Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/12/15


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
225 PM MST SUN MAY 10 2015 .SYNOPSIS... NEAR NORMAL TEMPERATURES WITH PLENTY OF SUNSHINE CAN BE EXPECTED THROUGH THURSDAY ACROSS THE DESERT SOUTHWEST. FRIDAY THROUGH SUNDAY ...ANOTHER UNSEASONABLY COOL STORM WILL ARRIVE...USHERING IN MUCH COOLER TEMPERATURES...BREEZY CONDITIONS...AND HEIGHTENED CHANCES FOR RAIN. && .DISCUSSION... BENIGN WEATHER ACROSS OUR FORECAST AREA THIS AFTERNOON WITH NEARLY ZERO CLOUD COVER. SOME WEAK ECHOES HAVE DEVELOPED OVER THE RIM/WHITE MTNS RESULTING IN SOME THUNDER. BASED ON HRRR TRENDS/FLOW NOT EXPECTING THAT ACTIVITY TO IMPACT OUR AREA. TAKE-HOME MESSAGE AT THIS TIME IS NEAR/ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL GIVE WAY TO ANOTHER ROUND OF UNSEASONABLY COOL AND SHOWERY WEATHER BY FRIDAY THAT WILL LAST THROUGH THE WEEKEND. FIRST HALF OF THE WEEK...NOT MUCH TO DISCUSS. SHORT TERM MODELS ARE LOCKED INTO THE DEPARTING LOW AND INCOMING SHORT WAVE RIDGE YIELDING LITTLE DIFFERENCE IN FORECAST MAX/MIN TEMP VALUES. TUESDAY COULD BE A BIT INTERESTING AS A SHORT WAVE RIDES THE SOUTHERLY FLOW AND ADVECTS SOME MOISTURE INTO EASTERN ARIZONA...THOUGH POTENTIAL IMPACT TO OUR FORECAST AREA IS MINIMAL AT THIS TIME. GLOBAL ENSEMBLE DATA AND DETERMINISTIC RUNS OF EC/GFS ARE IN REALLY GOOD AGREEMENT ON THE BROAD DETAILS FOR FRIDAY THROUGH SUNDAY. ANOTHER LARGE CLOSED LOW...OF WHICH THE CURRENT ENERGY IS NEAR THE ALEUTIAN ISLANDS...WILL MOVE INTO SOCAL AND AZ FRIDAY. THERE WILL BE A LEADING SHORT WAVE WHICH WILL LIKELY GIVE US OUR BEST CHANCE OF RAIN...CURRENTLY TIMES TO ARRIVE DURING THE DAY FRIDAY. WE COULD SEE SOME ENHANCED WINDS AS THE SYSTEM LAYS INTO ARIZONA...IF HUMIDITY VALUES ARE STILL LOW WHEN THIS HAPPENS WE COULD HAVE A PERIOD OF CRITICAL FIRE WEATHER CONDITIONS. SOMETHING TO WATCH. BROAD TROUGHING WILL CONTINUE THROUGH THE WEEKEND. HARD TO SAY IF/WHEN SHOWERS WILL OCCUR AS THAT/LL HINGE ON THE FINER DETAILS OF SHORT WAVE ENERGY ROTATING AROUND THE PARENT LOW. THERE DOES SEEM TO BE QUITE HIGH CERTAINTY THAT WE/RE IN FOR ANOTHER WEEKEND IN MAY OF COOL TEMPS. CURRENT FORECAST HIGH TEMPS ON SATURDAY RANGE FROM 10 TO 20 DEGREES BELOW NORMAL. AN ANALYSIS OF HISTORICAL PHOENIX RECORDS INDICATE THAT THERE HAVE ONLY BEEN FIVE INSTANCES/YEARS WHERE THE MONTH OF MAY HAD TWO OR MORE SATURDAYS WITH A HIGH TEMP BELOW 80F /LAST WAS IN 1971/. WITH A CURRENT FORECAST HIGH OF 78 FOR THIS COMING SATURDAY...2015 WOULD BE THE SIXTH. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... DRY WESTERLY FLOW ALOFT PROVIDING CLEAR SKIES AND LIGHT WINDS THROUGH MONDAY EVENING. WIND DIRECTIONS SHOULD MOSTLY FOLLOW TYPICAL DIURNAL PATTERNS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... WEDNESDAY THROUGH SUNDAY... WARM TEMPERATURES AND LOW HUMIDITY VALUES WILL BE ESTABLISHED MID- WEEK BUT THAT WILL CHANGE BY FRIDAY AS ANOTHER UNSEASONABLY COOL STORM SYSTEM ENTERS THE SOUTHWEST. BREEZY WINDS WILL ACCOMPANY THE SYSTEM AS IT MOVES IN THURSDAY AND EARLY FRIDAY AND COULD COMBINE WITH STILL DEPRESSED HUMIDITY VALUES FOR A PERIOD OF CRITICAL FIRE WEATHER CONDITIONS. AS THE SYSTEM EASES IN LATER FRIDAY... TEMPERATURES WILL DROP AND HUMIDITY VALUES WILL INCREASE. CHANCES FOR WETTING RAIN...ESPECIALLY ACROSS CENTRAL ARIZONA...WILL ALSO INCREASE. THIS WEATHER PATTERN WILL LIKELY REMAIN THROUGH THE WEEKEND. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...INIGUEZ AVIATION...INIGUEZ FIRE WEATHER...INIGUEZ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
931 AM MST SUN MAY 10 2015 .UPDATE... LITTLE CHANGE IN THE FORECAST FOR TODAY. BROAD CYCLONIC FLOW REMAINS ACROSS THE REGION AS A LARGE CLOSED LOW MOVES OUT INTO THE PLAINS FROM THE MOUNTAIN WEST. NOTED A JET STREAK COMING DOWN THE BACK SIDE IN THIS MORNING/S RAOBS AND MODEL INITIAL FIELDS. MOISTURE IS SCANT THOUGH AND WITH MID-LEVELS ALREADY WARMING NOT EXPECTING MUCH IN WAY OF SHOWER/TSTM ACTIVITY FOR OUR AREA. CU FIELDS ARE OFF TO AN EARLY START ACROSS NORTHERN ARIZONA BUT LIMITED DEVELOPMENT AND MOVEMENT WILL PRECLUDE US FROM SEEING MUCH IF ANY ACTIVITY. HRRR RUNS SEEM DIALED INTO THAT SOLUTION. DID MAKE MODEST ADJUSTMENTS TO MAX TEMPS FOR TODAY BASED ON PAST FEW HRRR RUNS...TEMPERATURES NEAR NORMAL LOOK ON-TRACK. OVERALL A QUIET AND PLEASANT SUNDAY UNFOLDING. && .SYNOPSIS... A LOW PRESSURE SYSTEM IN THE PLAINS WILL CONTINUE TO BRING BELOW NORMAL TEMPERATURES TO THE DESERT SOUTHWEST TODAY. HIGH PRESSURE WILL THEN ALLOW TEMPERATURES TO RETURN TO NORMAL VALUES BY EARLY NEXT WEEK ALTHOUGH MID TO LATE WEEK TROUGHING ACROSS THE PACIFIC NORTHWEST SHOULD PREVENT TEMPERATURES FROM CLIMBING INTO THE TRIPLE DIGITS. THERE WILL ALSO BE AN INCREASING CHANCE OF PRECIPITATION LATE IN THE WEEK AS A TROUGH APPROACHES THE AREA. && .DISCUSSION... UPPER LEVEL LOW PRESSURE OVER COLORADO REMAINS THE DOMINANT WEATHER FEATURE ACROSS THE WESTERN CONUS...AND CONTINUES TO USHER BELOW NORMAL TEMPERATURES INTO THE REGION. LATE DAY SHOWERS AND CU ACROSS THE REGION HAVE LONG SINCE DISSIPATED...BUT ONE FINAL SHORTWAVE TROUGH WAS MAKING ITS WAY THROUGH NORTHWEST ARIZONA THIS MORNING. REGIONAL RADAR MOSAIC INDICATED VERY ISOLATED SHOWERS SOUTH OF LAS VEGAS EARLIER THIS MORNING...BUT EVEN THESE HAVE STARTED DYING OFF SINCE 08Z. THIS HAS RESULTED IN ANOTHER MORNING OF MOSTLY CLEAR SKIES...LOW DEWPOINTS...AND UNSEASONABLY COOL TEMPERATURES ACROSS THE DESERTS. REGIONAL OBS AS OF 09Z REVEAL TEMPERATURES IN THE MID 50S TO LOWER 60S...WHICH IS ALREADY 5-10 DEGREES BELOW NORMAL FOR MAY 10TH. THE AFOREMENTIONED SHORTWAVE WILL QUICKLY MOVE THROUGH THE AREA TODAY...ONLY BRINGING A SLIGHT INCREASE IN MID CLOUDS TO THE AREA. PRECIP CHANCES ARE LARGELY NIL TODAY ALTHOUGH I CAN`T RULE OUT A STRAY SHOWER OVER THE MOUNTAINS NORTH/EAST OF PHOENIX. ACCORDINGLY...I HAVE RETAINED 5-10 POPS EAST OF GLOBE. ANY SHOWERS THAT DEVELOP WILL DISSIPATE QUICKLY WITH THE LOSS OF DAYTIME HEATING...NOT TO MENTION INCREASING ANTICYCLONIC FLOW ALOFT AS RIDGING BEGINS TO STRENGTHEN ACROSS SOUTHERN CALIFORNIA. THE UPPER RIDGE WILL DEVELOP AND STRENGTHEN ACROSS SOUTHERN CALIFORNIA AND ARIZONA MONDAY THROUGH TUESDAY WITH TEMPERATURES QUICKLY RETURNING TO NORMAL VALUES. BIAS CORRECTED CONSENSUS GUIDANCE HAS BEEN SUGGESTING HIGHS IN THE MID 90S MONDAY THROUGH WEDNESDAY AND THIS IS STILL THE CASE WITH TODAY`S 00Z VALUES. VERY HIGH CONFIDENCE/LITTLE CHANGE IN THE FORECAST THROUGH MID WEEK. THINGS TURN A BIT MORE INTERESTING AS WE GET CLOSER TO THURSDAY...AND CERTAINLY BY FRIDAY INTO THE WEEKEND. ENSEMBLE MEANS OVER THE PAST FEW DAYS HAVE ADVERTISED PERSISTENT TROUGHING ACROSS THE WESTERN CONUS AS AN UPPER LOW MOVES THROUGH THE PAC NW INTO THE GREAT BASIN. DETERMINISTIC GUIDANCE HAS BEEN IN AGREEMENT FOR THE MOST PART DURING THIS LATE-WEEK PERIOD...ALTHOUGH NOT SURPRISINGLY EACH RUN OF EACH MODEL HAS VARIED SOMEWHAT UP UNTIL RECENTLY. YESTERDAY`S 12Z AND TODAY`S 00Z DETERMINISTIC GFS AND ECMWF HAVE COME INTO MUCH BETTER AGREEMENT...AND SUGGEST A SUBSTANTIAL INCREASE IN BL MOISTURE LATE IN THE WEEK COINCIDENT WITH THE ARRIVAL OF A VERY POTENT 500MB SHORTWAVE TROUGH. GFS IN PARTICULAR INDICATES PWATS CLIMBING INTO THE 0.8 TO 1.0 INCH RANGE ON FRIDAY...WHICH WOULD BE WELL INTO THE 99TH PERCENTILE OF OBSERVED PWATS ACROSS ARIZONA FOR THE MIDDLE OF MAY. WITH A PROLONGED RESIDENCE TIME OVER THE EASTERN PACIFIC...IT WILL CERTAINLY HAVE MORE THAN ENOUGH TIME TO ADVECT MOISTURE INTO THE AREA AND THE 00Z NAEFS AGREES /INTEGRATED WV TRANSPORT CLIMBS WELL INTO THE 90TH PERCENTILE ON FRIDAY/. ECMWF IS A BIT SLOWER AND SLIGHTLY DRIER...BUT HAS THE SAME BASIC IDEA. I WENT AHEAD AND INCREASED POPS ABOVE CLIMO /INTO THE 10-30 PERCENT RANGE/ FOR FRIDAY AND SATURDAY ALTHOUGH THE EXACT TIMING WILL NEED TO BE NAILED DOWN...AS ITS UNLIKELY WE`D SEE PERSISTENT SHOWERS FOR 2 STRAIGHT DAYS. ALSO TOOK A BIG SWING DOWNWARD WITH TEMPERATURES...CONSENSUS GUIDANCE YIELDS HIGHS IN THE UPPER 70S AND THIS SEEMS MORE THAN REASONABLE. OVERALL...CONFIDENCE IS HIGH IN THE DEVELOPMENT OF A COOL/WET LATE-WEEK PATTERN. CONFIDENCE IN EXACT TIMING OF THE ONSET OF SHOWERS AND STORM TOTAL PRECIP AMOUNTS IS LOW. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... DRY WESTERLY FLOW ALOFT PROVIDING CLEAR SKIES AND LIGHT WINDS THROUGH MONDAY AFTERNOON. WIND DIRECTIONS SHOULD MOSTLY FOLLOW TYPICAL DIURNAL PATTERNS. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... HIGH PRESSURE AND ITS ASSOCIATED WARMTH WILL RETURN TO THE DISTRICTS EARLY NEXT WEEK. THIS WILL RESULT IN TEMPERATURES RETURNING TO NEAR NORMAL VALUES WITH DRY CONDITIONS. MINIMUM AFTERNOON HUMIDITY LEVELS WILL FALL INTO THE SINGLE DIGITS AND TEENS WITH FAIR OVERNIGHT RECOVERY. BY THE MIDDLE PART OF THE WEEK ANOTHER SERIES OF PACIFIC STORMS WILL MOVE INTO THE WESTERN CONUS AND GENERATE BREEZY TO LOCALLY WINDY CONDITIONS FOR THE FIRE WEATHER ZONES. FIRST ON THURSDAY...LOWERING DAYTIME HUMIDITIES COUPLED WITH STRONG WINDS MAY DEVELOP AREAS OF CRITICAL FIRE WEATHER CONDITIONS OVER PORTIONS OF SOUTH-CENTRAL AZ. NEXT FOR THE LATE WEEK/NEXT WEEKEND...TEMPERATURES WILL BE BEGIN TO COOL AND DEWPOINTS COME UP SLIGHTLY AS A LARGER AND COOLER PACIFIC STORM IS NOW FORECAST INTO THE AREA. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...INIGUEZ/LEINS AVIATION...INIGUEZ FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
323 PM MDT SUN MAY 10 2015 .SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT) ISSUED AT 323 PM MDT SUN MAY 10 2015 NORTH TO NORTHWESTERLY FLOW CONTINUES ON THE BACK SIDE OF THE LOW PRESSURE SYSTEM THAT BROUGHT ALL THE SNOW AND RAIN YESTERDAY. THE NAM12/EC/GFS ALL SHOW A SHORTWAVE MOVING OVER THE FORECAST AREA THIS EVENING BRINGING ANOTHER ROUND OF PRECIP WITH MOUNTAINOUS TERRAIN SEEING MORE SNOWFALL. HOWEVER...THESE MODELS DID NOT INITIALIZE WELL THIS MORNING AND ARE CURRENTLY OVERDOING QPF/PRECIP. MEANWHILE...THE HRRR AND RAP13 APPEARED TO BE DOING MUCH BETTER WITH NAILING PRECIP AND WILL FOLLOW THESE SOLUTIONS IN THE SHORT TERM. FOR THIS AFTERNOON THEN...WITH COLD AIR ADVECTING IN...MINOR INSTABILITY EXISTS AND WITH CLOUDS BREAKING UP SOME...A FEW RUMBLES POSSIBLE THIS AFTN MAINLY FOR ERN UT AND SWRN CO. FOR THIS EVENING AND TONIGHT...THE RAP13 SHOWS ALMOST NO PRECIP WHILE THE HRRR DOES SHOW THE WAVE MOVING THROUGH BUT PRECIP AMTS ARE LIGHT AS THE DISTURBANCE QUICKLY MOVES OVERHEAD. PUT ISOLD/SCTD PRECIP FOR NORTHERN VALLEYS AND ALL HIGHER TERRAIN TONIGHT. NORTHERLY FLOW WILL ALSO BRING COOLER TEMPERATURES TO THE REGION WITH NORTHERN VALLEYS AND SOUTHERN VALLEYS SEEING FREEZING OR JUST BELOW FREEZING TEMPS. THESE TEMPS WILL BOTTOM OUT JUST BEFORE SUNRISE SO OPTED TO NOT ISSUE ANY FREEZE WARNINGS. HIGH PRESSURE WILL THEN BUILD IN BRINGING A PLEASANT START TO THE WORK WEEK. ANOTHER LOW DRIFTING SOUTHWARD ALONG THE PACIFIC NORTHWEST COAST WILL CAUSE A RIDGE TO BUILD OVER THE REGION. DECENT WARM AIR ADVECTION (WAA) COMBINED WITH A DRY SOUTHWEST FLOW WILL BRING MORE QUIESCENT WEATHER TO FORECAST AREA MONDAY. HOWEVER...12Z GFS DID SUGGEST THERE MAY BE ENOUGH RESIDUAL MOISTURE OVER THE EASTERN UINTA MOUNTAINS TO FUEL A FEW DIURNAL SHOWERS/THUNDERSTORMS. DESPITE WARMING...AFTERNOON HIGHS WILL REMAIN SEVERAL DEGREES BELOW NORMAL. DRY CONDITIONS PERSIST MONDAY NIGHT THOUGH THE RIDGE AXIS WILL SHIFT EAST OF THE CONTINENTAL DIVIDE BY 12Z/TUE AS THE NORTHWEST PACIFIC LOW PRESSURE SYSTEM MOVES ASHORE OVER SOUTHWEST OREGON. OVERNIGHT LOWS WILL FALL TO NEAR NORMAL LEVELS AS LOSS OF CLOUD COVER IS BALANCED BY WAA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 323 PM MDT SUN MAY 10 2015 THE LOW REMAINS NEARLY STATIONARY DURING THE DAY ON TUESDAY AS A STRONG VORTICITY LOBE MOVES THROUGH ITS BASE. MEANWHILE... ISENTROPIC FIELDS INDICATED A SURGE OF LOW LEVEL MOISTURE ORIGINATING FROM THE GULF OF MEXICO WILL MOVE NORTHWARD OVER THE CONTINENTAL DIVIDE FUELING SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON. OVER NORTHEAST UTAH...MODELS DIVIDED ON WHETHER ENOUGH MOISTURE WILL REMAIN OVER THE EASTERN UINTAS TO GENERATE MOIST CONVECTION DURING THE AFTERNOON. GIVEN MODEL DIFFERENCES WILL CONTINUE WITH LOW CHANCES OVER THE EASTERN UINTA MOUNTAINS. AS WAA ADVECTION CONTINUES...AFTERNOON HIGHS ARE EXPECTED TO CONTINUE TO INCREASE WITH LATEST GUIDANCE INDICATING HIGHS AROUND 5 DEGREES ABOVE NORMAL. SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO TUESDAY EVENING AND MAY PERSIST OVER THE SAN JUAN MOUNTAINS LATE INTO THE NIGHT AS A SHORTWAVE IN THE SOUTHERN STREAM MOVES ACROSS THE SOUTHWEST. EXPECT ANOTHER ROUND OF DIURNALLY DRIVEN MOIST CONVECTION WEDNESDAY AFTERNOON/EVENING WITH SOME ENHANCEMENT ACROSS THE SOUTH ASSOCIATED WITH THE SHORTWAVE TROUGH MENTIONED PREVIOUSLY. ON THURSDAY...THE TROUGH ALONG THE PACIFIC NORTHWEST SLIPS SOUTHWARD ALLOWING MOISTURE TO CONTINUE STREAMING NORTHWARD OVER THE DIVIDE. AS A RESULT...EXPECT SIMILAR CONDITIONS TO WEDNESDAY WITH STORMS LARGELY ANCHORED TO THE COLORADO MOUNTAINS. AFTERNOON HIGHS WILL CONTINUE TO RUN SEVERAL DEGREES ABOVE NORMAL AS WAA IN SOUTHWEST FLOW PERSISTS. HOWEVER...THE WARM PERIOD ENDS FRIDAY AS A SLUG OF PACIFIC MOISTURE DRIVEN ACROSS THE SOUTHWEST BY A VORTICITY LOBE EJECTED FROM THE LOW CENTERED OVER SAN FRANCISCO COMBINES WITH GULF MOISTURE ALREADY IN PLACE. DIABATIC COOLING ASSOCIATED WITH INCREASED CLOUDS AND SHOWERS WILL DRIVE COOLING WITH HIGHS DROPPING OFF BY ABOUT 10 DEGREES RELATIVE TO THURSDAY/S FORECAST HIGHS WITH READINGS COMING IN ABOUT 5 DEGREES BELOW NORMAL. MODELS IN FAIRLY GOOD AGREEMENT FOR THE WEEKEND WITH BOTH THE GFS AND ECMWF DEPICTING ANOTHER MOIST...COOL...AND UNSETTLED PERIOD AS THE LOW MOVES FROM THE WEST COAST AND ACROSS THE FORECAST AREA EVENTUALLY REACHING THE NORTHERN PLAINS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON MONDAY) ISSUED AT 1100 AM MDT SUN MAY 10 2015 KASE...KEGE...AND KTEX WILL LIKELY SEE THE BIGGEST IMPACT TODAY WITH CLOUDS AND PRECIP OFF AND ON THROUGH THE DAY. VFR/MVFR WILL BE COMMON. REMAINING TAF SITES WILL SEE CONDITIONS SLOWLY IMPROVE FROM SOUTH TO NORTH THROUGH THE DAY WITH VFR EXPECTED FOR THE MOST PART. SOME FOG IS POSSIBLE TOWARDS DAYBREAK BUT NOT QUITE CONFIDENT ENOUGH YET TO INCLUDE IN TAFS. MTN OBSCURATIONS WILL CONTINUE INTO THE OVERNIGHT PERIOD. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ SHORT TERM...TGR/NL LONG TERM...NL AVIATION...TGR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1058 AM MDT SUN MAY 10 2015 .UPDATE... ISSUED AT 1048 AM MDT SUN MAY 10 2015 SHORT RANGE GUIDANCE...THE HRRR AND RAP...CONTINUE TO DOWNPLAY PRECIP FROM THIS NEXT WAVE THAT IS PROGGED TO MOVE OVER THE AREA THIS EVENING. RAP HAS ALMOST NO PRECIP WHILE HRRR DOES SHOW SOME QPF BUT VERY QUICK MOVING AND LIGHT. NAM AND GFS GUIDANCE NOT PANNING OUT SO FAR THIS MORNING AS THEY BOTH PAINT MUCH MORE WIDESPREAD PRECIP THAN IS OCCURRING. ALL ROADS ARE NOW WET WITH LITTLE TO NO SNOW OR ICE SEEN ON WEBCAMS. WILL FOLLOW HRRR/RAP LEAD AND UPDATE FORECAST AND LOWER POP/QPF AMTS...ALSO WENT AHEAD AND DROPPED HIGHLIGHTS. EXPECT PLENTY OF CLOUDS FOR THE MTNS...REMAINING AREAS WILL SEE CLOUDS BREAKING UP THROUGH THE AFTERNOON. AREAS SOUTH AND WEST MAY SEE PARTLY CLOUDY SKIES. UPDATE ISSUED AT 857 AM MDT SUN MAY 10 2015 CLOUDS AND PRECIPITATION CONTINUE ACROSS MUCH OF THE CWA AS LOW PRESSURE...NOW CENTERED OVER THE PLAINS...CONTINUES MOVING NEWRD. SHORT RANGE MODELS CONTINUE PICKING UP ON SHORTWAVE MOVING ACROSS THE AREA LATER THIS AFTERNOON AND EVENING WHEN THE COLDEST TEMPS START DROPPING DOWN FROM THE NORTH. ANY ICE OR SNOW ON ROADS SHOULD HAVE MELTED BY NOW BUT WITH ONGOING PRECIP AND LOWERED VISIBILITIES...THINK ENOUGH OF AN IMPACT TO KEEP HIGHLIGHTS GOING. WILL KEEP AN EYE ON NEXT DISTURBANCE AND HOW IT EVOLVES AS THE DAY PROGRESSES. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 323 AM MDT SUN MAY 10 2015 AS UPPER LEVEL LOW PRESSURE OVER NE CO LIFTS INTO THE NRN PLAINS SUNDAY...A WEAK SHORTWAVE TROUGH DROPS SOUTH FROM MT INTO EASTERN UT BY SUNDAY EVENING AND THEN EAST ACROSS CO SUNDAY NIGHT. MID AND UPPER LEVEL MOISTURE ASSOCIATED WITH TROWAL PATTERN OF DEPARTING LOW HANGS AROUND THRU SUNDAY...ESPECIALLY ACROSS THE NORTHERN HALF OF THE AREA AND WILL BE AVAILABLE FOR THE MONTANA SHORTWAVE TO USE TO DEVELOP ADDITIONAL SHOWERS AND ISOLATED THUNDERSTORMS FOR THE LATTER HALF OF SUNDAY. SNOW LEVELS WILL REMAIN LOW...ONLY REBOUNDING TO AROUND 7500 FEET NORTH TO 9000 FEET SOUTH SUNDAY AFTERNOON...SO ADDITIONAL ACCUMULATIONS OF SNOWFALL LIKELY FOR THE HIGHER ELEVATIONS. WILL LEAVE THE WINTER STORM WARNINGS/ADVISORIES AS THERE ARE FOR THE EARLY MORNING HOURS TO KEEP AWARENESS HIGH FOR HAZARDOUS TRAVEL...BUT EXPECT THAT AT LEAST SOME OF THE HEADLINES WILL BE ABLE TO BE DROPPED BY MIDDAY. UPPER LEVEL RIDGE BUILDS ACROSS THE REGION MONDAY BRINGING A RESPITE FROM THE WET WEATHER...ABUNDANT SUNSHINE AND MILDER TEMPERATURES. HOWEVER...CANNOT RULE OUT ISOLATED CONVECTION OVER THE TYPICAL DIURNALLY DRIVEN FAVORABLE SPOTS IN THE MOUNTAINS. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 323 AM MDT SUN MAY 10 2015 UNSETTLED CONDITIONS WILL CONTINUE FOR MUCH OF THE WEEK AS WE SEE ANOTHER SURGE OF MOISTURE WORK NORTH TUESDAY...THEN WE START TO WORK ON DAILY RECYCLING OF LOW LEVEL MOISTURE LEFT OVER THE REGION THROUGH THURSDAY. EXPECTED MAINLY DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS...CONFINED TO THE HIGHER TERRAIN WITH A FEW CELLS TRAVELING OVER THE VALLEYS LATE IN THE DAY. TEMPS WILL BE JUMPING BACK TO ABOVE NORMAL READINGS BY MIDWEEK IN STRENGTHENING SOUTHWEST FLOW. ALL OF THIS IS AHEAD OF YET ANOTHER WEEKEND STORM THAT WILL BEGIN TO IMPACT THE FORECAST AREA FRIDAY AFTERNOON AS WE SEE A STRONGER SURGE OF EASTERN PACIFIC MOISTURE WORK NORTH OFF THE BAJA AND INTO WESTERN COLORADO. INCREASINGLY DIFLUENT FLOW AHEAD OF THE DIGGING LOW THAT SLIDES INTO THE GREAT BASIN ON SATURDAY PROMISES FAIRLY WIDESPREAD PRECIPITATION BEGINNING FRIDAY NIGHT AND CONTINUING INTO SUNDAY. GFS AND ECMWF IN MUCH BETTER AGREEMENT WITH THIS LATEST MODEL RUN...TAKING THE NEW CLOSED LOW AND LIFTING IT NORTH NORTHEAST INTO WYOMING BY SUNDAY MORNING AND INTO THE WESTERN DAKOTAS BY SUNDAY NIGHT. WITH SOME MODEL CONSISTENCY DEVELOPING...CONFIDENCE INCREASING A BIT AND WILL RAMP POPS UP A BIT...BUT STILL BELOW LIKELY THRESHOLDS AS WE WAIT FOR A LITTLE RUN TO RUN CONSISTENCY. TEMPS EXPECTED TO DROP BACK BELOW NORMAL OVER THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON MONDAY) ISSUED AT 1100 AM MDT SUN MAY 10 2015 KASE...KEGE...AND KTEX WILL LIKELY SEE THE BIGGEST IMPACT TODAY WITH CLOUDS AND PRECIP OFF AND ON THROUGH THE DAY. VFR/MVFR WILL BE COMMON. REMAINING TAF SITES WILL SEE CONDITIONS SLOWLY IMPROVE FROM SOUTH TO NORTH THROUGH THE DAY WITH VFR EXPECTED FOR THE MOST PART. SOME FOG IS POSSIBLE TOWARDS DAYBREAK BUT NOT QUITE CONFIDENT ENOUGH YET TO INCLUDE IN TAFS. MTN OBSCURATIONS WILL CONTINUE INTO THE OVERNIGHT PERIOD. && .HYDROLOGY... ISSUED AT 323 AM MDT SUN MAY 10 2015 MOST RIVERS IN WESTERN COLORADO REMAIN WELL BELOW BANKFULL STAGES ALTHOUGH RECENT RAINFALL INCREASED FLOWS IN THE RIVERS. EVEN SO...A FEW SMALLER STREAMS AND CREEKS DID INCREASE TO NEAR BANKFULL. THE UPPER YAMPA RIVER IS AT BANKFULL FROM THE COMBINATION OF RECENT RAIN AND SNOW MELT AND WILL REMAIN NEAR OR SLIGHTLY ABOVE BANKFULL THROUGH THE REMAINDER OF THE WEEKEND. THE UPPER HEADWATERS OF THE MAINSTEM RIVERS...SMALL STREAMS AND CREEKS COULD ALSO SEE ANOTHER INCREASE IN FLOWS FROM ADDITIONAL PRECIPITATION TODAY AND TONIGHT. THE MAINSTEM RIVERS WILL REMAIN BELOW BANKFULL LEVELS BUT COULD ALSO SEE INCREASES IN FLOWS. LOCALIZED FLOODING IS POSSIBLE UNDER THE STRONGEST RAINFALL DUE TO SATURATED SOILS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ UPDATE...TGR SHORT TERM...BM LONG TERM...JDC AVIATION...TGR HYDROLOGY...JDC/AS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1031 PM EDT MON MAY 11 2015 .SYNOPSIS... A COLD FRONT NEAR THE MOHAWK VALLEY...AND CENTRAL NEW ENGLAND WILL CONTINUE TO BRING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE REGION OVERNIGHT. THE FRONT MOVES THROUGH EASTERN NEW YORK AND WESTERN NEW ENGLAND TOMORROW INTO TOMORROW NIGHT. THE AIR MASS WILL TURN COOLER AND DRIER ON WEDNESDAY WITH TEMPERATURES BACK TO NEAR NORMAL OR SLIGHTLY BELOW NORMAL READINGS FOR MAY. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 1030 PM EDT...THE COLD FRONT HAS BECOME STATIONARY NEAR THE MOHAWK VALLEY...LAKE GEORGE REGION...AND SRN VT THIS HOUR. ONE CLUSTER OF SHOWERS WITH A FEW RUMBLES OF THUNDER IS MOVING ACROSS THE SRN DACKS...AND THE NRN REACHES OF THE MOHAWK VALLEY. THIS SHOULD MOVE ACROSS THE REGION IN THE NEXT FEW HOURS. A MORE IMPRESSIVE LINE OF SHOWERS AND THUNDERSTORMS IS MOVING ACROSS WRN NY. THE GENERAL TREND FROM THE LATEST HRRR/HIRES WRF IS FOR A WEAKENING TREND AS THE LINE MOVES EASTWARD. THIS LINE LOOKS TO GET INTO OUR FCST AREA BTWN 06Z-09Z/TUE...AND WEAKEN FURTHER AS IT MOVES EAST OF THE HUDSON RIVER VALLEY BWTN 09Z-12Z. WE KEPT A SLIGHT OR LOW CHC THUNDERSTORMS IN THE FCST AREA THRU THE OVERNIGHT PERIOD. THE LATEST MESOANALYSIS RAP ON THE SPC PAGE SHOULD SBCAPES AROUND 500 J/KG FROM THE CAPITAL REGION SOUTH AND EAST WHERE THE AIR MASS REMAINS MUGGY WITH SFC DEWPTS IN THE LOWER TO M60S. FURTHER NORTH...THE AIR MASS IS A BIT MORE STABLE DUE TO THE MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS. SOME LOCALLY HEAVY RAINFALL WILL CONTINUE OVERNIGHT WITH HIGH PWAT VALUES IN PLACE...A FEW STD DEVS ABOVE NORMAL. LOWS OVERNIGHT ARE EXPECTED TO BE VERY MILD...MAINLY IN THE LOWER TO M60S...EXCEPT SOME MID AND U50S OVER THE SRN DACKS...AND SRN VT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... THE FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT LAKES EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY HOURS TO EARLY AFTERNOON ON TUESDAY AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA. SO THE BEST CHANCES FOR CONVECTION LOOK TO BE THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT HIGHS ON TUESDAY IN UPPER 60S TO LOWER 80S WITH TEMPS FALLING LATE IN THE DAY AS COLD AIR ADVECTION TAKES HOLD. TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE WELL EAST OF THE REGION BY TUESDAY EVENING. HOWEVER...THE UPPER LEVEL TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING ACROSS MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW OF SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN CATSKILLS...AND BERKSHIRES NORTHWARD. IT WILL BE BRISK AND MUCH COOLER TUESDAY NIGHT AND WEDNESDAY WITH LOWS TUESDAY NIGHT IN THE UPPER 30S TO UPPER 40S AND HIGHS ON WEDNESDAY IN THE MID 50S TO MID 60S. WEDNESDAY NIGHT AND THURSDAY WILL BE MARKED BY CLEAR SKIES AND COOL CONDITIONS WITH FROST POSSIBLE ON WEDNESDAY NIGHT AS TEMPERATURES DROP INTO THE UPPER 20S TO UPPER 30S. WILL HIGHLIGHT THIS IN THE HWO EXCEPT FOR THE SOUTHERN ADIRONDACKS WHERE THE GROWING SEASON HAS NOT STARTED YET. HIGHS ON THURSDAY WILL BE IN THE 60S. && .LONG TERM /THURSDAY THROUGH MONDAY/... THE PERIOD STARTS OUT DRY...BUT DIFFUSE OR WEAK FRONTAL BOUNDARIES WILL BRING AT LEAST A CHANCE OF SHOWERS FOR FRIDAY NIGHT AND SATURDAY. THEREAFTER...THE HUMIDITY WILL HANG AROUND...BUT MOST LOCATIONS WILL BE LOOKING AT ONLY SLIGHT CHANCES OF SHOWERS. INSTABILITY APPEARS TO BE TOO LOE FOR THUNDERSTORMS. HIGH TEMPERATURES WILL INCREASE FROM A RANGE OF LOWER AND MID 60S TO THE MID 70S FRIDAY AND SATURDAY...TO FROM THE LOWER AND MID 70S TO THE LOWER AND MID 80S ON SUNDAY. OVERNIGHT LOWS WILL ALSO MODERATE EACH DAY...STARTING OUT WITH A THURSDAY NIGHT RANGE FROM THE UPPER 30S TO UPPER 40S...AND CULMINATING WITH SUNDAY NIGHT LOWS IN THE MID AND UPPER 50S. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... AS OF EARLY THIS EVENING A STATIONARY FRONT LAY ACROSS CENTRAL AND WESTERN NEW YORK AND CENTRAL NEW ENGLAND WITH MOST OF THE SHOWERS AND THUNDERSTORMS FIRING ACROSS THE FA NORTH AND ALONG THIS BOUNDARY. AS A RESULT WILL CONTINUE TO MENTION THUNDER AT KGFL FOR THE NEXT COUPLE OF HOURS. FURTHER SOUTH AND EAST AT KALB/KPSF/KPOU...ACTIVITY COVERAGE LOOKS LESS. WINDS THIS EVENING WILL BE SOUTHERLY AT AROUND 10 KTS WITH GUSTS TO AROUND 20 KTS. THERE SHOULD BE A LULL IN THE RAINFALL ACTIVITY FOR MOST OF THE OVERNIGHT HOURS AS THE WARM FRONT LIFTS NORTHWARD...AND COLD FRONT REMAINS OFF TO THE WEST AROUND THE EASTERN GREAT LAKES. HOWEVER...MOIST LOW LEVELS WITH PERSISTENTLY MOIST SOUTHERLY FLOW WILL ALLOW FOR SOME MVFR CIGS/VSBY LATE TONIGHT...ESP FOR KPSF/KPOU...WHERE WINDS ARE EXPECTED TO BECOME LIGHT/CALM. SOME MORE SHOWERS WILL BE POSSIBLE WITH THE PASSAGE OF FRONTAL BOUNDARY EARLY TUESDAY MORNING AS IT FINALLY REACHES OUR AREA FROM THE WEST. SHOWERS SHOULD END BY THE LATE MORNING...AS COLD FRONT PASSES THROUGH AND WINDS BECOME WEST...AND BECOME GUSTY. CIGS SHOULD QUICKLY CLEAR OUT FOR ALL SITES BEHIND THE FRONT. OUTLOOK... TUESDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. ISOLATED SHRA. WEDNESDAY: MODERATE OPERATIONAL IMPACT. WINDY. ISOLATED SHRA. WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX. THURSDAY TO FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. && .FIRE WEATHER... FIRE WEATHER WATCH FOR BERKSHIRE COUNTY FROM 11 AM UNTIL 8 PM ON TUESDAY. A COLD FRONT OVER NORTHERN NEW YORK AND NEW ENGLAND WILL BRING MORE WIDESPREAD CHANCES OF SHOWERS AND THUNDERSTORMS FROM THIS AFTERNOON INTO TUESDAY BEFORE THE FRONT MOVES THROUGH OUR REGION. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS. THE COLD FRONTAL PASSAGE WILL USHER IN MUCH COOLER AND DRIER AIR BY WEDNESDAY. RELATIVE HUMIDITY VALUES WILL RECOVER TO 85 TO 100 PERCENT TONIGHT...DROP TO 30 TO 45 PERCENT ON TUESDAY...RECOVER TO 70 TO 100 PERCENT TUESDAY NIGHT...AND DROP TO 35 TO 50 PERCENT ON WEDNESDAY. WINDS ARE EXPECTED TO BE SOUTH TO SOUTHEAST AT LESS THAN 15 MPH TONIGHT AND WEST AT 10 TO 20 MPH WITH GUSTS TO 35 MPH BY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT AND NORTHWEST WINDS OF 10 TO 20 MPH WITH GUSTS TO 35 MPH ON WEDNESDAY. && .HYDROLOGY... THERE WILL BE GRADUALLY INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS SPREADING SOUTH AND EAST THROUGH TUESDAY...AS A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH AND EVENTUALLY MOVE THROUGH THE REGION. IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS. THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH THUNDERSTORMS ESPECIALLY THOSE WHICH TRAIN...ALTHOUGH RAINFALL WILL BE BENEFICIAL IN MOST PLACES DUE TO VERY DRY ANTECEDENT GROUND CONDITIONS. BASIN-AVERAGE RAINFALL WILL NOT BE UNIFORM DUE TO THE CONVECTIVE NATURE OF THE PRECIPITATION. THE WESTERN MOHAWK VALLEY...SOUTHERN ADIRONDACKS AND LAKE GEORGE SARATOGA REGION HAVE THE BEST CHANCES TO SEE A HALF INCH TO INCH OF RAIN OR MORE THROUGH TUESDAY. THE SCHOHARIE VALLEY...CAPITAL DISTRICT TO SOUTHERN VERMONT AND POINTS SOUTH ARE EXPECTED TO GET A TENTH OF AN INCH TO A THIRD OF AN INCH WITH LOCALIZED HIGHER AMOUNTS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR MAZ001-025. VT...NONE. && $$ SYNOPSIS...11/WASULA NEAR TERM...11/WASULA SHORT TERM...11 LONG TERM...ELH AVIATION...FRUGIS/11 FIRE WEATHER...11 HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1007 PM EDT MON MAY 11 2015 .SYNOPSIS... ANOTHER MILD AND HUMID NIGHT WITH DENSE FOG TONIGHT GIVES WAY TO ANOTHER WARM DAY WITH SOME SHOWERS AND THUNDERSTORMS POSSIBLE IN THE AFTERNOON AS THE REMNANTS OF ANA PASS BY. LARGE HIGH PRESSURE WILL BUILD ACROSS THE EASTERN U.S. WITH DRIER WEATHER THROUGH THE REMAINDER OF THE WEEK. AN APPROACHING WARM FRONT COULD BRING SCATTERED SHOWERS NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 10 PM UPDATE... BACKDOOR FRONT APPEARS TO HAVE STALLED FROM NE RI THROUGH PORTIONS OF SE MA. TEMPS IN THE 50S TO THE N AND E OF THE FRONT AND MAINLY 60S JUST TO THE S AND W. AS REMNANTS OF ANA APPROACHES LATE TONIGHT...HI-RES GUIDANCE LIFTS THE FRONT BACK TO THE N OVERNIGHT ACROSS RI AND SE MA. AREAS OF DENSE FOG HAVE OVERSPREAD THE IMMEDIATE S COAST THIS EVENING. WITH LOW LEVEL S/SW FLOW EXPECT DENSE FOG THREAT WILL BE CONFINED TO THE S COAST AND SE MA...AND ALONG NE MA COAST WHERE WINDS ARE EASTERLY. LATEST HRRR HAS LOWEST VSBYS ALONG THE S AND E COASTS SO WE TRIMMED THE DENSE FOG ADVISORY AWAY FROM THE COAST. FINALLY...HAVE INCREASED POPS ACROSS SE COASTAL MA AND CAPE COD FOR LATE TONIGHT AS REMNANTS OF ANA TRACK TO THE SOUTH. MODELS SHOW AREA OF DEEPER MOISTURE ALONG WITH SOME ELEVATED INSTABILITY AT THE NOSE OF A LOW LEVEL JET WHICH SHOULD BRING AN AREA OF SHOWERS OR AN ISOLD TSTM TO SE COASTAL NEW ENG. LATEST RAP SHOWS AN AREA OF MEASURABLE RAINFALL LATE TONIGHT OVERSPREADING PORTIONS OF RI AND SE MA. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... TOMORROW... THE EARLY MORNING WILL BE MARKED BY A FAIRLY ROBUST DECK OF LOW LVL CLOUDS AND FOG POSSIBLY AS FAR WEST AS THE CT VALLEY. THIS WILL TAKE SOME TIME TO BURN OFF DURING THE MORNING AS DIURNAL MIXING COMMENCES. EXACTLY HOW QUICKLY WILL DETERMINE THE THREAT FOR CONVECTION/SEVERITY AS A COLD FRONT APPROACHES FOR THE AFTERNOON. BY AFTERNOON...AS THE FRONT MAKES IT/S PASS/APPROACH...SOME BREAKS OF SUN ARE LIKELY ESPECIALLY FOR INTERIOR NRN MA AND WRN CT. THIS AREA WILL BE THE PLACE TO WATCH AS BUFKIT PROFILES SHOW MODEST CAPE VALUES APPROACHING 1000-1500 J/KG COMBINED WITH ABOUT 30 KT OF 0-3KM SHEAR. UPPER LVL PROFILES WILL BE DRYING HOWEVER RATHER QUICKLY SO IT/S A RACE AGAINST TIME AS TO WHETHER THE DRY AIR OR INSTABILITY WINS AS THE LOW LVL F-GEN SOURCE APPROACHES. HI-RES AND EVEN MORE COARSE GUIDANCE ALL SHOWING THE POSSIBILITY OF AFTERNOON CONVECTIVE ACTIVITY WITH THE FROPA...ESPECIALLY NRN INTERIOR MA AWAY FROM WHERE THE LOW LVL CLOUDS WILL HOLD IN. SLIGHT CHANCE OF A STRONG STORM GIVEN THE MODEST SHEAR VALUES...WHICH COINCIDES WELL WITH THE 18Z DAY TWO SWODY FROM SPC...WHICH HIGHLIGHTS A MARGINAL RISK. THERE WILL STILL BE SOME LEFTOVER LOW-LVL MOISTURE FROM ANA AHEAD OF THE FRONT...SO WILL ALSO NEED TO WATCH FOR HEAVIER RAIN. OTHER ISSUES FOR TOMORROW... FIRE WEATHER CONCERNS... AREAS WHERE THE CLOUD DISSIPATE WILL SEE LOW RELATIVE RH VALUES AND GIVEN DIURNAL MIXING...WIND GUSTS OF 25-30 MPH AT TIMES. THEREFORE...HAVE A MARGINAL RISK OF ELEVATED FIRE WEATHER DURING THE DAY IN SPITE OF THE T-STORM/SHRA POTENTIAL. FOR MORE ON THIS...SEE THE FIRE WEATHER SECTION BELOW. HIGH SURF... THE REMNANTS OF ANA WILL BRING 6 TO 10 FOOT SWELL TO OUR SOUTHERN COASTAL WATERS TOMORROW. THIS WILL BRING HIGH SURF AND DANGEROUS RIP CURRENTS TO OUR OCEAN EXPOSED SOUTH FACING BEACHES ON TUE. GIVEN RELATIVELY WARM TEMPS EXPECTED...WE MAY STILL HAVE TO CONSIDER A HIGH SURF ADVISORY EVEN THOUGH THE SUMMER SEASON HAS NOT OFFICIAL BEGUN. TUESDAY NIGHT... FINALLY...THE HIGHER DWPTS...DRIER AIR AND IMPROVING CONDITIONS WILL BE MOVING ACROSS THE REGION FROM W-E DURING THE OVERNIGHT HOURS. LEFTOVER TSRA/SHRA WILL GENERALLY DIMINISH WITH THE LOSS OF DIURNAL HEATING...SO THERE MAY BE A FEW CLOUDS STILL TO CONTEND WITH EARLY. GIVEN THE MASS FIELDS ALSO SUPPORT A MODERATE PRES GRADIENT...TEMPS ARE NOT LIKELY TO FALL AS LOW AS THEIR POTENTIAL DESPITE THE DROPPING DWPTS. MINS MAINLY IN THE MID 40S AND LOW 50S. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HIGHLIGHTS... * BREAK IN THE HEAT ON WEDNESDAY WITH NORMAL TEMPS * HIGH PRESSURE ON THURS & FRI KEEP CONDITIONS DRY * RAIN RELIEF POSSIBLE OVER THE WEEKEND WITH APPROACHING LOW OVERVIEW... FORECAST GUIDANCE CONTINUES TO BE IN GOOD AGREEMENT FOR MOST OF THE EXTENDED. NOTICED 11.12Z GUIDANCE LEANED TOWARDS THE 11.00Z GFS FROM LAST NIGHT IN BRINGING PRECIP INTO THE REGION FOR THE WEEKEND. OTHERWISE BY LATE WEEKEND INTO EARLY NEXT WEEK APPEARS THAT THE EC IS MORE AMPLIFIED IN BUILDING A STOUT RIDGE OVER NEW ENGLAND COMPARED TO THE GFS. THIS COULD MAKE THINGS LESS STORMY THEN PREVIOUSLY THOUGHT. APPEARS TEMPS WILL LEAN MORE TOWARDS OR JUST ABOVE NORMAL OVER THE LONG TERM. COULD SEE AN INCREASE IN THE HEAT BY NEXT WEEK. DETAILS... * WEDNESDAY...HIGH CONFIDENCE. SECONDARY COLD FRONT WILL PASS THROUGH THE REGION PUSHING UPPER LEVEL TROUGH OFFSHORE AND TEMPS ALOFT TO COOL OVER THE AREA. WINDS WILL SWITCH TO A MORE NW FLOW...ALLOWING FOR GOOD DOWNSLOPING. PARTLY SUNNY SKIES WILL ALLOW FOR TEMPS TO WARM INTO THE UPPER 60S...WHICH IS NEAR NORMAL! DID LOWER DEWPOINTS AND INCREASE WIND GUSTS VERSUS GUIDANCE AS MIXING ON WED WILL BE VERY GOOD. THIS WILL BRING A RISK OF FIRE WEATHER CONCERNS TO THE REGION. DETAILS IN THE FIRE WEATHER SECTION BELOW. BECAUSE OF THE FALLING TEMPS ALOFT AND MARGINAL MOISTURE FIELD... HAVE INSERTED A LOW CHANCE FOR AN ISOLATED SHOWER FOR FRANKLIN COUNTY. CONFIDENCE IS LOW...BUT CANNOT RULE IT OUT. TEMPS ALOFT WILL DROP THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS. IN FACT 850MB COULD DROP DOWN TO 0C OVERNIGHT. THIS COMBINED WITH CLEAR SKIES AND DECOUPLE WINDS WILL ALLOW FOR RADIATIONAL COOLING OVERNIGHT. TEMPS WILL DROP INTO THE LOWER 40S. COULD SEE A FEW UPPER 30S BUT HAVE A LOW CONFIDENCE ON FROST DEVELOPMENT IN THE VALLEY LOCALS ACROSS THE NW PORTION OF THE AREA. * THURSDAY AND FRIDAY...HIGH CONFIDENCE. HIGH PRESSURE WILL MOVE RIGHT ON IN FOR THURSDAY AND LAST INTO FRIDAY. THIS WILL ALLOW FOR DRY WEATHER AND PLENTY OF SUNSHINE. HAVE AN INCREASE CHANCE THAT SEA BREEZES WILL DEVELOP ACROSS THE COASTLINES FOR BOTH DAYS. TEMPERATURES WILL WARM ABOVE AVERAGE ONCE AGAIN...WITH HIGHS IN THE LOW 70S ON THURSDAY AND MID 70S ON FRIDAY AWAY FROM THE COASTLINES. * THE WEEKEND...MODERATE CONFIDENCE. HIGH PRESSURE WILL MOVE SOUTH AND OFFSHORE ALLOWING FOR APPROACHING LOW PRESSURE FROM THE WEST TO PUSH A WARM FRONT OVER THE REGION. DEPENDING ON WHERE THIS WARM FRONT SETS UP WE COULD SEE A FEW ROUNDS OF SHOWERS AS A WAVE OR TWO MOVES THROUGH THE AREA. NOT EXPECTING A DROUGHT BUSTER AS WE NEED ABOUT 3-5 INCHES...BUT SOME RAIN RELIEF TO THE REGION IS ANTICIPATED. * MONDAY...LOW CONFIDENCE. MONDAY IS LOOKING WARM BUT STILL UNCERTAIN ON PRECIP CHANCES AS THE PATTERN WILL BE FOCUSED ON IF THE RIDGE WILL BUILD OR NOT. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. THROUGH TONIGHT...MODERATE CONFIDENCE. LIFR FOG HAS OVERSPREAD THE SOUTH COAST AS OF 02Z WITH IFR/LIFR STRATUS FURTHER N ACROSS E COASTAL MA. EXPECT STRATUS TO EXPAND ACROSS REST OF SNE OVERNIGHT...BUT DENSE FOG LIKELY CONFINED TO COASTAL LOCATIONS. LATE NIGHT SHOWERS POSSIBLE...WHICH ACTUALLY MAY ACT TO LIFT CONDITIONS BRIEFLY OUT OF IFR MAINLY IN RI AND SE MA. TOMORROW AND TOMORROW NIGHT...HIGH CONFIDENCE. EARLY DAY...MIX OF LIFR/IFR IN THE MORNING GIVES WAY TO GRADUAL IMPROVEMENT TO VFR THROUGH MID DAY. MAY TAKE UNTIL AFTERNOON TO FULLY ERODE STRATUS IN SOME LOCATIONS. OTHERWISE...CHANCE OF AN AFTERNOON SHOWER/T-STORM IN THE INTERIOR. KBOS TAF...MODERATE CONFIDENCE. IFR CONDITIONS ARE LIKELY TO PERSIST INTO TOMORROW MORNING FOR THE MOST PART. BRIEF LIFTS ARE POSSIBLE. WINDS REMAIN NE THROUGH EARLY MORNING...AT WHICH POINT THEY SHIFT BACK TO THE S. KBDL TAF...MODERATE CONFIDENCE. VFR GIVES WAY TO IFR TONIGHT. OUTLOOK...WEDNESDAY THROUGH SATURDAY...HIGH CONFIDENCE. WEDNESDAY...VFR. WINDS SWITCHING FROM SW TO NW AND INCREASING CLOSE TO 25-30 KTS. THURSDAY-FRIDAY...VFR. LIGHT AND VARIABLE WINDS. SEA BREEZES POSSIBLE ON BOTH DAYS. SATURDAY...VFR/MVFR WITH AN INCREASE IN SHOWERS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY NIGHT/... TONIGHT INTO TOMORROW...MODERATE CONFIDENCE. LEFTOVER SWELL FROM ANA WILL BEGIN TO BUILD ALONG THE S COASTAL WATERS LATE. REACHING A PEAK OF ABOUT 7-9 FT BY THE MID DAY TOMORROW. SMALL CRAFT ADVISORIES CONTINUE FOR THIS THREAT. OTHERWISE...WINDS REMAIN GENERALLY OUT OF THE S-SW UNTIL A COLD FRONTAL PASSAGE TOMORROW LATE IN THE DAY...AT WHICH POINT THEY SHIFT W. THERE IS THE LOW THREAT FOR SOME THUNDERSTORMS...MAINLY ACROSS THE E WATERS LATE IN THE DAY TOMORROW. FOG/STRATUS WILL ONCE AGAIN YIELD NEAR ZERO VSBYS ACROSS THE WATERS TONIGHT INTO TOMORROW. TOMORROW NIGHT...HIGH CONFIDENCE. SLOW IMPROVEMENT AS WINDS SHIFT TO THE W. ANY SHOWERS/STORMS WILL END AND SCOUR OUT THE LEFTOVER FOG. SEAS WILL ALSO GRADUALLY DECLINE SUCH THAT SMALL CRAFT ADVISORIES MAY BE DROPPED BY THE EARLY MORNING HOURS. OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE. WEDNESDAY...LINGERING 5FT SEAS WILL CONTINUE ON WED. HOWEVER GUSTS WILL BE ON THE INCREASE TO 25 KTS ESP ACROSS THE INTERIOR WATERS...SCA WILL BE NEEDED. THURSDAY-FRIDAY...HIGH PRESSURE BUILDS OVER THE WATERS. WINDS AND SEAS WILL BE BELOW SMALL CRAFT CRITERIA. SATURDAY...WARM FRONT WILL PUSH OVER THE WATERS INCREASING PRECIP CHANCES. BUT BOTH WINDS AND SEAS WILL REMAIN BELOW SCA. && .FIRE WEATHER... TOMORROW...TEMPERATURES MAY RISE TO NEAR 90 IN THE LOWER CT VALLEY OF MA AND CT WITH DWPTS HOLDING IN THE 50S AND 60S. THERE IS THE POSSIBILITY THEREFORE...THAT MIN RH VALUES WILL FALL TO AROUND 25-35 PERCENT IN PORTIONS OF SW MA DURING THE DAY. SW WINDS WILL GUST 25-30 MPH AT TIMES BY THE AFTERNOON. ALSO...THERE IS THE THREAT FOR THUNDERSTORMS AND ACCUMULATING RAINFALL...BUT THESE WILL GENERALLY BE HIT OR MISS AND WILL NOT PROVIDE THE WIDESPREAD RAINFALL THAT MUCH OF THE REGION REQUIRES. A FIRE WEATHER WATCH WILL BE ISSUED FOR SW PORTIONS OF MA DUE TO THE COLLOCATION OF DRIEST RH VALUES...HIGHEST WINDS AND LOWEST THREAT FOR RAINFALL. WEDNESDAY...A HIGHER RISK FOR FIRE WEATHER DEVELOPMENT IS EXPECTED ON WEDNESDAY...HOWEVER IT WILL BE DEPENDENT ON PRECIP CHANCES OVER THE NEXT 24-48 HOURS. SECONDARY COLD FRONT WILL PUSH THROUGH WED MORNING ALLOWING FOR WINDS TO BE MORE OUT OF THE NW. THIS WILL ALLOW FOR A DOWNSLOPING EFFECT...WHICH WILL INCREASE THE WIND GUSTS AND LOWER DEWPOINTS. RIGHT NOW BELIEVE THAT RH VALUES WILL DROP TO AROUND 30 PERCENT ACROSS MUCH OF THE REGION WITH NW WINDS GUSTING TO NEAR 30 MPH. ONLY DIFFERENCE COMPARED TO THE PREVIOUS DAYS IS HIGH TEMPS WILL WARM ONLY INTO THE UPPER 60S. HOWEVER APPEARS THAT THERE WILL BE A GOOD AMOUNT OF SUNSHINE ACROSS MOST OF THE REGION. WILL NEED TO CONTINUE TO MONITOR WEDNESDAY FOR POSSIBLE HEADLINES. THURSDAY AND FRIDAY...DRY WEATHER CONDITIONS WILL CONTINUE WITH RH VALUES DROPPING WELL INTO THE 20 PERCENT LEVEL AND WITH FULL SHINE. SINCE HIGH PRESSURE WILL BE OVERHEAD WIND WILL BE LIGHT AND VARIABLE...GUSTS COULD REACH 10-15 MPH. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...DENSE FOG ADVISORY UNTIL 10 AM EDT TUESDAY FOR MAZ020>024. DENSE FOG ADVISORY UNTIL 10 AM EDT TUESDAY FOR MAZ006-007- 014>016-018-019. FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR MAZ008>012. RI...DENSE FOG ADVISORY UNTIL 10 AM EDT TUESDAY FOR RIZ005>008. MARINE...SMALL CRAFT ADVISORY FROM 9 AM TO 8 PM EDT TUESDAY FOR ANZ235- 237. SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR ANZ254>256. && $$ SYNOPSIS...DOODY/DUNTEN NEAR TERM...KJC/DOODY SHORT TERM...DOODY LONG TERM...DUNTEN AVIATION...DOODY/DUNTEN MARINE...DOODY/DUNTEN FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS ALBANY NY
130 AM EDT SUN MAY 10 2015 .SYNOPSIS... A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT LAKES... WILL APPROACH THROUGH SUNDAY AND MAY STALL ACROSS THE REGION INTO EARLY NEXT WEEK. AS THE SYSTEM GETS CLOSER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE. THE BETTER CHANCES WILL BE FROM THE CAPITAL DISTRICT NORTH AND WEST ON SUNDAY...WITH MORE WIDESPREAD CHANCES MONDAY AND TUESDAY. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 112 AM EDT...ISOLATED TO WIDELY SCATTERED SHOWERS REMAIN WELL WEST OF OUR AREA AT THIS HOUR AND CONTINUING TO WEAKEN. THESE SHOWERS ARE AHEAD OF WEAK DISTURBANCE IN ADVANCE OF A COLD FRONT. LOCAL HI-RES WRF AND HRRR NOW INDICATING SHOWERS WILL NOT REACH OUR AREA THROUGH THE REST OF THE NIGHT EXCEPT FOR AN ISOLATED SHOWER OR TWO OVER THE WESTERN ADIRONDACKS. ALSO WE HAVE ADDED PATCHY FOG TO THE MID HUDSON VALLEY...NW CT...SE CATSKILLS AND SRN BERKSHIRES BTWN 06Z-12Z. THE LOW STRATUS CONTINUES TO FORM AND MOVE NORTH FROM THE LOWER TO MID HUDSON VALLEY AND SW NEW ENGLAND. EXPECT MOSTLY CLOUDY CONDITIONS FROM THE HUDSON RIVER VALLEY EASTWARD BY DAYBREAK. LOWS TONIGHT WILL BE VERY MILD FOR EARLY MAY IN THE MID 50S TO LOWER 60S ACROSS THE FCST AREA. THESE MINS ARE A GOOD 10 TO 15 DEGREES ABOVE NORMAL. A SOUTHERLY BREEZE WILL CONTINUE IN THE CAPITAL REGION WITH THE FUNNELING EFFECT UP THE HUDSON VALLEY. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... FOR SUNDAY THE COLD FRONT WILL DROP SOUTHWARD ACROSS THE NORTHERN HALF OF THE AREA DURING THE DAY. THERE WILL BE SCATTERED SHOWERS AND THUNDERSTORMS MAINLY NORTH AND WEST OF THE CAPITAL DISTRICT. THERE IS A STRONG THETA E RIDGE IN PLACE ACROSS THE REGION WITH CAPES OVER 1000 J/KG NORTH OF THE GREATER CAPITAL DISTRICT. UPPER LEVEL Q VECTOR DIVERGENCE IS WEAK AS ARE HELICITY VALUES WHICH ARE GENERALLY UNDER 100 M2/S2 SO NOT EXPECTING ANY SEVERE WEATHER ON SUNDAY. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE AS PWATS REACH ABOVE 1.50 INCHES ACROSS NORTHERN PORTIONS OF THE FA. HIGHS SUNDAY AFTERNOON ARE EXPECTED TO RANGE FROM THE UPPER 70S NORTHWEST TO MID 80S SOUTHEAST. DESPITE LOSS OF DAYTIME HEATING WILL CONTINUE CHANCES FOR SHOWERS AND THUNDERSTORMS SUNDAY NIGHT AS THE FRONTAL BOUNDARY WILL LIKELY STALL OVER THE AREA. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 50S TO MID 60S. BY MONDAY THE FRONTAL BOUNDARY SHOULD BE STALLED ACROSS THE CENTRAL PORTION OF OUR FA WITH A LOW PRESSURE SYSTEM MOVING EASTWARD ALONG IT. THIS SHOULD BRING THE FIRST WIDESPREAD RAINFALL TO OUR REGION IN NEARLY TWO WEEKS. THERE ARE SEVERAL KEY INGREDIENTS IN PLACE WHICH SHOULD PROMOTE THUNDERSTORM ACTIVITY IN ADDITION TO THE AFOREMENTIONED COLD FRONT. THERE WILL BE A STRONG THETA E RIDGE ACROSS THE REGION ESPECIALLY DURING THE AFTERNOON HOURS WHICH COUPLED WITH SB CAPES OF 500-1500 J/KG...PWATS 1.25 TO 1.75 INCHES AND 0-3 KM HELICITY OF 100-200 M2/S2. HIGHS ON MONDAY SHOULD BE IN THE UPPER 60S TO LOWER 80S. MONDAY NIGHT AND TUESDAY WILL CONTINUE TO BE VERY HUMID WITH HIGH PWAT VALUES AT LEAST THROUGH THE FIRST HALF OF TUESDAY. THE FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT LAKES EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY HOURS TO EARLY AFTERNOON AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA. SO THE BEST CHANCES FOR CONVECTION LOOK TO BE LATE MONDAY NIGHT THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT LOWS MONDAY NIGHT TO BE IN THE UPPER 50S TO MID 60S WITH HIGHS ON TUESDAY IN THE 70S TO AROUND 80. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... THE EXTENDED FORECAST FEATURES A RETURN TO MORE SEASONABLE TEMPS FOR MID MAY FROM THE MIDDLE OF THE WEEK INTO NEXT WEEKEND WITH MAINLY DRY WEATHER AFTER WEDNESDAY...AS A CANADIAN SFC HIGH BUILDS IN FOR THU INTO THE WEEKEND. TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE EAST OF THE REGION BY TUESDAY EVENING ACCORDING TO THE MEDIUM RANGE GUIDANCE /ECMWF...GFS...CAN GGEM/...AND MOST OF THE GEFS. HOWEVER...THE UPPER LEVEL TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING ACROSS MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW CHC OF SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN CATSKILLS...AND BERKSHIRES NORTHWARD. IT WILL BE MUCH COOLER BY WED MORNING WITH H850 TEMPS FALLING TO +1C TO +4C FROM NW TO SE ACROSS THE REGION...AND THIS IS BEFORE THE SFC TROUGH PASSAGE. THE COLD ADVECTION WILL CONTINUE ON WED...AS IT WILL BE BRISK AND COOL. LOWS WILL BE IN THE MID AND U40S OVER THE MTNS...AND LOWER TO MID 50S ACROSS THE VALLEY AREAS. HIGHS WED WILL BE SLIGHTLY BELOW NORMAL WITH U50S TO M60S IN THE VALLEY AREAS...AND U40S TO U50S OVER THE HIGHER TERRAIN. WED NIGHT INTO THU...THE TREND TO COOLER AND DRIER WEATHER CONTINUES...AS THE SHOWERS WILL END BY SUNSET. IN THE COLD ADVECTION REGIME THE GFS HAS H850 TEMPS LOWER TO -1C TO -4C OVER THE FCST AREA. THESE H850 TEMPS ARE 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL ACCORDING TO THE LATEST 12Z GEFS. THE SKIES WILL GRADUALLY CLEAR...AND THE WINDS WILL BE LIGHTER THAN THU. LOWS WILL BE IN THE 40-45F RANGE IN THE CAPITAL DISTRICT...MID HUDSON VALLEY...SRN TACONICS...ERN WINDHAM CTY VT...AND NW CT...AND MAINLY 30S ELSEWHERE OVER THE W-CNTRL MOHAWK VALLEY...ERN CATSKILLS...SRN DACKS REGION...LAKE GEORGE REGION...THE SRN GREENS AND BERKSHIRES. THERE SHOULD BE ENOUGH WIND TO PRECLUDE ANY FROST ISSUES THURSDAY MORNING WHERE THE GROWING SEASON HAS BEGIN. HIGHS ON THU WITH THE SFC HIGH BUILDING IN FROM THE GREAT LAKES REGION WILL BE INN THE LOWER TO MID 60S IN THE VALLEYS...AND 50S OVER THE HIGHER TERRAIN. THE SFC HIGH SHOULD HAVE PLENTY OF SUBSIDENCE WITH IT FOR MOSTLY SUNNY CONDITIONS. THU NIGHT INTO FRIDAY...THE SFC ANTICYCLONE BUILDS IN OVER THE NORTHEAST WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS. THIS WILL LIKELY BE THE COLDEST NIGHT WITH TEMPS IN THE U30S TO L40S IN THE VALLEY AREAS...AND LOWER TO M30S OVER THE HIGHER TERRAIN. SOME FROST ISSUES MAY ARISE IN A FEW SPOTS WHERE THE GROWING SEASON HAS BEGIN. BY FRIDAY AFTERNOON...THE SFC HIGH MOVES OFF THE THE MID ATLANTIC COAST...AND MID LEVEL HEIGHTS INCREASE OVER THE NORTHEAST. ANOTHER NICE DAY IS EXPECTED WITH TEMPS NUDGING SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE U60S TO L70S IN THE VALLEY AREAS...AND LOWER TO M60S OVER THE MTNS. FRI NIGHT INTO SATURDAY...THE FAIR WEATHER LOOKS TO CONTINUE INTO THE FIRST PART OF THE WEEKEND WITH THE MID-LEVEL RIDGE AXIS OVER NY AND NEW ENGLAND. A WEAK SYSTEM TRIES TO APPROACH FROM THE TN AND OH VALLEYS. MOST OF THE GUIDANCE KEEPS IT SOUTH AND WEST OF THE ALY FCST AREA. A SLIGHT CHC OF SHOWERS WAS ADDED TO THE ERN CATSKILLS/WRN MOHAWK VALLEY SAT PM...BUT OVERALL DRY WEATHER IS EXPECTED TO START THE WEEKEND WITH TEMPS SLIGHTLY ABOVE NORMAL. && .AVIATION /05Z SUNDAY THROUGH THURSDAY/... A COLD FRONT WILL BECOME STATIONARY NORTH OF THE ST LAWRENCE RIVER VALLEY TONIGHT WITH WEAK DISTURBANCES MOVING ALONG IT. THE FRONT WILL SLOWLY BEGIN TO SAG SOUTH TOMORROW WITH INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS ESPECIALLY NORTH OF THE MOHAWK RIVER VALLEY. THE FORECAST AREA WILL REMAIN IN A WARM SECTOR THROUGH THE DAY. IT WILL BE A WARM AND HUMID AIR MASS FOR MAY...AS LOW-LEVEL MOISTURE CONTINUES TO INCREASE IN THE BOUNDARY LAYER. THE LOW- LEVEL SOUTHERLY FLOW WILL SUPPORT LOW STRATUS AT ALL TAF SITES THROUGH SUNRISE. THE CEILING BETWEEN 1000-3000 FEET WILL OCCASIONALLY BE SCATTERED BUT PREDOMINANTLY BROKEN. THE CEILING SHOULD DEVELOP AT KALB BETWEEN 06Z-09Z. AFTER 09Z...A LAYER BELOW 1000 FEET COULD FORM...ESPECIALLY AT KPOU AND KPSF. PUTTING A SCATTERED LAYER BELOW 1000 FEET AT ALL TAF SITES BUT PUTTING INTERVALS OF A BROKEN CEILING BELOW 1000 FEET AT KPOU AND KPSF. CAN AMEND FOR KALB AND KGFL IF A CEILING BELOW 1000 FEET DEVELOPS THERE...WHICH IS LESS LIKELY THAN AT KPOU AND KPSF. VISIBILITIES SHOULD LOWER TO MVFR IN LIGHT MIST AS WINDS BECOME LIGHT...LESS THAN 5 KT AT ALL SITES EXCEPT KALB WHERE STEADY 6 TO 10 KT FROM THE SOUTH IS LIKELY THROUGH SUNRISE. AFTER ABOUT 13Z...ALL CEILINGS AND VISIBILITIES SHOULD BECOME VFR...BUT BROKEN CEILINGS ABOVE 3000 FEET ARE LIKELY AT ALL SITES THROUGH THE DAY...WITH PERIODS OF SCATTERED. SOME ISOLATED TO SCATTERED SHOWERS SHOULD BUILD INTO THE REGION THIS AFTERNOON AND EVENING...BUT AGAIN...COVERAGE SHOULD BE SCATTERED AT BEST...SO GOING VCSH AT KGFL...KALB AND KPSF. CONFIDENCE WAS NOT GREAT ENOUGH TO ADD THUNDER TO THE TAF SITES YET. THE WINDS WILL BE FROM THE SOUTH AT 5-12 KTS AT KALB...KGFL AND KPSF BUT 5 KT OR LESS AT KPOU. WINDS WILL BECOME LIGHT TO CALM AT KPSF/KGFL/KPOU...BUT DUE TO THE CHANNELING UP THE HUDSON RIVER VALLEY EXPECT SOUTHERLY WINDS OF 6 TO 10 KTS AT KALB THROUGH SUNRISE. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST TOMORROW AT 8-12 KTS WITH SOME GUSTS AROUND 20 KTS AT KALB. WINDS WILL DIMINISH TO 8 KT OR LESS THIS EVENING. OUTLOOK... SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. MONDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY-THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... HAVE ISSUED A SPS FOR BERKSHIRE AND LITCHFIELD COUNTIES FOR ELEVATED FIRE WEATHER POTENTIAL FOR SUNDAY. A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT LAKES...WILL APPROACH OUR REGION THROUGH SUNDAY AND MAY STALL ACROSS THE REGION INTO EARLY NEXT WEEK. AS THE SYSTEM GETS CLOSER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE. THE BETTER CHANCES WILL BE FROM THE CAPITAL DISTRICT NORTH AND WEST ON SUNDAY...WITH MORE WIDESPREAD CHANCES MONDAY AND TUESDAY. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS. RELATIVE HUMIDITIES WILL RISE TO 80 TO 100 PERCENT TONIGHT...FALL TO 35 TO 55 PERCENT ON SUNDAY...RISE TO 85 TO 100 PERCENT ON SUNDAY NIGHT AND FALL TO 45 TO 65 PERCENT ON MONDAY. WINDS WILL BE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TONIGHT AND SUNDAY...SOUTH 5 TO 10 MPH SUNDAY NIGHT AND SOUTH AROUND 5 MPH ON MONDAY. && .HYDROLOGY... DRY WEATHER LOOKS TO PERSIST THROUGH MUCH OF TONIGHT...WITH GRADUALLY INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS SPREADING SOUTH AND EAST FROM SUNDAY THROUGH EARLY NEXT WEEK AS A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH AND EVENTUALLY MOVE THROUGH. IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS. THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH THUNDERSTORMS...ALTHOUGH RAINFALL WILL BE BENEFICIAL IN MOST PLACES DUE TO VERY DRY ANTECEDENT GROUND CONDITIONS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...11/JPV NEAR TERM...JPV/WASULA SHORT TERM...11 LONG TERM...WASULA AVIATION...NAS FIRE WEATHER...11 HYDROLOGY...IAA/11/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
112 AM EDT SUN MAY 10 2015 .SYNOPSIS... A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT LAKES... WILL APPROACH THROUGH SUNDAY AND MAY STALL ACROSS THE REGION INTO EARLY NEXT WEEK. AS THE SYSTEM GETS CLOSER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE. THE BETTER CHANCES WILL BE FROM THE CAPITAL DISTRICT NORTH AND WEST ON SUNDAY...WITH MORE WIDESPREAD CHANCES MONDAY AND TUESDAY. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 112 AM EDT...ISOLATED TO WIDELY SCATTERED SHOWERS REMAIN WELL WEST OF OUR AREA AT THIS HOUR AND CONTINUING TO WEAKEN. THESE SHOWERS ARE AHEAD OF WEAK DISTURBANCE IN ADVANCE OF A COLD FRONT. LOCAL HI-RES WRF AND HRRR NOW INDICATING SHOWERS WILL NOT REACH OUR AREA THROUGH THE REST OF THE NIGHT EXCEPT FOR AN ISOLATED SHOWER OR TWO OVER THE WESTERN ADIRONDACKS. ALSO WE HAVE ADDED PATCHY FOG TO THE MID HUDSON VALLEY...NW CT...SE CATSKILLS AND SRN BERKSHIRES BTWN 06Z-12Z. THE LOW STRATUS CONTINUES TO FORM AND MOVE NORTH FROM THE LOWER TO MID HUDSON VALLEY AND SW NEW ENGLAND. EXPECT MOSTLY CLOUDY CONDITIONS FROM THE HUDSON RIVER VALLEY EASTWARD BY DAYBREAK. LOWS TONIGHT WILL BE VERY MILD FOR EARLY MAY IN THE MID 50S TO LOWER 60S ACROSS THE FCST AREA. THESE MINS ARE A GOOD 10 TO 15 DEGREES ABOVE NORMAL. A SOUTHERLY BREEZE WILL CONTINUE IN THE CAPITAL REGION WITH THE FUNNELING EFFECT UP THE HUDSON VALLEY. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/... FOR SUNDAY THE COLD FRONT WILL DROP SOUTHWARD ACROSS THE NORTHERN HALF OF THE AREA DURING THE DAY. THERE WILL BE SCATTERED SHOWERS AND THUNDERSTORMS MAINLY NORTH AND WEST OF THE CAPITAL DISTRICT. THERE IS A STRONG THETA E RIDGE IN PLACE ACROSS THE REGION WITH CAPES OVER 1000 J/KG NORTH OF THE GREATER CAPITAL DISTRICT. UPPER LEVEL Q VECTOR DIVERGENCE IS WEAK AS ARE HELICITY VALUES WHICH ARE GENERALLY UNDER 100 M2/S2 SO NOT EXPECTING ANY SEVERE WEATHER ON SUNDAY. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE AS PWATS REACH ABOVE 1.50 INCHES ACROSS NORTHERN PORTIONS OF THE FA. HIGHS SUNDAY AFTERNOON ARE EXPECTED TO RANGE FROM THE UPPER 70S NORTHWEST TO MID 80S SOUTHEAST. DESPITE LOSS OF DAYTIME HEATING WILL CONTINUE CHANCES FOR SHOWERS AND THUNDERSTORMS SUNDAY NIGHT AS THE FRONTAL BOUNDARY WILL LIKELY STALL OVER THE AREA. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 50S TO MID 60S. BY MONDAY THE FRONTAL BOUNDARY SHOULD BE STALLED ACROSS THE CENTRAL PORTION OF OUR FA WITH A LOW PRESSURE SYSTEM MOVING EASTWARD ALONG IT. THIS SHOULD BRING THE FIRST WIDESPREAD RAINFALL TO OUR REGION IN NEARLY TWO WEEKS. THERE ARE SEVERAL KEY INGREDIENTS IN PLACE WHICH SHOULD PROMOTE THUNDERSTORM ACTIVITY IN ADDITION TO THE AFOREMENTIONED COLD FRONT. THERE WILL BE A STRONG THETA E RIDGE ACROSS THE REGION ESPECIALLY DURING THE AFTERNOON HOURS WHICH COUPLED WITH SB CAPES OF 500-1500 J/KG...PWATS 1.25 TO 1.75 INCHES AND 0-3 KM HELICITY OF 100-200 M2/S2. HIGHS ON MONDAY SHOULD BE IN THE UPPER 60S TO LOWER 80S. MONDAY NIGHT AND TUESDAY WILL CONTINUE TO BE VERY HUMID WITH HIGH PWAT VALUES AT LEAST THROUGH THE FIRST HALF OF TUESDAY. THE FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT LAKES EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY HOURS TO EARLY AFTERNOON AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA. SO THE BEST CHANCES FOR CONVECTION LOOK TO BE LATE MONDAY NIGHT THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT LOWS MONDAY NIGHT TO BE IN THE UPPER 50S TO MID 60S WITH HIGHS ON TUESDAY IN THE 70S TO AROUND 80. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... THE EXTENDED FORECAST FEATURES A RETURN TO MORE SEASONABLE TEMPS FOR MID MAY FROM THE MIDDLE OF THE WEEK INTO NEXT WEEKEND WITH MAINLY DRY WEATHER AFTER WEDNESDAY...AS A CANADIAN SFC HIGH BUILDS IN FOR THU INTO THE WEEKEND. TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE EAST OF THE REGION BY TUESDAY EVENING ACCORDING TO THE MEDIUM RANGE GUIDANCE /ECMWF...GFS...CAN GGEM/...AND MOST OF THE GEFS. HOWEVER...THE UPPER LEVEL TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING ACROSS MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW CHC OF SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN CATSKILLS...AND BERKSHIRES NORTHWARD. IT WILL BE MUCH COOLER BY WED MORNING WITH H850 TEMPS FALLING TO +1C TO +4C FROM NW TO SE ACROSS THE REGION...AND THIS IS BEFORE THE SFC TROUGH PASSAGE. THE COLD ADVECTION WILL CONTINUE ON WED...AS IT WILL BE BRISK AND COOL. LOWS WILL BE IN THE MID AND U40S OVER THE MTNS...AND LOWER TO MID 50S ACROSS THE VALLEY AREAS. HIGHS WED WILL BE SLIGHTLY BELOW NORMAL WITH U50S TO M60S IN THE VALLEY AREAS...AND U40S TO U50S OVER THE HIGHER TERRAIN. WED NIGHT INTO THU...THE TREND TO COOLER AND DRIER WEATHER CONTINUES...AS THE SHOWERS WILL END BY SUNSET. IN THE COLD ADVECTION REGIME THE GFS HAS H850 TEMPS LOWER TO -1C TO -4C OVER THE FCST AREA. THESE H850 TEMPS ARE 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL ACCORDING TO THE LATEST 12Z GEFS. THE SKIES WILL GRADUALLY CLEAR...AND THE WINDS WILL BE LIGHTER THAN THU. LOWS WILL BE IN THE 40-45F RANGE IN THE CAPITAL DISTRICT...MID HUDSON VALLEY...SRN TACONICS...ERN WINDHAM CTY VT...AND NW CT...AND MAINLY 30S ELSEWHERE OVER THE W-CNTRL MOHAWK VALLEY...ERN CATSKILLS...SRN DACKS REGION...LAKE GEORGE REGION...THE SRN GREENS AND BERKSHIRES. THERE SHOULD BE ENOUGH WIND TO PRECLUDE ANY FROST ISSUES THURSDAY MORNING WHERE THE GROWING SEASON HAS BEGIN. HIGHS ON THU WITH THE SFC HIGH BUILDING IN FROM THE GREAT LAKES REGION WILL BE INN THE LOWER TO MID 60S IN THE VALLEYS...AND 50S OVER THE HIGHER TERRAIN. THE SFC HIGH SHOULD HAVE PLENTY OF SUBSIDENCE WITH IT FOR MOSTLY SUNNY CONDITIONS. THU NIGHT INTO FRIDAY...THE SFC ANTICYCLONE BUILDS IN OVER THE NORTHEAST WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS. THIS WILL LIKELY BE THE COLDEST NIGHT WITH TEMPS IN THE U30S TO L40S IN THE VALLEY AREAS...AND LOWER TO M30S OVER THE HIGHER TERRAIN. SOME FROST ISSUES MAY ARISE IN A FEW SPOTS WHERE THE GROWING SEASON HAS BEGIN. BY FRIDAY AFTERNOON...THE SFC HIGH MOVES OFF THE THE MID ATLANTIC COAST...AND MID LEVEL HEIGHTS INCREASE OVER THE NORTHEAST. ANOTHER NICE DAY IS EXPECTED WITH TEMPS NUDGING SLIGHTLY ABOVE NORMAL WITH HIGHS IN THE U60S TO L70S IN THE VALLEY AREAS...AND LOWER TO M60S OVER THE MTNS. FRI NIGHT INTO SATURDAY...THE FAIR WEATHER LOOKS TO CONTINUE INTO THE FIRST PART OF THE WEEKEND WITH THE MID-LEVEL RIDGE AXIS OVER NY AND NEW ENGLAND. A WEAK SYSTEM TRIES TO APPROACH FROM THE TN AND OH VALLEYS. MOST OF THE GUIDANCE KEEPS IT SOUTH AND WEST OF THE ALY FCST AREA. A SLIGHT CHC OF SHOWERS WAS ADDED TO THE ERN CATSKILLS/WRN MOHAWK VALLEY SAT PM...BUT OVERALL DRY WEATHER IS EXPECTED TO START THE WEEKEND WITH TEMPS SLIGHTLY ABOVE NORMAL. && .AVIATION /05Z SUNDAY THROUGH THURSDAY/... A COLD FRONT WILL BECOME STATIONARY NORTH OF THE ST LAWRENCE RIVER VALLEY TONIGHT WITH WEAK DISTURBANCES MOVING ALONG IT. THE FRONT WILL SLOWLY BEGIN TO SAG SOUTH TOMORROW WITH INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS ESPECIALLY NORTH OF THE MOHAWK RIVER VALLEY. THE FORECAST AREA WILL REMAIN IN A WARM SECTOR TONIGHT. IT WILL BE A WARM AND HUMID AIR MASS FOR MAY...AS LOW-LEVEL MOISTURE CONTINUES TO INCREASE IN THE BOUNDARY LAYER. THE LOW-LEVEL SOUTHERLY FLOW WILL ALLOW LOW STRATUS TO FORM FOR KPOU...KPSF...KGFL...AND KALB TONIGHT. THE LOW STRATUS IS EXPECTED TO FORM BTWN 03Z-06Z WITH MVFR CONDITIONS WITH CIGS BTWN 1-1.5 KFT AGL. EXPECT THE CIGS TO LOWER TO IFR LEVELS WITH SOME MIST AT KPOU AND KPSF PRIOR TO OR AROUND 06Z. THE IFR CIGS AND VSBYS WILL LAST UNTIL 12Z-15Z AT THESE SITES. IT IS TOUGH TO DISCERN IF KALB WILL HAVE IFR CIGS DUE TO A STEADY SOUTHERLY BREEZE UP THE HUDSON RIVER VALLEY...SO LOW MVFR CIGS WERE LEFT THERE. KGFL...THE WINDS ARE EXPECTED TO BECOME LIGHT TO CALM...AND IFR CIGS/VSBYS HAVE BEEN FORECASTED FROM 09Z-13Z. THE STRATUS WILL ERODE BELOW THE LOW-LEVEL INVERSION IN THE LATE MORNING WITH CIGS/VSBYS RISING BACK TO VFR LEVELS DUE TO SOME SUNSHINE AND MIXING. HOWEVER...MID CLOUDS WILL INCREASE AND THE THREAT FOR SOME SCT SHOWERS AND THUNDERSTORMS WELL IN ADVANCE OF THE COLD FRONT. VCSH GROUPS WERE ADDED TO KGFL/KALB/KPSF BTWN 18Z-21Z. OUR CONFIDENCE WAS NOT GREAT ENOUGH TO ADD THUNDER TO THE TAF SITES YET. THE WINDS WILL BE FROM THE SOUTH AT 5-12 KTS EARLY TONIGHT...AND THEY WILL BECOME LIGHT TO CALM AT KPSF/KGFL/KPOU...BUT DUE TO THE CHANNELING UP THE HUDSON RIVER VALLEY EXPECT SOUTHERLY WINDS OF AROUND 10 KTS AT KALB THROUGHOUT THE NIGHT. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST TOMORROW AT 8-12 KTS WITH SOME GUSTS AROUND 20 KTS AT KALB. OUTLOOK... SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. MONDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA. MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA. TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY-THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... HAVE ISSUED A SPS FOR BERKSHIRE AND LITCHFIELD COUNTIES FOR ELEVATED FIRE WEATHER POTENTIAL FOR SUNDAY. A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT LAKES...WILL APPROACH OUR REGION THROUGH SUNDAY AND MAY STALL ACROSS THE REGION INTO EARLY NEXT WEEK. AS THE SYSTEM GETS CLOSER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE. THE BETTER CHANCES WILL BE FROM THE CAPITAL DISTRICT NORTH AND WEST ON SUNDAY...WITH MORE WIDESPREAD CHANCES MONDAY AND TUESDAY. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS. RELATIVE HUMIDITIES WILL RISE TO 80 TO 100 PERCENT TONIGHT...FALL TO 35 TO 55 PERCENT ON SUNDAY...RISE TO 85 TO 100 PERCENT ON SUNDAY NIGHT AND FALL TO 45 TO 65 PERCENT ON MONDAY. WINDS WILL BE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TONIGHT AND SUNDAY...SOUTH 5 TO 10 MPH SUNDAY NIGHT AND SOUTH AROUND 5 MPH ON MONDAY. && .HYDROLOGY... DRY WEATHER LOOKS TO PERSIST THROUGH MUCH OF TONIGHT...WITH GRADUALLY INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS SPREADING SOUTH AND EAST FROM SUNDAY THROUGH EARLY NEXT WEEK AS A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH AND EVENTUALLY MOVE THROUGH. IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS. THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH THUNDERSTORMS...ALTHOUGH RAINFALL WILL BE BENEFICIAL IN MOST PLACES DUE TO VERY DRY ANTECEDENT GROUND CONDITIONS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...11/JPV NEAR TERM...JPV/WASULA SHORT TERM...11 LONG TERM...WASULA AVIATION...WASULA FIRE WEATHER...11 HYDROLOGY...IAA/11/JPV
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
950 AM EDT SUN MAY 10 2015 .DISCUSSION... TODAY...ANA WILL DRIFT NORTH ACROSS THE CAROLINAS...CONTINUING THE SLOW MIGRATION OF THE LOW LEVEL ATLANTIC RIDGE NORTHWARD. EARLY MORNING VISIBLE SATELLITE IMAGERY CLEARLY SHOWED CLOUD LINES DELINEATING THE RIDGE AXIS ACROSS THE NORTHERNMOST BAHAMAS. MORNING SOUNDINGS AND GPS PRECIPITABLE WATER DATA SHOWED MOISTENING AT MIAMI BUT DRIER AIR LINGERING FROM TAMPA TO OKEECHOBEE. THE GFS MOVES THIS DRIER RIBBON NORTHWARD AND INCREASES MOISTURE CONVERGENCE IN OUR SOUTHERN AREAS...WHILE DECREASING MOISTURE ACROSS THE NORTH. THEREFORE...EXPECT A SLIGHT CHANCE FOR STORMS ALONG THE INLAND MOVING SEA BREEZE FROM THE TREASURE COAST TO OKEECHOBEE AND SOUTH OSCEOLA. THIS FITS THE 12Z HRRR MODEL AND THE TYPICAL PATTERN OF HIGHER MOISTURE CONVERGENCE ZONE OCCURRING JUST NORTH OF THE RIDGE AXIS. ANY SHOWER/STORM CHANCES ACROSS THE NORTH WILL BE LATE AND WELL INLAND WITH THE EAST/WEST COAST SEA BREEZE COLLISION. WILL NOT CHANGE THE CURRENT FORECAST THAT DEPICTS LOW THRESHOLD POPS. TEMPS ALOFT ARE QUITE COOL THOUGH...SO WHERE THE GREATEST BOUNDARY COLLISIONS OCCUR...STRONG STORMS ARE POSSIBLE. && .AVIATION...MAINLY VFR. ONLY A SLIGHT CHANCE FOR STORMS MAINLY INLAND BETWEEN KMLB-KSUA AND PROBABLY SOUTH OF KMCO/KISM. LIGHT WIND REGIME...EXCEPT KMLB-KSUA WHERE THE SEA BREEZE SHOULD BE GUSTY TO NEAR 20 KNOTS. && .MARINE... TODAY-TONIGHT...ATLANTIC HIGH PRESSURE RIDGE AXIS WILL CONTINUE TO MIGRATE SLOWLY NORTHWARD FROM THE NORTHERN BAHAMAS. THIS WILL PRODUCE A SOUTHERLY WIND FLOW...MAINLY AROUND 10 KNOTS. DIURNAL INCREASES TO 15 KNOTS WILL OCCUR WITH THE SEA BREEZE NEAR SHORE AND OFFSHORE OVERNIGHT. SO OVERALL THERE WILL BE A LITTLE MORE WIND WAVE COMPARED TO THE LAST COUPLE DAYS. SMALL CHANCES FOR SHOWERS AND STORMS WILL EXIST ON ATLANTIC CLOUD LINES INTO TONIGHT. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ FORECASTS...LASCODY IMPACT WX...WEITLICH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1046 AM CDT SUN MAY 10 2015 .UPDATE... ISSUED AT 1045 AM CDT SUN MAY 10 2015 WILL UPDATE THE FORECAST LATE THIS MORNING FOR SOME ADJUSTMENT TO CHANCES OF SHOWERS AND THUNDERSTORMS REST OF THE DAY...AS CONVECTION AS BEEN MORE WIDELY SCATTERED THIS MORNING. ALSO HAVE LINGERING FOG OVER NORTHERN COUNTIES NORTH OF WARM FRONT AND LOCALLY DENSE THIS MORNING. THE WARM FRONT CURRENTLY WAS SLOWLY LIFTING NORTH AND WAS SOUTH OF MACOMB AND PEORIA AND JUST PASSED NORTH OF BLOOMINGTON AIRPORT A HALF HOUR AGO. THE FRONT WILL SLOWLY PUSH NORTH ACROSS NORTHERN COUNTIES THIS AFTERNOON AND THIS AREA WILL HAVE BEST CHANCES OF DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN WARM/HUMID AIRMASS. ANOTHER AREA OF CONVECTION WILL SPREAD NE ACROSS CENTRAL IL DURING THE EVENING. SPC CONTINUES SLIGHT RISK OF SEVERE STORMS LATER THIS AFTERNOON AND EVENING ACROSS MUCH OF CENTRAL IL ESPECIALLY FROM I-57 WEST WHERE CAPES GET TO 1500-2500 J/KG BY 00Z/7 PM CENTRAL AND WESTERN CWA AND BULK SHEAR TO 25-35 KTS WESTERN CWA BY SUNSET. HIGHS TO RANGE FROM LOW TO MID 70S FAR NORTHERN 3 COUNTIES OF KNOX...STARK AND MARSHALL... TO THE UPPER 70S AND LOWER 80S FROM PEORIA SOUTH. && .SHORT TERM...(TODAY) ISSUED AT 329 AM CDT SUN MAY 10 2015 SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF 10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI. GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON. BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS WILL TOP THE 80 DEGREE MARK. .LONG TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN MAY 10 2015 LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON. ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE 60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24 HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 600 AM CDT SUN MAY 10 2015 A WARM FRONT...CURRENTLY LOCATED FROM JUST NORTH OF KSPI AND KCMI WILL EDGE NORTHWARD TODAY WITH MOSTLY LIFR TO VLIFR CIGS AND VSBYS TO ITS NORTH...WHILE MVFR AND VFR CIGS WERE PREVALENT TO ITS SOUTH THIS MORNING. HOW QUICKLY THE CIGS AND VSBYS IMPROVE AS THE FRONT MOVES NORTH WILL BE THE PRIMARY CONCERN EARLY ON DURING THIS FORECAST PERIOD...WITH TIMING OF STRONG TO LOCALLY SEVERE STORMS AFTER 20Z THE NEXT CONCERN DURING THE SECOND HALF OF THE FORECAST PERIOD. WITH MOST OF THE SHORT TERM MODELS NOT PUSHING THE FRONT TO THE NORTH OF THE TAF SITES BY EARLY THIS AFTERNOON...WILL BRING CIGS AND VSBYS UP IN THE AREAS NORTH OF THE FRONT THIS MORNING WHILE MVFR TO LOW VFR CIGS EXPECTED OVER THE REMAINDER OF THE TAF SITES THIS AFTERNOON. BASED ON THE LATEST SOUNDING DATA... IT APPEARS BASES WILL IMPROVE TO SCT-BKN CIGS FROM AROUND 2500-3500 FEET BY EARLY THIS AFTERNOON. CONVECTION LOOKS TO DEVELOP OVER PARTS OF CENTRAL AND SOUTH CENTRAL MISSOURI BY THIS AFTERNOON AND PUSH EAST AND NORTHEAST INTO OUR FORECAST AREA BETWEEN 21Z AND 00Z AND LAST THRU ABOUT 05Z BEFORE TAPERING OFF TO SHOWERS FOR THE REMAINDER OF THE TIME PERIOD. SURFACE WINDS WILL BE EASTERLY AT 5 TO 12 KTS NORTH OF THE WARM FRONT FOR THE NEXT SEVERAL HOURS...BUT MOST AREAS SHOULD SEE SOUTH TO SOUTHEAST WINDS AT 10 TO 15 KTS TODAY WITH SOUTHEASTERLY FLOW EXPECTED TONIGHT AT 8 TO 15 KTS...WHICH SHOULD BECOME SOUTH LATE TONIGHT AT 12 TO 17 KTS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...BARNES LONG TERM...BARNES AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
605 AM CDT SUN MAY 10 2015 .SHORT TERM...(TODAY) ISSUED AT 329 AM CDT SUN MAY 10 2015 SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF 10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI. GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON. BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS WILL TOP THE 80 DEGREE MARK. .LONG TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN MAY 10 2015 LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON. ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE 60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24 HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 600 AM CDT SUN MAY 10 2015 A WARM FRONT...CURRENTLY LOCATED FROM JUST NORTH OF KSPI AND KCMI WILL EDGE NORTHWARD TODAY WITH MOSTLY LIFR TO VLIFR CIGS AND VSBYS TO ITS NORTH...WHILE MVFR AND VFR CIGS WERE PREVALENT TO ITS SOUTH THIS MORNING. HOW QUICKLY THE CIGS AND VSBYS IMPROVE AS THE FRONT MOVES NORTH WILL BE THE PRIMARY CONCERN EARLY ON DURING THIS FORECAST PERIOD...WITH TIMING OF STRONG TO LOCALLY SEVERE STORMS AFTER 20Z THE NEXT CONCERN DURING THE SECOND HALF OF THE FORECAST PERIOD. WITH MOST OF THE SHORT TERM MODELS NOT PUSHING THE FRONT TO THE NORTH OF THE TAF SITES BY EARLY THIS AFTERNOON...WILL BRING CIGS AND VSBYS UP IN THE AREAS NORTH OF THE FRONT THIS MORNING WHILE MVFR TO LOW VFR CIGS EXPECTED OVER THE REMAINDER OF THE TAF SITES THIS AFTERNOON. BASED ON THE LATEST SOUNDING DATA... IT APPEARS BASES WILL IMPROVE TO SCT-BKN CIGS FROM AROUND 2500-3500 FEET BY EARLY THIS AFTERNOON. CONVECTION LOOKS TO DEVELOP OVER PARTS OF CENTRAL AND SOUTH CENTRAL MISSOURI BY THIS AFTERNOON AND PUSH EAST AND NORTHEAST INTO OUR FORECAST AREA BETWEEN 21Z AND 00Z AND LAST THRU ABOUT 05Z BEFORE TAPERING OFF TO SHOWERS FOR THE REMAINDER OF THE TIME PERIOD. SURFACE WINDS WILL BE EASTERLY AT 5 TO 12 KTS NORTH OF THE WARM FRONT FOR THE NEXT SEVERAL HOURS...BUT MOST AREAS SHOULD SEE SOUTH TO SOUTHEAST WINDS AT 10 TO 15 KTS TODAY WITH SOUTHEASTERLY FLOW EXPECTED TONIGHT AT 8 TO 15 KTS...WHICH SHOULD BECOME SOUTH LATE TONIGHT AT 12 TO 17 KTS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARNES LONG TERM...BARNES AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
