SITUATED ALONG THE APPALACHIANS. WIND SPEEDS WILL HOVER IN A RANGE OF 10-15 KNOTS PROBABLY CLOSER TO THE LOWER RANGE MOST OF THE TIME. CAVEAT TO THE FORECAST WITH THIS TYPE OF SYNOPTIC SCENARIO IS THE EMBEDDED NUMEROUS SURGES WHICH ARE ALL BUT IMPOSSIBLE TO RECONCILE THIS FAR OUT IN TIME. SEAS WILL HOVER IN A RANGE OF 2-4 FEET THURSDAY AND FRIDAY INCREASING TO 3-5 FEET AND POSSIBLY HIGHER INTO FLAG CRITERIA SATURDAY AS THE FETCH PERSISTS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...TRA NEAR TERM...MBB SHORT TERM...TRA LONG TERM...SHK AVIATION...MBB/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
140 PM EDT MON JUN 11 2012 .SYNOPSIS... SHOWERS AND THUNDERSTORMS WITH TORRENTIAL DOWNPOURS WILL BE ON THE INCREASE INTO WEDNESDAY AS TROPICAL MOISTURE FEEDS NORTH AHEAD OF A SLOW-MOVING COLD FRONT. THIS FRONT WILL MOVE ACROSS THE AREA ON WEDNESDAY. HIGH PRESSURE WILL BUILD DOWN FROM THE GREAT LAKES THURSDAY AND PERSIST THROUGH THE WEEKEND AS LOW PRESSURE DEVELOPS OFF THE COAST OF CAPE HATTERAS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM WEDNESDAY...NOT MUCH TO CHANGE AT THIS POINT...JUST TRYING TO PIN DOWN BEST LOCATION AND TIMING OF PRECIP CHANCES. AGREE WITH PREV FCST THAT MAIN AREA OF RAINFALL WILL MOVE IN FROM THE WEST...THE BAND OF SHOWERS CURRENTLY CROSSING THE SAVANNAH RIVER. A FEW SMALLER SCALE BANDS OF SHALLOW CONVECTION HAVE BROKEN OUT ALONG APPARENT DIFFERENTIAL HEATING BOUNDARIES...AND THERE IS NO REASON TO THINK THAT THEY WILL NOT CONTINUE. SUCH FEATURES WILL BE TOUGH TO TIME BUT ALSO NOT LEAD TO VERY APPRECIABLE PRECIP AMOUNTS. PREVIOUS DISCUSSION... AS OF 6 AM MONDAY...A TROPICAL MOISTURE FEED EXTENDING FROM NEAR THE BAY OF CAMPECHE AND UP THROUGH THE SOUTHEASTERN STATES WILL INCREASE THE PROBABILITY OF SHOWERS AND THUNDERSTORMS AND HEAVY DOWNPOURS THIS PERIOD AS A MID-LEVEL RIDGE SLOWLY EXITS THE EASTERN CAROLINAS AND A SLOW MOVING TROUGH TO OUR W CONTINUES TO APPROACH. PRECIPITABLE WATER VALUES WILL TOP 2 INCHES AS SSW TO SW LOW LEVEL JET INCREASES TO 25 TO 30 KT...HIGHEST INLAND FROM THE COAST. MODEST ISENTROPIC UPGLIDE WILL REMAIN THROUGH THE PERIOD. A WEAK MID-LEVEL SHORTWAVE TROUGH WILL ADD LIFT AS IT APPROACHES FROM THE SW LATE TONIGHT. HARD TO RULE OUT PRECIPITATION AT ANY POINT THIS PERIOD. WILL TREND POPS HIGHER THROUGH THE DAY AND ESPECIALLY TONIGHT AS LOW LEVEL JETTING AND LIFT INCREASES. THE POTENTIAL FOR SIGNIFICANT RAINFALL IS THERE GIVEN THE DEEP... NEARLY SATURATED LAYER THAT DEVELOPS FROM NEAR THE SURFACE THROUGH 20 KFT...MOST PRONOUNCED INLAND. THIS WILL BE ESPECIALLY TRUE LATE IN THE PERIOD SHOULD CELLS BEGIN TO TRAIN OVER THE SAME GENERAL AREA. AT THIS TIME...HIGHEST QPF VALUES THIS PERIOD ARE EXPECTED NEAR THE I-95 CORRIDOR WHERE AMOUNTS COULD REACH 1 TO 2 INCHES. AS YOU NEAR THE COAST...AMOUNTS SHOULD GENERALLY BE LOWER...ESPECIALLY ACROSS THE CAPE FEAR REGION WHERE RIDGING WILL ACQUIESCE LAST AND AS A RESULT POPS WILL BE LOWEST. DIURNAL RANGE SHOULD BE LIMITED DUE TO DEEP MOISTURE AND ABUNDANCE OF CLOUD COVER. HIGHS WILL BE ABOUT TO SLIGHTLY BELOW NORMAL. LOWS WILL BE ABOVE NORMAL...LOWER TO MID 70S. IT WILL FEEL RATHER HUMID THROUGH THE PERIOD WITH DEWPOINTS AS HIGH AS THE LOWER 70S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY... DEEP MOIST SOUTHERLY FLOW WILL BE IN PLACE ON TUESDAY AHEAD OF AN APPROACHING COLD FRONT. MEANWHILE SHORTWAVE TROUGH TRACKING UP FROM THE GULF COAST WILL MOVE EAST ACROSS THE CAROLINAS TUES INTO WED AS A NORTHERN STREAM TROUGH PUSHES THIS COLD FRONT EAST INTO AND THROUGH THE COASTAL CAROLINAS WED. THE H5 TROUGH WILL PROVIDE ENHANCED SUPPORT FOR SHWR/TSTM ACTIVITY IN A MOIST AND UNSTABLE ENVIRONMENT. GFS/NAM SHOWING BEST LIFT AND MOISTURE TUES AFTN THROUGH TUES NIGHT AND SHIFTING OFF THE COAST BY WED AFTN. PCP WATER VALUES INCREASE UP TO 2.25 INCHES AHEAD AND ALONG COLD FRONT TUES AFTN THROUGH TUES NIGHT. GFS SHOWS MORE OF A CLEAN PASSAGE OF FRONT EARLY WED BUT NAM SHOWS SEA BREEZE KICKING IN ON WED WITH MOISTURE LINGERING ALONG THE COAST AND HOLDING OFF FROPA UNTIL LATER IN THE DAY. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3 AM MONDAY...MODELS CONTINUE TO SHOW DEVELOPING LOW PRESSURE OFF THE HATTERAS COAST ON THURS. THIS MAY HELP TO THROW AROUND SOME MOISTURE ON BACK END...BUT OVERALL EXPECT DRIER HIGH PRESSURE TO BUILD DOWN FROM THE GREAT LAKES INTO THE CAROLINAS THURS THROUGH THE WEEKEND. IN THE MID TO UPPER LEVELS...H5 RIDGE BUILDS UP THROUGH THE GREAT LAKES HEADING INTO THE WEEKEND WHILE MID TO UPPER TROUGH MAY DIG SOUTHWESTWARD FROM THE ATLANTIC WATERS PRODUCING SOME UNCERTAINTY OVER THE WEEKEND. FOR NOW WILL SHOW DRIER AIR BUILDING IN FOR THURS BUT WILL ADD SOME LOW END POPS BACK IN FORECAST MAINLY OVER COASTAL WATERS AND JUST ALONG THE COAST FRI THROUGH THE WEEKEND DUE TO UNCERTAINTY WITH THIS LOW. TEMPS WILL RUN INTO THE 80S DURING THE DAY AND IN THE 60S AT NIGHT. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z...AIRMASS VERY JUICY WITH PRECIPITABLE WATER VALUES AROUND TWO INCHES. THIS CREATES MODERATE UNCERTAINTY WITH RESPECT TO TIMING OF CONVECTION. THE HRRR MODEL DID NOT INITIALIZE WELL WITH THE PRECIP OVER SOUTHEASTERN NORTH CAROLINA...SO IT MAY NOT HOLD WEIGHT FOR ACTIVITY THIS AFTERNOON. NEVERTHELESS...IT SHOWS AN AREA OF ACTIVE CONVECTION MOVING THROUGH THE CWA FROM WEST TO EAST THIS AFTERNOON...WEAKENING FOR DIURNAL REASONS AS IT NEARS THE COAST. VISIBILITIES COULD BRIEFLY GO DOWN TO IFR IN THE BRIEF HEAVY RAIN. OVERNIGHT...EXPECT CONVECTION TO WANE...BUT COULD NOT RULE OUT A SHOWER AT NEARLY ANY TIME. CEILINGS WILL REMAIN MVFR FOR THE MOST PART BUT COULD GO IFR INLAND TOWARD MORNING. TUESDAY...A FRONTAL BOUNDARY APPROACHES FROM THE WEST AS WELL AS A PRE FRONTAL TROUGH. CONVECTION IS EXPECTED...MAINLY FROM LATE MORNING ON. EXTENDED OUTLOOK...CHANCE FOR THUNDERSTORMS/IFR TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM MONDAY...FAIRLY STEAD SET OF CONDITIONS THROUGH THE DAY TO BRING QUIET WEATHER FOR THE MOST PART. SOME LOW LEVEL JETTING WILL DEVELOP OVER THE LANDMASS...THE COASTAL WATERS WILL BE ON THE EASTERN PERIPHERY OF THIS JET LEADING TO A FEW KTS INCREASE IN SSWRLY FLOW. SEAS 2.5 TO 3 FT AT THE BUOYS WITH PEAK PD AT 5 SEC. A SMALL 10 SEC SWELL SHOWING UP AS WELL. BOTH WAVE COMPONENTS WILL CONTINUE AS-IS THROUGH THE PERIOD. PREVIOUS DISCUSSION... AS OF 6 AM MONDAY...A SOUTH TO SSW FLOW WILL REMAIN ACROSS THE WATERS AHEAD OF A SLOW MOVING TROUGH APPROACHING FROM THE W. LOW LEVEL JETTING THIS PERIOD WILL BE STRONGEST LATE TONIGHT WHEN WINDS COULD REACH 15 TO 20 KT. SEAS WILL HOLD IN THE 2 TO 4 FT RANGE THROUGH THE DAY WITH PERHAPS SOME 5 FOOTERS CREEPING INTO THE OUTERMOST WATERS LATE TONIGHT AS WINDS BEGIN TO INCREASE. A 9 TO 10 SECOND SE SWELL WILL PERSIST THROUGH THE PERIOD. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...GRADIENT TIGHTENS AS COLD FRONT MOVES THROUGH THE CAROLINAS TUES INTO WED. SOUTHERLY WINDS WILL REACH UP TO 20 KTS AHEAD OF THE FRONT. THIS WILL PUSH SEAS UP TO 3 TO 5 FT LATE TUES. THE COLD FRONT SHOULD CLEAR THE COASTAL WATERS ON WED WITH NORTHERLY FLOW DEVELOPING BEHIND IT. THE DIMINISHING OFF SHORE FLOW WILL ALLOW SEAS TO RELAX DOWN TO 3 FT OR LESS BY WED NIGHT. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 AM MONDAY...LIGHT NORTHERLY FLOW AROUND 10 TO 15 KTS ON THURSDAY MAY INCREASE UP TO 15 TO 20 KTS ON FRIDAY AS GRADIENT TIGHTENS BETWEEN HIGH PRESSURE BUILDING DOWN FROM THE GREAT LAKES AND LOW PRESSURE DEVELOPING OFF THE HATTERAS COAST. SEAS MAY INCREASE UP TO 4 TO 5 FT IN THE OUTER WATERS FRI INTO TE WEEKEND AND POSSIBLY HIGHER IF LOW PRESSURE DEEPENS OFF THE COAST. THERE IS SOME UNCERTAINTY AS TO THE STRENGTH AND LOCATION OF THIS DEVELOPING LOW PRESSURE OFF THE CAROLINA COAST HEADING INTO THE WEEKEND AND THEREFORE WILL REMAIN MORE CONSERVATIVE WITH SEA HEIGHTS FOR NOW. WNA MODEL SHOWS SEAS SHOOTING UP ON FRI TO NEAR SCA THRESHOLDS IN OUTER WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...MBB SHORT TERM...RGZ LONG TERM...RGZ AVIATION...43
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
342 PM EDT MON JUN 11 2012 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS THE FORECAST AREA LATE TONIGHT AND TUESDAY MORNING. HIGH PRESSURE WILL BUILD IN OVER THE GREAT LAKES WEDNESDAY AND THEN MOVE SLOWLY EAST THROUGH THE REST OF THE WORK WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... A VERY TOUGH FORECAST MAINLY TO DO WITH THE COVERAGE. SOME LIGHT SHOWERS WILL EXIT THE NORTHEAST PORTION OF THE FORECAST AREA THIS EVENING. SOME OF THE MODELS TRY TO INDICATE MORE SHOWERS AND THUNDERSTORMS DEVELOPING OVER THE EXTREME EASTERN PORTION OF THE FORECAST AREA LATE THIS EVENING. WENT ALONG WITH THAT BUT VERY MUCH ON THE EDGE. FOR NORTHWEST OHIO...SOME SHOWERS AND THUNDERSTORMS DEVELOPING OVER SOUTHWEST OHIO THAT WILL MOVE NORTHEAST THIS EVENING. THE MCS OVER MISSOURI AND ILLINOIS DOESN`T SEEM LIKE IT WILL BE A PROBLEM FOR THE AREA. THE HRRR TRIES TO DEVELOP THIS...WHICH MAY BE OK WITH A SHORT WAVE MOVING ACROSS THE REGION TONIGHT WITH THE COLD FRONT. ON THE EDGE ABOUT HOW MUCH THUNDER ACTIVITY WILL OCCUR WITH THE AIRMASS NOT THAT UNSTABLE. QPF AMOUNTS SHOULD NOT BE THAT HIGH...WILL HAVE TO WATCH ANY SLOW MOVING CONVECTION. WENT TOWARD THE WARMER GUIDANCE FOR LOWS BECAUSE OF CLOUDS AND NOT WIDESPREAD PRECIPITATION. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... ON THE EDGE HOW MUCH ACTIVITY WILL OCCUR TUESDAY WITH THE FRONT MOVING THROUGH BY EARLY AFTERNOON. FOLLOWED PREVIOUS FORECAST WHICH SEEMED REASONABLE. CLOUDS SHOULD DECREASE FROM THE WEST. OTHERWISE HIGH PRESSURE BUILDING IN FOR THE REMAINDER OF THE PERIOD. THE LAKE AND 850 MB TEMPERATURE DIFFERENCE SHOULD NOT BE THAT EXTREME TO CAUSE LAKE EFFECT OR LAKE INDUCED CLOUDS... EXCEPT MAY BE AROUND DAYBREAK WEDNESDAY WHEN THE DIFFERENCE WILL BE NEAR 10 C. USED A BLEND OF GUIDANCE FOR THE LOWS AND HIGHS. TENDED TOWARD COOLER ESPECIALLY FOR NIGHT TIME READINGS. && .LONG TERM /FRIDAY THROUGH MONDAY/... FOR THOSE WANTING RAIN...THIS IS NOT A GOOD LONG TERM FORECAST. RIDGE REMAINS NEARLY STATIONARY OVER THE REGION. MUCH OF THE HEAT WILL BE TO OUR WEST THROUGH THE WEEKEND SO OUR TEMPERATURES SHOULD BE IN THE 80S. POSSIBLY A LITTLE WARMER EARLY NEXT WEEK IF THE RIDGE SHIFTS A LITTLE MORE EAST. HAVE GONE A FEW DEGREES ABOVE GUIDANCE SINCE LATELY WE HAVE BEEN WARMING BETTER THAN THE CLIMO WEIGHTED GUIDANCE IS SUGGESTING. WE ARE GETTING DRIER AND WE HAVE A LONG JUNE DAY TO WARM. AFTERNOON POP-UP SHOWER/TS CHANCES DO NOT EVEN LOOK THAT GOOD. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... LIGHT SHOWERS SLOW TO MOVE INTO CENTRAL AND EASTERN PORTIONS OF THE AREA...BUT THEY WILL. MVFR CEILINGS ASSOCIATED WITH THESE SHOWERS. CU HAVE GOTTEN A LITTLE BUBBLY OVER INDIANA AND TOL/FDY MAY SEE AN ISOLATED TS AROUND THIS AFTERNOON. A LOT OF QUESTION AS TO WHAT WILL DEVELOP THIS EVENING/OVERNIGHT. WILL STILL HAVE A CHANCE OF SOME EMBEDDED TS AND SCATTERED SHOWERS WITH THE COLD FRONT MAKING ITS WAY ACROSS THE AREA TOWARD SUNRISE/EARLY MORNING. SOME GUIDANCE IS WANTING TO GO AS LOW AS IFR WITH VSBY AND/OR CIGS OVERNIGHT. NOT SURE SO HAVE GONE WITH A MORE CONSERVATIVE MVFR OVERNIGHT. CLEARING TUESDAY MORNING/EARLY AFTERNOON. SOUTH FLOW THROUGH TONIGHT...WEST-NORTHWEST TUESDAY AFTER THE FRONT. .OUTLOOK...NON VFR...NONE. && .MARINE... LAKE LOOKS LIKE IT WILL GET MIXED UP OVER THE NEXT FEW DAYS AS COLD AIR ADVECTION NORTHERLY FLOW DEVELOPS. LOOKING AT POSSIBLE SMALL CRAFT ADVISORIES BY TUESDAY NIGHT. THE EVENT WILL BE SHORT LIVED AS WINDS BEGIN TO DIMINISH ON WEDNESDAY. HIGH PRESSURE FINALLY BECOMES STATIONARY OVER THE EAST COAST AND SETS UP A LIGHT SOUTHERLY COMPONENT TO THE WIND. GENERALLY LIGHT FLOW IS EXPECTED THROUGH THE REST OF THE PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KIELTYKA NEAR TERM...KIELTYKA SHORT TERM...KIELTYKA LONG TERM...OUDEMAN AVIATION...OUDEMAN MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS NORMAN OK
428 PM CDT MON JUN 11 2012 .DISCUSSION... THE BIGGEST CHALLENGES ARE SEVERE THUNDERSTORM AND RAIN CHANCES THROUGH WEDNESDAY. THROUGH 10 PM CDT TONIGHT...BELIEVE THE BEST CHANCES FOR SEVERE STORMS WILL OVER WESTERN NORTH TEXAS AND POSSIBLY FAR SOUTHERN OKLAHOMA NEAR A SURFACE BOUNDARY...WHERE KEPT 20/30 PERCENT CHANCES. STORMS WERE DEVELOPING NEAR ABILENE TEXAS WHERE THE CAP HAS BEEN BROKEN AND WILL MOVE EAST AND POSSIBLY NORTHEAST. WITH THE AIR BEING UNSTABLE WITH SOME SHEAR...THINK LARGE HAIL...POSSIBLY AS LARGE AS BASEBALLS...AND DAMAGING WIND OF 65 MPH OR GREATER WILL BE THE MAIN HAZARDS. MOST OF THESE STORMS WILL STAY SOUTH OF THE FORECAST AREA. NOTICED THE LATEST HRRR RUNS INDICATED ISOLATED DEVELOPMENT EAST OF I-35...SO KEPT 20 PERCENT IN THESE AREAS...THOUGH CONFIDENCE OF DEVELOPMENT REMAINS QUITE LOW DUE TO STRONG CAPPING. AFTER 10 PM CDT TONIGHT...KEPT RAIN CHANCES SOUTH OF A CLINTON TO OKLAHOMA CITY TO SWEETWATER LINE. ADDITIONAL STORMS MAY DEVELOP NEAR THE LINE MENTIONED ABOVE BETWEEN 10 PM AND 4 AM AS LATEST MODELS INDICATED THE MID LEVEL CAP WEAKENING WITH 700 MB TEMPERATURES COOLING TO +9/10C. WITH ABUNDANT INSTABILITY AND A GOOD AMOUNT OF SHEAR...A FEW STORMS MAY BE SEVERE WITH LARGE HAIL...POSSIBLY VERY LARGE...AND DAMAGING WIND. THE FOCUS FOR LIFT APPEARS TO BE WEAK...SO WIDESPREAD SEVERE SEEMS UNLIKELY. LOCALLY HEAVY RAINFALL MAY BE POSSIBLE AS WELL. TUESDAY...KEPT RAIN CHANCES ACROSS MUCH OF THE AREA WITH THE HIGHEST CHANCES OVER SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS WHERE BEST MOISTURE AND INSTABILITY ARE FORECAST. SOME STORMS MAY BE SEVERE WITH LARGE HAIL AND DAMAGING WIND...MAINLY DURING THE LATE AFTERNOON AND EVENING HOURS...THOUGH LARGE HAIL THREAT MAY BE LOWER COMPARED TO TONIGHT. WEDNESDAY INTO THURSDAY...KEPT LOWER CHANCES FOR SHOWERS AND STORMS OVER THE AREA. CANNOT RULE OUT A FEW SEVERE STORMS BOTH DAYS. FRIDAY THROUGH NEXT MONDAY...HOTTER AND DRIER WEATHER IS EXPECTED. A FEW STORMS MAY BE POSSIBLE DURING THIS TIME FRAME...BUT DID NOT MENTION DUE TO LOW CONFIDENCE. MBS && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 68 85 66 86 / 20 20 40 30 HOBART OK 64 87 67 89 / 20 40 40 30 WICHITA FALLS TX 69 88 71 91 / 40 30 50 30 GAGE OK 55 84 62 88 / 0 20 40 30 PONCA CITY OK 60 86 61 86 / 0 0 20 30 DURANT OK 71 87 70 88 / 50 30 40 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 02/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
401 PM EDT MON JUN 11 2012 .SYNOPSIS... A FRONTAL SYSTEM WILL APPROACH FROM THE WEST AND GENERATE WIDESPREAD SHOWERS AND THUNDERSTORMS FOR LATE TONIGHT AND TUESDAY. THE COLD FRONT WILL PASS THROUGH TUESDAY NIGHT. THIS FRONT MAY STALL OUT NEAR THE MID ATLANTIC COAST FOR THE MIDDLE AND LATTER PART OF THIS WEEK DELAYING THE EXIT OF CLOUDS AND SHOWERS OUT OF THE EASTERN HALF OF PENNSYLVANIA. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... MSTR ALOFT IS THICKENING UP AND DIURNAL CU IS FORMING/FILLING IN. THE LOW CRUD IN THE EAST IS GONE. THICKER LINE OF CU FORMING FROM YORK TO STATE COLLEGE COULD MAKE ISOLD SHRA BEFORE SUNSET. THE MESO MDLS LIKE THE HRRR AND RUC DO GENERATE SOME RAINFALL THROUGH THE CONVECTIVE PARAM. SHOWERS ALSO MOVING THRU FAR WRN PA HAVE A DISTINCT LACK OF LTG DESPITE LOW STABILITY. EXPECT THESE SHOWERS TO SLIDE TO THE WEST AND AFFECT THE FAR WRN ZONES THIS EVENING. RAIN WILL NOT BE HEAVY AT ALL...WITH JUST A TENTH OR SO BEFORE MIDNIGHT. WILL STILL MENTION SLIGHT CHC T FOR THE REGION WITH STABILITY LOW. MOST OF THE PRECIP WILL WAIT UNTIL AFTER MIDNIGHT WHEN THE HEIGHTS START TO DROP FASTER. PWATS CLIMB MORE THAN AN INCH THRU SUNRISE AND THE MDL SOUNDINGS DECIDEDLY MOIST-ADIABATIC FOR LATER TONIGHT...SO HEAVY RAIN FROM ANY CONVECTION IS POSSIBLE. SKY COVER WILL BECOME 100PCT THIS EVENING AND EARLY TONIGHT. THUS...TEMPS SHOULD NOT FALL FAR BELOW THE MID 60S. FFG AND FFH NUMBERS ARE PRETTY LOFTY - ON THE ORDER OF 2.5 TO 3.5 INCHES IN 3 HRS...SO IT WOULD NEED TO BE MUCH HEAVIER RAIN THAN EXPECTED TO CREATE FLOODING PROBLEMS. THE DURATION OF THE EVENT AND PROGRESSIVE NATURE OF THE TROUGH AND FRONT ARGUE AGAINST ANY FLOOD WATCHES. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... CATEGORICAL POPS ARE STILL IN ORDER THROUGH ALL OF TUESDAY AND INTO TUESDAY EVENING. STABLE PRECIP SHOULD DOMINATE OVER CONVECTIVE FORCING. LLJET IS NOT STRONG AT ALL. SHEAR ALSO ONLY WEAK TO MODERATE. HOWEVER...SPC DOES MENTION THE AREA IN THE DAY2 OUTLOOK. WILL KEEP THE MENTION OF THUNDER IN BUT FOREGO MENTIONS OF GUSTY WINDS OR HAIL. I THINK IT WILL BE HARD TO GET THE CLOUDS OUT OF THE WAY LONG ENOUGH AND MATCH UP THE TIMING OF UPPER FORCING OR THE COLD FRONT WITH THAT POSSIBLE WINDOW OF STRONGER SFC HEATING AND DESTABILIZATION. THE HIGH PRECIP WATER WILL NOT BE TAPPED VERY EFFECTIVELY WITHOUT WIDESPREAD UPRIGHT CONVECTION TO TAP INTO IT. OVERALL...A GENERAL 1 INCH OF PRECIP IS LOOKING LIKE THE STORM TOTAL. EXPECT SLIGHTLY LOWER AMOUNTS TO THE WEST AND HIGHER AMOUNTS IN THE EAST. AGAIN...THOSE AMOUNTS SHOULD NOT RAISE EYEBROWS WITH VEGETATION FULLY GROWN AND STREAM FLOWS AROUND NORMAL. TIMING OF THE FROPA LOOKS LIKE IT WILL BE A BIT QUICKER THAN PREV FCSTS...WITH WINDS SHIFTING TO THE WEST LATE TUES AFTN IN THE WEST AND IN THE EAST BY MIDNIGHT. THUS...WILL KEEP POPS HIGH FOR THE DAYLIGHT HRS...BUT TAPER THEM OFF COMPLETELY FROM WEST TO EAST BEFORE SUNRISE WED. THE FRONT ITSELF WILL HANG BACK BEHIND THE MAIN SHIELD OF PRECIP AND GENERATE SOME LOW-TOPPED SHOWERS AS IT MOVES THROUGH. MAXES WILL BE IN THE 70S OVERALL WITHOUT SIG BREAKS IN THE SKY COVER. DRY AIR FINALLY WORKS IN TO THE WEST TUES NIGHT AS THE STRONGEST SHORT WAVE PUSHES THROUGH. CLEARING - IN THE WEST AT LEAST - MAY ALLOW FOG TO FORM AS TEMPS DIP CLOSE TO 50 IN THE WRN MTS AND MID 50S TO NEAR 60 IN THE CENTRAL AND EAST. BUT WIND AND DRYING AIRMASS MAY NEGATE THAT AS WELL. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... THE CFRONTAL BOUNDARY WILL HAVE PUSHED THE DEEP MOISTURE EAST OF THE AREA TO BEGIN THE PERIOD. HOWEVER...AN UPPER LOW FCST TO CUT- OFF OVER THE NORTH ATLANTIC /FOLLOWED BY A DEVELOPING REX BLOCK/ MAY HOLD THE BOUNDARY/TROFFINESS ALONG THE MID ATLANTIC SEABOARD FOR SEVERAL DAYS MORE. THIS WILL KEEP AT LEAST A LOW POTENTIAL FOR SOME SHOWERS AND COOLER TEMPERATURES ACROSS THE EASTERN PARTS OF CENTRAL PA...AS A SLIGHTLY ANOMALOUS LLVL EASTERLY FLOW DEVELOPS THURSDAY INTO FRIDAY WITH THE CENTER OF HIGH PRESSURE SLIDING BY ACROSS SRN ONTARIO. LATEST LONG TERM GUIDANCE HAS FLOPPED BACK TO A DRIER SOLUTION THAT WHAT WAS SHOWN YESTERDAY WITH REGARD CLOUDS/SHOWERS BEING SLOW TO CLEAR OVER EASTERN PA. HOWEVER...SOLUTIONS ARE NOT COMPLETELY DRY...THUS THIS APPEARS TO THE MAIN FORECAST PROBLEM IN THE LONG TERM PERIOD. UPPER RIDGING IS STILL FORECAST TO BUILD INTO THE MIDWEST/OHIO VALLEY LATE IN THE WEEK /LED SEVERAL HUNDRED KM BY A 1024 MB SFC HIGH/...LIKELY BRINGING ANOTHER SUMMER-LIKE PERIOD LATER IN THE EXTENDED. HOWEVER...WITH THE CENTER OF THE RIDGE SITUATED FROM THE MID MISS VALLEY TO LAKE MICHIGAN...AND SLOW RETROGRADE OF THE NORTH ATLC UPPER LOW...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO TEMPS...THE DISTRIBUTION OF CLOUD COVER...THE CHANCE FOR DIURNAL CONVECTION ACROSS THE EASTERN HALF OF PENN LATE IN THE WEEK AND INTO THE UPCOMING WEEKEND. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... CLOUDS WILL CONTINUE TO THICKEN AND LOWER INTO THIS EVENING...IN ADVANCE OF COLD FRONT APPROACHING FROM THE MIDWEST. AN UPPER LEVEL DISTURBANCE LIFTING NWD ALONG THE APPALACHIANS AND COULD TRIGGER ISOLD-SCT SHOWER OR TSTM OVER S/W PA THROUGH THIS EVE. THE MAIN UPPER TROUGH SWINGS ACROSS THE GREAT LAKES LATER TONIGHT INTO TUES...PUSHING THE COLD FRONT THROUGH CENTRAL PA. EXPECT SHRA TO INCREASE IN CVRG/INTENSITY AND SPREAD EASTWARD OVERNIGHT INTO TUES...BEFORE TAPERING OFF FROM WEST TO EAST TUES NGT. MOIST S-SE LOW LEVEL FLOW WILL SUPPORT LOW MVFR TO IFR CIGS...WITH VIS FLUCTUATIONS IN MOD TO OCNLY HVY SHRA/TSRA. ONCE THE FRONT PULLS EAST OF THE REGION...THE REMAINDER OF THE WEEK /WED-SAT/ LOOKS RELATIVELY QUIET AS HIGH PRESSURE BUILDS INTO THE NE UNITED STATES. OUTLOOK... WED-FRI...GENERALLY VFR. ISOLD SHRA/TSRA POSSIBLE EACH AFTN. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...LAMBERT/GARTNER AVIATION...EVANEGO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
241 PM EDT MON JUN 11 2012 .SYNOPSIS... A FRONTAL SYSTEM WILL APPROACH FROM THE WEST AND GENERATE WIDESPREAD SHOWERS AND THUNDERSTORMS FOR LATE TONIGHT AND TUESDAY. THE COLD FRONT WILL PASS THROUGH TUESDAY NIGHT. THIS FRONT MAY STALL OUT NEAR THE MID ATLANTIC COAST FOR THE MIDDLE AND LATTER PART OF THIS WEEK DELAYING THE EXIT OF CLOUDS AND SHOWERS OUT OF THE EASTERN HALF OF PENNSYLVANIA. && .NEAR TERM /THROUGH TONIGHT/... MSTR ALOFT IS THICKENING UP AND DIURNAL CU IS FORMING/FILLING IN. THE LOW CRUD IN THE EAST IS GONE. THICKER LINE OF CU FORMING FROM YORK TO STATE COLLEGE COULD MAKE ISOLD SHRA BEFORE SUNSET. THE MESO MDLS LIKE THE HRRR AND RUC DO GENERATE SOME RAINFALL THROUGH THE CONVECTIVE PARAM. SHOWERS ALSO MOVING THRU FAR WRN PA HAVE A DISTINCT LACK OF LTG DESPITE LOW STABILITY. EXPECT THESE SHOWERS TO SLIDE TO THE WEST AND AFFECT THE FAR WRN ZONES THIS EVENING. RAIN WILL NOT BE HEAVY AT ALL...WITH JUST A TENTH OR SO BEFORE MIDNIGHT. WILL STILL MENTION SLIGHT CHC T FOR THE REGION WITH STABILITY LOW. MOST OF THE PRECIP WILL WAIT UNTIL AFTER MIDNIGHT WHEN THE HEIGHTS START TO DROP FASTER. PWATS CLIMB MORE THAN AN INCH THRU SUNRISE AND THE MDL SOUNDINGS DECIDEDLY MOIST-ADIABATIC FOR LATER TONIGHT...SO HEAVY RAIN FROM ANY CONVECTION IS POSSIBLE. SKY COVER WILL BECOME 100PCT THIS EVENING AND EARLY TONIGHT. THUS...TEMPS SHOULD NOT FALL FAR BELOW THE MID 60S. FFG AND FFH NUMBERS ARE PRETTY LOFTY - ON THE ORDER OF 2.5 TO 3.5 INCHES IN 3 HRS...SO IT WOULD NEED TO BE MUCH HEAVIER RAIN THAN EXPECTED TO CREATE FLOODING PROBLEMS. THE DURATION OF THE EVENT AND PROGRESSIVE NATURE OF THE TROUGH AND FRONT ARGUE AGAINST ANY FLOOD WATCHES. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... CATEGORICAL POPS ARE STILL IN ORDER THROUGH ALL OF TUESDAY AND INTO TUESDAY EVENING. STABLE PRECIP SHOULD DOMINATE OVER CONVECTIVE FORCING. LLJET IS NOT STRONG AT ALL. SHEAR ALSO ONLY WEAK TO MODERATE. HOWEVER...SPC DOES MENTION THE AREA IN THE DAY2 OUTLOOK. WILL KEEP THE MENTION OF THUNDER IN BUT FOREGO MENTIONS OF GUSTY WINDS OR HAIL. I THINK IT WILL BE HARD TO GET THE CLOUDS OUT OF THE WAY LONG ENOUGH AND MATCH UP THE TIMING OF UPPER FORCING OR THE COLD FRONT WITH THAT POSSIBLE WINDOW OF STRONGER SFC HEATING AND DESTABILIZATION. THE HIGH PRECIP WATER WILL NOT BE TAPPED VERY EFFECTIVELY WITHOUT WIDESPREAD UPRIGHT CONVECTION TO TAP INTO IT. OVERALL...A GENERAL 1 INCH OF PRECIP IS LOOKING LIKE THE STORM TOTAL. EXPECT SLIGHTLY LOWER AMOUNTS TO THE WEST AND HIGHER AMOUNTS IN THE EAST. AGAIN...THOSE AMOUNTS SHOULD NOT RAISE EYEBROWS WITH VEGETATION FULLY GROWN AND STREAM FLOWS AROUND NORMAL. TIMING OF THE FROPA LOOKS LIKE IT WILL BE A BIT QUICKER THAN PREV FCSTS...WITH WINDS SHIFTING TO THE WEST LATE TUES AFTN IN THE WEST AND IN THE EAST BY MIDNIGHT. THUS...WILL KEEP POPS HIGH FOR THE DAYLIGHT HRS...BUT TAPER THEM OFF COMPLETELY FROM WEST TO EAST BEFORE SUNRISE WED. THE FRONT ITSELF WILL HANG BACK BEHIND THE MAIN SHIELD OF PRECIP AND GENERATE SOME LOW-TOPPED SHOWERS AS IT MOVES THROUGH. MAXES WILL BE IN THE 70S OVERALL WITHOUT SIG BREAKS IN THE SKY COVER. DRY AIR FINALLY WORKS IN TO THE WEST TUES NIGHT AS THE STRONGEST SHORT WAVE PUSHES THROUGH. CLEARING - IN THE WEST AT LEAST - MAY ALLOW FOG TO FORM AS TEMPS DIP CLOSE TO 50 IN THE WRN MTS AND MID 50S TO NEAR 60 IN THE CENTRAL AND EAST. BUT WIND AND DRYING AIRMASS MAY NEGATE THAT AS WELL. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... THE CFRONTAL BOUNDARY WILL HAVE PUSHED THE DEEP MOISTURE EAST OF THE AREA TO BEGIN THE PERIOD. HOWEVER...AN UPPER LOW FCST TO CUT-OFF OVER THE NORTH ATLANTIC /FOLLOWED BY A DEVELOPING REX BLOCK/ MAY HOLD THE BOUNDARY/TROFFINESS ALONG THE MID ATLANTIC SEABOARD FOR SEVERAL DAYS MORE. THIS WILL KEEP AT LEAST A LOW POTENTIAL FOR SOME SHOWERS AND COOLER TEMPERATURES ACROSS THE EASTERN PARTS OF CENTRAL PA...AS A SLIGHTLY ANOMALOUS LLVL EASTERLY FLOW DEVELOPS THURSDAY INTO FRIDAY WITH THE CENTER OF HIGH PRESSURE SLIDING BY ACROSS SRN ONTARIO. UPPER RIDGING IS STILL FORECAST TO BUILD INTO THE MIDWEST/OHIO VALLEY LATE IN THE WEEK /LED SEVERAL HUNDRED KM BY A 1024 MB SFC HIGH/...LIKELY BRINGING ANOTHER SUMMER-LIKE PERIOD LATER IN THE EXTENDED. HOWEVER...WITH THE CENTER OF THE RIDGE SITUATED FROM THE MID MISS VALLEY TO LAKE MICHIGAN...AND SLOW RETROGRADE OF THE NORTH ATLC UPPER LOW...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO TEMPS...THE DISTRIBUTION OF CLOUD COVER...THE THE CHC FOR DIURNAL CONVECTION ACROSS THE EASTERN HALF OF PENN LATE IN THE WEEK AND INTO THE UPCOMING WEEKEND. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... CLOUDS WILL CONTINUE TO THICKEN AND LOWER INTO THIS EVENING...IN ADVANCE OF COLD FRONT APPROACHING FROM THE MIDWEST. AN UPPER LEVEL DISTURBANCE LIFTING NWD ALONG THE APPALACHIANS AND COULD TRIGGER ISOLD-SCT SHOWER OR TSTM OVER S/W PA THROUGH THIS EVE. THE MAIN UPPER TROUGH SWINGS ACROSS THE GREAT LAKES LATER TONIGHT INTO TUES...PUSHING THE COLD FRONT THROUGH CENTRAL PA. EXPECT SHRA TO INCREASE IN CVRG/INTENSITY AND SPREAD EASTWARD OVERNIGHT INTO TUES...BEFORE TAPERING OFF FROM WEST TO EAST TUES NGT. MOIST S-SE LOW LEVEL FLOW WILL SUPPORT LOW MVFR TO IFR CIGS...WITH VIS FLUCTUATIONS IN MOD TO OCNLY HVY SHRA/TSRA. ONCE THE FRONT PULLS EAST OF THE REGION...THE REMAINDER OF THE WEEK /WED-SAT/ LOOKS RELATIVELY QUIET AS HIGH PRESSURE BUILDS INTO THE NE UNITED STATES. OUTLOOK... WED-FRI...GENERALLY VFR. ISOLD SHRA/TSRA POSSIBLE EACH AFTN. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO/LAMBERT NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...LAMBERT/GARTNER AVIATION...EVANEGO
