Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/02/13


AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 AM MST FRI MAY 31 2013 .SYNOPSIS...HIGH PRESSURE ALOFT WILL BRING DRY CONDITIONS WITH WELL ABOVE NORMAL TEMPERATURES THROUGH THE MIDDLE OF NEXT WEEK. && .DISCUSSION...THE SHALLOW MOISTURE THAT WAS AROUND YESTERDAY MORNING MADE A RETURN LAST NIGHT INTO THIS MORNING...WITH SURFACE DEWPOINTS HIGHER THEN YESTERDAY. ALMOST MONSOON LIKE FROM TUCSON WEST. THIS MOISTURE ALSO BROUGHT A HAZY SKY TO THE AREA THIS MORNING ALONG WITH WARMER OVERNIGHT LOW TEMPERATURES. THE MAIN FORECAST CHALLENGE OF THE DAY SURROUNDS THE THIRD ATTEMPT THIS MONTH FOR HITTING 100 DEGREES AT THE TUCSON AIRPORT FOR THE FIRST TIME IN 2013. 850-700 MB THICKNESS VALUES ON THE MORNING SOUNDING WERE UP VERSUS YESTERDAY AND IF YOU ADD THAT INCREASE TO YESTERDAY AFTERNOON 850-700 MB TKNS VALUE...99 IS PRETTY CERTAIN WITH AN OUTSIDE CHANCE FOR 100. BASED ON 850-700 MB THICKNESS VALUES FOR THIS AFTERNOON 12Z NAM/12Z GFS GOING 98 OR 99...00Z ECMWF/12Z UKMET/12Z CANADIAN INDICATING 100. 14Z HRRR/15Z RAP GOING WITH 99. HOW MUCH OF THIS SHALLOW MOISTURE MIXES OUT WILL ALSO BE A KEY TODAY. OTHERWISE ACROSS SE AZ...HIGHS WILL BE 1-4 DEGREES ABOVE NORMAL. MAY SEE SOME FLAT CU AROUND THIS AFTERNOON ESPECIALLY EAST OF TUCSON AND UP IN THE WHITES. && .AVIATION...SKC THRU SATURDAY MORNING OR 01/15Z. SURFACE WIND THIS AFTERNOON AND EARLY THIS EVENING WLY/NWLY 10-18 KTS WITH GUSTS OF 20-25 KTS... STRONGEST WIND EAST OF KTUS. OTHERWISE...SURFACE WIND LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME TEMPERATURES WILL PREVAIL INTO THE MIDDLE OF NEXT WEEK. DAYTIME MINIMUM RELATIVE HUMIDITIES WILL GENERALLY BE IN THE SINGLE DIGITS TO LOWER TEENS WITH FAIR TO POOR OVERNIGHT RECOVERIES. NORMAL DIURNAL WIND TRENDS WILL OCCUR...WITH OCCASIONAL GUSTS DURING THE AFTERNOON HOURS DUE TO STRONG DAYTIME HEATING. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
845 PM EDT SAT JUN 1 2013 .UPDATE (TONIGHT AND SUNDAY)... 00Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW AN AMPLIFIED UPPER PATTERN ACROSS THE CONUS THIS EVENING. SHARP TROUGHING IS NOW EJECTING EASTWARD FROM THE CENTRAL PLAINS TOWARD THE GREAT LAKES/APPALACHIANS. IN RESPONSE...LONGWAVE RIDGING IS BEGINNING TO GIVE UP ITS HOLD ON THE MID-ATLANTIC AND NORTHEASTERN STATES. OUR REGION REMAIN IN A WEAK OR ILL-DEFINED UPPER LEVEL PATTERN. WV IMAGERY CONTINUES TO SHOW A SHARP MID/UPPER LEVEL MOISTURE SEPARATING DRIER AIR ALOFT OVER THE NORTHERN FL PENINSULA FROM DEEP MOISTURE OVER THE SOUTH. AT THE SURFACE...SUBTROPICAL RIDGE AXIS IS LOCATED TO OUR NORTH OFF THE GA/CAROLINA COASTLINE...BUT HAS WEAKENED ITS INFLUENCE ON THE REGION OVER THE PAST 24 HOURS. THE WEAKER GRADIENT ALLOWED A WELL-DEFINED SEA-BREEZE TO BECOME ESTABLISHED THIS AFTERNOON WHICH COMBINED WITH WEAK EASTERLY SYNOPTIC FLOW TO FOCUS THE DIURNAL CONVECTION TOWARD THE WEST COAST OF THE PENINSULA DURING THE AFTERNOON/EVENING. REST OF TONIGHT...THE COMBINATION OF THE LOSS OF DIURNAL HEATING AND COLUMN OVERTURNING DUE TO ONGOING OR PAST CONVECTION SHOULD SLOWLY ALLOW THE REMAIN SHOWERS/STORMS TO FADE INTO THE LATER EVENING HOURS. LOCAL HI-RES CONVECTION MODELS SHOW MUCH OF THE ACTIVITY GONE BY MIDNIGHT FOLLOWED BY A GENERALLY DRY REST OF THE OVERNIGHT. PREVIOUS FORECAST HAD THIS TREND IN THE RAIN CHANCES AND SEE LITTLE REASON FOR SIGNIFICANT CHANGES. SUNDAY... LOCAL GRADIENT ACROSS THE PENINSULA LOOKS TO SLACKEN EVEN FURTHER FOR THE SECOND HALF OF THE WEEKEND. MORNING WILL START OUT QUIET...WARM AND MUGGY WITH A MIX OF SUN AND CLOUDS. GOOD MODEL AGREEMENT THAT WE WILL SEE WELL-DEFINED WEST AND EAST COAST SEA-BREEZE DEVELOPMENT...WITH NEITHER BECOMING DOMINANT. LOCAL HI-RES WRF-ARW MODELS ALL SHOW A SEA-BREEZE COLLISION OVER THE INTERIOR PENINSULA LATE SUNDAY AFTERNOON. INITIAL SHOWER/STORM DEVELOPMENT WILL BE NEAR THE COAST DURING THE EARLY AFTERNOON...BUT THEN PUSH INLAND AND BECOME MORE ROBUST OVER PLACES LIKE POLK/HIGHLANDS/DESOTO/HARDEE COUNTIES WHERE LOW LEVEL CONVERGENCE WILL BE MAXIMIZED BY THE COLLIDING BOUNDARIES. ALTHOUGH BEACHGOERS MAY SEE A BRIEF SHOWER OR STORM EARLY...IF THIS SCENARIO DOES INDEED OCCUR...CONDITIONS ARE LIKELY TO CLEAR NEAR THE BEACHES FOR MUCH OF THE AFTERNOON/EARLY EVENING AS THE SEA-BREEZE MOVES INLAND AND TAKES THE STORMS WITH IT. && .AVIATION... TSRA/SHRA END AROUND 03Z. MAINLY MID LEVEL BKN DECK OVERNIGHT WITH SOME LOWER CLOUDS BUT ANTICIPATE BKN MVFR ONLY AT LAL/PGD. SLIGHTLY LIGHTER WINDS IN THE SOUTH MAY RESULT IN LIMITED BR AT PGD/FMY/RSW LATER TONIGHT. DEEPER MOISTURE ADVECTING ACROSS THE AREA FROM THE SOUTH SUN WILL SUPPORT LATE MORNING SHRA AND AFTERNOON TSRA. && .MARINE... HIGH PRESSURE WILL REMAIN THE DOMINANT WEATHER FEATURE THROUGH THE WEEKEND. A DEVELOPING AREA OF LOW PRESSURE IN THE SOUTHWEST GULF OF MEXICO WILL MOVE NORTHEAST EARLY NEXT WEEK...WITH INCREASING WINDS AND SEAS. BY MONDAY NIGHT...MARINE CONDITIONS COULD DETERIORATE TO SMALL CRAFT ADVISORY LEVELS...PARTICULARLY OVER THE SOUTHERN WATERS. && .PRELIMINARY POINT TEMPS/POPS... TPA 75 89 75 86 / 30 50 30 60 FMY 73 89 74 85 / 30 60 20 60 GIF 73 91 72 89 / 30 60 40 60 SRQ 73 87 74 86 / 30 40 20 60 BKV 71 90 71 88 / 30 40 30 50 SPG 76 88 76 86 / 30 40 20 60 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE...MROCZKA AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS MIAMI FL
1016 AM EDT FRI MAY 31 2013 .UPDATE... NO CHANGES WERE REQUIRED TO THE CURRENT FORECAST. THE 12Z SOUNDING INDICATED THAT TROPICAL MOISTURE CONTINUES ACROSS THE REGION WITH A PWAT JUST OVER TWO INCHES WHICH IS ABOUT 20 PERCENT ABOVE THE NORMAL PWAT FOR THIS DATE. THE FORECAST FOR THE REST OF TODAY IS IN LINE WITH THE LATEST MESO-SCALE MODEL GUIDANCE INDICATING THAT THE MOST ACTIVE PERIOD FOR SHOWERS/THUNDERSTORMS WILL BE THIS AFTERNOON WITH MOST OF THE COVERAGE EXPECTED ACROSS THE WESTERN PORTIONS OF THE PENINSULA AFTER 18Z THIS AFTERNOON. THE GUIDANCE ALSO CONTINUES TO INDICATE THAT THE PRESSURE GRADIENT AND RESULTANT STRONG WINDS ACROSS THE ATLANTIC WATERS WILL CONTINUE TO SLOWLY DECREASE AS THE DAY PROGRESSES WITH THE SMALL CRAFT ADVISORY FOR THE ATLANTIC WATERS AND BISCAYNE BAY EXPIRING AFTER 00Z THIS EVENING...WHICH IS IN LINE WITH CURRENT OBSERVATION TRENDS. 60 && .PREV DISCUSSION... /ISSUED 658 AM EDT FRI MAY 31 2013/ AVIATION... A BERMUDA CONTINUES TO CONTROL THE WEATHER PATTERN OVER SOUTH FLORIDA FOR AT LEAST ANOTHER DAY OR TWO. THIS WILL KEEP EAST TO SOUTHEASTERLY WINDS IN THE FORECAST THROUGH THE TAF PERIOD. IT WILL ALSO KEEP SHOWERS IN THEM AS WELL. SOME MODELS ARE SUGGESTING THAT THE PRECIPITATION WILL MOVE OFF TO THE WESTERN SIDE OF THE STATE, AND BE ENHANCED AS IT REACHES THE GULF COAST. THUS, HAVE TAKEN MENTION OF RAIN OUT FOR NOW AFTER 19Z, EXCEPT AT KAPF, WHERE IT IS QUIET NOW AND ADDED RAIN AFTER 18Z. THERE IS ALSO A CHANCE FOR THUNDERSTORMS THIS AFTERNOON ALONG THE GULF COAST. WITH ANY OF THE HEAVIER SHOWERS, MVFR AND IFR WILL BE POSSIBLE FOR BRIEF PERIOD OF TIME. PREV DISCUSSION... /ISSUED 249 AM EDT FRI MAY 31 2013/ SHORT TERM (TODAY THROUGH SUNDAY)... MODELS CONTINUE TO HAVE ISSUES WITH THE SURFACE PRESSURE PATTERNS BUT ARE IN GOOD AGREEMENT WITH THE MID LEVELS. A WEAK PRESSURE PATTERN ALOFT IS FORECAST TO CONTINUE WITH ABUNDANT DEEP LAYER MOISTURE IN PLACE WITH PWAT VALUES HOVERING AROUND TWO INCHES. AT THE SURFACE, THE GFS HAS TRENDED WITH THE ECMWF IN CONTINUING THE HIGH PRESSURE OVER THE SOUTHEAST STATES BUT SHIFTING IT TO THE EAST OVER THE WEEKEND AS A WEAK COLD FRONT MOVES INTO THE SOUTHEAST STATES. THIS WILL RESULT IN RETAINING A STRONG SOUTHEAST LOW LEVEL FLOW TODAY AND THEN DIMINISHING SATURDAY AND SUNDAY. THE NAM SEEMS TO BE SUFFERING FROM SOME OF ITS MESOSCALE BIASING AS IT DEVELOPS A INVERTED TROUGH ALONG THE WEST COAST OF THE PENINSULA VEERING THE LOW LEVEL FLOW TO THE SOUTH ACROSS OUR REGION. THE GFS AND ECMWF RETAIN THE THE SOUTHEAST FLOW AND THIS SEEMS MORE REASONABLE. SO THE HIGH RISK OF RIP CURRENTS WILL CONTINUE TODAY AND SATURDAY WITH A LESSER THREAT ON SUNDAY BUT LIKELY MAINTAINING A MODERATE RISK. THE MAV AND MET GUIDANCE IS NEARLY IN PERFECT AGREEMENT WITH LIKELY POPS TODAY AND SUNDAY WITH A LESSER CHANCE ON SUNDAY. HOWEVER, RADAR SIGNATURES ARE NOT TERRIBLY IMPRESSIVE CURRENTLY AND THE SHORT TERM HIGH RESOLUTION MODELS ARE NOT IN AGREEMENT ON THE EVOLUTION TOWARDS SUNRISE INTO THE EARLY MORNING. BOTH THE HRRR AND THE WRF HAVE INITIALIZED WELL IN DEPICTING FAST MOVING SHOWERS OVER THE ATLANTIC AND MOVING ONSHORE ALONG THE SOUTHEAST COAST. THE WRF THEN FLARES UP CONVECTION ALONG THE NORTHERN BROWARD AND PALM BEACH COASTS AROUND 09Z AND DEVELOPS HEAVY SHOWERS OVER MUCH OF EASTERN PALM BEACH COUNTY. THE HRRR ON THE OTHER HAND KEEPS THE SHOWERS MINIMAL AND THEN CLEARS OUT THE EAST COAST DURING THE MORNING WITH ADDITIONAL ACTIVITY DEVELOPING OVER THE WESTERN HALF IN THE LATE MORNING AS THEY MOVE TOWARDS COASTAL COLLIER COUNTY. GIVEN THE STATE OF THE CURRENT ATMOSPHERE AND THE HIGHER RELIABILITY OF THE HRRR, WILL UNDERCUT THE POPS BY AROUND ONE CATEGORY FROM GUIDANCE. LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)... THE GFS AND ECMWF ARE BOTH IN GOOD AGREEMENT IN THE EXTENDED PERIOD IN MAINTAINING A MOIST AND UNSTABLE ENVIRONMENT OVER SOUTH FLORIDA WITH WEAK PRESSURE PATTERNS BOTH AT THE SURFACE AND ALOFT. THIS WILL RESULT IN A MORE TYPICAL SEA BREEZE DRIVEN CONVECTION PATTERN DURING THE AFTERNOONS AND EVENINGS WITH SLOW STORM MOTION. AVIATION... ATLANTIC SHOWERS WILL CONTINUE MOVE ONSHORE THROUGH THE MORNING ALONG THE EAST COAST AND THEN TRANSITION TOWARDS KAPF DURING THE AFTERNOON. THERE COULD BE A FEW THUNDERSTORMS ALONG THE WEST COAST THIS AFTERNOON BUT COVERAGE DOES NOT WARRANT MENTION IN THE TAF AT THIS TIME. EAST WIND CONTINUES TO BE MODERATE THIS MORNING BUT THE GRADIENT WILL BEGIN TO RELAX THIS AFTERNOON BUT STILL EXPECTED TO BE STRONG ENOUGH TO INHIBIT SEA BREEZE DEVELOPMENT ALONG THE COLLIER COUNTY COAST. MARINE... MARINE CONDITIONS WILL CONTINUE TO BE ROUGH ESPECIALLY ALONG THE ATLANTIC SIDE WITH SCA IN EFFECT. THE SCA WILL BE EXTENDED INTO THIS AFTERNOON WITH THESE CONDITIONS SLOWLY BEGINNING TO SUBSIDE OVER THE WEEKEND AS THE HIGH PRESSURE SHIFTS TO THE EAST AND THE GRADIENT WEAKENS. FIRE WEATHER... AMPLE TROPICAL MOISTURE SO NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 83 74 85 73 / 50 30 60 30 FORT LAUDERDALE 87 77 88 75 / 50 40 60 40 MIAMI 86 75 89 76 / 50 40 60 40 NAPLES 86 75 84 75 / 60 30 60 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...RIP CURRENT RISK UNTIL 6 PM EDT THIS EVENING FOR COASTAL BROWARD- COASTAL MIAMI DADE-COASTAL PALM BEACH. AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR BISCAYNE BAY-COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...60/BD AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS MIAMI FL
658 AM EDT FRI MAY 31 2013 .AVIATION... A BERMUDA CONTINUES TO CONTROL THE WEATHER PATTERN OVER SOUTH FLORIDA FOR AT LEAST ANOTHER DAY OR TWO. THIS WILL KEEP EAST TO SOUTHEASTERLY WINDS IN THE FORECAST THROUGH THE TAF PERIOD. IT WILL ALSO KEEP SHOWERS IN THEM AS WELL. SOME MODELS ARE SUGGESTING THAT THE PRECIPITATION WILL MOVE OFF TO THE WESTERN SIDE OF THE STATE, AND BE ENHANCED AS IT REACHES THE GULF COAST. THUS, HAVE TAKEN MENTION OF RAIN OUT FOR NOW AFTER 19Z, EXCEPT AT KAPF, WHERE IT IS QUIET NOW AND ADDED RAIN AFTER 18Z. THERE IS ALSO A CHANCE FOR THUNDERSTORMS THIS AFTERNOON ALONG THE GULF COAST. WITH ANY OF THE HEAVIER SHOWERS, MVFR AND IFR WILL BE POSSIBLE FOR BRIEF PERIOD OF TIME. && .PREV DISCUSSION... /ISSUED 249 AM EDT FRI MAY 31 2013/ SHORT TERM (TODAY THROUGH SUNDAY)... MODELS CONTINUE TO HAVE ISSUES WITH THE SURFACE PRESSURE PATTERNS BUT ARE IN GOOD AGREEMENT WITH THE MID LEVELS. A WEAK PRESSURE PATTERN ALOFT IS FORECAST TO CONTINUE WITH ABUNDANT DEEP LAYER MOISTURE IN PLACE WITH PWAT VALUES HOVERING AROUND TWO INCHES. AT THE SURFACE, THE GFS HAS TRENDED WITH THE ECMWF IN CONTINUING THE HIGH PRESSURE OVER THE SOUTHEAST STATES BUT SHIFTING IT TO THE EAST OVER THE WEEKEND AS A WEAK COLD FRONT MOVES INTO THE SOUTHEAST STATES. THIS WILL RESULT IN RETAINING A STRONG SOUTHEAST LOW LEVEL FLOW TODAY AND THEN DIMINISHING SATURDAY AND SUNDAY. THE NAM SEEMS TO BE SUFFERING FROM SOME OF ITS MESOSCALE BIASING AS IT DEVELOPS A INVERTED TROUGH ALONG THE WEST COAST OF THE PENINSULA VEERING THE LOW LEVEL FLOW TO THE SOUTH ACROSS OUR REGION. THE GFS AND ECMWF RETAIN THE THE SOUTHEAST FLOW AND THIS SEEMS MORE REASONABLE. SO THE HIGH RISK OF RIP CURRENTS WILL CONTINUE TODAY AND SATURDAY WITH A LESSER THREAT ON SUNDAY BUT LIKELY MAINTAINING A MODERATE RISK. THE MAV AND MET GUIDANCE IS NEARLY IN PERFECT AGREEMENT WITH LIKELY POPS TODAY AND SUNDAY WITH A LESSER CHANCE ON SUNDAY. HOWEVER, RADAR SIGNATURES ARE NOT TERRIBLY IMPRESSIVE CURRENTLY AND THE SHORT TERM HIGH RESOLUTION MODELS ARE NOT IN AGREEMENT ON THE EVOLUTION TOWARDS SUNRISE INTO THE EARLY MORNING. BOTH THE HRRR AND THE WRF HAVE INITIALIZED WELL IN DEPICTING FAST MOVING SHOWERS OVER THE ATLANTIC AND MOVING ONSHORE ALONG THE SOUTHEAST COAST. THE WRF THEN FLARES UP CONVECTION ALONG THE NORTHERN BROWARD AND PALM BEACH COASTS AROUND 09Z AND DEVELOPS HEAVY SHOWERS OVER MUCH OF EASTERN PALM BEACH COUNTY. THE HRRR ON THE OTHER HAND KEEPS THE SHOWERS MINIMAL AND THEN CLEARS OUT THE EAST COAST DURING THE MORNING WITH ADDITIONAL ACTIVITY DEVELOPING OVER THE WESTERN HALF IN THE LATE MORNING AS THEY MOVE TOWARDS COASTAL COLLIER COUNTY. GIVEN THE STATE OF THE CURRENT ATMOSPHERE AND THE HIGHER RELIABILITY OF THE HRRR, WILL UNDERCUT THE POPS BY AROUND ONE CATEGORY FROM GUIDANCE. LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)... THE GFS AND ECMWF ARE BOTH IN GOOD AGREEMENT IN THE EXTENDED PERIOD IN MAINTAINING A MOIST AND UNSTABLE ENVIRONMENT OVER SOUTH FLORIDA WITH WEAK PRESSURE PATTERNS BOTH AT THE SURFACE AND ALOFT. THIS WILL RESULT IN A MORE TYPICAL SEA BREEZE DRIVEN CONVECTION PATTERN DURING THE AFTERNOONS AND EVENINGS WITH SLOW STORM MOTION. AVIATION... ATLANTIC SHOWERS WILL CONTINUE MOVE ONSHORE THROUGH THE MORNING ALONG THE EAST COAST AND THEN TRANSITION TOWARDS KAPF DURING THE AFTERNOON. THERE COULD BE A FEW THUNDERSTORMS ALONG THE WEST COAST THIS AFTERNOON BUT COVERAGE DOES NOT WARRANT MENTION IN THE TAF AT THIS TIME. EAST WIND CONTINUES TO BE MODERATE THIS MORNING BUT THE GRADIENT WILL BEGIN TO RELAX THIS AFTERNOON BUT STILL EXPECTED TO BE STRONG ENOUGH TO INHIBIT SEA BREEZE DEVELOPMENT ALONG THE COLLIER COUNTY COAST. MARINE... MARINE CONDITIONS WILL CONTINUE TO BE ROUGH ESPECIALLY ALONG THE ATLANTIC SIDE WITH SCA IN EFFECT. THE SCA WILL BE EXTENDED INTO THIS AFTERNOON WITH THESE CONDITIONS SLOWLY BEGINNING TO SUBSIDE OVER THE WEEKEND AS THE HIGH PRESSURE SHIFTS TO THE EAST AND THE GRADIENT WEAKENS. FIRE WEATHER... AMPLE TROPICAL MOISTURE SO NO PROBLEMS OR CONCERNS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 83 74 85 73 / 50 30 60 30 FORT LAUDERDALE 87 77 88 75 / 50 40 60 40 MIAMI 86 75 89 76 / 50 40 60 40 NAPLES 86 75 84 75 / 60 30 60 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...RIP CURRENT RISK UNTIL 6 PM EDT THIS EVENING FOR COASTAL BROWARD- COASTAL MIAMI DADE-COASTAL PALM BEACH. AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR BISCAYNE BAY-COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
249 AM EDT FRI MAY 31 2013 .SHORT TERM (TODAY THROUGH SUNDAY)... MODELS CONTINUE TO HAVE ISSUES WITH THE SURFACE PRESSURE PATTERNS BUT ARE IN GOOD AGREEMENT WITH THE MID LEVELS. A WEAK PRESSURE PATTERN ALOFT IS FORECAST TO CONTINUE WITH ABUNDANT DEEP LAYER MOISTURE IN PLACE WITH PWAT VALUES HOVERING AROUND TWO INCHES. AT THE SURFACE, THE GFS HAS TRENDED WITH THE ECMWF IN CONTINUING THE HIGH PRESSURE OVER THE SOUTHEAST STATES BUT SHIFTING IT TO THE EAST OVER THE WEEKEND AS A WEAK COLD FRONT MOVES INTO THE SOUTHEAST STATES. THIS WILL RESULT IN RETAINING A STRONG SOUTHEAST LOW LEVEL FLOW TODAY AND THEN DIMINISHING SATURDAY AND SUNDAY. THE NAM SEEMS TO BE SUFFERING FROM SOME OF ITS MESOSCALE BIASING AS IT DEVELOPS A INVERTED TROUGH ALONG THE WEST COAST OF THE PENINSULA VEERING THE LOW LEVEL FLOW TO THE SOUTH ACROSS OUR REGION. THE GFS AND ECMWF RETAIN THE THE SOUTHEAST FLOW AND THIS SEEMS MORE REASONABLE. SO THE HIGH RISK OF RIP CURRENTS WILL CONTINUE TODAY AND SATURDAY WITH A LESSER THREAT ON SUNDAY BUT LIKELY MAINTAINING A MODERATE RISK. THE MAV AND MET GUIDANCE IS NEARLY IN PERFECT AGREEMENT WITH LIKELY POPS TODAY AND SUNDAY WITH A LESSER CHANCE ON SUNDAY. HOWEVER, RADAR SIGNATURES ARE NOT TERRIBLY IMPRESSIVE CURRENTLY AND THE SHORT TERM HIGH RESOLUTION MODELS ARE NOT IN AGREEMENT ON THE EVOLUTION TOWARDS SUNRISE INTO THE EARLY MORNING. BOTH THE HRRR AND THE WRF HAVE INITIALIZED WELL IN DEPICTING FAST MOVING SHOWERS OVER THE ATLANTIC AND MOVING ONSHORE ALONG THE SOUTHEAST COAST. THE WRF THEN FLARES UP CONVECTION ALONG THE NORTHERN BROWARD AND PALM BEACH COASTS AROUND 09Z AND DEVELOPS HEAVY SHOWERS OVER MUCH OF EASTERN PALM BEACH COUNTY. THE HRRR ON THE OTHER HAND KEEPS THE SHOWERS MINIMAL AND THEN CLEARS OUT THE EAST COAST DURING THE MORNING WITH ADDITIONAL ACTIVITY DEVELOPING OVER THE WESTERN HALF IN THE LATE MORNING AS THEY MOVE TOWARDS COASTAL COLLIER COUNTY. GIVEN THE STATE OF THE CURRENT ATMOSPHERE AND THE HIGHER RELIABILITY OF THE HRRR, WILL UNDERCUT THE POPS BY AROUND ONE CATEGORY FROM GUIDANCE. .LONG TERM (SUNDAY NIGHT THROUGH THURSDAY)... THE GFS AND ECMWF ARE BOTH IN GOOD AGREEMENT IN THE EXTENDED PERIOD IN MAINTAINING A MOIST AND UNSTABLE ENVIRONMENT OVER SOUTH FLORIDA WITH WEAK PRESSURE PATTERNS BOTH AT THE SURFACE AND ALOFT. THIS WILL RESULT IN A MORE TYPICAL SEA BREEZE DRIVEN CONVECTION PATTERN DURING THE AFTERNOONS AND EVENINGS WITH SLOW STORM MOTION. && .AVIATION... ATLANTIC SHOWERS WILL CONTINUE MOVE ONSHORE THROUGH THE MORNING ALONG THE EAST COAST AND THEN TRANSITION TOWARDS KAPF DURING THE AFTERNOON. THERE COULD BE A FEW THUNDERSTORMS ALONG THE WEST COAST THIS AFTERNOON BUT COVERAGE DOES NOT WARRANT MENTION IN THE TAF AT THIS TIME. EAST WIND CONTINUES TO BE MODERATE THIS MORNING BUT THE GRADIENT WILL BEGIN TO RELAX THIS AFTERNOON BUT STILL EXPECTED TO BE STRONG ENOUGH TO INHIBIT SEA BREEZE DEVELOPMENT ALONG THE COLLIER COUNTY COAST. && .MARINE... MARINE CONDITIONS WILL CONTINUE TO BE ROUGH ESPECIALLY ALONG THE ATLANTIC SIDE WITH SCA IN EFFECT. THE SCA WILL BE EXTENDED INTO THIS AFTERNOON WITH THESE CONDITIONS SLOWLY BEGINNING TO SUBSIDE OVER THE WEEKEND AS THE HIGH PRESSURE SHIFTS TO THE EAST AND THE GRADIENT WEAKENS. && .FIRE WEATHER... AMPLE TROPICAL MOISTURE SO NO PROBLEMS OR CONCERNS. .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 83 74 85 73 / 50 30 60 30 FORT LAUDERDALE 87 77 88 75 / 50 40 60 40 MIAMI 86 75 89 76 / 50 40 60 40 NAPLES 86 75 84 75 / 60 30 60 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...RIP CURRENT RISK THROUGH THIS AFTERNOON FOR COASTAL BROWARD- COASTAL MIAMI DADE-COASTAL PALM BEACH. AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR BISCAYNE BAY-COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20 NM TO 60 NM. GM...NONE. && $$ DISCUSSION/MARINE/FIRE...30/KOB AVIATION/RADAR...13/SI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
950 PM CDT SAT JUN 1 2013 .DISCUSSION... 308 PM CDT CONVETIVE TRENDS ARE THE MAIN FORECAST ISSUE THIS AFTERNOON. WILL MAINTAIN FLASH FLOOD WATCH ACROSS SOUTHERN TIER OF COUNTIES THROUGH ITS 00Z EXPIRATION. SURFACE LOW PRESSURE WAS CENTERED OVER CENTRAL WI AT MID AFTERNOON...WITH A COLD FRONT EXTENDING SOUTH THROUGH THE MISSISSIPPI RIVER VALLEY THEN SOUTHWEST ACROSS MISSOURI. DESPITE CONSIDERABLE CLOUD COVER NORTHWEST/WEST CENTRAL IL HAS DESTABILIZED AS EXPECTED THIS AFTERNOON...WITH SCATTERED SHRA/TSRA DEVELOPING ACROSS THE UIN-PIA-PNT AT 19Z. SPC RAP MESOANALYSIS GUIDANCE INDICATES AN AXIS OF 500-1000 J/KG AND GENERALLY CONVERGENT LOW LEVEL FLOW IN THAT REGION AHEAD OF THE SFC COLD FRONT...AND EXPECT THAT THIS ACTIVITY WILL CONTINUE TO DEVELOP AND SPREAD NORTHEAST OVER THE NEXT SEVERAL HOURS AIDED BY LARGE SCALE ASCENT ASSOCIATED WITH SHORT WAVE TROUGH PROPAGATING ACROSS IA/MO PER GOES WATER VAPOR IMAGERY. SUCCESSIVE RUNS OF THE HRRR HAVE MAINTAINED THE IDEA OF SCATTERED STORMS/SMALL CLUSTERS LIFTING NORTHEAST THROUGH THE CHICAGO METRO AREA THROUGH 23-01Z OR SO...BEFORE DIURNAL DECREASE IN INSTABILITY WITH SUNSET RESULTS IN DECREASE IN COVERAGE THIS EVENING. WHILE WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED...WITH EFFECTIVE BULK SHEAR APPROACHING 30 KT AND DRIER AIR ALOFT...MAINLY WEST WHERE A DCAPE AXIS OF 600-800 J/KG IS ANALYZED...WE COULD SEE A FEW OF THE STRONGEST CELLS PRODUCE A LITTLE HAIL OR WIND DURING THE REMAINDER OF THE AFTERNOON HOURS. ORGANIZED HEAVY RAINFALL SEEMS A FAIRLY LOW PROBABILITY AT THIS POINT...THOUGH ANALYSIS/GUIDANCE CONTINUES TO DEPICT PWATS NEAR 1.5 INCHES...BETTER LOW LEVEL MOISTURE TRANSPORT AND SLIGHTLY SLOWER STORM PROPAGATION POTENTIAL ACROSS THE SOUTHEASTERN COUNTIES OF THE CWA. SINCE A FLASH FLOOD WATCH IS ALREADY IN PLACE THERE...AND WITH THESE AREAS HAVING RECEIVED BETWEEN 2-3 INCHES OF RAINFALL IN YESTERDAY/LAST NIGHTS MCS/S...ILL ALLOW THE WATCH TO RUN THROUGH ITS 00Z EXPIRATION. COLD FRONT AND MID-LEVEL TROUGH AXIS PUSH ACROSS THE CWA THIS EVENING...WITH DRIER AIR AND HEIGHT RISES SPREADING IN FROM THE WEST OVERNIGHT. WEAKER SECONDARY FRONT TRAILS ACROSS THE AREA SUNDAY MORNING HOWEVER...WITH MOST GUIDANCE RUNS INDICATING THE POTENTIAL FOR A FEW SPOTTY SHOWERS MAINLY ACROSS EAST/SOUTHEAST PARTS OF THE FORECAST AREA. BEYOND THAT...SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA LATER SUNDAY THROUGH MONDAY MAKING FOR A COUPLE OF DAYS OF DRY AND COOLER WEATHER WITH AFTERNOON LAKE BREEZES. GUIDANCE REASONABLE IN DEPICTING TEMPS IN THE MID/UPPER 60S SUNDAY...AND MID 60S TO LOWER 70S MONDAY...WITH LOWER 60S LIKELY ALONG THE LAKE MICHIGAN SHORES. LOWS ARE EXPECTED TO BE IN THE 40S IN MANY AREAS AWAY FROM THE CHICAGO METRO SPRAWL SUNDAY NIGHT AND AGAIN MONDAY NIGHT. UPPER LEVEL RIDGE AXIS DEVELOPS ACROSS THE REGION INTO TUESDAY... WHILE CLOSED UPPER LOW CURRENTLY OFF THE BRITISH COLUMBIA COAST MAKES ITS WAY INTO THE NORTHERN PLAINS. AS THIS OCCURS...THE SFC HIGH OVER THE WESTERN LAKES WILL DRIFT TO THE EAST...WITH LOW LEVEL FLOW MORE SOUTH-SOUTHEAST ACROSS THE PLAINS AND MISSISSIPPI VALLEY BY MID-WEEK. THIS RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION WILL INITIALLY FOCUS ACROSS THE PLAINS AND INTO IA/MN TUESDAY/TUESDAY NIGHT...BUT WILL SHIFT FARTHER EAST AND BRING SHRA/TSRA CHANCES BACK TO OUR AREA LATER TUESDAY NIGHT AND WEDNESDAY. SOME GUIDANCE HINTS AT A FEW SHRA/TSRA MOVING INTO OUR NORTHWEST COUNTIES TUESDAY AFTERNOON...THOUGH THESE SHOULD BE DECAYING AS THEY MOVE OUT OF THE BETTER FORCING/MOISTURE WEST OF THE MISSISSIPPI AND HAVE MAINTAINED DRY FORECAST THROUGH THE DAY TUESDAY WITH LOW CONFIDENCE OF ANY PRECIP OF SIGNIFICANCE MAKING IT THIS FAR EAST. SHRA/TSRA CHANCES THEN INCREASE WEDNESDAY THROUGH THURSDAY AS UPPER LOW AND INVERTED SURFACE TROUGH/COLD FRONT MOVE ACROSS THE AREA. UPPER LOW FILLS AND OPENS UP DURING THIS TIME...WITH SOUTH WARM/MOIST ADVECTION FLOW NOT TERRIBLY STRONG. SUSPECT THERE WILL BE MANY DRY HOURS BETWEEN CLUSTERS OF SHRA/TSRA DURING THIS PERIOD. TEMPS MODERATE BACK INTO THE LOW-MID 70S/NEAR NORMAL DURING THE MID-WEEK PERIOD...THOUGH SOUTHEAST SYNOPTIC WINDS WILL KEEP WINDS OFF THE LAKE PARTICULARLY ACROSS NORTHEAST IL. SURFACE COLD FRONT SETTLES SLOWLY OFF TO THE SOUTH/SOUTHEAST OF THE CWA THURSDAY NIGHT...THOUGH UPPER TROUGH AXIS LINGERS ACROSS THE REGION INTO NEXT WEEKEND. HAVE HELD ONTO SOME SLIGHT CHANCE POPS FRIDAY WITH THE TROUGH AXIS OVERHEAD AND THE ECMWF CONTINUING TO SQUEEZE OUT QPF...THOUGH DRIER LOW LEVEL FLOW AROUND SFC HIGH PRESSURE OVER THE NORTHERN LAKES SHOULD HELP MAINTAIN GENERALLY DRY CONDITIONS BY FRIDAY NIGHT/SATURDAY. TEMPS DURING THE PERIOD EXPECTED TO BE NEAR NORMAL...70S...THOUGH ONSHORE WINDS OFF THE BIG POND WILL KEEP CONDITIONS COOLER NEAR THE LAKE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * MVFR CIGS PROBABLE BEHIND FRONT LATE TONIGHT INTO SUN AM * PERIOD OF IFR CIGS POSSIBLE SUNDAY MORNING * WIND SHIFT TO NE SUNDAY AFTERNOON WITH LAKE BREEZE IZZI //DISCUSSION...UPDATED 00Z... LAST VESTIAGES OF SHRA/TSRA WITH THIS SYSTEM ARE FINALLY MOVING OUT OF THE AREA WITH GENERALLY VFR CONDITIONS AND WEST WINDS EXPECTED REMAINDER OF THIS EVENING BEHIND THIS LAST BAND OF WEATHER. SECONDARY COLD FRONT WILL BLAST THROUGH THE AREA LATE TONIGHT WITH WIND SHIFT TO NNW AND SOME GUSTINESS EXPECTED. ANTICIPATE LOWER END MVFR CIGS TO DEVELOP BEHIND THE FRONT WITH SOME POTENTIAL FOR IFR CIGS...PARTICULARLY IF WINDS GO MORE NORTHERLY AND WE GET A LAKE INFLUENCE INTO THE TERMINALS. CIGS LIKELY TO SLOWLY LIFT DURING THE DAY SUNDAY WITH TRANSITION TO VFR LIKELY SUNDAY AFTERNOON ALONG WITH A WIND SHIFT TO NE WITH LAKE BREEZE. AT GYY...CLOSER PROXIMITY TO THE LAKE AND LIKELY FLOW OFF THE LAKE SHOULD RESULT IN A PERIOD OF IFR OR EVEN LIFR BEHIND THE FRONT EARLY SUNDAY MORNING. IZZI //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH CONFIDENCE IN WIND TRENDS * MEDIUM CONFIDENCE IN MVFR CIGS LATE TONIGHT/SUNDAY MORNING * LOW CONFIDENCE IN IFR CIGS LATE TONIGHT/SUNDAY MORNING * MEDIUM-HIGH CONFIDENCE ON WIND SHIFT TO NE SUNDAY AFTERNOON IZZI //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY AND TUESDAY...VFR. WEDNESDAY THROUGH FRIDAY...CHANCE OF SHRA/TSRA. IZZI && .MARINE... 218 PM CDT MODERATE SOUTHERLY WINDS ARE OCCURRING AHEAD OF AN AREA OF LOW PRESSURE AND ITS ATTENDANT COLD FRONT WHICH ARE EXPECTED TO PASS OVER THE LAKE TONIGHT. A BRIEF LULL IN THE WINDS MAY OCCUR WITH THE FRONTAL TROUGH THIS EVENING...BUT THEN WINDS ARE EXPECTED TO SHIFT TO NORTHWESTERLY AND RAMP BACK UP INTO THE 20 TO 25 KT RANGE FOR MUCH OF THE LAKE OVERNIGHT. WINDS SHOULD COME DOWN THROUGH THE DAY SUNDAY...REMAINING RELATIVELY LIGHT ON MONDAY WITH LAKE BREEZES DEVELOPING. ANOTHER AREA OF LOW PRESSURE BEGINS TO TAKE SHAPE OVER THE PLAINS LATE MONDAY INTO TUESDAY WITH SOUTHEASTERLY WINDS FRESHENING UP TO PERHAPS 15 TO 20 KT AT TIMES THROUGH THURSDAY. THURSDAY NIGHT...THE LOW WEAKENS AS IT PASSES SOUTH OF THE LAKE WITH WINDS TURNING NORTHERLY FRIDAY THROUGH THE WEEKEND. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
652 PM CDT SAT JUN 1 2013 .DISCUSSION... 308 PM CDT CONVETIVE TRENDS ARE THE MAIN FORECAST ISSUE THIS AFTERNOON. WILL MAINTAIN FLASH FLOOD WATCH ACROSS SOUTHERN TIER OF COUNTIES THROUGH ITS 00Z EXPIRATION. SURFACE LOW PRESSURE WAS CENTERED OVER CENTRAL WI AT MID AFTERNOON...WITH A COLD FRONT EXTENDING SOUTH THROUGH THE MISSISSIPPI RIVER VALLEY THEN SOUTHWEST ACROSS MISSOURI. DESPITE CONSIDERABLE CLOUD COVER NORTHWEST/WEST CENTRAL IL HAS DESTABILIZED AS EXPECTED THIS AFTERNOON...WITH SCATTERED SHRA/TSRA DEVELOPING ACROSS THE UIN-PIA-PNT AT 19Z. SPC RAP MESOANALYSIS GUIDANCE INDICATES AN AXIS OF 500-1000 J/KG AND GENERALLY CONVERGENT LOW LEVEL FLOW IN THAT REGION AHEAD OF THE SFC COLD FRONT...AND EXPECT THAT THIS ACTIVITY WILL CONTINUE TO DEVELOP AND SPREAD NORTHEAST OVER THE NEXT SEVERAL HOURS AIDED BY LARGE SCALE ASCENT ASSOCIATED WITH SHORT WAVE TROUGH PROPAGATING ACROSS IA/MO PER GOES WATER VAPOR IMAGERY. SUCCESSIVE RUNS OF THE HRRR HAVE MAINTAINED THE IDEA OF SCATTERED STORMS/SMALL CLUSTERS LIFTING NORTHEAST THROUGH THE CHICAGO METRO AREA THROUGH 23-01Z OR SO...BEFORE DIURNAL DECREASE IN INSTABILITY WITH SUNSET RESULTS IN DECREASE IN COVERAGE THIS EVENING. WHILE WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED...WITH EFFECTIVE BULK SHEAR APPROACHING 30 KT AND DRIER AIR ALOFT...MAINLY WEST WHERE A DCAPE AXIS OF 600-800 J/KG IS ANALYZED...WE COULD SEE A FEW OF THE STRONGEST CELLS PRODUCE A LITTLE HAIL OR WIND DURING THE REMAINDER OF THE AFTERNOON HOURS. ORGANIZED HEAVY RAINFALL SEEMS A FAIRLY LOW PROBABILITY AT THIS POINT...THOUGH ANALYSIS/GUIDANCE CONTINUES TO DEPICT PWATS NEAR 1.5 INCHES...BETTER LOW LEVEL MOISTURE TRANSPORT AND SLIGHTLY SLOWER STORM PROPAGATION POTENTIAL ACROSS THE SOUTHEASTERN COUNTIES OF THE CWA. SINCE A FLASH FLOOD WATCH IS ALREADY IN PLACE THERE...AND WITH THESE AREAS HAVING RECEIVED BETWEEN 2-3 INCHES OF RAINFALL IN YESTERDAY/LAST NIGHTS MCS/S...ILL ALLOW THE WATCH TO RUN THROUGH ITS 00Z EXPIRATION. COLD FRONT AND MID-LEVEL TROUGH AXIS PUSH ACROSS THE CWA THIS EVENING...WITH DRIER AIR AND HEIGHT RISES SPREADING IN FROM THE WEST OVERNIGHT. WEAKER SECONDARY FRONT TRAILS ACROSS THE AREA SUNDAY MORNING HOWEVER...WITH MOST GUIDANCE RUNS INDICATING THE POTENTIAL FOR A FEW SPOTTY SHOWERS MAINLY ACROSS EAST/SOUTHEAST PARTS OF THE FORECAST AREA. BEYOND THAT...SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA LATER SUNDAY THROUGH MONDAY MAKING FOR A COUPLE OF DAYS OF DRY AND COOLER WEATHER WITH AFTERNOON LAKE BREEZES. GUIDANCE REASONABLE IN DEPICTING TEMPS IN THE MID/UPPER 60S SUNDAY...AND MID 60S TO LOWER 70S MONDAY...WITH LOWER 60S LIKELY ALONG THE LAKE MICHIGAN SHORES. LOWS ARE EXPECTED TO BE IN THE 40S IN MANY AREAS AWAY FROM THE CHICAGO METRO SPRAWL SUNDAY NIGHT AND AGAIN MONDAY NIGHT. UPPER LEVEL RIDGE AXIS DEVELOPS ACROSS THE REGION INTO TUESDAY... WHILE CLOSED UPPER LOW CURRENTLY OFF THE BRITISH COLUMBIA COAST MAKES ITS WAY INTO THE NORTHERN PLAINS. AS THIS OCCURS...THE SFC HIGH OVER THE WESTERN LAKES WILL DRIFT TO THE EAST...WITH LOW LEVEL FLOW MORE SOUTH-SOUTHEAST ACROSS THE PLAINS AND MISSISSIPPI VALLEY BY MID-WEEK. THIS RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION WILL INITIALLY FOCUS ACROSS THE PLAINS AND INTO IA/MN TUESDAY/TUESDAY NIGHT...BUT WILL SHIFT FARTHER EAST AND BRING SHRA/TSRA CHANCES BACK TO OUR AREA LATER TUESDAY NIGHT AND WEDNESDAY. SOME GUIDANCE HINTS AT A FEW SHRA/TSRA MOVING INTO OUR NORTHWEST COUNTIES TUESDAY AFTERNOON...THOUGH THESE SHOULD BE DECAYING AS THEY MOVE OUT OF THE BETTER FORCING/MOISTURE WEST OF THE MISSISSIPPI AND HAVE MAINTAINED DRY FORECAST THROUGH THE DAY TUESDAY WITH LOW CONFIDENCE OF ANY PRECIP OF SIGNIFICANCE MAKING IT THIS FAR EAST. SHRA/TSRA CHANCES THEN INCREASE WEDNESDAY THROUGH THURSDAY AS UPPER LOW AND INVERTED SURFACE TROUGH/COLD FRONT MOVE ACROSS THE AREA. UPPER LOW FILLS AND OPENS UP DURING THIS TIME...WITH SOUTH WARM/MOIST ADVECTION FLOW NOT TERRIBLY STRONG. SUSPECT THERE WILL BE MANY DRY HOURS BETWEEN CLUSTERS OF SHRA/TSRA DURING THIS PERIOD. TEMPS MODERATE BACK INTO THE LOW-MID 70S/NEAR NORMAL DURING THE MID-WEEK PERIOD...THOUGH SOUTHEAST SYNOPTIC WINDS WILL KEEP WINDS OFF THE LAKE PARTICULARLY ACROSS NORTHEAST IL. SURFACE COLD FRONT SETTLES SLOWLY OFF TO THE SOUTH/SOUTHEAST OF THE CWA THURSDAY NIGHT...THOUGH UPPER TROUGH AXIS LINGERS ACROSS THE REGION INTO NEXT WEEKEND. HAVE HELD ONTO SOME SLIGHT CHANCE POPS FRIDAY WITH THE TROUGH AXIS OVERHEAD AND THE ECMWF CONTINUING TO SQUEEZE OUT QPF...THOUGH DRIER LOW LEVEL FLOW AROUND SFC HIGH PRESSURE OVER THE NORTHERN LAKES SHOULD HELP MAINTAIN GENERALLY DRY CONDITIONS BY FRIDAY NIGHT/SATURDAY. TEMPS DURING THE PERIOD EXPECTED TO BE NEAR NORMAL...70S...THOUGH ONSHORE WINDS OFF THE BIG POND WILL KEEP CONDITIONS COOLER NEAR THE LAKE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * SHRA/ISOLD TSRA ENDING SHORTLY AFTER 00Z * MVFR CIGS PROBABLE BEHIND FRONT LATE TONIGHT INTO SUN AM * PERIOD OF IFR CIGS POSSIBLE SUNDAY MORNING * WIND SHIFT TO NE SUNDAY AFTERNOON WITH LAKE BREEZE IZZI //DISCUSSION...UPDATED 00Z... LAST VESTIAGES OF SHRA/TSRA WITH THIS SYSTEM ARE FINALLY MOVING OUT OF THE AREA WITH GENERALLY VFR CONDITIONS AND WEST WINDS EXPECTED REMAINDER OF THIS EVENING BEHIND THIS LAST BAND OF WEATHER. SECONDARY COLD FRONT WILL BLAST THROUGH THE AREA LATE TONIGHT WITH WIND SHIFT TO NNW AND SOME GUSTINESS EXPECTED. ANTICIPATE LOWER END MVFR CIGS TO DEVELOP BEHIND THE FRONT WITH SOME POTENTIAL FOR IFR CIGS...PARTICULARLY IF WINDS GO MORE NORTHERLY AND WE GET A LAKE INFLUENCE INTO THE TERMINALS. CIGS LIKELY TO SLOWLY LIFT DURING THE DAY SUNDAY WITH TRANSITION TO VFR LIKELY SUNDAY AFTERNOON ALONG WITH A WIND SHIFT TO NE WITH LAKE BREEZE. AT GYY...CLOSER PROXIMITY TO THE LAKE AND LIKELY FLOW OFF THE LAKE SHOULD RESULT IN A PERIOD OF IFR OR EVEN LIFR BEHIND THE FRONT EARLY SUNDAY MORNING. IZZI //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH CONFIDENCE IN PRECIP TRENDS * MEDIUM-HIGH CONFIDENCE IN WIND TRENDS * MEDIUM CONFIDENCE IN MVFR CIGS LATE TONIGHT/SUNDAY MORNING * LOW CONFIDENCE IN IFR CIGS LATE TONIGHT/SUNDAY MORNING * MEDIUM-HIGH CONFIDENCE ON WIND SHIFT TO NE SUNDAY AFTERNOON IZZI //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY AND TUESDAY...VFR. WEDNESDAY THROUGH FRIDAY...CHANCE OF SHRA/TSRA. IZZI && .MARINE... 218 PM CDT MODERATE SOUTHERLY WINDS ARE OCCURRING AHEAD OF AN AREA OF LOW PRESSURE AND ITS ATTENDANT COLD FRONT WHICH ARE EXPECTED TO PASS OVER THE LAKE TONIGHT. A BRIEF LULL IN THE WINDS MAY OCCUR WITH THE FRONTAL TROUGH THIS EVENING...BUT THEN WINDS ARE EXPECTED TO SHIFT TO NORTHWESTERLY AND RAMP BACK UP INTO THE 20 TO 25 KT RANGE FOR MUCH OF THE LAKE OVERNIGHT. WINDS SHOULD COME DOWN THROUGH THE DAY SUNDAY...REMAINING RELATIVELY LIGHT ON MONDAY WITH LAKE BREEZES DEVELOPING. ANOTHER AREA OF LOW PRESSURE BEGINS TO TAKE SHAPE OVER THE PLAINS LATE MONDAY INTO TUESDAY WITH SOUTHEASTERLY WINDS FRESHENING UP TO PERHAPS 15 TO 20 KT AT TIMES THROUGH THURSDAY. THURSDAY NIGHT...THE LOW WEAKENS AS IT PASSES SOUTH OF THE LAKE WITH WINDS TURNING NORTHERLY FRIDAY THROUGH THE WEEKEND. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ032-ILZ039 UNTIL 7 PM SATURDAY. FLASH FLOOD WATCH...ILZ033 UNTIL 10 PM SATURDAY. IN...FLASH FLOOD WATCH...INZ010-INZ011-INZ019 UNTIL 10 PM SATURDAY. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 9 PM SATURDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
533 PM CDT FRI MAY 31 2013 .DISCUSSION... 336 PM CDT THOUGHTS FROM THE EARLIER MESO DISCUSSION ARE STILL VALID AND HAVE BEEN BOLSTERED BY THE SPREAD OF SHOWERS WITH ISOLATED TSRA INTO THE FCST AREA THIS AFTERNOON WITH LITTLE ADDITIONAL DEVELOPMENT DIRECTLY WEST OVER IOWA SO FAR. 0-6 KM BULK SHEAR CONTINUES TO BE MARGINAL OVER MOST OF THE LOCAL REGION BUT IS BUILDING TOWARD 40 KTS IN THE AREA OF APPROACHING CONVECTION TO OUR SOUTHWEST UNDER THE LEADING EDGE OF AN UPPER LEVEL JET. A FEW STORMS COULD BECOME ORGANIZED IN SOUTHERN PORTIONS OF THE CWA...THOUGH THE SEVERE RISK OVERALL APPEARS TO BE MARGINAL. TRENDS FOR THIS EVENING AND OVERNIGHT ALSO WOULD CONTINUE TO FAVOR SOUTHERN PORTIONS OF THE CWA FOR THE HEAVIEST RAINFALL AMOUNTS AND THE CORRESPONDING FLOOD RISK...AND THIS ALSO IS WHERE THE MOST RAIN HAS FALLEN OVER THE PAST WEEK. FOR THESE REASONS...AFTER COORDINATION WITH NEIGHBORS...WILL PLAN TO DROP THE FLOOD WATCH FOR NORTHERN PORTIONS OF THE FORECAST AREA. ALL OF THIS ACTIVITY IS BEING DRIVEN BY RICH BOUNDARY LAYER GULF MOISTURE WRAPPING AROUND THE WESTERN SIDE OF A BERMUDA HIGH...AND AHEAD OF AN APPROACHING FRONTAL ZONE TIED TO LOW PRESSURE OVER THE DAKOTAS. THIS FRONTAL ZONE PUSHES THROUGH THE AREA SATURDAY NIGHT AND USHERS IN COOLER AND DRIER AIR FOR THE FIRST HALF OF NEXT WEEK. UNSETTLED WEATHER WILL PERSIST UNTIL THAT TIME WITH THE FOCUS GRADUALLY SHIFTING EASTWARD. SHOWER AND THUNDERSTORM FORECAST TRENDS FOR THIS EVENING AND OVERNIGHT ARE BASED ON CURRENT ACTIVITY AND THE IDEA OF INCREASING DEVELOPMENT SUPPORTED BY LOW LEVEL MOISTURE CONVERGENCE BEING DEPICTED IN THE RAP MODEL. IF THESE RAP FIELDS CONTINUE TO BE VALID TOWARD MORNING...THE NORTHWEST HALF OF THE AREA WOULD APPEAR TO DRY OUT BY MIDNIGHT AND REMAIN SO INTO THE MORNING HOURS. THIS TREND ALSO IS SUPPORTED BY THE LATEST NAM/ECMWF/GFS QPF FIELDS. CHANCES THEN INCREASE AGAIN DURING THE DAY TOMORROW AHEAD OF THE APPROACHING UPPER LEVEL VORT MAX AND THE SURFACE FRONTAL ZONE. AFTER A COOLER AND DRIER END TO THE WEEKEND AND START TO THE WORK WEEK...THE NEXT UPPER TROUGH AND SFC LOW BEGIN TO APPROACH THE AREA TOWARD THE MIDDLE OF NEXT WEEK ALONG THE SIMILAR DAKOTAS TRACK THAT WE HAVE SEEN WITH THE CURRENT SYSTEM. SFC WINDS TURNING SOUTHEAST BY WEDNESDAY AND SOUTH BY THURSDAY WOULD ALLOW WARM MOIST GULF AIR TO START WORKING BACK INTO THE AREA FOR LATE NEXT WEEK...BUT AT THIS RANGE WILL ONLY PLAN TO CARRY CHANCE POPS. LENNING && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * WINDS MAY BACK TO SE FOR TIME EARLY THIS EVENING * CHANCE OF MVFR CIGS DEVELOPING THIS EVENING * CHANCE OF SHRA/TSRA AGAIN SAT AFTERNOON IZZI //DISCUSSION...UPDATED 22Z... HAVE REMOVED PRECIP FOR TONIGHT WITH AXIS OF MOST ORGANIZED PRECIPITATION LIKELY TO REMAIN WELL SOUTH OF THE CHGO TERMINALS. AM CLOSELY WATCHING AREA OF DEVELOPING LOWER END MVFR CIGS OVER WC IL...IF THIS AREA CONTINUES TO EXPAND MAY NEED TO INTRODUCE SOME MVFR CIGS LATER THIS EVENING INTO THE OVERNIGHT HOURS. IZZI UPDATED 18Z... THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS. EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST. STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT BE AS STRONG. JEE //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM CONFIDENCE IN WINDS THIS EVENING * LOW/MEDIUM CONFIDENCE IN CIGS TONIGHT * LOW CONFIDENCE IN TSRA CHANCES SATURDAY IZZI //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE. SUNDAY...SLT CHC OF MORNING SHRA. MONDAY...VFR LIKELY. TUESDAY...CHC OF MORNING MVFR. WEDNESDAY & THURSDAY...CHC OF TSRA. MTF && .MARINE... 222 PM CDT AN AREA OF LOW PRESSURE THAT HAS PERSISTED OVER THE NORTHERN PLAINS WILL FINALLY BEGIN TO MOVE EAST TONIGHT...PASSING OVER NORTHERN LAKE MICHIGAN LATE SATURDAY EVENING WITH A TRAILING COLD FRONT TURNING MODERATE SOUTHERLY WINDS OF 15 TO 25 KT TO NORTHWESTERLY. MOIST FLOW AHEAD OF THE FRONT HAS ALREADY LED TO DENSE FOG OVER MUCH OF THE LAKE WHICH IS EXPECTED TO PERSIST UNTIL THE COLD FRONT PASSES SATURDAY NIGHT. WINDS SHOULD THEN DIMINISH THROUGH THE DAY SUNDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST...BECOMING CENTERED OVER LAKE MICHIGAN ON MONDAY. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS MONDAY...THEN LIFT NORTHEAST TO LAKE MICHIGAN LATE THURSDAY INTO EARLY FRIDAY. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7 PM SATURDAY. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870- LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
337 PM CDT FRI MAY 31 2013 .DISCUSSION... 336 PM CDT THOUGHTS FROM THE EARLIER MESO DISCUSSION ARE STILL VALID AND HAVE BEEN BOLSTERED BY THE SPREAD OF SHOWERS WITH ISOLATED TSRA INTO THE FCST AREA THIS AFTERNOON WITH LITTLE ADDITIONAL DEVELOPMENT DIRECTLY WEST OVER IOWA SO FAR. 0-6 KM BULK SHEAR CONTINUES TO BE MARGINAL OVER MOST OF THE LOCAL REGION BUT IS BUILDING TOWARD 40 KTS IN THE AREA OF APPROACHING CONVECTION TO OUR SOUTHWEST UNDER THE LEADING EDGE OF AN UPPER LEVEL JET. A FEW STORMS COULD BECOME ORGANIZED IN SOUTHERN PORTIONS OF THE CWA...THOUGH THE SEVERE RISK OVERALL APPEARS TO BE MARGINAL. TRENDS FOR THIS EVENING AND OVERNIGHT ALSO WOULD CONTINUE TO FAVOR SOUTHERN PORTIONS OF THE CWA FOR THE HEAVIEST RAINFALL AMOUNTS AND THE CORRESPONDING FLOOD RISK...AND THIS ALSO IS WHERE THE MOST RAIN HAS FALLEN OVER THE PAST WEEK. FOR THESE REASONS...AFTER COORDINATION WITH NEIGHBORS...WILL PLAN TO DROP THE FLOOD WATCH FOR NORTHERN PORTIONS OF THE FORECAST AREA. ALL OF THIS ACTIVITY IS BEING DRIVEN BY RICH BOUNDARY LAYER GULF MOISTURE WRAPPING AROUND THE WESTERN SIDE OF A BERMUDA HIGH...AND AHEAD OF AN APPROACHING FRONTAL ZONE TIED TO LOW PRESSURE OVER THE DAKOTAS. THIS FRONTAL ZONE PUSHES THROUGH THE AREA SATURDAY NIGHT AND USHERS IN COOLER AND DRIER AIR FOR THE FIRST HALF OF NEXT WEEK. UNSETTLED WEATHER WILL PERSIST UNTIL THAT TIME WITH THE FOCUS GRADUALLY SHIFTING EASTWARD. SHOWER AND THUNDERSTORM FORECAST TRENDS FOR THIS EVENING AND OVERNIGHT ARE BASED ON CURRENT ACTIVITY AND THE IDEA OF INCREASING DEVELOPMENT SUPPORTED BY LOW LEVEL MOISTURE CONVERGENCE BEING DEPICTED IN THE RAP MODEL. IF THESE RAP FIELDS CONTINUE TO BE VALID TOWARD MORNING...THE NORTHWEST HALF OF THE AREA WOULD APPEAR TO DRY OUT BY MIDNIGHT AND REMAIN SO INTO THE MORNING HOURS. THIS TREND ALSO IS SUPPORTED BY THE LATEST NAM/ECMWF/GFS QPF FIELDS. CHANCES THEN INCREASE AGAIN DURING THE DAY TOMORROW AHEAD OF THE APPROACHING UPPER LEVEL VORT MAX AND THE SURFACE FRONTAL ZONE. AFTER A COOLER AND DRIER END TO THE WEEKEND AND START TO THE WORK WEEK...THE NEXT UPPER TROUGH AND SFC LOW BEGIN TO APPROACH THE AREA TOWARD THE MIDDLE OF NEXT WEEK ALONG THE SIMILAR DAKOTAS TRACK THAT WE HAVE SEEN WITH THE CURRENT SYSTEM. SFC WINDS TURNING SOUTHEAST BY WEDNESDAY AND SOUTH BY THURSDAY WOULD ALLOW WARM MOIST GULF AIR TO START WORKING BACK INTO THE AREA FOR LATE NEXT WEEK...BUT AT THIS RANGE WILL ONLY PLAN TO CARRY CHANCE POPS. LENNING && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * GUSTY S WINDS EXPECTED THROUGH THIS AFTN WITH A BRIEF PERIOD OF SSE WINDS PSBL BEHIND TSRA/SHRA. * SHRA OR TSRA PSBL THIS AFTN WITH MVFR VSBY PSBL WITH TSRA. * SCT SHOWERS OVERNIGHT. * ANOTHER ROUND OF TSRA/SHRA EXPECTED TOMORROW AFTN. JEE //DISCUSSION...UPDATED 18Z... THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS. EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST. STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT BE AS STRONG. JEE //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN PRECIP AFFECTING THE TERMINALS. * LOW CONFIDENCE IN TIMING AND DURATION. * LOW CONFIDENCE IN SHRA COVERAGE TONIGHT. * MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA TOMORROW AFTERNOON. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE. SUNDAY...SLT CHC OF MORNING SHRA. MONDAY...VFR LIKELY. TUESDAY...CHC OF MORNING MVFR. WEDNESDAY & THURSDAY...CHC OF TSRA. MTF && .MARINE... 222 PM CDT AN AREA OF LOW PRESSURE THAT HAS PERSISTED OVER THE NORTHERN PLAINS WILL FINALLY BEGIN TO MOVE EAST TONIGHT...PASSING OVER NORTHERN LAKE MICHIGAN LATE SATURDAY EVENING WITH A TRAILING COLD FRONT TURNING MODERATE SOUTHERLY WINDS OF 15 TO 25 KT TO NORTHWESTERLY. MOIST FLOW AHEAD OF THE FRONT HAS ALREADY LED TO DENSE FOG OVER MUCH OF THE LAKE WHICH IS EXPECTED TO PERSIST UNTIL THE COLD FRONT PASSES SATURDAY NIGHT. WINDS SHOULD THEN DIMINISH THROUGH THE DAY SUNDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST...BECOMING CENTERED OVER LAKE MICHIGAN ON MONDAY. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS MONDAY...THEN LIFT NORTHEAST TO LAKE MICHIGAN LATE THURSDAY INTO EARLY FRIDAY. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7 PM SATURDAY. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870- LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 7 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
257 PM CDT FRI MAY 31 2013 .MESOSCALE DISCUSSION... INITIAL LOOK AT THE ATMOSPHERE IN PREPARATION OF AFTERNOON/EVENING CONVECTION. SUPPORT FOR WIDESPREAD SEVERE APPEARS TO BE LESS PRONOUNCED THAN EARLIER SIGNALS HAD SUGGESTED. A MINIMA OF 0-6KM BULK SHEAR EXISTS EARLY THIS AFTERNOON ACROSS NORTHCENTRAL/NORTHEAST ILLINOIS STRETCHING INTO NORTHWEST INDIANA. ALONG THE WESTERN PERIPHERY OF THIS MINIMA IS AN AXIS OF MUCH HIGHER SHEAR AROUND 70KTS IN IOWA...TO NEARLY 80KTS STRETCHING SOUTH INTO CENTRAL MISSOURI. VISIBLE IMAGERY SHOWS CONSIDERABLE CLOUD COVER...REMNANTS/BLOWOFF OF EARLIER CONVECTION TO THE SOUTHWEST...LIFTING NORTHEAST ACROSS THE CWFA AT THIS TIME. THIS WILL INHIBIT SFC CAPE FROM GETTING OUT OF CONTROL THROUGH EARLY THIS AFTERNOON...AND TOGETHER WITH THE MARGINAL SHEAR WOULD TEND TO LIMIT THE LOCAL POTENTIAL FOR ORGANIZED CONVECTION OVER THE NEXT FEW HOURS. MORNING CONVECTION IN MISSOURI CORRELATED TO AN AXIS OF LOW LEVEL MOISTURE CONVERGENCE AND A WEAK TROUGH DEPICTED AT 850 MB. LATEST FIELDS FROM THE RAP MODEL SHOW THIS TROUGH AND THE WESTERN FOCUS FOR THIS MOISTURE CONVERGENCE EXPANDING OUT OF THE SAINT LOUIS AREA ACROSS ILLINOIS AND WORKING INTO THE CHICAGO METRO AREA BY LATE AFTERNOON...22Z TO 00Z...WHILE GRADUALLY BECOMING LESS FOCUSED. HI-RES GUIDANCE IS SUGGESTING THAT AS THIS CONVECTION BEGINS TO LIFT THROUGH SW IL...IT WILL EXPAND ALONG A LINE STRETCHING FROM SAINT LOUIS THROUGH BLOOMINGTON TO KANKAKEE AND TOWARD MICHIGAN CITY. A SMALLER AREA OF LATE MORNING AND EARLY AFTERNOON ISOLATED STORMS OVER IOWA ALSO IS NICELY CORRELATED TO AN AXIS OF MOISTURE CONVERGENCE IN THE RAP...BUT WAS MUCH LESS PRONOUNCED AND MIGRATING MORE TO THE NORTH RATHER THAN EAST INTO ILLINOIS. THIS CONVECTION WAS CLOSER TO THE 500MB VORT MAX AND IN AN AREA OF ANTICIPATED STEEPENING LAPSE RATES THROUGHOUT THE AFTN. AS THE TROUGH AXIS SLOWLY SLIDES EAST...SOME OF THIS MAY PUSH INTO NORTHWEST IL BUT MAY NOT HAVE THE LONGEVITY TO CONTINUE ACROSS NORTHCENTRAL/NORTHEAST IL. BEACHLER/LENNING && .DISCUSSION... 328 AM...MAIN FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS/TIMING THROUGH SATURDAY EVENING ALONG WITH POTENTIAL FOR SEVERE WEATHER AND HEAVY RAIN/FLOODING. WAVE OF SHOWERS WITH SOME EMBEDDED THUNDER WILL CONTINUE LIFTING NORTHEAST AWAY FROM THE AREA EARLY THIS MORNING WITH SUBSIDENCE INTO THE MID MORNING HOURS EXPECTED TO BRING SEVERAL HOURS OF DRY WEATHER. ATTENTION THEN SHIFTS TO CONVECTION OVER NORTHEAST KANSAS/NORTHWEST MISSOURI. MOST RECENT HRRR/RAP GUIDANCE SEEMS IN BETTER AGREEMENT WITH 00Z SUITE OF MODELS SHOWING THIS ACTIVITY SPREADING EAST/NORTHEAST AS THE MAIN SHORTWAVE LIFTS NORTHEAST... THEN SUGGESTS RAPID DEVELOPMENT ACROSS WESTERN AND NORTH CENTRAL IL THIS AFTERNOON...PERHAPS EARLY THIS AFTERNOON. HOWEVER... THERE STILL REMAINS SOME UNCERTAINTY REGARDING WHERE CONVECTION DEVELOPS AND WHETHER IT AFFECTS ALL OR PART OF THE CWA. CONFIDENCE INCREASES ACROSS THE SOUTHERN HALF/TWO THIRDS OF THE AREA. WITH THE EXPECTATION THAT THIS MORNING WILL END UP BEING MAINLY DRY AND EVENTUALLY PARTLY/MOSTLY SUNNY...TEMPS REACHING LOWER 80S SEEMS ON TRACK ALONG WITH DEWPOINTS REBOUNDING BACK INTO THE MID/UPPER 60S. SUFFICIENT SHEAR AND STRONG LAPSE RATES COMBINED WITH THE VERY MOIST/UNSTABLE LOW LEVELS WILL SUPPORT SEVERE WEATHER ACROSS THE ENTIRE AREA WITH THE MAIN THREAT APPEARING TO BE DAMAGING WINDS WITH ASSOCIATED LINES/BOWING SEGMENTS. THOUGH LARGE HAIL WITH STRONGER CORES AND ISOLATED TORNADOES WILL REMAIN POSSIBLE. CONVECTION WILL THEN SHIFT EAST THIS EVENING/OVERNIGHT. AS THE UPPER TROUGH MOVES CLOSER TO THE WESTERN LAKES SATURDAY...ANOTHER WAVE IS EXPECTED TO LIFT NORTHEAST SATURDAY BUT LIKELY BE A LITTLE FURTHER EAST WITH CONVECTION LIKELY AFFECTING MAINLY EASTERN IL AND NORTHWEST INDIANA...PERHAPS ALONG/EAST OF THE I-55 OR I-57 CORRIDORS. SEVERE WEATHER WILL ONCE AGAIN BE POSSIBLE SATURDAY AFTERNOON INTO SATURDAY EVENING. NO CHANGES PLANNED TO THE FLASH FLOOD WATCH WHICH IS IN EFFECT FOR THE ENTIRE AREA THROUGH SATURDAY EVENING. FORECAST STORM TOTAL RAINFALL...FROM THIS MORNING THROUGH SATURDAY EVENING...RANGES FROM ABOUT AN INCH NEAR THE WI/IL BORDER TO 2-2.5 INCHES FROM A CHICAGO/PERU LINE SOUTH. SOME AREAS WILL LIKELY SEE LESS AND SOME AREAS MAY SEE MORE. INDIVIDUAL STORM MOTION WILL PROBABLY BE FAST ENOUGH THAT WHILE HEAVY/TORRENTIAL RAIN WILL FALL...ITS DURATION COULD BE SHORT. BUT IF THE STORMS BEGIN TO TRAIN OVER THE SAME AREAS...WITH RAINFALL RATES OF 1 TO 2+ INCHES/HOUR...ON ALREADY SATURATED GROUND...THEN FLASH FLOODING MAY BE POSSIBLE. AS THE UPPER TROUGH/SURFACE LOW FINALLY DEPART SUNDAY...ONE LAST WAVE PIVOTING AROUND THE WESTERN LAKES COULD PRODUCE SOME SHOWERS SUNDAY MORNING. BROAD BUT WEAK HIGH PRESSURE THEN BUILDS ACROSS THE LAKES SUNDAY AFTERNOON THROUGH MONDAY WITH A SHOT OF COOLER AIR. WHILE HIGHS ON SUNDAY ARE ONLY EXPECTED TO BE IN THE 60S...LOWER 70S SOUTH...WINDS WILL TURN OFF THE LAKE SUNDAY AFTERNOON...THUS COOLER/FALLING TEMPS AT THE LAKE SUNDAY AFTERNOON. LOWS THEN DROP INTO THE 40S IN MANY AREAS MONDAY MORNING AND POSSIBLY TUESDAY MORNING AS WELL. SEVERAL DAYS OF EASTERLY WINDS WILL KEEP THE LAKE SHORE AREAS COOLER NEXT WEEK. PATTERN APPEARS TO TURN MORE ACTIVE AGAIN TUESDAY INTO WEDNESDAY AS ANOTHER SLOW MOVING UPPER LOW TRACKS ACROSS THE PLAINS THOUGH ITS STILL FAIRLY EARLY TO DETERMINE WHERE AND WHEN THIS LOW WILL MOVE THOUGH HAVE INCLUDED CHANCE POPS INTO MID/LATE WEEK AS THIS NEXT SYSTEM POTENTIALLY APPROACHES. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * GUSTY S WINDS EXPECTED THROUGH THIS AFTN WITH A BRIEF PERIOD OF SSE WINDS PSBL BEHIND TSRA/SHRA. * SHRA OR TSRA PSBL THIS AFTN WITH MVFR VSBY PSBL WITH TSRA. * SCT SHOWERS OVERNIGHT. * ANOTHER ROUND OF TSRA/SHRA EXPECTED TOMORROW AFTN. JEE //DISCUSSION...UPDATED 18Z... THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS. EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST. STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT BE AS STRONG. JEE //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM CONFIDENCE IN PRECIP AFFECTING THE TERMINALS. * LOW CONFIDENCE IN TIMING AND DURATION. * LOW CONFIDENCE IN SHRA COVERAGE TONIGHT. * MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA TOMORROW AFTERNOON. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE. SUNDAY...SLT CHC OF MORNING SHRA. MONDAY...VFR LIKELY. TUESDAY...CHC OF MORNING MVFR. WEDNESDAY & THURSDAY...CHC OF TSRA. MTF && .MARINE... 222 PM CDT AN AREA OF LOW PRESSURE THAT HAS PERSISTED OVER THE NORTHERN PLAINS WILL FINALLY BEGIN TO MOVE EAST TONIGHT...PASSING OVER NORTHERN LAKE MICHIGAN LATE SATURDAY EVENING WITH A TRAILING COLD FRONT TURNING MODERATE SOUTHERLY WINDS OF 15 TO 25 KT TO NORTHWESTERLY. MOIST FLOW AHEAD OF THE FRONT HAS ALREADY LED TO DENSE FOG OVER MUCH OF THE LAKE WHICH IS EXPECTED TO PERSIST UNTIL THE COLD FRONT PASSES SATURDAY NIGHT. WINDS SHOULD THEN DIMINISH THROUGH THE DAY SUNDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST...BECOMING CENTERED OVER LAKE MICHIGAN ON MONDAY. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS MONDAY...THEN LIFT NORTHEAST TO LAKE MICHIGAN LATE THURSDAY INTO EARLY FRIDAY. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7 PM SATURDAY. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870- LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
225 PM CDT FRI MAY 31 2013 .MESOSCALE DISCUSSION... INITIAL LOOK AT THE ATMOSPHERE IN PREPARATION OF AFTERNOON/EVENING CONVECTION. SUPPORT FOR WIDESPREAD SEVERE APPEARS TO BE LESS PRONOUNCED THAN EARLIER SIGNALS HAD SUGGESTED. A MINIMA OF 0-6KM BULK SHEAR EXISTS EARLY THIS AFTERNOON ACROSS NORTHCENTRAL/NORTHEAST ILLINOIS STRETCHING INTO NORTHWEST INDIANA. ALONG THE WESTERN PERIPHERY OF THIS MINIMA IS AN AXIS OF MUCH HIGHER SHEAR AROUND 70KTS IN IOWA...TO NEARLY 80KTS STRETCHING SOUTH INTO CENTRAL MISSOURI. VISIBLE IMAGERY SHOWS CONSIDERABLE CLOUD COVER...REMNANTS/BLOWOFF OF EARLIER CONVECTION TO THE SOUTHWEST...LIFTING NORTHEAST ACROSS THE CWFA AT THIS TIME. THIS WILL INHIBIT SFC CAPE FROM GETTING OUT OF CONTROL THROUGH EARLY THIS AFTERNOON...AND TOGETHER WITH THE MARGINAL SHEAR WOULD TEND TO LIMIT THE LOCAL POTENTIAL FOR ORGANIZED CONVECTION OVER THE NEXT FEW HOURS. MORNING CONVECTION IN MISSOURI CORRELATED TO AN AXIS OF LOW LEVEL MOISTURE CONVERGENCE AND A WEAK TROUGH DEPICTED AT 850 MB. LATEST FIELDS FROM THE RAP MODEL SHOW THIS TROUGH AND THE WESTERN FOCUS FOR THIS MOISTURE CONVERGENCE EXPANDING OUT OF THE SAINT LOUIS AREA ACROSS ILLINOIS AND WORKING INTO THE CHICAGO METRO AREA BY LATE AFTERNOON...22Z TO 00Z...WHILE GRADUALLY BECOMING LESS FOCUSED. HI-RES GUIDANCE IS SUGGESTING THAT AS THIS CONVECTION BEGINS TO LIFT THROUGH SW IL...IT WILL EXPAND ALONG A LINE STRETCHING FROM SAINT LOUIS THROUGH BLOOMINGTON TO KANKAKEE AND TOWARD MICHIGAN CITY. A SMALLER AREA OF LATE MORNING AND EARLY AFTERNOON ISOLATED STORMS OVER IOWA ALSO IS NICELY CORRELATED TO AN AXIS OF MOISTURE CONVERGENCE IN THE RAP...BUT WAS MUCH LESS PRONOUNCED AND MIGRATING MORE TO THE NORTH RATHER THAN EAST INTO ILLINOIS. THIS CONVECTION WAS CLOSER TO THE 500MB VORT MAX AND IN AN AREA OF ANTICIPATED STEEPENING LAPSE RATES THROUGHOUT THE AFTN. AS THE TROUGH AXIS SLOWLY SLIDES EAST...SOME OF THIS MAY PUSH INTO NORTHWEST IL BUT MAY NOT HAVE THE LONGEVITY TO CONTINUE ACROSS NORTHCENTRAL/NORTHEAST IL. BEACHLER/LENNING && .DISCUSSION... 328 AM...MAIN FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS/TIMING THROUGH SATURDAY EVENING ALONG WITH POTENTIAL FOR SEVERE WEATHER AND HEAVY RAIN/FLOODING. WAVE OF SHOWERS WITH SOME EMBEDDED THUNDER WILL CONTINUE LIFTING NORTHEAST AWAY FROM THE AREA EARLY THIS MORNING WITH SUBSIDENCE INTO THE MID MORNING HOURS EXPECTED TO BRING SEVERAL HOURS OF DRY WEATHER. ATTENTION THEN SHIFTS TO CONVECTION OVER NORTHEAST KANSAS/NORTHWEST MISSOURI. MOST RECENT HRRR/RAP GUIDANCE SEEMS IN BETTER AGREEMENT WITH 00Z SUITE OF MODELS SHOWING THIS ACTIVITY SPREADING EAST/NORTHEAST AS THE MAIN SHORTWAVE LIFTS NORTHEAST... THEN SUGGESTS RAPID DEVELOPMENT ACROSS WESTERN AND NORTH CENTRAL IL THIS AFTERNOON...PERHAPS EARLY THIS AFTERNOON. HOWEVER... THERE STILL REMAINS SOME UNCERTAINTY REGARDING WHERE CONVECTION DEVELOPS AND WHETHER IT AFFECTS ALL OR PART OF THE CWA. CONFIDENCE INCREASES ACROSS THE SOUTHERN HALF/TWO THIRDS OF THE AREA. WITH THE EXPECTATION THAT THIS MORNING WILL END UP BEING MAINLY DRY AND EVENTUALLY PARTLY/MOSTLY SUNNY...TEMPS REACHING LOWER 80S SEEMS ON TRACK ALONG WITH DEWPOINTS REBOUNDING BACK INTO THE MID/UPPER 60S. SUFFICIENT SHEAR AND STRONG LAPSE RATES COMBINED WITH THE VERY MOIST/UNSTABLE LOW LEVELS WILL SUPPORT SEVERE WEATHER ACROSS THE ENTIRE AREA WITH THE MAIN THREAT APPEARING TO BE DAMAGING WINDS WITH ASSOCIATED LINES/BOWING SEGMENTS. THOUGH LARGE HAIL WITH STRONGER CORES AND ISOLATED TORNADOES WILL REMAIN POSSIBLE. CONVECTION WILL THEN SHIFT EAST THIS EVENING/OVERNIGHT. AS THE UPPER TROUGH MOVES CLOSER TO THE WESTERN LAKES SATURDAY...ANOTHER WAVE IS EXPECTED TO LIFT NORTHEAST SATURDAY BUT LIKELY BE A LITTLE FURTHER EAST WITH CONVECTION LIKELY AFFECTING MAINLY EASTERN IL AND NORTHWEST INDIANA...PERHAPS ALONG/EAST OF THE I-55 OR I-57 CORRIDORS. SEVERE WEATHER WILL ONCE AGAIN BE POSSIBLE SATURDAY AFTERNOON INTO SATURDAY EVENING. NO CHANGES PLANNED TO THE FLASH FLOOD WATCH WHICH IS IN EFFECT FOR THE ENTIRE AREA THROUGH SATURDAY EVENING. FORECAST STORM TOTAL RAINFALL...FROM THIS MORNING THROUGH SATURDAY EVENING...RANGES FROM ABOUT AN INCH NEAR THE WI/IL BORDER TO 2-2.5 INCHES FROM A CHICAGO/PERU LINE SOUTH. SOME AREAS WILL LIKELY SEE LESS AND SOME AREAS MAY SEE MORE. INDIVIDUAL STORM MOTION WILL PROBABLY BE FAST ENOUGH THAT WHILE HEAVY/TORRENTIAL RAIN WILL FALL...ITS DURATION COULD BE SHORT. BUT IF THE STORMS BEGIN TO TRAIN OVER THE SAME AREAS...WITH RAINFALL RATES OF 1 TO 2+ INCHES/HOUR...ON ALREADY SATURATED GROUND...THEN FLASH FLOODING MAY BE POSSIBLE. AS THE UPPER TROUGH/SURFACE LOW FINALLY DEPART SUNDAY...ONE LAST WAVE PIVOTING AROUND THE WESTERN LAKES COULD PRODUCE SOME SHOWERS SUNDAY MORNING. BROAD BUT WEAK HIGH PRESSURE THEN BUILDS ACROSS THE LAKES SUNDAY AFTERNOON THROUGH MONDAY WITH A SHOT OF COOLER AIR. WHILE HIGHS ON SUNDAY ARE ONLY EXPECTED TO BE IN THE 60S...LOWER 70S SOUTH...WINDS WILL TURN OFF THE LAKE SUNDAY AFTERNOON...THUS COOLER/FALLING TEMPS AT THE LAKE SUNDAY AFTERNOON. LOWS THEN DROP INTO THE 40S IN MANY AREAS MONDAY MORNING AND POSSIBLY TUESDAY MORNING AS WELL. SEVERAL DAYS OF EASTERLY WINDS WILL KEEP THE LAKE SHORE AREAS COOLER NEXT WEEK. PATTERN APPEARS TO TURN MORE ACTIVE AGAIN TUESDAY INTO WEDNESDAY AS ANOTHER SLOW MOVING UPPER LOW TRACKS ACROSS THE PLAINS THOUGH ITS STILL FAIRLY EARLY TO DETERMINE WHERE AND WHEN THIS LOW WILL MOVE THOUGH HAVE INCLUDED CHANCE POPS INTO MID/LATE WEEK AS THIS NEXT SYSTEM POTENTIALLY APPROACHES. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * GUSTY S WINDS EXPECTED THIS AFTN WITH A BRIEF PERIOD OF SSE WINDS PSBL BEHIND TSRA. * BRIEF PERIOD OF TSRA THIS AFTN WITH MVFR VSBY PSBL. * SHRA EXPECTED BEHIND TSRA WITH SCT SHOWERS OVERNIGHT. * ANOTHER ROUND OF TSRA/SHRA EXPECTED TOMORROW AFTN. JEE //DISCUSSION...UPDATED 18Z... THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS. EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST. STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT BE AS STRONG. JEE //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN PRECIP AFFECTING THE AIRPORTS THIS AFTERNOON. * LOW CONFIDENCE IN TIMING AND DURATION. * LOW CONFIDENCE IN SHRA COVERAGE TONIGHT. * MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA TOMORROW AFTERNOON. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE. SUNDAY...SLT CHC OF MORNING SHRA. MONDAY...VFR LIKELY. TUESDAY...CHC OF MORNING MVFR. WEDNESDAY & THURSDAY...CHC OF TSRA. MTF && .MARINE... 222 PM CDT AN AREA OF LOW PRESSURE THAT HAS PERSISTED OVER THE NORTHERN PLAINS WILL FINALLY BEGIN TO MOVE EAST TONIGHT...PASSING OVER NORTHERN LAKE MICHIGAN LATE SATURDAY EVENING WITH A TRAILING COLD FRONT TURNING MODERATE SOUTHERLY WINDS OF 15 TO 25 KT TO NORTHWESTERLY. MOIST FLOW AHEAD OF THE FRONT HAS ALREADY LED TO DENSE FOG OVER MUCH OF THE LAKE WHICH IS EXPECTED TO PERSIST UNTIL THE COLD FRONT PASSES SATURDAY NIGHT. WINDS SHOULD THEN DIMINISH THROUGH THE DAY SUNDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST...BECOMING CENTERED OVER LAKE MICHIGAN ON MONDAY. LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS MONDAY...THEN LIFT NORTHEAST TO LAKE MICHIGAN LATE THURSDAY INTO EARLY FRIDAY. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7 PM SATURDAY. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870- LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 7 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
128 PM CDT FRI MAY 31 2013 .MESOSCALE DISCUSSION...115 PM CDT INITIAL LOOK AT THE ATMOSPHERE IN PREPARATION OF AFTERNOON/EVENING CONVECTION. SUPPORT FOR WIDESPREAD SEVERE APPEARS TO BE LESS PRONOUNCED THAN EARLIER SIGNALS HAD SUGGESTED. A MINIMA OF 0-6KM BULK SHEAR EXISTS EARLY THIS AFTERNOON ACROSS NORTHCENTRAL/NORTHEAST ILLINOIS STRETCHING INTO NORTHWEST INDIANA. ALONG THE WESTERN PERIPHERY OF THIS MINIMA IS AN AXIS OF MUCH HIGHER SHEAR AROUND 70KTS IN IOWA...TO NEARLY 80KTS STRETCHING SOUTH INTO CENTRAL MISSOURI. VISIBLE IMAGERY SHOWS CONSIDERABLE CLOUD COVER...REMNANTS/BLOWOFF OF EARLIER CONVECTION TO THE SOUTHWEST...LIFTING NORTHEAST ACROSS THE CWFA AT THIS TIME. THIS WILL INHIBIT SFC CAPE FROM GETTING OUT OF CONTROL THROUGH EARLY THIS AFTERNOON...AND TOGETHER WITH THE MARGINAL SHEAR WOULD TEND TO LIMIT THE LOCAL POTENTIAL FOR ORGANIZED CONVECTION OVER THE NEXT FEW HOURS. MORNING CONVECTION IN MISSOURI CORRELATED TO AN AXIS OF LOW LEVEL MOISTURE CONVERGENCE AND A WEAK TROUGH DEPICTED AT 850 MB. LATEST FIELDS FROM THE RAP MODEL SHOW THIS TROUGH AND THE WESTERN FOCUS FOR THIS MOISTURE CONVERGENCE EXPANDING OUT OF THE SAINT LOUIS AREA ACROSS ILLINOIS AND WORKING INTO THE CHICAGO METRO AREA BY LATE AFTERNOON...22Z TO 00Z...WHILE GRADUALLY BECOMING LESS FOCUSED. HI-RES GUIDANCE IS SUGGESTING THAT AS THIS CONVECTION BEGINS TO LIFT THROUGH SW IL...IT WILL EXPAND ALONG A LINE STRETCHING FROM SAINT LOUIS THROUGH BLOOMINGTON TO KANKAKEE AND TOWARD MICHIGAN CITY. A SMALLER AREA OF LATE MORNING AND EARLY AFTERNOON ISOLATED STORMS OVER IOWA ALSO IS NICELY CORRELATED TO AN AXIS OF MOISTURE CONVERGENCE IN THE RAP...BUT WAS MUCH LESS PRONOUNCED AND MIGRATING MORE TO THE NORTH RATHER THAN EAST INTO ILLINOIS. THIS CONVECTION WAS CLOSER TO THE 500MB VORT MAX AND IN AN AREA OF ANTICIPATED STEEPENING LAPSE RATES THROUGHOUT THE AFTN. AS THE TROUGH AXIS SLOWLY SLIDES EAST...SOME OF THIS MAY PUSH INTO NORTHWEST IL BUT MAY NOT HAVE THE LONGEVITY TO CONTINUE ACROSS NORTHCENTRAL/NORTHEAST IL. BEACHLER/LENNING && .DISCUSSION... 328 AM...MAIN FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS/TIMING THROUGH SATURDAY EVENING ALONG WITH POTENTIAL FOR SEVERE WEATHER AND HEAVY RAIN/FLOODING. WAVE OF SHOWERS WITH SOME EMBEDDED THUNDER WILL CONTINUE LIFTING NORTHEAST AWAY FROM THE AREA EARLY THIS MORNING WITH SUBSIDENCE INTO THE MID MORNING HOURS EXPECTED TO BRING SEVERAL HOURS OF DRY WEATHER. ATTENTION THEN SHIFTS TO CONVECTION OVER NORTHEAST KANSAS/NORTHWEST MISSOURI. MOST RECENT HRRR/RAP GUIDANCE SEEMS IN BETTER AGREEMENT WITH 00Z SUITE OF MODELS SHOWING THIS ACTIVITY SPREADING EAST/NORTHEAST AS THE MAIN SHORTWAVE LIFTS NORTHEAST... THEN SUGGESTS RAPID DEVELOPMENT ACROSS WESTERN AND NORTH CENTRAL IL THIS AFTERNOON...PERHAPS EARLY THIS AFTERNOON. HOWEVER... THERE STILL REMAINS SOME UNCERTAINTY REGARDING WHERE CONVECTION DEVELOPS AND WHETHER IT AFFECTS ALL OR PART OF THE CWA. CONFIDENCE INCREASES ACROSS THE SOUTHERN HALF/TWO THIRDS OF THE AREA. WITH THE EXPECTATION THAT THIS MORNING WILL END UP BEING MAINLY DRY AND EVENTUALLY PARTLY/MOSTLY SUNNY...TEMPS REACHING LOWER 80S SEEMS ON TRACK ALONG WITH DEWPOINTS REBOUNDING BACK INTO THE MID/UPPER 60S. SUFFICIENT SHEAR AND STRONG LAPSE RATES COMBINED WITH THE VERY MOIST/UNSTABLE LOW LEVELS WILL SUPPORT SEVERE WEATHER ACROSS THE ENTIRE AREA WITH THE MAIN THREAT APPEARING TO BE DAMAGING WINDS WITH ASSOCIATED LINES/BOWING SEGMENTS. THOUGH LARGE HAIL WITH STRONGER CORES AND ISOLATED TORNADOES WILL REMAIN POSSIBLE. CONVECTION WILL THEN SHIFT EAST THIS EVENING/OVERNIGHT. AS THE UPPER TROUGH MOVES CLOSER TO THE WESTERN LAKES SATURDAY...ANOTHER WAVE IS EXPECTED TO LIFT NORTHEAST SATURDAY BUT LIKELY BE A LITTLE FURTHER EAST WITH CONVECTION LIKELY AFFECTING MAINLY EASTERN IL AND NORTHWEST INDIANA...PERHAPS ALONG/EAST OF THE I-55 OR I-57 CORRIDORS. SEVERE WEATHER WILL ONCE AGAIN BE POSSIBLE SATURDAY AFTERNOON INTO SATURDAY EVENING. NO CHANGES PLANNED TO THE FLASH FLOOD WATCH WHICH IS IN EFFECT FOR THE ENTIRE AREA THROUGH SATURDAY EVENING. FORECAST STORM TOTAL RAINFALL...FROM THIS MORNING THROUGH SATURDAY EVENING...RANGES FROM ABOUT AN INCH NEAR THE WI/IL BORDER TO 2-2.5 INCHES FROM A CHICAGO/PERU LINE SOUTH. SOME AREAS WILL LIKELY SEE LESS AND SOME AREAS MAY SEE MORE. INDIVIDUAL STORM MOTION WILL PROBABLY BE FAST ENOUGH THAT WHILE HEAVY/TORRENTIAL RAIN WILL FALL...ITS DURATION COULD BE SHORT. BUT IF THE STORMS BEGIN TO TRAIN OVER THE SAME AREAS...WITH RAINFALL RATES OF 1 TO 2+ INCHES/HOUR...ON ALREADY SATURATED GROUND...THEN FLASH FLOODING MAY BE POSSIBLE. AS THE UPPER TROUGH/SURFACE LOW FINALLY DEPART SUNDAY...ONE LAST WAVE PIVOTING AROUND THE WESTERN LAKES COULD PRODUCE SOME SHOWERS SUNDAY MORNING. BROAD BUT WEAK HIGH PRESSURE THEN BUILDS ACROSS THE LAKES SUNDAY AFTERNOON THROUGH MONDAY WITH A SHOT OF COOLER AIR. WHILE HIGHS ON SUNDAY ARE ONLY EXPECTED TO BE IN THE 60S...LOWER 70S SOUTH...WINDS WILL TURN OFF THE LAKE SUNDAY AFTERNOON...THUS COOLER/FALLING TEMPS AT THE LAKE SUNDAY AFTERNOON. LOWS THEN DROP INTO THE 40S IN MANY AREAS MONDAY MORNING AND POSSIBLY TUESDAY MORNING AS WELL. SEVERAL DAYS OF EASTERLY WINDS WILL KEEP THE LAKE SHORE AREAS COOLER NEXT WEEK. PATTERN APPEARS TO TURN MORE ACTIVE AGAIN TUESDAY INTO WEDNESDAY AS ANOTHER SLOW MOVING UPPER LOW TRACKS ACROSS THE PLAINS THOUGH ITS STILL FAIRLY EARLY TO DETERMINE WHERE AND WHEN THIS LOW WILL MOVE THOUGH HAVE INCLUDED CHANCE POPS INTO MID/LATE WEEK AS THIS NEXT SYSTEM POTENTIALLY APPROACHES. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * GUSTY S WINDS EXPECTED THIS AFTN WITH A BRIEF PERIOD OF SSE WINDS PSBL BEHIND TSRA. * BRIEF PERIOD OF TSRA THIS AFTN WITH MVFR VSBY PSBL. * SHRA EXPECTED BEHIND TSRA WITH SCT SHOWERS OVERNIGHT. * ANOTHER ROUND OF TSRA/SHRA EXPECTED TOMORROW AFTN. JEE //DISCUSSION...UPDATED 18Z... THE ACTIVE PERIOD CONTINUES BUT THERE IS VERY HIGH UNCERTAINTY REGARDING WHERE AND WHEN CONVECTION WILL OCCUR TODAY. TEMPS HAVE CLIMBED INTO THE 70S WITH DEWPOINTS IN THE 60S WHICH SUGGESTS FAVORABLE CONDITIONS. A LOW PRESSURE SYSTEM IS OVER SOUTH DAKOTA AND A LEFT OVER CONVECTIVE SYSTEM IS OVER NE MO/SE IA/W IL. SHOWERS ARE SLOWLY MOVING NORTHEAST WITH A FEW CONVECTIVE CELLS FORMING OVER FORD COUNTY IL IN THE LAST FEW MINUTES. EXPECTING THUNDERSTORMS TO DEVELOP ACROSS NORTH CENTRAL IL AND PUSH EAST THROUGH THE EASTERN TERMINALS. SINCE THE AXIS OF BEST INSTABILITY IS EAST OF RFD...KEPT TS OUT OF RFD. THAT BEING SAID RFD MAY SEE A FEW STRAY SHOWERS OVER THE NEXT FEW HOURS. GUSTY S WINDS ARE EXPECTED BUT MAY SEE A BRIEF SHIFT TO SSE WINDS BEHIND THE THUNDERSTORMS. EXPECTING A NARROW WINDOW OF TSRA OF ABOUT AN HOUR...FOLLOWED BY SHOWERS. THE AREA WILL REMAIN UNSTABLE OVERNIGHT WITH SCATTERED SHOWERS EXPECTED OVERNIGHT. ANOTHER ROUND OF TSRA AND SHOWERS IS EXPECTED LATE SATURDAY AFTERNOON/EARLY AS THE LOW PRESSURE SYSTEM PASSES TO THE NORTH AND ITS COLD FRONT APPROACHES FROM THE WEST. STRONG S WINDS ARE ONCE AGAIN EXPECTED TOMORROW...BUT GUSTS WILL NOT BE AS STRONG. JEE //ORD AND MDW CONFIDENCE...UPDATED 18Z... * HIGH CONFIDENCE IN PRECIP AFFECTING THE AIRPORTS THIS AFTERNOON. * LOW CONFIDENCE IN TIMING AND DURATION. * LOW CONFIDENCE IN SHRA COVERAGE TONIGHT. * MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA TOMORROW AFTERNOON. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE. SUNDAY...SLT CHC OF MORNING SHRA. MONDAY...VFR LIKELY. TUESDAY...CHC OF MORNING MVFR. WEDNESDAY & THURSDAY...CHC OF TSRA. MTF && .MARINE... 230 AM CDT ANOMALOUSLY DEEP LOW PRESSURE ACROSS THE DAKOTAS WILL CONTINUE SOUTHERLY FLOW ACROSS THE LAKE. THE STABLE MARINE LAYER WILL KEEP WINDS FROM BECOMING TOO GUSTY...ALTHOUGH NEARSHORE AREAS OF IL AND IN WILL LIKELY BE CLOSE TO SMALL CRAFT CRITERION WINDS GIVEN THE OFFSHORE COMPONENT. PERIODS OF STORMS ARE LIKELY ACROSS THE LAKE THROUGH TONIGHT AND POSSIBLY INTO SATURDAY. THE SYSTEM WILL SWING A COLD FRONT ACROSS THE LAKE LATE SATURDAY NIGHT ALLOWING FOR A WIND SHIFT TO NORTHWEST. THESE WINDS WILL TURN NORTHERLY ON SUNDAY AND GRADUALLY DIMINISH INTO MONDAY AS HIGH PRESSURE BUILDS OVER THE LAKE. THIS HIGH WILL SLOWLY SHIFT EAST THROUGH MIDWEEK...BUT CONTINUE TO STRENGTHEN SO THE RETURN FLOW INFLUENCE LOOKS TO BE SLOW TO SPREAD ACROSS THE LAKE. THIS SHOULD OFFER A FAIRLY QUIET MARINE PERIOD FROM SUN-THU. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7 PM SATURDAY. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870- LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 7 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
116 PM CDT FRI MAY 31 2013 .MESOSCALE DISCUSSION... 115 PM CDT INITIAL LOOK AT THE ATMOSPHERE IN PREPARATION OF AFTERNOON/EVENING CONVECTION. SUPPORT FOR WIDESPREAD SEVERE APPEARS TO BE LESS PRONOUNCED THAN EARLIER SIGNALS HAD SUGGESTED. A MINIMA OF 0-6KM BULK SHEAR EXISTS EARLY THIS AFTERNOON ACROSS NORTHCENTRAL/NORTHEAST ILLINOIS STRETCHING INTO NORTHWEST INDIANA. ALONG THE WESTERN PERIPHERY OF THIS MINIMA IS AN AXIS OF MUCH HIGHER SHEAR AROUND 70KTS IN IOWA...TO NEARLY 80KTS STRETCHING SOUTH INTO CENTRAL MISSOURI. VISIBLE IMAGERY SHOWS CONSIDERABLE CLOUD COVER...REMNANTS/BLOWOFF OF EARLIER CONVECTION TO THE SOUTHWEST...LIFTING NORTHEAST ACROSS THE CWFA AT THIS TIME. THIS WILL INHIBIT SFC CAPE FROM GETTING OUT OF CONTROL THROUGH EARLY THIS AFTERNOON...AND TOGETHER WITH THE MARGINAL SHEAR WOULD TEND TO LIMIT THE LOCAL POTENTIAL FOR ORGANIZED CONVECTION OVER THE NEXT FEW HOURS. MORNING CONVECTION IN MISSOURI CORRELATED TO AN AXIS OF LOW LEVEL MOISTURE CONVERGENCE AND A WEAK TROUGH DEPICTED AT 850 MB. LATEST FIELDS FROM THE RAP MODEL SHOW THIS TROUGH AND THE WESTERN FOCUS FOR THIS MOISTURE CONVERGENCE EXPANDING OUT OF THE SAINT LOUIS AREA ACROSS ILLINOIS AND WORKING INTO THE CHICAGO METRO AREA BY LATE AFTERNOON...22Z TO 00Z...WHILE GRADUALLY BECOMING LESS FOCUSED. HI-RES GUIDANCE IS SUGGESTING THAT AS THIS CONVECTION BEGINS TO LIFT THROUGH SW IL...IT WILL EXPAND ALONG A LINE STRETCHING FROM SAINT LOUIS THROUGH BLOOMINGTON TO KANKAKEE AND TOWARD MICHIGAN CITY. A SMALLER AREA OF LATE MORNING AND EARLY AFTERNOON ISOLATED STORMS OVER IOWA ALSO IS NICELY CORRELATED TO AN AXIS OF MOISTURE CONVERGENCE IN THE RAP...BUT WAS MUCH LESS PRONOUNCED AND MIGRATING MORE TO THE NORTH RATHER THAN EAST INTO ILLINOIS. THIS CONVECTION WAS CLOSER TO THE 500MB VORT MAX AND IN AN AREA OF ANTICIPATED STEEPENING LAPSE RATES THROUGHOUT THE AFTN. AS THE TROUGH AXIS SLOWLY SLIDES EAST...SOME OF THIS MAY PUSH INTO NORTHWEST IL BUT MAY NOT HAVE THE LONGEVITY TO CONTINUE ACROSS NORTHCENTRAL/NORTHEAST IL. BEACHLER/LENNING && .DISCUSSION... 328 AM...MAIN FORECAST CONCERN AND CHALLENGE REMAINS CONVECTIVE TRENDS/TIMING THROUGH SATURDAY EVENING ALONG WITH POTENTIAL FOR SEVERE WEATHER AND HEAVY RAIN/FLOODING. WAVE OF SHOWERS WITH SOME EMBEDDED THUNDER WILL CONTINUE LIFTING NORTHEAST AWAY FROM THE AREA EARLY THIS MORNING WITH SUBSIDENCE INTO THE MID MORNING HOURS EXPECTED TO BRING SEVERAL HOURS OF DRY WEATHER. ATTENTION THEN SHIFTS TO CONVECTION OVER NORTHEAST KANSAS/NORTHWEST MISSOURI. MOST RECENT HRRR/RAP GUIDANCE SEEMS IN BETTER AGREEMENT WITH 00Z SUITE OF MODELS SHOWING THIS ACTIVITY SPREADING EAST/NORTHEAST AS THE MAIN SHORTWAVE LIFTS NORTHEAST... THEN SUGGESTS RAPID DEVELOPMENT ACROSS WESTERN AND NORTH CENTRAL IL THIS AFTERNOON...PERHAPS EARLY THIS AFTERNOON. HOWEVER... THERE STILL REMAINS SOME UNCERTAINTY REGARDING WHERE CONVECTION DEVELOPS AND WHETHER IT AFFECTS ALL OR PART OF THE CWA. CONFIDENCE INCREASES ACROSS THE SOUTHERN HALF/TWO THIRDS OF THE AREA. WITH THE EXPECTATION THAT THIS MORNING WILL END UP BEING MAINLY DRY AND EVENTUALLY PARTLY/MOSTLY SUNNY...TEMPS REACHING LOWER 80S SEEMS ON TRACK ALONG WITH DEWPOINTS REBOUNDING BACK INTO THE MID/UPPER 60S. SUFFICIENT SHEAR AND STRONG LAPSE RATES COMBINED WITH THE VERY MOIST/UNSTABLE LOW LEVELS WILL SUPPORT SEVERE WEATHER ACROSS THE ENTIRE AREA WITH THE MAIN THREAT APPEARING TO BE DAMAGING WINDS WITH ASSOCIATED LINES/BOWING SEGMENTS. THOUGH LARGE HAIL WITH STRONGER CORES AND ISOLATED TORNADOES WILL REMAIN POSSIBLE. CONVECTION WILL THEN SHIFT EAST THIS EVENING/OVERNIGHT. AS THE UPPER TROUGH MOVES CLOSER TO THE WESTERN LAKES SATURDAY...ANOTHER WAVE IS EXPECTED TO LIFT NORTHEAST SATURDAY BUT LIKELY BE A LITTLE FURTHER EAST WITH CONVECTION LIKELY AFFECTING MAINLY EASTERN IL AND NORTHWEST INDIANA...PERHAPS ALONG/EAST OF THE I-55 OR I-57 CORRIDORS. SEVERE WEATHER WILL ONCE AGAIN BE POSSIBLE SATURDAY AFTERNOON INTO SATURDAY EVENING. NO CHANGES PLANNED TO THE FLASH FLOOD WATCH WHICH IS IN EFFECT FOR THE ENTIRE AREA THROUGH SATURDAY EVENING. FORECAST STORM TOTAL RAINFALL...FROM THIS MORNING THROUGH SATURDAY EVENING...RANGES FROM ABOUT AN INCH NEAR THE WI/IL BORDER TO 2-2.5 INCHES FROM A CHICAGO/PERU LINE SOUTH. SOME AREAS WILL LIKELY SEE LESS AND SOME AREAS MAY SEE MORE. INDIVIDUAL STORM MOTION WILL PROBABLY BE FAST ENOUGH THAT WHILE HEAVY/TORRENTIAL RAIN WILL FALL...ITS DURATION COULD BE SHORT. BUT IF THE STORMS BEGIN TO TRAIN OVER THE SAME AREAS...WITH RAINFALL RATES OF 1 TO 2+ INCHES/HOUR...ON ALREADY SATURATED GROUND...THEN FLASH FLOODING MAY BE POSSIBLE. AS THE UPPER TROUGH/SURFACE LOW FINALLY DEPART SUNDAY...ONE LAST WAVE PIVOTING AROUND THE WESTERN LAKES COULD PRODUCE SOME SHOWERS SUNDAY MORNING. BROAD BUT WEAK HIGH PRESSURE THEN BUILDS ACROSS THE LAKES SUNDAY AFTERNOON THROUGH MONDAY WITH A SHOT OF COOLER AIR. WHILE HIGHS ON SUNDAY ARE ONLY EXPECTED TO BE IN THE 60S...LOWER 70S SOUTH...WINDS WILL TURN OFF THE LAKE SUNDAY AFTERNOON...THUS COOLER/FALLING TEMPS AT THE LAKE SUNDAY AFTERNOON. LOWS THEN DROP INTO THE 40S IN MANY AREAS MONDAY MORNING AND POSSIBLY TUESDAY MORNING AS WELL. SEVERAL DAYS OF EASTERLY WINDS WILL KEEP THE LAKE SHORE AREAS COOLER NEXT WEEK. PATTERN APPEARS TO TURN MORE ACTIVE AGAIN TUESDAY INTO WEDNESDAY AS ANOTHER SLOW MOVING UPPER LOW TRACKS ACROSS THE PLAINS THOUGH ITS STILL FAIRLY EARLY TO DETERMINE WHERE AND WHEN THIS LOW WILL MOVE THOUGH HAVE INCLUDED CHANCE POPS INTO MID/LATE WEEK AS THIS NEXT SYSTEM POTENTIALLY APPROACHES. CMS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 16Z... * S WINDS GUSTING TO ARND 25 KT THROUGH THE DAY. * SHOWERS AND THUNDERSTORMS EXPECTED AGAIN THIS AFTN. * BEST CHANCE FOR TSRA IS IN THE MID AFTN...WITH STRONG TO SEVERE STORMS PSBL. JEE //DISCUSSION...UPDATED 12Z... A BREAK IN CONVECTION WILL BE OVER THE AREA THROUGH THE REMAINDER OF THE MORNING RUSH. LINGERING MVFR CIGS FROM LAST NIGHTS RAIN HAVE MAINLY DISSIPATED AND/OR SHIFTED EAST...SO THE MAIN CONCERN CENTERS ON TIMING THE STORM CHANCES. OUR CONVECTIVE POTENTIAL LOOKS TO BEGIN FROM ONGOING STORMS IN MISSOURI...WHETHER IT BE FROM THE COMPLEX ITSELF EVOLVING NORTHEAST OR SOME OFFSHOOT OF IT. THE STRONGEST CONVECTION MAY END UP REMAINING SOUTH OF THE TERMINALS...AT LEAST AT FIRST. BY MID-AFTERNOON...RE-ENHANCEMENT OF STORMS BOTH IN COVERAGE AND IN MAGNITUDE IS EXPECTED IMMEDIATELY AHEAD OF THE DECAYING SYSTEM AND ITS FORCING. WHETHER THAT WILL BE FAR ENOUGH NORTH TO IMPACT ORD AND THE OTHER TAF SITES WITH HEAVY CONVECTION IS TOO CHALLENGING TO TELL FOR SURE YET...BUT IT DOES LOOK LIKE IT SHOULD BE AT LEAST CLOSE. SO HAVE PRESERVED THE PREVAILING THUNDER AT THE MOST FAVORED TIME WINDOWS...BUT ITS POSSIBLE IT HAPPENS BEFORE AND/OR AFTER THIS DEPENDING ON NUMEROUS FACTORS. THIS IS ALWAYS A CHALLENGE WITH ONGOING EARLY MORNING CONVECTION AND HOW IT ALTERS THE ATMOSPHERE. SOUTHERLY WINDS ARE LIKELY TO BEGIN GUSTING BY MID-MORNING WITH GUSTS TO NEAR 25 KT AT TIMES. STORM WINDS AND RAIN-COOLED OUTFLOW COULD LEAD TO STRONGER WIND GUSTS AND VARIABILITY IN DIRECTION IF THEY WERE TO PASS OVER THE AIRFIELDS. //ORD AND MDW CONFIDENCE...UPDATED 16Z... * HIGH CONFIDENCE IN SHRA/TSRA DVLPG. * MEDIUM CONFIDENCE IN TIMING OF SHRA/TSRA. * HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS. JEE //OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z... SATURDAY NIGHT...CHC OF SHRA DURING THE EVE. MVFR POSSIBLE. SUNDAY...SLT CHC OF MORNING SHRA. MONDAY...VFR LIKELY. TUESDAY...CHC OF MORNING MVFR. WEDNESDAY & THURSDAY...CHC OF TSRA. MTF && .MARINE... 230 AM CDT ANOMALOUSLY DEEP LOW PRESSURE ACROSS THE DAKOTAS WILL CONTINUE SOUTHERLY FLOW ACROSS THE LAKE. THE STABLE MARINE LAYER WILL KEEP WINDS FROM BECOMING TOO GUSTY...ALTHOUGH NEARSHORE AREAS OF IL AND IN WILL LIKELY BE CLOSE TO SMALL CRAFT CRITERION WINDS GIVEN THE OFFSHORE COMPONENT. PERIODS OF STORMS ARE LIKELY ACROSS THE LAKE THROUGH TONIGHT AND POSSIBLY INTO SATURDAY. THE SYSTEM WILL SWING A COLD FRONT ACROSS THE LAKE LATE SATURDAY NIGHT ALLOWING FOR A WIND SHIFT TO NORTHWEST. THESE WINDS WILL TURN NORTHERLY ON SUNDAY AND GRADUALLY DIMINISH INTO MONDAY AS HIGH PRESSURE BUILDS OVER THE LAKE. THIS HIGH WILL SLOWLY SHIFT EAST THROUGH MIDWEEK...BUT CONTINUE TO STRENGTHEN SO THE RETURN FLOW INFLUENCE LOOKS TO BE SLOW TO SPREAD ACROSS THE LAKE. THIS SHOULD OFFER A FAIRLY QUIET MARINE PERIOD FROM SUN-THU. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7 PM SATURDAY. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565- LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ868-LMZ870- LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM SATURDAY. SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 7 PM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
232 AM CDT FRI MAY 31 2013 .DISCUSSION... 504 PM CDT HAVE DECIDED TO EXPAND THE CURRENT FLASH FLOOD WATCH...TO INCLUDE THE ENTIRE CWA. WAS ON THE FENCE EARLIER WITH REGARDS TO EXPANDING THE CURRENT FLASH FLOOD WATCH FOR THE REMAINDER OF THE CWA...BUT WITH LATEST TRENDS THIS PAST AFTERNOON...HAVE DECIDED TO INCLUDE THE ENTIRE CWA. THE THUNDERSTORMS THIS PAST AFTERNOON HAVE BEEN VERY GOOD RAIN PRODUCERS...WHICH WILL LIKELY CONTINUE OVER THE NEXT COUPLE OF HOURS AS PWATS REMAIN RATHER HIGH. ALSO...MONITORING THE CONVECTIVE LINE TO THE WEST AND ITS MOVEMENT EAST INTO THE CWA. LATEST TRENDS AND SHORT TERM GUIDANCE ARE HINTING AT THE POSSIBILITY OF MORE TRAINING ACROSS THE CWA...WITH CURRENT FLOW IN PLACE...DEFINITELY SEEMS REASONABLE. RODRIGUEZ //PREV DISCUSSION... 400 PM CDT MAIN FORECAST CONCERNS REMAIN TIED TO THE ACTIVE WEATHER PATTERN EXPECTED THROUGH THE START OF THE WEEKEND...WITH ROUNDS OF HEAVY RAINFALL LIKELY AS WELL AS CONTINUED CHANCES FOR SEVERE WEATHER. HAVE NOT EXPANDED THE FFA WATCH AT THIS TIME WITH MORE WIDESPREAD HEAVY RAINFALL AND FLOODING NOT APPEARING LIKELY UNTIL LATER FRIDAY AFTERNOON INTO FRIDAY NIGHT. THIS IS NOT TO SAY THAT LOCALIZED FLOODING COULD NOT OCCUR WITH ANY POSSIBLE STRONG THUNDERSTORMS TONIGHT. A MORE LIKELY SCENARIO AT THIS TIME IS WITH THE CURRENT SCATTERED DEVELOPMENT TO BE REPLACED WITH A MORE PROGRESSIVE AREA OF THUNDERSTORMS. CURRENT ISOLATED TO SCATTERED ACTIVITY ACROSS THE CWA WILL CONTINUE TO INCREASE IN COVERAGE THIS EVENING...AS LARGE SCALE FORCING INCREASES WITH THE APPROACH A FAIRLY STOUT MID LEVEL WAVE PROPAGATING NORTH THROUGH CENTRAL ILLINOIS. AREAS WHICH CONTINUE TO BE FAVORED ARE LOCATIONS ALONG AND WEST OF A LINE FROM CRYSTAL LAKE SOUTH TO GIBSON CITY IN ILLINOIS. LATEST RAP ANALYSIS SHOWS MODERATE INSTABILITY IN PLACE WITH MLCAPE AROUND 2000 J/KG...AND WITH MID/LOW LEVEL LAPSE RATES EXPECTED TO ONLY INCREASE OVER THE NEXT COUPLE OF HOURS. THIS INCREASING FORCING AND INSTABILITY WILL AID FURTHER DEVELOPMENT/EXPANSION OF CURRENT ACTIVITY ONGOING ACROSS THE WESTERN HALF OF THE CWA. DEEP LAYER SHEAR REMAINS MEAGER AT 25-30KT PRIMARILY OVER THE WESTERN CWA WHILE 0-1KM SHEAR ALSO REMAINS HIGHEST ALONG OR JUST WEST OF THE CWA...ESPECIALLY GOING INTO WESTERN ILLINOIS AND EASTERN IOWA. HOWEVER...SHORT TERM GUIDANCE CONTINUES TO SHOW AN INCREASE IN BOTH DEEP LAYER SHEAR AND LOW LEVEL SHEAR ACROSS THE CURRENT WATCH AREA THROUGH THE REMAINDER OF THE AFTERNOON. THIS WILL HELP FOR MORE ORGANIZED AND LONGER LIVED DEVELOPMENT ACROSS THE WESTERN CWA...LEAVING THE THREAT OF HAIL/DAMAGING WINDS AS WELL AS POSSIBLE TORNADOES. ALTHOUGH MORE ORGANIZED DEVELOPMENT IS MORE LIKELY FOR THE WESTERN HALF OF THE CWA...SHORT TERM GUIDANCE IS HINTING AT A SLIGHT INCREASE IN DEEP LAYER SHEAR MORE TOWARDS FAR NORTHEAST ILLINOIS. THIS SLIGHT INCREASE COINCIDING WITH THE CURRENT CAPE IN PLACE...COULD FAVOR SOME ISOLATED STRONGER DEVELOPMENT IN THAT LOCATION IN THE NEXT COUPLE OF HOURS. WILL NEED CONTINUE TO MONITOR DEVELOPMENT IN THAT LOCATION...WHICH WOULD INCLUDE THE CITY OF CHICAGO/METRO AREA LATE THIS AFTERNOON INTO THE EARLY EVENING...AS I COULD EASILY FORESEE AN UPSCALE IN GROWTH IN BOTH INTENSITY AND COVERAGE. EVEN IF THAT DOES NOT MATERIALIZE THROUGH LATE THIS AFTERNOON...CONTINUE TO MONITOR A LARGER LINE OF THUNDERSTORMS SITUATED FROM SOUTHERN IOWA SOUTH INTO MISSOURI. THIS LINE IS TIED MORE CLOSELY TO FAIRLY STRONG MID LEVEL WAVE LIFTING NORTHEAST OUT KANSAS AND ATTENDANT SURFACE TROUGH/BOUNDARY FROM IOWA INTO MISSOURI. ALL GUIDANCE IS SHOWING THIS LINE OF THUNDERSTORMS WILL INCREASE IN INTENSITY OVER THE NEXT COUPLE OF HOURS...WHICH WOULD MAKE SENSE AS THIS LINE OF THUNDERSTORMS MOVES FURTHER EAST/NORTHEAST INTO A MORE UNSTABLE ENVIRONMENT. STRONG FORCING OWING TO LARGE SCALE SUPPORT AND LOW/MID LEVEL CONVERGENCE SHOULD AID IN THIS LINE OF THUNDERSTORMS FURTHER BLOSSOMING AS IT MOVES TOWARDS THE WESTERN ILLINOIS...ESPECIALLY AS DEEP LAYER SHEAR IS ALSO INCREASING. THERE IS STILL SOME UNCERTAINTY AS TO THE WHOLE EVOLUTION OF THIS LINE OF THUNDERSTORMS AS IT WORKS ITS WAY TOWARDS NORTHERN ILLINOIS THIS EVENING...MAINLY IN THE STRENGTH OF THIS COMPLEX AND POTENTIAL SEVERE THREAT. ALTHOUGH THERE WILL BE SOME SLIGHT DIMINISHING TREND WITH THE CURRENT INSTABILITY IN PLACE...FEEL THAT IT WILL MORE THAN SUFFICE TO HELP KEEP THIS LINE SHIFTING EAST. ALSO...SHORT TERM GUIDANCE IS INDICATING THAT 0-3KM BULK SHEAR WILL INCREASE TOWARDS THE 00Z TIME FRAME THIS EVENING...WHICH WOULD ACT TO HELP FOR ORGANIZATION AND INCREASE IN THREAT FOR LINEAR STRUCTURES/STRONG DAMAGING WINDS. SO HAVE TRENDED MORE PESSIMISTIC...WITH THINKING THAT THIS LINE AND STRONG DAMAGING WINDS COULD MOVE ACROSS NORTHERN ILLINOIS THIS EVENING. HAVE ALSO TRENDED MORE TOWARDS THE HRRR...WITH SYSTEM TIMING THINKING THAT IT SHOULD BE KNOCKING ON THE WESTERN CWA DOORSTEPS BY 00-01Z AND THEN CONTINUE EAST TOWARDS NORTHEAST ILLINOIS THROUGH THE SEVERAL HOURS THERE AFTER. BEYOND THAT TIME FRAME...CONFIDENCE LOWERS WITH REGARDS TO THE STRENGTH OF THIS SYSTEM. NONETHELESS...HEAVY RAINFALL AND FLASH FLOODING COULD BECOME ISSUES OVERNIGHT TONIGHT ESPECIALLY AS PWATS ARE AT OR JUST ABOVE 1.7 INCHES AND 850MB DEW POINTS REMAIN RATHER HIGH. THUNDERSTORM COMPLEX IS THEN EXPECTED TO SHIFT EAST OF THE CWA BY EARLY FRIDAY MORNING...WITH A DRYING TREND EXPECTED DURING THAT TIME FRAME. THIS SHOULD NOT LAST TOO LONG WITH DRY CONDITIONS ONLY EXPECTED THROUGH MID DAY AS ATTENTION QUICKLY SHIFTS BACK WEST WITH THE APPROACH OF ANOTHER STRONG MID LEVEL WAVE EJECTING OUT OF THE CENTRAL PLAINS. YET AGAIN...A SEVERE THREAT WILL BE IN PLACE ON FRIDAY WITH GROWING CONCERNS OF MORE POTENTIAL FLOODING FROM THIS POINT ON...INTO FRIDAY NIGHT AND SATURDAY. THE SEVERE THREAT WILL LIKELY AFFECT THE ENTIRE CWA ON FRIDAY AND WITH CLEARING ANTICIPATED FRIDAY MORNING...INSTABILITY IS EXPECTED TO RAPIDLY INCREASE BY LATE MORNING WITH MODERATE TO STRONG INSTABILITY LIKELY IN PLACE ACROSS THE CWA. STRONG DEEP LAYER SHEAR IN UPWARDS OF 50-60KT WILL EASILY SUPPORT WIDESPREAD ORGANIZED DEVELOPMENT AS SOON AS EARLY AFTERNOON ON FRIDAY. STRONG DAMAGING WINDS AND HAIL ARE THE MAIN THREAT...BUT WITH SREF GUIDANCE INDICATING ELEMENTS CORRESPONDING TO SUPERCELLULAR STRUCTURES OR ROTATING THUNDERSTORMS COULD COME TOGETHER ACROSS THE CWA. WILL NEED TO CONTINUE TO MONITOR THIS TIME FRAME AS WELL...AS WIDESPREAD SEVERE IS APPEARING LIKELY ONCE AGAIN. GOING INTO FRIDAY NIGHT...HEAVY RAINFALL APPEARS LIKELY WITH SEVERAL STRONG WAVES PROPAGATING NORTHEAST ACROSS THE CWA PROVIDING CONTINUED DEVELOPMENT AS WELL AS A STRONG LLJ ORIENTED TOWARDS NORTHEAST ILLINOIS...PUMPING HIGH THETAE AIR INTO THE REGION. RODRIGUEZ EXTENDED PERIOD...SUNDAY THROUGH THURSDAY... BY DAYBREAK SUNDAY THE UPPER RIDGE IS TO HAVE PROGRESSED EASTWARD TO OVER THE UPPER MIDWEST AND MID MS VALLEY WITH A SURFACE TROUGH/SECONDARY COLD FRONT JUST TO THE NORTHWEST AND NORTH OF THE LOCAL FORECAST AREA. THIS TROUGH/FRONT IS PROGGED TO MOVE ACROSS ALL OF THE FA DURING THE SUNDAY MORNING AS THE UPPER TROUGH CONTINUES ON TO OVER THE UPPER GREAT LAKES AND LOWER OH VALLEY BY EVENING. UNTIL THE TROUGH AXIS MOVES A BIT FURTHER EAST OF THE IMMEDIATE AREA THERE WILL BE A LINGERING CHANCE OF SHOWERS DURING SUNDAY MORNING. THE SECONDARY COLD FRONT WILL REINFORCE THE COLD AIR ADVECTION THAT WILL HAVE STARTED TO OCCUR LATE SATURDAY AND SATURDAY NIGHT WITH THE INITIAL COLD FRONT. BETWEEN THE PAIR OF FRONT 850HPA TEMPERATURES ARE PROGGED TO FALL AROUND 10 DEGREES C FROM 18Z SATURDAY TO 00Z MONDAY......DOWN TO AROUND +4 OR +5C. WITH COOL HIGH PRESSURE BUILDING OVER THE AREA TEMPERATURES WILL BE COOL SUNDAY AND MONDAY WITH HIGHS ONLY IN THE 60S...WITH LAKESIDE MAX TEMPERATURES LIKELY TO ONLY BE IN THE 55-60F RANGE AS A LONG FETCH DOWN LAKE MICHIGAN BRINGS AIR ADDITIONALLY COOLED BY THE STILL CHILLY LAKE ASHORE SUNDAY. WHILE THE SURFACE RIDGE AXIS WILL BE MOVING OVER WI AND WESTERN IL DURING MONDAY ALLOWING WINDS TO SLACKEN...A WEAK NE SYNOPTIC FLOW WILL STILL BE IN PLACE AIDED BY A LAKE BREEZE. THE FURTHER EASTWARD PROGRESS OF THE UPPER TROUGH IS TO BE SLOW AS A CLOSED LOW TO FORM OVER SOUTHERN HUDSON BAY/NORTHERN ONTARIO IS PROGGED TO BE DROP SOUTH...THEN SOUTHEAST AND EAST OVER ONTARIO SATURDAY NIGHT THROUGH MONDAY NIGHT. AS THE UPPER TROUGH/LOW MOVES FURTHER EAST A WEAK UPPER RIDGE WILL MOVE OVER THE REGION TUESDAY AS ANOTHER UPPER LOW MOVES EAST OVER THE FAR SOUTHERN CANADIAN PRAIRIE/FAR NORTHERN PLAINS. THIS WILL ALLOW A BIT OF MODERATION IN TEMPERATURES TUESDAY AND WEDNESDAY AS EAST-SOUTHEAST WINDS BECOMES SOUTHEASTERLY AND INCREASING THOUGH THIS LOW LEVEL FLOW WILL KEEP THE IL SHORE...ESPECIALLY THE FAR NORTHERN PART....STILL CHILLY. INLAND AREAS SHOULD PEAK IN THE UPPER 60S AND LOWER 70S TUESDAY... AND A COUPLE DEGREES WARMER WEDNESDAY. WITH CONTINUED WARM AIR ADVECTION AHEAD OF THE APPROACHING UPPER LOW/TROUGH THE WARMING TREND WILL CONTINUE THURSDAY WITH MOST LOCATIONS REACHING THE MID AND UPPER 70S THOUGH THERE WILL STILL BE AN EASTERLY COMPONENT TO THE LOW LEVEL FLOW TO KEEP THE IL SHORELINE IN THE 60S. TRS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SHRA CONTINUING THROUGH 08Z-10Z WITH ONLY A SMALL CHANCE OF THUNDER IN THAT TIME. * SOME SHIFTING IN THE WINDS FROM SE TO SW THROUGH 12Z OR SO BUT GUSTINESS SHOULD ONLY BE SPORADIC. * MVFR FOG POSSIBLE AROUND DAYBREAK. * SOUTHERLY WINDS GUSTING TO AROUND 25 KT DURING THE DAY TODAY. * STORM CHANCES...INCLUDING STRONG POTENTIAL...RETURNING FRI AFTERNOON AND EVE. //DISCUSSION...UPDATED 06Z... PERIODS OF MAINLY SHOWERS...WITH SOME STORMS /ESPECIALLY SOUTH AND EAST TRACON AREAS/...WITH CONTINUE THROUGH 09Z-10Z. THERE IS EXPECTED TO BE A LULL IN PRECIP COVERAGE DURING THE MORNING RUSH BUT THERE STILL MAY BE A FEW SCATTERED SHOWERS. THE RAINS HAVE FURTHER MADE THE LOW-LEVELS MOIST WHICH COULD HELP PATCHY FOG DEVELOPMENT NEAR DAWN. SOUTHERLY WINDS WILL INCREASE AFTER DAYBREAK AS MIXING ENSUES AND SOME STRONG GUSTS TO AROUND 25 KT ARE EXPECTED AGAIN. AS FOR THUNDER CHANCES THIS AFTERNOON AND EVE...IT IS CHALLENGING AND QUITE A BIT IS LIKELY TO DEPEND ON HOW THUNDER ACTIVITY IN EASTERN KS/MO PLAYS OUT EARLY THIS MORNING. IF THIS WORKS INTO IL BY LATE MORNING/EARLY AFTERNOON IT MAY STIFLE SOME OF THE EXPLOSIVE CONVECTIVE DEVELOPMENT THAT COULD OCCUR WITH AS MUCH INSTABILITY AS WILL BE PRESENT. IT ALSO COULD KEEP MUCH OF THE STORM ACTIVITY SOUTH OF THE CHICAGOLAND TERMINALS. THAT SAID...THE CERTAINTY ON HOW THIS EARLY MORNING CONVECTION TO OUR WEST PLAYS OUT IS LOW. WHILE THE SETUP FOR LATER TODAY INTO THIS EVE COULD PRESENT SEVERAL HOURS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN SHOWERS WITH MEDIUM CONFIDENCE IN NO THUNDER OR IFR CONDITIONS IN RAIN. * HIGH CONFIDENCE IN SOUTHERLY WINDS DURING THE DAY WITH MEDIUM CONFIDENCE IN MAGNITUDE OF THE GUSTS. * LOW CONFIDENCE ON TIMING AND DURATION OF AFTERNOON/EVE THUNDERSTORMS. //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 06Z... * SATURDAY...TSRA LIKELY DURING THE DAY WITH A CHANCE OF SHRA DURING THE NIGHT. MVFR CIGS/VIS POSSIBLE. * SUNDAY...CHANCE OF SHRA EARLY...OTRW...VFR. * MONDAY THROUGH EARLY TUESDAY...VFR. WX NIL. * LATE TUESDAY THROUGH WEDNESDAY...CHANCE TSRA/SHRA. MTF && .MARINE... 230 AM CDT ANOMALOUSLY DEEP LOW PRESSURE ACROSS THE DAKOTAS WILL CONTINUE SOUTHERLY FLOW ACROSS THE LAKE. THE STABLE MARINE LAYER WILL KEEP WINDS FROM BECOMING TOO GUSTY...ALTHOUGH NEARSHORE AREAS OF IL AND IN WILL LIKELY BE CLOSE TO SMALL CRAFT CRITERION WINDS GIVEN THE OFFSHORE COMPONENT. PERIODS OF STORMS ARE LIKELY ACROSS THE LAKE THROUGH TONIGHT AND POSSIBLY INTO SATURDAY. THE SYSTEM WILL SWING A COLD FRONT ACROSS THE LAKE LATE SATURDAY NIGHT ALLOWING FOR A WIND SHIFT TO NORTHWEST. THESE WINDS WILL TURN NORTHERLY ON SUNDAY AND GRADUALLY DIMINISH INTO MONDAY AS HIGH PRESSURE BUILDS OVER THE LAKE. THIS HIGH WILL SLOWLY SHIFT EAST THROUGH MIDWEEK...BUT CONTINUE TO STRENGTHEN SO THE RETURN FLOW INFLUENCE LOOKS TO BE SLOW TO SPREAD ACROSS THE LAKE. THIS SHOULD OFFER A FAIRLY QUIET MARINE PERIOD FROM SUN-THU. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7 PM SATURDAY. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