329 AM CDT SUN MAY 10 2015 .SHORT TERM...(TODAY) ISSUED AT 329 AM CDT SUN MAY 10 2015 SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF 10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI. GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON. BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS WILL TOP THE 80 DEGREE MARK. && .LONG TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 329 AM CDT SUN MAY 10 2015 LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON. ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE 60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24 HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1200 AM CDT SUN MAY 10 2015 SCATTERED SHOWERS WILL CONTINUE OVERNIGHT THROUGH ALL TAFS, SO WILL KEEP VCSH AT ALL TAFS THROUGH MORNING HOURS. AREA OF CONVECTION IN OK/ARK/SRN MO WILL MOVE ENE ACROSS SOUTHERN IL OVERNIGHT AND SHOULD REMAIN SOUTH OF THE TAFS. COULD BE SOME LINGERING SHOWERS REACH UP INTO THE AREA, BUT WILL NOT INCLUDE ANYTHING FOR NOW. MORE PCPN IS POSSIBLE TONIGHT SO WILL HAVE VCTS IN TAFS STARTING LATE AFTERNOON THROUGH EVENING HOURS. NOT SURE WHEN A TEMPO GROUP FOR THUNDERSTORMS IS WARRANTED SO WILL LEAVE OUT FOR NOW. IFR CONDITIONS HAVE MOVED INTO THE AREA AT ALL SITES AND WILL LIKELY CONTINUE OVERNIGHT. THEN BY MORNING CIGS WILL IMPROVE INTO THE MVFR CATEGORY. BY EVENING WHEN THE STORMS WILL BE AROUND, VFR CONDITIONS WILL PREVAIL. WINDS WILL BE NORTHEAST AT PIA/BMI WHICH ARE NORTH OF THE FRONT FOR NOW. SOUTH TO SOUTHEAST WINDS WILL PREVAIL AT SPI/DEC/CMI. PIA AND BMI WILL SEE WINDS BECOME SOUTHERLY DURING THE AFTERNOON/EVENING AS THE FRONT LIFTS NORTH OF THE SITES. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARNES LONG TERM...BARNES AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1200 AM CDT SUN MAY 10 2015 .UPDATE... ISSUED AT 901 PM CDT SAT MAY 9 2015 SCATTERED SHOWERS CONTINUE ACROSS THE AREA THIS EVENING AND WITH REMNANTS OF ANOTHER MCS COMING IN FOR LATER TONIGHT...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE OVERNIGHT. SKIES WILL REMAIN MOSTLY CLOUDY SO DO NOT THINK MUCH FOG WILL OCCUR LATE TONIGHT LIKE LAST NIGHT. CLOUDS WILL KEEP TEMPS UP AS WELL AND CURRENT FORECAST LOW LOOKS FINE. GIVEN RADAR TRENDS HAVE MADE SOME ADJUSTMENTS TO THE POP/WX GRIDS. SO UPDATE WILL BE COMING SHORTLY. && .SHORT TERM...(TONIGHT) ISSUED AT 251 PM CDT SAT MAY 9 2015 A QUASI-STATIONARY FRONTAL BOUNDARY FROM JUST SOUTH OF ST LOUIS AND FLORA TO TERRE HAUTE WILL SLOWLY LIFT BACK NORTH AS A WARM FRONT TOWARD I-72 TONIGHT (STAYING SOUTH OF I-72 TONIGHT). AREA OF SHOWERS AND THUNDERSTORMS WITH SOME HEAVY RAIN WAS ALONG AND SOUTH OF A TAYLORVILLE TO MATTOON TO PARIS LINE AND LIFTING SLOWLY NORTHWARD. THIS ASSOCIATED WITH MCV EAST OF ST LOUIS AND SLOWLY TRACKING NNE INTO SW IL AT MID AFTERNOON. SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHWARD ACROSS CENTRAL IL LATE THIS AFTERNOON AND EVENING WHILE BECOMING MORE SCATTERED IN SOUTHEAST IL AS THEY GET INTO THE WARM SECTOR. TAIL END OF HRRR MODEL AND RAP13 MODEL SHOW MORE CONVECTION SPREADING NE INTO SW CWA LATER TONIGHT AHEAD OF YET ANOTHER MCV OVER EASTERN OK. SPC KEEPS MARGINAL RISK OF SEVERE STORMS SW OF IL OVER MO THROUGH TONIGHT. A FEW STRONGER THUNDERSTORMS COULD HAVE WIND GUSTS OVER 40 MPH WITH PEA SIZE HAIL AND HEAVY RAINS NEAR 1 INCH IN LESS THAN AN HOUR. LOWS TONIGHT RANGE FROM UPPER 50S TO AROUND 60F NORTH OF LINCOLN TO THE MID 60S FROM JACKSONVILLE AND SPRINGFIELD TO MATTOON SOUTH. .LONG TERM...(SUNDAY THROUGH SATURDAY) ISSUED AT 251 PM CDT SAT MAY 9 2015 UNSETTLED AND UNSEASONABLY MILD WEATHER PATTERN WILL PERSIST ACROSS CENTRAL AND SOUTHEAST ILLINOIS THROUGH MONDAY. STILL A COUPLE MORE WAVES IN THE PERSISTENT SOUTHWESTERLY FLOW ALOFT NEED TO MOVE THROUGH THE AREA BEFORE THE VIGOROUS CUT-OFF UPPER LOW OVER THE FOUR CORNERS REGION FINALLY DRIVES A COLD FRONT THROUGH THE AREA. THIS FRONT WILL BE FOLLOWED BY COOLER & DRIER AIR FOR MUCH OF THE WORK WEEK. SUNDAY SHOULD START OUT WITH SHOWERS/STORMS ACROSS MUCH OF THE REGION AS A DISTURBANCE, CURRENTLY PRODUCING VIGOROUS CONVECTION ACROSS THE SOUTHERN PLAINS, TRACKS NORTHEAST ACROSS THE AREA. DO NOT EXPECT THE MORNING STORMS TO BE SEVERE. THEN, ATTENTION TO THE UPPER AND ASSOCIATED SURFACE LOW THAT WILL BE PICKING UP STEAM AS IT TRACK NORTHEAST ACROSS THE PLAINS. A WARM FRONT EXTENDING SOUTHEAST FROM THE LOW ACROSS THE MIDWEST WILL LIFT NORTH THROUGH THE DAY. STILL SOME SIGNIFICANT MODEL DISAGREEMENT WITH RESPECT TO HOW QUICKLY THE FRONT LIFTS NORTHWARD. THE POSITION OF THIS FRONT DURING PEAK HEATING WILL BE KEY TO WHERE THE BEST SEVERE WEATHER THREAT WILL EXIST. AT THIS POINT, IT APPEARS THE BEST SHEAR/INSTABILITY WILL CO- EXIST ACROSS THE NORTHERN PORTION OF THE FORECAST AREA INTO NORTHERN ILLINOIS. THE SHEAR PROFILES WILL BE SUBSTANTIALLY MORE IMPRESSIVE FURTHER NORTHWEST, ACROSS IOWA, CLOSER TO THE TRACK OF THE UPPER/SURFACE LOW. THE LOWS WILL TRACK ACROSS THE GREAT LAKES ON MONDAY DRAGGING THE TRAILING COLD FRONT THROUGH ILLINOIS. STILL SOME MODEL DISAGREEMENT IN THE SPEED OF THE COLD FRONT, WHICH WILL BE KEY TO THE SEVERE WEATHER THREAT ON MONDAY. THE NAM, WHICH HAD BEEN THE QUICKEST MODEL, IS NOW AMONG THE SLOWEST SOLUTIONS. CONTINUE TO FAVOR A SLOWER SOLUTION GIVEN THE CURRENT POSITION/SPEED OF THE SYSTEM OVER THE SOUTHWEST STATES, AND A TYPICAL MODEL BIAS OF BEING TOO QUICK MOVING CUT-OFF LOWS. THESE FACTORS CONSIDERED, IT APPEARS THAT THE BEST THREAT FOR SEVERE WEATHER ON MONDAY LOCALLY IS ACROSS EAST CENTRAL AND SOUTHEAST ILLINOIS DURING THE MONDAY AFTERNOON/EARLY EVENING HOURS. QUIETER AND COOLER WEATHER IS EXPECTED TO ARRIVE MONDAY NIGHT AND LINGER FOR MUCH OF THE REMAINDER OF THE WEEK. DAYTIME HIGHS THAT HAD FREQUENTLY BEEN IN THE 80S AHEAD OF THE FRONT WILL MAINLY BE IN THE 60S AFTER FRONTAL PASSAGE. THE ECMWF, WHILE SLOWER THAN IT WAS A COUPLE DAYS AGO, IS STILL THE QUICKEST TO BRING A SYSTEM BACK INTO THE AREA BY THE END OF THE WEEK AS SOUTHWEST UPPER-LEVEL FLOW REDEVELOPS AND TEMPERATURES TEND TO CLIMB BACK TOWARD NORMAL. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1200 AM CDT SUN MAY 10 2015 SCATTERED SHOWERS WILL CONTINUE OVERNIGHT THROUGH ALL TAFS, SO WILL KEEP VCSH AT ALL TAFS THROUGH MORNING HOURS. AREA OF CONVECTION IN OK/ARK/SRN MO WILL MOVE ENE ACROSS SOUTHERN IL OVERNIGHT AND SHOULD REMAIN SOUTH OF THE TAFS. COULD BE SOME LINGERING SHOWERS REACH UP INTO THE AREA, BUT WILL NOT INCLUDE ANYTHING FOR NOW. MORE PCPN IS POSSIBLE TONIGHT SO WILL HAVE VCTS IN TAFS STARTING LATE AFTERNOON THROUGH EVENING HOURS. NOT SURE WHEN A TEMPO GROUP FOR THUNDERSTORMS IS WARRANTED SO WILL LEAVE OUT FOR NOW. IFR CONDITIONS HAVE MOVED INTO THE AREA AT ALL SITES AND WILL LIKELY CONTINUE OVERNIGHT. THEN BY MORNING CIGS WILL IMPROVE INTO THE MVFR CATEGORY. BY EVENING WHEN THE STORMS WILL BE AROUND, VFR CONDITIONS WILL PREVAIL. WINDS WILL BE NORTHEAST AT PIA/BMI WHICH ARE NORTH OF THE FRONT FOR NOW. SOUTH TO SOUTHEAST WINDS WILL PREVAIL AT SPI/DEC/CMI. PIA AND BMI WILL SEE WINDS BECOME SOUTHERLY DURING THE AFTERNOON/EVENING AS THE FRONT LIFTS NORTH OF THE SITES. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AUTEN SHORT TERM...07 LONG TERM...BAK AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1137 PM CDT SAT MAY 9 2015 .SHORT TERM /TONIGHT/... ISSUED AT 355 PM CDT SAT MAY 9 2015 QUIET FOR THE REST OF SATURDAY AND THEN STORM CHANCES ENTER THE FCST LATE IN THIS SHORT TERM PERIOD. A POCKET OF DRIER AIR HAS BEEN IN PLACE MOST OF SATURDAY AFTERNOON ACROSS THE CWA ALLOWING FOR SUNSHINE TO PUNCH THROUGH ACROSS THE CENTRAL TO NORTHERN PARTS OF OUR CWA. THE LARGE AREA OF LOW PRESSURE WE HAVE BEEN TALKING ABOUT FOR THE PAST FEW DAYS HAS REACHED THE FOUR CORNERS REGION OF THE CONUS. THIS LOW IS SLATED TO BE LOCATED OVER WESTERN NEBRASKA BY 12Z SUN. THE NAM IS A SLIGHT OUTLIER...KEEPING THIS SYSTEM SLOWER AND FURTHER TO THE SOUTH THAN THE REST OF GUIDANCE. THE GFS IS THE FASTEST. LEANED TOWARDS THE EURO...WHICH IS IN THE MIDDLE...FOR TIMING. FOR LOW LEVEL MOISTURE INIT...USUAL MODEL BIASES IN PLACE. THE NAM IS THE MOST MOIST...WHILE THE GFS IS OVERLY DRY. LEANED TOWARDS EURO ONCE AGAIN. AHEAD OF THIS AREA OF LOW PRESSURE...A WARM FRONT WILL BE PASSING THROUGH OUR CWA FROM SW TO NE. ALL MODELS SHOW THE GULF IS WIDE OPEN FOR MOISTURE TRANSPORT VIA THE LLJ...THE NOSE OF WHICH WILL BE ALONG THE WESTERN/CENTRAL PART OF OUR CWA AT 12Z SUN. REGARDING THE SEVERE WEATHER POTENTIAL...THE RAP SHOWS 0-1KM BULK SHEAR VALUES IN THE 20 TO 25KT RANGE...HELICITY IN THE 200 TO 400 RANGE AND LOW ENOUGH LCL HEIGHTS TO SUGGEST TORNADOES MAY BE A SEVERE MODE THREAT EARLY ON. DCAPE VALUES ARE ALSO HIGH EARLY ON...SO DAMAGING WINDS IS ALSO A THREAT. LOCATION-WISE...THIS WILL MAINLY BE IN THE WESTERN/SW CWA AT 12Z. THE EVOLUTION OF SUNDAY/S SEVERE WEATHER WILL BE HANDLED IN THE LONG TERM. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 355 PM CDT SAT MAY 9 2015 MAIN FORECAST CONCERN WAS FOCUSED ON SEVERE WEATHER POTENTIAL FOR SUNDAY INTO SUNDAY NIGHT. THE REMAINDER OF THE FORECAST TIME FRAME REMAINS RELATIVELY QUIET UNTIL LATE IN THE WORK WEEK. SUNDAY INTO SUNDAY NIGHT...POTENTIAL EXISTS FOR AT LEAST TWO ROUNDS OF SEVERE WEATHER ON MOTHERS DAY...WITH THE MORNING CONVECTION SURGING NORTHWARD WITH THE WARM FRONT THROUGH 15Z AND THEN THE DIURNALLY DRIVEN CONVECTION IN THE AFTERNOON ALONG THE DRY LINE BY THE LATE AFTERNOON/EARLY EVENING. LEANED TOWARD THE NAM12/ARWWRF FOR TIMING OF POPS SUNDAY INTO SUNDAY NIGHT EVEN THOUGH MODELS ARE IN FAIRLY GOOD AGREEMENT WRT TO SURFACE LOW TRACK AND TIMING OF COLD FROPA SUNDAY EVENING. THIS RESULTED IN DELAYING THE AFTERNOON CONVECTION SLIGHTLY AS INITIATION LOOKS TO BE AFTER 20Z SUNDAY OVER WESTERN PORTIONS OF THE FORECAST AREA. THE WARM FRONT LOOKS TO SURGE NORTHWARD TO THE IOWA/MINNESOTA BORDER BY AROUND 00Z MONDAY WITH THE SURFACE LOW CENTERED OVER FAR NORTHWEST CORNER OF IOWA AND FAR SOUTHEAST SOUTH DAKOTA. THE STRONGER AND DEEPER FORCING FOR ASCENT IS IN THIS LOCATION BUT QUESTIONABLE WHETHER SURFACE INSTABILITY RECOVERS ENOUGH TO SUPPORT LOW-LIVED TORNADIC SUPERCELLS. HOWEVER...ENOUGH ELEVATED MUCAPE PRESENT COMBINED WITH STRONG LOW LEVEL SHEAR AND VORTICITY WITHIN THE VICINITY OF THE WARM FRONT LOOKS TO COUNTERACT THE LACK OF SURFACE INSTABILITY AND CERTAINLY PROVIDE A DECENT THREAT FOR TORNADOES AND LARGE HAIL OVER WEST-CENTRAL TO NORTH-CENTRAL IOWA TOMORROW AFTERNOON. DEEP LAYER SHEAR FROM 50 TO NEAR 70 KNOTS PLENTY STRONG ENOUGH TO KEEP CONVECTION THROUGH THE EVENING SUNDAY AS THE COLD FRONT PUSHES ACROSS IOWA. SEVERE POTENTIAL EXISTS ALONG THE COLD FRONT WITH STRAIGHT-LINE WINDS THROUGH ROUGHLY 03Z MONDAY BEFORE ENVIRONMENT BECOMES LESS FAVORABLE. THINKING ANY SUPERCELLS THAT DEVELOP LATE TOMORROW AFTERNOON WILL MORPH INTO A QLCS TYPE STRUCTURE WITH THE ADVANCEMENT OF THE COLD FRONT...WHICH WOULD KEEP THE ROUNDS OF SEVERE WEATHER AT ONLY TWO. IF CONVECTION PUSHES NORTH INTO MINNESOTA THEN A THIRD ROUND ALONG THE COLD FRONT SEEMS FEASIBLE TOMORROW EVENING WITHIN THE DMX CWA. MONDAY THROUGH WEDNESDAY...STRONG CAA DEVELOPS ON MONDAY INTO MONDAY NIGHT AND MAY SEE A FEW SHOWERS ACROSS THE NORTH WITH SOME WRAP-AROUND MOISTURE FROM THE SURFACE LOW. OTHERWISE...COOL AND DRY CONDITIONS THROUGH WEDNESDAY. THURSDAY INTO SATURDAY...LARGE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN WITH A FAIRLY STRONG VORT MAX EJECTING OUT OF THE SOUTHERN ROCKIES THURSDAY. UNCERTAINTY IN TIMING WITH THE ECMWF ROUGHLY 12 HOURS QUICKER THAN THE GFS. BY THE END OF THE WORK WEEK AND INTO NEXT WEEKEND...THE REGION IS PLACED BACK INTO SOUTHWEST FLOW ALOFT AND EXTENDED MODELS HAVE MULTIPLE SHORTWAVES TO AFFECT THE FORECAST AREA. && .AVIATION...10/06Z ISSUED AT 1136 PM CDT SAT MAY 9 2015 LATEST DATA SHOWS LITTLE CHANGE FROM PREVIOUS THINKING. STORMS WILL FORM OVER NEBRASKA/WESTERN IA AND MOVE NORTH NORTHEAST OVERNIGHT WITH POTENTIAL FOR SOME THUNDER AFT 09-10Z FOR KFOD AND KDSM...LESSER CHANCES NOW FOR KALO|KOTM|KMCW OTHER THAN POSSIBLE SHRA THROUGH 18Z AS INSTABILITY WILL WEAKEN FARTHER NORTH OVERNIGHT AND EARLY SUNDAY. BREAK IN STORMS EXPECTED WEST/SOUTH AFT 14-15Z SUN. CONDITIONS REMAIN LOW MVFR TO PERHAPS IFR NORTH FOR MOST OF DAY...ELSEWHERE MVFR. RAP40 SHOWS POTENTIAL FOR SOME TSRA REDEVELOPMENT AS EARLY AS 18Z SOUTHWEST/WEST WITH MAIN LINE MOVING ACROSS AREA FROM 20|21Z THROUGH 06Z EAST AS DRY LINE IS FORCED THROUGH THE AREA. BEST CHANCE FOR STRONG TO SVR STORMS WILL BE WITH AFTERNOON PASSAGE OF DRY LINE. SOME LINGERING -SHRA AND SW WINDS EXPECTED AFT 00Z. /REV && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KOTENBERG LONG TERM...PODRAZIK AVIATION...REV
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1154 PM CDT Sat May 9 2015 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Sunday) Issued at 322 PM CDT SAT MAY 9 2015 An intense upper level trough was located across northwest NM. An 80 KT H5 jet max was lifting northeast across west TX into southwest KS. A dryline was sharpening up from southeast CO, south-southeast across the eastern TX PNHDL, then south into the hill country of west central TX. The center of a lee cyclone, north of TAD. The warm front extended east south-southeast from the lee cyclone, across southwest KS, then east along the KS and OK border. A band of elevated thunderstorms that formed across southeast CO and the TX PNHDL earlier this morning continues to slowly move northeast across central and south central KS. The area of elevated thunderstorms were beginning to weaken as they move northeast into a more stable airmass across eastern KS. An MCS was forming across central OK and will move east-northeast across northeast OK into southwest MO. The CWA will see a gradual increase in isolated to scattered shower and thunderstorms late this afternoon, but with MUCAPES only 500 to 1000 J/KG these storms will not become severe this afternoon. As the warm front begins to push north, the isentropic lift will begin to weaken and we may see a break in the shower and thunderstorms activity through the mid evening hours. Farther west, the atmosphere is beginning to recover from the morning convection across the eastern TX PNHDL, eastern CO and western KS. As the upper low over northwest NM lifts northeast into east-central CO, numerous thunderstorms should develop along the dryline as it begins to push northeast across the eastern TX PNHDL into southwest KS and east central CO. Intense upper level ascent ahead of the lifting upper low will allow scattered supercell thunderstorms across western KS to congeal into a QLCS or an MCS through the evening hours across western KS. This storm complex will lift northeast across north central KS late this evening and through the early morning hours of Sunday. If a complex of thunderstorms develop the primary hazards will be large hail, damaging winds and heavy rain. The meso-scale models such as the RAP and WRF move the more intense portions of the MCS north-northeast into southern NE just west of the CWA. Though, there may be enough ascent that scattered thunderstorms will develop south-southeast of this complex of thunderstorms. The primary hazard of any severe thunderstorms across the CWA later Tonight will be large hail, damaging wind gusts and heavy rainfall. The vertical wind shear and MUCAPE do increase later Tonight, thus if a supercell thunderstorm develops the boundary layer may not be decoupled enough to prevent isolated tornadoes. However, at this time the better chances for tornadic supercells will be this evening across western KS. Due to the uncertainty in the intensity and areal extent of wide spread deep moist convection, I will not be issuing a flash flood watch for the CWA. There is a chance for locally heavy rainfall with any convective complex that develops. The isolated to scattered thunderstorms later Tonight will move quickly to the northeast, so expect only brief heavy rainfall. The better chances for heavy rainfall will be associated with MCS`s that are forecasted to move southeast and northwest of the CWA. Sunday, there may be a few morning storms across the eastern counties of the CWA. The upper low will begin to slowly fill as it lifts northeast-northeast into western NE during the day. A strong H5 jet max of 50 to 60 KTS will over spread eastern KS through the afternoon hours. A cold front will quickly occlude the dryline across central KS during the mid and late morning hours and the cold front will push east across the western half of the CWA during the early Afternoon hours. The numerical models all show the 850mb winds slowly veering to the southwest ahead of the surface front. However, the numerical models forecast southerly or even southeasterly surface wind ahead of the surface front. The deepest gulf moisture may get shunted eastward across MO into eastern IA but several mesoscale models are showing 10 to 12 DEG Td at 850mb remaining ahead of the surface front. There should be enough deep moisture and instability for scattered thunderstorms to begin to develop along the surface cold front by 20Z. The front should extend roughly from a Seneca to Manhattan to Council Grove line by 3 PM. Thunderstorms that develop will rapidly become severe given MLCAPES of 1500 to 2500 J/KG and SFC to 6KM effective shear of 50 to 60 KTS. Even though 850mb winds begin to veer slightly the surface winds may remain back. Therefore as storms first form they may be isolated to scattered supercells before congealing into a squall line which will then push east across northeast and east central KS during the late afternoon hours. The 0-1 SRH of 150 to 250 J/KG may support any discrete supercell to produce isolated tornadoes. Once the isolated to scattered supercells merge into a squall line then the primary hazards will be damaging winds gusts, large hail and heavy rainfall. The line will move fairly fast across the eastern counties of the CWA and begin to weaken after 6 PM due to the loss of surface heating. Highs just behind the surface front across the central counties of the CWA may reach to around 80 degrees, with most other areas getting into the mid to upper 70s. .LONG TERM...(Sunday Night through Saturday) Issued at 322 PM CDT SAT MAY 9 2015 Sunday Night through Monday Night ... By Sunday evening, models are in fairly good agreement with the surface and mid-level patterns. A closed mid-level low should be centered over the northern High Plains with the deep trough stretching all the way southward toward the U.S./Mexico border. At the surface, the center of low pressure should be focused across northeast Nebraska with the associated cold front extending southward and essentially bisecting the forecast area (i.e., stretching from Marysville to Manhattan to Herington by early evening). This front placement is a bit further west than what models were suggesting yesterday. Model soundings show little to no inhibition in place across the area by late afternoon/early evening. Expect decent advection of warm, moist air ahead of this boundary from the breezy southerly winds, resulting in a decent set-up for some strong to severe thunderstorms late afternoon into the evening hours. Models suggest that isolated storms should develop along and ahead of the cold front by late afternoon/early evening and quickly congeal into a line of storms as the wind profiles look to prevail out of the southwest. With a north/south oriented boundary, this southwesterly flow should help to advance this line of storms fairly quickly eastward across eastern KS with most of the forecast area dry by midnight. Increasing low-level cloud cover combined with little inhibition may result in slightly lower CAPE values upwards of 1500-1800J/kg. Wind profiles show fairly unidirectional winds out of the southwest with a 60-70kt 500mb jet, however there are some discrepancies with regards to how much winds will veer in the lowest 2km of the atmosphere. As a result, there is a notable range amongst the models in 0-1km helicity values across far eastern Kansas. LCL values should be fairly low at around 3000ft or less, but the lapse rates do not look that great. With these conditions and model discrepancies in mind, confidence is low in the tornado threat across eastern Kansas Sunday evening however an isolated tornado or two still cannot be ruled out. Expect upwards of 50-60kts of 0-6km shear, so combined with the modest instability the primary severe threats look to be large hail and strong winds. Some locally heavy rainfall will also be possible, which may potentially result in some localized flash flooding and/or river flooding as some locations have already received a few inches of rain this week. However, with 1-hr and 3-hr flash flood guidance near 2 inches, do not expect widespread flooding concerns with these fast-moving storms. Winds will slowly veer toward the west overnight into Monday morning with clearing skies. As a result, decent radiational cooling should help to drop low temperatures into the 40s. The mid-level trough will lift northward out of the area through the day on Monday with surface high pressure advancing into the High Plains behind this exiting system. West-northwesterly surface winds will usher cooler air into the region, keeping Monday high temperatures below normal in the low/mid 60s. These cool conditions and mostly clear skies will persist into Monday night with even cooler overnight low temperatures in the upper 30s to mid 40s. Tuesday through Saturday... Tuesday will have mostly sunny skies and highs in the upper 60s, with lows dropping into the upper 40s Tuesday night. The surface high pressure aiding in these mild conditions will move southeast of the area late evening, allowing winds to veer to the south by Wednesday morning. This warm air advection will push highs into the lower 70s, before another system pushes into the area bringing chances for precipitation every day for the rest of the period. Models are still inconsistent with the handling this next system, but agree with the previous forecast that the ECMWF solution seems more reasonable. An upper-level wave will move NE into the central plains by late Thursday bringing the best chances for thunderstorms Wednesday night though Thursday night. Severe potential is still low as the best CAPE/shear seems to be south or west of our area, depending on the model. From here, thunderstorm chances remain until Saturday, but confidence in timing and the overall pattern are low. && .AVIATION...(For the 06Z TAFs through 06Z Sunday Night) Issued at 1153 PM CDT SAT MAY 9 2015 MVFR stratus lingering in the area and trends suggest more persistent and lower cigs are likely through the next several hours. Weak inversion should keep stratus in place through 15-17Z. Caveat continues to be convection chances. At least some chance remains even well ahead of dryline as moisture streams north but again confidence too low for any early inclusion. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gargan LONG TERM...Heller/Hennecke AVIATION...65
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
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~18-20KT THIS EVENING...HAVE PLACED SCEC FOR ALL ZONES THRU 4 AM. BY THIS TIME...GRADIENT EXPECTED TO RELAX AS FRONT SAGS FURTHER S TOWARDS THE COASTAL WATERS BY DAYBREAK. DML PREV DISCUSSION... /ISSUED 653 PM CDT MON MAY 11 2015/ DISCUSSION... FOR THE 00Z TAF PACKAGE. AVIATION... CONSIDERABLE CONVECTION OCCURRING OVER THE NW GULF WATERS ALONG AND BEHIND AN EXTENSIVE OUTFLOW BOUNDARY THAT PUSHED THROUGH THE AREA EARLIER TODAY. LGT TO MDT STRATIFORM TYPE RAIN CONTINUES TO OCCASIONALLY STREAK ACROSS THE ACADIANA TERMINALS. ALL SITES CURRENTLY VFR WITH MAINLY MID/HIGH LEVEL CLOUD COVER. CURRENT MODEL DATA APPEARS TO BE GROSSLY UNDERDOING THE CONVECTION TO OUR SOUTH...AND THUS HAVE LITTLE CONFIDENCE IN SOLUTIONS WHICH DEVELOP ADDITIONAL ACTIVITY FARTHER NORTH EITHER LATE THIS EVENING OR DURING THE OVERNIGHT HOURS. REGIONAL RADAR DOES APPEAR TO SHOW A BIT OF A NWD PUSH TO CONVECTION NEAR THE MIDDLE TX COAST...SO TRENDS WILL CONTINUE TO BE MONITORED. FOR NOW WILL CARRY PREVAILING VFR...WITH SCATTERED LOW CLOUDS WORKING BACK IN DURING THE OVERNIGHT/MORNING HRS. 13 PREV DISCUSSION... /ISSUED 413 PM CDT MON MAY 11 2015/ SYNOPSIS... ACTIVE SUBTROP JET CONTINUES TO BRING MOISTURE OVER THE REGION. A SERIES OF IMPULSES EMBEDDED IN THE SWLY FLOW ALOFT HAVE AIDED IN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS...WITH ADDITIONAL SUPPORT FM AN OUTFLOW BOUNDARY CROSSING THE CWA TODAY. LATEST RADAR MOSAIC SHOWS A BAND OF CONVECTION CONTINUES TO PROPAGATE SOUTH AND EAST ACRS THE LOWER MS VALLEY AND OVER OUR COASTAL WATERS ZONES...WITH ADDITIONAL ACTIVITY FURTHER WEST ACRS SE AND SRN TX. THERE WAS A SHORT PERIOD THIS MORNING PRIOR TO THE ARRIVAL OF THE CONVECTION WHEN TEMPERATURES ACRS THE SRN ZONES CLIMBED INTO THE LOWER 80S...BUT THESE QUICKLY FELL WITH THE PASSAGE OF THE OUTFLOW BOUNDARY AND TEMPERATURES HAVE BEEN HELD IN CHECK FOR MUCH OF THE DAY...RANGING FROM THE MIDDLE 60S ACRS ACADIANA TO THE LOWER TO MIDDLE 70S ACRS SE TX AS OF 3 PM. DISCUSSION... A COLD FRONT...CURRENTLY EXTENDING FM NEAR KTXK TO KATT...WILL MOVE INTO THE AREA OVERNIGHT WHILE ALOFT ANOTHER IMPULSE UPSTREAM OVER NRN MEXICO WILL CROSS TX. EXPECT A BRIEF BREAK IN CONVECTION DURING THE EVENING...WITH SHOWER AND TSTM CHCS INCREASING FM THE WEST AGAIN OVERNIGHT. CONVECTION WILL INCREASE ACRS THE AREA DURING THE DAY TUESDAY...WITH THE SFC FRONT SERVING AS A FOCUS. SOME STORMS COULD BE STRONG OR MARGINALLY SVR...GIVEN THAT SUFFICIENT DESTABILIZATION CAN OCCUR WITH DAYTIME HEATING...WITH ISLTD STRONG DAMAGING WINDS OR MARGINALLY SVR HAIL THE MAIN THREATS. ALSO...WITH ABUNDANT MOISTURE OVER THE REGION...ABV NORMAL PRECIP WATER VALUES BETWEEN 1.5 AND 1.8 INCHES...STORMS WILL ALSO BE CAPABLE OF PRODUCING HEAVY RAINFALL AND LOCALIZED FLOODING COULD BE AN ISSUE. HIGH TEMPERATURES ON TUESDAY ARE EXPECTED TO REACH THE LOWER 80S...BUT THIS WILL ALSO BE DEPENDENT ON WHETHER THERE WILL BE ENOUGH BREAKS IN THE CLOUDS TO ALLOW WARMING DURING THE DAY. THROUGH THE REMAINDER OF THE WEEK...THE PATTERN ALOFT WILL CHANGE LITTLE WITH SWLY FLOW PERSISTING BETWEEN A MEAN TROF OVER THE WRN CONUS AND A RIDGE OVER THE ERN CONUS. A SERIES OF SHORTWAVE TROFS WILL EJECT NE OVER THE CNTL PLAINS...AND INTERACT WITH THE MOIST AND UNSTABLE AIRMASS OVER THE REGION LEADING TO AT LEAST A DAILY CHC FOR SHOWERS OR TSTMS. AT THE SFC...HIGH PRES WILL MIGRATE TOWARD THE EAST COAST...WITH SELY FLOW RESUMING BY WEDNESDAY. WARM AND MUGGY CONDITIONS ARE EXPECTED TO PERSIST...WITH TEMPERATURES RUNNING NEAR CLIMATOLOGICAL NORMS. 24 MARINE... WINDS WILL BECOME ELY TONIGHT INTO TUESDAY AS A WEAK FRONT MOVES INTO THE REGION AND BECOMES STALLED ALONG SE TX AND SW LA COAST. ONSHORE FLOW WILL RESUME BY WEDNESDAY MORNING AS HIGH PRES MIGRATES TOWARD THE EAST AND THE FRONT SLOWLY LIFTS BACK TO THE NORTH OVER THE REGION. A LT TO MDT ONSHORE FLOW WILL THEN PERSIST THROUGH NEXT WEEKEND. 24 && .PRELIMINARY POINT TEMPS/POPS... AEX 66 80 66 83 / 50 50 30 30 LCH 70 83 70 82 / 40 60 30 30 LFT 70 84 70 84 / 50 50 30 30 BPT 70 82 71 82 / 40 60 30 30 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...COASTAL FLOOD ADVISORY UNTIL 4 AM CDT TUESDAY FOR LAZ073-074. TX...COASTAL FLOOD ADVISORY UNTIL 4 AM CDT TUESDAY FOR TXZ215. GM...SMALL CRAFT EXERCISE CAUTION UNTIL 4 AM CDT TUESDAY FOR GMZ435- 455-475. SMALL CRAFT ADVISORY UNTIL 4 AM CDT TUESDAY FOR GMZ430-432-450- 452-470-472. && $$ PUBLIC...08
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
753 PM EDT MON MAY 11 2015 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 328 PM EDT MON MAY 11 2015 A COLD FRONT WILL COME THROUGH THE AREA TONIGHT ENDING OVER A WEEKS WORTH OF UNSEASONABLY WARM TEMPERATURES. THERE WILL BE SHOWERS AND A FEW THUNDERSTORMS AHEAD OF THE COLD FRONT THIS EVENING...THEN A FEW LIGHT RAIN SHOWERS TUESDAY AS CHILLY WESTERLY WINDS KEEP AFTERNOON TEMPERATURES IN THE 50S. SKIES WILL BECOME PARTLY CLOUDY TUESDAY NIGHT REMAIN SO ON WEDNESDAY. ANOTHER STORM SYSTEM WILL BRING MORE SHOWERS AND POSSIBLY THUNDERSTORMS LATER THIS WEEK INTO THE WEEKEND. IT WILL WARM UP AGAIN BY THE END TOO. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 328 PM EDT MON MAY 11 2015 THE MAIN ISSUE IS THE THREAT FOR SEVERE STORMS (NOT MUCH) THEN THE CHANCE FOR LIGHT RAIN SHOWERS TUESDAY AND POSSIBLE FROST TOMORROW NIGHT. THE LATEST RAP MODEL SHOWS THE LOW LEVEL JET CORE LIFTING NORTHEAST FROM SOUTHWEST LOWER MICHIGAN EARLY THIS AFTERNOON TO THE THUMB AREA BY EARLY THIS EVENING. THE MOST UNSTABLE CAPE (OVER 500 J/KG) STAYS JUST EAST OF OUR CWA LATE THIS AFTERNOON. WHILE THERE IS GOOD DEEP LAYER SHEAR...THE RAIN COOLED AIR OVER MOST OF OUR CWA WILL MITIGATE MOST OF THE SEVERE WEATHER THREAT. POSSIBLY ISOLATED DAMAGING WINDS COULD HAPPEN OVER OUR EXTREME SOUTHEAST COUNTIES EARLY THIS EVENING. OTHERWISE THE AREA OF RAIN WILL MOVE OUT BY MID EVENING. THEN THE DRY SLOT MOVES IN BEHIND THE COLD FRONT SO SKIES WILL CLEAR AT LEAST PARTLY. WE THEN GET WRAP AROUND COLD AIR ADVECTION INSTABILITY SHOWERS (MOSTLY SPRINKLES) TUESDAY AND IT WILL BE BREEZY AND CHILLY WITH HIGHS ONLY IN THE 50S. THE UPPER TROUGH MOVES OUT QUICKLY TUESDAY NIGHT ALLOWING FOR SOME CLEARING. FROST IS POSSIBLE OVER NORTHERN AREAS WEDNESDAY MORNING. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 328 PM EDT MON MAY 11 2015 AS HIGH PRESSURE MOVES EAST THURSDAY LOW PRESSURE WILL MOVE TOWARD THE GREAT LAKES. CONFIDENCE IS INCREASING THAT WE/LL SEE SOME PRECIPITATION MOVE OVER THE CWA THURSDAY NIGHT AND FRIDAY. ADDED THUNDER TO THE GRIDS FRIDAY AS LI/S FALL TO AROUND -2C AND CAPE INCREASES TO 1K J/KG. MUCH OF THE PCPN WILL BE EAST OF THE CWA BY SATURDAY AS THE SFC LOW MOVES AWAY. HOWEVER WE/LL KEEP LOW POPS IN TO COVER THE UPPER TROUGH. CHANCES FOR TSRA WILL INCREASE TOWARD THE BEGINNING OF NEXT WEEK AS A STRONGER COLD FRONT MOVES TOWARD THE CWA. STRONG SOUTH FLOW AHEAD OF IT WILL SEND ABUNDANT MOISTURE NORTHWARD AND CREATE SOME INSTABILITY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 752 PM EDT MON MAY 11 2015 PREDOMINATELY MVFR CIGS AND SCTD RAIN SHOWERS EARLY THIS EVENING WILL GIVE WAY TO MOSTLY VFR CIGS AFTER 02Z AS DRIER AIR SWEEPS IN BEHIND A COLD FRONT. THERE IS CURRENTLY SOME FOG OVER LAKE MICHIGAN AND THIS WILL RESULT IN OCNL IFR CONDITIONS AT MKG FOR A COUPLE MORE HOURS THIS EVENING. THE THREAT OF TSTMS HAS ENDED. AROUND 12Z TUESDAY MORE MVFR CIGS WILL SPREAD IN FROM THE WEST AND PERSIST MUCH OF THE DAY. A FEW LIGHT SHOWERS ARE POSSIBLE BUT IF ANY REDUCTIONS TO VSBYS OCCURRED IT SHOULD BE VERY BRIEF. GUSTY SOUTHWEST TO WEST SFC WINDS OF 15 TO 25 KNOTS TONIGHT WILL INCREASE TO 20 TO 30 KNOTS ON TUESDAY... RESULTING IN SOME LOW LEVEL TURBULENCE. && .MARINE... ISSUED AT 328 PM EDT MON MAY 11 2015 THE STRONG WINDS BEHIND OUR SYSTEM WILL LEAD TO 4 TO 6 FOOT WAVES AND WINDS TO 30 KNOTS BY MID MORNING TUESDAY. AS A RESULT I ISSUED A SMALL CRAFT ADVISORY. && .HYDROLOGY... ISSUED AT 1222 PM EDT MON MAY 11 2015 ADDITIONAL RAINFALL AMOUNTS BETWEEN A QUARTER AND THREE QUARTERS OF AN INCH WILL BE POSSIBLE MAINLY BEFORE MIDNIGHT TONIGHT. WE ARE ISSUING ADVISORIES FOR THE SYCAMORE CREEK AT HOLT...WHICH SHOULD CREST SHORTLY AFTER MIDNIGHT TONIGHT. CONFIDENCE IS HIGH THAT IT WILL REMAIN BELOW FLOOD STAGE. AFTER TONIGHT DRY CONDITIONS SHOULD PREVAIL UNTIL THURSDAY...WHEN RAIN SHOWERS RETURN TO THE AREA. THIS SHOULD GIVE RIVER LEVELS SOME TIME TO SUBSIDE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY FROM 5 AM TO 6 PM EDT TUESDAY FOR LMZ844>849. && $$ SYNOPSIS...WDM SHORT TERM...WDM LONG TERM...93 AVIATION...MEADE HYDROLOGY...TJT MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
751 PM EDT MON MAY 11 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 421 PM EDT MON MAY 11 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE MID LEVEL LOW THAT WAS OVER WRN NEBRASKA/SD 24HRS AGO NOW CENTERED IN WCNTRL MN. AHEAD OF FEATURE...WARM CONVEYOR BELT MOISTURE RIBBON EXTENDS FROM THE LWR MISSISSIPPI VALLEY TO THE WRN GREAT LAKES. RESULT HAS BEEN NMRS SHRA SPREADING ACROSS THE FCST AREA TODAY. A FEW TSTMS WERE NOTED THIS MORNING OVER THE W HALF OF UPPER MI. AT THE SFC...LOW PRES LOCATED IN CNTRL MN IS BECOMING LESS WELL-DEFINED WITH TENDENCY FOR LOW PRES REDEVELOPMENT AT THE TRIPLE POINT FARTHER E. OCCLUDED FRONT IS APPROACHING THE MI/WI BORDER AS OF 20Z. AS THE WARM CONVEYOR MOISTURE RIBBON TRANSLATES E...WIDESPREAD SHRA NOW OVER THE E HALF OF THE FCST AREA WILL ALSO SHIFT E AND OUT OF THE AREA IN THE NEXT FEW HRS. FOG AND SOME -DZ WILL PERSIST IN THE UPSLOPE FLOW OFF LAKE SUPERIOR INTO THE KEWEENAW AND WRN PORTIONS OF NCNTRL UPPER MI...AND A FEW SHRA MAY DEVELOP NEAR THE OCCLUDED FRONT WHICH SHOULD LIFT INTO OR THRU MUCH OF CNTRL AND ERN UPPER MI THIS EVENING. OTHERWISE...AS MID LEVEL LOW OPENS UP AND UPPER TROF MOVES E INTO THE WRN GREAT LAKES TONIGHT...DEEPER MOISTURE WILL WRAP BACK INTO THE AREA FROM THE N AND W. AIDED BY DEEP CYCLONIC FLOW...SHRA WILL SPREAD BACK INTO THE FCST AREA...ESPECIALLY ACROSS THE W. AS CAA INCREASES OVERNIGHT...FCST SOUNDINGS/WETBULB ZERO HEIGHTS SUGGEST POTENTIAL FOR SNOW TO MIX WITH THE RAIN OVER THE HIGH TERRAIN OF THE W LATE TONIGHT. AS TROF CONTINUES TO SHIFT E TUE...DEEP LAYER QVECTOR DIVERGENCE OVERSPREADS THE AREA WITH HEIGHTS BEGINNING TO RISE...MORE SUBSTANTIALLY IN THE AFTN. THIS WILL TEND TO DIMINISH THE WRAP AROUND PCPN WITH TIME...BUT THIS WILL BE COUNTERACTED BY SHARP CYCLONIC FLOW AND CONSIDERABLE LOW TO MID LEVEL MOISTURE THAT LINGERS THRU THE DAY. THIS WILL RESULT IN PCPN BEING MOST PERSISTENT IN THE AREAS THAT SEE UPSLOPING UNDER NW TO N WINDS. DOWNSLOPE AREAS WILL SEE PCPN DIMINISH OR END. CONTINUED CAA WILL DROP 850MB TEMPS TO -3 TO AS LOW AS -6C...AND THIS WILL RESULT IN RAIN MIXING WITH SNOW...MAINLY OVER THE HIGHER TERRAIN OF THE W AND CNTRL. PCPN WILL LIKELY CHANGE TO ALL SNOW AT LEAST FOR A TIME OVER THE HIGH TERRAIN OF THE W HALF AS LOWEST 850MB TEMPS ARE FCST THERE. THAT AREA WILL ALSO HAVE THE BEST CHANCE FOR A LITTLE SNOW ACCUMULATION ON GRASSY SFCS. IT WILL BE AN UNSEASONABLY COLD DAY WITH TEMPS AROUND 20 DEGREES BLO NORMAL ACROSS THE W AND N WHERE TEMPS WILL STRUGGLE TO GET MUCH ABOVE 40F. ACROSS THE SCNTRL...TEMPS MAY SNEAK INTO THE LWR 50S. BLUSTERY WINDS WILL ADD TO THE CHILL. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 255 PM EDT MON MAY 11 2015 WILL STILL HAVE SOME LINGERING MAINLY SNOW SHOWERS /WITH A FEW RAIN SHOWERS OR AREAS OF DRIZZLE MIXED IN/ TUESDAY NIGHT OVER THE N HALF OF UPPER MI. THE BEST CHANCE OF PRECIP WILL BE N CENTRAL AS FAVORABLE N-NNW WINDS RESIDE THERE FROM THE SFC-850MB. TEMPERATURES WILL BE COOLING INTO THE LOW 30S OVERNIGHT...WITH LOCATIONS OVER THE INTERIOR W HALF FALLING INTO THE MID 20S AS WINDS BECOME NEARLY CALM AND DRIER AIR WORKS IN AND 850MB TEMPS BEGIN TO WARM SLIGHTLY FROM - 4 TO -6C...TO AROUND -3C. HIGH PRESSURE WILL BE STRETCHING FROM HUDSON BAY THROUGH MANITOBA AND MN...DOWN THROUGH THE MS VALLEY AT 00Z WEDNESDAY. LOOK FOR THE AREA OF HIGH PRESSURE TO BUILD ACROSS THE UPPER GREAT LAKES THROUGH WEDNESDAY...WITH DRY WEATHER FIGURED INTO AT LEAST WEDNESDAY EVENING. WAA WILL TAKE HOLD AT THE SFC ON MAINLY S WINDS OVER THE W HALF OF THE CWA...WITH AFTERNOON HIGHS IN THE 50S FOR MOST LOCATIONS /EXCLUDING THE COOLER N CENTRAL AND E LAKE SUPERIOR SHORELINE/ AS 850MB TEMPS REBOUND TO AROUND 4C W TO 1C E. PRECIP COULD SLIDE IN AS EARLY AS LATE WEDNESDAY AFTERNOON SW /GFS SOLUTION/. THIS WOULD BE ALONG THE SW AS AN INITIAL FRONTAL BOUNDARY SHIFTS TO OUR N. THE MAIN CONCERN IS THAT THE LOWER LEVELS WILL BE TOO DRY WITH THE SFC RIDGE STILL OVER MUCH OF THE AREA WITH THIS BOUNDARY/SHORTWAVE ROUNDING THE 500MB RIDGE. WILL CONTINUE TO GO WITH A MINIMAL PRECIP SOLUTION FOR THIS PERIOD. THE SFC HIGH WILL SHIFT ACROSS THE ENTIRE GREAT LAKES REGION WEDNESDAY NIGHT...WITH SLOWLY INCREASING S FLOW OVER UPPER MI PUSHING IN INCREASED MOISTURE AS 850MB TEMPS RUMP TO AROUND 8C OVER THE SW. THE APEX OF THE 500MB RIDGE WILL BE ACROSS THE AREA THURSDAY AFTERNOON...WITH FCST MODELS INDICATING A NEARING EMBEDDED 500MB TROUGH IN THE SW FLOW OVER THE N PLAINS AND W MN. THE GFS HAS A DEEPER/WRAPPED UP SFC LOW OVER THE CENTRAL PLAINS OFF THE GFS IS NOT QUITE A S STRONG AS THE ECMWF...ESPECIALLY THE PREVIOUS 11/06Z RUN. THIS LEADS TO ONLY MODERATE CONFIDENCE IN THE FCST BEYOND THURSDAY. THE DIFFERENCE SHOWS UP WELL IN THE MODEL QPF...WITH THE 11/06Z GFS SHOWING 24HR PRECIP OF 0.75-1.45IN BY 00Z SATURDAY. THE 11/00Z ECMWF ON THE OTHER HAND RANGES FROM LESS THAN 0.10IN ACROSS THE KEWEENAW PENINSULA...TO 0.5IN OVER FAR S MENOMINEE CO. THIS WILL BE AS THE SFC LOW OFF THE GFS TRACKS FROM THE CENTRAL PLAINS TO N LAKE MI BY 00Z SATURDAY. THE CANADIAN THE ECMWF KEEP A RIDGE ACROSS LAKE SUPERIOR AND MUCH OF UPPER MI DURING THE SAME TIME PERIOD. ON A POSITIVE NOTE...THE 11/12Z GFS CAME IN AT LEAST A LITTLE LESS INTENSE WITH THE SFC LOW...AND DROPS ABOUT 1/2 AS MUCH PRECIP. AN ADDITIONAL LOW DEVELOPING OFF THE N ROCKIES TOWARDS THE END OF THE WORK WEEK WILL LIKELY BE SET UP ACROSS MT AND WY SATURDAY MORNING...AND MOVE ACROSS THE DAKOTAS SATURDAY NIGHT...AND THE UPPER GREAT LAKES ON MONDAY. THE 12Z RUNS HAVE BECOME MUCH MORE IN LINE WITH THE SFC LOW TRACKING OVER E MN/FAR W LAKE SUPERIOR BY 06Z MONDAY. THE RESULT IS AT LEAST MODERATE CONFIDENCE IN RAIN. WILL GO WITH LIKELY PRECIP FOR SUNDAY NIGHT ACROSS MOST OF THE CWA. SO FOR THE UPCOMING WEEKEND IT LOOKS TO BE MAINLY DRY SATURDAY...WITH WET WEATHER APPROACHING SUNDAY AND POSSIBLY LINGERING INTO MONDAY AS THE SFC LOW SLOWLY EDGES E OF THE CWA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 740 PM EDT MON MAY 11 2015 A LOW PRES SYSTEM WILL MOVE E ACROSS THE UPPER GREAT LAKES TONIGHT AND THEN E TO QUEBEC TUE. ABUNDANT LOW-LEVEL MOISTURE WILL GENERALLY SUPPORT IFR TO LIFR CONDITIONS AND -SHRA AT KIWD/KCMX/KSAW THRU THIS FCST PERIOD WITH THE LOWEST CONDITIONS OCCURRING AT TERMINALS EXPERIENCING UPSLOPE WINDS. THE LOWEST CONDITIONS (VLIFR) THIS EVENING WILL OCCUR AT KCMX UNDER UPSLOPE WESTERLY WINDS. SLIGHTLY DRIER AIR WORKING N THRU WI MAY REACH KIWD AND KSAW FOR A TIME THIS EVENING ALLOWING FOR A PERIOD OF MVFR CONDITIONS. THIS IS MORE LIKELY TO HAPPEN AT KSAW. COLDER AIR WRAPPING INTO THE AREA BEHIND THE LOW SHOULD BE COLD ENOUGH TO RESULT IN -SHRA MIXING WITH OR CHANGING OVER TO -SHSN TUE MORNING. CHANGE OVER TO ALL SNOW IS MORE LIKELY TO OCCUR AT KIWD/KCMX. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 421 PM EDT MON MAY 11 2015 ONGOING MARGINAL GALES OVER THE WRN PORTION OF LAKE SUPERIOR WILL CONTINUE TO DIMINISH...FALLING BLO GALE FORCE EARLY THIS EVENING... AS PRES GRADIENT WEAKENS AND WINDS BACK DUE TO LOW PRES SHIFTING ACROSS UPPER MI AND ERN LAKE SUPERIOR. ON THE BACK SIDE OF THE LOW...NNW WINDS WILL INCREASE TO 20-30KT ACROSS CNTRL AND ERN LAKE SUPERIOR LATE TONIGHT/TUE MORNING. MAY SEE A FEW GALE FORCE GUSTS TUE MORNING OVER SCNTRL LAKE SUPERIOR AROUND GRANITE ISLAND DUE TO LOCAL COASTAL CONVERGENCE. WINDS WILL DIMINISH FROM W TO E TUE AFTN/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS E AND A WEAK LOW PRES PASSES BY TO THE S...WINDS MAY INCREASE SOME FOR THU NIGHT/FRI BEFORE DIMINISHING AGAIN ON SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162- 263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT SUN MAY 10 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 417 PM EDT SUN MAY 10 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE WELL-DEFINED MID LEVEL LOW THAT WAS OVER THE SRN ROCKIES YESTERDAY NOW LIFTING N ACROSS WRN NEBRASKA/WRN SD. ONE WEAK LEAD SHORTWAVE THAT WAS OVER THE SRN PLAINS YESTERDAY HAS MOVED NE THRU LWR MI TODAY...SPREADING SHRA AND A FEW TSRA ACROSS LWR MI. CLOSER TO HOME...WEBCAMS INDICATED SOME PATCHY -DZ THIS MORNING OVER ERN PARTS OF THE FCST AREA AS LOW CLOUDS SPREAD BACK INTO MUCH OF UPPER MI. OTHERWISE...NO PCPN HAS OCCURRED TODAY. CLOUDS HAVE DOMINATED MOST OF THE FCST AREA. HOWEVER...MUCH OF THE WRN FCST AREA HAS BECOME MOSTLY SUNNY RECENTLY AS THE LOW CLOUDS HAVE DISSIPATED IN THAT AREA. TONIGHT AND MON...MID LEVEL LOW MOVING INTO SD WILL GRADUALLY OPEN UP AS IT DRIFTS INTO MN. ON THIS TRACK...THE STRONGEST DEEP LAYER FORCING (SHOWN NICELY BY QVECTORS) AND STRONGEST ISENTROPIC ASCENT WILL FOCUS INTO NRN MN. FARTHER E...A WEAKER EASTWARD EXTENSION OF DEEP LAYER FORCING COMBINED WITH A RIBBON OF REASONABLY STRONG ISENTROPIC ASCENT LIFTING NE ACROSS THE AREA SHOULD SUPPORT A PERIOD OF SHRA...MAINLY LATE TONIGHT THRU MON MORNING. THERE IS VERY LITTLE TO NO INSTABILITY NOTED ACCOMPANYING THIS BAND OF FORCING/SHRA...SO THUNDER POTENTIAL IS VERY LIMITED. WILL MAINTAIN A SCHC MENTION ONLY OVER THE FAR SCNTRL...CLOSER TO SOMEWHAT BETTER ELEVATED INSTABILITY TO THE S. MID LEVEL DRYING PUSHES INTO THE FCST AREA DURING THE DAY MON...FOLLOWING THE RIBBON OF ISENTROPIC ASCENT. THIS SHOULD RESULT IN A TRANSITION TO MAINLY DRY WEATHER OVER MOST OF THE AREA. BETTER CHC OF LINGERING ISOLD/SCT -SHRA IN THE AFTN WILL BE OVER THE N AND E. THAT SAID...SEEMS MORE LIKELY THAT WHERE UPSLOPE FLOW PERSISTS... LINGERING LOW-LEVEL MOISTURE MAY RESULT IN SOME -DZ AND UPSLOPE FOG...MAINLY ACROSS THE KEWEENAW AND NCNTRL UPPER MI. COMBINATION OF RAIN AND HIGHER DWPTS SPREADING N OVER LAKE MI WILL LIKELY MEAN FOG SPREADING UP LAKE MI AND AFFECTING AREAS MAINLY E OF KESC AS WELL. LATER IN THE AFTN...BROADENING SFC LOW/OCCLUDED FRONT MAY SLIP INTO THE SRN FCST AREA. GFS/NAM SHOW SOME LOW-LEVEL INSTABILITY (FEW HUNDRED J/KG) NEAR THIS FEATURE. COULD SPARK ISOLD TSRA LATE...BUT CONFIDENCE IN THAT OCCURRING IS VERY LOW. AS FOR TEMPS...THERE IS BIG BUST POTENTIAL WITH MAX TEMPS ON MON. IF THE OCCLUDED FRONT LIFTS INTO SRN UPPER MI AND CLOUDS BREAK...TEMPS COULD QUICKLY RISE WELL INTO THE 60S. SOME OF THE BIAS CORRECTED GUIDANCE HAS MAX TEMPS UP AROUND 70F NEAR THE MI/WI BORDER. FOR NOW...HAVE MAX TEMPS NEAR 60F OVER THE SCNTRL. TO THE N...WHERE FLOW REMAINS UPSLOPE OFF LAKE SUPERIOR...TEMPS SHOULD NOT RISE HIGHER THAN THE LWR 40S. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 248 PM EDT SUN MAY 10 2015 MUCH OF THIS PERIOD WILL BE COOL...WITH TEMPERATURES ONLY RETURNING TO NEAR NORMAL FOR DAYTIME HIGHS FOR FRIDAY FOR MONDAY NIGHT WE WILL START OFF WITH THE 500MB LOW SET UP ACROSS MN. THE 500MB LOW WILL BECOME AN OPEN WAVE OVERNIGHT AS IT MOVES OVER LAKE SUPERIOR AND EXITS TO THE NE TUESDAY. AT THE SFC...THE LOW WILL BE ACROSS THE S HALF OF THE CWA AT 00Z TUESDAY...SHIFTING TO THE E HALF BY 06Z...AND EXITING NE WITH A TROUGH LINGERING ACROSS UPPER MI THROUGH MUCH OF THE DAY TUESDAY. COULD WE HAVE SIGNIFICANT SNOW TUESDAY WITH THE HELP OF FAVORABLE UPSLOPE WINDS OFF LAKE SUPERIOR BEHIND THE EXITING SFC LOW? WHILE FCST MODELS ARE INDICATING 0-3IN OF SNOW MAINLY DURING THE DAY TUESDAY...THERE ARE A FEW NEGATIVES TO ANY SIGNIFICANT SNOW THAT COULD POSE A THREAT TO COMMERCE. THE NAM AND GFS DO SHOW A NOSE OF WARMER AIR BETWEEN 750MB AND 800MB RISING ABOVE THE FREEZING LEVEL. AT THIS POINT IT LOOKS TO BE A SMALL ENOUGH TO ONLY HAVE A SMALL IMPACT ON SNOW. IT WILL BE NOTHING LIKE THE 20:1 SLR VALUES OF MID WINTER. RATIOS WILL LIKELY BE ON THE ORDER OF 8:1 AND LOWER. THE MID MAY SUN IS GIVING NEARLY 15HRS BETWEEN SUNRISE AND SUNSET. CURRENTLY GOING WITH AN INCH OR LESS...MAINLY OVER THE FAR W HIGHER TERRAIN. LOOK FOR RIDGING ALOFT ALREADY BY THE END OF THE DAY TUESDAY. THE INITIAL TROUGH WILL HAVE MOVED TO E ONTARIO/S QUEBEC...WITH A SECONDARY TROUGH EXTENDING W ACROSS S MANITOBA AND SAKATCHEWAN. AT THE SFC...WINDS WILL ALREADY BE TURNING MORE OUT OF THE W TUESDAY NIGHT /MAINLY OVER THE W/...IN RESPONSE TO THE LARGE NEARING AREA OF HIGH PRESSURE EXTEDING FROM N CANADA THROUGH THE GULF STATES TUESDAY AFTERNOON THAT WILL PUSH ACROSS THE W HALF OF THE CWA OVERNIGHT. THE 500MB RIDGE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES THROUGH THURSDAY AS THE CENTRAL CANADIAN TROUGH LINGERS. DRY AND COOL AIR WILL BE OVERHEAD AS THE SFC HIGH OVER THE GREAT LAKES THURSDAY MORNING SHIFTS E TOWARDS THE ATLANTIC. ALTHOUGH WITH DIFFERING TIMING...THERE ARE INDICATIONS THAT A LOW IN THE SW FLOW WILL BE ABLE TO EJECT UP ACROSS THE N PLAINS ON THURSDAY. THE 10/12Z ECMWF SOLUTION FOLLOWS SIMILARLY TO THE CANADIAN...WHILE THE GFS KEEPS THE SYSTEM A WHOLE LOT WEAKER AND FARTHER TO THE S. CURRENTLY RUNNING WITH SLIGHT CHANCE TO LOW CHANCE POPS. GIVEN THE UNCERTAINTY WITH THIS 100 PLUS HR FCST...THIS SEEMS REASONABLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 137 PM EDT SUN MAY 10 2015 CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. INITIALLY...WILL NEED TO DEAL WITH AREAS OF LOW CLOUDS/MVFR CIGS ACROSS THE AREA. AS LOW-LEVEL WINDS VEER TO A MORE DOWNSLOPING EASTERLY DIRECTION AT KIWD...EXPECT MVFR CIGS TO LIFT TO VFR THIS AFTN. MEANWHILE...WITH BACK EDGE OF MVFR CIGS RAPIDLY APPROACHING KCMX FROM THE E...VFR CONDITIONS WILL LIKELY DEVELOP THERE THIS AFTN. AT KSAW...LARGE AREA OF MVFR CIGS TO THE E AND NE SUGGESTS MVFR CIGS MAY HOLD THRU THE AFTN...BUT NOT OUT OF THE QUESTION THAT IMPROVEMENT TO VFR COULD OCCUR LATE AFTN. TONIGHT...LOW PRES SYSTEM MOVING NE THRU THE PLAINS WILL SWING SHRA NE INTO THE UPPER LAKES...MAINLY LATE TONIGHT/MON MORNING. WHILE KSAW MAY REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF PCPN...VFR CONDITIONS MAY LINGER THIS EVENING AT KIWD AND POTENTIALLY THRU THE NIGHT AT KCMX. WITH THE ARRIVAL OF THE -SHRA...EXPECT A TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS. UPSLOPE FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT KCMX/KSAW BY LATE MORNING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 417 PM EDT SUN MAY 10 2015 TIGHT PRES GRADIENT WILL BE OVER LAKE SUPERIOR TONIGHT THRU MUCH OF MON AS HIGH PRES REMAINS NEARLY STATIONARY...CENTERED OVER FAR NRN ONTARIO...AND LOW PRES MOVES FROM NEBRASKA TO FAR NRN WI. AS A RESULT BRISK NE TO E WINDS OF 15-30KT WILL BE THE RULE ACROSS LAKE SUPERIOR. THE STRONGEST WINDS (GALE FORCE) WILL BE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW THRU AT LEAST EARLY MON MORNING WILL ENHANCE THE WINDS. THE GALES OVER THE WRN PORTION OF LAKE SUPERIOR WILL DIMINISH MON EVENING AS THE PRES GRADIENT WEAKENS AND LOW PRES SHIFTS E OF THE AREA...RESULTING IN BACKING WINDS. WINDS WILL DECREASE ACROSS THE LAKE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS E...WINDS MAY INCREASE A LITTLE FOR THU NIGHT/FRI. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162. GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
249 PM EDT SUN MAY 10 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 457 AM EDT SUN MAY 10 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION. WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW CLOUDS BACK INTO NRN UPPER MI. TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR. HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP. OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S. TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY 12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 248 PM EDT SUN MAY 10 2015 MUCH OF THIS PERIOD WILL BE COOL...WITH TEMPERATURES ONLY RETURNING TO NEAR NORMAL FOR DAYTIME HIGHS FOR FRIDAY FOR MONDAY NIGHT WE WILL START OFF WITH THE 500MB LOW SET UP ACROSS MN. THE 500MB LOW WILL BECOME AN OPEN WAVE OVERNIGHT AS IT MOVES OVER LAKE SUPERIOR AND EXITS TO THE NE TUESDAY. AT THE SFC...THE LOW WILL BE ACROSS THE S HALF OF THE CWA AT 00Z TUESDAY...SHIFTING TO THE E HALF BY 06Z...AND EXITING NE WITH A TROUGH LINGERING ACROSS UPPER MI THROUGH MUCH OF THE DAY TUESDAY. COULD WE HAVE SIGNIFICANT SNOW TUESDAY WITH THE HELP OF FAVORABLE UPSLOPE WINDS OFF LAKE SUPERIOR BEHIND THE EXITING SFC LOW? WHILE FCST MODELS ARE INDICATING 0-3IN OF SNOW MAINLY DURING THE DAY TUESDAY...THERE ARE A FEW NEGATIVES TO ANY SIGNIFICANT SNOW THAT COULD POSE A THREAT TO COMMERCE. THE NAM AND GFS DO SHOW A NOSE OF WARMER AIR BETWEEN 750MB AND 800MB RISING ABOVE THE FREEZING LEVEL. AT THIS POINT IT LOOKS TO BE A SMALL ENOUGH TO ONLY HAVE A SMALL IMPACT ON SNOW. IT WILL BE NOTHING LIKE THE 20:1 SLR VALUES OF MID WINTER. RATIOS WILL LIKELY BE ON THE ORDER OF 8:1 AND LOWER. THE MID MAY SUN IS GIVING NEARLY 15HRS BETWEEN SUNRISE AND SUNSET. CURRENTLY GOING WITH AN INCH OR LESS...MAINLY OVER THE FAR W HIGHER TERRAIN. LOOK FOR RIDGING ALOFT ALREADY BY THE END OF THE DAY TUESDAY. THE INITIAL TROUGH WILL HAVE MOVED TO E ONTARIO/S QUEBEC...WITH A SECONDARY TROUGH EXTENDING W ACROSS S MANITOBA AND SAKATCHEWAN. AT THE SFC...WINDS WILL ALREADY BE TURNING MORE OUT OF THE W TUESDAY NIGHT /MAINLY OVER THE W/...IN RESPONSE TO THE LARGE NEARING AREA OF HIGH PRESSURE EXTEDING FROM N CANADA THROUGH THE GULF STATES TUESDAY AFTERNOON THAT WILL PUSH ACROSS THE W HALF OF THE CWA OVERNIGHT. THE 500MB RIDGE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES THROUGH THURSDAY AS THE CENTRAL CANADIAN TROUGH LINGERS. DRY AND COOL AIR WILL BE OVERHEAD AS THE SFC HIGH OVER THE GREAT LAKES THURSDAY MORNING SHIFTS E TOWARDS THE ATLANTIC. ALTHOUGH WITH DIFFERING TIMING...THERE ARE INDICATIONS THAT A LOW IN THE SW FLOW WILL BE ABLE TO EJECT UP ACROSS THE N PLAINS ON THURSDAY. THE 10/12Z ECMWF SOLUTION FOLLOWS SIMILARLY TO THE CANADIAN...WHILE THE GFS KEEPS THE SYSTEM A WHOLE LOT WEAKER AND FARTHER TO THE S. CURRENTLY RUNNING WITH SLIGHT CHANCE TO LOW CHANCE POPS. GIVEN THE UNCERTAINTY WITH THIS 100 PLUS HR FCST...THIS SEEMS REASONABLE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 137 PM EDT SUN MAY 10 2015 CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. INITIALLY...WILL NEED TO DEAL WITH AREAS OF LOW CLOUDS/MVFR CIGS ACROSS THE AREA. AS LOW-LEVEL WINDS VEER TO A MORE DOWNSLOPING EASTERLY DIRECTION AT KIWD...EXPECT MVFR CIGS TO LIFT TO VFR THIS AFTN. MEANWHILE...WITH BACK EDGE OF MVFR CIGS RAPIDLY APPROACHING KCMX FROM THE E...VFR CONDITIONS WILL LIKELY DEVELOP THERE THIS AFTN. AT KSAW...LARGE AREA OF MVFR CIGS TO THE E AND NE SUGGESTS MVFR CIGS MAY HOLD THRU THE AFTN...BUT NOT OUT OF THE QUESTION THAT IMPROVEMENT TO VFR COULD OCCUR LATE AFTN. TONIGHT...LOW PRES SYSTEM MOVING NE THRU THE PLAINS WILL SWING SHRA NE INTO THE UPPER LAKES...MAINLY LATE TONIGHT/MON MORNING. WHILE KSAW MAY REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF PCPN...VFR CONDITIONS MAY LINGER THIS EVENING AT KIWD AND POTENTIALLY THRU THE NIGHT AT KCMX. WITH THE ARRIVAL OF THE -SHRA...EXPECT A TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS. UPSLOPE FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT KCMX/KSAW BY LATE MORNING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 457 AM EDT SUN MAY 10 2015 PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO 20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN LINGERS INTO THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162. GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KF AVIATION...ROLFSON MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
138 PM EDT SUN MAY 10 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 457 AM EDT SUN MAY 10 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION. WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW CLOUDS BACK INTO NRN UPPER MI. TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR. HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP. OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S. TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY 12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 359 AM EDT SUN MAY 10 2015 MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS. MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING. THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND OCCLUDED FNT. TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN AND NEAR LK SUP. TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER. WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH LKS AND BRING COOLER WX TO THE NEARSHORE AREAS. WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 137 PM EDT SUN MAY 10 2015 CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. INITIALLY...WILL NEED TO DEAL WITH AREAS OF LOW CLOUDS/MVFR CIGS ACROSS THE AREA. AS LOW-LEVEL WINDS VEER TO A MORE DOWNSLOPING EASTERLY DIRECTION AT KIWD...EXPECT MVFR CIGS TO LIFT TO VFR THIS AFTN. MEANWHILE...WITH BACK EDGE OF MVFR CIGS RAPIDLY APPROACHING KCMX FROM THE E...VFR CONDITIONS WILL LIKELY DEVELOP THERE THIS AFTN. AT KSAW...LARGE AREA OF MVFR CIGS TO THE E AND NE SUGGESTS MVFR CIGS MAY HOLD THRU THE AFTN...BUT NOT OUT OF THE QUESTION THAT IMPROVEMENT TO VFR COULD OCCUR LATE AFTN. TONIGHT...LOW PRES SYSTEM MOVING NE THRU THE PLAINS WILL SWING SHRA NE INTO THE UPPER LAKES...MAINLY LATE TONIGHT/MON MORNING. WHILE KSAW MAY REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF PCPN...VFR CONDITIONS MAY LINGER THIS EVENING AT KIWD AND POTENTIALLY THRU THE NIGHT AT KCMX. WITH THE ARRIVAL OF THE -SHRA...EXPECT A TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS. UPSLOPE FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT KCMX/KSAW BY LATE MORNING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 457 AM EDT SUN MAY 10 2015 PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO 20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN LINGERS INTO THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162. GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KC AVIATION...ROLFSON MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
755 AM EDT SUN MAY 10 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 457 AM EDT SUN MAY 10 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION. WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW CLOUDS BACK INTO NRN UPPER MI. TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR. HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP. OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S. TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY 12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 359 AM EDT SUN MAY 10 2015 MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS. MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING. THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND OCCLUDED FNT. TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN AND NEAR LK SUP. TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER. WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH LKS AND BRING COOLER WX TO THE NEARSHORE AREAS. WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 748 AM EDT SUN MAY 10 2015 LOW-LEVEL EASTERLY UPSLOPE WINDS WILL FAVOR MVFR CIGS AT SAW UNTIL WINDS VEER MORE TO THE E WHEN SOME IMPROVEMENT TO VFR IS EXPECTED. VFR CONDITIONS AT CMX ARE EXPECTED TO GIVE WAY MVFR AS WINDS BECOME MORE EASTERLY WHICH WILL DRAW IN MORE UPSTREAM LOW LEVEL MOSITURE. WINDS VEERING TO ENE AT IWD WILL BE LESS FAVORABLE FOR LOWER CIGS. SO...VFR CONDITIONS SHOULD PERSIST UNTIL AT LEAST LATER IN THE AFTERNOON. SOME LIGHT RAIN MAY MOVE INTO IWD BY LATE THIS EVENING AND LATE TONIGHT AT SAW WHICH WILL HELP LOWER CIGS BACK INTO THE MVFR RANGE. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 457 AM EDT SUN MAY 10 2015 PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO 20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN LINGERS INTO THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162. GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KC AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EDT SUN MAY 10 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 457 AM EDT SUN MAY 10 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION. WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW CLOUDS BACK INTO NRN UPPER MI. TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR. HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP. OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S. TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY 12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 359 AM EDT SUN MAY 10 2015 MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS. MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING. THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND OCCLUDED FNT. TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN AND NEAR LK SUP. TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER. WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH LKS AND BRING COOLER WX TO THE NEARSHORE AREAS. WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 121 AM EDT SUN MAY 10 2015 LOW-LEVEL EASTERLY UPSLOPE WINDS WILL CAUSE MVFR CIGS AT CMX AND SAW WHICH WILL LAST THROUGH THE FORECAST PERIOD. IWD WILL HAVE THE SAME THING HAPPEN...BUT IT WILL BE BY SUNDAY MORNING. MVFR CONDITIONS WILL THEN LAST ALL OF SUNDAY AT ALL SITES WITH NORTHEAST/EAST UPSLOPE FLOW. DID PUT SOME RAIN WITH NEXT SYSTEM COMING IN SUN EVENING AT IWD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 457 AM EDT SUN MAY 10 2015 PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO 20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN LINGERS INTO THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162. GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KC AVIATION...07 MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 AM EDT SUN MAY 10 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 431 PM EDT SAT MAY 9 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN AMPLIFIED RIDGE ALONG THE W COAST OF NAMERICA. DOWNSTREAM...TROF EXTENDS FROM HUDSON BAY TO THE SRN ROCKIES. ENERGY IN THE TROF IS SPLIT WITH THE NRN STREAM PORTION EXTENDING AS FAR S AS MT/ND. FARTHER S...VIGOROUS MID LEVEL LOW IN THE SRN STREAM PORTION OF THE TROF IS CENTERED NEAR THE 4 CORNERS. CLOSER TO HOME...LOW CLOUDS HAVE DOMINATED MUCH OF THE FCST AREA TODAY...THOUGH IN THE LAST COUPLE OF HRS...SATELLITE IMAGERY SHOWS HIGH EARLY MAY SUN ANGLE BEGINNING TO MIX OUT THE MOISTURE FROM THE EDGES. CLOUDS AND -DZ ARE HOLDING TOUGH OVER NCNTRL UPPER MI WHERE STRONGEST UPSLOPE IS OCCURRING. FCST IN THE SHORT TERM WILL REVOLVE AROUND CLOUD TRENDS TONIGHT AND THEN POTENTIAL OF -SHRA SUN AS MID LEVEL LOW LIFTS INTO SD/NEBRASKA WITH WEAK LEAD ENERGY EJECTING INTO THE WRN GREAT LAKES. OF IMMEDIATE CONCERN IS THE LOW CLOUDS AND PATCHY -DZ. SEVERAL MORE HRS OF DAYTIME HEATING WILL CONTINUE TO EAT AWAY AT THE LOW CLOUDS FROM THE EDGES...BUT HAVE LOW CONFIDENCE IN ALL OF THE CLOUDS DISSIPATING OVER NCNTRL UPPER MI. INCREASINGLY DIFFLUENT LOW-LEVEL FLOW OVER THE LAKE AS LAKE BREEZE CIRCULATION CONTINUES TO INCREASE FOR A FEW MORE HRS WILL ALSO WORK TO AID CLEARING. FOR NOW...FCST WILL REFLECT AN OPTIMISTIC TREND LATE AFTN/EARLY EVENING. AS A RESULT...FAVORED THE LOWER SIDE OF GUIDANCE FOR MINS TONIGHT... ESPECIALLY W AND WELL INTO THE INTERIOR OVER THE CNTRL WHERE SKIES ARE LIKELY TO HAVE LEAST CLOUDINESS FOR THE LONGEST PERIOD. TRADITIONAL COLD SPOTS MAY FALL TO FREEZING. GIVEN THE ABUNDANCE OF LOW CLOUDS NE AND E OF LAKE SUPERIOR...MAY SEE LOW CLOUDS INCREASE AGAIN LATE IN THE NIGHT OVER THE CNTRL AND E AS LOW-LEVEL NE FLOW CONTINUES. IF LOW CLOUDS REDEVELOP INTO NCNTRL UPPER MI LATE TONIGHT...MAY HAVE A REPEAT PERFORMANCE OF PATCHY -DZ SUN MORNING. OTHERWISE...THE TREND FROM ALL MODELS IS DEFINITELY FOR A DRIER LOOK ON SUN WITH SHORTWAVE SWINGING NE INTO THE GREAT LAKES AHEAD OF MAIN SYSTEM MOVING OUT OVER THE WRN PLAINS. SHORTWAVE IN QUESTION IS AIDING CONVECTION CURRENTLY OVER THE SRN PLAINS. MODELS INDICATE TRACK OF THIS SHORTWAVE PASSING TO THE SE OF HERE. GIVEN THE LACK OF DEEP LAYER FORCING AND MUCH WEAKER ISENTROPIC ASCENT ACROSS THE FCST AREA COMPARED TO PREVIOUS MODEL RUNS...THE DRIER TREND APPEARS REASONABLE. HAVE SCALED BACK POPS CONSIDERABLY FOR SUN WITH SCHC POPS ONLY OVER THE SCNTRL IN THE AFTN. WITH THE A DRIER FCST... RAISED MAX TEMPS SLIGHTLY. EXPECT MOSTLY 40S NEAR LAKE SUPERIOR... 50S INLAND. MAY REACH 60F IN A FEW SPOTS. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 359 AM EDT SUN MAY 10 2015 MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS. MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING. THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND OCCLUDED FNT. TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN AND NEAR LK SUP. TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER. WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH LKS AND BRING COOLER WX TO THE NEARSHORE AREAS. WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 121 AM EDT SUN MAY 10 2015 LOW-LEVEL EASTERLY UPSLOPE WINDS WILL CAUSE MVFR CIGS AT CMX AND SAW WHICH WILL LAST THROUGH THE FORECAST PERIOD. IWD WILL HAVE THE SAME THING HAPPEN...BUT IT WILL BE BY SUNDAY MORNING. MVFR CONDITIONS WILL THEN LAST ALL OF SUNDAY AT ALL SITES WITH NORTHEAST/EAST UPSLOPE FLOW. DID PUT SOME RAIN WITH NEXT SYSTEM COMING IN SUN EVENING AT IWD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 431 PM EDT SAT MAY 9 2015 PRES GRADIENT WILL BE TIGHTENING OVER THE UPPER LAKES DURING THE NEXT 24-48HRS AS HIGH PRES REMAINS ACROSS MANITOBA/NRN ONTARIO AND LOW PRES MOVES NE ACROSS THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE MORNING/EARLY AFTN ON SUN AND THEN CONTINUE THRU MON AFTN BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE AREA/WINDS BACK AND PRES GRADIENT WEAKENS. ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT SUN AND TO 20-30KT SUN NIGHT/MON. WINDS WILL THEN DECREASE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN LINGERS THRU THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162. GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KC AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
121 AM EDT SUN MAY 10 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 431 PM EDT SAT MAY 9 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN AMPLIFIED RIDGE ALONG THE W COAST OF NAMERICA. DOWNSTREAM...TROF EXTENDS FROM HUDSON BAY TO THE SRN ROCKIES. ENERGY IN THE TROF IS SPLIT WITH THE NRN STREAM PORTION EXTENDING AS FAR S AS MT/ND. FARTHER S...VIGOROUS MID LEVEL LOW IN THE SRN STREAM PORTION OF THE TROF IS CENTERED NEAR THE 4 CORNERS. CLOSER TO HOME...LOW CLOUDS HAVE DOMINATED MUCH OF THE FCST AREA TODAY...THOUGH IN THE LAST COUPLE OF HRS...SATELLITE IMAGERY SHOWS HIGH EARLY MAY SUN ANGLE BEGINNING TO MIX OUT THE MOISTURE FROM THE EDGES. CLOUDS AND -DZ ARE HOLDING TOUGH OVER NCNTRL UPPER MI WHERE STRONGEST UPSLOPE IS OCCURRING. FCST IN THE SHORT TERM WILL REVOLVE AROUND CLOUD TRENDS TONIGHT AND THEN POTENTIAL OF -SHRA SUN AS MID LEVEL LOW LIFTS INTO SD/NEBRASKA WITH WEAK LEAD ENERGY EJECTING INTO THE WRN GREAT LAKES. OF IMMEDIATE CONCERN IS THE LOW CLOUDS AND PATCHY -DZ. SEVERAL MORE HRS OF DAYTIME HEATING WILL CONTINUE TO EAT AWAY AT THE LOW CLOUDS FROM THE EDGES...BUT HAVE LOW CONFIDENCE IN ALL OF THE CLOUDS DISSIPATING OVER NCNTRL UPPER MI. INCREASINGLY DIFFLUENT LOW-LEVEL FLOW OVER THE LAKE AS LAKE BREEZE CIRCULATION CONTINUES TO INCREASE FOR A FEW MORE HRS WILL ALSO WORK TO AID CLEARING. FOR NOW...FCST WILL REFLECT AN OPTIMISTIC TREND LATE AFTN/EARLY EVENING. AS A RESULT...FAVORED THE LOWER SIDE OF GUIDANCE FOR MINS TONIGHT... ESPECIALLY W AND WELL INTO THE INTERIOR OVER THE CNTRL WHERE SKIES ARE LIKELY TO HAVE LEAST CLOUDINESS FOR THE LONGEST PERIOD. TRADITIONAL COLD SPOTS MAY FALL TO FREEZING. GIVEN THE ABUNDANCE OF LOW CLOUDS NE AND E OF LAKE SUPERIOR...MAY SEE LOW CLOUDS INCREASE AGAIN LATE IN THE NIGHT OVER THE CNTRL AND E AS LOW-LEVEL NE FLOW CONTINUES. IF LOW CLOUDS REDEVELOP INTO NCNTRL UPPER MI LATE TONIGHT...MAY HAVE A REPEAT PERFORMANCE OF PATCHY -DZ SUN MORNING. OTHERWISE...THE TREND FROM ALL MODELS IS DEFINITELY FOR A DRIER LOOK ON SUN WITH SHORTWAVE SWINGING NE INTO THE GREAT LAKES AHEAD OF MAIN SYSTEM MOVING OUT OVER THE WRN PLAINS. SHORTWAVE IN QUESTION IS AIDING CONVECTION CURRENTLY OVER THE SRN PLAINS. MODELS INDICATE TRACK OF THIS SHORTWAVE PASSING TO THE SE OF HERE. GIVEN THE LACK OF DEEP LAYER FORCING AND MUCH WEAKER ISENTROPIC ASCENT ACROSS THE FCST AREA COMPARED TO PREVIOUS MODEL RUNS...THE DRIER TREND APPEARS REASONABLE. HAVE SCALED BACK POPS CONSIDERABLY FOR SUN WITH SCHC POPS ONLY OVER THE SCNTRL IN THE AFTN. WITH THE A DRIER FCST... RAISED MAX TEMPS SLIGHTLY. EXPECT MOSTLY 40S NEAR LAKE SUPERIOR... 50S INLAND. MAY REACH 60F IN A FEW SPOTS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 333 PM EDT SAT MAY 9 2015 RAIN ASSOCIATED WITH AN UPPER SHORTWAVE AND SFC LOW WILL MOVE INTO THE AREA FROM THE SW SUN NIGHT AND CONTINUE INTO MON. AS THE SFC LOW SHIFTS ACROSS THE AREA MON EVENING INTO MON NIGHT...SHIFTING A DRY SLOT ACROSS MOST OF THE CWA. THIS WILL DIMINISH THE RAIN UNTIL MOISTURE MOVES BACK IN FROM THE W ON THE BACK SIDE OF THE SYSTEM LATE MON NIGHT INTO TUE. MUCH COLDER AIR SURGES IN ON TUE WITH 850MB TEMPS DROPPING TO AROUND -15C OVER AT LEAST NWRN UPPER MI BY 00Z WED. THIS WILL SUPPORT A CHANGE OVER TO MIXED PRECIP OVER THE NRN/NWRN PORTIONS OF UPPER MI ON TUE AND MOSTLY SNOW TUE NIGHT. THE FORCING TUE INTO TUE NIGHT WILL COME FROM BOTH THE WRAP AROUND FROM THE LOW AND FROM A WEAK SHORTWAVE MOVING IN FROM THE NW...WITH ONLY LIGHT PRECIP EXPECTED AND LITTLE TO NO SNOW ACCUMULATION. MON WILL SEE HIGHS IN THE 50S INLAND FROM LAKE SUPERIOR AND IN THE 40S ALONG THE BIG LAKE. TUE LOOKS TO BE THE COLDEST DAY OF THE WEEK WITH HIGHS BARELY REACHING 50F OVER THE SCENTRAL AND IN THE 40S ELSEWHERE. IT WILL ALSO BE CLOUDY AND BREEZY MAKING IT FEEL EVEN COLDER. TEMPS WILL BE TRICKY TUE NIGHT AS CLOUDS WILL BE CLEARING AND THE COLDER AIRMASS REMAINS. SHOULD SEE LOWS NEAR OR BELOW FREEZING WITH THE CURRENT EXPECTATION OF CLOUDS CLEARING BY SUNRISE WED...BUT MUCH COLDER TEMPS ARE POSSIBLE IF THE CLOUDS CLEAR EARLIER. THE AIRMASS WILL BEGIN TO MODERATE ON WED AS 850MB TEMPS INCREASE TO AROUND 0C BY 00Z THU WITH A 1031MB SFC HIGH MOVING OVER THE CWA. SHOULD BE AN OVERALL PLEASANT DAY WITH SUNNY SKIES...LIGHT WINDS AND HIGHS IN THE 50S INLAND TO UPPER 40S RIGHT ALONG LAKE SUPERIOR. SIGNIFICANT UNCERTAINTY EXISTS IN THE THU-SAT PORTION OF THE FORECAST AS MODELS CONTINUITY AND AGREEMENT IS POOR. THE GENERAL IDEA IS UPPER RIDGING BUILDING INTO OR NEAR THE REGION...PROMOTING WARMER TEMPS. RAIN CAN NOT BE RULED OUT. LET CONSENSUS OF GUIDANCE HANDLE THIS PART OF THE FORECAST. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 121 AM EDT SUN MAY 10 2015 LOW-LEVEL EASTERLY UPSLOPE WINDS WILL CAUSE MVFR CIGS AT CMX AND SAW WHICH WILL LAST THROUGH THE FORECAST PERIOD. IWD WILL HAVE THE SAME THING HAPPEN...BUT IT WILL BE BY SUNDAY MORNING. MVFR CONDITIONS WILL THEN LAST ALL OF SUNDAY AT ALL SITES WITH NORTHEAST/EAST UPSLOPE FLOW. DID PUT SOME RAIN WITH NEXT SYSTEM COMING IN SUN EVENING AT IWD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 431 PM EDT SAT MAY 9 2015 PRES GRADIENT WILL BE TIGHTENING OVER THE UPPER LAKES DURING THE NEXT 24-48HRS AS HIGH PRES REMAINS ACROSS MANITOBA/NRN ONTARIO AND LOW PRES MOVES NE ACROSS THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE MORNING/EARLY AFTN ON SUN AND THEN CONTINUE THRU MON AFTN BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE AREA/WINDS BACK AND PRES GRADIENT WEAKENS. ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT SUN AND TO 20-30KT SUN NIGHT/MON. WINDS WILL THEN DECREASE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN LINGERS THRU THU. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162. GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...07 MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