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1255 PM CDT MON JUN 11 2012 .DISCUSSION... UPDATED FOR 18Z AVIATION DISCUSSION && .PREV DISCUSSION... /ISSUED 1115 AM CDT MON JUN 11 2012/ UPDATE... UPDATED FOR ANTICIPATED CONVECTION AND SEVERE THREAT. DISCUSSION... A FORWARD PROPAGATING MCS CONTINUES TO PROGRESS EAST-SOUTHEASTWARD ACROSS SOUTHERN MISSOURI. THIS MCS IS PROGRESSING ALONG THE NORTHEASTERN PERIPHERY OF STRONG ELEVATED MIXED LAYER (EML/CAP) OVER MUCH OF ARKANSAS. THIS CAPPING INVERSION WAS ALSO EVIDENT FROM THE 12Z KLZK SOUNDING. THE CAP WEAKENS WITH EASTWARD EXTENT AND THE LATEST STEERING FLOW SUGGESTS THAT THE MCS SHOULD MAKE A TURN MORE TOWARDS THE SOUTH AND INTO THE HEART OF THE MID SOUTH. THE ATMOSPHERE WILL BECOME STRONGLY UNSTABLE IN THE PRE-CONVECTIVE AIRMASS AHEAD OF THE MCS. MLCAPES SHOULD APPROACH OR EVEN EXCEED 4000 J/KG AS TEMPERATURES RISE TO NEAR 90 DEGREES WITH DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S. IN ADDITION...STEEPENING MID LEVEL LAPSE RATES ON EDGE OF THE EML AROUND 7.0 C/KM AND LI/S BETWEEN -8C AND -12C SHOULD BE MORE THAN ENOUGH TO SUSTAIN CONVECTION AND ALLOW FOR THE POTENTIAL OF DAMAGING WINDS AND LARGE HAIL. CONVECTION SHOULD REMAIN ORGANIZED ALONG THE ADVANCING COLD POOL. ADDITIONAL CONVECTION MAY DEVELOP IN ADVANCE OF THE MCS AND WITH STRONG INSTABILITY AND WEAK CAPPING MAY ALSO POSE A SEVERE THREAT. PLAN TO EXPAND THE SLIGHT RISK AREAWIDE AND ADD MENTION OF SEVERE IN THE ZONES. ALSO POPS HAVE BEEN ADJUSTED TO REFLECT THE ANTICIPATED SITUATION. UPDATED ZONES AND GRIDS HAVE BEEN SENT AND THE HWO WILL BE UPDATED SHORTLY. JLH DISCUSSION... /ISSUED 449 AM CDT MON JUN 11 2012/ PRIMARY SHORT TERM FORECAST CONCERN REMAINS RAIN CHANCES. EARLY THIS MORNING... SHORTWAVE RIDGING WAS SPREADING INTO THE MIDSOUTH... IN THE WAKE OF AN UPPER LEVEL SHEAR AXIS THAT BROUGHT SCATTERED SHOWERS TO THE REGION ON SUNDAY. UPSTREAM OF THE SHORTWAVE RIDGE AXIS... A ROBUST LINEAR MCS WAS DROPPING SOUTHEAST THROUGH NW MISSOURI. 850/500MB THICKNESS ANALYSIS SUGGESTS THIS FEATURE MAY BEGIN A MORE SOUTHERLY PROPAGATION. KSGF VAD WIND PROFILER SHOWED 25KTS OF INFLOW...THOUGH THIS INFLOW SHOULD WEAKEN CONSIDERABLY FOLLOWING SUNRISE. AFTER A WEAKENING OF THE MO STORM COMPLEX... NAM MODEL REDEVELOPS STORMS OVER THE OZARK PLATEAU TOWARD MIDDAY. THIS APPEARS A REASONABLE SCENARIO...IN RESPONSE TO SURFACE HEATING... FALLING HEIGHTS AND INCREASING UPPER LEVEL DIFFLUENCE AHEAD OF A LONG WAVE TROF. SURFACED BASED INSTABILITY SHOULD BE IN GOOD SUPPLY ACROSS THE MIDSOUTH THIS AFTERNOON... WITH PARTIAL SUN AND LOWER 70S DEWPOINTS. DESPITE WEAK SHORTWAVE RIDGING...THE HIGH DEWPOINTS SHOULD MAKE CONVECTIVE TEMPS ATTAINABLE THIS AFTERNOON...ENOUGH TO WARRANT CHANCE POPS. MORE ORGANIZED CONVECTIVE ACTIVITY WILL BE POSSIBLE LATE THIS AFTERNOON AND EVENING. THE RIGHT ENTRANCE REGION OF AN UPPER JET CORE WILL INCREASE UPPER LEVEL DIFFLUENCE OVER THE MIDSOUTH... A PATTERN WHICH WILL WILL REMAIN RELATIVELY STATIC OVERNIGHT. THIS SUGGESTS ELEVATED STORMS MAY CONTINUE INTO THE OVERNIGHT... THROUGH MESOSCALE PROPAGATION PROCESSES WILL PLAY A LARGE ROLE ON WHERE STORMS OCCUR. A SURFACE COLD FRONT ARRIVES TUESDAY MORNING...BRINGING DRIER MIDCONTINENTAL AIR TO AREAS NORTH OF I40 BY AFTERNOON. 06Z NAM SUGGESTS THE FRONT MAY HANG UP OVER NORTH MS TUESDAY AFTERNOON... PROVIDING FOCUS FOR ADDITIONAL THUNDERSTORMS. WEDNESDAY WILL SEE DRIER AIR OVER ALL THE MIDSOUTH. TEMPERATURES WILL RECOVER TO NEAR OR SLIGHTLY ABOVE NORMAL VALUES FOR THE LATTER HALF OF THE WEEK. BY FRIDAY... DEWPOINTS RECOVER TO THE 60S. DRY CONDITIONS WILL PREVAIL...THOUGH CANNOT RULE OUT AN ISOLATED AFTERNOON THUNDERSTORM OR TWO UNDER AN UPPER LEVEL SYNOPTIC SCALE RIDGE. PWB && .AVIATION... 18Z TAF SET CONVECTIVE COMPLEX IS SET TO SWEEP THROUGH THE MIDSOUTH THIS AFTERNOON AND EARLY THIS EVENING. THIS IS CORROBORATED WELL BY THE LATEST HRRR RUN. HAVE TIMED TEMPO GROUPS AT ALL SITES. EXPECT A FEW QUIET HOURS AFTER THE PASSAGE OF THE FIRST ROUND OF TSRAS. EXPECT REDEVELOPMENT TO OCCUR OVERNIGHT AS THE FRONT MOVES INTO THE REGION. KEPT A VCTS GOING FOR NOW SINCE IT IS DIFFICULT TO TIME THIS MESOSCALE ACTIVITY BEYOND A FEW HOURS. EXPECT SSW WINDS AT 8-10 KTS THIS AFTERNOON. AS THE COMPLEX MOVES THROUGH WINDS SHOULD SHARPLY SHIFT TO THE NORTH AND GUST. ADDED A WIND GROUP TO KJBR IN ANTICIPATION OF THIS. NOT CONFIDENT ENOUGH AT THE OTHER 3 SITES TO ADD THIS YET. EXPECT WINDS TO BACK AFTER THE COMPLEX MOVES THROUGH AND THEN EVENTUALLY RETURN TO LIGHT SOUTHERLY OVERNIGHT. THE FRONT WILL PASS THROUGH EARLY TUESDAY AND WINDS WILL SHIFT TO THE NORTH AT 8-10 KTS. SJM && .PRELIMINARY POINT TEMPS/POPS... MEM 90 74 87 65 / 60 50 40 10 MKL 88 69 85 59 / 60 50 40 0 JBR 87 67 86 61 / 80 50 10 0 TUP 89 71 86 65 / 50 60 60 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1115 AM CDT MON JUN 11 2012 .UPDATE... UPDATED FOR ANTICIPATED CONVECTION AND SEVERE THREAT. && .DISCUSSION... A FORWARD PROPAGATING MCS CONTINUES TO PROGRESS EAST-SOUTHEASTWARD ACROSS SOUTHERN MISSOURI. THIS MCS IS PROGRESSING ALONG THE NORTHEASTERN PERIPHERY OF STRONG ELEVATED MIXED LAYER (EML/CAP) OVER MUCH OF ARKANSAS. THIS CAPPING INVERSION WAS ALSO EVIDENT FROM THE 12Z KLZK SOUNDING. THE CAP WEAKENS WITH EASTWARD EXTENT AND THE LATEST STEERING FLOW SUGGESTS THAT THE MCS SHOULD MAKE A TURN MORE TOWARDS THE SOUTH AND INTO THE HEART OF THE MID SOUTH. THE ATMOSPERE WILL BECOME STRONGLY UNSTABLE IN THE PRE-CONVECTIVE AIRMASS AHEAD OF THE MCS. MLCAPES SHOULD APPROACH OR EVEN EXCEED 4000 J/KG AS TEMPERATURES RISE TO NEAR 90 DEGREES WITH DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S. IN ADDITION...STEEPENING MID LEVEL LAPSE RATES ON EDGE OF THE EML AROUND 7.0 C/KM AND LI/S BETWEEN -8C AND -12C SHOULD BE MORE THAN ENOUGH TO SUSTAIN CONVECTION AND ALLOW FOR THE POTENTIAL OF DAMAGING WINDS AND LARGE HAIL. CONVECTION SHOULD REMAIN ORGANIZED ALONG THE ADVANCING COLD POOL. ADDITIONAL CONVECTION MAY DEVELOP IN ADVANCE OF THE MCS AND WITH STRONG INSTABILITY AND WEAK CAPPING MAY ALSO POSE A SEVERE THREAT. PLAN TO EXPAND THE SLIGHT RISK AREAWIDE AND ADD MENTION OF SEVERE IN THE ZONES. ALSO POPS HAVE BEEN ADJUSTED TO REFLECT THE ANTICIPATED SITUATION. UPDATED ZONES AND GRIDS HAVE BEEN SENT AND THE HWO WILL BE UPDATED SHORTLY. JLH && .PREV DISCUSSION... /ISSUED 559 AM CDT MON JUN 11 2012/ DISCUSSION... /ISSUED 449 AM CDT MON JUN 11 2012/ PRIMARY SHORT TERM FORECAST CONCERN REMAINS RAIN CHANCES. EARLY THIS MORNING... SHORTWAVE RIDGING WAS SPREADING INTO THE MIDSOUTH... IN THE WAKE OF AN UPPER LEVEL SHEAR AXIS THAT BROUGHT SCATTERED SHOWERS TO THE REGION ON SUNDAY. UPSTREAM OF THE SHORTWAVE RIDGE AXIS... A ROBUST LINEAR MCS WAS DROPPING SOUTHEAST THROUGH NW MISSOURI. 850/500MB THICKNESS ANALYSIS SUGGESTS THIS FEATURE MAY BEGIN A MORE SOUTHERLY PROPAGATION. KSGF VAD WIND PROFILER SHOWED 25KTS OF INFLOW...THOUGH THIS INFLOW SHOULD WEAKEN CONSIDERABLY FOLLOWING SUNRISE. AFTER A WEAKENING OF THE MO STORM COMPLEX... NAM MODEL REDEVELOPS STORMS OVER THE OZARK PLATEAU TOWARD MIDDAY. THIS APPEARS A REASONABLE SCENARIO...IN RESPONSE TO SURFACE HEATING... FALLING HEIGHTS AND INCREASING UPPER LEVEL DIFFLUENCE AHEAD OF A LONG WAVE TROF. SURFACED BASED INSTABILITY SHOULD BE IN GOOD SUPPLY ACROSS THE MIDSOUTH THIS AFTERNOON... WITH PARTIAL SUN AND LOWER 70S DEWPOINTS. DESPITE WEAK SHORTWAVE RIDGING...THE HIGH DEWPOINTS SHOULD MAKE CONVECTIVE TEMPS ATTAINABLE THIS AFTERNOON...ENOUGH TO WARRANT CHANCE POPS. MORE ORGANIZED CONVECTIVE ACTIVITY WILL BE POSSIBLE LATE THIS AFTERNOON AND EVENING. THE RIGHT ENTRANCE REGION OF AN UPPER JET CORE WILL INCREASE UPPER LEVEL DIFFLUENCE OVER THE MIDSOUTH... A PATTERN WHICH WILL WILL REMAIN RELATIVELY STATIC OVERNIGHT. THIS SUGGESTS ELEVATED STORMS MAY CONTINUE INTO THE OVERNIGHT... THROUGH MESOSCALE PROPAGATION PROCESSES WILL PLAY A LARGE ROLE ON WHERE STORMS OCCUR. A SURFACE COLD FRONT ARRIVES TUESDAY MORNING...BRINGING DRIER MIDCONTINENTAL AIR TO AREAS NORTH OF I40 BY AFTERNOON. 06Z NAM SUGGESTS THE FRONT MAY HANG UP OVER NORTH MS TUESDAY AFTERNOON... PROVIDING FOCUS FOR ADDITIONAL THUNDERSTORMS. WEDNESDAY WILL SEE DRIER AIR OVER ALL THE MIDSOUTH. TEMPERATURES WILL RECOVER TO NEAR OR SLIGHTLY ABOVE NORMAL VALUES FOR THE LATTER HALF OF THE WEEK. BY FRIDAY... DEWPOINTS RECOVER TO THE 60S. DRY CONDITIONS WILL PREVAIL...THOUGH CANNOT RULE OUT AN ISOLATED AFTERNOON THUNDERSTORM OR TWO UNDER AN UPPER LEVEL SYNOPTIC SCALE RIDGE. PWB && .AVIATION... 12Z TAF SET COLD FRONT EXPECTED TO MOVE INTO THE CWA OVERNIGHT. HRRR MODEL HAS INITIALIZED THE BEST WITH ONGOING ACTIVITY UP ACROSS MISSOURI THUS HAVE LEANED TOWARD THIS SOLUTION WITH NEW TAF SET. EXPECT POSSIBLY TWO ROUNDS OF SHRA/TSRA ACTIVITY. FIRST...MODEL INDICATING A TSRA COMPLEX DEVELOPING OVER NW ARKANSAS/SW MISSOURI AROUND 17-18Z. MCS WILL PUSH EAST INTO KJBR AFTER 20Z AND POSSIBLY INTO KMEM AFTER 21Z. HAVE ADDED TEMPO GROUPS TO NEW TAF AS A RESULT. NAM ALSO SHOWS THIS FIRST ROUND OF ACTIVITY OCCURRING. THEREAFTER...CONFIDENCE WANES AS HOW FAR EAST AND SOUTH COMPLEX WILL PUSH. A SECOND ROUND OF ACTIVITY COULD OCCUR ALONG FRONT AS IT PUSHES INTO THE AREA. FOR NOW JUST LEFT VCTS WORDING AS CONFIDENCE IS LOW AS EARLIER TSRA COMPLEX (IF IT DOES DEVELOP) COULD STABILIZE THE ATMOSPHERE KILLING ANY ACTIVITY PUSHING INTO THE AREA ALONG THE FRONT. IF HAD TO PICK BEST TIMING AT KMEM FOR SECOND ROUND ACTIVITY TO OCCUR WOULD PICK SOMEWHERE BETWEEN 6Z- 10Z. OTHERWISE...IFR CIGS CURRENTLY OCCURRING SHOULD LIFT TO VFR BY 15-19Z DEPENDING ON LOCATION. SW WINDS BETWEEN 8-12 KTS EXPECTED TODAY...SPEEDS WILL DECREASE AFTER 01Z. KRM && .PRELIMINARY POINT TEMPS/POPS... MEM 90 74 87 65 / 60 50 40 10 MKL 88 69 85 59 / 60 50 40 0 JBR 87 67 86 61 / 80 50 10 0 TUP 89 71 86 65 / 50 60 60 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
559 AM CDT MON JUN 11 2012 .DISCUSSION... /ISSUED 449 AM CDT MON JUN 11 2012/ PRIMARY SHORT TERM FORECAST CONCERN REMAINS RAIN CHANCES. EARLY THIS MORNING... SHORTWAVE RIDGING WAS SPREADING INTO THE MIDSOUTH... IN THE WAKE OF AN UPPER LEVEL SHEAR AXIS THAT BROUGHT SCATTERED SHOWERS TO THE REGION ON SUNDAY. UPSTREAM OF THE SHORTWAVE RIDGE AXIS... A ROBUST LINEAR MCS WAS DROPPING SOUTHEAST THROUGH NW MISSOURI. 850/500MB THICKNESS ANALYSIS SUGGESTS THIS FEATURE MAY BEGIN A MORE SOUTHERLY PROPAGATION. KSGF VAD WIND PROFILER SHOWED 25KTS OF INFLOW...THOUGH THIS INFLOW SHOULD WEAKEN CONSIDERABLY FOLLOWING SUNRISE. AFTER A WEAKENING OF THE MO STORM COMPLEX... NAM MODEL REDEVELOPS STORMS OVER THE OZARK PLATEAU TOWARD MIDDAY. THIS APPEARS A REASONABLE SCENARIO...IN RESPONSE TO SURFACE HEATING... FALLING HEIGHTS AND INCREASING UPPER LEVEL DIFFLUENCE AHEAD OF A LONG WAVE TROF. SURFACED BASED INSTABILITY SHOULD BE IN GOOD SUPPLY ACROSS THE MIDSOUTH THIS AFTERNOON... WITH PARTIAL SUN AND LOWER 70S DEWPOINTS. DESPITE WEAK SHORTWAVE RIDGING...THE HIGH DEWPOINTS SHOULD MAKE CONVECTIVE TEMPS ATTAINABLE THIS AFTERNOON...ENOUGH TO WARRANT CHANCE POPS. MORE ORGANIZED CONVECTIVE ACTIVITY WILL BE POSSIBLE LATE THIS AFTERNOON AND EVENING. THE RIGHT ENTRANCE REGION OF AN UPPER JET CORE WILL INCREASE UPPER LEVEL DIFFLUENCE OVER THE MIDSOUTH... A PATTERN WHICH WILL WILL REMAIN RELATIVELY STATIC OVERNIGHT. THIS SUGGESTS ELEVATED STORMS MAY CONTINUE INTO THE OVERNIGHT... THROUGH MESOSCALE PROPAGATION PROCESSES WILL PLAY A LARGE ROLE ON WHERE STORMS OCCUR. A SURFACE COLD FRONT ARRIVES TUESDAY MORNING...BRINGING DRIER MIDCONTINENTAL AIR TO AREAS NORTH OF I40 BY AFTERNOON. 06Z NAM SUGGESTS THE FRONT MAY HANG UP OVER NORTH MS TUESDAY AFTERNOON... PROVIDING FOCUS FOR ADDITIONAL THUNDERSTORMS. WEDNESDAY WILL SEE DRIER AIR OVER ALL THE MIDSOUTH. TEMPERATURES WILL RECOVER TO NEAR OR SLIGHTLY ABOVE NORMAL VALUES FOR THE LATTER HALF OF THE WEEK. BY FRIDAY... DEWPOINTS RECOVER TO THE 60S. DRY CONDITIONS WILL PREVAIL...THOUGH CANNOT RULE OUT AN ISOLATED AFTERNOON THUNDERSTORM OR TWO UNDER AN UPPER LEVEL SYNOPTIC SCALE RIDGE. PWB && .AVIATION... 12Z TAF SET COLD FRONT EXPECTED TO MOVE INTO THE CWA OVERNIGHT. HRRR MODEL HAS INITIALIZED THE BEST WITH ONGOING ACTIVITY UP ACROSS MISSOURI THUS HAVE LEANED TOWARD THIS SOLUTION WITH NEW TAF SET. EXPECT POSSIBLY TWO ROUNDS OF SHRA/TSRA ACTIVITY. FIRST...MODEL INDICATING A TSRA COMPLEX DEVELOPING OVER NW ARKANSAS/SW MISSOURI AROUND 17-18Z. MCS WILL PUSH EAST INTO KJBR AFTER 20Z AND POSSIBLY INTO KMEM AFTER 21Z. HAVE ADDED TEMPO GROUPS TO NEW TAF AS A RESULT. NAM ALSO SHOWS THIS FIRST ROUND OF ACTIVITY OCCURRING. THEREAFTER...CONFIDENCE WANES AS HOW FAR EAST AND SOUTH COMPLEX WILL PUSH. A SECOND ROUND OF ACTIVITY COULD OCCUR ALONG FRONT AS IT PUSHES INTO THE AREA. FOR NOW JUST LEFT VCTS WORDING AS CONFIDENCE IS LOW AS EARLIER TSRA COMPLEX (IF IT DOES DEVELOP) COULD STABILIZE THE ATMOSPHERE KILLING ANY ACTIVITY PUSHING INTO THE AREA ALONG THE FRONT. IF HAD TO PICK BEST TIMING AT KMEM FOR SECOND ROUND ACTIVITY TO OCCUR WOULD PICK SOMEWHERE BETWEEN 6Z- 10Z. OTHERWISE...IFR CIGS CURRENTLY OCCURRING SHOULD LIFT TO VFR BY 15-19Z DEPENDING ON LOCATION. SW WINDS BETWEEN 8-12 KTS EXPECTED TODAY...SPEEDS WILL DECREASE AFTER 01Z. KRM && && .PRELIMINARY POINT TEMPS/POPS... MEM 90 74 87 65 / 40 50 40 10 MKL 87 69 85 59 / 40 50 40 0 JBR 88 67 86 61 / 40 50 10 0 TUP 88 71 86 65 / 40 60 60 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1254 AM CDT MON JUN 11 2012 .UPDATE... /ISSUED 846 PM CDT SUN JUN 10 2012/ LATEST IR SAT AND RUC13 DATA SHOWS THE UPPER LEVEL LOW MOVING SLOWLY NE TOWARDS MIDDLE TN THIS EVENING FROM NEAR COLUMBUS MS. WITH THE LOSS OF HEATING SHOWERS AND THUNDERSTORMS ARE STARTING TO DECLINE IN COVERAGE ACROSS THE REGION. HAVE LOWERED POPS THROUGH 06Z WITH JUST ISOLATED TO SCTD SHWRS AND TSTORMS IN THE EASTERN PORTIONS OF THE FORECAST AREA OVERNIGHT INTO THE MORNING AT BEST. HIGH CONFIDENCE THAT ONLY A FEW SPOTS WILL EVEN SEE THIS ACTIVITY. TWEAKED TEMPS AND DEWPTS TO MATCH CURRENT READINGS WITH FORECAST LOWS LOOKING GOOD AT THIS POINT. --ABS && .PREV DISCUSSION... /ISSUED 251 PM CDT SUN JUN 10 2012/ INSTABILITY IS IN PLACE...HOWEVER WEAK LOW LEVEL CONVERGENCE HAS BEEN HINDERING CONVECTION...AND A FEW SHOWERS THAT HAVE DEVELOPED HAVE BEEN LIGHT...WITH THE EXCEPTION OF NORTHEAST MISSISSIPPI. NOT CONFIDENT WITH THE 12Z MODELS THAT A QUARTER TO A HALF INCH IN QPF AMOUNTS WILL OVERSPREAD THE MIDSOUTH THROUGH 11/00Z. THEY MAY RECEIVE THAT AMOUNT ACROSS PORTIONS OF NORTHEAST MISSISSIPPI BUT THAT`S ALL. THIS AREA WILL ALSO BE FAVORED FOR AN OCCASIONAL CLAP OF THUNDER...BUT STRONG STORMS SEEMS UNLIKELY. MOST MIDSOUTHERNERS HOWEVER WILL BE LUCKY TO SEE A FEW HUNDREDTHS OF AN INCH. BY SUNSET ANY LINGERING SHOWERS SHOULD BEGIN TO QUICKLY DISSIPATE...WITH DRY CONDITIONS EXPECTED FOR MOST OF THE AREA. ONLY THE FAR EASTERN COUNTIES MAY CONTINUE TO SEE SCATTERED SHOWER ACTIVITY. MOSTLY CLOUDY TO CLOUDY SKIES WILL BE THE RULE AREA WIDE...KEEPING LOW TEMPERATURES A DEGREE OR TWO WARMER THEN LAST NIGHT. MONDAY AND TUESDAY...THE LOW PRESSURE DISTURBANCE CURRENTLY OVER THE MIDSOUTH WILL SLOWLY TRACK EAST THROUGH THE VOLUNTEER STATE AS A MAJOR SHORTWAVE IN THE MAIN JET FLOW CROSSES THE NORTHERN PLAINS AND UPPER MIDWEST. THIS ENERGY WILL SEND A COLD FRONT SOUTHEAST THROUGH THE MID MISSISSIPPI VALLEY MONDAY AFTERNOON. PORTIONS OF THE MIDSOUTH WEST OF THE RIVER ARE ZONED FOR A SLIGHT RISK OF SEVERE WEATHER MONDAY EVENING AND OVERNIGHT AS THE TAIL END OF THE FRONT CROSSES THE OZARKS. LIFTED INDICES NEAR -10C ARE PROGGED FOR LATE TOMORROW AND NEARLY THAT ACROSS NORTH MISSISSIPPI BY MIDDAY TUESDAY AS THE FRONT PUSHES SOUTH. WILL LIKELY REMOVE ANY WORDING FOR A STRONG STORM FOR THIS AFTERNOON WITH THE DISTURBANCE...BUT KEEP MENTION OF SEVERE IN TOMORROW AND TUESDAY. FORECAST HIGHS A BIT TRICKY FOR MONDAY AS LOW LEVEL CLOUD COVER MAY BE ABUNDANT IN THE MORNING HOURS. HAVE LEANED TOWARD THE EURO AND NAM WITH SLIGHTLY COOLER HIGHS. SAME SITUATION ON TUESDAY AS CONVECTION WILL BE ONGOING OVER PORTIONS OF THE AREA. WEDNESDAY THROUGH THURSDAY...MODELS SHOW THE REGION ON THE SOUTH SIDE OF SURFACE HIGH PRESSURE WITH DRIER DEWPOINTS USHERING IN ON NORTHEAST BREEZES. TEMPERATURES WILL BE NEAR AVERAGE FOR MID JUNE...WITH ONLY A SLIGHT CHANCE OF AFTERNOON CONVECTION OVER THE EXTREME SOUTHERN COUNTIES...WHERE DEWPOINTS IN THE MID 60S WILL STILL BE FOUND. NEXT WEEKEND...SOUTHERLY WINDS WILL BRING HIGHER HUMIDITY BACK TO THE MIDSOUTH WITH ISOLATED SUMMERTIME AFTERNOON CONVECTION. HIGH TEMPERATURES WILL WARM SLIGHTLY. JAB && .AVIATION... 06Z TAF CYCLE OVERNIGHT...STILL THINK IFR CONDITIONS WILL DEVELOP AT KMKL AND KTUP WITH LOWERING CEILINGS AND FOG...MVFR CEILINGS DEVELOPING AT KMEM AND KJBR. CONDITIONS THEN GRADUALLY IMPROVING AFTER MID-MORNING MONDAY BECOMING MOSTLY VFR AFTER 18Z. UPPER LEVEL RIDGING IS EXPECTED TO TEMPORARILY SPREADING INTO THE AREA AS THE UPPER LEVEL TROUGH THAT HAS BEEN MOVING THROUGH THE LOWER MS RIVER VALLEY THE LAST COUPLE OF DAYS MOVES TO THE EAST. THIS MAY SUPPRESS CONVECTION EARLY IN THE AFTERNOON...HOWEVER WITH LESS CLOUDS AND STRONG DAYTIME HEATING EXPECTED DECIDED TO ADD VCTS TO THE TAFS AFTER 20Z-21Z. CONTINUED THE MENTION OF VCTS AT KMEM...KMKL..AND KJBR MONDAY EVENING THROUGH 12/06Z AS A COLD FRONT APPROACHES FROM THE NORTHWEST. AT KTUP KEPT VCTS IN UNTIL 12/02Z THEN REMOVED IT WITH THE LOSS OF DAYTIME HEATING. SE-S WINDS 3-7 KTS TONIGHT BECOMING SW 8-12 KTS MONDAY...THEN AFTER 12/00Z GENERALLY SW 5 KTS. JCL/KRM && && .PRELIMINARY POINT TEMPS/POPS... MEM 73 87 66 86 / 50 40 10 10 MKL 69 86 61 85 / 50 40 10 0 JBR 69 86 62 86 / 50 20 10 0 TUP 72 87 64 88 / 50 50 20 10 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
549 PM CDT MON JUN 11 2012 .SHORT TERM...THROUGH WEDNESDAY NIGHT 253 PM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS WITH THE TEMPERATURES THROUGH TUESDAY AND RAIN CHANCES FOR WEDNESDAY NIGHT. SURFACE ANALYSIS THIS AFTERNOON SHOWS A WIND SHIFT/DRY LINE EXTENDING FROM NORTH CENTRAL WISCONSIN THROUGH THE FORECAST AREA INTO NORTHWEST MISSOURI. LOCAL RADAR SHOWS A FEW SHOWERS DEVELOPING ALONG THIS BOUNDARY. THE HRRR HAS BEEN CONSISTENTLY SHOWING THE SHOWERS FORMING OVER THE AREA THIS AFTERNOON. THE 11.15Z RUN CONTINUES THIS TREND SHOWING THEM MOVING TO THE EAST THROUGH THE REMAINDER OF THE AFTERNOON WITH THE BOUNDARY. THE SHOWERS AND BOUNDARY ARE EXPECTED TO BE EAST OF THE FORECAST AREA BY 00Z...SO NO PLANS TO CARRY ANY EVENING RAIN CHANCES. AFTER THAT...IT IS A QUESTION OF HOW MUCH COOL AIR SETTLES IN OVER THE AREA AS HIGH PRESSURE BUILDS IN. BOTH THE 11.12Z NAM AND GFS INDICATE 925 MB TEMPERATURES SHOULD DIP DOWN TO 5-7C TONIGHT BEFORE STARTING TO REBOUND TO AROUND 10C TUESDAY NIGHT. SURFACE TEMPERATURES WILL GENERALLY FALL TO AROUND 50 TONIGHT AS A NORTHWEST BREEZE IS EXPECTED TO CREATE JUST ENOUGH MIXING TO KEEP THEM FROM GOING ANY LOWER. HIGHS TUESDAY WILL BE MUCH COOLER TOPPING OUT IN THE UPPER 60S TO LOWER 70S. THE COOLEST NIGHT WILL BE TUESDAY NIGHT DESPITE THE SLIGHTLY WARMER 925 MB TEMPERATURES. THE SURFACE HIGH WILL BE RIGHT OVER THE AREA ALLOWING THE WINDS TO DECOUPLE AND EXCELLENT RADIATIONAL COOLING TO OCCUR. EXPECTING LOWS TO BE IN THE 40S WITH THE FAVORED COOLER SPOTS DIPPING INTO THE UPPER 30S. AS THE SURFACE HIGH THEN MOVES OFF TO THE EAST...THE CONCERN BECOMES WHETHER THERE WILL BE ANY SHOWERS THAT DEVELOP IN THE RETURN FLOW. THE MODELS SUGGEST THERE WILL BE A SHORT WAVE TROUGH MOVING ACROSS THE DAKOTAS WEDNESDAY NIGHT WITH THE BEST PV ADVECTION IN THE 500-300MB LAYER STAYING NORTHWEST OF THE AREA. THE BEST LOW LEVEL MOISTURE TRANSPORT WILL BE INTO THIS WAVE...BUT THERE WILL ALSO BE A WEAKER BRANCH SPLITTING OFF TO THE NORTHEAST AHEAD OF ANOTHER SHORT WAVE TROUGH. THIS PLACES THE WESTERN SECTIONS OF THE FORECAST UNDER UNDER THE EASTERN CONVERGENT SIDE OF THE MOISTURE TRANSPORT AXIS. THIS IS EXPECTED TO COINCIDE WITH 1-2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE AND WHILE THE FORCING IS NOT THAT STRONG FELT THERE WAS ENOUGH TO JUSTIFY A 20 PERCENT RAIN CHANCES LATE TUESDAY NIGHT OVER THE NORTHWEST SECTIONS OF THE AREA. .LONG TERM...THURSDAY THROUGH MONDAY 253 PM CDT MON JUN 11 2012 CONSIDERABLE UNCERTAINTY IN THE EXTENDED PART OF THE FORECAST. THE UPPER LEVEL RIDGE IS EXPECTED TO BUILD FROM THE SOUTHERN PLAINS INTO SOUTHEAST CANADA. MODELS HAVE BEEN SHOWING RUN TO RUN DIFFERENCES ON HOW FAR WEST THE RIDGE WILL EXTEND AND WHETHER THIS WILL ALLOW ANY SHORT WAVE TROUGHS IN THE SOUTHWEST FLOW TO IMPACT THE AREA. THE 11.12Z ECMWF HAS COME IN WITH AN EVEN FLATTER AND FARTHER EAST RIDGE AXIS WHICH ALLOWS A SYSTEM TO MOVE ACROSS THE UPPER MIDWEST FOR THE WEEKEND. THE GFS AND 11.12Z GEM ARE MORE ROBUST WITH THE RIDGE AXIS WHICH DEFLECTS THIS SYSTEM OFF TO THE NORTHWEST. MODELS ARE KNOWN TO STRUGGLE MIGHTILY WITH SOUTHWEST FLOW SO HAVE OPTED TO LEAVE IN THE SMALL RAIN CHANCES AS CONFIDENCE TO PULL THEM OUT IS JUST NOT THERE. && .AVIATION...TONIGHT AND TUESDAY 549 PM CDT MON JUN 11 2012 VFR CONDITIONS WILL OCCUR THROUGH TOMORROW AS COOLER AIR MOVES INTO THE REGION BEHIND A COLD FRONT. WINDS WILL BE THE TRICKIEST PART OF THE FORECAST WITH SOME FORECAST GUIDANCE...THE 11.21Z RAP MODEL...SHOWING THAT SOME LOW LEVEL MIXING WILL CONTINUE OVERNIGHT AND KEEP SOME GUSTS AROUND. AS SURFACE TEMPERATURES DROP THIS EVENING...THINK THAT WE SHOULD BE ABLE TO DECOUPLE AND END THE GUSTS BETWEEN 1-2Z. THE PRESSURE GRADIENT WILL REMAIN TIGHT OVERNIGHT...SO HAVE KEPT THE SUSTAINED WINDS UP BETWEEN 12-16KTS. OTHERWISE...SKIES WILL CLEAR OUT WITH VFR FAIR WEATHER CU REFORMING TOMORROW MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... 253 PM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