100 AM CDT FRI MAY 31 2013 .DISCUSSION... 504 PM CDT HAVE DECIDED TO EXPAND THE CURRENT FLASH FLOOD WATCH...TO INCLUDE THE ENTIRE CWA. WAS ON THE FENCE EARLIER WITH REGARDS TO EXPANDING THE CURRENT FLASH FLOOD WATCH FOR THE REMAINDER OF THE CWA...BUT WITH LATEST TRENDS THIS PAST AFTERNOON...HAVE DECIDED TO INCLUDE THE ENTIRE CWA. THE THUNDERSTORMS THIS PAST AFTERNOON HAVE BEEN VERY GOOD RAIN PRODUCERS...WHICH WILL LIKELY CONTINUE OVER THE NEXT COUPLE OF HOURS AS PWATS REMAIN RATHER HIGH. ALSO...MONITORING THE CONVECTIVE LINE TO THE WEST AND ITS MOVEMENT EAST INTO THE CWA. LATEST TRENDS AND SHORT TERM GUIDANCE ARE HINTING AT THE POSSIBILITY OF MORE TRAINING ACROSS THE CWA...WITH CURRENT FLOW IN PLACE...DEFINITELY SEEMS REASONABLE. RODRIGUEZ //PREV DISCUSSION... 400 PM CDT MAIN FORECAST CONCERNS REMAIN TIED TO THE ACTIVE WEATHER PATTERN EXPECTED THROUGH THE START OF THE WEEKEND...WITH ROUNDS OF HEAVY RAINFALL LIKELY AS WELL AS CONTINUED CHANCES FOR SEVERE WEATHER. HAVE NOT EXPANDED THE FFA WATCH AT THIS TIME WITH MORE WIDESPREAD HEAVY RAINFALL AND FLOODING NOT APPEARING LIKELY UNTIL LATER FRIDAY AFTERNOON INTO FRIDAY NIGHT. THIS IS NOT TO SAY THAT LOCALIZED FLOODING COULD NOT OCCUR WITH ANY POSSIBLE STRONG THUNDERSTORMS TONIGHT. A MORE LIKELY SCENARIO AT THIS TIME IS WITH THE CURRENT SCATTERED DEVELOPMENT TO BE REPLACED WITH A MORE PROGRESSIVE AREA OF THUNDERSTORMS. CURRENT ISOLATED TO SCATTERED ACTIVITY ACROSS THE CWA WILL CONTINUE TO INCREASE IN COVERAGE THIS EVENING...AS LARGE SCALE FORCING INCREASES WITH THE APPROACH A FAIRLY STOUT MID LEVEL WAVE PROPAGATING NORTH THROUGH CENTRAL ILLINOIS. AREAS WHICH CONTINUE TO BE FAVORED ARE LOCATIONS ALONG AND WEST OF A LINE FROM CRYSTAL LAKE SOUTH TO GIBSON CITY IN ILLINOIS. LATEST RAP ANALYSIS SHOWS MODERATE INSTABILITY IN PLACE WITH MLCAPE AROUND 2000 J/KG...AND WITH MID/LOW LEVEL LAPSE RATES EXPECTED TO ONLY INCREASE OVER THE NEXT COUPLE OF HOURS. THIS INCREASING FORCING AND INSTABILITY WILL AID FURTHER DEVELOPMENT/EXPANSION OF CURRENT ACTIVITY ONGOING ACROSS THE WESTERN HALF OF THE CWA. DEEP LAYER SHEAR REMAINS MEAGER AT 25-30KT PRIMARILY OVER THE WESTERN CWA WHILE 0-1KM SHEAR ALSO REMAINS HIGHEST ALONG OR JUST WEST OF THE CWA...ESPECIALLY GOING INTO WESTERN ILLINOIS AND EASTERN IOWA. HOWEVER...SHORT TERM GUIDANCE CONTINUES TO SHOW AN INCREASE IN BOTH DEEP LAYER SHEAR AND LOW LEVEL SHEAR ACROSS THE CURRENT WATCH AREA THROUGH THE REMAINDER OF THE AFTERNOON. THIS WILL HELP FOR MORE ORGANIZED AND LONGER LIVED DEVELOPMENT ACROSS THE WESTERN CWA...LEAVING THE THREAT OF HAIL/DAMAGING WINDS AS WELL AS POSSIBLE TORNADOES. ALTHOUGH MORE ORGANIZED DEVELOPMENT IS MORE LIKELY FOR THE WESTERN HALF OF THE CWA...SHORT TERM GUIDANCE IS HINTING AT A SLIGHT INCREASE IN DEEP LAYER SHEAR MORE TOWARDS FAR NORTHEAST ILLINOIS. THIS SLIGHT INCREASE COINCIDING WITH THE CURRENT CAPE IN PLACE...COULD FAVOR SOME ISOLATED STRONGER DEVELOPMENT IN THAT LOCATION IN THE NEXT COUPLE OF HOURS. WILL NEED CONTINUE TO MONITOR DEVELOPMENT IN THAT LOCATION...WHICH WOULD INCLUDE THE CITY OF CHICAGO/METRO AREA LATE THIS AFTERNOON INTO THE EARLY EVENING...AS I COULD EASILY FORESEE AN UPSCALE IN GROWTH IN BOTH INTENSITY AND COVERAGE. EVEN IF THAT DOES NOT MATERIALIZE THROUGH LATE THIS AFTERNOON...CONTINUE TO MONITOR A LARGER LINE OF THUNDERSTORMS SITUATED FROM SOUTHERN IOWA SOUTH INTO MISSOURI. THIS LINE IS TIED MORE CLOSELY TO FAIRLY STRONG MID LEVEL WAVE LIFTING NORTHEAST OUT KANSAS AND ATTENDANT SURFACE TROUGH/BOUNDARY FROM IOWA INTO MISSOURI. ALL GUIDANCE IS SHOWING THIS LINE OF THUNDERSTORMS WILL INCREASE IN INTENSITY OVER THE NEXT COUPLE OF HOURS...WHICH WOULD MAKE SENSE AS THIS LINE OF THUNDERSTORMS MOVES FURTHER EAST/NORTHEAST INTO A MORE UNSTABLE ENVIRONMENT. STRONG FORCING OWING TO LARGE SCALE SUPPORT AND LOW/MID LEVEL CONVERGENCE SHOULD AID IN THIS LINE OF THUNDERSTORMS FURTHER BLOSSOMING AS IT MOVES TOWARDS THE WESTERN ILLINOIS...ESPECIALLY AS DEEP LAYER SHEAR IS ALSO INCREASING. THERE IS STILL SOME UNCERTAINTY AS TO THE WHOLE EVOLUTION OF THIS LINE OF THUNDERSTORMS AS IT WORKS ITS WAY TOWARDS NORTHERN ILLINOIS THIS EVENING...MAINLY IN THE STRENGTH OF THIS COMPLEX AND POTENTIAL SEVERE THREAT. ALTHOUGH THERE WILL BE SOME SLIGHT DIMINISHING TREND WITH THE CURRENT INSTABILITY IN PLACE...FEEL THAT IT WILL MORE THAN SUFFICE TO HELP KEEP THIS LINE SHIFTING EAST. ALSO...SHORT TERM GUIDANCE IS INDICATING THAT 0-3KM BULK SHEAR WILL INCREASE TOWARDS THE 00Z TIME FRAME THIS EVENING...WHICH WOULD ACT TO HELP FOR ORGANIZATION AND INCREASE IN THREAT FOR LINEAR STRUCTURES/STRONG DAMAGING WINDS. SO HAVE TRENDED MORE PESSIMISTIC...WITH THINKING THAT THIS LINE AND STRONG DAMAGING WINDS COULD MOVE ACROSS NORTHERN ILLINOIS THIS EVENING. HAVE ALSO TRENDED MORE TOWARDS THE HRRR...WITH SYSTEM TIMING THINKING THAT IT SHOULD BE KNOCKING ON THE WESTERN CWA DOORSTEPS BY 00-01Z AND THEN CONTINUE EAST TOWARDS NORTHEAST ILLINOIS THROUGH THE SEVERAL HOURS THERE AFTER. BEYOND THAT TIME FRAME...CONFIDENCE LOWERS WITH REGARDS TO THE STRENGTH OF THIS SYSTEM. NONETHELESS...HEAVY RAINFALL AND FLASH FLOODING COULD BECOME ISSUES OVERNIGHT TONIGHT ESPECIALLY AS PWATS ARE AT OR JUST ABOVE 1.7 INCHES AND 850MB DEW POINTS REMAIN RATHER HIGH. THUNDERSTORM COMPLEX IS THEN EXPECTED TO SHIFT EAST OF THE CWA BY EARLY FRIDAY MORNING...WITH A DRYING TREND EXPECTED DURING THAT TIME FRAME. THIS SHOULD NOT LAST TOO LONG WITH DRY CONDITIONS ONLY EXPECTED THROUGH MID DAY AS ATTENTION QUICKLY SHIFTS BACK WEST WITH THE APPROACH OF ANOTHER STRONG MID LEVEL WAVE EJECTING OUT OF THE CENTRAL PLAINS. YET AGAIN...A SEVERE THREAT WILL BE IN PLACE ON FRIDAY WITH GROWING CONCERNS OF MORE POTENTIAL FLOODING FROM THIS POINT ON...INTO FRIDAY NIGHT AND SATURDAY. THE SEVERE THREAT WILL LIKELY AFFECT THE ENTIRE CWA ON FRIDAY AND WITH CLEARING ANTICIPATED FRIDAY MORNING...INSTABILITY IS EXPECTED TO RAPIDLY INCREASE BY LATE MORNING WITH MODERATE TO STRONG INSTABILITY LIKELY IN PLACE ACROSS THE CWA. STRONG DEEP LAYER SHEAR IN UPWARDS OF 50-60KT WILL EASILY SUPPORT WIDESPREAD ORGANIZED DEVELOPMENT AS SOON AS EARLY AFTERNOON ON FRIDAY. STRONG DAMAGING WINDS AND HAIL ARE THE MAIN THREAT...BUT WITH SREF GUIDANCE INDICATING ELEMENTS CORRESPONDING TO SUPERCELLULAR STRUCTURES OR ROTATING THUNDERSTORMS COULD COME TOGETHER ACROSS THE CWA. WILL NEED TO CONTINUE TO MONITOR THIS TIME FRAME AS WELL...AS WIDESPREAD SEVERE IS APPEARING LIKELY ONCE AGAIN. GOING INTO FRIDAY NIGHT...HEAVY RAINFALL APPEARS LIKELY WITH SEVERAL STRONG WAVES PROPAGATING NORTHEAST ACROSS THE CWA PROVIDING CONTINUED DEVELOPMENT AS WELL AS A STRONG LLJ ORIENTED TOWARDS NORTHEAST ILLINOIS...PUMPING HIGH THETAE AIR INTO THE REGION. RODRIGUEZ EXTENDED PERIOD...SUNDAY THROUGH THURSDAY... BY DAYBREAK SUNDAY THE UPPER RIDGE IS TO HAVE PROGRESSED EASTWARD TO OVER THE UPPER MIDWEST AND MID MS VALLEY WITH A SURFACE TROUGH/SECONDARY COLD FRONT JUST TO THE NORTHWEST AND NORTH OF THE LOCAL FORECAST AREA. THIS TROUGH/FRONT IS PROGGED TO MOVE ACROSS ALL OF THE FA DURING THE SUNDAY MORNING AS THE UPPER TROUGH CONTINUES ON TO OVER THE UPPER GREAT LAKES AND LOWER OH VALLEY BY EVENING. UNTIL THE TROUGH AXIS MOVES A BIT FURTHER EAST OF THE IMMEDIATE AREA THERE WILL BE A LINGERING CHANCE OF SHOWERS DURING SUNDAY MORNING. THE SECONDARY COLD FRONT WILL REINFORCE THE COLD AIR ADVECTION THAT WILL HAVE STARTED TO OCCUR LATE SATURDAY AND SATURDAY NIGHT WITH THE INITIAL COLD FRONT. BETWEEN THE PAIR OF FRONT 850HPA TEMPERATURES ARE PROGGED TO FALL AROUND 10 DEGREES C FROM 18Z SATURDAY TO 00Z MONDAY......DOWN TO AROUND +4 OR +5C. WITH COOL HIGH PRESSURE BUILDING OVER THE AREA TEMPERATURES WILL BE COOL SUNDAY AND MONDAY WITH HIGHS ONLY IN THE 60S...WITH LAKESIDE MAX TEMPERATURES LIKELY TO ONLY BE IN THE 55-60F RANGE AS A LONG FETCH DOWN LAKE MICHIGAN BRINGS AIR ADDITIONALLY COOLED BY THE STILL CHILLY LAKE ASHORE SUNDAY. WHILE THE SURFACE RIDGE AXIS WILL BE MOVING OVER WI AND WESTERN IL DURING MONDAY ALLOWING WINDS TO SLACKEN...A WEAK NE SYNOPTIC FLOW WILL STILL BE IN PLACE AIDED BY A LAKE BREEZE. THE FURTHER EASTWARD PROGRESS OF THE UPPER TROUGH IS TO BE SLOW AS A CLOSED LOW TO FORM OVER SOUTHERN HUDSON BAY/NORTHERN ONTARIO IS PROGGED TO BE DROP SOUTH...THEN SOUTHEAST AND EAST OVER ONTARIO SATURDAY NIGHT THROUGH MONDAY NIGHT. AS THE UPPER TROUGH/LOW MOVES FURTHER EAST A WEAK UPPER RIDGE WILL MOVE OVER THE REGION TUESDAY AS ANOTHER UPPER LOW MOVES EAST OVER THE FAR SOUTHERN CANADIAN PRAIRIE/FAR NORTHERN PLAINS. THIS WILL ALLOW A BIT OF MODERATION IN TEMPERATURES TUESDAY AND WEDNESDAY AS EAST-SOUTHEAST WINDS BECOMES SOUTHEASTERLY AND INCREASING THOUGH THIS LOW LEVEL FLOW WILL KEEP THE IL SHORE...ESPECIALLY THE FAR NORTHERN PART....STILL CHILLY. INLAND AREAS SHOULD PEAK IN THE UPPER 60S AND LOWER 70S TUESDAY... AND A COUPLE DEGREES WARMER WEDNESDAY. WITH CONTINUED WARM AIR ADVECTION AHEAD OF THE APPROACHING UPPER LOW/TROUGH THE WARMING TREND WILL CONTINUE THURSDAY WITH MOST LOCATIONS REACHING THE MID AND UPPER 70S THOUGH THERE WILL STILL BE AN EASTERLY COMPONENT TO THE LOW LEVEL FLOW TO KEEP THE IL SHORELINE IN THE 60S. TRS && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * SHRA CONTINUING THROUGH 08Z-10Z WITH ONLY A SMALL CHANCE OF THUNDER IN THAT TIME. * SOME SHIFTING IN THE WINDS FROM SE TO SW THROUGH 12Z OR SO BUT GUSTINESS SHOULD ONLY BE SPORADIC. * MVFR FOG POSSIBLE AROUND DAYBREAK. * SOUTHERLY WINDS GUSTING TO AROUND 25 KT DURING THE DAY TODAY. * STORM CHANCES...INCLUDING STRONG POTENTIAL...RETURNING FRI AFTERNOON AND EVE. //DISCUSSION...UPDATED 06Z... PERIODS OF MAINLY SHOWERS...WITH SOME STORMS /ESPECIALLY SOUTH AND EAST TRACON AREAS/...WITH CONTINUE THROUGH 09Z-10Z. THERE IS EXPECTED TO BE A LULL IN PRECIP COVERAGE DURING THE MORNING RUSH BUT THERE STILL MAY BE A FEW SCATTERED SHOWERS. THE RAINS HAVE FURTHER MADE THE LOW-LEVELS MOIST WHICH COULD HELP PATCHY FOG DEVELOPMENT NEAR DAWN. SOUTHERLY WINDS WILL INCREASE AFTER DAYBREAK AS MIXING ENSUES AND SOME STRONG GUSTS TO AROUND 25 KT ARE EXPECTED AGAIN. AS FOR THUNDER CHANCES THIS AFTERNOON AND EVE...IT IS CHALLENGING AND QUITE A BIT IS LIKELY TO DEPEND ON HOW THUNDER ACTIVITY IN EASTERN KS/MO PLAYS OUT EARLY THIS MORNING. IF THIS WORKS INTO IL BY LATE MORNING/EARLY AFTERNOON IT MAY STIFLE SOME OF THE EXPLOSIVE CONVECTIVE DEVELOPMENT THAT COULD OCCUR WITH AS MUCH INSTABILITY AS WILL BE PRESENT. IT ALSO COULD KEEP MUCH OF THE STORM ACTIVITY SOUTH OF THE CHICAGOLAND TERMINALS. THAT SAID...THE CERTAINTY ON HOW THIS EARLY MORNING CONVECTION TO OUR WEST PLAYS OUT IS LOW. WHILE THE SETUP FOR LATER TODAY INTO THIS EVE COULD PRESENT SEVERAL HOURS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN SHOWERS WITH MEDIUM CONFIDENCE IN NO THUNDER OR IFR CONDITIONS IN RAIN. * HIGH CONFIDENCE IN SOUTHERLY WINDS DURING THE DAY WITH MEDIUM CONFIDENCE IN MAGNITUDE OF THE GUSTS. * LOW CONFIDENCE ON TIMING AND DURATION OF AFTERNOON/EVE THUNDERSTORMS. //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 06Z... * SATURDAY...TSRA LIKELY DURING THE DAY WITH A CHANCE OF SHRA DURING THE NIGHT. MVFR CIGS/VIS POSSIBLE. * SUNDAY...CHANCE OF SHRA EARLY...OTRW...VFR. * MONDAY THROUGH EARLY TUESDAY...VFR. WX NIL. * LATE TUESDAY THROUGH WEDNESDAY...CHANCE TSRA/SHRA. MTF && .MARINE... 1259 PM CDT THE SHORT TERM OF THE MARINE FORECAST HAS A SMALL CRAFT ADVISORY FOR STRONG WINDS ACROSS THE ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS. ACROSS THE OPEN WATERS OF THE LAKE...MAINLY THE NORTHERN THIRD OF THE LAKE...AREAS OF DENSE FOG CONTINUE. VERY WARM/MOIST AIR CONTINUES TO SLIDE NORTH ACROSS THE LAKE...AND WITH THE MUCH COOLER LAKE SURFACE WATER...HAS RESULTED IN AREAS OF DENSE FOG PERSISTING. IT DOES APPEAR BASED ON LATEST VISIBLE IMAGERY THAT THE FOG HAS REMAINED FOCUSED ACROSS THE NORTHERN THIRD OF THE LAKE. OBS HAVE CONTINUED TO SHOW INCREASING GUSTS...WITH SPEEDS GENERALLY AROUND 20-25KT ACROSS THE SOUTHERN HALF OF THE LAKE. FURTHER NORTH IT APPEARS THE WINDS ARE SLIGHTLY LESS...WITH SPEEDS GENERALLY IN THE 15-25KT. THE TROUGH OF LOW PRESSURE REMAINS CENTERED ACROSS THE CENTRAL PLAINS...WITH A WEAK LOW PRESSURE LIFTING NORTH INTO THE NORTHERN PLAINS. AN ASSOCIATED WARM FRONT EXTENDS EAST THROUGH THE UPPER GREAT LAKES REGION. WITH THE POSITION OF THE LOW PRESSURE AND THE PERSISTING RIDGE OF HIGH PRESSURE ACROSS THE SOUTHEASTERN UNITED STATES...THE WIND FLOW WILL REMAIN SOUTHERLY ACROSS THE LAKE. AT TIMES THROUGH EARLY THIS EVENING GUSTS MAY APPROACH 30 KT...MAINLY FOR THE SOUTHERN PORTIONS OF THE LAKE INCLUDING THE NEARSHORE WATERS. AS A RESULT WILL MAINTAIN THE CURRENT SMALL CRAFT ADVISORY THAT IS IN EFFECT. THE TROUGH OF LOW PRESSURE POSITIONED OVER THE CENTRAL PLAINS WILL SLOWLY PUSH EAST...WITH A LOW PRESSURE APPROACHING THE WESTERN GREAT LAKES SAT MIDDAY. THE RECENT FORECAST TRENDS HAVE BEEN TO SLOW THE ARRIVAL OF THIS SYSTEM...THUS IT IS POSSIBLE THAT THE MAIN LOW PRESSURE MAY NOT ARRIVE UNTIL CLOSER TO SAT NIGHT. THEN AN ASSOCIATED COLD FRONT WILL WILL PUSH EAST ACROSS THE LAKE OVERNIGHT SAT INTO SUN. WINDS AT THAT POINT WILL TURN WESTERLY THEN NORTHERLY WITH MUCH COOLER AIR FLOWING OVER THE LAKE. BEACHLER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022- ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 7 PM SATURDAY. IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 7 PM SATURDAY. LM...DENSE FOG ADVISORY...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 7 AM FRIDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
705 PM EDT FRI MAY 31 2013 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 353 PM EDT FRI MAY 31 2013 SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WILL IMPACT CENTRAL INDIANA AS A SLOW MOVING COLD FRONT APPROACHES. THE FRONT WILL MOVE THROUGH THE REGION SATURDAY NIGHT WITH COOLER AND MUCH DRIER AIR SPREADING IN WITH HIGH PRESSURE FOR THE FIRST HALF OF THE WORK WEEK. CHANCES FOR THUNDERSTORMS WILL RETURN THURSDAY AND FRIDAY AS A COLD FRONT MOVES INTO THE REGION. && .NEAR TERM /TONIGHT/... ISSUED AT 353 PM EDT FRI MAY 31 2013 BULK OF THE RAINFALL FROM EARLIER COMPLEX HAS SHIFTED EAST AND INTENSIFIED AS IT HAS MOVED INTO A MORE UNSTABLE AIRMASS ACROSS NORTHEAST KENTUCKY AND WESTERN OHIO. MUCH OF THE FORECAST AREA REMAINS SHROUDED IN A RELATIVELY THICK VEIL OF CLOUD COVER WITH SOME BREAKS HAVING DEVELOPED OVER THE WABASH VALLEY. THIS HAS SIGNIFICANTLY IMPEDED TEMP RISES SO FAR...ALTHOUGH MUCH OF THE FORECAST AREA HAS MADE IT INTO THE 70S AS OF 19Z. DIFFICULT FORECAST FOR TONIGHT WITH CONCERNS GROWING FOR HEAVY RAIN AND FLOODING AND POTENTIALLY A DECREASING THREAT FOR SEVERE WEATHER. LITTLE IN THE WAY OF INSTABILITY ACROSS THE FORECAST AREA AS THE CLOUDS AND RAIN HAVE REALLY WORKED OVER THE AIRMASS. AS MENTIONED...DO EXPECT SOME THINNING OF THE CANOPY OVER THE NEXT FEW HOURS WHICH SHOULD ALLOW FOR SOME DESTABILIZATION TO TAKE PLACE. HOWEVER...PRESENCE OF WEAKENING MCV OVER CENTRAL ILLINOIS IS LIKELY TO MAINTAIN A FAIR AMOUNT OF CLOUD COVER RIGHT INTO THE EVENING AND SHOULD KEEP CONVECTION SCATTERED THROUGH 00Z. EXPECT ROBUST CONVECTIVE DEVELOPMENT OVER THE OZARKS BACK INTO OKLAHOMA AS THE AFTERNOON WEARS ON...WITH ADDITIONAL DEVELOPMENT LIKELY EXPANDING NORTHEAST INTO THE MISSISSIPPI VALLEY AND INTO ILLINOIS AS INCREASED BL SHEAR AND FORCING ALOFT COURTESY OF AN INTENSIFYING UPPER JET. NOCTURNAL LOW LEVEL JET WILL ONCE AGAIN DEVELOP AND NOSE INTO THE REGION AFTER NIGHTFALL AND COMBINED WITH THE BETTER UPPER LEVEL FORCING APPROACHING FROM THE WEST AND WHATEVER INSTABILITY CAN BE GLEANED OVER THE NEXT SEVERAL HOURS...ANTICIPATE CONVECTION TO THE WEST TO COALESCE INTO AN MCS AND DROP SOUTHEAST INTO THE FORECAST AREA OVERNIGHT. LACK OF MORE SUBSTANTIAL INSTABILITY HAS RAISED DOUBTS AS TO WHETHER STORMS WILL BE SEVERE AS THEY ENTER THE FORECAST AREA. FEELING AT THIS POINT IS THAT STORMS WILL BE STRONG WITH POTENTIALLY AN ISOLATED RISK FOR DAMAGING WINDS. OTHERWISE...THE PRIMARY CONCERN WILL BE THE HEAVY RAIN. HEAVY RAIN AND FLOODING IS BECOMING A GREATER CONCERN...ESPECIALLY ACROSS THE WABASH VALLEY WHICH EXPERIENCED 1 TO 2 INCHES OF RAIN LAST NIGHT AND EARLY THIS MORNING. PRECIPITABLE WATER VALUES IN EXCESS OF 1.75 INCHES ARE ANTICIPATED OVERNIGHT WITH A DEEP SATURATED COLUMN EXTENDING UP TO NEAR 650MB. IN ADDITION...BROAD SOUTHWEST FLOW ALOFT AND POTENTIAL FOR AN AXIS OF DEEP CONVERGENCE UP TO ABOUT 700MB ALL SUPPORT POTENTIAL FOR TORRENTIAL RAINFALL AND EFFICIENT RATES LATE TONIGHT. COULD SEE AMOUNTS IN EXCESS OF 1-2 INCHES OVER FAR WESTERN FORECAST AREA. WILL BE INTRODUCING A FLASH FLOOD WATCH FOR THE WABASH VALLEY THROUGH 12Z SUNDAY BECAUSE OF THESE CONCERNS. WILL RAISE POPS TO LIKELY OVER THE EAST AND CATEGORICAL OVER THE WEST LATE TONIGHT. TEMPS...MOS GUIDANCE LOOKS REASONABLE AS LOW TEMPS WILL ONLY FALL INTO THE UPPER 60S TO NEAR 70 WITH SATURATED LOWER LEVELS. && .SHORT TERM /SATURDAY THROUGH MONDAY/... ISSUED AT 353 PM EDT FRI MAY 31 2013 FORECAST CHALLENGES REMAIN ON HEAVY RAIN AND SEVERE WEATHER POTENTIAL THROUGH SATURDAY NIGHT AS THE COLD FRONT TRACKS SLOWLY THROUGH THE REGION. POTENTIAL FOR A SCENARIO SIMILAR TO THIS MORNING TO PLAY OUT SATURDAY MORNING AS REGION MAY RESIDE UNDERNEATH A THICK CLOUD CANOPY WITHIN A STABLE ENVIRONMENT IN WAKE OF OVERNIGHT CONVECTION. THAT PRESENTS CHALLENGES ONCE AGAIN AS TO WHETHER ANY SUBSTANTIAL HEATING CAN TAKE PLACE THROUGHOUT THE DAY AND ULTIMATELY HOW UNSTABLE THE AIRMASS CAN GET BY AFTERNOON. THE UPPER LEVEL DYNAMICS ARE ARGUABLY BETTER WITH CENTRAL INDIANA REMAINING IN THE RIGHT REAR QUAD OF THE 100KT UPPER JET WITH UPPER DIFFLUENCE AHEAD OF THE WAVE ALOFT ENHANCING CONVECTIVE DEVELOPMENT. ADDITIONALLY...LOW LEVEL JET WILL PERSIST ACROSS THE REGION ALL DAY WITH PRECIP WATER VALUES REMAINING ABOVE 1.50-1.75 IN. THE QUESTION MARK AGAIN IS WHETHER INSTABILITY WILL BE HAMPERED BASED ON CLOUD COVER AND ADDITIONAL CONVECTIVE DEVELOPMENT AS THE DAY PROGRESSES. WHILE ISOLATED DAMAGING WINDS FROM STORMS CANNOT BE RULED OUT...CONFIDENCE REMAINS LOW IN A LARGER SCALE SEVERE WEATHER EVENT SATURDAY AFTERNOON AND EVENING BASED ON FACTORS MENTIONED ABOVE. AT THIS POINT...CONCERN IS ONCE AGAIN GREATER TOWARDS HEAVY RAINFALL WITH DEEP MOISTURE REMAINING AND THE PRESENCE OF THE LOW LEVEL JET AND SUBSEQUENT CONVERGENCE THROUGH THE BOUNDARY LAYER. COULD EASILY SEE REPEATED ROUNDS OF STORMS THROUGHOUT THE DAY OR POSSIBLY ANOTHER MCS LATER IN THE AFTERNOON AND EVENING AS THE UPPER LEVEL SUPPORT MOVES IN FROM THE WEST. THE POTENTIAL FOR ANOTHER 1-2 INCHES OF RAINFALL IS POSSIBLE INTO SATURDAY EVENING. DEPENDING ON HOW THE CONVECTIVE PATTERN EVOLVES TONIGHT AND INTO SATURDAY...THE FLASH FLOOD WATCH MAY NEED TO BE EXPANDED FURTHER EAST ACROSS THE FORECAST AREA. MODEL GUIDANCE CONSISTENT IN BRINGING THE UPPER TROUGH AXIS AND COLD FRONT ACROSS THE REGION LATE SATURDAY NIGHT WITH WIDESPREAD RAINFALL SHIFTING EAST. HAVE HELD ONTO SLIGHT CHANCE POPS SUNDAY AS A WEAK SHORTWAVE ALOFT MOVES ACROSS THE OHIO VALLEY AND INTERACTS WITH THE COLD POOL IN WAKE OF THE FRONTAL PASSAGE. EXPECT JUST ISOLATED SHOWERS AS MODEL SOUNDINGS SHOW LIMITED INSTABILITY. REMAINDER OF THE SHORT TERM WILL BE QUIET AS A LARGE AREA OF HIGH PRESSURE BUILDS IN WITH COOLER AND MUCH DRIER AIR. TEMPS...WITH THE EXPECTATION OF CLOUD COVER AND WIDESPREAD PRECIP COVERAGE ON SATURDAY...FELT MAVMOS GUIDANCE TOO WARM WITH TEMPS IN THE MID 80S. UNDERCUT BY SEVERAL DEGREES AND KEEPING MUCH OF THE FORECAST AREA IN THE 70S. COOLER AIR EXPANDS INTO THE REGION SUNDAY AND MONDAY WITH TEMPS FALLING BACK INTO THE UPPER 60S/LOWER 70S BY MONDAY. MOS LOOKED REASONABLE FOR OVERNIGHT LOWS. COULD SEE SOME UPPER 40S IN RURAL LOCALES NORTH OF INDY METRO MONDAY MORNING. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ISSUED AT 256 PM EDT FRI MAY 31 2013 FAIRLY QUIET START TO THE LONG TERM PERIOD WITH BROAD SURFACE HIGH PRESSURE OVER THE AREA. AN UPPER LEVEL SYSTEM WILL PUSH ACROSS THE NORTHERN PLAINS...AND MAY BRING SOME THUNDERSTORMS TO THE AREA BEGINNING AS EARLY AS WEDNESDAY NIGHT...WITH CHANCES INCREASING TOWARD THE END OF THE WEEK. ALLBLEND HANDLED THIS WELL AND REQUIRED FEW TWEAKS. INITIALIZED TEMPERATURES WERE FAIRLY CLOSE...AGAIN WITH ONLY A FEW MINOR TWEAKS REQUIRED. SHOULD SEE A SLIGHT WARMING TREND THROUGH THE WEEK...WITH TEMPERATURES IN THE 80S MAKING A RETURN TO THE AREA LATE IN THE WEEK. && .AVIATION /DISCUSSION FOR 010000Z TAF ISSUANCE/... ISSUED AT 703 PM EDT FRI MAY 31 2013 SOME MVFR CLOUDS OVER THE SITES CURRENTLY BUT THESE SHOULD LESSEN WITH SUNSET AND VFR SHOULD BE THE RULE FOR A COUPLE OF HOURS. A LINE OF THUNDERSTORMS CURRENTLY OVER WESTERN ILLINOIS WILL MOVE INTO THE AREA STARTING AROUND 3-4Z OR SO AT KLAF AND THEN OVERSPREAD THE OTHER SITES WITHIN A FEW HOURS. HRRR SHOWS THESE STORMS HANGING AROUND THE SITES FOR SEVERAL HOURS AND NOT REALLY MOVING OFF TO THE EAST UNTIL AFTER 12Z SATURDAY. WITH GRIDDED FORECAST ALSO SHOWING LIKELY OR GREAT THUNDER CHANCES WILL GO WITH PREVAILING THUNDER FROM ARRIVAL THROUGH MORNING. AFTER THAT WILL INCLUDE A PROB30 WITH GRIDS STILL SHOWING LIKELY OR GREATER THUNDER CHANCES BUT THE EXPECTATION THAT THERE WILL BE SOME SORT OF LULL IN THE MORNING BEFORE THUNDERSTORMS FIRE UP AGAIN IN THE AFTERNOON. THUS WITH VERY HIGH POPS AND THOUGHT THAT THUNDER WILL REFIRE IN THE AFTERNOON BROUGHT PREVAILING THUNDER BACK IN AFTER 18Z. FAIRLY UNCERTAIN ABOUT WIND GUSTS THROUGH THE OVERNIGHT. THINK THEY WILL NOT BE CONSTANT BUT SHOULD PICK BACK UP IN/AROUND THUNDERSTORMS SO WILL ALLOW THESE TO BE PREVAILING FOR MUCH OF THE NIGHT AS WELL. MAY DROP OFF IN THE MORNING BEFORE PICKING BACK UP WITH GUSTS OF 20-25 KTS OUT OF THE SOUTHWEST AGAIN IN THE AFTERNOON. && .IND WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR INZ028-029-035-036- 043>045-051>053-060-061-067>069. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM....NIELD AVIATION...CP VISIT US AT HTTP://WWW.WEATHER.GOV/IND FOLLOW US ON TWITTER AND YOUTUBE AT: WWW.TWITTER.COM/NWSINDIANAPOLIS WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
222 AM EDT FRI MAY 31 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 300 PM EDT THU MAY 30 2013 THE MAIN FOCUS THIS PERIOD IS ON CONVECTIVE POTENTIAL/EVOLUTION. SYNOPTICALLY...A CLOSED LOW WILL MEANDER SLOWLY EAST ACROSS THE NORTHERN PLAINS WITH DEEP/MOIST CYCLONICALLY CURVED SOUTHWEST FLOW IN PLACE FROM THE SOUTHERN PLAINS NORTHEAST INTO THE GREAT LAKES REGION. AT THE SURFACE THE PRIMARY SFC FRONT FRONT WILL BE DRAPED FROM THE UPPER MIDWEST SOUTHWEST INTO THE SOUTHERN PLAINS WITH A MOIST/HUMID/UNSTABLE AIRMASS OUT AHEAD OF THIS. THE REMAINDER OF THE AFTERNOON INTO EARLY THIS EVENING... 19Z REGIONAL RADAR MOSAIC SHOWING SCATTERED CONVECTION FIRING ACROSS MUCH OF ILLINOIS IN A ZONE OF WEAK MOISTURE CONVERGENCE ON THE EASTERN FLANK OF A CONVECTIVELY ENHANCED/INDUCED SHORTWAVE LIFTING INTO WEST-CENTRAL ILLINOIS...WITH ISOLATED CONVECTION STARTING TO POP ACROSS THE LOCAL AREA. LATEST RAP ANALYSIS SHOWS 1500-2000 J/KG OF MLCAPE ACROSS THE AREA WITH LITTLE/NO CIN. EXPECT ISOLATED TO SCATTERED CONVECTION TO MAINLY IMPACT AREAS ALONG AND WEST OF INTERSTATE 69 INTO THE EARLY EVENING AS WEAK FORCING AND CONTINUED LOW/MID LEVEL THETA-E ADVECTION ADVECTS OVER THIS AREA. MARGINAL 20-25 KNOTS OF DEEP LAYER EFFECTIVE SHEAR A DEFINITE LIMITING FACTOR FOR ORGANIZATION AND ISOLATED SEVERE STORMS...ALTHOUGH CANNOT RULE OUT AN ISOLATED DAMAGING WIND/HAIL THREAT IF ANY MULTICELL CLUSTERS/SMALL LINE SEGMENTS TAKE SHAPE. LARGE SCALE UPPER SUPPORT WILL INCREASE TONIGHT INTO FRIDAY MORNING AS A MORE PRONOUNCED MID LEVEL SHORTWAVE TROUGH NOW EJECTING INTO THE CENTRAL PLAINS ON THE NOSE OF AN UPPER JET TRANSLATES NORTHEAST INTO THE WESTERN/NORTHERN GREAT LAKES. THIS SUPPORTS THE IDEA OF LATEST HI-RES GUIDANCE IN MAINTAINING A WEAKENING MESOSCALE CONVECTIVE SYSTEM (ACROSS CENTRAL IOWA INTO WESTERN MISSOURI AS OF THIS WRITING) EAST INTO AT LEAST OUR WESTERN ZONES AFTER 05/06Z ISH. MEAGER MID LEVEL LAPSE RATES COUPLED WITH DIURNAL COOLING SHOULD ALLOW WHAT MIGHT BE A LINE OF SEVERE CONVECTION INTO ILLINOIS THIS EVENING TO WEAKEN (FALL APART?) AS IT ATTEMPTS TO MAKE INTO THE LOCAL AREA FROM WEST TO EAST OVERNIGHT...WITH SHOWERS/ISO THUNDER POSSIBLY LINGERING INTO FRIDAY MORNING ALONG THE MCS/MCV RESIDUAL OUTFLOW BOUNDARY. BUMPED UP POPS A BIT AFTER MIDNIGHT....HIGHEST WEST. SUBSIDENCE/AVA BEHIND THE MID LEVEL TROUGH AXIS LATER FRIDAY MORNING INTO THE EARLY/MID AFTERNOON HOURS WITH ATMOSPHERE POSSIBLY WORKED OVER FROM MORNING CLOUDS/SHOWERS SHOULD RESULT IN A LULL IN PCPN ACROSS THE AREA DURING THIS TIME. ALTHOUGH RETAINED LOW 20-30 PERCENT POPS BTW 15-21Z AS RENEWED CONVECTION COULD FORM ALONG THE RESIDUAL OUTFLOW BOUNDARY BY EARLY/MID AFTERNOON...BEST CHANCES ACROSS OUR SOUTHEASTERN ZONES. CHANCES FOR ADDITIONAL CONVECTION...POTENTIALLY SEVERE...BY LATE AFTERNOON AND EVENING ARE DISCUSSED IN THE LONG TERM SECTION. && .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 300 PM EDT THU MAY 30 2013 POTENT SW AND ATTENDANT CLOSED LOW OVR SD IS XCPD TO OPEN FRI NIGHT AND KICK EWD ACRS THE LAKES IN RESPONSE OF ARRIVAL OF UPSTREAM KICKER INTO THE PACNW. AT THE SFC...PRONOUNCED SFC WAVE OVR SRN MN SAT MORNING WILL EJECT EWD TO LK HURON BY SUN MORNING AS ASSOCD TRAILING CDFNT SURGES EWD. BEST LL MSTR FLUX/LL THETA-E RIDGING XCPD FRI EVENING W/AGAIN A CONDITIONAL SVR THREAT PENDING SHRT TERM CONV EVOLUTION/MAINTENANCE INTO THE WRN LAKES FRI AFTN. OTRWS STG SFC CDFNT TO CROSS CWA SAT AFTN/EVE W/STG FORCING FOR ASCENT WITHIN CONTD SIG LL MSTR PLUME AND LIKELY MOST FVRBL WINDOW FOR SIG RAINFALL. STG CAA FOLLOWS ON SUN W/RAPID NEWD ADVTN OF MID LVL DRYSLOT UNDERNEATH MID LVL TROUGH PIVOTING THROUGH MI. GIVEN GENERAL 12Z CONSENSUS SOLUTION WILL DROP LOW CHC POPS MOST AREAS SANS FAR SE. DRY AND SEASONABLE WX XPCD THROUGH UNTIL THE END OF THE PD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 220 AM EDT FRI MAY 31 2013 MARGINAL INSTABILITY DOWNSTREAM OF ONGOING TSRA AT KSBN...WITH ONLY TRAILING STRATIFORM SHRA EXPECTED BEYOND 07 UTC. RAMPED 50KT SWRLY FLOW AT 8H SHOULD AID IN MAINTENANCE/SLOW DECAY OF SLIGHTLY MORE ORGANIZED CONVECTION ACROSS WEST CENTRAL INDIANA...ASSOCIATED WITH HIGHER POCKETS OF EFFECTIVE DEEP LAYER SHEAR ON ORDER OF 35KTS...SUCH THAT INCLUSION OF LOW/MEDIUM CONFIDENCE FOR TSRA INTO KFWA IN 08-10 UTC TIMEFRAME...THOUGH BESIDES CONVECTIVELY INDUCED HAZARDS ANTICIPATE ONLY A BRIEF HIGH END MVFR VSBY REDUCTION IN CELL CENTROIDS. GREAT UNCERTAINTY AS A MULTITUDE OF LESS THAN STELLAR MODEL INDICATIONS/CONVECTIVE TRENDS LATER TODAY BELIES MOST PROBABLE OUTCOME. IMMEDIATE UPSTREAM DESTABILIZATION ACROSS MID MISSISSIPPI VALLEY ALONG WITH MARKEDLY INCREASED DEEP LAYER SHEAR TO SUPPORT STORM DEVELOPMENT BY LATE AFTERNOON/EVENING ACROSS IA/MO/IL AND INTO NRN IN BY LATE EVENING THROUGH END OF FORECAST PERIOD WITH PSBL LINEAR ORGANIZATION SUPPORTING STRONG WIND GUST RISK. TIMING TO LIKELY CHANGE/EVOLVE IN SUBSEQUENT ISSUANCES AS NUANCES FROM EFFECTS OF ONGOING CONVECTION BETTER DETERMINED. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...STEINWEDEL LONG TERM...T AVIATION...MURPHY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1243 PM CDT FRI MAY 31 2013 .SHORT TERM.../TODAY /... ISSUED AT 323 AM CDT FRI MAY 31 2013 THUNDERSTORMS HAVE DEVELOPED IN NORTHERN MISSOURI ALONG A ZONE OF WARM AIR ADVECTION AND A LOW LEVEL JET. JUST NORTH OF THAT AREA BUT STILL IN MO SOME WEAKER STORMS HAVE DEVELOPED AND ARE DISSIPATING. THE STORMS HAVE AN EAST/NORTHEASTERLY TRACK AND WILL EVENTUALLY CLIP FAR SOUTHERN IOWA. THE WEAKENING STORMS JUST ACROSS OUR BORDER WILL LIKELY ONLY PRODUCE SOME SHOWERS ACROSS THE FAR SOUTH IN THE NEXT FEW HOURS. A VORT MAX AND SHORT WAVE WILL PIVOT AROUND THE UPPER LOW OVER THE EASTERN DAKOTAS AND THIS WILL SHIFT THE STORMS THAT ARE A LITTLE FURTHER SOUTH IN NORTHERN MO RIGHT INTO SOUTHERN/SOUTHEAST IOWA BY MID TO LATE MORNING THEN INTO EASTERN IOWA BY EARLY AFTERNOON. BY MID TO LATE AFTERNOON A STRONGER SHORT WAVE WILL PUSH INTO WESTERN IOWA WHICH WILL BRING MORE THUNDERSTORMS TO THAT AREA AND THIS WILL SHIFT EAST FROM 21Z INTO THE EVENING HOURS. THERE WILL BE A TIME IN THE AFTERNOON WHERE SHOWERS AND STORMS WILL STILL BE OVER EASTERN IOWA AND ADDITIONAL STORMS DEVELOPING OVER THE WEST WITH CENTRAL IOWA DRY. LAPSE RATES OVER SOUTHERN IOWA AND ABOUT THE SOUTHEAST THIRD OF THE STATE ARE PRETTY STEEP THIS AFTERNOON AND THERE IS MORE THAN SUFFICIENT SHEAR FOR A FEW SEVERE STORMS. IN ADDITION...HEAVY RAINFALL IS LIKELY WITH THE STORMS AS WELL...MAINLY OVER THE FAR EAST AND SOUTHEAST. YESTERDAY THE HI RES NMM EAST REALLY HAD THE PRECIP AREAS PEGGED AND ALSO HAD DECENT TIMING OF THE PRECIP. I STILL LIKE WHAT THIS MODEL DOES WITH THE PRECIP TODAY HOWEVER IT IS NOT PICKING UP THE MO CONVECTION VERY WELL AT THIS TIME. IT IS ABOUT 3 HOURS LATER WITH THAT SO I BLENDED NMM POPS WITH THE HRRR AND NAM12. AS FOR TEMPS...THERE SHOULD BE SLIGHTLY WARMER AIR OVER THE SOUTH AND SOUTHEAST TODAY SO I NUDGED HIGHS UP IN THESE AREAS. THE NORTH SHOULD SEE TEMPS A FEW DEGREES WARMER AS WELL. .LONG TERM.../TONIGHT THROUGH WEDNESDAY/... ISSUED AT 323 AM CDT FRI MAY 31 2013 FEWER CONCERNS FOR THE NEXT SEVERAL DAYS AS UPPER TROUGH BEGINS TO SWING EAST. ALREADY THE MAIN H850 MOISTURE CHANNEL HAS SHIFTED EAST OF THE AREA WITH THE LINE OF STRONGER THUNDERSTORMS THAT EXITED THE EASTERN PORTION OF THE FORECAST AREA EARLY THIS EVENING. HOWEVER THERE WILL STILL BE SOME RESIDUAL CONVECTION FAR SOUTHEAST EARLY IN THE PERIOD TONIGHT...ENDING QUICKLY AND MOVING EAST BY 06Z. MEANWHILE...THE MAIN FEATURE YET LATE TONIGHT AND EARLY SATURDAY WILL BE THE OLD H500 LOW WHICH IS LIKELY TO SPIN UP SOME SHOWERS AND ISOLATED THUNDER AS IT MOVES ACROSS THE REGION TOMORROW AS THE COLD POOL UNDERNEATH THE UPPER LEVEL LOW DROPS SOUTHEAST INTO THE REGION. STEEP LAPSE RATES WILL BE IN THE AREA OF THE LOW ON SATURDAY AND OVER THE NORTH INTO MN AND WESTERN WI NON SUPERCELL TORNADO PARAMETER IS INCREASING. SOMETHING TO KEEP AN EYE ON THERE...AN ISOLATED FUNNEL CLOUD OR LANDSPOUT MAY BE POSSIBLE IF LAPSE RATES BECOME STEEP ENOUGH IN THE AFTERNOON HOURS. OTHERWISE...THE OLD LOW WILL PULL EAST SATURDAY NIGHT AND SUNDAY LEAVING THE REGION WITH COOLER AIR FOR THE FIRST PART OF JUNE. THIS WILL KEEP THE AREA IN THE 60S FOR HIGHS ON SUNDAY WITH MID 40S NORTH AND LOWER 50S SOUTH FOR LOWS ON MONDAY MORNING. AS THE HIGH MOVES EAST...HIGHS WILL RESPOND INTO THE LOWER 70S FOR MONDAY. MONDAY NIGHT WARM AIR ADVECTION AND MID LEVEL MOISTURE BEGIN TO INCREASE AGAIN...RESULTING IN LATE NIGHT/EARLY MORNING ELEVATED CONVECTION. TUESDAY LOOKS ACTIVE AS A STRONGER WAVE ROTATES NORTHEAST INTO THE STATE. THIS WILL RESULT IN MORE WIDESPREAD THUNDERSTORMS WITH RAINFALL AMOUNTS POSSIBLY APPROACHING ONE INCH IN SOME PLACES. THIS WILL CERTAINLY KEEP SOIL MOISTURE HIGH...AND ALSO RESULT IN RENEWED RIVER RISES. THE SYSTEM WILL GRADUALLY EXIT THE REGION BY THURSDAY. THE LARGER SCALE FLOW PATTERN REMAINS GENERALLY WESTERLY AT MID TO HIGH LEVELS. THIS PROMOTES LEE SIDE TROUGHING AND WITH A CONTINUED SUB TROPICAL HIGH ANCHORED OFF THE EAST COAST A WETTER THAN NORMAL PATTERN IS LIKELY TO CONTINUE OVER THE NEXT 7 TO 10 DAYS. ANOTHER INTERESTING WRINKLE IS A TROPICAL DISTURBANCE IN THE GULF OF MEXICO BY NEXT THUR/FRIDAY WHICH MAY EVENTUALLY BE PULLED NORTH TOWARD THE MID MISSISSIPPI RIVER VALLEY. HIGH TEMPERATURES OVER THE NEXT WEEK WILL LIKELY REMAIN IN THE 70S ON AVERAGE AND NOT BREAK OUT OF A 65 TO 75 RANGE BY TOO MUCH IF ANY. ANOTHER NOTE WITH OUR CURRENT WET WEATHER WILL BE CLOUD COVER. UNLESS WE HAVE A STRONG HIGH AND STRONG SUBSIDENCE...MOST LATE MORNINGS AND AFTERNOONS ON ANY SUNNY DAY WILL GO SCT TO BKN BY AFTERNOON. && .AVIATION...31/18Z ISSUED AT 1245 PM CDT FRI MAY 31 2013 A FEW SHOWERS AND THUNDERSTORMS STRETCHING ACROSS THE EASTERN CWA...SHOULD MAINLY IMPACT KALO AND KOTM THROUGH MID AFTERNOON. A FEW SCATTERED SHOWERS/ISOLATED THUNDERSTORMS MAY ALSO DEVELOP ACROSS THE NORTH TOWARD LATE AFTERNOON POSSIBLE IMPACTING KFOD AND KMCW. OTHERWISE MAINLY DRY CONDITIONS TONIGHT...WITH SOUTHERLY TO SOUTHWESTERLY WINDS BECOMING WESTERLY TO NORTHWESTERLY SATURDAY. MVFR TO LOW VFR CLOUDS EXPECTED TO IMPACT ENTIRE CWA SATURDAY AS MAIN UPPER LEVEL SYSTEM CURRENTLY ACROSS THE DAKOTAS MOVES THROUGH THE STATE. && .HYDROLOGY... ISSUED AT 323 AM CDT FRI MAY 31 2013 A FLASH FLOOD WATCH REMAINS IN EFFECT FOR BUTLER COUNTY AT THIS TIME DUE TO THE SMALL BREACH IN THE LEVEE ALONG THE BEAVER CREEK AT NEW HARTFORD. A WEATHER DISTURBANCE CAUSING AN AREA OF THUNDERSTORMS FROM KANSAS AND MISSOURI WILL ROTATE NORTHEAST TODAY...AFFECTING THE SOUTHEAST HALF OF THE FORECAST AREA LATER THIS MORNING THROUGH THE AFTERNOON HOURS. THE SOUTHEAST MAY SEE UP TO AN INCH OR MORE OF RAIN...BUT CURRENT FLASH FLOOD GUIDANCE HAS INCREASED TO 1.3 TO 1.5 INCHES PER HOUR AND 1.5 TO 2.25 INCHES IN 3 HOURS AT PRESENT. UNLESS THE STORMS BACK BUILD...THE RISK FOR ANY FLASH FLOODING REMAINS LOW TODAY ACROSS OUR FORECAST AREA. RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR NUMEROUS LOCATIONS THROUGHOUT THE HYDROLOGICAL SERVICES AREA FOR THE NEXT 5 TO 6 DAYS. IN THE SHORT TERM... THE OLD H500 LOW WILL CYCLE EAST IN THE NEXT 24 TO 48 HOURS AND THEN DEPART. WITH ONLY LIGHT SHOWERS OR ISOLATED THUNDER EXPECTED... RAINFALL WILL REMAIN LIGHT. FOLLOWING THAT...HIGH PRESSURE WILL KEEP THE REGION RAIN FREE TO MONDAY EVENING. THIS WILL SLOWLY ALLEVIATE THE SOME OF THE WATER ISSUES THOUGH LARGER MAIN STEM RIVER SYSTEMS WILL REMAIN ABOVE FLOOD STAGE THROUGH THE FORECAST PERIOD. ADDITIONAL MODERATE RAINFALL IS LIKELY BEGINNING LATE MONDAY NIGHT THROUGH THURSDAY WHICH WILL NEED TO BE WATCHED. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR SOUTHEASTERN BUTLER. && $$ SHORT TERM...FAB LONG TERM...REV AVIATION...BEERENDS HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1231 PM CDT FRI MAY 31 2013 .UPDATE... ISSUED AT 1220 PM CDT FRI MAY 31 2013 THE TWO SEPARATE MCS COMPLEXES HAVE MERGED AS EXPECTED. THUS THE SOUTHEAST HALF OF THE CWFA HAS THE BETTER CHANCE AT SEEING MODERATE RAIN WITH POSSIBLY VERY LOCALIZED HEAVY RAINFALL THROUGH THE AFTERNOON HOURS. NEW CONVECTION HAS DEVELOPED IN CENTRAL IOWA DUE TO CONVERGENCE OF THE WIND FIELD. THE MCS/LIFT TOOLS ARE SUGGESTING THIS NEW CONVECTION WILL MOVE INTO THE NORTHWEST PART OF THE CWFA BUT MAY REMAIN WEAK. THE MCS MAY INDUCE NEW CONVECTION IN FAR NORTHWEST ILLINOIS IN AREAS ALONG/EAST OF THE MISSISSIPPI. THE KEY TO CONVECTIVE TRENDS THIS AFTERNOON WILL BE WHETHER OR NOT CONVECTIVE TEMPERATURE IS ACHIEVED. FORECAST SOUNDINGS PLACE THE CONVECTIVE TEMPERATURE IN THE UPPER 70S WHICH IS THE CURRENT FCST MAX TEMPERATURE FOR MUCH OF THE AREA. STRONGER STORMS MAY BE POSSIBLE IF STRONGER DIFFERENTIAL HEATING CAN OCCUR ACROSS THE AREA. ..08.. UPDATE ISSUED AT 1036 AM CDT FRI MAY 31 2013 MCS TOOL FROM THE UKMET AND RAP ARE DEPICTING REASONABLY WELL THE CURRENT WX. THE FIRST MCS IS MOVING ACROSS THE SOUTHERN CWFA PRODUCING LIGHT TO MODERATE RAIN. SLIGHTLY DRIER AIR MIXING DOWN ON THE NORTH SIDE IS RESULTING IN A BRIEF PERIOD OF HIGH WINDS. THE TRENDS WITH THE RAP MODEL INDICATE THE NEW MCS ACROSS NORTHERN MISSOURI WILL SLOWLY MERGE WITH THE FIRST MCS THROUGH LATE MORNING. THE SOUTHEAST HALF OF THE CWFA WILL BE AFFECTED BY THE COMBINED MCS WITH IT EXITING THE CWFA BY EARLY EVENING. THUS THIS AREA WILL SEE THE MORE WIDESPREAD AND POTENTIALLY HEAVY RAINFALL. FLOW BASED OFF THE SFC OBS THROUGH 15Z INDICATE THE CLEAR AREAS ACROSS CENTRAL/NORTHERN IOWA WILL FILL WITH CLOUDS AS THE MORNING AND AFTERNOON PROGRESS. THE LIFT TOOL SUGGESTS THE POTENTIAL FOR NEW CONVECTION DEVELOPING AHEAD OF THE APPROACHING FRONT. AS FOR THE FLASH FLOOD HEADLINES...THEY ARE BEING LEFT IN PLACE FOR NOW. DEPENDING UPON HOW CONVECTION EVOLVES DURING THE LATE MORNING AND AFTERNOON...THE POSSIBILITY EXISTS THAT SOME HEADLINES MAY BE DROPPED. ..08.. UPDATE ISSUED AT 642 AM CDT FRI MAY 31 2013 IMPULSE MOVING AROUND THE BASE OF THE TROUGH WAS PUSHING INTO NW MO AND WILL BE HEADING NORTHEAST INTO THE DVN CWA LATER THIS MORNING. RAP MODEL INCREASES THE LOW LEVEL JET SO THUNDERSTORMS SHOULD CONTINUE TO SPREAD NORTHEAST INTO THE CWA THIS MORNING AND THEN INCREASE IN COVERAGE/INTENSITY THIS AFTERNOON. && .SYNOPSIS... ISSUED AT 315 AM CDT FRI MAY 31 2013 ALL IS QUIET FOR NOW ACROSS THE DVN CWA EARLY THIS MORNING BUT THUNDERSTORMS WERE LINED UP FROM NORTHEAST IL INTO AR MOVING NORTHEAST. OTHER THUNDERSTORMS WERE FORMING IN EXTREME NW MO AND NORTHEAST KS. A SUPERCELL WAS PRODUCING LARGE HAIL AROUND TOPEKA AND THESE STORMS WERE SPREADING EAST/NORTHEAST AT 40 KNOTS. STRONG LOW PRESSURE WAS SPINNING OVER THE DAKOTAS WITH A COLD FRONT IN THE PLAINS. CURRENT TEMPERATURES WERE IN THE 60S ACROSS IA...MO...KS AND IN THE 70S IN THE SOUTHERN PLAINS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 315 AM CDT FRI MAY 31 2013 HEADLINES...WILL CONTINUE THE FLASH FLOOD WATCH TODAY THROUGH TONIGHT. FORECAST FOCUS ON ACTIVE SEVERE WEATHER TODAY INTO THIS EVENING AND POTENTIAL FOR FLASH FLOODING ESPECIALLY WHERE TRAINING STORMS OCCUR. TODAY...SHOULD BE JUST ENOUGH SUNSHINE THIS MORNING TO PUSH TEMPERATURES INTO THE LOWER TO MID 70S THIS MORNING WITH THE CONVECTIVE TEMPERATURE REACHED. THUNDERSTORM ACTIVITY TO OUR SOUTHWEST SHOULD QUICKLY PUSH INTO THE DVN CWA THIS MORNING. AIR MASS WILL BE DESTABILIZING ALLOWING FOR THUNDERSTORMS TO INTENSIFY. MODERATE TO STRONG DEEP LAYER SHEAR AND DRY AIR ALOFT AND FREEZING LEVEL AT 11-12K FT SHOULD BE IDEAL FOR LARGE HAIL LATER THIS MORNING...POTENTIALLY QUARTER TO GOLF BALL SIZE. THIS AFTERNOON...WINDS ALOFT BECOME MORE UNIDIRECTIONAL WITH MID LEVEL WINDS INCREASING TO OVER 70 KNOTS. THIS WOULD FAVOR BOWING SEGMENTS AND DAMAGING WINDS GREATER THAN 70-80 MPH. WITH THE GROUND SATURATED THIS WOULD EASILY KNOCK OVER LARGE TREES. WITH SUCH STRONG SHEAR ANY DISCRETE THUNDERSTORM MAY BECOME SUPERCELLULAR WITH THE POTENTIAL FOR TORNADOES/LARGE HAIL...ALSO IN ANY LEWP/BOWING SEGMENTS. THUNDERSTORMS WILL BE FAST MOVING BUT ANY TRAINING OF STORMS WOULD ENHANCE THE FLASH FLOOD THREAT. OPERATIONAL MODELS SUGGEST THE HIGHEST RAIN TOTALS TO BE ACROSS ABOUT OUR SOUTHEAST HALF CWA. HIGHS TODAY AROUND 80. TONIGHT...ACTIVE THUNDERSTORMS THIS EVENING SHOULD BE MAINLY IN OUR IL COUNTIES WITH ACTIVITY THEN PUSHING EAST OF THE DVN CWA BY MIDNIGHT. COLD FRONT WILL BE MOVING INTO EASTERN IA LATER TONIGHT BRINGING COOLER AND DRIER AIR INTO EASTERN IA. MINIMUM TEMPERATURES WILL RANGE FROM THE UPPER 50S WEST TO MID 60S EAST. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 315 AM CDT FRI MAY 31 2013 SATURDAY...THE SURFACE COLD FRONT IS PROGGED TO BE NEAR THE MISSISSIPPI RIVER AT 12Z SATURDAY. THE COLD FRONT WILL CONTINUE TO SLIDE EAST DURING THE DAY AS THE UPPER TROUGH AXIS SHIFTS EAST ACROSS IOWA. THE CHANCE FOR SOME SHOWERS AND STORMS WILL CONTINUE IN THE VICINITY OF THE SURFACE FRONT EARLY SATURDAY. WILL HOLD ONTO SOME SLIGHT TO CHANCE CATEGORY PRECIPITATION PROBABILITIES THROUGH THE REMAINDER OF SATURDAY AS THE MID LEVEL BOUNDARY AND UPPER TROUGH ENERGY WORK ACROSS THE FORECAST AREA. HOWEVER ANY SHOWERS OR STORMS ON SATURDAY WILL BE LACKING IN HEAVY RAIN OR SEVERE POTENTIAL. TEMPERATURES SATURDAY ARE A BIT OF A CHALLENGE WITH CLOUD COVER AND COLDER AIR STARTING TO WORK IN BEHIND THE FRONT. SUNDAY THROUGH MONDAY...A BRIEF RESPITE IN THE ACTIVE WEATHER PATTERN IS IN STORE FROM SUNDAY INTO MONDAY. COOLER AND DRIER AIR WILL MOVE IN AS UPPER RIDGING AND SURFACE HIGH PRESSURE SPREAD ACROSS THE REGION. TEMPERATURES ON SUNDAY LOOK TO BE AROUND 10 DEGREES BELOW NORMAL...WITH MORNING LOWS IN THE LOWER TO MIDDLE 50S AND HIGHS IN THE MIDDLE TO UPPER 60S. MONDAY MORNING TEMPERATURES COULD BOTTOM OUT IN THE 40S ACROSS PORTIONS OF THE FORECAST AREA. TUESDAY THROUGH THURSDAY...YET ANOTHER UPPER LEVEL SYSTEM WILL APPROACH THE MIDWEST MID TO LATE NEXT WEEK. LEAD SHORTWAVE ENERGY COULD KICK OFF SOME PRECIPITATION AS EARLY AS TUESDAY...WITH INCREASING SHOWER AND THUNDERSTORM CHANCES BY WEDNESDAY. A WARMING TREND WILL BRING TEMPERATURES BACK CLOSER TO NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1220 PM CDT FRI MAY 31 2013 TWO SEPARATE THUNDERSTORM COMPLEXES HAVE MERGED OVER SOUTHEAST IOWA AND WESTERN ILLINOIS. GENERALLY VFR WX WILL BE SEEN THROUGH 00Z/01. TSRA WILL BE POSSIBLE WITH KMLI/KBRL HAVING A BETTER CHANCE THAN KCID/KDBQ. IF A TSRA AFFECTS A TAF SITE A BRIEF PERIOD OF MVFR CONDITIONS ARE POSSIBLE. AFT 00Z/01 VFR CONDITIONS ARE EXPECTED TO CONTINUE. WET GROUND MAY RESULT IN MVFR CONDITIONS DVLPG AFT 06Z/01 DUE TO MAINLY CLEAR SKIES AND WINDS UNDER 10 KNOTS. ..08.. && .HYDROLOGY... ISSUED AT 315 AM CDT FRI MAY 31 2013 WITH MANY RIVERS IN MODERATE TO MAJOR FLOOD AND THE GROUND COMPLETELY SATURATED THE THREAT FOR FLASH FLOODING WILL REMAIN TODAY INTO THIS EVENING...ESPECIALLY WHERE TRAINING OF STORMS OCCUR. THE HEAVIEST RAINS SHOULD BE ACROSS THE SOUTHEAST HALF OF THE DVN CWA WHERE MANY AREAS SHOULD RECEIVE AT LEAST AN INCH OF RAIN TODAY INTO THIS EVENING. HOWEVER...SEVERAL INCHES OF RAIN WOULD PRODUCE SEVERE FLASH FLOODING ESPECIALLY IF STORMS CAN TRAIN ACROSS THE SAME LOCATIONS. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BENTON-BUCHANAN- CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA- JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BUREAU-CARROLL- HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER- PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR CLARK-SCOTLAND. && $$ UPDATE...08 SYNOPSIS...HAASE SHORT TERM...HAASE LONG TERM...STOFLET AVIATION...08 HYDROLOGY...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1048 AM CDT FRI MAY 31 2013 .UPDATE... ISSUED AT 1036 AM CDT FRI MAY 31 2013 MCS TOOL FROM THE UKMET AND RAP ARE DEPICTING REASONABLY WELL THE CURRENT WX. THE FIRST MCS IS MOVING ACROSS THE SOUTHERN CWFA PRODUCING LIGHT TO MODERATE RAIN. SLIGHTLY DRIER AIR MIXING DOWN ON THE NORTH SIDE IS RESULTING IN A BRIEF PERIOD OF HIGH WINDS. THE TRENDS WITH THE RAP MODEL INDICATE THE NEW MCS ACROSS NORTHERN MISSOURI WILL SLOWLY MERGE WITH THE FIRST MCS THROUGH LATE MORNING. THE SOUTHEAST HALF OF THE CWFA WILL BE AFFECTED BY THE COMBINED MCS WITH IT EXITING THE CWFA BY EARLY EVENING. THUS THIS AREA WILL SEE THE MORE WIDESPREAD AND POTENTIALLY HEAVY RAINFALL. FLOW BASED OFF THE SFC OBS THROUGH 15Z INDICATE THE CLEAR AREAS ACROSS CENTRAL/NORTHERN IOWA WILL FILL WITH CLOUDS AS THE MORNING AND AFTERNOON PROGRESS. THE LIFT TOOL SUGGESTS THE POTENTIAL FOR NEW CONVECTION DEVELOPING AHEAD OF THE APPROACHING FRONT. AS FOR THE FLASH FLOOD HEADLINES...THEY ARE BEING LEFT IN PLACE FOR NOW. DEPENDING UPON HOW CONVECTION EVOLVES DURING THE LATE MORNING AND AFTERNOON...THE POSSIBILITY EXISTS THAT SOME HEADLINES MAY BE DROPPED. ..08.. UPDATE ISSUED AT 642 AM CDT FRI MAY 31 2013 IMPULSE MOVING AROUND THE BASE OF THE TROUGH WAS PUSHING INTO NW MO AND WILL BE HEADING NORTHEAST INTO THE DVN CWA LATER THIS MORNING. RAP MODEL INCREASES THE LOW LEVEL JET SO THUNDERSTORMS SHOULD CONTINUE TO SPREAD NORTHEAST INTO THE CWA THIS MORNING AND THEN INCREASE IN COVERAGE/INTENSITY THIS AFTERNOON. && .SYNOPSIS... ISSUED AT 315 AM CDT FRI MAY 31 2013 ALL IS QUIET FOR NOW ACROSS THE DVN CWA EARLY THIS MORNING BUT THUNDERSTORMS WERE LINED UP FROM NORTHEAST IL INTO AR MOVING NORTHEAST. OTHER THUNDERSTORMS WERE FORMING IN EXTREME NW MO AND NORTHEAST KS. A SUPERCELL WAS PRODUCING LARGE HAIL AROUND TOPEKA AND THESE STORMS WERE SPREADING EAST/NORTHEAST AT 40 KNOTS. STRONG LOW PRESSURE WAS SPINNING OVER THE DAKOTAS WITH A COLD FRONT IN THE PLAINS. CURRENT TEMPERATURES WERE IN THE 60S ACROSS IA...MO...KS AND IN THE 70S IN THE SOUTHERN PLAINS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 315 AM CDT FRI MAY 31 2013 HEADLINES...WILL CONTINUE THE FLASH FLOOD WATCH TODAY THROUGH TONIGHT. FORECAST FOCUS ON ACTIVE SEVERE WEATHER TODAY INTO THIS EVENING AND POTENTIAL FOR FLASH FLOODING ESPECIALLY WHERE TRAINING STORMS OCCUR. TODAY...SHOULD BE JUST ENOUGH SUNSHINE THIS MORNING TO PUSH TEMPERATURES INTO THE LOWER TO MID 70S THIS MORNING WITH THE CONVECTIVE TEMPERATURE REACHED. THUNDERSTORM ACTIVITY TO OUR SOUTHWEST SHOULD QUICKLY PUSH INTO THE DVN CWA THIS MORNING. AIR MASS WILL BE DESTABILIZING ALLOWING FOR THUNDERSTORMS TO INTENSIFY. MODERATE TO STRONG DEEP LAYER SHEAR AND DRY AIR ALOFT AND FREEZING LEVEL AT 11-12K FT SHOULD BE IDEAL FOR LARGE HAIL LATER THIS MORNING...POTENTIALLY QUARTER TO GOLF BALL SIZE. THIS AFTERNOON...WINDS ALOFT BECOME MORE UNIDIRECTIONAL WITH MID LEVEL WINDS INCREASING TO OVER 70 KNOTS. THIS WOULD FAVOR BOWING SEGMENTS AND DAMAGING WINDS GREATER THAN 70-80 MPH. WITH THE GROUND SATURATED THIS WOULD EASILY KNOCK OVER LARGE TREES. WITH SUCH STRONG SHEAR ANY DISCRETE THUNDERSTORM MAY BECOME SUPERCELLULAR WITH THE POTENTIAL FOR TORNADOES/LARGE HAIL...ALSO IN ANY LEWP/BOWING SEGMENTS. THUNDERSTORMS WILL BE FAST MOVING BUT ANY TRAINING OF STORMS WOULD ENHANCE THE FLASH FLOOD THREAT. OPERATIONAL MODELS SUGGEST THE HIGHEST RAIN TOTALS TO BE ACROSS ABOUT OUR SOUTHEAST HALF CWA. HIGHS TODAY AROUND 80. TONIGHT...ACTIVE THUNDERSTORMS THIS EVENING SHOULD BE MAINLY IN OUR IL COUNTIES WITH ACTIVITY THEN PUSHING EAST OF THE DVN CWA BY MIDNIGHT. COLD FRONT WILL BE MOVING INTO EASTERN IA LATER TONIGHT BRINGING COOLER AND DRIER AIR INTO EASTERN IA. MINIMUM TEMPERATURES WILL RANGE FROM THE UPPER 50S WEST TO MID 60S EAST. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 315 AM CDT FRI MAY 31 2013 SATURDAY...THE SURFACE COLD FRONT IS PROGGED TO BE NEAR THE MISSISSIPPI RIVER AT 12Z SATURDAY. THE COLD FRONT WILL CONTINUE TO SLIDE EAST DURING THE DAY AS THE UPPER TROUGH AXIS SHIFTS EAST ACROSS IOWA. THE CHANCE FOR SOME SHOWERS AND STORMS WILL CONTINUE IN THE VICINITY OF THE SURFACE FRONT EARLY SATURDAY. WILL HOLD ONTO SOME SLIGHT TO CHANCE CATEGORY PRECIPITATION PROBABILITIES THROUGH THE REMAINDER OF SATURDAY AS THE MID LEVEL BOUNDARY AND UPPER TROUGH ENERGY WORK ACROSS THE FORECAST AREA. HOWEVER ANY SHOWERS OR STORMS ON SATURDAY WILL BE LACKING IN HEAVY RAIN OR SEVERE POTENTIAL. TEMPERATURES SATURDAY ARE A BIT OF A CHALLENGE WITH CLOUD COVER AND COLDER AIR STARTING TO WORK IN BEHIND THE FRONT. SUNDAY THROUGH MONDAY...A BRIEF RESPITE IN THE ACTIVE WEATHER PATTERN IS IN STORE FROM SUNDAY INTO MONDAY. COOLER AND DRIER AIR WILL MOVE IN AS UPPER RIDGING AND SURFACE HIGH PRESSURE SPREAD ACROSS THE REGION. TEMPERATURES ON SUNDAY LOOK TO BE AROUND 10 DEGREES BELOW NORMAL...WITH MORNING LOWS IN THE LOWER TO MIDDLE 50S AND HIGHS IN THE MIDDLE TO UPPER 60S. MONDAY MORNING TEMPERATURES COULD BOTTOM OUT IN THE 40S ACROSS PORTIONS OF THE FORECAST AREA. TUESDAY THROUGH THURSDAY...YET ANOTHER UPPER LEVEL SYSTEM WILL APPROACH THE MIDWEST MID TO LATE NEXT WEEK. LEAD SHORTWAVE ENERGY COULD KICK OFF SOME PRECIPITATION AS EARLY AS TUESDAY...WITH INCREASING SHOWER AND THUNDERSTORM CHANCES BY WEDNESDAY. A WARMING TREND WILL BRING TEMPERATURES BACK CLOSER TO NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 642 AM CDT FRI MAY 31 2013 IFR/MVFR CONDITIONS THIS MORNING WITH ANOTHER LARGE AND VIGOROUS CONVECTIVE COMPLEX IMPACTING ALL TERMINALS BETWEEN 31/15Z AND 01/03Z WITH PERIODS OF MVF OR EVEN IFR CONDITIONS IN THE HEAVIEST AND STRONGEST STORMS DUE TO HEAVY RAINS. SOUTH WINDS WILL CONTINUE OUTSIDE OF ANY STORMS AT 5 TO 10 KTS. STRONGEST STORMS MAY ALSO PRODUCE WIND GUSTS AOA 40 KTS AND POSSIBLY LARGE HAIL. && .HYDROLOGY... ISSUED AT 315 AM CDT FRI MAY 31 2013 WITH MANY RIVERS IN MODERATE TO MAJOR FLOOD AND THE GROUND COMPLETELY SATURATED THE THREAT FOR FLASH FLOODING WILL REMAIN TODAY INTO THIS EVENING...ESPECIALLY WHERE TRAINING OF STORMS OCCUR. THE HEAVIEST RAINS SHOULD BE ACROSS THE SOUTHEAST HALF OF THE DVN CWA WHERE MANY AREAS SHOULD RECEIVE AT LEAST AN INCH OF RAIN TODAY INTO THIS EVENING. HOWEVER...SEVERAL INCHES OF RAIN WOULD PRODUCE SEVERE FLASH FLOODING ESPECIALLY IF STORMS CAN TRAIN ACROSS THE SAME LOCATIONS. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BENTON-BUCHANAN- CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA- JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BUREAU-CARROLL- HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER- PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR CLARK-SCOTLAND. && $$ UPDATE...08 SYNOPSIS...HAASE SHORT TERM...HAASE LONG TERM...STOFLET AVIATION...HAASE HYDROLOGY...HAASE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
649 AM CDT FRI MAY 31 2013 .UPDATE... ISSUED AT 642 AM CDT FRI MAY 31 2013 IMPULSE MOVING AROUND THE BASE OF THE TROUGH WAS PUSHING INTO NW MO AND WILL BE HEADING NORTHEAST INTO THE DVN CWA LATER THIS MORING. RAP MODEL INCREASES THE LOW LEVEL JET SO THUNDERSTORMS SHOULD CONTINUE TO SPREAD NORTHEAST INTO THE CWA THIS MORNING AND THEN INCREASE IN COVERAGE/INTENSITY THIS AFTERNOON. && .SYNOPSIS... ISSUED AT 315 AM CDT FRI MAY 31 2013 ALL IS QUIET FOR NOW ACROSS THE DVN CWA EARLY THIS MORNING BUT THUNDERSTORMS WERE LINED UP FROM NORTHEAST IL INTO AR MOVING NORTHEAST. OTHER THUNDERSTORMS WERE FORMING IN EXTREME NW MO AND NORTHEAST KS. A SUPERCELL WAS PRODUCING LARGE HAIL AROUND TOPEKA AND THESE STORMS WERE SPREADING EAST/NORTHEAST AT 40 KNOTS. STRONG LOW PRESSURE WAS SPINNING OVER THE DAKOTAS WITH A COLD FRONT IN THE PLAINS. CURRENT TEMPERATURES WERE IN THE 60S ACROSS IA...MO...KS AND IN THE 70S IN THE SOUTHERN PLAINS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 315 AM CDT FRI MAY 31 2013 HEADLINES...WILL CONTINUE THE FLASH FLOOD WATCH TODAY THROUGH TONIGHT. FORECAST FOCUS ON ACTIVE SEVERE WEATHER TODAY INTO THIS EVENING AND POTENTIAL FOR FLASH FLOODING ESPECIALLY WHERE TRAINING STORMS OCCUR. TODAY...SHOULD BE JUST ENOUGH SUNSHINE THIS MORNING TO PUSH TEMPERATURES INTO THE LOWER TO MID 70S THIS MORNING WITH THE CONVECTIVE TEMPERATURE REACHED. THUNDERSTORM ACTIVITY TO OUR SOUTHWEST SHOULD QUICKLY PUSH INTO THE DVN CWA THIS MORNING. AIR MASS WILL BE DESTABILIZING ALLOWING FOR THUNDERSTORMS TO INTENSIFY. MODERATE TO STRONG DEEP LAYER SHEAR AND DRY AIR ALOFT AND FREEZING LEVEL AT 11-12K FT SHOULD BE IDEAL FOR LARGE HAIL LATER THIS MORNING...POTENTIALLY QUARTER TO GOLF BALL SIZE. THIS AFTERNOON...WINDS ALOFT BECOME MORE UNIDIRECTIONAL WITH MID LEVEL WINDS INCREASING TO OVER 70 KNOTS. THIS WOULD FAVOR BOWING SEGMENTS AND DAMAGING WINDS GREATER THAN 70-80 MPH. WITH THE GROUND SATURATED THIS WOULD EASILY KNOCK OVER LARGE TREES. WITH SUCH STRONG SHEAR ANY DISCRETE THUNDERSTORM MAY BECOME SUPERCELLULAR WITH THE POTENTIAL FOR TORNADOES/LARGE HAIL...ALSO IN ANY LEWP/BOWING SEGMENTS. THUNDERSTORMS WILL BE FAST MOVING BUT ANY TRAINING OF STORMS WOULD ENHANCE THE FLASH FLOOD THREAT. OPERATIONAL MODELS SUGGEST THE HIGHEST RAIN TOTALS TO BE ACROSS ABOUT OUR SOUTHEAST HALF CWA. HIGHS TODAY AROUND 80. TONIGHT...ACTIVE THUNDERSTORMS THIS EVENING SHOULD BE MAINLY IN OUR IL COUNTIES WITH ACTIVITY THEN PUSHING EAST OF THE DVN CWA BY MIDNIGHT. COLD FRONT WILL BE MOVING INTO EASTERN IA LATER TONIGHT BRINGING COOLER AND DRIER AIR INTO EASTERN IA. MINIMUM TEMPERATURES WILL RANGE FROM THE UPPER 50S WEST TO MID 60S EAST. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 315 AM CDT FRI MAY 31 2013 SATURDAY...THE SURFACE COLD FRONT IS PROGGED TO BE NEAR THE MISSISSIPPI RIVER AT 12Z SATURDAY. THE COLD FRONT WILL CONTINUE TO SLIDE EAST DURING THE DAY AS THE UPPER TROUGH AXIS SHIFTS EAST ACROSS IOWA. THE CHANCE FOR SOME SHOWERS AND STORMS WILL CONTINUE IN THE VICINITY OF THE SURFACE FRONT EARLY SATURDAY. WILL HOLD ONTO SOME SLIGHT TO CHANCE CATEGORY PRECIPITATION PROBABILITIES THROUGH THE REMAINDER OF SATURDAY AS THE MID LEVEL BOUNDARY AND UPPER TROUGH ENERGY WORK ACROSS THE FORECAST AREA. HOWEVER ANY SHOWERS OR STORMS ON SATURDAY WILL BE LACKING IN HEAVY RAIN OR SEVERE POTENTIAL. TEMPERATURES SATURDAY ARE A BIT OF A CHALLENGE WITH CLOUD COVER AND COLDER AIR STARTING TO WORK IN BEHIND THE FRONT. SUNDAY THROUGH MONDAY...A BRIEF RESPITE IN THE ACTIVE WEATHER PATTERN IS IN STORE FROM SUNDAY INTO MONDAY. COOLER AND DRIER AIR WILL MOVE IN AS UPPER RIDGING AND SURFACE HIGH PRESSURE SPREAD ACROSS THE REGION. TEMPERATURES ON SUNDAY LOOK TO BE AROUND 10 DEGREES BELOW NORMAL...WITH MORNING LOWS IN THE LOWER TO MIDDLE 50S AND HIGHS IN THE MIDDLE TO UPPER 60S. MONDAY MORNING TEMPERATURES COULD BOTTOM OUT IN THE 40S ACROSS PORTIONS OF THE FORECAST AREA. TUESDAY THROUGH THURSDAY...YET ANOTHER UPPER LEVEL SYSTEM WILL APPROACH THE MIDWEST MID TO LATE NEXT WEEK. LEAD SHORTWAVE ENERGY COULD KICK OFF SOME PRECIPITATION AS EARLY AS TUESDAY...WITH INCREASING SHOWER AND THUNDERSTORM CHANCES BY WEDNESDAY. A WARMING TREND WILL BRING TEMPERATURES BACK CLOSER TO NORMAL. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 642 AM CDT FRI MAY 31 2013 IFR/MVFR CONDITIONS THIS MORNING WITH ANOTHER LARGE AND VIGOROUS CONVECTIVE COMPLEX IMPACTING ALL TERMINALS BETWEEN 31/15Z AND 01/03Z WITH PERIODS OF MVF OR EVEN IFR CONDITIONS IN THE HEAVIEST AND STRONGEST STORMS DUE TO HEAVY RAINS. SOUTH WINDS WILL CONTINUE OUTSIDE OF ANY STORMS AT 5 TO 10 KTS. STRONGEST STORMS MAY ALSO PRODUCE WIND GUSTS AOA 40 KTS AND POSSIBLY LARGE HAIL. && .HYDROLOGY... ISSUED AT 315 AM CDT FRI MAY 31 2013 WITH MANY RIVERS IN MODERATE TO MAJOR FLOOD AND THE GROUND COMPLETELY SATURATED THE THREAT FOR FLASH FLOODING WILL REMAIN TODAY INTO THIS EVENING...ESPECIALLY WHERE TRAINING OF STORMS OCCUR. THE HEAVIEST RAINS SHOULD BE ACROSS THE SOUTHEAST HALF OF THE DVN CWA WHERE MANY AREAS SHOULD RECEIVE AT LEAST AN INCH OF RAIN TODAY INTO THIS EVENING. HOWEVER...SEVERAL INCHES OF RAIN WOULD PRODUCE SEVERE FLASH FLOODING ESPECIALLY IF STORMS CAN TRAIN ACROSS THE SAME LOCATIONS. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BENTON-BUCHANAN- CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA- JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA- MUSCATINE-SCOTT-VAN BUREN-WASHINGTON. IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR BUREAU-CARROLL- HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER- PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE. MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR CLARK-SCOTLAND. && $$ UPDATE...HAASE SYNOPSIS...HAASE SHORT TERM...HAASE LONG TERM...STOFLET AVIATION...HAASE HYDROLOGY...HAASE
AREA FORECAST DISCUSSION
NWS DES MOINES IA
648 AM CDT FRI MAY 31 2013 .SHORT TERM.../TODAY /... ISSUED AT 323 AM CDT FRI MAY 31 2013 THUNDERSTORMS HAVE DEVELOPED IN NORTHERN MISSOURI ALONG A ZONE OF WARM AIR ADVECTION AND A LOW LEVEL JET. JUST NORTH OF THAT AREA BUT STILL IN MO SOME WEAKER STORMS HAVE DEVELOPED AND ARE DISSIPATING. THE STORMS HAVE AN EAST/NORTHEASTERLY TRACK AND WILL EVENTUALLY CLIP FAR SOUTHERN IOWA. THE WEAKENING STORMS JUST ACROSS OUR BORDER WILL LIKELY ONLY PRODUCE SOME SHOWERS ACROSS THE FAR SOUTH IN THE NEXT FEW HOURS. A VORT MAX AND SHORT WAVE WILL PIVOT AROUND THE UPPER LOW OVER THE EASTERN DAKOTAS AND THIS WILL SHIFT THE STORMS THAT ARE A LITTLE FURTHER SOUTH IN NORTHERN MO RIGHT INTO SOUTHERN/SOUTHEAST IOWA BY MID TO LATE MORNING THEN INTO EASTERN IOWA BY EARLY AFTERNOON. BY MID TO LATE AFTERNOON A STRONGER SHORT WAVE WILL PUSH INTO WESTERN IOWA WHICH WILL BRING MORE THUNDERSTORMS TO THAT AREA AND THIS WILL SHIFT EAST FROM 21Z INTO THE EVENING HOURS. THERE WILL BE A TIME IN THE AFTERNOON WHERE SHOWERS AND STORMS WILL STILL BE OVER EASTERN IOWA AND ADDITIONAL STORMS DEVELOPING OVER THE WEST WITH CENTRAL IOWA DRY. LAPSE RATES OVER SOUTHERN IOWA AND ABOUT THE SOUTHEAST THIRD OF THE STATE ARE PRETTY STEEP THIS AFTERNOON AND THERE IS MORE THAN SUFFICIENT SHEAR FOR A FEW SEVERE STORMS. IN ADDITION...HEAVY RAINFALL IS LIKELY WITH THE STORMS AS WELL...MAINLY OVER THE FAR EAST AND SOUTHEAST. YESTERDAY THE HI RES NMM EAST REALLY HAD THE PRECIP AREAS PEGGED AND ALSO HAD DECENT TIMING OF THE PRECIP. I STILL LIKE WHAT THIS MODEL DOES WITH THE PRECIP TODAY HOWEVER IT IS NOT PICKING UP THE MO CONVECTION VERY WELL AT THIS TIME. IT IS ABOUT 3 HOURS LATER WITH THAT SO I BLENDED NMM POPS WITH THE HRRR AND NAM12. AS FOR TEMPS...THERE SHOULD BE SLIGHTLY WARMER AIR OVER THE SOUTH AND SOUTHEAST TODAY SO I NUDGED HIGHS UP IN THESE AREAS. THE NORTH SHOULD SEE TEMPS A FEW DEGREES WARMER AS WELL. .LONG TERM.../TONIGHT THROUGH WEDNESDAY/... ISSUED AT 323 AM CDT FRI MAY 31 2013 FEWER CONCERNS FOR THE NEXT SEVERAL DAYS AS UPPER TROUGH BEGINS TO SWING EAST. ALREADY THE MAIN H850 MOISTURE CHANNEL HAS SHIFTED EAST OF THE AREA WITH THE LINE OF STRONGER THUNDERSTORMS THAT EXITED THE EASTERN PORTION OF THE FORECAST AREA EARLY THIS EVENING. HOWEVER THERE WILL STILL BE SOME RESIDUAL CONVECTION FAR SOUTHEAST EARLY IN THE PERIOD TONIGHT...ENDING QUICKLY AND MOVING EAST BY 06Z. MEANWHILE...THE MAIN FEATURE YET LATE TONIGHT AND EARLY SATURDAY WILL BE THE OLD H500 LOW WHICH IS LIKELY TO SPIN UP SOME SHOWERS AND ISOLATED THUNDER AS IT MOVES ACROSS THE REGION TOMORROW AS THE COLD POOL UNDERNEATH THE UPPER LEVEL LOW DROPS SOUTHEAST INTO THE REGION. STEEP LAPSE RATES WILL BE IN THE AREA OF THE LOW ON SATURDAY AND OVER THE NORTH INTO MN AND WESTERN WI NON SUPERCELL TORNADO PARAMETER IS INCREASING. SOMETHING TO KEEP AN EYE ON THERE...AN ISOLATED FUNNEL CLOUD OR LANDSPOUT MAY BE POSSIBLE IF LAPSE RATES BECOME STEEP ENOUGH IN THE AFTERNOON HOURS. OTHERWISE...THE OLD LOW WILL PULL EAST SATURDAY NIGHT AND SUNDAY LEAVING THE REGION WITH COOLER AIR FOR THE FIRST PART OF JUNE. THIS WILL KEEP THE AREA IN THE 60S FOR HIGHS ON SUNDAY WITH MID 40S NORTH AND LOWER 50S SOUTH FOR LOWS ON MONDAY MORNING. AS THE HIGH MOVES EAST...HIGHS WILL RESPOND INTO THE LOWER 70S FOR MONDAY. MONDAY NIGHT WARM AIR ADVECTION AND MID LEVEL MOISTURE BEGIN TO INCREASE AGAIN...RESULTING IN LATE NIGHT/EARLY MORNING ELEVATED CONVECTION. TUESDAY LOOKS ACTIVE AS A STRONGER WAVE ROTATES NORTHEAST INTO THE STATE. THIS WILL RESULT IN MORE WIDESPREAD THUNDERSTORMS WITH RAINFALL AMOUNTS POSSIBLY APPROACHING ONE INCH IN SOME PLACES. THIS WILL CERTAINLY KEEP SOIL MOISTURE HIGH...AND ALSO RESULT IN RENEWED RIVER RISES. THE SYSTEM WILL GRADUALLY EXIT THE REGION BY THURSDAY. THE LARGER SCALE FLOW PATTERN REMAINS GENERALLY WESTERLY AT MID TO HIGH LEVELS. THIS PROMOTES LEE SIDE TROUGHING AND WITH A CONTINUED SUB TROPICAL HIGH ANCHORED OFF THE EAST COAST A WETTER THAN NORMAL PATTERN IS LIKELY TO CONTINUE OVER THE NEXT 7 TO 10 DAYS. ANOTHER INTERESTING WRINKLE IS A TROPICAL DISTURBANCE IN THE GULF OF MEXICO BY NEXT THUR/FRIDAY WHICH MAY EVENTUALLY BE PULLED NORTH TOWARD THE MID MISSISSIPPI RIVER VALLEY. HIGH TEMPERATURES OVER THE NEXT WEEK WILL LIKELY REMAIN IN THE 70S ON AVERAGE AND NOT BREAK OUT OF A 65 TO 75 RANGE BY TOO MUCH IF ANY. ANOTHER NOTE WITH OUR CURRENT WET WEATHER WILL BE CLOUD COVER. UNLESS WE HAVE A STRONG HIGH AND STRONG SUBSIDENCE...MOST LATE MORNINGS AND AFTERNOONS ON ANY SUNNY DAY WILL GO SCT TO BKN BY AFTERNOON. && .AVIATION...31/12Z ISSUED AT 648 AM CDT THU MAY 30 2013 THERE WILL BE A COUPLE OF UPPER LEVEL DISTURBANCES AFFECTING TAF LOCATIONS TODAY. THIS MORNING...MAINLY AFTER 15Z ONE DISTURBANCE WILL MOVE ACROSS THE AREA MOVING SHOWERS AND THUNDERSTORMS FROM NORTHERN MO INTO SOUTHEAST IA. THIS SHOULD MAINLY AFFECT KOTM BUT COULD EXTEND COVERAGE TO KDSM AND KALO AS WELL. THIS AFTERNOON A STRONGER DISTURBANCE WILL SHIFT ACROSS IOWA BETWEEN 21Z AND 05Z BRINGING ANOTHER CHANCE FOR THUNDERSTORMS. THESE WOULD BE MORE LIKELY TO PRODUCE HEAVY RAINFALL AS WELL AS STRONG WIND AND POSSIBLY HAIL. IFR CONDITIONS ARE EXPECTED THROUGH 15-16Z THEN MVFR CONDITIONS WITH STORMS OTHERWISE MOST LOCATIONS SHOULD BE VFR. SFC WIND WILL BE SOUTHERLY AT 15-25KTS. && .HYDROLOGY... ISSUED AT 323 AM CDT FRI MAY 31 2013 A FLASH FLOOD WATCH REMAINS IN EFFECT FOR BUTLER COUNTY AT THIS TIME DUE TO THE SMALL BREACH IN THE LEVEE ALONG THE BEAVER CREEK AT NEW HARTFORD. A WEATHER DISTURBANCE CAUSING AN AREA OF THUNDERSTORMS FROM KANSAS AND MISSOURI WILL ROTATE NORTHEAST TODAY...AFFECTING THE SOUTHEAST HALF OF THE FORECAST AREA LATER THIS MORNING THROUGH THE AFTERNOON HOURS. THE SOUTHEAST MAY SEE UP TO AN INCH OR MORE OF RAIN...BUT CURRENT FLASH FLOOD GUIDANCE HAS INCREASED TO 1.3 TO 1.5 INCHES PER HOUR AND 1.5 TO 2.25 INCHES IN 3 HOURS AT PRESENT. UNLESS THE STORMS BACK BUILD...THE RISK FOR ANY FLASH FLOODING REMAINS LOW TODAY ACROSS OUR FORECAST AREA. RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR NUMEROUS LOCATIONS THROUGHOUT THE HYDROLOGICAL SERVICES AREA FOR THE NEXT 5 TO 6 DAYS. IN THE SHORT TERM... THE OLD H500 LOW WILL CYCLE EAST IN THE NEXT 24 TO 48 HOURS AND THEN DEPART. WITH ONLY LIGHT SHOWERS OR ISOLATED THUNDER EXPECTED... RAINFALL WILL REMAIN LIGHT. FOLLOWING THAT...HIGH PRESSURE WILL KEEP THE REGION RAIN FREE TO MONDAY EVENING. THIS WILL SLOWLY ALLEVIATE THE SOME OF THE WATER ISSUES THOUGH LARGER MAIN STEM RIVER SYSTEMS WILL REMAIN ABOVE FLOOD STAGE THROUGH THE FORECAST PERIOD. ADDITIONAL MODERATE RAINFALL IS LIKELY BEGINNING LATE MONDAY NIGHT THROUGH THURSDAY WHICH WILL NEED TO BE WATCHED. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THIS EVENING FOR BUTLER. && $$ SHORT TERM...FAB LONG TERM...REV AVIATION...FAB HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
323 AM CDT FRI MAY 31 2013 .SHORT TERM.../TODAY /... ISSUED AT 323 AM CDT FRI MAY 31 2013 THUNDERSTORMS HAVE DEVELOPED IN NORTHERN MISSOURI ALONG A ZONE OF WARM AIR ADVECTION AND A LOW LEVEL JET. JUST NORTH OF THAT AREA BUT STILL IN MO SOME WEAKER STORMS HAVE DEVELOPED AND ARE DISSIPATING. THE STORMS HAVE AN EAST/NORTHEASTERLY TRACK AND WILL EVENTUALLY CLIP FAR SOUTHERN IOWA. THE WEAKENING STORMS JUST ACROSS OUR BORDER WILL LIKELY ONLY PRODUCE SOME SHOWERS ACROSS THE FAR SOUTH IN THE NEXT FEW HOURS. A VORT MAX AND SHORT WAVE WILL PIVOT AROUND THE UPPER LOW OVER THE EASTERN DAKOTAS AND THIS WILL SHIFT THE STORMS THAT ARE A LITTLE FURTHER SOUTH IN NORTHERN MO RIGHT INTO SOUTHERN/SOUTHEAST IOWA BY MID TO LATE MORNING THEN INTO EASTERN IOWA BY EARLY AFTERNOON. BY MID TO LATE AFTERNOON A STRONGER SHORT WAVE WILL PUSH INTO WESTERN IOWA WHICH WILL BRING MORE THUNDERSTORMS TO THAT AREA AND THIS WILL SHIFT EAST FROM 21Z INTO THE EVENING HOURS. THERE WILL BE A TIME IN THE AFTERNOON WHERE SHOWERS AND STORMS WILL STILL BE OVER EASTERN IOWA AND ADDITIONAL STORMS DEVELOPING OVER THE WEST WITH CENTRAL IOWA DRY. LAPSE RATES OVER SOUTHERN IOWA AND ABOUT THE SOUTHEAST THIRD OF THE STATE ARE PRETTY STEEP THIS AFTERNOON AND THERE IS MORE THAN SUFFICIENT SHEAR FOR A FEW SEVERE STORMS. IN ADDITION...HEAVY RAINFALL IS LIKELY WITH THE STORMS AS WELL...MAINLY OVER THE FAR EAST AND SOUTHEAST. YESTERDAY THE HI RES NMM EAST REALLY HAD THE PRECIP AREAS PEGGED AND ALSO HAD DECENT TIMING OF THE PRECIP. I STILL LIKE WHAT THIS MODEL DOES WITH THE PRECIP TODAY HOWEVER IT IS NOT PICKING UP THE MO CONVECTION VERY WELL AT THIS TIME. IT IS ABOUT 3 HOURS LATER WITH THAT SO I BLENDED NMM POPS WITH THE HRRR AND NAM12. AS FOR TEMPS...THERE SHOULD BE SLIGHTLY WARMER AIR OVER THE SOUTH AND SOUTHEAST TODAY SO I NUDGED HIGHS UP IN THESE AREAS. THE NORTH SHOULD SEE TEMPS A FEW DEGREES WARMER AS WELL. .LONG TERM.../TONIGHT THROUGH WEDNESDAY/... ISSUED AT 323 AM CDT FRI MAY 31 2013 FEWER CONCERNS FOR THE NEXT SEVERAL DAYS AS UPPER TROUGH BEGINS TO SWING EAST. ALREADY THE MAIN H850 MOISTURE CHANNEL HAS SHIFTED EAST OF THE AREA WITH THE LINE OF STRONGER THUNDERSTORMS THAT EXITED THE EASTERN PORTION OF THE FORECAST AREA EARLY THIS EVENING. HOWEVER THERE WILL STILL BE SOME RESIDUAL CONVECTION FAR SOUTHEAST EARLY IN THE PERIOD TONIGHT...ENDING QUICKLY AND MOVING EAST BY 06Z. MEANWHILE...THE MAIN FEATURE YET LATE TONIGHT AND EARLY SATURDAY WILL BE THE OLD H500 LOW WHICH IS LIKELY TO SPIN UP SOME SHOWERS AND ISOLATED THUNDER AS IT MOVES ACROSS THE REGION TOMORROW AS THE COLD POOL UNDERNEATH THE UPPER LEVEL LOW DROPS SOUTHEAST INTO THE REGION. STEEP LAPSE RATES WILL BE IN THE AREA OF THE LOW ON SATURDAY AND OVER THE NORTH INTO MN AND WESTERN WI NON SUPERCELL TORNADO PARAMETER IS INCREASING. SOMETHING TO KEEP AN EYE ON THERE...AN ISOLATED FUNNEL CLOUD OR LANDSPOUT MAY BE POSSIBLE IF LAPSE RATES BECOME STEEP ENOUGH IN THE AFTERNOON HOURS. OTHERWISE...THE OLD LOW WILL PULL EAST SATURDAY NIGHT AND SUNDAY LEAVING THE REGION WITH COOLER AIR FOR THE FIRST PART OF JUNE. THIS WILL KEEP THE AREA IN THE 60S FOR HIGHS ON SUNDAY WITH MID 40S NORTH AND LOWER 50S SOUTH FOR LOWS ON MONDAY MORNING. AS THE HIGH MOVES EAST...HIGHS WILL RESPOND INTO THE LOWER 70S FOR MONDAY. MONDAY NIGHT WARM AIR ADVECTION AND MID LEVEL MOISTURE BEGIN TO INCREASE AGAIN...RESULTING IN LATE NIGHT/EARLY MORNING ELEVATED CONVECTION. TUESDAY LOOKS ACTIVE AS A STRONGER WAVE ROTATES NORTHEAST INTO THE STATE. THIS WILL RESULT IN MORE WIDESPREAD THUNDERSTORMS WITH RAINFALL AMOUNTS POSSIBLY APPROACHING ONE INCH IN SOME PLACES. THIS WILL CERTAINLY KEEP SOIL MOISTURE HIGH...AND ALSO RESULT IN RENEWED RIVER RISES. THE SYSTEM WILL GRADUALLY EXIT THE REGION BY THURSDAY. THE LARGER SCALE FLOW PATTERN REMAINS GENERALLY WESTERLY AT MID TO HIGH LEVELS. THIS PROMOTES LEE SIDE TROUGHING AND WITH A CONTINUED SUB TROPICAL HIGH ANCHORED OFF THE EAST COAST A WETTER THAN NORMAL PATTERN IS LIKELY TO CONTINUE OVER THE NEXT 7 TO 10 DAYS. ANOTHER INTERESTING WRINKLE IS A TROPICAL DISTURBANCE IN THE GULF OF MEXICO BY NEXT THUR/FRIDAY WHICH MAY EVENTUALLY BE PULLED NORTH TOWARD THE MID MISSISSIPPI RIVER VALLEY. HIGH TEMPERATURES OVER THE NEXT WEEK WILL LIKELY REMAIN IN THE 70S ON AVERAGE AND NOT BREAK OUT OF A 65 TO 75 RANGE BY TOO MUCH IF ANY. ANOTHER NOTE WITH OUR CURRENT WET WEATHER WILL BE CLOUD COVER. UNLESS WE HAVE A STRONG HIGH AND STRONG SUBSIDENCE...MOST LATE MORNINGS AND AFTERNOONS ON ANY SUNNY DAY WILL GO SCT TO BKN BY AFTERNOON. && .AVIATION...31/06Z ISSUED AT 1155 PM CDT THU MAY 30 2013 VFR CONDITIONS EXPECTED THROUGHOUT THE TAF PERIOD FOR ALL TAF SITES. HOWEVER...CONVECTION LOOKS TO DEVELOP FRIDAY MORNING AND WILL POSSIBLY AFFECT OTM PAST 15Z FRIDAY. LOW CONFIDENCE WITH TIMING AND WITH MENTION OF MVFR OR LESS CIGS/VIS. HAVE MENTION OF THUNDER FRIDAY. OTHERWISE...DECENT MIXING BEHIND TROUGH THAT IS EXPECTED TO MOVE THROUGH FRIDAY MORNING. VERY SMALL CHANCE DSM WILL SEE SOME RAIN/THUNDER THROUGH 07Z FRIDAY AND SO ONLY HAVE VCTS MENTIONED ATTM. && .HYDROLOGY... ISSUED AT 323 AM CDT FRI MAY 31 2013 A FLASH FLOOD WATCH REMAINS IN EFFECT FOR BUTLER COUNTY AT THIS TIME DUE TO THE SMALL BREACH IN THE LEVEE ALONG THE BEAVER CREEK AT NEW HARTFORD. A WEATHER DISTURBANCE CAUSING AN AREA OF THUNDERSTORMS FROM KANSAS AND MISSOURI WILL ROTATE NORTHEAST TODAY...AFFECTING THE SOUTHEAST HALF OF THE FORECAST AREA LATER THIS MORNING THROUGH THE AFTERNOON HOURS. THE SOUTHEAST MAY SEE UP TO AN INCH OR MORE OF RAIN...BUT CURRENT FLASH FLOOD GUIDANCE HAS INCREASED TO 1.3 TO 1.5 INCHES PER HOUR AND 1.5 TO 2.25 INCHES IN 3 HOURS AT PRESENT. UNLESS THE STORMS BACK BUILD...THE RISK FOR ANY FLASH FLOODING REMAINS LOW TODAY ACROSS OUR FORECAST AREA. RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR NUMEROUS LOCATIONS THROUGHOUT THE HYDROLOGICAL SERVICES AREA FOR THE NEXT 5 TO 6 DAYS. IN THE SHORT TERM... THE OLD H500 LOW WILL CYCLE EAST IN THE NEXT 24 TO 48 HOURS AND THEN DEPART. WITH ONLY LIGHT SHOWERS OR ISOLATED THUNDER EXPECTED... RAINFALL WILL REMAIN LIGHT. FOLLOWING THAT...HIGH PRESSURE WILL KEEP THE REGION RAIN FREE TO MONDAY EVENING. THIS WILL SLOWLY ALLEVIATE THE SOME OF THE WATER ISSUES THOUGH LARGER MAIN STEM RIVER SYSTEMS WILL REMAIN ABOVE FLOOD STAGE THROUGH THE FORECAST PERIOD. ADDTIONAL MODERATE RAINFALL IS LIKELY BEGINNING LATE MONDAY NIGHT THROUGH THURSDAY WHICH WILL NEED TO BE WATCHED. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THIS EVENING FOR BUTLER. && $$ SHORT TERM...BOKSA LONG TERM...REV AVIATION...PODRAZIK HYDROLOGY...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1159 PM CDT THU MAY 30 2013 ...UPDATED AVIATION DISCUSSION... .SHORT TERM.../TONIGHT /... ISSUED AT 350 PM CDT THU MAY 30 2013 MAIN SHORTWAVE LIFTING THROUGH THE BASE OF THE UPPER LEVEL TROUGH RESPONSIBLE FOR AREA OF SHOWERS AND THUNDERSTORMS ACROSS THE FAR SOUTHEASTERN CWA. AS SHORTWAVE CONTINUES TO LIFT NORTHEAST THROUGH THE EASTERN PORTION OF THE STATE...AREA OF SHOWERS/THUNDERSTORMS WILL CONTINUE TO SHOVE EAST OUT OF THE CWA. LOOKING BACK TO THE WEST...HAVE SOME ISOLATED WEAK CELLS DEVELOPING ACROSS CENTRAL NE/KS. THIS ACTIVITY MAY APPROACH THE SOUTHWESTERN/SOUTHERN CWA BY MID EVENING...BUT IS EXPECTED TO BE RELATIVELY WEAK WITH LESS THAN 1000 J/KG CAPE ON NAM/RAP SOUNDINGS. HRRR SEEMS TO BE GRASPING CURRENT RADAR TRENDS CORRECTLY...SO KEPT POPS CLOSE TO THE HRRR OUTPUT. THE WESTERN ACTIVITY IS MOSTLY DIURNALLY DRIVEN...SO EXPECT IT TO DIMINISH TOWARD SUNSET. ANOTHER WAVE OF ENERGY TO ROUND THE BASE OF THE UPPER LEVEL TROUGH TO APPROACH THE STATE LATE TONIGHT...MAY ALLOW FOR SOME SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP TOWARD SUNRISE FRIDAY MORNING. THE DEEP MOISTURE THAT HAS BEEN IN PLACE ACROSS THE STATE OVER THE PAST WEEK...IS BEGINNING TO PUSH EAST WITH THE ADVANCEMENT OF A DRY LINE OVER CENTRAL NE/KS...THEREFORE THE HEAVY RAIN THREAT WILL BE LESSENED WITH ANY ACTIVITY THAT DEVELOPS LATE TONIGHT/EARLY FRIDAY MORNING. .LONG TERM.../FRIDAY THROUGH THURSDAY/... ISSUED AT 350 PM CDT THU MAY 30 2013 AN UPPER LEVEL LOW PRESSURE SYSTEM WILL REMAIN NEARLY STATIONARY OVER THE DAKOTAS AND MINNESOTA FRIDAY AND FRIDAY NIGHT...BEFORE MOVING EASTWARD ACROSS IOWA ON SATURDAY AND AWAY OVER THE GREAT LAKES ON SATURDAY NIGHT. ON FRIDAY MORNING LOW LEVEL FLOW WILL STILL BE FROM THE SOUTH SOUTHWEST AND AN APPROACHING SHORTWAVE MOVING AROUND THE UPPER LOW SHOULD KICK OFF THUNDERSTORMS ACROSS EASTERN KANSAS LATE TONIGHT THAT WILL MOVE ACROSS OUR SOUTHERN AND EASTERN COUNTIES ON FRIDAY. HAVE INCREASED POPS INTO THE 70 TO 80 PERCENT RANGE IN OUR SOUTHEAST TO ACCOUNT FOR THIS...AND SEVERE WEATHER WILL BE POSSIBLE IN THESE AREAS AS WELL. FRIDAY SHOULD BE FAIRLY WARM ESPECIALLY IF SKIES ARE ABLE TO CLEAR ACROSS MUCH OF THE CWA...AND HAVE RAISED FORECAST HIGHS A BIT EVEN INTO THE LOWER 80S IN SOME AREAS. BY FRIDAY EVENING THE DAYTIME STORMS WILL BE EXITING TO THE EAST AHEAD OF A SURFACE TROUGH MOVING ACROSS THE AREA. WINDS BEHIND THIS TROUGH WILL TURN TO WEST AND THEN NORTHWEST WITH COOLER AIR FLOWING INTO THE AREA. IN ADDITION...AS THE UPPER LEVEL LOW PRESSURE TROUGH MOVES ACROSS OUR AREA ON SATURDAY IT WILL BE ACCOMPANIED BY THICK CLOUDS AND LIGHT SHOWERS MAKING FOR A GREY AND DAMP DAY. NO THUNDERSTORMS ARE ANTICIPATED AND ANY RAINFALL AMOUNTS WILL BE LIGHT. COVERAGE IS UNCERTAIN SO HAVE MAINTAINED POPS BELOW 50 PERCENT...BUT THIS MAY NEED TO BE INCREASED LATER IN A CLASSIC HIGH POP/LOW QPF SCENARIO. BY SUNDAY A SURFACE RIDGE WILL BUILD IN MAKING FOR MOSTLY CLEAR AND DRY BUT COOL WEATHER WITH LIGHT NORTH WINDS. FROM SUNDAY NIGHT THROUGH THURSDAY THE 500 MB PATTERN WILL UNDERGO AN EERILY SIMILAR EVOLUTION TO WHAT WE HAVE SEEN OVER THE LAST SEVERAL DAYS...AS ANOTHER UPPER LOW MOVES INTO THE NORTHWESTERN U.S. AND THEN ACROSS THE UPPER MIDWEST. THIS WILL RESULT IN ANOTHER EXTENDED PERIOD OF THUNDERSTORM CHANCES FOR OUR AREA FROM MONDAY NIGHT THROUGH THE END OF THE FORECAST PERIOD. HOWEVER...UNLIKE THE SYSTEM OF THE PAST SEVERAL DAYS...THE 500 MB LOW NEXT WEEK WILL NOT HAVE AS MUCH LATITUDINAL EXTENT AND WILL BE GENERALLY MORE PROGRESSIVE...MITIGATING SOMEWHAT THE POTENTIAL FOR EXTENDED HEAVY RAINFALL. THE DETAILS OF THE RAINFALL FORECAST FOR NEXT WEEK WILL BE IRONED OUT LATER...BUT AT LEAST THERE WILL BE SEVERAL RELATIVELY DRY DAYS THIS WEEKEND TO ALLOW CURRENT FLOOD WATERS TO SUBSIDE...AND RAINFALL AMOUNTS NEXT WEEK SHOULD BE CONSIDERABLY LIGHTER IN MOST AREAS WITH THE PRIMARY CHANCES LIMITED TO THE MONDAY NIGHT...TUESDAY...AND TUESDAY NIGHT PERIODS. && .AVIATION...31/06Z ISSUED AT 1155 PM CDT THU MAY 30 2013 VFR CONDITIONS EXPECTED THROUGHOUT THE TAF PERIOD FOR ALL TAF SITES. HOWEVER...CONVECTION LOOKS TO DEVELOP FRIDAY MORNING AND WILL POSSIBLY AFFECT OTM PAST 15Z FRIDAY. LOW CONFIDENCE WITH TIMING AND WITH MENTION OF MVFR OR LESS CIGS/VIS. HAVE MENTION OF THUNDER FRIDAY. OTHERWISE...DECENT MIXING BEHIND TROUGH THAT IS EXPECTED TO MOVE THROUGH FRIDAY MORNING. VERY SMALL CHANCE DSM WILL SEE SOME RAIN/THUNDER THROUGH 07Z FRIDAY AND SO ONLY HAVE VCTS MENTIONED ATTM. && .DMX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR BUTLER. && $$ SHORT TERM...BEERENDS LONG TERM...LEE AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
207 PM MDT FRI MAY 31 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 152 PM MDT FRI MAY 31 2013 EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW LARGE SCALE TROUGH STILL IN PLACE ACROSS NORTHERN PLAINS WITH CLOSED CENTER OVER THE EASTERN DAKOTAS. A SERIES OF WEAK VORTICITY MAXIMA ARE ROTATING AROUND THE WESTERN EXTENT OF THE UPPER LOW PRODUCING MID-HIGH CLOUDS ACROSS THE PLAINS. OVER THE SOUTHERN PART OF OUR CWA STEEP LAPSE RATES ALONG A BAROCLINIC ZONE HAS LED TO DEVELOPMENT OF HIGH BASED SHOWERS/VIRGA. WITH BASES GENERALLY AROUND 12KFT AND A DEEP DRY LAYER BELOW THIS...IT IS UNLIKELY MUCH MORE THAN A FEW SPRINKLES WILL REACH THE SURFACE WITH THIS ACTIVITY. RED FLAG CONDITIONS AND GUSTY WINDS SHOULD CONTINUE THROUGH THE EARLY EVENING PERIOD ACROSS NW HALF OF THE CWA. LIMITING FACTOR FOR RFW CONTINUES TO BE FUELS...AND WITHOUT FURTHER INFORMATION IN THIS REGARD I DECIDED AGAINST EXPANDING CURRENT WARNING. WINDS HAVE OCCASIONALLY HIT ADVISORY CRITERIA IN THE NW...HOWEVER THESE CONDITIONS HAVE BEEN SPORADIC...SO IVE LEANED AGAINST ISSUANCE OF WIND ADVISORY. TONIGHT A SHORTWAVE TROUGH WILL ROUND THE BASE OF THE LARGE SCALE UPPER LOW WITH A COLD FRONT DROPPING SOUTH OVER OUR CWA (06 TO 09Z). WHILE WINDS MAY DECREASE SOME AFTER SUNSET...THE LULL IN WINDS THIS EVENING WILL BE SHORT LIVED BEFORE NEAR ADVISORY LEVEL WINDS REDEVELOP AFTER MIDNIGHT AND CONTINUE THROUGH THE DAY SATURDAY BEHIND THE FROPA. SOME GUIDANCE IS ALSO SHOWING BETTER MID LEVEL MOISTURE WITH THIS UPPER LEVEL TROUGH ROTATING INTO THE CWA...HOWEVER THE BEST LIFT IS OUTSIDE OUR CWA...AND MODELS NEVER INITIATE SHOWERS OVER OUR CWA WITH DRY LOW LEVELS STILL IN PLACE. OTHER THAN THICKENING CLOUD COVER...I AM NOT EXPECTING ANY PRECIP. OVERNIGHT LOWS TONIGHT WILL DROP TO THE LOW 40S IN EASTERN COLORADO TO THE LOW 50S IN NORTH CENTRAL KANSAS. CONSIDERING THE COOL NATURE OF THE AIR MASS WE WOULD BE LOOKING AT MUCH COLDER TEMPS IF IT WASNT FOR CLOUD COVER AND WINDS OVERNIGHT. HIGHS ON SATURDAY MAY STRUGGLE TO REACH THE UPPER 60S/70F IF CLOUD COVER FAILS TO CLEAR BY THE AFTERNOON AS CURRENTLY ADVERTISED. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 152 PM MDT FRI MAY 31 2013 FOR SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE UPPER LEVEL RIDGE WILL BEGIN TO MOVE OVER THE AREA SATURDAY NIGHT AS A SURFACE HIGH MOVES INTO THE AREA. SUNDAY THE SURFACE HIGH WILL SLIDE EAST. AS IT DOES SO A TIGHT PRESSURE GRADIENT WILL DEVELOP OVER THE AREA FROM WEST TO EAST BEHIND THE EXITING SURFACE HIGH. WINDS WILL BREEZY BUT WILL DECLINE BEFORE SUNSET AS TEMPERATURES COOL. SUNDAY EVENING AS THE UPPER LEVEL RIDGE AXIS MOVES EAST OF THE AREA A SHORT WAVE TROUGH WILL MOVE ACROSS THE AREA. POINT SOUNDINGS SHOW A VERY SMALL AMOUNT OF ELEVATED INSTABILITY OVER THE SOUTHWEST PART OF THE AREA AS THE SHORT WAVE MOVES THROUGH. AT THIS TIME WILL KEEP THE FORECAST DRY DUE TO LOW CONFIDENCE THAT ANY STORMS WILL DEVELOP GIVEN THE ELEVATED CAPE IS LESS THAN 200 J/KG...AND THE DEEP DRY LAYER EXTENDING UP TO 600MB OR SO WHICH WILL CAUSE ANY LIGHT RAIN THAT MAY DEVELOP TO EVAPORATE. MONDAY THROUGH FRIDAY AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE NORTHERN PLAINS. MODELS HAVE SHIFTED THE TRACK OF THE TROUGH SLIGHTLY NORTH...BUT OVERALL THIS SEEMS TO HAVE LITTLE EFFECT ON PRECIP. CHANCES FOR THE PERIOD. NUMEROUS SHORT WAVE TROUGHS THAT EXTEND FROM THE MAIN FEATURE MOVE OVER THE AREA TROUGH THE PERIOD AS THE TROUGH SLOWLY MOVES EAST OVER THE NORTHERN PLAINS. WITH EACH SHORT WAVE TROUGH MOVING THROUGH THE AREA PRECIP. CHANCES WILL RETURN. TEMPERATURES FOR THE PERIOD WILL START OUT 10 DEGREES ABOVE NORMAL MONDAY THEN COOL TO NEAR NORMAL TUESDAY THROUGH FRIDAY AS A COLD FRONT MOVES THROUGH THE AREA SOMETIME ON TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1120 AM MDT FRI MAY 31 2013 VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD AND KMCK. WESTERLY WINDS GUSTING 35-39KT WILL DECREASE SOME AFTER SUNRISE...WITH SUSTAINED WINDS 10-15KT THIS EVENING. WINDS WILL INCREASE LATE TONIGHT (BY 09-10Z) AS A COLD FRONT MOVES ACROSS THE REGION AND CONTINUE THROUGH SATURDAY MORNING. FOR NOW I INCLUDED GUSTS 30-33KT...HOWEVER THERE IS INDICATION THAT WINDS COULD BE STRONGER FOR A BRIEF PERIOD IMMEDIATELY BEHIND THE FRONT. THERE COULD ALSO BE A FEW LIGHT SHOWERS AS THE FRONT MOVES ACROSS THE AREA...HOWEVER WITH DEEP DRY LAYER IN PLACE IM NOT SURE IF THERE WILL BE MUCH MORE THAN VIRGA WITHIN THE VICINITY OF EITHER TERMINAL. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR KSZ013-027. CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ252>254. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JTL AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1207 AM CDT FRI MAY 31 2013 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 343 PM CDT THU MAY 30 2013 WATER VAPOR LOOP SHOWING CONVECTIVE SYSTEM OVER WESTERN MO MOVING SLOWLY EWD AHEAD OF ONE MID-LEVEL TROUGH. HOWEVER...THERE IS A VERY SHORT WAVELENGTH BETWEEN THAT TROUGH AND THE FOLLOWING IMPULSE THAT APPEARS TO BE OVER WRN KS AT MID AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS HAVE FIRED OVER WRN KS AHEAD OF THIS FEATURE AND THEY ARE MOVING EWD. SHORT RANGE MODEL GUIDANCE NOT RESOLVING THE DETAILS OF THIS VERY WELL...HOWEVER THE 17Z HRRR DOES NOW HAVE A LINE OF CONVECTION MOVING INTO CENTRAL KS BY 21Z. IT FORECASTS THIS TO BREAK UP WITH THE REMNANTS MOVING ACROSS NORTHEAST KS DURING THE EVENING...AND THEN ANOTHER SMALL CONVECTIVE SYSTEM MOVES SOUTHEAST OUT OF NEBRASKA INTO NORTHEAST KS LATER TONIGHT. DO NOT HAVE HIGH CONFIDENCE IN THIS SCENARIO...ALTHOUGH SOME TYPE OF SMALL MCS WOULD APPEAR TO BE LIKELY IN CENTRAL/NORTHEAST KS LATER TONIGHT. THIS POSSIBLE SYSTEM WOULD APPEAR TO MOVE THROUGH FAST ENOUGH AS TO NOT CAUSE SIG PROBLEMS WITH HEAVY RAIN/FLOODING. EARLIER CONCERNS ABOUT WARM AIR ADVECTION CAUSING LIFT AND THUNDERSTORM AREA WITH POTENTIALLY HEAVY RAINFALL OVER EC KS TONIGHT ARE LESSENING AS CONVECTIVE BOUNDARY SAGS WAY SOUTH INTO NORTHEAST OKLAHOMA. THUS...HAVE CANCELLED FLASH FLOOD WATCH THAT WAS IN EFFECT FOR THIS AFTERNOON...AND AM NOT PLANNING ON GOING OUT WITH A NEW ONE AT THIS TIME. CONFIDENCE IN THE DETAILS OF PRECIPITATION EVOLUTION TONIGHT IS NOT HIGH. ON FRIDAY...FRONTAL BOUNDARY SHOULD MAKE IT FAR ENOUGH SOUTH BY AFTERNOON THAT THE MAIN CHANCE OF THUNDERSTORM ACTIVITY WOULD BE IN EC KS...MAINLY SOUTHEAST OF THE KANSAS TURNPIKE. LOWS TONIGHT EXPECTED TO BE AROUND 60 OVER NC KS AND IN THE MID 60S EC. HIGHS ON FRIDAY ARE FORECAST TO MAX OUT AROUND 80. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 343 PM CDT THU MAY 30 2013 DETAILS ONLY GET MURKIER FOR FRIDAY EVENING...BUT AT LEAST SOME CHANCE SHOULD EXIST AHEAD OF THE SYNOPTIC BOUNDARY FOR SOUTHERN AND EASTERN LOCATIONS. SUFFICIENT SHEAR AND INSTABILITY WOULD SUPPORT A SEVERE CONCERN THROUGH THIS TIME AS WELL..BUT THE SOUTHEASTWARD SHIFTING UPPER LOW SHOULD PUSH THE EFFECTIVE FRONT SOUTH OF THE AREA BY DAWN. COLD AIR ADVECTION SETS IN FOR SATURDAY ON NORTHWEST BREEZES WITH SOME STRATUS/STRATOCU DEVELOPING BY MID AFTERNOON. WEAKENING WINDS AND CLEARING SKIES SPELL A COOL NIGHT SATURDAY NIGHT. SURFACE RIDGE SETS UP FOR SUNDAY WITH LITTLE IF ANY MODERATION TO HIGHS. GULF MOISTURE DOES NOT GET COMPLETELY SCOURED OUT...AND BY LATE MONDAY SOUTH WINDS AHEAD OF AN APPROACHING NORTHERN ROCKIES CYCLONE WILL BRING THUNDERSTORM CHANCES BACK. BEST CHANCES LOOK TO BE TUESDAY INTO TUESDAY NIGHT WITH GOOD MODEL AGREEMENT ON A MID LEVEL WAVE PASSING. TEMPS SHOULD GENERALLY BE NEAR EARLY JUNE NORMALS SAVE ANY DAYTIME MCS ACTIVITY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1132 PM CDT THU MAY 30 2013 THUNDERSTORMS CONTINUE TO DEVELOP ALONG THE I 70 CORRIDOR AND SHOULD PERSIST THROUGH 09Z IN THE TERMINALS BEFORE DECREASING/ENDING FROM WEST TO EAST IN THE 08-11Z TIMEFRAME. EXPECT TEMPS MVFR CIGS AND VSBYS IN THE STRONGER ELEVATED CONVECTIVE CELLS BEFORE DIMINISHING AND ENDING BEFORE SUNRISE. BEYOND 11Z VFR CONDITIONS WILL BE THE RULE...ALTHOUGH A FEW SHOWERS MAY LINGER INITIALLY. SFC WINDS WILL GRADUALLY VEER THROUGH THE DAY...BUT REMAIN FAIRLY LIGHT SOUTHWEST TO WEST. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...60 LONG TERM...65 AVIATION...63
AREA FORECAST DISCUSSION
NWS JACKSON KY
601 PM EDT FRI MAY 31 2013 .UPDATE... ISSUED AT 600 PM EDT FRI MAY 31 2013 BASED ON CURRENT RADAR WENT AHEAD AND INCREASED POPS FOR NORTHWESTERN COUNTIES IN THE AERA...WITH THE POTENTIAL FOR SOME SCATTERED SHOWERS OVER THE NEXT HOUR OR TWO ALONG THE FAR SOUTHWESTERN COUNTIES AS WELL. THAT BEING SAID...LOOKING AT MODEL PARAMETERS...DYNAMICS SEEM TO BE FAIRLY WEAK OVER MUCH OF EASTERN KY...AND HI RES MODEL /HRRR/ PRECIP SHOWS A QUICK DIMINISHING TREND THROUGHOUT THE EVENING. TRIED TO REFLECT THIS IDEA WITHIN THE POPS AND WX...WITH THE BEST CHANCE FOR CONVECTION REMAINING OVER THE NORTHERN COUNTIES THROUGH THE EVENING. BUT WITH VERY LITTLE LIGHTNING SHOWING UP ON RADAR AND WEAK INSTABILITY IN OUR AREA...ONLY SLIGHT CHANCE OF THUNDER WAS WARRANTED. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 320 PM EDT FRI MAY 31 2013 MESOSCALE CONVECTIVE VORTEX WHICH HAD BEEN NEAR MADISONVILLE KY AT 1230 PM HAS PULLED NORTHEAST AND IS NOW NEAR LOUISVILLE. STRONGEST CONVECTION HAS BEEN OCCURRING AHEAD OF THIS FEATURE AND NOW PULLING INTO SOUTHWEST OH. CONVECTION TRAILS SOUTH TO WEST OF LAKE CUMBERLAND ALONG OLD OUTFLOW BOUNDARY. WITH THE MOVEMENT OF THIS CONVECTION NNE IT HAS ONLY BEEN VERY SLOWLY NEARING THE SW PART OF FORECAST AREA. HOWEVER...OUTFLOW FROM THIS COULD STILL SERVE AS TRIGGER FOR CONVECTION OVER THE FAR WEST PART OF FORECAST AREA. THE HRRR HAS BEEN PERSISTENT IN TRYING TO BRING CONVECTION INTO OUR AREA...WITH THE 17Z RUN TRYING TO MOVE CONVECTION INTO THE AREA AFTER 22Z...AND THEN SLOWLY DISSIPATING AS IT MOVES EAST. WITH THE MCV MOVING AWAY AND WITH LOSS OF DAYTIME HEATING DO EXPECT ANY CONVECTION IN OUR AREA TO DECREASE QUICKLY THIS EVENING AND WILL DROP SHOWERS AND THUNDERSTORMS FROM FORECAST AFTER MIDNIGHT. A SHORT WAVE MOVING OUT OF THE SOUTHERN PLAINS SHOULD TRIGGER MORE CONVECTION OVER MO TONIGHT...WITH THE EFFECTS OF THIS REMAINING TO OUR WEST OVERNIGHT INTO SATURDAY MORNING. SATURDAY WILL BRING A CHANCE FOR MORE SHOWERS AND THUNDERSTORMS WITH ANY OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION TO OUR WEST POSSIBLY SERVING AS TRIGGER FOR MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS ON SATURDAY. IT IS STILL POSSIBLE SOME OF THE STORMS SATURDAY AFTERNOON AND EVENING COULD BECOME SEVERE...WITH GREATER INSTABILITY DURING THE AFTERNOON INTO THE EVENING. MODELS HAVE TRENDED TOWARDS A QUICKER SOLUTION WITH CONVECTION AHEAD OF THE COLD FRONT MOVING INTO THE AREA SATURDAY NIGHT. WE HAVE FOLLOWED THIS IDEA WITH LIKELY SHOWER AND THUNDERSTORM PROBABILITIES AREA WIDE FOR SATURDAY NIGHT. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 320 PM EDT FRI MAY 31 2013 A COLD FRONT SHOULD BE ABOUT READY TO ENTER THE FORECAST AREA FROM THE NW AT THE START OF THE PERIOD...WITH SUPPORT FROM AN APPROACHING UPPER TROUGH...AND A RIBBON OF HIGHER DEW POINTS OFF THE GULF ALONG THE FRONT BEING ADVECTED ALONG BY A 30-40 KT LOW LEVEL FLOW JUST OFF THE SURFACE. ALL THIS CONSIDERED...THERE WILL LIKELY BE AN ONGOING CONVECTIVE EVENT...WITH MODELS SHOWING THE GREATEST LIKELIHOOD OF THIS IN THE SE PART OF THE AREA. AS THE FRONT SLOWLY PUSHES INTO AND THROUGH THE FORECAST AREA SUNDAY AND SUNDAY EVENING...THERE COULD ALSO BE ADDITIONAL DEVELOPMENT...WITH THE GREATEST OPPORTUNITY FOR THIS IN THE SE WHERE FROPA WILL OCCUR LAST. THE LAST OF ANY LINGERING PRECIP SHOULD END SUNDAY NIGHT OR EARLY MONDAY AS THE FRONT CONTINUES ON TO OUR SE. HIGH PRESSURE OVER THE MIDWEST WILL SUPPLY NOTICEABLY DRIER AND SOMEWHAT COOLER AIR EARLY IN THE WEEK UNDER WNW FLOW ALOFT. RIDGING ALOFT WILL PASS OVER ON TUESDAY INTO WEDNESDAY...WITH THE SURFACE HIGH SHIFTING EASTWARD. THIS WILL BRING A CONTINUATION OF DRY WEATHER...BUT WITH WARMING ALREADY OCCURRING AND AN EVENTUAL INCREASE IN SURFACE MOISTURE. AFTER THIS...MODEL DIFFERENCES BETWEEN THE GFS AND ECMWF BECOME MORE APPARENT LATE IN THE WEEK. THE ECMWF DEVELOPS AN UPPER RIDGE OVER THE CAROLINAS...BUT THIS FEATURE IS LACKING IN THE OPERATIONAL GFS. ALL MODELS INDICATE AN UPPER LOW HEADING EAST ALONG THE CANADIAN BORDER AND INTO ONTARIO...WITH A SOUTHWARD EXTENDING TROUGH. THE 00Z ECMWF DOES NOT ALLOW AS MUCH OF A SOUTHERN EXTENSION OF THIS TROUGH DUE TO ITS CAROLINA RIDGE. THE RESULT IS THAT THE GFS DEVELOPS CONVECTION OVER THE LOCAL AREA FROM WEDNESDAY ON. MEANWHILE...THE ECMWF SHOWS LIGHT PRECIP ONLY ON THURSDAY AS THE TROUGH SCOOTS BY TO OUR NORTH. THE GEM AND GFS ENSEMBLE MEAN SUPPORT THE OPERATIONAL GFS...AND PREFER TO WEIGHT THE FORECAST TOWARD IT...WITH JUST A BIT OF ECMWF INFLUENCE TO KNOCK THE POPS DOWN SLIGHTLY FROM WHERE THEY WOULD OTHERWISE BE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 121 PM EDT FRI MAY 31 2013 CONVECTION IS CURRENTLY DEVELOPING ACROSS CENTRAL KY AND EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO MOVE INTO THE WESTERN PART OF THE FORECAST AREA BY MID TO LATE AFTERNOON. CURRENT INDICATIONS ARE THAT ANY CONVECTION THAT MOVES INTO OR DEVELOPS OVER EASTERN KY WILL DECREASE QUICKLY EARLY THIS EVENING. THERE IS CONSIDERABLE UNCERTAINTY HOW FAR EAST ANY SHOWERS OR THUNDERSTORMS WILL OCCUR...AND AT THIS TIME WILL NOT MENTION ANY THUNDER IN THE JKL OR LOZ TAF. WILL GO WITH VCTS IN THE SME TAF. OUTSIDE OF ANY SHOWER OR THUNDERSTORMS VFR CONDITIONS WILL PREVAIL FOR THE REMAINDER OF THE DAY. ALSO EXPECT VFR CONDITIONS TO PREVAIL TONIGHT AS WELL. THE EXCEPTION TO THIS WOULD BE ANY AREAS THAT RECEIVE RAIN TODAY WHERE OVERNIGHT FOG WOULD BE POSSIBLE. VFR WILL PREVAIL AGAIN SATURDAY MORNING...WITH SHOWERS AND THUNDERSTORMS AGAIN POSSIBLE SATURDAY AFTERNOON. AN APPROACHING COLD FRONT WILL BRING WIDESPREAD SHOWERS AND THUNDERSTORMS SATURDAY NIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JMW SHORT TERM...SBH LONG TERM...HAL AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
320 PM EDT FRI MAY 31 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 320 PM EDT FRI MAY 31 2013 MESOSCALE CONVECTIVE VORTEX WHICH HAD BEEN NEAR MADISONVILLE KY AT 1230 PM HAS PULLED NORTHEAST AND IS NOW NEAR LOUISVILLE. STRONGEST CONVECTION HAS BEEN OCCURRING AHEAD OF THIS FEATURE AND NOW PULLING INTO SOUTHWEST OH. CONVECTION TRAILS SOUTH TO WEST OF LAKE CUMBERLAND ALONG OLD OUTFLOW BOUNDARY. WITH THE MOVEMENT OF THIS CONVECTION NNE IT HAS ONLY BEEN VERY SLOWLY NEARING THE SW PART OF FORECAST AREA. HOWEVER...OUTFLOW FROM THIS COULD STILL SERVE AS TRIGGER FOR CONVECTION OVER THE FAR WEST PART OF FORECAST AREA. THE HRRR HAS BEEN PERSISTENT IN TRYING TO BRING CONVECTION INTO OUR AREA...WITH THE 17Z RUN TRYING TO MOVE CONVECTION INTO THE AREA AFTER 22Z...AND THEN SLOWLY DISSIPATING AS IT MOVES EAST. WITH THE MCV MOVING AWAY AND WITH LOSS OF DAYTIME HEATING DO EXPECT ANY CONVECTION IN OUR AREA TO DECREASE QUICKLY THIS EVENING AND WILL DROP SHOWERS AND THUNDERSTORMS FROM FORECAST AFTER MIDNIGHT. A SHORT WAVE MOVING OUT OF THE SOUTHERN PLAINS SHOULD TRIGGER MORE CONVECTION OVER MO TONIGHT...WITH THE EFFECTS OF THIS REMAINING TO OUR WEST OVERNIGHT INTO SATURDAY MORNING. SATURDAY WILL BRING A CHANCE FOR MORE SHOWERS AND THUNDERSTORMS WITH ANY OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION TO OUR WEST POSSIBLY SERVING AS TRIGGER FOR MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS ON SATURDAY. IT IS STILL POSSIBLE SOME OF THE STORMS SATURDAY AFTERNOON AND EVENING COULD BECOME SEVERE...WITH GREATER INSTABILITY DURING THE AFTERNOON INTO THE EVENING. MODELS HAVE TRENDED TOWARDS A QUICKER SOLUTION WITH CONVECTION AHEAD OF THE COLD FRONT MOVING INTO THE AREA SATURDAY NIGHT. WE HAVE FOLLOWED THIS IDEA WITH LIKELY SHOWER AND THUNDERSTORM PROBABILITIES AREA WIDE FOR SATURDAY NIGHT. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 320 PM EDT FRI MAY 31 2013 A COLD FRONT SHOULD BE ABOUT READY TO ENTER THE FORECAST AREA FROM THE NW AT THE START OF THE PERIOD...WITH SUPPORT FROM AN APPROACHING UPPER TROUGH...AND A RIBBON OF HIGHER DEW POINTS OFF THE GULF ALONG THE FRONT BEING ADVECTED ALONG BY A 30-40 KT LOW LEVEL FLOW JUST OFF THE SURFACE. ALL THIS CONSIDERED...THERE WILL LIKELY BE AN ONGOING CONVECTIVE EVENT...WITH MODELS SHOWING THE GREATEST LIKELIHOOD OF THIS IN THE SE PART OF THE AREA. AS THE FRONT SLOWLY PUSHES INTO AND THROUGH THE FORECAST AREA SUNDAY AND SUNDAY EVENING...THERE COULD ALSO BE ADDITIONAL DEVELOPMENT...WITH THE GREATEST OPPORTUNITY FOR THIS IN THE SE WHERE FROPA WILL OCCUR LAST. THE LAST OF ANY LINGERING PRECIP SHOULD END SUNDAY NIGHT OR EARLY MONDAY AS THE FRONT CONTINUES ON TO OUR SE. HIGH PRESSURE OVER THE MIDWEST WILL SUPPLY NOTICEABLY DRIER AND SOMEWHAT COOLER AIR EARLY IN THE WEEK UNDER WNW FLOW ALOFT. RIDGING ALOFT WILL PASS OVER ON TUESDAY INTO WEDNESDAY...WITH THE SURFACE HIGH SHIFTING EASTWARD. THIS WILL BRING A CONTINUATION OF DRY WEATHER...BUT WITH WARMING ALREADY OCCURRING AND AN EVENTUAL INCREASE IN SURFACE MOISTURE. AFTER THIS...MODEL DIFFERENCES BETWEEN THE GFS AND ECMWF BECOME MORE APPARENT LATE IN THE WEEK. THE ECMWF DEVELOPS AN UPPER RIDGE OVER THE CAROLINAS...BUT THIS FEATURE IS LACKING IN THE OPERATIONAL GFS. ALL MODELS INDICATE AN UPPER LOW HEADING EAST ALONG THE CANADIAN BORDER AND INTO ONTARIO...WITH A SOUTHWARD EXTENDING TROUGH. THE 00Z ECMWF DOES NOT ALLOW AS MUCH OF A SOUTHERN EXTENSION OF THIS TROUGH DUE TO ITS CAROLINA RIDGE. THE RESULT IS THAT THE GFS DEVELOPS CONVECTION OVER THE LOCAL AREA FROM WEDNESDAY ON. MEANWHILE...THE ECMWF SHOWS LIGHT PRECIP ONLY ON THURSDAY AS THE TROUGH SCOOTS BY TO OUR NORTH. THE GEM AND GFS ENSEMBLE MEAN SUPPORT THE OPERATIONAL GFS...AND PREFER TO WEIGHT THE FORECAST TOWARD IT...WITH JUST A BIT OF ECMWF INFLUENCE TO KNOCK THE POPS DOWN SLIGHTLY FROM WHERE THEY WOULD OTHERWISE BE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 121 PM EDT FRI MAY 31 2013 CONVECTION IS CURRENTLY DEVELOPING ACROSS CENTRAL KY AND EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO MOVE INTO THE WESTERN PART OF THE FORECAST AREA BY MID TO LATE AFTERNOON. CURRENT INDICATIONS ARE THAT ANY CONVECTION THAT MOVES INTO OR DEVELOPS OVER EASTERN KY WILL DECREASE QUICKLY EARLY THIS EVENING. THERE IS CONSIDERABLE UNCERTAINTY HOW FAR EAST ANY SHOWERS OR THUNDERSTORMS WILL OCCUR...AND AT THIS TIME WILL NOT MENTION ANY THUNDER IN THE JKL OR LOZ TAF. WILL GO WITH VCTS IN THE SME TAF. OUTSIDE OF ANY SHOWER OR THUNDERSTORMS VFR CONDITIONS WILL PREVAIL FOR THE REMAINDER OF THE DAY. ALSO EXPECT VFR CONDITIONS TO PREVAIL TONIGHT AS WELL. THE EXCEPTION TO THIS WOULD BE ANY AREAS THAT RECEIVE RAIN TODAY WHERE OVERNIGHT FOG WOULD BE POSSIBLE. VFR WILL PREVAIL AGAIN SATURDAY MORNING...WITH SHOWERS AND THUNDERSTORMS AGAIN POSSIBLE SATURDAY AFTERNOON. AN APPROACHING COLD FRONT WILL BRING WIDESPREAD SHOWERS AND THUNDERSTORMS SATURDAY NIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SBH LONG TERM...HAL AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
121 PM EDT FRI MAY 31 2013 .UPDATE... ISSUED AT 1236 PM EDT FRI MAY 31 2013 MESOSCALE CONVECTIVE VORTEX EVIDENT IN RADAR IMAGERY NEAR MADISONVILLE KY MOVING NE. AHEAD OF THIS A BROKEN LINE OF CONVECTION IS INCREASING FROM LOUISVILLE SOUTHWARD TO THE EAST OF GLASGOW KY AND THEN SOUTH INTO TN. THIS IS ALONG AN OUTFLOW FROM THIS MORNINGS CONVECTION. CURRENT INDICATIONS ARE ADDITIONAL OUTFLOW FROM THIS CONVECTION WILL TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS OVER THE SOUTHWEST PART OF THE FORECAST AREA BY 20Z IF NOT A LITTLE SOONER. WILL CONTINUE WITH FORECAST OF SCATTERED SHOWERS AND THUNDERSTORMS IN THE WESTERN PART OF FORECAST AREA THIS AFTERNOON AND ISOLATED SHOWERS AND THUNDERSTORMS IN THE EAST. NDFD AND ZFP UPDATED. UPDATE ISSUED AT 1024 AM EDT FRI MAY 31 2013 RADAR...SATELLITE AND LIGHTNING OBSERVATIONS ALL INDICATE A WEAKENING TREND WITH CONVECTION OVER WESTERN KY. OUTFLOW FROM THIS MAY TRIGGER CONVECTION OVER CENTRAL KY THIS AFTERNOON WITH A MODERATELY UNSTABLE AIR MASS IN PLACE. THIS CONVECTION COULD THEN MAKE ITS WAY INTO THE FORECAST AREA BY MID TO LATE AFTERNOON. THIS IDEA IS SUPPORTED BY THE 12Z HRRR WHICH BRINGS SHOWERS AND THUNDERSTORMS INTO THE WESTERN PART OF THE FORECAST AREA AROUND 20Z. PRIOR TO THIS CONVECTION MAY BE INHIBITED DUE TO MID LEVEL CAPPING WHICH WAS EVIDENT ON THE 12Z ILN SOUNDING. IN FACT THE SMALL SHOWERS THAT DEVELOPED NORTHWEST OF FLEMING COUNTY AROUND 13Z EXHIBITED A WEAKENING TREND ALMOST IMMEDIATELY AS THEY MOVED NNE INTO OH. THE HRRR DID A GOOD JOB DEPICTING THE DEVELOPMENT OF SCATTERED SHOWERS IN THIS AREA WITH A QUICK DISSIPATION TO THE SHOWERS. HAVE SLOWED THE ONSET OF THUNDERSTORMS CHANCES FOR THIS AFTERNOON...AND LOWERED PROBABILITIES ABOUT 10 PERCENT. WITH THIS IN MIND HAVE ALSO RAISED MAXIMUM TEMPERATURES PRIMARILY IN THE EAST WHERE NEARLY THE ENTIRE DAY SHOULD BE RAIN FREE. HOWEVER AFTERNOON TEMPERATURES WILL BE VERY DEPENDENT ON SUNSHINE...AND THE CLOUD COVER FORECAST IS CHALLENGING AS DEBRIS CLOUD FROM THIS MORNINGS CONVECTION MOVES EAST. UPDATED NDFD AND ZFP. UPDATE ISSUED AT 735 AM EDT FRI MAY 31 2013 UPDATED THE FORECAST TO FINE TUNE THE POPS AND SKY THROUGH THE MORNING HOURS....GENERALLY SLOWING THEM DOWN A TAD. ALSO APPLIED THE LATEST OBS AND TRENDS TO THE T...TD...AND SKY GRIDS. IN ADDITION... GIVEN THE ANTICIPATION OF ORGANIZED CONVECTIVE CLUSTERS AND UPPER SUPPORT IN THE FORM OF THE TROUGH ANGLING THIS WAY ON SATURDAY WILL ADD A BEEFIER MENTION OF THUNDERSTORMS...POSSIBLY SEVERE...TO THE HWO. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. AN HWO UPDATE WILL FOLLOW. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 350 AM EDT FRI MAY 31 2013 07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70 ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE RIVERS AND OTHER BODIES OF WATER. THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING... THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12 AND HRRR FOR DETAILS. SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE AS FRIDAY. AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 300 AM EDT FRI MAY 31 2013 A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT AGREEMENT THROUGH THE END OF NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 121 PM EDT FRI MAY 31 2013 CONVECTION IS CURRENTLY DEVELOPING ACROSS CENTRAL KY AND EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO MOVE INTO THE WESTERN PART OF THE FORECAST AREA BY MID TO LATE AFTERNOON. CURRENT INDICATIONS ARE THAT ANY CONVECTION THAT MOVES INTO OR DEVELOPS OVER EASTERN KY WILL DECREASE QUICKLY EARLY THIS EVENING. THERE IS CONSIDERABLE UNCERTAINTY HOW FAR EAST ANY SHOWERS OR THUNDERSTORMS WILL OCCUR...AND AT THIS TIME WILL NOT MENTION ANY THUNDER IN THE JKL OR LOZ TAF. WILL GO WITH VCTS IN THE SME TAF. OUTSIDE OF ANY SHOWER OR THUNDERSTORMS VFR CONDITIONS WILL PREVAIL FOR THE REMAINDER OF THE DAY. ALSO EXPECT VFR CONDITIONS TO PREVAIL TONIGHT AS WELL. THE EXCEPTION TO THIS WOULD BE ANY AREAS THAT RECEIVE RAIN TODAY WHERE OVERNIGHT FOG WOULD BE POSSIBLE. VFR WILL PREVAIL AGAIN SATURDAY MORNING...WITH SHOWERS AND THUNDERSTORMS AGAIN POSSIBLE SATURDAY AFTERNOON. AN APPROACHING COLD FRONT WILL BRING WIDESPREAD SHOWERS AND THUNDERSTORMS SATURDAY NIGHT. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...GREIF LONG TERM...KAS AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
