Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/06/16
FORECAST DISCUSSION FOR MORE DETAILS.
&&
.PREV DISCUSSION...AS OF 3:42 AM PDT WEDNESDAY...IT LOOKS LIKE
CLOUD CITY THIS MORNING WITH LOW STRATUS NEAR THE COAST AND
PLENTY OF MID AND HIGH CLOUDS STREAMING OVER THE REGION IN ADVANCE
OF THE INCOMING UPPER LOW. RADAR SHOWING A FEW HIGH RETURNS
OFFSHORE AND OVER THE NORTH BAY...LIKELY VIRGA OR A FEW SPITS OF
LIGHT RAIN. LATEST HRRR AND RAP RUNS SUGGEST THE BEST CHANCE FOR
ANY SHOWERS TODAY WILL BE OVER THE NORTH BAY AND DURING THE
AFTERNOON AS THE LOW GETS CLOSER. MAIN THEME FOR TODAY WILL BE
CLOUDY CONDITIONS WITH HIGHS GENERALLY IN THE 60S TO LOWER 70S.
UPPER LOW WILL SLOWLY APPROACH THE REGION AND THEN DROP WEST OF
THE CENTRAL COAST ON THURSDAY. GRADIENTS ARE LIGHT SO NO STRONG
WINDS OF NOTE. CONTINUED CLOUDY WITH SCATTERED SHOWER CHANCES
CONTINUING ACROSS THE REGION. AGAIN MOST SHOWERS WILL BE LIGHT AND
DUE TO CONVECTIVE NATURE MANY AREAS WILL NOT SEE RAINFALL ON
THURSDAY. IN FACT LATEST 06Z NAM SHOWS MOST OF THE SHOWER ACTIVITY
FORMING OVER THE HIGHER TERRAIN ON THURSDAY AFTERNOON WHICH IS
WHEN WE`LL HAVE A BETTER CHANCE OF SOME ISOLATED T-STORMS AS WELL.
THE CORE OF THE UPPER LOW AND COLD AIR ALOFT STAYS OFFSHORE SO
LOOKS LIKE WE WONT SEE THE BEST INSTABILITY ON THURSDAY AND IF THE
ABUNDANT CLOUD COVER PERSISTS THAT WILL INHIBIT INSTABILITY AS
WELL.
AS THE UPPER LOW HEADS TOWARDS PT CONCEPTION ON FRIDAY MORNING
THE MODELS ARE PAINTING MORE STRATIFORM BUT LIGHT TYPE PRECIP
ROTATING AROUND THE UPPER LOW...ESPECIALLY FROM THE BAY AREA
SOUTHWARD. GIVEN THE SUBTLE RUN TO RUN CHANGES IT REMAINS
DIFFICULT TO PINPOINT EXACTLY WHERE RAIN WILL FALL WITH MANY
LOCATIONS LIKELY REMAINING DRY THROUGH THE PERIOD...HOWEVER FRIDAY
IS LOOKING LIKE THE DAY THAT MAY NEED THE HIGHEST POPS.
06Z NAM AND GFS RUNS SHOW ANOTHER DEFORMATION BAND ROTATING FROM
THE NORTHEAST PART OF THE STATE TOWARDS THE BAY AREA ON SATURDAY
KEEPING THE CHANCE OF SHOWERS IN THE FORECAST ALONG WITH THE BELOW
NORMAL DAYTIME HIGHS IN THE 60S. SO WE HAVE LEGITIMATE BUT LOW END
PRECIP CHANCES THE NEXT FOUR DAYS WITH HIGHER CONFIDENCE FOR BELOW
NORMAL TEMPS THE REST OF THE WEEK AND INTO THE WEEKEND. RAIN
TOTALS BY SATURDAY COULD EXCEED 0.50 IN SOME OF THE WETTER SPOTS
BUT ON AVERAGE TOTALS SHOULD BE MORE AROUND A TENTH OR TWO.
SHOWER THREAT SHOULD FINALLY END BY SATURDAY NIGHT FOLLOWED BY A
GRADUAL WARMING AND DRYING TREND SUNDAY THROUGH EARLY NEXT WEEK.
&&
.AVIATION...AS OF 11:05 AM PDT WEDNESDAY...UPPER LOW IN VICNITY OF
TAF SITES THIS MORNING. THE UPPER CLOUD DECK ASSOCIATED WITH THE
COLD FRONTAL BOUNDARY OF THIS FEATURE WILL GRADUALLY SHIFT
NORTHEAST AND CLEAR OUT THE UPPER LEVEL CIGS BY MID TO LATE
AFTERNOON. THE LOWER CLOUD DECK IS GRADUALLY ATTEMPTING TO PUSH
INLAND LATE THIS MORNING IN THE WAKE OF THE FROPA AND AHEAD OF THE
TROUGH AXIS AS EVIDENT BY MVFR CIGS RETURNING TO THE MONTEREY BAY
REGION. EXPECT THESE LINGERING MVFR CIGS TO EXPERIENCE MIXING
WITHIN NEXT FEW HOURS AND CLEAR OUT THROUGH MIDDAY. FORECAST
MODELS ARE OF LOW QUALITY FOR THE 18Z TAF PACKAGE HOWEVER ALL SEEM
TO INDICATE BORDERLINE MVFR/IFR STRATUS CIGS RETURN BETWEEN 04-10Z
THU DEPENDING ON LOCATION. UPPER LOW WILL BRING VCSH THROUGHOUT
THE FORECAST DURATION. IN SHORT... VFR CIGS THIS AFTERNOON...
MVFR THIS EVENING... AND A FEW SPOTS DROPPING INTO IFR OVERNIGHT.
VICINITY OF KSFO...VFR. ONSHORE WINDS UP TO 15KT THIS AFTERNOON.
MVFR CIGS RETURN AFTER 04Z. LOW CONFIDENCE ON MVFR RETURN.
SFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY TERMINALS...A FEW LINGERING SPOTS OF MVFR THRU 20Z
THIS MORN. BRIEF VFR CLEARING MIDDAY. MVFR/IFR CIGS RETURN
EVENING/OVERNIGHT.
&&
.MARINE...AS OF 11:00 AM PDT WEDNESDAY...AN UPPER LOW IN THE AREA
WILL BRING MODERATE NORTHERLY WINDS IN THE OUTER WATERS NORTH OF
PT REYES. LIGHTER SOUTHWEST WINDS WILL PREVAIL SOUTH OF PT REYES.
THUNDERSTORMS WILL ALSO BE POSSIBLE DUE TO COLD UNSTABLE AIR.
WINDS AND SEAS WILL GRADUALLY INCREASE LATE THIS WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...SF BAY FROM 1 PM
&&
$$
PUBLIC FORECAST: RGASS
AVIATION: DRP
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
439 AM PDT WED MAY 4 2016
.SYNOPSIS....CLOUDY AND COOL TODAY AS AN UPPER LOW APPROACHES AND
PRODUCES SOME NORTH BAY SHOWERS. CHANCE OF SHOWERS CONTINUES
OVERNIGHT INTO THURSDAY ALONG WITH A ISOLATED THUNDERSTORMS AS THE
UPPER LOW WOBBLES AROUND THE CENTRAL COAST. SHOWER AND ISOLATED
THUNDERSTORM THREAT CONTINUES INTO FRIDAY AND LIKELY SATURDAY AS
THE SLOW MOVING LOW IMPACTS THE STATE WITH CONTINUED BELOW NORMAL
TEMPERATURES. DRYING AND WARMING TREND STARTS SUNDAY AND CONTINUES
INTO EARLY NEXT WEEK.
&&
.DISCUSSION...AS OF 3:42 AM PDT WEDNESDAY...IT LOOKS LIKE CLOUD
CITY THIS MORNING WITH LOW STRATUS NEAR THE COAST AND PLENTY OF
MID AND HIGH CLOUDS STREAMING OVER THE REGION IN ADVANCE OF THE
INCOMING UPPER LOW. RADAR SHOWING A FEW HIGH RETURNS OFFSHORE AND
OVER THE NORTH BAY...LIKELY VIRGA OR A FEW SPITS OF LIGHT RAIN.
LATEST HRRR AND RAP RUNS SUGGEST THE BEST CHANCE FOR ANY SHOWERS
TODAY WILL BE OVER THE NORTH BAY AND DURING THE AFTERNOON AS THE
LOW GETS CLOSER. MAIN THEME FOR TODAY WILL BE CLOUDY CONDITIONS
WITH HIGHS GENERALLY IN THE 60S TO LOWER 70S.
UPPER LOW WILL SLOWLY APPROACH THE REGION AND THEN DROP WEST OF
THE CENTRAL COAST ON THURSDAY. GRADIENTS ARE LIGHT SO NO STRONG
WINDS OF NOTE. CONTINUED CLOUDY WITH SCATTERED SHOWER CHANCES
CONTINUING ACROSS THE REGION. AGAIN MOST SHOWERS WILL BE LIGHT AND
DUE TO CONVECTIVE NATURE MANY AREAS WILL NOT SEE RAINFALL ON
THURSDAY. IN FACT LATEST 06Z NAM SHOWS MOST OF THE SHOWER ACTIVITY
FORMING OVER THE HIGHER TERRAIN ON THURSDAY AFTERNOON WHICH IS
WHEN WE`LL HAVE A BETTER CHANCE OF SOME ISOLATED T-STORMS AS WELL.
THE CORE OF THE UPPER LOW AND COLD AIR ALOFT STAYS OFFSHORE SO
LOOKS LIKE WE WONT SEE THE BEST INSTABILITY ON THURSDAY AND IF THE
ABUNDANT CLOUD COVER PERSISTS THAT WILL INHIBIT INSTABILITY AS
WELL.
AS THE UPPER LOW HEADS TOWARDS PT CONCEPTION ON FRIDAY MORNING THE
MODELS ARE PAINTING MORE STRATIFORM BUT LIGHT TYPE PRECIP
ROTATING AROUND THE UPPER LOW...ESPECIALLY FROM THE BAY AREA
SOUTHWARD. GIVEN THE SUBTLE RUN TO RUN CHANGES IT REMAINS
DIFFICULT TO PINPOINT EXACTLY WHERE RAIN WILL FALL WITH MANY
LOCATIONS LIKELY REMAINING DRY THROUGH THE PERIOD...HOWEVER FRIDAY
IS LOOKING LIKE THE DAY THAT MAY NEED THE HIGHEST POPS.
06Z NAM AND GFS RUNS SHOW ANOTHER DEFORMATION BAND ROTATING FROM
THE NORTHEAST PART OF THE STATE TOWARDS THE BAY AREA ON SATURDAY
KEEPING THE CHANCE OF SHOWERS IN THE FORECAST ALONG WITH THE BELOW
NORMAL DAYTIME HIGHS IN THE 60S. SO WE HAVE LEGITIMATE BUT LOW END
PRECIP CHANCES THE NEXT FOUR DAYS WITH HIGHER CONFIDENCE FOR BELOW
NORMAL TEMPS THE REST OF THE WEEK AND INTO THE WEEKEND. RAIN
TOTALS BY SATURDAY COULD EXCEED 0.50 IN SOME OF THE WETTER SPOTS
BUT ON AVERAGE TOTALS SHOULD BE MORE AROUND A TENTH OR TWO.
SHOWER THREAT SHOULD FINALLY END BY SATURDAY NIGHT FOLLOWED BY A
GRADUAL WARMING AND DRYING TREND SUNDAY THROUGH EARLY NEXT WEEK.
&&
.AVIATION...AS OF 4:34 AM PDT WEDNESDAY...TOUGH AND LOW CONFIDENCE
FORECAST THIS MORNING AS AN UPPER LEVEL TROUGH OFF THE COAST
CREEPS EASTWARD. THE TROUGH IS BRINGING A MIXED BAG OF CIGS THIS
MORNING WITH VCSH PASSING THROUGH. CIGS RANGE FROM IFR TO VFR AND
ARE VERY TRANSIENT. DO EXPECT ANY CIGS THIS MORNING TO GRADUALLY
LIFT AS THE TROUGH APPROACHES. WILL KEEP VCSH FOR THE TAFS GIVEN
THE UNCERTAINTY. CIGS RETURN TONIGHT.
VICINITY OF KSFO...VFR TO MVFR CIGS THROUGH THIS MORNING. BETTER
CHC FOR CIGS OVER THE EAST BAY-KOAK. COVERING SOME PATCHY CIGS AT
KSFO WITH A TEMP THIS MORNING. VFR THIS AFTERNOON WITH BREEZY
CONDITIONS.
SFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY TERMINALS...IFR CIGS THIS MORNING...GRADUALLY
LIFTING. VFR THIS AFTERNOON WITH VCSH.
&&
.MARINE...AS OF 03:20 AM PDT WEDNESDAY...AN APPROACHING STORM
SYSTEM WILL BRING UNSETTLED WEATHER TO THE REGION INTO THE
WEEKEND. THUNDERSTORMS WILL ALSO BE POSSIBLE DUE TO COLD UNSTABLE
AIR. WINDS AND SEAS WILL GRADUALLY INCREASE LATE THIS WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...SF BAY FROM 1 PM
&&
$$
PUBLIC FORECAST: R_WALBRUN
AVIATION: MM
MARINE: MM
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
343 AM PDT WED MAY 4 2016
.SYNOPSIS....CLOUDY AND COOL TODAY AS AN UPPER LOW APPROACHES AND
PRODUCES SOME NORTH BAY SHOWERS. CHANCE OF SHOWERS CONTINUES
OVERNIGHT INTO THURSDAY ALONG WITH A ISOLATED THUNDERSTORMS AS THE
UPPER LOW WOBBLES AROUND THE CENTRAL COAST. SHOWER AND ISOLATED
THUNDERSTORM THREAT CONTINUES INTO FRIDAY AND LIKELY SATURDAY AS
THE SLOW MOVING LOW IMPACTS THE STATE WITH CONTINUED BELOW NORMAL
TEMPERATURES. DRYING AND WARMING TREND STARTS SUNDAY AND CONTINUES
INTO EARLY NEXT WEEK.
&&
.DISCUSSION...AS OF 3:42 AM PDT WEDNESDAY...IT LOOKS LIKE CLOUD
CITY THIS MORNING WITH LOW STRATUS NEAR THE COAST AND PLENTY OF
MID AND HIGH CLOUDS STREAMING OVER THE REGION IN ADVANCE OF THE
INCOMING UPPER LOW. RADAR SHOWING A FEW HIGH RETURNS OFFSHORE AND
OVER THE NORTH BAY...LIKELY VIRGA OR A FEW SPITS OF LIGHT RAIN.
LATEST HRRR AND RAP RUNS SUGGEST THE BEST CHANCE FOR ANY SHOWERS
TODAY WILL BE OVER THE NORTH BAY AND DURING THE AFTERNOON AS THE
LOW GETS CLOSER. MAIN THEME FOR TODAY WILL BE CLOUDY CONDITIONS
WITH HIGHS GENERALLY IN THE 60S TO LOWER 70S.
UPPER LOW WILL SLOWLY APPROACH THE REGION AND THEN DROP WEST OF
THE CENTRAL COAST ON THURSDAY. GRADIENTS ARE LIGHT SO NO STRONG
WINDS OF NOTE. CONTINUED CLOUDY WITH SCATTERED SHOWER CHANCES
CONTINUING ACROSS THE REGION. AGAIN MOST SHOWERS WILL BE LIGHT AND
DUE TO CONVECTIVE NATURE MANY AREAS WILL NOT SEE RAINFALL ON
THURSDAY. IN FACT LATEST 06Z NAM SHOWS MOST OF THE SHOWER ACTIVITY
FORMING OVER THE HIGHER TERRAIN ON THURSDAY AFTERNOON WHICH IS
WHEN WE`LL HAVE A BETTER CHANCE OF SOME ISOLATED T-STORMS AS WELL.
THE CORE OF THE UPPER LOW AND COLD AIR ALOFT STAYS OFFSHORE SO
LOOKS LIKE WE WONT SEE THE BEST INSTABILITY ON THURSDAY AND IF THE
ABUNDANT CLOUD COVER PERSISTS THAT WILL INHIBIT INSTABILITY AS
WELL.
AS THE UPPER LOW HEADS TOWARDS PT CONCEPTION ON FRIDAY MORNING THE
MODELS ARE PAINTING MORE STRATIFORM BUT LIGHT TYPE PRECIP
ROTATING AROUND THE UPPER LOW...ESPECIALLY FROM THE BAY AREA
SOUTHWARD. GIVEN THE SUBTLE RUN TO RUN CHANGES IT REMAINS
DIFFICULT TO PINPOINT EXACTLY WHERE RAIN WILL FALL WITH MANY
LOCATIONS LIKELY REMAINING DRY THROUGH THE PERIOD...HOWEVER FRIDAY
IS LOOKING LIKE THE DAY THAT MAY NEED THE HIGHEST POPS.
06Z NAM AND GFS RUNS SHOW ANOTHER DEFORMATION BAND ROTATING FROM
THE NORTHEAST PART OF THE STATE TOWARDS THE BAY AREA ON SATURDAY
KEEPING THE CHANCE OF SHOWERS IN THE FORECAST ALONG WITH THE BELOW
NORMAL DAYTIME HIGHS IN THE 60S. SO WE HAVE LEGITIMATE BUT LOW END
PRECIP CHANCES THE NEXT FOUR DAYS WITH HIGHER CONFIDENCE FOR BELOW
NORMAL TEMPS THE REST OF THE WEEK AND INTO THE WEEKEND. RAIN
TOTALS BY SATURDAY COULD EXCEED 0.50 IN SOME OF THE WETTER SPOTS
BUT ON AVERAGE TOTALS SHOULD BE MORE AROUND A TENTH OR TWO.
SHOWER THREAT SHOULD FINALLY END BY SATURDAY NIGHT FOLLOWED BY A
GRADUAL WARMING AND DRYING TREND SUNDAY THROUGH EARLY NEXT WEEK.
&&
.AVIATION...AS OF 10:54 PM PDT TUESDAY...THE SOUTHERN END OF AN
ELONGATED UPPER LEVEL TROUGH OVER THE EASTERN PACIFIC WILL
GRADUALLY MOVE EAST AND BECOME A CLOSED LOW WEDNESDAY. SATELLITE
SHOWS AREAS OF LOW CLOUDS MOSTLY OVER THE COASTAL WATERS WHILE
MID-HIGH LEVEL CLOUDS CONTINUE TO STREAM IN OFF THE EASTERN
PACIFIC. MARINE LAYER INVERSIONS ARE LIKELY TO STEADILY DEEPEN AND
WEAKEN TONIGHT AND WEDNESDAY AS DEEP LAYERED COOLING TAKES PLACE
IN THE ATMOSPHERE DUE TO THE APPROACHING EPAC TROUGH.
THE WINDS FORECAST IS LOW CONFIDENCE THIS PERIOD. CIGS FORECAST LOW
TO MODERATE CONFIDENCE TONIGHT AND WEDNESDAY.
VICINITY OF KSFO...VFR TO MVFR CIGS LATE TONIGHT AND WEDNESDAY
MORNING. VICINITY SHOWERS AFTER 17Z WEDNESDAY.
SFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY TERMINALS...MVFR CIGS GRADUALLY DEVELOPING THIS EVENING.
LOW CONFIDENCE IFR CIGS FORECAST TONIGHT. PARTIAL CLEARING RETURNS
BY LATE WEDNESDAY MORNING. VICINITY SHOWERS WEDNESDAY AFTERNOON.
&&
.MARINE...AS OF 03:20 AM PDT WEDNESDAY...AN APPROACHING STORM
SYSTEM WILL BRING UNSETTLED WEATHER TO THE REGION INTO THE
WEEKEND. THUNDERSTORMS WILL ALSO BE POSSIBLE DUE TO COLD UNSTABLE
AIR. WINDS AND SEAS WILL GRADUALLY INCREASE LATE THIS WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...SF BAY FROM 1 PM
&&
$$
PUBLIC FORECAST: R_WALBRUN
AVIATION: MM
MARINE: MM
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
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AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
954 AM EDT WED MAY 4 2016
.SYNOPSIS...
LOW PRESSURE WILL CONSOLIDATE OFFSHORE THROUGH THURSDAY BEFORE
MOVING NORTHEASTWARD. MEANWHILE, ANOTHER LOW PRESSURE SYSTEM
DEVELOPS OFF THE MID ATLANTIC COAST THURSDAY NIGHT AND FRIDAY AND
THEN MOVES NORTHEASTWARD THROUGH SATURDAY. A COLD FRONT IS
FORECAST TO MOVE THROUGH SUNDAY MORNING FOLLOWED BY HIGH PRESSURE
BUILDING IN FOR MONDAY AND TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WE HAVE MADE SOME MINOR ADJUSTMENTS TO THE PREVIOUS FORECAST. AN
AREA OF SHOWERS DEVELOPING OVER OUR SOUTHERN COUNTIES AT MID
MORNING WILL INCREASE IN COVERAGE AS IT ADVECTS TO THE NORTH. IT
SHOULD IMPACT THE REMAINDER OF OUR FORECAST AREA DURING THE
BALANCE OF THE MORNING AND INTO THE EARLY TO MID AFTERNOON. THE
LATEST HRRR SEEMS TO BE HANDLING THE OVERALL TREND WELL.
OTHERWISE, LOW CLOUDS WILL PERSIST THROUGH THE DAY ALONG WITH FOG
IN THE ELEVATED TERRAIN. TEMPERATURES WILL REMAIN BELOW NORMAL IN
THE NORTHEASTERLY FLOW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
PWAT DRIES TO 0.75 INCHES AND INSTABILITY ALOFT DECREASES BUT A
CONTD MOIST CYCLONIC CIRCULATION WITH PROBABLY PERIODS OF
MEASURABLE DRIZZLE AND MAYBE A FEW POCKETS OF SHOWERS.
50 50 BLENDED 00Z/4 GFS NAM GUIDANCE. WE SEE THE SPC WRF DRIES US
OUT CONSIDERABLY TONIGHT SO POPS ARE GENERALLY 60 PCT N AND 30-40
PCT SOUTH. BEST CHANCE FOR MEASURABLE MAY BE PRIOR TO MIDNIGHT.
NE WIND GUSTY NEAR 15 MPH... EXPECT 20-25 MPH MONMOUTH COUNTY
COAST.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN OMEGA BLOCK, THEN THIS
PATTERN IS FORECAST TO BREAK DOWN SOME DURING THE SECOND HALF OF
THE WEEKEND AND ESPECIALLY EARLY NEXT WEEK. A FEW WEEKS AGO THERE
WAS AN OMEGA BLOCK IN PLACE, HOWEVER AT THAT TIME WE WERE UNDER
THE RIDGE. THIS GO AROUND WE ARE UNDER THE TROUGH PART OF THE
BLOCK, KEEPING OUR WEATHER COOLER AND UNSETTLED. THE REST OF THE
WEEK WILL THEREFORE BE UNSETTLED WITH SOME IMPROVEMENT DURING THE
WEEKEND, THEN A MORE NOTABLE IMPROVEMENT ANTICIPATED FOR EARLY
NEXT WEEK. WE USED A MODEL BLEND APPROACH FOR THURSDAY INTO
SATURDAY, THEN BLENDED IN THE 00Z WPC GUIDANCE THEREAFTER. SOME
ADJUSTMENTS WERE THEN MADE FOLLOWING ADDITIONAL COLLABORATION WITH
OUR NEIGHBORING OFFICES.
FOR THURSDAY AND FRIDAY...THE OMEGA BLOCK CONTINUES WITH A STRONG
SHORT WAVE CLOSING OFF THE TROUGH AS IT TRACKS FROM THE OHIO
VALLEY AND ACROSS THE SOUTHEASTERN STATES THURSDAY. SOME SHORT
WAVE ENERGY TRACKING NORTHWARD ON THE EAST SIDE OF THE LARGE
TROUGH WILL TEAM UP WITH ISENTROPIC LIFT ABOVE A MARINE LAYER AND
PRODUCE SOME SHOWERS. THURSDAY MORNING HOWEVER COULD ALSO START
WITH SOME DRIZZLE. THE ENTIRE TROUGH AND CLOSED LOW ARE FORECAST
TO BECOME CENTERED ALONG THE EAST COAST FRIDAY WITH THE CLOSED LOW
ITSELF MOVING OVER OUR CWA DURING FRIDAY. THIS WILL DRIVE LOW
PRESSURE OFF THE MID ATLANTIC COAST NORTHWARD ALTHOUGH IT LOOKS TO
NOT DEEPEN CONSIDERABLY. AS THIS OCCURS, THE 500 MB TEMPERATURES
ARE FORECAST TO COOL TO NEAR -24C ON FRIDAY. THIS WOULD PROMOTE
SOME INSTABILITY AND PERHAPS SOME LOW-TOPPED CONVECTION, HOWEVER
CLOUD COVER AND NUMEROUS SHOWERS MAY TEMPER THIS POTENTIAL.
OTHERWISE, AN EASTERLY LOW-LEVEL JET DEVELOPS FRIDAY ACROSS OUR
NORTHEASTERN ZONES THEN THIS PIVOTS NORTH-NORTHWESTWARD DURING THE
AFTERNOON. SOME GUIDANCE IS STRONGER WITH THIS FEATURE WHICH ALSO
DRIVES A BAND OF STRONGER 700-800 MB FRONTOGENETIC FORCING.
OVERALL, THERE LOOKS LIKE DECENT LIFT ON THE NOSE OF THE EASTERLY
JET TO PROMOTE AN AREA OF SHOWERS/RAIN THAT PIVOTS INLAND DURING
FRIDAY. WE MAY NOT SEE ANY BREAKS IN THE CLOUDS, BUT IF THERE ARE
THEN ANY LOW- TOPPED CONVECTION COULD PRODUCE SMALL HAIL GIVEN THE
VERY COLD 500 MB TEMPERATURES. AS OF NOW HOWEVER, ANY INSTABILITY
LOOKS MEAGER. THE SYSTEM THEM MEANDERS OVER OUR AREA FRIDAY NIGHT
AND WHILE THERE SHOULD BE A DECREASE IN THE SHOWER COVERAGE SOME
SHOULD LINGER THROUGH THE NIGHT.
FOR SATURDAY AND SUNDAY...THERE HAS BEEN A GENERAL SLOWING TREND
IN THE GUIDANCE WHEN COMPARING THE MANY MODELS AND ENSEMBLES. THIS
TENDS TO HAPPEN WITH BLOCKING PATTERNS AS IT TAKES LONGER FOR THE
CLOSED LOW TO OPEN UP AND LIFT OUT. THERE ARE CONSIDERABLE
DIFFERENCES AT THE SURFACE ON SATURDAY WHICH LEADS TO PLENTY OF
DETAIL UNCERTAINTIES INCLUDING THE AMOUNT OF RAIN. WE THEREFORE
LEANED CLOSER TO THE WPC GUIDANCE BUT ALSO INCORPORATING SOME
CONTINUITY. THIS MEANS THAT SATURDAY LOOKS TO BE STILL UNSETTLED
WITH SOME SHOWERS STILL HANGING AROUND. THE AMOUNT OF SHOWER
ACTIVITY WILL DEPEND ON THE SHORT WAVE FORCING AROUND THE CLOSED
LOW, HOWEVER PLENTY OF COLD AIR REMAINS ALOFT WHICH WILL HELP WITH
SOME INSTABILITY. THIS SYSTEM SHOULD OPEN UP AND START SHIFTING
EAST SATURDAY NIGHT AS UPSTREAM ENERGY IN THE FORM OF A TROUGH
SLIDES SOUTHEASTWARD FROM THE GREAT LAKES. THIS DRIVES A COLD
FRONT ACROSS OUR AREA MOSTLY SUNDAY MORNING WITH PERHAPS SOME
SHOWERS. THE AIR ALOFT MODIFIES SOME THROUGH THE WEEKEND,
THEREFORE MODERATING DAYTIME TEMPERATURES SHOULD RESULT ESPECIALLY
ON SUNDAY.
FOR MONDAY AND TUESDAY...WE TRANSITION OUT OF AN OMEGA BLOCK
DURING THIS TIME FRAME, RESULTING IN WARMER TEMPERATURES. SOME
GUIDANCE HOWEVER HAS A SHORT WAVE AMPLIFYING A TROUGH ACROSS THE
NORTHEAST MONDAY BEFORE SHIFTING EAST TUESDAY AS A RIDGE
APPROACHES FROM THE WEST. IT APPEARS THAT HIGH PRESSURE BUILDS IN
WITH TIME, HOWEVER ENERGY IN THE PLAINS WILL SEND A DEVELOPING
WARM FRONT TO OUR SOUTH TOWARD OUR AREA TUESDAY. WE KEPT THE
FORECAST DRY ATTM WITH MUCH WARMER AIR BUILDING INTO THE AREA.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...GENERALLY IFR CIGS WITH PATCHY 2-5 MI IN PERIODS OF
SHOWERS. TIMING OF THE RAIN MAINLY LATE MORNING TO MID AFTERNOON.
ISOLATED THUNDER NOT IMPOSSIBLE PER NAM/GFS INSTABILITY ALOFT,
MAINLY DELMARVA OR SE PA/S NJ. NE WIND WITH A FEW GUSTS 15-20 KT
VCNTY KPHL/KACY.
TONIGHT...GENERALLY IFR CIGS WITH PATCHY 2-5 MI IN SCT SHOWERS
DIMINISHING OR ENDING-EXITING NEWD EARLY/PATCHY DRIZZLE-FOG IN THE
WAKE OF THE NEWD SHOWER DEPARTURE. POSSIBLE LIFR CIGS. NE WIND G
15-20 KT POSSIBLE KPHL- KTTN- KACY.
OUTLOOK...
THURSDAY AND FRIDAY...MVFR/IFR CEILINGS PERSIST WITH AN ONSHORE
FLOW AND WEAK LOW PRESSURE NEAR THE COAST. TIMES OF SHOWERS ARE
EXPECTED AS WELL WITH THE MOST WIDESPREAD ACTIVITY OCCURRING ON
FRIDAY. NORTHEAST WINDS MAINLY IN THE 10-15 KNOT RANGE /LESS AT
NIGHT/ WITH THE HIGHER SPEEDS MAINLY CLOSER TO THE COAST.
SATURDAY AND SUNDAY...MVFR/IFR CEILINGS POSSIBLE TO START
SATURDAY, THEN IMPROVEMENTS TO VFR SHOULD OCCUR. SOME SHOWERS ARE
POSSIBLE AS ONE SYSTEM DEPARTS ON SATURDAY, THEN A COLD FRONT
MOVES THROUGH MAINLY SUNDAY MORNING. THE WINDS SHIFT TO THE
NORTHWEST SATURDAY THEN LIGHT SOUTHWEST AT NIGHT, BEFORE SHIFTING
TO THE NORTHWEST AND INCREASING TO 10-15 KNOTS DURING SUNDAY.
&&
.MARINE...
SCA WITH WIND NNJ AND SCA SNJ.
DID NOT ATTM ADD SCA FOR DE COAST SINCE 44009 ON THE OUTER EDGE
OF 455 IS MARGINALLY 5 FT. HOWEVER, AM NOW ANTICIPATING WE`LL NEED
AN SCA IN THE DE ATLC WATERS FOR LATER TONIGHT.
SST`S ARE NEAR OR SLIGHTLY ABOVE NORMAL.
OUTLOOK...
THURSDAY AND FRIDAY...A PERSISTENT ONSHORE FLOW WILL INCREASE FOR
A TIME THURSDAY AS ONE LOW PRESSURE SYSTEM TO OUR SOUTH TRACKS
NORTHEASTWARD. THIS SHOULD RESULT IN WIND GUSTS TO AROUND 25 KNOTS
MAINLY ACROSS THE NORTHERN ATLANTIC COASTAL WATERS THURSDAY. A
SECONDARY LOW PRESSURE SYSTEM ARRIVES DURING FRIDAY WITH A
POSSIBLE 25-30 KNOT NORTHEASTERLY SURGE ACROSS OUR NORTHERN
ATLANTIC COASTAL WATERS. THIS WILL DEPEND ON THE STRENGTH OF AN
EASTERLY LOW-LEVEL JET THAT LIFTS NORTHWARD FRIDAY. THE SEAS ARE
FORECAST TO BE 4-6 FEET MOSTLY FOR THE NEW JERSEY ATLANTIC COASTAL
WATERS, AND THE SMALL CRAFT ADVISORY WAS EXTENDED THROUGH 22Z
THURSDAY. THIS WILL LIKELY NEED TO BE EXTENDED AGAIN, AND SEAS MAY
BUILD TO 5 FEET FARTHER SOUTH THROUGH FRIDAY AND THEREFORE THE
ADVISORY MAY NEED TO BE EXPANDED SOUTHWARD.
SATURDAY AND SUNDAY...A COLD FRONT ARRIVES SUNDAY MORNING WITH
THE WINDS TURNING SOUTHWEST AHEAD OF IT LATE SATURDAY THEN
SHIFTING TO THE NORTHWEST ON SUNDAY. THE WINDS ARE FORECAST TO
INCREASE SUNDAY BEHIND THE FRONTAL PASSAGE, HOWEVER IT APPEARS
THAT SPEEDS ARE BELOW ADVISORY CRITERIA. THE SEAS SHOULD ALSO BE
DROPPING BELOW 5 FEET WITH SOME HELP ON SUNDAY DUE TO THE FLOW
INCREASING FROM OFFSHORE.
&&
.TIDES/COASTAL FLOODING...
CF ADVISORY ISSUED. GUIDANCE SUGGESTIONS OF INCREASED POSITIVE
DEPARTURES COMBINED WITH INCREASING ASTRONOMICAL EVENING TIDES,
LOWERING PRESSURE AND AN INCREASING ONSHORE WIND FAVORED AN
ADVISORY ISSUANCE. IT WILL BE MARGINAL...PROBABLY PLUS OR MINUS .2
FT FROM THRESHOLD.
THIS MORNINGS HIGH TIDE, ESPECIALLY NEAR LEWES WAS .3FT HIGHER
THAN LAST EVENINGS. THAT UPWARD DEPARTURE TREND SHOULD CONTINUE
THE NEXT SEVERAL CYCLES.
THE LONG DURATION NORTHEASTERLY FETCH COMBINED WITH A DAILY
INCREASE IN ASTRONOMICAL TIDES AS WE APPROACH THE NEW MOON FRIDAY
WILL RESULT IN PERIODS OF MINOR EVENING COASTAL FLOODING.
ALL AVAILABLE GUIDANCE SUGGESTS THERE COULD/SHOULD BE SOME MINOR
TIDAL FLOODING AROUND THE TIMES OF HIGH TIDE THIS EVENING,
THURSDAY EVENING, AND MORE LIKELY FRIDAY EVENING.
FOR NOW, ISSUED A COASTAL FLOOD ADVISORY FOR THE NJ/DE COASTS AND
DELAWARE BAY FOR THIS EVENINGS HIGH TIDE.
THERE IS ALSO A SLIGHT CHANCE OF REACHING A MODERATE THRESHOLD
FRIDAY EVENING, BUT CONFIDENCE IS LOW.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EDT
THIS EVENING FOR NJZ012>014-020>027.
DE...COASTAL FLOOD ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EDT
THIS EVENING FOR DEZ002>004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT
THURSDAY FOR ANZ452-453.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ450-451.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG/IOVINO
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1002 AM EDT WED MAY 4 2016
.SYNOPSIS...
ISSUED AT 1002 AM EDT WED MAY 4 2016
SHOWERS WILL BE POSSIBLE THROUGH TONIGHT AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE AREA. WARMER AND DRIER WEATHER CAN BE EXPECTED
FRIDAY WITH HIGHS IN THE 70S.
&&
.UPDATE...
ISSUED AT 1002 AM EDT WED MAY 4 2016
MADE SOME SIGNIFICANT CUTS TO EARLY AFTERNOON POPS FOR THE
MORNING UPDATE. LATEST HRRR AND RAP...SUPPORTED BY WATER VAPOR
AND RADAR MOSAIC...INDICATE A PERIOD OF PRIMARILY DRY CONDITIONS
IN THE WAKE OF PASSING COLD FRONT. PIVOTING DEFORMATION AXIS
APPEARS TO REMAIN OVER MICHIGAN UNTIL LATE AFTERNOON...AT WHICH
POINT IT WILL SWING SOUTHEAST AND BRING ANOTHER ROUND OF LIGHT
RAIN SHOWERS TO OUR AREA THIS EVENING/OVERNIGHT FROM NW TO SE.
ALSO REMOVED THUNDER MENTION. WOULDN`T RULE OUT AN ISOLATED
LIGHTNING STRIKE IN OUR FAR EAST BUT NOTHING OBSERVED SO FAR AND
COLDER AIR IS PUSHING RAPIDLY SOUTHEAST BEHIND THE FRONT...FURTHER
LIMITING ALREADY PALTRY INSTABILITY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 230 AM EDT WED MAY 4 2016
WATER VAPOR IMAGERY DEPICTING DEEP UPPER TROF OVER THE NORTHERN
GREAT LAKES REGION WITH POTENT SHORT WAVE ENERGY APPROACHING THE
BASE OF THE TROF. THIS IS COMBINING WITH STRONG MASS CONVERGENCE
ALONG ASSOCIATED SURFACE COLD FRONT TO GENERATE AREA OF SHOWERS
AND THUNDERSTORMS ACROSS SOUTHERN WISCONSIN MOVING INTO NORTHERN
ILLINOIS TONIGHT. UPPER TROF WILL DIG SOUTH AND CLOSE OFF OVER
SOUTHERN GREAT LAKES BY MIDDAY TODAY...BRINGING 100M HEIGHT FALLS
AND -26C COLD POOL OVER THE AREA WHICH WILL CONTINUE TO SUPPORT
SHOWERS AND THUNDERSTORMS AHEAD OF COLD FRONT THAT WILL SWEEP
ACROSS THE AREA TODAY. EXPECT NON-DIURNAL EARLY MORNING HIGH TEMP
IN WESTERN CWA WITH ARRIVAL OF COLD FRONT AROUND 12Z THIS MORNING
AND STRONG CAA ON GUSTY NW WINDS BEHIND FRONT WILL HAVE TEMPS
STEADY/SLOWLY FALLING DURING THE DAY. PRECIP LINGERS INTO
WEDNESDAY NIGHT AS MOISTURE WRAPS AROUND CYCLONIC FLOW WITH UPPER
LOW DROPPING SOUTHEAST INTO OHIO VALLEY.
&&
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 230 AM EDT WED MAY 4 2016
GRADUALLY IMPROVING CONDITIONS TO BEGIN ON THURSDAY AS INFLUENCE
OF UPPER LOW WANES AS IT CONTINUES SOUTHEAST TOWARD THE MID
ATLANTIC. RIDGING...SURFACE AND ALOFT WILL BUILD IN FROM THE WEST
AND LEAD TO GRADUALLY CLEARING SKIES OVER THE WESTERN CWA BY
THURSDAY AFTERNOON. FAIR WEATHER WILL CONTINUE ON FRIDAY AS TEMPS
WARM BACK INTO THE 70S. NORTHERN STREAM SYSTEM MOVING ACROSS
SOUTHERN CANADA WILL DRAG A WEAK SURFACE COLD FRONT THROUGH THE
AREA ON SATURDAY. UPPER SUPPORT REMAINS DETACHED TO THE NORTH AND
LOW LEVEL FORCING WEAKENS AS FRONT TAKES ON EAST/WEST ORIENTATION
AS IT MOVES THROUGH. FRONT WILL ALSO BE LACKING IN MOISTURE AS
SURFACE HIGH PRESSURE WILL BE ANCHORED OVER GULF OF MEXICO.
THEREFORE LOW CONFIDENCE IN PRECIP DEVELOPING AND WILL CUT POPS
FROM SUPERBLEND TO SMALL CHANCE. FOCUS THEN SHIFTS TO UPPER LOW
THAT WILL BE LIFTING OUT OF THE FOUR CORNERS ON SUNDAY. DOWNSTREAM
RIDGING RESULTING FROM THIS SYSTEM WILL HAVE OUR AREA DRY SUNDAY
AND MONDAY. MEDIUM RANGE MODELS OFFERING VARYING SOLNS HANDLING
UPPER LOW BUT AGREEMENT CAN BE FOUND WITH A SLOWER TREND FOR
BRINGING PRECIP BACK INTO THE AREA...AND THIS IS REFLECTED IN
SUPERBLEND POPS AS WELL WITH ONLY SLIGHT CHANCE UNTIL TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 649 AM EDT WED MAY 4 2016
AN UPPER LEVEL TROF WILL MOVE SOUTH ACROSS THE MIDWEST TODAY.
AHEAD OF THIS SYSTEM...A COLD FRONT WILL MOVE ACROSS NORTHERN
INDIANA AND BE ACCOMPANIED BY SHOWERS AND LOWER CEILINGS. VERY
LIMITED MID LEVEL INSTABILITY SHOULD LIMIT STORM DEVELOPMENT. HAVE
KEPT THUNDER OUT OF TAFS FOR NOW...ALTHOUGH AN ISOLATED STORM IS
POSSIBLE. AN UPPER LEVEL LOW WILL DRIFT SOUTH OVER THE AREA LATER
TODAY BEHIND THE FRONT AND SHOULD KEEP CONDITIONS IFR OR LOW
MVFR/CIGS 008 TO 012.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT THURSDAY FOR LMZ043-
046.
GALE WARNING UNTIL 5 AM EDT THURSDAY FOR LMZ043-046.
&&
$$
UPDATE...AGD
SYNOPSIS...SKIPPER/AGD
SHORT TERM...JAL
LONG TERM...JAL
AVIATION...SKIPPER
VISIT US AT WWW.WEATHER.GOV/IWX
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
617 PM CDT THU MAY 5 2016
...AVIATION UPDATE...
.SYNOPSIS...
ISSUED AT 315 PM CDT THU MAY 5 2016
HIGH PRESSURE RIDGE OVER THE CWA PROVIDING FULL SUNSHINE...LIGHT
WINDS AND PLEASANT SPRING TEMPERATURES. 2 PM READINGS WERE IN THE
UPPER 50S TO LOWER 60S. WEAK CONVERGENCE IN THE MID LEVELS HAS
CAUSED A BAND OF MID LEVEL CLOUDS MUCH OF THE DAY FROM EASTERN MN
INTO CENTRAL IA AND NORTH CENTRAL MO. THIS HAS PRETTY MUCH STAYED
JUST WEST OF THE DVN CWA AS THE CLOUDS DRIFT SOUTHWARD. THERE HAS
EVEN BEEN A FEW LIGHT SHOWERS REACHING THE GROUND IN FAR WESTERN
WI AND THE EAST METRO OF THE TWIN CITIES. THESE SHOWERS WERE
OCCURRING IN THE STRONGER ZONE OF WARM AIR ADVECTION.
ELSEWHERE...TEMPERATURES WERE IN THE UPPER 70S TO MID 80S IN THE
GREAT PLAINS...WITH SOME LOWER 90S IN ND AND MANITOBA. RELATIVE
HUMIDITY THERE WAS 15 PERCENT WITH SOUTHWEST WINDS GUSTING OVER 30
MPH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 315 PM CDT THU MAY 5 2016
MUCH WARMER TEMPERATURES IN THE SHORT TERM.
TONIGHT...HIGH PRESSURE RIDGE WILL BE PUSHING SOUTH OF THE AREA
ALLOWING FOR WARMER TEMPERATURES AS WINDS BECOMING LIGHT SOUTHWEST.
LOWS WILL BE ABOUT 10 DEGREES WARMER THAN LAST NIGHT...IN THE UPPER
40S. SCATTERED MID LEVEL CLOUDS SHOULD DEVELOP OVERNIGHT BUT EXPECTING
ANY SHOWERS TO REMAIN IN WISCONSIN WHERE THE BETTER WARM AIR ADVECTION
WILL EXIST. BELIEVE THE HRRR IS OVERDOING THE SHOWERS IN THE DVN CWA
BUT CAN`T RULE OUT A COUPLE OF SPRINKLES. WON`T MENTION IN THE GRIDS
BUT SOMETHING FOR LATER SHIFTS TO MONITOR.
FRIDAY...WARM DAY WITH THE RETURN FLOW AROUND THE HIGH PRESSURE
SYSTEM DROPPING INTO THE LOWER MS VALLEY. A WEST TO SOUTHWEST
WIND...850 MB TEMPERATURES OF +15 TO 16C AND A DRY AIRMASS SHOULD
SUPPORT LOWER 80S AT MOST LOCATIONS. IT IS POSSIBLE A FEW SPOTS
MAY MANAGE TO SEE 85 DEGREES CONSIDERING WE SHOULD HAVE SUNNY SKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 315 PM CDT THU MAY 5 2016
SATURDAY...EASTWARD PROGRESSION OF THE 500MB RIDGE AXIS WILL BE
HALTED BY A SHORTWAVE TROUGH DIVING SOUTHEASTWARD THROUGH THE UPPER
MIDWEST AND GREAT LAKES. SIGNIFICANT HEIGHT FALLS ASSOCIATED WITH
THIS SYSTEM ARE FORECAST TO REMAIN OVER WISCONSIN AND MICHIGAN AND
POINTS TO THE E/NE. AS A RESULT...LIFT OVER E IOWA/W ILLINOIS WILL
BE WEAK AND PRIMARILY RESTRICTED TO LOW-LEVEL CONVERGENCE ALONG A
SOUTHWARD MOVING COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ALONG AND SLIGHTLY AHEAD OF THE
FRONT...POPS ARE IN THE 30-40 PERCENT RANGE WITH RAIN AMOUNTS LESS
THAN A TENTH FOR MOST AREAS. THE FRONT IS FORECAST TO REACH THE
SOUTHERN CWA BY THE MID TO LATE AFTN.
THUNDERSTORM DETAILS...THE BEST CHANCES FOR A FEW STRONG STORMS IN
THE DVN CWA ARE IN THE COUNTIES ALONG AND SOUTH OF HIGHWAY 34...TO
THE WEST OF GALESBURG...WHERE MUCAPES MAY EXCEED 1500 J/KG AND 0-6
KM BULK SHEAR IS NEAR 45 KTS OR SLIGHTLY HIGHER.
SUNDAY THROUGH TUESDAY...SATURDAY/S COLD FRONT WILL BECOME QUASI-
STATIONARY SATURDAY NIGHT AND RETURN AS A WARM FRONT SUNDAY AND
MONDAY AS IT IS FORCED BY A NEW AREA OF LOW PRESSURE FORMING IN THE
WEST-CENTRAL PLAINS. SHOWER AND THUNDERSTORM CHANCES ARE HIGHEST
FROM SUNDAY NIGHT INTO TUESDAY. GFS 850MB WV TRANSPORT IS MAXIMIZED
ON MONDAY AND MONDAY NIGHT AS PWATS INCREASE TO 1.25 INCHES TO THE
ESE OF A COHERENT 850MB LOW MOVING INTO E NEBRASKA.
RAIN POTENTIAL...THE THREAT FOR WIDESPREAD HEAVY RAIN WITH THIS LOW
PRESSURE SYSTEM HIGHLIGHTED IN THE CPC 3-7 DAY HAZARDOUS WEATHER
OUTLOOK HAS NOW SHIFTED FURTHER TO THE EAST TO INCLUDE THE ENTIRE
FORECAST AREA. WHILE PWATS ARE NOT FORECAST TO BECOME ANOMALOUSLY
HIGH...REMAINING BELOW 1 STANDARD DEVIATION...THE SYSTEM IS A SLOW
MOVER AND SHOWS A SOLID MOISTURE CONNECTION WITH THE WESTERN GULF OF
MEXICO...VIA 850 WV TRANSPORT VECTORS.
THE WPC 5-7 DAY QPF SUPPORTS CPC/S OUTLOOK...PAINTING A GENERAL 1 TO
3 INCHES ALONG WHERE THE WARM FRONT SETS UP AND THE 850MB LOW
TRACKS...FROM EASTERN NEBRASKA THROUGH IOWA AND NORTHERN
MISSOURI INTO ILLINOIS AND SOUTHERN WISCONSIN.
THUNDERSTORM POTENTIAL...TOO EARLY TO FORECAST WITH MUCH DETAIL.
HOWEVER...SOME STRONG OR SEVERE STORMS ARE POSSIBLE ON MONDAY OVER
THE SOUTHWEST SECTION OF THE FORECAST AREA.
WIDESPREAD CLOUDS AND THE THREAT FOR RAIN TRANSLATES INTO NO BIG
WARM UPS WITH AVG HIGH TEMPS IN THE LOWER 70S.
WEDNESDAY...SEASONAL TEMPS CONTINUE WITH SLIGHT CHANCES FOR SHOWERS
OR AN ISOLATED STORM. UTTECH
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 615 PM CDT THU MAY 5 2016
HIGH PRESSURE WILL BRING A VERY CLEAR CALM AND VFR NIGHT TO THE
REGION TONIGHT...FOLLOWED BY A VFR DAY OF CLEAR/HIGH CLOUDS
FRIDAY. WINDS WILL BE LIGHT WEST TO NORTHWEST OVERNIGHT...FOLLOWED
BY A TURN TO SOUTHWEST TO WEST FRIDAY AROUND 10-15 KTS THROUGH THE
DAYTIME HOURS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...UTTECH
AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS WICHITA KS
651 PM CDT THU MAY 5 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 240 PM CDT THU MAY 5 2016
MAIN FORECAST HIGHLIGHT IS SEVERE THUNDERSTORM POTENTIAL
SATURDAY-MONDAY...BUT ESPECIALLY SUNDAY AFTERNOON-EVENING.
A HIGH AMPLITUDE SHORTWAVE RIDGE PROGRESSING OVER MID-AMERICA
WILL SUPPORT CONTINUED TRANQUIL WEATHER THROUGH FRIDAY
NIGHT/SATURDAY. INCREASING SOUTHERLY LOW-LEVEL WINDS IN RESPONSE
TO AN APPROACHING DEEP WESTERN CONUS TROUGH ALONG WITH THE
INCREASING ATMOSPHERIC THICKNESS WILL HELP BOOST DAYTIME HIGH
TEMPERATURES WELL INTO THE 80S FRIDAY AND SATURDAY.
ISOLATED TO WIDELY SCATTERED THUNDERSTORM CHANCES SHOULD INCREASE
MAINLY WEST AND NORTH OF THE FORECAST AREA SATURDAY
AFTERNOON/EVENING. THE 1ST OF A COUPLE SHORTWAVES IS EXPECTED TO
EJECT NORTHEAST OUT OF THE BASE OF THE WESTERN CONUS TROUGH BY
AFTERNOON...DEEPENING THE SURFACE LOW AND SHARPENING A DRYLINE
ACROSS THE HIGH PLAINS. MEANWHILE...A COLD FRONT WILL PROGRESS
SOUTH ACROSS THE CENTRAL PLAINS IN RESPONSE TO ENERGY DROPPING
SOUTHEAST OVER THE GREAT LAKES...WITH THE FRONT LIKELY STALLING
OVER FAR NORTHERN KS/SOUTHERN NE BY AFTERNOON. MOISTURE RETURN
WILL BE MARGINAL ACROSS THE WARM SECTOR...STUNTED BY PERSISTENT
LOW-LEVEL HIGH PRESSURE ACROSS THE NORTHERN GULF OF MEXICO.
HOWEVER...THINKING BOUNDARY LAYER DEWPOINTS REACHING THE 50S ARE
REASONABLE...YIELDING MLCAPE VALUES AROUND 1500 J/KG...AND DEEP
LAYER SHEAR AROUND 50 KTS SUPPORTING SUPERCELLS. THINKING STORM
INITIATION IS MOST LIKELY NEAR THE TRIPLE POINT IN THE VICINITY OF
NORTHWEST AND POSSIBLY WESTERN KS...WITH THIS ACTIVITY PROBABLY
CONGEALING INTO A COMPLEX OR TWO AS IT PROGRESSES EAST/SOUTHEAST
ALONG AND NORTH OF THE STALLED BOUNDARY OVER NORTHERN...CENTRAL
AND EAST-CENTRAL KS. HOWEVER...SEVERE THREAT SHOULD TEND TO WANE
WITH EASTERN EXTENT AS INSTABILITY DROPS OFF.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 240 PM CDT THU MAY 5 2016
MEDIUM RANGE CONSENSUS SUGGESTS THE 2ND IN A SERIES OF SHORTWAVES
WILL EJECT NORTHEAST ONTO THE PLAINS SUNDAY. GFS/ECMWF SUGGEST
DRYLINE SHOULD MIX A BIT FURTHER EAST WITH THIS SECOND SYSTEM
(ALTHOUGH NAM IS QUITE A BIT FURTHEST WEST)...WITH BOUNDARY LAYER
DEWPOINTS LIKELY INCREASING TO AT LEAST NEAR 60F BY PEAK HEATING
SUNDAY. WOULDN`T BE SURPRISED IF GFS/ECMWF COME INTO BETTER
AGREEMENT WITH THE SLOWER/FURTHER WEST NAM. THE ASSOCIATED
INCREASED INSTABILITY ALONG WITH CONTINUED NEAR 50 KTS OF DEEP
LAYER SHEAR WILL SUPPORT SEVERE STORMS...WITH INITIATION PROBABLY
SOMEWHERE WEST/SOUTHWEST OF I-135/35 CORRIDOR SUNDAY AFTERNOON.
DETAILS ON TIMING AND PLACEMENT OF VARIOUS FEATURES AND
ORIENTATION AND MAGNITUDE OF SHEAR VALUES...ALONG WITH LOW-LEVEL
MOISTURE QUALITY REMAIN IN QUESTION...BUT OVERALL PATTERN SUGGESTS
DECENT POTENTIAL FOR SEVERE STORMS INCLUDING SUPERCELLS ACROSS THE
CENTRAL/SOUTHERN PLAINS SUNDAY AFTERNOON-EVENING. AS THINGS
CURRENTLY STAND...THINKING HIGHEST PROBABILITY WILL BE GENERALLY
ALONG/WEST OF THE FLINT HILLS...WITH MAIN THREATS LARGE
HAIL...DAMAGING WINDS AND AN ISOLATED TORNADO OR TWO. HOWEVER...IF
LOW-LEVEL MOISTURE QUALITY INCREASES...TORNADO THREAT WILL
INCREASE AS WELL. STAY TUNED.
THE MAIN UPPER LOW WILL FINALLY EJECT NORTHEAST ONTO THE PLAINS
MONDAY...PUSHING THE WARM SECTOR MAINLY EAST OF THE
AREA...ALTHOUGH FAR EASTERN/SOUTHEAST KS MAY STILL BE UNDER THE
GUN FOR SEVERE STORMS MONDAY AFTERNOON/EVENING. MODEL CONSENSUS
SUGGESTS NEXT CHANCE FOR STORMS COULD ARRIVE FOR MAINLY FAR
EASTERN/SOUTHEAST KS WEDNESDAY-THURSDAY...ALTHOUGH UNCERTAINTY
REMAINS HIGH BETWEEN THE GFS/ECMWF SOLUTIONS AND ENSEMBLES
REGARDING LARGE SCALE PATTERN EVOLUTION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 650 PM CDT THU MAY 5 2016
ALL AREAS WL RMN VFR THRU FRI NGT & LKLY BYD WITH CLDS AT OR ABOVE
13,000FT. WINDS THAT ARE E-SE <10KTS OVERNGT WL BECOME DUE SLY FRI
MRNG & INCR 14-17Z W/ GREATEST INCR IN CNTRL & SC KS WHERE 22-26KT
GUSTS (25-30MPH) ARE LKLY FROM 18Z ONWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 51 84 60 85 / 0 0 0 10
HUTCHINSON 51 85 61 85 / 0 0 0 10
NEWTON 51 84 60 84 / 0 0 0 10
ELDORADO 51 83 60 83 / 0 0 0 10
WINFIELD-KWLD 51 83 60 85 / 0 0 0 0
RUSSELL 53 86 60 84 / 0 0 10 20
GREAT BEND 53 87 61 84 / 0 0 0 20
SALINA 50 84 60 85 / 0 0 0 10
MCPHERSON 50 85 61 85 / 0 0 0 10
COFFEYVILLE 49 81 58 83 / 0 0 0 0
CHANUTE 48 81 58 83 / 0 0 0 0
IOLA 48 81 58 83 / 0 0 0 0
PARSONS-KPPF 48 81 58 83 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ADK
LONG TERM...ADK
AVIATION...EPS
[top]
Area Forecast Discussion
National Weather Service Dodge City KS
610 PM CDT THU MAY 5 2016
...UPDATE TO AVIATION...
.SHORT TERM...(This evening through Friday)
Issued at 142 PM CDT Thu May 5 2016
Temperatures were rising faster than the forecast T curve early
this morning, and a change to the Experimental HRRR appears to
have captures the temperature forecast a little better in the
midday. It may be a couple of degrees overdone as it is warmer
than all the other guidance/blends, however with it being early
May now the warming can last later in the day. The forecast high
was generally bumped about 3 degrees over the area. The surface
high will continue to give way to gradual troughing over eastern
Colorado and the extreme western counties overnight. Much more
breezy conditions to marginally windy conditions can be expected
Friday.
.LONG TERM...(Friday night through Thursday)
Issued at 142 PM CDT Thu May 5 2016
Continued focus exists on the weekend for severe weather
potential. Saturday and Sunday present somewhat different pattern
recognition setups with marginal shear on Saturday, increasing by
Sunday as the upper jet advances into the central High Plains.
CAPES appear moderate on Saturday, and a few hail and wind
producing severe storms could develop near the dryline in this
marginal shear environment. The ECMWF is the model that pushes the
dryline almost out of our forecast area on Sunday afternoon
before convection initiation, while the GFS was far more emphatic
with convection occurring farther west. Many characteristics of
the mesoscale are as of yet unknown, however thunderstorms are
probable this weekend. The best chance for the most widespread
severe and especially tornadic threat would be more likely farther
north where the models are in agreement with placement of the warm
front.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 607 PM CDT Thu May 5 2016
VFR conditions will prevail at all TAF sites through early Friday
afternoon. Southeast winds 5 to 15kt will persist tonight as surface
high pressure in eastern Kansas and Missouri drops southward into
the Ark-La-Tex Region. Winds will become more southerly mid to
late Friday morning while increasing to around 20 to 30kt as a lee
side trough of low pressure strengthens across eastern Colorado.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 54 86 59 84 / 0 0 10 30
GCK 54 88 57 83 / 0 10 10 30
EHA 51 85 55 82 / 0 10 10 20
LBL 53 87 57 85 / 0 0 10 20
HYS 52 87 60 82 / 0 10 10 50
P28 54 86 60 84 / 0 0 10 20
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...JJohnson
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1007 PM EDT THU MAY 5 2016
.UPDATE...
ISSUED AT 1007 PM EDT THU MAY 5 2016
RECENT RADAR TRENDS INDICATE THAT THE RAIN SHOWERS WILL CONTINUE
TO EXPERIENCE OVERNIGHT WILL NOT SPREAD QUITE AS FAR WESTWARD...OR
BE QUITE AS WIDESPREAD...AS PREVIOUSLY FORECAST. THEREFORE...THE
HOURLY FORECAST GRIDS THROUGH 12Z FRIDAY HAVE BEEN UPDATED TO
REFLECT THESE LATEST TRENDS. AN UPDATED ZONE FORECAST TEXT
PRODUCT HAS BEEN ISSUED AS WELL. THE REST OF THE FORECAST IS IN
GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM EDT THU MAY 5 2016
WV SAT AND HRRR HAS SUGGESTED THAT THE UPPER LEVEL CLOSED LOW HAS
PROGRESSED SOUTHEAST INTO WESTERN NC AND NW SC. OVERALL THE MESO
MODELS AND MORE SYNOPTIC MODELS HAVE HAD A DECENT HANDLE ON THIS
PROGRESSION. WE CONTINUE TO HAVE SOME SHOWERS THAT HAVE DEVELOPED
ACROSS THE SOUTH AND SW PORTIONS OF THE CWA. THIS HAS BEEN DUE TO
THE STEEPER LOW LEVEL LAPSE RATES...AS WE HAVE SEEN BREAKS IN THE
CLOUDS. THESE LAPSE RATES ARE COMBINING WITH THE ALREADY
REASONABLY STEEP MID LEVEL LAPSE RATES. OVERALL COVERAGE HAS BEEN
SCATTERED WITH BETTER COVERAGE TO THE SOUTH AND EAST. RIGHT NOW
MODELS DO WANT TO BRING ADDITIONAL SHOWERS IN THE FAR EAST THIS
EVENING AND TONIGHT...HOWEVER BIGGEST QUESTION WOULD BE HOW MUCH
COVERAGE DO WE SEE. RIGHT NOW OPTED TO LOWER POPS GIVEN SOME OF
THE UNCERTAINTY. THIS UNCERTAINTY COMES WHEN LOOKING UPSTREAM
RADAR COVERAGE IS QUITE LOW COMPARED TO WHAT MAY HAVE BEEN
PREVIOUSLY THOUGHT AND CAMS ARE NOT HITTING IT TOO HARD EITHER.
THE OTHER QUESTION WOULD BE HOW MUCH CLOUD COVER DO WE SEE
TONIGHT...RIGHT NOW KEEP CLOUD COVER HIGHER IN THE EAST GIVEN THE
BETTER SHOWER COVERAGE. ALSO COULD HAVE IMPLICATIONS ON TEMPS AND
FOG POTENTIAL. RIGHT NOW WILL ADD SOME PATCHY DEEPER VALLEY FOG
AND JUST MINOR TEMP SPLIT GIVEN THE CLOUD UNCERTAINTY.
THIS UPPER LOW IS FAIRLY SLOW TO MOVE EAST...AS A OMEGA BLOCK
PATTERN SETS UP ACROSS THE CENTRAL PART OF THE CONUS. THEREFORE
SURFACE HIGH PRESSURE WILL BE SLOW TO BUILD NORTHEAST FROM THE
GULF. THAT SAID THERE WAS A NEED FOR SHOWERS IN THE FAR EAST AND
SOUTHEAST FOR FRIDAY GIVEN THE SLOW PROGRESS OF VERTICALLY STACKED
LOW AND CONTINUED PVA/SHORTWAVES DIVING SOUTH. NOW FRIDAY NIGHT
HEIGHTS WILL CONTINUE TO RISE AS UPPER LOW/OMEGA BLOCK BREAK DOWN
AND PROGRESS EAST. THERE IS A WEAK SURFACE TROUGH OR WAVE MAY
BRING SOME SLIGHT CHANCE SHOWERS TO THE FAR NORTH OVERNIGHT.
OTHERWISE MOST SPOTS SHOULD DRY OUT AT THIS POINT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 353 PM EDT THU MAY 5 2016
MODELS ARE IN REASONABLY GOOD AGREEMENT WITH AN OMEGA BLOCK PATTERN
DEAMPLIFYING OVER THE WEEKEND AND EVOLVING TO MORE OR LESS A SPLIT
FLOW PATTERN NEXT WEEK. THE CURRENT UPPER LEVEL SYSTEM MEANDERING OF
THE APPALACHIANS AND THE SOUTHEAST IS EXPECTED TO SHIFT OFF THE
EASTERN SEABOARD. AT THE SAME TIME...AN UPPER LEVEL LOW WILL MOVE
FROM THE HUDSON AND JAMES BAY REGION INTO ONTARIO AND QUEBEC AND
THEN INTO THE CANADIAN OVER THE WEEKEND AND INTO EARLY NEXT WEEK. A
SHORTWAVE TROUGH IS EXPECTED TO MOVE THROUGH THE GREAT LAKES REGION
EARLY IN THE PERIOD AND INTO THE NORTHEASTERN CONUS BY THE END OF
THE WEEKEND. THIS WILL SEND A COLD FRONT INTO THE OHIO VALLEY AND
APPALACHIAN REGION FROM LATE SATURDAY INTO SATURDAY NIGHT...WITH THE
BOUNDARY STALLING OUT LATE IN THE WEEKEND ACROSS THE OHIO OR
TENNESSEE VALLEY. THE MODEL CONSENSUS IS FOR A SMALL CHANCE OF
CONVECTION ON ISENTROPIC LIFT EARLY IN THE PERIOD ON SATURDAY. A
LULL IN ACTIVITY IS POSSIBLE FROM MIDDAY INTO THE AFTERNOON ON
SATURDAY...WITH MORE ORGANIZED CONVECTION LIKELY SATURDAY EVENING
INTO SATURDAY NIGHT. CHANCES FOR CONVECTION APPEAR TO LESSEN ON
SUNDAY AS THE SHORTWAVE TROUGH DEPARTS TO THE EAST AND NORTHEAST.
AN AREA OF SFC LOW PRESSURE MEANWHILE WILL BEGIN TO DEVELOP OVER THE
WEEKEND IN THE LEE OF THE ROCKIES AHEAD OF THE SECOND UPPER LEVEL
LOW MEANDERING FROM THE SOUTHWESTERN CONUS INTO THE ROCKIES OVER THE
WEEKEND AND EVENTUALLY EJECTING INTO THE PLAINS. IN RESPONSE TO THE
DEVELOPING LOW AND HEIGHT RISES OVER THE SOUTHEASTERN CONUS...THE
STATIONARY FRONT SHOULD RETURN NORTH AS A WARM FRONT MONDAY INTO
MONDAY NIGHT. EVEN AS THE REGION GETS INTO THE WARM SECTOR
CONVECTION CANNOT BE RULED OUT AT ANY POINT ON MONDAY. THE SFC LOW
PRESSURE SYSTEM SHOULD GRADUALLY TRACK FROM THE PLAINS TOWARD THE
GREAT LAKES REGION AT MIDWEEK AND THEN EVENTUALLY INTO THE
NORTHEASTERN CONUS. MODEL AGREEMENT FROM RUN TO RUN AND MODEL TO
MODEL IN THESE DETAILS DIMINISHES GREATLY BY TUESDAY AND TUESDAY
NIGHT AND ALSO CONFIDENCE IN ANY DETAILS. HOWEVER...THE OVERALL
MODEL BLEND AND CONSENSUS APPEARS TO BE FOR ANOTHER PEAK IN
CONVECTION CHANCES FROM LATE MONDAY NIGHT OR TUESDAY INTO THE DAY ON
WEDNESDAY AS SEVERAL SHORTWAVES SHOULD MOVE THROUGH THE OHIO VALLEY
AND GREAT LAKES REGION. LOCALLY HEAVY RAIN COULD BECOME A CONCERN
IN LOCATIONS THAT EXPERIENCE MULTIPLE ROUNDS OF CONVECTION.
TEMPERATURES SHOULD AVERAGE ABOVE NORMAL IN THE WARM SECTOR TO START
THE PERIOD...ALTHOUGH TEMPERATURES SHOULD BE SUPPRESSED ON SUNDAY
AND SUNDAY NIGHT WITH THE FRONT ACROSS THE AREA AND ABUNDANT CLOUD
COVER ANTICIPATED. THEREAFTER...TEMPERATURES SHOULD AVERAGE A BIT
ABOVE NORMAL THROUGH THE REST OF THE PERIOD...WITH HIGHS IN THE MID
70S TO AROUND 80 AND LOWS IN THE UPPER 50S TO AROUND 60.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 800 PM EDT THU MAY 5 2016
EXPECTING CONDITIONS AT THE TAF SITES TO FLUCTUATE BETWEEN VFR
AND MVFR TONIGHT INTO EARLY TOMORROW MORNING...DUE TO LOW CLOUDS
AND SCATTERED RAIN SHOWERS. THE RAIN SHOULD AFFECT PRIMARILY
SJS...SYM...AND JKL THROUGH LATE TONIGHT. THE RAIN IS ASSOCIATED
WITH AN AREA OF LOW PRESSURE ALOFT THAT IS ROTATING ACROSS THE
REGION. LATER TONIGHT...6-12Z TO BE EXACT...THERE SHOULD BE ENOUGH
BREAKS IN THE CLOUDS TO ALLOW FOR SOME FOG TO FORM. THE FOG WILL
BE MOST WIDESPREAD AND DENSE IN THE VALLEYS AND NEAR LARGE BODIES
OF WATER. SME AND LOZ MAY SEE SOME FOG AS WELL BETWEEN 9 AND 12Z
FRIDAY. THE FOG SHOULD BE GONE BY 13Z. CLOUD BASES SHOULD GO TO
VFR AND STAY THERE THROUGH OUT THE DAY ON FRIDAY. ISOLATED TO
SCATTERED RAIN SHOWERS WILL AGAIN BE POSSIBLE IN OUR FAR EAST ON
FRIDAY. SCATTERED TO BROKEN LOW TO MID LEVEL CLOUD COVER WILL ALSO
BE PRESENT. WINDS SHOULD BE OUT OF THE NORTH TO NORTHWEST AT 5 TO
10KTS WITH SOME GUSTS POSSIBLE ON FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AR
SHORT TERM...DJ
LONG TERM...JP
AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
800 PM EDT THU MAY 5 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM EDT THU MAY 5 2016
WV SAT AND HRRR HAS SUGGESTED THAT THE UPPER LEVEL CLOSED LOW HAS
PROGRESSED SOUTHEAST INTO WESTERN NC AND NW SC. OVERALL THE MESO
MODELS AND MORE SYNOPTIC MODELS HAVE HAD A DECENT HANDLE ON THIS
PROGRESSION. WE CONTINUE TO HAVE SOME SHOWERS THAT HAVE DEVELOPED
ACROSS THE SOUTH AND SW PORTIONS OF THE CWA. THIS HAS BEEN DUE TO
THE STEEPER LOW LEVEL LAPSE RATES...AS WE HAVE SEEN BREAKS IN THE
CLOUDS. THESE LAPSE RATES ARE COMBINING WITH THE ALREADY
REASONABLY STEEP MID LEVEL LAPSE RATES. OVERALL COVERAGE HAS BEEN
SCATTERED WITH BETTER COVERAGE TO THE SOUTH AND EAST. RIGHT NOW
MODELS DO WANT TO BRING ADDITIONAL SHOWERS IN THE FAR EAST THIS
EVENING AND TONIGHT...HOWEVER BIGGEST QUESTION WOULD BE HOW MUCH
COVERAGE DO WE SEE. RIGHT NOW OPTED TO LOWER POPS GIVEN SOME OF
THE UNCERTAINTY. THIS UNCERTAINTY COMES WHEN LOOKING UPSTREAM
RADAR COVERAGE IS QUITE LOW COMPARED TO WHAT MAY HAVE BEEN
PREVIOUSLY THOUGHT AND CAMS ARE NOT HITTING IT TOO HARD EITHER.
THE OTHER QUESTION WOULD BE HOW MUCH CLOUD COVER DO WE SEE
TONIGHT...RIGHT NOW KEEP CLOUD COVER HIGHER IN THE EAST GIVEN THE
BETTER SHOWER COVERAGE. ALSO COULD HAVE IMPLICATIONS ON TEMPS AND
FOG POTENTIAL. RIGHT NOW WILL ADD SOME PATCHY DEEPER VALLEY FOG
AND JUST MINOR TEMP SPLIT GIVEN THE CLOUD UNCERTAINTY.
THIS UPPER LOW IS FAIRLY SLOW TO MOVE EAST...AS A OMEGA BLOCK
PATTERN SETS UP ACROSS THE CENTRAL PART OF THE CONUS. THEREFORE
SURFACE HIGH PRESSURE WILL BE SLOW TO BUILD NORTHEAST FROM THE
GULF. THAT SAID THERE WAS A NEED FOR SHOWERS IN THE FAR EAST AND
SOUTHEAST FOR FRIDAY GIVEN THE SLOW PROGRESS OF VERTICALLY STACKED
LOW AND CONTINUED PVA/SHORTWAVES DIVING SOUTH. NOW FRIDAY NIGHT
HEIGHTS WILL CONTINUE TO RISE AS UPPER LOW/OMEGA BLOCK BREAK DOWN
AND PROGRESS EAST. THERE IS A WEAK SURFACE TROUGH OR WAVE MAY
BRING SOME SLIGHT CHANCE SHOWERS TO THE FAR NORTH OVERNIGHT.
OTHERWISE MOST SPOTS SHOULD DRY OUT AT THIS POINT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 353 PM EDT THU MAY 5 2016
MODELS ARE IN REASONABLY GOOD AGREEMENT WITH AN OMEGA BLOCK PATTERN
DEAMPLIFYING OVER THE WEEKEND AND EVOLVING TO MORE OR LESS A SPLIT
FLOW PATTERN NEXT WEEK. THE CURRENT UPPER LEVEL SYSTEM MEANDERING OF
THE APPALACHIANS AND THE SOUTHEAST IS EXPECTED TO SHIFT OFF THE
EASTERN SEABOARD. AT THE SAME TIME...AN UPPER LEVEL LOW WILL MOVE
FROM THE HUDSON AND JAMES BAY REGION INTO ONTARIO AND QUEBEC AND
THEN INTO THE CANADIAN OVER THE WEEKEND AND INTO EARLY NEXT WEEK. A
SHORTWAVE TROUGH IS EXPECTED TO MOVE THROUGH THE GREAT LAKES REGION
EARLY IN THE PERIOD AND INTO THE NORTHEASTERN CONUS BY THE END OF
THE WEEKEND. THIS WILL SEND A COLD FRONT INTO THE OHIO VALLEY AND
APPALACHIAN REGION FROM LATE SATURDAY INTO SATURDAY NIGHT...WITH THE
BOUNDARY STALLING OUT LATE IN THE WEEKEND ACROSS THE OHIO OR
TENNESSEE VALLEY. THE MODEL CONSENSUS IS FOR A SMALL CHANCE OF
CONVECTION ON ISENTROPIC LIFT EARLY IN THE PERIOD ON SATURDAY. A
LULL IN ACTIVITY IS POSSIBLE FROM MIDDAY INTO THE AFTERNOON ON
SATURDAY...WITH MORE ORGANIZED CONVECTION LIKELY SATURDAY EVENING
INTO SATURDAY NIGHT. CHANCES FOR CONVECTION APPEAR TO LESSEN ON
SUNDAY AS THE SHORTWAVE TROUGH DEPARTS TO THE EAST AND NORTHEAST.
AN AREA OF SFC LOW PRESSURE MEANWHILE WILL BEGIN TO DEVELOP OVER THE
WEEKEND IN THE LEE OF THE ROCKIES AHEAD OF THE SECOND UPPER LEVEL
LOW MEANDERING FROM THE SOUTHWESTERN CONUS INTO THE ROCKIES OVER THE
WEEKEND AND EVENTUALLY EJECTING INTO THE PLAINS. IN RESPONSE TO THE
DEVELOPING LOW AND HEIGHT RISES OVER THE SOUTHEASTERN CONUS...THE
STATIONARY FRONT SHOULD RETURN NORTH AS A WARM FRONT MONDAY INTO
MONDAY NIGHT. EVEN AS THE REGION GETS INTO THE WARM SECTOR
CONVECTION CANNOT BE RULED OUT AT ANY POINT ON MONDAY. THE SFC LOW
PRESSURE SYSTEM SHOULD GRADUALLY TRACK FROM THE PLAINS TOWARD THE
GREAT LAKES REGION AT MIDWEEK AND THEN EVENTUALLY INTO THE
NORTHEASTERN CONUS. MODEL AGREEMENT FROM RUN TO RUN AND MODEL TO
MODEL IN THESE DETAILS DIMINISHES GREATLY BY TUESDAY AND TUESDAY
NIGHT AND ALSO CONFIDENCE IN ANY DETAILS. HOWEVER...THE OVERALL
MODEL BLEND AND CONSENSUS APPEARS TO BE FOR ANOTHER PEAK IN
CONVECTION CHANCES FROM LATE MONDAY NIGHT OR TUESDAY INTO THE DAY ON
WEDNESDAY AS SEVERAL SHORTWAVES SHOULD MOVE THROUGH THE OHIO VALLEY
AND GREAT LAKES REGION. LOCALLY HEAVY RAIN COULD BECOME A CONCERN
IN LOCATIONS THAT EXPERIENCE MULTIPLE ROUNDS OF CONVECTION.
TEMPERATURES SHOULD AVERAGE ABOVE NORMAL IN THE WARM SECTOR TO START
THE PERIOD...ALTHOUGH TEMPERATURES SHOULD BE SUPPRESSED ON SUNDAY
AND SUNDAY NIGHT WITH THE FRONT ACROSS THE AREA AND ABUNDANT CLOUD
COVER ANTICIPATED. THEREAFTER...TEMPERATURES SHOULD AVERAGE A BIT
ABOVE NORMAL THROUGH THE REST OF THE PERIOD...WITH HIGHS IN THE MID
70S TO AROUND 80 AND LOWS IN THE UPPER 50S TO AROUND 60.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 800 PM EDT THU MAY 5 2016
EXPECTING CONDITIONS AT THE TAF SITES TO FLUCTUATE BETWEEN VFR
AND MVFR TONIGHT INTO EARLY TOMORROW MORNING...DUE TO LOW CLOUDS
AND SCATTERED RAIN SHOWERS. THE RAIN SHOULD AFFECT PRIMARILY
SJS...SYM...AND JKL THROUGH LATE TONIGHT. THE RAIN IS ASSOCIATED
WITH AN AREA OF LOW PRESSURE ALOFT THAT IS ROTATING ACROSS THE
REGION. LATER TONIGHT...6-12Z TO BE EXACT...THERE SHOULD BE ENOUGH
BREAKS IN THE CLOUDS TO ALLOW FOR SOME FOG TO FORM. THE FOG WILL
BE MOST WIDESPREAD AND DENSE IN THE VALLEYS AND NEAR LARGE BODIES
OF WATER. SME AND LOZ MAY SEE SOME FOG AS WELL BETWEEN 9 AND 12Z
FRIDAY. THE FOG SHOULD BE GONE BY 13Z. CLOUD BASES SHOULD GO TO
VFR AND STAY THERE THROUGH OUT THE DAY ON FRIDAY. ISOLATED TO
SCATTERED RAIN SHOWERS WILL AGAIN BE POSSIBLE IN OUR FAR EAST ON
FRIDAY. SCATTERED TO BROKEN LOW TO MID LEVEL CLOUD COVER WILL ALSO
BE PRESENT. WINDS SHOULD BE OUT OF THE NORTH TO NORTHWEST AT 5 TO
10KTS WITH SOME GUSTS POSSIBLE ON FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DJ
LONG TERM...JP
AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
220 AM EDT WED MAY 4 2016
.UPDATE...
ISSUED AT 220 AM EDT WED MAY 4 2016
CLOUDS HOLDING TOUGH THIS MORNING...BUT WITH BASES AROUND
8KFT...NOT MUCH SHOWER ACTIVITY TO SPEAK OF. STILL A FEW SHOWERS
JUST NORTH OF I-64...ASSOCIATED WITH A LEFT OVER CONVERGENCE ZONE.
THIS ACTIVITY WILL CONTINUE TO SLIDE EAST INTO WEST VIRGINIA THIS
MORNING. MEANWHILE...VIGOROUS SHORTWAVE OVER THE NORTHERN
PLAINS/GREAT LAKES THIS MORNING IS MAKING ITS MOVE SOUTH WITH A
DECENT LINE OF SHOWERS AND THUNDERSTORMS ALONG THE SURFACE COLD
FRONT. HAVE SEEN SOME PERSISTENT WIND GUSTS UP TO 40-45 MPH.
FORTUNATELY...WITH THE FRONT BECOMING MORE NORTH/SOUTH ORIENTED BY
THE TIME IT GETS HERE...NOT ANTICIPATING THE WIND THREAT TO MAKE
IT INTO OUR AREA TODAY. HOWEVER...AS MENTIONED
PREVIOUSLY...CONDITIONS STILL FAVORABLE FOR SOME SMALL HAIL WITH
ANY THUNDERSTORMS THAT FORM WITH SUCH LOW FREEZING LEVELS. IN
FACT...ALREADY NUMEROUS REPORTS OF SMALL HAIL OVERNIGHT ACROSS
SOUTHERN WISCONSIN.
UPDATE ISSUED AT 1039 PM EDT TUE MAY 3 2016
PARTIAL CLEARING HAS ALLOWED FOR SOME TEMPERATURE DROP OFF IN
PLACES...HOWEVER MOSTLY CLOUDY SKIES LOOK TO MOVE BACK IN
OVERNIGHT...SO LOWS IN THE UPPER 40S STILL LOOK ON TARGET.
ISOLATED SHOWERS CONTINUE TO POP UP WITH THE APPROACH OF A SHORT
WAVE TROUGH...AND THE LATEST HRRR SHOWS AT LEAST WEAK RETURNS AT
TIMES THROUGH EARLY WEDNESDAY MORNING. HAVE UPDATED TEMPERATURES
AND DEW POINTS OVER THE NEXT SEVERAL HOURS TO ACCOUNT FOR THE
LATEST TRENDS...OTHERWISE THE FORECAST REMAINS ON TRACK. UPDATES
HAVE BEEN SENT.
UPDATE ISSUED AT 823 PM EDT TUE MAY 3 2016
THE FORECAST IS ON TRACK. A FEW SHOWERS ARE DOTTING PORTION OF THE
AREA...MAINLY NORTH OF I-64. THESE WILL CONTINUE TO THREATEN
THROUGH THE NIGHT AS A SHORT WAVE TROUGH MOVES THROUGH THE OHIO
VALLEY. FRESHENED UP THE HOURLY TEMPERATURES AND DEW POINTS TO
ALIGN BETTER WITH THE CURRENT TRENDS IN OBSERVATIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 402 PM EDT TUE MAY 3 2016
CURRENT CONDITIONS ACROSS THE AREA THIS AFTERNOON FEATURE SOME LOW
LEVEL MOISTURE HANGING AROUND THE APPALACHIAN REGION AS THE
BOUNDARY THAT HAD SPARKED SOME SIGNIFICANT CONVECTION OVER THE
AREA YESTERDAY HAS MOVED OFF TO THE EAST. SURFACE HIGH PRESSURE
WILL SLOWLY NUDGE IN FROM THE WEST. WITH STOUT LOW PRESSURE
EXITING THE AREA AND THE NEXT WAVE DIVING SOUTHEAST FROM THE GREAT
LAKES REGION...LINGERING CLOUD COVER WILL BUILD BACK INTO THE
AREA LATE TONIGHT.
WITH A FEW BREAKS TODAY IN THE CLOUD COVER...SOME ISOLATED SHOWERS
DID DEVELOP AND WILL SLOWLY DIMINISH HEADING INTO THE OVERNIGHT
HOURS IN THE SOUTH. AS A WEAK WAVE PASSES THE AREA TONIGHT A FEW
SHOWERS WILL POP UP AGAIN THE NORTH. THE CONTINUED CLOUD COVER
WILL KEEP THE DEVELOPMENT OF FOG UNLIKELY. HEADING INTO THE DAY
TOMORROW...A STRONG SHORT WAVE WILL SWING THROUGH THE OH VALLEY
BY THE AFTERNOON AND INTO THE EVENING. WITH A DECENT GRADIENT IN
THE FRONT MOVING THROUGH...WINDS WILL BE QUITE GUSTY WITH THE
FRONT...HOWEVER INSTABILITY WILL BE LACKING. WILL EXPECT SHOWERS
AND A FEW THUNDERSTORMS THROUGH THE AFTERNOON. WITH JUST ENOUGH
INSTABILITY AND FORCING FROM THE FRONT...SOME LOWER FREEZING
HEIGHTS WILL LEAD TO A FEW INSTANCES OF SMALL HAIL. A COLD CORE
LOW STALLING OVERHEAD INTO THE OVERNIGHT HOURS WILL LEAD TO COOLER
TEMPS OVERNIGHT WEDNESDAY NIGHT AND LINGERING CLOUD COVER. IN
FACT...TEMPS WILL DROP INTO THE LOWER 40S AND POSSIBLY SOME UPPER
30S. OVERALL...WITH THE EXCEPTION OF WEDNESDAY AFTERNOON...THE
PERIOD LOOKS TO BE CLOUDY...COOL...AND A FEW SHOWERS.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 303 PM EDT TUE MAY 3 2016
A DEEP CLOSED LOW WILL BE PASSING ACROSS KY TO START OFF THE
EXTENDED PERIOD...PULLING MUCH COOLER CANADIAN AIR DOWN INTO THE
REGION. THE LOW WILL SLOWLY SHIFT SOUTHEAST OF THE AREA THROUGH THE
DAY THURSDAY AND THURSDAY NIGHT...KEEPING STRONG N TO S FLOW ACROSS
MUCH OF THE REGION INTO THE DAY SATURDAY...WHILE THE LOW REMAINS
PARKED ALONG THE EASTERN SEABOARD.
AT THIS POINT...ANOTHER STRONG UPPER LEVEL LOW OVER HUDSON BAY IN
CANADA WILL BEGIN DROPPING SOUTHWARD. THE LOW TO OUR EAST WILL BEGIN
TO DISSOLVE AND MERGE INTO THE INCOMING LOW AS IT CONTINUES TO PUSH
SOUTHWARD SATURDAY INTO SUNDAY. WHILE THE UPPER LOW WILL STAY TO OUR
NE...EXPECT THE RETURN OF NW FLOW TO THE REGION DURING THIS TIME
FRAME. THE LOW WILL THEN START SHIFTING EASTWARD...WITH UPPER LEVEL
RIDGING TAKING HOLD THROUGH THE DAY MONDAY.
LINGERING PRECIP IS EXPECTED THROUGH THE DAY THURSDAY AND EVEN INTO
THURSDAY NIGHT...MAINLY IN THE SE ALONG THE HIGHER TERRAIN DUE TO
LINGERING MOISTURE AND NW TO SE UPSLOPE FLOW THROUGH THE DAY. SO
LONG AS THE UPPER LEVEL LOW AND SURFACE LOW STAY POSITIONED OVER THE
EASTERN COAST...THIS NW FLOW WILL BE IN PLACE. THE STRONG N TO S
FLOW ALOFT WILL ALSO PULL IN DEEP CAA...WITH HIGHS THURSDAY ONLY
REACHING THE LOW TO MID 50S. AS CONDITIONS BEGIN CLEARING THURSDAY
NIGHT...EXPECT TEMPS TO DROP OFF TO THE LOW TO MID 40S...WITH COLDEST
TEMPS LIKELY IN THE VALLEYS. FRIDAY WILL SHOW SOME IMPROVEMENT...BUT
HIGHS GENERALLY IN THE UPPER 60S IS STILL BELOW SEASONABLE NORMS FOR
THE BEGINNING OF MAY.
THE FLOW ALOFT WILL WEAKEN SATURDAY AS UPPER LEVEL RIDGING NUDGES
INTO THE CENTRAL PLAINS. SURFACE HIGH PRESSURE WILL KEEP CONDITIONS
MOSTLY CLEAR...AND TEMPERATURES WILL BE ALLOWED TO RISE INTO THE MID
AND UPPER 70S AS WINDS BECOME MORE WRLY NEAR THE SURFACE...TAPPING
INTO WARMER GULF FLOW COMING OUT OF TEXAS. THE NEXT UPPER LEVEL LOW
DROPPING DOWN FROM CANADA WILL PUSH A COLD FRONT SOUTHWARD...