254 PM CDT MON JUN 11 2012 .SHORT TERM...THROUGH WEDNESDAY NIGHT 253 PM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS WITH THE TEMPERATURES THROUGH TUESDAY AND RAIN CHANCES FOR WEDNESDAY NIGHT. SURFACE ANALYSIS THIS AFTERNOON SHOWS A WIND SHIFT/DRY LINE EXTENDING FROM NORTH CENTRAL WISCONSIN THROUGH THE FORECAST AREA INTO NORTHWEST MISSOURI. LOCAL RADAR SHOWS A FEW SHOWERS DEVELOPING ALONG THIS BOUNDARY. THE HRRR HAS BEEN CONSISTENTLY SHOWING THE SHOWERS FORMING OVER THE AREA THIS AFTERNOON. THE 11.15Z RUN CONTINUES THIS TREND SHOWING THEM MOVING TO THE EAST THROUGH THE REMAINDER OF THE AFTERNOON WITH THE BOUNDARY. THE SHOWERS AND BOUNDARY ARE EXPECTED TO BE EAST OF THE FORECAST AREA BY 00Z...SO NO PLANS TO CARRY ANY EVENING RAIN CHANCES. AFTER THAT...IT IS A QUESTION OF HOW MUCH COOL AIR SETTLES IN OVER THE AREA AS HIGH PRESSURE BUILDS IN. BOTH THE 11.12Z NAM AND GFS INDICATE 925 MB TEMPERATURES SHOULD DIP DOWN TO 5-7C TONIGHT BEFORE STARTING TO REBOUND TO AROUND 10C TUESDAY NIGHT. SURFACE TEMPERATURES WILL GENERALLY FALL TO AROUND 50 TONIGHT AS A NORTHWEST BREEZE IS EXPECTED TO CREATE JUST ENOUGH MIXING TO KEEP THEM FROM GOING ANY LOWER. HIGHS TUESDAY WILL BE MUCH COOLER TOPPING OUT IN THE UPPER 60S TO LOWER 70S. THE COOLEST NIGHT WILL BE TUESDAY NIGHT DESPITE THE SLIGHTLY WARMER 925 MB TEMPERATURES. THE SURFACE HIGH WILL BE RIGHT OVER THE AREA ALLOWING THE WINDS TO DECOUPLE AND EXCELLENT RADIATIONAL COOLING TO OCCUR. EXPECTING LOWS TO BE IN THE 40S WITH THE FAVORED COOLER SPOTS DIPPING INTO THE UPPER 30S. AS THE SURFACE HIGH THEN MOVES OFF TO THE EAST...THE CONCERN BECOMES WHETHER THERE WILL BE ANY SHOWERS THAT DEVELOP IN THE RETURN FLOW. THE MODELS SUGGEST THERE WILL BE A SHORT WAVE TROUGH MOVING ACROSS THE DAKOTAS WEDNESDAY NIGHT WITH THE BEST PV ADVECTION IN THE 500-300MB LAYER STAYING NORTHWEST OF THE AREA. THE BEST LOW LEVEL MOISTURE TRANSPORT WILL BE INTO THIS WAVE...BUT THERE WILL ALSO BE A WEAKER BRANCH SPLITTING OFF TO THE NORTHEAST AHEAD OF ANOTHER SHORT WAVE TROUGH. THIS PLACES THE WESTERN SECTIONS OF THE FORECAST UNDER UNDER THE EASTERN CONVERGENT SIDE OF THE MOISTURE TRANSPORT AXIS. THIS IS EXPECTED TO COINCIDE WITH 1-2 UBAR/S OF UP GLIDE ON THE 310K ISENTROPIC SURFACE AND WHILE THE FORCING IS NOT THAT STRONG FELT THERE WAS ENOUGH TO JUSTIFY A 20 PERCENT RAIN CHANCES LATE TUESDAY NIGHT OVER THE NORTHWEST SECTIONS OF THE AREA. .LONG TERM...THURSDAY THROUGH MONDAY 253 PM CDT MON JUN 11 2012 CONSIDERABLE UNCERTAINTY IN THE EXTENDED PART OF THE FORECAST. THE UPPER LEVEL RIDGE IS EXPECTED TO BUILD FROM THE SOUTHERN PLAINS INTO SOUTHEAST CANADA. MODELS HAVE BEEN SHOWING RUN TO RUN DIFFERENCES ON HOW FAR WEST THE RIDGE WILL EXTEND AND WHETHER THIS WILL ALLOW ANY SHORT WAVE TROUGHS IN THE SOUTHWEST FLOW TO IMPACT THE AREA. THE 11.12Z ECMWF HAS COME IN WITH AN EVEN FLATTER AND FARTHER EAST RIDGE AXIS WHICH ALLOWS A SYSTEM TO MOVE ACROSS THE UPPER MIDWEST FOR THE WEEKEND. THE GFS AND 11.12Z GEM ARE MORE ROBUST WITH THE RIDGE AXIS WHICH DEFLECTS THIS SYSTEM OFF TO THE NORTHWEST. MODELS ARE KNOWN TO STRUGGLE MIGHTILY WITH SOUTHWEST FLOW SO HAVE OPTED TO LEAVE IN THE SMALL RAIN CHANCES AS CONFIDENCE TO PULL THEM OUT IS JUST NOT THERE. && .AVIATION...THIS AFTERNOON THROUGH TUESDAY 1220 PM CDT MON JUN 11 2012 QUIET...GOOD VFR PERIOD FOR THIS AFTERNOON THRU TUESDAY AS DRIER CANADIAN HIGH PRESSURE BUILDS INTO THE REGION. WITH COOLER TEMPS ALOFT AND STEEP LOW LEVEL LAPSE RATES...SCT 4K-5K FT DIURNAL CUMULUS WILL DEVELOP FOR THE LATE MORNING AND AFTERNOON HOURS. THE STEEP LAPSE RATES AND DEEPER MIXING WILL ALLOW FOR SOME BRISK/GUSTY WEST TO NORTHWEST WINDS THIS AFTERNOON...DIMINISHING THIS EVENING AS TEMPS COOL AND THE MIXING DEPTH DECREASES. DIURNAL WARMING WITH STEEP LAPSE RATES TO 900-850MB ON TUE WILL RESULT IN NORTHWEST WINDS 10-15KT G20KTS FOR TUE AFTERNOON. WITH LIGHT WINDS...CLEAR SKIES AND CHILLY LOWS EXPECTED TUE NIGHT...WILL HAVE TO WATCH FOR VALLEY FOG FORMATION IN THE 09Z-13Z WED MORNING PERIOD AT SITES LIKE KONA/KLSE/ KPDC/KOVS/KLNR. && .ARX WATCHES/WARNINGS/ADVISORIES... 253 PM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1220 PM CDT MON JUN 11 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT 330 AM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS ON TEMPERATURES THROUGHOUT THE SHORT TERM. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER BRITISH COLUMBIA AND THE EASTERN GREAT LAKES... WITH TROUGHING IN-BETWEEN FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. WITHIN THIS TROUGH...A FAIRLY POTENT SHORTWAVE STRETCHED FROM NORTHERN MN SOUTHWEST INTO SOUTHEAST SOUTH DAKOTA... WHICH IS EVIDENT BY A DEEP DRY SLOT ON WATER VAPOR AND CLEAR SKIES ON IR IMAGERY. 00Z ABR SOUNDING IN THE DRY SLOT WAS VERY DRY WITH A PRECIPITABLE WATER OF 0.51 INCHES. AHEAD OF THE SHORTWAVE...AN AREA OF CONVECTION STRETCHED FROM NORTHERN WI SOUTH INTO FAR NORTHEAST IA/SOUTHWEST WI AND TO THE KANSAS CITY AREA. THE STRONGEST CONVECTION HAS SHIFTED TO THE SOUTHERN END OF THIS LINE...DUE TO BETTER LOW LEVEL CONVERGENCE SEEN IN 925 AND 850MB PROFILER DATA. CONVECTION THAT WAS OVER MN LAST EVENING HAS WEAKENED...DUE TO THE BETTER LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT SHIFTING SOUTH...DECREASING INSTABILITY AHEAD OF THE CONVECTION...AS WELL AS RAP LOW TO MID LEVEL FRONTOGENESIS FIELDS INDICATING WEAKENING THROUGH THE NIGHT. THE ONE CAVEAT TO THIS IS AN MCV RIDING NORTHEAST...ENTERING THE LA CROSSE AREA AS OF 08Z. ON ITS SOUTHEAST SIDE...THE COMBINATION OF DCAPE AROUND 1000 J/KG PER RAP ANALYSIS AND STORMS LINED ORTHOGONAL TO THE 0-3KM SHEAR VECTOR HAS HELPED PRODUCE SOME STRONG TO POSSIBLY DAMAGING WIND GUSTS. AT THE SURFACE...A COLD FRONT WAS PRESENT JUST BEHIND THE CONVECTION... STRETCHING FROM NEAR THUNDER BAY ONTARIO TO LA CROSSE WI. A SECONDARY COLD FRONT WAS PRESENT IN NORTHWEST MN. IN THE WAKE OF THIS FRONT...SATELLITE IMAGERY AND OBSERVATION SHOWED LOW CLOUDS... ISOLATED LIGHT SHOWERS AND MUCH COOLER TEMPERATURES IN THE 50S. TODAY AND TONIGHT...UPPER TROUGHING OVER SOUTH CENTRAL CANADA AND THE NORTHERN PLAINS IS FORECAST TO CONTINUE AN EAST-NORTHEASTWARD MOVEMENT...BEING PROPELLED BY THE CURRENT POTENT SHORTWAVE IN MN AND A SECOND ONE DROPPING DOWN THE BACK SIDE OF THE TROUGH. ALTHOUGH THE BULK OF THE TROUGH LIFTS INTO MANITOBA...NORTHWEST ONTARIO AND LAKE SUPERIOR...SOME OF THE TROUGHING WILL EXTEND DOWN INTO THE FORECAST AREA BY TONIGHT. IN SUMMARY...EXPECT THE TROUGH TO BRING A COOL DOWN FROM WHAT HAS BEEN SEEN LATELY. FIRST ISSUE TO CONTEND WITH IS THE ONGOING SHOWERS AND EMBEDDED THUNDERSTORMS. LATEST HRRR/RAP GUIDANCE AS WELL AS 11.00Z NAM SUGGESTS THE PRECIPITATION MAY BE COMPLETELY EAST OF THE AREA BY 12Z. LOOKS LIKE THERE SHOULD BE A BREAK AS INSTABILITY TRIES TO BUILD AHEAD OF THE MAIN COLD FRONT. HOWEVER...THE MAIN COLD FRONT WILL BE EAST OF THE AREA BEFORE IT CONVECTS...LIKELY BETWEEN 18-21Z. ATTENTION THEN TURNS TO THE SECONDARY COLD FRONT. THIS COMES THROUGH IN THE AFTERNOON...WITH WINDS INCREASING OUT OF THE WEST BEHIND IT. NO PRECIPITATION ANTICIPATED...BUT SOME STRATOCUMULUS AS SEEN BACK IN THE DAKOTAS SHOULD FILTER IN. THESE CLOUDS WILL LIKELY BECOME CELLULAR RESULTING FROM THE STRONG JUNE SUN...THUS DISSIPATING WITH LOSS OF HEATING IN THE EVENING. 850MB TEMPS OF 12-16C AT 18Z PLUS PLENTY OF SUN AND DRY AIR AHEAD OF THE SECONDARY COLD FRONT SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 70S TO MID 80S. TEMPERATURES MAY FALL SLIGHTLY ONCE THE SECONDARY FRONT MOVES IN. BETTER TEMPERATURE FALL EXPECTED TONIGHT AIDED BY NOCTURNAL COOLING AND CONTINUED COLD ADVECTION ON BREEZY NORTHWEST WINDS. BY 12Z TUESDAY...850MB TEMPS ARE PROGGED TO DROP AT LEAST DOWN TO 4-7C...AND PERHAPS SLIGHTLY COOLER AS INDICATED BY THE NAM. WENT WITH A BLEND OF GUIDANCE FOR LOWS...RESULTING IN UPPER 40S TO MID 50S. TUESDAY AND TUESDAY NIGHT...UPPER FLOW IS PROGGED TO GRADUALLY TURN ZONAL DURING THIS PERIOD AS THE UPPER TROUGHING LIFTS AWAY FROM THE AREA. WITHIN THE ZONAL FLOW...A SHORTWAVE IS INDICATED TO REACH CENTRAL SOUTH DAKOTA BY 12Z WEDNESDAY. SOME MID/HIGH CLOUDS ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE COULD GET INTO SOUTHEAST MN AND NORTHEAST IA LATE IN THE NIGHT. OTHERWISE... PLENTY OF DRY AIR NOTED BY PRECIPITABLE WATER VALUES OF 0.5 INCH OR LESS SHOULD KEEP SKIES CLEAR. ALTHOUGH THE DRY AIR AND CLEAR SKIES ARE FAVORABLE FOR WARMING...TEMPERATURES ON TUESDAY MAY STRUGGLE GIVEN 850MB TEMPS PROGGED TO STILL BE AT 4-7C AT 18Z. IN FACT...TAYLOR COUNTY MAY ONLY BE AROUND 2C. THESE ARE 2 STANDARD DEVIATIONS BELOW NORMAL. AS A RESULT...ONLY FORECAST HIGHS IN THE MID 60S TO LOW 70S...20 DEGREES COLDER THAN YESTERDAY. DEWPOINTS ARE LIKELY TO TANK FROM MIXING OF THE DRY AIR. SHOULD BE BREEZY TOO IN THE MORNING ADDING AN EXTRA CHILL BEFORE SURFACE HIGH PRESSURE BUILDS OVERHEAD IN THE EVENING TO CALM WINDS. THIS SETS THE STAGE FOR GOOD RADIATIONAL COOLING TUESDAY NIGHT...ESPECIALLY IN WISCONSIN. WOULD NOT BE SURPRISED TO HAVE SOME UPPER 30S FOR LOWS IN THE TYPICAL COLD SPOTS. WARMER READINGS ARE EXPECTED WEST OF THE MISSISSIPPI RIVER WHERE RETURN FLOW AND CLOUDS COME IN. WEDNESDAY AND WEDNESDAY NIGHT...UPPER LEVEL FLOW LOOKS TO AMPLIFY AGAIN AS TROUGHING DROPS DOWN INTO SOUTHWEST CANADA AND THE PACIFIC NORTHWEST BY 12Z THURSDAY. THIS AMPLIFICATION SHOULD HELP TAKE THE SHORTWAVE THAT WAS COMING INTO SOUTH DAKOTA TUESDAY NIGHT AND LIFT IT WELL NORTHWEST OF THE AREA. BY 00Z THURSDAY...ALL MODELS HAVE IT CROSSING CENTRAL OR NORTHERN MN. GIVEN DRY LOW LEVEL AIRMASS IN PLACE BY THE SURFACE HIGH PRESSURE AREA...AS WELL AS THE TRACK OF THE SHORTWAVE...NOT ANTICIPATING ANY PRECIPITATION TO SPREAD INTO THE FORECAST AREA. HOWEVER...CLOUD COVER IS AN ISSUE. INCREASING 305-310 K ISENTROPIC LIFT EAST OF THE SHORTWAVE SHOULD SPREAD MID AND HIGH CLOUDS ACROSS MUCH OF THE AREA ON WEDNESDAY. THESE CLOUDS MAY LIMITING HEATING SOMEWHAT...DESPITE WARMER 850MB TEMPS IN THE 8-12C RANGE. KEPT HIGHS IN THE LOW TO MID 70S...WHICH ARE ABOUT 5 DEGREES COOLER THAN WHAT THEY COULD BE IF FULL SUN WAS OBSERVED. THE CLOUDS DO LOOK TO CLEAR OUT WEDNESDAY NIGHT AS THE SHORTWAVE HEADS INTO ONTARIO. FOLLOWED A BLEND OF GUIDANCE FOR LOWS GIVEN NO STRONG SIGNAL TO GO COLDER OR WARMER. .LONG TERM...THURSDAY THROUGH SUNDAY NIGHT 330 AM CDT MON JUN 11 2012 11.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES REMAIN IN PRETTY GOOD AGREEMENT ON THE UPPER LEVEL PATTERN...AND IN FACT ARE IN BETTER AGREEMENT NOW COMPARED TO YESTERDAY. CONSENSUS IS THAT TROUGHING WILL HOLD OVER THE NORTHWESTERN U.S. THROUGH MUCH OF THE LONG TERM PERIOD...RESULTING IN STRENGTHENING RIDGING DOWNSTREAM OVER THE WESTERN GREAT LAKES. IN FACT...BY SUNDAY NIGHT WHEN MODELS HAVE THE TROUGH DIGGING MORE INTO THE NORTHERN ROCKIES...THE RIDGE DOWNSTREAM REALLY STRENGTHENS. IT APPEARS THAT MOST OF THE SHORTWAVES EJECTING OUT OF THE TROUGH WILL END UP STAYING MOSTLY TO THE NORTHWEST OF THE AREA. THUS...OVERALL MUCH OF THIS LONG TERM FORECAST LOOKS DRY. HAVE MAINTAINED SOME 20-30 PERCENT CHANCES OVER NORTHWEST PORTIONS OF THE AREA ON SATURDAY...NORTH OF I-90 SATURDAY NIGHT AND ACROSS THE ENTIRE AREA SUNDAY INTO SUNDAY NIGHT. THESE MOSTLY STEM FROM BEING ON THE NOSE OF SOME MOISTURE TRANSPORT AND SHORTWAVES COMING CLOSE TO THE AREA. HOWEVER...IT IS POSSIBLE THESE CHANCES MAY BE ABLE TO BE REMOVED IN LATER FORECASTS WITH MODELS TRENDING DRIER. ONE OTHER PERIOD TO WATCH IS THURSDAY WITH THE 11.00Z ECMWF BEING REALLY AGGRESSIVE IN DEVELOPING PRECIPITATION OVER MN. THIS APPEARS TO BE RELATED TO A SURGE OF WARM...MOIST AIR OCCURRING WITH THE BUILDING RIDGING. GIVEN THAT THE MODEL DOES NOT BRING THE PRECIPITATION INTO THE AREA AND OTHER MODELS SUGGESTING DRIER...HAVE KEPT THURSDAY DRY. WHAT COULD BE MORE SIGNIFICANT FOR THE LONG TERM FORECAST IS TEMPERATURES. WITH THE AREA NOW STRONGLY FORECAST TO BE UNDER RIDGING...AND IN BROAD BREEZY SOUTHERLY FLOW...WE COULD BE DEALING WITH ANOTHER LONG STRETCH OF 80S AND PERHAPS 90S. NEW ECMWF REALLY CAME IN WARM...WITH 850MB TEMPS FRIDAY THROUGH MONDAY HOVERING AROUND 20C OR SO...RESULTING IN HIGHS OF 90-95. HAVE BOOSTED TEMPERATURES UP ABOVE THE CONSENSUS AND THESE MAY STILL BE TOO COOL. && .AVIATION...THIS AFTERNOON THROUGH TUESDAY 1220 PM CDT MON JUN 11 2012 QUIET...GOOD VFR PERIOD FOR THIS AFTERNOON THRU TUESDAY AS DRIER CANADIAN HIGH PRESSURE BUILDS INTO THE REGION. WITH COOLER TEMPS ALOFT AND STEEP LOW LEVEL LAPSE RATES...SCT 4K-5K FT DIURNAL CUMULUS WILL DEVELOP FOR THE LATE MORNING AND AFTERNOON HOURS. THE STEEP LAPSE RATES AND DEEPER MIXING WILL ALLOW FOR SOME BRISK/GUSTY WEST TO NORTHWEST WINDS THIS AFTERNOON...DIMINISHING THIS EVENING AS TEMPS COOL AND THE MIXING DEPTH DECREASES. DIURNAL WARMING WITH STEEP LAPSE RATES TO 900-850MB ON TUE WILL RESULT IN NORTHWEST WINDS 10-15KT G20KTS FOR TUE AFTERNOON. WITH LIGHT WINDS...CLEAR SKIES AND CHILLY LOWS EXPECTED TUE NIGHT...WILL HAVE TO WATCH FOR VALLEY FOG FORMATION IN THE 09Z-13Z WED MORNING PERIOD AT SITES LIKE KONA/KLSE/ KPDC/KOVS/KLNR. && .ARX WATCHES/WARNINGS/ADVISORIES... 330 AM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
645 AM CDT MON JUN 11 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT 330 AM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS ON TEMPERATURES THROUGHOUT THE SHORT TERM. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER BRITISH COLUMBIA AND THE EASTERN GREAT LAKES... WITH TROUGHING IN-BETWEEN FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. WITHIN THIS TROUGH...A FAIRLY POTENT SHORTWAVE STRETCHED FROM NORTHERN MN SOUTHWEST INTO SOUTHEAST SOUTH DAKOTA... WHICH IS EVIDENT BY A DEEP DRY SLOT ON WATER VAPOR AND CLEAR SKIES ON IR IMAGERY. 00Z ABR SOUNDING IN THE DRY SLOT WAS VERY DRY WITH A PRECIPITABLE WATER OF 0.51 INCHES. AHEAD OF THE SHORTWAVE...AN AREA OF CONVECTION STRETCHED FROM NORTHERN WI SOUTH INTO FAR NORTHEAST IA/SOUTHWEST WI AND TO THE KANSAS CITY AREA. THE STRONGEST CONVECTION HAS SHIFTED TO THE SOUTHERN END OF THIS LINE...DUE TO BETTER LOW LEVEL CONVERGENCE SEEN IN 925 AND 850MB PROFILER DATA. CONVECTION THAT WAS OVER MN LAST EVENING HAS WEAKENED...DUE TO THE BETTER LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT SHIFTING SOUTH...DECREASING INSTABILITY AHEAD OF THE CONVECTION...AS WELL AS RAP LOW TO MID LEVEL FRONTOGENESIS FIELDS INDICATING WEAKENING THROUGH THE NIGHT. THE ONE CAVEAT TO THIS IS AN MCV RIDING NORTHEAST...ENTERING THE LA CROSSE AREA AS OF 08Z. ON ITS SOUTHEAST SIDE...THE COMBINATION OF DCAPE AROUND 1000 J/KG PER RAP ANALYSIS AND STORMS LINED ORTHOGONAL TO THE 0-3KM SHEAR VECTOR HAS HELPED PRODUCE SOME STRONG TO POSSIBLY DAMAGING WIND GUSTS. AT THE SURFACE...A COLD FRONT WAS PRESENT JUST BEHIND THE CONVECTION... STRETCHING FROM NEAR THUNDER BAY ONTARIO TO LA CROSSE WI. A SECONDARY COLD FRONT WAS PRESENT IN NORTHWEST MN. IN THE WAKE OF THIS FRONT...SATELLITE IMAGERY AND OBSERVATION SHOWED LOW CLOUDS... ISOLATED LIGHT SHOWERS AND MUCH COOLER TEMPERATURES IN THE 50S. TODAY AND TONIGHT...UPPER TROUGHING OVER SOUTH CENTRAL CANADA AND THE NORTHERN PLAINS IS FORECAST TO CONTINUE AN EAST-NORTHEASTWARD MOVEMENT...BEING PROPELLED BY THE CURRENT POTENT SHORTWAVE IN MN AND A SECOND ONE DROPPING DOWN THE BACK SIDE OF THE TROUGH. ALTHOUGH THE BULK OF THE TROUGH LIFTS INTO MANITOBA...NORTHWEST ONTARIO AND LAKE SUPERIOR...SOME OF THE TROUGHING WILL EXTEND DOWN INTO THE FORECAST AREA BY TONIGHT. IN SUMMARY...EXPECT THE TROUGH TO BRING A COOL DOWN FROM WHAT HAS BEEN SEEN LATELY. FIRST ISSUE TO CONTEND WITH IS THE ONGOING SHOWERS AND EMBEDDED THUNDERSTORMS. LATEST HRRR/RAP GUIDANCE AS WELL AS 11.00Z NAM SUGGESTS THE PRECIPITATION MAY BE COMPLETELY EAST OF THE AREA BY 12Z. LOOKS LIKE THERE SHOULD BE A BREAK AS INSTABILITY TRIES TO BUILD AHEAD OF THE MAIN COLD FRONT. HOWEVER...THE MAIN COLD FRONT WILL BE EAST OF THE AREA BEFORE IT CONVECTS...LIKELY BETWEEN 18-21Z. ATTENTION THEN TURNS TO THE SECONDARY COLD FRONT. THIS COMES THROUGH IN THE AFTERNOON...WITH WINDS INCREASING OUT OF THE WEST BEHIND IT. NO PRECIPITATION ANTICIPATED...BUT SOME STRATOCUMULUS AS SEEN BACK IN THE DAKOTAS SHOULD FILTER IN. THESE CLOUDS WILL LIKELY BECOME CELLULAR RESULTING FROM THE STRONG JUNE SUN...THUS DISSIPATING WITH LOSS OF HEATING IN THE EVENING. 850MB TEMPS OF 12-16C AT 18Z PLUS PLENTY OF SUN AND DRY AIR AHEAD OF THE SECONDARY COLD FRONT SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 70S TO MID 80S. TEMPERATURES MAY FALL SLIGHTLY ONCE THE SECONDARY FRONT MOVES IN. BETTER TEMPERATURE FALL EXPECTED TONIGHT AIDED BY NOCTURNAL COOLING AND CONTINUED COLD ADVECTION ON BREEZY NORTHWEST WINDS. BY 12Z TUESDAY...850MB TEMPS ARE PROGGED TO DROP AT LEAST DOWN TO 4-7C...AND PERHAPS SLIGHTLY COOLER AS INDICATED BY THE NAM. WENT WITH A BLEND OF GUIDANCE FOR LOWS...RESULTING IN UPPER 40S TO MID 50S. TUESDAY AND TUESDAY NIGHT...UPPER FLOW IS PROGGED TO GRADUALLY TURN ZONAL DURING THIS PERIOD AS THE UPPER TROUGHING LIFTS AWAY FROM THE AREA. WITHIN THE ZONAL FLOW...A SHORTWAVE IS INDICATED TO REACH CENTRAL SOUTH DAKOTA BY 12Z WEDNESDAY. SOME MID/HIGH CLOUDS ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE COULD GET INTO SOUTHEAST MN AND NORTHEAST IA LATE IN THE NIGHT. OTHERWISE... PLENTY OF DRY AIR NOTED BY PRECIPITABLE WATER VALUES OF 0.5 INCH OR LESS SHOULD KEEP SKIES CLEAR. ALTHOUGH THE DRY AIR AND CLEAR SKIES ARE FAVORABLE FOR WARMING...TEMPERATURES ON TUESDAY MAY STRUGGLE GIVEN 850MB TEMPS PROGGED TO STILL BE AT 4-7C AT 18Z. IN FACT...TAYLOR COUNTY MAY ONLY BE AROUND 2C. THESE ARE 2 STANDARD DEVIATIONS BELOW NORMAL. AS A RESULT...ONLY FORECAST HIGHS IN THE MID 60S TO LOW 70S...20 DEGREES COLDER THAN YESTERDAY. DEWPOINTS ARE LIKELY TO TANK FROM MIXING OF THE DRY AIR. SHOULD BE BREEZY TOO IN THE MORNING ADDING AN EXTRA CHILL BEFORE SURFACE HIGH PRESSURE BUILDS OVERHEAD IN THE EVENING TO CALM WINDS. THIS SETS THE STAGE FOR GOOD RADIATIONAL COOLING TUESDAY NIGHT...ESPECIALLY IN WISCONSIN. WOULD NOT BE SURPRISED TO HAVE SOME UPPER 30S FOR LOWS IN THE TYPICAL COLD SPOTS. WARMER READINGS ARE EXPECTED WEST OF THE MISSISSIPPI RIVER WHERE RETURN FLOW AND CLOUDS COME IN. WEDNESDAY AND WEDNESDAY NIGHT...UPPER LEVEL FLOW LOOKS TO AMPLIFY AGAIN AS TROUGHING DROPS DOWN INTO SOUTHWEST CANADA AND THE PACIFIC NORTHWEST BY 12Z THURSDAY. THIS AMPLIFICATION SHOULD HELP TAKE THE SHORTWAVE THAT WAS COMING INTO SOUTH DAKOTA TUESDAY NIGHT AND LIFT IT WELL NORTHWEST OF THE AREA. BY 00Z THURSDAY...ALL MODELS HAVE IT CROSSING CENTRAL OR NORTHERN MN. GIVEN DRY LOW LEVEL AIRMASS IN PLACE BY THE SURFACE HIGH PRESSURE AREA...AS WELL AS THE TRACK OF THE SHORTWAVE...NOT ANTICIPATING ANY PRECIPITATION TO SPREAD INTO THE FORECAST AREA. HOWEVER...CLOUD COVER IS AN ISSUE. INCREASING 305-310 K ISENTROPIC LIFT EAST OF THE SHORTWAVE SHOULD SPREAD MID AND HIGH CLOUDS ACROSS MUCH OF THE AREA ON WEDNESDAY. THESE CLOUDS MAY LIMITING HEATING SOMEWHAT...DESPITE WARMER 850MB TEMPS IN THE 8-12C RANGE. KEPT HIGHS IN THE LOW TO MID 70S...WHICH ARE ABOUT 5 DEGREES COOLER THAN WHAT THEY COULD BE IF FULL SUN WAS OBSERVED. THE CLOUDS DO LOOK TO CLEAR OUT WEDNESDAY NIGHT AS THE SHORTWAVE HEADS INTO ONTARIO. FOLLOWED A BLEND OF GUIDANCE FOR LOWS GIVEN NO STRONG SIGNAL TO GO COLDER OR WARMER. .LONG TERM...THURSDAY THROUGH SUNDAY NIGHT 330 AM CDT MON JUN 11 2012 11.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES REMAIN IN PRETTY GOOD AGREEMENT ON THE UPPER LEVEL PATTERN...AND IN FACT ARE IN BETTER AGREEMENT NOW COMPARED TO YESTERDAY. CONSENSUS IS THAT TROUGHING WILL HOLD OVER THE NORTHWESTERN U.S. THROUGH MUCH OF THE LONG TERM PERIOD...RESULTING IN STRENGTHENING RIDGING DOWNSTREAM OVER THE WESTERN GREAT LAKES. IN FACT...BY SUNDAY NIGHT WHEN MODELS HAVE THE TROUGH DIGGING MORE INTO THE NORTHERN ROCKIES...THE RIDGE DOWNSTREAM REALLY STRENGTHENS. IT APPEARS THAT MOST OF THE SHORTWAVES EJECTING OUT OF THE TROUGH WILL END UP STAYING MOSTLY TO THE NORTHWEST OF THE AREA. THUS...OVERALL MUCH OF THIS LONG TERM FORECAST LOOKS DRY. HAVE MAINTAINED SOME 20-30 PERCENT CHANCES OVER NORTHWEST PORTIONS OF THE AREA ON SATURDAY...NORTH OF I-90 SATURDAY NIGHT AND ACROSS THE ENTIRE AREA SUNDAY INTO SUNDAY NIGHT. THESE MOSTLY STEM FROM BEING ON THE NOSE OF SOME MOISTURE TRANSPORT AND SHORTWAVES COMING CLOSE TO THE AREA. HOWEVER...IT IS POSSIBLE THESE CHANCES MAY BE ABLE TO BE REMOVED IN LATER FORECASTS WITH MODELS TRENDING DRIER. ONE OTHER PERIOD TO WATCH IS THURSDAY WITH THE 11.00Z ECMWF BEING REALLY AGGRESSIVE IN DEVELOPING PRECIPITATION OVER MN. THIS APPEARS TO BE RELATED TO A SURGE OF WARM...MOIST AIR OCCURRING WITH THE BUILDING RIDGING. GIVEN THAT THE MODEL DOES NOT BRING THE PRECIPITATION INTO THE AREA AND OTHER MODELS SUGGESTING DRIER...HAVE KEPT THURSDAY DRY. WHAT COULD BE MORE SIGNIFICANT FOR THE LONG TERM FORECAST IS TEMPERATURES. WITH THE AREA NOW STRONGLY FORECAST TO BE UNDER RIDGING...AND IN BROAD BREEZY SOUTHERLY FLOW...WE COULD BE DEALING WITH ANOTHER LONG STRETCH OF 80S AND PERHAPS 90S. NEW ECMWF REALLY CAME IN WARM...WITH 850MB TEMPS FRIDAY THROUGH MONDAY HOVERING AROUND 20C OR SO...RESULTING IN HIGHS OF 90-95. HAVE BOOSTED TEMPERATURES UP ABOVE THE CONSENSUS AND THESE MAY STILL BE TOO COOL. && .AVIATION...TODAY AND TONIGHT 645 AM CDT MON JUN 11 2012 CONCERNS DEAL WITH A FEW LOW CLOUDS THIS MORNING...THEN WINDS THROUGH THE REST OF TODAY. CURRENTLY WATCHING A COLD FRONT MOVE EAST OF THE MISSISSIPPI INTO CENTRAL WISCONSIN...BRINGING LINE OF SHRA/TS WITH IT. LOOSE GRADIENT IMMEDIATELY BEHIND THE FRONT PRODUCING LIGHT WINDS AT KRST/KLSE TAF SITES EARLY THIS MORNING. LIGHTER WINDS AND RESIDUAL LOWER BOUNDARY LAYER MOISTURE FROM OVERNIGHT RAINFALL WAS ALLOWING POCKETS OF STRATUS TO DEVELOP. SO FAR...STRATUS WITH BASES AOB 600 FEET SCATTERED IN NATURE AND IS EXPECTED TO DISSIPATE 13-14Z AS WINDS START TO VEER TO THE WEST AND DRYING OF THE BOUNDARY LAYER TAKES PLACE. LOOK FOR THE PRESSURE GRADIENT AND RESULTANT WEST WINDS TO INCREASE BY 16Z WITH GUSTS IN THE 20-30KT RANGE PREVALENT BY AFTERNOON. SCATTERED CUMULUS WITH BASES 4-5KFT EXPECTED TO DEVELOP BY MIDDAY AS AN UPPER LEVEL TROUGH SWINGS ACROSS THE DAKOTAS INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. LOOK FOR THE WINDS TO SUBSIDE AND CUMULUS TO DISSIPATE TOWARD SUNSET. MOSTLY CLEAR/VFR CONDITIONS EXPECTED OVERNIGHT AS HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS. && .ARX WATCHES/WARNINGS/ADVISORIES... 330 AM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 AM CDT MON JUN 11 2012 .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT 330 AM CDT MON JUN 11 2012 MAIN FORECAST CONCERN IS ON TEMPERATURES THROUGHOUT THE SHORT TERM. CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED RIDGING OVER BRITISH COLUMBIA AND THE EASTERN GREAT LAKES... WITH TROUGHING IN-BETWEEN FROM SOUTH CENTRAL CANADA INTO THE NORTHERN PLAINS. WITHIN THIS TROUGH...A FAIRLY POTENT SHORTWAVE STRETCHED FROM NORTHERN MN SOUTHWEST INTO SOUTHEAST SOUTH DAKOTA... WHICH IS EVIDENT BY A DEEP DRY SLOT ON WATER VAPOR AND CLEAR SKIES ON IR IMAGERY. 00Z ABR SOUNDING IN THE DRY SLOT WAS VERY DRY WITH A PRECIPITABLE WATER OF 0.51 INCHES. AHEAD OF THE SHORTWAVE...AN AREA OF CONVECTION STRETCHED FROM NORTHERN WI SOUTH INTO FAR NORTHEAST IA/SOUTHWEST WI AND TO THE KANSAS CITY AREA. THE STRONGEST CONVECTION HAS SHIFTED TO THE SOUTHERN END OF THIS LINE...DUE TO BETTER LOW LEVEL CONVERGENCE SEEN IN 925 AND 850MB PROFILER DATA. CONVECTION THAT WAS OVER MN LAST EVENING HAS WEAKENED...DUE TO THE BETTER LOW LEVEL CONVERGENCE AND MOISTURE TRANSPORT SHIFTING SOUTH...DECREASING INSTABILITY AHEAD OF THE CONVECTION...AS WELL AS RAP LOW TO MID LEVEL FRONTOGENESIS FIELDS INDICATING WEAKENING THROUGH THE NIGHT. THE ONE CAVEAT TO THIS IS AN MCV RIDING NORTHEAST...ENTERING THE LA CROSSE AREA AS OF 08Z. ON ITS SOUTHEAST SIDE...THE COMBINATION OF DCAPE AROUND 1000 J/KG PER RAP ANALYSIS AND STORMS LINED ORTHOGONAL TO THE 0-3KM SHEAR VECTOR HAS HELPED PRODUCE SOME STRONG TO POSSIBLY DAMAGING WIND GUSTS. AT THE SURFACE...A COLD FRONT WAS PRESENT JUST BEHIND THE CONVECTION... STRETCHING FROM NEAR THUNDER BAY ONTARIO TO LA CROSSE WI. A SECONDARY COLD FRONT WAS PRESENT IN NORTHWEST MN. IN THE WAKE OF THIS FRONT...SATELLITE IMAGERY AND OBSERVATION SHOWED LOW CLOUDS... ISOLATED LIGHT SHOWERS AND MUCH COOLER TEMPERATURES IN THE 50S. TODAY AND TONIGHT...UPPER TROUGHING OVER SOUTH CENTRAL CANADA AND THE NORTHERN PLAINS IS FORECAST TO CONTINUE AN EAST-NORTHEASTWARD MOVEMENT...BEING PROPELLED BY THE CURRENT POTENT SHORTWAVE IN MN AND A SECOND ONE DROPPING DOWN THE BACK SIDE OF THE TROUGH. ALTHOUGH THE BULK OF THE TROUGH LIFTS INTO MANITOBA...NORTHWEST ONTARIO AND LAKE SUPERIOR...SOME OF THE TROUGHING WILL EXTEND DOWN INTO THE FORECAST AREA BY TONIGHT. IN SUMMARY...EXPECT THE TROUGH TO BRING A COOL DOWN FROM WHAT HAS BEEN SEEN LATELY. FIRST ISSUE TO CONTEND WITH IS THE ONGOING SHOWERS AND EMBEDDED THUNDERSTORMS. LATEST HRRR/RAP GUIDANCE AS WELL AS 11.00Z NAM SUGGESTS THE PRECIPITATION MAY BE COMPLETELY EAST OF THE AREA BY 12Z. LOOKS LIKE THERE SHOULD BE A BREAK AS INSTABILITY TRIES TO BUILD AHEAD OF THE MAIN COLD FRONT. HOWEVER...THE MAIN COLD FRONT WILL BE EAST OF THE AREA BEFORE IT CONVECTS...LIKELY BETWEEN 18-21Z. ATTENTION THEN TURNS TO THE SECONDARY COLD FRONT. THIS COMES THROUGH IN THE AFTERNOON...WITH WINDS INCREASING OUT OF THE WEST BEHIND IT. NO PRECIPITATION ANTICIPATED...BUT SOME STRATOCUMULUS AS SEEN BACK IN THE DAKOTAS SHOULD FILTER IN. THESE CLOUDS WILL LIKELY BECOME CELLULAR RESULTING FROM THE STRONG JUNE SUN...THUS DISSIPATING WITH LOSS OF HEATING IN THE EVENING. 850MB TEMPS OF 12-16C AT 18Z PLUS PLENTY OF SUN AND DRY AIR AHEAD OF THE SECONDARY COLD FRONT SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE UPPER 70S TO MID 80S. TEMPERATURES MAY FALL SLIGHTLY ONCE THE SECONDARY FRONT MOVES IN. BETTER TEMPERATURE FALL EXPECTED TONIGHT AIDED BY NOCTURNAL COOLING AND CONTINUED COLD ADVECTION ON BREEZY NORTHWEST WINDS. BY 12Z TUESDAY...850MB TEMPS ARE PROGGED TO DROP AT LEAST DOWN TO 4-7C...AND PERHAPS SLIGHTLY COOLER AS INDICATED BY THE NAM. WENT WITH A BLEND OF GUIDANCE FOR LOWS...RESULTING IN UPPER 40S TO MID 50S. TUESDAY AND TUESDAY NIGHT...UPPER FLOW IS PROGGED TO GRADUALLY TURN ZONAL DURING THIS PERIOD AS THE UPPER TROUGHING LIFTS AWAY FROM THE AREA. WITHIN THE ZONAL FLOW...A SHORTWAVE IS INDICATED TO REACH CENTRAL SOUTH DAKOTA BY 12Z WEDNESDAY. SOME MID/HIGH CLOUDS ASSOCIATED WITH ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE COULD GET INTO SOUTHEAST MN AND NORTHEAST IA LATE IN THE NIGHT. OTHERWISE... PLENTY OF DRY AIR NOTED BY PRECIPITABLE WATER VALUES OF 0.5 INCH OR LESS SHOULD KEEP SKIES CLEAR. ALTHOUGH THE DRY AIR AND CLEAR SKIES ARE FAVORABLE FOR WARMING...TEMPERATURES ON TUESDAY MAY STRUGGLE GIVEN 850MB TEMPS PROGGED TO STILL BE AT 4-7C AT 18Z. IN FACT...TAYLOR COUNTY MAY ONLY BE AROUND 2C. THESE ARE 2 STANDARD DEVIATIONS BELOW NORMAL. AS A RESULT...ONLY FORECAST HIGHS IN THE MID 60S TO LOW 70S...20 DEGREES COLDER THAN YESTERDAY. DEWPOINTS ARE LIKELY TO TANK FROM MIXING OF THE DRY AIR. SHOULD BE BREEZY TOO IN THE MORNING ADDING AN EXTRA CHILL BEFORE SURFACE HIGH PRESSURE BUILDS OVERHEAD IN THE EVENING TO CALM WINDS. THIS SETS THE STAGE FOR GOOD RADIATIONAL COOLING TUESDAY NIGHT...ESPECIALLY IN WISCONSIN. WOULD NOT BE SURPRISED TO HAVE SOME UPPER 30S FOR LOWS IN THE TYPICAL COLD SPOTS. WARMER READINGS ARE EXPECTED WEST OF THE MISSISSIPPI RIVER WHERE RETURN FLOW AND CLOUDS COME IN. WEDNESDAY AND WEDNESDAY NIGHT...UPPER LEVEL FLOW LOOKS TO AMPLIFY AGAIN AS TROUGHING DROPS DOWN INTO SOUTHWEST CANADA AND THE PACIFIC NORTHWEST BY 12Z THURSDAY. THIS AMPLIFICATION SHOULD HELP TAKE THE SHORTWAVE THAT WAS COMING INTO SOUTH DAKOTA TUESDAY NIGHT AND LIFT IT WELL NORTHWEST OF THE AREA. BY 00Z THURSDAY...ALL MODELS HAVE IT CROSSING CENTRAL OR NORTHERN MN. GIVEN DRY LOW LEVEL AIRMASS IN PLACE BY THE SURFACE HIGH PRESSURE AREA...AS WELL AS THE TRACK OF THE SHORTWAVE...NOT ANTICIPATING ANY PRECIPITATION TO SPREAD INTO THE FORECAST AREA. HOWEVER...CLOUD COVER IS AN ISSUE. INCREASING 305-310 K ISENTROPIC LIFT EAST OF THE SHORTWAVE SHOULD SPREAD MID AND HIGH CLOUDS ACROSS MUCH OF THE AREA ON WEDNESDAY. THESE CLOUDS MAY LIMITING HEATING SOMEWHAT...DESPITE WARMER 850MB TEMPS IN THE 8-12C RANGE. KEPT HIGHS IN THE LOW TO MID 70S...WHICH ARE ABOUT 5 DEGREES COOLER THAN WHAT THEY COULD BE IF FULL SUN WAS OBSERVED. THE CLOUDS DO LOOK TO CLEAR OUT WEDNESDAY NIGHT AS THE SHORTWAVE HEADS INTO ONTARIO. FOLLOWED A BLEND OF GUIDANCE FOR LOWS GIVEN NO STRONG SIGNAL TO GO COLDER OR WARMER. .LONG TERM...THURSDAY THROUGH SUNDAY NIGHT 330 AM CDT MON JUN 11 2012 11.