1237 PM EDT FRI MAY 31 2013 .UPDATE... ISSUED AT 1236 PM EDT FRI MAY 31 2013 MESOSCALE CONVECTIVE VORTEX EVIDENT IN RADAR IMAGERY NEAR MADISONVILLE KY MOVING NE. AHEAD OF THIS A BROKEN LINE OF CONVECTION IS INCREASING FROM LOUISVILLE SOUTHWARD TO THE EAST OF GLASGOW KY AND THEN SOUTH INTO TN. THIS IS ALONG AN OUTFLOW FROM THIS MORNINGS CONVECTION. CURRENT INDICATIONS ARE ADDITIONAL OUTFLOW FROM THIS CONVECTION WILL TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS OVER THE SOUTHWEST PART OF THE FORECAST AREA BY 20Z IF NOT A LITTLE SOONER. WILL CONTINUE WITH FORECAST OF SCATTERED SHOWERS AND THUNDERSTORMS IN THE WESTERN PART OF FORECAST AREA THIS AFTERNOON AND ISOLATED SHOWERS AND THUNDERSTORMS IN THE EAST. NDFD AND ZFP UPDATED. UPDATE ISSUED AT 1024 AM EDT FRI MAY 31 2013 RADAR...SATELLITE AND LIGHTNING OBSERVATIONS ALL INDICATE A WEAKENING TREND WITH CONVECTION OVER WESTERN KY. OUTFLOW FROM THIS MAY TRIGGER CONVECTION OVER CENTRAL KY THIS AFTERNOON WITH A MODERATELY UNSTABLE AIR MASS IN PLACE. THIS CONVECTION COULD THEN MAKE ITS WAY INTO THE FORECAST AREA BY MID TO LATE AFTERNOON. THIS IDEA IS SUPPORTED BY THE 12Z HRRR WHICH BRINGS SHOWERS AND THUNDERSTORMS INTO THE WESTERN PART OF THE FORECAST AREA AROUND 20Z. PRIOR TO THIS CONVECTION MAY BE INHIBITED DUE TO MID LEVEL CAPPING WHICH WAS EVIDENT ON THE 12Z ILN SOUNDING. IN FACT THE SMALL SHOWERS THAT DEVELOPED NORTHWEST OF FLEMING COUNTY AROUND 13Z EXHIBITED A WEAKENING TREND ALMOST IMMEDIATELY AS THEY MOVED NNE INTO OH. THE HRRR DID A GOOD JOB DEPICTING THE DEVELOPMENT OF SCATTERED SHOWERS IN THIS AREA WITH A QUICK DISSIPATION TO THE SHOWERS. HAVE SLOWED THE ONSET OF THUNDERSTORMS CHANCES FOR THIS AFTERNOON...AND LOWERED PROBABILITIES ABOUT 10 PERCENT. WITH THIS IN MIND HAVE ALSO RAISED MAXIMUM TEMPERATURES PRIMARILY IN THE EAST WHERE NEARLY THE ENTIRE DAY SHOULD BE RAIN FREE. HOWEVER AFTERNOON TEMPERATURES WILL BE VERY DEPENDENT ON SUNSHINE...AND THE CLOUD COVER FORECAST IS CHALLENGING AS DEBRIS CLOUD FROM THIS MORNINGS CONVECTION MOVES EAST. UPDATED NDFD AND ZFP. UPDATE ISSUED AT 735 AM EDT FRI MAY 31 2013 UPDATED THE FORECAST TO FINE TUNE THE POPS AND SKY THROUGH THE MORNING HOURS....GENERALLY SLOWING THEM DOWN A TAD. ALSO APPLIED THE LATEST OBS AND TRENDS TO THE T...TD...AND SKY GRIDS. IN ADDITION... GIVEN THE ANTICIPATION OF ORGANIZED CONVECTIVE CLUSTERS AND UPPER SUPPORT IN THE FORM OF THE TROUGH ANGLING THIS WAY ON SATURDAY WILL ADD A BEEFIER MENTION OF THUNDERSTORMS...POSSIBLY SEVERE...TO THE HWO. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. AN HWO UPDATE WILL FOLLOW. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 350 AM EDT FRI MAY 31 2013 07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70 ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE RIVERS AND OTHER BODIES OF WATER. THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING... THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12 AND HRRR FOR DETAILS. SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE AS FRIDAY. AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 300 AM EDT FRI MAY 31 2013 A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT AGREEMENT THROUGH THE END OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 745 AM EDT FRI MAY 31 2013 A COUPLE MID LEVEL SHORTWAVES WILL PASS JUST NORTH OF THE AREA TODAY. THE FIRST OF THESE IS RESPONSIBLE FOR THE AREA OF CONVECTION OVER WESTERN KENTUCKY. THIS AREA IS EXPECTED TO PUSH EAST INTO THE AREA LATE THIS MORNING...BUT QUESTIONS REMAIN WHETHER IT WILL BE DECAYING OR STEADY STATE WHEN IT ENTERS...AIDED BY THE BUILDING INSTABILITY WROUGHT BY DIURNAL HEATING. SINCE THE EXACT TIMING AND LOCATION OF THIS REMNANT OR HEALTHY CONVECTIVE CLUSTER COME MIDDAY IS STILL UNCERTAIN HAVE GONE WITH VCTS. THIS FIRST SURGE OF CONVECTION WILL DIE OUT BY EVENING AND FOLLOWING THAT EXPECT THE CIGS TO SCATTER OUT. THE INPUT OF MORE MOISTURE IN THE ENVIRONMENT WILL INCREASE THE POTENTIAL FOR PATCHY VALLEY FOG LATE TONIGHT. WINDS THROUGHOUT THE PERIOD WILL BE AROUND 10 KTS...OR LESS...AND GENERALLY FROM THE SOUTH. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...GREIF LONG TERM...KAS AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
1025 AM EDT FRI MAY 31 2013 .UPDATE... ISSUED AT 1024 AM EDT FRI MAY 31 2013 RADAR...SATELLITE AND LIGHTNING OBSERVATIONS ALL INDICATE A WEAKENING TREND WITH CONVECTION OVER WESTERN KY. OUTFLOW FROM THIS MAY TRIGGER CONVECTION OVER CENTRAL KY THIS AFTERNOON WITH A MODERATELY UNSTABLE AIR MASS IN PLACE. THIS CONVECTION COULD THEN MAKE ITS WAY INTO THE FORECAST AREA BY MID TO LATE AFTERNOON. THIS IDEA IS SUPPORTED BY THE 12Z HRRR WHICH BRINGS SHOWERS AND THUNDERSTORMS INTO THE WESTERN PART OF THE FORECAST AREA AROUND 20Z. PRIOR TO THIS CONVECTION MAY BE INHIBITED DUE TO MID LEVEL CAPPING WHICH WAS EVIDENT ON THE 12Z ILN SOUNDING. IN FACT THE SMALL SHOWERS THAT DEVELOPED NORTHWEST OF FLEMING COUNTY AROUND 13Z EXHIBITED A WEAKENING TREND ALMOST IMMEDIATELY AS THEY MOVED NNE INTO OH. THE HRRR DID A GOOD JOB DEPICTING THE DEVELOPMENT OF SCATTERED SHOWERS IN THIS AREA WITH A QUICK DISSIPATION TO THE SHOWERS. HAVE SLOWED THE ONSET OF THUNDERSTORMS CHANCES FOR THIS AFTERNOON...AND LOWERED PROBABILITIES ABOUT 10 PERCENT. WITH THIS IN MIND HAVE ALSO RAISED MAXIMUM TEMPERATURES PRIMARILY IN THE EAST WHERE NEARLY THE ENTIRE DAY SHOULD BE RAIN FREE. HOWEVER AFTERNOON TEMPERATURES WILL BE VERY DEPENDENT ON SUNSHINE...AND THE CLOUD COVER FORECAST IS CHALLENGING AS DEBRIS CLOUD FROM THIS MORNINGS CONVECTION MOVES EAST. UPDATED NDFD AND ZFP. UPDATE ISSUED AT 735 AM EDT FRI MAY 31 2013 UPDATED THE FORECAST TO FINE TUNE THE POPS AND SKY THROUGH THE MORNING HOURS....GENERALLY SLOWING THEM DOWN A TAD. ALSO APPLIED THE LATEST OBS AND TRENDS TO THE T...TD...AND SKY GRIDS. IN ADDITION... GIVEN THE ANTICIPATION OF ORGANIZED CONVECTIVE CLUSTERS AND UPPER SUPPORT IN THE FORM OF THE TROUGH ANGLING THIS WAY ON SATURDAY WILL ADD A BEEFIER MENTION OF THUNDERSTORMS...POSSIBLY SEVERE...TO THE HWO. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. AN HWO UPDATE WILL FOLLOW. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 350 AM EDT FRI MAY 31 2013 07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70 ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE RIVERS AND OTHER BODIES OF WATER. THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING... THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12 AND HRRR FOR DETAILS. SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE AS FRIDAY. AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 300 AM EDT FRI MAY 31 2013 A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT AGREEMENT THROUGH THE END OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 745 AM EDT FRI MAY 31 2013 A COUPLE MID LEVEL SHORTWAVES WILL PASS JUST NORTH OF THE AREA TODAY. THE FIRST OF THESE IS RESPONSIBLE FOR THE AREA OF CONVECTION OVER WESTERN KENTUCKY. THIS AREA IS EXPECTED TO PUSH EAST INTO THE AREA LATE THIS MORNING...BUT QUESTIONS REMAIN WHETHER IT WILL BE DECAYING OR STEADY STATE WHEN IT ENTERS...AIDED BY THE BUILDING INSTABILITY WROUGHT BY DIURNAL HEATING. SINCE THE EXACT TIMING AND LOCATION OF THIS REMNANT OR HEALTHY CONVECTIVE CLUSTER COME MIDDAY IS STILL UNCERTAIN HAVE GONE WITH VCTS. THIS FIRST SURGE OF CONVECTION WILL DIE OUT BY EVENING AND FOLLOWING THAT EXPECT THE CIGS TO SCATTER OUT. THE INPUT OF MORE MOISTURE IN THE ENVIRONMENT WILL INCREASE THE POTENTIAL FOR PATCHY VALLEY FOG LATE TONIGHT. WINDS THROUGHOUT THE PERIOD WILL BE AROUND 10 KTS...OR LESS...AND GENERALLY FROM THE SOUTH. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SBH SHORT TERM...GREIF LONG TERM...KAS AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
745 AM EDT FRI MAY 31 2013 .UPDATE... ISSUED AT 735 AM EDT FRI MAY 31 2013 UPDATED THE FORECAST TO FINE TUNE THE POPS AND SKY THROUGH THE MORNING HOURS....GENERALLY SLOWING THEM DOWN A TAD. ALSO APPLIED THE LATEST OBS AND TRENDS TO THE T...TD...AND SKY GRIDS. IN ADDITION... GIVEN THE ANTICIPATION OF ORGANIZED CONVECTIVE CLUSTERS AND UPPER SUPPORT IN THE FORM OF THE TROUGH ANGLING THIS WAY ON SATURDAY WILL ADD A BEEFIER MENTION OF THUNDERSTORMS...POSSIBLY SEVERE...TO THE HWO. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS. AN HWO UPDATE WILL FOLLOW. && .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 350 AM EDT FRI MAY 31 2013 07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70 ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE RIVERS AND OTHER BODIES OF WATER. THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING... THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12 AND HRRR FOR DETAILS. SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE AS FRIDAY. AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 300 AM EDT FRI MAY 31 2013 A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT AGREEMENT THROUGH THE END OF NEXT WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 745 AM EDT FRI MAY 31 2013 A COUPLE MID LEVEL SHORTWAVES WILL PASS JUST NORTH OF THE AREA TODAY. THE FIRST OF THESE IS RESPONSIBLE FOR THE AREA OF CONVECTION OVER WESTERN KENTUCKY. THIS AREA IS EXPECTED TO PUSH EAST INTO THE AREA LATE THIS MORNING...BUT QUESTIONS REMAIN WHETHER IT WILL BE DECAYING OR STEADY STATE WHEN IT ENTERS...AIDED BY THE BUILDING INSTABILITY WROUGHT BY DIURNAL HEATING. SINCE THE EXACT TIMING AND LOCATION OF THIS REMNANT OR HEALTHY CONVECTIVE CLUSTER COME MIDDAY IS STILL UNCERTAIN HAVE GONE WITH VCTS. THIS FIRST SURGE OF CONVECTION WILL DIE OUT BY EVENING AND FOLLOWING THAT EXPECT THE CIGS TO SCATTER OUT. THE INPUT OF MORE MOISTURE IN THE ENVIRONMENT WILL INCREASE THE POTENTIAL FOR PATCHY VALLEY FOG LATE TONIGHT. WINDS THROUGHOUT THE PERIOD WILL BE AROUND 10 KTS...OR LESS...AND GENERALLY FROM THE SOUTH. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GREIF SHORT TERM...GREIF LONG TERM...KAS AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
350 AM EDT FRI MAY 31 2013 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 350 AM EDT FRI MAY 31 2013 07Z SFC ANALYSIS SHOWS A LARGE AREA OF LOW PRESSURE...LOCATED OVER THE NORTHERN PLAINS...STARTING TO AFFECT WESTERN KENTUCKY WHILE THE WESTERN EXTENT OF HIGH PRESSURE OVER THE CAROLINAS IS HOLDING ON OVER THE EAST. THIS HAS KEPT THE SKIES MOSTLY CLEAR THROUGH THE NIGHT...THUS FAR...AND...WHEN COMBINED WITH LIGHT WINDS...ANOTHER DECENT NIGHT OF RADIATIONAL COOLING IN UNDERWAY. AS IS NORMAL FOR THESE SITUATIONS...THE SHELTERED VALLEYS HAVE DECOUPLED AND ARE RUNNING A GOOD 10 DEGREES OR SO BELOW THE MILDER RIDGES WITH SPECIFIC TEMPERATURES VARYING FROM AROUND 60 IN THE DEEPER SPOTS TO AROUND 70 ON THE HILLS...IN THE THERMAL BELT. DEWPOINTS ARE ABOUT THE SAME AS LAST NIGHT WITH READINGS GENERALLY IN THE LOWER 60S. AGAIN...EXPECT SOME PATCHY FOG IN THE DEEPER VALLEYS...BUT PRIMARILY JUST NEAR THE RIVERS AND OTHER BODIES OF WATER. THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SOUTHEAST RIDGING... THAT HAS PROTECTED THE AREA FROM MOST OF THE CONVECTION THESE PAST COUPLE OF DAYS...YIELDING TO THE DEVELOPING DEEP AND BROAD MID LEVEL LOW OVER THE NORTHERN PLAINS. A COUPLE OF LEADING SHORTWAVES WILL MOVE INTO THE OHIO VALLEY TODAY...BRUSHING BY TO THE NORTH OF OUR CWA. FOLLOWING THIS...THE UPPER LOW WILL SLIP INTO THE UPPER MIDWEST AND AS A RESULT DRIVE THE HEIGHTS DOWN THROUGHOUT KENTUCKY DURING THE DAY SATURDAY. WITH THE MODELS SUCH AGREEMENT...HAVE BASICALLY FOLLOWED A GENERAL BLEND AND KEYED IN ON THE HIGHER RESOLUTION NAM12 AND HRRR FOR DETAILS. SENSIBLE WEATHER WILL FEATURE A CHANCE OF SHOWERS AND THUNDERSTORMS...CURRENTLY AFFECTING WESTERN KENTUCKY...MOVING INTO THE WESTERN PORTIONS OF EAST KENTUCKY LATER THIS MORNING AND THEN DRIFTING EAST DURING THE REST OF THE DAY. THE EXTRA CLOUDS AND PCPN AROUND SHOULD BE ENOUGH TO KEEP HIGH TEMPERATURES A BIT COOLER THAN YESTERDAY. THE DAYTIME CONVECTION...FUELED BY SOME UPPER LEVEL HELP...LOW LIS...MODERATE CAPE...AND ABOVE NORMAL PWS...WILL DIE OFF BY EARLY EVENING LEAVING A MUGGY AIR MASS BEHIND FOR THE NIGHT WITH ONLY A SMALL RIDGE TO VALLEY DIFFERENCE EXPECTED...BUT MORE IN THE WAY OF PATCHY FOG. SATURDAY WILL SEE THE APPROACH OF THE SYSTEM/S MAIN COLD FRONT AND THIS SHOULD BE ENOUGH TO KICK OFF ADDITIONAL AIR MASS SHOWERS AND STORMS GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE AS FRIDAY. AGAIN USED THE CONSSHORT FOR TD AND WINDS THROUGH THE FIRST 24 HOURS AS A STARTING POINT...WITH HIGHS A BIT LOWER THAN THURSDAY FOR BOTH TODAY AND SATURDAY...WHILE USING THE CONSALL FOR A STARTING POINT TONIGHT. AS FOR POPS...GENERALLY ENDED UP CLOSER TO THE HIGHER MET NUMBERS THROUGHOUT THE SHORT TERM PORTION OF THE FORECAST. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 300 AM EDT FRI MAY 31 2013 A MID/UPPER LEVEL TROUGH WILL SWING ACROSS KENTUCKY SATURDAY NIGHT INTO SUNDAY NIGHT...PRODUCING A PERIOD OF SHOWERS AND THUNDERSTORMS FOR THE AREA. MODELS ARE ALL IN PRETTY DECENT AGREEMENT SO HAVE INCREASED POPS FROM LATE SATURDAY NIGHT INTO SUNDAY. SEVERE THREAT IS FAIRLY MINIMAL AS CLOUD COVER MAY LIMIT INSTABILITY AND SHEAR IS QUITE WEAK. FRONT WILL DEPART TO THE SOUTH SUNDAY NIGHT...WITH RAIN CHANCES DROPPING SOUTHEASTWARD. A COOLER AND LESS HUMID AIRMASS WILL SETTLE INTO THE AREA FOR THE EARLY PORTION OF NEXT WEEK...ALLOWING FOR VERY PLEASANT CONDITIONS FOR EARLY JUNE. ANOTHER RIDGE OF HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST BY THE MIDDLE TO LATE PORTIONS OF NEXT WEEK WITH RETURN FLOW AGAIN ESTABLISHING ITSELF OVER THE AREA. AS MOISTURE INCREASES BY MIDWEEK...RAIN CHANCES WILL SLOWLY RAMP UP SIMILAR TO THIS PAST WEEK. TEMPERATURES WILL TURN MILDER AS WELL AS THE WEEK GOES ON. MODELS ARE ALL IN DECENT AGREEMENT THROUGH THE END OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 215 AM EDT FRI MAY 31 2013 HIGH PRESSURE ALONG THE EAST COAST WILL SLIDE SLOWLY EAST WHILE A CENTER OF LOW PRESSURE CREEPS EAST THROUGH THE NORTHERN PLAINS OVERNIGHT. A TROUGH OF LOW PRESSURE EXTENDING FROM THE NORTHERN PLAINS LOW WILL SWING THROUGH THE MID MS VALLEY AND INTO THE GREAT LAKES ON FRIDAY. THIS LOW PRESSURE TROUGH WILL BRING AN INCREASE IN CLOUD COVER LATE TONIGHT AND INTO FRIDAY...BUT CEILINGS ACROSS THE REGION WILL LIKELY REMAIN VFR. IT APPEARS THAT THE INITIAL SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE LOW PRESSURE TROUGH WILL BE DECAYING AS THEY MOVE EAST INTO EASTERN KY FRIDAY MORNING...BUT WOULD NOT RULE OUT SOME OF THIS CONVECTION IMPACTING THE TAF SITES BY NOON. THE EXACT TIMING AND LOCATION IS STILL UNCERTAIN...SO JUST WENT WITH VCTS AT THIS TIME. THIS FIRST SURGE WILL DIE OUT BY EVENING AND EXPECT THE CIGS TO SCATTER OUT. WINDS THROUGH THE PERIOD WILL BE AROUND 10 KTS OR LESS...GENERALLY FROM THE SOUTH. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...KAS AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
521 PM EDT FRI MAY 31 2013 .SYNOPSIS... A COLD FRONT WILL DROP SOUTH INTO NORTHERN MAINE TONIGHT. THE FRONT WILL LIFT BACK TO THE NORTH AS A WARM FRONT LATE SATURDAY NIGHT. A STRONG COLD FRONT WILL APPROACH FROM THE WEST LATE IN THE DAY SUNDAY AND VERY SLOWLY CROSS THE REGION SUNDAY NIGHT THROUGH MONDAY NIGHT. && .NEAR TERM /THROUGH SATURDAY/... 515 PM UPDATE: WE UPDATED POPS TO INCREASE TO CATEGORICAL RANGE FOR NRN ME TO ACCOUNT FOR THE LN OF TSTMS MOVG IN FROM QB. ENHANCED WORDING FOR DAMAGING WINDS...HAIL AND HEAVY DOWNPOURS WERE INCLUDED TIL 11 PM...AT WHICH POINT...THE HRRR MODEL INDICATES THAT MOST OF THE STRONG TSTM ELEMENTS WILL HAVE MOVED SE INTO NB. ALSO UPDATED QPF FOR THE 18-24Z AND 00-06Z TM FRAMES TNGT TO INCREASE TO CVR CONVECTIVE RNFL RATES WITH THIS LN. 1-3 HR FLASH FLOOD GUIDANCE IS ONLY ABOUT 1.50 INCHES FOR MOST OF NRN ME...SO WE WILL BE MONITORING FOR POSSIBLE LCLZD FLOODING AS WELL. ORGNL DISC: A VERY WARM AND HUMID AIR MASS WILL REMAIN IN PLACE THROUGH TONIGHT. A COLD FRONT WILL SAG SOUTHWARD OUT OF QUEBEC INTO THE SAINT JOHN VALLEY THIS EVENING AND BRING THE THREAT OF STRONG OR SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND SMALL HAIL. WITH STRONG WINDS ALOFT AND FAST STORM MOTIONS...SOME BOWING LINE SEGMENTS ARE POSSIBLE AS THIS CONVECTION ENTERS THE NORTHERN END OF THE CWA THIS EVENING. DOWNED TREES WERE ALREADY REPORTED WITH A WEAKER THUNDERSTORM IN FORT KENT THIS AFTERNOON. DEEPER STORMS MAY ALLOW FOR UP TO QUARTER SIZE HAIL BRIEFLY. WITH PWATS OVER ONE AND HALF INCH...HEAVY DOWNPOURS ARE EXPECTED. THESE STORMS COULD REACH 40K FT. THE SEVERE WEATHER THREAT SHOULD BE RESTRICTED PRIMARILY TO ZONES ONE AND TWO IN NORTHERN AROOSTOOK WITH STORMS WEAKENING BY THE TIME THEY REACH HOULTON LATER THIS EVENING. ELSEWHERE IN THE FORECAST AREA...AIR MASS THUNDERSTORMS WILL END LATER THIS AFTERNOON AND A WARM AND HUMID NIGHT IS EXPECTED WITH LOWS IN THE UPPER 60S FOR DOWN EAST AND AROUND BANGOR. LOWS WILL BE IN THE LOW 60S TOWARDS THE CROWN OF MAINE. THE COLD FRONT WILL STALL IN NORTHERN MAINE WITH CLOUD COVER AND THUNDERSTORMS PERSISTING WELL INTO THE NIGHT. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... ACTIVE WEATHER IS EXPECTED DURING THE SHORT TERM WITH THE MAIN CONCERNS THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS AND FLASH FLOODING. A FRONTAL BOUNDARY IS EXPECTED TO STRETCH ACROSS THE CENTRAL PORTION OF THE CWA SAT EVENING. THE FRONT SHOULD LIFT BACK TO THE NORTH AS A WARM FRONT SAT NIGHT AND SHOULD BE ACCOMPANIED BY SHOWERS AND EMBEDDED THUNDERSTORMS...ESPECIALLY ACROSS THE NORTHERN HALF OF THE AREA. PRECIPITABLE H20 IS PROGGED TO BE AROUND 1.6-1.8 INCHES WHICH IS NEAR RECORD LEVELS FOR JUNE 1ST. SHOWERS AND THUNDERSTORMS SAT NIGHT WILL HAVE THE POTENTIAL OF PRODUCING HEAVY DOWNPOURS...AND DURING THE EVENING GUSTY WIND AND SMALL HAIL. A STRONG COLD FRONT WILL APPROACH THE WESTERN BORDER OF MAINE LATE IN THE DAY SUNDAY. THE MODELS DIFFER ON THE AMOUNT OF INSTABILITY THAT WILL BE AVAILABLE SUN PM...AND MUCH WILL DEPEND ON CLOUD COVER/PRE-EXISTING SHOWERS THAT COULD LIMIT JUST HOW UNSTABLE IT BECOMES DURING THE AFTERNOON. THE MODELS DO INDICATE ENOUGH CAPE AND SHEAR THAT SEVERE STORMS WILL BE POSSIBLE DURING THE AFTERNOON/EVENING. THE HIGH PWATS ALSO MEAN THAT HEAVY DOWNPOURS AND FLASH FLOODING WILL BE CONCERNS TOO...ESPECIALLY GIVEN HOW SATURATED THE GROUND IS FROM THE RECENT HEAVY RAINS. THE ENHANCED WORDING THAT THE MIDNIGHT CREW HAD IN LOOKS REAL GOOD AND THE ONLY CHANGE WAS TO ADD THE LOCALLY HEAVY RAIN WORDING FOR SUN PM/EVE. THE COLD FRONT IS EXPECTED TO ONLY VERY SLOWLY MOVE ACROSS THE CWA SUN NIGHT AND MON AND MAY ONLY BE ON A HOULTON-BANGOR LINE BY MON EVENING. THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY WILL LIKELY BE ACROSS THE SOUTHEAST OF THE CWA WITH SOME DRYING TO BEGIN TO WORK INTO THE WESTERN ZONES. WILL AGAIN MENTION HEAVY RAIN POSSIBLE ACROSS THE SOUTHEAST HALF OF THE CWA. WILL HOLD OFF ON ANY ENHANCED SEVERE WEATHER LANGUAGE AS IT IS IN DAY THREE. THE SPC DOES HAVE MUCH OF THE AREA IN A SLIGHT RISK FOR DAY 3. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... THE EXTENDED MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH THE EARLY AND MID PORTIONS OF THE EXTENDED. A LOW PRESSURE SYSTEM SE OF JAMES BAY...WITH AN ASSOCIATED FRONTAL SYSTEM EXTENDING SOUTH THROUGH DOWNEAST MAINE...THEN SOUTH ALONG THE ATLANTIC COAST. A BERMUDA HIGH PRESSURE SYSTEM RIDGED INTO THE COAST...A SECOND HIGH PRESSURE SYSTEM BUILDING SE OUT OF WRN CANADA. BY THE START OF THE EXTENDED PERIOD THE NRN PORTIONS OF THE FRONT CONTINUES TO REMAIN UNDER THE UPPER LEVEL RIDGE...THE SRN PORTION HOWEVER WILL BEGIN TO MOVE OUT AS THE UPPER TROUGH MOVES TO THE EAST SIDE OF THE APPALACHIANS. BOTH MODELS INDICATE A SECONDARY LOW DEVELOPING ALONG COAST VA WHICH WILL ASSIST WITH THE EASTWARD MOVEMENT OF THE FRONT. BY WED MRNG THE FRONT WILL BE WELL EAST OF THE AREA...AND HIGHER PRESSURE WILL BUILD INTO MAINE. THE HIGH PRESSURE RIDGE WILL REMAIN IN PLACE THROUGH AT LEAST FRI MRNG. FRI MRNG A NEW LOW PRESSURE SYSTEM WILL BE CENTERED OVER THE GREAT LAKES...WITH ITS SUPPORTING UPPER LOW OVER CENTRAL MANITOBA. THE GFS SHOWS A WARM FRONT EXTENDED EAST INTO WRN MAINE. THE ECMWF FRI MRNG MAINTAINS THE HIGH PRESSURE RIDGE WITH NO APPARENT WARM FRONT ASSOCIATED WITH THE FRONT. BY FRI EVENING THE ECMWF SYSTEM BECOMES A BIT MORE ORGANIZED WITH ITS UPPER LOW MOVING TO SW JAMES BAY. BY SAT MRNG BOTH MODELS MOVE THE SHOWERS ASSOCIATED WITH THE LOW INTO MAINE. STARTED WITH A BASE OF GMOS...OVER LAID A BLEND OF OFFICIAL/ALL MODEL BLEND FOR WNDS/POPS/SKY/MAX/MIN. ADDED 15 PERCENT TO WINDS FOR GUSTS OVER LAND...25 PERCENT TO WINDS OVER COASTAL WATERS. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... NEAR TERM: VFR OUTSIDE OF THUNDERSTORMS LATE THIS AFTERNOON AND EVENING. THUNDERSTORMS COULD BE SEVERE TOWARDS CAR...PQI AND FVE THIS EVENING WITH DAMAGING WINDS AND SMALL HAIL. THE FRONT WILL STALL AND COULD PRODUCE IFR VIS AND CIGS FROM PQI NORTHWARD INTO EARLY SATURDAY MORNING. OTHERWISE...VFR CONDITIONS ARE EXPECTED. SHORT TERM: VFR MUCH OF THE TIME SAT NIGHT THROUGH MONDAY...BUT A PERIOD OF MVFR TO IFR POSSIBLE SAT NIGHT FROM KHUL NORTH IN SHOWERS AND THUNDERSTORMS. ADDITIONAL PERIODS OF MVFR AND BRIEF IFR POSSIBLE IN ANY NEAR CONVECTION SUN PM AND AGAIN MONDAY. STRONG AND ERRATIC WIND GUSTS AND HAIL WILL BE POSSIBLE IN/NEAR THE STRONGEST CONVECTION. && .MARINE... NEAR TERM: FOG IS EXPECTED TO RETURN LATER TONIGHT AND TOMORROW ON THE WATERS. OTHERWISE...STABLE CONDITIONS MEAN LIGHT WINDS AND A SOUTH SWELL AROUND 2 TO 3 FEET. SHORT TERM: A SW WIND WILL PICK UP OUT AHEAD OF A COLD FRONT SUNDAY AND MAY REACH SCA LEVELS BY SUN PM AND CONTINUE INTO MONDAY. THE SEAS WILL LIKELY REACH SCA LEVELS BY SUNDAY AFTERNOON AND CONTINUE INTO MONDAY WITH A SOUTH SWELL AND A COMBINED SEA/SWELL OF 8-10 FEET EXPECTED BY SUNDAY NIGHT. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...VJN SHORT TERM...CB LONG TERM...NORTON AVIATION...VJN/CB MARINE...VJN/CB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1233 PM EDT FRI MAY 31 2013 .SYNOPSIS... A WARM RIDGE OF HIGH PRESSURE WILL BUILD REMAIN OVER MUCH OF THE REGION INTO THE WEEKEND. A COLD FRONT WILL BRIEFLY SLIP SOUTHWARD ACROSS NORTHERN AREAS LATER TONIGHT BEFORE PUSHING BACK TO THE NORTHEAST AS A WARM FRONT LATE SATURDAY AND SATURDAY NIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION SUNDAY NIGHT THROUGH MONDAY. && .NEAR TERM /THROUGH TONIGHT/... 1215PM UPDATE... ADDED DAMAGING WINDS ZONES ONE AND TWO THIS EVENING. BOWING LINE SEGMENTS ARE POSSIBLE. LATEST RUC/HRRR GUIDANCE SHOWING 50 KTS AT H850 COINCIDENT WITH STORMS. SMALL HAIL IS ALSO POSSIBLE BUT WINDS SHOULD BE REGARDED AS THE PRIMARY THREAT. PREVIOUSLY INCREASED HIGHS FOR TODAY AND ADJUSTED LOWS TONIGHT. ALSO ADJUSTED TODAY`S CLOUD COVER BASED ON TRENDS AND LATEST GUIDANCE. 9AM UPDATE... HAVE ADDED ENHANCED WORDING FOR LOCALLY HEAVY RAINFALL AND GUSTY WINDS THIS AFTERNOON AND EVENING...MOSTLY FOR NORTHERN AROOSTOOK COUNTY. AS A FRONTAL BOUNDARY SAGS SOUTHWARD THIS EVENING TOWARDS THE SAINT JOHN VALLEY...THE COMBINATION OF DAYTIME HEATING...DEW POINTS IN THE 60S AND SIGNIFICANT INSTABILITY TO THE TROP WILL PRODUCE HEAVY THUNDERSTORMS. 12Z RAOBS FROM CAR AND MANIWAKI AS WELL AS BUFKIT FORECAST SOUNDINGS SHOW A DEEP DRY LAYER FROM THE SFC TO H800. AS A RESULT...WINDS ARE ASSESSED AS THE MOST SIGNIFICANT THREAT BESIDES HEAVY DOWNPOURS. PWATS ARE OVER AN INCH AND A HALF. THE HRRR SEEMS TO HAVE A REASONABLE HANDLE ON THE SITUATION WITH STRONGER CELLS ENTERING THE SAINT JOHN VALLEY THIS EVENING. 635 AM UPDATE...WHAT`S LEFT OF THE ISOLATED TSTM THAT ENTERED THE WESTERN MAINE BORDER NEAR DAAQUAM EARLIER THIS MORNING HAS BEEN MOVING STEADILY SOUTHEAST AND WILL BE NEAR HOULTON SHORTLY. NOT MUCH LTNG WITH THIS CELL AT THE MOMENT BUT WILL CONTINUE TO MENTION ISOLATED THUNDER THIS MORNING...BUT THE BEST CHANCE FOR THUNDER WILL BE THIS AFTERNOON. JUST SOME MINOR TWEAKS OTHERWISE NO SIGNIFICANT CHANGES. UNSEASONABLY WARM WEATHER CAN BE EXPECTED TODAY AS TEMPERATURES ARE EXPECTED TO SOAR INTO THE LOW TO MID 80S ACROSS MOST OF NORTHERN AND DOWNEAST MAINE TODAY. A COLD FRONT WILL APPROACH NORTHERN MOST MAINE THIS AFTERNOON. THIS BOUNDARY WILL BE THE FOCUS FOR SCATTERED SHOWER AND TSTM DEVELOPMENT...MAINLY THIS AFTERNOON. SB CAPE VALUES ARE FORECASTED TO RANGE FROM 500 TO 1000 J/KG WITH EVEN HIGHER CAPE VALUES ACROSS PORTIONS OF INTERIOR DOWNEAST MAINE WHERE MORE IN THE WAY OF SURFACE HEATING IS EXPECTED. DESPITE THE HIGHER CAPE VALUES THE BEST CHANCE OF ANY ORGANIZED THUNDERSTORM DEVELOPMENT WILL BE ACROSS FAR NORTHERN MAINE AND ESPECIALLY THE SAINT JOHN VALLEY WHERE THE APPROACHING BOUNDARY WILL PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT. ALTHOUGH WE ARE EXPECTING ANY THUNDERSTORMS TO REMAIN BELOW SEVERE LIMITS AT THIS TIME. ACROSS CENTRAL AND DOWNEAST MAINE EXPECT ISOLATED THUNDERSTORMS. EXPECT THE FRONTAL BOUNDARY TO SAG INTO NORTHERN MAINE OVERNIGHT AND THIS WILL RESULT IN A CONTINUED CHANCE FOR SHOWERS AND PERHAPS A FEW THUNDERSTORMS CONTINUING INTO THIS EVENING. PATCHY FOG WILL ALSO BE POSSIBLE. LOWS TONIGHT WILL GENERALLY BE IN THE 60S. NOTE: THE MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION HAS ISSUED AN AIR QUALITY ALERT FOR THE DOWNEAST COAST FOR UNHEALTHY FOR SENSITIVE GROUPS DUE TO OZONE. THIS ALERT IS IN EFFECT FRO 11 AM UNTIL 11 PM TONIGHT. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... NOT MUCH CHANGE FROM PREVIOUS THINKING AS MODELS REMAIN VRY CONSISTENT W/ THEIR GUIDANCE THRU THIS PD... BACK DOOR COLD FRONT STILL EXPECTED TO STALL FROM NW-SE MAINE SAT AM THEN LIFT NEWRD AS A WARM FRONT LATE SAT THRU SAT NGT. WILL KEEP HIGHEST POPS (CHC TO LOW LIKELY POPS) ACROSS THE CENTRAL AND N THRU SAT NGT FOR SHOWERS AND OCNL THUNDER AS VRY WARM AND UNSTABLE AIR W AND SW OF THIS FRONT OVERRUNS THIS BNDRY. THIS FRONT SHOULD ALSO CREATE A RATHER DECENT NE-SW THERMAL GRADIENT ACROSS THE REGION W/ COOLEST TEMPS FAR NERN AREAS WHERE CLD/SHOWERS AND BEING ON THE COOL SIDE OF THE BNDRY SHOULD KEEP MAXES ON SAT IN THE LOWER-MID 70S WHILE OUR FAR SWRN AREAS IN THE WARM AND HUMID AIRMASS COULD SEE TEMPS INTO THE UPPER 80S OR EVEN TO 90 DEPENDING ON CLD CVR. BY LATE SAT NGT/ERLY SUN AM...ALL AREAS BACK INTO THE WARM AND STICKY AIR W/ A STRONG COLD FRONT THEN FCST TO APPROACH OUR FAR WRN/NWRN AREAS LATER SUN AFTN. SFC-BASED CAPES OF 1500-2500 J/KG...MDT SHEAR AHEAD OF A STRONG COLD FRONT SUGGESTS AN ELEVATED THREAT OF STRONG TO PSBLY SEVERE STORMS SPCLY OUR WRN/NWRN AREAS FOR SUN AFTN. WILL CONT ENHANCED WORDING AND CONTD MENTION IN THE HWO. FLASH FLOODING RISKS REMAIN A CONCERN AS WELL W/ THE HVY RAINS AND SATURATED SOIL FROM THIS PAST WEEKEND... && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE STRONG COLD FRONT ADDRESSED IN THE SHORT TERM SECTION ABV IS FCST TO SLOWLY CROSS THE FA SUN NGT THRU MON AND EXIT OUR FAR SERN AREAS BY ERLY TUE AM. THIS SLOW TRANSITION ACROSS THE FCST AREA SUGGESTS AN ELEVATED THREAT FOR CONVECTION ACROSS OUR SERN AREAS MON AFTN AND HAVE CARRIED LIKELY POPS FOR SHOWERS/TSTMS MON AFTN OUR SERN ZNS... OTHERWISE...GRADUALLY COOLER AND DRIER AIR IS FCST TO OVERSPREAD THE AREA THRU THE PD AS COOL CANADIAN HIGH PRES BUILD INTO THE REGION. WILL KEEP MENTION OF SHOWERS ACROSS THE N TUE AFTN AS A COLD UPPER TROF SWINGS EWRD ACROSS THE AREA... && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... NEAR TERM: VFR THIS MORNING WITH SOME LOCAL MVFR IN PATCHY FOG. MAINLY VFR THIS AFTERNOON AND TONIGHT EXCEPT LCL MVFR IN SCATTERED SHOWERS AND TSTMS. SHORT TERM: MVFR TO PSBL IFR CONDS ACROSS THE NRN TAF SITES SAT/SAT NGT IN SHOWERS/OCNL THUNDER ASSOCIATED W/ A FRONTAL BNDRY WHICH WILL EVENTUALLY LIFT NE OF THE AREA BY LATER SAT NGT THEN ANOTHER ROUND OF MVFR TO BRIEF IFR W/ SHOWERS/TSTMS LATER SUN AFTN AS A STRONG COLD FRONT APPROACHES. FOR THE SRN TAF SITES...EXPECT MAINLY VFR CONDS W/ SOME PSBL LATE NGT/ERLY AM FOG SAT NGT. MVFR TO BRIEF IFR CONDS EXPECTED LATE SUN INTO MON AS A STRONG COLD FRONT APPROACHES THEN CROSSES THESE AREAS... && .MARINE... NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS THROUGH TONIGHT. SHORT TERM: WARM RIDGE OF HIGH PRES ACROSS THE WATERS THRU THE PD WILL KEEP RATHER STABLE CONDS IN PLACE INTO SUN. BY LATER SUN...DESPITE THIS STABILITY...A STRONG APPROACHING COLD FRONT MAY ALLOW WND GUSTS TO REACH MARGINAL SCA LEVELS. SEAS MAY ALSO INCREASE TO MARGINAL SCA LEVELS IN PERSISTENT SW FLOW IN ADVANCE OF THIS APPROACHING FRONT BY LATER SUN... && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...DUDA/MCW SHORT TERM...KHW LONG TERM...KHW AVIATION...DUDA/MCW/KHW MARINE...DUDA/MCW/KHW
AREA FORECAST DISCUSSION
NWS CARIBOU ME
926 AM EDT FRI MAY 31 2013 .SYNOPSIS... A WARM RIDGE OF HIGH PRESSURE WILL BUILD REMAIN OVER MUCH OF THE REGION INTO THE WEEKEND. A COLD FRONT WILL BRIEFLY SLIP SOUTHWARD ACROSS NORTHERN AREAS LATER TONIGHT BEFORE PUSHING BACK TO THE NORTHEAST AS A WARM FRONT LATE SATURDAY AND SATURDAY NIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION SUNDAY NIGHT THROUGH MONDAY. && .NEAR TERM /THROUGH TONIGHT/... 9AM UPDATE... HAVE ADDED ENHANCED WORDING FOR LOCALLY HEAVY RAINFALL AND GUSTY WINDS THIS AFTERNOON AND EVENING...MOSTLY FOR NORTHERN AROOSTOOK COUNTY. AS A FRONTAL BOUNDARY SAGS SOUTHWARD THIS EVENING TOWARDS THE SAINT JOHN VALLEY...THE COMBINATION OF DAYTIME HEATING...DEW POINTS IN THE 60S AND SIGNIFICANT INSTABILITY TO THE TROP WILL PRODUCE HEAVY THUNDERSTORMS. 12Z RAOBS FROM CAR AND MANIWAKI AS WELL AS BUFKIT FORECAST SOUNDINGS SHOW A DEEP DRY LAYER FROM THE SFC TO H800. AS A RESULT...WINDS ARE ASSESSED AS THE MOST SIGNIFICANT THREAT BESIDES HEAVY DOWNPOURS. PWATS ARE OVER AN INCH AND A HALF. THE HRRR SEEMS TO HAVE A REASONABLE HANDLE ON THE SITUATION WITH STRONGER CELLS ENTERING THE SAINT JOHN VALLEY THIS EVENING. 635 AM UPDATE...WHAT`S LEFT OF THE ISOLATED TSTM THAT ENTERED THE WESTERN MAINE BORDER NEAR DAAQUAM EARLIER THIS MORNING HAS BEEN MOVING STEADILY SOUTHEAST AND WILL BE NEAR HOULTON SHORTLY. NOT MUCH LTNG WITH THIS CELL AT THE MOMENT BUT WILL CONTINUE TO MENTION ISOLATED THUNDER THIS MORNING...BUT THE BEST CHANCE FOR THUNDER WILL BE THIS AFTERNOON. JUST SOME MINOR TWEAKS OTHERWISE NO SIGNIFICANT CHANGES. UNSEASONABLY WARM WEATHER CAN BE EXPECTED TODAY AS TEMPERATURES ARE EXPECTED TO SOAR INTO THE LOW TO MID 80S ACROSS MOST OF NORTHERN AND DOWNEAST MAINE TODAY. A COLD FRONT WILL APPROACH NORTHERN MOST MAINE THIS AFTERNOON. THIS BOUNDARY WILL BE THE FOCUS FOR SCATTERED SHOWER AND TSTM DEVELOPMENT...MAINLY THIS AFTERNOON. SB CAPE VALUES ARE FORECASTED TO RANGE FROM 500 TO 1000 J/KG WITH EVEN HIGHER CAPE VALUES ACROSS PORTIONS OF INTERIOR DOWNEAST MAINE WHERE MORE IN THE WAY OF SURFACE HEATING IS EXPECTED. DESPITE THE HIGHER CAPE VALUES THE BEST CHANCE OF ANY ORGANIZED THUNDERSTORM DEVELOPMENT WILL BE ACROSS FAR NORTHERN MAINE AND ESPECIALLY THE SAINT JOHN VALLEY WHERE THE APPROACHING BOUNDARY WILL PROVIDE A FOCUS FOR CONVECTIVE DEVELOPMENT. ALTHOUGH WE ARE EXPECTING ANY THUNDERSTORMS TO REMAIN BELOW SEVERE LIMITS AT THIS TIME. ACROSS CENTRAL AND DOWNEAST MAINE EXPECT ISOLATED THUNDERSTORMS. EXPECT THE FRONTAL BOUNDARY TO SAG INTO NORTHERN MAINE OVERNIGHT AND THIS WILL RESULT IN A CONTINUED CHANCE FOR SHOWERS AND PERHAPS A FEW THUNDERSTORMS CONTINUING INTO THIS EVENING. PATCHY FOG WILL ALSO BE POSSIBLE. LOWS TONIGHT WILL GENERALLY BE IN THE 60S. NOTE: THE MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION HAS ISSUED AN AIR QUALITY ALERT FOR THE DOWNEAST COAST FOR UNHEALTHY FOR SENSITIVE GROUPS DUE TO OZONE. THIS ALERT IS IN EFFECT FRO 11 AM UNTIL 11 PM TONIGHT. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... NOT MUCH CHANGE FROM PREVIOUS THINKING AS MODELS REMAIN VRY CONSISTENT W/ THEIR GUIDANCE THRU THIS PD... BACK DOOR COLD FRONT STILL EXPECTED TO STALL FROM NW-SE MAINE SAT AM THEN LIFT NEWRD AS A WARM FRONT LATE SAT THRU SAT NGT. WILL KEEP HIGHEST POPS (CHC TO LOW LIKELY POPS) ACROSS THE CENTRAL AND N THRU SAT NGT FOR SHOWERS AND OCNL THUNDER AS VRY WARM AND UNSTABLE AIR W AND SW OF THIS FRONT OVERRUNS THIS BNDRY. THIS FRONT SHOULD ALSO CREATE A RATHER DECENT NE-SW THERMAL GRADIENT ACROSS THE REGION W/ COOLEST TEMPS FAR NERN AREAS WHERE CLD/SHOWERS AND BEING ON THE COOL SIDE OF THE BNDRY SHOULD KEEP MAXES ON SAT IN THE LOWER-MID 70S WHILE OUR FAR SWRN AREAS IN THE WARM AND HUMID AIRMASS COULD SEE TEMPS INTO THE UPPER 80S OR EVEN TO 90 DEPENDING ON CLD CVR. BY LATE SAT NGT/ERLY SUN AM...ALL AREAS BACK INTO THE WARM AND STICKY AIR W/ A STRONG COLD FRONT THEN FCST TO APPROACH OUR FAR WRN/NWRN AREAS LATER SUN AFTN. SFC-BASED CAPES OF 1500-2500 J/KG...MDT SHEAR AHEAD OF A STRONG COLD FRONT SUGGESTS AN ELEVATED THREAT OF STRONG TO PSBLY SEVERE STORMS SPCLY OUR WRN/NWRN AREAS FOR SUN AFTN. WILL CONT ENHANCED WORDING AND CONTD MENTION IN THE HWO. FLASH FLOODING RISKS REMAIN A CONCERN AS WELL W/ THE HVY RAINS AND SATURATED SOIL FROM THIS PAST WEEKEND... && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE STRONG COLD FRONT ADDRESSED IN THE SHORT TERM SECTION ABV IS FCST TO SLOWLY CROSS THE FA SUN NGT THRU MON AND EXIT OUR FAR SERN AREAS BY ERLY TUE AM. THIS SLOW TRANSITION ACROSS THE FCST AREA SUGGESTS AN ELEVATED THREAT FOR CONVECTION ACROSS OUR SERN AREAS MON AFTN AND HAVE CARRIED LIKELY POPS FOR SHOWERS/TSTMS MON AFTN OUR SERN ZNS... OTHERWISE...GRADUALLY COOLER AND DRIER AIR IS FCST TO OVERSPREAD THE AREA THRU THE PD AS COOL CANADIAN HIGH PRES BUILD INTO THE REGION. WILL KEEP MENTION OF SHOWERS ACROSS THE N TUE AFTN AS A COLD UPPER TROF SWINGS EWRD ACROSS THE AREA... && .AVIATION /13Z FRIDAY THROUGH TUESDAY/... NEAR TERM: VFR THIS MORNING WITH SOME LOCAL MVFR IN PATCHY FOG. MAINLY VFR THIS AFTERNOON AND TONIGHT EXCEPT LCL MVFR IN SCATTERED SHOWERS AND TSTMS. SHORT TERM: MVFR TO PSBL IFR CONDS ACROSS THE NRN TAF SITES SAT/SAT NGT IN SHOWERS/OCNL THUNDER ASSOCIATED W/ A FRONTAL BNDRY WHICH WILL EVENTUALLY LIFT NE OF THE AREA BY LATER SAT NGT THEN ANOTHER ROUND OF MVFR TO BRIEF IFR W/ SHOWERS/TSTMS LATER SUN AFTN AS A STRONG COLD FRONT APPROACHES. FOR THE SRN TAF SITES...EXPECT MAINLY VFR CONDS W/ SOME PSBL LATE NGT/ERLY AM FOG SAT NGT. MVFR TO BRIEF IFR CONDS EXPECTED LATE SUN INTO MON AS A STRONG COLD FRONT APPROACHES THEN CROSSES THESE AREAS... && .MARINE... NEAR TERM: WINDS/SEAS WILL REMAIN BELOW SCA LEVELS THROUGH TONIGHT. SHORT TERM: WARM RIDGE OF HIGH PRES ACROSS THE WATERS THRU THE PD WILL KEEP RATHER STABLE CONDS IN PLACE INTO SUN. BY LATER SUN...DESPITE THIS STABILITY...A STRONG APPROACHING COLD FRONT MAY ALLOW WND GUSTS TO REACH MARGINAL SCA LEVELS. SEAS MAY ALSO INCREASE TO MARGINAL SCA LEVELS IN PERSISTENT SW FLOW IN ADVANCE OF THIS APPROACHING FRONT BY LATER SUN... && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...DUDA/MCW SHORT TERM...KHW LONG TERM...KHW AVIATION...DUDA/MCW/KHW MARINE...DUDA/MCW/KHW
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
214 PM EDT FRI MAY 31 2013 .SYNOPSIS... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT SLOWLY CROSSES THE AREA ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... VERY SIMILAR DAY WXWISE TO THU ON THE WAY FOR TODAY. EXPECTING ANOTHER VERY WARM DAY, AS THE SFC RIDGE AND STRENGTHENING H5 RIDGE ALOFT REMAINS QUASI- STATIONARY WELL OFFSHORE. DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS (SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH, RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL AREAS. CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE U60S TO NR 70. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED OVER THE MTNS. HIGHS SAT IN THE U80S-L90S, THOUGH AGAIN COOLER AT THE BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS. PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH WL NEED TO WATCH GFS, AS IT CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW STRATUS OVER THE I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT LATE. ERY MORNING LOWS SUNDAY MORNING IN THE M-U60S. AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING, THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE FROM THE WEST BY SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY. SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST AND PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES (WEST OF RIC) LATE SUN AFTN. MORE IN THE WAY OF CLOUD COVER WILL BE BALANCED OUT BY STRONG COMPRESSIONAL HEATING AHEAD OF THE FRONT, AGAIN YIELDING HIGHS IN THE U80S TO NR 90. GIVEN DP TEMPS IN THE L-M60S (HIGHEST JUST BEFORE DIURNAL MIXING KICKS IN JUST AFTER 12Z)...HEAT INDEX VALUES XPCTD TO REMAIN WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH DAYS. ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO PUSH ACROSS THE WESTERN THIRD OF THE LOCAL AREA LATE SUNDAY NIGHT/MONDAY MORNING. DUE TO THE LATE NIGHT/ERY MORNING TIMING, INSTABILITY ATTM LOOKS TO BE MARGINAL AT BEST, SO WILL GO WITH ISO T WORDING FOR NOW. STILL, AS PW VALUES SHOOT UPWARDS OF 1.75" AREA-WIDE SUNDAY NIGHT, RAIN CHANCES ARE LOOKING INCREASINGLY FAVORABLE ACROSS THE PIEDMONT AFTER 00Z MON/8PM SUNDAY NIGHT. THUS, WL GO WITH LKLY POP WEST OF I-95 LT SUNDAY NIGHT, WITH CHCS INCREASING FARTHER EAST AFTER MIDNIGHT THRU DAWN MONDAY MORNING. GIVEN THE CONSIDERABLE CLDS/PCPN, WL GO CLOSER TO EURO STATISTICAL GUIDANCE, WHICH IS ABT A CATEGORY ABOVE 00Z/31 MEX NUMBERS. ERY MORNING LOWS MON MORNING RIGHT AROUND 70/LOW 70S. && .LONG TERM /MONDAY THROUGH FRIDAY/... LONG TERM PERIOD BEGINS W/ THE FRONT SLOWLY MOVING ACRS THE AREA MON, WITH SHRAS/TSTMS EXPECTED ACROSS THE AREA. ALTHO WAA IS WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT IN THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE AS THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... HIGH PRESSURE OFF THE COAST CONTINUES TO BRING A STRONG FETCH OF S-SW WINDS TO THE REGION. SATELLITE SHOWS A LARGE FIELD OF FAIR WX CU FROM FL TO VA WITH THE FLOW AROUND THE HIGH. WINDS MIGHT BE A LITTLE GUSTY DURING THE AFTN AND EARLY EVENING 15-20 KT...BUT SHOULD DIMINISH AFTER SUNSET. NO SIGNIFICANT WX EXPECTED OVER THE NEXT 24-36 HOURS BUT THE AMOUNT OF LOW LEVEL MOISTURE MAY DEVELOP INTO SOME STRATUS CIGS DURING THE OVERNIGHT...SO OPTED TO SHOW CIGS OF 010-035 FT OVER TAF SITES AND SOME MVFR VIS WITH PTCHY FOG. ONLY LOW TO MODERATE CONFIDENCE THAT THE CIGS OR VIS WILL BE WIDESPREAD. OUTLOOK...THERE WILL BE A BETTER CHANCE FOR MVFR/IFR FOG OR STRATUS SUNDAY MORNING. ISOLATED THUNDERSTORMS WILL BE PSBL SUNDAY EVENING. THE CHANCES INCREASE MONDAY AHEAD OF AN APPROACHING COLD FRONT. DRY/VFR CONDITIONS RETURN BY TUESDAY. && .MARINE... WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE WEEKEND. CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION. THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO PRODUCE SCA BUT THIS MAY CHANGE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MPR/MAM LONG TERM...MAS AVIATION...JEF MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
709 AM EDT FRI MAY 31 2013 .SYNOPSIS... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT SLOWLY CROSSES THE AREA ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... VERY SIMILAR DAY WXWISE TO THU ON THE WAY FOR TODAY. EXPECTING ANOTHER VERY WARM DAY, AS THE SFC RIDGE AND STRENGTHENING H5 RIDGE ALOFT REMAINS QUASI- STATIONARY WELL OFFSHORE. DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS (SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH, RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL AREAS. CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE U60S TO NR 70. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED OVER THE MTNS. HIGHS SAT IN THE U80S-L90S, THOUGH AGAIN COOLER AT THE BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS. PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH WL NEED TO WATCH GFS, AS IT CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW STRATUS OVER THE I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT LATE. ERY MORNING LOWS SUNDAY MORNING IN THE M-U60S. AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING, THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE FROM THE WEST BY SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY. SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST AND PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES (WEST OF RIC) LATE SUN AFTN. MORE IN THE WAY OF CLOUD COVER WILL BE BALANCED OUT BY STRONG COMPRESSIONAL HEATING AHEAD OF THE FRONT, AGAIN YIELDING HIGHS IN THE U80S TO NR 90. GIVEN DP TEMPS IN THE L-M60S (HIGHEST JUST BEFORE DIURNAL MIXING KICKS IN JUST AFTER 12Z)...HEAT INDEX VALUES XPCTD TO REMAIN WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH DAYS. ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO PUSH ACROSS THE WESTERN THIRD OF THE LOCAL AREA LATE SUNDAY NIGHT/MONDAY MORNING. DUE TO THE LATE NIGHT/ERY MORNING TIMING, INSTABILITY ATTM LOOKS TO BE MARGINAL AT BEST, SO WILL GO WITH ISO T WORDING FOR NOW. STILL, AS PW VALUES SHOOT UPWARDS OF 1.75" AREA-WIDE SUNDAY NIGHT, RAIN CHANCES ARE LOOKING INCREASINGLY FAVORABLE ACROSS THE PIEDMONT AFTER 00Z MON/8PM SUNDAY NIGHT. THUS, WL GO WITH LKLY POP WEST OF I-95 LT SUNDAY NIGHT, WITH CHCS INCREASING FARTHER EAST AFTER MIDNIGHT THRU DAWN MONDAY MORNING. GIVEN THE CONSIDERABLE CLDS/PCPN, WL GO CLOSER TO EURO STATISTICAL GUIDANCE, WHICH IS ABT A CATEGORY ABOVE 00Z/31 MEX NUMBERS. ERY MORNING LOWS MON MORNING RIGHT AROUND 70/LOW 70S. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PERIOD BEGINS W/ THE FRONT SLOWLY MOVING ACRS THE AREA MON, WITH SHRAS/TSTMS EXPECTED ACROSS THE AREA. ALTHO WAA IS WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT IN THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE AS THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED. && .AVIATION /11Z FRIDAY THROUGH TUESDAY/... MAINLY S-SW WINDS ARE EXPECTED TO CONTINUE FOR THE 12Z TAF PERIOD WITH ONE POSSIBLE EXCEPTION. WINDS AT ORF MAY BE INFLUENCED ONCE AGAIN BY A BAY BREEZE AS SYNOPTIC WINDS WILL BE A BIT LIGHTER THAN ON THURSDAY. MODELS ARE NOT CLEAR ON THE DIRECTION AND WENT VRBL AND LIGHT. NO SUBSTANTIAL CLOUDINESS IS INDICATED SO KEPT SKC THROUGH THE PERIOD. SOME LOCATIONS OTHER THAN THE TAF SITES REPORTED PATCHY FOG THIS MORNING. WITH THE COLUMN SLOWLY MOISTENING WITH TIME...FOG DEVELOP SATURDAY MORNING AT SOME OF THE TAF SITES WHERE WINDS DIMINISH SUFFICIENTLY. INCLUDED 4 MILES AT RIC FOR NOW AFT 09Z. WINDS MAY BE TOO STRONG AT THE OTHER FOUR SITES BUT THIS WILL NEED TO MONITORED. CONFIDENCE IS LOW FOR THE MVFR STRATUS THAT MAV MOS HAS FOR ECG. OUTLOOK...THERE WILL BE A BETTER CHANCE FOR MVFR/IFR FOG OR STRATUS SUNDAY MORNING. ISOLATED THUNDERSTORMS WILL BE PSBL SUNDAY EVENING. THE CHANCES INCREASE MONDAY AHEAD OF AN APPROACHING COLD FRONT. DRY/VFR CONDITIONS RETURN BY TUESDAY. && .MARINE... WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE WEEKEND. CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION. THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO PRODUCE SCA BUT THIS MAY CHANGE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MPR/MAM LONG TERM...MAS AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
702 AM EDT FRI MAY 31 2013 .SYNOPSIS... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT SLOWLY CROSSES THE AREA ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... VERY SIMILAR DAY WXWISE TO THU ON THE WAY FOR TODAY. EXPECTING ANOTHER VERY WARM DAY, AS THE SFC RIDGE AND STRENGTHENING H5 RIDGE ALOFT REMAINS QUASI- STATIONARY WELL OFFSHORE. DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS (SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH, RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL AREAS. CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE U60S TO NR 70. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED OVER THE MTNS. HIGHS SAT IN THE U80S-L90S, THOUGH AGAIN COOLER AT THE BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS. PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH WL NEED TO WATCH GFS, AS IT CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW STRATUS OVER THE I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT LATE. ERY MORNING LOWS SUNDAY MORNING IN THE M-U60S. AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING, THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE FROM THE WEST BY SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY. SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST AND PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES (WEST OF RIC) LATE SUN AFTN. MORE IN THE WAY OF CLOUD COVER WILL BE BALANCED OUT BY STRONG COMPRESSIONAL HEATING AHEAD OF THE FRONT, AGAIN YIELDING HIGHS IN THE U80S TO NR 90. GIVEN DP TEMPS IN THE L-M60S (HIGHEST JUST BEFORE DIURNAL MIXING KICKS IN JUST AFTER 12Z)...HEAT INDEX VALUES XPCTD TO REMAIN WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH DAYS. ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO PUSH ACROSS THE WESTERN THIRD OF THE LOCAL AREA LATE SUNDAY NIGHT/MONDAY MORNING. DUE TO THE LATE NIGHT/ERY MORNING TIMING, INSTABILITY ATTM LOOKS TO BE MARGINAL AT BEST, SO WILL GO WITH ISO T WORDING FOR NOW. STILL, AS PW VALUES SHOOT UPWARDS OF 1.75" AREA-WIDE SUNDAY NIGHT, RAIN CHANCES ARE LOOKING INCREASINGLY FAVORABLE ACROSS THE PIEDMONT AFTER 00Z MON/8PM SUNDAY NIGHT. THUS, WL GO WITH LKLY POP WEST OF I-95 LT SUNDAY NIGHT, WITH CHCS INCREASING FARTHER EAST AFTER MIDNIGHT THRU DAWN MONDAY MORNING. GIVEN THE CONSIDERABLE CLDS/PCPN, WL GO CLOSER TO EURO STATISTICAL GUIDANCE, WHICH IS ABT A CATEGORY ABOVE 00Z/31 MEX NUMBERS. ERY MORNING LOWS MON MORNING RIGHT AROUND 70/LOW 70S. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PERIOD BEGINS W/ THE FRONT SLOWLY MOVING ACRS THE AREA MON, WITH SHRAS/TSTMS EXPECTED ACROSS THE AREA. ALTHO WAA IS WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT IN THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE AS THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... MAINLY S-SW WINDS ARE EXPECTED TO CONTINUE FOR THE 12Z TAF PERIOD WITH ONE POSSIBLE EXCEPTION. WINDS AT ORF MAY BE INFLUENCED ONCE AGAIN BY A BAY BREEZE AS SYNOPTIC WINDS WILL BE A BIT LIGHTER THAN ON THURSDAY. MODELS ARE NOT CLEAR ON THE DIRECTION AND WENT VRBL AND LIGHT. NO SUBSTANTIAL CLOUDINESS IS INDICATED SO KEPT SKC THROUGH THE PERIOD. SOME LOCATIONS OTHER THAN THE TAF SITES REPORTED PATCHY FOG. WITH THE COLUMN SLOWLY MOISTENING WITH TIME...FOG MAY BE REPORTED AT SOME OF THE TAF SITES WHERE WINDS DIMINISH SUFFICIENTLY. INCLUDED 4 MILES AT RIC FOR NOW AFT 09Z. WINDS MAY BE TOO STRONG AT THE OTHER FOUR SITES BUT THIS WILL NEED TO MONITORED. CONFIDENCE IS LOW FOR THE MVFR STRATUS THAT MAV MOS HAS FOR ECG. OUTLOOK...THERE WILL BE A BETTER CHANCE FOR MVFR/IFR FOG OR STRATUS SUNDAY MORNING. ISOLATED THUNDERSTORMS WILL BE PSBL SUNDAY EVENING. THE CHANCES INCREASE MONDAY AHEAD OF AN APPROACHING COLD FRONT. DRY/VFR CONDITIONS RETURN BY TUESDAY. && .MARINE... WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE WEEKEND. CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION. THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO PRODUCE SCA BUT THIS MAY CHANGE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MPR/MAM LONG TERM...MAS AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
446 AM EDT FRI MAY 31 2013 .SYNOPSIS... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT SLOWLY CROSSES THE AREA ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... VERY SIMILAR DAY WXWISE TO THU ON THE WAY FOR TODAY. EXPECTING ANOTHER VERY WARM DAY, AS THE SFC RIDGE AND STRENGTHENING H5 RIDGE ALOFT REMAINS QUASI- STATIONARY WELL OFFSHORE. DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS (SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH, RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL AREAS. CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE U60S TO NR 70. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED OVER THE MTNS. HIGHS SAT IN THE U80S-L90S, THOUGH AGAIN COOLER AT THE BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS. PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH WL NEED TO WATCH GFS, AS IT CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW STRATUS OVER THE I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT LATE. ERY MORNING LOWS SUNDAY MORNING IN THE M-U60S. AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING, THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE FROM THE WEST BY SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY. SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST AND PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES (WEST OF RIC) LATE SUN AFTN. MORE IN THE WAY OF CLOUD COVER WILL BE BALANCED OUT BY STRONG COMPRESSIONAL HEATING AHEAD OF THE FRONT, AGAIN YIELDING HIGHS IN THE U80S TO NR 90. GIVEN DP TEMPS IN THE L-M60S (HIGHEST JUST BEFORE DIURNAL MIXING KICKS IN JUST AFTER 12Z)...HEAT INDEX VALUES XPCTD TO REMAIN WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH DAYS. ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO PUSH ACROSS THE WESTERN THIRD OF THE LOCAL AREA LATE SUNDAY NIGHT/MONDAY MORNING. DUE TO THE LATE NIGHT/ERY MORNING TIMING, INSTABILITY ATTM LOOKS TO BE MARGINAL AT BEST, SO WILL GO WITH ISO T WORDING FOR NOW. STILL, AS PW VALUES SHOOT UPWARDS OF 1.75" AREA-WIDE SUNDAY NIGHT, RAIN CHANCES ARE LOOKING INCREASINGLY FAVORABLE ACROSS THE PIEDMONT AFTER 00Z MON/8PM SUNDAY NIGHT. THUS, WL GO WITH LKLY POP WEST OF I-95 LT SUNDAY NIGHT, WITH CHCS INCREASING FARTHER EAST AFTER MIDNIGHT THRU DAWN MONDAY MORNING. GIVEN THE CONSIDERABLE CLDS/PCPN, WL GO CLOSER TO EURO STATISTICAL GUIDANCE, WHICH IS ABT A CATEGORY ABOVE 00Z/31 MEX NUMBERS. ERY MORNING LOWS MON MORNING RIGHT AROUND 70/LOW 70S. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PERIOD BEGINS W/ THE FRONT SLOWLY MOVING ACRS THE AREA MON, WITH SHRAS/TSTMS EXPECTED ACROSS THE AREA. ALTHO WAA IS WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT IN THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE AS THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... MAINLY S-SW WINDS ARE EXPECTED TO CONTINUE FOR THE 06Z TAF PERIOD WITH ONE POSSIBLE EXCEPTION. WINDS AT ORF MAY BE INFLUENCED ONCE AGAIN BY A BAY BREEZE AS SYNOPTIC WINDS WILL BE A BIT LIGHTER THAN ON THURSDAY. MODELS ARE NOT CLEAR ON THE DIRECTION AND WENT VRBL AND LIGHT. NO SUBSTANTIAL CLOUDINESS IS INDICATED SO KEPT SKC THROUGH THE PERIOD. THE TEMPERATURE DEW POINT SPREAD MAY LOWER TO 3 DEGREES OR LESS AT A COUPLE OF THE TAF SITES. THE COMBINATION OF A STEADY S/SW WIND AND DRY CONDITIONS AT THE SURFACE SHOULD PRECLUDE FOG FRIDAY MORNING. OUTLOOK...HIGH PRESSURE REMAINS THE DOMINANT WX FEATURE ACROSS THE REGION WITH DRY/VFR WX CONTINUING THROUGH SATURDAY. ISOLATED THUNDERSTORMS WILL BE PSBL SUNDAY EVENING. THE CHANCES INCREASE MONDAY AHEAD OF AN APPROACHING COLD FRONT. && .MARINE... WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE WEEKEND. CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION. THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO PRODUCE SCA BUT THIS MAY CHANGE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MPR/MAM LONG TERM...MAS AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
349 AM EDT FRI MAY 31 2013 .SYNOPSIS... HIGH PRESSURE REMAINS ANCHORED OFF THE MID ATLANTIC COAST THROUGH SUNDAY. A COLD FRONT WILL BRING INCREASING RAIN CHANCES...AS IT SLOWLY CROSSES THE AREA ON MONDAY. && .NEAR TERM /THROUGH TONIGHT/... VERY SIMILAR DAY WXWISE ON THE WAY TODAY. CONTINUED VERY WARM AS THE SFC RIDGE AND STRENGTHENING H5 RIDGE ALOFT REMAINS QUASI- STATIONARY WELL OFFSHORE. DRY WEATHER CONTINUES TODAY WITH PERSISTENT WARM/STABLE AIR ALOFT AND A LACK OF AVAILABLE TRIGGERS FOR LIFT. HIGH-RES MODELS (SPECIFICALLY THE HRRR AND SPC WRF) AGAIN PICKING UP THE THE POTENTIAL FOR AN ISOLATED SHOWER OR TWO BLOWING UP ON AFTN SEABREEZE OVER THE FAR SOUTHEAST PART OF THE CWA (AND ALSO ALONG THE MASON-DIXON IN ASSN WITH A WEAK, SHEARED OUT SHORTWAVE CROSSING WELL NORTH OF THE AKQ CWA). AS WITH YESTERDAY THOUGH, RAIN CHC ACROSS LOCAL AREA REMAINS TOO SMALL TO INCLUDE POPS IN THE FORECAST. THUS, HV CONTINUED TO CAP RAIN CHANCES AT 10% OR LESS. HIGH TEMPERATURES AWAY FROM THE IMMEDIATE COAST AGAIN GENERALLY ~90/L90S INLAND, LOW TO MID 80S AT IMMEDIATE COASTAL AREAS. CLEAR AND MILD OVERNIGHT...EARLY MORNING LOWS SAT MORNING IN THE U60S TO NR 70. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... GRADUALLY WEAKENING H5 RIDGE OFF THE MID ATLANTIC COAST SHIFTS SLIGHTLY TO THE EAST SATURDAY AND SUNDAY AHEAD OF APPROACHING MID-LVL TROUGH, WHICH PUSHES FROM THE NORTHERN PLAINS TOWARDS THE UPR GRT LAKES ON SUNDAY. HOWEVER, SFC/UPR LEVEL RIDGING OFFSHORE WL REMAIN THE DOMINATE WX FEATURE THRU THE WEEKEND, BRINGING CONTINUED SUMMER-LIKE CONDITIONS. LTL (IF ANY) TRIGGER EXISTS FOR CONVECTION ON SAT, AS AIRMASS REMAINS LARGELY CAPPED. FCST REMAINS DRY AS BEST CHCS FOR ANY CONVECTION WILL AGAIN BE CONFINED OVER THE MTNS. HIGHS SAT IN THE U80S-L90S...AGAIN COOLER AT THE BEACHES DUE TO LCL AFTN SEA BREEZE EFFECTS. PARTLY TO MOSTLY CLEAR SKY FOR MOST OF SAT NIGHT, THOUGH GFS CONTINUES TO KEY IN ON POTENTIAL FOR SOME LOW STRATUS OVER THE I-85 CORRIDOR BACK INTO THE CENTRAL NC PIEDMONT LATE. ERY MORNING LOWS IN THE M-U60S. AFTER ANY LINGERING STRATUS QUICKLY LIFTS/ERODES SUNDAY MORNING, THE DAY STARTS OUT MAINLY SUNNY. HOWEVER, CLOUDS LOOK TO INCREASE FROM THE WEST SUN AFTN AHEAD OF APPROACHING FRONTAL BOUNDARY. SLIGHT CHC TO LOW CHC POPS STILL LOOK GOOD BY MID AFTN SUNDAY AS TSRAS LOOK TO FIRE ALONG PRE-FRONTAL/LEE TROUGHING TO THE WEST AND PUSH E-NE ACROSS OUR WESTERN TIER OF COUNTIES LATE SUN AFTN. MORE CLOUD COVER BALANCED OUT BY STRONG COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL AGAIN YIELD HIGHS IN THE U80S TO NR 90. GIVEN DP TEMPS IN THE L-M60S (HIGHEST JUST BEFORE DIURNAL MIXING KICKS IN JUST AFTER 12Z)...HEAT INDEX VALUES XPCTD TO REMAIN WITHIN A DEGREE OR TWO OF ACTUAL TEMPS BOTH DAYS. ECMWF/GFS IN PRETTY GOOD AGREEMENT REGARDING FROPA/PCPN TIMING FOR SUNDAY NIGHT AND MONDAY. FRONT SLOWLY APPROACHES, AND BEGINS TO PUSH ACROSS THE LOCAL AREA LATE SUNDAY NIGHT/MONDAY MORNING. DUE TO THE LATE NIGHT/ERY MORNING TIMING, INSTABILITY ATTM LOOKS TO BE MARGINAL AT BEST, SO WILL GO WITH ISO T WORDING FOR NOW. STILL, AS PW VALUES SHOOT UPWARDS OF 1.75" AREA-WIDE SUNDAY NIGHT, RAIN CHANCES ARE LOOKING INCREASINGLY FAVORABLE ACROSS THE PIEDMONT AFTER 00Z MON/8PM SUNDAY NIGHT. THUS, WL GO WITH LKLY POP WEST OF I-95 LT SUNDAY NIGHT, WITH CHCS INCREASING FARTHER EAST AFTER MIDNIGHT THRU DAWN MONDAY MORNING. GIVEN THE CONSIDERABLE CLDS/PCPN, WL GO CLOSER TO EURO STATISTICAL GUIDANCE, WHICH IS ABT A CATEGORY ABOVE 00Z/31 MEX NUMBERS. ERY MORNING LOWS MON MORNING RIGHT AROUND 70/LOW 70S. && .LONG TERM /MONDAY THROUGH THURSDAY/... LONG TERM PERIOD STARTS OUT W/ THE FRONT SLOWLY MOVING ACRS THE AREA MON, WITH SHRAS/TSTMS ACROSS THE AREA. ALTHO WAA IS WEAK...DEEP LAYER MOISTURE...MID-LVL S/W ENERGY AND UPR-LVL DIVERGENCE CONTINUE TO WARRANT LIKELY POPS...CONTINUING INTO SE AREAS MON NGT. GIVEN THE RAIN AND CLDS...TEMPS MON WILL MAX OUT IN THE UPR 70S TO MID 80S. THE RAIN WILL END FROM W TO E EARLY TUE AS THE FRONT SLIDES OFFSHORE. SFC HI PRES THEN BLDS IN FROM THE NW...WITH HIGHS ONLY IN THE UPR 70S TO LO 80S ON TUE AND WED. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... MAINLY S-SW WINDS ARE EXPECTED TO CONTINUE FOR THE 06Z TAF PERIOD WITH ONE POSSIBLE EXCEPTION. WINDS AT ORF MAY BE INFLUENCED ONCE AGAIN BY A BAY BREEZE AS SYNOPTIC WINDS WILL BE A BIT LIGHTER THAN ON THURSDAY. MODELS ARE NOT CLEAR ON THE DIRECTION AND WENT VRBL AND LIGHT. NO SUBSTANTIAL CLOUDINESS IS INDICATED SO KEPT SKC THROUGH THE PERIOD. THE TEMPERATURE DEW POINT SPREAD MAY LOWER TO 3 DEGREES OR LESS AT A COUPLE OF THE TAF SITES. THE COMBINATION OF A STEADY S/SW WIND AND DRY CONDITIONS AT THE SURFACE SHOULD PRECLUDE FOG FRIDAY MORNING. OUTLOOK...HIGH PRESSURE REMAINS THE DOMINANT WX FEATURE ACROSS THE REGION WITH DRY/VFR WX CONTINUING THROUGH SATURDAY. ISOLATED THUNDERSTORMS WILL BE PSBL SUNDAY EVENING. THE CHANCES INCREASE MONDAY AHEAD OF AN APPROACHING COLD FRONT. && .MARINE... WINDS WILL CONTINUE TO BE GENERALLY FROM THE SOUTH THROUGH THE WEEKEND. WIND SPEEDS AT ELEVATED SITES ARE RUNNING SEVERAL KNOTS HIGHER THAN THOSE NEAR THE SURFACE OF THE WATER DUE TO POOR MIXING WITH THE COLD WATER. THIS SHOULD CONTINUE TO BE THE CASE THROUGH THE WEEKEND. CONDITIONS SHOULD REMAIN BELOW SCA CRITERIA THROUGH THE DAY SATURDAY. SOUTHERLY WINDS MAY GAIN ENOUGH SOUTHERLY FETCH TO PRODUCE MARGINAL 5 FOOT SEAS OVER THE NORTHERN COASTAL WATERS BY SATURDAY NIGHT. HOWEVER...THE MAIN SCA EVENT SHOULD BEGIN SUNDAY NIGHT OVER THE COASTAL WATERS NORTH OF CAPE CHARLES. ELSEWHERE...CONDITIONS SHOULD BE JUST SHORT OF SCA AS A COLD FRONT APPROACHES THE REGION. THE FRONT MOVES SLOWLY TO THE EAST MONDAY NIGHT AND TUESDAY. PRESENT INDICATIONS ARE THAT THE POST FRONTAL ENVIRONMENT WILL FAIL TO PRODUCE SCA BUT THIS MAY CHANGE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>024. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAM NEAR TERM...MAM SHORT TERM...MPR/MAM LONG TERM...MAS AVIATION...LSA MARINE...LSA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1221 PM CDT FRI MAY 31 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI MAY 31 2013 EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH THE PRESSURE OF THE 1.5PVU SURFACE SHOWED A NARROW RIBBON OF POTENTIAL VORTICITY PROTRUDING DOWN TO THE 450/500MB LEVEL. THIS PV RESERVOIR ORIGINATED UPSTREAM OFF THE BRITISH COLUMBIA COAST...EXTENDED SOUTHEAST ACROSS THE KS/NE BORDER...AND CURLED UP OVER THE UPPER MIDWEST. OVERLAYING THE 300MB WINDS SHOWED AN AREA OF POSITIVE VORTICITY OWING TO THE EASTERLY WINDS OF 30KTS ON THE POLEWARD SIDE OF +100KT WESTERLY JET. AT THE SURFACE A 991 LOW WAS LOCATED BENEATH THE LEADING EDGE OF THE PV GRADIENT ALONG THE SD/ND BORDER...WITH A SURFACE COLD FRONT DRAPED ON THE EASTERN SIDE OF THE MISSOURI RIVER VALLEY. FOR TODAY THE 00Z RUN OF THE HOPWRF AND FEW RUNS OF THE HRRR SHOWS ANOTHER ACTIVE DAY SOUTH AND EAST OF THE CWA WITH SEVERAL THUNDERSTORM COMPLEXES EXPECTED TO DEVELOP AS THE DEEP SHEAR ASSOCIATED WITH THE AFOREMENTIONED UPPER LEVEL JET MOVE ACROSS THE MISSISSIPPI RIVER VALLEY. MEANWHILE IT SHOULD BE MAINLY DRY FOR THE FIRST HALF OF FRIDAY ACROSS THE CWA. IN FACT FORECAST SOUNDINGS VIA THE RAP SUPPORT MOSTLY SUNNY SKIES DURING THE MORNING HOURS. HOWEVER...WITH THE VORT MAX ROTATING OVERHEAD EXPECT INCREASING CLOUDS WITH SHOWERS/THUNDERSTORMS AS THE ATMOSPHERE DESTABILIZES BY MID AFTERNOON...MORE SO THAN THE HIRES MODELS WOULD INDICATE. THE BEST DEEP LAYER SHEAR WILL BE ACROSS EASTERN IOWA AND WISCONSIN...SO SEVERE THREAT IS LOW IN MINNESOTA...BUT COULD SEE SOME STRONGER STORMS IN WEST CENTRAL WISCONSIN. BUFR FORECAST SOUNDINGS SHOW ROUGHLY 1000J/KG OF MLCAPE AND FREEZING LEVELS AROUND 9-10KFT AGL...SO WOULD NOT BE SURPRISED TO GET SOME SMALL HAIL AND GUSTY WINDS WITH A FEW OF THE STRONGER CELLS. THE BEST CHANCE FOR DEEPER CONVECTION WILL BE IN EASTERN MN AND WESTERN WI. ON FRIDAY NIGHT THE INSTABILITY WILL DECREASE GIVING WAY TO LIGHT WINDS AND LOW STRATUS AS THE OCCLUDED CYCLONE SLOWLY WOBBLES EASTWARD. A FEW LIGHT RAIN SHOWERS DEVELOP ACROSS THE WESTERN HALF OF THE CWA AS INDICATED BY THE LOW LEVEL SATURATION SHOWN IN THE BUFR SOUNDINGS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI MAY 31 2013 CLOSED UPPER CIRCULATION OVER THE REGION SATURDAY. IT SHOULD PROVIDE GENERAL CLOUDINESS AND THE THREAT OF SHOWERS MUCH OF THE DAY. AS THE CIRCULATION PIVOTS EAST NORTHEAST AND WEAKENS...MODELS SUGGEST SOME WEAK SURFACE BASED CAPE AND SOME SLIGHTLY NEGATIVE BEST LI`S OVER EASTERN AREAS...INTO THE AFTERNOON. WILL NEED SOME BREAKS IN THE CLOUDS TO GENERATE ANY SIGNIFICANT DESTABILIZATION. OPTED TO MENTION ISOLATED THUNDER OVER THE EAST PORTION OF THE CWA...MAINLY IN THE AFTERNOON. WITH SIGNIFICANT CLOUD COVER AROUND...TEMPERATURES MAY NOT GET OUT OF THE 50S OVER THE WEST AND WILL REMAIN IN THE 60S EAST. THIS INITIAL SYSTEM MOVES EAST...AND BECOMES MORE PROGRESSIVE AS THE NEXT SIGNIFICANT TROUGH MOVES ASHORE OVER THE PACIFIC NORTHWEST LATER SUNDAY. THIS SHOULD PROVIDE A CLEARING TREND...ALONG WITH DRIER CONDITIONS SUNDAY INTO MONDAY. SOME RETURN FLOW...WARM AIR ADVECTION PATTERN DEVELOPS DURING THE DAY MONDAY...MAINLY OVER THE FAR WEST. THE WESTERN CLOSED CIRCULATION MOVES SLOWLY EAST OVER THE REGION...AND APPEARS TO AFFECT THE AREA FOR THE REMAINDER OF THE WEEK. THIS WILL AGAIN PROVIDE A LONG PERIOD OF CLOUDINESS AND THE THREAT OF SHOWERS AND THUNDERSTORMS TO THE CWA. TUESDAY AND WEDNESDAY LOOK TO BE THE WETTEST DAYS...BUT THE SHOWERY WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. THE BELOW NORMAL TEMPERATURE PATTERN WILL ALSO CONTINUE INTO THE FIRST PART OF JUNE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1205 PM CDT FRI MAY 31 2013 SHRA HAVE ALREADY DEVELOPED IN SE MN AHEAD OF A STRONG SHRTWV ACROSS WESTERN IOWA. BEST INSTABILITY AND SHEAR WILL REMAIN EAST OF THE FA...BUT RNH/MSP/EAU DO HAVE THE POTENTIAL OF GETTING STRONGER STORMS AS EARLY AS 1-2 PM. EAU HAS THE BEST POTENTIAL OF SVR WIND GUSTS AND LARGE HAIL BEFORE 1Z/01. ACROSS WESTERN MN...THE UPPER LOW HAS NEARLY STALLED. BUT THIS LOW IS EXPECT TO SLOWLY FILL AND MOVE TO THE E-NE OVER THE NEXT DAY OR SO. IFR/MVFR CIGS WITH SCATTERED SHRA WILL OCCUR NEAR AND UNDER THIS LOW PRESSURE SYSTEM...WITH THE BEST POTENTIAL OF -SHRA OCCURRING DURING THE TYPICAL MID AFTN...TO LATE EVENING HRS AS INSTABILITY WILL BE THE GREATEST. MVFR CIGS THIS AFTN WILL LIKELY RISE TO LOW END VFR IN WESTERN MN...BUT LOWER ONCE AGAIN DURING THE EVENING AS THE LOW TRACKS E-NE ACROSS THE NORTHERN FA. TIMING OF THE INITIAL TSRA DEVELOPMENT ACROSS FAR EASTERN MN/WC WI WILL BE DEPENDENT ON WHEN THE WEAKENING CAP BREAKS. AS PREVIOUSLY STATED...TSRA COULD DEVELOP AS EARLY AS 1-2 PM BASED ON THE LATEST MESOSCALE MODEL RUNS. SFC WINDS WILL BE STRONGEST THRU 21Z...THEN DECREASE AND BECOMING LIGHT AND VARIABLE OVERNIGHT. ONCE THE LOW MOVES TO THE EAST...WINDS WILL SHIFT TO THE SW/W...AND EVENTUALLY NW AND INCREASE IN SPD. KMSP... BEST TIME FRAME FOR TSRA/SHRA WILL OCCUR BETWEEN 19-22Z...WITH ONLY SHRA AFT 22Z. ANY TSRA THAT DUE DEVELOP HAVE THE CAPABILITY OF PRODUCING VERY GUSTY WINDS UP TO 40 KTS...AND SMALL HAIL. WILL MONITOR THE POTENTIAL OF AN AWW IF NEEDED. THIS EVENING WILL BE VFR WITH WINDS DECREASE AND SHIFTING TO THE SW UNDER 6 KTS. BY 12-15Z...WINDS WILL SHIFT TO THE W...AND NW AND INCREASE DURING THE AFTN. -SHRA WILL BE POSSIBLE ANY TIME AFT 15Z/01 AS THE SFC LOW MOVES NORTH OF THE AIRPORT TERMINAL. VFR CIGS WILL LIKELY FALL TO MVFR AS THE LOW MOVES CLOSER TO THE AIRPORT SITE OVERNIGHT. /OUTLOOK FOR KMSP/ SAT EVENING...MVFR WITH -SHRA. WINDS NW AT 10G20KTS. SUN...VFR. WINDS NNW AT 10KTS. MON...VFR WITH -SHRA POSSIBLE LATE. WINDS ESE AT 10KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB LONG TERM...DWE AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
451 AM CDT FRI MAY 31 2013 .UPDATED FOR 12Z AVIATION DISCUSSION... ISSUED AT 441 AM CDT FRI MAY 31 2013 && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI MAY 31 2013 EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH THE PRESSURE OF THE 1.5PVU SURFACE SHOWED A NARROW RIBBON OF POTENTIAL VORTICITY PROTRUDING DOWN TO THE 450/500MB LEVEL. THIS PV RESERVOIR ORIGINATED UPSTREAM OFF THE BRITISH COLUMBIA COAST...EXTENDED SOUTHEAST ACROSS THE KS/NE BORDER...AND CURLED UP OVER THE UPPER MIDWEST. OVERLAYING THE 300MB WINDS SHOWED AN AREA OF POSITIVE VORTICITY OWING TO THE EASTERLY WINDS OF 30KTS ON THE POLEWARD SIDE OF +100KT WESTERLY JET. AT THE SURFACE A 991 LOW WAS LOCATED BENEATH THE LEADING EDGE OF THE PV GRADIENT ALONG THE SD/ND BORDER...WITH A SURFACE COLD FRONT DRAPED ON THE EASTERN SIDE OF THE MISSOURI RIVER VALLEY. FOR TODAY THE 00Z RUN OF THE HOPWRF AND FEW RUNS OF THE HRRR SHOWS ANOTHER ACTIVE DAY SOUTH AND EAST OF THE CWA WITH SEVERAL THUNDERSTORM COMPLEXES EXPECTED TO DEVELOP AS THE DEEP SHEAR ASSOCIATED WITH THE AFOREMENTIONED UPPER LEVEL JET MOVE ACROSS THE MISSISSIPPI RIVER VALLEY. MEANWHILE IT SHOULD BE MAINLY DRY FOR THE FIRST HALF OF FRIDAY ACROSS THE CWA. IN FACT FORECAST SOUNDINGS VIA THE RAP SUPPORT MOSTLY SUNNY SKIES DURING THE MORNING HOURS. HOWEVER...WITH THE VORT MAX ROTATING OVERHEAD EXPECT INCREASING CLOUDS WITH SHOWERS/THUNDERSTORMS AS THE ATMOSPHERE DESTABILIZES BY MID AFTERNOON...MORESO THAN THE HIRES MODELS WOULD INDICATE. THE BEST DEEP LAYER SHEAR WILL BE ACROSS EASTERN IOWA AND WISCONSIN...SO SEVERE THREAT IS LOW IN MINNESOTA...BUT COULD SEE SOME STRONGER STORMS IN WEST CENTRAL WISCONSIN. BUFR FORECAST SOUNDINGS SHOW ROUGHLY 1000J/KG OF MLCAPE AND FREEZING LEVELS AROUND 9-10KFT AGL...SO WOULDNT BE SURPRISED TO GET SOME SMALL HAIL AND GUSTY WINDS WITH A FEW OF THE STRONGER CELLS. THE BEST CHANCE FOR DEEPER CONVECTION WILL BE IN EASTERN MN AND WESTERN WI. ON FRIDAY NIGHT THE INSTABILITY WILL DECREASE GIVING WAY TO LIGHT WINDS AND LOW STRATUS AS THE OCCLUDED CYCLONE SLOWLY WOBBLES EASTWARD. A FEW LIGHT RAIN SHOWERS DEVELOP ACROSS THE WESTERN HALF OF THE CWA AS INDICATED BY THE LOW LEVEL SATURATION SHOWN IN THE BUFR SOUNDINGS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI MAY 31 2013 CLOSED UPPER CIRCULATION OVER THE REGION SATURDAY. IT SHOULD PROVIDE GENERAL CLOUDINESS AND THE THREAT OF SHOWERS MUCH OF THE DAY. AS THE CIRCULATION PIVOTS EAST NORTHEAST AND WEAKENS...MODELS SUGGEST SOME WEAK SURFACE BASED CAPE AND SOME SLIGHTLY NEGATIVE BEST LI`S OVER EASTERN AREAS...INTO THE AFTERNOON. WILL NEED SOME BREAKS IN THE CLOUDS TO GENERATE ANY SIGNIFICANT DESTABILIZATION. OPTED TO MENTION ISOLATED THUNDER OVER THE EAST PORTION OF THE CWA...MAINLY IN THE AFTERNOON. WITH SIGNIFICANT CLOUD COVER AROUND...TEMPERATURES MAY NOT GET OUT OF THE 50S OVER THE WEST AND WILL REMAIN IN THE 60S EAST. THIS INITIAL SYSTEM MOVES EAST...AND BECOMES MORE PROGRESSIVE AS THE NEXT SIGNIFICANT TROUGH MOVES ASHORE OVER THE PACIFIC NORTHWEST LATER SUNDAY. THIS SHOULD PROVIDE A CLEARING TREND...ALONG WITH DRIER CONDITIONS SUNDAY INTO MONDAY. SOME RETURN FLOW...WARM AIR ADVECTION PATTERN DEVELOPS DURING THE DAY MONDAY...MAINLY OVER THE FAR WEST. THE WESTERN CLOSED CIRCULATION MOVES SLOWLY EAST OVER THE REGION...AND APPEARS TO AFFECT THE AREA FOR THE REMAINDER OF THE WEEK. THIS WILL AGAIN PROVIDE A LONG PERIOD OF CLOUDINESS AND THE THREAT OF SHOWERS AND THUNDERSTORMS TO THE CWA. TUESDAY AND WEDNESDAY LOOK TO BE THE WETTEST DAYS...BUT THE SHOWERY WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. THE BELOW NORMAL TEMPERATURE PATTERN WILL ALSO CONTINUE INTO THE FIRST PART OF JUNE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 441 AM CDT FRI MAY 31 2013 MAINLY VFR CONDITIONS THIS MORNING...WITH AFTERNOON SHOWERS AND THUNDERSTORMS DEVELOPING...FOLLOWED BY LOWER CIGS ACROSS THE WEST FRIDAY NIGHT. SURFACE LOW OVER THE DAKOTAS WILL MOVE EASTWARD...WITH MVFR CIGS POSSIBLE AT KAXN THIS MORNING. LATER THIS AFTERNOON CLOUDS WILL INCREASE...WITH SHOWERS POSSIBLE AT KAXN/KSTC/KRWF...AND THUNDERSTORMS AT KMSP/KRNH/KEAU. THESE WILL TAPER OFF OVERNIGHT WHILE MVFR CIGS MOVE IN FROM THE NORTHWEST. KMSP... VFR CONDITIONS THIS MORNING WITH SSW WIND INCREASING. LATER THIS AFTERNOON EXPECT TO HAVE SOME SHOWERS AND THUNDERSTORMS SCATTERED ABOUT. BEST CHANCE WILL BE BETWEEN 22-24Z. THIS WILL BE FOLLOWED BY VFR CONDITIONS. /OUTLOOK FOR KMSP/ SAT...MVFR WITH -SHRA. WINDS NW AT 10G20KTS. SUN...VFR. WINDS NNW AT 10KTS. MON...VFR WITH -SHRA POSSIBLE LATE. WINDS ESE AT 10KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB LONG TERM...DWE AVIATION...JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
330 AM CDT FRI MAY 31 2013 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI MAY 31 2013 EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH THE PRESSURE OF THE 1.5PVU SURFACE SHOWED A NARROW RIBBON OF POTENTIAL VORTICITY PROTRUDING DOWN TO THE 450/500MB LEVEL. THIS PV RESERVOIR ORIGINATED UPSTREAM OFF THE BRITISH COLUMBIA COAST...EXTENDED SOUTHEAST ACROSS THE KS/NE BORDER...AND CURLED UP OVER THE UPPER MIDWEST. OVERLAYING THE 300MB WINDS SHOWED AN AREA OF POSITIVE VORTICITY OWING TO THE EASTERLY WINDS OF 30KTS ON THE POLEWARD SIDE OF +100KT WESTERLY JET. AT THE SURFACE A 991 LOW WAS LOCATED BENEATH THE LEADING EDGE OF THE PV GRADIENT ALONG THE SD/ND BORDER...WITH A SURFACE COLD FRONT DRAPED ON THE EASTERN SIDE OF THE MISSOURI RIVER VALLEY. FOR TODAY THE 00Z RUN OF THE HOPWRF AND FEW RUNS OF THE HRRR SHOWS ANOTHER ACTIVE DAY SOUTH AND EAST OF THE CWA WITH SEVERAL THUNDERSTORM COMPLEXES EXPECTED TO DEVELOP AS THE DEEP SHEAR ASSOCIATED WITH THE AFOREMENTIONED UPPER LEVEL JET MOVE ACROSS THE MISSISSIPPI RIVER VALLEY. MEANWHILE IT SHOULD BE MAINLY DRY FOR THE FIRST HALF OF FRIDAY ACROSS THE CWA. IN FACT FORECAST SOUNDINGS VIA THE RAP SUPPORT MOSTLY SUNNY SKIES DURING THE MORNING HOURS. HOWEVER...WITH THE VORT MAX ROTATING OVERHEAD EXPECT INCREASING CLOUDS WITH SHOWERS/THUNDERSTORMS AS THE ATMOSPHERE DESTABILIZES BY MID AFTERNOON...MORESO THAN THE HIRES MODELS WOULD INDICATE. THE BEST DEEP LAYER SHEAR WILL BE ACROSS EASTERN IOWA AND WISCONSIN...SO SEVERE THREAT IS LOW IN MINNESOTA AND EVEN WEST CENTRAL WISCONSIN. BUFR FORECAST SOUNDINGS SHOW ROUGHLY 1000J/KG OF MLCAPE AND FREEZING LEVELS AROUND 9-10KFT AGL...SO COULD SEE SOME SMALL HAIL AND GUSTY WINDS WITH A FEW OF THE STRONGER CELLS. THE BEST CHANCE FOR DEEPER CONVECTION WILL BE IN EASTERN MN AND WESTERN WI. ON FRIDAY NIGHT THE INSTABILITY WILL DECREASE GIVING WAY TO LIGHT WINDS AND LOW STRATUS AS THE OCCLUDED CYCLONE SLOWLY WOBBLES EASTWARD. A FEW LIGHT RAIN SHOWERS DEVELOP ACROSS THE WESTERN HALF OF THE CWA AS INDICATED BY THE LOW LEVEL SATURATION SHOWN IN THE BUFR SOUNDINGS. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 330 AM CDT FRI MAY 31 2013 CLOSED UPPER CIRCULATION OVER THE REGION SATURDAY. IT SHOULD PROVIDE GENERAL CLOUDINESS AND THE THREAT OF SHOWERS MUCH OF THE DAY. AS THE CIRCULATION PIVOTS EAST NORTHEAST AND WEAKENS...MODELS SUGGEST SOME WEAK SURFACE BASED CAPE AND SOME SLIGHTLY NEGATIVE BEST LI`S OVER EASTERN AREAS...INTO THE AFTERNOON. WILL NEED SOME BREAKS IN THE CLOUDS TO GENERATE ANY SIGNIFICANT DESTABILIZATION. OPTED TO MENTION ISOLATED THUNDER OVER THE EAST PORTION OF THE CWA...MAINLY IN THE AFTERNOON. WITH SIGNIFICANT CLOUD COVER AROUND...TEMPERATURES MAY NOT GET OUT OF THE 50S OVER THE WEST AND WILL REMAIN IN THE 60S EAST. THIS INITIAL SYSTEM MOVES EAST...AND BECOMES MORE PROGRESSIVE AS THE NEXT SIGNIFICANT TROUGH MOVES ASHORE OVER THE PACIFIC NORTHWEST LATER SUNDAY. THIS SHOULD PROVIDE A CLEARING TREND...ALONG WITH DRIER CONDITIONS SUNDAY INTO MONDAY. SOME RETURN FLOW...WARM AIR ADVECTION PATTERN DEVELOPS DURING THE DAY MONDAY...MAINLY OVER THE FAR WEST. THE WESTERN CLOSED CIRCULATION MOVES SLOWLY EAST OVER THE REGION...AND APPEARS TO AFFECT THE AREA FOR THE REMAINDER OF THE WEEK. THIS WILL AGAIN PROVIDE A LONG PERIOD OF CLOUDINESS AND THE THREAT OF SHOWERS AND THUNDERSTORMS TO THE CWA. TUESDAY AND WEDNESDAY LOOK TO BE THE WETTEST DAYS...BUT THE SHOWERY WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. THE BELOW NORMAL TEMPERATURE PATTERN WILL ALSO CONTINUE INTO THE FIRST PART OF JUNE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1110 PM CDT THU MAY 30 2013 MAIN COMPLICATIONS WITH THIS SET ARE TWOFOLD. FIRST...THE ONGOING CONVECTION OVER SW MN...WILL IT HOLD TOGETHER TO REACH THE TERMINALS. SECOND...WILL THERE BE CONVECTION LATE TMRW AFTN/TMRW EVE AT THE TERMINALS. FOR THE SW MN ACTIVITY...THE SHWRS/TSTMS ARE MOVING INTO A REGION OF INCRD INSTABILITY AND AN ENVIRONMENT THAT STILL HAS DEWPOINTS IN THE MID 60S. THE ACTIVITY MAY DIMINISH SOMEWHAT IN STRENGTH...MAINLY LOSING THUNDER...BUT AM MORE THAN MODERATELY CONFIDENT THAT SHWRS WILL REACH ALL TERMINALS OVER THE NEXT FEW HOURS SO HAVE INCLUDED STAGGERED TEMPO GROUPS FOR MVFR VSBY SHWRS. HAVE ALSO INCLUDED MVFR CIGS IN THE PRE-DAWN HRS BEFORE VFR CONDS TAKE HOLD THRU MUCH OF THE DAY. GOING INTO LATE TMRW AFTN...MOST SHORT-TERM MODELS HOLD THE NEXT BATCHES OF CONVECTION OVER IA AND INTO FAR SW WI...WHILE THE BROADER-SCALE MODELS INDICATE CONVECTION MAY OVERSPREAD SRN-CENTRAL MN. HAVE PLAYED THINGS CONSERVATIVELY AND HELD OFF PRECIP MENTION ATTM TO GIVE MORE TIME FOR MODELS TO RESOLVE THE SITUATION AND JUST UTILIZED LOWER-END VFR CIGS. SE WINDS AT THE START GRADUALLY VEER TO S AND SW THRU THIS TAF DURATION...AND AGAIN BECOME GUSTY TMRW AFTN INTO TMRW EVE. KMSP...KEPT CONDS VFR THROUGHOUT THIS SET BUT THERE ARE A FEW TIME PERIODS WHERE MVFR CONDS ARE POSSIBLE. FIRST...CONVECTION OVER SW MN MAY REACH MSP BETWEEN 07Z-10Z. ALTHOUGH THUNDER IS NOT EXPECTED..SOME HEAVIER BURSTS OF RAIN MAY DROP VSBY INTO MVFR RANGE. BEHIND THIS RAIN FOR THE REMAINDER OF THE PRE-DAWN HRS...VFR CIGS ARE CURRENTLY ADVERTISED BUT SEEING CIGS DROP INTO THE UPPER MVFR RANGE WOULD NOT AT ALL BE UNREASONABLE. AM NOT THINKING CIGS DROP BELOW 2 KFT. CLOUDS THEN SCATTER OUT SHORTLY AFTER SUNRISE AND REMAIN VFR THRU THE DAY. LOWER-END VFR CIGS RETURN LATE IN THE DAY THEN THERE IS HIGH UNCERTAINTY REGARDING CONVECTION RETURNING LATE AFTN THRU THE EVE HOURS. HAVE LEFT IT OUT ATTM DUE TO LOW CONFIDENCE SO WILL LET LATER MODEL RUNS AND TAF ISSUANCES RESOLVE THIS ISSUE. /OUTLOOK FOR KMSP/ SAT...MVFR CIGS POSSIBLE. SHRA LIKELY. WINDS WNW 5-10 KTS. SUN...MVFR CIGS POSSIBLE EARLY. WINDS N 5 KTS. MON...VFR. WINDS SE 5 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...LS LONG TERM...DWE AVIATION...JPC
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
600 PM CDT FRI MAY 31 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 1233 PM CDT FRI MAY 31 2013 SEE MESO AFD FOR MORE DETAILS THROUGH TONIGHT. MAIN CONCERN LATE TONIGHT WILL BE FLOODING/HYDRO ISSUES. A STRENGTHENING LOW LEVEL JET WILL IMPINGE ON APPROACHING MESOSCALE SFC BOUNDARY. PROGGED PWATS AROUND 1.75 INCHES WITH CONTINUED LOW LEVEL MOISTURE ADVECTION WITH THE POTENTIAL FOR A FORWARD PROPAGATING MCS WITH HEAVY RAINFALL DEVELOPING ON THE OUTFLOW DOMINATE PORTION OF THE MCS SOMEWHERE OVER THE REGION WHERE STORMS CAN TRAIN ALONG A WSW- ENE ORIENTED OUTFLOW BOUNDARY. FCST GUIDANCE HAS TARGETED THE MO OZARK PLATEAU FOR THIS SCENARIO WITH AN EXCESS OF 3-4 INCHES OF RAIN...BUT CONFIDENCE ON THE PRECISE LOCATION OF THE EXCESSIVE/HEAVY RAIN WILL BE AN UNFOLDING STORM AND MESOSCALE ISSUE. THE COLD FRONT WILL FINALLY MOVE THROUGH THE REGION SATURDAY. MAY HAVE TO WATCH FOR SOME REDEVELOPMENT ALONG THE FRONT AS IT EXITS...BUT WILL TACKLE THAT LATER ON. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 1233 PM CDT FRI MAY 31 2013 SUNDAY AND MONDAY WILL BE QUIET AND COOL WITH HIGH PRESSURE NOSING SOUTH INTO THE AREA. ANOTHER UPPER LOW WILL MOVE INTO THE UPPER PLAINS WITH EMBEDDED SHORTWAVES IN THE W-E UPPER LEVEL FLOW TOWARD THE MID/LATE WEEK PERIOD WITH INCREASING RAIN CHANCES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1233 PM CDT FRI MAY 31 2013 CONVECTION CURRENTLY TO THE NORTH OF THE TAF SITES AT 23Z. WILL GRADUALLY SEE THIS TRANSITION SOUTHEASTWARD TONIGHT...BUT TRANSITION WILL BE A SLOW ONE. HRRR SEEMS TO HANDLE THIS THIS BEST AND HAVE USED AS GUIDANCE ON TAKING PRECIPITATION SOUTH THROUGH THE AREA TONIGHT. EXPECTING VFR CONDITIONS OUTSIDE OF CONVECTION AND MVFR CONDITIONS WITHIN THE CONVECTION. COLD FRONT SHOULD PUSH THROUGH THE AREA ON SATURDAY FROM NORTH TO SOUTH. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR MOZ055>058- 066>071-077>083-088>098-101>106. KS...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR KSZ073-097-101. && $$ SHORT TERM...DSA LONG TERM...DSA AVIATION...DSA
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
411 AM CDT Fri May 31 2013 .SHORT TERM...(Today and Tonight) Issued at 410 AM CDT FRI MAY 31 2013 Convection early this morning will persist through sunrise, with the potential for more storms again this afternoon. Environment across eastern Kansas and northern Missouri remains somewhat stabilized from the the excessive rain the region received Thursday, however a speed max ejecting through the Central Plains early this morning has brought considerable focus back to areas from central Kansas east into west central Missouri. Moisture advection within the speed max has proven more than sufficient to initiate thunderstorms early this morning. Storms early this morning are elevated in nature, thanks to the stable boundary layer, but source region for the speed max is, and will continue to, tap MUCAPE values across southern Kansas and Oklahoma around 3000 J/KG, with effective shear values ranging above 50 knots. This will make storms through the early morning hours rather volatile, with large hail and torrential rain the primary threats. Activity through sunrise will generally range between Highway 50 and Highway 36, as this region will be the focus for continued mass convergence as long as the speed max is moving through. Speed max will be to veer off after sunrise, likely allowing the storms to transit from intense thunderstorms into widespread rain for several hours this morning, therefore the severe thunderstorm watch in effect for parts of our forecast area this morning only runs through 8 AM. Thunderstorm activity from this morning will likely take much of the morning to run its course, bringing more saturating rain to the region. Potential for redevelopment is there for the afternoon hours if this mornings storms dissipate quickly enough to allow for surface destabilization later on. Storm initialization should get a boost this afternoon as a front across eastern Nebraska into central Kansas begins to sweep through northern Missouri as the parent circulation across the Northern Plains begins to shift farther east. However, focus for afternoon convection should set up a little farther east and south, limiting the likely POPs to the southeastern half of the outlook area, from east central Kansas through northeast Missouri. Large hail and torrential rain continue to look like the major threats later this afternoon into this evening. .LONG TERM...(Saturday through Thursday) Issued at 410 AM CDT FRI MAY 31 2013 Looking into the weekend, it finally appears that we will have a small respite from the storms. Parent trough giving us our current round of storms will finally transit far enough east to take the focus off the Plains States. This presents us with a dry forecast after any potential lingering storm activity Saturday morning fades away. Currently, forecast looks dry through Monday, with below normal temperatures --Sunday might not make it out of the 60s--. Unfortunately, our forecast does not remain dry. By Monday night, models are advertising the beginning of another round of rain as yet another trough begins to swing out of the Pacific Northwest into the Northern Plains, interacting with the shortwave ridge that will be in place. Confidence is not high enough to say that next work week will be like this past work week, but the potential looks to be there for more excessive rainfall next week. && .AVIATION...(For the 06Z TAFS through 06Z Friday Night) Issued at 1220 AM CDT FRI MAY 31 2013 Scattered convection forming along a west-east band from central KS into west central MO is likely the start of a convective complex that will evolve overnight as the southerly low level jet over central KS and OK ramps up. The 00z NAM and latest HRRR seem to have the nest handle on the current situation and followed the general theme of increasing convective activity into the terminals as we move into the pre- dawn hours of Friday morning. With increasing confidence on a convective complex forming have lowered ceilings into the MVFR category with MVFR visibilities. Should the expected complex take dead aim on any of the terminals the risk of IFR ceilings/visibilities will increase...and most likely in the 10-13z time period. Should see convection drop off considerably by mid morning with ceiling improving to VFR. Still the potential for late afternoon/early evening re-development of convection but with continued low confidence it will affect the KMCI/KMKC terminals. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...FLASH FLOOD WATCH through this evening FOR KSZ025-057-060- 102>105. MO...FLASH FLOOD WATCH through this evening FOR MOZ001>008-011>017- 020>025-028>033-037>040-043>046-053-054. && $$ SHORT TERM...Cutter LONG TERM...Cutter AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1220 AM CDT Fri May 31 2013 .UPDATE... Issued at 1000 PM CDT THU MAY 30 2013 Adjusted short term forecast for current radar/satellite/model trends. Except for a few isolated cells over far nw MO and east central KS looking quiet for a few more hours. However, already seeing signs on satellite/radar over central KS. The rapid increase of alto-cumulus clouds and elevated returns is signaling the rapid redevelopment of the low level jet. The 00z NAM is noticeably stronger with the h8 winds and this seems reasonable. The 00z NAM, HRRR and RAP all generate rapid convective development on the nose of the low level jet and spread it across east central KS and west central MO during the pre-dawn hours. Heavy rains and near-severe storms are expected between 08z-14z Friday over this region. && .SHORT TERM...(This Evening through Friday) Issued at 325 PM CDT THU MAY 30 2013 Leading edge of storms should move east of the forecast area by 4 or so leaving just the trailing stratiform area of rainfall with embedded convection through the early evening. So through this evening the chances of rain/embedded storms will diminish from west to east. The focus then shifts to tonight for the possibility of convection erupting in eastern Kansas and then spreading into western Missouri. There is a quite a bit of uncertainty with how things may evolve tonight as several short-range models keep things quiet overnight. However, the more reliable HRRR, which has been handling today`s convection very well, has been consistent in developing convection somewhere across northeastern Kansas and moving into west central and northwestern Missouri. This roughly corresponds to an area of strong isentropic lift with a focusing of the LLJ depicted by the GFS. There should be enough instability and shear to lead to storm organization so a few severe storms are possible with large hail the biggest threat with damaging winds possible as well. Will keep the flash flood watch going as is given recent heavy rains across northern Missouri and persistent moderate to heavy rain across the southern portions of the forecast and the uncertainty with where any heavy rain may set up tonight. Some areas within the watch area have good chance of seeing heavy rainfall tonight and some much river flooding ongoing and already saturated soils, it won`t take much more rain to lead to rapid runoff and flash flooding. .LONG TERM...(Friday Night through Thursday) Issued at 325 PM CDT THU MAY 30 2013 Cold front will slide through the forecast area Friday night, pushing the threat for thunderstorms southeast of the area. Elongated area of high pressure will build into much of the Plains over the weekend providing dry conditions and comfortable temperatures. Cold air advection on Saturday and Sunday will keep highs in the upper 60 and lower 70s. Warm air advection on the back side of this area of high pressure will set the stage for an increase in rain chances next week. Initial rain chances will begin early Tuesday when a weak shortwave will eject into the Plains ahead of a deeper wave digging into the Upper Midwest. This system will eventually drop a cold front and associated chances for showers and thunderstorms into the area by mid-week, though there are still considerable model differences with the timing of this activity. && .AVIATION...(For the 06Z TAFS through 06Z Friday Night) Issued at 1220 AM CDT FRI MAY 31 2013 Scattered convection forming along a west-east band from central KS into west central MO is likely the start of a convective complex that will evolve overnight as the southerly low level jet over central KS and OK ramps up. The 00z NAM and latest HRRR seem to have the nest handle on the current situation and followed the general theme of increasing convective activity into the terminals as we move into the pre- dawn hours of Friday morning. With increasing confidence on a convective complex forming have lowered ceilings into the MVFR category with MVFR visibilities. Should the expected complex take dead aim on any of the terminals the risk of IFR ceilings/visibilities will increase...and most likely in the 10-13z time period. Should see convection drop off considerably by mid morning with ceiling improving to VFR. Still the potential for late afternoon/early evening re-development of convection but with continued low confidence it will affect the KMCI/KMKC terminals. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...FLASH FLOOD WATCH through this evening FOR KSZ025-057-060- 102>105. MO...FLASH FLOOD WATCH through this evening FOR MOZ001>008-011>017- 020>025-028>033-037>040-043>046-053-054. && $$ UPDATE...MJ SHORT TERM...CDB LONG TERM...Hawblitzel AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1158 PM CDT THU MAY 30 2013 .UPDATE... ISSUED AT 840 PM CDT THU MAY 30 2013 CONVECTIVE TRENDS ARE PROCEEDING ABOUT AS ANTICIPATED THIS EVENING. WHILE MUCH OF THE SHORT TERM UPDATING WILL BE REACTIVE FOR THE REST OF THE NIGHT...GENERALLY SPEAKING I EXPECT THE LINE OF STORMS NOW MOVING THROUGH SOUTHWEST/SOUTH CENTRAL MISSOURI TO CONTINUE MOVING STEADILY EAST FOR THE REST OF THE EVENING INTO THE OVERNIGHT HOURS. THE RAP CONTINUES TO SHOW A VERY STRONG LOW LEVEL JET WITH TREMENDOUS MOISTURE CONVERGENCE OVER THE AREA FOR MUCH OF THE REST OF THE NIGHT...AND THE HRRR SLOWS THE LINE FURTHER OVER SOUTHERN AND EASTERN SECTIONS OF THE CWFA. IT ALSO DEVELOPS THE CONVECTION NOW PERCOLATING OVER CENTRAL AND EASTERN KANSAS INTO ANOTHER HEAVY RAIN PRODUCING MCS BEFORE BY 10Z AND IT MOVES EAST INTO OUR AREA BY AROUND 12Z. DUE TO THE POTENTIAL FOR ADDITIONAL HEAVY RAIN TONIGHT AND TOMORROW MORNING...AM GOING TO EXPAND THE FLASH FLOOD WATCH TO THE REMAINDER OF THE AREA STARTING IMMEDIATELY AND CONTINUING TO 12Z SATURDAY. CARNEY && .SHORT TERM...(THROUGH LATE TONIGHT) ISSUED AT 240 PM CDT THU MAY 30 2013 TORNADO WATCH CONTINUES UNTIL 8 PM. ATMOSPHERE OUTSIDE OF OUTFLOW COOLED AIR HAS BECOME QUITE UNSTABLE WITH MLCAPES ABOVE 2000 J/KG. AT THE SAME TIME...DEEP LAYER SHEAR IS INCREASING IN RESPONSE TO APPROACHING TROUGH CURRENTLY OVER THE CENTRAL PLAINS. THIS TROUGH IS THE MAIN FOCUS FOR LARGE SCALE ASCENT TONIGHT AND CONSEQUENTLY IT WILL DETERMINE THE OVERALL PRECIPITATION TRENDS. RAP SHOWS THIS TROUGH MOVING ACROSS THE CWA AROUND 06Z...SO CURRENT THINKING IS THAT LINE OF STORMS OVER WESTERN MO WILL CONTINUE TO SLOWLY MOVE EAST ACROSS THE AREA LATER THIS AFTERNOON AND EVENING. AFOREMENTIONED INSTABILITY AND SHEAR STILL FAVORS THE POTENTIAL FOR A FEW SUPERCELLS OR ORGANIZED MULTI-CELLS THAT COULD PRODUCE LARGE HAIL AND DAMAGING WINDS. LOW LEVEL SHEAR ALSO SUGGESTS THAT ONE OR TWO TORNADOES COULD FORM IN THE STRONGER STORMS. STILL LOOKS REASONABLE THAT WESTERN MO LINE WILL EXIT THE EASTERN COUNTIES LATER THIS EVENING. OUTFLOW FROM THE LINE WILL LIKELY STALL OVER SOUTHERN MO...SO KEPT CHANCE OF THUNDERSTORMS GOING IN THE SOUTHERN CWA INTO THE OVERNIGHT HOURS. STILL EXPECT REDEVELOPMENT OF THUNDERSTORMS OVER WESTERN MO ON THE NOSE OF THE LOW LEVEL JET OVERNIGHT THAT WILL MOVE INTO NORTHEAST AND CENTRAL MO TOWARD 12Z. FLASH FLOOD WATCH WILL CONTINUE AS IS. HEAVIEST RAINFALL WILL FOCUS OVER THE WATCH AREA TONIGHT AND THE SOUTHERN AND EASTERN COUNTIES HAVE HIGH FLASH FLOOD GUIDANCE. ATMOSPHERE IS VERY MOIST AND DEEP LAYER FLOW FAVORS TRAINING TONIGHT. .LONG TERM...(FRIDAY THROUGH NEXT THURSDAY) ISSUED AT 240 PM CDT THU MAY 30 2013 CONVECTIVE TRENDS ARE SOMEWHAT UNCLEAR FOR FRIDAY MORNING. SOME GUIDANCE SHOWS LINGERING CONVECTION ACROSS THE EASTERN OZARKS AND SOUTHERN ILLINOIS. THIS COULD BE POSSIBLE IF THE AFOREMENTIONED OUTFLOW BOUNDARY FROM THURSDAY NIGHT`S CONVECTION IS STILL IN PLACE OVER THOSE AREAS. HOWEVER...MOST OF THE GUIDANCE SHOWS A DRYING TREND BY AROUND 12Z ACROSS THE AREA. THEN...THE LOW LEVEL JET REFOCUSES BACK OVER NORTHERN/NORTHWESTERN MISSOURI. ALL GUIDANCE SHOWS A TREMENDOUS AMOUNT OF MOISTURE CONVERGENCE IN THAT AREA STARTING ABOUT 12Z AND RAIN DEVELOPING BETWEEN 12Z AND 15Z...SPREADING INTO NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS PROBABLY DURING THE MID TO LATE MORNING. INSTABILITY WILL BUILD RAPIDLY DURING THE LATE MORNING WITH MUCAPE EXCEEDING 2500 J/KG ACCORDING TO MOST GUIDANCE AND DEEP LAYER SHEAR AROUND 50-60KTS SO SEVERE STORMS WILL BE POSSIBLE AT ANY TIME DURING THE LATE MORNING. HOWEVER...THE MAIN SHOW WILL LIKELY DEVELOP DURING THE LATE AFTERNOON OR EARLY EVENING AS ANOTHER LOBE OF VORTICITY WRAPS AROUND THE SOUTH SIDE OF THE UPPER LEVEL LOW AND PUSHES THE SURFACE FRONT INTO NORTHWEST MISSOURI. WHATEVER`S LEFT OF THE CAP WILL ALSO BE WIPED AWAY. AFTERNOON CAPE VALUES LOOK TO BE IN EXCESS OF 3000 J/KG WITH SHEAR STAYING ABOVE 50KTS. THINK THERE WILL BE SOME DISCRETE STORMS INITIALLY...BUT WITH LITTLE OR NO CAP AND COPIOUS CAPE WE SHOULD SEE THE STORMS CONGEAL INTO A LINE. CANNOT RULE OUT ANY KIND OF SEVERE WEATHER INCLUDING DAMAGING WINDS...LARGE HAIL...AND EVEN TORNADOES WITH THE LINE. THE LINE SHOULD PROGRESS AT A MODERATE PACE INTO SOUTHEAST MISSOURI BY EARLY MORNING SATURDAY. OF COURSE WITH THE HEAVY RAIN POTENTIAL AND NEARLY SATURATED GROUND THERE WILL BE A CONTINUING FLASH FLOOD THREAT...AND IT`S LIKELY THE FLASH FLOOD WATCH WILL NEED TO BE EXPANDED EITHER EARLY FRIDAY MORNING OR FRIDAY AFTERNOON TO COVER THE REST OF THE CWFA. CURRENT THINKING IS THAT THE INITIAL LINE OF CONVECTION WILL WEAKEN OVER THE EASTERN OZARKS SATURDAY MORNING. HOWEVER THERE WILL BE REDEVELOPMENT BY EARLY SATURDAY AFTERNOON...PERHAPS AS FAR NORTHWEST AS THE COLUMBIA AREA...AS THE SURFACE COLD FRONT FINALLY KICKS INTO GEAR AND HEADS EAST. SPC STILL HAS THE SOUTHEASTERN 2/3 OF THE CWFA IN A SLIGHT RISK SATURDAY...INCLUDING THE STL METRO AREA AND POINTS ALONG AND EAST OF THE I-44/I-55 CORRIDORS. THE UPPER LEVEL SHORTWAVE FINALLY SWINGS THROUGH SATURDAY AFTERNOON/EARLY EVENING PUSHING THE COLD FRONT SOUTHEAST INTO THE LOWER MISSISSIPPI/TENNESSEE VALLEYS. (SUNDAY THROUGH NEXT THURSDAY) HIGH PRESSURE IS STILL EXPECTED TO BUILD ACROSS THE MIDWEST SUNDAY AND CONTROL THE WEATHER AT LEAST THROUGH MONDAY. EXPECTING BELOW NORMAL TEMPERATURES AND LESS HUMID CONDITIONS THROUGH THAT PERIOD. MEDIUM RANGE GUIDANCE IS A LITTLE FASTER THAN YESTERDAY IN PUSHING THE HIGH EAST AWAY FROM THE MID-MISSISSIPPI VALLEY. SOUTHERLY FLOW RETURNS TUESDAY AND BOTH THE GFS AND ECMWF PRINT OUT PRECIP LATE TUESDAY THROUGH THURSDAY AS A SHORTWAVE DIPS INTO THE NORTHERN PLAINS. THE GFS IS MUCH MORE DYNAMIC WITH THIS WAVE THAN THE ECMWF AND THEREFORE CRANKS OUT A LOT MORE PRECIP. HAVE OPTED TO JUST STICK WITH CHANCE POPS FOR THIS PERIOD RIGHT NOW. WILL CONTINUE TO WATCH THIS NEXT WAVE AND INCREASE POPS AS NEEDED IF BOTH MODELS CONTINUE TO TREND WETTER. CARNEY && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1157 PM CDT THU MAY 30 2013 LO STRATUS TRYING TO FORM IN VERY MOIST LO LEVEL ENVIRONMENT AND IT IS LOOKING INCREASINGLY LIKELY IT WILL SUCCEED. INITIAL BATCHES ARE OUT IN CNTRL MO BUT SHOULD EXPAND WITH TIME TO ENCOMPASS ALL THE TAF SITES BY DAYBREAK. HAVE ADDED LO-END MVFR OR IFR CIGS TO ALL TAFS. AFTER THAT...SHOULD SEE CONDITIONS IMPROVE SOME HEADING INTO LATE FRIDAY MORNING AS STRATUS GIVES WAY TO DIURNAL CU FIELD...AND LIKE THURSDAY...SHOULD GO BKN PRETTY QUICK AND INITIALLY BE MVFR CATEGORY. FURTHER IMPROVMENT TO VFR DURING AFTERNOON SEEMS LIKELY. PCPN TRENDS...LATEST BATCH OF RAIN EXITING STL METRO NOW AND WILL COMPLETELY EXIT BY 07Z...WITH ANOTHER TSRA COMPLEX TRYING TO FORM OVER ERN KS AND FAR WRN MO. SHOULD SEE THIS MATURE LATE TONIGHT AND BEGIN MAKING AN APPROACH TO KCOU AROUND DAYBREAK AND KUIN DURING MID-MORNING. EVENTUALLY...THIS SHOULD EXPAND AS IT ENTERS A DE-STABILIZING ATMOSPHERE AHEAD OF IT AND MUCH LIKE THURSDAY...THE MAIN BODY OF IT PUSH INTO STL METRO DURING FRIDAY EVENING. THIS SHOULD LINGER TO SOME EXTENT WELL INTO THE NIGHT FOR ALL THE TAF SITES...ALTHOUGH THE WORST SHOULD HAVE PUSHED TO THE SE BY LATE FRIDAY NIGHT. SPECIFICS FOR KSTL...LO STRATUS LOOKS INCREASINGLY LIKELY BY DAYBREAK...BUT SHOULD GIVE WAY TO DIURNAL CU AT SOMEWHAT HIGHER BASES LATE FRIDAY MORNING...NEXT ROUND OF RAIN SHOULD HOLD OFF AGAIN UNTIL FRIDAY EVENING ALTHOUGH CAN/T FULLY RULE OUT AN ISOLD OCCURRENCE AHEAD OF IT IN THE MOIST AND UNSTABLE AIRMASS. TES && .LSX WATCHES/WARNINGS/ADVISORIES... MO...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR AUDRAIN MO-BOONE MO-CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO- IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO- MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. IL...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR ADAMS IL-BOND IL- BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL- PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