ENTERING INTO THE OHIO VALLEY SATURDAY NIGHT...BECOMING NEARLY
STATIONARY ACROSS THE STATE DURING THE DAY SUNDAY. WHILE MOST OF THE
MOISTURE WILL BE CONTAINED CLOSER TO THE UPPER LEVEL AND SURFACE LOW
TO OUR NE...STILL EXPECT SOME LOW END CHANCE POPS TO MAKE IT INTO
OUR CWA...MAINLY IN THE NORTHERN HALF...BEGINNING SATURDAY NIGHT AND
CONTINUING ALL THE WAY INTO MONDAY...DESPITE UPPER LEVEL RIDGING
TAKING HOLD. GENERALLY WRLY FLOW...EVEN ALOFT...AT THIS POINT...WILL
CONTINUE TO PULL IN WARMER TEMPS...TAPPING INTO THE GULF MOISTURE
ACROSS TX. THIS WILL KEEP TEMPS IN THE 70 DEGREE RANGE THROUGH THE
WEEKEND AND STARTING OUT THE NEXT WEEK AS WELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 220 AM EDT WED MAY 4 2016
VFR CONDITIONS LOOK TO HANG ON FOR MOST LOCATIONS THROUGH THE
NEXT 9 TO 12 HOURS. AN UPPER LEVEL DISTURBANCE WILL BRING SHOWERS
AND A FEW THUNDERSTORMS TO THE AREA AFTER 17Z TODAY. CEILINGS AND
VISIBILITIES WILL GRADUALLY LOWER TO MVFR THROUGH THE REST OF THE
PERIOD. WINDS WILL BE OUT OF THE WEST AND NORTHWEST...GENERALLY IN
BETWEEN 5 AND 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...SHALLENBERGER
LONG TERM...JMW
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1004 PM EDT THU MAY 5 2016
.SYNOPSIS...
LOW PRESSURE WILL MOVE UP FROM THE SOUTH TONIGHT AND MOVE ACROSS
NOVA SCOTIA FRIDAY MORNING. HIGH PRESSURE WILL BRIEFLY BUILD OVER
THE AREA FRIDAY AFTERNOON AS ANOTHER WEAK LOW REACHES THE MID
ATLANTIC COAST.
&&
.NEAR TERM /THROUGH FRIDAY/...
925 PM UPDATE: THE TREND OF HRLY HRRR SIM RADAR MODEL SOLUTIONS
OVR THE LAST FEW HRS IS TO SHOW LESS NWRD PROGRESS OF STEADY RN
INTO OUR FA FROM JUST THE LAST UPDATE. THIS SEEMS TO MATCH UP WITH
TRENDS SEEN IN LATEST REAL TIME RADAR REF IMAGERY WHICH SHOWS RN
STRUGGLING TO MAKE IT INTO E CNTRL PTNS OF THE FA LATE THIS EVE
AND SFC OBS AND SAT IMAGERY WHICH SHOWS INTERMITTENT BREAKS IN
CLD CVR WITH A WEDGE OF DRY SUB CLD AIR OVR THE NW HLF OF THE FA
XTNDG EWRD FROM QB. BASED ON THESE TRENDS...WE LOWERED FORECAST
QPF AND POPS SOMEWHAT FOR THE REMAINDER OF THE OVRNGT OVR THE N
AND CNTRL THIRDS OF THE FA. WITH BREAKS IN THE OVC OVR THE FAR
NW...TEMPS HAVE FALLEN A LITTLE FASTER ACROSS BROAD VLY LCTNS OVR
THIS PTN OF THE FA...SO WE LOWERED FCST LOWS OVR NW PTNS OF
AROOSTOOK COUNTY WITH THE UPDATE OF FCST HRLY TEMPS OVRNGT FOR ALL
OF THE REGION.
ORGNL DISC: LOW PRESSURE CURRENTLY SPINNING WELL OFF THE MID
ATLANTIC COAST WILL LIFT NORTHWARD TOWARD NOVA SCOTIA THIS
AFTERNOON AND EVENING, THEN RAPIDLY MOVE TO THE EAST LATE TONIGHT.
WE`RE ALREADY SEEING MOISTURE LIFTING INTO SOUTHERN PORTIONS OF
OUR FORECAST AREA, AS EVIDENCED BY PERIODS OF DRIZZLE AND FOG. THE
RAIN WON`T BE FAR BEHIND AND SHOULD BEGIN TO MOVE ONSHORE BY EARLY
THIS EVENING. AS WITH LAST NIGHT`S RAIN, DOWNEAST AREAS WILL SEE
THE BULK OF THE PRECIPITATION, WITH AREAS NORTH OF A HOULTON TO
MILLINOCKET LINE SEEING JUST SOME SHOWERS. LITTLE TO NO RAINFALL
IS EXPECTED IN THE SAINT JOHN VALLEY. COASTAL AREAS COULD SEE
ANOTHER HALF INCH OR SO, WITH FAR WASHINGTON COUNTY RECEIVING A
LITTLE MORE. THE RAIN WILL BE A QUICK SHOT GIVEN THE LOW`S RAPID
FORWARD PROGRESSION AND WILL EXIT INTO NEW BRUNSWICK BY DAYBREAK
FRIDAY. IT`LL BE A BIT BREEZY OVERNIGHT AS WELL, ESPECIALLY
DOWNEAST, AS THE PRESSURE GRADIENT TIGHTENS IN RESPONSE TO THE
PASSING LOW. OVERNIGHT LOWS WILL RANGE FROM THE UPPER 30S IN THE
NORTH WOODS TO THE LOWER 40S DOWNEAST.
PLEASANT WEATHER MOVES IN FOR FRIDAY AS THE LOW CONTINUES TO PULL
AWAY, ALLOWING HIGH PRESSURE TO BUILD IN ITS WAKE. SKIES WILL
GRADUALLY CLEAR FROM NORTHWEST TO SOUTHEAST THROUGH THE DAY; EXPECT
EVERYONE WILL SEE AT LEAST PARTIAL SUN BY MID AFTERNOON. HIGHS WILL
REACH INTO TO THE LOWER 60S IN MOST SPOTS, THE EXCEPTION WILL BE
DOWNEAST WHERE THE CLOUDS WILL HANG IN LONGEST; HIGHS WILL BE IN THE
MID TO UPPER 50S THERE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
THE WEEKEND WILL FEATURE THE CUT-OFF LOW FINALLY GETTING ABSORBED
BACK INTO THE MAIN WEATHER PATTERN AND A DIGGING TROF MOVING
ACROSS QUEBEC. FRIDAY NIGHT WILL START OFF CLEAR, BUT HIGH CLOUDS
WILL SPREAD BACK NORTH AFTER MIDNIGHT AND THICKEN THRU THE DAY ON
SAT. AS THE CUT-OFF GETS ABSORBED BACK INTO THE UPR TROF AND ITS
MOISTURE STREAMS BACK NORTH AHEAD OF THE ADVANCING COLD FRONT, MAY
HAVE SOME ISO TO SCT SHWRS LATE SAT AM THRU SAT NIGHT. THE BEST
CHANCE FOR RAIN WILL BE AS THE FRONT CROSSES THE CWA DURING THE
AFTN AND EVE ON SUN. THERE ARE MINOR DIFFERENCES IN THE EXACT
TIMING OF THE FRONT, BUT FELT CONFIDENT TO INTRODUCE LKLY TO LOW-
END DEF POPS. CURRENTLY GOING FOR QPF OF A QUARTER TO HALF AN
INCH. TEMPS WILL BE ABV NRML SAT, BUT INCR CLOUDS AND AFTN PRECIP
WILL LIKELY TAMP DOWN TEMPS A BIT ON SUN.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SOME PRECIP LKLY TO BE ONGOING ALONG THE N AND E BORDERS AT 00Z
MON START OF THE LONG TERM, BUT QUICKLY DIMINISHES. HWVR,
SIGNIFICANT DISAGREEMENTS QUICKLY DEVELOP REGARDING THE SPEED OF
THE UPR TROF DEPARTING THE REGION, AND THE POTENTIAL FOR CLOUDS
AND A FEW SHWRS TO LINGER UP NORTH. MODELS SHOW A WEAK SFC SYSTEM
MOVING ACROSS SRN NEW ENG TUE NIGHT THRU WED NIGHT, BUT ALSO
DISAGREE QUITE A BIT ON THE NORTHWARD EXTENT OF PRECIP, SO KEPT
POPS AT CHC FOR NOW. 12Z ECMWF SEEMS TO BE CLOSER TO THE GFS AND
CMC SOLUTIONS, SO FUTURE FORECAST CYCLES MAY BE ABLE TO HAVE A BIT
MORE CERTAINTY IF THAT TREND HOLDS. TEMPS ON MON LKLY TO BE A BIT
BLW NRML BEHIND THE FRONT, BUT QUICKLY REBOUND TO NEAR OR A BIT
ABV NRML THE REST OF THE LONG TERM.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: ALL SITES CURRENTLY UNDER PREVAILING MVFR CEILINGS AND
THIS SHOULD BE THE GENERAL TREND THROUGH 00Z FRIDAY, THOUGH THE
NORTHERN TERMINALS MAY SEE A PERIOD OF VFR. THEN CONDITIONS WILL
DETERIORATE AS LOW PRESSURE SWINGS BY TO THE SOUTHEAST AND BRINGS
A PERIOD OF RAIN. KBGR AND KBHB WILL SEE THE STEADIEST RAIN AS
WELL AS THE LONGEST PERIOD OF IFR CONDITIONS (00Z-11Z). THE
NORTHERN TERMINALS ARE MORE LIKELY TO SEE JUST SOME SHOWERS AT
MOST, BUT CEILINGS WILL LOWER TO BELOW 1000 FT LATE TONIGHT.
CONDITIONS WILL IMPROVE AFTER 12Z AS SKIES CLEAR FROM NORTHWEST TO
SOUTHEAST. ALL SITES VFR BY 18Z.
SHORT TERM: EXPECT VFR AT ALL SITES FRI NIGHT, EXCEPT PATCHY FOG
CAN`T BE RULED OUT, SPCLY KHUL SOUTH TO THE COAST AS WINDS MAY BE
A BIT LIGHTER THERE. HIGH CIGS SPREAD OVER THE CWA FROM SOUTH TO
NORTH SAT AND SAT NIGHT. EXPECT CONTINUING VFR AT FIRST, THOUGH
ANY SHWRS LATER SAT INTO SUN AM COULD BRING SOME MVFR CONDITIONS.
AS THE FRONT PUSHES THRU THE STATE FROM W TO E BETWEEN 18Z SUN AND
06Z MON, EXPECT MVFR TO IFR CONDITIONS FOR ALL SITES. CIGS WILL
INCREASE ONCE THE FRONT CLEARS THE AREA, BUT AS THE UPR TROF
REMAINS OVER HEAD, COULD SEE SOME MVFR CIGS AT TIMES MON, SPCLY IF
ANY SHWRS LINGER.
&&
.MARINE...
NEAR TERM: THE SMALL CRAFT ADVISORY REMAINS IN PLACE AS WINDS
WILL CONTINUE TO GUST TO 30 KT THIS EVENING AND OVERNIGHT. THIS
WILL LIKELY NEED TO BE CONVERTED OVER TO AN SCA FOR HAZARDOUS SEAS
FRIDAY MORNING TO EXTEND THROUGH THE DAY. SEAS WILL BE 5-9 FEET.
SHORT TERM: WINDS EXPECTED TO REMAIN BELOW SCA CRITERIA THRU THE
SHORT TERM, BUT SEAS WILL REMAIN ABOVE CRITERIA LEVELS FRI NIGHT
THRU SAT. SEAS LOOK TO SETTLE SOME SAT NIGHT INTO SUN, AND MAY
ALLOW THE ANTICIPATED SCA FOR HAZARDOUS SEAS TO BE DROPPED.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...KREDENSOR
LONG TERM...KREDENSOR
AVIATION...VJN/KREDENSOR
MARINE...VJN/KREDENSOR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
718 PM EDT THU MAY 5 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 354 PM EDT THU MAY 5 2016
12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW A NNW FLOW ALOFT
DOMINATING THE WRN GREAT LKS BTWN DEEP UPR TROF OVER THE E AND AN
UPR RDG IN CENTRAL NAMERICA. A SFC HI PRES RDG STRETCHING FM THE UPR
MIDWEST INTO WRN QUEBEC AS WELL AS DRY AIRMASS SHOWN ON THE 12Z GRB
RAOB IS BRINGING A MOSUNNY DAY TO UPR MI...BUT MORE MAINLY MID/HI
CLDS RELATED TO WAA IN THE SW FLOW ON THE BACK SIDE OF THE RDG ARE
PRESENT FM WRN LK SUP INTO CENTRAL ONTARIO. THERE WERE SOME SHOWERS
UNDER THESE CLDS OVER MN WHERE MID LVL LAPSE RATES HAVE BEEN
STEEPER...BUT ABSENCE OF FORCING OTHER THAN WAA AND RELATIVELY DRY
NATURE OF THE AIRMASS ARE LIMITING THE COVERAGE OF THIS PCPN...WITH
A DIMINISHING TREND IN RECENT HRS.
TNGT...AS SFC HI PRES RDG CONTINUES TO SLIDE SEWD...SW FLOW/WAA ARE
PROGGED TO DOMINATE THE CWA. EXPECT SOME MID/HI CLDS RELATED TO THIS
WAA TO PASS OVER THE CWA MAINLY THRU 06Z BEFORE SUBSIDENCE RELATED
TO SHARPENING H7 RDG AXIS DRIES UP THESE CLDS. CONSIDERED ADDING
SOME ISOLD SHOWERS LATE THIS AFTN/THIS EVNG OVER THE FAR W WHERE NAM
SHOWS POCKET OF H7-5 LAPSE RATES ARND 8C/KM AND SOME OF THE HIER RES
MODELS GENERATE SPOTTY QPF...BUT LATEST RADAR TRENDS SUG THE AIRMASS
IS SO DRY IN A RELATIVE SENSE THAT THE DRY FCST GUIDANCE IS ON THE
RIGHT TRACK. COMBINATION OF THE WAA CLDS AND LLVL WARMING RELATED TO
STEADY SW FLOW WL HOLD MIN TEMPS UP MUCH HIER THAN THIS MRNG. IN
FACT...READINGS MAY NOT FALL BLO 50 OVER THE FAR W FM IRONWOOD TO
ONTONAGON WHERE THE SW FLOW WL DOWNSLOPE.
FRI...UPR MI WL BE IN THE WARM SECTOR BTWN DEPARTING SFC HI PRES RDG
TO THE SE AND SFC LO PRES TRACKING ACROSS NW ONTARIO AHEAD OF SHRTWV
MOVING OVER WRN RDG AND INTO FAR NW ONTARIO LATE IN THE DAY. WITH
H85 TEMPS FCST AS HI AS 18C AND A GOOD DEAL OF SUNSHINE WITHIN
LINGERING DRY AIRMASS...TEMPS AWAY FM THE MODERATING INFLUENCE OF
MAINLY LK MI OVER THE W HALF WL RISE WELL INTO THE 80S AND PERHAPS
ARPCH 90 AT A FEW LOCATIONS. WITH DAYTIME MIXING CAUSING SFC DEWPTS
TO DROP AT LEAST CLOSE TO 40 IN THE AFTN...EXPECT MIN RH TO DIP NEAR
20 PCT AT A FEW PLACES. ALTHOUGH STRONG WINDS ARE NOT EXPECTED WITH
GUSTS UP TO ARND 20 MPH...FIRE WX CONCERNS WL BE ELEVATED. WINDS WL
BE A BIT STRONGER OVER THE E...BUT MODERATION OFF LK MI WL LIMIT
FIRE WX CONCERNS THERE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 319 PM EDT THU MAY 5 2016
LONG TERM STARTS AT 00Z SAT WITH THE UPPER RIDGE AND WARM AIRMASS
OVER THE REGION. 850MB TEMPS WILL BE AROUND 17C AT 00Z...BUT WILL
DROP TO 1-2C BY 18Z SAT BEHIND A SHORTWAVE TROUGH AND COLD FRONT.
MODELS CONTINUE TO PAINT UP TO 0.20 INCHES OF QPF OVER MUCH OF THE
AREA FRI NIGHT...BETWEEN 00Z AND 12Z SAT...BUT SOME AREAS MAY NOT
EVEN SEE 0.10 INCHES. EXPECT THUNDERSTORMS AS ELEVATED INSTABILITY
(CAPE UP TO 750 J/KG)...BUT NO SEVERE THUNDERSTORMS DUE TO WEAK
SHEAR (0-6KM BULK SHEAR AROUND 20KTS).
DRY AIR MOVES BACK IN ON SAT WITH SUNNY SKIES AND MIN RH VALUES IN
THE MID 20S OVER THE INTERIOR W AROUND AROUND 40 PERCENT INTERIOR E.
WINDS WILL BE LIGHT OVER THE W AND WILL GUST UP TO 25 MPH OVER THE
E. IT WILL BE COOLER WITH HIGHS IN THE 50S NEAR LAKE SUPERIOR AND E
AND AROUND 60 INTERIOR W. CERTAINLY NOT A CRITICAL FIRE WEATHER DAY
BUT THE DRY AIR WILL PROBABLY NEGATE ANY MOISTURE WE GET FRI NIGHT.
CAN NOT COMPLETELY RULE OUT A FEW LIGHT SHOWERS OVER NORTHERN LAKE
SUPERIOR AND POSSIBLY THE KEWEENAW AND ERN UPPER MI SAT EVENING INTO
SAT NIGHT AS ANOTHER SHORTWAVE PASSES N OF THE AREA...BUT THINK
POTENTIAL IS LOW ENOUGH TO LEAVE OUT OF THE FORECAST FOR LAND AREAS.
SUN WILL SEE SIMILAR TEMPS/RH/CLOUDS TO SAT...BUT WITH LOWER WINDS.
MON AND TUE HAD APPEARED WET FROM EARLIER MODEL RUNS...BUT THOSE
MODELS HAVE TRENDED DRIER. NOW ONLY THE 00Z/05 ECMWF SHOWS PRECIP
OVER THE CWA...EXCEPT THE GLOBAL GEM WHICH HAS PRECIP BRUSHING SRN
MENOMINEE COUNTY. WILL ACCORDINGLY START A DECREASING TREND FOR THE
POP FORECAST FOR MON THROUGH TUE. NO PRECIP EXPECTED TUE NIGHT
THROUGH THU.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 717 PM EDT THU MAY 5 2016
EXPECT VFR CONDITIONS AND RELATIVELY LIGHT WINDS MOSTLY UNDER 10KT
TO PREVAIL THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW AS A DRY AIR MASS
WILL LINGER DESPITE HIGH PRES EXITING AND A COLD FRONT APPROACHING
FRI AFTN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EDT THU MAY 5 2016
SSW WINDS UP TO 20 KTS AHEAD OF AN APPROACHING COLD FRONT WILL SHIFT
TO THE N AT 20-25 KTS FRI NIGHT INTO SAT FOLLOWING THE PASSAGE OF
THIS BOUNDARY. AS HI PRES BUILDS OVER THE AREA BY LATE IN THE
WEEKEND...THESE WINDS WILL DIMINISH UNDER 15-20 KTS INTO EARLY NEXT
WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
402 PM EDT WED MAY 4 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 401 PM EDT WED MAY 4 2016
WV IMAGERY AND RAP ANALYSIS INDICATED AN AMPLIFIED PATTERN WITH A
RIDGE FROM HE ROCKIES INTO SASK AND A TROUGH FROM JAMES BAY THROUGH
ERN UPPER MI TO INDIANA. AT THE SFC...GUSTY NORTH WINDS PREVAILED
THROUGH LAKE SUPERIOR AND UPPER MI BETWEEN 1001 MB LOW PRES OVER SRN
LOWER MI AND A RIDGE FROM NW ONTARIO INTO THE ERN DAKOTAS. VIS
SATELLITE LOOP SHOWED THINNING CLOUDS OVER UPPER MI AS THE 900-700
MB MOISTURE THINS OUT WITH DAYTIME MIXING AND THE RIDGE BUILDING
INTO THE AREA.
TONIGHT...ALTHOUGH THE CLEARING TREND HAS BEEN A BIT SLOWER THAN
FCST...EXPECT THAT BTWN 21Z-24Z MOST OF THE REMAINING CLOUDS WILL
DISSIPATE. FAVORABLE RADIATIONAL COOLING CONDITIONS OVER THE WEST
WHERE WINDS WILL BE LIGHTEST WILL ALLOW TEMPS TO DROP TO THE LOWER
END OF GUIDANCE WITH MIN READINGS IN THE MID 20S OVER THE
INTERIOR. OTHERWISE...EXPECT LOWS IN THE LOW TO MID 30S.
THURSDAY...MID LEVEL AND SFC RIDGING INTO THE WRN LAKES WILL RESULT
IN MOSTLY SUNNY SKIES AND WARMER WEATHER. EXPECT TEMPS TO CLIMB INTO
MID TO UPPER 50S INLAND. THE WEAK GRADIENT WILL ALLOW PROMINENT LAKE
BREEZE DEVELOPMENT KEEPING MAX READINGS IN THE 50S NEAR THE GREAT
LAKES.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 PM EDT WED MAY 4 2016
UPPER TROUGH MOVES FROM THE GREAT LAKES TO THE SOUTHEAST CONUS BY
FRI...ALLOWING UPPER RIDGE AND SFC WARM FRONT TO BRING WARM
SUMMERLIKE TEMPS BRIEFLY OVER THE GREAT LAKES FOR FRI AFTN. INITIAL
WARM AIR ADVECTION ON EDGE OF STEEPER H7-H5 LAPSE RATES UP TO 8C/KM
COULD TRIGGER ELEVATED CONVECTION OVER MAINLY LK SUPERIOR THU NIGHT
INTO FRI MORNING WHERE STRONGEST H85 WARM AIR ADVECTION LINKS UP WITH
SUFFICIENT H85-H7 MOISTURE. FARTHER SOUTH ACROSS UPR MICHIGAN...EXPECT
SCT MID CLOUDS TO START THE DAY FRI...THEN MOSTLY SUNNY SKIES BY AFTN
WITH H85 TEMPS TO +16 SUPPORTS GOING FORECAST OF 70S EAST DOWNSTREAM
OF LK MICHIGAN TO MID-UPR 80S WEST IN THE AFTN. DWPNTS SHOULD BE IN
THE LOW TO MID 40S...SO RH VALUES DROP TO 20-25 PCT IN THE AFTN. SW-S
WINDS LOOKS SLIGHTLY STRONGER THAN EARLIER MODEL FORECASTS SHOWED BUT
STILL GUSTS PEAKING AT 20 MPH WILL KEEP AREA BLO CRITICAL FIRE
WEATHER THRESHOLDS. WILL BE SOMETHING TO KEEP EYE ON IN TERMS OF IF
STRONGER TREND IN WINDS CONTINUES. NAM/GFS TRY TO SHOW POCKET OF
DWPNTS FM LOW-MID 50S AND THUS GENERATE SBCAPE OVER 1000J/KG OVER
CNTRL CWA FRI AFTN AND SHOW SOME CONVECTION. COULD MAYBE SEE DWPNTS
UP TO 50 LOCALLY MAINLY NEAR WI BORDER SOUTH CNTRL. OVERALL PATTERN
WITH LOWERING H85-H7 RH FAVORS DEEPER MIXING AND LOWER DWPNTS...SO
WILL KEEP FRI AFTN WARM BUT WITH NO CHANCE OF SHRA/TSRA.
WARMTH WILL BE BRIEF AS SHORTWAVE TROUGH CROSSING NORTHERN ONTARIO
PUSHES SFC-H85 COLD FRONT ACROSS UPR MICHIGAN LATE EVENING NORTHWEST
TO OVERNIGHT SCNTRL. EVEN THOUGH STRONGER PVA STAYS NORTH CLOSER TO
TRACK OF MAIN SHORTWAVE ACROSS ONTARIO...DIFFLUENT H5-H3 FLOW AND
CONVERGENCE ALONG FRONT FAVORS BROKEN BAND OF SHOWERS AND POSSIBLE
TSRA WITH CONDITIONALLY UNSTABLE H7-H5 LAPSE RATES NEAR 7C/KM. AS
FOR STRENGTH OF TSRA...UNLESS FRONT ARRIVES 00Z-03Z INSTEAD OF MORE
03Z-06Z...LIKELY LOOKING AT ELEVATED STORMS. ELEVATED MUCAPE
FORECASTS VARY WITH NAM SHOWING UP TO 2000J/KG AT 00Z SAT MAINLY
OVER NORTHERN WI WHILE GFS/ECMWF ARE MAINLY 500J/KG OR LESS. ECMWF
KEEPS MOST INSTABILITY FARTHER WEST/SOUTHWEST OF CWA FRI NIGHT. MEAN
FLOW IS WNW SO IF ECMWF IS CORRECT...MOST OF TSRA WOULD REMAIN
SOUTHWEST OF CWA. IF MODELS WITH MORE BULLISH INSTABILITY FARTHER
EAST ARE CORRECT...THERE IS ENOUGH EFFECTIVE BULK SHEAR TO RESULT IN
STRONGER STORMS. SPC HAS MOST OF CWA WITHIN GENERAL TSRA RISK FRI
AND FRI NIGHT WHICH SEEMS REASONABLE WITH MAIN HINDRANCE THE DEGREE
OF INSTABILITY. ATTM LOOKS LIKE TOTAL RAINFALL FRI NIGHT INTO EARLY
SAT WILL BE LESS THAN 0.25 INCHES AT MOST LOCATIONS...SIMILAR TO
FROPA THAT JUST OCCURRED TUE AFTN INTO THIS MORNING.
TURNING BREEZY AND MUCH COOLER ON SAT BEHIND THE FRONT. WILL NOT BE
A COOL AS TODAY BUT THE COOLING WILL BE SIGNIFICANT COMPARED TO THE
SUMMERTIME WARMTH ON FRI...ESPECIALLY NEAR LK SUPERIOR. SHOULD DRY
OUT WITH RH VALUES DOWN TO 25-30 PCT SAT AFTN. IF SHOWERS AND TSRA
ARE MORE SPOTTY ON FRI NIGHT RESULTING IN MINIMAL RAIN...THE
STRONGER WINDS AND LOW RH WOULD RESULT IN SOME FIRE WEATHER ISSUES
ON SAT AFTN OVER INTERIOR WEST AS TEMPS STILL REACH INTO THE 60S.
RE-INFORCING SHORTWAVE DIGGING INTO MEAN TROUGH OVER GREAT LAKES AND
POCKET OF STEEPER LAPSE RATES OVER 7C/KM MAY BRING ANOTHER CHANCE OF
ISOLD-SCATTERED ELEVATED CONVECTION SAT NIGHT MAINLY OVER EAST HALF.
A BIT QUICKER TREND IN MODELS SUGGESTS SHRA/TSRA COULD MOVE OVER
KEWEENAW AS EARLY AS MID-LATE SAT AFTN. OTHERWISE...REST OF LONG
TERM SUN INTO MIDDLE OF NEXT WEEK LOOKS GENERALLY DRY. WILL HAVE TO
KEEP SLIGHT CHANCES IN THERE IN CASE UPPER TROUGH MOVING OUT OF
PLAINS COMES FAR ENOUGH NORTH TO BRING SOME SHOWERS TUE AND/OR WED.
LATEST ECMWF WOULD POINT TO AT LEAST A SMALL CHANCE...ESPECIALLY
SOUTH. TEMPS SHOULD BE NEAR NORMAL WITH 60S INLAND AND 50S ALONG THE
GREAT LAKES AS HIGH PRESSURE RIDGE IN VCNTY RESULTS IN LAKE BREEZES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 200 PM EDT WED MAY 4 2016
LOW-LEVEL MOISTURE BEHIND A MID-LEVEL LOW PASSING TO THE EAST WILL
KEEP MVFR CIGS GOING AT KCMX AND KSAW THROUGH MUCH OF THE AFTERNOON.
CLOUDS WILL SCATTER OUT FROM WEST TO EAST DURING THE
AFTERNOON...WITH ALL SITES SKC AFTER 00Z. EXPECT GUSTY NORTH WINDS TO
25 KNOTS TODAY AT BOTH KCMX AND KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 401 PM EDT WED MAY 4 2016
GUSTY NORTH WINDS TO 25 KNOTS OVER ERN LAKE SUPERIOR WILL QUICKLY
DIMINISH TONIGHT AS HIGH PRESSURE BUILDS ACROSS THE REGION. EXPECT
WINDS TO BE GENERALLY SOUTHERLY UNDER 20 KNOTS THURSDAY THROUGH
FRIDAY. A COLD FRONT WILL THEN SWEEP ACROSS LAKE SUPERIOR FRIDAY
EVENING...BRINGING A QUICK ROUND OF NW WINDS TO 30 KNOTS LATE FRIDAY
NIGHT AND SATURDAY MORNING. WINDS WILL THEN REMAIN WESTERLY UNDER 20
KNOTS SATURDAY AFTERNOON THROUGH SUNDAY BEFORE HIGH PRESSURE BRINGS
LIGHT WINDS SUNDAY NIGHT INTO MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
141 PM EDT WED MAY 4 2016
.AVIATION...
UPPER LOW AND SURFACE LOW WERE SPINNING OVER SOUTHWEST LOWER
MICHIGAN THIS AFTERNOON AND WILL SLOWLY EXIT SOUTHEAST OVERNIGHT.
IN THE MEANTIME SEVERAL BAND OF SHOWERS WERE SPIRALLING AROUND
THESE LOWS ACROSS SOUTHEAST MI. THERE WERE EMBEDDED THUNDERSTORMS
TOO. EXPECT THIS TO CONTINUE THROUGH THE AFTERNOON...BUT SHOW A
DECREASE TOWARD 00Z AS BOTH THE LOWS SPIN AWAY AND INSTABILITY
DECREASES. WINDS WILL BE STRONG ENOUGH AROUND THIS LOW EARLY...10
TO 15 KTS AND THE DIRECTION WILL BE DIFFICULT GIVEN THE LOW
PASSING CLOSE TO THE DETROIT AREA TAFS. ALSO EXPECT SOME MVFR
CEILINGS AND VISIBILITIES IN THE SHOWERS.
SOME SHOWERS WILL LINGER INTO THE EVENING BUT BY 03Z ALL TAF SITES
WILL BE DRY. CEILINGS FROM 4000 TO 6000 FEET EXPECTED THROUGH MUCH
OF THE NIGHT. SOME SUGGESTION OF STRATUS WITH RECENT RAINS AND
NORTHEAST FLOW OFF OF THE GREAT LAKES AND HAVE A TEMPO GROUP FOR
THE NORTHERN TAF SITES AROUND DAYBREAK. THURSDAY WILL HAVE MORE
DRYING WITH SCATTERED CUMULUS AND A NORTH WIND AROUND 10 KTS.
FOR DTW...THUNDER THREAT HAS ALREADY ROTATED NORTH AND EAST OF DTW
FOR THE AFTERNOON. STILL BANDS OF SHOWERS WILL MOVE IN FOR MVFR
VISIBILITIES AND CEILING THROUGH THE AFTERNOON. AFTER 02Z SHOWERS
END AND CEILINGS IMPROVE TO 4000 TO 6000 FEET AND BECOME SCATTERED
BY DAYBREAK.
//DTW THRESHOLD PROBABILITIES...
* MEDIUM IN CEILINGS AT OR BELOW 5000 THROUGH 05Z.
* LOW IN THUNDERSTORMS IMPACTING THE AREA THROUGH 21Z.
&&
.PREV DISCUSSION...ISSUED 1236 PM EDT WED MAY 4 2016
UPDATE...
WATER VAPOR IMAGERY INDICATES UPPER ENERGY IS STARTING TO CLOSE
OFF OVER SOUTHWEST MICHIGAN AS PREDICTED BY NWP SUITE. THIS SHOULD
PIVOT THE NORTH-SOUTH ORIENTATED BAND OF PRECIPITATION THAT WAS
OVER WESTERN MICHIGAN THIS MORNING MORE INTO SOUTHEAST LOWER
MICHIGAN AS CYCLONIC FLOW INCREASES AROUND THE SYSTEM AND THE
DEFORMATION BAND TAKES ON A MORE NORTHWEST TO SOUTHEAST
ORIENTATION. THIS IS ALREADY STARTING TO TAKE SHAPE PER LATEST
RADAR IMAGERY. BAND OF HEAVIEST RAIN IS EXPECTED TO STRETCH
ROUGHLY FROM THE SAGINAW VALLEY DOWN THROUGH THE DETROIT AREA THIS
AFTERNOON BEFORE DROPPING SOUTH EARLY TONIGHT AS THE LOW CENTER
WORKS SOUTHWARD. SOME MINOR ADJUSTMENTS WERE MADE TO PRECIPITATION
PLACEMENT BASED ON RADAR TRENDS AND LATEST RUNS OF HIGHER-RES
MODELS (HRRR...NAM12...NMM)...WITH HIGHEST POPS AND QPF SHIFTED
VERY SLIGHTLY TO THE WEST AND SOUTH. BIGGEST CHANGES WERE IN THE
FORM OF HIGHER POPS OVER LENAWEE COUNTY...LOWER POPS OVER THE
THUMB...AND A MORE PRONOUNCED DRYING TREND OVER THE NORTHERN HALF
OF THE FORECAST AREA EARLY TONIGHT.
STRONGER SHOWERS AND THUNDERSTORMS HAVE ALSO STARTED TO DEVELOP
EARLY THIS AFTERNOON AS WARMING OCCURS WITH DIURNAL HEATING IN THE
LOW LEVELS AND THE UPPER LEVELS COOL IN THE PROXIMITY OF THE
DEVELOPING UPPER LOW. THIS HAS RESULTED IN A FEW HUNDRED J/KG OF
MU CAPE PER LATEST SPC ANALYSIS. STILL NOT EXPECTING SEVERE
WEATHER...BUT LOCALLY HEAVY RAINFALL IS EXPECTED.
PREV DISCUSSION...ISSUED 337 AM EDT WED MAY 4 2016
DISCUSSION...
IMPRESSIVE SPREAD STILL EXISTS AMONG THE GUIDANCE THIS MORNING AS
FORECAST LEAD TIME DIMINISHES TO ZERO. WATER VAPOR IMAGERY SHOWS A
POWERFUL LEAD WAVE DIGGING INTO THE MIDWEST WITH A NEARLY
EQUIVALENTLY STRONG TRAILING WAVE OVER WEST-CENTRAL WISCONSIN AT
07Z. THE TRAILING WAVE HAS BEEN POORLY RESOLVED BY MANY MEMBERS OF
THE GUIDANCE...THE RAP APPEARING TO HANDLE IT THE BEST. EVEN SO, THE
RAPID REFRESH IS STRUGGLING TO KEEP UP WITH 3-HOUR PRESSURE FALLS OF
3-5MB THIS MORNING.
EXPANDING SHOWER COVERAGE IN ADVANCE OF THE WAVE IS OCCURRING WITHIN
THE CORRIDOR OF MOISTURE TRANSPORT THAT HAS EMERGED OVER SOUTHWEST
MICHIGAN DURING THE LAST COUPLE OF HOURS. FOR NOW, THIS ACTIVITY IS
STRUGGLING TO PENETRATE THE CWA DUE TO ANTECEDENT DRY AIR EVIDENT ON
THE 00Z DTX SOUNDING. COVERAGE IS EXPECTED TO INCREASE IN SE
MICHIGAN OVER THE NEXT SEVERAL HOURS AS THE COLUMN SATURATES, LARGE
SCALE FORCING INCREASES, AND DIURNAL DESTABILIZATION GETS UNDERWAY.
THE PRIMARY FEATURE OF INTEREST, THE BAND OF RAIN WITH EMBEDDED
HEAVY SHOWERS, IS SO FAR BEHAVING AS ANTICIPATED. ITS NARROW
STRUCTURE IS ATTRIBUTABLE TO DEEP LAYER LINEAR/CONVERGENT FORCING
ALONG THE STRONG TROUGH AXIS. THE UPPER TROUGH WILL BEGIN THE
PROCESS OF CLOSING OFF LATE THIS MORNING OR EARLY THIS AFTERNOON AS
ENERGY CONTINUES TO FLOOD SOUTH INTO THE WESTERN GREAT LAKES. AS
THIS OCCURS, THE BAND WILL STALL AND PIVOT IN CYCLONIC FASHION WITH
PRECIPITATION RATES INTENSIFYING AS DEFORMATION FORCING RAMPS UP
WEST OF US-23. IN ADDITION, DIURNAL HEATING AND STEEP LAPSE RATES
WILL CONTRIBUTE TO A LOW DENSITY CAPE PROFILE CHARACTERIZED BY A FEW
HUNDRED J/KG OF POTENTIAL ENERGY. SKINNY CAPE WITHIN PERSISTENT
STRONG DEFORMATION WILL BE SUFFICIENT TO PRODUCE A SOLID HALF INCH
TO THREE QUARTERS OF RAIN OVER WESTERN AREAS. A LOCALIZED AREA -
PERHAPS JUST THE FOOTPRINT OF A COUNTY OR TWO -COULD EASILY SEE OVER
AN INCH IN THIS SETUP. MOST LIKELY AREA FOR HEAVIEST RAIN WILL BE
BETWEEN LIVINGSTON AND BAY COUNTIES WEST OF US-23/I-75. THE LACK OF
SIGNIFICANT MOISTURE (PWAT < 0.80") AND A VERY SHALLOW (< 5KFT) WARM
CLOUD LAYER WILL PUT A DEFINITE CEILING ON POTENTIAL RAINFALL
AMOUNTS SO THINGS WILL NOT GET OUT OF CONTROL.
UNCERTAINTY IN PRECIP POTENTIAL INCREASES FOR EASTERN AREAS,
INCLUDING DETROIT METRO, AS THE CONVERGENT RAINFALL BAND STALLS UPON
THE MID-LEVEL LOW CLOSING OFF. HOWEVER, LATEST RAP SIMULATIONS SHOW
RESPECTABLE CAPE OF A FEW HUNDRED J/KG ACROSS THE EAST. WILL LIKELY
SEE SOME SUBTLE RIDGING FORCED OVER THE EASTERN CWA DURING PEAK
HEATING, BUT LOW/MID-LEVEL THETA MAY BE JUST ENOUGH IN THE STEEP
LAPSE RATE ENVIRONMENT TO SERVE AS A TRIGGER FOR DISORGANIZED SHOWER
ACTIVITY DURING THE AFTERNOON. THUS, LIKELY POPS REMAIN IN PLACE IN
SPITE OF THE WESTWARD ADJUSTMENT FROM YESTERDAY MORNING`S FORECAST.
WARMING TREND INTO THE 60S THURSDAY AND LOW 70S FRIDAY AS RIDGING IS
FORCED THROUGH THE CWA DURING THE LATE WEEK PERIOD. LINGERING
CYCLONIC FLOW AND MOISTURE WILL KEEP A PARTIAL COVERAGE OF DIURNAL
CU AND POSSIBLY JUST AN ISOLATED SHOWER IN THE FORECAST THROUGH
THURSDAY. DEEP LAYER SUBSIDENCE WILL SUPPORT FULL SUN AND MUCH
WARMER TEMPS ON FRIDAY AS THE BOUNDARY LAYER TAPS INTO 850MB TEMPS
IN THE HIGH SINGLE DIGITS BY AFTERNOON.
MARINE...
MODEST NORTHERLY WINDS WILL BEGIN TO TAKE HOLD ACROSS THE CENTRAL
GREAT LAKES TODAY AS LOW PRESSURE PIVOTS THROUGH LOWER MICHIGAN.
SLIGHT INCREASE IN NORTHERLY FLOW TONIGHT INTO EARLY THURSDAY MAY
LEAD TO A BRIEF PERIOD OF GUSTS NEAR 20 KNOTS ACROSS SOUTHERN
SECTIONS OF LAKE HURON DURING THIS TIME. THE ONSHORE FLOW WILL ALSO
BRING A PERIOD OF ELEVATED WAVE CONDITIONS ALONG THE THUMB DURING
THIS TIME. HOWEVER SMALL CRAFT ADVISORY LEVEL CONDITIONS ARE
CURRENTLY NOT ANTICIPATED. HIGH PRESSURE WILL THEN BRING TRANQUIL
MARINE CONDITIONS FOR THE LATE WEEK PERIOD.
HYDROLOGY...
STRENGTHENING LOW PRESSURE WILL DROP SOUTHEAST ACROSS THE STATE
THROUGH THIS EVENING. A PERIOD OF STRONG FORCING ASSOCIATED WITH
THIS SYSTEM WILL SLIDE INTO WESTERN PORTIONS SE MICHIGAN LATE TODAY.
THIS WILL FOCUS AN AXIS OF HEAVIER RAINFALL ALONG HIGHWAY 23
CORRIDOR...WHERE RAINFALL AMOUNTS FROM ONE HALF TO THREE QUARTERS OF
AN INCH ARE EXPECTED. DECREASING RAINFALL AMOUNTS WITH EASTWARD
EXTENT...LEAVING EASTERN PORTIONS OF METRO DETROIT NORTHWARD INTO
THE THUMB WITH LESS THAN A QUARTER OF AN INCH. THE BULK OF THIS
RAINFALL WILL OCCUR DURING THE AFTERNOON AND EARLY EVENING HOURS.
RAINFALL WILL TAPER OFF QUICKLY EARLY TONIGHT WITH GENERALLY DRY
WEATHER THURSDAY AND FRIDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....RBP
UPDATE.......HLO
DISCUSSION...JVC
MARINE.......MR
HYDROLOGY....MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1236 PM EDT WED MAY 4 2016
.UPDATE...
WATER VAPOR IMAGERY INDICATES UPPER ENERGY IS STARTING TO CLOSE
OFF OVER SOUTHWEST MICHIGAN AS PREDICTED BY NWP SUITE. THIS SHOULD
PIVOT THE NORTH-SOUTH ORIENTATED BAND OF PRECIPITATION THAT WAS
OVER WESTERN MICHIGAN THIS MORNING MORE INTO SOUTHEAST LOWER
MICHIGAN AS CYCLONIC FLOW INCREASES AROUND THE SYSTEM AND THE
DEFORMATION BAND TAKES ON A MORE NORTHWEST TO SOUTHEAST
ORIENTATION. THIS IS ALREADY STARTING TO TAKE SHAPE PER LATEST
RADAR IMAGERY. BAND OF HEAVIEST RAIN IS EXPECTED TO STRETCH
ROUGHLY FROM THE SAGINAW VALLEY DOWN THROUGH THE DETROIT AREA THIS
AFTERNOON BEFORE DROPPING SOUTH EARLY TONIGHT AS THE LOW CENTER
WORKS SOUTHWARD. SOME MINOR ADJUSTMENTS WERE MADE TO PRECIPITATION
PLACEMENT BASED ON RADAR TRENDS AND LATEST RUNS OF HIGHER-RES
MODELS (HRRR...NAM12...NMM)...WITH HIGHEST POPS AND QPF SHIFTED
VERY SLIGHTLY TO THE WEST AND SOUTH. BIGGEST CHANGES WERE IN THE
FORM OF HIGHER POPS OVER LENAWEE COUNTY...LOWER POPS OVER THE
THUMB...AND A MORE PRONOUNCED DRYING TREND OVER THE NORTHERN HALF
OF THE FORECAST AREA EARLY TONIGHT.
STRONGER SHOWERS AND THUNDERSTORMS HAVE ALSO STARTED TO DEVELOP
EARLY THIS AFTERNOON AS WARMING OCCURS WITH DIURNAL HEATING IN THE
LOW LEVELS AND THE UPPER LEVELS COOL IN THE PROXIMITY OF THE
DEVELOPING UPPER LOW. THIS HAS RESULTED IN A FEW HUNDRED J/KG OF
MU CAPE PER LATEST SPC ANALYSIS. STILL NOT EXPECTING SEVERE
WEATHER...BUT LOCALLY HEAVY RAINFALL IS EXPECTED.
&&
.AVIATION...ISSUED 709 AM EDT WED MAY 4 2016
STEADY STREAM OF MID LEVEL MOISTURE WILL SUSTAIN POCKETS OF SHOWERS
WITHIN A HIGH BASED CLOUD THIS MORNING. SE MICHIGAN EXPECTED RESIDE
ALONG THE EASTERN EXTENT OF THE DEEPER MOISTURE AND FORCING
ASSOCIATED WITH LOW PRESSURE TRACKING THROUGH LOWER MICHIGAN.
MBS/FNT REMAIN MORE FAVORABLY POSITIONED TO SEE A PERIOD OF
WIDESPREAD PRECIPITATION THIS AFTERNOON WITH AN ACCOMPANYING
REDUCTION IN CONDITIONS INTO MVFR...PERHAPS BRIEFLY IFR AT MBS.
OVERALL TIMING A TOUCH SLOWER NOW...BUT WILL HOLD WITH THIS GENERAL
TIMING. LESS CERTAINTY FROM PTK SOUTHWARD...BUT WITH GROWING
CONFIDENCE THAT PREVAILING CONDITIONS WILL REMAIN IN VFR AS SHOWERS
FILL IN. A WEAKLY UNSTABLE ENVIRONMENT MAY SUPPORT EMBEDDED
THUNDER...UNCERTAINTY IN BOTH TIMING AND COVERAGE PRECLUDING A
DEFINED MENTION.
FOR DTW...MINIMALLY IMPACTFUL LIGHT SHOWERS IN CEILINGS ABOVE 5000
FT FOR THE MORNING PERIOD. METRO WILL THEN RESIDE AT THE EASTERN
EDGE OF MORE ORGANIZED PRECIPITATION /AND POSSIBLE THUNDER/ EXPECTED
TO DEVELOP BY MID-LATE AFTERNOON. EXISTING DRY LOW LEVEL
ENVIRONMENT MAY PROVE A FORMIDABLE LIMITING FACTOR IN GREATER
DEVELOPMENT LOCALLY. THIS CONTINUES TO LEND SUPPORT TOWARD A MORE
OPTIMISTIC OUTLOOK ON CEILING/VISIBILITY TRENDS DURING THIS TIME.
//DTW THRESHOLD PROBABILITIES...
* LOW IN CEILINGS AT OR BELOW 5000 FT PRIOR TO 20Z...MEDIUM FROM
MID AFTERNOON INTO THE EVENING.
* LOW IN THUNDERSTORMS IMPACTING THE AREA TODAY.
&&
.PREV DISCUSSION...ISSUED 337 AM EDT WED MAY 4 2016
DISCUSSION...
IMPRESSIVE SPREAD STILL EXISTS AMONG THE GUIDANCE THIS MORNING AS
FORECAST LEAD TIME DIMINISHES TO ZERO. WATER VAPOR IMAGERY SHOWS A
POWERFUL LEAD WAVE DIGGING INTO THE MIDWEST WITH A NEARLY
EQUIVALENTLY STRONG TRAILING WAVE OVER WEST-CENTRAL WISCONSIN AT
07Z. THE TRAILING WAVE HAS BEEN POORLY RESOLVED BY MANY MEMBERS OF
THE GUIDANCE...THE RAP APPEARING TO HANDLE IT THE BEST. EVEN SO, THE
RAPID REFRESH IS STRUGGLING TO KEEP UP WITH 3-HOUR PRESSURE FALLS OF
3-5MB THIS MORNING.
EXPANDING SHOWER COVERAGE IN ADVANCE OF THE WAVE IS OCCURRING WITHIN
THE CORRIDOR OF MOISTURE TRANSPORT THAT HAS EMERGED OVER SOUTHWEST
MICHIGAN DURING THE LAST COUPLE OF HOURS. FOR NOW, THIS ACTIVITY IS
STRUGGLING TO PENETRATE THE CWA DUE TO ANTECEDENT DRY AIR EVIDENT ON
THE 00Z DTX SOUNDING. COVERAGE IS EXPECTED TO INCREASE IN SE
MICHIGAN OVER THE NEXT SEVERAL HOURS AS THE COLUMN SATURATES, LARGE
SCALE FORCING INCREASES, AND DIURNAL DESTABILIZATION GETS UNDERWAY.
THE PRIMARY FEATURE OF INTEREST, THE BAND OF RAIN WITH EMBEDDED
HEAVY SHOWERS, IS SO FAR BEHAVING AS ANTICIPATED. ITS NARROW
STRUCTURE IS ATTRIBUTABLE TO DEEP LAYER LINEAR/CONVERGENT FORCING
ALONG THE STRONG TROUGH AXIS. THE UPPER TROUGH WILL BEGIN THE
PROCESS OF CLOSING OFF LATE THIS MORNING OR EARLY THIS AFTERNOON AS
ENERGY CONTINUES TO FLOOD SOUTH INTO THE WESTERN GREAT LAKES. AS
THIS OCCURS, THE BAND WILL STALL AND PIVOT IN CYCLONIC FASHION WITH
PRECIPITATION RATES INTENSIFYING AS DEFORMATION FORCING RAMPS UP
WEST OF US-23. IN ADDITION, DIURNAL HEATING AND STEEP LAPSE RATES
WILL CONTRIBUTE TO A LOW DENSITY CAPE PROFILE CHARACTERIZED BY A FEW
HUNDRED J/KG OF POTENTIAL ENERGY. SKINNY CAPE WITHIN PERSISTENT
STRONG DEFORMATION WILL BE SUFFICIENT TO PRODUCE A SOLID HALF INCH
TO THREE QUARTERS OF RAIN OVER WESTERN AREAS. A LOCALIZED AREA -
PERHAPS JUST THE FOOTPRINT OF A COUNTY OR TWO -COULD EASILY SEE OVER
AN INCH IN THIS SETUP. MOST LIKELY AREA FOR HEAVIEST RAIN WILL BE
BETWEEN LIVINGSTON AND BAY COUNTIES WEST OF US-23/I-75. THE LACK OF
SIGNIFICANT MOISTURE (PWAT < 0.80") AND A VERY SHALLOW (< 5KFT) WARM
CLOUD LAYER WILL PUT A DEFINITE CEILING ON POTENTIAL RAINFALL
AMOUNTS SO THINGS WILL NOT GET OUT OF CONTROL.
UNCERTAINTY IN PRECIP POTENTIAL INCREASES FOR EASTERN AREAS,
INCLUDING DETROIT METRO, AS THE CONVERGENT RAINFALL BAND STALLS UPON
THE MID-LEVEL LOW CLOSING OFF. HOWEVER, LATEST RAP SIMULATIONS SHOW
RESPECTABLE CAPE OF A FEW HUNDRED J/KG ACROSS THE EAST. WILL LIKELY
SEE SOME SUBTLE RIDGING FORCED OVER THE EASTERN CWA DURING PEAK
HEATING, BUT LOW/MID-LEVEL THETA MAY BE JUST ENOUGH IN THE STEEP
LAPSE RATE ENVIRONMENT TO SERVE AS A TRIGGER FOR DISORGANIZED SHOWER
ACTIVITY DURING THE AFTERNOON. THUS, LIKELY POPS REMAIN IN PLACE IN
SPITE OF THE WESTWARD ADJUSTMENT FROM YESTERDAY MORNING`S FORECAST.
WARMING TREND INTO THE 60S THURSDAY AND LOW 70S FRIDAY AS RIDGING IS
FORCED THROUGH THE CWA DURING THE LATE WEEK PERIOD. LINGERING
CYCLONIC FLOW AND MOISTURE WILL KEEP A PARTIAL COVERAGE OF DIURNAL
CU AND POSSIBLY JUST AN ISOLATED SHOWER IN THE FORECAST THROUGH
THURSDAY. DEEP LAYER SUBSIDENCE WILL SUPPORT FULL SUN AND MUCH
WARMER TEMPS ON FRIDAY AS THE BOUNDARY LAYER TAPS INTO 850MB TEMPS
IN THE HIGH SINGLE DIGITS BY AFTERNOON.
MARINE...
MODEST NORTHERLY WINDS WILL BEGIN TO TAKE HOLD ACROSS THE CENTRAL
GREAT LAKES TODAY AS LOW PRESSURE PIVOTS THROUGH LOWER MICHIGAN.
SLIGHT INCREASE IN NORTHERLY FLOW TONIGHT INTO EARLY THURSDAY MAY
LEAD TO A BRIEF PERIOD OF GUSTS NEAR 20 KNOTS ACROSS SOUTHERN
SECTIONS OF LAKE HURON DURING THIS TIME. THE ONSHORE FLOW WILL ALSO
BRING A PERIOD OF ELEVATED WAVE CONDITIONS ALONG THE THUMB DURING
THIS TIME. HOWEVER SMALL CRAFT ADVISORY LEVEL CONDITIONS ARE
CURRENTLY NOT ANTICIPATED. HIGH PRESSURE WILL THEN BRING TRANQUIL
MARINE CONDITIONS FOR THE LATE WEEK PERIOD.
HYDROLOGY...
STRENGTHENING LOW PRESSURE WILL DROP SOUTHEAST ACROSS THE STATE
THROUGH THIS EVENING. A PERIOD OF STRONG FORCING ASSOCIATED WITH
THIS SYSTEM WILL SLIDE INTO WESTERN PORTIONS SE MICHIGAN LATE TODAY.
THIS WILL FOCUS AN AXIS OF HEAVIER RAINFALL ALONG HIGHWAY 23
CORRIDOR...WHERE RAINFALL AMOUNTS FROM ONE HALF TO THREE QUARTERS OF
AN INCH ARE EXPECTED. DECREASING RAINFALL AMOUNTS WITH EASTWARD
EXTENT...LEAVING EASTERN PORTIONS OF METRO DETROIT NORTHWARD INTO
THE THUMB WITH LESS THAN A QUARTER OF AN INCH. THE BULK OF THIS
RAINFALL WILL OCCUR DURING THE AFTERNOON AND EARLY EVENING HOURS.
RAINFALL WILL TAPER OFF QUICKLY EARLY TONIGHT WITH GENERALLY DRY
WEATHER THURSDAY AND FRIDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......HLO
AVIATION.....MR
DISCUSSION...JVC
MARINE.......MR
HYDROLOGY....MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
709 AM EDT WED MAY 4 2016
.AVIATION...
STEADY STREAM OF MID LEVEL MOISTURE WILL SUSTAIN POCKETS OF SHOWERS
WITHIN A HIGH BASED CLOUD THIS MORNING. SE MICHIGAN EXPECTED RESIDE
ALONG THE EASTERN EXTENT OF THE DEEPER MOISTURE AND FORCING
ASSOCIATED WITH LOW PRESSURE TRACKING THROUGH LOWER MICHIGAN.
MBS/FNT REMAIN MORE FAVORABLY POSITIONED TO SEE A PERIOD OF
WIDESPREAD PRECIPITATION THIS AFTERNOON WITH AN ACCOMPANYING
REDUCTION IN CONDITIONS INTO MVFR...PERHAPS BRIEFLY IFR AT MBS.
OVERALL TIMING A TOUCH SLOWER NOW...BUT WILL HOLD WITH THIS GENERAL
TIMING. LESS CERTAINTY FROM PTK SOUTHWARD...BUT WITH GROWING
CONFIDENCE THAT PREVAILING CONDITIONS WILL REMAIN IN VFR AS SHOWERS
FILL IN. A WEAKLY UNSTABLE ENVIRONMENT MAY SUPPORT EMBEDDED
THUNDER...UNCERTAINTY IN BOTH TIMING AND COVERAGE PRECLUDING A
DEFINED MENTION.
FOR DTW...MINIMALLY IMPACTFUL LIGHT SHOWERS IN CEILINGS ABOVE 5000
FT FOR THE MORNING PERIOD. METRO WILL THEN RESIDE AT THE EASTERN
EDGE OF MORE ORGANIZED PRECIPITATION /AND POSSIBLE THUNDER/ EXPECTED
TO DEVELOP BY MID-LATE AFTERNOON. EXISTING DRY LOW LEVEL ENVIRNMENT
MAY PROVE A FORMIDABLE LIMITING FACTOR IN GREATER DEVELOPMENT
LOCALLY. THIS CONTINUES TO LEND SUPPORT TOWARD A MORE OPTIMISTIC
OUTLOOK ON CEILING/VISIBILITY TRENDS DURING THIS TIME.
//DTW THRESHOLD PROBABILITIES...
* LOW IN CEILINGS AT OR BELOW 5000 FT PRIOR TO 20Z...MEDIUM FROM
MID AFTERNOON INTO THE EVENING.
* LOW IN THUNDERSTORMS IMPACTING THE AREA TODAY.
&&
.PREV DISCUSSION...ISSUED 337 AM EDT WED MAY 4 2016
DISCUSSION...
IMPRESSIVE SPREAD STILL EXISTS AMONG THE GUIDANCE THIS MORNING AS
FORECAST LEAD TIME DIMINISHES TO ZERO. WATER VAPOR IMAGERY SHOWS A
POWERFUL LEAD WAVE DIGGING INTO THE MIDWEST WITH A NEARLY
EQUIVALENTLY STRONG TRAILING WAVE OVER WEST-CENTRAL WISCONSIN AT
07Z. THE TRAILING WAVE HAS BEEN POORLY RESOLVED BY MANY MEMBERS OF
THE GUIDANCE...THE RAP APPEARING TO HANDLE IT THE BEST. EVEN SO, THE
RAPID REFRESH IS STRUGGLING TO KEEP UP WITH 3-HOUR PRESSURE FALLS OF
3-5MB THIS MORNING.
EXPANDING SHOWER COVERAGE IN ADVANCE OF THE WAVE IS OCCURRING WITHIN
THE CORRIDOR OF MOISTURE TRANSPORT THAT HAS EMERGED OVER SOUTHWEST
MICHIGAN DURING THE LAST COUPLE OF HOURS. FOR NOW, THIS ACTIVITY IS
STRUGGLING TO PENETRATE THE CWA DUE TO ANTECEDENT DRY AIR EVIDENT ON
THE 00Z DTX SOUNDING. COVERAGE IS EXPECTED TO INCREASE IN SE
MICHIGAN OVER THE NEXT SEVERAL HOURS AS THE COLUMN SATURATES, LARGE
SCALE FORCING INCREASES, AND DIURNAL DESTABILIZATION GETS UNDERWAY.
THE PRIMARY FEATURE OF INTEREST, THE BAND OF RAIN WITH EMBEDDED
HEAVY SHOWERS, IS SO FAR BEHAVING AS ANTICIPATED. ITS NARROW
STRUCTURE IS ATTRIBUTABLE TO DEEP LAYER LINEAR/CONVERGENT FORCING
ALONG THE STRONG TROUGH AXIS. THE UPPER TROUGH WILL BEGIN THE
PROCESS OF CLOSING OFF LATE THIS MORNING OR EARLY THIS AFTERNOON AS
ENERGY CONTINUES TO FLOOD SOUTH INTO THE WESTERN GREAT LAKES. AS
THIS OCCURS, THE BAND WILL STALL AND PIVOT IN CYCLONIC FASHION WITH
PRECIPITATION RATES INTENSIFYING AS DEFORMATION FORCING RAMPS UP
WEST OF US-23. IN ADDITION, DIURNAL HEATING AND STEEP LAPSE RATES
WILL CONTRIBUTE TO A LOW DENSITY CAPE PROFILE CHARACTERIZED BY A FEW
HUNDRED J/KG OF POTENTIAL ENERGY. SKINNY CAPE WITHIN PERSISTENT
STRONG DEFORMATION WILL BE SUFFICIENT TO PRODUCE A SOLID HALF INCH
TO THREE QUARTERS OF RAIN OVER WESTERN AREAS. A LOCALIZED AREA -
PERHAPS JUST THE FOOTPRINT OF A COUNTY OR TWO -COULD EASILY SEE OVER
AN INCH IN THIS SETUP. MOST LIKELY AREA FOR HEAVIEST RAIN WILL BE
BETWEEN LIVINGSTON AND BAY COUNTIES WEST OF US-23/I-75. THE LACK OF
SIGNIFICANT MOISTURE (PWAT < 0.80") AND A VERY SHALLOW (< 5KFT) WARM
CLOUD LAYER WILL PUT A DEFINITE CEILING ON POTENTIAL RAINFALL
AMOUNTS SO THINGS WILL NOT GET OUT OF CONTROL.
UNCERTAINTY IN PRECIP POTENTIAL INCREASES FOR EASTERN AREAS,
INCLUDING DETROIT METRO, AS THE CONVERGENT RAINFALL BAND STALLS UPON
THE MID-LEVEL LOW CLOSING OFF. HOWEVER, LATEST RAP SIMULATIONS SHOW
RESPECTABLE CAPE OF A FEW HUNDRED J/KG ACROSS THE EAST. WILL LIKELY
SEE SOME SUBTLE RIDGING FORCED OVER THE EASTERN CWA DURING PEAK
HEATING, BUT LOW/MID-LEVEL THETA MAY BE JUST ENOUGH IN THE STEEP
LAPSE RATE ENVIRONMENT TO SERVE AS A TRIGGER FOR DISORGANIZED SHOWER
ACTIVITY DURING THE AFTERNOON. THUS, LIKELY POPS REMAIN IN PLACE IN
SPITE OF THE WESTWARD ADJUSTMENT FROM YESTERDAY MORNING`S FORECAST.
WARMING TREND INTO THE 60S THURSDAY AND LOW 70S FRIDAY AS RIDGING IS
FORCED THROUGH THE CWA DURING THE LATE WEEK PERIOD. LINGERING
CYCLONIC FLOW AND MOISTURE WILL KEEP A PARTIAL COVERAGE OF DIURNAL
CU AND POSSIBLY JUST AN ISOLATED SHOWER IN THE FORECAST THROUGH
THURSDAY. DEEP LAYER SUBSIDENCE WILL SUPPORT FULL SUN AND MUCH
WARMER TEMPS ON FRIDAY AS THE BOUNDARY LAYER TAPS INTO 850MB TEMPS
IN THE HIGH SINGLE DIGITS BY AFTERNOON.
MARINE...
MODEST NORTHERLY WINDS WILL BEGIN TO TAKE HOLD ACROSS THE CENTRAL
GREAT LAKES TODAY AS LOW PRESSURE PIVOTS THROUGH LOWER MICHIGAN.
SLIGHT INCREASE IN NORTHERLY FLOW TONIGHT INTO EARLY THURSDAY MAY
LEAD TO A BRIEF PERIOD OF GUSTS NEAR 20 KNOTS ACROSS SOUTHERN
SECTIONS OF LAKE HURON DURING THIS TIME. THE ONSHORE FLOW WILL ALSO
BRING A PERIOD OF ELEVATED WAVE CONDITIONS ALONG THE THUMB DURING
THIS TIME. HOWEVER SMALL CRAFT ADVISORY LEVEL CONDITIONS ARE
CURRENTLY NOT ANTICIPATED. HIGH PRESSURE WILL THEN BRING TRANQUIL
MARINE CONDITIONS FOR THE LATE WEEK PERIOD.
HYDROLOGY...
STRENGTHENING LOW PRESSURE WILL DROP SOUTHEAST ACROSS THE STATE
THROUGH THIS EVENING. A PERIOD OF STRONG FORCING ASSOCIATED WITH
THIS SYSTEM WILL SLIDE INTO WESTERN PORTIONS SE MICHIGAN LATE TODAY.
THIS WILL FOCUS AN AXIS OF HEAVIER RAINFALL ALONG HIGHWAY 23
CORRIDOR...WHERE RAINFALL AMOUNTS FROM ONE HALF TO THREE QUARTERS OF
AN INCH ARE EXPECTED. DECREASING RAINFALL AMOUNTS WITH EASTWARD
EXTENT...LEAVING EASTERN PORTIONS OF METRO DETROIT NORTHWARD INTO
THE THUMB WITH LESS THAN A QUARTER OF AN INCH. THE BULK OF THIS
RAINFALL WILL OCCUR DURING THE AFTERNOON AND EARLY EVENING HOURS.
RAINFALL WILL TAPER OFF QUICKLY EARLY TONIGHT WITH GENERALLY DRY
WEATHER THURSDAY AND FRIDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
DISCUSSION...JVC
MARINE.......MR
HYDROLOGY....MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
337 AM EDT WED MAY 4 2016
.DISCUSSION...
IMPRESSIVE SPREAD STILL EXISTS AMONG THE GUIDANCE THIS MORNING AS
FORECAST LEAD TIME DIMINISHES TO ZERO. WATER VAPOR IMAGERY SHOWS A
POWERFUL LEAD WAVE DIGGING INTO THE MIDWEST WITH A NEARLY
EQUIVALENTLY STRONG TRAILING WAVE OVER WEST-CENTRAL WISCONSIN AT
07Z. THE TRAILING WAVE HAS BEEN POORLY RESOLVED BY MANY MEMBERS OF
THE GUIDANCE...THE RAP APPEARING TO HANDLE IT THE BEST. EVEN SO, THE
RAPID REFRESH IS STRUGGLING TO KEEP UP WITH 3-HOUR PRESSURE FALLS OF
3-5MB THIS MORNING.
EXPANDING SHOWER COVERAGE IN ADVANCE OF THE WAVE IS OCCURRING WITHIN
THE CORRIDOR OF MOISTURE TRANSPORT THAT HAS EMERGED OVER SOUTHWEST
MICHIGAN DURING THE LAST COUPLE OF HOURS. FOR NOW, THIS ACTIVITY IS
STRUGGLING TO PENETRATE THE CWA DUE TO ANTECEDENT DRY AIR EVIDENT ON
THE 00Z DTX SOUNDING. COVERAGE IS EXPECTED TO INCREASE IN SE
MICHIGAN OVER THE NEXT SEVERAL HOURS AS THE COLUMN SATURATES, LARGE
SCALE FORCING INCREASES, AND DIURNAL DESTABILIZATION GETS UNDERWAY.
THE PRIMARY FEATURE OF INTEREST, THE BAND OF RAIN WITH EMBEDDED
HEAVY SHOWERS, IS SO FAR BEHAVING AS ANTICIPATED. ITS NARROW
STRUCTURE IS ATTRIBUTABLE TO DEEP LAYER LINEAR/CONVERGENT FORCING
ALONG THE STRONG TROUGH AXIS. THE UPPER TROUGH WILL BEGIN THE
PROCESS OF CLOSING OFF LATE THIS MORNING OR EARLY THIS AFTERNOON AS
ENERGY CONTINUES TO FLOOD SOUTH INTO THE WESTERN GREAT LAKES. AS
THIS OCCURS, THE BAND WILL STALL AND PIVOT IN CYCLONIC FASHION WITH
PRECIPITATION RATES INTENSIFYING AS DEFORMATION FORCING RAMPS UP
WEST OF US-23. IN ADDITION, DIURNAL HEATING AND STEEP LAPSE RATES
WILL CONTRIBUTE TO A LOW DENSITY CAPE PROFILE CHARACTERIZED BY A FEW
HUNDRED J/KG OF POTENTIAL ENERGY. SKINNY CAPE WITHIN PERSISTENT
STRONG DEFORMATION WILL BE SUFFICIENT TO PRODUCE A SOLID HALF INCH
TO THREE QUARTERS OF RAIN OVER WESTERN AREAS. A LOCALIZED AREA -
PERHAPS JUST THE FOOTPRINT OF A COUNTY OR TWO -COULD EASILY SEE OVER
AN INCH IN THIS SETUP. MOST LIKELY AREA FOR HEAVIEST RAIN WILL BE
BETWEEN LIVINGSTON AND BAY COUNTIES WEST OF US-23/I-75. THE LACK OF
SIGNIFICANT MOISTURE (PWAT < 0.80") AND A VERY SHALLOW (< 5KFT) WARM
CLOUD LAYER WILL PUT A DEFINITE CEILING ON POTENTIAL RAINFALL
AMOUNTS SO THINGS WILL NOT GET OUT OF CONTROL.
UNCERTAINTY IN PRECIP POTENTIAL INCREASES FOR EASTERN AREAS,
INCLUDING DETROIT METRO, AS THE CONVERGENT RAINFALL BAND STALLS UPON
THE MID-LEVEL LOW CLOSING OFF. HOWEVER, LATEST RAP SIMULATIONS SHOW
RESPECTABLE CAPE OF A FEW HUNDRED J/KG ACROSS THE EAST. WILL LIKELY
SEE SOME SUBTLE RIDGING FORCED OVER THE EASTERN CWA DURING PEAK
HEATING, BUT LOW/MID-LEVEL THETA MAY BE JUST ENOUGH IN THE STEEP
LAPSE RATE ENVIRONMENT TO SERVE AS A TRIGGER FOR DISORGANIZED SHOWER
ACTIVITY DURING THE AFTERNOON. THUS, LIKELY POPS REMAIN IN PLACE IN
SPITE OF THE WESTWARD ADJUSTMENT FROM YESTERDAY MORNING`S FORECAST.
WARMING TREND INTO THE 60S THURSDAY AND LOW 70S FRIDAY AS RIDGING IS
FORCED THROUGH THE CWA DURING THE LATE WEEK PERIOD. LINGERING
CYCLONIC FLOW AND MOISTURE WILL KEEP A PARTIAL COVERAGE OF DIURNAL
CU AND POSSIBLY JUST AN ISOLATED SHOWER IN THE FORECAST THROUGH
THURSDAY. DEEP LAYER SUBSIDENCE WILL SUPPORT FULL SUN AND MUCH
WARMER TEMPS ON FRIDAY AS THE BOUNDARY LAYER TAPS INTO 850MB TEMPS
IN THE HIGH SINGLE DIGITS BY AFTERNOON.
&&
.MARINE...
MODEST NORTHERLY WINDS WILL BEGIN TO TAKE HOLD ACROSS THE CENTRAL
GREAT LAKES TODAY AS LOW PRESSURE PIVOTS THROUGH LOWER MICHIGAN.
SLIGHT INCREASE IN NORTHERLY FLOW TONIGHT INTO EARLY THURSDAY MAY
LEAD TO A BRIEF PERIOD OF GUSTS NEAR 20 KNOTS ACROSS SOUTHERN
SECTIONS OF LAKE HURON DURING THIS TIME. THE ONSHORE FLOW WILL ALSO
BRING A PERIOD OF ELEVATED WAVE CONDITIONS ALONG THE THUMB DURING
THIS TIME. HOWEVER SMALL CRAFT ADVISORY LEVEL CONDITIONS ARE
CURRENTLY NOT ANTICIPATED. HIGH PRESSURE WILL THEN BRING TRANQUIL
MARINE CONDITIONS FOR THE LATE WEEK PERIOD.
&&
.HYDROLOGY...
STRENGTHENING LOW PRESSURE WILL DROP SOUTHEAST ACROSS THE STATE
THROUGH THIS EVENING. A PERIOD OF STRONG FORCING ASSOCIATED WITH
THIS SYSTEM WILL SLIDE INTO WESTERN PORTIONS SE MICHIGAN LATE TODAY.
THIS WILL FOCUS AN AXIS OF HEAVIER RAINFALL ALONG HIGHWAY 23
CORRIDOR...WHERE RAINFALL AMOUNTS FROM ONE HALF TO THREE QUARTERS OF
AN INCH ARE EXPECTED. DECREASING RAINFALL AMOUNTS WITH EASTWARD
EXTENT...LEAVING EASTERN PORTIONS OF METRO DETROIT NORTHWARD INTO
THE THUMB WITH LESS THAN A QUARTER OF AN INCH. THE BULK OF THIS
RAINFALL WILL OCCUR DURING THE AFTERNOON AND EARLY EVENING HOURS.
RAINFALL WILL TAPER OFF QUICKLY EARLY TONIGHT WITH GENERALLY DRY
WEATHER THURSDAY AND FRIDAY.
&&
.AVIATION...ISSUED 1154 PM EDT TUE MAY 3 2016
A REGION OF RAIN WILL SLOWLY PUSH TOWARD THE EAST DURING THE EARLY
MORNING. MID LEVEL MOISTURE ADVECTION IN ADVANCE OF THE MAIN REGION
OF RAIN MAY TRIGGER SOME BRIEF HIGH BASED LIGHT SHOWERS PRIOR TO
DAYBREAK. RECENT MODEL GUIDANCE SUGGESTS THE MAIN REGION OF RAIN
WILL WORK INTO MBS AND FNT JUST PRIOR TO DAYBREAK. WITH THE UPPER
WAVE FORECAST TO DEVELOP INTO A CLOSED MID LEVEL LOW OVER NRN
INDIANA ON WEDNESDAY...THE AXIS OF STRONGER FORCING WILL STRUGGLE
TO PUSH MUCH FARTHER EAST THAN FNT AND PERHAPS PTK. INITIAL DRY
AIR IN THE LOW LEVELS WILL LEAD TO A RATHER GRADUAL LOWERING OF
CEILING HEIGHTS DURING THE COURSE OF THE MORNING. SOME DEGREE OF
MVFR TYPE CIGS ARE EXPECTED AT FNT AND MBS BY AFTERNOON.
DEVELOPING SFC LOW PRESSURE FORECAST TO TRACK SOUTH OF THE REGION
WED AFTERNOON WILL DRAW A LITTLE COOLER LOW LEVEL AIR INTO FNT AND
MBS...OFFERING A GOOD CHANCE OF LOW END MVFR AND/OR IFR CIGS LATE
WED AFTERNOON/EVENING. A PERSISTENT INFLUX OF LOW LEVEL DRY AIR
FARTHER EAST MAY IN FACT LEAD TO A RATHER NARROW REGION BETWEEN
IFR/MVFR CONDITIONS AND VFR CONDITIONS.
FOR DTW...RECENT RADAR IMAGERY IS SUGGESTING THE SCATTERED HIGH
BASED SHOWERS WILL IMPACT METRO DETROIT DURING AT LEAST THE FIRST
TWO TO FOUR HOURS OF THE TAF PERIOD. OTHERWISE...RECENT MODEL TRENDS
SUGGEST DRIER LOW LEVEL AIR GETTING ADVECTED INTO METRO DETROIT FROM
THE EAST ON WEDNESDAY AS THE SFC LOW DEVELOPS TO THE SOUTHWEST. THIS
MAY HOLD THE MORE WIDESPREAD RAIN AND LOWER CEILINGS WEST OF METRO
AIRPORT.
//DTW THRESHOLD PROBABILITIES...
* LOW IN CEILINGS AT OR BELOW 5000 FT THIS MORNING. MEDIUM THIS
AFTERNOON.
* LOW IN THUNDERSTORMS IMPACTING THE AREA TODAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
DISCUSSION...JVC
MARINE.......MR
HYDROLOGY....MR
AVIATION.....SC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 AM EDT WED MAY 4 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 416 PM EDT TUE MAY 3 2016
WV IMAGERY AND RAP ANALYSIS INDICATED A PROMINENT MID/UPPER LEVEL
RIDGE FROM THE RODCKIES NORTHWARD THROUGH WRN CANADA RESULTING IN
NNW FLOW FROM MANITOBA INTO THE UPPER MS VALEY AND WRN LAKES. AT THE
SFC...A COLD FRONT EXTENDED INTO NW LAKE SUPERIOR FROM LOW PRES JUST
WEST OF JAMES BAY. A VIGOROUS SHORTWAVE TROUGH INTO WRN LAKE
SUPERIOR AND ASSOCIATED 800-600 MB FGEN IN ADVANCE OF THIS FEATURE
SUPPORTED AN AREA OF SHOWERS THROUGH MOST OF UPPER MI. SOME ISOLD
TSRA HAD ALSO DEVELOPED NEAR CYQT WHERE LOW LEVEL CONV WAS STRONGEST
ALONG THE COLD FRONT.
TONIGHT...EXPECT THE SHOWERS TO BECOME MORE SCATTERED LATE THIS
AFTERNOON AND EVENING AS THE FGEN AREA SLIDES TO THE SE AND THE COLD
FRONT MOVES IN. SOME ISOLD TSRA WILL ALSO STILL BE POSSIBLE WITH THE
FRONT. CAA WILL INCREASE BEHIND THE FRONT LATE THIS EVENING INTO THE
OVERNIGHT HOURS WITH INCREASED MIXING AND GUSTIER NORTH WINDS.
EXPECT THE BEST CHANCE FOR PCPN LATE TONIGHT WHERE NRLY UPSLOPE FLOW
IS STRONGEST OVER THE N CNTRL UPPER MI. AS WET BULB ZERO HEIGHTS
DROP AFTER 06Z...SOME LIGHT SNOW MAY MIX IN WITH THE RAIN. WITH LOWS
ONLY TO AROUND 34...ANY ACCUMULATION WOULD BE CONFINED MAINLY TO
GRASSY SURFACES.
WEDNESDAY...THE MID LEVEL TROUGH WILL CONTINUE TO DEEPEN INTO IN/OH
KEEPING COLD NRLY FLOW GOING INTO UPPER MI. EXPECT ENOUGH DEEP
MOISTURE TO LINGER WITH SATURATION NEAR -8C TO -10C LAYER TO
MINIMIZE DZ CHANCES. SO...UPSLOPE SOME SN/RA IS EXPECTED TO CONTINUE
INTO N CNTRL UPPER MI IN THE MORNING WITH POTENTIAL TO TRANSITION TO
SOME DZ BY AFTERNOON AS THE 850-600 MOISTURE DEPARTS. WELL BELOW
NORMAL TEMPS WILL PREVAIL WITH HIGHS FROM AROUND 50 NORTH TO 50
SOUTH EVEN AS SUNSHINE INCREASES IN THE AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 329 PM EDT TUE MAY 3 2016
DEEP TROUGH OVER THE GREAT LAKES AND OHIO VALLEY GIVES WAY TO RISING
HEIGHTS THU INTO FRI AS RIDGE OVER THE WESTERN CONUS MOVES EAST. SFC
HIGH MOVES ACROSS UPPER GREAT LAKES WITH DRY WEATHER. BLO FREEZING
TEMPS LIKELY OVER INTERIOR WEST BENEATH RIDGE AXIS ON WED NIGHT.
ONCE THE SFC RIDGE MOVES EAST...WEAK SFC LOW OVER CANADIAN PRAIRIES
WILL EXTEND A WARM FRONT TOWARD UPPER GREAT LAKES ON FRIDAY. WILL
BEGIN TO WARM AWAY FM THE GREAT LAKES ON THU WITH READINGS INTO THE
MID TO UPR 60S INTERIOR WEST. MIN RH WILL DROP BLO 30 PCT...BUT
WINDS LOOK LIGHT. SCT-BKN MID CLOUDS IN THE MORNING SHOULD GIVE WAY
TO MOSTLY SUNNY SKIES IN THE AFTN. DEEPER MIXING AND H85 TEMPS 14-
16C WILL PUSH TEMPS WELL ABOVE NORMAL INTO THE MID 70S TO MID 80S.
DESPITE THE WARMTH...FIRE WEATHER ISSUES SHOULD BE MINIMAL AS SFC-
H85 DWPNTS WILL BE ON THE RISE SO MIN RH SHOULD BE HIGHER THAN THU
AND LIKE THU THE WINDS SHOULD BE LIGHT.
SUMMERTIME WARMTH WILL BE SHORT LIVED AS STRONGER SHORTWAVE TROUGH
CRASHES THE RIDGE OVER THE UPPER GREAT LAKES FRI NIGHT INTO SAT.
COLD FRONT MOVES THROUGH FRI NIGHT. BROKEN BAND OF SHOWERS EXPECTED
WITH THE FROPA. OUTSIDE CHANCE OF TSRA WITH DIFFLUENT FLOW ALOFT AND
WEAK ELEVATED INSTABILITY /H7-H5 LAPSE RATES CONDITIONALY UNSTABLE
AT 6.5C/KM AND MUCAPE UP TO 250 J/KG/...BUT SINCE STRONGEST PVA AND
STRONGER WINDS ALOFT REMAIN OVER NORTHERN ONTARIO DO NOT EXPECT
STRONG TSRA. BEHIND THE FRONT ON SAT...MUCH COOLER CONDITIONS BUT
MOSTLY DRY. GUSTY NNW WINDS 20-30 MPH NEAR LK SUPERIOR AND UP TO 20
MPH INLAND. IF WATER TEMPS WERE WARMER ON LK SUPERIOR SETUP WOULD BE
FAVORABLE FOR INCREASED SWIM RISK. CURRENT WATER TEMPS AROUND 40 IN
THE NEARSHORE SO NOT AN ISSUE QUITE YET.
WARMING TREND THROUGH REST OF EXTENDED /DAYTIME HIGHS 60S AND MAYBE
SLIGHTLY WARMER/ AS UPPER TROUGH MOVING FROM SOUTHWEST CONUS TO
NORTHERN PLAINS PUSHES RIDGE DOWNSTREAM OVER GREAT LAKES.
DIFFERENCES ARISE MON INTO TUE ON HOW QUICK UPPER TROUGH BRINGS SFC
LOW ACROSS THE CENTRAL TO NORTHERN PLAINS. GFS IS QUICKEST WHILE GEM
IS MORE SUPPRESSED TO THE SOUTH. ECMWF IS A COMPROMISE.
REGARDLESS...WEATHER DOES NOT APPEAR TOO HIGH IMPACT AS EVEN WITH
GFS IDEA BULK OF HIGHER INSTABILITY BOTH SFC AND ELEVATED REMAINS
TOO FAR SW TO BRING ANY STRONGER TSRA AS FAR NORTH AS UPR MICHIGAN.
CURRENT FORECAST FOR TUE SHOWS MORE CLOUDS AND SHRA/TSRA CHANCES
ATTM...BUT IF THE SLOWER IDEA WORKS OUT...DRY WEATHER WOULD HOLD
UNTIL LATE TUE AND TUE WOULD BECOME MORE OF A FIRE WEATHER ISSUE
WITH TEMPS NEAR 70 DEGREES...LOW RH VALUES AND GUSTY EAST-SOUTHEAST
WINDS AHEAD OF THE LOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 132 AM EDT WED MAY 4 2016
COLDER AIR AND LOW-LEVEL MOISTURE BEHIND A COLD FRONT WILL LEAD TO
MVFR CIGS OVERNIGHT AT KCMX AND KSAW...WHICH WILL CONTINUE INTO WED
AFTERNOON. HOWEVER...A PERIOD OF HIGH-END MVFR CIGS CANNOT BE RULED
OUT AT KSAW LATE TONIGHT INTO WED MORNING. A MIX OF SNOW AND RAIN IS
ALSO EXPECTED AT KSAW LATE TONIGHT INTO WED MORNING BUT IS NOT
EXPECTED TO BE HEAVY ENOUGH TO RESTRICT VSBY. KIWD WILL BE FARTHER
AWAY FROM THE BETTER LOW-LEVEL MOISTURE...BUT A PERIOD OF MVFR CIGS
WILL BE POSSIBLE LATE TONIGHT INTO WED MORNING. EXPECT GUSTY NORTH
WINDS AT OR ABOVE 20 KNOTS TO DEVELOP TONIGHT AND CONTINUE THROUGH
WED AFTERNOON AT BOTH KCMX AND KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 PM EDT TUE MAY 3 2016
WINDS WILL BECOME N TO NW AT AROUND 20 KNOTS LATE THIS AFTERNOON AND
EVENING BEHIND THE TROUGH/FRONT AND INCREASE TO AS HIGH AS 30 KNOTS
OVER THE EAST HALF OF LAKE SUPERIOR LATE TONIGHT INTO WEDNESDAY. A
HIGH PRESSURE RIDGE BUILDING OVER THE UPPER GREAT LAKES WILL
DIMINISH WINDS TO LESS THAN 20KT LATE WED NIGHT INTO FRIDAY. ANOTHER
TROUGH/COLD FRONT MOVING ACROSS THE REGION WILL RESULT IN NW WINDS
TO 20 KT OVER THE EAST HALF OF LAKE SUPERIOR LATE FRI NIGHT AND
SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KLUBER
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
322 PM CDT WED MAY 4 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 320 PM CDT WED MAY 4 2016
TWO CONCERNS IN THE SHORT TERM. THE FIRST IS THE THREAT OF FROST
TONIGHT WHILE THE SECOND IS WHETHER OR NOT THERE WILL BE WIDELY
SCATTERED SHOWERS ACROSS WEST CENTRAL WI ON THURSDAY.
BREEZY NORTH TO NORTHWEST WINDS CONTINUED ACROSS THE FA AT MID
AFTERNOON WITH THE REGION SANDWICHED BETWEEN HIGH PRESSURE OVER THE
EASTERN DAKOTAS AND LOW PRESSURE OVER THE LOWER GREAT LAKES.
AFTERNOON HUMIDITY WAS QUITE LOW AND IN THE 20 TO 30 PERCENT RANGE.
THE SYSTEM OF HIGH PRESSURE WILL MOVE ACROSS THE FA TONIGHT. WINDS
WILL DIMINISH QUICKLY EARLY TONIGHT WITH TEMPERATURES FALLING
PRECIPITOUSLY DUE TO THE LOW DEW POINTS. THE LOWEST TEMPERATURES ARE
EXPECTED TO BE NORTH AND EAST OF THE TWIN CITIES WITH LOWER TO
MIDDLE 30S COMMON. THE LOWER 30S ARE MAINLY CONFINED FROM RUSK
THROUGH EAU CLAIRE COUNTIES WHERE A FROST ADVISORY REMAINS IN EFFECT
LATE TONIGHT. THERE IS A CONCERN WITH THE LOW TEMPERATURE FORECAST
IN THE FACT THAT IT MAY BE TOO COLD OVER NORTHERN AND EASTERN AREAS
DUE TO INCREASING MID LEVEL CLOUDINESS LATE IN THE NIGHT.
HOWEVER...THE DAMAGE FROM THE FROST MAY BE OVER BY THE TIME THE
CLOUDS THICKEN SO THE FROST ADVISORY WAS LEFT IN PLACE.
THE INCREASE IN MID LEVEL CLOUDINESS LEADS INTO THE SECOND CONCERN
OF WHETHER OR NOT THERE WILL BE SOME SHOWERS ACROSS WEST CENTRAL WI
ON THURSDAY. THE CLOUDINESS IS IN RESPONSE TO A SHORTWAVE AND WAA
MOVING ACROSS THE AREA. SATURATION AND ADIABATIC OMEGA WAS MOST
NOTABLE OVER OUR FAR EASTERN FA THURSDAY MORNING ON THE NAM 300K
THETA SURFACE. THIS MOVES OUT OF OUR AREA BY EARLY AFTERNOON.
VARIOUS CAMS INCLUDING THE HOPRWRF-TS...NAMNEST...NSSL AND HRRR SHOW
AN AREA OF SHOWERS MOVING SOUTHWARD ACROSS THE ARROWHEAD OF MN AFTER
06Z AND PUSHING ACROSS WEST CENTRAL WI IN THE 12Z-18Z PERIOD.
IN ADDITION...THE ECMWF HAS BEEN SHOWING THIS AREA OF SHOWERS IN THE
AFOREMENTIONED LOCATIONS FOR SEVERAL RUNS NOW. SURROUNDING OFFICES
WERE NOT SOLD ON THE MODEL SOLUTIONS AND WENT WITH A SPRINKLE
FORECAST. WE USED A VARIETY OF SHORT TERM SOLUTIONS AND INTRODUCED
SOME SMALL CHANCES FOR SHOWERS THURSDAY MORNING FROM LADYSMITH
THROUGH EAU CLAIRE. LITTLE CHANGE WITH REGARDS TO HIGH TEMPERATURES
TOMORROW WITH READINGS RANGING FROM THE UPPER 60S IN EAU CLAIRE TO
THE LOWER 80S IN CANBY AND MORRIS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED MAY 4 2016
THE LONGER TERM CONCERNS REMAIN THE THUNDER CHANCES FRIDAY NIGHT
AND OVERALL DEVELOPMENT OF UPPER AIR PATTERN EARLY/INTO MIDWEEK
NEXT WEEK.