748 PM CDT MON MAY 11 2015 .UPDATE... ISSUED AT 734 PM CDT MON MAY 11 2015 UPDATED POPS AS CURRENT RADAR TRENDS SHOW PRECIPITATION INCREASING IN COVERAGE AND INTENSITY ACROSS THE FORECAST AREA. AN AREA OF CONVECTIVE SHOWERS WITH REFLECTIVITY VALUES OVER 40 DBZ HAS DEVELOPED ABOUT 30 MILES NORTH OF DULUTH...ON THE LEADING EDGE OF THE H50 LOW/VORT MAX AND AN REGION OF LOW LEVEL FRONTOGENESIS DEPICTED IN THE LATEST RUC MESO ANALYSIS. ANTICIPATE ECHOES TO CONTINUE TO INTENSIFY OVER THE IRON RANGE/ARROWHEAD AS THE VORT MAX TRANSLATES EAST ACROSS THE FORECAST AREA. AT THIS TIME THE PRECIP TYPE BEING REPORTED BY AUTOMATED STATIONS IS ALL RAIN. HOWEVER...AS PROFILES COOL THROUGH THE EVENING THE RAIN IS EXPECTED TO CHANGE OVER TO SNOW FOR AT LEAST THE NORTHERN PORTION OF MN. ALSO ADDED AREAS OF FOG ALONG SOUTH SHORE OF LAKE SUPERIOR WHERE SURFACE OBSERVATIONS AND SPOTTERS HAVE REPORTED VISIBILITY OF LESS THAN A HALF MILE AT TIMES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 328 PM CDT MON MAY 11 2015 A CLOSED AND NEARLY STACKED UPPER LOW OVER MINNESOTA WILL CONTINUE SHOWERS OVER THE REGION TONIGHT AS IT SLOWLY MOVES EAST. THE STRONGEST LIFT NORTH OF THE BAROCLINIC ZONE WILL BE IN NORTHERN MINNESOTA BUT CANNOT RULE OUT SHOWERS ACROSS REST OF THE FORECAST AREA. COLD AIR ADVECTION BEHIND THE LOW LATER TONIGHT COULD RESULT IN SNOW SHOWERS. BUT WITH THE WET GROUND, DO NOT EXPECT MUCH ACCUMULATION. THERE WILL BE A GRADUAL END TO ANY SHOWERS SLOWLY FORM WEST TO EAST TUESDAY WITH SFC HIGH PRESSURE BUILDING OVER THE AREA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 328 PM CDT MON MAY 11 2015 THE NORTHLAND CAN EXPECT A BIT OF WET PATTERN OVER THE NEXT WEEK WITH SEVERAL OPPORTUNITIES FOR RAIN. HIGH PRESSURE WILL BE OVER THE NORTHLAND TUESDAY NIGHT AND WILL MAKE FOR A COOL AND RELATIVELY CLEAR NIGHT. TEMPERATURES WILL DIP INTO THE LOWER 30S AND UPPER 20S. THERE WILL BE INCREASING CLOUD COVER FROM THE WEST LATE TUESDAY NIGHT AND WEDNESDAY AS A MID LEVEL FRONTOGENETICAL BAND MOVES INTO THE NORTHLAND. THIS FRONTOGENETICAL BAND WILL LIKELY RESULT IN RAINS SHOWERS FOR PARTS OF THE NORTHLAND WEDNESDAY AND WEDNESDAY NIGHT. THE SW FORECAST AREA HAS THE BEST CHANCE OF RAIN. A LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS WEDNESDAY NIGHT WILL LIFT INTO THE NORTHERN PLAINS THURSDAY AND THURSDAY NIGHT. THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THIS WILL BRING MORE RAIN TO THE NORTHLAND THURSDAY INTO FRIDAY. THE SOUTHERN FORECAST AREA HAS THE BEST CHANCE OF RAIN WITH THE PASSAGE OF THIS SYSTEM. WEAK HIGH PRESSURE WILL GIVE ANOTHER SHORT BREAK BETWEEN WEATHER SYSTEMS LATE FRIDAY AND SATURDAY. A LOW IN THE NORTHERN PLAINS WILL LIFT A WARM FRONT INTO THE UPPER MIDWEST. THE GFS AND ECMWF ARE IN RELATIVELY GOOD AGREEMENT THAT THE NORTHLAND WILL SEE SHOWERS AND STORMS LATE SATURDAY INTO EARLY MONDAY WITH THE PASSAGE OF THIS SYSTEM. THE SOUTHERN FORECAST AREA HAS THE BEST CHANCE OF SEEING THUNDER SINCE THE WARM FRONT MIGHT GET SHUNTED SOUTH BECAUSE OF COOL EASTERLY FLOW FROM LAKE SUPERIOR AND ONTARIO. HOWEVER...THERE COULD BE ELEVATED CONVECTION NORTH OF THE WARM FRONT...BUT THOUGHT IT TOO EARLY TO INCLUDE THUNDER OVER ALL OF THE NORTHLAND. TEMPERATURES WILL REMAIN COOL FOR THE MIDDLE OF THE WEEK...BUT WILL LIKELY REBOUND TO CLOSE TO NORMAL BY THIS WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 734 PM CDT MON MAY 11 2015 WIDESPREAD RAIN...MIXING WITH SNOW AT TIMES AND LIFR/IFR CONDITIONS OVERNIGHT. CEILINGS WILL GRADUALLY IMPROVE FROM THE WEST THROUGH TUESDAY MORNING AS COOLER AND DRIER AIR FILTERS IN THE REGION. HOWEVER...THERE WILL BE SUFFICIENT INSTABILITY AND MOISTURE TO SUPPORT SCATTERED SHOWERS THROUGH MUCH OF THE DAY. A FEW OF THE SHOWERS WILL HAVE THE POTENTIAL TO CONTAIN GRAUPEL/SMALL HAIL AND GUSTY NORTH WINDS TO 30 KT. && .PRELIMINARY POINT TEMPS/POPS... DLH 35 49 34 50 / 80 40 10 60 INL 32 49 30 56 / 70 30 10 0 BRD 35 55 37 52 / 80 20 10 60 HYR 37 49 31 56 / 80 50 10 40 ASX 35 46 32 52 / 80 50 10 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ121- 141>148. SMALL CRAFT ADVISORY UNTIL 4 AM CDT TUESDAY FOR LSZ140. && $$ UPDATE...GRANING SHORT TERM...CLC LONG TERM...GROCHOCINSKI AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS DULUTH MN
357 AM CDT SUN MAY 10 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 357 AM CDT SUN MAY 10 2015 WINDY AND COOLER TODAY WITH RAIN ON THE WAY. GENERALLY HAVE SLOWED DOWN ONSET OF PRECIPITATION DUE TO THE MUCH DRIER THAN ORIGINALLY ANTICIPATED AIR ACROSS THE REGION...BUT RAINFALL WILL INDEED SPREAD ACROSS THE ENTIRE REGION BY THIS EVENING. MOST RAIN WILL FALL OVERNIGHT TONIGHT...BUT CONTINUE THROUGH MONDAY. TOTAL RAINFALL VALUES UP TO AN INCH OR SO ACROSS MUCH OF NORTHEAST MINNESOTA THROUGH MONDAY EVENING...WITH LESSER AMOUNTS OF A QUARTER INCH TO A HALF INCH OVER MOST OF NORTHWEST WISCONSIN. THERE IS STILL A CHANCE FOR A FEW RUMBLES OF THUNDER TONIGHT...BUT WIDESPREAD THUNDERSTORMS ARE NOT EXPECTED WITH THIS SYSTEM. ON THE SYNOPTIC SCALE A VERY DYNAMIC PATTERN ACROSS THE NATIONS MID-SECTION WITH AN UPPER LEVEL LOW OVER NORTHEAST COLORADO MOVING NORTH INTO THE CENTRAL/NORTHERN PLAINS TODAY INTO TOMORROW. THE ASSOCIATED SURFACE LOW OVER THE CENTRAL PLAINS WILL MOVE NORTH-NORTHEAST INTO SOUTHERN MINNESOTA BY MONDAY MORNING...THEN GRADUALLY WEAKEN AND MOVE EAST. WHILE THERE IS SOME LIGHT PRECIP ONGOING THIS MORNING ACROSS THE BORDERLAND REGION DUE TO THE ENTRANCE REGION OF THE H3 JET...THE MAIN EVENT WILL GRADUALLY ARRIVE LATE TODAY AND REALLY INTENSIFY OVERNIGHT TONIGHT. NOSE OF A 100KT H3 JET ASSOCIATED WITH THE UPPER LOW WILL MOVE INTO THE REGION THIS EVENING...WITH THE BEST MID-LEVEL PVA ARRIVING TOWARDS MIDNIGHT AS THE H5 LOW MOVES INTO THE CENTRAL/EASTERN DAKOTAS. WHILE THE SFC LOW WILL JUST GRAZE THE SOUTHERN EDGE OF THE CWA ON MONDAY...THE INCREASED PRESSURE GRADIENT CAUSED BY THE SFC LOW AND A STUBBORN HIGH OVER NORTHERN MANITOBA/NORTHWEST ONTARIO WILL LEAD TO STRONG EASTERLY WINDS TODAY INTO TOMORROW. TODAY...CLOUDY AND WINDY...ESPECIALLY FROM THE TWIN PORTS WEST TO THE BRAINERD LAKES REGION. LIGHT RAIN SHOWERS WILL GRADUALLY FROM SOUTHWEST TO NORTHEAST. DO NOT EXPECT A STEADY RAIN TO DEVELOP JUST YET...JUST SOME OFF AND ON LIGHT RAIN THROUGH THE DAY. WINDS WILL BE THE MAIN STORY WITH GUSTY EAST-NORTHEASTERLY WINDS OF 10 TO 20 MPH AND GUSTS UP TO 35 MPH OR SO. STRONGEST WINDS WILL BE IN THE TWIN PORTS REGION WHERE A FEW GUSTS APPROACHING 45 MPH CANNOT BE RULED OUT. HIGH TEMPERATURES WILL BE COOLER...IN THE LOW 40S BY LAKE SUPERIOR TO THE LOW 50S IN NORTH CENTRAL MINNESOTA. WHILE COAST WISCONSIN WILL BE LIMITED TO THE MID 40S TO LOW 50S...FURTHER INLAND SUCH AS SAWYER AND PRICE COUNTY WILL WARM UP TO THE LOW 60S DUE TO A COMBINATION OF LOW LEVEL WARM AIR ADVECTION AND DELAYED ONSET OF THICK CLOUD COVER. TONIGHT...RAIN...HEAVY AT TIMES. A FEW RUMBLES OF THUNDER DUE TO ELEVATED CONVECTION MAINLY SOUTH OF HIGHWAY 2. SOME SNOW MAY MIX IN ACROSS THE TIP OF THE ARROWHEAD AND ELSEWHERE ACROSS THE REGION...BUT NO SNOW ACCUMULATION IS EXPECTED OVERNIGHT. EAST WINDS WILL REMAIN WINDY AT 10 TO 20 MPH...STRONGEST ALONG THE COAST OF LAKE SUPERIOR AND ESPECIALLY UP THE NORTH SHORE WHERE GUSTS TO 30 MPH CAN BE EXPECTED OVERNIGHT. TOTAL OVERNIGHT RAINFALL AMOUNTS OF A HALF INCH TO THREE QUARTERS OF AN INCH...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. TEMPERATURES FALLING TO THE MID TO UPPER 30S. MONDAY...OFF AND ON RAIN CONTINUES. COOL WITH WINDS GRADUALLY DECREASING. A DRY SLOT MAY WORK ITS WAY INTO THE INTERSTATE 35 CORRIDOR EAST ACROSS NORTHWEST WISCONSIN AND WINDS WILL TURN TO BECOME OUT OF THE NORTHEAST AS THE SFC LOW MOVES EAST. TOTAL RAINFALL THROUGH THE DAYTIME PERIOD /7AM TO 7PM/ AROUND A QUARTER TO HALF INCH...POTENTIALLY LOWER IN AREAS SOUTH OF HIGHWAY 2 IF DRY SLOT BUILDS IN EARLIER THAN ANTICIPATED. HIGHS COOLER AS COLD AIR MOVES IN BEHIND THE LOW...IN THE LOW 40S ACROSS NORTHEAST MINNESOTA AND INTO THE MID 50S TO NEAR 60S ACROSS PARTS OF NORTHWEST WISCONSIN. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 357 AM CDT SUN MAY 10 2015 MONDAY NIGHT AND TUESDAY THE SPRING STORM SYSTEM WILL SLOWLY MOVE EAST OF THE AREA...WITH AN AREA OF FRONTOGENESIS THAT WILL AFFECT MUCH OF THE FORECAST AREA MONDAY NIGHT AND EARLY TUESDAY. AT THIS TIME...THE SYSTEM WILL BE PULLING COLDER AIR INTO NORTHERN MINNESOTA FROM THE NORTH...WITH 850MB TEMPERATURES DROPPING TO AROUND -4 BY TUESDAY MORNING. SURFACE TEMPERATURES WILL ALSO BE DOWN IN THE LOW TO MID 30S...MAKING ACCUMULATING SNOW A REAL POSSIBILITY WITH THIS SYSTEM. HOWEVER...THE RAINFALL THAT WILL COME BEFORE IT AND THE RELATIVELY WARM SUBSOIL TEMPERATURES IN THE LOW 40S ARE GOING TO CAUSE THE SNOW TO DO A LOT OF MELTING AS SOON AS IT HITS THE GROUND...AND IS UNLIKELY TO LAST PAST NOON TUESDAY. AN INCH OR TWO OF SNOW MAY FALL...BUT DUE TO MELTING AND COMPACTION WE ARE UNLIKELY TO SEE MORE THAN AN INCH OF SNOW ON THE GROUND AT ANY TIME. WOULD BE A LOT MORE EXCITED ABOUT SNOWFALL ACCUMULATIONS IF THE STRONG FORCING WE SEE EARLIER IN THIS SYSTEM WERE TO OVERLAP WITH THE COLD TEMPERATURES. QUIETER CONDITIONS RETURN FOR TUESDAY NIGHT AND EARLY WEDNESDAY AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE AREA. WITH THE COLD AIR BEHIND THE RETREATING LOW PRESSURE SYSTEM...TUESDAY NIGHT COULD BE PRETTY COLD...WITH MINS IN THE LOW 30S AND EVEN UPPER 20S FOR A LARGE PORTION OF THE FORECAST AREA. WE ARE STILL GETTING FREEZING TEMPERATURES OFTEN ENOUGH...WE HAD TWO NIGHTS OF NEAR OR BELOW FREEZING JUST 5-6 DAYS AGO...THAT WE ARE UNLIKELY TO BE ISSUING ANY FROST/FREEZE HEADLINES FOR THIS EVENT. ANOTHER STRONG SPRING STORM SYSTEM IS EXPECTED TO MOVE ACROSS THE MIDWEST WEDNESDAY THROUGH FRIDAY...WITH MAINLY RAIN EXPECTED THROUGH THE PERIOD. TEMPERATURES TO START OUT AS FAIRLY COOL WITH HIGHS NEAR TO BELOW NORMAL WEDNESDAY...GRADUALLY WARMING TO ABOVE NORMAL BY FRIDAY AS THE SYSTEM ADVECTS MORE WARM AIR INTO THE AREA THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1227 AM CDT SUN MAY 10 2015 AN AREA OF LOW PRESSURE WILL TRACK NORTHEASTWARDS TONIGHT FROM EASTERN COLORADO THROUGH NEBRASKA...AND INTO SOUTHWEST MINNESOTA BY MONDAY MORNING. DURING THIS TIMEFRAME HIGH PRESSURE WILL BUILD OVER NORTHERN ONTARIO. AS A RESULT A TIGHT PRESSURE GRADIENT WILL DEVELOP OVER THE FORECAST AREA...WHICH WILL RESULT IN GUSTY EASTERLY AND NORTHEASTERLY WINDS. GUSTY CONDITIONS ARE EXPECTED TO PERSIST THROUGH MONDAY WITH THE HIGHEST GUSTS APPROACHING 40 KTS AT KDLH. LATEST 00Z GUIDANCE AND HRRR TRENDS SHOW PRECIPITATION MOVE IN THE VICINITY OF KINL. AS A RESULT...BROUGHT VCSH INTO KINL BETWEEN 11Z-16Z. EXPECT PRECIPITATION ASSOCIATED WITH THE WARM FRONT FROM THE LOW TO MOVE IN BETWEEN 18Z AND 01Z...AFFECTING THE KBRD SITE FIRST AND SPREADING NORTHEASTWARDS TO OTHER TERMINALS. VFR CONDITIONS EXPECTED AT KHYR AND KINL THROUGH THE FORECAST PERIOD...HOWEVER MVFR CIGS POSSIBLE AT KHYR AFTER 02Z...BUT NOT CONFIDENT DUE TO DRIER AIR IN LOWER LEVELS. ALL OTHER TERMINALS WILL SEE MVFR CONDITIONS DEVELOP BETWEEN 22Z-01Z. KDLH AND KHIB MAY SEE IFR CIGS LATE IN THE PERIOD...BUT NOT CONFIDENT ON THE TIMING. KBRD WILL SEE IFR CIGS DEVELOP 01Z. && .PRELIMINARY POINT TEMPS/POPS... DLH 43 38 40 35 / 50 100 70 70 INL 52 36 39 33 / 30 100 90 70 BRD 49 40 49 36 / 50 100 70 60 HYR 57 45 57 35 / 20 90 60 60 ASX 44 37 45 35 / 40 90 70 70 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ143>147. GALE WARNING FROM 10 AM THIS MORNING TO 4 AM CDT TUESDAY FOR LSZ121-140>148. && $$ SHORT TERM...JJM LONG TERM...LE AVIATION...WL/LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1227 AM CDT SUN MAY 10 2015 .UPDATE... ISSUED AT 1227 AM CDT SUN MAY 10 2015 UPDATED AVIATION SECTION BELOW. UPDATE ISSUED AT 1010 PM CDT SAT MAY 9 2015 LOWERED MIN TEMPS ALONG THE NORTH SHORE A FEW DEGREES AS COLDER AIR FROM LAKE SUPERIOR IS AFFECTING THE AREA. REST OF THE FORECAST ON TRACK. UPDATE ISSUED AT 717 PM CDT SAT MAY 9 2015 MADE SOME ADJUSTMENTS TO CLOUD COVER WITH LARGE AREA OF CLEAR SKY IN NW WI AT 00Z. DELAYED THE ONSET OF THE PCPN UNTIL AFTER 12Z SUNDAY PER THE LATEST SHORT TERM HRRR AND RAP. REST OF THE FORECAST ON TRACK. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 330 PM CDT SAT MAY 9 2015 HIGH PRESSURE OVER SOUTHERN CANADA WILL CONTINUE TO GIVE THE NORTHLAND DRY NORTH TO NE FLOW THROUGH TONIGHT. A STUBBORN LOW LEVEL CLOUD DECK OVER NE MINNESOTA WILL SLOWLY SCATTER OUT THROUGH THE REST OF THE THIS AFTERNOON AND EARLY THIS EVENING. THE CLOUD DECK HAS BEEN SLOW TO ERODE BECAUSE OF THE LACK OF WIND TO MIX IT OUT...BUT NW WISCONSIN HAS CLEARED OUT DUE TO STRONGER WINDS COMING OFF OF LAKE SUPERIOR. A LOW PRESSURE SYSTEM IN EASTERN COLORADO WILL MOVE INTO THE CENTRAL PLAINS TONIGHT AND SUNDAY ON TRACK TOWARDS MINNESOTA. THIS SYSTEM WILL BRING INCREASING MID LEVEL MOISTURE INTO THE UPPER MIDWEST AND EVENTUALLY RAINS. IT WILL TAKE SOME TIME FOR THE LOW LEVELS DUE TO THE THE RELATIVELY DRY FLOW FROM CANADA...SO THIS MEANS IT WILL TAKE SOME TIME FOR THE RAINS TO MOVE INTO THE REGION. THE GFS/NAM/SREF/GEM/ECMWF MODELS DRASTICALLY DELAYED THE TIMING WITH WHICH THE PCPN MOVES INTO THE NORTHLAND...SO REFLECTED THIS IN THE LATEST FORECAST. SUNDAY IS MAINLY EXPECTED TO BE A COOL AND WINDY DAY. THERE WILL BE INCREASING ENE WINDS WITH THE STRONGEST WINDS DOWNWIND OF LAKE SUPERIOR...WHERE GUSTS OF 25 TO 35 MPH ARE POSSIBLE. TEMPERATURES WILL ONLY REACH THE LOWER 40S NEAR LAKE SUPERIOR...BUT MORE INLAND AREAS SHOULD REACH THE 50S. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 330 PM CDT SAT MAY 9 2015 FOCUS IN EXTENDED ON THE COOL TEMPERATURES AND SNOW CHANCES AS A CUT OFF LOW TRACKS OUT OF THE DAKOTAS SUNDAY NIGHT...AND MIGRATES SLOWLY ACROSS MINNESOTA/WESTERN LAKE SUPERIOR MONDAY/MONDAY NIGHT. THE LOW WILL BRING A PROLONGED PERIODS OF RAIN...AND ISOLATED THUNDER. HAVE CONTINUED TO CARRY HIGH/DEFINITE POPS SUNDAY NIGHT THROUGH MONDAY NIGHT. AT THIS TIME...THE HEAVIEST RAINFALL IS EXPECTED ACROSS THE IRON RANGE/ARROWHEAD REGION OF NORTHEAST MN...WITH TOTALS THROUGH TUESDAY OF AROUND INCH. MODELS ARE IN GOOD AGREEMENT THAT BELOW ZERO H85 TEMPS WRAP AROUND THE BACK SIDE OF THE LOW MONDAY...SPREADING OVER THE NORTHLAND MONDAY NIGHT AND TUESDAY. THIS WILL BRING A CHANCE OF SNOW OR A RAIN/SNOW MIX FOR THE MONDAY NIGHT AND TUESDAY PERIODS. LATEST NAM/GFS BUFR SOUNDINGS AT KELO AND KHIB SHOW DEEPLY SATURATED LOW AND MID LEVELS...PWATS AROUND 3/4 OF AN INCH...AND TEMP PROFILES JUST ABOVE THE SFC REMAINING WELL BELOW THE ZERO ISOTHERM. ALTHOUGH A PERIOD OF SNOW IS EXPECTED...AND SOME ACCUMULATION WILL BE POSSIBLE IN THE MN ARROWHEAD/SOUTH SHORE REGION...MOST LOCATIONS CAN EXPECT THE SNOW TO MELT AS IT REACHES THE GROUND WITH ONLY ACCUMULATION ON ELEVATED SURFACES. HAVE INCREASED POPS TUESDAY ABOVE THE SUPERBLEND GUIDANCE AS STEEP LAPSE RATES...AROUND 100 J/KG OF CAPE...AND WRAP AROUND MOISTURE WILL SUPPORT A TYPICAL POST-LOW DAY OF INSTABILITY SHOWERS. THE SHOWERS WILL LIKELY MIX WITH SNOW DURING THE MORNING HOURS...CHANGING TO ALL RAIN IN THE AFTERNOON...WITH LIGHT QPF ON THE ORDER OF A FEW HUNDREDTHS. THE EXCEPTION IS ALONG THE GOGEBIC RANGE IN NRN WISCONSIN WHERE TEMPERATURES WILL BE COOLER AND THE RAIN/SNOW MIX MAY PERSIST THROUGH THE EVENING. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1227 AM CDT SUN MAY 10 2015 AN AREA OF LOW PRESSURE WILL TRACK NORTHEASTWARDS TONIGHT FROM EASTERN COLORADO THROUGH NEBRASKA...AND INTO SOUTHWEST MINNESOTA BY MONDAY MORNING. DURING THIS TIMEFRAME HIGH PRESSURE WILL BUILD OVER NORTHERN ONTARIO. AS A RESULT A TIGHT PRESSURE GRADIENT WILL DEVELOP OVER THE FORECAST AREA...WHICH WILL RESULT IN GUSTY EASTERLY AND NORTHEASTERLY WINDS. GUSTY CONDITIONS ARE EXPECTED TO PERSIST THROUGH MONDAY WITH THE HIGHEST GUSTS APPROACHING 40 KTS AT KDLH. LATEST 00Z GUIDANCE AND HRRR TRENDS SHOW PRECIPITATION MOVE IN THE VICINITY OF KINL. AS A RESULT...BROUGHT VCSH INTO KINL BETWEEN 11Z-16Z. EXPECT PRECIPITATION ASSOCIATED WITH THE WARM FRONT FROM THE LOW TO MOVE IN BETWEEN 18Z AND 01Z...AFFECTING THE KBRD SITE FIRST AND SPREADING NORTHEASTWARDS TO OTHER TERMINALS. VFR CONDITIONS EXPECTED AT KHYR AND KINL THROUGH THE FORECAST PERIOD...HOWEVER MVFR CIGS POSSIBLE AT KHYR AFTER 02Z...BUT NOT CONFIDENT DUE TO DRIER AIR IN LOWER LEVELS. ALL OTHER TERMINALS WILL SEE MVFR CONDITIONS DEVELOP BETWEEN 22Z-01Z. KDLH AND KHIB MAY SEE IFR CIGS LATE IN THE PERIOD...BUT NOT CONFIDENT ON THE TIMING. KBRD WILL SEE IFR CIGS DEVELOP 01Z. && .PRELIMINARY POINT TEMPS/POPS... DLH 38 41 36 47 / 100 80 70 40 INL 37 40 34 50 / 80 90 70 40 BRD 39 49 37 52 / 90 70 60 30 HYR 45 54 35 48 / 90 60 60 50 ASX 40 41 35 43 / 80 70 60 50 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...GALE WARNING FROM 10 AM THIS MORNING TO 7 PM CDT MONDAY FOR LSZ121-140>148. && $$ UPDATE...LE/GSF/GSF SHORT TERM...GROCHOCINSKI LONG TERM...GRANING AVIATION...WL/LE
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
433 PM CDT Sun May 10 2015 .SHORT TERM: (Through Late Tonight) Issued at 431 PM CDT Sun May 10 2015 Have heavily leaned towards the afternoon runs of the HRRR for convective trends heading into the early evening hours. N-S band of convection is plowing east at 40-45 kts, and will likely be exiting eastern sections of our CWA shortly after 00z. After an early evening lull in activity convection should then return to the CWA...with threat likely a combination of the activity now increasing along cold front over eastern KS as well as convection redeveloping just north of Red River. Believe that this SE OK activity will be the dominate convection for our area overnight, as current activity will be intensifying the low level boundary draped across the ARKLATEX, with this dome of rain-cooled air providing lift to increasing low level jet that will be transporting very moist air into the region from the southern Plains. This area will also be in a favorable area of upper level divergence tied to RRQ of upper level jet. Once current line of convection exits area, uncertain about additional severe weather potential overnight. Current activity as well as latest upstream convection will be putting a big bite in the instability that will be available, although large scale shear of 30-50kts still certainly suggests some severe weather potential. In addition...while some decent rainfalls are likely over southern sections of the CWA, believe the aforementioned outflow boundary will keep the heaviest rain threat anchored over AR...and south of our CWA. Truett .LONG TERM: (Monday through Next Sunday) Issued at 431 PM CDT Sun May 10 2015 Convection should press east and exit the region during the day on Monday as cold front pushes across the CWA. I`ve held onto much higher PoPs than guidance for the early part of the morning on the western edge of the expected precip shield (generally from near Cuba thru STL to near Carlinville), but then quickly wind them down to the SE of STL during the late morning and early afternoon hours. Any severe weather potential will be strongly tied to morning convection trends, but SWODY2 still looks reasonable that greatest threat will be in our far southeast counties, where the AMS will stand at least some chance of destabililzing before fropa occurs. As unseasonably strong upper level low spins its way across the Great Lakes Monday night and Tuesday, it will drag much cooler air into the area. This should result in a dry Tuesday with temps a bit below average, as highs will primarily be in the 60s. Ridging in the wake of the departing low will mean more tranquil weather by midweek, with temperatures moderating into the 70s. Another upper level system will mean a return of unsettled weather heading into the latter half of the week. There is a large discrepency in the medium range solutions regarding the location and movement of this feature especially heading into next weekend, but with all solutions suggesting a frontal boundary remaining over the area forecast will mention a chance of thunderstorms in most areas during the Thursday-Sunday time frame. Truett && .AVIATION: (For the 18z TAFs through 18z Monday Afternoon) Issued at 1222 PM CDT Sun May 10 2015 Line of thunderstorms will reach KCOU by around 20Z, then KSTL by 22Z. Expect thunder threat to last about 2 hours, but limited instability will preclude widespread threat of any severe weather. Latest model runs continue to show an area of rain, with little to no thunder expected, will form overnight and move through the TAF sites until around 12Z. Ceilings may drop to 2000 feet as rain ends early Monday morning. Ceilings will then improve as drier air moves in and winds back to westerly by late Monday morning. Specifics for KSTL: VFR conditions until around 22Z when an line of thunderstorms will move through KSTL. Thunder threat will last about 2 hours, then an area of rain will move in overnight. No appreciable instability with this area of rain, so thunder threat is small. Rain will likely end by around 12Z Monday. Ceilings may drop to around 2000 feet as the rain ends, however winds will continue to back, bringing in a drier airmass which will help ceilings lift and scatter out by 18Z Monday. Browning && .PRELIMINARY POINT TEMPS/POPS: Saint Louis 66 74 52 69 / 80 80 5 0 Quincy 61 68 46 65 / 70 30 5 0 Columbia 57 69 47 68 / 70 20 5 0 Jefferson City 58 71 47 69 / 70 20 5 0 Salem 68 76 53 68 / 90 80 10 0 Farmington 63 75 50 69 / 80 80 10 0 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1237 PM CDT Sun May 10 2015 .SHORT TERM: (Through Late This Afternoon) Issued at 355 AM CDT Sun May 10 2015 Warm front just north of the I-70 corridor will continue advancing slowly northward this morning and should be well north of the forecast area into Iowa and northern Illinois by 17-18Z. Deep moisture combined with another passing MCV and low level warm advection will continue to produce scattered showers and the occasional thunderstorm this morning. The primary shortwave over northeast Colorado is finally moving, opening up, and being drawn up into the mean flow. Should see the surface low associated with the wave tighten up and move from western Kansas into northeast Nebraska or northwest Iowa by early evening. Short range guidance suggests there will be another wave of rain and thunderstorms this afternoon well ahead of the cold front, probably triggered by another MCV generated by the convection now occurring over central Texas. NAM and RAP produce 2000-2700 J/Kg of CAPE this afternoon in the warm sector across the area for this MCV to work with. Add in 40+ kts of 0-6km shear and severe thunderstorms look more likely today than the past couple of days. Not sure what the mode of thunderstorm development will ultimately be, but would a few discrete rotating storms will be possible before everything congeals into clusters or broken lines. Carney .LONG TERM: (Tonight through Saturday) Issued at 355 AM CDT Sun May 10 2015 Southwest flow aloft will persist for much of this period, only ending when the main TROF ejects thru our region. Thrown into the mix will be a general southerly flow at the surface, well above normal levels of moisture thru the column for early May, and a series of upper level disturbances ejecting from a wound up storm system currently over the central High Plains. This will yield high PoPs thru Monday. Severe storm potential still on track today and tonight, with the best timeframe from mid-afternoon into mid-evening as better bulk shear enters the fray during this time and there should still be enough instability to create the conditional risk with a good synoptic signal to also trigger widespread convection intiation from the west with this beginning entering our CWA during this time. The highest risk locations in our CWA will be to the west of STL metro--in northeast and central MO. Outside of these locations and times, this does not necessarily preclude severe wx occurrence. Monday continues to look marginal on severe for our area, with the highest risk locations being where the surface cold front will be as things start to heat up for the day and this should be just east of STL metro. The best timeframe for our CWA is a bit more sped up--late morning and early afternoon--and this accounts for SPC`s push of the main severe threat further east. A localized heavy rainfall threat also continues thru Monday in this favorable synoptic pattern, and indeed, localized heavy rainfall has already occurred in spots scattered across our CWA, with these spots rather small in coverage and between 2-3" over a 3-day period. No FFA issuance with this package but the beginnings of a clearer signal and focus are coming into play tonight and Monday morning to perhaps justify one eventually but would like to see a bit more favorable antecedent conditions (i.e. more rainfall today) before this occurs as current QPF not enough to make up for this. Preferred the higher MOS temps on Monday with SW flow and what should be afternoon clearing, but if the rain and thicker clouds are slower to exit, will need to chop the temps down by about 5 degrees. For Tuesday and Wednesday, we will see NW flow initially transition to a building RIDGE overhead from the southeast CONUS. The much drier column and lack of upper level disturbances or surface fronts will give us a rare two-day dry period. Temps should actually be a bit below average with cool nighttime mins in the 40s. The RIDGE aloft on Thursday will then gradually transition back to an active SW flow aloft pattern for next weekend. While there remain model discrepancies during this period, it looks to be one where at least Climo PoPs [25-30%] are justified and more with general agreement on moisture return and lifting mechanisms. Temps will make a return back to average or even above average during this time. TES && .AVIATION: (For the 18z TAFs through 18z Monday Afternoon) Issued at 1222 PM CDT Sun May 10 2015 Line of thunderstorms will reach KCOU by around 20Z, then KSTL by 22Z. Expect thunder threat to last about 2 hours, but limited instability will preclude widespread threat of any severe weather. Latest model runs continue to show an area of rain, with little to no thunder expected, will form overnight and move through the TAF sites until around 12Z. Ceilings may drop to 2000 feet as rain ends early Monday morning. Ceilings will then improve as drier air moves in and winds back to westerly by late Monday morning. Specifics for KSTL: VFR conditions until around 22Z when an line of thunderstorms will move through KSTL. Thunder threat will last about 2 hours, then an area of rain will move in overnight. No appreciable instability with this area of rain, so thunder threat is small. Rain will likely end by around 12Z Monday. Ceilings may drop to around 2000 feet as the rain ends, however winds will continue to back, bringing in a drier airmass which will help ceilings lift and scatter out by 18Z Monday. Browning && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
714 AM CDT Sun May 10 2015 .SHORT TERM: (Through Late This Afternoon) Issued at 355 AM CDT Sun May 10 2015 Warm front just north of the I-70 corridor will continue advancing slowly northward this morning and should be well north of the forecast area into Iowa and northern Illinois by 17-18Z. Deep moisture combined with another passing MCV and low level warm advection will continue to produce scattered showers and the occasional thunderstorm this morning. The primary shortwave over northeast Colorado is finally moving, opening up, and being drawn up into the mean flow. Should see the surface low associated with the wave tighten up and move from western Kansas into northeast Nebraska or northwest Iowa by early evening. Short range guidance suggests there will be another wave of rain and thunderstorms this afternoon well ahead of the cold front, probably triggered by another MCV generated by the convection now occurring over central Texas. NAM and RAP produce 2000-2700 J/Kg of CAPE this afternoon in the warm sector across the area for this MCV to work with. Add in 40+ kts of 0-6km shear and severe thunderstorms look more likely today than the past couple of days. Not sure what the mode of thunderstorm development will ultimately be, but would a few discrete rotating storms will be possible before everything congeals into clusters or broken lines. Carney .LONG TERM: (Tonight through Saturday) Issued at 355 AM CDT Sun May 10 2015 Southwest flow aloft will persist for much of this period, only ending when the main TROF ejects thru our region. Thrown into the mix will be a general southerly flow at the surface, well above normal levels of moisture thru the column for early May, and a series of upper level disturbances ejecting from a wound up storm system currently over the central High Plains. This will yield high PoPs thru Monday. Severe storm potential still on track today and tonight, with the best timeframe from mid-afternoon into mid-evening as better bulk shear enters the fray during this time and there should still be enough instability to create the conditional risk with a good synoptic signal to also trigger widespread convection intiation from the west with this beginning entering our CWA during this time. The highest risk locations in our CWA will be to the west of STL metro--in northeast and central MO. Outside of these locations and times, this does not necessarily preclude severe wx occurrence. Monday continues to look marginal on severe for our area, with the highest risk locations being where the surface cold front will be as things start to heat up for the day and this should be just east of STL metro. The best timeframe for our CWA is a bit more sped up--late morning and early afternoon--and this accounts for SPC`s push of the main severe threat further east. A localized heavy rainfall threat also continues thru Monday in this favorable synoptic pattern, and indeed, localized heavy rainfall has already occurred in spots scattered across our CWA, with these spots rather small in coverage and between 2-3" over a 3-day period. No FFA issuance with this package but the beginnings of a clearer signal and focus are coming into play tonight and Monday morning to perhaps justify one eventually but would like to see a bit more favorable antecedent conditions (i.e. more rainfall today) before this occurs as current QPF not enough to make up for this. Preferred the higher MOS temps on Monday with SW flow and what should be afternoon clearing, but if the rain and thicker clouds are slower to exit, will need to chop the temps down by about 5 degrees. For Tuesday and Wednesday, we will see NW flow initially transition to a building RIDGE overhead from the southeast CONUS. The much drier column and lack of upper level disturbances or surface fronts will give us a rare two-day dry period. Temps should actually be a bit below average with cool nighttime mins in the 40s. The RIDGE aloft on Thursday will then gradually transition back to an active SW flow aloft pattern for next weekend. While there remain model discrepancies during this period, it looks to be one where at least Climo PoPs [25-30%] are justified and more with general agreement on moisture return and lifting mechanisms. Temps will make a return back to average or even above average during this time. TES && .AVIATION: (For the 12z TAFs through 12z Monday Morning) Issued at 644 AM CDT Sun May 10 2015 A warm front is lifting slowly northward across the area. Surface analysis from 11Z suggests the front was just south of a line from KMBY to KPPQ, but just north of KIJX and KSPI. Front will continue moving north this morning as low pressure strengthens and becomes more organized over the Great Plains. IFR flight conditions will continue to prevail along and north of the front this morning across northern Missouri into west central Illinois, with ceilings and visibilities improving to VFR as the wind shifts to the south after FROPA. Widely scattered showers will be possible almost any time today, but more widespread showers and thunderstorms are likely later this afternoon into the evening as another disturbance moves across the area. Some of the storms this afternoon and evening could be strong or severe producing wind gusts in excess of 50kts and large hail. Unsure how the rest of the forecast period will play out. Think the most likely scenario is lingering marginal cigs/vsbys with periods of showers and thunderstorms continuing tonight. Think the most likely areas for rain and storms will be along and south of I-70. Specifics for KSTL: Warm front is north of the terminal at this time, so low ceiling/visibility threat should be much diminished at Lambert for the time being. Cannot rule out a passing shower just about any time through early afternoon, but expect there will be far more dry time than precipitation. Latest short-range guidance suggests that the best chance for rain/thunderstorms will be mid to late afternoon (probably after 20Z) as another disturbance moves over our area from the southwest. There is a chance that the storms could be severe with wind in excess of 50kts and/or large hail. Unsure how the rest of the forecast period will play out. Think the most likely scenario is lingering marginal cigs/vsbys with periods of showers and thunderstorms continuing tonight. Think the most likely areas for rain and storms will be along and south of I-70. The cold front looks to move through the terminal mid to late Monday morning; this will finally bring an end to the recent bout of unsettled weather. Carney && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
355 AM CDT Sun May 10 2015 .SHORT TERM: (Through Late This Afternoon) Issued at 355 AM CDT Sun May 10 2015 Warm front just north of the I-70 corridor will continue advancing slowly northward this morning and should be well north of the forecast area into Iowa and northern Illinois by 17-18Z. Deep moisture combined with another passing MCV and low level warm advection will continue to produce scattered showers and the occasional thunderstorm this morning. The primary shortwave over northeast Colorado is finally moving, opening up, and being drawn up into the mean flow. Should see the surface low associated with the wave tighten up and move from western Kansas into northeast Nebraska or northwest Iowa by early evening. Short range guidance suggests there will be another wave of rain and thunderstorms this afternoon well ahead of the cold front, probably triggered by another MCV generated by the convection now occurring over central Texas. NAM and RAP produce 2000-2700 J/Kg of CAPE this afternoon in the warm sector across the area for this MCV to work with. Add in 40+ kts of 0-6km shear and severe thunderstorms look more likely today than the past couple of days. Not sure what the mode of thunderstorm development will ultimately be, but would a few discrete rotating storms will be possible before everything congeals into clusters or broken lines. Carney .LONG TERM: (Tonight through Saturday) Issued at 355 AM CDT Sun May 10 2015 Southwest flow aloft will persist for much of this period, only ending when the main TROF ejects thru our region. Thrown into the mix will be a general southerly flow at the surface, well above normal levels of moisture thru the column for early May, and a series of upper level disturbances ejecting from a wound up storm system currently over the central High Plains. This will yield high PoPs thru Monday. Severe storm potential still on track today and tonight, with the best timeframe from mid-afternoon into mid-evening as better bulk shear enters the fray during this time and there should still be enough instability to create the conditional risk with a good synoptic signal to also trigger widespread convection intiation from the west with this beginning entering our CWA during this time. The highest risk locations in our CWA will be to the west of STL metro--in northeast and central MO. Outside of these locations and times, this does not necessarily preclude severe wx occurrence. Monday continues to look marginal on severe for our area, with the highest risk locations being where the surface cold front will be as things start to heat up for the day and this should be just east of STL metro. The best timeframe for our CWA is a bit more sped up--late morning and early afternoon--and this accounts for SPC`s push of the main severe threat further east. A localized heavy rainfall threat also continues thru Monday in this favorable synoptic pattern, and indeed, localized heavy rainfall has already occurred in spots scattered across our CWA, with these spots rather small in coverage and between 2-3" over a 3-day period. No FFA issuance with this package but the beginnings of a clearer signal and focus are coming into play tonight and Monday morning to perhaps justify one eventually but would like to see a bit more favorable antecedent conditions (i.e. more rainfall today) before this occurs as current QPF not enough to make up for this. Preferred the higher MOS temps on Monday with SW flow and what should be afternoon clearing, but if the rain and thicker clouds are slower to exit, will need to chop the temps down by about 5 degrees. For Tuesday and Wednesday, we will see NW flow initially transition to a building RIDGE overhead from the southeast CONUS. The much drier column and lack of upper level disturbances or surface fronts will give us a rare two-day dry period. Temps should actually be a bit below average with cool nighttime mins in the 40s. The RIDGE aloft on Thursday will then gradually transition back to an active SW flow aloft pattern for next weekend. While there remain model discrepancies during this period, it looks to be one where at least Climo PoPs [25-30%] are justified and more with general agreement on moisture return and lifting mechanisms. Temps will make a return back to average or even above average during this time. TES && .AVIATION: (For the 06z TAFs through 06z Sunday Night) Issued at 1153 PM CDT Sat May 9 2015 Band of light SHRA will continue moving nwd, but continue to break up and may not reach UIN, those shud reach STL/SUS/CPS. FG may develop tonight, but with extensive cloud cover across the region, do not anticipate anything below MVFR. Expect most of Sun to be dry with TSRA approaching the region during the late afternoon into evening hours. && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1212 AM CDT Sun May 10 2015 .SHORT TERM...(This Evening through Sunday) Issued at 305 PM CDT SAT MAY 9 2015 Thunderstorm chances will increase through this evening and tonight as a 50-60kt low level jet sets up along the MO/KS border and overruns the stationary boundary near the I-44 corridor. Large amounts of more moist air will spread into the region ahead of a shortwave trough currently over central OK. Short term forecast progs show K-index values around 40, well over the baseline of 30 generally needed for heavy rainfall. We`re also seeing tall and skinny CAPE on RUC forecast soundings. With fairly saturated soils from previous two nights of rainfall, will be issuing a Flash Flood Watch for areas along and west of an Osceola to Cassville to Gainesville line through 1 AM Monday. Later shifts may need to modify areal coverage and timing. Severe storm threat will remain on the lower end for hail and straight line winds, but not zero. Better instability and more favorable vertical wind shear for rotating storms will remain to our west, in closer proximity to the main upper low pressure system over the four corners region. With better instability and upper level dynamics ahead of the upper low which finally ejects to the northeast into the central Plains, severe threat will be higher on Sunday afternoon/evening. .LONG TERM...(Sunday Night through Saturday) Issued at 305 PM CDT SAT MAY 9 2015 As the upper low continues to shift northward into the upper Midwest, a cold front will finally push east of the region Monday morning and bring a much drier and slightly cooler air mass into the MO Ozarks/SE KS. We may see a few lingering showers over our far eastern counties, so will keep storms in the forecast east of a Warsaw to Cassville line through the morning, and east of a Rolla to Gainesville line through the afternoon. Surface high pressure will remain over the region through Wednesday before another lee side trough sets up over the southern Rockies ahead of an upper low moving into the southern CA coast late next week. So expect increasingly stormy conditions from late next week into the weekend. && .AVIATION...(For the 06Z TAFS through 06Z Sunday Night) Issued at 1203 AM CDT SUN MAY 10 2015 For the KSGF/KJLN/KBBG tafs: Periods of showers and tstms will occur during the taf period. Hard to pinpoint timing but used a mix of the high resolution models and then increased chances for precip late in the taf period with the approach of a sfc front. Expect a period of MVFR/IFR conditions at times with lower ceilings and/or fog toward 12z and with any heavier showers. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...FLASH FLOOD WATCH through late tonight FOR MOZ066-067-077-078- 088-089-093>095-101>105. KS...FLASH FLOOD WATCH through late tonight FOR KSZ073-097-101. && $$ SHORT TERM...Terry LONG TERM...Terry AVIATION...DSA
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
908 PM MDT MON MAY 11 2015 .DISCUSSION... UPDATE FORTHCOMING. SOUTHWEST FLOW ALOFT CONTINUES TO BRING MOISTURE AND INSTABILITY TO SOUTHWEST MONTANA WHERE SCATTERED SHOWERS SHOULD CONTINUE THROUGH THE NIGHT. BOTH THE HRRR AND RUC ANALYSIS BRING SHOWERS AS FAR NORTH AS JUST ABOUT GREAT FALLS BY 12Z. TEMPERATURES OVERNIGHT LOOK ON TRACK. && .AVIATION... UPDATED 0020Z. INCREASING SOUTHWEST FLOW ALOFT CONTINUES TO BRING MOISTURE AND INSTABILITY TO THE AREA. SCATTERED SHOWERS WILL PERSIST OVERNIGHT OVER SOUTHWEST MONTANA WITH DRY CONDITIONS ELSEWHERE. SHOWERS AND ISOLATED THUNDERSTORMS WILL SPREAD SLOWLY NORTH AND EAST AFTER 18Z. VFR CONDITIONS PREVAIL WITH MVFR CONDITIONS IN THE VICINITY OF SHOWERS AND THUNDERSTORMS ALONG WITH ERRATIC GUSTY WINDS. && .PREV DISCUSSION...ISSUED 259 PM MDT MON MAY 11 2015 MONDAY THROUGH WEDNESDAY...CONDITIONS WILL GENERALLY CHANGE TO A WETTER PATTERN THROUGH THE MIDDLE OF THE WEEK AS SHORTWAVE TROUGHS MOVE ONSHORE AND BEGIN TO BRING MOISTURE INTO THE REGION. SOME SHOWERS OVER THE HIGHER TERRAIN WILL BE POSSIBLE THIS EVENING AS THE FIRST SHORTWAVE MOVES INTO THE AREA. PRECIPITATION WILL BE LIMITED WITH THIS SYSTEM WITH MOST OF THE SHOWERS OCCURRING OVER THE ROCKY MOUNTAIN FRONT. THE NEXT SYSTEM WILL BEGIN TO MOVE INTO MONTANA TUESDAY NIGHT AND SHOULD BRING AN INCREASE IN SHOWERS AND THUNDERSTORMS TO THE AREA TUESDAY AFTERNOON AND EVENING. THIS EVENT LOOKS LIKE IT SHOULD BRING MORE WIDESPREAD PRECIPITATION TO THE AREA AS THE MOVES ACROSS THE STATE WEDNESDAY. PRECIPITATION IS EXPECTED TO DECREASE WEDNESDAY AFTERNOON AND EVENING. TEMPERATURES SHOULD COOL OFF TUESDAY AND WEDNESDAY BACK BELOW SEASONAL AVERAGES. SUK WEDNESDAY NIGHT THROUGH MONDAY. AT THIS TIME, FORECAST CONFIDENCE IS LOW FOR MUCH OF THIS PERIOD AS PRIMARY FORECAST MODELS NOT SHOWING MUCH CONSENSUS, ESPECIALLY ON PRECIPITATION COVERAGE AND AMOUNTS. THE MODEL DIFFERENCES CENTER ON THE EVOLUTION OF A BROAD SHORTWAVE TROF THAT WILL BE OFF THE CALIFORNIA COAST ON THURSDAY. MODELS ARE IN GENERALLY GOOD AGREEMENT THAT THE TROF WILL MAKE SLOW EASTWARD PROGRESS AND BE CENTERED OVER THE GREAT BASIN/DESERT SOUTHWEST BY LATE FRIDAY. PLUMES OF MOISTURE STREAMING NORTHWARD AHEAD OF THE TROF AXIS WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS INTO MT BY THURS AFTN CONTINUING THRU FRIDAY, WITH THE ECMWF MODEL INDICATING MUCH WIDER PRECIP COVERAGE OVER CENTRAL/SOUTHWEST MT. THINGS GET MORE COMPLICATED OVER THE WEEKEND AS THE TROF LIFTS NORTHEASTWARD TOWARD THE CENTRAL ROCKIES. BOTH THE GFS AND EC MODELS SHIFT OUR WINDS ALOFT TO EASTERLY AS THE TROF PASSES TO OUR SOUTH, SETTING UP THE POSSIBILITY OF PULLING EXTENSIVE GULF OF MEXICO MOISTURE THROUGH THE UPPER MIDWEST AND INTO THE TREASURE STATE ON BOTH SAT/SUN. THE EC IS NOTABLY STRONGER WITH THIS LONG MOISTURE FETCH, DRIVEN MAINLY BY A CLOSED MID-LEVEL LOW PRESSURE AREA WITHIN THE TROF, WHEREAS THE GFS INDICATES AN OVERALL WEAKER TROF WITH LESS MOISTURE OVER OUR REGION. IN FACT, THE GFS HAS MUCH OF THE TROF AND PRECIPITATION OUT OF OUR AREA BY SUNDAY MORNING WHILE THE EC PAINTS EXTENSIVE RAINFALL WITH AMOUNTS RANGING FROM 0.1 INCH ALONG THE HI-LINE TO 0.5-0.75 INCH FROM GREAT FALLS SOUTHWARD TO THE IDAHO BORDER. GIVEN THE TROUBLESOME MODEL DIFFERENCES, THE CURRENT EXTENDED FORECAST LARGELY RELIES ON CLIMATOLOGICAL PRECIP PROBABILITIES (MOSTLY 30-40%) FOR SATURDAY AND EARLY SUNDAY, THEN REDUCES RAINFALL CHANCES SUN EVE INTO MONDAY AS THE TROF HEADS TOWARD THE GREAT LAKES STATES. THE GOOD NEWS IS THAT IT LOOKS THAT MOST/ALL OF THE FORECAST AREA SHOULD RECEIVE SOME NEEDED RAINFALL THIS WEEKEND; WE`LL JUST HAVE TO WAIT FOR ADDITIONAL MODEL OUTPUT TO GET A BETTER ESTIMATE ON AMOUNTS. AS FOR TEMPERATURES, THEY WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL VALUES THROUGH THE LATTER HALF OF THE WEEK, WITH HIGHS IN THE MID- AND UPPER 60S EACH DAY. WARANAUSKAS && .PRELIMINARY POINT TEMPS/POPS... GTF 36 60 41 59 / 10 20 30 60 CTB 30 56 35 51 / 10 10 20 70 HLN 40 61 41 65 / 30 30 40 50 BZN 38 60 38 66 / 20 20 50 40 WEY 30 62 31 61 / 30 40 40 30 DLN 41 62 41 67 / 20 40 50 40 HVR 33 63 36 59 / 10 10 20 60 LWT 37 59 39 63 / 20 20 30 50 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
847 PM MDT MON MAY 11 2015 .UPDATE... ENERGY MOVING THROUGH IDAHO PUSHING MOISTURE INTO SOUTHWEST MONTANA BUT DOWNSTREAM SHORTWAVE RIDGING IS INFLUENCING THE WEATHER OVER SOUTH CENTRAL MONTANA. RAP IS CONSISTENTLY KEEPING THE MOISTURE ON THE WEST SIDE OF THIS SHORTWAVE RIDGE AXIS OVERNIGHT. HAVE SCALED BACK CHANCES OF PRECIPITATION WESTWARD FOR THE OVERNIGHT PERIOD. BORSUM && .SHORT TERM...VALID FOR TUE AND WED... AFTER A NICE START TO THE WORK WEEK TODAY...WE ARE ANTICIPATING A TRANSITION TO A MUCH MORE UNSETTLED PATTERN THE REST OF THE WEEK. INVERTED SURFACE TROUGH FROM THE WEST ASSOCIATED WITH AN UPPER MINI CUT LOW OVER THE OREGON COAST WILL MEAN AN INCREASING CHANCE OF SHOWERS OVER THE MOUNTAINS THIS EVENING...SPREADING EAST OVERNIGHT. THAT UPPER CUT OFF LOW TRACKS INLAND TUESDAY RESULTING IN DIFFLUENT FLOW OVER OUR REGION WITH A GOOD SOURCE OF PACIFIC MOISTURE INTO OUR FORECAST AREA AS WELL. SO BUMPED UP POPS IN OUR WEST MOUNTAINS. ENERGY TRACKS NORTH INTO CANADA BY TUESDAY NIGHT WITH A BRIEF DRYING TREND IN ITS WAKE. HOWEVER...AS MORE ENERGY DROPS INTO THE TROUGH ON THE WEST COAST WE WILL SEE SW FLOW ALOFT BRING SCATTERED PRECIPITATION INTO OUR REGION THROUGH WEDNESDAY NIGHT. MODELS ARE SIMILAR WITH THE OVERALL PATTERN...BUT TEND TO HAVE SOME CONVECTIVE FEEDBACK AND DETAILS THAT MESS WITH QPF FIELDS. BASICALLY USED A SMOOTHED OUT BLEND OF PROGGS FOR THE POPS. LOOK FOR SLIGHTLY COOLER AFTERNOON HIGHS TUESDAY...FOLLOWED BY MILD SEASONAL TEMPS FOR WEDNESDAY. BT .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... MODELS...ANALOGS AND ENSEMBLES WERE LENDING INCREASING CONFIDENCE TO A PROGRESSIVELY UNSETTLED PATTERN INTO NEXT WEEKEND. AN UPPER LOW OFF THE CA COAST ON THU WILL MOVE INLAND ON FRI. WEAK ENERGY...WARM ADVECTION AND MOISTURE WILL MOVE N THROUGH THE AREA ON THU BRINGING A SLIGHT CHANCE OF SHOWERS THROUGH THU NIGHT...WITH A FEW AFTERNOON AND EVENING THUNDERSTORMS. CHANCES FOR THUNDERSTORMS LOOKED HIGHER ON FRI AS THE UPPER LOW MOVES INTO WY BRINGING MORE DYNAMICS AND UNSTABLE AIR. THESE FACTORS WILL COMBINE WITH AREAS OF HIGHER BULK SHEAR TO PRODUCE A FEW STRONG THUNDERSTORMS. TEMPERATURES WILL BE SEASONABLE BOTH DAYS. THE UPPER LOW WILL PROGRESS ENE THROUGH THE REGION ON SAT AND REACH THE DAKOTAS ON SUN. WRAP-AROUND MOISTURE WILL AFFECT THE REGION THROUGH SUN AND THE MODELS AGREED ON POTENTIAL HEAVY RAINFALL FOR THE AREA BEGINNING FRI NIGHT. COLDER AIR GETS PULLED INTO THE REGION FROM THE N ON SUN THROUGH EARLY MON. RAISED POPS FURTHER FOR FRI NIGHT INTO SUN. SOME SNOW COULD MIX WITH THE RAIN OVER SE MT SUN NIGHT INTO MON. MODELS HAD THE PRECIPITATION TAPERING OFF SUN NIGHT. HIGHS WILL BE IN THE 50S ON THE WEEKEND WITH THE POTENTIAL TO BE LOWER DUE TO THE PRECIPITATION. ARTHUR && .AVIATION... SHOWERS WILL INCREASE OVERNIGHT AND TUESDAY MORNING AS A WAVE OF ENERGY ALOFT CROSSES THE REGION. CONFIDENCE IN SHOWERS AND MVFR- TYPE CEILINGS IS GREATEST IN THE KLVM AREA IN CLOSE PROXIMITY TO THE WAVE. THE 00 UTC TAFS ONLY ADVERTISED VCSH AT KBIL AND KMLS DUE TO LOW CONFIDENCE IN MORE THAN BRIEF...VERY LIGHT SHOWERS AT THOSE TERMINALS GIVEN AN INITIALLY-DRY NEAR-SURFACE LAYER. AREAS OF MOUNTAIN OBSCURATION ARE ALSO EXPECTED THROUGH TUESDAY. SCHULTZ && .PRELIMINARY POINT TEMP/POPS... TUE WED THU FRI SAT SUN MON ----------------------------------------------------------- BIL 041/061 043/068 044/063 046/065 047/057 044/052 040/058 24/T 33/T 32/W 34/T 56/W 65/W 42/W LVM 036/059 038/066 038/063 041/064 042/056 042/054 036/058 45/T 53/T 33/T 34/T 56/W 65/W 42/W HDN 038/066 041/071 043/066 045/068 047/060 044/053 038/061 14/T 32/T 32/W 24/T 56/W 65/W 42/W MLS 038/064 041/067 043/062 045/069 049/062 044/053 039/059 12/W 31/E 23/W 24/T 56/W 65/W 52/W 4BQ 034/063 037/066 044/063 046/068 049/060 045/049 037/056 03/W 21/E 32/W 24/T 55/W 55/W 53/W BHK 032/058 036/060 040/058 043/065 046/060 044/053 034/056 01/E 22/W 43/W 24/T 55/W 55/W 53/W SHR 033/064 038/068 040/065 043/067 044/058 041/050 035/056 12/T 32/T 32/T 34/T 45/W 56/W 63/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
615 AM CDT SUN MAY 10 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 350 AM CDT SUN MAY 10 2015 ...LOCATION OF SEVERE STORMS TODAY IS THE MAIN CHALLENGE... EXCEPTIONALLY ACTIVE/DYNAMIC PATTERN CONTINUES OVER THE CENTRAL UNITED STATES TODAY AS LARGE UPPER LOW SPINS OVER THE HIGH PLAINS. WATER VAPOR IMAGERY SHOWED THE CLOSED AND WRAPPED UP CIRCULATION DRIFTING NORTHEAST AROUND 30 KNOTS...OUT OF NORTHEAST COLORADO AND HEADED FOR NORTHWEST NEBRASKA THIS MORNING. A COMPLEX AND HIGHLY BAROCLINIC SURFACE PATTERN WAS ANALYZED AT 06Z WITH A CLOSED 1004MB LOW NEAR THE KANSAS-COLORADO BORDER AND A TIGHT THERMAL AND PRESSURE GRADIENT NORTH OF THE LOW. WARM FRONT EXTENDED FROM THE LOW EASTWARD WITH LOW TO MID 60S DEW POINTS OVER KANSAS...AND AN INVERTED TROF EXTENDED NORTHEAST INTO THE SIOUX CITY AREA. AIRMASS NORTH OF THE LOW WAS COLD ENOUGH FOR WIDESPREAD SNOW IN THE WESTERN HIGH PLAINS THIS MORNING. AS THIS PATTERN EVOLVES THROUGHOUT THE DAY...THE FEATURES BY MID- LATE AFTERNOON APPEAR TO BE SETTING UP FOR A NEARLY CLASSIC LOOKING COLD CORE SUPERCELL OUTBREAK. UNFORTUNATELY THERE ARE SMALL BUT IMPORTANT DIFFERENCES IN THE SUITE OF MODEL SOLUTIONS REGARDING WHERE THE UPPER AND SURFACE LOWS WILL TRACK...AND THESE DIFFERENCES COULD RESULT IN THE LOCATION OF THE SUPERCELLS VARYING BY SEVERAL COUNTIES DEPENDING ON THE SOLUTION. THE CONSENSUS SOLUTION OF THE SREF MEAN FOR THE PLACEMENT/TRACK OF THE UPPER AND SURFACE LOWS IS SIMILAR TO THE GOING FORECAST AS WELL AS CURRENT TRAJECTORIES OF THE UPPER LOW. USING THE SREF MEAN SOLUTION...THE FORECAST PATTERN IN THE 18-21Z TIME FRAME INCLUDES THE FOLLOWING INGREDIENTS TO SUPPORT SUPERCELLS OVER NORTHEAST NEBRASKA AND WEST CENTRAL IOWA: UPPER LOW OVER WESTERN NEBRASKA WITH 500 MB TEMPERATURES AROUND -19C... TRIPLE POINT AND DEEP SURFACE LOW NEAR O`NEILL...100+ KNOT UPPER LEVEL JET OVER EASTERN NEBRASKA...WELL PRONOUNCED DRY SLOT OVER EASTERN NEBRASKA WHICH WILL SUPPORT ML CAPE VALUES EXCEEDING 1200 J/KG AND A DIFFERENTIAL THERMAL BOUNDARY ON THE EASTERN EDGE OF THE DRY SLOT... AND 0-1KM SHEAR VALUES AT OR ABOVE 20 KNOTS. HOWEVER...NUMEROUS FACTORS INCREASE THE UNCERTAINTY IN THESE SCENARIOS INCLUDING THE ABOVE MENTIONED SPREAD IN MODEL SOLUTIONS. IF THE MODELS DISPLAYING A NORTHERN TREND ARE CORRECT...MUCH OF THE FORECAST AREA WOULD BE DRY AND SUNNY UNDER THE DRY SLOT WITH THE STRONG STORM DEVELOPMENT NORTH OF THE AREA. IF THE SOUTHERN SOLUTIONS ARE CORRECT...THE STORMS COULD DEVELOP AS FAR SOUTH AS INTERSTATE 80 AND TRACK NORTH THROUGHOUT THE AFTERNOON. THE FORECAST PROBABILITY OF STORMS WILL BE A FUNCTION OF THE DISTRIBUTION OF THESE MODEL SOLUTIONS. THE MOST LIKELY AREA FOR SEVERE STORMS WILL BE THE FAR NORTHEAST CORNER OF NEBRASKA AND WEST CENTRAL IOWA...WITH A CHANCE FOR SEVERE STORMS EXTENDING SOUTH TO INTERSTATE 80. LATEST OPERATIONAL HRRR SOLUTIONS SUPPORT THUNDERSTORM DEVELOPMENT BY EARLY AFTERNOON AND JUST EAST OF THE MISSOURI RIVER. THE STORMS AND SHOWERS SHOULD EXIT THE FORECAST AREA BY EVENING. LOW AMPLITUDE UPPER RIDGING AND SURFACE HIGH PRESSURE BUILDS INTO THE PLAINS MONDAY-TUESDAY WITH COOL BUT DRY WEATHER EXPECTED. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 350 AM CDT SUN MAY 10 2015 THE UPPER PATTERN RETURNS TO BROAD SCALE TROFFING OVER THE WESTERN US AND PACIFIC COASTAL AREAS WITH SHORTWAVES ONCE AGAIN RETURNING TO THE PLAINS. AFTER THE DRY BEGINNING OF THE WEEK...GOOD CHANCES FOR RAIN AND THUNDERSTORMS RETURN FOR THE PERIOD BEGINNING WEDNESDAY NIGHT AND PERSISTING INTO THE WEEKEND. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 613 AM CDT SUN MAY 10 2015 IFR/MVFR CEILINGS EARLY THIS MORNING...WHICH SHOULD SCATTER OUT BY 16 TO 18Z. SOUTHEAST WINDS AROUND 12 KNOTS...WITH GUSTS DEVELOPING INTO THE LOWER TO MID 20 KNOT RANGE BY 18Z. THUNDERSTORMS WILL BE POSSIBLE PRIMARILY AT THE KOMA TAF SITE 19-23Z. WINDS THEN SHIFT TO THE SOUTH...SOUTHWEST AND EVENTUALLY WEST NORTHWEST AS A COLD FRONT MOVES ACROSS THE AREA. COULD SEE MVFR CEILINGS AND SPOTTY SHOWERS DEVELOP AT KOFK BY 11/03Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...NIETFELD LONG TERM...NIETFELD AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
350 AM CDT SUN MAY 10 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 350 AM CDT SUN MAY 10 2015 ...LOCATION OF SEVERE STORMS TODAY IS THE MAIN CHALLENGE... EXCEPTIONALLY ACTIVE/DYNAMIC PATTERN CONTINUES OVER THE CENTRAL UNITED STATES TODAY AS LARGE UPPER LOW SPINS OVER THE HIGH PLAINS. WATER VAPOR IMAGERY SHOWED THE CLOSED AND WRAPPED UP CIRCULATION DRIFTING NORTHEAST AROUND 30 KNOTS...OUT OF NORTHEAST COLORADO AND HEADED FOR NORTHWEST NEBRASKA THIS MORNING. A COMPLEX AND HIGHLY BAROCLINIC SURFACE PATTERN WAS ANALYZED AT 06Z WITH A CLOSED 1004MB LOW NEAR THE KANSAS-COLORADO BORDER AND A TIGHT THERMAL AND PRESSURE GRADIENT NORTH OF THE LOW. WARM FRONT EXTENDED FROM THE LOW EASTWARD WITH LOW TO MID 60S DEW POINTS OVER KANSAS...AND AN INVERTED TROF EXTENDED NORTHEAST INTO THE SIOUX CITY AREA. AIRMASS NORTH OF THE LOW WAS COLD ENOUGH FOR WIDESPREAD SNOW IN THE WESTERN HIGH PLAINS THIS MORNING. AS THIS PATTERN EVOLVES THROUGHOUT THE DAY...THE FEATURES BY MID- LATE AFTERNOON APPEAR TO BE SETTING UP FOR A NEARLY CLASSIC LOOKING COLD CORE SUPERCELL OUTBREAK. UNFORTUNATELY THERE ARE SMALL BUT IMPORTANT DIFFERENCES IN THE SUITE OF MODEL SOLUTIONS REGARDING WHERE THE UPPER AND SURFACE LOWS WILL TRACK...AND THESE DIFFERENCES COULD RESULT IN THE LOCATION OF THE SUPERCELLS VARYING BY SEVERAL COUNTIES DEPENDING ON THE SOLUTION. THE CONSENSUS SOLUTION OF THE SREF MEAN FOR THE PLACEMENT/TRACK OF THE UPPER AND SURFACE LOWS IS SIMILAR TO THE GOING FORECAST AS WELL AS CURRENT TRAJECTORIES OF THE UPPER LOW. USING THE SREF MEAN SOLUTION...THE FORECAST PATTERN IN THE 18-21Z TIME FRAME INCLUDES THE FOLLOWING INGREDIENTS TO SUPPORT SUPERCELLS OVER NORTHEAST NEBRASKA AND WEST CENTRAL IOWA: UPPER LOW OVER WESTERN NEBRASKA WITH 500 MB TEMPERATURES AROUND -19C... TRIPLE POINT AND DEEP SURFACE LOW NEAR O`NEILL...100+ KNOT UPPER LEVEL JET OVER EASTERN NEBRASKA...WELL PRONOUNCED DRY SLOT OVER EASTERN NEBRASKA WHICH WILL SUPPORT ML CAPE VALUES EXCEEDING 1200 J/KG AND A DIFFERENTIAL THERMAL BOUNDARY ON THE EASTERN EDGE OF THE DRY SLOT... AND 0-1KM SHEAR VALUES AT OR ABOVE 20 KNOTS. HOWEVER...NUMEROUS FACTORS INCREASE THE UNCERTAINTY IN THESE SCENARIOS INCLUDING THE ABOVE MENTIONED SPREAD IN MODEL SOLUTIONS. IF THE MODELS DISPLAYING A NORTHERN TREND ARE CORRECT...MUCH OF THE FORECAST AREA WOULD BE DRY AND SUNNY UNDER THE DRY SLOT WITH THE STRONG STORM DEVELOPMENT NORTH OF THE AREA. IF THE SOUTHERN SOLUTIONS ARE CORRECT...THE STORMS COULD DEVELOP AS FAR SOUTH AS INTERSTATE 80 AND TRACK NORTH THROUGHOUT THE AFTERNOON. THE FORECAST PROBABILITY OF STORMS WILL BE A FUNCTION OF THE DISTRIBUTION OF THESE MODEL SOLUTIONS. THE MOST LIKELY AREA FOR SEVERE STORMS WILL BE THE FAR NORTHEAST CORNER OF NEBRASKA AND WEST CENTRAL IOWA...WITH A CHANCE FOR SEVERE STORMS EXTENDING SOUTH TO INTERSTATE 80. LATEST OPERATIONAL HRRR SOLUTIONS SUPPORT THUNDERSTORM DEVELOPMENT BY EARLY AFTERNOON AND JUST EAST OF THE MISSOURI RIVER. THE STORMS AND SHOWERS SHOULD EXIT THE FORECAST AREA BY EVENING. LOW AMPLITUDE UPPER RIDGING AND SURFACE HIGH PRESSURE BUILDS INTO THE PLAINS MONDAY-TUESDAY WITH COOL BUT DRY WEATHER EXPECTED. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 350 AM CDT SUN MAY 10 2015 THE UPPER PATTERN RETURNS TO BROAD SCALE TROFFING OVER THE WESTERN US AND PACIFIC COASTAL AREAS WITH SHORTWAVES ONCE AGAIN RETURNING TO THE PLAINS. AFTER THE DRY BEGINNING OF THE WEEK...GOOD CHANCES FOR RAIN AND THUNDERSTORMS RETURN FOR THE PERIOD BEGINNING WEDNESDAY NIGHT AND PERSISTING INTO THE WEEKEND. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1138 PM CDT SAT MAY 9 2015 MVFR CEILINGS WILL OVERTAKE ALL TAF SITES TONIGHT...AND SHOWERS SHOULD BE INCREASING IN COVERAGE AND SHOULD REACH TAF SITES LATER TONIGHT AS WELL. WITH LOW CONFIDENCE IN COVERAGE OF THUNDER...HAVE OPTED TO NOT MENTION AT KOFK AND BRING IN A TEMPO FOR AN HOUR AT KOMA/KLNK. OVERNIGHT ACTIVITY WILL CLEAR SITES IN THE MORNING...LEAVING A GAP BETWEEN THAT ACTIVITY AND POTENTIAL SHOWERS/STORMS THIS AFTERNOON. AFTERNOON SHOWERS/STORMS SHOULD BE PRETTY ISOLATED TO SCATTERED IN COVERAGE...ESPECIALLY AT KLNK WHERE CONFIDENCE IN SEEING SHOWERS/STORMS IS LOWEST. HAVE KEPT JUST A SHORT PERIOD OF VCSH AT ALL SITES UNTIL CONFIDENCE INCREASES...FOLLOWED BY WINDS VEERING TO WESTERLY AND INCREASING. MODELS HINT AT LOWER CEILINGS COMING IN BEHIND THE FRONT LATE IN THE TAF PERIOD...AND HAVE INTRODUCED POTENTIAL AT KOFK/KOMA. && .HYDROLOGY... ISSUED AT 350 AM CDT SUN MAY 10 2015 FLOODING CONTINUES IN SOUTHEAST NEBRASKA MAINLY ALONG THE BIG BLUE RIVER. FORTUNATELY THIS AREA IS NOT EXPECTED TO RECEIVE SIGNIFICANT RAINFALL OVER THE NEXT FEW DAYS...THEREFORE THE RIVER LEVELS SHOULD CONTINUE TO FALL AS PREDICTED. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...NIETFELD LONG TERM...NIETFELD AVIATION...MAYES HYDROLOGY...NIETFELD
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1132 PM CDT SAT MAY 9 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 345 PM CDT SAT MAY 9 2015 TONIGHT AND TOMORROW...FORECASTING CONCERNS CENTER ON THE SEVERE THREAT THIS EVENING...SNOW THREAT IN THE WEST AND NORTHWEST OVERNIGHT TONIGHT AND SUNDAY...AS WELL AS THE THREAT FOR HEAVY RAIN AND POSSIBLE FLASH FLOODING CONCERNS. A VIGOROUS UPPER LEVEL LOW...CURRENTLY OVER SOUTH CENTRAL COLORADO...WILL MIGRATE INTO NORTHEASTERN COLORADO THROUGH 12Z SUNDAY...BEFORE LIFTING INTO NORTHERN NEBRASKA BY 00Z MONDAY. IN ASSOCIATION WITH THIS FEATURE...STRONG TO POSSIBLY SEVERE THUNDERSTORMS WILL BE POSSIBLE THIS EVENING...FOLLOWED BY THE THREAT FOR HEAVY RAIN OVERNIGHT...THEN ACCUMULATING SNOWS IN THE EASTERN PANHANDLE AND NORTHWESTERN SANDHILLS OVERNIGHT. FIRST FOR THE SEVERE THREAT TONIGHT...A BULGING DRYLINE WILL PUSH FROM SWRN KS INTO NWRN KS BY 06Z SUNDAY. THUNDERSTORMS WILL INITIATE ALONG THIS FEATURE AND QUICKLY LIFT NORTH INTO SWRN AND SOUTH CENTRAL NEBRASKA. WITH THE LOW CLOUDS AND COOL CONDS TODAY...THE SEVERE THREAT CONTINUES TO DIMINISH ACROSS THE SWRN CWA. WITH THIS KIND OF SETUP...DRYLINE TO THE SOUTH...WARM FRONT TO THE SOUTH...THIS IS TYPICALLY A GOOD SETUP FOR LARGE HAIL AND THIS WILL BE THE MAIN HAZARD MENTIONED IN THE HWO. THEN THERE IS THE THREAT FOR SNOW IN THE PANHANDLE AND NORTHWESTERN SANDHILLS LATER THIS EVENING. ALREADY AS OF 2 PM THIS AFTERNOON...LIGHT SNOW WAS BEING REPORTED AT CHADRON...WHICH WAS EARLIER THAN ANTICIPATED WITH THE CURRENT FORECAST. ALREADY HAVE INCREASED SNOW ACCUMULATIONS IN THE PINE RIDGE AND NERN PANHANDLE...TO REFLECT AN EARLIER CHANGEOVER OF SNOW. THESE HIGHER ACCUMS APPG A FOOT WILL BE INCORPORATED IN THE UPDATE OF THE WINTER STORM WARNING FOR SHERIDAN COUNTY TO BE ISSUED WITH THE AFTERNOON PACKAGE. SOUTH AND EAST OF SHERIDAN COUNTY...SNOW IS EXPECTED AS WELL...HOWEVER A MUCH TIGHTER ENVELOPE FOR ACCUMS EXISTS GIVEN INCREASED MOISTURE AND WARMER TEMPS EXPECTED OVERNIGHT. NO DOUBT...THE RAIN/SNOW LINE WILL BE VERY TIGHT AND AS IT STANDS RIGHT NOW...THIS FEATURE RUNS RIGHT THROUGH SHERIDAN COUNTY. TURNING TO THE HEAVY RAIN THREAT TONIGHT...STRONG MOISTURE ADVECTION CONTINUES FROM THE SOUTHERN PLAINS INTO NEBRASKA PER 300K MOISTURE TRANSPORT VECTORS. PW/S WILL INCREASE BY MID EVENING TO 1.1 INCHES AT NORTH PLATTE...WHICH IS NEAR RECORD FOR THIS TIME OF YEAR. THIS MOISTURE WILL SHIFT QUICKLY NORTH OVERNIGHT AS THE UPPER LEVEL LOW PUSHES INTO NORTHEASTERN COLORADO...HOWEVER PW/S WILL STILL BE A HALF TO 2/3RDS OF AN INCH EVEN BEHIND THE DEEPEST AREA OF MOISTURE WHICH SHIFTS INTO EASTERN NEBRASKA AND SERN SOUTH DAKOTA BY SUNDAY MORNING. WIDESPREAD PRECIPITATION IS EXPECTED OVERNIGHT...WITH THE MOST PERSISTENT AREAS TRANSITIONING FROM THE PANHANDLE INTO SWRN AND CENTRAL NEBRASKA BY LATE EVENING. THIS IS IN RESPONSE TO EXPECTED CONVECTIVE DEVELOPMENT OVER NORTHWESTERN KS. THE LATEST HRRR AND THE NAM SOLN FROM THIS MORNING TO A LESSER DEGREE...FOLLOW THIS TREND OF HEAVIER RAIN SHIFTING INTO SWRN AND CENTRAL NEBRASKA LATER THIS EVENING...WITH DECREASED QPF IN THE WEST. THIS LULL WILL BE TEMPORARY HOWEVER. LOOK FOR PCPN TO INCREASE SUNDAY MORNING IN THE WEST AS DEFORMATION PCPN DEVELOPS ON THE BACK SIDE OF THE EXITING LOW. THE LATEST 3 HR FLASH FLOOD GUIDANCE IS LESS THAN 1.5 INCHES IN THE SERN PANHANDLE...KEITH AND PERKINS COUNTIES. THIS AREA HAS LARGELY ESCAPED THE HEAVY RAIN EARLIER THIS MORNING AND THIS AFTERNOON. WITH THE HRRR INDICATING HEAVIER RAIN EAST OF THESE AREAS...WILL FORGO ISSUANCE OF A FLASH FLOOD WATCH FOR THESE AREAS. FURTHER EAST...3 HR FFG IS AROUND 2 INCHES FOR CUSTER COUNTY SOUTH OF THE SANDHILLS. AGAIN HRRR QPF/S ARE AROUND 1 TO 2 INCHES IN CUSTER COUNTY TONIGHT...WHICH IS BELOW FFG SO WILL FORGO A FLASH FLOOD WATCH. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 345 PM CDT SAT MAY 9 2015 MODELS VARY SOME WITH AMOUNT OF COLD AIR MOVING THROUGH NORTHERN NEBRASKA SUNDAY NIGHT AND HAVE GONE WITH COLDER SOLUTION OF THE NAM. DEFORMATION ZONE WILL CONTINUE TO LIFT THROUGH THE NORTHERN NEBRASKA SANDHILLS WITH A MIX OF RAIN...RAIN SNOW MIX AND SNOW. HAVE A COUPLE OF INCHES OF ACCUMULATION WITH THE LIFT ASSOCIATED WITH THE DEFORMATION ZONE...OVER A VERY SMALL PORTION OF NORTHERN CHERRY COUNTY. WINDS WILL STAY UP THROUGH MONDAY WITH PRECIP ENDING THROUGH THE MORNING. LOW TEMPERATURES IN THE 20S NORTHWEST TO THE MID 30S NORTH CENTRAL...ONEILL. HIGHS IN THE 40S WEST AND THE 50S SOUTHWEST AND EAST. CLEARING SKIES THROUGH THE DAY WITH MOSTLY CLEAR SKIES OVER NIGHT. WINDS FALLING OFF AND BECOMING SOUTH OVER NIGHT WILL ALLOW TEMPERATURES TO FALL TO AROUND FREEZING. HAVE HELD OFF ON HIGHLIGHTS FOR NOW WITH CURRENT HIGHLIGHTS OUT. TEMPERATURES REBOUND MONDAY AND TUESDAY AS RIDGE EXPANDS WEST. WEAK WAVE TO MOVE THROUGH TUESDAY NIGHT INTO WEDNESDAY MORNING SLIGHT CHANCES RETAINED FOR SOUTHWEST INTO NORTH CENTRAL NEBRASKA. CHANCES FOR PRECIPITATION RETURN TO THE FORECAST THURSDAY AND CONTINUE THROUGH THE END OF THE PERIOD AS ENERGY EJECTS FROM A CLOSED LOW OFF THE PACIFIC COAST AND TEMPERATURES RISING INTO THE 70S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1118 PM CDT SAT MAY 9 2015 A POWERFUL UPPER LEVEL STORM SYSTEM WILL TRACK ACROSS EASTERN COLORADO INTO WESTERN NEBRASKA OVERNIGHT TONIGHT INTO SUNDAY. WIDESPREAD RAIN AND MVFR TO IFR CIGS ARE EXPECTED AT THE KLBF AND KVTN TERMINALS THROUGH 00Z MONDAY. RAIN MAY MIX WITH SNOW AT THE KVTN TERMINAL WITH VISBYS AS LOW AS 2SM OVERNIGHT. FLT CONDS WILL IMPROVE SUNDAY EVENING WITH CIGS INCREASING TO 5000 FT AGL AT THE KLBF TERMINAL...AND 1500 FT AGL AT THE KVTN TERMINAL. && .HYDROLOGY... ISSUED AT 345 PM CDT SAT MAY 9 2015 THE ONGOING LARGE SCALE AND LONG DURATION HEAVY PRECIP EVENT OVER THE HIGH PLAINS WILL LEAD TO FLOODING CONCERNS NEXT WEEK ON THE SOUTH PLATTE RIVER IN SOUTHWEST NEBRASKA INCLUDING DEUEL...KEITH...AND LINCOLN COUNTIES. AS OF SATURDAY MORNING THE SOUTH PLATTE RIVER IS ALREADY EXPERIENCING ABOVE NORMAL FLOWS DUE TO SNOW MELT RUNOFF IN THE FRONT RANGE MOUNTAINS OF COLORADO. LATEST RIVER FORECAST PROJECTIONS SHOW AN INCREASING THREAT FOR SIGNIFICANT FLOODING BY THE SECOND HALF OF NEXT WEEK. HOWEVER...HIGH UNCERTAINTY STILL REMAINS IN THE AMOUNT OF OBSERVED/FORECAST RAINFALL IN NORTHEAST COLORADO AND WESTERN NEBRASKA...AS WELL AS HOW IT WILL IMPACT UPSTREAM FLOWS ON THE SOUTH PLATTE RIVER. RIVER FORECASTS WILL BE CLOSELY MONITORED AND UPDATED AS MORE INFORMATION BECOMES AVAILABLE. && .LBF WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 PM MDT SUNDAY FOR NEZ022-023-056- 094. WINTER STORM WARNING UNTIL 6 PM MDT SUNDAY FOR NEZ004. && $$ SHORT TERM...CLB LONG TERM...POWER AVIATION...CLB HYDROLOGY...MARTIN
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
835 AM PDT SUN MAY 10 2015 .SYNOPSIS...CLOUDS AND PERHAPS A SHOWER WILL PASS ACROSS NORTHERN MOHAVE COUNTY TODAY AS MOISTURE LINGERS ON THE BACK SIDE OF A DEPARTING STORM SYSTEM. OTHERWISE EXPECT DRY CONDITIONS WITH A CONTINUED WARMING TREND THROUGH MONDAY. A SYSTEM WILL PASS BY NORTHWEST OF THE AREA MONDAY NIGHT INTO TUESDAY BRINGING SOME CLOUDS AND BREEZY CONDITIONS. ANOTHER STORM SYSTEM COULD IMPACT THE AREA LATE NEXT WEEK WITH COOLER WEATHER AND SHOWERS POSSIBLE ON FRIDAY AND SATURDAY. && .UPDATE... ONLY MADE MINOR ADJUSTMENTS TO TEMPS AND SKY THIS MORNING TO ACCOUNT FOR CURRENT CONDITIONS/TRENDS. ONLY A SMALL CHANCE OF A SHOWER ACROSS NORTHERN MOHAVE COUNTY TODAY. LAST FEW RUNS OF THE HRRR DON`T SHOW MUCH OF ANYTHING. EXPECT A WARMER DAY THAN YESTERDAY AS RIDGING ALOFT BUILDS OVER THE REGION. NO OTHER UPDATES ANTICIPATED THIS MORNING. && .PREVIOUS DISCUSSION... 305 AM PDT SUN MAY 10 2015 .SHORT TERM...TODAY THROUGH TUESDAY NIGHT. A NICE MOTHER`S DAY IS EXPECTED ACROSS THE AREA TODAY FOR THE MOST PART AS MID/UPPER LEVEL RIDGE STARTS TO BUILD IN. THIS WILL PROMOTE FURTHER WARMING AND LOTS OF SUNSHINE. HIGH TEMPS WILL RISE ABOUT 8- 10 DEGREES FROM SATURDAY BUT IN MOST SPOTS STILL BE A FEW DEGREES BELOW NORMAL. THE ONLY EXCEPTION TO TODAY`S STELLAR WEATHER WILL BE IN THE ARIZONA STRIP AREA WHERE LINGERING MOISTURE AND ENERGY ON THE BACK SIDE OF THE HIGH PLAINS COLD LOW`S BROAD CIRCULATION TRIGGERS SOME CLOUDS AND POSSIBLY A QUICK SHOWER OR SPRINKLE THIS AFTERNOON. OUR ATTENTION WILL NOW TURN TO THE NEXT AREA OF LOW PRESSURE PRESENTLY OFF THE COAST OF WASHINGTON. THIS FEATURE IS EXPECTED TO SWING ACROSS THE PAC NW MONDAY THROUGH TUESDAY NIGHT. FOR OUR AREA IT WILL STAY WELL ENOUGH TO THE NORTHWEST THAT ALL WE WILL SEE IS AN INCREASE IN CIRRUS (ALTHOUGH IT DOES NOT LOOK LIKE AN OVERABUNDANCE OF IT) AND AN INCREASE IN SOUTHWEST TO WEST WINDS BOTH MONDAY AND TUESDAY IN THE AFTERNOON AND EVENING HOURS WITH GUSTS OF 15-25 MPH. THE INCREASED SOUTHWEST FLOW WILL HELP TO MIX THE ATMOSPHERE BETTER AND PUSH TEMPS BACK UP A FEW MORE DEGREES FOR MONDAY WITH NEAR STATUS-QUO TEMPS ON TUESDAY. THIS WILL PUT HIGHS A FEW DEGREES ABOVE NORMAL FOR A CHANGE WHICH MEANS BACK TO THE 90-102 RANGE FOR THE LOWER ELEVATIONS OF THE MOJAVE DESERT. I SIDED WITH THE WARMER END OF GUIDANCE BOTH DAYS FOR HIGH TEMPS. .LONG TERM...WEDNESDAY THROUGH SATURDAY. DRY SOUTHWEST FLOW TO START THE PERIOD WILL GIVE WAY TO INCREASING SOUTHERLY FLOW BY THURSDAY AS LOW PRESSURE NEARS THE WEST COAST. BY FRIDAY THERE ARE CRITICAL MODEL DISAGREEMENTS ON THE POSITION AND DEPTH OF THE LOW AS WELL AS A MOISTURE PLUME WRAPPING AROUND ITS SOUTHEAST SEMICIRCLE. THIS WILL MAKE A BIG DIFFERENCE IN THE PROBABILITY AND PLACEMENT OF SHOWERS AND THUNDERSTORMS OVER THE CWA FRIDAY AND SATURDAY. FOR NOW HAVE KEPT THE BRUSH BROAD AND THE MAX POPS RELATIVELY LOW DUE TO THESE UNCERTAINTIES. NEAR NORMAL TEMPERATURES WEDNESDAY WILL START TO COME DOWN ON THURSDAY AND THEN CRASH FRIDAY AND SATURDAY AS THE LOW MOVES IN. EXPECT BREEZY SOUTH WINDS WEDNESDAY AND THURSDAY AND POTENTIALLY STRONGER WEST WINDS FRIDAY AND SATURDAY /DEPENDING ON HOW FAR SOUTH THE LOW CENTER DIGS/. && .AVIATION...FOR MCCARRAN...WINDS SHOULD FAVOR TYPICAL DIURNAL DIRECTIONAL TRENDS AT 8 KTS OR LESS THROUGH TONIGHT UNDER A RELATIVELY CLEAR SKY. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...AN ISOLATED SHRA IS POSSIBLE THIS AFTERNOON IN NORTHERN MOHAVE COUNTY WITH SCT-BKN CLOUDS AOA 6K-10K FEET. OTHERWISE A RELATIVELY CLEAR SKY IS EXPECTED ACROSS THE AREA. OVERALL WINDS SHOULD MAINLY FOLLOW DIURNAL DIRECTIONAL TRENDS AT 12 KTS OR LESS THROUGH TONIGHT. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT REQUESTED THROUGH WEDNESDAY NIGHT. SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES LATER THIS WEEK. && $$ UPDATE...PADDOCK SHORT TERM/AVIATION...STACHELSKI LONG TERM...MORGAN FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
FORECAST DISCUSSION FOLLOWS.