823 PM MDT SAT JUN 1 2013 .UPDATE... A PRETTY QUIET NIGHT IS IN STORE EVEN AS THE HEIGHTS BEGIN FALLING A BIT ALOFT IN ADVANCE OF THE 500-HPA SHORT WAVE TROUGH NOTED OVER SOUTHERN BRITISH COLUMBIA THIS EVENING. OTHER THAN SOME HIGH-LEVEL CLOUDS CROSSING THE AREA...THE ONLY OTHER ITEM OF NOTE WILL BE THE 20 TO 30 PERCENT CHANCE OF SHOWERS AFTER 06 UTC FROM HARLOWTON AND JUDITH GAP OVER TOWARD RYEGATE. WEAK MID-LEVEL INSTABILITY AND THE PRESENCE OF A WEAK LOW-LEVEL JET IN THAT AREA SUPPORT THE CHANCES. WE DID PULL THE ADVERTISED SLIGHT CHANCE OF SHOWERS ANOTHER ROW OF COUNTIES SOUTH OF THE PREVIOUS FORECAST OUT OF RESPECT TO THE SREF FROM 21 UTC AND THE POSITION OF WEAK MID-LEVEL INSTABILITY ON SOME RECENT RAP RUNS. OTHERWISE...ONLY MINOR CHANGES WERE MADE WITH THE UPDATE TO TONIGHT/S FORECAST. SCHULTZ && .SHORT TERM...VALID FOR SUN AND MON... THE NEXT SYSTEM THAT WILL AFFECT THE AREA WAS PUSHING ONSHORE INTO WA AND S BC PER WATER VAPOR IMAGERY THIS AFTERNOON. THE MODELS WERE IN GOOD AGREEMENT WITH THE TRACK OF THE UPPER LOW. UPPER DIFLUENCE AND SHORTWAVE ENERGY WILL MOVE OVER THE AREA ON SUN. THE UPPER LOW WILL REACH N CENTRAL MT BY 12Z MON AND WILL MOVE SLOWLY E THROUGH THE STATE THROUGH 12Z TUE. A SHORTWAVE WILL ACCOMPANY THE LOW AND PUSH A COLD FRONT THROUGH THE AREA SUN NIGHT THROUGH MON MORNING. MUCH COOLER AIR WILL SPILL S INTO THE REGION BEHIND THE SYSTEM BY TUE MORNING. SOME MOISTURE WILL REACH THE NW FRINGES OF THE FORECAST AREA BY SUN MORNING IN THE AREA OF UPPER DIFLUENCE SO HAVE ADDED POPS TO THIS AREA LATE TONIGHT THROUGH SUN MORNING. MODELS WERE IN DECENT AGREEMENT IN DEVELOPING PRECIPITATION OVER THE WESTERN ZONES SUN AFTERNOON SO HAD CHANCE TO LIKELY POPS THERE. CHANCES FOR PRECIPITATION WILL SPREAD E SUN EVENING AS STRONG FRONTOGENESIS PUSHES INTO THE AREA. THE HIGHEST QPF LOOKS TO BE OVER THE NW CORNER OF THE AREA. AROUND A HALF INCH OF QPF WILL BE POSSIBLE IN THIS AREA SUN EVENING. WHILE SHEAR WILL BE FAVORABLE FOR STRONG THUNDERSTORMS SUN AFTERNOON AND EVENING...CAPE VALUES WERE VERY LOW...SO WILL NOT MENTION ANY STRONG OR SEVERE STORMS FOR NOW. RAISED HIGH TEMPERATURES A LITTLE ON SUN. BEST PRECIPITATION CHANCES WILL BE ACROSS THE NORTHERN ZONES LATE SUN NIGHT THROUGH MON MORNING IN THE VICINITY OF THE EASTWARD MOVING LOW. THE SHORTWAVE WILL SWEEP THROUGH THE AREA MON AFTERNOON BRINGING A GOOD CHANCE OF PRECIPITATION. CHANCES FOR PRECIPITATION WANE MON NIGHT AS ENERGY MOVES E OF THE AREA. TEMPERATURES WILL CHALLENGING ON MON DUE TO THE FRONTAL PASSAGE. CONTINUED THE FORECAST OF READINGS IN THE 60S. THREAT FOR STRONG STORMS LOOKED MINIMAL FOR MON AS STRONG SHEAR QUICKLY EXITS THE AREA AS THE COLD FRONT MOVES E. CAPE VALUES WERE ALSO NOT VERY HIGH. ARTHUR .LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT... MEDIUM RANGE GUIDANCE IN OVERALL GOOD AGREEMENT. AN UPPER LOW OVER NORTH DAKOTA ON TUESDAY WILL RESULT IN CYCLONIC FLOW BACK ACROSS EASTERN MT. A FEW SHOWERS WILL REMAIN POSSIBLE IN AN UNSTABLE NORTHWEST FLOW...BUT ONLY LOW SCATTERED THREAT AS MAIN IMPACTS SHOULD STAY ACROSS NORTHERN MT WITH SOUTHERN MT BATTLING WITH THE DOWNSLOPE FLOW. WEDNESDAY INTO EARLY THURSDAY...SHORT WAVE RIDGING MOVES ACROSS FOR MOSTLY DRY CONDITIONS AND WARMER CONDITIONS. AS UPPER RIDGING BUILDS ACROSS WEST COAST FOR LATE IN THE WEEK INTO SATURDAY...AN UNSTABLE NORTHWEST FLOW DOMINATES THE NORTHERN ROCKIES WITH A SERIES OF WAVES OFFERING UP PRECIP CHANCES BEGINNING LATE THURSDAY INTO SATURDAY. RIGHT NOW...BEST CHANCES APPEAR TO BE LATE FRIDAY INTO SATURDAY AND SO HAVE RAISED PRECIP CHANCES FOR THIS TIMEFRAME. WARMEST DAY SETTING UP FOR THURSDAY...THEN COOLER UNDER UNSTABLE NORTHWEST FLOW. HAVE TRENDED TEMPERATURES DOWN SEVERAL DEGREES DEEP INTO EXTENDED. FRIEDERS && .AVIATION... VFR CONDITIONS WILL GENERALLY PREVAIL OVERNIGHT WITH SOME MID- AND HIGH-LEVEL CLOUDS CROSSING THE AREA. THERE IS A SMALL CHANCE FOR A SHOWER AROUND K3HT BETWEEN 06 AND 18 UTC. A BETTER CHANCE FOR SOME SHOWERS AND THUNDERSTORMS AND POSSIBLY MVFR CONDITIONS WILL ARRIVE IN SOUTH CENTRAL MT BY LATE SUNDAY AFTERNOON. SCHULTZ && .PRELIMINARY POINT TEMP/POPS... SUN MON TUE WED THU FRI SAT ----------------------------------------------------------- BIL 049/075 050/067 042/064 047/071 052/075 053/072 054/073 11/B 64/T 32/T 10/B 11/B 14/T 43/T LVM 043/073 043/065 037/062 039/071 045/073 046/070 047/071 13/T 55/T 33/T 21/U 12/T 24/T 43/T HDN 046/078 049/070 042/065 044/072 050/075 053/072 054/073 11/B 34/T 32/T 10/B 01/B 13/T 33/T MLS 047/076 051/065 043/064 045/070 051/074 053/074 054/072 00/B 57/T 43/T 20/B 01/U 13/T 44/T 4BQ 043/076 046/069 041/062 044/068 047/073 051/075 052/070 00/B 23/T 32/T 10/B 01/U 14/T 44/T BHK 041/070 046/065 041/060 041/065 046/070 049/073 050/068 00/B 45/T 44/T 22/W 11/B 13/T 44/T SHR 042/076 048/069 039/062 041/067 045/075 048/071 049/071 00/B 24/T 33/T 21/B 12/T 24/T 43/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
711 PM CDT SAT JUN 1 2013 .UPDATE... ISSUED AT 710 PM CDT SAT JUN 1 2013 ONLY MADE A FEW FAIRLY MINOR TWEAKS TO THE FORECAST FOR THE EARLY EVENING UPDATE. FIRST OF ALL...SLIGHTLY SLOWED THE DECREASE IN WIND SPEEDS THIS EVENING...AS MANY SITES CONTINUE TO REPORT SUSTAINED SPEEDS OF 20+ MPH...AND IT LOOKS LIKE SUSTAINED SPEEDS TO AROUND 15 MPH MAY STILL BE PRESENT ACROSS MUCH OF THE EASTERN 1/2 OF THE CWA EVEN AT 10 PM WITH LOWER VALUES IN THE WEST...ALTHOUGH ALL AREAS SHOULD LEGITIMATELY SETTLE TO AROUND/UNDER 10 MPH BY MIDNIGHT OR SO AS HIGH PRESSURE CONTINUES BUILDING IN. GIVEN THAT SUSTAINED SPEEDS ARE ALREADY SAFELY UNDER 30 MPH IN ALL AREAS...WILL BE REMOVING WIND WORDING FROM THE HAZARDOUS WEATHER OUTLOOK...RESULTING IN NO HAZARD MENTION FOR THE REST OF THE NIGHT AS THE REGION CONTINUES ITS FAIRLY BRIEF RESPITE FROM THUNDERSTORM ACTIVITY. THE OTHER TRICKY ISSUE FOR THE OVERNIGHT HOURS WILL BE THE FATE OF THE LOW STRATUS DECK GENERALLY IN THE 3000-5000 FT RANGE. CURRENT EXPECTATION IS FOR A STEADY EROSION OF THIS STRATUS FROM WEST TO EAST AS THE EVENING GOES ON...MUCH IN LINE WITH CURRENT FORECAST. HOWEVER...WILL HAVE TO SEE IF THE 21Z RAP MAY BE ONTO SOMETHING WITH ITS 900 MILLIBAR RELATIVE HUMIDITY FIELD...AS IT SUGGESTS THAT QUITE A BIT OF LOW CLOUD COVER COULD HANG ON OR MOVE BACK INTO PRIMARILY THE EASTERN 1/2 OF THE CWA TONIGHT...WHICH COULD OBVIOUSLY HAVE AT LEAST A SLIGHT IMPACT ON OVERNIGHT LOW TEMPS. NO CHANGES MADE TO LOW TEMPS AT THIS TIME...WHICH ARE STILL LOOKING TO AVERAGE AROUND 10 DEGREES BELOW NORMAL IN THE LOW-MID 40S FOR MUCH OF THE CWA. HOWEVER...PLEASE NOTE THAT FORECAST LOWS FOR OUR PRIMARY CLIMATE SITES GRAND ISLAND/HASTINGS ARE STILL 5 DEGREES ABOVE RECORD LOWS FOR JUNE 2ND...WHICH FOR GRAND ISLAND IS 39 IN 1964...AND HASTINGS IS 40 IN 1964/1951. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 247 PM CDT SAT JUN 1 2013 UPPER AIR PROFILER AND SATELLITE DATA THIS AFTERNOON SHOWING THE MAIN TROUGH AXIS CONTINUING TO GRADUALLY MAKE ITS WAY EAST/SOUTHEAST THROUGH THE PLAINS...WITH NORTHWESTERLY FLOW BUILDING IN BEHIND. AS EXPECTED...THIS DISTURBANCE BROUGHT A FEW SPRINKLES TO THE AREA /MAINLY THIS MORNING/...AND HAS KEPT PLENTY OF CLOUD COVER AROUND THROUGH THE DAY. HAS ALSO BEEN A BREEZY/WINDY DAY...WHILE SURFACE LOW PRESSURE OVER MN/WI HAS BEEN SLOW TO SHIFT EAST...HIGH PRESSURE HAS CONTINUED TO BUILD IN FROM THE WEST BEHIND THE MAIN FRONT. THIS TIGHTENED PRESSURE GRADIENT RESULTED IN SUSTAINED WINDS OF 20 TO 30 MPH...AND AT TIMES GUSTS IN THE 40 MPH AREA. DID HAVE SOME SITES ON OCCASION HITTING WIND ADV CRITERIA. THROUGH THE REST OF THE SHORT TERM PERIOD...THE FORECAST REMAINS DRY. MODELS REMAIN IN GOOD AGREEMENT IN THE UPPER LEVELS...SHOWING BROAD RIDGING SETTING UP OVER THE ROCKIES/PLAINS...BETWEEN AREAS OF LOW PRESSURE LOCATED OVER ONTARIO AND THE ID/MONT/CANADIAN BORDER REGION. THIS WILL KEEP ANY PRECIPITATION CHANCES WELL OUT OF THE CWA...AND HELP MAKE FOR A VERY PLEASANT SUNDAY. AT THE SURFACE...THE PATTERN THROUGH THE SHORT TERM WILL BE DOMINATED BY HIGH PRESSURE. THIS FEATURE WILL CONTINUE TO BUILD IN FROM THE WEST TONIGHT...AND THERE IS A LITTLE UNCERTAINTY WITH JUST HOW FAR EAST THE RIDGE AXIS WILL GET. THE NAM IS ON THE FURTHEST EAST SIDE OF THINGS...SHOWING THE RIDGE AXIS ACTUALLY THROUGH THE CWA BY 12Z SUNDAY...WITH MOST OF THE SUPPORT SHOWING THE RIDGE AXIS STAYING JUST TO/SET UP OVER THE WRN FRINGE OF THE CWA. WINDS WILL BE DIMINISHING WITH TIME...BUT DEPENDING ON WHERE THE RIDGE SETS UP WILL DETERMINE WHETHER WINDS BECOME CALM...AND COULD AFFECT LOW TEMPERATURES TONIGHT. STAYED FAIRLY CLOSE TO GUIDANCE FOR LOWS...WHICH BRING LOWER/MID 40S TO THE CWA. IF THE WINDS STAY UP...THIS MAY BE TOO COOL. SUNDAY...SHOULD SEE PLENTY OF SUNSHINE ACROSS THE AREA...WITH THE SURFACE HIGH KEEPING WINDS LIGHT. SHOULD START TO SEE AN INCREASE IN TEMPS ALOFT STARTING TO SHIFT IN FROM THE WEST...AND HIGHS ARE EXPECTED TO REACH INTO THE LOWER/MID 70S /COMBINED WITH DEWPOINTS ONLY IN THE 40S/. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 247 PM CDT SAT JUN 1 2013 AS SFC RIDGE CONTINUES TO DEPART TO THE EAST AND SFC LOW DEEPENS ALONG THE HIGH PLAINS...SOUTHERLY LLVL FLOW INCREASES SUNDAY NIGHT. THE LLVL JET STRENGTHENS TO NEAR 50KTS AND IN INCREASING SOUTHERLY FLOW...MOISTURE AGAIN IS DRAWN NORTH INTO THE PLAINS STATES SUNDAY NIGHT/MONDAY. WARM FRONT LIFTS NORTHEAST ON MONDAY AND TEMPS WILL TREND WARMER...CLOSER TO SEASONAL READINGS IN THE UPPER 70S/LOW 80S. MONDAY WILL NOT BE WITHOUT WIND HOWEVER AS SFC GRADIENT REMAINS TIGHT AND FORECAST SOUNDINGS SUGGEST MIXING TO AT LEAST H8. WINDS DO NOT APPEAR TO REACH WIND ADV CRITERIA JUST YET...BUT WILL NEED TO MONITOR. DURING THE DAY ON MONDAY SHOULD REMAIN DRY...HOWEVER DID HOLD ONTO SOME LOW POPS IN THE WAA REGIME...BUT GENERALLY EXPECT CAPPING TO HOLD IN THE EAST DURING THE AFTN WHILE BETTER CONVECTIVE POTENTIAL/INITIATION FOCUSES TO THE WEST ALONG THE HIGH PLAINS ALONG SFC TROUGH/DRYLINE EDGING INTO SW NEB/WESTERN KANSAS...AND TO THE NW ALONG SFC TROUGH/COOL FRONTAL BOUNDARY. CONVECTION IS THEN EXPECTED TO PUSH SOUTH AND EASTWARD MONDAY NIGHT AS THE NORTHERN BOUNDARY REACHES CENTRAL NEBRASKA AHEAD OF THE UPPER TROUGH IN THE DAKOTAS. AN INSTABILITY AXIS OF 2000 TO 2500 J/KG WILL REACH CENTRAL NEB MONDAY NIGHT WITH SHEAR OF 30 TO 40KTS...AND SEVERE STORMS ARE POSSIBLE IN THIS ENVIRONMENT MONDAY NIGHT...WITH HAIL/WIND PRIMARY HAZARDS FOR THE MAINLY NOCTURNAL CONVECTION. TUESDAY MAY SEE ONGOING CONVECTION IN THE MORNING WITH OUTFLOW BOUNDARY AND/OR SFC WARM FRONTAL BOUNDARY POTENTIALLY STALLING OUT...BUT THIS WILL BE DEPENDENT ON CONVECTION MONDAY NIGHT. MOISTURE POOLS ALONG THE BOUNDARY ON TUESDAY WITH SREF INDICATING INSTABILITY OF 3000 TO 4000 J/KG ACROSS NORTH CENTRAL KS WITH INSTABILITY AXIS EXTENDING INTO SC NEB...WITH SHEAR ON THE ORDER OF 40KTS. IF BOUNDARY POSITION IS CLOSE/ACROSS OUR CWA...STORMS ARE EXPECTED TO INITIATE ACROSS OUR AREA TUESDAY AFTN/EVE IN VCNTY OF BOUNDARY WITH SEVERE STORMS AGAIN LIKELY. SETUP WOULD BE FAVORABLE FOR LARGE HAIL/DAMAGING WINDS/TORNADOES NEAR THE BOUNDARY...AND HEAVY RAINFALL. ADDITIONAL CONVECTIVE DEVELOPMENT IS POSSIBLE ALONG THE HIGH PLAINS/DRY LINE AREA AND TO THE NW WITH APPROACHING TROUGH/SECONDARY COOL FRONT. BEYOND THIS TIME FRAME...TOO DIFFICULT TO TRY TO NAIL DOWN THE DETAILS AS BOUNDARY PLACEMENT WILL BE DEPENDENT UPON CONVECTION WHICH DEVELOPS EACH DAY/NIGHT. ON WEDNESDAY...FRONT MAY LINGER IN OUR SOUTHEAST ZONES...THEN BETTER CHCS FOR STORMS BEGIN TO SHIFT SE ALONG BOUNDARY WHILE THE UPPER SYSTEM/LOW REACHES THE UPPER MIDWEST. IN THEORY WE SHOULD SEE A LULL/BREAK IN CONVECTION POTENTIAL FOR A PERIOD OR TWO...THEN PATTERN LOOKS ACTIVE AGAIN HEADING INTO NEXT WEEKEND. FOR TEMPERATURES...IT IS NOT LOOKING OVERLY WARM OR COLD...WITH HIGHS DEPENDENT UPON WHICH SIDE OF BOUNDARY YOU ARE ON...BUT CLOSE TO SEASONAL NORMALS OVERALL. && .AVIATION...(FOR THE 00Z KGRI TAF THROUGH 00Z SUNDAY EVENING) ISSUED AT 640 PM CDT SAT JUN 1 2013 THE WINDS ARE EXPECTED TO TAPER DOWN THIS EVENING AS HIGH PRESSURE BUILDS INTO THE AREA. CURRENT VISIBLE SATELLITE TRENDS SHOW MVFR CEILINGS SLOWLY MOVING EAST AND LOOK TO SCATTER OUT IN THE NEXT FEW HOURS. A FEW MODELS BRING MVFR CEILINGS BACK INTO NIGHT...WILL MONITOR...CURRENTLY LEANING TOWARDS KEEPING THEM OUT OF THE TAF. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...PFANNKUCH SHORT TERM...ADO LONG TERM...FAY AVIATION...BEDA
AREA FORECAST DISCUSSION
NWS HASTINGS NE
322 PM CDT FRI MAY 31 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 319 PM CDT FRI MAY 31 2013 IN THE SYNOPTIC SCALE...THE LARGE UPPER LEVEL LOW PRESSURE SYSTEM THAT HAS AFFECTED OUR WEATHER THE PAST FEW DAYS...CONTINUES TO SPIN ACROSS THE DAKOTAS...WHILE RIDGING CONTINUES JUST OFF BOTH THE WESTERN AND EASTERN COASTS. IN THE MID LEVELS...THIS SYSTEM CONTINUES TO SURGE AN ABUNDANCE OF GULF COAST MOISTURE UP THE MISSISSIPPI RIVER VALLEY INTO THE MIDWEST...AS SEEN IN RECENT FLOODING ASSOCIATED WITH THUNDERSTORMS ACROSS THE COUNTRY`S MIDSECTION. AT THE SURFACE...THE SYSTEM REMAINS NEARLY VERTICALLY STACKED WITH LOW PRESSURE ALSO ALIGNED OVER THE DAKOTAS...AND A SECONDARY LOW SITUATED SOUTH OF THE TROUGH AXIS ACROSS SOUTHEASTERN KANSAS. AS THE LOW PRESSURE SYSTEM CONTINUES TO SPIN...ALMOST NEARLY STATIONARY...THE MAIN COLD FRONTAL BOUNDARY HAS ALREADY SHIFTED THROUGH THE OUTLOOK AREA. HOWEVER...IT APPEARS A SECONDARY WEAK TROUGH AXIS WILL ALSO SHIFT THROUGH THE AREA OVERNIGHT TONIGHT. WITH THIS BOUNDARY...CONCERNS IN THE SHORT TERM WILL FOCUS MAINLY ON PRECIPITATION CHANCES AND COOLER HIGH TEMPERATURES TOMORROW. STARTING OFF THIS AFTERNOON...WATER VAPOR IMAGERY INDICATES THE PRESENCE OF A WEAK SHORT WAVE TROUGH SLIDING THROUGH EASTERN COLORADO SOUTH OF THE UPPER LEVEL LOW. AN AREA OF CUMULUS HAVE DEVELOPED ACROSS THE AREA...AND BEGUN TO SPREAD NORTHEAST AS SEEN ON VISIBLE SATELLITE. RADAR ALSO INDICATES AT LEAST SOME VERY LIGHT RETURNS ACROSS NORTHWEST AND NORTH CENTRAL KANSAS. WENT AHEAD AND PUT IN SLIGHT CHANCE POPS ACROSS NORTH CENTRAL KANSAS THROUGH THE AFTERNOON...AS BOTH THE HRRR AND NAM MODEL SEEM TO BE HANDLING THIS WELL. NOT EXPECTING MUCH MORE THAN A COUPLE SPRINKLES AND MAYBE A RUMBLE OF THUNDER. HEADING INTO THE OVERNIGHT HOURS...LATEST SATELLITE IMAGERY SHOWS THE DEVELOPMENT OF A CUMULUS FIELD ACROSS MUCH OF NORTHWESTERN NEBRASKA JUST BEHIND THE SECONDARY TROUGH AXIS. EXPECT THIS TROUGH AXIS TO SLIDE THROUGH THE OUTLOOK AREA ROUGHLY AROUND 6Z...WITH WEST WINDS SHIFTING TO THE NORTHWEST. CONTINUED SLIGHT POPS FOR THE NORTHERN HALF OF THE OUTLOOK AREA OVERNIGHT...AS BOTH THE NAM AND HRRR INDICATE AT LEAST SOME LIGHT SHOWERS TO PUSH THROUGH. THE UPPER LEVEL LOW WILL FINALLY BEGIN TO SHIFT EASTWARD BY SATURDAY...THUS DECREASING POPS FROM SOUTHWEST TO NORTHEAST THROUGHOUT THE DAY. INSTABILITY THROUGHOUT MUCH OF THE SHORT TERM PERIOD...REMAINS FAIRLY MINIMAL...WITH ONLY ABOUT 100 J/KG OR SO AT MOST. CONTINUED WITH MENTION OF ONLY LIGHT RAIN SHOWERS AS A RESULT...AND LEFT OUT MENTION OF THUNDER. REGARDING TEMPERATURES ON SATURDAY...BEHIND THIS SECONDARY TROUGH AXIS...COOLER AIR...WITH 850 MB TEMPERATURES ON THE ORDER OF 3 TO 4 DEGREES CELSIUS WILL SLIDE SOUTH INTO THE OUTLOOK AREA. THUS...COMBINED WITH MODEL GUIDANCE...CONTINUED WITH TEMPERATURES IN THE LOWER 60S ACROSS THE NORTH TO NEAR 70 IN NORTH CENTRAL KANSAS FOR SATURDAY. SATURDAY LOOKS TO BE SHAPING INTO A FAIRLY UNPLEASANT DAY...WITH MOSTLY CLOUDY SKIES AND COOLER TEMPERATURES. TO ADD TO THE MIX...STRONG NORTHWEST WINDS SUSTAINED NEAR 20 KTS CAN BE EXPECTED...AND WITH SOME MIXING WILL LEAD TO GUSTS NEAR 30 KTS. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 319 PM CDT FRI MAY 31 2013 MAIN FORECAST CONCERNS WILL BE CHANCES FOR THUNDERSTORMS AND TEMPERATURES. AN UPPER LEVEL SHORT WAVE RIDGE WILL MOVE ACROSS THE AREA SATURDAY NIGHT THROUGH SUNDAY NIGHT. DURING THIS TIME DRY CONDITIONS ARE EXPECTED. A SURFACE HIGH WILL SETTLE INTO THE AREA SATURDAY NIGHT AND KEEP WINDS LIGHT AND TEMPERATURES WILL DROP TO THE 40S. BY SUNDAY THE SURFACE HIGH WILL MOVE OFF TO THE EAST. WINDS WILL TURN TO THE SOUTH AND AS THE PRESSURE GRADIENT TIGHTENS...THE WINDS WILL INCREASE DURING THE DAY ON SUNDAY. TEMPERATURES WILL BE WARMER FOR SUNDAY AND SUNDAY NIGHT. FOR MONDAY THROUGH FRIDAY ANOTHER UPPER LEVEL LOW WILL WORK ITS WAY FROM THE PACIFIC NORTHWEST...THROUGH THE NORTHERN ROCKIES AND INTO THE NORTHERN PLAINS. THIS IS A SIMILAR TRACK TO THE ONE FROM THE PAST WEEK. BY MONDAY THE UPPER LOW STARTS TO SEND THE FIRST SHORT WAVE INTO THE AREA AND BRINGS A CHANCE FOR THUNDERSTORMS. MODELS BRING SEVERAL SHORT WAVES THROUGH THE AREA DURING THE WEEK. THERE ARE SOME MINOR TIMING DIFFERENCES BETWEEN THE MODELS. THE CHANCE FOR THUNDERSTORMS CONTINUES DURING THE WORK WEEK AS THE UPPER LOW CONTINUES TO SEND SHORT WAVES INTO THE AREA. IT WILL NOT BE RAINING ALL OF THE TIME AND THERE MAY BE TIMES WHERE SOME LOCATIONS DO NOT HAVE ANY PRECIPITATION DURING SOME PERIODS... BUT THERE IS AT LEAST A SMALL CHANCE EVERY DAY. THE BEST CHANCES SHOULD BE DURING THE AFTERNOON AND INTO THE OVERNIGHT HOURS. SOME OF THE STORMS COULD BE SEVERE DURING THIS PERIOD. THE BEST CHANCE FOR SEVERE WILL BE TUESDAY AND TUESDAY NIGHT WHEN THE MUCAPE APPROACHES 2500 J/KG. THERE COULD BE SOME ISOLATED SEVERE AT OTHER TIMES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1242 PM CDT FRI MAY 31 2013 WHILE VFR CONDITIONS WILL CONTINUE THROUGHOUT MOST OF THE TAF PERIOD...THERE IS AT LEAST SOME CONCERN FOR MVFR CEILINGS TOWARDS THE END OF THE PERIOD. AN UPPER LEVEL LOW PRESSURE SYSTEM CENTERED ACROSS THE DAKOTAS THIS MORNING WILL CONTINUE TO HAVE AN EFFECT ON THE PLAINS THROUGHOUT THE PERIOD. LATEST SATELLITE IMAGERY INDICATES A CUMULUS FIELD DEVELOPING ACROSS MOST OF THE NORTHWESTERN HALF OF NEBRASKA. CURRENT THINKING IS THAT THESE CLOUDS WILL BEGIN TO SHIFT THROUGH THE TAF SITE AFTER 0Z...WITH LOWERING CLOUD BASES THEREAFTER. COMBINED WITH THESE CLOUDS...AN ASSOCIATED TROUGH AXIS WILL ALSO PUSH THROUGH THE PLAINS ROUGHLY AROUND 6Z...WHICH WILL HELP BRING A SLIGHT WIND SHIFT TO THE NORTHWEST. LATEST MODEL TRENDS INDICATE AT LEAST SOME CHANCE THAT SHOWERS ASSOCIATED WITH THIS TROUGH AXIS WILL BE OVER OR JUST NORTH OF THE TAF SITE BY THE MORNING HOURS ON SATURDAY. THUS CONTINUED WITH LIGHT RAIN SHOWER MENTION AFTER 10Z SATURDAY. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...SALTZMAN LONG TERM...JCB AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1141 PM CDT THU MAY 30 2013 .AVIATION...06Z TAFS FOR KOFK...KLNK AND KOMA. GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY EVENING. A LOW PRESSURE SYSTEM OVER THE NORTHERN PLAINS WILL BRING STRONG SOUTHWEST TO WEST WINDS ACROSS EASTERN NEBRASKA TAF SITES FRIDAY AFTERNOON. EXPECT WINDS OF 15 TO 30KT WITH SCATTERED TO BROKEN CLOUDS AT FL040. THERE IS A SMALL CHANCE FOR SHOWERS BEFORE BETWEEN 10Z AND 14Z...THEN ISOLATED THUNDERSTORMS BETWEEN 21Z AND 00Z. DID NOT INCLUDE THESE IN THE TAF AS COVERAGE IS EXPECTED TO BE ISOLATED. DERGAN && .PREV DISCUSSION... /ISSUED 1004 PM CDT THU MAY 30 2013/ UPDATE... CONVECTION IS FINALLY WINDING DOWN ACROSS EASTERN NEBRASKA AND SOUTHWEST IOWA...WITH A FEW SHOWERS AND ISOLATED LIGHTNING STRIKES OCCURRING IN PARTS OF NORTHEAST NEBRASKA AND IN AREAS EAST AND NORTHEAST OF THE COUNCIL BLUFFS METRO AREA. EXPECT IOWA ACTIVITY TO MOVE EAST OF OUR AREA WELL BEFORE MIDNIGHT...AND NORTHEAST NEBRASKA ACTIVITY TO PERSIST FOR A COUPLE OF HOURS. AFTER MIDNIGHT...SHORT RANGE HRRR AND RAP MODELS ARE BOTH SUGGESTING SOME SHOWER DEVELOPMENT IN WESTERN NEBRASKA WILL SWING EAST THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA. SOME INDICATION OF THIS ACTIVITY FORMING NOW IN SOUTHWEST NEBRASKA...SO HAVE NO REASON TO REMOVE THE CHANCE FOR MORE SHOWERS LATER TONIGHT AS PER GOING FORECAST. DERGAN PREV DISCUSSION... /ISSUED 302 PM CDT THU MAY 30 2013/ DISCUSSION... MAIN CONVECTIVE ACTIVITY HAS SHIFTED EAST OF THE AREA THIS AFTERNOON WITH CLOSED UPPER LOW LOCATED OVER WESTERN SOUTH DAKOTA AND SURFACE TROUGH JUST NOSING INTO EASTERN NEBRASKA. ALTHOUGH THE CHANCE OF THUNDERSTORMS WILL REMAIN ACROSS THE AREA TONIGHT AND FRIDAY...GENERAL TREND WILL BE TOWARD MORE STABLE CONDITIONS BY LATE SATURDAY AND THROUGH THE REMAINDER OF THE WEEKEND AS THE UPPER SYSTEM TRACKS TOWARD THE GREAT LAKES REGION AND HIGH PRESSURE BUILDS INTO THE CENTRAL PLAINS. TEMPERATURES WILL BE TURNING COOLER FOR THE WEEKEND AS A COLD FRONT MOVES THROUGH THE REGION WITH CLOUDS AND SHOWERS ASSOCIATED WITH THE UPPER LOW LIKELY TO KEEP HIGHS ONLY IN THE 60S FOR SATURDAY. BREEZY CONDITIONS ALSO EXPECTED ON SATURDAY BEHIND THE FRONT AS THE COOLER AIR MOVES INTO THE REGION. WARMER AIR RETURNS FOR SUNDAY SURFACE HIGH SHIFTS EAST WITH CONSIDERABLE SUNSHINE EXPECTED. EXTENDED PERIOD LOOKS LIKE IT COULD TURN WET AGAIN AS THE UPPER LEVEL PATTERN TAKES ON SIMILAR CHARACTERISTICS OF THIS PAST WEEKS SYSTEM. ANOTHER CLOSED LOW MOVES INTO THE NORTHERN ROCKIES BY MONDAY THEN TRACKS EAST ACROSS THE NORTHERN PLAINS AND INTO THE UPPER MIDWEST BY THURSDAY. MODELS HOWEVER DIFFER ON STRENGTH AND TIMING OF SHORT WAVES SO LIMITED CONFIDENCE IN EITHER SOLUTION AT THIS TIME. FOBERT && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
937 PM EDT SAT JUN 1 2013 .SYNOPSIS... A COLD FRONT WILL GRADUALLY APPROACH FROM THE UPPER LAKES TONIGHT...CROSSING THE REGION LATE ON SUNDAY. THIS WILL BRING AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS TONIGHT INTO SUNDAY...WITH LOCALLY HEAVY DOWNPOURS POSSIBLE. COOLER AND DRIER AIR WILL BUILD INTO THE REGION FOR THE FIRST HALF OF THE WEEK. && .NEAR TERM /THROUGH SUNDAY/... SHOWERS AND THUNDERSTORMS EXTEND ALONG A BOUNDARY WHICH EXTENDS FROM WESTERN PORTIONS OF THE SOUTHERN TIER TO EASTERN LAKE ONTARIO. THIS LINE IS FORECAST TO CONTINUE TO SLIDE EASTWARD. WITH THE LOSS OF DAYTIME HEATING AND FOLLOWING AN INITIAL ROUND OF CONVECTION...THE CHANCE FOR WINDS TO MIX DOWN IS DIMINISHED FROM EARLIER TODAY. WHILE STORMS STILL BEAR WATCHING...EXPECT THE SEVERE WEATHER POTENTIAL TO DIMINISH THROUGH LATE EVENING. FORECAST CONFIDENCE INCREASES LATER TONIGHT...DUE TO A STRONGER MODEL CONSENSUS. WITH THE HRRR ALSO LENDING SUPPORT THE OTHER GUIDANCE (NAM/RGEM/SREF/GFS)...THERE IS A HIGH CONFIDENCE IN SHOWERS AND THUNDERSTORMS MOVING IN FROM WEST TO EAST LATE TONIGHT AS AN UPPER TROF GETS CLOSER. A STRONG MODEL CONSENSUS SHOWS SOME MEASURABLE QPF IN WESTERN SECTIONS BY DAYBREAK SUNDAY...AND GIVEN THE SYNOPTIC FEATURE THIS MAKES SENSE. LATER TONIGHT...THERE IS A POTENTIAL FOR HEAVY RAIN...WITH PWATS FORECAST TO INCREASE TO 1.75 INCHES BY BOTH THE NAM/GFS. TEMPERATURES SHOULD ONLY DROP INTO THE UPPER 60S OVERNIGHT...AS WINDS/CLOUDS AND RAIN LIMIT RADIATIONAL COOLING. HIGHS ON SUNDAY SHOULD BE NOTABLY COOLER..RANGING FROM THE 70S IN WESTERN SECTIONS TO LOWER 80S ACROSS THE GENESEE VALLEY AND FINGER LAKES REGIONS. SHOWERS AND THUNDERSTORMS SHOULD TAPER OFF FROM WEST TO EAST ON SUNDAY. THIS ACTIVITY IS LIKELY TO BE ALONG A PRE-FRONTAL TROF...WITH THE ACTUAL FRONT AND WIND SHIFT LIKELY TO HOLD OFF UNTIL LATER IN THE DAY. THIS MAY SPARK AN ADDITIONAL SHOWER...WITH A SIGNIFICANT BREAK OF FAIR WEATHER POSSIBLE BETWEEN THE PRE-FRONTAL TROF AND THE FRONT ITSELF. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... THE CLOSED UPPER LOW OVER ONTARIO PROVINCE BETWEEN THE NORTHERN GREAT LAKES AND JAMES BAY WILL MOVE EAST SUNDAY NIGHT AS A POSTFRONTAL SURFACE RIDGE BUILDS ACROSS NEW YORK STATE. THIS WILL CLEAR OUT LOW LEVEL DEWPOINTS FROM THE UPPER 50S TO 60 DEGREES SUNDAY EVENING...TO THE MID 40S TO LOW 50S BY DAYBREAK ON MONDAY. THERE WILL ALSO BE A CLEARING TREND WITH THE INFLUX OF THE DRIER AIRMASS AND COLD ADVECTION WILL BRING OVERNIGHT LOWS TO THE UPPER 40S TO LOW 50S. SURFACE HIGH PRESSURE CENTER OVER SOUTHERN ONTARIO PROVINCE WILL PROVIDE A DRY AND COOL PERIOD FOR THE FIRST HALF OF THE WEEK WITH POPS NEAR ZERO AND ABUNDANT SUNSHINE. HIGH TEMPS WILL BE IN THE LOWER TO MIDDLE 60S AT THE START OF THE WEEK AND NUDGE UP TO THE MID AND UPPER 60S ON TUESDAY. DRY AIR AND CLEAR SKIES AT NIGHT WILL ALLOW LOW TEMPS TO FALL TO THE LOWER TO MID 40S FOR MOST OF THE AREA MONDAY NIGHT AND MOSTLY IN THE MID TO UPPER 40S FOR TUESDAY NIGHT. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... THE CENTER OF THE SURFACE HIGH ACROSS SOUTHERN ONTARIO WILL MOVE EASTWARD AND ALLOW A SOUTHERLY FLOW ACROSS THE FORECAST AREA. THIS WILL BRING A MIDWEEK WARMING TREND WITH HIGH TEMPS RETURNING TO NEAR NORMAL READINGS IN THE LOWER TO MID 70S. OVERNIGHT LOWS WILL ALSO MODERATE TO NEAR OR ABOVE NORMAL READINGS...RANGING FROM THE LOWER TO MID 50S WEDNESDAY NIGHT TO THE MID AND UPPER 50S THURSDAY NIGHT AND FRIDAY NIGHT. THE RETURN OF WARMTH WILL ALSO BRING A RETURN OF HUMIDITY AND A FAIR CHANCE OF RAIN FROM THURSDAY THROUGH SATURDAY. PRECIPITABLE WATER VALUES WILL INCREASE FROM AROUND A HALF INCH AT MID WEEK TO MORE THEN AN INCH AND A HALF BY THE END OF THE WEEK...THUS WE CAN EXPECT THE POSSIBILITY OF DOWNPOURS ASSOCIATED WITH ANY CONVECTION. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... OUTSIDE OF LOCALLY LOWER CONDITIONS IN SHOWERS AND THUNDERSTORMS EXPECT PREDOMINANTLY VFR CONDITIONS TONIGHT. SHOWERS AND THUNDERSTORMS SHOULD BECOME MORE WIDESPREAD LATE TONIGHT...AS AN AREA OF ORGANIZED CONVECTION IS LIKELY TO TRACK FROM WEST TO EAST LATE TONIGHT AND INTO SUNDAY MORNING. EXPECT THINGS TO CLEAR OUT BEHIND THIS...WITH A RETURN TO VFR CONDITIONS. A COLD FRONT WILL CROSS TOWARD 00Z...WITH WIND SHIFT AND PERHAPS A FEW SHOWERS. OUTLOOK... SUNDAY NIGHT...MAINLY VFR. A CHANCE OF SHOWERS. MONDAY THROUGH WEDNESDAY...VFR. THURSDAY...MAINLY VFR. A CHANCE OF THUNDERSTORMS. && .MARINE... AN AREA OF LOW PRESSURE WILL PASS BY TO THE NORTH OF THE REGION SUNDAY WITH A COLD FRONT CROSSING THE LOWER LAKES. WINDS WILL INCREASE OUT OF THE SOUTHWEST ALONG AND BEHIND THIS COLD FRONT WITH THE POTENTIAL FOR A PERIOD OF WINDS AND WAVES APPROACHING SMALL CRAFT ADVISORY CRITERIA. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...APFFEL NEAR TERM...APFFEL/LEVAN SHORT TERM...WCH LONG TERM...WCH AVIATION...APFFEL/LEVAN MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
815 PM EDT SAT JUN 1 2013 .SYNOPSIS... A COLD FRONT WILL GRADUALLY APPROACH FROM THE UPPER LAKES TONIGHT...CROSSING THE REGION LATE ON SUNDAY. THIS WILL BRING AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS TONIGHT INTO SUNDAY...WITH LOCALLY HEAVY DOWNPOURS POSSIBLE. COOLER AND DRIER AIR WILL BUILD INTO THE REGION FOR THE FIRST HALF OF THE WEEK. && .NEAR TERM /THROUGH SUNDAY/... THROUGH THIS EVENING...SHOWERS AND THUNDERSTORMS EXTEND ALONG A BOUNDARY WHICH EXTENDS FROM WESTERN PORTIONS OF THE SOUTHERN TIER TO EASTERN LAKE ONTARIO. THIS LINE CAN BE SEEN ON IR SATELLITE IMAGERY...AND IS FORECAST TO CONTINUE TO SLIDE EASTWARD. WIND PROFILES SHOW A FAIR AMOUNT OF SHEAR...WITH 850 MB WINDS INCREASING TO 40 KTS. STORMS HAVE DEVELOPED INTO LINEAR BOWING SEGMENTS...A COUPLE STRONG INDIVIDUAL CELLS. WITH THE LOSS OF DAYTIME HEATING AND FOLLOWING AN INITIAL ROUND OF CONVECTION...THE CHANCE FOR WINDS TO MIX DOWN IS DIMINISHED FROM EARLIER TODAY. WHILE STORMS STILL BEAR WATCHING...EXPECT THE SEVERE WEATHER POTENTIAL TO DIMINISH THROUGH LATE EVENING. FORECAST CONFIDENCE INCREASES LATER TONIGHT...DUE TO A STRONGER MODEL CONSENSUS. WITH THE HRRR ALSO LENDING SUPPORT THE OTHER GUIDANCE (NAM/RGEM/SREF/GFS)...THERE IS A HIGH CONFIDENCE IN SHOWERS AND THUNDERSTORMS MOVING IN FROM WEST TO EAST LATE TONIGHT AS AN UPPER TROF GETS CLOSER. A STRONG MODEL CONSENSUS SHOWS SOME MEASURABLE QPF IN WESTERN SECTIONS BY DAYBREAK SUNDAY...AND GIVEN THE SYNOPTIC FEATURE THIS MAKES SENSE. LATER TONIGHT...THERE IS A POTENTIAL FOR HEAVY RAIN...WITH PWATS FORECAST TO INCREASE TO 1.75 INCHES BY BOTH THE NAM/GFS. TEMPERATURES SHOULD ONLY DROP INTO THE UPPER 60S OVERNIGHT...AS WINDS/CLOUDS AND RAIN LIMIT RADIATIONAL COOLING. HIGHS ON SUNDAY SHOULD BE NOTABLY COOLER..RANGING FROM THE 70S IN WESTERN SECTIONS TO LOWER 80S ACROSS THE GENESEE VALLEY AND FINGER LAKES REGIONS. SHOWERS AND THUNDERSTORMS SHOULD TAPER OFF FROM WEST TO EAST ON SUNDAY. THIS ACTIVITY IS LIKELY TO BE ALONG A PRE-FRONTAL TROF...WITH THE ACTUAL FRONT AND WIND SHIFT LIKELY TO HOLD OFF UNTIL LATER IN THE DAY. THIS MAY SPARK AN ADDITIONAL SHOWER...WITH A SIGNIFICANT BREAK OF FAIR WEATHER POSSIBLE BETWEEN THE PRE-FRONTAL TROF AND THE FRONT ITSELF. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... THE CLOSED UPPER LOW OVER ONTARIO PROVINCE BETWEEN THE NORTHERN GREAT LAKES AND JAMES BAY WILL MOVE EAST SUNDAY NIGHT AS A POSTFRONTAL SURFACE RIDGE BUILDS ACROSS NEW YORK STATE. THIS WILL CLEAR OUT LOW LEVEL DEWPOINTS FROM THE UPPER 50S TO 60 DEGREES SUNDAY EVENING...TO THE MID 40S TO LOW 50S BY DAYBREAK ON MONDAY. THERE WILL ALSO BE A CLEARING TREND WITH THE INFLUX OF THE DRIER AIRMASS AND COLD ADVECTION WILL BRING OVERNIGHT LOWS TO THE UPPER 40S TO LOW 50S. SURFACE HIGH PRESSURE CENTER OVER SOUTHERN ONTARIO PROVINCE WILL PROVIDE A DRY AND COOL PERIOD FOR THE FIRST HALF OF THE WEEK WITH POPS NEAR ZERO AND ABUNDANT SUNSHINE. HIGH TEMPS WILL BE IN THE LOWER TO MIDDLE 60S AT THE START OF THE WEEK AND NUDGE UP TO THE MID AND UPPER 60S ON TUESDAY. DRY AIR AND CLEAR SKIES AT NIGHT WILL ALLOW LOW TEMPS TO FALL TO THE LOWER TO MID 40S FOR MOST OF THE AREA MONDAY NIGHT AND MOSTLY IN THE MID TO UPPER 40S FOR TUESDAY NIGHT. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... THE CENTER OF THE SURFACE HIGH ACROSS SOUTHERN ONTARIO WILL MOVE EASTWARD AND ALLOW A SOUTHERLY FLOW ACROSS THE FORECAST AREA. THIS WILL BRING A MIDWEEK WARMING TREND WITH HIGH TEMPS RETURNING TO NEAR NORMAL READINGS IN THE LOWER TO MID 70S. OVERNIGHT LOWS WILL ALSO MODERATE TO NEAR OR ABOVE NORMAL READINGS...RANGING FROM THE LOWER TO MID 50S WEDNESDAY NIGHT TO THE MID AND UPPER 50S THURSDAY NIGHT AND FRIDAY NIGHT. THE RETURN OF WARMTH WILL ALSO BRING A RETURN OF HUMIDITY AND A FAIR CHANCE OF RAIN FROM THURSDAY THROUGH SATURDAY. PRECIPITABLE WATER VALUES WILL INCREASE FROM AROUND A HALF INCH AT MID WEEK TO MORE THEN AN INCH AND A HALF BY THE END OF THE WEEK...THUS WE CAN EXPECT THE POSSIBILITY OF DOWNPOURS ASSOCIATED WITH ANY CONVECTION. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... EXPECT THE MAJORITY OF THIS EVENING TO BE VFR...OUTSIDE OF LOCALLY LOWER CONDITIONS IN SHOWERS AND THUNDERSTORMS. THESE SHOULD INITIALLY TAPER OFF...BUT THEN BECOME MORE WIDESPREAD LATE TONIGHT...AS AN AREA OF ORGANIZED CONVECTION IS LIKELY TO TRACK FROM WEST TO EAST LATE TONIGHT AND INTO SUNDAY MORNING. EXPECT THINGS TO CLEAR OUT BEHIND THIS...WITH A RETURN TO VFR CONDITIONS. A COLD FRONT WILL CROSS TOWARD 00Z...WITH WIND SHIFT AND PERHAPS A FEW SHOWERS. OUTLOOK... SUNDAY NIGHT...MAINLY VFR. A CHANCE OF SHOWERS. MONDAY THROUGH WEDNESDAY...VFR. THURSDAY...MAINLY VFR. A CHANCE OF THUNDERSTORMS. && .MARINE... AN AREA OF LOW PRESSURE WILL PASS BY TO THE NORTH OF THE REGION SUNDAY WITH A COLD FRONT CROSSING THE LOWER LAKES. WINDS WILL INCREASE OUT OF THE SOUTHWEST ALONG AND BEHIND THIS COLD FRONT WITH THE POTENTIAL FOR A PERIOD OF WINDS AND WAVES APPROACHING SMALL CRAFT ADVISORY CRITERIA. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...APFFEL NEAR TERM...APFFEL SHORT TERM...WCH LONG TERM...WCH AVIATION...APFFEL MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
515 PM EDT FRI MAY 31 2013 .SYNOPSIS... A HOT AND HUMID AIRMASS WILL REMAIN IN PLACE THROUGH THE FIRST HALF OF THE WEEKEND WITH AT LEAST SCATTERED SHOWERS THUNDERSTORMS TONIGHT AND SATURDAY. THE HIGHEST THREAT FOR RAINFALL WILL BE LATER SATURDAY NIGHT AND SUNDAY AS A COLD FRONT CROSSES THE REGION. THIS FRONT WILL USHER IN A COOLER AND DRIER AIRMASS FOR THE FIRST HALF OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AN UPPER LEVEL RIDGE IS OFF THE EAST COAST WITH MOISTURE BEING ADVECTED ACROSS THE OHIO VALLEY TOWARD NY. SCATTERED CONVECTION OVER CENTRAL OH MATCHES 00Z SSEO NICELY WHILE EACH CONSECUTIVE RUN OF THE HRRR SEEMS TO BE MISSING THE LEADING LINE. SO BASED OFF THE 00Z SSEO AND TO SOME EXTENT THE 12Z NAM...BUT PRIMARILY SATELLITE/OBSERVATION EXTRAPOLATION...EXPECT A FAIRLY DISORGANIZED LINE OF THUNDERSTORMS TO DEVELOP LATER THIS AFTERNOON AND WORK ITS WAY INTO THE SOUTHERN TIER AND THEN NIAGARA FRONTIER EARLY THIS EVENING...BEFORE WEAKENING OR COMPLETELY FALLING APART OVER THE GENESEE VALLEY/FINGER LAKES REGION. THIS WILL LEAVE QUITE A BIT OF CLOUD COVER OVER THE REGION...AND THUS EXPECT LOWS TO GET STUCK IN THE UPPER 60S TO NEAR 70 FOR MOST LOCATIONS...A BIT ABOVE MOST GUIDANCE. EXTENSIVE CLOUD COVER WILL CONTINUE INTO SATURDAY IN THE MOIST AND UNSTABLE ATMOSPHERE. THIS WILL LIMIT DAYTIME HIGHS FROM GETTING TOO HIGH...WITH MOST AREAS IN THE LOW TO MID 80S. THE CLOUD COVER WILL ALSO PREVENT WIDESPREAD CONVECTION. INSTEAD...EXPECT HIT/MISS SHOWERS TO DEVELOP. INITIATION AND EVENTUAL LOCATION WILL BE NEARLY IMPOSSIBLE TO PINPOINT AS BOTH LOCAL MESOSCALE BOUNDARIES /LAKE BREEZES/ AND GENERAL SYNOPTIC SCALE LIFT MAY FORCE THUNDERSTORM DEVELOPMENT. WILL SLOWLY INCREASE THE PROBABILITY OF PRECIPITATION INTO THE AFTERNOON...WITH INCREASING PRECIPITABLE WATER...INSTABILITY AND THE APPROACHING COLD FRONT CREATING A BETTER CHANCE FOR CONVECTION WITH TIME. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... IT WILL BE A WARM AND HUMID NIGHT ON SATURDAY NIGHT WITH OVERNIGHT LOW TEMPS IN THE UPPER 60S ACROSS THE HIGHLANDS OF THE SOUTHERN TIER AND THE TUG HILL PLATEAU WITH LOWER 70S FOR THE LAKE PLAINS AND URBAN AREAS. IT WILL ALSO BECOME RATHER BREEZY WITH THE TIGHTENING PRESSURE GRADIENT AHEAD OF THE APPROACHING COLD FRONT...WHICH WILL HELP TO HOLD THE TEMPS UP THROUGH THE NIGHT. PRECIP WILL PRECEDE THE COLD FRONT WITH THE 40 KNOT 850MB JET FEEDING THE CONVECTION AND PROVIDING LOW LEVEL CONVERGENCE. PRECIPITABLE WATER VALUES INCREASE TO NEARLY ONE AND THREE QUARTERS OF AN INCH WITH HIGH PRECIP EFFICIENCY AND INDICATIONS OF TRAINING STORMS ALONG THE FRONT. WILL CARRY CATEGORICAL POPS SATURDAY NIGHT THROUGH SUNDAY AS THE FRONT AND PRECEDENT PRECIP CROSS THE REGION. TEMPS ON SUNDAY WILL BE IN THE MID 70S TO LOW 80S...LIMITED BY THE PRECIP AND THE PASSAGE OF THE COLD FRONT. PRECIP SHOULD TAPER OFF QUICKLY WITH THE FRONTAL PASSAGE WITH ONLY SCATTERED SHOWERS TRAILING THE FRONT. SKIES WILL START TO CLEAR ON MONDAY AS HIGH PRESSURE NOSES IN FROM THE WEST WITH MUCH COOLER TEMPS IN THE MID TO UPPER 60S...THEN CLEARING AND VERY COOLER MONDAY NIGHT WITH LOWS IN THE 40S. && .LONG TERM /TUESDAY THROUGH FRIDAY/... COOLER CANADIAN HIGH PRESSURE ACROSS SOUTHERN ONTARIO WILL RESULT IN SUNNY SKIES AND COOLER THAN NORMAL TEMPERATURES...THE COOLEST TEMPS ON TUESDAY THEN A WARMING TREND THROUGH THE WEEK. MEANWHILE...WE CAN ANTICIPATE GENERALLY RAINFREE WEATHER FOR TUESDAY THROUGH WEDNESDAY NIGHT. AN UPPER LOW PASSING EASTWARD ACROSS WESTERN ONTARIO WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY AS A WARMER AND INCREASINGLY MORE HUMID SOUTHERLY FLOW DEVELOPS. PRECIPITABLE WATER VALUES WILL INCREASE FROM AROUND A HALF INCH AT MID WEEK TO MORE THEN AN INCH AND A HALF BY THE END OF THE WEEK. TEMPS WILL CLIMB FROM THE 60S ON TUESDAY TO THE LOWER TO MID 70S ON WEDNESDAY...AND THE MID 70S ON THURSDAY AND FRIDAY. OVERNIGHT LOW TEMPS WILL ALSO RETURN TO A NEARLY NORMAL TREND WITH 40S TUESDAY NIGHT TEMPERING TO THE LOWER TO MID 50S THURSDAY NIGHT...EVEN SOME UPPER 50S POSSIBLE. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS EXPECTED THROUGH 18Z SATURDAY...ALBEIT WITH A FEW ROUNDS OF CONVECTION. THE FIRST WEAKLY ORGANIZED AREA LIFTING ACROSS OHIO AND EXPECT IT TO WORK ITS WAY INTO WESTERN NY BEFORE WEAKENING AND/OR FALLING APART OVERNIGHT AS IT MOVES INTO THE FINGER LAKES/GENESEE VALLEY REGION. LOCAL MVFR IS POSSIBLE WITH THIS...BUT FOR NOW WILL KEEP ALL TAFS VFR WITHOUT AN MENTION OF TS. CONVECTION ON SATURDAY SHOULD IN GENERAL HOLD OFF UNTIL AFTER 18Z...ALTHOUGH SOME SHOWER DEVELOPMENT IS POSSIBLE OVER FAR WESTERN NY BEFORE THAT TIME. MOST OF THE CONVECTION AND PRECIPITATION IS EXPECTED LATE SATURDAY EVENING/OVERNIGHT AS A COLD FRONT MOVES ACROSS THE REGION. OUTLOOK... SUNDAY...VFR MUCH OF THE TIME...BUT OCCASIONAL SHOWERS AND THUNDERSTORMS WILL PRODUCE LOCAL MVFR/IFR AT TIMES. MONDAY-WEDNESDAY...VFR. && .MARINE... RELATIVELY LIGHT WINDS WILL CONTINUE THROUGH SATURDAY AS A GENERAL SOUTH TO SOUTHWEST FLOW REMAINS IN PLACE AROUND A BERMUDA HIGH PARKED OFF THE SOUTHEAST COAST. STRONG DIFFERENTIAL HEATING AND RELATIVELY LIGHT SYNOPTIC SCALE FLOW WILL ALLOW LOCAL LAKE BREEZES TO DEVELOP SATURDAY AFTERNOON...MAINLY ON THE EAST HALF OF LAKE ONTARIO WITH WINDS BECOMING LOCALLY ONSHORE. AN AREA OF LOW PRESSURE WILL PASS BY TO THE NORTH OF THE REGION SUNDAY WITH A COLD FRONT CROSSING THE LOWER LAKES. WINDS WILL INCREASE OUT OF THE SOUTHWEST ALONG AND BEHIND THIS COLD FRONT... WITH CONDITIONS REACHING SMALL CRAFT ADVISORY CRITERIA. && .CLIMATE... RECORD HIGH FOR WATERTOWN TIED TODAY. 88 DEGREES SET IN 2010. E && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...ZAFF NEAR TERM...LEVAN/ZAFF SHORT TERM...WCH LONG TERM...WCH AVIATION...LEVAN/ZAFF MARINE...ZAFF CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
252 PM EDT FRI MAY 31 2013 .SYNOPSIS... A HOT AND HUMID AIRMASS WILL REMAIN IN PLACE THROUGH THE FIRST HALF OF THE WEEKEND WITH AT LEAST SCATTERED SHOWERS THUNDERSTORMS TONIGHT AND SATURDAY. THE HIGHEST THREAT FOR RAINFALL WILL BE LATER SATURDAY NIGHT AND SUNDAY AS A COLD FRONT CROSSES THE REGION. THIS FRONT WILL USHER IN A COOLER AND DRIER AIRMASS FOR THE FIRST HALF OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AN UPPER LEVEL RIDGE IS OFF THE EAST COAST THIS AFTERNOON WITH MOISTURE BEING ADVECTED ACROSS THE OHIO VALLEY TOWARD NY. SCATTERED CONVECTION FORMING OVER CENTRAL OH MATCHES 00Z SSEO NICELY WHILE EACH CONSECUTIVE RUN OF THE HRRR SEEMS TO BE MISSING THE LEADING LINE. SO BASED OFF THE 00Z SSEO AND TO SOME EXTENT THE 12Z NAM...BUT PRIMARILY SATELLITE/OBSERVATION EXTRAPOLATION...EXPECT A FAIRLY DISORGANIZED LINE OF THUNDERSTORMS TO DEVELOP LATER THIS AFTERNOON AND WORK ITS WAY INTO THE SOUTHERN TIER AND THEN NIAGARA FRONTIER EARLY THIS EVENING...BEFORE WEAKENING OR COMPLETELY FALLING APART OVER THE GENESEE VALLEY/FINGER LAKES REGION. THIS WILL LEAVE QUITE A BIT OF CLOUD COVER OVER THE REGION...AND THUS EXPECT LOWS TO GET STUCK IN THE UPPER 60S TO NEAR 70 FOR MOST LOCATIONS...A BIT ABOVE MOST GUIDANCE. EXTENSIVE CLOUD COVER WILL CONTINUE INTO SATURDAY IN THE MOIST AND UNSTABLE ATMOSPHERE. THIS WILL LIMIT DAYTIME HIGHS FROM GETTING TOO HIGH...WITH MOST AREAS IN THE LOW TO MID 80S. THE CLOUD COVER WILL ALSO PREVENT WIDESPREAD CONVECTION. INSTEAD...EXPECT HIT/MISS SHOWERS TO DEVELOP. INITIATION AND EVENTUAL LOCATION WILL BE NEARLY IMPOSSIBLE TO PINPOINT AS BOTH LOCAL MESOSCALE BOUNDARIES /LAKE BREEZES/ AND GENERAL SYNOPTIC SCALE LIFT MAY FORCE THUNDERSTORM DEVELOPMENT. WILL SLOWLY INCREASE THE PROBABILITY OF PRECIPITATION INTO THE AFTERNOON...WITH INCREASING PRECIPITABLE WATER...INSTABILITY AND THE APPROACHING COLD FRONT CREATING A BETTER CHANCE FOR CONVECTION WITH TIME. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... IT WILL BE A WARM AND HUMID NIGHT ON SATURDAY NIGHT WITH OVERNIGHT LOW TEMPS IN THE UPPER 60S ACROSS THE HIGHLANDS OF THE SOUTHERN TIER AND THE TUG HILL PLATEAU WITH LOWER 70S FOR THE LAKE PLAINS AND URBAN AREAS. IT WILL ALSO BECOME RATHER BREEZY WITH THE TIGHTENING PRESSURE GRADIENT AHEAD OF THE APPROACHING COLD FRONT...WHICH WILL HELP TO HOLD THE TEMPS UP THROUGH THE NIGHT. PRECIP WILL PRECEDE THE COLD FRONT WITH THE 40 KNOT 850MB JET FEEDING THE CONVECTION AND PROVIDING LOW LEVEL CONVERGENCE. PRECIPITABLE WATER VALUES INCREASE TO NEARLY ONE AND THREE QUARTERS OF AN INCH WITH HIGH PRECIP EFFICIENCY AND INDICATIONS OF TRAINING STORMS ALONG THE FRONT. WILL CARRY CATEGORICAL POPS SATURDAY NIGHT THROUGH SUNDAY AS THE FRONT AND PRECEDENT PRECIP CROSS THE REGION. TEMPS ON SUNDAY WILL BE IN THE MID 70S TO LOW 80S...LIMITED BY THE PRECIP AND THE PASSAGE OF THE COLD FRONT. PRECIP SHOULD TAPER OFF QUICKLY WITH THE FRONTAL PASSAGE WITH ONLY SCATTERED SHOWERS TRAILING THE FRONT. SKIES WILL START TO CLEAR ON MONDAY AS HIGH PRESSURE NOSES IN FROM THE WEST WITH MUCH COOLER TEMPS IN THE MID TO UPPER 60S...THEN CLEARING AND VERY COOLER MONDAY NIGHT WITH LOWS IN THE 40S. && .LONG TERM /TUESDAY THROUGH FRIDAY/... COOLER CANADIAN HIGH PRESSURE ACROSS SOUTHERN ONTARIO WILL RESULT IN SUNNY SKIES AND COOLER THAN NORMAL TEMPERATURES...THE COOLEST TEMPS ON TUESDAY THEN A WARMING TREND THROUGH THE WEEK. MEANWHILE...WE CAN ANTICIPATE GENERALLY RAINFREE WEATHER FOR TUESDAY THROUGH WEDNESDAY NIGHT. AN UPPER LOW PASSING EASTWARD ACROSS WESTERN ONTARIO WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY AS A WARMER AND INCREASINGLY MORE HUMID SOUTHERLY FLOW DEVELOPS. PRECIPITABLE WATER VALUES WILL INCREASE FROM AROUND A HALF INCH AT MID WEEK TO MORE THEN AN INCH AND A HALF BY THE END OF THE WEEK. TEMPS WILL CLIMB FROM THE 60S ON TUESDAY TO THE LOWER TO MID 70S ON WEDNESDAY...AND THE MID 70S ON THURSDAY AND FRIDAY. OVERNIGHT LOW TEMPS WILL ALSO RETURN TO A NEARLY NORMAL TREND WITH 40S TUESDAY NIGHT TEMPERING TO THE LOWER TO MID 50S THURSDAY NIGHT...EVEN SOME UPPER 50S POSSIBLE. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS EXPECTED THROUGH 18Z SATURDAY...ALBEIT WITH A FEW ROUNDS OF CONVECTION. THE FIRST WEAKLY ORGANIZED AREA IS FORMING OVER OH...AND EXPECT IT TO WORK ITS WAY INTO WESTERN NY BEFORE WEAKENING AND/OR FALLING APART OVERNIGHT AS IT MOVES INTO THE FINGER LAKES/GENESEE VALLEY REGION. LOCAL MVFR IS POSSIBLE WITH THIS...BUT FOR NOW WILL KEEP ALL TAFS VFR WITHOUT AN MENTION OF TS. CONVECTION ON SATURDAY SHOULD IN GENERAL HOLD OFF UNTIL AFTER 18Z...ALTHOUGH SOME SHOWER DEVELOPMENT IS POSSIBLE OVER FAR WESTERN NY BEFORE THAT TIME. MOST OF THE CONVECTION AND PRECIPITATION IS EXPECTED LATE SATURDAY EVENING/OVERNIGHT AS A COLD FRONT MOVES ACROSS THE REGION. OUTLOOK... SUNDAY...VFR MUCH OF THE TIME...BUT OCCASIONAL SHOWERS AND THUNDERSTORMS WILL PRODUCE LOCAL MVFR/IFR AT TIMES. MONDAY-WEDNESDAY...VFR. && .MARINE... RELATIVELY LIGHT WINDS WILL CONTINUE THROUGH SATURDAY AS A GENERAL SOUTH TO SOUTHWEST FLOW REMAINS IN PLACE AROUND A BERMUDA HIGH PARKED OFF THE SOUTHEAST COAST. STRONG DIFFERENTIAL HEATING AND RELATIVELY LIGHT SYNOPTIC SCALE FLOW WILL ALLOW LOCAL LAKE BREEZES TO DEVELOP SATURDAY AFTERNOON...MAINLY ON THE EAST HALF OF LAKE ONTARIO WITH WINDS BECOMING LOCALLY ONSHORE. AN AREA OF LOW PRESSURE WILL PASS BY TO THE NORTH OF THE REGION SUNDAY WITH A COLD FRONT CROSSING THE LOWER LAKES. WINDS WILL INCREASE OUT OF THE SOUTHWEST ALONG AND BEHIND THIS COLD FRONT... WITH CONDITIONS REACHING SMALL CRAFT ADVISORY CRITERIA. && .CLIMATE... EARLY SEASON HEAT WILL CONTINUE TODAY. RECORD HIGHS FOR MAY 31 ARE 90 AT BUFFALO SET IN 1919...91 IN ROCHESTER SET IN 2011...AND 88 IN WATERTOWN SET IN 2010. AT BUFFALO...A SOUTHWEST FLOW OFF LAKE ERIE WILL KEEP TEMPS WELL SHY OF THE RECORD. BOTH ROCHESTER AND WATERTOWN WILL GET VERY CLOSE...WITH CURRENT FORECAST HIGHS WITHIN A DEGREE OR SO OF THE RECORDS. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...HITCHCOCK/ZAFF NEAR TERM...ZAFF SHORT TERM...WCH LONG TERM...WCH AVIATION...ZAFF MARINE...HITCHCOCK/ZAFF CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
200 PM EDT FRI MAY 31 2013 .SYNOPSIS... A HOT AND HUMID AIRMASS WILL REMAIN IN PLACE THROUGH THE FIRST HALF OF THE WEEKEND WITH AT LEAST SCATTERED SHOWERS THUNDERSTORMS TONIGHT AND SATURDAY. THE HIGHEST THREAT FOR RAINFALL WILL BE LATER SATURDAY NIGHT AND SUNDAY AS A COLD FRONT CROSSES THE REGION. THIS FRONT WILL USHER IN A COOLER AND DRIER AIRMASS FOR THE FIRST HALF OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AN UPPER LEVEL RIDGE IS OFF THE EAST COAST THIS AFTERNOON WITH MOISTURE BEING ADVECTED ACROSS THE OHIO VALLEY TOWARD NY. SCATTERED CONVECTION FORMING OVER CENTRAL OH MATCHES 00Z SSEO NICELY WHILE EACH CONSECUTIVE RUN OF THE HRRR SEEMS TO BE MISSING THE LEADING LINE. SO BASED OFF THE 00Z SSEO AND TO SOME EXTENT THE 12Z NAM...BUT PRIMARILY SATELLITE/OBSERVATION EXTRAPOLATION...EXPECT A FAIRLY DISORGANIZED LINE OF THUNDERSTORMS TO DEVELOP LATER THIS AFTERNOON AND WORK ITS WAY INTO THE SOUTHERN TIER AND THEN NIAGARA FRONTIER EARLY THIS EVENING...BEFORE WEAKENING OR COMPLETELY FALLING APART OVER THE GENESEE VALLEY/FINGER LAKES REGION. THIS WILL LEAVE QUITE A BIT OF CLOUD COVER OVER THE REGION...AND THUS EXPECT LOWS TO GET STUCK IN THE UPPER 60S TO NEAR 70 FOR MOST LOCATIONS...A BIT ABOVE MOST GUIDANCE. EXTENSIVE CLOUD COVER WILL CONTINUE INTO SATURDAY IN THE MOIST AND UNSTABLE ATMOSPHERE. THIS WILL LIMIT DAYTIME HIGHS FROM GETTING TOO HIGH...WITH MOST AREAS IN THE LOW TO MID 80S. THE CLOUD COVER WILL ALSO PREVENT WIDESPREAD CONVECTION. INSTEAD...EXPECT HIT/MISS SHOWERS TO DEVELOP. INITIATION AND EVENTUAL LOCATION WILL BE NEARLY IMPOSSIBLE TO PINPOINT AS BOTH LOCAL MESOSCALE BOUNDARIES /LAKE BREEZES/ AND GENERAL SYNOPTIC SCALE LIFT MAY FORCE THUNDERSTORM DEVELOPMENT. WILL SLOWLY INCREASE THE PROBABILITY OF PRECIPITATION INTO THE AFTERNOON...WITH INCREASING PRECIPITABLE WATER...INSTABILITY AND THE APPROACHING COLD FRONT CREATING A BETTER CHANCE FOR CONVECTION WITH TIME. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... VERY WARM AND SOMEWHAT HUMID CONDITIONS WILL PREVAIL ON SATURDAY AS THE DEEP LAYERED SOUTHWEST FLOW AROUND THE BERMUDA HIGH REMAINS IN CONTROL. HOWEVER...THERE WILL BE A BETTER CHANCE FOR SOME CONVECTION AS THE APPROACHING UPPER MIDWEST TROUGH BEGINS TO ERODE THE EASTERN UPPER LEVEL RIDGE AND ALLOWS SOME OF THE UPSTREAM CONVECTION TO ADVECT EAST ACROSS OUR CWA. IN ADDITION...OUR AREA WILL COME UNDER THE INFLUENCE OF ADDITIONAL LIFT FROM A JET STREAK THAT WILL BE ARCING FROM THE CENTRAL GREAT LAKES TO SOUTHERN QUEBEC. WILL MAINTAIN CHANCE POPS FOR MEASURABLE PCPN SINCE THE BEST DYNAMICS ASSOCIATED WITH THE UPPER TROUGH AND LOW LEVEL MOISTURE CONVERGENCE ARE FORECAST TO STAY TO OUR WEST. RIGHT NOW IT LOOKS LIKE MOST CONVECTION WILL STAY BELOW SEVERE LEVELS WITH INCREASING CLOUD COVER EXPECTED TO LIMIT INSTABILITY. THE AFOREMENTIONED UPPER LEVEL JET DYNAMICS WILL REMAIN IN PLACE SATURDAY NIGHT...WHILE A 50 KNOT LOW LEVEL JET HEADS EAST INTO WESTERN NEW YORK IN ADVANCE OF THE COLD FRONT THAT WILL BE WORKING EAST TOWARD THE LOWER GREAT LAKES. THE IMPROVING LARGE SCALE LIFT WILL SUPPORT MORE WIDESPREAD SHOWERS AND THUNDERSTORMS... ...PARTICULARLY OVER OUR WESTERN COUNTIES. FORECAST PWAT VALUES IN EXCESS OF 1.5 INCHES WILL LEAD TO A HIGHER POTENTIAL FOR LOCALLY HEAVY RAIN IN ANY CONVECTION. THE DEEP SOUTHERLY FLOW AHEAD OF THE FRONT WILL MAKE THIS THE WARMEST NIGHT WITH MANY LOCATIONS ALONG THE LAKE PLAINS STRUGGLING TO DROP BELOW 70 DEGREES. THE SURFACE LOW THAT IS ASSOCIATED WITH THE APPROACHING UPPER LEVEL TROUGH WILL TRACK NORTH OF NEW YORK STATE ON SUNDAY AND SWEEP THE FIRST OF TWO COLD FRONTS ACROSS THE WESTERN COUNTIES DURING THE MORNING...AND ACROSS THE EASTERN LAKE ONTARIO REGION DURING THE MIDDAY. THIS TIMING OF THE FRONTAL PASSAGE WILL SHORTEN THE DURATION OF WIDESPREAD PCPN...WHILE LIKELY REDUCING THE THREAT FOR SEVERE CONVECTION. HOWEVER...PWAT VALUES >1.5 INCHES SHOULD STILL PROMOTE HEAVY RAINS THROUGH MIDDAY. A DRY SLOT WILL WORK IN BEHIND THE COLD FRONT...HELPING TO REDUCE THE POPS TO LOW CHANCE. TEMPERATURES SUNDAY AFTERNOON WILL GENERALLY BE IN THE 70S. WHEN THE SECONDARY COLD FRONT CROSSES WESTERN AND CENTRAL NEW YORK SUNDAY EVENING...THE DEEPEST MOISTURE ASSOCIATED WITH THE FIRST FRONT WILL HAVE MOVED EAST OF OUR AREA. AS A RESULT...EXPECT MAINLY DRY CONDITIONS TO PREVAIL WITH THIS FRONT. OF GREATER NOTE...IT WILL TURN COOLER AND LESS HUMID WITH EARLY MORNING TEMPERATURES COOLING INTO THE LOWER TO MID 50S...RIGHT WHERE THEY SHOULD BE AT THIS POINT IN THE SEASON. && .LONG TERM /MONDAY THROUGH THURSDAY/... A LOW AMPLITUDE FLOW ACROSS THE COUNTRY DURING THIS PERIOD WILL RESULT IN NEAR TO BELOW NORMAL TEMPERATURES...WITH THE COOLEST CONDITIONS COMING AT THE START OF THE NEW WORK WEEK. MEANWHILE...WE CAN ANTICIPATE GENERALLY RAINFREE WEATHER. THE BASE OF A DIGGING H5 TROUGH WILL SWING ACROSS TO THE NORTH OF LK ONTARIO ON MONDAY. LOW LEVEL RIDGING AND A WEALTH OF DRY AIR UNDER THIS APPROACHING TROUGH SHOULD DISCOURAGE ANY PCPN...BUT WILL KEEP SLGT CHC POPS IN PLACE ACROSS THE NORTH COUNTRY WHERE HGT FALLS WILL BE THE MOST SIGNIFICANT. OUTSIDE OF THIS LONE `FLY IN THE OINTMENT`...MONDAY SHOULD BE PARTLY TO MOSTLY SUNNY AND SEASONABLY COOL WITH AFTERNOON TEMPERATURES IN THE 60S. HIGH PRESSURE CENTERED OVER JAMES BAY WILL THEN NOSE SOUTH ACROSS THE LOWER GREAT LAKES MONDAY NIGHT THROUGH WEDNESDAY...WITH H85 TEMPS GENERALLY IN THE UPPER SINGLE DIGITS. THIS WILL KEEP PLEASANTLY COOL CONDITIONS IN PLACE A BIT LONGER...BUT TEMPERATURES WILL MODERATE DURING THE SECOND HALF OF THE WEEK. THE AFOREMENTIONED SFC HIGH WILL MOVE TO THE CANADIAN MARITIMES WEDNESDAY NIGHT AND THURSDAY WHILE A SHORTWAVE WILL DIG ACROSS THE NORTHERN PLAINS. THIS WILL SET UP A SOUTH TO SOUTHEAST FLOW OF MILDER AIR ACROSS OUR REGION...PROMOTING MILDER WEATHER WITH DAYTIME HIGHS CLIMBING BACK ABOVE NORMAL. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS EXPECTED THROUGH 18Z SATURDAY...ALBEIT WITH A FEW ROUNDS OF CONVECTION. THE FIRST WEAKLY ORGANIZED AREA IS FORMING OVER OH...AND EXPECT IT TO WORK ITS WAY INTO WESTERN NY BEFORE WEAKENING AND/OR FALLING APART OVERNIGHT AS IT MOVES INTO THE FINGER LAKES/GENESEE VALLEY REGION. LOCAL MVFR IS POSSIBLE WITH THIS...BUT FOR NOW WILL KEEP ALL TAFS VFR WITHOUT AN MENTION OF TS. CONVECTION ON SATURDAY SHOULD IN GENERAL HOLD OFF UNTIL AFTER 18Z...ALTHOUGH SOME SHOWER DEVELOPMENT IS POSSIBLE OVER FAR WESTERN NY BEFORE THAT TIME. MOST OF THE CONVECTION AND PRECIPITATION IS EXPECTED LATE SATURDAY EVENING/OVERNIGHT AS A COLD FRONT MOVES ACROSS THE REGION. OUTLOOK... SUNDAY...VFR MUCH OF THE TIME...BUT OCCASIONAL SHOWERS AND THUNDERSTORMS WILL PRODUCE LOCAL MVFR/IFR AT TIMES. MONDAY-WEDNESDAY...VFR. && .MARINE... RELATIVELY LIGHT WINDS WILL CONTINUE THROUGH SATURDAY AS A GENERAL SOUTH TO SOUTHWEST FLOW REMAINS IN PLACE AROUND A BERMUDA HIGH PARKED OFF THE SOUTHEAST COAST. STRONG DIFFERENTIAL HEATING AND RELATIVELY LIGHT SYNOPTIC SCALE FLOW WILL ALLOW LOCAL LAKE BREEZES TO DEVELOP SATURDAY AFTERNOON...MAINLY ON THE EAST HALF OF LAKE ONTARIO WITH WINDS BECOMING LOCALLY ONSHORE. AN AREA OF LOW PRESSURE WILL PASS BY TO THE NORTH OF THE REGION SUNDAY WITH A COLD FRONT CROSSING THE LOWER LAKES. WINDS WILL INCREASE OUT OF THE SOUTHWEST ALONG AND BEHIND THIS COLD FRONT... WITH CONDITIONS REACHING SMALL CRAFT ADVISORY CRITERIA. && .CLIMATE... EARLY SEASON HEAT WILL CONTINUE TODAY. RECORD HIGHS FOR MAY 31 ARE 90 AT BUFFALO SET IN 1919...91 IN ROCHESTER SET IN 2011...AND 88 IN WATERTOWN SET IN 2010. AT BUFFALO...A SOUTHWEST FLOW OFF LAKE ERIE WILL KEEP TEMPS WELL SHY OF THE RECORD. BOTH ROCHESTER AND WATERTOWN WILL GET VERY CLOSE...WITH CURRENT FORECAST HIGHS WITHIN A DEGREE OR SO OF THE RECORDS. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...HITCHCOCK/ZAFF NEAR TERM...ZAFF SHORT TERM...TJP LONG TERM...TJP AVIATION...ZAFF MARINE...HITCHCOCK/ZAFF CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
305 PM EDT FRI MAY 31 2013 .SYNOPSIS... BERMUDA HIGH PRESSURE WILL CONTINUE ACROSS THE CAROLINAS THROUGH THE WEEKEND. A COLD FRONT WILL SLOWLY MOVE THROUGH THE AREA EARLY NEXT WEEK...BRINGING THE HIGHEST POTENTIAL FOR SHOWERS AND THUNDERSTORMS MONDAY AND TUESDAY. HIGH PRESSURE WILL SLOWLY BUILD SOUTHWARD AND INTO THE AREA DURING THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM FRIDAY...BERMUDA HIGH PRESSURE WELL OFFSHORE EXTENDS INTO THE EASTERN CAROLINAS FROM A CENTER OVER 1000 MILES OFFSHORE. A LONG EASTERLY FETCH ACROSS THE CENTRAL ATLANTIC OCEAN IS BRINGING WARM AND HUMID AIR ONSHORE. SHOWERS HAVE BEEN MUCH MORE WIDESPREAD TODAY THAN YESTERDAY MAINLY DUE TO RICHER BOUNDARY LAYER MOISTURE EXISTING WITHIN AN UNCAPPED AND UNSTABLE ATMOSPHERE. THIS CONVECTIVE ACTIVITY IS TIED TO DAYTIME HEATING AND SHOULD QUICKLY DIMINISH THIS EVENING WITH MAINLY CLEAR SKIES DEVELOPING BY 8-10 PM. MUCH LIKE LAST NIGHT...HIGH DEWPOINTS WITHIN THE BOUNDARY LAYER AND LIGHT SURFACE WINDS SHOULD ALLOW LOW STRATUS AND FOG TO DEVELOP LATE TONIGHT...MAINLY ACROSS THE SAME AREAS AS LAST NIGHT. OVERNIGHT LOWS SHOULD RUN NEAR TO PERHAPS TWO DEGREES WARMER THAN LAST NIGHT... GENERALLY MID 60S MOST AREAS TO AROUND 70 ON THE BEACHES. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...HIGH PRESSURE WILL HOLD ON THROUGH THE WEEKEND AS IT SLOWLY SLIPS FARTHER EAST. THE STRONG RIDGE OF HIGH PRESSURE ALOFT WILL ALSO CONTINUE TO SHIFT EAST INTO THE ATLANTIC WHILE A DEEPENING TROUGH MOVES IN FROM THE CENTRAL CONUS. THIS TROUGH WILL PUSH A COLD FRONT EAST BUT WILL NOT REACH THE CAROLINAS UNTIL MONDAY MORNING. AS THE RIDGE SLIPS EAST WE WILL LOSE SOME OF OUR CAP ON CONVECTION AND SEE LOCALIZED SHWRS/TSTMS THROUGH THE WEEKEND. BY SUNDAY THE WINDS WILL BE INCREASING OUT OF THE SOUTH WHICH SHOULD PUSH SHWR DEVELOPMENT FARTHER WEST AND MAY SEE FEWER SHOWERS OVER LOCAL CWA THROUGH THE AFTN. OVERALL EXPECT A WARM AND HUMID SUMMER-LIKE AIR MASS TO REMAIN OVER THE AREA THROUGH MUCH OF THE WEEKEND. SOUTHERLY WINDS WILL PICK UP PRODUCING BREEZY WEATHER BY SUNDAY AFTERNOON. EXPECT CU TO BUILD EACH AFTERNOON WITH BEST CONVERGENCE AND CHC OF CONVECTION ALONG SEA BREEZE BOUNDARY AS IT PUSHES INLAND. A DEEPER MOISTER SOUTHERLY FLOW WILL INCREASE THE OVERALL MOISTURE THROUGH THE COLUMN BY THE END OF THE WEEKEND. PCP WATER VALUES WILL REACH UP TO 1.5 INCHES INLAND EACH AFTERNOON AS SHWRS/TSTMS FLARE UP BUT HEADING INTO LATE SUNDAY INTO SUNDAY NIGHT AHEAD OF COLD FRONT...VALUES WILL REACH UP CLOSER TO 2 INCHES. CLOUDS WILL INCREASE WITH SHOWERS AND THUNDERSTORMS INCREASING IN COVERAGE SUNDAY NIGHT INTO MONDAY AS COLD FRONT APPROACHES FROM THE WEST. THE WARM AND MOIST AIR MASS WILL CREATE MUCH LESS VARIATION IN DIURNAL TEMPERATURE SWINGS. OVERNIGHT LOWS WILL ONLY DROP TO THE MID 60S INLAND AND CLOSER TO 70 ALONG THE COAST. DAY TIME HIGHS WILL REACH THE MID TO UPPER 80S...EXCEPT COOLER ALONG THE BEACHES. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 PM FRIDAY...WHAT WILL LIKELY BEGIN AS A VERY WET START TO THE PERIOD WILL TRANSITION TO DRIER AND SEASONABLE CONDITIONS THROUGH MUCH OF THE UPCOMING WEEK. THERE IS QUITE A BIT OF UNCERTAINTY AT THE TAIL END OF THE PERIOD DUE TO INCREASED MOISTURE ASSOCIATED WITH A POTENTIAL TROPICAL SYSTEM IN THE GOM. BERMUDA HIGH PRESSURE WHICH HAS DOMINATED THE SYNOPTIC REGIME FOR MORE THAN WEEK NOW WILL FINALLY BE DISPLACED BY EARLY TUESDAY THANKS TO A COLD FRONT MOVING SLOWLY ACROSS THE SOUTHEAST. AHEAD OF THIS BOUNDARY...PWATS RISE TO NEARLY 2 INCHES...WHICH IS APPROACHING +2SD AND THE 99TH PERCENTILE FOR THE FIRST WEEK OF JUNE! THIS INCREDIBLY MOIST ENVIRONMENT PAIRED WITH CONVERGENCE ALONG THE FRONT...SOME DIFFLUENCE...ALBEIT RELATIVELY WEAK...WITHIN THE RIGHT ENTRANCE REGION OF A 300MB JET STREAK...AND STRONG THETA-E RIDGING AHEAD OF THE FRONT WILL SUPPORT WIDESPREAD SHOWERS WITH TSTMS ON MONDAY...AND HAVE BUMPED POP TO LIKELY CWA-WIDE. THE HIGHEST POP IS EXPECTED LATE MONDAY/MONDAY NIGHT. FRONT MAY TAKE A WHILE TO CROSS THE AREA...AND THUS LOW-CHC POP IS STILL WARRANTED INTO TUESDAY MORNING BEFORE SIGNIFICANT DRYING OCCURS WITHIN THE COLUMN THANKS TO HIGH PRESSURE BUILDING DOWN FROM THE NORTH. THIS WILL CREATE SEVERAL DAYS OF SEASONABLE EARLY-JUNE WEATHER. LATE IN THE WEEK...HIGH PRESSURE SHIFTS OFFSHORE PUMPING ATLANTIC MOISTURE BACK INTO THE AREA...AND DIURNAL CONVECTION WILL BECOME INCREASINGLY LIKELY AGAIN. ADDITIONALLY...WHILE THE FAVORED ECMWF KEEPS ANY TROPICAL MOISTURE WELL SW OF THE CAROLINAS...GFS DOES SUGGEST SIGNIFICANT RAIN CHANCES BEGINNING FRIDAY AS MOISTURE STREAMS OUT OF THE GOM. FOR NOW WILL LEAN HEAVILY ON THE ECMWF BUT NOTE THAT MONITORING GUIDANCE EVOLUTION WILL BE IMPORTANT LEADING INTO NEXT WEEKEND. && .AVIATION /18Z FRIDAY THROUGH TUESDAY/... AS OF 18Z...RADAR IMAGERY SHOWS SCATTERED SHOWERS/T-STORMS DEVELOPING ALONG THE SEA BREEZE BOUNDARY THIS AFTN. HAVE INCLUDED VCSH FOR KFLO/KLBT AS LATEST HRRR RUNS SHOW MORE SHOWERS DEVELOPING INLAND LATER TODAY. OTHERWISE...VFR SHOULD PREVAIL WITH SCT/BKN CU AND SSE WINDS AOB 10 KTS. MOSTLY CLEAR CONDITIONS TONIGHT AND PLENTY OF LOW-LEVEL MOISTURE INDICATES FOG/STRATUS IS AGAIN LIKELY AFTER 06Z. SREF PROBS AND GUIDANCE SUGGEST IFR CIGS/VSBYS WILL BE MORE WIDESPREAD INLAND...SIMILAR TO WHAT OCCURRED THIS MORNING. TEMPO IFR IS ALSO QUITE POSSIBLE ALONG THE COAST...MOST LIKELY IN THE 09-12Z RANGE. FOG/STRATUS SHOULD LIFT SOON AFTER 12Z SATURDAY. EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS/VSBYS POSSIBLE THROUGH SUNDAY. SLIGHT CHANCE OF SHOWERS INLAND ON SUNDAY...WITH BETTER PCPN CHANCES ACROSS THE CWA MONDAY AND TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM FRIDAY...BERMUDA HIGH PRESSURE CONTINUES TO EXTEND A RIDGE AXIS WESTWARD ACROSS THE CAROLINAS AT NEARLY THE SAME LATITUDE AS LAST NIGHT. THEREFORE IT SHOULD NOT BE SURPRISING THE ANTICIPATED WIND DIRECTION AND SPEED TONIGHT IS VERY SIMILAR TO LAST NIGHT. SOUTH WINDS 5-10 KNOTS SHOULD PREVAIL THROUGH THE NIGHT AFTER THIS AFTERNOON`S SEA BREEZE CIRCULATION DIES DOWN BY 9-10 PM. SEAS ARE AVERAGING 3 FEET ON THE BUOYS NEAR CAPE FEAR WITH A DOMINANT PERIOD AROUND 8 SECONDS. THIS IS VERY WELL MODELED IN THE NOAA WAVEWATCH MODEL WHICH SHOWS THIS SOUTHEAST SWELL CONTINUING UNCHANGED THROUGH THE NIGHT. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 3 PM FRIDAY...EXPECT SOUTHERLY RETURN FLOW TO CONTINUE AROUND WESTERN PERIPHERY OF BERMUDA HIGH THROUGH THE WEEKEND. BY SUNDAY AFTERNOON INTO SUNDAY NIGHT THE GRADIENT WILL BEGIN TO TIGHTEN AS COLD FRONT APPROACHES THE CAROLINAS FROM THE WEST. OVERALL EXPECT SOUTHERLY FLOW CLOSER TO 5 TO 10 KTS THROUGH THE FIRST HALF OF THE WEEKEND AND UP TO 15 KTS BY SUN EVENING. THE WAVE HEIGHTS WILL RESPOND TO INCREASE IN SOUTHERLY FLOW BY RISING CLOSER TO 3 TO 4 FT BY SUN NIGHT. BASICALLY SEAS WILL HOLD BETWEEN 2 AND 4 FT THROUGH THE WEEKEND. EXPECT A SLIGHT SPIKE UP IN WINDS AND SEAS EACH AFTN AND A SLIGHT CHOP NEAR SHORE IN SEA BREEZE EACH AFTERNOON. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 300 PM FRIDAY...PRE-FRONTAL REGIME TO START THE PERIOD WITH GUSTY SOUTHERLY WINDS ONGOING ACROSS THE WATERS. SOUTHERLY WINDS OF 10-15 KTS WILL BE THE RULE MONDAY...BEFORE VEERING TO THE WEST EARLY TUESDAY. DO NOT EXPECT WINDS TO BECOME NORTHERLY AS FRONT STALLS AND WASHES OUT OVER THE AREA DURING TUESDAY...AND EVENTUALLY WILL BACK TO THE E/SE...AND FINALLY THE NE ON WEDNESDAY AS HIGH PRESSURE RIDGES DOWN THE COAST. WHILE WIND SPEEDS WILL BE RELATIVELY LIGHT TUESDAY...THEY WILL INCREASE TO AROUND 15 KTS WITHIN THE PINCHED GRADIENT WEDNESDAY. WHILE A 2FT/8SEC SE SWELL WILL PERSIST AND SLOWLY DAMPEN THROUGH THE PERIOD...WIND WAVES WILL SHOW AN INCREASING CONTRIBUTION TO THE SPECTRUM...ESPECIALLY MON AND WED. SEAS WILL BE GENERALLY 2-4 FT BUT WITH SOME ISOLATED 5 FTERS MONDAY EVE AHEAD OF THE COLD FRONT...AND AGAIN ON WEDNESDAY WITH THE STRONGER E/NE WINDS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...RGZ LONG TERM...JDW AVIATION...BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT FRI MAY 31 2013 .SYNOPSIS... HIGH PRESSURE WILL REMAIN SOLIDLY OVER THE REGION THROUGH SATURDAY... THEN SHIFT OFFSHORE SUNDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE WEST SUNDAY...THEN CROSS THE REGION MONDAY AND MONDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 PM FRIDAY... OVERVIEW: AN UPPER LEVEL RIDGE CENTERED ALONG THE SOUTHEAST AND MID-ATLANTIC COAST WILL FURTHER WEAKEN THROUGH TONIGHT AS AN UPPER LEVEL LOW CENTERED OVER THE NORTHERN PLAINS MOVES SLOWLY EAST INTO THE NORTHERN MS RIVER VALLEY. A SFC-H85 RIDGE WILL PERSIST OFFSHORE OF THE CAROLINAS...WITH AN INCREASINGLY MOIST SOUTHERLY RETURN FLOW ACROSS THE REGION. TEMPERATURES: HIGHS TODAY APPEAR VERY SIMILAR TO THE PREVIOUS FEW DAYS GIVEN LITTLE CHANGE IN THICKNESSES AND A VERY SIMILAR (ALBEIT INCREASINGLY MOIST) AIRMASS. THE MAIN FACTORS W/REGARD TO HIGH TEMPS ARE APT TO BE THE SEABREEZE APPROACHING FROM THE S/SE AND ISOLD CONVECTION /OUTFLOW/ EXPECTED DURING THE MID TO LATE AFTERNOON...PRIMARILY EAST OF HWY 1 AND SOUTH OF HWY 64 (SANDHILL/SE COASTAL PLAIN) WHERE THE SEABREEZE PASSAGE WILL OCCUR THE EARLIEST...THOUGH EVEN IN THOSE AREAS DIURNAL HEATING MAY BE SUFFICIENT FOR TEMPS TO REACH THE UPPER 80S. WITH THE ABOVE IN MIND...WILL INDICATE HIGHS IN THE MID/UPPER 80S...WARMEST IN VICINITY OF HWY 1. EXPECT LOWS TONIGHT SLIGHTLY WARMER THAN LAST NIGHT DUE TO INCREASED BOUNDARY LAYER MOISTURE... IN THE MID/UPPER 60S. CONVECTION: WEAK BUT PERSISTENT SOUTHERLY RETURN FLOW WILL ADVECT AN INCREASINGLY MOIST AIRMASS FROM THE ATLANTIC INTO CENTRAL NC... CHARACTERIZED BY SFC DEWPOINTS IN THE MID/UPPER 60S...H925 DEWPOINTS OF 13-15C AND H85 DEWPOINTS OF 10-12C DURING THE MID/LATE AFTERNOON HOURS. MID-LEVEL LAPSE RATES HAVE DECREASED IN COMPARISON TO YESTERDAY AS THE RIDGE ALOFT WEAKENS...AND THE LATEST RAP GUIDANCE SUGGEST H7-H5 LAPSE RATES ON THE ORDER OF 5.5-6.5 C/KM DURING PEAK HEATING...STEEPEST IN THE EAST. IN THIS ENVIRONMENT...EXPECT MODERATE DESTABILIZATION WITH MLCAPE VALUES OF 1000-1500 J/KG BY PEAK HEATING AND LITTLE OR NO CIN. FORCING WILL LARGELY BE LIMITED TO CONVERGENCE ALONG THE SEABREEZE THIS AFTERNOON...THOUGH LATEST WV IMAGERY AND RAP DATA SUGGEST A WEAK N-S ORIENTED H3 SHEAR AXIS OVER THE SOUTHERN APPALACHIANS SHOULD PROGRESS SLOWLY EAST INTO THE WESTERN PIEDMONT BY 21-00Z. WITH THE ABOVE IN MIND...EXPECT A RELATIVELY MORE ACTIVE SEABREEZE THAN YESTERDAY...WITH ISOLD SHOWERS AND PERHAPS A FEW STORMS BY LATE AFTERNOON...PRIMARILY SOUTH OF HWY 64 ACROSS THE EASTERN SANDHILLS AND SE COASTAL PLAIN...WITH ANY ACTIVITY WANING IN VICINITY OF THE TRIANGLE OR HWY 1 CORRIDOR BY OR SHORTLY AFTER SUNSET. CONVECTION WILL REMAIN DISORGANIZED GIVEN NEGLIGIBLE DEEP-LAYER SHEAR UNDER THE WEAKENING RIDGE...THOUGH MODERATE DCAPE (~1000 J/KG) WOULD SUGGEST SOME POTENTIAL FOR ENHANCED COLD POOLS...PRIMARILY ACROSS SCOTLAND...HOKE... CUMBERLAND...SAMPSON AND WAYNE COUNTIES BETWEEN 20-00Z. -VINCENT && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 230 PM FRIDAY... SATURDAY AND SATURDAY NIGHT... THOUGH THE UPPER LEVEL RIDGE WILL CONTINUE TO WEAKEN IN COMPARISON TO PREVIOUS DAYS...RIDGING ALOFT WILL REMAIN IN PLACE OVER THE CAROLINAS AS THE SLOW MOVING UPPER LEVEL TROUGH CURRENTLY OVER THE CENTRAL PLAINS PROGRESSES EAST INTO THE TN/OH RIVER VALLEYS. LOW-LEVEL MOISTURE AND PWAT VALUES ARE PROGGED TO FURTHER INCREASE ACROSS CENTRAL NC ON SATURDAY...THOUGH MID-LEVEL LAPSE RATES WILL BE SIMILAR OR SLIGHTLY WEAKER THAN TODAY AT 5.5-6.0 C/KM. DIURNAL DESTABILIZATION SAT AFTERNOON SHOULD ALSO BE SIMILAR TO TODAY... WITH ~1000 J/KG OF MLCAPE. FORCING WILL ONCE AGAIN BE LIMITED TO WEAK LOW-LEVEL CONVERGENCE ALONG THE SEABREEZE...THOUGH INCREASING W/SW FLOW ALOFT ACROSS WESTERN PORTIONS OF THE STATE MAY ALLOW FOR SOME EASTWARD PROPAGATION OF ISOLD CONVECTION THAT DEVELOPS IN ASSOC/W DIFFERENTIAL HEATING OVER THE HIGHER TERRAIN IN WESTERN NC. WITH THIS IN MIND...WILL KEEP A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE S/SE AND WILL INTRODUCE A SLIGHT CHANCE IN THE FAR WESTERN PIEDMONT AS WELL. EXPECT TEMPS SIMILAR TO PREVIOUS DAYS WITH HIGHS IN THE UPPER 80S AND LOWS IN THE UPPER 60S...SLIGHTLY WARMER THAN TONIGHT GIVEN A FURTHER INCREASE IN BOUNDARY LAYER MOISTURE. -VINCENT SUNDAY AND SUNDAY NIGHT...THE MID/UPPER LEVEL TROUGH THAT HAS WET DOWN THE MIDWEST RECENTLY IS FORECAST TO FINALLY NUDGE EAST TOWARD THE OHIO VALLEY AND CENTRAL APPALACHIANS SUNDAY AND SUNDAY NIGHT. THE RIDGE OVER OUR REGION WILL BREAK DOWN AND SHIFT EAST ALLOWING THE SURFACE HIGH PRESSURE TO MOVE OFFSHORE AS WELL. DEEP MOISTURE (PRECIPITABLE WATER VALUES 150 TO 200 PERCENT OF NORMAL) FROM THE GULF OF MEXICO IS FORECAST TO CONTINUE FEEDING NORTHWARD AHEAD OF THE EASTWARD MOVING COLD FRONT THAT SHOULD BE APPROACHING THE WESTERN SLOPES OF THE APPALACHIANS BY LATE SUNDAY. SEVERAL LINES OF CONVECTION SHOULD BE ONGOING SUNDAY OVER EASTERN TN/KY... SPREADING INTO THE MOUNTAINS OF NC/VA DURING THE AFTERNOON. SINCE MODELS INDICATE THE BEST MID LEVEL HEIGHT FALLS TO OCCUR TO OUR WEST AND NORTH INTO SUNDAY EVENING... MUCH OF THE DEEP CONVECTION WILL REMAIN JUST TO OUR WEST AND NORTH UNTIL LATE AFTERNOON. HOWEVER... SCATTERED DIURNALLY/TERRAIN DRIVEN THUNDERSTORMS ARE FAVORED ALONG THE BLUE RIDGE DURING PEAK HEATING... POSSIBLY SPREADING OUT INTO THE NW PIEDMONT DURING THE LATE AFTERNOON. WE WILL MAINTAIN THE CHANCE POP FOR THE WINSTON-SALEM AND GREENSBORO AREAS SUNDAY AFTERNOON. ELSEWHERE... PARTLY SUNNY SKIES AND CONTINUED WARM AND HUMID. HIGHS 85-90. BY SUNDAY EVENING AND OVERNIGHT...A LINE OF DEEP CONVECTION IS SUPPORTED TO AFFECT PORTIONS OF OUR WESTERN AND NORTHERN PIEDMONT DURING THE EVENING INTO THE OVERNIGHT HOURS. LOCALLY HEAVY RAIN IS EXPECTED WITH THE PW`S FORECAST TO REACH 150-200 PERCENT OF NORMAL AND SURFACE DEW POINTS NEARING 70. THIS ACTIVITY MAY CONTINUE TO ADVANCE SLOWLY EASTWARD THROUGH THE PIEDMONT OVERNIGHT... WITH A CHANCE OF THE ACTIVITY SPREADING INTO THE SANDHILLS AND WESTERN COASTAL PLAIN WELL AFTER MIDNIGHT. WE HAVE LIKELY POP IN THE WEST AND NORTH... WITH CHANCE POP EAST AND SOUTH OF THAT AREA OVERNIGHT. A SSW LOW LEVEL FLOW OF 10-15 MPH WILL KEEP TEMPERATURES IN THE LOWER TO MID 70S EXCEPT UPPER 60S IN THE RAIN COOLED NW PIEDMONT BY 12Z/MON. THE SEVERE THREAT APPEARS MARGINAL FOR NOW... WITH THE MAIN DYNAMICS WELL TO THE NW. HOWEVER... LOCALLY HEAVY RAIN WITH SLOW MOVING AND TRAINING OF STORMS WILL BE POSSIBLE IN THE NW. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 210 PM FRIDAY... AT LEAST SOME CONVECTION SHOULD BE ONGOING IN A WEAKENED STATE AT DAYBREAK MONDAY. IT IS TOO EARLY TO TELL HOW FAR EAST THE PREVIOUS NIGHTS CONVECTION WILL MAKE IT... BUT CONVECTIVE OUTFLOW BOUNDARIES SHOULD PLAY A CRITICAL ROLE IN THE CONVECTIVE EVOLUTION MONDAY. THE MAIN COLD FRONT IS FORECAST TO BE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE AT 12Z... THEN SLOWLY PUSH ESE THROUGH CENTRAL NORTH CAROLINA MONDAY AFTERNOON AND EVENING. THERE MAY BE SEVERAL BANDS OF CONVECTION THAT DEVELOP AND AFFECT THE REGION MONDAY. THE FIRST WITH THE RESIDUAL OUTFLOWS AND THE NEXT ALONG OR AHEAD OF THE ACTUAL COLD FRONT. WE WILL MAINTAIN THE LIKELY POP IN A BROAD BRUSH FASHION MONDAY... THEN CONTINUE THE TREND OF TAPERING POP FROM THE NW MONDAY EVENING AND NIGHT. HOWEVER... DUE TO THE EXPECTED SLOW MOVEMENT OF THE COLD FRONT (SHOULD BE NEAR THE COAST BY 12Z TUESDAY)... LOCALLY HEAVY RAIN CAN FOCUS/OCCUR OVER THE REGION THROUGH 12Z/TUE). THE FAR NW ZONES SHOULD (BEGIN/END) FIRST WITH THIS HEAVY RAIN THREATS. COOLER CONDITIONS WILL PREVAIL DUE TO THE RAIN/CLOUDS MONDAY... THEN THE CAA WITH THE NE LOW LEVEL FLOW BEGINNING TUESDAY. INDICATIONS ARE THAT CLOUDINESS AND THE THREAT OF RAIN MAY CONTINUE TUESDAY AS A SECONDARY WAVE MAY FORM ALONG THE FRONT OVER COASTAL SC. WE WILL KEEP AT LEAST SOME POP CHANCES IN THE EAST AND SOUTH TUESDAY. LOWS 60-68. HIGHS TUESDAY 75-82. WEDNESDAY THROUGH FRIDAY... SLIGHTLY DRIER MID LEVELS... ASSOCIATED WITH MID LEVEL RIDGING AND A MODERATELY STRONG (1026+ MB) SURFACE HIGH PRESSURE EXTENDING FROM PA/NY INTO NC/SC WED-THU... IS INDICATED. HOWEVER... THE NE BECOMING E LOW LEVEL FLOW SUGGESTS LATE NIGHT AND MORNING CLOUDINESS BOTH DAYS WED-THU. LOWS 57-64. HIGHS 78-83. BY FRIDAY... ANOTHER APPROACHING MID/UPPER LEVEL TROUGH FROM THE CENTRAL U.S. SHOULD BEGIN TO AFFECT THE REGION. HOWEVER... WE WILL MAINTAIN SLIGHT CHANCES FOR NOW ON DAY 7. IN GENERAL... VARIABLY CLOUDY WITH A SE FLOW WILL CONTINUE MILD DAYS INTO FRIDAY. LOWS IN THE 60S. HIGHS FRIDAY IN THE LOWER TO MID 80S. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 1220 PM FRIDAY... 24-HR TAF PERIOD: VFR CONDITIONS WITH CEILINGS BETWEEN 4000-5000 FT AGL WILL PREVAIL IN MOST AREAS THROUGH THIS EVENING...ASIDE FROM A CHANCE OF ISOLD SHOWERS AND STORMS BETWEEN 20-00Z...PRIMARILY AT THE FAY TERMINAL... THOUGH POSSIBLY AS FAR NORTH AS THE RDU/RWI TERMINALS PRIOR TO DISSIPATING. OVERNIGHT...EXPECT A GOOD POTENTIAL FOR IFR/LIFR STRATUS OR FOG AT ALL TERMINALS BETWEEN 07-13Z SAT...WITH ANY FOG/STRATUS LIFTING TO VFR BY MID SAT MORNING. VFR CONDITIONS WITH CEILINGS 4000-5000 FT AGL ARE EXPECTED DURING THE DAY SATURDAY. LOOKING AHEAD: MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG AND AHEAD OF A COLD FRONT PROGRESSING SLOWLY EAST THROUGH CENTRAL NC SUN NIGHT AND MONDAY...BEGINNING IN THE WESTERN PIEDMONT (INT/GSO TERMINALS) LATE SUNDAY AFT/EVE...EVENTUALLY ENDING FROM WEST TO EAST LATE MON INTO MON NIGHT. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...PWB NEAR TERM...VINCENT SHORT TERM...VINCENT/PWB LONG TERM...PWB AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
210 PM EDT FRI MAY 31 2013 .SYNOPSIS... HIGH PRESSURE WILL REMAIN SOLIDLY OVER THE REGION THROUGH SATURDAY... THEN SHIFT OFFSHORE SUNDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE WEST SUNDAY...THEN CROSS THE REGION MONDAY AND MONDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1130 AM FRIDAY... OVERVIEW: AN UPPER LEVEL RIDGE CENTERED ALONG THE SOUTHEAST AND MID-ATLANTIC COAST WILL FURTHER WEAKEN THROUGH TONIGHT AS AN UPPER LEVEL LOW CENTERED OVER THE NORTHERN PLAINS MOVES SLOWLY EAST INTO THE NORTHERN MS RIVER VALLEY. A SFC-H85 RIDGE WILL PERSIST OFFSHORE OF THE CAROLINAS...WITH AN INCREASINGLY MOIST SOUTHERLY RETURN FLOW ACROSS THE REGION. TEMPERATURES: HIGHS TODAY APPEAR VERY SIMILAR TO THE PREVIOUS FEW DAYS GIVEN LITTLE CHANGE IN THICKNESSES AND A VERY SIMILAR (ALBEIT INCREASINGLY MOIST) AIRMASS. THE MAIN FACTORS W/REGARD TO HIGH TEMPS ARE APT TO BE THE SEABREEZE APPROACHING FROM THE S/SE AND ISOLD CONVECTION /OUTFLOW/ EXPECTED DURING THE MID TO LATE AFTERNOON...PRIMARILY EAST OF HWY 1 AND SOUTH OF HWY 64 (SANDHILL/SE COASTAL PLAIN) WHERE THE SEABREEZE PASSAGE WILL OCCUR THE EARLIEST...THOUGH EVEN IN THOSE AREAS DIURNAL HEATING MAY BE SUFFICIENT FOR TEMPS TO REACH THE UPPER 80S. WITH THE ABOVE IN MIND...WILL INDICATE HIGHS IN THE MID/UPPER 80S...WARMEST IN VICINITY OF HWY 1. EXPECT LOWS TONIGHT SLIGHTLY WARMER THAN LAST NIGHT DUE TO INCREASED BOUNDARY LAYER MOISTURE... IN THE MID/UPPER 60S. CONVECTION: WEAK BUT PERSISTENT SOUTHERLY RETURN FLOW WILL ADVECT AN INCREASINGLY MOIST AIRMASS FROM THE ATLANTIC INTO CENTRAL NC... CHARACTERIZED BY SFC DEWPOINTS IN THE MID/UPPER 60S...H925 DEWPOINTS OF 13-15C AND H85 DEWPOINTS OF 10-12C DURING THE MID/LATE AFTERNOON HOURS. MID-LEVEL LAPSE RATES HAVE DECREASED IN COMPARISON TO YESTERDAY AS THE RIDGE ALOFT WEAKENS...AND THE LATEST RAP GUIDANCE SUGGEST H7-H5 LAPSE RATES ON THE ORDER OF 5.5-6.5 C/KM DURING PEAK HEATING...STEEPEST IN THE EAST. IN THIS ENVIRONMENT...EXPECT MODERATE DESTABILIZATION WITH MLCAPE VALUES OF 1000-1500 J/KG BY PEAK HEATING AND LITTLE OR NO CIN. FORCING WILL LARGELY BE LIMITED TO CONVERGENCE ALONG THE SEABREEZE THIS AFTERNOON...THOUGH LATEST WV IMAGERY AND RAP DATA SUGGEST A WEAK N-S ORIENTED H3 SHEAR AXIS OVER THE SOUTHERN APPALACHIANS SHOULD PROGRESS SLOWLY EAST INTO THE WESTERN PIEDMONT BY 21-00Z. WITH THE ABOVE IN MIND...EXPECT A MORE ACTIVE SEABREEZE THAN YESTERDAY...WITH ISOLD TO SCT SHOWERS AND STORMS BETWEEN BY MID/LATE AFTERNOON...PRIMARILY SOUTH OF HWY 64 ACROSS THE EASTERN SANDHILLS AND SE COASTAL PLAIN...WITH ACTIVITY WANING IN VICINITY OF THE TRIANGLE OR HWY 1 CORRIDOR BY OR SHORTLY AFTER SUNSET. CONVECTION WILL REMAIN DISORGANIZED GIVEN NEGLIGIBLE DEEP-LAYER SHEAR UNDER THE WEAKENING RIDGE...THOUGH MODERATE DCAPE (~1000 J/KG) WOULD SUGGEST SOME POTENTIAL FOR ENHANCED COLD POOLS AND PERHAPS AN ISOLD DOWNBURST...PRIMARILY ACROSS SCOTLAND...HOKE... CUMBERLAND...SAMPSON AND WAYNE COUNTIES BETWEEN 19-23Z. -VINCENT && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 210 PM FRIDAY... SATURDAY AND SATURDAY NIGHT... SUNDAY AND SUNDAY NIGHT... THE MID/UPPER LEVEL TROUGH THAT HAS WET DOWN THE MIDWEST RECENTLY IS FORECAST TO FINALLY NUDGE EAST TOWARD THE OHIO VALLEY AND CENTRAL APPALACHIANS SUNDAY AND SUNDAY NIGHT. THE RIDGE OVER OUR REGION WILL BREAK DOWN AND SHIFT EAST ALLOWING THE SURFACE HIGH PRESSURE TO MOVE OFFSHORE AS WELL. DEEP MOISTURE (PRECIPITABLE WATER VALUES 150 TO 200 PERCENT OF NORMAL) FROM THE GULF OF MEXICO IS FORECAST TO CONTINUE FEEDING NORTHWARD AHEAD OF THE EASTWARD MOVING COLD FRONT THAT SHOULD BE APPROACHING THE WESTERN SLOPES OF THE APPALACHIANS BY LATE SUNDAY. SEVERAL LINES OF CONVECTION SHOULD BE ONGOING SUNDAY OVER EASTERN TN/KY... SPREADING INTO THE MOUNTAINS OF NC/VA DURING THE AFTERNOON. SINCE MODELS INDICATE THE BEST MID LEVEL HEIGHT FALLS TO OCCUR TO OUR WEST AND NORTH INTO SUNDAY EVENING... MUCH OF THE DEEP CONVECTION WILL REMAIN JUST TO OUR WEST AND NORTH UNTIL LATE AFTERNOON. HOWEVER... SCATTERED DIURNALLY/TERRAIN DRIVEN THUNDERSTORMS ARE FAVORED ALONG THE BLUE RIDGE DURING PEAK HEATING... POSSIBLY SPREADING OUT INTO THE NW PIEDMONT DURING THE LATE AFTERNOON. WE WILL MAINTAIN THE CHANCE POP FOR THE WINSTON-SALEM AND GREENSBORO AREAS SUNDAY AFTERNOON. ELSEWHERE... PARTLY SUNNY SKIES AND CONTINUED WARM AND HUMID. HIGHS 85-90. BY SUNDAY EVENING AND OVERNIGHT... A LINE OF DEEP CONVECTION IS SUPPORTED TO AFFECT PORTIONS OF OUR WESTERN AND NORTHERN PIEDMONT DURING THE EVENING INTO THE OVERNIGHT HOURS. LOCALLY HEAVY RAIN IS EXPECTED WITH THE PW`S FORECAST TO REACH 150-200 PERCENT OF NORMAL AND SURFACE DEW POINTS NEARING 70. THIS ACTIVITY MAY CONTINUE TO ADVANCE SLOWLY EASTWARD THROUGH THE PIEDMONT OVERNIGHT... WITH A CHANCE OF THE ACTIVITY SPREADING INTO THE SANDHILLS AND WESTERN COASTAL PLAIN WELL AFTER MIDNIGHT. WE HAVE LIKELY POP IN THE WEST AND NORTH... WITH CHANCE POP EAST AND SOUTH OF THAT AREA OVERNIGHT. A SSW LOW LEVEL FLOW OF 10-15 MPH WILL KEEP TEMPERATURES IN THE LOWER TO MID 70S EXCEPT UPPER 60S IN THE RAIN COOLED NW PIEDMONT BY 12Z/MON. THE SEVERE THREAT APPEARS MARGINAL FOR NOW... WITH THE MAIN DYNAMICS WELL TO THE NW. HOWEVER... LOCALLY HEAVY RAIN WITH SLOW MOVING AND TRAINING OF STORMS WILL BE POSSIBLE IN THE NW. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 210 PM FRIDAY... AT LEAST SOME CONVECTION SHOULD BE ONGOING IN A WEAKENED STATE AT DAYBREAK MONDAY. IT IS TOO EARLY TO TELL HOW FAR EAST THE PREVIOUS NIGHTS CONVECTION WILL MAKE IT... BUT CONVECTIVE OUTFLOW BOUNDARIES SHOULD PLAY A CRITICAL ROLE IN THE CONVECTIVE EVOLUTION MONDAY. THE MAIN COLD FRONT IS FORECAST TO BE ALONG THE EASTERN SLOPES OF THE BLUE RIDGE AT 12Z... THEN SLOWLY PUSH ESE THROUGH CENTRAL NORTH CAROLINA MONDAY AFTERNOON AND EVENING. THERE MAY BE SEVERAL BANDS OF CONVECTION THAT DEVELOP AND AFFECT THE REGION MONDAY. THE FIRST WITH THE RESIDUAL OUTFLOWS AND THE NEXT ALONG OR AHEAD OF THE ACTUAL COLD FRONT. WE WILL MAINTAIN THE LIKELY POP IN A BROAD BRUSH FASHION MONDAY... THEN CONTINUE THE TREND OF TAPERING POP FROM THE NW MONDAY EVENING AND NIGHT. HOWEVER... DUE TO THE EXPECTED SLOW MOVEMENT OF THE COLD FRONT (SHOULD BE NEAR THE COAST BY 12Z TUESDAY)... LOCALLY HEAVY RAIN CAN FOCUS/OCCUR OVER THE REGION THROUGH 12Z/TUE). THE FAR NW ZONES SHOULD (BEGIN/END) FIRST WITH THIS HEAVY RAIN THREATS. COOLER CONDITIONS WILL PREVAIL DUE TO THE RAIN/CLOUDS MONDAY... THEN THE CAA WITH THE NE LOW LEVEL FLOW BEGINNING TUESDAY. INDICATIONS ARE THAT CLOUDINESS AND THE THREAT OF RAIN MAY CONTINUE TUESDAY AS A SECONDARY WAVE MAY FORM ALONG THE FRONT OVER COASTAL SC. WE WILL KEEP AT LEAST SOME POP CHANCES IN THE EAST AND SOUTH TUESDAY. LOWS 60-68. HIGHS TUESDAY 75-82. WEDNESDAY THROUGH FRIDAY... SLIGHTLY DRIER MID LEVELS... ASSOCIATED WITH MID LEVEL RIDGING AND A MODERATELY STRONG (1026+ MB) SURFACE HIGH PRESSURE EXTENDING FROM PA/NY INTO NC/SC WED-THU... IS INDICATED. HOWEVER... THE NE BECOMING E LOW LEVEL FLOW SUGGESTS LATE NIGHT AND MORNING CLOUDINESS BOTH DAYS WED-THU. LOWS 57-64. HIGHS 78-83. BY FRIDAY... ANOTHER APPROACHING MID/UPPER LEVEL TROUGH FROM THE CENTRAL U.S. SHOULD BEGIN TO AFFECT THE REGION. HOWEVER... WE WILL MAINTAIN SLIGHT CHANCES FOR NOW ON DAY 7. IN GENERAL... VARIABLY CLOUDY WITH A SE FLOW WILL CONTINUE MILD DAYS INTO FRIDAY. LOWS IN THE 60S. HIGHS FRIDAY IN THE LOWER TO MID 80S. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 1220 PM FRIDAY... 24-HR TAF PERIOD: VFR CONDITIONS WITH CEILINGS BETWEEN 4000-5000 FT AGL WILL PREVAIL IN MOST AREAS THROUGH THIS EVENING...ASIDE FROM A CHANCE OF ISOLD SHOWERS AND STORMS BETWEEN 20-00Z...PRIMARILY AT THE FAY TERMINAL... THOUGH POSSIBLY AS FAR NORTH AS THE RDU/RWI TERMINALS PRIOR TO DISSIPATING. OVERNIGHT...EXPECT A GOOD POTENTIAL FOR IFR/LIFR STRATUS OR FOG AT ALL TERMINALS BETWEEN 07-13Z SAT...WITH ANY FOG/STRATUS LIFTING TO VFR BY MID SAT MORNING. VFR CONDITIONS WITH CEILINGS 4000-5000 FT AGL ARE EXPECTED DURING THE DAY SATURDAY. LOOKING AHEAD: MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG AND AHEAD OF A COLD FRONT PROGRESSING SLOWLY EAST THROUGH CENTRAL NC SUN NIGHT AND MONDAY...BEGINNING IN THE WESTERN PIEDMONT (INT/GSO TERMINALS) LATE SUNDAY AFT/EVE...EVENTUALLY ENDING FROM WEST TO EAST LATE MON INTO MON NIGHT. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...PWB/V NEAR TERM...V SHORT TERM...V/PWB LONG TERM...PWB AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
116 PM EDT FRI MAY 31 2013 .SYNOPSIS... BERMUDA HIGH PRESSURE WILL CONTINUE ACROSS THE CAROLINAS THROUGH THE WEEKEND. A COLD FRONT WILL SLOWLY MOVE THROUGH THE AREA EARLY NEXT WEEK...BRINGING THE HIGHEST POTENTIAL FOR SHOWERS AND THUNDERSTORMS MONDAY AND TUESDAY. HIGH PRESSURE WILL SLOWLY BUILD SOUTHWARD AND INTO THE AREA DURING THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM FRIDAY...SHOWER/T-STORM ACTIVITY IS CENTERED ALONG TWO PORTIONS OF THE SEABREEZE BOUNDARY: CENTRAL HORRY COUNTY AND THE CAPE FEAR RIVER JUST NW OF WILMINGTON. THIS ACTIVITY SHOULD MAINTAIN ITSELF OR PERHAPS WEAKEN SLIGHTLY AS IT MOVES NORTHWARD THROUGH THE NEXT FEW HOURS. ISOLATED SHOWERS WILL PROBABLY DEVELOP BACK ACROSS THE PEE DEE REGION AS WELL. SMALL DOWNWARD ADJUSTMENTS TO TEMPERATURES HAVE BEEN MADE NEAR THE COAST WHERE CLOUDINESS AND SHOWERS HAVE HELD TEMPERATURES DOWN. PREVIOUS DISCUSSION FROM 1130 AM FOLLOWS... JUST A QUICK NEAR-TERM UPDATE TO INCREASE POPS ALONG AND WEST OF THE SEABREEZE BOUNDARY. CURRENT RADAR LOOKS A LITTLE MORE ACTIVE THAN I HAD ANTICIPATED WITH EXCELLENT MOISTURE POOLING ALONG THE BOUNDARY WITHIN THE REGION OF STEEP LOW LEVEL LAPSE RATES. NO OTHER SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS... BERMUDA HIGH PRESSURE EXTENDS WESTWARD INTO THE CAROLINAS AGAIN TODAY. THIS MEANS A CONTINUATION OF SEASONABLY WARM AND MOIST ONSHORE WINDS. THE MOISTURE CONTENT OF THIS AIRMASS HAS GROWN OVER THE PAST COUPLE OF DAYS...AND THIS COULD BE TERMED A MARITIME TROPICAL AIRMASS WITH SURFACE DEWPOINTS AROUND 70 DEGREES F AND PRECIPITABLE WATER VALUES CLIMBING TO 1.4 INCHES. THE PRECIPITABLE WATER WOULD BE HIGHER IF IT WEREN`T FOR A CONSIDERABLE LAYER OF DRY AIR LURKING AT AND ABOVE 700 MB WHERE DEWPOINT DEPRESSIONS ARE IN EXCESS OF 30 DEGREES F. THERMALLY THERE IS ONLY A HINT OF A SUBSIDENCE INVERSION AROUND 700 MB/10000 FT AGL TODAY. LAPSE RATES BELOW THIS LEVEL ARE STEEP ENOUGH TO ENSURE WE GET LOTS OF TOWERING CUMULUS TODAY WITH ISOLATED SHOWERS ALONG AND WEST OF THE SEABREEZE BOUNDARY. A FEW SHOWERS MAY BREAK THROUGH THIS WEAK CONVECTIVE CAP AND BECOME THUNDERSTORMS THIS AFTERNOON...BUT ALL THE DRY AIR ALOFT SHOULD MIX INTO THE UPDRAFTS AND WEAKEN THESE STORMS IN SHORT ORDER. COVERAGE OF SHOWERS/STORMS INLAND FROM THE COAST SHOULD BE 20-25 PERCENT THIS TODAY. HIGH TEMPERATURES WILL END UP VERY CLOSE TO YESTERDAY`S READINGS: UPPER 80S INLAND WITH LOWER TO MID 80S CLOSER TO THE COAST. THE BEACHES WILL TOP OUT AROUND 80 WITH A SLIGHTLY COOLER MARINE AIRMASS PUSHING ONSHORE. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 245 AM FRIDAY...MID LEVEL HEIGHTS WILL SLOWLY DECREASE THROUGH THE PERIOD WITH MOISTURE PROFILES FLUCTUATING SOMEWHAT. BERMUDA HIGH PRESSURE CONTINUE TO BE THE MAIN FIXTURE AT THE SURFACE. MOISTURE PROFILES ARE ACTUALLY A LITTLE HIGHER SATURDAY AND I HAVE INCLUDED LOW CHANCE POPS FOR MOST INLAND AREAS FOR THE AFTERNOON HOURS. SUNDAY SHOULD BE MOSTLY DRY AS PRECIPITABLE WATER VALUES ACTUALLY DROP DURING THE DAY WHEN COMPARED TO SATURDAY. CONTINUED TO TREND POPS SLOWLY UPWARD SUNDAY NIGHT INTO MONDAY MORNING VIA THE LONG ADVERTISED TROUGH AND ASSOCIATED COLD FRONT MOVING CLOSER. NUMERICAL GUIDANCE HAS WARMED SLIGHTLY WITH REGARDS TO TEMPERATURES AS HAS THE OFFICIAL FORECAST. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 245 AM FRIDAY...THE ECMWF ENSEMBLE MEAN CONTINUES TO BE THE FAVORED MODEL OF WPC AND THIS WARRANTS ONLY COSMETIC CHANGES TO THE EXTENDED FORECAST. OVERALL THE AMPLITUDE HAS DECREASED A BIT BUT STILL EXPECT THE HIGHEST POPS MONDAY AND MONDAY NIGHT AS THE MID AND LOW LEVEL FORCING IS COUPLED. RESIDUAL LOWER POPS ARE NOW ADVERTISED IN THE DAYS BEYOND MONDAY AND THIS SEEMS REASONABLE GIVING THE TREND TOWARD LOWER AMPLITUDE LEADING TO LOWER CONFIDENCE THE FRONT WILL CLEAR THE AREA. && .AVIATION /12Z FRIDAY THROUGH WEDNESDAY/... AS OF 18Z...RADAR IMAGERY SHOWS SCATTERED SHOWERS/T-STORMS DEVELOPING ALONG THE SEA BREEZE BOUNDARY THIS AFTN. HAVE INCLUDED VCSH FOR KFLO/KLBT AS LATEST HRRR RUNS SHOW MORE SHOWERS DEVELOPING INLAND LATER TODAY. OTHERWISE...VFR SHOULD PREVAIL WITH SCT/BKN CU AND SSE WINDS AOB 10 KTS. MOSTLY CLEAR CONDITIONS TONIGHT AND PLENTY OF LOW-LEVEL MOISTURE INDICATES FOG/STRATUS IS AGAIN LIKELY AFTER 06Z. SREF PROBS AND GUIDANCE SUGGEST IFR CIGS/VSBYS WILL BE MORE WIDESPREAD INLAND...SIMILAR TO WHAT OCCURRED THIS MORNING. TEMPO IFR IS ALSO QUITE POSSIBLE ALONG THE COAST...MOST LIKELY IN THE 09-12Z RANGE. FOG/STRATUS SHOULD LIFT SOON AFTER 12Z SATURDAY. EXTENDED OUTLOOK...EARLY MORNING MVFR/IFR CIGS/VSBYS POSSIBLE THROUGH SUNDAY. SLIGHT CHANCE OF SHOWERS INLAND ON SUNDAY...WITH BETTER PCPN CHANCES ACROSS THE CWA MONDAY AND TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM FRIDAY...A FAIRLY LARGE AREA OF SHOWERS 10-30 MILES INLAND FROM THE COAST HAS KEPT INLAND TEMPERATURES A FEW DEGREES COOLER THAN EXPECTED...AND THIS HAS DELAYED THE INTENSIFICATION OF THE SEABREEZE BY A FEW HOURS. SOUTHEAST WINDS SHOULD STILL INCREASE TO A SOLID 10-12 KNOTS WITH GUSTS TOWARD 15 KNOTS IN THE NEXT COUPLE OF HOURS. NO OTHER SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FROM 1030 AM FOLLOWS... BERMUDA HIGH PRESSURE WELL OFFSHORE CONTINUES TO EXTEND A RIDGE AXIS ACROSS THE CAROLINAS WITH LIGHT ONSHORE WINDS THE RESULT. MUCH LIKE YESTERDAY...MODEST MARINE-TO-INLAND TEMPERATURE CONTRASTS WILL FUEL A WEAK SEABREEZE WITH WIND SPEEDS NEARSHORE INCREASING TO 12-14 KNOTS. SHOWERS OUT TOWARD 40 MILES FROM SHORE AND NEW SHOWERS DEVELOPING JUST INLAND FROM THE BEACHES SHOULD AVOID THE COASTAL WATERS THROUGH THE DAY...WITH MAINLY SUNNY SKIES EXPECTED. SEAS AVERAGE 2.5 TO 3 FEET ON THE BUOYS NEAR CAPE FEAR THIS MORNING...WITH WAVE ENERGY EQUALLY SPLIT BETWEEN 6 AND 9 SECOND PERIODS. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 245 AM FRIDAY...BERMUDA HIGH PRESSURE CIRCULATION WILL BRING SEAS AROUND THREE FEET IN 7-8 SECOND INTERVALS. SOME ACCELERATION AND SLIGHTLY CHOPPIER SEAS CAN BE EXPECTED EACH AFTERNOON CLOSER TO SHORE VIA THE SEA BREEZE. LONG TERM /MONDAY THROUGH TUESDAY/... AS OF 245 AM FRIDAY...SOUTH TO SOUTHWESTERLY WINDS THROUGH MOST OF THE PERIOD AS THE WIND SHIFT ASSOCIATED WITH THE FRONT WILL TAKE SOME TIME TO OCCUR. BY WEDNESDAY MORNING EXPECT A WEAK NORTHEASTERLY FLOW TO BE IN PLACE. CERTAINLY NO STRONG PUSH OF COLD AIR BEHIND THE FRONT AND OVERALL EXPECT WINDS TO BE IN A 10-15 KNOT RANGE. SIGNIFICANT SEAS REMAIN IN A 2-3 FOOT RANGE A SLIGHT DECREASE FROM EARLIER FORECASTS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...SHK LONG TERM...SHK AVIATION...BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1220 PM EDT FRI MAY 31 2013 .SYNOPSIS... A COLD FRONT WILL SLOWLY APPROACH FROM THE WEST THIS WEEKEND...THEN CROSS THE REGION SUNDAY NIGHT THROUGH MONDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1130 AM FRIDAY... OVERVIEW: AN UPPER LEVEL RIDGE CENTERED ALONG THE SOUTHEAST AND MID-ATLANTIC COAST WILL FURTHER WEAKEN THROUGH TONIGHT AS AN UPPER LEVEL LOW CENTERED OVER THE NORTHERN PLAINS MOVES SLOWLY EAST INTO THE NORTHERN MS RIVER VALLEY. A SFC-H85 RIDGE WILL PERSIST OFFSHORE OF THE CAROLINAS...WITH AN INCREASINGLY MOIST SOUTHERLY RETURN FLOW ACROSS THE REGION. TEMPERATURES: HIGHS TODAY APPEAR VERY SIMILAR TO THE PREVIOUS FEW DAYS GIVEN LITTLE CHANGE IN THICKNESSES AND A VERY SIMILAR (ALBEIT INCREASINGLY MOIST) AIRMASS. THE MAIN FACTORS W/REGARD TO HIGH TEMPS ARE APT TO BE THE SEABREEZE APPROACHING FROM THE S/SE AND ISOLD CONVECTION /OUTFLOW/ EXPECTED DURING THE MID TO LATE AFTERNOON...PRIMARILY EAST OF HWY 1 AND SOUTH OF HWY 64 (SANDHILL/SE COASTAL PLAIN) WHERE THE SEABREEZE PASSAGE WILL OCCUR THE EARLIEST...THOUGH EVEN IN THOSE AREAS DIURNAL HEATING MAY BE SUFFICIENT FOR TEMPS TO REACH THE UPPER 80S. WITH THE ABOVE IN MIND...WILL INDICATE HIGHS IN THE MID/UPPER 80S...WARMEST IN VICINITY OF HWY 1. EXPECT LOWS TONIGHT SLIGHTLY WARMER THAN LAST NIGHT DUE TO INCREASED BOUNDARY LAYER MOISTURE... IN THE MID/UPPER 60S. CONVECTION: WEAK BUT PERSISTENT SOUTHERLY RETURN FLOW WILL ADVECT AN INCREASINGLY MOIST AIRMASS FROM THE ATLANTIC INTO CENTRAL NC... CHARACTERIZED BY SFC DEWPOINTS IN THE MID/UPPER 60S...H925 DEWPOINTS OF 13-15C AND H85 DEWPOINTS OF 10-12C DURING THE MID/LATE AFTERNOON HOURS. MID-LEVEL LAPSE RATES HAVE DECREASED IN COMPARISON TO YESTERDAY AS THE RIDGE ALOFT WEAKENS...AND THE LATEST RAP GUIDANCE SUGGEST H7-H5 LAPSE RATES ON THE ORDER OF 5.5-6.5 C/KM DURING PEAK HEATING...STEEPEST IN THE EAST. IN THIS ENVIRONMENT...EXPECT MODERATE DESTABILIZATION WITH MLCAPE VALUES OF 1000-1500 J/KG BY PEAK HEATING AND LITTLE OR NO CIN. FORCING WILL LARGELY BE LIMITED TO CONVERGENCE ALONG THE SEABREEZE THIS AFTERNOON...THOUGH LATEST WV IMAGERY AND RAP DATA SUGGEST A WEAK N-S ORIENTED H3 SHEAR AXIS OVER THE SOUTHERN APPALACHIANS SHOULD PROGRESS SLOWLY EAST INTO THE WESTERN PIEDMONT BY 21-00Z. WITH THE ABOVE IN MIND...EXPECT A MORE ACTIVE SEABREEZE THAN YESTERDAY...WITH ISOLD TO SCT SHOWERS AND STORMS BETWEEN BY MID/LATE AFTERNOON...PRIMARILY SOUTH OF HWY 64 ACROSS THE EASTERN SANDHILLS AND SE COASTAL PLAIN...WITH ACTIVITY WANING IN VICINITY OF THE TRIANGLE OR HWY 1 CORRIDOR BY OR SHORTLY AFTER SUNSET. CONVECTION WILL REMAIN DISORGANIZED GIVEN NEGLIGIBLE DEEP-LAYER SHEAR UNDER THE WEAKENING RIDGE...THOUGH MODERATE DCAPE (~1000 J/KG) WOULD SUGGEST SOME POTENTIAL FOR ENHANCED COLD POOLS AND PERHAPS AN ISOLD DOWNBURST...PRIMARILY ACROSS SCOTLAND...HOKE... CUMBERLAND...SAMPSON AND WAYNE COUNTIES BETWEEN 19-23Z. -VINCENT && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY... SATURDAY/SATURDAY NIGHT... WHILE HEIGHTS ALOFT BEGIN TO FALL EVER SO SLIGHTLY AHEAD OF THE UPPER TROUGH MOVING INTO THE MID WEST STATES...THE MID-LEVEL RIDGE OVER THE WESTERN ATLANTIC WILL REMAIN DOMINATE AS IT EXTENDS ACROSS CENTRAL NC SATURDAY. THUS...EXPECT ANOTHER DAY OF AFTERNOON HIGHS IN THE MID TO UPPER 80S AND ISOLATED SHOWERS POSSIBLE ALONG THE SEABREEZE. MOISTURE TRANSPORT WILL BEGIN TO INCREASE ACROSS WESTERN NC SATURDAY NIGHT AS THE MID-LEVEL RIDGE EASES EASTWARD. EXPECT A FEW SHOWERS MAY BE POSSIBLE WEST OF THE YADKIN-RIVER...BUT WILL PLAN TO KEEP THE RAH CWA DRY THROUGH 12Z...AWAITING THE ARRIVAL OF STRONGER LOW-LEVEL FLOW AND DIURNAL HEATING. -SMITH FOR SUNDAY/SUNDAY NIGHT: THE SLIGHTLY WEAKENING MID LEVEL TROUGH AXIS APPROACHES OUR AREA FROM THE WEST... WITH MODELS DEPICTING A WEAK PERTURBATION RIDING TO THE NORTHEAST UP THROUGH THE WRN/CENTRAL CAROLINAS LATE SUNDAY INTO SUNDAY NIGHT... AS UPPER DIVERGENCE INCREASES IN THE RIGHT ENTRANCE REGION OF A ST LAWRENCE VALLEY JET. AS THE COLD FRONT APPROACHES FROM THE WEST... HIGH PRECIP WATER (150-200% OF NORMAL) IS EXPECTED TO SURGE NORTHEASTWARD OVER WRN NC SUNDAY AND INTO CENTRAL NC SUNDAY EVENING/NIGHT... ACCOMPANIED BY INCREASING LOW LEVEL MOISTURE TRANSPORT. THE 50 KT LOW LEVEL JET RIDES TO OUR NW ALONG THE CENTRAL APPALACHIANS EARLY SUNDAY BEFORE SHIFTING UP INTO THE CANADIAN MARITIMES... LEAVING A MUCH MORE SUBDUED 25-30 KT LOW LEVEL SPEED MAX FROM THE NRN PIEDMONT TO COASTAL NEW ENGLAND... SO THE DYNAMIC FORCING FOR ASCENT AS WELL AS THE KINEMATICS WILL GENERALLY BE RAMPING DOWN WITH MINIMAL DPVA. INSTABILITY IS MARGINAL AS WELL WITH MODELS DEPICTING BRIEF MUCAPE OF 1000-1500 J/KG OVER THE WRN CWA LATE SUNDAY WHILE THE SREF SHOWS VERY LOW PROBABILITIES OF MLCAPE OVER 1000 J/KG AT ANY TIME... LIKELY DUE IN PART TO WEAK MID LEVEL LAPSE RATES LESS THAN 6 C/KM. BUT THE INCREASE IN MOISTURE AND WHAT WEAK LIFT THERE IS STILL SEEMS TO SUPPORT CHANCE TO LOW-END LIKELY POPS SPREADING INTO AREAS WEST OF HIGHWAY 1 LATE AFTERNOON AND THROUGH THE NIGHT. WILL ADJUST TO BRING POPS EASTWARD A BIT LATER TO FIT WITH THE LATEST GUIDANCE TIMING BUT WILL RETAIN THE GENERAL FLAVOR OF THE EARLIER FORECAST. HIGHS 83-90... A LEAN TOWARD THE WARMER GFS-BASED STATISTICAL GUIDANCE. ABOVE-GUIDANCE LOWS OF 68-72 WITHIN A PREFRONTAL WARM AIR ADVECTION PATTERN. -GIH && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 245 AM FRIDAY... FOR MONDAY/MONDAY NIGHT: BEST CHANCE OF SHOWERS/STORMS STILL LOOKS TO BE IN THIS TIME FRAME. AS A STRONG VORTEX MOVES FROM SE ONTARIO ACROSS SRN QUEBEC... THE WEAK SOUTHERN END OF THE TRAILING MID LEVEL TROUGH EASES EASTWARD THROUGH THE AREA... ACCOMPANIED BY THE SURFACE FRONT AND PRECEDED BY THE MINOR LOBE OF VORTICITY WHICH TRAVERSES CENTRAL/ERN NC. THE ASCENT WILL BE ROOTED IN THE MID-UPPER LEVELS WITH ONLY VERY WEAK MASS CONVERGENCE NEAR THE GROUND... BUT WITH LIFT POTENTIALLY AUGMENTED BY 1000-1500 J/KG OF MLCAPE (FROM THE GFS AND ECMWF)... IT SHOULD BE STRONG ENOUGH WITH THE EXPECTED DEEP MOISTURE FOR LIKELY POPS AREAWIDE MONDAY... SLOWLY DECREASING WEST TO EAST IN THE WEST MONDAY NIGHT BUT REMAINING LIKELY IN THE EAST. CONFIDENCE IS HIGH THAT A PERIOD OF CATEGORICAL POPS WILL BE NEEDED ONCE WE GET CLOSER AND CAN PIN DOWN TIMING A BIT BETTER. COULD SEE UP TO AN INCH OF STORM-TOTAL RAIN BASED ON PRECIP WATER NEARING 2.0 INCHES AND A DEEP LCL-TO-0C LAYER AROUND 4 KM. HIGHS 77-84. LOWS FROM 62 NW TO NEAR 70 SE. FOR TUESDAY THROUGH THURSDAY: THE MID LEVEL SHEAR AXIS IS EXPECTED TO SHIFT OFFSHORE BY TUESDAY MORNING WITH THE SURFACE FRONT DRIFTING EASTWARD TO THE COASTAL AREA. THE ECMWF`S TROUGH IS NOTABLY WEAKER AND MORE BAGGY THAN THE GFS`S... AND AS A RESULT THE ECMWF IS MUCH SLOWER WITH THE FRONT... HANGING IT BACK FARTHER WEST... MEANING CONTINUED WARM AIR/HIGH HUMIDITY AND RAIN CHANCES OVER ALL BUT THE NW CWA. THINK THE ECMWF MAY BE ONTO SOMETHING GIVEN THAT THE STRONGEST MID LEVEL FLOW WITH THE EASTERN CANADA LOW WILL HOLD NORTH OF THE MASON-DIXON LINE. WILL HOLD ONTO AT LEAST CHANCE POPS FOR SHOWERS SOUTH AND EAST OF RALEIGH THROUGH TUESDAY... WITH MORE CLOUDS AND HIGHER DEW POINTS IN THE MID-UPPER 60S. THE QUEBEC VORTEX LIFTS UP ACROSS ERN CANADA WHILE A SECOND LOW CROSSES THE DAKOTAS TUESDAY NIGHT BEFORE SETTLING OVER THE UPPER MIDWEST THROUGH MIDWEEK. FOR TUESDAY NIGHT THROUGH THURSDAY WE SHOULD BE UNDER THE INFLUENCE OF THE CANADIAN SURFACE HIGH NOSING IN FROM THE NORTH BENEATH WEAK MAINLY WESTERLY MID LEVEL FLOW... YIELDING FAIR SKIES AND GENERALLY DRY CONDITIONS. THE RETURN EASTERLY FLOW AROUND THE SURFACE HIGH STRENGTHENS BY THURSDAY WITH INCREASING ATLANTIC INFLOW... AND THIS MAY RESULT IN A FEW SHOWERS OVER CENTRAL NC... BUT THE CHANCE FOR SUFFICIENTLY DEEP MOISTURE IS TOO UNCERTAIN FOR ANYTHING BUT SLIGHT CHANCE POPS FOR NOW. THICKNESSES SUPPORT TEMPS NEAR NORMAL SE AND BELOW NORMAL NW ON TUESDAY... DROPPING TO ABOUT A CATEGORY BELOW NORMAL FOR WEDNESDAY AND THURSDAY. -GIH && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 1220 PM FRIDAY... 24-HR TAF PERIOD: VFR CONDITIONS WITH CEILINGS BETWEEN 4000-5000 FT AGL WILL PREVAIL IN MOST AREAS THROUGH THIS EVENING...ASIDE FROM A CHANCE OF ISOLD SHOWERS AND STORMS BETWEEN 20-00Z...PRIMARILY AT THE FAY TERMINAL... THOUGH POSSIBLY AS FAR NORTH AS THE RDU/RWI TERMINALS PRIOR TO DISSIPATING. OVERNIGHT...EXPECT A GOOD POTENTIAL FOR IFR/LIFR STRATUS OR FOG AT ALL TERMINALS BETWEEN 07-13Z SAT...WITH ANY FOG/STRATUS LIFTING TO VFR BY MID SAT MORNING. VFR CONDITIONS WITH CEILINGS 4000-5000 FT AGL ARE EXPECTED DURING THE DAY SATURDAY. LOOKING AHEAD: MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG AND AHEAD OF A COLD FRONT PROGRESSING SLOWLY EAST THROUGH CENTRAL NC SUN NIGHT AND MONDAY...BEGINNING IN THE WESTERN PIEDMONT (INT/GSO TERMINALS) LATE SUNDAY AFT/EVE...EVENTUALLY ENDING FROM WEST TO EAST LATE MON INTO MON NIGHT. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...SMITH/HARTFIELD LONG TERM...HARTFIELD AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1130 AM EDT FRI MAY 31 2013 .SYNOPSIS... A COLD FRONT WILL SLOWLY APPROACH FROM THE WEST THIS WEEKEND...THEN CROSS THE REGION SUNDAY NIGHT THROUGH MONDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1130 AM FRIDAY... OVERVIEW: AN UPPER LEVEL RIDGE CENTERED ALONG THE SOUTHEAST AND MID-ATLANTIC COAST WILL FURTHER WEAKEN THROUGH TONIGHT AS AN UPPER LEVEL LOW CENTERED OVER THE NORTHERN PLAINS MOVES SLOWLY EAST INTO THE NORTHERN MS RIVER VALLEY. A SFC-H85 RIDGE WILL PERSIST OFFSHORE OF THE CAROLINAS...WITH AN INCREASINGLY MOIST SOUTHERLY RETURN FLOW ACROSS THE REGION. TEMPERATURES: HIGHS TODAY APPEAR VERY SIMILAR TO THE PREVIOUS FEW DAYS GIVEN LITTLE CHANGE IN THICKNESSES AND A VERY SIMILAR (ALBEIT INCREASINGLY MOIST) AIRMASS. THE MAIN FACTORS W/REGARD TO HIGH TEMPS ARE APT TO BE THE SEABREEZE APPROACHING FROM THE S/SE AND ISOLD CONVECTION /OUTFLOW/ EXPECTED DURING THE MID TO LATE AFTERNOON...PRIMARILY EAST OF HWY 1 AND SOUTH OF HWY 64 (SANDHILL/SE COASTAL PLAIN) WHERE THE SEABREEZE PASSAGE WILL OCCUR THE EARLIEST...THOUGH EVEN IN THOSE AREAS DIURNAL HEATING MAY BE SUFFICIENT FOR TEMPS TO REACH THE UPPER 80S. WITH THE ABOVE IN MIND...WILL INDICATE HIGHS IN THE MID/UPPER 80S...WARMEST IN VICINITY OF HWY 1. EXPECT LOWS TONIGHT SLIGHTLY WARMER THAN LAST NIGHT DUE TO INCREASED BOUNDARY LAYER MOISTURE... IN THE MID/UPPER 60S. CONVECTION: WEAK BUT PERSISTENT SOUTHERLY RETURN FLOW WILL ADVECT AN INCREASINGLY MOIST AIRMASS FROM THE ATLANTIC INTO CENTRAL NC... CHARACTERIZED BY SFC DEWPOINTS IN THE MID/UPPER 60S...H925 DEWPOINTS OF 13-15C AND H85 DEWPOINTS OF 10-12C DURING THE MID/LATE AFTERNOON HOURS. MID-LEVEL LAPSE RATES HAVE DECREASED IN COMPARISON TO YESTERDAY AS THE RIDGE ALOFT WEAKENS...AND THE LATEST RAP GUIDANCE SUGGEST H7-H5 LAPSE RATES ON THE ORDER OF 5.5-6.5 C/KM DURING PEAK HEATING...STEEPEST IN THE EAST. IN THIS ENVIRONMENT...EXPECT MODERATE DESTABILIZATION WITH MLCAPE VALUES OF 1000-1500 J/KG BY PEAK HEATING AND LITTLE OR NO CIN. FORCING WILL LARGELY BE LIMITED TO CONVERGENCE ALONG THE SEABREEZE THIS AFTERNOON...THOUGH LATEST WV IMAGERY AND RAP DATA SUGGEST A WEAK N-S ORIENTED H3 SHEAR AXIS OVER THE SOUTHERN APPALACHIANS SHOULD PROGRESS SLOWLY EAST INTO THE WESTERN PIEDMONT BY 21-00Z. WITH THE ABOVE IN MIND...EXPECT A MORE ACTIVE SEABREEZE THAN YESTERDAY...WITH ISOLD TO SCT SHOWERS AND STORMS BETWEEN BY MID/LATE AFTERNOON...PRIMARILY SOUTH OF HWY 64 ACROSS THE EASTERN SANDHILLS AND SE COASTAL PLAIN...WITH ACTIVITY WANING IN VICINITY OF THE TRIANGLE OR HWY 1 CORRIDOR BY OR SHORTLY AFTER SUNSET. CONVECTION WILL REMAIN DISORGANIZED GIVEN NEGLIGIBLE DEEP-LAYER SHEAR UNDER THE WEAKENING RIDGE...THOUGH MODERATE DCAPE (~1000 J/KG) WOULD SUGGEST SOME POTENTIAL FOR ENHANCED COLD POOLS AND PERHAPS AN ISOLD DOWNBURST...PRIMARILY ACROSS SCOTLAND...HOKE... CUMBERLAND...SAMPSON AND WAYNE COUNTIES BETWEEN 19-23Z. -VINCENT && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 AM FRIDAY... SATURDAY/SATURDAY NIGHT... WHILE HEIGHTS ALOFT BEGIN TO FALL EVER SO SLIGHTLY AHEAD OF THE UPPER TROUGH MOVING INTO THE MID WEST STATES...THE MID-LEVEL RIDGE OVER THE WESTERN ATLANTIC WILL REMAIN DOMINATE AS IT EXTENDS ACROSS CENTRAL NC SATURDAY. THUS...EXPECT ANOTHER DAY OF AFTERNOON HIGHS IN THE MID TO UPPER 80S AND ISOLATED SHOWERS POSSIBLE ALONG THE SEABREEZE. MOISTURE TRANSPORT WILL BEGIN TO INCREASE ACROSS WESTERN NC SATURDAY NIGHT AS THE MID-LEVEL RIDGE EASES EASTWARD. EXPECT A FEW SHOWERS MAY BE POSSIBLE WEST OF THE YADKIN-RIVER...BUT WILL PLAN TO KEEP THE RAH CWA DRY THROUGH 12Z...AWAITING THE ARRIVAL OF STRONGER LOW-LEVEL FLOW AND DIURNAL HEATING. -SMITH FOR SUNDAY/SUNDAY NIGHT: THE SLIGHTLY WEAKENING MID LEVEL TROUGH AXIS APPROACHES OUR AREA FROM THE WEST... WITH MODELS DEPICTING A WEAK PERTURBATION RIDING TO THE NORTHEAST UP THROUGH THE WRN/CENTRAL CAROLINAS LATE SUNDAY INTO SUNDAY NIGHT... AS UPPER DIVERGENCE INCREASES IN THE RIGHT ENTRANCE REGION OF A ST LAWRENCE VALLEY JET. AS THE COLD FRONT APPROACHES FROM THE WEST... HIGH PRECIP WATER (150-200% OF NORMAL) IS EXPECTED TO SURGE NORTHEASTWARD OVER WRN NC SUNDAY AND INTO CENTRAL NC SUNDAY EVENING/NIGHT... ACCOMPANIED BY INCREASING LOW LEVEL MOISTURE TRANSPORT. THE 50 KT LOW LEVEL JET RIDES TO OUR NW ALONG THE CENTRAL APPALACHIANS EARLY SUNDAY BEFORE SHIFTING UP INTO THE CANADIAN MARITIMES... LEAVING A MUCH MORE SUBDUED 25-30 KT LOW LEVEL SPEED MAX FROM THE NRN PIEDMONT TO COASTAL NEW ENGLAND... SO THE DYNAMIC FORCING FOR ASCENT AS WELL AS THE KINEMATICS WILL GENERALLY BE RAMPING DOWN WITH MINIMAL DPVA. INSTABILITY IS MARGINAL AS WELL WITH MODELS DEPICTING BRIEF MUCAPE OF 1000-1500 J/KG OVER THE WRN CWA LATE SUNDAY WHILE THE SREF SHOWS VERY LOW PROBABILITIES OF MLCAPE OVER 1000 J/KG AT ANY TIME... LIKELY DUE IN PART TO WEAK MID LEVEL LAPSE RATES LESS THAN 6 C/KM. BUT THE INCREASE IN MOISTURE AND WHAT WEAK LIFT THERE IS STILL SEEMS TO SUPPORT CHANCE TO LOW-END LIKELY POPS SPREADING INTO AREAS WEST OF HIGHWAY 1 LATE AFTERNOON AND THROUGH THE NIGHT. WILL ADJUST TO BRING POPS EASTWARD A BIT LATER TO FIT WITH THE LATEST GUIDANCE TIMING BUT WILL RETAIN THE GENERAL FLAVOR OF THE EARLIER FORECAST. HIGHS 83-90... A LEAN TOWARD THE WARMER GFS-BASED STATISTICAL GUIDANCE. ABOVE-GUIDANCE LOWS OF 68-72 WITHIN A PREFRONTAL WARM AIR ADVECTION PATTERN. -GIH && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 245 AM FRIDAY... FOR MONDAY/MONDAY NIGHT: BEST CHANCE OF SHOWERS/STORMS STILL LOOKS TO BE IN THIS TIME FRAME. AS A STRONG VORTEX MOVES FROM SE ONTARIO ACROSS SRN QUEBEC... THE WEAK SOUTHERN END OF THE TRAILING MID LEVEL TROUGH EASES EASTWARD THROUGH THE AREA... ACCOMPANIED BY THE SURFACE FRONT AND PRECEDED BY THE MINOR LOBE OF VORTICITY WHICH TRAVERSES CENTRAL/ERN NC. THE ASCENT WILL BE ROOTED IN THE MID-UPPER LEVELS WITH ONLY VERY WEAK MASS CONVERGENCE NEAR THE GROUND... BUT WITH LIFT POTENTIALLY AUGMENTED BY 1000-1500 J/KG OF MLCAPE (FROM THE GFS AND ECMWF)... IT SHOULD BE STRONG ENOUGH WITH THE EXPECTED DEEP MOISTURE FOR LIKELY POPS AREAWIDE MONDAY... SLOWLY DECREASING WEST TO EAST IN THE WEST MONDAY NIGHT BUT REMAINING LIKELY IN THE EAST. CONFIDENCE IS HIGH THAT A PERIOD OF CATEGORICAL POPS WILL BE NEEDED ONCE WE GET CLOSER AND CAN PIN DOWN TIMING A BIT BETTER. COULD SEE UP TO AN INCH OF STORM-TOTAL RAIN BASED ON PRECIP WATER NEARING 2.0 INCHES AND A DEEP LCL-TO-0C LAYER AROUND 4 KM. HIGHS 77-84. LOWS FROM 62 NW TO NEAR 70 SE. FOR TUESDAY THROUGH THURSDAY: THE MID LEVEL SHEAR AXIS IS EXPECTED TO SHIFT OFFSHORE BY TUESDAY MORNING WITH THE SURFACE FRONT DRIFTING EASTWARD TO THE COASTAL AREA. THE ECMWF`S TROUGH IS NOTABLY WEAKER AND MORE BAGGY THAN THE GFS`S... AND AS A RESULT THE ECMWF IS MUCH SLOWER WITH THE FRONT... HANGING IT BACK FARTHER WEST... MEANING CONTINUED WARM AIR/HIGH HUMIDITY AND RAIN CHANCES OVER ALL BUT THE NW CWA. THINK THE ECMWF MAY BE ONTO SOMETHING GIVEN THAT THE STRONGEST MID LEVEL FLOW WITH THE EASTERN CANADA LOW WILL HOLD NORTH OF THE MASON-DIXON LINE. WILL HOLD ONTO AT LEAST CHANCE POPS FOR SHOWERS SOUTH AND EAST OF RALEIGH THROUGH TUESDAY... WITH MORE CLOUDS AND HIGHER DEW POINTS IN THE MID-UPPER 60S. THE QUEBEC VORTEX LIFTS UP ACROSS ERN CANADA WHILE A SECOND LOW CROSSES THE DAKOTAS TUESDAY NIGHT BEFORE SETTLING OVER THE UPPER MIDWEST THROUGH MIDWEEK. FOR TUESDAY NIGHT THROUGH THURSDAY WE SHOULD BE UNDER THE INFLUENCE OF THE CANADIAN SURFACE HIGH NOSING IN FROM THE NORTH BENEATH WEAK MAINLY WESTERLY MID LEVEL FLOW... YIELDING FAIR SKIES AND GENERALLY DRY CONDITIONS. THE RETURN EASTERLY FLOW AROUND THE SURFACE HIGH STRENGTHENS BY THURSDAY WITH INCREASING ATLANTIC INFLOW... AND THIS MAY RESULT IN A FEW SHOWERS OVER CENTRAL NC... BUT THE CHANCE FOR SUFFICIENTLY DEEP MOISTURE IS TOO UNCERTAIN FOR ANYTHING BUT SLIGHT CHANCE POPS FOR NOW. THICKNESSES SUPPORT TEMPS NEAR NORMAL SE AND BELOW NORMAL NW ON TUESDAY... DROPPING TO ABOUT A CATEGORY BELOW NORMAL FOR WEDNESDAY AND THURSDAY. -GIH && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 700 AM FRIDAY... IFR/LIFR CONDITIONS ACROSS THE COASTAL PLAIN THIS MORNING HAS FOR THE MOST REMAINED JUST TO THE EAST OF KRWI AND KFAY...THOUGH THE STRATUS APPEARS TO ADVANCING NORTHWARD IN SOME AREAS. HAVE INCLUDED A TEMPO AT THOSE SITES THROUGH 13Z. OTHERWISE...VFR CONDITIONS SHOULD PREVAIL BY 14Z...WITH JUST A LIGHT SOUTHERLY WIND AND SCATTERED CU THIS AFTERNOON. THERE IS A SMALL CHANCE OF A SHOWER...MAINLY NEAR KFAY AFTER 18Z...AS THE SEABREEZE PUSHES INLAND. EXPECT STRATUS AND FOG TO DEVELOP AGAIN TONIGHT BY BY 09Z...WITH THE HIGHEST CONFIDENCE FROM KRDU SOUTH AND EAST. OUTLOOK... VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR MUCH OF THE WEEKEND...WITH EARLY MORNING STRATUS/FOG POSSIBLE AGAIN SUNDAY. A FEW ISOLATED SHOWERS/STORMS WILL BE POSSIBLE EACH AFTERNOON...MOSTLY NEAR KFAY. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG AND AHEAD OF A COLD FRONT EXPECTED TO PROGRESS SLOWLY EASTWARD THROUGH CENTRAL NC SUNDAY NIGHT THROUGH MONDAY NIGHT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...SMITH/HARTFIELD LONG TERM...HARTFIELD AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