THE COLD FRONT APPEARS TO BE MOVING JUST A BIT FASTER ACCORDING
TO THE LATEST DETERMINISITIC RUNS. THE SREF AND 12Z NAM ARE THE
SLOWEST WITH THE SOUTHEAST PROGRESSION BY 00Z SAT. IT SHOULD BE
POSITIONED NEAR A KJMR-KSTC-KMOX LINE AT THAT TIME. STILL SEE A
GOOD THERMAL RIDGE AHEAD OF THE FRONT AND 85-90F LOOKS LIKE A GOOD
BET FOR MOST OF CENTRAL/SRN MN FRIDAY AFTERNOON. INSTABILITY
INCREASES AND THERE REMAINS WEAK FORCING/CONVERGENCE ALONG THE
FRONT. MODELS CONTINUE TO GENERATE AT LEAST SOME SCATTERED
CONVECTION ALONG THE FRONT AS IT DROP SOUTHEAST FRIDAY NIGHT. WE WILL
HOLD ONTO THE SMALL CHANCE POPS PRIMARILY IN THE 00Z-06Z PERIOD
AND TRAIL THEM OFF THROUGH 12Z SAT.
COOLER AIR MOVES IN FOR SATURDAY AND SUNDAY WITH DRY HIGH PRESSURE
DOMINATING THE WEATHER. THIS SHOULD PROVIDE PLEASANT WEATHER FOR
THE WISCONSIN FISHING OPENER ALONG WITH MOTHERS DAY ON SUNDAY.
THE LONG TERM MODELS DIVERGE LATER IN THE PERIOD WITH THE OVERALL
DEVELOPMENT OF THE WESTERN CONUS CUTOFF CIRCULATION. THE GFS
CARRIES MUCH OF THE SYSTEM THE SYSTEM TO THE SOUTH OF THE
STATE...WITH PERHAPS THE SOUTHERN THIRD AFFECTED MONDAY/TUESDAY.
THE ECMWF CONTINUES ITS TREND OF LIFTING A SERIES OF UPPER LOWS
OVER THE AREAS THROUGH MUCH OF NEXT WEEK. THIS WOULD PROVIDE THE
GENERALLY CLOUDIER/COOLER AND WETTER CONDITIONS FOR THE REGION.
WILL HOLD ONTO THE BLENDED MODEL POP GUIDANCE FOR NOW AND SEE IF
THE MODELS COME INTO BETTER AGREEMENT IN FUTURE RUNS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1234 PM CDT WED MAY 4 2016
TWO CONCERNS THIS CYCLE. THE FIRST IS GUSTY NORTHWEST WINDS
THROUGH LATE AFTERNOON DUE TO THE GRADIENT BETWEEN HIGH PRESSURE
OVER THE EASTERN DAKOTAS AND LOW PRESSURE OVER THE LOWER GREAT
LAKES. NW WINDS AROUND 15 KNOTS WITH GUSTS OF 20-25 KNOTS WILL BE
COMMON FROM THE TWIN CITIES ON EAST AND SOUTH THROUGH 22Z ALONG
WITH A FEW-SCT050-060. THE WINDS WILL BECOME LIGHT AND VARIABLE
THIS EVENING THEN BECOME LIGHT SSW ON THURSDAY. THE SECOND CONCERN
IS THE THREAT FOR SOME SHOWERS THURSDAY MORNING IN THE 12Z-18Z
TIME FRAME. THE GREATEST THREAT AT THIS TIME IS AT KEAU WHERE A
PROB30 GROUPS WAS USED. INDICATED VCSH AT KRNH AND KMSP.
KMSP...VFR THROUGH THE PERIOD. EXPECT THE GUSTY WINDS TO DIMINISH
TO 10 KNOTS OR LESS IN THE 23Z-24Z PERIOD. SMALL THREAT FOR
SHOWERS THURSDAY MORNING...ESPECIALLY IN THE 12Z-16Z PERIOD.
/OUTLOOK FOR KMSP/
FRI...VFR. SLGT CHC TSRA FRI EVENING. WIND SW 5-10 KTS.
SAT...VFR. WIND NE 10-15 KTS.
SUN...VFR. WIND N 5 KTS...BECOMING E.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 3 AM TO 7 AM CDT THURSDAY FOR WIZ016-027-028.
MN...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...DWE
AVIATION...RAH
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
846 PM MDT THU MAY 5 2016
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...
SENT AN UPDATE TONIGHT TO TRY AND PIECE TOGETHER THE CHANCES FOR
PRECIPITATION TONIGHT WITH HOURLY POPS AND WEATHER GRIDS. FOLLOWED
THE WETTER GFS AND HRRR SOLUTIONS BUT MUTED THEM SOMEWHAT.
THINKING THAT THUNDERSTORM CHANCES WILL DIE OFF AFTER MIDNIGHT.
NORTHWEST WINDS HAVE ALREADY BEGUN TO SET UP IN RESPONSE TO THE
APPROACHING COLD FRONT WHICH WILL PROBABLY BE THE FOCUS FOR SOME
SCATTERED RAIN SHOWERS OVERNIGHT AND TOMORROW MORNING. BMICKELSON
PREVIOUS SHORT TERM DISCUSSION...AS THE UPPER RIDGE DRIFTS
EASTWARD...SATELLITE IMAGERY IS SHOWING CLOUDINESS BEGINNING TO
ENTER THE AREA AS THE NORTHERN STREAM OF THE UPPER LOW TO THE
SOUTHWEST IS BEGINNING TO ENTER THE AREA. MODELS ARE FINALLY IN
FAIRLY CLOSE AGREEMENT REGARDING THE PLACEMENT AND TIMING OF THE
PRECIPITATION...BUT ARE A LITTLE LESS SO ON PRECIPITATION AMOUNTS.
WENT WITH A GENERAL CONSENSUS WITH MOST AREAS RECEIVING A FEW
HUNDREDTHS TO A COUPLE TENTHS OF AN INCH OF RAIN THROUGH FRIDAY.
WITH THE APPROACHING MOISTURE THIS EVENING...THERE IS A CHANCE OF
SHOWERS AND THUNDERSTORMS OVER OUR WESTERN ZONES TONIGHT AND INTO
EARLY FRIDAY MORNING. AFTER SUNRISE FRIDAY THE THUNDERSTORM
CHANCES DECREASE AND MAINLY LIGHT SHOWERS ARE EXPECTED.
BY FRIDAY AFTERNOON...MODEL AGREEMENT KEEPS MOST OF THE
PRECIPITATION SOUTH OF OUR AREA AS A NARROW RIDGE OF HIGH PRESSURE
MOVES THROUGH...ALTHOUGH SOME LIGHT SHOWERS COULD LINGER IN OUR
SOUTHERN ZONES INTO SATURDAY MORNING. THAT NARROW RIDGE KEEPS US
RELATIVELY DRY ON SUNDAY.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
BLENDED CURRENT FORECAST WITH THE 12Z MODELS. MODELS CONTINUED TO
HAVE TROUBLE WITH RESOLVING SYSTEM EARLY NEXT WEEK WITH THE ECMWF
SHOWING MORE OF AN OPEN WAVE AND THUS FASTER. THE GFS CLOSES IT
OFF AND GIVES THE CWA MORE PRECIP THROUGH THE REMAINDER OF THE
PERIOD. TFJ
PREVIOUS DISCUSSION...
AN UPPER RIDGE WILL BE OVER THE AREA SATURDAY NIGHT WITH DRY
WEATHER. THAT RIDGE WILL MOVE TO THE EAST ON SUNDAY AND AN UPPER
TROUGH WILL MOVE IN FROM THE WEST. SUNDAY WILL REMAIN DRY AS IT
LOOKS LIKE MOISTURE WILL MOVE INTO THE AREA SUNDAY NIGHT AND
MONDAY. A COLD FRONT ASSOCIATED WITH THE SYSTEM WILL MOVE THROUGH
EASTERN MONTANA ON MONDAY. ATMOSPHERE MAY BE UNSTABLE ENOUGH FOR
THUNDERSTORMS MONDAY AFTERNOON AND EVENING. WILL MENTION A SLIGHT
CHANCE FOR NOW.
THE UPPER TROUGH AND MOISTURE WILL REMAIN OVER THE AREA ON
TUESDAY. WILL MAINTAIN A CHANCE OF SHOWERS. ATMOSPHERE MAY BE
UNSTABLE ENOUGH FOR THUNDERSTORMS. WILL MENTION A SLIGHT CHANCE.
MODELS DIFFERENCES START APPEARING TUESDAY NIGHT AND WEDNESDAY AS
GFS WANTS TO MOVE UPPER TROUGH/LOW TO THE EAST AND ECMWF KEEPS AN
UPPER LOW OVER MONTANA. WILL MAINTAIN CHANCE OF SHOWERS.
NEXT THURSDAY...GFS HAS NW FLOW ALOFT WITH SHORTWAVES WHILE THE
ECMWF MOVES THE UPPER LOW TO THE DAKOTAS. WILL CONTINUE A SLIGHT
CHANCE OF SHOWERS. FORRESTER
&&
.AVIATION...
SYNOPSIS:
A SHORTWAVE TROUGH AND COLD FRONT IS EXPECTED TONIGHT.
FLIGHT CATEGORY: VFR.
WX/WIND: ISOL TO SCT SHOWERS AND THUNDERSTORMS AND MID LEVEL
CLOUDS ARE EXPECTED TONIGHT WITH THE COLD FRONT. EXPECT LIGHT
MAINLY SOUTH TO SW WINDS TO BECOME NW TO NORTH 10 TO 20 KNOTS
AFTER 06Z TONIGHT AS THE COLD FRONT MOVES THROUGH. WINDS CONTINUE
TO TURN CLOCKWISE INTO FRIDAY. TFJ/PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BUFFALO NY
737 PM EDT THU MAY 5 2016
.SYNOPSIS...
AN UPPER LEVEL LOW WILL SLOWLY SPIRAL FROM THE CAROLINAS TONIGHT TO
NEW ENGLAND SATURDAY...WITH PERIODIC CHANCES FOR SHOWERS INTO THE
WEEKEND. ANOTHER UPPER LEVEL LOW WILL APPROACH FROM THE UPPER
GREAT LAKES AND BRING ADDITIONAL RAIN SHOWERS TO THE EASTERN GREAT
LAKES REGION SATURDAY NIGHT. TEMPERATURES WILL RISE TO ABOVE
NORMAL BY SATURDAY...BEFORE A COLD FRONT CROSSES THE REGION
SATURDAY NIGHT RETURNING TEMPERATURES TO BELOW NORMAL AGAIN.
&&
.NEAR TERM /THROUGH FRIDAY/...
AN UPPER LEVEL LOW WILL REMAIN STALLED ACROSS THE MID-ATLANTIC
STATES WITH OUR REGION REMAINING IN A LIGHT AND LARGELY DRY FLOW.
SHOWERS HAVE LARGELY TAPERED OFF...WITH DRY CONDITIONS EXPECTED TO
LAST THROUGH THE NIGHT. CLOUD COVER WILL BE PATCHY...BUT MOST
PERSISTENT ACROSS SOUTHERN AND EASTERN PORTIONS OF THE CWA. EXPECT
LOW TEMPERATURES TO BE SEASONABLE...IN THE LOWER TO MID 40S.
TOMORROW AS THIS UPPER LEVEL LOW ADVANCES NORTHWARD ALONG THE
ATLANTIC COASTLINE IT WILL SEND ANOTHER SURGE OF MOISTURE BACK OVER
OUR REGION...THIS FROM THE SOUTHEAST. IT SHOULD BE A PRETTY NICE
DAY ACROSS THE NIAGARA FRONTIER AND SAINT LAWRENCE VALLEY WITH
MORNING SUNSHINE GIVING WAY TO HIGH CLOUDS IN THE AFTERNOON.
SHOWERS WILL SPREAD INTO THE REGION FROM THE SE WITH THIS UPPER
LOW...LIKELY REACHING THE SOUTHERN GENESEE VALLEY AND FINGER LAKES
REGION IN THE AFTERNOON. WILL HAVE HIGH CHANCE TO LOW LIKELY POPS
HERE...TAPERING DOWN TO SLIGHT CHANCE ALONG THE NW AREAS OF WNY
AND THE SLV.
WITH 850 HPA TEMPERATURES A FEW DEGREES WARMER THAN TODAY...A 4
TO 6C 850 HPA TEMPERATURE SHOULD RESULT IN HIGHS IN THE LOW TO MID
60S...WITH JUST A FEW LOCATIONS REMAINING IN THE UPPER 50S OVER
THE INLAND SOUTHERN TIER.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
SHOWERS SHOULD CONTINUE THROUGH FRIDAY EVENING FOR AT LEAST SOUTHERN
AND EASTERN PORTIONS OF THE AREA AS ANOTHER DISTURBANCE ROTATES
AROUND THE PERIPHERY OF THE CUT-OFF LOW...WHICH IS FORECAST TO STALL
OVER NORTHERN VIRGINIA/MARYLAND. AS THE THE LOW GRADUALLY FILLS
OVERNIGHT...CHANCES FOR SHOWERS WILL DIMINISH.
THE CUT-OFF LOW WEAKENS IN PLACE OVER THE MID ATLANTIC REGION
SATURDAY...HOWEVER WE WILL REMAIN UNDER THE INFLUENCE OF LINGERING
CYCLONIC FLOW. SO WHILE SOME BREAKS OF SUNSHINE LOOK POSSIBLE EXPECT
MUCH OF THE DAY COULD END UP MOSTLY CLOUDY. WITH THE CYCLONIC FLOW
STILL IN PLACE AND SOME RESIDUAL LOW LEVEL MOISTURE...ISOLATED TO
WIDELY SCATTERED SHOWERS CANNOT BE RULED OUT. TEMPERATURES SHOULD
REACH IN THE UPPER 60S TO LOWER 70S DEPENDING ON HOW MUCH SUNSHINE
IS REALIZED. LAKESHORE AREAS WILL BE SEVERAL DEGREES COOLER AS LAKE
BREEZE CIRCULATIONS SET UP.
THE UPPER LOW THAT HAS BEEN PLAGUING THE REGION IS EXPECTED TO OPEN
BY SATURDAY NIGHT. LASTEST GUIDANCE IS IN AGREEMENT IT WILL
CONSOLIDATED WITH A LARGE UPPER LOW THAT DEVELOPS NEAR HUDSON BAY AS
A VIGOROUS SHORT WAVE MOVES ACROSS THE GREAT LAKES REGION SATURDAY
NIGHT. AS THE SHORT WAVE ROTATES ABOUT THE UPPER LOW IT WILL MOVE
ACROSS THE NORTHEAST DRIVING A STRONG COLD FRONT ACROSS THE REGION.
A ROUND OF SHOWERS AND PERHAPS A FEW THUNDERSTORMS ARE EXPECTED
SATURDAY NIGHT INTO SUNDAY AS THIS SHORT WAVE AND COLD FRONT CROSS
THE REGION.
IN WAKE OF THE FRONT...GUSTY WEST TO NORTHWEST WINDS WILL DEVELOPED
DURING THE DAY SUNDAY. IT WILL BE NOTABLY COOLER WITH TEMPERATURES A
SOLID 10 TO 15 DEGREES COOLER THAN SATURDAY WITH MOST HIGHS
REMAINING IN THE 50S. FOR THE MOST PART...THE DAY WILL BE DRY
OUTSIDE OF LINGERING MORNING SHOWERS ACROSS THE NORTH COUNTRY AND
SOME ISOLATED DIRUNALLY DRIVEN SHOWERS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ON MONDAY THE MID LEVEL TROUGH OVER QUEBEC WILL PULL AWAY FROM THE
AREA WITH SURFACE HIGH PRESSURE BUILDING INTO THE GREAT LAKES
REGION. THIS WILL BRING A RETURN TO DRY WEATHER AND SUNSHINE TO
START THE WEEK. TEMPERATURES ALOFT WILL BEGIN TO RECOVER AS THE MID
LEVEL LOW PULLS AWAY...WITH HIGHS IN THE LOWER 60S ACROSS LOWER
ELEVATIONS AWAY FROM THE LAKESHORES.
MODEL GUIDANCE BEGINS TO DIVERGE BY MONDAY NIGHT AND TUESDAY WITH
THE HANDLING OF THE NEXT SYSTEM APPROACHING THE REGION. A MID LEVEL
CLOSED LOW WILL PROGRESS EASTWARD THROUGH THE CENTRAL PLAINS THIS
PERIOD...WITH A BROAD REGION OF WARM ADVECTION AND DEEPER MOISTURE
SPREADING NORTHEAST THROUGH THE OHIO VALLEY. THE ECMWF AND CANADIAN
GEM ARE FASTER AND FARTHER EAST WITH THIS SYSTEM...BRINGING WARM
FRONTAL SHOWERS INTO OUR REGION BY LATER MONDAY NIGHT AND TUESDAY.
THE GFS IS SLOWER AND FARTHER WEST WITH THIS SYSTEM...KEEPING OUR
REGION DRY THROUGH TUESDAY. THE LATEST 12Z GEFS SHOW A VARIETY OF
SOLUTIONS WITH SOME MEMBERS FASTER AND SIMILAR TO THE ECMWF/GEM
SOLUTION. WITH THIS IN MIND...HAVE INCREASED POPS TO MID RANGE
CHANCE FROM LATER MONDAY NIGHT INTO TUESDAY.
WEDNESDAY INTO THURSDAY THE FRONTAL ZONE IS FORECAST TO STALL FROM
THE OHIO VALLEY INTO THE NORTHERN MID ATLANTIC...WITH ONE OR TWO
WAVES OF LOW PRESSURE RUNNING ALONG THE BOUNDARY. THIS WILL KEEP
UNSETTLED WEATHER ACROSS OUR REGION WITH A CHANCE OF SOME RAIN BOTH
DAYS...WITH THE GREATEST CHANCES FOR STEADIER SHOWERS ACROSS THE
SOUTHERN HALF OF THE AREA GIVEN THE PLACEMENT OF THE FRONTAL ZONE.
TEMPERATURES WILL REMAIN CLOSE TO SEASONAL NORMS THROUGH THE MIDDLE
OF THE WEEK WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 40S.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AT 23Z...THERE WAS WIDESPREAD VFR CONDITIONS ACROSS THE
AREA...WITH THE MOST PERSISTENT (BUT STILL VFR) CLOUD COVER ACROSS
SE PORTIONS OF THE AREA. THERE IS MODERATE CONFIDENCE THAT VFR
CONDITIONS WILL CONTINUE OVERNIGHT. THE HRRR DOES DEVELOP FOG AND
STRATUS...HOWEVER THERE IS LITTLE SUPPORT FROM OTHER GUIDANCE AND
SATELLITE IMAGERY SHOWS IT IS ALREADY OVERDONE. ALL TAFS ARE VFR
TONIGHT...WITH A SMALL CHANCE OF FOG DEVELOPING IN THE 08Z TO 13Z
TIMEFRAME.
EXPECT VFR CONDITIONS TO CONTINUE ON FRIDAY...WITH HIGH CLOUDS
LOWERING AND THICKENING FROM THE SE LATE IN THE AFTERNOON. ANY
SHOWERS SHOULD HOLD OFF UNTIL JUST AFTER 00Z SATURDAY.
OUTLOOK...
FRIDAY NIGHT...VFR/MVFR WITH SHOWERS LIKELY...MAINLY ACROSS
INTERIOR PORTIONS OF THE SOUTHERN TIER AND FINGER LAKES.
SATURDAY...VFR.
SATURDAY NIGHT...SHOWERS WITH A CHANCE OF THUNDERSTORMS. IFR/MVFR
SUNDAY...MAINLY VFR WITH A CHANCE OF MORNING SHOWERS EAST OF
KROC/KDSV.
MONDAY...VFR.
MONDAY NIGHT AND TUESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
THROUGH SATURDAY A RELATIVELY WEAK PRESSURE GRADIENT WILL OCCUR
ACROSS THE LOWER LAKES REGION. THIS WILL RESULT IN LIGHT TO MODEST
WINDS PREDOMINATING...ALONG WITH CORRESPONDINGLY MINIMAL WAVES.
A COLD FRONT WILL CROSS THE LOWER LAKES SATURDAY NIGHT...AND WAVES
ON LAKE ONTARIO WILL LIKELY NEAR SMALL CRAFT ADVISORY THRESHOLDS
LATER SATURDAY NIGHT AND THROUGH SUNDAY. THE WESTERLY FLOW WILL
YIELD LOWER WAVE HEIGHTS ON LAKE ERIE...SUCH THAT WAVES MAY REMAIN
BELOW SCA THROUGH THE WEEKEND.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...APFFEL/THOMAS
SHORT TERM...TMA
LONG TERM...HITCHCOCK
AVIATION...APFFEL
MARINE...THOMAS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
651 PM EDT WED MAY 4 2016
.SYNOPSIS...
A COLD FRONT WILL SINK SLOWLY SOUTH THROUGH THE AREA TONIGHT.
A POTENT UPPER LEVEL LOW WILL DROP SOUTH WITH A SERIES OF SURFACE
LOWS CROSSING THE AREA THROUGH EARLY SATURDAY. A WEAK COLD FRONT
WILL APPROACH FROM THE NORTH SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 645 PM WED...EARLIER CONVECTION THAT FIRED ON SEA BRZ IS
DIMINISHING. WILL KEEP SLIGHT POP IN CORRIDOR JUST INLAND FROM
CST CPL MORE HOURS THEN MAINLY DRY OVERNIGHT...WITH POSS SOME
SHRA MOVING INTO NW TIER VERY LATE. AS NNE WINDS DEVELOP IN WAKE
OF FRONT EXPECT SOME LOW CLOUDS AND PERHAPS SOME FOG TO SPREAD SW
OVER THE REGION LATER TONIGHT. OVERNIGHT LOWS WILL BE IN THE MID
TO UPPER 50S INLAND AND THE UPPER 50S TO AROUND 60 OUTER BANKS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
AS OF 330 PM WED...THE UPPER LOW WILL MOVE SOUTHEAST OVER THE
AREA THURSDAY. VERY COLD TEMPERATURES ALOFT /PERHAPS MONTHLY-DAILY
RECORDS FOR TEMPS ALOFT/ AND SURFACE HEATING WILL LEAD TO STEEP
MID LEVEL LAPSE RATES AND MODEST INSTABILITY. THIS IN COMBINATION
WITH DEEP CYCLONIC FLOW WILL LEAD TO THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS. WAS TEMPTED TO GO WITH LIKELY POPS FOR THE
ENTIRE AREA BUT FOR NOW WILL KEEP LIKELY OVER THE NW THIRD OF THE
REGION WITH HIGH CHANCE POPS ELSEWHERE. SMALL HAIL WILL BE
POSSIBLE IN THE STRONGEST CELLS DUE TO THE COLD TEMPS ALOFT. HIGHS
THURSDAY WILL BE BELOW NORMAL WITH READINGS ONLY IN THE MID 60S
OUTER BANKS AND UPPER 6OS TO LOWER 70S INLAND.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...AN OMEGA BLOCK TYPE PATTERN WILL CONTINUE
THROUGH SATURDAY AS AN UPPER CLOSED LOW DROPS SOUTH INTO THE MID-
ATLANTIC REGION THROUGH FRIDAY, EVENTUALLY SHIFTING OUT TO SEA BY
LATE SATURDAY.
THURSDAY NIGHT THROUGH SATURDAY: A SERIES OF SHORTWAVES WILL RIDE
THE APPROACHING UPPER CLOSED LOW SUPPLYING A ROUND OR TWO OF
PRECIPITATION ACROSS THE AREA. THE FIRST SFC LOW WILL DROP SOUTH
THROUGH THE REGION THURSDAY NIGHT INTO EARLY FRIDAY. THIS WILL
YIELD CHC SHOWERS ACROSS THE REGION, ESPECIALLY TO THE NORTH WHERE
THE BEST LIFT IS REALIZED. ANOTHER WEAKER SHORTWAVE WILL CROSS THE
NORTHERN TIER EARLY SATURDAY WITH A SCHC SHOWERS DURING THIS TIME.
THE ATMOSPHERE WILL BE DRYING RAPIDLY, SO FEEL THE SHOWER ACTIVITY
SHOULD DWINDLE RAPIDLY THROUGH THE DAY SATURDAY FROM WEST TO EAST.
GIVEN WEST WINDS, CLOUD COVER AND SOME SHOWER ACTIVITY, TEMPERATURE
WILL STRUGGLE TO REACH 70 ON FRIDAY. THE FLOW BECOMES MORE NWLY
ALLOWING SUBSIDENCE SATURDAY. THIS IN ADDITION TO LESS CLOUD
COVER/SHOWER ACTIVITY WOULD SUGGEST TEMPERATURES SHOULD REBOUND TO
THE LOW 70S INLAND AND UPPER 60S ALONG THE OBX.
SUNDAY THROUGH WEDNESDAY: RETURN FLOW WILL DEVELOP BRIEFLY JUST
AHEAD OF A FRONT THAT IS PROGGED TO CROSS LATE SUNDAY. THE FRONT
WILL BECOME STALLED ACROSS THE AREA SUNDAY NIGHT INTO MONDAY WITH
LITTLE IN THE WAY OF MOISTURE ASSOCIATED WITH IT. THE FRONT
EVENTUALLY WASHES OUT MONDAY WITH RETURN FLOW DEVELOPING TUESDAY
INTO WEDNESDAY AHEAD OF THE NEXT SYSTEM. FEEL THE CHANCES OF
SHOWERS/THUNDERSTORMS WILL INCREASE WEDNESDAY AS BETTER LIFT AND
MOISTURE MOVES INTO THE REGION AHEAD OF THE FRONT. TEMPERATURES
WILL SLOWLY INCREASE THROUGH THIS TIME PERIOD, PERHAPS DROPPING A
DEGREE OR TWO MONDAY GIVEN THE FRONT BISECTING EASTERN NC. HIGH
TEMPERATURES WILL BE IN THE LOW 80S INLAND TO MID 70S ALONG THE
COAST FOR BOTH SUNDAY AND MONDAY. TEMPS REALLY RAMP UP BY MID WEEK
AS WARM RETURN FLOW INCREASES. HIGHS IN THE MID 80S INLAND TO MID
70S ALONG THE OBX. LOW TEMPS INCREASING THROUGH THE WEEK AS WELL,
LOW TO MID 60S.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY AFTERNOON/...
AS OF 645 PM WED...VFR THRU THE EVENING WITH SCT CLOUD...ISOLD
CONVECTION SHLD STAY E OF TAF SITES EARLY EVENING. AFTER 06Z WENT
CLOSE TO HRRR MODEL WITH IFR STRATUS SPREADING SW OVER ERN
NC...COULD ALSO BE SOME FOG AS LOW LVLS WILL BE SATURATED. THIS
STRATUS AND FOG WILL CONT THRU ABOUT 12Z THEN SLOWLY LIFT TO MVFR
AND EVENTUALLY MAINLY VFR THU. VERY COLD TEMPS ALOFT WILL LEAD TO
NUMEROUS SHRA AND A FEW TSRA DEVELOPING OVER REGION LATER WHICH
COULD LEAD TO OCNL SUB VFR.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...WITH A SERIES OF SFC LOWS CROSSING THE
AREA THROUGH SATURDAY, EXPECT SHOWER ACTIVITY TO BE OFF AND ON AT
THE TAF SITES WITH VARIABLE WINDS. THE BEST CHANCE FOR RAIN WILL
BE THURSDAY NIGHT INTO EARLY FRIDAY. POSSIBLY SCHC SHOWERS EARLY
SATURDAY AS AN UPPER LEVEL LOW MOVES OUT TO SEA. GIVEN THE LOW
LEVEL MOISTURE IN PLACE, FRIDAY AND ESPECIALLY SATURDAY MORNING WE
COULD SEE STRATUS/FOG DEVELOP. CONDITIONS IMPROVE THROUGH MONDAY
AS DRIER AIR WORKS ITS WAY INTO THE AREA. RETURN FLOW INCREASES
SUNDAY AHEAD OF A BACKDOOR FRONT WHICH WILL STALL ACROSS EASTERN
NC AND BECOME WASHED OUT. DO NOT EXPECT PRECIPITATION WITH THIS
FROPA.
&&
.MARINE...
SHORT TERM /THROUGH THURSDAY/...
AS OF 645 PM WED...NO CHANGES WITH FRONT OVER NRN TIER EXPECTED
TO PUSH S OVERNIGHT.
PREV DISC...WINDS ARE EXPECTED TO BE 10 TO 15 KT THROUGH
THURSDAY. A COLD FRONT WAS BECOMING STATIONARY FROM JUST SOUTH OF
OREGON INLET SOUTHWEST TO JUST WEST OF THE CRYSTAL COAST. AHEAD OF
THE FRONT SW FLOW IS 10 TO 15 KT WHILE BEHIND THE BOUNDARY WINDS
ARE NORTH AROUND 10 KT. SEAS ARE RUNNING 2 TO 4 FT. EXPECT THE
NORTHERLY FLOW TO SPREAD WITH THE FRONTAL PASSAGE LATE TONIGHT
BECOME NE 10 TO 15 KT NORTH OF CAPE LOOKOUT FROM TONIGHT THROUGH
THURSDAY. SOUTH OF CAPE LOOKOUT THE GRADIENT WILL BE WEAKER BEHIND
THE FRONT AND EXPECT NORTH TO NORTHEAST FLOW 10 KT OR LESS LATE
TONIGHT INTO THURSDAY. SEAS SHOULD CONTINUE 2 TO 4 FT THROUGH THE
PERIOD.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...A SERIES OF SURFACE LOWS/FRONTS WILL CROSS
THE COASTAL WATERS AS A POTENT UPPER LEVEL LOW PIVOTS THROUGH THE
REGION THURSDAY NIGHT THROUGH SATURDAY. THIS WILL MEAN VARIABLE
WINDS AROUND 10-15KTS AND SEAS AROUND 3 TO 5 FEET THROUGH MUCH OF
THE FIRST HALF OF THE PERIOD. HIGH PRESSURE WILL BUILD IN BRIEFLY,
JUST AHEAD OF A FRONT THAT WILL CROSS SUNDAY/SUNDAY NIGHT, BECOMING
WASHED OUT ACROSS THE SOUTHERN WATERS MONDAY. GIVEN THIS PATTERN,
EXPECT LIGHT AND VARIABLE WINDS AND SEAS 2 TO 3 FEET LATE SUNDAY
THROUGH MONDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JME
NEAR TERM...RF/JME
SHORT TERM...JME
LONG TERM...LEP
AVIATION...RF/LEP
MARINE...RF/JME/LEP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
943 PM CDT THU MAY 5 2016
.UPDATE...
ISSUED AT 943 PM CDT THU MAY 5 2016
MOST OF THE CUMULUS AND ISOLATED...HIGH-BASED SHOWERS /AND A LONE
STORM THAT OCCURRED IN WILLIAMS COUNTY EARLIER/ ARE DIMINISHING
WITH THE ONSET OF NOCTURNAL COOLING AND STABILIZATION. THAT IS IN
LINE WITH OUR LATE AFTERNOON FORECAST UPDATE. THE MAIN QUESTION
GOING FORWARD WILL BE WHAT /IF ANY/ SHOWER POTENTIAL EXISTS OVER-
NIGHT. RECENT OPERATIONAL HRRR SIMULATIONS CONTINUE TO BE TOO
AGGRESSIVE WITH CONVECTIVE DEVELOPMENT COMPARED TO REALITY...AND
THE 18 UTC GFS AND 00 UTC NAM ARE AT ODDS OVER SHOWER POTENTIAL.
THAT PROVIDED LOW ENOUGH CONFIDENCE FOR US TO KEEP A DRY FORECAST
GOING OVERNIGHT...THOUGH THAT WILL NEED TO BE RE-EVALUATED LATER.
THE ONE CHANGE WE DID MAKE WITH THIS UPDATE WAS TO INCREASE LOWS
BY 2-4 F IN MOST AREAS BASED ON MID-EVENING TEMPERATURE TRENDS.
FINALLY...ONE OTHER ISSUE THAT WE WILL NEED TO CONTEND WITH FOR
LATER FORECAST RELEASES IS HOW THICK SMOKE FROM CANADIAN FIRES MAY
BE FRIDAY. OBSERVATIONS IN SASKATCHEWAN HAVE SHOWN VISIBILITIES
AS LOW AS 4SM FOR SEVERAL HOURS BEHIND THE COLD FRONT THAT WILL
CROSS THE AREA. THUS...IT/S POSSIBLE THICKER LOW-LEVEL SMOKE MAY
IMPACT PARTS OF WESTERN AND CENTRAL ND LATE TONIGHT AND FRIDAY.
AT THE VERY LEAST IT SEEMS REASONABLE TO BELIEVE THE SMOKE WILL BE
SENSIBLE VIA SMELL FRIDAY.
UPDATE ISSUED AT 755 PM CDT THU MAY 5 2016
WE WILL LET THE RED FLAG WARNING EXPIRE AS SCHEDULED AT 8 PM CDT
/01 UTC/...AS WINDS IN EAST CENTRAL ND HAVE DIMINISHED TO AROUND
10 MPH. HUMIDITIES ARE AT OR ABOVE 20 PERCENT AS OF 0050 UTC AND
THEY WILL CONTINUE A SLOW RISE WITH THE ONSET OF DIURNAL COOLING.
UPDATE ISSUED AT 551 PM CDT THU MAY 5 2016
WE HAVE ADDED A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM TO THE
FORECAST THROUGH MID EVENING IN NORTHWEST ND. A HIGH-BASED SHOWER
DEVELOPED NORTHWEST OF WILLISTON NEAR 2230 UTC...AND EVEN THOUGH
THE ENTLN TOTAL LIGHTNING PLOT HAS NOT YET SHOWN ANY IN-CLOUD OR
CLOUD-TO-GROUND STRIKES...THE STEEP LAPSE RATES AND WEAK MLCAPE
/UP TO 250 J/KG PER THE SPC MESOANALYSIS/ IN THAT AREA SUGGEST A
RUMBLE OR TWO OF THUNDER IS POSSIBLE. VISIBLE SATELLITE IMAGERY
THROUGH 2245 UTC SHOWS CUMULUS ALL ALONG A WEAK SURFACE PRESSURE
TROUGH EXTENDING FROM SOUTHEAST SASKATCHEWAN INTO EASTERN MT SO IT
IS PLAUSIBLE MORE THAN JUST THAT INITIAL SHOWER MAY FORM. THAT
BEING SAID...RECENT HRRR RUNS ARE LIKELY OVERDONE WITH EXPECTED
DEVELOPMENT BASED ON THAT MODEL/S RECENT AND LONGER-TERM BIASES.
OTHERWISE...WE ARE CONTINUING THE RED FLAG WARNING IN EAST CENTRAL
ND FOR NOW GIVEN LATE-AFTERNOON OBSERVATIONS AND ONGOING FIRES.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 235 PM CDT THU MAY 5 2016
THE MAIN IMPACTS IN THE SHORT TERM ARE CRITICAL FIRE CONDITIONS
TODAY AND A COLD FRONT TOMORROW.
AN UPPER LEVEL RIDGE...COMBINED WITH A SURFACE TROUGH AND
SOUTHWESTERLY MIXING WINDS...HAVE ALLOWED TEMPERATURES THIS
AFTERNOON TO RISE RAPIDLY INTO THE 80S AND LOW 90S. THESE WARM
TEMPERATURES HAVE FURTHER EXACERBATED DRY BOUNDARY LAYER
CONDITIONS. WITH VERY DRY AIR MIXING DOWN RELATIVE HUMIDITY VALUES
HAVE PLUMMETED INTO THE TEENS AND LOW 20S. WIND SPEEDS HAVE BEEN A
BIT BREEZY ACROSS THE JAMES VALLEY. THIS IS WHAT PROMPTED THE
ISSUANCE OF THE RED FLAG WARNING. WIND SPEEDS AROUND 20
MPH...COMBINED WITH HUMIDITY 20 PERCENT OR LESS AND DRY FUELS IS
PRODUCING CRITICAL FIRE CONDITIONS ACROSS THE JAMES VALLEY.
A COLD FRONT WILL SWEEP THROUGH TONIGHT INTO FRIDAY MORNING. WINDS
WILL SHIFT OUT OF THE NORTH BETWEEN 20 AND 30 MPH. TOMORROW
AFTERNOON MINIMUM RELATIVE HUMIDITY AROUND 20 PERCENT IS EXPECTED
IN NORTHWEST AND PORTIONS OF NORTH CENTRAL NORTH DAKOTA BY LATE
AFTERNOON. HOWEVER...BY THIS TIME THE STRONGEST WINDS SHOULD HAVE
PASSED TO THE SOUTH. THEREFORE...THESE AREAS MAY ESCAPE CRITICAL
FIRE CONDITIONS. MODELS CONTINUE TO INDICATE A MAINLY DRY FRONTAL
PASSAGE...WITH A FEW ISOLATED SHOWERS POSSIBLE. HOWEVER...WITH A
PERSISTANT DRY BOUNDARY LAYER...THE LIKELIHOOD OF ANY
PRECIPITATION ACTUALLY REACHING THE GROUND IS RATHER MINIMAL.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 235 PM CDT THU MAY 5 2016
COOLER AIR WILL SETTLE INTO THE AREA THIS WEEKEND IN THE WAKE OF
FRIDAYS COLD FRONT. HOWEVER... PLEASANT TEMPERATURES ARE STILL
EXPECTED WITH HIGHS MAINLY IN THE 70S. DRY CONDITIONS WILL REMAIN.
CHANGES APPEAR ON THE HORIZON FOR THE START THE WORK WEEK AS
AN UPPER LOW CURRENTLY OFF THE CALIFORNIA COAST DEEPENS OVER THE
FOUR CORNERS REGION THIS WEEKEND AND LIFTS INTO THE PLAINS ON
MONDAY...BRINGING CHANCES FOR RAIN AND THUNDERSTORMS.
CHANCES FOR RAIN AND THUNDERSTORMS WILL LINGER OVER THE AREA
THROUGH THE WEEK AS THE GFS AND ECMWF HAVE THE LOW REMAINING
NEARBY THROUGH FRIDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 943 PM CDT THU MAY 5 2016
VFR CONDITIONS ARE FORECAST TONIGHT AND FRIDAY...BUT THERE IS A
LOW PROBABILITY OF SUB-VFR SMOKE AFFECTING PARTS OF THE AREA. THE
MAIN AVIATION WEATHER ISSUE WILL BE A COLD FRONTAL PASSAGE LATE
TONIGHT AND FRIDAY MORNING...WHICH WILL SHIFT WINDS TO THE NORTH.
NORTHERLY WIND GUSTS TO AROUND 30 KT WILL OCCUR FRIDAY ACROSS ALL
OF WESTERN AND CENTRAL ND.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
755 PM CDT THU MAY 5 2016
.UPDATE...
ISSUED AT 755 PM CDT THU MAY 5 2016
WE WILL LET THE RED FLAG WARNING EXPIRE AS SCHEDULED AT 8 PM CDT
/01 UTC/...AS WINDS IN EAST CENTRAL ND HAVE DIMINISHED TO AROUND
10 MPH. HUMIDITIES ARE AT OR ABOVE 20 PERCENT AS OF 0050 UTC AND
THEY WILL CONTINUE A SLOW RISE WITH THE ONSET OF DIURNAL COOLING.
UPDATE ISSUED AT 551 PM CDT THU MAY 5 2016
WE HAVE ADDED A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM TO THE
FORECAST THROUGH MID EVENING IN NORTHWEST ND. A HIGH-BASED SHOWER
DEVELOPED NORTHWEST OF WILLISTON NEAR 2230 UTC...AND EVEN THOUGH
THE ENTLN TOTAL LIGHTNING PLOT HAS NOT YET SHOWN ANY IN-CLOUD OR
CLOUD-TO-GROUND STRIKES...THE STEEP LAPSE RATES AND WEAK MLCAPE
/UP TO 250 J/KG PER THE SPC MESOANALYSIS/ IN THAT AREA SUGGEST A
RUMBLE OR TWO OF THUNDER IS POSSIBLE. VISIBLE SATELLITE IMAGERY
THROUGH 2245 UTC SHOWS CUMULUS ALL ALONG A WEAK SURFACE PRESSURE
TROUGH EXTENDING FROM SOUTHEAST SASKATCHEWAN INTO EASTERN MT SO IT
IS PLAUSIBLE MORE THAN JUST THAT INITIAL SHOWER MAY FORM. THAT
BEING SAID...RECENT HRRR RUNS ARE LIKELY OVERDONE WITH EXPECTED
DEVELOPMENT BASED ON THAT MODEL/S RECENT AND LONGER-TERM BIASES.
OTHERWISE...WE ARE CONTINUING THE RED FLAG WARNING IN EAST CENTRAL
ND FOR NOW GIVEN LATE-AFTERNOON OBSERVATIONS AND ONGOING FIRES.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 235 PM CDT THU MAY 5 2016
THE MAIN IMPACTS IN THE SHORT TERM ARE CRITICAL FIRE CONDITIONS
TODAY AND A COLD FRONT TOMORROW.
AN UPPER LEVEL RIDGE...COMBINED WITH A SURFACE TROUGH AND
SOUTHWESTERLY MIXING WINDS...HAVE ALLOWED TEMPERATURES THIS
AFTERNOON TO RISE RAPIDLY INTO THE 80S AND LOW 90S. THESE WARM
TEMPERATURES HAVE FURTHER EXACERBATED DRY BOUNDARY LAYER
CONDITIONS. WITH VERY DRY AIR MIXING DOWN RELATIVE HUMIDITY VALUES
HAVE PLUMMETED INTO THE TEENS AND LOW 20S. WIND SPEEDS HAVE BEEN A
BIT BREEZY ACROSS THE JAMES VALLEY. THIS IS WHAT PROMPTED THE
ISSUANCE OF THE RED FLAG WARNING. WIND SPEEDS AROUND 20
MPH...COMBINED WITH HUMIDITY 20 PERCENT OR LESS AND DRY FUELS IS
PRODUCING CRITICAL FIRE CONDITIONS ACROSS THE JAMES VALLEY.
A COLD FRONT WILL SWEEP THROUGH TONIGHT INTO FRIDAY MORNING. WINDS
WILL SHIFT OUT OF THE NORTH BETWEEN 20 AND 30 MPH. TOMORROW
AFTERNOON MINIMUM RELATIVE HUMIDITY AROUND 20 PERCENT IS EXPECTED
IN NORTHWEST AND PORTIONS OF NORTH CENTRAL NORTH DAKOTA BY LATE
AFTERNOON. HOWEVER...BY THIS TIME THE STRONGEST WINDS SHOULD HAVE
PASSED TO THE SOUTH. THEREFORE...THESE AREAS MAY ESCAPE CRITICAL
FIRE CONDITIONS. MODELS CONTINUE TO INDICATE A MAINLY DRY FRONTAL
PASSAGE...WITH A FEW ISOLATED SHOWERS POSSIBLE. HOWEVER...WITH A
PERSISTANT DRY BOUNDARY LAYER...THE LIKELIHOOD OF ANY
PRECIPITATION ACTUALLY REACHING THE GROUND IS RATHER MINIMAL.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 235 PM CDT THU MAY 5 2016
COOLER AIR WILL SETTLE INTO THE AREA THIS WEEKEND IN THE WAKE OF
FRIDAYS COLD FRONT. HOWEVER... PLEASANT TEMPERATURES ARE STILL
EXPECTED WITH HIGHS MAINLY IN THE 70S. DRY CONDITIONS WILL REMAIN.
CHANGES APPEAR ON THE HORIZON FOR THE START THE WORK WEEK AS
AN UPPER LOW CURRENTLY OFF THE CALIFORNIA COAST DEEPENS OVER THE
FOUR CORNERS REGION THIS WEEKEND AND LIFTS INTO THE PLAINS ON
MONDAY...BRINGING CHANCES FOR RAIN AND THUNDERSTORMS.
CHANCES FOR RAIN AND THUNDERSTORMS WILL LINGER OVER THE AREA
THROUGH THE WEEK AS THE GFS AND ECMWF HAVE THE LOW REMAINING
NEARBY THROUGH FRIDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 551 PM CDT THU MAY 5 2016
VFR CONDITIONS WILL CONTINUE TONIGHT AND FRIDAY. ISOLATED SHOWERS
OR THUNDERSTORMS ARE POSSIBLE IN NORTHWEST ND THIS EVENING. THE
MAIN AVIATION WEATHER ISSUE WILL BE A COLD FRONTAL PASSAGE LATE
TONIGHT AND FRIDAY MORNING...WHICH WILL SHIFT WINDS TO THE NORTH.
NORTHERLY WIND GUSTS TO AROUND 30 KT WILL OCCUR FRIDAY ACROSS ALL
OF WESTERN AND CENTRAL ND.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...CJS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
859 PM PDT THU MAY 5 2016
.SHORT TERM...A UPPER LOW CENTERED ALONG THE CENTRAL CALIFORNIA
COAST IS BRINGING WRAP AROUND MOISTURE INTO THE AREA. THE FORECAST
REMAINS ON TRACK WITH THIS LOW GRADUALLY SHIFTING INLAND FRIDAY
AND BRINGING NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS TO THE AREA.
SCATTERED SHOWERS ARE OVER THE AREA THIS EVENING. THUNDERSTORMS
HAVE DIMINISHED. HOWEVER...ADDITIONAL SHORTWAVE ACTIVITY IS
EXPECTED TO MOVE INTO THE AREA TONIGHT FROM THE SOUTH. THIS WILL
BRING ADDITIONAL CHANCES FOR THUNDERSTORMS TONIGHT. THE CURRENT
HIGH RESOLUTION HRRR INDICATES THE BEST POTENTIAL FOR
THUNDERSTORMS TONIGHT WILL BE IN THE MODOC...LAKE AND EASTERN
SISKIYOU COUNTY AREAS. STORM MOTION HAS BEEN RELATIVELY SLOW
AROUND 5 MPH THIS EVENING WILL PICK UP SLIGHTLY TONIGHT INTO
FRIDAY. SIGNIFICANT MOISTURE IS EXPECTED WITH STORMS INTO FRIDAY.
ALSO ON FRIDAY AS ADDITIONAL SHORTWAVE ENERGY MOVE INTO THE AREA
AND CAPE AND INSTABILITY INCREASE, EXPECT A SLIGHT CHANCE FOR
STORMS TO BECOME SEVERE. THE MAIN CONCERN WITH SEVERE STORMS IS
THE POTENTIAL FOR LARGE HAIL AND STRONG WINDS AS WELL AS LOCALIZED
FLOODING.
&&
.AVIATION...FOR THE 06/00Z TAF CYCLE...THE MAIN CONCERN THROUGH
FRIDAY EVENING WILL BE THUNDERSTORMS. THUNDERSTORMS ARE LIKELY TO BE
MORE NUMEROUS AND MORE LIKELY TO BE STRONG ON FRIDAY AFTERNOON AND
EVENING. THESE THUNDERSTORMS WILL BE SLOW MOVING AND PRODUCE
MODERATE TO HEAVY RAIN AND THEY MAY PRODUCE GUSTY OUTFLOW WINDS, AND
HAIL. THE BEST CHANCE THIS EVENING WILL BE OVER THE SOUTHERN OREGON
CASCADE FOOTHILLS...CASCADES AND WESTERN AND CENTRAL SISKIYOU COUNTY
WITH A SECONDARY FOCUS OVER MODOC AND LAKE COUNTIES. THUNDERSTORMS
ON FRIDAY ARE EXPECTED TO BE MOST NUMEROUS EAST OF THE CASCADES
ALTHOUGH ISOLATED STORMS MAY DEVELOP IN SOUTHWEST OREGON AND
WESTERN SISKIYOU COUNTY.
THERE WILL BE A MIX OF MVFR AND VFR CIGS OVERNIGHT WITH MOUNTAIN
OBSCURATIONS POSSIBLE IN SHOWERS AND THUNDERSTORMS. CONDITIONS WILL
IMPROVE TO WIDESPREAD VFR DURING FRIDAY MORNING BUT SHOWERS AND
THUNDERSTORMS DEVELOPING LATE MORNING INTO THE EVENING WILL ONCE
AGAIN CREATE AREAS OF MVFR WITH POTENTIALLY HAZARDOUS CONDITIONS.
-DW
&&
.MARINE...UPDATED 430 PM PDT THU 5 MAY 2016...OFFSHORE HIGH
PRESSURE AND INLAND LOW PRESSURE WILL PRODUCE PERSISTENT GUSTY
NORTHERLY WINDS AND STEEP TO VERY STEEP SEAS THROUGH FRIDAY EVENING.
THE STRONGEST WINDS AND HIGHEST SEAS WILL OCCUR OVER THE OUTER
WATERS SOUTH OF CAPE BLANCO. WINDS AND SEAS WILL REACH A PEAK ON
FRIDAY AFTERNOON...THEN GUSTY NORTH WINDS WILL CONTINUE AND SEAS
ARE LIKELY TO REMAIN STEEP TO VERY STEEP THROUGH THE WEEKEND. AS A
RESULT...A GALE WATCH HAS BEEN FOR THE OUTER WATERS SOUTH OF CAPE
BLANCO FROM LATE SATURDAY MORNING THROUGH SUNDAY EVENING.
CONFIDENCE IS MODERATE AS THE MAJORITY BUT NOT ALL OF THE MODELS
HAVE TRENDED SLIGHTLY STRONGER WITH WEEKEND WINDS...ESPECIALLY ON
SUNDAY. WINDS AND SEAS WILL BEGIN TO TREND WEAKER ON MONDAY AND
ARE EXPECTED TO DIMINISH INTO WEDNESDAY. -DW/CC
&&
.PREV DISCUSSION... /ISSUED 254 PM PDT THU MAY 5 2016/
DISCUSSION...THIS AFTERNOON THROUGH FRIDAY NIGHT...WATER VAPOR
IMAGERY IS SHOWING AN UPPER LEVEL LOW PRESSURE SYSTEM OFF THE
CENTRAL CALIFORNIA COAST THIS AFTERNOON. A STRONG BLOCKING PATTERN
DOWNSTREAM OF THIS SYSTEM IS KEEPING IT FROM MOVING MUCH. HOWEVER,
IT WILL CONTINUE TO SLOWLY EDGE EASTWARD OVER THE NEXT 24
HOURS...THEN MOVE INTO SOUTHERN NEVADA BY FRIDAY EVENING. DEEP
MID-UPPER LEVEL SOUTHERLY FLOW IN ADVANCE OF THIS SYSTEM BROUGHT
VERY MOIST, UNSTABLE AIR INTO NORTHERN CALIFORNIA AND SOUTHERN
OREGON YESTERDAY INTO THIS MORNING, WHICH CONTRIBUTED TO PLENTY OF
SHOWERS AND THUNDERSTORMS OVER THE AREA. MULTIPLE SHORT WAVE
DISTURBANCE WILL CONTINUE TO ROTATE AROUND THIS UPPER LOW AND MOVE
ACROSS THE AREA, PRODUCING MORE SHOWERS AND THUNDERSTORMS.
THE MID-UPPER FLOW ACROSS THE AREA IS IN THE PROCESS OF SHIFTING
AND WILL BECOME ALMOST DUE EAST BY FRIDAY. AS A RESULT, THE FLOW
ALOFT IS MUCH WEAKER TODAY THAN IT WAS YESTERDAY AND STORM
MOTIONS THIS AFTERNOON/EVENING WILL BE MUCH SLOWER. RAINFALL RATES
OF 0.50-1.00/HOUR ARE POSSIBLE IN SOME OF THE LONGER-LIVED CELLS,
WHICH COULD RESULT IN HIGHER THAN USUAL RUNOFF. FOR THIS REASON,
WE HAVE ISSUED A FLASH FLOOD WATCH WITH THE POTENTIAL FOR VERY
HEAVY RAINFALL IN PORTIONS OF SOUTHERN SISKIYOU COUNTY THIS
AFTERNOON THROUGH FRIDAY EVENING. THE FLASH FLOOD THREAT ALSO
EXISTS EASTWARD INTO PORTIONS OF MODOC, EASTERN KLAMATH AND LAKE
COUNTIES, BUT EXPECT THE BEST CHANCE FOR FLASH FLOODING THERE TO
BE THIS EVENING AS ACTIVITY FROM NW NEVADA ARRIVES...AND THEN
AGAIN FRIDAY AS MODELS PEG THAT AREA TO BE HIT WITH MUCH HIGHER
QPF. WE SHOULD SEE ACTIVITY WANE FOR A WHILE TONIGHT DUE TO THE
DIURNAL DROP OFF IN INSTABILITY.
ON FRIDAY, THE STORM PREDICTION CENTER HAS PORTIONS OF THE AREA,
MOSTLY FROM AROUND KLAMATH FALLS EASTWARD, IN A MARGINAL RISK FOR
SEVERE THUNDERSTORMS. MODELS ARE SHOWING SUFFICIENT INSTABILITY
TO SUPPORT SUSTAINED CELLS WITH CAPE OF 750-1500 J/KG AND VERY
STEEP MID-LEVEL LAPSE RATES (7-8C/KM). WE HAVE ADDED GUSTY WINDS
AND HAIL TO THE GRIDDED FORECASTS TO ACCOUNT FOR THIS POTENTIAL.
EVEN THOUGH STORM MOTIONS SHOULD BE A BIT FASTER FRIDAY, THE
HEAVY RAINFALL THREAT PERSISTS IN THE AREAS UNDER THE FLASH FLOOD
WATCH. SPILDE
SATURDAY THROUGH THURSDAY...THE UPPER LOW WILL SLOWLY MOVE TOWARDS
THE DESERT SOUTHWEST ON SATURDAY. IN THE MORNING THE MODELS SHOW
LINGERING WRAP AROUND MOISTURE IN NORTHERN CAL AND SOUTHEAST LAKE
AND KLAMATH COUNTIES WITH THE BEST CHANCE FOR RAIN IN SOUTHEAST
MODOC COUNTY. NONE OF THE MODELS ARE SHOWING MUCH IF ANY INSTABILITY
SATURDAY MORNING, SO WE WON`T MENTION ANY THUNDER. HOWEVER WE`LL
STILL KEEP A SLIGHT CHANCE IN THE AFTERNOON. THE UPPER LOW WILL
CONTINUE TO SLOWLY MOVE INTO THE FOUR CORNERS SUNDAY MORNING AND AN
UPPER RIDGE WILL NOSE IN FROM THE WEST, BUT THEN WILL RETREAT
WESTWARD SUNDAY AFTERNOON AS A SHORTWAVE MOVES SOUTHEAST INTO
EASTERN WASHINGTON. AT THE SURFACE A WEAK FRONT WILL MOVE THROUGH
THE NORTHWEST PART OF THE REGION SUNDAY MORNING INCREASING THE
ONSHORE FLOW. THE MARINE LATER COULD THICKEN ENOUGH FOR PATCHY
DRIZZLE AT THE COAST, OTHERWISE IT WILL REMAIN DRY. ANOTHER
SHORTWAVE WILL MOVE INTO EASTERN WASHINGTON AND NORTHEAST OREGON ON
MONDAY, BUT THE TRACK IT`S TAKING IS NOT FAVORABLE FOR
PRECIPITATION, SO WE`LL KEEP IT DRY. AN UPPER RIDGE WILL BUILD OFF
THE COAST TUESDAY WITH A THERMAL TROUGH DEVELOPING AT THE COAST. THE
MODELS DIFFER WITH THE DETAILS AFTER TUESDAY, BUT THE PATTERN
REMAINS FAVORABLE FOR CONTINUED DRY AND WARM CONDITIONS.
-PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR ORZ030-031.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT FRIDAY
FOR ORZ022.
CA...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR CAZ080>085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM PDT FRIDAY FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT FRIDAY
FOR PZZ350-356-370.
GALE WARNING UNTIL 11 PM PDT FRIDAY FOR PZZ356-376.
GALE WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING FOR
PZZ376.
$$
CC/CC/CC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
147 AM EDT WED MAY 4 2016
.SYNOPSIS...
AN UPPER LOW WILL DROP INTO THE OHIO VALLEY AND LINGER AROUND
THE MID-ATLANTIC FOR REST OF THE WEEK. THIS WILL RESULT IN AN
UNSETTLED WEATHER PATTERN WITH PLENTY OF OPPORTUNITIES FOR MUCH
NEEDED RAINFALL ACROSS CENTRAL PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
DEEP EASTERLY FLOW INTO PA PERSISTS BETWEEN COASTAL CAROLINA SFC
LOW AND SOUTHEAST CANADA SFC HIGH CIRCULATIONS. UPPER LEVEL SHEAR
AXES CONTINUE TO ROTATE OVER PA IN THE SOUTHWEST FLOW ALOFT AROUND
NRN GLAKS UPPER LOW. THIS WAS RESULTING IN A DAMP EVENING
THROUGHOUT WITH ISOLATED TO SCATTERED SHOWER ACTIVITY EARLIER
THIS EVENING...AND AN INCREASE IN LOW CLOUDS...DRIZZLE AND SPRITZY
SHOWERS ELSEWHERE ACROSS CENTRAL PA AS THE NIGHT WEARS ON.
ANOTHER UPPER SHEAR AXIS SLOWLY SWINGING INTO THE EASTERN GLAKS
AND WESTERN PA WILL KEEP SLGT CHC TO CHC POPS GOING OVERNIGHT BUT
DO NOT EXPECT ANY SIGNIFICANT PRECIPITATION. HRRR KEEPS MOST
NUMEROUS AND PERSISTENT SHOWERS ACROSS THE SOUTH AND SOUTHEAST
WHERE DEEP LAYER MOISTURE IS IN EXCESS OF 0.8"...AND DEEPER MARINE
FLOW PERSISTS. LOW CLOUDS WILL REMAIN AND EXPAND ACROSS THE AREA
OVERNIGHT. AFOREMENTIONED LIGHT SHOWERS AND AREAS OF DZ CAN BE
EXPECTED OVER MOST AREAS THROUGH SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
UPPER LOW OVER CENTRAL CANADA WILL SLIDE INTO THE UPPER OH VLY AND
KEEP IT UNSETTLED THROUGH THE PERIOD. POPS ON WED REFLECT THE
NORMAL OUTCOME OF AN UPPER LOW OVER OH/WV. SCT SHRA...WITH THE
HIGHER /LOW LIKELY/ POPS SLIDE FROM E-W AS THE MORE DRIZZLY STUFF
IS JOINED BY DIURNAL CONVECTION OVER THE WRN MTNS. MAXES SHOULD BE
ABOUT 5-10F UNDER NORMALS DUE TO LOTS OF CLOUDS AND PROXIMITY OF
THE UPPER LOW TO OUR WEST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
MODELS IN DECENT AGREEMENT FOR A LARGE TROUGH OVER EASTERN U.S.
TO BECOME DOMINATED BY A CLOSED UPPER LOW DROPPING SOUTH ACROSS
THE GREAT LAKES AND CURLING EASTWARD TO BE LOCATED OVER E NORTH
CAROLINA BY THU EVE AND DELMARVA ON FRI. SHOWERY PATTERN IN STORE
FOR SURE OVER THIS PERIOD...WITH HEAVIEST PRECIP ON THU LOCATED
OVER W PA /CLOSER TO UPPER LOW/ WITH PRECIP SHIFTING EASTWARD ON
FRI AS IT CONSOLIDATES NEAR SFC LOW PRES OFF THE MID ATLANTIC
COAST.
THERE LOOKS TO BE A BRIEF BREAK IN SHOWER ACTIVITY ON SATURDAY
ALONG WITH A MODEST SPIKE IN TEMPERATURES BEFORE A COLD FRONT
SWEEPS SEWD LATER SATURDAY INTO EARLY SUNDAY AS THE PERSISTENT
UPPER LOW GRADUALLY UNWINDS.
BEHIND THE FRONT...PROGRESSIVE UPPER TROUGH SLIDES THROUGH
BRINGING A SHOT OF COOLER AIR FOR SUN/MON BEFORE WHAT LOOKS LIKE
COULD BE A PRETTY DECENT WARMUP AS RIDGING FINALLY ARRIVES.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
SOME PATCHY LIGHT RAIN AT UNV EARLIER...BUT CENTRAL AREAS NOT BAD
NOW. STILL SOME RAIN ACROSS THE FAR EAST...MAINLY SE. SKIES CLEAR
TO THE WEST AT SITES LIKE JST...BUT BFD HAS DENSE FOG.
EXPECT SOME IMPROVEMENT BY LATE MORNING ACROSS MUCH OF THE
AREA...AS WE WILL BE BETWEEN THE COASTAL SYSTEM AND THE COLD FRONT
TO THE WEST...BUT EASTERN AREAS MAY STAY IFR AND MVFR FOR MOST OF
THE DAY.
SHOWERS AND RAIN BECOME MORE WIDESPREAD WED NIGHT.
SOME ADJUSTMENTS MADE TO THE 06Z TAFS.
OUTLOOK...
THU-FRI...OCNL SHOWERS/RESTRICTIONS POSSIBLE.
SAT...NO SIG WX EXPECTED.
SUN...SCATTERED SHOWERS/RESTRICTIONS POSSIBLE...ESPECIALLY WEST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DEVOIR
SHORT TERM...DANGELO
LONG TERM...RXR/STEINBUGL
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1022 PM EDT THU MAY 5 2016
.SYNOPSIS...
UNSEASONABLY COOL AIR WILL CONTINUE TO FILTER IN FROM THE NORTHWEST
IN THE WAKE OF A COLD FRONT. THE WEATHER WILL REMAIN UNSETTLED AS A
DEEP UPPER LOW CENTER MOVES ACROSS THE CAROLINAS TONIGHT AND AWAY TO
THE NORTHEAST ON FRIDAY. ANOTHER FRONT IS EXPECTED TO STALL JUST TO
OUR NORTH ON SATURDAY AND SUNDAY. THE FRONT SHOULD LIFT BACK TO THE
NORTH ON MONDAY...AS HIGH PRESSURE OFF THE SOUTHEAST COAST EXPANDS
AND WARM SOUTHERLY FLOW RETURNS.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1015 PM EDT...ABUNDANT MOISTURE MOVING SOUTHWARD ALONG THE
SPINE OF THE MOUNTAINS IS ENCOUNTERING WET BULB PROFILES JUST COLD
ENOUGH ABOVE ABOUT 4000 FEET TO CHANGE THE PREDOMINANT PRECIPITATION
TYPE OVER TO SNOW. ALTHOUGH THERE ARE MODEL HINTS OF SLIGHT WARMING
OVERNIGHT...IF ALL OR MOST OF THE IMPENDING QPF IS PREDOMINATELY
SNOW AT THE HIGHER ELEVATIONS...ENOUGH ACCUMULATION SHOULD DEVELOP
FOR SLIPPERY ROADWAYS AND ASSOCIATED IMPACTS TO MANIFEST THEMSELVES.
A WINTER WEATHER ADVISORY HAS BEEN POSTED FOR AVERY AND MITCHELL
COUNTIES ABOVE 3500 FEET AT THIS POINT. THE ELEVATION DEPENDENCE
WILL BE STRONG...WITH MAINLY RAIN BELOW 3500 FEET...ABOUT AN INCH AT
3500 FEET RANGING UP TO SIX INCHES ABOVE 5000 FEET.
OTHERWISE...WATER VAPOR IMAGERY AND RAP 500 MB HEIGHTS CONTINUE TO
INDICATE THAT THE 546 DM LOW CENTER HAS MOVED EAST OF THE CLT METRO
AREA. MOISTURE AND SPOKES OF 500 MB VORTICITY CONTINUE TO ROTATE
SOUTH ACROSS THE FORECAST AREA AROUND THE BACK SIDE OF THE LOW
PRESSURE SYSTEM. THIS WILL LEAD TO FAIRLY HIGH COVERAGE OF LIGHT
RAIN/SHOWERS ACROSS THE NORTHERN TIER...WITH ELEVATIONS ABOVE ABOUT
4000 FEET COLD ENOUGH FOR SNOW AT TIMES IN THE NORTHERN MOUNTAINS.
SOME WARMING IS POSSIBLE OVERNIGHT. THE SHOWER COVERAGE WILL BE MUCH
SPOTTIER IN SOUTHERN SECTIONS WITH MAINLY PERIODS OF CLOUDS. THE LOW
WILL MOVE TOWARD THE CAROLINA COAST OVERNIGHT INTO FRIDAY...AND THE
BEST Q VECTOR CONVERGENCE WILL BE TO OUR EAST. THE SETUP WILL BE
SOMEWHAT SIMILAR ON FRIDAY...AS THE LOW REMAINS OVER THE
MID-ATLANTIC COAST. LAPSE RATES WILL BE SLIGHTLY POORER WITH THE
BETTER COLD AIR OFF TO THE EAST...BUT TEMPS/DEWPTS REBOUND BY 5-7
DEGREES...AND THESE SUGGEST SOME INSTABILITY WILL REDEVELOP. CHANCES
OVERALL ARE LESSER WITH MODEL QPF BEING LESS WIDESPREAD. BREEZY TO
WINDY CONDITIONS WILL RESULT WITH DEEP MIXING.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 225 PM THURSDAY...ONE MORE POCKET OF COLD AIR ROTATES AROUND
THE UPPER LOW AND ACROSS THE AREA FRIDAY NIGHT BEFORE WARMER MID
LEVEL AIR MOVES IN ON SATURDAY. THIS WILL COMBINE WITH THE LINGERING
LOW LEVEL MOISTURE ACROSS THE MOUNTAINS TO KEEP ISOLATED TO
SCATTERED SHOWERS THERE DURING THE EVENING BEFORE ENDING BY
MIDNIGHT. A WEAK WARM FRONT TRAILING FROM A SURFACE LOW OVER THE
GREAT LAKES WILL BRUSH THE MOUNTAINS ON SATURDAY CREATING THE
POTENTIAL FOR ISOLATED SHOWERS. FINALLY...A BACK DOOR COLD FRONT
DROPS INTO THE AREA BY SUNDAY AS THE GREAT LAKES LOW MOVES EAST.
SOME WEAK SHORT WAVE ENERGY WILL CROSS THE AREA SATURDAY NIGHT AND
SUNDAY EVEN AS HEIGHTS RISE BETWEEN THE DEPARTING UPPER LOW AND A
RIDGE DEVELOPING OVER THE CENTRAL CONUS. BEST CHANCE FOR CONVECTION
WILL BE THE NORTHERN NC MOUNTAINS...WITH ISOLATED CONVECTION
POSSIBLE ACROSS THE I-40 CORRIDOR. TEMPS REBOUND TO NEAR NORMAL
LEVELS ON SATURDAY THEN RISE TO NEARLY 10 DEGREES ABOVE NORMAL ON
SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 245PM THURSDAY...THE EXTENDED PERIOD BEGINS SUNDAY NIGHT WITH
A STALLED FRONTAL BOUNDARY DRAPED W TO E ACROSS THE REGION
UNDERNEATH FAIRLY ZONAL FLOW ALOFT. THE BOUNDARY WILL RETREAT NORTH
AS A WARM FRONT AS SUBTROPICAL HIGH PRESSURE OVER THE SARGASSO SEA
INDUCES WARM SOUTHERLY FLOW ACROSS THE REGION BEGINNING MONDAY
AFTERNOON AND PERSISTING THROUGH AT LEAST WEDNESDAY. THE RETURN FLOW
WILL ALLOW TEMPERATURES TO QUICKLY REBOUND TO GENERALLY 5-10 DEGREES
ABOVE NORMAL THROUGH MID TO LATE WEEK. DEWPOINTS WILL GRADUALLY
RETURN TO THE UPPER 50S AND LOWER 60S DURING THIS TIME AS WELL AND
WITH THE INCREASING DIURNAL INSTABILITY...THERE IS A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY. THE ECMWF REMAINS LESS
OPTIMISTIC ABOUT COVERAGE THROUGH MID-WEEK WHILE THE GFS MAINTAINS
SCATTERED TO WIDESPREAD COVERAGE EACH AFTERNOON. THIS APPEARS
LARGELY TO BE THE RESULT OF STRONGER PERTURBATIONS IN THE WSW FLOW
ALOFT ENHANCING OVERALL FORCING IN THE GFS COMPARED TO THE FAIRLY
BENIGN ECMWF SOLUTION. THE FORECAST THEREFORE REFLECTS A BLEND OF
THE GUIDANCE AS THE PATTERN CERTAINLY WARRANTS SLIGHT CHANCE
COVERAGE EAST AND CHANCE COVERAGE WEST.
AN OPPORTUNITY EXISTS FOR MORE WIDESPREAD COVERAGE OF SHOWERS AND
STORMS WEDNESDAY EVENING INTO FRIDAY AS ANOTHER CLOSED LOW DROPS
INTO THE UPPER MIDWEST AND GREAT LAKES REGIONS AND A FEW LOBES OF
VORTICITY ROTATE AROUND THE BASE OF THE LOW ACROSS THE OH AND TN
VALLEYS AND INTO VIRGINIA AND THE CAROLINAS. HOWEVER...GIVEN THE
SOMEWHAT ANOMALOUS NATURE OF THIS PATTERN...AGAIN THE GUIDANCE
DIFFERS ON THE EXACT PLACEMENT AND EVOLUTION OF THE UPPER-LEVEL
FLOW. WHILE POPS INCREASE SLIGHTLY INTO LATE WEEK IN RESPONSE TO THE
ANTICIPATED BETTER FORCING ALOFT...THERE IS TOO MUCH UNCERTAINTY TO
WARRANT MORE AGGRESSIVE COVERAGE ATTM. FOR NOW...THESE FEATURES DO
LITTLE TO CHANGE THE ABOVE NORMAL TEMPERATURES WE EXPECT THROUGH THE
END OF NEXT WEEK.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AT KCLT...OCCASIONAL SHOWERS CONTINUE TO PIVOT SOUTHWARD TOWARD THE
AIRFIELD AROUND THE BACK SIDE OF THE UPPER LEVEL LOW PRESSURE
SYSTEM. DAYTIME INSTABILITY HAS WEAKENED ENOUGH THAT ANY ADDITIONAL
SHOWERS WILL LIKELY NOT CONTAIN SMALL HAIL. MAINLY VFR CIGS ARE
EXPECTED...BUT MVFR CIGS COULD APPROACH FROM THE NORTH IN THE BETTER
LOW LEVEL MOISTURE OVERNIGHT. ALTHOUGH MIXING IS NOT QUITE AS
DEEP...GUSTY NORTH WINDS WILL CONTINUE FOR A FEW HOURS INTO THE
OVERNIGHT. SHRA CHANCES WILL STEADILY DIMINISH OVERNIGHT INTO FRIDAY
MORNING...BUT LAPSE RATES WILL REMAIN SUFFICIENT FOR PROB30 CHANCES
TO RETURN FOR FRIDAY AFTERNOON. DEEP MIXING WILL PERMIT GUSTY
CONDITIONS ONCE AGAIN...WITH PEAK GUSTS 20 TO 30 KT POSSIBLE AS THE
PRESSURE GRADIENT TIGHTENS A BIT.
ELSEWHERE...THE NORTHERN TIER FROM KAVL TO KHKY WILL SEE THE BEST
CHANCES OF MOISTURE AND SHRA WRAPPING SOUTHWARD TOWARD THE
AIRFIELDS. MVFR CIGS LOOK LIKELY AS THE RAIN CONTINUES TO FALL...BUT
WITH MUCH LESS CHANCE OF SHRA AND LOWERING CIGS FARTHER SOUTH AT THE
SC TAF SITES. GUSTY CONDITIONS WILL ABATE OVERNIGHT EAST OF THE
MOUNTAINS BUT CONTINUE AT KAVL. DEEP MIXING WILL PERMIT GUSTS OF 20
TO 30 KT...POSSIBLY 35 KT AT KAVL...ON FRIDAY. ANOTHER ROUND OF
SCATTERED SHOWERS IS LIKELY THROUGH FRIDAY AFTERNOON AS STEEP LAPSE
RATES ALOFT PERSIST.
OUTLOOK...PROFILES WILL GRADUALLY DRY FRIDAY NIGHT INTO SATURDAY. A
COLD FRONT WILL APPROACH FROM THE NORTH THROUGH SUNDAY...WITH
ASSOCIATED PRECIPITATION POSSIBLY APPROACHING KAVL TO KHKY BEFORE
THE FRONT STALLS. WARMING CONDITIONS WITH A RETURN TO SW FLOW ARE
EXPECTED THROUGH EARLY NEXT WEEK.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-00Z
KCLT MED 67% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 71% MED 62% HIGH 100% HIGH 100%
KHKY LOW 56% 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 SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WINTER WEATHER ADVISORY UNTIL NOON EDT FRIDAY FOR NCZ033-050.
SC...NONE.
&&
$$
SYNOPSIS...HG/JMP
NEAR TERM...HG
SHORT TERM...RWH
LONG TERM...JMP
AVIATION...HG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
805 PM EDT THU MAY 5 2016
.SYNOPSIS...
UNSEASONABLY COOL AIR WILL CONTINUE TO FILTER IN FROM THE NORTHWEST
IN THE WAKE OF A COLD FRONT. THE WEATHER WILL REMAIN UNSETTLED AS A
DEEP UPPER LOW CENTER MOVES ACROSS THE CAROLINAS TONIGHT AND AWAY TO
THE NORTHEAST ON FRIDAY. ANOTHER FRONT IS EXPECTED TO STALL JUST TO
OUR NORTH ON SATURDAY AND SUNDAY. THE FRONT SHOULD LIFT BACK TO THE
NORTH ON MONDAY...AS HIGH PRESSURE OFF THE SOUTHEAST COAST EXPANDS
AND WARM SOUTHERLY FLOW RETURNS.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 745 PM EDT...WATER VAPOR IMAGERY AND RAP 500 MB HEIGHTS
INDICATE THAT THE 546 DM LOW CENTER HAS MOVED EAST OF THE CLT METRO
AREA. MOISTURE AND SPOKES OF 500 MB VORTICITY CONTINUE TO ROTATE
SOUTH ACROSS THE FORECAST AREA AROUND THE BACK SIDE OF THE LOW
PRESSURE SYSTEM. THIS WILL LEAD TO FAIRLY HIGH COVERAGE OF LIGHT
RAIN/SHOWERS ACROSS THE NORTHERN TIER...WITH ELEVATIONS ABOVE 4500
FEET COLD ENOUGH FOR SNOW AT TIMES IN THE NORTHERN MOUNTAINS. MOST
OF THE HIGHER MOUNTAIN VALLEYS WILL EXHIBIT WET BULB PROFILES ABOVE
FREEZING IN THE LOWEST 1500 TO 2000 FEET...SO MOSTLY RAIN IS
EXPECTED THERE. STILL...AN SPS HAS BEEN ISSUED FOR 1 TO 2 INCHES OF
SNOW POSSIBLE ABOVE 5000 FEET WHICH WILL LEAD TO SLIPPERY ROAD
CONDITIONS WITH TEMPS CURRENTLY 30 TO 32 DEGREES.
OTHERWISE...SHOWER COVERAGE WILL BE MUCH SPOTTIER IN SOUTHERN
SECTIONS WITH MAINLY PERIODS OF CLOUDS AND CONTINUED BREEZY
CONDITIONS. THE LOW WILL MOVE TOWARD THE CAROLINA COAST OVERNIGHT
INTO FRIDAY...AND THE BEST Q VECTOR CONVERGENCE WILL BE TO OUR EAST.
THE SETUP WILL BE SOMEWHAT SIMILAR ON FRIDAY...AS THE LOW REMAINS
OVER THE MID-ATLANTIC COAST. LAPSE RATES WILL BE SLIGHTLY POORER
WITH THE BETTER COLD AIR OFF TO THE EAST...BUT TEMPS/DEWPTS REBOUND
BY 5-7 DEGREES...AND THESE SUGGEST SOME INSTABILITY STILL WILL
DEVELOP. CHANCES OVERALL ARE LESSER WITH MODEL QPF BEING LESS
WIDESPREAD. BREEZY TO WINDY CONDITIONS WILL RESULT WITH DEEP MIXING.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 225 PM THURSDAY...ONE MORE POCKET OF COLD AIR ROTATES AROUND
THE UPPER LOW AND ACROSS THE AREA FRIDAY NIGHT BEFORE WARMER MID
LEVEL AIR MOVES IN ON SATURDAY. THIS WILL COMBINE WITH THE LINGERING
LOW LEVEL MOISTURE ACROSS THE MOUNTAINS TO KEEP ISOLATED TO
SCATTERED SHOWERS THERE DURING THE EVENING BEFORE ENDING BY
MIDNIGHT. A WEAK WARM FRONT TRAILING FROM A SURFACE LOW OVER THE
GREAT LAKES WILL BRUSH THE MOUNTAINS ON SATURDAY CREATING THE
POTENTIAL FOR ISOLATED SHOWERS. FINALLY...A BACK DOOR COLD FRONT
DROPS INTO THE AREA BY SUNDAY AS THE GREAT LAKES LOW MOVES EAST.
SOME WEAK SHORT WAVE ENERGY WILL CROSS THE AREA SATURDAY NIGHT AND
SUNDAY EVEN AS HEIGHTS RISE BETWEEN THE DEPARTING UPPER LOW AND A
RIDGE DEVELOPING OVER THE CENTRAL CONUS. BEST CHANCE FOR CONVECTION
WILL BE THE NORTHERN NC MOUNTAINS...WITH ISOLATED CONVECTION
POSSIBLE ACROSS THE I-40 CORRIDOR. TEMPS REBOUND TO NEAR NORMAL
LEVELS ON SATURDAY THEN RISE TO NEARLY 10 DEGREES ABOVE NORMAL ON
SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 245PM THURSDAY...THE EXTENDED PERIOD BEGINS SUNDAY NIGHT WITH
A STALLED FRONTAL BOUNDARY DRAPED W TO E ACROSS THE REGION
UNDERNEATH FAIRLY ZONAL FLOW ALOFT. THE BOUNDARY WILL RETREAT NORTH
AS A WARM FRONT AS SUBTROPICAL HIGH PRESSURE OVER THE SARGASSO SEA
INDUCES WARM SOUTHERLY FLOW ACROSS THE REGION BEGINNING MONDAY
AFTERNOON AND PERSISTING THROUGH AT LEAST WEDNESDAY. THE RETURN FLOW
WILL ALLOW TEMPERATURES TO QUICKLY REBOUND TO GENERALLY 5-10 DEGREES
ABOVE NORMAL THROUGH MID TO LATE WEEK. DEWPOINTS WILL GRADUALLY
RETURN TO THE UPPER 50S AND LOWER 60S DURING THIS TIME AS WELL AND
WITH THE INCREASING DIURNAL INSTABILITY...THERE IS A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY. THE ECMWF REMAINS LESS
OPTIMISTIC ABOUT COVERAGE THROUGH MID-WEEK WHILE THE GFS MAINTAINS
SCATTERED TO WIDESPREAD COVERAGE EACH AFTERNOON. THIS APPEARS
LARGELY TO BE THE RESULT OF STRONGER PERTURBATIONS IN THE WSW FLOW
ALOFT ENHANCING OVERALL FORCING IN THE GFS COMPARED TO THE FAIRLY
BENIGN ECMWF SOLUTION. THE FORECAST THEREFORE REFLECTS A BLEND OF
THE GUIDANCE AS THE PATTERN CERTAINLY WARRANTS SLIGHT CHANCE
COVERAGE EAST AND CHANCE COVERAGE WEST.
AN OPPORTUNITY EXISTS FOR MORE WIDESPREAD COVERAGE OF SHOWERS AND
STORMS WEDNESDAY EVENING INTO FRIDAY AS ANOTHER CLOSED LOW DROPS
INTO THE UPPER MIDWEST AND GREAT LAKES REGIONS AND A FEW LOBES OF
VORTICITY ROTATE AROUND THE BASE OF THE LOW ACROSS THE OH AND TN
VALLEYS AND INTO VIRGINIA AND THE CAROLINAS. HOWEVER...GIVEN THE
SOMEWHAT ANOMALOUS NATURE OF THIS PATTERN...AGAIN THE GUIDANCE
DIFFERS ON THE EXACT PLACEMENT AND EVOLUTION OF THE UPPER-LEVEL
FLOW. WHILE POPS INCREASE SLIGHTLY INTO LATE WEEK IN RESPONSE TO THE
ANTICIPATED BETTER FORCING ALOFT...THERE IS TOO MUCH UNCERTAINTY TO
WARRANT MORE AGGRESSIVE COVERAGE ATTM. FOR NOW...THESE FEATURES DO
LITTLE TO CHANGE THE ABOVE NORMAL TEMPERATURES WE EXPECT THROUGH THE
END OF NEXT WEEK.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AT KCLT...OCCASIONAL SHOWERS CONTINUE TO PIVOT SOUTHWARD TOWARD THE
AIRFIELD AROUND THE BACK SIDE OF THE UPPER LEVEL LOW PRESSURE
SYSTEM. DAYTIME INSTABILITY HAS WEAKENED ENOUGH THAT ANY ADDITIONAL
SHOWERS WILL LIKELY NOT CONTAIN SMALL HAIL. MAINLY VFR CIGS ARE
EXPECTED...BUT MVFR CIGS COULD APPROACH FROM THE NORTH IN THE BETTER
LOW LEVEL MOISTURE OVERNIGHT. ALTHOUGH MIXING IS NOT QUITE AS
DEEP...GUSTY NORTH WINDS WILL CONTINUE FOR A FEW HOURS INTO THE
OVERNIGHT. SHRA CHANCES WILL STEADILY DIMINISH OVERNIGHT INTO FRIDAY
MORNING...BUT LAPSE RATES WILL REMAIN SUFFICIENT FOR PROB30 CHANCES
TO RETURN FOR FRIDAY AFTERNOON. DEEP MIXING WILL PERMIT GUSTY
CONDITIONS ONCE AGAIN...WITH PEAK GUSTS 20 TO 30 KT POSSIBLE AS THE
PRESSURE GRADIENT TIGHTENS A BIT.
ELSEWHERE...THE NORTHERN TIER FROM KAVL TO KHKY WILL SEE THE BEST
CHANCES OF MOISTURE AND SHRA WRAPPING SOUTHWARD TOWARD THE
AIRFIELDS. MVFR CIGS LOOK LIKELY AS THE RAIN CONTINUES TO FALL...BUT
WITH MUCH LESS CHANCE OF SHRA AND LOWERING CIGS FARTHER SOUTH AT THE
SC TAF SITES. GUSTY CONDITIONS WILL ABATE OVERNIGHT EAST OF THE
MOUNTAINS BUT CONTINUE AT KAVL. DEEP MIXING WILL PERMIT GUSTS OF 20
TO 30 KT...POSSIBLY 35 KT AT KAVL...ON FRIDAY. ANOTHER ROUND OF
SCATTERED SHOWERS IS LIKELY THROUGH FRIDAY AFTERNOON AS STEEP LAPSE
RATES ALOFT PERSIST.
OUTLOOK...PROFILES WILL GRADUALLY DRY FRIDAY NIGHT INTO SATURDAY. A
COLD FRONT WILL APPROACH FROM THE NORTH THROUGH SUNDAY...WITH
ASSOCIATED PRECIPITATION POSSIBLY APPROACHING KAVL TO KHKY BEFORE
THE FRONT STALLS. WARMING CONDITIONS WITH A RETURN TO SW FLOW ARE
EXPECTED THROUGH EARLY NEXT WEEK.
CONFIDENCE TABLE...
00-06Z 06-12Z 12-18Z 18-00Z
KCLT MED 77% HIGH 91% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 80% MED 65% HIGH 93% HIGH 100%
KHKY MED 70% HIGH 93% 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 SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...HG/JMP
NEAR TERM...HG
SHORT TERM...RWH
LONG TERM...JMP
AVIATION...HG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
709 PM CDT THU MAY 5 2016
.UPDATE...
FOR 00Z AVIATION DISCUSSION.
&&
.DISCUSSION...
UPPER LOW POSITIONED OVER THE CAROLINAS THIS EVENING. A VERTICALLY
STACKED NORTHERLY FLOW KEEPING CONDITIONS ON THE COOL SIDE. CLOUD
COVER...ALSO NOTED ON THE BACKSIDE OF THE TROUGH AXIS AND IS
KEEPING A MOSTLY CLOUDY SKY ACROSS THE NORTHEASTERN TWO THIRDS OF
THE MID STATE. THE TREND WILL BE FOR THESE CLOUDS TO DECREASE BUT
IT MAY TAKE A FEW HOURS BEFORE THAT REALLY HAPPENS. THUS...WILL
NOTCH UP THE INITIAL CLOUD COVER AND INTERPOLATE TOWARD A MOSTLY
CLEAR NIGHT. WILL THEN REISSUE ZONES. OTW...REMAINDER OF FCST IN
GOOD SHAPE. WINDS WILL SLOWLY DECREASE OVERNIGHT.
&&
.AVIATION...
00Z TAF DISCUSSION.
PER ABOVE MENTIONED DISCUSSION...LOOKING FOR A DECREASING CLOUDINESS
TREND TO COMMENCE...BUT IT MAY TAKE A FEW HRS BEFORE THAT REALLY HAPPENS.
DO EXPECT NW SFC GUSTS TO 18-20KTS TO DISSIPATE BNA BY AROUND 06/02Z
PER WEAKENING SFC PRESSURE GRADIENT INFLUENCES ALONG DIURNAL MIXING
INFLUENCES ENDING. BREAKAGE IN BKN/OVC STRATO CU COVERAGE NOTED ACROSS
SRN OHIO VALLEY REGION...BUT AM HESITANT...ESPECIALLY WITH LATEST HRRR
LOW LEVEL ATM MOISTURE PROFILES SUPPORTIVE OF BKN CLOUD COVERAGE NOT
DISSIPATING AT CKV UNTIL AROUND 06/10Z...BNA 06/12Z...AND CSV 06/15Z.
WILL LEAN TOWARD MORE PESSIMISTIC HRRR CLOUD COVERAGE EROSION TIMEAGE
PER PREVIOUS FORECAST HISTORY ACROSS MID STATE PER SIMILAR EVENTS...BUT
WOULD CERTAINLY NOT BE SURPRISED TO SEE CEILING EROSIONS AT ALL TERMINALS
OCCUR SOONER. IF EROSIONS OCCUR EARLY ENOUGH...ESPECIALLY CSV...SOME
MVFR/IFR FOG INDUCED VSBYS/SIMILAR LOW STRATUS CEILINGS COULD OCCUR PER
PERSISTENT LOW LEVEL MOISTURE POOLING POTENTIAL BEING PRESENT ACROSS THIS
AREA OVER PAST 24+ HRS...ALONG WITH CLRING SKIES/LIGHT WINDS. ADDRESSED
POSSIBILITY WITH PREVAILING MVFR VSBYS/CEILINGS 06/08Z-06/15Z. OTHERWISE...