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES REMAIN IN PRETTY GOOD AGREEMENT ON THE UPPER LEVEL PATTERN...AND IN FACT ARE IN BETTER AGREEMENT NOW COMPARED TO YESTERDAY. CONSENSUS IS THAT TROUGHING WILL HOLD OVER THE NORTHWESTERN U.S. THROUGH MUCH OF THE LONG TERM PERIOD...RESULTING IN STRENGTHENING RIDGING DOWNSTREAM OVER THE WESTERN GREAT LAKES. IN FACT...BY SUNDAY NIGHT WHEN MODELS HAVE THE TROUGH DIGGING MORE INTO THE NORTHERN ROCKIES...THE RIDGE DOWNSTREAM REALLY STRENGTHENS. IT APPEARS THAT MOST OF THE SHORTWAVES EJECTING OUT OF THE TROUGH WILL END UP STAYING MOSTLY TO THE NORTHWEST OF THE AREA. THUS...OVERALL MUCH OF THIS LONG TERM FORECAST LOOKS DRY. HAVE MAINTAINED SOME 20-30 PERCENT CHANCES OVER NORTHWEST PORTIONS OF THE AREA ON SATURDAY...NORTH OF I-90 SATURDAY NIGHT AND ACROSS THE ENTIRE AREA SUNDAY INTO SUNDAY NIGHT. THESE MOSTLY STEM FROM BEING ON THE NOSE OF SOME MOISTURE TRANSPORT AND SHORTWAVES COMING CLOSE TO THE AREA. HOWEVER...IT IS POSSIBLE THESE CHANCES MAY BE ABLE TO BE REMOVED IN LATER FORECASTS WITH MODELS TRENDING DRIER. ONE OTHER PERIOD TO WATCH IS THURSDAY WITH THE 11.00Z ECMWF BEING REALLY AGGRESSIVE IN DEVELOPING PRECIPITATION OVER MN. THIS APPEARS TO BE RELATED TO A SURGE OF WARM...MOIST AIR OCCURRING WITH THE BUILDING RIDGING. GIVEN THAT THE MODEL DOES NOT BRING THE PRECIPITATION INTO THE AREA AND OTHER MODELS SUGGESTING DRIER...HAVE KEPT THURSDAY DRY. WHAT COULD BE MORE SIGNIFICANT FOR THE LONG TERM FORECAST IS TEMPERATURES. WITH THE AREA NOW STRONGLY FORECAST TO BE UNDER RIDGING...AND IN BROAD BREEZY SOUTHERLY FLOW...WE COULD BE DEALING WITH ANOTHER LONG STRETCH OF 80S AND PERHAPS 90S. NEW ECMWF REALLY CAME IN WARM...WITH 850MB TEMPS FRIDAY THROUGH MONDAY HOVERING AROUND 20C OR SO...RESULTING IN HIGHS OF 90-95. HAVE BOOSTED TEMPERATURES UP ABOVE THE CONSENSUS AND THESE MAY STILL BE TOO COOL. && .AVIATION...THROUGH 06Z TUESDAY 1110 PM CDT SUN JUN 10 2012 SHOWERS AND THUNDERSTORMS WILL MOVE EAST ALONG AND JUST BEHIND A COLD FRONT THAT CURRENTLY EXTENDS FROM THE TWIN CITIES DOWN TO MASON CITY. IT LOOKS LIKE IT WILL BE ABOUT A 3-4 HOUR PERIOD OF CONVECTION WITH SOME INTERMITTENT THUNDERSTORMS POSSIBLE. CONDITIONS WILL MAINLY BE VFR THOUGH CEILINGS MAY DROP DOWN TO BETWEEN 2-3KFT FOR A PERIOD AS THE SHOWERS AND STORMS MOVE THROUGH OVERNIGHT. WINDS WILL GO LIGHT AFTER THE FRONT AND CONVECTION PASSES THROUGH...BUT CLOUD COVER WILL LIKELY PERSIST THROUGH DAYBREAK. THUS...AM NOT EXPECTING ANY FOG TO FORM AT RST OR LSE THIS MORNING. WINDS WILL INCREASE INTO THE 20-25KT RANGE THIS AFTERNOON AS A SECONDARY COLD FRONT MOVES THROUGH THE REGION. && .ARX WATCHES/WARNINGS/ADVISORIES... 330 AM CDT MON JUN 11 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 AM EDT WED JUN 13 2012 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 325 PM EDT TUE JUN 12 2012 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PROGRESSIVE UPR TROF EXTENDING FM HUDSON BAY INTO THE GRT LKS MOVING E IN ADVANCE OF UPR RDG OVER WRN CANADA. SHRTWV EMBEDDED WITHIN THIS TROF BROUGHT LOTS OF CLDS AND SOME -SHRA TO MAINLY THE NRN TIER INTO EARLY AFTN... BUT TREND THIS AFTN HAS BEEN FOR MORE SUNSHINE AS DNVA/ LARGER SCALE QVECTOR DVGC/MORE ACYC FLOW AND DRIER AIR SHOWN ON THE 12Z INL RAOB IS FOLLOWING IN THE WAKE OF THAT DISTURBANCE IN ADVANCE OF SFC HI PRES CENTERED OVER SE SDAKOTA. SKIES ARE MOCLR FM THE HI CENTER STRETCHING TOWARD LK WINNIPEG...WHERE THE 12Z RAOB AT THE PAS IN MANITOBA SHOWS A PWAT OF 0.28 INCH. SFC DEWPTS THIS AFTN HAVE MIXED OUT INTO THE LO-MID 30S IN THIS UPSTREAM AIRMASS. MORE CLDS ARE PRESENT A BIT FARTHER W IN THE NRN PLAINS IN THE RETURN SW FLOW ARND THE SFC HI AND IN ADVANCE OF SHRTWV TRACKING E ACRS WYOMING/MONTANA. 12Z BIS RAOB SHOWS MORE MSTR/PWAT OF 0.70 INCH NEAR THE WAD CLD BAND. MAIN FCST CONCERNS IN THE SHORT TERM REVOLVE ARND CLRG TRENDS THIS AFTN AND THEN TEMPS/POTENTIAL FOR FROST TNGT. TNGT...SFC HI PRES IS FCST TO MOVE E AND TO OVER NRN LWR MI BY 12Z WED. EXPECT ANY LINGERING CLDS TO DSPT LATE THIS AFTN/EARLY THIS EVNG WITH THE ARRIVAL OF MORE ACYC FLOW AND WARMER/DRIER AIR AT H925. STRONGER WSW FLOW ARND SFC HI IS FCST TO DVLP OVER THE NW HALF OF THE CWA AFT 06Z...WITH PWAT RISING AS THIS FLOW TAPS MORE MSTR SHOWN ON THE 12Z BIS RAOB. MOST SUSTAINED CONDITIONS FOR RADIATIONAL COOLING LOOK TO BE OVER THE SCNTRL AND E...WHERE THE GRADIENT FLOW WL REMAIN WEAKER/PWAT LOWER AND UNDER 0.5 INCH THRU 12Z WED. OPTED TO EXTEND GOING FROST ADVY NEAR THE WI BORDER TO INCLUDE MOST OF THE CWA FROM BARAGA TO THE E...WITH MIN TEMPS CLOSER TO THE LOWER END OF GUIDANCE IN THESE AREAS PER OBSVD MIXING OF DEWPTS UPSTREAM. WED...AS SFC HI PRES DRIFTS SLOWLY E ACRS LK HURON...STRONGER SW FLOW WL DVLP OVER THE ENTIRE CWA. WITH APRCH OF DISTURBANCE NOW MOVING THRU THE NRN PLAINS AND SOME MSTR RETURN...EXPECT AT LEAST SOME CLDS TO INVADE MAINLY THE WRN ZNS IN THE AFTN. ALTHOUGH THE GFS GENERATES SOME PCPN OVER THE FAR W LATE IN THE DAY...PREFER TO FOLLOW THE DRY 12Z NAM/CNDN/LOCAL WRF-ARW DUE TO VERY DRY NATURE OF LLVL AIRMASS. MIXING TO H8 ON NAM FCST SDNGS YIELDS HI TEMPS REBOUNDING TO 70 TO 75 AWAY FM LK MODERATION. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 PM EDT TUE JUN 12 2012 THE WEAK HIGH PRESSURE RIDGE IN PLACE FOR WEDNESDAY WILL SLIDE EASTWARD AS A TROUGH OVER THE CANADIAN PRAIRIE DIGS DOWN INTO THE NORTHERN PLAINS. MODELS AGREE THAT A SHORTWAVE WILL BE APPROACHING WESTERN UPPER MICHIGAN BY 00Z THURSDAY...THOUGH THERE SEEMS TO BE DIFFERENCES WITH HOW STRONG IT WILL BE. THE GEM/ECMWF SEEM TO AGREE ON A WEAKER SOLUTION...WHILE THE GFS DEVELOPS A SMALL TROUGH. THE GFS ALSO AMPLIFIES THE EXITING RIDGE MUCH MORE THAN THE OTHER MODELS. WILL STICK WITH A BLEND MORE SIMILAR TO THE GEM/ECMWF FOR NOW GIVEN THEIR AGREEMENT...THOUGH CONFIDENCE IS NOT VERY HIGH. THIS KEEPS MOST OF THE PRECIPITATION THAT WILL OCCUR WITH THIS SHORTWAVE OVER WESTERN LAKE SUPERIOR AND THE WEST HALF OF THE CWA. WILL KEEP LOW CHANCE POPS OVER THESE AREAS TO ACCOUNT FOR UNCERTAINTY DURING THE DAY ON THURSDAY. MODEL SOUNDINGS SUGGEST MIXING TO AROUND 850MB...WHICH PUTS HIGHS IN THE 70S AND PERHAPS LOW 80S. DESPITE INCOMING CLOUD COVER WITH THE SHORTWAVE...EXPECT THE WARMEST TEMPERATURES TO BE OUT WEST WITH THE HIGHEST 850MB TEMPS OF AROUND 13C. WITH SKIES MOSTLY SUNNY OUT EAST...EXPECT MIXING TO BRING RELATIVE HUMIDITY DOWN INTO THE 30 PERCENT RANGE. WITH THE STRONGER PRESSURE GRADIENT ASSOCIATED WITH THE LOW PRESSURE SYSTEM...EXPECT GUSTY SOUTHERLY TO SOUTHEASTERLY WINDS ACROSS MUCH OF THE AREA...MAINLY NORTH CENTRAL AND OVER LAKE SUPERIOR. HIGHEST GUSTS ARE EXPECTED TO BE AROUND 25 KNOTS. FRIDAY THE TROUGH WILL SWING JUST NORTH OF LAKE SUPERIOR...REACHING HUDSON BAY BY 00Z SATURDAY. MODELS SEEM TO BE IN FAIRLY GOOD AGREEMENT ON THE AMOUNT OF QPF ASSOCIATED WITH THE PASSING FRONT ACROSS WEST AND CENTRAL UPPER MICHIGAN...WITH AROUND 0.25-0.50 INCH IMPACTING THE AREA. THE NAM BRINGS THE FRONT ALL THE WAY THROUGH THE CWA...BRINGING 0.25 INCH TO THE EASTERN AREAS. THE ECMWF/GEM/GFS TAKE THE BEST UPPER LEVEL FORCING NORTHWARD /PER 850-500MB QVECTOR CONVERGENCE/ AND THEREFORE KEEP MUCH OF THE EASTERN CWA DRY. THERE ARE ALSO DIFFERENCES IN TIMING OF PRECIPITATION...SO HAVE LOWERED CONFIDENCE IN PUTTING SPECIFICS INTO THE FORECAST. KEPT THE BEST CHANCES OVER LAKE SUPERIOR AND ACROSS THE WEST AND CENTRAL. MU/ML CAPE VALUES THURSDAY NIGHT INTO FRIDAY AFTERNOON RANGE FROM AROUND 200-1000 J/KG...SO KEPT THUNDER CHANCES IN. WITH PRESSURE GRADIENT REMAINING TIGHT...WINDS WILL CONTINUE TO GUST INTO THE 20-25 KNOT RANGE THROUGH FRIDAY EVENING. FOR THE EXTENDED /THE WEEKEND INTO TUESDAY/... FOR THE MOST PART...IT SEEMS THROUGH THE WEEKEND A RIDGE WILL CENTER ITSELF OVER LOWER MICHIGAN...AND SHORTWAVES WILL RIDE AROUND THE IT BRINGING CHANCES OF PRECIPITATION. FOR THE FIRST PART OF THE WORK WEEK...A STRONGER LOW PRESSURE TROUGH WILL SWING INTO THE NORTHERN PLAINS AND BRING ADDITIONAL PRECIPITATION/THUNDERSTORMS TO MUCH OF THE CWA. HOWEVER...MODELS DIFFER ON TIMING AND PLACEMENT OF FEATURES. THE GFS/GEM BRING A STRONGER RIDGE UP FROM THE PLAINS...KEEPING MUCH OF THE PRECIPITATION ASSOCIATED WITH A SECOND TROUGH/SHORTWAVE CONFINED TO THE WESTERN CWA OR NOT IN THE UPPER PENINSULA AT ALL. THE GFS EVENTUALLY DEVELOPS THE TROUGH INTO A CLOSED LOW...AND THEN MOVES THE PRECIPITATION THROUGH ON MONDAY. THE ECMWF KEEPS THE RIDGE FURTHER SOUTH AND EAST...AND BRINGS A MUCH MORE POTENT SHORTWAVE INTO UPPER MICHIGAN SATURDAY MORNING INTO MONDAY. WITH SUCH A VARIANCE IN SOLUTIONS...DO NOT FEEL CONFIDENT BUMPING UP ANY POPS. WILL KEEP THE MENTION OF THUNDER AS MODELS SEEM TO BRING IN A DECENT AMOUNT OF INSTABILITY THROUGH THE WEEKEND. AS FOR HIGH TEMPERATURES...850MB TEMPS LOOK TO BE IN THE 16-18C RANGE...SO WILL KEEP FORECASTED HIGHS IN THE UPPER 70S TO THE MID 80S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 132 AM EDT WED JUN 13 2012 HIGH PRESSURE TO INFLUENCE THE WEATHER THROUGH THE FORECAST PERIOD WITH VFR CONDITIONS PREVAILING. WINDS TO STAY LIGHT OVERNIGHT UNTIL PICKING UP FROM THE SW AFTER SUNRISE AS SFC HIGH SHIFTS EAST. SOME GUSTS UP TO 20 KTS EXPECTED OVER KIWD WHERE GRADIENT TO BE A BIT TIGHTER. MID CLOUDS TO INCREASE AND WINDS BACK TO THE SOUTH TO SOUTHEAST LATE IN THE FORECAST AS AN APPROACHING LOW PRESSURE SYSTEM MOVES THROUGH THE NORTHERN PLAINS. THIS FEATURE COULD BRING AN ISOLATED SHOWER OR THUNDERSTORM TO THE KIWD VICINITY AFTER 0Z THURSDAY. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 325 PM EDT TUE JUN 12 2012 EXPECT NW WINDS UP TO 25-30 KTS INTO THIS EVENING OVER THE E TO DIMINISH OVERNIGHT WITH THE ARRIVAL OF A HI PRES RIDGE. THESE LIGHT WINDS WILL PERSIST INTO WED NIGHT AS THE HI REMAINS DOMINANT. THEN A STRONGER S WIND UP TO 25 KTS WILL IMPACT MAINLY THE NCENTRAL AND E PART OF THE LAKE ON THU/FRI UNDER A TIGHTER PRES GRADIENT BETWEEN THE HI DEPARTING TO THE E AND A LO PRES TROF APPROACHING FROM THE W. THEN LIGHTER WINDS WILL PREVAIL AGAIN THIS COMING WEEKEND WITH A WEAKER PRES GRADIENT FORECAST TO DOMINATE THE UPPER LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FROST ADVISORY UNTIL 7 AM EDT /6 AM CDT/ THIS MORNING FOR MIZ002- 004>007-009>014-084-085. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...MCB AVIATION...RJT MARINE...KC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
446 AM EDT WED JUN 13 2012 .SYNOPSIS... COOLER AND DRIER AIR WILL MOVE IN AS HIGH PRESSURE BUILDS OVER THE GREAT LAKES. DRY CONDITIONS ARE EXPECTED THROUGH THE COMING WEEKEND. NEAR NORMAL TEMPERATURES THURSDAY AND FRIDAY...WILL EDGE UPWARD BY EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 430 AM UPDATE... COLD FRONT...WHICH WAS WELL MARKED BY BAND OF LIGHT SHOWERS...JUST PASSED THROUGH MONTICELLO AND IS CLEARING THE AREA. HOWEVER...NAM AND RUC ARE IN AGREEMENT WITH UPSTREAM SATELLITE IMAGERY...THAT A TEMPORARY SCT TO BKN STRATOCUMULUS DECK WILL MOVE BACK IN AS FINAL VORTICITY LOBE CARRIES THROUGH FROM 11Z NW TO 15Z SE. THESE CLOUDS WILL THEN MIX OUT WITH THE MUCH DRIER AIR MASS ADVECTING IN...ALONG WITH HIGH PRESSURE BUILDING IN FROM WESTERN GREAT LAKES REGION. HIGH TEMPERATURES IN THE WAKE OF THE COLD FRONT WILL BE SLIGHTLY BELOW NORMAL...AND A FRESH NORTHERLY BREEZE WITH GUSTS OF 15 TO 25 MPH WILL HELP TO MAKE THE COOLER AIR MASS MORE APPARENT. MAINLY CLEAR NIGHT TONIGHT...THOUGH SOME UNCERTAINTY AS TO WHETHER AT LEAST A FEW CLOUDS WILL TRY TO HANG ON NEAR POCONOS- CATSKILLS...WHERE WEAK LOW LEVEL CONVERGENCE WILL COINCIDE WITH SOME MOISTURE AROUND 850MB. EITHER WAY...LOOKING AT A COOL NIGHT WITH LOWS IN THE MID 40S TO LOW 50S FOR MOST OF THE AREA...THANKS TO LOW DEWPOINTS AND RADIATIONAL COOLING...WITH A FEW OF THE TYPICAL COLDER SPOTS EVEN GETTING INTO LOWER 40S. ALSO APPEARS TO BE A GOOD SET UP FOR PATCHY FOG IN SOME RIVER VALLEYS SUCH AS IN THE ELMIRA AREA. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... A SLOW UL RIDGING PROCESS WILL BEGIN THIS PERIOD, WITH A STRONG SURFACE HIGH SETTING UP ALONG THE EASTERN SEABOARD. THIS WILL LEAD TO A QUIET WEATHER PATTERN, WITH DAYTIME HIGHS PUSHING INTO THE MIDDLE OR UPPER 70S. OVERNIGHT LOWS WILL DIP INTO THE UPPER 40S AND LOWER 50S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... UL RIDGING WILL CONTINUE, LEADING TO A WARMING TREND. THE WEEKEND WILL BEGIN WITH TEMPERATURES REACHING INTO THE UPPER 70S AND LOWER 80S DURING THE AFTERNOON. BY EARLY NEXT WEEK, THE BUILDING THICKNESS PATTERN WILL PUSH AFTERNOON MAXES INTO THE LOWER AND MIDDLE 80S. THE PATTERN APPEARS DRY, THOUGH WE DO ACCOUNT FOR SOME UNCERTAINTY WITH SLIGHT CHANCE POPS AT THE END OF THE PERIOD WHEN DEW POINTS CLIMB BACK TOWARD 60F. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/... 09Z UPDATE... FRONT HAS MOVED EAST OF THE AREA AS OF 09Z. LOOKING AT MAINLY VFR BEHIND THE FRONT AREAWIDE...AT LEAST INITIALLY. A FINAL WEAK UPPER DISTURBANCE BEHIND THE FRONT...AS CAN NOW BE SEEN BY STRATOCUMULUS UPSTREAM OVER ONTARIO...WILL ALLOW MVFR OR LOW END VFR DECK TO DEVELOP FOR MOST TERMINALS DURING THE 11Z-15Z WINDOW /SEE TAFS FOR TIMING DETAILS/. BECAUSE OF DRYNESS OF INCOMING AIR MASS...NOT EXPECTING IFR DESPITE A COUPLE HILLTOP MODEL SOUNDINGS SUGGESTING IT DURING THAT TIME. AFTER THE EARLY MORNING MVFR...STRATOCUMULUS LIFTS AND MIXES OUT COURTESY OF VERY DRY AIR MASS. NORTHERLY WINDS GUSTING 15-20 KTS DURING THE DAY WITH VFR...THEN DROPPING TO LESS THAN 10 KTS WITH DECOUPLING THIS EVENING. OUTLOOK... LATE WED NIGHT TO SUNDAY...MAINLY VFR. POSSIBLY EARLY MORNING IFR/MVFR VALLEY FOG...MAINLY KELM. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP SHORT TERM...DJP LONG TERM...DJP AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
241 AM EDT WED JUN 13 2012 .SYNOPSIS... IN THE WAKE OF AN OVERNIGHT COLD FRONT...COOLER AND DRIER AIR WILL MOVE IN AS HIGH PRESSURE BUILDS OVER THE GREAT LAKES. MORNING CLOUDS WILL BREAK UP DURING THE DAY...FOLLOWED BY A COOL NIGHT. DRY CONDITIONS ARE EXPECTED THROUGH THE COMING WEEKEND...WITH INITIALLY NEAR NORMAL TEMPERATURES EDGING UPWARD BY EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 2 AM UPDATE... COLD FRONT...WELL MARKED BY BAND OF LIGHT SHOWERS...STRETCHES FROM ONEONTA THROUGH WALTON THROUGH SCRANTON AND WILKES-BARRE JUST BEFORE 2 AM. IT WILL FINISH CLEARING THE AREA BEFORE DAWN. HOWEVER...NAM AND RUC ARE IN AGREEMENT WITH UPSTREAM OBSERVATIONS...THAT A TEMPORARY STRATOCUMULUS DECK WILL MOVE BACK IN AS FINAL VORTICITY LOBE CARRIES THROUGH FROM 10Z NW TO 15Z SE. THESE CLOUDS WILL THEN MIX OUT WITH THE MUCH DRIER AIR MASS ADVECTING IN...ALONG WITH HIGH PRESSURE BUILDING IN FROM WESTERN GREAT LAKES REGION. MAINLY CLEAR NIGHT TONIGHT...THOUGH SOME UNCERTAINTY AS TO WHETHER AT LEAST A FEW CLOUDS WILL TRY TO HANG ON NEAR POCONOS- CATSKILLS...WHERE WEAK LOW LEVEL CONVERGENCE WILL COINCIDE WITH SOME MOISTURE AROUND 850MB. EITHER WAY...LOOKING AT A COOL NIGHT WITH LOWS IN THE MID 40S TO LOW 50S FOR MOST OF THE AREA...THANKS TO LOW DEWPOINTS AND RADIATIONAL COOLING...AND LIGHT NORTHEAST FLOW. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... A SLOW UL RIDGING PROCESS WILL BEGIN THIS PERIOD, WITH A STRONG SURFACE HIGH SETTING UP ALONG THE EASTERN SEABOARD. THIS WILL LEAD TO A QUIET WEATHER PATTERN, WITH DAYTIME HIGHS PUSHING INTO THE MIDDLE OR UPPER 70S. OVERNIGHT LOWS WILL DIP INTO THE UPPER 40S AND LOWER 50S. && .LONG TERM /SATURDAY THROUGH TUESDAY/... UL RIDGING WILL CONTINUE, LEADING TO A WARMING TREND. THE WEEKEND WILL BEGIN WITH TEMPERATURES REACHING INTO THE UPPER 70S AND LOWER 80S DURING THE AFTERNOON. BY EARLY NEXT WEEK, THE BUILDING THICKNESS PATTERN WILL PUSH AFTERNOON MAXES INTO THE LOWER AND MIDDLE 80S. THE PATTERN APPEARS DRY, THOUGH WE DO ACCOUNT FOR SOME UNCERTAINTY WITH SLIGHT CHANCE POPS AT THE END OF THE PERIOD WHEN DEW POINTS CLIMB BACK TOWARD 60F. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... 06Z UPDATE... FRONT MOVING INTO KAVP AT 06Z...AFTER HAVING CLEARED THE REMAINDER OF THE AREA BETWEEN 00Z-06Z. MODELS CONTINUE TO UNDERESTIMATE DRYNESS OF AIRMASS BEHIND THE FRONT...WITH GUIDANCE AND LAMP PROBABILITIES SUGGESTING MVFR OR EVEN IFR FOR MOST SITES THROUGH REMAINDER OF THE NIGHT. INSTEAD...OTHER THAN POSSIBLE BRIEF IFR CIG/VIS WITH NARROW SHOWER BAND IMMEDIATELY ALONG FRONT FOR KAVP 06Z-07Z...LOOKING AT MAINLY VFR BEHIND THE FRONT AREAWIDE...AT LEAST INITIALLY. A FINAL WEAK UPPER DISTURBANCE BEHIND THE FRONT...AS CAN NOW BE SEEN BY STRATOCUMULUS UPSTREAM OVER ONTARIO...WILL ALLOW MVFR DECK TO DEVELOP FOR MOST TERMINALS DURING THE 10Z-14Z WINDOW /SEE TAFS FOR TIMING DETAILS/. BECAUSE OF DRYNESS OF INCOMING AIR MASS...NOT EXPECTING IFR DESPITE A COUPLE HILLTOP MODEL SOUNDINGS SUGGESTING IT DURING THAT TIME. AFTER THE EARLY MORNING MVFR...STRATOCUMULUS LIFTS AND MIXES OUT COURTESY OF VERY DRY AIR MASS. NORTHERLY WINDS GUSTING 15-20 KTS DURING THE DAY WITH VFR...THEN DROPPING TO LESS THAN 10 KTS WITH DECOUPLING THIS EVENING. OUTLOOK... LATE WED NIGHT TO SUNDAY...MAINLY VFR. POSSIBLY EARLY MORNING IFR/MVFR VALLEY FOG AT KELM. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP SHORT TERM...DJP LONG TERM...DJP AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
204 AM EDT WED JUN 13 2012 .SYNOPSIS... IN THE WAKE OF AN OVERNIGHT COLD FRONT...COOLER AND DRIER AIR WILL MOVE IN AS HIGH PRESSURE BUILDS OVER THE GREAT LAKES. MORNING CLOUDS WILL BREAK UP DURING THE DAY...FOLLOWED BY A COOL NIGHT. DRY CONDITIONS ARE EXPECTED THROUGH THE COMING WEEKEND...WITH INITIALLY NEAR NORMAL TEMPERATURES EDGING UPWARD BY EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... 2 AM UPDATE... COLD FRONT...WELL MARKED BY BAND OF LIGHT SHOWERS...STRETCHES FROM ONEONTA THROUGH WALTON THROUGH SCRANTON AND WILKES-BARRE JUST BEFORE 2 AM. IT WILL FINISH CLEARING THE AREA BEFORE DAWN. HOWEVER...NAM AND RUC ARE IN AGREEMENT WITH UPSTREAM OBSERVATIONS...THAT A TEMPORARY STRATOCUMULUS DECK WILL MOVE BACK IN AS FINAL VORTICITY LOBE CARRIES THROUGH FROM 10Z NW TO 15Z SE. THESE CLOUDS WILL THEN MIX OUT WITH THE MUCH DRIER AIR MASS ADVECTING IN...ALONG WITH HIGH PRESSURE BUILDING IN FROM WESTERN GREAT LAKES REGION. MAINLY CLEAR NIGHT TONIGHT...THOUGH SOME UNCERTAINTY AS TO WHETHER AT LEAST A FEW CLOUDS WILL TRY TO HANG ON NEAR POCONOS- CATSKILLS...WHERE WEAK LOW LEVEL CONVERGENCE WILL COINCIDE WITH SOME MOISTURE AROUND 850MB. EITHER WAY...LOOKING AT A COOL NIGHT WITH LOWS IN THE MID 40S TO LOW 50S FOR MOST OF THE AREA...THANKS TO LOW DEWPOINTS AND RADIATIONAL COOLING...AND LIGHT NORTHEAST FLOW. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... A VERY QUIET PERIOD SHAPING UP FOR THE CONCLUSION OF THE WORK WEEK AS HIGH PRESSURE BECOMES FIRMLY ESTABLISHED ACROSS THE FCST AREA. EXPECT TEMPS TO GRADUALLY MAKE A REBOUND BACK INTO THE MIDDLE TO UPPER 70S AS EARLY AS THU AFTERNOON WITH A GRADUAL WARMING TREND THEN ANTICIPATED THROUGH THE UPCOMING WEEKEND AS HIGH PRESSURE SLIDES NORTHEAST OF THE AREA. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... 2 PM UPDATE... VERY QUIET EXTENDED WITH A LARGE SURFACE HIGH ACROSS THE ENTIRE EAST COAST OF THE UNITED STATES THROUGH THE WEEKEND INTO AT LEAST MONDAY AND MAYBE TUESDAY OR WEDNESDAY. A SOUTHWEST FLOW OF MOISTER AIR COULD CAUSE A FEW SHOWERS OR THUNDERSTORMS ON TUESDAY. AS USUAL THAT FAR OUT DIFFERENCES BETWEEN THE MODELS ON TIMING AND STRENGTH. BOTH THE GFS AND ECMWF HAVE A LARGE UPPER LEVEL TROF MOVING INTO THE PLAINS WHILE A STORM IS OFF THE SE US COAST. LONG TERM TEMPERATURES START OUT WITH NEAR NORMAL TEMPERATURES AROUND 80 THAT RISE INTO THE MID TO UPPER 80S NEXT WEEK. DEWPOINT TEMPS SHOULD BE MOSTLY IN THE 50S. EARLY MORNING VALLEY FOG POSSIBLE EACH DAY. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... 06Z UPDATE... FRONT MOVING INTO KAVP AT 06Z...AFTER HAVING CLEARED THE REMAINDER OF THE AREA BETWEEN 00Z-06Z. MODELS CONTINUE TO UNDERESTIMATE DRYNESS OF AIRMASS BEHIND THE FRONT...WITH GUIDANCE AND LAMP PROBABILITIES SUGGESTING MVFR OR EVEN IFR FOR MOST SITES THROUGH REMAINDER OF THE NIGHT. INSTEAD...OTHER THAN POSSIBLE BRIEF IFR CIG/VIS WITH NARROW SHOWER BAND IMMEDIATELY ALONG FRONT FOR KAVP 06Z-07Z...LOOKING AT MAINLY VFR BEHIND THE FRONT AREAWIDE...AT LEAST INITIALLY. A FINAL WEAK UPPER DISTURBANCE BEHIND THE FRONT...AS CAN NOW BE SEEN BY STRATOCUMULUS UPSTREAM OVER ONTARIO...WILL ALLOW MVFR DECK TO DEVELOP FOR MOST TERMINALS DURING THE 10Z-14Z WINDOW /SEE TAFS FOR TIMING DETAILS/. BECAUSE OF DRYNESS OF INCOMING AIR MASS...NOT EXPECTING IFR DESPITE A COUPLE HILLTOP MODEL SOUNDINGS SUGGESTING IT DURING THAT TIME. AFTER THE EARLY MORNING MVFR...STRATOCUMULUS LIFTS AND MIXES OUT COURTESY OF VERY DRY AIR MASS. NORTHERLY WINDS GUSTING 15-20 KTS DURING THE DAY WITH VFR...THEN DROPPING TO LESS THAN 10 KTS WITH DECOUPLING THIS EVENING. OUTLOOK... LATE WED NIGHT TO SUNDAY...MAINLY VFR. POSSIBLY EARLY MORNING IFR/MVFR VALLEY FOG AT KELM. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...MDP NEAR TERM...MDP SHORT TERM...CMG LONG TERM...TAC AVIATION...MDP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
254 AM EDT WED JUN 13 2012 .SYNOPSIS... A COLD FRONT WILL MOVE SLOWLY ACROSS THE AREA TODAY BRINGING WITH IT MORE RAIN. HIGH PRESSURE WILL BUILD IN THURSDAY AND MAINTAIN A RELATIVELY COOL AND DRY PATTERN THROUGH EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1005 PM TUESDAY...DECENT CLUSTER OF SHOWERS AND THUNDERSTORMS EXTENDS ACROSS THE SE NC COASTAL COUNTIES AND THE ADJACENT COASTAL AND OFFSHORE WATERS. MOVEMENT IS TO THE ENE NEAR 15 MPH. VIA LATEST KLTX RAINFALL ESTIMATES...LOOK FOR AN ADDITIONAL ONE TENTH TO ONE QUARTER OF AN INCH...EXCEPT ONE HALF TO 1 INCH FROM ANY OF THE STRONGER SHOWERS AND STORMS. THIS CLUSTER/AREA SHOULD TRACK NE OF THE AREA BY MIDNIGHT TO 1 AM. THE DEEP PLUME OF MOISTURE FROM THE TROPICS IS SLOWLY BEING CUT OFF AS THE MID-UPPER LEVEL TROF REACHES THE EASTERN CAROLINAS...VIA THE LATEST NEAR TERM RUC MODEL HOURLY RUNS. AS A RESULT...THE BEST CHANCES FOR PCPN AND THE ORIENTATION OF OVERNIGHT POPS ACROSS THE ILM CWA...WILL CONTINUE TO BE GEARED ALONG THE COASTAL COUNTIES AND ADJACENT COASTAL/OFFSHORE WATERS. THE 5H VORT ACROSS SOUTHERN GA IS PROGGED TO TRACK OFF THE GA COAST LATE THIS EVENING AND OVERNIGHT AND SHOULD NOT BE A PROBLEM FOR THE ILM CWA. WILL HAVE TO MAINLY DEAL WITH THE APPROACH OF FRONTAL DYNAMICS AND ANY SHEARED MID LEVEL VORTS ACCOMPANYING IT FOR THE CONTINUED POPS OVERNIGHT. TWEAKED MIN TEMPS UPWARDS BY A DEGREE OR 2 BASED ON LATEST TRENDS AND A PEAK LOOK AT THE NEW 00Z GUIDANCE. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3:00 AM WEDNESDAY...MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE TEMPERATURES AS MOISTURE WILL BE ON THE DECREASE AS AN OMEGA CONFIGURATION DEVELOPS AT THE MID LEVELS. AT THE SURFACE A FORMIDABLE NORTHEAST FLOW WILL DEVELOP AS HIGH PRESSURE BUILDS DOWN FROM THE NORTHEAST AND LOW PRESSURE MEANDERS NEAR BERMUDA. MET GUIDANCE IS QUITE A BIT WARMER AS OPPOSED TO THE MAV NUMBERS THROUGH THE PERIOD MORE-SO THURSDAY. THIS APPEARS TO BE A FUNCTION OF LINGERING LOW LEVEL MOISTURE VIA THE GFS. NUMBERS JOG TOWARD SLIGHTLY BETTER AGREEMENT FRIDAY. HAVE LEANED TOWARD THE COOLER MAV NUMBERS OPTING FOR A SLOWER PROGRESSION OF THE LOW LEVEL MOISTURE. NO POPS THROUGH THE PERIOD. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3:00 AM WEDNESDAY...NO SIGNIFICANT CHANGES TO THE MEDIUM RANGE GUIDANCE THIS MORNING AS THE FORECAST AREA CONTINUES TO BE SITUATED IN THE EASTERN PART OF A MID LEVEL OMEGA PATTERN FOR MOST OF THE PERIOD. I DID INCREASE THE POPS INCREMENTALLY SUNDAY AND MONDAY TO SLIGHT CHANCE TO MATCH HPC AND ADJACENT OFFICES VIA NORTHEAST RESULTANT SEA BREEZE COMBINED WITH THE 700MB SUBSIDENCE INVERSION ABATING. THE PATTERN BEGINS TO CHANGE LATE IN THE PERIOD WITH THE GFS ADVERTISING A REX BLOCK DEVELOPING SO CONFIDENCE IS BELOW AVERAGE. NO CHANGES TO TEMPERATURE FORECAST. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...A VARIETY OF CLOUD DECKS EXPECTED OVERNIGHT FROM UPSTREAM CONVECTIVE DEBRIS TO AREAS OF STRATUS AND STRATO-CUMULUS. AS A RESULT...CIGS AND VSBYS WILL VARY FROM IFR TO VFR THROUGH AROUND SUNRISE. IFR/MVFR CIGS AND VSBYS WILL IMPROVE ALL AREAS OUTSIDE OF CONVECTION THEREAFTER. WILL ALSO INCLUDE TEMPO SHOWERS AT KLBT 08-10Z AS UPSTREAM CONVECTION CONTINUES TO WEAKEN AS IT MOVES TO THE SOUTH. CONVECTION IS EXPECTED TO BECOME SCATTERED ONCE DAYTIME HEATING PEAKS IN THE AFTERNOON. WINDS WILL BE LIGHT AND VARIABLE NEAR THE FRONTAL BOUNDARY...BUT FOR THE MYRTLES...THE SEA BREEZE WILL LIKELY DOMINATE IN THE AFTERNOON ALLOWING WINDS TO TURN ONSHORE. EXTENDED OUTLOOK...VFR THROUGH THE FORECAST PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1005 PM TUESDAY...SCEC WILL BE ALLOWED TO EXPIRE AT MIDNIGHT FOR THE ILM NC WATERS. UNTIL THE COLD FRONT REACHES THE COASTAL WATERS WHICH WILL LIKELY BE CLOSER TO DAYBREAK WED...THE SFC PG AND PATTERN AHEAD OF IT WILL YIELD SW WINDS AROUND 15 KT...OCCASIONALLY UP TO 20 KT FOR THE LOCAL WATERS OFF CAPE FEAR. AS THE FRONT MOVES CLOSER WINDS WILL VEER TO THE WSW TOWARD DAYBREAK AND DROP TO 10 TO 15 KT. SIGNIFICANT SEAS WILL RUN 3 TO 4 FT...UP TO 5 FT ACROSS THE LOCAL WATERS OFF CAPE FEAR THROUGH MIDNIGHT. DOMINANT PERIODS WILL BE AROUND 6 SECONDS. WIND DRIVEN WAVES WILL DOMINATE SIG SEAS WITH A CONTINUED UNDERLYING 1 TO 1.5 FT ESE 9-10 SECOND PERIOD GROUND SWELL. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3:00 AM WEDNESDAY...A NORTHEASTERLY FLOW WILL PREVAIL THROUGHOUT THE PERIOD AS HIGH PRESSURE BUILDS DOWN FROM THE NORTHEAST AND LOW PRESSURE SLOWLY DEVELOPS WELL INTO THE ATLANTIC. STRONGEST WINDS OCCUR LATE FRIDAY WHEN THE 20-25 KNOT RANGE WILL LIKELY BE CLOSER TO THE HIGH END OF THE RANGE. THE PERSISTENT FETCH WILL ALLOW SEAS TO BUILD LATE THURSDAY TO ECLIPSE THE SIX FOOT SMALL CRAFT CRITERIA AND CONTINUE THROUGH THE REMAINDER OF THE PERIOD. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3:00 AM WEDNESDAY...ESSENTIALLY NO CHANGES TO THE EXTENDED COASTAL WATERS FORECAST AS A NORTHEASTERLY FLOW SHOULD PREVAIL. MAY SEE MORE VEERING SUNDAY AFTERNOON AS THE FLOW IS LIGHTER ALLOWING MORE OF A NORTHEAST RESULTANT TO DEVELOP. THE CAVEAT WITH THIS TYPE OF SCENARIO ARE THE EMBEDDED SURGES. I DID WALK BACK SEAS SLIGHTLY BUT A SMALL CRAFT ADVISORY MAY STILL BE NEEDED BUT IT APPEARS MORE MARGINAL AT THIS POINT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...MBB SHORT TERM...SHK LONG TERM...SHK AVIATION...RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