956 PM EDT SAT JUN 1 2013 .SYNOPSIS... WARM SECTOR THROUGH TONIGHT WITH CONVECTION POSSIBLE ESPECIALLY LATE THIS AFTERNOON AND EVENING. COLD FRONT CROSSES SUNDAY INTO MONDAY. COOLER AND DRIER TO START NEXT WEEK. WARM FRONT THURSDAY. && .NEAR TERM /THROUGH SUNDAY/... WITH LOSS OF SUNSHINE...LOW-LEVEL AIRMASS HAS BEGUN TO BECOME LESS UNSTABLE. THIS HAS BEEN SEEN IN THE STORMS IN OUR REGION DECREASING IN INTENSITY. HOWEVER...A LINE OF STORMS HAS DEVELOPED TO OUR WEST AND NORTHWEST. EXPECT THIS LINE WILL GRADUALLY MOVE EAST WITH TIME AND HAVE ADJUSTED ONSET OF LIKELY AND HIGHER POPS TO REFLECT THIS THINKING. OTHERWISE...ONLY TWEAKS MADE. PREVIOUS DISCUSSION... PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND SHOWERS/THUNDERSTORM CHANCES AS WELL AS POTENTIAL FOR SEVERE WEATHER. REGARDING THUNDERSTORMS THIS AFTERNOON/EVENING...15Z REGIONAL RADAR IMAGERY AND SFC OBS CONTINUE TO SHOW ONGOING WIDESPREAD PRECIP...MAINLY IN THE FORM OF SHOWERS...FROM WESTERN OHIO SW-WARD DOWN THE EXTENT OF THE OHIO RIVER INTO WESTERN TENN/ARKANSAS RESULTANT OF STRONG OVERNIGHT CONVECTION. SFC TEMPS IN WHAT APPEARED YESTERDAY TO BE THE FAVORED AREAS OF THUNDERSTORMS AND SUBSEQUENT SVR WX INITIATION STILL ONLY IN THE MID/UPPER 60S GENERALLY...WITH NO LIGHTNING STRIKES CURRENTLY. SHOULD PRECIP/CLOUDS HANG ON OVER THAT AREA...STRONGER STORMS MAY WAIT TO FORM FURTHER EAST OVER CENTRAL OHIO AND POINTS SOUTHWEST WHERE SFC TEMPS HAVE WARMED TO THE UPPER 70S/LOW 80S DESPITE FAIRLY DENSE HIGH CLOUD COVER. GOOD DYNAMICS ARRIVE BY 21Z WHICH CONTINUE INTO THE EVENING...PARTICULARLY OVER THE WESTERN ZONES WHERE 30-40KTS OF SHEAR IN PLACE. WITH THE FRONT STILL WELL TO THE WEST HOWEVER...TOUGH CALL ON DETERMINING A TRIGGERING MECHANISM. A VORT MAX PER LATEST RUC13 PROGGED TO PUSH NE-WARD THROUGH CENTRAL KY BY 21Z-00Z MAY BE ENOUGH TO GET THINGS GOING. DO FEEL THAT THUNDERSTORMS WILL SLOWLY BEGIN TO FORM BY THE MID/LATE AFTERNOON HOURS AT FIRST RELATIVELY UNORGANIZED...WITH A GRADUAL INCREASE FROM THE WEST BY AND AFTER 00Z SUN. AS USUAL...IT APPEARS TO BE A RACE BETWEEN STORM DEVELOPMENT AND LOSS OF DAYTIME PEAK INSTABILITY. BUT IN THE END...SOME STORMS MAY BECOME STRONG TO SEVERE MAINLY ACROSS THE FAR WESTERN ZONES CLOSER TO THE OHIO RIVER BUT THE THREAT APPEARS MARGINAL AT BEST. STRONG WINDS APPEAR TO BE THE MAIN HAZARD WITH DCAPE VALS OVER 1K J/KG JUST TO THE SOUTHWEST OF THE FORECAST AREA BUT EL/S ARE SUFFICIENTLY TALL FOR SOME LARGE HAIL. LITTLE CHANGE FROM PREV FORECAST WITH REGARD TO THE REMAINDER OF THE OVERNIGHT HOURS. A MORE GENERAL CONVECTIVE RAINFALL WITH SOME THUNDER PERHAPS WILL PUSH INTO THE AREA WITH GOOD DEEP LAYER MOISTURE AND A PREFRONTAL TROUGH-TYPE FEATURE. STILL EXPECTING ROUGHLY A HALF-INCH OR SO ACROSS THE AREA...AND SOME LOCALIZED WATER ISSUES COULD BE POSSIBLE SHOULD HEAVY SHOWERS/STORMS PASS OVER THE SAME LOCATION BUT NOTHING WIDESPREAD EXPECTED. SUNDAY...AGAIN LITTLE CHANGE FROM PREV FCST WITH THE MAIN AXIS OF DEEP MOISTURE PUSHING ACROSS DURING THE MORNING HOURS WITH HIGH CHANCE POPS CONFINED MAINLY TO CKB-CRW AND POINTS EAST BY 18Z. ACTUAL COLD FRONT HOWEVER STILL LAGS WELL BEHIND AND ONLY ENTERING THE NW ZONES BY END OF THE PERIOD. INHERITED MAX TEMPS AROUND 80 FOR LOWLANDS STILL LOOK ON TRACK. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... GFS/ECMWF SHOW COLD FRONT OVER THE OH RIVER BY 00Z MONDAY. SHOWERS AND STORMS WILL BE POSSIBLE ALONG THE FRONT...DIMINISHING IN INTENSITY AND COVERAGE BY EARLY MONDAY MORNING. THE FRONT BRINGS A WIND SHIFT FROM THE NORTHWEST ALOFT MONDAY NIGHT...WHILE AT THE SFC COULD BECOME LIGHT AND VARIABLE...OR CALM. THEN...FLOW BECOMES NORTHERLY LATER MONDAY AND MONDAY NIGHT TO BRING COOLER TEMPERATURES...MILD AFTERNOON...AND RELATIVELY COLDER NIGHTS ARE EXPECTED THROUGH TUESDAY NIGHT. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... WEAK SEMI ZONAL FLOW ALOFT AND NO VORT MAX FROM SHORTWAVES SUGGEST BROAD HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH EARLY THURSDAY. THIS WILL CONTINUE TO CLEARING CONDITIONS...EXCEPT FOR LOW LEVEL DIURNAL CU DURING THE AFTERNOON HOURS. NEAR NORMAL TEMPERATURES EXPECTED THURSDAY ON. TWEAKED DOWN WPC TEMPERATURE A BIT. A WARM FRONTAL BOUNDARY FORMS ACROSS OH INTO SOUTHEAST OH THURSDAY...UNDER SOUTHERLY FLOW. THE SOUTHERLY WINDS WILL ALSO RESULT IN INCREASING LOW-LEVEL MOISTURE AND THE CHANCES FOR SHOWERS AND STORMS...MAINLY DIURNAL IN NATURE...WILL ALSO RETURN THROUGH THE REMAINDER OF THE PERIOD. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... 00Z SUNDAY THRU 00Z MONDAY... BAND OF CONVECTION WELL AHEAD OF A COLD FRONT WILL SLOWLY MOVE EASTWARD AND REACH THE OHIO RIVER BY 06Z SUNDAY...THE I79 CORRIDOR BY 09Z...AND THE MOUNTAINS BY 12Z. OUTSIDE OF THIS RAIN...EXPECT VFR CONDITIONS WILL PREVAIL. GENERALLY MVFR CONDITIONS IN THIS RAIN...WITH AN EMBEDDED THUNDERSTORM POSSIBLE. WILL USE VCTS IN TAFS. THE SHOWERS AND THUNDERSTORMS SHOULD DECREASE FROM THE WEST AFTER 12Z...WITH ONLY A FEW STORMS EXPECTED ACROSS THE LOWLANDS AFTER 19Z. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: TIMING OF BAND OF CONVECTION LATER PART OF PERIOD MAY VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE SUN 06/02/13 UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09 CRW CONSISTENCY H H H H H H H H H M M M HTS CONSISTENCY H H H H H H M M M M M M BKW CONSISTENCY H H H H H H H H H M M M EKN CONSISTENCY H H H H H H H H H M M M PKB CONSISTENCY H H H H H H H M M M M M CKB CONSISTENCY H H H H H H H H H M M M AFTER 00Z MONDAY... IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS SUNDAY NIGHT...AND IN POST-RAIN FOG SUNDAY NIGHT INTO MONDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...JSH/50 SHORT TERM...ARJ LONG TERM...ARJ AVIATION...JSH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
810 PM EDT SAT JUN 1 2013 .SYNOPSIS... WEATHER SYSTEM OVER THE WESTERN GREAT LAKES WILL SHIFT EASTWARD TONIGHT...DRAGGING A COLD FRONT THROUGH THE OHIO VALLEY LATER TONIGHT AND SUNDAY. THIS WILL PROMPT SEVERAL ROUNDS OF SHOWERS AND STORMS FOR THE AREA...BEFORE A DRYING TREND TAKES HOLD FOR SUNDAY NIGHT...LASTING INTO THE MIDDLE OF NEXT WEEK. A COOLER AND DRIER AIRMASS WILL DOMINATE THROUGH THIS TIME PERIOD. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... STILL WORKING SOME DECENT UPDRAFTS NORTHEAST THROUGH SOUTH-CENTRAL OHIO AND NORTHEAST KENTUCKY. A FEW STORM SPLITS...LEFT MOVING HAIL CORES...AND PERSISTENT WEAK/BROAD ROTATION HAVE BEEN NOTED WITH THE STRONGEST STORMS /PROMPTED ONE QUICK WARNING/. THESE WILL CONTINUE TO WORK RATHER BRISKLY OFF TO THE NORTHEAST AND WHILE A ROGUE SMALL HAIL/WIND GUST IS POSSIBLE...THINK THESE HAVE WEAKENED IN A GENERAL SENSE FOR THE EVENING. ATTENTION THEN TURNS TO THE STRONGER SYNOPTIC FORCING ENTERING CNTL/ERN IL CURRENTLY WITH AN ATTENDANT COLD FRONT. RECENT HRRR RUNS SIMPLY ADAMANT A WHOLE BUNCH OF SHOWERS/STORMS WILL DEVELOP ACROSS EASTERN IND/WRN OHIO IN A FEW HOURS...AND DON/T WANT TO TOTALLY DISCOUNT THIS AS IT HAS BEEN ONE OF THE FEW STEADIER SIGNALS IN THE HRRR THE LAST FEW HOURS. BUT LAST GLIMPSES OF SATELLITE VIS PICS OVER IND SHOW THAT THE STABLE AIRMASS IS INTACT AND VERY FEW AGITATED CUMULUS/ACCAS ARE EVIDENT. THERE SHOULD BE A MODEST RAMP-UP OF THE LOW LEVEL JET IMMEDIATELY DOWNSTREAM OF THE PV ANOMALY ROTATING THROUGH IL RIGHT NOW SO THE SYNOPTIC SIGNALS SAY TO STAY THE COURSE WITH HIGHER RAIN/STORM CHANCES BEGINNING VERY LATE THIS EVENING. EARLY LOOK AT THE 02.00Z KILN BALLOON DATA SUGGESTS INSTBY IS NOT IMPRESSIVE BUT WINDS/SHEAR CONTINUE TO BE FAVORABLE FOR STORM ORGANIZATION. HOWEVER...SPC MESOA DATA SUGGESTING THE DCAPE POOL HAS BEEN MODIFIED SOME AND NOW THE NEAR SFC SHALLOW INVERSION HAS BEGUN TO FORM PER OBS. SO WHILE A FEW SEVERE REPORTS ARE POSSIBLE OVERNIGHT...JUST NOT SEEING A GREAT SETUP AND THUS WILL TONE BACK HAZ WX OUTLOOK FOR THE OVERNIGHT PERIOD. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... SECONDARY WAVE ALOFT FINALLY ESCORTS THE TROUGH AXIS OUT OF THE AREA TOMORROW AND THIS ALLOWS A WEAK SECONDARY FRONT TO DEVELOP AND PUSH THROUGH DURING THE DAY. MAY BE A BROKEN BAND OF SHOWERS ALONG THIS FEATURE BY MID AFTERNOON...SO CARRIED THIS CHANCE FROM NW-SE ACROSS THE AREA DURING THE LATE MORNING INTO THE EARLY EVENING. MUCH COOLER/DRIER AIRMASS ARRIVES ON THE HEELS OF THIS FRONT AND MAKES FOR A COMFORTABLE SUNDAY NIGHT WITH LOWS DOWN INTO THE 50S UNDER CLEARING SKIES. && .LONG TERM /MONDAY THROUGH SATURDAY/... PERIOD BEGINS WITH HIGH PRESSURE CENTERED OVER THE UPPER MS VALLEY. THE HIGH WILL BUILD SE INTO THE LOWER GREAT LAKES THROUGH TUESDAY. HIGHS ON MONDAY WILL BE COOL...RANGING FROM THE UPPER 60S TO THE LOWER 70S WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR EARLY JUNE. TEMPERATURES WILL FALL INTO THE UPPER 40S TO LOWER 50S MONDAY NIGHT. 12Z MODELS HAVE COME IN A LITTLE WARMER FOR TUESDAY. SO TOOK A CONSENSUS FORECAST AND RAISED HIGHS FOR TUESDAY INTO THE LOWER TO MID 70S. ON WEDNESDAY THE SFC HIGH PRESSURE IS FORECAST TO SLIDE EAST. THE ECMWF IS THE QUICKEST WITH THE RETURN PCPN...BUT THE REMAINING MODELS KEEP THE FA DRY...SO LEANED TOWARDS THE MAJORITY. WEDNESDAY NIGHT INTO THURSDAY AS WRMFNT DEVELOPS OVER THE OH VLY... ATMOSPHERE BECOMES UNTIL STABLE AND IT LOOKS LIKE THERE WILL BE A CHANCE OF SCT TSRA. THU NGT INTO FRI...H5 WAVE SWINGS UP THE OH VLY ADDING EXTRA LIFT AND IT DRIVES A CDFNT ACROSS THE REGION KEEPING CHC OF CONVECTION IN THE FORECAST. DRIER AIR TRIES TO BUILD IN FOR SATURDAY. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... CONVECTIVE MODELS WERE ALL INDICATING DEVELOPMENT OF SHRA/TSRA AHEAD OF IMMEDIATE PREFRONTAL ACTIVITY CURRENTLY OVER IL. SOME MODELS STILL BRINGING THIS SOLUTION...BUT ANY ACTIVITY SHOULD BE WIDELY SCATTERED UNTIL THE MAIN LINE OF SHOWERS WITH EMBEDDED THUNDERSTORMS MAKING AN APPEARANCE AFTER 04Z. HIGH WIND THREAT DIMINISHED SO KEEPING WIND GUSTS MARGINAL. STILL POTENTIAL FOR SOME MVFR VSBYS WHERE EMBEDDED HEAVY RAIN OCCURS...WITH THE BEST POTENTIAL IN THE WEST BETWEEN 05-08Z AND 07-11Z IN THE EAST. CONVECTION OVER SOUTH CENTRAL OHIO WILL APPROACH KLCK/KCMH NEAR 02Z...BUT EXPECTATION IS FOR THE BEST ACTIVITY TO BE JUST EAST OF THE TERMINAL SITES. MVFR CIGS WITH THE PREFRONTAL ACTIVITY AS WELL AS WITH LINGERING SHRA AFTER 12Z SUN BEFORE LIFTING NEAR 00Z. OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU SHORT TERM...BINAU LONG TERM...SITES AVIATION...JDR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
757 PM EDT SAT JUN 1 2013 .SYNOPSIS... WEATHER SYSTEM OVER THE WESTERN GREAT LAKES WILL SHIFT EASTWARD TONIGHT...DRAGGING A COLD FRONT THROUGH THE OHIO VALLEY LATER TONIGHT AND SUNDAY. THIS WILL PROMPT SEVERAL ROUNDS OF SHOWERS AND STORMS FOR THE AREA...BEFORE A DRYING TREND TAKES HOLD FOR SUNDAY NIGHT...LASTING INTO THE MIDDLE OF NEXT WEEK. A COOLER AND DRIER AIRMASS WILL DOMINATE THROUGH THIS TIME PERIOD. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... STILL WORKING SOME DECENT UPDRAFTS NORTHEAST THROUGH SOUTH-CENTRAL OHIO AND NORTHEAST KENTUCKY. A FEW STORM SPLITS...LEFT MOVING HAIL CORES...AND PERSISTENT WEAK/BROAD ROTATION HAVE BEEN NOTED WITH THE STRONGEST STORMS /PROMPTED ONE QUICK WARNING/. THESE WILL CONTINUE TO WORK RATHER BRISKLY OFF TO THE NORTHEAST AND WHILE A ROGUE SMALL HAIL/WIND GUST IS POSSIBLE...THINK THESE HAVE WEAKENED IN A GENERAL SENSE FOR THE EVENING. ATTENTION THEN TURNS TO THE STRONGER SYNOPTIC FORCING ENTERING CNTL/ERN IL CURRENTLY WITH AN ATTENDANT COLD FRONT. RECENT HRRR RUNS SIMPLY ADAMANT A WHOLE BUNCH OF SHOWERS/STORMS WILL DEVELOP ACROSS EASTERN IND/WRN OHIO IN A FEW HOURS...AND DON/T WANT TO TOTALLY DISCOUNT THIS AS IT HAS BEEN ONE OF THE FEW STEADIER SIGNALS IN THE HRRR THE LAST FEW HOURS. BUT LAST GLIMPSES OF SATELLITE VIS PICS OVER IND SHOW THAT THE STABLE AIRMASS IS INTACT AND VERY FEW AGITATED CUMULUS/ACCAS ARE EVIDENT. THERE SHOULD BE A MODEST RAMP-UP OF THE LOW LEVEL JET IMMEDIATELY DOWNSTREAM OF THE PV ANOMALY ROTATING THROUGH IL RIGHT NOW SO THE SYNOPTIC SIGNALS SAY TO STAY THE COURSE WITH HIGHER RAIN/STORM CHANCES BEGINNING VERY LATE THIS EVENING. EARLY LOOK AT THE 02.00Z KILN BALLOON DATA SUGGESTS INSTBY IS NOT IMPRESSIVE BUT WINDS/SHEAR CONTINUE TO BE FAVORABLE FOR STORM ORGANIZATION. HOWEVER...SPC MESOA DATA SUGGESTING THE DCAPE POOL HAS BEEN MODIFIED SOME AND NOW THE NEAR SFC SHALLOW INVERSION HAS BEGUN TO FORM PER OBS. SO WHILE A FEW SEVERE REPORTS ARE POSSIBLE OVERNIGHT...JUST NOT SEEING A GREAT SETUP AND THUS WILL TONE BACK HAZ WX OUTLOOK FOR THE OVERNIGHT PERIOD. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... SECONDARY WAVE ALOFT FINALLY ESCORTS THE TROUGH AXIS OUT OF THE AREA TOMORROW AND THIS ALLOWS A WEAK SECONDARY FRONT TO DEVELOP AND PUSH THROUGH DURING THE DAY. MAY BE A BROKEN BAND OF SHOWERS ALONG THIS FEATURE BY MID AFTERNOON...SO CARRIED THIS CHANCE FROM NW-SE ACROSS THE AREA DURING THE LATE MORNING INTO THE EARLY EVENING. MUCH COOLER/DRIER AIRMASS ARRIVES ON THE HEELS OF THIS FRONT AND MAKES FOR A COMFORTABLE SUNDAY NIGHT WITH LOWS DOWN INTO THE 50S UNDER CLEARING SKIES. && .LONG TERM /MONDAY THROUGH SATURDAY/... PERIOD BEGINS WITH HIGH PRESSURE CENTERED OVER THE UPPER MS VALLEY. THE HIGH WILL BUILD SE INTO THE LOWER GREAT LAKES THROUGH TUESDAY. HIGHS ON MONDAY WILL BE COOL...RANGING FROM THE UPPER 60S TO THE LOWER 70S WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR EARLY JUNE. TEMPERATURES WILL FALL INTO THE UPPER 40S TO LOWER 50S MONDAY NIGHT. 12Z MODELS HAVE COME IN A LITTLE WARMER FOR TUESDAY. SO TOOK A CONSENSUS FORECAST AND RAISED HIGHS FOR TUESDAY INTO THE LOWER TO MID 70S. ON WEDNESDAY THE SFC HIGH PRESSURE IS FORECAST TO SLIDE EAST. THE ECMWF IS THE QUICKEST WITH THE RETURN PCPN...BUT THE REMAINING MODELS KEEP THE FA DRY...SO LEANED TOWARDS THE MAJORITY. WEDNESDAY NIGHT INTO THURSDAY AS WRMFNT DEVELOPS OVER THE OH VLY... ATMOSPHERE BECOMES UNTIL STABLE AND IT LOOKS LIKE THERE WILL BE A CHANCE OF SCT TSRA. THU NGT INTO FRI...H5 WAVE SWINGS UP THE OH VLY ADDING EXTRA LIFT AND IT DRIVES A CDFNT ACROSS THE REGION KEEPING CHC OF CONVECTION IN THE FORECAST. DRIER AIR TRIES TO BUILD IN FOR SATURDAY. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... SOUTHWEST WINDS WILL CONTINUE TO GUST AROUND 20-25 KTS THIS AFTERNOON. STILL A STUBBORN MID TO HIGH CLOUD DECK OVER MOST OF THE AREA ALTHOUGH SCT LIGHT SHOWERS ARE COMING TO AN END. WATCHING FOR POSSIBLE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON. IF THIS MATERIALIZES...AND CONFIDENCE IS NOT PARTICULARLY HIGH BASED ON LATEST HIGH RESOLUTION MODEL SOLUTIONS...THINKING THE BEST CHANCE WOULD BE AROUND THE EASTERN TAF SITES AS THAT AREA HAS SEEN THE MOST DAYTIME HEATING SO FAR. BETTER CHANCE FOR SHOWERS AND STORMS FOR ALL TAF SITES WILL COME LATE THIS AFTERNOON AND EVENING AS A COLD FRONT APPROACHES FROM THE WEST. THIS ACTIVITY WILL SPREAD FROM WEST TO EAST WITH THE POSSIBILITY OF A FEW STRONG TO SEVERE STORMS CONTAINING BRIEF YET STRONG SHIFTING WINDS AS THEY PASS. MVFR/IFR CIGS AND VSBYS WILL BE POSSIBLE WITH ANY STORMS LATE THIS AFTERNOON AND EVENING. CIGS WILL LIKELY REMAIN MVFR LATE TONIGHT AND SOME LINGERING SHOWERS WILL BE POSSIBLE AS THE COLD FRONT MOVES ACROSS THE AREA. EXPECT A GRADUAL RETURN TO VFR CIGS SUNDAY MORNING. OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU SHORT TERM...BINAU LONG TERM...SITES AVIATION...KURZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
723 PM EDT SAT JUN 1 2013 .SYNOPSIS... WARM SECTOR THROUGH TONIGHT WITH CONVECTION POSSIBLE ESPECIALLY LATE THIS AFTERNOON AND EVENING. COLD FRONT CROSSES SUNDAY INTO MONDAY. COOLER AND DRIER TO START NEXT WEEK. WARM FRONT THURSDAY. && .NEAR TERM /THROUGH SUNDAY/... PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND SHOWERS/THUNDERSTORM CHANCES AS WELL AS POTENTIAL FOR SEVERE WEATHER. REGARDING THUNDERSTORMS THIS AFTERNOON/EVENING...15Z REGIONAL RADAR IMAGERY AND SFC OBS CONTINUE TO SHOW ONGOING WIDESPREAD PRECIP...MAINLY IN THE FORM OF SHOWERS...FROM WESTERN OHIO SW-WARD DOWN THE EXTENT OF THE OHIO RIVER INTO WESTERN TENN/ARKANSAS RESULTANT OF STRONG OVERNIGHT CONVECTION. SFC TEMPS IN WHAT APPEARED YESTERDAY TO BE THE FAVORED AREAS OF THUNDERSTORMS AND SUBSEQUENT SVR WX INITIATION STILL ONLY IN THE MID/UPPER 60S GENERALLY...WITH NO LIGHTNING STRIKES CURRENTLY. SHOULD PRECIP/CLOUDS HANG ON OVER THAT AREA...STRONGER STORMS MAY WAIT TO FORM FURTHER EAST OVER CENTRAL OHIO AND POINTS SOUTHWEST WHERE SFC TEMPS HAVE WARMED TO THE UPPER 70S/LOW 80S DESPITE FAIRLY DENSE HIGH CLOUD COVER. GOOD DYNAMICS ARRIVE BY 21Z WHICH CONTINUE INTO THE EVENING...PARTICULARLY OVER THE WESTERN ZONES WHERE 30-40KTS OF SHEAR IN PLACE. WITH THE FRONT STILL WELL TO THE WEST HOWEVER...TOUGH CALL ON DETERMINING A TRIGGERING MECHANISM. A VORT MAX PER LATEST RUC13 PROGGED TO PUSH NE-WARD THROUGH CENTRAL KY BY 21Z-00Z MAY BE ENOUGH TO GET THINGS GOING. DO FEEL THAT THUNDERSTORMS WILL SLOWLY BEGIN TO FORM BY THE MID/LATE AFTERNOON HOURS AT FIRST RELATIVELY UNORGANIZED...WITH A GRADUAL INCREASE FROM THE WEST BY AND AFTER 00Z SUN. AS USUAL...IT APPEARS TO BE A RACE BETWEEN STORM DEVELOPMENT AND LOSS OF DAYTIME PEAK INSTABILITY. BUT IN THE END...SOME STORMS MAY BECOME STRONG TO SEVERE MAINLY ACROSS THE FAR WESTERN ZONES CLOSER TO THE OHIO RIVER BUT THE THREAT APPEARS MARGINAL AT BEST. STRONG WINDS APPEAR TO BE THE MAIN HAZARD WITH DCAPE VALS OVER 1K J/KG JUST TO THE SOUTHWEST OF THE FORECAST AREA BUT EL/S ARE SUFFICIENTLY TALL FOR SOME LARGE HAIL. LITTLE CHANGE FROM PREV FORECAST WITH REGARD TO THE REMAINDER OF THE OVERNIGHT HOURS. A MORE GENERAL CONVECTIVE RAINFALL WITH SOME THUNDER PERHAPS WILL PUSH INTO THE AREA WITH GOOD DEEP LAYER MOISTURE AND A PREFRONTAL TROUGH-TYPE FEATURE. STILL EXPECTING ROUGHLY A HALF-INCH OR SO ACROSS THE AREA...AND SOME LOCALIZED WATER ISSUES COULD BE POSSIBLE SHOULD HEAVY SHOWERS/STORMS PASS OVER THE SAME LOCATION BUT NOTHING WIDESPREAD EXPECTED. SUNDAY...AGAIN LITTLE CHANGE FROM PREV FCST WITH THE MAIN AXIS OF DEEP MOISTURE PUSHING ACROSS DURING THE MORNING HOURS WITH HIGH CHANCE POPS CONFINED MAINLY TO CKB-CRW AND POINTS EAST BY 18Z. ACTUAL COLD FRONT HOWEVER STILL LAGS WELL BEHIND AND ONLY ENTERING THE NW ZONES BY END OF THE PERIOD. INHERITED MAX TEMPS AROUND 80 FOR LOWLANDS STILL LOOK ON TRACK. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... GFS/ECMWF SHOW COLD FRONT OVER THE OH RIVER BY 00Z MONDAY. SHOWERS AND STORMS WILL BE POSSIBLE ALONG THE FRONT...DIMINISHING IN INTENSITY AND COVERAGE BY EARLY MONDAY MORNING. THE FRONT BRINGS A WIND SHIFT FROM THE NORTHWEST ALOFT MONDAY NIGHT...WHILE AT THE SFC COULD BECOME LIGHT AND VARIABLE...OR CALM. THEN...FLOW BECOMES NORTHERLY LATER MONDAY AND MONDAY NIGHT TO BRING COOLER TEMPERATURES...MILD AFTERNOON...AND RELATIVELY COLDER NIGHTS ARE EXPECTED THROUGH TUESDAY NIGHT. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... WEAK SEMI ZONAL FLOW ALOFT AND NO VORT MAX FROM SHORTWAVES SUGGEST BROAD HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH EARLY THURSDAY. THIS WILL CONTINUE TO CLEARING CONDITIONS...EXCEPT FOR LOW LEVEL DIURNAL CU DURING THE AFTERNOON HOURS. NEAR NORMAL TEMPERATURES EXPECTED THURSDAY ON. TWEAKED DOWN WPC TEMPERATURE A BIT. A WARM FRONTAL BOUNDARY FORMS ACROSS OH INTO SOUTHEAST OH THURSDAY...UNDER SOUTHERLY FLOW. THE SOUTHERLY WINDS WILL ALSO RESULT IN INCREASING LOW-LEVEL MOISTURE AND THE CHANCES FOR SHOWERS AND STORMS...MAINLY DIURNAL IN NATURE...WILL ALSO RETURN THROUGH THE REMAINDER OF THE PERIOD. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... 00Z SUNDAY THRU 00Z MONDAY... BAND OF CONVECTION WELL AHEAD OF A COLD FRONT WILL SLOWLY MOVE EASTWARD AND REACH THE OHIO RIVER BY 06Z SUNDAY...THE I79 CORRIDOR BY 09Z...AND THE MOUNTAINS BY 12Z. OUTSIDE OF THIS RAIN...EXPECT VFR CONDITIONS WILL PREVAIL. GENERALLY MVFR CONDITIONS IN THIS RAIN...WITH AN EMBEDDED THUNDERSTORM POSSIBLE. WILL USE VCTS IN TAFS. THE SHOWERS AND THUNDERSTORMS SHOULD DECREASE FROM THE WEST AFTER 12Z...WITH ONLY A FEW STORMS EXPECTED ACROSS THE LOWLANDS AFTER 19Z. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: TIMING OF BAND OF CONVECTION LATER PART OF PERIOD MAY VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE SUN 06/02/13 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY H H H H H H H H H H H M HTS CONSISTENCY H H H H H H H H M M M M BKW CONSISTENCY H H H H H H H H H H H M EKN CONSISTENCY H H H H H H H H H H H M PKB CONSISTENCY H H H H H H H H H M M M CKB CONSISTENCY H H H H H H H H H H H M AFTER 00Z MONDAY... IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS SUNDAY NIGHT...AND IN POST-RAIN FOG SUNDAY NIGHT INTO MONDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...50 SHORT TERM...ARJ LONG TERM...ARJ AVIATION...JSH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
256 PM EDT FRI MAY 31 2013 .SYNOPSIS... WARM SECTOR THROUGH SATURDAY NIGHT WITH CONVECTION POSSIBLE ESPECIALLY DURING DAYTIME HEATING HOURS. COLD FRONT CROSSES SUNDAY. COOLER AND DRIER TO START NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... 18Z RADAR IMAGERY SHOWING SHOWERS AND THUNDERSTORMS CONTINUING TO DEVELOP TO THE WEST ROUGHLY AROUND THE IN/OH BORDER AREA SOUTHWARD INTO CENTRAL KENTUCKY. OUT AHEAD OF THAT GENERAL AREA A FEW DISCRETE THUNDERSTORMS HAD FORMED TO THE EAST. PRIMARY CONCERNS IN THE NEAR TERM REVOLVE AROUND THIS EVENING/S CONVECTION AS WELL AS REDEVELOPING SHOWERS/THUNDERSTORMS TOMORROW. THIS EVENING...TOUGH CALL ON EXACTLY HOW FAR EAST TO TAKE PRECIP WITH A READILY-APPARENT DECAYING MCV PUSHING E/NE-WARD ACROSS NORTH CENTRAL KY. LATEST RAP SEEMS TO HAVE SOMEWHAT OF A HANDLE ON THE SHEAR ASSOC WITH IT...WITH NEAR 40KTS OF SHEAR DEPICTED ACROSS THE SW OHIO AND NC KY AREAS. FURTHER EAST OVER OUR WESTERN ZONES...SHEAR IS APPRECIABLY LOWER AND ONLY AROUND 15-20KTS. LATEST RAP RUNS ALSO CONTINUE TO WEAKEN/SHEAR THE VORT MAX ASSOC WITH THE MCV...WITH SHEAR VALUES ONLY CLIMBING TO AROUND 25KTS NEAR PERRY CO OH...AND LESS POINTS EAST AND SOUTH OF THAT...BY 00Z. INSTABILITY WILL BE DECREASING AS WELL AND BECOMING MORE ELEVATED AS USUAL...WHICH SHOULD SPELL A DECREASING RISK OF STRONG WINDS. ALL IN ALL...DO BELIEVE SHOWERS AND SOME THUNDERSTORMS STAND A DECENT CHANCE OF REACHING OUR WESTERN ZONES AND PARTICULARLY THE SE OHIO ZONES. WHILE A SEVERE THUNDERSTORM CAN/T BE COMPLETELY RULED OUT IN THOSE LOCATIONS...CURRENT THINKING IS THAT THE BULK OF ANY SEVERE WX REMAINS WEST. OVERNIGHT...WILL KEEP GENERAL INHERITED FORECAST AND DRY OUT MOST LOCATIONS BTWN 03Z-06Z. DID ELECT TO KEEP A SLIGHT CHANCE ACROSS THE FAR NW ZONES HOWEVER...ON THE NOSE OF A 850MB JET. PREV FCST LOW TEMPS IN THE MID/UPPER 60S LOWLANDS STILL LOOK GOOD. SLIGHTLY STRONGER BL WINDS OVERNIGHT PROGGED AFTER 06Z SHOULD PRECLUDE WIDESPREAD FOG FORMATION BUT THE USUAL SPOTS SUCH AS EKN WILL MOST LIKELY SEE REDUCED VIS NEAR DAWN. TOMORROW...INHERITED MAX TEMPS IN THE MID/UPPER 80S LOWLANDS LOOK GOOD. PRIMARY FOCUS ON THUNDERSTORMS AND SVR THUNDERSTORM POTENTIAL. NOT REALLY SEEING MUCH IN THE WAY OF ANY ORGANIZED LARGE-SCALE LIFT FOR MUCH OF THE DAY WITH THE TROUGH AXIS AND SFC COLD FRONT STILL WELL TO THE WEST. LOWERED POPS TO LOW CHANCE FOR THE MORNING HOURS AND INTO THE EARLY AFTERNOON HOURS AS SUCH. BTWN 18Z-21Z...GOOD DYNAMICS ARRIVE TO THE WEST OF OUR AREA...OVER IN/WEST OH SOUTHWARD INTO CENTRAL KY. THIS AREA SHOULD SERVE FOR ORGANIZED CONVECTIVE INITIATION BY 21Z...WITH SUPERCELLS A POSSIBILITY. THIS AREA WILL SLOWLY PROGRESS EASTWARD...BUT RIGHT-MOVER MOTION WOULD TAKE THESE STORMS IN AN MORE E/NE DIRECTION AROUND 30KTS. AGAIN AS WITH THIS AFTERNOON...THE BULK OF SVR WX SHOULD REMAIN WEST BUT WITH BETTER SHEAR OVER OUR AREA TOMORROW A BETTER LIKELIHOOD OF SVR WX OVER OUR WESTERN ZONES EXISTS PRIMARILY LATE AFTERNOON INTO MID-EVE HOURS. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/... COLD FRONT WILL PUSH EAST INTO THE CWA SUNDAY MORNING. TIMING OF THE FRONT LOOKS TO BE A FEW HOURS SLOWER THAN PREVIOUS RUNS...BUT STILL THINKING MUCH OF THE CWA WILL NOT SEE MUCH IN TERMS OF SEVERE DUE TO TIMING...ALTHOUGH THE EASTERN ZONES WILL BE MORE SUSCEPTIBLE DUE TO LATER FRONTAL PASSAGE. DECENT CAPE...GENERALLY 1500-2000 J/KG...ALONG WITH 30-40 KTS 0-6KM BULK SHEAR WILL CREATE A POTENTIAL FOR STRONG STORMS...WITH WINDS...AND HAIL THE PRIMARY THREATS...MAINLY ACROSS THE EAST. HOWEVER...PLENTY OF CLOUD COVER OUT AHEAD OF THE FRONT MAY ALSO HELP TO MITIGATE THE SEVERE THREAT...ESPECIALLY EARLY ON. SO FOR NOW...ITS A WAIT AND SEE SCENARIO TO SEE IF ANY OF THE ABOVE MENTIONED FACTORS ARE ABLE TO LINE UP...BUT LOOKING LIKE BULK OF SEVERE THREAT WILL BE TO THE EAST OF THE CWA. AS OF RIGHT NOW...SPC HAS THE SLIGHT RISK TO THE EAST OF THE CWA...WITH CWA IN GENERAL THUNDER...AND A 5 PERCENT PROB OUTLOOK FOR SEVERE. COLD FRONT WILL EXIT TO THE EAST OF THE CWA SUNDAY NIGHT...WITH COOLER AND DRIER WEATHER TAKING HOLD. && .LONG TERM /TUESDAY THROUGH FRIDAY/... GENERALLY FOLLOWED WPC THINKING WITH SOME TWEAKS. HIGH PRESSURE WILL DOMINATE THE REGION ON TUESDAY...WITH TEMPERATURES NEAR NORMAL READINGS. HOWEVER...THE HIGH WILL PUSH EAST ON WEDNESDAY...RESULTING IN SOUTHERLY WINDS AND WARMER TEMPERATURES. THE SOUTHERLY WINDS WILL ALSO RESULT IN INCREASING LOW-LEVEL MOISTURE AND THE CHANCES FOR SHOWERS AND STORMS...MAINLY DIURNAL IN NATURE...WILL ALSO RETURN THROUGH THE REMAINDER OF THE PERIOD. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... 12Z FRIDAY THRU 12Z SATURDAY... VFR FOR MOST SITES THROUGH MUCH OF THE PERIOD. PUT IN SOME RIVER AND VALLEY FOG THAT WILL RESULT IN SOME MVFR CONDITIONS FOR THE VALLEYS OVERNIGHT. EKN IS EXPECTED TO DROP TO IFR FOR AT LEAST A FEW HOURS WITH CALM WINDS AND HIGHER RH IN THE SHELTERED VALLEY. TOWARD THE END OF THE PERIOD...CIGS ARE EXPECTED TO LOWER AS PRECIP BEGINS TO MOVE INTO SE OH AND NORTHERN WV...HOWEVER...GENERALLY EXPECT VFR CONDITIONS TO REMAIN. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY... FORECAST CONFIDENCE...HIGH. ALTERNATE SCENARIOS: SUB-VFR VIS OVERNIGHT MAY VARY IN EXPECTED COVERAGE AND/OR INTENSITY. TIMING AND COVERAGE OF SHOWERS AND THUNDERSTORMS MAY VARY. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H M M PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z SATURDAY... IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS SUNDAY INTO SUNDAY NIGHT...AND POST RAIN...FOG...AND LOW CLOUDS LATE SUNDAY NIGHT INTO MONDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JSH/50/SL NEAR TERM...50 SHORT TERM...SL LONG TERM...JSH AVIATION...LS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1112 PM EDT SAT JUN 1 2013 .SYNOPSIS... A STRONG RIDGE AND RELATIVELY WARM MOIST AIR OVER OUR REGION WILL BE DISPLACED BY A FRONTAL SYSTEM SUNDAY. BEHIND THE FRONT AND OVER THE COMING WEEK A TROUGH WILL DOMINATE OUR REGION WITH GENERALLY COOLER AND DRIER AIR PREVAILING. OUR BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE AHEAD OF THE FRONTAL SYSTEM SUNDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... FOR THE OVERNIGHT...LOOKING UPSTREAM...LAKE BREEZE INTERACTION WITH GREATER MOISTURE AND INSTABILITY CONTS TO YIELED SCATTERED STORMS FROM EASTERN OHIO TO THE IMMEDIATE LAKE ERIE AND LAKE ONTARIO SHORELINES. PREVAILING SOUTHERLY COMPONENT HAS BEEN STRONG ENOUGH TO PREVENT ANY EASTWARD DRIFT OF THE THE BOUNDARY THUS FAR...SPARING MY NORTHWEST COUNTIES. LATEST RAP INDICATES THAT WILL CONTINUE TO BE THE CASE FOR THE REST OF THE EVENING...WITH POPS RAMPING UP AFTER MIDNIGHT AND INCREASING FROM WEST TO EAST THEREAFTER. THIS ACTIVITY COMES ALONG THE LEADING EDGE OF A STRENGTHENING 40-50KT 850 MB JET AND ANOMALOUS BUT FAIRLY NARROW PLUME OF DEEPER LAYER MOISTURE (~1.65" PW) TRACKING TO THE ALLEGHENY FRONT BY 12Z SUN. SO... WILL KEEP POPS UP ALONG MY WESTERN AND NORTHWESTERN BORDERS OVERNIGHT. AS PREVIOUSLY MENTIONED...POTENTIAL FOR SOME HEAVIER DOWNPOURS AS PWATS REMAIN ABOVE NORMAL. TEMPS REMAIN MILD OVERNIGHT IN SW FLOW...WITH HUMID LOWS ONLY FALLING INTO THE 60S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... AN APPROACHING COLD FRONT WILL BRING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ON SUNDAY...EARLIER IN THE WEST AND FROM MIDDAY ON IN THE EAST. WE COULD BE DEALING WITH SOME SEVERE STORMS...ESPECIALLY OVER EASTERN AREAS WHERE OPERATIONAL MODELS ARE SURPRISINGLY AGGRESSIVE IN DEVELOPING THE INSTABILITY. IF ENOUGH SUN CAN BREAK THROUGH...WINDS ALOFT ARE PRETTY IMPRESSIVE AND STRONG WIND GUSTS COULD MATERIALIZE. HIGH TEMPS FOR SUNDAY ARE EXPECTED TO BE IN THE LOWER TO MID 80S OVERALL BUT THE RAIN-COOLED WILL SEE HIGHS REACHING THE MID TO UPPER 70S. IT SHOULD BE THE LAST WIDESPREAD VERY WARM AND HUMID DAY FOR A WHILE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... HIGH PROBABILITY FORECASTS FROM ENSEMBLES IMPLIES THE FRONT IS THROUGH PA IN THE 00 TO 1200 UTC TIME-FRAME MONDAY. BY ABOUT 0600 UTC MONDAY THE PRECIPITABLE WATER (PW) VALUES SHOULD BE AT OR SLIGHTLY BELOW NORMAL. THIS IMPLIES MOST OF THE RESIDUAL SHOWER ACTIVITY FROM SUNDAY SHOULD PUSH TO THE EAST A FEW HOURS EITHER SIDE OF MIDNIGHT. BY MONDAY EVENING THE PW FALLS TO -1SIGMA BELOW NORMAL IMPLYING COOL DRY CONDITIONS MONDAY NIGHT AND TUESDAY. PW SHOULD RETURN TOWARD NORMAL SOMETIME WEDNESDAY IMPLYING A GOOD 2-3 DAYS OF DRY WEATHER BEHIND THE FRONT. THE COLD AIR AND LOW-LEVEL ANTICYCLONE LAG THE DRY AIR IMPLYING TUESDAY MORNING COULD BE THE COLDEST MORNING WHEN 850 HPA TEMPS WILL BE BELOW NORMAL. THE HIGH PRESSURE BUILDS IN TUES-WED SO SHOULD BE CHILLY OVERNIGHT WEDNESDAY TOO. AS THE ANTICYCLONE SORT OF HANGS UP TO OUR NORTHEAST WE SHOULD GET A STABLE SITUATION WITH EASTERLY FLOW...SETTING UP A NICE BOUNDARY..THEN THE FIRST SURGE OF MOISTURE COMES OVER WESTERN PA POTENTIALLY OVERNIGHT WEDNESDAY OR THURSDAY IMPLYING INCREASE IN SHOWERS BY THURSDAY IN THE WEST...STILL LIGHT AND NOT A SIGNIFICANT THREAT. WITH THE HIGH TO THE EAST COULD BE A CLOUDY PERIOD OVER WEST/CENTRAL AREAS AS WE HAVE AN IMPLIED BOUNDARY TO FOCUS CLOUDS AND OVERRUNNING SHOWERS. BETWEEN THE MOISTURE OVER THE SW ATLANTIC AND THE IMPLIED BOUNDARY PUSHING INTO PA FROM THE WEST...MOISTURE AND SHOWER POTENTIAL SHOULD INCREASE THURSDAY INTO FRIDAY. IF THE BOUNDARY CAN PUSH THROUGH FRIDAY OR EARLY SATURDAY WE HAVE THE POTENTIAL FOR A GOOD WEEKEND. GEFS/CMCE IMPLY THAT A LOW-LEVEL JET AND MOISTURE PLUME PUSH THROUGH FRIDAY AHEAD OF THIS FRONTAL BOUNDARY. SO...DRYING OUT FAST MONDAY AROUND MIDNIGHT...DRY PERIOD MONDAY THROUGH WED AND TEMPS NEAR OR SLIGHTLY BELOW NORMAL...THEN INCREASING CHANCE SHOWERS. BEST CHANCE RAIN AT THIS TIME WOULD BE IN THE LATE THURSDAY EARLY SATURDAY TIME-FRAME. WHICH WILL CHANGE. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... A CORRIDOR OF GREATER MOISTURE AND WINDS ALOFT WILL PUSH INTO NW PA LATE TONIGHT...RESULTING IN AN INCREASING CHC OF LATE NIGHT SHRA/TSRA AT BFD. ELSEWHERE...EXPECT GENERALLY GOOD FLYING CONDS OVERNIGHT WITH WIDESPREAD VFR CONDS AND LGT WINDS. AS HAS OCCURRED THE LAST COUPLE MORNINGS...A BIT OF FOG IS POSSIBLE ARND DAWN AT LNS. THE AFOREMENTIONED CORRIDOR OF MOISTURE AND WINDS ALOFT WILL BRING SHOWERS AND THE POTENTIAL OF MVFR CIGS TO THE CENTRAL MTNS DURING THE LATE MORNING HOURS. BY AFTERNOON...DIURNAL HEATING/STEEPENING LAPSE RTS SHOULD CAUSE ANY CIGS TO RISE ABV 3 KFT. HOWEVER...THE THREAT TO AVIATION WILL SHIFT TOWARD THE POTENTIAL OF LOCALLY STRONG THUNDERSTORMS...ESP OVR THE EASTERN HALF OF THE STATE. A SLOW-MOVING COLD FRONT WILL SAG SE ACROSS THE REGION SUNDAY EVENING...BRINGING DRIER AIR AND ENDING THE THREAT OF TSRA FROM NW TO SE. OUTLOOK... MON...LOW CIGS/FOG POSS EARLY OVR W MTNS. TUE-WED...NO SIG WX EXPECTED. THU...ISOLD PM THUNDERSTORM IMPACTS POSS W MTNS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/RXR NEAR TERM...DEVOIR/RXR SHORT TERM...RXR LONG TERM...GRUMM AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1035 PM EDT SAT JUN 1 2013 .SYNOPSIS... A STRONG RIDGE AND RELATIVELY WARM MOIST AIR OVER OUR REGION WILL BE DISPLACED BY A FRONTAL SYSTEM SUNDAY. BEHIND THE FRONT AND OVER THE COMING WEEK A TROUGH WILL DOMINATE OUR REGION WITH GENERALLY COOLER AND DRIER AIR PREVAILING. OUR BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE AHEAD OF THE FRONTAL SYSTEM SUNDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... FOR THE OVERNIGHT...LOOKING UPSTREAM...LAKE BREEZE INTERACTION WITH GREATER MOISTURE AND INSTABILITY CONTS TO YIELED SCATTERED STORMS FROM EASTERN OHIO TO THE IMMEDIATE LAKE ERIE AND LAKE ONTARIO SHORELINES. PREVAILING SOUTHERLY COMPONENT HAS BEEN STRONG ENOUGH TO PREVENT ANY EASTWARD DRIFT OF THE THE BOUNDARY THUS FAR...SPARING MY NORTHWEST COUNTIES. LATEST RAP INDICATES THAT WILL CONTINUE TO BE THE CASE FOR THE REST OF THE EVENING...WITH POPS RAMPING UP AFTER MIDNIGHT AND INCREASING FROM WEST TO EAST THEREAFTER. THIS ACTIVITY COMES ALONG THE LEADING EDGE OF A STRENGTHENING 40-50KT 850 MB JET AND ANOMALOUS BUT FAIRLY NARROW PLUME OF DEEPER LAYER MOISTURE (~1.65" PW) TRACKING TO THE ALLEGHENY FRONT BY 12Z SUN. SO... WILL KEEP POPS UP ALONG MY WESTERN AND NORTHWESTERN BORDERS OVERNIGHT. AS PREVIOUSLY MENTIONED...POTENTIAL FOR SOME HEAVIER DOWNPOURS AS PWATS REMAIN ABOVE NORMAL. TEMPS REMAIN MILD OVERNIGHT IN SW FLOW...WITH HUMID LOWS ONLY FALLING INTO THE 60S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... AN APPROACHING COLD FRONT WILL BRING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ON SUNDAY...EARLIER IN THE WEST AND FROM MIDDAY ON IN THE EAST. WE COULD BE DEALING WITH SOME SEVERE STORMS...ESPECIALLY OVER EASTERN AREAS WHERE OPERATIONAL MODELS ARE SURPRISINGLY AGGRESSIVE IN DEVELOPING THE INSTABILITY. IF ENOUGH SUN CAN BREAK THROUGH...WINDS ALOFT ARE PRETTY IMPRESSIVE AND STRONG WIND GUSTS COULD MATERIALIZE. HIGH TEMPS FOR SUNDAY ARE EXPECTED TO BE IN THE LOWER TO MID 80S OVERALL BUT THE RAIN-COOLED WILL SEE HIGHS REACHING THE MID TO UPPER 70S. IT SHOULD BE THE LAST WIDESPREAD VERY WARM AND HUMID DAY FOR A WHILE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... HIGH PROBABILITY FORECASTS FROM ENSEMBLES IMPLIES THE FRONT IS THROUGH PA IN THE 00 TO 1200 UTC TIME-FRAME MONDAY. BY ABOUT 0600 UTC MONDAY THE PRECIPITABLE WATER (PW) VALUES SHOULD BE AT OR SLIGHTLY BELOW NORMAL. THIS IMPLIES MOST OF THE RESIDUAL SHOWER ACTIVITY FROM SUNDAY SHOULD PUSH TO THE EAST A FEW HOURS EITHER SIDE OF MIDNIGHT. BY MONDAY EVENING THE PW FALLS TO -1SIGMA BELOW NORMAL IMPLYING COOL DRY CONDITIONS MONDAY NIGHT AND TUESDAY. PW SHOULD RETURN TOWARD NORMAL SOMETIME WEDNESDAY IMPLYING A GOOD 2-3 DAYS OF DRY WEATHER BEHIND THE FRONT. THE COLD AIR AND LOW-LEVEL ANTICYCLONE LAG THE DRY AIR IMPLYING TUESDAY MORNING COULD BE THE COLDEST MORNING WHEN 850 HPA TEMPS WILL BE BELOW NORMAL. THE HIGH PRESSURE BUILDS IN TUES-WED SO SHOULD BE CHILLY OVERNIGHT WEDNESDAY TOO. AS THE ANTICYCLONE SORT OF HANGS UP TO OUR NORTHEAST WE SHOULD GET A STABLE SITUATION WITH EASTERLY FLOW...SETTING UP A NICE BOUNDARY..THEN THE FIRST SURGE OF MOISTURE COMES OVER WESTERN PA POTENTIALLY OVERNIGHT WEDNESDAY OR THURSDAY IMPLYING INCREASE IN SHOWERS BY THURSDAY IN THE WEST...STILL LIGHT AND NOT A SIGNIFICANT THREAT. WITH THE HIGH TO THE EAST COULD BE A CLOUDY PERIOD OVER WEST/CENTRAL AREAS AS WE HAVE AN IMPLIED BOUNDARY TO FOCUS CLOUDS AND OVERRUNNING SHOWERS. BETWEEN THE MOISTURE OVER THE SW ATLANTIC AND THE IMPLIED BOUNDARY PUSHING INTO PA FROM THE WEST...MOISTURE AND SHOWER POTENTIAL SHOULD INCREASE THURSDAY INTO FRIDAY. IF THE BOUNDARY CAN PUSH THROUGH FRIDAY OR EARLY SATURDAY WE HAVE THE POTENTIAL FOR A GOOD WEEKEND. GEFS/CMCE IMPLY THAT A LOW-LEVEL JET AND MOISTURE PLUME PUSH THROUGH FRIDAY AHEAD OF THIS FRONTAL BOUNDARY. SO...DRYING OUT FAST MONDAY AROUND MIDNIGHT...DRY PERIOD MONDAY THROUGH WED AND TEMPS NEAR OR SLIGHTLY BELOW NORMAL...THEN INCREASING CHANCE SHOWERS. BEST CHANCE RAIN AT THIS TIME WOULD BE IN THE LATE THURSDAY EARLY SATURDAY TIME-FRAME. WHICH WILL CHANGE. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... EARLY EVENING VISIBLE SATL IMAGERY SHOWING SOME VERTICAL DEVELOPMENT TO LINE OF CU ALONG THE SPINE OF THE APPALACHIANS FROM AOO TO UNV AND IPT. CAN/T RULE OUT AN ISOLD SHRA/TSRA AT THESE AIRFIELDS EARLY THIS EVENING. HOWEVER...CHANCE TOO SMALL TO WARRANT MENTION IN TAFS ATTM. A CORRIDOR OF GREATER MOISTURE AND WINDS ALOFT WILL PUSH INTO NW PA LATE TONIGHT...RESULTING IN A GREATER CHC OF LATE NIGHT SHRA/TSRA AT BFD. ELSEWHERE...EXPECT GENERALLY GOOD FLYING CONDS OVERNIGHT WITH WIDESPREAD VFR CONDS AND LGT WINDS. AS HAS OCCURRED THE LAST COUPLE MORNINGS...A BIT OF FOG IS POSSIBLE ARND DAWN AT LNS. THE AFOREMENTIONED CORRIDOR OF MOISTURE AND WINDS ALOFT WILL BRING SHOWERS AND THE POTENTIAL OF MVFR CIGS TO THE CENTRAL MTNS DURING THE LATE MORNING HOURS. BY AFTERNOON...DIURNAL HEATING/STEEPENING LAPSE RTS SHOULD CAUSE ANY CIGS TO RISE ABV 3 KFT. HOWEVER...THE THREAT TO AVIATION WILL SHIFT TOWARD THE POTENTIAL OF LOCALLY STRONG THUNDERSTORMS...ESP OVR THE EASTERN HALF OF THE STATE. A SLOW-MOVING COLD FRONT WILL SAG SE ACROSS THE REGION SUNDAY EVENING...BRINGING DRIER AIR AND ENDING THE THREAT OF TSRA FROM NW TO SE. OUTLOOK... MON...LOW CIGS/FOG POSS EARLY OVR W MTNS. TUE-WED...NO SIG WX EXPECTED. THU...ISOLD PM THUNDERSTORM IMPACTS POSS W MTNS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/RXR NEAR TERM...DEVOIR/RXR SHORT TERM...RXR LONG TERM...GRUMM AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
906 PM EDT SAT JUN 1 2013 .SYNOPSIS... A STRONG RIDGE AND RELATIVELY WARM MOIST AIR OVER OUR REGION WILL BE DISPLACED BY A FRONTAL SYSTEM SUNDAY. BEHIND THE FRONT AND OVER THE COMING WEEK A TROUGH WILL DOMINATE OUR REGION WITH GENERALLY COOLER AND DRIER AIR PREVAILING. OUR BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE AHEAD OF THE FRONTAL SYSTEM SUNDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 600 MB WARM CAP AND DRY AIR ENTRAINMENT ALOFT HELPED TO DISSIPATE DIURNALLY DRIVEN ISOLATED SHOWERS. FOR THE OVERNIGHT...LOOKING UPSTREAM...LAKE BREEZE INTERACTION WITH GREATER MOISTURE AND INSTABILITY CONTS TO YIELED SCATTERED STORMS FROM EASTERN OHIO TO THE IMMEDIATE LAKE ERIE AND LAKE ONTARIO SHORELINES. PREVAILING SOUTHERLY COMPONENT HAS BEEN STRONG ENOUGH TO PREVENT ANY EASTWARD DRIFT OF THE THE BOUNDARY THUS FAR...SPARING MY NORTHWEST COUNTIES. LATEST RAP INDICATES THAT WILL CONTINUE TO BE THE CASE FOR THE REST OF THE EVENING...WITH POPS RAMPING UP AFTER MIDNIGHT AND INCREASING FROM WEST TO EAST THEREAFTER. THIS ACTIVITY COMES ALONG THE LEADING EDGE OF A STRENGTHENING 40-50KT 850 MB JET AND ANOMALOUS BUT FAIRLY NARROW PLUME OF DEEPER LAYER MOISTURE (~1.65" PW) TRACKING TO THE ALLEGHENY FRONT BY 12Z SUN. SO... WILL KEEP POPS UP ALONG MY WESTERN AND NORTHWESTERN BORDERS OVERNIGHT. AS PREVIOUSLY MENTIONED...POTENTIAL FOR SOME HEAVIER DOWNPOURS AS PWATS REMAIN ABOVE NORMAL. TEMPS REMAIN MILD OVERNIGHT IN SW FLOW...WITH HUMID LOWS ONLY FALLING INTO THE 60S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... AN APPROACHING COLD FRONT WILL BRING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ON SUNDAY...EARLIER IN THE WEST AND FROM MIDDAY ON IN THE EAST. WE COULD BE DEALING WITH SOME SEVERE STORMS...ESPECIALLY OVER EASTERN AREAS WHERE OPERATIONAL MODELS ARE SURPRISINGLY AGGRESSIVE IN DEVELOPING THE INSTABILITY. IF ENOUGH SUN CAN BREAK THROUGH...WINDS ALOFT ARE PRETTY IMPRESSIVE AND STRONG WIND GUSTS COULD MATERIALIZE. HIGH TEMPS FOR SUNDAY ARE EXPECTED TO BE IN THE LOWER TO MID 80S OVERALL BUT THE RAIN-COOLED WILL SEE HIGHS REACHING THE MID TO UPPER 70S. IT SHOULD BE THE LAST WIDESPREAD VERY WARM AND HUMID DAY FOR A WHILE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... HIGH PROBABILITY FORECASTS FROM ENSEMBLES IMPLIES THE FRONT IS THROUGH PA IN THE 00 TO 1200 UTC TIME-FRAME MONDAY. BY ABOUT 0600 UTC MONDAY THE PRECIPITABLE WATER (PW) VALUES SHOULD BE AT OR SLIGHTLY BELOW NORMAL. THIS IMPLIES MOST OF THE RESIDUAL SHOWER ACTIVITY FROM SUNDAY SHOULD PUSH TO THE EAST A FEW HOURS EITHER SIDE OF MIDNIGHT. BY MONDAY EVENING THE PW FALLS TO -1SIGMA BELOW NORMAL IMPLYING COOL DRY CONDITIONS MONDAY NIGHT AND TUESDAY. PW SHOULD RETURN TOWARD NORMAL SOMETIME WEDNESDAY IMPLYING A GOOD 2-3 DAYS OF DRY WEATHER BEHIND THE FRONT. THE COLD AIR AND LOW-LEVEL ANTICYCLONE LAG THE DRY AIR IMPLYING TUESDAY MORNING COULD BE THE COLDEST MORNING WHEN 850 HPA TEMPS WILL BE BELOW NORMAL. THE HIGH PRESSURE BUILDS IN TUES-WED SO SHOULD BE CHILLY OVERNIGHT WEDNESDAY TOO. AS THE ANTICYCLONE SORT OF HANGS UP TO OUR NORTHEAST WE SHOULD GET A STABLE SITUATION WITH EASTERLY FLOW...SETTING UP A NICE BOUNDARY..THEN THE FIRST SURGE OF MOISTURE COMES OVER WESTERN PA POTENTIALLY OVERNIGHT WEDNESDAY OR THURSDAY IMPLYING INCREASE IN SHOWERS BY THURSDAY IN THE WEST...STILL LIGHT AND NOT A SIGNIFICANT THREAT. WITH THE HIGH TO THE EAST COULD BE A CLOUDY PERIOD OVER WEST/CENTRAL AREAS AS WE HAVE AN IMPLIED BOUNDARY TO FOCUS CLOUDS AND OVERRUNNING SHOWERS. BETWEEN THE MOISTURE OVER THE SW ATLANTIC AND THE IMPLIED BOUNDARY PUSHING INTO PA FROM THE WEST...MOISTURE AND SHOWER POTENTIAL SHOULD INCREASE THURSDAY INTO FRIDAY. IF THE BOUNDARY CAN PUSH THROUGH FRIDAY OR EARLY SATURDAY WE HAVE THE POTENTIAL FOR A GOOD WEEKEND. GEFS/CMCE IMPLY THAT A LOW-LEVEL JET AND MOISTURE PLUME PUSH THROUGH FRIDAY AHEAD OF THIS FRONTAL BOUNDARY. SO...DRYING OUT FAST MONDAY AROUND MIDNIGHT...DRY PERIOD MONDAY THROUGH WED AND TEMPS NEAR OR SLIGHTLY BELOW NORMAL...THEN INCREASING CHANCE SHOWERS. BEST CHANCE RAIN AT THIS TIME WOULD BE IN THE LATE THURSDAY EARLY SATURDAY TIME-FRAME. WHICH WILL CHANGE. && .AVIATION /01Z SUNDAY THROUGH THURSDAY/... EARLY EVENING VISIBLE SATL IMAGERY SHOWING SOME VERTICAL DEVELOPMENT TO LINE OF CU ALONG THE SPINE OF THE APPALACHIANS FROM AOO TO UNV AND IPT. CAN/T RULE OUT AN ISOLD SHRA/TSRA AT THESE AIRFIELDS EARLY THIS EVENING. HOWEVER...CHANCE TOO SMALL TO WARRANT MENTION IN TAFS ATTM. A CORRIDOR OF GREATER MOISTURE AND WINDS ALOFT WILL PUSH INTO NW PA LATE TONIGHT...RESULTING IN A GREATER CHC OF LATE NIGHT SHRA/TSRA AT BFD. ELSEWHERE...EXPECT GENERALLY GOOD FLYING CONDS OVERNIGHT WITH WIDESPREAD VFR CONDS AND LGT WINDS. AS HAS OCCURRED THE LAST COUPLE MORNINGS...A BIT OF FOG IS POSSIBLE ARND DAWN AT LNS. THE AFOREMENTIONED CORRIDOR OF MOISTURE AND WINDS ALOFT WILL BRING SHOWERS AND THE POTENTIAL OF MVFR CIGS TO THE CENTRAL MTNS DURING THE LATE MORNING HOURS. BY AFTERNOON...DIURNAL HEATING/STEEPENING LAPSE RTS SHOULD CAUSE ANY CIGS TO RISE ABV 3 KFT. HOWEVER...THE THREAT TO AVIATION WILL SHIFT TOWARD THE POTENTIAL OF LOCALLY STRONG THUNDERSTORMS...ESP OVR THE EASTERN HALF OF THE STATE. A SLOW-MOVING COLD FRONT WILL SAG SE ACROSS THE REGION SUNDAY EVENING...BRINGING DRIER AIR AND ENDING THE THREAT OF TSRA FROM NW TO SE. OUTLOOK... MON...LOW CIGS/FOG POSS EARLY OVR W MTNS. TUE-WED...NO SIG WX EXPECTED. THU...ISOLD PM THUNDERSTORM IMPACTS POSS W MTNS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/RXR NEAR TERM...DEVOIR/RXR SHORT TERM...RXR LONG TERM...GRUMM AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
806 PM EDT SAT JUN 1 2013 .SYNOPSIS... A STRONG RIDGE AND RELATIVELY WARM MOIST AIR OVER OUR REGION WILL BE DISPLACED BY A FRONTAL SYSTEM SUNDAY. BEHIND THE FRONT AND OVER THE COMING WEEK A TROUGH WILL DOMINATE OUR REGION WITH GENERALLY COOLER AND DRIER AIR PREVAILING. OUR BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE AHEAD OF THE FRONTAL SYSTEM SUNDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 600 MB WARM CAP AND DRY AIR ENTRAINMENT ALOFT HAVE PRETTY MUCH TAKEN CARE OF THE ISOLATED SHOWERS WHICH POPPED UP LATE THIS AFTERNOON. LOOKING UPSTREAM...LAKE BREEZE INTERACTION WITH GREATER MOISTURE AND INSTABILITY HAS YIELED SCATTERED STORMS FROM EASTERN OHIO TO THE IMMEDIATE LAKE ERIE AND LAKE ONTARIO SHORELINES. PREVAILING SOUTHERLY COMPONENT HAS BEEN STRONG ENOUGH TO PREVENT ANY EASTWARD DRIFT OF THE THE BOUNDARY...AND SO FAR THE NORTHWEST HAS BEEN SPARED THIS EVENING. LATEST RAP INDICATES THAT WILL CONTINUE TO BE THE CASE FOR THE REST OF THIS EVENING...FOLLOWED BY SOME SCATTERED COVERAGE OF SHOWERS AND ISOLATED THUNDER AFTER MIDNIGHT FROM THE WEST CENTRAL MOUNTAINS TO THE NORTHWEST MOUNTAINS. THIS ACTIVITY COMES ALONG THE LEADING EDGE OF A STRENGTHENING 40-50KT 850 MB JET AND ANOMALOUS BUT FAIRLY NARROW PLUME OF DEEPER LAYER MOISTURE (~1.65" PW) TRACKING TO THE ALLEGHENY FRONT BY 12Z SUN. SO... WILL KEEP POPS UP ALONG MY WESTERN AND NORTHWESTERN BORDERS OVERNIGHT. AS PREVIOUSLY MENTIONED...POTENTIAL FOR SOME HEAVIER DOWNPOURS AS PWATS REMAIN ABOVE NORMAL. TEMPS REMAIN MILD OVERNIGHT IN SW FLOW...WITH HUMID LOWS ONLY FALLING INTO THE 60S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... AN APPROACHING COLD FRONT WILL BRING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ON SUNDAY...EARLIER IN THE WEST AND FROM MIDDAY ON IN THE EAST. WE COULD BE DEALING WITH SOME SEVERE STORMS...ESPECIALLY OVER EASTERN AREAS WHERE OPERATIONAL MODELS ARE SURPRISINGLY AGGRESSIVE IN DEVELOPING THE INSTABILITY. IF ENOUGH SUN CAN BREAK THROUGH...WINDS ALOFT ARE PRETTY IMPRESSIVE AND STRONG WIND GUSTS COULD MATERIALIZE. HIGH TEMPS FOR SUNDAY ARE EXPECTED TO BE IN THE LOWER TO MID 80S OVERALL BUT THE RAIN-COOLED WILL SEE HIGHS REACHING THE MID TO UPPER 70S. IT SHOULD BE THE LAST WIDESPREAD VERY WARM AND HUMID DAY FOR A WHILE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... HIGH PROBABILITY FORECASTS FROM ENSEMBLES IMPLIES THE FRONT IS THROUGH PA IN THE 00 TO 1200 UTC TIME-FRAME MONDAY. BY ABOUT 0600 UTC MONDAY THE PRECIPITABLE WATER (PW) VALUES SHOULD BE AT OR SLIGHTLY BELOW NORMAL. THIS IMPLIES MOST OF THE RESIDUAL SHOWER ACTIVITY FROM SUNDAY SHOULD PUSH TO THE EAST A FEW HOURS EITHER SIDE OF MIDNIGHT. BY MONDAY EVENING THE PW FALLS TO -1SIGMA BELOW NORMAL IMPLYING COOL DRY CONDITIONS MONDAY NIGHT AND TUESDAY. PW SHOULD RETURN TOWARD NORMAL SOMETIME WEDNESDAY IMPLYING A GOOD 2-3 DAYS OF DRY WEATHER BEHIND THE FRONT. THE COLD AIR AND LOW-LEVEL ANTICYCLONE LAG THE DRY AIR IMPLYING TUESDAY MORNING COULD BE THE COLDEST MORNING WHEN 850 HPA TEMPS WILL BE BELOW NORMAL. THE HIGH PRESSURE BUILDS IN TUES-WED SO SHOULD BE CHILLY OVERNIGHT WEDNESDAY TOO. AS THE ANTICYCLONE SORT OF HANGS UP TO OUR NORTHEAST WE SHOULD GET A STABLE SITUATION WITH EASTERLY FLOW...SETTING UP A NICE BOUNDARY..THEN THE FIRST SURGE OF MOISTURE COMES OVER WESTERN PA POTENTIALLY OVERNIGHT WEDNESDAY OR THURSDAY IMPLYING INCREASE IN SHOWERS BY THURSDAY IN THE WEST...STILL LIGHT AND NOT A SIGNIFICANT THREAT. WITH THE HIGH TO THE EAST COULD BE A CLOUDY PERIOD OVER WEST/CENTRAL AREAS AS WE HAVE AN IMPLIED BOUNDARY TO FOCUS CLOUDS AND OVERRUNNING SHOWERS. BETWEEN THE MOISTURE OVER THE SW ATLANTIC AND THE IMPLIED BOUNDARY PUSHING INTO PA FROM THE WEST...MOISTURE AND SHOWER POTENTIAL SHOULD INCREASE THURSDAY INTO FRIDAY. IF THE BOUNDARY CAN PUSH THROUGH FRIDAY OR EARLY SATURDAY WE HAVE THE POTENTIAL FOR A GOOD WEEKEND. GEFS/CMCE IMPLY THAT A LOW-LEVEL JET AND MOISTURE PLUME PUSH THROUGH FRIDAY AHEAD OF THIS FRONTAL BOUNDARY. SO...DRYING OUT FAST MONDAY AROUND MIDNIGHT...DRY PERIOD MONDAY THROUGH WED AND TEMPS NEAR OR SLIGHTLY BELOW NORMAL...THEN INCREASING CHANCE SHOWERS. BEST CHANCE RAIN AT THIS TIME WOULD BE IN THE LATE THURSDAY EARLY SATURDAY TIME-FRAME. WHICH WILL CHANGE. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... EARLY EVENING VISIBLE SATL IMAGERY SHOWING SOME VERTICAL DEVELOPMENT TO LINE OF CU ALONG THE SPINE OF THE APPALACHIANS FROM AOO TO UNV AND IPT. CAN/T RULE OUT AN ISOLD SHRA/TSRA AT THESE AIRFIELDS EARLY THIS EVENING. HOWEVER...CHANCE TOO SMALL TO WARRANT MENTION IN TAFS ATTM. A CORRIDOR OF GREATER MOISTURE AND WINDS ALOFT WILL PUSH INTO NW PA LATE TONIGHT...RESULTING IN A GREATER CHC OF LATE NIGHT SHRA/TSRA AT BFD. ELSEWHERE...EXPECT GENERALLY GOOD FLYING CONDS OVERNIGHT WITH WIDESPREAD VFR CONDS AND LGT WINDS. AS HAS OCCURRED THE LAST COUPLE MORNINGS...A BIT OF FOG IS POSSIBLE ARND DAWN AT LNS. THE AFOREMENTIONED CORRIDOR OF MOISTURE AND WINDS ALOFT WILL BRING SHOWERS AND THE POTENTIAL OF MVFR CIGS TO THE CENTRAL MTNS DURING THE LATE MORNING HOURS. BY AFTERNOON...DIURNAL HEATING/STEEPENING LAPSE RTS SHOULD CAUSE ANY CIGS TO RISE ABV 3 KFT. HOWEVER...THE THREAT TO AVIATION WILL SHIFT TOWARD THE POTENTIAL OF LOCALLY STRONG THUNDERSTORMS...ESP OVR THE EASTERN HALF OF THE STATE. A SLOW-MOVING COLD FRONT WILL SAG SE ACROSS THE REGION SUNDAY EVENING...BRINGING DRIER AIR AND ENDING THE THREAT OF TSRA FROM NW TO SE. OUTLOOK... MON...LOW CIGS/FOG POSS EARLY OVR W MTNS. TUE-WED...NO SIG WX EXPECTED. THU...ISOLD PM THUNDERSTORM IMPACTS POSS W MTNS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/RXR NEAR TERM...DEVOIR/RXR SHORT TERM...RXR LONG TERM...GRUMM AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
736 PM EDT SAT JUN 1 2013 .SYNOPSIS... A STRONG RIDGE AND RELATIVELY WARM MOIST AIR OVER OUR REGION WILL BE DISPLACED BY A FRONTAL SYSTEM SUNDAY. BEHIND THE FRONT AND OVER THE COMING WEEK A TROUGH WILL DOMINATE OUR REGION WITH GENERALLY COOLER AND DRIER AIR PREVAILING. OUR BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE AHEAD OF THE FRONTAL SYSTEM SUNDAY. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 600 MB WARM CAP AND DRY AIR ENTRAINMENT ALOFT HAVE PRETTY MUCH TAKEN CARE OF THE ISOLATED SHOWERS WHICH POPPED UP LATE THIS AFTERNOON. LOOKING UPSTREAM...LAKE BREEZE INTERACTION WITH GREATER MOISTURE AND INSTABILITY HAS YIELED SCATTERED STORMS FROM EASTERN OHIO TO THE IMMEDIATE LAKE ERIE AND LAKE ONTARIO SHORELINES. PREVAILING SOUTHERLY COMPONENT HAS BEEN STRONG ENOUGH TO PREVENT ANY EASTWARD DRIFT OF THE THE BOUNDARY...AND SO FAR THE NORTHWEST HAS BEEN SPARED THIS EVENING. LATEST RAP INDICATES THAT WILL CONTINUE TO BE THE CASE FOR THE REST OF THIS EVENING...FOLLOWED BY SOME SCATTERED COVERAGE OF SHOWERS AND ISOLATED THUNDER AFTER MIDNIGHT FROM THE WEST CENTRAL MOUNTAINS TO THE NORTHWEST MOUNTAINS. THIS ACTIVITY COMES ALONG THE LEADING EDGE OF A STRENGTHENING 40-50KT 850 MB JET AND ANOMALOUS BUT FAIRLY NARROW PLUME OF DEEPER LAYER MOISTURE (~1.65" PW) TRACKING TO THE ALLEGHENY FRONT BY 12Z SUN. SO... WILL KEEP POPS UP ALONG MY WESTERN AND NORTHWESTERN BORDERS OVERNIGHT. AS PREVIOUSLY MENTIONED...POTENTIAL FOR SOME HEAVIER DOWNPOURS AS PWATS REMAIN ABOVE NORMAL. TEMPS REMAIN MILD OVERNIGHT IN SW FLOW...WITH HUMID LOWS ONLY FALLING INTO THE 60S. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... AN APPROACHING COLD FRONT WILL BRING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ON SUNDAY...EARLIER IN THE WEST AND FROM MIDDAY ON IN THE EAST. WE COULD BE DEALING WITH SOME SEVERE STORMS...ESPECIALLY OVER EASTERN AREAS WHERE OPERATIONAL MODELS ARE SURPRISINGLY AGGRESSIVE IN DEVELOPING THE INSTABILITY. IF ENOUGH SUN CAN BREAK THROUGH...WINDS ALOFT ARE PRETTY IMPRESSIVE AND STRONG WIND GUSTS COULD MATERIALIZE. HIGH TEMPS FOR SUNDAY ARE EXPECTED TO BE IN THE LOWER TO MID 80S OVERALL BUT THE RAIN-COOLED WILL SEE HIGHS REACHING THE MID TO UPPER 70S. IT SHOULD BE THE LAST WIDESPREAD VERY WARM AND HUMID DAY FOR A WHILE. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... HIGH PROBABILITY FORECASTS FROM ENSEMBLES IMPLIES THE FRONT IS THROUGH PA IN THE 00 TO 1200 UTC TIME-FRAME MONDAY. BY ABOUT 0600 UTC MONDAY THE PRECIPITABLE WATER (PW) VALUES SHOULD BE AT OR SLIGHTLY BELOW NORMAL. THIS IMPLIES MOST OF THE RESIDUAL SHOWER ACTIVITY FROM SUNDAY SHOULD PUSH TO THE EAST A FEW HOURS EITHER SIDE OF MIDNIGHT. BY MONDAY EVENING THE PW FALLS TO -1SIGMA BELOW NORMAL IMPLYING COOL DRY CONDITIONS MONDAY NIGHT AND TUESDAY. PW SHOULD RETURN TOWARD NORMAL SOMETIME WEDNESDAY IMPLYING A GOOD 2-3 DAYS OF DRY WEATHER BEHIND THE FRONT. THE COLD AIR AND LOW-LEVEL ANTICYCLONE LAG THE DRY AIR IMPLYING TUESDAY MORNING COULD BE THE COLDEST MORNING WHEN 850 HPA TEMPS WILL BE BELOW NORMAL. THE HIGH PRESSURE BUILDS IN TUES-WED SO SHOULD BE CHILLY OVERNIGHT WEDNESDAY TOO. AS THE ANTICYCLONE SORT OF HANGS UP TO OUR NORTHEAST WE SHOULD GET A STABLE SITUATION WITH EASTERLY FLOW...SETTING UP A NICE BOUNDARY..THEN THE FIRST SURGE OF MOISTURE COMES OVER WESTERN PA POTENTIALLY OVERNIGHT WEDNESDAY OR THURSDAY IMPLYING INCREASE IN SHOWERS BY THURSDAY IN THE WEST...STILL LIGHT AND NOT A SIGNIFICANT THREAT. WITH THE HIGH TO THE EAST COULD BE A CLOUDY PERIOD OVER WEST/CENTRAL AREAS AS WE HAVE AN IMPLIED BOUNDARY TO FOCUS CLOUDS AND OVERRUNNING SHOWERS. BETWEEN THE MOISTURE OVER THE SW ATLANTIC AND THE IMPLIED BOUNDARY PUSHING INTO PA FROM THE WEST...MOISTURE AND SHOWER POTENTIAL SHOULD INCREASE THURSDAY INTO FRIDAY. IF THE BOUNDARY CAN PUSH THROUGH FRIDAY OR EARLY SATURDAY WE HAVE THE POTENTIAL FOR A GOOD WEEKEND. GEFS/CMCE IMPLY THAT A LOW-LEVEL JET AND MOISTURE PLUME PUSH THROUGH FRIDAY AHEAD OF THIS FRONTAL BOUNDARY. SO...DRYING OUT FAST MONDAY AROUND MIDNIGHT...DRY PERIOD MONDAY THROUGH WED AND TEMPS NEAR OR SLIGHTLY BELOW NORMAL...THEN INCREASING CHANCE SHOWERS. BEST CHANCE RAIN AT THIS TIME WOULD BE IN THE LATE THURSDAY EARLY SATURDAY TIME-FRAME. WHICH WILL CHANGE. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... HEATING OF THE DAY WILL PRODUCE ISOLATED SHRA/TSRA ACROSS CENTRAL PA THIS EVENING. AREAL COVERAGE TOO SMALL TO WARRANT MENTION IN TAFS AT MOST AIRFIELDS. HOWEVER...A CORRIDOR OF GREATER INSTABILITY AND WINDS ALOFT ACROSS NW PA WILL RESULT IN A GREATER CHC OF AN EVENING TSRA/SHRA AT BFD. FOR THE REST OF TONIGHT...EXPECT GENERALLY GOOD FLYING CONDS WITH WIDESPREAD VFR CONDS AND LGT WINDS. AS HAS OCCURRED THE LAST COUPLE MORNINGS...A BIT OF FOG IS POSSIBLE ARND DAWN AT LNS. AN APPROACHING COLD FRONT WILL BRING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ON SUNDAY...EARLIER IN THE WEST AND FROM MIDDAY ON IN THE EAST. WE COULD BE DEALING WITH SOME SEVERE STORMS...ESPECIALLY OVER EASTERN AREAS. IF ENOUGH SUN CAN BREAK THROUGH...WINDS ALOFT ARE PRETTY IMPRESSIVE AND STRONG WIND GUSTS COULD MATERIALIZE. OUTLOOK... SUN...COLD FRONTAL PASSAGE. THUNDERSTORM IMPACTS LIKELY. SOME TSTMS MAY BE STRONG...ESP EAST. MON...LOW CIGS/FOG POSS EARLY OVR W MTNS. OTHERWISE VFR. TUE-THU...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...GRUMM/RXR NEAR TERM...DEVOIR/RXR SHORT TERM...RXR LONG TERM...GRUMM AVIATION...FITZGERALD/RXR
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
934 PM EDT SAT JUN 1 2013 .DISCUSSION...LINE OF THUNDERSTORMS AHEAD OF COLD FRONT MOVING INTO LOWER MS VALLEY WAS ACROSS MIDDLE TN LATE THIS AFTERNOON AND HAS NOW WEAKENED AS IT MOVES ACROSS THE PLATEAU. SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED AHEAD OF THE LINE AND HAVE MOVED ACROSS THE SOUTHWEST HALF OF THE AREA. CURRENT FORECAST LOOKS ABOUT RIGHT. INCREASED POPS SLIGHTLY WEST AND ADJUSTED TEMPERATURES AND DEW POINTS DOWN WHERE RAIN HAS OCCURRED. LATEST RUC AND NAM20 GUIDANCE HAS CONVECTION DYING DOWN NEXT COUPLE HOURS AND THEN REFIRING AROUND 9Z AS MAIN SHORT WAVE IMPULSE AHEAD OF COLD FRONT MOVES INTO EAST TN. UPDATED FORECAST ALREADY SENT. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ TD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1234 PM CDT FRI MAY 31 2013 .UPDATE...FOR 18Z AVIATION FORECAST && .AVIATION... MESO CONVECTIVE VORTICITY CENTER ROTATING OVER WEST CENTRAL KENTUCKY AT 17Z WILL CONTINUE TO LIFT NORTHEAST. BULK OF SHOWERS AND ISOLATED STORMS ARE PULLING AWAY FROM MIDDLE TENNESSEE AS MCV LIFTS NORTHEASTWARD LEAVING SUBSIDENCE BEHIND IT. AM SEEING SCATTERED CONVECTION FIRING EAST OF INTERSTATE 65 BUT NOT EXPECTING THIS TO AMOUNT TO MUCH. BASICALLY EXPECT AIR MASS ACROSS MIDDLE TENNESSEE TO BEGIN DRYING OUT DURING THE AFTERNOON AND CONTINUE THROUGH THE OVERNIGHT IN THE WAKE OF MCV. BOYD && .PREV DISCUSSION... /ISSUED 948 AM CDT FRI MAY 31 2013/ UPDATE... LATEST RADAR AND IR SATELLITE IMAGERY DEPICTS A WEAKENING MCS OVER WESTERN ZONES WITH SHOWERS AND STORMS DIMINISHING IN COVERAGE AND CLOUD TOPS WARMING SIGNIFICANTLY. ALTHOUGH HRRR INDICATES ACTIVITY WILL CONTINUE MARCHING EASTWARD THROUGH THE CWA...APPEARS MUCH OF THE CURRENT PRECIP WILL DISSIPATE PRIOR TO REACHING THE I-65 CORRIDOR. NEVERTHELESS...VERY MOIST AIRMASS IN PLACE SHOWN BY THE PWAT OF 1.67 INCHES ON THE 12Z OHX SOUNDING ALONG WITH CONTINUED DAYTIME HEATING SHOULD SPAWN ADDITIONAL SCATTERED SHOWERS AND STORMS AHEAD OF DYING MCS LATER TODAY. HAVE RAISED POPS ACROSS CENTRAL AND WESTERN ZONES FOR THE MORNING HOURS BASED ON CURRENT TRENDS...AND BUMPED UP CLOUD COVER AND LOWERED HIGH TEMPS IN THE NORTHWEST. REST OF FORECAST REMAINS UNCHANGED. SHAMBURGER PREV DISCUSSION... /ISSUED 831 AM CDT FRI MAY 31 2013/ AVIATION UPDATE... GOOD ROUND OF SHOWERS AND STORMS OVER WESTERN TENNESSEE HAVE MOVED INTO NORTHWEST TENNESSEE WITH ISOLATED RENEGADE SHOWERS FIXING TO MOVE INTO DAVIDSON COUNTY. H-TRIPLE-R DRIVE SHOWERS AND STORMS CURRENTLY IN WEST TENNESSEE EASTWARD AS WE GO THROUGH THE MORNING HOURS. INFRARED SATELLITE LOOP SHOW TOPS WARMING ACROSS WESTERN TENNESSEE WITH LIGHTNING STRIKES DECREASING. BOYD PREV DISCUSSION... /ISSUED 622 AM CDT FRI MAY 31 2013/ UPDATE...FOR 12Z AVIATION DISCUSSION. AVIATION...12Z AVIATION DISCUSSION. UNCERTAINTIES...HOW FAR WILL MOISTURE ASSOCIATED WITH DYING MCS MAKE IT INTO MID STATE AND ASSOCIATED SHWR/TSTMS CHANCES. WILL GO WITH VFR CEILINGS THRU 01/12Z...WITH MAIN IMPACT OF SHWRS/TSTMS ACROSS CKV FROM 31/13Z-31/18Z. QUESTION HOW FAR EWD MCS INFLUENCES WILL EXTEND...AND THUS WILL CONTINUE WITH ONLY VCTS REMARKS AT BOTH BNA/CSV. EXPECT SOME ERROSION OF VFR CU CEILINGS AFTER 31/18Z W TO 31/22Z E...WITH AN INCREASE IN MOISTURE AHEAD OF UPPER LEVEL DISTURBANCE ALLOWING FOR SCT/BKN STCU/AC/CI FROM 01/07Z W TO 01/12Z E. PER SFC PRESSURE GRADIENT...EXPECT GUST TO 20KTS POSSIBLE 31/13Z W TO 01/03Z E. PREV DISCUSSION.../ISSUED 554 AM CDT FRI MAY 31 2013/ UPDATE... LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY ACROSS WESTERN AND NORTH CENTRAL ZONES. PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/ MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR TODAY...GREATEST POPS WEST. TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE 40 POPS NW...20 POPS ELSEWHERE. ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA OCCURRING ON SUNDAY. AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT OVERLY IMPRESSIVE. AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED. TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV. IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
948 AM CDT FRI MAY 31 2013 .UPDATE... LATEST RADAR AND IR SATELLITE IMAGERY DEPICTS A WEAKENING MCS OVER WESTERN ZONES WITH SHOWERS AND STORMS DIMINISHING IN COVERAGE AND CLOUD TOPS WARMING SIGNIFICANTLY. ALTHOUGH HRRR INDICATES ACTIVITY WILL CONTINUE MARCHING EASTWARD THROUGH THE CWA...APPEARS MUCH OF THE CURRENT PRECIP WILL DISSIPATE PRIOR TO REACHING THE I-65 CORRIDOR. NEVERTHELESS...VERY MOIST AIRMASS IN PLACE SHOWN BY THE PWAT OF 1.67 INCHES ON THE 12Z OHX SOUNDING ALONG WITH CONTINUED DAYTIME HEATING SHOULD SPAWN ADDITIONAL SCATTERED SHOWERS AND STORMS AHEAD OF DYING MCS LATER TODAY. HAVE RAISED POPS ACROSS CENTRAL AND WESTERN ZONES FOR THE MORNING HOURS BASED ON CURRENT TRENDS...AND BUMPED UP CLOUD COVER AND LOWERED HIGH TEMPS IN THE NORTHWEST. REST OF FORECAST REMAINS UNCHANGED. SHAMBURGER && .PREV DISCUSSION... /ISSUED 831 AM CDT FRI MAY 31 2013/ AVIATION UPDATE... GOOD ROUND OF SHOWERS AND STORMS OVER WESTERN TENNESSEE HAVE MOVED INTO NORTHWEST TENNESSEE WITH ISOLATED RENEGADE SHOWERS FIXING TO MOVE INTO DAVIDSON COUNTY. H-TRIPLE-R DRIVE SHOWERS AND STORMS CURRENTLY IN WEST TENNESSEE EASTWARD AS WE GO THROUGH THE MORNING HOURS. INFRARED SATELLITE LOOP SHOW TOPS WARMING ACROSS WESTERN TENNESSEE WITH LIGHTNING STRIKES DECREASING. BOYD PREV DISCUSSION... /ISSUED 622 AM CDT FRI MAY 31 2013/ UPDATE...FOR 12Z AVIATION DISCUSSION. AVIATION...12Z AVIATION DISCUSSION. UNCERTAINTIES...HOW FAR WILL MOISTURE ASSOCIATED WITH DYING MCS MAKE IT INTO MID STATE AND ASSOCIATED SHWR/TSTMS CHANCES. WILL GO WITH VFR CEILINGS THRU 01/12Z...WITH MAIN IMPACT OF SHWRS/TSTMS ACROSS CKV FROM 31/13Z-31/18Z. QUESTION HOW FAR EWD MCS INFLUENCES WILL EXTEND...AND THUS WILL CONTINUE WITH ONLY VCTS REMARKS AT BOTH BNA/CSV. EXPECT SOME ERROSION OF VFR CU CEILINGS AFTER 31/18Z W TO 31/22Z E...WITH AN INCREASE IN MOISTURE AHEAD OF UPPER LEVEL DISTURBANCE ALLOWING FOR SCT/BKN STCU/AC/CI FROM 01/07Z W TO 01/12Z E. PER SFC PRESSURE GRADIENT...EXPECT GUST TO 20KTS POSSIBLE 31/13Z W TO 01/03Z E. PREV DISCUSSION.../ISSUED 554 AM CDT FRI MAY 31 2013/ UPDATE... LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY ACROSS WESTERN AND NORTH CENTRAL ZONES. PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/ MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR TODAY...GREATEST POPS WEST. TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE 40 POPS NW...20 POPS ELSEWHERE. ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA OCCURRING ON SUNDAY. AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT OVERLY IMPRESSIVE. AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED. TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV. IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
831 AM CDT FRI MAY 31 2013 .MESOSCALE AND AVIATION UPDATE... GOOD ROUND OF SHOWERS AND STORMS OVER WESTERN TENNESSEE HAVE MOVED INTO NORTHWEST TENNESSEE WITH ISOLATED RENEGADE SHOWERS FIXING TO MOVE INTO DAVIDSON COUNTY. H-TRIPLE-R DRIVE SHOWERS AND STORMS CURRENTLY IN WEST TENNESSEE EASTWARD AS WE GO THROUGH THE MORNING HOURS. INFRARED SATELLITE LOOP SHOW TOPS WARMING ACROSS WESTERN TENNESSEE WITH LIGHTNING STRIKES DECREASING. BOYD && .PREV DISCUSSION... /ISSUED 622 AM CDT FRI MAY 31 2013/ UPDATE...FOR 12Z AVIATION DISCUSSION. AVIATION...12Z AVIATION DISCUSSION. UNCERTAINTIES...HOW FAR WILL MOISTURE ASSOCIATED WITH DYING MCS MAKE IT INTO MID STATE AND ASSOCIATED SHWR/TSTMS CHANCES. WILL GO WITH VFR CEILINGS THRU 01/12Z...WITH MAIN IMPACT OF SHWRS/TSTMS ACROSS CKV FROM 31/13Z-31/18Z. QUESTION HOW FAR EWD MCS INFLUENCES WILL EXTEND...AND THUS WILL CONTINUE WITH ONLY VCTS REMARKS AT BOTH BNA/CSV. EXPECT SOME ERROSION OF VFR CU CEILINGS AFTER 31/18Z W TO 31/22Z E...WITH AN INCREASE IN MOISTURE AHEAD OF UPPER LEVEL DISTURBANCE ALLOWING FOR SCT/BKN STCU/AC/CI FROM 01/07Z W TO 01/12Z E. PER SFC PRESSURE GRADIENT...EXPECT GUST TO 20KTS POSSIBLE 31/13Z W TO 01/03Z E. PREV DISCUSSION.../ISSUED 554 AM CDT FRI MAY 31 2013/ UPDATE... LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY ACROSS WESTERN AND NORTH CENTRAL ZONES. PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/ MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR TODAY...GREATEST POPS WEST. TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE 40 POPS NW...20 POPS ELSEWHERE. ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA OCCURRING ON SUNDAY. AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT OVERLY IMPRESSIVE. AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED. TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV. IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 01
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
622 AM CDT FRI MAY 31 2013 .UPDATE...FOR 12Z AVIATION DISCUSSION. && .AVIATION...12Z AVIATION DISCUSSION. UNCERTAINTIES...HOW FAR WILL MOISTURE ASSOCIATED WITH DYING MCS MAKE IT INTO MID STATE AND ASSOCIATED SHWR/TSTMS CHANCES. WILL GO WITH VFR CEILINGS THRU 01/12Z...WITH MAIN IMPACT OF SHWRS/TSTMS ACROSS CKV FROM 31/13Z-31/18Z. QUESTION HOW FAR EWD MCS INFLUENCES WILL EXTEND...AND THUS WILL CONTINUE WITH ONLY VCTS REMARKS AT BOTH BNA/CSV. EXPECT SOME ERROSION OF VFR CU CEILINGS AFTER 31/18Z W TO 31/22Z E...WITH AN INCREASE IN MOISTURE AHEAD OF UPPER LEVEL DISTURBANCE ALLOWING FOR SCT/BKN STCU/AC/CI FROM 01/07Z W TO 01/12Z E. PER SFC PRESSURE GRADIENT...EXPECT GUST TO 20KTS POSSIBLE 31/13Z W TO 01/03Z E. && .PREV DISCUSSION.../ISSUED 554 AM CDT FRI MAY 31 2013/ UPDATE... LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY ACROSS WESTERN AND NORTH CENTRAL ZONES. PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/ MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR TODAY...GREATEST POPS WEST. TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE 40 POPS NW...20 POPS ELSEWHERE. ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA OCCURRING ON SUNDAY. AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT OVERLY IMPRESSIVE. AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED. TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV. IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
554 AM CDT FRI MAY 31 2013 .UPDATE... LATEST MODELS INDICATING THAT THE DEEPER MOISTURE WILL INDEED TRANSITION NORTHEASTWARD ACROSS OUR NORTHWESTERN COUNTIES LATER THIS MORNING. THIS IS FURTHER CONFIRMED BY RECENT RADAR TRENDS AND TODAY`S HRRR DATA. WILL GO AHEAD AND INCREASE POPS...PRIMARILY ACROSS WESTERN AND NORTH CENTRAL ZONES. && .PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 31 2013/ MAIN COLD FRONTAL BOUNDARY IS STILL LOCATED WELL WEST OF TN AND RESIDES ALONG THE CENTRAL PLAINS. MAIN FOCUS OF CONVECTION THIS MORNING IS IN ASSOCIATION WITH A SERIES OF MCS`S FROM AR NE THROUGH NRN IN. 850MB JET IS COMBINING WITH STRONG IMPULSES WITHIN THE SWLY FLOW ALOFT TO KEEP THIS CONVECTION GOING OVERNIGHT. MODELS DO SHOW AN EASTWARD MIGRATION OF THESE DYNAMICS FOR TODAY. ALTHOUGH THE DYNAMICS WILL WEAKEN...HRRR DOES SUPPORT CONVECTION MOVING INTO OUR NORTHWESTERN ZONES LATER THIS MORNING. CURRENTLY...CONVECTION HAS MOVED INTO FAR WESTERN TN. THUS...POPS OF 30-50 PERCENT FOR TODAY...GREATEST POPS WEST. TONIGHT...COLD FRONT GETS A LITTLE CLOSER BUT AGAIN...THE BETTER MCS COMPLEXES WILL REMAIN NW OF MIDDLE TN. MAY SEE SOME CONVECTIVE ENCROACHMENT ON OUR FAR NW AREAS LATE TONIGHT AND WILL THUS INCLUDE 40 POPS NW...20 POPS ELSEWHERE. ON SATURDAY...COLD FRONT WILL APPROACH THE MS RIVER BY LATE AFTERNOON. MOISTURE AND INSTABILITY WILL BE RAMPING UP ACROSS THE MID STATE AND POPS OF 30-60 PERCENT WILL BE ON ORDER. THE OVERALL SYSTEM WILL BECOME MORE SFC ORIENTED AS THE MID AND UPPER JETS REMAIN NORTH OF TN. NEVERTHELESS..FRONTAL IMPACTS WILL BE FELT...ESPECIALLY ON SATURDAY NIGHT AND SUNDAY...WITH THE FROPA OCCURRING ON SUNDAY. AS FOR SEVERE CHANCES...ELEVATED CAPES WILL CONVERGE WITH FRONTAL BASED SFC FORCING TO PROMOTE A SLIGHT RISK OF SEVERE ON SATURDAY AFT AND EVENING...MAINLY WESTERN ZONES. THEN...AS THE FRONT MOVES THROUGH ON SUNDAY...SEVERE WEATHER WILL BE POSSIBLE ACROSS EASTERN ZONES DURING THE DAY. NOT REALLY SEEING MUCH OVERNIGHT SEVER WEATHER POTENTIAL...UPPER DYNAMICS ARE LOOKING WEAKER AND 850 MB FLOW IS NOT OVERLY IMPRESSIVE. DESCENT QPF TOTALS FOR THE SAT NT OVERNIGHT...BUT OVERALL STORM DEINTENSIFICATION MAY BE THE RULE AS WE LOSE THE DAYTIME HEATING AND THE ELEVATED DYNAMICS ARE NOT OVERLY IMPRESSIVE. AS FOR HEAVY RAINFALL POTENTIAL...LOOKS LIKE STORM TOTAL QPF OF UP TO 2 INCHES IS POSSIBLE NW AREAS...1 TO 2 INCHES ELSEWHERE. THIS IS NOT ESF WORTHY...BUT IT WILL CONTINUE TO BE MONITORED. TEMPERATURE WISE...NO BIG DEVIATIONS VERSUS THE MAV. IN THE EXT FCST...BOUNDARY MOVES THROUGH WITH DRIER POP FREE WEATHER FOR THE EARLY HALF OF THE WORK WEEK. MOISTURE...HOWEVER...WILL RETURN AS THE SFC HIGH SHIFTS EAST AND ALLOWS A SOUTHERLY LOW LEVEL FLOW TO RETURN. TEMPS THROUGH THE EXTENDED ARE LOOKING SEASONAL. .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 87 70 88 70 / 40 20 40 60 CLARKSVILLE 86 69 86 68 / 50 40 60 80 CROSSVILLE 81 66 82 66 / 30 10 40 40 COLUMBIA 87 70 88 70 / 30 10 40 60 LAWRENCEBURG 86 69 87 69 / 30 10 40 60 WAVERLY 87 70 87 68 / 40 40 60 80 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
731 PM CDT SAT JUN 1 2013 .AVIATION... SKIES CLEARING ACROSS THE REGION EXCEPT ALONG THE COAST WHERE 1600-2500 FT SCT SKY COVER IS OBSERVED. COLD FRONT MOVING SOUTHEAST AT 10-11 KNOTS AND CONVECTION HAS BEEN LACKING UNTIL REACHING THE DEEPER MOISTURE AROUND KTYR AND EASTWARD. A COUPLE OF STRONG/SEVERE CELLS IN THE WATCH TO THE WEST OF THE AREA. CONCERNED THAT WITH THE LOSS OF HEATING AND CURRENT CAPPING IN PLACE THAT ONLY A FEW SHOWERS WILL BE SPREAD OUT ALONG THE FRONTAL BOUNDARY AND ANY OUTFLOWS WHEN IT GETS INTO SETX TERMINALS. BEST CHANCES FOR ANY THUNDERSTORMS WILL LIKELY BE IN THE UTS AREA. PATCHY MVFR CIGS SHOULD RETURN TONIGHT MAINLY 06Z AND BEYOND BUT WITH THE WINDS RELAXING SHALLOW FOG ALSO AN A DECENT BET. TIMING OF WIND CHANGE IS VERY PROBLEMATIC AND HAVE GENERALLY GONE WITH A FEW HOURS OF VRB05KT CLL AROUND 03Z-IAH 09Z-GLS 13Z...THEN CONSOLIDATING TO NNE WINDS ABOUT 4 HOURS LATER. RAIN CHANCES LOOK SLIM TOMORROW WITH THE ABUNDANCE OF DRIER AIR...IF ANY PRECIP DEVELOPS IN THE AFTERNOON IT WILL LIKELY HOLD OFF UNTIL SEABREEZE FIGHTS ITS WAY INLAND AFTER 21Z. 45 && .PREV DISCUSSION... /ISSUED 304 PM CDT SAT JUN 1 2013/ DISCUSSION... AT 19Z...A COLD FRONT EXTENDED FROM ABOUT PARIS TO BROWNWOOD TO MIDLAND. A WEAK TROUGH OF LOW PRESSURE EXTENDED FROM TEXARKANA TO ABOUT HUNTSVILLE. THE FRONT WILL CONTINUE TO SLIDE SOUTH TOWARD SE TX OVERNIGHT. NAM 12 FCST SOUNDINGS SHOW PW VALUES APPROACHING 2.00 INCHES AT KCLL AND AROUND 1.8 INCHES AT KIAH WITH LITTLE TO NO CAPPING. DEEP LAYER MOISTURE AND MODEST SURFACE CONVERGENCE SHOULD YIELD A GOOD CHANCE OF RAIN OVER THE NORTH TONIGHT. CONFIDENCE IS LESS CERTAIN OVER THE SOUTHERN HALF OF THE CWA AS SURFACE CONVERGENCE WEAKENS CONSIDERABLY AFTER MIDNIGHT. WILL GO WITH LIKELY POPS OVER THE NORTH AND TAPER TO LOW END CHANCE POPS CENTRAL AND SLIGHT CHANCE ALONG THE COAST. THE RAP INITIALIZED WELL SO WILL LEAN TOWARD THE RAP AND OTHER HI-RES MODELS IN THE SHORT TERM. THERE COULD BE SOME TRAINING OF STORMS OVER THE NORTH TONIGHT AND AM A BIT CONCERNED THAT SOME HEFTY RAINFALL TOTALS WILL BE POSSIBLE NORTH OF A BRENHAM TO TRINITY LINE. WILL REISSUE THE HWO TO HIGHLIGHT THIS POSSIBILITY. MOISTURE LEVELS WANE QUICKLY SUNDAY MORNING. UPPER LEVEL JET ENERGY LOOKS NEUTRAL WITH UPPER LEVEL CONVERGENCE INCREASING DURING SUNDAY AFTN. WILL TRIM POPS FOR SUNDAY AND END ALL RAIN CHANCES BY SUNDAY EVENING. IT STILL LOOKS WARM ON SUNDAY WITH MAX TEMPS NEAR 90 DEGREES. UPPER LEVEL RIDGING TRIES TO BUILD INTO SOUTH TEXAS EARLY NEXT WEEK. WENT CLOSER TO THE WARMER EUROPEAN GUIDANCE. MODELS DIVERGE A BIT TOWARD NEXT WEEKEND. THE ECMWF IS STRONGER WITH SOME S/WV ENERGY ON FRIDAY AND DEEPER WITH AN UPPER LEVEL TROUGH ON SUNDAY. THE GFS AND CANADIAN LOOK SOMEWHAT SIMILAR TO THE ECMWF BUT WEAKER. THE GRIDS HAVE 20 POPS FOR FRI/SAT AND FEEL THAT IS A GOOD PLACE TO START. WILL WAIT AND SEE IF MODELS CAN BUILD A CONSENSUS FOR HIGHER RAIN CHANCES. MARINE... WILL ALLOW THE RIP CURRENT STATEMENT TO EXPIRE AT 00Z AS WINDS CONTINUE TO RELAX. LIGHT EAST TO SOUTHEAST WINDS WILL BE THE NORM THROUGH THE MAJORITY OF NEXT WEEK. THE LACK OF ANY SIGNIFICANT PRESSURE GRADIENT...DUE TO NORTH-NORTHEASTERN CENTERED SURFACE RIDGING...WILL MAINTAIN A TAME MARITIME WIND FIELD. GENERALLY...SEAS HEIGHTS WILL BE AN AVERAGE 2 TO 3 FEET. THERE IS A POSSIBILITY OF A LATE WEEK FAR OFFSHORE SWELL. THIS WILL BE DEPENDENT UPON THE DEVELOPMENT AND EVOLUTION OF AN EASTERN GULF TROUGH OF LOW PRESSURE. 31 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 72 90 66 91 70 / 60 20 10 0 0 HOUSTON (IAH) 75 91 67 92 70 / 40 30 10 0 0 GALVESTON (GLS) 78 87 74 87 76 / 20 30 10 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...38 AVIATION/MARINE...45
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
344 PM CDT FRI MAY 31 2013 .TONIGHT... INSTABILITY WAS HIGH ACROSS WEST CENTRAL TEXAS WITH RAP ML CAPES EXCEEDING 5000 J/KG. A STRONG CAP HOWEVER WAS PREVENTING STORM DEVELOPMENT. I DID ADD A SLIGHT CHANCE OF THUNDERSTORMS IN HASKELL AND THROCKMORTON COUNTIES THIS EVENING...WHERE A CUMULUS FIELD WAS BEGINNING TO DEVELOP IN AN AREA OF WEAK SURFACE CONVERGENCE EAST OF THE DRYLINE. AGAIN...LIKE YESTERDAY...IF STORMS DO DEVELOP...THEY COULD RAPIDLY BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS. A TORNADO IS ALSO NOT OUT OF QUESTION WITH VERY STRONG INSTABILITY PRESENT. OTHERWISE A WARM NIGHT WITH LOW LEVEL MOISTURE CONTINUING TO FLOW FROM THE GULF MEXICO. STRATUS RETURNS AFTER MIDNIGHT...FROM THE HILL COUNTRY. 850 MB LOW LEVEL JET AGAIN PICKS UP TO 45-50 KTS TOWARD MIDNIGHT. PERSISTENCE FORECAST TONIGHT WITH LOWS IN THE LOWER TO MID 70S. .SATURDAY AND SUNDAY... AS THE FRONT PUSHES SOUTH ACROSS THE AREA SATURDAY MORNING...THINGS SHOULD STAY RELATIVELY QUITE. WITH DAYTIME HEATING AND DEWPOINTS AROUND 70 DEGREES...SURFACE BASED CAPE WILL INCREASE TO AROUND 3500 J/KG BY MID AFTERNOON. WITH THE FORCING FROM THE FRONT...REALIZING THIS INSTABILITY SHOULD NOT BE A PROBLEM. THE CIN VALUES ARE REASONABLE...HIGH ENOUGH TO ALLOW THE INSTABILITY TO BUILD...BUT NOT TOO MUCH TO KEEP ANY OF IT FROM BEING RELEASED. SHEAR WILL NOT BE SPECTACULAR...BUT WITH 30 KTS THERE WILL BE ENOUGH FOR SUPPORT VIGOROUS UPDRAFTS. THE MAIN THREAT WILL BE VERY LARGE HAIL. LOW LEVEL SHEAR IS LACKLUSTER...ONLY MAYBE 10 KTS...SO THE TORNADO THREAT SHOULD BE LIMITED...THOUGH IT CANNOT BE RULED OUT. IF A STORM CAN STAY ALONG THE BOUNDARY FOR LONG ENOUGH...IT WILL BE POSSIBLE FOR A CIRCULATION TO DEVELOP. THE MAIN AREA OF CONCERN IS THE SOUTHEASTERN PART OF THE AREA...SOUTH OF A LINE FROM BROWNWOOD...TO SAN ANGELO...TO OZONA. OTHERWISE...TEMPERATURES WILL COOL OFF A LITTLE FROM FRIDAY BEHIND THE FRONT. HIGHS WILL GENERALLY BE IN THE UPPER 80S TO LOWER 90S FOR SATURDAY AND SUNDAY. LOWS WILL IN THE 60S TO LOWER 70S. RAIN CHANCES SHOULD MOVE OUT BY EARLY AFTERNOON ON .SUNDAY NIGHT THROUGH FRIDAY... RIDGE OF HIGH PRESSURE IN THE MID AND UPPER LEVELS ACROSS THE ATMOSPHERE WILL BECOME ESTABLISHED FOR AT LEAST THE FIRST HALF OF NEXT WEEK. TEMPERATURES WILL LIKELY SOAR WITH THE RIDGE...WITH THE LOCATION OF THE THERMAL RIDGE SUGGESTING THAT READINGS AT LEAST NEAR THE 100 DEGREE MARK ARE POSSIBLE FOR THE WESTERN HALF OF THE AREA. THE GFS WEAKENS THE RIDGE FOR THE LAST HALF OF THE WEEK...AND TRIES ANOTHER FRONT AND CONVECTION INTO THE ARE FOR THURSDAY OR FRIDAY. ECMWF SHOWS A LITTLE MORE PERSISTENT RIDGE...AND DELAYS ANY CONVECTION TIL FRIDAY. AT THIS POINT...THINK KEEPING THE FORECAST DRY FOR NOW IS PROBABLY THE BEST OPTION...AND LET THE UNCERTAINTIES SETTLE A LITTLE. && .PRELIMINARY POINT TEMPS/POPS... ABILENE 73 90 65 89 66 / 10 20 30 10 10 SAN ANGELO 74 93 71 91 69 / 5 30 30 20 10 JUNCTION 73 94 70 92 68 / 5 30 40 20 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 04/NR/07
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1241 PM EDT FRI MAY 31 2013 .SYNOPSIS... HIGH PRESSURE WILL KEEP US IN THE SUMMER LIKE HEAT INTO SATURDAY. BY THE END OF THE WEEKEND INTO EARLY NEXT WEEK A FRONTAL SYSTEM WILL ARRIVE WITH INCREASING CHANCES OF SHOWERS AND STORMS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 925 AM EDT FRIDAY... OVERALL PERSISTENCE FORECAST IN STORE THRU THIS AFTERNOON WITH LITTLE CHANGE SEEN ALOFT OFF MORNING SOUNDINGS WHILE PWATS HAVE INCREASED A BIT FROM YDA. HOWEVER FOCUS REMAINS LIMITED GIVEN DRY AIR LINGERING ALOFT UNDER THE CONTINUED 5H RIDGING AND SURFACE HIGH PRESSURE EXTENDING FROM OFFSHORE. HEIGHTS DO FALL A LITTLE THIS AFTERNOON AS MODIFIED CAPES BOUNCE ABOVE 1500-2000 J/KG AND WEAK CONVERGENCE DEVELOPS FAR NW PER SOUTH/SE FLOW. ALSO SOME WEAK MCON LOOKS TO TAKE SHAPE IN THE MORE MOIST LOW LEVEL WEAK RETURN FLOW ACROSS THE FAR SOUTH BUT IFFY WITH COVERAGE AND IF ANY SHRA WILL MAKE IT THIS FAR NORTH. OTRW LATEST HRRR AND RNK-WRF SHOWING VERY ISOLATED COVERAGE MAINLY FAR NW LATER THIS AFTERNOON SO KEEPING A 20/30 POP MENTION GOING DOWN ALONG THE WESTERN SPINE OF THE APPS AND LITTLE ELSW. 12Z THICKNESS CLOSE TO THAT OF THU AND GIVEN SIMILAR 85H TEMPS BUMPED UP HIGHS A FEW DEGREES WITH VALUES AGAIN APPROACHING 90 SE. TONIGHT...CONVECTION WEAKENS/ENDS ACROSS THE WEST AND WILL SEE ANOTHER RIDE UP CLOSE TO THE SRN BLUE RIDGE AND ADJACENT AREAS OF SOME LOWER CLOUDS BUT OVERALL PARTLY CLOUDY. MUGGY LOWS IN THE UPPER 50S TO MID 60S. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... AS OF 300 AM EDT THURSDAY... BERMUDA RIDGING ACROSS THE SOUTHEAST AND MID ATLANTIC STATES WILL BE STRONG ON FRIDAY...RESULTING IN ONLY AN ISOLATED CHANCE OF SHOWERS AND THUNDERSTORMS WITH AFTERNOON HEATING...AND HIGHS REACHING THE MID TO UPPER 80S MOST LOCATIONS. HOWEVER...WILL SEE A TREND WHERE THE RIDGING PATTERN WILL GRADUALLY BREAK DOWN DURING THE WEEKEND AS AN UPPER TROUGH SWINGS FROM THE NORTHERN PLAINS ON SATURDAY OVER THE GREAT LAKES BY SUNDAY. AS SUCH...SHOWER AND THUNDERSTORM ACTIVITY WILL BE WIDELY SCATTERED ACROSS THE MOUNTAINS ON SATURDAY...AND THEN RATHER WIDESPREAD ACROSS THE MOUNTAINS ON SUNDAY AS A COLD FRONT ASSOCIATED WITH THE UPPER TROUGH APPROACHES FROM THE WEST. THE COLD FRONT IS EXPECTED TO PASS SLOWLY ACROSS OUR AREA SUNDAY NIGHT INTO MONDAY. DESPITE THE BREAKDOWN IN RIDGING...AFTERNOON TEMPERATURES FOR SATURDAY AND SUNDAY WILL NOT FALL OFF MUCH AT ALL...RANGING FROM THE MID 80S WEST TO NEAR 90 EAST FOR HIGHS BOTH DAYS. OVERNIGHT TEMPERATURES WILL ALSO REMAIN WARM AND MUGGY THANKS TO THE MOIST SOUTHWESTERLY WIND FLOW DURING THE PERIOD...WITH LOWS FALLING INTO THE 60S MOST LOCATIONS. WILL ALSO KEEP AN EYE OUT FOR PATCHY FOG EARLY EACH MORNING...MAINLY IN THE RIVER VALLEYS AND ACROSS LOCATIONS WHICH RECEIVED SIGNIFICANT RAINFALL FROM SHOWER AND THUNDERSTORM ACTIVITY THE EVENING BEFORE. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM EDT THURSDAY... BLOCKING PATTERN CONTINUES TO RELAX ON MONDAY AS MID CONUS TROUGH LIFTS NORTHEAST THROUGH THE GREAT LAKES AND INTO NEW ENGLAND. THIS WILL ALLOW THE ACCOMPANYING SURFACE FRONT TO MOVE EAST CROSSING THE MID ATLANTIC REGION. THE ECMWF IS THE MOST PROGRESSIVE MODEL WITH THIS FEATURE...MOVING IT THROUGH OUR AREA AND OFF THE MID ATLANTIC COAST MONDAY NIGHT. THE GFS IS ABOUT 12 HOURS SLOWER. PREFER THE MORE PROGRESSIVE GUIDANCE WITH THE SURFACE FRONT WELL EAST OF THE FORECAST AREA BY DAYBREAK TUESDAY. FOLLOWING THIS GUIDANCE...SHOWERS AND STORMS ARE EXPECTED TO BECOME MORE NUMEROUS...MORE SO FOR MONDAY AS THE ACTUAL SURFACE FRONT CROSSES THE MID ATLANTIC REGION. WITH THE FRONTAL PASSAGE PROGGED FOR MONDAY...LOOKING AT RETURN OF DRY WEATHER FOR TUESDAY AND THE MIDDLE OF NEXT WEEK...HIGH PRESSURE SLIDING EAST ACROSS THE GREAT LAKES AND PROVIDING US WITH A SOMEWHAT COOLER NORTHERLY FLOW. AIRMASS BEHIND THIS FRONT IS NOT NEARLY AS COOL AS WHAT TRANSPIRED OVER THE MEMORIAL DAY HOLIDAY WEEKEND...85H TEMPS ONLY DROPPING TO AROUND +8 TO +10 DEG C. RETURN FLOW SHOULD DEVELOP FOR THE LATTER HALF OF NEXT WEEK...WINDS BECOMING SOUTHERLY ON THE BACK SIDE OF THE SURFACE HIGH...TEMPERATURES WARMING. THIS WEEKEND IS THE OFFICIAL START OF THE 2013 HURRICANE SEASON. EXPECTATIONS ARE FOR AN ABOVE NORMAL SEASON. THIS IS BASED ON SEA SURFACE TEMPERATURES THAT ARE WARMER THAN NORMAL IN THE TROPICAL ATLANTIC AND AN ENSO NEUTRAL PATTERN IN THE PACIFIC. THESE FACTORS, ALONG WITH OTHER HEMISPHERIC DECADAL AND INTER-SEASONAL OSCILLATIONS ARE SIGNALS FOR AN ACTIVE STORM SEASON. LONG TRACKING STORMS WILL BE MORE COMMON THIS YEAR THAN IN 2012 FAVORING FORMATION IN THE INTERTROPICAL CONVERGENCE ZONE. AS SUCH...THE RISK FOR CAT 3, CAT 4, AND CAT 5 HURRICANES IS GREATER THIS YEAR THAN IN PREVIOUS YEARS. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... AS OF 1220 PM EDT FRIDAY... PREVAILING VFR WILL CONTINUE ACROSS THE REGION THIS AFTERNOON INTO SATURDAY. HOWEVER SOME CU/TCU WILL FORM THIS AFTERNOON ESPECIALLY ACROSS THE MOUNTAINS. A FEW COULD FORM INTO SHOWERS OR THUNDERSTORMS ALTHOUGH COVERAGE STILL LOOKS TO BE SPARSE. KBLF/KLWB STILL STAND THE BEST CHANCE BUT SINCE SHOULD BE ISOLATED...WILL CONTINUE TO LEAVE OUT OF THE TAFS. MOISTURE FETCH WILL AGAIN INCREASE OVERNIGHT SIMILAR TO LAST NIGHT WITH POTENTIAL TO SEE LOWER CIGS INCLUDING SOME STRATUS SPREAD NE INTO SOUTHERN PORTIONS OF THE AREA LATE. LATEST NAM AGAIN LATCHES ON TO THIS SCENARIO BUT WAS OVERDONE FOR THE MOST PART LAST NIGHT GIVEN DRY AIR IN PLACE. HOWEVER LOW LEVEL MOISTURE RETURN LOOKS A BIT MORE ROBUST TONIGHT ESPCLY WITH DEWPOINTS ON THE RISE SO PLAN TO ADD IN A BIT MORE LOW END VFR/MVFR CIGS IN SPOTS TONIGHT. FOG WILL AGAIN BE AN ISSUE AT KLWB AND PERHAPS KBCB IF THE LOWER CLOUDS TO DO NOT MOVE IN ALLOWING FOR A PERIOD OF IFR ESPCLY KLWB TOWARD DAYBREAK SATURDAY. MORNIGN CLOUDS SHOULD BE A BIT MORE WIDESPREAD SATURDAY ESPCLY MOUNTAINS WITH PERIODIC VFR CU/AC FIELDS KBCB AND POINTS WEST UNTIL CIGS MIX OUT WITH HEATING IN THE AFTERNOON. WIDELY SCATTERED CONVECTION ALSO POSSIBLE MAINLY SE WVA BUT NOT UNTIL LATER SATURDAY SO LEAVING OUT MENTION EARLY ON. MOISTURE INCREASES EVEN MORE AHEAD OF A FRONT BY LATER SUNDAY AND INTO EARLY NEXT WEEK. APPEARS SHOWERS AND STORMS WILL BRING SUB VFR CONDITIONS TO THE REGION DURING THIS TIME WITH BEST CHANCES OF MVFR/IFR OVER THE MOUNTAIN LOCATIONS SUNDAY AFTERNOON/EVENING AND OUT EAST INTO MONDAY. FRONT PUSHES SLOWLY SE BY TUESDAY ALLOWING A RETURN TO MOSTLY VFR BY THEN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/WP NEAR TERM...JH/WP SHORT TERM...NF LONG TERM...AMS/NF AVIATION...JH/KM/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1015 AM EDT FRI MAY 31 2013 .SYNOPSIS... HIGH PRESSURE WILL KEEP US IN THE SUMMER LIKE HEAT INTO SATURDAY. BY THE END OF THE WEEKEND INTO EARLY NEXT WEEK A FRONTAL SYSTEM WILL ARRIVE WITH INCREASING CHANCES OF SHOWERS AND STORMS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 925 AM EDT FRIDAY... OVERALL PERSISTENCE FORECAST IN STORE THRU THIS AFTERNOON WITH LITTLE CHANGE SEEN ALOFT OFF MORNING SOUNDINGS WHILE PWATS HAVE INCREASED A BIT FROM YDA. HOWEVER FOCUS REMAINS LIMITED GIVEN DRY AIR LINGERING ALOFT UNDER THE CONTINUED 5H RIDGING AND SURFACE HIGH PRESSURE EXTENDING FROM OFFSHORE. HEIGHTS DO FALL A LITTLE THIS AFTERNOON AS MODIFIED CAPES BOUNCE ABOVE 1500-2000 J/KG AND WEAK CONVERGENCE DEVELOPS FAR NW PER SOUTH/SE FLOW. ALSO SOME WEAK MCON LOOKS TO TAKE SHAPE IN THE MORE MOIST LOW LEVEL WEAK RETURN FLOW ACROSS THE FAR SOUTH BUT IFFY WITH COVERAGE AND IF ANY SHRA WILL MAKE IT THIS FAR NORTH. OTRW LATEST HRRR AND RNK-WRF SHOWING VERY ISOLATED COVERAGE MAINLY FAR NW LATER THIS AFTERNOON SO KEEPING A 20/30 POP MENTION GOING DOWN ALONG THE WESTERN SPINE OF THE APPS AND LITTLE ELSW. 12Z THICKNESS CLOSE TO THAT OF THU AND GIVEN SIMILAR 85H TEMPS BUMPED UP HIGHS A FEW DEGREES WITH VALUES AGAIN APPROACHING 90 SE. TONIGHT...CONVECTION WEAKENS/ENDS ACROSS THE WEST AND WILL SEE ANOTHER RIDE UP CLOSE TO THE SRN BLUE RIDGE AND ADJACENT AREAS OF SOME LOWER CLOUDS BUT OVERALL PARTLY CLOUDY. MUGGY LOWS IN THE UPPER 50S TO MID 60S. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... AS OF 300 AM EDT THURSDAY... BERMUDA RIDGING ACROSS THE SOUTHEAST AND MID ATLANTIC STATES WILL BE STRONG ON FRIDAY...RESULTING IN ONLY AN ISOLATED CHANCE OF SHOWERS AND THUNDERSTORMS WITH AFTERNOON HEATING...AND HIGHS REACHING THE MID TO UPPER 80S MOST LOCATIONS. HOWEVER...WILL SEE A TREND WHERE THE RIDGING PATTERN WILL GRADUALLY BREAK DOWN DURING THE WEEKEND AS AN UPPER TROUGH SWINGS FROM THE NORTHERN PLAINS ON SATURDAY OVER THE GREAT LAKES BY SUNDAY. AS SUCH...SHOWER AND THUNDERSTORM ACTIVITY WILL BE WIDELY SCATTERED ACROSS THE MOUNTAINS ON SATURDAY...AND THEN RATHER WIDESPREAD ACROSS THE MOUNTAINS ON SUNDAY AS A COLD FRONT ASSOCIATED WITH THE UPPER TROUGH APPROACHES FROM THE WEST. THE COLD FRONT IS EXPECTED TO PASS SLOWLY ACROSS OUR AREA SUNDAY NIGHT INTO MONDAY. DESPITE THE BREAKDOWN IN RIDGING...AFTERNOON TEMPERATURES FOR SATURDAY AND SUNDAY WILL NOT FALL OFF MUCH AT ALL...RANGING FROM THE MID 80S WEST TO NEAR 90 EAST FOR HIGHS BOTH DAYS. OVERNIGHT TEMPERATURES WILL ALSO REMAIN WARM AND MUGGY THANKS TO THE MOIST SOUTHWESTERLY WIND FLOW DURING THE PERIOD...WITH LOWS FALLING INTO THE 60S MOST LOCATIONS. WILL ALSO KEEP AN EYE OUT FOR PATCHY FOG EARLY EACH MORNING...MAINLY IN THE RIVER VALLEYS AND ACROSS LOCATIONS WHICH RECEIVED SIGNIFICANT RAINFALL FROM SHOWER AND THUNDERSTORM ACTIVITY THE EVENING BEFORE. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 300 AM EDT THURSDAY... BLOCKING PATTERN CONTINUES TO RELAX ON MONDAY AS MID CONUS TROUGH LIFTS NORTHEAST THROUGH THE GREAT LAKES AND INTO NEW ENGLAND. THIS WILL ALLOW THE ACCOMPANYING SURFACE FRONT TO MOVE EAST CROSSING THE MID ATLANTIC REGION. THE ECMWF IS THE MOST PROGRESSIVE MODEL WITH THIS FEATURE...MOVING IT THROUGH OUR AREA AND OFF THE MID ATLANTIC COAST MONDAY NIGHT. THE GFS IS ABOUT 12 HOURS SLOWER. PREFER THE MORE PROGRESSIVE GUIDANCE WITH THE SURFACE FRONT WELL EAST OF THE FORECAST AREA BY DAYBREAK TUESDAY. FOLLOWING THIS GUIDANCE...SHOWERS AND STORMS ARE EXPECTED TO BECOME MORE NUMEROUS...MORE SO FOR MONDAY AS THE ACTUAL SURFACE FRONT CROSSES THE MID ATLANTIC REGION. WITH THE FRONTAL PASSAGE PROGGED FOR MONDAY...LOOKING AT RETURN OF DRY WEATHER FOR TUESDAY AND THE MIDDLE OF NEXT WEEK...HIGH PRESSURE SLIDING EAST ACROSS THE GREAT LAKES AND PROVIDING US WITH A SOMEWHAT COOLER NORTHERLY FLOW. AIRMASS BEHIND THIS FRONT IS NOT NEARLY AS COOL AS WHAT TRANSPIRED OVER THE MEMORIAL DAY HOLIDAY WEEKEND...85H TEMPS ONLY DROPPING TO AROUND +8 TO +10 DEG C. RETURN FLOW SHOULD DEVELOP FOR THE LATTER HALF OF NEXT WEEK...WINDS BECOMING SOUTHERLY ON THE BACK SIDE OF THE SURFACE HIGH...TEMPERATURES WARMING. THIS WEEKEND IS THE OFFICIAL START OF THE 2013 HURRICANE SEASON. EXPECTATIONS ARE FOR AN ABOVE NORMAL SEASON. THIS IS BASED ON SEA SURFACE TEMPERATURES THAT ARE WARMER THAN NORMAL IN THE TROPICAL ATLANTIC AND AN ENSO NEUTRAL PATTERN IN THE PACIFIC. THESE FACTORS, ALONG WITH OTHER HEMISPHERIC DECADAL AND INTER-SEASONAL OSCILLATIONS ARE SIGNALS FOR AN ACTIVE STORM SEASON. LONG TRACKING STORMS WILL BE MORE COMMON THIS YEAR THAN IN 2012 FAVORING FORMATION IN THE INTERTROPICAL CONVERGENCE ZONE. AS SUCH...THE RISK FOR CAT 3, CAT 4, AND CAT 5 HURRICANES IS GREATER THIS YEAR THAN IN PREVIOUS YEARS. && .AVIATION /13Z FRIDAY THROUGH TUESDAY/... AS OF 710 AM EDT FRIDAY... IFR FOG AT LWB EARLY THIS MORNING WILL BE GONE BY 14Z WITH VFR CONDITIONS PREVAILING THE REST OF THE DAY AT ALL TAF SITES. SOME CU/TCU SHOULD FORM THIS AFTERNOON ESPECIALLY ACROSS THE MOUNTAINS. A FEW COULD FORM INTO THUNDERSTORMS ALTHOUGH COVERAGE STILL LOOKS TO BE SPARSE. BLF/LWB STAND THE BEST CHANCE BUT GIVEN NOT BIG A CHANCE...NO MENTION IN THE TAFS. QUESTION TONIGHT WILL BE THE SOUTHERLY FETCH OF MOISTURE THAT HAS BEEN SPREADING SOME LOWER CIGS INTO THE NC MOUNTAINS EARLY THIS MORNING AND IF THEY WILL REACH ACROSS INTO OUR AREA LATE TONIGHT. THE NAM SEEMS TO INDICATE THAT BCB/DAN COULD SEE SOME CIGS SCRAPING THE MVFR THRESHOLD LATE TONIGHT...BUT WILL LEAVE IT SCATTERED AT 3KFT AT BCB AND BKN040 AT DAN. FOG WILL AGAIN BE AN ISSUE AT LWB AND PERHAPS BCB IF THE LOWER CLOUDS TO DO NOT MOVE IN. MOISTURE INCREASES AHEAD OF A FRONT BY LATER SUNDAY AND INTO EARLY NEXT WEEK. A GOOD CHANCE OF SHOWERS AND STORMS WILL BRING SOME OCCASIONAL SUB VFR CONDITIONS TO THE REGION DURING THIS TIME. FRONT PUSHES SLOWLY SE BY TUESDAY ALLOWING A RETURN TO MOSTLY VFR BY THEN. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/WP NEAR TERM...JH/WP SHORT TERM...NF LONG TERM...AMS/NF AVIATION...JH/KM/WP