BUILDING RIDGING INFLUENCES SFC/ALOFT TO PROVIDE VFR/SKC CONDITIONS AT ALL
TERMINALS 06/14Z-06/24Z WITH NW/N SFC WINDS 5-10KTS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........31
LONG TERM..................21
AREA FORECAST DISCUSSION
NWS SEATTLE WA
845 PM PDT THU MAY 5 2016
.SYNOPSIS...HIGH PRESSURE ALOFT WILL BUILD OVER THE REGION FRIDAY
AND SATURDAY PROVIDING INCREASED SUNSHINE AND A RETURN TO ABOVE
NORMAL TEMPERATURES. A TROUGH WILL INDUCE MUCH COOLER ONSHORE FLOW
SATURDAY NIGHT THROUGH MONDAY WITH SOME DRIZZLE OR SHOWERS POSSIBLE.
DRY AND WARMER WEATHER RETURNS TUESDAY THROUGH THURSDAY.
&&
.SHORT TERM...MOST CLOUDS HAVE GONE FROM WESTERN WASHINGTON EXCEPT
FOR IN THE CASCADES. THERE HAVE BEEN ISOLATED SHOWERS NEAR THE
CASCADE CREST THIS EVENING BUT ANY LIGHTNING APPEARS TO BE EAST OF
THE CREST. WHITE PASS GOT JUST OVER A TENTH OF AN INCH IN A SHOWER.
THE SLOW TREND OF THE LAST DAY OR SO WILL CONTINUE...CLEARING FROM
THE WEST AND AN END TO THE CASCADE SHOWERS.
FRIDAY WILL BE DRY WITH HIGH PRESSURE ALOFT. SURFACE FLOW NEVER
BECOMES STRONGLY OFFSHORE BUT NORTH FLOW OFF THE WATER WILL BE
LIGHTER THAN TODAY AND 500 MB HEIGHTS RISE OVER 5700M. THIS SHOULD
ALLOW MOST AREAS TO REACH INTO THE 70S EXCEPT THE USUAL LOCALLY
COOLER SPOTS AROUND THE SAN JUANS AND PARTS OF THE STRAIT. THE
CASCADE FOOTHILLS AND SW INTERIOR AWAY FROM THE WATER COULD HIT THE
LOW 80S IN A FEW SPOTS.
DRY WEATHER PERSISTS INTO SATURDAY BUT AN UPPER TROUGH WILL BE
APPROACHING THE REGION FROM THE NORTHWEST. BEST BET IS FOR ANOTHER
WARM DAY SATURDAY FOLLOWED BY A STRONG MARINE PUSH SATURDAY NIGHT.
MODELS SHOW SPOTTY LIGHT QPF AND IMPLY SOME DRIZZLE IS POSSIBLE WITH
THE PUSH LATER SATURDAY NIGHT AND SUNDAY. LOCATIONS THAT DO MEASURE
WILL ONLY SEE VERY LIGHT AMOUNTS...PROBABLY NO MORE THAN A FEW
HUNDREDTHS. THE CLOUDS MAY REMAIN THROUGH THE DAY UNDER A DEEP
MARINE LAYER AND STRONG ONSHORE FLOW. HIGHS WILL BE IN THE UPPER 50S
AND LOW 60S. MERCER/BURKE
.LONG TERM...PREVIOUS DISCUSSION...THE GFS AND ECMWF DIG ADDITIONAL
UPPER LEVEL ENERGY ACROSS WRN WA SUNDAY NIGHT INTO MONDAY. SOME OF
THE STRONGER SOLUTIONS SHOW A CLOSED LOW DEVELOPING AND DIGGING SE
ACROSS THE CASCADES INTO ERN WA. THIS SHOULD MAINTAIN A MOSTLY
CLOUDY AND COOL MARINE AIR MASS OVER WRN WA INTO MONDAY. SOME
SHOWERS COULD ALSO LINGER...ESPECIALLY ACROSS THE CASCADES WITH SNOW
LEVELS DOWN TO 5000 FEET. MOISTURE STILL LOOKS QUITE LIMITED AND
PRECIPITATION AMOUNTS WILL REMAIN LIGHT. IF THE TROUGH PULLS AWAY
QUICK ENOUGH DURING THE AFTERNOON...THERE IS A BETTER CHANCE FOR
PARTIAL BREAK OUT AND HIGHS COULD WARM A COUPLE DEGREES OVER SUNDAY.
LONG RANGE MODELS AGREE ON SOME RIDGING BY TUESDAY AND ESPECIALLY
WEDNESDAY. THIS SHOULD PROVIDE DRY WEATHER AND YET ANOTHER WARMING
TREND WITH HIGHS LIKELY TO REACH +10F ABOVE AVERAGE. THE ECMWF IS
WEAKER WITH THE RIDGE THAN THE GFS/CANADIAN AND SUPPRESSES HEIGHTS BY
THURSDAY. THIS COULD INDUCE SOME ONSHORE FLOW AND COOLING. THE
AVERAGE OF THE MODELS KEEP A STRONGER RIDGE IN PLACE AND IMPLY
CONTINUED WARM CONDITIONS...WELL ABOVE AVERAGE...THROUGH THE END OF
THE WEEK. KEPT TEMPERATURES BELOW POTENTIAL HIGHS BUT WARMER THAN THE
ECMWF WOULD SUGGEST. HIGHS IN THE 70S ARE A GOOD BET...IF NOT SOME
80S MID TO LATE WEEK. MERCER
&&
.AVIATION...SOUTHERLY FLOW CONTINUES ALOFT OVER WESTERN WASHINGTON
AHEAD OF AN UPPER TROUGH THAT IS ALONG THE COAST THIS EVENING. THE
FLOW OVER THE OFFSHORE WATERS HAS TURNED NORTHERLY. THE AIR MASS
IS GENERALLY DRY EXCEPT FOR MID AND HIGH LEVEL MOISTURE ASSOCIATED
WITH CONVECTION OVER THE CASCADES. NORTHWEST ONSHORE FLOW
CONTINUES AT LOW LEVELS BUT THERE IS LITTLE MOISTURE IN THE MARINE
LAYER. CEILINGS SHOULD REMAIN MOSTLY 12000 FT OR ABOVE TONIGHT
AND FRIDAY...EXCEPT PATCHY FOG AND STRATUS AT THE COAST EARLY
FRIDAY MORNING.
KSEA...NORTH WIND 6-12 KT RISING TO 8-16 KT FRIDAY. CEILINGS
SHOULD BE ABOVE 12000 FT. MCDONNAL
&&
.MARINE...NORTHWEST ONSHORE FLOW WILL PERSIST TONIGHT THROUGH
MONDAY...WITH HIGH PRESSURE OFFSHORE AND LOW PRESSURE EAST OF THE
CASCADES. SMALL CRAFT ADVISORY NORTHWEST WINDS DEVELOPED OVER THE
COASTAL WATERS THIS EVENING...AND A SMALL CRAFT ADVISORY HAS BEEN
ISSUED. WESTERLY GALES ARE LIKELY IN THE STRAIT OF JUAN DE FUCA
SATURDAY EVENING WHEN A STRONG MARINE PUSH WILL OCCUR. MCDONNAL
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 11 PM PDT FRIDAY FOR COASTAL WATERS
FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL
WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL
WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-
COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10
NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER
10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER OUT 10 NM.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
[top]
Area Forecast Discussion
National Weather Service Spokane WA
600 PM PDT THU MAY 5 2016
.SYNOPSIS...
Isolated showers and thunderstorms will be possible mainly across
southeast Washington into the Idaho Panhandle this evening. Some
storms will be capable of heavy rainfall...hail...and gusty winds.
Improving but breezy conditions will begin on Friday, lasting
through the weekend. More unsettled and cooler weather is expected
next week.
&&
.DISCUSSION...
LAPS analysis as of 5 pm indicated the best instability over SE
Washington into the Central Panhandle Mountains as well as the
Clearwaters with CAPE VALUES OF 500-1000 J/KG with very minimal
convective inhibition. However with the low off the Central CA
coast there is no large scale forcing to initiate convection. This
should change this evening however for the Camas Prairie, Lewiston
area, and Blue Mountains as a couple stronger storms currently
producing quite a bit of lightning approach the area...with
outflow winds likely inititating new storms as they approach these
areas. Will have to monitor potential for gusty winds and small
hail as these approach. Further north...across the Spokane/Coeur
D`Alene area...North Idaho Panhandle...and much of Central and NE
Washington low level northerly winds as well as earlier cloud
cover should help to stabilize the air mass this evening. The HRRR
shows convection falling apart as it tries to make it into these
areas this evening and thus POP`s were lowered for the remainder
of tonight. JW
&&
.AVIATION...
00Z TAFS: Main aviation concern is the potential for thunderstorms
mainly over southeast Washington and the south Idaho Panhandle
this evening which could impact the KLWS/KPUW TAF sites. Thus far
the storms are weakening as they come off the Blue Mountains and
the HRRR shows storms weakening this evening as they approach the
KLWS/KPUW TAF sites. Thus for now confidence is only low to
moderate of these sites being impacted and thus thunder was
removed for now. However will be monitoring radar trends.
Otherwise a tight northerly pressure gradient develops tonight
which will result in increasing north-northeast winds especially at
KMWH/KCOE by Friday morning. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 54 77 54 81 55 76 / 10 10 10 0 0 10
Coeur d`Alene 49 76 50 81 52 75 / 20 10 10 10 0 10
Pullman 49 75 49 78 51 72 / 20 10 10 10 0 10
Lewiston 53 81 54 83 56 78 / 40 20 10 10 10 10
Colville 45 81 47 85 48 80 / 10 10 10 0 0 10
Sandpoint 47 74 44 79 46 73 / 20 10 10 0 0 20
Kellogg 45 73 44 79 46 72 / 50 10 10 10 0 20
Moses Lake 52 83 53 86 52 80 / 10 10 0 0 0 0
Wenatchee 54 82 57 86 58 77 / 10 10 0 0 0 0
Omak 48 81 53 85 52 79 / 10 10 0 0 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1043 PM PDT THU MAY 5 2016
.SYNOPSIS...AN UPPER LEVEL LOW OFF OF THE CENTRAL CALIFORNIA COAST
WILL SHIFT INLAND OVER SOUTHERN CALIFORNIA ON FRIDAY AND RESULT
IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THROUGH FRIDAY
EVENING. SCATTERED SHOWERS WILL LIKELY LINGER INTO SATURDAY WITH
DRY WEATHER EXPECTED TO RETURN TO MOST AREAS BY SUNDAY. DRY
WEATHER IS THEN FORECAST THROUGH THE MIDDLE OF NEXT WEEK ALONG
WITH A GRADUAL WARMING TREND.
&&
.DISCUSSION...AS OF 9:10 PM PDT THURSDAY...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS OCCURRED ACROSS PORTIONS OF OUR FORECAST
AREA TODAY. THIS CONVECTIVE PRECIPITATION WAS TRIGGERED BY AN
UPPER LOW THAT IS CURRENTLY CENTERED ABOUT 100 MILES SOUTHWEST OF
MONTEREY. THE MOST SIGNIFICANT RAINFALL TO OCCUR FROM TODAY`S
SHOWER ACTIVITY WAS AT PINNACLES NATIONAL PARK WHERE 0.33" WAS
RECORDED. IN OTHER LOCATIONS WHERE RAIN FELL TODAY...AMOUNTS WERE
MOSTLY LESS THAN A TENTH OF AN INCH.
A LINE OF INTENSE SHOWERS AND THUNDERSTORMS DEVELOPED JUST TO THE
EAST OF SANTA CLARA AND SAN BENITO COUNTIES LATE THIS AFTERNOON.
BUT THIS CONVECTIVE ACTIVITY EITHER WEAKENED CONSIDERABLY OR
DISSIPATED AS IT MOVED TO THE NORTHWEST TOWARDS THE SANTA CLARA
AND HOLLISTER VALLEYS THIS EVENING. NOW THAT THE SUN HAS SET ALL
ACTIVITY HAS DIMINISHED AND EXPECT ONLY ISOLATED SHOWERS
OVERNIGHT.
THE CUTOFF LOW IS FORECAST TO MOVE GRADUALLY TO THE
SOUTHEAST OVERNIGHT AND THEN TURN TO THE EAST AND INLAND OVER
SOUTHERN CA ON FRIDAY MORNING. MEANWHILE...A SHORTWAVE TROUGH
ROTATING AROUND THE LOW IS FORECAST TO MOVE ACROSS OUR AREA ON
FRIDAY MORNING AND EARLY FRIDAY AFTERNOON. THE MODELS ALL SHOW AN
ORGANIZED AREA OF PRECIP WITH THIS SHORTWAVE...TRACKING FROM
NORTHEAST TO SOUTHWEST ACROSS OUR AREA TOMORROW.
HOWEVER...PRECISELY WHERE THAT PRECIP WILL BE FOCUSED IS DIFFICULT
TO SAY GIVEN DIFFERING MODEL SOLUTIONS. THE 00Z NAM FORECASTS
THIS AREA OF PRECIP TO TRACK ACROSS THE CENTRAL SF BAY AREA FROM
MID MORNING TO EARLY AFTERNOON. THE 00Z GFS AND LATEST HRRR MODEL
BOTH INDICATE THIS PRECIP WILL BE FOCUSED ACROSS EASTERN ALAMEDA
AND SANTA CLARA COUNTIES AND SOUTH INTO SAN BENITO COUNTY. GIVEN
MODEL DIFFERENCES...BELIEVE IT`S BEST NOT TO TRY TO PINPOINT
AREAS OF HIGHEST PRECIP POTENTIAL AND INSTEAD CONTINUE TO
DISTRIBUTE CHANCE POPS ACROSS OUR FORECAST AREA RATHER UNIFORMLY.
THUNDERSTORMS ARE A POSSIBILITY ONCE AGAIN TOMORROW.
HOWEVER...BECAUSE THE SHORTWAVE TROUGH WILL HAVE ROTATED OUT OF
OUR AREA PRIOR TO THE BEST SURFACE HEATING IN THE
AFTERNOON...THUNDERSTORM POTENTIAL WILL BE SOMEWHAT DIMINISHED.
THE UPPER LOW IS FORECAST TO LIFT TO THE NORTHEAST AND INTO THE
SOUTHERN GREAT BASIN BY SATURDAY. THE MODELS AGREE THAT MOISTURE
WILL CONTINUE TO WRAP AROUND THE LOW AND ACROSS OUR AREA ON
SATURDAY AND THAT INSTABILITY WILL REMAIN SUFFICIENT FOR SCATTERED
SHOWERS TO CONTINUE. HOWEVER...THUNDERSTORM CHANCES WILL HAVE
FADED CONSIDERABLY BY THEN.
A FEW SHOWERS MAY LINGER INTO SUNDAY MORNING...BUT FOR THE MOST
PART SUNDAY LOOKS TO BE A DRY DAY WITH TEMPERATURES NEAR AVERAGE.
DRY WEATHER WILL THEN CONTINUE THROUGH THE MIDDLE PART OF NEXT
WEEK AS AN UPPER RIDGE BUILDS NEAR THE WEST COAST. THIS RIDGE WILL
ALSO MEAN A GRADUAL WARMING TREND FOR MUCH OF NEXT WEEK. LONGER
RANGE MODELS HINT AT THE POSSIBILITY OF ANOTHER CUTOFF LOW
IMPACTING OUR AREA BY THE FOLLOWING WEEKEND (MAY 14 AND 15).
&&
.AVIATION...AS OF 10:30 PM PDT THURSDAY...UPPER LEVEL LOW WEST OF
THE CENTRAL COAST MOVING TOWARDS SOUTHERN CALIFORNIA. ISOLATED
SHOWERS ARE CONFINED TO THE HILLS THIS EVENING WHILE PATCHY LOW
CLOUDS ARE ALONG THE COAST. MVFR EXPECTED TO SPREAD OVER THE MRY
BAY AREA THIS EVENING AND INTO THE SFO BAY AREA LATER TONIGHT.
AN UPPER LEVEL DISTURBANCE ROTATING AROUND THE LOW WILL BRING A
CHANCE OF SHOWERS TO THE AREA FRIDAY MORNING. THESE SHOWERS WILL
BE COMING FROM THE NORTHEAST. MVFR CIGS EXPECTED MOST OF THE DAY
FRIDAY. CANNOT RULE OUT AN ISOLATED THUNDERSTORM FRIDAY AFTERNOON.
VICINITY OF KSFO...MVFR CIGS AFTER 12Z CONTINUING THROUGH THE REST
OF THE DAY. SCATTERED SHOWERS AFTER 16Z. MAINLY LIGHT SOUTHWEST
WINDS.
SFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY TERMINALS...MVFR CIGS AFTER 08Z. A FEW SHOWERS
POSSIBLE AFTER 17Z.
&&
.MARINE...AS OF 10:30 PM PDT THURSDAY...LOW PRESSURE DEVELOPING
OVER NEVADA WILL MODERATE NORTHERLY WINDS TO THE OUTER WATERS
NORTH OF PT REYES AND LIGHT SOUTH WINDS ELSEWHERE THROUGH FRIDAY.
AN UPPER LEVEL LOW OFF THE CENTRAL CALIFORNIA COAST WILL MOVE INTO
SOUTHERN CALIFORNIA ON FRIDAY. THIS WILL BRING A SLIGHT CHANCE OF
THUNDERSTORMS TONIGHT AND FRIDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: W PI
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
912 PM PDT THU MAY 5 2016
.SYNOPSIS...AN UPPER LEVEL LOW OFF OF THE CENTRAL CALIFORNIA COAST
WILL SHIFT INLAND OVER SOUTHERN CALIFORNIA ON FRIDAY AND RESULT
IN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THROUGH FRIDAY
EVENING. SCATTERED SHOWERS WILL LIKELY LINGER INTO SATURDAY WITH
DRY WEATHER EXPECTED TO RETURN TO MOST AREAS BY SUNDAY. DRY
WEATHER IS THEN FORECAST THROUGH THE MIDDLE OF NEXT WEEK ALONG
WITH A GRADUAL WARMING TREND.
&&
.DISCUSSION...AS OF 9:10 PM PDT THURSDAY...SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS OCCURRED ACROSS PORTIONS OF OUR FORECAST
AREA TODAY. THIS CONVECTIVE PRECIPITATION WAS TRIGGERED BY AN
UPPER LOW THAT IS CURRENTLY CENTERED ABOUT 100 MILES SOUTHWEST OF
MONTEREY. THE MOST SIGNIFICANT RAINFALL TO OCCUR FROM TODAY`S
SHOWER ACTIVITY WAS AT PINNACLES NATIONAL PARK WHERE 0.33" WAS
RECORDED. IN OTHER LOCATIONS WHERE RAIN FELL TODAY...AMOUNTS WERE
MOSTLY LESS THAN A TENTH OF AN INCH.
A LINE OF INTENSE SHOWERS AND THUNDERSTORMS DEVELOPED JUST TO THE
EAST OF SANTA CLARA AND SAN BENITO COUNTIES LATE THIS AFTERNOON.
BUT THIS CONVECTIVE ACTIVITY EITHER WEAKENED CONSIDERABLY OR
DISSIPATED AS IT MOVED TO THE NORTHWEST TOWARDS THE SANTA CLARA
AND HOLLISTER VALLEYS THIS EVENING. NOW THAT THE SUN HAS SET ALL
ACTIVITY HAS DIMINISHED AND EXPECT ONLY ISOLATED SHOWERS
OVERNIGHT.
THE CUTOFF LOW IS FORECAST TO MOVE GRADUALLY TO THE
SOUTHEAST OVERNIGHT AND THEN TURN TO THE EAST AND INLAND OVER
SOUTHERN CA ON FRIDAY MORNING. MEANWHILE...A SHORTWAVE TROUGH
ROTATING AROUND THE LOW IS FORECAST TO MOVE ACROSS OUR AREA ON
FRIDAY MORNING AND EARLY FRIDAY AFTERNOON. THE MODELS ALL SHOW AN
ORGANIZED AREA OF PRECIP WITH THIS SHORTWAVE...TRACKING FROM
NORTHEAST TO SOUTHWEST ACROSS OUR AREA TOMORROW.
HOWEVER...PRECISELY WHERE THAT PRECIP WILL BE FOCUSED IS DIFFICULT
TO SAY GIVEN DIFFERING MODEL SOLUTIONS. THE 00Z NAM FORECASTS
THIS AREA OF PRECIP TO TRACK ACROSS THE CENTRAL SF BAY AREA FROM
MID MORNING TO EARLY AFTERNOON. THE 00Z GFS AND LATEST HRRR MODEL
BOTH INDICATE THIS PRECIP WILL BE FOCUSED ACROSS EASTERN ALAMEDA
AND SANTA CLARA COUNTIES AND SOUTH INTO SAN BENITO COUNTY. GIVEN
MODEL DIFFERENCES...BELIEVE IT`S BEST NOT TO TRY TO PINPOINT
AREAS OF HIGHEST PRECIP POTENTIAL AND INSTEAD CONTINUE TO
DISTRIBUTE CHANCE POPS ACROSS OUR FORECAST AREA RATHER UNIFORMLY.
THUNDERSTORMS ARE A POSSIBILITY ONCE AGAIN TOMORROW.
HOWEVER...BECAUSE THE SHORTWAVE TROUGH WILL HAVE ROTATED OUT OF
OUR AREA PRIOR TO THE BEST SURFACE HEATING IN THE
AFTERNOON...THUNDERSTORM POTENTIAL WILL BE SOMEWHAT DIMINISHED.
THE UPPER LOW IS FORECAST TO LIFT TO THE NORTHEAST AND INTO THE
SOUTHERN GREAT BASIN BY SATURDAY. THE MODELS AGREE THAT MOISTURE
WILL CONTINUE TO WRAP AROUND THE LOW AND ACROSS OUR AREA ON
SATURDAY AND THAT INSTABILITY WILL REMAIN SUFFICIENT FOR SCATTERED
SHOWERS TO CONTINUE. HOWEVER...THUNDERSTORM CHANCES WILL HAVE
FADED CONSIDERABLY BY THEN.
A FEW SHOWERS MAY LINGER INTO SUNDAY MORNING...BUT FOR THE MOST
PART SUNDAY LOOKS TO BE A DRY DAY WITH TEMPERATURES NEAR AVERAGE.
DRY WEATHER WILL THEN CONTINUE THROUGH THE MIDDLE PART OF NEXT
WEEK AS AN UPPER RIDGE BUILDS NEAR THE WEST COAST. THIS RIDGE WILL
ALSO MEAN A GRADUAL WARMING TREND FOR MUCH OF NEXT WEEK. LONGER
RANGE MODELS HINT AT THE POSSIBILITY OF ANOTHER CUTOFF LOW
IMPACTING OUR AREA BY THE FOLLOWING WEEKEND (MAY 14 AND 15).
&&
.AVIATION...AS OF 4:30 PM PDT THURSDAY...UPPER LEVEL LOW WEST OF
THE CENTRAL COAST AREA WITH SCATTERED SHOWERS ROTATING THROUGH
THE AREA FROM SOUTH TO NORTH. CIGS HAVE REMAINED AT OR ABOVE 3000
FEET BUT MAY LOWER INTO MVFR RANGE TONIGHT AS LOW-LEVEL COOLING
TAKES PLACE. THE LOW WILL MOVE SLOWLY INTO SOUTHERN CALIFORNIA
TONIGHT AND FRIDAY WITH WRAP-AROUND SHOWERS CONTINUING OVER THE
AREA. CANNOT RULE OUT A THUNDERSTORM DURING THE AFTERNOON HOURS.
VICINITY OF KSFO...OCCASIONAL MVFR CIGS THROUGH 04Z. BECOMING
PREDOMINATELY MVFR AFTER 04Z AS COOLING OF THE LOWER ATMOSPHERE
TAKES PLACE. RADAR INDICATES NO SHOWER ACTIVITY IN THE VICINITY
BUT SCATTERED SHOWERS MAY SPREAD INTO THE AREA FROM THE SOUTH
TONIGHT AND FROM THE EAST TO SOUTHEAST FRIDAY. SOUTHWEST WINDS
10-15 KT.
SFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY TERMINALS...VFR WITH CIGS REMAINING ABOVE 3000 FEET.
CIGS LOWERING TO MVFR RANGE AFTER 06Z. VCSH THROUGH THE PERIOD.
&&
.MARINE...AS OF 4:30 PM PDT THURSDAY...A STORM SYSTEM OVER THE
REGION WILL BRING MODERATE NORTHERLY WINDS TO THE OUTER WATERS
NORTH OF PT REYES AND LIGHT SOUTH WINDS ELSEWHERE INTO TOMORROW.
HAZARDOUS CONDITIONS FROM SQUARED SEAS WILL BE ALSO BE POSSIBLE IN
THE NORTHERN OUTER WATERS. THIS STORM WILL PRODUCE SHOWERS AND
POSSIBLY THUNDERSTORMS OVER THE COASTAL WATERS TODAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT ARENA TO PIGEON PT 10-60 NM
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: W PI
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1141 PM CDT THU MAY 5 2016
...AVIATION UPDATE...
.SYNOPSIS...
ISSUED AT 315 PM CDT THU MAY 5 2016
HIGH PRESSURE RIDGE OVER THE CWA PROVIDING FULL SUNSHINE...LIGHT
WINDS AND PLEASANT SPRING TEMPERATURES. 2 PM READINGS WERE IN THE
UPPER 50S TO LOWER 60S. WEAK CONVERGENCE IN THE MID LEVELS HAS
CAUSED A BAND OF MID LEVEL CLOUDS MUCH OF THE DAY FROM EASTERN MN
INTO CENTRAL IA AND NORTH CENTRAL MO. THIS HAS PRETTY MUCH STAYED
JUST WEST OF THE DVN CWA AS THE CLOUDS DRIFT SOUTHWARD. THERE HAS
EVEN BEEN A FEW LIGHT SHOWERS REACHING THE GROUND IN FAR WESTERN
WI AND THE EAST METRO OF THE TWIN CITIES. THESE SHOWERS WERE
OCCURRING IN THE STRONGER ZONE OF WARM AIR ADVECTION.
ELSEWHERE...TEMPERATURES WERE IN THE UPPER 70S TO MID 80S IN THE
GREAT PLAINS...WITH SOME LOWER 90S IN ND AND MANITOBA. RELATIVE
HUMIDITY THERE WAS 15 PERCENT WITH SOUTHWEST WINDS GUSTING OVER 30
MPH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 315 PM CDT THU MAY 5 2016
MUCH WARMER TEMPERATURES IN THE SHORT TERM.
TONIGHT...HIGH PRESSURE RIDGE WILL BE PUSHING SOUTH OF THE AREA
ALLOWING FOR WARMER TEMPERATURES AS WINDS BECOMING LIGHT SOUTHWEST.
LOWS WILL BE ABOUT 10 DEGREES WARMER THAN LAST NIGHT...IN THE UPPER
40S. SCATTERED MID LEVEL CLOUDS SHOULD DEVELOP OVERNIGHT BUT EXPECTING
ANY SHOWERS TO REMAIN IN WISCONSIN WHERE THE BETTER WARM AIR ADVECTION
WILL EXIST. BELIEVE THE HRRR IS OVERDOING THE SHOWERS IN THE DVN CWA
BUT CAN`T RULE OUT A COUPLE OF SPRINKLES. WON`T MENTION IN THE GRIDS
BUT SOMETHING FOR LATER SHIFTS TO MONITOR.
FRIDAY...WARM DAY WITH THE RETURN FLOW AROUND THE HIGH PRESSURE
SYSTEM DROPPING INTO THE LOWER MS VALLEY. A WEST TO SOUTHWEST
WIND...850 MB TEMPERATURES OF +15 TO 16C AND A DRY AIRMASS SHOULD
SUPPORT LOWER 80S AT MOST LOCATIONS. IT IS POSSIBLE A FEW SPOTS
MAY MANAGE TO SEE 85 DEGREES CONSIDERING WE SHOULD HAVE SUNNY SKIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 315 PM CDT THU MAY 5 2016
SATURDAY...EASTWARD PROGRESSION OF THE 500MB RIDGE AXIS WILL BE
HALTED BY A SHORTWAVE TROUGH DIVING SOUTHEASTWARD THROUGH THE UPPER
MIDWEST AND GREAT LAKES. SIGNIFICANT HEIGHT FALLS ASSOCIATED WITH
THIS SYSTEM ARE FORECAST TO REMAIN OVER WISCONSIN AND MICHIGAN AND
POINTS TO THE E/NE. AS A RESULT...LIFT OVER E IOWA/W ILLINOIS WILL
BE WEAK AND PRIMARILY RESTRICTED TO LOW-LEVEL CONVERGENCE ALONG A
SOUTHWARD MOVING COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ALONG AND SLIGHTLY AHEAD OF THE
FRONT...POPS ARE IN THE 30-40 PERCENT RANGE WITH RAIN AMOUNTS LESS
THAN A TENTH FOR MOST AREAS. THE FRONT IS FORECAST TO REACH THE
SOUTHERN CWA BY THE MID TO LATE AFTN.
THUNDERSTORM DETAILS...THE BEST CHANCES FOR A FEW STRONG STORMS IN
THE DVN CWA ARE IN THE COUNTIES ALONG AND SOUTH OF HIGHWAY 34...TO
THE WEST OF GALESBURG...WHERE MUCAPES MAY EXCEED 1500 J/KG AND 0-6
KM BULK SHEAR IS NEAR 45 KTS OR SLIGHTLY HIGHER.
SUNDAY THROUGH TUESDAY...SATURDAY/S COLD FRONT WILL BECOME QUASI-
STATIONARY SATURDAY NIGHT AND RETURN AS A WARM FRONT SUNDAY AND
MONDAY AS IT IS FORCED BY A NEW AREA OF LOW PRESSURE FORMING IN THE
WEST-CENTRAL PLAINS. SHOWER AND THUNDERSTORM CHANCES ARE HIGHEST
FROM SUNDAY NIGHT INTO TUESDAY. GFS 850MB WV TRANSPORT IS MAXIMIZED
ON MONDAY AND MONDAY NIGHT AS PWATS INCREASE TO 1.25 INCHES TO THE
ESE OF A COHERENT 850MB LOW MOVING INTO E NEBRASKA.
RAIN POTENTIAL...THE THREAT FOR WIDESPREAD HEAVY RAIN WITH THIS LOW
PRESSURE SYSTEM HIGHLIGHTED IN THE CPC 3-7 DAY HAZARDOUS WEATHER
OUTLOOK HAS NOW SHIFTED FURTHER TO THE EAST TO INCLUDE THE ENTIRE
FORECAST AREA. WHILE PWATS ARE NOT FORECAST TO BECOME ANOMALOUSLY
HIGH...REMAINING BELOW 1 STANDARD DEVIATION...THE SYSTEM IS A SLOW
MOVER AND SHOWS A SOLID MOISTURE CONNECTION WITH THE WESTERN GULF OF
MEXICO...VIA 850 WV TRANSPORT VECTORS.
THE WPC 5-7 DAY QPF SUPPORTS CPC/S OUTLOOK...PAINTING A GENERAL 1 TO
3 INCHES ALONG WHERE THE WARM FRONT SETS UP AND THE 850MB LOW
TRACKS...FROM EASTERN NEBRASKA THROUGH IOWA AND NORTHERN
MISSOURI INTO ILLINOIS AND SOUTHERN WISCONSIN.
THUNDERSTORM POTENTIAL...TOO EARLY TO FORECAST WITH MUCH DETAIL.
HOWEVER...SOME STRONG OR SEVERE STORMS ARE POSSIBLE ON MONDAY OVER
THE SOUTHWEST SECTION OF THE FORECAST AREA.
WIDESPREAD CLOUDS AND THE THREAT FOR RAIN TRANSLATES INTO NO BIG
WARM UPS WITH AVG HIGH TEMPS IN THE LOWER 70S.
WEDNESDAY...SEASONAL TEMPS CONTINUE WITH SLIGHT CHANCES FOR SHOWERS
OR AN ISOLATED STORM. UTTECH
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1140 PM CDT THU MAY 5 2016
HIGH PRESSURE WILL BRING A VERY CLEAR CALM AND VFR NIGHT TO THE
REGION TONIGHT...FOLLOWED BY A VFR DAY OF CLEAR/HIGH CLOUDS
FRIDAY. WINDS WILL BE LIGHT WEST TO NORTHWEST OVERNIGHT...FOLLOWED
BY A TURN TO SOUTHWEST TO WEST FRIDAY AROUND 10-15 KTS THROUGH THE
DAYTIME HOURS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...UTTECH
AVIATION...ERVIN
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1200 AM CDT FRI MAY 6 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Friday)
Issued at 347 PM CDT THU MAY 5 2016
Northwest flow aloft continues across central and eastern Kansas
this afternoon as we are in between a trough in the eastern Pacific
and another over the eastern U.S.. Surface high extended from Iowa
across eastern Kansas and into north Texas. The surface high will
move off slowly to the east through tonight with southerly return
flow developing from west to east after midnight. Another night of
clear skies are expected tonight with lows dropping down into the
upper 40s to lower 50s. Heights rise on Friday along with increasing
warm advection and we should mix up to 850 mb or so across the area.
Expect highs to reach the lower 80s with a few readings in the mid
80s in central Kansas. Winds increase through the day with
increasing pressure gradient. Should also mix down stronger winds
aloft which will yield wind gusts around 27 mph in north central
Kansas in the afternoon.
.LONG TERM...(Friday Night through Thursday)
Issued at 347 PM CDT THU MAY 5 2016
Friday Night through Sunday...
Warm air advection pattern still ramps up Friday night but limited
moisture and instability aloft and dry layers below should keep any
precip limited to sprinkles at most. Frontal boundary still appears
to sink into the area Saturday afternoon but moisture values still
recovering and warm air aloft should make local thunderstorm
development difficult but small chances still justified in northern
areas in the afternoon. Have inched up high temps for central and
southern areas Saturday given the overnight WAA but with some high
cloud and uncertainty on boundary location confidence is not high on
specifics. More organized thunderstorm development is expected to
occur in northeast Colorado and western Nebraska Saturday afternoon
which could translate east over ridge and along the elevated front
make its way into the area per Corfidi vectors. Could see MCS type
precip linger into Sunday morning but area could easily be in
moderately unstable airmass in the afternoon still well downstream
of the upper low. If the old front or an outflow remains in the area
there will be some chance for thunderstorms in peak heating. Winds
aloft should be increasing somewhat but there will be some potential
for severe weather.
Sunday Night through Thursday...
Uncertainty remains high for evolution of thunderstorm activity
Sunday evening. Model to model consistency remains low with the
placement of the warm front. Current 12Z guidance would suggest the
warm front would position along the KS/NE border. The next question
is will surface-base convection occur along the warm front. 12Z
ECMWF/GFS forecast soundings along the KS/NE border valid at 00Z
Monday suggest very weak to perhaps a completely eroded EML. If this
solution were to come to fruition, all modes of severe weather would
become possible as moderate instability and sufficient low-
level/deep-layer shear will be in place. Good agreement amongst the
ECMWF and GFS with passage of an upper level shortwave trough Sunday
night into Monday morning. This solution suggests convection along
the dryline in central/southern KS should congeal into line of
elevated convection late Sunday evening and progress eastward across
the area. Severe weather would be possible across the area as MUCAPE
of 1500-2000 J/KG and deep-layer shear near 40-50 knots would
support large hail and damaging wind gusts. Zonal to perhaps
northwest flow returns for the middle of week. Precipitation chances
increase Wednesday afternoon into Thursday as an embedded trough
within the northern stream sweeps across the central plains.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1151 PM CDT THU MAY 5 2016
VFR conditions through the TAF with light winds tonight,
occasional gusts up to 20 kts Friday afternoon, and then decreased
gusts after sunset.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Baerg/65
AVIATION...Barjenbruch
Area Forecast Discussion
National Weather Service Dodge City KS
1200 AM CDT FRI MAY 6 2016
...updated aviation...
.SHORT TERM...(This evening through Friday)
Issued at 142 PM CDT Thu May 5 2016
Temperatures were rising faster than the forecast T curve early
this morning, and a change to the Experimental HRRR appears to
have captures the temperature forecast a little better in the
midday. It may be a couple of degrees overdone as it is warmer
than all the other guidance/blends, however with it being early
May now the warming can last later in the day. The forecast high
was generally bumped about 3 degrees over the area. The surface
high will continue to give way to gradual troughing over eastern
Colorado and the extreme western counties overnight. Much more
breezy conditions to marginally windy conditions can be expected
Friday.
.LONG TERM...(Friday night through Thursday)
Issued at 142 PM CDT Thu May 5 2016
Continued focus exists on the weekend for severe weather
potential. Saturday and Sunday present somewhat different pattern
recognition setups with marginal shear on Saturday, increasing by
Sunday as the upper jet advances into the central High Plains.
CAPES appear moderate on Saturday, and a few hail and wind
producing severe storms could develop near the dryline in this
marginal shear environment. The ECMWF is the model that pushes the
dryline almost out of our forecast area on Sunday afternoon
before convection initiation, while the GFS was far more emphatic
with convection occurring farther west. Many characteristics of
the mesoscale are as of yet unknown, however thunderstorms are
probable this weekend. The best chance for the most widespread
severe and especially tornadic threat would be more likely farther
north where the models are in agreement with placement of the warm
front.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1200 AM CDT Fri May 6 2016
VFR expected through TAF pd. LLWS expected overnight and then again
tomorrow overnight. Southerly winds will increase 20-30 kt beginning
around 18Z as lee trough deepens.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 54 86 59 84 / 0 0 10 30
GCK 54 88 57 83 / 0 10 10 30
EHA 51 85 55 82 / 0 10 10 20
LBL 53 87 57 85 / 0 0 10 20
HYS 52 87 60 82 / 0 10 10 50
P28 54 86 60 84 / 0 0 10 20
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS JACKSON KY
405 AM EDT FRI MAY 6 2016
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 405 AM EDT FRI MAY 6 2016
07Z SFC ANALYSIS SHOWS LOW PRESSURE OFF TO THE EAST OF THE
APPALACHIANS. WHILE HIGH PRESSURE IS FOUND TO THE SOUTHWEST. A FEW
LINGERING LIGHT SHOWERS ARE DRIFTING SOUTH THROUGH FAR EASTERN
KENTUCKY FROM THAT EASTERN LOW. IN CONJUNCTION WITH THIS...LOW
AND MID LEVEL CLOUDS ARE FOUND CLOSER TO THE VIRGINIA AND WEST
VIRGINIA BORDER. IN THE CLEARING TO THE WEST OF THE BORDER
AREAS...PATCHY FOG IS NOTED IN THE SOME OF THE OBSERVATIONS.
TEMPERATURES ARE RUNNING IN THE LOW TO MID 40S ACROSS THE AREA
WITH DEWPOINTS NOT FAR AWAY...WHILE WINDS ARE GENERALLY LIGHT
FROM THE NORTHWEST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A CONUS OMEGA BLOCK
SHIFTING EAST AND OPENING UP DURING THE NEXT 48 HOURS. A DEEP
CLOSED LOW DESCENDING THROUGH THE SOUTHERN APPALACHIANS THIS
MORNING WILL PIVOT TO THE NORTHEAST BY EVENING BEFORE BEING PICKED
UP BY THE NORTHERN STREAM FLOW AND DEPARTING OFF THE MID ATLANTIC
COAST SATURDAY EVENING. IN ITS WAKE...RISING HEIGHTS AND RIDGING
WILL SPREAD FROM THE SOUTHERN PLAINS AND ACROSS THE MISSISSIPPI
VALLEY TOWARD KENTUCKY. HOWEVER...IN ASSOCIATION WITH A HUDSON BAY
UPPER LOW DESCENDING INTO THE GREAT LAKES...A MINOR WAVE WILL
SQUEEZE BY EASTERN KENTUCKY TO THE NORTH LATE SATURDAY. GIVEN THE
MODEL AGREEMENT HAVE FOLLOWED A GENERAL BLEND WITH A STRONG LEAN
TOWARD THE HRRR EARLY ON AND THE NAM12 THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A MILDER DAY THAN YESTERDAY AS SOME
SUNSHINE RETURNS AND THE COLD AIR DEPARTS TO THE EAST. ISOLATED TO
SCATTERED SHOWERS WILL BE FOUND OVER FAR EASTERN KENTUCKY THROUGH
THE AFTERNOON. FOR TONIGHT...EXPECT A SMALL RIDGE TO VALLEY SPLIT
TO SET UP AHEAD OF A DEVELOPING WARM FRONT WITH PATCHY VALLEY FOG
AROUND...SIMILAR TO THIS MORNING. A FEW LIGHT SHOWERS CANNOT BE
RULED OUT WITH THAT BOUNDARY THROUGH THE MORNING...ESPECIALLY EAST
BY MIDDAY SATURDAY. A COLD FRONT WILL THEN SETTLE SOUTH TOWARD
EASTERN KENTUCKY LATER SATURDAY. BETWEEN THESE FEATURES...OUR AREA
WILL BE IN THE WARM SECTOR OF A QUICK MOVING SFC LOW AND AS A
RESULT COULD SEE SOME CONVECTION DEVELOP WITH FAVORABLE PARAMETERS
FOR STRONG TO SEVERE STORMS BUILDING DURING THE AFTERNOON AND
INTO THE EVENING. SPECIFICALLY...CAPE WILL BE MODERATE WITH LOW
LIS AND VEERING/INCREASING WINDS WITH HEIGHT. WILL HIGHLIGHT THIS
FURTHER IN THE FORTHCOMING HWO WITH HAIL AND GUSTY WINDS THE MAIN
THREAT.
USED THE SHORTBLEND/SUPERBLEND AS A STARTING POINT FOR MOST
ELEMENTS WITH SOME MINOR ADJUSTMENTS TO THE AFTERNOON DEWPOINTS
AND SOME TERRAIN DIFFERENCES FOR TEMPERATURES TONIGHT. DID ADJUST
POPS TO BE A BIT ABOVE THE POPULATION SCHEME...IN THE EAST THROUGH
TODAY AND ALSO FOR THE STRONG/SEVERE STORM CONCERNS ON SATURDAY
AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 405 AM EDT FRI MAY 6 2016
THE EXTENDED PORTION OF THE FORECAST BEGINS SATURDAY NIGHT WITH AN
ACTIVE PATTERN IN PLACE. UPPER CLOSED LOW OVER THE SOUTHEASTERN
CANADA REGION WILL BE IN PLACE THROUGH THE WEEKEND AS IT SLOWLY
SHIFTS EAST INTO THE COMING WEEK. THIS FEATURE CONTINUES TO SWING A
FEW SHORTWAVES INTO THE LOWER GREAT LAKES REGION THROUGH THE START
OF THE NEW WEEK. MEANWHILE...AS A WEAKENING RIDGE OVER THE SOUTHEAST
CONTINUES TO WEAKEN AND SHIFT EAST AS WELL WITH ANOTHER UPPER LEVEL
LOW OVER THE CENTRAL PLAINS. THIS FEATURE OPENS AND EJECTS EAST INTO
THE OHIO VALLEY BY MID WEEK. FOLLOWING THIS...TOWARDS THE END OF THE
EXTENDED PERIOD...THE PATTERN BECOMES MORE AMPLIFIED AS ANOTHER
UPPER LOW MOVES INTO THE UPPER PLAINS WITH A WEAKENING RIDGE OVER
THE OH VALLEY SHIFTING. OVERALL...BOTH THE GFS AND EURO HAVE A
DECENT HANDLE ON THE UPPER LEVEL PATTERN THROUGH NEXT WEEK. THOUGH
THE GFS IS A BIT MORE DRIER THAN THE EURO...THE BOTTOM LINE IS THAT
THE EXTENDED SEEMS QUITE WET AND ACTIVE. THIS SOLUTION IS ALSO
CONFIRMED BY THE ALL MODEL BLEND AS WELL KEEPING THE CHANCE OF
PRECIP THROUGH JUST ABOUT EVERY DAY OF THE EXTENDED.
NEAR THE SURFACE HEADING INTO SATURDAY NIGHT AND SUNDAY...A SURFACE
LOW PRESSURE SYSTEM DEVELOPING UP OVER THE CENTRAL PLAINS SETS UP A
WARM FRONT INTO THE MIDWEST AND A QUASI STATIONARY BOUNDARY INTO
THE OH VALLEY. THIS BOUNDARY BECOMES A FOCUS FOR CONTINUED
CONVECTION SATURDAY NIGHT AND SUNDAY. IN FACT...THE EURO MIGHT
SUGGEST AN MCS SET UP FOR THIS TIME PERIOD. INSTABILITY AND SHEAR
SEEM SUBSTANTIAL FOR ORGANIZED CONVECTION AT LEAST EARLY IN THE
SATURDAY NIGHT PERIOD AND AGAIN SUNDAY AFTERNOON FOCUSING ON MAX
HEATING. STRONG CAPPING HEADING INTO THE DAY MONDAY WOULD LIMIT
CONVECTION A BIT MORE AS THE MENTIONED BOUNDARY LIFTS NORTH. STILL
WILL KEEP LOW CHANCE POPS IN THE NORTH CLOSER TO THE BOUNDARY.
TUESDAY...THE SYSTEM OUT WEST SHIFTS EAST WITH STRONG UPPER LEVEL
SUPPORT. STRONG CONVECTION SEEMS TO DEVELOP AHEAD OF THE COLD FRONT
TUESDAY AFTERNOON INTO TUESDAY NIGHT. THIS WILL KEEP LIKELY POPS IN
THE FORECAST THROUGH WEDNESDAY AS GFS MODEL SOUNDINGS KEEP GOOD
INSTABILITY IN PLACE TUESDAY AND WEDNESDAY AFTERNOON. IN FACT...THIS
SYSTEM WILL BE FOLLOWED BY A DISTURBANCE TO MOVE INTO THE AREA ON
THURSDAY. MODELS HIGHLIGHT AN ACTIVE EXTENDED FORECAST THROUGH NEXT
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 115 AM EDT FRI MAY 6 2016
THE WORST OF THE AVIATION CONDITIONS WILL BE THROUGH THE REST OF
THE NIGHT AS SCATTERED SHOWERS DRIFT JUST WEST OF SOUTH THROUGH
THE FAR EASTERN PARTS OF THE AREA. THESE LOCATIONS...PRIMARILY
SJS...WILL SEE THE BEST SHOT AT MVFR CONDITIONS FOR BOTH VIS AND
CIGS WITH ANY SHOWER. ELSEWHERE...PATCHY FOG MAY IMPACT A TAF SITE
OR TWO WEST OF THE AREA OF SHOWERS...BUT FOR THE MOST PART VFR
CONDITIONS WILL PREVAIL. THROUGH THE DAY FRIDAY AND INTO THE
EVENING VFR WILL HOLD AS HIGH PRESSURE MAKES ITS INFLUENCE KNOWN.
WINDS THROUGH THE PERIOD WILL BE GENERALLY BETWEEN 5 AND 10 KTS
FROM THE NORTHWEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
135 AM EDT FRI MAY 6 2016
.UPDATE...
ISSUED AT 135 AM EDT FRI MAY 6 2016
DID A QUICK UPDATE TO FINE TUNE THE GRIDS THROUGH DAYBREAK PER
THE LATEST SHORTBLEND GUIDANCE...OBS...AND TRENDS. ALSO ADDED A
TOUCH OF PATCHY FOG TO THE WX GRIDS. THESE HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1007 PM EDT THU MAY 5 2016
RECENT RADAR TRENDS INDICATE THAT THE RAIN SHOWERS WILL CONTINUE
TO EXPERIENCE OVERNIGHT WILL NOT SPREAD QUITE AS FAR WESTWARD...OR
BE QUITE AS WIDESPREAD...AS PREVIOUSLY FORECAST. THEREFORE...THE
HOURLY FORECAST GRIDS THROUGH 12Z FRIDAY HAVE BEEN UPDATED TO
REFLECT THESE LATEST TRENDS. AN UPDATED ZONE FORECAST TEXT
PRODUCT HAS BEEN ISSUED AS WELL. THE REST OF THE FORECAST IS IN
GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 325 PM EDT THU MAY 5 2016
WV SAT AND HRRR HAS SUGGESTED THAT THE UPPER LEVEL CLOSED LOW HAS
PROGRESSED SOUTHEAST INTO WESTERN NC AND NW SC. OVERALL THE MESO
MODELS AND MORE SYNOPTIC MODELS HAVE HAD A DECENT HANDLE ON THIS
PROGRESSION. WE CONTINUE TO HAVE SOME SHOWERS THAT HAVE DEVELOPED
ACROSS THE SOUTH AND SW PORTIONS OF THE CWA. THIS HAS BEEN DUE TO
THE STEEPER LOW LEVEL LAPSE RATES...AS WE HAVE SEEN BREAKS IN THE
CLOUDS. THESE LAPSE RATES ARE COMBINING WITH THE ALREADY
REASONABLY STEEP MID LEVEL LAPSE RATES. OVERALL COVERAGE HAS BEEN
SCATTERED WITH BETTER COVERAGE TO THE SOUTH AND EAST. RIGHT NOW
MODELS DO WANT TO BRING ADDITIONAL SHOWERS IN THE FAR EAST THIS
EVENING AND TONIGHT...HOWEVER BIGGEST QUESTION WOULD BE HOW MUCH
COVERAGE DO WE SEE. RIGHT NOW OPTED TO LOWER POPS GIVEN SOME OF
THE UNCERTAINTY. THIS UNCERTAINTY COMES WHEN LOOKING UPSTREAM
RADAR COVERAGE IS QUITE LOW COMPARED TO WHAT MAY HAVE BEEN
PREVIOUSLY THOUGHT AND CAMS ARE NOT HITTING IT TOO HARD EITHER.
THE OTHER QUESTION WOULD BE HOW MUCH CLOUD COVER DO WE SEE
TONIGHT...RIGHT NOW KEEP CLOUD COVER HIGHER IN THE EAST GIVEN THE
BETTER SHOWER COVERAGE. ALSO COULD HAVE IMPLICATIONS ON TEMPS AND
FOG POTENTIAL. RIGHT NOW WILL ADD SOME PATCHY DEEPER VALLEY FOG
AND JUST MINOR TEMP SPLIT GIVEN THE CLOUD UNCERTAINTY.
THIS UPPER LOW IS FAIRLY SLOW TO MOVE EAST...AS A OMEGA BLOCK
PATTERN SETS UP ACROSS THE CENTRAL PART OF THE CONUS. THEREFORE
SURFACE HIGH PRESSURE WILL BE SLOW TO BUILD NORTHEAST FROM THE
GULF. THAT SAID THERE WAS A NEED FOR SHOWERS IN THE FAR EAST AND
SOUTHEAST FOR FRIDAY GIVEN THE SLOW PROGRESS OF VERTICALLY STACKED
LOW AND CONTINUED PVA/SHORTWAVES DIVING SOUTH. NOW FRIDAY NIGHT
HEIGHTS WILL CONTINUE TO RISE AS UPPER LOW/OMEGA BLOCK BREAK DOWN
AND PROGRESS EAST. THERE IS A WEAK SURFACE TROUGH OR WAVE MAY
BRING SOME SLIGHT CHANCE SHOWERS TO THE FAR NORTH OVERNIGHT.
OTHERWISE MOST SPOTS SHOULD DRY OUT AT THIS POINT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 353 PM EDT THU MAY 5 2016
MODELS ARE IN REASONABLY GOOD AGREEMENT WITH AN OMEGA BLOCK PATTERN
DEAMPLIFYING OVER THE WEEKEND AND EVOLVING TO MORE OR LESS A SPLIT
FLOW PATTERN NEXT WEEK. THE CURRENT UPPER LEVEL SYSTEM MEANDERING OF
THE APPALACHIANS AND THE SOUTHEAST IS EXPECTED TO SHIFT OFF THE
EASTERN SEABOARD. AT THE SAME TIME...AN UPPER LEVEL LOW WILL MOVE
FROM THE HUDSON AND JAMES BAY REGION INTO ONTARIO AND QUEBEC AND
THEN INTO THE CANADIAN OVER THE WEEKEND AND INTO EARLY NEXT WEEK. A
SHORTWAVE TROUGH IS EXPECTED TO MOVE THROUGH THE GREAT LAKES REGION
EARLY IN THE PERIOD AND INTO THE NORTHEASTERN CONUS BY THE END OF
THE WEEKEND. THIS WILL SEND A COLD FRONT INTO THE OHIO VALLEY AND
APPALACHIAN REGION FROM LATE SATURDAY INTO SATURDAY NIGHT...WITH THE
BOUNDARY STALLING OUT LATE IN THE WEEKEND ACROSS THE OHIO OR
TENNESSEE VALLEY. THE MODEL CONSENSUS IS FOR A SMALL CHANCE OF
CONVECTION ON ISENTROPIC LIFT EARLY IN THE PERIOD ON SATURDAY. A
LULL IN ACTIVITY IS POSSIBLE FROM MIDDAY INTO THE AFTERNOON ON
SATURDAY...WITH MORE ORGANIZED CONVECTION LIKELY SATURDAY EVENING
INTO SATURDAY NIGHT. CHANCES FOR CONVECTION APPEAR TO LESSEN ON
SUNDAY AS THE SHORTWAVE TROUGH DEPARTS TO THE EAST AND NORTHEAST.
AN AREA OF SFC LOW PRESSURE MEANWHILE WILL BEGIN TO DEVELOP OVER THE
WEEKEND IN THE LEE OF THE ROCKIES AHEAD OF THE SECOND UPPER LEVEL
LOW MEANDERING FROM THE SOUTHWESTERN CONUS INTO THE ROCKIES OVER THE
WEEKEND AND EVENTUALLY EJECTING INTO THE PLAINS. IN RESPONSE TO THE
DEVELOPING LOW AND HEIGHT RISES OVER THE SOUTHEASTERN CONUS...THE
STATIONARY FRONT SHOULD RETURN NORTH AS A WARM FRONT MONDAY INTO
MONDAY NIGHT. EVEN AS THE REGION GETS INTO THE WARM SECTOR
CONVECTION CANNOT BE RULED OUT AT ANY POINT ON MONDAY. THE SFC LOW
PRESSURE SYSTEM SHOULD GRADUALLY TRACK FROM THE PLAINS TOWARD THE
GREAT LAKES REGION AT MIDWEEK AND THEN EVENTUALLY INTO THE
NORTHEASTERN CONUS. MODEL AGREEMENT FROM RUN TO RUN AND MODEL TO
MODEL IN THESE DETAILS DIMINISHES GREATLY BY TUESDAY AND TUESDAY
NIGHT AND ALSO CONFIDENCE IN ANY DETAILS. HOWEVER...THE OVERALL
MODEL BLEND AND CONSENSUS APPEARS TO BE FOR ANOTHER PEAK IN
CONVECTION CHANCES FROM LATE MONDAY NIGHT OR TUESDAY INTO THE DAY ON
WEDNESDAY AS SEVERAL SHORTWAVES SHOULD MOVE THROUGH THE OHIO VALLEY
AND GREAT LAKES REGION. LOCALLY HEAVY RAIN COULD BECOME A CONCERN
IN LOCATIONS THAT EXPERIENCE MULTIPLE ROUNDS OF CONVECTION.
TEMPERATURES SHOULD AVERAGE ABOVE NORMAL IN THE WARM SECTOR TO START
THE PERIOD...ALTHOUGH TEMPERATURES SHOULD BE SUPPRESSED ON SUNDAY
AND SUNDAY NIGHT WITH THE FRONT ACROSS THE AREA AND ABUNDANT CLOUD
COVER ANTICIPATED. THEREAFTER...TEMPERATURES SHOULD AVERAGE A BIT
ABOVE NORMAL THROUGH THE REST OF THE PERIOD...WITH HIGHS IN THE MID
70S TO AROUND 80 AND LOWS IN THE UPPER 50S TO AROUND 60.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 115 AM EDT FRI MAY 6 2016
THE WORST OF THE AVIATION CONDITIONS WILL BE THROUGH THE REST OF
THE NIGHT AS SCATTERED SHOWERS DRIFT JUST WEST OF SOUTH THROUGH
THE FAR EASTERN PARTS OF THE AREA. THESE LOCATIONS...PRIMARILY
SJS...WILL SEE THE BEST SHOT AT MVFR CONDITIONS FOR BOTH VIS AND
CIGS WITH ANY SHOWER. ELSEWHERE...PATCHY FOG MAY IMPACT A TAF SITE
OR TWO WEST OF THE AREA OF SHOWERS...BUT FOR THE MOST PART VFR
CONDITIONS WILL PREVAIL. THROUGH THE DAY FRIDAY AND INTO THE
EVENING VFR WILL HOLD AS HIGH PRESSURE MAKES ITS INFLUENCE KNOWN.
WINDS THROUGH THE PERIOD WILL BE GENERALLY BETWEEN 5 AND 10 KTS
FROM THE NORTHWEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...JP
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
249 AM EDT FRI MAY 6 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 354 PM EDT THU MAY 5 2016
12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW A NNW FLOW ALOFT
DOMINATING THE WRN GREAT LKS BTWN DEEP UPR TROF OVER THE E AND AN
UPR RDG IN CENTRAL NAMERICA. A SFC HI PRES RDG STRETCHING FM THE UPR
MIDWEST INTO WRN QUEBEC AS WELL AS DRY AIRMASS SHOWN ON THE 12Z GRB
RAOB IS BRINGING A MOSUNNY DAY TO UPR MI...BUT MORE MAINLY MID/HI
CLDS RELATED TO WAA IN THE SW FLOW ON THE BACK SIDE OF THE RDG ARE
PRESENT FM WRN LK SUP INTO CENTRAL ONTARIO. THERE WERE SOME SHOWERS
UNDER THESE CLDS OVER MN WHERE MID LVL LAPSE RATES HAVE BEEN
STEEPER...BUT ABSENCE OF FORCING OTHER THAN WAA AND RELATIVELY DRY
NATURE OF THE AIRMASS ARE LIMITING THE COVERAGE OF THIS PCPN...WITH
A DIMINISHING TREND IN RECENT HRS.
TNGT...AS SFC HI PRES RDG CONTINUES TO SLIDE SEWD...SW FLOW/WAA ARE
PROGGED TO DOMINATE THE CWA. EXPECT SOME MID/HI CLDS RELATED TO THIS
WAA TO PASS OVER THE CWA MAINLY THRU 06Z BEFORE SUBSIDENCE RELATED
TO SHARPENING H7 RDG AXIS DRIES UP THESE CLDS. CONSIDERED ADDING
SOME ISOLD SHOWERS LATE THIS AFTN/THIS EVNG OVER THE FAR W WHERE NAM
SHOWS POCKET OF H7-5 LAPSE RATES ARND 8C/KM AND SOME OF THE HIER RES
MODELS GENERATE SPOTTY QPF...BUT LATEST RADAR TRENDS SUG THE AIRMASS
IS SO DRY IN A RELATIVE SENSE THAT THE DRY FCST GUIDANCE IS ON THE
RIGHT TRACK. COMBINATION OF THE WAA CLDS AND LLVL WARMING RELATED TO
STEADY SW FLOW WL HOLD MIN TEMPS UP MUCH HIER THAN THIS MRNG. IN
FACT...READINGS MAY NOT FALL BLO 50 OVER THE FAR W FM IRONWOOD TO
ONTONAGON WHERE THE SW FLOW WL DOWNSLOPE.
FRI...UPR MI WL BE IN THE WARM SECTOR BTWN DEPARTING SFC HI PRES RDG
TO THE SE AND SFC LO PRES TRACKING ACROSS NW ONTARIO AHEAD OF SHRTWV
MOVING OVER WRN RDG AND INTO FAR NW ONTARIO LATE IN THE DAY. WITH
H85 TEMPS FCST AS HI AS 18C AND A GOOD DEAL OF SUNSHINE WITHIN
LINGERING DRY AIRMASS...TEMPS AWAY FM THE MODERATING INFLUENCE OF
MAINLY LK MI OVER THE W HALF WL RISE WELL INTO THE 80S AND PERHAPS
ARPCH 90 AT A FEW LOCATIONS. WITH DAYTIME MIXING CAUSING SFC DEWPTS
TO DROP AT LEAST CLOSE TO 40 IN THE AFTN...EXPECT MIN RH TO DIP NEAR
20 PCT AT A FEW PLACES. ALTHOUGH STRONG WINDS ARE NOT EXPECTED WITH
GUSTS UP TO ARND 20 MPH...FIRE WX CONCERNS WL BE ELEVATED. WINDS WL
BE A BIT STRONGER OVER THE E...BUT MODERATION OFF LK MI WL LIMIT
FIRE WX CONCERNS THERE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 249 AM EDT FRI MAY 6 2016
UPPER AIR PATTERN CONSISTS OF A CLOSED 500 MB LOW OVER THE ROCKIES
AND ANOTHER OVER THE ERN U.S. AND ANOTHER NEAR HUDSON BAY IN A
RATHER BLOCKY PATTERN 12Z SAT. THE HUDSON BAY CLOSED LOW HAS A
TROUGH THAT IS MOVING THROUGH THE UPPER GREAT LAKES ON SAT. THIS
TROUGH THEN MOVES INTO NEW ENGLAND ON SUN. THE CLOSED 500 MB LOW
MOVES INTO THE CENTRAL PLAINS 12Z MON. IN SPITE OF THE UPPER
LEVELS...LOOKS PRETTY DRY OVERALL AND QUIET.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB CLOSED LOW OVER THE
CENTRAL PLAINS 12Z MON AND TROUGHING ACROSS SW CANADA WITH A RIDGE
OVER THE NORTHERN PLAINS AND INTO THE CANADIAN PRAIRIES AND A TROUGH
IN ERN CANADA. UPPER PATTERN DOES NOT CHANGE MUCH FOR 12Z TUE.
BLOCKY PATTERN CONTINUES FOR 12Z WED WITH OMEGA BLOCK OVER THE UPPER
GREAT LAKES WITH TROUGHING IN THE ROCKIES AND A TROUGH OVER THE
UPPER GREAT LAKES. TROUGHING MOVES INTO THE NORTHERN PLAINS 12Z THU
WITH RIDGING OVER THE UPPER GREAT LAKES. TEMPERATURES LOOK TO BE
NEAR NORMAL FOR THIS FORECAST PERIOD AND GENERALLY LOOKS QUIET AS
POPS LOOK TO STAY MOSTLY SOUTH OF THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 135 AM EDT FRI MAY 6 2016
VFR CONDITIONS WILL PREVAIL THRU THIS AFTN AT KIWD/KCMX/KSAW AS A
DRY AIR MASS WILL LINGER DESPITE HIGH PRES EXITING AND A COLD FRONT
APPROACHING. MARGINAL LLWS IS EXPECTED THRU THE REMAINDER OF TONIGHT
AT KIWD/KSAW WITH STRONGER WINDS NOTED ABOVE NOCTURNAL INVERSION PER
KMQT/KDLH VAD WIND PROFILES AND MODEL FCSTS. COLD FRONT WILL SWEEP
ACROSS THE AREA LATE THIS EVENING AND OVERNIGHT...BRINGING A WSHFT TO
THE N AND PERHAPS A FEW SHRA. COVERAGE SHOULD BE SOMEWHAT
LIMITED...SO MOSTLY A VCSH WAS UTILIZED IN FCST. MIGHT BE A BRIEF
PERIOD OF MVFR CONDITIONS IF A SHRA DOES AFFECT ANY OF THE TERMINALS.
A BRIEF PERIOD OF LLWS WILL BE POSSIBLE AT KIWD AND KCMX AT THE END
OF THE PERIOD AS LOW-LEVEL MARINE AIR BEHIND THE FRONT STABILIZES THE
NEAR SFC LAYER.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EDT THU MAY 5 2016
SSW WINDS UP TO 20 KTS AHEAD OF AN APPROACHING COLD FRONT WILL SHIFT
TO THE N AT 20-25 KTS FRI NIGHT INTO SAT FOLLOWING THE PASSAGE OF
THIS BOUNDARY. AS HI PRES BUILDS OVER THE AREA BY LATE IN THE
WEEKEND...THESE WINDS WILL DIMINISH UNDER 15-20 KTS INTO EARLY NEXT
WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...ROLFSON/KLUBER
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
138 AM EDT FRI MAY 6 2016
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 354 PM EDT THU MAY 5 2016
12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW A NNW FLOW ALOFT
DOMINATING THE WRN GREAT LKS BTWN DEEP UPR TROF OVER THE E AND AN
UPR RDG IN CENTRAL NAMERICA. A SFC HI PRES RDG STRETCHING FM THE UPR
MIDWEST INTO WRN QUEBEC AS WELL AS DRY AIRMASS SHOWN ON THE 12Z GRB
RAOB IS BRINGING A MOSUNNY DAY TO UPR MI...BUT MORE MAINLY MID/HI
CLDS RELATED TO WAA IN THE SW FLOW ON THE BACK SIDE OF THE RDG ARE
PRESENT FM WRN LK SUP INTO CENTRAL ONTARIO. THERE WERE SOME SHOWERS
UNDER THESE CLDS OVER MN WHERE MID LVL LAPSE RATES HAVE BEEN
STEEPER...BUT ABSENCE OF FORCING OTHER THAN WAA AND RELATIVELY DRY
NATURE OF THE AIRMASS ARE LIMITING THE COVERAGE OF THIS PCPN...WITH
A DIMINISHING TREND IN RECENT HRS.
TNGT...AS SFC HI PRES RDG CONTINUES TO SLIDE SEWD...SW FLOW/WAA ARE
PROGGED TO DOMINATE THE CWA. EXPECT SOME MID/HI CLDS RELATED TO THIS
WAA TO PASS OVER THE CWA MAINLY THRU 06Z BEFORE SUBSIDENCE RELATED
TO SHARPENING H7 RDG AXIS DRIES UP THESE CLDS. CONSIDERED ADDING
SOME ISOLD SHOWERS LATE THIS AFTN/THIS EVNG OVER THE FAR W WHERE NAM
SHOWS POCKET OF H7-5 LAPSE RATES ARND 8C/KM AND SOME OF THE HIER RES
MODELS GENERATE SPOTTY QPF...BUT LATEST RADAR TRENDS SUG THE AIRMASS
IS SO DRY IN A RELATIVE SENSE THAT THE DRY FCST GUIDANCE IS ON THE
RIGHT TRACK. COMBINATION OF THE WAA CLDS AND LLVL WARMING RELATED TO
STEADY SW FLOW WL HOLD MIN TEMPS UP MUCH HIER THAN THIS MRNG. IN
FACT...READINGS MAY NOT FALL BLO 50 OVER THE FAR W FM IRONWOOD TO
ONTONAGON WHERE THE SW FLOW WL DOWNSLOPE.
FRI...UPR MI WL BE IN THE WARM SECTOR BTWN DEPARTING SFC HI PRES RDG
TO THE SE AND SFC LO PRES TRACKING ACROSS NW ONTARIO AHEAD OF SHRTWV
MOVING OVER WRN RDG AND INTO FAR NW ONTARIO LATE IN THE DAY. WITH
H85 TEMPS FCST AS HI AS 18C AND A GOOD DEAL OF SUNSHINE WITHIN
LINGERING DRY AIRMASS...TEMPS AWAY FM THE MODERATING INFLUENCE OF
MAINLY LK MI OVER THE W HALF WL RISE WELL INTO THE 80S AND PERHAPS
ARPCH 90 AT A FEW LOCATIONS. WITH DAYTIME MIXING CAUSING SFC DEWPTS
TO DROP AT LEAST CLOSE TO 40 IN THE AFTN...EXPECT MIN RH TO DIP NEAR
20 PCT AT A FEW PLACES. ALTHOUGH STRONG WINDS ARE NOT EXPECTED WITH
GUSTS UP TO ARND 20 MPH...FIRE WX CONCERNS WL BE ELEVATED. WINDS WL
BE A BIT STRONGER OVER THE E...BUT MODERATION OFF LK MI WL LIMIT
FIRE WX CONCERNS THERE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 319 PM EDT THU MAY 5 2016
LONG TERM STARTS AT 00Z SAT WITH THE UPPER RIDGE AND WARM AIRMASS
OVER THE REGION. 850MB TEMPS WILL BE AROUND 17C AT 00Z...BUT WILL
DROP TO 1-2C BY 18Z SAT BEHIND A SHORTWAVE TROUGH AND COLD FRONT.
MODELS CONTINUE TO PAINT UP TO 0.20 INCHES OF QPF OVER MUCH OF THE
AREA FRI NIGHT...BETWEEN 00Z AND 12Z SAT...BUT SOME AREAS MAY NOT
EVEN SEE 0.10 INCHES. EXPECT THUNDERSTORMS AS ELEVATED INSTABILITY
(CAPE UP TO 750 J/KG)...BUT NO SEVERE THUNDERSTORMS DUE TO WEAK
SHEAR (0-6KM BULK SHEAR AROUND 20KTS).
DRY AIR MOVES BACK IN ON SAT WITH SUNNY SKIES AND MIN RH VALUES IN
THE MID 20S OVER THE INTERIOR W AROUND AROUND 40 PERCENT INTERIOR E.
WINDS WILL BE LIGHT OVER THE W AND WILL GUST UP TO 25 MPH OVER THE
E. IT WILL BE COOLER WITH HIGHS IN THE 50S NEAR LAKE SUPERIOR AND E
AND AROUND 60 INTERIOR W. CERTAINLY NOT A CRITICAL FIRE WEATHER DAY
BUT THE DRY AIR WILL PROBABLY NEGATE ANY MOISTURE WE GET FRI NIGHT.
CAN NOT COMPLETELY RULE OUT A FEW LIGHT SHOWERS OVER NORTHERN LAKE
SUPERIOR AND POSSIBLY THE KEWEENAW AND ERN UPPER MI SAT EVENING INTO
SAT NIGHT AS ANOTHER SHORTWAVE PASSES N OF THE AREA...BUT THINK
POTENTIAL IS LOW ENOUGH TO LEAVE OUT OF THE FORECAST FOR LAND AREAS.
SUN WILL SEE SIMILAR TEMPS/RH/CLOUDS TO SAT...BUT WITH LOWER WINDS.
MON AND TUE HAD APPEARED WET FROM EARLIER MODEL RUNS...BUT THOSE
MODELS HAVE TRENDED DRIER. NOW ONLY THE 00Z/05 ECMWF SHOWS PRECIP
OVER THE CWA...EXCEPT THE GLOBAL GEM WHICH HAS PRECIP BRUSHING SRN
MENOMINEE COUNTY. WILL ACCORDINGLY START A DECREASING TREND FOR THE
POP FORECAST FOR MON THROUGH TUE. NO PRECIP EXPECTED TUE NIGHT
THROUGH THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 135 AM EDT FRI MAY 6 2016
VFR CONDITIONS WILL PREVAIL THRU THIS AFTN AT KIWD/KCMX/KSAW AS A
DRY AIR MASS WILL LINGER DESPITE HIGH PRES EXITING AND A COLD FRONT
APPROACHING. MARGINAL LLWS IS EXPECTED THRU THE REMAINDER OF TONIGHT
AT KIWD/KSAW WITH STRONGER WINDS NOTED ABOVE NOCTURNAL INVERSION PER
KMQT/KDLH VAD WIND PROFILES AND MODEL FCSTS. COLD FRONT WILL SWEEP
ACROSS THE AREA LATE THIS EVENING AND OVERNIGHT...BRINGING A WSHFT TO
THE N AND PERHAPS A FEW SHRA. COVERAGE SHOULD BE SOMEWHAT
LIMITED...SO MOSTLY A VCSH WAS UTILIZED IN FCST. MIGHT BE A BRIEF
PERIOD OF MVFR CONDITIONS IF A SHRA DOES AFFECT ANY OF THE TERMINALS.
A BRIEF PERIOD OF LLWS WILL BE POSSIBLE AT KIWD AND KCMX AT THE END
OF THE PERIOD AS LOW-LEVEL MARINE AIR BEHIND THE FRONT STABILIZES THE
NEAR SFC LAYER.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 PM EDT THU MAY 5 2016
SSW WINDS UP TO 20 KTS AHEAD OF AN APPROACHING COLD FRONT WILL SHIFT
TO THE N AT 20-25 KTS FRI NIGHT INTO SAT FOLLOWING THE PASSAGE OF
THIS BOUNDARY. AS HI PRES BUILDS OVER THE AREA BY LATE IN THE
WEEKEND...THESE WINDS WILL DIMINISH UNDER 15-20 KTS INTO EARLY NEXT
WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON/KLUBER
MARINE...KC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1238 AM CDT FRI MAY 6 2016
.UPDATE...
ISSUED AT 1237 AM CDT FRI MAY 6 2016
MAIN CONCERN THIS UPDATE IS ARRIVAL OF THE COLD FRONT JUST ENTERING
NORTHWESTERN NORTH DAKOTA. LOOKING LIKE WINDS BECOME
NORTHWESTERLY...BUT DO NOT BEGIN INCREASING FOR A FEW HOURS BEHIND
THE FRONTAL PASSAGE. STILL SOME AREAS IN SASKATCHEWAN WITH REDUCED
VISIBILITY - LIKELY DUE TO SMOKE FROM LARGE FIRES IN NORTHERN
ALBERTA/SASKATCHEWAN. SWIFT CURRENT HAD BEEN REPORTING VISIBILITIES
OF 2-3 MILES BUT NOT SEEING OTHER SURROUNDING STATIONS WITH
VISIBILITY REDUCTIONS. WILL BE MONITORING FOR FUTURE UPDATES.
OTHERWISE BLENDED CURRENT OBSERVATIONS WITH TEMPERATURE TRENDS AND
NO BIG CHANGES FOR THE OVERNIGHT HOURS.
UPDATE ISSUED AT 943 PM CDT THU MAY 5 2016
MOST OF THE CUMULUS AND ISOLATED...HIGH-BASED SHOWERS /AND A LONE
STORM THAT OCCURRED IN WILLIAMS COUNTY EARLIER/ ARE DIMINISHING
WITH THE ONSET OF NOCTURNAL COOLING AND STABILIZATION. THAT IS IN
LINE WITH OUR LATE AFTERNOON FORECAST UPDATE. THE MAIN QUESTION
GOING FORWARD WILL BE WHAT /IF ANY/ SHOWER POTENTIAL EXISTS OVER-
NIGHT. RECENT OPERATIONAL HRRR SIMULATIONS CONTINUE TO BE TOO
AGGRESSIVE WITH CONVECTIVE DEVELOPMENT COMPARED TO REALITY...AND
THE 18 UTC GFS AND 00 UTC NAM ARE AT ODDS OVER SHOWER POTENTIAL.
THAT PROVIDED LOW ENOUGH CONFIDENCE FOR US TO KEEP A DRY FORECAST
GOING OVERNIGHT...THOUGH THAT WILL NEED TO BE RE-EVALUATED LATER.
THE ONE CHANGE WE DID MAKE WITH THIS UPDATE WAS TO INCREASE LOWS
BY 2-4 F IN MOST AREAS BASED ON MID-EVENING TEMPERATURE TRENDS.
FINALLY...ONE OTHER ISSUE THAT WE WILL NEED TO CONTEND WITH FOR
LATER FORECAST RELEASES IS HOW THICK SMOKE FROM CANADIAN FIRES MAY
BE FRIDAY. OBSERVATIONS IN SASKATCHEWAN HAVE SHOWN VISIBILITIES
AS LOW AS 4SM FOR SEVERAL HOURS BEHIND THE COLD FRONT THAT WILL
CROSS THE AREA. THUS...IT/S POSSIBLE THICKER LOW-LEVEL SMOKE MAY
IMPACT PARTS OF WESTERN AND CENTRAL ND LATE TONIGHT AND FRIDAY.
AT THE VERY LEAST IT SEEMS REASONABLE TO BELIEVE THE SMOKE WILL BE
SENSIBLE VIA SMELL FRIDAY.
UPDATE ISSUED AT 755 PM CDT THU MAY 5 2016
WE WILL LET THE RED FLAG WARNING EXPIRE AS SCHEDULED AT 8 PM CDT
/01 UTC/...AS WINDS IN EAST CENTRAL ND HAVE DIMINISHED TO AROUND
10 MPH. HUMIDITIES ARE AT OR ABOVE 20 PERCENT AS OF 0050 UTC AND
THEY WILL CONTINUE A SLOW RISE WITH THE ONSET OF DIURNAL COOLING.
UPDATE ISSUED AT 551 PM CDT THU MAY 5 2016
WE HAVE ADDED A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM TO THE
FORECAST THROUGH MID EVENING IN NORTHWEST ND. A HIGH-BASED SHOWER
DEVELOPED NORTHWEST OF WILLISTON NEAR 2230 UTC...AND EVEN THOUGH
THE ENTLN TOTAL LIGHTNING PLOT HAS NOT YET SHOWN ANY IN-CLOUD OR
CLOUD-TO-GROUND STRIKES...THE STEEP LAPSE RATES AND WEAK MLCAPE
/UP TO 250 J/KG PER THE SPC MESOANALYSIS/ IN THAT AREA SUGGEST A
RUMBLE OR TWO OF THUNDER IS POSSIBLE. VISIBLE SATELLITE IMAGERY
THROUGH 2245 UTC SHOWS CUMULUS ALL ALONG A WEAK SURFACE PRESSURE
TROUGH EXTENDING FROM SOUTHEAST SASKATCHEWAN INTO EASTERN MT SO IT
IS PLAUSIBLE MORE THAN JUST THAT INITIAL SHOWER MAY FORM. THAT
BEING SAID...RECENT HRRR RUNS ARE LIKELY OVERDONE WITH EXPECTED
DEVELOPMENT BASED ON THAT MODEL/S RECENT AND LONGER-TERM BIASES.
OTHERWISE...WE ARE CONTINUING THE RED FLAG WARNING IN EAST CENTRAL
ND FOR NOW GIVEN LATE-AFTERNOON OBSERVATIONS AND ONGOING FIRES.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 235 PM CDT THU MAY 5 2016
THE MAIN IMPACTS IN THE SHORT TERM ARE CRITICAL FIRE CONDITIONS
TODAY AND A COLD FRONT TOMORROW.
AN UPPER LEVEL RIDGE...COMBINED WITH A SURFACE TROUGH AND
SOUTHWESTERLY MIXING WINDS...HAVE ALLOWED TEMPERATURES THIS
AFTERNOON TO RISE RAPIDLY INTO THE 80S AND LOW 90S. THESE WARM
TEMPERATURES HAVE FURTHER EXACERBATED DRY BOUNDARY LAYER
CONDITIONS. WITH VERY DRY AIR MIXING DOWN RELATIVE HUMIDITY VALUES
HAVE PLUMMETED INTO THE TEENS AND LOW 20S. WIND SPEEDS HAVE BEEN A
BIT BREEZY ACROSS THE JAMES VALLEY. THIS IS WHAT PROMPTED THE
ISSUANCE OF THE RED FLAG WARNING. WIND SPEEDS AROUND 20
MPH...COMBINED WITH HUMIDITY 20 PERCENT OR LESS AND DRY FUELS IS
PRODUCING CRITICAL FIRE CONDITIONS ACROSS THE JAMES VALLEY.
A COLD FRONT WILL SWEEP THROUGH TONIGHT INTO FRIDAY MORNING. WINDS
WILL SHIFT OUT OF THE NORTH BETWEEN 20 AND 30 MPH. TOMORROW
AFTERNOON MINIMUM RELATIVE HUMIDITY AROUND 20 PERCENT IS EXPECTED
IN NORTHWEST AND PORTIONS OF NORTH CENTRAL NORTH DAKOTA BY LATE
AFTERNOON. HOWEVER...BY THIS TIME THE STRONGEST WINDS SHOULD HAVE
PASSED TO THE SOUTH. THEREFORE...THESE AREAS MAY ESCAPE CRITICAL
FIRE CONDITIONS. MODELS CONTINUE TO INDICATE A MAINLY DRY FRONTAL
PASSAGE...WITH A FEW ISOLATED SHOWERS POSSIBLE. HOWEVER...WITH A
PERSISTANT DRY BOUNDARY LAYER...THE LIKELIHOOD OF ANY
PRECIPITATION ACTUALLY REACHING THE GROUND IS RATHER MINIMAL.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 235 PM CDT THU MAY 5 2016
COOLER AIR WILL SETTLE INTO THE AREA THIS WEEKEND IN THE WAKE OF
FRIDAYS COLD FRONT. HOWEVER... PLEASANT TEMPERATURES ARE STILL
EXPECTED WITH HIGHS MAINLY IN THE 70S. DRY CONDITIONS WILL REMAIN.
CHANGES APPEAR ON THE HORIZON FOR THE START THE WORK WEEK AS
AN UPPER LOW CURRENTLY OFF THE CALIFORNIA COAST DEEPENS OVER THE
FOUR CORNERS REGION THIS WEEKEND AND LIFTS INTO THE PLAINS ON
MONDAY...BRINGING CHANCES FOR RAIN AND THUNDERSTORMS.
CHANCES FOR RAIN AND THUNDERSTORMS WILL LINGER OVER THE AREA
THROUGH THE WEEK AS THE GFS AND ECMWF HAVE THE LOW REMAINING
NEARBY THROUGH FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1237 AM CDT FRI MAY 6 2016
VFR CONDITIONS ARE FORECAST OVERNIGHT THROUGH FRIDAY...BUT THERE IS
A LOW PROBABILITY OF SUB-VFR SMOKE AFFECTING PARTS OF THE AREA. THE
MAIN AVIATION WEATHER ISSUE WILL BE A COLD FRONTAL PASSAGE THAT HAS
ARRIVED AT KISN...WHICH HAS SHIFTED WINDS TO THE NORTH. EXPECT WINDS
TO BEGIN INCREASING A FEW HOURS AFTER FRONTAL PASSAGE WITH NORTHERLY
WIND GUSTS TO AROUND 30 KT EXPECTED TO OCCUR FRIDAY LATE MORNING AND
AFTERNOON ACROSS ALL OF WESTERN AND CENTRAL ND.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...JV
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
150 AM EDT FRI MAY 6 2016
.SYNOPSIS...
UNSEASONABLY COOL AIR WILL CONTINUE TO FILTER IN FROM THE NORTHWEST
IN THE WAKE OF A COLD FRONT. THE WEATHER WILL REMAIN UNSETTLED AS A
DEEP UPPER LOW CENTER MOVES ACROSS THE CAROLINAS TONIGHT AND AWAY TO
THE NORTHEAST ON FRIDAY. ANOTHER FRONT IS EXPECTED TO STALL JUST TO
OUR NORTH ON SATURDAY AND SUNDAY. THE FRONT SHOULD LIFT BACK TO THE
NORTH ON MONDAY...AS HIGH PRESSURE OFF THE SOUTHEAST COAST EXPANDS
AND WARM SOUTHERLY FLOW RETURNS.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1015 PM EDT...ABUNDANT MOISTURE MOVING SOUTHWARD ALONG THE
SPINE OF THE MOUNTAINS IS ENCOUNTERING WET BULB PROFILES JUST COLD
ENOUGH ABOVE ABOUT 4000 FEET TO CHANGE THE PREDOMINANT PRECIPITATION
TYPE OVER TO SNOW. ALTHOUGH THERE ARE MODEL HINTS OF SLIGHT WARMING
OVERNIGHT...IF ALL OR MOST OF THE IMPENDING QPF IS PREDOMINATELY
SNOW AT THE HIGHER ELEVATIONS...ENOUGH ACCUMULATION SHOULD DEVELOP
FOR SLIPPERY ROADWAYS AND ASSOCIATED IMPACTS TO MANIFEST THEMSELVES.
A WINTER WEATHER ADVISORY HAS BEEN POSTED FOR AVERY AND MITCHELL
COUNTIES ABOVE 3500 FEET AT THIS POINT. THE ELEVATION DEPENDENCE
WILL BE STRONG...WITH MAINLY RAIN BELOW 3500 FEET...ABOUT AN INCH AT
3500 FEET RANGING UP TO SIX INCHES ABOVE 5000 FEET.
OTHERWISE...WATER VAPOR IMAGERY AND RAP 500 MB HEIGHTS CONTINUE TO
INDICATE THAT THE 546 DM LOW CENTER HAS MOVED EAST OF THE CLT METRO
AREA. MOISTURE AND SPOKES OF 500 MB VORTICITY CONTINUE TO ROTATE
SOUTH ACROSS THE FORECAST AREA AROUND THE BACK SIDE OF THE LOW
PRESSURE SYSTEM. THIS WILL LEAD TO FAIRLY HIGH COVERAGE OF LIGHT
RAIN/SHOWERS ACROSS THE NORTHERN TIER...WITH ELEVATIONS ABOVE ABOUT
4000 FEET COLD ENOUGH FOR SNOW AT TIMES IN THE NORTHERN MOUNTAINS.
SOME WARMING IS POSSIBLE OVERNIGHT. THE SHOWER COVERAGE WILL BE MUCH
SPOTTIER IN SOUTHERN SECTIONS WITH MAINLY PERIODS OF CLOUDS. THE LOW
WILL MOVE TOWARD THE CAROLINA COAST OVERNIGHT INTO FRIDAY...AND THE
BEST Q VECTOR CONVERGENCE WILL BE TO OUR EAST. THE SETUP WILL BE
SOMEWHAT SIMILAR ON FRIDAY...AS THE LOW REMAINS OVER THE
MID-ATLANTIC COAST. LAPSE RATES WILL BE SLIGHTLY POORER WITH THE
BETTER COLD AIR OFF TO THE EAST...BUT TEMPS/DEWPTS REBOUND BY 5-7
DEGREES...AND THESE SUGGEST SOME INSTABILITY WILL REDEVELOP. CHANCES
OVERALL ARE LESSER WITH MODEL QPF BEING LESS WIDESPREAD. BREEZY TO
WINDY CONDITIONS WILL RESULT WITH DEEP MIXING.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
AS OF 225 PM THURSDAY...ONE MORE POCKET OF COLD AIR ROTATES AROUND
THE UPPER LOW AND ACROSS THE AREA FRIDAY NIGHT BEFORE WARMER MID
LEVEL AIR MOVES IN ON SATURDAY. THIS WILL COMBINE WITH THE LINGERING
LOW LEVEL MOISTURE ACROSS THE MOUNTAINS TO KEEP ISOLATED TO
SCATTERED SHOWERS THERE DURING THE EVENING BEFORE ENDING BY
MIDNIGHT. A WEAK WARM FRONT TRAILING FROM A SURFACE LOW OVER THE
GREAT LAKES WILL BRUSH THE MOUNTAINS ON SATURDAY CREATING THE
POTENTIAL FOR ISOLATED SHOWERS. FINALLY...A BACK DOOR COLD FRONT
DROPS INTO THE AREA BY SUNDAY AS THE GREAT LAKES LOW MOVES EAST.