144 AM EDT WED JUN 13 2012 .SYNOPSIS... A COLD FRONT WILL MOVE SOUTHEAST AND ACROSS THE EASTERN CAROLINAS WEDNESDAY...MOVING OFFSHORE WEDNESDAY NIGHT. SHOWERS AND THUNDERSTORMS WILL END AS THE FRONT MOVES OFFSHORE. LOW PRESSURE SHOULD DEVELOP ALONG THE FRONT THURSDAY...BRINGING NORTHEAST WINDS AND MILD TEMPERATURES TO THE CAROLINAS THURSDAY INTO SATURDAY. HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHEAST EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1005 PM TUESDAY...DECENT CLUSTER OF SHOWERS AND THUNDERSTORMS EXTENDS ACROSS THE SE NC COASTAL COUNTIES AND THE ADJACENT COASTAL AND OFFSHORE WATERS. MOVEMENT IS TO THE ENE NEAR 15 MPH. VIA LATEST KLTX RAINFALL ESTIMATES...LOOK FOR AN ADDITIONAL ONE TENTH TO ONE QUARTER OF AN INCH...EXCEPT ONE HALF TO 1 INCH FROM ANY OF THE STRONGER SHOWERS AND STORMS. THIS CLUSTER/AREA SHOULD TRACK NE OF THE AREA BY MIDNIGHT TO 1 AM. THE DEEP PLUME OF MOISTURE FROM THE TROPICS IS SLOWLY BEING CUT OFF AS THE MID-UPPER LEVEL TROF REACHES THE EASTERN CAROLINAS...VIA THE LATEST NEAR TERM RUC MODEL HOURLY RUNS. AS A RESULT...THE BEST CHANCES FOR PCPN AND THE ORIENTATION OF OVERNIGHT POPS ACROSS THE ILM CWA...WILL CONTINUE TO BE GEARED ALONG THE COASTAL COUNTIES AND ADJACENT COASTAL/OFFSHORE WATERS. THE 5H VORT ACROSS SOUTHERN GA IS PROGGED TO TRACK OFF THE GA COAST LATE THIS EVENING AND OVERNIGHT AND SHOULD NOT BE A PROBLEM FOR THE ILM CWA. WILL HAVE TO MAINLY DEAL WITH THE APPROACH OF FRONTAL DYNAMICS AND ANY SHEARED MID LEVEL VORTS ACCOMPANYING IT FOR THE CONTINUED POPS OVERNIGHT. TWEAKED MIN TEMPS UPWARDS BY A DEGREE OR 2 BASED ON LATEST TRENDS AND A PEAK LOOK AT THE NEW 00Z GUIDANCE. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...THE BAND OF DEEP TROPICAL MOISTURE WILL BEGIN TO NUDGE OFFSHORE WEDNESDAY AS THE 500 MB UPPER TROUGH BEGINS TO KICK EAST AND FINALLY OFF THE COAST WEDNESDAY NIGHT. THE SURFACE COLD FRONT WILL ACCOMPANY THE UPPER TROUGH TO THE COAST WEDNESDAY AFTERNOON...BUT A WEAK SEABREEZE WILL HOLD UP THE FRONT`S EASTWARD PROGRESS UNTIL EVENING. THE HIGHEST CHANCES FOR SHOWERS AND STORMS WEDNESDAY WILL OCCUR NEAR THE COAST WHERE ENHANCED LOW-LEVEL CONVERGENCE WILL COEXIST WITH THE LINGERING TROPICAL HIGH-PRECIPITABLE WATER ATMOSPHERE. CONVECTIVE COVERAGE SHOULD RANGE FROM 50-60 PERCENT ALONG THE COAST TO ONLY 20-30 PERCENT ALONG AND WEST OF INTERSTATE 95. UNLIKE TODAY...WEDNESDAY`S STORM MOTION SHOULD BE FROM NORTH TO SOUTH AS THE MID-LEVEL FLOW SHIFTS BEFORE THE SURFACE FRONT ARRIVES. DRIER AIR SHOULD OVERSPREAD THE REGION FROM NW TO SE WEDNESDAY NIGHT WITH MODEL PRECIP WATER VALUES DROPPING FROM ~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`S PROGRESS EAST. SCATTERED SHOWERS AND STORMS WILL ACCOMPANY THE SLOW-MOVING FRONT WEDNESDAY. THE FRONT WILL RESUME ITS OFFSHORE MOVEMENT DURING THE EVENING AND SHOULD MOVE WELL OFFSHORE WEDNESDAY NIGHT. THE 12Z NAM HAS COME INTO AGREEMENT WITH YESTERDAY`S GFS (AND TODAY`S GFS AS WELL) SHOWING THE DEVELOPMENT OF MULTIPLE CENTERS OF LOW PRESSURE OFFSHORE THURSDAY ALONG THE FRONT. THE EXACT LOCATION OF THESE LOWS ARE NOT AS IMPORTANT AS THE OVERALL IMPACT ON TIGHTENING OUR LOCAL PRESSURE GRADIENT THURSDAY AFTERNOON INTO THURSDAY NIGHT WITH A SUBSTANTIAL INCREASE IN WIND SPEEDS EXPECTED ALONG THE COAST. OUR LATEST FORECAST INCREASES WINDS INTO THE 20-25 KT RANGE THURSDAY NIGHT WITH THE POTENTIAL FOR GUSTS APPROACHING 30 KT LATE. THIS WILL BUILD SEAS FROM A GENTLE 2-3 FT WEDNESDAY...TO AS HIGH AS 6-8 FEET NORTH AND EAST OF CAPE FEAR LATE THURSDAY NIGHT. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...PERSISTENT NORTHEAST FLOW IS EXPECTED OVER THE WATERS AS SURFACE HIGH PRESSURE EXTENDS SOUTHWARD ACROSS THE INLAND CAROLINAS...AND A TROUGH LINGERS WELL OFFSHORE. A MODERATE PRESSURE GRADIENT ACROSS THE WATERS WILL LIKELY KEEP WINDS IN A 15-25 KT RANGE...AND A PERSISTENT FETCH SHOULD ALLOW SEAS TO BUILD AS HIGH AS 5-7 FT IN THE 10-20 NM RANGE. SMALL CRAFT ADVISORY THRESHOLDS WILL BE APPROACHED...IF NOT EXCEEDED AT TIMES FRIDAY AND SATURDAY...ESPECIALLY ACROSS THE NORTH CAROLINA COASTAL WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH SHORT TERM...TRA LONG TERM...CRM AVIATION...SRP/RJD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
429 AM CDT WED JUN 13 2012 .SHORT TERM...NOW THROUGH THURSDAY AFTERNOON... THE MAIN PROBLEM OF THE DAY IS CONCERNED WITH THE POTENTIAL FOR SEVERE WEATHER LATER TODAY. THE DAY 1 STORM PREDICTION CENTER DISCUSSION REFERENCES THUNDERSTORMS FORMING ALONG A SURFACE COLD FRONT PUSHING INTO THE WESTERN DAKOTAS THIS AFTERNOON...BUT DOWNPLAYS DAYTIME SEVERE POTENTIAL DUE TO LIMITED INSTABILITY. THE 00/06 UTC NAM DEPICTS A LINE OF STRONGER THUNDERSTORMS FORMING...OR STRENGTHENING OF ONGOING CONVECTION...ALONG A LINE FROM MOBRIDGE SOUTH DAKOTA TO VALLEY CITY NORTH DAKOTA BETWEEN 06 AND 09 UTC THURSDAY MORNING. GREATER INSTABILITY IN THIS REGION AND FAVORABLE LOW-LEVEL JET SUPPORT SUGGEST THAT STORMS ARE MORE LIKELY TO BECOME SEVERE THEN...WHICH AGREES WITH THE STORM PREDICTION CENTER SLIGHT RISK AREA. THE 06 UTC HRRR DOES INITIATE AT LEAST MODERATE CONVECTION ON THE MISSOURI SLOPE AT 19 UTC TODAY...BUT IT HAS DIFFICULTY SUSTAINING IT...WHICH IS CONSISTENT WITH LESS THAN FAVORABLE INSTABILITY PARAMETERS. OTHERWISE...GUSTY POST FRONTAL WESTERLIES MAY APPROACH LOWER WIND ADVISORY CRITERIA THURSDAY AFTERNOON. .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY... A BREAK IN THUNDERSTORM ACTIVITY FOR NORTH DAKOTA THURSDAY NIGHT AS ONE SHORTWAVE EXITS THE AREA AND THE NEXT DISTURBANCE MOVES ACROSS THE ROCKIES. AN ACTIVE WEATHER PATTERN CONTINUES THROUGH THE REST OF THE LONG TERM PERIOD. MODELS IN FAIRLY GOOD AGREEMENT FRIDAY AND SATURDAY WITH SEVERAL SHORTWAVES MOVING THROUGH THE STATE WITH A PROGRESSIVE SERIES OF DISTURBANCES. BY SUNDAY THE OVERALL SYNOPTIC WEATHER PATTERN IS DOMINATED BY A RELATIVELY PERSISTENT BROAD UPPER LEVEL LOW OVER CENTRAL CANADA...WHICH ALSO BRINGS SEVERAL UPPER LEVEL SHORTWAVES MOVING ACROSS THE NORTHERN PLAINS...KEEPING A CHANCE OF PRECIPITATION EACH DAY THROUGH EARLY NEXT WEEK. THE OVERALL TEMPERATURE TREND IS FOR AVERAGE TEMPERATURES IN THE 70S TO LOWER 80S FRIDAY...COOLING BY MONDAY TO THE LOW TO MID 70S. && .AVIATION... SOUTHERLY SURFACE WINDS TODAY AHEAD OF A COLD FRONT THAT IS FORECAST TO ENTER WESTERN NORTH DAKOTA AFTER 18Z. IFR CIGS IN SOUTH DAKOTA THIS MORNING ARE EXPECTED TO MOVE INTO THE KBIS/KJMS TAF SITES FOR A FEW HOURS THIS MORNING...THEN SCATTER OUT FROM WEST TO EAST. WILL WAIT FOR FINAL DETERMINATION ON THIS CLOSER TO TAF ISSUANCE TIME. THE SURFACE COLD FRONT WILL BE ACCOMPANIED BY AN UPPER LEVEL SHORTWAVE...WHICH WILL CREATE INCREASINGLY UNSTABLE CONDITIONS AND WILL MENTION THUNDERSTORMS WITH VCTS GROUPS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SCHECK LONG TERM/AVIATION....JV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 AM CDT WED JUN 13 2012 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT 325 AM CDT WED JUN 13 2012 MAIN FORECAST CONCERN DEALS WITH RAIN CHANCES TODAY THROUGH FRIDAY NIGHT. WATER VAPOR IMAGERY AND RAP ANALYSIS AT 2 AM SHOWS A DISTINCT MID-LEVEL CYCLONIC CIRCULATION MOVING EAST ACROSS CENTRAL SD. MOISTURE TRANSPORT AND ISENTROPIC LIFT AHEAD OF THE WAVE AIDING IN SHOWERS AND ISOLATED THUNDERSTORMS ACROSS EASTERN SD/NEB...INTO NORTHWEST IA. CLOSER TO HOME OVER OUR FORECAST AREA...HIGH CLOUDS FROM THE DAKOTAS WAVE STREAMING IN WITH CENTER OF HIGH PRESSURE ACROSS CENTRAL WI INTO CENTRAL LOWER MI. LIGHT WINDS AND PARTLY CLOUDY CONDITIONS HAS ALLOWED TEMPERATURES TO DIP TO 37 DEGREES AT BLACK RIVER FALLS WI...WHILE OTHER LOCATIONS RANGED FROM THE 40S TO THE LOWER 50S UNDER MORE CLOUD COVER. 13.00Z NCEP MODEL SUITE/ECMWF/GEM GENERALLY IN GOOD AGREEMENT THROUGH THE SHORT TERM PERIOD. FOR TODAY...WILL BE WATCHING THAT MID-LEVEL WAVE OVER SD MOVES INTO CENTRAL MN THROUGH THIS AFTERNOON. MODELS CONCENTRATE MAIN AXIS OF ASSOCIATED 850MB MOISTURE TRANSPORT NORTHWEST INTO MN WITH OUR AREA JUST ON THE EASTERN FRINGES. MEANWHILE...DECENT AMOUNT OF ISENTROPIC LIFT INTO THE AREA FOR MID-CLOUD/ACCAS GENERATION. KEPT SMALL CHANCES OF SHOWERS MAINLY NORTHWEST OF A LINE FROM MEDFORD AND ARCADIA WI...TO ROCHESTER AND AUSTIN MN. OTHERWISE...WITH INCREASING CLOUD COVER EXPECTED...HIGHS TODAY ARE EXPECTED TO TOP OFF IN THE LOWER TO MIDDLE 70S. TONIGHT...ANOTHER MID-LEVEL WAVE AND SURFACE CYCLOGENESIS WILL TAKE PLACE OVER NEB/SD WITH MOISTURE TRANSPORT/ISENTROPIC LIFT IMPINGING ON THE WESTERN PORTIONS OF THE FORECAST AREA. PLANNING ON ISOLATED SHOWER AND ISOLATED THUNDER //WITH INCREASING ELEVATED MUCAPE// NORTHWEST OF A MEDFORD-ARCADIA-ROCHESTER-AUSTIN LINE AGAIN IN THE EVENING...THEN INCREASING SLIGHTLY IN COVERAGE/SPREADING EAST INTO THE REST OF THE AREA AFTER MIDNIGHT AS 850MB MOISTURE TRANSPORT VECTORS BEND MORE INTO THE AREA. RAINFALL LOOKS VERY LIGHT WITH GENERALLY LESS THAN 5 HUNDRETHS OF AN INCH EXPECTED. ON THURSDAY...LOOK FOR THE MID-LEVEL WAVE/SURFACE COLD FRONT TO MOVE INTO MN WITH INCREASING 850MB MOISTURE TRANSPORT INTO THE AREA. 0-3KM MLCAPE INCREASES INTO THE 1000-1500J/KG RANGE ALONG AND AHEAD OF THE FRONT JUST TO OUR WEST WITH RESPECTABLE 20-30KT 0-3KM BULK SHEAR. THEREFORE...EXPECTING STRONGER THUNDERSTORM ACTIVITY ALONG THE FRONT BY AFTERNOON WITH EASTERN FRINGES OF THIS ACTIVITY PERHAPS MAKING IT INTO NORTHWEST PORTIONS OF THE FORECAST AREA. FOR NOW...WILL STICK WITH 20-40 PERCENT SHOWER/THUNDERSTORM CHANCE NORTHWEST OF A SPARTA-VIROQUA-OELWEIN LINE. OTHERWISE...LOOK FOR HIGH TEMPERATURES IN THE UPPER 70S TO LOWER 80S. FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT...LOOK FOR THE COLD FRONT OVER MN TO SINK INTO THE AREA WHILE WEAKENING. MEANWHILE...MODELS SHOWING A COUPLE MID-LEVELS WAVE EJECTING NORTHEAST TOWARD/ACROSS THE AREA WITH BOUTS OF LIFT/MOISTURE TRANSPORT. BASED ON THIS SIGNAL...WILL GO WITH 30-50 SHOWER/THUNDERSTORM CHANCES FOR NOW FOR THIS PERIOD. .LONG TERM...SATURDAY THROUGH TUESDAY 325 AM CDT WED JUN 13 2012 13.00Z GFS/ECMWF SHOWING SOUTHWEST FLOW ALOFT INTO THE AREA THROUGH THE PERIOD AS HIGH PRESSURE ANCHORS IN ACROSS THE EASTERN CONUS AND A TROUGH SLOWLY MAKES ITS WAY ACROSS THE INTERMOUNTAIN WEST INTO THE PLAINS. SIGNAL AGREEMENT BETWEEN THE MODELS SEEMS TO BE GETTING STRONGER FOR PERIODIC SHOWER/THUNDERSTORM CHANCES THROUGH THE WEEKEND. BOTH MODELS THEN BRING IN A DEEPER TROUGH/STRONGER SURFACE COLD FRONT INTO THE AREA MONDAY THROUGH TUESDAY FOR CONTINUED SHOWER/THUNDERSTORM CHANCES. && .AVIATION...THROUGH 06Z THURSDAY 1145 PM CDT TUE JUN 12 2012 SURFACE HIGH PRESSURE OVER EASTERN WISCONSIN WILL CONTINUE TO DRIFT EASTWARD OVERNIGHT AND WEDNESDAY. HIGH CLOUDS WERE ALREADY WORKING THEIR WAY ACROSS MINNESOTA ON THE BACKSIDE OF THE HIGH AND WILL CONTINUE TO OVERSPREAD THE TAF SITES TONIGHT. CEILINGS WILL LOWER INTO THE 8K-12K FOOT RANGE AFTER 12Z. THE EDGE OF THE MOISTURE TRANSPORT DOES CLIP SOUTHEAST MINNESOTA LATER WEDNESDAY AND THUS EXPECT SOME SCATTERED SHOWERS. CONFIDENCE NOT HIGH THAT THESE WILL IMPACT THE TAF SITES. SLIGHTLY BETTER CHANCES AFTER 00Z AS MOISTURE CONTINUES TO INCREASE. DID ADD MENTION OF VCSH AT KRST AFTER 00Z AND AT KLSE AFTER 03Z. OTHERWISE...EXPECT SOUTHERLY WINDS TO GUST TO BETWEEN 20 AND 25 KNOTS AT KRST DURING THE AFTERNOON HOURS WEDNESDAY. && .ARX WATCHES/WARNINGS/ADVISORIES... 325 AM CDT WED JUN 13 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
940 AM MDT WED JUN 13 2012 .UPDATE...NO CHANGES TO THE GRIDS AT THIS TIME. THE LATEST NAM12 FCST SOUNDINGS DOES INDICATE SOME MINIMAL CAPE AROUND 200 J/KG THIS AFTN. NOT ENOUGH FOR TSTMS BUT BY ENOUGH TO PRODUCE SOME WEAK CB BUILDUPS AND BRIEF GUSTY OUTFLOW WINDS. THE 12Z HRRR DEVELOPS MINIMAL CELL COVERAGE AS WELL THIS AFTN WITH THE ACTIVITY EAST OF THE DENVER AREA. OVERALL HOT AND DRY THE GOING THEME. WINDS AT THE HIGH PARK WILDFIRE MAY BE SIMILAR TO YESTERDAY WITH W-SWLY WINDS ON THE WEST SIDE...WITH MORE OF AN E-SELY COMPONENT ON THE EAST SIDE. THE WINDS OVER THE BURN AREA MAY BECOME W-SWLY ON THE EAST SIDE IN THE AFTN...AFTER 20Z. IN SPITE OF THE HOT AND DRY CONDITIONS...WILL HOLD OFF ON ISSUING ANY FIRE WEATHER HIGHLIGHT DUE TO THE LACK OF A STRONG SFC WIND COMPONENT. && .AVIATION...VFR CONDITIONS OVER THE NEXT 24 HRS. THE MDLS DO HINT AT SOME CELL DEVELOPMENT THIS AFTN...BUT WEAK AND EAST OF THE DENVER AREA. SOME WEAK CB BUILDUPS NEAR D.I.A. COULD PRODUCE BRIEF GUSTY OUTFLOW WINDS TO 25 KTS...BUT NOT ENOUGH CONFIDENCE TO ADD IT TO THE TAF. A DRY COLD FRONT IS STILL PROGGED TO PUSH THROUGH THE DENVER AREA OVERNIGHT...COULD BE SOONER...IN THE 09-12Z TIME FRAME SO MAY ADJUST THE TIMING IN THE 18Z TAF ISSUANCE. ESELY WINDS PROGGED THE LOW LEVEL MOISTURE ADVECTING INTO THE DENVER AREA THROUGH THE DAY WEDNESDAY...SO THE PROSPECTS OF THUNDERSTORMS BETTER IN THE AFTN SO WL ADD VCTS TO THE OUTLOOK PERIOD FOR D.I.A. && .PREV DISCUSSION... /ISSUED 259 AM MDT WED JUN 13 2012/ SHORT TERM...THERE IS A CONTINUED MODERATE WESTERLY FLOW ALOFT ACROSS COLORADO TODAY...WHICH WILL BE GRADUALLY SHIFTING MORE SOUTHWESTERLY LATER TODAY AND TONIGHT. THE AIRMASS CONTINUES ON A DRYING AND WARMING TREND. 700MB TEMPS RISE TO AROUND +16C AT DENVER AND THIS WILL RESULT IN ANOTHER 4-6 DEGREES OF WARMING TODAY. END RESULT WILL BE TEMPERATURES WELL INTO THE 90S ACROSS LOWER ELEVATIONS. THE RECORD FOR DENVER TODAY IS 99 SO SHOULD BE WELL SHORT OF THAT. FORECAST SOUNDINGS SHOW SOME MIDDLE LEVEL MOISTURE BY LATER IN THE DAY BUT EXTREMELY DRY LOW LEVELS SHOULD RESULT IN NO STORMS TODAY. THE ONLY EXCEPTION WOULD BE OVER THE FAR EASTERN PLAINS OVER LINCOLN COUNTY TOWARDS EVENING WHERE LOW LEVEL MOISTURE WOULD BE A BIT HIGHER. NOT EVEN THRILLED WITH CHANCES OUT THERE BUT WILL LEAVE IN AN EVER SO SLIGHT CHANCE. IN TERMS OF FIRE WEATHER CONCERNS IT WILL CERTAINLY BE WARM WITH LOW HUMIDITIES 10-15 PERCENT BUT WIND GUSTS WILL GENERALLY BE BELOW THRESHOLD NEEDED FOR ANY FIRE WEATHER HILITES. A FEW GUSTS IN THE 15-25 MPH RANGE CERTAINLY BUT NOT SUSTAINED AND WIDESPREAD ENOUGH TO WARRANT ANY BIG FIRE CONCERNS. WIND SPEEDS SHOULD BE SIMILAR TO YESTERDAY OVER MOUNTAINS AND FOOTHILLS. LONG TERM...THURSDAY STARTS OUT WITH THE HIGH PLAINS CAPPED BY A SHALLOW FRONTAL INVERSION WHICH IS TOPPED BY A WARM AND DRY WESTERLY FLOW ASSOCIATED WITH A PASSING MID-LEVEL SHORTWAVE RIDGE. LIGHT POST-FRONTAL EAST-NORTHEASTERLY WINDS ON THE PLAINS ARE PROGGED TO TURN SOUTHEASTERLY LATE IN THE DAY WHICH ADVECTS INCREASING AMOUNTS OF LOW-LEVEL MOISTURE UP AGAINST THE FRONT RANGE DURING THE EVENING HOURS. THE RESULTANT DESTABILIZATION MAY CAUSE A FEW GUSTY SHOWERS/T-STORMS TO FORM OVER AND NEAR THE FRONT RANGE DURING THE EVENING. UNFORTUNATELY DO NOT SEE MUCH IN THE WAY OF WETTING RAINFALL FROM THIS HIGH BASED CONVECTION. SO LIGHTNING MAY POSE A THREAT FOR NEW FIRE IGNITIONS WHERE FUELS REMAIN QUITE DRY. OVERNIGHT...MODELS SHOW LOW-LEVEL MOISTURE CONTINUING TO FLOW INTO THE AREA ON SOUTHEASTERLY BOUNDARY LAYER WINDS... POSSIBLY RESULTING IN POCKETS OF FOG TOWARDS MORNING. ON FRIDAY...PATCHY FOG ON THE PLAINS IS EXPECTED TO BURN OFF BY MID-MORNING WITH STRONG SOLAR HEATING. MODELS THEN SHOW A WEAK SHORTWAVE TROUGH OVER THE 4-CORNERS AREA PASSING OVER THE FORECAST AREA LATE IN THE DAY. COULD SEE CONVECTION BEGINNING IN THE HIGH COUNTRY...NOT LONG AFTER MIDDAY WITH THE APPROACHING SHORTWAVE. HOWEVER STORM COVERAGE IN THE HIGH COUNTRY PROBABLY NO MORE THAN ISOLATED IN COVERAGE DUE TO A LACK OF MID-LEVEL MOISTURE. AS THE LIFT GENERATED BY THIS WAVE INTERACTS WITH THE RELATIVELY MOIST AND UNSTABLE AIR MASS ON THE PLAINS...COULD SEE ISOLATED TO SCATTERED T-STORMS DEVELOPING DURING THE LATE AFTERNOON AND EVENING HOURS. DOES NOT LOOK FAVORABLE FOR SEVERE WEATHER...BUT CAN/T RULE OUT AN ISOLATED SEVERE STORM WITH MOISTURE AROUND THIS TIME OF YEAR. LATER THAT NIGHT MAY SEE PATCHING FOG FORMING AGAIN ON THE PLAINS ACCORDING TO THE NAM. ON SATURDAY...MODELS SHOW THE DEEP UPPER LOW/TROUGH OVER THE DESERT SOUTHWEST RETROGRADING WHICH ALLOWS A SECONDARY TROUGH TO DROP SOUTH OUT OF IDAHO AND WESTERN WYOMING. MODELS SHOW THE LEADING EDGE OF SLIGHTLY COOLER AND MORE MOIST AIR MASS SLIPPING INTO NORTHEAST COLORADO DURING THE MORNING. THIS PUSH LOOKS STRONGEST ON THE NAM. AS THE UPPER TROUGH SWINGS EAST ACROSS WYOMING AND NORTHERN COLORADO DURING THE DAY...QG VERTICAL VELOCITY FIELDS INDICATE WEAK UPPER MOTION OVER NORTHEAST COLORADO DURING THE AFTERNOON AND EVENING HOURS. MODELS ALSO INDICATE AREAS OF LIGHT QPF. THERE IS A SLIGHT CHANCE WE COULD SEE A SEVERE STORM OR TWO ALONG A FRONTAL BOUNDARY WHICH THE NAM AND CANADIAN GEM SHOW STRADDLED ACROSS THE NORTHEAST CORNER OF COLORADO AROUND 00Z/SUN. CURRENT FORECAST GRIDS INDICATE 20-30 PERCENT POPS ACROSS THE AREA SATURDAY AFTERNOON AND EVENING. SEE LITTLE REASON TO CHANGE THEM AT THIS TIME. SUNDAY-TUESDAY...WITH THE UPPER TROUGH PASSING OVERHEAD SATURDAY NIGHT...FLOW BOTH SFC AND ALOFT BECOME ZONAL ON SUNDAY...RESULTING IN DRIER AND WARMER CONDITIONS AREA WIDE. HOWEVER THE GFS IS SLOW TO DRY THINGS OUT EAST OF THE MTNS AS IT CONTINUES TO SHOW A RELATIVELY MOIST SOUTH-SOUTHEAST LOW-LEVEL FLOW FOR MOST OF THE DAY. WHILE AT THE SAME TIME IT SHOWS ZONAL FLOW ALOFT WITH WAVES OF MID-LEVEL MOISTURE PASSING BY DURING THE DAY. FOR NOW WILL LEAVE OUT ANY MENTION OF PRECIP ON SUNDAY. FOR MONDAY AND TUESDAY... CONFIDENCE IN THE MODELS WAINS AS A FAST NORTHWESTERLY FLOW ON THE BACK SIDE OF THE PASSING TROUGH MAKES IT DIFFICULT TO PIN DOWN THE TIMING OF WEAK MID-LEVEL DISTURBANCES WHICH MODELS SHOW PASSING OVERHEAD. SO WILL KEEP THINGS GENERALLY DRY WITH NEAR TO SLIGHTLY ABOVE AVERAGE TEMPERATURES. AVERAGE TEMPERATURE FOR DENVER ON THE MON/18TH AND TUE/19TH IS 83 AND 84...RESPECTIVELY. AVIATION...LIGHT DRAINAGE WINDS THIS MORNING WILL GRADUALLY SHIFT MORE SOUTHEAST LATER THIS AFTERNOON. VFR CONDITIONS THROUGH TONIGHT. SOME SCT-BKN MIDDLE AND HIGH LEVEL MOISTURE LATER TODAY BUT NO STORMS EXPECTED. THE NEXT COLD FRONT WILL MOVE THROUGH TERMINALS THURSDAY MORNING...BETWEEN 12-15Z AS WINDS SHIFT NORTHERLY. A DRY FRONT SO NO STRATUS/FOG IS EXPECTED AT THIS TIME. HYDROLOGY...NO ISSUES THROUGH TONIGHT WITH A DRY FORECAST. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...COOPER LONG TERM....BAKER AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS LINCOLN IL
948 AM CDT WED JUN 13 2012 .DISCUSSION... ISSUED 947 AM CDT WED JUN 13 2012 THUNDERSTORM COMPLEX...ASSOCIATED WITH A SHORTWAVE OVER SOUTH DAKOTA...HAS BEEN WEAKENING AS IT MOVES THROUGH WESTERN IOWA. DRIER AIR OVER ILLINOIS WILL PREVENT THE RAIN FROM MAKING IT AS FAR AS OUR AREA...BUT THICKENING MID AND HIGH CLOUDS FROM THIS SYSTEM HAVE BEGUN MOVING INTO THE WESTERN CWA. LATEST LAYER HUMIDITY PLOTS FROM THE RAP MODEL SHOWING THE THICKEST CLOUDS TO PASS JUST TO OUR NORTH THROUGH MID AFTERNOON...WITH SCATTERED CLOUDS SOUTHWARD OVER MOST OF THE CWA. HAVE SENT OUT SOME ZONE/GRID UPDATES TO INCREASE THE CLOUD COVER SOMEWHAT OVER THE NORTHERN CWA FOR TODAY. CURRENT TEMPERATURE FORECASTS LARGELY ARE ON TRACK AND MADE ONLY VERY MINOR MODIFICATIONS BASED ON OBSERVED TRENDS. GEELHART && .AVIATION... ISSUED 644 AM CDT WED JUN 13 2012...FOR THE 12Z TAFS VFR CONDITIONS WILL CONTINUE OVER THE NEXT 24 HOURS UNDER DRY CANADIAN HIGH PRESSURE. CIRRUS CLOUDS FROM CONVECTIVE DEBRIS OVER THE PLAINS SHOULD BE THE PRIMARY CLOUD COVER OVER THE TERMINALS TODAY. THE LOW AND MID LEVELS WILL REMAIN TOO DRY FOR MUCH IN THE WAY OF FAIR WEATHER CUMULUS. LIKEWISE...VISIBILITY SHOULD REMAIN UNRESTRICTED DUE TO THE VERY LOW SURFACE DEWPOINTS. WINDS WILL CLIMB BETWEEN 10-12KT FROM THE ESE DURING THE DAY...THEN DIMINISH BELOW 10KT BY SUNSET. SHIMON && .PREV DISCUSSION... ISSUED 249 AM CDT WED JUN 13 2012 AT 06Z A BROAD AREA OF 1020 MB HIGH PRESSURE OCCUPIED MUCH OF THE UPPER MIDWEST AND GREAT LAKES. UNDER THIS RIDGE CLEAR SKIES AND LIGHT WINDS ALLOWED EARLY MORNING TEMPERATURES TO DIP INTO THE SEASONABLY COOL 50S LOCALLY. AT THE MID LEVELS ZONAL FLOW DOMINATED MUCH OF THE CENTRAL AND WESTERN U.S. WITH TROUGHING AFFECTING THE EASTERN THIRD OF THE COUNTRY. A SHORTWAVE OVER THE DAKOTAS WAS PRODUCING SOME SHOWERS AS FAR EAST AS WESTERN IOWA. AFTER ANOTHER COMFORTABLE DAY TODAY...WARMING BEGINS THURSDAY THEN 90+ DEGREE HEAT IS EXPECTED FRIDAY THROUGH THE WEEKEND WHEN A MID LEVEL RIDGE STRENGTHENS OVERHEAD. RAIN CHANCES INCREASE FROM THE NW EARLY NEXT WEEK...OR WHEN THE RIDGE FINALLY SHIFTS FARTHER EAST. SHORT TERM...TODAY THROUGH FRIDAY AS THE HIGH SLIPS INTO THE EASTERN GREAT LAKES...EASTERLY LLVL FLOW WILL KEEP TEMPS SIMILAR TO OBSERVED HIGHS YESTERDAY...IN THE UPPER 70S/LOWER 80S. HUMIDITY LEVELS TO REMAIN REMARKABLY LOW FOR MID JUNE WITH DEWPOINTS IN THE 40S. A SHORTWAVE CURRENTLY OVER THE DAKOTAS WILL SHIFT INTO THE FAR UPPER MIDWEST KEEPING ANY PRECIP NORTHWEST OF THE AREA...HOWEVER AN INCREASE IN MID/HIGH LEVEL CLOUDS MAY PREVENT A SECOND COMPLETELY SUNNY DAY AT LEAST ACROSS THE NORTHERN CWA. QUIET WEATHER PREVAILS OVERNIGHT WITH LOWS MODERATING A FEW DEGREES FROM WHAT IS SEEN THIS MORNING. RETURN SOUTHERLY FLOW COMMENCES ON THURSDAY IN CONCERT WITH RISING HEIGHTS WILL PUSH TEMPS BACK UP NEAR SEASONAL NORMALS. BY FRIDAY...LOW TO MID LEVEL THERMAL RIDGE BUILDS OVERHEAD AS A LARGE MID LEVEL HIGH PRESSURE RIDGE STRENGTHENS FROM THE EASTERN GREAT LAKES SOUTHWEST TOWARDS TX. THIS WILL RETURN HIGHS TO THE 90S. DRY SOILS WILL HELP KEEP DEWPOINTS IN CHECK...GRADUALLY RISING THROUGH THE 50S FOR TOLERABLE HUMIDITY LEVELS. LONG TERM...SATURDAY THROUGH TUESDAY PRIMARY WEATHER FEATURES FOR THE EXTENDED PORTION OF THE FORECAST ARE THE EXTENT/DURATION OF HEAT INTO EARLY NEXT WEEK...AND THE POTENTIAL RETURN OF MUCH NEEDED RAINS BY MONDAY/TUESDAY OR LATER. EACH OF THESE ELEMENTS WILL BE DETERMINED BY THE STRENGTH OF THE RIDGE AND HOW QUICKLY IT SHIFTS FAR ENOUGH EAST TO ALLOW AN ACTIVE WX PATTERN TO OUR NORTHWEST TO MOVE IN. FOR NOW WILL KEEP SLIGHT TO LOW CHANCE POPS MONDAY/TUESDAY ACROSS THE NORTHWEST HALF WITH THE ECMWF WEAKENING THE RIDGE QUICKER THAN GFS...WHICH WOULD ALLOW ORGANIZED CONVECTION TO SETTLE SOUTHEAST TOWARDS CENTRAL IL. UNTIL THE RIDGE DAMPENS...HIGHS IN THE LOWER 90S ARE LIKELY. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
614 AM CDT WED JUN 13 2012 .AVIATION...12Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS THROUGH THE PERIOD. SOUTHEAST WINDS AROUND 12 KNOTS DO INCREASE WITH GUSTS UP TO 25 TO 28 KTS BY 15-17Z AND SHOULD CONTINUE UNTIL ABOUT 14/01Z. && .PREV DISCUSSION... 88D MOSAIC THIS MORNING SHOWING NARROW LINE OF BOWED-OUT ELEVATED CONVECTION DRIVING EWD INTO ERN SD/ERN NEB. ACTIVITY WAS OCCURRING WITHIN AREA OF STRONG LAYER DIFFERENTIAL DIVG/850MB WAA WITH A LLVL MOIST FEED UP THRU THE CNTRL PLAINS. HRRR AND RAP SUGGESTING ACTIVITY SHOULD BE OUT OF THE CWA SOMETIME AROUND RUSH HOUR. ON THE WHOLE...MODELS CONTINUE TO BE IN REASONABLY GOOD AGREEMENT THAT LARGE SCALE FLOW OVER THE NEXT WEEK WILL TRANSITION FROM NEAR ZONAL OVER THE CONUS TO A RELATIVELY STAGNANT SITUATION WITH A BROAD TROF COVERING THE WRN CONUS AND A RIDGE TO THE EAST. ALSO GOOD AGREEMENT THAT BULK OF ACCUMULATING PCPN WILL GENERALLY OCCUR OVER THE UPPER MIDWEST...ERN DAKOTAS...WRN IA...ERN NEB THRU DAY 7. ALL THIS IN PART TO A PROLONGED MID LYR BNDRY ORIENTED PARALLEL TO SW-NE FLOW ALOFT WITH SUSTAINED LLVL MOISTURE TO FEED ON PER MOISTURE TRANSPORT PROGS. LIFTING MECHANISM THOUGH WILL BE MEANDERING SOMEWHAT DURING THIS TIME...MAKING IT IMPOSSIBLE TO PIN DOWN POPS WITHIN THE CWA. THUS...BECAUSE OF UNCERTAINTIES WILL OPT TO JUST BLANKET THE AREA WITH SMALL POPS. DEE && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