WILL CONTINUE CHC/LKLY POP THROUGH NIGHTFALL BUT A RAPID DECREASE IN COVERAGE IS EXPECTED WITH LOSS OF HEATING. A RESIDUAL LAYER OF ELEVATED INSTABILITY IS PROGGED IN SOUNDINGS TO PERSIST WELL AFTER DARK...SO ALTHOUGH THE HRRR SHOWS NO PRECIP AFTER MIDNIGHT...HAVE OPTED TO KEEP SCHC/ISO SHOWERS THROUGH THE OVERNIGHT. THE OTHER INTERESTING FEATURE TONIGHT HAS BEEN SEA FOG WHICH DEVELOPED SOMEWHAT SURPRISINGLY THIS AFTN AND ADVECTED INTO THE GRAND STRAND AND BRUNSWICK COUNTY. WE ARE BEYOND THE CLIMATOLOGICALLY FAVORED SEASON FOR SEA FOG...AND THE LOCAL DECISION TREE SUGGESTS VSBYS SHOULD BE UNRESTRICTED. YET...SEA FOG DID DEVELOP AND BOTH THE HORRY AND BRUNSWICK COUNTY COASTS ARE "SOCKED IN` AS OF THIS WRITING. IT IS BELIEVED THAT UPWELLING FROM LONG DURATION OFFSHORE WINDS ON THE BACKSIDE OF RECENTLY-DEPARTED TROPICAL STORM ANA COOLED THE SHELF WATERS ENOUGH TO PRODUCE THE REQUIRED AIR-TO-OCEAN TEMP GRADIENT, THIS COMBINED WITH THE SW FLOW TO CREATE LONG ENOUGH PARCEL RESIDENCE TIMES FOR SATURATION AND SEA FOG. CERTAINLY AN INTERESTING SITUATION AND ONE FROM WHICH WE CAN LEARN! STILL EXPECT VISIBILITY TO IMPROVE IN THE NEXT HOUR OR TWO AS CONDITIONS ARE FAR FROM IDEAL FOR PERSISTENT SEA FOG. MINS TONIGHT WILL BE HELD ABOVE CLIMO THANKS TO CONTINUED SW RETURN FLOW...AND LOWS WILL DROP TO A DEGREE OR TWO EITHER SIDE OF 70...WARMEST AT THE COAST. GUIDANCE IS SUGGESTING STRATUS DEVELOPMENT TONIGHT...AND IN THIS MOIST COLUMN IT IS DEFINITELY PLAUSIBLE. HAVE SHOWN AN INCREASE IN CLOUD COVER AFTER MIDNIGHT...WHICH WILL ALSO HELP TO KEEP MINS ELEVATED. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 330 PM MONDAY...WEAK COLD FRONT WILL PUSH ACROSS THE AREA LATE TUE NIGHT. AHEAD OF THE FRONT THE ENVIRONMENT APPEARS RIP FOR DEVELOPMENT OF AFTERNOON CONVECTION. DEEP MOISTURE IS PRESENT WITH FORECAST SOUNDINGS CARRYING PRECIPITABLE WATER VALUES OF 1.5 TO 1.6 INCH...WHICH IS WITHIN THE HIGHEST 10% FOR EARLY MAY. SOUNDINGS CONTINUE TO ADVERTISE ML CAPE IN THE 2K TO 2.5K J/KG RANGE WEST OF THE SEA BREEZE...WHICH WEST-SOUTHWEST FLOW SHOULD KEEP CLOSER TO THE COAST. THE AFOREMENTIONED SEA BREEZE AND PREFRONTAL TROUGH ARE LIKELY TO INITIATE AFTERNOON CONVECTION WITH OUTFLOW DEVELOPING ADDITIONAL STORMS. MUCH OF THE AREA REMAINS IN THE SPC DAY 2 OUTLOOK MARGINAL AREA AND FORECAST SOUNDINGS DO SUGGEST SOME POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS. HOWEVER...ORGANIZED WIDESPREAD STRONG/SEVERE ACTIVITY IS NOT LIKELY. SHEAR IS NOT PARTICULARLY STRONG BUT LIFTED INDEX VALUES ARE -5C TO -6C AND FAIRLY STRONG UPDRAFTS SHOULD BE POSSIBLE. FREEZING LEVEL AROUND 13K FT LIKELY RULES OUT SIZABLE HAIL SO THE MAIN THREAT WOULD BE ISOLATED DAMAGING WIND GUSTS. COLD FRONT PUSHES ACROSS THE AREA TUE NIGHT WITH MUCH DRIER AIR MASS BUILDING IN BEHIND IT. PRECIPITABLE WATER VALUES DROP OVER AN INCH TUE INTO WED. DEEP NORTHWEST FLOW/MID LEVEL SUBSIDENCE WILL KEEP SKIES CLEAR WED AFTERNOON. THE ONLY CAVEAT WILL BE ACROSS THE COASTAL SC COUNTIES. THERE IS A WEAK SHORTWAVE CROSSING SC...WHICH DOES HELP PUSH THE FRONT THROUGH...BUT THIS SHORTWAVE COULD TAKE A BIT LONGER TO PUSH OFF THE SC COAST. IF THAT HAPPENS CLOUDS COULD LINGER ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA. AT THIS POINT DO NOT THINK PRECIP WILL LINGER INTO WED BUT WILL CARRY A NON-ZERO POP FOR THE MORNING HOURS. TEMPS WELL ABOVE CLIMO TUE WILL COOL OFF QUITE A BIT WED BUT HIGHS STILL END UP RIGHT AROUND CLIMO...SHOWING JUST HOW WARM TUE IS GOING TO BE. LOWS ABOVE CLIMO TUE NIGHT WILL BE NEAR TO SLIGHTLY BELOW CLIMO WED NIGHT. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 AM SUNDAY... MID LEVEL RIDGE OVERHEAD THURSDAY WHILE SURFACE HIGH REMAINS TO OUR NORTH. LIKE WEDNESDAY WE EXPECT ANOTHER SUNNY AND SEASONABLE DAY WITH FAIRLY LOW HUMIDITY. THIS WILL CHANGE THURSDAY NIGHT INTO FRIDAY AS BOTH MOVE EASTWARD. THE WARMING WILL BE RATHER GENTLE BUT THE HUMIDITY CREEPING UP MORE NOTICEABLE. THE WEEKEND SHOULD THUS BRING FAIRLY SEASONABLE WARMTH AND HUMIDITY BUT ALSO AT LEAST A SCATTERING OF MAINLY DIURNAL CONVECTION. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 00Z...A MIXTURE OF VFR/MVFR/IFR THIS EVENING DUE TO SHRA/TSRA ALONG WITH FOG/LOW CIGS WILL GRADUALLY DETERIORATE TO MAINLY MVFR/IFR. ON TUESDAY...EXPECT VFR WITH AFTERNOON/EVENING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN ASSOCIATION WITH AN APPROACHING COLD FRONT. LATEST RADAR DEPICTS SHOWERS AND THUNDERSTORMS MOVING ACROSS PORTIONS OF THE FORECAST AREA THIS EVENING. EXPECT THIS ACTIVITY TO GRADUALLY TAPER OFF TONIGHT...WITH PERIODS OF SHRA/TSRA MAINLY AT KLBT/KILM. GIVEN STABLE LAYER ACROSS KCRE/KMYR...DO NOT ANTICIPATE MUCH IN THE WAY OF RAINFALL...BUT WOULD NOT ENTIRELY RULE OUT -SHRA. SOUTHWEST WINDS AOB 10 KTS WILL CONTINUE TONIGHT. INTO THE OVERNIGHT HOURS...ANTICIPATE LOW CIGS WITH AREAS OF FOG ALONG THE COAST...WITH PATCHY FOG INLAND...CREATE MVFR/IFR. ON TUESDAY...CONDITIONS WILL IMPROVE TO VFR WITH SHRA/TSRA ANTICIPATED INTO THE AFTERNOON/EVENING HORUS IN ASSOCIATION WITH AN APPROACHING COLD FRONT. WEST-SOUTHWEST WINDS AOB 15 KTS WITH GUSTS AROUND 20 KTS POSSIBLE THROUGHOUT THE DAY. EXTENDED OUTLOOK...SCATTERED SHOWERS POSSIBLE ON FRIDAY. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 758 PM MONDAY...SW FLOW WILL CONTINUE THROUGH TONIGHT WITH FAIRLY STEADY 10- 15 KT SW WINDS...ALTHOUGH A FEW GUSTS TO 20 KTS WILL BE POSSIBLE OVERNIGHT...ESPECIALLY NEAR SHOWERS OR ISOLATED TSTMS. SEAS 2-4 FT...WITH A 6-7 SECOND PERIOD WAVE PREDOMINANT. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 PM MONDAY...SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL INCREASE AS GRADIENT AHEAD OF THE FRONT TIGHTENS. SPEEDS PEAK AROUND 20 KT IN TUE AFTERNOON AND EVENING WITH SEAS RUNNING 3 TO 4 FT. WINDS VEER TO WESTERLY LATE TUE NIGHT AS THE FRONT CROSSES THE WATERS. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT LIMITS THE STRENGTH OF THE GRADIENT AND DEVELOPING OFFSHORE FLOW WILL BE UNDER 15 KT EARLY WED. WINDS WILL QUICKLY VEER TO NORTHEAST FOR WED BUT GRADIENT REMAINS ILL DEFINED AND SPEEDS STAY 15 KT WITH SEAS RUNNING 2 TO 3 FT THROUGH THE END OF THE PERIOD. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 AM SUNDAY... THE HIGH LOCATED TO OUR NORTH DURING THE SHORT TERM PROGRESSES EAST DURING THE LONG TERM. WINDS VEER FROM N TO E EARLY IN THE PERIOD AND SHALL MORE OR LESS REMAIN SAVE FOR PERHAPS A SLIGHT ADDITIONAL VEER TO SE BY FRIDAY. THERE WILL BE NO APPRECIABLE SWELL ENERGY TO SPEAK OF SO THE FAIRLY MINOR WIND WAVES WILL BE THE DOMINANT SEA STATE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...JDW/MJC SHORT TERM...III LONG TERM...MBB AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
750 PM EDT MON MAY 11 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TUESDAY AFTERNOON AND EVENING. COOL HIGH PRESSURE WILL BUILD INTO THE AREA THROUGH MID-WEEK. && .NEAR TERM /TONIGHT/... AS OF 315 PM MONDAY... WEAKENING REMAINS OF TC ANA WILL CONTINUE TO MOVE NORTHEASTWARD INTO SOUTHEAST VA THIS AFTERNOON AND EVENING WITH AN EXPECTED INCREASE IN ACCELERATION AS SW FLOW ALOFT STRENGTHENS IN ADVANCE OF A MID/UPPER LEVEL TROUGH MOVING NORTHEASTWARD INTO THE MID/UPPER VALLEY. IN THE WAKE OF TC ANA EXITING THE AREA...MODERATE DESTABILIZATION OF 2000-2500 J/KG PER SPC MESOANALYSIS HAS DEVELOPED IN RESPONSE TO STEEP LOW-LEVEL LAPSE RATES ATOP A SEASONABLY MOIST BOUNDARY LAYER FEATURING BL DEWPOINTS IN THE UPPER 60S TO LOWER 70S. FORCING FOR ASCENT THIS AFTERNOON AND EVENING LOOKS TO BE DRIVEN BY TWO SEPARATE WEAK FEATURES...1)ALONG SHALLOW CONVERGENCE ATTENDANT TO A DEVELOPING SURFACE TROUGH IN THE LEE OF THE MOUNTAINS AND 2) A WEAK UPPER LEVEL DISTURBANCE OVER SW NC/SC. INITIALLY...EXPECT CONVECTION TO BE CONFINED TO THE WESTERN PIEDMONT AND SANDHILLS/SOUTHERN COASTAL PLAIN WHERE THE SUPPRESSIVE INFLUENCE OF SUBSIDENCE ON THE WESTERN PERIPHERY OF TC ANA`S REMNANTS WILL NO LESS. GIVEN WEAK FORCING...EXPECT CONVECTION TO BE LARGELY DIURNAL IN NATURE...AND THUS EXPECT MUCH OF THE ACTIVITY TO DROP OFF QUICKLY AFTER SUNSET. HOWEVER...THE LATEST HRRR SUGGEST INITIAL STORMS OUT WEST COULD PERSIST THROUGH MIDNIGHT AS THEY WORK SLOWLY EASTWARD INTO THE COASTAL PLAIN. HAVE EXTENDED SMALL CHANCE POPS THROUGH 05- 06Z. WRT TO SEVERE WX...WEAK DEEP LAYER SHEAR OF 10-15 KTS WILL PRECLUDE A MORE ORGANIZED THREAT. HOWEVER...GIVEN MODERATE INSTABILITY AND DCAPE ~1000J/KG CANNOT RULE OUT AN ISOLATED SEVERE STORM CAPABLE OF PRODUCING LOCALIZED WIND DAMAGE....ESPECIALLY IN THE WEST IN PROXIMITY TO DRIER AIR. UNDER PARTLY TO MOSTLY CLOUDY MID AND HIGH CLOUDS...EXPECT MILD OVERNIGHT LOWS IN THE UPPER 60S TO NEAR 70. && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... AS OF 315 PM MONDAY... MID AND UPPER LEVEL FLOW REALLY FLATTENS OUT...BECOMING WESTERLY ON TUESDAY AS THE WELL REMOVED UPPER TROUGH TRAVERSE THE UPPER GREAT LAKES/NEW ENGLAND. ATTENDANT SURFACE LOW TRACKING THROUGH SE CANADA WILL DRAG A COLD FRONT THROUGH THE AREA BETWEEN 18Z TUESDAY IN THE WEST TO 00 TO 03Z IN THE EAST. GUIDANCE SUGGESTS BL DEWPOINTS WILL BE APT TO MIX OUT A BIT...ESPECIALLY OVER THE WESTERN PIEDMONT TUESDAY AFTERNOON. THE WESTERLY COMPONENT ALOFT AND LACK OF SUPPORT ALOFT WILL TEND TO SUPPRESS CONVECTION ACROSS A LARGE CHUNK OF THE FORECAST WITH CONVECTION MOST APT TO FIRE ACROSS EASTERN PIEDMONT AND COASTAL PLAIN(I-95 CORRIDOR)...WHERE LINGERING LOW-LEVEL MOISTURE AND STRONG INSOLATION COULD SUPPORT MODERATE TO STRONG DESTABILIZATION OF 2000-3000 J/KG OF SBCAPE. WRT TO SEVERE POTENTIAL...DEEP LAYER SHEAR MAY BE MARGINALLY BETTER THAN TODAY... BUT NOT BY MUCH...PARTICULARLY IN THE EAST. THUS A FEW STRONG TO SEVERE THUNDERSTORMS CAPABLE OF PRODUCING LOCALIZED WIND DAMAGE MAY DEVELOP ACROSS THE EASTERN PIEDMONT/COASTAL PLAIN AREAS. LOW-LEVEL THICKNESSES WILL BE MORE REPRESENTATIVE OF MID TO LATE JUNE AS OPPOSED TO EARLY MAY. EXPECT HIGHS IN THE UPPER 80S TO LOWER 90S...WHICH WOULD BE THE FIRST TIME WE REACHED 90 DEGREES AT KRDU AND KFAY. SKIES SHOULD CLEAR OUT TUESDAY EVENING/NIGHT WITH CAA DRIVING OVERNIGHT LOWS. LOWS RANGING FROM MID 50S NW TO LOWER 60S SE. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 300 PM MONDAY... SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE GREAT LAKES WEDNESDAY THROUGH THURSDAY...BEFORE SHIFTING OFFSHORE THURSDAY NIGHT INTO FRIDAY. AT THE SAME TIME...MID LEVEL RIDGING WILL BUILD OVER THE AREA FROM THE EAST. MUCH COOLER AND DRIER AIR WILL FILTER INTO THE REGION...RESULTING IN A PERIOD OF DRY WEATHER AND NEAR TO SLIGHTLY BELOW NORMAL TEMPS. AS THE SURFACE HIGH CONTINUES TO SHIFT OFFSHORE ON FRIDAY...MOISTURE WILL BEGIN TO RECOVER ON THE BACK SIDE OF THE HIGH. HOWEVER...THE MID LEVEL RIDGING WILL STICK AROUND FOR A WHILE LONGER WHICH MAY PREVENT WIDESPREAD CONVECTION. AS OF NOW...IT APPEARS THE BEST CHANCE OF A SHOWER OR STORM WILL BE ACROSS THE WESTERN PIEDMONT ON FRIDAY AND SATURDAY...WITH CHANCES SPREADING EAST (AND INCREASING) SUNDAY INTO MONDAY AS MOISTURE AND INSTABILITY INCREASES EVEN MORE. TEMPS WILL GRADUALLY WARM EACH DAY...WITH HIGHS GENERALLY IN THE MID 80S AND OVERNIGHT LOWS IN THE MID 60S BY EARLY NEXT WEEK. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 750 PM MONDAY... CURRENTLY...SCATTERED SHOWERS AND STORMS ACROSS THE SANDHILLS AND SOUTHERN COASTAL PLAIN POSE ONLY A THREAT TO KFAY IN THE NEXT COUPLE HOURS. VFR CONDITIONS PREVAIL...AND ANY SUB-VFR CONDITIONS WILL BE BRIEF AND CONFINED TO THE HEAVIEST SHOWERS/STORMS. MEANWHILE..A PRONOUNCED SEABREEZE/OUTFLOW SURGE NORTH INTO THE PIEDMONT HAS BEEN ACCOMPANIED BY SOME WIND GUSTS AROUND 30KT AS WINDS SHIFT TO SOUTHERLY. WHILE LIKELY NOT AS STRONG...A WIND SHIFT CAN BE EXPECTED AT KRDU AROUND 00Z. TO THE WEST...ANOTHER OUTFLOW BOUNDARY ASSOCIATED WITH EARLIER CONVECTION IN THE MOUNTAINS IS MOVING INTO THE WESTERN PEIDMONT...WHICH MAY RESULT IN SOME RENEWED CONVECTION AROUND THE TRIAD TERMINALS (KGSO/KINT) THROUGH 02Z. ONCE THE CONVECTION DIES DOWN...WHICH IS ANTICIPATED TO OCCUR BY MIDNIGHT...THERE IS A CHANCE OF SOME STRATUS...MAINLY ACROSS EASTERN/SOUTHERN AREAS. CONFIDENCE ISNT VERY HIGH...BUT NEAR TERM GUIDANCE SUGGEST AT LEAST SOME SCATTERED LOW CLOUDS FROM KFAY TO KRWI BY 10Z. WINDS WILL REMAIN OUT FO THE SOUTHWEST AT 4-8KT. A COLD FRONT WILL APPROACH FROM THE WEST DURING THE DAY ON TUESDAY. SOUTHWESTERLY WINDS WILL ICNREASE TO AROUND 12KT AHEAD OF THE FRONT...AND THE NEST CHANCE FOR SHOWERS/STORMS IS EXPECTED TO BE EAST OF KRDU TOWARD KRWI AND KFAY. LOOKING AHEAD: EXPECT DRY VFR CONDITIONS TUESDAY NIGHT THROUGH FRIDAY ASSOCIATED WITH COOL HIGH PRESSURE BUILDING OVER THE AREA. THE HIGH WILL PUSH OFFSHORE ON FRIDAY. SOUTHERLY RETURN FLOW ON THE WESTERN PERIPHERY OF THE HIGH WILL BRING AN INCREASE LIKELIHOOD OF SUB-VFR CONDITIONS IN MORNING FOG AND/OR STRATUS ALONG WITH A CHANCE OF MAINLY AFTERNOON SHOWERS AND STORMS LATE FRIDAY NIGHT AND INTO THE WEEKEND. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT/CBL NEAR TERM...CBL SHORT TERM...CBL LONG TERM...KRD AVIATION...CBL/22
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
345 PM EDT SUN MAY 10 2015 .SYNOPSIS... ANA WILL GRADUALLY WEAKEN AND LIFT NORTHEAST OVER THE COASTAL PLAIN TONIGHT INTO MONDAY. A COLD FRONT APPROACHES FROM THE NORTHWEST TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK. && .NEAR TERM /TONIGHT/... AS OF 345 PM SUN...REMNANTS OF ANA CURRENTLY OVER SE NC...AND SLOWLY LIFTING NORTH NORTHEAST. HEAVY RAINS HAVE ABATED FOR THE TIME BEING...WITH BULK OF RAIN SHOWERS MORE STRATIFORM AND CONCENTRATED NEAR THE STORM CENTER. THINKING THAT CONVECTIVE BANDS OF RAIN SHOWERS WITH EMBEDDED THUNDER...HEAVY AT TIMES...WILL REDEVOLOP OVERNIGHT PER MESOSCALE CONVECTIVE INITIATING MODELS. WILL LEAVE FLOOD WATCH INTACT. ALSO...ISOLATED TOR THREAT MAY DEVELOP AS FAVORABLE LOW LEVEL SHEAR VALS INC OVERNIGHT AS CENTER OF ANA MAKES HER WAY THROUGH THE COASTAL PLAIN/INTERSTATE 95 CORRIDOR. HIGH RES MODELS INDICATE AN UPTICK IN UPDRAFT HELICITY AFTER AROUND 04Z...AND WITH SFC WINDS STILL BACKED SSE...THIS WOULD YIELD INC LOW LEVEL HELICITY AS H85MB WINDS VEER SWRLY. WILL CONTINUE TO HIGHLIGHT THESE THREATS IN HWO. MUGGY OVERNIGHT LOWS WITH MOST AREAS DROPPING NOW LOWER THAN 70 OVERNIGHT. && .SHORT TERM /MONDAY/... AS OF 345 PM SUN...SHOULD SEE THREAT FOR HEAVY RAIN SHOWERS END THROUGH THE EARLY MORNING WITH PRECIP COVERAGE AND INTENSITY TAPERING OFF SOMEWHAT AS REMNANTS OF THE SYSTEM WITH BEST LIFT MOVE NORTHEAST INTO VA. STILL HUNG ONTO LIKELY POPS ACROSS THE NORTH WITH HIGH CHANCE/SCT SOUTHERN AREAS. TEMPS WILL BE HELD DOWN AGAIN WITH THE MOSTLY CLOUDY SKIES...THOUGH SOME SUN COULD BREAK OUT ESP IN THE AFTERNOON WITH READINGS IN THE 80S ACROSS THE SW. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... REMNANT ANA LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT. HOWEVER A MOIST SW FLOW WILL REMAIN IN PLACE TUESDAY AHEAD OF SHEARING UPPER TROF AND ASSOCD SFC COLD FRONT WITH CHANCES FOR SCATTERED SHOWERS CONTINUING. MOIST BNDRY LAYER SUGGESTS MOCLOUDY SKIES THRU TUESDAY MORNING THEN SUNNY BREAKS DEVELOP WITH MIXING ALLOWING TEMPS TO SOAR TO NEAR 90 DEGREES INLAND TUESDAY AFTERNOON. DESTABILIZATION AND SPEED SHEAR MAY BE SUPPORTIVE OF STRONG TO SEVERE TSTORMS TUESDAY AFTERNOON INTO EVENING. COLD FRONT SLIDES THRU THE AREA LATE TUESDAY NIGHT THEN UPPER RIDGE BUILDS EAST WITH SFC HIGH RIDGING IN FROM THE NORTH. THE DRIER, MORE STABLE AIRMASS WILL KEEP RAIN CHANCES AT BAY THRU AT LEAST THURSDAY AND POSSIBLY THRU THE END OF THE WEEK UNLESS SHORT WAVE ENERGY/DEEP MOISTURE CAN PENETRATE UPPER RIDGE MOVING OFFSHORE. MAY BE INCREASINGLY UNSETTLED NEXT WEEKEND AS ZONAL FLOW AND STALLED SFC BNDRY LINGER OVER THE AREA. AFTER A HOT/HUMID TUESDAY, TEMPERATURES WILL SETTLE TO SLIGHTLY BLO NORMAL LEVELS THRU THE END OF THE WEEK. TEMPS MAY REBOUND TO MORE SEASONAL LEVELS NEXT WEEKEND DEPENDING ON PLACEMENT OF STALLED OUT SFC FRONT. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... AS OF 130 PM SUN...VFR/MVFR CONDITIONS OVER EASTERN NORTH CAROLINA TAFS AS CENTER OF ANA MOVES NORTH INTO NC TO OUR SW. RAIN BANDS ROTATING ACROSS REGION FROM OFFSHORE EXTENDS FROM ONSLOW/CARTERET COUNTY TO THE NW AS IT CONTINUES TO PUSH TO THE NORTH AND AFFECTING KEWN AND KPGV REDUCING CIGS TO MVFR. EXPECT TO SEE MORE STEADY RAIN STARTING IN LATER THIS AFTERNOON AS CENTER OF ANA MOVES SLOWLY NORTH. HAVE MODERATE CONFIDENCE IN MVFR CONDITIONS ACROSS ALL TERMINALS WITH ISOLATED IFR CONDITIONS. WINDS HAVE NOT BEEN AN ISSUE WITH GUSTS LIMITED TO STRONGER BANDS MOVING ACROSS THE TERMINALS MIXING STRONGER WINDS ALOFT DOWN BRIEFLY. HRRR AND HIRESW-ARW MODEL HAVE A GOOD HANDLING ON BANDED PRECIPITATION MOVING ACROSS THE REGION THROUGH TONIGHT. TIMING OF BANDS WILL BE DIFFICULT TO ACCURATELY PREDICT BUT AS ANA TRANSITIONS TO MORE EXTRATROPICAL THIS EVENING AND TONIGHT BANDED PRECIPITATION WILL BECOME MORE STARTIFORM WITH LOWER CEILINGS. AS ANA PULLS AWAY WINDS WILL SHIFT TO THE SW THEN W IN THE MORNING AFTER 12Z. LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... ANA REMNANT LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT, HOWEVER RESIDUAL LOW LEVEL MOISTURE AND SCATTERED PRECIPITATION MAY SUPPORT SUB-VFR CONDITIONS THRU TUESDAY MORNING. MIXING WILL SCATTER OUT CLOUD COVER BY MIDDAY TUESDAY THEN SCATTERED SHOWER AND THUNDERSTORMS (SOME OF WHICH CUD BE STRONG/SEVERE) AFFECT THE AREA TUESDAY AFTERNOON AND EVENING. DRYING AIRMASS BUILDS IN AFTER A COLD FRONT PASSAGE LATE TUESDAY NIGHT WITH PREDOMINATE VFR EXPECTED THEREAFTER. && .MARINE... AS OF 345 PM SUNDAY...GUSTY S TO SE WINDS THIS AFTERNOON MAINLY 20 TO 25 KT SOUTHERN WATERS WITH LIGHTER WINDS NORTHERN WATERS AROUND 10 TO 15 KTS. SEAS IN THE 7-9 FOOT RANGE SOUTHERN WATERS TO 3 TO 5 FEET NORTHERN WATERS. THE REMNANTS OF ANA WILL LIFT NORTHEAST ACROSS THE COASTAL PLAIN OVERNIGHT WITH WINDS BECOMING SOUTHERLY AND INC ACROSS ALL WATERS AND THE PAMLICO SOUND. CURRENT SCA LOOKS IN GOOD SHAPE. LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... DESPITE DEPARTING ANA, MARINE WEATHER REMAINS ACTIVE THRU MUCH OF THIS WEEK. MODERATE TO STRONG SW WINDS AND LINGERING SEAS WILL KEEP SMALL CRAFT ADVISORIES LIKELY THRU TUESDAY NIGHT AHEAD OF A COLD FRONT PASSAGE LATE TUESDAY NIGHT OR EARLY WEDNESDAY. MAY BE A LULL IN SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY BEFORE STRONGER POST FRONTAL N/NE WINDS KICK UP AGAIN WED NIGHT INTO THURSDAY. WINDS/SEAS GRADUALLY RELAX THU NIGHT FRIDAY AS PRESSURE GRADIENT DECREASES AT THE COAST WITH HIGH BUILDING IN FROM THE NORTH. && .HYDROLOGY... FLOOD WATCH ISSUED THROUGH MON MORNING AS OCCASIONAL BANDS OF HEAVY SHOWERS PIVOT ACROSS E NC THROUGH LATE TONIGHT. THE HEAVIER SHOWERS WILL PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. HEAVIEST RAIN THREAT LOOKS TO OCCUR OVERNIGHT TONIGHT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...FLOOD WATCH THROUGH MONDAY MORNING FOR NCZ090>093-095-098. MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT WEDNESDAY FOR AMZ135-150. SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 4 AM EDT WEDNESDAY FOR AMZ156-158. && $$ SYNOPSIS...TL NEAR TERM...TL SHORT TERM...TL LONG TERM...BTC AVIATION...BTC MARINE...BTC/TL HYDROLOGY...TL/RF
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
142 PM EDT SUN MAY 10 2015 .SYNOPSIS... ANA WILL GRADUALLY WEAKEN AND MOVE NORTHWEST OVER NORTHERN SOUTH CAROLINA TODAY...THEN LIFT NORTHEAST INLAND FROM THE COAST TONIGHT AND MONDAY. A COLD FRONT APPROACHES FROM THE NORTHWEST TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1145 AM SUN...UPDATED FCST TO EXPIRE TROPICAL STORM WARNING. GUSTY SOUTH TO SE WINDS WILL CONTINUE ESP NEAR THE COAST THOUGH BIGGESET CONCERN WILL BE HEAVY RAIN THREAT TODAY. CONTINUED CATEGORICAL POPS WESTERN HALF OF FA WITH HIGH LIKELY TO SCT ACROSS THE FAR EAST. COULD SEE POCKETS OF SUNSHINE BREAK OUT BY THIS AFTERNOON AND THIS WOULD EXACERBATE THE HEAVY RAIN THREAT AS ANY INC IN INSTABILITY WILL AID IN CONVECTIVE SHOWER/TS COVERAGE LATER. PWATS APPROACHING 2 INCHES WHICH IS ABOVE THE MAX FOR EARLY TO MID MAY. PREV DISC...AS OF 725 AM SUNDAY...ISSUED FLOOD WATCH FOR SW TIER. RADAR AND SATL SHOW GOOD BANDING OF SHRA/ISOLD TSRA DEVELOPING E OF ANA AND THIS LOOKS TO TRAIN OVER SRN TIER. WITH PRECIP WTR VALUES APPROACHING 2 INCHES VERY HEAVY DOWNPOURS GOOD BET WITH POTENTIAL FOR SOME TRAINING AND POSSIBLE FOOD CONCERNS. PREV DISC...TROPICAL STORM ANA IS MOVING ASHORE NEAR MYRTLE BEACH EARLY THIS MORN. BANDS OF SHRA CONT TO ROTATE NW ACROSS THE SW HALF OF REGION AND THAT TREND SHLD CONT THRU THE MORN AS ANA SLOWLY MOVES NNW. LATER TODAY ANA WILL BEGIN TO TURN N BUT REMAIN SW OF ERN NC. WITH HEATING EXPECT CVRG OF SHRA/ISOLATED TSRA TO GRAD INCREASE ACROSS AREA...CONT TO HAVE POPS RANGING FROM CATEGORICAL OVER SRN SECTION TO CHC NE. LOCALLY HEAVY RAIN LIKELY WITH PRECIP WTR VALUES REACHING NEAR 2 INCHES SRN TIER. SO FAR HAVE NOT SEEN ANY SIGN OF ORGANIZED ROTATION IN ANY OF THE CELLS OR BANDS OF SHRA/ISOLD TSRA. LATER TODAY WITH SOME HEATING MAY SEE SLIGHTLY BETTER CHC OF TORNADO AS AREA BEGINS TO GET IN RIGHT FLANK OF THE CIRC...ESPCLY S. HIGH IN THE UPR 70S TO LOWER 80S...GUSTY SE WINDS SRN AREAS CLOSER TO TS ANA. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... AS OF 225 AM SUNDAY...ANA WILL GRAD WEAKEN BUT SHLD SEE WELL DEFINED CIRC MOVE NNE NEAR OR JUST E OF I95 OVERNIGHT. EXPECT NUMEROUS SHRA/ISOLATED TSRA TO CONT WITH LOCALLY HEAVY RAIN A GOOD BET AS TROP MOISTURE STREAMS N OVER ERN NC. TORNADO CHCS WILL INCREASE OVERNIGHT AS ERN NC WILL BE IN MOST FAVORABLE RIGHT FLANK OF THE CIRC...INSTAB IS WEAK AND THIS MAY LIMIT THREAT SOMEWHAT BUT CERTAINLY THERE WILL BE A CHC OF A TORNADO OR TWO WITH FAVORABLE SHEAR OVER THE REGION. GUSTY MAINLY SE TO S WINDS EXPECTED ESPCLY COAST WITH MILD LOWS IN THE UPR 60S TO LOWER 70S. && .LONG TERM /MONDAY THROUGH SUNDAY/... AS OF 329 AM SUN...REMNANTS OF TROPICAL STORM ANA WILL BE PUSHING TOWARD THE NORTHEAST DURING THE DAY ON MONDAY. PRECIPITABLE WATERS AROUND TWO INCHES COMBINED WITH ELEVATED CAPE AND GOOD DIRECTIONAL /SPEED SHEAR WILL LEAD TO AN ACTIVE DAY WITH FLOODING AND ISOLATED TORNADOES POSSIBLE. UPPER TROUGH OVER THE CENTRAL PART OF THE COUNTRY WILL DRAG A COLD FRONT TO NORTH CAROLINA ON TUESDAY. SOUTH SOUTHWESTERLY FLOW AHEAD OF THE APPROACHING FRONT WILL CONTINUE THE CHANCE OF THUNDERSTORM ACTIVITY ON TUESDAY WITH HIGH TEMPERATURES IN THE UPPER 80S. FRONT EXPECTED TO EXIT OFF THE COAST ON WEDNESDAY MORNING WITH PRECIPITATION CHANCES ENDING. HIGH PRESSURE WILL BUILD OVER THE AREA WITH HIGH TEMPERATURES DROPPING A COUPLE OF CATEGORIES INTO THE UPPER 70S TO LOWER 80S THROUGH THE REMAINDER OF THE WORK WEEK. MODELS HINTING AT A WEAK FRONT MOVING THROUGH NORTH CAROLINA OVER THE WEEKEND WITH A SMALL CHANCE OF RAIN ASSOCIATED WITH IT. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... SHORT TERM /THROUGH 12Z MONDAY/... AS OF 130 PM SUN...VFR/MVFR CONDITIONS OVER EASTERN NORTH CAROLINA TAFS AS CENTER OF ANA MOVES NORTH INTO NC TO OUR SW. RAIN BANDS ROTATING ACROSS REGION FROM OFFSHORE EXTENDS FROM ONSLOW/CARTERET COUNTY TO THE NW AS IT CONTINUES TO PUSH TO THE NORTH AND AFFECTING KEWN AND KPGV REDUCING CIGS TO MVFR. EXPECT TO SEE MORE STEADY RAIN STARTING IN LATER THIS AFTERNOON AS CENTER OF ANA MOVES SLOWLY NORTH. HAVE MODERATE CONFIDENCE IN MVFR CONDITIONS ACROSS ALL TERMINALS WITH ISOLATED IFR CONDITIONS. WINDS HAVE NOT BEEN AN ISSUE WITH GUSTS LIMITED TO STRONGER BANDS MOVING ACROSS THE TERMINALS MIXING STRONGER WINDS ALOFT DOWN BRIEFLY. HRRR AND HIRESW-ARW MODEL HAVE A GOOD HANDLING ON BANDED PRECIPITATION MOVING ACROSS THE REGION THROUGH TONIGHT. TIMING OF BANDS WILL BE DIFFICULT TO ACCURATELY PREDICT BUT AS ANA TRANSITIONS TO MORE EXTRATROPICAL THIS EVENING AND TONIGHT BANDED PRECIPITATION WILL BECOME MORE STARTIFORM WITH LOWER CEILINGS. AS ANA PULLS AWAY WINDS WILL SHIFT TO THE SW THEN W IN THE MORNING AFTER 12Z. LONG TERM /MON THROUGH THURSDAY/... AS OF 346 AM SUN...REMNANTS OF ANA WILL BE MOVING THROUGH THE EASTERN NORTH CAROLINA TAF SITES ON MONDAY WITH WIDSPREAD SUB VFR CONDITIONS EXPECTED THROUGH THE DAY. RAIN...GUSTY WINDS...AND SEVERE WEATHER WITH TORNADOES A POSSIBILITY. LLWS AND CROSS WIND ALSO EXPECTED. ANA WILL EXIT THE AREA MONDAY NIGHT WITH IMPROVING CONDITIONS. A FRONT WILL APPROACH THE AREA WITH SUBVFR CONDITIONS POSSIBLE TUESDAY AND TUESDAY EVENING AHEAD OF THE FRONT IN RAIN AND LOW CLOUDS. VFR CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE FORECAST PERIODS WITH HIGH PRESSURE OVER THE AREA. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 1145 AM SUNDAY...UPDATED TO EXPIRE TS WARNING FOR THE SOUTHERN WATERS. GUSTY S TO SE WINDS TODAY MAINLY 20 TO 30 KT WITH LIGHTER WINDS NORTHERN WATERS AROUND 10 TO 15 KTS. SEAS WILL BE 8 TO 10 FEET SOUTHERN WATERS TO AND SEAS 3 TO 5 FT OVR NRN WTRS. THE STRONG ONSHORE FLOW WILL KEEP SURF ROUGH OVER BEACHES FROM HAT S. ANA OR ITS REMNANTS WILL LIFT NNE TONIGHT INLAND FROM THE COAST. WINDS WILL DIMINISH A BIT SRN TIER AS ANA WEAKENS...HOWEVER SPEEDS SHLD INCREASE ACROSS CNTRL AND NRN TIER TO THE E OF THE CIRC...HAVE STARTED SCA FOR PAMLICO SOUND AND NRN CSTL WTRS LATER THIS EVENING. SEAS WILL SUBSIDE TO 7 TO 9 FEET S OVERNIGHT AND BUILD TO 5 TO 7 FEET FAR N. LONG TERM /MON THROUGH THURSDAY/... AS OF 350 AM SUN...SMALL CRAFT ADVISORY CONDITIONS EXPECTED MONDAY AS REMNANTS OF TROPICAL STORM ANA MOVE NORTH THROUGH NORTH CAROLINA. DEPENDING ON HOW DEEP THE LOW GETS...MAY SEE GALE CONDITIONS REALIZED DURING THE DAY. SEAS EXPECTED TO BE 8 TO 10 FEET. CONDITIONS MAY BRIEFLY DROP BELOW SMALL CRAFT ADVISORY CRITERIA TUESDAY MORNING. HOWEVER AN APPROACHING COLD FRONT WILL TIGHTEN THE GRADIENT AGAIN FOR SMALL CRAFT POSSIBLE BY LATE TUESDAY. FRONT WILL MOVE THROUGH THE WATERS WEDNESDAY WITH HIGH PRESSURE BUILDING IN THROUGH THE REMAINDER OF THE FORECAST PERIOD. && .HYDROLOGY... FLOOD WATCH ISSUED THROUGH MON MORNING AS BANDS OF HEAVY SHOWERS PIVOT ACROSS E NC THROUGH TONIGHT. THE HEAVIER SHOWERS WILL PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. WILL HAVE TO MONITOR FOR POTENTIAL EXPANSION OF THE FLOOD WATCH FURTHER EAST LATER ON ACCORDING TO RADAR TRENDS AND MOVEMENT OF REMNANTS OF ANA. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...FLOOD WATCH THROUGH MONDAY MORNING FOR NCZ090>093-095-098. MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT WEDNESDAY FOR AMZ135-150. SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154. SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR AMZ156-158. && $$ SYNOPSIS...RF NEAR TERM...RF/TL SHORT TERM...RF LONG TERM...CCG AVIATION...CCG/MAC MARINE...CCG/RF/TL HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1256 AM CDT SUN MAY 10 2015 .UPDATE... ISSUED AT 1245 AM CDT SUN MAY 10 2015 THE DEVELOPING SPRING STORM REMAINS THE FOCUS THIS MORNING. RECENT RADAR/SATELLITE IMAGERY AND SURFACE OBSERVATION VALIDATION INDICATE THAT PRECIPITATION REMAINS UNFROZEN AND GENERALLY SOUTHEAST OF A LINE FROM AMIDON TO CARRINGTON. UPDATES TO THE QPF AND SNOW AMOUNTS WERE BASED ON THIS INFORMATION...ALONG WITH WPC QPF A LITTLE FURTHER SOUTH THROUGH 12 UTC THIS MORNING. WHILE THIS DOES NOT GREATLY REDUCE SNOWFALL FORECASTS...IT DOES PUSH BACK THE START OF SNOW ACCUMULATION A FEW HOURS. UPDATE ISSUED AT 926 PM CDT SAT MAY 9 2015 JUST GETTING A LOOK AT LATEST NAM IN THROUGH 36 HOURS. NOT SEEING SNOW YET WHERE NAM H850 TEMPS ARE MARGINALLY CLOSE TO SNOW TYPE ACROSS NORTHWEST SD AND SOUTHWEST ND. LOWER BOUNDARY LAYER TEMPS STILL TOO WARM AS OF YET. DO THINK THERE WILL BE A CHANGE OVER TO SNOW AFTER MIDNIGHT SOUTHWEST WHERE H850 TEMP IS CLOSE TO -3 C ON NAM. STILL A LOT OF UNCERTAINTY OUTSIDE OF THE SOUTHWEST. WILL LET THE WINTER STORM WATCH BEGIN AT 06Z AS PLANNED NORTH OF WARNING AREA AND AFTER 12Z NORTH AND EAST OF MISSOURI RIVER. UPDATE ISSUED AT 701 PM CDT SAT MAY 9 2015 THIS UPDATE WILL MAINLY CONCERN CLOUDS AND WINDS AS PRECIP JUST MOVING INTO THE REGION AT THIS TIME. WITH A NORTHEAST WIND SOME EVAPORATION OCCURRING BELOW CLOUD BASE WHICH WILL EVENTUALLY SATURATE THE LAYERS TONIGHT. UPDATED CURRENT TEMPS...WINDS...AND CLOUDS. WILL WAIT FOR A NEW RUNS LATER THIS EVENING OF SOME SHORT RANGE MODELS HRRR FOR FURTHER REFINEMENTS. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 311 PM CDT SAT MAY 9 2015 IMPENDING WINTER STORM DOMINATES THE FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD. 12Z MODELS IN DECENT AGREEMENT WITH MAIN FEATURES. CURRENTLY...DEEP LOW PRESSURE SWINGING EAST ACROSS THE CENTRAL ROCKIES...WHICH WILL LIFT NORTHEAST INTO THE HIGH PLAINS TONIGHT. SFC RIDGE OF HIGH PRESSURE STRETCHING FROM LAKE WINNIPEG SOUTHWEST THROUGH NORTHEASTERN NORTH DAKOTA INTO SOUTHWESTERN ND. EMBEDDED S/WV IMPULSES CONTINUE TO LIFT NORTH OUT OF THE UPPER LOW ACROSS THE DAKOTAS...TRIGGERING PRECIPITATION MAINLY ON THE SOUTHERN EDGE AND ALONG TO EAST OF THE SFC RIDGE AXIS. CLEAR TO PARTLY CLOUDY ACROSS MY NORTH WITH STRONGER SUBSIDENCE NEAR THE SFC RIDGE. PRECIPITATION MAINLY IN THE FORM OF RAIN WILL CONTINUE TO DEVELOP ACROSS MY FAR SOUTH AND SOUTHEASTERN QUARTER NOW INTO THIS EVENING WHILE DRIER CONDITIONS LINGER WEST AND NORTH. SFC RIDGE WASHES OUT/LIFTS NORTH THIS EVENING INTO THE OVERNIGHT WITH A SFC TROUGH DEVELOPING ACROSS EASTERN SOUTH DAKOTA INTO THE JAMES RIVER BASIN. PRECIPITATION BAND DEVELOPS IN EARNEST ACROSS SOUTH DAKOTA OVERNIGHT...LIFTING NORTH ACROSS SOUTHWEST AND CENTRAL NORTH DAKOTA LATE TONIGHT INTO SUNDAY AS THE UPPER LOW LUMBERS NORTH INTO SOUTH DAKOTA. INHERITED POP GRIDS LOOKED GOOD SO ONLY SOME MINOR TWEAKS WERE MADE. SIGNIFICANT SNOWFALL LIKELY WHERE CURRENT WINTER STORM WARNINGS ARE IN EFFECT. THERMAL PROFILES ARE MORE SUPPORTIVE OF ALL SNOW OR MAINLY SNOW WEST OF THE MISSOURI RIVER AND ALONG AND SOUTH OF INTERSTATE 94 WHERE THERE IS VERY NICE MODEL AGREEMENT ON COOLING 925/850MB TEMPS DUE IN PART TO DYNAMIC COOLING AND ALSO MID LEVEL CAA. STILL LINGERING UNCERTAINTY NORTH AND EAST OF THIS AREA WHERE TEMPS ALOFT ARE SLIGHTLY WARMER AND THE BIG QUESTION IS EVENTUAL SFC TEMPERATURES TONIGHT INTO SUNDAY. 2-3 DEGREES WILL HAVE SIGNIFICANT IMPACTS TO PRECIP TYPE FOR THIS AREA...AND THUS SNOW ACCUMULATIONS. FOR EXAMPLE...I RAN TWO SCENARIOS FOR BISMARCK ON TONIGHT THROUGH SUNDAY. THE FIRST WAS A MORE AVERAGE SOLUTION FOR TEMPERATURES WHERE I GOT 1-3 INCHES OF WET SNOW THROUGH SUNDAY AFTERNOON (THIS WAS UTILIZED FOR THIS FORECAST PACKAGE). THE SECOND SCENARIO WAS 2 DEGREES COOLER...WHICH RESULTED IN 6-9 INCHES (THIS WAS NOT USED). OPTED TO UPGRADE MORTON COUNTY TO A WINTER STORM WARNING BASED ON FORECAST TEMPS ALOFT (AS DISCUSSED ABOVE). WILL KEEP THE REMAINDER OF THE WATCH AS IS THROUGH SUNDAY DUE TO THE LINGERING UNCERTAINTY (SEE LONG TERM BELOW FOR WATCH EXTENSION DISCUSSION). .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 311 PM CDT SAT MAY 9 2015 A STRONG SPRING STORM WILL LINGER THROUGH MONDAY EVENING. THIS WILL BE THE MAIN FOCUS FOR THE LONG TERM FORECAST. THE 12 UTC MODELS ARE IN FAIRLY GOOD AGREEMENT WITH RESPECT TO TIMING AND LOCATION OF THE HEAVIEST PRECIPITATION AND EVOLUTION OF THE STORM SUNDAY INTO MONDAY. THE 12 UTC GEM AND NAM APPEAR TO BE ON THE FRINGES WITH THE FORMER LIKELY TOO WET AND TOO FAR TO THE WEST AND THE LATER TO DRY AND TOO FAR TO THE EAST. FOR THIS FORECAST UTILIZED A BLEND OF THE GFS/ECMWF/SREF. THE WINTER STORM WATCH HAS BEEN EXPANDED A LITTLE FURTHER TO THE EAST AS THERE IS AN INCREASED POTENTIAL FOR ACCUMULATING SNOW ACROSS PORTIONS OF THE JAMES RIVER VALLEY. SUNDAY EVENING AND OVERNIGHT...MODERATE TO HEAVY PRECIPITATION IS EXPECTED TO SPREAD EAST OF THE MISSOURI RIVER AND ALONG I-94 AS A DEEP SURFACE LOW PROPAGATES ACROSS THE EASTERN DAKOTAS. A TROWAL...COUPLED WITH STRONG FRONTOGENETIC FORCING WILL LIKELY PRODUCE HEAVY BANDS OF RAIN/SNOW. AS MUCH AS THREE INCHES OF LIQUID IS POSSIBLE EAST OF THE MISSOURI RIVER AND ALONG/SOUTH OF I-94. THE 12 UTC RUNS CONTINUE TO INDICATE H85 TEMPERATURES AROUND -2C TO -3C AND SURFACE TEMPERATURES HOVERING NEAR FREEZING. THIS IN TURN COULD LEAD TO ACCUMULATIONS OF HEAVY WET SNOW. AS SUCH ISSUED A WATCH FOR PORTIONS OF THE JAMES RIVER VALLEY. HOWEVER...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO PRECIPITATION TYPE AS A FEW DEGREES DIFFERENCE IN SURFACE TEMPERATURE COULD MEAN THE DIFFERENCE BETWEEN NO SNOW AND 6+ INCHES. IN ADDITION TO HEAVY PRECIPITATION...THIS POTENT STORM WILL ALSO PRODUCE STRONG WINDS. AS THE LOW WRAPS UP ACROSS THE EASTERN DAKOTAS...THE PRESSURE GRADIENT WILL STEEPEN. WINDS AROUND 35 MPH WILL BE LIKELY SUNDAY AND MONDAY. DUE TO THE TIMING (RATHER LATE IN THE SEASON FOR SNOW) AND POTENTIAL IMPACTS FELT IT WAS NECESSARY TO ISSUE A WATCH AND GIVE A HEADS UP...BUT CONFIDENCE WAS NOT HIGH ENOUGH TO WARRANT A MAJOR ALERT. PRECIPITATION WILL CONTINUE ACROSS MAINLY CENTRAL AND EASTERN PORTIONS OF NORTH DAKOTA THROUGH MONDAY. NORTHWEST NORTH DAKOTA MAY GET LEFT HIGH AND DRY. TEMPERATURES ACROSS THE SOUTH AND EAST WILL STRUGGLE TO GET OUT OF THE 30S AND 40S OVER THE NEXT SEVERAL DAYS...WHILE THE NORTHWEST MAY REACH THE 50S AND 60S. THERE WILL BE ADDITIONAL CHANCES FOR RAIN WEDNESDAY/THURSDAY...WITH A WARM UP EXPECTED LATE WEEK INTO THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1245 AM CDT SUN MAY 10 2015 SIGNIFICANT SPRING SNOW STORM WILL IMPACT SOUTHERN NORTH DAKOTA BEGINNING TONIGHT. VFR AND MVFR CONDITIONS WILL SLOWLY DETERIORATE AT KDIK/KBIS/KJMS. CONDITIONS WILL CONTINUE THROUGH SUNDAY. && .BIS WATCHES/WARNINGS/ADVISORIES... WINTER STORM WATCH THROUGH MONDAY MORNING FOR NDZ020-033-040. WINTER STORM WARNING UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NDZ034- 041>045. WINTER STORM WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY EVENING FOR NDZ022-023-035>037-046-047. && $$ UPDATE...SCHECK SHORT TERM...NH LONG TERM...AJ AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS NORMAN OK
655 AM CDT SUN MAY 10 2015 .AVIATION... CONVECTION THIS MORNING SHOULD MAINLY INFLUENCE OKC/OUN/PNC THROUGH 15Z. THE RAIN SHOULD ALSO HELP TO IMPROVE IFR CONDITIONS AT THESE SITES. A COLD FRONT WILL SWEEP ACROSS THE AREA THIS MORNING INTO TONIGHT. THE FRONT MAY ALSO HELP WITH THE DEVELOPMENT OF STORMS LATER THIS AFTERNOON...MAINLY AT LAW/OKC/OUN. OTHERWISE...LOW CEILINGS AND FOG AT CSM/GAG/WWR SHOULD IMPROVE BY 14Z. && .PREV DISCUSSION... /ISSUED 430 AM CDT SUN MAY 10 2015/ DISCUSSION... YET ANOTHER ROUND OF CONVECTION IS SET TO MOVE INTO PART OF WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA OVER THE NEXT SEVERAL HOURS. THE HRRR HAS BEEN FAIRLY CONSISTENT IN MOVING THIS COMPLEX ACROSS AREAS SOUTH AND EAST OF I-44 THROUGH THE MID TO LATE MORNING...WITH ADDITIONAL STORMS IN SOUTHEAST OKLAHOMA THIS AFTERNOON. MOST MEDIUM RANGE MODELS ARE SIMILAR WITH THE HRRR...BUT CONTINUE CONVECTION OVER SOUTH CENTRAL AND SOUTHEAST OKLAHOMA INTO THE AFTERNOON/EVENING. AREAS ALONG AND SOUTHEAST OF SEMINOLE...PAULS VALLEY AND HENRIETTA...TEXAS MAY SEE ANOTHER 2 TO 4 INCHES OF RAIN THROUGH THE AFTERNOON/EVENING WHICH WILL RESULT IN SIGNIFICANT FLASH FLOODING. THE MAIN HAZARDS WITH THE MORNING CONVECTION WILL BE LARGE HAIL...AND FLOODING RAINFALL. DEPENDING ON HOW MUCH CONVECTION LINGERS OVER SOUTHEAST OKLAHOMA...ADDITIONAL THUNDERSTORMS MAY DEVELOP ACROSS NORTH CENTRAL...CENTRAL AND SOUTHWEST OKLAHOMA AS A COLD FRONT APPROACHES...SIMILAR TO THE 06Z NAM. INSTABILITY AND SHEAR WILL SUPPORT THE RISK OF VERY LARGE HAIL AND DAMAGING WINDS. A COLD FRONT WILL SWEEP ACROSS ALL OF OKLAHOMA AND WESTERN NORTH TEXAS BY EARLY MONDAY...WHICH WILL BRING A MUCH NEEDED BREAK FROM SEVERE STORMS AND FLOODING RAIN. ANOTHER SHORT WAVE TROUGH IS FORECAST TO LIFT ACROSS THE CENTRAL PLAINS ON WEDNESDAY...WITH ANOTHER ACTIVE SOUTHWEST FLOW PERIOD FROM FRIDAY INTO NEXT WEEKEND. FOR NOW...WILL LEAVE THE FLOOD WATCH THE SAME...BUT SHOULD BE ABLE TO REMOVE NORTHWEST PARTS OF THE WATCH LATER THIS AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 76 51 70 50 / 60 40 0 0 HOBART OK 78 49 70 48 / 20 10 0 0 WICHITA FALLS TX 78 55 72 51 / 70 20 10 0 GAGE OK 74 43 68 43 / 0 10 0 0 PONCA CITY OK 77 48 69 45 / 50 40 0 0 DURANT OK 76 60 75 54 / 90 80 20 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FLOOD WATCH THROUGH MONDAY MORNING FOR OKZ006>008-011>013- 015>048-050>052. TX...FLOOD WATCH THROUGH MONDAY MORNING FOR TXZ083>090. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
430 AM CDT SUN MAY 10 2015 .DISCUSSION... YET ANOTHER ROUND OF CONVECTION IS SET TO MOVE INTO PART OF WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA OVER THE NEXT SEVERAL HOURS. THE HRRR HAS BEEN FAIRLY CONSISTENT IN MOVING THIS COMPLEX ACROSS AREAS SOUTH AND EAST OF I-44 THROUGH THE MID TO LATE MORNING...WITH ADDITIONAL STORMS IN SOUTHEAST OKLAHOMA THIS AFTERNOON. MOST MEDIUM RANGE MODELS ARE SIMILAR WITH THE HRRR...BUT CONTINUE CONVECTION OVER SOUTH CENTRAL AND SOUTHEAST OKLAHOMA INTO THE AFTERNOON/EVENING. AREAS ALONG AND SOUTHEAST OF SEMINOLE...PAULS VALLEY AND HENRIETTA...TEXAS MAY SEE ANOTHER 2 TO 4 INCHES OF RAIN THROUGH THE AFTERNOON/EVENING WHICH WILL RESULT IN SIGNIFICANT FLASH FLOODING. THE MAIN HAZARDS WITH THE MORNING CONVECTION WILL BE LARGE HAIL...AND FLOODING RAINFALL. DEPENDING ON HOW MUCH CONVECTION LINGERS OVER SOUTHEAST OKLAHOMA...ADDITIONAL THUNDERSTORMS MAY DEVELOP ACROSS NORTH CENTRAL...CENTRAL AND SOUTHWEST OKLAHOMA AS A COLD FRONT APPROACHES...SIMILAR TO THE 06Z NAM. INSTABILITY AND SHEAR WILL SUPPORT THE RISK OF VERY LARGE HAIL AND DAMAGING WINDS. A COLD FRONT WILL SWEEP ACROSS ALL OF OKLAHOMA AND WESTERN NORTH TEXAS BY EARLY MONDAY...WHICH WILL BRING A MUCH NEEDED BREAK FROM SEVERE STORMS AND FLOODING RAIN. ANOTHER SHORT WAVE TROUGH IS FORECAST TO LIFT ACROSS THE CENTRAL PLAINS ON WEDNESDAY...WITH ANOTHER ACTIVE SOUTHWEST FLOW PERIOD FROM FRIDAY INTO NEXT WEEKEND. FOR NOW...WILL LEAVE THE FLOOD WATCH THE SAME...BUT SHOULD BE ABLE TO REMOVE NORTHWEST PARTS OF THE WATCH LATER THIS AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 76 51 70 50 / 60 40 0 0 HOBART OK 78 49 70 48 / 20 10 0 0 WICHITA FALLS TX 78 55 72 51 / 70 20 10 0 GAGE OK 74 43 68 43 / 0 10 0 0 PONCA CITY OK 77 48 69 45 / 50 40 0 0 DURANT OK 76 60 75 54 / 90 80 20 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FLOOD WATCH THROUGH MONDAY MORNING FOR OKZ006>008-011>013- 015>048-050>052. TX...FLOOD WATCH THROUGH MONDAY MORNING FOR TXZ083>090. && $$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
226 PM PDT SUN MAY 10 2015 .DISCUSSION...CURRENT VISIBLE IMAGE SHOWS CUMULUS ALREADY STARTING TO BUILD UP ALONG THE CASCADES AND FROM THE SCOTT VALLEY TO THE TRINITY ALPS AND AND SISKIYOUS IN NORTHERN CAL AND ARE MOVING NORTHEAST. THE PAST SEVERAL RUNS OF THE HRRR MODEL (WHICH IS UPDATED HOURLY) CONTINUES TO SHOW SOME CONVECTIVE SHOWERS IN THE ABOVE MENTION AREAS IN ADDITION TO SOUTH THROUGH EASTERN JACKSON COUNTY AND NORTHERN KLAMATH COUNTY. THE MODELS SUGGEST THERE`S ENOUGH INSTABILITY FOR ISOLATED THUNDERSTORMS LATE THIS AFTERNOON INTO THIS EVENING. THE 700 MB WINDS ARE FROM THE SOUTHWEST, SO SHOWERS AND ISOLATED STORMS THAT DEVELOP WILL GENERALLY MOVE NORTHEAST. ISOLATED STORMS WILL END THIS EVENING AS WE LOSE DAYTIME HEATING, BUT INSTABILITY SHOWERS WILL CONTINUE OVERNIGHT AS THE UPPER TROUGH CURRENTLY NEAR 45N/130W DIGS SOUTH TOWARDS THE OREGON COAST. THE UPPER TROUGH WILL EVOLVE INTO AN UPPER LOW AND THIS WILL BE RESPONSIBLE FOR BRINGING MUCH COOLER TEMPERATURES...SCATTERED SHOWERS JUST ABOUT ANYWHERE IN THE FORECAST AREA MONDAY AND TUESDAY. IN ADDITION, ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF THE CASCADES BOTH MONDAY AND TUESDAY AFTERNOON AND EARLY EVENING. THE UPPER TROUGH WILL DIG SOUTH AND BECOME AND UPPER LOW MONDAY... REACH THE OREGON COAST MONDAY AFTERNOON, THEN MOVE OVER THE AREA MONDAY NIGHT INTO TUESDAY. THE MODELS HAVE COME INTO BETTER AGREEMENT WITH THE PLACEMENT OF THE UPPER LOW WHICH YIELDS HIGHER CONFIDENCE WE`LL BE COOL AND WET FOR THE START OF NEXT WEEK. THE MODELS ALSO SHOW THE GREATEST INSTABILITY ALONG AND EAST OF THE CASCADES AND PLENTY OF SHORTWAVES WILL MOVE OUT AHEAD OF THE UPPER LOW MONDAY PROVIDING THE TRIGGER FOR ISOLATED STORMS TO FIRE UP. THE UPPER LOW WILL MOVE OVERHEAD ON TUESDAY BRINGING COLD AIR ALOFT WITH 500 MB TEMPERATURES BETWEEN -25 AND -28C. SHOWERS WILL OCCUR JUST ABOUT ANYWHERE TUESDAY WITH SOME MODERATE TO HEAVY IN THE AFTERNOON AS WE REACH MAX HEATING. SNOW LEVELS TUESDAY ARE EXPECTED TO BE AROUND 5000 FEET, BUT WILL TEMPORARILY LOWER IN HEAVIER SHOWERS. RIGHT NOW, WERE ONLY EXPECTING SNOW TO ACCUMULATE OVER THE HIGHER TERRAIN ALONG AND EAST OF THE CASCADES. ISOLATED THUNDERSTORMS REMAIN A CONCERN TUESDAY AFTERNOON ALONG AND EAST OF THE CASCADES. SHOWERS ARE EXPECTED TO GRADUALLY DECREASE TUESDAY NIGHT AS THE UPPER LOW WEAKENS AND MOVES NORTH. HOWEVER THE NAM SHOW ANOTHER SHORTWAVE ON THE HEALS OF THE UPPER TROUGH AND WE COULD SEE SHOWERS INCREASE AGAIN EARLY WEDNESDAY MORNING. THE GFS IS SLOWER WITH THE NEXT SHORTWAVE AND EC IS ALSO SLOWER AND WEAKER. EITHER ONE OF THESE SOLUTIONS WILL RESULT IN A COOL AND UNSETTLED PATTERN ON WEDNESDAY. -PETRUCELLI && .AVIATION...FOR THE 10/18Z TAF CYCLE...A LOW PRESSURE SYSTEM WILL BRING SOME ISOLATED THUNDERSTORMS AND SHOWERS OVER INLAND AREAS THROUGH THIS EVENING...THEN EXPECT SHOWERS TO MOVE INLAND OVER THE AREA TONIGHT AND MONDAY MORNING ALONG THE COAST...VFR CONDITIONS WILL CONTINUE THIS AFTERNOON...THEN MVFR CIGS ARE EXPECTED TO DEVELOP AROUND 00Z AND PERSIST THROUGH THE EVENING. OVERNIGHT THROUGH MONDAY MORNING...EXPECT A MIX OF VFR/MVFR CIGS ALONG THE COAST. INLAND...VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING. HOWEVER ISOLATED THUNDERSTORMS ARE EXPECTED ALONG FROM THE SISKIYOUS AND WESTERN SLOPES OF THE CASCADES AND EASTWARD LATE THIS AFTERNOON AND THIS EVENING. THIS MAY BRING SOME ISOLATED MVFR CIGS TO THESE AREAS ALONG WITH VARIABLE AND GUSTY WINDS. THEN AS SHOWERS MOVE INLAND OVERNIGHT, EXPECT WIDESPREAD MVFR CIGS LATE THIS EVENING INTO TONIGHT...CONTINUING INTO MONDAY MORNING. WIDESPREAD MOUNTAIN OBSCURATIONS ARE ALSO EXPECTED LATE THIS EVENING THROUGH MONDAY MORNING. /CC && .MARINE...UPDATED 145 PM PDT SUNDAY, MAY 10, 2015...A DRY COLD FRONT MOVING THROUGH THE WATERS THIS AFTERNOON WILL CAUSE NORTH WINDS TO INCREASE THROUGH EARLY MONDAY. THESE INCREASING NORTH WINDS WILL RESULT IN STEEP SEAS FOR MOST OF THE WATERS BEYOND 10 MILES OF THE COAST AND INNER WATERS SOUTH OF PORT ORFORD. THESE SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED TO LINGER THROUGH MONDAY NIGHT. SHOWERS ARE EXPECTED MONDAY EVENING THROUGH WEDNESDAY. WINDS AND SEAS WILL DIMINISH ON TUESDAY AND ARE LIKELY REMAIN BELOW ADVISORY LEVELS THROUGH THURSDAY. -SCHAAF .FIRE WEATHER...UPDATED 100 PM PDT SUNDAY, MAY 10, 2015...A WEAK COLD FRONT WILL PERSIST OVER THE AREA THIS AFTERNOON AND EVENING ALLOWING SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP FROM ABOUT THE SHASTA AND SCOTT VALLEYS NORTHWARD TO THE SISKIYOUS AND INTO THE CASCADES THIS AFTERNOON. STORMS ARE ALSO POSSIBLE ALONG THE WESTERN SLOPES OF THE CASCADES AND INTO PORTIONS OF THE ROGUE VALLEY LATE THIS AFTERNOON. THEN THIS EVENING...EXPECT ISOLATED THUNDERSTORMS FROM THE CASCADES EASTWARD. MID-LEVEL SOUTHWEST FLOW WITH NORTHWEST FLOW IN THE LOWER LEVELS WILL CAUSE WINDS AND MOISTURE TO CONVERGE IN THESE AREAS AND MODELS CONTINUE TO SHOW INSTABILITY WITH THE POTENTIAL FOR ISOLATED THUNDERSTORMS. STORMS SHOULD GENERALLY PRODUCE RAINFALL, THOUGH AMOUNTS ARE LIKELY TO BE LIGHT TO MODERATE AT 0.10" TO 0.25" OR LESS. STORMS ARE EXPECTED TO MOVE FROM SOUTHWEST TO NORTHEAST AT 10-20 KNOTS. THE STORMS WILL CAPABLE OF GUSTY OUTFLOW WINDS OF 25 TO 35 MPH AND SMALL HAIL. GUSTY WEST TO SOUTHWEST WINDS ARE EXPECTED AHEAD OF THE FRONT OVER THE EAST SIDE THIS AFTERNOON, WITH GUSTY NORTHWEST WINDS BEHIND IT ON THE WEST SIDE. SCATTERED SHOWERS ACROSS THE AREA TONIGHT WILL INCREASE IN COVERAGE AND INTENSITY MONDAY MORNING THROUGH MONDAY EVENING AS AN UPPER LOW MOVES INTO THE COAST. ISOLATED THUNDERSTORMS MIXED WITH SHOWERS ARE EXPECTED ON THE EAST SIDE MONDAY AFTERNOON AND EVENING, PRIMARILY FOR EASTERN SISKIYOU, MODOC, EASTERN KLAMATH AND LAKE COUNTIES. THEN SHOWERS AND ISOLATED THUNDERSTORMS ARE LIKELY OVER MUCH OF THE AREA ON TUESDAY AS THE UPPER LEVEL LOW MOVES OVERHEAD. /CC && .MFR WATCHES/WARNINGS/ADVISORIES... OR...NONE. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING TO 11 PM PDT MONDAY FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FOR WINDS FROM 2 AM TO 11 PM PDT MONDAY FOR PZZ376. $$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
921 AM PDT SUN MAY 10 2015 .DISCUSSION...MADE A FEW ADJUSTMENTS TO THE FORECAST FOR TODAY. CURRENT VISIBLE IMAGE SHOWS A CIRRUS SHIELD MOVING OVER THE REGION THIS MORNING WHICH WILL INITIALLY LIMIT THE AMOUNT OF SURFACE HEATING, BUT THIS WILL MOVE EAST LATE THIS MORNING. WHAT MAY HAPPEN IS ISOLATED STORMS WILL BE DELAYED UNTIL LATE THIS AFTERNOON. THE CIRRUS SHIELD IS THINNER IN SISKIYOU COUNTY, SO IT WILL HAVE LITTLE OR NO EFFECT ON SURFACE HEATING THERE AND ISOLATED STORMS COULD DEVELOP THERE EARLY THIS AFTERNOON. ALSO THE LATEST HRRR MODEL SHOWS CONVECTIVE SHOWERS BREAKING OUT FURTHER WEST INTO PARTS OF JACKSON COUNTY LATE THIS AFTERNOON AND HAVE EXPANDED THE MENTION OF ISOLATED THUNDER. THE FLOW AT 700 MB WILL BE FROM THE SOUTHWEST, SO SHOWERS AND ISOLATED STORMS THAT DEVELOP WILL MOVE NORTHEAST. IN ADDITION SHOWERS AND ISOLATED STORMS THAT DEVELOP ALONG THE CASCADES WILL TEND TO MOVE NORTHEAST INTO NORTHERN KLAMATH COUNTY AND HAVE EXPANDED THE COVERAGE TO INCLUDE THIS AREA. KEEP IN MIND, MOST HOURS AND LOCATIONS WILL HAVE CONVECTIVE SHOWERS, BUT CONDITIONS ARE FAVORABLE FOR ISOLATED THUNDERSTORMS LATE THIS AFTERNOON AND EVENING. -PETRUCELLI && .AVIATION...IFR AND MVFR CIGS WILL GRADUALLY LIFT TO VFR LATE THIS MORNING AND WILL CONTINUE INTO THIS AFTERNOON. THE MAIN CONCERN WILL BE THE POTENTIAL FOR ISOLATED THUNDERSTORMS FROM ABOUT THE SCOTT VALLEY, SISKIYOUS, AND CASCADES THIS AFTERNOON, SPREADING NORTHEASTWARD ACROSS THE EAST SIDE DURING THE EVENING. THESE STORMS WILL BE CAPABLE OF GUSTY OUTFLOW WINDS, ESPECIALLY THIS AFTERNOON, AS WELL AS BRIEF MVFR TO IFR DOWNPOURS AND SMALL HAIL. AREAS AROUND KMFR COULD BE AFFECTED BY THUNDERSTORMS BETWEEN 00Z AND 03Z. THIS EVENING AND OVERNIGHT MVFR AND SHOWERS ARE EXPECTED ACROSS THE INTERIOR WEST SIDE. -PETRUCELLI && .MARINE...UPDATED 230 AM PDT SUNDAY, MAY 10, 2015...A MOSTLY DRY COLD FRONT MOVING THROUGH THIS AFTERNOON WILL CAUSE NORTH WINDS TO INCREASE THROUGH EARLY MONDAY. THESE INCREASING NORTH WINDS WILL RESULT IN SMALL CRAFT ADVISORY CONDITIONS FOR MUCH OF THE AREA SOUTH AND WEST OF CAPE BLANCO TONIGHT THROUGH MONDAY NIGHT...PRIMARILY FOR STEEP SEAS. SHOWERS ARE EXPECTED LATE MONDAY NIGHT THROUGH WEDNESDAY. WINDS AND SEAS WILL DIMINISH ON TUESDAY AND ARE LIKELY REMAIN BELOW ADVISORY LEVELS THROUGH THURSDAY. && .PREV DISCUSSION... /ISSUED 640 AM PDT SUN MAY 10 2015/ DISCUSSION...A COLD FRONT IS ON TRACK TO MOVE ASHORE THIS MORNING AND CROSSES THE CASCADES INTO THE KLAMATH BASIN BY EARLY THIS AFTERNOON. HIGHS TODAY WILL BE ABOUT 5 DEGREES COOLER WEST OF THE CASCADES...WHILE TEMPERATURES EAST OF THE CASCADES ARE NOT EXPECTED TO BE MUCH DIFFERENT THAN YESTERDAY. MODELS SUGGEST ENOUGH INSTABILITY EXIST TO WARRANT A SLIGHT CHANCE OF THUNDERSTORMS ALONG THE CASCADES AND FROM ABOUT THE SCOTT VALLEY TO THE TRINITY ALPS AND SISKIYOUS IN NORTHERN CAL. PRECIPITABLE WATER WILL ALSO BE INCREASING AND COMING UP FROM THE SACRAMENTO VALLEY INTO THE SHASTA VALLEY. IT`S POSSIBLE THAT ANY STORM THAT DEVELOP WILL PRODUCE RAINFALL. THE AREA OF INSTABILITY WILL CONTINUE TO SHIFT EAST THIS EVENING WITH THUNDERSTORM POTENTIAL EXPANDING INTO THE WARNER MOUNTAINS. THE UPPER LEVEL TROUGH WILL DIG SOUTH WITH THE CLOSED LOW COMING INLAND NEAR REEDSPORT MONDAY AFTERNOON. THE LOW PRESSURE IS EXPECTED TO MOVE OVER THE SOUTHERN OREGON MONDAY NIGHT INTO TUESDAY PER THE GFS SOLUTION, WITH THE ECMWF KEEPING THE LOW OVER THE GOOSE LAKE AREA. IN BOTH SOLUTIONS THERE IS PLENTY OF COLD AIR ALOFT THAT WILL HELP TO DESTABILIZE THE ATMOSPHERE. THIS IN COMBINATION WITH DAYTIME HEATING WILL RESULT IN MORE WIDESPREAD SHOWERS. THE MODELS SHOW THE GREATEST INSTABILITY ALONG AND EAST OF THE CASCADES WITH DIVERGENCE ALOFT, SO HAVE MODERATE CONFIDENCE FOR THUNDERSTORMS IN THIS AREA, ESPECIALLY GIVEN THAT 500MB TEMPERATURES WILL BE BETWEEN -25 AND -28C. SHOWERS WILL OCCUR JUST ABOUT ANYWHERE TUESDAY WITH SOME MODERATE TO HEAVY IN THE AFTERNOON AS WE REACH MAX HEATING. SNOW LEVELS TUESDAY ARE EXPECTED TO BE AROUND 5000 FEET, BUT WILL TEMPORARILY LOWER IN HEAVIER SHOWERS. RIGHT NOW, WERE ONLY EXPECTING SNOW TO ACCUMULATE OVER THE HIGHER TERRAIN ALONG AND EAST OF THE CASCADES. MEANWHILE THERE`S STILL A CHANCE FOR THUNDERSTORMS ALONG AND EAST OF THE CASCADES. SHOWERS WILL GRADUALLY DECREASE TUESDAY NIGHT AS THE UPPER LOW MOVES AWAY AS WE LOSE DAYTIME HEATING. /FB FIRE WEATHER...UPDATED 600 AM PDT SUNDAY, MAY 10, 2015...A COLD FRONT WILL DEVELOP OVER THE AREA TODAY GIVING RISE TO SHOWERS AND ISOLATED THUNDERSTORMS FROM ABOUT THE SCOTT VALLEY, SISKIYOUS, AND CASCADES EASTWARD. THE BEST POSSIBILITY FOR THUNDERSTORMS TODAY APPEARS TO BE FROM ABOUT THE NORTHEASTERN TRINITY ALPS AND THE EASTERN SCOTT AND SHASTA VALLEYS NORTH-NORTHEASTWARD INTO AREAS OF KLAMATH COUNTY FROM THE CASCADE CREST EASTWARD. MID-LEVEL SOUTHWEST FLOW WITH NORTHWEST FLOW IN THE LOWER LEVELS WILL CAUSE WINDS AND MOISTURE TO CONVERGE IN THESE AREAS, WHERE PRECIPITABLE WATER VALUES OF 0.50" TO 0.75" ARE EXPECTED AND MODEL LIFTED INDICES AREA MOSTLY IN THE -2C TO -4C RANGE. THIS MEANS STORMS SHOULD GENERALLY PRODUCE RAINFALL, THOUGH AMOUNTS ARE LIKELY TO BE LIGHT TO MODERATE AT 0.10" TO 0.25" OR LESS. STORMS ARE EXPECTED TO MOVE FROM SOUTHWEST TO NORTHEAST AT 15-20 KNOTS. THE STORMS WILL CAPABLE OF GUSTY OUTFLOW WINDS OF 25 TO 35 MPH AND SMALL HAIL. GUSTY SOUTHWEST WINDS ARE EXPECTED AHEAD OF THE FRONT OVER THE EAST SIDE THIS AFTERNOON, WITH GUSTY NORTHWEST WINDS BEHIND IT ON THE WEST SIDE. SCATTERED SHOWERS ACROSS THE AREA TONIGHT WILL INCREASE IN COVERAGE AND INTENSITY MONDAY AFTERNOON AND EVENING UNDER A GENERAL WEST FLOW. ISOLATED THUNDERSTORMS ARE EXPECTED ON THE EAST SIDE MONDAY AFTERNOON AND EVENING, PRIMARILY EAST OF THE CASCADES. SHOWERS AND THUNDERSTORMS ARE LIKELY OVER MUCH OF THE AREA ON TUESDAY AS THE UPPER LEVEL LOW MOVES OVERHEAD. BTL && .MFR WATCHES/WARNINGS/ADVISORIES... OR...NONE. CA...NONE. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING TO 11 PM PDT MONDAY FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FOR WINDS FROM 2 AM TO 11 PM PDT MONDAY FOR PZZ376. $$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
306 AM EDT SUN MAY 10 2015 .SYNOPSIS... AN ANOMALOUS UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST CONUS THROUGH MONDAY. SUMMER LIKE WEATHER WILL BE ENJOYED BY MOST...EXCEPT FOR A MOIST MARITIME FLOW BRINGING PERIODS OF LOW CLOUDS AND FOG TO PORTIONS OF THE LOWER TO MIDDLE SUSQUEHANNA RIVER VALLEY THROUGH SUNDAY. A SHARP COLD FRONT WILL CROSS THE AREA EARLY TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM BUILDING SOUTHEAST INTO PA THE LATER HALF OF NEXT WEEK. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... SCT RING OF FIRE CONVECTION CONTINUES TO FIRE WITHIN PLUME OF ANOMALOUS PWATS ON NW PERIPHERY OF UPPER RIDGE FROM THE MISS VALLEY INTO NW PA. EXPECT SHOWERS TO DWINDLE OVR WARREN CO EARLY THIS MORNING...AS BLYR COOLS/STABILIZES. LATEST HRRR SUPPORTS THIS IDEA WITH SHOWERS TAPERING OFF BTWN 06Z-09Z. ACROSS THE SE HALF OF THE STATE...FOCUS WILL BE ON MARINE STRATUS ADVECTING WESTWARD INTO THE AREA TOWARD DAWN. LATEST SREF AND HRRR OUTPUT SUPPORT THE STRATUS REACHING TO ABOUT THE SUSQ RIVER. UNCERTAIN IF STRATUS WILL REACH FURTHER WEST INTO THE RIDGE/VALLEY REGION...BUT IF IT DOESN/T PATCHY RADIATION FOG APPEARS LIKELY FROM KAOO THRU KUNV AND KIPT. HAVE REMOVED MENTION OF DZ ACROSS THE EASTERN COUNTIES...WHERE MDL SOUNDINGS INDICATE DEPTH OF MOISTURE WILL REMAIN TOO SHALLOW TO SUPPORT ANY PRECIP. TEMPS ON TRACK TO BOTTOM OUT THIS MORNING IN THE L60S MOST SPOTS. && .SHORT TERM /7 AM THIS MORNING THROUGH 6 PM MONDAY/... AM LOW CLOUDS/FOG SHOULD ONCE AGAIN MIX OUT BY LATE AM...WITH AREAS EAST OF KMDT SEEING THE MOST PERSISTENT CLOUD COVER. ENS MEAN 8H TEMPS SUPPORTIVE OF MAX TEMPS IN THE LOW TO MID 80S. WARM MID LVL TEMPS ARE LIKELY TO ONCE AGAIN SUPPRESS CONVECTION OVER MOST OF CENTRAL/SOUTHERN PA. HOWEVER...GEFS/SREF OUTPUT SUPPORTS A DECENT CHANCE OF PM TSRA ACROSS THE NW MTNS ON NORTHERN PERIPHERY OF UPPER RIDGE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... DID NOT CHANGE MUCH FOR SUNDAY NIGHT INTO TUE. HARD TO SEE MUCH GOING ON BEFORE MONDAY NIGHT...WHEN THE COLD FRONT MOVES INTO THE AREA. DID UP TEMPS A LITTLE HERE AND THERE. DID CUT BACK ON POPS SOME. WEAK UPPER LEVEL SYSTEM LIFTING NE SUNDAY NIGHT COULD TOUCH OFF A SHOWER OR STORM. LACK OF SFC COVERGENCE...HEIGHT FALLS...AND TIMING OF THE COLD FRONT FOR TUE...HARD TO SEE A LOT OF WIDESPREAD SEVERE STORMS. STILL HAVE TO WATCH ANY MOISTURE WORKING INTO SE PA FROM TS ANA. RATHER STRONG MID LEVEL WIND FIELDS FOR WED. IT WILL BE BREEZY AND COOL...WITH SOME CLDS AND PERHAPS A SHOWER TO THE NORTH. MORE DETAIL BELOW. THE FLOW ALOFT WILL TRANSITION TO A TROUGHING PATTERN BY WED. CHILLY TEMPS ALOFT WILL LIKELY LEAD TO PLENTY OF STRATOCU/CU ACROSS THE AREA WED...WITH A SHRA EVEN POSSIBLE ACROSS THE N MTNS W/PASSAGE OF UPPER TROF AXIS. LOOK FOR TEMPERATURES TO DROP TO NEAR/BELOW NORMAL WED-THU WITH A COUPLE OF VERY CHILLY MORNINGS THU/FRI...AS SFC HIGH BUILDS OVR THE AREA. MAY HAVE TO CONTEND W/POSSIBLE FROST OVR THE NW MTNS THOSE MORNINGS WITH MINS LKLY IN THE 30S. GROWING SEASON STARTS MAY 11 OVER PARTS OF THE ALLEGHENY MTNS. CONFIDENCE IN NEAR-FREEZING TEMPS IS HIGHEST IN MCKEAN/POTTER AND ELK BUT THE GROWING SEASON DOES NOT BEGIN IN THESE COUNTIES UNTIL MAY 21. WENT WITH A DRY FCST FOR THU INTO SAT...AS THE UPPER LVL RIDGE STARTS TO BUILD ACROSS THE EAST AGAIN. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... EARLY THIS OVERNIGHT IN THE NW MTNS...A CLUSTER OF SHOWERS/TSTMS WILL SLIP BETWEEN KERI-KBFD...IMPACTING KJHW BUT MISSING KBFD. BY 09Z...THIS AREA OF SHOWERS WILL BE QUICKLY DIMINISHING. MARINE STRATUS/FOG WILL AGAIN WORK IN FROM THE SE. IFR CONDITIONS HAVE ALREADY REACHED KLNS...AND WILL CONTINUE TO EDGE FURTHER NORTH/WEST TOWARD THE CENTRAL MTNS MAINLY AFTER 08Z. OVERALL EXTEND WILL LIKELY BE LARGER THAN LAST NIGHT...POSSIBLY ALL THE WAY TO KAOO-KUNV-KIPT. THESE REDUCTIONS WILL CLEAR BY MID/LATE MORNING WITH KMDT-KLNS HOLDING ON TO RESTRICTIONS THE LONGEST. UPPER RIDGE REMAINS OVER THE REGION SUNDAY. WITH LOW LEVEL MOISTURE INCREASING...POSS OF CONVECTION WILL BE A BIT HIGHER THAN SAT. BEST CHANCES WILL BE IN THE NW MTNS...WITH LOW PROBS IN THE LAURELS AND SE. OVERALL PROBS TOO LOW TO MENTION IN TAFS OUTSIDE OF KBFD. OUTLOOK... MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE. TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS. WED-THU...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DEVOIR/FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...DEVOIR/FITZGERALD LONG TERM...FITZGERALD/GARTNER/MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
156 AM EDT SUN MAY 10 2015 .SYNOPSIS... AN ANOMALOUS UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST CONUS THROUGH MONDAY. SUMMER LIKE WEATHER WILL BE ENJOYED BY MOST...EXCEPT FOR A MOIST MARITIME FLOW BRINGING PERIODS OF LOW CLOUDS AND FOG TO PORTIONS OF THE LOWER TO MIDDLE SUSQUEHANNA RIVER VALLEY THROUGH SUNDAY. A SHARP COLD FRONT WILL CROSS THE AREA EARLY TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM BUILDING SOUTHEAST INTO PA THE LATER HALF OF NEXT WEEK. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... SCT RING OF FIRE CONVECTION CONTINUES TO FIRE WITHIN PLUME OF ANOMALOUS PWATS ON NW PERIPHERY OF UPPER RIDGE FROM THE MISS VALLEY INTO NW PA. EXPECT SHOWERS TO DWINDLE OVR WARREN CO EARLY THIS MORNING...AS BLYR COOLS/STABILIZES. LATEST HRRR SUPPORTS THIS IDEA WITH SHOWERS TAPERING OFF BTWN 06Z-09Z. ACROSS THE SE HALF OF THE STATE...FOCUS WILL BE ON MARINE STRATUS ADVECTING WESTWARD INTO THE AREA TOWARD DAWN. LATEST SREF AND HRRR OUTPUT SUPPORT THE STRATUS REACHING TO ABOUT THE SUSQ RIVER. UNCERTAIN IF STRATUS WILL REACH FURTHER WEST INTO THE RIDGE/VALLEY REGION...BUT IF IT DOESN/T PATCHY RADIATION FOG APPEARS LIKELY FROM KAOO THRU KUNV AND KIPT. HAVE REMOVED MENTION OF DZ ACROSS THE EASTERN COUNTIES...WHERE MDL SOUNDINGS INDICATE DEPTH OF MOISTURE WILL REMAIN TOO SHALLOW TO SUPPORT ANY PRECIP. TEMPS ON TRACK TO BOTTOM OUT THIS MORNING IN THE L60S MOST SPOTS. && .SHORT TERM /7 AM THIS MORNING THROUGH 6 PM MONDAY/... AM LOW CLOUDS/FOG SHOULD ONCE AGAIN MIX OUT BY LATE AM...WITH AREAS EAST OF KMDT SEEING THE MOST PERSISTENT CLOUD COVER. ENS MEAN 8H TEMPS SUPPORTIVE OF MAX TEMPS IN THE LOW TO MID 80S. WARM MID LVL TEMPS ARE LIKELY TO ONCE AGAIN SUPPRESS CONVECTION OVER MOST OF CENTRAL/SOUTHERN PA. HOWEVER...GEFS/SREF OUTPUT SUPPORTS A DECENT CHANCE OF PM TSRA ACROSS THE NW MTNS ON NORTHERN PERIPHERY OF UPPER RIDGE. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... RESENT TO ADD SATURDAY TO HEADER ON LINE ABOVE. DID NOT CHANGE MUCH FOR SUNDAY NIGHT INTO TUE. HARD TO SEE MUCH GOING ON BEFORE MONDAY NIGHT...WHEN THE COLD FRONT MOVES INTO THE AREA. DID UP TEMPS A LITTLE HERE AND THERE. DID CUT BACK ON POPS SOME. WEAK UPPER LEVEL SYSTEM LIFTING NE SUNDAY NIGHT COULD TOUCH OFF A SHOWER OR STORM. LACK OF SFC COVERGENCE...HEIGHT FALLS...AND TIMING OF THE COLD FRONT FOR TUE...HARD TO SEE A LOT OF WIDESPREAD SEVERE STORMS. STILL HAVE TO WATCH ANY MOISTURE WORKING INTO SE PA FROM TS ANA. RATHER STRONG MID LEVEL WIND FIELDS FOR WED. IT WILL BE BREEZY AND COOL...WITH SOME CLDS AND PERHAPS A SHOWER TO THE NORTH. MORE DETAIL BELOW. THE FLOW ALOFT WILL TRANSITION TO A TROUGHING PATTERN BY WED. CHILLY TEMPS ALOFT WILL LIKELY LEAD TO PLENTY OF STRATOCU/CU ACROSS THE AREA WED...WITH A SHRA EVEN POSSIBLE ACROSS THE N MTNS W/PASSAGE OF UPPER TROF AXIS. LOOK FOR TEMPERATURES TO DROP TO NEAR/BELOW NORMAL WED-THU WITH A COUPLE OF VERY CHILLY MORNINGS THU/FRI...AS SFC HIGH BUILDS OVR THE AREA. MAY HAVE TO CONTEND W/POSSIBLE FROST OVR THE NW MTNS THOSE MORNINGS WITH MINS LKLY IN THE 30S. GROWING SEASON STARTS MAY 11 OVER PARTS OF THE ALLEGHENY MTNS. CONFIDENCE IN NEAR-FREEZING TEMPS IS HIGHEST IN MCKEAN/POTTER AND ELK BUT THE GROWING SEASON DOES NOT BEGIN IN THESE COUNTIES UNTIL MAY 21. WENT WITH A DRY FCST FOR THU INTO SAT...AS THE UPPER LVL RIDGE STARTS TO BUILD ACROSS THE EAST AGAIN. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS WILL CONTINUE THROUGH THE FIRST HALF OF TONIGHT. STREAMING MOISTURE ALONG A BOUNDARY IS SLOWLY PROGRESSING INTO THE NW MTNS. THIS WILL BRING SHOWERS AND POSSIBLE MVFR CIGS AND FOR A SHORT TIME...IFR IS POSSIBLE...TO BFD. TONIGHT WE LIKELY SEE A REPEAT PERFORMANCE OF THE MARINE STRATUS/FOG WORKING INTO THE SE COUNTIES - MAINLY AFTER 08Z. LATEST MDL SOUNDINGS/SREF OUTPUT SUGGESTS THE THREAT OF LOW CLOUDS/FOG WILL EXTEND FURTHER NW THAN THIS AM...POSSIBLY ALL THE WAY TO KAOO- KUNV-KIPT. HAVE INCLUDED UNV...BUT HELD OFF ON IPT AND AOO THOUGH MVFR CIGS REMAIN POSSIBLE. ALL REDUCING CIGS AND VSBYS WILL CLEAR BY LATE MORNING WITH MDT AND LNS BEING HOLDING ONTO RESTRICTIONS THE LONGEST. OUTLOOK... SUN...AM LOW CLOUDS/FOG POSSIBLE MAINLY SE. ISOLD PM TSRA IMPACTS POSS W MTNS. MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE. TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS. WED-THU...VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DEVOIR/FITZGERALD NEAR TERM...FITZGERALD SHORT TERM...DEVOIR/FITZGERALD LONG TERM...FITZGERALD/GARTNER/MARTIN AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1246 PM CDT SUN MAY 10 2015 .UPDATE... ISSUED AT 1235 PM CDT SUN MAY 10 2015 ADJUSTMENTS TO POPS/TSTM COVERAGE WERE MADE TO ACCOUNT FOR CURRENT STORMS MOVING NORTH OVER WESTERN PART OF AREA AND EXPECTED BIG INCREASE SHORTLY FURTHER EAST...OF COURSE CURRENT TORNADO WATCH IS GOOD. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 412 AM CDT SUN MAY 10 2015 SURFACE ANALYSIS VERY EARLY THIS MORNING SHOWING THE SURFACE LOW BEGINNING TO PUSH INTO SOUTHERN NEBRASKA...ON TRACK TO LIFT INTO OUR AREA BY MID DAY. PRESENT RADAR SHOWING BAND OF SHOWERS AND THUNDERSTORMS ASSOCIATED WITH MIDLEVEL WARM AIR ADVECTION/ISENTROPIC LIFT TRACKING NORTHWARD INTO THE MO RIVER CORRIDOR. EXPECT THIS TO CONTINUE TO SPREAD NORTHWARD THROUGH THE MORNING...THEN WILL MOST LIKELY GET A BREAK IN THE ACTIVITY AS A DRY SLOT BEGINS TO WORK INTO THE AREA BY MID TO LATE MORNING. MODELS ARE ALL IN DECENT AGREEMENT ON TAKING THE AFOREMENTIONED SURFACE LOW UP THROUGH THE JAMES RIVER VALLEY DURING THE AFTERNOON...WITH THE EXCEPTION BEING THE GFS WHICH TRACKS THE LOW MUCH FARTHER TO THE EAST...SO DISCARDED THAT SOLUTION. USING THE MODEL CONSENSUS LOW PRESSURE POSITION WOULD PUT THE WARM FRONT SOMEWHERE IN THE VICINITY OF A MITCHELL SD TO SPENCER LINE BY 21Z. TO THE SOUTH OF THIS...AFTERNOON TEMPERATURES LOOK TO CLIMB WELL INTO THE 70S...WITH MUCAPE VALUES REACHING INTO THE 1200 TO 1500 J/KG RANGE SOUTH OF THE WARM FRONT BY LATE AFTERNOON. THE 0 TO 6 KM BULK SHEAR LOOKS TO BE INCREDIBLE BY AFTERNOON...WITH THE RAP PROGGING VALUES OF 50 TO 60 KTS IN THE VICINITY OF THE BOUNDARY. BOTH THE RAP AND HRRR INDICATE DISCRETE THUNDERSTORM DEVELOPMENT THROUGH THE LOWER MO RIVER VALLEY/NORTHWESTERN IOWA SOMETIME IN THE 19Z TO 20Z WINDOW...THEN TRANSITIONING TO MORE MULTICELLULAR THROUGH THE LATER AFTERNOON AND EVENING AS THE WHOLE COMPLEX LIFTS TO THE NORTH AND EAST. BASED ON THE ABOVE MENTIONED CONVECTIVE PARAMETERS IT SEEMS THAT A FEW SEVERE STORMS ARE PRETTY LIKELY WITH LARGE HAIL AND DAMAGING WINDS. IN ADDITION...RAP 0 TO 1 KM HELICITY VALUES ARE RUNNING ROUGHLY AROUND 160 UNITS ALONG THE WARM FRONT...WITH 0 TO 1 EHI AROUND 1...SO CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED TORNADO THREAT NEAR THE BOUNDARY BETWEEN 20Z AND 00Z. SHOWERS AND THUNDERSTORMS WILL LIFT OFF TO THE NORTH AND EAST THROUGH THE MID AND LATE EVENING AS THE LOW AND ASSOCIATED FRONTAL BOUNDARY TRACK EASTWARD...WITH THE SEVERE THREAT WANING FAIRLY QUICKLY IN THE EVENING AS THE INSTABILITY WEAKENS. COOLER AIR WILL BEGIN TO FILTER IN BEHIND THE SYSTEM WITH OVERNIGHT LOWS IN THE UPPER 30S TO MID 40S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 412 AM CDT SUN MAY 10 2015 SCATTERED SHOWERS WILL LINGER INTO MONDAY AS ANOTHER LOBE OF ENERGY ROTATES AROUND SLOWLY DEPARTING UPPER LOW. WILL BE A BLUSTERY AND COOL DAY WITH NORTHWEST WINDS 20 TO 35 MPH AND TEMPERATURES LARGELY STUCK IN THE 40S. SHOWERS WILL DECREASE SOUTHWEST TO NORTHEAST AS THE UPPER LOW PULLS AWAY MONDAY NIGHT...WITH CLEARING EXPECTED OVER ALL BUT THE FAR NORTHEAST BY DAYBREAK TUESDAY. COOL AIR MASS WILL ALLOW TEMPERATURES TO FALL INTO THE MID-UPPER 30S...BUT WINDS SHOULD REMAIN UP ENOUGH TO PRECLUDE ANY FROST DEVELOPMENT. SURFACE RIDGE MOVES ACROSS THE AREA TUESDAY/TUESDAY EVENING...WITH MOSTLY SUNNY SKIES HELPING TEMPERATURES RISE INTO THE MID 50S TO LOWER 60S. LONGER RANGE PORTION OF THE FORECAST WEDNESDAY THROUGH SATURDAY BEGINS WITH UPPER RIDGE SHIFTING EAST INTO THE MISSISSIPPI VALLEY WHILE BROAD TROUGH DEEPENS OFF THE WEST COAST. WHILE LONGER RANGE MODELS GENERALLY AGREE ON LARGE SCALE PATTERN SHOWING DEEP TROUGH SLOWLY WORKING INTO THE ROCKIES WHILE UPPER RIDGE DOMINATES ACROSS THE SOUTHEASTERN CONUS...SEEING QUITE A BIT OF DISPARITY AMONG THE MODELS IN HANDLING OF VARIOUS SHORTWAVES EJECTING OUT OF THE WESTERN TROUGH INTO THE NORTHERN/CENTRAL PLAINS. RESULT IS LOWER CONFIDENCE PRECIPITATION FORECAST FOR LATE NEXT WEEK...AND HAVE STRAYED LITTLE FROM BROAD MODEL CONSENSUS WHICH CURRENTLY FOCUS HIGHER CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN TOWARD THE START OF THE WEEKEND. A LITTLE BETTER AGREEMENT SHOWING GRADUAL WARMING TREND... WITH DAYTIME HIGHS CLIMBING BACK INTO THE 70S BY LATE IN THE WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1235 PM CDT SUN MAY 10 2015 GENERALLY IFR CEILINGS AND AREAS OF VISIBILITY 3-5SM SHRA/TSRA FAR WESTERN PART OF THE FORECAST AREA INCLUDING KHON...AFT 11/00Z THIS AREA WILL SEE CEILINGS 1-2K FEET VARIABLE TO BELOW 1K FEET WITH SCATTERED -SHRA. OVER CENTRAL AND EASTERN PART OF THE AREA CEILINGS 1-3K FEET WITH SOME CEILINGS BELOW 1K FEET ESPECIALLY NORTH OF KFSD. AREAS OF VISIBILITY 3-5SM IN SHRA/TSRA...THEN AFTER 11/03Z CEILINGS 1-2K FEET VARIABLE TO BELOW 1K FEET...SCT -SHRA MAINLY NORTH OF FSD. SURFACE GUSTS ABOVE 25 KNOTS FROM THE SOUTHEAST OVER SOUTHEAST PART OF THE AREA...OTHERWISE SURFACE GUSTS ABOVE 25 KNOTS FROM THE W/NW DEVELOPING FROM THE WEST AFTER 11/12Z. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE... SHORT TERM...JM LONG TERM...JH AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