SOME WEAK SHORT WAVE ENERGY WILL CROSS THE AREA SATURDAY NIGHT AND
SUNDAY EVEN AS HEIGHTS RISE BETWEEN THE DEPARTING UPPER LOW AND A
RIDGE DEVELOPING OVER THE CENTRAL CONUS. BEST CHANCE FOR CONVECTION
WILL BE THE NORTHERN NC MOUNTAINS...WITH ISOLATED CONVECTION
POSSIBLE ACROSS THE I-40 CORRIDOR. TEMPS REBOUND TO NEAR NORMAL
LEVELS ON SATURDAY THEN RISE TO NEARLY 10 DEGREES ABOVE NORMAL ON
SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 245PM THURSDAY...THE EXTENDED PERIOD BEGINS SUNDAY NIGHT WITH
A STALLED FRONTAL BOUNDARY DRAPED W TO E ACROSS THE REGION
UNDERNEATH FAIRLY ZONAL FLOW ALOFT. THE BOUNDARY WILL RETREAT NORTH
AS A WARM FRONT AS SUBTROPICAL HIGH PRESSURE OVER THE SARGASSO SEA
INDUCES WARM SOUTHERLY FLOW ACROSS THE REGION BEGINNING MONDAY
AFTERNOON AND PERSISTING THROUGH AT LEAST WEDNESDAY. THE RETURN FLOW
WILL ALLOW TEMPERATURES TO QUICKLY REBOUND TO GENERALLY 5-10 DEGREES
ABOVE NORMAL THROUGH MID TO LATE WEEK. DEWPOINTS WILL GRADUALLY
RETURN TO THE UPPER 50S AND LOWER 60S DURING THIS TIME AS WELL AND
WITH THE INCREASING DIURNAL INSTABILITY...THERE IS A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY. THE ECMWF REMAINS LESS
OPTIMISTIC ABOUT COVERAGE THROUGH MID-WEEK WHILE THE GFS MAINTAINS
SCATTERED TO WIDESPREAD COVERAGE EACH AFTERNOON. THIS APPEARS
LARGELY TO BE THE RESULT OF STRONGER PERTURBATIONS IN THE WSW FLOW
ALOFT ENHANCING OVERALL FORCING IN THE GFS COMPARED TO THE FAIRLY
BENIGN ECMWF SOLUTION. THE FORECAST THEREFORE REFLECTS A BLEND OF
THE GUIDANCE AS THE PATTERN CERTAINLY WARRANTS SLIGHT CHANCE
COVERAGE EAST AND CHANCE COVERAGE WEST.
AN OPPORTUNITY EXISTS FOR MORE WIDESPREAD COVERAGE OF SHOWERS AND
STORMS WEDNESDAY EVENING INTO FRIDAY AS ANOTHER CLOSED LOW DROPS
INTO THE UPPER MIDWEST AND GREAT LAKES REGIONS AND A FEW LOBES OF
VORTICITY ROTATE AROUND THE BASE OF THE LOW ACROSS THE OH AND TN
VALLEYS AND INTO VIRGINIA AND THE CAROLINAS. HOWEVER...GIVEN THE
SOMEWHAT ANOMALOUS NATURE OF THIS PATTERN...AGAIN THE GUIDANCE
DIFFERS ON THE EXACT PLACEMENT AND EVOLUTION OF THE UPPER-LEVEL
FLOW. WHILE POPS INCREASE SLIGHTLY INTO LATE WEEK IN RESPONSE TO THE
ANTICIPATED BETTER FORCING ALOFT...THERE IS TOO MUCH UNCERTAINTY TO
WARRANT MORE AGGRESSIVE COVERAGE ATTM. FOR NOW...THESE FEATURES DO
LITTLE TO CHANGE THE ABOVE NORMAL TEMPERATURES WE EXPECT THROUGH THE
END OF NEXT WEEK.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...STILL SEEING SHOWERS WORKING THEIR WAY
ACROSS THE AREA ON THE BACK SIDE OF THE UPPER LOW. INCREASING
DOWNSLOPING COMPONENT WILL HELP TO DRY THINGS OUT...THOUGH EXPECT
SOME LINGERING VCSH OR -SHRA FOR A FEW HOURS STILL. BEST CHANCE FOR
MVFR CIGS REMAINS AT KHKY BUT FOR THE MOST PART EVERYONE SHOULD BE
VFR THROUGH THE PERIOD. CANNOT RULE OUT SOME -SHRA THIS AFTERNOON
BUT WITH THE UPPER LOW BEGINNING TO MOVE AWAY CHANCES DO NOT QUITE
SUPPORT PROB30...BUT WILL REEVALUATE FOR THE 12Z TAFS. OTHERWISE...
CONTINUED DEEP MIXING WITH STEEP LAPSE RATES WILL SUPPORT ANOTHER
ROUND OF GUSTY N/NNW WINDS TODAY...WITH PEAK GUSTS 20-30KT
ESPECIALLY TOWARD KAVL.
OUTLOOK...DRYING WILL CONTINUE INTO SATURDAY. A COLD FRONT WILL
APPROACH FROM THE NORTH SUNDAY...WITH ASSOCIATED PRECIPITATION
POSSIBLY APPROACHING KAVL TO KHKY BEFORE THE FRONT STALLS. WARMING
CONDITIONS WITH A RETURN TO SW FLOW ARE EXPECTED THROUGH EARLY NEXT
WEEK.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 99% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 94% HIGH 97% 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 SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WINTER WEATHER ADVISORY UNTIL NOON EDT TODAY FOR NCZ033-050.
SC...NONE.
&&
$$
SYNOPSIS...HG/JMP
NEAR TERM...HG
SHORT TERM...RWH
LONG TERM...JMP
AVIATION...TDP
AREA FORECAST DISCUSSION
NWS PORTLAND OR
207 AM PDT FRI MAY 6 2016
.SYNOPSIS...HIGH PRESSURE BUILDING ACROSS THE REGION WILL BRING
WARMER TEMPERATURES AND PLENTY OF SUNSHINE FRIDAY AND SATURDAY. A
WEAK FRONT WILL BRING MARINE CLOUDS AND AREAS OF DRIZZLE AND LIGHT
SHOWERS SATURDAY NIGHT AND SUNDAY MORNING. EXPECT TEMPERATURES TO
DROP MUCH CLOSER TO AVERAGE SUNDAY AND MONDAY. HIGH PRESSURE PUSHING
BACK OVER THE REGION NEXT WEEK WILL BRING ANOTHER ROUND OF
UNSEASONABLY WARM WEATHER.
&&
.SHORT TERM...SATELLITE PICTURES SHOWED A LARGE UPPER LOW OFF THE S
CA COAST...WITH THE NORTHWARD EXTENDING TROUGH AXIS RUNNING ROUGHLY
UP THE PACIFIC NW COAST. MODELS CONTINUE THE PREVIOUS TREND OF
INDICATING THE LOW MOVING SLOWLY E AND THEN NE THROUGH THE WEEKEND
ACROSS THE DESERT SW. WHILE SURFACE PRES GRADIENTS REMAINED ONSHORE
OVER THE FORECAST AREA EARLY FRI MORNING...THE LOW LEVEL FLOW ABOVE
THE SURFACE WAS OFFSHORE OUT OF THE NE. THIS HAS RESULTED IN DRYING
OVER THE AIR MASS AT LOW LEVELS...WITH LITTLE INDICATION IN SURFACE
OBSERVATIONS THROUGH THE EARLY MORNING HOURS OF ANY MARINE CLOUDS
REDEVELOPING. THE MOST LIKELY AREA IN THIS PATTERN FOR ANY LOW
CLOUDS OR FOG TO DEVELOP IN THE MORNING WOULD BE ALONG THE CENTRAL
OREGON COAST...SO WILL LEAVE A MENTION FOR CLOUDS AND FOG IN THIS
MORNING.
MODEL SOUNDINGS AGAIN HINTING AT SOME CONDITIONAL INSTABILITY OVER
THE CASCADES THIS AFTERNOON...ALTHOUGH MOST MODEL QPF FIELDS
GENERALLY INDICATE ANY THREAT OF PRECIPITATION WILL BE SUPPRESSED SE
OF THE FORECAST AREA. WITH THE INCREASINGLY EASTERLY MID AND UPPER
LEVEL FLOW TODAY WILL HANG ON TO A CHANCE FOR AFTERNOON AND EVENING
THUNDERSTORMS OVER THE S PART OF THE CASCADES. WILL CONTINUE WITH A
DRY AND MOSTLY SUNNY FORECAST INTO SAT AS THE UPPER LOW CONTINUES TO
MOVE E AND A SW TO NE ORIENTED UPPER RIDGE SINKS DOWN OVER THE
REGION SAT. SUBSIDENCE WILL RESULT IN WARMING TEMPS AGAIN FRI AND
SAT.
SAT NIGHT INTO SUN MODELS CONTINUE TO AGREE ON A EITHER A WEAK COLD
FRONT OR A STRONG NW MARINE PUSH...YOU DECIDE. EITHER WAY DEEP
MARINE MOISTURE MOVES IN SAT NIGHT AS THE UPPER FLOW TURNS NW BEHIND
A SHORTWAVE CUTTING ACROSS WA. WITH SOME DYNAMICS AND LOW LEVEL
MOISTURE WILL KEEP IN CHANCES FOR DRIZZLE MOVING IN SAT NIGHT...THEN
SOME DRIZZLE OR LIGHT SHOWERS MAINLY IN THE MORNING SUN. COOLER
TEMPS ALSO IN STORE...AND MORE IN LINE WITH CLIMATOLOGY WITH THE
MARINE AIR MASS.
&&
.LONG TERM...AN UPPER TROUGH OVER THE INTERIOR PACIFIC NW MON IS
EXPECTED TO KEEP THE COOLER AIR AND MARINE CLOUDS IN PLACE THROUGH
MON MORNING. GENERAL TREND WITH MODELS OVER THE NEXT SEVERAL DAYS
HAS HEIGHTS BUILDING OVER THE REGION AS AN OFFSHORE RIDGE NUDGES
EASTWARD. WITH A THERMALLY INDUCED TROUGH EXPECTED TO BUILD UP ALONG
THE OREGON COAST TUE THE RESULTING LOW LEVEL OFFSHORE FLOW WILL
BRINGING DRY AND MOSTLY SUNNY WEATHER WITH WARMING TEMPS THROUGH THE
WEEK. BY THU GFS AND EC AGREE ON H8 TEMPS REACHING 15 TO 16 DEG
C...WHICH SHOULD BE GOOD FOR HIGHS BACK INTO THE MID 80S IN THE
INLAND VALLEYS. WARMEST TEMPS ON THE COAST HOWEVER APPEAR LIKELY TO
COME ON WED...AS ONSHORE FLOW RETURNS LATER IN THE WEEK WITH THE
SURFACE TROUGH AXIS MOVING INLAND.
&&
.AVIATION...VFR ACROSS THE BOARD EARLY THIS MORNING. THERE MAY BE
SOME LOCALIZED LOW-END MVFR OR HIGH-END IFR CIGS ALONG THE CENTRAL
OREGON COAST THROUGH 16Z OR SO. THERE IS ALSO A CHANCE OF MVFR
CIGS BETWEEN KCVO AND KEUG 12Z TO 16Z. OTHERWISE...VFR CONDITIONS
TO PREVAIL THROUGH 06Z SAT. NORTH WIND GUSTS 20-30 KT ALONG THE
CENTRAL COAST FRI AFTERNOON THROUGH EARLY EVENING.
KPDX AND APPROACHES...VFR CONDITIONS THROUGH FRI EVENING. WEISHAAR
&&
.MARINE...HIGH PRES OVER THE WATERS FOR THE NEXT FEW DAYS. PRIMARY
MARINE ISSUE WILL BE SMALL CRAFT WIND ADVISORY TIMING. 00Z NAM AND
GFS SHOW WIND SPEEDS EASING JUST A BIT FRI MORNING...BUT
INCREASING AGAIN IN THE AFTERNOON. OUTER WATERS WILL REMAIN IN
SMALL CRAFT ADVISORY WIND CONDITIONS THROUGH AT LEAST SAT
EVENING...IF NOT A LITTLE LONGER. 00Z NAM SHOWS 30 KT BOUNDARY
LAYER SUSTAINED SPEEDS OVER PZZ275 FRI AFTERNOON THROUGH THE
EVENING...WITH 975MB SPEEDS PUSHING 40 KT. CONTEMPLATED GOING WITH
A GALE WARNING FOR PZZ275...BUT FOR NOW WILL MAINTAIN UPPER-END
SMALL CRAFT ADVISORY WIND SPEEDS.
INNER WATERS GET COMPLICATED. WENT WITH A NEW SMALL CRAFT WIND
ADVISORY FOR PZZ255 18Z THIS MORNING THROUGH 09Z SAT. EXPECT GUSTS
UP TO 30 KT. NORTHERN INNER WATERS...PZZ250...SHOULD SEE WIND
SPEEDS REACHING SMALL CRAFT ADVISORY LEVELS BY EARLY AFTERNOON...AND
ENDING A LITTLE SOONER THAN PZZ255.
COLD FRONT...OR MORE LIKE A STRONG MARINE SURGE...OCCURS
SUN...WHICH WILL TURN THE WIND MORE OUT OF THE NW. STRONGEST
SPEEDS EXPECTED TO SWITCH TO THE NRN OUTER WATERS SUN. WIND SPEEDS
FINALLY FALL BELOW 20 KT MON...AND SHIFT NORTH TO NORTHEAST MON
NIGHT AS A THERMALLY-INDUCED SURFACE LOW DEVELOPS ALONG THE
COASTLINE.
WIND-DRIVEN SEAS WILL CONTINUE THE CHOPPY CONDITIONS WITH SQUARE
SEAS AT TIMES. HIGHEST SEAS TODAY THROUGH SATURDAY WILL BE IN
PZZ275 WHERE WIND-WAVES UP TO 8 FT ARE LIKELY. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT SATURDAY FOR
WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR FROM 10 TO
60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM THIS AFTERNOON TO 11
PM PDT THIS EVENING FOR COASTAL WATERS FROM CAPE
SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SATURDAY
FOR WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO 60
NM.
SMALL CRAFT ADVISORY FOR WINDS FROM 11 AM THIS MORNING TO 2 AM
PDT SATURDAY FOR COASTAL WATERS FROM CASCADE HEAD TO
FLORENCE OR OUT 10 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 7 AM
PDT THIS MORNING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 4 PM
THIS AFTERNOON TO 7 PM PDT THIS EVENING.
&&
$$
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
National Weather Service Spokane WA
1055 PM PDT THU MAY 5 2016
.SYNOPSIS...
Most of the Inland NW will see dry and mild conditions Friday
through the weekend. However breezy to locally windy conditions
are expected at times...especially Sunday afternoon and evening as
a strong cold front passes through. Cooler and unsettled weather
is expected on Monday before a warming trend begins again for the
middle of next week.
&&
.DISCUSSION...
Update: Large closed low moving towards the southern California
coast tonight continues to pump moisture up from the south into
southeast Washington into the south Idaho Panhandle. Storms
earlier this evening over NE Oregon have moved into the Blue
Mountains, Camas Prairie, and Lewiston area as of 945 pm, with
another cell between St. Maries and Clarkia. Yet another batch of
storms is approaching Kamiah. The forecast for tonight has been
updated based on current radar and lightning trends. The NAM shows
most unstable CAPE values of 200-500 J/KG persisting into the
overnight hours in these areas and thus a chance of thunderstorms
was extended into the overnight hours. Elsewhere drier north-
northeast flow in the lower levels as well as more stability in
the mid levels should keep dry conditions persisting into the
overnight hours. JW
&&
.AVIATION...
06Z TAFS: Showers and isolated thunderstorms will continue tonight
over far SE Washington into the south Idaho Panhandle. This will
moisten the boundary layer and could led to areas of stratus by
sunrise near KPUW/KLWS. But for now kept prevailing conditions
MVFR due to only light rain amounts near KPUW/KLWS with the best
chance of stratus east of these TAF sites. Otherwise a tight
northerly pressure gradient develops tonight which will result in
increasing north- northeast winds especially at KMWH/KCOE by
Friday morning. Friday afternoon the best chance of thunderstorms
will be over the mountains near Lewiston as the increasing north-
northeast winds helps dry out the lower level air mass over much
of Central and Northeast Washington into the north Idaho
Panhandle. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 54 77 54 81 55 76 / 10 10 10 0 0 10
Coeur d`Alene 49 76 50 81 52 75 / 20 10 10 10 0 10
Pullman 49 75 49 78 51 72 / 50 10 10 10 0 10
Lewiston 53 81 54 83 56 78 / 50 20 10 10 10 10
Colville 45 81 47 85 48 80 / 10 10 10 0 0 10
Sandpoint 47 74 44 79 46 73 / 20 10 10 0 0 20
Kellogg 45 73 44 79 46 72 / 50 10 10 10 0 20
Moses Lake 52 83 53 86 52 80 / 10 10 0 0 0 0
Wenatchee 54 82 57 86 58 77 / 10 10 0 0 0 0
Omak 48 81 53 85 52 79 / 10 10 0 0 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
958 PM PDT THU MAY 5 2016
.SYNOPSIS...
Isolated showers and thunderstorms will be possible mainly across
southeast Washington into the Idaho Panhandle this evening. Some
storms will be capable of heavy rainfall...hail...and gusty winds.
Improving but breezy conditions will begin on Friday, lasting
through the weekend. More unsettled and cooler weather is expected
next week.
&&
.DISCUSSION...
Update: Large closed low moving towards the southern California
coast tonight continues to pump moisture up from the south into
southeast Washington into the south Idaho Panhandle. Storms
earlier this evening over NE Oregon have moved into the Blue
Mountains, Camas Prairie, and Lewiston area as of 945 pm, with
another cell between St. Maries and Clarkia. Yet another batch of
storms is approaching Kamiah. The forecast for tonight has been
updated based on current radar and lightning trends. The NAM shows
most unstable CAPE values of 200-500 J/KG persisting into the
overnight hours in these areas and thus a chance of thunderstorms
was extended into the overnight hours. Elsewhere drier north-
northeast flow in the lower levels as well as more stability in
the mid levels should keep dry conditions persisting into the
overnight hours. JW
&&
.AVIATION...
00Z TAFS: Main aviation concern is the potential for thunderstorms
mainly over southeast Washington and the south Idaho Panhandle
this evening which could impact the KLWS/KPUW TAF sites. Thus far
the storms are weakening as they come off the Blue Mountains and
the HRRR shows storms weakening this evening as they approach the
KLWS/KPUW TAF sites. Thus for now confidence is only low to
moderate of these sites being impacted and thus thunder was
removed for now. However will be monitoring radar trends.
Otherwise a tight northerly pressure gradient develops tonight
which will result in increasing north-northeast winds especially at
KMWH/KCOE by Friday morning. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 54 77 54 81 55 76 / 10 10 10 0 0 10
Coeur d`Alene 49 76 50 81 52 75 / 20 10 10 10 0 10
Pullman 49 75 49 78 51 72 / 20 10 10 10 0 10
Lewiston 53 81 54 83 56 78 / 50 20 10 10 10 10
Colville 45 81 47 85 48 80 / 10 10 10 0 0 10
Sandpoint 47 74 44 79 46 73 / 20 10 10 0 0 20
Kellogg 45 73 44 79 46 72 / 50 10 10 10 0 20
Moses Lake 52 83 53 86 52 80 / 10 10 0 0 0 0
Wenatchee 54 82 57 86 58 77 / 10 10 0 0 0 0
Omak 48 81 53 85 52 79 / 10 10 0 0 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
902 AM PDT FRI MAY 6 2016
.SYNOPSIS...A BROAD UPPER LEVEL LOW NOW CENTERED JUST OFF OF THE
SOUTHERN CALIFORNIA COAST WILL SHIFT SLOWLY EASTWARD AND INLAND
TODAY. BANDS OF MOISTURE ROTATING AROUND IT WILL MAINTAIN SHOWER
CHANCES OVER OUR DISTRICT THROUGH SATURDAY EVENING. THUNDERSTORMS
WILL CONTINUE TO BE POSSIBLE AS WELL...PRIMARILY MORE INLAND
AREAS. PRECIP CHANCES WILL DIMINISH SATURDAY NIGHT AND SUNDAY
MORNING...WITH DRY CONDITIONS THEN EXPECTED TO PREVAIL THROUGH THE
REMAINDER OF THE FORECAST PERIOD. A GRADUAL WARMING TREND IS
EXPECTED FOR THE FIRST HALF OF NEXT WEEK AS A RIDGE OF UPPER LEVEL
HIGH PRESSURE BUILDS OVER THE WEST COAST.
&&
.DISCUSSION...AS OF 9:00 AM PDT FRIDAY...SHOWERS EXPECTED TO
RETURN TO OUR REGION SHORTLY. IN FACT HRRR IS FAIRLY BULLISH AND
BRINGS AN AREA OF MOISTURE (WELL DEPICTED BY RADARS) TO MOST OF
THE SF BAY REGION DOWN TO SANTA CRUZ AND SANTA CLARA COUNTY BY
EARLY IN THE AFTERNOON. AFTER THAT SHOWERS CAN BE EXPECTED WITH
ANOTHER ROUND OF RAIN FORECAST FOR TOMORROW. DID A MINOR UPDATE
THIS MORNING TO THE FORECAST AND UPPED THE POPS FOR SATURDAY IN
LIGHT OF LATEST GUIDANCE. ALSO ADDED A SLIGHT CHANCED FOR
THUNDERSTORMS TO EASTERN PARTS OF THE CWA. RAINFALL AMOUNTS STILL
FORECAST TO BE FAIRLY LIGHT WITH UNDER 1/4" IN MOST URBAN SPOTS.
LOCAL RANGES COULD SEE UP TO 2/3".
WILL UPDATE FORECAST TODAY AS NECESSARY BASED ON THE TRACK OF THE
RAIN.
.PREVIOUS DISCUSSION...LATEST KMUX RADAR DATA
AND SURFACE OBS INDICATE DRY CONDITIONS NOW PREVAILING ACROSS
MOST OF OUR DISTRICT...THOUGH WITH SOME SHOWERS HAVING JUST DEVELOPED
OVER THE SOUTHERN SANTA LUCIA MTNS OF MONTEREY COUNTY. WATER
VAPOR SATELLITE IMAGERY AND MODEL ANALYSIS SHOW A BROAD AND
DIFFUSE UPPER LEVEL LOW NEAR THE SOUTHERN CALIFORNIA COAST...WITH
ITS CENTER PRESENTLY IN THE VICINITY OF THE NORTHERN CHANNEL
ISLANDS. THE SYNOPTIC SCALE WEATHER SITUATION FOR OUR AREA IS AN
UNUSUAL ONE...WITH THE FLOW ALOFT ADVECTING IN A MOIST AND
POTENTIALLY UNSTABLE AIR MASS FROM THE EAST. THE NEXT BAND OF CLOUDINESS
IS SPREADING RAPIDLY WESTWARD INTO THE SF BAY AREA THROUGH THE
MIDDLE OF THE CENTRAL VALLEY. THUS FAR HOWEVER...ASSOCIATED
PRECIP HAS LARGELY BEEN CONFINED TO THE HIGHER ELEVATIONS OF THE
SIERRA NEVADA WITH NEITHER KDAX NOR KMUX RADARS...OR SURFACE
OBS...INDICATING ANY APPRECIABLE ASSOCIATED SHOWER ACTIVITY
PRESENTLY MOVING TOWARDS US. AS A RESULT EXPECT THE DAY TO GET OFF
TO A DRY START...AT LEAST THROUGH THE MORNING COMMUTE.
THEREAFTER THOUGH CONFIDENCE DIMINISHES. MODEL PERFORMANCE IN
GENERAL WITH THIS SYSTEM THUS FAR...IN TERMS OF TIMING AND
LOCATION OF ASSOCIATED PRECIPITATION...HAS NOT BEEN PARTICULARLY
IMPRESSIVE. AND EVEN IN THE SHORT TERM...WIDE VARIATION BETWEEN
MODEL SOLUTIONS IN THIS RESPECT CONTINUES TO BE EVIDENT. THE NEW
06Z RUN OF THE GFS SHOWS PRECIP THIS AFTERNOON PRIMARILY CONFINED
TO SANTA CLARA AND SAN BENITO COUNTIES...WHILE THE 06Z NAM SPREADS
IT OVER ALMOST ALL OF OUR DISTRICT ASIDE FROM SONOMA COUNTY...THE
LATEST (09Z) HRRR RUN STARTS THE SHOWER ACTIVITY IN THE LATE
MORNING OVER THE NORTH BAY WITH IT THEN DIMINISHING AS IT MOVES
SOUTHWARD THROUGH THE CENTRAL SF BAY AREA DURING THE
AFTERNOON...AND THE LATEST AVAILABLE (00Z) OUTPUT FROM THE ECMWF
MODEL FOCUSES IT ON THE FAR SE PORTION OF OUR CWA DURING THE
AFTERNOON. AS A RESULT...VERY DIFFICULT TO NAIL DOWN DETAILS IN
GRIDS AND FORECAST.
THAT SAID HOWEVER...THERE IS MUCH BETTER AGREEMENT REGARDING THE
GENERAL LARGER-SCALE PICTURE AND EVOLUTION. GOOD CONSENSUS THAT
THE UPPER LEVEL LOW WILL TRACK GRADUALLY EASTWARD THROUGH FAR
SOUTHERN CALIFORNIA AND INTO ARIZONA BY SUNDAY MORNING. BY THAT
POINT ALL ASSOCIATED PRECIP SHOULD HAVE SHIFTED EASTWARD OF OUR
DISTRICT...BUT UNTIL THEN SHOWER CHANCES WILL CONTINUE.
THUNDERSTORMS WILL ALSO REMAIN POSSIBLE THROUGH THIS
EVENING...PRIMARILY OVER THE MOUNTAINS AND MORE INLAND AREAS...AND
THEN SHOULD DIMINISH AND COME TO AN END AS THE AIR MASS
STABILIZES.
FROM SUNDAY AFTERNOON THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...DRY CONDITIONS AND A WARMING TREND ARE EXPECTED TO PREVAIL
WITH GOOD LONGER RANGE MODEL AGREEMENT THAT AN UPPER LEVEL RIDGE
WILL BUILD IN OVER THE WEST COAST. BOTH THE ECMWF AND GFS
SIGNIFICANTLY RAISE 850 MB TEMPS AS THIS OCCURS...UP INTO THE 15C
TO 17C RANGE BY WEDNESDAY AND THURSDAY WITH AFTERNOON HIGHS...AT
LEAST INLAND AREAS...THEN PROJECTED TO REACH UP INTO THE 80S.
&&
.AVIATION...AS OF 4:49 AM PDT FRIDAY...FOR 12Z TAFS. CHALLENGING
FORECAST DETAILS GIVEN SYNOPTIC PATTERN. EXPECT IFR TO MVFR CIGS
FROM NOW THROUGH ABOUT 16Z. THEN RAIN SHIELD CURRENTLY OVER THE
SIERRA SHOULD ROTATE OVER BAY AREA FROM LATE MORNING THROUGH THE
AFTERNOON WITH PERIODS OF RAIN AND MVFR CIGS. WINDS TO REMAIN
MAINLY WNW AND LIGHT. PRECIP ACTIVITY TO SLOWLY ROTATE OVER
MONTEREY BAY TERMINALS THROUGH EARLY EVENING. MOIST BOUNDARY LAYER
LIKELY TO LEAVE LOW CIGS IN PLACE AGAIN TONIGHT...THEN A REPEAT
PERFORMANCE SATURDAY MORNING AS ANOTHER BAND OF LIGHT RAIN
ROTATING OFF THE SIERRA WILL LIKELY IMPACT BAY AREA TERMINALS.
THIS WAS REFLECTED IN 30 HOUR TAFS FOR KSFO/KOAK IN SHOWING -RA
RETURNING SATURDAY MORNING AROUND 14Z.
VICINITY OF KSFO...LOW CONFIDENCE ON DETAILS IN TERMS OF
FLUCTUATING CLOUD HEIGHTS. DO EXPECT WINDS TO REMAIN FAVORABLE
FROM THE NW. -RA BAND CURRENTLY OVER THE SIERRA TO REACH KSFO
AROUND 16-17Z THROUGH MOST OF THE AFTERNOON WITH MVFR CIGS. -RA
TO END BY LATE AFTERNOON WITH VCSH TURNING TO PERSISTENT MVFR
CLOUDS AGAIN TONIGHT.
SFO BRIDGE APPROACH...SIMILAR TO KSFO. EXPECT FLUCTUATING CLOUD
HEIGHTS THIS MORNING. COULD BE PERIOD OF VISUALS THROUGH 16-17Z
BUT THEN AS PRECIP BAND ARRIVES BY MID TO LATE MORNING EXPECT THAT
WINDOW TO CLOSE THROUGH THE AFTERNOON HOURS WITH PERIODS OF -RA
AND MVFR CIGS.
MONTEREY BAY TERMINALS...LOW CIGS THIS MORNING FROM 400 FEET AT
KMRY TO 1600 FEET AT KSNS. VCSH WITH CHANGING CLOUD DECKS IN
PLACE THIS MORNING. -RA TO ARRIVE THIS AFTERNOON AS PRECIP SHIELD
ROTATES FROM NORTHEAST TO SOUTHWEST THROUGH THE DAY.
&&
.MARINE...AS OF 9:00 AM PDT FRIDAY...A LOW PRESSURE STORM SYSTEM
WILL SHIFT FARTHER INLAND TODAY BUT CONTINUE TO SPREAD RAIN
SHOWERS OVER THE COASTAL WATERS. WINDS WILL BE SPLIT... WITH
BREEZY NORTHERLY WINDS ACROSS THE NORTHERN OUTER WATERS AND LIGHT
SOUTHERLY WINDS ALONG MUCH OF THE COAST AND THE SOUTHERN WATERS.
SEAS WILL CONTINUE TO BE LIGHT THROUGH SATURDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
&&
$$
PUBLIC FORECAST: BELL/BLIER
AVIATION: R_WALBRUN
MARINE: MWW
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
449 AM PDT FRI MAY 6 2016
.SYNOPSIS...A BROAD UPPER LEVEL LOW NOW CENTERED JUST OFF OF THE
SOUTHERN CALIFORNIA COAST WILL SHIFT SLOWLY EASTWARD AND INLAND
TODAY. BANDS OF MOISTURE ROTATING AROUND IT WILL MAINTAIN SHOWER
CHANCES OVER OUR DISTRICT THROUGH SATURDAY EVENING. THUNDERSTORMS
WILL CONTINUE TO BE POSSIBLE THROUGH THIS EVENING...PRIMARILY MORE
INLAND AREAS. PRECIP CHANCES WILL DIMINISH SATURDAY NIGHT AND
SUNDAY MORNING...WITH DRY CONDITIONS THEN EXPECTED TO PREVAIL
THROUGH THE REMAINDER OF THE FORECAST PERIOD. A GRADUAL WARMING
TREND IS EXPECTED FOR THE FIRST HALF OF NEXT WEEK AS A RIDGE OF
UPPER LEVEL HIGH PRESSURE BUILDS OVER THE WEST COAST.
&&
.DISCUSSION...AS OF 4:20 AM PDT FRIDAY...LATEST KMUX RADAR DATA
AND SURFACE OBS INDICATE DRY CONDITIONS NOW PREVAILING ACROSS
MOST OF OUR DISTRICT...THOUGH WITH SOME SHOWERS HAVING JUST DEVELOPED
OVER THE SOUTHERN SANTA LUCIA MTNS OF MONTEREY COUNTY. WATER
VAPOR SATELLITE IMAGERY AND MODEL ANALYSIS SHOW A BROAD AND
DIFFUSE UPPER LEVEL LOW NEAR THE SOUTHERN CALIFORNIA COAST...WITH
ITS CENTER PRESENTLY IN THE VICINITY OF THE NORTHERN CHANNEL
ISLANDS. THE SYNOPTIC SCALE WEATHER SITUATION FOR OUR AREA IS AN
UNUSUAL ONE...WITH THE FLOW ALOFT ADVECTING IN A MOIST AND
POTENTIALLY UNSTABLE AIR MASS FROM THE EAST. THE NEXT BAND OF CLOUDINESS
IS SPREADING RAPIDLY WESTWARD INTO THE SF BAY AREA THROUGH THE
MIDDLE OF THE CENTRAL VALLEY. THUS FAR HOWEVER...ASSOCIATED
PRECIP HAS LARGELY BEEN CONFINED TO THE HIGHER ELEVATIONS OF THE
SIERRA NEVADA WITH NEITHER KDAX NOR KMUX RADARS...OR SURFACE
OBS...INDICATING ANY APPRECIABLE ASSOCIATED SHOWER ACTIVITY
PRESENTLY MOVING TOWARDS US. AS A RESULT EXPECT THE DAY TO GET OFF
TO A DRY START...AT LEAST THROUGH THE MORNING COMMUTE.
THEREAFTER THOUGH CONFIDENCE DIMINISHES. MODEL PERFORMANCE IN
GENERAL WITH THIS SYSTEM THUS FAR...IN TERMS OF TIMING AND
LOCATION OF ASSOCIATED PRECIPITATION...HAS NOT BEEN PARTICULARLY
IMPRESSIVE. AND EVEN IN THE SHORT TERM...WIDE VARIATION BETWEEN
MODEL SOLUTIONS IN THIS RESPECT CONTINUES TO BE EVIDENT. THE NEW
06Z RUN OF THE GFS SHOWS PRECIP THIS AFTERNOON PRIMARILY CONFINED
TO SANTA CLARA AND SAN BENITO COUNTIES...WHILE THE 06Z NAM SPREADS
IT OVER ALMOST ALL OF OUR DISTRICT ASIDE FROM SONOMA COUNTY...THE
LATEST (09Z) HRRR RUN STARTS THE SHOWER ACTIVITY IN THE LATE
MORNING OVER THE NORTH BAY WITH IT THEN DIMINISHING AS IT MOVES
SOUTHWARD THROUGH THE CENTRAL SF BAY AREA DURING THE
AFTERNOON...AND THE LATEST AVAILABLE (00Z) OUTPUT FROM THE ECMWF
MODEL FOCUSES IT ON THE FAR SE PORTION OF OUR CWA DURING THE
AFTERNOON. AS A RESULT...VERY DIFFICULT TO NAIL DOWN DETAILS IN
GRIDS AND FORECAST.
THAT SAID HOWEVER...THERE IS MUCH BETTER AGREEMENT REGARDING THE
GENERAL LARGER-SCALE PICTURE AND EVOLUTION. GOOD CONSENSUS THAT
THE UPPER LEVEL LOW WILL TRACK GRADUALLY EASTWARD THROUGH FAR
SOUTHERN CALIFORNIA AND INTO ARIZONA BY SUNDAY MORNING. BY THAT
POINT ALL ASSOCIATED PRECIP SHOULD HAVE SHIFTED EASTWARD OF OUR
DISTRICT...BUT UNTIL THEN SHOWER CHANCES WILL CONTINUE.
THUNDERSTORMS WILL ALSO REMAIN POSSIBLE THROUGH THIS
EVENING...PRIMARILY OVER THE MOUNTAINS AND MORE INLAND AREAS...AND
THEN SHOULD DIMINISH AND COME TO AN END AS THE AIR MASS
STABILIZES.
FROM SUNDAY AFTERNOON THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...DRY CONDITIONS AND A WARMING TREND ARE EXPECTED TO PREVAIL
WITH GOOD LONGER RANGE MODEL AGREEMENT THAT AN UPPER LEVEL RIDGE
WILL BUILD IN OVER THE WEST COAST. BOTH THE ECMWF AND GFS
SIGNIFICANTLY RAISE 850 MB TEMPS AS THIS OCCURS...UP INTO THE 15C
TO 17C RANGE BY WEDNESDAY AND THURSDAY WITH AFTERNOON HIGHS...AT
LEAST INLAND AREAS...THEN PROJECTED TO REACH UP INTO THE 80S.
&&
.AVIATION...AS OF 4:49 AM PDT FRIDAY...FOR 12Z TAFS. CHALLENGING
FORECAST DETAILS GIVEN SYNOPTIC PATTERN. EXPECT IFR TO MVFR CIGS
FROM NOW THROUGH ABOUT 16Z. THEN RAIN SHIELD CURRENTLY OVER THE
SIERRA SHOULD ROTATE OVER BAY AREA FROM LATE MORNING THROUGH THE
AFTERNOON WITH PERIODS OF RAIN AND MVFR CIGS. WINDS TO REMAIN
MAINLY WNW AND LIGHT. PRECIP ACTIVITY TO SLOWLY ROTATE OVER
MONTEREY BAY TERMINALS THROUGH EARLY EVENING. MOIST BOUNDARY LAYER
LIKELY TO LEAVE LOW CIGS IN PLACE AGAIN TONIGHT...THEN A REPEAT
PERFORMANCE SATURDAY MORNING AS ANOTHER BAND OF LIGHT RAIN
ROTATING OFF THE SIERRA WILL LIKELY IMPACT BAY AREA TERMINALS.
THIS WAS REFLECTED IN 30 HOUR TAFS FOR KSFO/KOAK IN SHOWING -RA
RETURNING SATURDAY MORNING AROUND 14Z.
VICINITY OF KSFO...LOW CONFIDENCE ON DETAILS IN TERMS OF
FLUCTUATING CLOUD HEIGHTS. DO EXPECT WINDS TO REMAIN FAVORABLE
FROM THE NW. -RA BAND CURRENTLY OVER THE SIERRA TO REACH KSFO
AROUND 16-17Z THROUGH MOST OF THE AFTERNOON WITH MVFR CIGS. -RA
TO END BY LATE AFTERNOON WITH VCSH TURNING TO PERSISTENT MVFR
CLOUDS AGAIN TONIGHT.
SFO BRIDGE APPROACH...SIMILAR TO KSFO. EXPECT FLUCTUATING CLOUD
HEIGHTS THIS MORNING. COULD BE PERIOD OF VISUALS THROUGH 16-17Z
BUT THEN AS PRECIP BAND ARRIVES BY MID TO LATE MORNING EXPECT THAT
WINDOW TO CLOSE THROUGH THE AFTERNOON HOURS WITH PERIODS OF -RA
AND MVFR CIGS.
MONTEREY BAY TERMINALS...LOW CIGS THIS MORNING FROM 400 FEET AT
KMRY TO 1600 FEET AT KSNS. VCSH WITH CHANGING CLOUD DECKS IN
PLACE THIS MORNING. -RA TO ARRIVE THIS AFTERNOON AS PRECIP SHIELD
ROTATES FROM NORTHEAST TO SOUTHWEST THROUGH THE DAY.
&&
.MARINE...AS OF 4:49 AM PDT FRIDAY...AN UPPER LOW OVER SOUTHERN
CALIFORNIA WILL RESULT IN FAIRLY LIGHT PRESSURE GRADIENTS ACROSS
THE REGION...EXCEPT OVER THE NORTHERN OUTER WATERS WHERE STRONGER
NW WINDS PERSIST AND SMALL CRAFT ADVISORIES ARE IN EFFECT. THE LOW
WILL KEEP THE THREAT OF SHOWERS IN THE FORECAST TODAY INTO
SATURDAY. SEAS WILL BE LIGHT WITH PERIODS AROUND 10 SECONDS
THROUGH SATURDAY. A LONG PERIOD SW SWELL WILL ENTER THE WATERS BY
SUNDAY. HIGH PRESSURE RETURNS BY EARLY NEXT WEEK WITH A THERMAL
TROUGH KEEPING THE STRONGEST WINDS OVER THE NORTHERN OUTER WATERS
WHILE GENERALLY LIGHT WIND AND SEAS ARE FORECAST NEAR SHORE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
&&
$$
PUBLIC FORECAST: BLIER
AVIATION: R_WALBRUN
MARINE: R_WALBRUN
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
437 AM PDT FRI MAY 6 2016
.SYNOPSIS...A BROAD UPPER LEVEL LOW NOW CENTERED JUST OFF OF THE
SOUTHERN CALIFORNIA COAST WILL SHIFT SLOWLY EASTWARD AND INLAND
TODAY. BANDS OF MOISTURE ROTATING AROUND IT WILL MAINTAIN SHOWER
CHANCES OVER OUR DISTRICT THROUGH SATURDAY EVENING. THUNDERSTORMS
WILL CONTINUE TO BE POSSIBLE THROUGH THIS EVENING...PRIMARILY MORE
INLAND AREAS. PRECIP CHANCES WILL DIMINISH SATURDAY NIGHT AND
SUNDAY MORNING...WITH DRY CONDITIONS THEN EXPECTED TO PREVAIL
THROUGH THE REMAINDER OF THE FORECAST PERIOD. A GRADUAL WARMING
TREND IS EXPECTED FOR THE FIRST HALF OF NEXT WEEK AS A RIDGE OF
UPPER LEVEL HIGH PRESSURE BUILDS OVER THE WEST COAST.
&&
.DISCUSSION...AS OF 4:20 AM PDT FRIDAY...LATEST KMUX RADAR DATA
AND SURFACE OBS INDICATE DRY CONDITIONS NOW PREVAILING ACROSS
MOST OF OUR DISTRICT...THOUGH WITH SOME SHOWERS HAVING JUST DEVELOPED
OVER THE SOUTHERN SANTA LUCIA MTNS OF MONTEREY COUNTY. WATER
VAPOR SATELLITE IMAGERY AND MODEL ANALYSES SHOW A BROAD AND
DIFFUSE UPPER LEVEL LOW NEAR THE SOUTHERN CALIFORNIA COAST...WITH
ITS CENTER PRESENTLY IN THE VICINITY OF THE NORTHERN CHANNEL
ISLANDS. THE SYNOPTIC SCALE WEATHER SITUATION FOR OUR AREA IS AN
UNUSUAL ONE...WITH THE FLOW ALOFT ADVECTING IN A MOIST AND
POTENTIALLY UNSTABLE AIR MASS FROM THE EAST. THE NEXT BAND OF CLOUDINESS
IS SPREADING RAPIDLY WESTWARD INTO THE SF BAY AREA THROUGH THE
MIDDLE OF THE CENTRAL VALLEY. THUS FAR HOWEVER...ASSOCIATED
PRECIP HAS LARGELY BEEN CONFINED TO THE HIGHER ELEVATIONS OF THE
SIERRA NEVADA WITH NEITHER KDAX NOR KMUX RADARS...OR SURFACE
OBS...INDICATING ANY APPRECIABLE ASSOCIATED SHOWER ACTIVITY
PRESENTLY MOVING TOWARDS US. AS A RESULT EXPECT THE DAY TO GET OFF
TO A DRY START...AT LEAST THROUGH THE MORNING COMMUTE.
THEREAFTER THOUGH CONFIDENCE DIMINISHES. MODEL PERFORMANCE IN
GENERAL WITH THIS SYSTEM THUS FAR...IN TERMS OF TIMING AND
LOCATION OF ASSOCIATED PRECIPITATION...HAS NOT BEEN PARTICULARLY
IMPRESSIVE. AND EVEN IN THE SHORT TERM...WIDE VARIATION BETWEEN
MODEL SOLUTIONS IN THIS RESPECT CONTINUES TO BE EVIDENT. THE NEW
06Z RUN OF THE GFS SHOWS PRECIP THIS AFTERNOON PRIMARILY CONFINED
TO SANTA CLARA AND SAN BENITO COUNTIES...WHILE THE 06Z NAM SPREADS
IT OVER ALMOST ALL OF OUR DISTRICT ASIDE FROM SONOMA COUNTY...THE
LATEST (09Z) HRRR RUN STARTS THE SHOWER ACTIVITY IN THE LATE
MORNING OVER THE NORTH BAY WITH IT THEN DIMINISHING AS IT MOVES
SOUTHWARD THROUGH THE CENTRAL SF BAY AREA DURING THE
AFTERNOON...AND THE LATEST AVAILABLE (00Z) OUTPUT FROM THE ECMWF
MODEL FOCUSES IT ON THE FAR SE PORTION OF OUR CWA DURING THE
AFTERNOON. AS A RESULT...VERY DIFFICULT TO NAIL DOWN DETAILS IN
GRIDS AND FORECAST.
THAT SAID HOWEVER...THERE IS MUCH BETTER AGREEMENT REGARDING THE
GENERAL LARGER-SCALE PICTURE AND EVOLUTION. GOOD CONSENSUS THAT
THE UPPER LEVEL LOW WILL TRACK GRADUALLY EASTWARD THROUGH FAR
SOUTHERN CALIFORNIA AND INTO ARIZONA BY SUNDAY MORNING. BY THAT
POINT ALL ASSOCIATED PRECIP SHOULD HAVE SHIFTED EASTWARD OF OUR
DISTRICT...BUT UNTIL THEN SHOWER CHANCES WILL CONTINUE.
THUNDERSTORMS WILL ALSO REMAIN POSSIBLE THROUGH THIS
EVENING...PRIMARILY OVER THE MOUNTAINS AND MORE INLAND AREAS...AND
THEN SHOULD DIMINISH AND COME TO AN END AS THE AIR MASS
STABILIZES.
FROM SUNDAY AFTERNOON THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...DRY CONDITIONS AND A WARMING TREND ARE EXPECTED TO PREVAIL
WITH GOOD LONGER RANGE MODEL AGREEMENT THAT AN UPPER LEVEL RIDGE
WILL BUILD IN OVER THE WEST COAST. BOTH THE ECMWF AND GFS
SIGNIFICANTLY RAISE 850 MB TEMPS AS THIS OCCURS...UP INTO THE 15C
TO 17C RANGE BY WEDNESDAY AND THURSDAY WITH AFTERNOON HIGHS...AT
LEAST INLAND AREAS...THEN PROJECTED TO REACH UP INTO THE 80S.
&&
.AVIATION...AS OF 10:30 PM PDT THURSDAY...UPPER LEVEL LOW WEST OF
THE CENTRAL COAST MOVING TOWARDS SOUTHERN CALIFORNIA. ISOLATED
SHOWERS ARE CONFINED TO THE HILLS THIS EVENING WHILE PATCHY LOW
CLOUDS ARE ALONG THE COAST. MVFR EXPECTED TO SPREAD OVER THE MRY
BAY AREA THIS EVENING AND INTO THE SFO BAY AREA LATER TONIGHT.
AN UPPER LEVEL DISTURBANCE ROTATING AROUND THE LOW WILL BRING A
CHANCE OF SHOWERS TO THE AREA FRIDAY MORNING. THESE SHOWERS WILL
BE COMING FROM THE NORTHEAST. MVFR CIGS EXPECTED MOST OF THE DAY
FRIDAY. CANNOT RULE OUT AN ISOLATED THUNDERSTORM FRIDAY AFTERNOON.
VICINITY OF KSFO...MVFR CIGS AFTER 12Z CONTINUING THROUGH THE REST
OF THE DAY. SCATTERED SHOWERS AFTER 16Z. MAINLY LIGHT SOUTHWEST
WINDS.
SFO BRIDGE APPROACH...SIMILAR AS KSFO.
MONTEREY BAY TERMINALS...MVFR CIGS AFTER 08Z. A FEW SHOWERS
POSSIBLE AFTER 17Z.
&&
.MARINE...AS OF 10:30 PM PDT THURSDAY...AN UPPER LOW OVER SOUTHERN
CALIFORNIA WILL RESULT IN FAIRLY LIGHT PRESSURE GRADIENTS ACROSS
THE REGION...EXCEPT OVER THE NORTHERN OUTER WATERS WHERE STRONGER
NW WINDS PERSIST AND SMALL CRAFT ADVISORIES ARE IN EFFECT. THE LOW
WILL KEEP THE THREAT OF SHOWERS IN THE FORECAST TODAY INTO
SATURDAY. SEAS WILL BE LIGHT WITH PERIODS AROUND 10 SECONDS
THROUGH SATURDAY. A LONG PERIOD SW SWELL WILL ENTER THE WATERS BY
SUNDAY. HIGH PRESSURE RETURNS BY EARLY NEXT WEEK WITH A THERMAL
TROUGH KEEPING THE STRONGEST WINDS OVER THE NORTHERN OUTER WATERS
WHILE GENERALLY LIGHT WIND AND SEAS ARE FORECAST NEAR SHORE.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
&&
$$
PUBLIC FORECAST: BLIER
AVIATION: W PI
MARINE: R_WALBRUN
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AREA FORECAST DISCUSSION
NWS EUREKA CA
427 AM PDT FRI MAY 6 2016
.SYNOPSIS...AN UPPER LEVEL LOW WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND POSSIBLY SATURDAY AFTERNOON. THEN
BUILDING HIGH PRESSURE WILL BRING DRY WEATHER BACK TO THE REGION
WITH A WARMING TREND FOR EARLY NEXT WEEK.
&&
.DISCUSSION...A CLOSED UPPER LOW ACROSS THE SOUTHWESTERN UNITED
STATES WILL DOMINATE THE WEATHER PATTERN BRINGING UNSEASONABLY COOL
TEMPERATURES AND AFTERNOON THUNDERSTORMS THROUGH SATURDAY. SHOWERS
AND THUNDERSTORMS SHOULD ORIGINATE OVER INTERIOR MOUNTAINS AND
TRAVEL WESTWARD THROUGH THE DAY POSSIBLY IMPACTING COASTAL AREAS.
THE STRONGEST INSTABILITY WILL BE ACROSS THE INTERIOR LATE THIS
AFTERNOON WITH CONVECTIVE PARAMETERS WEAKENING BY SATURDAY AFTERNOON
AS THE UPPER LOW BEGINS TO SHIFT EAST. THE HRRR INDICATES THERE WILL
BE AN INITIAL BAND OF SHOWER ACTIVITY THIS MORNING ACROSS MENDOCINO
COUNTY WITH AFTERNOON CONVECTION SPINNING UP WITH THE HEAT OF THE
DAY ACROSS THE HIGHER TERRAIN OF TRINITY AND INTERIOR MENDOCINO
COUNTIES. EXPECT STRONGER SHOWERS/STORMS TO WEAKEN AS THEY
APPROACH THE COAST LATE THIS AFTERNOON BUT A RUMBLE OF THUNDER
WILL CERTAINLY BE POSSIBLE NEAR THE COAST.
A RIDGE OF HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING UPPER LOW
AND BRING AN END TO SHOWER ACTIVITY AND A WARMING TREND TO NORTHERN
CALIFORNIA. SOME ISOLATED SHOWERS WILL BE POSSIBLE ACROSS
INTERIOR MOUNTAINS SUNDAY AFTERNOON WITH THE WARMING/DRYING TREND
UNFOLDING THROUGH EARLY NEXT WEEK. TEMPERATURES WILL SURPASS
NORMAL VALUES FOR THIS TIME OF YEAR PARTICULARLY ACROSS INTERIOR
LOCATIONS. HOWEVER, EASTERLY FLOW SHOULD DEVELOP EARLY NEXT WEEK
AS THE THERMAL TROUGH SHIFTS WESTWARD AND BRINGS WARMER, DRY AIR
TO COASTAL REGIONS. DESPITE MOSTLY SUNNY CONDITIONS FOR MUCH OF
NORTHERN CALIFORNIA EARLY NEXT WEEK, THE SURFACE FLOW PATTERN
SUGGESTS THAT STRATUS WILL MAKE A RETURN TO PARTS THE COAST.
LITTLE CHANGES WERE OTHERWISE MADE TO THE EXTENDED FORECAST. KML
&&
.AVIATION...LOW CEILINGS WITH REDUCED VISIBILITIES IN FOG WILL
CONTINUE INTO THE MORNING HOURS ALONG THE REDWOOD COAST. ALTHO KCEC
IS PRESENTLY SOCKED IN WITH 1SM VISIBILITY IN FOG... HIGH RESOLUTION
MODELS ARE PROGGING INCREASING OFFSHORE...AND THUS DOWNSLOPE...FLOW
AT KCEC. THIS SHOULD BE ENUF TO ERODE LOW CLOUDS AND FOG LATER THIS
MORNING...WHILE LOW CLOUDS MAY LINGER INTO THE AFTERNOON OR LONGER
AT KACV. LOW CLOUDS HAVE BROKEN UP AT KUKI. MID CLOUDS SHOULD LIMIT
ADDITIONAL RADIATIVE COOLING...AND LIMITED SURROUNDING OBS DON`T
INDICATE PRESENCE OF LOW CLOUDS. UNCERTAINTY IS HIGH...BUT WILL
PROBABLY REMOVE LOW CEILING WITH NEXT TAF PACKAGE. WINDS WILL BECOME
GUSTY AT KCEC DURING THE AFTERNOON. /SEC
&&
.MARINE...THE TIGHT GRADIENT BETWEEN STRONG OFFSHORE HIGH PRESSURE
AND INLAND LOW PRESSURE WILL MAINTAIN STRONG WINDS FOR THE NEXT FEW
DAYS...ESPECIALLY OFFSHORE. HAVE EXTENDED ALL HEADLINES ANOTHER 6
HOURS OR SO. THE N OFFSHORE GALE WARNING CONTINUES THRU LATE
TONIGHT...THE S OFFSHORE SMALL CRAFT ADVISORY AND HAZARDOUS SEAS
WARNING CONTINUE THRU SAT MORNING...AND THE N NEAR SHORE SMALL CRAFT
ADVISORY CONTINUES THRU SAT AFTERNOON. GRADIENT WINDS WILL WEAKEN
SLIGHTLY OVER THE WEEKEND...BUT ADVISORY LEVEL WINDS WILL CONTINUE
OVER THE N OFFSHORE WATERS. WINDS WILL MORE UNIFORMLY DIMINISH BY
NEXT TUE. SHORT PERIOD...STEEP WAVES WILL DOMINATE INTO EARLY NEXT
WEEK. /SEC
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 3 PM PDT SATURDAY FOR PZZ450.
GALE WARNING UNTIL 3 AM PDT SATURDAY FOR PZZ470.
SMALL CRAFT ADVISORY UNTIL 9 AM PDT SATURDAY FOR PZZ475.
HAZARDOUS SEAS WARNING UNTIL 9 AM PDT SATURDAY FOR PZZ475.
&&
$$
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AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
402 AM PDT FRI MAY 6 2016
.SYNOPSIS...
A slow-moving low pressure system will bring a chance of showers
and a slight chance of thunderstorms to the region through the
weekend. High pressure will rebuild next week bringing mostly
clear skies with a warming trend to the area Monday through the
middle of next week. Night through morning low clouds and patchy
fog are likely for some coastal areas and coastal valley
locations through much of next week.
&&
.SHORT TERM...(TDY-SUN)
An unseasonably cold upper low was centered just west of Point
Conception this morning. This upper low is expected to move
slightly to the southeast and remain over Southern California
through Saturday before moving east. There will continue be some
upper level disturbances rotating around and within the upper low
over the forecast area today. 500 mb Temps will be quite cold for
this time of year at around -22 degrees C. This will be the main
factor to cause the atmosphere to become quite unstable with high
lapse rates...especially over the mountains this afternoon and
evening. Confidence is high that there will be scattered
thunderstorms developing over the mountains this afternoon and
evening. Latest model soundings near Lockwood Valley in the
Ventura Mtns indicated high CAPE values over 1,100 j/kg, Lifted
Index around -6 and plenty of low- mid level moisture to work
with. Unlike yesterday, the upper flow will be much weaker due to
the proximity of the upper low. Therefore a FLASH FLOOD WATCH has
been issued for the Los Angeles, Ventura, Santa Barbara County
Mountains, as well as the Antelope Valley and Cuyama Valley valid
from noon today through 8 pm this evening. The Precipitable Waters
are around .85 inches which is also high for this time of year.
People in the flash flood watch areas should keep an eye on the
weather today.
Once again, it will be difficult to pin-point when and where coast
and valley showers will occur today. There will be a slight chance
for thunderstorms across the SBA,VTU,LA Valleys and coastal areas
as thunderstorms will likely drift to the SE off the mountains.
There will be enough instability continuing into this evening to
continue the slight chance of thunderstorms. The upper low will
continue to swing some moisture over the forecast through
Saturday. Showers will be less widespread and not as
convective...however there will continue to be slight instability
over the mountains on Saturday so a few isolated thunderstorms
can`t be ruled out. Winds will remain fairly week out of the
north, so there could be a few late afternoon showers drifting
into the valleys and coastal areas of LA,VTA and SBA counties.
By Sunday...the upper low will be well into the Central Plains,
but there will continue to be some lingering moisture across the
region, so expect at the least partly cloudy skies. Went ahead and
pulled out POPS for Sunday as latest models showed no rain and a
much more stable atmosphere. There will likely be a flat cumulus
clouds across the mountains and foothills...but cloud cover should
not be as widespread across coast and valleys.
As far as high temps go...due to the clouds and unsettled weather
conditions, temps will be much cooler than normal across the area
today thru Sun, with highs ranging from 7 to 16 deg below normal
today. High temps will continue to be below normal for this time
of year, but trend towards normal by next Tuesday. Hi temps for
the cst and vlys will be generally in the 60s today, then warm
slightly into the mid 60s to low 70s for Sat, and upper 60s to
lower 70s for Sun.
.LONG TERM...(MON-THU)
EC/GFS continue to be in good agreement Mon thru Thu.
Upper level ridging will build off the California coast Monday
and become amplified by Tue. This ridge will then shift over
California Wednesday and Thursday. Expect dry and warmer
conditions through the extended period. Some night and morning
marine layer low clouds and fog should affect some coastal and
coastal valley areas at times, otherwise clear to partly cloudy
skies can be expected across the region for Mon thru Thu. High
temps will be around normal by next Tue and Wed, and then warmer
than normal for many areas by Thursday, with the warmest vlys
reaching the mid 80s.
&&
.AVIATION...06/0010Z.
At 0005z at KLAX... there was no marine inversion.
Overall... Low to moderate confidence in the 00z tafs. The
reduced confidence is primarily due to the hit and miss nature of
the showers and thunderstorms in the forecast. Conditions near any
thunderstorms will include variable and gusty winds... brief heavy
rain... and possible hail. Highest probability of showers and
tstms for KLAX, KLGB, KBUR, and KVNY is later this evening through
Friday morning.
KLAX and KBUR...Low to moderate confidence in the 00z taf. The
reduced confidence is primarily due to the hit and miss nature of
the showers and thunderstorms in the forecast. Highest probability
of showers and thunderstorms for KLAX and KBUR will be 06z-18z,
where there is a 60 percent chance of showers and a 20 percent
chance of thunderstorms.
&&
.MARINE...06/300 AM.
There is a chance of showers across the coastal waters through
Saturday night and a slight chance of thunderstorms today, mainly
south and east of the Channel Islands. Any storms that develop
will be capable of brief heavy downpours, gusty winds, small hail,
and dangerous cloud to ground lightning. Winds and seas should
remain below advisory criteria through Sunday, except in the
vicinity of any thunderstorms that develop.
The storm system moves out the of region by late Sunday and no
significant wind or sea conditions are expected through the early
half of next week.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Flash Flood Watch in effect from noon PDT today through this
evening For zones 38-52>54-59. (See LAXFFALOX).
PZ...NONE.
&&
$$
PUBLIC...CK
AVIATION...Hall
MARINE...Hall
SYNOPSIS...CK
weather.gov/losangeles
Area Forecast Discussion
National Weather Service Sacramento CA
402 AM PDT FRI MAY 6 2016
.Synopsis...
Unsettled weather will continue into the weekend. Drier and
warmer weather is then expected next week.
.Short Term Discussion
Closed low continues to impact our weather today as the center of
the low sits over SoCal today. Models continue to show a vort max
rotating around this low into our region this morning. Current
radar shows evidence of this as showers from Nevada are now
cyclonically moving across the Sierra into our CWA. The HRRR shows
a decent slug of moisture stretching from Yosemite up towards
Lassen Park and moving westward this morning across interior
NorCal between now through late morning with scattered showers
continuing for the rest of the day. Models indicating that the
atmosphere won`t be as unstable as yesterday, but there is still a
slight chance of thunderstorms. Lightning has already been
observed this morning over in Nevada. Residents should still be
prepared for periods of downpours, gusty winds, lightning, and
small hail today even though it may not be as widespread as
yesterday.
On Saturday, the low tracks farther east in the Great Basin, but
wrap around moisture will continue to stream into our CWA
continuing the threat of showers and possible thunderstorms into
Sunday. By Sunday, though, coverage will diminish with best
chances of shower activity persisting over the western Sierra
slopes.
Monday will start a drier, warmer trend for the work week as high
pressure ridging builds over the Eastern Pacific Ocean and impacts
the West Coast. Valley highs will return to the low 80s with
higher terrain in the 60s and 70s. JBB
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)
Forecast models are advertising a quick moving upper level
disturbance that should slide out of the Pacific Northwest that
may clip portions of northern California on Tuesday. This
disturbance may bring some isolated sprinkles in the mountains,
but no significant precipitation is expected Tuesday or Tuesday
night.
The main story in the long term forecast period is a return to quiet
weather with a pattern of warm and dry weather pushing into
California. An upper level ridge of high pressure will move eastward
from the Pacific Tuesday night through Wednesday that will bring
above normal high temperatures to the valley through the end of
next week.
&&
.AVIATION...
A stagnant low pressure system positioned over California will
bring overcast conditions, light rain showers, and chances for
thunderstorms today across the valley. As a result, there will be
periods of MVFR ceilings for the terminals north and south of
Sacramento.
Antecedent moisture from rainfall yesterday could cause some
reduced visibilities and ceilings between MVFR and IFR for
periods this morning for terminals in Sacramento county.
Ceilings and visibilities should improve across the valley Friday
evening with a return to VFR conditions for the terminals.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
330 AM PDT FRI MAY 6 2016
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL ALLOW FOR THE CONTINUATION OF UNSETTLED
WEATHER THROUGH THE WEEKEND. THIS SYSTEM WILL BRING THE THREAT OF
SHOWERS AND THUNDERSTORMS TO MUCH OF THE REGION ALONG WITH COOLER
TEMPERATURES.
&&
.DISCUSSION...
SHOWERS CONTINUE THIS MORNING ACROSS THE CENTRAL CALIFORNIA
INTERIOR AS A RESULT OF THE UPPER LOW SLOWING MOVING ONSHORE
TOWARD SOUTHERN CALIFORNIA. WHILE REGIONAL DOPPLER RADARS SHOW A
DECREASE IN ACTIVITY THIS MORNING...THE HRRR MESO-SCALE MODEL
SHOWS A CONTINUATION OF SHOWERS THROUGH SUNRISE THIS MORNING AS
THE FLOW TURNS MORE NORTHERLY. WITH THE SLOW ADVANCEMENT OF THE
UPPER LOW ACROSS SOUTHERN CALIFORNIA...THE DISTRICT WILL REMAIN IN
A NORTHERLY FLOW PATTERN TODAY WITH ADDITIONAL COLD AIR ADVECTED
FROM THE NORTH. CONVECTIVELY SPEAKING...FRIDAY WILL SEE MORE
THUNDERSTORMS DURING THE AFTERNOON AS A CONTINUATION OF SOUTHERLY
MOISTURE SURGES INTO CENTRAL CALIFORNIA.
A CHANGE IN THE WEATHER WILL BE OBSERVED ON SATURDAY AS THE THREAT
OF CONVECTION DIMINISHES. WHILE SHOWERS WILL STILL BE OBSERVED
DURING THE DAY...THE THREAT OF THUNDERSTORMS WILL BE SMALL. IN
ADDITION...THE UPPER LOW WILL BE CLOSER TO THE FOUR CORNERS AREA
AS THE DISTRICT WILL THEN BE IN AN OFFSHORE FLOW PATTERN.
TYPICALLY...THE FLOW PATTERN IS DRY WITH PRECIP CONFINED TO THE
HIGH COUNTRY OF THE SIERRA NEVADA. SUNDAY WILL SEE A CONTINUATION
OF THE CHANGE IN THE WEATHER PATTERN AS WE TRANSITION TO A DRY
REGIME. CURRENT FORECAST ON TRACK WITH THIS THINKING AS A RIDGE
OF HIGH PRESSURE SHIFTS TOWARD THE WEST COAST.
WHILE THE TRANSITION TO A RIDGE PATTERN WILL BE SLOW AS ANOTHER
WEATHER DISTURBANCE DROPS THROUGH THE PAC-NORTHWEST/INTER-MTN
REGION EARLY NEXT WEEK. YET...THE RIDGE PATTERN WILL TAKE HOLD OF
THE REGION BY TUESDAY AS TEMPERATURES REACH WELL INTO THE 80S
ACROSS THE SAN JOAQUIN VALLEY. ONCE THE RIDGE PATTERN PUSHES INTO
THE REGION BY THE MIDDLE OF NEXT WEEK...IT MAY REMAIN OVER THE
WEST COAST FOR SEVERAL DAYS. CURRENTLY...WHILE MODELS ARE SHOWING
LESS CONFIDENCE IN THE LOWER RANGE PERIODS...THEY DO INDICATE THE
DEVELOPMENT OF ANOTHER CLOSED CUT-OFF LOW EXISTING OVER THE
EASTERN PACIFIC TOWARD THE END OF NEXT WEEK. AT THE MOMENT...
CONFIDENCE IN THE INTRODUCTION OF PRECIP TOWARD THE END OF THE
FORECAST PERIOD IS VERY LOW. DUE TO THE NATURE OF THE CUT-OFF LOW
...WILL OPT FOR THE RIDGE SOLUTION IN THE LONG TERM AND WAIT FOR
BETTER MODEL CONSENSUS ON HOW TO DEAL WITH THE NEXT DISTURBANCE.
&&
.AVIATION...AREAS OF MVFR AND LOCAL MOUNTAIN OBSCURING IFR OVER THE
SOUTHERN SIERRA NEVADA AND TEHACHAPI MOUNTAINS THRU 12Z SATURDAY.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLE THROUGHOUT THE
CENTRAL CA INTERIOR THROUGH 12Z SATURDAY. OTHERWISE...VFR CONDITIONS
WILL PREVAIL DURING THE NEXT 24 HOURS.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP FOR ADDITIONAL INFORMATION
AN/OR TO PROVIDE FEEDBACK.
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...MOLINA
AVN/FW...JDB
SYNOPSIS...MOLINA
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
441 AM MDT FRI MAY 6 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM MDT FRI MAY 6 2016
THE DEEPENING TROUGH/CLOSED LOW TRACKING SLOWLY E-SEWRD ACROSS
SOUTHERN CALIF IS BEGINNING TO EXERT ITS DOMINANCE ON FLOW AT ALL
LEVELS AND WX AS FAR EAST AS THE SRN AND CNTRL ROCKIES. DEEP S-SWLY
FLOW ON THE FRONT SIDE OF THIS TROUGH CONTINUES TO DIRECT MID AND
HIGH-LEVEL MOISTURE UP INTO THE AREA AND LATER TODAY A SPOKE OF MID-
LEVEL ENERGY AND SHEAR WHICH THE RAP AND OTHER MODELS INDICATE
PASSING OVER NRN NEW MEXICO AT THIS TIME. EVEN WITH VARYING AMOUNTS
OF HIGH CLOUDINESS THIS MORNING STRONG DIABATIC HEATING SHOULD
MANAGE TO GENERATE 8-9C/KM BNDRY LAYER LAPSE RATES AND SFC BASED 600-
1200 J/KG CAPES ON THE PLAINS BY MIDDAY. WHILE THE WELL MIXED
BOUNDARY LAYER APPEAR LACKING OF MOISTURE...MODELS INDICATE A
GRADUAL INCREASE IN MID-LEVEL MOISTURE WITH INCREASING SELY MID-
LEVEL FLOW IN ADVANCE OF THE SHORTWAVE DISTURBANCE SWINGING UP FROM
SERN COLORADO. WHILE CONVECTIVE CLOUDS WILL BE ON THE INCREASE THIS
AFTERNOON...MODELS DO NOT INDICATE MUCH IN THE WAY OF QPF ON THE
PLAINS TODAY. INVERTED-V MODEL SOUNDINGS INDICATE A FAVORABLE SUB-
CLOUD ENVIRONMENT FOR MICROBURST FORMATION THIS AFTERNOON EVEN AS
MEAN LAYER PW VALUES CREEP UPWARD PRIOR TO PASSAGE OF THE U/A
DISTURBANCE TIMED TO OCCUR AROUND 00Z IN THE DENVER AREA. AFTER
00Z/SAT...THE MICROBURST THREAT SHOULD QUICKLY DIMINISH FROM SOUTH
TO NORTH WITH INFLUX OF DRIER MIX-LEVEL AIR BEHIND THE SHORTWAVE.
THIS DRYING IS FORECAST TO CONTINUE EVEN NEAR THE GROUND OVERNIGHT AS
MODELS SHOW A WELL PRONOUNCED DRY SLOT ROTATING UP FROM NEW MEXICO.
FOR THE HIGH COUNTRY...ODDS LOOK BETTER FOR MEASURABLE PRECIP
TODAY...BEGINNING AS EARLY AS LATE THIS MORNING. GREATER MOISTURE...
BETTER SYNOPTIC SCALE LIFT..INSTABILITY AND OROGRAPHICS SHOULD
PROVE ADEQUATE FOR SHOWER AND T-STORM FORMATION. SHOWERS AND
T-STORM MOTIONS WILL PRIMARILY SOUTH-TO-NORTH TODAY. SO THERE`S LITTLE
CHANCE THAT THE PLAINS WILL SEE MUCH IF ANY OF THIS HIGH COUNTRY
CONVECTION. GUSTY WINDS AND SHORT PERIODS OF LIGHT TO MODERATE
RAINFALL POSSIBLE THIS AFTERNOON THRU EARLY EVENING FROM THE
FRONT RANGE WESTWARD. I PUT THE CHANCE OF MEASURABLE PRECIP IN THE
HIGH COUNTRY AT 30-50 PCT...WITH AS FEW POCKETS OF 60 PCT OVER
THE HIGHER PEAKS AND RIDGES ROUGHLY NORTH OF I-70 LATE. LIKE THE
PLAINS...THE CHANCE OF PRECIP IN THE HIGH COUNTRY SHOULD STEADILY
DECREASE WITH CLOUD COVER OVERNIGHT WITH AN INFLUX OF DRIER AIR
FROM THE SOUTH AHEAD OF THE UPPER TROUGH.
TEMPERATURES TODAY WILL BE QUITE WARM AGAIN BUT NOT QUITE RECORD
TERRITORY. RECORD HIGH AT DENVER IS 86. SHOULD SEE LOW 80S IN THE
METRO AREA AND LOW TO MID 80S ACROSS THE PLAINS. HIGH COUNTRY WILL
ALSO BE UNSEASONABLY WARM TODAY WITH HIGHS IN THE UPPER 50S AND
60S. TONIGHT...TEMPERATURE WILL REMAIN QUITE MILD WITH MID 40S/
LOWER 50S ON THE PLAINS AND MOSTLY 30S IN THE HIGH COUNTRY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 430 AM MDT FRI MAY 6 2016
LARGE UPPER LEVEL LOW WILL BE OVER THE GREAT BASIN SATURDAY. A
STRONG WAVE EMBEDDED IN THE SOUTHWEST FLOW ALOFT WILL MOVE ACROSS
EASTERN COLORADO SATURDAY AND EVENTUALLY BECOME THE NEW CENTER OF
THE UPPER LEVEL LOW SOMEWHERE OVER WYOMING OR NORTHEAST COLORADO.
FOR SATURDAY...A SURFACE LOW WILL BE OVER NORTHEAST COLORADO WITH
A BOUNDARY DRAPED ACROSS THE AREA. EASTERLY WINDS NORTH OF IT WILL
PUMP MOISTURE INTO THE AREA. SURFACE BASED CAPES WILL BE UP TO
2000 J/KG. THIS COMBINED WITH GOOD SHEAR IS EXPECTED TO PRODUCE
SEVERE THUNDERSTORMS WITH LARGE HAIL...STRONG WINDS AND POSSIBLY A
FEW TORNADOS. STILL SOME UNCERTAINTY WHERE THIS BOUNDARY WILL SET
UP. LATEST MODEL RUNS ARE LITTLE MORE NORTH AND HAS MOST OF THE
CONVECTION NORTH OF A LINE FROM FORT COLLING TO AKRON. STILL
WOULDN`T BE SURPRISED IF THIS BOUNDARY ENDS UP FARTHER SOUTH THAN
THE MODELS ARE FORECASTING.
ON SUNDAY...THE ECMWF HAS THE CENTER OF THE UPPER LEVEL LOW OVER
NORTHEAST COLORADO WHILE THE GFS SHOWS IT OVER WYOMING. NO STRONG
FEELING WHICH ONE IS RIGHT. IT WILL BE COOL AND IF THE LOW FORMS
OVER COLORADO...EXPECT MORE PRECIPITATION ACROSS THE AREA.
NORTHWEST FLOW WILL PREVAIL MONDAY AS THE UPPER LEVEL LOW WEAKENS
EAST OF COLORADO. STILL SHOULD BE ENOUGH MOISTURE AND INSTABILITY
TO TRIGGER SCATTERED/ISOLATED SHOWERS AND STORMS. ANOTHER UPPER
LEVEL LOW WILL MOVE INTO THE NORTHERN ROCKIES MONDAY. THIS LOW IS
EXPECTED TO DIG SOUTH INTO WYOMING TUESDAY. ISOLATED TO SCATTERED
CONVECTION WILL AGAIN BE POSSIBLE. THIS LOW IS EXPECTED TO MOVE
EAST OF THE AREA WEDNESDAY AND THURSDAY. COULD SEE A FEW SHOWERS
AND STORMS WEDNESDAY...BUT DRIER AND WARMER CONDITIONS SHOULD
PREVAIL THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 430 AM MDT FRI MAY 6 2016
VFR CONDITIONS ON TAP NEXT 24 HOURS FOR THE DENVER AREA. ONLY
CONCERN WILL BE THE HIGH BASED MOSTLY DRY T-STORMS THAT ARE
EXPECTED TO TRACK NORTH-NORTHWEST ACROSS THE METRO AREA BETWEEN
2 PM MDT-7PM MDT TODAY. ASIDE FROM A STRAY LIGHTNING STRIKE...
THESE ISOLATED TO WIDELY SCATTERED CELLS MAY ALSO PRODUCE
MICROBURST WINDS TO 40KTS. THREAT OF THESE WINDS SHOULD END ERLY
THIS EVENING WITH DRIER AIR FEEDING UP FROM THE SOUTH. WINDS TODAY
GENERALLY SOUTH-SOUTHEASTERLY AT 7-15KTS..WITH STRONGER GUSTY AND
ERRATIC WINDS UNDER AND NEAR PASSING SHOWERS. OVERNIGHT...WINDS IN
THE DENVER AREA TO BECOME A BIT STRONGER FROM THE SOUTHEAST AT
10-20KTS...WITH HIGHER GUSTS POSSIBLE IN THE EVENING AT KAPA AND
KDEN.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM...MEIER
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
436 AM MDT FRI MAY 6 2016
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 436 AM MDT FRI MAY 6 2016
LARGE CLOSED LOW MOVING ONSHORE THE WESTERN US TODAY WILL SLOWLY
MOVE EASTWARD OVER THE NEXT FEW DAYS. TODAY...STRONG LARGE SCALE
ASCENT WILL BE DRIVING THUNDERSTORM DEVELOPMENT FROM SOUTH TO
NORTH. ALREADY THIS MORNING THE CLOUD TOPS HAVE BEEN INCREASING
FAIRLY DRAMATICALLY FROM NORTHERN ARIZONA INTO UTAH. THIS AREA OF
ENHANCING PRECIPITATION WILL SHIFT EAST TODAY AND BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO EASTERN UTAH AND WESTERN COLORADO FOR
MUCH OF TODAY. SOME STORMS MAY NEAR OR POTENTIALLY EXCEED SEVERE
THUNDERSTORM CRITERIA TODAY...WITH WIND BEING THE LARGEST THREAT.
WIND GUSTS MAY EXCEED 58 MPH IN THE STRONGEST STORMS AND HAIL UP
TO ONE INCH IS POSSIBLE...THOUGH LESS LIKELY THAN REACHING THE
STRONG WIND GUSTS. THE RAP FORECAST MODEL INDICATES DAYTIME
HEATING WILL OVERCOME CONVECTIVE INHIBITION ACROSS NE UTAH AROUND
NOON AND ACROSS WESTERN COLORADO SHORTLY THEREAFTER. FORECAST CAPE
VALUES EXCEED 1000 J/KG THIS AFTERNOON...INDICATING A PEAK OF
CONVECTIVE ACTIVITY AROUND 4 TO 8PM ACROSS NE UTAH AND NW COLORADO.
THERE WILL BE A LOT OF VIRGA AROUND TODAY WHICH WILL HELP TO KEEP
CONDITIONS BREEZY THROUGHOUT THE DAY WITH OR WITHOUT RAIN NEARBY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 436 AM MDT FRI MAY 6 2016
THE DETAILS OF THIS SLOW MOVING SYSTEM CONTINUE TO EVOLVE. IT
LOOKS LIKE THERE WILL BE AT LEAST A COUPLE OF ROBUST CIRCULATIONS
THAT WILL TRACK ACROSS THE AREA SAT AND SUN. THROUGH THE
WEEKEND...LOOK FOR ENHANCED SHOWERS AND THUNDERSTORMS AS EACH
CIRCULATION PASSES. POPS GENERALLY SHOW A BROAD-BRUSHED FORECAST
WITH CHANCE TO LIKELY POPS...MAINLY IN THE MOUNTAINS.
AFTERNOONS/EARLY EVENINGS WILL SHOW AN UPTICK IN CONVECTION
INCLUDING THUNDERSTORMS DUE TO THE DIURNAL ASSIST. SNOW LEVELS
WILL REMAIN HIGH AS THIS SYSTEM IS QUITE MILD. ACCUMULATING SNOW
WILL GENERALLY BE AT OR ABOVE 10K-11K FEET. BUT CONVECTION WILL
CERTAINLY DRIVE SNOW...GRAUPEL OR SNOW PELLETS LOWER AT TIMES.
DID BUMP UP POPS OVER THE NEXT FEW DAYS DURING TIME PERIODS WHERE
I WAS MORE CONFIDENT IN PRECIPITATION OCCURRING...WITH THE BIGGEST
INCREASE LATE SUNDAY NIGHT. AVAILABLE MOISTURE SIGNIFICANTLY
INCREASES LATE SUNDAY AND MONDAY AND THE CLOSED LOW WRAPS STRONG
ENERGY COUNTERCLOCKWISE INTO THE WESTERN SLOPE OF COLORADO.
EXACT SET-UP LOCATION OF THIS WRAP-AROUND WILL HAVE TO BE
DIAGNOSED IN LATER FORECASTS...BUT CONFIDENCE IS THERE FOR AN
UPTICK IN PRECIPITATION COVERAGE SUNDAY NIGHT INTO EARLY MONDAY.
WITH LESS CONFIDENCE...MODELS INDICATE ANOTHER SEPARATE
DISTURBANCE WILL BRUSH THE NORTH DURING THE TUE- WED TIME FRAME AS
A TROUGH PASSES ACROSS THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS. THE IMPACTS FROM THIS NEXT SYSTEM LOOK PRETTY LOW AT THIS
TIME.
A COOLING TREND WILL CONTINUE THROUGH SUNDAY. THE TREND WILL THEN
REVERSE FOR A SLOW WARMUP THROUGH THE NEW WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 436 AM MDT FRI MAY 6 2016
THE MORNING IS ALREADY STARTING OFF EXCITING WITH STORMS HAVING
INITIATED BEFORE 10Z. INITIATION OF STORMS WILL CONTINUE AS LARGE
SCALE ASCENT DRAMATICALLY INCREASES TODAY. GUSTY WINDS TO 60 MPH
WILL BE THE LARGEST THREAT TODAY WITH THUNDERSTORMS...BUT THIS IS
NOT EXPECTED UNTIL AFTER 18Z AND WILL BE VERY ISOLATED IN NATURE
IF AT ALL. CONDITIONS WILL STAY GENERALLY BREEZY TODAY. HEAVY
PRECIPITATION IS NOT EXPECTED AT THIS TIME...SO CIGS AND VIS WILL
REMAIN VFR THROUGH MOST OF THE DAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JAM
LONG TERM...EH/JAM
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1134 AM EDT FRI MAY 6 2016
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE INTO OUR AREA FROM THE SOUTHEAST
LATER TODAY, THEN LINGER THROUGH SATURDAY BEFORE DISSIPATING. A COLD
FRONT WILL MOVE THROUGH SUNDAY MORNING, FOLLOWING BY HIGH PRESSURE
SUNDAY NIGHT INTO MONDAY BEFORE MOVING OFFSHORE. A WARM FRONT LIFTS
NORTH ACROSS OUR AREA DURING TUESDAY, THEN STALLS IN OUR AREA
WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME HEAVIER SHOWERS HAVE BEEN TRAVERSING THE REGION THIS MORNING
WITH SCATTERED SHOWERS CONTINUING ACROSS THE AREA. EXPECT THE
HEAVIER RAIN TO CONTINUE TO PUSH TO THE WEST-SOUTHWEST AND OUT OF
THE AREA THIS MORNING. LIGHT TO MODERATE RAIN SHOWERS WILL
CONTINUE THROUGH THE REST OF THE DAY WITH SOME TAPERING OFF
EXPECTED FROM EAST TO WEST LATER IN THE DAY.
SPC HAS EXPANDED THE AREA OF GENERAL THUNDER SO HAVE INCLUDED A
SLIGHT RISK THROUGH THIS AFTERNOON ACROSS THE ENTIRE AREA. CONSIDERABLE
INSTABILITY ALOFT SUGGEST POTENTIAL FOR ISOLATED THUNDER/ASSOCIATED
SMALL HAIL WITH VERY STEEP MID LVL LAPSE RATES AND LOW WBZ NEAR
6000 FT. NOT SURE WHAT WILL TRIGGER THE THUNDER EXCEPT SFC
CONVERGENCE WITH THE LOW COMING ASHORE AND PERHAPS SOME AFTERNOON
SFC HEATING NEAR THE APPROACHING LOW OVER DE. TEMPS MAY BE SEVERAL
DEGREES COLDER THAN YDY I95 NWWD.
A GUSTY NE WIND FOR A TIME THIS MORNING NEAR 20 MPH EXCEPT GUSTS
MIDDAY AND EARLY AFTERNOON MONMOUTH AND OCEAN COUNTIES MAY APPROACH
35 MPH (SEE HRRR GUSTS AS A BAND OF STRONGER WIND WELL NORTH OF
THE LOW CENTER SHIFTS WESTWARD WITH LOW ALONG THE S SHORE OF LI).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HAVE UNCERTAINTY REGARDING TIMING OF ANY SHOWERS AND ANY LEFTOVER
ISOLATED EVENING TSTMS (SE PA/S NJ). CONFIDENCE ON WHAT OCCURS
AND WHERE, IS BELOW AVERAGE. IN PART THIS IS DUE TO RECENT LOSS
OF CONFIDENCE IN GFS QPF FCSTS. NE WIND DIMINISHING THIS EVENING
AND BECOMING LIGHT SOUTHERLY ON THE DELMARVA, POSSIBLY EVEN TO
I95.
FOG MAY BECOME A PROBLEM TONIGHT WITH A LIGHT WIND IN THE MIDST
OF VERTICALLY STACKED MOIST LOW PRESSURE SYSTEM.
FCST WAS A 50 50 BLEND OF THE 00Z/6 GFS/NAM MOS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN INITIAL CLOSED LOW CENTERED
OVER OUR AREA SATURDAY, HOWEVER THIS FEATURE OPENS UP DURING
SATURDAY AS IT SHIFTS EASTWARD. THIS OCCURS AS A STRONG SHORT WAVE
TROUGH DIVES SOUTHEASTWARD ACROSS THE GREAT LAKES SATURDAY AND INTO
THE NORTHEAST SATURDAY NIGHT AND SUNDAY. THE NEW TROUGH AMPLIFIES
ACROSS THE NORTHEAST SUNDAY BEFORE GRADUALLY LIFTING OUT MONDAY. A
WEAK RIDGE THEN ARRIVES FOR EARLY NEXT WEEK WITH A SURFACE WARM
FRONT ALSO MOVING THROUGH. THE WARM FRONT HOWEVER MAY END UP
STALLING IN OUR VICINITY WEDNESDAY AND THURSDAY AS ENERGY SHEARS
EASTWARD ALONG IT. GIVEN THE PATTERN CHANGE, MUCH WARMER AIR IS
EXPECTED TO ARRIVE NEXT WEEK WITH THIS CHANGE STARTING OVER THE
WEEKEND ESPECIALLY DURING SUNDAY. THE EXTENT OF THE WARMING THOUGH
NEXT WEEK WILL DEPEND ON THE PLACEMENT OF THE FRONTAL BOUNDARY AS IT
MAY MEANDER ACROSS OUR CWA AND ALSO PRECIPITATION CHCS. WE USED A
MODEL BLEND APPROACH FOR SATURDAY THROUGH SUNDAY NIGHT, THEN BLENDED
IN THE 00Z WPC GUIDANCE THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR SATURDAY AND SUNDAY...THIS TIME FRAME BEGINS WITH A CLOSED LOW
RIGHT OVER OUR AREA SATURDAY MORNING, HOWEVER THIS FEATURE WILL OPEN
UP AND SHIFT EASTWARD DURING THE COURSE OF THE DAY. THIS WILL BE DUE
TO A KICKER SHORT WAVE TROUGH AMPLIFYING ACROSS THE GREAT LAKES
REGION. A CORE OF -20C TO -24C AIR AT 500 MB IS OVER OUR AREA
SATURDAY MORNING, HOWEVER THIS MODIFIES THROUGH THE DAY AS THE
TROUGH OPENS UP AND SHIFTS TO OUR EAST. THE PRESENCE OF COLD AIR
ALOFT COMBINED WITH SOME LIFT FROM THE CLOSED LOW SHOULD RESULT IN
MAINLY SCATTERED SHOWERS SATURDAY ESPECIALLY INLAND. THE FLOW IS
LIGHT UNDER THE CLOSED LOW THEREFORE SHOWERS SHOULD BE SLOW MOVERS.
SINCE THE AIRMASS IS WARMING DURING THE COURSE OF THE DAY, THIS MAY
MITIGATE THE INSTABILITY POTENTIAL. IT APPEARS ANY INSTABILITY IS
MARGINAL AND THEREFORE THUNDER WAS NOT ADDED FOR SATURDAY ATTM. AS
WE LOSE THE CONTINUOUS ONSHORE FLOW COMPONENT AND THE TROUGH ALOFT
WEAKENING THROUGH SATURDAY, THERE SHOULD BE AT LEAST SOME BREAKS OF
SUNSHINE.
AN AMPLIFYING TROUGH FROM THE GREAT LAKES THEN STARTS TO NEAR OUR
AREA TOWARD DAYBREAK SUNDAY. LOW PRESSURE TRACKING TO OUR NORTH WILL
PULL A COLD FRONT INTO OUR AREA LATE SATURDAY NIGHT AND THIS FRONT
MAY MOVE IN A BIT FASTER. THERE APPEARS TO BE A PLUME OF DEEPER
MOISTURE IN COMBINATION WITH FORCING FOR ASCENT TO DRIVE SOME SHOWERS
/PERHAPS A BAND OF SHOWERS/ ACROSS MUCH OF OUR AREA. THE STRONGEST
FORCING MAY GLANCE OUR NORTHERN AREAS AND THEREFORE THE HIGHEST POPS
WERE PLACED THERE LATER AT NIGHT. ANY SHOWERS SHOULD QUICKLY SHIFT
OFFSHORE SUNDAY MORNING AS THE COLD FRONT ALSO EXITS, THEN DRIER AIR
AND BETTER MIXING WILL PROMOTE SUNSHINE FINALLY RETURNING FOR THE
AFTERNOON. IT WILL BE A BIT BREEZY THOUGH SUNDAY IN THE WAKE OF THE
COLD FRONT AS LOW-LEVEL LAPSE RATES STEEPEN AND THE PRESSURE
GRADIENT TIGHTENS. WE WENT A BIT WARMER THAN MOS FOR SUNDAY
ESPECIALLY FOR THE COASTAL PLAIN GIVEN DOWNSLOPING FLOW. HIGH
PRESSURE THEN STARTS TO ARRIVE SUNDAY NIGHT ALLOWING THE WINDS TO
DIMINISH.