957 AM EDT WED JUN 13 2012 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE NORTH AND MOVE ACROSS THE AREA THIS EVENING. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO REDEVELOP ACROSS THE EASTERN CAROLINAS THIS AFTERNOON...WITH THE BEST CHANCE ALONG THE COAST. HIGH PRESSURE WILL BUILD IN LATE TONIGHT AND THURSDAY...BRINGING A RELATIVELY COOL AND DRY PATTERN WHICH WILL PERSIST INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM WEDNESDAY...SURFACE WINDS HAVE SHIFTED NORTHWESTERLY ALL THE WAY DOWN TO THE BEACHES THIS MORNING AS A SURFACE TROUGH HAS PUSHED OFF THE COAST. THE ACTUAL SURFACE COLD FRONT IS LAGGING THIS WIND SHIFT AND SHOULD MAKE IT OFFSHORE EARLY THIS EVENING. WE`RE LOSING THE DEEP TROPICAL MOISTURE AS MID-LEVEL WINDS HAVE SHIFTED NORTHWESTERLY BEHIND A DEPARTING UPPER LEVEL TROUGH. PRECIPITABLE WATER VALUES (CURRENTLY 1.75 INCHES) SHOULD FALL THROUGHOUT THE DAY AND INTO TONIGHT AS DRIER AIR BUILDS IN MAINLY AT AND ABOVE 700 MB. WITH MANY MORE BREAKS EXPECTED IN LOW AND MID-LEVEL CLOUD COVER TODAY COMPARED TO THE PAST SEVERAL DAYS HIGH TEMPERATURES SHOULD MAKE IT INTO THE 80S EVERYWHERE...WITH SOME UPPER 80S EVEN POSSIBLE NEAR AND WEST OF LUMBERTON...DILLON AND FLORENCE. THIS WILL STEEPEN LOW-LEVEL LAPSE RATES SIGNIFICANTLY AND SHOULD CREATE SCATTERED SHOWERS AND STORMS THIS AFTERNOON. LATEST HRRR MODEL RUNS SHOW WE SHOULD EXCEED CONVECTIVE TRIGGER TEMPERATURE BETWEEN 17-18Z...1-2 PM EDT. LOWER PRECIP WATER VALUES WILL NOT BE ABLE TO COMPLETELY NEGATE THE THREAT OF MORE HEAVY RAINFALL AND ISOLATED FLOODING DUE TO SLOW CELL MOTION EXPECTED TO BE FROM NORTH TO SOUTH AT ONLY 10-12 MPH. THERE WILL ALSO BE A THREAT OF GUSTY WINDS AS DRIER AIR ALOFT IS ENTRAINED INTO THE STORM CELLS WITH DCAPE VALUES INCREASING TO 1000 J/KG OR MORE. CONVECTIVE ACTIVITY SHOULD END FROM NORTH TO SOUTH THIS EVENING AS THE ACTUAL COLD FRONT PUSHES OFFSHORE AND DRIER MORE STABLE AIR BUILDS IN. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE TEMPERATURES AS MOISTURE WILL BE ON THE DECREASE AS AN OMEGA CONFIGURATION DEVELOPS AT THE MID LEVELS. AT THE SURFACE A FORMIDABLE NORTHEAST FLOW WILL DEVELOP AS HIGH PRESSURE BUILDS DOWN FROM THE NORTHEAST AND LOW PRESSURE MEANDERS NEAR BERMUDA. MET GUIDANCE IS QUITE A BIT WARMER AS OPPOSED TO THE MAV NUMBERS THROUGH THE PERIOD MORE-SO THURSDAY. THIS APPEARS TO BE A FUNCTION OF LINGERING LOW LEVEL MOISTURE VIA THE GFS. NUMBERS JOG TOWARD SLIGHTLY BETTER AGREEMENT FRIDAY. HAVE LEANED TOWARD THE COOLER MAV NUMBERS OPTING FOR A SLOWER PROGRESSION OF THE LOW LEVEL MOISTURE. NO POPS THROUGH THE PERIOD. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...NO SIGNIFICANT CHANGES TO THE MEDIUM RANGE GUIDANCE THIS MORNING AS THE FORECAST AREA CONTINUES TO BE SITUATED IN THE EASTERN PART OF A MID LEVEL OMEGA PATTERN FOR MOST OF THE PERIOD. I DID INCREASE THE POPS INCREMENTALLY SUNDAY AND MONDAY TO SLIGHT CHANCE TO MATCH HPC AND ADJACENT OFFICES VIA NORTHEAST RESULTANT SEA BREEZE COMBINED WITH THE 700MB SUBSIDENCE INVERSION ABATING. THE PATTERN BEGINS TO CHANGE LATE IN THE PERIOD WITH THE GFS ADVERTISING A REX BLOCK DEVELOPING SO CONFIDENCE IS BELOW AVERAGE. NO CHANGES TO TEMPERATURE FORECAST. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...MOST OF THE SIGNIFICANT CONVECTION IS OFFSHORE... ASSOCIATED WITH A PRE-FRONTAL TROUGH. LOOK FOR LIGHT SHOWERS TO AFFECT THE COASTAL TERMINALS FOR THE FIRST HOUR OR SO...ALONG WITH INTERMITTENT STRATUS. LOW LEVELS BEGIN TO DRY OUT BY 13Z AS THE WINDS SHIFT MORE TO THE NORTH AS THE COLD FRONT BEGINS TO PUSH THROUGH. WILL HAVE TO WATCH THE STRATUS...CURRENT THINKING IS WE WILL SEE A QUICK TRANSITION TO VFR BY MID MORNING...CONFIDENCE MODERATE. SHOULD SEE PRETTY FULL SUN BY NOON TODAY. THERE COULD BE ENOUGH HEATING TO KICK OFF SCATTERED LIGHT SHOWERS MAINLY ALONG THE COAST THIS AFTERNOON. COVERAGE SHOULD BE LIMITED. TONIGHT...VFR CONDITIONS WITH LIGHT NORTHEASTERLY WINDS. EXTENDED OUTLOOK...MAINLY VFR THROUGH THE FORECAST PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 AM WEDNESDAY...THUNDERSTORM ACTIVITY HAS PUSHED WELL OFFSHORE AND INTO THE GULF STREAM...WITH LIGHTER SHOWERS NOW ENDING ACROSS THE COASTAL WATERS. THERE SHOULD BE A LULL IN CONVECTION LASTING THROUGH EARLY AFTERNOON BEFORE ADDITIONAL SHOWERS AND THUNDERSTORMS DEVELOPING INLAND BEGIN TO MOVE OFFSHORE...AFFECTING THE COASTAL WATERS THROUGH THIS EVENING. WINDS HAVE SHIFTED TO THE WEST OR NORTHWEST THIS MORNING AS A TROUGH HAS PUSHED OFF THE COAST. THE ACTUAL SURFACE COLD FRONT IS STILL WELL INLAND AND SHOULD WAIT UNTIL THIS EVENING TO PUSH OFF THE COAST. SEAS CURRENTLY RANGE FROM 2-3 FT NEAR THE COAST...BUT EARLIER SHOWER/STORM ACTIVITY HAS BUILT SEAS TO AROUND 5 FT AT THE FRYING PAN SHOALS BUOY AND AT THE OFFSHORE LEJEUNE BUOY. SEA HEIGHTS SHOULD DIMINISH THROUGH EARLY EVENING...BUT MAY BEGIN TO BUILD LATER TONIGHT AS INCREASING NORTHEAST WINDS DEVELOP BEHIND THE ACTUAL COLD FRONT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...A NORTHEASTERLY FLOW WILL PREVAIL THROUGHOUT THE PERIOD AS HIGH PRESSURE BUILDS DOWN FROM THE NORTHEAST AND LOW PRESSURE SLOWLY DEVELOPS WELL INTO THE ATLANTIC. STRONGEST WINDS OCCUR LATE FRIDAY WHEN THE 20-25 KNOT RANGE WILL LIKELY BE CLOSER TO THE HIGH END OF THE RANGE. THE PERSISTENT FETCH WILL ALLOW SEAS TO BUILD LATE THURSDAY TO ECLIPSE THE SIX FOOT SMALL CRAFT CRITERIA AND CONTINUE THROUGH THE REMAINDER OF THE PERIOD. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...ESSENTIALLY NO CHANGES TO THE EXTENDED COASTAL WATERS FORECAST AS A NORTHEASTERLY FLOW SHOULD PREVAIL. MAY SEE MORE VEERING SUNDAY AFTERNOON AS THE FLOW IS LIGHTER ALLOWING MORE OF A NORTHEAST RESULTANT TO DEVELOP. THE CAVEAT WITH THIS TYPE OF SCENARIO ARE THE EMBEDDED SURGES. I DID WALK BACK SEAS SLIGHTLY BUT A SMALL CRAFT ADVISORY MAY STILL BE NEEDED BUT IT APPEARS MORE MARGINAL AT THIS POINT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...SHK LONG TERM...SHK AVIATION...DL
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
634 AM CDT WED JUN 13 2012 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT 325 AM CDT WED JUN 13 2012 MAIN FORECAST CONCERN DEALS WITH RAIN CHANCES TODAY THROUGH FRIDAY NIGHT. WATER VAPOR IMAGERY AND RAP ANALYSIS AT 2 AM SHOWS A DISTINCT MID-LEVEL CYCLONIC CIRCULATION MOVING EAST ACROSS CENTRAL SD. MOISTURE TRANSPORT AND ISENTROPIC LIFT AHEAD OF THE WAVE AIDING IN SHOWERS AND ISOLATED THUNDERSTORMS ACROSS EASTERN SD/NEB...INTO NORTHWEST IA. CLOSER TO HOME OVER OUR FORECAST AREA...HIGH CLOUDS FROM THE DAKOTAS WAVE STREAMING IN WITH CENTER OF HIGH PRESSURE ACROSS CENTRAL WI INTO CENTRAL LOWER MI. LIGHT WINDS AND PARTLY CLOUDY CONDITIONS HAS ALLOWED TEMPERATURES TO DIP TO 37 DEGREES AT BLACK RIVER FALLS WI...WHILE OTHER LOCATIONS RANGED FROM THE 40S TO THE LOWER 50S UNDER MORE CLOUD COVER. 13.00Z NCEP MODEL SUITE/ECMWF/GEM GENERALLY IN GOOD AGREEMENT THROUGH THE SHORT TERM PERIOD. FOR TODAY...WILL BE WATCHING THAT MID-LEVEL WAVE OVER SD MOVES INTO CENTRAL MN THROUGH THIS AFTERNOON. MODELS CONCENTRATE MAIN AXIS OF ASSOCIATED 850MB MOISTURE TRANSPORT NORTHWEST INTO MN WITH OUR AREA JUST ON THE EASTERN FRINGES. MEANWHILE...DECENT AMOUNT OF ISENTROPIC LIFT INTO THE AREA FOR MID-CLOUD/ACCAS GENERATION. KEPT SMALL CHANCES OF SHOWERS MAINLY NORTHWEST OF A LINE FROM MEDFORD AND ARCADIA WI...TO ROCHESTER AND AUSTIN MN. OTHERWISE...WITH INCREASING CLOUD COVER EXPECTED...HIGHS TODAY ARE EXPECTED TO TOP OFF IN THE LOWER TO MIDDLE 70S. TONIGHT...ANOTHER MID-LEVEL WAVE AND SURFACE CYCLOGENESIS WILL TAKE PLACE OVER NEB/SD WITH MOISTURE TRANSPORT/ISENTROPIC LIFT IMPINGING ON THE WESTERN PORTIONS OF THE FORECAST AREA. PLANNING ON ISOLATED SHOWER AND ISOLATED THUNDER //WITH INCREASING ELEVATED MUCAPE// NORTHWEST OF A MEDFORD-ARCADIA-ROCHESTER-AUSTIN LINE AGAIN IN THE EVENING...THEN INCREASING SLIGHTLY IN COVERAGE/SPREADING EAST INTO THE REST OF THE AREA AFTER MIDNIGHT AS 850MB MOISTURE TRANSPORT VECTORS BEND MORE INTO THE AREA. RAINFALL LOOKS VERY LIGHT WITH GENERALLY LESS THAN 5 HUNDRETHS OF AN INCH EXPECTED. ON THURSDAY...LOOK FOR THE MID-LEVEL WAVE/SURFACE COLD FRONT TO MOVE INTO MN WITH INCREASING 850MB MOISTURE TRANSPORT INTO THE AREA. 0-3KM MLCAPE INCREASES INTO THE 1000-1500J/KG RANGE ALONG AND AHEAD OF THE FRONT JUST TO OUR WEST WITH RESPECTABLE 20-30KT 0-3KM BULK SHEAR. THEREFORE...EXPECTING STRONGER THUNDERSTORM ACTIVITY ALONG THE FRONT BY AFTERNOON WITH EASTERN FRINGES OF THIS ACTIVITY PERHAPS MAKING IT INTO NORTHWEST PORTIONS OF THE FORECAST AREA. FOR NOW...WILL STICK WITH 20-40 PERCENT SHOWER/THUNDERSTORM CHANCE NORTHWEST OF A SPARTA-VIROQUA-OELWEIN LINE. OTHERWISE...LOOK FOR HIGH TEMPERATURES IN THE UPPER 70S TO LOWER 80S. FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT...LOOK FOR THE COLD FRONT OVER MN TO SINK INTO THE AREA WHILE WEAKENING. MEANWHILE...MODELS SHOWING A COUPLE MID-LEVELS WAVE EJECTING NORTHEAST TOWARD/ACROSS THE AREA WITH BOUTS OF LIFT/MOISTURE TRANSPORT. BASED ON THIS SIGNAL...WILL GO WITH 30-50 SHOWER/THUNDERSTORM CHANCES FOR NOW FOR THIS PERIOD. .LONG TERM...SATURDAY THROUGH TUESDAY 325 AM CDT WED JUN 13 2012 13.00Z GFS/ECMWF SHOWING SOUTHWEST FLOW ALOFT INTO THE AREA THROUGH THE PERIOD AS HIGH PRESSURE ANCHORS IN ACROSS THE EASTERN CONUS AND A TROUGH SLOWLY MAKES ITS WAY ACROSS THE INTERMOUNTAIN WEST INTO THE PLAINS. SIGNAL AGREEMENT BETWEEN THE MODELS SEEMS TO BE GETTING STRONGER FOR PERIODIC SHOWER/THUNDERSTORM CHANCES THROUGH THE WEEKEND. BOTH MODELS THEN BRING IN A DEEPER TROUGH/STRONGER SURFACE COLD FRONT INTO THE AREA MONDAY THROUGH TUESDAY FOR CONTINUED SHOWER/THUNDERSTORM CHANCES. && .AVIATION...TODAY AND TONIGHT 634 AM CDT WED JUN 13 2012 A SOUTH-SOUTHEAST FLOW WILL HELP HOLD DRY AIR IN PLACE IN THE LOWER LEVELS OF THE ATMOSHPERE...RESULTING IN CONDITIONS REMAINING VFR THROUGH TONIGHT. THIS FLOW ORIGINATES OUT OF HIGH PRESSURE MOVING EAST INTO THE GREAT LAKES. ABOVE THIS DRY AIR...MOISTURE WILL RETURN FROM THE GULF OF MEXICO AHEAD OF A LOW PRESSURE SYSTEM IN THE DAKOTAS. A FEW SHOWERS AND PERHAPS EVEN THUNDERSTORMS COULD IMPACT THE KRST TAF SITE AFTER MIDNIGHT...ON THE NOSE OF THIS MOISTURE RETURN. HOWEVER...CONFIDENCE IS ONLY HIGH ENOUGH TO PUT A VCSH IN AFTER 06Z. OTHER SHOWERS CURRENTLY PRESENT ON RADAR AROUND THE SIOUX FALLS AREA ARE EXPECTED TO WEAKEN AND HEAD OFF TO THE NORTHWEST...STAYING MOSTLY AWAY FROM KRST AND KLSE. REGARDING THE SOUTH-SOUTHEAST FLOW...THE WINDS SHOULD BECOME GUSTY AT KRST WITH GUSTS TO 20 KT DUE TO DAYTIME HEATING AND A TIGHTER PRESSURE GRADIENT THAN AT KLSE. THESE GUSTS WILL END THIS EVENING WITH LOSS OF HEATING. && .ARX WATCHES/WARNINGS/ADVISORIES... 325 AM CDT WED JUN 13 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
333 PM EDT WED JUN 13 2012 .SYNOPSIS... LOW PRESSURE TO OUR EAST WILL CONTINUE TO PULL FURTHER OFFSHORE TONIGHT WHILE HIGH PRESSURE NOSES IN FROM THE NORTHWEST. THIS RIDGE WILL REMAIN COMPLACENT OVER THE REGION THURSDAY THROUGH WEDNESDAY OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... THE WRF-NMMB LOOKED BETTER THAN THE GFS WITH ITS 500MB INITIALIZATION IN THE NERN CONUS, THE GFS LOOKED BETTER IN OTHER PLACES EAST. ALSO THE GFS LOOKED SLIGHTLY BETTER AT 850MB AND 925MB. IN TERMS OF VERIFYING "WHAT IS OUT THERE", THE GFS AND CAN RGEM LOOKED SLIGHTLY BETTER THAN THE WRF-NMMB. SO THE PLAN IS TO LEAN TOWARD THE GFS THROUGH THE SHORT TERM AND MOVE THE CHANCES FASTER THROUGH OUR CWA TONIGHT. THE HRRR WAS NOT USED AS ITS WAVES OF SHOWERS REACHING INTO PA IS AND HAS NOT BEEN VERIFYING. SHOWERS CHANCES ARE TIED TO A COMBINATION OF THE GFS, CAN RGEM AND 4KM ARW SOLUTIONS. NOT MUCH DPVA FORECAST BEYOND MIDNIGHT AND NO OTHER FORCING APPARENT. SOME COASTAL FRICTIONAL CONVERGENCE HELPING NOW ALONG THE INVERTED TROF. AS THE OFFSHORE LOW SAGS SOUTH, SO SHOULD THE GREATER CONVERGENCE/SFC TROF AND HENCE THE SOUTHWARD SAG OF POPS. OTHERWISE EXPERIMENTAL SATELLITE IMAGERY IS SHOWING A FAIRLY LARGE SWATH OF MVFR WITH LOW PROBABILITY IFR CIGS OFFSHORE. AS THE SFC LOW SAGS SOUTHWARD, THE WINDS WILL VEER MORE TOWARD THE ONSHORE DIRECTION. WITH THE FORECAST SOUNDINGS DEVELOPING AN INVERSION, THIS SHOULD TRAP THE CLOUDS AND HELP SPREAD IT WESTWARD INTO OUR CWA. RIGHT NOW WE ARE LEANING MORE TOWARD CLOUDINESS THAN FOG. WE ARE MAKING SKY COVER MORE PESSIMISTIC TONIGHT. CONFIDENCE AS TO HOW FAR WEST THIS GETS IS NOT HIGH. BECAUSE WE ARE GOING WITH THE CLOUDIER FORECAST, WE ARE ALSO GOING WITH HIGHER STAT GUIDANCE MINIMUM TEMPERATURES. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... ONCE THE STRATOCU CEILING IN OUR CWA GETS ESTABLISHED, THE CONTINUING ONSHORE FLOW MAY HELP TAKE IT A WHILE LONGER THAN TYPICALLY FOR JUNE FOR SUNSHINE TO DEVELOP ON THURSDAY. WE HAVE GONE THE CONSERVATIVE ROUTE WITH THE SUNSHINE. ONE KNOWN WEAKNESS OF THE NEW VERSION OF THE GFS IS EVEN A MORE GENEROUS WET BIAS WITH THE .01 ISOHYET. AT THE RISK OF PUTTING OUR FOOT IN OUR MOUTHS, THAT IS WHAT THE GFS LOOKS LIKE ITS DOING IN OUR CWA TOMORROW. ITS GETTING THERE BY POOLING DEW POINTS INTO THE MID 60S AND GENERATING SOME WEAK CAPE. ITS OWN STAT GUIDANCE HAS DEW POINTS 5 TO 8F LOWER AND WITHOUT THOSE DEW POINTS, THE CHANCES GET THAT MUCH LOWER. EVEN WITH FULL SUN AND OFF THE FORECAST 925MB TEMPERATURES, GFS MOS MAX TEMPS LOOK TOO WARM. MAX TEMPS CLOSER TO NAM MOS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... 5-WAVE MODEL GUIDANCE SHOWS BLOCKING TO OUR NORTHEAST WHERE A LONGWAVE TROUGH HAS RESIDED FOR THE PAST COUPLE OF DAYS. RIDGING WILL MOVE INTO THE REGION BY FRIDAY ORIENTED SOUTHWEST TO NORTHEAST. THIS WILL PROVIDE A STAGNANT PATTERN THROUGH MID-WEEK NEXT WEEK. IT WILL PROVIDE DRY CONDITIONS WITH SLIGHTLY BELOW NORMAL TEMPERATURES TO START THE PERIOD. WITH THE STAGNANT PATTERN CONFIDENCE IN THE LONGTERM FORECAST IS HIGH. AS THE MID-LEVEL AND SURFACE RIDGING MOVE EVER SO SLIGHTLY TO OUR EAST ON SUNDAY AND MONDAY OUR SURFACE FLOW WILL TURN MORE TOWARDS THE SOUTH-SOUTHEAST. THIS WILL ALLOW THICKNESSES TO INCREASE AS WARMER, MOISTER AIR IS ADVECTED INTO OUR REGION. TEMPERATURES WILL BEGIN A SLOW UPWARD TREND STARTING ON MONDAY THROUGH THE REMAINDER OF THE PERIOD. WITH THE NORTHEASTERLY FLOW TURNING MORE EASTERLY BY SATURDAY WE WILL SEE DIURNALLY DRIVEN CLOUDS AT NIGHT THROUGH WEDNESDAY...BETTER CHANCES CLOSER TO THE COAST. DURING THE OVERNIGHT HOURS WE WILL SEE MOISTURE POOLING IN THE LOW-LEVELS WHICH COULD PRODUCE PROLONGED PERIODS OF FOG AND OVERCAST CONDITIONS...MOST OF THE LOWER CLOUDS AND FOG WILL BURN OFF DURING THE MORNING HOURS. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A TRENDING TOWARD MVFR TAF PACKAGE WAS ISSUED WITH THE 18Z TAFS, ALTHOUGH CONFIDENCE IS LOWER THAN AVERAGE. THE EASTWARD ADVANCE OF THE LOWER CLOUDS HAS HIT THE WALL AND THEY ARE SLOWLY ADVANCING TO THE WEST. SOME SHOWERS ARE EXPECTED TO REMAIN JUST EAST OF KACY. WE EXPECT THE EASTERN NJ AIRPORTS AND KACY TAF SITE TO REMAIN MVFR WITH SOME WESTWARD PROGRESSION IN NJ. THE PA AND DELMARVA AIRPORTS SHOULD REMAIN VFR WITH SOME CUMULUS AND CIRRUS CLOUDS. GUSTY NORTH WINDS (20 TO 25 KT GUSTS) SHOULD CONTINUE THROUGH THE AFTERNOON WITH A SLOW VEERING TO THE NORTHEAST. FOR THIS EVENING WE ARE EXPECTING THE MVFR CIGS TO ADVANCE WESTWARD EVEN MORE AS IT PROGRESSES. GREATEST CONFIDENCE OF MVFR CONDITIONS EASTERN TERMINALS, LESS CONFIDENCE ABOUT IT REACHING KABE AND KRDG. THE WESTERN EDGE OF SHOWERS WILL CONTINUE TO BE NEAR KACY AND KMIV. NOT ENOUGH CONFIDENCE TO INCLUDE. FORECAST SOUNDINGS SUGGESTING SOME GUSTINESS MAY CONTINUE INTO THE EVENING, ESPECIALLY EASTERN TERMINALS. WE BELIEVE THERE WILL BE EITHER TOO MANY CLOUDS OR WINDS FOR FOG TO FORM OVERNIGHT. ONCE THE MVFR CIG ARRIVES, IT MAY TAKE A WHILE FOR IT TO DISSIPATE ON THURSDAY. SO OTHER THAN OUR NW TERMINALS, WE KEPT MVFR CIGS GOING THROUGH THE MORNING. SOME GUSTINESS FROM THE NORTHEAST (SLIGHTLY LOWER THAN TODAY) WINDS SHOULD RETURN IN THE MORNING. THE OVERALL GRADIENT IS EXPECTED TO RELAX DURING THURSDAY AFTERNOON WHICH MIGHT BE A WINDOW TO HAVE CLOUDS DISSIPATE OR RISE TO VFR CIGS. OUTLOOK... THU NIGHT - WEDNESDAY... VFR CONDITIONS WITH EAST-NORTHEAST WINDS. POSSIBLE LOCAL MVFR CONDITIONS DURING THE OVERNIGHT AND EARLY MORNING HOURS...MAINLY EAST OF PHILADELPHIA. && .MARINE... WE WILL EXTEND THE SCA ON DELAWARE BAY THROUGH THE NIGHT. FORECAST SOUNDINGS ARE NOW SHOWING SMALL CRAFT ADVISORY WINDS NEAR THE TOP OF THE MIXING LEVEL THROUGH THE NIGHT. IT IS PROBABLE THAT WE WILL GO BELOW SMALL CRAFT ADVISORY LEVEL GUSTS FROM TIME TO TIME THE REST OF THIS AFTERNOON AND EVENING, BUT AS AIR TEMPERATURES EDGE BELOW THE WATER TEMPERATURES OVERNIGHT, THERE MAY BE ANOTHER WINDOW FOR MORE FREQUENT SCA LEVEL GUSTS. THE OVERALL GRADIENT IS EXPECTED TO BE LESSEN ON THURSDAY, SO THE CHANCES FOR SCA CRITERIA WILL DECREASE AS THE DAY PROGRESSES ON THE BAY. ON THE OCEAN, SMALL CRAFT ADVISORY LEVEL WINDS SHOULD OCCUR TONIGHT AND THEN INTO THURSDAY ON THE SOUTHERN WATERS. SWELLS WILL BE A CONTINUING AND LAGGING ISSUE ONCE THE WINDS CEASE AS THE OVERALL ONSHORE FLOW SHOULD PERSIST FOR A WHILE. WE DID NOT EXTEND THE SCA ON THE OCEAN FOR EITHER SEGMENTS, BUT SOME ADJUSTMENTS MAY BECOME NECESSARY AS CONFIDENCE INCREASES. OUTLOOK... HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST AND SLIDE TO OUR NORTHEAST BY SATURDAY. THIS WILL PROVIDE DRY WEATHER ALTHOUGH WITH AN ONSHORE FLOW WE COULD STILL HAVE SOME LINGERING ISSUES WITH SWELLS ACROSS OUR SOUTHERN WATERS THROUGH SATURDAY. AFTER THAT SEAS WILL BECOME MORE TRANQUIL AS WE LOSS THE SWELLS. && .RIP CURRENTS... THE COMBINATION OF LARGE...8 SECOND PERIOD SWELLS AND FAIRLY HIGH SURF ZONE WAVES WILL INTERACT TO CREATE A HIGH RISK OF RIP CURRENTS FOR BOTH THE NEW JERSEY AND DELAWARE COASTS FOR THURSDAY. DUE TO THE HIGH RISK...A HIGH RIP CURRENT RISK HEADLINE WILL BE ISSUED FOR THURSDAY. THE DETAILS OF THE HIGH RIP CURRENT RISK CAN BE FOUND IN THE COASTAL HAZARD MESSAGE PRODUCT /AWIPS HEADER PHLCFWPHI/. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...HIGH RIP CURRENT RISK FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR NJZ014-024>026. DE...HIGH RIP CURRENT RISK FROM THURSDAY MORNING THROUGH THURSDAY EVENING FOR DEZ004. MD...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THURSDAY FOR ANZ452>455. SMALL CRAFT ADVISORY UNTIL 7 AM EDT THURSDAY FOR ANZ430-431- 450-451. && $$ SYNOPSIS...HEAVENER NEAR TERM...GIGI SHORT TERM...GIGI LONG TERM...HEAVENER AVIATION...GIGI/HEAVENER MARINE...GIGI/HEAVENER RIP CURRENTS...HAYES
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1208 PM CDT WED JUN 13 2012 .DISCUSSION... ISSUED 947 AM CDT WED JUN 13 2012 THUNDERSTORM COMPLEX...ASSOCIATED WITH A SHORTWAVE OVER SOUTH DAKOTA...HAS BEEN WEAKENING AS IT MOVES THROUGH WESTERN IOWA. DRIER AIR OVER ILLINOIS WILL PREVENT THE RAIN FROM MAKING IT AS FAR AS OUR AREA...BUT THICKENING MID AND HIGH CLOUDS FROM THIS SYSTEM HAVE BEGUN MOVING INTO THE WESTERN CWA. LATEST LAYER HUMIDITY PLOTS FROM THE RAP MODEL SHOWING THE THICKEST CLOUDS TO PASS JUST TO OUR NORTH THROUGH MID AFTERNOON...WITH SCATTERED CLOUDS SOUTHWARD OVER MOST OF THE CWA. HAVE SENT OUT SOME ZONE/GRID UPDATES TO INCREASE THE CLOUD COVER SOMEWHAT OVER THE NORTHERN CWA FOR TODAY. CURRENT TEMPERATURE FORECASTS LARGELY ARE ON TRACK AND MADE ONLY VERY MINOR MODIFICATIONS BASED ON OBSERVED TRENDS. GEELHART && .AVIATION... ISSUED 1207 PM CDT WED JUN 13 2012 EASTERLY WINDS WILL PERSIST THROUGH ABOUT 06Z...BEFORE TRENDING SOUTHEAST AS A COLD FRONT BEGINS TO PUSH THROUGH THE CENTRAL PLAINS. SOME INCREASE IN SPEED IS EXPECTED TOWARD THE END OF THE PERIOD AS THE FRONT GETS CLOSER. EXPECT PERIODIC CLOUD COVER TO REMAIN AT OR ABOVE 12 KFT DUE TO DRY AIR IN THE LOWER LEVELS OF THE ATMOSPHERE. GEELHART && .PREV DISCUSSION... ISSUED 249 AM CDT WED JUN 13 2012 AT 06Z A BROAD AREA OF 1020 MB HIGH PRESSURE OCCUPIED MUCH OF THE UPPER MIDWEST AND GREAT LAKES. UNDER THIS RIDGE CLEAR SKIES AND LIGHT WINDS ALLOWED EARLY MORNING TEMPERATURES TO DIP INTO THE SEASONABLY COOL 50S LOCALLY. AT THE MID LEVELS ZONAL FLOW DOMINATED MUCH OF THE CENTRAL AND WESTERN U.S. WITH TROUGHING AFFECTING THE EASTERN THIRD OF THE COUNTRY. A SHORTWAVE OVER THE DAKOTAS WAS PRODUCING SOME SHOWERS AS FAR EAST AS WESTERN IOWA. AFTER ANOTHER COMFORTABLE DAY TODAY...WARMING BEGINS THURSDAY THEN 90+ DEGREE HEAT IS EXPECTED FRIDAY THROUGH THE WEEKEND WHEN A MID LEVEL RIDGE STRENGTHENS OVERHEAD. RAIN CHANCES INCREASE FROM THE NW EARLY NEXT WEEK...OR WHEN THE RIDGE FINALLY SHIFTS FARTHER EAST. SHORT TERM...TODAY THROUGH FRIDAY AS THE HIGH SLIPS INTO THE EASTERN GREAT LAKES...EASTERLY LLVL FLOW WILL KEEP TEMPS SIMILAR TO OBSERVED HIGHS YESTERDAY...IN THE UPPER 70S/LOWER 80S. HUMIDITY LEVELS TO REMAIN REMARKABLY LOW FOR MID JUNE WITH DEWPOINTS IN THE 40S. A SHORTWAVE CURRENTLY OVER THE DAKOTAS WILL SHIFT INTO THE FAR UPPER MIDWEST KEEPING ANY PRECIP NORTHWEST OF THE AREA...HOWEVER AN INCREASE IN MID/HIGH LEVEL CLOUDS MAY PREVENT A SECOND COMPLETELY SUNNY DAY AT LEAST ACROSS THE NORTHERN CWA. QUIET WEATHER PREVAILS OVERNIGHT WITH LOWS MODERATING A FEW DEGREES FROM WHAT IS SEEN THIS MORNING. RETURN SOUTHERLY FLOW COMMENCES ON THURSDAY IN CONCERT WITH RISING HEIGHTS WILL PUSH TEMPS BACK UP NEAR SEASONAL NORMALS. BY FRIDAY...LOW TO MID LEVEL THERMAL RIDGE BUILDS OVERHEAD AS A LARGE MID LEVEL HIGH PRESSURE RIDGE STRENGTHENS FROM THE EASTERN GREAT LAKES SOUTHWEST TOWARDS TX. THIS WILL RETURN HIGHS TO THE 90S. DRY SOILS WILL HELP KEEP DEWPOINTS IN CHECK...GRADUALLY RISING THROUGH THE 50S FOR TOLERABLE HUMIDITY LEVELS. LONG TERM...SATURDAY THROUGH TUESDAY PRIMARY WEATHER FEATURES FOR THE EXTENDED PORTION OF THE FORECAST ARE THE EXTENT/DURATION OF HEAT INTO EARLY NEXT WEEK...AND THE POTENTIAL RETURN OF MUCH NEEDED RAINS BY MONDAY/TUESDAY OR LATER. EACH OF THESE ELEMENTS WILL BE DETERMINED BY THE STRENGTH OF THE RIDGE AND HOW QUICKLY IT SHIFTS FAR ENOUGH EAST TO ALLOW AN ACTIVE WX PATTERN TO OUR NORTHWEST TO MOVE IN. FOR NOW WILL KEEP SLIGHT TO LOW CHANCE POPS MONDAY/TUESDAY ACROSS THE NORTHWEST HALF WITH THE ECMWF WEAKENING THE RIDGE QUICKER THAN GFS...WHICH WOULD ALLOW ORGANIZED CONVECTION TO SETTLE SOUTHEAST TOWARDS CENTRAL IL. UNTIL THE RIDGE DAMPENS...HIGHS IN THE LOWER 90S ARE LIKELY. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