629 AM CDT SUN MAY 10 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 412 AM CDT SUN MAY 10 2015 SURFACE ANALYSIS VERY EARLY THIS MORNING SHOWING THE SURFACE LOW BEGINNING TO PUSH INTO SOUTHERN NEBRASKA...ON TRACK TO LIFT INTO OUR AREA BY MID DAY. PRESENT RADAR SHOWING BAND OF SHOWERS AND THUNDERSTORMS ASSOCIATED WITH MIDLEVEL WARM AIR ADVECTION/ISENTROPIC LIFT TRACKING NORTHWARD INTO THE MO RIVER CORRIDOR. EXPECT THIS TO CONTINUE TO SPREAD NORTHWARD THROUGH THE MORNING...THEN WILL MOST LIKELY GET A BREAK IN THE ACTIVITY AS A DRY SLOT BEGINS TO WORK INTO THE AREA BY MID TO LATE MORNING. MODELS ARE ALL IN DECENT AGREEMENT ON TAKING THE AFOREMENTIONED SURFACE LOW UP THROUGH THE JAMES RIVER VALLEY DURING THE AFTERNOON...WITH THE EXCEPTION BEING THE GFS WHICH TRACKS THE LOW MUCH FARTHER TO THE EAST...SO DISCARDED THAT SOLUTION. USING THE MODEL CONSENSUS LOW PRESSURE POSITION WOULD PUT THE WARM FRONT SOMEWHERE IN THE VICINITY OF A MITCHELL SD TO SPENCER LINE BY 21Z. TO THE SOUTH OF THIS...AFTERNOON TEMPERATURES LOOK TO CLIMB WELL INTO THE 70S...WITH MUCAPE VALUES REACHING INTO THE 1200 TO 1500 J/KG RANGE SOUTH OF THE WARM FRONT BY LATE AFTERNOON. THE 0 TO 6 KM BULK SHEAR LOOKS TO BE INCREDIBLE BY AFTERNOON...WITH THE RAP PROGGING VALUES OF 50 TO 60 KTS IN THE VICINITY OF THE BOUNDARY. BOTH THE RAP AND HRRR INDICATE DISCRETE THUNDERSTORM DEVELOPMENT THROUGH THE LOWER MO RIVER VALLEY/NORTHWESTERN IOWA SOMETIME IN THE 19Z TO 20Z WINDOW...THEN TRANSITIONING TO MORE MULTICELLULAR THROUGH THE LATER AFTERNOON AND EVENING AS THE WHOLE COMPLEX LIFTS TO THE NORTH AND EAST. BASED ON THE ABOVE MENTIONED CONVECTIVE PARAMETERS IT SEEMS THAT A FEW SEVERE STORMS ARE PRETTY LIKELY WITH LARGE HAIL AND DAMAGING WINDS. IN ADDITION...RAP 0 TO 1 KM HELICITY VALUES ARE RUNNING ROUGHLY AROUND 160 UNITS ALONG THE WARM FRONT...WITH 0 TO 1 EHI AROUND 1...SO CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED TORNADO THREAT NEAR THE BOUNDARY BETWEEN 20Z AND 00Z. SHOWERS AND THUNDERSTORMS WILL LIFT OFF TO THE NORTH AND EAST THROUGH THE MID AND LATE EVENING AS THE LOW AND ASSOCIATED FRONTAL BOUNDARY TRACK EASTWARD...WITH THE SEVERE THREAT WANING FAIRLY QUICKLY IN THE EVENING AS THE INSTABILITY WEAKENS. COOLER AIR WILL BEGIN TO FILTER IN BEHIND THE SYSTEM WITH OVERNIGHT LOWS IN THE UPPER 30S TO MID 40S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 412 AM CDT SUN MAY 10 2015 SCATTERED SHOWERS WILL LINGER INTO MONDAY AS ANOTHER LOBE OF ENERGY ROTATES AROUND SLOWLY DEPARTING UPPER LOW. WILL BE A BLUSTERY AND COOL DAY WITH NORTHWEST WINDS 20 TO 35 MPH AND TEMPERATURES LARGELY STUCK IN THE 40S. SHOWERS WILL DECREASE SOUTHWEST TO NORTHEAST AS THE UPPER LOW PULLS AWAY MONDAY NIGHT...WITH CLEARING EXPECTED OVER ALL BUT THE FAR NORTHEAST BY DAYBREAK TUESDAY. COOL AIR MASS WILL ALLOW TEMPERATURES TO FALL INTO THE MID-UPPER 30S...BUT WINDS SHOULD REMAIN UP ENOUGH TO PRECLUDE ANY FROST DEVELOPMENT. SURFACE RIDGE MOVES ACROSS THE AREA TUESDAY/TUESDAY EVENING...WITH MOSTLY SUNNY SKIES HELPING TEMPERATURES RISE INTO THE MID 50S TO LOWER 60S. LONGER RANGE PORTION OF THE FORECAST WEDNESDAY THROUGH SATURDAY BEGINS WITH UPPER RIDGE SHIFTING EAST INTO THE MISSISSIPPI VALLEY WHILE BROAD TROUGH DEEPENS OFF THE WEST COAST. WHILE LONGER RANGE MODELS GENERALLY AGREE ON LARGE SCALE PATTERN SHOWING DEEP TROUGH SLOWLY WORKING INTO THE ROCKIES WHILE UPPER RIDGE DOMINATES ACROSS THE SOUTHEASTERN CONUS...SEEING QUITE A BIT OF DISPARITY AMONG THE MODELS IN HANDLING OF VARIOUS SHORTWAVES EJECTING OUT OF THE WESTERN TROUGH INTO THE NORTHERN/CENTRAL PLAINS. RESULT IS LOWER CONFIDENCE PRECIPITATION FORECAST FOR LATE NEXT WEEK...AND HAVE STRAYED LITTLE FROM BROAD MODEL CONSENSUS WHICH CURRENTLY FOCUS HIGHER CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN TOWARD THE START OF THE WEEKEND. A LITTLE BETTER AGREEMENT SHOWING GRADUAL WARMING TREND... WITH DAYTIME HIGHS CLIMBING BACK INTO THE 70S BY LATE IN THE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 623 AM CDT SUN MAY 10 2015 SHOWERS AND THUNDERSTORMS WILL CONTINUE TO LIFT THROUGH THE AREA DURING THE MORNING...THEN THE ACTIVITY WILL LESSEN INTO THE AFTERNOON. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP AFTER 20Z TODAY...AND SOME OF THESE MAY BE SEVERE THROUGH FAR SOUTHEASTERN SOUTH DAKOTA...NORTHWESTERN IOWA...AND NORTHEASTERN NEBRASKA THROUGH 00Z. MVFR TO SOME IFR CEILINGS WILL BE COMMON THROUGH THE TAF PERIOD. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...JM LONG TERM...JH AVIATION...JM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
412 AM CDT SUN MAY 10 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 412 AM CDT SUN MAY 10 2015 SURFACE ANALYSIS VERY EARLY THIS MORNING SHOWING THE SURFACE LOW BEGINNING TO PUSH INTO SOUTHERN NEBRASKA...ON TRACK TO LIFT INTO OUR AREA BY MID DAY. PRESENT RADAR SHOWING BAND OF SHOWERS AND THUNDERSTORMS ASSOCIATED WITH MIDLEVEL WARM AIR ADVECTION/ISENTROPIC LIFT TRACKING NORTHWARD INTO THE MO RIVER CORRIDOR. EXPECT THIS TO CONTINUE TO SPREAD NORTHWARD THROUGH THE MORNING...THEN WILL MOST LIKELY GET A BREAK IN THE ACTIVITY AS A DRY SLOT BEGINS TO WORK INTO THE AREA BY MID TO LATE MORNING. MODELS ARE ALL IN DECENT AGREEMENT ON TAKING THE AFOREMENTIONED SURFACE LOW UP THROUGH THE JAMES RIVER VALLEY DURING THE AFTERNOON...WITH THE EXCEPTION BEING THE GFS WHICH TRACKS THE LOW MUCH FARTHER TO THE EAST...SO DISCARDED THAT SOLUTION. USING THE MODEL CONSENSUS LOW PRESSURE POSITION WOULD PUT THE WARM FRONT SOMEWHERE IN THE VICINITY OF A MITCHELL SD TO SPENCER LINE BY 21Z. TO THE SOUTH OF THIS...AFTERNOON TEMPERATURES LOOK TO CLIMB WELL INTO THE 70S...WITH MUCAPE VALUES REACHING INTO THE 1200 TO 1500 J/KG RANGE SOUTH OF THE WARM FRONT BY LATE AFTERNOON. THE 0 TO 6 KM BULK SHEAR LOOKS TO BE INCREDIBLE BY AFTERNOON...WITH THE RAP PROGGING VALUES OF 50 TO 60 KTS IN THE VICINITY OF THE BOUNDARY. BOTH THE RAP AND HRRR INDICATE DISCRETE THUNDERSTORM DEVELOPMENT THROUGH THE LOWER MO RIVER VALLEY/NORTHWESTERN IOWA SOMETIME IN THE 19Z TO 20Z WINDOW...THEN TRANSITIONING TO MORE MULTICELLULAR THROUGH THE LATER AFTERNOON AND EVENING AS THE WHOLE COMPLEX LIFTS TO THE NORTH AND EAST. BASED ON THE ABOVE MENTIONED CONVECTIVE PARAMETERS IT SEEMS THAT A FEW SEVERE STORMS ARE PRETTY LIKELY WITH LARGE HAIL AND DAMAGING WINDS. IN ADDITION...RAP 0 TO 1 KM HELICITY VALUES ARE RUNNING ROUGHLY AROUND 160 UNITS ALONG THE WARM FRONT...WITH 0 TO 1 EHI AROUND 1...SO CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED TORNADO THREAT NEAR THE BOUNDARY BETWEEN 20Z AND 00Z. SHOWERS AND THUNDERSTORMS WILL LIFT OFF TO THE NORTH AND EAST THROUGH THE MID AND LATE EVENING AS THE LOW AND ASSOCIATED FRONTAL BOUNDARY TRACK EASTWARD...WITH THE SEVERE THREAT WANING FAIRLY QUICKLY IN THE EVENING AS THE INSTABILITY WEAKENS. COOLER AIR WILL BEGIN TO FILTER IN BEHIND THE SYSTEM WITH OVERNIGHT LOWS IN THE UPPER 30S TO MID 40S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 412 AM CDT SUN MAY 10 2015 SCATTERED SHOWERS WILL LINGER INTO MONDAY AS ANOTHER LOBE OF ENERGY ROTATES AROUND SLOWLY DEPARTING UPPER LOW. WILL BE A BLUSTERY AND COOL DAY WITH NORTHWEST WINDS 20 TO 35 MPH AND TEMPERATURES LARGELY STUCK IN THE 40S. SHOWERS WILL DECREASE SOUTHWEST TO NORTHEAST AS THE UPPER LOW PULLS AWAY MONDAY NIGHT...WITH CLEARING EXPECTED OVER ALL BUT THE FAR NORTHEAST BY DAYBREAK TUESDAY. COOL AIR MASS WILL ALLOW TEMPERATURES TO FALL INTO THE MID-UPPER 30S...BUT WINDS SHOULD REMAIN UP ENOUGH TO PRECLUDE ANY FROST DEVELOPMENT. SURFACE RIDGE MOVES ACROSS THE AREA TUESDAY/TUESDAY EVENING...WITH MOSTLY SUNNY SKIES HELPING TEMPERATURES RISE INTO THE MID 50S TO LOWER 60S. LONGER RANGE PORTION OF THE FORECAST WEDNESDAY THROUGH SATURDAY BEGINS WITH UPPER RIDGE SHIFTING EAST INTO THE MISSISSIPPI VALLEY WHILE BROAD TROUGH DEEPENS OFF THE WEST COAST. WHILE LONGER RANGE MODELS GENERALLY AGREE ON LARGE SCALE PATTERN SHOWING DEEP TROUGH SLOWLY WORKING INTO THE ROCKIES WHILE UPPER RIDGE DOMINATES ACROSS THE SOUTHEASTERN CONUS...SEEING QUITE A BIT OF DISPARITY AMONG THE MODELS IN HANDLING OF VARIOUS SHORTWAVES EJECTING OUT OF THE WESTERN TROUGH INTO THE NORTHERN/CENTRAL PLAINS. RESULT IS LOWER CONFIDENCE PRECIPITATION FORECAST FOR LATE NEXT WEEK...AND HAVE STRAYED LITTLE FROM BROAD MODEL CONSENSUS WHICH CURRENTLY FOCUS HIGHER CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN TOWARD THE START OF THE WEEKEND. A LITTLE BETTER AGREEMENT SHOWING GRADUAL WARMING TREND... WITH DAYTIME HIGHS CLIMBING BACK INTO THE 70S BY LATE IN THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1016 PM CDT SAT MAY 9 2015 CONDITIONS WILL GRADUALLY DIMINISH OVERNIGHT AS A STRONG LOW PRESSURE SHIFTS NORTHWARD. SHOWERS WILL INCREASE IN COVERAGE FROM THE SOUTH AND SOUTHWEST AND A FEW THUNDERSTORMS WILL ALSO BE POSSIBLE FROM ABOUT 9Z THROUGH 14Z. OTHERWISE CEILINGS WILL LOWER TO MVFR AND POSSIBLY IFR AT TIMES AS THE STRONG LOW LEVEL JET AND MOISTURE ALOFT INCREASE. WHILE THERE IS LIKELY TO BE A BIT OF A LULL IN ACTIVITY FROM LATE MORNING INTO THE EARLY AFTERNOON STRONG TO SEVERE THUNDERSTORMS WILL BECOME POSSIBLE OVER FAR SOUTHEAST SOUTH DAKOTA, NORTHEAST NEBRASKA AND NORTHWEST IOWA AFTER ABOUT 21Z. MVFR CEILINGS WILL BE POSSIBLE THROUGH MUCH OF THE PERIOD. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...JM LONG TERM...JH AVIATION...08
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1243 PM CDT SUN MAY 10 2015 .UPDATE...AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 1101 AM CDT SUN MAY 10 2015/ DISCUSSION...LATEST WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES SHOW A MESOSCALE CONVECTIVE SYSTEM MOVING OVER WESTERN ARKANSAS...NORTHEAST OKLAHOMA...AND NORTHEAST TEXAS LATE THIS MORNING. REGIONAL WSR-88D RADAR TRENDS SHOW STORMS EXHIBITING QUASI-LINEAR CHARACTERISTICS OVER WESTERN ARKANSAS. AS OF 10 AM CDT ACROSS THE MID SOUTH...TEMPERATURES ARE IN THE 70S AT MOST LOCATIONS WITH MOSTLY SUNNY SKIES PREVALENT ACROSS MUCH OF THE AREA AS OF THIS MOMENT. LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE MAINLY WEST OF THE MISSISSIPPI RIVER THIS AFTERNOON WHERE BETTER FORCING AND INSTABILITY MAY RESIDE. FURTHER EAST...CONFIDENCE IS MUCH LOWER AND REDUCED RAIN CHANCES NORTH OF I-40 ACROSS WEST TENNESSEE DOWN TO ISOLATED COVERAGE. WILL UPDATE ALL ELEMENTS AS NEEDED TO ACCOUNT FOR THESE TRENDS. UPDATED GRIDS WILL BE AVAILABLE SHORTLY. CJC PREV DISCUSSION... /ISSUED 628 AM CDT SUN MAY 10 2015/ DISCUSSION... UPDATED FOR 12Z AVIATION. PREV DISCUSSION... /ISSUED 416 AM CDT SUN MAY 10 2015/ DISCUSSION... CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER 70S WITH LIGHT SOUTH WINDS. TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY. THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN. TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND 0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL. WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE STORMS IN THE HWO ON MONDAY. OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE 3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY. MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE 70S...LOWS IN THE 50S AND LOWER 60S. THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK. NEAR NORMAL TEMPS. SJM && .AVIATION...18Z TAFS A LINE OF STRONG TO SEVERE THUNDERSTORMS IN WEST ARKANSAS HAS BEEN SLOWING ITS FORWARD PROGRESS AND WEAKENING SLIGHTLY OVER THE LAST SEVERAL HOURS. SHORT TERM GUIDANCE SUGGESTS THIS TREND SHOULD CONTINUE AND THE NORTHERN END OF THE LINE SHOULD BECOME THE FOCUS. THAT SEEMS TO BE ALREADY HAPPENING. AS A RESULT...DO NOT FEEL LIKE IT WILL POSE A THREAT TO ANY OF THE TAF SITES. JBR MAY BE THE EXCEPTION AS STORMS PASS TO THE NORTH...BUT WILL ONLY INCLUDE VCTS FOR NOW. BETTER RAIN AND THUNDER CHANCES WILL OCCUR LATER TONIGHT AS ANOTHER LINE DEVELOPS AND APPROACHES FROM THE WEST. SHOWERS MAY DEVELOP BEFORE THIS NEXT LINE OVER SOUTHERN ARKANSAS AND NORTH MISSISSIPPI AND TRACK NORTH...BUT COVERAGE SHOULD REMAIN LIMITED. VISIBLE SATELLITE DOES NOT SUGGEST ANY DEVELOPMENT IS IMMINENT. MVFR CIGS ARE EXPECTED BEFORE SUNRISE AT ALL SITES ALONG WITH MVFR VIS DUE TO RAIN AT JBR MKL AND MEM...CONTINUING THROUGH 18Z. WINDS SOUTHERLY AROUND 10KT WITH HIGHER GUSTS...SHIFTING SOUTHWESTERLY LATE IN THE PERIOD. 30 && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1101 AM CDT SUN MAY 10 2015 .DISCUSSION...LATEST WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES SHOW A MESOSCALE CONVECTIVE SYSTEM MOVING OVER WESTERN ARKANSAS...NORTHEAST OKLAHOMA...AND NORTHEAST TEXAS LATE THIS MORNING. REGIONAL WSR-88D RADAR TRENDS SHOW STORMS EXHIBITING QUASI-LINEAR CHARACTERISTICS OVER WESTERN ARKANSAS. AS OF 10 AM CDT ACROSS THE MID SOUTH...TEMPERATURES ARE IN THE 70S AT MOST LOCATIONS WITH MOSTLY SUNNY SKIES PREVALENT ACROSS MUCH OF THE AREA AS OF THIS MOMENT. LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL BE MAINLY WEST OF THE MISSISSIPPI RIVER THIS AFTERNOON WHERE BETTER FORCING AND INSTABILITY MAY RESIDE. FURTHER EAST...CONFIDENCE IS MUCH LOWER AND REDUCED RAIN CHANCES NORTH OF I-40 ACROSS WEST TENNESSEE DOWN TO ISOLATED COVERAGE. WILL UPDATE ALL ELEMENTS AS NEEDED TO ACCOUNT FOR THESE TRENDS. UPDATED GRIDS WILL BE AVAILABLE SHORTLY. CJC && .PREV DISCUSSION... /ISSUED 628 AM CDT SUN MAY 10 2015/ DISCUSSION... UPDATED FOR 12Z AVIATION. PREV DISCUSSION... /ISSUED 416 AM CDT SUN MAY 10 2015/ DISCUSSION... CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER 70S WITH LIGHT SOUTH WINDS. TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY. THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN. TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND 0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL. WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE STORMS IN THE HWO ON MONDAY. OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE 3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY. MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE 70S...LOWS IN THE 50S AND LOWER 60S. THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK. NEAR NORMAL TEMPS. SJM && .AVIATION... 12Z TAFS UPPER LEVEL DISTURBANCES WILL BRING SEVERAL ROUNDS OF SHOWERS AND STORMS TO JBR THROUGHOUT THE PERIOD...BUT MAINLY LATER FOR MEM...MKL AND TUP. IN THE HEAVIEST STORMS EXPECT MVFR/IFR CONDITIONS...OTHERWISE THE SITES WILL BE VFR. STRONGER SOUTH WINDS ANTICIPATED WITH GUSTS NEAR 20 KTS AT JBR AND MEM. WINDS WILL SUBSIDE SOME TONIGHT...BUT REMAIN GUSTY AT MEM AND JBR. JAB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
628 AM CDT SUN MAY 10 2015 .DISCUSSION... UPDATED FOR 12Z AVIATION. && .PREV DISCUSSION... /ISSUED 416 AM CDT SUN MAY 10 2015/ DISCUSSION... CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER 70S WITH LIGHT SOUTH WINDS. TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY. THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN. TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND 0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL. WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE STORMS IN THE HWO ON MONDAY. OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE 3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY. MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE 70S...LOWS IN THE 50S AND LOWER 60S. THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK. NEAR NORMAL TEMPS. SJM && .AVIATION... 12Z TAFS UPPER LEVEL DISTURBANCES WILL BRING SEVERAL ROUNDS OF SHOWERS AND STORMS TO JBR THROUGHOUT THE PERIOD...BUT MAINLY LATER FOR MEM...MKL AND TUP. IN THE HEAVIEST STORMS EXPECT MVFR/IFR CONDITIONS...OTHERWISE THE SITES WILL BE VFR. STRONGER SOUTH WINDS ANTICIPATED WITH GUSTS NEAR 20 KTS AT JBR AND MEM. WINDS WILL SUBSIDE SOME TONIGHT...BUT REMAIN GUSTY AT MEM AND JBR. JAB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
416 AM CDT SUN MAY 10 2015 .DISCUSSION... CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER 70S WITH LIGHT SOUTH WINDS. TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY. THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN. TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND 0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL. WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE STORMS IN THE HWO ON MONDAY. OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE 3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY. MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE 70S...LOWS IN THE 50S AND LOWER 60S. THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK. NEAR NORMAL TEMPS. SJM && .AVIATION... 06Z TAFS WEAK UPPER DISTURBANCE WAS MOVING EAST THROUGH AR AT 0445Z. THIS FEATURE WILL LIKELY HELP SUSTAIN SHRA/ISOLATED TSRA INTO THE MIDSOUTH OVERNIGHT. TS POTENTIAL WILL LIKELY BE BEST IN THE JBR AREA. MUCH OF SUNDAY SHOULD SEE VFR. SLIGHT RIDGING SHOULD KEEP MENTIONABLE TS CHANCES AT BAY UNTIL AFTERNOON...OR MORE LIKELY... EARLY SUNDAY EVENING AT JBR. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD-CRITTENDEN-CROSS-GREENE- LAWRENCE-LEE AR-MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1145 PM CDT SAT MAY 9 2015 .UPDATE... UPDATED FOR 06Z AVIATION DISCUSSION BELOW. && .PREV DISCUSSION... /ISSUED 806 PM CDT SAT MAY 9 2015/ UPDATE... MAIN UPDATE TO THE FORECAST WAS TO INCREASE PRECIP CHANCES ACROSS WESTERN PORTIONS OF THE CWA WHERE A COMPLEX OF SHOWERS AND THUNDERSTORMS WAS ONGOING. WHILE LARGE SCALE FORCING REMAINS WEAK...CONTINUED CONVERGENCE DRIVEN BY SOUTHEASTERLY FLOW AHEAD THE SYSTEM WILL AT LEAST MAINTAIN THIS COMPLEX FOR THE NEXT 1-2 HOURS...IF NOT LONGER. TEMPERATURES ACROSS THIS AREA WERE COOLER THAN FORECAST AS WELL...THEREFORE...ADJUSTED TRENDS TO REFLECT THIS THROUGH MIDNIGHT. A VERY COMPLEX SURFACE PATTERN WILL CONTINUE THROUGH TOMORROW WITH SEVERAL OUTFLOW BOUNDARIES LIKELY STREWN ACROSS THE CWA. PRECIP CHANCES MAY NEED TO BE ADJUSTED ONCE MORE LATER THIS EVENING AS TRENDS EVOLVE THROUGH THE NIGHT. TVT PREV DISCUSSION... /ISSUED 650 PM CDT SAT MAY 9 2015/ UPDATE... UPDATED FOR 00Z AVIATION DISCUSSION BELOW. PREV DISCUSSION... /ISSUED 320 PM CDT SAT MAY 9 2015/ DISCUSSION...SURFACE ANALYSIS THIS AFTERNOON PLACES A QUASI- STATIONARY BOUNDARY OVER PORTIONS OF SOUTHERN MISSOURI AND BACK INTO OKLAHOMA AND PORTIONS OF THE TEXAS/OKLAHOMA PANHANDLE. SHOWERS AND THUNDERSTORM COVERAGE HAS DECREASED IN COVERAGE ACROSS THE MID SOUTH THIS AFTERNOON AS THE ATMOSPHERE HAS STABILIZED SOMEWHAT. A CLUSTER OF SHOWERS ARE LOCATED ACROSS PORTIONS OF NORTH CENTRAL AND NORTHEAST ARKANSAS AS OF LATE THIS AFTERNOON. TEMPERATURES AS OF 3 PM CDT ARE IN THE UPPER 70S TO LOWER 80S AT MOST LOCATIONS. WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES OVER THE PAST FEW HOURS HAVE INDICATED ANOTHER MESOSCALE CONVECTIVE SYSTEM /MCS/ HAS DEVELOPED ACROSS OKLAHOMA AND THE RED RIVER VALLEY OF TEXAS. WRF/GFS/ECMWF MODELS INDICATE THIS ACTIVITY SHOULD REMAIN MAINLY WEST OF THE FORECAST AREA THIS EVENING. INTERESTINGLY ENOUGH...THE 19Z HRRR INDICATES CONVECTIVE ACTIVITY OVER NORTHEAST TEXAS/EASTERN OKLAHOMA...AND SOUTHWEST ARKANSAS MAY SPREAD INTO PORTIONS OF THE MID SOUTH ALONG AND WEST OF THE RIVER BY EARLY TO MIDDLE EVENING. THIS HIGH RESOLUTION MODEL/S OUTPUT MAY BE TRYING TO SUGGEST A COLD POOL DEVELOPING UPSTREAM AND BRINGING THE CONVECTION INTO THE FORECAST AREA. WILL GO WITH CHANCE POPS ALONG AND WEST OF THE MISSISSIPPI RIVER TONIGHT. EVENING SHIFT WILL MONITOR MESOSCALE TRENDS AND ADJUST FORECAST AS NECESSARY ESPECIALLY IF THE OUTLYING HRRR ENDS UP BEING THE CORRECT SHORT TERM FORECAST SOLUTION. SHORT TERM MODELS INDICATE SOUTHWEST FLOW ALOFT WILL REMAIN IN PLACE ACROSS THE MID SOUTH ON SUNDAY WITH MOST IF NOT ALL SHOWERS AND THUNDERSTORMS OCCURING UPSTREAM OF THE MID SOUTH. CONSEQUENTLY...HAVE KEPT POPS ISOLATED AT BEST DURING THE DAY WITH THE EXCEPTION OF EXTREME NORTHEAST MISSISSIPPI. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL DEVELOP AND SPREAD INTO THE MID SOUTH SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS INTO THE MID SOUTH. THE BEST UPPER LEVEL FORCING AND FAVORABLE WINDS WILL MOVE NORTHEAST OF THE FORECAST AREA BY MONDAY. SUFFICIENT INSTABILITY...0-6 KM BULK SHEAR AND THE APPROACHING FRONT MAY BE ENOUGH TO PRODUCE A CONDITIONAL THREAT FOR A FEW STRONG TO PERHAPS SEVERE THUNDERSTORMS ACROSS THE MID SOUTH LATE SUNDAY NIGHT INTO MONDAY. THIS FRONT IS EXPECTED TO PUSH SOUTH OF THE FORECAST AREA BY TUESDAY AFTERNOON/TUESDAY NIGHT AND BRING MAINLY RAIN FREE WEATHER THROUGH WEDNESDAY NIGHT. SHOWER/THUNDERSTORM CHANCES WILL RETURN LATE NEXT WEEK AS THE FRONT RETURNS BACK NORTH ACROSS THE MID SOUTH. CJC && .AVIATION... 06Z TAFS WEAK UPPER DISTURBANCE WAS MOVING EAST THROUGH AR AT 0445Z. THIS FEATURE WILL LIKELY HELP SUSTAIN SHRA/ISOLATED TSRA INTO THE MIDSOUTH OVERNIGHT. TS POTENTIAL WILL LIKELY BE BEST IN THE JBR AREA. MUCH OF SUNDAY SHOULD SEE VFR. SLIGHT RIDGING SHOULD KEEP MENTIONABLE TS CHANCES AT BAY UNTIL AFTERNOON...OR MORE LIKELY... EARLY SUNDAY EVENING AT JBR. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
400 PM CDT SUN MAY 10 2015 .DISCUSSION... ALL EYES ARE UPON CENTRAL TEXAS WHERE SPC HAS MODERATE RISK OF SEVERE STORMS AND THERE HAS ALREADY BEEN ONE TORNADIC STORM TO PUSH THROUGH DENTON TX. SFC ANALYSIS OVER SE TX HAS TYPICAL WARM SECTOR AIRMASS WITH GUSTY SE WINDS AND DEWPOINTS IN THE LOW 70S. WATER VAPOR IMAGERY SHOWS UPPER LOW OVER C PLAINS WITH ELONGATED TROUGH AXIS STRETCHING BACK INTO THE S ROCKIES AS EXPECTED YESTERDAY. UPPER AIR ANALYSIS SHOWS JET STREAK COMING OUT OF MEXICO WHICH LATEST RAP ANALYSES HAVE OVER S TX AND JUST STARTING TO REACH SE TX. JET STREAK SHOULD MOVE OVER THE AREA BY 03Z TONIGHT SO THINK ANY CAPPING MAY ERODED BY LARGE SCALE ASCENT. LATEST HRRR RUNS HAS CONVECTION NOW OVER C TX FORMING A SQUALL LINE AND PUSHING INTO THE BRAZOS VALLEY AFTER MIDNIGHT TO 3AM. THIS EVOLUTION INTO SOME BOWING SEGMENTS SUPPORTS SPC ENHANCED/SLIGHT RISK OF SEVERE FOR TONIGHT. GIVEN SHEAR/INSTABILITY PARAMETERS FOR TONIGHT...THINK THIS KIND OF CONVECTION WILL CERTAINLY BE POSSIBLE. MONDAY LOOKS LIKE THERE WILL BE PLENTY OF RECOVERY IN THE AIRMASS FOR IT TO DESTABILIZE WITH MODERATE TO HIGH CAPE BY THE AFTERNOON. DEEP LAYER SHEAR SEEMS TO WEAKEN BUT LOW LEVEL WIND FIELDS LOOK MUCH LESS THAN THE LAST COUPLE OF DAYS. A FRONTAL BOUNDARY DOES PUSH INTO N TX WHICH MAY SLACKEN THE PRESSURE GRADIENT ACROSS THE AREA. FRONT MAY BE THE FOCUS FOR SOME SEVERE STORMS WITH HEAVY RAINFALL FOR NORTHERN PORTIONS OF THE AREA. TROUBLE PART OF THE FORECAST IS THAT MODELS ARE NOT ALL THAT AGGRESSIVE WITH PRECIP MONDAY DESPITE A MUCH WEAKER CAP AND FAVORABLE UPPER LEVEL PARAMETERS. NOT ONLY THAT PRECIP WATER VALUES INCREASE TO AROUND 1.8 INCHES AND THEN OVERNIGHT AT 06Z TUE GFS SHOWS 2 INCH PRECIP WATER VALUES. THIS IS JUST AS A SHORT WAVE TROUGH MOVES OVER THE REGION. MODELS CONTINUE TO HIT HILL COUNTRY AND S TX TO THE COASTAL PLAIN WITH QUITE A BIT OF PRECIP WHILE PRECIP TOTALS FOR SE TX REMAIN SOMEWHAT LOW GIVEN THE SITUATION. ONE OF THE FEW MODELS THAT DOES PRODUCE QUITE A BIT OF PRECIP OVER THE AREA IS THE 12Z WRF-ARW WHICH BRINGS A SQUALL LINE INTO THE AREA FROM S TX CONSISTENT WITH UPPER LEVEL FORCING FROM THE SHORTWAVE. OVERALL KEPT POPS ON THE HIGH SIDE BUT PINNING DOWN THE DETAILS IS STILL A CHALLENGE. WPC SEEMS TO AGREE WITH HEAVY RAINFALL THREAT AS MOST OF THE AREA MON/TUE IS IN A SLIGHT RISK FOR EXCESSIVE RAINFALL. LOOKING AT 3HR FFG VALUES...NEED A GOOD 4-5 INCHES OF RAIN IN A 3 HR PERIOD TO GET FLASH FLOODING. CAN HOLD OFF ON ANY FLOOD WATCH AND SEE WHAT HAPPENS WITH FIRST COUPLE ROUNDS OF PRECIP. THIS WILL HELP DETERMINE THE NEED FOR A WATCH GIVEN THE UNCERTAINTY IN THE FORECAST. BEYOND TUE IT LOOKS LIKE LATE WED/THUR MAY BE ANOTHER ROUND FOR HEAVY RAINFALL. AGAIN THE FORECAST WILL KEEP HIGH RAIN CHANCE GOING THROUGH THUR AND THEN TAPER OFF FOR THE REST OF THE WEEK. THE SET UP FOR THURSDAY IS VERY SIMILAR WITH A SHORT WAVE TROUGH MOVING ACROSS THE AREA. BIG DIFFERENCE IS THAT THE ECMWF SEEMS TO HAVE THIS WAVE COMING ACROSS WED AFTERNOON WITH THE GFS HAVING TWO WEAK WAVES...ONE WED AFTERNOON AND ANOTHER BY 12Z THUR. GOING INTO THE END OF THE WEEK...UPPER LEVEL RIDGING DEVELOPS OVER TX AND SHOULD SUPPORT LOWER POPS AND A DRY FORECAST. THIS MAY ALSO ALLOW FOR MAX TEMPS IN THE UPPER 80S. 39 && .MARINE... MODERATE TO STRONG SOUTHEAST WINDS AND ELEVATED SEAS ARE EXPECTED TO CONTINUE OVER THE BAYS AND COASTAL WATERS TONIGHT AS THE PRESSURE GRADIENT REMAINS TIGHT ACROSS THE AREA. A WEAK FRONTAL BOUNDARY IS STILL EXPECTED TO EDGE INTO THE NORTHERN PARTS OF SOUTHEAST TEXAS LATE TONIGHT AND ON INTO EARLY MONDAY MORNING. THIS FRONT WILL HELP TO WEAKEN THE GRADIENT AND ALLOW FOR DECREASED WINDS AND SEAS FOR THE FIRST PART OF THE WEEK. AS THE FRONT SLOWLY WASHES OUT...ONSHORE WINDS ARE EXPECTED TO SLOWLY INCREASE DURING THE LATTER PART OF THE WEEK AND ON INTO NEXT WEEKEND. THE PERSISTENT ONSHORE WINDS CONTINUE TO SUPPORT STRONG RIP CURRENTS AND THE POSSIBILITY OF ELEVATED TIDES. LEVELS COULD APPROACH 3 FEET FOR LOCATIONS IN AND AROUND THE HOUSTON SHIP CHANNEL AND ALONG THE GULF FACING BEACHES OF THE BOLIVAR PENINSULA THIS AFTERNOON AND THIS EVENING. WAVE RUN-UP HAS THE POTENTIAL TO BE A PROBLEM FOR LOW LYING AREAS ALONG THE BOLIVAR PENINSULA. 42 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 72 84 68 76 68 / 80 60 80 70 60 HOUSTON (IAH) 74 85 70 81 70 / 30 60 70 70 40 GALVESTON (GLS) 76 82 75 80 74 / 20 50 60 60 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...HIGH RIP CURRENT RISK UNTIL 6 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON... MATAGORDA. GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY. SMALL CRAFT ADVISORY UNTIL 6 AM CDT MONDAY FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...39 AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1235 PM CDT SUN MAY 10 2015 .AVIATION... SCT/BKN DECKS AROUND 4000 FEET ARE ANTICIPATED THIS AFTERNOON AT OUR NORTHERN SITES (IAH/CXO/UTS/CLL) WITH POSSIBLE MVFR CEILINGS (2000-3000 FEET) AT OUR SOUTHERN SITES (HOU/SGR/LBX/GLS). RADAR IS SHOWING SOME SCATTERED -SHRA BEGINNING TO DEVELOP ACROSS THE AREA TOO...SO WILL HAVE VCSH TO COVER THAT FOR NOW. IF WE WARM UP ENOUGH... SOME TSRA WILL BE POSSIBLE. EXPECT SSE/SE WINDS TO BE AROUND 15 TO 20 KNOTS AND GUSTY. THIS EVENING AND OVERNIGHT AS WINDS DECREASE...EYES BEGIN TO TURN TOWARD A LINE OF SHRA/TSRA EXPECTED TO DEVELOP OFF TO OUR W AND NW. LAST COUPLE OF HRRR MODEL RUNS HAVE BEEN SHOWING THIS POSSIBLE STRONG/SEVERE LINE MOVING INTO THE CLL/UTS AREAS LATER THIS EVENING. HAVE GONE AHEAD AND ADDED VCTS TO THOSE TAFS TO ACCOUNT FOR THIS POSSIBILITY. FURTHER SOUTH...NOT REAL CONFIDENT ON WHAT THIS POSSIBLE LINE OF STORMS WILL LOOK LIKE AS IT SLOWLY EDGES ITS WAY TO THE E AND SE TOWARD THE CXO/IAH AREA. SINCE IT HAS A CHANCE ON STAYING INTACT...WENT AHEAD AND ADDED VCTS AT CXO BEFORE SUNRISE AND BETWEEN IAH AND GLS AFTER SUNRISE. EXPECT TAF AMENDMENTS LATER THIS AFTERNOON AND THIS EVENING AS WE SEE HOW THIS LINE TAKES SHAPE. 42 && .PREV DISCUSSION... /ISSUED 1039 AM CDT SUN MAY 10 2015/ UPDATE... MORNING FORECAST UPDATE. DISCUSSION... THUNDERSTORM ACTIVITY CONTINUES TO INCREASE OVER THE NW HILL COUNTRY NE TOWARDS C TX. TORNADO WATCH HAS BEEN ISSUED TO THE W AND NW OF HGX FORECAST AREA. SPC HAS SLIGHT RISK OF SEVERE STORMS MAINLY FOR TONIGHT NORTH OF A BRENHAM TO LUFKIN LINE. AN ENHANCED RISK OF SEVERE STORMS IS JUST TO THE NW OF A COLLEGE STATION TO CROCKETT LINE. THE EXPECTATION IS THAT A LINE OF SCATTERED STORMS WILL FORM OVER C TX AND THEN FORM A SOLID SQUALL LINE LATER THIS AFTERNOON AND TONIGHT. THIS SYSTEM COULD THEN MOVE INTO SE TX. THIS AFTERNOON THERE WILL BE QUITE A BIT OF INSTABILITY AND STRONG SHEAR TO SUPPORT ROTATING STORMS OVER C TX HENCE THE TORNADO WATCH. INSTABILITY SHOULD DECREASE THIS EVENING OVER SE TX AND NOT BE QUITE AS SUPPORTIVE OF SEVERE STORMS. THE OTHER QUESTION FOR SEVERE WEATHER OVER SE TX WILL BE CAPPING. LOOKING AT 12Z SOUNDINGS FROM DRT...CRP...LCH IT IS HARD TO GET A HANDLE ON THE CAPPING OVER OUR AREA. DRT AND LCH DO NOT HAVE MUCH OF A CAP SO LOOKS LIKE THERE WILL BE A TIGHT GRADIENT ON WHERE THE CAP EXISTS OR IS WEAK ENOUGH THAT HEATING CAN OVERCOME THE CAP. CRP SHOWS A SUBSTANTIAL CAP BUT LOOKING AT AMDAR/ACARS SOUNDINGS OVER THE AREA THINK HOUSTON IS JUST ENOUGH CAPPED TO LIMIT THUNDERSTORM ACTIVITY. AREAS TO NORTH WHERE SPC HAS SEVERE OUTLOOK WILL NEED TO BE MONITORED. FOR NOW ONLY CHANGES TO THE FORECAST WAS TO DECREASE POPS A BIT THIS AFTERNOON AND ADJUST TONIGHT`S POPS FOR TIMING OF CONVECTION MOVING INTO THE AREA FROM C TX. FOR THE AFTERNOON FORECAST WE ARE REALLY GOING TO HAVE TO LOOK HARD AT RAINFALL TOTALS AND POTENTIAL FOR HEAVY RAINFALL/FLOODING. RIGHT NOW WPC HAS MUCH OF SE TX IN A SLIGHT RISK OF EXCESSIVE RAINFALL FOR MONDAY AND TUESDAY. THIS IS ALSO WHEN SEVERAL ATMOSPHERIC PARAMETERS COMBINE TO SUPPORT THAT THREAT. BUT THE DETAILS OF HOW MUCH RAIN...WHERE AND WHEN ARE STILL A CHALLENGE DUE TO TIMING A SHORTWAVE TROUGH COMING ACROSS THE AREA. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 86 72 84 68 77 / 30 70 70 80 80 HOUSTON (IAH) 86 73 86 71 81 / 30 30 60 80 60 GALVESTON (GLS) 83 76 83 74 80 / 20 20 50 70 70 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...HIGH RIP CURRENT RISK UNTIL 6 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON... MATAGORDA. GM...SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM... WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ DISCUSSION...39 AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1138 PM CDT SAT MAY 9 2015 .AVIATION... VFR AND LIGHT WINDS EXPECTED THRU THE TAF PERIOD WITH THE EXCEPTION OF THE POSSIBILITY OF SOME LOW CLOUDS AT KCDS THIS MORNING. KCDS REMAINS ON THE MOIST SIDE OF A SFC TROUGH THAT HAS BEEN MOSTLY STATIONARY THRU THE EVENING BUT WILL BEGIN TO MOVE EWD AGAIN TOWARD SUNRISE. SEEING SOME AREAS OF LOW CLOUD NORTH AND NE OF KCDS ATTM WITH MODELS CONTINUING TO INDICATE A WINDOW FOR IFR OR MVFR CIGS BTWN 06Z AND 12Z. && .PREV DISCUSSION... /ISSUED 903 PM CDT SAT MAY 9 2015/ UPDATE... HAVE REMOVED EVENING THUNDER MENTION FOR THE FAR ERN SLIVER OF THE FCST AREA AS THAT THREAT HAS MOVED EAST OF THE REGION. TEMP AND HUMIDITY FCST FOR THE ROLLING PLAINS AND FAR SERN PANHANDLE PROBLEMATIC AS THE DRYLINE DID NOT QUITE GET ENTIRELY EAST OF THE FCST AREA. CURRENTLY SEEING A BATTLE BETWEEN OUTFLOW-REINFORCED MOIST AIRMASS MOVING EWD AND THE DRYLINE/SFC TROUGH. THIS TROUGH SHOULD END UP MOVING TO THE EAST AGAIN AS THE UPPER LOW OVER COLORADO MOVES ONTO THE PLAINS. HOWEVER UNTIL THEN...DEW POINTS IN THE 60S WILL KEEP TEMPS THERE MILD UNTIL LATE TONIGHT AND MAY SEE SOME LOW CLOUDS MOVE INTO THE CHILDRESS AREA AROUND MIDNIGHT AND LINGER FOR SEVERAL HOURS BEFORE DRIER LOW LEVEL AIR CAN FINALLY SWEEP THE MOISTURE EWD. PREV DISCUSSION... /ISSUED 634 PM CDT SAT MAY 9 2015/ AVIATION... DRYLINE HAS SHIFTED AS FAR EAST AS JUST OUTSIDE KCDS. GUSTY WSW WINDS BEHIND SHOULD DIMINISH BY MID-EVENING WITH VFR CONDITIONS EXPECTED AT BOTH KLBB AND KPVW. HOWEVER...EAST OF THE DRYLINE VCTY KCDS RICH LOW LEVEL MOISTURE REMAINS. WITH A PUSH OF THE DRYLINE A BIT TO THE WEST TONIGHT WOULD EXPECT MOISTURE TO BE REINFORCED FROM DOWN THE RED RIVER VALLEY. THUS HAVE SIDED WITH THE HI-RES HRRR AND INTRODUCED LOW CLOUDS IN THE KCDS TAF FROM LATE EVENING TO AROUND SUNRISE SUNDAY. MAY VERY WELL END UP BEING IFR THERE IF THESE CLOUDS DEVELOP...BUT HAVE STARTED JUST ABOVE THAT CUTOFF ATTM. PREV DISCUSSION... /ISSUED 534 PM CDT SAT MAY 9 2015/ SHORT TERM... PACIFIC FRONT/DRYLINE HAS SURGED EAST THIS AFTERNOON AS EXPECTED AS DRY SLOTTING HAS MOVED IN ALOFT ACROSS THE REGION. CORE OF THE UPPER LOW CURRENTLY NEAR THE FOUR CORNERS REGION WILL LIFT TOWARD THE FRONT RANGE INTO THIS EVENING WITH A SURFACE LOW HUGGING THE FRONT RANGE/CENTRAL HIGH PLAINS. DEWPOINTS HAVE CRASHED INTO THE 20S/30S ACROSS MUCH OF THE CAPROCK...BUT OUTFLOW BOUNDARIES FROM THIS MORNING/S CONVECTION COUPLED WITH STOUT MOIST SOUTHEASTERLY FLOW ACROSS THE BIG COUNTRY HAVE HUNG UP THE DRYLINE ON A LINE FROM LAKE MACKENZIE TO ROARING SPRINGS TO HASKELL. HAVE LEFT A SLIGHT CHANCE FOR STORMS IN THE FORECAST ALONG AND EAST OF HIGHWAY 83 AS SURFACE CONVERGENCE ALONG THIS BOUNDARY MAY BE JUST ENOUGH TO INITIATE ISOLATED DEVELOPMENT WHEN COUPLED WITH CONTINUED WEAK HEIGHT FALLS ALOFT. THIS CHANCE WILL BE HIGHLY CONDITIONAL ON WHETHER ENOUGH HEATING WILL BE ABLE TO OCCUR IN A WORKED OVER/COLD POOL PLAGUED AIRMASS. WILL CONTINUE TO SEE A FEW LOBES OF ADDITIONAL ENERGY ROUND THE BASE OF THE UPPER LOW THROUGH EARLY SUNDAY...BUT DRIER AIR COURTESY OF DOWNSLOPE SURFACE WINDS WILL KEEP STORMS MAINLY CONFINED EAST OF THE FAR EASTERN EDGE OF THE ROLLING PLAINS. SUNDAY MORNING LOOKS TO BRING THE NEXT/LAST APPRECIABLE ROUND OF UPPER ENERGY TOWARD WEST TEXAS...SO WILL KEEP A MENTION SOUTHEAST OF A GUTHRIE TO ASPERMONT LINE AS 40 DEGREE DEWPOINTS MAY BE ENOUGH TO SPARK A QUICK STORM. OTHERWISE...BREEZY WEST/SOUTHWEST WINDS SHOULD ACCOMPANY TEMPERATURES TOPPING OUT IN THE MID 70S NORTHWEST TO LOW 80S SOUTH AND EAST UNDER MOSTLY CLEAR SKIES. LONG TERM... WE/LL SEE A BREAK IN OUR ACTIVE WEATHER PATTERN THROUGH MONDAY...BUT THE CHANCE FOR SHOWERS AND T-STORMS WILL INCREASE AGAIN NEXT WEEK. THE COLD FRONT WILL BE EXITING THE FORECAST AREA MONDAY MORNING WITH BREEZY NORTHERLY WINDS DIMINISHING AND SWINGING AROUND TO THE E-SE BY MONDAY EVENING. IT WILL BE ON THE COOL SIDE BEHIND THE FRONT MONDAY WITH HIGHS MAINLY IN THE UPPER 60S AND LOWER 70S. SHORTWAVE RIDGING WILL DEVELOP OVER WEST TEXAS TUESDAY DOWNSTREAM OF A UPPER TROUGH MOVING ACROSS THE WEST COAST. INDICATIONS ARE THAT THIS TROUGH WILL BE PROGRESSIVE AND MAY BEGIN TO AFFECT THE REGION BY TUESDAY EVENING. THE NAM IS THE MOST BULLISH OF THE MODELS WITH THE QPF FORECAST...GENERATING A SWATH OF RAIN COMING IN FORM THE SW TUES AFTERNOON AND EVENING. THIS MAY BE OVERDONE GIVEN THAT IT WILL TAKE SOME TIME FOR LOW-LEVEL MOISTURE TO RECHARGE AND THE ECMWF AND GFS ARE SLOWER WITH THE LIFT. WE WILL MAINTAIN A CHANCE OF PRECIP IN THE SW SPLNS...TAPERING DOWN FARTHER EAST TUESDAY EVENING AND OVERNIGHT. THE GFS AND ECMWF STILL INDICATE THAT WED WILL BE THE PRIMARY PERIOD FOR RAIN CHANCES WITH A WELL-DEVELOPED SHORTWAVE OUT OF NM AND ACROSS WEST TEXAS...AT ROUGHLY THE SAME TIME DEEP GULF MOISTURE IS MOVING BACK INTO THE AREA. PROGGED QPF AMOUNTS ARE QUITE HIGH...WITH A SIMILAR APPEARANCE TO OUR LAST STRONGLY FORCED CONVECTION MAY 5TH. HOWEVER...THIS IS STILL 5 DAYS OUT AND WE MAY NOT SEE LIFT AND MOISTURE QUITE AS SYNCHRONIZED THIS TIME. SHORTWAVE LIFTS NWD AWAY FROM THE AREA ON THURSDAY BUT THE UPPER TROUGH TO OUR WEST WILL BE QUICK TO RELOAD AS NEXT ROUND OF ENERGY DROPS INTO THE SW. THE EMCWF AND GFS BEGIN TO DIVERGE BY THIS TIME AS THE ECMWF DROPS A UPPER LOW ALL THE WAY INTO SRN CALIFORNIA WHILE THE GFS BREAKS THE ENERGY UP INTO SEVERAL PIECES MOVING ACROSS THE GREAT BASIN AND 4-CORNERS REGIONS. EITHER WAY LOW-LEVEL MOISTURE SHOULD BE DRAWN WEST INTO ERN NM AND PERTURBATIONS IN THE SWRLY FLOW OVER WTX SHOULD BE SUFFICIENT TO SUPPORT AT LEAST SOME DIURNAL T- STORM DEVELOP EACH AFTN AND EVENING FRI...SAT AND PERHAPS INTO SUNDAY JUST DEPENDING ON HOW THE UPPER TROUGH/LOW ACROSS THE WEST EVOLVES. FIRE WEATHER... WARM...DRY AND BREEZY CONDITIONS WILL PERSIST THROUGH EARLY EVENING ACROSS THE CAPROCK. OVERNIGHT MOISTURE RECOVERY WILL BE POOR AS THE DRYLINE REMAINS TO THE EAST. SIMILAR CONDITIONS ARE EXPECTED ACROSS THE ENTIRE FORECAST AREA ON SUNDAY. HOWEVER...THE FIRE WEATHER CONCERNS WILL REMAIN LOW DUE TO THE RECENT WIDESPREAD WETTING RAINS A GREENUP. A COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT AND MONDAY MORNING BRINGING A PERIOD OF GUSTY NORTHERLY WINDS. SEASONABLE COOL AND DRY CONDITIONS ARE EXPECTED MONDAY...WITH MOISTURE LEVELS AND RAIN CHANCES ON THE INCREASE BY LATE TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 44 74 41 69 / 0 0 10 0 TULIA 48 74 44 69 / 0 0 10 0 PLAINVIEW 45 75 45 69 / 0 0 10 0 LEVELLAND 46 77 46 71 / 0 0 10 0 LUBBOCK 46 78 47 71 / 0 0 10 0 DENVER CITY 48 78 47 73 / 0 0 0 0 BROWNFIELD 48 79 48 73 / 0 0 10 0 CHILDRESS 59 81 51 71 / 0 0 10 0 SPUR 54 81 51 71 / 0 0 10 0 ASPERMONT 60 83 54 73 / 10 20 10 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
923 PM CDT MON MAY 11 2015 .UPDATE... IT WILL REMAIN WINDY OVERNIGHT AS COLD AIR ADVECTION KEEPS LOW- LEVEL LAPSE RATES STEEP AND MIXED UP TO 30 KT WINDS AROUND 2K FT. ADJUSTED NEAR TEMPS DOWN A NUDGE BUT LOWS IN THE MID-40S LOOK ON TRACK GIVEN CLOUDS AND MIXING. LATEST NAM12 SUPPORTS HRRR AND KEEPS ANY SPOTTY LIGHT SHOWERS/DRIZZLE MAINLY ACROSS OUR NRN COUNTIES WHICH CURRENT FORECAST COVERS WELL. && .AVIATION/06Z TAFS/... CIGS CONTINUE TO HOVER AROUND THE VFR/MVFR BREAK...WITH UPSTREAM OBS SUPPORTING SREF MVFR CIG PROBABILITIES INDICATING MVFR CLOUDS SHOULD REACH KMSN AND KUES...WITH A GOOD CHANCE FOR A PERIOD OF MVFR AT KMKE AND KENW AFTER 08Z. CIGS EXPECTED TO LIFT TO VFR LEVELS AROUND MIDDAY. WINDS WILL REMAIN GUSTY...WITH MIXING UP TO 30 KT WINDS AROUND 2K FT TO CONTINUE OVERNIGHT...WITH DEEPER MIXING TUESDAY KEEPING GUSTS AROUND 25 KTS THROUGH THE DAYLIGHT HOURS. && .MARINE... SMALL CRAFT ADVISORY CONTINUES FOR GUSTY WEST WINDS THAT WILL TURN WNW TUESDAY. GRADIENT BEGINS TO EASE IN THE EARLY AFTERNOON AS LOW PULLS AWAY AND HIGH PRESSURE BUILDS TOWARD LAKE MICHIGAN. END TIME OF ADVISORY MAY HAVE TO BE EXTENDED IF FULL SET OF 00Z DATA INDICATES A SLOWER EASING OF WINDS...LATEST NAM 925 MB WINDS STILL 25 KTS AT 00Z WED...WITH SBM FORECAST SOUNDINGS SHOWING MIXING UP TO 25 KT WINDS AS LATE AS 02Z BUT LOWERING QUICKLY AFTER. && .PREV DISCUSSION... /ISSUED 223 PM CDT MON MAY 11 2015/ TONIGHT - CONFIDENCE...MEDIUM COLD AND DRY ADVECTION TAKING PLACE WRAPPING AROUND SOUTH SIDE OF SURFACE LOW SHIFTING EAST FROM NRN WI. PRECIP TO THE EAST AND BREAKS IN THE CLOUD COVER WILL BE REPLACED BY STRATOCU FIELD ARRIVING FROM MN AND IA. GUSTY SW WIND REGIME WILL STAY IN PLACE WITH BUFKIT SOUNDINGS SHOW DECENT MIXING EVEN DURING THE OVERNIGHT HOURS. THE NAM IS MOST AGGRESSIVE WITH SHRA WRAPPING INTO THE NRN CWA WHILE THE GFS/ECMWF HOLD IT OFF TO THE NW OF THE CWA. WILL HAVE SOME SMALL POPS LATE ACROSS THE FAR NORTH TO MATCH UP WITH GRB/ARX AND TO ACCOUNT FOR THE NAM TRENDS. TUESDAY - CONFIDENCE...MEDIUM LOW LEVEL COLD POOL WILL PERSIST WITH 850 TEMPS RANGING FROM 0C TO -3C ACROSS SRN WI. UPPER LOW ACRS NRN WI WILL SHIFT WELL TO OUR EAST WITH MID LEVEL STILL SHOWING A CYCLONIC CURVATURE...THOUGH MORE HINTS OF NVA ON THE NAM. LLVL RH PROGS SHOW THE CLOUD COVER LINGERING THROUGH AT LEAST THE MORNING WITH SOME BREAKUP DURING THE AFTERNOON WITH COLUMN SHOWING LESS SATURATION WITHIN 900-800 MILLIBAR LAYER. BUFKIT DOES SHOW COLUMN MIXING TO 850 MILLIBARS SO GUSTY WNW WIND REGIME WILL PREVAIL. HIGHS MOSTLY IN THE MID/UPPER 50S. TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH. SURFACE HIGH PRESSURE MOVES IN TUESDAY NIGHT...CLEARING OUT ANY LINGERING CLOUDS AND ALLOWING WINDS TO BECOME CALM/LIGHT. THE DRY AIRMASS SHOULD BRING NEAR FROSTY TEMPS AFTER MIDNIGHT. MOST PLACES SHOULD BE IN THE 30S...WITH TEMPS LOW ENOUGH NORTH OF MADISON AND ACROSS PARTS OF THE SOUTHEAST...ALONG AND WEST OF THE KETTLE MORAINE SPINE...TO BRING SOME PATCHY FROST. WEDNESDAY WILL WARM TO THE LOWER/MID 60S WEST OF MADISON AS THE RIDGE BEGINS TO MOVE OFF. BUT THE EAST WILL STILL BE UNDER THE INFLUENCE OF A COOL EASTERLY FETCH OFF THE LAKE. SOME HIGH LEVEL CLOUDS MAY SPILL INTO THE AREA OVER THE TOP OF THE MID LEVEL RIDGE...SO SKY COVER IS SOMEWHAT IN QUESTION. THE RIDGE AXIS WILL CONTINUE TO SHIFT EAST WEDNESDAY NIGHT WITH CONTINUED INCREASING CLOUDS ANTICIPATED. THURSDAY AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM. AS THE RIDGE MOVES OFF...A DECENT MID LEVEL TROF WILL LIFT NORTHEAST INTO MINNESOTA AND WISCONSIN. THERE IS STRONG WARM AIR ADVECTION ACCOMPANYING THIS SYSTEM AS THE LOW LEVEL JET AHEAD OF THE LOW INCREASES TO 40 TO 50 KNOTS. THE SOUNDINGS LOOK RATHER STABLE...SO THE THUNDER THREAT WITH THIS LOOKS MINIMAL. BUT...WE COULD STILL HEAR SOME RUMBLES. HOPEFULLY...ANOTHER GOOD RAIN FOR OUR FARMING COMMUNITY. RAIN SHOULD SPREAD INTO THE AREA MAINLY AFTER MID DAY ON THURSDAY AND CONTINUE THROUGH THURSDAY NIGHT...DIMINISHING ON FRIDAY. FRIDAY NIGHT AND THIS WEEKEND...FORECAST CONFIDENCE IS MEDIUM. IT LOOKS LIKE A BREAK IN THE WET WEATHER SHOULD ARRIVE FRIDAY NIGHT WITH BRIEF HIGH PRESSURE MOVING THROUGH AHEAD OF THE NEXT LOW PRESSURE SYSTEM HEADING IN. RAIN CHANCES RETURN THIS WEEKEND WITH A BETTER CHANCE FOR STRONG THUNDERSTORMS BY SUNDAY AS A POTENT LOW PRESSURE SYSTEM AND COLD FRONT MOVE IN. NATURALLY...THERE IS MODEL DISAGREEMENT THIS FAR OUT...BUT THERE IS AGREEMENT THAT WE WILL BE IN A WARMER AIRMASS...SO LOOK FOR PLEASANT TEMPS. IT JUST MAY END UP BEING A BIT STORMY. AVIATION/00Z TAFS/...LOW PRESSURE ACRS NRN WI WILL CONTINUE TO MOVE EAST THIS PERIOD. WITH COLD FRONT TO THE EAST A GUSTY SW WIND USHERING IN A COOLER AND DRY AIRMASS. CLOUD DECREASE LATE THIS AFTN/EVE WILL BE SHORT LIVED AS CONSIDERABLE STRATOCU WILL WRAP INTO SRN WI WITH 850 MILLIBAR COLD AIR ADVECTION. THE MVFR CIGS ASSOCIATED WITH THIS CLOUD DECK WILL LIKELY LINGER INTO TUESDAY AS THERMAL TROUGH PERSISTS. BEST CHC SHRA LOOKS NORTH OF TAF SITES SO WILL LEAVE OUT THIS POTENTIAL FOR NOW. MARINE...GUSTY WSWLY WINDS DEVELOPING IN THE WAKE OF THE COLD FRONT. THIS WILL SCOUR OUT ANY REMAINING LAKE FOG WITH DRY AIRMASS TAKING HOLD. WINDS WILL TURN A BIT MORE TO THE WNW ON TUESDAY. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THESE GUSTY WINDS THROUGH TUESDAY. HIGHER WAVES WILL BE SEEN TOWARDS OPEN WATERS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT TUESDAY FOR LMZ643>646. && $$ UPDATE...REM TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR TUESDAY NIGHT THROUGH MONDAY...DAVIS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
152 AM EDT TUE MAY 12 2015 .SYNOPSIS... ANOTHER MILD AND HUMID NIGHT WITH DENSE FOG TONIGHT GIVES WAY TO ANOTHER WARM DAY WITH SOME SHOWERS AND THUNDERSTORMS POSSIBLE IN THE AFTERNOON AS THE REMNANTS OF ANA PASS BY. LARGE HIGH PRESSURE WILL BUILD ACROSS THE EASTERN U.S. WITH DRIER WEATHER THROUGH THE REMAINDER OF THE WEEK. AN APPROACHING WARM FRONT COULD BRING SCATTERED SHOWERS NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 150 AM UPDATE... A FEW SHOWERS HAVE DEVELOPED ACROSS NE CT THROUGH SE MA EARLY THIS MORNING. ADDITIONAL SHOWERS S OF LONG ISLAND ASSOCD WITH ANA REMNANTS WILL BE LIFTING N ACROSS THE COASTAL PLAIN THROUGH DAYBREAK. AN ISOLD TSTM IS POSSIBLE AS ELEVATED INSTABILITY PARAMETERS ARE MARGINAL. CONVECTIVE LINE MOVING THROUGH CENTRAL NY IS EXPECTED TO REMAIN WEST OF SNE THROUGH DAYBREAK. PREVIOUS DISCUSSION... BACKDOOR FRONT APPEARS TO HAVE STALLED FROM NE RI THROUGH PORTIONS OF SE MA. TEMPS IN THE 50S TO THE N AND E OF THE FRONT AND MAINLY 60S JUST TO THE S AND W. AS REMNANTS OF ANA APPROACHES LATE TONIGHT...HI-RES GUIDANCE LIFTS THE FRONT BACK TO THE N OVERNIGHT ACROSS RI AND SE MA. AREAS OF DENSE FOG HAVE OVERSPREAD THE IMMEDIATE S COAST THIS EVENING. WITH LOW LEVEL S/SW FLOW EXPECT DENSE FOG THREAT WILL BE CONFINED TO THE S COAST AND SE MA...AND ALONG NE MA COAST WHERE WINDS ARE EASTERLY. LATEST HRRR HAS LOWEST VSBYS ALONG THE S AND E COASTS SO WE TRIMMED THE DENSE FOG ADVISORY AWAY FROM THE COAST. FINALLY...HAVE INCREASED POPS ACROSS SE COASTAL MA AND CAPE COD FOR LATE TONIGHT AS REMNANTS OF ANA TRACK TO THE SOUTH. MODELS SHOW AREA OF DEEPER MOISTURE ALONG WITH SOME ELEVATED INSTABILITY AT THE NOSE OF A LOW LEVEL JET WHICH SHOULD BRING AN AREA OF SHOWERS OR AN ISOLD TSTM TO SE COASTAL NEW ENG. LATEST RAP SHOWS AN AREA OF MEASURABLE RAINFALL LATE TONIGHT OVERSPREADING PORTIONS OF RI AND SE MA. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... TOMORROW... THE EARLY MORNING WILL BE MARKED BY A FAIRLY ROBUST DECK OF LOW LVL CLOUDS AND FOG POSSIBLY AS FAR WEST AS THE CT VALLEY. THIS WILL TAKE SOME TIME TO BURN OFF DURING THE MORNING AS DIURNAL MIXING COMMENCES. EXACTLY HOW QUICKLY WILL DETERMINE THE THREAT FOR CONVECTION/SEVERITY AS A COLD FRONT APPROACHES FOR THE AFTERNOON. BY AFTERNOON...AS THE FRONT MAKES IT/S PASS/APPROACH...SOME BREAKS OF SUN ARE LIKELY ESPECIALLY FOR INTERIOR NRN MA AND WRN CT. THIS AREA WILL BE THE PLACE TO WATCH AS BUFKIT PROFILES SHOW MODEST CAPE VALUES APPROACHING 1000-1500 J/KG COMBINED WITH ABOUT 30 KT OF 0-3KM SHEAR. UPPER LVL PROFILES WILL BE DRYING HOWEVER RATHER QUICKLY SO IT/S A RACE AGAINST TIME AS TO WHETHER THE DRY AIR OR INSTABILITY WINS AS THE LOW LVL F-GEN SOURCE APPROACHES. HI-RES AND EVEN MORE COARSE GUIDANCE ALL SHOWING THE POSSIBILITY OF AFTERNOON CONVECTIVE ACTIVITY WITH THE FROPA...ESPECIALLY NRN INTERIOR MA AWAY FROM WHERE THE LOW LVL CLOUDS WILL HOLD IN. SLIGHT CHANCE OF A STRONG STORM GIVEN THE MODEST SHEAR VALUES...WHICH COINCIDES WELL WITH THE 18Z DAY TWO SWODY FROM SPC...WHICH HIGHLIGHTS A MARGINAL RISK. THERE WILL STILL BE SOME LEFTOVER LOW-LVL MOISTURE FROM ANA AHEAD OF THE FRONT...SO WILL ALSO NEED TO WATCH FOR HEAVIER RAIN. OTHER ISSUES FOR TOMORROW... FIRE WEATHER CONCERNS... AREAS WHERE THE CLOUD DISSIPATE WILL SEE LOW RELATIVE RH VALUES AND GIVEN DIURNAL MIXING...WIND GUSTS OF 25-30 MPH AT TIMES. THEREFORE...HAVE A MARGINAL RISK OF ELEVATED FIRE WEATHER DURING THE DAY IN SPITE OF THE T-STORM/SHRA POTENTIAL. FOR MORE ON THIS...SEE THE FIRE WEATHER SECTION BELOW. HIGH SURF... THE REMNANTS OF ANA WILL BRING 6 TO 10 FOOT SWELL TO OUR SOUTHERN COASTAL WATERS TOMORROW. THIS WILL BRING HIGH SURF AND DANGEROUS RIP CURRENTS TO OUR OCEAN EXPOSED SOUTH FACING BEACHES ON TUE. GIVEN RELATIVELY WARM TEMPS EXPECTED...WE MAY STILL HAVE TO CONSIDER A HIGH SURF ADVISORY EVEN THOUGH THE SUMMER SEASON HAS NOT OFFICIAL BEGUN. TUESDAY NIGHT... FINALLY...THE HIGHER DWPTS...DRIER AIR AND IMPROVING CONDITIONS WILL BE MOVING ACROSS THE REGION FROM W-E DURING THE OVERNIGHT HOURS. LEFTOVER TSRA/SHRA WILL GENERALLY DIMINISH WITH THE LOSS OF DIURNAL HEATING...SO THERE MAY BE A FEW CLOUDS STILL TO CONTEND WITH EARLY. GIVEN THE MASS FIELDS ALSO SUPPORT A MODERATE PRES GRADIENT...TEMPS ARE NOT LIKELY TO FALL AS LOW AS THEIR POTENTIAL DESPITE THE DROPPING DWPTS. MINS MAINLY IN THE MID 40S AND LOW 50S. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... HIGHLIGHTS... * BREAK IN THE HEAT ON WEDNESDAY WITH NORMAL TEMPS * HIGH PRESSURE ON THURS & FRI KEEP CONDITIONS DRY * RAIN RELIEF POSSIBLE OVER THE WEEKEND WITH APPROACHING LOW OVERVIEW... FORECAST GUIDANCE CONTINUES TO BE IN GOOD AGREEMENT FOR MOST OF THE EXTENDED. NOTICED 11.12Z GUIDANCE LEANED TOWARDS THE 11.00Z GFS FROM LAST NIGHT IN BRINGING PRECIP INTO THE REGION FOR THE WEEKEND. OTHERWISE BY LATE WEEKEND INTO EARLY NEXT WEEK APPEARS THAT THE EC IS MORE AMPLIFIED IN BUILDING A STOUT RIDGE OVER NEW ENGLAND COMPARED TO THE GFS. THIS COULD MAKE THINGS LESS STORMY THEN PREVIOUSLY THOUGHT. APPEARS TEMPS WILL LEAN MORE TOWARDS OR JUST ABOVE NORMAL OVER THE LONG TERM. COULD SEE AN INCREASE IN THE HEAT BY NEXT WEEK. DETAILS... * WEDNESDAY...HIGH CONFIDENCE. SECONDARY COLD FRONT WILL PASS THROUGH THE REGION PUSHING UPPER LEVEL TROUGH OFFSHORE AND TEMPS ALOFT TO COOL OVER THE AREA. WINDS WILL SWITCH TO A MORE NW FLOW...ALLOWING FOR GOOD DOWNSLOPING. PARTLY SUNNY SKIES WILL ALLOW FOR TEMPS TO WARM INTO THE UPPER 60S...WHICH IS NEAR NORMAL! DID LOWER DEWPOINTS AND INCREASE WIND GUSTS VERSUS GUIDANCE AS MIXING ON WED WILL BE VERY GOOD. THIS WILL BRING A RISK OF FIRE WEATHER CONCERNS TO THE REGION. DETAILS IN THE FIRE WEATHER SECTION BELOW. BECAUSE OF THE FALLING TEMPS ALOFT AND MARGINAL MOISTURE FIELD... HAVE INSERTED A LOW CHANCE FOR AN ISOLATED SHOWER FOR FRANKLIN COUNTY. CONFIDENCE IS LOW...BUT CANNOT RULE IT OUT. TEMPS ALOFT WILL DROP THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS. IN FACT 850MB COULD DROP DOWN TO 0C OVERNIGHT. THIS COMBINED WITH CLEAR SKIES AND DECOUPLE WINDS WILL ALLOW FOR RADIATIONAL COOLING OVERNIGHT. TEMPS WILL DROP INTO THE LOWER 40S. COULD SEE A FEW UPPER 30S BUT HAVE A LOW CONFIDENCE ON FROST DEVELOPMENT IN THE VALLEY LOCALS ACROSS THE NW PORTION OF THE AREA. * THURSDAY AND FRIDAY...HIGH CONFIDENCE. HIGH PRESSURE WILL MOVE RIGHT ON IN FOR THURSDAY AND LAST INTO FRIDAY. THIS WILL ALLOW FOR DRY WEATHER AND PLENTY OF SUNSHINE. HAVE AN INCREASE CHANCE THAT SEA BREEZES WILL DEVELOP ACROSS THE COASTLINES FOR BOTH DAYS. TEMPERATURES WILL WARM ABOVE AVERAGE ONCE AGAIN...WITH HIGHS IN THE LOW 70S ON THURSDAY AND MID 70S ON FRIDAY AWAY FROM THE COASTLINES. * THE WEEKEND...MODERATE CONFIDENCE. HIGH PRESSURE WILL MOVE SOUTH AND OFFSHORE ALLOWING FOR APPROACHING LOW PRESSURE FROM THE WEST TO PUSH A WARM FRONT OVER THE REGION. DEPENDING ON WHERE THIS WARM FRONT SETS UP WE COULD SEE A FEW ROUNDS OF SHOWERS AS A WAVE OR TWO MOVES THROUGH THE AREA. NOT EXPECTING A DROUGHT BUSTER AS WE NEED ABOUT 3-5 INCHES...BUT SOME RAIN RELIEF TO THE REGION IS ANTICIPATED. * MONDAY...LOW CONFIDENCE. MONDAY IS LOOKING WARM BUT STILL UNCERTAIN ON PRECIP CHANCES AS THE PATTERN WILL BE FOCUSED ON IF THE RIDGE WILL BUILD OR NOT. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. THROUGH 12Z...WIDESPREAD IFR/LIFR CONDITIONS IN STRATUS AND FOG...ALTHOUGH SOME MVFR IN THE CT VALLEY. DENSE FOG CONFINED TO THE S COAST. SCT SHOWERS AND ISOLD TSTM NE CT THROUGH SE MA. TODAY...MODERATE CONFIDENCE. IFR/LIFR STRATUS AND FOG WILL IMPROVE TO VFR BY MIDDAY...BUT AREAS OF IFR WILL LIKELY PERSIST ALONG THE IMMEDIATE S COAST AND ESPECIALLY THE ISLANDS INTO THE AFTERNOON. CHANCE OF A FEW THUNDERSTORMS IN THE AFTERNOON. SW GUSTS TO 25 KT POSSIBLE RI AND SE MA DURING THE AFTERNOON. TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT IFR CONDITIONS POSSIBLE INTO THE EVENING ACROSS OUTER CAPE/ISLANDS. WEDNESDAY...HIGH CONFIDENCE. VFR CIGS. NW GUSTS TO 25 KT. KBOS TAF...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN TIMING OF IMPROVEMENT TO VFR. KBDL TAF...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN TIMING OF IMPROVEMENT TO VFR. OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...HIGH CONFIDENCE. THURSDAY-FRIDAY...VFR. LIGHT AND VARIABLE WINDS. SEA BREEZES POSSIBLE ON BOTH DAYS. SATURDAY...VFR/MVFR WITH AN INCREASE IN SHOWERS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TUESDAY NIGHT/... TONIGHT INTO TOMORROW...MODERATE CONFIDENCE. LEFTOVER SWELL FROM ANA WILL BEGIN TO BUILD ALONG THE S COASTAL WATERS LATE. REACHING A PEAK OF ABOUT 7-9 FT BY THE MID DAY TOMORROW. SMALL CRAFT ADVISORIES CONTINUE FOR THIS THREAT. OTHERWISE...WINDS REMAIN GENERALLY OUT OF THE S-SW UNTIL A COLD FRONTAL PASSAGE TOMORROW LATE IN THE DAY...AT WHICH POINT THEY SHIFT W. THERE IS THE LOW THREAT FOR SOME THUNDERSTORMS...MAINLY ACROSS THE E WATERS LATE IN THE DAY TOMORROW. FOG/STRATUS WILL ONCE AGAIN YIELD NEAR ZERO VSBYS ACROSS THE WATERS TONIGHT INTO TOMORROW. TOMORROW NIGHT...HIGH CONFIDENCE. SLOW IMPROVEMENT AS WINDS SHIFT TO THE W. ANY SHOWERS/STORMS WILL END AND SCOUR OUT THE LEFTOVER FOG. SEAS WILL ALSO GRADUALLY DECLINE SUCH THAT SMALL CRAFT ADVISORIES MAY BE DROPPED BY THE EARLY MORNING HOURS. OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE. WEDNESDAY...LINGERING 5FT SEAS WILL CONTINUE ON WED. HOWEVER GUSTS WILL BE ON THE INCREASE TO 25 KTS ESP ACROSS THE INTERIOR WATERS...SCA WILL BE NEEDED. THURSDAY-FRIDAY...HIGH PRESSURE BUILDS OVER THE WATERS. WINDS AND SEAS WILL BE BELOW SMALL CRAFT CRITERIA. SATURDAY...WARM FRONT WILL PUSH OVER THE WATERS INCREASING PRECIP CHANCES. BUT BOTH WINDS AND SEAS WILL REMAIN BELOW SCA. && .FIRE WEATHER... TOMORROW...TEMPERATURES MAY RISE TO NEAR 90 IN THE LOWER CT VALLEY OF MA AND CT WITH DWPTS HOLDING IN THE 50S AND 60S. THERE IS THE POSSIBILITY THEREFORE...THAT MIN RH VALUES WILL FALL TO AROUND 25-35 PERCENT IN PORTIONS OF SW MA DURING THE DAY. SW WINDS WILL GUST 25-30 MPH AT TIMES BY THE AFTERNOON. ALSO...THERE IS THE THREAT FOR THUNDERSTORMS AND ACCUMULATING RAINFALL...BUT THESE WILL GENERALLY BE HIT OR MISS AND WILL NOT PROVIDE THE WIDESPREAD RAINFALL THAT MUCH OF THE REGION REQUIRES. A FIRE WEATHER WATCH WILL BE ISSUED FOR SW PORTIONS OF MA DUE TO THE COLLOCATION OF DRIEST RH VALUES...HIGHEST WINDS AND LOWEST THREAT FOR RAINFALL. WEDNESDAY...A HIGHER RISK FOR FIRE WEATHER DEVELOPMENT IS EXPECTED ON WEDNESDAY...HOWEVER IT WILL BE DEPENDENT ON PRECIP CHANCES OVER THE NEXT 24-48 HOURS. SECONDARY COLD FRONT WILL PUSH THROUGH WED MORNING ALLOWING FOR WINDS TO BE MORE OUT OF THE NW. THIS WILL ALLOW FOR A DOWNSLOPING EFFECT...WHICH WILL INCREASE THE WIND GUSTS AND LOWER DEWPOINTS. RIGHT NOW BELIEVE THAT RH VALUES WILL DROP TO AROUND 30 PERCENT ACROSS MUCH OF THE REGION WITH NW WINDS GUSTING TO NEAR 30 MPH. ONLY DIFFERENCE COMPARED TO THE PREVIOUS DAYS IS HIGH TEMPS WILL WARM ONLY INTO THE UPPER 60S. HOWEVER APPEARS THAT THERE WILL BE A GOOD AMOUNT OF SUNSHINE ACROSS MOST OF THE REGION. WILL NEED TO CONTINUE TO MONITOR WEDNESDAY FOR POSSIBLE HEADLINES. THURSDAY AND FRIDAY...DRY WEATHER CONDITIONS WILL CONTINUE WITH RH VALUES DROPPING WELL INTO THE 20 PERCENT LEVEL AND WITH FULL SHINE. SINCE HIGH PRESSURE WILL BE OVERHEAD WIND WILL BE LIGHT AND VARIABLE...GUSTS COULD REACH 10-15 MPH. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR MAZ018>024. FIRE WEATHER WATCH FROM NOON EDT TODAY THROUGH THIS EVENING FOR MAZ008>012. RI...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR RIZ005>008. MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ254>256. && $$ SYNOPSIS...DOODY/DUNTEN NEAR TERM...KJC SHORT TERM...DOODY LONG TERM...DUNTEN AVIATION...KJC/DUNTEN MARINE...DOODY/DUNTEN FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS LINCOLN IL
329 AM CDT TUE MAY 12 2015 .SHORT TERM...(TODAY) ISSUED AT 329 AM CDT TUE MAY 12 2015 07Z/2AM SURFACE ANALYSIS SHOWS 1001MB LOW OVER THE NORTHERN GREAT LAKES WHILE A 1025MB HIGH BUILDS INTO THE CENTRAL PLAINS. PRESSURE GRADIENT BETWEEN THESE TWO FEATURES WILL REMAIN TIGHT ENOUGH TO PRODUCE BRISK WESTERLY WINDS ACROSS CENTRAL ILLINOIS TODAY. SUSTAINED WINDS WILL GENERALLY BE IN THE 10 TO 15 MPH RANGE...BUT GUSTS COULD REACH 25 TO 30 MPH AS MIXING TAKES PLACE LATER THIS MORNING. LATEST VWP NETWORK SHOWS 925MB WINDS OF 40 TO 45 MPH AND THINK SOME OF THIS HIGHER MOMENTUM AIR WILL GET MIXED DOWN TO THE SURFACE ONCE MORNING INVERSION IS BROKEN. PRESSURE GRADIENT WILL TEND TO RELAX AS THE DAY PROGRESSES...SO GUSTS WILL BEGIN TO SLOWLY SUBSIDE BY MID-AFTERNOON. LOW CLOUDS CURRENTLY ALONG/NORTH OF A RUSHVILLE TO BLOOMINGTON LINE WILL LIFT NORTHEASTWARD AND CLEAR OUT OF THE AREA BY MID-MORNING...FOLLOWED BY MOSTLY SUNNY SKIES ACROSS THE BOARD FOR THE REMAINDER OF THE DAY. AFTERNOON HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS...WITH READINGS ONLY RISING INTO THE LOWER TO MIDDLE 60S. && .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 329 AM CDT TUE MAY 12 2015 HIGH PRESSURE WILL BUILD EASTWARD INTO THE MIDWEST TONIGHT...WITH THE RIDGE AXIS EXPECTED TO BE POSITIONED RIGHT OVER ILLINOIS BY 12Z WED. CLEAR SKIES AND LIGHT WINDS BENEATH THE RIDGE WILL ALLOW EXCELLENT RADIATIONAL COOLING OF THE DRY AIRMASS TO TAKE PLACE...RESULTING IN OVERNIGHT LOW TEMPERATURES IN THE LOWER TO MIDDLE 40S. MAY EVEN SEE A FEW UPPER 30S IN FAVORED LOW-LYING RURAL AREAS. THE HIGH WILL BEGIN TO SHIFT OFF TO THE EAST ON WEDNESDAY...HOWEVER LOW-LEVEL FLOW WILL MAINTAIN A DISTINCT EASTERLY COMPONENT. AS A RESULT...HIGH TEMPERATURES WILL REMAIN ON THE COOL SIDE IN THE UPPER 60S TO AROUND 70 DEGREES. UPPER HEIGHTS BEGIN TO RISE SIGNIFICANTLY BY THURSDAY AS DEEP UPPER LOW OVER THE GULF OF ALASKA DROPS SOUTHEASTWARD AND REACHES THE CALIFORNIA COAST...RESULTING IN DOWNSTREAM RIDGING ACROSS THE CENTRAL AND EASTERN CONUS. A WEAK DISTURBANCE NOTED ON LATEST WATER VAPOR IMAGERY OFF THE COAST OF SOUTHERN CALIFORNIA WILL GET EJECTED NORTHEASTWARD BY THE DIGGING WEST COAST TROUGH...WITH THIS FEATURE TRACKING INTO THE GREAT LAKES BY FRIDAY. MODELS ARE IN GOOD AGREEMENT WITH THE TRACK AND TIMING OF THIS WAVE...WITH SOME MINOR DISCREPANCIES ON HOW QUICKLY TO SPREAD PRECIP INTO ILLINOIS. GIVEN INITIALLY VERY DRY AIRMASS IN PLACE BENEATH THE SURFACE HIGH...PREFER A SLOWER ARRIVAL OF PRECIP. AS A RESULT...HAVE GONE WITH A DRY FORECAST THROUGH THURSDAY MORNING EAST OF I-55 WITH LOW CHANCE POPS DELAYED UNTIL AFTERNOON. FURTHER WEST...RAIN CHANCES WILL INCREASE TO LIKELY ACROSS THE ILLINOIS RIVER VALLEY BY AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS MUCH OF THE AREA THURSDAY NIGHT...WITH THE BEST RAIN CHANCES FOCUSED NORTH OF THE I-70 CORRIDOR. ONCE THE SHORT-WAVE SHIFTS INTO THE GREAT LAKES...FORCING FOR ADDITIONAL PRECIP BECOMES MUCH WEAKER FRIDAY AND SATURDAY. SEVERAL MODELS ARE HINTING THAT ANOTHER WEAK WAVE EMBEDDED WITHIN THE SOUTHWESTERLY FLOW MAY ENHANCE SHOWERS ACROSS SOUTHERN ILLINOIS INTO THE OHIO RIVER VALLEY...HOWEVER VERY LITTLE FOCUS FOR ORGANIZED CONVECTION EXISTS FURTHER NORTH ACROSS THE REMAINDER OF THE AREA. AS A RESULT...WILL ONLY CARRY LOW CHANCE POPS THROUGH THE PERIOD. DEEP UPPER LOW OVER CALIFORNIA WILL GRADUALLY EJECT NORTHEASTWARD LATE IN THE WEEKEND. MODELS ARE IN GOOD AGREEMENT WITH THIS PROCESS THROUGH 144 HOURS...THEN SOLUTIONS BEGIN TO DIVERGE AFTER THAT. BOTH THE GFS AND ECMWF SHOW THE LOW TRACKING INTO THE DAKOTAS BY SUNDAY EVENING...WITH CONVECTION DEVELOPING ALONG A TRAILING COLD FRONT ACROSS THE PLAINS. THE ECMWF THEN BECOMES MORE PROGRESSIVE WITH THE WAVE...AS IT OPENS UP AND PUSHES EASTWARD INTO THE NORTHERN GREAT LAKES BY MONDAY. MEANWHILE...THE GFS KEEPS THE LOW CLOSED LONGER AND IS THUS SLOWER WITH ITS EASTWARD TRACK. THIS MAKES A BIG DIFFERENCE WITH TIMING OF ASSOCIATED COLD FRONT...AS GFS LINGERS THIS BOUNDARY AND RAIN CHANCES UNTIL TUESDAY. SINCE OVERALL SYNOPTIC PATTERN HAS BEEN PROGRESSIVE OVER THE PAST WEEK AND THE GEM SUPPORTS THE ECMWF...WILL BE GOING WITH THE FASTER ECMWF/GEM SOLUTION IN THE EXTENDED. AS A RESULT...WILL BRING LIKELY POPS INTO THE FAR WESTERN CWA SUNDAY AFTERNOON...THEN FURTHER EAST ACROSS THE REMAINDER OF THE AREA SUNDAY NIGHT. WILL THEN BEGIN TO SHIFT THE RAIN CHANCES OUT OF THE PICTURE ON MONDAY...WITH DRY WEATHER RETURNING MONDAY NIGHT AND TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1154 PM CDT MON MAY 11 2015 VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS. WRAP- AROUND CLOUDS CONTINUE TO MOVE ACROSS THE NORTHERN THIRD OF THE STATE WITH BROKEN TO OVERCAST CLOUDS OCCURRING AT PIA. THESE CLOUDS SHOULD REACH BMI SO WILL HAVE BROKEN TO OVERCAST CLOUDS AT BOTH SITES BUT HAVE A TEMPO GROUP FOR BMI FOR FIRST SEVERAL HOURS OF TAF FOR SCATTERED CLOUDS. OTHER SITES WILL JUST SEE SCATTERED CLOUDS OVERNIGHT AND THROUGH MOST OF THE DAY. HRRR MODEL SHOWS THE POSSIBILITY OF SOME BROKEN CIGS REACHING CMI IN THE MORNING SO WILL HAVE TEMPO GROUP TO COVER THAT IN THE MORNING. ALL SITES WILL EITHER REMAIN SCATTERED OR SCATTER OUT DURING THE MORNING HOURS AND THEN BECOME CLEAR LATE MORNING TO EVENING HOURS. WEST WINDS WILL CONTINUE AND THEN BECOME NORTHWEST TOMORROW EVENING. GUSTY WINDS ARE EXPECTED AGAIN TOMORROW. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BARNES LONG TERM...BARNES AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1154 PM CDT MON MAY 11 2015 .UPDATE... ISSUED AT 904 PM CDT MON MAY 11 2015 WRAP-AROUND CLOUDS CONTINUE TO SLOWLY MAKE THEIR WAY INTO THE AREA THIS EVENING WITH THE THICKEST CLOUDS BEING ACROSS THE NORTHERN THIRD OF THE CWA. STILL COULD GET SOME CLOUDS ACROSS THE I-72 CORRIDOR, BUT SHOULD REMAIN PARTLY CLOUDY OVERNIGHT. REMAINDER OF THE FORECAST LOOKS FINE WITH LOWS IN THE MID 40S TO LOWER 50S. WINDS SHOULD STAY UP A TAD AS WELL WITH GUSTS STILL SHOWING UP AT SOME SITES. WILL MAKE SOME ADJUSTMENTS TO CLOUD COVER AND WINDS IN THE GRIDS. WILL SEND AN UPDATE SHORTLY, THOUGH THERE WILL PROBABLY NOT BE MUCH CHANGE IN THE WORDED FORECAST. && .SHORT TERM...(TONIGHT) ISSUED AT 255 PM CDT MON MAY 11 2015 A COLD FRONT DELINEATED BY A THIN LINE OF SHOWERS EXTENDED FROM JUST WEST OF CHICAGO TO JUST EAST OF BLOOMINGTON AND TAYLORVILLE. THIS FRONT WILL PUSH EAST TO THE IL/IN BORDER BY 00Z/7 PM WITH ISOLATED SHOWERS POSSIBLE ALONG AND AHEAD OF IT THE REST OF THE EASTERN IN EASTERN IL. ISOLATED THUNDERSTORMS SHOULD MOSTLY STAY EAST OF CENTRAL IL OVER INDIANA REST OF TODAY WHILE SEVERE STORMS STAY OVER OHIO AND EASTERN PARTS OF IN/KY INTO EARLY EVENING. OTHERWISE DRY CONDITIONS EXPECTED TONIGHT INTO TUE ACROSS CENTRAL AND SOUTHEAST IL ALONG WITH BREEZY AND COOLER CONDITIONS. LOW CLOUDS WERE DECREASING BEHIND THE COLD FRONT WEST OF I-55 AT MID AFTERNOON AND EXPECT THESE CLOUDS TO CONTINUE TO DECREASE OVER EASTERN IL LATE THIS AFTERNOON AND EARLY EVENING. ANOTHER AREA OF LOW CLOUDS OVER IA AND NW MO WAS TRACKING EASTWARD AND WILL SKIRT ACROSS THE IL RIVER VALLEY BY THIS EVENING SO HAVE MORE CLOUDS OVER NORTHERN/NW COUNTIES TONIGHT. THE SOUTHERN/SE EDGE OF THESE CLOUDS IS DIURNALLY ENHANCED SO MAY SEE THIS DISSIPATE AFTER SUNSET. 1003 MB SURFACE LOW PRESSURE OVER CENTRAL MN WILL TRACK EASTWARD ACROSS NORTHERN MI OVERNIGHT AND FAIRLY TIGHT PRESSURE GRADIENT TO REMAIN OVER CENTRAL IL INTO TUE. SW WINDS OF 15 TO 25 MPH AND GUSTS OF 25 TO 30 MPH THIS AFTERNOON TO SHIFT MORE WESTERLY DURING THE NIGHT AND DIMINISH TO 10-17 MPH AFTER SUNSET WITH GUSTS 18-25 MPH THIS EVENING. .LONG TERM...(TUESDAY THROUGH MONDAY) ISSUED AT 255 PM CDT MON MAY 11 2015 A COUPLE COOLER DAYS, ALTHOUGH NOT AS COOL AS ANTICIPATED A FEW DAYS AGO, ARE EXPECTED TUESDAY AND WEDNESDAY. A SPRAWLING SURFACE HIGH WILL BUILD ACROSS THE AREA DURING THE PERIOD, WITH THE UPPER LEVEL FLOW QUICKLY TRANSITIONING FROM WEAK TROFFING TO A BUILDING RIDGE. THIS SCENARIO IS ALSO SUPPORTIVE OF DRY WEATHER CONDITIONS. HOWEVER, CONDITIONS FLIP RATHER QUICKLY BACK TO WARM AND UNSETTLED AFTER THE MIDDLE OF THE WEEK. A SYSTEM CURRENTLY DIVING DOWN THE WEST COAST WILL CARVE OUT A NEW WESTERN U.S. TROF, WHICH WILL HELP DEVELOP A DOWNSTREAM EASTERN U.S. RIDGE. DISTURBANCES EJECTING OUT OF THIS TROF WILL CAUSE PERIODIC SHOWERS/STORMS ACROSS CENTRAL AND SOUTHEAST ILLINOIS FOR THE END OF THE WEEK AND THE WEEKEND, MUCH AS WAS SEEN THIS PAST WEEKEND. TEMPERATURES SHOULD ALSO TREND WELL ABOVE NORMAL, WITH DAYTIME HIGHS HEADING BACK TOWARD THE 80S BY THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1154 PM CDT MON MAY 11 2015 VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS. WRAP- AROUND CLOUDS CONTINUE TO MOVE ACROSS THE NORTHERN THIRD OF THE STATE WITH BROKEN TO OVERCAST CLOUDS OCCURRING AT PIA. THESE CLOUDS SHOULD REACH BMI SO WILL HAVE BROKEN TO OVERCAST CLOUDS AT BOTH SITES BUT HAVE A TEMPO GROUP FOR BMI FOR FIRST SEVERAL HOURS OF TAF FOR SCATTERED CLOUDS. OTHER SITES WILL JUST SEE SCATTERED CLOUDS OVERNIGHT AND THROUGH MOST OF THE DAY. HRRR MODEL SHOWS THE POSSIBILITY OF SOME BROKEN CIGS REACHING CMI IN THE MORNING SO WILL HAVE TEMPO GROUP TO COVER THAT IN THE MORNING. ALL SITES WILL EITHER REMAIN SCATTERED OR SCATTER OUT DURING THE MORNING HOURS AND THEN BECOME CLEAR LATE MORNING TO EVENING HOURS. WEST WINDS WILL CONTINUE AND THEN BECOME NORTHWEST TOMORROW EVENING. GUSTY WINDS ARE EXPECTED AGAIN TOMORROW. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AUTEN SHORT TERM...07 LONG TERM...BAK AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