FOR MONDAY AND TUESDAY...SOME WEAK RIDGING ARRIVES DURING MONDAY,
ALLOWING SURFACE HIGH PRESSURE TO BE OVER OUR CWA TO START BUT IT
LOOKS TO SHIFT OFFSHORE LATER MONDAY. THIS WILL ALLOW A SOUTHERLY
FLOW TO BECOME BETTER ESTABLISHED AND WITH DOWNSTREAM WAA
INCREASING, A WARMER TIME FRAME IS EXPECTED. THE WAA WILL BE USHERED
IN VIA A WARM FRONT AS IT CROSSES THE AREA DURING TUESDAY, AND THERE
COULD BE ENOUGH LIFT TO PRODUCE SOME SHOWERS OR A THUNDERSTORM
MAINLY TUESDAY AFTERNOON AND NIGHT. THE FORECAST CHALLENGE IS THAT
THIS FRONT MAY THEN STALL IN OUR AREA AS ENERGY INITIALLY SHEARS
EASTWARD ALONG IT. THIS SHEARING ENERGY COULD PRODUCE SOME
CONVECTION.
FOR WEDNESDAY AND THURSDAY...THE FORECAST CHALLENGE IS WITH THE
FRONTAL ZONE AS IT LOOKS TO BE DRAPED ACROSS OUR AREA, HOWEVER A
TROUGH AMPLIFYING ACROSS NEW ENGLAND WEDNESDAY MAY PUSH THE FRONT
FARTHER SOUTHWARD. THIS SOUTHWARD PUSH COULD BE ENHANCED AS HIGH
PRESSURE MAY BUILD DOWN SOME FROM NORTHERN NEW ENGLAND. A TROUGH IN
THE MIDWEST HOWEVER PUSHES SURFACE LOW PRESSURE UP THE OHIO VALLEY
WEDNESDAY NIGHT INTO THURSDAY, WITH DOWNSTREAM WAA AND SOUTHERLY
FLOW ALLOWING THE BOUNDARY TO START LIFTING NORTHWARD SOME AS A WARM
FRONT. THIS TIME FRAME SHOULD BE ON THE WARMER SIDE, HOWEVER THIS
WILL ULTIMATELY DEPEND ON THE POSITIONING OF THE FRONTAL BOUNDARY
AND ANY CONVECTION THAT OCCURS. GIVEN THE UNCERTAINTY, WE BLENDED
THE 00Z WPC GUIDANCE IN WITH CONTINUITY AND THEN MADE SOME TWEAKS.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...CIGS GENERALLY VARIABLE 600-1600 FT VSBY 1-4 MI IN SHOWERY
RAINS DURING THE MORNING WITH POSSIBLE IMPROVING CONDITIONS
DURING THE AFTERNOON. ISOLATED TSTM POSSIBLE DURING THE MORNING
KACY/KMIV AND THEN DURING THE AFTN ELSEWHERE. TSTMS NOT IN TAF DUE
TO LOW CONFIDENCE AND ISOLATED NATURE. NE WIND...GUSTS 15-23 KT FOR
A TIME LATER THIS MORNING-MIDDAY.
TONIGHT... MVFR/IFR CONDS IN ST/FOG, POSSIBLE CLUSTERS OF SHOWERS.
DIMINISHING NE WIND THIS EVENING NEAR AND N OF I78. OTHERWISE LIGHT
WIND TRENDING SOUTH.
OUTLOOK...
SATURDAY...MVFR/IFR CEILINGS IN THE MORNING SHOULD IMPROVE TO VFR IN
THE AFTERNOON. MAINLY SCATTERED SHOWERS ARE ANTICIPATED WHICH CAN
LOCALLY REDUCE THE VISIBILITY FOR A TIME, THEN A BAND OF SHOWERS
ARRIVES LATE AT NIGHT WITH A COLD FRONT. SOUTHEASTERLY WINDS MAINLY
LESS THAN 10 KNOTS, BECOMING SOUTHWEST AT NIGHT.
SUNDAY...BRIEF MVFR CONDITIONS IN THE MORNING WITH SOME SHOWERS AS A
COLD FRONT MOVES THROUGH, OTHERWISE VFR. WEST TO NORTHWEST WINDS
INCREASE TO 12-18 KNOTS WITH GUSTS TO 25 KNOTS, THEN DIMINISH AT
NIGHT.
MONDAY AND TUESDAY...VFR, THEN POSSIBLY SOME MVFR DURING TUESDAY
WITH A CHANCE OF SHOWERS AS A WARM FRONT MOVES THROUGH. WESTERLY
WINDS AROUND 10 KNOTS MONDAY, BECOMING LIGHT AT NIGHT THEN SHIFTING
TO SOUTHERLY TUESDAY.
&&
.MARINE...
WE HAVE UPGRADED THE SMALL CRAFT ADVISORY ON OUR NORTHERN TWO
OCEAN ZONES TO A GALE WARNING THROUGH THIS AFTERNOON. GALE FORCE
GUSTS ARE EXPECTED TO OCCUR OVER THE NEXT SEVERAL HOURS AND THEN
SHOULD TAPER OFF AS WE HEAD INTO THE LATE AFTERNOON AND EVENING.
SCA CONTINUES OCEAN WATERS THROUGH TONIGHT, ESPECIALLY DUE TO
SEAS.
FOG MAY BECOME A MARINE HAZARD LATER THIS FRIDAY NIGHT.
OUTLOOK...
SATURDAY...THE WINDS ARE ANTICIPATED TO BE LIGHT AS A CLOSED LOW
INITIALLY OVERHEAD WEAKENS AND THEN SHIFTS EASTWARD. THE SEAS MAY BE
RIGHT AT 5 FEET TO START ESPECIALLY ACROSS THE NORTHERN WATERS BUT
OVERALL THE CONDITIONS SHOULD BE TRENDING BELOW ADVISORY CRITERIA.
THEREFORE WE DID NOT EXTEND THE ADVISORY ATTM.
SUNDAY...WEST TO NORTHWEST WINDS TURN GUSTY TO AROUND 20 KNOTS WITH
SEAS AT OR BELOW 4 FEET. IT IS POSSIBLE WINDS GUST TO 25 KNOTS
NEARSHORE, HOWEVER OVERALL CONDITIONS ARE ANTICIPATED TO BE BELOW
ADVISORY CRITERIA.
MONDAY AND TUESDAY...SUB-ADVISORY CONDITIONS ARE ANTICIPATED DESPITE
SOME INCREASE IN A SOUTHERLY WIND MONDAY AND THEN AGAIN LATER
TUESDAY.
&&
.TIDES/COASTAL FLOODING...
PLEASE SEE THE HAZARD CFW STATEMENT FOR THE PARTICULARS RELATING
TO EACH AREA.
PHL: TIDAL DE ADVY EXPIRED BUT MAY NEED A NEW ONE TO BE ISSUED
THIS AFTERNOON FOR THE EARLY SATURDAY MORNING HIGH TIDE CYCLE.
CONFIDENCE IN EXCEEDING THE ADVY THRESHOLD WAS NOT QUITE
CATEGORICAL ON THIS SHIFT.
REEDY POINT UPPER DE BAY, LOWER TIDAL DE LINKED: REISSUED FOR LATE
THIS EVENING, SINCE CONFIDENCE IS CATEGORICAL THAT IT WILL REOCCUR,
ESPECIALLY BECAUSE THE FUNNELED ENE FLOW THIS MORNING TURNS LIGHT
SOUTH THIS EVENING.
NJ/DE ATLC COASTS: NO CHANGE IN THE PREVIOUS WARNING. THE TIDAL
SURGE IS EXPECTED TO STAY AROUND 1 TO 1.5 FEET TODAY IN THE
CONTINUING NORTHEASTERLY FLOW. THE THURSDAY EVENING HIGH TIDE SAW
MANY OBSERVING SITES EITHER JUST REACH OR FALL JUST SHY OF
MODERATE FLOODING THRESHOLDS. WE ARE FORECASTING MINOR TIDAL
FLOODING AROUND THIS MORNING`S HIGH TIDE AND MODERATE FLOODING
AROUND THIS FRIDAY EVENING`S HIGH TIDE. RATHER THAN CARRY MULTIPLE
HEADLINES, WE CONTINUED WITH THE COASTAL FLOOD WARNING TO COVER
BOTH HIGH TIDE CYCLES. MINOR TIDAL FLOODING MAY LINGER WITH THE
HIGH TIDE CYCLES ON SATURDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR NJZ012>014-
020>027.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SATURDAY FOR NJZ016.
DE...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR DEZ002>004.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SATURDAY FOR DEZ001.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ452>455.
GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR ANZ450-451.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG/MEOLA
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE/MEOLA
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
953 AM EDT FRI MAY 6 2016
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE INTO OUR AREA FROM THE SOUTHEAST
LATER TODAY, THEN LINGER THROUGH SATURDAY BEFORE DISSIPATING. A COLD
FRONT WILL MOVE THROUGH SUNDAY MORNING, FOLLOWING BY HIGH PRESSURE
SUNDAY NIGHT INTO MONDAY BEFORE MOVING OFFSHORE. A WARM FRONT LIFTS
NORTH ACROSS OUR AREA DURING TUESDAY, THEN STALLS IN OUR AREA
WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME HEAVIER SHOWERS HAVE BEEN TRAVERSING THE REGION THIS MORNING
WITH SCATTERED SHOWERS CONTINUING ACROSS THE AREA. EXPECT THE
HEAVIER RAIN TO CONTINUE TO PUSH TO THE WEST-SOUTHWEST AND OUT OF
THE AREA THIS MORNING. LIGHT TO MODERATE RAIN SHOWERS WILL
CONTINUE THROUGH THE REST OF THE DAY WITH SOME TAPERING OFF
EXPECTED FROM EAST TO WEST LATER IN THE DAY.
SPC HAS EXPANDED THE AREA OF GENERAL THUNDER SO HAVE INCLUDED A
SLIGHT RISK THROUGH THIS AFTERNOON ACROSS THE ENTIRE AREA. CONSIDERABLE
INSTABILITY ALOFT SUGGEST POTENTIAL FOR ISOLATED THUNDER/ASSOCIATED
SMALL HAIL WITH VERY STEEP MID LVL LAPSE RATES AND LOW WBZ NEAR
6000 FT. NOT SURE WHAT WILL TRIGGER THE THUNDER EXCEPT SFC
CONVERGENCE WITH THE LOW COMING ASHORE AND PERHAPS SOME AFTERNOON
SFC HEATING NEAR THE APPROACHING LOW OVER DE. TEMPS MAY BE SEVERAL
DEGREES COLDER THAN YDY I95 NWWD.
A GUSTY NE WIND FOR A TIME THIS MORNING NEAR 20 MPH EXCEPT GUSTS
MIDDAY AND EARLY AFTERNOON MONMOUTH AND OCEAN COUNTIES MAY APPROACH
35 MPH (SEE HRRR GUSTS AS A BAND OF STRONGER WIND WELL NORTH OF
THE LOW CENTER SHIFTS WESTWARD WITH LOW ALONG THE S SHORE OF LI).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HAVE UNCERTAINTY REGARDING TIMING OF ANY SHOWERS AND ANY LEFTOVER
ISOLATED EVENING TSTMS (SE PA/S NJ). CONFIDENCE ON WHAT OCCURS
AND WHERE, IS BELOW AVERAGE. IN PART THIS IS DUE TO RECENT LOSS
OF CONFIDENCE IN GFS QPF FCSTS. NE WIND DIMINISHING THIS EVENING
AND BECOMING LIGHT SOUTHERLY ON THE DELMARVA, POSSIBLY EVEN TO
I95.
FOG MAY BECOME A PROBLEM TONIGHT WITH A LIGHT WIND IN THE MIDST
OF VERTICALLY STACKED MOIST LOW PRESSURE SYSTEM.
FCST WAS A 50 50 BLEND OF THE 00Z/6 GFS/NAM MOS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN INITIAL CLOSED LOW CENTERED
OVER OUR AREA SATURDAY, HOWEVER THIS FEATURE OPENS UP DURING
SATURDAY AS IT SHIFTS EASTWARD. THIS OCCURS AS A STRONG SHORT WAVE
TROUGH DIVES SOUTHEASTWARD ACROSS THE GREAT LAKES SATURDAY AND INTO
THE NORTHEAST SATURDAY NIGHT AND SUNDAY. THE NEW TROUGH AMPLIFIES
ACROSS THE NORTHEAST SUNDAY BEFORE GRADUALLY LIFTING OUT MONDAY. A
WEAK RIDGE THEN ARRIVES FOR EARLY NEXT WEEK WITH A SURFACE WARM
FRONT ALSO MOVING THROUGH. THE WARM FRONT HOWEVER MAY END UP
STALLING IN OUR VICINITY WEDNESDAY AND THURSDAY AS ENERGY SHEARS
EASTWARD ALONG IT. GIVEN THE PATTERN CHANGE, MUCH WARMER AIR IS
EXPECTED TO ARRIVE NEXT WEEK WITH THIS CHANGE STARTING OVER THE
WEEKEND ESPECIALLY DURING SUNDAY. THE EXTENT OF THE WARMING THOUGH
NEXT WEEK WILL DEPEND ON THE PLACEMENT OF THE FRONTAL BOUNDARY AS IT
MAY MEANDER ACROSS OUR CWA AND ALSO PRECIPITATION CHCS. WE USED A
MODEL BLEND APPROACH FOR SATURDAY THROUGH SUNDAY NIGHT, THEN BLENDED
IN THE 00Z WPC GUIDANCE THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR SATURDAY AND SUNDAY...THIS TIME FRAME BEGINS WITH A CLOSED LOW
RIGHT OVER OUR AREA SATURDAY MORNING, HOWEVER THIS FEATURE WILL OPEN
UP AND SHIFT EASTWARD DURING THE COURSE OF THE DAY. THIS WILL BE DUE
TO A KICKER SHORT WAVE TROUGH AMPLIFYING ACROSS THE GREAT LAKES
REGION. A CORE OF -20C TO -24C AIR AT 500 MB IS OVER OUR AREA
SATURDAY MORNING, HOWEVER THIS MODIFIES THROUGH THE DAY AS THE
TROUGH OPENS UP AND SHIFTS TO OUR EAST. THE PRESENCE OF COLD AIR
ALOFT COMBINED WITH SOME LIFT FROM THE CLOSED LOW SHOULD RESULT IN
MAINLY SCATTERED SHOWERS SATURDAY ESPECIALLY INLAND. THE FLOW IS
LIGHT UNDER THE CLOSED LOW THEREFORE SHOWERS SHOULD BE SLOW MOVERS.
SINCE THE AIRMASS IS WARMING DURING THE COURSE OF THE DAY, THIS MAY
MITIGATE THE INSTABILITY POTENTIAL. IT APPEARS ANY INSTABILITY IS
MARGINAL AND THEREFORE THUNDER WAS NOT ADDED FOR SATURDAY ATTM. AS
WE LOSE THE CONTINUOUS ONSHORE FLOW COMPONENT AND THE TROUGH ALOFT
WEAKENING THROUGH SATURDAY, THERE SHOULD BE AT LEAST SOME BREAKS OF
SUNSHINE.
AN AMPLIFYING TROUGH FROM THE GREAT LAKES THEN STARTS TO NEAR OUR
AREA TOWARD DAYBREAK SUNDAY. LOW PRESSURE TRACKING TO OUR NORTH WILL
PULL A COLD FRONT INTO OUR AREA LATE SATURDAY NIGHT AND THIS FRONT
MAY MOVE IN A BIT FASTER. THERE APPEARS TO BE A PLUME OF DEEPER
MOISTURE IN COMBINATION WITH FORCING FOR ASCENT TO DRIVE SOME SHOWERS
/PERHAPS A BAND OF SHOWERS/ ACROSS MUCH OF OUR AREA. THE STRONGEST
FORCING MAY GLANCE OUR NORTHERN AREAS AND THEREFORE THE HIGHEST POPS
WERE PLACED THERE LATER AT NIGHT. ANY SHOWERS SHOULD QUICKLY SHIFT
OFFSHORE SUNDAY MORNING AS THE COLD FRONT ALSO EXITS, THEN DRIER AIR
AND BETTER MIXING WILL PROMOTE SUNSHINE FINALLY RETURNING FOR THE
AFTERNOON. IT WILL BE A BIT BREEZY THOUGH SUNDAY IN THE WAKE OF THE
COLD FRONT AS LOW-LEVEL LAPSE RATES STEEPEN AND THE PRESSURE
GRADIENT TIGHTENS. WE WENT A BIT WARMER THAN MOS FOR SUNDAY
ESPECIALLY FOR THE COASTAL PLAIN GIVEN DOWNSLOPING FLOW. HIGH
PRESSURE THEN STARTS TO ARRIVE SUNDAY NIGHT ALLOWING THE WINDS TO
DIMINISH.
FOR MONDAY AND TUESDAY...SOME WEAK RIDGING ARRIVES DURING MONDAY,
ALLOWING SURFACE HIGH PRESSURE TO BE OVER OUR CWA TO START BUT IT
LOOKS TO SHIFT OFFSHORE LATER MONDAY. THIS WILL ALLOW A SOUTHERLY
FLOW TO BECOME BETTER ESTABLISHED AND WITH DOWNSTREAM WAA
INCREASING, A WARMER TIME FRAME IS EXPECTED. THE WAA WILL BE USHERED
IN VIA A WARM FRONT AS IT CROSSES THE AREA DURING TUESDAY, AND THERE
COULD BE ENOUGH LIFT TO PRODUCE SOME SHOWERS OR A THUNDERSTORM
MAINLY TUESDAY AFTERNOON AND NIGHT. THE FORECAST CHALLENGE IS THAT
THIS FRONT MAY THEN STALL IN OUR AREA AS ENERGY INITIALLY SHEARS
EASTWARD ALONG IT. THIS SHEARING ENERGY COULD PRODUCE SOME
CONVECTION.
FOR WEDNESDAY AND THURSDAY...THE FORECAST CHALLENGE IS WITH THE
FRONTAL ZONE AS IT LOOKS TO BE DRAPED ACROSS OUR AREA, HOWEVER A
TROUGH AMPLIFYING ACROSS NEW ENGLAND WEDNESDAY MAY PUSH THE FRONT
FARTHER SOUTHWARD. THIS SOUTHWARD PUSH COULD BE ENHANCED AS HIGH
PRESSURE MAY BUILD DOWN SOME FROM NORTHERN NEW ENGLAND. A TROUGH IN
THE MIDWEST HOWEVER PUSHES SURFACE LOW PRESSURE UP THE OHIO VALLEY
WEDNESDAY NIGHT INTO THURSDAY, WITH DOWNSTREAM WAA AND SOUTHERLY
FLOW ALLOWING THE BOUNDARY TO START LIFTING NORTHWARD SOME AS A WARM
FRONT. THIS TIME FRAME SHOULD BE ON THE WARMER SIDE, HOWEVER THIS
WILL ULTIMATELY DEPEND ON THE POSITIONING OF THE FRONTAL BOUNDARY
AND ANY CONVECTION THAT OCCURS. GIVEN THE UNCERTAINTY, WE BLENDED
THE 00Z WPC GUIDANCE IN WITH CONTINUITY AND THEN MADE SOME TWEAKS.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...CIGS GENERALLY VARIABLE 600-1600 FT VSBY 1-4 MI IN SHOWERY
RAINS DURING THE MORNING WITH POSSIBLE IMPROVING CONDITIONS
DURING THE AFTERNOON. ISOLATED TSTM POSSIBLE DURING THE MORNING
KACY/KMIV AND THEN DURING THE AFTN ELSEWHERE. TSTMS NOT IN TAF DUE
TO LOW CONFIDENCE AND ISOLATED NATURE. NE WIND...GUSTS 15-23 KT FOR
A TIME LATER THIS MORNING-MIDDAY.
TONIGHT... MVFR/IFR CONDS IN ST/FOG, POSSIBLE CLUSTERS OF SHOWERS.
DIMINISHING NE WIND THIS EVENING NEAR AND N OF I78. OTHERWISE LIGHT
WIND TRENDING SOUTH.
OUTLOOK...
SATURDAY...MVFR/IFR CEILINGS IN THE MORNING SHOULD IMPROVE TO VFR IN
THE AFTERNOON. MAINLY SCATTERED SHOWERS ARE ANTICIPATED WHICH CAN
LOCALLY REDUCE THE VISIBILITY FOR A TIME, THEN A BAND OF SHOWERS
ARRIVES LATE AT NIGHT WITH A COLD FRONT. SOUTHEASTERLY WINDS MAINLY
LESS THAN 10 KNOTS, BECOMING SOUTHWEST AT NIGHT.
SUNDAY...BRIEF MVFR CONDITIONS IN THE MORNING WITH SOME SHOWERS AS A
COLD FRONT MOVES THROUGH, OTHERWISE VFR. WEST TO NORTHWEST WINDS
INCREASE TO 12-18 KNOTS WITH GUSTS TO 25 KNOTS, THEN DIMINISH AT
NIGHT.
MONDAY AND TUESDAY...VFR, THEN POSSIBLY SOME MVFR DURING TUESDAY
WITH A CHANCE OF SHOWERS AS A WARM FRONT MOVES THROUGH. WESTERLY
WINDS AROUND 10 KNOTS MONDAY, BECOMING LIGHT AT NIGHT THEN SHIFTING
TO SOUTHERLY TUESDAY.
&&
.MARINE...
LETTING THE SCA ON THE DELAWARE BAY EXPIRE AS WINDS ARE IN THE
MID TEENS AND NOT EXPECTED TO INCREASE MUCH THROUGH THE REST OF
THE DAY.
SCA CONTINUES OCEAN WATERS THROUGH TONIGHT, ESPECIALLY DUE TO
SEAS.
SMALL CHANCE WE WILL NEED TO UPGRADE TO A SHORT FUSE SHORT DURATION
GALE ANZ450-451 FOR THE PERIOD 16Z-21Z. CONFIDENCE IN UPGRADING
WAS LESS THAN 80 PCT SO HAVE HELD OFF FOR NOW.
FOG MAY BECOME A MARINE HAZARD LATER THIS FRIDAY NIGHT.
OUTLOOK...
SATURDAY...THE WINDS ARE ANTICIPATED TO BE LIGHT AS A CLOSED LOW
INITIALLY OVERHEAD WEAKENS AND THEN SHIFTS EASTWARD. THE SEAS MAY BE
RIGHT AT 5 FEET TO START ESPECIALLY ACROSS THE NORTHERN WATERS BUT
OVERALL THE CONDITIONS SHOULD BE TRENDING BELOW ADVISORY CRITERIA.
THEREFORE WE DID NOT EXTEND THE ADVISORY ATTM.
SUNDAY...WEST TO NORTHWEST WINDS TURN GUSTY TO AROUND 20 KNOTS WITH
SEAS AT OR BELOW 4 FEET. IT IS POSSIBLE WINDS GUST TO 25 KNOTS
NEARSHORE, HOWEVER OVERALL CONDITIONS ARE ANTICIPATED TO BE BELOW
ADVISORY CRITERIA.
MONDAY AND TUESDAY...SUB-ADVISORY CONDITIONS ARE ANTICIPATED DESPITE
SOME INCREASE IN A SOUTHERLY WIND MONDAY AND THEN AGAIN LATER
TUESDAY.
&&
.TIDES/COASTAL FLOODING...
PLEASE SEE THE HAZARD CFW STATEMENT FOR THE PARTICULARS RELATING
TO EACH AREA.
PHL: TIDAL DE ADVY EXPIRED BUT MAY NEED A NEW ONE TO BE ISSUED
THIS AFTERNOON FOR THE EARLY SATURDAY MORNING HIGH TIDE CYCLE.
CONFIDENCE IN EXCEEDING THE ADVY THRESHOLD WAS NOT QUITE
CATEGORICAL ON THIS SHIFT.
REEDY POINT UPPER DE BAY, LOWER TIDAL DE LINKED: REISSUED FOR LATE
THIS EVENING, SINCE CONFIDENCE IS CATEGORICAL THAT IT WILL REOCCUR,
ESPECIALLY BECAUSE THE FUNNELED ENE FLOW THIS MORNING TURNS LIGHT
SOUTH THIS EVENING.
NJ/DE ATLC COASTS: NO CHANGE IN THE PREVIOUS WARNING. THE TIDAL
SURGE IS EXPECTED TO STAY AROUND 1 TO 1.5 FEET TODAY IN THE
CONTINUING NORTHEASTERLY FLOW. THE THURSDAY EVENING HIGH TIDE SAW
MANY OBSERVING SITES EITHER JUST REACH OR FALL JUST SHY OF
MODERATE FLOODING THRESHOLDS. WE ARE FORECASTING MINOR TIDAL
FLOODING AROUND THIS MORNING`S HIGH TIDE AND MODERATE FLOODING
AROUND THIS FRIDAY EVENING`S HIGH TIDE. RATHER THAN CARRY MULTIPLE
HEADLINES, WE CONTINUED WITH THE COASTAL FLOOD WARNING TO COVER
BOTH HIGH TIDE CYCLES. MINOR TIDAL FLOODING MAY LINGER WITH THE
HIGH TIDE CYCLES ON SATURDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR NJZ012>014-
020>027.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SATURDAY FOR NJZ016.
DE...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR DEZ002>004.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SATURDAY FOR DEZ001.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ450>455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG/MEOLA
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE/MEOLA
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
634 AM EDT FRI MAY 6 2016
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE INTO OUR AREA FROM THE SOUTHEAST
LATER TODAY, THEN LINGER THROUGH SATURDAY BEFORE DISSIPATING. A COLD
FRONT WILL MOVE THROUGH SUNDAY MORNING, FOLLOWING BY HIGH PRESSURE
SUNDAY NIGHT INTO MONDAY BEFORE MOVING OFFSHORE. A WARM FRONT LIFTS
NORTH ACROSS OUR AREA DURING TUESDAY, THEN STALLS IN OUR AREA
WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CHILLY SHOWERY RAINS THIS MORNING SHOULD TAPER OFF FROM EAST TO
WEST DURING THE AFTERNOON THOUGH WITH MOIST INFLOW BENEATH A
COOLING 500MB LAYER (-24C NEAR PHL AT 00Z THIS EVENING) WE COULD
SEE LOW TOP SHOWERS CONTINUE DEVELOPING NEAR THE COASTS AND SWEEP
WESTWARD) . CONSIDERABLE INSTABILITY ALOFT SUGGEST POTENTIAL FOR
ISOLATED THUNDER/ASSOCIATED SMALL HAIL WITH VERY STEEP MID LVL
LAPSE RATES AND LOW WBZ NEAR 6000 FT. NOT SURE WHAT WILL TRIGGER
THE THUNDER EXCEPT SFC CONVERGENCE WITH THE LOW COMING ASHORE AND
PERHAPS SOME AFTERNOON SFC HEATING NEAR THE APPROACHING LOW OVER
DE. TEMPS MAY BE SEVERAL DEGREES COLDER THAN YDY I95 NWWD.
A GUSTY NE WIND FOR A TIME THIS MORNING NEAR 20 MPH EXCEPT GUSTS
MIDDAY AND EARLY AFTERNOON MONMOUTH AND OCEAN COUNTIES MAY APPROACH
35 MPH (SEE HRRR GUSTS AS A BAND OF STRONGER WIND WELL NORTH OF
THE LOW CENTER SHIFTS WESTWARD WITH LOW ALONG THE S SHORE OF LI).
FCST WAS A 50 50 BLEND OF THE 00Z/6 GFS/NAM MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HAVE UNCERTAINTY REGARDING TIMING OF ANY SHOWERS AND ANY LEFTOVER
ISOLATED EVENING TSTMS (SE PA/S NJ). CONFIDENCE ON WHAT OCCURS
AND WHERE, IS BELOW AVERAGE. IN PART THIS IS DUE TO RECENT LOSS
OF CONFIDENCE IN GFS QPF FCSTS. NE WIND DIMINISHING THIS EVENING
AND BECOMING LIGHT SOUTHERLY ON THE DELMARVA, POSSIBLY EVEN TO
I95.
FOG MAY BECOME A PROBLEM TONIGHT WITH A LIGHT WIND IN THE MIDST
OF VERTICALLY STACKED MOIST LOW PRESSURE SYSTEM.
FCST WAS A 50 50 BLEND OF THE 00Z/6 GFS/NAM MOS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN INITIAL CLOSED LOW CENTERED
OVER OUR AREA SATURDAY, HOWEVER THIS FEATURE OPENS UP DURING
SATURDAY AS IT SHIFTS EASTWARD. THIS OCCURS AS A STRONG SHORT WAVE
TROUGH DIVES SOUTHEASTWARD ACROSS THE GREAT LAKES SATURDAY AND INTO
THE NORTHEAST SATURDAY NIGHT AND SUNDAY. THE NEW TROUGH AMPLIFIES
ACROSS THE NORTHEAST SUNDAY BEFORE GRADUALLY LIFTING OUT MONDAY. A
WEAK RIDGE THEN ARRIVES FOR EARLY NEXT WEEK WITH A SURFACE WARM
FRONT ALSO MOVING THROUGH. THE WARM FRONT HOWEVER MAY END UP
STALLING IN OUR VICINITY WEDNESDAY AND THURSDAY AS ENERGY SHEARS
EASTWARD ALONG IT. GIVEN THE PATTERN CHANGE, MUCH WARMER AIR IS
EXPECTED TO ARRIVE NEXT WEEK WITH THIS CHANGE STARTING OVER THE
WEEKEND ESPECIALLY DURING SUNDAY. THE EXTENT OF THE WARMING THOUGH
NEXT WEEK WILL DEPEND ON THE PLACEMENT OF THE FRONTAL BOUNDARY AS IT
MAY MEANDER ACROSS OUR CWA AND ALSO PRECIPITATION CHCS. WE USED A
MODEL BLEND APPROACH FOR SATURDAY THROUGH SUNDAY NIGHT, THEN BLENDED
IN THE 00Z WPC GUIDANCE THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR SATURDAY AND SUNDAY...THIS TIME FRAME BEGINS WITH A CLOSED LOW
RIGHT OVER OUR AREA SATURDAY MORNING, HOWEVER THIS FEATURE WILL OPEN
UP AND SHIFT EASTWARD DURING THE COURSE OF THE DAY. THIS WILL BE DUE
TO A KICKER SHORT WAVE TROUGH AMPLIFYING ACROSS THE GREAT LAKES
REGION. A CORE OF -20C TO -24C AIR AT 500 MB IS OVER OUR AREA
SATURDAY MORNING, HOWEVER THIS MODIFIES THROUGH THE DAY AS THE
TROUGH OPENS UP AND SHIFTS TO OUR EAST. THE PRESENCE OF COLD AIR
ALOFT COMBINED WITH SOME LIFT FROM THE CLOSED LOW SHOULD RESULT IN
MAINLY SCATTERED SHOWERS SATURDAY ESPECIALLY INLAND. THE FLOW IS
LIGHT UNDER THE CLOSED LOW THEREFORE SHOWERS SHOULD BE SLOW MOVERS.
SINCE THE AIRMASS IS WARMING DURING THE COURSE OF THE DAY, THIS MAY
MITIGATE THE INSTABILITY POTENTIAL. IT APPEARS ANY INSTABILITY IS
MARGINAL AND THEREFORE THUNDER WAS NOT ADDED FOR SATURDAY ATTM. AS
WE LOSE THE CONTINUOUS ONSHORE FLOW COMPONENT AND THE TROUGH ALOFT
WEAKENING THROUGH SATURDAY, THERE SHOULD BE AT LEAST SOME BREAKS OF
SUNSHINE.
AN AMPLIFYING TROUGH FROM THE GREAT LAKES THEN STARTS TO NEAR OUR
AREA TOWARD DAYBREAK SUNDAY. LOW PRESSURE TRACKING TO OUR NORTH WILL
PULL A COLD FRONT INTO OUR AREA LATE SATURDAY NIGHT AND THIS FRONT
MAY MOVE IN A BIT FASTER. THERE APPEARS TO BE A PLUME OF DEEPER
MOISTURE IN COMBINATION WITH FORCING FOR ASCENT TO DRIVE SOME SHOWERS
/PERHAPS A BAND OF SHOWERS/ ACROSS MUCH OF OUR AREA. THE STRONGEST
FORCING MAY GLANCE OUR NORTHERN AREAS AND THEREFORE THE HIGHEST POPS
WERE PLACED THERE LATER AT NIGHT. ANY SHOWERS SHOULD QUICKLY SHIFT
OFFSHORE SUNDAY MORNING AS THE COLD FRONT ALSO EXITS, THEN DRIER AIR
AND BETTER MIXING WILL PROMOTE SUNSHINE FINALLY RETURNING FOR THE
AFTERNOON. IT WILL BE A BIT BREEZY THOUGH SUNDAY IN THE WAKE OF THE
COLD FRONT AS LOW-LEVEL LAPSE RATES STEEPEN AND THE PRESSURE
GRADIENT TIGHTENS. WE WENT A BIT WARMER THAN MOS FOR SUNDAY
ESPECIALLY FOR THE COASTAL PLAIN GIVEN DOWNSLOPING FLOW. HIGH
PRESSURE THEN STARTS TO ARRIVE SUNDAY NIGHT ALLOWING THE WINDS TO
DIMINISH.
FOR MONDAY AND TUESDAY...SOME WEAK RIDGING ARRIVES DURING MONDAY,
ALLOWING SURFACE HIGH PRESSURE TO BE OVER OUR CWA TO START BUT IT
LOOKS TO SHIFT OFFSHORE LATER MONDAY. THIS WILL ALLOW A SOUTHERLY
FLOW TO BECOME BETTER ESTABLISHED AND WITH DOWNSTREAM WAA
INCREASING, A WARMER TIME FRAME IS EXPECTED. THE WAA WILL BE USHERED
IN VIA A WARM FRONT AS IT CROSSES THE AREA DURING TUESDAY, AND THERE
COULD BE ENOUGH LIFT TO PRODUCE SOME SHOWERS OR A THUNDERSTORM
MAINLY TUESDAY AFTERNOON AND NIGHT. THE FORECAST CHALLENGE IS THAT
THIS FRONT MAY THEN STALL IN OUR AREA AS ENERGY INITIALLY SHEARS
EASTWARD ALONG IT. THIS SHEARING ENERGY COULD PRODUCE SOME
CONVECTION.
FOR WEDNESDAY AND THURSDAY...THE FORECAST CHALLENGE IS WITH THE
FRONTAL ZONE AS IT LOOKS TO BE DRAPED ACROSS OUR AREA, HOWEVER A
TROUGH AMPLIFYING ACROSS NEW ENGLAND WEDNESDAY MAY PUSH THE FRONT
FARTHER SOUTHWARD. THIS SOUTHWARD PUSH COULD BE ENHANCED AS HIGH
PRESSURE MAY BUILD DOWN SOME FROM NORTHERN NEW ENGLAND. A TROUGH IN
THE MIDWEST HOWEVER PUSHES SURFACE LOW PRESSURE UP THE OHIO VALLEY
WEDNESDAY NIGHT INTO THURSDAY, WITH DOWNSTREAM WAA AND SOUTHERLY
FLOW ALLOWING THE BOUNDARY TO START LIFTING NORTHWARD SOME AS A WARM
FRONT. THIS TIME FRAME SHOULD BE ON THE WARMER SIDE, HOWEVER THIS
WILL ULTIMATELY DEPEND ON THE POSITIONING OF THE FRONTAL BOUNDARY
AND ANY CONVECTION THAT OCCURS. GIVEN THE UNCERTAINTY, WE BLENDED
THE 00Z WPC GUIDANCE IN WITH CONTINUITY AND THEN MADE SOME TWEAKS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...CIGS GENERALLY VARIABLE 600-1600 FT VSBY 1-4 MI IN SHOWERY
RAINS DURING THE MORNING WITH POSSIBLE IMPROVING CONDITIONS
DURING THE AFTERNOON. ISOLATED TSTM POSSIBLE DURING THE MORNING
KACY/KMIV AND THEN DURING THE AFTN ELSEWHERE. TSTMS NOT IN TAF DUE
TO LOW CONFIDENCE AND ISOLATED NATURE. NE WIND...GUSTS 15-23 KT FOR
A TIME LATER THIS MORNING-MIDDAY.
TONIGHT... MVFR/IFR CONDS IN ST/FOG, POSSIBLE CLUSTERS OF SHOWERS.
DIMINISHING NE WIND THIS EVENING NEAR AND N OF I78. OTHERWISE LIGHT
WIND TRENDING SOUTH.
OUTLOOK...
SATURDAY...MVFR/IFR CEILINGS IN THE MORNING SHOULD IMPROVE TO VFR IN
THE AFTERNOON. MAINLY SCATTERED SHOWERS ARE ANTICIPATED WHICH CAN
LOCALLY REDUCE THE VISIBILITY FOR A TIME, THEN A BAND OF SHOWERS
ARRIVES LATE AT NIGHT WITH A COLD FRONT. SOUTHEASTERLY WINDS MAINLY
LESS THAN 10 KNOTS, BECOMING SOUTHWEST AT NIGHT.
SUNDAY...BRIEF MVFR CONDITIONS IN THE MORNING WITH SOME SHOWERS AS A
COLD FRONT MOVES THROUGH, OTHERWISE VFR. WEST TO NORTHWEST WINDS
INCREASE TO 12-18 KNOTS WITH GUSTS TO 25 KNOTS, THEN DIMINISH AT
NIGHT.
MONDAY AND TUESDAY...VFR, THEN POSSIBLY SOME MVFR DURING TUESDAY
WITH A CHANCE OF SHOWERS AS A WARM FRONT MOVES THROUGH. WESTERLY
WINDS AROUND 10 KNOTS MONDAY, BECOMING LIGHT AT NIGHT THEN SHIFTING
TO SOUTHERLY TUESDAY.
&&
.MARINE...
SCA CONTINUES OCEAN WATERS AS PREVIOUSLY OUTLINED THROUGH TONIGHT,
ESPECIALLY DUE TO SEAS. DECIDED TO CONTINUE DE BAY SCA SINCE A FEW
GUSTS EARLIER NEAR 23 KT. HOWEVER... TRENDS BY MID MORNING SHOULD
BE DECREASING DE BAY.
SMALL CHANCE WE WILL NEED TO UPGRADE TO A SHORT FUSE SHORT DURATION
GALE ANZ450-451 FOR THE PERIOD 16Z-21Z. CONFIDENCE IN UPGRADING
WAS LESS THAN 80 PCT SO HAVE HELD OFF FOR NOW.
FOG MAY BECOME A MARINE HAZARD LATER THIS FRIDAY NIGHT.
OUTLOOK...
SATURDAY...THE WINDS ARE ANTICIPATED TO BE LIGHT AS A CLOSED LOW
INITIALLY OVERHEAD WEAKENS AND THEN SHIFTS EASTWARD. THE SEAS MAY BE
RIGHT AT 5 FEET TO START ESPECIALLY ACROSS THE NORTHERN WATERS BUT
OVERALL THE CONDITIONS SHOULD BE TRENDING BELOW ADVISORY CRITERIA.
THEREFORE WE DID NOT EXTEND THE ADVISORY ATTM.
SUNDAY...WEST TO NORTHWEST WINDS TURN GUSTY TO AROUND 20 KNOTS WITH
SEAS AT OR BELOW 4 FEET. IT IS POSSIBLE WINDS GUST TO 25 KNOTS
NEARSHORE, HOWEVER OVERALL CONDITIONS ARE ANTICIPATED TO BE BELOW
ADVISORY CRITERIA.
MONDAY AND TUESDAY...SUB-ADVISORY CONDITIONS ARE ANTICIPATED DESPITE
SOME INCREASE IN A SOUTHERLY WIND MONDAY AND THEN AGAIN LATER
TUESDAY.
&&
.TIDES/COASTAL FLOODING...
PLEASE SEE THE HAZARD CFW STATEMENT FOR THE PARTICULARS RELATING
TO EACH AREA.
PHL: TIDAL DE ADVY EXPIRED BUT MAY NEED A NEW ONE TO BE ISSUED
THIS AFTERNOON FOR THE EARLY SATURDAY MORNING HIGH TIDE CYCLE.
CONFIDENCE IN EXCEEDING THE ADVY THRESHOLD WAS NOT QUITE
CATEGORICAL ON THIS SHIFT.
REEDY POINT UPPER DE BAY, LOWER TIDAL DE LINKED: REISSUED FOR LATE
THIS EVENING, SINCE CONFIDENCE IS CATEGORICAL THAT IT WILL REOCCUR,
ESPECIALLY BECAUSE THE FUNNELED ENE FLOW THIS MORNING TURNS LIGHT
SOUTH THIS EVENING.
NJ/DE ATLC COASTS: NO CHANGE IN THE PREVIOUS WARNING. THE TIDAL
SURGE IS EXPECTED TO STAY AROUND 1 TO 1.5 FEET TODAY IN THE
CONTINUING NORTHEASTERLY FLOW. THE THURSDAY EVENING HIGH TIDE SAW
MANY OBSERVING SITES EITHER JUST REACH OR FALL JUST SHY OF
MODERATE FLOODING THRESHOLDS. WE ARE FORECASTING MINOR TIDAL
FLOODING AROUND THIS MORNING`S HIGH TIDE AND MODERATE FLOODING
AROUND THIS FRIDAY EVENING`S HIGH TIDE. RATHER THAN CARRY MULTIPLE
HEADLINES, WE CONTINUED WITH THE COASTAL FLOOD WARNING TO COVER
BOTH HIGH TIDE CYCLES. MINOR TIDAL FLOODING MAY LINGER WITH THE
HIGH TIDE CYCLES ON SATURDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR NJZ012>014-
020>027.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SATURDAY FOR NJZ016.
DE...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR DEZ002>004.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SATURDAY FOR DEZ001.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ450>455.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ431.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG 633
SHORT TERM...DRAG 633
LONG TERM...GORSE
AVIATION...DRAG/GORSE 633
MARINE...DRAG/GORSE 633
TIDES/COASTAL FLOODING...633
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 AM EDT FRI MAY 6 2016
.DISCUSSION...
...UNSEASONABLY COOL THIS MORNING THROUGH TONIGHT...
CURRENT-THIS AFTERNOON... NORTHWEST TO NORTH WIND FLOW BETWEEN
HIGH PRESSURE CENTERED OVER ARKANSAS BUILDING OVER THE NORTHEAST GULF OF
MEXICO AND FLORIDA AND FRONT ASSOCIATED WITH LOW EAST OF THE DELMARVA
PENINSULA AND NEW JERSEY TO CONTINUE THROUGH THE AFTERNOON. LOCAL SEA
BREEZES POSSIBLE FROM NORTH BREVARD CAPE CANAVERAL NORTH MID TO LATE
AFTERNOON PER SHORT TERM SMALL SCALE MODELS SUCH AS THE HRRR AND THE
LOCAL WRFARW6.
CURRENT AFTERNOON WIND GRIDS REFLECT SEA BREEZE. MORNING ZONE UPDATE
WILL CLEAN UP WORDING FOR THE AFTERNOON HOURS.
.AVIATION...VFR. WEST NORTHWEST TO NORTH WINDS 10 TO 15 KNOTS WITH
OCCASIONAL GUSTS 20 TO 25 KNOTS IN THE AFTERNOON. AIRPORTS AND
AIRFIELDS BETWEEN INTERSTATE 95 AND THE COAST FROM COCOA NORTH MAY
EXPERIENCE A MID TO LATE AFTERNOON SEA BREEZE. WINDS FALL TO LIGHT
AGAIN THIS EVENING.
.MARINE...
BUOYS RECORDING NORTHWEST WINDS AROUND 15 KNOTS IN THE ATLANTIC AND
THE COASTAL CMAN SITES WINDS WERE AROUND 10 KNOTS.
THE TWO SCRIPPS BUOYS AT 4 AND 6NM OFF THE BEACH WERE RECORDING 2 TO 3
FEET. THE NOAA BUOYS AT 20NM AND 120NM OFFSHORE WERE RECORDING 5 AND 6
FEET RESPECTIVELY.
CURRENT MARINE FORECAST PICKS UP ON A SEA BREEZE WIND IN THE
NEARSHORE MARINE ZONE FROM CAPE CANAVERAL NORTH.
MORNING UPDATE TO CLEAN UP WORDING AND BRING SEAS DOWN A FOOT OR TWO
FOR THE AFTERNOON PERIOD.
.FIRE WEATHER...
SEVERAL HOURS OF RH`S BETWEEN 25 TO 35 PCT FROM LATE THIS MORNING THRU
THE AFTERNOON AREAWIDE. NO RAIN IN THE FORECAST AND WILL SEE ERC
VALUES SLOWLY INCREASE BUT THEY SHOULD REMAIN TOO LOW FOR RED FLAG
CONDITIONS. 20FT WINDS FROM THE NW AT 10-15 MPH.
.CLIMATE...
RECORD LOWS FOR FRI MAY 6:
DAB 42 1940
MCO 49 1945
MLB 49 1963
VRB 52 1973
RECORD LOWS FOR SAT MAY 7:
DAB 45 1940
MCO 49 1921
MLB 53 1992
VRB 52 2013
PREVIOUS AFD ISSUED AT 320 AM EDT FRI MAY 6 2016
CURRENT...ANOTHER REINFORCING COOL FRONT IS PASSING THROUGH ECFL
EARLY THIS MORNING AS WITNESSED BY WIND SHIFT FROM WEST TO NORTHWEST
AND ON INFRARED SATELLITE IMAGERY BY A THIN CLOUD LINE. THIS WEAK
BOUNDARY WILL USHER IN DRIER/COOLER AIR ACROSS THE AREA IN ITS WAKE.
SKIES REMAIN MOSTLY CLEAR ASIDE FROM A FEW CLOUDS ASSOCIATED ALONG
THE FRONT. LOW TEMPERATURES EARLY THIS MORNING WILL BOTTOM OUT IN
THE 50S AREAWIDE...GENERALLY 5-10 DEGREES LOWER THAN SEASONAL NORMS.
TODAY-TONIGHT...HIGH PRESSURE CENTERED NEAR THE ARKLATEX REGION WILL
SLIDE SOUTH AND EAST ACROSS THE DEEP SOUTH. THE PRESSURE GRADIENT
RELAXES A BIT TODAY AS WNW/NW WINDS INCREASE IN THE LATE MORNING AND
AFTERNOON TO AROUND 15 MPH WITH OCNL HIGHER GUSTS EXPECTED.
THE WIND COMPONENT MAY VEER AROUND TO NNE LATER IN THE AFTERNOON
ALONG THE VOLUSIA COAST. SKIES WILL REMAIN MOSTLY SUNNY WITH NO
THREAT FOR RAIN. ALOFT...A VIGOROUS UPPER TROUGH ALONG THE EASTERN
SEABOARD WILL MOVE ONLY SLIGHTLY EASTWARD SENDING OCNL IMPULSES
ACROSS THE AREA. UNSEASONABLY COOL WITH HIGHS MAINLY 70S AREAWIDE.
OVERNIGHT LOWS STILL BELOW SEASONAL AND GENERALLY IN THE L-M
50S...EXCEPT U50S POSSIBLE ACROSS LARGER METROPOLITAN AREAS OR ALONG
THE IMMEDIATE SPACE/TREASURE COASTS. ANOTHER WEAK BACKDOOR COOL
FRONT WILL BRUSH THE LOCAL COASTAL WATERS LATE OVERNIGHT. THE
ATMOSPHERE WILL REMAIN TOO DRY/STABLE TO PRODUCE ANY PRECIPITATION
OVER LAND.
SAT-TUE...AXIS OF THE DEEP WRN ATLC TROUGH SHIFTS EWD SAT AS THE
OMEGA BLOCK TO THE NORTH BREAKS DOWN. THIS ALLOWS A MID LEVEL RIDGE
TO BUILD EWD ACROSS FL FROM THE GOMEX AND REMAIN ENTRENCHED OVER THE
AREA THROUGH EARLY NEXT WEEK. SURFACE HIGH DRIFTS OVER FL INTO THIS
WEEKEND KEEPING CONDS WX WARM AND DRY BUT NOT TERRIBLY HUMID. HIGH
WILL THEN SLIDE EWD WITH ITS AXIS REMAINING OVER CENTRAL FLORIDA
THROUGH EARLY MON THEN LIFT NORTH OF CTRL FL TUE....RESULTING IN A
TREND TWD MORE HUMID CONDS. ONE MORE DAY/NIGHT OF SLIGHTLY COOLER
THAN NORMAL TEMPS SAT. MAXES NEAR TO A DEGREE OR TWO ABOVE NORMAL
EARLY EXT WEEK WITH MINS RUNNING ABOUT 1-2 CATEGORIES ABOVE CLIMO.
ECFL NORMALS FOR EARLY MAY ARE ABOUT 85-88F/63-66F.
WED-FRI...FOR THE SECOND HALF OF NEXT WEEK...A COUPLE WEAK MID LEVEL
PERTURBATIONS BREAK DOWN THE RIDGE ALOFT WITH LIGHT SE/SRLY FLOW AND
INCREASING MOISTURE ALLOWING FOR A SLGT CHANCE OF DIURNAL SHRA/TS BY
THU (IF NOT WED) PERHAPS A BIT HIGHER BY THE END OF NEXT WEEK. TEMPS
REMAIN NEAR OR SLGTLY ABOVE NORMAL THROUGH THE END OF THE WEEK.
&&
.AVIATION...VFR. WNW/NW WINDS 5-10 KTS EARLY THIS MORNING WILL
INCREASE LATE MORNING/EARLY AFTERNOON TO 10-15 KTS WITH SOME HIGHER
GUSTS. WINDS FALL TO LIGHT AGAIN THIS EVENING.
&&
.MARINE...TODAY-TONIGHT...THE LATEST WEAK FRONTAL BOUNDARY WILL MOVE
THROUGH THE AREA VERY EARLY THIS MORNING WITH ELEVATED NW WINDS 15-
20 KTS CONTINUING OVER THE OPEN ATLC...THOUGH THE PRESSURE GRADIENT
RELAXES THROUGH THE DAY WITH WIND SPEEDS DECREASING THROUGH THE
AFTERNOON. HOWEVER...ANOTHER WEAK FRONTAL TROUGH WILL PASS DOWN THE
COASTAL WATERS LATE TONIGHT WITH WNW/NW WINDS INCREASING TOWARDS
CAUTIONARY CRITERIA ONCE AGAIN. SEAS STARTING 3-4 FT NEAR SHORE AND
5-6 FT OFFSHORE WILL SUBSIDE TO 2-3 FT NEAR SHORE AND AROUND 4 FT
OFFSHORE BY LATE IN THE AFTERNOON.
SAT-TUE...NW-NRLY FLOW WILL DECREASE AS SFC RIDGE BUILDS INTO FL
THROUGH THIS WEEKEND. SEAS OF 3-4FT WILL SUBSIDE TO 2-3FT AS WINDS
DROP AOB 10KT. WINDS WILL TURN LIGHT SRLY MON THEN BACK TO SE AND
INCREASE TO 10-15KT TUE AS RIDGE AXIS SHIFTS NORTH OF CTRL FL. SEAS
OF 2-3FT MON INCREASING BACK TO 3-4FT INTO TUE.
&&
.FIRE WEATHER...TODAY...SEVERAL HOURS OF RH`S BETWEEN 25 TO 35 PCT
FROM LATE THIS MORNING THRU THE AFTERNOON AREAWIDE. NO RAIN IN THE
FORECAST AND WILL SEE ERC VALUES SLOWLY INCREASE BUT THEY SHOULD
REMAIN TOO LOW FOR RED FLAG CONDITIONS. 20FT WINDS FROM THE NW AT
10-15 MPH.
SAT-TUE...SEVERAL HOURS OF CRITICALLY LOW RH VALUES EXPECTED AGAIN
SAT AS HIGH PRES RIDGE AND DRY AIR HOLD SWAY. SHALLOW LATE AFTERNOON
MODIFICATION EXPECTED MAINLY NEAR THE COAST ON SUN DUE TO LOCAL SEA
BREEZE CIRC...HOWEVER CONDITIONS WILL HEIGHTEN FIRE WX SENSITIVITY
AREAWIDE THIS WEEKEND. GRADUAL MODIFICATION CONTINUES MON ONWARD AS
S-SE FLOW ON BACKSIDE OF RETREATING HIGH TAKE HOLD.
&&
.CLIMATE...NEAR RECORD LOWS THIS MORNING IN VRB AND MLB/VRB FOR SAT
MORNING. RECORDS LOOK OUT OF REACH ELSEWHERE.
RECORD LOWS FOR FRI MAY 6:
DAB 42 1940
MCO 49 1945
MLB 49 1963
VRB 52 1973
RECORD LOWS FOR SAT MAY 7:
DAB 45 1940
MCO 49 1921
MLB 53 1992
VRB 52 2013
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 75 56 78 61 / 0 0 0 0
MCO 77 57 81 61 / 0 0 0 0
MLB 77 58 79 62 / 0 0 0 0
VRB 78 56 79 60 / 0 0 0 0
LEE 77 56 81 61 / 0 0 0 0
SFB 77 56 81 60 / 0 0 0 0
ORL 78 59 81 63 / 0 0 0 0
FPR 78 54 79 59 / 0 0 0 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...WIMMER
LONG TERM/IMPACT WX/DSS....KELLY
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1141 AM EDT FRI MAY 6 2016
.UPDATE...
ISSUED AT 1140 AM EDT FRI MAY 6 2016
A COUPLE OF QUICK UPDATES HAVE BEEN DONE TO FINE TUNE THE HOURLY
GRIDS BASED ON OBSERVATIONS AND NEAR TERM MODEL TRENDS. POPS WERE
INCREASED SLIGHTLY FOR THIS AFTERNOON EAST OF A SANDY HOOK TO
JACKSON TO HARLAN LINE FOR BETTER AGREEMENT WITH SHORT TERM MODEL
GUIDANCE...CU DEVELOPMENT AND TRENDS. THE BEST CHANCES FOR ANY
SHOWERS WILL BE IN THE BIG SANDY REGION.
UPDATE ISSUED AT 635 AM EDT FRI MAY 6 2016
JUST A QUICK UPDATE TO FINE TUNE THE GRIDS PER THE LATEST OBS AND
TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 405 AM EDT FRI MAY 6 2016
07Z SFC ANALYSIS SHOWS LOW PRESSURE OFF TO THE EAST OF THE
APPALACHIANS. WHILE HIGH PRESSURE IS FOUND TO THE SOUTHWEST. A FEW
LINGERING LIGHT SHOWERS ARE DRIFTING SOUTH THROUGH FAR EASTERN
KENTUCKY FROM THAT EASTERN LOW. IN CONJUNCTION WITH THIS...LOW
AND MID LEVEL CLOUDS ARE FOUND CLOSER TO THE VIRGINIA AND WEST
VIRGINIA BORDER. IN THE CLEARING TO THE WEST OF THE BORDER
AREAS...PATCHY FOG IS NOTED IN THE SOME OF THE OBSERVATIONS.
TEMPERATURES ARE RUNNING IN THE LOW TO MID 40S ACROSS THE AREA
WITH DEWPOINTS NOT FAR AWAY...WHILE WINDS ARE GENERALLY LIGHT
FROM THE NORTHWEST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A CONUS OMEGA BLOCK
SHIFTING EAST AND OPENING UP DURING THE NEXT 48 HOURS. A DEEP
CLOSED LOW DESCENDING THROUGH THE SOUTHERN APPALACHIANS THIS
MORNING WILL PIVOT TO THE NORTHEAST BY EVENING BEFORE BEING PICKED
UP BY THE NORTHERN STREAM FLOW AND DEPARTING OFF THE MID ATLANTIC
COAST SATURDAY EVENING. IN ITS WAKE...RISING HEIGHTS AND RIDGING
WILL SPREAD FROM THE SOUTHERN PLAINS AND ACROSS THE MISSISSIPPI
VALLEY TOWARD KENTUCKY. HOWEVER...IN ASSOCIATION WITH A HUDSON BAY
UPPER LOW DESCENDING INTO THE GREAT LAKES...A MINOR WAVE WILL
SQUEEZE BY EASTERN KENTUCKY TO THE NORTH LATE SATURDAY. GIVEN THE
MODEL AGREEMENT HAVE FOLLOWED A GENERAL BLEND WITH A STRONG LEAN
TOWARD THE HRRR EARLY ON AND THE NAM12 THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A MILDER DAY THAN YESTERDAY AS SOME
SUNSHINE RETURNS AND THE COLD AIR DEPARTS TO THE EAST. ISOLATED TO
SCATTERED SHOWERS WILL BE FOUND OVER FAR EASTERN KENTUCKY THROUGH
THE AFTERNOON. FOR TONIGHT...EXPECT A SMALL RIDGE TO VALLEY SPLIT
TO SET UP AHEAD OF A DEVELOPING WARM FRONT WITH PATCHY VALLEY FOG
AROUND...SIMILAR TO THIS MORNING. A FEW LIGHT SHOWERS CANNOT BE
RULED OUT WITH THAT BOUNDARY THROUGH THE MORNING...ESPECIALLY EAST
BY MIDDAY SATURDAY. A COLD FRONT WILL THEN SETTLE SOUTH TOWARD
EASTERN KENTUCKY LATER SATURDAY. BETWEEN THESE FEATURES...OUR AREA
WILL BE IN THE WARM SECTOR OF A QUICK MOVING SFC LOW AND AS A
RESULT COULD SEE SOME CONVECTION DEVELOP WITH FAVORABLE PARAMETERS
FOR STRONG TO SEVERE STORMS BUILDING DURING THE AFTERNOON AND
INTO THE EVENING. SPECIFICALLY...CAPE WILL BE MODERATE WITH LOW
LIS AND VEERING/INCREASING WINDS WITH HEIGHT. WILL HIGHLIGHT THIS
FURTHER IN THE FORTHCOMING HWO WITH HAIL AND GUSTY WINDS THE MAIN
THREAT.
USED THE SHORTBLEND/SUPERBLEND AS A STARTING POINT FOR MOST
ELEMENTS WITH SOME MINOR ADJUSTMENTS TO THE AFTERNOON DEWPOINTS
AND SOME TERRAIN DIFFERENCES FOR TEMPERATURES TONIGHT. DID ADJUST
POPS TO BE A BIT ABOVE THE POPULATION SCHEME...IN THE EAST THROUGH
TODAY AND ALSO FOR THE STRONG/SEVERE STORM CONCERNS ON SATURDAY
AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 405 AM EDT FRI MAY 6 2016
THE EXTENDED PORTION OF THE FORECAST BEGINS SATURDAY NIGHT WITH AN
ACTIVE PATTERN IN PLACE. UPPER CLOSED LOW OVER THE SOUTHEASTERN
CANADA REGION WILL BE IN PLACE THROUGH THE WEEKEND AS IT SLOWLY
SHIFTS EAST INTO THE COMING WEEK. THIS FEATURE CONTINUES TO SWING A
FEW SHORTWAVES INTO THE LOWER GREAT LAKES REGION THROUGH THE START
OF THE NEW WEEK. MEANWHILE...AS A WEAKENING RIDGE OVER THE SOUTHEAST
CONTINUES TO WEAKEN AND SHIFT EAST AS WELL WITH ANOTHER UPPER LEVEL
LOW OVER THE CENTRAL PLAINS. THIS FEATURE OPENS AND EJECTS EAST INTO
THE OHIO VALLEY BY MID WEEK. FOLLOWING THIS...TOWARDS THE END OF THE
EXTENDED PERIOD...THE PATTERN BECOMES MORE AMPLIFIED AS ANOTHER
UPPER LOW MOVES INTO THE UPPER PLAINS WITH A WEAKENING RIDGE OVER
THE OH VALLEY SHIFTING. OVERALL...BOTH THE GFS AND EURO HAVE A
DECENT HANDLE ON THE UPPER LEVEL PATTERN THROUGH NEXT WEEK. THOUGH
THE GFS IS A BIT MORE DRIER THAN THE EURO...THE BOTTOM LINE IS THAT
THE EXTENDED SEEMS QUITE WET AND ACTIVE. THIS SOLUTION IS ALSO
CONFIRMED BY THE ALL MODEL BLEND AS WELL KEEPING THE CHANCE OF
PRECIP THROUGH JUST ABOUT EVERY DAY OF THE EXTENDED.
NEAR THE SURFACE HEADING INTO SATURDAY NIGHT AND SUNDAY...A SURFACE
LOW PRESSURE SYSTEM DEVELOPING UP OVER THE CENTRAL PLAINS SETS UP A
WARM FRONT INTO THE MIDWEST AND A QUASI STATIONARY BOUNDARY INTO
THE OH VALLEY. THIS BOUNDARY BECOMES A FOCUS FOR CONTINUED
CONVECTION SATURDAY NIGHT AND SUNDAY. IN FACT...THE EURO MIGHT
SUGGEST AN MCS SET UP FOR THIS TIME PERIOD. INSTABILITY AND SHEAR
SEEM SUBSTANTIAL FOR ORGANIZED CONVECTION AT LEAST EARLY IN THE
SATURDAY NIGHT PERIOD AND AGAIN SUNDAY AFTERNOON FOCUSING ON MAX
HEATING. STRONG CAPPING HEADING INTO THE DAY MONDAY WOULD LIMIT
CONVECTION A BIT MORE AS THE MENTIONED BOUNDARY LIFTS NORTH. STILL
WILL KEEP LOW CHANCE POPS IN THE NORTH CLOSER TO THE BOUNDARY.
TUESDAY...THE SYSTEM OUT WEST SHIFTS EAST WITH STRONG UPPER LEVEL
SUPPORT. STRONG CONVECTION SEEMS TO DEVELOP AHEAD OF THE COLD FRONT
TUESDAY AFTERNOON INTO TUESDAY NIGHT. THIS WILL KEEP LIKELY POPS IN
THE FORECAST THROUGH WEDNESDAY AS GFS MODEL SOUNDINGS KEEP GOOD
INSTABILITY IN PLACE TUESDAY AND WEDNESDAY AFTERNOON. IN FACT...THIS
SYSTEM WILL BE FOLLOWED BY A DISTURBANCE TO MOVE INTO THE AREA ON
THURSDAY. MODELS HIGHLIGHT AN ACTIVE EXTENDED FORECAST THROUGH NEXT
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM EDT FRI MAY 6 2016
THE WORST OF THE AVIATION CONDITIONS WILL BE OVER THE NEXT COUPLE
OF HOURS AS SCATTERED SHOWERS DRIFT JUST WEST OF SOUTH THROUGH THE
FAR EASTERN PARTS OF THE AREA. THESE LOCATIONS...PRIMARILY
SJS...WILL SEE THE BEST SHOT AT MVFR CONDITIONS FOR BOTH VIS AND
CIGS WITH ANY SHOWER. ELSEWHERE...PATCHY FOG MAY IMPACT A TAF SITE
OR TWO WEST OF THE SHOWERS...BUT FOR THE MOST THIS WILL DISSIPATE
UPON SUNRISE ALLOWING VFR CONDITIONS TO PREVAIL FOR THE REST OF
THE PERIOD. WINDS THROUGH THE PERIOD WILL BE GENERALLY OUT OF THE
NORTHWEST AT BETWEEN 5 AND 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
700 AM EDT FRI MAY 6 2016
.UPDATE...
ISSUED AT 635 AM EDT FRI MAY 6 2016
JUST A QUICK UPDATE TO FINE TUNE THE GRIDS PER THE LATEST OBS AND
TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 405 AM EDT FRI MAY 6 2016
07Z SFC ANALYSIS SHOWS LOW PRESSURE OFF TO THE EAST OF THE
APPALACHIANS. WHILE HIGH PRESSURE IS FOUND TO THE SOUTHWEST. A FEW
LINGERING LIGHT SHOWERS ARE DRIFTING SOUTH THROUGH FAR EASTERN
KENTUCKY FROM THAT EASTERN LOW. IN CONJUNCTION WITH THIS...LOW
AND MID LEVEL CLOUDS ARE FOUND CLOSER TO THE VIRGINIA AND WEST
VIRGINIA BORDER. IN THE CLEARING TO THE WEST OF THE BORDER
AREAS...PATCHY FOG IS NOTED IN THE SOME OF THE OBSERVATIONS.
TEMPERATURES ARE RUNNING IN THE LOW TO MID 40S ACROSS THE AREA
WITH DEWPOINTS NOT FAR AWAY...WHILE WINDS ARE GENERALLY LIGHT
FROM THE NORTHWEST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A CONUS OMEGA BLOCK
SHIFTING EAST AND OPENING UP DURING THE NEXT 48 HOURS. A DEEP
CLOSED LOW DESCENDING THROUGH THE SOUTHERN APPALACHIANS THIS
MORNING WILL PIVOT TO THE NORTHEAST BY EVENING BEFORE BEING PICKED
UP BY THE NORTHERN STREAM FLOW AND DEPARTING OFF THE MID ATLANTIC
COAST SATURDAY EVENING. IN ITS WAKE...RISING HEIGHTS AND RIDGING
WILL SPREAD FROM THE SOUTHERN PLAINS AND ACROSS THE MISSISSIPPI
VALLEY TOWARD KENTUCKY. HOWEVER...IN ASSOCIATION WITH A HUDSON BAY
UPPER LOW DESCENDING INTO THE GREAT LAKES...A MINOR WAVE WILL
SQUEEZE BY EASTERN KENTUCKY TO THE NORTH LATE SATURDAY. GIVEN THE
MODEL AGREEMENT HAVE FOLLOWED A GENERAL BLEND WITH A STRONG LEAN
TOWARD THE HRRR EARLY ON AND THE NAM12 THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A MILDER DAY THAN YESTERDAY AS SOME
SUNSHINE RETURNS AND THE COLD AIR DEPARTS TO THE EAST. ISOLATED TO
SCATTERED SHOWERS WILL BE FOUND OVER FAR EASTERN KENTUCKY THROUGH
THE AFTERNOON. FOR TONIGHT...EXPECT A SMALL RIDGE TO VALLEY SPLIT
TO SET UP AHEAD OF A DEVELOPING WARM FRONT WITH PATCHY VALLEY FOG
AROUND...SIMILAR TO THIS MORNING. A FEW LIGHT SHOWERS CANNOT BE
RULED OUT WITH THAT BOUNDARY THROUGH THE MORNING...ESPECIALLY EAST
BY MIDDAY SATURDAY. A COLD FRONT WILL THEN SETTLE SOUTH TOWARD
EASTERN KENTUCKY LATER SATURDAY. BETWEEN THESE FEATURES...OUR AREA
WILL BE IN THE WARM SECTOR OF A QUICK MOVING SFC LOW AND AS A
RESULT COULD SEE SOME CONVECTION DEVELOP WITH FAVORABLE PARAMETERS
FOR STRONG TO SEVERE STORMS BUILDING DURING THE AFTERNOON AND
INTO THE EVENING. SPECIFICALLY...CAPE WILL BE MODERATE WITH LOW
LIS AND VEERING/INCREASING WINDS WITH HEIGHT. WILL HIGHLIGHT THIS
FURTHER IN THE FORTHCOMING HWO WITH HAIL AND GUSTY WINDS THE MAIN
THREAT.
USED THE SHORTBLEND/SUPERBLEND AS A STARTING POINT FOR MOST
ELEMENTS WITH SOME MINOR ADJUSTMENTS TO THE AFTERNOON DEWPOINTS
AND SOME TERRAIN DIFFERENCES FOR TEMPERATURES TONIGHT. DID ADJUST
POPS TO BE A BIT ABOVE THE POPULATION SCHEME...IN THE EAST THROUGH
TODAY AND ALSO FOR THE STRONG/SEVERE STORM CONCERNS ON SATURDAY
AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 405 AM EDT FRI MAY 6 2016
THE EXTENDED PORTION OF THE FORECAST BEGINS SATURDAY NIGHT WITH AN
ACTIVE PATTERN IN PLACE. UPPER CLOSED LOW OVER THE SOUTHEASTERN
CANADA REGION WILL BE IN PLACE THROUGH THE WEEKEND AS IT SLOWLY
SHIFTS EAST INTO THE COMING WEEK. THIS FEATURE CONTINUES TO SWING A
FEW SHORTWAVES INTO THE LOWER GREAT LAKES REGION THROUGH THE START
OF THE NEW WEEK. MEANWHILE...AS A WEAKENING RIDGE OVER THE SOUTHEAST
CONTINUES TO WEAKEN AND SHIFT EAST AS WELL WITH ANOTHER UPPER LEVEL
LOW OVER THE CENTRAL PLAINS. THIS FEATURE OPENS AND EJECTS EAST INTO
THE OHIO VALLEY BY MID WEEK. FOLLOWING THIS...TOWARDS THE END OF THE
EXTENDED PERIOD...THE PATTERN BECOMES MORE AMPLIFIED AS ANOTHER
UPPER LOW MOVES INTO THE UPPER PLAINS WITH A WEAKENING RIDGE OVER
THE OH VALLEY SHIFTING. OVERALL...BOTH THE GFS AND EURO HAVE A
DECENT HANDLE ON THE UPPER LEVEL PATTERN THROUGH NEXT WEEK. THOUGH
THE GFS IS A BIT MORE DRIER THAN THE EURO...THE BOTTOM LINE IS THAT
THE EXTENDED SEEMS QUITE WET AND ACTIVE. THIS SOLUTION IS ALSO
CONFIRMED BY THE ALL MODEL BLEND AS WELL KEEPING THE CHANCE OF
PRECIP THROUGH JUST ABOUT EVERY DAY OF THE EXTENDED.
NEAR THE SURFACE HEADING INTO SATURDAY NIGHT AND SUNDAY...A SURFACE
LOW PRESSURE SYSTEM DEVELOPING UP OVER THE CENTRAL PLAINS SETS UP A
WARM FRONT INTO THE MIDWEST AND A QUASI STATIONARY BOUNDARY INTO
THE OH VALLEY. THIS BOUNDARY BECOMES A FOCUS FOR CONTINUED
CONVECTION SATURDAY NIGHT AND SUNDAY. IN FACT...THE EURO MIGHT
SUGGEST AN MCS SET UP FOR THIS TIME PERIOD. INSTABILITY AND SHEAR
SEEM SUBSTANTIAL FOR ORGANIZED CONVECTION AT LEAST EARLY IN THE
SATURDAY NIGHT PERIOD AND AGAIN SUNDAY AFTERNOON FOCUSING ON MAX
HEATING. STRONG CAPPING HEADING INTO THE DAY MONDAY WOULD LIMIT
CONVECTION A BIT MORE AS THE MENTIONED BOUNDARY LIFTS NORTH. STILL
WILL KEEP LOW CHANCE POPS IN THE NORTH CLOSER TO THE BOUNDARY.
TUESDAY...THE SYSTEM OUT WEST SHIFTS EAST WITH STRONG UPPER LEVEL
SUPPORT. STRONG CONVECTION SEEMS TO DEVELOP AHEAD OF THE COLD FRONT
TUESDAY AFTERNOON INTO TUESDAY NIGHT. THIS WILL KEEP LIKELY POPS IN
THE FORECAST THROUGH WEDNESDAY AS GFS MODEL SOUNDINGS KEEP GOOD
INSTABILITY IN PLACE TUESDAY AND WEDNESDAY AFTERNOON. IN FACT...THIS
SYSTEM WILL BE FOLLOWED BY A DISTURBANCE TO MOVE INTO THE AREA ON
THURSDAY. MODELS HIGHLIGHT AN ACTIVE EXTENDED FORECAST THROUGH NEXT
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 700 AM EDT FRI MAY 6 2016
THE WORST OF THE AVIATION CONDITIONS WILL BE OVER THE NEXT COUPLE
OF HOURS AS SCATTERED SHOWERS DRIFT JUST WEST OF SOUTH THROUGH THE
FAR EASTERN PARTS OF THE AREA. THESE LOCATIONS...PRIMARILY
SJS...WILL SEE THE BEST SHOT AT MVFR CONDITIONS FOR BOTH VIS AND
CIGS WITH ANY SHOWER. ELSEWHERE...PATCHY FOG MAY IMPACT A TAF SITE
OR TWO WEST OF THE SHOWERS...BUT FOR THE MOST THIS WILL DISSIPATE
UPON SUNRISE ALLOWING VFR CONDITIONS TO PREVAIL FOR THE REST OF
THE PERIOD. WINDS THROUGH THE PERIOD WILL BE GENERALLY OUT OF THE
NORTHWEST AT BETWEEN 5 AND 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
656 AM CDT FRI MAY 6 2016
.UPDATE...
ISSUED AT 558 AM CDT FRI MAY 6 2016
ISOLATED THUNDERSTORMS HAVE EXPANDED A LITTLE IN COVERAGE ACROSS
SOUTHEAST SOUTH DAKOTA...AND MAY CLIP KNOX/CEDAR COUNTIES EARLY
THIS MORNING. NO MODEL HAD A REAL HANDLE ON THIS...WITH MOST
RECENT RUNS OF THE OPERATIONAL HRRR FINALLY CATCHING ON BY 09Z.
NOTHING MORE THAN A PASSING SPRINKLE...MAYBE WITH A RUMBLE OF THUNDER.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 252 AM CDT FRI MAY 6 2016
QUIET AND VERY WARM WEATHER TODAY...THEN MORE ACTIVE AND WET
WEATHER SATURDAY AND SUNDAY.
UPPER RIDGE REMAINS FIRM ACROSS THE WESTERN HIGH PLAINS WITH
CLOSED LOWS ACROSS BOTH COASTS. THIS RESULTS IN ONE MORE DRY DAY
WITH BREEZY SOUTHERLY WINDS DEVELOPING TODAY WITH MOSTLY SUNNY
SKIES. GUIDANCE REMAINS VERY WARM TODAY WITH HIGHS PROBABLY
REACHING THE LOWER TO MID 80S. THIS WILL RESULT IN AFTERNOON
HUMIDITY DROPPING INTO THE UPPER 20S TO LOWER 30S...BUT STILL TOO
HIGH FOR ANY RED FLAG FIRE CONCERNS. THESE HIGHS ARE ALSO WELL
BELOW ANY MAX TEMP RECORDS TODAY WHICH RANGE FROM 95 TO 101.
THERE IS A COLD FRONT MOVING OUT OF THE NORTHERN ROCKIES...AND
WILL CONTINUE TO BE PUSHED BY AN UPPER TROUGH MOVING THROUGH
CENTRAL CANADA. THIS FRONT SETTLES SOUTHWARD INTO THE FORECAST
AREA TOWARD I80 THROUGH DAYBREAK SATURDAY. THIS COULD RESULT IN A
SLIGHT CHANCE OF THUNDERSTORMS GENERALLY ALONG/NORTH OF IT AFTER
MIDNIGHT. PRECIP COULD VERY WELL EVEN REMAIN JUST NORTH OF THE
AREA TONIGHT ACROSS SOUTHERN SOUTH DAKOTA.
SATURDAY...THE FRONT SETTLES A LITTLE FURTHER SOUTH BUT NOT MUCH.
THIS SETS UP A PRETTY TIGHT TEMPERATURE GRADIENT FROM SOUTH TO
NORTH. HIGHS NORTH OF THE FRONT IN THE MID 60S...BUT NEAR 80 ALONG
THE KS/NE BORDER. THERE COULD BE ISOLATED REMNANTS FROM ANY
CONVECTION NORTH OF THE BOUNDARY SATURDAY MORNING. BUT...AGAIN IT
COULD ALSO BE DRY AS UPPER RIDGING REMAINS IN PLACE...WITH NO
SIGNIFICANT FORCING OTHERWISE. WITH THE FRONT BECOMING STATIONARY
ACROSS SOUTHERN NEBRASKA SATURDAY AFTERNOON...INSTABILITY DOES
BUILD NEAR IT. A WEAK CAP MAY HOLD WITH CONVECTION DEVELOPING
FURTHER WEST ACROSS THE WESTERN HIGH PLAINS. WILL MAINTAIN A
SLIGHT CHANCE OF THUNDERSTORMS SATURDAY AFTERNOON...BUT MOST AREAS
WILL PROBABLY REMAIN DRY. IF A STORM WOULD DEVELOP...THERE IS JUST
A MARGINAL RISK THAT IT COULD BE SEVERE.
SATURDAY NIGHT NIGHT...ELEVATED CONVECTION MAY DEVELOP NORTH OF
THE SURFACE FRONT AS DEPICTED BY VARIOUS MODELS. HOWEVER...THE NAM
IS ALSO HINTING THAT A WEAK PIECE OF ENERGY EJECTING FROM THE MAIN
LOW ACROSS THE CENTRAL ROCKIES MAY BE ENOUGH TO TRIGGER SCATTERED
SHOWERS AND THUNDERSTORMS. THUS WILL MAINTAIN CHANCE POPS SATURDAY
NIGHT.
SUNDAY IS TRICKY AS MODEL ARE NOT IN GOOD AGREEMENT ON PLACEMENT
OF CONVECTION THROUGH THE DAY. THERE COULD BE LINGERING ACTIVITY
EARLY SUNDAY MORNING. STRONGER STORMS COULD DEVELOP SUNDAY AFTERNOON
AS LOW LEVEL MOISTURE CONTINUES TO BUILD WITH DEWPOINTS RISING
INTO THE MID TO UPPER 50S AND POSSIBLY EVEN LOWER 60S. ANY MORNING
CONVECTION COULD HAVE IMPLICATIONS ON AFTERNOON DEVELOPMENT...
THUS CONFIDENCE IS LOW OF THE DETAILS AT THIS POINT.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 252 AM CDT FRI MAY 6 2016
PRECIP CHANCE SUBSTANTIALLY INCREASE SUNDAY NIGHT AS UPPER LOW
BEGINS TO MOVE ONTO THE PLAINS AND FRONTAL BOUNDARY SHIFTS
NORTHWARD ACROSS THE FORECAST AREA. WILL HAVE TO WATCH FOR SEVERE
STORMS SUNDAY EVENING...AND MAYBE EVEN OVERNIGHT AS ELEVATED
STORMS WILL STILL BE POSSIBLE. ONE HALF TO ONE AND ONE HALF INCHES
OF RAIN WILL ALSO BE POSSIBLE SUNDAY NIGHT ACROSS THE REGION. PW
VALUES INCREASE TO ABOUT 1.5 STANDARD DEVIATIONS ABOVE NORMAL
BASED ON NAEFS CLIMATOLOGY DURING THIS TIME.
THUNDERSTORM CHANCES REMAIN IN THE LIKELY CATEGORY THROUGH MONDAY
AS SURFACE LOW/FRONTAL BOUNDARY REMAIN IN THE REGION. COULD ALSO
BE A SEVERE RISK ON MONDAY AS WELL...WITH PRECIP THREAT CONTINUING
INTO MONDAY NIGHT AS THE FRONT SHIFTS EASTWARD.
TUESDAY WILL MAINTAIN A SMALL CHANCE OF SHOWERS/ISOLATED
STORMS BASED ON OLDER MODEL BLENDS...BUT REALLY THE NEWER MODELS
ARE SHOWING IT COULD BE DRY AS WE ARE BETWEEN SYSTEMS. ANOTHER
WEAK WAVE COULD MOVE INTO THE AREA ON WEDNESDAY WHICH MAY BRING
ONE MORE SMALL CHANCE OF SHOWERS/ISOLATED STORMS...WITH DRY
WEATHER THURSDAY.
&&
.AVIATION...(12Z TAFS FOR KOMA...KLNK...KOFK THROUGH 12Z SATURDAY)
ISSUED AT 627 AM CDT FRI MAY 6 2016
VFR CONDITIONS THROUGH THE TAF PERIOD. A FEW SHOWERS WITH ISOLATED
THUNDER DEVELOPED WITH A LOW LEVEL JET IN SOUTH DAKOTA. THESE
COULD LAST ANOTHER A COUPLE HOURS...BUT TOO SMALL A CHANCE TO
INCLUDE AT KOFK. SOUTH WINDS WILL INCREASE TO 12 TO 18KT WITH
GUSTS TO 25KTS...THEN DECREASES TO 5 TO 10 KTS THIS EVENING. A
LOW LEVEL JET WILL INCREASE TO 45KTS LATER TONIGHT NEAR KLNK.
THIS COULD SPARK A FEW STORMS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DEWALD
SHORT TERM...DEWALD
LONG TERM...DEWALD
AVIATION...ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
600 AM CDT FRI MAY 6 2016
.UPDATE...
ISSUED AT 558 AM CDT FRI MAY 6 2016
ISOLATED THUNDERSTORMS HAVE EXPANDED A LITTLE IN COVERAGE ACROSS
SOUTHEAST SOUTH DAKOTA...AND MAY CLIP KNOX/CEDAR COUNTIES EARLY
THIS MORNING. NO MODEL HAD A REAL HANDLE ON THIS...WITH MOST
RECENT RUNS OF THE OPERATIONAL HRRR FINALLY CATCHING ON BY 09Z.
NOTHING MORE THAN A PASSING SPRINKLE...MAYBE WITH A RUMBLE OF THUNDER.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 252 AM CDT FRI MAY 6 2016
QUIET AND VERY WARM WEATHER TODAY...THEN MORE ACTIVE AND WET
WEATHER SATURDAY AND SUNDAY.
UPPER RIDGE REMAINS FIRM ACROSS THE WESTERN HIGH PLAINS WITH
CLOSED LOWS ACROSS BOTH COASTS. THIS RESULTS IN ONE MORE DRY DAY
WITH BREEZY SOUTHERLY WINDS DEVELOPING TODAY WITH MOSTLY SUNNY
SKIES. GUIDANCE REMAINS VERY WARM TODAY WITH HIGHS PROBABLY
REACHING THE LOWER TO MID 80S. THIS WILL RESULT IN AFTERNOON
HUMIDITY DROPPING INTO THE UPPER 20S TO LOWER 30S...BUT STILL TOO
HIGH FOR ANY RED FLAG FIRE CONCERNS. THESE HIGHS ARE ALSO WELL
BELOW ANY MAX TEMP RECORDS TODAY WHICH RANGE FROM 95 TO 101.
THERE IS A COLD FRONT MOVING OUT OF THE NORTHERN ROCKIES...AND
WILL CONTINUE TO BE PUSHED BY AN UPPER TROUGH MOVING THROUGH
CENTRAL CANADA. THIS FRONT SETTLES SOUTHWARD INTO THE FORECAST
AREA TOWARD I80 THROUGH DAYBREAK SATURDAY. THIS COULD RESULT IN A
SLIGHT CHANCE OF THUNDERSTORMS GENERALLY ALONG/NORTH OF IT AFTER
MIDNIGHT. PRECIP COULD VERY WELL EVEN REMAIN JUST NORTH OF THE
AREA TONIGHT ACROSS SOUTHERN SOUTH DAKOTA.
SATURDAY...THE FRONT SETTLES A LITTLE FURTHER SOUTH BUT NOT MUCH.
THIS SETS UP A PRETTY TIGHT TEMPERATURE GRADIENT FROM SOUTH TO
NORTH. HIGHS NORTH OF THE FRONT IN THE MID 60S...BUT NEAR 80 ALONG
THE KS/NE BORDER. THERE COULD BE ISOLATED REMNANTS FROM ANY
CONVECTION NORTH OF THE BOUNDARY SATURDAY MORNING. BUT...AGAIN IT
COULD ALSO BE DRY AS UPPER RIDGING REMAINS IN PLACE...WITH NO
SIGNIFICANT FORCING OTHERWISE. WITH THE FRONT BECOMING STATIONARY
ACROSS SOUTHERN NEBRASKA SATURDAY AFTERNOON...INSTABILITY DOES
BUILD NEAR IT. A WEAK CAP MAY HOLD WITH CONVECTION DEVELOPING
FURTHER WEST ACROSS THE WESTERN HIGH PLAINS. WILL MAINTAIN A
SLIGHT CHANCE OF THUNDERSTORMS SATURDAY AFTERNOON...BUT MOST AREAS
WILL PROBABLY REMAIN DRY. IF A STORM WOULD DEVELOP...THERE IS JUST
A MARGINAL RISK THAT IT COULD BE SEVERE.
SATURDAY NIGHT NIGHT...ELEVATED CONVECTION MAY DEVELOP NORTH OF
THE SURFACE FRONT AS DEPICTED BY VARIOUS MODELS. HOWEVER...THE NAM
IS ALSO HINTING THAT A WEAK PIECE OF ENERGY EJECTING FROM THE MAIN
LOW ACROSS THE CENTRAL ROCKIES MAY BE ENOUGH TO TRIGGER SCATTERED
SHOWERS AND THUNDERSTORMS. THUS WILL MAINTAIN CHANCE POPS SATURDAY
NIGHT.
SUNDAY IS TRICKY AS MODEL ARE NOT IN GOOD AGREEMENT ON PLACEMENT
OF CONVECTION THROUGH THE DAY. THERE COULD BE LINGERING ACTIVITY
EARLY SUNDAY MORNING. STRONGER STORMS COULD DEVELOP SUNDAY AFTERNOON
AS LOW LEVEL MOISTURE CONTINUES TO BUILD WITH DEWPOINTS RISING
INTO THE MID TO UPPER 50S AND POSSIBLY EVEN LOWER 60S. ANY MORNING
CONVECTION COULD HAVE IMPLICATIONS ON AFTERNOON DEVELOPMENT...
THUS CONFIDENCE IS LOW OF THE DETAILS AT THIS POINT.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 252 AM CDT FRI MAY 6 2016
PRECIP CHANCE SUBSTANTIALLY INCREASE SUNDAY NIGHT AS UPPER LOW
BEGINS TO MOVE ONTO THE PLAINS AND FRONTAL BOUNDARY SHIFTS
NORTHWARD ACROSS THE FORECAST AREA. WILL HAVE TO WATCH FOR SEVERE
STORMS SUNDAY EVENING...AND MAYBE EVEN OVERNIGHT AS ELEVATED
STORMS WILL STILL BE POSSIBLE. ONE HALF TO ONE AND ONE HALF INCHES
OF RAIN WILL ALSO BE POSSIBLE SUNDAY NIGHT ACROSS THE REGION. PW
VALUES INCREASE TO ABOUT 1.5 STANDARD DEVIATIONS ABOVE NORMAL
BASED ON NAEFS CLIMATOLOGY DURING THIS TIME.
THUNDERSTORM CHANCES REMAIN IN THE LIKELY CATEGORY THROUGH MONDAY
AS SURFACE LOW/FRONTAL BOUNDARY REMAIN IN THE REGION. COULD ALSO
BE A SEVERE RISK ON MONDAY AS WELL...WITH PRECIP THREAT CONTINUING
INTO MONDAY NIGHT AS THE FRONT SHIFTS EASTWARD.