351 PM CDT WED JUN 13 2012 .SYNOPSIS... ISSUED AT 342 PM CDT WED JUN 13 2012 A BROAD WEAK, ZONAL MID LEVEL FLOW PATTERN WA IN PLACE ACROSS WESTERN KANSAS. INCREASING BOUNDARY LAYER MOISTURE WAS OCCURRING AS SOUTHERLY WINDS TRANSPORTED HIGHER CONTENT MOISTURE AIR FROM WESTERN OKLAHOMA AND THE PANHANDLES. FARTHER WEST, A DRYLINE WAS EVIDENT IN THE MESONET POINT DATA ACROSS SOUTHEAST COLORADO, AS WELL AS IN A FINE LINE DEVELOPING ON KPUX RADAR FROM LAMAR, CO SOUTHWEST. && .SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 342 PM CDT WED JUN 13 2012 THE SHORT TERM MODELS HANDLE THE EVOLUTION OF CONVECTION THIS EVENING VERY DIFFERENTLY AND THERE IS RELATIVELY LOW CONFIDENCE IN THIS NEAR TERM FORECAST. THE 12UTC NAM MODEL WOULD INDICATE AND STORMS THAT DEVELOP REMAIN ANCHORED TO THE MUCH HIGHER CAPE/INSTABILITY AXIS OF THE HIGH PLAINS OF COLORADO INTO THE WEST TEXAS PANHANDLE THIS EVENING. AT HIS TIME, THIS NAM SOLUTION SEEMS TO BE MORE LIKELY THAN OTHERS BASED ON THE WEAK FORCING ENVIRONMENT WE ARE DEALING WITH. HOWEVER, WE CANNOT COMPLETELY IGNORE THE RECENT ARW-WRF/NMM RUNS AND HRRR THAT HAVE ELUDED TO CONVECTION OVER EASTERN COLORADO LATER THIS AFTERNOON DEVELOPING A COLD POOL AND SPREADING RAPIDLY INTO THE WESTERN SEVERAL TIERS OF COUNTIES IN THE EVENING HOURS. IF THAT DOES OCCUR, THE MOST PLAUSIBLE OUTCOME WOULD SEEM TO BE MARGINALLY ISOLATED SEVERE THUNDERSTORM WIND GUSTS AND PERHAPS ISOLATED HAIL PUSHING SEVERE LIMITS OF AN INCH AT MOST. HOWEVER, THE WEAKER CONVECTION COULD SPREAD FOR SEVERAL HOURS EASTWARD INTO CENTRAL KANSAS DURING THE LATE EVENING. CONVECTIVE CHANCES ARE JUST AS GOOD OR BETTER ALONG A STRENGTHENING COLD FRONTAL BOUNDARY WHICH SHOULD UNDERGO FRONTOGENESIS FROM WEST CENTRAL KANSAS INTO NORTH CENTRAL KANSAS DURING THE VERY LATE AFTERNOON INTO THURSDAY EVENING. THIS WILL BE BE WEAK FORCING, BUT PERHAPS MORE MODERATE CAPE VALUES BY LATE IN THE DAY. ISOLATED SEVERE CONVECTION COULD BE FOUND THROUGH THE INTERSTATE 70 CORRIDOR, WESTWARD TO SCOTT CITY LATE IN THE AFTERNOON THURSDAY, BUT WIDESPREAD SEVERE IS NOT ANTICIPATED. THE NAM MODEL IS INDICATING THE WARMEST TEMPERATURES AROUND 100 DEGREES, WHILST MOST OTHER NUMERICAL OUTPUT IS INDICATING LOW 90S. TEMPERATURES SHOULD WARM TO SOMEWHERE IN THE MIDDLE THURSDAY AFTERNOON ACROSS SOUTHWEST AND CENTRAL KANSAS. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 302 PM CDT WED JUN 13 2012 THE EXTENDED PERIOD BEGINNING FRIDAY WILL SEE ONE UPPER SHORT WAVE EXITING THE WESTERN PLAINS OF KANSAS, BRINGING ABOUT A 40 TO 50 PERCENT CHANCE OF THUNDERSTORMS NEAR THE I-70 CORRIDOR AND NORTHWARD, EARLY THURSDAY NIGHT. AFTER MIDNIGHT THURSDAY, THE PRECIP CHANCES WILL CHANGE TO 30 TO 40 PERCENT, AND ONLY IN TREGO, ELLIS AND RUSH COUNTIES. THE NAM MODEL IS HINTING AT QPF FROM 0.60 TO 0.80-INCH IN OUR NORTHWEST FROM HAYS TO SCOTT CITY, BUT HAVE A HARD TIME BUYING THAT MUCH PERCEPTIBLE WATER WILL FALL OUT, BASED ON RECENT TRENDS. TRIMMED THURSDAY NIGHT QPF TO AROUND 0.25 TO 0.30-INCH. AS THAT SHORT WAVE EXITS, ANOTHER SMALL SCALE WAVE IS EJECTED FROM THE LARGE UPPER LOW OFF THE COAST OF BAJA CALIFORNIA. THIS SECOND WAVE IS LESS ORGANIZED THAN THE FIRST, AND WILL BRING THUNDERSTORM CHANCES TO THAT AREA NORTH OF A LINE FROM JOHNSON CITY TO LA CROSSE. THE UPPER BAJA LOW CUTS OFF SATURDAY NIGHT PER THE ECMWF AND GFS MODELS, AND AN UPPER HIGH BEGINS TO BUILD OVER TEXAS. FOR NOW, PLAN TO KEEP SUNDAY AND SUNDAY NIGHT FREE OF PRECIPITATION CHANCES, BUT OUR EXTREME EAST WILL HAVE A SLIGHT CHANCE MONDAY AFTERNOON AS UPPER DIVERGENCE WILL BE OVERHEAD, AND A DOWN SLOPE FLOW WILL BE EVOLVING. A COLD FRONT WILL SINK INTO SOUTHWEST KANSAS MONDAY NIGHT, AND THERE COULD BE A FEW SCATTERED STORMS IN OUR SOUTHEAST ZONES WHERE THE GREATEST MOISTURE WILL BE, SUCH AS SOUTHEAST OF LINE FORM LARNED TO DODGE CITY TO ASHLAND MONDAY NIGHT. THE CR-EXTENDED BLEND PROCEDURE PLACED 30 POPS IN MY EXTREME THREE EASTERN COUNTIES OF STAFFORD, PRATT AND BARBER WEDNESDAY, OR DAY 7. KNOCKED THOSE POPS DOWN TO 20 PERCENT, AS THE TIMING AND PLACEMENT OF THE NEXT WAVE COULD BE JUST ABOUT ANYWHERE AROUND THAT TIME. TEMPERATURES WILL BE RELATIVELY HOT DURING THE EXTENDED. OVERNIGHT MINIMUM TEMPERATURES WILL GENERALLY BE IN THE MID 60S TO LOWER 70S (SE, PRATT AND BARBER COUNTIES), WITH PERHAPS MONDAY NIGHT/TUESDAY MORNING THE COOLEST MORNING WITH MIN TEMPS FROM THE LOWER 60S IN SCOTT CITY TO 70 DEGREES IN MEDICINE LODGE. MAXIMUM TEMPERATURES WILL START OUT FRIDAY IN THE LOWER 90S NORTH OF I-70 AND RANGE TO THE MID 90S ALONG THE OKLAHOMA BORDER. BY SUNDAY, MAXIMUM TEMPERATURES WILL BE IN THE LOWER TO MID 90S ACROSS ALL OF SOUTHWEST KANSAS, THEN WARM TO PERHAPS THE WARMEST DAY MONDAY. HIGHS MONDAY SHOULD TOP OUT IN THE MID TO UPPER 90S, WITH THE ELKHART AREA BEING NEAR THE CENTURY MARK. THE WEAK COLD FRONT WILL SLIP THROUGH MONDAY NIGHT (BEST GUESS), AND KNOCK HIGHS DOWN A NOTCH INTO THE LOWER TO MID 90S BOTH TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1257 PM CDT WED JUN 13 2012 A NARROW STRIP OF MID LEVEL (9-10KFT) LEVEL ACCAS WAS NOTED ON VISIBLE SATELLITE BETWEEN KDDC AND KHYS. OTHER THAN THIS STRIP OF CLOUDS, THE SKY WAS CLEAR ACROSS THE AREA. MID LEVEL INSTABILITY MAY ALLOW ADDITIONAL CLOUDS TO DEVELOP THROUGH THE AFTERNOON ON THE MID LAYERS, AND VERY SMALL CONVECTIVE CHANCES ARE ANTICIPATED FOR THE EVENING (AFTER 00 UTC PERIOD). AND STORMS THAT MIGHT DEVELOP WILL PROBABLY BE HIGH BASED AND ONLY MAY AFFECT THE KGCK TERMINAL. CONFIDENCE IS LOW ENOUGH HOWEVER TO NOT MENTION AT THIS TIME IN THE KGCK TERMINAL AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... DDC 67 96 70 93 / 20 20 20 20 GCK 68 97 70 93 / 20 20 30 20 EHA 67 96 69 91 / 20 20 20 20 LBL 68 96 71 93 / 20 10 20 20 HYS 68 97 68 90 / 20 30 50 20 P28 68 95 76 94 / 20 20 20 20 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...RUSSELL SHORT TERM...RUSSELL LONG TERM...BURKE AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
627 PM EDT WED JUN 13 2012 .SYNOPSIS... HIGH PRESSURE WILL BRING DRY AND COOL AIR OVER THE UPPER OHIO VALLEY OVERNIGHT THROUGH THE END OF THE WEEK. THE STRETCH OF NICE WEATHER WILL CONTINUE THROUGH THE WEEKEND. && .NEAR TERM /THROUGH THURSDAY/... AN EARLY EVENING ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED WITH LITTLE CHANGE OTHER THAN TO INCREASE SKY GRIDS SLIGHTLY OVERNIGHT AS CIRRUS PASSES OVER THE AREA. THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE AXIS CENTERED ACROSS THE UPPER OHIO VALLEY WITH A DEEP LAYER OF DRY AIR IN PLACE. AT THE SURFACE, HIGH PRESSURE IS CENTERED ACROSS MICHIGAN. IN THIS PATTERN, SKIES ARE CLEAR WITH LIGHT AND NORTHERLY WINDS ACROSS THE AREA. THE MID-LEVEL RIDGE AXIS WILL SLOWLY NUDGE EASTWARD OVERNIGHT WITH THE HIGH SHIFTING INTO EASTERN CANADA ON THURSDAY. THE DRY PROFILE ALOFT WILL REMAIN IN PLACE ASIDE FROM SOME THIN CIRRUS CROSSING THE AREA OVERNIGHT. CIRRUS WILL PASS ON THURSDAY, WITH ANOTHER CLEAR DAY EXPECTED ACROSS THE AREA. DESPITE THIN CIRRUS CROSSING THE AREA, A STRONG RADIATIONAL COOLING NIGHT IS EXPECTED. OVERNIGHT LOWS ARE CLOSER TO THE WARMER MET GUIDANCE, RANGING FROM THE UPPER 40S TO LOWER 50S. WITH 850 TEMPS WARMING TO 11-13C TOMORROW AND ABUNDANT SUNSHINE, HIGHS WILL WARM TO NEAR NORMAL SEASONAL VALUES. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/... STRONG SURFACE HIGH TONIGHT WILL STAY OVER THE GREAT LAKES AND BRING LIGHT NORTH WINDS TO THE REGION. RADITIONAL COOLING WILL BRING TEMPERATURES DOWN TO THE 50S AND 40S. SURFACE HIGH AND STRENGTHENING EASTERN RIDGE WILL ALLOW FOR COMFORTABLE CONDITIONS AND PLENTY OF SUNSHINE THROUGH THE REST OF THE PERIOD. NEAR NORMAL TEMPS THURSDAY THROUGH SATURDAY WITH JUST A COUPLE OF DEGREES ABOVE THE NORMAL HIGH. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... SATURDAY NIGHT THROUGH WEDNESDAY...MODEL AGREEMENT IS RATHER STRONG WITH REGARD TO THE DEVELOPMENT AND AMPLIFICATION OF AN UPPER RIDGE OVER THE EASTERN THIRD OF THE U.S. THROUGH THE EXTENDED FORECAST PERIOD. RUN-TO-RUN MODEL VARIATION HAS BEEN VIRTUALLY NIL...AND OTHER THAN A POSSIBLE IMPULSE RUNNING OVER THE RIDGE AXIS...THE CHANCES FOR PRECIPITATION THROUGHOUT THE EXTENDED FORECAST ARE FAIRLY LOW. WITH SURFACE HIGH PRESSURE IN CONTROL AND AN UPPER RIDGE AXIS TRANSITING THE AREA...COMPRESSIONAL WARMING AND INCREASING MIXING BEYOND NEXT WEEKEND WILL ALLOW TEMPERATURES TO SURGE WELL ABOVE NORMAL. AS MODEL CONSENSUS 850 MB TEMPERATURES RUN FROM ROUGHLY 16C UP TOWARD 20C...THE POSSIBILITY OF ECLIPSING 90F IN SOME LOCATIONS INCREASES DAY-BY-DAY THROUGH THE MIDDLE OF NEXT WEEK. AT THIS TIME...THE RIDGE BREAKDOWN FOR OUR AREA STILL SEEMS TO BE FAR ENOUGH OUT INTO THE FUTURE TO BE BEYOND THE FORECAST PERIOD...HOWEVER THE ECMWF BECOMES SOMEWHAT FLATTER BY THE MIDDLE OF NEXT WEEK SUCH THAT A FEW SHOWERS OR THUNDERSTORMS IN AFTERNOON INSTABILITY CANNOT BE RULED OUT...PARTICULARLY NORTH OF PITTSBURGH. HOWEVER...ALL THINGS CONSIDERED...A DRY SUMMERLIKE PATTERN LOOKS TO CONTINUE FOR THE EASTERN THIRD OF THE COUNTRY. FRIES && .AVIATION /22Z WEDNESDAY THROUGH MONDAY/... HIGH PRESSURE WILL TRANSIT THE GREAT LAKES...LEAVING OUR AREA TO ITS SOUTH OVER THE NEXT 24-30 HOURS. OVERNIGHT INVERSIONS SHOULD FORM AND ALLOW LIGHT/VARIABLE WINDS EVERYWHERE...HOWEVER AS DAYTIME THURSDAY ENSUES...WINDS SHOULD TURN LIGHT EASTERLY FOR US AROUND THE SOUTH SIDE OF THE SURFACE HIGH. SKIES SHOULD REMAIN MOSTLY CLEAR WITH ONLY AN OUTSIDE SHOT AT SOME CIRRUS...SO VFR CONDITIONS WILL BE THE RULE. .OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY... HIGH PRESSURE WILL ALLOW FOR VFR CONDITIONS TO PREVAIL ACROSS THE TERMINALS THROUGH SUNDAY. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
102 PM CDT WED JUN 13 2012 .AVIATION...18Z TAFS FOR KOMA...KLNK AND KOFK. VFR TO MVFR CONDITIONS THROUGH THE FORECAST PERIOD. THERE IS A SLIGHT CHANCE OF -TSRA PRIMARILY AT KOFK IN THE 03Z TO 06Z TIME FRAME. OTHERWISE THE WEATHER FEATURE WILL BE THE BREEZY SOUTHEAST WINDS 10 TO 15 KTS WITH GUSTS 25 TO 28KTS UNTIL 01Z. COLD FRONT WILL APPROACH THE FORECAST AREA PRODUCING THREAT OF TSRA...ESPECIALLY KOFK AREA...BY THE END OF THE FORECAST PERIOD. && .PREV DISCUSSION... /ISSUED 614 AM CDT WED JUN 13 2012/ 88D MOSAIC THIS MORNING SHOWING NARROW LINE OF BOWED-OUT ELEVATED CONVECTION DRIVING EWD INTO ERN SD/ERN NEB. ACTIVITY WAS OCCURRING WITHIN AREA OF STRONG LAYER DIFFERENTIAL DIVG/850MB WAA WITH A LLVL MOIST FEED UP THRU THE CNTRL PLAINS. HRRR AND RAP SUGGESTING ACTIVITY SHOULD BE OUT OF THE CWA SOMETIME AROUND RUSH HOUR. ON THE WHOLE...MODELS CONTINUE TO BE IN REASONABLY GOOD AGREEMENT THAT LARGE SCALE FLOW OVER THE NEXT WEEK WILL TRANSITION FROM NEAR ZONAL OVER THE CONUS TO A RELATIVELY STAGNANT SITUATION WITH A BROAD TROF COVERING THE WRN CONUS AND A RIDGE TO THE EAST. ALSO GOOD AGREEMENT THAT BULK OF ACCUMULATING PCPN WILL GENERALLY OCCUR OVER THE UPPER MIDWEST...ERN DAKOTAS...WRN IA...ERN NEB THRU DAY 7. ALL THIS IN PART TO A PROLONGED MID LYR BNDRY ORIENTED PARALLEL TO SW-NE FLOW ALOFT WITH SUSTAINED LLVL MOISTURE TO FEED ON PER MOISTURE TRANSPORT PROGS. LIFTING MECHANISM THOUGH WILL BE MEANDERING SOMEWHAT DURING THIS TIME...MAKING IT IMPOSSIBLE TO PIN DOWN POPS WITHIN THE CWA. THUS...BECAUSE OF UNCERTAINTIES WILL OPT TO JUST BLANKET THE AREA WITH SMALL POPS. DEE && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1252 PM EDT WED JUN 13 2012 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE NORTH AND MOVE ACROSS THE AREA THIS EVENING. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO REDEVELOP ACROSS THE EASTERN CAROLINAS THIS AFTERNOON...WITH THE BEST CHANCE ALONG THE COAST. HIGH PRESSURE WILL BUILD IN LATE TONIGHT AND THURSDAY...BRINGING A RELATIVELY COOL AND DRY PATTERN WHICH WILL PERSIST INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM WEDNESDAY...NORTHERLY SURFACE WINDS ARE WELL- ESTABLISHED...BUT LOW-LEVEL MOISTURE IS HANGING TOUGH WITH DEWPOINTS STILL WITHIN A FEW DEGREES OF 70 THROUGHOUT THE AREA. AN AREA OF ENHANCED CUMULUS MOVING SOUTHWARD ACROSS EAST-CENTRAL NC IS ASSOCIATED WITH THE ACTUAL SURFACE COLD FRONT. CONVECTION MAY FIRE ALONG THIS FEATURE STARTING WITHIN THE NEXT 90 MINUTES. WE`VE TWEAKED HIGH TEMPERATURES UPWARD BASED ON LATEST OBSERVATIONS... ESPECIALLY NEAR THE COAST. OTHER CHANGES WERE MINOR. PREVIOUS DISCUSSION FROM 10 AM FOLLOWS... SURFACE WINDS HAVE SHIFTED NORTHWESTERLY ALL THE WAY DOWN TO THE BEACHES THIS MORNING AS A SURFACE TROUGH HAS PUSHED OFF THE COAST. THE ACTUAL SURFACE COLD FRONT IS LAGGING THIS WIND SHIFT AND SHOULD MAKE IT OFFSHORE EARLY THIS EVENING. WE`RE LOSING THE DEEP TROPICAL MOISTURE AS MID-LEVEL WINDS HAVE SHIFTED NORTHWESTERLY BEHIND A DEPARTING UPPER LEVEL TROUGH. PRECIPITABLE WATER VALUES (CURRENTLY 1.75 INCHES) SHOULD FALL THROUGHOUT THE DAY AND INTO TONIGHT AS DRIER AIR BUILDS IN MAINLY AT AND ABOVE 700 MB. WITH MANY MORE BREAKS EXPECTED IN LOW AND MID-LEVEL CLOUD COVER TODAY COMPARED TO THE PAST SEVERAL DAYS HIGH TEMPERATURES SHOULD MAKE IT INTO THE 80S EVERYWHERE...WITH SOME UPPER 80S EVEN POSSIBLE NEAR AND WEST OF LUMBERTON...DILLON AND FLORENCE. THIS WILL STEEPEN LOW-LEVEL LAPSE RATES SIGNIFICANTLY AND SHOULD CREATE SCATTERED SHOWERS AND STORMS THIS AFTERNOON. LATEST HRRR MODEL RUNS SHOW WE SHOULD EXCEED CONVECTIVE TRIGGER TEMPERATURE BETWEEN 17-18Z...1-2 PM EDT. LOWER PRECIP WATER VALUES WILL NOT BE ABLE TO COMPLETELY NEGATE THE THREAT OF MORE HEAVY RAINFALL AND ISOLATED FLOODING DUE TO SLOW CELL MOTION EXPECTED TO BE FROM NORTH TO SOUTH AT ONLY 10-12 MPH. THERE WILL ALSO BE A THREAT OF GUSTY WINDS AS DRIER AIR ALOFT IS ENTRAINED INTO THE STORM CELLS WITH DCAPE VALUES INCREASING TO 1000 J/KG OR MORE. CONVECTIVE ACTIVITY SHOULD END FROM NORTH TO SOUTH THIS EVENING AS THE ACTUAL COLD FRONT PUSHES OFFSHORE AND DRIER MORE STABLE AIR BUILDS IN. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...MAIN FORECAST CHALLENGE FOR THE SHORT TERM WILL BE TEMPERATURES AS MOISTURE WILL BE ON THE DECREASE AS AN OMEGA CONFIGURATION DEVELOPS AT THE MID LEVELS. AT THE SURFACE A FORMIDABLE NORTHEAST FLOW WILL DEVELOP AS HIGH PRESSURE BUILDS DOWN FROM THE NORTHEAST AND LOW PRESSURE MEANDERS NEAR BERMUDA. MET GUIDANCE IS QUITE A BIT WARMER AS OPPOSED TO THE MAV NUMBERS THROUGH THE PERIOD MORE-SO THURSDAY. THIS APPEARS TO BE A FUNCTION OF LINGERING LOW LEVEL MOISTURE VIA THE GFS. NUMBERS JOG TOWARD SLIGHTLY BETTER AGREEMENT FRIDAY. HAVE LEANED TOWARD THE COOLER MAV NUMBERS OPTING FOR A SLOWER PROGRESSION OF THE LOW LEVEL MOISTURE. NO POPS THROUGH THE PERIOD. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...NO SIGNIFICANT CHANGES TO THE MEDIUM RANGE GUIDANCE THIS MORNING AS THE FORECAST AREA CONTINUES TO BE SITUATED IN THE EASTERN PART OF A MID LEVEL OMEGA PATTERN FOR MOST OF THE PERIOD. I DID INCREASE THE POPS INCREMENTALLY SUNDAY AND MONDAY TO SLIGHT CHANCE TO MATCH HPC AND ADJACENT OFFICES VIA NORTHEAST RESULTANT SEA BREEZE COMBINED WITH THE 700MB SUBSIDENCE INVERSION ABATING. THE PATTERN BEGINS TO CHANGE LATE IN THE PERIOD WITH THE GFS ADVERTISING A REX BLOCK DEVELOPING SO CONFIDENCE IS BELOW AVERAGE. NO CHANGES TO TEMPERATURE FORECAST. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...ENHANCED CUMULUS VISIBLE ON SATELLITE DROPPING SOUTHWARD FROM EAST-CENTRAL NORTH CAROLINA ALONG AT LEAST TWO FRONTAL-LIKE BOUNDARIES. EXPECT SCATTERED CONVECTION TO FIRE ALONG THESE BOUNDARIES...MAINLY BETWEEN 19-23Z. COVERAGE WILL BE ABOUT 50 PERCENT OF THE AREA. AFTER SUNSET MODELS ARE SHOWING QUITE A BIT OF ATLANTIC STRATOCUMULUS ADVECTING SOUTHWESTWARD AS SFC LOW PRESSURE DEVELOPS WELL OFFSHORE. THESE CLOUD BASES COULD LOWER TO MVFR OVERNIGHT. WILL KEEP THINGS VFR AT THIS TIME BUT CONFIDENCE IS NOT HIGH. THURSDAY...PREDOMINANTLY VFR WITH CONTINUED NORTHEAST FLOW. EXTENDED OUTLOOK...MAINLY VFR THROUGH THE FORECAST PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM WEDNESDAY...NO SIGNIFICANT CHANGES TO THE MARINE FORECAST WITH THIS EARLY AFTERNOON NEAR-TERM UPDATE. PREVIOUS DISCUSSION FROM 10 AM FOLLOWS... THUNDERSTORM ACTIVITY HAS PUSHED WELL OFFSHORE AND INTO THE GULF STREAM...WITH LIGHTER SHOWERS NOW ENDING ACROSS THE COASTAL WATERS. THERE SHOULD BE A LULL IN CONVECTION LASTING THROUGH EARLY AFTERNOON BEFORE ADDITIONAL SHOWERS AND THUNDERSTORMS DEVELOPING INLAND BEGIN TO MOVE OFFSHORE...AFFECTING THE COASTAL WATERS THROUGH THIS EVENING. WINDS HAVE SHIFTED TO THE WEST OR NORTHWEST THIS MORNING AS A TROUGH HAS PUSHED OFF THE COAST. THE ACTUAL SURFACE COLD FRONT IS STILL WELL INLAND AND SHOULD WAIT UNTIL THIS EVENING TO PUSH OFF THE COAST. SEAS CURRENTLY RANGE FROM 2-3 FT NEAR THE COAST...BUT EARLIER SHOWER/STORM ACTIVITY HAS BUILT SEAS TO AROUND 5 FT AT THE FRYING PAN SHOALS BUOY AND AT THE OFFSHORE LEJEUNE BUOY. SEA HEIGHTS SHOULD DIMINISH THROUGH EARLY EVENING...BUT MAY BEGIN TO BUILD LATER TONIGHT AS INCREASING NORTHEAST WINDS DEVELOP BEHIND THE ACTUAL COLD FRONT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...A NORTHEASTERLY FLOW WILL PREVAIL THROUGHOUT THE PERIOD AS HIGH PRESSURE BUILDS DOWN FROM THE NORTHEAST AND LOW PRESSURE SLOWLY DEVELOPS WELL INTO THE ATLANTIC. STRONGEST WINDS OCCUR LATE FRIDAY WHEN THE 20-25 KNOT RANGE WILL LIKELY BE CLOSER TO THE HIGH END OF THE RANGE. THE PERSISTENT FETCH WILL ALLOW SEAS TO BUILD LATE THURSDAY TO ECLIPSE THE SIX FOOT SMALL CRAFT CRITERIA AND CONTINUE THROUGH THE REMAINDER OF THE PERIOD. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...ESSENTIALLY NO CHANGES TO THE EXTENDED COASTAL WATERS FORECAST AS A NORTHEASTERLY FLOW SHOULD PREVAIL. MAY SEE MORE VEERING SUNDAY AFTERNOON AS THE FLOW IS LIGHTER ALLOWING MORE OF A NORTHEAST RESULTANT TO DEVELOP. THE CAVEAT WITH THIS TYPE OF SCENARIO ARE THE EMBEDDED SURGES. I DID WALK BACK SEAS SLIGHTLY BUT A SMALL CRAFT ADVISORY MAY STILL BE NEEDED BUT IT APPEARS MORE MARGINAL AT THIS POINT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...SHK LONG TERM...SHK AVIATION...DL/TRA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
310 PM CDT WED JUN 13 2012 .SHORT TERM... CONVECTION CHANCES THROUGHOUT THE PERIOD...INCLUDING THE POSSIBILITY OF SEVERE LATE TONIGHT...WILL BE THE PRIMARY FORECAST HEADACHE FOR THE SHORT TERM. WV LOOP SHOWS THE SHORTWAVE TROUGH THAT BROUGHT SHOWERS TO CENTRAL MN DURING THE DAY TODAY HEADING OFF TO THE EAST...WITH THE NEXT SHORTWAVE OVER MT. VIS SAT LOOP HAS SOME FAIRLY VIGOROUS TOWERING CU OVER THE WESTERN CWA...WHICH FITS WITH MODEL SOUNDINGS SHOWING AROUND 800 J/KG AND NOT MUCH CAP. HOWEVER...DEVELOPMENT OF ECHOES ON RADAR HAS NOT REALLY BEEN HAPPENING...AND SPC MESOANALYSIS HAS THE BEST CAPE FURTHER NORTH AND WEST. HRRR HAS SOME BLIPS IN OUR SOUTHWESTERN COUNTIES DURING THE LATE AFTERNOON AND EVENING...BUT QUICKLY DISAPPEARING AND MOST OF THE ACTIVITY COMING IN LATER TONIGHT AS THE MAIN SHORTWAVE COMES EAST. WILL KEEP AN EYE ON SATELLITE/RADAR TRENDS...BUT MAY HAVE TO INCLUDE SOME LOW POPS FOR OUR SOUTHWESTERN COUNTIES IN CASE SOMETHING CAN GET GOING THIS EVENING. ALL MODELS ARE IN FAIRLY GOOD AGREEMENT ON DEVELOPING STORMS OUT IN THE WESTERN DAKOTAS WHERE THE BEST INSTABILITY CURRENTLY IS...AND BRINGING SOMETHING EASTWARD INTO THE CWA BY MORNING. THERE IS A FAIR AMOUNT OF ELEVATED CAPE OVER THE SOUTHWESTERN COUNTIES BY 12Z...AND DEEP LAYER BULK SHEAR INCREASES INTO THE 60 TO 70 KT RANGE. THINK THAT THE PRECIP COULD COME EASTWARD AS A POSSIBLY SEVERE MCS AFTER MIDNIGHT TONIGHT. INCREASED POPS TO 70 PERCENT OVER OUR SOUTHEASTERN COUNTIES...AND PUT IN A SEVERE MENTION. WITH PWATS GETTING UP TO AROUND 1.5 INCHES...HEAVY RAIN COULD BE A POSSIBILITY. THE UPPER TROUGH WILL MOVE OFF INTO SOUTHERN MANITOBA TOMORROW...PUSHING THE SFC TROUGH AXIS EASTWARD THROUGH THE CWA. THUNDERSTORM ACTIVITY SHOULD PUSH EASTWARD AND BE MOSTLY IN MN BY TOMORROW AFTERNOON. WILL CONTINUE TO HAVE TO WATCH FOR SEVERE TOMORROW AFTERNOON AS MODELS CONTINUE TO SHOW A GOOD AMOUNT OF CAPE ABOVE 1500 J/KG AND BULK SHEAR OVER 50 KTS. JUST INCLUDED LIKELY POPS MENTION THOUGH AND LEFT SEVERE MENTION OUT FOR NOW. THURSDAY NIGHT AND FRIDAY SHOULD BE FAIRLY QUIET AS WE SEE SOUTHWESTERLY FLOW ALOFT BETWEEN SYSTEMS. SFC PATTERN WILL BE FAIRLY WEAK...WITH ANOTHER TROUGH NOT COMING IN UNTIL THE NEXT SYSTEM STARTS APPROACHING FRIDAY NIGHT. MODELS SHOW SOME DIFFERENCES IN TIMING ON THE NEXT SHORTWAVE...WITH THE NAM MOST PROGRESSIVE ON BRINGING THE TROUGH OUT INTO THE PLAINS. LEANED TOWARDS THE SLOWER GFS AND ECMWF. CONTINUED TO KEEP POPS IN THE 50-70 PERCENT RANGE FOR LATE FRIDAY NIGHT INTO SATURDAY. TEMPERATURES WILL CONTINUE TO BE FAIRLY WARM...PARTICULARLY FRIDAY AS BOTH THE NAM AND GFS HAVE 850MB TEMPS APPROACHING 20 C IN THE SOUTHERN RED RIVER VALLEY. CONTINUED TO KEEP HIGHS IN THE UPPER 70S TO LOW 80S...WITH SOME SLIGHTLY COOLER TEMPS SATURDAY AFTERNOON. LOWS WILL BE MAINLY IN THE UPPER 50S AND 60S. .LONG TERM... /SAT NIGHT THROUGH WED/ UPPER WAVE/LOW OVER SOUTH CNTRL CANADA WILL RESULT IN A SERIES OF WAVES MOVING ACROSS THE NORTHERN TIER... RESULTING IN A CHANCE OF TSTMS OR SHOWERS THROUGHOUT THE MAJORITY OF THE PERIOD. BEST CHANCE TO NOT SEE ACTIVITY WILL BE SAT NIGHT...AS UPPER WAVE EXITS EASTERN ZONES AND SUBSIDENCE SETS IN. SUN MORNING SHOULD BE DRY AS WELL...BEFORE THE POTENTIAL FOR CONVECTION INCREASES AGAIN BY SUN AFTN. TEMPS WILL GENERALLY BE IN THE 70S AS THE PERIOD WILL BE RATHER CLOUDY. && .AVIATION... CU FIELD WILL SPREAD SOUTH TO NORTH THROUGHOUT THE AFTERNOON AND INTO THE EVENING...BUT SHOULD DISSIPATE AFTER SUNSET. MAY SEE SOME BREAKS IN CLOUDS TONIGHT...BUT MID LEVEL DECK WILL PUSH INTO AREA OVER NIGHT. EXPECT TO SEE SOME SHOWERS AND THUNDERSTORM ACTIVITY FROM THE SOUTHERN VALLEY THROUGH THE BJI AREA....AND MORE ISOLATED ACTIVITY AT GFK...TVF AND DVL. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ JR/SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
257 PM CDT WED JUN 13 2012 .SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT... MAIN FORECAST PROBLEM IS THUNDERSTORM CHANCES TONIGHT. CURRENTLY...SURFACE LOW PRESSURE IS SITUATED OVER SOUTHEAST MONTANA WITH SOUTHERLY FLOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA. SHORTWAVE LIFTING FROM NORTHERN MONTANA IN TO SOUTHERN SASKATCHEWAN IN PRODUCING A BAND OF SHOWERS THAT IS LIFTING ACROSS NORTHWEST NORTH DAKOTA. MOISTURE CONTINUES TO INCREASE OVER THE REGION WITH DEWPOINTS CURRENTLY IN THE MID 50S. MODELS INDICATE SCATTERED CONVECTION DEVELOPING ALONG THE EASTERN MONTANA COLD FRONT AS IT PUSHES INTO WESTERN NORTH DAKOTA. THE ONGOING CONVECTION IN THE NORTHWEST MAY ACTUALLY INHIBIT DESTABILIZATION...BUT WEST CENTRAL AND SOUTHWEST NORTH DAKOTA WILL SEE MORE SUN THIS AFTERNOON WHICH SHOULD HELP LOWER CONVECTIVE INHIBITION. CONVECTION WILL HAVE A SLIGHT TO MODERATELY UNSTABLE ATMOSPHERE TO WORK WITH INITIALLY WITH DECENT 0-6KM SHEAR. IN ADDITION...INCREASING LOW LEVEL MOISTURE IS NOT UNDERDONE BY FORECAST MODELS. AS CONVECTION TRACKS INTO CENTRAL NORTH DAKOTA SHEAR AND CAPE REMAIN BUT THE CAP STRENGTHENS AS YOU MOVE EAST FROM BISMARCK TO JAMESTOWN. HIGH RESOLUTION MODELS SEEM TO HIT ON THIS WITH THIS INITIAL CONVECTION HAVING A HARD TIME HOLDING TOGETHER AS IT MOVES INTO CENTRAL NORTH DAKOTA. A STRONG SHORTWAVE MOVING THROUGH WESTERN MONTANA THIS AFTERNOON WILL BE THE TRIGGER FOR EITHER ADDITIONAL THUNDERSTORM DEVELOPMENT THIS EVENING OR A STRENGTHENING OF CONVECTION THAT DEVELOPS THIS AFTERNOON ALONG THE EASTERN MT COLD FRONT. THE LATEST HRRR INDICATES CONVECTION DEVELOPING OVER THE NORTHERN HIGH PLAINS AND MOVING INTO THE WESTERN DAKOTAS BY MID EVENING AND TRACKING ACROSS THE LOCAL AREA LATE THIS EVENING AND OVERNIGHT. EML ADVECTING INTO THE REGION WILL MAINTAIN STEEP LAPSE RATES OVER THE FORECAST AREA TONIGHT. THIS CONVECTION MAY INITIALLY FORM AS DISCRETE SUPERCELLS BUT THEN DEVELOP INTO A LINEAR CONVECTIVE SYSTEM AS IT TRAVERSES THE AREA TONIGHT. ALTHOUGH A TORNADIC SUPERCELL CANNOT BE RULED OUT LATE THIS AFTERNOON OR THIS EVENING...THE MAIN THREAT OVERNIGHT WOULD BE LARGE HAIL AND DAMAGING WINDS. WITH PWATS INCREASING WELL ABOVE NORMAL...HEAVY RAIN CAN ALSO BE EXPECTED...ESPECIALLY FROM FROM THE FAR SOUTH CENTRAL INTO THE JAMES RIVER VALLEY. THIS AREA HAS NOT SEEN SIGNIFICANT RAINFALL LATELY AND THE PROGRESSIVE NATURE OF THE SYSTEM...WILL NOT ISSUE ANY HYDRO HEADLINES. PRECIPITATION MAY BE LINGERING IN THE FAR EAST ON THURSDAY MORNING. OTHERWISE THE MAJORITY OF THE DAY WILL BE DRY ACROSS THE SOUTHERN TWO THIRDS OF THE CWA. THE FAR NORTH WILL SEE A CHANCE OF SHOWERS AS THE UPPER LOW TRACKS ACROSS SOUTHERN CANADA. THE SHORT LIVED DRY SPELL SHOULD CONTINUE THROUGH THURSDAY NIGHT WITH UPPER LEVEL RIDGING OVER THE LOCAL AREA AHEAD OF THE NEXT SYSTEM. .LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY... POTENT UPPER LEVEL WAVE/MID LEVEL CLOSED LOW WILL LIFT ACROSS THE ROCKIES AND THROUGH THE NORTHERN PLAINS FRIDAY-SATURDAY BRINGING LIKELY SHOWERS AND THUNDERSTORMS TO MOST LOCATIONS. UNCERTAIN IF WE WILL SEE WIDESPREAD SEVERE WEATHER THOUGH WITH DAYTIME HEATING ON FRIDAY LIMITED ALONG WITH MARGINAL CAPE. SCALED BACK CONSIDERABLY ON POPS SATURDAY AFTERNOON WITH DRY AIR PUNCHING INTO THE REGION FROM SOUTHWEST TO CENTRAL. LEFT CHANCES IN EAST FOR LINGERING SHOWERS/THUNDER...AND CHANCES ACROSS THE NORTH NEAR THE TRACK OF THE MID LEVEL LOW. DRY CONDITIONS REGION WIDE SATURDAY NIGHT WITH A WEAK RIDGE PUSHING ACROSS THE NORTHERN PLAINS. AFTERWARDS (SUN-WED)...OUR WEATHER PATTERN RETURNS TO VERY ACTIVE AS THE UPPER LEVEL JET BECOMES ORIENTATED OVER THE NORTHERN CONUS AND STEERS SEVERAL MID LEVEL DISTURBANCES FROM ACROSS THE ROCKIES INTO THE NORTHERN PLAINS. SHOULD SEE A GOOD CHANCE FOR PRECIPITATION EACH PERIOD. TEMPERATURES WILL AVERAGE NEAR NORMAL THROUGH THIS WEEKEND...TRENDING TO NEAR TO SLIGHTLY BELOW NORMAL MON-WED. && .AVIATION... AN AREA OF SURFACE LOW PRESSURE ACCOMPANIED BY AN UPPER LEVEL SHORTWAVE WILL COMBINE WITH INCREASINGLY UNSTABLE CONDITIONS TO BRING THUNDERSTORMS TO WESTERN INTO CENTRAL NORTH DAKOTA THIS AFTERNOON AND EVENING. MENTIONED VCTS GROUPS FOR ALL BUT KJMS. HEAVIER THUNDERSTORMS ARE POSSIBLE LATER THIS EVENING AND OVERNIGHT BEFORE 10Z MAINLY FOR KDIK...KBIS...AND KJMS. WHILE VFR CONDITIONS SHOULD PREVAIL FOR THE MAJORITY OF THE PERIOD...MVFR-IFR CONDITIONS CAN BE EXPECTED WITH ANY THUNDERSTORMS WHICH PASS OVER TERMINALS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...TWH LONG TERM/AVIATION...NH
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