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1122 AM PDT Fri May 31 2013 .SYNOPSIS... Most of the region will experience dry conditions today and Saturday...coupled with warming temperatures. A relatively strong, but not terribly wet, storm system will bring a cool-down with some showers and breezy conditions this weekend. A dry and warming period will greet the new work week with temperatures increasing into the 80s by Wednesday with dry and warm conditions rounding out next week. && .DISCUSSION... Rest of Today...Water vapor imagery was indicating that the slow moving upper level trough...which brought showers over the past few days...continued to slowly exit the region this morning. Drier air behind the trough was now entrenched the entire region save the northern tip of Idaho. Despite the punch of drier air...relatively shallow instability and moisture remained fixed over the northern tier of the forecast area...roughly from the Okanogan Highlands to the mountains north of Lake Pend Oreille. This has manifested itself as scattered showers...which thus far have been largely terrain induced. Based on HRRR forecast data and model soundings...the instability will remain sufficient for continued shower formation through the afternoon. However the threat will gradually decrease from the southwest as upper level ridging builds in and begins to cap the depth of the convection. Remainder of the forecast area will see primarily sunny conditions with temperatures several degrees warmer than yesterday. fx && .AVIATION... 18Z TAFS: VFR conditions expected at all sites through 18z Saturday. High pressure building in from the southwest will bring stable conditions to the area and begin to limit the shower threat over the mountains north of the GEG-COE corridor. For tonight...the entire region will be precipitation free with mostly clear skies which will persist into Saturday morning. fx && .PRELIMINARY POINT TEMPS/POPS... Spokane 66 45 71 49 67 47 / 0 0 0 30 60 40 Coeur d`Alene 66 42 71 45 66 45 / 0 0 10 30 60 50 Pullman 66 41 71 47 67 44 / 0 0 0 10 30 30 Lewiston 73 46 79 53 74 51 / 0 0 0 10 20 20 Colville 73 42 75 46 69 46 / 20 0 10 50 60 40 Sandpoint 66 39 70 43 66 42 / 20 10 10 30 70 50 Kellogg 61 42 68 47 63 44 / 10 0 0 20 70 50 Moses Lake 74 45 78 50 77 49 / 0 0 0 10 10 10 Wenatchee 73 50 76 52 75 52 / 0 0 0 10 10 0 Omak 73 44 76 46 71 47 / 0 0 20 40 20 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1052 PM CDT SAT JUN 1 2013 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SYNOPSIS... ISSUED AT 254 PM CDT SAT JUN 1 2013 TURNING COOLER AND LESS HUMID...WITH TEMPERATURES RETURNING TO SOMEWHAT BELOW NORMAL LEVELS. UPR PATTERN ACRS NOAM WL TRANSITION BACK INTO A MORE TYPICAL EARLY SUMMER REGIME AS DEEP UPR TROF OVER THE GREAT LAKES RGN SHIFTS OFF TO THE NE. IN ITS WAKE...A LOWER AMPLITUDE AND WEAKER BAND OF WESTERLIES WL REMAIN ACRS THE NRN CONUS. THOUGH INITIALLY PROGRESSIVE...WEAK UPR TROF WL EVENTUALLY SET-UP OVER THE NRN PLAINS OR WESTERN LAKES RGN. THE WARM AND RATHER HUMID AIR STILL LINGERING ACRS THE AREA TDA WL BE REPLACED BY COOLER AND LESS HUMID CONDITIONS IN THE WAKE OF THE DEPARTING UPR TROF. TEMPERATURES WL SETTLE BACK TO BLO NORMAL FOR MOST OF THE REST OF THE PERIOD. THERE WL BE AT LEAST A COUPLE OPPORTUNITIES TO PICK UP SOME PCPN...SO AMOUNTS WL PROBABLY END UP NR NORMAL AT MOST LOCATIONS. && .SHORT TERM...TONIGHT AND SUNDAY ISSUED AT 254 PM CDT SAT JUN 1 2013 PESKY UPPER LOW THAT HAS BROUGHT SEVERAL DAYS OF UNSETTLED WEATHER TO THE FORECAST AREA IS FINALLY ON THE MOVE AND WILL SHIFT EAST ACROSS THE FORECAST AREA OVERNIGHT. THIS WILL FINALLY END THE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY WE HAVE SEEN THE PAST FEW DAYS. NOTABLE INSTABILITY THAT HAS LINGERED ACROSS MAINLY THE EASTERN HALF OF THE FORECAST AREA...IN CONCERT WITH A WEAK SHORT WAVE DISTURBANCE MOVING NORTHEAST TOWARD THE FORECAST AREA...HAS CONTRIBUTED TO A BAND OF SHOWERS AND EMBEDDED THUNDERSTORM ACTIVITY ACROSS THE FOX VALLY NORTHEAST TOWARD ESCANABA MICHIGAN. DESPITE FAVORABLE WETBULB ZERO HEIGHTS AROUND 8500 FEET AGL..ONLY HAVE HAD A COUPLE REPORTS OF SOME PEA SIZE HAIL THUS FAR. WITH PW VALUES STILL AROUND AN INCH...AND UPPER-LEVEL WINDS CONTINUING TO WEAKEN AS UPPER TROUGH MOVES OVERHEAD...EXPECT A FEW OF THESE STORMS TO BE EFFICIENT RAINFALL PRODUCERS PRODUCING SOME BRIEF HEAVY RAINFALL INTO THE EARLY EVENING. 18Z HRRR AND TO A LESSER EXTENT THE GFS AND NAM...FOCUS THE BEST LIFT AND ASSOCIATED QPF OVER THE NORTHEAST PORTION OF THE FORECAST AREA THIS EVENING. THIS SEEMS REASONABLE GIVEN CURRENT RADAR TRENDS...THUS HAVE ADJUSTED THE QPF AND POP ACCORDINGLY FOR THIS EVENING. AS UPPER TROUGH SWEEPS ACROSS THE FORECAST AREA OVERNIGHT...THE ASSOCIATED SURFACE TROUGH AND SCATTERED SHOWER ACTIVITY WILL ALSO STEADILY PROGRESS EASTWARD. BASED ON THE LATEST RUN OF THE HRRR...ANTICIPATE THE SURFACE TROUGH TO MOVE EAST OF THE FOX VALLEY BY AROUND MIDNIGHT. SOME RESIDUAL LOW-LEVEL MOISTURE IN THE WAKE OF THE SURFACE TROUGH MAY CONTRIBUTE TO A FEW LINGERING LIGHT SHOWERS OR SPRINKLES OVER THE LAKE SHORE COUNTIES UNTIL ABOUT 12Z. RESIDUAL LOW LEVEL MOISTURE REALLY DOES NOT GET SCOURED OUT UNTIL AFTER ABOUT 16Z SO HAVE SLOWED CLEARING A FEW HOURS ON SUNDAY. BRISK NORTHWEST WINDS SUNDAY MORNING WILL SLOWLY DIMINISH AS THE DAY PROGRESSES AS SURFACE HIGH PRESSURE SETTLES IN. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY ISSUED AT 254 PM CDT SAT JUN 1 2013 HIGH PRESSURE RIDGING SWD FM CANADA WL DOMINATE THE START OF THE LONG-TERM PERIOD. THAT WL LEAD TO PLENTY OF SUNSHINE AND DRY CONDITIONS. TEMPS WL FALL WELL BLO NORMAL AT NIGHT. LOOKS LIKE A PRETTY GOOD CHC OF FROST ACRS THE N SUNDAY NIGHT...AND SOME OF THE TYPICAL COLD SPOTS COULD EVEN EXPERIENCE A FREEZE. MONDAY NIGHT MAY NOT BE QUITE AS COLD...BUT AT LEAST PATCHY FROST WL AGAIN BE POSSIBLE ACRS THE N. WL PROBABLY EVENTUALLY NEED A FROST/FREEZE HEADLINE FOR THE N FOR SUN NGT...WL HOLD OFF ISSUING THAT NOW AS LATER FORECASTS HAVE A BETTER CHC OF DISCERNING EXACTLY HOW FAR S AND E TO TAKE THE HEADLINE. THE NEXT UPR TROF EMBEDDED IN THE WESTERLIES ACRS THE NRN CONUS WL BE APPROACHING THE AREA TUE. THE MAJORITY OF THE MODELS DROVE PCPN WELL E INTO THE FCST AREA DURING THE DAY. BUT IT SEEMS LIKE DRY AIR WITH THE DEPARTING HIGH PRESSURE SHOULD BE ABLE TO DELAY THE EWD PROGRESSION OF THE PCPN AT LEAST A LITTLE. SO OPTED TO KEEP THE MORNING DRY AND THEN LIMIT POPS TO ABOUT THE WRN 1/4 OF THE FCST AREA DURING THE AFTN. THE BEST CHC OF PCPN WL COME MID-WK AS THE UPR TROF CROSSES THE RGN. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1049 PM CDT SAT JUN 1 2013 MAIN UPPER TROF TO MOVE THROUGH EASTERN WI THROUGH FIRST HALF OF NIGHT. ISOLATED TO SCATTERED SHOWERS NOW MOVING OVER AREA. LOWER MVFR STRATUS TO MOVE IN FOR PERIOD BEHIND SHOWERS...EXITING SUN MORNING AS HIGH PRESSURE MOVES IN. GUSTY NORTHWEST WINDS EXPECTED WITH TROF PASSAGE. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....ESB LONG TERM......SKOWRONSKI AVIATION.......TE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1022 PM CDT SAT JUN 1 2013 .SHORT TERM...(TONIGHT AND SUNDAY TONIGHT) ISSUED AT 218 PM CDT SAT JUN 1 2013 WATER VAPOR IMAGERY SHOWING THE CLOSED LOW SLOWLY FILLING WITH THE MAIN CIRCULATION CENTER ROTATING EAST ALONG THE MN/IA BORDER. AT THE SURFACE...LOW PRESSURE WAS CENTERED OVER SOUTHWEST WI WITH A COLD FRONT/DRYLINE EXTENDING FROM CENTRAL INTO SOUTHWEST WI. STRONGER CONVECTION WAS FIRING AHEAD OF THE DRYLINE OVER EASTERN WI IN AN AXIS OF HIGHER DEWPOINT/INSTABILITY AXIS AND 25-35KT 0-3KM BULK SHEAR. MEANWHILE...RADAR MOSAIC WAS ALSO SHOWING WEAKER SHOWER/THUNDERSTORM ACTIVITY ENTERING THE FORECAST AREA FROM MN ON THE EASTERN PERIPHERY OF STEEPER LOW-MID-LEVEL LAPSE RATES UNDER THE FILLING CLOSED LOW. RAP ANALYSIS SHOWING THIS AREA IN A ZONE OF VERY WEAK BULK SHEAR...SO JUST EXPECTING MOSTLY SHOWER ACTIVITY WITH ISOLATED THUNDER OUT OF THIS ACTIVITY. LOOK FOR THIS CONVECTION TO CONTINUE MOVING INTO THE AREA THROUGH THE REMAINDER OF THIS AFTERNOON AND INTO TONIGHT AS THE MID-LEVEL TROUGH AXIS MOVES EAST ACROSS THE REGION. LOOK FOR THE SHOWERS TO DIMINISH AND SKIES TO CLEAR FROM WEST TO EAST AFTER MIDNIGHT AS SUBSIDENCE/DRYING TAKES PLACE BEHIND THE DEPARTING TROUGH. A RIDGE OF HIGH PRESSURE WILL THEN BUILD INTO THE AREA ON SUNDAY FOR A DRY/MOSTLY SUNNY DAY. DESPITE MOSTLY SUNNY SKIES...COLD AIR ADVECTION ON NORTHWEST WINDS OF 10-20 MPH WILL YIELD HIGH TEMPERATURES SOME 10 DEGREES BELOW NORMAL IN THE LOW/MID 60S. HIGH PRESSURE WILL BE SITUATED OVERHEAD FOR A CLEAR/COOL/CALM SUNDAY NIGHT. LOOK FOR LOWS RANGING FROM AROUND 40 DEGREES FOR AREAS ALONG/NORTHEAST OF I-94...TO THE MID/UPPER 40S ELSEWHERE. GIVEN THE NEARLY SATURATED GROUND AND THE FACT THE HIGH IS OVERHEAD FOR CALM WINDS...WAS THINKING SOME FOG WOULD BE POSSIBLE. HOWEVER...BUFKIT SOUNDINGS SHOWING THAT THERE WILL BE PLENTY OF DRYING DURING THE DAYTIME SUNDAY AND THEN MAINTAIN AT LEAST A 3-5 DEGREE SPREAD THROUGH THE OVERNIGHT HOURS. WILL THEREFORE LEAVE FOG MENTION OUT...BUT MAY BE SOMETHING TO KEEP AN EYE ON. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 218 PM CDT SAT JUN 1 2013 LOOK FOR HIGH PRESSURE TO REMAIN IN CONTROL ACROSS THE AREA THROUGH MONDAY FOR A CONTINUED DRY BREAK FROM THE SOGGY CONDITIONS OF LATE. LATEST GFS/ECMWF IN FAIRLY GOOD AGREEMENT IN BRINGING A COUPLE WEAK MID-LEVEL TROUGHS ACROSS THE NORTHERN PLAINS INTO OUR REGION TUESDAY THROUGH SATURDAY. VERY LITTLE CAPE/INSTABILITY IS INDICATED BY THE MODELS WHICH WOULD LEAD TO MAINLY SHOWER CHANCES WITH PERHAPS AN ISOLATED THUNDERSTORM OR TWO. APPEARS THIS PERIOD WILL ALSO CONTINUE TO BE MARKED BY COOLER THAN NORMAL TEMPERATURE WITH HIGHS GENERALLY IN THE 60S TO LOWER 70S AND OVERNIGHT LOWS IN THE 50S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1022 PM CDT SAT JUN 1 2013 CEILINGS AND WINDS ARE THE MAIN ISSUE FOR THE FORECAST. MVFR STRATUS HAS MOVED INTO BOTH TAF SITES IN THE WAKE OF A COLD FRONTAL PASSAGE. HOWEVER...VFR CEILINGS ARE LURKING UP TO THE NORTHWEST OVER CENTRAL MINNESOTA WHERE NORTHWEST WINDS ARE BRINGING DRIER AIR. THEREFORE...ANTICIPATING CEILINGS TO GRADUALLY CLIMB THROUGH THE MORNING HOURS...BECOMING VFR BY LATE MORNING. ADDITIONALLY...DAYTIME MIXING AND FURTHER DRYING SHOULD HELP CLOUDS SCATTER OUT BY NOON. VFR CONDITIONS WILL THEN PERSIST THROUGH THE EVENING AS HIGH PRESSURE BUILDS INTO THE TAF SITES. BLUSTERY NORTHWEST WINDS ARE EXPECTED TO PERSIST THROUGH MUCH OF THE DAY SUNDAY...DIMINISHING LATE IN THE AFTERNOON WITH THE LOSS OF DAYTIME HEATING AND A WEAKER PRESSURE GRADIENT FROM THE HIGH BUILDING IN. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
649 PM CDT SAT JUN 1 2013 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SYNOPSIS... ISSUED AT 254 PM CDT SAT JUN 1 2013 TURNING COOLER AND LESS HUMID...WITH TEMPERATURES RETURNING TO SOMEWHAT BELOW NORMAL LEVELS. UPR PATTERN ACRS NOAM WL TRANSITION BACK INTO A MORE TYPICAL EARLY SUMMER REGIME AS DEEP UPR TROF OVER THE GREAT LAKES RGN SHIFTS OFF TO THE NE. IN ITS WAKE...A LOWER AMPLITUDE AND WEAKER BAND OF WESTERLIES WL REMAIN ACRS THE NRN CONUS. THOUGH INITIALLY PROGRESSIVE...WEAK UPR TROF WL EVENTUALLY SET-UP OVER THE NRN PLAINS OR WESTERN LAKES RGN. THE WARM AND RATHER HUMID AIR STILL LINGERING ACRS THE AREA TDA WL BE REPLACED BY COOLER AND LESS HUMID CONDITIONS IN THE WAKE OF THE DEPARTING UPR TROF. TEMPERATURES WL SETTLE BACK TO BLO NORMAL FOR MOST OF THE REST OF THE PERIOD. THERE WL BE AT LEAST A COUPLE OPPORTUNITIES TO PICK UP SOME PCPN...SO AMOUNTS WL PROBABLY END UP NR NORMAL AT MOST LOCATIONS. && .SHORT TERM...TONIGHT AND SUNDAY ISSUED AT 254 PM CDT SAT JUN 1 2013 PESKY UPPER LOW THAT HAS BROUGHT SEVERAL DAYS OF UNSETTLED WEATHER TO THE FORECAST AREA IS FINALLY ON THE MOVE AND WILL SHIFT EAST ACROSS THE FORECAST AREA OVERNIGHT. THIS WILL FINALLY END THE SCATTERED SHOWER AND THUNDERSTORM ACTIVITY WE HAVE SEEN THE PAST FEW DAYS. NOTABLE INSTABLITY THAT HAS LINGERED ACROSS MAINLY THE EASTERN HALF OF THE FORECAST AREA...IN CONCERT WITH A WEAK SHORT WAVE DISTURBANCE MOVING NORTHEAST TOWARD THE FORECAST AREA...HAS CONTRIBUTED TO A BAND OF SHOWERS AND EMBEDDED THUNDERSTORM ACTIVITY ACROSS THE FOX VALLY NORTHEAST TOWARD ESCANABA MICHIGAN. DESPITE FAVORABLE WETBULB ZERO HEIGHTS AROUND 8500 FEET AGL..ONLY HAVE HAD A COUPLE REPORTS OF SOME PEA SIZE HAIL THUS FAR. WITH PW VALUES STILL AROUND AN INCH...AND UPPER-LEVEL WINDS CONTINUING TO WEAKEN AS UPPER TROUGH MOVES OVERHEAD...EXPECT A FEW OF THESE STORMS TO BE EFFICIENT RAINFALL PRODUCERS PRODUCING SOME BRIEF HEAVY RAINFALL INTO THE EARLY EVENING. 18Z HRRR AND TO A LESSER EXTENT THE GFS AND NAM...FOCUS THE BEST LIFT AND ASSOCIATED QPF OVER THE NORTHEAST PORTION OF THE FORECAST AREA THIS EVENING. THIS SEEMS REASONABLE GIVEN CURRENT RADAR TRENDS...THUS HAVE ADJUSTED THE QPF AND POP ACCORDINGLY FOR THIS EVENING. AS UPPER TROUGH SWEEPS ACROSS THE FORECAST AREA OVERNIGHT...THE ASSOCIATED SURFACE TROUGH AND SCATTERED SHOWER ACTIVITY WILL ALSO STEADILY PROGRESS EASTWARD. BASED ON THE LATEST RUN OF THE HRRR...ANTICIPATE THE SURFACE TROUGH TO MOVE EAST OF THE FOX VALLEY BY AROUND MIDNIGHT. SOME RESIDUAL LOW-LEVEL MOISTURE IN THE WAKE OF THE SURFACE TROUGH MAY CONTRIBUTE TO A FEW LINGERING LIGHT SHOWERS OR SPRINKLES OVER THE LAKE SHORE COUNTIES UNTIL ABOUT 12Z. RESIDUAL LOW LEVEL MOISTURE REALLY DOES NOT GET SCOURED OUT UNTIL AFTER ABOUT 16Z SO HAVE SLOWED CLEARING A FEW HOURS ON SUNDAY. BRISK NORTHWEST WINDS SUNDAY MORNING WILL SLOWLY DIMINISH AS THE DAY PROGRESSES AS SURFACE HIGH PRESSURE SETTLES IN. .LONG TERM...SUNDAY NIGHT THROUGH SATURDAY ISSUED AT 254 PM CDT SAT JUN 1 2013 HIGH PRESSURE RIDGING SWD FM CANADA WL DOMINATE THE START OF THE LONG-TERM PERIOD. THAT WL LEAD TO PLENTY OF SUNSHINE AND DRY CONDITIONS. TEMPS WL FALL WELL BLO NORMAL AT NIGHT. LOOKS LIKE A PRETTY GOOD CHC OF FROST ACRS THE N SUNDAY NIGHT...AND SOME OF THE TYPICAL COLD SPOTS COULD EVEN EXPERIENCE A FREEZE. MONDAY NIGHT MAY NOT BE QUITE AS COLD...BUT AT LEAST PATCHY FROST WL AGAIN BE POSSIBLE ACRS THE N. WL PROBABLY EVENTUALLY NEED A FROST/FREEZE HEADLINE FOR THE N FOR SUN NGT...WL HOLD OFF ISSUING THAT NOW AS LATER FORECASTS HAVE A BETTER CHC OF DISCERNING EXACTLY HOW FAR S AND E TO TAKE THE HEADLINE. THE NEXT UPR TROF EMBEDDED IN THE WESTERLIES ACRS THE NRN CONUS WL BE APPROACHING THE AREA TUE. THE MAJORITY OF THE MODELS DROVE PCPN WELL E INTO THE FCST AREA DURING THE DAY. BUT IT SEEMS LIKE DRY AIR WITH THE DEPARTING HIGH PRESSURE SHOULD BE ABLE TO DELAY THE EWD PROGRESSION OF THE PCPN AT LEAST A LITTLE. SO OPTED TO KEEP THE MORNING DRY AND THEN LIMIT POPS TO ABOUT THE WRN 1/4 OF THE FCST AREA DURING THE AFTN. THE BEST CHC OF PCPN WL COME MID-WK AS THE UPR TROF CROSSES THE RGN. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 640 PM CDT SAT JUN 1 2013 SURFACE TROF HAS KICKED OFF A LINE OF THUNDERSTORMS OVER EAST CENTRAL AND FAR NORTHEAST WI...LATE THIS AFTERNOON. THE LINE WAS MOVING EAST AT 20 MPH AND WILL AFFECT LAKESHORE AIRPORTS THROUGH 01Z. THE STORMS ARE EXPECTED TO WEAKEN SOMEWHAT AS THEY MOVE EAST. MAIN UPPER TROF TO MOVE THROUGH EASTERN WI THROUGH FIRST HALF OF NIGHT. AREA OF SCATTERED SHOWERS NOW OVER WESTERN WI TO AFFECT MAINLY CENTRAL WI THIS EVENING...SOME QUESTION ON WHETHER WILL HOLD TOGETHER AS IT MOVES FURTHER EAST. LOWER MVFR STRATUS TO MOVE IN FOR PERIOD BEHIND SHOWERS...EXITING SUN MORNING AS HIGH PRESSURE MOVES IN. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......SKOWRONSKI SHORT TERM.....ESB LONG TERM......SKOWRONSKI AVIATION.......TE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
633 PM CDT SAT JUN 1 2013 .SHORT TERM...(TONIGHT AND SUNDAY TONIGHT) ISSUED AT 218 PM CDT SAT JUN 1 2013 WATER VAPOR IMAGERY SHOWING THE CLOSED LOW SLOWLY FILLING WITH THE MAIN CIRCULATION CENTER ROTATING EAST ALONG THE MN/IA BORDER. AT THE SURFACE...LOW PRESSURE WAS CENTERED OVER SOUTHWEST WI WITH A COLD FRONT/DRYLINE EXTENDING FROM CENTRAL INTO SOUTHWEST WI. STRONGER CONVECTION WAS FIRING AHEAD OF THE DRYLINE OVER EASTERN WI IN AN AXIS OF HIGHER DEWPOINT/INSTABILITY AXIS AND 25-35KT 0-3KM BULK SHEAR. MEANWHILE...RADAR MOSAIC WAS ALSO SHOWING WEAKER SHOWER/THUNDERSTORM ACTIVITY ENTERING THE FORECAST AREA FROM MN ON THE EASTERN PERIPHERY OF STEEPER LOW-MID-LEVEL LAPSE RATES UNDER THE FILLING CLOSED LOW. RAP ANALYSIS SHOWING THIS AREA IN A ZONE OF VERY WEAK BULK SHEAR...SO JUST EXPECTING MOSTLY SHOWER ACTIVITY WITH ISOLATED THUNDER OUT OF THIS ACTIVITY. LOOK FOR THIS CONVECTION TO CONTINUE MOVING INTO THE AREA THROUGH THE REMAINDER OF THIS AFTERNOON AND INTO TONIGHT AS THE MID-LEVEL TROUGH AXIS MOVES EAST ACROSS THE REGION. LOOK FOR THE SHOWERS TO DIMINISH AND SKIES TO CLEAR FROM WEST TO EAST AFTER MIDNIGHT AS SUBSIDENCE/DRYING TAKES PLACE BEHIND THE DEPARTING TROUGH. A RIDGE OF HIGH PRESSURE WILL THEN BUILD INTO THE AREA ON SUNDAY FOR A DRY/MOSTLY SUNNY DAY. DESPITE MOSTLY SUNNY SKIES...COLD AIR ADVECTION ON NORTHWEST WINDS OF 10-20 MPH WILL YIELD HIGH TEMPERATURES SOME 10 DEGREES BELOW NORMAL IN THE LOW/MID 60S. HIGH PRESSURE WILL BE SITUATED OVERHEAD FOR A CLEAR/COOL/CALM SUNDAY NIGHT. LOOK FOR LOWS RANGING FROM AROUND 40 DEGREES FOR AREAS ALONG/NORTHEAST OF I-94...TO THE MID/UPPER 40S ELSEWHERE. GIVEN THE NEARLY SATURATED GROUND AND THE FACT THE HIGH IS OVERHEAD FOR CALM WINDS...WAS THINKING SOME FOG WOULD BE POSSIBLE. HOWEVER...BUFKIT SOUNDINGS SHOWING THAT THERE WILL BE PLENTY OF DRYING DURING THE DAYTIME SUNDAY AND THEN MAINTAIN AT LEAST A 3-5 DEGREE SPREAD THROUGH THE OVERNIGHT HOURS. WILL THEREFORE LEAVE FOG MENTION OUT...BUT MAY BE SOMETHING TO KEEP AN EYE ON. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 218 PM CDT SAT JUN 1 2013 LOOK FOR HIGH PRESSURE TO REMAIN IN CONTROL ACROSS THE AREA THROUGH MONDAY FOR A CONTINUED DRY BREAK FROM THE SOGGY CONDITIONS OF LATE. LATEST GFS/ECMWF IN FAIRLY GOOD AGREEMENT IN BRINGING A COUPLE WEAK MID-LEVEL TROUGHS ACROSS THE NORTHERN PLAINS INTO OUR REGION TUESDAY THROUGH SATURDAY. VERY LITTLE CAPE/INSTABILITY IS INDICATED BY THE MODELS WHICH WOULD LEAD TO MAINLY SHOWER CHANCES WITH PERHAPS AN ISOLATED THUNDERSTORM OR TWO. APPEARS THIS PERIOD WILL ALSO CONTINUE TO BE MARKED BY COOLER THAN NORMAL TEMPERATURE WITH HIGHS GENERALLY IN THE 60S TO LOWER 70S AND OVERNIGHT LOWS IN THE 50S. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 633 PM CDT SAT JUN 1 2013 A SECONDARY COLD FRONT WAS CURRENTLY IN THE PROCESS OF MOVING INTO AND THROUGH THE TAF SITES AS OF 00Z TAF ISSUANCE. THIS FRONT SHOULD BE COMPLETELY THROUGH BY 02Z...WITH WINDS SWITCHING TO THE NORTHWEST AND INCREASING TO 15 KT WITH GUSTS UP TO 25 KT. THE GUSTS SHOULD DIMINISH IN A FEW HOURS THEREAFTER WITH NIGHTTIME COOLING. A BAND OF SHOWERS HAS BEEN ACCOMPANYING THE FRONTAL PASSAGE...BUT VISIBILITIES HAVE BEEN MAINLY VFR. THESE LOOK TO LAST MAYBE AN HOUR OR TWO AT THE TAF SITES. MVFR STRATUS IS FOLLOWING IN THE WAKE OF THE COLD FRONT...WHICH EXTENDS BACK INTO CENTRAL MINNESOTA. EXPECT THE MVFR STRATUS TO MOVE INTO THE TAF SITES FOR TONIGHT...WITH CONDITIONS IMPROVING TO VFR BY LATE SUNDAY MORNING AS DAYTIME MIXING AND DRIER AIR FROM CANADA HELP SCATTER OUT THE CLOUDS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1248 PM CDT FRI MAY 31 2013 .UPDATE... ISSUED AT 1114 AM CDT FRI MAY 31 2013 THE MAIN FOCUS THROUGH TONIGHT IS ON THE CONVECTIVE POTENTIAL ACROSS THE REGION. CURRENT SURFACE ANALYSIS SHOWS AN UNCAPPED ENVIRONMENT JUST OUT AHEAD OF A DRY LINE THAT RUNS FROM JUST EAST OF THE TWIN CITIES ALONG THE INTERSTATE 35 CORRIDOR THROUGH MINNESOTA AND IOWA. MODIFIED 31.14Z RAP SOUNDINGS SHOW AN UNCAPPED FAT CAPE PROFILE BY EARLY AFTERNOON WITH OVER 2000 J/KG OF SURFACE BASED CAPE DEVELOPING. DEEP SHEAR LOOKS FAVORABLE WITH THE 31.14Z RAP SHOWING A 50-65KT 500MB JET STREAK EXTENDING FROM THE SOUTHERN PLAINS NORTHEAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION. WITH THIS MID LEVEL JET STREAK NOT SHIFTING EAST MUCH THROUGH TONIGHT...0-6KM SHEAR REMAINS HIGH AT AROUND 60KTS THROUGH THIS AFTERNOON AND EVENING. DIRECTIONALLY...THE SHEAR IS MAINLY UNIDIRECTIONAL OUT OF THE SOUTHWEST FROM THE LOW LEVELS UP...BUT THERE IS ENOUGH OF A SOUTHERLY COMPONENT TO THE SURFACE WINDS THAT 0-1KM SHEAR STAYS UP AS WELL. GIVEN ALL THIS...THE CURRENT EXPECTATION WITH STORM MODE IS THAT WITH THE HIGH CAPE/SHEAR ENVIRONMENT IS THAT STORMS WILL RAPIDLY DEVELOP AHEAD OF THE DRY LINE THROUGH THIS AFTERNOON WITH LARGE HAIL BEING THE MAIN THREAT TO START WITH A FEW SUPERCELLS POSSIBLE. CAN NOT RULE OUT A TORNADO DEVELOPING DURING THIS PHASE AS WELL...PARTICULARLY WHERE SURFACE WINDS STAY MORE OUT OF THE SOUTH-SOUTHEAST. WITH TIME...THE ISOLATED/SCATTERED CELLS SHOULD CONVERGE INTO A SQUALL LINE THIS EVENING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT FRI MAY 31 2013 TWO AREAS OF CONVECTION THIS MORNING THAT MAY IMPACT THE AREA. THE FIRST IS PRIMARILY ALREADY OFF THE NORTHWEST OF THE AREA FROM NORTHWEST MINNESOTA INTO WESTERN WISCONSIN. THIS AREA IS MOVING OFF TO THE NORTH/NORTHEAST AND IS NOT EXPECTED TO IMPACT THE FORECAST AREA. THE OTHER AREA OF CONVECTION IS OVER NORTHWEST MISSOURI AND IS MOVING TO THE NORTHEAST. THE HRRR SEEMS TO BE HANDLING THIS THE BEST...BUT IS CONSIDERABLY TOO SLOW WITH IT. THE TREND FROM THE 31.04Z AND 31.05Z RUNS IS FOR THIS AREA TO MOVE NORTHEAST ACROSS EASTERN IOWA INTO NORTHERN ILLINOIS AND FOR THE MOST PART MISSING THE AREA TO THE SOUTH. THE 31.00Z ECMWF ALSO SHOWS THIS AREA COMING OUT OF MISSOURI BUT TAKES IT FARTHER TO THE NORTHWEST IMPACTING THE SOUTHERN AND EASTERN AREAS FROM LATE MORNING THROUGH THE AFTERNOON. THE PREVIOUS FORECAST WAS TRENDED TOWARD THE POSSIBILITY OF THIS CONVECTION COMING INTO THE AREA SO HAVE MAINTAINED THESE TRENDS BUT LIMITED THE HIGHER RAIN CHANCES TO THE SOUTHEAST SECTIONS OF THE FORECAST AREA. BY LATE IN THE AFTERNOON AND INTO THE EVENING...ALL THE MODELS ARE SHOWING WHAT LOOKS LIKE A DRY LINE/WIND SHIFT DEVELOPING AHEAD OF THE SURFACE LOW AND MOVING EAST TOWARD THE AREA. THERE SHOULD BE ANOTHER SHORT WAVE TROUGH ROUNDING THE UPPER LEVEL LOW TO PROVIDE DYNAMIC LIFT OVER THIS DRY LINE/WIND SHIFT. BOTH THE 31.00Z NAM AND GFS SHOW A JET CORE ALSO COMING AROUND THE UPPER LEVEL LOW WITH THE LEFT EXIT REGION COMING OVER THE AREA TO ADD SOME AGEOSTROPHIC MOTIONS TO THE FORCING FROM THE SHORT WAVE TROUGH. THIS SHOULD BE ENOUGH FORCING TO CAUSE A LINE OF CONVECTION TO DEVELOP ALONG THIS DRY LINE AND THEN WORK RAPIDLY EAST ACROSS THE AREA DURING THE EVENING. SOME POTENTIAL FOR SEVERE TODAY...BUT THIS IS DEFINITELY NOT AS HIGH AS THE PAST COUPLE OF DAYS. ML CAPES OF 1000 TO POSSIBLY AS MUCH AS 2000 J/KG SHOULD DEVELOP TODAY AHEAD OF THE DRY LINE. THE BEST 0-6KM SHEAR WILL BE WELL OUT AHEAD OF THE DRY LINE AND WILL LINE UP BETTER WITH THE EXPECTED CONVECTION TO COME NORTHEAST OUT OF MISSOURI. HOWEVER...THE 0-3 KM SHEAR SHOULD BE AROUND 30 KNOTS AHEAD OF THE DRY LINE SO THE POTENTIAL FOR STORMS THIS AFTERNOON AND EVENING TO PRODUCE DAMAGING WINDS AND HAIL. ALL THE ACTIVITY SHOULD QUICKLY DIE DOWN AFTER MIDNIGHT AS IT MOVES OFF TO THE EAST OF THE AREA. BOTH THE NAM AND GFS SHOW THE PRECIPITABLE WATERS LOWERING DURING THE DAY AS DRIER AIR WRAPS IN FROM THE WEST. WHILE ANY THUNDERSTORMS MAY PRODUCE SOME LOCALLY HEAVY RAIN...FEEL THAT THE POTENTIAL FOR WIDESPREAD HEAVY RAINS TO PRODUCE FLASH FLOODING IS NOT THERE TO SUPPORT THE NEED FOR ANOTHER FLASH FLOOD WATCH. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 AM CDT FRI MAY 31 2013 AT LONG LAST...THIS STUBBORN SYSTEM WILL BEGIN TO MAKE A MOVE TO THE EAST SATURDAY. AS IT DOES...THE SURFACE LOW WILL MOVE FROM CENTRAL MINNESOTA INTO NORTHERN WISCONSIN AS THE UPPER LEVEL LOW BECOMES AN OPEN WAVE. THE LAST SHORT WAVE TROUGH WITH THIS SYSTEM IS EXPECTED TO BE MOVING ACROSS THE AREA AND BE PRODUCING AROUND 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER. THIS FORCING FROM THE WAVE COMBINED WITH BEING IN THE DEFORMATION AREA OF THE SURFACE LOW SHOULD BE ENOUGH TO GENERATE SHOWERS ACROSS MUCH OF THE AREA. MU CAPES SHOULD BE AROUND 200-300 J/KG IN THE AFTERNOON WHICH WILL BE GOOD ENOUGH TO PRODUCE SOME ISOLATED THUNDER. THE REMAINING SHOWERS SHOULD THEN MOVE OFF TO THE EAST SATURDAY NIGHT WITH SUNDAY BEING THE FIRST DAY IN ABOUT A WEEK WITH NO CHANCE OF RAIN. MONDAY ALSO LOOKS TO BE DRY WITH HIGH PRESSURE OVER THE AREA BUT THEN THE RAIN CHANCES START TO RETURN FOR MONDAY NIGHT. THE 31.00Z GFS...GEM AND ECMWF ALL SHOW ANOTHER CLOSED LOW MOVING TOWARD THE AREA FROM THE PACIFIC NORTHWEST. PLENTY OF DIFFERENCES THOUGH ON HOW FAST THIS SYSTEM WILL START TO IMPACT THE AREA. THE OPERATIONAL GFS IS THE FASTEST BRINGING THIS SYSTEM IN...EVEN FASTER THAN ITS ENSEMBLE MEAN WHILE THE ECMWF IS THE SLOWEST. THIS LOOKS TO BE ANOTHER SLOW MOVING SYSTEM KEEPING RAIN CHANCES IN THE FORECAST FOR THE REMAINDER OF THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1248 PM CDT FRI MAY 31 2013 THE MAIN FOCUS AT THE TAF SITES IS WITH THE TIMING ON WHEN ANY SHOWERS OR THUNDERSTORMS WILL GET INTO THE TAF SITES. SHOWERS HAVE ALREADY DEVELOPED NEAR RST AND WILL DRIFT TO THE EAST THROUGH THE AFTERNOON. WITH AN UNSTABLE ENVIRONMENT IN PLACE...THESE SHOWERS WILL QUICKLY STRENGTHEN EARLY THIS AFTERNOON WITH THUNDERSTORMS LIKELY AT RST BETWEEN 19Z/23Z. AS THE STORMS MARCH EAST...THEY SHOULD REACH LSE SOMETIME BETWEEN 23Z AND 02Z. MVFR CUMULUS FIELD WILL LIKELY STAY IN PLACE OR GRADUALLY CLIMB THIS AFTERNOON BEFORE MVFR/IFR CONDITIONS COME IN WITH THE THUNDERSTORMS. CONDITIONS SHOULD CLEAR OUT LATER THIS EVENING WITH WINDS SUBSIDING OVERNIGHT. && .HYDROLOGY... ISSUED AT 329 AM CDT FRI MAY 31 2013 TURKEY RIVER... WITH THURSDAY BEING MUCH DRIER THAN EXPECTED IN NORTHEAST IOWA...THE TURKEY RIVER IS COMING IN MUCH LOWER THAN ORIGINALLY ANTICIPATED. ELKADER IS EXPECTED TO CREST AROUND 16.5 FEET. THIS IS ABOUT 2 FEET LOWER THAN THE PREVIOUS FORECAST. THIS IN TURN WILL RESULT IN A MUCH LOWER CREST FOR GARBER. THE RIVER HAS ALREADY CRESTED AROUND 22.1 FEET. IT SHOULD REMAIN AROUND THIS LEVEL THROUGH MUCH OF TODAY AND THEN BEGIN A SLOW FALL. UPPER IOWA... DORCHESTER HAS FLATTENED OUT AROUND 13.4 FEET. WITH DECORAH CONTINUING TO RISE UPSTREAM...EXPECT THAT DORCHESTER WILL ONCE AGAIN START TO RISE THIS MORNING. CONSIDERING THE RAINFALL ACROSS THIS BASIN ON THURSDAY STILL NOT QUITE SURE WHETHER THE CREST LATER THIS AFTERNOON WILL BE ABOUT A HALF FEET /15.5 FEET/ HIGHER THAN ITS PREVIOUS CREST OF 15 FEET ON THURSDAY MORNING. AM MORE INCLINED THAT IT WILL COME IN WITH A SIMILAR AS THURSDAY MORNING. KICKAPOO RIVER... THE UPPER REACHES OF THE KICKAPOO HAVE ALREADY CRESTED AND STARTED TO FALL RAPIDLY...THEREFORE...LA FARGE WILL BE ADJUSTED TO CREST LOWER THAN EXPECTED /STILL BELOW FLOOD STAGE/ BLACK RIVER... BLACK RIVER FALLS IS CONTINUING TO RISE RATHER RAPIDLY THIS MORNING. LOOKING AT THE WATER UPSTREAM...THE NORTH CENTRAL RIVER FORECAST CENTER IS EXPECTING IT TO NOW CREST AROUND 49.3 FEET LATER TODAY. TREMPEALEAU RIVER... DUE TO THE BROADER EXPANSE NEAR DODGE...EXPECT TO SEE A SLOW AND STEADY RISE INTO THE WEEKEND. IT STILL LOOKS LIKE IT WILL CREST ON SUNDAY AROUND 9.6 FEET. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...HALBACH SHORT TERM...04 LONG TERM...04 AVIATION...HALBACH HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1114 AM CDT FRI MAY 31 2013 .UPDATE... ISSUED AT 1114 AM CDT FRI MAY 31 2013 THE MAIN FOCUS THROUGH TONIGHT IS ON THE CONVECTIVE POTENTIAL ACROSS THE REGION. CURRENT SURFACE ANALYSIS SHOWS AN UNCAPPED ENVIRONMENT JUST OUT AHEAD OF A DRY LINE THAT RUNS FROM JUST EAST OF THE TWIN CITIES ALONG THE INTERSTATE 35 CORRIDOR THROUGH MINNESOTA AND IOWA. MODIFIED 31.14Z RAP SOUNDINGS SHOW AN UNCAPPED FAT CAPE PROFILE BY EARLY AFTERNOON WITH OVER 2000 J/KG OF SURFACE BASED CAPE DEVELOPING. DEEP SHEAR LOOKS FAVORABLE WITH THE 31.14Z RAP SHOWING A 50-65KT 500MB JET STREAK EXTENDING FROM THE SOUTHERN PLAINS NORTHEAST THROUGH THE UPPER MISSISSIPPI RIVER VALLEY REGION. WITH THIS MID LEVEL JET STREAK NOT SHIFTING EAST MUCH THROUGH TONIGHT...0-6KM SHEAR REMAINS HIGH AT AROUND 60KTS THROUGH THIS AFTERNOON AND EVENING. DIRECTIONALLY...THE SHEAR IS MAINLY UNIDIRECTIONAL OUT OF THE SOUTHWEST FROM THE LOW LEVELS UP...BUT THERE IS ENOUGH OF A SOUTHERLY COMPONENT TO THE SURFACE WINDS THAT 0-1KM SHEAR STAYS UP AS WELL. GIVEN ALL THIS...THE CURRENT EXPECTATION WITH STORM MODE IS THAT WITH THE HIGH CAPE/SHEAR ENVIRONMENT IS THAT STORMS WILL RAPIDLY DEVELOP AHEAD OF THE DRY LINE THROUGH THIS AFTERNOON WITH LARGE HAIL BEING THE MAIN THREAT TO START WITH A FEW SUPERCELLS POSSIBLE. CAN NOT RULE OUT A TORNADO DEVELOPING DURING THIS PHASE AS WELL...PARTICULARLY WHERE SURFACE WINDS STAY MORE OUT OF THE SOUTH-SOUTHEAST. WITH TIME...THE ISOLATED/SCATTERED CELLS SHOULD CONVERGE INTO A SQUALL LINE THIS EVENING. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT FRI MAY 31 2013 TWO AREAS OF CONVECTION THIS MORNING THAT MAY IMPACT THE AREA. THE FIRST IS PRIMARILY ALREADY OFF THE NORTHWEST OF THE AREA FROM NORTHWEST MINNESOTA INTO WESTERN WISCONSIN. THIS AREA IS MOVING OFF TO THE NORTH/NORTHEAST AND IS NOT EXPECTED TO IMPACT THE FORECAST AREA. THE OTHER AREA OF CONVECTION IS OVER NORTHWEST MISSOURI AND IS MOVING TO THE NORTHEAST. THE HRRR SEEMS TO BE HANDLING THIS THE BEST...BUT IS CONSIDERABLY TOO SLOW WITH IT. THE TREND FROM THE 31.04Z AND 31.05Z RUNS IS FOR THIS AREA TO MOVE NORTHEAST ACROSS EASTERN IOWA INTO NORTHERN ILLINOIS AND FOR THE MOST PART MISSING THE AREA TO THE SOUTH. THE 31.00Z ECMWF ALSO SHOWS THIS AREA COMING OUT OF MISSOURI BUT TAKES IT FARTHER TO THE NORTHWEST IMPACTING THE SOUTHERN AND EASTERN AREAS FROM LATE MORNING THROUGH THE AFTERNOON. THE PREVIOUS FORECAST WAS TRENDED TOWARD THE POSSIBILITY OF THIS CONVECTION COMING INTO THE AREA SO HAVE MAINTAINED THESE TRENDS BUT LIMITED THE HIGHER RAIN CHANCES TO THE SOUTHEAST SECTIONS OF THE FORECAST AREA. BY LATE IN THE AFTERNOON AND INTO THE EVENING...ALL THE MODELS ARE SHOWING WHAT LOOKS LIKE A DRY LINE/WIND SHIFT DEVELOPING AHEAD OF THE SURFACE LOW AND MOVING EAST TOWARD THE AREA. THERE SHOULD BE ANOTHER SHORT WAVE TROUGH ROUNDING THE UPPER LEVEL LOW TO PROVIDE DYNAMIC LIFT OVER THIS DRY LINE/WIND SHIFT. BOTH THE 31.00Z NAM AND GFS SHOW A JET CORE ALSO COMING AROUND THE UPPER LEVEL LOW WITH THE LEFT EXIT REGION COMING OVER THE AREA TO ADD SOME AGEOSTROPHIC MOTIONS TO THE FORCING FROM THE SHORT WAVE TROUGH. THIS SHOULD BE ENOUGH FORCING TO CAUSE A LINE OF CONVECTION TO DEVELOP ALONG THIS DRY LINE AND THEN WORK RAPIDLY EAST ACROSS THE AREA DURING THE EVENING. SOME POTENTIAL FOR SEVERE TODAY...BUT THIS IS DEFINITELY NOT AS HIGH AS THE PAST COUPLE OF DAYS. ML CAPES OF 1000 TO POSSIBLY AS MUCH AS 2000 J/KG SHOULD DEVELOP TODAY AHEAD OF THE DRY LINE. THE BEST 0-6KM SHEAR WILL BE WELL OUT AHEAD OF THE DRY LINE AND WILL LINE UP BETTER WITH THE EXPECTED CONVECTION TO COME NORTHEAST OUT OF MISSOURI. HOWEVER...THE 0-3 KM SHEAR SHOULD BE AROUND 30 KNOTS AHEAD OF THE DRY LINE SO THE POTENTIAL FOR STORMS THIS AFTERNOON AND EVENING TO PRODUCE DAMAGING WINDS AND HAIL. ALL THE ACTIVITY SHOULD QUICKLY DIE DOWN AFTER MIDNIGHT AS IT MOVES OFF TO THE EAST OF THE AREA. BOTH THE NAM AND GFS SHOW THE PRECIPITABLE WATERS LOWERING DURING THE DAY AS DRIER AIR WRAPS IN FROM THE WEST. WHILE ANY THUNDERSTORMS MAY PRODUCE SOME LOCALLY HEAVY RAIN...FEEL THAT THE POTENTIAL FOR WIDESPREAD HEAVY RAINS TO PRODUCE FLASH FLOODING IS NOT THERE TO SUPPORT THE NEED FOR ANOTHER FLASH FLOOD WATCH. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 AM CDT FRI MAY 31 2013 AT LONG LAST...THIS STUBBORN SYSTEM WILL BEGIN TO MAKE A MOVE TO THE EAST SATURDAY. AS IT DOES...THE SURFACE LOW WILL MOVE FROM CENTRAL MINNESOTA INTO NORTHERN WISCONSIN AS THE UPPER LEVEL LOW BECOMES AN OPEN WAVE. THE LAST SHORT WAVE TROUGH WITH THIS SYSTEM IS EXPECTED TO BE MOVING ACROSS THE AREA AND BE PRODUCING AROUND 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER. THIS FORCING FROM THE WAVE COMBINED WITH BEING IN THE DEFORMATION AREA OF THE SURFACE LOW SHOULD BE ENOUGH TO GENERATE SHOWERS ACROSS MUCH OF THE AREA. MU CAPES SHOULD BE AROUND 200-300 J/KG IN THE AFTERNOON WHICH WILL BE GOOD ENOUGH TO PRODUCE SOME ISOLATED THUNDER. THE REMAINING SHOWERS SHOULD THEN MOVE OFF TO THE EAST SATURDAY NIGHT WITH SUNDAY BEING THE FIRST DAY IN ABOUT A WEEK WITH NO CHANCE OF RAIN. MONDAY ALSO LOOKS TO BE DRY WITH HIGH PRESSURE OVER THE AREA BUT THEN THE RAIN CHANCES START TO RETURN FOR MONDAY NIGHT. THE 31.00Z GFS...GEM AND ECMWF ALL SHOW ANOTHER CLOSED LOW MOVING TOWARD THE AREA FROM THE PACIFIC NORTHWEST. PLENTY OF DIFFERENCES THOUGH ON HOW FAST THIS SYSTEM WILL START TO IMPACT THE AREA. THE OPERATIONAL GFS IS THE FASTEST BRINGING THIS SYSTEM IN...EVEN FASTER THAN ITS ENSEMBLE MEAN WHILE THE ECMWF IS THE SLOWEST. THIS LOOKS TO BE ANOTHER SLOW MOVING SYSTEM KEEPING RAIN CHANCES IN THE FORECAST FOR THE REMAINDER OF THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 700 AM CDT FRI MAY 31 2013 IFR TO MVFR CEILINGS WILL GRADUALLY BECOME VFR BY 31.15Z. SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF A COLD FRONT LATE THIS AFTERNOON AND EVENING. THESE THUNDERSTORMS WILL AFFECT KRST BETWEEN 31.22Z AND 01.04Z...AND KLSE BETWEEN 01.00Z AND 01.06Z. A FEW OF THESE THUNDERSTORMS MAY BECOME SEVERE. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. THERE MAY BE EVEN AN ISOLATED TORNADO. ONCE THE FRONT CLEARS THE AREA CEILINGS WILL CLIMB TO AROUND 10K FEET. && .HYDROLOGY... ISSUED AT 329 AM CDT FRI MAY 31 2013 TURKEY RIVER... WITH THURSDAY BEING MUCH DRIER THAN EXPECTED IN NORTHEAST IOWA...THE TURKEY RIVER IS COMING IN MUCH LOWER THAN ORIGINALLY ANTICIPATED. ELKADER IS EXPECTED TO CREST AROUND 16.5 FEET. THIS IS ABOUT 2 FEET LOWER THAN THE PREVIOUS FORECAST. THIS IN TURN WILL RESULT IN A MUCH LOWER CREST FOR GARBER. THE RIVER HAS ALREADY CRESTED AROUND 22.1 FEET. IT SHOULD REMAIN AROUND THIS LEVEL THROUGH MUCH OF TODAY AND THEN BEGIN A SLOW FALL. UPPER IOWA... DORCHESTER HAS FLATTENED OUT AROUND 13.4 FEET. WITH DECORAH CONTINUING TO RISE UPSTREAM...EXPECT THAT DORCHESTER WILL ONCE AGAIN START TO RISE THIS MORNING. CONSIDERING THE RAINFALL ACROSS THIS BASIN ON THURSDAY STILL NOT QUITE SURE WHETHER THE CREST LATER THIS AFTERNOON WILL BE ABOUT A HALF FEET /15.5 FEET/ HIGHER THAN ITS PREVIOUS CREST OF 15 FEET ON THURSDAY MORNING. AM MORE INCLINED THAT IT WILL COME IN WITH A SIMILAR AS THURSDAY MORNING. KICKAPOO RIVER... THE UPPER REACHES OF THE KICKAPOO HAVE ALREADY CRESTED AND STARTED TO FALL RAPIDLY...THEREFORE...LA FARGE WILL BE ADJUSTED TO CREST LOWER THAN EXPECTED /STILL BELOW FLOOD STAGE/ BLACK RIVER... BLACK RIVER FALLS IS CONTINUING TO RISE RATHER RAPIDLY THIS MORNING. LOOKING AT THE WATER UPSTREAM...THE NORTH CENTRAL RIVER FORECAST CENTER IS EXPECTING IT TO NOW CREST AROUND 49.3 FEET LATER TODAY. TREMPEALEAU RIVER... DUE TO THE BROADER EXPANSE NEAR DODGE...EXPECT TO SEE A SLOW AND STEADY RISE INTO THE WEEKEND. IT STILL LOOKS LIKE IT WILL CREST ON SUNDAY AROUND 9.6 FEET. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...HALBACH SHORT TERM...04 LONG TERM...04 AVIATION...BOYNE HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
703 AM CDT FRI MAY 31 2013 .UPDATE...THIS MORNING ISSUED AT 700 AM CDT FRI MAY 31 2013 EARLY THIS MORNING...SHOWERS WILL CONTINUE TO BE FOUND IN WISCONSIN NORTH OF THE INTERSTATE 90 CORRIDOR. THESE SHOWERS ARE DEVELOPING ON NOSE OF THE DRY SLOT...AND SHOULD BE NORTHEAST OF THE AREA BY 31.15Z. FOR MID TO LATE MORNING...THE MAIN CONCERN IS WHERE THE MESOSCALE CONVECTIVE COMPLEX OVER MISSOURI WILL TRACK THIS MORNING. THE LATEST RAP CONTINUES TO BRING THIS SYSTEM NORTHEAST INTO THE AREA. MEANWHILE THE HRRR SHOWS THAT THIS SYSTEM WILL REMAIN SOUTH OF THE AREA. LOOKING AT THE MEAN WIND VECTORS OFF OF THE RADAR...THE HRRR MAKES MUCH MORE SENSE...SO TRENDED THE FORECAST THAT WAY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT FRI MAY 31 2013 TWO AREAS OF CONVECTION THIS MORNING THAT MAY IMPACT THE AREA. THE FIRST IS PRIMARILY ALREADY OFF THE NORTHWEST OF THE AREA FROM NORTHWEST MINNESOTA INTO WESTERN WISCONSIN. THIS AREA IS MOVING OFF TO THE NORTH/NORTHEAST AND IS NOT EXPECTED TO IMPACT THE FORECAST AREA. THE OTHER AREA OF CONVECTION IS OVER NORTHWEST MISSOURI AND IS MOVING TO THE NORTHEAST. THE HRRR SEEMS TO BE HANDLING THIS THE BEST...BUT IS CONSIDERABLY TOO SLOW WITH IT. THE TREND FROM THE 31.04Z AND 31.05Z RUNS IS FOR THIS AREA TO MOVE NORTHEAST ACROSS EASTERN IOWA INTO NORTHERN ILLINOIS AND FOR THE MOST PART MISSING THE AREA TO THE SOUTH. THE 31.00Z ECMWF ALSO SHOWS THIS AREA COMING OUT OF MISSOURI BUT TAKES IT FARTHER TO THE NORTHWEST IMPACTING THE SOUTHERN AND EASTERN AREAS FROM LATE MORNING THROUGH THE AFTERNOON. THE PREVIOUS FORECAST WAS TRENDED TOWARD THE POSSIBILITY OF THIS CONVECTION COMING INTO THE AREA SO HAVE MAINTAINED THESE TRENDS BUT LIMITED THE HIGHER RAIN CHANCES TO THE SOUTHEAST SECTIONS OF THE FORECAST AREA. BY LATE IN THE AFTERNOON AND INTO THE EVENING...ALL THE MODELS ARE SHOWING WHAT LOOKS LIKE A DRY LINE/WIND SHIFT DEVELOPING AHEAD OF THE SURFACE LOW AND MOVING EAST TOWARD THE AREA. THERE SHOULD BE ANOTHER SHORT WAVE TROUGH ROUNDING THE UPPER LEVEL LOW TO PROVIDE DYNAMIC LIFT OVER THIS DRY LINE/WIND SHIFT. BOTH THE 31.00Z NAM AND GFS SHOW A JET CORE ALSO COMING AROUND THE UPPER LEVEL LOW WITH THE LEFT EXIT REGION COMING OVER THE AREA TO ADD SOME AGEOSTROPHIC MOTIONS TO THE FORCING FROM THE SHORT WAVE TROUGH. THIS SHOULD BE ENOUGH FORCING TO CAUSE A LINE OF CONVECTION TO DEVELOP ALONG THIS DRY LINE AND THEN WORK RAPIDLY EAST ACROSS THE AREA DURING THE EVENING. SOME POTENTIAL FOR SEVERE TODAY...BUT THIS IS DEFINITELY NOT AS HIGH AS THE PAST COUPLE OF DAYS. ML CAPES OF 1000 TO POSSIBLY AS MUCH AS 2000 J/KG SHOULD DEVELOP TODAY AHEAD OF THE DRY LINE. THE BEST 0-6KM SHEAR WILL BE WELL OUT AHEAD OF THE DRY LINE AND WILL LINE UP BETTER WITH THE EXPECTED CONVECTION TO COME NORTHEAST OUT OF MISSOURI. HOWEVER...THE 0-3 KM SHEAR SHOULD BE AROUND 30 KNOTS AHEAD OF THE DRY LINE SO THE POTENTIAL FOR STORMS THIS AFTERNOON AND EVENING TO PRODUCE DAMAGING WINDS AND HAIL. ALL THE ACTIVITY SHOULD QUICKLY DIE DOWN AFTER MIDNIGHT AS IT MOVES OFF TO THE EAST OF THE AREA. BOTH THE NAM AND GFS SHOW THE PRECIPITABLE WATERS LOWERING DURING THE DAY AS DRIER AIR WRAPS IN FROM THE WEST. WHILE ANY THUNDERSTORMS MAY PRODUCE SOME LOCALLY HEAVY RAIN...FEEL THAT THE POTENTIAL FOR WIDESPREAD HEAVY RAINS TO PRODUCE FLASH FLOODING IS NOT THERE TO SUPPORT THE NEED FOR ANOTHER FLASH FLOOD WATCH. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 AM CDT FRI MAY 31 2013 AT LONG LAST...THIS STUBBORN SYSTEM WILL BEGIN TO MAKE A MOVE TO THE EAST SATURDAY. AS IT DOES...THE SURFACE LOW WILL MOVE FROM CENTRAL MINNESOTA INTO NORTHERN WISCONSIN AS THE UPPER LEVEL LOW BECOMES AN OPEN WAVE. THE LAST SHORT WAVE TROUGH WITH THIS SYSTEM IS EXPECTED TO BE MOVING ACROSS THE AREA AND BE PRODUCING AROUND 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER. THIS FORCING FROM THE WAVE COMBINED WITH BEING IN THE DEFORMATION AREA OF THE SURFACE LOW SHOULD BE ENOUGH TO GENERATE SHOWERS ACROSS MUCH OF THE AREA. MU CAPES SHOULD BE AROUND 200-300 J/KG IN THE AFTERNOON WHICH WILL BE GOOD ENOUGH TO PRODUCE SOME ISOLATED THUNDER. THE REMAINING SHOWERS SHOULD THEN MOVE OFF TO THE EAST SATURDAY NIGHT WITH SUNDAY BEING THE FIRST DAY IN ABOUT A WEEK WITH NO CHANCE OF RAIN. MONDAY ALSO LOOKS TO BE DRY WITH HIGH PRESSURE OVER THE AREA BUT THEN THE RAIN CHANCES START TO RETURN FOR MONDAY NIGHT. THE 31.00Z GFS...GEM AND ECMWF ALL SHOW ANOTHER CLOSED LOW MOVING TOWARD THE AREA FROM THE PACIFIC NORTHWEST. PLENTY OF DIFFERENCES THOUGH ON HOW FAST THIS SYSTEM WILL START TO IMPACT THE AREA. THE OPERATIONAL GFS IS THE FASTEST BRINGING THIS SYSTEM IN...EVEN FASTER THAN ITS ENSEMBLE MEAN WHILE THE ECMWF IS THE SLOWEST. THIS LOOKS TO BE ANOTHER SLOW MOVING SYSTEM KEEPING RAIN CHANCES IN THE FORECAST FOR THE REMAINDER OF THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 700 AM CDT FRI MAY 31 2013 IFR TO MVFR CEILINGS WILL GRADUALLY BECOME VFR BY 31.15Z. SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF A COLD FRONT LATE THIS AFTERNOON AND EVENING. THESE THUNDERSTORMS WILL AFFECT KRST BETWEEN 31.22Z AND 01.04Z...AND KLSE BETWEEN 01.00Z AND 01.06Z. A FEW OF THESE THUNDERSTORMS MAY BECOME SEVERE. THE MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WINDS. THERE MAY BE EVEN AN ISOLATED TORNADO. ONCE THE FRONT CLEARS THE AREA CEILINGS WILL CLIMB TO AROUND 10K FEET. && .HYDROLOGY... ISSUED AT 329 AM CDT FRI MAY 31 2013 TURKEY RIVER... WITH THURSDAY BEING MUCH DRIER THAN EXPECTED IN NORTHEAST IOWA...THE TURKEY RIVER IS COMING IN MUCH LOWER THAN ORIGINALLY ANTICIPATED. ELKADER IS EXPECTED TO CREST AROUND 16.5 FEET. THIS IS ABOUT 2 FEET LOWER THAN THE PREVIOUS FORECAST. THIS IN TURN WILL RESULT IN A MUCH LOWER CREST FOR GARBER. THE RIVER HAS ALREADY CRESTED AROUND 22.1 FEET. IT SHOULD REMAIN AROUND THIS LEVEL THROUGH MUCH OF TODAY AND THEN BEGIN A SLOW FALL. UPPER IOWA... DORCHESTER HAS FLATTENED OUT AROUND 13.4 FEET. WITH DECORAH CONTINUING TO RISE UPSTREAM...EXPECT THAT DORCHESTER WILL ONCE AGAIN START TO RISE THIS MORNING. CONSIDERING THE RAINFALL ACROSS THIS BASIN ON THURSDAY STILL NOT QUITE SURE WHETHER THE CREST LATER THIS AFTERNOON WILL BE ABOUT A HALF FEET /15.5 FEET/ HIGHER THAN ITS PREVIOUS CREST OF 15 FEET ON THURSDAY MORNING. AM MORE INCLINED THAT IT WILL COME IN WITH A SIMILAR AS THURSDAY MORNING. KICKAPOO RIVER... THE UPPER REACHES OF THE KICKAPOO HAVE ALREADY CRESTED AND STARTED TO FALL RAPIDLY...THEREFORE...LA FARGE WILL BE ADJUSTED TO CREST LOWER THAN EXPECTED /STILL BELOW FLOOD STAGE/ BLACK RIVER... BLACK RIVER FALLS IS CONTINUING TO RISE RATHER RAPIDLY THIS MORNING. LOOKING AT THE WATER UPSTREAM...THE NORTH CENTRAL RIVER FORECAST CENTER IS EXPECTING IT TO NOW CREST AROUND 49.3 FEET LATER TODAY. TREMPEALEAU RIVER... DUE TO THE BROADER EXPANSE NEAR DODGE...EXPECT TO SEE A SLOW AND STEADY RISE INTO THE WEEKEND. IT STILL LOOKS LIKE IT WILL CREST ON SUNDAY AROUND 9.6 FEET. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...BOYNE SHORT TERM...04 LONG TERM...04 AVIATION...BOYNE HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
329 AM CDT FRI MAY 31 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 329 AM CDT FRI MAY 31 2013 TWO AREAS OF CONVECTION THIS MORNING THAT MAY IMPACT THE AREA. THE FIRST IS PRIMARILY ALREADY OFF THE NORTHWEST OF THE AREA FROM NORTHWEST MINNESOTA INTO WESTERN WISCONSIN. THIS AREA IS MOVING OFF TO THE NORTH/NORTHEAST AND IS NOT EXPECTED TO IMPACT THE FORECAST AREA. THE OTHER AREA OF CONVECTION IS OVER NORTHWEST MISSOURI AND IS MOVING TO THE NORTHEAST. THE HRRR SEEMS TO BE HANDLING THIS THE BEST...BUT IS CONSIDERABLY TOO SLOW WITH IT. THE TREND FROM THE 31.04Z AND 31.05Z RUNS IS FOR THIS AREA TO MOVE NORTHEAST ACROSS EASTERN IOWA INTO NORTHERN ILLINOIS AND FOR THE MOST PART MISSING THE AREA TO THE SOUTH. THE 31.00Z ECMWF ALSO SHOWS THIS AREA COMING OUT OF MISSOURI BUT TAKES IT FARTHER TO THE NORTHWEST IMPACTING THE SOUTHERN AND EASTERN AREAS FROM LATE MORNING THROUGH THE AFTERNOON. THE PREVIOUS FORECAST WAS TRENDED TOWARD THE POSSIBILITY OF THIS CONVECTION COMING INTO THE AREA SO HAVE MAINTAINED THESE TRENDS BUT LIMITED THE HIGHER RAIN CHANCES TO THE SOUTHEAST SECTIONS OF THE FORECAST AREA. BY LATE IN THE AFTERNOON AND INTO THE EVENING...ALL THE MODELS ARE SHOWING WHAT LOOKS LIKE A DRY LINE/WIND SHIFT DEVELOPING AHEAD OF THE SURFACE LOW AND MOVING EAST TOWARD THE AREA. THERE SHOULD BE ANOTHER SHORT WAVE TROUGH ROUNDING THE UPPER LEVEL LOW TO PROVIDE DYNAMIC LIFT OVER THIS DRY LINE/WIND SHIFT. BOTH THE 31.00Z NAM AND GFS SHOW A JET CORE ALSO COMING AROUND THE UPPER LEVEL LOW WITH THE LEFT EXIT REGION COMING OVER THE AREA TO ADD SOME AGEOSTROPHIC MOTIONS TO THE FORCING FROM THE SHORT WAVE TROUGH. THIS SHOULD BE ENOUGH FORCING TO CAUSE A LINE OF CONVECTION TO DEVELOP ALONG THIS DRY LINE AND THEN WORK RAPIDLY EAST ACROSS THE AREA DURING THE EVENING. SOME POTENTIAL FOR SEVERE TODAY...BUT THIS IS DEFINITELY NOT AS HIGH AS THE PAST COUPLE OF DAYS. ML CAPES OF 1000 TO POSSIBLY AS MUCH AS 2000 J/KG SHOULD DEVELOP TODAY AHEAD OF THE DRY LINE. THE BEST 0-6KM SHEAR WILL BE WELL OUT AHEAD OF THE DRY LINE AND WILL LINE UP BETTER WITH THE EXPECTED CONVECTION TO COME NORTHEAST OUT OF MISSOURI. HOWEVER...THE 0-3 KM SHEAR SHOULD BE AROUND 30 KNOTS AHEAD OF THE DRY LINE SO THE POTENTIAL FOR STORMS THIS AFTERNOON AND EVENING TO PRODUCE DAMAGING WINDS AND HAIL. ALL THE ACTIVITY SHOULD QUICKLY DIE DOWN AFTER MIDNIGHT AS IT MOVES OFF TO THE EAST OF THE AREA. BOTH THE NAM AND GFS SHOW THE PRECIPITABLE WATERS LOWERING DURING THE DAY AS DRIER AIR WRAPS IN FROM THE WEST. WHILE ANY THUNDERSTORMS MAY PRODUCE SOME LOCALLY HEAVY RAIN...FEEL THAT THE POTENTIAL FOR WIDESPREAD HEAVY RAINS TO PRODUCE FLASH FLOODING IS NOT THERE TO SUPPORT THE NEED FOR ANOTHER FLASH FLOOD WATCH. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 329 AM CDT FRI MAY 31 2013 AT LONG LAST...THIS STUBBORN SYSTEM WILL BEGIN TO MAKE A MOVE TO THE EAST SATURDAY. AS IT DOES...THE SURFACE LOW WILL MOVE FROM CENTRAL MINNESOTA INTO NORTHERN WISCONSIN AS THE UPPER LEVEL LOW BECOMES AN OPEN WAVE. THE LAST SHORT WAVE TROUGH WITH THIS SYSTEM IS EXPECTED TO BE MOVING ACROSS THE AREA AND BE PRODUCING AROUND 8 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER. THIS FORCING FROM THE WAVE COMBINED WITH BEING IN THE DEFORMATION AREA OF THE SURFACE LOW SHOULD BE ENOUGH TO GENERATE SHOWERS ACROSS MUCH OF THE AREA. MU CAPES SHOULD BE AROUND 200-300 J/KG IN THE AFTERNOON WHICH WILL BE GOOD ENOUGH TO PRODUCE SOME ISOLATED THUNDER. THE REMAINING SHOWERS SHOULD THEN MOVE OFF TO THE EAST SATURDAY NIGHT WITH SUNDAY BEING THE FIRST DAY IN ABOUT A WEEK WITH NO CHANCE OF RAIN. MONDAY ALSO LOOKS TO BE DRY WITH HIGH PRESSURE OVER THE AREA BUT THEN THE RAIN CHANCES START TO RETURN FOR MONDAY NIGHT. THE 31.00Z GFS...GEM AND ECMWF ALL SHOW ANOTHER CLOSED LOW MOVING TOWARD THE AREA FROM THE PACIFIC NORTHWEST. PLENTY OF DIFFERENCES THOUGH ON HOW FAST THIS SYSTEM WILL START TO IMPACT THE AREA. THE OPERATIONAL GFS IS THE FASTEST BRINGING THIS SYSTEM IN...EVEN FASTER THAN ITS ENSEMBLE MEAN WHILE THE ECMWF IS THE SLOWEST. THIS LOOKS TO BE ANOTHER SLOW MOVING SYSTEM KEEPING RAIN CHANCES IN THE FORECAST FOR THE REMAINDER OF THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1201 AM CDT FRI MAY 31 2013 RECENT RAINS ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION HAS RESULTED IN SCT-BKN MVFR STRATUS...AFFECTING MOSTLY ALONG THE MISSISSIPPI RIVER. HOWEVER...UNCERTAINTY EXISTS ON HOW LONG THE STRATUS WILL HANG AROUND WITH A BREEZY SOUTHERLY WIND PERSISTING TO HELP KEEP THINGS MIXED. FOR NOW HAVE INCLUDED A TEMPO GROUP UNTIL 09Z FOR THE STRATUS...BUT AMENDMENTS MAY BE REQUIRED IF THE STRATUS HANGS AROUND LONGER. TO THE WEST...A BAND OF SHOWERS AND A FEW THUNDERSTORMS WAS TRACKING ACROSS SOUTHWEST MN AND NORTHWEST IA AS OF MIDNIGHT. THESE ARE ON THE WANE...THOUGH...SO UNCERTAIN DESPITE THERE NORTHEAST MOVEMENT THAT THEY CAN MAKE IT TO KRST BEFORE DISSIPATING. HAVE LEFT THEM OUT OF THE KRST TAF FOR NOW. A BRIEF PERIOD OF MVFR CONDITIONS LOOKS POSSIBLE BETWEEN 15-17Z THIS MORNING...WHEN DAYTIME MIXING TAKES THE RECENT MOISTURE AND HELPS FORM A LOW CUMULUS DECK. CEILINGS SHOULD RISE TO VFR AS MIXING CONTINUES. HEADING INTO THE EVENING...INDICATIONS ARE THAT A DRY-LINE WILL MOVE WEST TO EAST ACROSS THE TAF SITES...BRINGING WITH IT POTENTIAL FOR A LINE OF SHOWERS AND THUNDERSTORMS. TRIED TO TIME THIS BETWEEN 23-04Z. THERE COULD BE SEVERE WEATHER WITH THIS LINE AS WELL...SOMETHING TO WATCH. OTHERWISE...VFR CONDITIONS LOOK TO FOLLOW IN THE WAKE OF THE DRY-LINE AND EVENTUALLY A COLD FRONTAL PASSAGE LATER IN THE EVENING. ONLY OTHER ITEM OF NOTE IS THE WINDS WHICH LOOK TO GET GUSTY THIS AFTERNOON WITH DAYTIME MIXING AHEAD OF THE DRY-LINE/COLD FRONT. GUSTS AGAIN OF 20-25 KT FROM THE SOUTH ARE EXPECTED. && .HYDROLOGY... ISSUED AT 329 AM CDT FRI MAY 31 2013 TURKEY RIVER... WITH THURSDAY BEING MUCH DRIER THAN EXPECTED IN NORTHEAST IOWA...THE TURKEY RIVER IS COMING IN MUCH LOWER THAN ORIGINALLY ANTICIPATED. ELKADER IS EXPECTED TO CREST AROUND 16.5 FEET. THIS IS ABOUT 2 FEET LOWER THAN THE PREVIOUS FORECAST. THIS IN TURN WILL RESULT IN A MUCH LOWER CREST FOR GARBER. THE RIVER HAS ALREADY CRESTED AROUND 22.1 FEET. IT SHOULD REMAIN AROUND THIS LEVEL THROUGH MUCH OF TODAY AND THEN BEGIN A SLOW FALL. UPPER IOWA... DORCHESTER HAS FLATTENED OUT AROUND 13.4 FEET. WITH DECORAH CONTINUING TO RISE UPSTREAM...EXPECT THAT DORCHESTER WILL ONCE AGAIN START TO RISE THIS MORNING. CONSIDERING THE RAINFALL ACROSS THIS BASIN ON THURSDAY STILL NOT QUITE SURE WHETHER THE CREST LATER THIS AFTERNOON WILL BE ABOUT A HALF FEET /15.5 FEET/ HIGHER THAN ITS PREVIOUS CREST OF 15 FEET ON THURSDAY MORNING. AM MORE INCLINED THAT IT WILL COME IN WITH A SIMILAR AS THURSDAY MORNING. KICKAPOO RIVER... THE UPPER REACHES OF THE KICKAPOO HAVE ALREADY CRESTED AND STARTED TO FALL RAPIDLY...THEREFORE...LA FARGE WILL BE ADJUSTED TO CREST LOWER THAN EXPECTED /STILL BELOW FLOOD STAGE/ BLACK RIVER... BLACK RIVER FALLS IS CONTINUING TO RISE RATHER RAPIDLY THIS MORNING. LOOKING AT THE WATER UPSTREAM...THE NORTH CENTRAL RIVER FORECAST CENTER IS EXPECTING IT TO NOW CREST AROUND 49.3 FEET LATER TODAY. TREMPEALEAU RIVER... DUE TO THE BROADER EXPANSE NEAR DODGE...EXPECT TO SEE A SLOW AND STEADY RISE INTO THE WEEKEND. IT STILL LOOKS LIKE IT WILL CREST ON SUNDAY AROUND 9.6 FEET. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...AJ HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
457 AM EDT SUN JUN 2 2013 .SYNOPSIS...WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS WLY FLOW ALOFT AND A NARROW AREA OF DRY AIR ALOFT STILL AFFECTING THE CWA. A LARGE SCALE TROUGH IN MID AND UPPER LEVELS CONTINUES TO PROGRESS DOWNSTREAM FROM CENTRAL GREAT LAKES SW TO THE S CENTRAL U.S. WHERE IT BECOMES BROAD AND WEAK. THE SRN PORTION OF TROUGH OVER THE LOWER MS VALLEY IS WHERE SCT CONVECTION IS LOCATED ATTM. WEAK MID/UPPER LEVEL RIDGING IS LOCATED OVER OUR FORECAST AREA AT THIS TIME. MEAN 1000-700 MB FLOW HAS TURNED MORE SLY AND PWATS HAVE INCREASED TO NEAR NORMAL LEVELS PER 00Z JAX SOUNDING AT 1.53 INCHES. OTHERWISE... PARTLY TO MOSTLY CLOUDY SKIES ACROSS THE CWA. SLY FLOW APPEARS TO BE ENHANCING ISENTROPIC UPGLIDE ACROSS PARTS OF CWA WITH LOW STRATUS AT TIMES WITH PATCHY FOG. .SHORT TERM... TODAY...WEAK FLOW IN THE MID LEVELS WITH LITTLE DYNAMIC FORCING FOR CONVECTION AND STEERING FLOW IS GENERALLY S TO SW AT 5-10 MPH. HOWEVER...MODEL SOUNDINGS SHOW THE SUBSIDENCE INVERSION QUITE A BIT WEAKER TODAY AND WEAKER SELY LLVL WINDS. GIVEN THIS PATTERN AND HIGHER PWAT AIR...RAIN CHANCES ARE HIGHER ACROSS THE ENTIRE CWA BUT BEST CHANCES WILL GENERALLY BE ACROSS INLAND NE FL AS SELY FLOW MEETS UP WITH A W COAST SEA BREEZE THAT WILL BE MORE ACTIVE. MODIFIED SBCAPE TODAY ANYWHERE FROM ABOUT 1700-2600 J/JG AND LI -5 TO -6. MAIN ISSUE FOR AFTERNOON CONVECTION WILL BE GUSTY WINDS...LIGHTNING AND LOCALLY HEAVY RAINFALL. RAIN CHANCES BECOME ELEVATED ALONG THE ERN ZONES IN THE MORNING AND THEN PROCEED TO INCREASE INLAND AREAS AS DAYTIME HEATING BECOMES MAXIMIZED AND SEA BREEZES AND OUTFLOW MERGE. HIGHS WILL BE WARMER BY A COUPLE OF DEGREES IN THE MID/UPPER 80S E ZONES TO NEAR 90 INLAND. NOT AS BREEZY WITH ELY WINDS AROUND 15 MPH OVER THE COASTAL AREAS AND 5-10 MPH INLAND. TONIGHT...ISOLD TO SCT CONVECTION ANTICIPATED IN THE 8PM-MIDNIGHT TIME FRAME MAINLY OVER LAND AREAS. BEST CHANCES WILL BE NEAR AND W OF HIGHWAY 301. PARTLY TO MOSTLY CLOUDY SKIES AND MOIST CONDITIONS WILL ALLOW FOR MILD OVERNIGHT LOWS IN THE LOWER TO MID 70S. IN ADDITION...LOW CLOUDS AND PATCHY FOG WILL BE POSSIBLE AFTER MIDNIGHT. MONDAY AND TUESDAY... WARM MOIST SOUTHWEST FLOW AHEAD OF AN APPROACHING MID LEVEL TROUGH WILL RESULT IN NUMEROUS SHOWERS AND THUNDERSTORMS ON MONDAY. A FEW STRONG STORMS WILL BE POSSIBLE AND CAPABLE OF STRONG DOWNBURSTS AND LOCALLY HEAVY RAINFALL. MULTI-LAYERED CLOUDINESS AND RAIN SHOULD KEEP TEMPS DOWN A BIT SO WE WILL LOWER TEMPS A COUPLE OF DEGREES AND GO WITH HIGHS IN THE UPPER 80S INLAND AND MID 80S COAST. THE MID LEVEL TROUGH AXIS WILL PIVOT ACROSS THE REGION MONDAY NIGHT WHICH WILL ALLOW A FEW SHOWERS AND THUNDERSTORMS TO CONTINUE OVER PORTIONS OF THE AREA THROUGH THE NIGHT. NOW BEGINNING TO LOOK AS THOUGH DEEP LAYER MOISTURE WILL LINGER ACROSS PORTIONS OF NORTHEAST FLORIDA ON TUESDAY...THUS WE WILL INCREASE RAIN CHANCES TO 50-60% IN NORTHEAST FLORIDA ON TUESDAY. SOME DRIER AIR ALOFT WILL KEEP POPS AT 30-40% ACROSS SOUTHEAST GEORGIA. HIGHS ON TUESDAY WILL RANGE FROM THE LOW 90S ACROSS INLAND SOUTHEAST GEORGIA TO THE UPPER 80S ACROSS OUR SOUTHERN ZONES. WILL KEEP A LOW CHANCE OF RAIN GOING TUESDAY NIGHT AS MOISTURE BEGINS TO INCREASE FROM THE SOUTH. WARM AND MUGGY NIGHTTIME TEMPS WILL PREVAIL. .LONG TERM /WEDNESDAY THROUGH SATURDAY/... THE MEDIUM RANGE MODELS WITH THE 0Z RUN WERE FAIRLY SIMILAR IN SHOWING A WEAK LOW PRESSURE SYSTEM MOVING NORTHEAST OUT OF THE GULF OF MEXICO AND ACROSS THE FLORIDA PENINSULA DURING THE THURSDAY NIGHT/FRIDAY TIMEFRAME. ALTHOUGH IT WILL DEPEND ON THE EXACT TRACK OF THE LOW...PORTIONS OF THE AREA COULD SEE HEAVY RAINFALL AND GUSTY WINDS LATE IN THE WEEK. WOULD LIKE TO SEE A LITTLE MORE RUN TO RUN CONSISTENCY IN THE MODELS BEFORE HITTING THIS TOO HARD. IN THE MEANTIME...WE WILL CONTINUE TO ADVERTISE A 40 TO 50 PERCENT CHANCE OF RAIN WEDNESDAY THROUGH FRIDAY. SEASONABLY WARM AND HUMID CONDITIONS WILL CONTINUE. && .AVIATION...LIFR CIGS MAY PERSIST AT GNV THROUGH 13Z WITH CIGS BECOMING MVFR 13Z-17Z. FOR REST OF TAFS OCNL TO PREVAILING MVFR CIGS EXPECTED THROUGH MID MORNING. OVERALL RAIN CHANCES ARE BETTER DURING THE DAYTIME TODAY. IN FACT...APPEARS THERE IS A CHANCE OF SHOWERS FROM ABOUT 11Z-16Z AS LLVL CONVERGENCE INCREASES OVER THE ERN ZONES SO VCSH IN PLACE FOR JAX METRO TAFS AND SSI. SHOWERS AND POSSIBLE STORMS COULD AFFECT GNV TAF IN THE AFTN WITH VCTS BY 18Z BUT THINK ITS TOO EARLY TO INCLUDE TEMPO GROUP. VCSH HAS BEEN PLACED IN FROM 00Z TO 06Z TONIGHT. && .MARINE...SEAS REMAIN AROUND 4-6 FT OFFSHORE EARLY THIS MORNING WITH WITH ESE SWELL OF ABOUT 3-4 FT NEAR 8-9 SECONDS. WINDS AND SEAS SHOULD GRADUALLY DECREASE TODAY AS RIDGE OVER THE WESTERN ATLANTIC BEGINS MOVING EASTWARD WHILE A WEAKENING COLD FRONT APPROACHES FROM THE NORTHWEST. A RELATIVELY WEAK PRESSURE PATTERN WILL RESULT IN LIGHTER WINDS THROUGH THE FIRST HALF OF THE WEEK. AN INCREASE IN WINDS IS EXPECTED DURING THE SECOND HALF OF THE WEEK BUT THE STRENGTH OF THE WINDS WILL DEPEND ON THE TRACK OF AN AREA OF LOW PRESSURE MOVING OUT OF THE GULF OF MEXICO IN THE THURSDAY/FRIDAY TIMEFRAME. SMALL CRAFT ADVISORY WINDS WILL BE POSSIBLE. RIP CURRENTS: A MODERATE TO HIGH RISK OF RIP CURRENTS TODAY DUE TO PERSISTENT ONSHORE FLOW. MODERATE RISK LIKELY FOR MON DUE TO E TO SE SWELLS. && .PRELIMINARY POINT TEMPS/POPS... AMG 90 70 88 69 / 40 30 70 60 SSI 83 74 84 74 / 30 20 60 60 JAX 87 71 87 71 / 40 20 60 60 SGJ 84 72 84 72 / 40 20 60 60 GNV 89 70 89 70 / 60 40 70 60 OCF 90 71 89 71 / 60 40 70 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ SHASHY/SHULER/
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
228 AM CDT SUN JUN 2 2013 .DISCUSSION... 308 PM CDT CONVECTIVE TRENDS ARE THE MAIN FORECAST ISSUE THIS AFTERNOON. WILL MAINTAIN FLASH FLOOD WATCH ACROSS SOUTHERN TIER OF COUNTIES THROUGH ITS 00Z EXPIRATION. SURFACE LOW PRESSURE WAS CENTERED OVER CENTRAL WI AT MID AFTERNOON...WITH A COLD FRONT EXTENDING SOUTH THROUGH THE MISSISSIPPI RIVER VALLEY THEN SOUTHWEST ACROSS MISSOURI. DESPITE CONSIDERABLE CLOUD COVER NORTHWEST/WEST CENTRAL IL HAS DESTABILIZED AS EXPECTED THIS AFTERNOON...WITH SCATTERED SHRA/TSRA DEVELOPING ACROSS THE UIN-PIA-PNT AT 19Z. SPC RAP MESOANALYSIS GUIDANCE INDICATES AN AXIS OF 500-1000 J/KG AND GENERALLY CONVERGENT LOW LEVEL FLOW IN THAT REGION AHEAD OF THE SFC COLD FRONT...AND EXPECT THAT THIS ACTIVITY WILL CONTINUE TO DEVELOP AND SPREAD NORTHEAST OVER THE NEXT SEVERAL HOURS AIDED BY LARGE SCALE ASCENT ASSOCIATED WITH SHORT WAVE TROUGH PROPAGATING ACROSS IA/MO PER GOES WATER VAPOR IMAGERY. SUCCESSIVE RUNS OF THE HRRR HAVE MAINTAINED THE IDEA OF SCATTERED STORMS/SMALL CLUSTERS LIFTING NORTHEAST THROUGH THE CHICAGO METRO AREA THROUGH 23-01Z OR SO...BEFORE DIURNAL DECREASE IN INSTABILITY WITH SUNSET RESULTS IN DECREASE IN COVERAGE THIS EVENING. WHILE WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED...WITH EFFECTIVE BULK SHEAR APPROACHING 30 KT AND DRIER AIR ALOFT...MAINLY WEST WHERE A DCAPE AXIS OF 600-800 J/KG IS ANALYZED...WE COULD SEE A FEW OF THE STRONGEST CELLS PRODUCE A LITTLE HAIL OR WIND DURING THE REMAINDER OF THE AFTERNOON HOURS. ORGANIZED HEAVY RAINFALL SEEMS A FAIRLY LOW PROBABILITY AT THIS POINT...THOUGH ANALYSIS/GUIDANCE CONTINUES TO DEPICT PWATS NEAR 1.5 INCHES...BETTER LOW LEVEL MOISTURE TRANSPORT AND SLIGHTLY SLOWER STORM PROPAGATION POTENTIAL ACROSS THE SOUTHEASTERN COUNTIES OF THE CWA. SINCE A FLASH FLOOD WATCH IS ALREADY IN PLACE THERE...AND WITH THESE AREAS HAVING RECEIVED BETWEEN 2-3 INCHES OF RAINFALL IN YESTERDAY/LAST NIGHTS MCS/S...ILL ALLOW THE WATCH TO RUN THROUGH ITS 00Z EXPIRATION. COLD FRONT AND MID-LEVEL TROUGH AXIS PUSH ACROSS THE CWA THIS EVENING...WITH DRIER AIR AND HEIGHT RISES SPREADING IN FROM THE WEST OVERNIGHT. WEAKER SECONDARY FRONT TRAILS ACROSS THE AREA SUNDAY MORNING HOWEVER...WITH MOST GUIDANCE RUNS INDICATING THE POTENTIAL FOR A FEW SPOTTY SHOWERS MAINLY ACROSS EAST/SOUTHEAST PARTS OF THE FORECAST AREA. BEYOND THAT...SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA LATER SUNDAY THROUGH MONDAY MAKING FOR A COUPLE OF DAYS OF DRY AND COOLER WEATHER WITH AFTERNOON LAKE BREEZES. GUIDANCE REASONABLE IN DEPICTING TEMPS IN THE MID/UPPER 60S SUNDAY...AND MID 60S TO LOWER 70S MONDAY...WITH LOWER 60S LIKELY ALONG THE LAKE MICHIGAN SHORES. LOWS ARE EXPECTED TO BE IN THE 40S IN MANY AREAS AWAY FROM THE CHICAGO METRO SPRAWL SUNDAY NIGHT AND AGAIN MONDAY NIGHT. UPPER LEVEL RIDGE AXIS DEVELOPS ACROSS THE REGION INTO TUESDAY... WHILE CLOSED UPPER LOW CURRENTLY OFF THE BRITISH COLUMBIA COAST MAKES ITS WAY INTO THE NORTHERN PLAINS. AS THIS OCCURS...THE SFC HIGH OVER THE WESTERN LAKES WILL DRIFT TO THE EAST...WITH LOW LEVEL FLOW MORE SOUTH-SOUTHEAST ACROSS THE PLAINS AND MISSISSIPPI VALLEY BY MID-WEEK. THIS RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION WILL INITIALLY FOCUS ACROSS THE PLAINS AND INTO IA/MN TUESDAY/TUESDAY NIGHT...BUT WILL SHIFT FARTHER EAST AND BRING SHRA/TSRA CHANCES BACK TO OUR AREA LATER TUESDAY NIGHT AND WEDNESDAY. SOME GUIDANCE HINTS AT A FEW SHRA/TSRA MOVING INTO OUR NORTHWEST COUNTIES TUESDAY AFTERNOON...THOUGH THESE SHOULD BE DECAYING AS THEY MOVE OUT OF THE BETTER FORCING/MOISTURE WEST OF THE MISSISSIPPI AND HAVE MAINTAINED DRY FORECAST THROUGH THE DAY TUESDAY WITH LOW CONFIDENCE OF ANY PRECIP OF SIGNIFICANCE MAKING IT THIS FAR EAST. SHRA/TSRA CHANCES THEN INCREASE WEDNESDAY THROUGH THURSDAY AS UPPER LOW AND INVERTED SURFACE TROUGH/COLD FRONT MOVE ACROSS THE AREA. UPPER LOW FILLS AND OPENS UP DURING THIS TIME...WITH SOUTH WARM/MOIST ADVECTION FLOW NOT TERRIBLY STRONG. SUSPECT THERE WILL BE MANY DRY HOURS BETWEEN CLUSTERS OF SHRA/TSRA DURING THIS PERIOD. TEMPS MODERATE BACK INTO THE LOW-MID 70S/NEAR NORMAL DURING THE MID-WEEK PERIOD...THOUGH SOUTHEAST SYNOPTIC WINDS WILL KEEP WINDS OFF THE LAKE PARTICULARLY ACROSS NORTHEAST IL. SURFACE COLD FRONT SETTLES SLOWLY OFF TO THE SOUTH/SOUTHEAST OF THE CWA THURSDAY NIGHT...THOUGH UPPER TROUGH AXIS LINGERS ACROSS THE REGION INTO NEXT WEEKEND. HAVE HELD ONTO SOME SLIGHT CHANCE POPS FRIDAY WITH THE TROUGH AXIS OVERHEAD AND THE ECMWF CONTINUING TO SQUEEZE OUT QPF...THOUGH DRIER LOW LEVEL FLOW AROUND SFC HIGH PRESSURE OVER THE NORTHERN LAKES SHOULD HELP MAINTAIN GENERALLY DRY CONDITIONS BY FRIDAY NIGHT/SATURDAY. TEMPS DURING THE PERIOD EXPECTED TO BE NEAR NORMAL...70S...THOUGH ONSHORE WINDS OFF THE BIG POND WILL KEEP CONDITIONS COOLER NEAR THE LAKE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MVFR CIGS PROBABLE BEHIND COLD FRONT THIS MORNING. * PERIOD OF IFR CIGS POSSIBLE...NAMELY IN THE 11Z-15Z FRAME. * WIND SHIFT TO NE THIS AFTERNOON WITH LAKE BREEZE. //DISCUSSION...UPDATED 06Z... LOW PRESSURE ACROSS LOWER MI VERY EARLY THIS MORNING WILL DEPART TO THE NORTHEAST WITH COLD AIR ADVECTION IN THE LOW-LEVELS ENVELOPING THE AREA PRIOR TO DAYBREAK BEHIND A COLD FRONT. IN THE IMMEDIATE POST FROPA AIRMASS UPSTREAM THERE ARE WIDESPREAD MVFR CIGS WITH OCCASIONAL IFR...NAMELY IN NORTHERN WI. IF A MORE NORTHERLY COMPONENT TO THE WIND WERE TO UNFOLD...WHICH COULD OCCUR ALONG THE WESTERN SIDE OF LAKE MI...THEN THAT COULD USHER THOSE IFR CIGS CLOSE OR POSSIBLY TO ORD AND MDW BETWEEN MAINLY 11Z AND 15Z. CIGS SHOULD LIFT ABOVE 1500 FT BY LATE MORNING/EARLY AFTERNOON BUT LIKELY BE SLOW TO SCATTER THROUGH THE AFTERNOON. IN ADDITION BEHIND THE FRONT THERE WILL BE AN INCREASE IN NORTHWEST WIND SPEEDS. GUSTS TO AROUND 20 KT ARE POSSIBLE LOOKING AT UPSTREAM OBS AND VAD WIND PROFILER DATA...AS SPEEDS OF 20 KT ARE ALREADY OBSERVED AT 2K FT /AND LIKELY UNDER/. A LAKE BREEZE WILL LIKELY DEVELOP TODAY INFLUENCING MDW AND GYY AND LIKELY ORD AND LATE IN THE DAY DPA. HAVE GONE WITH WIND DIRECTION NEAR CLIMATOLOGY FOR THIS. //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN WIND TRENDS. * MEDIUM CONFIDENCE IN 1500 FT OR LOWER CIGS THIS MORNING BUT LOW CONFIDENCE IN IFR OCCURRING AT ORD. MEDIUM CONFIDENCE IN TIMING. * MEDIUM-HIGH CONFIDENCE ON WIND SHIFT TO NORTHEAST AND ITS TIMING THIS AFTERNOON. //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY AND TUESDAY...VFR. WEDNESDAY THROUGH FRIDAY...CHANCE OF SHRA/TSRA. MTF/IZZI && .MARINE... 226 AM CDT THE MOST ACTIVE PERIOD OVER LAKE MICHIGAN IN THIS NEXT WEEK WILL BE TODAY AS COLD AIR ADVECTION IN THE WAKE OF A DEEPENING DEPARTING LOW WILL EXPAND DOWN THE LAKE THROUGH MIDDAY. THE COMBINATION OF THE COOLER AIR PUSH AND A TIGHT PRESSURE GRADIENT WILL OFFER NORTHWEST TO NORTH WINDS IN MAINLY THE 20-25 KT BALLPARK THOUGH CANT RULE OUT A FEW HIGHER GUSTS. THE INDIANA NEAR SHORE WILL BE CLOSE TO SMALL CRAFT CRITERIA TODAY GIVEN THOSE GUSTS. HIGH PRESSURE WILL QUICKLY EXPAND IN TONIGHT ON THE WAKE OF THIS LOW. A WEAK TROUGH LOOKS TO MOVE OVER THE LAKE SOMETIME WEDNESDAY OR WEDNESDAY NIGHT...WITH HIGH PRESSURE THEN RETURNING FOR THE END OF THE WEEK. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1240 AM CDT SUN JUN 2 2013 .DISCUSSION... 308 PM CDT CONVECTIVE TRENDS ARE THE MAIN FORECAST ISSUE THIS AFTERNOON. WILL MAINTAIN FLASH FLOOD WATCH ACROSS SOUTHERN TIER OF COUNTIES THROUGH ITS 00Z EXPIRATION. SURFACE LOW PRESSURE WAS CENTERED OVER CENTRAL WI AT MID AFTERNOON...WITH A COLD FRONT EXTENDING SOUTH THROUGH THE MISSISSIPPI RIVER VALLEY THEN SOUTHWEST ACROSS MISSOURI. DESPITE CONSIDERABLE CLOUD COVER NORTHWEST/WEST CENTRAL IL HAS DESTABILIZED AS EXPECTED THIS AFTERNOON...WITH SCATTERED SHRA/TSRA DEVELOPING ACROSS THE UIN-PIA-PNT AT 19Z. SPC RAP MESOANALYSIS GUIDANCE INDICATES AN AXIS OF 500-1000 J/KG AND GENERALLY CONVERGENT LOW LEVEL FLOW IN THAT REGION AHEAD OF THE SFC COLD FRONT...AND EXPECT THAT THIS ACTIVITY WILL CONTINUE TO DEVELOP AND SPREAD NORTHEAST OVER THE NEXT SEVERAL HOURS AIDED BY LARGE SCALE ASCENT ASSOCIATED WITH SHORT WAVE TROUGH PROPAGATING ACROSS IA/MO PER GOES WATER VAPOR IMAGERY. SUCCESSIVE RUNS OF THE HRRR HAVE MAINTAINED THE IDEA OF SCATTERED STORMS/SMALL CLUSTERS LIFTING NORTHEAST THROUGH THE CHICAGO METRO AREA THROUGH 23-01Z OR SO...BEFORE DIURNAL DECREASE IN INSTABILITY WITH SUNSET RESULTS IN DECREASE IN COVERAGE THIS EVENING. WHILE WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED...WITH EFFECTIVE BULK SHEAR APPROACHING 30 KT AND DRIER AIR ALOFT...MAINLY WEST WHERE A DCAPE AXIS OF 600-800 J/KG IS ANALYZED...WE COULD SEE A FEW OF THE STRONGEST CELLS PRODUCE A LITTLE HAIL OR WIND DURING THE REMAINDER OF THE AFTERNOON HOURS. ORGANIZED HEAVY RAINFALL SEEMS A FAIRLY LOW PROBABILITY AT THIS POINT...THOUGH ANALYSIS/GUIDANCE CONTINUES TO DEPICT PWATS NEAR 1.5 INCHES...BETTER LOW LEVEL MOISTURE TRANSPORT AND SLIGHTLY SLOWER STORM PROPAGATION POTENTIAL ACROSS THE SOUTHEASTERN COUNTIES OF THE CWA. SINCE A FLASH FLOOD WATCH IS ALREADY IN PLACE THERE...AND WITH THESE AREAS HAVING RECEIVED BETWEEN 2-3 INCHES OF RAINFALL IN YESTERDAY/LAST NIGHTS MCS/S...ILL ALLOW THE WATCH TO RUN THROUGH ITS 00Z EXPIRATION. COLD FRONT AND MID-LEVEL TROUGH AXIS PUSH ACROSS THE CWA THIS EVENING...WITH DRIER AIR AND HEIGHT RISES SPREADING IN FROM THE WEST OVERNIGHT. WEAKER SECONDARY FRONT TRAILS ACROSS THE AREA SUNDAY MORNING HOWEVER...WITH MOST GUIDANCE RUNS INDICATING THE POTENTIAL FOR A FEW SPOTTY SHOWERS MAINLY ACROSS EAST/SOUTHEAST PARTS OF THE FORECAST AREA. BEYOND THAT...SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA LATER SUNDAY THROUGH MONDAY MAKING FOR A COUPLE OF DAYS OF DRY AND COOLER WEATHER WITH AFTERNOON LAKE BREEZES. GUIDANCE REASONABLE IN DEPICTING TEMPS IN THE MID/UPPER 60S SUNDAY...AND MID 60S TO LOWER 70S MONDAY...WITH LOWER 60S LIKELY ALONG THE LAKE MICHIGAN SHORES. LOWS ARE EXPECTED TO BE IN THE 40S IN MANY AREAS AWAY FROM THE CHICAGO METRO SPRAWL SUNDAY NIGHT AND AGAIN MONDAY NIGHT. UPPER LEVEL RIDGE AXIS DEVELOPS ACROSS THE REGION INTO TUESDAY... WHILE CLOSED UPPER LOW CURRENTLY OFF THE BRITISH COLUMBIA COAST MAKES ITS WAY INTO THE NORTHERN PLAINS. AS THIS OCCURS...THE SFC HIGH OVER THE WESTERN LAKES WILL DRIFT TO THE EAST...WITH LOW LEVEL FLOW MORE SOUTH-SOUTHEAST ACROSS THE PLAINS AND MISSISSIPPI VALLEY BY MID-WEEK. THIS RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION WILL INITIALLY FOCUS ACROSS THE PLAINS AND INTO IA/MN TUESDAY/TUESDAY NIGHT...BUT WILL SHIFT FARTHER EAST AND BRING SHRA/TSRA CHANCES BACK TO OUR AREA LATER TUESDAY NIGHT AND WEDNESDAY. SOME GUIDANCE HINTS AT A FEW SHRA/TSRA MOVING INTO OUR NORTHWEST COUNTIES TUESDAY AFTERNOON...THOUGH THESE SHOULD BE DECAYING AS THEY MOVE OUT OF THE BETTER FORCING/MOISTURE WEST OF THE MISSISSIPPI AND HAVE MAINTAINED DRY FORECAST THROUGH THE DAY TUESDAY WITH LOW CONFIDENCE OF ANY PRECIP OF SIGNIFICANCE MAKING IT THIS FAR EAST. SHRA/TSRA CHANCES THEN INCREASE WEDNESDAY THROUGH THURSDAY AS UPPER LOW AND INVERTED SURFACE TROUGH/COLD FRONT MOVE ACROSS THE AREA. UPPER LOW FILLS AND OPENS UP DURING THIS TIME...WITH SOUTH WARM/MOIST ADVECTION FLOW NOT TERRIBLY STRONG. SUSPECT THERE WILL BE MANY DRY HOURS BETWEEN CLUSTERS OF SHRA/TSRA DURING THIS PERIOD. TEMPS MODERATE BACK INTO THE LOW-MID 70S/NEAR NORMAL DURING THE MID-WEEK PERIOD...THOUGH SOUTHEAST SYNOPTIC WINDS WILL KEEP WINDS OFF THE LAKE PARTICULARLY ACROSS NORTHEAST IL. SURFACE COLD FRONT SETTLES SLOWLY OFF TO THE SOUTH/SOUTHEAST OF THE CWA THURSDAY NIGHT...THOUGH UPPER TROUGH AXIS LINGERS ACROSS THE REGION INTO NEXT WEEKEND. HAVE HELD ONTO SOME SLIGHT CHANCE POPS FRIDAY WITH THE TROUGH AXIS OVERHEAD AND THE ECMWF CONTINUING TO SQUEEZE OUT QPF...THOUGH DRIER LOW LEVEL FLOW AROUND SFC HIGH PRESSURE OVER THE NORTHERN LAKES SHOULD HELP MAINTAIN GENERALLY DRY CONDITIONS BY FRIDAY NIGHT/SATURDAY. TEMPS DURING THE PERIOD EXPECTED TO BE NEAR NORMAL...70S...THOUGH ONSHORE WINDS OFF THE BIG POND WILL KEEP CONDITIONS COOLER NEAR THE LAKE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * MVFR CIGS PROBABLE BEHIND COLD FRONT THIS MORNING. * PERIOD OF IFR CIGS POSSIBLE...NAMELY IN THE 11Z-15Z FRAME. * WIND SHIFT TO NE THIS AFTERNOON WITH LAKE BREEZE. //DISCUSSION...UPDATED 06Z... LOW PRESSURE ACROSS LOWER MI VERY EARLY THIS MORNING WILL DEPART TO THE NORTHEAST WITH COLD AIR ADVECTION IN THE LOW-LEVELS ENVELOPING THE AREA PRIOR TO DAYBREAK BEHIND A COLD FRONT. IN THE IMMEDIATE POST FROPA AIRMASS UPSTREAM THERE ARE WIDESPREAD MVFR CIGS WITH OCCASIONAL IFR...NAMELY IN NORTHERN WI. IF A MORE NORTHERLY COMPONENT TO THE WIND WERE TO UNFOLD...WHICH COULD OCCUR ALONG THE WESTERN SIDE OF LAKE MI...THEN THAT COULD USHER THOSE IFR CIGS CLOSE OR POSSIBLY TO ORD AND MDW BETWEEN MAINLY 11Z AND 15Z. CIGS SHOULD LIFT ABOVE 1500 FT BY LATE MORNING/EARLY AFTERNOON BUT LIKELY BE SLOW TO SCATTER THROUGH THE AFTERNOON. IN ADDITION BEHIND THE FRONT THERE WILL BE AN INCREASE IN NORTHWEST WIND SPEEDS. GUSTS TO AROUND 20 KT ARE POSSIBLE LOOKING AT UPSTREAM OBS AND VAD WIND PROFILER DATA...AS SPEEDS OF 20 KT ARE ALREADY OBSERVED AT 2K FT /AND LIKELY UNDER/. A LAKE BREEZE WILL LIKELY DEVELOP TODAY INFLUENCING MDW AND GYY AND LIKELY ORD AND LATE IN THE DAY DPA. HAVE GONE WITH WIND DIRECTION NEAR CLIMATOLOGY FOR THIS. //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH CONFIDENCE IN WIND TRENDS. * MEDIUM CONFIDENCE IN 1500 FT OR LOWER CIGS THIS MORNING BUT LOW CONFIDENCE IN IFR OCCURRING AT ORD. MEDIUM CONFIDENCE IN TIMING. * MEDIUM-HIGH CONFIDENCE ON WIND SHIFT TO NORTHEAST AND ITS TIMING THIS AFTERNOON. //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY AND TUESDAY...VFR. WEDNESDAY THROUGH FRIDAY...CHANCE OF SHRA/TSRA. MTF/IZZI && .MARINE... 218 PM CDT MODERATE SOUTHERLY WINDS ARE OCCURRING AHEAD OF AN AREA OF LOW PRESSURE AND ITS ATTENDANT COLD FRONT WHICH ARE EXPECTED TO PASS OVER THE LAKE TONIGHT. A BRIEF LULL IN THE WINDS MAY OCCUR WITH THE FRONTAL TROUGH THIS EVENING...BUT THEN WINDS ARE EXPECTED TO SHIFT TO NORTHWESTERLY AND RAMP BACK UP INTO THE 20 TO 25 KT RANGE FOR MUCH OF THE LAKE OVERNIGHT. WINDS SHOULD COME DOWN THROUGH THE DAY SUNDAY...REMAINING RELATIVELY LIGHT ON MONDAY WITH LAKE BREEZES DEVELOPING. ANOTHER AREA OF LOW PRESSURE BEGINS TO TAKE SHAPE OVER THE PLAINS LATE MONDAY INTO TUESDAY WITH SOUTHEASTERLY WINDS FRESHENING UP TO PERHAPS 15 TO 20 KT AT TIMES THROUGH THURSDAY. THURSDAY NIGHT...THE LOW WEAKENS AS IT PASSES SOUTH OF THE LAKE WITH WINDS TURNING NORTHERLY FRIDAY THROUGH THE WEEKEND. BMD && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
415 AM CDT SUN JUN 2 2013 .SHORT TERM... MOST ACTIVE PORTION OF THE FORECAST WILL BE OVER THE NEXT 12 TO 15 HOURS. SURFACE ANALYSIS SHOWS COLD FRONT DRAPED ACROSS SOUTH-CENTRAL TEXAS...NORTHERN LA THROUGH EASTERN ARKANSAS AND POINTS FURTHER NORTH. A LARGE CLUSTER OF SHOWERS AND EMBEDDED STRONGER THUNDERSTORMS AHEAD OF THE FRONT HAS BEEN SURGING SOUTHWARD OVERNIGHT. AT THIS POINT...THIS ACTIVITY HAS BECOME OUTFLOW DRIVEN VS THE MEAN FLOW WHICH WOULD BE MORE EASTERLY. HRRR SEEMS TO BE THE ONLY MESO MODEL THAT HAS BEEN HAVING A GOOD INITIATION. IT SUGGESTS A WEAKENING TREND WILL CONTINUE AS THE LEADING EDGE MOVES SOUTH ACROSS MS AND LA TOWARDS THE CWA. WHILE IN GENERAL THIS WILL LIKELY BE THE CASE...THERE/S STILL SOME INSTABILITY IN PLACE OVER THE AREA WHICH WILL ALLOW A FEW CELLS TO BURST UP TO STRONG CATEGORY WITH STRONG GUSTY WINDS. HAVE SLIGHTLY BUMPED UP POPS TODAY...MAINLY TO ACCOUNT FOR ACTIVITY THAT SHOULD BE GOING ON THIS MORNING. AFTER IT DISSIPATES... DEVELOPMENT OF AFTERNOON SHOWERS AND A FEW THUNDERSTORMS WILL STILL BE POSSIBLE AS INSTABILITY REMAINS IN PLACE. COLD FRONT WILL STILL BE PUSHING SOUTH THROUGHOUT THE NIGHT AND SHOULD BE REACHING THE COAST BY 12Z MONDAY. HAVE TRIMMED POPS FURTHER SOUTH FOR THE MORNING PERIOD SO THAT ONLY COASTAL PARISHES AND OFFSHORE WATERS HAVE WORDING OF RAIN IN THE ZONES. .LONG TERM... WEAK UPPER LEVEL RIDGING WILL BUILD INTO THE AREA MID WEAK AS UPPER TROUGH EJECTS. SUBSEQUENTLY...RAIN CHANCES WILL DROP OFF MONDAY AFTERNOON THROUGH WEDNESDAY. IN ADDITION...DAYTIME HIGHS WILL BE ON THE RISE AS HEIGHTS INCREASE. TEMPS SHOULD MAKE IT TO THE 90 TO 93 DEGREE MARK FAIRLY EASILY. AN UPPER TROUGH WILL TRACK ACROSS THE UPPER MISSISSIPPI VALLEY IN THE LATTER PORTION OF THIS WEEK. THIS WILL BREAKDOWN THE EAST SIDE OF UPPER RIDGE OVER THE GULF COAST THUS ALLOWING FOR AFTERNOON SHOWERS AND THUNDERSTORMS TO BEGIN DEVELOPING AGAIN. MEFFER &&.AVIATION... AS HAS BEEN THE CASE FOR SEVERAL NIGHTS...THE OVERNIGHT AVIATION PROBLEM WILL BE THE DEVELOPMENT OF LOW CLOUDS. SEEING SOME DEVELOPMENT IN THE FL015-FL025 RANGE...MOST NOTABLY AT KHUM...AT THIS TIME. EXPECT SCT-BKN CLOUDS TO BECOME WIDESPREAD ACROSS THE AREA BY 09Z AND REMAIN THROUGH ABOUT 15Z. ONE OR TWO SITES WILL LIKELY FALL INTO THE IFR RANGE...PROBABLY AT KMCB. THE OTHER PROBLEM WILL BE THE TIMING OF CONVECTION ASSOCIATED WITH THE FRONTAL BOUNDARY. CURRENT MOVEMENT APPEARS TO BE ABOUT 340/17 KTS. THIS WILL ALLOW CONVECTION TO REACH KMCB AND KBTR SOMETIME AROUND SUNRISE...ALTHOUGH A STRAY SHOWER OR TWO COULD REACH KMCB BEFORE THEN. EXPECT A WEAKENING TREND FROM WHAT IS BEING OBSERVED AT THIS TIME. WILL LEAD INTO EVENT WITH MENTION OF VCSH/VCTS AND CARRY ABOUT A 4 HOUR WINDOW WITH THE MAIN CONVECTION. FOR NOW...WILL ONLY USE TEMPO GROUPS AT KMCB...KBTR AND KHDC. WILL ADJUST LATER AS WE CAN BETTER ANTICIPATE TIMING AT TERMINALS FARTHER SOUTH AND EAST. STILL NOT CONFIDENT ON EXACTLY HOW FAR SOUTHWARD FRONT WILL MAKE IT ON SUNDAY BEFORE RUNNING OUT OF PUSH. WIND FIELD WILL LIKELY BECOME RATHER WEAK TOWARD EVENING. 35 && .MARINE... WIND FIELD IS CONSIDERABLY WEAKER THIS MORNING THAN IT HAS BEEN FOR SEVERAL DAYS. WITH A WEAKENING COLD FRONT ANTICIPATED TO MOVE INTO THE AREA TODAY...WIND FIELDS WILL BECOME EVEN LIGHTER. WIND DIRECTIONS WILL BE RATHER VARIABLE...BUT GENERALLY WITH AN EASTERLY COMPONENT. NOT EXPECTING WINDS TO BE MUCH ABOVE 10 KNOTS BEFORE THURSDAY...WITH THE POSSIBLE EXCEPTION OF THE USUAL EVENING DIURNAL MAXIMUM. EVEN THEN...DO NOT ANTICIPATE WINDS STRONG ENOUGH TO REQUIRE HEADLINES. 35 && .DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SLURRY SUPPORT. MONITORING RIVER FLOODING. MONITORING CONVECTIVE TRENDS. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 88 66 88 63 / 60 20 10 10 BTR 90 68 89 67 / 60 20 10 10 ASD 88 70 90 69 / 60 30 10 10 MSY 88 73 89 72 / 60 30 10 10 GPT 87 71 89 69 / 50 30 10 10 PQL 87 71 88 68 / 50 30 10 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
343 AM EDT SUN JUN 2 2013 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE WEST TODAY...THEN PASS THROUGH THE AREA TONIGHT AND MONDAY. CANADIAN HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT THROUGH MIDWEEK. ANOTHER FRONT MAY APPROACH THE MIDDLE ATLANTIC STATES AT THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AREA REMAINS UNDER THE INFLUENCE OF OFFSHORE HIGH PRESSURE EARLY THIS MORNING...WHILE A COLD FRONT WELL TO THE WEST ENTERS THE OHIO VALLEY. A LINE OF SHOWERS WITH LOCALLY HEAVY RAINFALL OVER SERN OHIO IS APPROACHING THE WV BORDER AS OF 0730Z...AND MAY IMPACT EASTERN WV BY MID-MORNING IF IT HOLDS TOGETHER. HRRR ALSO INDICATES POTENTIAL OF ADDITIONAL SHOWER ACTIVITY DEVELOPING AHEAD OF THIS LINE AND MOVING INTO EASTERN WV OR WRN VA EARLIER IN THE MORNING...BUT SO FAR THE MODEL HAS LARGELY OVERDONE THIS PRECIP OVERNIGHT. NO LONGER EXPECTING PRE-DAWN PATCHY FOG...AS DEW POINT DEPRESSIONS ARE MOSTLY AROUND 10 DEGREES AND PERSISTENT SLY FLOW SHOULD PREVENT TEMPS FROM DROPPING ENOUGH THE REST OF THE NIGHT. FOR SUNDAY...SURFACE COLD FRONT IS EXPECTED TO MOVE THROUGH THE OHIO VALLEY...BUT STILL BE WEST OF THE FORECAST AREA BY THE END OF THE AFTERNOON. A PRE-FRONTAL TROUGH IS EXPECTED TO DEVELOP AND AMPLIFY OVER THE MID-ATLANTIC. MID-LEVEL CLOUD COVER IS EXPECTED TO INCREASE FROM WEST TO EAST ACROSS THE FORECAST AREA...BUT IN SPITE OF IT CAPE IS EXPECTED TO REACH 1000-2000 J/KG RANGE BY LATE MORNING. WIND SHEAR WILL BE SUFFICIENT FOR STORM ORGANIZATION AS THE MID-UPPER LEVEL JET STREAM APPROACHES FROM THE WEST. DYNAMICS LOOK STRONGER ON THE 00Z MODEL RUNS THAN PREVIOUSLY...AND SPC HAS EXTENDED THE SLIGHT RISK AREA SOUTHWARD TO INCLUDE THE ENTIRE CWA. FLOW IS EXPECTED TO BE MAINLY UNIDIRECTIONAL...SO MAIN THREAT WILL BE DAMAGING STRAIGHT LINE WINDS...ALTHOUGH LARGE HAIL IS ALSO POSSIBLE. PWATS IN FORECAST SOUNDINGS RUNNING AROUND 1.5 TO 2 INCHES...SO LOCALIZED FLASH FLOODING WILL ALSO BE POSSIBLE. FORECAST HIGHS WEIGHT MOST HEAVILY ON MOS BIAS CORRECTED GUIDANCE...WITH HIGHS IN THE LOW TO MID 80S WEST OF THE BLUE RIDGE AND IN THE UPPER 80S TO AROUND 90 EAST OF THE BLUE RIDGE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... COLD FRONT ENTERS THE CWA SUNDAY NIGHT. MODELS NOT YET CONSISTENT ON ITS EASTWARD PROGRESS BY MONDAY MORNING...WITH GFS HAVING THE FRONT THROUGH MOST OF THE AREA...ECMWF (12Z SUN) THE SLOWEST...AND THE NAM IN BETWEEN. WILL CONTINUE WITH POTENTIAL FOR SHOWERS AND TSTMS OVERNIGHT...WITH HIGHEST POPS EAST OF I-95 CORRIDOR. LOW TEMPS RANGE FROM THE LOW 60S OVER THE POTOMAC HIGHLANDS TO THE LOW 70S IN URBAN BALTIMORE/WASHINGTON. && .LONG TERM /MONDAY THROUGH SATURDAY/... COLD FRONT WILL BE MOVING THROUGH THE POTOMAC HIGHLANDS BY MONDAY MORNING. SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE AHEAD OF FROPA FOR AREAS ALONG AND EAST OF THE I-95 CORRIDOR THROUGHOUT THE MORNING AND AFTERNOON. FURTHER SOUTH AND EAST...LOW LEVEL JET WILL BECOME MORE PERPENDICULAR TO THE STORM MOTION AND HELP LEVITATE HEAVY RAIN THAT WE MAY SEE SUNDAY EVENING. FCST SOUNDINGS WILL STILL BE SATURATED WITH PWATS AT OR ABOVE 1.5 SO ISOLATED AREAS OF HEAVY RAIN WILL STILL POSE A THREAT FOR SOUTHERN MARYLAND MONDAY AFTERNOON WITHIN THUNDERSTORM ACTIVITY. HIGH PRESSURE AND NW FLOW BEHIND FROPA WILL DROP DEWPTS AS IT MOVES THROUGH THE MID ATLANTIC MONDAY NIGHT. CONTINENTAL AIR WILL BRING RELIEF OF RECENT WARM SPELL FOR THE START OF NEXT WEEK WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL. E-SE FLOW WILL BEGIN TUESDAY NIGHT AND USHER IN LOW LEVEL MOISTURE INTO THE MID ATLANTIC AS HIGH PRESSURE MOVES OFF SHORE. LOW PRESSURE FROM THE OHIO VALLEY WILL FORM ALONG A COLD FRONT AND MOVE TOWARDS THE REGION BY THE END OF THE WEEK. REGION SHOULD STAY DRY UNTIL THURSDAY NIGHT WHEN SHOWERS WILL OVERSPREAD THE AREA AS A UPPER TROUGH MOVES CLOSER. MULTIPLE SHORTWAVE TROUGHS AND LOW PRESSURE OFF THE ATLANTIC COAST MAY LEAD TO CLOUDY AND WET CONDITIONS TOWARDS THE END OF THE WEEK AND START OF THE WEEKEND. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... EXPECT VFR CONDITIONS OVERNIGHT THROUGH MIDDAY SUNDAY. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL DEVELOP SUNDAY AFTERNOON INTO SUNDAY NIGHT AND WILL LIKELY BRING IMPACTS TO THE TERMINALS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE DAMAGING WINDS...HAIL AND HEAVY RAINFALL. AMENDMENTS MAY BE NECESSARY TO REFINE TIMING AND IMPACT OF SHOWERS/TSTMS. WINDS GENERALLY SW 10-15KT...POSSIBLY GUSTY AT TIMES. VFR CONDITIONS EXPECTED FOR THE START OF THE WORK WEEK WITH THE EXCEPTION OF SOME ONGOING SHOWERS AT IAD-DCA-BWI-MTN MONDAY. WINDS WILL SHIFT FROM THE SW TO THE NW BY MONDAY EVENING ACROSS ALL TERMINALS. && .MARINE... SCA CONTINUES EARLY THIS MORNING ON THE SOUTHERN CHES BAY WITH GUSTS IN THE UPPER TEENS TO LOW 20S. SCA IS SCHEDULED TO EXPAND TO ALL WATERS AT 14Z THIS MORNING. PRESSURE GRADIENT ON 00Z MODEL RUN IS A LITTLE LESS THAN PREVIOUS RUNS...AND WIND DIRECTION IS EXPECTED TO BE MORE SWLY THAN SOUTHERLY...WHICH WOULD INHIBIT CHANNELING. AS SUCH...SCA CONDITIONS WILL LIKELY BE SOMEWHAT MARGINAL...BUT WILL KEEP THE ADVISORY IN PLACE. SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EARLY EVENING HAVE THE POTENTIAL TO PRODUCE STRONG WIND GUSTS...HEAVY RAIN AND HAIL. SHOWERS AND ISOLATED THUNDERSTORMS WILL BE ONGOING INTO THE START OF THE WORK WEEK. WINDS WILL SHIFT FROM THE SW TO THE NW BY MONDAY EVENING AS A COLD FRONT CROSSES. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR ANZ530>533-535>542. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ534- 543. && $$ SYNOPSIS...KCS NEAR TERM...KCS SHORT TERM...KCS LONG TERM...HAS AVIATION...HAS/KCS MARINE...HAS/KCS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
522 AM EDT SUN JUN 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 520 AM EDT SUN JUN 2 2013 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM NW ONTARIO INTO THE CNTRL GREAT LAKES. A SHORTWAVE SUPPORTING OVER NRN LAKE MICHIGAN INTO NW LOWER MI SUPPORTED AN AREA OF RAIN OVER ERN UPPER MI THAT WAS SLOWLY SLIDING OFF TO THE EAST. SCT LIGHT SHOWERS ALSO LINGERED OVER CNTRL UPPER MI. AT THE SFC...A TIGHT GRADIENT BETWEEN LOW PRES OVER LAKE HURON AND A RIDGE INTO THE NRN PLAINS SUPPORTED BRISK NRLY WINDS ACROSS LAKE SUPERIOR INTO THE UPPER MI. UPSLOPE NRLY FLOW INTO THE HIGHER TERRAIN ALSO SUPPORTED AREAS OF DRIZZLE. MUCH COLDER AIR HAS MOVED INTO THE REGION WITH TEMPS DROPPING INTO THE UPPER 30S AND LOWER 40S. TODAY...ALTHOUGH THE NAM AND HIGH RES MODELS SHOW LOW LEVEL DRYING WILL SPREAD THROUGH MOST OF THE CWA THIS MORNING...UPSTREAM CLOUDS TRENDS SUGGEST THAT THE CLEARING TREND MAY BE SLOWER. ANY LINGERING LIGHT SHOWERS OR DRIZZLE SHOULD END BY MID OR LATE MORNING WITH CLEARING FROM WEST TO EAST BY EARLY TO MID AFTERNOON. EVEN WITH SUNSHINE...WITH N FLOW ACROSS LAKE SUPERIOR AND 850 MB TEMPS NEAR -1C...TEMPS WILL STRUGGLE INTO THE UPPER 40S TO LOWER 50S NORTH AND INTO THE MID AND UPPER 50S SOUTH. TONIGHT...SFC HIGH PRES BUILDING INTO THE REGION FROM THE WEST SUNDAY NIGHT WILL RESULT IN IDEAL RADIATIONAL COOLING CONDITIONS OVER THE WESTERN INTERIOR OF THE CWA WHERE MIN TEMPS WILL LIKELY FALL INTO LOWER 30S...NEAR THE LOWER END OF GUIDANCE. SOME TRADITIONAL COLD SPOTS COULD ALSO SEE READINGS INTO THE UPPER 20S. SO...A FROST ADVISORY WAS ISSUED FOR INLAND PORTIONS OF THE WEST HALF OF UPPER MICHIGAN. A VORTEX DESCENDING FROM NRN ONTARIO IS EXPECTED TO GRAZE NE LAKE SUPERIOR. ALTHOUGH PCPN AND CLOUDS WITH THIS FEATURE ARE EXPECTED TO REMAIN THE NE OF THE CWA...THE VORTEX WILL RESULT IN NW WINDS STRONG ENOUGH TO MAINTAIN SOME BOUNDARY LAYER MIXING AND PREVENT TEMPS FROM DROPPING OFF AS FAR AS IN THE WEST. LOOK FOR MAINLY MID TO UPPER 30S MIN TEMPS OVER THE EAST HALF. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 343 AM EDT SUN JUN 2 2013 UPPER TROUGH THAT IS CURRENTLY AFFECTING THE UPPER GREAT LAKES EARLY THIS MORNING WILL BE SHIFTING EAST THROUGH EASTERN CANADA ON MONDAY. THIS WILL LEAD TO THE AREA BEING UNDER NORTHWEST FLOW ALOFT AND A SURFACE HIGH PRESSURE RIDGE FROM A HIGH CENTERED IN SOUTH CENTRAL CANADA. WITH DRY LOW AND MID LEVELS UNDER THE HIGH PRESSURE RIDGE...EXPECT A MOSTLY SUNNY SKY ACROSS MUCH OF THE LAND AREA. THERE COULD BE SOME LINGERING CLOUDS OVER NORTHEAST LAKE SUPERIOR AND FAR EASTERN UPPER MICHIGAN AS THE UPPER TROUGH DEPARTS. WITH THE SUNSHINE...EXPECT MIXING TO AROUND 850-825MB. BUT WITH TEMPERATURES AT THAT LEVEL ONLY AROUND 2C WEST AND -1C EAST...BELOW NORMAL HIGHS ARE EXPECTED AND ONLY IN THE 50S AND LOWER 60S. THE COOLEST TEMPERATURES WILL BE ALONG THE GREAT LAKES SHORELINES DUE TO LAKE BREEZES. THE OTHER ITEM TO MENTION FOR MONDAY WILL BE LOW RH VALUES. ML DEWPOINTS FROM THE MODELS INDICATE VALUES IN THE MID 20S OVER THE INTERIOR LOCATIONS AND POTENTIALLY THE UPPER TEENS IF THE GFS IS CORRECT. WITH THAT CONSISTENCY AND THE TRENDS IN THE MAV/MET...HAVE LOWERED OUR DEWPOINTS A GOOD 5-7 DEGREES. THIS PRODUCES RH VALUES OF 25-35 PERCENT OVER THE INLAND AREAS...WITH THE LOWEST VALUES OVER THE WEST. FORTUNATELY...THE WET WEATHER RECENTLY...GREEN UP WELL ON IT/S WAY OR EVEN DONE...AND BELOW NORMAL TEMPERATURES REDUCES FIRE WEATHER CONCERNS EVEN WITH 10-15KT WINDS. THE HIGH PRESSURE RIDGE WILL STILL BE OVER THE AREA ON MONDAY NIGHT AS AN UPPER RIDGE SLIDES ACROSS THE AREA. THE CLEAR SKIES...LIGHT WINDS...AND PWAT VALUES AROUND 30-40 PERCENT OF NORMAL WILL LEAD TO A COLD NIGHT ACROSS THE AREA. WILL CONTINUE THE TREND OF GOING BELOW GUIDANCE VALUES AND HAVE LOWS AROUND 30 OVER THE INTERIOR LOCATIONS. RECORD LOWS FOR JUNE 4 ARE IN THE MID-UPPER 20S...SO WE WILL BE CLOSE BUT LIKELY STAY ABOVE THE RECORD LOWS. WILL ALSO CONTINUE THE MENTION OF FROST FOR MONDAY NIGHT ALONG WITH HIGHLIGHTING IN HWO. AREA WILL STILL BE UNDER THE INFLUENCE OF THE HIGH ON TUESDAY...AS IT DRIFTS SOUTHEAST ACROSS THE CWA THROUGH THE DAY. THIS WILL LEAD TO LIGHTER WINDS ACROSS THE AREA. DO EXPECT TO SEE SOME HIGH CLOUDS STREAMING EAST ACROSS THE WESTERN CWA DURING THE AFTERNOON AHEAD OF THE NEXT SYSTEM APPROACHING THE AREA. HIGHS WILL BE A LITTLE WARMER ON TUESDAY...AS 850MB TEMPS WARM A COUPLE DEGREES FROM MONDAY. WITH THE RIDGE LINGERING OVER THE EAST...HAVE LOWERED TD VALUES SIGNIFICANTLY OVER THE EAST HALF. THIS WILL LIKELY LEAD TO ANOTHER LOW RH DAY...BUT AS WITH MONDAY...FIRE WX CONCERNS ARE LIMITED WITH EVEN LIGHTER WINDS. THE UPPER TROUGH CURRENTLY OVER BRITISH COLUMBIA WILL BE MOVING THROUGH THE NORTHERN PLAINS ON TUESDAY AND THEN BECOME CLOSE ENOUGH TO START INFLUENCING THE UPPER GREAT LAKES FOR TUESDAY NIGHT AND CONTINUING INTO THURSDAY. THERE ARE STILL QUESTIONS ON THE EXACT TRACK OF THE SHORTWAVE TROUGH...WHICH IN TURN AFFECTS THE LOCATION OF THE SURFACE LOW AND RESULTANT WARM AIR ADVECTION PRECIPITATION. LATEST IDEA FROM THE GFS/ECMWF IS THAT MUCH OF THE INITIAL PRECIPITATION WILL BE WEST OF THE AREA TUESDAY EVENING AND THEN SLIDE OVER THE AREA TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY NIGHT AS THE SURFACE LOW/TROUGH SLIDES FROM THE DAKOTAS INTO SOUTHWEST WISCONSIN. THE WARM AIR ADVECTION IS FAIRLY BROAD AND WEAK...SO WOULD EXPECT THE PRECIPITATION TO BE GENERAL LIGHT SHOWERS. WITH THE BEST FORCING FOCUSED OVER WISCONSIN AND THE SOUTHERN HALF OF THE CWA...HAVE THE HIGHEST POPS IN THAT AREA. SINCE THE BULK OF THE FORCING IS SOUTH OF THE AREA...WILL KEEP POPS IN THE HIGH CHANCE CATEGORY SINCE IT IS ENTIRELY POSSIBLE MUCH OF THE RAIN STAYS IN WISCONSIN. THUNDER CHANCES ARE LIMITED TO NON-EXISTANT...AS SHOWALTER VALUES ARE WELL ABOVE ZERO AND MUCAPE VALUES STAY BELOW 100 J/KG DURING THIS PERIOD. EXPECT A DIMINISHING TREND IN THE PRECIPITATION FOR THURSDAY INTO THURSDAY NIGHT...AS THE DISTURBANCE SHIFTS EAST AND HIGH PRESSURE NEAR HUDSON BAY PUSHES DRIER AIR INTO THE AREA. THIS SHOULD LEAD TO DRY WEATHER FOR FRIDAY...BUT ANOTHER WEAK SHORTWAVE TRIES TO SLIDE EAST ACROSS THE AREA FOR SATURDAY. WITH THE DRY EASTERLY FLOW AND THE POTENTIAL THE HIGH REMAINS IN PLACE...IT/S ARRIVAL MAY BE DELAYED SOME. TEMPERATURES FROM MID WEEK ON WILL CONTINUE THE BELOW NORMAL TREND...WITH HIGHS GENERALLY IN THE 50S-60S AND THE COOLEST DAY ON WEDNESDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 723 PM EDT SAT JUN 1 2013 EXPECT IFR CONDITIONS THIS EVNG ASSOCIATED WITH AN INFLUX OF SHALLOW COOL...MOIST AIR ON THE HEELS OF GUSTY N WINDS TO IMPROVE TO MVFR NW-SE LATE TNGT AS DRIER AIR FOLLOWS INTO THE AREA AHEAD OF HI PRES BLDG TOWARD UPR MI. AS THIS HI MOVES OVHD ON SUN...CONDITIONS WL IMPROVE TO VFR...AND THE GUSTY WINDS WL DIMINISH. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 520 AM EDT SUN JUN 2 2013 LOW PRESSURE OVER GEORGIAN BAY WILL SHIFT ENE INTO QUEBEC BY THIS AFTERNOON...WHILE A RIDGE OF HIGH PRESSURE BUILDS OVER NORTHERN ONTARIO. AS A RESULT...NORTH WINDS WILL DIMINISH TODAY. RIDGING WILL EXTEND OVER LAKE SUPERIOR TONIGHT...WHICH WILL REMAIN THROUGH MUCH WEDNESDAY AS THE NEXT LOW WILL SLIDES ACROSS THE NORTHERN PLAINS. THE LOW WILL SHIFT SLOWLY E INTO THE MID MS VALLEY THURSDAY...WHILE THE WEAK RIDGE OF HIGH PRESSURE LINGERS OVER LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FROST ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 8 AM EDT /7 AM CDT/ MONDAY FOR MIZ002-004-005-009>011-084. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...KC MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