400 AM EDT TUE MAY 12 2015 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA LATE TODAY. HIGH PRESSURE RETURNS WEDNESDAY AND THURSDAY...THEN PUSHES OFFSHORE ON FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... THE REMNANTS OF ANA HAVE PUSHED WELL OFF THE MID-ATLANTIC COAST THIS MORNING. THE NEXT FEATURE TO IMPACT THE LOCAL AREA IS A COLD FRONT CURRENTLY MAKING ITS WAY THROUGH THE OH VALLEY...AND STRETCHING SOUTHWARD TO THE LOWER MS VALLEY. WARM/HUMID SW FLOW IN PLACE THIS MORNING IS MAKING IT FEEL MORE LIKE MID-SUMMER WITH TEMPS GENERALLY IN THE MID 60S TO MID 70S AT THIS HOUR. THE CURRENT RADAR SCANS SHOWS THAT THE CONVECTION FROM LAST EVENING HAS WANED. HOWEVER...A NEW ROUND OF SHWR ACTIVITY STRETCHING FROM NEAR LYNCHBURG TO MARTINSVILLE IS POISED TO MAKE A RUN AT OUR EASTERN PIEDMONT COUNTIES BY AROUND DAYBREAK. WILL CARRY SLIGHT CHC POPS WESTERN AREAS THRU AROUND 9 AM TO ACCOUNT FOR THIS POSSIBILITY. LATEST HRRR APPEARS A BIT ROBUST WITH PCPN MAKING IT ALL THE WAY TO RICHMOND...BUT DOES SUPPORT THE AFOREMENTIONED SLIGHT CHC POPS. THE COLD FRONT CONTINUES TO MOVE EAST THROUGH THE DAY...REACHING EASTERN PORTIONS OF THE FA AROUND 00Z. AHEAD OF THE FRONT...MODELS ARE IN GOOD AGREEMENT SHOWING A PRE-FRONTAL TROUGH SHARPENING ACROSS THE PIEDMONT BY 18Z WITH DEEP LAYERED WSW FLOW BRINGING DRIER AIR (AND SIGNIFICANT LOWERING OF DEW POINTS) INTO THE REGION. THE BEST MOISTURE AHEAD OF THE APPROACHING COLD FRONT IS SHOWN TO QUICKLY SHIFT EAST INTO EASTERN AREAS THIS AFTN/EVE... ESPECIALLY SE VA AND NE NC. MODEL SOUNDINGS SHOW A STRONG CAP DEVELOPING BETWEEN 6-8KFT DURING THE AFTN HOURS ALONG AND NW OF A LINE FROM AVC-PTB-WAL...WHICH WILL INHIBIT CONVECTION. SLOWER DEEP LAYERED DRYING AND A WEAKER CAP IN SE VA/NE NC DURING THE AFTN/EARLY EVE MAY RESULT IN POSSIBLE ISOLD/SCT CONVECTION AT TIME OF PEAK HEATING. POPS WERE ADJUSTED ACCORDINGLY TO REFLECT A 30% POP FROM ABOUT THE TRI-CITIES ON SOUTHEAST THIS AFTN/EVE. SPC HAS SE VA/NE NC ONLY IN A MARGINAL RISK OF SVR WX LATER TODAY...AS THERE MAY BE JUST ENOUGH INSTABILITY/MOISTURE IN PLACE (ML CAPE 1000-1500 J/KG) COUPLED WITH MODEST SHEAR 20-30 KT TO PRODUCE AN ISOLD DAMAGING WIND GUST THREAT. OTW...TODAY WILL BE SUMMER-LIKE WITH HIGH TEMPS IN THE MID-UPR 80S ALONG THE IMMEDIATE COAST...UPR 80S-LOW 90S ELSEWHERE. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... SUBSTANTIAL DRYING TONIGHT THROUGH WED AS FLOW ALOFT BECOMES NW AND SFC HIGH PRESSURE BUILDS TWD THE FA FROM THE GREAT LAKES. LOW TEMPS TONIGHT FROM THE MID-UPR 50S...EXCEPT LOW 60S SE. SUNNY AND LESS HUMID WED AS SFC HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION FROM THE NW. HIGH TEMPS RANGING FROM THE MID 60S-LOW 70S ALONG THE COAST...MID-UPR 70S INLAND. DRY/PLEASANT WX WED NIGHT/THU W/ LGT/VRB WINDS AND CLEAR-PTCLDY SKY. LOW TEMPS WED NIGHT FROM THE MID-UPR 40S INLAND TO THE MID 50S AT THE COAST. HIGH TEMPS THU 65 TO 70F AT THE BEACHES TO THE LOW-MID 70S INLAND. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... HIGH PRESSURE RESIDES OVER THE AREA FOR ONE MORE NIGHT...KEEPING LOW TEMPERATURES IN THE LOWER 50S INLAND AND MID-UPPER 50S AT THE IMMEDIATE COAST. HIGH PRESSURE THEN SLIDES OFF THE COAST DURING THE DAY ON FRIDAY...ALLOWING WARM AIR ADVECTION PROCESSES TO COMMENCE IN RETURN SWLY FLOW. GULF MOISTURE WILL GRADUALLY BE PULLED INTO THE REGION AROUND THE BACK SIDE OF A LARGE-SCALE HIGH PRESSURE OVER THE SOUTHEAST COAST...THUS INTRODUCING PRECIPITATION BACK INTO THE FORECAST BEGINNING FRIDAY AFTERNOON. UNSETTLE CONDITIONS THEN PREVAIL THROUGH THE UPCOMING WEEKEND AND INTO EARLY NEXT WEEK WITH NO SIGNIFICANT UPSTREAM FEATURES TO PUSH THE HIGH SOUTH OR EAST. EXPECT PERIODS OF OFF AND ON RAIN SHOWERS/AFTN THUNDERSTORMS (30-40 PERCENT) DURING THIS TIMEFRAME. HIGHS SLOWLY REBOUND TO SLIGHTLY ABOVE SEASONAL NORMALS THROUGH THE WEEKEND AS THE SFC HIGH MOVES OFFSHORE. EXPECT HIGHS 75-85 (5-7 DEGREES COOLER AT THE IMMEDIATE COAST) AND LOWS IN THE LOW-MID 60S. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... THE REMNANT LOW FROM ANA IS NOW IN VICINITY OF THE CENTRAL NJ COAST AS OF 06Z...AND IS IN THE PROCESS OF BECOMING ABSORBED BY LOW PRESSURE OVER THE GREAT LAKES. A COLD FRONT ASSOCIATED WITH THE GREAT LAKES LOW IS BACK OVER THE OHIO VALLEY. THE LOCAL AREA IS NOW WITHIN A REGION OF SW FLOW AHEAD OF THE COLD FRONT. BKN CIGS AOA 6KFT COMBINED WITH A 6-10KT SW WIND SHOULD INHIBIT FOG DEVELOPMENT OVERNIGHT. THE BEST CHC FOR MVFR VSBY IS AT SBY WHERE THE DEWPOINT DEPRESSION IS 2F...MEANWHILE OTHER LOCATIONS ARE 8-10F. ISOLATED -SHRA/TSRA WILL LINGER OVERNIGHT...BUT THE PROBABILITY OF A DIRECTLY AFFECTING A TAF SITE IS VERY LOW. OTHERWISE...EXPECT BREEZY CONDITIONS TO DEVELOP LATER THIS MORNING AHEAD OF THE COLD FRONT WITH A SW WIND AVERAGING 12-15KT...WITH GUSTS OF 20-25KT THROUGH THE AFTERNOON. A FEW -SHRA/TSRA ARE POSSIBLE THIS AFTERNOON MAINLY OVER SE VA/NE NC. THE COLD FRONT SWEEPS THROUGH THE AREA THIS EVENING...WITH HIGH PRESSURE PREVAILING MIDWEEK. HIGH PRESSURE MOVES OFFSHORE FRIDAY AND SATURDAY. && .MARINE... THE REMNANT LOW OF ANA ABSORBS INTO LOW PRESSURE TRACKING ACROSS THE SAINT LAWRENCE VALLEY TODAY. THIS WILL DRAG A COLD FRONT TOWARD THE REGION TODAY...WITH THE BOUNDARY CROSSING THE COAST THIS EVENING. EXPECT A SW WIND TO AVERAGE ~15KT OVER THE BAY EARLY TODAY WITH 15- 20KT OVER THE OCEAN...BEFORE RELAXING TO 10-15KT THIS AFTERNOON. A SHORT DURATION PERIOD OF ~20KT IS POSSIBLE ACROSS THE LOWER BAY/LOWER JAMES AROUND 10-12Z BUT SHOULD NOT BE LONG ENOUGH TO WARRANT AN SCA. ADDITIONALLY...A FEW TSTMS ARE POSSIBLE WITH THE FRONTAL PASSAGE THIS AFTERNOON AND EVENING. MODEST CAA ARRIVES LATER TONIGHT INTO EARLY WEDNESDAY...ESPECIALLY ACROSS THE NRN HALF OF THE AREA IN THE WAKE OF THE FRONT. AN SCA HAS BEEN ISSUED FOR THE BAY FOR LATE TONIGHT INTO WEDNESDAY MORNING. THE SCA N OF PARRAMORE ISLAND HAS BEEN EXTENDED THROUGH TODAY AS SEAS COULD LINGER ~5FT (ESPECIALLY OUT NEAR 20NM)...AND CONTINUING TONIGHT INTO WEDNESDAY MORNING FOR THE CAA SURGE. A SECONDARY NORTHERLY SURGE WEDNESDAY NIGHT HAS THE POTENTIAL TO PRODUCE MARGINAL SCA CONDITIONS...BEFORE HIGH PRESSURE SETTLES INTO THE REGION THURSDAY AND THURSDAY NIGHT. HIGH PRESSURE MOVES OFFSHORE FRIDAY AND SATURDAY ALLOWING THE WIND TO RETURN TO SSW. SEAS SHOULD AVERAGE 2-4FT LATER WEDNESDAY THROUGH SATURDAY...WITH WAVES IN THE BAY AVERAGING 1-3FT. && .CLIMATE... RATHER HOT TUE...WITH A GOOD CHANCE AT SEEING OUR 1ST 90- DEGREE DAY OF THE YEAR: MEAN DATE OF 1ST 90-DEGREE DAY (1981-2010 CLIMATOLOGY): RICHMOND....MAY 13TH NORFOLK.....MAY 17TH SALISBURY...MAY 27TH ELIZ CITY...MAY 25TH RECORD HIGHS POSSIBLE TUE...RECORDS ARE LISTED BELOW FOR MAY 12TH: RICHMOND....92 (1956) NORFOLK.....92 (1881) SALISBURY...93 (1914) ELIZ CITY...90 (2001) && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ650- 652-654. && $$ SYNOPSIS...JDM NEAR TERM...JDM SHORT TERM...ALB/JDM LONG TERM...BMD AVIATION...AJZ MARINE...AJZ CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
139 AM EDT TUE MAY 12 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 421 PM EDT MON MAY 11 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE MID LEVEL LOW THAT WAS OVER WRN NEBRASKA/SD 24HRS AGO NOW CENTERED IN WCNTRL MN. AHEAD OF FEATURE...WARM CONVEYOR BELT MOISTURE RIBBON EXTENDS FROM THE LWR MISSISSIPPI VALLEY TO THE WRN GREAT LAKES. RESULT HAS BEEN NMRS SHRA SPREADING ACROSS THE FCST AREA TODAY. A FEW TSTMS WERE NOTED THIS MORNING OVER THE W HALF OF UPPER MI. AT THE SFC...LOW PRES LOCATED IN CNTRL MN IS BECOMING LESS WELL-DEFINED WITH TENDENCY FOR LOW PRES REDEVELOPMENT AT THE TRIPLE POINT FARTHER E. OCCLUDED FRONT IS APPROACHING THE MI/WI BORDER AS OF 20Z. AS THE WARM CONVEYOR MOISTURE RIBBON TRANSLATES E...WIDESPREAD SHRA NOW OVER THE E HALF OF THE FCST AREA WILL ALSO SHIFT E AND OUT OF THE AREA IN THE NEXT FEW HRS. FOG AND SOME -DZ WILL PERSIST IN THE UPSLOPE FLOW OFF LAKE SUPERIOR INTO THE KEWEENAW AND WRN PORTIONS OF NCNTRL UPPER MI...AND A FEW SHRA MAY DEVELOP NEAR THE OCCLUDED FRONT WHICH SHOULD LIFT INTO OR THRU MUCH OF CNTRL AND ERN UPPER MI THIS EVENING. OTHERWISE...AS MID LEVEL LOW OPENS UP AND UPPER TROF MOVES E INTO THE WRN GREAT LAKES TONIGHT...DEEPER MOISTURE WILL WRAP BACK INTO THE AREA FROM THE N AND W. AIDED BY DEEP CYCLONIC FLOW...SHRA WILL SPREAD BACK INTO THE FCST AREA...ESPECIALLY ACROSS THE W. AS CAA INCREASES OVERNIGHT...FCST SOUNDINGS/WETBULB ZERO HEIGHTS SUGGEST POTENTIAL FOR SNOW TO MIX WITH THE RAIN OVER THE HIGH TERRAIN OF THE W LATE TONIGHT. AS TROF CONTINUES TO SHIFT E TUE...DEEP LAYER QVECTOR DIVERGENCE OVERSPREADS THE AREA WITH HEIGHTS BEGINNING TO RISE...MORE SUBSTANTIALLY IN THE AFTN. THIS WILL TEND TO DIMINISH THE WRAP AROUND PCPN WITH TIME...BUT THIS WILL BE COUNTERACTED BY SHARP CYCLONIC FLOW AND CONSIDERABLE LOW TO MID LEVEL MOISTURE THAT LINGERS THRU THE DAY. THIS WILL RESULT IN PCPN BEING MOST PERSISTENT IN THE AREAS THAT SEE UPSLOPING UNDER NW TO N WINDS. DOWNSLOPE AREAS WILL SEE PCPN DIMINISH OR END. CONTINUED CAA WILL DROP 850MB TEMPS TO -3 TO AS LOW AS -6C...AND THIS WILL RESULT IN RAIN MIXING WITH SNOW...MAINLY OVER THE HIGHER TERRAIN OF THE W AND CNTRL. PCPN WILL LIKELY CHANGE TO ALL SNOW AT LEAST FOR A TIME OVER THE HIGH TERRAIN OF THE W HALF AS LOWEST 850MB TEMPS ARE FCST THERE. THAT AREA WILL ALSO HAVE THE BEST CHANCE FOR A LITTLE SNOW ACCUMULATION ON GRASSY SFCS. IT WILL BE AN UNSEASONABLY COLD DAY WITH TEMPS AROUND 20 DEGREES BLO NORMAL ACROSS THE W AND N WHERE TEMPS WILL STRUGGLE TO GET MUCH ABOVE 40F. ACROSS THE SCNTRL...TEMPS MAY SNEAK INTO THE LWR 50S. BLUSTERY WINDS WILL ADD TO THE CHILL. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 255 PM EDT MON MAY 11 2015 WILL STILL HAVE SOME LINGERING MAINLY SNOW SHOWERS /WITH A FEW RAIN SHOWERS OR AREAS OF DRIZZLE MIXED IN/ TUESDAY NIGHT OVER THE N HALF OF UPPER MI. THE BEST CHANCE OF PRECIP WILL BE N CENTRAL AS FAVORABLE N-NNW WINDS RESIDE THERE FROM THE SFC-850MB. TEMPERATURES WILL BE COOLING INTO THE LOW 30S OVERNIGHT...WITH LOCATIONS OVER THE INTERIOR W HALF FALLING INTO THE MID 20S AS WINDS BECOME NEARLY CALM AND DRIER AIR WORKS IN AND 850MB TEMPS BEGIN TO WARM SLIGHTLY FROM - 4 TO -6C...TO AROUND -3C. HIGH PRESSURE WILL BE STRETCHING FROM HUDSON BAY THROUGH MANITOBA AND MN...DOWN THROUGH THE MS VALLEY AT 00Z WEDNESDAY. LOOK FOR THE AREA OF HIGH PRESSURE TO BUILD ACROSS THE UPPER GREAT LAKES THROUGH WEDNESDAY...WITH DRY WEATHER FIGURED INTO AT LEAST WEDNESDAY EVENING. WAA WILL TAKE HOLD AT THE SFC ON MAINLY S WINDS OVER THE W HALF OF THE CWA...WITH AFTERNOON HIGHS IN THE 50S FOR MOST LOCATIONS /EXCLUDING THE COOLER N CENTRAL AND E LAKE SUPERIOR SHORELINE/ AS 850MB TEMPS REBOUND TO AROUND 4C W TO 1C E. PRECIP COULD SLIDE IN AS EARLY AS LATE WEDNESDAY AFTERNOON SW /GFS SOLUTION/. THIS WOULD BE ALONG THE SW AS AN INITIAL FRONTAL BOUNDARY SHIFTS TO OUR N. THE MAIN CONCERN IS THAT THE LOWER LEVELS WILL BE TOO DRY WITH THE SFC RIDGE STILL OVER MUCH OF THE AREA WITH THIS BOUNDARY/SHORTWAVE ROUNDING THE 500MB RIDGE. WILL CONTINUE TO GO WITH A MINIMAL PRECIP SOLUTION FOR THIS PERIOD. THE SFC HIGH WILL SHIFT ACROSS THE ENTIRE GREAT LAKES REGION WEDNESDAY NIGHT...WITH SLOWLY INCREASING S FLOW OVER UPPER MI PUSHING IN INCREASED MOISTURE AS 850MB TEMPS RUMP TO AROUND 8C OVER THE SW. THE APEX OF THE 500MB RIDGE WILL BE ACROSS THE AREA THURSDAY AFTERNOON...WITH FCST MODELS INDICATING A NEARING EMBEDDED 500MB TROUGH IN THE SW FLOW OVER THE N PLAINS AND W MN. THE GFS HAS A DEEPER/WRAPPED UP SFC LOW OVER THE CENTRAL PLAINS OFF THE GFS IS NOT QUITE A S STRONG AS THE ECMWF...ESPECIALLY THE PREVIOUS 11/06Z RUN. THIS LEADS TO ONLY MODERATE CONFIDENCE IN THE FCST BEYOND THURSDAY. THE DIFFERENCE SHOWS UP WELL IN THE MODEL QPF...WITH THE 11/06Z GFS SHOWING 24HR PRECIP OF 0.75-1.45IN BY 00Z SATURDAY. THE 11/00Z ECMWF ON THE OTHER HAND RANGES FROM LESS THAN 0.10IN ACROSS THE KEWEENAW PENINSULA...TO 0.5IN OVER FAR S MENOMINEE CO. THIS WILL BE AS THE SFC LOW OFF THE GFS TRACKS FROM THE CENTRAL PLAINS TO N LAKE MI BY 00Z SATURDAY. THE CANADIAN THE ECMWF KEEP A RIDGE ACROSS LAKE SUPERIOR AND MUCH OF UPPER MI DURING THE SAME TIME PERIOD. ON A POSITIVE NOTE...THE 11/12Z GFS CAME IN AT LEAST A LITTLE LESS INTENSE WITH THE SFC LOW...AND DROPS ABOUT 1/2 AS MUCH PRECIP. AN ADDITIONAL LOW DEVELOPING OFF THE N ROCKIES TOWARDS THE END OF THE WORK WEEK WILL LIKELY BE SET UP ACROSS MT AND WY SATURDAY MORNING...AND MOVE ACROSS THE DAKOTAS SATURDAY NIGHT...AND THE UPPER GREAT LAKES ON MONDAY. THE 12Z RUNS HAVE BECOME MUCH MORE IN LINE WITH THE SFC LOW TRACKING OVER E MN/FAR W LAKE SUPERIOR BY 06Z MONDAY. THE RESULT IS AT LEAST MODERATE CONFIDENCE IN RAIN. WILL GO WITH LIKELY PRECIP FOR SUNDAY NIGHT ACROSS MOST OF THE CWA. SO FOR THE UPCOMING WEEKEND IT LOOKS TO BE MAINLY DRY SATURDAY...WITH WET WEATHER APPROACHING SUNDAY AND POSSIBLY LINGERING INTO MONDAY AS THE SFC LOW SLOWLY EDGES E OF THE CWA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 138 AM EDT TUE MAY 12 2015 A LOW PRES SYSTEM WILL MOVE E ACROSS THE UPPER GREAT LAKES TONIGHT AND THEN E TO QUEBEC TUE. ABUNDANT LOW-LEVEL MOISTURE WILL GENERALLY SUPPORT IFR TO LIFR CONDITIONS OVERNIGHT TONIGHT AND -SHRA AT KIWD/KCMX/KSAW TONIGHT WITH THE LOWEST CONDITIONS OCCURRING AT TERMINALS EXPERIENCING UPSLOPE WINDS. COLDER AIR WRAPPING INTO THE AREA BEHIND THE LOW SHOULD BE COLD ENOUGH TO RESULT IN -SHRA MIXING WITH OR CHANGING OVER TO -SHSN LATE TONIGHT/TUE MORNING. CHANGE OVER TO ALL SNOW IS MORE LIKELY TO OCCUR AT KIWD/KCMX. DRIER AIR WORKING IN BEHIND THE LOW LATE TUE AFTERNOON INTO TUE EVENING WILL END PCPN AND ALLOW ALL THE TAF SITES TO IMPROVE TO MVFR BY TUE EVENING. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 421 PM EDT MON MAY 11 2015 ONGOING MARGINAL GALES OVER THE WRN PORTION OF LAKE SUPERIOR WILL CONTINUE TO DIMINISH...FALLING BLO GALE FORCE EARLY THIS EVENING... AS PRES GRADIENT WEAKENS AND WINDS BACK DUE TO LOW PRES SHIFTING ACROSS UPPER MI AND ERN LAKE SUPERIOR. ON THE BACK SIDE OF THE LOW...NNW WINDS WILL INCREASE TO 20-30KT ACROSS CNTRL AND ERN LAKE SUPERIOR LATE TONIGHT/TUE MORNING. MAY SEE A FEW GALE FORCE GUSTS TUE MORNING OVER SCNTRL LAKE SUPERIOR AROUND GRANITE ISLAND DUE TO LOCAL COASTAL CONVERGENCE. WINDS WILL DIMINISH FROM W TO E TUE AFTN/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS E AND A WEAK LOW PRES PASSES BY TO THE S...WINDS MAY INCREASE SOME FOR THU NIGHT/FRI BEFORE DIMINISHING AGAIN ON SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1210 AM EDT TUE MAY 12 2015 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 328 PM EDT MON MAY 11 2015 A COLD FRONT WILL COME THROUGH THE AREA TONIGHT ENDING OVER A WEEKS WORTH OF UNSEASONABLY WARM TEMPERATURES. THERE WILL BE SHOWERS AND A FEW THUNDERSTORMS AHEAD OF THE COLD FRONT THIS EVENING...THEN A FEW LIGHT RAIN SHOWERS TUESDAY AS CHILLY WESTERLY WINDS KEEP AFTERNOON TEMPERATURES IN THE 50S. SKIES WILL BECOME PARTLY CLOUDY TUESDAY NIGHT REMAIN SO ON WEDNESDAY. ANOTHER STORM SYSTEM WILL BRING MORE SHOWERS AND POSSIBLY THUNDERSTORMS LATER THIS WEEK INTO THE WEEKEND. IT WILL WARM UP AGAIN BY THE END TOO. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 328 PM EDT MON MAY 11 2015 THE MAIN ISSUE IS THE THREAT FOR SEVERE STORMS (NOT MUCH) THEN THE CHANCE FOR LIGHT RAIN SHOWERS TUESDAY AND POSSIBLE FROST TOMORROW NIGHT. THE LATEST RAP MODEL SHOWS THE LOW LEVEL JET CORE LIFTING NORTHEAST FROM SOUTHWEST LOWER MICHIGAN EARLY THIS AFTERNOON TO THE THUMB AREA BY EARLY THIS EVENING. THE MOST UNSTABLE CAPE (OVER 500 J/KG) STAYS JUST EAST OF OUR CWA LATE THIS AFTERNOON. WHILE THERE IS GOOD DEEP LAYER SHEAR...THE RAIN COOLED AIR OVER MOST OF OUR CWA WILL MITIGATE MOST OF THE SEVERE WEATHER THREAT. POSSIBLY ISOLATED DAMAGING WINDS COULD HAPPEN OVER OUR EXTREME SOUTHEAST COUNTIES EARLY THIS EVENING. OTHERWISE THE AREA OF RAIN WILL MOVE OUT BY MID EVENING. THEN THE DRY SLOT MOVES IN BEHIND THE COLD FRONT SO SKIES WILL CLEAR AT LEAST PARTLY. WE THEN GET WRAP AROUND COLD AIR ADVECTION INSTABILITY SHOWERS (MOSTLY SPRINKLES) TUESDAY AND IT WILL BE BREEZY AND CHILLY WITH HIGHS ONLY IN THE 50S. THE UPPER TROUGH MOVES OUT QUICKLY TUESDAY NIGHT ALLOWING FOR SOME CLEARING. FROST IS POSSIBLE OVER NORTHERN AREAS WEDNESDAY MORNING. .LONG TERM...(THURSDAY THROUGH MONDAY) ISSUED AT 328 PM EDT MON MAY 11 2015 AS HIGH PRESSURE MOVES EAST THURSDAY LOW PRESSURE WILL MOVE TOWARD THE GREAT LAKES. CONFIDENCE IS INCREASING THAT WE/LL SEE SOME PRECIPITATION MOVE OVER THE CWA THURSDAY NIGHT AND FRIDAY. ADDED THUNDER TO THE GRIDS FRIDAY AS LI/S FALL TO AROUND -2C AND CAPE INCREASES TO 1K J/KG. MUCH OF THE PCPN WILL BE EAST OF THE CWA BY SATURDAY AS THE SFC LOW MOVES AWAY. HOWEVER WE/LL KEEP LOW POPS IN TO COVER THE UPPER TROUGH. CHANCES FOR TSRA WILL INCREASE TOWARD THE BEGINNING OF NEXT WEEK AS A STRONGER COLD FRONT MOVES TOWARD THE CWA. STRONG SOUTH FLOW AHEAD OF IT WILL SEND ABUNDANT MOISTURE NORTHWARD AND CREATE SOME INSTABILITY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1209 AM EDT TUE MAY 12 2015 PREDOMINATELY VFR OVERNIGHT BUT AROUND 12Z TUESDAY MVFR CIGS WILL SPREAD IN FROM THE WEST AND PERSIST MUCH OF THE DAY. A FEW LIGHT SHOWERS OR SPRINKLES ARE POSSIBLE BUT IF ANY REDUCTIONS TO VSBYS OCCURRED IT SHOULD BE VERY BRIEF. CIGS ARE EXPECTED TO IMPROVE TO VFR AGAIN TUESDAY NIGHT AFTER 00-02Z. GUSTY SOUTHWEST TO WEST SFC WINDS OF 15 TO 25 KNOTS TONIGHT WILL INCREASE TO 20 TO 30 KNOTS ON TUESDAY... RESULTING IN SOME LOW LEVEL TURBULENCE. WINDS WILL DECREASE TUESDAY NIGHT AFTER 00-02Z. && .MARINE... ISSUED AT 328 PM EDT MON MAY 11 2015 THE STRONG WINDS BEHIND OUR SYSTEM WILL LEAD TO 4 TO 6 FOOT WAVES AND WINDS TO 30 KNOTS BY MID MORNING TUESDAY. AS A RESULT I ISSUED A SMALL CRAFT ADVISORY. && .HYDROLOGY... ISSUED AT 1222 PM EDT MON MAY 11 2015 ADDITIONAL RAINFALL AMOUNTS BETWEEN A QUARTER AND THREE QUARTERS OF AN INCH WILL BE POSSIBLE MAINLY BEFORE MIDNIGHT TONIGHT. WE ARE ISSUING ADVISORIES FOR THE SYCAMORE CREEK AT HOLT...WHICH SHOULD CREST SHORTLY AFTER MIDNIGHT TONIGHT. CONFIDENCE IS HIGH THAT IT WILL REMAIN BELOW FLOOD STAGE. AFTER TONIGHT DRY CONDITIONS SHOULD PREVAIL UNTIL THURSDAY...WHEN RAIN SHOWERS RETURN TO THE AREA. THIS SHOULD GIVE RIVER LEVELS SOME TIME TO SUBSIDE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 6 PM EDT THIS EVENING FOR LMZ844>849. && $$ SYNOPSIS...WDM SHORT TERM...WDM LONG TERM...93 AVIATION...MEADE HYDROLOGY...TJT MARINE...WDM
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1237 AM CDT TUE MAY 12 2015 .UPDATE... ISSUED AT 734 PM CDT MON MAY 11 2015 UPDATED POPS AS CURRENT RADAR TRENDS SHOW PRECIPITATION INCREASING IN COVERAGE AND INTENSITY ACROSS THE FORECAST AREA. AN AREA OF CONVECTIVE SHOWERS WITH REFLECTIVITY VALUES OVER 40 DBZ HAS DEVELOPED ABOUT 30 MILES NORTH OF DULUTH...ON THE LEADING EDGE OF THE H50 LOW/VORT MAX AND AN REGION OF LOW LEVEL FRONTOGENESIS DEPICTED IN THE LATEST RUC MESO ANALYSIS. ANTICIPATE ECHOES TO CONTINUE TO INTENSIFY OVER THE IRON RANGE/ARROWHEAD AS THE VORT MAX TRANSLATES EAST ACROSS THE FORECAST AREA. AT THIS TIME THE PRECIP TYPE BEING REPORTED BY AUTOMATED STATIONS IS ALL RAIN. HOWEVER...AS PROFILES COOL THROUGH THE EVENING THE RAIN IS EXPECTED TO CHANGE OVER TO SNOW FOR AT LEAST THE NORTHERN PORTION OF MN. ALSO ADDED AREAS OF FOG ALONG SOUTH SHORE OF LAKE SUPERIOR WHERE SURFACE OBSERVATIONS AND SPOTTERS HAVE REPORTED VISIBILITY OF LESS THAN A HALF MILE AT TIMES. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 328 PM CDT MON MAY 11 2015 A CLOSED AND NEARLY STACKED UPPER LOW OVER MINNESOTA WILL CONTINUE SHOWERS OVER THE REGION TONIGHT AS IT SLOWLY MOVES EAST. THE STRONGEST LIFT NORTH OF THE BAROCLINIC ZONE WILL BE IN NORTHERN MINNESOTA BUT CANNOT RULE OUT SHOWERS ACROSS REST OF THE FORECAST AREA. COLD AIR ADVECTION BEHIND THE LOW LATER TONIGHT COULD RESULT IN SNOW SHOWERS. BUT WITH THE WET GROUND, DO NOT EXPECT MUCH ACCUMULATION. THERE WILL BE A GRADUAL END TO ANY SHOWERS SLOWLY FORM WEST TO EAST TUESDAY WITH SFC HIGH PRESSURE BUILDING OVER THE AREA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 328 PM CDT MON MAY 11 2015 THE NORTHLAND CAN EXPECT A BIT OF WET PATTERN OVER THE NEXT WEEK WITH SEVERAL OPPORTUNITIES FOR RAIN. HIGH PRESSURE WILL BE OVER THE NORTHLAND TUESDAY NIGHT AND WILL MAKE FOR A COOL AND RELATIVELY CLEAR NIGHT. TEMPERATURES WILL DIP INTO THE LOWER 30S AND UPPER 20S. THERE WILL BE INCREASING CLOUD COVER FROM THE WEST LATE TUESDAY NIGHT AND WEDNESDAY AS A MID LEVEL FRONTOGENETICAL BAND MOVES INTO THE NORTHLAND. THIS FRONTOGENETICAL BAND WILL LIKELY RESULT IN RAINS SHOWERS FOR PARTS OF THE NORTHLAND WEDNESDAY AND WEDNESDAY NIGHT. THE SW FORECAST AREA HAS THE BEST CHANCE OF RAIN. A LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS WEDNESDAY NIGHT WILL LIFT INTO THE NORTHERN PLAINS THURSDAY AND THURSDAY NIGHT. THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THIS WILL BRING MORE RAIN TO THE NORTHLAND THURSDAY INTO FRIDAY. THE SOUTHERN FORECAST AREA HAS THE BEST CHANCE OF RAIN WITH THE PASSAGE OF THIS SYSTEM. WEAK HIGH PRESSURE WILL GIVE ANOTHER SHORT BREAK BETWEEN WEATHER SYSTEMS LATE FRIDAY AND SATURDAY. A LOW IN THE NORTHERN PLAINS WILL LIFT A WARM FRONT INTO THE UPPER MIDWEST. THE GFS AND ECMWF ARE IN RELATIVELY GOOD AGREEMENT THAT THE NORTHLAND WILL SEE SHOWERS AND STORMS LATE SATURDAY INTO EARLY MONDAY WITH THE PASSAGE OF THIS SYSTEM. THE SOUTHERN FORECAST AREA HAS THE BEST CHANCE OF SEEING THUNDER SINCE THE WARM FRONT MIGHT GET SHUNTED SOUTH BECAUSE OF COOL EASTERLY FLOW FROM LAKE SUPERIOR AND ONTARIO. HOWEVER...THERE COULD BE ELEVATED CONVECTION NORTH OF THE WARM FRONT...BUT THOUGHT IT TOO EARLY TO INCLUDE THUNDER OVER ALL OF THE NORTHLAND. TEMPERATURES WILL REMAIN COOL FOR THE MIDDLE OF THE WEEK...BUT WILL LIKELY REBOUND TO CLOSE TO NORMAL BY THIS WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1235 AM CDT TUE MAY 12 2015 WIDESPREAD RAIN/DRIZZLE...MIXING WITH SNOW AT TIMES...AND LIFR/IFR CONDITIONS WILL PREVAIL OVERNIGHT. CEILINGS WILL GRADUALLY IMPROVE FROM THE WEST THROUGH THE DAY AS DRIER AIR ASSOCIATED WITH BUILDING HIGH PRESSURE FILTERS INTO THE REGION. HOWEVER...THE COLD AIR MASS AND LINGERING MOISTURE WILL BE SUFFICIENT FOR INSTABILITY SHOWERS INTO THE AFTERNOON. A FEW OF THE SHOWERS WILL BE CAPABLE OF PRODUCING GUSTY NORTH WINDS TO 30 KT. && .PRELIMINARY POINT TEMPS/POPS... DLH 34 50 38 54 / 10 60 40 50 INL 30 56 40 58 / 10 0 50 50 BRD 37 52 46 59 / 10 60 50 60 HYR 31 56 43 61 / 10 40 30 50 ASX 32 52 39 57 / 10 40 40 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ UPDATE...GRANING SHORT TERM...CLC LONG TERM...GROCHOCINSKI AVIATION...CLC
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1130 PM MDT MON MAY 11 2015 AVIATION SECTION UPDATED .DISCUSSION... UPDATE FORTHCOMING. SOUTHWEST FLOW ALOFT CONTINUES TO BRING MOISTURE AND INSTABILITY TO SOUTHWEST MONTANA WHERE SCATTERED SHOWERS SHOULD CONTINUE THROUGH THE NIGHT. BOTH THE HRRR AND RUC ANALYSIS BRING SHOWERS AS FAR NORTH AS JUST ABOUT GREAT FALLS BY 12Z. TEMPERATURES OVERNIGHT LOOK ON TRACK. && .AVIATION... UPDATED 0530Z. VFR CONDITIONS EXPECTED TONIGHT. SOUTHWEST FLOW ALOFT AHEAD OF A LOW PRESSURE SYSTEM ALONG THE OREGON COAST WILL PUSH EXTENSIVE MOISTURE INTO CENTRAL/SOUTHWEST MT TONIGHT. THIS WILL RESULT IN WIDESPREAD MID-LEVEL CEILINGS (GENERALLY IN THE 6000-10000 FT RANGE) AT ALL TAF SITES WITH ISOLATED -SHRA VCNTY KHLN/KBZN DEVELOPING AROUND 09-12Z. SCATTERED SHOWERS AND ISOLATED -TSRA BECOME MORE LIKELY FROM KHLN SOUTH TO THE MT/ID BORDER BY MID-AFTN AS THE COASTAL LOW COMES INLAND AND BRINGS ADDITIONAL MOISTURE AND INSTABILITY. BRIEF MVFR CEILINGS AND MODERATE RAINFALL POSSIBLE NEAR KHLN/KBZN WITH ANY STRONGER CONVECTIVE CELLS. WARANAUSKAS && .PREV DISCUSSION...ISSUED 259 PM MDT MON MAY 11 2015 MONDAY THROUGH WEDNESDAY...CONDITIONS WILL GENERALLY CHANGE TO A WETTER PATTERN THROUGH THE MIDDLE OF THE WEEK AS SHORTWAVE TROUGHS MOVE ONSHORE AND BEGIN TO BRING MOISTURE INTO THE REGION. SOME SHOWERS OVER THE HIGHER TERRAIN WILL BE POSSIBLE THIS EVENING AS THE FIRST SHORTWAVE MOVES INTO THE AREA. PRECIPITATION WILL BE LIMITED WITH THIS SYSTEM WITH MOST OF THE SHOWERS OCCURRING OVER THE ROCKY MOUNTAIN FRONT. THE NEXT SYSTEM WILL BEGIN TO MOVE INTO MONTANA TUESDAY NIGHT AND SHOULD BRING AN INCREASE IN SHOWERS AND THUNDERSTORMS TO THE AREA TUESDAY AFTERNOON AND EVENING. THIS EVENT LOOKS LIKE IT SHOULD BRING MORE WIDESPREAD PRECIPITATION TO THE AREA AS THE MOVES ACROSS THE STATE WEDNESDAY. PRECIPITATION IS EXPECTED TO DECREASE WEDNESDAY AFTERNOON AND EVENING. TEMPERATURES SHOULD COOL OFF TUESDAY AND WEDNESDAY BACK BELOW SEASONAL AVERAGES. SUK WEDNESDAY NIGHT THROUGH MONDAY. AT THIS TIME, FORECAST CONFIDENCE IS LOW FOR MUCH OF THIS PERIOD AS PRIMARY FORECAST MODELS NOT SHOWING MUCH CONSENSUS, ESPECIALLY ON PRECIPITATION COVERAGE AND AMOUNTS. THE MODEL DIFFERENCES CENTER ON THE EVOLUTION OF A BROAD SHORTWAVE TROF THAT WILL BE OFF THE CALIFORNIA COAST ON THURSDAY. MODELS ARE IN GENERALLY GOOD AGREEMENT THAT THE TROF WILL MAKE SLOW EASTWARD PROGRESS AND BE CENTERED OVER THE GREAT BASIN/DESERT SOUTHWEST BY LATE FRIDAY. PLUMES OF MOISTURE STREAMING NORTHWARD AHEAD OF THE TROF AXIS WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS INTO MT BY THURS AFTN CONTINUING THRU FRIDAY, WITH THE ECMWF MODEL INDICATING MUCH WIDER PRECIP COVERAGE OVER CENTRAL/SOUTHWEST MT. THINGS GET MORE COMPLICATED OVER THE WEEKEND AS THE TROF LIFTS NORTHEASTWARD TOWARD THE CENTRAL ROCKIES. BOTH THE GFS AND EC MODELS SHIFT OUR WINDS ALOFT TO EASTERLY AS THE TROF PASSES TO OUR SOUTH, SETTING UP THE POSSIBILITY OF PULLING EXTENSIVE GULF OF MEXICO MOISTURE THROUGH THE UPPER MIDWEST AND INTO THE TREASURE STATE ON BOTH SAT/SUN. THE EC IS NOTABLY STRONGER WITH THIS LONG MOISTURE FETCH, DRIVEN MAINLY BY A CLOSED MID-LEVEL LOW PRESSURE AREA WITHIN THE TROF, WHEREAS THE GFS INDICATES AN OVERALL WEAKER TROF WITH LESS MOISTURE OVER OUR REGION. IN FACT, THE GFS HAS MUCH OF THE TROF AND PRECIPITATION OUT OF OUR AREA BY SUNDAY MORNING WHILE THE EC PAINTS EXTENSIVE RAINFALL WITH AMOUNTS RANGING FROM 0.1 INCH ALONG THE HI-LINE TO 0.5-0.75 INCH FROM GREAT FALLS SOUTHWARD TO THE IDAHO BORDER. GIVEN THE TROUBLESOME MODEL DIFFERENCES, THE CURRENT EXTENDED FORECAST LARGELY RELIES ON CLIMATOLOGICAL PRECIP PROBABILITIES (MOSTLY 30-40%) FOR SATURDAY AND EARLY SUNDAY, THEN REDUCES RAINFALL CHANCES SUN EVE INTO MONDAY AS THE TROF HEADS TOWARD THE GREAT LAKES STATES. THE GOOD NEWS IS THAT IT LOOKS THAT MOST/ALL OF THE FORECAST AREA SHOULD RECEIVE SOME NEEDED RAINFALL THIS WEEKEND; WE`LL JUST HAVE TO WAIT FOR ADDITIONAL MODEL OUTPUT TO GET A BETTER ESTIMATE ON AMOUNTS. AS FOR TEMPERATURES, THEY WILL REMAIN AT OR SLIGHTLY ABOVE SEASONAL VALUES THROUGH THE LATTER HALF OF THE WEEK, WITH HIGHS IN THE MID- AND UPPER 60S EACH DAY. WARANAUSKAS && .PRELIMINARY POINT TEMPS/POPS... GTF 36 60 41 59 / 10 20 30 60 CTB 30 56 35 51 / 10 10 20 70 HLN 40 61 41 65 / 30 30 40 50 BZN 38 60 38 66 / 20 20 50 40 WEY 30 62 31 61 / 30 40 40 30 DLN 41 62 41 67 / 20 40 50 40 HVR 33 63 36 59 / 10 10 20 60 LWT 37 59 39 63 / 20 20 30 50 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
411 AM CDT TUE MAY 12 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 359 AM CDT TUE MAY 12 2015 HIGH PRESSURE CENTERED ACROSS KS MOVES EAST INTO MISSOURI TODAY. LOW PRESSURE WILL BEGIN TO ORGANIZE ACROSS THE NRN HIGH PLAINS THIS AFTERNOON. THE MODEL CONSENSUS SHOWS STRONG RETURN FLOW DEVELOPING THIS AFTERNOON WITH SOUTH WINDS INCREASING TO 20 TO 30 MPH ACROSS WRN NEB. THESE WINDS SHOULD CONTINUE TONIGHT AS THE LOW LEVEL JET FORMS AND STRENGTHENS TO AROUND 50 KT. THE TEMPERATURE FORECAST TODAY FOLLOWS THE WARMER SIDE OF THE MODEL CONSENSUS. SEVERAL MODELS WERE VERY COLD WITH HIGHS IN THE 60S WHILE THE RAP WAS VERY WARM WITH HIGHS IN THE UPPER 70S. THE FORECAST IS FOR HIGHS IN THE UPPER 60S TO MID 70S. LOWS TONIGHT FALL INTO THE UPPER 40S TO AROUND 50. SOUTH WINDS AT 15 TO 20 MPH SHOULD KEEPS LOWS MILD. LASTLY...THE MODELS SHOW A WEAK DISTURBANCE FIRING THUNDERSTORMS ON THE LARAMIE AND FRONT RANGES LATE THIS AFTERNOON AROUND 21Z WHICH CARRY EAST TOWARD WESTERN NEBRASKA. THE BEST GUESS IS FOR ISOLATED SPRINKLES THIS EVENING. THE GFS WAS THE WET MODEL WHICH ACTUALLY SHOWS SOME MEASURABLE QPF. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 359 AM CDT TUE MAY 12 2015 MODELS CONTINUE TO ADVERTISE A RAPID RETURN OF GULF MOISTURE TAKING PLACE WEDNESDAY...WITH MODELS PROJECTING 850 MB DEW POINTS IN THE 10 TO 12C RANGE BY WEDNESDAY EVENING ACROSS THE REGION. A LARGE UPPER TROUGH WILL BE TAKING SHAPE ALONG THE WEST COAST MID TO LATE WEEK...WITH A LEAD SHORTWAVE EJECTING NORTHEAST THROUGH THE PLAINS AHEAD OF THE TROUGH WEDNESDAY NIGHT INTO THURSDAY. THIS SYSTEM IS SHOWN TO HAVE SOMEWHAT OF A NEGATIVE TILT...WHICH WILL HELP DRAW MOISTURE WESTWARD INTO THE HIGH PLAINS. THE COMBINATION OF STRONG LIFT AND MOISTURE TRANSPORT ON A SOUTHERLY LOW LEVEL JET...CONTINUES TO GIVE CONFIDENCE THAT PRECIPITATION SHOULD RESULT LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. WILL MAINTAIN THE LIKELY POPS ALONG AND EAST OF HIGHWAY 83 WEDNESDAY NIGHT...AND ALSO INTRODUCE EVENING LIKELY POPS ALONG A SURFACE TROUGH ACROSS THE PANHANDLE INTO THE WESTERN SANDHILLS. THE LEAD WAVE QUICKLY PASSES AND MOVES NORTHEAST AWAY FROM THE AREA THURSDAY. ATTENTION THEN TURNS TO THE LONG WAVE TROUGH ALONG THE WEST COAST. MODELS/ENSEMBLES PROJECT THIS TO MOVE EAST AS A CLOSED SYSTEM DURING THE WEEKEND. THE GENERAL CONSENSUS IN THE MODELS AND ENSEMBLE MEAN IS FOR THE CENTER OF THE SYSTEM TO TRACK ACROSS WYOMING INTO SOUTH DAKOTA. THIS PUTS OUR AREA IN THE WARM MOIST SECTOR. INSTABILITY LOOKS TO BE STRONG...AND AS DEEP LAYER SHEAR INCREASES...STRONG TO SEVERE STORMS WILL LIKELY RESULT. WILL INTRODUCE THE POTENTIAL FOR SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER OUTLOOK FOR FRIDAY AND SATURDAY. THE GFS AND ECMWF CONTINUE TO DIFFER SOMEWHAT ON THE LOW LEVEL BOUNDARY PLACEMENT...BUT THE LATEST TREND IS TO HOLD THE DRY LINE BACK TO THE WEST ACROSS WESTERN NEBRASKA INTO WESTERN KANSAS...WHICH WOULD PLACE SEVERE STORM DEVELOPMENT ACROSS THE FORECAST AREA OF WESTERN AND NORTH CENTRAL NEBRASKA. WE WILL LIKELY BE IN THE MIDST OF THE MID LEVEL DRY SLOT SUNDAY AS THE STORM SYSTEM CROSSES THE DAKOTAS...BUT AT LEAST SOME CHANCE FOR SHOWERS IN WRAP AROUND PATTERN ACROSS NORTHERN NEBRASKA. DRY WEATHER FOR MONDAY...THEN MORE CHANCES FOR RAIN NEXT WEEK BEYOND THE FORECAST PERIOD...AS THE NEXT DEEP TROUGH MOVES EAST INTO THE WESTERN CONUS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT) ISSUED AT 1120 PM CDT MON MAY 11 2015 EXCEPT FOR A BRIEF PERIOD OF MIDDLE CLOUD CEILINGS 10-14Z... UNLIMITED CEILING AND VISIBILITY ARE FORECAST TO CONTINUE TONIGHT AND TUESDAY THROUGH LATE TUESDAY EVENING. VARIABLE WIND IS EXPECTED TONIGHT AS HIGH PRESSURE DRIFTS TO THE EAST AND WIND SWINGS AROUND TO THE SOUTH. WIND WILL INCREASE TUESDAY MORNING AND...BY 15Z...IS EXPECTED TO BE 150-180 AT 12-15G20-24. THE WIND IS THEN EXPECTED TO CONTINUE INCREASING...BECOMING 160-180 AT 18-22G28-32KT. AFTER 00Z...THE WIND WILL DECREASE TO 12-14G20-22KT. && .HYDROLOGY... ISSUED AT 359 AM CDT TUE MAY 12 2015 THE COMBINATION OF SEASONAL SNOW MELT IN THE UPPER SOUTH PLATTE RIVER BASIN AND RECENT HEAVY PRECIPITATION OVER WESTERN NEBRASKA AND NORTHEAST COLORADO WILL LEAD TO FLOODING ON THE SOUTH PLATTE AND PLATTE RIVERS IN SOUTHWEST NEBRASKA LATER THIS WEEK AND INTO EARLY NEXT WEEK. AT THIS TIME SOME UNCERTAINTY STILL REMAINS WITH THE FORECAST AS KEY UPSTREAM GAUGES IN NORTHEAST COLORADO HAVE YET TO CREST. HOWEVER...LATEST PROJECTIONS CONTINUE TO HIGHLIGHT AN INCREASING THREAT FOR SIGNIFICANT FLOODING TO OCCUR...POTENTIALLY NEAR SEPTEMBER 2013 FLOOD LEVELS. RIVER STAGE FORECASTS WILL BE CLOSELY MONITORED AND UPDATED ONCE MORE UPSTREAM RIVER DATA BECOMES AVAILABLE. PERSONS THAT LIVE IN VULNERABLE AREAS ALONG THE SOUTH PLATTE RIVER AND PLATTE RIVER IN SOUTHWEST NEBRASKA SHOULD PAY CLOSE ATTENTION TO FLOOD FORECASTS IN THE COMING DAYS AND BE PREPARED TO TAKE PROPER ACTION. && .LBF WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR NEZ006>010-026>029-038-058-059-069>071. FREEZE WARNING UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR NEZ004- 005-022>025-035>037-056-057-094. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...SPRINGER HYDROLOGY...MARTIN/TAYLOR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1242 AM CDT TUE MAY 12 2015 .UPDATE... ISSUED AT 1242 AM CDT TUE MAY 12 2015 TEMPS ARE FALLING SLOWLY AS WINDS ARE STILL 5-7 KTS MOST LOCATIONS. 04Z HRRR INDICATES THE SFC RIDGE AXIS WILL MOVE THRU RIGHT AROUND DAWN. WINDS SHOULD THEN DROP OFF AND ALLOW TEMPS TO REACH THE LOW-MID 30S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 1242 AM CDT TUE MAY 12 2015 THIS SERVES AS THE FIRST DRAFT FOR THIS SHIFT... ALOFT: HEIGHTS WILL CONT TO RISE TODAY. WNW FLOW WILL TRANSITION TO WSW TONIGHT AS A SHORTWAVE RIDGE PASSES THRU. SURFACE: HIGH PRES WAS OVER KS AT 08Z AND WILL DRIFT E OF THE REGION TODAY. MEANWHILE...LOW PRES WILL CONT ORGANIZING OVER THE INTERMOUNTAIN W THRU TONIGHT. RETURN FLOW WILL RESULT WITH A TIGHTENING PRES GRAD. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 339 PM CDT MON MAY 11 2015 A LARGE AREA OF LOW PRESSURE WILL DROP SOUTH ACROSS THE WESTERN STATES OVER THE MIDDLE OF THE WEEK...RESULTING IN GENERALLY SOUTHWESTERLY FLOW ALOFT AND MULTIPLE CHANCES FOR THUNDERSTORMS BEGINNING WEDNESDAY AFTERNOON. TEMPERATURE WISE...GENERALLY MILD CONDITIONS ARE EXPECTED THROUGH THE EXTENDED PERIODS...WITH TEMPERATURES EXPECTED TO BE NEAR OR ABOVE CLIMATOLOGY EACH DAY. STARTING WEDNESDAY...EXPECT A WEAK UPPER LEVEL DISTURBANCE/OPEN WAVE TO BE LIFTED NORTHWARD ACROSS THE PLAINS AS A LARGE AREA OF LOW PRESSURE CIRCULATES ACROSS THE WESTERN STATES. WHILE SOUTHERLY RETURN FLOW WILL HELP DEWPOINTS CLIMB BACK TO NEAR 50 BY WEDNESDAY AFTERNOON...INSTABILITY WILL STILL BE VERY MARGINAL...SO OPTED TO ONLY MENTION AN ISOLATED THUNDERSTORM WEDNESDAY/WEDNESDAY NIGHT...WITH THE FOCUS OF THIS ACTIVITY SHIFTING SLIGHTLY EASTWARD FROM PREVIOUS FORECASTS AS THE LLJ IS FORECAST TO BE FOCUSED JUST EAST OF THE LOCAL AREA. WHILE INSTABILITY VALUES WILL BE A LITTLE MORE RESPECTABLE ON THURSDAY AFTERNOON...THE LACK OF ANY SIGNIFICANT FORCING MECHANISM SHOULD HELP LIMIT ANY DEVELOPMENT TO PRIMARILY THE DAYTIME HOURS... DEPENDING ON THE TIMING OF THE AFOREMENTIONED DISTURBANCE...WITH DRY WEATHER ANTICIPATED THURSDAY NIGHT INTO FRIDAY MORNING. THEREAFTER...INSTABILITY WILL INCREASE SIGNIFICANTLY ACROSS THE LOCAL AREA WITH MULTIPLE DISTURBANCES PASSING OUT OF THE LONGWAVE TROUGH. THIS SHOULD RESULT IN MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE LOCAL AREA FOR THE END OF THE WEEK AND START OF THE UPCOMING WEEKEND. IN ADDITION...WITH A MODEST LLJ EXPECTED TO DEVELOP EACH NIGHT...INCREASING SHEAR VALUES...AND MULTIPLE PASSING UPPER LEVEL DISTURBANCES...EXPECT THE POTENTIAL FOR SOME SEVERE WEATHER TO RETURN ON FRIDAY AND SATURDAY...WITH THE LOCAL AREA NOW HIGHLIGHTED FOR A CHANCE OF SEVERE WEATHER BY SPC IN THEIR DAY 5 AND DAY 6 FORECASTS. COULD SEE A BREAK IN SHOWER AND THUNDERSTORM ACTIVITY LATE IN THE UPCOMING WEEKEND AND EARLY NEXT WEEK AS A SHORTWAVE TROUGH TRANSITIONS ACROSS THE PLAINS...BUT MODELS ARE HINTING AT YET ANOTHER UPPER LEVEL LOW EMERGING FROM THE SOUTHWEST EARLY NEXT WEEK WHICH COULD AFFECT THE LOCAL AREA JUST BEYOND THE CURRENT SCOPE OF THE EXTENDED FORECAST. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUE NIGHT) ISSUED AT 1242 AM CDT TUE MAY 12 2015 REST OF TONIGHT: VFR SKC. LIGHT W WINDS WILL BECOME LGT AND VRBL. CONFIDENCE: HIGH TUE: VFR WITH A PERIOD OF PATCHY OF 7K FT SCT CLOUDS. WINDS BECOME S AND WILL GUST 20-27 KTS WITH POTENTIAL FOR 32 KTS. CONFIDENCE: HIGH TUE EVE: VFR. S WINDS BECOME SSE AND WILL CONT TO GUST UP TO 25 KTS AT TIMES. HAVE INCLUDED LLWS TO COVER PERIODIC LULLS IN SFC WINDS. CONFIDENCE: HIGH && .GID WATCHES/WARNINGS/ADVISORIES... NE...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR NEZ039-040-046- 047-060>062-072>075-082>085. KS...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ005>007- 017>019. && $$ UPDATE...HALBLAUB SHORT TERM...HALBLAUB LONG TERM...ROSSI AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS NORMAN OK
325 AM CDT TUE MAY 12 2015 .DISCUSSION... EAST TO SOUTHEAST WINDS WILL DEVELOP TODAY AS SURFACE HIGH PRESSURE OVER KANSAS BUILDS EAST. MEANWHILE...CONVECTION ALONG THE EAST TEXAS COAST WILL DELAY THE RETURN OF DEEP MOISTURE NORTHWARD. SCATTERED SHOWERS AND A FEW STORMS HAVE FORMED WITHIN AN AREA OF MID-LEVEL MOISTURE RETURN OVER CENTRAL AND WEST TEXAS. THE HRRR SORTA HAS A HANDLE ON THIS AND GRADUALLY WEAKENS IT DURING THE MORNING...WHILE THE NAM12 IS MORE AGGRESSIVE IN DEVELOPING CONVECTION IN WESTERN NORTH TEXAS. FOR NOW WILL KEEP IN CHANCE POPS FOR OUR TEXAS COUNTIES. ANOTHER HEAVY RAIN EVENT SEEMS LIKELY LATE TUESDAY NIGHT INTO WEDNESDAY. MODELS ARE SIMILAR IN TRACKING A PROGRESSIVE TROUGH ACROSS THE SOUTHWESTERN STATES TONIGHT AND THEN OVER WEST TEXAS AND OKLAHOMA WEDNESDAY INTO EARLY THURSDAY. DEEP MOISTURE IN PLACE OVER SOUTH TEXAS WILL BE TRANSPORTED NORTHWARD TONIGHT INTO WEDNESDAY IN ADVANCE OF THE TROUGH. THE BEST COMBINATION OF UPPER AND LOW LEVEL JET FEATURES...SHOULD FOCUS THE HEAVIEST RAIN OVER WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA EARLY WEDNESDAY...WITH A GRADUALLY SHIFT NORTH AND EAST DURING THE AFTERNOON AND NIGHT. WIDESPREAD 2 INCH RAIN AMOUNTS ARE LIKELY WITH 3 TO 4 INCH TOTALS POSSIBLE. WITH RECENT HEAVY RAIN OVER THE SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS...FLOODING WILL AGAIN BE A CONCERN. BRIEF SHORTWAVE RIDGING ON THURSDAY WILL KEEP RAIN CHANCES LOW...BUT ANOTHER TROUGH WILL BEGIN TO SHIFT EASTWARD FRIDAY INTO THE WEEKEND. BETTER INSTABILITY IS EXPECTED TO DEVELOP AHEAD OF THIS SYSTEM WHICH WILL RESULT IN AN INCREASE IN SEVERE WEATHER CHANCES FRIDAY INTO SATURDAY. ANOTHER FRONT IS EXPECTED TO PUSH ACROSS THE SOUTHERN PLAINS SUNDAY INTO MONDAY WHICH WILL BRING ANOTHER PERIOD OF DRY WEATHER. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 71 56 67 62 / 0 30 80 80 HOBART OK 71 56 67 61 / 0 40 90 70 WICHITA FALLS TX 72 59 70 64 / 10 60 90 70 GAGE OK 71 53 66 56 / 0 20 70 60 PONCA CITY OK 72 53 66 59 / 0 10 70 90 DURANT OK 73 59 71 64 / 10 40 80 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR OKZ007-008-012-013-017>020-022>048-050>052. TX...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR TXZ083>090. && $$
AREA FORECAST DISCUSSION
NWS PORTLAND
915 PM PDT MON MAY 11 2015 .SYNOPSIS...AN UPPER LOW WILL MOVE INLAND AND ACROSS SOUTHWESTERN OREGON TONIGHT AND TUESDAY. A BAND OF STRATIFORM RAIN ALONG THE COLUMBIA RIVER WILL PINWHEEL SOUTH ALONG THE COAST AND RETURN INLAND ACROSS THE CENTRAL AND SOUTHERN OREGON COAST TUESDAY. THE UPPER LOW WILL GRADUALLY FILL AS IT DRIFTS NORTHEAST TOWARD EASTERN WASHINGTON TUESDAY NIGHT AND WEDNESDAY WITH LIGHT SHOWER ACTIVITY CONTINUING. AT THE SAME TIME...ANOTHER LOW DROPS SOUTH OFF THE PACIFIC NORTHWEST COAST AND SLOWLY MOVES INTO CALIFORNIA DURING THE LATTER PART OF THE WEEK AND NEXT WEEKEND. && .UPDATE...UPPER LOW CENTER ROUGHLY OVER THE SOUTHERN OREGON COAST NEAR PORT ORFORD. THE BULK OF CONVECTION EAST OF THE CASCADES HAS ENDED WITH A COUPLE STRAY CELLS FIRING AT THIS HOUR. 21Z SREF AND 00Z NAM/GFS RUNS ARE KEEPING THE UPPER LOW CENTER JUST THIS SIDE OF THE OR/CA BORDER FOR TONIGHT WHICH IS CLOSER TO WHAT PREVIOUS RUNS OF THE NAM HAD SHOWN. ADDITIONALLY...THE BETTER DYNAMIC LIFT ASSOCIATED WITH THE DIFFLUENT SE QUADRANT OF THE LOW DEVELOPED ABOUT 75 MILES FURTHER EAST THAN WAS PREVIOUSLY EXPECTED. THUS...A BLEND OF THE 00Z NAM...AND TO A LESSER EXTENT...THE 12Z ECMWF SEEMS TO BE A DECENT MIDDLE GROUND WITH REGARD TO HANDLING THE REST OF TONIGHT. AS SUCH...AM FEELING THE PRIMARY DEFORMATION BAND WILL STAY ALONG THE COLUMBIA RIVER WITH THE EASTERLY FLOW ALONG THE NORTHERN PERIPHERY OF THE UPPER CIRCULATION CONTINUING TO STREAM PRECIPITATION OUT TO SEA ACROSS ASTORIA. OVERNIGHT WILL SEE THE FLOW AND DEEPER MOISTURE THEN WRAP BACK SOUTH CLOSER TO THE COAST. THIS STANDS TO LEAVE THE CASCADE WEST SLOPES (NOW IN THE LEE OF THE SYSTEM) ON THE RELATIVELY DRIER SIDE OF THINGS. THE LEADING EDGE OF THE WRAP AROUND MOISTURE THEN CURLS BACK INLAND AROUND NEWPORT/FLORENCE AND PICKS UP A BIT OF UPSLOPE ENHANCEMENT FOR THE MORNING HOURS TOMORROW. DID NOT HAVE ENOUGH CONFIDENCE THEREAFTER TO MAKE CHANGES TO THE FORECAST PACKAGE AS WE WILL NEED TO SEE HOW THIS FIRST PART WORKS OUT. IT SHOULD BE SAID THAT NO ONE MODEL IS REALLY DOING A STELLAR JOB OF FINDING THE CORRECT MIX OF RAIN PLACEMENT WITH RAIN INTENSITY LEAVING THIS FORECAST WITH MODERATE CONFIDENCE AT BEST. UPDATES WILL BE AVAILABLE SHORTLY. /JBONK && .AVIATION...RAIN AND OCCASIONAL MVFR CIG/VIS ARE SPREADING WEST AND SOUTH THIS EVENING WITH THE TREND CONTINUING INTO THE LATE EVENING. EXPECT MORE WIDESPREAD MVFR CONDITIONS TO DEVELOP THROUGH THE OVERNIGHT AND STICK AROUND MUCH OF TUESDAY WITH RAIN. WINDS WILL BE VARIABLE THROUGH THE PERIOD AND GENERALLY REMAIN BELOW 10 KT. KPDX AND APPROACHES...MVFR CIGS DEVELOPING BY 12Z TUESDAY AND STAYING THROUGH TUESDAY. OCCASIONAL MVFR VIS WITH RAIN. BOWEN && .MARINE...HIGH PRESSURE OVER THE NE PACIFIC IS KEEPING CONDITIONS FAIRLY BENIGN. SEAS SHOULD REMAIN AROUND 5 TO 7 FT THROUGH TUESDAY WITH NORTHWESTERLY WINDS STAYING BELOW 20 KT. SEAS WILL BE CHOPPY DUE TO SHORT PERIODS AROUND 8 SECONDS. MADE ONLY MINOR TWEAKS TO THE FORECAST FOR THE EVENING UPDATE. BOWEN A WEAK LOW PRESSURE SYSTEM MOVES THROUGH ON WEDNESDAY...BUILDING SEAS TO AROUND 8 FT...BUT WINDS EXPECTED TO REMAIN BELOW 20 KT. SEAS FALL BACK DOWN TO 5 TO 6 FT BY THE END OF THIS WEEK WITH THE RETURN OF NORTHWESTERLY WINDS AS HIGH PRESSURE BUILDS BACK OVER THE WATERS. -MCCOY && .PREV DISCUSSION... /ISSUED 215 PM PDT MON MAY 11 2015/ SHORT TERM...TONIGHT THROUGH THURSDAY...EARLY-AFTERNOON WATER VAPOR LOOP SHOWS AN UPPER LEVEL LOW CENTERED WEST OF KONP AND SINKING TO THE S. CONSIDERABLE MOISTURE IN WATER VAPOR FOCUSED OVER THE CASCADES. ALSO LOOKS LIKE A SHORT-WAVE ROTATING INTO SOUTH-CENTRAL OREGON...WHICH HAS RESULTED IN THUNDERSTORM ACTIVITY IN SWRN LAKE COUNTY. KRTX DUAL-POL DOPPLER RADAR SHOWS THE BULK OF THE PRECIP ECHOES ALONG THE CENTRAL AND NORTH OREGON CASCADES INTO ERN CLARK AND COWLITZ COUNTIES IN SW WA. 12Z MODEL RUNS AGREE THAT THE UPPER LOW WILL CONTINUE TO DRIFT SOUTH THIS EVENING...THEN MOVE INLAND OVER NW CALIFORNIA BY 12Z TUE. MODELS ALSO SUGGEST THAT PRECIP WILL BECOME MORE ENHANCED LATE THIS AFTERNOON DUE TO SE-S MID-LEVEL FLOW. HOWEVER...MODELS DO NOT SEEM TO AGREE ON QPF. GFS SHOW MUCH MORE RAINFALL TONIGHT THAN THE NAM OR ECMWF. THE NAM PIVOTS THE DEVELOPING DEFORMATION BAND FURTHER N THAN THE GLOBAL MODELS. THE 19Z HRRR RUN HAS THE DEFORMATION BAND DEVELOPING A FEW HOURS LATER THAN THE EARLIER MORNING RUNS INDICATED...AND SETTLING OVER SRN WA DOWN TO ABOUT A KTMK-KSLE-MT. HOOD LINE BY 07Z TUE. HIGH CONFIDENCE IN WETTING RAIN AMOUNTS...ONE-QUARTER INCH OR GREATER...ACROSS PORTIONS OF THE CWA TONIGHT AND TUE MORNING. LOWER CONFIDENCE ON EXACT LOCATION OF THE DEFORMATION BAND. CONVECTIVE CHANCES TODAY DO NOT LOOK ALL THAT IMPRESSIVE. NAM SOUNDINGS FOR KPDX SHOW AN ISOTHERMAL LAYER THIS AFTERNOON BETWEEN 850 AND 700 MB. MODEL SOUNDING FOR A POINT IN THE CASCADES HAS THE SAME GENERAL PROFILE...BUT DOES HAVE AN LI NEAR 0C THIS AFTERNOON. INCREASED POPS IN THE 00-06Z TUE TIME FRAME...ESPECIALLY IN THE CASCADES AND NORTHERN ZONES. THE DEFORMATION ZONE PERSISTS TUE MORNING. THE NAM ROTATES IT ACROSS SW WA TO THE N OREGON COAST BY 18Z TUE...SIMILAR TO THE ECMWF. IT FINALLY BREAKS UP TUE AFTERNOON. THE MODELS SHOW A DECENT AMOUNT OF CYCLONIC LOW LEVEL ONSHORE FLOW DEVELOPING BELOW THIS BAND AS WELL. CASCADE MODEL SOUNDINGS SUGGEST A LIT MORE SUPPORT FOR CONVECTION TUE AFTERNOON. NAM SOUNDING GIVES 200-250 J/KG CAPE 00Z WED...WHILE THE GFS HAS NEAR-ZERO LI VALUES. THE REMAINS OF THE UPPER LOW LIFT OUT INTO SE WASHINGTON TUE NIGHT AND INTO NE WA BY WED AFTERNOON. ANY REMAINING DEFORMATION WILL LINGER OVER THE S WA CASCADES WED MORNING AND HAVE THE HIGHEST POPS THERE. DECIDED TO INCLUDE A MENTION OF THUNDERSTORMS FOR THE CENTRAL AND N OREGON CASCADES BEGINNING WED AFTERNOON. MODEL SOUNDINGS SHOW A DEFINITE CAP AROUND 700 MB WED MORNING...BUT BY 21Z THE CAP IS GONE WITH CAPE OVER 100 J/KG. AT 00Z THU MODEL CAPE HAS INCREASED TO NEARLY 300 J/KG WITH LI -1C. THINK THE S WA CASCADES WILL HAVE TOO MUCH CLOUD COVER AS THE DEFORMATION BAND SLOWLY DRIFTS N. MUCH MORE IMPRESSIVE CONVECTIVE ENVIRONMENT POSSIBLE THU. PRIMARY UPPER LOW SETTLES OFF THE N CALIFORNIA COAST THU AFTERNOON...WHICH SETS UP UNSTABLE SE-S FLOW OVER THE FORECAST AREA. NAM SOUNDING NEAR SANTIAM PASS HAS NEARLY 550 J/KG CAPE WITH AN LI OF -2C 00Z FRI. GFS EVEN MORE IMPRESSIVE WITH CONVECTIVE PARAMETERS THU. WEISHAAR LONG TERM...THURSDAY NIGHT THROUGH SUNDAY...BY THURSDAY NIGHT A BROAD UPPER LOW PRESSURE WILL CONTINUE A GENERAL TRACK SOUTHWARD ALONG THE CALIFORNIA COAST. MODEL GUIDANCE THIS AFTERNOON IS COMING INTO GOOD AGREEMENT WITH THE GENERAL PATTERN AND EXPECT SHOWERS LINGERING THURSDAY NIGHT AND ALSO ON FRIDAY...WITH THE BEST CHANCES TOWARDS THE CASCADES. MIGHT ALSO BE ENOUGH INSTABILITY TO GET A FEW THUNDERSTORMS NEAR THE CASCADES FROM MT HOOD SOUTHWARD ON FRIDAY. THIS UPPER LOW CONTINUES EASTWARD WITH THE NEXT UPPER LOW PRESSURE SYSTEM MOVING TOWARDS THE REGION OVER THE WEEKEND...MAINTAINING ONSHORE FLOW ALOFT AND THE POTENTIAL FOR CONTINUING SHOWERS THIS WEEKEND. OVERALL...NOT MUCH CHANGE TO THE OVERALL PATTERN THROUGH THE EXTENDED PERIOD WITH TEMPERATURES NEAR SEASONAL NORMS AND SHOWER CHANCES CONTINUING. CULLEN && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...NONE. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
346 AM EDT TUE MAY 12 2015 .SYNOPSIS... SUMMERTIME WARMTH AND HUMIDITY WILL COME TO AN END TODAY AS A VIGOROUS UPPER TROF AND ASSOCIATED COLD FRONT CROSSES THE REGION. COOLER...DRIER AND WINDY CONDITIONS WILL ARRIVE DURING THE DAYLIGHT HOURS TUESDAY...AND LAST THROUGH WEDNESDAY NIGHT. MILDER CONDITIONS WILL RETURN FOR THURSDAY AND FRIDAY AND CONTINUE THIS WEEKEND AS ANOTHER UPPER RIDGE BUILDS ACROSS THE REGION. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... SFC-850 MB NORTH/SOUTH THETA-E RIDGE WAS SLICING RIGHT THROUGH CENTRAL PENN AT 07Z WITH JUST SOME ISOLATED-SCATTERED SHOWERS RACING QUCIKLY TO THE ENE. SFC DEWPOINTS DROPPING OFF BY SEVERAL DEG F ALONG THE PENN/OHIO BORDER ATTM /MARKING THE WEAK...INITIAL COLD FRONT THAT WILL SLIDE ACROSS MUCH OF THE FCST AREA BY 12Z. TEMPS WILL STAY MILD FOR THE REST OF THE NIGHT AND IT WILL FEEL MUGGY WITH TEMPS AND DEWPOINTS IN THE L-M 60S /EXCEPT U50S INVOF KBFD/. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... INITIAL CFRONT CLEARS OUR FAR EASTERN COUNTIES DURING THE MID MORNING HOURS TODAY...FOLLOWED BY WINDY AND DRIER CONDITIONS IN STORE FOR MOST OF THE REGION. MODEL FORECAST SOUNDINGS INDICATE MODERATE MIXING POTENTIAL WITH MANY AREAS SEEING 30-35 MPH GUSTS OR HIGHER. EXPECT HIGHER TERRAIN OF THE NORTH AND WEST TO SEE SCT -SHRA...WHILE CENTRAL AND SOUTHEAST AREAS REMAIN PARTLY SUNNY AND DRY. HIGHS WILL RANGE FROM JUST 60 TO 65F ACROSS THE NORTHWEST MTNS...TO THE LOWER 80S THROUGHOUT THE LOWER SUSQ RIVER VALLEY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... STILL LOOKING AT A FEW SHOWERS ACROSS THE NORTH TUESDAY NIGHT INTO WED...WITH THE COLD AIR ALOFT. IT WILL BE BREEZY AND COLDER FROM LATE TUE INTO THU MORNING. LATER SHIFTS WILL NEED TO MONITOR THE NEED FOR FROST AND FREEZE PRODUCTS. MID SHIFT INSERTED SHOWERS INTO THE FCST FOR FRIDAY INTO SAT. THIS BASED ON WEAK SYSTEM DROPPING SE. WHILE MOISTURE MAY BE LIMITED...DIRECTIONAL SHEAR WILL BE THERE. I DID CUT BACK ON THE SHOWERS SOME ON THE FIRST PART OF FRIDAY. DID ADJUST POPS SOME FOR SUNDAY...AS SYSTEM DROPS SE OF OUR AREA...DID CUT BACK SOME. FOR MONDAY...ADJUSTED POPS SOME MORE...AS WE WILL BE ON THE EASTERN AND NORTHERN EDGE OF THE WARM ADVECTION. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... RADAR AT 06Z SHOWS ONE LINE OF SHRA/TSRA PUSHING THRU EASTERN PA AND ANOTHER BATCH OF SHRA ASSOC WITH APPROACHING COLD FRONT OVER WESTERN PA. FOR MUCH OF CENTRAL PA...NO SIG CIG/VIS REDUCTIONS ARE EXPECTED EARLY THIS MORNING. THE EXCEPTION COULD BE KBFD AND KJST...WHERE A BRIEF PERIOD OF IFR CIGS MAY DEVELOP AS PLUME OF MOIST AIR ALONG COLD FRONT ASCENDS THE W MTNS. MDL RH TIMESECTIONS AND HRRR OUTPUT SUGGEST THE WINDOW OF OPPORTUNITY FOR IFR CONDS AT KBFD/KJST WILL BE 09Z-11Z. AFTER 11Z...DRIER AIR WILL ARRIVE ON WEST WIND...CAUSING IMPROVING CONDS. WIDESPREAD VFR CONDS EXPECTED AFTER SUNRISE...AS DRIER AIR FLOWS IN BEHIND COLD FRONT. MAIN CONCERN TODAY WILL BE THE GUSTY WEST WINDS...RESULTING FROM TIGHT PRESSURE GRADIENT SOUTH OF LOW PRES OVR S QUEBEC. MDL SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS BY THIS AFTN. THE STRONGEST GUSTS WILL DIMINISH AFTER SUNSET...BUT IT WILL REMAIN BREEZY OVERNIGHT. OUTLOOK... WED...NO SIG WX EXPECTED. THU...EARLY AM FOG POSS NW MTNS. FRI...PM SHRA/CIG REDUCTIONS POSS...MAINLY NW MTNS. SAT...SCT PM TSRA IMPACTS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DEVOIR/LAMBERT NEAR TERM...DANGELO/LAMBERT SHORT TERM...DEVOIR LONG TERM...MARTIN AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
237 AM EDT TUE MAY 12 2015 .SYNOPSIS... SUMMERTIME WARMTH AND HUMIDITY WILL COME TO AN END LATE TONIGHT AND TUESDAY AS A VIGOROUS UPPER TROF AND ASSOCIATED COLD FRONT CROSSES THE REGION. COOLER...DRIER AND WINDY CONDITIONS WILL ARRIVE DURING THE DAYLIGHT HOURS TUESDAY...AND LAST THROUGH WEDNESDAY NIGHT. MILDER CONDITIONS WILL RETURN FOR THURSDAY AND FRIDAY AND CONTINUE THIS WEEKEND AS ANOTHER UPPER RIDGE BUILDS ACROSS THE REGION. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... COLD POOL FROM THE STORMS OVER OH AND WRN PA HAVE MADE QUITE AN ACTIVE EVENING AS IT FORMED INTO A NICE BOW ECHO. MANY DAMAGE REPORTS WITH TREES NOW PRETTY MUCH LEAFED OUT EVERYWHERE. MESO MDLS CONTINUE TO MAKE NO PRECIP TO THE SE OF AOO/UNV/IPT OVERNIGHT. BUT ALLOWING FOR SOME CONTINUATION IN THE LINE OF SHOWERS AS IT IS...BUT BUYING INTO THE WEAKENING/DISSIPATION A LITTLE MORE AS THE LATEST ECHOES PLAY THAT THE GUST FRONT IS RACING TOO FAR AHEAD OF THE SRN CELLS. THIS BODES WELL FOR WEAKENING THERE. LEFT IN JUST A 30 POP FOR AN HR OR TWO FOR THE SERN COS. COLD AIR SEEMS LIKE IT COMES IN TWO WAVES...WITH THE FIRST SURGE LATER TONIGHT BEING ACCOMPANIED BY MORE SHOWERS...MAINLY ACROSS THE NW MTNS. A SECONDARY FRONT IN THE MORNING WILL ALSO MAKE A FEW SHRA. && .SHORT TERM /8 AM THIS MORNING THROUGH 6 PM WEDNESDAY/... FRONT CLEARS SOUTHEASTERN COUNTIES EARLY TUESDAY...WITH WINDY AND DRIER CONDITIONS IN STORE FOR MOST OF THE REGION. MODEL FORECAST SOUNDINGS INDICATE MODERATE MIXING POTENTIAL WITH MANY AREAS SEEING 30-35 MPH GUSTS OR HIGHER. EXPECT HIGHER TERRAIN OF THE NORTH AND WEST TO SEE SCT -SHRA...WHILE CENTRAL AND SOUTHEAST AREAS REMAIN PARTLY SUNNY AND DRY. HIGHS WILL RANGE FROM THE UPPER 60S NORTHWEST TO THE LOWER 80S LOWER SUSQ RIVER VALLEY. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... STILL LOOKING AT A FEW SHOWERS ACROSS THE NORTH TUESDAY NIGHT INTO WED...WITH THE COLD AIR ALOFT. IT WILL BE BREEZY AND COLDER FROM LATE TUE INTO THU MORNING. LATER SHIFTS WILL NEED TO MONITOR THE NEED FOR FROST AND FREEZE PRODUCTS. MID SHIFT INSERTED SHOWERS INTO THE FCST FOR FRIDAY INTO SAT. THIS BASED ON WEAK SYSTEM DROPPING SE. WHILE MOISTURE MAY BE LIMITED...DIRECTIONAL SHEAR WILL BE THERE. I DID CUT BACK ON THE SHOWERS SOME ON THE FIRST PART OF FRIDAY. DID ADJUST POPS SOME FOR SUNDAY...AS SYSTEM DROPS SE OF OUR AREA...DID CUT BACK SOME. FOR MONDAY...ADJUSTED POPS SOME MORE...AS WE WILL BE ON THE EASTERN AND NORTHERN EDGE OF THE WARM ADVECTION. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... RADAR AT 06Z SHOWS ONE LINE OF SHRA/TSRA PUSHING THRU EASTERN PA AND ANOTHER BATCH OF SHRA ASSOC WITH APPROACHING COLD FRONT OVER WESTERN PA. FOR MUCH OF CENTRAL PA...NO SIG CIG/VIS REDUCTIONS ARE EXPECTED EARLY THIS MORNING. THE EXCEPTION COULD BE KBFD AND KJST...WHERE A BRIEF PERIOD OF IFR CIGS MAY DEVELOP AS PLUME OF MOIST AIR ALONG COLD FRONT ASCENDS THE W MTNS. MDL RH TIMESECTIONS AND HRRR OUTPUT SUGGEST THE WINDOW OF OPPORTUNITY FOR IFR CONDS AT KBFD/KJST WILL BE 09Z-11Z. AFTER 11Z...DRIER AIR WILL ARRIVE ON WEST WIND...CAUSING IMPROVING CONDS. WIDESPREAD VFR CONDS EXPECTED AFTER SUNRISE...AS DRIER AIR FLOWS IN BEHIND COLD FRONT. MAIN CONCERN TODAY WILL BE THE GUSTY WEST WINDS...RESULTING FROM TIGHT PRESSURE GRADIENT SOUTH OF LOW PRES OVR S QUEBEC. MDL SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS BY THIS AFTN. THE STRONGEST GUSTS WILL DIMINISH AFTER SUNSET...BUT IT WILL REMAIN BREEZY OVERNIGHT. OUTLOOK... WED...NO SIG WX EXPECTED. THU...EARLY AM FOG POSS NW MTNS. FRI...PM SHRA/CIG REDUCTIONS POSS...MAINLY NW MTNS. SAT...SCT PM TSRA IMPACTS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DEVOIR NEAR TERM...DANGELO SHORT TERM...DEVOIR LONG TERM...MARTIN AVIATION...FITZGERALD
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1258 AM CDT TUE MAY 12 2015 .DISCUSSION...UPDATED FOR 06Z AVIATION. && .AVIATION...CONVECTION IS THE MAIN AVIATION CONCERN IN THE SHORT TERM. LINE OF SHOWERS AND STORMS CONTINUES TO MOVE W TO E ACROSS SOUTH TEXAS. KEPT SHRA/TSRA REMARKS IN THE TAFS FOR THE NEXT SEVERAL HOURS. LOCALLY REDUCED VSBYS AND ERRATIC WINDS WILL OCCUR IF THUNDERSTORMS DIRECTLY IMPACT TAFS. LAST COUPLE OF HRRR RUNS INDICATE THERE COULD BE A LULL IN ACTIVITY LATER THIS MORNING AS THIS ROUND OF STORMS MOVES OFF TO THE EAST. HOWEVER...ADDITIONAL ACTIVITY WILL BE POSSIBLE AGAIN TODAY AS MOIST AIRMASS AND BOUNDARY REMAINS IN THE AREA. IFR/MVFR CEILINGS TONIGHT SHOULD TRANSITION TO MOSTLY MVFR/LOW END VFR DURING THE DAY ON TUESDAY. OUTSIDE OF THUNDERSTORMS...WINDS WILL GENERALLY BE OUT OF THE EAST AND ESE. && .PREV DISCUSSION... /ISSUED 924 PM CDT MON MAY 11 2015/ DISCUSSION...OTHER THAN THE IMPRESSIVE SUPERCELL THAT SAT OVER SOUTHERN DUVAL COUNTY FOR AWHILE BEFORE MOVING EAST-SOUTHEAST TO THE FALFURRIAS AREA...CONVECTION HAS BEEN GENERALLY DISORGANIZED. SURFACE TO 6 KM SHEAR WAS NOT QUITE AS STRONG AS ANTICIPATED AS WELL AS SLIGHTLY LOWER INSTABILITY DUE TO CLOUD COVER. BUT 00Z CRP SOUNDING STILL SHOWED MEAN LAYER CAPE AROUND 2500 J/KG AS MOISTURE HAS INCREASED SUBSTANTIALLY WITH PRECIPITABLE WATER VALUES UP TO 2.15 INCHES. SLOW MOVING SUPERCELL OVER DUVAL COUNTY LIKELY PRODUCED BETWEEN 7 AND 10 INCHES OF RAIN...BETWEEN BRUNI AND REALITOS EARLIER THIS EVENING...AS STORM INGESTED THIS HIGHER MOISTURE SOURCE ALONG THE COAST. WATER VAPOR IMAGERY SHOWS A MID LEVEL SHORT WAVE TROUGH OVER NORTHWEST MEXICO MOVING TO THE EAST. THE INCREASING MID AND UPPER LEVEL FLOW ASSOCIATED WITH THIS SHORT WAVE TROUGH WILL MOVE OUT OF NORTHEAST MEXICO INTO THE BRUSH COUNTRY OVERNIGHT. THIS WILL INCREASE THE OVERALL SHEAR PROFILE THROUGH THE NIGHT. LATEST HI- RES MODELS INDICATE THE POTENTIAL FOR A MORE ORGANIZED CONVECTIVE COMPLEX TO FORM OVER THE RIO GRANDE PLAINS AND MOVE EAST-SOUTHEAST LATER TONIGHT. INFRARED SATELLITE TRENDS SHOW COOLING CLOUD TOPS WITH AREA OF CONVECTION FROM THE WESTERN HILL COUNTRY SOUTH TO NORTHWEST OF LAREDO. HARD TO DISCERN WHERE FRONTAL BOUNDARY IS WITH AREAS OF CONVECTION BUT THE BOUNDARY MAY BE OVER THE NORTHERN COUNTIES AT THIS TIME. LOW LEVEL CONVERGENCE MAY BE SLIGHTLY HIGHER NEAR THIS BOUNDARY WITH CONVECTION TO THE NORTHWEST MOVING ALONG IT. WILL REMOVE THE MENTION OF SEVERE FOR THE REST OF TONIGHT...ALTHOUGH THREAT FOR ISOLATED SEVERE STORMS WILL STILL EXIST...AND RETAIN LOCALLY HEAVY RAINFALL IN FORECAST. NO CHANGES MADE TO THE FLASH FLOOD WATCH AREA WITH BETTER THREAT NEAR THE BOUNDARY AND OVER THE BRUSH COUNTRY AS ACTIVITY MOVES IN FROM THE WEST. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 81 74 81 74 85 / 70 60 40 50 50 VICTORIA 80 70 81 72 84 / 70 60 50 50 50 LAREDO 82 71 84 71 88 / 80 70 60 60 50 ALICE 82 72 83 72 87 / 70 60 40 60 50 ROCKPORT 80 75 80 74 83 / 70 60 40 50 50 COTULLA 78 69 83 70 88 / 90 80 70 60 50 KINGSVILLE 83 73 83 73 87 / 70 60 40 50 50 NAVY CORPUS 80 75 80 75 83 / 70 60 40 50 50 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE FOLLOWING ZONES: BEE...DUVAL...GOLIAD...LA SALLE...LIVE OAK... MCMULLEN...VICTORIA...WEBB. GM...NONE. && $$ TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS LINCOLN IL
943 AM CDT TUE MAY 12 2015 .UPDATE... ISSUED AT 943 AM CDT TUE MAY 12 2015 MAIN STRATOCUMULUS SHIELD BASICALLY MADE IT DOWN TO THE I-74 CORRIDOR WITH SOME SCATTERED CLOUDS AS FAR SOUTH AS MATTOON AND LAWRENCEVILLE...BUT THESE SHOULD CONTINUE TO PULL BACK NORTHWARD THROUGH MIDDAY. HOWEVER...LATEST RAP GUIDANCE SUGGESTS THE CLOUDS HOLDING ON A BIT LONGER AROUND CHAMPAIGN AND DANVILLE. CURRENTLY SEEING SOME WIND GUSTS OF 25-30 MPH...WHICH SHOULD CONTINUE INTO MID AFTERNOON. TEMPERATURES CURRENTLY ON TRACK AND ONLY REQUIRED SOME MINOR TWEAKS. UPDATES TO THE ZONES/GRIDS WERE MAINLY DONE FOR THE SKY COVER AND WIND TRENDS. && .SHORT TERM...(TODAY) ISSUED AT 329 AM CDT TUE MAY 12 2015 07Z/2AM SURFACE ANALYSIS SHOWS 1001MB LOW OVER THE NORTHERN GREAT LAKES WHILE A 1025MB HIGH BUILDS INTO THE CENTRAL PLAINS. PRESSURE GRADIENT BETWEEN THESE TWO FEATURES WILL REMAIN TIGHT ENOUGH TO PRODUCE BRISK WESTERLY WINDS ACROSS CENTRAL ILLINOIS TODAY. SUSTAINED WINDS WILL GENERALLY BE IN THE 10 TO 15 MPH RANGE...BUT GUSTS COULD REACH 25 TO 30 MPH AS MIXING TAKES PLACE LATER THIS MORNING. LATEST VWP NETWORK SHOWS 925MB WINDS OF 40 TO 45 MPH AND THINK SOME OF THIS HIGHER MOMENTUM AIR WILL GET MIXED DOWN TO THE SURFACE ONCE MORNING INVERSION IS BROKEN. PRESSURE GRADIENT WILL TEND TO RELAX AS THE DAY PROGRESSES...SO GUSTS WILL BEGIN TO SLOWLY SUBSIDE BY MID-AFTERNOON. LOW CLOUDS CURRENTLY ALONG/NORTH OF A RUSHVILLE TO BLOOMINGTON LINE WILL LIFT NORTHEASTWARD AND CLEAR OUT OF THE AREA BY MID-MORNING...FOLLOWED BY MOSTLY SUNNY SKIES ACROSS THE BOARD FOR THE REMAINDER OF THE DAY. AFTERNOON HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS...WITH READINGS ONLY RISING INTO THE LOWER TO MIDDLE 60S. .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 329 AM CDT TUE MAY 12 2015 HIGH PRESSURE WILL BUILD EASTWARD INTO THE MIDWEST TONIGHT...WITH THE RIDGE AXIS EXPECTED TO BE POSITIONED RIGHT OVER ILLINOIS BY 12Z WED. CLEAR SKIES AND LIGHT WINDS BENEATH THE RIDGE WILL ALLOW EXCELLENT RADIATIONAL COOLING OF THE DRY AIRMASS TO TAKE PLACE...RESULTING IN OVERNIGHT LOW TEMPERATURES IN THE LOWER TO MIDDLE 40S. MAY EVEN SEE A FEW UPPER 30S IN FAVORED LOW-LYING RURAL AREAS. THE HIGH WILL BEGIN TO SHIFT OFF TO THE EAST ON WEDNESDAY...HOWEVER LOW-LEVEL FLOW WILL MAINTAIN A DISTINCT EASTERLY COMPONENT. AS A RESULT...HIGH TEMPERATURES WILL REMAIN ON THE COOL SIDE IN THE UPPER 60S TO AROUND 70 DEGREES. UPPER HEIGHTS BEGIN TO RISE SIGNIFICANTLY BY THURSDAY AS DEEP UPPER LOW OVER THE GULF OF ALASKA DROPS SOUTHEASTWARD AND REACHES THE CALIFORNIA COAST...RESULTING IN DOWNSTREAM RIDGING ACROSS THE CENTRAL AND EASTERN CONUS. A WEAK DISTURBANCE NOTED ON LATEST WATER VAPOR IMAGERY OFF THE COAST OF SOUTHERN CALIFORNIA WILL GET EJECTED NORTHEASTWARD BY THE DIGGING WEST COAST TROUGH...WITH THIS FEATURE TRACKING INTO THE GREAT LAKES BY FRIDAY. MODELS ARE IN GOOD AGREEMENT WITH THE TRACK AND TIMING OF THIS WAVE...WITH SOME MINOR DISCREPANCIES ON HOW QUICKLY TO SPREAD PRECIP INTO ILLINOIS. GIVEN INITIALLY VERY DRY AIRMASS IN PLACE BENEATH THE SURFACE HIGH...PREFER A SLOWER ARRIVAL OF PRECIP. AS A RESULT...HAVE GONE WITH A DRY FORECAST THROUGH THURSDAY MORNING EAST OF I-55 WITH LOW CHANCE POPS DELAYED UNTIL AFTERNOON. FURTHER WEST...RAIN CHANCES WILL INCREASE TO LIKELY ACROSS THE ILLINOIS RIVER VALLEY BY AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS MUCH OF THE AREA THURSDAY NIGHT...WITH THE BEST RAIN CHANCES FOCUSED NORTH OF THE I-70 CORRIDOR. ONCE THE SHORT-WAVE SHIFTS INTO THE GREAT LAKES...FORCING FOR ADDITIONAL PRECIP BECOMES MUCH WEAKER FRIDAY AND SATURDAY. SEVERAL MODELS ARE HINTING THAT ANOTHER WEAK WAVE EMBEDDED WITHIN THE SOUTHWESTERLY FLOW MAY ENHANCE SHOWERS ACROSS SOUTHERN ILLINOIS INTO THE OHIO RIVER VALLEY...HOWEVER VERY LITTLE FOCUS FOR ORGANIZED CONVECTION EXISTS FURTHER NORTH ACROSS THE REMAINDER OF THE AREA. AS A RESULT...WILL ONLY CARRY LOW CHANCE POPS THROUGH THE PERIOD. DEEP UPPER LOW OVER CALIFORNIA WILL GRADUALLY EJECT NORTHEASTWARD LATE IN THE WEEKEND. MODELS ARE IN GOOD AGREEMENT WITH THIS PROCESS THROUGH 144 HOURS...THEN SOLUTIONS BEGIN TO DIVERGE AFTER THAT. BOTH THE GFS AND ECMWF SHOW THE LOW TRACKING INTO THE DAKOTAS BY SUNDAY EVENING...WITH CONVECTION DEVELOPING ALONG A TRAILING COLD FRONT ACROSS THE PLAINS. THE ECMWF THEN BECOMES MORE PROGRESSIVE WITH THE WAVE...AS IT OPENS UP AND PUSHES EASTWARD INTO THE NORTHERN GREAT LAKES BY MONDAY. MEANWHILE...THE GFS KEEPS THE LOW CLOSED LONGER AND IS THUS SLOWER WITH ITS EASTWARD TRACK. THIS MAKES A BIG DIFFERENCE WITH TIMING OF ASSOCIATED COLD FRONT...AS GFS LINGERS THIS BOUNDARY AND RAIN CHANCES UNTIL TUESDAY. SINCE OVERALL SYNOPTIC PATTERN HAS BEEN PROGRESSIVE OVER THE PAST WEEK AND THE GEM SUPPORTS THE ECMWF...WILL BE GOING WITH THE FASTER ECMWF/GEM SOLUTION IN THE EXTENDED. AS A RESULT...WILL BRING LIKELY POPS INTO THE FAR WESTERN CWA SUNDAY AFTERNOON...THEN FURTHER EAST ACROSS THE REMAINDER OF THE AREA SUNDAY NIGHT. WILL THEN BEGIN TO SHIFT THE RAIN CHANCES OUT OF THE PICTURE ON MONDAY...WITH DRY WEATHER RETURNING MONDAY NIGHT AND TUESDAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 600 AM CDT TUE MAY 12 2015 VFR CIGS EXPECTED TO PUSH OFF TO OUR EAST THIS MORNING BASED ON CURRENT TRENDS IN SATELLITE DATA AND LATEST FORECAST SOUNDINGS. CIG BASES HAVE BEEN FROM 3500 TO 4500 FEET WITH SOME LOWER...MVFR CIGS...NOTED TO OUR NORTHWEST AND NORTH. THOSE ARE EXPECTED TO REMAIN JUST TO THE NORTH OF PIA AND BMI THIS MORNING. SPI...DEC AND CMI HAVE BEEN RIGHT ON THE EDGE OF THE VFR CIGS AND EXPECT THOSE AREAS TO SEE SOME SCT-BKN CIGS FOR A TIME THIS MORNING WITH THE MAIN AREA OF OVR CIGS TO THE NORTH. GUSTY WINDS WILL CONTINUE TODAY WITH FORECAST SOUNDINGS SUGGESTING WIND GUSTS TO AROUND 25 KTS AT TIMES OUT OF THE WEST AND THEN NORTHWEST THIS AFTERNOON. LOOK FOR THE WINDS TO RAPIDLY DIMINISH JUST AFTER SUNSET AS HIGH PRESSURE SETTLES IN OVERNIGHT WITH VFR CONDITIONS CONTINUING. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEELHART SHORT TERM...BARNES LONG TERM...BARNES AVIATION...SMITH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