559 PM CDT WED JUN 13 2012 .DISCUSSION... SEE 00Z AVIATION DISCUSSION BELOW. && .AVIATION... VFR CONDITIONS ARE EXPECTED THE NEXT 24 HOURS. WINDS WILL BE SOUTH AT 10 TO 15 KNOTS WITH A FEW GUSTS TO 20 KNOTS. WATCHING A FEW TSTMS OVER SOUTHWEST TEXAS. THIS ACTIVITY WILL PROBABLY REMAIN WELL WEST OF THE TERMINALS. 21 && .PREV DISCUSSION... /ISSUED 348 PM CDT WED JUN 13 2012/ SHORT TERM... WE HAD ISOLATED WEAK CONVECTION EARLY TODAY BUT THIS HAS SINCE DISSIPATED. SKIES HAVE BECOME MOSTLY CLEAR TO PARTLY CLOUDY ACROSS THE CWA LIKELY IN RESPONSE TO SUBSIDENCE IN THE WAKE OF THE DEPARTING MCV ALONG THE RED RIVER VALLEY. A WEAK SURFACE...YET DISCERNIBLE...BOUNDARY STILL EXISTS OVER THE SOUTHWEST CWA PER THE KSJT WSR-88D BUT THIS FEATURE REMAINS BENIGN AT THIS TIME. LOOKING WEST...MID LEVEL RADAR ECHOES HAVE BEEN INCREASING ACROSS SOUTHWEST TX THIS AFTERNOON AHEAD OF AN APPROACHING SHORTWAVE. AS THIS SYNOPTIC SCALE ASCENT OVERSPREADS THE AREA AND SURFACE TEMPS WARM INTO THE MID/UPPER 90S...I ANTICIPATE CONVECTION DEVELOPING IN THE VICINITY OF THE CWA. CONFIDENCE IS FAIRLY LOW THAT WE WILL SEE WIDESPREAD THUNDERSTORMS BUT SEVERAL VERSIONS OF THE HIRES WRF AND THE HRRR ALL AGREE IN THUNDERSTORMS FORMING OVER THE CENTRAL/EASTERN COUNTIES. A LOOK AT THE SPC MESO ANALYSIS PAGE DEPICTS SBCAPE VALUES ON THE ORDER OF 2500-3500 J/KG WITH EFFECTIVE SHEAR VALUES BETWEEN 40-50 KTS. THE QUESTION WILL BE WHETHER OR NOT THE CAP WILL GIVE WAY. THUS...WE DO HAVE A CONDITIONAL THREAT FOR SEVERE WEATHER BUT I AM PLAYING THIS RATHER CONSERVATIVE FOR NOW THINKING THAT THE CAP WILL HOLD FOR THE MOST PART AND ANY CONVECTIVE INITIATION WILL LIKELY BE DELAYED UNTIL WELL AFTER PEAK HEATING. THUS...I AM ONLY CARRYING 20 POPS FOR THE PERIOD BEGINNING AT 00Z. OVERNIGHT TEMPS WILL FALL INTO THE LOWER 70S /BUT WILL LIKELY BE LOWER IF CONVECTION DOES DEVELOP/. GENERALLY DRY AND WARM CONDITIONS ARE EXPECTED FOR THURSDAY WITH SOUTH WINDS INCREASING TO 10-20 MPH ACROSS THE CWA. HIGHS ARE EXPECTED TO BE IN THE MID/UPPER 90S. JOHNSON LONG TERM... THURSDAY NIGHT INTO FRIDAY...THE UPPER LEVEL LOW THAT IS CURRENTLY OVER SOUTHERN CALIFORNIA TODAY WILL BE ENVELOPED BY ANOTHER LOW THAT WILL MOVE SOUTH ALONG THE CALIFORNIA COAST. THERE WILL BE AN UPPER LEVEL TROUGH OVER THE GULF COAST REGION AS WELL WHILE WEST CENTRAL TEXAS WILL BE IN BETWEEN UNDERNEATH RIDGING. FOR THIS REASON...WILL GO WITH TEMPERATURES SLIGHTLY WARMER THAN GUIDANCE FOR FRIDAY AND SATURDAY. HAVE NOT EXPANDED ANY OF THE INHERITED POPS FRIDAY AFTERNOON AND EVENING. IT STILL APPEARS THAT THE LOW WILL BE TOO FAR WEST TO DIRECTLY INFLUENCE US...AND THAT MOST OF THE CONVECTION WILL GET GOING IN THE HIGHER TERRAIN OF THE WEST TEXAS AREA...THEN MOVE SLOWLY TO THE NORTHEAST DURING THE EVENING HOURS...POSSIBLY MAKING THEIR WAY INTO OUR WESTERN TIER OF COUNTIES BEFORE DISSIPATING. THE UPPER LEVEL RIDGING EXPANDS THROUGH THE WEEKEND ACROSS TEXAS AND THE REST OF THE SOUTHWESTERN U.S. THIS WILL PUSH THE MID/UPPER LEVEL LOW BACK OUT TO THE PACIFIC...AND KEEP OUR TEMPERATURES WARMER THAN NORMAL WITH LITTLE CHANCE FOR PRECIPITATION. BY TUESDAY OF NEXT WEEK...A WEAK MID/UPPER LEVEL TROUGH DEVELOPS ACROSS THE EASTERN HALF OF TEXAS...AND LOOKS TO DRIFT SLOWLY WEST/SOUTHWEST ACROSS THE SOUTHERN HALF OF THE STATE. THIS COULD RESULT IN SOME LOWERED TEMPERATURES...AND THE GFS/ECMWF ALSO TRY TO SHOW SOME SHRA/TSRA DEVELOPING ACROSS OUR SOUTHEASTERN COUNTIES. WILL HOLD OFF ON INTRODUCING ANY WX AT THIS TIME...BUT IT WILL BE WORTH WATCHING. 20 && .PRELIMINARY POINT TEMPS/POPS... ABILENE 72 93 72 94 71 / 20 10 10 10 10 SAN ANGELO 73 98 73 98 71 / 20 10 10 10 10 JUNCTION 74 98 73 94 72 / 20 10 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
352 PM CDT WED JUN 13 2012 .SHORT TERM... BOUNDARY LAYER APPEARS TO BE FAIRLY STABLE OVER THE ROLLING PLAINS THANKS TO OUTFLOW FROM THE STORMS THAT ROLLED ACROSS THIS AREA EARLY THIS MORNING. ACROSS THE SOUTH PLAINS...LATEST VISIBLE SATELLITE SHOWS THAT CU FIELD IS TRYING TO DEVELOP AND DEEPEN. RAP BUFKIT SOUNDINGS CONTINUE TO INDICATE A WEAK CAP THAT IS BROKEN IN A COUPLE OF HOURS AT KLBB WHILE HOLDING THE CAP IN PLACE FURTHER WEST AT CLOVIS. SPC MESOSCALE ANALYSIS ALSO SHOWS THE CAP HOLDING OVER THE ROLLING PLAINS WITH AN UNCAPPED ATMOSPHERE OVER THE SOUTH PLAINS AND MLCAPE VALUES BETWEEN 3500-4000 J/KG. BULK SHEAR VALUES ARE A BIT LOWER THAN YESTERDAY OVER THE ENTIRE AREA BUT 30-40 KNOTS IS IN PLACE ACROSS THE SOUTHWESTERN QUARTER OF THE AREA. THESE FACTORS COULD POTENTIALLY RESULT IN RAPID DEVELOPMENT OF SEVERE STORMS /IF/ THEY ARE ABLE TO DEVELOP. NOT SURE WHAT TO MAKE OF THE POSSIBLE CAP OVER THE SOUTH PLAINS AND WHAT THIS MAY DO FOR OUR CHANCES OF CONVECTION AND ALSO MAKES IT DIFFICULT TO NAIL DOWN THE POP FORECAST FOR TONIGHT. WILL HOLD POPS IN THE LOW END OF CHANCE AS THE TTU/OUN WRF AND THE HRRR HAVE ALL BEEN CONSISTENT IN NOT GENERATING ANY STORMS OVER THE AREA...WITH THE EXCEPTION OF THE HRRR TRYING TO DEVELOP SOME STORMS LATE TONIGHT BETWEEN 03 AND 06Z. ALSO AM CONCERNED THAT THE INCOMING AREA OF ENHANCED CLOUD COVER ON VISIBLE SATELLITE MAY INDICATE SOME KIND OF POCKET OF COOLER AIR ALOFT AND SOME WEAK LIFT THAT MAY HELP STORMS TO FIRE. THE FLAVORS OF THE WRF HAVE SHOWN THAT ACTIVITY IN NORTHEAST NEW MEXICO MAY ORGANIZE INTO ANOTHER COMPLEX THAT COULD MOVE TOWARDS THE NORTHERN ROLLING PLAINS OVERNIGHT AND ONCE AGAIN HAVE KEPT SLIGHT CHANCE POPS ACROSS THIS AREA THROUGH TOMORROW MORNING. FOR THURSDAY...RIDGE AXIS TRIES TO PUSH OVERHEAD WHICH SHOULD HELP SUPPRESS CONVECTION A BIT BUT OPTED TO HOLD SLIGHT CHANCE POPS ACROSS THE WESTERN HALF DEPENDING ON HOW CONVECTION DEVELOPS TONIGHT. MODELS STILL SHOW CONVECTION DEVELOPING ACROSS THE HIGHER TERRAIN OF NM TOMORROW AFTERNOON SO CANNOT RULE OUT AN ISOLATED STORM OR TWO PUSHING TOWARDS THE STATE LINE. TEMPERATURES MAY ALSO BE A FEW DEGREES WARMER WITH THE RIDGE AXIS OVERHEAD BUT LOW-LEVEL MOISTURE MAY HELP TO LIMIT THE WARMUP SOMEWHAT. JORDAN && .LONG TERM... LATEST WATER VAPOR IMAGERY DISPLAYED A PACIFIC UL DISTURBANCE MOVING ACROSS CALIFORNIA...AND IS PROGGED TO DIG ESE TOWARDS THE DESERT SW TOMORROW NIGHT. THIS WILL PROMOTE SOUTHWESTERLY FLOW ALOFT...AND THUS PERMIT THE DRYLINE TO NEAR THE TEXAS/NEW MEXICO BORDER. FORECAST MODELS HINT AT ADEQUATE CONVERGENCE ALONG THE DRYLINE...SO MUCH SO THAT IT WILL OVERCOME THE LESS THAN 100 J/KG OF CIN. FURTHERMORE...A WEAK EMBEDDED IMPULSE MAY BE ENOUGH TO SPARK CONVECTION ALONG AND EAST OF THE DRYLINE...AS SOUTHEASTERLY SFC WINDS EAST OF THE DRYLINE INDUCE DEWPOINTS IN THE 50S AND 60S. CURRENT THINKING IS THAT THE SAID EMBEDDED IMPULSE WILL EJECT NE ACROSS THE PANHANDLES...HOWEVER WILL MAINTAIN SLIGHT CHANCE POPS ACROSS PORTIONS OF THE CENTRAL AND WESTERN ZONES...WHERE PROGGED SFC-BASED CAPE OF 1.0-1.5 KJ/KG EXISTS. IF STORMS DO INDEED DEVELOP...STRONG TO SEVERE STORMS WILL BE POSSIBLE WITH HAIL AND BRIEF GUSTY WINDS THE PRIMARY THREATS. FRIDAY THROUGH SUNDAY...THE PACIFIC UL DISTURBANCE WILL RETROGRADE WEST ACROSS THE EASTERN PACIFIC...WHILE CONCURRENTLY A PROGRESSIVE PATTERN ACROSS THE NORTHERN U.S. TIER ENSUES...WHICH WILL LEAD TO THE DRYLINE LINGERING ACROSS OR JUST WEST OF THE CWA. DESPITE SLIGHT HEIGHT INCREASES FROM AN UA RIDGE...MOIST LOW LEVELS WILL EXIST AS UPSLOPE SFC WINDS PERSIST /PWATS IN EXCESS OF 1.00 INCH/...AND MODEL SOUNDINGS EXHIBITING STEEPENED LAPSE RATES EACH AFTERNOON/EVENING /SFC-BASED CAPE OF 2.0-2.5 KJ/KG/ SUGGEST THE POTENTIAL FOR STRONG TO SEVERE STORMS MORESO ACROSS THE WESTERN ZONES NEAREST TO THE DRYLINE /HAIL AND GUSTY WINDS THE PRIMARY THREATS/. THE GFS MAINTAINS BEST POPS ACROSS EASTERN NEW MEXICO COINCIDING WITH THE DISPLACEMENT OF THE DRYLINE THROUGHOUT THE SAID PERIOD...WHILE THE NAM AND ECMWF SOLUTIONS ARE A BIT MORE ROBUST /DRYLINE A BIT CLOSER TO THE FA/. AS SUCH...STORMS APPEAR TO BE DEPENDENT ON THE EXACT LOCATION OF THE DRYLINE AND WILL THEREFORE OPT TO KEEP POPS BELOW 30 PERCENT ATTM. MONDAY THROUGH WEDNESDAY THE LONG TERM MODELS DIFFER A BIT IN REGARD TO THE SYNOPTIC PATTERN. THE GFS RETROGRADES THE UA RIDGE TO THE SOUTHWESTERN CONUS BY MONDAY AS AN EASTERN CONUS UA RIDGE PROMOTES AN UA LOW TO MOVE ACROSS SOUTHERN TEXAS AND PERHAPS ALLOW INCREASING CHANCES FOR PRECIP OFF THE CAPROCK TUESDAY-WEDNESDAY. THE ECMWF ON THE OTHER HAND ALSO DEVELOPS AN UA RIDGE ACROSS THE EASTERN CONUS...WHILE A TROPICAL SYSTEM TRANSLATES NORTH ACROSS OLD MEXICO THUS STREAMING LOW TO MID LEVEL MOISTURE ACROSS THE FA...AND A CHANCE FOR STORMS. FURTHERMORE...THE ECMWF HINTS AT THE BROAD UA TROUGH ACROSS THE NORTHERN U.S. TIER TO SURGE A RELATIVELY WEAK DRY COLD FRONT TO ACROSS FAR THE NWRN ZONES TUESDAY BEFORE QUICKLY RETREATING NORTH. WILL NEED TO ANALYZE FUTURE MODEL RUNS FOR CONSENSUS...AND WILL THEREFORE OPT TO MAINTAIN SILENT POPS BEYOND SUNDAY NIGHT ATTM. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 61 93 64 92 62 / 40 20 20 30 30 TULIA 66 91 65 91 65 / 30 20 20 20 20 PLAINVIEW 69 92 67 91 67 / 30 20 20 20 20 LEVELLAND 69 95 67 93 66 / 30 20 20 20 20 LUBBOCK 69 94 69 93 68 / 30 20 20 20 20 DENVER CITY 69 95 68 94 66 / 30 20 20 30 30 BROWNFIELD 70 95 68 93 66 / 30 20 20 20 20 CHILDRESS 68 94 72 93 71 / 30 10 10 10 10 SPUR 70 94 70 93 69 / 30 10 20 20 20 ASPERMONT 73 95 74 95 71 / 20 10 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 14/29
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
348 PM CDT WED JUN 13 2012 .SHORT TERM... WE HAD ISOLATED WEAK CONVECTION EARLY TODAY BUT THIS HAS SINCE DISSIPATED. SKIES HAVE BECOME MOSTLY CLEAR TO PARTLY CLOUDY ACROSS THE CWA LIKELY IN RESPONSE TO SUBSIDENCE IN THE WAKE OF THE DEPARTING MCV ALONG THE RED RIVER VALLEY. A WEAK SURFACE...YET DISCERNIBLE...BOUNDARY STILL EXISTS OVER THE SOUTHWEST CWA PER THE KSJT WSR-88D BUT THIS FEATURE REMAINS BENIGN AT THIS TIME. LOOKING WEST...MID LEVEL RADAR ECHOES HAVE BEEN INCREASING ACROSS SOUTHWEST TX THIS AFTERNOON AHEAD OF AN APPROACHING SHORTWAVE. AS THIS SYNOPTIC SCALE ASCENT OVERSPREADS THE AREA AND SURFACE TEMPS WARM INTO THE MID/UPPER 90S...I ANTICIPATE CONVECTION DEVELOPING IN THE VICINITY OF THE CWA. CONFIDENCE IS FAIRLY LOW THAT WE WILL SEE WIDESPREAD THUNDERSTORMS BUT SEVERAL VERSIONS OF THE HIRES WRF AND THE HRRR ALL AGREE IN THUNDERSTORMS FORMING OVER THE CENTRAL/EASTERN COUNTIES. A LOOK AT THE SPC MESO ANALYSIS PAGE DEPICTS SBCAPE VALUES ON THE ORDER OF 2500-3500 J/KG WITH EFFECTIVE SHEAR VALUES BETWEEN 40-50 KTS. THE QUESTION WILL BE WHETHER OR NOT THE CAP WILL GIVE WAY. THUS...WE DO HAVE A CONDITIONAL THREAT FOR SEVERE WEATHER BUT I AM PLAYING THIS RATHER CONSERVATIVE FOR NOW THINKING THAT THE CAP WILL HOLD FOR THE MOST PART AND ANY CONVECTIVE INITIATION WILL LIKELY BE DELAYED UNTIL WELL AFTER PEAK HEATING. THUS...I AM ONLY CARRYING 20 POPS FOR THE PERIOD BEGINNING AT 00Z. OVERNIGHT TEMPS WILL FALL INTO THE LOWER 70S /BUT WILL LIKELY BE LOWER IF CONVECTION DOES DEVELOP/. GENERALLY DRY AND WARM CONDITIONS ARE EXPECTED FOR THURSDAY WITH SOUTH WINDS INCREASING TO 10-20 MPH ACROSS THE CWA. HIGHS ARE EXPECTED TO BE IN THE MID/UPPER 90S. JOHNSON .LONG TERM... THURSDAY NIGHT INTO FRIDAY...THE UPPER LEVEL LOW THAT IS CURRENTLY OVER SOUTHERN CALIFORNIA TODAY WILL BE ENVELOPED BY ANOTHER LOW THAT WILL MOVE SOUTH ALONG THE CALIFORNIA COAST. THERE WILL BE AN UPPER LEVEL TROUGH OVER THE GULF COAST REGION AS WELL WHILE WEST CENTRAL TEXAS WILL BE IN BETWEEN UNDERNEATH RIDGING. FOR THIS REASON...WILL GO WITH TEMPERATURES SLIGHTLY WARMER THAN GUIDANCE FOR FRIDAY AND SATURDAY. HAVE NOT EXPANDED ANY OF THE INHERITED POPS FRIDAY AFTERNOON AND EVENING. IT STILL APPEARS THAT THE LOW WILL BE TOO FAR WEST TO DIRECTLY INFLUENCE US...AND THAT MOST OF THE CONVECTION WILL GET GOING IN THE HIGHER TERRAIN OF THE WEST TEXAS AREA...THEN MOVE SLOWLY TO THE NORTHEAST DURING THE EVENING HOURS...POSSIBLY MAKING THEIR WAY INTO OUR WESTERN TIER OF COUNTIES BEFORE DISSIPATING. THE UPPER LEVEL RIDGING EXPANDS THROUGH THE WEEKEND ACROSS TEXAS AND THE REST OF THE SOUTHWESTERN U.S. THIS WILL PUSH THE MID/UPPER LEVEL LOW BACK OUT TO THE PACIFIC...AND KEEP OUR TEMPERATURES WARMER THAN NORMAL WITH LITTLE CHANCE FOR PRECIPITATION. BY TUESDAY OF NEXT WEEK...A WEAK MID/UPPER LEVEL TROUGH DEVELOPS ACROSS THE EASTERN HALF OF TEXAS...AND LOOKS TO DRIFT SLOWLY WEST/SOUTHWEST ACROSS THE SOUTHERN HALF OF THE STATE. THIS COULD RESULT IN SOME LOWERED TEMPERATURES...AND THE GFS/ECMWF ALSO TRY TO SHOW SOME SHRA/TSRA DEVELOPING ACROSS OUR SOUTHEASTERN COUNTIES. WILL HOLD OFF ON INTRODUCING ANY WX AT THIS TIME...BUT IT WILL BE WORTH WATCHING. 20 && .PRELIMINARY POINT TEMPS/POPS... ABILENE 72 93 72 94 71 / 20 10 10 10 10 SAN ANGELO 73 98 73 98 71 / 20 10 10 10 10 JUNCTION 74 98 73 94 72 / 20 10 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
1249 PM CDT WED JUN 13 2012 .UPDATE... 18Z AVIATION DISCUSSION IS BELOW. DIFFICULT FORECAST FOR THIS AFTERNOON AS NONE OF THE MESOSCALE MODELS ARE INDICATING CONVECTION OVER THE FORECAST AREA...THE OPERATIONAL RUNS ARE... AND THE LATEST RAP RUN WEAKENS THE CAP CONSIDERABLY WHICH ALL MEAN CONDITIONS WILL NEED TO BE WATCHED. DEEP LAYER SHEAR PROFILE IS MUCH WEAKER THAN YESTERDAY WITH SURFACE WINDS VEERING TO MORE OF A SOUTHERLY DIRECTION THROUGH THE DAY AS OPPOSED TO SOUTHEASTERLY. THERE IS A WEAK SURFACE TROF OVER THE AREA WHICH MAY PROVIDE AN AREA OF SURFACE-BASED CONVERGENCE AND IF THE LATEST RAP RUNS ARE CORRECT...SBCAPE VALUES OF BETWEEN 2000-3500 J/KG MAY BE REALIZED. THESE TWO FEATURES MEAN THAT THERE IS STILL A POTENTIAL FOR SEVERE CONVECTION THIS AFTERNOON...HOWEVER CONFIDENCE IS STILL PRETTY LOW WHEN/IF ANYTHING CAN GO. WITH CAPE VALUES THIS HIGH...LARGE HAIL WILL BE THE PRIMARY THREAT ALONG WITH SOME LOCALLY HEAVY RAINFALL. WILL KEEP POPS THE WAY THEY ARE FOR NOW AND WILL EVALUATE THROUGH THE DAY TO SEE IF THERE ARE ANY AREAS SHOWING A TENDENCY FOR CONVECTIVE DEVELOPMENT AND ADJUST IF NEEDED. JORDAN && .AVIATION... MVFR CONDITIONS AT KCDS SHOULD GRADUALLY GIVE WAY TO VFR THIS AFTERNOON WITH VFR IN PLACE IN LUBBOCK. THERE DOES REMAIN A CHANCE WE COULD SEE STORMS AT BOTH TERMINALS BUT THE TIMING OF THIS POSSIBILITY IS HIGHLY UNCERTAIN AT THIS TIME AND WILL NOT INCLUDE IN THE TAFS FOR NOW. MVFR CEILINGS COULD REDEVELOP AT BOTH TERMINALS OVERNIGHT IF THERE ARE STORMS IN THE AREA AND WILL ALSO MONITOR FOR POSSIBLE INCLUSION IN LATER TAF ISSUANCES. JORDAN && .PREV DISCUSSION... /ISSUED 640 AM CDT WED JUN 13 2012/ AVIATION... OUTFLOW FROM OVERNIGHT CONVECTION WILL BRING MOIST EASTERLY WINDS ACROSS THE AREA THIS MORNING WITH THE POTENTIAL FOR AREAS OF LOW STRATUS. SAT IMAGERY AT 630 AM SHOWS EXPANDING STRATUS FIELD ACROSS THE WESTERN SOUTH PLAINS. WITH LOW CONFIDENCE THAT MVFR CEILINGS WILL IMPACT EITHER TERMINAL WE HAVE KEPT TAFS VFR FOR NOW. THIS EVENING...WE EXPECT SCATTERED TSTM ACTIVITY ACROSS ERN NM AND WRN SPLNS TO MOVE EAST TOWARD BOTH TERMINALS...WITH HIGHER CONFIDENCE THAT STORMS WILL REACH THE CENTRAL SOUTH PLAINS WE HAVE ADDED A PROB30 TO KLBB. PREV DISCUSSION... /ISSUED 410 AM CDT WED JUN 13 2012/ DISCUSSION... CONVECTIVE INITIATION AND LOCATION TODAY STILL REMAINS HIGHLY UNCERTAIN ESPECIALLY WITH CONVECTION FROM EARLY THIS MORNING STABILIZING THINGS OUT. WINDS SHOULD STILL BE ABLE TO SWING BACK AROUND TO THE SOUTHEAST BY LATER THIS MORNING WITH STRONG SURFACE DESTABILIZATION BY THE AFTERNOON. WITH THE OUTFLOW...A STRONG CAP WILL BE IN PLACE AT LEAST THROUGH THE EARLY AFTERNOON. STEEP MID LEVEL LAPSE RATES WILL CONTRIBUTE TO VERY STRONG SURFACE CAPE VALUES BETWEEN 3000 AND 4000 J/KG ON THE CAPROCK. HOWEVER...LIFT WILL BE SIGNIFICANTLY WEAKER THAN OBSERVED EARLY THIS MORNING. MID AND UPPER LEVEL FLOW WILL BE WEAKER. UPPER LEVEL LIFT WILL GENERALLY BE LESS ROBUST WITH A VERY WEAK JET MAX MOVING OVERHEAD. THE ONLY LOW LEVEL CONVERGENCE WILL BE FOUND NEAR THE MOUNTAINS IN EASTERN NEW MEXICO. WEAK HEIGHT FALLS WILL NOT MOVE INTO THE AREA UNTIL EARLY THIS EVENING. CONVECTION DOES APPEAR POSSIBLE BUT LOCATION IS EXTREMELY DIFFICULT TO DETERMINE AT THE MOMENT. THE BEST CHANCES WILL LIKELY EXIST ON THE CAPROCK THIS EVENING. BEGINNING ON THURSDAY...A TROUGH WILL AMPLIFY ACROSS THE DESERT SOUTHWEST. THIS WILL CAUSE THE UPPER FLOW OVER WEST TEXAS TO TURN SOUTHWESTERLY. HOWEVER...THIS FLOW WILL ALSO SUBSTANTIALLY WEAKEN. HEIGHT RISES ON THURSDAY WILL ALSO NOT BODE WELL FOR CONVECTION. LOW LEVEL SOUTHEASTERLY FLOW WILL CONTINUE TO KEEP MOISTURE IN THE AREA. NONETHELESS...HAVE STILL INCLUDED SLIGHT CHANCES FOR THUNDER ACROSS WESTERN AREAS ON THURSDAY. PRECIPITATION CHANCES MAY BE BETTER ON FRIDAY WHEN THE MID AND UPPER FLOW WILL INCREASE A BIT. DIFFLUENCE WILL ALSO BE SEEN ALOFT ALTHOUGH THE JET MAX WILL STILL BE WELL TO THE SOUTHWEST OF THE REGION. DETAILS ARE STILL SKETCHY FOR THE WEEKEND WITH CONVECTION POSSIBLE EACH DAY THROUGH SUNDAY. SOUTHEASTERLY FLOW WILL HELP TO KEEP LOW LEVEL MOISTURE IN THE AREA WITH AN UNSTABLE ATMOSPHERE DURING THE AFTERNOON HOURS. PRECIPITABLE WATER VALUES WILL ALSO INCREASE THROUGH THE WEEKEND BEGINNING ON FRIDAY. MODELS ALSO SHOW MID LEVEL TEMPERATURES COOLING ON SATURDAY AND SUNDAY INDICATING INCREASED INSTABILITY AND LESS CHANCE OF A CAP THESE DAYS. THINGS LOOK TO THEN DRY OUT A BIT EARLY NEXT WEEK WITH A POSSIBLE FRONTAL PASSAGE ON TUESDAY. JDV && .PRELIMINARY POINT TEMPS/POPS... FRIONA 89 64 92 63 91 / 30 30 20 20 30 TULIA 86 64 91 64 91 / 30 30 20 20 20 PLAINVIEW 85 65 91 66 91 / 30 30 20 20 20 LEVELLAND 91 67 94 66 92 / 30 30 20 20 20 LUBBOCK 89 69 93 68 92 / 30 30 20 20 20 DENVER CITY 94 70 94 69 92 / 30 30 20 20 30 BROWNFIELD 93 70 94 69 92 / 30 30 20 20 20 CHILDRESS 88 70 92 72 93 / 30 30 10 10 10 SPUR 90 69 93 69 93 / 30 30 20 20 10 ASPERMONT 93 72 95 73 95 / 20 20 10 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 99/99/99
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
402 PM CDT WED JUN 13 2012 .SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT 356 PM CDT WED JUN 13 2012 AT 3 PM...A CONVECTIVELY INDUCED VORTICITY MAXIMUM WAS MOVING THROUGH NORTH-CENTRAL IOWA AND SOUTH-CENTRAL MINNESOTA. THE LAPS INDICATES MODERATE TO STRONG 800-600 MB FRONTOGENESIS ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA. THE LATEST RAP CONTINUES TO SHOW THAT THIS FRONTOGENESIS WILL CONTINUE TO WEAKEN LATE THIS AFTERNOON. AS THIS OCCURS...EXPECT THE BAND OF SHOWERS JUST TO OUR WEST WILL CONTINUE TO WEAKEN AND DISSIPATE. THIS IS IN GOOD AGREEMENT WITH THE HRRR...EAST ARW...AND EAST NMM. FOR TONIGHT...THE 13.12Z MODELS ARE IN GOOD AGREEMENT THAT STRONG 925 TO 700 MB MOISTURE TRANSPORT WILL DEVELOP ACROSS NORTHERN AND WESTERN MINNESOTA. THIS IS IN RESPONSE TO A WARM FRONT MOVING THROUGH THIS REGION. ALL OF THE MESO MODELS AND BROADER SCALE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT A MAJORITY OF THE PRECIPITATION OVERNIGHT WILL BE WEST OF A CHARLES CITY IOWA TO DIAMOND LAKE WISCONSIN LINE. ON THURSDAY AFTERNOON AND EVENING...THE MODELS ARE SHOWING THAT THERE WILL INCREASING SHEAR ACROSS EASTERN MINNESOTA...AND NORTHERN WESTERN WISCONSIN AS A STRONG WAVE SHORT WAVE MOVES ACROSS NORTHERN MINNESOTA. BULK SHEARS CLIMB ABOVE 40 KNOTS ACROSS THE AFOREMENTIONED AREAS WHICH WILL MAKE IT FAVORABLE FOR THE DEVELOPMENT OF SUPERCELL THUNDERSTORMS. THE SIGNIFICANT TORNADO PARAMETER SUGGESTS THAT THERE WILL BE THE POTENTIAL OF TORNADOES. THE NAM/WRF WOULD SUGGEST EAST-CENTRAL MINNESOTA AND NORTHWEST WISCONSIN. MEANWHILE THE GFS INDICATES THAT THIS MAY BE A BIT FURTHER SOUTH AND IT WOULD INCLUDE SOUTHEAST MINNESOTA AND WEST- CENTRAL WISCONSIN. WHILE THE SHEAR IS GOOD...THERE IS SOME CONCERN THAT THAT DEW POINTS IN THE MODELS MAY BE A BIT TOO HIGH...AND IF THIS IS TRUE THAN THE CAPES MAY BE TOO HIGH TOO. THE TORNADO THREAT WOULD LIKELY IN THE MID TO LATE AFTERNOON...AND THEN EVOLVE INTO A WIND THREAT AS THE COLD POOLS COALESCE. BEYOND THIS TIME PERIOD...THERE IS A LOT OF UNCERTAINTY ON WHERE THE FRONT WILL BE LOCATED ACROSS THE REGION. DUE TO THIS...THERE IS LOW CONFIDENCE ON BOTH THE TEMPERATURE AND PRECIPITATION FORECAST. .LONG TERM...SATURDAY THROUGH WEDNESDAY 356 PM CDT WED JUN 13 2012 ON SATURDAY AND SATURDAY NIGHT...THE MODELS SUGGEST THAT A COLD FRONT AND UPPER LEVEL TROUGH WILL BE MOVING THROUGH THE REGION. THE BULK SHEAR WILL ONCE AGAIN CLIMB ABOVE 40 KNOTS. THIS WOULD BE CONDUCIVE FOR THE DEVELOPMENT OF SUPERCELL THUNDERSTORMS. HOWEVER THERE IS QUITE A BIT OF UNCERTAINTY ON WHEN THE COLD FRONT WILL MOVE THROUGH THE REGION AND HOW MUCH INSTABILITY WILL BE AHEAD OF IT. ON SUNDAY AND SUNDAY NIGHT...BOTH THE GEM AND ECMWF INDICATE THAT THE AREA MAY BE DRY AS HIGH PRESSURE BUILDS ACROSS THE REGION. MEANWHILE THE GFS IS SHOWING YET ANOTHER FRONT MOVING INTO THE REGION. DUE TO THIS THE ALL BLEND POPS WERE REDUCED SOME. LOOKING TOWARD THE MIDDLE OF NEXT WEEK...THERE LOOKS TO BE A PATTERN CHANGE BACK TO NORTHWEST FLOW AS A TROUGH BUILDS ACROSS THE REGION. THE GFS IS NOT AS AGGRESSIVE AS THE ECMWF. HOWEVER LOOKING WITH A MADDEN JULIAN OSCILLATION MOVING FROM PHASE 6 TO 7...THE ECMWF WOULD BE THE MOST PROBABLE OUTCOME. && .AVIATION...THROUGH 18Z THURSDAY 101 PM CDT WED JUN 13 2012 VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH MAIN FORECAST CONCERNS ON PRECIPITATION CHANCES OVERNIGHT AND THURSDAY. FOR THIS AFTERNOON...WEAK SHORTWAVE MOVING ACROSS AREA RESULTING IN ISOLATED SPRINKLES ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA. DRY AIR IN THE LOW LEVELS IS KEEPING CLOUD BASES AT OR ABOVE 8 KFT. FOR THE OVERNIGHT...BROKEN TO SCATTERED MID TO HIGH LEVEL DECK WILL PERSIST AND AS 850 MB MOISTURE TRANSPORT INCREASES TO THE WEST...SHOWERS AND THUNDERSTORMS LOOK TO DEVELOP ACROSS CENTRAL MINNESOTA. CURRENT THINKING IS THIS ACTIVITY WILL REMAIN NORTH AND WEST OF KRST/KLSE SO FOR NOW HAVE LEFT OUT OF TAFS...BUT WILL NEED TO MONITOR CLOSELY. AN INCREASINGLY TIGHTER PRESSURE GRADIENT THURSDAY MORNING / AFTERNOON WILL LEAD TO BREEZY SOUTHERLY WINDS WITH GUSTS TO AROUND 25 KTS AT KRST AND 20 KTS AT KLSE. LOOKING AHEAD...A COLD FRONT WILL APPROACH THE AREA THURSDAY EVENING...BRINGING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. && .ARX WATCHES/WARNINGS/ADVISORIES... 356 PM CDT WED JUN 13 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BOYNE LONG TERM...BOYNE AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
101 PM CDT WED JUN 13 2012 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT 325 AM CDT WED JUN 13 2012 MAIN FORECAST CONCERN DEALS WITH RAIN CHANCES TODAY THROUGH FRIDAY NIGHT. WATER VAPOR IMAGERY AND RAP ANALYSIS AT 2 AM SHOWS A DISTINCT MID-LEVEL CYCLONIC CIRCULATION MOVING EAST ACROSS CENTRAL SD. MOISTURE TRANSPORT AND ISENTROPIC LIFT AHEAD OF THE WAVE AIDING IN SHOWERS AND ISOLATED THUNDERSTORMS ACROSS EASTERN SD/NEB...INTO NORTHWEST IA. CLOSER TO HOME OVER OUR FORECAST AREA...HIGH CLOUDS FROM THE DAKOTAS WAVE STREAMING IN WITH CENTER OF HIGH PRESSURE ACROSS CENTRAL WI INTO CENTRAL LOWER MI. LIGHT WINDS AND PARTLY CLOUDY CONDITIONS HAS ALLOWED TEMPERATURES TO DIP TO 37 DEGREES AT BLACK RIVER FALLS WI...WHILE OTHER LOCATIONS RANGED FROM THE 40S TO THE LOWER 50S UNDER MORE CLOUD COVER. 13.00Z NCEP MODEL SUITE/ECMWF/GEM GENERALLY IN GOOD AGREEMENT THROUGH THE SHORT TERM PERIOD. FOR TODAY...WILL BE WATCHING THAT MID-LEVEL WAVE OVER SD MOVES INTO CENTRAL MN THROUGH THIS AFTERNOON. MODELS CONCENTRATE MAIN AXIS OF ASSOCIATED 850MB MOISTURE TRANSPORT NORTHWEST INTO MN WITH OUR AREA JUST ON THE EASTERN FRINGES. MEANWHILE...DECENT AMOUNT OF ISENTROPIC LIFT INTO THE AREA FOR MID-CLOUD/ACCAS GENERATION. KEPT SMALL CHANCES OF SHOWERS MAINLY NORTHWEST OF A LINE FROM MEDFORD AND ARCADIA WI...TO ROCHESTER AND AUSTIN MN. OTHERWISE...WITH INCREASING CLOUD COVER EXPECTED...HIGHS TODAY ARE EXPECTED TO TOP OFF IN THE LOWER TO MIDDLE 70S. TONIGHT...ANOTHER MID-LEVEL WAVE AND SURFACE CYCLOGENESIS WILL TAKE PLACE OVER NEB/SD WITH MOISTURE TRANSPORT/ISENTROPIC LIFT IMPINGING ON THE WESTERN PORTIONS OF THE FORECAST AREA. PLANNING ON ISOLATED SHOWER AND ISOLATED THUNDER //WITH INCREASING ELEVATED MUCAPE// NORTHWEST OF A MEDFORD-ARCADIA-ROCHESTER-AUSTIN LINE AGAIN IN THE EVENING...THEN INCREASING SLIGHTLY IN COVERAGE/SPREADING EAST INTO THE REST OF THE AREA AFTER MIDNIGHT AS 850MB MOISTURE TRANSPORT VECTORS BEND MORE INTO THE AREA. RAINFALL LOOKS VERY LIGHT WITH GENERALLY LESS THAN 5 HUNDREDTHS OF AN INCH EXPECTED. ON THURSDAY...LOOK FOR THE MID-LEVEL WAVE/SURFACE COLD FRONT TO MOVE INTO MN WITH INCREASING 850MB MOISTURE TRANSPORT INTO THE AREA. 0-3KM MLCAPE INCREASES INTO THE 1000-1500J/KG RANGE ALONG AND AHEAD OF THE FRONT JUST TO OUR WEST WITH RESPECTABLE 20-30KT 0-3KM BULK SHEAR. THEREFORE...EXPECTING STRONGER THUNDERSTORM ACTIVITY ALONG THE FRONT BY AFTERNOON WITH EASTERN FRINGES OF THIS ACTIVITY PERHAPS MAKING IT INTO NORTHWEST PORTIONS OF THE FORECAST AREA. FOR NOW...WILL STICK WITH 20-40 PERCENT SHOWER/THUNDERSTORM CHANCE NORTHWEST OF A SPARTA-VIROQUA-OELWEIN LINE. OTHERWISE...LOOK FOR HIGH TEMPERATURES IN THE UPPER 70S TO LOWER 80S. FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT...LOOK FOR THE COLD FRONT OVER MN TO SINK INTO THE AREA WHILE WEAKENING. MEANWHILE...MODELS SHOWING A COUPLE MID-LEVELS WAVE EJECTING NORTHEAST TOWARD/ACROSS THE AREA WITH BOUTS OF LIFT/MOISTURE TRANSPORT. BASED ON THIS SIGNAL...WILL GO WITH 30-50 SHOWER/THUNDERSTORM CHANCES FOR NOW FOR THIS PERIOD. .LONG TERM...SATURDAY THROUGH TUESDAY 325 AM CDT WED JUN 13 2012 13.00Z GFS/ECMWF SHOWING SOUTHWEST FLOW ALOFT INTO THE AREA THROUGH THE PERIOD AS HIGH PRESSURE ANCHORS IN ACROSS THE EASTERN CONUS AND A TROUGH SLOWLY MAKES ITS WAY ACROSS THE INTERMOUNTAIN WEST INTO THE PLAINS. SIGNAL AGREEMENT BETWEEN THE MODELS SEEMS TO BE GETTING STRONGER FOR PERIODIC SHOWER/THUNDERSTORM CHANCES THROUGH THE WEEKEND. BOTH MODELS THEN BRING IN A DEEPER TROUGH/STRONGER SURFACE COLD FRONT INTO THE AREA MONDAY THROUGH TUESDAY FOR CONTINUED SHOWER/THUNDERSTORM CHANCES. && .AVIATION...THROUGH 18Z THURSDAY 101 PM CDT WED JUN 13 2012 VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH MAIN FORECAST CONCERNS ON PRECIPITATION CHANCES OVERNIGHT AND THURSDAY. FOR THIS AFTERNOON...WEAK SHORTWAVE MOVING ACROSS AREA RESULTING IN ISOLATED SPRINKLES ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA. DRY AIR IN THE LOW LEVELS IS KEEPING CLOUD BASES AT OR ABOVE 8 KFT. FOR THE OVERNIGHT...BROKEN TO SCATTERED MID TO HIGH LEVEL DECK WILL PERSIST AND AS 850 MB MOISTURE TRANSPORT INCREASES TO THE WEST...SHOWERS AND THUNDERSTORMS LOOK TO DEVELOP ACROSS CENTRAL MINNESOTA. CURRENT THINKING IS THIS ACTIVITY WILL REMAIN NORTH AND WEST OF KRST/KLSE SO FOR NOW HAVE LEFT OUT OF TAFS...BUT WILL NEED TO MONITOR CLOSELY. AN INCREASINGLY TIGHTER PRESSURE GRADIENT THURSDAY MORNING / AFTERNOON WILL LEAD TO BREEZY SOUTHERLY WINDS WITH GUSTS TO AROUND 25 KTS AT KRST AND 20 KTS AT KLSE. LOOKING AHEAD...A COLD FRONT WILL APPROACH THE AREA THURSDAY EVENING...BRINGING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. && .ARX WATCHES/WARNINGS/ADVISORIES... 325 AM CDT WED JUN 13 2012 WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...ZT