TUESDAY WILL MAINTAIN A SMALL CHANCE OF SHOWERS/ISOLATED
STORMS BASED ON OLDER MODEL BLENDS...BUT REALLY THE NEWER MODELS
ARE SHOWING IT COULD BE DRY AS WE ARE BETWEEN SYSTEMS. ANOTHER
WEAK WAVE COULD MOVE INTO THE AREA ON WEDNESDAY WHICH MAY BRING
ONE MORE SMALL CHANCE OF SHOWERS/ISOLATED STORMS...WITH DRY
WEATHER THURSDAY.
&&
.AVIATION...(06Z TAFS FOR KOMA...KLNK...KOFK THROUGH 06Z SATURDAY)
ISSUED AT 1043 PM CDT THU MAY 5 2016
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF CYCLE. SOUTHERLY
RETURN FLOW AROUND DEPARTING SURFACE HIGH PRESSURE WILL ALLOW
WINDS TO INCREASE THROUGH THE DAY FRIDAY. A FEW CLOUDS MID CLOUDS
MAY DEVELOP LATE IN THE PERIOD BUT REMAIN VFR.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DEWALD
SHORT TERM...DEWALD
LONG TERM...DEWALD
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
850 AM PDT FRI MAY 6 2016
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE INTO SOUTHERN NEVADA PROVIDING
SCATTERED SHOWERS AND THUNDERSTORMS ALONG WITH MUCH COOLER
TEMPERATURES THROUGH SUNDAY. DRIER CONDITIONS ALONG WITH A WARMING
TREND WILL OCCUR NEXT WEEK WITH TEMPERATURES WELL ABOVE NORMAL BY
THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...A RELATIVELY SMALL BAND OF THUNDERSTORMS IGNITED OVER
SOUTHERN AND CENTRAL CLARK COUNTY THIS MORNING WHILE MOSTLY CLEAR
SKIES WERE EVIDENT ON EITHER SIDE OF IT. SMALL HAIL AND RAINFALL
AMOUNTS UP TO A QUARTER-INCH HAVE BEEN OBSERVED IN THE LAS VEGAS
VALLEY SO FAR THIS MORNING. THE LATEST HRRR DEPICTS THAT THIS BAND
WILL EXPAND FROM NORTHWEST ARIZONA ACROSS MUCH OF SOUTHERN AND SOUTH
CENTRAL NEVADA THE REST OF THE MORNING THROUGH THE AFTERNOON...CLOSE
TO WHAT WAS ALREADY INDICATED IN THE INHERITED GRIDS. THE CENTER OF
THE INCOMING CLOSED LOW WAS NEAR ANAHEIM THIS MORNING AND CONVECTION
NEAR THIS CENTER SHOULD SPREAD ACROSS SOUTHWEST SAN BERNARDINO
COUNTY THIS AFTERNOON. THE POP/WX GRIDS WERE UPDATED TO REFLECT
THESE LATEST TRENDS. THE REST OF THE FORECAST DETAILED IN THE
PREVIOUS DISCUSSION LOOK ON TRACK.
&&
.AVIATION...FOR MCCARRAN...THIS MORNINGS BAND OF RAINSHOWERS AND
THUNDERSTORMS HAVE PUSHED NORTH OVER THE LAS VEGAS AREA. CLEARING
SKIES FOR THE REST OF THE MORNING WILL LEAD TO ANOTHER ROUND OF
SHOWER AND THUNDERSTORMS BEGINNING EARLY THIS AFTERNOON (AFT 20Z).
THESE SHOULD AFFECT THE MCCARRAN TERMINAL UNTIL ABOUT 00Z. WINDS
SHOULD REMAIN IN A SOUTHERLY TO SOUTHWESTERLY DIRECTION FOR MOST OF
THE DAY EXCEPT IN THE VICINITY OF THUNDERSTORMS WHERE WINDS
COULD BE GUSTY AND ERRATIC.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...CLOUDS AND SHOWER ACTIVITY WILL INCREASE THROUGHOUT THE
DAY WITH THUNDERSTORMS ALSO POSSIBLE...ESPECIALLY THIS AFTERNOON AND
EARLY EVENING. GUSTY AND ERRATIC WINDS ARE POSSIBLE AROUND SHOWERS
AND THUNDERSTORMS. OTHERWISE...EXPECTING MAINLY A SOUTHERLY WIND
ACROSS THE AREA 10-15 KTS AND SOME GUSTS AROUND 20 KTS. CIGS WITH
SHOWERS MAINLY 5-7K FT BUT COULD DROP AS LOW AS 3K FT.
&&
.PREV DISCUSSION...
250 AM PDT FRI MAY 6 2016
.SHORT TERM...THROUGH SUNDAY NIGHT.
UPPER LOW IS EXPECTED TO MOVE INTO SOUTHERN CALIFORNIA/SOUTHERN
NEVADA DURING THE DAY PROVING ENOUGH MOISTURE AND ENERGY FOR
SCATTERED SHOWERS AND THUNDERSTORMS. THERE HAS BEEN FAIRLY
PERSISTENT ACTIVITY THIS MORNING ACROSS NORTHERN INYO AND ESMERALDA
COUNTIES WHERE THE BEST FORCING HAS BEEN LOCATED. RAINFALL AMOUNTS
HAVE GENERALLY BEEN MARGINAL AS THESE CELLS HAVE BEEN MOVING FAIRLY
QUICKLY. ADDITIONAL ISOLATED SHOWERS HAVE BEEN DEVELOPING ACROSS THE
EASTERN HALF OF THE CWA OVERNIGHT...BUT FORCING OVER THIS AREA HAS
BEEN MUCH WEAKER AND THESE CELLS ARE NOT LASTING TOO LONG. LOOKS
LIKE MOST OF THE SOUTHERN TWO THIRDS OF THE CWA WILL START OUT WITH
MOSTLY SUNNY SKIES...BUT CLOUDS WILL QUICKLY DEVELOP AS THE
ATMOSPHERE BECOME MORE UNSTABLE AS THE DAY WEARS ON. LI VALUES ARE
EXPECTED TO DROP TO AROUND 0/-3 BY EARLY AFTERNOON AND CAPE VALUES
WILL ALSO INCREASE. THIS WILL LEAD TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER MUCH OF THE REGION. PW VALUES ARE FORECAST TO BE
AROUND 0.50-0.65 INCHES SO SOME OF THE HEAVIER STORMS COULD PRODUCE
PERIODS OF HEAVY RAIN. WITH THE UPPER LOW DIRECTLY OVERHEAD SNOW
LEVELS ARE EXPECTED TO BE DOWN TO AROUND 6500-7000 FEET AND ITS
LIKELY SOME OF THE HIGHER PEAKS WILL SEE A FEW INCHES OF NEW SNOW.
THE BEST SHEAR VALUES WILL REMAIN ACROSS LINCOLN...CENTRAL NYE...
ESMERALDA...AND NORTHERN INYO COUNTIES THROUGH THE DAY. THIS AREA
COULD SEE MORE PERSISTENT STORMS WITH SOME STRONG STORMS POSSIBLE.
WITH THE COLD UPPER LEVELS SMALL HAIL WILL ALSO BE POSSIBLE WITH ANY
STORM.
WITH LOSS OF DAYTIME HEATING WE WILL LOSE SOME OF THE ENERGY FOR
STORMS TO CONTINUE...HOWEVER WITH THE DYNAMICS OF THE UPPER LOW
OVERHEAD ITS LIKELY THAT A FEW SHOWERS AND THUNDERSTORMS WILL
PERSIST OVERNIGHT. THE UPPER LOW WILL STILL BE OVERHEAD ON SATURDAY
LEADING TO ANOTHER DAY OF SCATTERED MAINLY AFTERNOON SHOWERS AND
THUNDERSTORMS. CONDITIONS ARE NOT EXPECTED TO BE AS UNSTABLE AS WE
SAW ON FRIDAY...BUT STILL ENOUGH TO GENERATE SCATTERED STORMS.
ONCE AGAIN SMALL HAIL AND HEAVY RAIN WILL BE POSSIBLE WITH ANY
STORM.
TEMPERATURES WILL COOL SIGNIFICANTLY WITH HIGHS TODAY ABOUT 15
DEGREES COLDER THAN WE SAW ON THURSDAY. ONLY SLIGHTLY WARMER
CONDITIONS ON SATURDAY...BUT BY SUNDAY AFTERNOON READINGS SHOULD
JUMP ABOUT 7-9 DEGREES.
.LONG TERM...MONDAY THROUGH THURSDAY.
THE UPPER LOW WILL BE OFF TO THE EAST BY MONDAY WITH A WEAK
NORTHWEST FLOW OVER THE AREA AND RIDGING OFF THE CALIFORNIA COAST.
THE MODELS ARE GENERALLY IN AGREEMENT KEEPING A BIT OF MOISTURE
LINGERING ALONG WITH SOME WEAK INSTABILITY KEEPING A SLIGHT CHANCE
OF SHOWERS OVER MAINLY LINCOLN AND MOHAVE COUNTY. TEMPERATURES WILL
BEGIN TO WARM SIGNIFICANTLY. THE MODELS KEEP A WEAK CYCLONIC
NORTHWEST FLOW AROUND TUESDAY AND WEDNESDAY AS WELL AND NOT REALLY
FLUSHING OUT THE LINGERING MOISTURE. STILL CANNOT RULE OUT A SLIGHT
CHANCE OF AFTERNOON SHOWERS OVER THE SIERRA AND POSSIBLY THE HIGHER
TERRAIN OF LINCOLN COUNTY AS WELL. MOST MODELS TREND TOWARD WEAK
RIDGING BY THURSDAY BUT STILL KEEP ENOUGH MOISTURE AROUND FOR A
SLIGHT CHANCE OF SHOWERS OVER THE SIERRA IN THE AFTERNOON.
TEMPERATURES CONTINUE TO WARM THROUGH THE LONG TERM WITH HIGH
TEMPERATURES AROUND 5 DEGREES ABOVE NORMAL BY THURSDAY.
&&
.SPOTTER INFORMATION STATEMENT...ACTIVE WEATHER IS EXPECTED THROUGH
THE WEEKEND. SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT
WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES.
&&
$$
UPDATE...ADAIR
SHORT TERM...GORELOW
LONG TERM/AVIATION...HARRISON
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
!--NOT SENT--!
AREA FORECAST DISCUSSION
NWS MEDFORD OR
502 AM PDT FRI MAY 6 2016
.AVIATION...FOR THE 06/12Z TAF CYCLE...A MIX OF MVFR AND VFR
CONDITIONS WILL CONTINUE THROUGH LATE MORNING AT ALL TERMINALS.
SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE EAST SIDE EARLY
THIS AFTERNOON AND THEN MOVE FROM EAST TO WEST ACROSS THE AREA.
THE GREATEST THREAT FOR THUNDERSTORMS IS FROM THE
CASCADES/SISKIYOUS EAST, BUT STORMS MAY ADVANCE AS FAR WEST AS
JACKSON/JOSEPHINE COUNTY (INCLUDING KMFR) LATE THIS AFTERNOON. ANY
STORMS WILL BE CAPABLE OF PRODUCING IFR CIGS/VIS, VERY HEAVY RAIN,
SMALL HAIL, AND GUSTY WINDS. SHOWERS AND STORMS DIMINISH LATE THIS
EVENING. -WRIGHT
&&
.MARINE...UPDATED 500 AM PDT FRI 6 MAY 2016...FEW CHANGES WERE
MADE TO THE MARINE FORECAST THIS MORNING. NORTH WINDS WILL
INCREASE AGAIN THIS AFTERNOON AND CONTINUE INTO THE EVENING. THIS
TREND OF STRONG NORTH WINDS/STEEP SEAS IN THE AFTERNOON/EVENINGS
AND LULLS AT NIGHT WILL LIKELY CONTINUE THROUGH THE WEEKEND. A
GALE WARNING REMAINS IN EFFECT THROUGH THIS EVENING OVER THE
SOUTHERN WATERS WITH SMALL CRAFT ADVISORIES ELSEWHERE. MODELS
HAVE MAINTAINED THE POTENTIAL FOR GALES OVER THE WEEKEND AND GALE
WATCHES REMAIN IN EFFECT. THESE WILL LIKELY BE UPGRADED LATER
TODAY. -WRIGHT
&&
.PREV DISCUSSION... /ISSUED 339 AM PDT FRI MAY 6 2016/
DISCUSSION...A MOIST AND UNSTABLE AIR MASS CONTINUES OVER MUCH OF
THE FORECAST AREA TODAY...AND WILL HELP GENERATE ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS...PRIMARILY FOCUSED OVER NORTHERN
CALIFORNIA AND FROM THE CASCADES EASTWARD. THE CUTOFF LOW THAT
DOESN`T QUIT REMAINS OVER SOUTHERN CALIFORNIA...SLOWLY MOVING TO
THE EAST AND FEEDING THE AREA WITH DEEP MOISTURE AND DISTURBANCES
FROM THE SOUTHEAST.
THE INTERSECTION OF DEEP MOISTURE...INSTABILITY...AND FAVORABLE
DYNAMICS WILL BE MOST PROMINENT IN EASTERN
SISKIYOU...MODOC...AND LAKE COUNTIES TODAY. THE WRF ARW AND NMM
SHOW STORMS AND HEAVY RAINFALL FROM MOUNT SHASTA EASTWARD TO
ALTURAS AND NORTHEAST TO LAKEVIEW THIS AFTERNOON AND EVENING AS
SHORTWAVE ENERGY MOVES IN FROM THE EAST PER THE NAM AND SREF MODEL
OUTPUT. THE LATEST HRRR OUTPUT IS SUGGESTING SIMILAR. GIVEN
CURRENT SNOW DEPTH OVER THE WARNER MOUNTAINS OF 62 INCHES PER
DISMAL SWAMP SNOTEL...AND FORECAST SNOW LEVELS OF 9500 FEET...THIS
DEFINITELY PROVIDES THE POTENTIAL FOR RAPID SNOW MELT AND FLASH
FLOODING. A FLASH FLOOD WATCH CONTINUES FOR THE SOUTHERN HALF OF
SISKIYOU COUNTY...MODOC...EXTREME EASTERN KLAMATH...AND MOST OF
LAKE COUNTY. PRECIPITABLE WATER VALUES IN THE TOP 10 PERCENT FOR
THIS TIME OF YEAR ALSO SUPPORT THE FFA AREA. THE WESTERN FRINGES
OF THIS HAZARD AREA ARE LESS LIKELY TO SEE ANY HEAVY RAIN PROBLEMS
BUT HAVE LEFT THE AREA INTACT FROM THE PREVIOUS ISSUANCE GIVEN THE
UNCERTAINTY OF EXACT HEAVY RAIN LOCATIONS...AND WITH LATEST HRRR
OUTPUT LINING UP PRETTY NICELY WITH THE HAZARD AREA.
ADDITIONALLY...THE STORM PREDICTION CENTER HAS MAINTAINED A MARGINAL
RISK FOR SEVERE STORMS OVER MODOC AND SOUTHERN LAKE COUNTIES.
EASTERN SISKIYOU COUNTY ALSO FEATURES A CHANCE FOR SEVERE
THUNDERSTORMS WITH FORECAST MOST UNSTABLE CAPES OF 2000+ J/KG, LI
VALUES -4 TO -6, AND 0-6KM BULK SHEAR VALUES OF 30+KT. STRONG
WINDS, HAIL, AND HEAVY RAIN ARE ALL A POSSIBILITY TODAY. LATEST
SATELLITE IMAGERY SHOWS THAT THE DAY SHOULD START OUT SUNNY IN MANY
PLACES EAST OF THE CASCADES...WHICH WILL YIELD UNINHIBITED SURFACE
HEATING AND POTENTIALLY MAX OUT THE INSTABILITY THIS AFTERNOON.
INSTABILITY DIMINISHES TONIGHT AND SHOWERS AND THUNDERSTORMS FOLLOW
SUIT. ON SATURDAY A DRYING AIR MASS WEST OF THE CASCADES WILL YIELD
SUNNY AND WARM CONDITIONS WHILE THUNDERSTORMS REMAIN POSSIBLE IN
MODOC COUNTY. TEMPERATURES WILL BE ABOUT 10 DEGREES ABOVE NORMAL
WEST OF THE CASCADES. BY SUNDAY COOL AND DRY NORTHWEST FLOW ALOFT
ELIMINATES THE CHANCE FOR SHOWERS OVER THE VAST MAJORITY OF THE
FORECAST AREA...WHILE A DEEPENING MARINE LAYER COULD BRING DRIZZLE
TO THE COAST.
ON MONDAY A WARM TREND BEGINS THAT WILL LAST INTO THE MIDDLE OF THE
WEEK AT LEAST...WITH TEMPERATURES MONDAY EXPECTED TO BE A FEW
DEGREES ABOVE NORMAL. A PORTION OF THE PREVIOUS LONG-TERM
DISCUSSION FOLLOWS.
TUESDAY THROUGH THURSDAY...AN UPPER RIDGE WILL BUILD OFF THE
COAST TUESDAY WITH A THERMAL TROUGH DEVELOPING AT THE COAST. THE
MODELS DIFFER WITH THE DETAILS AFTER TUESDAY, BUT THE PATTERN
REMAINS FAVORABLE FOR CONTINUED DRY AND WARM CONDITIONS.
-PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FLASH FLOOD WATCH THROUGH THIS EVENING FOR ORZ030-031.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR ORZ022.
CA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CAZ080>085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS
EVENING FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR PZZ350-356-370.
GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ356-376.
GALE WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING FOR
PZZ376.
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
339 AM PDT FRI MAY 6 2016
.DISCUSSION...A MOIST AND UNSTABLE AIR MASS CONTINUES OVER MUCH OF
THE FORECAST AREA TODAY...AND WILL HELP GENERATE ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS...PRIMARILY FOCUSED OVER NORTHERN
CALIFORNIA AND FROM THE CASCADES EASTWARD. THE CUTOFF LOW THAT
DOESN`T QUIT REMAINS OVER SOUTHERN CALIFORNIA...SLOWLY MOVING TO
THE EAST AND FEEDING THE AREA WITH DEEP MOISTURE AND DISTURBANCES
FROM THE SOUTHEAST.
THE INTERSECTION OF DEEP MOISTURE...INSTABILITY...AND FAVORABLE DYNAMICS
WILL BE MOST PROMINENT IN EASTERN SISKIYOU...MODOC...AND LAKE
COUNTIES TODAY. THE WRF ARW AND NMM SHOW STORMS AND HEAVY RAINFALL
FROM MOUNT SHASTA EASTWARD TO ALTURAS AND NORTHEAST TO LAKEVIEW
THIS AFTERNOON AND EVENING AS SHORTWAVE ENERGY MOVES IN FROM THE
EAST PER THE NAM AND SREF MODEL OUTPUT. THE LATEST HRRR OUTPUT IS
SUGGESTING SIMILAR. GIVEN CURRENT SNOW DEPTH OVER THE WARNER
MOUNTAINS OF 62 INCHES PER DISMAL SWAMP SNOTEL...AND FORECAST SNOW
LEVELS OF 9500 FEET...THIS DEFINITELY PROVIDES THE POTENTIAL FOR
RAPID SNOW MELT AND FLASH FLOODING. A FLASH FLOOD WATCH CONTINUES
FOR THE SOUTHERN HALF OF SISKIYOU COUNTY...MODOC...EXTREME EASTERN
KLAMATH...AND MOST OF LAKE COUNTY. PRECIPITABLE WATER VALUES IN
THE TOP 10 PERCENT FOR THIS TIME OF YEAR ALSO SUPPORT THE FFA
AREA. THE WESTERN FRINGES OF THIS HAZARD AREA ARE LESS LIKELY TO
SEE ANY HEAVY RAIN PROBLEMS BUT HAVE LEFT THE AREA INTACT FROM THE
PREVIOUS ISSUANCE GIVEN THE UNCERTAINTY OF EXACT HEAVY RAIN
LOCATIONS...AND WITH LATEST HRRR OUTPUT LINING UP PRETTY NICELY
WITH THE HAZARD AREA.
ADDITIONALLY...THE STORM PREDICTION CENTER HAS MAINTAINED A MARGINAL
RISK FOR SEVERE STORMS OVER MODOC AND SOUTHERN LAKE COUNTIES.
EASTERN SISKIYOU COUNTY ALSO FEATURES A CHANCE FOR SEVERE
THUNDERSTORMS WITH FORECAST MOST UNSTABLE CAPES OF 2000+ J/KG, LI
VALUES -4 TO -6, AND 0-6KM BULK SHEAR VALUES OF 30+KT. STRONG
WINDS, HAIL, AND HEAVY RAIN ARE ALL A POSSIBILITY TODAY. LATEST
SATELLITE IMAGERY SHOWS THAT THE DAY SHOULD START OUT SUNNY IN MANY
PLACES EAST OF THE CASCADES...WHICH WILL YIELD UNINHIBITED SURFACE
HEATING AND POTENTIALLY MAX OUT THE INSTABILITY THIS AFTERNOON.
INSTABILITY DIMINISHES TONIGHT AND SHOWERS AND THUNDERSTORMS FOLLOW
SUIT. ON SATURDAY A DRYING AIR MASS WEST OF THE CASCADES WILL YIELD
SUNNY AND WARM CONDITIONS WHILE THUNDERSTORMS REMAIN POSSIBLE IN
MODOC COUNTY. TEMPERATURES WILL BE ABOUT 10 DEGREES ABOVE NORMAL
WEST OF THE CASCADES. BY SUNDAY COOL AND DRY NORTHWEST FLOW ALOFT
ELIMINATES THE CHANCE FOR SHOWERS OVER THE VAST MAJORITY OF THE
FORECAST AREA...WHILE A DEEPENING MARINE LAYER COULD BRING DRIZZLE
TO THE COAST.
ON MONDAY A WARM TREND BEGINS THAT WILL LAST INTO THE MIDDLE OF THE
WEEK AT LEAST...WITH TEMPERATURES MONDAY EXPECTED TO BE A FEW
DEGREES ABOVE NORMAL. A PORTION OF THE PREVIOUS LONG-TERM
DISCUSSION FOLLOWS.
TUESDAY THROUGH THURSDAY...AN UPPER RIDGE WILL BUILD OFF THE
COAST TUESDAY WITH A THERMAL TROUGH DEVELOPING AT THE COAST. THE
MODELS DIFFER WITH THE DETAILS AFTER TUESDAY, BUT THE PATTERN
REMAINS FAVORABLE FOR CONTINUED DRY AND WARM CONDITIONS.
-PETRUCELLI
&&
.AVIATION...FOR THE 06/06Z TAF CYCLE...THE MAIN CONCERN THROUGH
THIS EVENING WILL BE THUNDERSTORMS. THUNDERSTORMS ARE LIKELY TO
BE SCATTERED TO NUMEROUS AND MORE LIKELY TO BE STRONG THIS
AFTERNOON AND EVENING. THESE THUNDERSTORMS WILL BE SLOW MOVING AND
PRODUCE MODERATE TO HEAVY RAIN AND THEY MAY PRODUCE GUSTY OUTFLOW
WINDS, AND HAIL. THE BEST CHANCE THIS EVENING WILL BE OVER THE
SOUTHERN OREGON CASCADE FOOTHILLS...CASCADES AND WESTERN AND
CENTRAL SISKIYOU COUNTY WITH A SECONDARY FOCUS OVER MODOC AND LAKE
COUNTIES. THUNDERSTORMS TODAY ARE EXPECTED TO BE MOST NUMEROUS
EAST OF THE CASCADES ALTHOUGH ISOLATED STORMS MAY DEVELOP IN
SOUTHWEST OREGON AND WESTERN SISKIYOU COUNTY.
THERE WILL BE A MIX OF MVFR AND VFR CIGS THIS MORNING WITH AREAS
OF MOUNTAIN OBSCURATIONS. CONDITIONS WILL IMPROVE TO WIDESPREAD
VFR DURING LATE THIS MORNING BUT SHOWERS AND THUNDERSTORMS
DEVELOPING LATE MORNING THROUGH THE EVENING WILL ONCE AGAIN CREATE
AREAS OF MVFR WITH POTENTIALLY HAZARDOUS CONDITIONS. -DW/CC
&&
.MARINE...UPDATED 830 PM PDT THU 5 MAY 2016...OFFSHORE HIGH
PRESSURE AND INLAND LOW PRESSURE WILL PRODUCE PERSISTENT GUSTY
NORTHERLY WINDS AND STEEP TO VERY STEEP SEAS THROUGH THIS EVENING.
THE STRONGEST WINDS AND HIGHEST SEAS WILL OCCUR OVER THE OUTER
WATERS SOUTH OF CAPE BLANCO. WINDS AND SEAS WILL REACH A PEAK THIS
AFTERNOON...THEN GUSTY NORTH WINDS WILL CONTINUE AND SEAS ARE
LIKELY TO REMAIN STEEP TO VERY STEEP THROUGH THE WEEKEND. AS A
RESULT...A GALE WATCH HAS BEEN FOR THE OUTER WATERS SOUTH OF CAPE
BLANCO FROM LATE SATURDAY MORNING THROUGH SUNDAY EVENING.
CONFIDENCE IS MODERATE AS THE MAJORITY BUT NOT ALL OF THE MODELS
HAVE TRENDED SLIGHTLY STRONGER WITH WEEKEND WINDS...ESPECIALLY ON
SUNDAY. WINDS AND SEAS WILL BEGIN TO TREND WEAKER ON MONDAY AND
ARE EXPECTED TO DIMINISH INTO WEDNESDAY. -DW/CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FLASH FLOOD WATCH THROUGH THIS EVENING FOR ORZ030-031.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR ORZ022.
CA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CAZ080>085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR PZZ350-356-370.
GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ356-376.
GALE WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING FOR
PZZ376.
$$
NSK/MAP/CC
AREA FORECAST DISCUSSION...UPDATED
NWS CHEYENNE WY
542 AM MDT FRI MAY 6 2016
.UPDATE...FOR THE EARLY MORNING AVIATION FORECAST PACKAGE UPDATE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 401 AM MDT FRI MAY 6 2016
AN EXTREMELY ACTIVE PERIOD OF WEATHER OVER THE NEXT FEW DAYS WITH AT
LEAST SOME POTENTIAL FOR SEVERE THUNDERSTORMS...FLASH FLOODING...AND
ACCUMULATING MOUNTAIN SNOW. MORNING WATER VAPOR AND OBJECTIVE UPPER-
AIR ANALYSIS REVEAL AN IMPRESSIVE OMEGA BLOCK ENCOMPASSING VIRTUALLY
ALL OF THE LOWER 48. HIGH-AMPLITUDE RIDGING OVER THE GREAT PLAINS IS
EXPECTED TO BREAK DOWN OVER THE NEXT 12 HOURS...BUT EXPECT VERY SLOW
PROGRESSION OF THE SOUTHWESTERN US LOW GIVEN THE CURRENT LARGE SCALE
BLOCKING PATTERN IN PLACE.
SOUTHWEST FLOW ALOFT IS ALREADY INCREASING OVER THE CWA THIS AM WITH
DEEP MOISTURE STREAMING NORTHWARD. WE WILL NOT SEE AS MUCH SUN AS WE
HAVE OVER THE LAST FEW DAYS...BUT EXPECT ANOTHER MILD AFTERNOON WITH
MODELS STILL SHOWING H7 TEMPS BETWEEN +8 AND +10 DEG C. IT WILL ALSO
BE A WARM START TO THE DAY WITH CHEYENNE SITTING AT 53 DEGREES AS OF
3 AM MDT. WEAK SURFACE CYCLOGENESIS WILL OCCUR OVER NORTHEASTERN
CO TODAY...RESULTING IN LOW-LEVEL UPSLOPE ALONG AND EAST OF THE
LARAMIE RANGE HEADING INTO THIS AFTERNOON. LOW-LEVEL MOISTURE IS
EXPECTED TO INCREASE WITH DEW POINTS IN THE 40S TO NEAR 50. WARM
TEMPERATURES AT THE SURFACE WILL PROMOTE STEEP LAPSE
RATES...POSSIBLY YIELDING CAPES AROUND 500-1000 J/KG AREAWIDE.
FORECAST SOUNDINGS LOOK FAVORABLE FOR STRONG TO LOCALLY SEVERE
CONVECTION...SO ADDED MENTION OF SMALL HAIL AND GUSTY WINDS FOR
ALL ZONES THIS AFTERNOON. THE 06Z DY1 CONVECTIVE OUTLOOK FROM SPC
HAS MUCH OF THE AREA IN A MARGINAL RISK. A PIECE OF MID-LEVEL VORT
ENERGY IS PROGGED TO ROTATE ACROSS SOUTHEAST WYO LATE
TONIGHT...BETWEEN 00Z AND 12Z SAT. BELIEVE THIS WILL INTERACT WITH
A PRONOUNCED FRONTAL BOUNDARY AND DEEP UPSLOPE FLOW TO PRODUCE AN
AREA OF MODERATE TO HEAVY PRECIPITATION OVER OUR NORTHERN
ZONES...SO WENT AHEAD AND INTRODUCED CATEGORICAL POPS PER
COORDINATION WITH UNR.
BIG CHALLENGES WITH THE FORECAST FOR SATURDAY. MODELS SHOW THE UPPER
LOW CENTERED OVER THE FOUR CORNERS WITH ONE OR MORE SIGNIFICANT VORT
LOBES AFFECTING THE CWA...THE STRONGER OF WHICH APPEARS TO ARRIVE IN
THE LATE AFTERNOON/EVENING. STRONG DYNAMIC SUPPORT IS LIKELY THROUGH
THE DAY WITH CYCLOGENESIS OVER NORTHEAST CO REINFORCING UPSLOPE FLOW
AND UPPER-LEVEL DIVERGENCE IN THE LEFT EXIT REGION OF A 100-110 KNOT
H25 JET OVER SOUTHEAST CO. SEVERE THUNDERSTORMS ARE STARTING TO LOOK
LIKE MORE OF A THREAT...MAINLY IN THE CYS-TOR-SNY TRIANGLE AND AREAS
TO THE SOUTH AND EAST. WOULD LIKE TO SEE THE POSITION OF THE SURFACE
LOW FARTHER NORTHWEST FOR A BIG OUTBREAK...BUT NONETHELESS THIS DOES
SUPPORT MOIST EASTERLY SFC FLOW VEERING TO THE SOUTHEAST AT H7 WHICH
YIELDS SHEAR PROFILES FAVORABLE FOR SUPERCELLS. BOTH THE GFS AND NAM
SHOW 1500-2500 J/KG OF SBCAPE AND EXCELLENT 0-1 KM EHI GIVEN LOW-LVL
SHEAR IN PLACE. SLIGHT RISK FROM SPC NOW INCLUDES I80 BETWEEN SIDNEY
AND CHEYENNE...SO DECIDED TO ADD MENTION OF SEVERE. CIPS ANALOGS ARE
CONSISTENT WITH SEVERAL NORTHEAST COLORADO TORNADO EVENTS...SO WOULD
NOT BE SURPRISED TO SEE AN ISOLATED TORNADO OR TWO NEAR THE COLORADO
BORDER ON SATURDAY.
IN ADDITION TO THE RISK FOR SEVERE THUNDERSTORMS...A MORE WIDESPREAD
THREAT FOR VERY HEAVY RAIN IS EXPECTED. DEEP MOISTURE AND IMPRESSIVE
LARGE SCALE DYNAMICS WILL BE IN PLACE THROUGH THE NIGHT AS THE UPPER
LOW WILL BE SLOW MOVING DUE TO A REX BLOCK. ABSOLUTELY NO DOUBT THAT
THUNDERSTORMS ON SATURDAY/SATURDAY NIGHT WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH PWATS OF 0.5 TO 1.0 INCH BEING WELL ABOVE CLIMO. SOME
CONCERN FOR TRAINING CONVECTION AS WELL. THE PRIMARY ISSUE HERE WILL
LIKELY BE OVER THE HIGHER TERRAIN WITH AN ENHANCED LIKELIHOOD FOR AN
ACCELERATED SNOWMELT AND FLASH FLOODING OF CREEKS/STREAMS. GAVE SOME
CONSIDERATION TO A FLASH FLOOD WATCH...BUT WE DECIDED TO LET THE DAY
SHIFT TAKE ANOTHER LOOK AND SEE IF THEY CAN NARROW DOWN THE SPECIFIC
THREAT AREAS. WPC HAS MUCH OF OUR CWA IN A SLIGHT RISK FOR EXCESSIVE
RAINFALL ON SATURDAY...SO FULLY EXPECT THAT FLOOD AND/OR FLASH FLOOD
WATCHES WILL BE NECESSARY SOON. BY LATE SATURDAY NIGHT...WBZ HEIGHTS
FINALLY DROP BELOW 10K FEET WHICH WOULD SUGGEST MOUNTAIN SNOW. COULD
SEE ADVISORY-LEVEL AMOUNTS IF THE CHANGEOVER OCCURS SOON ENOUGH OVER
THE SNOWY AND SIERRA MADRE RANGES.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 401 AM MDT FRI MAY 6 2016
WET PATTERN CONTINUES INTO SUNDAY AS THE UPPER LOW ESSENTIALLY
STALLS ACROSS SOUTHEAST WYOMING WITH HIGH CHANCE TO LIKELY POPS A
FAIRLY GOOD BET ACROSS THE ENTIRE FORECAST AREA. CONCERNS FOR
FLOOD POTENTIAL WILL CONTINUE INTO SUNDAY GIVEN COVERAGE OF RAIN
BUT COOLER TEMPERATURES SHOULD MEAN MORE SNOW IN THE HIGHER
ELEVATIONS VERSUS RAIN BY LATE IN THE WEEKEND. THE AIRMASS WILL
BE A BIT MORE STABILIZED ON SUNDAY DUE TO COOLER BOUNDARY
LAYER CONDITIONS...HOWEVER WE STILL EXPECT TO SEE THE POTENTIAL
FOR ISOLATED THUNDERSTORMS IN THE AFTERNOON TO EARLY EVENING
HOURS. THE UPPER LOW FINALLY KICKS OUT TO THE NORTHEAST LATE
MONDAY WITH A DOWNWARD TREND IN POPS EXPECTED ACROSS THE SOUTHERN
ZONES TUESDAY WITH CHANCE POPS FOR SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS THE NORTHERN ZONES AHEAD OF THE NEXT
APPROACHING UPPER TROUGH MOVING DOWN FROM MONTANA. THAT TROUGH
MOVES EAST BY THURSDAY WITH SLIGHT CHANCE POPS EXPECTED GOING INTO
LATE WEEK. OVERALL NEXT WEEK LOOKS TO BE COOLER THAN WHAT WE HAVE
SEEN THE LATTER PART OF THIS WEEK WITH DAILY HIGH TEMPS GENERALLY
IN THE 40S-50S WEST AND 60S EAST. ELEVATIONS ABOVE 9500 FT LOOK
TO SEE HIGHS IN THE MID 30S TO AROUND 40 THROUGH THE WEEK...COOL
ENOUGH TO SLOW THE SNOWMELT PROCESS A BIT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 542 AM MDT FRI MAY 6 2016
FOLLOWED TREND AS DEPICTED BY HRRR THIS PACKAGE IN BRINGING
SHOWERS AND ISOLATED THUNDERSTORMS UP INTO SE WYOMING MID TO LATE
AFTERNOON THEN INTO THE NEBRASKA PANHANDLE BY EARLY EVENING.
CEILINGS AND VISIBILITIES PREVAILING VFR THROUGH LATE AFTERNOON
INTO THE EVENING HOURS WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS PASSING ACROSS THE REGION. LOWERED CEILINGS FOR
SCOTTSBLUFF, CHEYENNE, LARAMIE AND RAWLINS DOWN TO MVFR AFTER 06Z
WHERE GREATER COVERAGE OF SHOWERS WILL BE AS DEEPER MOISTURE MOVES
UP FROM THE SOUTH.
&&
.FIRE WEATHER...
ISSUED AT 401 AM MDT FRI MAY 6 2016
COOLER AND WETTER PATTERN STILL PROJECTED TO SET UP ACROSS SE
WYOMING AND THE WESTERN NEBRASKA PANHANDLE THROUGH THE WEEKEND.
PATTERN BECOMES A BIT LESS ACTIVE FOR SHOWERS AND THUNDERSTORMS
BY MID WEEK WITH PROJECTED CONDITIONS EXPECTED TO REMAIN WELL
ABOVE ANY CRITICAL THRESHOLDS FOR FIRE WEATHER CONCERNS IN THE
FORSEEABLE FUTURE.
&&
.HYDROLOGY...
ISSUED AT 401 AM MDT FRI MAY 6 2016
WARM TEMPERATURES WILL CONTINUE TODAY WITH AFTERNOON HIGHS LIKELY IN
THE 50S IN THE HIGH ELEVATIONS OF THE SNOWY/SIERRA MADRE RANGES. MTN
CREEKS AND STREAMS WILL CONTINUE TO SEE NOTABLE RISES IN THE NEXT 24
TO 48 HOURS. WIDESPREAD THUNDERSTORMS COULD PRODUCE HEAVY RAIN TODAY
AND SATURDAY. RAIN ON SNOW COULD YIELD ACCELERATED SNOWMELT AND LEAD
TO FLASH FLOODING...ESPECIALLY OF MOUNTAIN CREEKS/STREAMS. THERE MAY
ALSO BE A THREAT FOR LOCALIZED FLASH FLOODING OVER THE PLAINS. FLASH
FLOOD WATCHES MAY BECOME NECESSARY SOON.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLH
LONG TERM...JG
AVIATION...JG
FIRE WEATHER...JG
HYDROLOGY...CLH
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
910 AM MST FRI MAY 6 2016
.SYNOPSIS...
A LARGE PACIFIC LOW PRESSURE SYSTEM WILL MOVE ACROSS THE DESERT
SOUTHWEST OVER THE NEXT FEW DAYS. THIS SYSTEM WILL BRING A CHANCE
FOR SHOWERS...PLUS POTENTIAL FOR THUNDERSTORMS...ALONG WITH MUCH
COOLER CONDITIONS. BEST CHANCES FOR RAIN WILL BE TODAY INTO EARLY
SATURDAY. THE LOW PRESSURE SYSTEM WILL BEGIN TO MOVE EAST
SUNDAY...FOLLOWED BY DRY AND MUCH WARMER WEATHER NEXT WEEK.
&&
.DISCUSSION...
SEVERAL DIFFERENT SYNOPTIC AND MESOSCALE PROCESSES ONGOING THIS
MORNING PER SATELLITE IMAGERY AND OBJECTIVE ANALYSIS. FIRST OVER
GILA COUNTY...A NARROW CORRIDOR OF ISENTROPIC LIFT AND H7-H8
FRONTOGENTICAL FORCING WAS LIFTING MARGINAL MOISTURE INTO A REGION
OF STEEPER MIDLEVEL LAPSE RATES. SEVERAL ACCAS BANDS WITH EMBEDDED
DEEPER CONVECTIVE ELEMENTS WILL CONTINUE TO STREAM NORTH THIS
MORNING OVER THE MOGOLLON RIM...HOWEVER LARGELY BE A NON-PLAYER
WITHIN THE LOCAL FORECAST FOR THE REMAINDER OF THE DAY.
SECONDLY...A SFC-H8 FRONTAL BOUNDARY WAS EVIDENT THROUGH FAR WESTERN
ARIZONA WITH MODEST +10C H9 DEWPOINTS BEING PULLED NORTH AHEAD OF
THIS FRONT. CONCURRENT WITH THIS MOISTURE ADVECTION...A POCKET OF 0-
3KM MLCAPE ABOVE 100 J/KG (AND TOTAL MUCAPE IN EXCESS OF 500 J/KG)
WAS ANALYZED THROUGH MUCH OF LA PAZ COUNTY. UPSTREAM...A LOBE OF
VORTICITY WAS LIFTING THROUGH THE SAN DIEGO AREA WITH WINDWARD SIDE
SHOWERS BEING WRUNG OUT OVER HIGHER TERRAIN. HOWEVER...THIS LARGER
SCALE SYNOPTIC ASCENT WILL GRADUALLY OVERSPREAD THE AREA OF
INCREASING INSTABILITY THIS AFTERNOON...AND MORE ROBUST CONVECTIVE
DEVELOPMENT IS MOST LIKELY ALONG AND JUST EAST OF THE COLORADO RIVER
VALLEY THROUGH THE DAYLIGHT HOURS. HRRR AND OTHER HIGH RESOLUTION
NMM CORES SEEM TO CAPTURE THIS EVOLUTION BEST...AND HAVE HEDGED MOST
OF THE SHORT TERM FORECAST IN THIS DIRECTION.
&&
.PREVIOUS DISCUSSION...
/524 AM MST FRI MAY 6 2016/
TODAY THROUGH SUNDAY...
THE LOW PRESSURE SYSTEM WHICH BROUGHT THE WINDS AND THE BEGINNING OF
A COOLING TREND IS CENTERED JUST OF SANTA BARBARA EARLY THIS MORNING.
WATER VAPOR IMAGERY SHOWS MULTIPLE VORT LOBES WITHIN THE SYSTEM. AT
THE SURFACE...ONE OF WHICH IS MOVING ASHORE INTO FAR SOUTHERN
CALIFORNIA. A SURFACE LOW REMAINS CENTERED OVER THE MOHAVE DESERT.
MODELS CONTINUE TO DEPICT THE UPPER LOW/UPPER TROUGH TRACKING
EASTWARD TODAY AND SATURDAY THEN BEGIN EXITING SUNDAY. IN THE
PROCESS...THERE WILL BE A SERIES OF VORT LOBES MOVING THROUGH FOR
SOME DYNAMICAL ASCENT AT TIMES PLUS COLDER AIR ALOFT FOR SOME
DESTABILIZATION. THERE MAY ALSO BE SOME ADDED DYNAMICAL ASCENT TODAY
ASSOCIATED WITH THE LEFT EXIT REGION OF THE JET. AS THE SYSTEM TRACKS
EAST WITH TIME THE JET AXIS MOVES FURTHER AWAY.
ONE OF THE AFOREMENTIONED VORT LOBES IS MOVING ASHORE INTO FAR
SOUTHERN CALIFORNIA. THIS FEATURE IS NOT INITIALIZED WELL BY THE
LATEST MODELS. BUT IR IMAGERY SHOWS COLD CLOUD TOPS AND THERE IS EVEN
SOME ISOLATED LIGHTNING BEING DETECTED WITHIN THE ASSOCIATED
CLOUDINESS. THIS FEATURE WILL AFFECT MAINLY WESTERN PORTIONS OF THE
FORECAST AREA TODAY BUT THERE WILL ALSO BE SOME STEEPENING LAPSE
RATES EVERYWHERE AND THUS AN UPRAMPING OF POPS TODAY. HI-RES MODELS
ARE A MIXED BAG AS TO THE ONSET OF SHOWERS OVER SOUTH-CENTRAL ARIZONA
TODAY. SOME OF THEM INDICATE A BAND OF SHOWERS DEVELOPING THIS
MORNING...POSSIBLY DUE TO THE SURFACE TROUGH AND ASSOCIATED LOWER
LEVEL CONVERGENCE. THERE IS ALSO SOME UPPER LEVEL
DIFLUENCE/DIVERGENCE THERE AS WELL.
THE MAIN THEME OF THE MODELS IN TERMS OF PRECIP POTENTIAL IS THAT
CHANCES INCREASE FROM WEST TO EAST AS THE DAY WEARS ON AND PEAKS
EAST OF THE LOWER COLORADO RIVER VALLEY TONIGHT AS A VORT LOBE MOVES
THROUGH. POPS TREND DOWN DOWN SATURDAY BEHIND THE EXITING LOBE BUT
DONT GO AWAY ENTIRELY DUE TO LINGERING MOISTURE AND ANOTHER VORT
LOBE...THOUGH THAT ONE TRACKS MOSTLY SOUTH. YET ANOTHER ONE COMES
THROUGH SUNDAY BUT ON THE BACK SIDE OF THE LOW AS THE SYSTEM IS
SHIFTING NORTHEASTWARD. PEAK PRECIPITABLE WATER VALUES ARE NEAR 1
INCH AT THE COAST BUT WITH RAIN SHADOWING WE WILL SEE LESS AND THUS
NOT LOOKING FOR A BIG PRECIP EVENT...BUT CONSIDERING WE ARE GETTING
INTO THE VERY DRIEST TIME OF YEAR...IT WILL BE NOTABLE. THERE WILL
ALSO BE A THREAT OF THUNDERSTORMS. WHILE CAPE IS LOOKING
MODEST...JUST ENOUGH TO UPGRADE MENTION TO CHANCE IN SOME
AREAS...SLIGHT CHANCE ELSEWHERE.
AS FOR TEMPS...CONTINUED COLD AIR ADVECTION WILL MAKE FOR MUCH COOLER
CONDITIONS TODAY OVER SOUTH-CENTRAL ARIZONA...AS MUCH AS 20
DEGREES. THERE WILL BE LESS COOLING FURTHER WEST BECAUSE OF ALREADY
HAVING COOLED INTO THE 80S YESTERDAY. THUS...HIGHS ON THE LOW DESERTS
WILL BE IN THE 70S FRIDAY AND SATURDAY THEN WARMING AT LEAST A FEW
DEGREES ON SUNDAY.
MONDAY THROUGH THURSDAY...
PACIFIC RIDGING SLOWLY BUILDS INTO THE WESTERN STATES DURING THE NEXT
WORKWEEK FOR A WARMING TREND. EXPECT DESERTS TO FLIRT WITH 100 AGAIN
BY THURSDAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
FLOW WILL VEER THROUGHOUT THE DAY AHEAD OF A LOW PRESSURE SYSTEM.
HOWEVER...A PERIOD OF 10-15 KT CROSS-WINDS IS LIKELY THIS MORNING AT
KPHX. BREEZY SOUTHWESTERLY WINDS ARE ALSO ANTICIPATED THIS
AFTERNOON...THOUGH THEY WILL BE WEAKER THAN THOSE OBSERVED THURSDAY
WITH GUSTS GENERALLY AROUND 25 KT. SCATTERED SHOWERS ARE EXPECTED TO
MOVE INTO THE PHOENIX AREA THIS EVENING...BEFORE DISSIPATING BEFORE
MIDNIGHT. OTHERWISE...CLOUD BASES WILL GENERALLY HOVER BETWEEN 5K
AND 8K FT...PERHAPS BECOMING BKN TOWARDS SATURDAY MORNING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
BREEZY SOUTH AND SOUTHWESTERLY FLOW WILL PERSIST AHEAD OF A PACIFIC
LOW PRESSURE SYSTEM. SCATTERED SHOWERS ARE ALSO EXPECTED TO DEVELOP
LATER THIS MORNING AND EARLY THIS AFTERNOON AT KIPL/KBLH. A BRIEF
THUNDERSTORM IS ALSO POSSIBLE...THOUGH THE POTENTIAL FOR HAZARDS
SUCH AS GUSTY WINDS AND BLOWING DUST IS LOW. IMPROVING CONDITIONS
ARE LIKELY BY 02Z SATURDAY AS THE ACTIVITY SHIFTS TO THE EAST.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
THE SLOW-MOVING WEATHER SYSTEM WILL WEAKEN AND MOVE NORTHEASTWARD
OUT OF THE REGION SUNDAY. NEVERTHELESS...A FEW SHOWERS WILL BE
POSSIBLE SUNDAY...MAINLY NORTH AND EAST OF PHOENIX. THEREAFTER...A
WARMING AND DRYING TREND WILL TAKE PLACE AS HIGH PRESSURE RETURNS TO
THE DESERT SOUTHWEST. ABOVE NORMAL TEMPERATURES ARE LIKELY BY
TUESDAY OR WEDNESDAY...PERHAPS REACHING THE 100 DEGREE MARK AGAIN IN
THE LOWER DESERTS. DESPITE THE LOW RHS...FIRE DANGER WILL GENERALLY
REMAIN LOW THROUGH THE WEEK WITH LIGHT WINDS AND RELATIVELY MOIST
FUELS.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/AJ
AVIATION...HIRSCH
FIRE WEATHER...HIRSCH
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
155 PM PDT FRI MAY 6 2016
.SYNOPSIS...A BROAD UPPER LEVEL LOW NOW CENTERED JUST OFF OF THE
SOUTHERN CALIFORNIA COAST WILL SHIFT SLOWLY EASTWARD AND INLAND
TODAY. BANDS OF MOISTURE ROTATING AROUND IT WILL MAINTAIN SHOWER
CHANCES OVER OUR DISTRICT THROUGH SATURDAY EVENING. THUNDERSTORMS
WILL CONTINUE TO BE POSSIBLE AS WELL...PRIMARILY MORE INLAND
AREAS. PRECIP CHANCES WILL DIMINISH SATURDAY NIGHT AND SUNDAY
MORNING...WITH DRY CONDITIONS THEN EXPECTED TO PREVAIL THROUGH THE
REMAINDER OF THE FORECAST PERIOD. A GRADUAL WARMING TREND IS
EXPECTED FOR THE FIRST HALF OF NEXT WEEK AS A RIDGE OF UPPER LEVEL
HIGH PRESSURE BUILDS OVER THE WEST COAST.
&&
.DISCUSSION...AS OF 2:00 PM PDT FRIDAY...MOISTURE ROTATING AROUND
AN AREA OF LOW PRESSURE OVER SOUTHERN CALIFORNIA IS CURRENTLY
MOVING THROUGH OUR CWA. WORTH NOTING THAT THE RUNS OF THE HRRR
EARLIER THIS MORNING SO FAR HAVE DONE A GOOD JOB WITH BRINGING
THE MOISTURE INTO OUR CWA FROM STO`S. AMOUNTS HAVE BEEN FAIRLY
LIGHT SO FAR WITH MANY PLACES UNDER 1/4". RAIN WILL CONTINUE TO
TRACK TO THE SOUTH INTO MONTEREY AND SAN BENITO COUNTIES. COULD
ALSO SEE A FEW THUNDERSTORMS. IN FACT, ONE CELL FIRED UP OVER FAR
SOUTHERN SAN BENTIO COUNTY THIS AFTERNOON.
A SECOND ROUND OF RAIN IS FORECAST FOR TOMORROW AS ANOTHER SLUG OF
MOISTURE ROTATES AROUND THE LOW. MODELS SHOW SIMILAR VALUES AND
FAIRLY CLOSE TIMING FOR TOMORROW COMPARED TO TODAY WITH ANOTHER
ROUND OF UP TO 1/4" FOR MOST URBAN SPOTS. INSTABILITY DOES NOT
LOOK AS FAVORABLE FOR THUNDERSTORMS COMPARED TO TODAY, HOWEVER AN
ISOLATED CELL OR TWO FOR PARTS WELL INLAND CANNOT BE RULED OUT.
SHOWERS WILL COME TO AN END SATURDAY NIGHT AS THE LOW TRACKS INTO
THE FOUR CORNER`S REGION. A RIDGE OF HIGH PRESSURE WILL THEN
REBUILD TO THE WEST COAST THROUGH NEXT WEEK. THIS WILL HELP TO
PUSH TEMPS BACK TO NORMAL TO ABOVE LEVELS. BY THE MIDDLE OF NEXT
WEEK MOST HIGHS WILL BE IN THE 70S TO THE MID 80S.
NO REAL SIGNS OF ORGANIZED PRECIPITATION FOR ALL OF NEXT WEEK.
&&
.AVIATION...AS OF 10:55 AM PDT FRIDAY...FOR 18Z TAFS. UPPER LOW IN
VICINITY BRINGING GENERALLY UNSETTLED WEATHER TO THE REGION. WRAP
AROUND RAIN SHOWERS WILL MOVE THROUGH THE REGION TODAY AND INTO
SATURDAY BRINGING PERIODS OF -SHRA AND MVFR CIGS. SKIES WILL BE
CHAOTIC WITH FRACTURED DECKS AT VARYING FLIGHT LEVELS FROM 800 FT
TO 11000 FT. THUS VFR TO IFR CIGS WILL BE POSSIBLE... WITH MOSTLY
VFR/MVFR CIGS TO BE EXPECTED. OVERALL LOW CONFIDENCE. WINDS
GENERALLY 15 KT OR LESS.
VICINITY OF KSFO... INTERMITTENT MVFR/VFR OSCILLATING CIGS THRU
THE DAY WITH VCSH/-SHRA FROM WRAP AROUND SHOWERS. ONSHORE WINDS UP
TO 15KT DURING THE AFTERNOON.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY TERMINALS...INTERMITTENT MVFR/VFR OSCILLATING CIGS
THRU DAY WITH VCSH/-SHRA FROM WRAP AROUND SHOWERS. ONSHORE WINDS
UP TO 12 KT DURING AFTERNOON. WINDS NEAR KSNS GUSTING TO AROUND
20 KT AFTER 14Z SAT.
&&
.MARINE...AS OF 10:47 AM PDT FRIDAY...A LOW PRESSURE STORM SYSTEM
WILL SHIFT FARTHER INLAND TODAY BUT CONTINUE TO SPREAD RAIN
SHOWERS OVER THE COASTAL WATERS. WINDS WILL BE SPLIT... WITH
BREEZY NORTHERLY WINDS ACROSS THE NORTHERN OUTER WATERS AND LIGHT
SOUTHERLY WINDS ALONG MUCH OF THE COAST AND THE SOUTHERN WATERS.
SEAS WILL CONTINUE TO BE LIGHT THROUGH SATURDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
&&
$$
PUBLIC FORECAST: BELL/BLIER
AVIATION: DRP
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
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WWW.TWITTER.COM/NWSBAYAREA
[top]
Area Forecast Discussion
National Weather Service Sacramento CA
153 PM PDT FRI MAY 6 2016
.SHORT TERM DISCUSSION...
.Synopsis...
Another day of showers Saturday then a drying trend with only a
slight chance of showers Sunday. Temperatures warming into 90s
next week.
.Short Term Discussion...
Clouds keeping instability down today and not nearly as much
convection going today as yesterday. Biggest challenge is trying
to figure out timing of the next wave of moisture. Both the
GFS/NAM in pretty good agreement that this wave will rotate down
into Sacramento area tonight after midnight. HRRR however
suggesting it will come sooner, either way, should be another
round of rain pushing across tonight and probably into Saturday
morning. After the morning rain, instability not nearly as high
Saturday afternoon, but enough around that there should be a few
showers.
Sunday...overall the energy from this weather system is shifting
away from the area. Have kept a slight chance of showers in the
valley and slightly higher in higher terrain, but overall a drier
and warmer day. This drying and warming trend continues into
Monday. Rasch
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)
Warmer and dry pattern ahead for Northern California.
A weak system is projected to clip the area on Tuesday, but this
will bring only light showers to portions of the Sierra and
southern Cascades. Upper ridge moves in late Tuesday and persists
through extended period. High temperatures under ridge will be in the
mid to upper 80s with some locations in the northern portions of
Valley like Redding and Red Bluff reaching low 90s.
Just beyond the extended period, models hint at ridge breaking
down with trough moving in during the weekend. Models disagree
this far in advance with how far south the trough digs and how
quickly it moves through, which isn`t surprising. Either way, it
could mean another chance of precip in the long term.
Owen
&&
.AVIATION...
Upr low ovr SoCal with Ely flow alf ovr fcst area bcmg NEly tngt and
Sat as low movs into Grt Basin. VFR conds ovr Intr NorCal nxt 24
hrs exc lcl MVFR poss in shwrs or tstms...mnly ovr fthls/mtns.
SFC wnds genly blo 15 kts thru Sat exc gsty nr tstms.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1053 AM PDT FRI MAY 6 2016
.SYNOPSIS...A BROAD UPPER LEVEL LOW NOW CENTERED JUST OFF OF THE
SOUTHERN CALIFORNIA COAST WILL SHIFT SLOWLY EASTWARD AND INLAND
TODAY. BANDS OF MOISTURE ROTATING AROUND IT WILL MAINTAIN SHOWER
CHANCES OVER OUR DISTRICT THROUGH SATURDAY EVENING. THUNDERSTORMS
WILL CONTINUE TO BE POSSIBLE AS WELL...PRIMARILY MORE INLAND
AREAS. PRECIP CHANCES WILL DIMINISH SATURDAY NIGHT AND SUNDAY
MORNING...WITH DRY CONDITIONS THEN EXPECTED TO PREVAIL THROUGH THE
REMAINDER OF THE FORECAST PERIOD. A GRADUAL WARMING TREND IS
EXPECTED FOR THE FIRST HALF OF NEXT WEEK AS A RIDGE OF UPPER LEVEL
HIGH PRESSURE BUILDS OVER THE WEST COAST.
&&
.DISCUSSION...AS OF 9:00 AM PDT FRIDAY...SHOWERS EXPECTED TO
RETURN TO OUR REGION SHORTLY. IN FACT HRRR IS FAIRLY BULLISH AND
BRINGS AN AREA OF MOISTURE (WELL DEPICTED BY RADARS) TO MOST OF
THE SF BAY REGION DOWN TO SANTA CRUZ AND SANTA CLARA COUNTY BY
EARLY IN THE AFTERNOON. AFTER THAT SHOWERS CAN BE EXPECTED WITH
ANOTHER ROUND OF RAIN FORECAST FOR TOMORROW. DID A MINOR UPDATE
THIS MORNING TO THE FORECAST AND UPPED THE POPS FOR SATURDAY IN
LIGHT OF LATEST GUIDANCE. ALSO ADDED A SLIGHT CHANCED FOR
THUNDERSTORMS TO EASTERN PARTS OF THE CWA. RAINFALL AMOUNTS STILL
FORECAST TO BE FAIRLY LIGHT WITH UNDER 1/4" IN MOST URBAN SPOTS.
LOCAL RANGES COULD SEE UP TO 2/3".
WILL UPDATE FORECAST TODAY AS NECESSARY BASED ON THE TRACK OF THE
RAIN.
.PREVIOUS DISCUSSION...LATEST KMUX RADAR DATA
AND SURFACE OBS INDICATE DRY CONDITIONS NOW PREVAILING ACROSS
MOST OF OUR DISTRICT...THOUGH WITH SOME SHOWERS HAVING JUST DEVELOPED
OVER THE SOUTHERN SANTA LUCIA MTNS OF MONTEREY COUNTY. WATER
VAPOR SATELLITE IMAGERY AND MODEL ANALYSIS SHOW A BROAD AND
DIFFUSE UPPER LEVEL LOW NEAR THE SOUTHERN CALIFORNIA COAST...WITH
ITS CENTER PRESENTLY IN THE VICINITY OF THE NORTHERN CHANNEL
ISLANDS. THE SYNOPTIC SCALE WEATHER SITUATION FOR OUR AREA IS AN
UNUSUAL ONE...WITH THE FLOW ALOFT ADVECTING IN A MOIST AND
POTENTIALLY UNSTABLE AIR MASS FROM THE EAST. THE NEXT BAND OF CLOUDINESS
IS SPREADING RAPIDLY WESTWARD INTO THE SF BAY AREA THROUGH THE
MIDDLE OF THE CENTRAL VALLEY. THUS FAR HOWEVER...ASSOCIATED
PRECIP HAS LARGELY BEEN CONFINED TO THE HIGHER ELEVATIONS OF THE
SIERRA NEVADA WITH NEITHER KDAX NOR KMUX RADARS...OR SURFACE
OBS...INDICATING ANY APPRECIABLE ASSOCIATED SHOWER ACTIVITY
PRESENTLY MOVING TOWARDS US. AS A RESULT EXPECT THE DAY TO GET OFF
TO A DRY START...AT LEAST THROUGH THE MORNING COMMUTE.
THEREAFTER THOUGH CONFIDENCE DIMINISHES. MODEL PERFORMANCE IN
GENERAL WITH THIS SYSTEM THUS FAR...IN TERMS OF TIMING AND
LOCATION OF ASSOCIATED PRECIPITATION...HAS NOT BEEN PARTICULARLY
IMPRESSIVE. AND EVEN IN THE SHORT TERM...WIDE VARIATION BETWEEN
MODEL SOLUTIONS IN THIS RESPECT CONTINUES TO BE EVIDENT. THE NEW
06Z RUN OF THE GFS SHOWS PRECIP THIS AFTERNOON PRIMARILY CONFINED
TO SANTA CLARA AND SAN BENITO COUNTIES...WHILE THE 06Z NAM SPREADS
IT OVER ALMOST ALL OF OUR DISTRICT ASIDE FROM SONOMA COUNTY...THE
LATEST (09Z) HRRR RUN STARTS THE SHOWER ACTIVITY IN THE LATE
MORNING OVER THE NORTH BAY WITH IT THEN DIMINISHING AS IT MOVES
SOUTHWARD THROUGH THE CENTRAL SF BAY AREA DURING THE
AFTERNOON...AND THE LATEST AVAILABLE (00Z) OUTPUT FROM THE ECMWF
MODEL FOCUSES IT ON THE FAR SE PORTION OF OUR CWA DURING THE
AFTERNOON. AS A RESULT...VERY DIFFICULT TO NAIL DOWN DETAILS IN
GRIDS AND FORECAST.
THAT SAID HOWEVER...THERE IS MUCH BETTER AGREEMENT REGARDING THE
GENERAL LARGER-SCALE PICTURE AND EVOLUTION. GOOD CONSENSUS THAT
THE UPPER LEVEL LOW WILL TRACK GRADUALLY EASTWARD THROUGH FAR
SOUTHERN CALIFORNIA AND INTO ARIZONA BY SUNDAY MORNING. BY THAT
POINT ALL ASSOCIATED PRECIP SHOULD HAVE SHIFTED EASTWARD OF OUR
DISTRICT...BUT UNTIL THEN SHOWER CHANCES WILL CONTINUE.
THUNDERSTORMS WILL ALSO REMAIN POSSIBLE THROUGH THIS
EVENING...PRIMARILY OVER THE MOUNTAINS AND MORE INLAND AREAS...AND
THEN SHOULD DIMINISH AND COME TO AN END AS THE AIR MASS
STABILIZES.
FROM SUNDAY AFTERNOON THROUGH AT LEAST THE MIDDLE OF NEXT
WEEK...DRY CONDITIONS AND A WARMING TREND ARE EXPECTED TO PREVAIL
WITH GOOD LONGER RANGE MODEL AGREEMENT THAT AN UPPER LEVEL RIDGE
WILL BUILD IN OVER THE WEST COAST. BOTH THE ECMWF AND GFS
SIGNIFICANTLY RAISE 850 MB TEMPS AS THIS OCCURS...UP INTO THE 15C
TO 17C RANGE BY WEDNESDAY AND THURSDAY WITH AFTERNOON HIGHS...AT
LEAST INLAND AREAS...THEN PROJECTED TO REACH UP INTO THE 80S.
&&
.AVIATION...AS OF 10:55 AM PDT FRIDAY...FOR 18Z TAFS. UPPER LOW IN
VICINITY BRINGING GENERALLY UNSETTLED WEATHER TO THE REGION. WRAP
AROUND RAIN SHOWERS WILL MOVE THROUGH THE REGION TODAY AND INTO
SATURDAY BRINGING PERIODS OF -SHRA AND MVFR CIGS. SKIES WILL BE
CHAOTIC WITH FRACTURED DECKS AT VARYING FLIGHT LEVELS FROM 800 FT
TO 11000 FT. THUS VFR TO IFR CIGS WILL BE POSSIBLE... WITH MOSTLY
VFR/MVFR CIGS TO BE EXPECTED. OVERALL LOW CONFIDENCE. WINDS
GENERALLY 15 KT OR LESS.
VICINITY OF KSFO... INTERMITTENT MVFR/VFR OSCILLATING CIGS THRU
THE DAY WITH VCSH/-SHRA FROM WRAP AROUND SHOWERS. ONSHORE WINDS UP
TO 15KT DURING THE AFTERNOON.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY TERMINALS...INTERMITTENT MVFR/VFR OSCILLATING CIGS
THRU DAY WITH VCSH/-SHRA FROM WRAP AROUND SHOWERS. ONSHORE WINDS
UP TO 12 KT DURING AFTERNOON. WINDS NEAR KSNS GUSTING TO AROUND
20 KT AFTER 14Z SAT.
&&
.MARINE...AS OF 10:47 AM PDT FRIDAY...A LOW PRESSURE STORM SYSTEM
WILL SHIFT FARTHER INLAND TODAY BUT CONTINUE TO SPREAD RAIN
SHOWERS OVER THE COASTAL WATERS. WINDS WILL BE SPLIT... WITH
BREEZY NORTHERLY WINDS ACROSS THE NORTHERN OUTER WATERS AND LIGHT
SOUTHERLY WINDS ALONG MUCH OF THE COAST AND THE SOUTHERN WATERS.
SEAS WILL CONTINUE TO BE LIGHT THROUGH SATURDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM
&&
$$
PUBLIC FORECAST: BELL/BLIER
AVIATION: DRP
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1053 AM MDT FRI MAY 6 2016
.UPDATE...
ISSUED AT 1053 AM MDT FRI MAY 6 2016
MADE SOME SLIGHT CHANGES TO THE COVERAGE OF SHOWERS THIS AFTERNOON
OER THE MOUNTAINS...FOOTHILLS AND ADJACENT PLAINS BASED ON THE
FORECASTS OF THE PAST SEVERAL RUNS OF THE RAP MODEL. MOST OF THE
SHOWER ACTIVITY IS EXPECTED TO BE OVER THE MOUNTAINS AND
FOOTHILLS...BUT A FEW STORMS MAY ALSO DEVELOP OVER THE I-25 URBAN
CORRIDOR. GUSTY WINDS ARE GOING TO BE THE MAIN THREAT FROM THE
STORMS THAT DEVELOP THIS AFTERNOON...ALTHOUGH MOUNTAIN AREAS COULD
PICK UP A LITTLE RAIN AND SMALL HAIL TOO. THE PRIMARY BAND OF
SHOWERS IS MOVING NORTHWARD OVER PARK COUNTY AT THE PRESENT TIME.
ADDITIONAL SHOWER DEVELOPMENT AFTER PASSAGE OF THE FIRST BAND OF
SHOWERS WILL BE LIMITED DUE TO THE WEAK SUBSIDENCE TRAILING THE
SHORT WAVE THAT IS DRIVING THE SHOWER DEVELOPMENT. HOWEVER...
THERE COULD BE ENOUGH AFTERNOON HEATING OVER THE MOUNTAINS FOR A
FEW WEAK SHOWERS TO DEVELOP. IT LOOKS LIKE SHOWER ACTIVITY ACROSS
THE EASTERN PLAINS IS GOING TO BE QUITE LIMITED EXCEPT NEAR THE
WYOMING BORDER LATER TONIGHT. THIS WILL ALLOW FOR THE TEMPERATURES
TO CLIMB NICELY INTO THE UPPER 70S AND LOWER 80S.
THE OTHER CHANGE TO THE FORECAST WAS TO ADD BACK THE MENTION OF
SEVERE THUNDERSTORMS ON THE PLAINS SATURDAY AFTERNOON. MORNING
MODEL RUNS INDICATE THE FRONTAL BOUNDARY WILL BE SOMEWHERE OVER
NORTHEAST COLORADO SATURDAY MORNING...PROBABLY ACROSS
MORGAN...WELD AND LARIMER COUNTIES. MODEL SOUNDINGS IN THE GREELEY
AREA SHOW MIDDAY CAPE VALUES IN EXCESS OF 2000 J/KG. FAVORABLE
WIND SHEAR PROFILES ALSO LOOK LIKE THEY ARE GOING TO BE IN PLACE
FOR STRONG THUNDERSTORM DEVELOPMENT BY EARLY AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 430 AM MDT FRI MAY 6 2016
THE DEEPENING TROUGH/CLOSED LOW TRACKING SLOWLY E-SEWRD ACROSS
SOUTHERN CALIF IS BEGINNING TO EXERT ITS DOMINANCE ON FLOW AT ALL
LEVELS AND WX AS FAR EAST AS THE SRN AND CNTRL ROCKIES. DEEP S-SWLY
FLOW ON THE FRONT SIDE OF THIS TROUGH CONTINUES TO DIRECT MID AND
HIGH-LEVEL MOISTURE UP INTO THE AREA AND LATER TODAY A SPOKE OF MID-
LEVEL ENERGY AND SHEAR WHICH THE RAP AND OTHER MODELS INDICATE
PASSING OVER NRN NEW MEXICO AT THIS TIME. EVEN WITH VARYING AMOUNTS
OF HIGH CLOUDINESS THIS MORNING STRONG DIABATIC HEATING SHOULD
MANAGE TO GENERATE 8-9C/KM BNDRY LAYER LAPSE RATES AND SFC BASED 600-
1200 J/KG CAPES ON THE PLAINS BY MIDDAY. WHILE THE WELL MIXED
BOUNDARY LAYER APPEAR LACKING OF MOISTURE...MODELS INDICATE A
GRADUAL INCREASE IN MID-LEVEL MOISTURE WITH INCREASING SELY MID-
LEVEL FLOW IN ADVANCE OF THE SHORTWAVE DISTURBANCE SWINGING UP FROM
SERN COLORADO. WHILE CONVECTIVE CLOUDS WILL BE ON THE INCREASE THIS
AFTERNOON...MODELS DO NOT INDICATE MUCH IN THE WAY OF QPF ON THE
PLAINS TODAY. INVERTED-V MODEL SOUNDINGS INDICATE A FAVORABLE SUB-
CLOUD ENVIRONMENT FOR MICROBURST FORMATION THIS AFTERNOON EVEN AS
MEAN LAYER PW VALUES CREEP UPWARD PRIOR TO PASSAGE OF THE U/A
DISTURBANCE TIMED TO OCCUR AROUND 00Z IN THE DENVER AREA. AFTER
00Z/SAT...THE MICROBURST THREAT SHOULD QUICKLY DIMINISH FROM SOUTH
TO NORTH WITH INFLUX OF DRIER MIX-LEVEL AIR BEHIND THE SHORTWAVE.
THIS DRYING IS FORECAST TO CONTINUE EVEN NEAR THE GROUND OVERNIGHT AS
MODELS SHOW A WELL PRONOUNCED DRY SLOT ROTATING UP FROM NEW MEXICO.
FOR THE HIGH COUNTRY...ODDS LOOK BETTER FOR MEASURABLE PRECIP
TODAY...BEGINNING AS EARLY AS LATE THIS MORNING. GREATER MOISTURE...
BETTER SYNOPTIC SCALE LIFT..INSTABILITY AND OROGRAPHICS SHOULD
PROVE ADEQUATE FOR SHOWER AND T-STORM FORMATION. SHOWERS AND
T-STORM MOTIONS WILL PRIMARILY SOUTH-TO-NORTH TODAY. SO THERE`S LITTLE
CHANCE THAT THE PLAINS WILL SEE MUCH IF ANY OF THIS HIGH COUNTRY
CONVECTION. GUSTY WINDS AND SHORT PERIODS OF LIGHT TO MODERATE
RAINFALL POSSIBLE THIS AFTERNOON THRU EARLY EVENING FROM THE
FRONT RANGE WESTWARD. I PUT THE CHANCE OF MEASURABLE PRECIP IN THE
HIGH COUNTRY AT 30-50 PCT...WITH AS FEW POCKETS OF 60 PCT OVER
THE HIGHER PEAKS AND RIDGES ROUGHLY NORTH OF I-70 LATE. LIKE THE
PLAINS...THE CHANCE OF PRECIP IN THE HIGH COUNTRY SHOULD STEADILY
DECREASE WITH CLOUD COVER OVERNIGHT WITH AN INFLUX OF DRIER AIR
FROM THE SOUTH AHEAD OF THE UPPER TROUGH.
TEMPERATURES TODAY WILL BE QUITE WARM AGAIN BUT NOT QUITE RECORD
TERRITORY. RECORD HIGH AT DENVER IS 86. SHOULD SEE LOW 80S IN THE
METRO AREA AND LOW TO MID 80S ACROSS THE PLAINS. HIGH COUNTRY WILL
ALSO BE UNSEASONABLY WARM TODAY WITH HIGHS IN THE UPPER 50S AND
60S. TONIGHT...TEMPERATURE WILL REMAIN QUITE MILD WITH MID 40S/
LOWER 50S ON THE PLAINS AND MOSTLY 30S IN THE HIGH COUNTRY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 430 AM MDT FRI MAY 6 2016
LARGE UPPER LEVEL LOW WILL BE OVER THE GREAT BASIN SATURDAY. A
STRONG WAVE EMBEDDED IN THE SOUTHWEST FLOW ALOFT WILL MOVE ACROSS
EASTERN COLORADO SATURDAY AND EVENTUALLY BECOME THE NEW CENTER OF
THE UPPER LEVEL LOW SOMEWHERE OVER WYOMING OR NORTHEAST COLORADO.
FOR SATURDAY...A SURFACE LOW WILL BE OVER NORTHEAST COLORADO WITH
A BOUNDARY DRAPED ACROSS THE AREA. EASTERLY WINDS NORTH OF IT WILL
PUMP MOISTURE INTO THE AREA. SURFACE BASED CAPES WILL BE UP TO
2000 J/KG. THIS COMBINED WITH GOOD SHEAR IS EXPECTED TO PRODUCE
SEVERE THUNDERSTORMS WITH LARGE HAIL...STRONG WINDS AND POSSIBLY A
FEW TORNADOS. STILL SOME UNCERTAINTY WHERE THIS BOUNDARY WILL SET
UP. LATEST MODEL RUNS ARE LITTLE MORE NORTH AND HAS MOST OF THE
CONVECTION NORTH OF A LINE FROM FORT COLLING TO AKRON. STILL
WOULDN`T BE SURPRISED IF THIS BOUNDARY ENDS UP FARTHER SOUTH THAN
THE MODELS ARE FORECASTING.
ON SUNDAY...THE ECMWF HAS THE CENTER OF THE UPPER LEVEL LOW OVER
NORTHEAST COLORADO WHILE THE GFS SHOWS IT OVER WYOMING. NO STRONG
FEELING WHICH ONE IS RIGHT. IT WILL BE COOL AND IF THE LOW FORMS
OVER COLORADO...EXPECT MORE PRECIPITATION ACROSS THE AREA.
NORTHWEST FLOW WILL PREVAIL MONDAY AS THE UPPER LEVEL LOW WEAKENS
EAST OF COLORADO. STILL SHOULD BE ENOUGH MOISTURE AND INSTABILITY
TO TRIGGER SCATTERED/ISOLATED SHOWERS AND STORMS. ANOTHER UPPER
LEVEL LOW WILL MOVE INTO THE NORTHERN ROCKIES MONDAY. THIS LOW IS
EXPECTED TO DIG SOUTH INTO WYOMING TUESDAY. ISOLATED TO SCATTERED
CONVECTION WILL AGAIN BE POSSIBLE. THIS LOW IS EXPECTED TO MOVE
EAST OF THE AREA WEDNESDAY AND THURSDAY. COULD SEE A FEW SHOWERS
AND STORMS WEDNESDAY...BUT DRIER AND WARMER CONDITIONS SHOULD
PREVAIL THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1053 AM MDT FRI MAY 6 2016
THROUGH THIS AFTERNOON AND TONIGHT...VFR CONDITIONS SHOULD
CONTINUE AT DENVER AREA AIRPORTS. THE DEVELOPMENT OF SOME
AFTERNOON SHOWERS WITH MICROBURST POTENTIAL STILL EXISTS THIS
AFTERNOON. GUSTS UP TO 40-45 MPH MAY ACCOMPANY THE HIGH BASED
SHOWERS. STORM MOTIONS WILL BE FROM SOUTH TO NORTH...GIVEN THE
INCREASING SOUTHERLY FLOW ALOFT IN PLACE OVER EASTERN COLORADO
TODAY. MOST SHOWER ACTIVITY SHOULD BE OVER BY 7 PM TO 8 PM.
SOUTHERLY WINDS ARE EXPECTED TO CONTINUE OVERNIGHT...ALTHOUGH THEY
COULD BE A BIT GUSTY AT TIMES. MORE THUNDERSTORMS ARE EXPECTED
SATURDAY AFTERNOON WHICH MAY BRING SOME HEAVY RAINS AND CEILINGS
DOWN TO MVFR AT TIMES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DANKERS
SHORT TERM...BAKER
LONG TERM...MEIER
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS ALBANY NY
408 PM EDT FRI MAY 6 2016
.SYNOPSIS...
SLOW MOVING LOW PRESSURE SYSTEM ALONG THE MIDDLE ATLANTIC
COASTLINE WILL CONTINUE TO IMPACT OUR REGION WITH CLOUDS AND
PERIODS OF WET WEATHER. THIS STORM BEGINS TO LIFT AWAY DURING
SATURDAY...HOWEVER...A STRONG COLD FRONT WILL CROSS THE REGION
SATURDAY NIGHT. THIS WILL PROVIDE ADDITIONAL SHOWERS THAT WILL
END FROM WEST TO EAST EARLY SUNDAY MORNING. BRISK CONDITIONS ARE
EXPECTED FOR MOTHERS DAY WITH THE CHANCE FOR MORE SHOWERS DURING
THE AFTERNOON HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM EDT...H2O VAPOR LOOP REVEALS OUR PERSISTENT QUASI-
STATIONARY UPPER LEVEL LOW NEAR DELMARVA WITH DEFORMATION AXIS
ALONG I81 CORRIDOR. AN ADDITIONAL WAVE SEEN JUST OFFSHORE WAS
ADVANCING NORTH-NORTHWEST. PER THE HRRR...SEEMS THIS WAVE WILL
ENHANCE THE LIFT FOR MORE SHOWER DEVELOPMENT THROUGH THE EVENING
HOURS. THIS SHOULD ROTATE FURTHER WEST WITH SOMEWHAT IMPROVING
CONDITIONS TOWARD MIDNIGHT. YET CLOUDS AND SOME PATCHY FOG SHOULD
PERSIST AS OVERNIGHT LOWS SHOULD DROP ABOUT 10 DEGREES FROM THIS
AFTERNOONS HIGHS AS LOWER LEVEL THERMAL PROFILES DO NOT CHANGE
TOO MUCH.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
SATURDAY...LATEST MODEL TRENDS SUGGEST THE OMEGA PATTERN BEGINS TO
BREAK DOWN AS OUR UPPER LOW BEGINS TO DIMINISH AND LIFT EASTWARD.
SO IT APPEARS THE BEST CHANCE FOR SHOWERS WILL BE ACROSS THE
SOUTHEAST 2/3RDS OF THE REGION IN CLOSER PROXIMITY OF THE
DEPARTING UPPER LOW. UPSTREAM...H2O VAPOR LOOP DEPICTS A RATHER
SHARP SHORT WAVE TROUGH AXIS TRACKING EAST-SOUTHEAST INTO THE
NORTHERN TIER OF THE CONUS. SO THERE COULD BE A BRIEF WINDOW OF
MINIMAL SHOWER COVERAGE THROUGH THE AFTERNOON BEFORE THIS
AFOREMENTIONED UPSTREAM SYSTEM APPROACHES. SO CONSIDERABLE CLOUD
COVERAGE /SOME BREAKS OF SUNSHINE/...AND SLIGHTLY MODERATING
TEMPERATURES WITH VALLEY TEMPERATURES INTO THE 60S WITH 50S
ELSEWHERE.
THIS UPSTREAM SYSTEM PROGRESSIVELY MOVES ACROSS SATURDAY NIGHT
WITH A PERIOD OF SHOWERS. THE BEST QG FORCING RIDES MAINLY ALONG
AND NORTH OF I90 WHERE WE WILL PLACE THE HIGHEST POPS. AS FOR
CONVECTIVE POTENTIAL...MID LEVEL LAPSE RATES LOOK LESS THAN IDEAL
WITH SHOWALTER VALUES REMAINING RATHER POSITIVE. SO WE WILL
WITHHOLD THE MENTION OF THUNDER AT THIS TIME. OVERNIGHT LOWS
MAINLY INTO THE 40S.
FOR MOTHERS DAY, DEPARTING SHOWERS EAST OF I87 THEN AN ISALLOBARICRISE
COUPLET MOVES ACROSS FOR RATHER BRISK CONDITIONS TO EVOLVE. PER
BUFKIT PROFILES MOMENTUM TRANSFER...WE TAP INTO THE 30KT RANGE AS
THESE VALUES SHOULD REMAIN BELOW HEADLINE CRITERIA. H850 TEMPS
DROP BACK TO BELOW ZERO ACROSS THE DACKS WITH LOWER SINGLE DIGITS
ELSEWHERE. SO HIGH TEMPERATURES COULD BE ACHIEVED AROUND THE NOON
HOUR WITH STEADY TO SLOWING FALLING TEMPERATURES IN THE AFTERNOON.
IMPROVING CONDITIONS SUNDAY NIGHT AS IT COULD BECOME QUITE CHILLY
WITH PARTIAL CLEARING FOR MOST OF THE REGION. LAKE EFFECT ACTIVITY
OFF ONTARIO MAY KEEP IN THE CLOUDS A BIT LONGER AND SOME SHOWERS
YET THE SUBSIDENCE INVERSION LOOKS TO BE BELOW 5K FEET SO WE WILL
KEEP IT DRY FOR NOW.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
LATEST 06/12Z MODEL AND PROBABILISTIC GUIDANCE SHOWS MERIDIONAL
UPPER LEVEL FLOW OVER THE NORTHERN 2/3 CONUS. FOR OUR
REGION...SURFACE HIGH PRESSURE WILL BE OVER OUR REGION FOR THE FIRST
HALF OF THE EXTENDED PERIOD AS OUR REGION WILL BE IN A LARGE
FAVORABLE REGION OF SOME UPPER LEVEL CONVERGENCE. TEMPERATURES WILL
BE AVERAGE TO SLIGHTLY ABOVE AVERAGE FOR EARLY INTO MID MAY.
OVERALL...THE EXTENDED FORECAST PERIOD WILL REMAIN RATHER TRANQUIL.
A DEVELOPING SURFACE LOW PRESSURE SYSTEM ACROSS THE CENTRAL PLAINS
DURING THE DAY ON TUESDAY WILL HAVE A TRAILING W-E STATIONARY FRONT
FROM THE OHIO VALLEY INTO THE MID ATLANTIC STATES. THIS WILL BE THE
FOCUS FOR LOW PRESSURE PERTURBATIONS ALONG THE ESTABLISHED
BAROCLINIC ZONE. SOME OF THE LATEST 12Z GUIDANCE SHOWS SOME MOISTURE
WORKING ITS WAY NORTHWARD INTO PARTS THE REGION AT TIMES ASSOCIATED
WITH THESE LOW PRESSURE PERTURBATIONS WHICH WILL BRING SLIGHT CHANCE
TO CHANCE POPS...ESPECIALLY ACROSS OUR SOUTHERN REGION.
AS WE GO INTO THE DAY ON THURSDAY...A DIGGING TROUGH ACROSS THE
UPPER MIDWEST WILL DEVELOP WHICH WILL FURTHER ENHANCE AN UPPER LEVEL
RIDGE ON THE EASTERN SEABOARD BY THURSDAY AFTERNOON. UNDER THE UPPER
LEVEL RIDGE...TRANQUIL WEATHER WILL BE ESTABLISHED OVER THE ENTIRE
REGION AS WE GO TOWARDS THE END OF THE EXTENDED PERIOD.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FLYING CONDITIONS ARE CURRENTLY VFR AT KALB/KPSF/KGFL AND MVFR AT
KPOU. THE STEADIEST AND HEAVIEST RAINFALL IS NOW WEST OF THE TAF
SITES...BUT RADAR TRENDS AND THE 3KM HRRR SUGGEST SOME ADDITIONAL
RAIN SHOWERS WILL MOVE ACROSS THE REGION LATER THIS AFTERNOON INTO
THIS EVENING. THESE ADDITIONAL RAIN SHOWERS MAY LOWER VSBYS/CIGS
DOWN TO MVFR AT TIMES. LIGHT N-NE WINDS WILL GENERALLY BE 5 KTS OR
LESS.
DURING THE OVERNIGHT HOURS...SOME ADDITIONAL RAIN SHOWERS WILL BE
POSSIBLE. CIGS WILL GENERALLY REMAIN MVFR AT KGFL/KALB...SOME CIGS
MAY EVEN LOWER DOWN TO IFR AT KPOU/KPSF DUE TO THE EARLIER
RAINFALL TODAY KEEPING LOW LEVELS RATHER MOIST. WINDS WILL BE
LIGHT AND VARIABLE OVERNIGHT.
SOME IMPROVEMENT IN CIGS IS POSSIBLE BY THE MID TO LATE MORNING
HOURS ON SATURDAY...OTHERWISE MVFR CONDITIONS LOOK TO CONTINUE FOR
ALL SITES. WINDS WILL CONTINUE TO BE FAIRLY LIGHT AND VARIABLE.
OUTLOOK...
SAT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SAT NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
SUN: MODERATE OPERATIONAL IMPACT. WINDY. CHANCE OF SHRA.
SUN NIGHT-MON NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUE: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.FIRE WEATHER...
RECENT SOGGY CONDITIONS AND CLOUD COVERAGE HAS KEPT THE RELATIVE
HUMIDITY VALUES ELEVATED TO REDUCE FIRE WEATHER CONCERNS.
ADDITIONAL SHOWERS THROUGH THE WEEKEND AND ELEVATED MOISTURE
LEVELS SHOULD KEEP THE REGION RATHER MOIST. WINDS INCREASE ON
SUNDAY WITH WEST-NORTHWEST WINDS INCREASING TO BETWEEN 25 AND 35
MPH POSSIBLE.
&&
.HYDROLOGY...
MINIMAL HYDROLOGY RELATED ISSUES THROUGH THE WEEKEND INTO EARLY
NEXT WEEK AS LATEST REGIONAL BASIN RAINFALL AMOUNTS ARE EXPECTED
TO AVERAGE ONE HALF OF AN INCH. THE HIGHER TERRAIN MAY EXPERIENCE
SLIGHTLY HIGHER VALUES BUT EXPECTATIONS ARE FOR WITHIN BANK RIVER
RISES. THE ONLY SLIGHT CONCERN HAS BEEN TIDAL CONDITIONS ALONG THE
HUDSON AS THE PERSISTENT UPPER LOW OVER DELMARVA ALONG WITH
SOUTHEAST LOW LEVEL WINDS MAY BRING WATER LEVELS TOWARD ACTION
STAGE THROUGH THE FIRST HALF OF THE WEEKEND.
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...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...LFM
AVIATION...FRUGIS
FIRE WEATHER...BGM/JPV
HYDROLOGY...FRUGIS/BGM/JPV
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
126 PM EDT FRI MAY 6 2016
.SYNOPSIS...
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO
RESULT IN PLENTY OF CLOUDS AND COOL TEMPERATURES TODAY. SOME RAIN
IS ALSO EXPECTED TODAY INTO THIS EVENING. TEMPERATURES WILL
MODERATE SATURDAY AS THE UPPER LEVEL LOW FINALLY MOVES AWAY FROM
THE REGION. A COLD FRONT WILL THEN CROSS THE AREA LATE SATURDAY
NIGHT INTO SUNDAY...BRINGING ANOTHER ROUND OF SHOWERS. IN ITS
WAKE...DRY AND BREEZY CONDITIONS WILL BE IN STORE FOR MUCH OF
MOTHERS DAY WITH COOL TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF NOON EDT...NOT MUCH CHANGE TO THE OVERALL FORECAST AS UPPER
LOW REMAINS QUASI-STATIONARY ALONG THE MID-ATLANTIC COASTLINE.