630 AM CDT TUE MAY 12 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 359 AM CDT TUE MAY 12 2015 HIGH PRESSURE CENTERED ACROSS KS MOVES EAST INTO MISSOURI TODAY. LOW PRESSURE WILL BEGIN TO ORGANIZE ACROSS THE NRN HIGH PLAINS THIS AFTERNOON. THE MODEL CONSENSUS SHOWS STRONG RETURN FLOW DEVELOPING THIS AFTERNOON WITH SOUTH WINDS INCREASING TO 20 TO 30 MPH ACROSS WRN NEB. THESE WINDS SHOULD CONTINUE TONIGHT AS THE LOW LEVEL JET FORMS AND STRENGTHENS TO AROUND 50 KT. THE TEMPERATURE FORECAST TODAY FOLLOWS THE WARMER SIDE OF THE MODEL CONSENSUS. SEVERAL MODELS WERE VERY COLD WITH HIGHS IN THE 60S WHILE THE RAP WAS VERY WARM WITH HIGHS IN THE UPPER 70S. THE FORECAST IS FOR HIGHS IN THE UPPER 60S TO MID 70S. LOWS TONIGHT FALL INTO THE UPPER 40S TO AROUND 50. SOUTH WINDS AT 15 TO 20 MPH SHOULD KEEPS LOWS MILD. LASTLY...THE MODELS SHOW A WEAK DISTURBANCE FIRING THUNDERSTORMS ON THE LARAMIE AND FRONT RANGES LATE THIS AFTERNOON AROUND 21Z WHICH CARRY EAST TOWARD WESTERN NEBRASKA. THE BEST GUESS IS FOR ISOLATED SPRINKLES THIS EVENING. THE GFS WAS THE WET MODEL WHICH ACTUALLY SHOWS SOME MEASURABLE QPF. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 359 AM CDT TUE MAY 12 2015 MODELS CONTINUE TO ADVERTISE A RAPID RETURN OF GULF MOISTURE TAKING PLACE WEDNESDAY...WITH MODELS PROJECTING 850 MB DEW POINTS IN THE 10 TO 12C RANGE BY WEDNESDAY EVENING ACROSS THE REGION. A LARGE UPPER TROUGH WILL BE TAKING SHAPE ALONG THE WEST COAST MID TO LATE WEEK...WITH A LEAD SHORTWAVE EJECTING NORTHEAST THROUGH THE PLAINS AHEAD OF THE TROUGH WEDNESDAY NIGHT INTO THURSDAY. THIS SYSTEM IS SHOWN TO HAVE SOMEWHAT OF A NEGATIVE TILT...WHICH WILL HELP DRAW MOISTURE WESTWARD INTO THE HIGH PLAINS. THE COMBINATION OF STRONG LIFT AND MOISTURE TRANSPORT ON A SOUTHERLY LOW LEVEL JET...CONTINUES TO GIVE CONFIDENCE THAT PRECIPITATION SHOULD RESULT LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. WILL MAINTAIN THE LIKELY POPS ALONG AND EAST OF HIGHWAY 83 WEDNESDAY NIGHT...AND ALSO INTRODUCE EVENING LIKELY POPS ALONG A SURFACE TROUGH ACROSS THE PANHANDLE INTO THE WESTERN SANDHILLS. THE LEAD WAVE QUICKLY PASSES AND MOVES NORTHEAST AWAY FROM THE AREA THURSDAY. ATTENTION THEN TURNS TO THE LONG WAVE TROUGH ALONG THE WEST COAST. MODELS/ENSEMBLES PROJECT THIS TO MOVE EAST AS A CLOSED SYSTEM DURING THE WEEKEND. THE GENERAL CONSENSUS IN THE MODELS AND ENSEMBLE MEAN IS FOR THE CENTER OF THE SYSTEM TO TRACK ACROSS WYOMING INTO SOUTH DAKOTA. THIS PUTS OUR AREA IN THE WARM MOIST SECTOR. INSTABILITY LOOKS TO BE STRONG...AND AS DEEP LAYER SHEAR INCREASES...STRONG TO SEVERE STORMS WILL LIKELY RESULT. WILL INTRODUCE THE POTENTIAL FOR SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER OUTLOOK FOR FRIDAY AND SATURDAY. THE GFS AND ECMWF CONTINUE TO DIFFER SOMEWHAT ON THE LOW LEVEL BOUNDARY PLACEMENT...BUT THE LATEST TREND IS TO HOLD THE DRY LINE BACK TO THE WEST ACROSS WESTERN NEBRASKA INTO WESTERN KANSAS...WHICH WOULD PLACE SEVERE STORM DEVELOPMENT ACROSS THE FORECAST AREA OF WESTERN AND NORTH CENTRAL NEBRASKA. WE WILL LIKELY BE IN THE MIDST OF THE MID LEVEL DRY SLOT SUNDAY AS THE STORM SYSTEM CROSSES THE DAKOTAS...BUT AT LEAST SOME CHANCE FOR SHOWERS IN WRAP AROUND PATTERN ACROSS NORTHERN NEBRASKA. DRY WEATHER FOR MONDAY...THEN MORE CHANCES FOR RAIN NEXT WEEK BEYOND THE FORECAST PERIOD...AS THE NEXT DEEP TROUGH MOVES EAST INTO THE WESTERN CONUS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 630 AM CDT TUE MAY 12 2015 VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT. STRONG SOUTH WINDS DEVELOP TODAY INCREASING TO 18020G32KT. ISOLATED TSTMS ARE EXPECTED ACROSS THE LARAMIE AND COLORADO FRONT RANGES AOA 21Z THIS AFTN. THERE IS A SLIGHT CHANCE THESE STORMS COULD REACH WRN NEB THIS EVENING IN THE FORM OF -SHRA/SPRINKLES. && .HYDROLOGY... ISSUED AT 359 AM CDT TUE MAY 12 2015 THE COMBINATION OF SEASONAL SNOW MELT IN THE UPPER SOUTH PLATTE RIVER BASIN AND RECENT HEAVY PRECIPITATION OVER WESTERN NEBRASKA AND NORTHEAST COLORADO WILL LEAD TO FLOODING ON THE SOUTH PLATTE AND PLATTE RIVERS IN SOUTHWEST NEBRASKA LATER THIS WEEK AND INTO EARLY NEXT WEEK. AT THIS TIME SOME UNCERTAINTY STILL REMAINS WITH THE FORECAST AS KEY UPSTREAM GAUGES IN NORTHEAST COLORADO HAVE YET TO CREST. HOWEVER...LATEST PROJECTIONS CONTINUE TO HIGHLIGHT AN INCREASING THREAT FOR SIGNIFICANT FLOODING TO OCCUR...POTENTIALLY NEAR SEPTEMBER 2013 FLOOD LEVELS. RIVER STAGE FORECASTS WILL BE CLOSELY MONITORED AND UPDATED ONCE MORE UPSTREAM RIVER DATA BECOMES AVAILABLE. PERSONS THAT LIVE IN VULNERABLE AREAS ALONG THE SOUTH PLATTE RIVER AND PLATTE RIVER IN SOUTHWEST NEBRASKA SHOULD PAY CLOSE ATTENTION TO FLOOD FORECASTS IN THE COMING DAYS AND BE PREPARED TO TAKE PROPER ACTION. && .LBF WATCHES/WARNINGS/ADVISORIES... FROST ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR NEZ006>010-026>029-038-058-059-069>071. FREEZE WARNING UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR NEZ004- 005-022>025-035>037-056-057-094. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...CDC HYDROLOGY...MARTIN/TAYLOR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1049 AM EDT TUE MAY 12 2015 .SYNOPSIS... SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AHEAD OF A COLD FRONT. LESS HUMID AIR ARRIVES ON WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH PRESSURE MOVES OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...HOT AND HUMID DAY ONGOING ACROSS THE CWA EVEN AT THIS EARLY HOUR. AFTER STARTING FROM LOWS AROUND 70...TEMPS ARE SHOOTING UP QUICKLY THIS MORNING THANKS TO 950MB TEMPS CLOSE TO 22C ON THE 8AM KCHS U/A SOUNDING. HIGH PRESSURE CENTERED WELL OFFSHORE IS PUMPING RETURN FLOW INTO THE CAROLINAS...WHICH IS STRENGTHENING WARM ADVECTION IN A PRE-FRONTAL AIRMASS. THE COMBINATION OF THIS HEAT AND DEWPOINT TEMPS AROUND 70 WILL DRIVE HEAT INDICES INTO THE MID 90S AWAY FROM THE COAST TODAY...THE MOST UNCOMFORTABLE DAY OF 2015 SO FAR. THIS HUMID AIR MASS WILL DRIVE INSTABILITY THIS AFTN...AND CONVECTION IS ONCE AGAIN EXPECTED ACROSS THE AREA. VERY STEEP LR`S UP TO 800MB WILL DRIVE RAPID UPDRAFTS...AND SBCAPE IS FORECAST TO RISE TO AROUND 3000 J/KG...POSSIBLY HIGHER RIGHT ALONG THE SEA BREEZE. THIS WILL SERVE AS THE FUEL FOR STORMS TODAY...WHICH SHOULD DEVELOP ALONG THE SEA BREEZE...AND THEN LATER ALONG A PRE-FRONTAL TROUGH APPROACHING FROM THE WEST. WHILE RESIDUAL BOUNDARIES MAY FIRE WEAK STORMS...MID LEVEL TEMPS ARE NOT EXCEEDINGLY COOL (-8C AT 500MB) SO WIDESPREAD STRONG UPDRAFTS ARE NOT ANTICIPATED. STILL...ENOUGH FORCING WILL DRIVE PARCELS UP INTO DECENT HAIL-ZONE INSTABILITY...AND AN INVERTED-V TYPE SIGNATURE IS PROGGED WELL INLAND AHEAD OF THE PRE-FRONTAL TROUGH. BULK-SHEAR VALUES STRUGGLE TO AROUND 20 KTS...SO WIDESPREAD STORM ORGANIZATION IS UNLIKELY...BUT PULSE STORMS AND AT LEAST SOME LINEAR FEATURES ALONG THE PRE-FRONTAL TROUGH WILL HAVE THE POTENTIAL TO PRODUCE AN ISOLATED WIND GUST OR LARGE HAIL STONE THIS AFTN. HIGH-RES HRRR AND NSSL WRF SUGGEST ONLY ISOLATED STORMS UNTIL THE PRE-FRONTAL TROUGH THIS EVENING...WHICH WILL BE THE PRIMARY DRIVER OF CONVECTION TODAY. BY THIS EVENING HOWEVER...WE BEGIN TO LOSE HEATING...AND HAVE CAPPED POP IN THE HIGH CHC RANGE. HIGHEST PROBABILITY FOR STORMS LOOKS TO BE ACROSS THE MIDDLE-PART OF THE CWA WHERE THE WESTWARD ADVANCING SEA BREEZE WILL INTERACT WITH THE EASTWARD MOVING TROUGH. CONVECTION WILL WANE AFTER DARK...AND LITTLE FANFARE IS EXPECTED WITH THE ACTUAL FROPA TONIGHT. HOWEVER...A SIGNIFICANT AIRMASS CHANGE WILL ACCOMPANY THIS FRONT...WITH MUCH DRIER AIR AND LOWS DROPPING INTO THE MID 60S AT THE COAST...AROUND 60 WELL INLAND. ALSO NEED TO NOTE A PERSISTENT AREA OF SEA-STRATUS FROM ABOUT NORTH MYRTLE BEACH TO BALD HEAD ISLAND. SHELF WATERS MUST BE JUST COOL ENOUGH TO TAP INTO THE IDEALIZED RESIDENCE PARCEL TIMES ENCOUNTERED BY THE W/SW WINDS IN ORDER TO SATURATE IN THIS AREA. THE COMBINATION OF THE BACKING WINDS WITHIN THE SEA BREEZE...AS WELL AS SIGNIFICANT HEATING JUST INLAND...SHOULD BREAK APART THIS STRATUS BY EARLY AFTN...BUT IT IS UNLIKELY THE NEAR-COAST AREA HERE WILL EXPERIENCE THE HOT/HUMID/SUNNY DAY GOING ON ELSEWHERE ACROSS THE CWA. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY... SOME VERY PLEASANT WEATHER EXPECTED THROUGH THE PERIOD. HIGH PRESSURE WELL TO OUR NORTH WILL SHOW LITTLE MOVEMENT WEDNESDAY WHILE THE TUESDAY NIGHT COLD FRONT STALLS WELL TO OUR SOUTH. IN BETWEEN THE TWO WE WILL SEE A N TO NE FLOW LOCALLY THAT WILL BRING SOME MUCH LOWER DEWPOINTS. A MILD LEVEL RIDGE WILL BE JUST TO OUR WEST ALLOWING FOR DEEP LAYER DRY AIR AND AMPLE SUNSHINE. ON THURSDAY THE HIGH WILL MOVE CLOSER TO THE REGION KEEPING TEMPERATURES A BIT BELOW CLIMATOLOGY. A LITTLE MOISTURE RETURN MAY GET UNDERWAY THURSDAY NIGHT AS THE HIGH MOVES FURTHER TO THE EAST, MAINLY OVER WESTERN ZONE. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...RETURN FLOW ON FRIDAY AND SATURDAY AS HIGH PRESSURE SITES OFF THE COAST. THE MID LEVEL RIDGE WILL BE OVERHEAD HOWEVER PRECLUDING DEEP MOISTURE AND CONFINING IT TO THE LOWER LEVELS. SO WHILE A STRAY SHOWER OR THUNDERSTORM CANNOT BE RULED OUT ANY COVERAGE SHOULD BE MINIMAL. OVER THE WEEKEND AND EVEN INTO MONDAY FOR THAT MATTER THE MID LEVEL RIDGING APPEARS TO RESURGE. DESPITE THIS THE GFS AND ECMWF BOTH DEPICT AN INCREASE IN PRECIPITATION COVERAGE. WHILE THE CONTINUED MOISTENING OF THE LOW LEVELS DOES IN FACT ARGUE FOR THIS THE MID LEVEL DRYNESS PROBABLY MEANS THAT ITS RATHER SUBTLE. TEMPERATURES MEANWHILE WILL GROW WARMER EACH DAY AND NIGHT. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...RETURN FLOW ON FRIDAY AND SATURDAY AS HIGH PRESSURE SITES OFF THE COAST. THE MID LEVEL RIDGE WILL BE OVERHEAD HOWEVER PRECLUDING DEEP MOISTURE AND CONFINING IT TO THE LOWER LEVELS. SO WHILE A STRAY SHOWER OR THUNDERSTORM CANNOT BE RULED OUT ANY COVERAGE SHOULD BE MINIMAL. OVER THE WEEKEND AND EVEN INTO MONDAY FOR THAT MATTER THE MID LEVEL RIDGING APPEARS TO RESURGE. DESPITE THIS THE GFS AND ECMWF BOTH DEPICT AN INCREASE IN PRECIPITATION COVERAGE. WHILE THE CONTINUED MOISTENING OF THE LOW LEVELS DOES IN FACT ARGUE FOR THIS THE MID LEVEL DRYNESS PROBABLY MEANS THAT ITS RATHER SUBTLE. TEMPERATURES MEANWHILE WILL GROW WARMER EACH DAY AND NIGHT. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 12Z...MID/HIGH CLOUDS ARE DECREASING FROM NW-SE WITH PATCHY IFR/MVFR CLOUDS MOVING SW-NE. AT KFLO IFR CIGS ARE OCCURRING. AT KCRE IFR/LIFR MARINE STRATUS IS OCCURRING AND MOVING NNE AND LIFTING INTO A MVFR LAYER AT KILM. WINDS ARE SSW 4-10 KTS. EXPECT LITTLE CHANGE OVER THE NEXT COUPLE OF HOURS. LOW CIGS WILL GRADUALLY BECOME VFR MID-LATE MORNING AS HEATING BEGINS. THEN THERE IS MODERATE TO HIGH CONFIDENCE VFR WILL PERSIST FOR THE REMAINDER OF THE TAF VALID PERIOD. A COLD FRONT WILL APPROACH AND MOVE THROUGH THE TERMINALS THIS TAF PERIOD. WINDS WILL INCREASE THIS MORNING WITH GUSTS TO AROUND 20KT. IT WILL BE UNSTABLE ENOUGH FOR SHOWERS AND THUNDERSTORMS TO DEVELOP. APPEARS MOST WILL DEVELOP BETWEEN THE INLAND AND COASTAL TERMINALS. WILL INDICATE VCSH IN TAFS AND AMEND LATER IF NECESSARY. CONVECTION SHOULD TAPER OFF IN THE EVENING. THE COLD FRONT WILL MOVE THROUGH DURING THE LATE EVENING AND OVERNIGHT HOURS. EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...HIGH PRESSURE OFFSHORE IS THE DOMINANT SYNOPTIC FEATURE ACROSS THE WATERS TODAY...DRIVING SW FLOW AND WINDS OF 10-15 KTS ACROSS THE WATERS. LOCAL ENHANCEMENTS OF UP TO 20 KTS...ALONG WITH A BACKING IN DIRECTION TO THE SOUTH...IS LIKELY ALONG THE SEA BREEZE THROUGH THE AFTN AS WELL. OTHER THAN SOME CHOPPY WATERS WITHIN THE NEAR SHORE WATERS THANKS TO THE SEA BREEZE...WAVE HEIGHTS ARE EXPECTED TO PERSIST AT 2-4 FT WITH A 6-7 SEC PERIOD DOMINANT. A COLD FRONT WILL CROSS THE WATERS LATE TONIGHT TURNING WINDS TO THE N/NW AT AROUND 15 KTS...AND PUSHING THE HIGHEST SEAS AWAY FROM THE COAST. SHORT TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 3 AM TUESDAY... TUESDAY NIGHT`S FROPA WILL BRING A NORTHERLY FLOW ON WEDNESDAY. SURFACE HIGH REMAINS UP IN THE GREAT LAKES SO THE FLOW WILL BE QUITE LIGHT LOCALLY AND SEAS LIKELY JUST 2 TO 3 FT. JUST A SLIGHT VEER WEDNESDAY NIGHT WITH FLOW POSSIBLY GOING LIGHT AND VARIABLE FOR A TIME. THE HIGH EXTENDS JUST SLIGHTLY SOUTH ON THURSDAY WHILE PROGRESSING EAST. NE WINDS COULD INCREASE BY A CATEGORY AND BECOME A LITTLE GUSTY. THE COAST- PARALLEL FLOW WILL PRECLUDE MUCH BUILDING OF SEAS HOWEVER. .LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY... THE HIGH TO OUR NORTH PROGRESSES FURTHER EAST ON FRIDAY LEADING TO MORE VEERING LOCALLY. FRIDAY MAY SEE ONSHORE/EASTERLY FLOW MOST OF THE DAY WHILE A SOUTHERLY COMPONENT TRIES TO GET ESTABLISHED MAINLY OVER SOUTHERN ZONES. ON SATURDAY WE TRANSITION TO A FAIRLY NORMAL RETURN FLOW AROUND HIGH PRESSURE OFF THE EAST COAST. NOT A BERMUDA HIGH THOUGH WHICH TYPICALLY BRINGS SOUTHWESTERLY FLOW...THE WEEKEND WILL LIKELY SEE SOUTHEAST INSTEAD. THERE COULD BE A VERY GRADUAL INCREASE IN WAVE PERIOD AS A SWELL BECOMES ESTABLISHED. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...JDW SHORT TERM...MBB LONG TERM...MBB AVIATION...MRR MARINE...JDW/MBB
AREA FORECAST DISCUSSION
NWS NORMAN OK
1100 AM CDT TUE MAY 12 2015 .UPDATE... ADJUSTMENTS TO CLOUD COVER AND TEMPERATURES. && .DISCUSSION... ALTHOUGH MID-HIGH CLOUDS WILL THIN SOMEWHAT FROM WEST TO EAST THROUGH THE AFTERNOON...MOST AREAS OUTSIDE OF FAR NORTH/WEST OKLAHOMA WILL STAY MOSTLY CLOUDY TODAY AND WILL KEEP TEMPS FROM GETTING TOO WARM. INCREASED CLOUD COVER AND LOWERED HIGHS A FEW DEGREES NEAR AND SOUTH OF OKC. A FEW SPRINKLES MAY MOVE INTO WESTERN NORTH TEXAS THIS AFTERNOON BUT MAIN RAIN EVENT STILL APPEARS TO COMMENCE AFTER MIDNIGHT TONIGHT AND MAINLY DURING THE DAY TOMORROW. FLASH FLOOD WATCH WILL BE CONTINUED FOR LATE TONIGHT AND TOMORROW. LATEST RUN OF MODELS LOOKS FAVORABLE FOR HEAVIER RAIN AXIS TO BE FARTHER WEST...SOME OF WHICH WILL BE JUST OUTSIDE OF CURRENT WATCH. HOWEVER...AREAS WEST OF THE FLASH FLOOD WATCH CAN TAKE MUCH MORE RAIN THAN THE RAIN SOAKED CENTRAL/SOUTHEAST OKLAHOMA. WE WILL TAKE A CLOSER LOOK TO EXPANDING THE WATCH BUT IT WILL NOT BE DONE WITH THIS UPDATE. ALTHOUGH SEVERE WEATHER DOES LOOK POSSIBLE FRIDAY...STILL APPEARS THAT SATURDAY COULD BE THE PRIMARY IMPACT DAY FOR SEVERE WEATHER. && .PREV DISCUSSION... /ISSUED 615 AM CDT TUE MAY 12 2015/ AVIATION... 12Z TAFS...THIN BAND OF SHOWERS AND EMBEDDED STORMS ACROSS CENTRAL AND WEST TEXAS IS EXPECTED TO REMAIN SOUTH OF TAF SITES THROUGH THE DAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH 6Z...BEFORE CEILINGS LOWER ACROSS WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA AS PRECIPITATION DEVELOPS. PREV DISCUSSION... /ISSUED 325 AM CDT TUE MAY 12 2015/ DISCUSSION... EAST TO SOUTHEAST WINDS WILL DEVELOP TODAY AS SURFACE HIGH PRESSURE OVER KANSAS BUILDS EAST. MEANWHILE...CONVECTION ALONG THE EAST TEXAS COAST WILL DELAY THE RETURN OF DEEP MOISTURE NORTHWARD. SCATTERED SHOWERS AND A FEW STORMS HAVE FORMED WITHIN AN AREA OF MID-LEVEL MOISTURE RETURN OVER CENTRAL AND WEST TEXAS. THE HRRR SORTA HAS A HANDLE ON THIS AND GRADUALLY WEAKENS IT DURING THE MORNING...WHILE THE NAM12 IS MORE AGGRESSIVE IN DEVELOPING CONVECTION IN WESTERN NORTH TEXAS. FOR NOW WILL KEEP IN CHANCE POPS FOR OUR TEXAS COUNTIES. ANOTHER HEAVY RAIN EVENT SEEMS LIKELY LATE TUESDAY NIGHT INTO WEDNESDAY. MODELS ARE SIMILAR IN TRACKING A PROGRESSIVE TROUGH ACROSS THE SOUTHWESTERN STATES TONIGHT AND THEN OVER WEST TEXAS AND OKLAHOMA WEDNESDAY INTO EARLY THURSDAY. DEEP MOISTURE IN PLACE OVER SOUTH TEXAS WILL BE TRANSPORTED NORTHWARD TONIGHT INTO WEDNESDAY IN ADVANCE OF THE TROUGH. THE BEST COMBINATION OF UPPER AND LOW LEVEL JET FEATURES...SHOULD FOCUS THE HEAVIEST RAIN OVER WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA EARLY WEDNESDAY...WITH A GRADUALLY SHIFT NORTH AND EAST DURING THE AFTERNOON AND NIGHT. WIDESPREAD 2 INCH RAIN AMOUNTS ARE LIKELY WITH 3 TO 4 INCH TOTALS POSSIBLE. WITH RECENT HEAVY RAIN OVER THE SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS...FLOODING WILL AGAIN BE A CONCERN. BRIEF SHORTWAVE RIDGING ON THURSDAY WILL KEEP RAIN CHANCES LOW...BUT ANOTHER TROUGH WILL BEGIN TO SHIFT EASTWARD FRIDAY INTO THE WEEKEND. BETTER INSTABILITY IS EXPECTED TO DEVELOP AHEAD OF THIS SYSTEM WHICH WILL RESULT IN AN INCREASE IN SEVERE WEATHER CHANCES FRIDAY INTO SATURDAY. ANOTHER FRONT IS EXPECTED TO PUSH ACROSS THE SOUTHERN PLAINS SUNDAY INTO MONDAY WHICH WILL BRING ANOTHER PERIOD OF DRY WEATHER. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 70 56 67 62 / 0 30 100 100 HOBART OK 71 56 67 61 / 0 40 100 70 WICHITA FALLS TX 71 59 70 64 / 10 60 100 70 GAGE OK 70 53 66 56 / 0 20 80 60 PONCA CITY OK 71 53 66 59 / 0 10 70 100 DURANT OK 72 59 71 64 / 10 40 80 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR OKZ007-008-012-013-017>020-022>048-050>052. TX...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR TXZ083>090. && $$ 11/84
AREA FORECAST DISCUSSION
NWS NORMAN OK
615 AM CDT TUE MAY 12 2015 .AVIATION... 12Z TAFS...THIN BAND OF SHOWERS AND EMBEDDED STORMS ACROSS CENTRAL AND WEST TEXAS IS EXPECTED TO REMAIN SOUTH OF TAF SITES THROUGH THE DAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH 6Z...BEFORE CEILINGS LOWER ACROSS WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA AS PRECIPITATION DEVELOPS. && .PREV DISCUSSION... /ISSUED 325 AM CDT TUE MAY 12 2015/ DISCUSSION... EAST TO SOUTHEAST WINDS WILL DEVELOP TODAY AS SURFACE HIGH PRESSURE OVER KANSAS BUILDS EAST. MEANWHILE...CONVECTION ALONG THE EAST TEXAS COAST WILL DELAY THE RETURN OF DEEP MOISTURE NORTHWARD. SCATTERED SHOWERS AND A FEW STORMS HAVE FORMED WITHIN AN AREA OF MID-LEVEL MOISTURE RETURN OVER CENTRAL AND WEST TEXAS. THE HRRR SORTA HAS A HANDLE ON THIS AND GRADUALLY WEAKENS IT DURING THE MORNING...WHILE THE NAM12 IS MORE AGGRESSIVE IN DEVELOPING CONVECTION IN WESTERN NORTH TEXAS. FOR NOW WILL KEEP IN CHANCE POPS FOR OUR TEXAS COUNTIES. ANOTHER HEAVY RAIN EVENT SEEMS LIKELY LATE TUESDAY NIGHT INTO WEDNESDAY. MODELS ARE SIMILAR IN TRACKING A PROGRESSIVE TROUGH ACROSS THE SOUTHWESTERN STATES TONIGHT AND THEN OVER WEST TEXAS AND OKLAHOMA WEDNESDAY INTO EARLY THURSDAY. DEEP MOISTURE IN PLACE OVER SOUTH TEXAS WILL BE TRANSPORTED NORTHWARD TONIGHT INTO WEDNESDAY IN ADVANCE OF THE TROUGH. THE BEST COMBINATION OF UPPER AND LOW LEVEL JET FEATURES...SHOULD FOCUS THE HEAVIEST RAIN OVER WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA EARLY WEDNESDAY...WITH A GRADUALLY SHIFT NORTH AND EAST DURING THE AFTERNOON AND NIGHT. WIDESPREAD 2 INCH RAIN AMOUNTS ARE LIKELY WITH 3 TO 4 INCH TOTALS POSSIBLE. WITH RECENT HEAVY RAIN OVER THE SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS...FLOODING WILL AGAIN BE A CONCERN. BRIEF SHORTWAVE RIDGING ON THURSDAY WILL KEEP RAIN CHANCES LOW...BUT ANOTHER TROUGH WILL BEGIN TO SHIFT EASTWARD FRIDAY INTO THE WEEKEND. BETTER INSTABILITY IS EXPECTED TO DEVELOP AHEAD OF THIS SYSTEM WHICH WILL RESULT IN AN INCREASE IN SEVERE WEATHER CHANCES FRIDAY INTO SATURDAY. ANOTHER FRONT IS EXPECTED TO PUSH ACROSS THE SOUTHERN PLAINS SUNDAY INTO MONDAY WHICH WILL BRING ANOTHER PERIOD OF DRY WEATHER. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 71 56 67 62 / 0 30 80 80 HOBART OK 71 56 67 61 / 0 40 90 70 WICHITA FALLS TX 72 59 70 64 / 10 60 90 70 GAGE OK 71 53 66 56 / 0 20 70 60 PONCA CITY OK 72 53 66 59 / 0 10 70 90 DURANT OK 73 59 71 64 / 10 40 80 70 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR OKZ007-008-012-013-017>020-022>048-050>052. TX...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR TXZ083>090. && $$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1136 AM EDT TUE MAY 12 2015 .SYNOPSIS... OUR RECENT STRING OF WARM DAYS AND MILD NIGHTS WILL BE CUT TODAY AS A STRONG COLD FRONT PUSHES EAST ACROSS THE STATE. COOLER... DRIER AND WINDY CONDITIONS WILL ARRIVE DURING THE DAYLIGHT HOURS TODAY...AND LAST THROUGH WEDNESDAY NIGHT. A LARGE AREA OF HIGH PRESSURE WILL BECOME CENTERED OVER THE STATE WEDNESDAY NIGHT AND EARLY THURSDAY. AS THE HIGH DRIFTS EAST AND OFF THE MID ATLANTIC COAST...MILDER CONDITIONS WILL RETURN FOR THURSDAY AND FRIDAY AND CONTINUE THIS WEEKEND AS ANOTHER UPPER RIDGE BUILDS ACROSS THE REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... COLD FRONT TRACKING ACROSS CENTRAL PA LATE THIS MORNING... DELINEATED BY LINE OF SHALLOW CONVECTION. KBFD JUST HAD A PEAK WIND OF 32 KTS AS THIS BAND MOVED ACROSS...IN LINE WITH PREVIOUS EXPECTATIONS. HI RES HRRR AND 4KM SPC WRF AND MODEL SOUNDINGS INDICATE A RIBBON OF A FEW TO SEVERAL HUNDRED J/KG AVAILABLE FOR SHALLOW CONVECTION TO ACCOMPANY ITS PASSAGE ACROSS MOST OF CENTRAL PA. HI RES SIMULATIONS DAMPEN CONVECTION OVER THE LOWER SUSQ LATER TODAY DUE TO INCREASING DOWNSLOPE COMPONENT...BUT WE`LL LIKELY SEE SOME GUSTY SHOWERS WITH ISOLATED THUNDER FOR MUCH OF THE EARLY AFTERNOON AS THE FRONT SLIDES EAST. STRONG COLD ADVECTION AND 30-40 KT 850 MB WINDS WILL INCREASINGLY MIX BY THIS AFTERNOON BEHIND THE FRONT...WITH FREQUENT GUSTS OF 30+ MPH REACHING THE SFC. HIGH TEMPS WILL RANGE FROM THE COOLISH M-U60S NW...TO THE LOWER AND MID 80S IN THE SOUTHEAST /WHICH WILL BE ABOUT 10-12 DEG ABOVE NORMAL FOR TODAY IN THE GREATER HARRISBURG...YORK...LANCASTER AREA/. EXTENSIVE...COLD AIR STRATO CU WILL SPREAD INTO THE WEST THIS AFTERNOON...BUT BREAK UP AND FLATTEN OUT IN THE LLVL DOWNSLOPE AND ADIABATIC WARMING/DRYING REGIME ACROSS THE CENTRAL VALLEYS AND SUSQ REGION. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... DEEPENING NW FLOW...WITH SHALLOW COLD AIR AT LLVLS WILL LEAD TO GENERALLY PARTLY SKIES ACROSS THE SUSQ VALLEY....WITH MOSTLY CLOUD TO CLOUDY CONDITIONS OVER THE MW MTNS. THIS CLOUD DISTRIBUTION WILL HELP TO LESSEN THE NORMAL STRONG NW/SE DIFF IN MIN TEMPS ACROSS THE STATE. LOWS EARLY TUESDAY WILL BE IN THE UPPER 30S TO LOW 40S WEST...AND IN THE U40S TO LOWER 50S THROUGHOUT THE SUSQEHANNA VALLEY && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LATER SHIFTS WILL NEED TO MONITOR THE THREAT FOR FROST OR FREEZE PRODUCTS WED NIGHT AS TEMPS WILL BE PLUMMETING INTO THE U20S/L30S INVOF KBFD...AND MID 30S TO AROUND 40F AS YOU HEAD SE FROM THE I99/RT200 CORRIDOR TWD INTERSTATE 81. LOWS ACROSS THE LOWER SUSQ VALLEY SHOULD BE AOA 40F EARLY THURSDAY. A FEW WEAK SYSTEMS CRESTING THE MEAN EASTERN U.S. UPPER RIDGE AND DROPPING SE FROM THE GLAKES WILL BRING THE CHC OF SOME SHOWERS FRIDAY AFTERNOON THROUGH SAT. UPPER RIDGE SHARPENS OVER THE MID ATLANTIC REGION SAT NIGHT INTO SUNDAY. WASHED OUT FRONT TO THE SOUTH OF THE STATE SAT NIGHT WILL LIKELY RETURN NORTH AS A WARM FRONT SUNDAY...BRINGING BACK THE CHC FOR SHOWERS/SCTD TSRA SUNDAY AFTERNOON INTO EARLY NEXT WEEK AHEAD OF A STRONGER SYSTEM THAT WILL BE GRADUALLY SHEARING OUT AS IT HEADS NE TWD THE GLAKES REGION. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... COLD FRONT AND NARROW BAND OF MVFR CIGS/SHRA WITH SFC WND G35 KTS SPREADING ACROSS NORTHERN AND CENTRAL AIRFIELDS. ASSOC DRIER AIR WILL CAUSE CIGS TO BECOME VFR...EVEN OVR THE W MTNS THIS AFTERNOON. WIDESPREAD VFR CONDS EXPECTED FOR THE BALANCE OF THE DAY...AS DRIER AIR FLOWS IN BEHIND COLD FRONT. MAIN CONCERN LATER TODAY WILL BE THE GUSTY WEST WINDS...RESULTING FROM TIGHT PRESSURE GRADIENT SOUTH OF LOW PRES OVR S QUEBEC. MDL SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS BY THIS AFTN. THE STRONGEST GUSTS WILL DIMINISH AFTER SUNSET...BUT IT WILL REMAIN BREEZY OVERNIGHT. OUTLOOK... WED...NO SIG WX EXPECTED. THU...EARLY AM FOG POSS NW MTNS. FRI...PM SHRA/CIG REDUCTIONS POSS...MAINLY NW MTNS. SAT...SCT PM TSRA IMPACTS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...DEVOIR/LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
613 AM EDT TUE MAY 12 2015 .SYNOPSIS... OUR RECENT STRING OF WARM DAYS AND MILD NIGHTS WILL BE CUT TODAY AS A STRONG COLD FRONT PUSHES EAST ACROSS THE STATE. COOLER... DRIER AND WINDY CONDITIONS WILL ARRIVE DURING THE DAYLIGHT HOURS TODAY...AND LAST THROUGH WEDNESDAY NIGHT. A LARGE AREA OF HIGH PRESSURE WILL BECOME CENTERED OVER THE STATE WEDNESDAY NIGHT AND EARLY THURSDAY. AS THE HIGH DRIFTS EAST AND OFF THE MID ATLANTIC COAST...MILDER CONDITIONS WILL RETURN FOR THURSDAY AND FRIDAY AND CONTINUE THIS WEEKEND AS ANOTHER UPPER RIDGE BUILDS ACROSS THE REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SFC-850 MB NORTH/SOUTH THETA-E RIDGE WAS SLIDING INTO THE EASTERN HALF OF THE STATE AT 09Z...WITH JUST A FEW BRIEF SHOWERS OR SPRINKLES RACING ENE. SFC DEWPOINTS DROPPING OFF BY SEVERAL DEG F ACROSS WESTERN PENN /TO THE WEST OF RT 219/...AND THIS MARKS THE WEAK...INITIAL COLD FRONT THAT WILL SLIDE ACROSS MUCH OF THE FCST AREA BY 12Z. COLD FRONT JUST PUSHED THROUGH KTOL OVER THE PAST HOUR...AND WE/LL HAVE TO CONTENT WITH THIS WEATHER FEATURE DURING THE LATE MORNING /WEST/ AND AFTERNOON HOURS /EAST/. WELL DEFINED DRY SLOT WITHIN 50 MILES WITHER SIDE OF THE FRONT...WILL BE PUSHING OVER THE CWA LATE THIS MORNING /WEST/ AND DURING THE AFTERNOON /EAST/. TEMPS WILL CLIMB ONLY ABOUT 5-7 DEG ACROSS THE ALLEGHENIES OF NW PENN TODAY...WHILE THE CENTRAL AND SE VALLEYS SEE A TEMP INCREASE OF 13 TO 15F TODAY. HIGH TEMPS RANGING FROM THE U60S NW...TO THE MID 80S IN THE SOUTHEAST WILL BE ABOUT 10-12 DEG ABOVE NORMAL FOR TODAY. EXTENSIVE...COLD AIR STRATO CU WILL SPREAD INTO THE THIS AFTERNOON...BUT BREAK UP AND FLATTEN OUT IN THE LLVL DOWNSLOPE AND ADIABATIC WARMING/DRYING REGIME ACROSS THE CENTRAL VALLEYS AND SUSQ REGION. IN ADDITION...LATEST MODEL FORECAST SOUNDINGS INDICATE MODERATE MIXING POTENTIAL WITH MANY AREAS SEEING WIND GUSTS IN THE 30-35 MPH RANGE /OR SLIGHTLY HIGHER/. EXPECT HIGHER TERRAIN OF THE NORTH AND WEST TO SEE SCT -SHRA...WHILE CENTRAL AND SOUTHEAST AREAS REMAIN PARTLY SUNNY AND DRY. HIGHS WILL RANGE FROM JUST 60 TO 65F ACROSS THE NORTHWEST MTNS...TO THE LOWER 80S THROUGHOUT THE LOWER SUSQ RIVER VALLEY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... DEEPENING NW FLOW...WITH SHALLOW COLD AIR AT LLVLS WILL LEAD TO GENERALLY PARTLY SKIES ACROSS THE SUSQ VALLEY....WITH MOSTLY CLOUD TO CLOUDY CONDITIONS OVER THE MW MTNS. THIS CLOUD DISTRIBUTION WILL HELP TO LESSEN THE NORMAL STRONG DIFF IN MIN TEMPS ACROSS CENTRAL PENN AND THE SUSQ VALLEY. LOWS EARLY TUESDAY WILL BE IN THE UPPER 30S TO LOW 40S WEST...AND IN THE U40S TO LOWER 50S THROUGHOUT THE SUSQEHANNA VALLEY && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... LATER SHIFTS WILL NEED TO MONITOR THE THREAT FOR FROST OR FREEZE PRODUCTS WED NIGHT AS TEMPS WILL BE PLUMMETING INTO THE U20S/L30S INVOF KBFD...AND MID 30S TO AROUND 40F AS YOU HEAD SE FROM THE I99/RT200 CORRIDOR TWD INTERSTATE 81. LOWS ACROSS THE LOWER SUSQ VALLEY SHOULD BE AOA 40F EARLY THURSDAY. A FEW WEAK SYSTEMS CRESTING THE MEAN EASTERN U.S. UPPER RIDGE AND DROPPING SE FROM THE GLAKES WILL BRING THE CHC OF SOME SHOWERS FRIDAY AFTERNOON THROUGH SAT. UPPER RIDGE SHARPENS OVER THE MID ATLANTIC REGION SAT NIGHT INTO SUNDAY. WASHED OUT FRONT TO THE SOUTH OF THE STATE SAT NIGHT WILL LIKELY RETURN NORTH AS A WARM FRONT SUNDAY...BRINGING BACK THE CHC FOR SHOWERS/SCTD TSRA SUNDAY AFTERNOON INTO EARLY NEXT WEEK AHEAD OF A STRONGER SYSTEM THAT WILL BE GRADUALLY SHEARING OUT AS IT HEADS NE TWD THE GLAKES REGION. && .AVIATION /10Z TUESDAY THROUGH SATURDAY/... RADAR AT 06Z SHOWS ONE LINE OF SHRA/TSRA PUSHING THRU EASTERN PA AND ANOTHER BATCH OF SHRA ASSOC WITH APPROACHING COLD FRONT OVER WESTERN PA. FOR MUCH OF CENTRAL PA...NO SIG CIG/VIS REDUCTIONS ARE EXPECTED EARLY THIS MORNING. THE EXCEPTION COULD BE KBFD AND KJST...WHERE A BRIEF PERIOD OF IFR CIGS MAY DEVELOP AS PLUME OF MOIST AIR ALONG COLD FRONT ASCENDS THE W MTNS. MDL RH TIMESECTIONS AND HRRR OUTPUT SUGGEST THE WINDOW OF OPPORTUNITY FOR IFR CONDS AT KBFD/KJST WILL BE 09Z-11Z. AFTER 11Z...DRIER AIR WILL ARRIVE ON WEST WIND...CAUSING IMPROVING CONDS. WIDESPREAD VFR CONDS EXPECTED AFTER SUNRISE...AS DRIER AIR FLOWS IN BEHIND COLD FRONT. MAIN CONCERN TODAY WILL BE THE GUSTY WEST WINDS...RESULTING FROM TIGHT PRESSURE GRADIENT SOUTH OF LOW PRES OVR S QUEBEC. MDL SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS BY THIS AFTN. THE STRONGEST GUSTS WILL DIMINISH AFTER SUNSET...BUT IT WILL REMAIN BREEZY OVERNIGHT. OUTLOOK... WED...NO SIG WX EXPECTED. THU...EARLY AM FOG POSS NW MTNS. FRI...PM SHRA/CIG REDUCTIONS POSS...MAINLY NW MTNS. SAT...SCT PM TSRA IMPACTS POSSIBLE. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...FITZGERALD
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
950 AM MDT TUE MAY 12 2015 .UPDATE... ISSUED AT 938 AM MDT TUE MAY 12 2015 15Z SURFACE ANALYSIS HAD FRONTAL BOUNDARY FROM NORTHWEST WY INTO SOUTHWEST SD. LIFT UNDER RIGHT ENTRANCE REGION OF JET STREAK ACROSS THE NORTHERN PLAINS ASSISTING SOME WEAKER RETURNS ON RADAR ACROSS FAR NORTHEAST WY/SOUTHEAST MT/ENTERING NORTHWEST SD. MOST OF IT NOT REACHING THE GROUND...AND LOOKING AT THE 12Z KUNR SOUNDING THERE IS SOME DRY AIR TO OVERCOME. 12Z RAP SHOWS A BIT OF SBCAPE OVER THE HIGHER TERRAIN AS DECENT SOUTHERLY FLOW FEEDS MOISTURE POOLING ALONG THE BOUNDARY SO HAVE ADDED SMALL POPS LATER THIS AFTERNOON FOR THOSE AREAS. && .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT ISSUED AT 300 AM MDT TUE MAY 12 2015 WESTERN CONUS UPPER LEVEL TROUGHING ONGOING THIS MORNING WITH A LOCAL WAA RESPONSE. WEAK LEAD IMPULSE FROM THIS SYSTEM WILL SUPPORT INCREASING MID/HIGH CLOUDS THROUGH MORNING ACROSS THE NORTHERN HALF...WITH A FEW SPRINKLES POSSIBLE ACROSS THE FAR NORTH. MEANWHILE ANOTHER UPPER LEVEL IMPULSE WILL SHIFT NE INTO THE SW CONUS AND SOUTHERN PLAINS. THIS SYSTEM WILL HELP SUPPORT DEEPER MOISTURE NORTH INTO THE AREA THROUGH TONIGHT. ONGOING PRESSURE FALLS PER THE ADVANCING WESTERN CONUS UPPER TROUGH WILL SUPPORT A LLJ TONIGHT WITH SOME FORCING FOR ASCENT PER A SLOW MOVING NW CONUS UPPER TROUGH GRAZING THE NORTHERN PLAINS TONIGHT. STEEP MID LEVEL LAPSE RATE WITH AN FGEN RESPONSE AND INCREASING ELEVATED INSTABILITY NOTED IN MU CAPES WILL SUPPORT A SLIGHT CHANCE SHOWER/TS THREAT ACROSS THE NORTHERN HALF TONIGHT. HIRES MODELS INCLUDING THE NAM SUGGEST AN ISOLD HIGH BASED SHRA/TS COULD DEVELOP OVER NE WY THIS EVENING AS CIN IS MINIMIZED PER INSOLATION...WITH ANY ACTIVITY BEING CARRIED NE BY A DEVELOPING LLJ. DID ADJUST SLIGHT CHANCE POPS SW INTO NE WY AND THE BH AFTER 00Z THIS EVENING FOR THIS...WITH A SLIGHTLY EARLIER START TIME POSSIBLE. LEE SIDE TROUGH WILL SHIFT EAST ACROSS THE FA WED MORNING AND STALL WITH THE SOUTHERN PLAINS IMPULSE SHIFTING NORTH. RENEWED FGEN FROM THIS SYSTEM WILL SUPPORT INCREASING LL CONVERGENCE ALONG AND NEAR THE SFC TROUGH WHICH WILL BE SOMEWHERE ACROSS THE EASTERN FA. INCREASING LL MOISTURE COMBINED WITH DIURNAL INSTABILITY WILL ALLOW INCREASING CHANCES FOR SHRA/TS THERE...WITH OTHER ACTIVITY POSSIBLE OVER THE BH AND NE WY PER DIURNAL HEATING IN THE PRESENCE OF UNSTABLE PROFILES/WEAK CIN. SHRA/TS CHANCES SHOULD INCREASE WED NIGHT AS THE LLJ SUSTAINED WITH ONGOING MOISTURE TRANSPORT AND INCREASING LSA FROM THE EXPECTED IMPULSE. BULK OF FORCING FROM THIS SYSTEM WILL REMAIN SE OF THE FA...INCLUDING THE ASSOCIATED PRECIP CHANCES. HAVE RETAINED HIGH CHANCE POPS...PRECLUDING LIKELY ATTM GIVEN CONVECTIVE COMPONENT TO PRECIP. AS FOR TEMPS...BUMPED HIGHS UP BOTH TODAY AND WED. SNOW PACK HAS ERODED QUITE WELL OVER MUCH OF THE AREA...WITH THE DEEPEST SNOW REMAINING OVER SW SD. STRONG SE WINDS UNDER MAY SUN SHOULD MIX WARMER AIR DOWN WITH NO PROBLEM...THUS HAVE OPTED FOR TEMPS MORE IN LINE WITH GUIDANCE. .LONG TERM...THURSDAY THROUGH MONDAY ISSUED AT 300 AM MDT TUE MAY 12 2015 THE UPPER LEVEL RIDGE WILL MOVE EAST OF THE AREA ON WEDNESDAY. THIS WILL PUT THE AREA IN ACTIVE SOUTHWEST FLOW FOR MID WEEK INTO THE WEEKEND...WITH DAILY CHANCES FOR RAIN SHOWERS AND SOME THUNDERSTORMS. A FAST-MOVING SHORTWAVE WILL SWEEP THROUGH THE CENTRAL CONUS WEDNESDAY NIGHT AND THURSDAY...AND THEN ANOTHER UPPER LOW IS PROGGED TO MOVE ACROSS THE ROCKIES AND INTO THE PLAINS THIS WEEKEND...BRINGING THE BEST CHANCES FOR ADDITIONAL RAINFALL. MODELS ARE INDICATING AROUND A HALF INCH OF QPF BY THE END OF THE WEEK...WITH AN ADDITIONAL INCH OR TWO DURING THE WEEKEND. AS FAR AS TEMPERATURES GO...MORE SPRING LIKE READINGS ARE EXPECTED FROM MID WEEK THROUGH THE WEEKEND. THEREFORE...THE PRECIPITATION SHOULD REMAIN RAIN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING) ISSUED AT 300 AM MDT TUE MAY 12 2015 GUSTY SOUTHERLY WINDS ARE EXPECTED OVER NORTHEASTERN WYOMING DURING THE REST OF THE NIGHT. THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ON TUESDAY EVENING. LCL MVFR CIGS ARE POSSIBLE WITH ANY SHOWERS OR THUNDERSTORMS...OTHERWISE VFR CIGS WILL PREVAIL. && .HYDROLOGY... ISSUED AT 300 AM MDT TUE MAY 12 2015 RUNOFF FROM RAIN AND MELTING SNOW IS CAUSING RAPID RISES IN THE LEVEL OF THE WHITE RIVER BETWEEN INTERIOR AND OACOMA. A FLOOD WARNING HAS BEEN ISSUED FOR THAT AREA AS MINOR TO MODERATE FLOODING IS FORECAST TO DEVELOP STARTING TUESDAY MORNING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ UPDATE...HELGESON SHORT TERM...JC LONG TERM...7 AVIATION...7 HYDROLOGY...JC
AREA FORECAST DISCUSSION
NWS TUCSON AZ
330 PM MST TUE MAY 12 2015 .SYNOPSIS...THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY EAST OF TUCSON TONIGHT. DRY CONDITIONS WILL THEN PREVAIL WEDNESDAY INTO THURSDAY. A STRONG LOW PRESSURE SYSTEM WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY INTO SATURDAY. COOLER TEMPERATURES AND GUSTY WINDS WILL ACCOMPANY THIS SYSTEM. EXPECT DRY CONDITIONS AND MUCH WARMER TEMPERATURES EARLY NEXT WEEK. && .DISCUSSION...IR/VISIBLE SATELLITE IMAGERY DEPICTED FAIRLY THICK MID AND HIGH-LEVEL CLOUDS ACROSS MUCH OF SE ARIZONA THIS AFTERNOON. MORE EXTENSIVE BREAKS IN THE OVERCAST WERE NOTED ACROSS WRN PIMA COUNTY. THE BACK EDGE OF THIS CLOUD MASS REPRESENTING A SHORTWAVE TROUGH AXIS EXTENDED FROM SRN CALIFORNIA SOUTHWARD TO NEAR THE BAJA CALIFORNIA SPUR. MEANWHILE...A VERY DRY SURFACE ENVIRONMENT WAS ONGOING WITH DEWPOINTS AT LOWER ELEVATIONS VALID 22Z RANGING FROM THE MID TEENS TO MID 20S. HAVE FAVORED SEVERAL RUC HRRR SOLUTIONS FOR PRECIP POTENTIAL THRU TONIGHT. THUS...THERE IS A SLIGHT CHANCE OF SHOWERS/TSTMS THIS EVENING FROM TUCSON EWD/SWD TO THE NEW MEXICO/INTERNATIONAL BORDERS. A SLIGHT CHANCE OF SHOWERS CONTINUES MAINLY NEAR THE NEW MEXICO BORDER LATE TONIGHT. GIVEN THE VERY DRY NEAR-SURFACE ENVIRONMENT...ANY MEASURABLE PRECIP AMOUNTS WILL BE QUITE LIGHT. CLEARING SKIES WILL OCCUR FROM WEST-TO-EAST LATE TONIGHT AS THE MID-LEVEL TROUGH AXIS MOVES INTO SWRN NEW MEXICO. FLOW ALOFT WILL BECOME INCREASINGLY SWLY WED-THUR IN RESPONSE TO DEEPENING LOW PRESSURE ALOFT OVER THE ERN PACIFIC. THE TIGHTENING MID-LEVEL GRADIENT WILL PRODUCE BREEZY TO WINDY CONDITIONS... ESPECIALLY DURING THE AFTERNOON HOURS. EXPECT THE STRONGEST WIND SPEEDS TO OCCUR THUR. 12/12Z GFS/ECMWF/CMC WERE IN GOOD AGREEMENT WITH DEPICTING A 550 DM LOW TO BE CENTERED NEAR THE CENTRAL CALIFORNIA COAST FRI MORNING. THIS UPPER LOW IS THEN PROGGED TO BE CENTERED OVER WYOMING SAT MORNING...WITH A MID-LEVEL TROUGH AXIS TO EXTEND SWWD INTO SRN ARIZONA. BASED ON THESE SOLUTIONS...APPEARS THE BEST CHANCE OF MEASURABLE PRECIP FOR THE TUCSON METRO AREA WOULD OCCUR FRI NIGHT. THE GRIDDED DATA POP FIELDS WERE ADJUSTED TO REFLECT THIS SCENARIO. AT ANY RATE...THERE IS A SLIGHT CHANCE OF SHOWERS MAINLY NORTH OF TUCSON FRI MORNING. PRECIP CHANCES INCREASE FRI AFTERNOON...AND A CHANCE OF SHOWERS/TSTMS EXISTS ACROSS MUCH OF THE AREA FRI NIGHT. A CHANCE OF SHOWERS CONTINUES SAT MAINLY ACROSS THE WHITE MOUNTAINS. DRY CONDITIONS SHOULD OCCUR BY SAT AFTERNOON FROM TUCSON WWD ACROSS THE WRN DESERTS. DRY CONDITIONS WILL PREVAIL AREA-WIDE LATE SAT NIGHT AND CONTINUE THRU TUE UNDER GENERALLY SWLY FLOW ALOFT. WARMER TEMPS WILL OCCUR WED FOLLOWED BY A FEW DEGS OF COOLING THUR...THEN MORE SIGNIFICANT COOLING IS ON TAP FRI. MARKEDLY WARMER TEMPS WILL PREVAIL SUN-TUE. && .AVIATION...VALID THRU 14/00Z. EXPECT ISOLATED -SHRA/-TSRA FROM KTUS VICINITY EASTWARD TO THE NEW MEXICO BORDER THIS EVENING. ISOLATED -SHRA WILL THEN PREVAIL MAINLY NEAR THE NEW MEXICO BORDER LATE TONIGHT...THEN DRY CONDITIONS WILL OCCUR AREA-WIDE WEDNESDAY. OTHERWISE...CLOUD DECKS THRU ABOUT 06Z- 09Z WEDNESDAY WILL GENERALLY BE AT 6-12K FT AGL FOLLOWED BY DECREASING CLOUDS EARLY WEDNESDAY MORNING. CLEAR SKIES TO SCATTERED CLOUDS ABOVE 10K FT AGL WILL PREVAIL WEDNESDAY AFTERNOON. SURFACE WIND EARLY THIS EVENING AND WEDNESDAY AFTERNOON WILL BE SLY/SWLY AT 12-20 KTS WITH GUSTS OF 20-30 KTS. SURFACE WIND WILL GENERALLY BE LESS THAN 10 KTS AT OTHER TIMES. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY EAST OF TUCSON TONIGHT. DRY CONDITIONS WILL THEN PREVAIL WEDNESDAY INTO THURSDAY. THE COMBINATION OF STRONG AND GUSTY WINDS AND LOW RELATIVE HUMIDITIES MAY CREATE CRITICAL FIRE WEATHER CONDITIONS AT LOWER ELEVATIONS THURSDAY AFTERNOON AND EARLY THURSDAY EVENING. HOWEVER...WIND SPEEDS AND RELATIVE HUMIDITIES NEEDED TO ACHIEVE RED FLAG CRITERIA WILL BE MARGINAL AND SHORT- LIVED. A STRONG STORM SYSTEM MOVING NORTH OF THE AREA WILL THEN BRING A CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY INTO SATURDAY. COOLER TEMPERATURES AND GUSTY WINDS WILL OCCUR WITH THIS SYSTEM. EXPECT DRY CONDITIONS WITH MUCH WARMER TEMPERATURES EARLY NEXT WEEK. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON FRANCIS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 AM MST TUE MAY 12 2015 .SYNOPSIS...THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EAST OF TUCSON THROUGH WEDNESDAY MORNING. OTHERWISE...DRY CONDITIONS WILL PREVAIL INTO THURSDAY. A STRONG LOW PRESSURE SYSTEM FROM THE EASTERN PACIFIC WILL THEN BRING A CHANCE OF SHOWERS AND THUNDERSTORMS THURSDAY NIGHT INTO SATURDAY. COOLER TEMPERATURES AND GUSTY WINDS WILL ALSO OCCUR. && .DISCUSSION...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE PARTLY CLOUDY SKIES ACROSS THE WHITE MOUNTAINS...AND MOSTLY CLOUDY TO CLOUDY SKIES ELSEWHERE. THE THICKER CLOUDINESS AS PER ENHANCED COLDER CLOUD TOPS EXTENDED FROM TUCSON SOUTHWARD TO THE INTERNATIONAL BORDER. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z RANGED FROM THE MID 20S-MID 40S. THESE TEMPS WERE NEARLY 2-5 DEGS F HIGHER VERSUS 24 HOURS AGO EXCEPT IN THE VICINITY OF SAFFORD...WHERE THE DEWPOINT WAS 15 DEGS HIGHER VERSUS THIS TIME MON. SURFACE TEMPS VALID 16Z WERE GENERALLY 2-9 DEGS F COOLER VERSUS 24 HOURS AGO. 12/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS 0.40 INCH. THE PROFILE EXHIBITED A VERY DRY SURFACE-500 MB LAYER AND SOME SATURATION OF THE COLUMN ABOVE 500 MB. 12/12Z UPPER AIR PLOTS DEPICTED RIDGE AXIS FROM TEXAS NWWD INTO MONTANA...AND A 548 DM LOW WAS CENTERED OVER SWRN OREGON. MODERATE TO STRONG GENERALLY SWLY FLOW PREVAILED OVER SE ARIZONA. BASED ON SATELLITE IMAGERY AND THE 12/12Z NAM...GRIDDED DATA SKY VALUES WERE INCREASED TO REPRESENT INCREASED CLOUDINESS VERSUS THE PREVIOUS FORECAST. THE 12/12Z NAM LIMITED MEASURABLE PRECIP TO THE WHITE MOUNTAINS TONIGHT. HOWEVER...THE 12/14Z RUC HRRR WAS FURTHER WEST WITH THE POTENTIAL FOR MEASURABLE PRECIP VERSUS THE NAM...AND YIELDED SCATTERED COVERAGE ACROSS GREENLEE/GRAHAM/COCHISE COUNTIES THIS EVENING. THE INHERITED OFFICIAL FORECAST APPEARS TO BE A GOOD COMPROMISE BETWEEN THESE SOLUTIONS. THUS...THERE IS A SLIGHT CHANCE OF SHOWERS/TSTMS THIS AFTERNOON ACROSS THE WHITE MOUNTAINS WITH DRY CONDITIONS ELSEWHERE. A SLIGHT CHANCE OF SHOWERS/TSTMS EXISTS TONIGHT ACROSS ERN SECTIONS WITH DRY CONDITIONS CONTINUING ELSEWHERE. A FEW LINGERING SHOWERS MAY OCCUR WED MORNING NEAR THE NEW MEXICO BORDER...THEN DRY CONDITIONS WILL PREVAIL AREA WIDE INTO THUR AFTERNOON. HIGH TEMPS THIS AFTERNOON WILL GENERALLY BE A FEW DEGS COOLER VERSUS MON. && .AVIATION...VALID THRU 13/18Z. EXPECT ISOLATED -SHRA/-TSRA EAST OF KTUS TO THE NEW MEXICO BORDER INTO WEDNESDAY MORNING. OTHERWISE...INCREASING MAINLY MID AND HIGH- LEVEL MOISTURE THIS MORNING WILL PRODUCE BROKEN TO OVERCAST CLOUD DECKS MAINLY AT 10-15K FT AGL THIS AFTERNOON INTO WEDNESDAY MORNING. SURFACE WIND THIS AFTERNOON AND EARLY THIS EVENING WILL BE SLY/SWLY AT 12-20 KTS WITH GUSTS OF 20-30 KTS. SURFACE WIND WILL THEN DIMINISH TO GENERALLY LESS THAN 10 KTS 02Z-04Z WEDNESDAY AND CONTINUE INTO WEDNESDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EAST OF TUCSON INTO EARLY WEDNESDAY. OTHERWISE...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY. EXPECT OCCASIONALLY GUSTY WINDS DURING THE AFTERNOON HOURS INTO WEDNESDAY. A STRONG PACIFIC LOW PRESSURE SYSTEM WILL APPROACH CALIFORNIA THURSDAY. THIS SYSTEM WILL PRODUCE STRONG SOUTHWEST WINDS WITH THE POTENTIAL FOR BORDERLINE RED FLAG CONDITIONS IN ONLY A FEW PLACES. AS THE STORM MOVES CLOSER ON FRIDAY...WINDS WILL INCREASE FURTHER. HOWEVER... HUMIDITY LEVELS WILL BE HIGHER WITH LOWER TEMPERATURES AND A CHANCE FOR SHOWERS AND/OR THUNDERSTORMS. THE SOUTHERN PORTION OF THIS SYSTEM WILL MOVE ACROSS ARIZONA SATURDAY MAINTAINING A THREAT OF SHOWERS AND THUNDERSTORMS. DAYTIME TEMPERATURES WILL BE 10-15 DEGREES COOLER THAN NORMAL SATURDAY...THEN DRIER AND SOMEWHAT WARMER CONDITIONS WILL OCCUR SUNDAY AND MONDAY. && .PREV DISCUSSION...EXPECT A BRIEF RESPITE FROM THE SHOWERS FROM LATE WEDNESDAY THROUGH LATE THURSDAY BEFORE A MUCH STRONGER PACIFIC SYSTEM WILL BEGIN TO AFFECT THE REGION LATE THURSDAY EVENING AND ESPECIALLY OVERNIGHT INTO THE EARLY MORNING HOURS ON FRIDAY AS AN UPPER LOW WILL BE CENTERED OVER THE GREAT BASIN AT THAT TIME. ISOLATED TO SCATTERED SHOWERS WILL AFFECT MOSTLY THE HIGHER TERRAIN THURSDAY NIGHT INTO EARLY FRIDAY. BY FRIDAY AFTERNOON EXPECT ISOLATED SHOWERS AND THUNDERSTORMS AREA-WIDE WITH SCATTERED ACTIVITY OVER PARTS OF GRAHAM AND GREENLEE COUNTIES. THIS WILL CONTINUE INTO FRIDAY NIGHT AND EARLY SATURDAY. MODELS STILL AT ODDS WITH EACH OTHER ON BOTH TIMING AND POP VALUES. LATEST MOS GUIDANCE HAS FLIP- FLOPPED FROM THIS TIME YESTERDAY...WITH THE GFS POPS VALUES RANGING FROM SINGLE DIGITS TO SLIGHT CHANCES ON FRIDAY...THEN IN THE SOLID CHANCE CATEGORY FOR SATURDAY. MEANWHILE...THE ECMWF MOS NUMBERS FOR POP REFLECT SLIGHT CHANCE TO LOW END CHANCE FOR FRIDAY AND SIMILAR FOR SATURDAY. GIVEN THIS CONTINUED UNCERTAINTY...OPTED TO ONLY MAKE MINOR ADJUSTMENTS TO THE FORECAST AND TO BLEND WITH SURROUNDING OFFICES. BY SATURDAY THE UPPER LOW WILL HAVE LIFTED TO THE NORTHEAST INTO THE NORTHERN ROCKIES...MORE SPECIFICALLY OVER SOUTHEASTERN IDAHO AND CENTRAL WYOMING. THE TAIL END OF THIS SYSTEM WILL EXTEND ACROSS NEW MEXICO AND INTO SOUTHEAST ARIZONA AND NORTHERN SONORA. BY THAT TIME THE BULK OF THE MOISTURE WITH THIS SYSTEM WILL BE TO OUR NORTH...SO ONLY EXPECTING A SLIGHT CHANCE OF MOUNTAIN SHOWERS AND/OR THUNDERSTORMS WITH A SLIGHTLY BETTER THREAT FOR PARTS OF GRAHAM AND GREENLEE COUNTIES. BY EARLY SUNDAY THE LOW WILL BE OVER THE NORTHERN ROCKIES/PLAINS STATES WITH WEAK RIDGING BUILDING IN BEHIND THE SYSTEM AND A RETURN TO DRY WEATHER THROUGH THE REMAINDER OF THE FORECAST PERIOD...ALONG WITH WARMING TEMPERATURES INTO EARLY NEXT WEEK. FOR TUCSON...HIGH TEMPERATURES WILL GENERALLY RANGE FROM 2 TO 4 DEGS BELOW NORMAL TODAY THROUGH THURSDAY...THEN 12 TO 16 DEGS BELOW NORMAL FOR FRIDAY AND SATURDAY. THEREAFTER...AROUND 8 TO 10 DEGS BELOW NORMAL FOR SUNDAY AND 3 TO 5 DEGS BELOW NORMAL FOR MONDAY. LOW TEMPS WILL BE NEAR NORMAL WEDNESDAY THROUGH FRIDAY MORNINGS...THEN 6 TO 8 DEGS BELOW NORMAL FOR THE WEEKEND AND 2 TO 4 DEGS BELOW NORMAL FOR EARLY NEXT WEEK. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON DISCUSSION...FRANCIS PREVIOUS DISCUSSION...MOLLERE AVIATION/FIRE WEATHER...HUMPHREYS
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
256 PM MDT TUE MAY 12 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 256 PM MDT TUE MAY 12 2015 AIRMASS IS BECOMING UNSTABLE ALONG THE FRONT RANGE AND NEAR BY EASTERN PLAINS WHERE CAPES ARE UP TO 1000 J/KG. SHOWERS AND STORMS HAVE BEEN SLOW TO FORM OVER THE HIGHER TERRAIN WHERE DEW POINTS ARE IN THE 20S. THE HRRR AND RAP CONTINUE TO SHOW ISOLATED TO SCATTERED CONVECTION LATER THIS AFTERNOON. AS THESE STORMS MOVE OFF THE HIGHER TERRAIN...THEY WILL ENCOUNTER GREATER MOISTURE AND INSTABILITY. EXPECT THE STORMS TO BE CAPABLE OF PRODUCE BRIEF HEAVY...GUSTY OUTFLOW WINDS TO 40 MPH AND SMALL HAIL. WILL KEEP THE ISOLATED TO SCATTERED POPS IN THE FORECAST FOR THE EVENING HOURS. A SHORT WAVE TROUGH CURRENTLY OVER BAJA CALIFORNIA WILL LIFT NORTHEAST ACROSS THE REGION ON WEDNESDAY. EXPECT MOSTLY CLOUDY SKIES AHEAD OF THIS FOR WEDNESDAY. BEST LIFT AND MOISTURE WILL REMAIN TO THE SOUTH AND EAST OF THE AREA. HOWEVER SHOULD BE ENOUGH MOISTURE AND LIFT WITH FOR SCATTERED SHOWERS AND THUNDERSTORMS. CAPES WILL BE LESS THAN 500 J/KG...SO EXPECT STORMS TO STAY BELOW SEVERE THRESHOLDS. LOWERED HIGH TEMPERATURES A FEW DEGREES DUE TO THE CLOUDINESS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 256 PM MDT TUE MAY 12 2015 WEAK QG ASCENT SHOULD STILL BE IMPACTING MUCH OF THE CWA AT 00Z THURSDAY AND WILL GRADUALLY TRANSITION TO SUBSIDENCE OVERNIGHT AS UPPER LEVEL RIDGING MOVES IN. THIS WILL ALLOW THURSDAY TO HAVE LOWER POPS ALTHOUGH PROBABLY NOT COMPLETELY ZERO...ESPECIALLY IN THE MOUNTAINS. THE NEXT WAVE AND QG ASCENT BEGINS IN THE MORE SOUTHERLY FLOW ON FRIDAY WHICH SHOULD ALLOW FOR A BIT MORE SHOWER COVERAGE IN THE MOUNTAINS DURING THE NORMAL DIURNAL TIMES BUT STILL NOTHING TREMENDOUS. SHOWER ACTIVITY ON THE PLAINS WILL BE BATTLING A LACK OF UPSLOPE SO PRECIPITATION THERE WILL BE SPOTTY AT BEST. THE SYSTEM FOR SATURDAY IS LOOKING A BIT LESS PROMISING THAN EARLIER. SOME SPREAD IN THE SOLUTIONS OF THE UPPER LOW POSITION BUT THE MODELS ARE SHOWING SOME QG ASCENT OVER THE CWA ALONG WITH LIGHT QPF. AGAIN...NOTHING TERRIBLY NOTEWORTHY. STRONG QG SUBSIDENCE IS FORECAST ON SUNDAY ALONG WITH A PUSH OF LOW LEVEL HIGH PRESSURE FROM THE NORTH WHICH MAY PUT A SIGNIFICANT DAMPER ON THE PRECIPITATION THREAT SUNDAY. THE UPPER RIDGE MOVES EAST OF COLORADO ON MONDAY FOR A SLIGHT INCREASE IN CONVECTIVE ACTIVITY BY TUESDAY. ALL IN ALL AT THIS TIME IT APPEARS THAT THERE IS A RATHER LOW RISK OF HEAVY PRECIPITATION THAT COULD WORSEN THE FLOODING SITUATION. MOREOVER...TEMPERATURES WILL REMAIN ON THE COOL SIDE WHICH WILL LESSEN THE MELTING OF THE SNOWPACK. && .AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON) ISSUED AT 256 PM MDT TUE MAY 12 2015 VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH WEDNESDAY. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED 22-03Z TODAY. ANOTHER ROUND OF AFTERNOON THUNDERSTORMS ARE EXPECTED FOR WEDNESDAY...LIKELY A LITTLE EARLIER. THE STORMS WILL BE CAPABLE OF PRODUCING WIND GUSTS TO 35 KNOTS...BRIEF HEAVY RAIN AND SMALL HAIL. OUTSIDE OF OUTFLOW WINDS FROM THUNDERSTORMS...WINDS WILL BE SOUTHERLY AT KAPA AND KDEN. THROUGH WEDNESDAY. A WEAK DENVER CYCLONE MAY CAUSE WINDS TO TURN NORTHWESTERLY AFTER 12Z WEDNESDAY AT KDEN. && .HYDROLOGY... ISSUED AT 256 PM MDT TUE MAY 12 2015 THE SOUTH PLATTE RIVER IS CRESTING OVER WESTERN MORGAN COUNTY. THE CREST IS EXPECTED TO MOVE DOWN STREAM THROUGH MORGAN COUNTY THE NEXT 24 HOURS. FORECAST CRESTS HAVE BEEN SLIGHTLY LOWERED THIS MORNING ALONG THE SOUTH PLATTE RIVER. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED THIS EVENING AND WEDNESDAY AFTERNOON AND EVENING. BRIEF HEAVY RAIN IS POSSIBLE WITH THE THUNDERSTORMS. BEST CHANCE FOR HEAVY RAIN WILL BE WEDNESDAY AFTERNOON WHERE UP TO AN INCH WILL BE POSSIBLE UNDER THE STRONGEST STORMS. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...MEIER LONG TERM...ET AVIATION...MEIER HYDROLOGY...MEIER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1040 AM MDT TUE MAY 12 2015 .UPDATE... ISSUED AT 1040 AM MDT TUE MAY 12 2015 THE LATEST HRRR ...ARW...NMM AND NAM SHOW THE BEST CHANCE FOR SHOWERS AND STORMS ALONG THE FRONT RANGE FROM DENVER TO GREELEY TO FORT MORGAN. WILL INCREASE POPS INTO THE SCATTERED RANGE FOR THIS. WITH THE DRY LOW LEVELS...THE CONVECTION WILL PRODUCE GUSTY OUTFLOW WINDS. ANY HEAVY RAIN WILL BE LOCALIZED AND LIKELY LESS THAN A HALF INCH. NO OTHER CHANGES TO THE FORECAST ARE PLANNED. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 419 AM MDT TUE MAY 12 2015 UPPER RIDGE IS SHIFTING EAST OF COLORADO WITH SURFACE HIGH PRESSURE ON THE PLAINS. HIGH LEVEL MOISTURE MOVING ACROSS IN SOUTHWEST FLOW ALOFT...WHILE LOW LEVELS REMAIN DRY. LOOKING LIKE THERE WILL BE SOME DECREASE IN THE HIGH LEVEL MOISTURE LATER TODAY...BUT CONVECTION WILL LIKELY OFFSET THAT. STICKING WITH THE FORECAST OF SCATTERED CONVECTION OVER THE MOUNTAINS...WITH ISOLATED STORMS WORKING ONTO THE PLAINS LATE IN THE DAY. WITH CAPES EXPECTED TO BE 500-1000 J/KG OVER THE MOUNTAINS AND DRY LOW LEVELS...SOME OF THE STORMS WILL LIKELY PRODUCE GUSTY WINDS BUT WITH LIMITED FLOW ALOFT NOT TOO MUCH OF A SEVERE THREAT. THE PLAINS WILL BE WEAKLY CAPPED MOST OF THE DAY...MOST LIKELY CONVECTION WILL BE ON OUTFLOWS FROM THE MOUNTAIN CONVECTION. ANY SIGNIFICANT RAIN SHOULD BE ON A SMALL SCALE SO NOT MUCH IMPACT TO CURRENT RIVER CONDITIONS. I ONLY MADE MINOR ADJUSTMENTS TO THE FORECAST...INCREASING CLOUDS THIS MORNING AND ADDING A BIT MORE WIND ON THE PLAINS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 419 AM MDT TUE MAY 12 2015 STARTING WEDNESDAY MORNING A SHORTWAVE TROUGH WILL MOVE NORTH OUT OF THE DESERT SOUTHWEST ACROSS EASTERN COLORADO. MOISTURE AND PRECIPITATION WILL MOVE INTO THE MOUNTAINS FIRST WITH A LEE SIDE TROUGH DOMINATING THE NE COLORADO PLAINS. THROUGH THE DAY WEDNESDAY WITH THE INCREASE OF INSTABILITY FROM HEATING AND MOISTURE AFTERNOON SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE. PERIODS OF HEAVIER RAIN WILL BE POSSIBLE UNDER THE STRONGER STORMS...ESPECIALLY OVER THE EASTERN PLAINS. SNOW IN THE MOUNTAINS ABOVE 10000FT WILL BE POSSIBLE WITH LIGHT ACCUMULATIONS ON WEDNESDAY. TEMPERATURES ON WEDNESDAY WILL BE SLIGHTLY COOLER WITH HIGHS IN THE UPPER 60S. THE TROUGH WILL CONTINUE TO MOVE NORTH ON THURSDAY WITH SURFACE HIGH PRESSURE PUSHING INTO WESTERN COLORADO AND A LEE TROUGH FORMING OVER EASTERN COLORADO. UPPER LEVEL RIDGING THURSDAY WILL HELP DRY OUT CONDITIONS BRINGING ANOTHER SHORT REPRIEVE FROM RAIN. TEMPERATURES THURSDAY WILL BOUNCE BACK TO SEASONAL NORMALS WITH HIGHS REACHING INTO THE MID 70S. MODELS ARE CURRENTLY IN DECENT AGREEMENT REGARDING THE NEXT SYSTEM FORMING OFF THE COAST OF CALIFORNIA BY THURSDAY EVENING. UPPER LEVEL FLOW WILL BE STRONG FROM THE SOUTHWEST. SEVERAL EMBEDDED DISTURBANCES WILL KEEP A STEADY STREAM OF MOISTURE MOVING INTO COLORADO THAT WILL HELP BRING A SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS TO THE NE REGION. FOR FRIDAY...TEMPERATURES REACH INTO THE UPPER 70S WITH INCREASED CAPE VALUES ALONG THE KS BORDER ALONG WITH A SHARP DRY LINE THAT COULD AID IN STRONG THUNDERSTORM DEVELOPMENT FOR FRIDAY AFTERNOON AND EVENING. ON SATURDAY AND SUNDAY THE UPPER LEVEL LOW WILL CONTINUE TO MAKE ITS EASTWARD PROGRESSION WITH STEADY MOISTURE OVER THE MOUNTAINS AND PLAINS THROUGH THE WEEKEND. TEMPERATURES WILL DIP BACK TO JUST BELOW NORMALS WITH HIGHS ONLY GETTING INTO THE MID TO UPPER 60S. THE SYSTEM LIFTS OUT TO THE NORTHEAST BY MONDAY EVENING BRINGING UPPER LEVEL RIDGING AND WARMER TEMPERATURES FOR TUESDAY. && .AVIATION...(FOR THE TAFS THROUGH 18Z WEDNESDAY MORNING) ISSUED AT 1040 AM MDT TUE MAY 12 2015 VFR THROUGH WEDNESDAY. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED BETWEEN 21Z AND 03Z WITH THE MAIN THREAT BEING GUSTY WINDS TO AROUND 30 KNOTS. WINDS AT KAPA WILL MAINLY BE FROM THE SOUTH...WHILE KDEN WILL BE EAST TO SOUTHEAST. A WEAK DENVER CYCLONE PRODUCED A LIGHT THIS MORNING AND MAY AGAIN LATE TONIGHT AND WEDNESDAY MORNING. && .HYDROLOGY... ISSUED AT 419 AM MDT TUE MAY 12 2015 MAIN CREST ON THE SOUTH PLATTE IS MOVING INTO MORGAN COUNTY...WITH A SERIES OF SMALLER RISES PRECEDING IT. LITTLE CHANGE TO THE RIVER FORECAST AS MODERATE TO MAJOR FLOODING IS EXPECTED DOWNSTREAM TO STERLING THROUGH FRIDAY...AND MINOR TO MODERATE FLOODING BETWEEN STERLING AND JULESBURG THIS WEEKEND. WE WILL NEED TO WATCH ANY ADDITIONAL RAINFALL...THE FIRST OPPORTUNITY IS WEDNESDAY AFTERNOON AND EVENING WHICH LOOKS LIGHT OVERALL BUT THERE COULD BE SOME LOCALIZED HEAVIER RAIN OF UP TO AN INCH. THAT WOULD EXACERBATE LOCAL PROBLEMS... BUT PROBABLY NOT MUCH INFLUENCE ON THE PLATTE FLOODING. THERE MAY BE BETTER COVERAGE OF THUNDERSTORMS WITH ADDITIONAL RAINFALL OVER THE WEEKEND...NOT MUCH INDICATION OF ANY HEAVY RAINFALL HOWEVER. CLOSER TO THE FRONT RANGE STREAMS WILL REMAIN HIGH INDEFINITELY WITH SATURATED SOILS AND INCREASING SNOWMELT WITH THE WARMER TEMPERATURES. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MEIER SHORT TERM...GIMMESTAD LONG TERM...BOWEN AVIATION...MEIER HYDROLOGY...GIMMESTAD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1222 PM CDT TUE MAY 12 2015 .UPDATE... ISSUED AT 943 AM CDT TUE MAY 12 2015 MAIN STRATOCUMULUS SHIELD BASICALLY MADE IT DOWN TO THE I-74 CORRIDOR WITH SOME SCATTERED CLOUDS AS FAR SOUTH AS MATTOON AND LAWRENCEVILLE...BUT THESE SHOULD CONTINUE TO PULL BACK NORTHWARD THROUGH MIDDAY. HOWEVER...LATEST RAP GUIDANCE SUGGESTS THE CLOUDS HOLDING ON A BIT LONGER AROUND CHAMPAIGN AND DANVILLE. CURRENTLY SEEING SOME WIND GUSTS OF 25-30 MPH...WHICH SHOULD CONTINUE INTO MID AFTERNOON. TEMPERATURES CURRENTLY ON TRACK AND ONLY REQUIRED SOME MINOR TWEAKS. UPDATES TO THE ZONES/GRIDS WERE MAINLY DONE FOR THE SKY COVER AND WIND TRENDS. && .SHORT TERM...(TODAY) ISSUED AT 329 AM CDT TUE MAY 12 2015 07Z/2AM SURFACE ANALYSIS SHOWS 1001MB LOW OVER THE NORTHERN GREAT LAKES WHILE A 1025MB HIGH BUILDS INTO THE CENTRAL PLAINS. PRESSURE GRADIENT BETWEEN THESE TWO FEATURES WILL REMAIN TIGHT ENOUGH TO PRODUCE BRISK WESTERLY WINDS ACROSS CENTRAL ILLINOIS TODAY. SUSTAINED WINDS WILL GENERALLY BE IN THE 10 TO 15 MPH RANGE...BUT GUSTS COULD REACH 25 TO 30 MPH AS MIXING TAKES PLACE LATER THIS MORNING. LATEST VWP NETWORK SHOWS 925MB WINDS OF 40 TO 45 MPH AND THINK SOME OF THIS HIGHER MOMENTUM AIR WILL GET MIXED DOWN TO THE SURFACE ONCE MORNING INVERSION IS BROKEN. PRESSURE GRADIENT WILL TEND TO RELAX AS THE DAY PROGRESSES...SO GUSTS WILL BEGIN TO SLOWLY SUBSIDE BY MID-AFTERNOON. LOW CLOUDS CURRENTLY ALONG/NORTH OF A RUSHVILLE TO BLOOMINGTON LINE WILL LIFT NORTHEASTWARD AND CLEAR OUT OF THE AREA BY MID-MORNING...FOLLOWED BY MOSTLY SUNNY SKIES ACROSS THE BOARD FOR THE REMAINDER OF THE DAY. AFTERNOON HIGH TEMPERATURES WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS...WITH READINGS ONLY RISING INTO THE LOWER TO MIDDLE 60S. .LONG TERM...(TONIGHT THROUGH MONDAY) ISSUED AT 329 AM CDT TUE MAY 12 2015 HIGH PRESSURE WILL BUILD EASTWARD INTO THE MIDWEST TONIGHT...WITH THE RIDGE AXIS EXPECTED TO BE POSITIONED RIGHT OVER ILLINOIS BY 12Z WED. CLEAR SKIES AND LIGHT WINDS BENEATH THE RIDGE WILL ALLOW EXCELLENT RADIATIONAL COOLING OF THE DRY AIRMASS TO TAKE PLACE...RESULTING IN OVERNIGHT LOW TEMPERATURES IN THE LOWER TO MIDDLE 40S. MAY EVEN SEE A FEW UPPER 30S IN FAVORED LOW-LYING RURAL AREAS. THE HIGH WILL BEGIN TO SHIFT OFF TO THE EAST ON WEDNESDAY...HOWEVER LOW-LEVEL FLOW WILL MAINTAIN A DISTINCT EASTERLY COMPONENT. AS A RESULT...HIGH TEMPERATURES WILL REMAIN ON THE COOL SIDE IN THE UPPER 60S TO AROUND 70 DEGREES. UPPER HEIGHTS BEGIN TO RISE SIGNIFICANTLY BY THURSDAY AS DEEP UPPER LOW OVER THE GULF OF ALASKA DROPS SOUTHEASTWARD AND REACHES THE CALIFORNIA COAST...RESULTING IN DOWNSTREAM RIDGING ACROSS THE CENTRAL AND EASTERN CONUS. A WEAK DISTURBANCE NOTED ON LATEST WATER VAPOR IMAGERY OFF THE COAST OF SOUTHERN CALIFORNIA WILL GET EJECTED NORTHEASTWARD BY THE DIGGING WEST COAST TROUGH...WITH THIS FEATURE TRACKING INTO THE GREAT LAKES BY FRIDAY. MODELS ARE IN GOOD AGREEMENT WITH THE TRACK AND TIMING OF THIS WAVE...WITH SOME MINOR DISCREPANCIES ON HOW QUICKLY TO SPREAD PRECIP INTO ILLINOIS. GIVEN INITIALLY VERY DRY AIRMASS IN PLACE BENEATH THE SURFACE HIGH...PREFER A SLOWER ARRIVAL OF PRECIP. AS A RESULT...HAVE GONE WITH A DRY FORECAST THROUGH THURSDAY MORNING EAST OF I-55 WITH LOW CHANCE POPS DELAYED UNTIL AFTERNOON. FURTHER WEST...RAIN CHANCES WILL INCREASE TO LIKELY ACROSS THE ILLINOIS RIVER VALLEY BY AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS MUCH OF THE AREA THURSDAY NIGHT...WITH THE BEST RAIN CHANCES FOCUSED NORTH OF THE I-70 CORRIDOR. ONCE THE SHORT-WAVE SHIFTS INTO THE GREAT LAKES...FORCING FOR ADDITIONAL PRECIP BECOMES MUCH WEAKER FRIDAY AND SATURDAY. SEVERAL MODELS ARE HINTING THAT ANOTHER WEAK WAVE EMBEDDED WITHIN THE SOUTHWESTERLY FLOW MAY ENHANCE SHOWERS ACROSS SOUTHERN ILLINOIS INTO THE OHIO RIVER VALLEY...HOWEVER VERY LITTLE FOCUS FOR ORGANIZED CONVECTION EXISTS FURTHER NORTH ACROSS THE REMAINDER OF THE AREA. AS A RESULT...WILL ONLY CARRY LOW CHANCE POPS THROUGH THE PERIOD. DEEP UPPER LOW OVER CALIFORNIA WILL GRADUALLY EJECT NORTHEASTWARD LATE IN THE WEEKEND. MODELS ARE IN GOOD AGREEMENT WITH THIS PROCESS THROUGH 144 HOURS...THEN SOLUTIONS BEGIN TO DIVERGE AFTER THAT. BOTH THE GFS AND ECMWF SHOW THE LOW TRACKING INTO THE DAKOTAS BY SUNDAY EVENING...WITH CONVECTION DEVELOPING ALONG A TRAILING COLD FRONT ACROSS THE PLAINS. THE ECMWF THEN BECOMES MORE PROGRESSIVE WITH THE WAVE...AS IT OPENS UP AND PUSHES EASTWARD INTO THE NORTHERN GREAT LAKES BY MONDAY. MEANWHILE...THE GFS KEEPS THE LOW CLOSED LONGER AND IS THUS SLOWER WITH ITS EASTWARD TRACK. THIS MAKES A BIG DIFFERENCE WITH TIMING OF ASSOCIATED COLD FRONT...AS GFS LINGERS THIS BOUNDARY AND RAIN CHANCES UNTIL TUESDAY. SINCE OVERALL SYNOPTIC PATTERN HAS BEEN PROGRESSIVE OVER THE PAST WEEK AND THE GEM SUPPORTS THE ECMWF...WILL BE GOING WITH THE FASTER ECMWF/GEM SOLUTION IN THE EXTENDED. AS A RESULT...WILL BRING LIKELY POPS INTO THE FAR WESTERN CWA SUNDAY AFTERNOON...THEN FURTHER EAST ACROSS THE REMAINDER OF THE AREA SUNDAY NIGHT. WILL THEN BEGIN TO SHIFT THE RAIN CHANCES OUT OF THE PICTURE ON MONDAY...WITH DRY WEATHER RETURNING MONDAY NIGHT AND TUESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1219 PM CDT TUE MAY 12 2015 THICKER STRATOCUMULUS AROUND 3500 FEET CONTINUES TO BREAK UP AND WILL BE MOST PROMINENT AT KCMI/KDEC FOR A COUPLE MORE HOURS. OTHERWISE...GENERAL TREND WILL BE VFR WITH SOME INCREASE IN HIGH CLOUDS LATER THIS AFTERNOON. GUSTY WEST/NORTHWEST WINDS AROUND 25 KNOTS SHOULD BE SETTLING DOWN AFTER ABOUT 23Z...AND WILL GRADUALLY TURN MORE THE NORTH/NORTHEAST OVERNIGHT AS AN AREA OF HIGH PRESSURE MOVES THROUGH THE MIDWEST. AS THE HIGH MOVES FURTHER EAST WEDNESDAY MORNING...WINDS WILL BECOME MORE EASTERLY AND INCREASE TO AROUND 10 KNOTS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEELHART SHORT TERM...BARNES LONG TERM...BARNES AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS CARIBOU ME
614 PM EDT TUE MAY 12 2015 .SYNOPSIS... LOW PRESSURE WILL CONTINUE ACROSS QUEBEC TONIGHT BRINGING A COLD FRONT INTO THE AREA. THE COLD FRONT WILL PUSH THROUGH THE REGION WEDNESDAY MORNING AND OFF THE COAST. HIGH PRESSURE WILL BUILD TOWARD THE REGION LATER WEDNESDAY NIGHT INTO THURSDAY. && .NEAR TERM /THROUGH WEDNESDAY/... 614 PM UPDATE...A LINE OF SHOWERS MOVING OUT OF CENTRAL MAINE WILL QUICKLY MOVE TO THE NEW BRUNSWICK BORDER OVER THE NEXT 1 TO 2 HOURS. CALLS TO WEATHER SPOTTERS INDICATE SOME HEAVY DOWNPOURS...BUT LITTLE WIND. THUS FAR ONLY SOME IN CLOUD LIGHTNING DETECTED. ONCE THIS LINE MOVES OUT OF THE AREA ATTENTION TURNS TO SHOWERS AND THUNDERSTORMS IN QUEBEC THAT WILL DRIFT INTO FAR NORTHERN MAINE OVER THE NEXT FEW HOURS. MAIN ADJUSTMENT WAS TO THE POPS OVER THE NEXT COUPLE OF HOURS TO ACCOUNT FOR THE LINE OF SHOWERS MOVING OUT OF CENTRAL MAINE. PREVIOUS DISCUSSION... ISOLATED THUNDERSTORMS POSSIBLE W/SOME DECENT WIND GUSTS. LOW CLOUDS SLOWLY ERODING ACROSS THE EASTERN AREAS THIS AFTERNOON KEEPING THE LLVLS STABLE WHILE WESTERN AND SW AREAS HAVE BROKEN OUT W/SUNSHINE AND HENCE TEMPS WARMING. THIS HAS ALLOWED FOR THINGS TO DESTABILIZE MORE. 18Z SURFACE ANALYSIS HAD THE WARM FRONT/PRE-FRONTAL BOUNDARY SLOWLY LIFT INTO WESTERN MAINE W/THE COLD FRONT STILL BACK WESTERN QUEBEC. STEADY RAIN HAS ENDED OR MOVED E W/A MORE SHOWERY NATURE OF THE PRECIP SETTING UP. LATEST NAM AND RAP SOUNDINGS SUPPORT DECENT SB/MU CAPE OF 700+ JOULES W/LIS DOWN TO -2 IN THESE AREAS. GOOD SHEAR IN THE 0-6KM LAYER AROUND 35 KTS. SPC MESO ANALYSIS SHOWED DECENT MID LEVEL LAPSE RATES OF 6.5 C/KM HELPING W/INSTABILITY. KEPT ENHANCED WORDING FOR FOR NOW FOR GUSTY WINDS AND HEAVY RAINFALL POTENTIAL. THINGS WILL WIND DOWN ACROSS THE W AND SW THIS EVENING AND THEN SHIFT ACROSS THE NORTHERN AREAS AS THE COLD FRONT APCHS W/LOW PRES PASSING ACROSS SOUTHERN QUEBEC. 12Z UA SHOWED DECENT MID LEVEL COOLING AND STRONG JET FROM 700-500MBS OF AROUND 65 KTS. THOSE STRONGER WINDS COULD GET MIXED DOWN SOME TO THE SFC W/ANY ELEVATED CONVECTION. LEANED W/ENHANCED WORDING FOR THE GUSTY WINDS IN ANY STORMS THROUGH MIDNIGHT. HEAVY RAINFALL POTENTIAL IS POSSIBLE AS WELL W/THE STORMS MOVING PARALLEL TO THE UPPER FLOW. CONVECTIVE POTENTIAL WINDS DOWN AFTER MIDNIGHT W/JUST SHOWERS AND THE BULK OF THE ACTION ACROSS THE NORTHERN TIER. COOLING TO TAKE AFFECT AS NW WIND TAKE OVER THROUGH THE COLUMN. WE ARE TALKING UPPER 30S BACK ACROSS THE WNW BY EARLY WEDNESDAY MORNING W/40S ELSEWHERE. THIS COLD AIR CAN BE SEEN ALREADY SHOWING UP IN NW QUEBEC. WEDNESDAY WILL BE MUCH COOLER W/THE UPPER TROF ACROSS THE REGION W/UPPER 50S NORTH AND WEST WHILE CENTRAL AND DOWNEAST WILL SEE AROUND 60F OR SO DUE TO SOME DOWNSLOPING. IT WILL BE BREEZY W/NW WINDS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... STRONG HIGH PRESSURE WILL BUILD IN FROM THE WEST AND WEDNESDAY NIGHT AND CREST OVER THE REGION EARLY FRIDAY KEEPING THE STATE RELATIVELY DRY. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND SKY CONDITIONS. FOR WINDS HAVE USED THE MOSG25. THE SUPER BLEND WAS USED TO POPULATE THE TEMPERATURE AND DEW POINT GRIDS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... STRONG HIGH PRESSURE WILL MOVE OFF THE EAST COAST LATE FRIDAY. WEAK LOW PRESSURE WILL PASS TO THE SOUTH OF THE REGION SATURDAY. HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT AND CROSS THE REGION TUESDAY. WILL USE THE SUPER BLEND TO POPULATE ALL GRIDS. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... NEAR TERM: MOSTLY VFR EARLYTHIS EVENING AT THE NORTHERN TERMINALS WITH CONDITIONS TO DROP BACK TO MVFR AND IFR W/THE APCHG COLD FRONT TONIGHT. IMPROVEMENT TO MVFR BY MID MORNING AND VFR BY LATE IN THE DAY. KBGR AND KBHB WILL SEE VFR THROUGH TUESDAY. THERE IS A RISK OF AN ISOLATED TSTM THROUGH THIS EVENING W/GUSTY WINDS. SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THROUGH SUNDAY. && .MARINE... NEAR TERM: SCA FOR HAZARDOUS SEAS IS IN EFFECT INCLUDING THE INTRA-COASTAL ZONE. A SWELL BEING GENERATED FROM LEFTOVER TD ANA IS FORECAST LIFT ACROSS THE WATERS LATER THIS EVENING INTO WEDNESDAY. DECIDED ON HEIGHTS UP TO A RANGE OF 6-7 FT W/THE HIGHEST WAVES OVER THE OUTER WATERS. THE INTRA-COASTAL ZONE WILL MOST LIKELY SEE WAVES OF AROUND 5FT W/A 8-9 SECOND PERIOD. FOG WILL BE A NUISANCE FOR NAVIGATION THROUGH TONIGHT. FOR THE WINDS, DECIDED ATTM TO KEEP WIND GUSTS IN THE LOWER 2OS ON WEDNESDAY W/THE NW FLOW. THE OUTER WATERS COULD SEE GUSTS HIT 25 KT FOR A BRIEF PERIOD. SHORT TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR SUSTAINED WINDS WEDNESDAY NIGHT THROUGH FRIDAY THEN TRANSITION TO THE SUPER BLEND WINDS. FOR WAVES: PRIMARY WAVE SYSTEM WILL BE LONG PERIOD SWELL FROM REMNANTS OF TROPICAL DEPRESSION ANA. EXPECT 5 FEET/9-10 SECONDS WAVE HEIGHTS WEDNESDAY NIGHT SUBSIDING DURING THE DAY THURSDAY. WILL CARRY AN SCA EARLY WEDNESDAY EVENING BUT EXPECT SEAS TO SUBSIDE BELOW SCA LATER AT NIGHT AS THE LONG PERIOD WAVE SYSTEM SUBSIDES. WILL USE THE NEAR SHORE WAVE MODEL THROUGH FRIDAY THEN TRANSITION TO THE WAVE WATCH III. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT WEDNESDAY NIGHT FOR ANZ050>052. && $$ NEAR TERM...CB/HEWITT SHORT TERM...MIGNONE LONG TERM...MIGNONE AVIATION...CB/HEWITT/MIGNONE MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