451 AM CDT SUN JUN 2 2013 .UPDATED FOR 12Z AVIATION DISCUSSION... ISSUED AT 441 AM CDT SUN JUN 2 2013 && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM CDT SUN JUN 2 2013 EARLY MORNING SURFACE ANALYSIS REVEALED A BROAD RIDGE OF HIGH PRESSURE ACROSS THE DAKOTAS. THIS HIGH WAS LOCATED BENEATH AN UPPER LEVEL RIDGE LOCATED JUST UPSTREAM OVER EASTERN MONTANA. OVER THE NEXT 24 HOURS THIS HIGH WILL SLOWLY MIGRATE EASTWARD BRINGING SOME MUCH ANTICIPATED DRY WEATHER. HOWEVER...AFTERNOON TEMPERATURES WILL REMAIN COOL AS H850 TEMPS LINGER IN THE 2 TO 4C RANGE. BOTH THE RAP AND NAM BUFR SOUNDINGS SHOW MIXING UP TO AROUND 800MB WITH SATURATION AT THE TOP OF THE BOUNDARY LAYER. THEREFORE USED THE MIXDOWN TOOL FOR HIGH TEMPERATURES THIS AFTERNOON. ALSO INCLUDED SOME AFTERNOON CLOUDS ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA IN ANTICIPATION OF SOME FLAT CU DURING PEAK HEATING. THESE CLOUDS WILL QUICKLY DISSIPATE AFTER SUNSET SETTING THE STAGE FOR RADIATIONAL COOLING AND ANOTHER CHILLY NIGHT ACROSS THE REGION. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 342 AM CDT SUN JUN 2 2013 NORTHWEST UPPER FLOW WILL PREDOMINATE THROUGH THE PERIOD... KEEPING THINGS A BIT COOL ACROSS OUR AREA WITH NO REAL SEVERE WEATHER CONCERNS. THERE ARE CERTAINLY SOME DIFFERENCES IN THE DETAILS BETWEEN THE ECMWF AND GFS AND THEIR RESPECTIVE ENSEMBLES... BUT IN GENERAL THERE IS GOOD AGREEMENT ON THE EVOLUTION OF THE LARGE SCALE PATTERN THROUGH THE WEEK. ONE UPPER WAVE WILL SLOWLY MIGRATE ACROSS THE AREA TUESDAY AND WEDNESDAY... WITH WEAK RIDGING FOR THURSDAY INTO EARLY FRIDAY... THEN AN UPPER WAVE WILL SLOWLY WORK IN FROM THE NORTHERN PLAINS AS WE MOVE INTO THE UPCOMING WEEKEND. ALLOWED FOR SOME LOW POPS TO WORK INTO THE WESTERN PART OF THE FORECAST AREA ON MONDAY AS WE GET ON THE BACKSIDE OF THE SURFACE RIDGE AND START TO SEE SOME WARM ADVECTION DEVELOP OVER THE WESTERN PART OF THE AREA. CHANCES FOR PCPN WILL THEN SPREAD EASTWARD MONDAY NIGHT THROUGH TUESDAY AS A SURFACE LOW NEAR THE NORTHERN END OF AN INVERTED TROUGH WORKS ITS WAY FROM THE DAKOTAS ACROSS MICHIGAN. A LOOK AT 850-500MB DIFFERENTIAL THETA-E AND BEST LIFTED INDICES SHOWS ELEVATED INSTABILITY SLIGHTLY LAGGING THE INITIAL WARM ADVECTION AND MOISTURE RETURN... SO SHOULD SEE SHOWER CHANCES AT FIRST GIVE WAY TO THE CHANCE FOR SHOWERS WILL SOME EMBEDDED THUNDER. SEVERE WEATHER THREAT LOOKS LOW THROUGH THE WEEK GIVEN GENERALLY MEAGER INSTABILITY UP INTO OUR AREA... WITH THE MAIN BAROCLINIC ZONE REMAINING WELL TO THE SOUTH. HOWEVER... THERE IS VERY STRONG DEEP LAYER SHEAR MIGRATING ACROSS ON TUESDAY AHEAD OF THE AFOREMENTIONED SURFACE LOW... SO SHOULD INSTABILITY MANAGE TO BE BETTER THAN THE FEW HUNDRED J/KG ADVERTISED BY THE NAM AND GFS THEN THERE COULD BE SOME CONCERNS. HOWEVER... THE BETTER SHEAR... BOTH LOW-LEVEL AND DEEP LAYER... LOOKS LIKE IT WILL OUTPACE WHERE THE BETTER INSTABILITY WILL OCCUR ON TUESDAY... WHICH SHOULD FURTHER MITIGATE ANY POTENTIAL. MAIN CONCERN IF INSTABILITY WERE CLOSER TO 500 J/KG AND BETTER ALIGNED WITH SHEAR WOULD BE LOW-TOPPED SUPERCELL POTENTIAL... BUT AT THIS POINT THINGS DON/T APPEAR TO BE COMING TOGETHER TOO WELL FOR THAT. PCPN CHANCES WILL LINGER ACROSS THE AREA TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER WAVE AND FILLING SURFACE LOW SLIDE ACROSS THE AREA. A BIT OF A BACKDOOR COLD FRONT AND RIDGE OF HIGH PRESSURE WILL WORK INTO THE AREA THURSDAY INTO FRIDAY... WHICH SHOULD BRIEFLY REDUCE CHANCES FOR ANY PCPN OVER THE AREA. HOWEVER... GIVEN THE ADVERTISED COOL 700-500MB TEMPERATURES AND POTENTIAL FOR DECENT LAPSE RATES WITH ANY SUNSHINE... WE COULD CERTAINLY WIND UP WITH SOME SHRA IF THERE ISN/T SUFFICIENT RIDGING AND LOW LEVEL SUBSIDENCE. SO... WENT WITH LOWER OR NO POPS THURSDAY AND FRIDAY FARTHER NORTH WHERE RIDGING LOOKS LIKE IT SHOULD BE MORE PREVALENT... BUT KEPT SLIGHTLY HIGHER CHANCES FARTHER SOUTH. DIDN/T INCLUDE ANYTHING FOR THURSDAY NIGHT... SINCE IT SEEMS ANY POTENTIAL WOULD BE DIURNALLY DRIVEN. BY SATURDAY... WE MAY SEE CHANCES FOR MORE WIDESPREAD PCPN START TO WORK IN FROM THE WEST AS WE ONCE AGAIN GET ONTO THE BACKSIDE OF THE SURFACE HIGH AND START TO SEE SOME WARM ADVECTION AND MOISTURE RETURN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 441 AM CDT SUN JUN 2 2013 MVFR STRATUS DECK HAS BEEN SLOW TO EXIT THE REGION...BUT SHOULD CONTINUE TO SEE IT PUSH EASTWARD THIS MORNING. ONCE CONDITIONS BECOME VFR...EXPECT THEM TO STAY THAT WAY THROUGH THE REST OF THE PERIOD. A FEW AFTERNOON CLOUDS WILL DEVELOP ACROSS THE EAST...BUT THEY WILL BE VFR. NNW WINDS WILL GO CALM OVERNIGHT...AND BECOME SOUTHEASTERLY ACROSS WESTERN MINNESOTA BY MONDAY MORNING. KMSP... VFR CONDITIONS THROUGHOUT. CLOUDS ARE BEGINNING TO BREAK UP...WITH CLEAR SKIES ACROSS THE NORTH. SHOULD SEE SOME AFTERNOON CLOUDS AT OR ABOVE 4500FT THIS AFTERNOON. WINDS WILL GO CALM OVERNIGHT AND BE SOUTHEASTERLY BY MID MORNING ON MONDAY. /OUTLOOK FOR KMSP/ MON...VFR WITH -SHRA LATE. WINDS SE AT 10KTS. TUE...MVFR WITH -SHRA/TSRA LIKELY. WINDS ESE AT 10G20KTS. WED...VFR WITH MVFR/TSRA POSSIBLE. WINDS NNE AT 10KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB LONG TERM... AVIATION...JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
359 AM CDT SUN JUN 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM CDT SUN JUN 2 2013 EARLY MORNING SURFACE ANALYSIS REVEALED A BROAD RIDGE OF HIGH PRESSURE ACROSS THE DAKOTAS. THIS HIGH WAS LOCATED BENEATH AN UPPER LEVEL RIDGE LOCATED JUST UPSTREAM OVER EASTERN MONTANA. OVER THE NEXT 24 HOURS THIS HIGH WILL SLOWLY MIGRATE EASTWARD BRINGING SOME MUCH ANTICIPATED DRY WEATHER. HOWEVER...AFTERNOON TEMPERATURES WILL REMAIN COOL AS H850 TEMPS LINGER IN THE 2 TO 4C RANGE. BOTH THE RAP AND NAM BUFR SOUNDINGS SHOW MIXING UP TO AROUND 800MB WITH SATURATION AT THE TOP OF THE BOUNDARY LAYER. THEREFORE USED THE MIXDOWN TOOL FOR HIGH TEMPERATURES THIS AFTERNOON. ALSO INCLUDED SOME AFTERNOON CLOUDS ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA IN ANTICIPATION OF SOME FLAT CU DURING PEAK HEATING. THESE CLOUDS WILL QUICKLY DISSIPATE AFTER SUNSET SETTING THE STAGE FOR RADIATIONAL COOLING AND ANOTHER CHILLY NIGHT ACROSS THE REGION. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 342 AM CDT SUN JUN 2 2013 NORTHWEST UPPER FLOW WILL PREDOMINATE THROUGH THE PERIOD... KEEPING THINGS A BIT COOL ACROSS OUR AREA WITH NO REAL SEVERE WEATHER CONCERNS. THERE ARE CERTAINLY SOME DIFFERENCES IN THE DETAILS BETWEEN THE ECMWF AND GFS AND THEIR RESPECTIVE ENSEMBLES... BUT IN GENERAL THERE IS GOOD AGREEMENT ON THE EVOLUTION OF THE LARGE SCALE PATTERN THROUGH THE WEEK. ONE UPPER WAVE WILL SLOWLY MIGRATE ACROSS THE AREA TUESDAY AND WEDNESDAY... WITH WEAK RIDGING FOR THURSDAY INTO EARLY FRIDAY... THEN AN UPPER WAVE WILL SLOWLY WORK IN FROM THE NORTHERN PLAINS AS WE MOVE INTO THE UPCOMING WEEKEND. ALLOWED FOR SOME LOW POPS TO WORK INTO THE WESTERN PART OF THE FORECAST AREA ON MONDAY AS WE GET ON THE BACKSIDE OF THE SURFACE RIDGE AND START TO SEE SOME WARM ADVECTION DEVELOP OVER THE WESTERN PART OF THE AREA. CHANCES FOR PCPN WILL THEN SPREAD EASTWARD MONDAY NIGHT THROUGH TUESDAY AS A SURFACE LOW NEAR THE NORTHERN END OF AN INVERTED TROUGH WORKS ITS WAY FROM THE DAKOTAS ACROSS MICHIGAN. A LOOK AT 850-500MB DIFFERENTIAL THETA-E AND BEST LIFTED INDICES SHOWS ELEVATED INSTABILITY SLIGHTLY LAGGING THE INITIAL WARM ADVECTION AND MOISTURE RETURN... SO SHOULD SEE SHOWER CHANCES AT FIRST GIVE WAY TO THE CHANCE FOR SHOWERS WILL SOME EMBEDDED THUNDER. SEVERE WEATHER THREAT LOOKS LOW THROUGH THE WEEK GIVEN GENERALLY MEAGER INSTABILITY UP INTO OUR AREA... WITH THE MAIN BAROCLINIC ZONE REMAINING WELL TO THE SOUTH. HOWEVER... THERE IS VERY STRONG DEEP LAYER SHEAR MIGRATING ACROSS ON TUESDAY AHEAD OF THE AFOREMENTIONED SURFACE LOW... SO SHOULD INSTABILITY MANAGE TO BE BETTER THAN THE FEW HUNDRED J/KG ADVERTISED BY THE NAM AND GFS THEN THERE COULD BE SOME CONCERNS. HOWEVER... THE BETTER SHEAR... BOTH LOW-LEVEL AND DEEP LAYER... LOOKS LIKE IT WILL OUTPACE WHERE THE BETTER INSTABILITY WILL OCCUR ON TUESDAY... WHICH SHOULD FURTHER MITIGATE ANY POTENTIAL. MAIN CONCERN IF INSTABILITY WERE CLOSER TO 500 J/KG AND BETTER ALIGNED WITH SHEAR WOULD BE LOW-TOPPED SUPERCELL POTENTIAL... BUT AT THIS POINT THINGS DON/T APPEAR TO BE COMING TOGETHER TOO WELL FOR THAT. PCPN CHANCES WILL LINGER ACROSS THE AREA TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER WAVE AND FILLING SURFACE LOW SLIDE ACROSS THE AREA. A BIT OF A BACKDOOR COLD FRONT AND RIDGE OF HIGH PRESSURE WILL WORK INTO THE AREA THURSDAY INTO FRIDAY... WHICH SHOULD BRIEFLY REDUCE CHANCES FOR ANY PCPN OVER THE AREA. HOWEVER... GIVEN THE ADVERTISED COOL 700-500MB TEMPERATURES AND POTENTIAL FOR DECENT LAPSE RATES WITH ANY SUNSHINE... WE COULD CERTAINLY WIND UP WITH SOME SHRA IF THERE ISN/T SUFFICIENT RIDGING AND LOW LEVEL SUBSIDENCE. SO... WENT WITH LOWER OR NO POPS THURSDAY AND FRIDAY FARTHER NORTH WHERE RIDGING LOOKS LIKE IT SHOULD BE MORE PREVALENT... BUT KEPT SLIGHTLY HIGHER CHANCES FARTHER SOUTH. DIDN/T INCLUDE ANYTHING FOR THURSDAY NIGHT... SINCE IT SEEMS ANY POTENTIAL WOULD BE DIURNALLY DRIVEN. BY SATURDAY... WE MAY SEE CHANCES FOR MORE WIDESPREAD PCPN START TO WORK IN FROM THE WEST AS WE ONCE AGAIN GET ONTO THE BACKSIDE OF THE SURFACE HIGH AND START TO SEE SOME WARM ADVECTION AND MOISTURE RETURN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1136 PM CDT SAT JUN 1 2013 CIGS ARE IMPROVING AREAWIDE AS DRIER BEGINS TO FILTER IN. SHOULD SEE AN IMPROVEMENT TO VFR FROM CNTRL MN SOUTHEASTWARD INTO WRN WI OVERNIGHT. VFR EXPECTED THEN FOR THE REMAINDER OF THE TAF CYCLE. KMSP...CONDS AT TAF ISSUANCE TIME ARE VARYING FROM MVFR TO VFR. UPSTREAM OBS INDICATE VFR CIGS...SO EXPECT CONDS TO IMPROVE TO VFR QUICKLY AFTER TAF PERIOD BEGINS. WINDS WILL REMAIN NORTHWEST AROUND 10 KTS THRU SUNDAY...THEN DIMINISH SUNDAY EVENING. /OUTLOOK FOR KMSP/ MON...VFR WITH -SHRA POSSIBLE LATE. WINDS SE AT 10KTS. TUE...MVFR WITH TSRA LIKELY. WINDS SE AT 10-15G20KTS. WED...VFR WITH MVFR/TSRA POSSIBLE. WINDS NE 5 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB LONG TERM... AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
302 AM CDT SUN JUN 2 2013 .DISCUSSION... MAIN FORECAST CHALLENGE WAS WHEN TO INCLUDE TSTM CHANCES AS ANOTHER UPPER TROUGH/LOW MOVES FROM SWRN CANADA ACROSS NORTHERN PLAINS THROUGH MIDWEEK. FOR TODAY...UPPER RIDGE AHEAD OF SWRN CANADIAN LOW TO FLATTEN AS IT BUILDS ACROSS CNTRL PLAINS AS UPPER LOW SOUTH OF HUDSONS BAY DROPS SOUTH. PERSISTENT LOW CLOUDS HAVE CLEARED WRN ZONES AS OF 730Z AND SHOULD CONTINUE TO DO SO THROUGH THIS MORNING...ALTHOUGH LATEST RAP SOUNDING DELAYED THIS CLEARING ALONG/E OF MO RIVER TILL AFTERNOON. SLOWED CLEARING DOWN A BIT E...AND FURTHER ADJUSTMENTS MAY BE NEEDED. MILDER TEMPS COMPARED TO SATURDAY BUT STILL BELOW NORMAL AND GENERALLY A DEG OR TWO BELOW GUIDANCE BASED ON PERHAPS HINDERED MIXING FROM MORNING/EARLY AFTN CLOUDS E AND/OR SLIGHTLY COOLER H85 TEMPS PER 00Z ECMWF. UPPER LOW MOVING TOWARD DAKOTAS LATE MONDAY WILL STRENGTHEN LOW LEVEL JET LATE TONIGHT INTO MONDAY NIGHT. THIS WILL PROVIDE INCREASING WINDS...ESPECIALLY MONDAY. HOWEVER...WINDS PROBABLY WILL NOT INCREASE QUICKLY ENOUGH TONIGHT TO HELP LOWS MUCH WITH GUIDANCE GENERALLY ACCEPTABLE. STORMS THAT DEVELOP TO OUR WEST LATE TONIGHT AIDED BY THETA E ADVECTION IN LOW LEVEL JET AXIS COULD MOVE ACROSS SECTIONS OF THE AREA MONDAY MORNING...FOR NOW CONFINED SLGT CHC POPS TO FAR N. OTHERWISE KEPT MONDAY AFTN DRY. BOOSTED WIND SPEEDS MONDAY TO JUST BELOW WIND ADVISORY CRITERIA NWRN ZONES. MAX TEMPERATURES PROBABLY A CATEGORY OR SO WARMER MOST AREAS LOOKS FINE. INCREASING POPS MONDAY NIGHT INTO TUESDAY STILL ON TRACK AS UPPER LOW SHIFTS SE A BIT AND LOW LEVEL JET/CONVERGENCE SHIFTS INTO THE FORECAST AREA MONDAY NIGHT FOLLOWED BY A COLD FRONT TUESDAY. ALTHOUGH SOME ADJUSTMENTS WERE MADE AND MORE WILL PROBABLY BE ADDRESSED IN LATER FORECASTS...IT APPEARS HIGHER POPS WILL BE SHIFTING TOWARD ERN ZONES THRU LATE TUESDAY. IF CLOUDS/SHOWERS REMAIN WIDESPREAD TUE MAX TEMPS MAY NEED LOWERING. CONFIDENCE IS LOW IN HOW SCENARIO TUE NIGHT/WED PLAYS OUT AS A WAVE ROTATING AROUND UPPER LOW COULD HELP GENERATE MCS TO OUR WSW IN UPSLOPE REGION ACROSS WRN HIGH PLAINS BY WED AM. SOME OF THIS ACTIVITY COULD SKIRT AREA WED...SPCLY SOUTH...AND LOW CHC POPS WERE CARRIED GENERALLY ALONG/S OF HIGHWAY 30. HOWEVER...WE COULD ALSO SEE JUST MAINLY CLOUDS FROM THIS...BUT EITHER PRECIP OR CLOUDS COULD IMPACT HIGHS. FOR NOW THEY WERE KEPT IN THE 70S TUE AND WED. THURSDAY LOOKED DRY WITH INCREASING TSTM CHANCES AGAIN FROM W TO E FRIDAY INTO SATURDAY AS NEXT TROUGH APPROACHES. NO CHANGES MADE FROM MODEL/PREVIOUS FORECAST BLEND. CHERMOK && .AVIATION... 06Z TAFS FOR KOMA...KLNK AND KOFK. MVFR OR SLIGHTLY HIGHER CEILINGS AT KOMA AND KLNK SHOULD SCATTER OUT BY 10Z-12Z AT KLNK AND AROUND 12Z-14Z AT KOMA...WITH VFR CONDITIONS BEYOND THEN. NORTHWEST WINDS BECOMING NORTH THROUGH THE DAY...THEN LIGHT AND VARIABLE AND BECOMING SOUTHEAST TOWARD THE END OF THE TAF PERIOD. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1223 AM CDT SUN JUN 2 2013 .UPDATE... ISSUED AT 710 PM CDT SAT JUN 1 2013 ONLY MADE A FEW FAIRLY MINOR TWEAKS TO THE FORECAST FOR THE EARLY EVENING UPDATE. FIRST OF ALL...SLIGHTLY SLOWED THE DECREASE IN WIND SPEEDS THIS EVENING...AS MANY SITES CONTINUE TO REPORT SUSTAINED SPEEDS OF 20+ MPH...AND IT LOOKS LIKE SUSTAINED SPEEDS TO AROUND 15 MPH MAY STILL BE PRESENT ACROSS MUCH OF THE EASTERN 1/2 OF THE CWA EVEN AT 10 PM WITH LOWER VALUES IN THE WEST...ALTHOUGH ALL AREAS SHOULD LEGITIMATELY SETTLE TO AROUND/UNDER 10 MPH BY MIDNIGHT OR SO AS HIGH PRESSURE CONTINUES BUILDING IN. GIVEN THAT SUSTAINED SPEEDS ARE ALREADY SAFELY UNDER 30 MPH IN ALL AREAS...WILL BE REMOVING WIND WORDING FROM THE HAZARDOUS WEATHER OUTLOOK...RESULTING IN NO HAZARD MENTION FOR THE REST OF THE NIGHT AS THE REGION CONTINUES ITS FAIRLY BRIEF RESPITE FROM THUNDERSTORM ACTIVITY. THE OTHER TRICKY ISSUE FOR THE OVERNIGHT HOURS WILL BE THE FATE OF THE LOW STRATUS DECK GENERALLY IN THE 3000-5000 FT RANGE. CURRENT EXPECTATION IS FOR A STEADY EROSION OF THIS STRATUS FROM WEST TO EAST AS THE EVENING GOES ON...MUCH IN LINE WITH CURRENT FORECAST. HOWEVER...WILL HAVE TO SEE IF THE 21Z RAP MAY BE ONTO SOMETHING WITH ITS 900 MILLIBAR RELATIVE HUMIDITY FIELD...AS IT SUGGESTS THAT QUITE A BIT OF LOW CLOUD COVER COULD HANG ON OR MOVE BACK INTO PRIMARILY THE EASTERN 1/2 OF THE CWA TONIGHT...WHICH COULD OBVIOUSLY HAVE AT LEAST A SLIGHT IMPACT ON OVERNIGHT LOW TEMPS. NO CHANGES MADE TO LOW TEMPS AT THIS TIME...WHICH ARE STILL LOOKING TO AVERAGE AROUND 10 DEGREES BELOW NORMAL IN THE LOW-MID 40S FOR MUCH OF THE CWA. HOWEVER...PLEASE NOTE THAT FORECAST LOWS FOR OUR PRIMARY CLIMATE SITES GRAND ISLAND/HASTINGS ARE STILL 5 DEGREES ABOVE RECORD LOWS FOR JUNE 2ND...WHICH FOR GRAND ISLAND IS 39 IN 1964...AND HASTINGS IS 40 IN 1964/1951. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 247 PM CDT SAT JUN 1 2013 UPPER AIR PROFILER AND SATELLITE DATA THIS AFTERNOON SHOWING THE MAIN TROUGH AXIS CONTINUING TO GRADUALLY MAKE ITS WAY EAST/SOUTHEAST THROUGH THE PLAINS...WITH NORTHWESTERLY FLOW BUILDING IN BEHIND. AS EXPECTED...THIS DISTURBANCE BROUGHT A FEW SPRINKLES TO THE AREA /MAINLY THIS MORNING/...AND HAS KEPT PLENTY OF CLOUD COVER AROUND THROUGH THE DAY. HAS ALSO BEEN A BREEZY/WINDY DAY...WHILE SURFACE LOW PRESSURE OVER MN/WI HAS BEEN SLOW TO SHIFT EAST...HIGH PRESSURE HAS CONTINUED TO BUILD IN FROM THE WEST BEHIND THE MAIN FRONT. THIS TIGHTENED PRESSURE GRADIENT RESULTED IN SUSTAINED WINDS OF 20 TO 30 MPH...AND AT TIMES GUSTS IN THE 40 MPH AREA. DID HAVE SOME SITES ON OCCASION HITTING WIND ADV CRITERIA. THROUGH THE REST OF THE SHORT TERM PERIOD...THE FORECAST REMAINS DRY. MODELS REMAIN IN GOOD AGREEMENT IN THE UPPER LEVELS...SHOWING BROAD RIDGING SETTING UP OVER THE ROCKIES/PLAINS...BETWEEN AREAS OF LOW PRESSURE LOCATED OVER ONTARIO AND THE ID/MONT/CANADIAN BORDER REGION. THIS WILL KEEP ANY PRECIPITATION CHANCES WELL OUT OF THE CWA...AND HELP MAKE FOR A VERY PLEASANT SUNDAY. AT THE SURFACE...THE PATTERN THROUGH THE SHORT TERM WILL BE DOMINATED BY HIGH PRESSURE. THIS FEATURE WILL CONTINUE TO BUILD IN FROM THE WEST TONIGHT...AND THERE IS A LITTLE UNCERTAINTY WITH JUST HOW FAR EAST THE RIDGE AXIS WILL GET. THE NAM IS ON THE FURTHEST EAST SIDE OF THINGS...SHOWING THE RIDGE AXIS ACTUALLY THROUGH THE CWA BY 12Z SUNDAY...WITH MOST OF THE SUPPORT SHOWING THE RIDGE AXIS STAYING JUST TO/SET UP OVER THE WRN FRINGE OF THE CWA. WINDS WILL BE DIMINISHING WITH TIME...BUT DEPENDING ON WHERE THE RIDGE SETS UP WILL DETERMINE WHETHER WINDS BECOME CALM...AND COULD AFFECT LOW TEMPERATURES TONIGHT. STAYED FAIRLY CLOSE TO GUIDANCE FOR LOWS...WHICH BRING LOWER/MID 40S TO THE CWA. IF THE WINDS STAY UP...THIS MAY BE TOO COOL. SUNDAY...SHOULD SEE PLENTY OF SUNSHINE ACROSS THE AREA...WITH THE SURFACE HIGH KEEPING WINDS LIGHT. SHOULD START TO SEE AN INCREASE IN TEMPS ALOFT STARTING TO SHIFT IN FROM THE WEST...AND HIGHS ARE EXPECTED TO REACH INTO THE LOWER/MID 70S /COMBINED WITH DEWPOINTS ONLY IN THE 40S/. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 247 PM CDT SAT JUN 1 2013 AS SFC RIDGE CONTINUES TO DEPART TO THE EAST AND SFC LOW DEEPENS ALONG THE HIGH PLAINS...SOUTHERLY LLVL FLOW INCREASES SUNDAY NIGHT. THE LLVL JET STRENGTHENS TO NEAR 50KTS AND IN INCREASING SOUTHERLY FLOW...MOISTURE AGAIN IS DRAWN NORTH INTO THE PLAINS STATES SUNDAY NIGHT/MONDAY. WARM FRONT LIFTS NORTHEAST ON MONDAY AND TEMPS WILL TREND WARMER...CLOSER TO SEASONAL READINGS IN THE UPPER 70S/LOW 80S. MONDAY WILL NOT BE WITHOUT WIND HOWEVER AS SFC GRADIENT REMAINS TIGHT AND FORECAST SOUNDINGS SUGGEST MIXING TO AT LEAST H8. WINDS DO NOT APPEAR TO REACH WIND ADV CRITERIA JUST YET...BUT WILL NEED TO MONITOR. DURING THE DAY ON MONDAY SHOULD REMAIN DRY...HOWEVER DID HOLD ONTO SOME LOW POPS IN THE WAA REGIME...BUT GENERALLY EXPECT CAPPING TO HOLD IN THE EAST DURING THE AFTN WHILE BETTER CONVECTIVE POTENTIAL/INITIATION FOCUSES TO THE WEST ALONG THE HIGH PLAINS ALONG SFC TROUGH/DRYLINE EDGING INTO SW NEB/WESTERN KANSAS...AND TO THE NW ALONG SFC TROUGH/COOL FRONTAL BOUNDARY. CONVECTION IS THEN EXPECTED TO PUSH SOUTH AND EASTWARD MONDAY NIGHT AS THE NORTHERN BOUNDARY REACHES CENTRAL NEBRASKA AHEAD OF THE UPPER TROUGH IN THE DAKOTAS. AN INSTABILITY AXIS OF 2000 TO 2500 J/KG WILL REACH CENTRAL NEB MONDAY NIGHT WITH SHEAR OF 30 TO 40KTS...AND SEVERE STORMS ARE POSSIBLE IN THIS ENVIRONMENT MONDAY NIGHT...WITH HAIL/WIND PRIMARY HAZARDS FOR THE MAINLY NOCTURNAL CONVECTION. TUESDAY MAY SEE ONGOING CONVECTION IN THE MORNING WITH OUTFLOW BOUNDARY AND/OR SFC WARM FRONTAL BOUNDARY POTENTIALLY STALLING OUT...BUT THIS WILL BE DEPENDENT ON CONVECTION MONDAY NIGHT. MOISTURE POOLS ALONG THE BOUNDARY ON TUESDAY WITH SREF INDICATING INSTABILITY OF 3000 TO 4000 J/KG ACROSS NORTH CENTRAL KS WITH INSTABILITY AXIS EXTENDING INTO SC NEB...WITH SHEAR ON THE ORDER OF 40KTS. IF BOUNDARY POSITION IS CLOSE/ACROSS OUR CWA...STORMS ARE EXPECTED TO INITIATE ACROSS OUR AREA TUESDAY AFTN/EVE IN VCNTY OF BOUNDARY WITH SEVERE STORMS AGAIN LIKELY. SETUP WOULD BE FAVORABLE FOR LARGE HAIL/DAMAGING WINDS/TORNADOES NEAR THE BOUNDARY...AND HEAVY RAINFALL. ADDITIONAL CONVECTIVE DEVELOPMENT IS POSSIBLE ALONG THE HIGH PLAINS/DRY LINE AREA AND TO THE NW WITH APPROACHING TROUGH/SECONDARY COOL FRONT. BEYOND THIS TIME FRAME...TOO DIFFICULT TO TRY TO NAIL DOWN THE DETAILS AS BOUNDARY PLACEMENT WILL BE DEPENDENT UPON CONVECTION WHICH DEVELOPS EACH DAY/NIGHT. ON WEDNESDAY...FRONT MAY LINGER IN OUR SOUTHEAST ZONES...THEN BETTER CHCS FOR STORMS BEGIN TO SHIFT SE ALONG BOUNDARY WHILE THE UPPER SYSTEM/LOW REACHES THE UPPER MIDWEST. IN THEORY WE SHOULD SEE A LULL/BREAK IN CONVECTION POTENTIAL FOR A PERIOD OR TWO...THEN PATTERN LOOKS ACTIVE AGAIN HEADING INTO NEXT WEEKEND. FOR TEMPERATURES...IT IS NOT LOOKING OVERLY WARM OR COLD...WITH HIGHS DEPENDENT UPON WHICH SIDE OF BOUNDARY YOU ARE ON...BUT CLOSE TO SEASONAL NORMALS OVERALL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1213 AM CDT SUN JUN 2 2013 VFR CONDITIONS ARE FORECAST WITH LIGHT WIND THROUGHOUT THE FORECAST. SOME STRAGGLING STRATUS NEAR 3500 FT WILL HANG AROUND FOR PART OF THE OVERNIGHT...BUT WILL FINALLY CLEAR AS LOW PRESSURE CONTINUES TO HEAD EAST AND A SURFACE HIGH BUILDS IN. LIGHT NORTH WIND WILL BECOME LIGHT FROM THE SOUTH BY SUNDAY EVENING AS THE SURFACE HIGH CONTINUES EAST AND THE FIRST OF THE RETURN FLOW COMMENCES. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...PFANNKUCH SHORT TERM...ADO LONG TERM...FAY AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
153 AM EDT SUN JUN 2 2013 .SYNOPSIS... UPPER DISTURBANCE WITH CONVECTION INTO SUNDAY. COLD FRONT CROSSES SUNDAY NIGHT INTO MONDAY. COOLER AND DRIER TO START NEXT WEEK. WARM FRONT THURSDAY. && .NEAR TERM /THROUGH TODAY/... WITH LOSS OF SUNSHINE...LOW-LEVEL AIRMASS HAS BEGUN TO BECOME LESS UNSTABLE. THIS HAS BEEN SEEN IN THE STORMS IN OUR REGION DECREASING IN INTENSITY. HOWEVER...A LINE OF STORMS HAS DEVELOPED TO OUR WEST AND NORTHWEST. EXPECT THIS LINE WILL GRADUALLY MOVE EAST WITH TIME AND HAVE ADJUSTED ONSET OF LIKELY AND HIGHER POPS TO REFLECT THIS THINKING. OTHERWISE...ONLY TWEAKS MADE. PREVIOUS DISCUSSION... PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND SHOWERS/THUNDERSTORM CHANCES AS WELL AS POTENTIAL FOR SEVERE WEATHER. REGARDING THUNDERSTORMS THIS AFTERNOON/EVENING...15Z REGIONAL RADAR IMAGERY AND SFC OBS CONTINUE TO SHOW ONGOING WIDESPREAD PRECIP...MAINLY IN THE FORM OF SHOWERS...FROM WESTERN OHIO SW-WARD DOWN THE EXTENT OF THE OHIO RIVER INTO WESTERN TENN/ARKANSAS RESULTANT OF STRONG OVERNIGHT CONVECTION. SFC TEMPS IN WHAT APPEARED YESTERDAY TO BE THE FAVORED AREAS OF THUNDERSTORMS AND SUBSEQUENT SVR WX INITIATION STILL ONLY IN THE MID/UPPER 60S GENERALLY...WITH NO LIGHTNING STRIKES CURRENTLY. SHOULD PRECIP/CLOUDS HANG ON OVER THAT AREA...STRONGER STORMS MAY WAIT TO FORM FURTHER EAST OVER CENTRAL OHIO AND POINTS SOUTHWEST WHERE SFC TEMPS HAVE WARMED TO THE UPPER 70S/LOW 80S DESPITE FAIRLY DENSE HIGH CLOUD COVER. GOOD DYNAMICS ARRIVE BY 21Z WHICH CONTINUE INTO THE EVENING...PARTICULARLY OVER THE WESTERN ZONES WHERE 30-40KTS OF SHEAR IN PLACE. WITH THE FRONT STILL WELL TO THE WEST HOWEVER...TOUGH CALL ON DETERMINING A TRIGGERING MECHANISM. A VORT MAX PER LATEST RUC13 PROGGED TO PUSH NE-WARD THROUGH CENTRAL KY BY 21Z-00Z MAY BE ENOUGH TO GET THINGS GOING. DO FEEL THAT THUNDERSTORMS WILL SLOWLY BEGIN TO FORM BY THE MID/LATE AFTERNOON HOURS AT FIRST RELATIVELY UNORGANIZED...WITH A GRADUAL INCREASE FROM THE WEST BY AND AFTER 00Z SUN. AS USUAL...IT APPEARS TO BE A RACE BETWEEN STORM DEVELOPMENT AND LOSS OF DAYTIME PEAK INSTABILITY. BUT IN THE END...SOME STORMS MAY BECOME STRONG TO SEVERE MAINLY ACROSS THE FAR WESTERN ZONES CLOSER TO THE OHIO RIVER BUT THE THREAT APPEARS MARGINAL AT BEST. STRONG WINDS APPEAR TO BE THE MAIN HAZARD WITH DCAPE VALS OVER 1K J/KG JUST TO THE SOUTHWEST OF THE FORECAST AREA BUT EL/S ARE SUFFICIENTLY TALL FOR SOME LARGE HAIL. LITTLE CHANGE FROM PREV FORECAST WITH REGARD TO THE REMAINDER OF THE OVERNIGHT HOURS. A MORE GENERAL CONVECTIVE RAINFALL WITH SOME THUNDER PERHAPS WILL PUSH INTO THE AREA WITH GOOD DEEP LAYER MOISTURE AND A PREFRONTAL TROUGH-TYPE FEATURE. STILL EXPECTING ROUGHLY A HALF-INCH OR SO ACROSS THE AREA...AND SOME LOCALIZED WATER ISSUES COULD BE POSSIBLE SHOULD HEAVY SHOWERS/STORMS PASS OVER THE SAME LOCATION BUT NOTHING WIDESPREAD EXPECTED. SUNDAY...AGAIN LITTLE CHANGE FROM PREV FCST WITH THE MAIN AXIS OF DEEP MOISTURE PUSHING ACROSS DURING THE MORNING HOURS WITH HIGH CHANCE POPS CONFINED MAINLY TO CKB-CRW AND POINTS EAST BY 18Z. ACTUAL COLD FRONT HOWEVER STILL LAGS WELL BEHIND AND ONLY ENTERING THE NW ZONES BY END OF THE PERIOD. INHERITED MAX TEMPS AROUND 80 FOR LOWLANDS STILL LOOK ON TRACK. && .SHORT TERM /TONIGHT THROUGH TUESDAY/... GFS/ECMWF SHOW COLD FRONT OVER THE OH RIVER BY 00Z MONDAY. SHOWERS AND STORMS WILL BE POSSIBLE ALONG THE FRONT...DIMINISHING IN INTENSITY AND COVERAGE BY EARLY MONDAY MORNING. THE FRONT BRINGS A WIND SHIFT FROM THE NORTHWEST ALOFT MONDAY NIGHT...WHILE AT THE SFC COULD BECOME LIGHT AND VARIABLE...OR CALM. THEN...FLOW BECOMES NORTHERLY LATER MONDAY AND MONDAY NIGHT TO BRING COOLER TEMPERATURES...MILD AFTERNOON...AND RELATIVELY COLDER NIGHTS ARE EXPECTED THROUGH TUESDAY NIGHT. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... WEAK SEMI ZONAL FLOW ALOFT AND NO VORT MAX FROM SHORTWAVES SUGGEST BROAD HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH EARLY THURSDAY. THIS WILL CONTINUE TO CLEARING CONDITIONS...EXCEPT FOR LOW LEVEL DIURNAL CU DURING THE AFTERNOON HOURS. NEAR NORMAL TEMPERATURES EXPECTED THURSDAY ON. TWEAKED DOWN WPC TEMPERATURE A BIT. A WARM FRONTAL BOUNDARY FORMS ACROSS OH INTO SOUTHEAST OH THURSDAY...UNDER SOUTHERLY FLOW. THE SOUTHERLY WINDS WILL ALSO RESULT IN INCREASING LOW-LEVEL MOISTURE AND THE CHANCES FOR SHOWERS AND STORMS...MAINLY DIURNAL IN NATURE...WILL ALSO RETURN THROUGH THE REMAINDER OF THE PERIOD. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... 06Z SUNDAY THRU 06Z MONDAY... BAND OF ORGANIZED SHOWERS...WITH A FEW THUNDERSTORMS...WELL AHEAD OF A COLD FRONT WILL MOVE EASTWARD ACROSS THE AREA OVERNIGHT AND SUNDAY MORNING...REACHING THE I79 CORRIDOR BY 09Z...AND THE MOUNTAINS AROUND 12Z. EXPECT MOST OF THE CONVECTION WILL BE IN THE SOUTHERN AND CENTRAL MOUNTAINS BY 18Z...AND EXITING THE AREA BY 00Z MONDAY. VFR CONDITIONS WILL GENERALLY PREVAIL OUTSIDE OF THE RAIN...WITH GENERALLY MVFR CONDITIONS IN THE RAIN. AN EMBEDDED THUNDERSTORM IS POSSIBLE...SO WILL USE VCTS IN TAFS. BEHIND THE MAIN BAND OF CONVECTION...CANNOT RULE OUT A STRAY SHOWER OR STORM THIS AFTERNOON AND EVENING. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY... FORECAST CONFIDENCE...MEDIUM. ALTERNATE SCENARIOS: TIMING OF BAND OF CONVECTION AND MVFR CEILINGS MAY VARY BY 2 OR 3 HOURS. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE SUN 06/02/13 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H H H H H M M M M M M M HTS CONSISTENCY H H M M M M M M M M M M BKW CONSISTENCY H H H H H M M M M H H H EKN CONSISTENCY H H H H H M H H H H H H PKB CONSISTENCY H H H M H H H M M M H H CKB CONSISTENCY H H H H H M H H H M M M AFTER 06Z MONDAY... IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS SUNDAY NIGHT...AND IN POST-RAIN FOG LATER SUNDAY NIGHT INTO MONDAY MORNING. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...JMV/26 NEAR TERM...JSH/50 SHORT TERM...ARJ LONG TERM...ARJ AVIATION...JMV
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
136 AM EDT SUN JUN 2 2013 .SYNOPSIS... WEATHER SYSTEM OVER THE WESTERN GREAT LAKES WILL SHIFT EASTWARD TONIGHT...DRAGGING A COLD FRONT THROUGH THE OHIO VALLEY LATER TONIGHT AND SUNDAY. THIS WILL PROMPT SEVERAL ROUNDS OF SHOWERS AND STORMS FOR THE AREA...BEFORE A DRYING TREND TAKES HOLD FOR SUNDAY NIGHT...LASTING INTO THE MIDDLE OF NEXT WEEK. A COOLER AND DRIER AIRMASS WILL DOMINATE THROUGH THIS TIME PERIOD. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... STILL WORKING SOME DECENT UPDRAFTS NORTHEAST THROUGH SOUTH-CENTRAL OHIO AND NORTHEAST KENTUCKY. A FEW STORM SPLITS...LEFT MOVING HAIL CORES...AND PERSISTENT WEAK/BROAD ROTATION HAVE BEEN NOTED WITH THE STRONGEST STORMS /PROMPTED ONE QUICK WARNING/. THESE WILL CONTINUE TO WORK RATHER BRISKLY OFF TO THE NORTHEAST AND WHILE A ROGUE SMALL HAIL/WIND GUST IS POSSIBLE...THINK THESE HAVE WEAKENED IN A GENERAL SENSE FOR THE EVENING. ATTENTION THEN TURNS TO THE STRONGER SYNOPTIC FORCING ENTERING CNTL/ERN IL CURRENTLY WITH AN ATTENDANT COLD FRONT. RECENT HRRR RUNS SIMPLY ADAMANT A WHOLE BUNCH OF SHOWERS/STORMS WILL DEVELOP ACROSS EASTERN IND/WRN OHIO IN A FEW HOURS...AND DON/T WANT TO TOTALLY DISCOUNT THIS AS IT HAS BEEN ONE OF THE FEW STEADIER SIGNALS IN THE HRRR THE LAST FEW HOURS. BUT LAST GLIMPSES OF SATELLITE VIS PICS OVER IND SHOW THAT THE STABLE AIRMASS IS INTACT AND VERY FEW AGITATED CUMULUS/ACCAS ARE EVIDENT. THERE SHOULD BE A MODEST RAMP-UP OF THE LOW LEVEL JET IMMEDIATELY DOWNSTREAM OF THE PV ANOMALY ROTATING THROUGH IL RIGHT NOW SO THE SYNOPTIC SIGNALS SAY TO STAY THE COURSE WITH HIGHER RAIN/STORM CHANCES BEGINNING VERY LATE THIS EVENING. EARLY LOOK AT THE 02.00Z KILN BALLOON DATA SUGGESTS INSTBY IS NOT IMPRESSIVE BUT WINDS/SHEAR CONTINUE TO BE FAVORABLE FOR STORM ORGANIZATION. HOWEVER...SPC MESOA DATA SUGGESTING THE DCAPE POOL HAS BEEN MODIFIED SOME AND NOW THE NEAR SFC SHALLOW INVERSION HAS BEGUN TO FORM PER OBS. SO WHILE A FEW SEVERE REPORTS ARE POSSIBLE OVERNIGHT...JUST NOT SEEING A GREAT SETUP AND THUS WILL TONE BACK HAZ WX OUTLOOK FOR THE OVERNIGHT PERIOD. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/... SECONDARY WAVE ALOFT FINALLY ESCORTS THE TROUGH AXIS OUT OF THE AREA TOMORROW AND THIS ALLOWS A WEAK SECONDARY FRONT TO DEVELOP AND PUSH THROUGH DURING THE DAY. MAY BE A BROKEN BAND OF SHOWERS ALONG THIS FEATURE BY MID AFTERNOON...SO CARRIED THIS CHANCE FROM NW-SE ACROSS THE AREA DURING THE LATE MORNING INTO THE EARLY EVENING. MUCH COOLER/DRIER AIRMASS ARRIVES ON THE HEELS OF THIS FRONT AND MAKES FOR A COMFORTABLE SUNDAY NIGHT WITH LOWS DOWN INTO THE 50S UNDER CLEARING SKIES. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... PERIOD BEGINS WITH HIGH PRESSURE CENTERED OVER THE UPPER MS VALLEY. THE HIGH WILL BUILD SE INTO THE LOWER GREAT LAKES THROUGH TUESDAY. HIGHS ON MONDAY WILL BE COOL...RANGING FROM THE UPPER 60S TO THE LOWER 70S WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR EARLY JUNE. TEMPERATURES WILL FALL INTO THE UPPER 40S TO LOWER 50S MONDAY NIGHT. 12Z MODELS HAVE COME IN A LITTLE WARMER FOR TUESDAY. SO TOOK A CONSENSUS FORECAST AND RAISED HIGHS FOR TUESDAY INTO THE LOWER TO MID 70S. ON WEDNESDAY THE SFC HIGH PRESSURE IS FORECAST TO SLIDE EAST. THE ECMWF IS THE QUICKEST WITH THE RETURN PCPN...BUT THE REMAINING MODELS KEEP THE FA DRY...SO LEANED TOWARDS THE MAJORITY. WEDNESDAY NIGHT INTO THURSDAY AS WRMFNT DEVELOPS OVER THE OH VLY... ATMOSPHERE BECOMES UNTIL STABLE AND IT LOOKS LIKE THERE WILL BE A CHANCE OF SCT TSRA. THU NGT INTO FRI...H5 WAVE SWINGS UP THE OH VLY ADDING EXTRA LIFT AND IT DRIVES A CDFNT ACROSS THE REGION KEEPING CHC OF CONVECTION IN THE FORECAST. DRIER AIR TRIES TO BUILD IN FOR SATURDAY. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... BAND OF SHOWERS AND THUNDERSTORMS EXITING THE AREA TO THE EAST WILL LEAVE ALL TAF LOCATIONS DRY THROUGHOUT TONIGHT. A WEAK FRONTAL BOUNDARY APPROACHING FROM THE WEST WILL BRING A MIX OF VFR/MVFR CIGS TO THE AREA DURING THE EARLY MORNING. AFTER SUNRISE...CIGS WILL RISE TO VFR ACROSS THE AREA. DURING THE AFTERNOON...A SECONDARY COLD FRONT WILL PASS ACROSS THE AREA. THIS FRONT WILL BE ACCOMPANIED BY A BRIEF CHANCE FOR SHOWERS WITH WINDS SHIFTING FROM WESTERLY TO NORTHWESTERLY...GUSTING UP TO 25 KT. WINDS WILL SUBSIDE LATE THIS EVENING WITH CLEARING EXPECTED TO COMMENCE EARLY MONDAY MORNING. OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...BINAU NEAR TERM...BINAU SHORT TERM...BINAU LONG TERM...SITES AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
543 AM EDT SUN JUN 2 2013 .SYNOPSIS... WARM MOIST AIR OVER OUR REGION WILL BE DISPLACED BY A COLD FRONT TODAY. BEHIND THE FRONT AN UPPER TROUGH WILL DOMINATE OUR REGION WITH GENERALLY COOLER AND DRIER CONDITIONS PREVAILING THROUGH MID WEEK. WET WEATHER WILL RETURN FOR LATE WEEK AS A NEW WEATHER SYSTEM APPROACHES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A LINE OF CONVECTION CONTINUES TO MOVE ACROSS MY NW MOUNT IAN ZONES. THE MOST ORGANIZED ACTIVITY IS UP IN NY STATE...WITH THE LINE BECOMING PROGRESSIVELY MORE RAGGED LOOKING DOWN INTO SWRN PA. BIGGEST QUESTION FOR TODAY IS IF THE CONVECTION CAN ATTAIN ANY MEASURE OF ORGANIZATION AS THE FRONT ENTERS THE REGION. SPS HAS MUCH OF THE FCST AREA OUTLOOKED FOR A SLIGHT RISK OF SEVERE STORMS...BUT AS USUAL MUCH WILL DEPEND ON HEATING. SHORT RANGE HIGH RES GUIDANCE IS HAVING A HARD TIME GRASPING THE MODE OF CONVECTION THAT WE CAN EXPECT WITH THE FRONT. THE RAP SHOWS DISORGANIZED SHOWERS/STORMS WHILE THE HRRR HAS MORE OF A LINEAR LOOKING FEATURE DEVELOPING OVER CENTRAL PA BY MID MORNING...BUT CURIOUSLY WEAKENS THE LINE AS IT MOVES EAST DURING WHAT SHOULD BECOME THE MOST UNSTABLE PART OF THE DAY. THIS DOES A LOT TO LOWER CONFIDENCE IN TRYING TO TIME THE BEST CHANCES FOR RAIN AND STORMS TODAY. AS FOR POPS...I ENDED UP GOING WITH A GMOS/SREF COMPROMISE AND HAVE A LIKELY CHANCE OF SHOWERS AND THUNDER FOR MOST OF THE AREA THIS MORNING INTO THIS AFTERNOON...BUT TIMING IS TOUGH. IT WILL BE ANOTHER WARM MUGGY DAY WITH SLIGHTLY COOLER HIGH TEMPS DUE TO SHOWERS AND CLOUD COVER. THIS SHOULD BE THE LAST WIDESPREAD VERY WARM AND HUMID DAY FOR A WHILE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... STILL SOME UNCERTAINTY AMONG THE SHORT RANGE OPERATIONAL MODELS AS TO THE TIMING OF THE FRONT THRU SERN PA LATER TONIGHT INTO EARLY MONDAY. THE NAM IS THE SLOWEST WITH A WAVY FEATURE STILL STUCK OVER SERN PA INTO EARLY MONDAY...WHILE THE GFS AND ECMWF HAVE THE SURFACE FRONT ANYWHERE FROM THE CENTRAL DEL MARVA AREA TO NORTHERN NJ. THE GEFS AND SREF FOLLOW THEIR OPERATIONAL COUNTERPARTS PRETTY CLOSELY SO ONCE AGAIN I HAD TO SPLIT THE DIFFERENCE AND KEPT THE SMALL MENTION OF SHOWERS GOING INTO MONDAY MORNING. I DID DRY THINGS OUT THEREAFTER BUT THE 06Z NAM STILL LEANS TOWARD THE 00Z SOLUTION OF A SLOWER WAVY FRONT...SO LATER SHIFTS MAY HAVE TO ADJUST THIS A BIT. DRIER AND COOLER AIR WILL MOVE IN FROM THE NW OVERNIGHT AND MONDAY WITH THE LAST OF THE 60S DEWPOINTS BEING SHOVED OFF TO THE SE IN TIME. HOW FAST THEY EXIT THE REGION ALTOGETHER WILL DEPEND ON THE FRONT MENTIONED ABOVE. HIGHS MONDAY WILL BE IN THE CHILLY 60S OVER THE NW...WELL BELOW NORMAL FOR EARLY JUNE. HIGHS NEAR 80 IN THE SE WILL BE VERY NEAR NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE BUILDING DOWN OUT OF THE GR LAKES SHOULD PROVIDE FOR SOME DRY UNEVENTFUL WEATHER TUESDAY WITH PLEASANT TEMPS AND HUMIDITY. AS THE HIGH MOVES OFF TO OUR NORTHEAST WE SHOULD SET UP A SOUTHERLY FLOW OF INCREASING MOIST AIR. MEANWHILE THE MODELS WANT TO CARVE OUT A BROAD SLOW-MOVING UPPER TROUGH OVER THE EASTERN US SUGGESTING A PROLONGED PERIOD OF UNSETTLED WEATHER SETTING UP FROM ABOUT MID WEEK...POSSIBLY INTO NEXT WEEKEND. I REINTRODUCED THE CHANCES FOR RAIN BY WEDNESDAY AND KEPT THE MENTION OF SHOWERS RIGHT INTO SUNDAY. THE EXPECTED DEVELOPMENT OF A NEGATIVE NAO COULD SIGNAL THIS EASTERN TROUGH STICKING AROUND FOR A WHILE WITH THE GEFS SHOWING AN ANOMALOUS TROUGH DEVELOPING INTO THE LOWER GR LAKES OUT AS FAR AS DAY 7. OF NOTE IS SOME TROPICAL MOISTURE OVER THE BAY OF CAMPECHE. THE NHC SAYS IT HAS NO CHANCE OF TURING INTO A TROPICAL CYCLONE OVER THE NEXT COUPLE OF DAYS...BUT THE VARIOUS OPERATIONAL MODELS SEEM TO WANT TO DRAG AT LEAST SOME OF THE MOISTURE NORTHWARD. AS USUAL THERE IS NO AGREEMENT ON THE FINE DETAILS WITH THE GFS TAKING THE SLUG OF MOISTURE OFF THE SERN US COAST...THE ECMWF TAKING THINGS A FAIR DISTANCE UP THE COAST AND THE CANADIAN TAKING A FULL BLOWN TROPICAL CYCLONE INTO THE CENTRAL APPALACHIANS BY FRIDAY. COULD BE AN INTERESTING END OF THE WEEK. && .AVIATION /10Z SUNDAY THROUGH THURSDAY/... AS EXPECTED...SOME SHOWERS INTO BFD. ACTIVITY HAS WEAKEN...BUT A RUMBLE OF THUNDER STILL POSSIBLE. EARLIER DISCUSSION BELOW. BEST LLJ AND DYNAMICS LIFTING ACROSS THE LOWER LAKES AT THIS POINT. BFD WILL LIKELY SEE SOME SHOWERS AND EVEN A THUNDERSTORM OVERNIGHT. AREAS TO THE EAST WILL HAVE LESS CHANCE...AS SFC CONVERGENCE IS RATHER WEAK. HAVE TO WATCH SUNDAY NIGHT...AS FRONT SLOWS. HEAVY RAIN WILL BE POSSIBLE. IMPROVING CONDITIONS LATER MONDAY...AS EDGE OF VERY DRY AIR STARTS TO WORK INTO THE AREA. OUTLOOK... MON...LOW CIGS/FOG POSS EARLY OVR W MTNS. TUE-WED...NO SIG WX EXPECTED. THU...ISOLD PM THUNDERSTORM IMPACTS POSS W MTNS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
445 AM CDT SUN JUN 2 2013 .DISCUSSION... A LINE OF THUNDERSTORMS IS BEGINNING TO FILL IN FROM SOUTH OF LUFKIN TO COLLEGE STATION. RAIN GAUGES IN TRINITY COUNTY ARE PICKING UP AS MUCH AS 2.2 INCHES IN 3 HRS AND AS MUCH AS 2 INCHES OF THAT HAS FALLEN IN THE LAST HOUR. ALSO SEEING A SIGNS OF A REAR INFLOW JET DEVELOPING IN THE BACK SIDE OF CONVECTION CLOSING IN ON BRYAN/COLLEGE STATION. BASED ON IR IMAGERY SEEMS CLOUD TOPS ARE COOLING MORE SO EXPECT DEEP CONVECTION TO CONTINUE THROUGH THE MORNING. THE MAIN THREAT WILL BE HEAVY RAINFALL ON THE ORDER OF 2 TO 3 INCHES AN HOUR LIKE ALREADY OBSERVED. STORM MOTIONS ARE EXPECTED TO BE SLOW AS IN 10 TO 2O MPH BUT COULD SEE CELLS CONTINUE TO DEVELOP ALONG A FRONT PUSHING INTO THE AREA WHICH COULD TRAIN ACROSS AREAS THAT HAVE ALREADY RECEIVED RAINFALL. SFC ANALYSIS AT 09Z SHOWS FRONTAL BOUNDARY SLOWLY PUSHING SOUTH FROM THE ARLATEX THROUGH C TX INTO THE NW HILL COUNTRY. LOOK FOR CURRENT CONVECTION TO SLOWLY WORK SOUTH AHEAD OF THE FRONT AND POSSIBLY OUT RUN IT BY A GOOD BIT. THE 00Z HIRES-WRF-ARW/TXTECH WRF AND HRRR ALL SHOW CURRENT LINE OF CONVECTION WORKING SOUTH THROUGH SE TX IN A BROKEN LINE. THE LINE THEN WEAKENS AS IT APPROACHES THE COAST BETWEEN 15Z-18Z. DECIDED TO KEEP SOME 50/60 POPS THROUGH 12-15Z AND THEN GRADUALLY DECREASE RAIN CHANCES. LOOKS LIKE THIS PART OF THE FORECAST MAY GO THROUGH ADDITIONAL MODIFICATIONS DEPENDING ON HOW THE CONVECTION EVOLVES THIS MORNING. DO THINK THIS CONVECTION SHOULD WORK OVER AND STABILIZE THE ATMOSPHERE FOR THE AFTERNOON SO 20 POPS FOR THE AFTERNOON LOOKS GOOD BUT IT COULD BE DRY. AS IT HAS BEEN DISCUSSED BEFORE...MAIN HAZARD THIS MORNING WILL BE HEAVY RAINFALL. UPPER LEVEL ANALYSIS SHOWS A TROUGH AXIS WORKING THROUGH THE AREA AND THERE MAY BE ENOUGH UPPER LEVEL SUPPORT TO KEEP CONVECTION GOING THIS MORNING. EXPECT UPPER LEVEL ASCENT TO WEAKEN DURING THE AFTERNOON AND CONVERGENCE ALONG THE FRONT TO WEAKEN AS WELL. THUS BEST CHANCES FOR HEAVY RAIN STILL THIS MORNING AND THREAT DIMINISHING IN THE AFTERNOON. PRECIP WATER VALUES THIS MORNING PEAK INVOF CONVECTION AROUND 1.8-2.0 INCHES AND DECREASE THIS AFTERNOON TO BELOW 1.5 INCHES. AS FOR THE REST OF THE FORECAST...MODELS STILL BRING WEAK FRONT TO THE COAST AND POSSIBLY OFF THE COAST. EXPECT SFC DEWPOINT TEMPS TO DROP INTO THE LOW 60S WHICH WILL SEEM QUITE A BIT DRIER THAN THE MID 70S DEWPOINTS OF LATE. THIS ALSO MEANS SEASONABLE MIN TEMPS IN THE MID 60S FOR MON/TUE. EXPECT DRY CONDITIONS TO PERSIST AS UPPER LEVEL RIDGING BUILDS OVER S TX THROUGH MID WEEK. RIDGE DOES SHOW SIGNS OF BREAKING DOWN AGAIN FOR THE END OF THE WEEK WITH AN UPPER LOW OVER THE N PLAINS/MIDWEST/GREAT LAKES. THIS INTRODUCES NW FLOW ALOFT OVER TX FOR THE END OF THE WEEK WHICH MAY ALSO SUPPORT A WEAK FRONT MOVING INTO TX ALONG WITH A SERIES OF WEAK SHORTWAVES THAT COULD INITIATE A FEW ROUNDS OF CONVECTION ALONG THE RED RIVER AND N TX. POSSIBLE SOME OF THIS CONVECTION COULD WORK INTO SE TX. WILL KEEP 20 POPS FOR THE END OF THE WEEK WITH INCREASED MOISTURE AND FAVORABLE UPPER LEVEL PATTERN. AS WITH TROPICAL SEASON WILL KEEP AN EYE ON CONVECTION IN THE BAY OF CAMPECHE AND YUCATAN PENINSULA. BOTH GFS/ECMWF SUPPORT CONVECTION BECOMING ORGANIZED AGAIN FROM REMNANTS OF BARBARA BY TUESDAY. BOTH MODELS ALSO BRING THIS NEW SYSTEM INTO FLORIDA THUR/FRI TIME FRAME. THERE WILL BE A DECENT AMOUNT OF WIND SHEAR SO TOUGH TO KNOW HOW ORGANIZED THE SYSTEM WILL BECOME. NONETHELESS ALL INDICATIONS ARE THAT THIS WILL NOT BE A THREAT FOR THE TX COAST. 39 && .MARINE... LIGHT ONSHORE FLOW SHOULD BECOME LIGHT AND VARIABLE BY THIS AFTERNOON IN ADVANCE OF A WEAK COLD FRONT. LIGHT EAST TO SOUTHEAST WINDS AND 1 TO 2 FOOT SEAS WILL BE THE PREVAILING CONDITION THROUGH THE MAJORITY OF NEXT WEEK BECAUSE OF A VERY LIGHT PRESSURE GRADIENT BEHIND THE FRONT. 44 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 89 64 92 68 93 / 30 10 0 0 0 HOUSTON (IAH) 91 67 92 69 93 / 50 10 0 0 0 GALVESTON (GLS) 87 75 88 76 88 / 50 10 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39 AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1037 AM CDT SUN JUN 2 2013 .DISCUSSION... ISSUED 1037 AM CDT SUN JUN 2 2013 MORNING SURFACE ANALYSIS SHOWS A WEAK TROUGH AXIS EXTENDING FROM THE GREAT LAKES S/SW INTO CENTRAL ILLINOIS. 13Z HRRR SUGGESTS ISOLATED SHOWERS WILL DEVELOP ALONG/AHEAD OF THIS FEATURE ACROSS THE EASTERN HALF OF THE KILX CWA LATER THIS MORNING THROUGH THE AFTERNOON. HAVE SEEN SOME WEAK RADAR ECHOES DEVELOPING WITHIN THE PAST COUPLE OF HOURS...SO THIS SEEMS TO BE A PLAUSIBLE SOLUTION. WILL THEREFORE MAINTAIN THE SLIGHT CHANCE POPS ALONG AND EAST OF A BLOOMINGTON TO EFFINGHAM LINE. SKIES WILL REMAIN CLOUDY TODAY...AS EVIDENCED BY CURRENT VISIBLE SATELLITE IMAGERY AND STRONGLY NEGATIVE CU-RULE. DUE TO THE CLOUDS AND A COOL NORTHWESTERLY WIND...HIGH TEMPS WILL REMAIN WELL BELOW NORMAL FOR THIS TIME OF YEAR. HAVE TWEAKED AFTERNOON HIGHS DOWN A FEW DEGREES...WITH READINGS MAINLY IN THE MIDDLE TO UPPER 60S. A FEW LOWER 70S WILL BE POSSIBLE SOUTH OF I-70. ZONE UPDATE HAS ALREADY BEEN ISSUED. BARNES && .AVIATION... ISSUED 640 AM CDT SUN JUN 2 2013 NOT MUCH OF A SHIFT IN THE FORECAST...AS BEHIND THE FRONTAL PASSAGE...PLENTY OF MOISTURE IN THE BOUNDARY LAYER CONTRIBUTING TO THE PERSISTENT STRATUS DECK MOVING ACROSS THE MIDWEST. MOSTLY MVFR...WITH SOME TEMP SPOTS OF IFR. CIGS SLOWLY ON THE RISE WITH THE WARMING OF THE DAY. LATER THIS AFTERNOON...GET INTO LESS CYCLONIC FLOW ALOFT...AND SHOULD START TO SCATTER OUT. CHANCE FOR SOME VC SH IN BMI CMI AND DEC...BUT LIKELY SO SCT THAT MENTION NOT NEEDED AT THIS POINT. MAJOR CONCERN IS THE RIDGE MOVING OVHD IN THE OVERNIGHT HOURS...WITH CLEARING SKIES AND LIGHT WINDS...MAY SEE FOG DEVELOP. GUIDANCE NOT REFLECTING THE POTENTIAL...BUT BUFKIT FAVORING FOG. FOR NOW...WILL START A TREND...AND WILL HAVE TO WATCH THE XOVER TEMPS THROUGH THE AFTERNOON. HJS && .PREV DISCUSSION... ISSUED 225 AM CDT SUN JUN 2 2013 COLD FRONT HAS PUSHED WELL TO THE EAST EARLY THIS MORNING. 2 AM SURFACE MAP SHOWS A SECONDARY TROUGH SWINGING ACROSS THE NORTHWEST PART OF ILLINOIS...AROUND LOW PRESSURE IN NORTHEAST LOWER MICHIGAN. EXTENSIVE STRATOCUMULUS IS FOUND ALONG AND BEHIND THIS TROUGH...WHILE SKIES HAVE BEEN CLEAR OVER THE EASTERN CWA THE PAST FEW HOURS BETWEEN THE TROUGH AND FRONT. THE MAIN FORECAST ISSUE FOR THIS PACKAGE INVOLVES MID WEEK RAIN CHANCES. SHORT TERM...TODAY THROUGH TUESDAY... HAVE MAINTAINED SOME 20 PERCENT RAIN CHANCES ACROSS THE EASTERN CWA TODAY AS THE TROUGH SWINGS THROUGH...BUT QUIET WEATHER WILL GENERALLY PREVAIL THROUGH TUESDAY. 850 MB TEMPS FALLING INTO THE LOW SINGLE DIGITS CELSIUS TONIGHT SHOULD ALLOW FOR SURFACE LOWS IN THE UPPER 40S OVER ABOUT THE NORTHEAST HALF OF THE CWA...WITH HIGHS IN THE UPPER 60S TO AROUND 70. AS SURFACE HIGH PRESSURE SHIFTS EASTWARD ACROSS THE GREAT LAKES MONDAY NIGHT...DECENT WARM AIR ADVECTION WILL OVERSPREAD THE CWA AND BRING HIGHS WELL INTO THE 70S. LONG TERM...TUESDAY NIGHT THROUGH SATURDAY... EVENING MODEL GUIDANCE IN REASONABLE AGREEMENT WITH ZIPPING AN UPPER TROUGH THROUGH THE NORTHERN AND CENTRAL PLAINS ON TUESDAY...ASSOCIATED WITH A CLOSED SURFACE LOW CLOSER TO THE CANADIAN BORDER. NOT TOO MUCH CHANGE NOTED WITH TRENDS OF SPREADING RAIN CHANCES INTO AREAS WEST OF I-55 BY LATE TUESDAY NIGHT. RATHER PERSISTENT EASTERLY FLOW ACROSS THE GREAT LAKES DOES NOT BODE VERY WELL FOR DECENT PRECIP CHANCES IN THE EAST...AND WILL GO WITH SLIGHT CHANCES THERE ON WEDNESDAY. MAIN TROUGH AXIS SHOULD CROSS THE AREA LATE WEDNESDAY NIGHT THROUGH THURSDAY... WHEN HIGHEST POPS OF 40 TO 50 PERCENT WILL BE IN THE FORECAST. LATE IN THE WEEK...HAVE MAINTAINED SOME SLIGHT CHANCES FOR FRIDAY. HOWEVER...GENERAL TREND SHOULD BE FOR DRY WEATHER INTO THE FIRST HALF OF THE WEEKEND...WITH HIGH PRESSURE RIDGING SOUTHWEST FROM THE GREAT LAKES. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR ILZ051. && $$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1017 AM CDT SUN JUN 2 2013 .UPDATE... LOOKING AT OVERALL RADAR TRENDS...HAVE ADJUSTED POPS FOR TODAY TO REFLECT THE ONGOING CONVECTION OVER COASTAL LOUISIANA AND THE WEAK MESOHIGH IN THE WAKE OF THE EARLY MORNING CONVECTION OVER THE REMAINDER OF THE CWA. HAVE ALSO ADJUSTED CLOUD COVER TO REFLECT OVERALL HIGHER AMOUNT OF SKY COVER THAN INITALLY ANTICIPATED. THE RAIN COOLED STABLE AIRMASS COMBINED WITH THE CLOUD COVER HAS ALSO ALLOWED FOR SLOWLY TEMPERATURE RECOVERY AND ADJUSTED DAYTIME HIGHS DOWNWARD A FEW DEGREES. EXPECT TO SEE SOME RECOVERY THIS AFTERNOON OF WARMTH AND MOISTURE WHICH WILL ALLOW FOR SOME REGENERATION IN AREAS NOT COMPLETELY WORKED OVER THIS MORNING. GIVEN THIS...KEEP LIKELY POPS IN PLACE FOR COASTAL LOUISIANA AND MISSISSIPPI...AND ONLY HAVE CHANCE POPS ELSEWHERE. STILL EXPECT ACTUAL FRONTAL PASSAGE TONIGHT...WITH A DRIER WEATHER REGIME TAKING HOLD FOR MUCH OF THE WEEK. 32 && .PREV DISCUSSION... /ISSUED 415 AM CDT SUN JUN 2 2013/ SHORT TERM... MOST ACTIVE PORTION OF THE FORECAST WILL BE OVER THE NEXT 12 TO 15 HOURS. SURFACE ANALYSIS SHOWS COLD FRONT DRAPED ACROSS SOUTH-CENTRAL TEXAS...NORTHERN LA THROUGH EASTERN ARKANSAS AND POINTS FURTHER NORTH. A LARGE CLUSTER OF SHOWERS AND EMBEDDED STRONGER THUNDERSTORMS AHEAD OF THE FRONT HAS BEEN SURGING SOUTHWARD OVERNIGHT. AT THIS POINT...THIS ACTIVITY HAS BECOME OUTFLOW DRIVEN VS THE MEAN FLOW WHICH WOULD BE MORE EASTERLY. HRRR SEEMS TO BE THE ONLY MESO MODEL THAT HAS BEEN HAVING A GOOD INITIATION. IT SUGGESTS A WEAKENING TREND WILL CONTINUE AS THE LEADING EDGE MOVES SOUTH ACROSS MS AND LA TOWARDS THE CWA. WHILE IN GENERAL THIS WILL LIKELY BE THE CASE...THERE/S STILL SOME INSTABILITY IN PLACE OVER THE AREA WHICH WILL ALLOW A FEW CELLS TO BURST UP TO STRONG CATEGORY WITH STRONG GUSTY WINDS. HAVE SLIGHTLY BUMPED UP POPS TODAY...MAINLY TO ACCOUNT FOR ACTIVITY THAT SHOULD BE GOING ON THIS MORNING. AFTER IT DISSIPATES... DEVELOPMENT OF AFTERNOON SHOWERS AND A FEW THUNDERSTORMS WILL STILL BE POSSIBLE AS INSTABILITY REMAINS IN PLACE. COLD FRONT WILL STILL BE PUSHING SOUTH THROUGHOUT THE NIGHT AND SHOULD BE REACHING THE COAST BY 12Z MONDAY. HAVE TRIMMED POPS FURTHER SOUTH FOR THE MORNING PERIOD SO THAT ONLY COASTAL PARISHES AND OFFSHORE WATERS HAVE WORDING OF RAIN IN THE ZONES. LONG TERM... WEAK UPPER LEVEL RIDGING WILL BUILD INTO THE AREA MID WEAK AS UPPER TROUGH EJECTS. SUBSEQUENTLY...RAIN CHANCES WILL DROP OFF MONDAY AFTERNOON THROUGH WEDNESDAY. IN ADDITION...DAYTIME HIGHS WILL BE ON THE RISE AS HEIGHTS INCREASE. TEMPS SHOULD MAKE IT TO THE 90 TO 93 DEGREE MARK FAIRLY EASILY. AN UPPER TROUGH WILL TRACK ACROSS THE UPPER MISSISSIPPI VALLEY IN THE LATTER PORTION OF THIS WEEK. THIS WILL BREAKDOWN THE EAST SIDE OF UPPER RIDGE OVER THE GULF COAST THUS ALLOWING FOR AFTERNOON SHOWERS AND THUNDERSTORMS TO BEGIN DEVELOPING AGAIN. MEFFER AS HAS BEEN THE CASE FOR SEVERAL NIGHTS...THE OVERNIGHT AVIATION PROBLEM WILL BE THE DEVELOPMENT OF LOW CLOUDS. SEEING SOME DEVELOPMENT IN THE FL015-FL025 RANGE...MOST NOTABLY AT KHUM...AT THIS TIME. EXPECT SCT-BKN CLOUDS TO BECOME WIDESPREAD ACROSS THE AREA BY 09Z AND REMAIN THROUGH ABOUT 15Z. ONE OR TWO SITES WILL LIKELY FALL INTO THE IFR RANGE...PROBABLY AT KMCB. THE OTHER PROBLEM WILL BE THE TIMING OF CONVECTION ASSOCIATED WITH THE FRONTAL BOUNDARY. CURRENT MOVEMENT APPEARS TO BE ABOUT 340/17 KTS. THIS WILL ALLOW CONVECTION TO REACH KMCB AND KBTR SOMETIME AROUND SUNRISE...ALTHOUGH A STRAY SHOWER OR TWO COULD REACH KMCB BEFORE THEN. EXPECT A WEAKENING TREND FROM WHAT IS BEING OBSERVED AT THIS TIME. WILL LEAD INTO EVENT WITH MENTION OF VCSH/VCTS AND CARRY ABOUT A 4 HOUR WINDOW WITH THE MAIN CONVECTION. FOR NOW...WILL ONLY USE TEMPO GROUPS AT KMCB...KBTR AND KHDC. WILL ADJUST LATER AS WE CAN BETTER ANTICIPATE TIMING AT TERMINALS FARTHER SOUTH AND EAST. STILL NOT CONFIDENT ON EXACTLY HOW FAR SOUTHWARD FRONT WILL MAKE IT ON SUNDAY BEFORE RUNNING OUT OF PUSH. WIND FIELD WILL LIKELY BECOME RATHER WEAK TOWARD EVENING. 35 MARINE... WIND FIELD IS CONSIDERABLY WEAKER THIS MORNING THAN IT HAS BEEN FOR SEVERAL DAYS. WITH A WEAKENING COLD FRONT ANTICIPATED TO MOVE INTO THE AREA TODAY...WIND FIELDS WILL BECOME EVEN LIGHTER. WIND DIRECTIONS WILL BE RATHER VARIABLE...BUT GENERALLY WITH AN EASTERLY COMPONENT. NOT EXPECTING WINDS TO BE MUCH ABOVE 10 KNOTS BEFORE THURSDAY...WITH THE POSSIBLE EXCEPTION OF THE USUAL EVENING DIURNAL MAXIMUM. EVEN THEN...DO NOT ANTICIPATE WINDS STRONG ENOUGH TO REQUIRE HEADLINES. 35 DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SLURRY SUPPORT. MONITORING RIVER FLOODING. MONITORING CONVECTIVE TRENDS. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 81 66 88 63 / 50 20 10 10 BTR 82 68 89 67 / 50 20 10 10 ASD 83 70 90 69 / 70 30 10 10 MSY 82 73 89 72 / 70 30 10 10 GPT 84 71 89 69 / 70 30 10 10 PQL 86 71 88 68 / 70 30 10 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$ 32
AREA FORECAST DISCUSSION
NWS GRAY ME
1135 AM EDT SUN JUN 2 2013 .SYNOPSIS... HIGH PRESSURE SHIFTS EAST TODAY WITH A COLD FRONT APPROACHING FROM THE WEST. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP TODAY AHEAD OF THE FRONT WITH THE POTENTIAL TO PRODUCE STRONG WINDS AND HEAVY RAIN. THE FRONT IS SLOW TO PUSH THROUGH THE AREA AND THERE WILL BE A THREAT FOR MORE SHOWERS AND THUNDERSTORMS NEAR THE COAST ON MONDAY. HIGH PRESSURE WILL BUILD SOUTHEAST OUT OF CANADA THROUGH THE MIDDLE OF THE WEEK...BRINGING COOLER WEATHER BACK INTO THE AREA. && .NEAR TERM /TODAY/... 1130AM UPDATE... HAVE UPDATED THE FORECAST PRODUCTS TO INCLUDE SEVERE THUNDERSTORM WATCH 271 FOR ALL OF NEW HAMPSHIRE AND MOST OF WESTERN MAINE. 11AM UPDATE... MADE FURTHER ADJUSTMENTS TO HOURLY POP FORECAST TO SHOW PROGRESSION OF PRECIPITATION CHANCES ACROSS THE AREA. LINE OF STORMS HAS FORMED IN VERMONT AND IS MOVING INTO NEW HAMPSHIRE NOW. OTHER CUMULUS HAS DEVELOPED OVER THE MOUNTAINS OF WESTERN MAINE WHICH MAY LEAD TO THUNDERSTORM DEVELOPMENT AS WELL. SEVERE THUNDERSTORM WATCH MAY BE NEEDED BY THIS AFTERNOON. 815AM UPDATE... HAVE MADE ADJUSTMENTS MAINLY TO HOURLY POP GRIDS TO REFLECT THAT RAIN IS NOT EXPECTED NOW BUT CHANCES INCREASE AFTER ABOUT 11AM. STILL EXPECTING SHOWERS AND THUNDERSTORMS TO FORM ACROSS NEW HAMPSHIRE AND NORTHWEST MAINE LATE THIS MORNING OR EARLY THIS AFTERNOON... WITH A LINE FORMING AND MOVING ACROSS THE AREA THIS EVENING. STILL A THREAT FOR DAMAGING WINDS PRIMARILY. 7AM UPDATE... HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS ACROSS MAINE/NEW HAMPSHIRE. BANDS OF SHOWERS AND STORMS THAT WERE LOCATED ACROSS THE MOUNTAINS HAS WEAKENED AND SHIFTED NORTH. MEANWHILE...A LARGE AREA OF PRECIPITATION WITH EMBEDDED CONVECTION IS MOVING NORTHEAST INTO UPSTATE NEW YORK. TIMING OF PRECIPITATION MAY NEED TO BE NUDGED FORWARD IN TIME A COUPLE HOURS...HOWEVER LATEST HRRR RUN CONTINUES TO SHOW THE CONVECTION REACHING THE MOUNTAINS OF MAINE AND WESTERN NEW HAMPSHIRE BETWEEN 19Z- 20Z. HAVE ADJUSTED CLOUDS BASED ON SATELLITE IMAGERY...DEW POINTS AND TEMPERATURES THIS PACKAGE. ORIGINAL DISCUSSION... A SLIGHT RISK FOR SEVERE THUNDERSTORMS CONTINUES TODAY INTO THIS EVENING. CONVECTION WILL REDEVELOP TODAY AHEAD OF AN APPROACHING COLD FRONT AND PRE FRONTAL SURFACE TROUGH. STRONG WIND FIELDS WILL ALLOW FOR THE POSSIBILITY OF DAMAGING WINDS...MAINLY IN BOWING OR LEWP SEGMENTS. CANNOT RULE OUT THE POSSIBILITY OF HAIL IN ANY DISCRETE STORMS. MID LEVEL LAPSE RATES DECREASE DURING THE DAY...AND WITH GOOD SOLAR HEATING OVER SOUTHERN INTERIOR SECTIONS...CAPE VALUES WILL CLIMB TO AT OR ABOVE 1000 J/KG...WITH A FEW FAR SOUTHERN INTERIOR AREAS APPROACHING 2000 J/KG. LOW LEVEL HELICITY VALUES WILL INCREASE DURING THE DAY AS WELL WHICH MAY LEAD TO ISOLATED SUPERCELLS. STORM MOTION WILL BE RELATIVELY RAPID...BUT WITH THE FRONT SLOWLY OVER THE REGION...TRAINING ECHOES MAY LEAD TO LOCALLY HEAVY RAINFALL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... THUNDERSTORMS WILL BE CONTINUING INTO TONIGHT AS SURFACE COLD FRONT CONTINUES TO SLOW IN ITS FORWARD MOTION. FAR SOUTHERN AREAS MAY HAVE YET ANOTHER ROUND OF SHOWERS AND STORMS MONDAY MORNING AS MODELS CONTINUE TO SHOW A WEAKNESS IN THE SURFACE FIELDS AND POSSIBLY THE DEVELOPMENT OF A WAVE OF LOW PRESSURE IN THE GULF OF MAINE. THE PRECIPITATION WILL ALLOW FOR A MOIST GROUND AND MORE PATCHY FOG TO DEVELOP TONIGHT. USED OF A BLEND OF MAV/MET MOS FOR OVERNIGHT MINS AND DAYTIME HIGHS ON MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE COLD FRONT MOVES OFF THE COAST BY MONDAY EVENING ALLOWING CLEARING BEHIND THE FRONT ON A DEVELOPING WNW DOWNSLOPING FLOW. TUESDAY/WEDNESDAY THE DRIER NW FLOW WILL BRING A RETURN TO A MUCH DRIER AIR MASS AND NEAR NORMAL TEMPERATURES. LATE IN THE WEEK AN UPPER LONGWAVE TROUGH WILL BE CARVED OUT OVER THE GREAT LAKES THAT WILL GRADUALLY DEEPEN AND SPREAD A MOIST UNSTABLE SW FLOW ALOFT INTO THE REGION WHILE IN THE LOW LEVELS A MOIST COOL SE FLOW STRENGTHENS. FRIDAY/SATURDAY THIS UPPER TROUGH WILL REMAIN TO OUR WEST BUT SEVERAL WEAK COASTAL LOWS MAY TRY TO DEVELOP AND POSSIBLY SPREAD STEADIER RAINS ACROSS THE AREA. QPF AMOUNTS WILL BECOME DEPENDENT ON THE PRECISE EVOLUTION OF THIS BROAD COMPLEX SYSTEM LATE IN THE WEEK. ALL MODELS ARE HINTING AT THIS BUT WITH SOME DIFFERENCES IN TIMING AND SCENARIOS. LATE IN THE WEEK TEMPERATURES WILL BE QUITE COOL AS THE MOIST DAMP SE FLOW DEVELOPS. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... SHORT TERM... GENERALLY VFR CONDITIONS TO START THE DAY. CEILINGS/VISIBILITIES BEGIN TO LOWER DURING THE EARLY AFTERNOON HOURS IN THE MOUNTAINS AS SHOWERS AND THUNDERSTORMS DEVELOP AHEAD OF AN APPROACHING COLD FRONT. EXPECT IFR CONDITIONS WITH LOCALLY LIFR IN ANY SHOWERS AND STORMS AS THEY GRADUALLY EXIT THE MOUNTAINS AND MOVE TOWARDS THE COASTLINE BY LATER IN THE DAY. SCATTERED SHOWERS AND STORMS WILL CONTINUE TONIGHT...AND ALSO MONDAY MORNING OVER FAR SOUTHERN SECTIONS. LONG TERM... VFR CONDITIONS TUESDAY/WEDNESDAY BECOMING MVFR IN DEVELOPING SCATTERED SHOWERS BY LATE THURSDAY. && .MARINE... SHORT TERM... EXPECT WINDS TO STRENGTHEN TODAY AHEAD OF THE COLD FRONT WITH WAVE HEIGHTS INCREASING AS WELL. SCA CONTINUES THRU LATE TONIGHT...BUT WINDS SHOULD STAY BELOW GALE CRITERIA. SCAS EXPANDED TO INCLUDE THE BAYS AS WAVES WILL BE INCREASING AS WELL. LONG TERM... WINDS AND SEAS TO REMAIN BELOW SCA CONDITIONS. && .FIRE WEATHER... INCREASING MOISTURE ACROSS THE AREA WILL KEEP RELATIVE HUMIDITY VALUES UP THE NEXT FEW DAYS. THUNDERSTORMS WILL POSE A RISK OF LIGHTNING BUT WILL ALSO BE PROVIDING SUBSTANTIAL RAINFALL TO AREAS WHICH ARE AFFECTED BY THEM. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ150>154. && $$ NEAR TERM UPDATE... KIMBLE
AREA FORECAST DISCUSSION
NWS GRAY ME
1103 AM EDT SUN JUN 2 2013 .SYNOPSIS... HIGH PRESSURE SHIFTS EAST TODAY WITH A COLD FRONT APPROACHING FROM THE WEST. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP TODAY AHEAD OF THE FRONT WITH THE POTENTIAL TO PRODUCE STRONG WINDS AND HEAVY RAIN. THE FRONT IS SLOW TO PUSH THROUGH THE AREA AND THERE WILL BE A THREAT FOR MORE SHOWERS AND THUNDERSTORMS NEAR THE COAST ON MONDAY. HIGH PRESSURE WILL BUILD SOUTHEAST OUT OF CANADA THROUGH THE MIDDLE OF THE WEEK...BRINGING COOLER WEATHER BACK INTO THE AREA. && .NEAR TERM /TODAY/... 11AM UPDATE... MADE FURTHER ADJUSTMENTS TO HOURLY POP FORECAST TO SHOW PROGRESSION OF PRECIPITATION CHANCES ACROSS THE AREA. LINE OF STORMS HAS FORMED IN VERMONT AND IS MOVING INTO NEW HAMPSHIRE NOW. OTHER CUMULUS HAS DEVELOPED OVER THE MOUNTAINS OF WESTERN MAINE WHICH MAY LEAD TO THUNDERSTORM DEVELOPMENT AS WELL. SEVERE THUNDERSTORM WATCH MAY BE NEEDED BY THIS AFTERNOON. 815AM UPDATE... HAVE MADE ADJUSTMENTS MAINLY TO HOURLY POP GRIDS TO REFLECT THAT RAIN IS NOT EXPECTED NOW BUT CHANCES INCREASE AFTER ABOUT 11AM. STILL EXPECTING SHOWERS AND THUNDERSTORMS TO FORM ACROSS NEW HAMPSHIRE AND NORTHWEST MAINE LATE THIS MORNING OR EARLY THIS AFTERNOON... WITH A LINE FORMING AND MOVING ACROSS THE AREA THIS EVENING. STILL A THREAT FOR DAMAGING WINDS PRIMARILY. 7AM UPDATE... HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS ACROSS MAINE/NEW HAMPSHIRE. BANDS OF SHOWERS AND STORMS THAT WERE LOCATED ACROSS THE MOUNTAINS HAS WEAKENED AND SHIFTED NORTH. MEANWHILE...A LARGE AREA OF PRECIPITATION WITH EMBEDDED CONVECTION IS MOVING NORTHEAST INTO UPSTATE NEW YORK. TIMING OF PRECIPITATION MAY NEED TO BE NUDGED FORWARD IN TIME A COUPLE HOURS...HOWEVER LATEST HRRR RUN CONTINUES TO SHOW THE CONVECTION REACHING THE MOUNTAINS OF MAINE AND WESTERN NEW HAMPSHIRE BETWEEN 19Z- 20Z. HAVE ADJUSTED CLOUDS BASED ON SATELLITE IMAGERY...DEW POINTS AND TEMPERATURES THIS PACKAGE. ORIGINAL DISCUSSION... A SLIGHT RISK FOR SEVERE THUNDERSTORMS CONTINUES TODAY INTO THIS EVENING. CONVECTION WILL REDEVELOP TODAY AHEAD OF AN APPROACHING COLD FRONT AND PRE FRONTAL SURFACE TROUGH. STRONG WIND FIELDS WILL ALLOW FOR THE POSSIBILITY OF DAMAGING WINDS...MAINLY IN BOWING OR LEWP SEGMENTS. CANNOT RULE OUT THE POSSIBILITY OF HAIL IN ANY DISCRETE STORMS. MID LEVEL LAPSE RATES DECREASE DURING THE DAY...AND WITH GOOD SOLAR HEATING OVER SOUTHERN INTERIOR SECTIONS...CAPE VALUES WILL CLIMB TO AT OR ABOVE 1000 J/KG...WITH A FEW FAR SOUTHERN INTERIOR AREAS APPROACHING 2000 J/KG. LOW LEVEL HELICITY VALUES WILL INCREASE DURING THE DAY AS WELL WHICH MAY LEAD TO ISOLATED SUPERCELLS. STORM MOTION WILL BE RELATIVELY RAPID...BUT WITH THE FRONT SLOWLY OVER THE REGION...TRAINING ECHOES MAY LEAD TO LOCALLY HEAVY RAINFALL. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... THUNDERSTORMS WILL BE CONTINUING INTO TONIGHT AS SURFACE COLD FRONT CONTINUES TO SLOW IN ITS FORWARD MOTION. FAR SOUTHERN AREAS MAY HAVE YET ANOTHER ROUND OF SHOWERS AND STORMS MONDAY MORNING AS MODELS CONTINUE TO SHOW A WEAKNESS IN THE SURFACE FIELDS AND POSSIBLY THE DEVELOPMENT OF A WAVE OF LOW PRESSURE IN THE GULF OF MAINE. THE PRECIPITATION WILL ALLOW FOR A MOIST GROUND AND MORE PATCHY FOG TO DEVELOP TONIGHT. USED OF A BLEND OF MAV/MET MOS FOR OVERNIGHT MINS AND DAYTIME HIGHS ON MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE COLD FRONT MOVES OFF THE COAST BY MONDAY EVENING ALLOWING CLEARING BEHIND THE FRONT ON A DEVELOPING WNW DOWNSLOPING FLOW. TUESDAY/WEDNESDAY THE DRIER NW FLOW WILL BRING A RETURN TO A MUCH DRIER AIR MASS AND NEAR NORMAL TEMPERATURES. LATE IN THE WEEK AN UPPER LONGWAVE TROUGH WILL BE CARVED OUT OVER THE GREAT LAKES THAT WILL GRADUALLY DEEPEN AND SPREAD A MOIST UNSTABLE SW FLOW ALOFT INTO THE REGION WHILE IN THE LOW LEVELS A MOIST COOL SE FLOW STRENGTHENS. FRIDAY/SATURDAY THIS UPPER TROUGH WILL REMAIN TO OUR WEST BUT SEVERAL WEAK COASTAL LOWS MAY TRY TO DEVELOP AND POSSIBLY SPREAD STEADIER RAINS ACROSS THE AREA. QPF AMOUNTS WILL BECOME DEPENDENT ON THE PRECISE EVOLUTION OF THIS BROAD COMPLEX SYSTEM LATE IN THE WEEK. ALL MODELS ARE HINTING AT THIS BUT WITH SOME DIFFERENCES IN TIMING AND SCENARIOS. LATE IN THE WEEK TEMPERATURES WILL BE QUITE COOL AS THE MOIST DAMP SE FLOW DEVELOPS. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... SHORT TERM... GENERALLY VFR CONDITIONS TO START THE DAY. CEILINGS/VISIBILITIES BEGIN TO LOWER DURING THE EARLY AFTERNOON HOURS IN THE MOUNTAINS AS SHOWERS AND THUNDERSTORMS DEVELOP AHEAD OF AN APPROACHING COLD FRONT. EXPECT IFR CONDITIONS WITH LOCALLY LIFR IN ANY SHOWERS AND STORMS AS THEY GRADUALLY EXIT THE MOUNTAINS AND MOVE TOWARDS THE COASTLINE BY LATER IN THE DAY. SCATTERED SHOWERS AND STORMS WILL CONTINUE TONIGHT...AND ALSO MONDAY MORNING OVER FAR SOUTHERN SECTIONS. LONG TERM... VFR CONDITIONS TUESDAY/WEDNESDAY BECOMING MVFR IN DEVELOPING SCATTERED SHOWERS BY LATE THURSDAY. && .MARINE... SHORT TERM... EXPECT WINDS TO STRENGTHEN TODAY AHEAD OF THE COLD FRONT WITH WAVE HEIGHTS INCREASING AS WELL. SCA CONTINUES THRU LATE TONIGHT...BUT WINDS SHOULD STAY BELOW GALE CRITERIA. SCAS EXPANDED TO INCLUDE THE BAYS AS WAVES WILL BE INCREASING AS WELL. LONG TERM... WINDS AND SEAS TO REMAIN BELOW SCA CONDITIONS. && .FIRE WEATHER... INCREASING MOISTURE ACROSS THE AREA WILL KEEP RELATIVE HUMIDITY VALUES UP THE NEXT FEW DAYS. THUNDERSTORMS WILL POSE A RISK OF LIGHTNING BUT WILL ALSO BE PROVIDING SUBSTANTIAL RAINFALL TO AREAS WHICH ARE AFFECTED BY THEM. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ150>154. && $$ NEAR TERM UPDATE... KIMBLE
AREA FORECAST DISCUSSION
NWS GRAY ME
817 AM EDT SUN JUN 2 2013 .SYNOPSIS... HIGH PRESSURE SHIFTS EAST TODAY WITH A COLD FRONT APPROACHING FROM THE WEST. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP TODAY AHEAD OF THE FRONT WITH THE POTENTIAL TO PRODUCE STRONG WINDS AND HEAVY RAIN. THE FRONT IS SLOW TO PUSH THROUGH THE AREA AND THERE WILL BE A THREAT FOR MORE SHOWERS AND THUNDERSTORMS NEAR THE COAST ON MONDAY. HIGH PRESSURE WILL BUILD SOUTHEAST OUT OF CANADA THROUGH THE MIDDLE OF THE WEEK...BRINGING COOLER WEATHER BACK INTO THE AREA. && .NEAR TERM /TODAY/... 815AM UPDATE... HAVE MADE ADJUSTMENTS MAINLY TO HOURLY POP GRIDS TO REFLECT THAT RAIN IS NOT EXPECTED NOW BUT CHANCES INCREASE AFTER ABOUT 11AM. STILL EXPECTING SHOWERS AND THUNDERSTORMS TO FORM ACROSS NEW HAMPSHIRE AND NORTHWEST MAINE LATE THIS MORNING OR EARLY THIS AFTERNOON... WITH A LINE FORMING AND MOVING ACROSS THE AREA THIS EVENING. STILL A THREAT FOR DAMAGING WINDS PRIMARILY. 7AM UPDATE... HAVE UPDATED GRIDS BASED ON CURRENT CONDITIONS ACROSS MAINE/NEW HAMPSHIRE. BANDS OF SHOWERS AND STORMS THAT WERE LOCATED ACROSS THE MOUNTAINS HAS WEAKENED AND SHIFTED NORTH. MEANWHILE...A LARGE AREA OF PRECIPITATION WITH EMBEDDED CONVECTION IS MOVING NORTHEAST INTO UPSTATE NEW YORK. TIMING OF PRECIPITATION MAY NEED TO BE NUDGED FORWARD IN TIME A COUPLE HOURS...HOWEVER LATEST HRRR RUN CONTINUES TO SHOW THE CONVECTION REACHING THE MOUNTAINS OF MAINE AND WESTERN NEW HAMPSHIRE BETWEEN 19Z- 20Z. HAVE ADJUSTED CLOUDS BASED ON SATELLITE IMAGERY...DEW POINTS AND TEMPERATURES THIS PACKAGE. ORIGINAL DISCUSSION... A SLIGHT RISK FOR SEVERE THUNDERSTORMS CONTINUES TODAY INTO THIS EVENING. CONVECTION WILL REDEVELOP TODAY AHEAD OF AN APPROACHING COLD FRONT AND PRE FRONTAL SURFACE TROUGH. STRONG WIND FIELDS WILL ALLOW FOR THE POSSIBILITY OF DAMAGING WINDS...MAINLY IN BOWING OR LEWP SEGMENTS. CANNOT RULE OUT THE POSSIBILITY OF HAIL IN ANY DISCRETE STORMS. MID LEVEL LAPSE RATES DECREASE DURING THE DAY...AND WITH GOOD SOLAR HEATING OVER SOUTHERN INTERIOR SECTIONS...CAPE VALUES WILL CLIMB TO AT OR ABOVE 1000 J/KG...WITH A FEW FAR SOUTHERN INTERIOR AREAS APPROACHING 2000 J/KG. LOW LEVEL HELICITY VALUES WILL INCREASE DURING THE DAY AS WELL WHICH MAY LEAD TO ISOLATED SUPERCELLS. STORM MOTION WILL BE RELATIVELY RAPID...BUT WITH THE FRONT SLOWLY OVER THE REGION...TRAINING ECHOES MAY LEAD TO LOCALLY HEAVY RAINFALL. && .SHORT TERM /TONIGHT AND MONDAY/... THUNDERSTORMS WILL BE CONTINUING INTO TONIGHT AS SURFACE COLD FRONT CONTINUES TO SLOW IN ITS FORWARD MOTION. FAR SOUTHERN AREAS MAY HAVE YET ANOTHER ROUND OF SHOWERS AND STORMS MONDAY MORNING AS MODELS CONTINUE TO SHOW A WEAKNESS IN THE SURFACE FIELDS AND POSSIBLY THE DEVELOPMENT OF A WAVE OF LOW PRESSURE IN THE GULF OF MAINE. THE PRECIPITATION WILL ALLOW FOR A MOIST GROUND AND MORE PATCHY FOG TO DEVELOP TONIGHT. USED OF A BLEND OF MAV/MET MOS FOR OVERNIGHT MINS AND DAYTIME HIGHS ON MONDAY. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE COLD FRONT MOVES OFF THE COAST BY MONDAY EVENING ALLOWING CLEARING BEHIND THE FRONT ON A DEVELOPING WNW DOWNSLOPING FLOW. TUESDAY/WEDNESDAY THE DRIER NW FLOW WILL BRING A RETURN TO A MUCH DRIER AIR MASS AND NEAR NORMAL TEMPERATURES. LATE IN THE WEEK AN UPPER LONGWAVE TROUGH WILL BE CARVED OUT OVER THE GREAT LAKES THAT WILL GRADUALLY DEEPEN AND SPREAD A MOIST UNSTABLE SW FLOW ALOFT INTO THE REGION WHILE IN THE LOW LEVELS A MOIST COOL SE FLOW STRENGTHENS. FRIDAY/SATURDAY THIS UPPER TROUGH WILL REMAIN TO OUR WEST BUT SEVERAL WEAK COASTAL LOWS MAY TRY TO DEVELOP AND POSSIBLY SPREAD STEADIER RAINS ACROSS THE AREA. QPF AMOUNTS WILL BECOME DEPENDENT ON THE PRECISE EVOLUTION OF THIS BROAD COMPLEX SYSTEM LATE IN THE WEEK. ALL MODELS ARE HINTING AT THIS BUT WITH SOME DIFFERENCES IN TIMING AND SCENARIOS. LATE IN THE WEEK TEMPERATURES WILL BE QUITE COOL AS THE MOIST DAMP SE FLOW DEVELOPS. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... SHORT TERM... GENERALLY VFR CONDITIONS TO START THE DAY. CEILINGS/VISIBILITIES BEGIN TO LOWER DURING THE EARLY AFTERNOON HOURS IN THE MOUNTAINS AS SHOWERS AND THUNDERSTORMS DEVELOP AHEAD OF AN APPROACHING COLD FRONT. EXPECT IFR CONDITIONS WITH LOCALLY LIFR IN ANY SHOWERS AND STORMS AS THEY GRADUALLY EXIT THE MOUNTAINS AND MOVE TOWARDS THE COASTLINE BY LATER IN THE DAY. SCATTERED SHOWERS AND STORMS WILL CONTINUE TONIGHT...AND ALSO MONDAY MORNING OVER FAR SOUTHERN SECTIONS. LONG TERM... VFR CONDITIONS TUESDAY/WEDNESDAY BECOMING MVFR IN DEVELOPING SCATTERED SHOWERS BY LATE THURSDAY. && .MARINE... SHORT TERM... EXPECT WINDS TO STRENGTHEN TODAY AHEAD OF THE COLD FRONT WITH WAVE HEIGHTS INCREASING AS WELL. SCA CONTINUES THRU LATE TONIGHT...BUT WINDS SHOULD STAY BELOW GALE CRITERIA. SCAS EXPANDED TO INCLUDE THE BAYS AS WAVES WILL BE INCREASING AS WELL. LONG TERM... WINDS AND SEAS TO REMAIN BELOW SCA CONDITIONS. && .FIRE WEATHER... INCREASING MOISTURE ACROSS THE AREA WILL KEEP RELATIVE HUMIDITY VALUES UP THE NEXT FEW DAYS. THUNDERSTORMS WILL POSE A RISK OF LIGHTNING BUT WILL ALSO BE PROVIDING SUBSTANTIAL RAINFALL TO AREAS WHICH ARE AFFECTED BY THEM. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ150>154. && $$ NEAR TERM UPDATE... KIMBLE
AREA FORECAST DISCUSSION
NWS GRAY ME
656 AM EDT SUN JUN 2 2013 .SYNOPSIS... HIGH PRESSURE SHIFTS EAST TODAY WITH A COLD FRONT APPROACHING FROM THE WEST. EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP TODAY AHEAD OF THE FRONT WITH THE POTENTIAL TO PRODUCE STRONG WINDS AND HEAVY RAIN. THE FRONT IS SLOW TO PUSH THROUGH THE AREA AND THERE WILL BE A THREAT FOR MORE SHOWERS AND THUNDERSTORMS NEAR THE COAST ON MONDAY. HIGH PRESSURE WILL BUILD SOUTHEAST OUT OF CANADA THROUGH THE MIDDLE OF THE WEEK...BRINGING COOLER WEATHER BACK INTO THE AREA. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... HAVE UPDATED GRIDS BASED ON CURRENT CONDS ACROSS ME/NH. BANDS OF SHOWERS AND STORMS THAT WERE LOCATED ACROSS THE MTNS HAS WEAKENED AND SHIFTED NORTH. MEANWHILE...A LARGE AREA OF PCPN WITH EMBEDDED CONVECTION IS MOVING NE INTO UPSTATE NEW YORK. TIMING OF PCPN MAY NEED TO BE NUDGED FORWARD IN TIME A COUPLE HOURS...HOWEVER LATEST HRRR RUN CONTS TO SHOW THE CONVECTION REACHING THE MTNS OF ME AND WRNMST NH BTWN 19Z-20Z. HAVE ADJUSTED CLOUDS BASED ON STLT IMAGERY...DEW POINTS AND TEMPS THIS PACKAGE. PREV DISC... A SLGT RISK FOR SVR TSTMS CONTINUES TODAY INTO THIS EVENING. CONVECTION WILL REDEVELOP TODAY AHEAD OF AN APCHG COLD FRONT AND PREFRONTAL SFC TROUGH. STRONG WIND FIELDS WILL ALLOW FOR THE POSSIBILITY OF DAMAGING WINDS...MAINLY IN BOWING OR LEWP SEGMENTS. CANNOT RULE OUT THE POSSIBILITY OF HAIL IN ANY DESCRETE STORMS. MID LEVEL LAPSE RATES INCREASE DURING THE DAY...AND WITH GOOD SOLAR HEATING OVER SOUTHERN INTERIOR SECTIONS...CAPE VALUES WILL CLIMB TO AOA 1000 J/KG...WITH A FEW FAR SOUTHERN INTERIOR AREAS APCHG 2000 J/KG. LOW LEVEL HELICITY VALUES WILL INCREASE DURING THE DAY AS WELL WHICH MAY LEAD TO ISOLD SUPERCELLS. STORM MOTION WILL BE RELATIVELY RAPID...BUT WITH THE FRONT SLOWLY OVER THE REGION...TRAIN ECHOES MAY LEAD TO LOCALLY HEAVY RAINFALL. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... TSTMS WILL BE CONTINUING INTO TONIGHT AS SFC COLD FRONT CONTS TO SLOW IN ITS FORWARD MOTION. FAR SOUTHERN AREAS MAY HAVE YET ANOTHER ROUND OF SHOWERS AND STORMS MONDAY MORNING AS MODELS CONT TO SHOW A WEAKNESS IN THE SFC FIELDS AND POSSIBLY THE DEVELOPMENT OF A WAVE OF LOW PRESSURE IN THE GULF OF MAINE. THE PCPN WILL ALLOW FOR A MOIST GROUND AND MORE PATCHY FOG TO DEVELOP TONIGHT. USED OF ABLEND OF MAV/MET MOS FOR OVERNIGHT MINS AND DAYTIME HIGHS ON MONDAY. && .LONG TERM /TUESDAY THROUGH SATURDAY/... THE COLD FRONT MOVES OFF THE COAST BY MON EVENING ALLOWING CLEARING BEHIND THE FROPA ON A DEVELOPING WNWLY DOWNSLOPING FLOW. TUE/WED THE DRIER NWLY FLOW WILL BRING A RETURN TO A MUCH DRIER AMS AND NEAR NORMAL TEMPS. LATE IN THE WEEK AN UPPER L/WV TROF WILL BE CARVED OUT OVER THE GREAT LAKES THAT WILL GRADUALLY DEEPEN AND SPREAD A MOIST UNSTABLE SWLY FLOW ALOFT INTO THE REGION WHILE IN THE LOW LEVELS A MOIST COOL SELY FLOW STRENGTHENS. FRI/SAT THIS UPPER TROF WILL REMAIN TO OUR WEST BUT SEVERAL WEAK COASTAL LOWS MAY TRY TO DEVELOP AND POSSIBLY SPREAD STEADIER RAINS ACROSS THE AREA. QPF AMTS WILL BECOME DEPENDANT ON THE PRECISE EVOLUTION OF THIS BROAD COMPLEX SYSTEM LATE IN THE WEEK. ALL MODELS ARE HINTING AT THIS BUT WITH SOME DIFFERENCES IN TIMING AND SCENARIOS. LATE IN THE WEEK TEMPS WILL BE QUITE COOL AS THE MOIST DAMP SELY FLOW DEVELOPS. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... SHORT TERM... PATCHY FOG EXPECTED EARLY THIS MORNING...FOLLOWED BY GENERALLY VFR CONDITIONS. CIGS/VSBYS BEGIN TO LOWER DURING THE EARLY AFTERNOON HOURS IN THE MTNS AS SHOWERS AND TSTMS DEVELOP AHEAD OF AN APCHG COLD FRONT. EXPECT IFR CONDITIONS WITH LOCALLY LIFR IN ANY SHOWERS AND STORMS AS THEY GRADUALLY EXIT THE MTNS AND MOVE TOWARDS THE COASTLINE BY LATER IN THE DAY. SCT SHOWERS AND STMS WILL CONT TNGT...AND ALSO MONDAY MORNING OVER FAR SOUTHERN SECTIONS. LONG TERM... VFR CONDS TUE/WED BECOMING MVFR IN DVLP SCT SHWRS BY LATE THU. && .MARINE... SHORT TERM... EXPECT WINDS TO STRENGTHEN TODAY AHEAD OF THE COLD FRONT WITH WAVE HEIGHTS INCREASING AS WELL. SCA CONTINUES THRU LATE TONIGHT...BUT WINDS SHOULD STAY BELOW GALE CRITERIA. SCAS EXPANDED TO INCLUDE THE BAYS AS WAVES WILL BE INCREASING AS WELL. LONG TERM... WINDS AND SEAS TO REMAIN BELOW SCA CONDS. && .FIRE WEATHER... INCREASING MOISTURE ACROSS THE AREA WILL KEEP RELATIVE HUMIDITY VALUES UP THE NEXT FEW DAYS. THUNDERSTORMS WILL POSE A RISK OF LIGHTNING BUT WILL ALSO BE PROVIDING SUBSTANTIAL RAINFALL TO AREAS WHICH ARE AFFECTED BY THEM. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ150>154. && $$ JC
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1032 AM EDT SUN JUN 2 2013 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE WEST TODAY...THEN PASS THROUGH THE AREA TONIGHT AND MONDAY. CANADIAN HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT THROUGH MIDWEEK. ANOTHER FRONT MAY APPROACH THE MIDDLE ATLANTIC STATES AT THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... VSBLE SATL IMGRY AND SFC OBS SHOW EXTENSIVE CLOUD COVER OVER THE WESTERN HALF OF CWA. TEMPS ARE ALREADY IN THE LOW 80S IN THE MOSTLY SUNNY SKIES ALONG AND EAST OF I-95. MODIFIED 12Z KIAD SOUNDING GIVES ML CAPES IN THE VICINITY OF 1250-1500 J/KG. THE RR QUAD OF H4 JET WILL MOVE ACROSS THE THE NW PORTION OF CWA THIS AFTERNOON PROVIDING A LIFTING MECHANISM TO PRODUCE SHOWERS AND THUNDERSTORMS. THE THREAT FOR SVR WX EXISTS THIS AFTERNOON AND EVENING COINCIDING WITH PEAK INSOLATION. HAVED NUDGED TEMPS WEST OF THE BLUE RIDGE DOWN A COUPLE OF DEGREES DUE TO BKN-OVC. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... COLD FRONT ENTERS THE CWA TONIGHT. MODELS NOT YET CONSISTENT ON ITS EASTWARD PROGRESS BY MONDAY MORNING...WITH GFS HAVING THE FRONT THROUGH MOST OF THE AREA...ECMWF (12Z SUN) THE SLOWEST...AND THE NAM IN BETWEEN. WILL CONTINUE WITH POTENTIAL FOR SHOWERS AND TSTMS OVERNIGHT...WITH HIGHEST POPS EAST OF I-95 CORRIDOR. LOW TEMPS RANGE FROM THE LOW 60S OVER THE POTOMAC HIGHLANDS TO THE LOW 70S IN URBAN BALTIMORE/WASHINGTON. && .LONG TERM /MONDAY THROUGH SATURDAY/... COLD FRONT WILL BE MOVING THROUGH THE POTOMAC HIGHLANDS BY MONDAY MORNING. SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE AHEAD OF FROPA FOR AREAS ALONG AND EAST OF THE I-95 CORRIDOR THROUGHOUT THE MORNING AND AFTERNOON. FURTHER SOUTH AND EAST...LOW LEVEL JET WILL BECOME MORE PERPENDICULAR TO THE STORM MOTION AND HELP LEVITATE HEAVY RAIN THAT WE MAY SEE SUNDAY EVENING. FCST SOUNDINGS WILL STILL BE SATURATED WITH PWATS AT OR ABOVE 1.5 SO ISOLATED AREAS OF HEAVY RAIN WILL STILL POSE A THREAT FOR SOUTHERN MARYLAND MONDAY AFTERNOON WITHIN THUNDERSTORM ACTIVITY. HIGH PRESSURE AND NW FLOW BEHIND FROPA WILL DROP DEWPTS AS IT MOVES THROUGH THE MID ATLANTIC MONDAY NIGHT. CONTINENTAL AIR WILL BRING RELIEF OF RECENT WARM SPELL FOR THE START OF NEXT WEEK WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL. E-SE FLOW WILL BEGIN TUESDAY NIGHT AND USHER IN LOW LEVEL MOISTURE INTO THE MID ATLANTIC AS HIGH PRESSURE MOVES OFF SHORE. LOW PRESSURE FROM THE OHIO VALLEY WILL FORM ALONG A COLD FRONT AND MOVE TOWARDS THE REGION BY THE END OF THE WEEK. REGION SHOULD STAY DRY UNTIL THURSDAY NIGHT WHEN SHOWERS WILL OVERSPREAD THE AREA AS A UPPER TROUGH MOVES CLOSER. MULTIPLE SHORTWAVE TROUGHS AND LOW PRESSURE OFF THE ATLANTIC COAST MAY LEAD TO CLOUDY AND WET CONDITIONS TOWARDS THE END OF THE WEEK AND START OF THE WEEKEND. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND EVENING AND WILL LIKELY BRING IMPACTS TO THE TERMINALS. STORMS WILL HAVE THE POTENTIAL TO PRODUCE DAMAGING WINDS...HAIL AND HEAVY RAINFALL. AMENDMENTS MAY BE NECESSARY TO REFINE TIMING AND IMPACT OF SHOWERS/TSTMS. WINDS GENERALLY SW 10-15KT...POSSIBLY GUSTY AT TIMES. VFR CONDITIONS EXPECTED FOR THE START OF THE WORK WEEK WITH THE EXCEPTION OF SOME ONGOING SHOWERS AT IAD-DCA-BWI-MTN MONDAY. WINDS WILL SHIFT FROM THE SW TO THE NW BY MONDAY EVENING ACROSS ALL TERMINALS. && .MARINE... PRESSURE GRADIENT ON 00Z MODEL RUN IS A LITTLE LESS THAN PREVIOUS RUNS...AND WIND DIRECTION IS EXPECTED TO BE MORE SWLY THAN SOUTHERLY...WHICH WOULD INHIBIT CHANNELING. AS SUCH...SCA CONDITIONS WILL LIKELY BE SOMEWHAT MARGINAL...BUT WILL KEEP THE ADVISORY IN PLACE. SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EARLY EVENING HAVE THE POTENTIAL TO PRODUCE STRONG WIND GUSTS...HEAVY RAIN AND HAIL. SHOWERS AND ISOLATED THUNDERSTORMS WILL BE ONGOING INTO THE START OF THE WORK WEEK. WINDS WILL SHIFT FROM THE SW TO THE NW BY MONDAY EVENING AS A COLD FRONT CROSSES. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ530>543. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
738 AM EDT SUN JUN 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 520 AM EDT SUN JUN 2 2013 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM NW ONTARIO INTO THE CNTRL GREAT LAKES. A SHORTWAVE SUPPORTING OVER NRN LAKE MICHIGAN INTO NW LOWER MI SUPPORTED AN AREA OF RAIN OVER ERN UPPER MI THAT WAS SLOWLY SLIDING OFF TO THE EAST. SCT LIGHT SHOWERS ALSO LINGERED OVER CNTRL UPPER MI. AT THE SFC...A TIGHT GRADIENT BETWEEN LOW PRES OVER LAKE HURON AND A RIDGE INTO THE NRN PLAINS SUPPORTED BRISK NRLY WINDS ACROSS LAKE SUPERIOR INTO THE UPPER MI. UPSLOPE NRLY FLOW INTO THE HIGHER TERRAIN ALSO SUPPORTED AREAS OF DRIZZLE. MUCH COLDER AIR HAS MOVED INTO THE REGION WITH TEMPS DROPPING INTO THE UPPER 30S AND LOWER 40S. TODAY...ALTHOUGH THE NAM AND HIGH RES MODELS SHOW LOW LEVEL DRYING WILL SPREAD THROUGH MOST OF THE CWA THIS MORNING...UPSTREAM CLOUDS TRENDS SUGGEST THAT THE CLEARING TREND MAY BE SLOWER. ANY LINGERING LIGHT SHOWERS OR DRIZZLE SHOULD END BY MID OR LATE MORNING WITH CLEARING FROM WEST TO EAST BY EARLY TO MID AFTERNOON. EVEN WITH SUNSHINE...WITH N FLOW ACROSS LAKE SUPERIOR AND 850 MB TEMPS NEAR -1C...TEMPS WILL STRUGGLE INTO THE UPPER 40S TO LOWER 50S NORTH AND INTO THE MID AND UPPER 50S SOUTH. TONIGHT...SFC HIGH PRES BUILDING INTO THE REGION FROM THE WEST SUNDAY NIGHT WILL RESULT IN IDEAL RADIATIONAL COOLING CONDITIONS OVER THE WESTERN INTERIOR OF THE CWA WHERE MIN TEMPS WILL LIKELY FALL INTO LOWER 30S...NEAR THE LOWER END OF GUIDANCE. SOME TRADITIONAL COLD SPOTS COULD ALSO SEE READINGS INTO THE UPPER 20S. SO...A FROST ADVISORY WAS ISSUED FOR INLAND PORTIONS OF THE WEST HALF OF UPPER MICHIGAN. A VORTEX DESCENDING FROM NRN ONTARIO IS EXPECTED TO GRAZE NE LAKE SUPERIOR. ALTHOUGH PCPN AND CLOUDS WITH THIS FEATURE ARE EXPECTED TO REMAIN THE NE OF THE CWA...THE VORTEX WILL RESULT IN NW WINDS STRONG ENOUGH TO MAINTAIN SOME BOUNDARY LAYER MIXING AND PREVENT TEMPS FROM DROPPING OFF AS FAR AS IN THE WEST. LOOK FOR MAINLY MID TO UPPER 30S MIN TEMPS OVER THE EAST HALF. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 343 AM EDT SUN JUN 2 2013 UPPER TROUGH THAT IS CURRENTLY AFFECTING THE UPPER GREAT LAKES EARLY THIS MORNING WILL BE SHIFTING EAST THROUGH EASTERN CANADA ON MONDAY. THIS WILL LEAD TO THE AREA BEING UNDER NORTHWEST FLOW ALOFT AND A SURFACE HIGH PRESSURE RIDGE FROM A HIGH CENTERED IN SOUTH CENTRAL CANADA. WITH DRY LOW AND MID LEVELS UNDER THE HIGH PRESSURE RIDGE...EXPECT A MOSTLY SUNNY SKY ACROSS MUCH OF THE LAND AREA. THERE COULD BE SOME LINGERING CLOUDS OVER NORTHEAST LAKE SUPERIOR AND FAR EASTERN UPPER MICHIGAN AS THE UPPER TROUGH DEPARTS. WITH THE SUNSHINE...EXPECT MIXING TO AROUND 850-825MB. BUT WITH TEMPERATURES AT THAT LEVEL ONLY AROUND 2C WEST AND -1C EAST...BELOW NORMAL HIGHS ARE EXPECTED AND ONLY IN THE 50S AND LOWER 60S. THE COOLEST TEMPERATURES WILL BE ALONG THE GREAT LAKES SHORELINES DUE TO LAKE BREEZES. THE OTHER ITEM TO MENTION FOR MONDAY WILL BE LOW RH VALUES. ML DEWPOINTS FROM THE MODELS INDICATE VALUES IN THE MID 20S OVER THE INTERIOR LOCATIONS AND POTENTIALLY THE UPPER TEENS IF THE GFS IS CORRECT. WITH THAT CONSISTENCY AND THE TRENDS IN THE MAV/MET...HAVE LOWERED OUR DEWPOINTS A GOOD 5-7 DEGREES. THIS PRODUCES RH VALUES OF 25-35 PERCENT OVER THE INLAND AREAS...WITH THE LOWEST VALUES OVER THE WEST. FORTUNATELY...THE WET WEATHER RECENTLY...GREEN UP WELL ON IT/S WAY OR EVEN DONE...AND BELOW NORMAL TEMPERATURES REDUCES FIRE WEATHER CONCERNS EVEN WITH 10-15KT WINDS. THE HIGH PRESSURE RIDGE WILL STILL BE OVER THE AREA ON MONDAY NIGHT AS AN UPPER RIDGE SLIDES ACROSS THE AREA. THE CLEAR SKIES...LIGHT WINDS...AND PWAT VALUES AROUND 30-40 PERCENT OF NORMAL WILL LEAD TO A COLD NIGHT ACROSS THE AREA. WILL CONTINUE THE TREND OF GOING BELOW GUIDANCE VALUES AND HAVE LOWS AROUND 30 OVER THE INTERIOR LOCATIONS. RECORD LOWS FOR JUNE 4 ARE IN THE MID-UPPER 20S...SO WE WILL BE CLOSE BUT LIKELY STAY ABOVE THE RECORD LOWS. WILL ALSO CONTINUE THE MENTION OF FROST FOR MONDAY NIGHT ALONG WITH HIGHLIGHTING IN HWO. AREA WILL STILL BE UNDER THE INFLUENCE OF THE HIGH ON TUESDAY...AS IT DRIFTS SOUTHEAST ACROSS THE CWA THROUGH THE DAY. THIS WILL LEAD TO LIGHTER WINDS ACROSS THE AREA. DO EXPECT TO SEE SOME HIGH CLOUDS STREAMING EAST ACROSS THE WESTERN CWA DURING THE AFTERNOON AHEAD OF THE NEXT SYSTEM APPROACHING THE AREA. HIGHS WILL BE A LITTLE WARMER ON TUESDAY...AS 850MB TEMPS WARM A COUPLE DEGREES FROM MONDAY. WITH THE RIDGE LINGERING OVER THE EAST...HAVE LOWERED TD VALUES SIGNIFICANTLY OVER THE EAST HALF. THIS WILL LIKELY LEAD TO ANOTHER LOW RH DAY...BUT AS WITH MONDAY...FIRE WX CONCERNS ARE LIMITED WITH EVEN LIGHTER WINDS. THE UPPER TROUGH CURRENTLY OVER BRITISH COLUMBIA WILL BE MOVING THROUGH THE NORTHERN PLAINS ON TUESDAY AND THEN BECOME CLOSE ENOUGH TO START INFLUENCING THE UPPER GREAT LAKES FOR TUESDAY NIGHT AND CONTINUING INTO THURSDAY. THERE ARE STILL QUESTIONS ON THE EXACT TRACK OF THE SHORTWAVE TROUGH...WHICH IN TURN AFFECTS THE LOCATION OF THE SURFACE LOW AND RESULTANT WARM AIR ADVECTION PRECIPITATION. LATEST IDEA FROM THE GFS/ECMWF IS THAT MUCH OF THE INITIAL PRECIPITATION WILL BE WEST OF THE AREA TUESDAY EVENING AND THEN SLIDE OVER THE AREA TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY NIGHT AS THE SURFACE LOW/TROUGH SLIDES FROM THE DAKOTAS INTO SOUTHWEST WISCONSIN. THE WARM AIR ADVECTION IS FAIRLY BROAD AND WEAK...SO WOULD EXPECT THE PRECIPITATION TO BE GENERAL LIGHT SHOWERS. WITH THE BEST FORCING FOCUSED OVER WISCONSIN AND THE SOUTHERN HALF OF THE CWA...HAVE THE HIGHEST POPS IN THAT AREA. SINCE THE BULK OF THE FORCING IS SOUTH OF THE AREA...WILL KEEP POPS IN THE HIGH CHANCE CATEGORY SINCE IT IS ENTIRELY POSSIBLE MUCH OF THE RAIN STAYS IN WISCONSIN. THUNDER CHANCES ARE LIMITED TO NON-EXISTANT...AS SHOWALTER VALUES ARE WELL ABOVE ZERO AND MUCAPE VALUES STAY BELOW 100 J/KG DURING THIS PERIOD. EXPECT A DIMINISHING TREND IN THE PRECIPITATION FOR THURSDAY INTO THURSDAY NIGHT...AS THE DISTURBANCE SHIFTS EAST AND HIGH PRESSURE NEAR HUDSON BAY PUSHES DRIER AIR INTO THE AREA. THIS SHOULD LEAD TO DRY WEATHER FOR FRIDAY...BUT ANOTHER WEAK SHORTWAVE TRIES TO SLIDE EAST ACROSS THE AREA FOR SATURDAY. WITH THE DRY EASTERLY FLOW AND THE POTENTIAL THE HIGH REMAINS IN PLACE...IT/S ARRIVAL MAY BE DELAYED SOME. TEMPERATURES FROM MID WEEK ON WILL CONTINUE THE BELOW NORMAL TREND...WITH HIGHS GENERALLY IN THE 50S-60S AND THE COOLEST DAY ON WEDNESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 738 AM EDT SUN JUN 2 2013 EXPECT IFR CONDITIONS ASSOCIATED WITH AN INFLUX OF SHALLOW COOL...MOIST AIR ON THE HEELS OF GUSTY N WINDS TO IMPROVE TO MVFR NW-SE EARLY THIS MORNING AS DRIER AIR PUSHES INTO THE AREA AHEAD OF HIGH PRES BUIDLING TOWARD UPPER MICHIGAN. AS THIS HIGH MOVES OVERHEAD...CONDITIONS WILL IMPROVE TO VFR...AND THE GUSTY WINDS WILL DIMINISH. HOWEVER...SATELLITE TRENDS SUGGEST THAT THE IMPROVING WILL BE SLOWER THAN PREVIOUS FCST. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 520 AM EDT SUN JUN 2 2013 LOW PRESSURE OVER GEORGIAN BAY WILL SHIFT ENE INTO QUEBEC BY THIS AFTERNOON...WHILE A RIDGE OF HIGH PRESSURE BUILDS OVER NORTHERN ONTARIO. AS A RESULT...NORTH WINDS WILL DIMINISH TODAY. RIDGING WILL EXTEND OVER LAKE SUPERIOR TONIGHT...WHICH WILL REMAIN THROUGH MUCH WEDNESDAY AS THE NEXT LOW WILL SLIDES ACROSS THE NORTHERN PLAINS. THE LOW WILL SHIFT SLOWLY E INTO THE MID MS VALLEY THURSDAY...WHILE THE WEAK RIDGE OF HIGH PRESSURE LINGERS OVER LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FROST ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 8 AM EDT /7 AM CDT/ MONDAY FOR MIZ002-004-005-009>011-084. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
622 AM CDT SUN JUN 2 2013 .AVIATION... 12Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS EXPECTED THRU THE FCST PD. DEE && .PREV DISCUSSION... /ISSUED 302 AM CDT SUN JUN 2 2013/ DISCUSSION... MAIN FORECAST CHALLENGE WAS WHEN TO INCLUDE TSTM CHANCES AS ANOTHER UPPER TROUGH/LOW MOVES FROM SWRN CANADA ACROSS NORTHERN PLAINS THROUGH MIDWEEK. FOR TODAY...UPPER RIDGE AHEAD OF SWRN CANADIAN LOW TO FLATTEN AS IT BUILDS ACROSS CNTRL PLAINS AS UPPER LOW SOUTH OF HUDSONS BAY DROPS SOUTH. PERSISTENT LOW CLOUDS HAVE CLEARED WRN ZONES AS OF 730Z AND SHOULD CONTINUE TO DO SO THROUGH THIS MORNING...ALTHOUGH LATEST RAP SOUNDING DELAYED THIS CLEARING ALONG/E OF MO RIVER TILL AFTERNOON. SLOWED CLEARING DOWN A BIT E...AND FURTHER ADJUSTMENTS MAY BE NEEDED. MILDER TEMPS COMPARED TO SATURDAY BUT STILL BELOW NORMAL AND GENERALLY A DEG OR TWO BELOW GUIDANCE BASED ON PERHAPS HINDERED MIXING FROM MORNING/EARLY AFTN CLOUDS E AND/OR SLIGHTLY COOLER H85 TEMPS PER 00Z ECMWF. UPPER LOW MOVING TOWARD DAKOTAS LATE MONDAY WILL STRENGTHEN LOW LEVEL JET LATE TONIGHT INTO MONDAY NIGHT. THIS WILL PROVIDE INCREASING WINDS...ESPECIALLY MONDAY. HOWEVER...WINDS PROBABLY WILL NOT INCREASE QUICKLY ENOUGH TONIGHT TO HELP LOWS MUCH WITH GUIDANCE GENERALLY ACCEPTABLE. STORMS THAT DEVELOP TO OUR WEST LATE TONIGHT AIDED BY THETA E ADVECTION IN LOW LEVEL JET AXIS COULD MOVE ACROSS SECTIONS OF THE AREA MONDAY MORNING...FOR NOW CONFINED SLGT CHC POPS TO FAR N. OTHERWISE KEPT MONDAY AFTN DRY. BOOSTED WIND SPEEDS MONDAY TO JUST BELOW WIND ADVISORY CRITERIA NWRN ZONES. MAX TEMPERATURES PROBABLY A CATEGORY OR SO WARMER MOST AREAS LOOKS FINE. INCREASING POPS MONDAY NIGHT INTO TUESDAY STILL ON TRACK AS UPPER LOW SHIFTS SE A BIT AND LOW LEVEL JET/CONVERGENCE SHIFTS INTO THE FORECAST AREA MONDAY NIGHT FOLLOWED BY A COLD FRONT TUESDAY. ALTHOUGH SOME ADJUSTMENTS WERE MADE AND MORE WILL PROBABLY BE ADDRESSED IN LATER FORECASTS...IT APPEARS HIGHER POPS WILL BE SHIFTING TOWARD ERN ZONES THRU LATE TUESDAY. IF CLOUDS/SHOWERS REMAIN WIDESPREAD TUE MAX TEMPS MAY NEED LOWERING. CONFIDENCE IS LOW IN HOW SCENARIO TUE NIGHT/WED PLAYS OUT AS A WAVE ROTATING AROUND UPPER LOW COULD HELP GENERATE MCS TO OUR WSW IN UPSLOPE REGION ACROSS WRN HIGH PLAINS BY WED AM. SOME OF THIS ACTIVITY COULD SKIRT AREA WED...SPCLY SOUTH...AND LOW CHC POPS WERE CARRIED GENERALLY ALONG/S OF HIGHWAY 30. HOWEVER...WE COULD ALSO SEE JUST MAINLY CLOUDS FROM THIS...BUT EITHER PRECIP OR CLOUDS COULD IMPACT HIGHS. FOR NOW THEY WERE KEPT IN THE 70S TUE AND WED. THURSDAY LOOKED DRY WITH INCREASING TSTM CHANCES AGAIN FROM W TO E FRIDAY INTO SATURDAY AS NEXT TROUGH APPROACHES. NO CHANGES MADE FROM MODEL/PREVIOUS FORECAST BLEND. CHERMOK && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ 99/99
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1140 AM EDT SUN JUN 2 2013 .SYNOPSIS... A COLD FRONT WILL PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS TODAY ACROSS THE NORTH COUNTRY. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCE STRONG AND DAMAGING WINDS...SMALL HAIL...AND LOCALIZED HEAVY DOWNPOURS. CLEARING AND COOLER TEMPERATURES WILL ARRIVE BY THE START OF THE WORK WEEK. && .NEAR TERM /UNTIL 11 PM THIS EVENING/... AS OF 1138 AM EDT SUNDAY...UPDATED ZNS TO REFLECT SVR THUNDERSTORM WATCH #271 FOR EASTERN DACKS THRU VT UNTIL 8 PM THIS EVENING. REST OF FCST IN GREAT SHAPE. UPDATED FCST TO MENTION SHOWERS/STORMS THRU THIS MORNING FOR CENTRAL/NORTHERN VT AND REMOVED MENTION OF ENHANCED WORDING THRU THE MORNING HOURS. ALSO...ADJUSTED TEMPS/DWPTS BASED ON CRNT OBS. FCST CHALLENGE IS TIMING OF CONVECTION TODAY...FOLLOWED BY AREAL COVERAGE/INTENSITY OF STORMS THIS AFTN. WATER VAPOR SHOWS POTENT S/W ENERGY ACRS THE EASTERN GREAT LAKES...WITH ENHANCED RIBBON OF DEEP LAYER MOISTURE AHEAD OF THIS ENERGY ACRS WESTERN NY/PA. IN ADDITION...STRONG HGHT FALLS ARE OCCURRING AS MID/UPPER LVL TROF LIFTS TWD HUDSON`S BAY THIS AFTN AND ASSOCIATED SFC BOUNDARY SWINGS ACRS OUR CWA. AT THE SFC...INITIAL PRE-FRNTAL TROF HAS PRODUCED SHOWERS WITH A FEW EMBEDDED RUMBLES OF THUNDER ACRS THE EASTERN DACKS INTO NORTHERN/CENTRAL VT THIS MORNING. EXPECT SOME CLRING BEHIND THIS INITIAL TROF...WHICH WL AID SFC HEATING. WITH TEMPS WARMING TO NEAR 80F...AND DWPTS IN THE U60S TO L70S...SFC BASED CAPE VALUES WL BE BTWN 2000-2500 J/KG...ESPECIALLY ALONG AND EAST OF THE CPV. EXPECT ANOTHER ROUND OF STORMS TO REDEVELOP BY EARLY THIS AFTN ACRS THE EASTERN DACKS...AND BECOME SEVERE AS THEY ENCOUNTER BETTER INSTABILITY/SHEAR ACRS THE CPV AND MOST OF VT. SOUNDINGS SHOW A MAINLY UNIDIRECTIONAL WIND FLW THRU 500MB...SUPPORTING LINES OF STORMS WITH INDIVIDUAL BOW SEGMENTS POSSIBLE...WITH PRIMARY THREAT BEING STRONG/DAMAGING WINDS. PRE-STORM CHECKLIST SHOWS VERY HIGH 0C LINE AROUND 13KFT THIS AFTN...WHICH INDICATES WE WOULD NEED A 50 TO 55 DBZ TO 35,000 FEET FOR SEVERE HAIL. THEREFORE PRIMARY THREAT WL BE WINDS...AND GIVEN RECENT SATURATED SOILS...SHALLOW ROOTED TREES COULD EASILY BE BLOWN DOWN. STORMS SHOULD CLEAR EASTERN VT BY 8 PM THIS EVENING...BASED ON CRNT RAP AND BTV 4KM REFLECTIVITY PROGS. PREVIOUS DISCUSSION...ACTIVE 24-HR PERIOD EXPECTED FOR TODAY/ TONIGHT AS A CD FRNT WILL BEGIN TO PUSH THRU THE AREA. RW/TRW FROM THE OVERNGT PERIOD STILL SLOWLY PUSHING NORTH THRU CANADIAN BORDER ZONES ATTM AND SHOULD CLR INTO QUEBEC BFR MAIN PRECIP ARRIVES WITH FRNT...WHICH IS ONLY TO OUR WEST OVER WESTERN NY/LK ONTARIO. MANY SPOTS IN THE CWA WILL SEE INSTABILITY INCR DURING THE DAY AS PSUNNY/MSUNNY WILL ENSUE BFR CONVECTION BEGINS TO DEVELOP...ALLOWING FOR INCR IN T/TD THROUGHOUT AREA. THIS COMBINED WITH STRONG SHEAR/LAPSE RATES...LI/S NEARING -4 AND MDL CAPE FROM BUFKIT SHOWING 1500-2000 J/KG POTENTIAL...WILL ALLOW FOR DEVELOPMENT OF STRONG TO SEVERE STORMS FOR TODAY/TNGT. SPC(STORM PREDICTION CENTER) HAS MAJORITY OF CWA UNDER SL RISK FOR SEVERE CONDITIONS SO HAVE MAINTAINED SEVERE/ENHANCED WORDING IN FORECAST. MDL PW/S NEARING 1.25-1.60" IN GENERAL WITH LOCALLY HIR AMTS WILL CREATE QPF AMTS IN GENERAL NEARLY AN INCH FOR ALL AREAS...W/ LOCALLY HIR TOTALS IN HEAVIER DOWNPOURS. W/ SOME AREAS SEEING TRAINING OF RW/TRW OVERNGT...HYDRO CONCERNS WILL BE AN ISSUE TO MONITOR. LATEST MDL TREND IS TO BRING BULK OF PRECIP THRU AREA AFTER MIDNGT TONIGHT. MID-LEVEL DRY AIR WORKING AROUND LOW TO OUR WEST MAY AID IN SHUTTING DOWN PRECIP QUICKER. FOR NOW WILL KEEP PRECIP TRENDING DOWN THRU 12Z MONDAY AS TRAINING POTENTIAL MAY KEEP PRECIP GOING ALONG FRNT A BIT LONGER. TEMP THRU PERIOD NEAR GUIDANCE...ESPECIALLY EASTERN ZONES WHERE NOT AFFECTED BY CLD COVER FROM APPORACHING FRNT. && .SHORT TERM /11 PM THIS EVENING THROUGH TUESDAY/... AS OF 424 AM EDT SUNDAY...GOING INTO MONDAY MORNING...MDLS PUSH FRNTL BOUNDARY OFF THE NEW ENGLAND COAST...LEAVING THE CWA WITH A GRADUAL CLRING TREND THRU THE DAY AS SFC HIGH PRESSURE BUILDS EAST OUT OF THE GREAT LKS REGION. OVER PAST SEVERAL MDL RUNS...UPPER TROUGH ASSOCIATED W/ THIS SFC FRNT CONTINUES TO SLOWLY PUSH EAST THRU SOUTHERN PORTIONS OF QUEBEC INTO THE CANADIAN MARITIMES BY TUESDAY. AS A RESULT WILL CONTINUE TO MENTION SL CHANCE FOR -RW FOR NE VT THRU EARLY TUESDAY MORNING BFR CLRING OUT. OVERALL TREND IS FOR NICE WX AS SFC RIDGE REMAINS IN PLACE. STAYING CLOSE TO MDL GUIDANCE FOR TEMPS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 450 AM EDT SUNDAY...ECMWF AND GFS MODELS SHOW A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT AND WILL REMAIN OVER THE REGION THROUGH EARLY THURSDAY...WITH FAIR AND DRY WEATHER EXPECTED. ECMWF AND GFS MODELS SHOW AN UPPER TROUGH OVER THE WESTERN GREAT LAKES EARLY THURSDAY. THIS UPPER TROUGH WILL BRING MOISTURE NORTHEAST FROM THE OHIO VALLEY INTO THE REGION ON THURSDAY AS A STATIONARY FRONTAL BOUNDARY SETS UP ACROSS THE REGION. ECMWF AND GFS MODELS IN GOOD AGREEMENT IN BRINGING RAIN SHOWERS TO THE REGION THURSDAY AND FRIDAY. ECMWF AND GFS MODELS DIFFER ON THE SATURDAY FORECAST WITH THE ECMWF MODEL SHOWING AN UPPER RIDGE BUILDING INTO THE REGION ON SATURDAY...AND ALSO BRINGING A DRIER FORECAST TO THE REGION FOR SATURDAY. GFS MODEL STILL HAS AN UPPER TROUGH OVER THE REGION ON SATURDAY WITH A CHANCE OF RAIN SHOWERS. GIVEN MODEL DIFFERENCES...WILL OPT TO STAY WITH PREVIOUS CONTINUITY AND KEEP A CHANCE OF RAIN SHOWERS OVER THE REGION ON SATURDAY. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... THROUGH 12Z MONDAY...AREAS OF MVFR/IFR EXPECTED IN SHOWERS AND THUNDERSTORMS THROUGH 00Z MONDAY. SOME THUNDERSTORMS TODAY MAY BECOME SEVERE WITH GUSTY WINDS AND HAIL POSSIBLE. COMPOSITE RADAR LOOP AS OF 1130Z SUNDAY SHOWING SOME SHOWERS WITH SOME EMBEDDED THUNDERSTORMS ACROSS THE SAINT LAWRENCE VALLEY IN NORTHERN NEW YORK AT THIS TIME. EXPECTING STRONG TO POSSIBLE SEVERE THUNDERSTORMS TO DEVELOP ACROSS THE SAINT LAWRENCE VALLEY IN NORTHERN NEW YORK AROUND 14Z-18Z TODAY...AND THEN SHIFT EASTWARD. EXPECTING SHOWER AND THUNDERSTORM ACTIVITY COMING TO AN END IN THE SAINT LAWRENCE VALLEY IN NORTHERN NEW YORK BY 18Z SUNDAY. EXPECTING WIDESPREAD STRONG TO SEVERE THUNDERSTORMS TO DEVELOP ACROSS THE REMAINDER OF THE REGION FROM 16Z-21Z SUNDAY. A MID LEVEL DRY SLOT WILL MOVE INTO THE REGION LATE THIS AFTERNOON...SO EXPECTING ANY THUNDERSTORM ACTIVITY TO BE CONFINED TO EASTERN AND SOUTHERN VERMONT BY 00Z MONDAY. EXPECTING ANY THUNDERSTORM ACTIVITY WILL BE EAST OF THE REGION BY 03Z MONDAY. OUTLOOK 12Z MONDAY THROUGH THURSDAY... 12Z MONDAY THROUGH THURSDAY...MAINLY VFR CONDITIONS EXPECTED THROUGH THURSDAY. && .HYDROLOGY... SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON WITH POTENTIAL FOR LOCALIZED HEAVY RAINFALL. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING 1 TO 2 INCHES OF RAIN IN A SHORT PERIOD OF TIME...WHICH MAY CAUSE ISOLATED FLASH FLOODING...ESPECIALLY IN THE TRRN. ALSO...MINOR URBAN AND LOW LYING FLOODING WILL BE POSSIBLE...WITH THESE THUNDERSTORMS. INDIVIDUAL THUNDERSTORMS WILL MOVE FROM SOUTHWEST TO NORTHEAST AT 20 TO 30 MPH...WITH THE ENITRE BROKEN LINE SLOWLY MOVING EAST AT 10 TO 15 MPH. && .MARINE... A LAKE WIND ADVISORY CONTINUES FOR TODAY...EXPECT SOUTH WINDS TO INCREASE AT 15 TO 25 KNOTS WITH WAVES 1 TO 3 FEET. IN ADDITION...LAKE THUNDERSTORM ADVISORY CONTINUES WITH THE EXPECTATION THUNDERSTORMS WILL DEVELOP OVER THE CHAMPLAIN VALLEY AND OPEN WATERS BY EARLY THIS AFTERNOON. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JN NEAR TERM...TABER SHORT TERM...JN LONG TERM...WGH AVIATION...WGH/RJS HYDROLOGY... MARINE...