354 PM EDT TUE MAY 12 2015 .SYNOPSIS... LOW PRESSURE WILL CONTINUE ACROSS QUEBEC TONIGHT BRINGING A COLD FRONT INTO THE AREA. THE COLD FRONT WILL PUSH THROUGH THE REGION WEDNESDAY MORNING AND OFF THE COAST. HIGH PRESSURE WILL BUILD TOWARD THE REGION LATER WEDNESDAY NIGHT INTO THURSDAY. && .NEAR TERM /THROUGH WEDNESDAY/... ISOLATED THUNDERSTORMS POSSIBLE W/SOME DECENT WIND GUSTS. LOW CLOUDS SLOWLY ERODING ACROSS THE EASTERN AREAS THIS AFTERNOON KEEPING THE LLVLS STABLE WHILE WESTERN AND SW AREAS HAVE BROKEN OUT W/SUNSHINE AND HENCE TEMPS WARMING. THIS HAS ALLOWED FOR THINGS TO DESTABILIZE MORE. 18Z SURFACE ANALYSIS HAD THE WARM FRONT/PRE-FRONTAL BOUNDARY SLOWLY LIFT INTO WESTERN MAINE W/THE COLD FRONT STILL BACK WESTERN QUEBEC. STEADY RAIN HAS ENDED OR MOVED E W/A MORE SHOWERY NATURE OF THE PRECIP SETTING UP. LATEST NAM AND RAP SOUNDINGS SUPPORT DECENT SB/MU CAPE OF 700+ JOULES W/LIS DOWN TO -2 IN THESE AREAS. GOOD SHEAR IN THE 0-6KM LAYER AROUND 35 KTS. SPC MESO ANALYSIS SHOWED DECENT MID LEVEL LAPSE RATES OF 6.5 C/KM HELPING W/INSTABILITY. KEPT ENHANCED WORDING FOR FOR NOW FOR GUSTY WINDS AND HEAVY RAINFALL POTENTIAL. THINGS WILL WIND DOWN ACROSS THE W AND SW THIS EVENING AND THEN SHIFT ACROSS THE NORTHERN AREAS AS THE COLD FRONT APCHS W/LOW PRES PASSING ACROSS SOUTHERN QUEBEC. 12Z UA SHOWED DECENT MID LEVEL COOLING AND STRONG JET FROM 700-500MBS OF AROUND 65 KTS. THOSE STRONGER WINDS COULD GET MIXED DOWN SOME TO THE SFC W/ANY ELEVATED CONVECTION. LEANED W/ENHANCED WORDING FOR THE GUSTY WINDS IN ANY STORMS THROUGH MIDNIGHT. HEAVY RAINFALL POTENTIAL IS POSSIBLE AS WELL W/THE STORMS MOVING PARALLEL TO THE UPPER FLOW. CONVECTIVE POTENTIAL WINDS DOWN AFTER MIDNIGHT W/JUST SHOWERS AND THE BULK OF THE ACTION ACROSS THE NORTHERN TIER. COOLING TO TAKE AFFECT AS NW WIND TAKE OVER THROUGH THE COLUMN. WE ARE TALKING UPPER 30S BACK ACROSS THE WNW BY EARLY WEDNESDAY MORNING W/40S ELSEWHERE. THIS COLD AIR CAN BE SEEN ALREADY SHOWING UP IN NW QUEBEC. WEDNESDAY WILL BE MUCH COOLER W/THE UPPER TROF ACROSS THE REGION W/UPPER 50S NORTH AND WEST WHILE CENTRAL AND DOWNEAST WILL SEE AROUND 60F OR SO DUE TO SOME DOWNSLOPING. IT WILL BE BREEZY W/NW WINDS. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... STRONG HIGH PRESSURE WILL BUILD IN FROM THE WEST AND WEDNESDAY NIGHT AND CREST OVER THE REGION EARLY FRIDAY KEEPING THE STATE RELATIVELY DRY. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND SKY CONDITIONS. FOR WINDS HAVE USED THE MOSG25. THE SUPER BLEND WAS USED TO POPULATE THE TEMPERATURE AND DEW POINT GRIDS. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... STRONG HIGH PRESSURE WILL MOVE OFF THE EAST COAST LATE FRIDAY. WEAK LOW PRESSURE WILL PASS TO THE SOUTH OF THE REGION SATURDAY. HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY. A COLD FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT AND CROSS THE REGION TUESDAY. WILL USE THE SUPER BLEND TO POPULATE ALL GRIDS. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... NEAR TERM: IFR NORTHERN TERMINALS TO GO VFR THIS EVENING AND THEN DROP BACK TO MVFR AND IFR W/THE APCHG COLD FRONT TONIGHT. IMPROVEMENT TO MVFR BY MID MORNING AND VFR BY LATE IN THE DAY. KBGR AND KBHB WILL SEE VFR THROUGH TUESDAY. THERE IS A RISK OF AN ISOLATED TSTM THROUGH THIS EVENING W/GUSTY WINDS. SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THROUGH SUNDAY. && .MARINE... NEAR TERM: SCA FOR HAZARDOUS SEAS IS IN EFFECT INCLUDING THE INTRA-COASTAL ZONE. A SWELL BEING GENERATED FROM LEFTOVER TD ANA IS FORECAST LIFT ACROSS THE WATERS LATER THIS EVENING INTO WEDNESDAY. DECIDED ON HEIGHTS UP TO A RANGE OF 6-7 FT W/THE HIGHEST WAVES OVER THE OUTER WATERS. THE INTRA-COASTAL ZONE WILL MOST LIKELY SEE WAVES OF AROUND 5FT W/A 8-9 SECOND PERIOD. FOG WILL BE A NUISANCE FOR NAVIGATION THROUGH TONIGHT. FOR THE WINDS, DECIDED ATTM TO KEEP WIND GUSTS IN THE LOWER 2OS ON WEDNESDAY W/THE NW FLOW. THE OUTER WATERS COULD SEE GUSTS HIT 25 KT FOR A BRIEF PERIOD. SHORT TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR SUSTAINED WINDS WEDNESDAY NIGHT THROUGH FRIDAY THEN TRANSITION TO THE SUPER BLEND WINDS. FOR WAVES: PRIMARY WAVE SYSTEM WILL BE LONG PERIOD SWELL FROM REMNANTS OF TROPICAL DEPRESSION ANA. EXPECT 5 FEET/9-10 SECONDS WAVE HEIGHTS WEDNESDAY NIGHT SUBSIDING DURING THE DAY THURSDAY. WILL CARRY AN SCA EARLY WEDNESDAY EVENING BUT EXPECT SEAS TO SUBSIDE BELOW SCA LATER AT NIGHT AS THE LONG PERIOD WAVE SYSTEM SUBSIDES. WILL USE THE NEAR SHORE WAVE MODEL THROUGH FRIDAY THEN TRANSITION TO THE WAVE WATCH III. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT WEDNESDAY NIGHT FOR ANZ050>052. && $$ NEAR TERM...HEWITT SHORT TERM...MIGNONE LONG TERM...MIGNONE AVIATION...HEWITT/MIGNONE MARINE...HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1238 PM CDT TUE MAY 12 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 359 AM CDT TUE MAY 12 2015 HIGH PRESSURE CENTERED ACROSS KS MOVES EAST INTO MISSOURI TODAY. LOW PRESSURE WILL BEGIN TO ORGANIZE ACROSS THE NRN HIGH PLAINS THIS AFTERNOON. THE MODEL CONSENSUS SHOWS STRONG RETURN FLOW DEVELOPING THIS AFTERNOON WITH SOUTH WINDS INCREASING TO 20 TO 30 MPH ACROSS WRN NEB. THESE WINDS SHOULD CONTINUE TONIGHT AS THE LOW LEVEL JET FORMS AND STRENGTHENS TO AROUND 50 KT. THE TEMPERATURE FORECAST TODAY FOLLOWS THE WARMER SIDE OF THE MODEL CONSENSUS. SEVERAL MODELS WERE VERY COLD WITH HIGHS IN THE 60S WHILE THE RAP WAS VERY WARM WITH HIGHS IN THE UPPER 70S. THE FORECAST IS FOR HIGHS IN THE UPPER 60S TO MID 70S. LOWS TONIGHT FALL INTO THE UPPER 40S TO AROUND 50. SOUTH WINDS AT 15 TO 20 MPH SHOULD KEEPS LOWS MILD. LASTLY...THE MODELS SHOW A WEAK DISTURBANCE FIRING THUNDERSTORMS ON THE LARAMIE AND FRONT RANGES LATE THIS AFTERNOON AROUND 21Z WHICH CARRY EAST TOWARD WESTERN NEBRASKA. THE BEST GUESS IS FOR ISOLATED SPRINKLES THIS EVENING. THE GFS WAS THE WET MODEL WHICH ACTUALLY SHOWS SOME MEASURABLE QPF. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 359 AM CDT TUE MAY 12 2015 MODELS CONTINUE TO ADVERTISE A RAPID RETURN OF GULF MOISTURE TAKING PLACE WEDNESDAY...WITH MODELS PROJECTING 850 MB DEW POINTS IN THE 10 TO 12C RANGE BY WEDNESDAY EVENING ACROSS THE REGION. A LARGE UPPER TROUGH WILL BE TAKING SHAPE ALONG THE WEST COAST MID TO LATE WEEK...WITH A LEAD SHORTWAVE EJECTING NORTHEAST THROUGH THE PLAINS AHEAD OF THE TROUGH WEDNESDAY NIGHT INTO THURSDAY. THIS SYSTEM IS SHOWN TO HAVE SOMEWHAT OF A NEGATIVE TILT...WHICH WILL HELP DRAW MOISTURE WESTWARD INTO THE HIGH PLAINS. THE COMBINATION OF STRONG LIFT AND MOISTURE TRANSPORT ON A SOUTHERLY LOW LEVEL JET...CONTINUES TO GIVE CONFIDENCE THAT PRECIPITATION SHOULD RESULT LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. WILL MAINTAIN THE LIKELY POPS ALONG AND EAST OF HIGHWAY 83 WEDNESDAY NIGHT...AND ALSO INTRODUCE EVENING LIKELY POPS ALONG A SURFACE TROUGH ACROSS THE PANHANDLE INTO THE WESTERN SANDHILLS. THE LEAD WAVE QUICKLY PASSES AND MOVES NORTHEAST AWAY FROM THE AREA THURSDAY. ATTENTION THEN TURNS TO THE LONG WAVE TROUGH ALONG THE WEST COAST. MODELS/ENSEMBLES PROJECT THIS TO MOVE EAST AS A CLOSED SYSTEM DURING THE WEEKEND. THE GENERAL CONSENSUS IN THE MODELS AND ENSEMBLE MEAN IS FOR THE CENTER OF THE SYSTEM TO TRACK ACROSS WYOMING INTO SOUTH DAKOTA. THIS PUTS OUR AREA IN THE WARM MOIST SECTOR. INSTABILITY LOOKS TO BE STRONG...AND AS DEEP LAYER SHEAR INCREASES...STRONG TO SEVERE STORMS WILL LIKELY RESULT. WILL INTRODUCE THE POTENTIAL FOR SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER OUTLOOK FOR FRIDAY AND SATURDAY. THE GFS AND ECMWF CONTINUE TO DIFFER SOMEWHAT ON THE LOW LEVEL BOUNDARY PLACEMENT...BUT THE LATEST TREND IS TO HOLD THE DRY LINE BACK TO THE WEST ACROSS WESTERN NEBRASKA INTO WESTERN KANSAS...WHICH WOULD PLACE SEVERE STORM DEVELOPMENT ACROSS THE FORECAST AREA OF WESTERN AND NORTH CENTRAL NEBRASKA. WE WILL LIKELY BE IN THE MIDST OF THE MID LEVEL DRY SLOT SUNDAY AS THE STORM SYSTEM CROSSES THE DAKOTAS...BUT AT LEAST SOME CHANCE FOR SHOWERS IN WRAP AROUND PATTERN ACROSS NORTHERN NEBRASKA. DRY WEATHER FOR MONDAY...THEN MORE CHANCES FOR RAIN NEXT WEEK BEYOND THE FORECAST PERIOD...AS THE NEXT DEEP TROUGH MOVES EAST INTO THE WESTERN CONUS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1238 PM CDT TUE MAY 12 2015 FOR THE 18Z KLBF AND KVTN TAF...HIGH PRESSURE WILL BUILD EAST ACROSS THE MID-MISSISSIPPI VALLEY WITH A BROAD AREA OF LOW PRESSURE DEVELOPING WEST OF THE ROCKIES. THIS WILL INCREASE THE PRESSURE GRADIENT ACROSS WEST CENTRAL NEBRASKA...PROVIDING FOR INCREASING SOUTHERLY WINDS...WHICH WILL CONTINUE THROUGH THE OVERNIGHT HOURS. LLWS MAY BECOME TROUBLESOME ACROSS OUR EASTERN ZONES OVERNIGHT...MAINLY IMPACTING KONL...KBBW...AND POSSIBLY KLBF. OTHERWISE INCREASING CLOUDINESS EARLY ON WEDNESDAY WILL LEAD TO OVC SKIES BY EARLY AFTERNOON. && .HYDROLOGY... ISSUED AT 359 AM CDT TUE MAY 12 2015 THE COMBINATION OF SEASONAL SNOW MELT IN THE UPPER SOUTH PLATTE RIVER BASIN AND RECENT HEAVY PRECIPITATION OVER WESTERN NEBRASKA AND NORTHEAST COLORADO WILL LEAD TO FLOODING ON THE SOUTH PLATTE AND PLATTE RIVERS IN SOUTHWEST NEBRASKA LATER THIS WEEK AND INTO EARLY NEXT WEEK. AT THIS TIME SOME UNCERTAINTY STILL REMAINS WITH THE FORECAST AS KEY UPSTREAM GAUGES IN NORTHEAST COLORADO HAVE YET TO CREST. HOWEVER...LATEST PROJECTIONS CONTINUE TO HIGHLIGHT AN INCREASING THREAT FOR SIGNIFICANT FLOODING TO OCCUR...POTENTIALLY NEAR SEPTEMBER 2013 FLOOD LEVELS. RIVER STAGE FORECASTS WILL BE CLOSELY MONITORED AND UPDATED ONCE MORE UPSTREAM RIVER DATA BECOMES AVAILABLE. PERSONS THAT LIVE IN VULNERABLE AREAS ALONG THE SOUTH PLATTE RIVER AND PLATTE RIVER IN SOUTHWEST NEBRASKA SHOULD PAY CLOSE ATTENTION TO FLOOD FORECASTS IN THE COMING DAYS AND BE PREPARED TO TAKE PROPER ACTION. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...TAYLOR AVIATION...JACOBS HYDROLOGY...MARTIN/TAYLOR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
646 PM EDT TUE MAY 12 2015 .SYNOPSIS... SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED LATE TODAY AHEAD OF A COLD FRONT TONIGHT. LESS HUMID AIR WILL ARRIVE WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH PRESSURE MOVES OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 620 PM TUESDAY...SOME RE-ADJUSTMENTS OF THIS EVENING AND OVERNIGHT POPS BASED ON LATEST TSTORM ACTIVITY BREAKING OUT ACROSS THE EXTREME WESTERN PORTIONS OF THE ILM CWA AHEAD OF THE APPROACHING COLD FRONT. IF THE ACTIVITY HOLDS TOGETHER AS IT PUSHES EASTWARD...AND MEETS UP WITH THE SEA BREEZE...FURTHER ACTIVITY COULD BLOSSOM. ALTHOUGH AT THIS TIME VIA KLTX 88D AND VIS SAT IMAGERY...IT LOOKS LIKE THE SEA BREEZE HAS REACHED ITS MAXIMUM PUSH INLAND. STILL...ENOUGH SFC FORCING SHOULD AID CONTINUING THE CONVECTION AS IT PUSHES EASTWARD BEFORE THE MARINE INFLUENCES BEHIND THE SEA BREEZE LIKELY PARTIALLY OR ENTIRELY EXTINGUISHES IT. OVERALL...KEPT POPS IN THE LOWER CHANCE CATEGORY. CURRENT MIN TEMP FORECAST LOOKS AOK...NO CHANGES NEEDED AT THIS TIME. PREVIOUS...................................................... AS OF 318 PM TUESDAY...VERY HOT DAY ONGOING ACROSS THE CWA WITH LOTS OF 90-91 READINGS AND MID 60S TO AROUND 70 DEWPOINTS. THE SEA BREEZE IS CLEARLY EVIDENT AS A LINE OF MODERATE CU FROM ABOUT BURGAW TO TABOR CITY TO GEORGETOWN...MAKING MUCH MORE PROGRESS NW INTO NC ON THE RESULTANT. THIS WILL CONTINUE TO SLOWLY PUSH WEST THIS AFTN...BUT BASED OFF THE STRUGGLE OF THE CU TO GAIN VERTICAL DEPTH...HAVE CUT BACK POP TO JUST A VERY ISOLATED SHOWER ALONG THE SEA BREEZE. PRE-FRONTAL TROUGH WILL APPROACH THIS EVENING AND IS LIKELY TO BE OUR ONLY CHANCE FOR TSTMS TODAY. HRRR IS ALL OF A SUDDEN VERY AGGRESSIVE WITH CONVECTION ALONG IT THIS EVENING AND RACING EAST OFFSHORE EARLY IN THE NIGHTTIME PERIOD. WHILE THIS TIMING IS APPROPRIATE...HAVE A HARD TIME PLACING MORE THAN 40 POP ANYWHERE FOR ISOLATED TO SCATTERED TSTMS...MORE LIKE THE WRF SOLUTION. THINK THE MID-LEVELS ARE JUST A BIT TOO WARM FOR STRONG CONVECTION...BUT THE SPC SWODY1 MAINTAINS A MRGL RISK FOR OUR NC ZONES AND CANNOT RULE OUT AN ISOLATED WIND GUST AS INVERTED-V SOUNDINGS ARE FORECAST AHEAD OF THIS TROUGH. PRE-FRONTAL TROUGH WILL MOVE OFFSHORE...AND THEN SUBSEQUENT COLD FRONT WILL THEN TRAVERSE THE CWA LATE TONIGHT...MOVING OFFSHORE BY DAWN WEDNESDAY. NO CONVECTION EXPECTED ALONG THE BOUNDARY...BUT A SIGNIFICANT AIR MASS CHANGE WITH QUICKLY COOLING TEMPS AND MUCH DRIER DEWPOINTS WILL OCCUR. LOWS TONIGHT WILL RANGE FROM AROUND 60 WELL INLAND...TO ABOUT 65 AT THE COAST. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 318 PM TUESDAY...CHANGING OF THE GUARD SO TO SPEAK IN TERMS OF AIR MASS REPLACEMENT THIS PERIOD...AS A COLD FRONT MIGRATES OFF THE COAST AROUND DAYBREAK WEDNESDAY. POST FRONTAL N WIND WILL TEND TO NE WEDNESDAY ACCOMPANIED BY LOWERING DEWPOINTS IN THE 50S MAKING FOR CONSIDERABLY LESS MUGGINESS...WITH MAXIMUMS OF UPPER 70S TO LOWER 80S WITH SUN. EARLY THURSDAY SEASONABLY COOL MINIMUMS OF UPPER 50S TO LOWER 60S...MILDEST COAST. A COOLER DAY SETTING UP THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES DROPS SOUTHEAST TOWARD THE CAROLINAS...SUPPLYING A DOSE OF COOL AIR ADVECTION. MINIMUMS EARLY FRIDAY SIMILAR TO THURSDAY UPPER 50S TO LOWER 60S. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 318 PM TUESDAY...TRANSITION PERIOD AS HIGH PRESSURE MOVES OFFSHORE FRIDAY AND RETURN FLOW RESUMES ACROSS THE AREA. THIS WILL BRING A TREND UPWARD IN TEMPERATURES AND HUMIDITY WITH AN INCREASING CHANCE OF SHOWERS/TSTMS AS A COLD FRONT GRADUALLY APPROACHES FROM THE WEST THIS WEEKEND. THE FRONT MAY STALL OVER THE AREA EARLY NEXT WEEK...OFFERING HIGH HUMIDITY AND EVEN A BETTER CHANCE OF PCPN INTO EARLY NEXT WEEK. THIS REGIME SHOULD RESULT IN TEMPERATURES NEAR OR SLIGHTLY ABOVE CLIMATE STANDARDS FOR MIDDLE MAY. && .AVIATION /00Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...SOME ISOLATED CONVECTION IS TRYING TO FORM AHEAD OF A COLD FRONT THAT WILL SWING THROUGH THE REGION OVERNIGHT. SINCE WE ARE LOSING OUR AFTERNOON HEATING...DO NOT THINK THE CONVECTION WILL GET BETTER ORGANIZED BUT THERE COULD BE A BRIEF BUMP UP AS THE CONVECTION ENCOUNTERS THE SEA BREEZE BOUNDARY IN A COUPLE OF HOURS. OVERNIGHT...LOOK FOR ANY LEFTOVER CONVECTION TO REACH THE COAST BY 05Z. WINDS WILL SHIFT TO THE NORTH BEHIND THE COLD FRONT AFTER MIDNIGHT...WITH MODERATE NORTHEAST FLOW EXPECTED FOR WEDNESDAY WITH LESS HUMID CONDITIONS. EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 PM TUESDAY...SSW-SW WINDS 15 TO 20 KT TO PREVAIL WELL INTO TONIGHT...DIMINISHING TO 10-15 KT AS THE COLD FRONT APPROACHES...AND LIKELY VEERING TO THE NW-N AROUND 15 KT BY DAYBREAK WED AFTER FROPA. SIGNIFICANT SEAS WILL RUN 2 TO 4 FT...HIEST ACROSS THE WATERS FROM CAPE FEAR SOUTH TO LITTLE RIVER INLET WHERE THE FETCH IS GREATEST GIVEN THE WIND DIRECTION. A 1 TO 2 FOOT 7-8 SECOND PERIOD GROUND SWELL REMAINS IDENTIFIABLE...BUT WIND DRIVEN WAVES AT 4 TO 5 SECONDS WILL DOMINATE THE SIGNIFICANT SEAS. PREVIOUS..................................................... AS OF 318 PM TUESDAY...HIGH PRESSURE OFFSHORE CONTINUES TO DRIVE SW WINDS ACROSS THE WATERS THIS AFTN. SPEEDS ARE GENERALLY AROUND 15 KTS...BUT ARE REACHING 20 KTS WITH SOME BACKING TO THE SOUTH NEAR THE COAST THANKS TO THE LOCAL SEA BREEZE ENHANCEMENT. THE SEA BREEZE WILL EASE WITH LOSS OF HEATING...LEAVING 15 KT WINDS ACROSS THE WATERS TONIGHT...ALONG WITH PERSISTENT 2-4 FT SEAS. THE WAVE PERIOD WILL BE AROUND 7 SEC...SHORTER IN THE MORE WIND-DRIVEN SEA BREEZE NEAR SHORE. A COLD FRONT WILL CROSS THE WATERS TOWARDS DAWN ON WEDNESDAY...TURNING THE WINDS QUICKLY TO THE N/NW AND DRIVING THE HIGHER WAVES AWAY FROM SHORE. A FEW SHOWERS AND TSTMS MAY ACCOMPANY THIS FRONT...BUT WIDESPREAD CONVECTION IS NOT CURRENTLY ANTICIPATED. SHORT TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 318 PM TUESDAY...A COLD FRONTAL PASSAGE TO BRING A WINDSHIFT TO NORTH ON THE WATERS WEDNESDAY...TENDING TO NE AND ENE HEADING INTO LATER WEDNESDAY AND THURSDAY. NO ADVISORIES BUT NE GUSTS TO 20 KT EXPECTED EARLY THURSDAY AS HIGH PRESSURE BUILDS FROM THE NW. SEAS 2-3 FEET WEDNESDAY WILL BUILD TO 3-4 FEET THURSDAY. NO TSTMS OR VISIBILITY RESTRICTIONS ON THE 0-20 NM WATERS EXPECTED WED/THU/ .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 318 PM TUESDAY...A TRANSITION TO A BERMUDA HIGH PRESSURE PATTERN AS HIGH PRESSURE MOVES OFFSHORE AND RETURN SW WINDS PREVAIL BEGINNING FRIDAY AND PERSISTING THROUGH THE WEEKEND. WARMING DAYTIME TEMPERATURES WILL DRIVE A SEA BREEZE AND AFTERNOON GUSTS TO 20 KT SHOULD BE EXPECTED NEAR SHORE OVER THE WEEKEND. ISOLATED SHOWERS AND TSTMS SHOULD ALSO BE EXPECTED INTO THE WEEKEND AS S AND SW WINDS INTRODUCE ADDITIONAL MOISTURE INTO THE REGION. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...DCH/JDW SHORT TERM...MJC LONG TERM...SHK AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
642 PM EDT TUE MAY 12 2015 .SYNOPSIS... SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED LATE TODAY AHEAD OF A COLD FRONT TONIGHT. LESS HUMID AIR WILL ARRIVE WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH PRESSURE MOVES OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 620 PM TUESDAY...SOME RE-ADJUSTMENTS OF THIS EVENING AND OVERNIGHT POPS BASED ON LATEST TSTORM ACTIVITY BREAKING OUT ACROSS THE EXTREME WESTERN PORTIONS OF THE ILM CWA AHEAD OF THE APPROACHING COLD FRONT. IF THE ACTIVITY HOLDS TOGETHER AS IT PUSHES EASTWARD...AND MEETS UP WITH THE SEA BREEZE...FURTHER ACTIVITY COULD BLOSSOM. ALTHOUGH AT THIS TIME VIA KLTX 88D AND VIS SAT IMAGERY...IT LOOKS LIKE THE SEA BREEZE HAS REACHED ITS MAXIMUM PUSH INLAND. STILL...ENOUGH SFC FORCING SHOULD AID CONTINUING THE CONVECTION AS IT PUSHES EASTWARD BEFORE THE MARINE INFLUENCES BEHIND THE SEA BREEZE LIKELY PARTIALLY OR ENTIRELY EXTINGUISHES IT. OVERALL...KEPT POPS IN THE LOWER CHANCE CATEGORY. CURRENT MIN TEMP FORECAST LOOKS AOK...NO CHANGES NEEDED AT THIS TIME. PREVIOUS...................................................... AS OF 318 PM TUESDAY...VERY HOT DAY ONGOING ACROSS THE CWA WITH LOTS OF 90-91 READINGS AND MID 60S TO AROUND 70 DEWPOINTS. THE SEA BREEZE IS CLEARLY EVIDENT AS A LINE OF MODERATE CU FROM ABOUT BURGAW TO TABOR CITY TO GEORGETOWN...MAKING MUCH MORE PROGRESS NW INTO NC ON THE RESULTANT. THIS WILL CONTINUE TO SLOWLY PUSH WEST THIS AFTN...BUT BASED OFF THE STRUGGLE OF THE CU TO GAIN VERTICAL DEPTH...HAVE CUT BACK POP TO JUST A VERY ISOLATED SHOWER ALONG THE SEA BREEZE. PRE-FRONTAL TROUGH WILL APPROACH THIS EVENING AND IS LIKELY TO BE OUR ONLY CHANCE FOR TSTMS TODAY. HRRR IS ALL OF A SUDDEN VERY AGGRESSIVE WITH CONVECTION ALONG IT THIS EVENING AND RACING EAST OFFSHORE EARLY IN THE NIGHTTIME PERIOD. WHILE THIS TIMING IS APPROPRIATE...HAVE A HARD TIME PLACING MORE THAN 40 POP ANYWHERE FOR ISOLATED TO SCATTERED TSTMS...MORE LIKE THE WRF SOLUTION. THINK THE MID-LEVELS ARE JUST A BIT TOO WARM FOR STRONG CONVECTION...BUT THE SPC SWODY1 MAINTAINS A MRGL RISK FOR OUR NC ZONES AND CANNOT RULE OUT AN ISOLATED WIND GUST AS INVERTED-V SOUNDINGS ARE FORECAST AHEAD OF THIS TROUGH. PRE-FRONTAL TROUGH WILL MOVE OFFSHORE...AND THEN SUBSEQUENT COLD FRONT WILL THEN TRAVERSE THE CWA LATE TONIGHT...MOVING OFFSHORE BY DAWN WEDNESDAY. NO CONVECTION EXPECTED ALONG THE BOUNDARY...BUT A SIGNIFICANT AIR MASS CHANGE WITH QUICKLY COOLING TEMPS AND MUCH DRIER DEWPOINTS WILL OCCUR. LOWS TONIGHT WILL RANGE FROM AROUND 60 WELL INLAND...TO ABOUT 65 AT THE COAST. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... AS OF 318 PM TUESDAY...CHANGING OF THE GUARD SO TO SPEAK IN TERMS OF AIR MASS REPLACEMENT THIS PERIOD...AS A COLD FRONT MIGRATES OFF THE COAST AROUND DAYBREAK WEDNESDAY. POST FRONTAL N WIND WILL TEND TO NE WEDNESDAY ACCOMPANIED BY LOWERING DEWPOINTS IN THE 50S MAKING FOR CONSIDERABLY LESS MUGGINESS...WITH MAXIMUMS OF UPPER 70S TO LOWER 80S WITH SUN. EARLY THURSDAY SEASONABLY COOL MINIMUMS OF UPPER 50S TO LOWER 60S...MILDEST COAST. A COOLER DAY SETTING UP THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES DROPS SOUTHEAST TOWARD THE CAROLINAS...SUPPLYING A DOSE OF COOL AIR ADVECTION. MINIMUMS EARLY FRIDAY SIMILAR TO THURSDAY UPPER 50S TO LOWER 60S. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 318 PM TUESDAY...TRANSITION PERIOD AS HIGH PRESSURE MOVES OFFSHORE FRIDAY AND RETURN FLOW RESUMES ACROSS THE AREA. THIS WILL BRING A TREND UPWARD IN TEMPERATURES AND HUMIDITY WITH AN INCREASING CHANCE OF SHOWERS/TSTMS AS A COLD FRONT GRADUALLY APPROACHES FROM THE WEST THIS WEEKEND. THE FRONT MAY STALL OVER THE AREA EARLY NEXT WEEK...OFFERING HIGH HUMIDITY AND EVEN A BETTER CHANCE OF PCPN INTO EARLY NEXT WEEK. THIS REGIME SHOULD RESULT IN TEMPERATURES NEAR OR SLIGHTLY ABOVE CLIMATE STANDARDS FOR MIDDLE MAY. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...THE SEA BREEZE HAS DEVELOPED WITH PRETTY MUCH A STEADY S-SSW WIND AROUND 13KT AT THE COASTAL TERMINALS. WINDS AT KFLO/KLBT ARE SW 8-12KT. TERMINALS ARE VFR...AND THE IFR CIGS JUST NORTH OF CRE SHOULD REMAIN JUST AWAY FROM THE TERMINAL. CONFIDENCE IS MODERATE TO HIGH KCRE WILL REMAIN VFR. A COLD FRONT WILL APPROACH AND MOVE THROUGH THE TERMINALS THIS TAF PERIOD. IT WILL BE UNSTABLE ENOUGH FOR SHOWERS AND THUNDERSTORMS TO DEVELOP THIS EVENING. APPEARS THE BEST AREA FOR DEVELOPMENT WILL BE BETWEEN THE INLAND AND COASTAL TERMINALS WHERE SURFACE WINDS ARE CONVERGING...AND LATEST HIGH RES GUIDANCE SUGGESTS THIS WILL NOT EVEN REACH THE COASTAL TERMINALS AS IT STABILIZES BEHIND THE SEA BREEZE. CONVECTION SHOULD TAPER OFF IN THE EVENING. THE COLD FRONT WILL MOVE THROUGH DURING OVERNIGHT HOURS. PRECIPITATION WILL DROP AFTER THE FRONT MOVES THROUGH. VFR WILL CONTINUE INTO THE MORNING HOURS WITH VFR/NE WINDS AFTER SUNRISE. EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 PM TUESDAY...SSW-SW WINDS 15 TO 20 KT TO PREVAIL WELL INTO TONIGHT...DIMINISHING TO 10-15 KT AS THE COLD FRONT APPROACHES...AND LIKELY VEERING TO THE NW-N AROUND 15 KT BY DAYBREAK WED AFTER FROPA. SIGNIFICANT SEAS WILL RUN 2 TO 4 FT...HIEST ACROSS THE WATERS FROM CAPE FEAR SOUTH TO LITTLE RIVER INLET WHERE THE FETCH IS GREATEST GIVEN THE WIND DIRECTION. A 1 TO 2 FOOT 7-8 SECOND PERIOD GROUND SWELL REMAINS IDENTIFIABLE...BUT WIND DRIVEN WAVES AT 4 TO 5 SECONDS WILL DOMINATE THE SIGNIFICANT SEAS. PREVIOUS..................................................... AS OF 318 PM TUESDAY...HIGH PRESSURE OFFSHORE CONTINUES TO DRIVE SW WINDS ACROSS THE WATERS THIS AFTN. SPEEDS ARE GENERALLY AROUND 15 KTS...BUT ARE REACHING 20 KTS WITH SOME BACKING TO THE SOUTH NEAR THE COAST THANKS TO THE LOCAL SEA BREEZE ENHANCEMENT. THE SEA BREEZE WILL EASE WITH LOSS OF HEATING...LEAVING 15 KT WINDS ACROSS THE WATERS TONIGHT...ALONG WITH PERSISTENT 2-4 FT SEAS. THE WAVE PERIOD WILL BE AROUND 7 SEC...SHORTER IN THE MORE WIND-DRIVEN SEA BREEZE NEAR SHORE. A COLD FRONT WILL CROSS THE WATERS TOWARDS DAWN ON WEDNESDAY...TURNING THE WINDS QUICKLY TO THE N/NW AND DRIVING THE HIGHER WAVES AWAY FROM SHORE. A FEW SHOWERS AND TSTMS MAY ACCOMPANY THIS FRONT...BUT WIDESPREAD CONVECTION IS NOT CURRENTLY ANTICIPATED. SHORT TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 318 PM TUESDAY...A COLD FRONTAL PASSAGE TO BRING A WINDSHIFT TO NORTH ON THE WATERS WEDNESDAY...TENDING TO NE AND ENE HEADING INTO LATER WEDNESDAY AND THURSDAY. NO ADVISORIES BUT NE GUSTS TO 20 KT EXPECTED EARLY THURSDAY AS HIGH PRESSURE BUILDS FROM THE NW. SEAS 2-3 FEET WEDNESDAY WILL BUILD TO 3-4 FEET THURSDAY. NO TSTMS OR VISIBILITY RESTRICTIONS ON THE 0-20 NM WATERS EXPECTED WED/THU/ .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 318 PM TUESDAY...A TRANSITION TO A BERMUDA HIGH PRESSURE PATTERN AS HIGH PRESSURE MOVES OFFSHORE AND RETURN SW WINDS PREVAIL BEGINNING FRIDAY AND PERSISTING THROUGH THE WEEKEND. WARMING DAYTIME TEMPERATURES WILL DRIVE A SEA BREEZE AND AFTERNOON GUSTS TO 20 KT SHOULD BE EXPECTED NEAR SHORE OVER THE WEEKEND. ISOLATED SHOWERS AND TSTMS SHOULD ALSO BE EXPECTED INTO THE WEEKEND AS S AND SW WINDS INTRODUCE ADDITIONAL MOISTURE INTO THE REGION. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...DCH/JDW SHORT TERM...MJC LONG TERM...SHK AVIATION...DL
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
318 PM EDT TUE MAY 12 2015 .SYNOPSIS... SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED LATE TODAY AHEAD OF A COLD FRONT TONIGHT. LESS HUMID AIR WILL ARRIVE WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH PRESSURE MOVES OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 318 PM TUESDAY...VERY HOT DAY ONGOING ACROSS THE CWA WITH LOTS OF 90-91 READINGS AND MID 60S TO AROUND 70 DEWPOINTS. THE SEA BREEZE IS CLEARLY EVIDENT AS A LINE OF MODERATE CU FROM ABOUT BURGAW TO TABOR CITY TO GEORGETOWN...MAKING MUCH MORE PROGRESS NW INTO NC ON THE RESULTANT. THIS WILL CONTINUE TO SLOWLY PUSH WEST THIS AFTN...BUT BASED OFF THE STRUGGLE OF THE CU TO GAIN VERTICAL DEPTH...HAVE CUT BACK POP TO JUST A VERY ISOLATED SHOWER ALONG THE SEA BREEZE. PRE-FRONTAL TROUGH WILL APPROACH THIS EVENING AND IS LIKELY TO BE OUR ONLY CHANCE FOR TSTMS TODAY. HRRR IS ALL OF A SUDDEN VERY AGGRESSIVE WITH CONVECTION ALONG IT THIS EVENING AND RACING EAST OFFSHORE EARLY IN THE NIGHTTIME PERIOD. WHILE THIS TIMING IS APPROPRIATE...HAVE A HARD TIME PLACING MORE THAN 40 POP ANYWHERE FOR ISOLATED TO SCATTERED TSTMS...MORE LIKE THE WRF SOLUTION. THINK THE MID-LEVELS ARE JUST A BIT TOO WARM FOR STRONG CONVECTION...BUT THE SPC SWODY1 MAINTAINS A MRGL RISK FOR OUR NC ZONES AND CANNOT RULE OUT AN ISOLATED WIND GUST AS INVERTED-V SOUNDINGS ARE FORECAST AHEAD OF THIS TROUGH. PRE-FRONTAL TROUGH WILL MOVE OFFSHORE...AND THEN SUBSEQUENT COLD FRONT WILL THEN TRAVERSE THE CWA LATE TONIGHT...MOVING OFFSHORE BY DAWN WEDNESDAY. NO CONVECTION EXPECTED ALONG THE BOUNDARY...BUT A SIGNIFICANT AIR MASS CHANGE WITH QUICKLY COOLING TEMPS AND MUCH DRIER DEWPOINTS WILL OCCUR. LOWS TONIGHT WILL RANGE FROM AROUND 60 WELL INLAND...TO ABOUT 65 AT THE COAST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 318 PM TUESDAY...CHANGING OF THE GUARD SO TO SPEAK IN TERMS OF AIR MASS REPLACEMENT THIS PERIOD...AS A COLD FRONT MIGRATES OFF THE COAST AROUND DAYBREAK WEDNESDAY. POST FRONTAL N WIND WILL TEND TO NE WEDNESDAY ACCOMPANIED BY LOWERING DEWPOINTS IN THE 50S MAKING FOR CONSIDERABLY LESS MUGGINESS...WITH MAXIMUMS OF UPPER 70S TO LOWER 80S WITH SUN. EARLY THURSDAY SEASONABLY COOL MINIMUMS OF UPPER 50S TO LOWER 60S...MILDEST COAST. A COOLER DAY SETTING UP THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES DROPS SOUTHEAST TOWARD THE CAROLINAS...SUPPLYING A DOSE OF COOL AIR ADVECTION. MINIMUMS EARLY FRIDAY SIMILAR TO THURSDAY UPPER 50S TO LOWER 60S. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 318 PM TUESDAY...TRANSITION PERIOD AS HIGH PRESSURE MOVES OFFSHORE FRIDAY AND RETURN FLOW RESUMES ACROSS THE AREA. THIS WILL BRING A TREND UPWARD IN TEMPERATURES AND HUMIDITY WITH AN INCREASING CHANCE OF SHOWERS/TSTMS AS A COLD FRONT GRADUALLY APPROACHES FROM THE WEST THIS WEEKEND. THE FRONT MAY STALL OVER THE AREA EARLY NEXT WEEK...OFFERING HIGH HUMIDITY AND EVEN A BETTER CHANCE OF PCPN INTO EARLY NEXT WEEK. THIS REGIME SHOULD RESULT IN TEMPERATURES NEAR OR SLIGHTLY ABOVE CLIMATE STANDARDS FOR MIDDLE MAY. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...THE SEA BREEZE HAS DEVELOPED WITH PRETTY MUCH A STEADY S-SSW WIND AROUND 13KT AT THE COASTAL TERMINALS. WINDS AT KFLO/KLBT ARE SW 8-12KT. TERMINALS ARE VFR...AND THE IFR CIGS JUST NORTH OF CRE SHOULD REMAIN JUST AWAY FROM THE TERMINAL. CONFIDENCE IS MODERATE TO HIGH KCRE WILL REMAIN VFR. A COLD FRONT WILL APPROACH AND MOVE THROUGH THE TERMINALS THIS TAF PERIOD. IT WILL BE UNSTABLE ENOUGH FOR SHOWERS AND THUNDERSTORMS TO DEVELOP THIS EVENING. APPEARS THE BEST AREA FOR DEVELOPMENT WILL BE BETWEEN THE INLAND AND COASTAL TERMINALS WHERE SURFACE WINDS ARE CONVERGING...AND LATEST HIGH RES GUIDANCE SUGGESTS THIS WILL NOT EVEN REACH THE COASTAL TERMINALS AS IT STABILIZES BEHIND THE SEA BREEZE. CONVECTION SHOULD TAPER OFF IN THE EVENING. THE COLD FRONT WILL MOVE THROUGH DURING OVERNIGHT HOURS. PRECIPITATION WILL DROP AFTER THE FRONT MOVES THROUGH. VFR WILL CONTINUE INTO THE MORNING HOURS WITH VFR/NE WINDS AFTER SUNRISE. EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 318 PM TUESDAY...HIGH PRESSURE OFFSHORE CONTINUES TO DRIVE SW WINDS ACROSS THE WATERS THIS AFTN. SPEEDS ARE GENERALLY AROUND 15 KTS...BUT ARE REACHING 20 KTS WITH SOME BACKING TO THE SOUTH NEAR THE COAST THANKS TO THE LOCAL SEA BREEZE ENHANCEMENT. THE SEA BREEZE WILL EASE WITH LOSS OF HEATING...LEAVING 15 KT WINDS ACROSS THE WATERS TONIGHT...ALONG WITH PERSISTENT 2-4 FT SEAS. THE WAVE PERIOD WILL BE AROUND 7 SEC...SHORTER IN THE MORE WIND-DRIVEN SEA BREEZE NEAR SHORE. A COLD FRONT WILL CROSS THE WATERS TOWARDS DAWN ON WEDNESDAY...TURNING THE WINDS QUICKLY TO THE N/NW AND DRIVING THE HIGHER WAVES AWAY FROM SHORE. A FEW SHOWERS AND TSTMS MAY ACCOMPANY THIS FRONT...BUT WIDESPREAD CONVECTION IS NOT CURRENTLY ANTICIPATED. SHORT TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 318 PM TUESDAY...A COLD FRONTAL PASSAGE TO BRING A WINDSHIFT TO NORTH ON THE WATERS WEDNESDAY...TENDING TO NE AND ENE HEADING INTO LATER WEDNESDAY AND THURSDAY. NO ADVISORIES BUT NE GUSTS TO 20 KT EXPECTED EARLY THURSDAY AS HIGH PRESSURE BUILDS FROM THE NW. SEAS 2-3 FEET WEDNESDAY WILL BUILD TO 3-4 FEET THURSDAY. NO TSTMS OR VISIBILITY RESTRICTIONS ON THE 0-20 NM WATERS EXPECTED WED/THU/ .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 318 PM TUESDAY...A TRANSITION TO A BERMUDA HIGH PRESSURE PATTERN AS HIGH PRESSURE MOVES OFFSHORE AND RETURN SW WINDS PREVAIL BEGINNING FRIDAY AND PERSISTING THROUGH THE WEEKEND. WARMING DAYTIME TEMPERATURES WILL DRIVE A SEA BREEZE AND AFTERNOON GUSTS TO 20 KT SHOULD BE EXPECTED NEAR SHORE OVER THE WEEKEND. ISOLATED SHOWERS AND TSTMS SHOULD ALSO BE EXPECTED INTO THE WEEKEND AS S AND SW WINDS INTRODUCE ADDITIONAL MOISTURE INTO THE REGION. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...JDW SHORT TERM...MJC LONG TERM...MJC AVIATION...MRR/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
124 PM EDT TUE MAY 12 2015 .SYNOPSIS... SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AHEAD OF A COLD FRONT. LESS HUMID AIR ARRIVES ON WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH PRESSURE MOVES OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...HOT AND HUMID DAY ONGOING ACROSS THE CWA EVEN AT THIS EARLY HOUR. AFTER STARTING FROM LOWS AROUND 70...TEMPS ARE SHOOTING UP QUICKLY THIS MORNING THANKS TO 950MB TEMPS CLOSE TO 22C ON THE 8AM KCHS U/A SOUNDING. HIGH PRESSURE CENTERED WELL OFFSHORE IS PUMPING RETURN FLOW INTO THE CAROLINAS...WHICH IS STRENGTHENING WARM ADVECTION IN A PRE-FRONTAL AIRMASS. THE COMBINATION OF THIS HEAT AND DEWPOINT TEMPS AROUND 70 WILL DRIVE HEAT INDICES INTO THE MID 90S AWAY FROM THE COAST TODAY...THE MOST UNCOMFORTABLE DAY OF 2015 SO FAR. THIS HUMID AIR MASS WILL DRIVE INSTABILITY THIS AFTN...AND CONVECTION IS ONCE AGAIN EXPECTED ACROSS THE AREA. VERY STEEP LR`S UP TO 800MB WILL DRIVE RAPID UPDRAFTS...AND SBCAPE IS FORECAST TO RISE TO AROUND 3000 J/KG...POSSIBLY HIGHER RIGHT ALONG THE SEA BREEZE. THIS WILL SERVE AS THE FUEL FOR STORMS TODAY...WHICH SHOULD DEVELOP ALONG THE SEA BREEZE...AND THEN LATER ALONG A PRE-FRONTAL TROUGH APPROACHING FROM THE WEST. WHILE RESIDUAL BOUNDARIES MAY FIRE WEAK STORMS...MID LEVEL TEMPS ARE NOT EXCEEDINGLY COOL (-8C AT 500MB) SO WIDESPREAD STRONG UPDRAFTS ARE NOT ANTICIPATED. STILL...ENOUGH FORCING WILL DRIVE PARCELS UP INTO DECENT HAIL-ZONE INSTABILITY...AND AN INVERTED-V TYPE SIGNATURE IS PROGGED WELL INLAND AHEAD OF THE PRE-FRONTAL TROUGH. BULK-SHEAR VALUES STRUGGLE TO AROUND 20 KTS...SO WIDESPREAD STORM ORGANIZATION IS UNLIKELY...BUT PULSE STORMS AND AT LEAST SOME LINEAR FEATURES ALONG THE PRE-FRONTAL TROUGH WILL HAVE THE POTENTIAL TO PRODUCE AN ISOLATED WIND GUST OR LARGE HAIL STONE THIS AFTN. HIGH-RES HRRR AND NSSL WRF SUGGEST ONLY ISOLATED STORMS UNTIL THE PRE-FRONTAL TROUGH THIS EVENING...WHICH WILL BE THE PRIMARY DRIVER OF CONVECTION TODAY. BY THIS EVENING HOWEVER...WE BEGIN TO LOSE HEATING...AND HAVE CAPPED POP IN THE HIGH CHC RANGE. HIGHEST PROBABILITY FOR STORMS LOOKS TO BE ACROSS THE MIDDLE-PART OF THE CWA WHERE THE WESTWARD ADVANCING SEA BREEZE WILL INTERACT WITH THE EASTWARD MOVING TROUGH. CONVECTION WILL WANE AFTER DARK...AND LITTLE FANFARE IS EXPECTED WITH THE ACTUAL FROPA TONIGHT. HOWEVER...A SIGNIFICANT AIRMASS CHANGE WILL ACCOMPANY THIS FRONT...WITH MUCH DRIER AIR AND LOWS DROPPING INTO THE MID 60S AT THE COAST...AROUND 60 WELL INLAND. ALSO NEED TO NOTE A PERSISTENT AREA OF SEA-STRATUS FROM ABOUT NORTH MYRTLE BEACH TO BALD HEAD ISLAND. SHELF WATERS MUST BE JUST COOL ENOUGH TO TAP INTO THE IDEALIZED RESIDENCE PARCEL TIMES ENCOUNTERED BY THE W/SW WINDS IN ORDER TO SATURATE IN THIS AREA. THE COMBINATION OF THE BACKING WINDS WITHIN THE SEA BREEZE...AS WELL AS SIGNIFICANT HEATING JUST INLAND...SHOULD BREAK APART THIS STRATUS BY EARLY AFTN...BUT IT IS UNLIKELY THE NEAR-COAST AREA HERE WILL EXPERIENCE THE HOT/HUMID/SUNNY DAY GOING ON ELSEWHERE ACROSS THE CWA. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY... SOME VERY PLEASANT WEATHER EXPECTED THROUGH THE PERIOD. HIGH PRESSURE WELL TO OUR NORTH WILL SHOW LITTLE MOVEMENT WEDNESDAY WHILE THE TUESDAY NIGHT COLD FRONT STALLS WELL TO OUR SOUTH. IN BETWEEN THE TWO WE WILL SEE A N TO NE FLOW LOCALLY THAT WILL BRING SOME MUCH LOWER DEWPOINTS. A MILD LEVEL RIDGE WILL BE JUST TO OUR WEST ALLOWING FOR DEEP LAYER DRY AIR AND AMPLE SUNSHINE. ON THURSDAY THE HIGH WILL MOVE CLOSER TO THE REGION KEEPING TEMPERATURES A BIT BELOW CLIMATOLOGY. A LITTLE MOISTURE RETURN MAY GET UNDERWAY THURSDAY NIGHT AS THE HIGH MOVES FURTHER TO THE EAST, MAINLY OVER WESTERN ZONE. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...RETURN FLOW ON FRIDAY AND SATURDAY AS HIGH PRESSURE SITES OFF THE COAST. THE MID LEVEL RIDGE WILL BE OVERHEAD HOWEVER PRECLUDING DEEP MOISTURE AND CONFINING IT TO THE LOWER LEVELS. SO WHILE A STRAY SHOWER OR THUNDERSTORM CANNOT BE RULED OUT ANY COVERAGE SHOULD BE MINIMAL. OVER THE WEEKEND AND EVEN INTO MONDAY FOR THAT MATTER THE MID LEVEL RIDGING APPEARS TO RESURGE. DESPITE THIS THE GFS AND ECMWF BOTH DEPICT AN INCREASE IN PRECIPITATION COVERAGE. WHILE THE CONTINUED MOISTENING OF THE LOW LEVELS DOES IN FACT ARGUE FOR THIS THE MID LEVEL DRYNESS PROBABLY MEANS THAT ITS RATHER SUBTLE. TEMPERATURES MEANWHILE WILL GROW WARMER EACH DAY AND NIGHT. && .AVIATION /18Z TUESDAY THROUGH SUNDAY /... AS OF 18Z...THE SEA BREEZE HAS DEVELOPED WITH PRETTY MUCH A STEADY S- SSW WIND AROUND 13KT AT THE COASTAL TERMINALS. WINDS AT KFLO/KLBT ARE SW 8-12KT. TERMINALS ARE VFR...AND THE IFR CIGS JUST NORTH OF CRE SHOULD REMAIN JUST AWAY FROM THE TERMINAL. CONFIDENCE IS MODERATE TO HIGH KCRE WILL REMAIN VFR. A COLD FRONT WILL APPROACH AND MOVE THROUGH THE TERMINALS THIS TAF PERIOD. IT WILL BE UNSTABLE ENOUGH FOR SHOWERS AND THUNDERSTORMS TO DEVELOP THIS EVENING. APPEARS THE BEST AREA FOR DEVELOPMENT WILL BE BETWEEN THE INLAND AND COASTAL TERMINALS WHERE SURFACE WINDS ARE CONVERGING...AND LATEST HIGH RES GUIDANCE SUGGESTS THIS WILL NOT EVEN REACH THE COASTAL TERMINALS AS IT STABILIZES BEHIND THE SEA BREEZE. CONVECTION SHOULD TAPER OFF IN THE EVENING. THE COLD FRONT WILL MOVE THROUGH DURING OVERNIGHT HOURS. PRECIPITATION WILL DROP AFTER THE FRONT MOVES THROUGH. VFR WILL CONTINUE INTO THE MORNING HOURS WITH VFR/NE WINDS AFTER SUNRISE. EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM TUESDAY...HIGH PRESSURE OFFSHORE IS THE DOMINANT SYNOPTIC FEATURE ACROSS THE WATERS TODAY...DRIVING SW FLOW AND WINDS OF 10-15 KTS ACROSS THE WATERS. LOCAL ENHANCEMENTS OF UP TO 20 KTS...ALONG WITH A BACKING IN DIRECTION TO THE SOUTH...IS LIKELY ALONG THE SEA BREEZE THROUGH THE AFTN AS WELL. OTHER THAN SOME CHOPPY WATERS WITHIN THE NEAR SHORE WATERS THANKS TO THE SEA BREEZE...WAVE HEIGHTS ARE EXPECTED TO PERSIST AT 2-4 FT WITH A 6-7 SEC PERIOD DOMINANT. A COLD FRONT WILL CROSS THE WATERS LATE TONIGHT TURNING WINDS TO THE N/NW AT AROUND 15 KTS...AND PUSHING THE HIGHEST SEAS AWAY FROM THE COAST. SHORT TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 3 AM TUESDAY... TUESDAY NIGHT`S FROPA WILL BRING A NORTHERLY FLOW ON WEDNESDAY. SURFACE HIGH REMAINS UP IN THE GREAT LAKES SO THE FLOW WILL BE QUITE LIGHT LOCALLY AND SEAS LIKELY JUST 2 TO 3 FT. JUST A SLIGHT VEER WEDNESDAY NIGHT WITH FLOW POSSIBLY GOING LIGHT AND VARIABLE FOR A TIME. THE HIGH EXTENDS JUST SLIGHTLY SOUTH ON THURSDAY WHILE PROGRESSING EAST. NE WINDS COULD INCREASE BY A CATEGORY AND BECOME A LITTLE GUSTY. THE COAST- PARALLEL FLOW WILL PRECLUDE MUCH BUILDING OF SEAS HOWEVER. .LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3 AM TUESDAY... THE HIGH TO OUR NORTH PROGRESSES FURTHER EAST ON FRIDAY LEADING TO MORE VEERING LOCALLY. FRIDAY MAY SEE ONSHORE/EASTERLY FLOW MOST OF THE DAY WHILE A SOUTHERLY COMPONENT TRIES TO GET ESTABLISHED MAINLY OVER SOUTHERN ZONES. ON SATURDAY WE TRANSITION TO A FAIRLY NORMAL RETURN FLOW AROUND HIGH PRESSURE OFF THE EAST COAST. NOT A BERMUDA HIGH THOUGH WHICH TYPICALLY BRINGS SOUTHWESTERLY FLOW...THE WEEKEND WILL LIKELY SEE SOUTHEAST INSTEAD. THERE COULD BE A VERY GRADUAL INCREASE IN WAVE PERIOD AS A SWELL BECOMES ESTABLISHED. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...JDW SHORT TERM...MBB LONG TERM...MBB AVIATION...MRR/JDW MARINE...JDW/MBB
AREA FORECAST DISCUSSION
NWS NORMAN OK
1248 PM CDT TUE MAY 12 2015 .AVIATION... 18Z TAFS...VFR CONDITIONS EXPECTED MUCH OF THE TAF PERIOD. FROM 06Z THROUGH 12Z WED...LOW LEVEL MOISTURE WILL INCREASE...RESULTING MVFR/IFR CIGS SPREADING FROM SW TO NE ACROSS THE REGION...ALONG WITH LIGHT TO MODERATE RAINFALL. RAIN MAY BECOME HEAVY AT TIMES DURING THE DAY WED...WITH VSBYS LESS THAN 2 MILES...BUT CONFIDENCE IN THESE VSBYS IS TOO LOW TO MENTION IN TAFS. FOR NOW WILL GO WITH PREVAILING -RA AT SOUTHWESTERN TERMINALS...WHERE CONFIDENCE IN RAIN IS HIGHER. && .PREV DISCUSSION... /ISSUED 1100 AM CDT TUE MAY 12 2015/ UPDATE... ADJUSTMENTS TO CLOUD COVER AND TEMPERATURES. DISCUSSION... ALTHOUGH MID-HIGH CLOUDS WILL THIN SOMEWHAT FROM WEST TO EAST THROUGH THE AFTERNOON...MOST AREAS OUTSIDE OF FAR NORTH/WEST OKLAHOMA WILL STAY MOSTLY CLOUDY TODAY AND WILL KEEP TEMPS FROM GETTING TOO WARM. INCREASED CLOUD COVER AND LOWERED HIGHS A FEW DEGREES NEAR AND SOUTH OF OKC. A FEW SPRINKLES MAY MOVE INTO WESTERN NORTH TEXAS THIS AFTERNOON BUT MAIN RAIN EVENT STILL APPEARS TO COMMENCE AFTER MIDNIGHT TONIGHT AND MAINLY DURING THE DAY TOMORROW. FLASH FLOOD WATCH WILL BE CONTINUED FOR LATE TONIGHT AND TOMORROW. LATEST RUN OF MODELS LOOKS FAVORABLE FOR HEAVIER RAIN AXIS TO BE FARTHER WEST...SOME OF WHICH WILL BE JUST OUTSIDE OF CURRENT WATCH. HOWEVER...AREAS WEST OF THE FLASH FLOOD WATCH CAN TAKE MUCH MORE RAIN THAN THE RAIN SOAKED CENTRAL/SOUTHEAST OKLAHOMA. WE WILL TAKE A CLOSER LOOK TO EXPANDING THE WATCH BUT IT WILL NOT BE DONE WITH THIS UPDATE. ALTHOUGH SEVERE WEATHER DOES LOOK POSSIBLE FRIDAY...STILL APPEARS THAT SATURDAY COULD BE THE PRIMARY IMPACT DAY FOR SEVERE WEATHER. PREV DISCUSSION... /ISSUED 615 AM CDT TUE MAY 12 2015/ AVIATION... 12Z TAFS...THIN BAND OF SHOWERS AND EMBEDDED STORMS ACROSS CENTRAL AND WEST TEXAS IS EXPECTED TO REMAIN SOUTH OF TAF SITES THROUGH THE DAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH 6Z...BEFORE CEILINGS LOWER ACROSS WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA AS PRECIPITATION DEVELOPS. PREV DISCUSSION... /ISSUED 325 AM CDT TUE MAY 12 2015/ DISCUSSION... EAST TO SOUTHEAST WINDS WILL DEVELOP TODAY AS SURFACE HIGH PRESSURE OVER KANSAS BUILDS EAST. MEANWHILE...CONVECTION ALONG THE EAST TEXAS COAST WILL DELAY THE RETURN OF DEEP MOISTURE NORTHWARD. SCATTERED SHOWERS AND A FEW STORMS HAVE FORMED WITHIN AN AREA OF MID-LEVEL MOISTURE RETURN OVER CENTRAL AND WEST TEXAS. THE HRRR SORTA HAS A HANDLE ON THIS AND GRADUALLY WEAKENS IT DURING THE MORNING...WHILE THE NAM12 IS MORE AGGRESSIVE IN DEVELOPING CONVECTION IN WESTERN NORTH TEXAS. FOR NOW WILL KEEP IN CHANCE POPS FOR OUR TEXAS COUNTIES. ANOTHER HEAVY RAIN EVENT SEEMS LIKELY LATE TUESDAY NIGHT INTO WEDNESDAY. MODELS ARE SIMILAR IN TRACKING A PROGRESSIVE TROUGH ACROSS THE SOUTHWESTERN STATES TONIGHT AND THEN OVER WEST TEXAS AND OKLAHOMA WEDNESDAY INTO EARLY THURSDAY. DEEP MOISTURE IN PLACE OVER SOUTH TEXAS WILL BE TRANSPORTED NORTHWARD TONIGHT INTO WEDNESDAY IN ADVANCE OF THE TROUGH. THE BEST COMBINATION OF UPPER AND LOW LEVEL JET FEATURES...SHOULD FOCUS THE HEAVIEST RAIN OVER WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA EARLY WEDNESDAY...WITH A GRADUALLY SHIFT NORTH AND EAST DURING THE AFTERNOON AND NIGHT. WIDESPREAD 2 INCH RAIN AMOUNTS ARE LIKELY WITH 3 TO 4 INCH TOTALS POSSIBLE. WITH RECENT HEAVY RAIN OVER THE SOUTHERN HALF OF OKLAHOMA AND NORTH TEXAS...FLOODING WILL AGAIN BE A CONCERN. BRIEF SHORTWAVE RIDGING ON THURSDAY WILL KEEP RAIN CHANCES LOW...BUT ANOTHER TROUGH WILL BEGIN TO SHIFT EASTWARD FRIDAY INTO THE WEEKEND. BETTER INSTABILITY IS EXPECTED TO DEVELOP AHEAD OF THIS SYSTEM WHICH WILL RESULT IN AN INCREASE IN SEVERE WEATHER CHANCES FRIDAY INTO SATURDAY. ANOTHER FRONT IS EXPECTED TO PUSH ACROSS THE SOUTHERN PLAINS SUNDAY INTO MONDAY WHICH WILL BRING ANOTHER PERIOD OF DRY WEATHER. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 56 67 62 79 / 30 100 100 30 HOBART OK 56 67 61 80 / 40 100 70 20 WICHITA FALLS TX 59 70 64 82 / 60 100 70 30 GAGE OK 53 66 56 81 / 20 80 60 10 PONCA CITY OK 53 66 59 79 / 10 70 100 50 DURANT OK 59 71 64 80 / 40 80 70 50 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR OKZ007-008-012-013-017>020-022>048-050>052. TX...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR TXZ083>090. && $$ 11/84
AREA FORECAST DISCUSSION...UPDATE
NWS PENDLETON OR
351 PM PDT TUE MAY 12 2015 UPDATED FOR AVIATION DISCUSSION .SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY NIGHT. AN INTENSE AND STATIONARY LOW PRESSURE SYSTEM OVER THE PACNW WILL CONTINUE TO PUMP MOISTURE INTO OUR AREA AND COMBINING THIS WITH DAYTIME HEATING WILL PRODUCE ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING. THE TSRA COULD BECOME STRONG AND PRODUCE GUSTY WINDS AND HAIL WITH THE BEST CHANCES OF THIS OCCURRING OVER THE EASTERN ZONES THAT INCLUDES IN AND AROUND THE BLUE/WALLOWA MOUNTAINS AS WELL AS GRANT COUNTY. ELSEWHERE SHOWERS WILL CONTINUE DEVELOPING ACROSS THE REGION INTO THIS EVENING. AS THE LOW DRIFTS INTO NE OREGON LATER TONIGHT MOISTURE WILL RAP AROUND THIS SYSTEM AND INTO THE EASTERN PORTIONS OF THE AREA AND MODERATE TO HEAVY RAINFALL IS POSSIBLE WITH UP TO AN INCH IN SOME LOCATIONS. THE LOW AND THE BULK OF THE MOISTURE DRIFT NORTH WEDNESDAY MORNING WITH DECREASING CHANCES OF PCPN EXPECTED BUT THE CLOUDS AND SHOWERS WILL PERSIST INTO WEDNESDAY AFTERNOON. A WEAK DISTURBANCE WILL NEAR CENTRAL OREGON WEDNESDAY AFTERNOON THAT COULD PRODUCE AN ISOLD TSRA. OTHERWISE THE BEST CHANCES FOR PCPN SHOULD OCCUR ALONG THE WA/OR CASCADES WEDNESDAY NIGHT AND THURSDAY. BY THURSDAY ANOTHER LOW PRESSURE SYSTEM WILL TRACK TO OUR SOUTH BUT SHOWERS FROM THIS SYSTEM WILL MOVE NORTH AND INTO MOST PORTIONS OF OUR AREA THURSDAY NIGHT. AFTERNOON TEMPERATURES WILL REMAIN COOL TOMORROW BEFORE WARMER TEMPERATURES CAN BE EXPECTED THURSDAY. && .LONG TERM...FRIDAY THROUGH MONDAY NIGHT...MILD YET UNSETTLED WEATHER CAN BE EXPECTED FOR THE EXTENDED. A LOW PRESSURE SYSTEM CENTERED OVER CENTRAL NEVADA WILL CONTINUE TO SPIN UP MOISTURE AND POSSIBLE THUNDERSTORMS TO THE AREA ON FRIDAY. THIS SYSTEM WILL EXIT THE AREA FRIDAY NIGHT WITH ANOTHER LOW MOVING TOWARDS THE PACIFIC COAST ON SATURDAY. THIS LOW IS CURRENTLY FORECAST TO TRACK SOUTH OF THE CWA TOWARDS THE NORTHERN CALIFORNIA COAST THROUGH THE WEEKEND. THIS WILL ALLOW FOR MORE MOISTURE AND INSTABILITY TO BE SPUN UP OVER THE AREA...PROVIDING ANOTHER CHANCE FOR THUNDERSTORMS. THE LOW IS EXPECTED TO SLOWLY MOVE INLAND AND BE CENTERED OVER THE CA/NV BOARDER ON MONDAY NIGHT. OVERALL THE AIRMASS SHOULD BE FAIRLY WARM OVER THE AREA...KEEPING THE TEMPERATURES NEAR TO ABOVE NORMAL. REASONABLE CLOUD COVER CAN BE EXPECTED AT NIGHT AS WELL...ALLOWING FOR MILD NIGHTTIME LOWS. WEBER && .AVIATION...00Z TAFS...MVFR CONDITIONS CAN BE EXPECTED OVER THE NEXT 12-18 HOURS...AS A DEFORMATION BAND IS EXPECTED TO SET UP OVER SOUTHERN WASHINGTON DURING THIS PERIOD. THIS COULD ALLOW FOR PERIODS OF MODERATE RAIN...WITH CIGS POSSIBLY FALLING TO IFR CATEGORIES. FOR NOW PROB30 GROUPS COVER THE PERIODS OF CONCERN. STILL POSSIBLE -TSRA AT KPDT AND KALW FROM 0Z-3Z THIS AFTERNOON...BUT DUE TO LOWER CONFIDENCE HAVE REMOVED THE TEMPO GROUP FOR THUNDER AND JUST LEFT SHOWERS. WINDS WILL RANGE FROM 5 TO 15 KTS...WITH GUSTS UP TO 25 KTS. WEBER && .PRELIMINARY POINT TEMPS/POPS... PDT 45 62 45 64 / 90 70 10 30 ALW 48 65 46 69 / 90 80 10 30 PSC 51 70 46 70 / 90 80 10 20 YKM 49 68 43 70 / 80 70 40 20 HRI 49 69 44 70 / 80 70 10 30 ELN 47 66 41 70 / 90 80 40 20 RDM 35 60 36 59 / 50 30 30 50 LGD 43 62 41 64 / 100 70 20 30 GCD 41 63 39 65 / 80 20 20 50 DLS 48 65 46 71 / 60 50 30 30 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 97/89/89
AREA FORECAST DISCUSSION
NWS PENDLETON OR
225 PM PDT TUE MAY 12 2015 .SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY NIGHT. AN INTENSE AND STATIONARY LOW PRESSURE SYSTEM OVER THE PACNW WILL CONTINUE TO PUMP MOISTURE INTO OUR AREA AND COMBINING THIS WITH DAYTIME HEATING WILL PRODUCE ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING. THE TSRA COULD BECOME STRONG AND PRODUCE GUSTY WINDS AND HAIL WITH THE BEST CHANCES OF THIS OCCURRING OVER THE EASTERN ZONES THAT INCLUDES IN AND AROUND THE BLUE/WALLOWA MOUNTAINS AS WELL AS GRANT COUNTY. ELSEWHERE SHOWERS WILL CONTINUE DEVELOPING ACROSS THE REGION INTO THIS EVENING. AS THE LOW DRIFTS INTO NE OREGON LATER TONIGHT MOISTURE WILL RAP AROUND THIS SYSTEM AND INTO THE EASTERN PORTIONS OF THE AREA AND MODERATE TO HEAVY RAINFALL IS POSSIBLE WITH UP TO AN INCH IN SOME LOCATIONS. THE LOW AND THE BULK OF THE MOISTURE DRIFT NORTH WEDNESDAY MORNING WITH DECREASING CHANCES OF PCPN EXPECTED BUT THE CLOUDS AND SHOWERS WILL PERSIST INTO WEDNESDAY AFTERNOON. A WEAK DISTURBANCE WILL NEAR CENTRAL OREGON WEDNESDAY AFTERNOON THAT COULD PRODUCE AN ISOLD TSRA. OTHERWISE THE BEST CHANCES FOR PCPN SHOULD OCCUR ALONG THE WA/OR CASCADES WEDNESDAY NIGHT AND THURSDAY. BY THURSDAY ANOTHER LOW PRESSURE SYSTEM WILL TRACK TO OUR SOUTH BUT SHOWERS FROM THIS SYSTEM WILL MOVE NORTH AND INTO MOST PORTIONS OF OUR AREA THURSDAY NIGHT. AFTERNOON TEMPERATURES WILL REMAIN COOL TOMORROW BEFORE WARMER TEMPERATURES CAN BE EXPECTED THURSDAY. && .LONG TERM...FRIDAY THROUGH MONDAY NIGHT...MILD YET UNSETTLED WEATHER CAN BE EXPECTED FOR THE EXTENDED. A LOW PRESSURE SYSTEM CENTERED OVER CENTRAL NEVADA WILL CONTINUE TO SPIN UP MOISTURE AND POSSIBLE THUNDERSTORMS TO THE AREA ON FRIDAY. THIS SYSTEM WILL EXIT THE AREA FRIDAY NIGHT WITH ANOTHER LOW MOVING TOWARDS THE PACIFIC COAST ON SATURDAY. THIS LOW IS CURRENTLY FORECAST TO TRACK SOUTH OF THE CWA TOWARDS THE NORTHERN CALIFORNIA COAST THROUGH THE WEEKEND. THIS WILL ALLOW FOR MORE MOISTURE AND INSTABILITY TO BE SPUN UP OVER THE AREA...PROVIDING ANOTHER CHANCE FOR THUNDERSTORMS. THE LOW IS EXPECTED TO SLOWLY MOVE INLAND AND BE CENTERED OVER THE CA/NV BOARDER ON MONDAY NIGHT. OVERALL THE AIRMASS SHOULD BE FAIRLY WARM OVER THE AREA...KEEPING THE TEMPERATURES NEAR TO ABOVE NORMAL. REASONABLE CLOUD COVER CAN BE EXPECTED AT NIGHT AS WELL...ALLOWING FOR MILD NIGHTTIME LOWS. WEBER && .AVIATION...PREVIOUS DISCUSSION...18Z TAFS...MVFR-VFR CONDITIONS OVER THE NEXT 6 HOURS...WITH BETTER CHANCES OF MVFR CONDITIONS OVER THE 0Z-12Z WEDNESDAY TIME PERIOD. DEFORMATION BAND EXPECTED TO SET UP OVER SOUTHERN WASHINGTON DURING THIS PERIOD. THIS COULD ALLOW FOR PERIODS OF MODERATE RAIN...WITH CIGS POSSIBLY FALLING TO IFR CATEGORIES. FOR NOW PROB30 GROUPS COVER THE PERIODS OF CONCERN. POSSIBLE -TSRA AT KPDT AND KALW FROM 0Z-3Z THIS AFTERNOON. HAVE ADDED A TEMPO GROUP TO COVER THE THUNDER. WINDS WILL RANGE FROM 5 TO 15 KTS...WITH GUSTS UP TO 25 KTS. WEBER && .PRELIMINARY POINT TEMPS/POPS... PDT 45 62 45 64 / 90 70 10 30 ALW 48 65 46 69 / 90 80 10 30 PSC 51 70 46 70 / 90 80 10 20 YKM 49 68 43 70 / 80 70 40 20 HRI 49 69 44 70 / 80 70 10 30 ELN 47 66 41 70 / 90 80 40 20 RDM 35 60 36 59 / 50 30 30 50 LGD 43 62 41 64 / 100 70 20 30 GCD 41 63 39 65 / 80 20 20 50 DLS 48 65 46 71 / 60 50 30 30 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 97/89/89
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
136 PM EDT TUE MAY 12 2015 .SYNOPSIS... A WEAK COLD FRONT WILL CROSS OUR AREA TODAY...BEFORE STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH AND REMAINS THROUGH FRIDAY. MOISTURE WILL SPREAD OVER THE AREA AHEAD OF ANOTHER COLD FRONT THAT APPROACHES FROM THE WEST EARLY NEXT WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 130 PM EDT...RADAR HAS BEEN RELATIVELY QUIET EARLY THIS AFTERNOON AS A COLD FRONT SLIPS SLOWLY EASTWARD ACROSS THE REGION. HOWEVER...THE HRRR CONTINUES TO INSIST ON SCATTERED CONVECTIVE DEVELOPMENT ALONG THE PASSING COLD FRONT...WITH PEAK PIEDMONT COVERAGE CIRCA 19Z TO 20Z. THIS IS SOMEWHAT CONSISTENT WITH SB CAPE VALUES OF 1000 TO 1500 J/KG OR GREATER OVER THE ERN PIEDMONT PARTS OF OUR FORECAST AREA...AND ALSO WITH MODEL PROFILES FINALLY OVERCOMING LOW LEVEL CINH AROUND THAT TIME. HOWEVER...THE MID DECK OF CLOUDS HAS GREATLY LIMITED HEATING FOR MUCH OF THE AREA...SO EXPECT THAT ANY ISOLD TO SCT CONVECTION THAT DOES FORM WILL BE RATHER WEAK. OTHERWISE...THE SFC COLD FRONT WILL SETTLE SOUTHEAST OF THE AREA THIS EVENING WITH DRIER HIGH PRESSURE BUILDING OVER TO THE N THROUGH WED. WEAK CHANNELED VORTICITY WILL SLIDE EAST ACROSS THE AREA OVERNIGHT TO PRODUCE SOME HIGH LEVEL CLOUDINESS...BUT WITH LOWER LEVELS DRY. EXPECT MINS TO FALL INTO THE 40S MTNS AND 50S PIEDMONT UNDER WEAK COLD ADVECTION. HEIGHT RISES WILL DEVELOP FROM THE WEST ON WED WITH COMFORTABLE MAXES NEAR CLIMO. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... AT 300 AM EDT TUESDAY...ON WEDNESDAY MORNING AN UPPER TROUGH WILL BE ALONG THE EAST COAST...WHILE AND UPPER RIDGE WILL EXTEND FROM THE GULF STATES TO THE NORTHERN PLAINS. BY THURSDAY THIS NEGATIVELY TILTED RIDGE WILL EXTEND FROM FL TO THE UPPER MS RIVER VALLEY. A STRONG SHORTWAVE WILL ACROSS THE MS RIVER VALLEY ON THURSDAY... WEAKENING AS IT MOVES THROUGH THE RIDGE AXIS ON THURSDAY NIGHT. AT THE SURFACE...ON WEDNESDAY DRY HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL BUILD SOUTH ACROSS OUR AREA IN THE WAKE OF A DEPARTING COLD FRONT. AS THE HIGH MOVES EAST ON THURSDAY...IT EXTENDS SOUTH ALONG THE EAST SLOPES OF THE APPALACHIANS. ON THURSDAY NIGHT...ISENTROPIC UPGLIDE OVER THE HIGH SETS THE STAGE FOR PRECIPITATION...MAINLY OVER THE MOUNTAINS. TEMPERATURES WILL START OUT SLIGHTLY ABOVE NORMAL IN DOWNSLOPE WARMING BEHIND THE FRONT...FALLING TO NEAR NORMAL AS THE COOLER AIR MASS ARRIVES AND LOW LEVEL FLOW VEERS TO NE. && .LONG TERM /FRIDAY THROUGH MONDAY/... AT 135 PM EDT TUESDAY...HIGH CONFIDENCE IS HAD THROUGHOUT THE EXT PERIOD. GOOD INDIVIDUAL RUN TO RUN AND MODEL TO MODEL CONSISTENCY CONTINUES TO INDICATE A BUILDING H5 RIDGE SAT BECOMING REINFORCED ON SUN...THEN SLOWLY BREAKING DOWN MON THROUGH TUE. THERE ARE SOME SUBTLE DIFFERENCES IN IN THE MAGNITUDE AND LOCATION OF THE RIDGE AXIS...HOWEVER NOT ENOUGH DIFFERENCES TO IMPACT THE SENSIBLE WX SIGFNTLY. AT THE SFC...THE MAIN SYNOPTIC FEATURE WILL BE A MID ATL HIGH MERGING WITH THE BERMUDA HIGH CREATING A DOMINATE RIDGING PATTERN ACROSS THE CWFA THROUGH MOST OF THE PERIOD. THIS SETUP WILL KEEP THE MAIN STORM ACTIVITY AND HIGHER DEEP LAYERED INSTABILITY WEST OF THE AREA SAT AND SUN...WITH ISOL/SCT PULSE MTN TSTMS PROBABLE EACH AFTERNOON. THE SFC RIDGE WEAKENS ON MON WHICH WILL ALLOW HIGHER TD/S NORTH AND INCREASE SBCAPE VALUES...ENUF SO FOR MENTION OF DIURNAL THUNDER ACROSS ALL ZONES. WITH LIMITED ULVL ENERGY...THE ATMOS WILL BE IN A TYPICAL SUMMERTIME PATTERN WITH SCT PULSE SEVERE STORMS POSSIBLE EACH AFTERNOON MON/TUE. WITH CONTINUED RIDGING AND SW/LY LLVL FLOW...MAX TEMPS WILL BEGIN RIGHT AROUND NORMAL SAT AND INCREASE TO A COUPLE CATS ABOVE NORMAL BY TUE. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AT KCLT...MID CLOUDS THROUGH MIDDAY HAVE LIMITED HEATING AND INSTABILITY. WILL THUS CONTINUE TO FEATURE ONLY VCSH WITH THE FROPA THIS AFTN. OTHERWISE...EXPECT WSW WINDS TO TOGGLE NW WITH FROPA TOWARD EVENING AND THEN TURN NRLY AND NE OVERNIGHT INTO WED MORNING. ANY CIGS SHOULD BE MID AND HIGH CLOUDS...WITH HIGHER CLOUDS THINNING LATER IN THE PERIOD. ELSEWHERE...MORNING MID CLOUDS HAVE LIMITED INSTABILITY...WHICH SHOULD KEEP FOOTHILL TAFS DRY THIS AFTN. THE FROPA IS THROUGH KAVL...SO DRY AND VFR CONDITIONS WILL CONTINUE THERE AS WELL...WITH OCNL NW GUSTS. FOOTHILL WINDS WILL TOGGLE NW THROUGH LATE AFTN AND NRLY THEN NE OVERNIGHT THROUGH WED MORNING. LITTLE MORE THAN HIGH CLOUDS ARE THEN EXPECTED THE LATER HALF OF THE PERIOD. OUTLOOK...DRIER AIR WILL SETTLE IN UNDER BUILDING HIGH PRESSURE THROUGH THU. RETURN FLOW MOISTURE AROUND THE HIGH PRESSURE MAY ALLOW DIURNAL SHOWERS AND THUNDERSTORMS TO RETURN TO THE AREA FRIDAY THROUGH THE WEEKEND...ESPECIALLY OVER THE MTNS. CONFIDENCE TABLE... 17-23Z 23-05Z 05-11Z 11-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JAT NEAR TERM...HG SHORT TERM...JAT LONG TERM...JAT AVIATION...HG
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1112 AM MDT TUE MAY 12 2015 .UPDATE... ISSUED AT 938 AM MDT TUE MAY 12 2015 15Z SURFACE ANALYSIS HAD FRONTAL BOUNDARY FROM NORTHWEST WY INTO SOUTHWEST SD. LIFT UNDER RIGHT ENTRANCE REGION OF JET STREAK ACROSS THE NORTHERN PLAINS ASSISTING SOME WEAKER RETURNS ON RADAR ACROSS FAR NORTHEAST WY/SOUTHEAST MT/ENTERING NORTHWEST SD. MOST OF IT NOT REACHING THE GROUND...AND LOOKING AT THE 12Z KUNR SOUNDING THERE IS SOME DRY AIR TO OVERCOME. 12Z RAP SHOWS A BIT OF SBCAPE OVER THE HIGHER TERRAIN AS DECENT SOUTHERLY FLOW FEEDS MOISTURE POOLING ALONG THE BOUNDARY SO HAVE ADDED SMALL POPS LATER THIS AFTERNOON FOR THOSE AREAS. && .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT ISSUED AT 300 AM MDT TUE MAY 12 2015 WESTERN CONUS UPPER LEVEL TROUGHING ONGOING THIS MORNING WITH A LOCAL WAA RESPONSE. WEAK LEAD IMPULSE FROM THIS SYSTEM WILL SUPPORT INCREASING MID/HIGH CLOUDS THROUGH MORNING ACROSS THE NORTHERN HALF...WITH A FEW SPRINKLES POSSIBLE ACROSS THE FAR NORTH. MEANWHILE ANOTHER UPPER LEVEL IMPULSE WILL SHIFT NE INTO THE SW CONUS AND SOUTHERN PLAINS. THIS SYSTEM WILL HELP SUPPORT DEEPER MOISTURE NORTH INTO THE AREA THROUGH TONIGHT. ONGOING PRESSURE FALLS PER THE ADVANCING WESTERN CONUS UPPER TROUGH WILL SUPPORT A LLJ TONIGHT WITH SOME FORCING FOR ASCENT PER A SLOW MOVING NW CONUS UPPER TROUGH GRAZING THE NORTHERN PLAINS TONIGHT. STEEP MID LEVEL LAPSE RATE WITH AN FGEN RESPONSE AND INCREASING ELEVATED INSTABILITY NOTED IN MU CAPES WILL SUPPORT A SLIGHT CHANCE SHOWER/TS THREAT ACROSS THE NORTHERN HALF TONIGHT. HIRES MODELS INCLUDING THE NAM SUGGEST AN ISOLD HIGH BASED SHRA/TS COULD DEVELOP OVER NE WY THIS EVENING AS CIN IS MINIMIZED PER INSOLATION...WITH ANY ACTIVITY BEING CARRIED NE BY A DEVELOPING LLJ. DID ADJUST SLIGHT CHANCE POPS SW INTO NE WY AND THE BH AFTER 00Z THIS EVENING FOR THIS...WITH A SLIGHTLY EARLIER START TIME POSSIBLE. LEE SIDE TROUGH WILL SHIFT EAST ACROSS THE FA WED MORNING AND STALL WITH THE SOUTHERN PLAINS IMPULSE SHIFTING NORTH. RENEWED FGEN FROM THIS SYSTEM WILL SUPPORT INCREASING LL CONVERGENCE ALONG AND NEAR THE SFC TROUGH WHICH WILL BE SOMEWHERE ACROSS THE EASTERN FA. INCREASING LL MOISTURE COMBINED WITH DIURNAL INSTABILITY WILL ALLOW INCREASING CHANCES FOR SHRA/TS THERE...WITH OTHER ACTIVITY POSSIBLE OVER THE BH AND NE WY PER DIURNAL HEATING IN THE PRESENCE OF UNSTABLE PROFILES/WEAK CIN. SHRA/TS CHANCES SHOULD INCREASE WED NIGHT AS THE LLJ SUSTAINED WITH ONGOING MOISTURE TRANSPORT AND INCREASING LSA FROM THE EXPECTED IMPULSE. BULK OF FORCING FROM THIS SYSTEM WILL REMAIN SE OF THE FA...INCLUDING THE ASSOCIATED PRECIP CHANCES. HAVE RETAINED HIGH CHANCE POPS...PRECLUDING LIKELY ATTM GIVEN CONVECTIVE COMPONENT TO PRECIP. AS FOR TEMPS...BUMPED HIGHS UP BOTH TODAY AND WED. SNOW PACK HAS ERODED QUITE WELL OVER MUCH OF THE AREA...WITH THE DEEPEST SNOW REMAINING OVER SW SD. STRONG SE WINDS UNDER MAY SUN SHOULD MIX WARMER AIR DOWN WITH NO PROBLEM...THUS HAVE OPTED FOR TEMPS MORE IN LINE WITH GUIDANCE. .LONG TERM...THURSDAY THROUGH MONDAY ISSUED AT 300 AM MDT TUE MAY 12 2015 THE UPPER LEVEL RIDGE WILL MOVE EAST OF THE AREA ON WEDNESDAY. THIS WILL PUT THE AREA IN ACTIVE SOUTHWEST FLOW FOR MID WEEK INTO THE WEEKEND...WITH DAILY CHANCES FOR RAIN SHOWERS AND SOME THUNDERSTORMS. A FAST-MOVING SHORTWAVE WILL SWEEP THROUGH THE CENTRAL CONUS WEDNESDAY NIGHT AND THURSDAY...AND THEN ANOTHER UPPER LOW IS PROGGED TO MOVE ACROSS THE ROCKIES AND INTO THE PLAINS THIS WEEKEND...BRINGING THE BEST CHANCES FOR ADDITIONAL RAINFALL. MODELS ARE INDICATING AROUND A HALF INCH OF QPF BY THE END OF THE WEEK...WITH AN ADDITIONAL INCH OR TWO DURING THE WEEKEND. AS FAR AS TEMPERATURES GO...MORE SPRING LIKE READINGS ARE EXPECTED FROM MID WEEK THROUGH THE WEEKEND. THEREFORE...THE PRECIPITATION SHOULD REMAIN RAIN. && .AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY ISSUED AT 1110 AM MDT TUE MAY 12 2015 GUSTY SOUTHERLY WINDS ACROSS SOUTH CENTRAL SD WILL DIMINISH THIS EVENING. NORTHWEST SD INTO NORTHEAST WY AND THE BLACK HILLS HAVE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS THIS EVENING AND OVERNIGHT. GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH WEDNESDAY MORNING...ALTHOUGH THERE MAY BE SOME LOCAL MFVR CIGS WITH ANY SHOWERS AND THUNDERSTORMS. MODELS ARE IN DISAGREEMENT ON THE POSSIBLE DEVELOPMENT OF FOG ACROSS NORTHEAST WY AND AREAS JUST EAST OF THE BH. COULD BE SOME LOW STRATUS...BUT WILL KEEP TAFS VFR FOR NOW. && .HYDROLOGY... ISSUED AT 300 AM MDT TUE MAY 12 2015 RUNOFF FROM RAIN AND MELTING SNOW IS CAUSING RAPID RISES IN THE LEVEL OF THE WHITE RIVER BETWEEN INTERIOR AND OACOMA. A FLOOD WARNING HAS BEEN ISSUED FOR THAT AREA AS MINOR TO MODERATE FLOODING IS FORECAST TO DEVELOP STARTING TUESDAY MORNING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ UPDATE...HELGESON SHORT TERM...JC LONG TERM...7 AVIATION...POJORLIE HYDROLOGY...JC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 PM CDT TUE MAY 12 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 325 PM CDT TUE MAY 12 2015 FORECAST CONCERNS INCLUDE TEMPERATURES/FROST HEADLINES TONIGHT AND THEN PRECIP/THUNDERSTORM CHANCES THROUGH EARLY NEXT WEEK. DESPITE SOME MODEL TIMING DIFFERENCES FOR THURSDAY/S SYSTEM... 12.12Z MODEL SUITE IN GOOD OVERALL AGREEMENT THROUGH THURSDAY... BUT THEN DIVERGE ON THE CONVECTIVE DETAILS FRIDAY INTO THE WEEKEND. WILL USE A BLENDED MODEL APPROACH. FOR TONIGHT...SURFACE RIDGE AXIS WILL SLIDE ACROSS THE UPPER MS RIVER VALLEY...CENTERED ACROSS THE MN ARROWHEAD INTO NORTH-CENTRAL WI BY 12Z WEDNESDAY. SHOULD SEE SOME INCREASING SOUTHEASTERLY RETURN FLOW ACROSS SOUTHEAST MN AND NORTHEAST IA BY WEDNESDAY MORNING...BUT FOR AREAS EAST OF THE MS RIVER...A WEAK PRESSURE GRADIENT WILL LEAD TO CALM WINDS THROUGH THE NIGHT. IN ADDITION... SIMULATED IR IMAGERY FROM THE NSSL WRF SUGGESTS CURRENT CU WILL DISSIPATE AFTER SUNSET AND CIRRUS ACROSS THE DAKOTAS INTO CENTRAL MN SHOULD REMAIN JUST WEST OF THE FORECAST AREA. AS A RESULT... EXPECT MOSTLY CLEAR SKIES OVERNIGHT ALLOWING FOR MAXIMUM NOCTURNAL COOLING. WILL HOIST A FROST ADVISORY FOR ALL WI COUNTIES EXCEPT FOR BUFFALO/CRAWFORD/GRANT FROM MIDNIGHT THROUGH 7 AM WEDNESDAY WHERE OVERNIGHT TEMPERATURES WILL FALL INTO THE UPPER 20S TO MID 30S. WARM AIR ADVECTION TO INCREASE ON WEDNESDAY ALLOWING TEMPERATURES TO REBOUND BACK INTO THE UPPER 50S TO LOWER 60S. SOUTHEAST WINDS TO INCREASE BETWEEN 10 AND 20 MPH AS SURFACE PRESSURE GRADIENT STRENGTHENS ACROSS THE REGION. SHOULD SEE A FAIR AMOUNT OF SUN AS CLOUDS/PRECIP WILL BE ANCHORED TO PRIMARY WARM FRONTAL BOUNDARY FARTHER NORTH AND WEST ACROSS THE DAKOTAS INTO NORTHERN MN. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 PM CDT TUE MAY 12 2015 RAIN SHOWERS TO INCREASE FROM WEST TO EAST THURSDAY AND THURSDAY NIGHT AS A SHORT-WAVE EJECTS INTO THE UPPER MIDWEST FROM A BROADER PACIFIC TROUGH PARKED ALONG THE WEST COAST. FRONTOGENESIS IS RATHER WEAK WITH THIS SYSTEM...BUT MODEST WARM AIR ADVECTION/ ISENTROPIC LIFT COMBINED WITH INCREASING MOISTURE TRANSPORT WILL RESULT IN A SWATH OF SHOWERS MOVING ACROSS THE REGION. PWATS RISE ABOVE ONE INCH...RESULTING IN WIDESPREAD ACCUMULATIONS OF AT LEAST A HALF INCH AND POSSIBLY AN INCH OR HIGHER IN SOME PLACES. THUNDER WILL NOT ACCOMPANY THIS SYSTEM AS INSTABILITY IS NEARLY NON- EXISTENT. CLOUDS/RAIN WILL KEEP THURSDAY COOL WITH AFTERNOON HIGHS ONLY IN THE UPPER 50S TO LOWER 60S. CONVECTIVE POTENTIAL A BIT MURKY FRIDAY INTO SATURDAY. BEST MOISTURE TRANSPORT FOCUSES ITSELF EITHER EAST OR WEST OF THE FORECAST AREA AND WITH LITTLE UPPER LEVEL DYNAMIC SUPPORT GIVEN STRENGTHENING RIDGE...THUNDERSTORM POTENTIAL IS UNCERTAIN. BEST CHANCE WOULD BE SATURDAY WITH NORTHWARD SURGING WARM FRONT. FOR NOW...WILL FOLLOW SUPERBLEND 20 TO 30 PERCENT CHANCES. OF GREATER CERTAINTY WILL BE INCREASING TEMPERATURES WITH HIGHS IN THE 60S TO LOWER 70S ON FRIDAY RISING INTO THE MID TO UPPER 70S FOR SATURDAY. BETTER CHANCE FOR MORE ORGANIZED THUNDERSTORMS ON SUNDAY WITH APPROACHING PACIFIC TROUGH AND COLD FRONT. MUCAPE AND BULK SHEAR WITHIN THE 0 TO 6 KM LAYER INCREASE TO BETWEEN 1000 AND 1500 J/KG AND 35 TO 40 KTS RESPECTIVELY...BUT ONGOING CONVECTION EARLIER IN THE DAY COULD IMPACT AFTERNOON/EVENING THUNDERSTORM/SEVERE POTENTIAL. THIS IS HIGHLIGHTED IN THE DAY 6 SPC OUTLOOK AND SOMETHING TO WATCH THROUGH THE WEEK. DRIER/COOLER CONDITIONS RETURN MONDAY/ TUESDAY AFTER COLD FRONTAL PASSAGE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1201 PM CDT TUE MAY 12 2015 LOW LEVEL CYCLONIC FLOW AROUND THE SYSTEM EXITING THE NORTHERN GREAT LAKES CONTINUES TO PRODUCE CLOUDS AND FEW SHOWERS ACROSS THE AREA. FOR THE MOST PART...THE SHOWERS HAVE MOVED EAST OF BOTH TAF SITES AND DO NOT ANTICIPATE THESE BEING A PROBLEM FOR THE REMAINDER OF THE AFTERNOON. VISIBLE SATELLITE TRENDS SHOW THE WESTERN PORTION OF THE CLOUD DECK IS BECOMING MORE OPEN CELLULAR SUGGESTING THESE CLOUDS WILL DISSIPATE AT SOME POINT THIS AFTERNOON. BOTH THE 12.15Z RAP AND 12.12Z NAM SUGGEST THE LOW LEVEL MOISTURE FIELD WILL CONTINUE TO SLIDE EAST WITH THE DEPARTING SYSTEM WITH THE CLOUDS SCATTERING OUT BY MID AFTERNOON. UNTIL THIS HAPPENS...THE CEILINGS WILL FLUCTUATE BETWEEN MVFR AND VFR. THESE LOWER CLOUDS WILL TOTALLY DISSIPATE WITH SUNSET THIS EVENING AND THE WINDS WILL DIMINISH AS HIGH PRESSURE BUILDS IN. THIS HIGH WILL QUICKLY SLIP EAST OF THE AREA WEDNESDAY MORNING ALLOWING THE WINDS TO BECOME EAST AND INCREASE TO AROUND 10 KNOTS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM CDT WEDNESDAY FOR WIZ017-029-033-034-041>044-053-055. MN...NONE. IA...NONE. && $$ SHORT TERM...ROGERS LONG TERM...ROGERS AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1201 PM CDT TUE MAY 12 2015 .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 334 AM CDT TUE MAY 12 2015 DEPARTING SHOWERS THIS MORNING/FROST POTENTIAL TONIGHT ARE THE MAIN CONCERNS IN THE SHORT TERM. CURRENT MAP ANALYSIS HAS DEEP 1002MB LOW JUST EAST OF LAKE SUPERIOR. MEANWHILE...WATER VAPOR IMAGERY SHOWS A CLOSED LOW OVER NORTHEAST MN WITH EMBEDDED SHORTWAVE TROUGH ENERGY ROTATING EASTWARD ACROSS SOUTHERN MN/WESTERN WI. RADAR MOSAIC/SURFACE OBS INDICATING SCATTERED SHOWER/DRIZZLE ACTIVITY MAINLY ALONG AND EAST OF THE MISSISSIPPI BEING FORCED BY THESE EMBEDDED TROUGHS. OTHERWISE... TEMPERATURES ACROSS THE AREA WERE IN THE 40S WITH SOMEWHAT BRISK WESTERLY WINDS OF 10-20 MPH. FOR TODAY...THE SURFACE/CLOSED MID-LEVEL LOW WILL SLOWLY PUSH NORTHEAST OF THE AREA THIS MORNING WITH A RIDGE OF HIGH PRESSURE BUILDING IN FROM THE WEST DURING THE AFTERNOON. KEPT SCATTERED SHOWER MENTION IN FOR AREAS ALONG/N OF THE I-90/94 CORRIDORS THROUGH THE MORNING HOURS...BUT THEN IT SHOULD BE DRY THROUGH THE AFTERNOON WITH A SLOW EROSION OF CLOUD COVER FROM SOUTHWEST TO NORTHEAST AS WELL. PLAN ON COOLER THAN NORMAL TEMPERATURES TODAY AS HIGHS ONLY MAKE IT INTO THE UPPER 40S TO THE MIDDLE 50S. THESE COOLER TEMPERATURES AND BRISK NORTHWEST WINDS WILL GIVE AN OVERALL RAW FEEL TO THE DAY. HIGH PRESSURE BUILDS INTO THE AREA TONIGHT FOR PARTLY CLOUDY SKIES AND LIGHT WINDS. THIS WILL LEAD TO SOME CHILLY OVERNIGHT LOWS AS READINGS DIP INTO THE 30S. WITH TEMPERATURES NEARING THE FREEZING MARK...FEEL THE SAND COUNTRY OF CENTRAL WI WOULD BE MOST SUSCEPTIBLE FOR FROST. HOWEVER...THERE IS SOME INDICATION OF HIGH/MID CLOUD STREAMING IN FROM UPSTREAM WARM AIR ADVECTION ACROSS THE DAKOTAS/MN. IN ADDITION...APPEARS THE RIDGE AXIS ACTUALLY PASSES INTO EASTERN WI AFTER MIDNIGHT WHICH MAY BE ENOUGH TO PRODUCE SOME LIGHT EAST WIND TO KEEP LOWER BOUNDARY LAYER MIXED ENOUGH TO PREVENT WIDESPREAD FROST. BASED ON THESE UNCERTAINTIES...HAVE HELD OFF ON FROST HEADLINES FOR NOW AND WILL LET THE DAYSHIFT ASSESS WITH MORE INPUT FROM 12Z MODEL RUNS. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 334 AM CDT TUE MAY 12 2015 PLAN SOME INCREASE IN MID/HIGH CLOUD ON WEDNESDAY IN RESPONSE TO WARM FRONT PUSHING NORTH THROUGH MN. HOWEVER...DRY LOWER LAYERS THANKS TO SURFACE HIGH PRESSURE OVER THE GREAT LAKES IS EXPECTED TO KEEP THE AREA PRECIPITATION-FREE. PLAN ON HIGHS IN THE UPPER 50S TO THE MIDDLE 60S WHICH IS STILL SOME 5 DEGREES BELOW NORMAL. FOR LATER WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...WILL BE WATCHING A MID-LEVEL TROUGH MOVE FROM THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION. FORCING FROM THIS WAVE AND AMPLE 850MB MOISTURE TRANSPORT ENOUGH TO DRIVE THE LIKELIHOOD OF SHOWERS. VERY LIMITED/NIL CAPE SHOULD PREVENT ANY THUNDER POTENTIAL. AS SUCH REMOVED ANY THUNDER MENTION. WITH CLOUD COVER/PRECIPITATION... TEMPERATURES WILL SUFFER A BIT ON THURSDAY AS HIGHS ONLY TOP OFF IN THE UPPER 50S TO THE LOWER 60S. SOME LINGERING SHOWERS STILL POSSIBLE MAINLY FRIDAY MORNING AS THE WAVE DEPARTS THE AREA. WITH BULK OF THIS SHOWER CHANCE IN THE MORNING...APPEARS RIDGE OF HIGH PRESSURE AND INCREASING HEIGHTS WILL RESULT IN HIGH TEMPERATURES WELL INTO THE 60S. AFTER A DRY/PLEASANT SATURDAY WITH HIGHS LOOKING TO PUSH INTO THE 70S...ACTIVE WEATHER PATTERN SETTING UP FOR THE REST OF THE WEEKEND INTO MONDAY. INCREASING SHOWERS AND THUNDERSTORM CHANCES WILL OVERSPREAD THE AREA...MAINLY CENTERED ON SUNDAY AS A POTENT LOW PRESSURE SYSTEM PUSHES TOWARD THE UPPER MISSISSIPPI RIVER VALLEY REGION. APPEARS TO BE AMPLE BULK SHEAR...WITH GFS INDICATING 0-3KM MUCAPE IN THE 500-1000J/KG RANGE SUNDAY AFTERNOON. BASED ON THIS...THE POSSIBILITY IS THERE FOR A FEW SEVERE STORMS. HOWEVER...UNCERTAINTY REMAINS GIVEN LIKELIHOOD OF ONGOING/MUDDLED CONVECTION THROUGH THE DAY ON SUNDAY. WILL BE KEEPING A CLOSE EYE ON THIS SITUATION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON) ISSUED AT 1201 PM CDT TUE MAY 12 2015 LOW LEVEL CYCLONIC FLOW AROUND THE SYSTEM EXITING THE NORTHERN GREAT LAKES CONTINUES TO PRODUCE CLOUDS AND FEW SHOWERS ACROSS THE AREA. FOR THE MOST PART...THE SHOWERS HAVE MOVED EAST OF BOTH TAF SITES AND DO NOT ANTICIPATE THESE BEING A PROBLEM FOR THE REMAINDER OF THE AFTERNOON. VISIBLE SATELLITE TRENDS SHOW THE WESTERN PORTION OF THE CLOUD DECK IS BECOMING MORE OPEN CELLULAR SUGGESTING THESE CLOUDS WILL DISSIPATE AT SOME POINT THIS AFTERNOON. BOTH THE 12.15Z RAP AND 12.12Z NAM SUGGEST THE LOW LEVEL MOISTURE FIELD WILL CONTINUE TO SLIDE EAST WITH THE DEPARTING SYSTEM WITH THE CLOUDS SCATTERING OUT BY MID AFTERNOON. UNTIL THIS HAPPENS...THE CEILINGS WILL FLUCTUATE BETWEEN MVFR AND VFR. THESE LOWER CLOUDS WILL TOTALLY DISSIPATE WITH SUNSET THIS EVENING AND THE WINDS WILL DIMINISH AS HIGH PRESSURE BUILDS IN. THIS HIGH WILL QUICKLY SLIP EAST OF THE AREA WEDNESDAY MORNING ALLOWING THE WINDS TO BECOME EAST AND INCREASE TO AROUND 10 KNOTS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...04