AREA FORECAST DISCUSSION
NWS PENDLETON OR
855 AM PDT SUN JUN 2 2013 .UPDATE...MINOR UPDATES WERE MADE TO THE CURRENT FORECAST. A LARGE UPPER LEVEL TROUGH OVER WA/ID/MT WILL PUSH AN EMBEDDED WAVE OVER SE WASHINGTON AND NE OREGON THIS AFTERNOON. THERE IS LIMITED MOISTURE WITH THE APPROACHING DISTURBANCE...BUT A 100 KNOT JET ALONG THE BOTTOM OF THE TROUGH WILL RESULT IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM THE TRI-CITIES, PENDLETON, AND UKIAH EAST TO THE IDAHO BORDER. BASED UPON THE HRRR COMPOSITE REFLECTIVITY SHOWING CONVECTIVE CELLS ACROSS THE WASHINGTON COLUMBIA BASIN...THE FORECAST WAS UPDATED TO EXTEND ISOLATED THUNDERSTORMS FARTHER WEST TO INCLUDE THE EASTERN PORTION OF THE LOWER COLUMBIA BASIN. THERE MAY BE A FEW STRONG THUNDERSTORMS TODAY WITH DIME TO PENNY-SIZE HAIL...BUT SEVERE STORMS ARE NOT EXPECTED. A FAIRLY TIGHT SURFACE PRESSURE GRADIENT AND A WEAK MARINE PUSH WILL RESULT IN 20-30 MPH WINDS THROUGH THE EASTERN SIDE OF THE COLUMBIA RIVER GORGE AND THE KITTITAS VALLEY. THE SYSTEM WILL HAVE VERY LITTLE IMPACT IN OUR SOUTHERN ZONES...THEREFORE IT WILL BE MOSTLY SUNNY AND A LITTLE BREEZY ACROSS CENTRAL OREGON TODAY. THE SYSTEM WILL EXIT THE REGION THIS EVENING WITH MOST SHOWERS ENDING BY MIDNIGHT. WISTER && .PREV DISCUSSION... /ISSUED 431 AM PDT SUN JUN 2 2013/ LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...HIGH PRESSURE WILL BUILD OVER THE AREA FOR THE EXTENDED. EXPECT MOSTLY DRY CONDITIONS AND TEMPERATURES TO INCREASE THROUGH THE WORK WEEK...INTO THE WEEKEND. EXPECT TEMPERATURES TO BE IN THE MID 80S TO LOWER 90S ACROSS THE LOWER ELEVATIONS...WITH 70S TO LOWER 80S MOUNTAINS. MODELS DO INDICATE A FEW WEAK DISTURBANCES THAT MAY PASS IN THE EXTENDED...BUT ONLY ANTICIPATE OCCASIONAL BREEZY CONDITIONS AND BRIEF INCREASED CLOUD COVER TO BE ASSOCIATED. WEBER AVIATION...12Z TAFS...VFR CONDITIONS TO PREVAIL OVER THE NEXT 24 HOURS. SCATTERED CLOUDS AT 5-8 THOUSAND FEET TODAY WITH WINDS INCREASING IN THE AFTERNOON AT 10-20 KT FROM THE NW WITH A FEW HIGHER GUSTS. WINDS AND CLOUD COVER WILL DIMINISH AFTER 06Z TONIGHT. WEBER && .PRELIMINARY POINT TEMPS/POPS... PDT 73 48 75 50 / 10 10 0 0 ALW 74 53 77 55 / 20 20 0 0 PSC 79 51 80 53 / 10 10 0 0 YKM 78 47 79 49 / 10 10 0 0 HRI 77 50 79 52 / 10 10 0 0 ELN 74 48 79 50 / 10 10 0 0 RDM 72 37 77 39 / 10 10 0 0 LGD 69 44 72 46 / 20 20 10 10 GCD 67 43 70 45 / 10 10 0 0 DLS 77 52 80 54 / 10 10 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && THREAT INDEX TODAY : GREEN MONDAY : GREEN TUESDAY : GREEN GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES. YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 85/93
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1034 AM EDT SUN JUN 2 2013 .SYNOPSIS... WARM MOIST AIR OVER OUR REGION WILL BE DISPLACED BY A COLD FRONT TODAY. BEHIND THE FRONT AN UPPER TROUGH WILL DOMINATE OUR REGION WITH GENERALLY COOLER AND DRIER CONDITIONS PREVAILING THROUGH MID WEEK. WET WEATHER WILL RETURN FOR LATE WEEK AS A NEW WEATHER SYSTEM APPROACHES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A LINE OF CONVECTION /STILL MAINLY JUST SHOWERS AT 14Z/ CONTINUES TO MOVE INTO CENTRAL ZONES. BIGGEST QUESTION FOR TODAY IS IF THE CONVECTION CAN ATTAIN ANY MEASURE OF ORGANIZATION AHEAD OF APPROACHING COLD FRONT. SHORTWAVE /FROM KY LAST NIGHT/ IS CURRENTLY SLIDING ACROSS CWA AND SOME ENHANCEMENT TO CONVECTION IS BEING SEEN...THOUGH STILL JUST ENOUGH TO PRODUCE A FEW BOLTS OF LIGHTNING. THIS FEATURE WILL SLIDE NE...BECOMING A DIMINISHING FACTOR IN TODAY/S WEATHER BY 18Z. SO...POTENTIAL FOR STRONGER STORMS MAY COME DOWN TO HEATING OVER EASTERN SECTIONS. MID-LEVEL CLOUDS CURRENTLY STREAMING OVERHEAD THOUGH...BUT POTENTIAL FOR THIS AREA TO BREAK OUT INTO THE SUN THIS AFTERNOON BEHIND EXITING SHORTWAVE SHOULD ALLOW CAPES TO RISE TO AROUND 1500. SPC DOES HAVE SE HALF OF FCST AREA OUTLOOKED FOR A SLIGHT RISK OF SEVERE STORMS AS MID-LEVEL TROUGH AND COLD FRONT ROTATE THROUGH LATER TODAY. AND HRRR STILL ATTEMPTS TO INITIATE AND ORGANIZE A LINE OF CONVECTION AFTER 16Z ALONG PRE-FRONTAL TROUGH...BUT AFOREMENTIONED FEATURES MAY HAVE TO COME TOGETHER JUST RIGHT FOR A STRONGER TSTM LINE TO HAPPEN BEFORE EXITING CWA TO THE EAST. FOR NOW...WILL KEEP ENHANCED WORDING GOING IN EASTERN SECTIONS AND SEE HOW THIS ALL PLAYS OUT. OTHERWISE...IT WILL BE ANOTHER WARM MUGGY DAY WITH HIGH TEMPS SLIGHTLY COOLER THAN IN PREVIOUS DAYS DUE TO SHOWERS AND CLOUD COVER. THIS SHOULD BE THE LAST WIDESPREAD VERY WARM AND HUMID DAY FOR A WHILE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... STILL SOME UNCERTAINTY AMONG THE SHORT RANGE OPERATIONAL MODELS AS TO THE TIMING OF THE FRONT THRU SERN PA LATER TONIGHT INTO EARLY MONDAY. THE NAM IS THE SLOWEST WITH A WAVY FEATURE STILL STUCK OVER SERN PA INTO EARLY MONDAY...WHILE THE GFS AND ECMWF HAVE THE SURFACE FRONT ANYWHERE FROM THE CENTRAL DEL MARVA AREA TO NORTHERN NJ. THE GEFS AND SREF FOLLOW THEIR OPERATIONAL COUNTERPARTS PRETTY CLOSELY SO ONCE AGAIN I HAD TO SPLIT THE DIFFERENCE AND KEPT THE SMALL MENTION OF SHOWERS GOING INTO MONDAY MORNING. I DID DRY THINGS OUT THEREAFTER BUT THE 06Z NAM STILL LEANS TOWARD THE 00Z SOLUTION OF A SLOWER WAVY FRONT...SO LATER SHIFTS MAY HAVE TO ADJUST THIS A BIT. DRIER AND COOLER AIR WILL MOVE IN FROM THE NW OVERNIGHT AND MONDAY WITH THE LAST OF THE 60S DEWPOINTS BEING SHOVED OFF TO THE SE IN TIME. HOW FAST THEY EXIT THE REGION ALTOGETHER WILL DEPEND ON THE FRONT MENTIONED ABOVE. HIGHS MONDAY WILL BE IN THE CHILLY 60S OVER THE NW...WELL BELOW NORMAL FOR EARLY JUNE. HIGHS NEAR 80 IN THE SE WILL BE VERY NEAR NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE BUILDING DOWN OUT OF THE GR LAKES SHOULD PROVIDE FOR SOME DRY UNEVENTFUL WEATHER TUESDAY WITH PLEASANT TEMPS AND HUMIDITY. AS THE HIGH MOVES OFF TO OUR NORTHEAST WE SHOULD SET UP A SOUTHERLY FLOW OF INCREASING MOIST AIR. MEANWHILE THE MODELS WANT TO CARVE OUT A BROAD SLOW-MOVING UPPER TROUGH OVER THE EASTERN US SUGGESTING A PROLONGED PERIOD OF UNSETTLED WEATHER SETTING UP FROM ABOUT MID WEEK...POSSIBLY INTO NEXT WEEKEND. I REINTRODUCED THE CHANCES FOR RAIN BY WEDNESDAY AND KEPT THE MENTION OF SHOWERS RIGHT INTO SUNDAY. THE EXPECTED DEVELOPMENT OF A NEGATIVE NAO COULD SIGNAL THIS EASTERN TROUGH STICKING AROUND FOR A WHILE WITH THE GEFS SHOWING AN ANOMALOUS TROUGH DEVELOPING INTO THE LOWER GR LAKES OUT AS FAR AS DAY 7. OF NOTE IS SOME TROPICAL MOISTURE OVER THE BAY OF CAMPECHE. THE NHC SAYS IT HAS NO CHANCE OF TURING INTO A TROPICAL CYCLONE OVER THE NEXT COUPLE OF DAYS...BUT THE VARIOUS OPERATIONAL MODELS SEEM TO WANT TO DRAG AT LEAST SOME OF THE MOISTURE NORTHWARD. AS USUAL THERE IS NO AGREEMENT ON THE FINE DETAILS WITH THE GFS TAKING THE SLUG OF MOISTURE OFF THE SERN US COAST...THE ECMWF TAKING THINGS A FAIR DISTANCE UP THE COAST AND THE CANADIAN TAKING A FULL BLOWN TROPICAL CYCLONE INTO THE CENTRAL APPALACHIANS BY FRIDAY. COULD BE AN INTERESTING END OF THE WEEK. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... COLD FRONT WILL APPROACH FROM THE WEST LATER TODAY. BEFORE IT ARRIVES...SEVERAL BANDS OF SHOWERS AND ISOLATED STORMS TO WORK ACROSS THE AREA TODAY. VFR FOR MANY SPOTS TODAY...BUT A BAND OF MVFR LIKELY WITH EASTWARD ADVANCING LINE OF CONVECTION. PARTIAL CLEARING INTO THE SE BY MID AFTERNOON...WITH POTENTIAL FOR STRONGER LINE OF TSTMS TO FORM AND POSS IMPACT KIPT-KSEG-KMDT- KLNS-KTHV THIS AFTERNOON WITH SHORT-LIVED BUT VERY RESTRICTIVE CONDITIONS ALONG WITH LOCALLY GUSTY WINDS. OUTLOOK... MON...LOW CIGS/FOG POSS EARLY OVR W MTNS. TUE-WED...NO SIG WX EXPECTED. THU...ISOLD PM THUNDERSTORM IMPACTS POSS W MTNS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/RXR NEAR TERM...LA CORTE/RXR SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
740 AM EDT SUN JUN 2 2013 .SYNOPSIS... WARM MOIST AIR OVER OUR REGION WILL BE DISPLACED BY A COLD FRONT TODAY. BEHIND THE FRONT AN UPPER TROUGH WILL DOMINATE OUR REGION WITH GENERALLY COOLER AND DRIER CONDITIONS PREVAILING THROUGH MID WEEK. WET WEATHER WILL RETURN FOR LATE WEEK AS A NEW WEATHER SYSTEM APPROACHES. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A LINE OF CONVECTION CONTINUES TO MOVE ACROSS MY NW MOUNT IAN ZONES. THE MOST ORGANIZED ACTIVITY IS UP IN NY STATE...WITH THE LINE BECOMING PROGRESSIVELY MORE RAGGED LOOKING DOWN INTO SWRN PA. BIGGEST QUESTION FOR TODAY IS IF THE CONVECTION CAN ATTAIN ANY MEASURE OF ORGANIZATION AS THE FRONT ENTERS THE REGION. SPS HAS MUCH OF THE FCST AREA OUTLOOKED FOR A SLIGHT RISK OF SEVERE STORMS...BUT AS USUAL MUCH WILL DEPEND ON HEATING. SHORT RANGE HIGH RES GUIDANCE IS HAVING A HARD TIME GRASPING THE MODE OF CONVECTION THAT WE CAN EXPECT WITH THE FRONT. THE RAP SHOWS DISORGANIZED SHOWERS/STORMS WHILE THE HRRR HAS MORE OF A LINEAR LOOKING FEATURE DEVELOPING OVER CENTRAL PA BY MID MORNING...BUT CURIOUSLY WEAKENS THE LINE AS IT MOVES EAST DURING WHAT SHOULD BECOME THE MOST UNSTABLE PART OF THE DAY. THIS DOES A LOT TO LOWER CONFIDENCE IN TRYING TO TIME THE BEST CHANCES FOR RAIN AND STORMS TODAY. AS FOR POPS...I ENDED UP GOING WITH A GMOS/SREF COMPROMISE AND HAVE A LIKELY CHANCE OF SHOWERS AND THUNDER FOR MOST OF THE AREA THIS MORNING INTO THIS AFTERNOON...BUT TIMING IS TOUGH. IT WILL BE ANOTHER WARM MUGGY DAY WITH SLIGHTLY COOLER HIGH TEMPS DUE TO SHOWERS AND CLOUD COVER. THIS SHOULD BE THE LAST WIDESPREAD VERY WARM AND HUMID DAY FOR A WHILE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... STILL SOME UNCERTAINTY AMONG THE SHORT RANGE OPERATIONAL MODELS AS TO THE TIMING OF THE FRONT THRU SERN PA LATER TONIGHT INTO EARLY MONDAY. THE NAM IS THE SLOWEST WITH A WAVY FEATURE STILL STUCK OVER SERN PA INTO EARLY MONDAY...WHILE THE GFS AND ECMWF HAVE THE SURFACE FRONT ANYWHERE FROM THE CENTRAL DEL MARVA AREA TO NORTHERN NJ. THE GEFS AND SREF FOLLOW THEIR OPERATIONAL COUNTERPARTS PRETTY CLOSELY SO ONCE AGAIN I HAD TO SPLIT THE DIFFERENCE AND KEPT THE SMALL MENTION OF SHOWERS GOING INTO MONDAY MORNING. I DID DRY THINGS OUT THEREAFTER BUT THE 06Z NAM STILL LEANS TOWARD THE 00Z SOLUTION OF A SLOWER WAVY FRONT...SO LATER SHIFTS MAY HAVE TO ADJUST THIS A BIT. DRIER AND COOLER AIR WILL MOVE IN FROM THE NW OVERNIGHT AND MONDAY WITH THE LAST OF THE 60S DEWPOINTS BEING SHOVED OFF TO THE SE IN TIME. HOW FAST THEY EXIT THE REGION ALTOGETHER WILL DEPEND ON THE FRONT MENTIONED ABOVE. HIGHS MONDAY WILL BE IN THE CHILLY 60S OVER THE NW...WELL BELOW NORMAL FOR EARLY JUNE. HIGHS NEAR 80 IN THE SE WILL BE VERY NEAR NORMAL. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... HIGH PRESSURE BUILDING DOWN OUT OF THE GR LAKES SHOULD PROVIDE FOR SOME DRY UNEVENTFUL WEATHER TUESDAY WITH PLEASANT TEMPS AND HUMIDITY. AS THE HIGH MOVES OFF TO OUR NORTHEAST WE SHOULD SET UP A SOUTHERLY FLOW OF INCREASING MOIST AIR. MEANWHILE THE MODELS WANT TO CARVE OUT A BROAD SLOW-MOVING UPPER TROUGH OVER THE EASTERN US SUGGESTING A PROLONGED PERIOD OF UNSETTLED WEATHER SETTING UP FROM ABOUT MID WEEK...POSSIBLY INTO NEXT WEEKEND. I REINTRODUCED THE CHANCES FOR RAIN BY WEDNESDAY AND KEPT THE MENTION OF SHOWERS RIGHT INTO SUNDAY. THE EXPECTED DEVELOPMENT OF A NEGATIVE NAO COULD SIGNAL THIS EASTERN TROUGH STICKING AROUND FOR A WHILE WITH THE GEFS SHOWING AN ANOMALOUS TROUGH DEVELOPING INTO THE LOWER GR LAKES OUT AS FAR AS DAY 7. OF NOTE IS SOME TROPICAL MOISTURE OVER THE BAY OF CAMPECHE. THE NHC SAYS IT HAS NO CHANCE OF TURING INTO A TROPICAL CYCLONE OVER THE NEXT COUPLE OF DAYS...BUT THE VARIOUS OPERATIONAL MODELS SEEM TO WANT TO DRAG AT LEAST SOME OF THE MOISTURE NORTHWARD. AS USUAL THERE IS NO AGREEMENT ON THE FINE DETAILS WITH THE GFS TAKING THE SLUG OF MOISTURE OFF THE SERN US COAST...THE ECMWF TAKING THINGS A FAIR DISTANCE UP THE COAST AND THE CANADIAN TAKING A FULL BLOWN TROPICAL CYCLONE INTO THE CENTRAL APPALACHIANS BY FRIDAY. COULD BE AN INTERESTING END OF THE WEEK. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... MAIN BATCH OF STORMS MOVED ACROSS NW PA OVERNIGHT...IN THE AREA WITH THE STRONGER LLJ. SEVERAL BANDS OF SHOWERS AND ISOLATED STORMS TO WORK ACROSS THE AREA TODAY. VFR FOR MANY SPOTS TODAY...BUT IFR AND MVFR AT TIMES...ESPECIALLY BFD AND JST THIS MORNING. PARTIAL CLEARING INTO THE SE BY LATE AFTERNOON...BUT WEAK WAVE MAY BRING SOME LOWER CIGS AND SHOWERS TO THE SE TONIGHT. OUTLOOK... MON...LOW CIGS/FOG POSS EARLY OVR W MTNS. TUE-WED...NO SIG WX EXPECTED. THU...ISOLD PM THUNDERSTORM IMPACTS POSS W MTNS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1053 AM CDT SUN JUN 2 2013 .UPDATE... SEE MORNING UPDATE. && .DISCUSSION... RAIN HAS PUSHED TO THE COAST AND WILL CONTINUE TO PUSH AWAY FROM SE TX. A WEAK COLD FRONT EXTENDED FROM EL DORADO ARKANSAS TO GALVESTON AND THEN WEST TOWARD COTULLA. DRIER AIR HAS BEGUN TO FILTER INTO SE TX WITH SFC DEW PTS NOW IN THE MID/UPPER 60S. CONSIDERABLE CLOUD COVER AND WET GROUND WILL LIKELY LIMIT HEATING TODAY SO HAVE TRIMMED MAX TEMPS A FEW DEGREES. CLOUDS SHOULD BEGIN TO ERODE IN THE NEXT HOUR OR SO AND PLENTY OF SUNSHINE IS STILL EXPECTED BY LATE AFTERNOON. RAP MODEL SHOWS SOME REDVELOPMENT ALONG THE COAST LATE THIS AFTERNOON AND WILL LEAVE 20 POPS IN TO ACCOUNT FOR THE POSSIBILITY. NEW ZONES OUT BY 11 AM. 43 && .PREV DISCUSSION... /ISSUED 655 AM CDT SUN JUN 2 2013/ DISCUSSION... 12Z AVIATION DISCUSSION. AVIATION... A LINE OF STRONG TO SEVERE THUNDERSTORMS WILL MOVE THROUGH THE HOUSTON METRO AREA BETWEEN 12 AND 16Z THIS MORNING...AND OFF THE COAST BETWEEN 14 AND 18Z. WINDS MAY BRIEFLY GUST FROM THE NORTH AT 25 TO 25 KNOTS WITH VISIBILITIES DROPPING TO 1 MILE IN HEAVY RAIN. CONDITIONS SHOULD GRADUALLY IMPROVE BEHIND THE LINE WITH ALL TERMINALS VFR BY THIS AFTERNOON. SKIES SHOULD CLEAR OUT OVERNIGHT WITH LIGHT NORTHERLY WINDS. 44 PREV DISCUSSION... /ISSUED 445 AM CDT SUN JUN 2 2013/ DISCUSSION... A LINE OF THUNDERSTORMS IS BEGINNING TO FILL IN FROM SOUTH OF LUFKIN TO COLLEGE STATION. RAIN GAUGES IN TRINITY COUNTY ARE PICKING UP AS MUCH AS 2.2 INCHES IN 3 HRS AND AS MUCH AS 2 INCHES OF THAT HAS FALLEN IN THE LAST HOUR. ALSO SEEING A SIGNS OF A REAR INFLOW JET DEVELOPING IN THE BACK SIDE OF CONVECTION CLOSING IN ON BRYAN/COLLEGE STATION. BASED ON IR IMAGERY SEEMS CLOUD TOPS ARE COOLING MORE SO EXPECT DEEP CONVECTION TO CONTINUE THROUGH THE MORNING. THE MAIN THREAT WILL BE HEAVY RAINFALL ON THE ORDER OF 2 TO 3 INCHES AN HOUR LIKE ALREADY OBSERVED. STORM MOTIONS ARE EXPECTED TO BE SLOW AS IN 10 TO 2O MPH BUT COULD SEE CELLS CONTINUE TO DEVELOP ALONG A FRONT PUSHING INTO THE AREA WHICH COULD TRAIN ACROSS AREAS THAT HAVE ALREADY RECEIVED RAINFALL. SFC ANALYSIS AT 09Z SHOWS FRONTAL BOUNDARY SLOWLY PUSHING SOUTH FROM THE ARLATEX THROUGH C TX INTO THE NW HILL COUNTRY. LOOK FOR CURRENT CONVECTION TO SLOWLY WORK SOUTH AHEAD OF THE FRONT AND POSSIBLY OUT RUN IT BY A GOOD BIT. THE 00Z HIRES-WRF-ARW/TXTECH WRF AND HRRR ALL SHOW CURRENT LINE OF CONVECTION WORKING SOUTH THROUGH SE TX IN A BROKEN LINE. THE LINE THEN WEAKENS AS IT APPROACHES THE COAST BETWEEN 15Z-18Z. DECIDED TO KEEP SOME 50/60 POPS THROUGH 12-15Z AND THEN GRADUALLY DECREASE RAIN CHANCES. LOOKS LIKE THIS PART OF THE FORECAST MAY GO THROUGH ADDITIONAL MODIFICATIONS DEPENDING ON HOW THE CONVECTION EVOLVES THIS MORNING. DO THINK THIS CONVECTION SHOULD WORK OVER AND STABILIZE THE ATMOSPHERE FOR THE AFTERNOON SO 20 POPS FOR THE AFTERNOON LOOKS GOOD BUT IT COULD BE DRY. AS IT HAS BEEN DISCUSSED BEFORE...MAIN HAZARD THIS MORNING WILL BE HEAVY RAINFALL. UPPER LEVEL ANALYSIS SHOWS A TROUGH AXIS WORKING THROUGH THE AREA AND THERE MAY BE ENOUGH UPPER LEVEL SUPPORT TO KEEP CONVECTION GOING THIS MORNING. EXPECT UPPER LEVEL ASCENT TO WEAKEN DURING THE AFTERNOON AND CONVERGENCE ALONG THE FRONT TO WEAKEN AS WELL. THUS BEST CHANCES FOR HEAVY RAIN STILL THIS MORNING AND THREAT DIMINISHING IN THE AFTERNOON. PRECIP WATER VALUES THIS MORNING PEAK INVOF CONVECTION AROUND 1.8-2.0 INCHES AND DECREASE THIS AFTERNOON TO BELOW 1.5 INCHES. AS FOR THE REST OF THE FORECAST...MODELS STILL BRING WEAK FRONT TO THE COAST AND POSSIBLY OFF THE COAST. EXPECT SFC DEWPOINT TEMPS TO DROP INTO THE LOW 60S WHICH WILL SEEM QUITE A BIT DRIER THAN THE MID 70S DEWPOINTS OF LATE. THIS ALSO MEANS SEASONABLE MIN TEMPS IN THE MID 60S FOR MON/TUE. EXPECT DRY CONDITIONS TO PERSIST AS UPPER LEVEL RIDGING BUILDS OVER S TX THROUGH MID WEEK. RIDGE DOES SHOW SIGNS OF BREAKING DOWN AGAIN FOR THE END OF THE WEEK WITH AN UPPER LOW OVER THE N PLAINS/MIDWEST/GREAT LAKES. THIS INTRODUCES NW FLOW ALOFT OVER TX FOR THE END OF THE WEEK WHICH MAY ALSO SUPPORT A WEAK FRONT MOVING INTO TX ALONG WITH A SERIES OF WEAK SHORTWAVES THAT COULD INITIATE A FEW ROUNDS OF CONVECTION ALONG THE RED RIVER AND N TX. POSSIBLE SOME OF THIS CONVECTION COULD WORK INTO SE TX. WILL KEEP 20 POPS FOR THE END OF THE WEEK WITH INCREASED MOISTURE AND FAVORABLE UPPER LEVEL PATTERN. AS WITH TROPICAL SEASON WILL KEEP AN EYE ON CONVECTION IN THE BAY OF CAMPECHE AND YUCATAN PENINSULA. BOTH GFS/ECMWF SUPPORT CONVECTION BECOMING ORGANIZED AGAIN FROM REMNANTS OF BARBARA BY TUESDAY. BOTH MODELS ALSO BRING THIS NEW SYSTEM INTO FLORIDA THUR/FRI TIME FRAME. THERE WILL BE A DECENT AMOUNT OF WIND SHEAR SO TOUGH TO KNOW HOW ORGANIZED THE SYSTEM WILL BECOME. NONETHELESS ALL INDICATIONS ARE THAT THIS WILL NOT BE A THREAT FOR THE TX COAST. 39 MARINE... LIGHT ONSHORE FLOW SHOULD BECOME LIGHT AND VARIABLE BY THIS AFTERNOON IN ADVANCE OF A WEAK COLD FRONT. LIGHT EAST TO SOUTHEAST WINDS AND 1 TO 2 FOOT SEAS WILL BE THE PREVAILING CONDITION THROUGH THE MAJORITY OF NEXT WEEK BECAUSE OF A VERY LIGHT PRESSURE GRADIENT BEHIND THE FRONT. 44 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 89 64 92 68 93 / 20 10 0 0 0 HOUSTON (IAH) 89 67 92 69 93 / 20 10 0 0 0 GALVESTON (GLS) 85 75 88 76 88 / 60 10 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
655 AM CDT SUN JUN 2 2013 .DISCUSSION... 12Z AVIATION DISCUSSION. && .AVIATION... A LINE OF STRONG TO SEVERE THUNDERSTORMS WILL MOVE THROUGH THE HOUSTON METRO AREA BETWEEN 12 AND 16Z THIS MORNING...AND OFF THE COAST BETWEEN 14 AND 18Z. WINDS MAY BRIEFLY GUST FROM THE NORTH AT 25 TO 25 KNOTS WITH VISIBILITIES DROPPING TO 1 MILE IN HEAVY RAIN. CONDITIONS SHOULD GRADUALLY IMPROVE BEHIND THE LINE WITH ALL TERMINALS VFR BY THIS AFTERNOON. SKIES SHOULD CLEAR OUT OVERNIGHT WITH LIGHT NORTHERLY WINDS. 44 && .PREV DISCUSSION... /ISSUED 445 AM CDT SUN JUN 2 2013/ DISCUSSION... A LINE OF THUNDERSTORMS IS BEGINNING TO FILL IN FROM SOUTH OF LUFKIN TO COLLEGE STATION. RAIN GAUGES IN TRINITY COUNTY ARE PICKING UP AS MUCH AS 2.2 INCHES IN 3 HRS AND AS MUCH AS 2 INCHES OF THAT HAS FALLEN IN THE LAST HOUR. ALSO SEEING A SIGNS OF A REAR INFLOW JET DEVELOPING IN THE BACK SIDE OF CONVECTION CLOSING IN ON BRYAN/COLLEGE STATION. BASED ON IR IMAGERY SEEMS CLOUD TOPS ARE COOLING MORE SO EXPECT DEEP CONVECTION TO CONTINUE THROUGH THE MORNING. THE MAIN THREAT WILL BE HEAVY RAINFALL ON THE ORDER OF 2 TO 3 INCHES AN HOUR LIKE ALREADY OBSERVED. STORM MOTIONS ARE EXPECTED TO BE SLOW AS IN 10 TO 2O MPH BUT COULD SEE CELLS CONTINUE TO DEVELOP ALONG A FRONT PUSHING INTO THE AREA WHICH COULD TRAIN ACROSS AREAS THAT HAVE ALREADY RECEIVED RAINFALL. SFC ANALYSIS AT 09Z SHOWS FRONTAL BOUNDARY SLOWLY PUSHING SOUTH FROM THE ARLATEX THROUGH C TX INTO THE NW HILL COUNTRY. LOOK FOR CURRENT CONVECTION TO SLOWLY WORK SOUTH AHEAD OF THE FRONT AND POSSIBLY OUT RUN IT BY A GOOD BIT. THE 00Z HIRES-WRF-ARW/TXTECH WRF AND HRRR ALL SHOW CURRENT LINE OF CONVECTION WORKING SOUTH THROUGH SE TX IN A BROKEN LINE. THE LINE THEN WEAKENS AS IT APPROACHES THE COAST BETWEEN 15Z-18Z. DECIDED TO KEEP SOME 50/60 POPS THROUGH 12-15Z AND THEN GRADUALLY DECREASE RAIN CHANCES. LOOKS LIKE THIS PART OF THE FORECAST MAY GO THROUGH ADDITIONAL MODIFICATIONS DEPENDING ON HOW THE CONVECTION EVOLVES THIS MORNING. DO THINK THIS CONVECTION SHOULD WORK OVER AND STABILIZE THE ATMOSPHERE FOR THE AFTERNOON SO 20 POPS FOR THE AFTERNOON LOOKS GOOD BUT IT COULD BE DRY. AS IT HAS BEEN DISCUSSED BEFORE...MAIN HAZARD THIS MORNING WILL BE HEAVY RAINFALL. UPPER LEVEL ANALYSIS SHOWS A TROUGH AXIS WORKING THROUGH THE AREA AND THERE MAY BE ENOUGH UPPER LEVEL SUPPORT TO KEEP CONVECTION GOING THIS MORNING. EXPECT UPPER LEVEL ASCENT TO WEAKEN DURING THE AFTERNOON AND CONVERGENCE ALONG THE FRONT TO WEAKEN AS WELL. THUS BEST CHANCES FOR HEAVY RAIN STILL THIS MORNING AND THREAT DIMINISHING IN THE AFTERNOON. PRECIP WATER VALUES THIS MORNING PEAK INVOF CONVECTION AROUND 1.8-2.0 INCHES AND DECREASE THIS AFTERNOON TO BELOW 1.5 INCHES. AS FOR THE REST OF THE FORECAST...MODELS STILL BRING WEAK FRONT TO THE COAST AND POSSIBLY OFF THE COAST. EXPECT SFC DEWPOINT TEMPS TO DROP INTO THE LOW 60S WHICH WILL SEEM QUITE A BIT DRIER THAN THE MID 70S DEWPOINTS OF LATE. THIS ALSO MEANS SEASONABLE MIN TEMPS IN THE MID 60S FOR MON/TUE. EXPECT DRY CONDITIONS TO PERSIST AS UPPER LEVEL RIDGING BUILDS OVER S TX THROUGH MID WEEK. RIDGE DOES SHOW SIGNS OF BREAKING DOWN AGAIN FOR THE END OF THE WEEK WITH AN UPPER LOW OVER THE N PLAINS/MIDWEST/GREAT LAKES. THIS INTRODUCES NW FLOW ALOFT OVER TX FOR THE END OF THE WEEK WHICH MAY ALSO SUPPORT A WEAK FRONT MOVING INTO TX ALONG WITH A SERIES OF WEAK SHORTWAVES THAT COULD INITIATE A FEW ROUNDS OF CONVECTION ALONG THE RED RIVER AND N TX. POSSIBLE SOME OF THIS CONVECTION COULD WORK INTO SE TX. WILL KEEP 20 POPS FOR THE END OF THE WEEK WITH INCREASED MOISTURE AND FAVORABLE UPPER LEVEL PATTERN. AS WITH TROPICAL SEASON WILL KEEP AN EYE ON CONVECTION IN THE BAY OF CAMPECHE AND YUCATAN PENINSULA. BOTH GFS/ECMWF SUPPORT CONVECTION BECOMING ORGANIZED AGAIN FROM REMNANTS OF BARBARA BY TUESDAY. BOTH MODELS ALSO BRING THIS NEW SYSTEM INTO FLORIDA THUR/FRI TIME FRAME. THERE WILL BE A DECENT AMOUNT OF WIND SHEAR SO TOUGH TO KNOW HOW ORGANIZED THE SYSTEM WILL BECOME. NONETHELESS ALL INDICATIONS ARE THAT THIS WILL NOT BE A THREAT FOR THE TX COAST. 39 MARINE... LIGHT ONSHORE FLOW SHOULD BECOME LIGHT AND VARIABLE BY THIS AFTERNOON IN ADVANCE OF A WEAK COLD FRONT. LIGHT EAST TO SOUTHEAST WINDS AND 1 TO 2 FOOT SEAS WILL BE THE PREVAILING CONDITION THROUGH THE MAJORITY OF NEXT WEEK BECAUSE OF A VERY LIGHT PRESSURE GRADIENT BEHIND THE FRONT. 44 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 89 64 92 68 93 / 30 10 0 0 0 HOUSTON (IAH) 91 67 92 69 93 / 70 10 0 0 0 GALVESTON (GLS) 87 75 88 76 88 / 60 10 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39 AVIATION/MARINE...44
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1016 AM CDT SUN JUN 2 2013 .UPDATE...LOW CLOUDS PERSIST ACROSS SOUTHERN WISCONSIN THIS MORNING DUE TO A COOLER AIRMASS THAT MOVED IN BEHIND DEPARTING LOW PRESSURE OVERNIGHT. THERE ARE SOME SIGNS THAT THE STRONG EARLY JUNE SUN IS STARTING TO CHIP AWAY AT THE CLOUD DECK...WITH A HOLE DEVELOPING JUST TO THE NORTH...AND SOME OF THE STRATUS TAKING A CELLULAR APPEARANCE TO THE NORTH AND WEST. THERE AREA SOME DIFFERENCES IN NAM...RAP...AND LOCAL WRF MODEL LOW LEVEL RH FOR THE REMAINDER OF THE DAY. THE NAM DRIES THINGS OUT THE QUICKEST...BY EARLY AFTERNOON...WITH THE RAP HOLDING ON TO HIGHER RH INTO EARLY EVENING. THERE IS A GOOD CHANCE THOUGH THAT ANY HOLES THAT DO FORM WILL LIKELY BE FILLED WITH CUMULUS DEVELOPMENT...SO NOT EXPECTING MUCH SUN TODAY. WITH 925 MB TEMPS ONLY RISING TO ABOUT 10C BY LATE AFTERNOON...UPPER 50S TO LOW 60S FOR HIGH TEMPS STILL SEEMS REASONABLE. && .AVIATION/18Z TAFS/...MVFR CLOUD DECK WILL LIKELY CONTINUE THROUGH LATE MORNING INTO EARLY AFTERNOON. THERE ARE SOME DIFFERENCES AMONG SHORT TERM MODELS AS TO WHEN CONDITIONS WILL IMPROVE...WITH THE RAP HOLDING ONTO SOME LOW CLOUDS INTO EARLY EVENING. GENERALLY SPLIT THE TIMING DIFFERENCE FOR NOW...EXPECTING VFR CONDITIONS TO RETURN BY MID AFTERNOON. LOOKS VERY QUIET TONIGHT AND TOMORROW AS HIGH PRESSURE SLIDES OVERHEAD. WINDS SHOULD BE LIGHT WITH SKIES TURNING MOSTLY CLEAR. && .PREV DISCUSSION... /ISSUED 312 AM CDT SUN JUN 2 2013/ TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH. COOLER BUT QUIET WEATHER IS IN STORE FOR SOUTHERN WISCONSIN TODAY. SURFACE LOW PRESSURE PUSHES OFF TO THE EAST THIS MORNING WITH HIGH PRESSURE DRIFTING IN FROM THE WEST. PRETTY GOOD COLD AIR ADVECTION ON NORTHERLY WINDS WILL BE ONGOING THROUGH THE MORNING. THIS...COUPLED WITH PERSISTENT CYCLONIC FLOW ALOFT...WILL RESULT IN PLENTY OF CLOUDS TODAY...GRADUALLY CLEARING FROM THE NORTHWEST LATE THIS AFTERNOON OR EVENING. HIGHS TODAY WILL BE 15 TO 20 DEGREES COOLER THAN YESTERDAY. THE HIGH PRESSURE RIDGE WILL BE OVERHEAD TONIGHT. LIGHT WINDS AND DRY AIR WILL ALLOW TEMPS TO COOL WELL INTO THE 40S...POSSIBLY SOME UPPER 30S IN FAVORED LOW SPOTS. THE LOW TEMP FORECAST COULD BE RUINED IF THOSE CLOUDS HANG ON TOO LONG...THIS WOULD KEEP THEM UP QUITE A BIT. MONDAY THROUGH TUESDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH. SHORT TERM MODELS SHOW HIGH PRESSURE OVER THE REGION MONDAY SLIDING EASTWARD MONDAY NIGHT. DRY AIRMASS OVER THE REGION WILL BRING QUIET WEATHER. TEMPERATURES WILL CONTINUE TO BE COOL DURING THIS TIME. 500MB LOW OVER NORTH DAKOTA ON TUESDAY WILL SLOWLY SHIFT INTO WEST CENTRAL MINNESOTA BY LATE TUESDAY NIGHT. ASSOCIATED SURFACE LOW PRESSURE WILL WEAKEN AS IT SHIFTS SOUTHEAST INTO SOUTHERN MINNESOTA FROM THE DAKOTAS. AREA OF MODEST 850MB WARM AIR ADVECTION...AND 850MB TO 700MB LAYER Q VECTOR CONVERGENCE...ARE EXPECTED TO SHIFT ACROSS THE AREA TUESDAY INTO TUESDAY NIGHT. AREA FORECAST SOUNDINGS FROM NAM/GFS SHOW A GENERAL TOP DOWN MOISTENING OF THE AIR COLUMN ACROSS THE AREA...MORE SO ON THE GFS THAN THE NAM. CONTINUED INCREASING POP TREND FROM WEST TO EAST TUESDAY AND TUESDAY NIGHT FOR NOW. MAY NEED TO INCREASE POPS IN LATER FORECASTS FOR TUESDAY NIGHT...IF BETTER COLUMN MOISTURE IS FOUND. THUNDER MENTION WAS REMOVED TUESDAY NIGHT...AS LITTLE TO NO INSTABILITY REMAINED IN AREA FORECAST SOUNDINGS. TEMPERATURES WILL REMAIN COOL DURING THIS TIME...WITH ONSHORE WINDS. WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE IS MEDIUM. GFS/ECMWF CONTINUE TO SHOW FAIRLY SIMILAR TRENDS FOR MOST OF THIS PERIOD ACROSS THE REGION. THEY BRING THE 500MB LOW EAST ACROSS THE REGION WEDNESDAY NIGHT INTO EARLY THURSDAY. GFS KEEPS SHORTWAVE TROUGH OVER THE REGION INTO THURSDAY NIGHT...BEFORE SLIDING EAST ON FRIDAY. THE ECMWF IS QUICKER WITH THE SHORTWAVE TROUGH EXITING THE AREA THURSDAY. DECENT COLUMN MOISTURE REMAINS OVER THE AREA PER GFS FORECAST SOUNDINGS WEDNESDAY...THEN BECOME DRY IN THE MID LEVELS WEDNESDAY NIGHT INTO THURSDAY. THE LOW LEVELS REMAIN SATURATED DURING THIS TIME. WILL CONTINUE USING CONSENSUS POPS WEDNESDAY INTO THURSDAY NIGHT ACROSS THE AREA. AGAIN...MAY NEED HIGHER POPS DURING THIS TIME IF MOISTURE IN AIR COLUMN BECOMES DEEPER. KEPT SLIGHT CHANCES FOR THUNDER WEDNESDAY INTO WEDNESDAY NIGHT...BUT COULD BE REMOVED IN LATER FORECASTS IF ELEVATED CAPE CONTINUES TO BE VERY WEAK. ONSHORE WINDS WILL CONTINUE TO KEEP THE AREA COOL. GFS KEEPS HIGH PRESSURE IN THE AREA FRIDAY INTO SATURDAY...WITH THE ECMWF SHIFTING THE HIGH TO THE EAST...AND A 500MB SHORTWAVE TROUGH SLIDES EAST ACROSS NORTHERN WISCONSIN. GIVEN THE DIFFERENCES THIS FAR OUT...WILL USE CONSENSUS POPS AND TEMPERATURES FOR THIS PERIOD. AVIATION/12Z TAFS/... MVFR CIGS ACROSS THE AREA THIS MORNING WILL GRADUALLY LIFT TO VFR CIGS THIS AFTERNOON. THEN CLEARING IS EXPECTED TO ARRIVE BY EARLY TO MID EVENING...FIRST AT KMSN...FOLLOWED BY KMKE/KUES/KENW. NORTH TO NORTHWEST WINDS WILL SHIFT TO NORTHEAST AT KMKE/KENW EARLY THIS AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DDV TODAY/TONIGHT AND AVIATION/MARINE...DAVIS MONDAY THROUGH SATURDAY...WOOD
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 AM MST SUN JUN 2 2013 .SYNOPSIS...HIGH PRESSURE ANCHORED OVER NORTHERN MEXICO WILL BRING DRY AND HOT CONDITIONS THIS WEEK. && .DISCUSSION...DRY SOUTHWESTERLY FLOW WITH HIGH PRESSURE FROM NORTHERN MEXICO DOMINATING OUR WEATHER. MOISTURE INCREASE THROUGH NEW MEXICO WILL GENERALLY STAY EAST OF OUR AREA WITH ONLY A BIT OF LOW LEVEL MOISTURE SPILLING OVER THE STATE LINE. PERHAPS ENOUGH FOR ISOLATED CONVECTION IN THE FAR EASTERN MOUNTAINS. WITH A HEAD START ON YESTERDAY DUE TO HIGHER OVERNIGHT LOWS AND THE POTENTIAL SUGGESTED BY THE 12Z KTWC SOUNDING WE TWEAKED FORECAST TEMPERATURES UP A TAD. BASED ON LATEST TRENDS AND HRRR WE ALSO TRENDED CLOUD COVER AND FAR EASTERN MOUNTAIN CONVECTION DOWN A LITTLE THIS AFTERNOON AND EARLY EVENING. && .PREV DISCUSSION...HIGH PRESSURE ALOFT WAS CENTERED OVER SRN CHIHUAHUA WITH A SHORTWAVE TROUGH JUST OFF THE SRN CALIFORNIA COAST EARLY THIS MORNING. MEANWHILE...LOWER-LEVEL ELY FLOW WAS ADVECTING MOISTURE WWD ACROSS SRN NEW MEXICO. BASED ON VARIOUS 02/00Z NWP MODELS...HAVE MAINTAINED ISOLD SHOWERS AND THUNDERSTORMS NEAR THE NEW MEXICO BORDER THIS AFTERNOON AND EARLY THIS EVENING. ANY SHOWERS/TSTMS WILL END BY MIDNIGHT TONIGHT. DRY SWLY FLOW ALOFT WILL THEN PREVAIL MON-TUE IN RESPONSE TO A WEAK LOW PRESSURE SYSTEM OFF THE SRN CALIFORNIA COAST AND HIGH PRESSURE ALOFT CENTERED OVER CHIHUAHUA. VERY DRY REGIME TO CONTINUE WED-THUR AS WEAK WLY FLOW ALOFT WED TRANSITIONS TO NWLY FLOW ON THUR. FOR FRI-SAT...02/00Z GFS/ECWMF WERE VERY SIMILAR WITH DEVELOPING A REX BLOCK JUST OFF THE WEST COAST...WITH HIGH PRESSURE ALOFT CENTERED NEAR THE NRN CALIFORNIA COAST AND LOW PRESSURE CENTERED OFF THE NRN BAJA CALIFORNIA COAST. THE ECMWF WAS MORE-ROBUST VERSUS THE GFS WITH MOVING MOISTURE MAINLY ABOVE 600 MB SEWD ACROSS SE AZ. A BLEND OF THE GFS/ECMWF YIELDED MOSTLY CLEAR SKIES FRI-SAT. HIGH TEMPS THIS AFTERNOON WILL BE ABOUT 1-2 DEGS F HOTTER VERSUS SAT AFTERNOON. A FEW LOCALES MAY APPROACH OR EVEN EXCEED RECORD TEMPS THIS AFTERNOON...INCLUDING KTUS. A FEW DEGREES OF MINOR COOLING WILL OCCUR MON FOLLOWED BY NO SIGNIFICANT CHANGE IN DAYTIME TEMPS TUE-SAT. && .AVIATION...SCT CLOUDS AT 8-12K FT AGL MAINLY EAST OF KTUS WITH ISOLD -TSRA NEAR THE NEW MEXICO BORDER THIS AFTERNOON AND THIS EVENING. OTHERWISE...SKC-SCT CLOUDS ABOVE 20K FT AGL THRU MONDAY MORNING OR 03/12Z. SURFACE WIND THIS AFTERNOON AND THIS EVENING WLY/SWLY 10-18 KTS WITH GUSTS TO NEAR 25 KTS. OTHERWISE...SURFACE WIND LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...EXPECT ISOLATED MAINLY DRY THUNDERSTORMS THIS AFTERNOON AND EARLY THIS EVENING NEAR THE NEW MEXICO BORDER. OTHERWISE...DRY CONDITIONS WITH HOT DAYTIME TEMPERATURES WILL PREVAIL THIS WEEK. DAYTIME MINIMUM RELATIVE HUMIDITIES WILL GENERALLY BE IN THE SINGLE DIGITS TO LOWER TEENS WITH FAIR TO POOR OVERNIGHT RECOVERIES. NORMAL DIURNAL WIND TRENDS WILL OCCUR...WITH GUSTINESS DURING THE AFTERNOON HOURS DUE TO STRONG DAYTIME HEATING. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON MEYER/RASMUSSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
324 PM MDT SUN JUN 2 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 318 PM MDT SUN JUN 2 2013 MAIN CONCERN IS THE POTENTIAL FOR RED FLAG CONDITIONS ON MONDAY. FINALLY STARTING TO SEE A FEW ECHOES ON RADAR NEAR THE SRN BORDER OF RIO GRANDE COUNTY. OTHERWISE...ONLY SEEING A FEW CU DEVELOPING ALONG THE ERN MTS. THE LATEST NAM RUN CONTINUES TO SHOW SOME PCPN OVR THE MTS THIS AFTERNOON AND EVENING...AND EVEN KEEPS SOME LINGERING PCPN OVR THE SWRN CO MTS LATE TONIGHT. THE HRRR KEEPS THE FORECAST AREA DRY UNTIL AROUND 01Z AND THEN SHOWS A LITTLE QPF OVR THE SERN CORNER OF THE STATE...WHICH THE GFS ALSO SHOWS. WILL KEEP ISOLD POPS FOCUSED OVR AND NR THE SRN MTS THIS EVENING AND ENDING LATE. ON MONDAY WESTERLY FLOW ALOFT IS EXPECTED WITH AN UPR LOW MOVING ACRS MT DURING THE DAY AND AN UPR RIDGE OVR MEXICO. THE SFC WINDS ARE EXPECTED TO PICK UP FOR THE AFTERNOON HOURS ACRS MUCH OF THE FORECAST AREA FROM THE WEST OR SW AND IT LOOKS LIKE MANY AREAS COULD SEE THE GUSTS REACH RED FLAG CRITERIA. AT THE SAME TIME...HIGH TEMPS TOMORROW ARE EXPECTED TO BE MUCH ABOVE AVERAGE AND WITH THE WESTERLY FLOW THE DEW POINTS WILL DRY OUT AND RH VALUES WL DROP BELOW 15 PERCENT AT THE LOWER ELEVATIONS. THUS WENT AHEAD AND ISSUED A RED FLAG WARNING FOR ZONES 222...225...227...233 AND 237 WHERE THE FUELS ARE DRY AND THE WIND AND RH CRITERIA SHOULD BE MET. ZONE 221 LOOKED MARGINAL SO LEFT THEM OUT OF THE WARNING FOR NOW...BUT THIS WILL HAVE TO BE RE-EVALUATED WITH LATER FORECAST MODEL RUNS. IN ZONE 225 IT LOOKED LIKE THE RH AND WIND CRITERIA WOULD BE MET MAINLY BELOW 9000 FEET. ONE OTHER CONCERN FOR MONDAY IT WHERE THE DRY LINE WILL SET UP. THE LATEST RUN OF THE NAM12 PUSHES THE DRY LINE WELL INTO KS MON AFTERNOON AND SPC HAS THE SLIGHT RISK AREA JUST TO THE EAST OF THE CO BORDER. THE NAM HAS SPOTTY PCPN ACRS THE FORECAST AREA MON AFTERNOON AND ONCE AGAIN THE GFS SHOWS ALMOST NOTHING UNTIL EVENING...WHEN IT TOO HAS SPOTTY QPF. ONCE AGAIN...WITH THE LOW LEVELS BEING DRY...MEASURABLE PCPN WOULD BE SPOTTY AT BEST AND THE MAIN THUNDERSTORMS THREATS WOULD BE WIND AND LIGHTNING. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 318 PM MDT SUN JUN 2 2013 ...CHANCE OF SOME STRONG STORMS TUESDAY AND WEDNESDAY... MAIN FOCUS IN THE EXTENDED WILL BE THE THREAT OF SVR WX RETURNING TO THE AREA TUE AND WED. ON TUE...AN UPPER LOW WILL BE OVR THE DAKOTAS...AND A COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL BE PUSHING THROUGH IN THE MORNING. WINDS WILL VEER TO AN UPSLOPE DIRECTION BEHIND THE FRONT...AND SET THE STAGE FOR SCT TS DEVELOPMENT TUE AFTERNOON INTO TUE EVE. STORMS WILL DEVELOP OVR THE ERN MTS AND THEN SHIFT EWD BY LATE AFTERNOON. THERE WILL BE MORE THAN ENOUGH SHEAR FOR STORM ORGANIZATION...IN THE 40 KT RANGE INCREASING TO 50 KTS OR MORE BY EVE. MAIN LIMITING FACTOR WILL BE SOME DRY AIR IN THE LOW LEVELS...WHICH WILL KEEP CAPE MAINLY IN THE 750-1200 J/KG RANGE. HOWEVER...GOOD FORCING ALONG WITH PERSISTENT UPSLOPE WILL HELP BUILD A FEW STRONG STORMS...SOME OF WHICH COULD BECOME MARGINALLY SVR AS THEY MOVE E OF I-25 AND INTO BETTER MOISTURE LATE IN THE DAY. BEST CHANCE FOR SVR WX WILL BE OVER THE SE PLAINS INCLUDING BACA AND PROWERS COUNTIES...WHICH IS WHERE SPC CURRENTLY HAS THEIR SLIGHT RISK OUTLOOK FOR DAY 3. TEMPS TUESDAY WILL BE MUCH LOWER THAN ON MONDAY...BUT STILL FAIRLY WARM FOR THE PLAINS...IN THE MID 80S. WEDNESDAY COULD BE A MORE ACTIVE DAY WITH SVR WX POTENTIAL...BUT IT WILL ALSO BE A BIT TRICKY WITH THE PREVIOUS DAY`S CONVECTION POSSIBLY HAVING AND EFFECT ON MORNING CONDITIONS...AND THE POSSIBILITY THAT THE ATMOSPHERE MIGHT BECOME TOO STABLE TO SUPPORT STRONG CONVECTION. EARLIER RUNS OF THE NAM HAD HINTED AT THAT POSSIBILITY...WHILE THE LATEST NAM SEEMS TO BE ALIGNING BETTER WITH THE GFS IN SHOWING THE POTENTIAL FOR ANOTHER ROUND OF STRONG STORMS LATE IN THE AFTERNOON. WILL FOLLOW THIS TREND AND MAINTAIN A THREAT OF STORMS DEVELOPING IN THE AFTERNOON WITH UPSLOPE OVR THE ERN MTS...THEN SPREADING TO THE PLAINS LATE IN THE DAY. CAPE COULD BE A BIT HIGHER WED...SO IF THERE IS A BIT OF SUN EARLY IN THE AFTERNOON THIS COULD BRING THE THREAT OF SVR A LITTLE FARTHER TO THE WEST WED AFTERNOON. WILL HAVE TO WATCH FOR THIS POTENTIAL NEXT COUPLE OF DAYS. THE ACTIVE PATTERN LOOKS TO CONTINUE THROUGH THE END OF THE WEEK AND POSSIBLY INTO THE WEEKEND...AS A SERIES OF WEAK SHORTWAVES ROUND THE BACKSIDE OF THE TROUGH THAT WILL BE MOVING THROUGH THE GREAT LAKES REGION THU-FRI. DECREASED SHEAR MAY LIMIT THE SVR THREAT...BUT WITH SOME MOISTURE IN PLACE THE FOCUS MAY SHIFT TO THE POTENTIAL FOR SOME LOCALLY HEAVY RAIN. NCEP MODELS INDICATE BETWEEN .25 AND .50 INCHES OF LIQUID FOR THE WALDO SCAR TUE...ANOTHER .5 TO 1.0 INCHES WED...AND STILL MORE PRECIP FOR THE AREA LATE THU INTO FRI. SO...THE WALDO BURN SCAR WILL CONTINUE TO BE A TROUBLE SPOT AND WILL NEED SOME EXTRA ATTENTION THROUGH THE END OF THE WEEK. ROSE && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 318 PM MDT SUN JUN 2 2013 VFR CONDITIONS ARE EXPECTED AT KCOS...KPUB AND KALS FOR THE NEXT 24 HOURS. WEST TO SW WINDS ARE EXPECTED TO BE BREEZY MONDAY AFTERNOON WITH GUSTS OF 25-30 KTS AT THE TAF SITES. && .PUB WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM NOON TO 8 PM MDT MONDAY FOR COZ222-225-227- 233-237. && $$ SHORT TERM...28 LONG TERM...ROSE AVIATION...28
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
405 PM EDT SUN JUN 2 2013 ...ISOLATED SEVERE STORMS POSSIBLE THIS EVENING... .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... COLD FRONT STILL NORTHWEST OF THE STATE HOWEVER TWO LINES OF CONVECTION HAVE DEVELOPED ACROSS THE CWA AHEAD OF THIS FRONT. LOCAL WRF HAS PICKED UP ON BOTH LINES BUT WEAKENS THE EASTERN LINE AND LETS THE WESTERN LINE DOMINATE. ALTHOUGH HRRR ISNT AS CLEAR WITH BOTH LINES...IT DOES SHOW THE WEST LINE OF CONVECTION CONTINUING TO DOMINATE AND PUSH EAST. FORECAST IS IN LINE WITH THESE TWO HI-RES MODELS WITH THE FOCUS BECOMING ON THE WEST LINE. WILL CONTINUE TO MOVE EAST TONIGHT SO HAVE SHOWN CATEGORICAL POPS INTO THE EVENING FOR MUCH OF THE CWA. WITH 1500-2000 J/KG OF MUCAPE THIS AFTERNOON ISOLATED SVR STORMS ARE POSSIBLE WITH THE MAIN THREATS BEING WIND AND HAIL. BEHIND THIS LINE...COULD STILL SEE SCATTERED STORMS DEVELOP OVERNIGHT. CONFIDENCE IS LOW THOUGH ON FORECAST TONIGHT AS THERE ARE SOME DIFFERENCES IN THE MODELS /INCLUDING HI RES/...SOME SHOWING AN ACTIVE NIGHT WHILE OTHERS LIMITING ACTIVITY. HAVE BASICALLY GONE CHANCE POPS THROUGH THE NIGHT. COLD FRONT WILL PUSH THROUGH NORTH GEORGIA TONIGHT AND INTO CENTRAL GEORGIA ON MONDAY. WILL BE ENOUGH MOISTURE AND LIFT FROM THE FRONT THAT CONVECTION IS POSSIBLE AGAIN ON MONDAY BUT THE BETTER CHANCES WILL BE ACROSS THE SOUTHEAST PART OF THE CWA. PLENTY OF INSTABILITY /2000 J/KG OF MUCAPE/ MONDAY AFTERNOON TO SEE A FEW STRONG STORMS. STORMS LOOK TO CONTINUE WITH LAST IN A SERIES OF SHORTWAVES TO MOVE THROUGH MONDAY NIGHT. WILL INCREASE POPS TO HIGH END CHANCE RANGE THROUGH 12Z TUESDAY AS FRONT PUSHES THROUGH. TEMPS ARE NEAR A MODEL BLEND. 11 && .PREV DISCUSSION... /ISSUED 207 PM EDT SUN JUN 2 2013/ PREV DISCUSSION... UPDATE... /ISSUED 1025 AM EDT SUN JUN 2 2013/ SHOWERS AND THUNDERSTORMS HAVE BEEN SLOW TO DEVELOP ACROSS MUCH OF THE CWA THIS MORNING SO MAIN CHANGE TO THE FORECAST HAS BEEN TO REDUCE POPS FOR THE MORNING. BY EARLY AFTERNOON THOUGH...THE HRRR INCREASES COVERAGE GREATLY ACROSS THE NORTH AND WESTERN PART OF THE CWA AND THIS IS IN LINE WITH THE FORECAST. SOME INDICATION IN THE MODELS SUCH AS THE GFS AND ECMWF THAT THE BETTER COVERAGE WILL CONTINUE INTO TONIGHT AND MAY NEED TO ADJUST OUR POPS UPWARD OVERNIGHT IN FUTURE UPDATES. PORTIONS OF FANNIN AND GILMER COUNTY HAVE ALREADY SEEN AROUND 4 INCHES OF RAIN DURING THIS EVENT SO FAR. ALTHOUGH THEY HAVE RECEIVED A REPRIEVE FROM THE HEAVY RAIN...WILL HAVE TO CONTINUE TO MONITOR THIS AREA CLOSELY FOR POTENTIAL ISOLATED FLOODING AS HEAVY RAIN IS POSSIBLE AGAIN THIS AFTERNOON. 11 PREVIOUS LONG TERM... TUESDAY THROUGH SATURDAY/... /ISSUED 353 AM EDT SUN JUN 2 2013/ MODELS SHOW THE COLD FRONT PUSHING INTO SOUTH GA MONDAY NIGHT... WHERE IT MEANDERS... THEN DRIFTS BACK NORTH SLIGHTLY BY TUESDAY AFTERNOON. THIS WILL WARRANT HOLDING ONTO A SLIGHT CHANCE OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE SOUTHERN REACHES OF THE FORECAST AREA ON TUESDAY. A SLIGHT CHANCE OF STORMS SPREAD BACK ACROSS NORTH GA BY WEDNESDAY AS AN EASTERLY WIND FLOW BEGINS TO ADVECT DEEP ATLANTIC MOISTURE BACK OVER THE AREA WHILE A SERIES OF UPPER DISTURBANCES BEGIN TO CARVE A BROAD LONG WAVE TROUGH THAT STRETCHES DOWN THE MS VALLEY REGION BY WEDNESDAY AFTERNOON. THIS UPPER TROUGH DEEPENS OVER THE SOUTH ON THURSDAY AND PROVIDES THE SUPPORT FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE FORECAST AREA THURSDAY AFTERNOON AND EVENING. AT THE SAME TIME... THE ECMWF AND GFS SHOW AN EARLY SEASON TROPICAL SYSTEM PUSHING INTO THE EASTERN GULF ON THURSDAY... ACROSS CENTRAL FL AND INTO THE WESTERN ATLANTIC ON FRIDAY...THEN UP THE EAST COAST ON SATURDAY AS HIGH PRESSURE BUILDING SOUTH OF CANADA HELPS HOLD THE SYSTEM OFF SHORE. AHEAD OF THIS SYSTEM ON FRIDAY... A CONTINUED MOIST EASTERLY FLOW AND UPPER TROUGH WILL SUPPORT DIURNALLY DRIVEN AFTERNOON AND EVENING CONVECTION ACROSS THE AREA AGAIN ON FRIDAY. AS THE TROPICAL SYSTEM PUSHES OFF TO THE NE ON SATURDAY... MODELS SHOW A COLD FRONT AND DRIER AIR SPREADING SOUTH IN ITS WAKE. DUE TO MUCH UNCERTAINTY ON TIMING AND TRACK... WILL CONTINUE TO SHOW A CHANCE OF CONVECTION ON SATURDAY FOR NOW AND MONITOR CHANGES IN THE MODEL RUNS CLOSELY OVER THE NEXT SEVERAL DAYS. 39 AVIATION... 18Z UPDATE... CONVECTION HAS BEGUN TO DEVELOP AROUND THE TERMINALS AND FOR NOW IS ORIENTED IN TWO LINES. EXPECT CONVECTION TO CONTINUE THROUGH THIS EVENING BUT THEN CHANCES WILL DECREASE. HAVE KEPT SHRA IN THE TAFS FOR MUCH OF THE NIGHT...BUT CANT COMPLETELY RULE OUT THE CHANCE OF MORE TSRA. COULD SEE SOME GUSTY WINDS AND BRIEF LOWER CIGS IN THE TSRA BUT SO SHORT LIVED THAT HAVENT INCLUDED IT IN THE TAF YET EXCEPT FOR MINOR REDUCTION IN VSBY. CIGS ARE EXPECTED TO LOWER OVERNIGHT INTO THE IFR TO LOW MVFR RANGE. //ATL CONFIDENCE...18Z UPDATE... MEDIUM CONFIDENCE ON TIMING OF CONVECTION...VSBYS AND CIGS. HIGH CONFIDENCE ON WIND DIRECTION...BUT MEDIUM ON SPEEDS DUE TO POSSIBLE GUSTS IN TSRA. 11 && .PRELIMINARY POINT TEMPS/POPS... ATHENS 67 84 63 87 / 80 40 30 10 ATLANTA 69 84 68 86 / 80 40 10 10 BLAIRSVILLE 62 80 60 81 / 80 40 10 10 CARTERSVILLE 66 84 62 88 / 80 40 10 10 COLUMBUS 72 87 70 89 / 80 50 30 10 GAINESVILLE 67 83 65 85 / 80 40 20 10 MACON 69 86 68 90 / 80 50 40 20 ROME 67 83 61 88 / 70 30 10 10 PEACHTREE CITY 67 84 62 87 / 80 40 20 10 VIDALIA 72 86 71 89 / 60 60 40 30 && .FFC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...11 LONG TERM....DEESE AVIATION...11
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1254 PM CDT SUN JUN 2 2013 .DISCUSSION... ISSUED 1037 AM CDT SUN JUN 2 2013 MORNING SURFACE ANALYSIS SHOWS A WEAK TROUGH AXIS EXTENDING FROM THE GREAT LAKES S/SW INTO CENTRAL ILLINOIS. 13Z HRRR SUGGESTS ISOLATED SHOWERS WILL DEVELOP ALONG/AHEAD OF THIS FEATURE ACROSS THE EASTERN HALF OF THE KILX CWA LATER THIS MORNING THROUGH THE AFTERNOON. HAVE SEEN SOME WEAK RADAR ECHOES DEVELOPING WITHIN THE PAST COUPLE OF HOURS...SO THIS SEEMS TO BE A PLAUSIBLE SOLUTION. WILL THEREFORE MAINTAIN THE SLIGHT CHANCE POPS ALONG AND EAST OF A BLOOMINGTON TO EFFINGHAM LINE. SKIES WILL REMAIN CLOUDY TODAY...AS EVIDENCED BY CURRENT VISIBLE SATELLITE IMAGERY AND STRONGLY NEGATIVE CU-RULE. DUE TO THE CLOUDS AND A COOL NORTHWESTERLY WIND...HIGH TEMPS WILL REMAIN WELL BELOW NORMAL FOR THIS TIME OF YEAR. HAVE TWEAKED AFTERNOON HIGHS DOWN A FEW DEGREES...WITH READINGS MAINLY IN THE MIDDLE TO UPPER 60S. A FEW LOWER 70S WILL BE POSSIBLE SOUTH OF I-70. ZONE UPDATE HAS ALREADY BEEN ISSUED. && .AVIATION... ISSUED 1254 PM CDT SUN JUN 2 2013 LOW CONFIDENCE AVIATION FORECAST TODAY...DUE TO QUESTIONS SURROUNDING TIMING OF POTENTIAL CLEARING TONIGHT. CURRENT SATELLITE AND AREA OBSERVATIONS SHOW A WIDESPREAD BLANKET OF MVFR CEILINGS ACROSS THE REGION...WITH CLOSEST APPRECIABLE CLEARING LOCATED WELL TO THE NORTHWEST OVER NORTHERN IOWA. LOW-LEVEL FLOW CONTINUES TO SLOWLY ADVECT THE CLOUD SHIELD SOUTHEASTWARD...HOWEVER WINDS ARE EXPECTED TO BECOME LIGHT/VARIABLE OVERNIGHT...SLOWING THE EXIT OF THE CLOUDS. BOTH NAM AND GFS FORECAST SOUNDINGS HANG ON TO A SATURATED LAYER BETWEEN 2500 AND 3500FT THROUGH MONDAY MORNING...SUGGESTING CLOUDS MAY HOLD FIRM THROUGH THE NIGHT. MEANWHILE...HRRR CEILING FORECAST SHOWS CLOUDS DISSIPATING AT THE TAF SITES...BUT REMAINING IN PLACE FURTHER SOUTH ACROSS THE S/SE KILX CWA AS WINDS BECOME LIGHT AND/OR VEER TO E/NE. GIVEN HRRR FORECAST AND THE APPEARANCE THAT MUCH OF THE UPSTREAM CLOUD COVER ACROSS IOWA IS DIURNAL/CELLULAR...HAVE SCATTERED CEILINGS AT THE CENTRAL ILLINOIS TERMINALS BETWEEN 03Z AND 06Z. IF PARTIAL CLEARING DOES INDEED OCCUR TONIGHT...IT WILL SHORT-LIVED...AS HIGHLY NEGATIVE CU-RULE SUGGESTS BKN CEILINGS DEVELOPING AGAIN BY LATE MONDAY MORNING THROUGH THE AFTERNOON. BARNES && .PREV DISCUSSION... ISSUED 225 AM CDT SUN JUN 2 2013 COLD FRONT HAS PUSHED WELL TO THE EAST EARLY THIS MORNING. 2 AM SURFACE MAP SHOWS A SECONDARY TROUGH SWINGING ACROSS THE NORTHWEST PART OF ILLINOIS...AROUND LOW PRESSURE IN NORTHEAST LOWER MICHIGAN. EXTENSIVE STRATOCUMULUS IS FOUND ALONG AND BEHIND THIS TROUGH...WHILE SKIES HAVE BEEN CLEAR OVER THE EASTERN CWA THE PAST FEW HOURS BETWEEN THE TROUGH AND FRONT. THE MAIN FORECAST ISSUE FOR THIS PACKAGE INVOLVES MID WEEK RAIN CHANCES. SHORT TERM...TODAY THROUGH TUESDAY... HAVE MAINTAINED SOME 20 PERCENT RAIN CHANCES ACROSS THE EASTERN CWA TODAY AS THE TROUGH SWINGS THROUGH...BUT QUIET WEATHER WILL GENERALLY PREVAIL THROUGH TUESDAY. 850 MB TEMPS FALLING INTO THE LOW SINGLE DIGITS CELSIUS TONIGHT SHOULD ALLOW FOR SURFACE LOWS IN THE UPPER 40S OVER ABOUT THE NORTHEAST HALF OF THE CWA...WITH HIGHS IN THE UPPER 60S TO AROUND 70. AS SURFACE HIGH PRESSURE SHIFTS EASTWARD ACROSS THE GREAT LAKES MONDAY NIGHT...DECENT WARM AIR ADVECTION WILL OVERSPREAD THE CWA AND BRING HIGHS WELL INTO THE 70S. LONG TERM...TUESDAY NIGHT THROUGH SATURDAY... EVENING MODEL GUIDANCE IN REASONABLE AGREEMENT WITH ZIPPING AN UPPER TROUGH THROUGH THE NORTHERN AND CENTRAL PLAINS ON TUESDAY...ASSOCIATED WITH A CLOSED SURFACE LOW CLOSER TO THE CANADIAN BORDER. NOT TOO MUCH CHANGE NOTED WITH TRENDS OF SPREADING RAIN CHANCES INTO AREAS WEST OF I-55 BY LATE TUESDAY NIGHT. RATHER PERSISTENT EASTERLY FLOW ACROSS THE GREAT LAKES DOES NOT BODE VERY WELL FOR DECENT PRECIP CHANCES IN THE EAST...AND WILL GO WITH SLIGHT CHANCES THERE ON WEDNESDAY. MAIN TROUGH AXIS SHOULD CROSS THE AREA LATE WEDNESDAY NIGHT THROUGH THURSDAY... WHEN HIGHEST POPS OF 40 TO 50 PERCENT WILL BE IN THE FORECAST. LATE IN THE WEEK...HAVE MAINTAINED SOME SLIGHT CHANCES FOR FRIDAY. HOWEVER...GENERAL TREND SHOULD BE FOR DRY WEATHER INTO THE FIRST HALF OF THE WEEKEND...WITH HIGH PRESSURE RIDGING SOUTHWEST FROM THE GREAT LAKES. GEELHART && .ILX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR ILZ051. && $$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1158 AM CDT SUN JUN 2 2013 .AVIATION... MUCH OF THE ORGANIZED CONVECTION HAS MOVED OFF THE LOUISIANA COAST LATE THIS MORNING WITH SOME LINGERING ANVIL RAINS AND ELEVATED CONVECTION INLAND BETWEEN THE COAST AND KMSY/KNEW. THIS ACTIVITY WAS DRIVEN BY MESO-HIGH FORCING WITH THE ACTUAL COLD FRONT STILL ORIENTED NE-SW FROM PADUCAH KY TO ABOUT JACKSON MS TO BEAUMONT TX. ISOLATED SHRA/TSRA CAN NOT BE RULED OUT ALONG THE FRONT LATER THIS AFTERNOON BUT COVERAGE SHOULD REMAIN LIGHT. VFR CLOUD DECKS SHOULD ALSO THIN TO VFR CAVOK LATE AFTERNOON. 24/RR && .DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SLURRY SUPPORT. MONITORING RIVER FLOODING. MONITORING CONVECTIVE TRENDS. && .PREV DISCUSSION... /ISSUED 1017 AM CDT SUN JUN 2 2013/ UPDATE... LOOKING AT OVERALL RADAR TRENDS...HAVE ADJUSTED POPS FOR TODAY TO REFLECT THE ONGOING CONVECTION OVER COASTAL LOUISIANA AND THE WEAK MESOHIGH IN THE WAKE OF THE EARLY MORNING CONVECTION OVER THE REMAINDER OF THE CWA. HAVE ALSO ADJUSTED CLOUD COVER TO REFLECT OVERALL HIGHER AMOUNT OF SKY COVER THAN INITALLY ANTICIPATED. THE RAIN COOLED STABLE AIRMASS COMBINED WITH THE CLOUD COVER HAS ALSO ALLOWED FOR SLOWLY TEMPERATURE RECOVERY AND ADJUSTED DAYTIME HIGHS DOWNWARD A FEW DEGREES. EXPECT TO SEE SOME RECOVERY THIS AFTERNOON OF WARMTH AND MOISTURE WHICH WILL ALLOW FOR SOME REGENERATION IN AREAS NOT COMPLETELY WORKED OVER THIS MORNING. GIVEN THIS...KEEP LIKELY POPS IN PLACE FOR COASTAL LOUISIANA AND MISSISSIPPI...AND ONLY HAVE CHANCE POPS ELSEWHERE. STILL EXPECT ACTUAL FRONTAL PASSAGE TONIGHT...WITH A DRIER WEATHER REGIME TAKING HOLD FOR MUCH OF THE WEEK. 32 PREV DISCUSSION... /ISSUED 415 AM CDT SUN JUN 2 2013/ SHORT TERM... MOST ACTIVE PORTION OF THE FORECAST WILL BE OVER THE NEXT 12 TO 15 HOURS. SURFACE ANALYSIS SHOWS COLD FRONT DRAPED ACROSS SOUTH-CENTRAL TEXAS...NORTHERN LA THROUGH EASTERN ARKANSAS AND POINTS FURTHER NORTH. A LARGE CLUSTER OF SHOWERS AND EMBEDDED STRONGER THUNDERSTORMS AHEAD OF THE FRONT HAS BEEN SURGING SOUTHWARD OVERNIGHT. AT THIS POINT...THIS ACTIVITY HAS BECOME OUTFLOW DRIVEN VS THE MEAN FLOW WHICH WOULD BE MORE EASTERLY. HRRR SEEMS TO BE THE ONLY MESO MODEL THAT HAS BEEN HAVING A GOOD INITIATION. IT SUGGESTS A WEAKENING TREND WILL CONTINUE AS THE LEADING EDGE MOVES SOUTH ACROSS MS AND LA TOWARDS THE CWA. WHILE IN GENERAL THIS WILL LIKELY BE THE CASE...THERE/S STILL SOME INSTABILITY IN PLACE OVER THE AREA WHICH WILL ALLOW A FEW CELLS TO BURST UP TO STRONG CATEGORY WITH STRONG GUSTY WINDS. HAVE SLIGHTLY BUMPED UP POPS TODAY...MAINLY TO ACCOUNT FOR ACTIVITY THAT SHOULD BE GOING ON THIS MORNING. AFTER IT DISSIPATES... DEVELOPMENT OF AFTERNOON SHOWERS AND A FEW THUNDERSTORMS WILL STILL BE POSSIBLE AS INSTABILITY REMAINS IN PLACE. COLD FRONT WILL STILL BE PUSHING SOUTH THROUGHOUT THE NIGHT AND SHOULD BE REACHING THE COAST BY 12Z MONDAY. HAVE TRIMMED POPS FURTHER SOUTH FOR THE MORNING PERIOD SO THAT ONLY COASTAL PARISHES AND OFFSHORE WATERS HAVE WORDING OF RAIN IN THE ZONES. LONG TERM... WEAK UPPER LEVEL RIDGING WILL BUILD INTO THE AREA MID WEAK AS UPPER TROUGH EJECTS. SUBSEQUENTLY...RAIN CHANCES WILL DROP OFF MONDAY AFTERNOON THROUGH WEDNESDAY. IN ADDITION...DAYTIME HIGHS WILL BE ON THE RISE AS HEIGHTS INCREASE. TEMPS SHOULD MAKE IT TO THE 90 TO 93 DEGREE MARK FAIRLY EASILY. AN UPPER TROUGH WILL TRACK ACROSS THE UPPER MISSISSIPPI VALLEY IN THE LATTER PORTION OF THIS WEEK. THIS WILL BREAKDOWN THE EAST SIDE OF UPPER RIDGE OVER THE GULF COAST THUS ALLOWING FOR AFTERNOON SHOWERS AND THUNDERSTORMS TO BEGIN DEVELOPING AGAIN. MEFFER AS HAS BEEN THE CASE FOR SEVERAL NIGHTS...THE OVERNIGHT AVIATION PROBLEM WILL BE THE DEVELOPMENT OF LOW CLOUDS. SEEING SOME DEVELOPMENT IN THE FL015-FL025 RANGE...MOST NOTABLY AT KHUM...AT THIS TIME. EXPECT SCT-BKN CLOUDS TO BECOME WIDESPREAD ACROSS THE AREA BY 09Z AND REMAIN THROUGH ABOUT 15Z. ONE OR TWO SITES WILL LIKELY FALL INTO THE IFR RANGE...PROBABLY AT KMCB. THE OTHER PROBLEM WILL BE THE TIMING OF CONVECTION ASSOCIATED WITH THE FRONTAL BOUNDARY. CURRENT MOVEMENT APPEARS TO BE ABOUT 340/17 KTS. THIS WILL ALLOW CONVECTION TO REACH KMCB AND KBTR SOMETIME AROUND SUNRISE...ALTHOUGH A STRAY SHOWER OR TWO COULD REACH KMCB BEFORE THEN. EXPECT A WEAKENING TREND FROM WHAT IS BEING OBSERVED AT THIS TIME. WILL LEAD INTO EVENT WITH MENTION OF VCSH/VCTS AND CARRY ABOUT A 4 HOUR WINDOW WITH THE MAIN CONVECTION. FOR NOW...WILL ONLY USE TEMPO GROUPS AT KMCB...KBTR AND KHDC. WILL ADJUST LATER AS WE CAN BETTER ANTICIPATE TIMING AT TERMINALS FARTHER SOUTH AND EAST. STILL NOT CONFIDENT ON EXACTLY HOW FAR SOUTHWARD FRONT WILL MAKE IT ON SUNDAY BEFORE RUNNING OUT OF PUSH. WIND FIELD WILL LIKELY BECOME RATHER WEAK TOWARD EVENING. 35 MARINE... WIND FIELD IS CONSIDERABLY WEAKER THIS MORNING THAN IT HAS BEEN FOR SEVERAL DAYS. WITH A WEAKENING COLD FRONT ANTICIPATED TO MOVE INTO THE AREA TODAY...WIND FIELDS WILL BECOME EVEN LIGHTER. WIND DIRECTIONS WILL BE RATHER VARIABLE...BUT GENERALLY WITH AN EASTERLY COMPONENT. NOT EXPECTING WINDS TO BE MUCH ABOVE 10 KNOTS BEFORE THURSDAY...WITH THE POSSIBLE EXCEPTION OF THE USUAL EVENING DIURNAL MAXIMUM. EVEN THEN...DO NOT ANTICIPATE WINDS STRONG ENOUGH TO REQUIRE HEADLINES. 35 DECISION SUPPORT... DSS CODE...BLUE. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...SLURRY SUPPORT. MONITORING RIVER FLOODING. MONITORING CONVECTIVE TRENDS. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 81 66 88 63 / 50 20 10 10 BTR 82 68 89 67 / 50 20 10 10 ASD 83 70 90 69 / 70 30 10 10 MSY 82 73 89 72 / 70 30 10 10 GPT 84 71 89 69 / 70 30 10 10 PQL 86 71 88 68 / 70 30 10 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 PM EDT SUN JUN 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 520 AM EDT SUN JUN 2 2013 WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM NW ONTARIO INTO THE CNTRL GREAT LAKES. A SHORTWAVE SUPPORTING OVER NRN LAKE MICHIGAN INTO NW LOWER MI SUPPORTED AN AREA OF RAIN OVER ERN UPPER MI THAT WAS SLOWLY SLIDING OFF TO THE EAST. SCT LIGHT SHOWERS ALSO LINGERED OVER CNTRL UPPER MI. AT THE SFC...A TIGHT GRADIENT BETWEEN LOW PRES OVER LAKE HURON AND A RIDGE INTO THE NRN PLAINS SUPPORTED BRISK NRLY WINDS ACROSS LAKE SUPERIOR INTO THE UPPER MI. UPSLOPE NRLY FLOW INTO THE HIGHER TERRAIN ALSO SUPPORTED AREAS OF DRIZZLE. MUCH COLDER AIR HAS MOVED INTO THE REGION WITH TEMPS DROPPING INTO THE UPPER 30S AND LOWER 40S. TODAY...ALTHOUGH THE NAM AND HIGH RES MODELS SHOW LOW LEVEL DRYING WILL SPREAD THROUGH MOST OF THE CWA THIS MORNING...UPSTREAM CLOUDS TRENDS SUGGEST THAT THE CLEARING TREND MAY BE SLOWER. ANY LINGERING LIGHT SHOWERS OR DRIZZLE SHOULD END BY MID OR LATE MORNING WITH CLEARING FROM WEST TO EAST BY EARLY TO MID AFTERNOON. EVEN WITH SUNSHINE...WITH N FLOW ACROSS LAKE SUPERIOR AND 850 MB TEMPS NEAR -1C...TEMPS WILL STRUGGLE INTO THE UPPER 40S TO LOWER 50S NORTH AND INTO THE MID AND UPPER 50S SOUTH. TONIGHT...SFC HIGH PRES BUILDING INTO THE REGION FROM THE WEST SUNDAY NIGHT WILL RESULT IN IDEAL RADIATIONAL COOLING CONDITIONS OVER THE WESTERN INTERIOR OF THE CWA WHERE MIN TEMPS WILL LIKELY FALL INTO LOWER 30S...NEAR THE LOWER END OF GUIDANCE. SOME TRADITIONAL COLD SPOTS COULD ALSO SEE READINGS INTO THE UPPER 20S. SO...A FROST ADVISORY WAS ISSUED FOR INLAND PORTIONS OF THE WEST HALF OF UPPER MICHIGAN. A VORTEX DESCENDING FROM NRN ONTARIO IS EXPECTED TO GRAZE NE LAKE SUPERIOR. ALTHOUGH PCPN AND CLOUDS WITH THIS FEATURE ARE EXPECTED TO REMAIN THE NE OF THE CWA...THE VORTEX WILL RESULT IN NW WINDS STRONG ENOUGH TO MAINTAIN SOME BOUNDARY LAYER MIXING AND PREVENT TEMPS FROM DROPPING OFF AS FAR AS IN THE WEST. LOOK FOR MAINLY MID TO UPPER 30S MIN TEMPS OVER THE EAST HALF. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 343 AM EDT SUN JUN 2 2013 UPPER TROUGH THAT IS CURRENTLY AFFECTING THE UPPER GREAT LAKES EARLY THIS MORNING WILL BE SHIFTING EAST THROUGH EASTERN CANADA ON MONDAY. THIS WILL LEAD TO THE AREA BEING UNDER NORTHWEST FLOW ALOFT AND A SURFACE HIGH PRESSURE RIDGE FROM A HIGH CENTERED IN SOUTH CENTRAL CANADA. WITH DRY LOW AND MID LEVELS UNDER THE HIGH PRESSURE RIDGE...EXPECT A MOSTLY SUNNY SKY ACROSS MUCH OF THE LAND AREA. THERE COULD BE SOME LINGERING CLOUDS OVER NORTHEAST LAKE SUPERIOR AND FAR EASTERN UPPER MICHIGAN AS THE UPPER TROUGH DEPARTS. WITH THE SUNSHINE...EXPECT MIXING TO AROUND 850-825MB. BUT WITH TEMPERATURES AT THAT LEVEL ONLY AROUND 2C WEST AND -1C EAST...BELOW NORMAL HIGHS ARE EXPECTED AND ONLY IN THE 50S AND LOWER 60S. THE COOLEST TEMPERATURES WILL BE ALONG THE GREAT LAKES SHORELINES DUE TO LAKE BREEZES. THE OTHER ITEM TO MENTION FOR MONDAY WILL BE LOW RH VALUES. ML DEWPOINTS FROM THE MODELS INDICATE VALUES IN THE MID 20S OVER THE INTERIOR LOCATIONS AND POTENTIALLY THE UPPER TEENS IF THE GFS IS CORRECT. WITH THAT CONSISTENCY AND THE TRENDS IN THE MAV/MET...HAVE LOWERED OUR DEWPOINTS A GOOD 5-7 DEGREES. THIS PRODUCES RH VALUES OF 25-35 PERCENT OVER THE INLAND AREAS...WITH THE LOWEST VALUES OVER THE WEST. FORTUNATELY...THE WET WEATHER RECENTLY...GREEN UP WELL ON IT/S WAY OR EVEN DONE...AND BELOW NORMAL TEMPERATURES REDUCES FIRE WEATHER CONCERNS EVEN WITH 10-15KT WINDS. THE HIGH PRESSURE RIDGE WILL STILL BE OVER THE AREA ON MONDAY NIGHT AS AN UPPER RIDGE SLIDES ACROSS THE AREA. THE CLEAR SKIES...LIGHT WINDS...AND PWAT VALUES AROUND 30-40 PERCENT OF NORMAL WILL LEAD TO A COLD NIGHT ACROSS THE AREA. WILL CONTINUE THE TREND OF GOING BELOW GUIDANCE VALUES AND HAVE LOWS AROUND 30 OVER THE INTERIOR LOCATIONS. RECORD LOWS FOR JUNE 4 ARE IN THE MID-UPPER 20S...SO WE WILL BE CLOSE BUT LIKELY STAY ABOVE THE RECORD LOWS. WILL ALSO CONTINUE THE MENTION OF FROST FOR MONDAY NIGHT ALONG WITH HIGHLIGHTING IN HWO. AREA WILL STILL BE UNDER THE INFLUENCE OF THE HIGH ON TUESDAY...AS IT DRIFTS SOUTHEAST ACROSS THE CWA THROUGH THE DAY. THIS WILL LEAD TO LIGHTER WINDS ACROSS THE AREA. DO EXPECT TO SEE SOME HIGH CLOUDS STREAMING EAST ACROSS THE WESTERN CWA DURING THE AFTERNOON AHEAD OF THE NEXT SYSTEM APPROACHING THE AREA. HIGHS WILL BE A LITTLE WARMER ON TUESDAY...AS 850MB TEMPS WARM A COUPLE DEGREES FROM MONDAY. WITH THE RIDGE LINGERING OVER THE EAST...HAVE LOWERED TD VALUES SIGNIFICANTLY OVER THE EAST HALF. THIS WILL LIKELY LEAD TO ANOTHER LOW RH DAY...BUT AS WITH MONDAY...FIRE WX CONCERNS ARE LIMITED WITH EVEN LIGHTER WINDS. THE UPPER TROUGH CURRENTLY OVER BRITISH COLUMBIA WILL BE MOVING THROUGH THE NORTHERN PLAINS ON TUESDAY AND THEN BECOME CLOSE ENOUGH TO START INFLUENCING THE UPPER GREAT LAKES FOR TUESDAY NIGHT AND CONTINUING INTO THURSDAY. THERE ARE STILL QUESTIONS ON THE EXACT TRACK OF THE SHORTWAVE TROUGH...WHICH IN TURN AFFECTS THE LOCATION OF THE SURFACE LOW AND RESULTANT WARM AIR ADVECTION PRECIPITATION. LATEST IDEA FROM THE GFS/ECMWF IS THAT MUCH OF THE INITIAL PRECIPITATION WILL BE WEST OF THE AREA TUESDAY EVENING AND THEN SLIDE OVER THE AREA TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY NIGHT AS THE SURFACE LOW/TROUGH SLIDES FROM THE DAKOTAS INTO SOUTHWEST WISCONSIN. THE WARM AIR ADVECTION IS FAIRLY BROAD AND WEAK...SO WOULD EXPECT THE PRECIPITATION TO BE GENERAL LIGHT SHOWERS. WITH THE BEST FORCING FOCUSED OVER WISCONSIN AND THE SOUTHERN HALF OF THE CWA...HAVE THE HIGHEST POPS IN THAT AREA. SINCE THE BULK OF THE FORCING IS SOUTH OF THE AREA...WILL KEEP POPS IN THE HIGH CHANCE CATEGORY SINCE IT IS ENTIRELY POSSIBLE MUCH OF THE RAIN STAYS IN WISCONSIN. THUNDER CHANCES ARE LIMITED TO NON-EXISTANT...AS SHOWALTER VALUES ARE WELL ABOVE ZERO AND MUCAPE VALUES STAY BELOW 100 J/KG DURING THIS PERIOD. EXPECT A DIMINISHING TREND IN THE PRECIPITATION FOR THURSDAY INTO THURSDAY NIGHT...AS THE DISTURBANCE SHIFTS EAST AND HIGH PRESSURE NEAR HUDSON BAY PUSHES DRIER AIR INTO THE AREA. THIS SHOULD LEAD TO DRY WEATHER FOR FRIDAY...BUT ANOTHER WEAK SHORTWAVE TRIES TO SLIDE EAST ACROSS THE AREA FOR SATURDAY. WITH THE DRY EASTERLY FLOW AND THE POTENTIAL THE HIGH REMAINS IN PLACE...IT/S ARRIVAL MAY BE DELAYED SOME. TEMPERATURES FROM MID WEEK ON WILL CONTINUE THE BELOW NORMAL TREND...WITH HIGHS GENERALLY IN THE 50S-60S AND THE COOLEST DAY ON WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 134 PM EDT SUN JUN 2 2013 GUSTY NNW WINDS WILL SLOWLY DIMINISH THROUGH THE REMAINDER OF THE AFTERNOON HOURS...AND FALLING TO AROUND 8KTS OR LESS OVERNIGHT /STRONGEST AT CMX/. EXCLUDING INITIALLY AT SAW...VFR CEILINGS AND VIS WILL BE THE RULE THROUGH MONDAY...WITH ANOTHER ROUND OF INCREASED NW WINDS WITH GUSTS IN THE TEENS SHORTLY AFTER DAYBREAK MONDAY. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 520 AM EDT SUN JUN 2 2013 LOW PRESSURE OVER GEORGIAN BAY WILL SHIFT ENE INTO QUEBEC BY THIS AFTERNOON...WHILE A RIDGE OF HIGH PRESSURE BUILDS OVER NORTHERN ONTARIO. AS A RESULT...NORTH WINDS WILL DIMINISH TODAY. RIDGING WILL EXTEND OVER LAKE SUPERIOR TONIGHT...WHICH WILL REMAIN THROUGH MUCH WEDNESDAY AS THE NEXT LOW WILL SLIDES ACROSS THE NORTHERN PLAINS. THE LOW WILL SHIFT SLOWLY E INTO THE MID MS VALLEY THURSDAY...WHILE THE WEAK RIDGE OF HIGH PRESSURE LINGERS OVER LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... FROST ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 8 AM EDT /7 AM CDT/ MONDAY FOR MIZ002-004-005-009>011-084. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...SRF AVIATION...KF MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
120 PM CDT SUN JUN 2 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM CDT SUN JUN 2 2013 EARLY MORNING SURFACE ANALYSIS REVEALED A BROAD RIDGE OF HIGH PRESSURE ACROSS THE DAKOTAS. THIS HIGH WAS LOCATED BENEATH AN UPPER LEVEL RIDGE LOCATED JUST UPSTREAM OVER EASTERN MONTANA. OVER THE NEXT 24 HOURS THIS HIGH WILL SLOWLY MIGRATE EASTWARD BRINGING SOME MUCH ANTICIPATED DRY WEATHER. HOWEVER...AFTERNOON TEMPERATURES WILL REMAIN COOL AS H850 TEMPS LINGER IN THE 2 TO 4C RANGE. BOTH THE RAP AND NAM BUFR SOUNDINGS SHOW MIXING UP TO AROUND 800MB WITH SATURATION AT THE TOP OF THE BOUNDARY LAYER. THEREFORE USED THE MIXDOWN TOOL FOR HIGH TEMPERATURES THIS AFTERNOON. ALSO INCLUDED SOME AFTERNOON CLOUDS ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA IN ANTICIPATION OF SOME FLAT CU DURING PEAK HEATING. THESE CLOUDS WILL QUICKLY DISSIPATE AFTER SUNSET SETTING THE STAGE FOR RADIATIONAL COOLING AND ANOTHER CHILLY NIGHT ACROSS THE REGION. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 342 AM CDT SUN JUN 2 2013 NORTHWEST UPPER FLOW WILL PREDOMINATE THROUGH THE PERIOD... KEEPING THINGS A BIT COOL ACROSS OUR AREA WITH NO REAL SEVERE WEATHER CONCERNS. THERE ARE CERTAINLY SOME DIFFERENCES IN THE DETAILS BETWEEN THE ECMWF AND GFS AND THEIR RESPECTIVE ENSEMBLES... BUT IN GENERAL THERE IS GOOD AGREEMENT ON THE EVOLUTION OF THE LARGE SCALE PATTERN THROUGH THE WEEK. ONE UPPER WAVE WILL SLOWLY MIGRATE ACROSS THE AREA TUESDAY AND WEDNESDAY... WITH WEAK RIDGING FOR THURSDAY INTO EARLY FRIDAY... THEN AN UPPER WAVE WILL SLOWLY WORK IN FROM THE NORTHERN PLAINS AS WE MOVE INTO THE UPCOMING WEEKEND. ALLOWED FOR SOME LOW POPS TO WORK INTO THE WESTERN PART OF THE FORECAST AREA ON MONDAY AS WE GET ON THE BACKSIDE OF THE SURFACE RIDGE AND START TO SEE SOME WARM ADVECTION DEVELOP OVER THE WESTERN PART OF THE AREA. CHANCES FOR PCPN WILL THEN SPREAD EASTWARD MONDAY NIGHT THROUGH TUESDAY AS A SURFACE LOW NEAR THE NORTHERN END OF AN INVERTED TROUGH WORKS ITS WAY FROM THE DAKOTAS ACROSS MICHIGAN. A LOOK AT 850-500MB DIFFERENTIAL THETA-E AND BEST LIFTED INDICES SHOWS ELEVATED INSTABILITY SLIGHTLY LAGGING THE INITIAL WARM ADVECTION AND MOISTURE RETURN... SO SHOULD SEE SHOWER CHANCES AT FIRST GIVE WAY TO THE CHANCE FOR SHOWERS WILL SOME EMBEDDED THUNDER. SEVERE WEATHER THREAT LOOKS LOW THROUGH THE WEEK GIVEN GENERALLY MEAGER INSTABILITY UP INTO OUR AREA... WITH THE MAIN BAROCLINIC ZONE REMAINING WELL TO THE SOUTH. HOWEVER... THERE IS VERY STRONG DEEP LAYER SHEAR MIGRATING ACROSS ON TUESDAY AHEAD OF THE AFOREMENTIONED SURFACE LOW... SO SHOULD INSTABILITY MANAGE TO BE BETTER THAN THE FEW HUNDRED J/KG ADVERTISED BY THE NAM AND GFS THEN THERE COULD BE SOME CONCERNS. HOWEVER... THE BETTER SHEAR... BOTH LOW-LEVEL AND DEEP LAYER... LOOKS LIKE IT WILL OUTPACE WHERE THE BETTER INSTABILITY WILL OCCUR ON TUESDAY... WHICH SHOULD FURTHER MITIGATE ANY POTENTIAL. MAIN CONCERN IF INSTABILITY WERE CLOSER TO 500 J/KG AND BETTER ALIGNED WITH SHEAR WOULD BE LOW-TOPPED SUPERCELL POTENTIAL... BUT AT THIS POINT THINGS DON/T APPEAR TO BE COMING TOGETHER TOO WELL FOR THAT. PCPN CHANCES WILL LINGER ACROSS THE AREA TUESDAY NIGHT INTO WEDNESDAY AS THE UPPER WAVE AND FILLING SURFACE LOW SLIDE ACROSS THE AREA. A BIT OF A BACKDOOR COLD FRONT AND RIDGE OF HIGH PRESSURE WILL WORK INTO THE AREA THURSDAY INTO FRIDAY... WHICH SHOULD BRIEFLY REDUCE CHANCES FOR ANY PCPN OVER THE AREA. HOWEVER... GIVEN THE ADVERTISED COOL 700-500MB TEMPERATURES AND POTENTIAL FOR DECENT LAPSE RATES WITH ANY SUNSHINE... WE COULD CERTAINLY WIND UP WITH SOME SHRA IF THERE ISN/T SUFFICIENT RIDGING AND LOW LEVEL SUBSIDENCE. SO... WENT WITH LOWER OR NO POPS THURSDAY AND FRIDAY FARTHER NORTH WHERE RIDGING LOOKS LIKE IT SHOULD BE MORE PREVALENT... BUT KEPT SLIGHTLY HIGHER CHANCES FARTHER SOUTH. DIDN/T INCLUDE ANYTHING FOR THURSDAY NIGHT... SINCE IT SEEMS ANY POTENTIAL WOULD BE DIURNALLY DRIVEN. BY SATURDAY... WE MAY SEE CHANCES FOR MORE WIDESPREAD PCPN START TO WORK IN FROM THE WEST AS WE ONCE AGAIN GET ONTO THE BACKSIDE OF THE SURFACE HIGH AND START TO SEE SOME WARM ADVECTION AND MOISTURE RETURN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1251 PM CDT SUN JUN 2 2013 LARGE AREA OF LOW VFR STRATO-CU NOTED OVER PORTION OF WEST CENTRAL WI AND OVER LARGE SECTION OF WEST CENTRAL MN. EXPECT BOTH AREAS TO MOSTLY DISINTEGRATE BY 00Z AS HEATING WANES. MODERATE NW FLOW WILL ALSO FADE BY THE EARLY EVENING AT ALL SITES. SURFACE RIDGE WILL CONTINUE ACROSS THE ENTIRE REGION INTO MON/12Z TIME FRAME. NEW STORM SYSTEM WILL BEGIN TO ENTER WESTERN SODAK THIS TIME FRAME...AND THEN TREK INTO WESTERN NE BY 04/00Z. CIRRUS SHIELD WILL OVERSPREAD MOST AIRPORT SITES BY EARLY MONDAY AFTERNOON...AS WARM FRONTAL BOUNDARY OVER WEST CENTRAL AND SOUTHWEST MN GENERATES SCT -SHRA NEAR KAXN BY 05/00Z. LIGHT SE FLOW WILL BE ENCOUNTERED OVER SOUTHERN MN MONDAY MORNING...INCREASING AS SURFACE GRADIENT INCREASES AHEAD OF STORM SYSTEM DURING THE AFTN. WEST CENTRAL TAF SITES WINDS WILL BE LIGHT AND VRBL BECOMING LIGHT SE BY END OF PERIOD. VFR CIGS AND VSBYS THROUGH END OF PERIOD ALL LOCATIONS. KMSP... HEATING INDUCED STRATO-CU DECK COULD BECOME BKN BETWEEN 19-22Z ...WITH FAIRLY RAPID BREAKUP ANTICIPATED BY 23Z. MDT SE FLOW BECOMES LIGHT BY LATE AFTN AND RETURNS BY 03/16Z. MID LEVEL CLOUD DECK AHEAD OF APPROACHING CYCLONE MENTIONED ABOVE WILL BE ENCOUNTERED LATE IN PERIOD. VFR CIGS AND VSBYS THROUGH END OF PERIOD. LIGHT SHOWER VCNTY POSSIBLE NEAR 04/06Z. /OUTLOOK FOR KMSP/ MON...VFR WITH -SHRA LATE. WINDS SE AT 10KTS. TUE...MVFR WITH -SHRA/TSRA LIKELY. WINDS ESE AT 10G20KTS. WED...VFR WITH MVFR/TSRA POSSIBLE. WINDS NNE AT 10KTS. THU...VFR WITH MVFR/ISOLATED TSRA POSSIBLE. WIND E 6-10KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...JRB LONG TERM... AVIATION...AJZ
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1238 PM CDT SUN JUN 2 2013 .AVIATION... 18Z TAFS FOR KOMA...KLNK AND KOFK. CIGS FL040 ALONG THE MISSOURI RIVER WILL CONTINUE TO SHIFT EAST OUT OF THE AREA. VFR CONDITIONS ARE EXPECTED TO CONTINUE...HOWEVER WILL NEED TO MONITOR LOW LEVEL MOISTURE. RAP/NAM ARE HINTING THAT AS WEAK FLOW BECOMES SOUTHEAST...SOME OF THAT MOISTURE WILL TRY TO RETURN AND A BAND OF STRATUS COULD DEVELOP. AFTER 12Z...SOUTHEAST SURFACE WINDS WILL BEGIN TO RAMP UP TO 10 TO 20 KTS AND GUSTY BY LATE MONDAY MORNING. && .PREV DISCUSSION... /ISSUED 302 AM CDT SUN JUN 2 2013/ DISCUSSION... MAIN FORECAST CHALLENGE WAS WHEN TO INCLUDE TSTM CHANCES AS ANOTHER UPPER TROUGH/LOW MOVES FROM SWRN CANADA ACROSS NORTHERN PLAINS THROUGH MIDWEEK. FOR TODAY...UPPER RIDGE AHEAD OF SWRN CANADIAN LOW TO FLATTEN AS IT BUILDS ACROSS CNTRL PLAINS AS UPPER LOW SOUTH OF HUDSONS BAY DROPS SOUTH. PERSISTENT LOW CLOUDS HAVE CLEARED WRN ZONES AS OF 730Z AND SHOULD CONTINUE TO DO SO THROUGH THIS MORNING...ALTHOUGH LATEST RAP SOUNDING DELAYED THIS CLEARING ALONG/E OF MO RIVER TILL AFTERNOON. SLOWED CLEARING DOWN A BIT E...AND FURTHER ADJUSTMENTS MAY BE NEEDED. MILDER TEMPS COMPARED TO SATURDAY BUT STILL BELOW NORMAL AND GENERALLY A DEG OR TWO BELOW GUIDANCE BASED ON PERHAPS HINDERED MIXING FROM MORNING/EARLY AFTN CLOUDS E AND/OR SLIGHTLY COOLER H85 TEMPS PER 00Z ECMWF. UPPER LOW MOVING TOWARD DAKOTAS LATE MONDAY WILL STRENGTHEN LOW LEVEL JET LATE TONIGHT INTO MONDAY NIGHT. THIS WILL PROVIDE INCREASING WINDS...ESPECIALLY MONDAY. HOWEVER...WINDS PROBABLY WILL NOT INCREASE QUICKLY ENOUGH TONIGHT TO HELP LOWS MUCH WITH GUIDANCE GENERALLY ACCEPTABLE. STORMS THAT DEVELOP TO OUR WEST LATE TONIGHT AIDED BY THETA E ADVECTION IN LOW LEVEL JET AXIS COULD MOVE ACROSS SECTIONS OF THE AREA MONDAY MORNING...FOR NOW CONFINED SLGT CHC POPS TO FAR N. OTHERWISE KEPT MONDAY AFTN DRY. BOOSTED WIND SPEEDS MONDAY TO JUST BELOW WIND ADVISORY CRITERIA NWRN ZONES. MAX TEMPERATURES PROBABLY A CATEGORY OR SO WARMER MOST AREAS LOOKS FINE. INCREASING POPS MONDAY NIGHT INTO TUESDAY STILL ON TRACK AS UPPER LOW SHIFTS SE A BIT AND LOW LEVEL JET/CONVERGENCE SHIFTS INTO THE FORECAST AREA MONDAY NIGHT FOLLOWED BY A COLD FRONT TUESDAY. ALTHOUGH SOME ADJUSTMENTS WERE MADE AND MORE WILL PROBABLY BE ADDRESSED IN LATER FORECASTS...IT APPEARS HIGHER POPS WILL BE SHIFTING TOWARD ERN ZONES THRU LATE TUESDAY. IF CLOUDS/SHOWERS REMAIN WIDESPREAD TUE MAX TEMPS MAY NEED LOWERING. CONFIDENCE IS LOW IN HOW SCENARIO TUE NIGHT/WED PLAYS OUT AS A WAVE ROTATING AROUND UPPER LOW COULD HELP GENERATE MCS TO OUR WSW IN UPSLOPE REGION ACROSS WRN HIGH PLAINS BY WED AM. SOME OF THIS ACTIVITY COULD SKIRT AREA WED...SPCLY SOUTH...AND LOW CHC POPS WERE CARRIED GENERALLY ALONG/S OF HIGHWAY 30. HOWEVER...WE COULD ALSO SEE JUST MAINLY CLOUDS FROM THIS...BUT EITHER PRECIP OR CLOUDS COULD IMPACT HIGHS. FOR NOW THEY WERE KEPT IN THE 70S TUE AND WED. THURSDAY LOOKED DRY WITH INCREASING TSTM CHANCES AGAIN FROM W TO E FRIDAY INTO SATURDAY AS NEXT TROUGH APPROACHES. NO CHANGES MADE FROM MODEL/PREVIOUS FORECAST BLEND. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS BUFFALO NY
335 PM EDT SUN JUN 2 2013 .SYNOPSIS... A COLD FRONT WILL DROP ACROSS THE REGION...USHERING IN COOLER AIR TONIGHT. THEN CANADIAN HIGH PRESSURE WILL BUILD TOWARD THE REGION WITH COOL AND DRY WEATHER THROUGH MID-WEEK. && .NEAR TERM /THROUGH MONDAY/... FOR THE REMAINDER OF THE AFTERNOON...EXPECT MAINLY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY...WITH RADAR SHOWING MOST OF THIS ACROSS INTERIOR SECTIONS. FOLLOWING THE HRRR AND OTHER HIGH RESOLUTION GUIDANCE...THESE WILL PROBABLY CONTINUE TO TRACK TO THE EAST BEFORE FALLING APART TOWARD SUNSET. MEANWHILE...THE BRISK SW FLOW IS SHADOWING THE NIAGARA FRONTIER FROM BUFFALO TO ROCHESTER...EXTENDING NE ACROSS LAKE ONTARIO AND TO WATERTOWN. IN THESE AREAS...EXPECT WIND GUSTS TO 40 MPH FOR DURING THE AFTERNOON HOURS. MEANWHILE...THE COLD FRONTAL BOUNDARY IS STILL JUST TO THE NORTH OF LAKE ONTARIO...WITH SHOWERS AND A FEW THUNDERSTORMS ALONG THIS BOUNDARY. THE FRONT WILL DROP TO THE SOUTH...REACHING THE SOUTH SHORES OF LAKE ONTARIO JUST SHY OF SUNSET. EXPECT SHOWERS TO WEAKEN WITH LAKE SHADOWING AND THE LOSS OF DAYTIME HEATING...BUT THERE STILL IS A CHANCE OF A SHOWER ACROSS THE NIAGARA FRONTIER EARLY THIS EVENING. THE FRONT WILL CONTINUE TO DROP SOUTHWARD OVERNIGHT...BUT PROBABLY WILL BE DRY WITH ITS MAIN INFLUENCE BEING A WIND SHIFT TO THE NW AND NOTABLY COOLER TEMPERATURES. THE RESULT WILL BE A NOTICEABLE COOLER NIGHT...WITH TEMPERATURES DOWN INTO THE 40S BY DAYBREAK. EXPECT A GRADUAL CLEARING TREND TONIGHT...WITH CLOUDS LINGERING LONGEST ACROSS THE SOUTHERN TIER AND EAST OF LAKE ONTARIO. HIGH PRESSURE WILL RIDGE EASTWARD INTO THE REGION ON MONDAY...AS AN UPPER LEVEL LOW IS FORECAST TO REMAIN WELL TO THE NORTH. AFTER SOME LINGERING MORNING CLOUDS...EXPECT CLOUDS TO SCATTER OUT AND GIVE WAY TO QUITE A BIT OF AFTERNOON SUNSHINE. DESPITE THE SUN...THE AIR MASS WILL BE QUITE COLD...WITH HIGHS ONLY IN THE 60S. && .SHORT TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/... DRY AND COOLER WEATHER WILL START THIS PERIOD AS HIGH PRESSURE CENTERED OVER WESTERN HUDSON BAY RIDGES SOUTH ACROSS THE GREAT LAKES AND INTO NEW YORK STATE. CLEAR SKIES AND MUCH LOWER DEWPOINTS WILL ALLOW OVERNIGHT TEMPERATURES TO FALL TO THE LOWER TO MIDDLE 40S... EVEN SOME UPPER 30S POSSIBLE IN THE SOUTHERN TIER VALLEYS AND BLACK RIVER VALLEY. THE AIRMASS WILL MODIFY A BIT ON TUESDAY WITH A LITTLE MORE MOISTURE AND SLIGHTLY WARMER TEMPS. FORECAST SOUNDINGS FOR TUESDAY SHOW A STRONG SUBSIDENCE INVERSION WHICH SHOULD SUPPRESS MOST IF NOT ALL CLOUDINESS...ALTHOUGH MID AND HIGH CLOUDS STREAMING IN FROM THE WEST MAY CLUTTER THE SKY LATE IN THE DAY. HIGH TEMPS ON TUESDAY WILL BE IN THE LOWER TO MID 60S ACROSS HIGHER ELEVATIONS AND MID 60S TO AROUND 70 FOR THE LAKE PLAINS. WEDNESDAY WILL BE SIMILAR TO TUESDAY...A BIT MORE MID CLOUD COVER AND WARMER TEMPS IN THE MID TO UPPER 60S ACROSS THE EASTERN LAKE ONTARIO REGION AND THE LOWER TO MID 70S ELSEWHERE. AN INVERTED SURFACE TROUGH SETS UP ACROSS THE REGION LATE WEDNESDAY NIGHT THROUGH...ESSENTIALLY A SLOW MOVING WARM FRONT...AND BRINGS AN INFLUX OF WARM AND MOIST AIR WITH AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. THE ROUGH TRANSLATES SLOWLY TO EAST THROUGH THIS PERIOD AND SHOWS SIGNS OF STRENGTHENING AS A LOW LEVEL 40KT JETS SETS UP LATE THURSDAY NIGHT...INDICATING THE RISK OF STRONGER THUNDERSTORMS AND HEAVIER RAINS ACROSS CENTRAL AND NORTHERN NY. TEMPS ON THURSDAY WILL BE IN THE MIDDLE 60S TO THE LOWER 70S... LIMITED BY THE CLOUD COVER AND PRECIP. LOWS THURSDAY NIGHT WILL BE MILDER WITH THE WARM ADVECTION ON MORE SOUTHERLY WINDS...READINGS IN THE LOWER TO MID 50S. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AN UPPER TROUGH WILL CROSS THE REGION DURING THIS PERIOD WITH A BROAD REGION OF LOWER SURFACE PRESSURE AND WARMER/HUMID AIR IN PLACE. WILL KEEP CHANCE POPS ACROSS THE AREA FOR FRIDAY AND FRIDAY NIGHT...THEN TRENDING TO LOWER CHANCE OR SLIGHT CHANCE POPS AS A DRIER NORTHEASTERLY FLOW DEVELOPS FOR SATURDAY AND SUNDAY. TEMPERATURES DURING THIS PERIOD WILL CLOSE TO...OR JUST A BIT ABOVE NORMAL WITH HIGHS GENERALLY IN THE MID 70S AND LOWS IN THE MID TO UPPER 50S. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... THE BACK EDGE OF THE STEADIER RAIN HAS MOVED WELL EAST OF THE REGION. BEHIND THIS THERE WILL BE SOME SCATTERED DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS THIS AFTERNOON...BUT THESE ARE UNLIKELY TO IMPACT TAF LOCATIONS...WITH MOST OF THIS ACTIVITY FORECAST TO BE ACROSS INTERIOR SECTIONS. OTHERWISE...THE MAIN IMPACT DURING THIS TIME WILL BE GUSTY SW WINDS GUSTING 30 TO 35 KTS. A COLD FRONT WILL DROP SOUTHWARD ACROSS THE REGION ROUGHLY AROUND 00Z. THIS MAY SPARK A SHOWER...AND WILL KEY A WIND SHIFT TO THE W-NW. A BRIEF PERIOD OF MVFR CIGS ARE POSSIBLE BEHIND THE FRONT...WITH CIGS LIKELY TO LIFT AND SCATTER DURING THE DAY ON MONDAY. LEFT OVER MOISTURE MAY RESULT IN BRIEF BKN MVFR CIGS...BUT THESE WOULD BE VERY SHORT LIVED AS DRIER AIR MIXES IN. OUTLOOK... MONDAY NIGHT THROUGH WEDNESDAY...VFR. THURSDAY AND FRIDAY...MVFR/VFR. A CHANCE OF SHOWERS AND THUNDERSTORMS. && .MARINE... AN AREA OF LOW PRESSURE WILL TRACK NORTH OF LAKE ONTARIO TODAY AND DRAG A COLD FRONT EAST ACROSS THE LAKE THROUGH EARLY EVENING. WHILE WINDS WILL BE STRONGEST ON LAND...WINDS WILL STILL REMAIN IN SMALL CRAFT CRITERIA ON MOST OF THE NEARSHORES AND RIVERS UNTIL ABOUT SUNSET. AFTER THIS...WINDS WILL DIMINISH AS HIGH PRESSURE BUILDS IN THROUGH MID-WEEK. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LEZ020- 040-041. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LOZ042>044. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SLZ022-024. && $$ SYNOPSIS...APFFEL NEAR TERM...APFFEL SHORT TERM...WCH LONG TERM...WCH AVIATION...APFFEL MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
150 PM EDT SUN JUN 2 2013 .SYNOPSIS... A COLD FRONT WILL PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS TODAY ACROSS THE NORTH COUNTRY. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCE STRONG AND DAMAGING WINDS...SMALL HAIL...AND LOCALIZED HEAVY DOWNPOURS. CLEARING AND COOLER TEMPERATURES WILL ARRIVE BY THE START OF THE WORK WEEK. && .NEAR TERM /UNTIL 11 PM THIS EVENING/... AS OF 117 PM EDT SUNDAY...QUICK UPDATE TO FCST FOR CRNT OBS AND ADJUSTED TEMPS UP SEVERAL DEGREES. CRNT RADAR SHOWS SHOWERS/STORMS DEVELOPING ACRS ESSEX COUNTY NY AND THE NORTHERN HUDSON VALLEY REGION...WITH CRNT MOTION TO THE NE AT 25 TO 35 MPH. LATEST LAPS DATA CONTS TO SHOW SFC BASED CAPE VALUES BTWN 1500 AND 2500 J/KG...ACRS CPV AND POINTS EAST. IN ADDITION...BEST DYNAMICS AND LLVL WIND FIELDS ARE APPROACHING OUR WESTERN CWA ATTM. EXPECT AREAL COVERAGE/INTENSITY OF SHOWERS/STORMS TO INCREASE ACRS MOST OF CENTRAL/SOUTHERN VT THIS AFTN. MAIN THREAT WL BE STRONG/DAMAGING WINDS THRU EARLY THIS EVENING. GIVEN CRNT TRENDS...GREATEST THREAT FOR HEAVY RAIN AND POTENTIAL ISOLATED FLASH FLOODING WL BE ACRS THE ESSEX COUNTY NY INTO PARTS OF CENTRAL/SOUTHERN VT. WE WL BE WATCHING THIS POTENTIAL CLOSELY AS WE PROGRESS THRU THE AFTN/EVENING HOURS. REST OF FCST IN GOOD SHAPE. UPDATED ZNS TO REFLECT SVR THUNDERSTORM WATCH #271 FOR EASTERN DACKS THRU VT UNTIL 8 PM THIS EVENING. REST OF FCST IN GREAT SHAPE. UPDATED FCST TO MENTION SHOWERS/STORMS THRU THIS MORNING FOR CENTRAL/NORTHERN VT AND REMOVED MENTION OF ENHANCED WORDING THRU THE MORNING HOURS. ALSO...ADJUSTED TEMPS/DWPTS BASED ON CRNT OBS. FCST CHALLENGE IS TIMING OF CONVECTION TODAY...FOLLOWED BY AREAL COVERAGE/INTENSITY OF STORMS THIS AFTN. WATER VAPOR SHOWS POTENT S/W ENERGY ACRS THE EASTERN GREAT LAKES...WITH ENHANCED RIBBON OF DEEP LAYER MOISTURE AHEAD OF THIS ENERGY ACRS WESTERN NY/PA. IN ADDITION...STRONG HGHT FALLS ARE OCCURRING AS MID/UPPER LVL TROF LIFTS TWD HUDSON`S BAY THIS AFTN AND ASSOCIATED SFC BOUNDARY SWINGS ACRS OUR CWA. AT THE SFC...INITIAL PRE-FRNTAL TROF HAS PRODUCED SHOWERS WITH A FEW EMBEDDED RUMBLES OF THUNDER ACRS THE EASTERN DACKS INTO NORTHERN/CENTRAL VT THIS MORNING. EXPECT SOME CLRING BEHIND THIS INITIAL TROF...WHICH WL AID SFC HEATING. WITH TEMPS WARMING TO NEAR 80F...AND DWPTS IN THE U60S TO L70S...SFC BASED CAPE VALUES WL BE BTWN 2000-2500 J/KG...ESPECIALLY ALONG AND EAST OF THE CPV. EXPECT ANOTHER ROUND OF STORMS TO REDEVELOP BY EARLY THIS AFTN ACRS THE EASTERN DACKS...AND BECOME SEVERE AS THEY ENCOUNTER BETTER INSTABILITY/SHEAR ACRS THE CPV AND MOST OF VT. SOUNDINGS SHOW A MAINLY UNIDIRECTIONAL WIND FLW THRU 500MB...SUPPORTING LINES OF STORMS WITH INDIVIDUAL BOW SEGMENTS POSSIBLE...WITH PRIMARY THREAT BEING STRONG/DAMAGING WINDS. PRE-STORM CHECKLIST SHOWS VERY HIGH 0C LINE AROUND 13KFT THIS AFTN...WHICH INDICATES WE WOULD NEED A 50 TO 55 DBZ TO 35,000 FEET FOR SEVERE HAIL. THEREFORE PRIMARY THREAT WL BE WINDS...AND GIVEN RECENT SATURATED SOILS...SHALLOW ROOTED TREES COULD EASILY BE BLOWN DOWN. STORMS SHOULD CLEAR EASTERN VT BY 8 PM THIS EVENING...BASED ON CRNT RAP AND BTV 4KM REFLECTIVITY PROGS. PREVIOUS DISCUSSION...ACTIVE 24-HR PERIOD EXPECTED FOR TODAY/ TONIGHT AS A CD FRNT WILL BEGIN TO PUSH THRU THE AREA. RW/TRW FROM THE OVERNGT PERIOD STILL SLOWLY PUSHING NORTH THRU CANADIAN BORDER ZONES ATTM AND SHOULD CLR INTO QUEBEC BFR MAIN PRECIP ARRIVES WITH FRNT...WHICH IS ONLY TO OUR WEST OVER WESTERN NY/LK ONTARIO. MANY SPOTS IN THE CWA WILL SEE INSTABILITY INCR DURING THE DAY AS PSUNNY/MSUNNY WILL ENSUE BFR CONVECTION BEGINS TO DEVELOP...ALLOWING FOR INCR IN T/TD THROUGHOUT AREA. THIS COMBINED WITH STRONG SHEAR/LAPSE RATES...LI/S NEARING -4 AND MDL CAPE FROM BUFKIT SHOWING 1500-2000 J/KG POTENTIAL...WILL ALLOW FOR DEVELOPMENT OF STRONG TO SEVERE STORMS FOR TODAY/TNGT. SPC(STORM PREDICTION CENTER) HAS MAJORITY OF CWA UNDER SL RISK FOR SEVERE CONDITIONS SO HAVE MAINTAINED SEVERE/ENHANCED WORDING IN FORECAST. MDL PW/S NEARING 1.25-1.60" IN GENERAL WITH LOCALLY HIR AMTS WILL CREATE QPF AMTS IN GENERAL NEARLY AN INCH FOR ALL AREAS...W/ LOCALLY HIR TOTALS IN HEAVIER DOWNPOURS. W/ SOME AREAS SEEING TRAINING OF RW/TRW OVERNGT...HYDRO CONCERNS WILL BE AN ISSUE TO MONITOR. LATEST MDL TREND IS TO BRING BULK OF PRECIP THRU AREA AFTER MIDNGT TONIGHT. MID-LEVEL DRY AIR WORKING AROUND LOW TO OUR WEST MAY AID IN SHUTTING DOWN PRECIP QUICKER. FOR NOW WILL KEEP PRECIP TRENDING DOWN THRU 12Z MONDAY AS TRAINING POTENTIAL MAY KEEP PRECIP GOING ALONG FRNT A BIT LONGER. TEMP THRU PERIOD NEAR GUIDANCE...ESPECIALLY EASTERN ZONES WHERE NOT AFFECTED BY CLD COVER FROM APPORACHING FRNT. && .SHORT TERM /11 PM THIS EVENING THROUGH TUESDAY/... AS OF 424 AM EDT SUNDAY...GOING INTO MONDAY MORNING...MDLS PUSH FRNTL BOUNDARY OFF THE NEW ENGLAND COAST...LEAVING THE CWA WITH A GRADUAL CLRING TREND THRU THE DAY AS SFC HIGH PRESSURE BUILDS EAST OUT OF THE GREAT LKS REGION. OVER PAST SEVERAL MDL RUNS...UPPER TROUGH ASSOCIATED W/ THIS SFC FRNT CONTINUES TO SLOWLY PUSH EAST THRU SOUTHERN PORTIONS OF QUEBEC INTO THE CANADIAN MARITIMES BY TUESDAY. AS A RESULT WILL CONTINUE TO MENTION SL CHANCE FOR -RW FOR NE VT THRU EARLY TUESDAY MORNING BFR CLRING OUT. OVERALL TREND IS FOR NICE WX AS SFC RIDGE REMAINS IN PLACE. STAYING CLOSE TO MDL GUIDANCE FOR TEMPS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 450 AM EDT SUNDAY...ECMWF AND GFS MODELS SHOW A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT AND WILL REMAIN OVER THE REGION THROUGH EARLY THURSDAY...WITH FAIR AND DRY WEATHER EXPECTED. ECMWF AND GFS MODELS SHOW AN UPPER TROUGH OVER THE WESTERN GREAT LAKES EARLY THURSDAY. THIS UPPER TROUGH WILL BRING MOISTURE NORTHEAST FROM THE OHIO VALLEY INTO THE REGION ON THURSDAY AS A STATIONARY FRONTAL BOUNDARY SETS UP ACROSS THE REGION. ECMWF AND GFS MODELS IN GOOD AGREEMENT IN BRINGING RAIN SHOWERS TO THE REGION THURSDAY AND FRIDAY. ECMWF AND GFS MODELS DIFFER ON THE SATURDAY FORECAST WITH THE ECMWF MODEL SHOWING AN UPPER RIDGE BUILDING INTO THE REGION ON SATURDAY...AND ALSO BRINGING A DRIER FORECAST TO THE REGION FOR SATURDAY. GFS MODEL STILL HAS AN UPPER TROUGH OVER THE REGION ON SATURDAY WITH A CHANCE OF RAIN SHOWERS. GIVEN MODEL DIFFERENCES...WILL OPT TO STAY WITH PREVIOUS CONTINUITY AND KEEP A CHANCE OF RAIN SHOWERS OVER THE REGION ON SATURDAY. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... THROUGH 18Z MONDAY...AREAS OF MVFR/IFR EXPECTED IN SHOWERS AND THUNDERSTORMS THROUGH 00Z MONDAY. SOME THUNDERSTORMS THIS AFTERNOON MAY BECOME SEVERE WITH GUSTY WINDS AND HAIL POSSIBLE. SHOWERS AND THUNDERSTORMS WILL BE MOST WIDESPREAD ACROSS VERMONT...AFFECTING TAF SITES RUT/MPV/BTV. BEST CHANCE FOR SEEING STRONG WIND GUSTS WILL BE AT RUT/MPV. ACROSS NORTHERN NEW YORK...ACTIVITY WILL BE MORE SCATTERED...AND NOT AS STRONG AS STORMS IN VERMONT. THREAT OF SHOWERS AND STORMS WILL END FROM WEST TO EAST LATER THIS AFTERNOON AND EVENING AS DRY SLOT MOVES INTO THE REGION. EXPECT MAINLY DRY CONDITIONS AFTER 22Z ACROSS NORTHERN NEW YORK AND CHAMPLAIN VALLEY...BUT NOT UNTIL 02Z MONDAY IN EASTERN VERMONT. THERE IS POTENTIAL FOR SOME MVFR OVERNIGHT IN FOG...MAINLY AT MPV/SLK/RUT...OTHERWISE VFR CONDITIONS EXPECTED FOR OVERNIGHT TONIGHT THROUGH 18Z MONDAY WITH BKN VFR CIGS. WINDS SOUTHWEST 10-20 KNOTS THIS AFTERNOON...BECOMING LIGHT SOUTHWESTERLY TONIGHT...THEN WEST 5-15 KNOTS MONDAY. STRONG WIND IN EXCESS OF 40 KNOTS POSSIBLE IN VICINITY OF THUNDERSTORMS THIS AFTERNOON. OUTLOOK 18Z MONDAY THROUGH FRIDAY... 18Z MONDAY THROUGH FRIDAY...MAINLY VFR CONDITIONS EXPECTED INTO THURSDAY. INCREASING CHANCES FOR SHOWERS LATER THURSDAY INTO FRIDAY WITH PSBL MVFR CONDITIONS. && .HYDROLOGY... SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON WITH POTENTIAL FOR LOCALIZED HEAVY RAINFALL. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING 1 TO 2 INCHES OF RAIN IN A SHORT PERIOD OF TIME...WHICH MAY CAUSE ISOLATED FLASH FLOODING...ESPECIALLY IN THE TRRN. ALSO...MINOR URBAN AND LOW LYING FLOODING WILL BE POSSIBLE...WITH THESE THUNDERSTORMS. INDIVIDUAL THUNDERSTORMS WILL MOVE FROM SOUTHWEST TO NORTHEAST AT 20 TO 30 MPH...WITH THE ENITRE BROKEN LINE SLOWLY MOVING EAST AT 10 TO 15 MPH. && .MARINE... A LAKE WIND ADVISORY CONTINUES FOR TODAY...EXPECT SOUTH WINDS TO INCREASE AT 15 TO 25 KNOTS WITH WAVES 1 TO 3 FEET. IN ADDITION...LAKE THUNDERSTORM ADVISORY CONTINUES WITH THE EXPECTATION THUNDERSTORMS WILL DEVELOP OVER THE CHAMPLAIN VALLEY AND OPEN WATERS BY EARLY THIS AFTERNOON. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JN NEAR TERM...TABER SHORT TERM...JN LONG TERM...WGH AVIATION...RJS HYDROLOGY... MARINE...
AREA FORECAST DISCUSSION
NWS BUFFALO NY
143 PM EDT SUN JUN 2 2013 .SYNOPSIS... STEADIER RAIN WILL TAPER OFF THIS AFTERNOON...THEN END TONIGHT AS NOTICEABLY COOLER AND LESS HUMID AIR SPREADS EAST ACROSS WESTERN AND CENTRAL NEW YORK. THE COOLER AND DRIER CONDITIONS WILL LAST THROUGH THE FIRST HALF OF THE NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THROUGH EARLY AFTERNOON...THE STEADIEST SHOWERS AND THUNDERSTORMS HAVE EXITED TO THE EAST. BEHIND THIS IS SLIGHTLY DRIER AIR...WITH RADAR SHOWING SCATTERED INSTABILITY SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS INTERIOR SECTIONS. FOLLOWING THE HRRR AND OTHER HIGH RESOLUTION GUIDANCE...THESE WILL PROBABLY EXPAND IN AREAL COVERAGE THROUGH LATE AFTERNOON...THEN DIMINISH TOWARD SUNSET. MEANWHILE...THE BRISK SW FLOW IS SHADOWING THE NIAGARA FRONTIER FROM BUFFALO TO ROCHESTER...WITH THIS LIKELY TO SPREAD NE TO WATERTOWN THROUGH MID-AFTERNOON. IN THESE AREAS...EXPECT WIND GUSTS TO 40 MPH FOR DURING THE AFTERNOON HOURS. MEANWHILE...THE COLD FRONTAL BOUNDARY IS STILL TO THE NORTH OF LAKE ONTARIO...WITH SHOWERS AND A FEW THUNDERSTORMS ALONG THIS BOUNDARY. THE FRONT WILL DROP TO THE SOUTH...REACHING THE SOUTH SHORES OF LAKE ONTARIO JUST SHY OF SUNSET. EXPECT SHOWERS TO WEAKEN WITH LAKE SHADOWING AND THE LOSS OF DAYTIME HEATING...BUT THERE STILL IS A CHANCE OF A SHOWER ACROSS THE NIAGARA FRONTIER EARLY THIS EVENING. THE FRONT WILL CONTINUE TO DROP SOUTHWARD OVERNIGHT...BUT PROBABLY WILL BE DRY WITH ITS MAIN INFLUENCE BEING A WIND SHIFT TO THE NW AND NOTABLY COOLER TEMPERATURES. THE RESULT WILL BE A NOTICEABLE COOLER NIGHT...WITH TEMPERATURES DOWN INTO THE 40S BY DAYBREAK. EXPECT A GRADUAL CLEARING TREND TONIGHT...WITH CLOUDS LINGERING LONGEST ACROSS THE SOUTHERN TIER AND EAST OF LAKE ONTARIO. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... BEAUTIFUL WEATHER CAN BE EXPECTED ACROSS WESTERN AND NORTH CENTRAL NEW YORK DURING THE BULK OF THIS PERIOD...AS WE WILL EXPERIENCE A STRETCH OF SUNNY COMFORTABLE DAYS WITH LOW HUMIDITY. THIS SHOULD ENABLE THE REGION AN EXCELLENT OPPORTUNITY TO DRY OUT AFTER SOAKING RAINS FROM THE WEEKEND. THE BERMUDA HIGH THAT BROUGHT US A LITTLE SUMMER HEAT AND HUMIDITY HAS LONG SINCE BROKEN DOWN AND WILL NOW BE REPLACED DURING THE FIRST HALF OF THIS WEEK BY EXPANSIVE CANADIAN HIGH PRESSURE. THIS WILL INITIALLY RESULT IN SEASONABLY COOL WEATHER WITH DAYTIME HIGHS IN THE MID 60S MONDAY AND 65 TO 70 ON TUESDAY...BUT TEMPERATURES WILL SLOWLY PUSH BACK TO NORMAL LEVELS AS WE GET INTO THE MIDDLE OF THE WEEK. MEANWHILE...WE CAN ANTICIPATE A COUPLE OF CHILLY NIGHTS WITH LOWS THROUGH WEDNESDAY MORNING IN THE 40S. AS WE HEAD INTO WEDNESDAY NIGHT THOUGH...A SHORTWAVE DROPPING ACROSS THE UPPER MID WEST WILL ESTABLISH AN INVERTED TROUGH OVER OUR WESTERN COUNTIES. THE CONVERGENCE ASSOCIATED WITH THIS LOW LEVEL FEATURE COULD THEN PRODUCE SOME SHOWERS FROM THE FINGER LAKES WESTWARD AS THE NIGHT PROGRESSES. && .LONG TERM /THURSDAY THROUGH SATURDAY/... CONDITIONS WILL GENERALLY BE UNSETTLED DURING THIS PERIOD... ESPECIALLY THURSDAY AND FRIDAY WHEN AN INVERTED TROUGH WILL SLOWLY CROSS OUR REGION. THIS WILL RESULT IN SCATTERED SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO...BUT THE DYNAMICS AND INSTABILITY SHOULD BE LACKING FOR ANY SIGNIFICANT CONVECTION. AS WE START NEXT WEEKEND...THE ECMWF IS SUGGESTING THAT MID LEVEL RIDGING WILL BUILD BACK ACROSS THE LOWER GREAT LAKES AND RE-ESTABLISH DRY WEATHER FOR AT LETS A PORTION OF OUR FORECAST AREA. TEMPERATURES DURING THIS PERIOD WILL CLOSE TO...OR JUST A BIT ABOVE NORMAL WITH HIGHS GENERALLY IN THE MID 70S AND LOWS IN THE MID TO UPPER 50S. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... THE BACK EDGE OF THE STEADIER RAIN HAS MOVED WELL EAST OF THE REGION. THERE WILL BE SCATTERED DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS THIS AFTERNOON...BUT THESE ARE UNLIKELY TO IMPACT TAF LOCATIONS...WITH MOST OF THIS ACTIVITY FORECAST TO BE ACROSS INTERIOR SECTIONS. OTHERWISE...THE MAIN IMPACT DURING THIS TIME WILL BE GUSTY SW WINDS TO ABOUT 30 KTS AT MOST SITES. A COLD FRONT WILL DROP SOUTHWARD ACROSS THE REGION ROUGHLY AROUND 00Z. THIS MAY SPARK A SHOWER...AND WILL KEY A WIND SHIFT TO THE W-NW. A BRIEF PERIOD OF MVFR CIGS ARE POSSIBLE BEHIND THE FRONT...WITH CIGS LIKELY TO LIFT AND SCATTER DURING THE DAY ON MONDAY. LEFT OVER MOISTURE MAY RESULT IN BRIEF BKN MVFR CIGS...BUT THESE WOULD BE VERY SHORT LIVED AS DRIER AIR MIXES IN. OUTLOOK... MONDAY THROUGH WEDNESDAY...VFR. THURSDAY...MAINLY VFR. A CHANCE OF THUNDERSTORMS. && .MARINE... AN AREA OF LOW PRESSURE WILL TRACK NORTH OF LAKE ONTARIO TODAY AND DRAG A COLD FRONT EAST ACROSS THE LAKE THIS AFTERNOON. MODEST SOUTHWEST WINDS AHEAD OF THE FRONT WILL RESULT IN SCA CONDITIONS LATER THIS MORNING THROUGH THE AFTERNOON. && .HYDROLOGY... SEVERAL OF THE BUFFALO CREEKS WILL RUN HIGH TODAY...DUE TO THE TWO INCHES OF RAIN THAT FELL OVER THE LAST 24 HOURS. NONE OF THESE ARE EXPECTED TO REACH FLOOD STAGE...BUT THE CAYUGA CREEK IN LANCASTER AND THE CAZENOVIA CREEK IN EBENEZER ARE BOTH CRESTING LATE THIS MORNING NEAR OR JUST ABOVE ACTION STAGE. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LEZ040- 041. SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LEZ020. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LOZ042>044. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SLZ022-024. && $$ SYNOPSIS...APFFEL NEAR TERM...APFFEL/TJP SHORT TERM...WCH LONG TERM...RSH AVIATION...APFFEL/RSH MARINE...APFFEL/RSH/TJP HYDROLOGY...APFFEL
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
123 PM EDT SUN JUN 2 2013 .SYNOPSIS... A COLD FRONT WILL PRODUCE NUMEROUS SHOWERS AND THUNDERSTORMS TODAY ACROSS THE NORTH COUNTRY. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCE STRONG AND DAMAGING WINDS...SMALL HAIL...AND LOCALIZED HEAVY DOWNPOURS. CLEARING AND COOLER TEMPERATURES WILL ARRIVE BY THE START OF THE WORK WEEK. && .NEAR TERM /UNTIL 11 PM THIS EVENING/... AS OF 117 PM EDT SUNDAY...QUICK UPDATE TO FCST FOR CRNT OBS AND ADJUSTED TEMPS UP SEVERAL DEGREES. CRNT RADAR SHOWS SHOWERS/STORMS DEVELOPING ACRS ESSEX COUNTY NY AND THE NORTHERN HUDSON VALLEY REGION...WITH CRNT MOTION TO THE NE AT 25 TO 35 MPH. LATEST LAPS DATA CONTS TO SHOW SFC BASED CAPE VALUES BTWN 1500 AND 2500 J/KG...ACRS CPV AND POINTS EAST. IN ADDITION...BEST DYNAMICS AND LLVL WIND FIELDS ARE APPROACHING OUR WESTERN CWA ATTM. EXPECT AREAL COVERAGE/INTENSITY OF SHOWERS/STORMS TO INCREASE ACRS MOST OF CENTRAL/SOUTHERN VT THIS AFTN. MAIN THREAT WL BE STRONG/DAMAGING WINDS THRU EARLY THIS EVENING. GIVEN CRNT TRENDS...GREATEST THREAT FOR HEAVY RAIN AND POTENTIAL ISOLATED FLASH FLOODING WL BE ACRS THE ESSEX COUNTY NY INTO PARTS OF CENTRAL/SOUTHERN VT. WE WL BE WATCHING THIS POTENTIAL CLOSELY AS WE PROGRESS THRU THE AFTN/EVENING HOURS. REST OF FCST IN GOOD SHAPE. UPDATED ZNS TO REFLECT SVR THUNDERSTORM WATCH #271 FOR EASTERN DACKS THRU VT UNTIL 8 PM THIS EVENING. REST OF FCST IN GREAT SHAPE. UPDATED FCST TO MENTION SHOWERS/STORMS THRU THIS MORNING FOR CENTRAL/NORTHERN VT AND REMOVED MENTION OF ENHANCED WORDING THRU THE MORNING HOURS. ALSO...ADJUSTED TEMPS/DWPTS BASED ON CRNT OBS. FCST CHALLENGE IS TIMING OF CONVECTION TODAY...FOLLOWED BY AREAL COVERAGE/INTENSITY OF STORMS THIS AFTN. WATER VAPOR SHOWS POTENT S/W ENERGY ACRS THE EASTERN GREAT LAKES...WITH ENHANCED RIBBON OF DEEP LAYER MOISTURE AHEAD OF THIS ENERGY ACRS WESTERN NY/PA. IN ADDITION...STRONG HGHT FALLS ARE OCCURRING AS MID/UPPER LVL TROF LIFTS TWD HUDSON`S BAY THIS AFTN AND ASSOCIATED SFC BOUNDARY SWINGS ACRS OUR CWA. AT THE SFC...INITIAL PRE-FRNTAL TROF HAS PRODUCED SHOWERS WITH A FEW EMBEDDED RUMBLES OF THUNDER ACRS THE EASTERN DACKS INTO NORTHERN/CENTRAL VT THIS MORNING. EXPECT SOME CLRING BEHIND THIS INITIAL TROF...WHICH WL AID SFC HEATING. WITH TEMPS WARMING TO NEAR 80F...AND DWPTS IN THE U60S TO L70S...SFC BASED CAPE VALUES WL BE BTWN 2000-2500 J/KG...ESPECIALLY ALONG AND EAST OF THE CPV. EXPECT ANOTHER ROUND OF STORMS TO REDEVELOP BY EARLY THIS AFTN ACRS THE EASTERN DACKS...AND BECOME SEVERE AS THEY ENCOUNTER BETTER INSTABILITY/SHEAR ACRS THE CPV AND MOST OF VT. SOUNDINGS SHOW A MAINLY UNIDIRECTIONAL WIND FLW THRU 500MB...SUPPORTING LINES OF STORMS WITH INDIVIDUAL BOW SEGMENTS POSSIBLE...WITH PRIMARY THREAT BEING STRONG/DAMAGING WINDS. PRE-STORM CHECKLIST SHOWS VERY HIGH 0C LINE AROUND 13KFT THIS AFTN...WHICH INDICATES WE WOULD NEED A 50 TO 55 DBZ TO 35,000 FEET FOR SEVERE HAIL. THEREFORE PRIMARY THREAT WL BE WINDS...AND GIVEN RECENT SATURATED SOILS...SHALLOW ROOTED TREES COULD EASILY BE BLOWN DOWN. STORMS SHOULD CLEAR EASTERN VT BY 8 PM THIS EVENING...BASED ON CRNT RAP AND BTV 4KM REFLECTIVITY PROGS. PREVIOUS DISCUSSION...ACTIVE 24-HR PERIOD EXPECTED FOR TODAY/ TONIGHT AS A CD FRNT WILL BEGIN TO PUSH THRU THE AREA. RW/TRW FROM THE OVERNGT PERIOD STILL SLOWLY PUSHING NORTH THRU CANADIAN BORDER ZONES ATTM AND SHOULD CLR INTO QUEBEC BFR MAIN PRECIP ARRIVES WITH FRNT...WHICH IS ONLY TO OUR WEST OVER WESTERN NY/LK ONTARIO. MANY SPOTS IN THE CWA WILL SEE INSTABILITY INCR DURING THE DAY AS PSUNNY/MSUNNY WILL ENSUE BFR CONVECTION BEGINS TO DEVELOP...ALLOWING FOR INCR IN T/TD THROUGHOUT AREA. THIS COMBINED WITH STRONG SHEAR/LAPSE RATES...LI/S NEARING -4 AND MDL CAPE FROM BUFKIT SHOWING 1500-2000 J/KG POTENTIAL...WILL ALLOW FOR DEVELOPMENT OF STRONG TO SEVERE STORMS FOR TODAY/TNGT. SPC(STORM PREDICTION CENTER) HAS MAJORITY OF CWA UNDER SL RISK FOR SEVERE CONDITIONS SO HAVE MAINTAINED SEVERE/ENHANCED WORDING IN FORECAST. MDL PW/S NEARING 1.25-1.60" IN GENERAL WITH LOCALLY HIR AMTS WILL CREATE QPF AMTS IN GENERAL NEARLY AN INCH FOR ALL AREAS...W/ LOCALLY HIR TOTALS IN HEAVIER DOWNPOURS. W/ SOME AREAS SEEING TRAINING OF RW/TRW OVERNGT...HYDRO CONCERNS WILL BE AN ISSUE TO MONITOR. LATEST MDL TREND IS TO BRING BULK OF PRECIP THRU AREA AFTER MIDNGT TONIGHT. MID-LEVEL DRY AIR WORKING AROUND LOW TO OUR WEST MAY AID IN SHUTTING DOWN PRECIP QUICKER. FOR NOW WILL KEEP PRECIP TRENDING DOWN THRU 12Z MONDAY AS TRAINING POTENTIAL MAY KEEP PRECIP GOING ALONG FRNT A BIT LONGER. TEMP THRU PERIOD NEAR GUIDANCE...ESPECIALLY EASTERN ZONES WHERE NOT AFFECTED BY CLD COVER FROM APPORACHING FRNT. && .SHORT TERM /11 PM THIS EVENING THROUGH TUESDAY/... AS OF 424 AM EDT SUNDAY...GOING INTO MONDAY MORNING...MDLS PUSH FRNTL BOUNDARY OFF THE NEW ENGLAND COAST...LEAVING THE CWA WITH A GRADUAL CLRING TREND THRU THE DAY AS SFC HIGH PRESSURE BUILDS EAST OUT OF THE GREAT LKS REGION. OVER PAST SEVERAL MDL RUNS...UPPER TROUGH ASSOCIATED W/ THIS SFC FRNT CONTINUES TO SLOWLY PUSH EAST THRU SOUTHERN PORTIONS OF QUEBEC INTO THE CANADIAN MARITIMES BY TUESDAY. AS A RESULT WILL CONTINUE TO MENTION SL CHANCE FOR -RW FOR NE VT THRU EARLY TUESDAY MORNING BFR CLRING OUT. OVERALL TREND IS FOR NICE WX AS SFC RIDGE REMAINS IN PLACE. STAYING CLOSE TO MDL GUIDANCE FOR TEMPS. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 450 AM EDT SUNDAY...ECMWF AND GFS MODELS SHOW A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT AND WILL REMAIN OVER THE REGION THROUGH EARLY THURSDAY...WITH FAIR AND DRY WEATHER EXPECTED. ECMWF AND GFS MODELS SHOW AN UPPER TROUGH OVER THE WESTERN GREAT LAKES EARLY THURSDAY. THIS UPPER TROUGH WILL BRING MOISTURE NORTHEAST FROM THE OHIO VALLEY INTO THE REGION ON THURSDAY AS A STATIONARY FRONTAL BOUNDARY SETS UP ACROSS THE REGION. ECMWF AND GFS MODELS IN GOOD AGREEMENT IN BRINGING RAIN SHOWERS TO THE REGION THURSDAY AND FRIDAY. ECMWF AND GFS MODELS DIFFER ON THE SATURDAY FORECAST WITH THE ECMWF MODEL SHOWING AN UPPER RIDGE BUILDING INTO THE REGION ON SATURDAY...AND ALSO BRINGING A DRIER FORECAST TO THE REGION FOR SATURDAY. GFS MODEL STILL HAS AN UPPER TROUGH OVER THE REGION ON SATURDAY WITH A CHANCE OF RAIN SHOWERS. GIVEN MODEL DIFFERENCES...WILL OPT TO STAY WITH PREVIOUS CONTINUITY AND KEEP A CHANCE OF RAIN SHOWERS OVER THE REGION ON SATURDAY. && .AVIATION /17Z SUNDAY THROUGH FRIDAY/... THROUGH 12Z MONDAY...AREAS OF MVFR/IFR EXPECTED IN SHOWERS AND THUNDERSTORMS THROUGH 00Z MONDAY. SOME THUNDERSTORMS TODAY MAY BECOME SEVERE WITH GUSTY WINDS AND HAIL POSSIBLE. COMPOSITE RADAR LOOP AS OF 1130Z SUNDAY SHOWING SOME SHOWERS WITH SOME EMBEDDED THUNDERSTORMS ACROSS THE SAINT LAWRENCE VALLEY IN NORTHERN NEW YORK AT THIS TIME. EXPECTING STRONG TO POSSIBLE SEVERE THUNDERSTORMS TO DEVELOP ACROSS THE SAINT LAWRENCE VALLEY IN NORTHERN NEW YORK AROUND 14Z-18Z TODAY...AND THEN SHIFT EASTWARD. EXPECTING SHOWER AND THUNDERSTORM ACTIVITY COMING TO AN END IN THE SAINT LAWRENCE VALLEY IN NORTHERN NEW YORK BY 18Z SUNDAY. EXPECTING WIDESPREAD STRONG TO SEVERE THUNDERSTORMS TO DEVELOP ACROSS THE REMAINDER OF THE REGION FROM 16Z-21Z SUNDAY. A MID LEVEL DRY SLOT WILL MOVE INTO THE REGION LATE THIS AFTERNOON...SO EXPECTING ANY THUNDERSTORM ACTIVITY TO BE CONFINED TO EASTERN AND SOUTHERN VERMONT BY 00Z MONDAY. EXPECTING ANY THUNDERSTORM ACTIVITY WILL BE EAST OF THE REGION BY 03Z MONDAY. OUTLOOK 12Z MONDAY THROUGH THURSDAY... 12Z MONDAY THROUGH THURSDAY...MAINLY VFR CONDITIONS EXPECTED THROUGH THURSDAY. && .HYDROLOGY... SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON WITH POTENTIAL FOR LOCALIZED HEAVY RAINFALL. THE STRONGER STORMS WILL BE CAPABLE OF PRODUCING 1 TO 2 INCHES OF RAIN IN A SHORT PERIOD OF TIME...WHICH MAY CAUSE ISOLATED FLASH FLOODING...ESPECIALLY IN THE TRRN. ALSO...MINOR URBAN AND LOW LYING FLOODING WILL BE POSSIBLE...WITH THESE THUNDERSTORMS. INDIVIDUAL THUNDERSTORMS WILL MOVE FROM SOUTHWEST TO NORTHEAST AT 20 TO 30 MPH...WITH THE ENITRE BROKEN LINE SLOWLY MOVING EAST AT 10 TO 15 MPH. && .MARINE... A LAKE WIND ADVISORY CONTINUES FOR TODAY...EXPECT SOUTH WINDS TO INCREASE AT 15 TO 25 KNOTS WITH WAVES 1 TO 3 FEET. IN ADDITION...LAKE THUNDERSTORM ADVISORY CONTINUES WITH THE EXPECTATION THUNDERSTORMS WILL DEVELOP OVER THE CHAMPLAIN VALLEY AND OPEN WATERS BY EARLY THIS AFTERNOON. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...JN NEAR TERM...TABER SHORT TERM...JN LONG TERM...WGH AVIATION...WGH/RJS HYDROLOGY... MARINE...
AREA FORECAST DISCUSSION...UPDATED AVIATION DISCUSSION
NWS PENDLETON OR
1020 AM PDT SUN JUN 2 2013 .UPDATE...MINOR UPDATES WERE MADE TO THE CURRENT FORECAST. A LARGE UPPER LEVEL TROUGH OVER WA/ID/MT WILL PUSH AN EMBEDDED WAVE OVER SE WASHINGTON AND NE OREGON THIS AFTERNOON. THERE IS LIMITED MOISTURE WITH THE APPROACHING DISTURBANCE...BUT A 100 KNOT JET ALONG THE BOTTOM OF THE TROUGH WILL RESULT IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM THE TRI-CITIES, PENDLETON, AND UKIAH EAST TO THE IDAHO BORDER. BASED UPON THE HRRR COMPOSITE REFLECTIVITY SHOWING CONVECTIVE CELLS ACROSS THE WASHINGTON COLUMBIA BASIN...THE FORECAST WAS UPDATED TO EXTEND ISOLATED THUNDERSTORMS FARTHER WEST TO INCLUDE THE EASTERN PORTION OF THE LOWER COLUMBIA BASIN. THERE MAY BE A FEW STRONG THUNDERSTORMS TODAY WITH DIME TO PENNY-SIZE HAIL...BUT SEVERE STORMS ARE NOT EXPECTED. A FAIRLY TIGHT SURFACE PRESSURE GRADIENT AND A WEAK MARINE PUSH WILL RESULT IN 20-30 MPH WINDS THROUGH THE EASTERN SIDE OF THE COLUMBIA RIVER GORGE AND THE KITTITAS VALLEY. THE SYSTEM WILL HAVE VERY LITTLE IMPACT IN OUR SOUTHERN ZONES...THEREFORE IT WILL BE MOSTLY SUNNY AND A LITTLE BREEZY ACROSS CENTRAL OREGON TODAY. THE SYSTEM WILL EXIT THE REGION THIS EVENING WITH MOST SHOWERS ENDING BY MIDNIGHT. WISTER AVIATION...18Z TAFS...VFR CONDITIONS TO PREVAIL OVER THE NEXT 24 HOURS. THERE WILL BE SOME CUMULUS BUILDUPS WITH A SLIGHT CHANCE OF A THUNDERSTORM EAST OF A LINE FROM KPSC TO KPDT THROUGH 06Z. CLOUDS WILL BE AT 5-8 THOUSAND FEET. WINDS WILL BE 10-20 KT FROM THE NW WITH A FEW HIGHER GUSTS. WINDS AND CLOUD COVER WILL DIMINISH AFTER 06Z TONIGHT. ML && .PREV DISCUSSION... /ISSUED 431 AM PDT SUN JUN 2 2013/ LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...HIGH PRESSURE WILL BUILD OVER THE AREA FOR THE EXTENDED. EXPECT MOSTLY DRY CONDITIONS AND TEMPERATURES TO INCREASE THROUGH THE WORK WEEK...INTO THE WEEKEND. EXPECT TEMPERATURES TO BE IN THE MID 80S TO LOWER 90S ACROSS THE LOWER ELEVATIONS...WITH 70S TO LOWER 80S MOUNTAINS. MODELS DO INDICATE A FEW WEAK DISTURBANCES THAT MAY PASS IN THE EXTENDED...BUT ONLY ANTICIPATE OCCASIONAL BREEZY CONDITIONS AND BRIEF INCREASED CLOUD COVER TO BE ASSOCIATED. WEBER && .PRELIMINARY POINT TEMPS/POPS... PDT 73 48 75 50 / 10 10 0 0 ALW 74 53 77 55 / 20 20 0 0 PSC 79 51 80 53 / 10 10 0 0 YKM 78 47 79 49 / 10 10 0 0 HRI 77 50 79 52 / 10 10 0 0 ELN 74 48 79 50 / 10 10 0 0 RDM 72 37 77 39 / 10 10 0 0 LGD 69 44 72 46 / 20 20 10 10 GCD 67 43 70 45 / 10 10 0 0 DLS 77 52 80 54 / 10 10 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && THREAT INDEX TODAY : GREEN MONDAY : GREEN TUESDAY : GREEN GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES. YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 85/93
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1251 PM CDT SUN JUN 2 2013 .DISCUSSION... 18Z AVIATION DISCUSSION BELOW. && .AVIATION... RAIN SHIELD IS SHRINKING ACROSS THE SOUTHWESTERN FORECAST AREA... LINGERING -RA OVER KLBX`S VICINITY. VFR WITH LIGHT NORTH/VRB BREEZES THROUGH THE PERIOD...THE HIGH CLOUD DECK BREAKING UP TO MAINLY SKY CLEAR BY THIS EVENING. CLEAR AND CALM EARLY MORNING CONDITIONS...WITH A DAMP GROUND...WILL PROVIDE AN ENVIRONMENT CONDUCIVE TO THE FORMATION OF SHORT-LIVED SHALLOW RADIATIVE FOG. 31 && .PREV DISCUSSION... /ISSUED 1053 AM CDT SUN JUN 2 2013/ UPDATE... SEE MORNING UPDATE. DISCUSSION... RAIN HAS PUSHED TO THE COAST AND WILL CONTINUE TO PUSH AWAY FROM SE TX. A WEAK COLD FRONT EXTENDED FROM EL DORADO ARKANSAS TO GALVESTON AND THEN WEST TOWARD COTULLA. DRIER AIR HAS BEGUN TO FILTER INTO SE TX WITH SFC DEW PTS NOW IN THE MID/UPPER 60S. CONSIDERABLE CLOUD COVER AND WET GROUND WILL LIKELY LIMIT HEATING TODAY SO HAVE TRIMMED MAX TEMPS A FEW DEGREES. CLOUDS SHOULD BEGIN TO ERODE IN THE NEXT HOUR OR SO AND PLENTY OF SUNSHINE IS STILL EXPECTED BY LATE AFTERNOON. RAP MODEL SHOWS SOME REDVELOPMENT ALONG THE COAST LATE THIS AFTERNOON AND WILL LEAVE 20 POPS IN TO ACCOUNT FOR THE POSSIBILITY. NEW ZONES OUT BY 11 AM. 43 PREV DISCUSSION... /ISSUED 655 AM CDT SUN JUN 2 2013/ DISCUSSION... 12Z AVIATION DISCUSSION. AVIATION... A LINE OF STRONG TO SEVERE THUNDERSTORMS WILL MOVE THROUGH THE HOUSTON METRO AREA BETWEEN 12 AND 16Z THIS MORNING...AND OFF THE COAST BETWEEN 14 AND 18Z. WINDS MAY BRIEFLY GUST FROM THE NORTH AT 25 TO 25 KNOTS WITH VISIBILITIES DROPPING TO 1 MILE IN HEAVY RAIN. CONDITIONS SHOULD GRADUALLY IMPROVE BEHIND THE LINE WITH ALL TERMINALS VFR BY THIS AFTERNOON. SKIES SHOULD CLEAR OUT OVERNIGHT WITH LIGHT NORTHERLY WINDS. 44 PREV DISCUSSION... /ISSUED 445 AM CDT SUN JUN 2 2013/ DISCUSSION... A LINE OF THUNDERSTORMS IS BEGINNING TO FILL IN FROM SOUTH OF LUFKIN TO COLLEGE STATION. RAIN GAUGES IN TRINITY COUNTY ARE PICKING UP AS MUCH AS 2.2 INCHES IN 3 HRS AND AS MUCH AS 2 INCHES OF THAT HAS FALLEN IN THE LAST HOUR. ALSO SEEING A SIGNS OF A REAR INFLOW JET DEVELOPING IN THE BACK SIDE OF CONVECTION CLOSING IN ON BRYAN/COLLEGE STATION. BASED ON IR IMAGERY SEEMS CLOUD TOPS ARE COOLING MORE SO EXPECT DEEP CONVECTION TO CONTINUE THROUGH THE MORNING. THE MAIN THREAT WILL BE HEAVY RAINFALL ON THE ORDER OF 2 TO 3 INCHES AN HOUR LIKE ALREADY OBSERVED. STORM MOTIONS ARE EXPECTED TO BE SLOW AS IN 10 TO 2O MPH BUT COULD SEE CELLS CONTINUE TO DEVELOP ALONG A FRONT PUSHING INTO THE AREA WHICH COULD TRAIN ACROSS AREAS THAT HAVE ALREADY RECEIVED RAINFALL. SFC ANALYSIS AT 09Z SHOWS FRONTAL BOUNDARY SLOWLY PUSHING SOUTH FROM THE ARLATEX THROUGH C TX INTO THE NW HILL COUNTRY. LOOK FOR CURRENT CONVECTION TO SLOWLY WORK SOUTH AHEAD OF THE FRONT AND POSSIBLY OUT RUN IT BY A GOOD BIT. THE 00Z HIRES-WRF-ARW/TXTECH WRF AND HRRR ALL SHOW CURRENT LINE OF CONVECTION WORKING SOUTH THROUGH SE TX IN A BROKEN LINE. THE LINE THEN WEAKENS AS IT APPROACHES THE COAST BETWEEN 15Z-18Z. DECIDED TO KEEP SOME 50/60 POPS THROUGH 12-15Z AND THEN GRADUALLY DECREASE RAIN CHANCES. LOOKS LIKE THIS PART OF THE FORECAST MAY GO THROUGH ADDITIONAL MODIFICATIONS DEPENDING ON HOW THE CONVECTION EVOLVES THIS MORNING. DO THINK THIS CONVECTION SHOULD WORK OVER AND STABILIZE THE ATMOSPHERE FOR THE AFTERNOON SO 20 POPS FOR THE AFTERNOON LOOKS GOOD BUT IT COULD BE DRY. AS IT HAS BEEN DISCUSSED BEFORE...MAIN HAZARD THIS MORNING WILL BE HEAVY RAINFALL. UPPER LEVEL ANALYSIS SHOWS A TROUGH AXIS WORKING THROUGH THE AREA AND THERE MAY BE ENOUGH UPPER LEVEL SUPPORT TO KEEP CONVECTION GOING THIS MORNING. EXPECT UPPER LEVEL ASCENT TO WEAKEN DURING THE AFTERNOON AND CONVERGENCE ALONG THE FRONT TO WEAKEN AS WELL. THUS BEST CHANCES FOR HEAVY RAIN STILL THIS MORNING AND THREAT DIMINISHING IN THE AFTERNOON. PRECIP WATER VALUES THIS MORNING PEAK INVOF CONVECTION AROUND 1.8-2.0 INCHES AND DECREASE THIS AFTERNOON TO BELOW 1.5 INCHES. AS FOR THE REST OF THE FORECAST...MODELS STILL BRING WEAK FRONT TO THE COAST AND POSSIBLY OFF THE COAST. EXPECT SFC DEWPOINT TEMPS TO DROP INTO THE LOW 60S WHICH WILL SEEM QUITE A BIT DRIER THAN THE MID 70S DEWPOINTS OF LATE. THIS ALSO MEANS SEASONABLE MIN TEMPS IN THE MID 60S FOR MON/TUE. EXPECT DRY CONDITIONS TO PERSIST AS UPPER LEVEL RIDGING BUILDS OVER S TX THROUGH MID WEEK. RIDGE DOES SHOW SIGNS OF BREAKING DOWN AGAIN FOR THE END OF THE WEEK WITH AN UPPER LOW OVER THE N PLAINS/MIDWEST/GREAT LAKES. THIS INTRODUCES NW FLOW ALOFT OVER TX FOR THE END OF THE WEEK WHICH MAY ALSO SUPPORT A WEAK FRONT MOVING INTO TX ALONG WITH A SERIES OF WEAK SHORTWAVES THAT COULD INITIATE A FEW ROUNDS OF CONVECTION ALONG THE RED RIVER AND N TX. POSSIBLE SOME OF THIS CONVECTION COULD WORK INTO SE TX. WILL KEEP 20 POPS FOR THE END OF THE WEEK WITH INCREASED MOISTURE AND FAVORABLE UPPER LEVEL PATTERN. AS WITH TROPICAL SEASON WILL KEEP AN EYE ON CONVECTION IN THE BAY OF CAMPECHE AND YUCATAN PENINSULA. BOTH GFS/ECMWF SUPPORT CONVECTION BECOMING ORGANIZED AGAIN FROM REMNANTS OF BARBARA BY TUESDAY. BOTH MODELS ALSO BRING THIS NEW SYSTEM INTO FLORIDA THUR/FRI TIME FRAME. THERE WILL BE A DECENT AMOUNT OF WIND SHEAR SO TOUGH TO KNOW HOW ORGANIZED THE SYSTEM WILL BECOME. NONETHELESS ALL INDICATIONS ARE THAT THIS WILL NOT BE A THREAT FOR THE TX COAST. 39 MARINE... LIGHT ONSHORE FLOW SHOULD BECOME LIGHT AND VARIABLE BY THIS AFTERNOON IN ADVANCE OF A WEAK COLD FRONT. LIGHT EAST TO SOUTHEAST WINDS AND 1 TO 2 FOOT SEAS WILL BE THE PREVAILING CONDITION THROUGH THE MAJORITY OF NEXT WEEK BECAUSE OF A VERY LIGHT PRESSURE GRADIENT BEHIND THE FRONT. 44 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 64 92 68 93 71 / 10 0 0 0 0 HOUSTON (IAH) 67 92 69 93 71 / 10 0 0 0 0 GALVESTON (GLS) 75 88 76 88 77 / 10 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43 AVIATION/MARINE...31