WAVES OF RAIN SHOWERS CONTINUE TO PIVOT NORTH THEN NORTHWEST
ACROSS THE SOUTHERN HALF OF THE REGION AS H2O VAPOR LOOP REVEALS A
DRY SLOT APPROACHING NYC/LI AND THE MID HUDSON VALLEY. HOWEVER...
ANOTHER AREA OF MOIST ADVECTION WAS SEEN OFF THE MID ATLANTIC
COAST ADVANCING NORTH-NORTHWEST AS PER THE HRRR/RAP13...THIS MAY
REINVIGORATE ADDITIONAL SHOWER DEVELOPMENT THROUGH THE AFTERNOON
AND EVENING HOURS. SO MADE ADJUSTMENTS TO THE POP/WX FIELDS...SKY
COVERAGE PER 1KM VIS IMAGERY AND TWEAK HOURLY TEMPS PER OBS.
TEMPERATURES ARE EXPECTED TO WARM INTO THE 60S ACROSS THE
NORTHERN HALF OF THE AREA WHERE ONSET OF RAIN IS DELAYED UNTIL
THIS AFTERNOON...AND ESPECIALLY FOR AREAS WHERE CLEARING HAS
OCCURRED EARLY THIS MORNING. COOLER 50S WILL CONTINUE ACROSS
SOUTHERN AREAS WHERE CLOUDS/RAIN WILL MOVE IN QUICKER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
RAIN WILL BECOME MORE INTERMITTENT AND SHOWERY THIS EVENING AS
THE CUT-OFF LOW HALTS ITS NORTHWARD PROGRESS NEAR THE MASON-DIXON
LINE AS IT BEGINS TO FILL/WEAKEN. PLENTY OF CLOUDS WILL LINGER
THROUGH TONIGHT WITH PLENTY OF RESIDUAL LOW LEVEL MOISTURE. WILL
GRADUALLY DECREASE POPS OVERNIGHT...BUT STILL MENTION SLIGHT/LOW
CHANCE INTO SATURDAY MORNING.
SATURDAY COULD END UP BEING THE NICEST DAY WE HAVE SEEN SINCE
APRIL ACROSS THE AREA...BUT WE WILL LIKELY HAVE TO WAIT UNTIL
AFTERNOON FOR MANY LOCATIONS TO SEE PARTIAL SUNSHINE. THE CUT-OFF
LOW IS EXPECTED TO FINALLY DEPART AS IT TRACKS SOUTHEASTWARD OFF
THE MID ATLANTIC COAST DUE TO A DIGGING UPSTREAM TROUGH ACROSS THE
UPPER GREAT LAKES. SOME BRIEF RIDGING SHOULD DEVELOP DURING THE
AFTERNOON WHICH SHOULD ALLOW FOR AT LEAST SOME BREAKS OF SUNSHINE.
WILL STILL HAVE TO CARRY LOW CHANCE POPS THROUGH MUCH OF THE DAY
FOR A PASSING SHOWER OR TWO...AS WE WILL STILL BE IN A CYCLONIC
FLOW THROUGH AROUND MID AFTERNOON. TEMPS SHOULD REACH THE LOWER TO
MID 60S BY LATE AFTERNOON FOR MUCH OF THE AREA.
SATURDAY NIGHT THE AFOREMENTIONED UPPER LEVEL TROUGH AND ITS
ASSOCIATED COLD FRONT WILL CONTINUE TO DIVE SOUTHEASTWARD ACROSS
THE GREAT LAKES AND EVENTUALLY INTO OUR REGION. GOOD LOW LEVEL
CONVERGENCE AND UPWARD VERTICAL MOTION ALONG THE COLD FRONT AND
AHEAD OF THE LEADING SHORT WAVE WILL RESULT IN A PERIOD OF
SHOWERS. THERE IS ENOUGH CONFIDENCE TO MENTION LIKELY TO
CATEGORICAL POPS FROM LATE SATURDAY NIGHT INTO EARLY SUNDAY
MORNING.
AFTER A FEW LINGERING SHOWERS ACROSS EASTERN AREAS SUNDAY
MORNING...IT WILL TURN BREEZY...COOLER AND DRIER FOR SUNDAY
AFTERNOON BEHIND THE COLD FRONT. THE MAIN STORY WILL BE GUSTY W-NW
WINDS ESPECIALLY DURING THE AFTERNOON INTO THE EARLY EVENING
HOURS. GOOD MIXING DEVELOPING DUE TO COLD ADVECTION WILL LIKELY
RESULT IN WINDS GUSTING TO BETWEEN 25 AND 35 MPH ACROSS THE
REGION...WITH SOME ISOLATED 40 MPH GUSTS. WINDS WILL GRADUALLY
DECREASE SUNDAY NIGHT WITH DRY CONDITIONS PERSISTING. IT WILL BE
NOTICEABLY COOLER THAN RECENT NIGHTS...WITH MID 30S TO LOWER 40S
FORECAST AT THIS TIME.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
OVERALL ACTIVE WEATHER WILL CONTINUE WITH BELOW NORMAL DAYTIME
HIGHS AND ABOVE NORMAL NIGHTTIME LOWS.
MODEL GUIDANCE IS IN AGREEMENT THAT RIDGING WILL BUILD IN MONDAY
AND MONDAY NIGHT RESULTING IN FAIR WEATHER ACROSS THE AREA. HOWEVER
THIS WILL BE SHORT LIVED. A PIECE OF SOUTHERN STREAM ENERGY WILL
QUICKLY APPROACH FROM THE PLAINS TUESDAY. THIS ENERGY WILL GET
ABSORBED INTO THE DEVELOPING LONGWAVE TROUGH AS PIECES OF
NORTHERN STREAM ENERGY ROTATE ABOUT AN UPPER LEVEL LOW AS IT
MOVES OVER EASTERN QUEBEC AND NEWFOUNDLAND/LABRADOR THIS WEEK.
AT THE SURFACE...A WARM FRONT EXTENDING WELL EASTWARD FROM LOW
PRESSURE OVER THE PLAINS WILL APPROACH ON TUESDAY. WILL HAVE
INCREASING CHANCES FOR WET WEATHER/RAIN ESPECIALLY THROUGH THE
AFTERNOON HOURS INTO THE EVENING. THE BOUNDARY IS NOT EXPECTED TO
LIFT NORTHWARD INTO THE AREA AS THE UPPER FLOW SHOULD KEEP THE
BOUNDARY SUPPRESSED TO OUR SOUTH. A WAVE OF LOW PRESSURE IS
FORECAST TO MOVES EASTWARD ALONG THE FRONT AND PASS TO OUR SOUTH
SOMETIME WEDNESDAY. THERE ARE TIMING DIFFERENCES IN THE GUIDANCE
WHEN EXACTLY THIS HAPPENING...HOWEVER THE PATTERN IS WET WITH OUR
AREA TO THE NORTH OF THE BOUNDARY AND LOW.
AS WE HEAD INTO THE LATTER PART OF THE WEEK...RIDGING IS ANTICIPATED
TO BUILD IN AND MOVE ACROSS THE REGION THURSDAY WITH ANOTHER LOW
PRESSURE SYSTEM ON THE APPROACH.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
FLYING CONDITIONS ARE CURRENTLY VFR AT KALB/KPSF/KGFL AND MVFR AT
KPOU. THE STEADIEST AND HEAVIEST RAINFALL IS NOW WEST OF THE TAF
SITES...BUT RADAR TRENDS AND THE 3KM HRRR SUGGEST SOME ADDITIONAL
RAIN SHOWERS WILL MOVE ACROSS THE REGION LATER THIS AFTERNOON INTO
THIS EVENING. THESE ADDITIONAL RAIN SHOWERS MAY LOWER VSBYS/CIGS
DOWN TO MVFR AT TIMES. LIGHT N-NE WINDS WILL GENERALLY BE 5 KTS OR
LESS.
DURING THE OVERNIGHT HOURS...SOME ADDITIONAL RAIN SHOWERS WILL BE
POSSIBLE. CIGS WILL GENERALLY REMAIN MVFR AT KGFL/KALB...SOME CIGS
MAY EVEN LOWER DOWN TO IFR AT KPOU/KPSF DUE TO THE EARLIER
RAINFALL TODAY KEEPING LOW LEVELS RATHER MOIST. WINDS WILL BE
LIGHT AND VARIABLE OVERNIGHT.
SOME IMPROVEMENT IN CIGS IS POSSIBLE BY THE MID TO LATE MORNING
HOURS ON SATURDAY...OTHERWISE MVFR CONDITIONS LOOK TO CONTINUE FOR
ALL SITES. WINDS WILL CONTINUE TO BE FAIRLY LIGHT AND VARIABLE.
OUTLOOK...
SAT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SAT NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA.
SUN: MODERATE OPERATIONAL IMPACT. WINDY. CHANCE OF SHRA.
SUN NIGHT-MON NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUE: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.FIRE WEATHER...
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO
RESULT IN PLENTY OF CLOUDS AND COOL TEMPERATURES TODAY. SOME RAIN
IS ALSO EXPECTED TODAY INTO THIS EVENING. TEMPERATURES WILL
MODERATE SATURDAY AS THE UPPER LEVEL LOW FINALLY MOVES AWAY FROM
THE REGION. A COLD FRONT WILL THEN CROSS THE AREA LATE SATURDAY
NIGHT INTO SUNDAY...BRINGING ANOTHER ROUND OF SHOWERS. IN ITS
WAKE...DRY AND BREEZY CONDITIONS WILL BE IN STORE FOR MUCH OF
MOTHERS DAY WITH COOL TEMPERATURES.
MINIMUM RELATIVE HUMIDITY VALUES THIS AFTERNOON WILL DROP TO
AROUND 40 TO 50 PERCENT ACROSS NORTHERN AREAS AND 55 TO 75 PERCENT
ACROSS SOUTHERN AREAS. RH VALUES WILL INCREASE TO BETWEEN 90 AND
100 PERCENT TONIGHT...DROPPING TO AROUND 50 TO 70 PERCENT SATURDAY
AFTERNOON.
WINDS TODAY WILL BE NORTHEAST AROUND 5 TO 15 MPH...BECOMING EAST
AT 5 TO 10 MPH TONIGHT. WINDS WILL SHIFT TO THE SOUTHEAST ON
SATURDAY AT 5 TO 10 MPH.
&&
.HYDROLOGY...
UNSETTLED WEATHER WILL CONTINUE FOR THE NEXT FEW DAYS AS AN UPPER
LEVEL LOW MEANDERS CLOSE TO THE REGION. SOME RAIN WILL OCCUR
ACROSS MUCH OF THE REGION TODAY INTO THIS EVENING. A FEW
ADDITIONAL RAIN SHOWERS ARE POSSIBLE ON SATURDAY WITH THE UPPER
LOW NEARBY. MORE SHOWERS EXPECTED SATURDAY NIGHT INTO SUNDAY
MORNING WITH THE PASSAGE OF A COLD FRONT. DRY WEATHER SHOULD
RETURN FOR MUCH OF SUNDAY INTO MONDAY.
TOTAL QPF THROUGH THE WEEKEND LOOKS TO BE AROUND A HALF TO TWO
THIRDS OF AN INCH...WITH SOME HIGH TERRAIN /ESPECIALLY IN THE
CATSKILLS/ SEEING CLOSE TO AN INCH. WITH VEGETATION CONTINUING TO
GREEN UP...THIS RAINFALL WILL NOT CAUSE ANY HYDROLOGY ISSUES FOR
RIVERS AND STREAMS. ONLY VERY MODEST RISES ARE EXPECTED ON AREA
RIVERS AND STREAMS THROUGH EARLY NEXT WEEK.
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...JPV
NEAR TERM...FRUGIS/BGM/JPV
SHORT TERM...JPV
LONG TERM...IAA
AVIATION...FRUGIS
FIRE WEATHER...JPV
HYDROLOGY...FRUGIS/JPV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
158 PM EDT FRI MAY 6 2016
.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE INTO OUR AREA FROM THE SOUTHEAST
LATER TODAY, THEN LINGER THROUGH SATURDAY BEFORE DISSIPATING. A COLD
FRONT WILL MOVE THROUGH SUNDAY MORNING, FOLLOWING BY HIGH PRESSURE
SUNDAY NIGHT INTO MONDAY BEFORE MOVING OFFSHORE. A WARM FRONT LIFTS
NORTH ACROSS OUR AREA DURING TUESDAY, THEN STALLS IN OUR AREA
WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME HEAVIER SHOWERS HAVE BEEN TRAVERSING THE REGION THIS MORNING
WITH SCATTERED SHOWERS CONTINUING ACROSS THE AREA. EXPECT THE
HEAVIER RAIN TO CONTINUE TO PUSH TO THE WEST-SOUTHWEST AND OUT OF
THE AREA THIS MORNING. LIGHT TO MODERATE RAIN SHOWERS WILL
CONTINUE THROUGH THE REST OF THE DAY WITH SOME TAPERING OFF
EXPECTED FROM EAST TO WEST LATER IN THE DAY.
SPC HAS EXPANDED THE AREA OF GENERAL THUNDER SO HAVE INCLUDED A
SLIGHT RISK THROUGH THIS AFTERNOON ACROSS THE ENTIRE AREA. CONSIDERABLE
INSTABILITY ALOFT SUGGEST POTENTIAL FOR ISOLATED THUNDER/ASSOCIATED
SMALL HAIL WITH VERY STEEP MID LVL LAPSE RATES AND LOW WBZ NEAR
6000 FT. NOT SURE WHAT WILL TRIGGER THE THUNDER EXCEPT SFC
CONVERGENCE WITH THE LOW COMING ASHORE AND PERHAPS SOME AFTERNOON
SFC HEATING NEAR THE APPROACHING LOW OVER DE. TEMPS MAY BE SEVERAL
DEGREES COLDER THAN YDY I95 NWWD.
A GUSTY NE WIND FOR A TIME THIS MORNING NEAR 20 MPH EXCEPT GUSTS
MIDDAY AND EARLY AFTERNOON MONMOUTH AND OCEAN COUNTIES MAY APPROACH
35 MPH (SEE HRRR GUSTS AS A BAND OF STRONGER WIND WELL NORTH OF
THE LOW CENTER SHIFTS WESTWARD WITH LOW ALONG THE S SHORE OF LI).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HAVE UNCERTAINTY REGARDING TIMING OF ANY SHOWERS AND ANY LEFTOVER
ISOLATED EVENING TSTMS (SE PA/S NJ). CONFIDENCE ON WHAT OCCURS
AND WHERE, IS BELOW AVERAGE. IN PART THIS IS DUE TO RECENT LOSS
OF CONFIDENCE IN GFS QPF FCSTS. NE WIND DIMINISHING THIS EVENING
AND BECOMING LIGHT SOUTHERLY ON THE DELMARVA, POSSIBLY EVEN TO
I95.
FOG MAY BECOME A PROBLEM TONIGHT WITH A LIGHT WIND IN THE MIDST
OF VERTICALLY STACKED MOIST LOW PRESSURE SYSTEM.
FCST WAS A 50 50 BLEND OF THE 00Z/6 GFS/NAM MOS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN INITIAL CLOSED LOW CENTERED
OVER OUR AREA SATURDAY, HOWEVER THIS FEATURE OPENS UP DURING
SATURDAY AS IT SHIFTS EASTWARD. THIS OCCURS AS A STRONG SHORT WAVE
TROUGH DIVES SOUTHEASTWARD ACROSS THE GREAT LAKES SATURDAY AND INTO
THE NORTHEAST SATURDAY NIGHT AND SUNDAY. THE NEW TROUGH AMPLIFIES
ACROSS THE NORTHEAST SUNDAY BEFORE GRADUALLY LIFTING OUT MONDAY. A
WEAK RIDGE THEN ARRIVES FOR EARLY NEXT WEEK WITH A SURFACE WARM
FRONT ALSO MOVING THROUGH. THE WARM FRONT HOWEVER MAY END UP
STALLING IN OUR VICINITY WEDNESDAY AND THURSDAY AS ENERGY SHEARS
EASTWARD ALONG IT. GIVEN THE PATTERN CHANGE, MUCH WARMER AIR IS
EXPECTED TO ARRIVE NEXT WEEK WITH THIS CHANGE STARTING OVER THE
WEEKEND ESPECIALLY DURING SUNDAY. THE EXTENT OF THE WARMING THOUGH
NEXT WEEK WILL DEPEND ON THE PLACEMENT OF THE FRONTAL BOUNDARY AS IT
MAY MEANDER ACROSS OUR CWA AND ALSO PRECIPITATION CHCS. WE USED A
MODEL BLEND APPROACH FOR SATURDAY THROUGH SUNDAY NIGHT, THEN BLENDED
IN THE 00Z WPC GUIDANCE THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR SATURDAY AND SUNDAY...THIS TIME FRAME BEGINS WITH A CLOSED LOW
RIGHT OVER OUR AREA SATURDAY MORNING, HOWEVER THIS FEATURE WILL OPEN
UP AND SHIFT EASTWARD DURING THE COURSE OF THE DAY. THIS WILL BE DUE
TO A KICKER SHORT WAVE TROUGH AMPLIFYING ACROSS THE GREAT LAKES
REGION. A CORE OF -20C TO -24C AIR AT 500 MB IS OVER OUR AREA
SATURDAY MORNING, HOWEVER THIS MODIFIES THROUGH THE DAY AS THE
TROUGH OPENS UP AND SHIFTS TO OUR EAST. THE PRESENCE OF COLD AIR
ALOFT COMBINED WITH SOME LIFT FROM THE CLOSED LOW SHOULD RESULT IN
MAINLY SCATTERED SHOWERS SATURDAY ESPECIALLY INLAND. THE FLOW IS
LIGHT UNDER THE CLOSED LOW THEREFORE SHOWERS SHOULD BE SLOW MOVERS.
SINCE THE AIRMASS IS WARMING DURING THE COURSE OF THE DAY, THIS MAY
MITIGATE THE INSTABILITY POTENTIAL. IT APPEARS ANY INSTABILITY IS
MARGINAL AND THEREFORE THUNDER WAS NOT ADDED FOR SATURDAY ATTM. AS
WE LOSE THE CONTINUOUS ONSHORE FLOW COMPONENT AND THE TROUGH ALOFT
WEAKENING THROUGH SATURDAY, THERE SHOULD BE AT LEAST SOME BREAKS OF
SUNSHINE.
AN AMPLIFYING TROUGH FROM THE GREAT LAKES THEN STARTS TO NEAR OUR
AREA TOWARD DAYBREAK SUNDAY. LOW PRESSURE TRACKING TO OUR NORTH WILL
PULL A COLD FRONT INTO OUR AREA LATE SATURDAY NIGHT AND THIS FRONT
MAY MOVE IN A BIT FASTER. THERE APPEARS TO BE A PLUME OF DEEPER
MOISTURE IN COMBINATION WITH FORCING FOR ASCENT TO DRIVE SOME SHOWERS
/PERHAPS A BAND OF SHOWERS/ ACROSS MUCH OF OUR AREA. THE STRONGEST
FORCING MAY GLANCE OUR NORTHERN AREAS AND THEREFORE THE HIGHEST POPS
WERE PLACED THERE LATER AT NIGHT. ANY SHOWERS SHOULD QUICKLY SHIFT
OFFSHORE SUNDAY MORNING AS THE COLD FRONT ALSO EXITS, THEN DRIER AIR
AND BETTER MIXING WILL PROMOTE SUNSHINE FINALLY RETURNING FOR THE
AFTERNOON. IT WILL BE A BIT BREEZY THOUGH SUNDAY IN THE WAKE OF THE
COLD FRONT AS LOW-LEVEL LAPSE RATES STEEPEN AND THE PRESSURE
GRADIENT TIGHTENS. WE WENT A BIT WARMER THAN MOS FOR SUNDAY
ESPECIALLY FOR THE COASTAL PLAIN GIVEN DOWNSLOPING FLOW. HIGH
PRESSURE THEN STARTS TO ARRIVE SUNDAY NIGHT ALLOWING THE WINDS TO
DIMINISH.
FOR MONDAY AND TUESDAY...SOME WEAK RIDGING ARRIVES DURING MONDAY,
ALLOWING SURFACE HIGH PRESSURE TO BE OVER OUR CWA TO START BUT IT
LOOKS TO SHIFT OFFSHORE LATER MONDAY. THIS WILL ALLOW A SOUTHERLY
FLOW TO BECOME BETTER ESTABLISHED AND WITH DOWNSTREAM WAA
INCREASING, A WARMER TIME FRAME IS EXPECTED. THE WAA WILL BE USHERED
IN VIA A WARM FRONT AS IT CROSSES THE AREA DURING TUESDAY, AND THERE
COULD BE ENOUGH LIFT TO PRODUCE SOME SHOWERS OR A THUNDERSTORM
MAINLY TUESDAY AFTERNOON AND NIGHT. THE FORECAST CHALLENGE IS THAT
THIS FRONT MAY THEN STALL IN OUR AREA AS ENERGY INITIALLY SHEARS
EASTWARD ALONG IT. THIS SHEARING ENERGY COULD PRODUCE SOME
CONVECTION.
FOR WEDNESDAY AND THURSDAY...THE FORECAST CHALLENGE IS WITH THE
FRONTAL ZONE AS IT LOOKS TO BE DRAPED ACROSS OUR AREA, HOWEVER A
TROUGH AMPLIFYING ACROSS NEW ENGLAND WEDNESDAY MAY PUSH THE FRONT
FARTHER SOUTHWARD. THIS SOUTHWARD PUSH COULD BE ENHANCED AS HIGH
PRESSURE MAY BUILD DOWN SOME FROM NORTHERN NEW ENGLAND. A TROUGH IN
THE MIDWEST HOWEVER PUSHES SURFACE LOW PRESSURE UP THE OHIO VALLEY
WEDNESDAY NIGHT INTO THURSDAY, WITH DOWNSTREAM WAA AND SOUTHERLY
FLOW ALLOWING THE BOUNDARY TO START LIFTING NORTHWARD SOME AS A WARM
FRONT. THIS TIME FRAME SHOULD BE ON THE WARMER SIDE, HOWEVER THIS
WILL ULTIMATELY DEPEND ON THE POSITIONING OF THE FRONTAL BOUNDARY
AND ANY CONVECTION THAT OCCURS. GIVEN THE UNCERTAINTY, WE BLENDED
THE 00Z WPC GUIDANCE IN WITH CONTINUITY AND THEN MADE SOME TWEAKS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
SHOWERS HAVE LARGELY CLEARED THE TERMINALS WITH ONLY SOME SHOWERS,
POSSIBLY AN ISOLATED THUNDERSTORM, AFFECTING KRDG THROUGH 19Z. LOW
PRESSURE CONTINUES TO PUSH WESTWARD FROM THE ATLANTIC AND INTO OUR
AREA. AS THIS OCCURS, THE ATMOSPHERE WILL DRY ALOFT WHILE THE LOW
LEVELS CONTINUE TO HAVE CONSIDERABLE MOISTURE. THIS WOULD LEAD TO
MORE OF A DRIZZLE EVENT AND WE TRANSITION THE TERMINALS TO DRIZZLE
FROM 22Z-00Z AND THROUGH MUCH OF THE NIGHT.
WITH THE LOW LEVEL MOISTURE IN PLACE, LOW CLOUDS WILL CERTAINLY BE
THE BIGGEST ISSUE AFFECTING THE TERMINALS THROUGH THE PERIOD. BASES
WILL GRADUALLY FALL THIS AFTERNOON AND EVENING TO BELOW 1000FT,
DROPPING AS LOW AS 400 FT AT SOME LOCATIONS. LIFR/IFR CONDITIONS ARE
EXPECTED TO CONTINUE THROUGH THE OVERNIGHT HOURS INTO SATURDAY
MORNING.
SATURDAY...IMPROVMENT WILL BE SLOW TO OCCUR ON SATURDAY AS THE LOW
LEVEL MOISTURE HANGS ON IN THE EASTERLY FLOW. WINDS WILL START TO
SHIFT TO THE WEST-SOUTHWEST AND WE EXPECT CEILINGS AND VISIBILITIES
TO RISE BY MID TO LATE MORNING, WITH THE POTENTIAL TO GO VFR BY MID
TO LATE AFTERNOON ACROSS THE TERMINALS.
OUTLOOK...
SATURDAY NIGHT...A BAND OF SHOWERS ARRIVES LATE AT NIGHT WITH A
COLD FRONT, DROPPING CONDITIONS BELOW VFR. SOUTHWESTERLY WINDS
MAINLY LESS THAN 10 KNOTS.
SUNDAY...BRIEF MVFR CONDITIONS IN THE MORNING WITH SOME SHOWERS AS A
COLD FRONT MOVES THROUGH, OTHERWISE VFR. WEST TO NORTHWEST WINDS
INCREASE TO 12-18 KNOTS WITH GUSTS TO 25 KNOTS, THEN DIMINISH AT
NIGHT.
MONDAY AND TUESDAY...VFR, THEN POSSIBLY SOME MVFR DURING TUESDAY
WITH A CHANCE OF SHOWERS AS A WARM FRONT MOVES THROUGH. WESTERLY
WINDS AROUND 10 KNOTS MONDAY, BECOMING LIGHT AT NIGHT THEN SHIFTING
TO SOUTHERLY TUESDAY.
&&
.MARINE...
WE HAVE UPGRADED THE SMALL CRAFT ADVISORY ON OUR NORTHERN TWO
OCEAN ZONES TO A GALE WARNING THROUGH THIS AFTERNOON. GALE FORCE
GUSTS ARE EXPECTED TO OCCUR OVER THE NEXT SEVERAL HOURS AND THEN
SHOULD TAPER OFF AS WE HEAD INTO THE LATE AFTERNOON AND EVENING.
SCA CONTINUES OCEAN WATERS THROUGH TONIGHT, ESPECIALLY DUE TO
SEAS.
FOG MAY BECOME A MARINE HAZARD LATER THIS FRIDAY NIGHT.
OUTLOOK...
SATURDAY...THE WINDS ARE ANTICIPATED TO BE LIGHT AS A CLOSED LOW
INITIALLY OVERHEAD WEAKENS AND THEN SHIFTS EASTWARD. THE SEAS MAY BE
RIGHT AT 5 FEET TO START ESPECIALLY ACROSS THE NORTHERN WATERS BUT
OVERALL THE CONDITIONS SHOULD BE TRENDING BELOW ADVISORY CRITERIA.
THEREFORE WE DID NOT EXTEND THE ADVISORY ATTM.
SUNDAY...WEST TO NORTHWEST WINDS TURN GUSTY TO AROUND 20 KNOTS WITH
SEAS AT OR BELOW 4 FEET. IT IS POSSIBLE WINDS GUST TO 25 KNOTS
NEARSHORE, HOWEVER OVERALL CONDITIONS ARE ANTICIPATED TO BE BELOW
ADVISORY CRITERIA.
MONDAY AND TUESDAY...SUB-ADVISORY CONDITIONS ARE ANTICIPATED DESPITE
SOME INCREASE IN A SOUTHERLY WIND MONDAY AND THEN AGAIN LATER
TUESDAY.
&&
.TIDES/COASTAL FLOODING...
PLEASE SEE THE HAZARD CFW STATEMENT FOR THE PARTICULARS RELATING
TO EACH AREA.
PHL: TIDAL DE ADVY EXPIRED BUT MAY NEED A NEW ONE TO BE ISSUED
THIS AFTERNOON FOR THE EARLY SATURDAY MORNING HIGH TIDE CYCLE.
CONFIDENCE IN EXCEEDING THE ADVY THRESHOLD WAS NOT QUITE
CATEGORICAL ON THIS SHIFT.
REEDY POINT UPPER DE BAY, LOWER TIDAL DE LINKED: REISSUED FOR LATE
THIS EVENING, SINCE CONFIDENCE IS CATEGORICAL THAT IT WILL REOCCUR,
ESPECIALLY BECAUSE THE FUNNELED ENE FLOW THIS MORNING TURNS LIGHT
SOUTH THIS EVENING.
NJ/DE ATLC COASTS: NO CHANGE IN THE PREVIOUS WARNING. THE TIDAL
SURGE IS EXPECTED TO STAY AROUND 1 TO 1.5 FEET TODAY IN THE
CONTINUING NORTHEASTERLY FLOW. THE THURSDAY EVENING HIGH TIDE SAW
MANY OBSERVING SITES EITHER JUST REACH OR FALL JUST SHY OF
MODERATE FLOODING THRESHOLDS. WE ARE FORECASTING MINOR TIDAL
FLOODING AROUND THIS MORNING`S HIGH TIDE AND MODERATE FLOODING
AROUND THIS FRIDAY EVENING`S HIGH TIDE. RATHER THAN CARRY MULTIPLE
HEADLINES, WE CONTINUED WITH THE COASTAL FLOOD WARNING TO COVER
BOTH HIGH TIDE CYCLES. MINOR TIDAL FLOODING MAY LINGER WITH THE
HIGH TIDE CYCLES ON SATURDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR NJZ012>014-
020>027.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SATURDAY FOR NJZ016.
DE...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR DEZ002>004.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
SATURDAY FOR DEZ001.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ452>455.
GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR ANZ450-451.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG/MEOLA
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...GORSE/MEOLA
MARINE...DRAG/GORSE/MEOLA
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
212 PM EDT FRI MAY 6 2016
.UPDATE...
ISSUED AT 125 PM EDT FRI MAY 6 2016
POPS FOR THE EASTERN COUNTIES OVER THE NEXT COUPLE OF HOURS WERE
INCREASED BASED ON RADAR TRENDS. OTHERWISE...NO OTHER CHANGES
WERE NEEDED AT THIS TIME.
UPDATE ISSUED AT 1140 AM EDT FRI MAY 6 2016
A COUPLE OF QUICK UPDATES HAVE BEEN DONE TO FINE TUNE THE HOURLY
GRIDS BASED ON OBSERVATIONS AND NEAR TERM MODEL TRENDS. POPS WERE
INCREASED SLIGHTLY FOR THIS AFTERNOON EAST OF A SANDY HOOK TO
JACKSON TO HARLAN LINE FOR BETTER AGREEMENT WITH SHORT TERM MODEL
GUIDANCE...CU DEVELOPMENT AND TRENDS. THE BEST CHANCES FOR ANY
SHOWERS WILL BE IN THE BIG SANDY REGION.
UPDATE ISSUED AT 635 AM EDT FRI MAY 6 2016
JUST A QUICK UPDATE TO FINE TUNE THE GRIDS PER THE LATEST OBS AND
TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 405 AM EDT FRI MAY 6 2016
07Z SFC ANALYSIS SHOWS LOW PRESSURE OFF TO THE EAST OF THE
APPALACHIANS. WHILE HIGH PRESSURE IS FOUND TO THE SOUTHWEST. A FEW
LINGERING LIGHT SHOWERS ARE DRIFTING SOUTH THROUGH FAR EASTERN
KENTUCKY FROM THAT EASTERN LOW. IN CONJUNCTION WITH THIS...LOW
AND MID LEVEL CLOUDS ARE FOUND CLOSER TO THE VIRGINIA AND WEST
VIRGINIA BORDER. IN THE CLEARING TO THE WEST OF THE BORDER
AREAS...PATCHY FOG IS NOTED IN THE SOME OF THE OBSERVATIONS.
TEMPERATURES ARE RUNNING IN THE LOW TO MID 40S ACROSS THE AREA
WITH DEWPOINTS NOT FAR AWAY...WHILE WINDS ARE GENERALLY LIGHT
FROM THE NORTHWEST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A CONUS OMEGA BLOCK
SHIFTING EAST AND OPENING UP DURING THE NEXT 48 HOURS. A DEEP
CLOSED LOW DESCENDING THROUGH THE SOUTHERN APPALACHIANS THIS
MORNING WILL PIVOT TO THE NORTHEAST BY EVENING BEFORE BEING PICKED
UP BY THE NORTHERN STREAM FLOW AND DEPARTING OFF THE MID ATLANTIC
COAST SATURDAY EVENING. IN ITS WAKE...RISING HEIGHTS AND RIDGING
WILL SPREAD FROM THE SOUTHERN PLAINS AND ACROSS THE MISSISSIPPI
VALLEY TOWARD KENTUCKY. HOWEVER...IN ASSOCIATION WITH A HUDSON BAY
UPPER LOW DESCENDING INTO THE GREAT LAKES...A MINOR WAVE WILL
SQUEEZE BY EASTERN KENTUCKY TO THE NORTH LATE SATURDAY. GIVEN THE
MODEL AGREEMENT HAVE FOLLOWED A GENERAL BLEND WITH A STRONG LEAN
TOWARD THE HRRR EARLY ON AND THE NAM12 THEREAFTER.
SENSIBLE WEATHER WILL FEATURE A MILDER DAY THAN YESTERDAY AS SOME
SUNSHINE RETURNS AND THE COLD AIR DEPARTS TO THE EAST. ISOLATED TO
SCATTERED SHOWERS WILL BE FOUND OVER FAR EASTERN KENTUCKY THROUGH
THE AFTERNOON. FOR TONIGHT...EXPECT A SMALL RIDGE TO VALLEY SPLIT
TO SET UP AHEAD OF A DEVELOPING WARM FRONT WITH PATCHY VALLEY FOG
AROUND...SIMILAR TO THIS MORNING. A FEW LIGHT SHOWERS CANNOT BE
RULED OUT WITH THAT BOUNDARY THROUGH THE MORNING...ESPECIALLY EAST
BY MIDDAY SATURDAY. A COLD FRONT WILL THEN SETTLE SOUTH TOWARD
EASTERN KENTUCKY LATER SATURDAY. BETWEEN THESE FEATURES...OUR AREA
WILL BE IN THE WARM SECTOR OF A QUICK MOVING SFC LOW AND AS A
RESULT COULD SEE SOME CONVECTION DEVELOP WITH FAVORABLE PARAMETERS
FOR STRONG TO SEVERE STORMS BUILDING DURING THE AFTERNOON AND
INTO THE EVENING. SPECIFICALLY...CAPE WILL BE MODERATE WITH LOW
LIS AND VEERING/INCREASING WINDS WITH HEIGHT. WILL HIGHLIGHT THIS
FURTHER IN THE FORTHCOMING HWO WITH HAIL AND GUSTY WINDS THE MAIN
THREAT.
USED THE SHORTBLEND/SUPERBLEND AS A STARTING POINT FOR MOST
ELEMENTS WITH SOME MINOR ADJUSTMENTS TO THE AFTERNOON DEWPOINTS
AND SOME TERRAIN DIFFERENCES FOR TEMPERATURES TONIGHT. DID ADJUST
POPS TO BE A BIT ABOVE THE POPULATION SCHEME...IN THE EAST THROUGH
TODAY AND ALSO FOR THE STRONG/SEVERE STORM CONCERNS ON SATURDAY
AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 405 AM EDT FRI MAY 6 2016
THE EXTENDED PORTION OF THE FORECAST BEGINS SATURDAY NIGHT WITH AN
ACTIVE PATTERN IN PLACE. UPPER CLOSED LOW OVER THE SOUTHEASTERN
CANADA REGION WILL BE IN PLACE THROUGH THE WEEKEND AS IT SLOWLY
SHIFTS EAST INTO THE COMING WEEK. THIS FEATURE CONTINUES TO SWING A
FEW SHORTWAVES INTO THE LOWER GREAT LAKES REGION THROUGH THE START
OF THE NEW WEEK. MEANWHILE...AS A WEAKENING RIDGE OVER THE SOUTHEAST
CONTINUES TO WEAKEN AND SHIFT EAST AS WELL WITH ANOTHER UPPER LEVEL
LOW OVER THE CENTRAL PLAINS. THIS FEATURE OPENS AND EJECTS EAST INTO
THE OHIO VALLEY BY MID WEEK. FOLLOWING THIS...TOWARDS THE END OF THE
EXTENDED PERIOD...THE PATTERN BECOMES MORE AMPLIFIED AS ANOTHER
UPPER LOW MOVES INTO THE UPPER PLAINS WITH A WEAKENING RIDGE OVER
THE OH VALLEY SHIFTING. OVERALL...BOTH THE GFS AND EURO HAVE A
DECENT HANDLE ON THE UPPER LEVEL PATTERN THROUGH NEXT WEEK. THOUGH
THE GFS IS A BIT MORE DRIER THAN THE EURO...THE BOTTOM LINE IS THAT
THE EXTENDED SEEMS QUITE WET AND ACTIVE. THIS SOLUTION IS ALSO
CONFIRMED BY THE ALL MODEL BLEND AS WELL KEEPING THE CHANCE OF
PRECIP THROUGH JUST ABOUT EVERY DAY OF THE EXTENDED.
NEAR THE SURFACE HEADING INTO SATURDAY NIGHT AND SUNDAY...A SURFACE
LOW PRESSURE SYSTEM DEVELOPING UP OVER THE CENTRAL PLAINS SETS UP A
WARM FRONT INTO THE MIDWEST AND A QUASI STATIONARY BOUNDARY INTO
THE OH VALLEY. THIS BOUNDARY BECOMES A FOCUS FOR CONTINUED
CONVECTION SATURDAY NIGHT AND SUNDAY. IN FACT...THE EURO MIGHT
SUGGEST AN MCS SET UP FOR THIS TIME PERIOD. INSTABILITY AND SHEAR
SEEM SUBSTANTIAL FOR ORGANIZED CONVECTION AT LEAST EARLY IN THE
SATURDAY NIGHT PERIOD AND AGAIN SUNDAY AFTERNOON FOCUSING ON MAX
HEATING. STRONG CAPPING HEADING INTO THE DAY MONDAY WOULD LIMIT
CONVECTION A BIT MORE AS THE MENTIONED BOUNDARY LIFTS NORTH. STILL
WILL KEEP LOW CHANCE POPS IN THE NORTH CLOSER TO THE BOUNDARY.
TUESDAY...THE SYSTEM OUT WEST SHIFTS EAST WITH STRONG UPPER LEVEL
SUPPORT. STRONG CONVECTION SEEMS TO DEVELOP AHEAD OF THE COLD FRONT
TUESDAY AFTERNOON INTO TUESDAY NIGHT. THIS WILL KEEP LIKELY POPS IN
THE FORECAST THROUGH WEDNESDAY AS GFS MODEL SOUNDINGS KEEP GOOD
INSTABILITY IN PLACE TUESDAY AND WEDNESDAY AFTERNOON. IN FACT...THIS
SYSTEM WILL BE FOLLOWED BY A DISTURBANCE TO MOVE INTO THE AREA ON
THURSDAY. MODELS HIGHLIGHT AN ACTIVE EXTENDED FORECAST THROUGH NEXT
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 212 PM EDT FRI MAY 6 2016
CU AND ISOLATED TO SCATTERED SHOWERS HAVE DEVELOPED ACROSS THE
EASTERN PARTS OF THE REGION GENERALLY SOUTH AND EAST OF JKL AND
NEAR SJS UNDER THE INFLUENCE OF A DEPARTING UPPER LEVEL LOW. VCSH
HAS BEEN INCLUDED FOR SJS AND JKL FOR THE NEXT FEW HOURS. BRIEF
MVFR IS POSSIBLE IN LOCATIONS THAT RECEIVE A DIRECT HIT FROM A
SHOWER. OTHERWISE...NORTHERLY WINDS AT NEAR 10KT WITH SOME GUSTS
AS HIGH AS 20KT ARE EXPECTED THROUGH SUNSET AT THE TAF SITES WITH
CU OR STRATOCU IN THE VFR RANGE. WINDS SHOULD THEN SLACKEN...ALTHOUGH
THEY COULD BECOME GUSTY LATE IN THE PERIOD...AROUND 15Z...MAINLY
AT SYM...LOZ...AND SME. VALLEY FOG SHOULD AGAIN FORM AND MAY
LIMIT VIS TO IFR RANGE BETWEEN 4Z AND 13Z IN SOME AREAS...BUT IS
NOT EXPECTED AT THE TAF SITES. A DISTURBANCE WILL BRING INCREASE
MID LEVEL CLOUDS AFTER 8Z AND CIGS DOWN NEAR 5KFT WILL BE POSSIBLE
ALONG WITH A STRAY SHOWER. FOR THE MOST PART THOUGH...VFR SHOULD
PREVAIL THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...JP
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
302 PM CDT FRI MAY 6 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 301 PM CDT FRI MAY 6 2016
TONIGHT AND SATURDAY...ISOLATED SHOWERS ARE DEVELOPING IN THE
PANHANDLE...MOVING EAST...AS FORECAST BY THE HRRR MODEL. THIS
ACTIVITY SHOULD MOVE EAST NORTHEAST THIS EVENING AND POSE A WIND
GUST THREAT. THEY ARE IN THE WARM SECTOR. OTHER ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOP ALONG THE COLD FRONT DROPPING THROUGH THE
SOUTH DAKOTA. THIS ACTIVITY MAY COALESCE ACROSS NRN NEB TONIGHT BUT
THE NAM IS SHOWING MUCH LESS STORM COVERAGE THAN YESTERDAYS MODEL
RUN. THUS...LESS STORM COVERAGE WILL HOLD UP THE PROGRESS OF THE
COLD FRONT WHICH WILL BECOME STATIONARY ACROSS THE SWRN NEB AND
BECOME THE FOCUS FOR SEVERE WEATHER SATURDAY AFTN.
THIS IS FARTHER NORTH AND THE GFS SHOWS THE SAME PLACING MORE OF
WESTERN AND NCNTL NEB IN SEVERE WEATHER POTENTIAL. CONRAD SUGGESTS
DOMINANT RIGHT MOVING SUPER CELLS AT THE ONSET. SHEAR WEAKENS IN THE
LATE EVENING AND A MULTICELLS REGIME TAKES HOLD. 0-1KM HELICITY
INCREASE IN THE EARLY EVENING SUGGESTING AN ISOLATED TORNADO THREAT.
THE LATEST MODEL BLEND PLUS BIAS CORRECTION SHOWS DEW POINTS IN THE
LOWER 50S ALONG I-80 SATURDAY AFTERNOON WHILE THE MET GUIDANCE SHOWS
MID 50S. NONE OF THESE NUMBERS SUGGEST A SHALLOW MIXING HEIGHT BUT
GIVEN THE FRONT AND HIGH HELICITY AN ISOLATED TORNADO MAY DEVELOP.
THIS WOULD BE THE FIRST OF TWO ROUNDS OF CONVECTION.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 301 PM CDT FRI MAY 6 2016
SATURDAY NIGHT THROUGH MONDAY...STORM COVERAGE BECOMES MORE NUMEROUS
SATURDAY EVENING AS THE 700MB WARM FRONT LIFTS THROUGH THE FORECAST
AREA. A SECOND ROUND OF CONVECTION IS INDICATED IN THE NAM MODEL
LIFTING VERY QUICKLY THROUGH THE FCST AREA.
THE LATEST MODEL CONSENSUS HAS A CLOSED H700MB LOW ACROSS ERN
WY/NERN COLO SUNDAY MORNING AT 12Z. THIS LOW MOVES VERY SLOWLY INTO
THE PANHANDLE SUNDAY. THE NAM SHOWS INSTABILITY LIFTING NORTH INTO
NCNTL NEB SUNDAY AFTN. THE ATM SHOULD BECOME SUFFICIENTLY UNSTABLE
ALONG AND EAST OF HIGHWAY 183 FOR STORM DEVELOPMENT. THE STORM MODE
IS UNCERTAIN AT THIS TIME.
THERE IS A LARGE SPREAD IN MODEL SOLNS FOR MONDAY BUT SOME SORT OF
UPPER LEVEL LOW SHOULD STILL BE LOCATED SOMEWHERE ACROSS NEBRASKA OR
WRN IA/MN...NWRN KS OR SRN SD. THIS SHOULD PRODUCE A LIKELY CHANCE
FOR SHOWERS AND THUNDERSTORMS MONDAY...MAINLY EAST CLOSER TO THE
WARM SECTOR.
THERE IS NO REAL CHANGE IN THE TEMPERATURE FORECAST. THE FRONT IS
FARTHER NORTH SATURDAY SUPPORTING HIGHS IN THE 70S ACROSS SWRN NEB.
HIGHS IN THE 60S ARE EXPECTED SUNDAY AND MONDAY WITH LOWS IN THE
40S.
MONDAY NIGHT THROUGH FRIDAY...A SECOND UPPER LEVEL LOW WILL MOVE
INTO THE DAKOTAS TUESDAY AND MOVE SLOWLY INTO THE UPPER MIDWEST BY
THURSDAY MORNING. UPPER LEVEL HEIGHTS AMPLIFY ACROSS WRN N AMERICA
SUPPORTING A FRESH SHOT OF CANADIAN HIGH PRESSURE. RAIN CHANCES
DECREASE TO ISOLATED WEDNESDAY AND BEYOND. THE MODELS CONTINUE TO
SHOW COLD AIR ALOFT WITH TEMPERATURES AT H500MB AROUND -18C AND
H700MB TEMPERATURES FALL TO 0C OR COLDER. THE ECM SHOWS H500MB
TEMPERATURES FALLING TO -25C THURSDAY MORNING.
BIAS CORRECTION ADDED TO THE MAX AND MIN TEMPERATURES PRODUCED
TEMPERATURES SEVERAL DEGREES COLDER AND FROST MAY DEVELOP ACROSS THE
WRN SANDHILLS AND EASTERN PANHANDLE. SKIES WOULD NEED TO CLEAR TO
SUPPORT RADIATIONAL COOLING. LOWS IN THE 30S AND 40S ARE EXPECTED
WEDNESDAY THROUGH FRIDAY. HIGHS RISE INTO THE 60S TO NEAR 70.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1221 PM CDT FRI MAY 6 2016
VFR IS GENERALLY EXPECTED THIS AFTERNOON THROUGH SATURDAY MORNING.
ISOLATED SHOWERS AND THUNDERSTORMS CAPABLE OF GUSTY WINDS ARE
INDICATED BY THE RAP AND HRRR MODELS THIS EVENING. THIS ACTIVITY
IS EXPECTED TO DIMINISH BY 06Z. THE LATEST NAM MODEL RUN SHOWS
MUCH LESS STORM COVERAGE. THUS ISOLATED STORM COVERAGE IS ALL THAT
IS EXPECTED LATE TONIGHT AND SATURDAY MORNING.
&&
.HYDROLOGY...
ISSUED AT 301 PM CDT FRI MAY 6 2016
A FLOOD ADVISORY WITH MINOR FLOODING TO CONTINUE ALONG THE NORTH
PLATTE RIVER NEAR LEWELLEN. THE CURRENT STAGE AT LEWELLEN IS 7.7
FEET WHICH IS JUST OVER THE FLOOD STAGE OF 7.5 FEET. A SLOW RISE TO
7.9 FEET IS EXPECTED OVER THE NEXT SEVERAL DAYS. ELEVATED RIVER
LEVELS WILL CONTINUE UPSTREAM AT LISCO. ALONG THE SOUTH PLATTE RIVER
ELEVATED FLOWS WILL ALSO CONTINUE FOR THE NEXT SEVERAL DAYS. AT THIS
TIME...THE SOUTH PLATTE AND MAIN STEM PLATTE RIVER FROM ROSCOE TO
BRADY IS EXPECTED TO REMAIN BELOW FLOOD STAGE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...CDC
HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1224 PM CDT FRI MAY 6 2016
.SYNOPSIS...
ISSUED AT 344 AM CDT FRI MAY 6 2016
A HIGHLY AMPLIFIED H5 PATTERN CONTINUES ACROSS THE CONUS
TONIGHT. UA ANALYSIS FROM EARLIER THIS EVENING HAD A RIDGE OF HIGH
PRESSURE EXTENDING FROM EASTERN NEW MEXICO...NORTH TO SRN
SASKATCHEWAN. CLOSED LOWS WERE PRESENT ON EITHER SIDE OF THE RIDGE.
THE FIRST LOW WAS LOCATED OVER THE CAROLINAS...WHILE THE SECOND WAS
OFF THE COAST OF CENTRAL CALIFORNIA. AT THE SURFACE...HIGH PRESSURE
WAS LOCATED OVER THE OZARKS WHILE A COLD FRONT EXTENDED FROM FAR
NWRN NORTH DAKOTA INTO CENTRAL MONTANA. BETWEEN THE APPG FRONT AND
NORTHWEST OF THE SURFACE HIGH...SRLY WINDS WERE PRESENT ACORSS
WESTERN AND NORTH CENTRAL NEBRASKA TONIGHT. WITH SRLY WINDS OF 10 TO
20 MPH ATTM...TEMPERATURES AS OF 3 AM CDT WERE VERY MILD ACROSS THE
FORECAST AREA. READINGS RANGED FROM 56 AT OGALLALA AND
IMPERIAL...TO 63 AT VALENTINE...AINSWORTH AND THEDFORD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM CDT FRI MAY 6 2016
OVER THE NEXT 24 HOURS...THE MAIN FORECAST CHALLENGS
ARE TEMPERATURES TODAY...FOLLOWED BY THE THREAT FOR THUNDERSTORMS IN
THE WEST AND NORTHWEST TONIGHT. FOR TODAY...THE COLD
FRONT...CURRENTLY PUSHING INTO NORTHERN NORTH DAKOTA...WILL MIGRATE
SOUTH INTO CENTRAL SOUTH DAKOTA BY THIS AFTERNOON...IMMEDIATELY
SOUTH OF THIS FEATURE...H85 TEMPS WILL REACH 22 TO 25C ACROSS FAR
NORTHWESTERN NEBRASKA AND SOUTHWESTERN SOUTH DAKOTA. TEMPS TODAY
WILL BE WARMEST ACROSS THE FAR SOUTHWESTERN CWA WHERE H85 TEMPS
REACH 24 TO 26C THIS AFTERNOON. ANOTHER AREA OF WARM TEMPS WILL BE
ACROSS FAR NORTHWESTERN AND NORTH CENTRAL NEBRASKA INVOF THE APPG
COLD FRONT. IN THESE AREAS I WENT ABOVE GUIDANCE ON TEMPS AS WE
TYPICALLY ARE WARMER WITH AN APPROACHING COLD FROPA...IE
COMPRESSIONAL WARMING. AS FOR THUNDERSTORM CHANCES LATER
TODAY...HAVE LEFT OUT MENTION OF PCPN IN THE FCST. LOOKING AT THE
NAM SOLN FOR THIS AFTERNOON...YEILDED SOME DECENT ELEVATED
INSTABILITY IN THE WEST AND SOUTHWESTERN CWA. HOWEVER...THE CAP IS
REALLY STRONG THIS AFTERNOON AND DOESN/T WEAKEN UNTIL LATER THIS
EVENING. WITH THIS IN MIND...WILL CONTINUE A DRY FCST THROUGH 00Z
SAT. FOR TONIGHT...THUNDERSTORM CHANCES WILL BEGIN TO INCREASE LATER
THIS EVENING AS THE COLD FRONT BEGINS TO PUSH INTO NORTHERN
NEBRASKA. THE MODELS CONTINUE TO DEVELOP SOME WEAK CONVECTION ALONG
AND NORTH OF THE FRONT OVERNIGHT AND HAVE PLACED MY HIGHEST POPS
ACROSS THE NORTHERN HALF OF THE CWA WHERE THE FRONT IS EXPECTED TO
BE LOCATED TONIGHT. FURTHER SOUTH...ELEVATED INSTABILITY WILL
CONTINUE OVERNIGHT...HOWEVER THERE IS NOT MUCH OF ANY LOW LEVEL
FOCUS FOR CONVECTIVE INITIATION. WITH THIS IN MIND...HAVE LIMITED
POPS TO SLIGHTS IN THE SOUTH OVERNIGHT AS THE 4KM WRF AND GFS SOLNS
HAVE SOME INDICATION OF ISOLATED STORMS LATE TONIGHT IN THE EASTERN
PANHANDLE AND SWRN NEBRASKA. THE SEVERE THREAT TONIGHT WILL BE
RATHER LIMITED AND CONFINED TO FAR NORTHWESTERN PORTIONS OF THE CWA.
DEEP LAYER SHEAR WILL BE ON THE ORDER OF 15 TO 25 KTS THIS
AFTERNOON...INCREASING TO 30 TO 40 KTS TONIGHT. MID LEVEL LAPSE
RATES CONTINUE TO BE STEEP OVERNIGHT...SO THERE IS THAT CONTINUED
THREAT FOR LARGE HAIL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 344 AM CDT FRI MAY 6 2016
MODELS HAVE SHIFTED THE POTENTIAL FOR SEVERE TSTMS BACK NORTHWARD
INTO SOUTHWEST NEBRASKA SATURDAY AFTERNOON AND EVENING. GFS AND HI
RES MODELS ...NAM 4KM...NAM...ARW AND NMM ALL AGREE THAT SFC LOW
PRESSURE WILL QUICKLY DEEPEN ACROSS NORTHEAST COLORADO DURING THE
DAY IN RESPONSE TO A SIGNIFICANT SHORTWAVE ROUNDING THE BASE OF THE
UPPER LEVEL LOW AND EMERGING INTO EASTERN COLORADO SATURDAY
AFTERNOON AT PEAK HEATING. A WARM FRONT WILL BE LOCATED EAST OF THE
SFC LOW ALONG A LINE FROM NEAR IMPERIAL TO CURTIS AND THEN FARTHER
EAST INTO SOUTH CENTRAL NEBRASKA...WHILE A DRY LINE WILL ARC SOUTH
FROM THE SFC LOW FROM FAR NORTHEAST COLORADO THROUGH EXTREME WESTERN
KANSAS. THIS WILL SET UP A TRIPLE POINT IN THE VICINITY OF FAR
NORTHEAST COLORADO OR FAR SOUTHWEST NEBRASKA. IT APPEARS THAT
CONVECTION WILL INITIATE NEAR THE TRIPLE POINT BY LATE AFTERNOON
SATURDAY...WITH OTHER SCT STORMS DEVELOPING SOUTHWARD ALONG THE DRY
LINE. THE STORMS NEAR THE TRIPLE POINT SHOULD QUICKLY EXPAND EAST
AND NORTHEAST ALONG AND NORTH OF THE WARM FRONT ACROSS SOUTHWEST
NEBRASKA SATURDAY EVENING. POINT SOUNDINGS IN THIS AREA SHOW
CONDITIONS QUITE UNSTABLE DUE TO ADEQUATE POOLED MOISTURE /DEW
POINTS NEARING 60F/ STEEP MID LEVEL LAPSE RATES AND SFC TEMPS IN THE
UPPER 60S TO LOWER 70S. WIND PROFILES IN THE SOUNDINGS SUPPORT
SUPERCELLS WITH ALL MODES OF SEVERE POSSIBLE INCLUDING LARGE HAIL
AND POSSIBLY A TORNADO OR TWO. THIS SITUATION WILL BE MONITORED
CLOSELY AS THE POSITION OF THE SFC LOW AND ASSOCIATED BOUNDARIES
WILL BE KEY TO WHERE THE BEST SEVERE POTENTIAL WILL RESIDE.
FORECAST CONFIDENCE REGARDING THE POTENTIAL FOR SEVERE WEATHER IS
LOW FOR SUNDAY. BOUNDARY LOCATION ETC. WILL LIKELY DEPEND ON
SATURDAY NIGHT NIGHT CONVECTION. SEEMS REASONABLE THAT AN MCS WILL
LIKELY HAVE MOVED ACROSS MOST OF THE AREA TO THE NORTH OF THE WARM
FRONT SATURDAY NIGHT...AND THIS COULD VERY WELL PUSH THE FRONTAL
BOUNDARY AND CORRESPONDING SEVERE THREAT FARTHER SOUTH IN KS SUNDAY
AFTERNOON. HOWEVER...THE UPPER LEVEL LOW IS FORECAST TO SLOWLY CROSS
THE AREA SUNDAY AFTERNOON THROUGH MONDAY. AT THE VERY LEAST EXPECT A
SCATTERING OF SHOWERS AND TSTMS SUNDAY THROUGH MONDAY...WITH LATER
FORECASTS TO DETERMINE THE LOCATION FOR ANY SEVERE TSTM ACTIVITY.
TUESDAY AND BEYOND WILL REMAIN SOMEWHAT UNSETTLED AS ANOTHER UPPER
LOW DEVELOPS INTO THE NORTHERN PLAINS. MODELS ARE CONVERGING ON A
NORTHERN TRACK WITH THIS NEXT SYSTEM...WITH A MORE WESTERLY DRYING
FLOW ALOFT ON THE SOUTH SIDE OF THE SYSTEM ACROSS OUR AREA. POPS
HAVE TRENDED DOWN TO JUST SLIGHT CHANCE FOR MIDWEEK DUE TO THE
FARTHER NORTH TRACK. IT WILL REMAIN COOL FOR MUCH OF THE WEEK...AS A
PACIFIC AIRMASS WILL GRADUALLY MIX WITH A CANADIAN AIRMASS MOVING
SOUTH ON THE BACKSIDE OF THE NORTHERN PLAINS UPPER LEVEL LOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1221 PM CDT FRI MAY 6 2016
VFR IS GENERALLY EXPECTED THIS AFTERNOON THROUGH SATRUDAY MORNING.
ISOLATED SHOWERS AND THUNDERSTORMS CAPABLE OF GUSTY WINDS ARE
INDICATED BY THE RAP AND HRRR MODELS THIS EVENING. THIS ACTIVITY
IS EXPECTED TO DIMINISH BY 06Z. THE LATEST NAM MODEL RUN SHOWS
MUCH LESS STORM COVERAGE. THUS ISOLATED STORM COVERAGE IS ALL THAT
IS EXPECTED LATE TONIGHT AND SATURDAY MORNING.
&&
.HYDROLOGY...
ISSUED AT 344 AM CDT FRI MAY 6 2016
MINOR FLOODING CONTINUES ALONG THE NORTH PLATTE RIVER NEAR
LEWELLEN. THE CURRENT STAGE AT LEWELLEN IS 7.6 FEET WHICH IS JUST
OVER THE FLOOD STAGE OF 7.5 FEET. LITTLE CHANGE IN THE RIVER LEVEL
IS EXPECTED OVER THE NEXT SEVERAL DAYS. ELEVATED RIVER LEVELS WILL
CONTINUE ALONG THE SOUTH PLATTE RIVER AND THE MAIN STEM OF THE
PLATTE RIVER DOWNSTREAM OF NORTH PLATTE FOR THE NEXT SEVERAL DAYS.
AT THIS TIME...THE SOUTH PLATTE AND MAIN STEM PLATTE RIVER FROM
NORTH PLATTE TO BRADY IS EXPECTED TO REMAIN BELOW FLOOD STAGE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...BUTTLER
LONG TERM...TAYLOR
AVIATION...CDC
HYDROLOGY...BUTTLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1218 PM CDT FRI MAY 6 2016
.UPDATE...
ISSUED AT 558 AM CDT FRI MAY 6 2016
ISOLATED THUNDERSTORMS HAVE EXPANDED A LITTLE IN COVERAGE ACROSS
SOUTHEAST SOUTH DAKOTA...AND MAY CLIP KNOX/CEDAR COUNTIES EARLY
THIS MORNING. NO MODEL HAD A REAL HANDLE ON THIS...WITH MOST
RECENT RUNS OF THE OPERATIONAL HRRR FINALLY CATCHING ON BY 09Z.
NOTHING MORE THAN A PASSING SPRINKLE...MAYBE WITH A RUMBLE OF THUNDER.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 252 AM CDT FRI MAY 6 2016
QUIET AND VERY WARM WEATHER TODAY...THEN MORE ACTIVE AND WET
WEATHER SATURDAY AND SUNDAY.
UPPER RIDGE REMAINS FIRM ACROSS THE WESTERN HIGH PLAINS WITH
CLOSED LOWS ACROSS BOTH COASTS. THIS RESULTS IN ONE MORE DRY DAY
WITH BREEZY SOUTHERLY WINDS DEVELOPING TODAY WITH MOSTLY SUNNY
SKIES. GUIDANCE REMAINS VERY WARM TODAY WITH HIGHS PROBABLY
REACHING THE LOWER TO MID 80S. THIS WILL RESULT IN AFTERNOON
HUMIDITY DROPPING INTO THE UPPER 20S TO LOWER 30S...BUT STILL TOO
HIGH FOR ANY RED FLAG FIRE CONCERNS. THESE HIGHS ARE ALSO WELL
BELOW ANY MAX TEMP RECORDS TODAY WHICH RANGE FROM 95 TO 101.
THERE IS A COLD FRONT MOVING OUT OF THE NORTHERN ROCKIES...AND
WILL CONTINUE TO BE PUSHED BY AN UPPER TROUGH MOVING THROUGH
CENTRAL CANADA. THIS FRONT SETTLES SOUTHWARD INTO THE FORECAST
AREA TOWARD I80 THROUGH DAYBREAK SATURDAY. THIS COULD RESULT IN A
SLIGHT CHANCE OF THUNDERSTORMS GENERALLY ALONG/NORTH OF IT AFTER
MIDNIGHT. PRECIP COULD VERY WELL EVEN REMAIN JUST NORTH OF THE
AREA TONIGHT ACROSS SOUTHERN SOUTH DAKOTA.
SATURDAY...THE FRONT SETTLES A LITTLE FURTHER SOUTH BUT NOT MUCH.
THIS SETS UP A PRETTY TIGHT TEMPERATURE GRADIENT FROM SOUTH TO
NORTH. HIGHS NORTH OF THE FRONT IN THE MID 60S...BUT NEAR 80 ALONG
THE KS/NE BORDER. THERE COULD BE ISOLATED REMNANTS FROM ANY
CONVECTION NORTH OF THE BOUNDARY SATURDAY MORNING. BUT...AGAIN IT
COULD ALSO BE DRY AS UPPER RIDGING REMAINS IN PLACE...WITH NO
SIGNIFICANT FORCING OTHERWISE. WITH THE FRONT BECOMING STATIONARY
ACROSS SOUTHERN NEBRASKA SATURDAY AFTERNOON...INSTABILITY DOES
BUILD NEAR IT. A WEAK CAP MAY HOLD WITH CONVECTION DEVELOPING
FURTHER WEST ACROSS THE WESTERN HIGH PLAINS. WILL MAINTAIN A
SLIGHT CHANCE OF THUNDERSTORMS SATURDAY AFTERNOON...BUT MOST AREAS
WILL PROBABLY REMAIN DRY. IF A STORM WOULD DEVELOP...THERE IS JUST
A MARGINAL RISK THAT IT COULD BE SEVERE.
SATURDAY NIGHT NIGHT...ELEVATED CONVECTION MAY DEVELOP NORTH OF
THE SURFACE FRONT AS DEPICTED BY VARIOUS MODELS. HOWEVER...THE NAM
IS ALSO HINTING THAT A WEAK PIECE OF ENERGY EJECTING FROM THE MAIN
LOW ACROSS THE CENTRAL ROCKIES MAY BE ENOUGH TO TRIGGER SCATTERED
SHOWERS AND THUNDERSTORMS. THUS WILL MAINTAIN CHANCE POPS SATURDAY
NIGHT.
SUNDAY IS TRICKY AS MODEL ARE NOT IN GOOD AGREEMENT ON PLACEMENT
OF CONVECTION THROUGH THE DAY. THERE COULD BE LINGERING ACTIVITY
EARLY SUNDAY MORNING. STRONGER STORMS COULD DEVELOP SUNDAY AFTERNOON
AS LOW LEVEL MOISTURE CONTINUES TO BUILD WITH DEWPOINTS RISING
INTO THE MID TO UPPER 50S AND POSSIBLY EVEN LOWER 60S. ANY MORNING
CONVECTION COULD HAVE IMPLICATIONS ON AFTERNOON DEVELOPMENT...
THUS CONFIDENCE IS LOW OF THE DETAILS AT THIS POINT.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 252 AM CDT FRI MAY 6 2016
PRECIP CHANCE SUBSTANTIALLY INCREASE SUNDAY NIGHT AS UPPER LOW
BEGINS TO MOVE ONTO THE PLAINS AND FRONTAL BOUNDARY SHIFTS
NORTHWARD ACROSS THE FORECAST AREA. WILL HAVE TO WATCH FOR SEVERE
STORMS SUNDAY EVENING...AND MAYBE EVEN OVERNIGHT AS ELEVATED
STORMS WILL STILL BE POSSIBLE. ONE HALF TO ONE AND ONE HALF INCHES
OF RAIN WILL ALSO BE POSSIBLE SUNDAY NIGHT ACROSS THE REGION. PW
VALUES INCREASE TO ABOUT 1.5 STANDARD DEVIATIONS ABOVE NORMAL
BASED ON NAEFS CLIMATOLOGY DURING THIS TIME.
THUNDERSTORM CHANCES REMAIN IN THE LIKELY CATEGORY THROUGH MONDAY
AS SURFACE LOW/FRONTAL BOUNDARY REMAIN IN THE REGION. COULD ALSO
BE A SEVERE RISK ON MONDAY AS WELL...WITH PRECIP THREAT CONTINUING
INTO MONDAY NIGHT AS THE FRONT SHIFTS EASTWARD.
TUESDAY WILL MAINTAIN A SMALL CHANCE OF SHOWERS/ISOLATED
STORMS BASED ON OLDER MODEL BLENDS...BUT REALLY THE NEWER MODELS
ARE SHOWING IT COULD BE DRY AS WE ARE BETWEEN SYSTEMS. ANOTHER
WEAK WAVE COULD MOVE INTO THE AREA ON WEDNESDAY WHICH MAY BRING
ONE MORE SMALL CHANCE OF SHOWERS/ISOLATED STORMS...WITH DRY
WEATHER THURSDAY.
&&
.AVIATION...(18Z TAFS FOR KOMA...KLNK...KOFK THROUGH 18Z SATURDAY)
ISSUED AT 1210 PM CDT FRI MAY 6 2016
GUSTY SWLY WINDS HAVE DEVELOPED EARLY THIS AFTERNOON WITH THE
ONSET OF DEEPER BOUNDARY-LAYER MIXING. A GRADUAL WEAKENING AND
BACKING OF THE WINDS WILL OCCUR THIS EVENING AS THE BOUNDARY LAYER
DECOUPLES. A COLD FRONT PRESENTLY FROM THE ND-MN RED RIVER VALLEY
TO E-CNTRL WY WILL CONTINUE SWD...REACHING KOFK LATE TONIGHT AND
KOMA AND KLNK BEFORE NOON SATURDAY. SURFACE WINDS WILL TRANSITION
FROM SLY TO NELY OR ELY WITH THE FRONTAL PASSAGE. A MODEST WLY
NOCTURNAL LLJ IS ALSO EXPECTED TO DEVELOP TONIGHT ACROSS PORTIONS
OF E-CNTRL AND SERN NE...WITH THE POTENTIAL FOR LLWS THROUGH
SUNRISE SATURDAY AT KOMA AND KLNK. VFR CIGS/VSBYS WILL PREVAIL
THROUGH THE TAF PERIOD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DEWALD
SHORT TERM...DEWALD
LONG TERM...DEWALD
AVIATION...MEAD
AREA FORECAST DISCUSSION
NWS MEDFORD OR
314 PM PDT FRI MAY 6 2016
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT...
HIGH CLOUDS FROM CONVECTION ACROSS NEVADA THIS MORNING HAVE
OVERSPREAD MUCH OF THE AREA THIS AFTERNOON. WHILE THIS HAS LIMITED
SURFACE HEATING SOME TODAY, SOME SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED ACROSS PORTIONS OF LAKE, MODOC, AND SISKIYOU COUNTIES.
THUS FAR, SOME ONE HOUR RAINFALL AMOUNTS OF 0.20 TO 0.30" HAVE
BEEN OBSERVED WITH THESE CELLS IN MODOC AND SISKIYOU COUNTIES.
WITH STORMS MOVING SOUTHWEST AROUND 30 MPH SOME GUSTY WINDS ARE
POSSIBLE. HOWEVER, AT THIS TIME NONE OF THE ACTIVITY IS
THREATENING TO REACH SEVERE THRESHOLDS OVER THE NEXT HOUR.
WHAT APPEARS TO A BIT OF A CONCERN AS WE HEAD THROUGH THE
AFTERNOON INTO THE EVENING IS THE POSSIBILITY OF TRAINING SHOWER
AND THUNDERSTORM ACTIVITY ACROSS SOME OF THESE SAME AREAS. ALSO,
EXTENSIVE HEAVIER SHOWERS AND THUNDERSTORMS ACROSS NORTHERN
NEVADA ARE LIKELY TO BRING AN EXTENSIVE AREA OF RAINFALL ACROSS
THE SOUTHEAST SIDE THIS EVENING, PROBABLY IN EXCESS OF A HALF OF AN
INCH ACROSS MUCH OF MODOC COUNTY. THUS, THE PRIMARY CONCERN
THROUGH THIS EVENING WILL BE URBAN AND SMALL STREAM FLOODING,
POSSIBLE FLOODING ON AND NEAR BURN SCAR AREAS FROM RECENT YEARS,
AND, SHOULD THIS HEAVY RAIN STALL OVER SNOWPACK AREAS, MORE
EXTENSIVE FLOODING WILL BE POSSIBLE. WHILE SEVERE WIND AND HAIL IS
STILL A THREAT THROUGH THE EVENING SUSPECT IT WILL BE ISOLATED AT
MOST DUE TO THE FACT THAT SHORTWAVE ENERGY AND SURFACE DYNAMICS
TO SUPPORT IT ARE FAIRLY WEAK. 500MB TEMPERATURES ARE GENERALLY
WARMING THIS AFTERNOON AND EVENING. HAVE USED THE HRRR FOR MANY
OF THE FORECAST REFINEMENTS TODAY, BUT HAVE ALSO ADJUSTED THAT AS
OBSERVED CONDITIONS ARE A BIT DIFFERENT.
FOR THE WEST SIDE THERE IS STILL SOME THREAT OF SHOWERS AND
ISOLATED THUNDERSTORMS, ALBEIT LESS THAN THE EAST SIDE AND
NORTHERN CALIFORNIA, AS THE DYNAMICS ARE NOT AS FAVORABLE.
TONIGHT THROUGH SATURDAY SHOWER AND THUNDERSTORM ACTIVITY WILL
WEAKEN AND THEN RE-FIRE AGAIN. HOWEVER, INSTABILITY IS LESSER
TOMORROW AS THE UPPER LEVEL LOW WILL BE FURTHER SOUTH AND EAST.
THIS WILL BE PARTIALLY COUNTERACTED BY INCREASED SURFACE HEATING
DUE TO LESS CLOUD COVER. WHILE MOST GUIDANCE KEEPS SHOWERS AND
STORMS EAST OF THE CASCADES, THE SREF AND NAM12 DO SUPPORT SOME
POTENTIAL ALONG AND NEAR THE CASCADES. LOCALIZED HEAVY RAINFALL
WILL STILL BE OF SOME CONCERN AS PWATS WILL BE 0.75" TO JUST OVER
1 INCH- SIMILAR TO TODAY. BTL
.LONG TERM...SUNDAY THROUGH FRIDAY...
THE UPPER LOW WILL CONTINUE TO SLOWLY MOVE INTO THE FOUR CORNERS
SUNDAY MORNING AND AN UPPER RIDGE WILL NOSE IN FROM THE WEST, BUT
THEN WILL RETREAT WESTWARD SUNDAY AFTERNOON AS A SHORTWAVE MOVES
SOUTHEAST INTO EASTERN WASHINGTON. AT THE SURFACE A WEAK FRONT
WILL MOVE THROUGH THE NORTHWEST PART OF THE REGION EARLY SUNDAY
MORNING INCREASING THE ONSHORE FLOW. THE MARINE LATER COULD
THICKEN ENOUGH TO WARRANT A SLIGHT CHANCE OF LIGHT RAIN OR DRIZZLE
MAINLY NORTH OF THE UMPQUA DIVIDE. COULD NOT RULE OUT A SLIGHT
CHANCE IN PARTS OF THE ILLINOIS VALLEY, GRANTS PASS AND THE NORTH
END OF THE ROGUE VALLEY. ELSEWHERE IT WILL REMAIN DRY. ANOTHER
SHORTWAVE WILL MOVE INTO EASTERN WASHINGTON AND NORTHEAST OREGON
ON MONDAY, BUT THE TRACK IS NOT FAVORABLE FOR PRECIPITATION, SO IT
WILL REMAIN DRY. AN UPPER RIDGE WILL BUILD OFF THE COAST TUESDAY
WITH A THERMAL TROUGH DEVELOPING AT THE COAST. THE MODELS DIFFER
WITH THE DETAILS AFTER TUESDAY, BUT CONDITIONS ARE EXPECTED TO
REMAIN DRY WITH ABOVE NORMAL TEMPERATURES IN THE AFTERNOON.
THEREFORE, FORECAST HIGH TEMPERATURES WERE INCREASED FOR THE
TUESDAY THROUGH THURSDAY TIME PERIOD. THE MODELS SHOW AN UPPER LOW
MOVING TOWARDS THE CALIFORNIA COAST LATE NEXT WEEK WHICH COULD
BRING INCREASING MOISTURE AND INSTABILITY, BUT IT`S STILL A WAYS
OUT AND THE DETAILS ARE LIKELY TO CHANGE. FOR NOW WE`LL KEEP IT
DRY WITH ABOVE NORMAL TEMPERATURES. -PETRUCELLI
&&
.AVIATION...FOR THE 06/18Z TAF CYCLE...THE MAIN CONCERN INTO THIS
EVENING WILL BE ISOLATED TO SCATTERED THUNDERSTORMS. ANY STORMS WILL
BE CAPABLE OF PRODUCING MVFR AND OCCASIONAL IFR CIGS, VERY HEAVY
RAIN, SMALL HAIL AND GUSTY OUTFLOW WINDS. SHOWERS AND
THUNDERSTORMS WILL START OUT ISOLATED EARLY THIS AFTERNOON, THEN
WILL BECOME MORE NUMEROUS FROM LATE THIS AFTERNOON INTO THIS
EVENING WITH A GENERAL MOVEMENT FROM EAST TO WEST, THEN NORTHEAST
TO SOUTHWEST TOWARDS THIS EVENING. THE GREATEST THREAT FOR
THUNDERSTORMS IS FROM THE CASCADES/SISKIYOUS EAST, BUT STORMS MAY
ADVANCE AS FAR WEST AS JACKSON COUNTY (INCLUDING KMFR) LATE THIS
AFTERNOON. SHOWERS AND STORMS DIMINISH LATE THIS EVENING WITH VFR
CONDITIONS EXPECTED, EXCEPT FOR THE COAST WHERE MVFR AND LOCAL IFR
CIGS WILL DEVELOP EARLY THIS EVENING AND CONTINUE INTO SATURDAY
MORNING. -PETRUCELLI
&&
.MARINE...UPDATED 500 AM PDT FRI 6 MAY 2016...FEW CHANGES WERE MADE
TO THE MARINE FORECAST THIS MORNING. NORTH WINDS WILL INCREASE AGAIN
THIS AFTERNOON AND CONTINUE INTO THE EVENING. THIS TREND OF STRONG
NORTH WINDS/STEEP SEAS IN THE AFTERNOON/EVENINGS AND LULLS AT NIGHT
WILL LIKELY CONTINUE THROUGH THE WEEKEND. A GALE WARNING REMAINS IN
EFFECT THROUGH THIS EVENING OVER THE SOUTHERN WATERS WITH SMALL
CRAFT ADVISORIES ELSEWHERE. MODELS HAVE MAINTAINED THE POTENTIAL FOR
GALES OVER THE WEEKEND AND GALE WATCHES REMAIN IN EFFECT. THESE WILL
LIKELY BE UPGRADED LATER TODAY. -WRIGHT
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FLASH FLOOD WATCH UNTIL 11 PM PDT THIS EVENING FOR ORZ030-031.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR ORZ022.
CA...FLASH FLOOD WATCH UNTIL 11 PM PDT THIS EVENING FOR CAZ080>085.
PACIFIC COASTAL WATERS...
- SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
PZZ350-356-370-376.
- SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR PZZ350-356-370.
- GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ356-376.
- GALE WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING FOR
PZZ376.
$$
BTL/MAP/DW
AREA FORECAST DISCUSSION
NWS MEDFORD OR
1059 AM PDT FRI MAY 6 2016
.UPDATE...
AN UPDATE TO THE FORECAST HAS BEEN MADE AND SENT FOR CONDITIONS
THROUGH THIS EVENING. ADJUSTMENTS WERE MADE TO SKY COVERAGE,
PROBABILITY OF PRECIPITATION, PRECIPITATION AMOUNTS, SHOWER AND
THUNDERSTORM COVERAGE, AND LIGHTNING ACTIVITY LEVEL.
&&
.DISCUSSION...
LOW PRESSURE CENTERED OVER CALIFORNIA AND NEVADA THIS MORNING IS
SENDING INVERTED TROUGHS ACROSS THE FORECAST AREA FROM EAST TO
WEST TODAY. PRIMARY FOCUS FOR SHOWER AND THUNDERSTORM ACTIVITY
WILL BE ACROSS MODOC, LAKE, SISKIYOU, AND KLAMATH COUNTIES THIS
AFTERNOON AND EVENING. SOME ACTIVITY IS LIKELY TO REACH TO THE
SOUTHEASTERN PORTION OF THE WEST SIDE LATE THIS AFTERNOON AND,
MORE LIKELY, THIS EVENING FROM ABOUT CRATER LAKE NATIONAL PARK
SOUTHWESTWARD TO THE BEAR CREEK PORTION OF THE ROGUE VALLEY,
OREGON CAVES, AND THE LOWER KLAMATH RIVER VALLEY. FLASH FLOOD
WATCHES REMAIN IN EFFECT FOR PORTIONS OF THE EAST SIDE AND
NORTHERN CALIFORNIA FOR THIS AFTERNOON THROUGH THIS EVENING. BTL
&&
.AVIATION...FOR THE 06/12Z TAF CYCLE...A MIX OF MVFR AND VFR
CONDITIONS WILL CONTINUE THROUGH LATE MORNING. SHOWERS AND
THUNDERSTORMS WILL DEVELOP ACROSS THE EAST SIDE EARLY THIS AFTERNOON
AND THEN MOVE FROM EAST TO WEST ACROSS THE AREA. THE GREATEST THREAT
FOR THUNDERSTORMS IS FROM THE CASCADES/SISKIYOUS EAST, BUT STORMS MAY
ADVANCE AS FAR WEST AS JACKSON/JOSEPHINE COUNTY (INCLUDING KMFR) LATE
THIS AFTERNOON. ANY STORMS WILL BE CAPABLE OF PRODUCING IFR
CIGS/VIS, VERY HEAVY RAIN, SMALL HAIL, AND GUSTY WINDS. SHOWERS AND
STORMS DIMINISH LATE THIS EVENING. -WRIGHT
&&
.MARINE...UPDATED 500 AM PDT FRI 6 MAY 2016...FEW CHANGES WERE MADE
TO THE MARINE FORECAST THIS MORNING. NORTH WINDS WILL INCREASE AGAIN
THIS AFTERNOON AND CONTINUE INTO THE EVENING. THIS TREND OF STRONG
NORTH WINDS/STEEP SEAS IN THE AFTERNOON/EVENINGS AND LULLS AT NIGHT
WILL LIKELY CONTINUE THROUGH THE WEEKEND. A GALE WARNING REMAINS IN
EFFECT THROUGH THIS EVENING OVER THE SOUTHERN WATERS WITH SMALL
CRAFT ADVISORIES ELSEWHERE. MODELS HAVE MAINTAINED THE POTENTIAL FOR
GALES OVER THE WEEKEND AND GALE WATCHES REMAIN IN EFFECT. THESE WILL
LIKELY BE UPGRADED LATER TODAY. -WRIGHT
&&
.PREV DISCUSSION... /ISSUED 339 AM PDT FRI MAY 6 2016/
DISCUSSION...A MOIST AND UNSTABLE AIR MASS CONTINUES OVER MUCH OF
THE FORECAST AREA TODAY...AND WILL HELP GENERATE ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS...PRIMARILY FOCUSED OVER NORTHERN
CALIFORNIA AND FROM THE CASCADES EASTWARD. THE CUTOFF LOW THAT
DOESN`T QUIT REMAINS OVER SOUTHERN CALIFORNIA...SLOWLY MOVING TO
THE EAST AND FEEDING THE AREA WITH DEEP MOISTURE AND DISTURBANCES
FROM THE SOUTHEAST.
THE INTERSECTION OF DEEP MOISTURE...INSTABILITY...AND FAVORABLE
DYNAMICS WILL BE MOST PROMINENT IN EASTERN
SISKIYOU...MODOC...AND LAKE COUNTIES TODAY. THE WRF ARW AND NMM
SHOW STORMS AND HEAVY RAINFALL FROM MOUNT SHASTA EASTWARD TO
ALTURAS AND NORTHEAST TO LAKEVIEW THIS AFTERNOON AND EVENING AS
SHORTWAVE ENERGY MOVES IN FROM THE EAST PER THE NAM AND SREF MODEL
OUTPUT. THE LATEST HRRR OUTPUT IS SUGGESTING SIMILAR. GIVEN
CURRENT SNOW DEPTH OVER THE WARNER MOUNTAINS OF 62 INCHES PER
DISMAL SWAMP SNOTEL...AND FORECAST SNOW LEVELS OF 9500 FEET...THIS
DEFINITELY PROVIDES THE POTENTIAL FOR RAPID SNOW MELT AND FLASH
FLOODING. A FLASH FLOOD WATCH CONTINUES FOR THE SOUTHERN HALF OF
SISKIYOU COUNTY...MODOC...EXTREME EASTERN KLAMATH...AND MOST OF
LAKE COUNTY. PRECIPITABLE WATER VALUES IN THE TOP 10 PERCENT FOR
THIS TIME OF YEAR ALSO SUPPORT THE FFA AREA. THE WESTERN FRINGES
OF THIS HAZARD AREA ARE LESS LIKELY TO SEE ANY HEAVY RAIN PROBLEMS
BUT HAVE LEFT THE AREA INTACT FROM THE PREVIOUS ISSUANCE GIVEN THE
UNCERTAINTY OF EXACT HEAVY RAIN LOCATIONS...AND WITH LATEST HRRR
OUTPUT LINING UP PRETTY NICELY WITH THE HAZARD AREA.
ADDITIONALLY...THE STORM PREDICTION CENTER HAS MAINTAINED A MARGINAL
RISK FOR SEVERE STORMS OVER MODOC AND SOUTHERN LAKE COUNTIES.
EASTERN SISKIYOU COUNTY ALSO FEATURES A CHANCE FOR SEVERE
THUNDERSTORMS WITH FORECAST MOST UNSTABLE CAPES OF 2000+ J/KG, LI
VALUES -4 TO -6, AND 0-6KM BULK SHEAR VALUES OF 30+KT. STRONG
WINDS, HAIL, AND HEAVY RAIN ARE ALL A POSSIBILITY TODAY. LATEST
SATELLITE IMAGERY SHOWS THAT THE DAY SHOULD START OUT SUNNY IN MANY
PLACES EAST OF THE CASCADES...WHICH WILL YIELD UNINHIBITED SURFACE
HEATING AND POTENTIALLY MAX OUT THE INSTABILITY THIS AFTERNOON.
INSTABILITY DIMINISHES TONIGHT AND SHOWERS AND THUNDERSTORMS FOLLOW
SUIT. ON SATURDAY A DRYING AIR MASS WEST OF THE CASCADES WILL YIELD
SUNNY AND WARM CONDITIONS WHILE THUNDERSTORMS REMAIN POSSIBLE IN
MODOC COUNTY. TEMPERATURES WILL BE ABOUT 10 DEGREES ABOVE NORMAL
WEST OF THE CASCADES. BY SUNDAY COOL AND DRY NORTHWEST FLOW ALOFT
ELIMINATES THE CHANCE FOR SHOWERS OVER THE VAST MAJORITY OF THE
FORECAST AREA...WHILE A DEEPENING MARINE LAYER COULD BRING DRIZZLE
TO THE COAST.
ON MONDAY A WARM TREND BEGINS THAT WILL LAST INTO THE MIDDLE OF THE
WEEK AT LEAST...WITH TEMPERATURES MONDAY EXPECTED TO BE A FEW
DEGREES ABOVE NORMAL. A PORTION OF THE PREVIOUS LONG-TERM
DISCUSSION FOLLOWS.
TUESDAY THROUGH THURSDAY...AN UPPER RIDGE WILL BUILD OFF THE
COAST TUESDAY WITH A THERMAL TROUGH DEVELOPING AT THE COAST. THE
MODELS DIFFER WITH THE DETAILS AFTER TUESDAY, BUT THE PATTERN
REMAINS FAVORABLE FOR CONTINUED DRY AND WARM CONDITIONS.
-PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FLASH FLOOD WATCH THROUGH THIS EVENING FOR ORZ030-031.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR ORZ022.
CA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CAZ080>085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THIS
EVENING FOR PZZ350-356-370.
GALE WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ356-376.
GALE WATCH FROM SATURDAY MORNING THROUGH SUNDAY EVENING FOR
PZZ376.
$$
BTL/NSK/TRW
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
607 PM EDT FRI MAY 6 2016
.SYNOPSIS...
SHOWERS REMAIN IN THE FORECAST THROUGH SATURDAY. MOTHERS DAY LOOKS
MAINLY DRY FOLLOWED BY A MODEST WARMING TREND INTO EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
MAIN BAND OF RAIN SHOWERS MOVING THROUGH MUCH OF CENTRAL PA ATTM.
SHOWERS WILL PERSIST THROUGH THE EARLY EVE HOURS BEFORE TAPERING
OFF TO DRIZZLE MOST PLACES. DRIZZLE ALONG WITH AREAS OF FOG AND
LOW CLOUDS WILL PERSIST OVERNIGHT AS SFC LOW PULLS AWAY FROM THE
REGION.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
THE UPPER LOW WILL DRIFT NWD AND HOVER OVER THE EASTERN HALF OF
THE STATE TONIGHT BEFORE FILLING AND GETTING KICKED OUT TO SEA BY
AN ANOMALOUS TROUGH MOVING IN FROM THE WNW ON SAT. THERE MIGHT BE
A LULL IN THE PRECIP ON SAT IN BETWEEN THE SYSTEMS.
THE UPSTREAM TROUGH WILL MANAGE TO NUDGE SOME SEASONABLY MILD AIR
IN FROM THE SW. MAXES SHOULD BE IN THE 60S AREAWIDE. THIS SHOULD
HELP GENERATE SOME INSTABILITY AND CAPE...ALLOWING CONVECTION TO
FORM ALONG AND JUST IN ADVANCE OF THE LOW/FRONT. WILL JUST MENTION
SOME TS IN THE LATE AFTN IN THE W AND CARRY IT INTO THE CENTRAL
MTNS FOR THE FIRST PART OF SAT NIGHT BEFORE THE FRONT PUSHES THRU.
AGAIN...MOISTURE STILL LACKING AND THE WESTERLY FLOW AHEAD OF THE
FRONT WILL KEEP THE RAINFALL TO A RELATIVE MINIMUM. LITTLE/NO RISK
FOR BOTH SEVERE AND FLOODING. THE 8H TEMPS FROM 10-12C DOWN TO
AROUND A FEW DEGS EITHER SIDE OF 0C BY SUNDAY MORNING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
SFC COLD FRONT WILL PUSH SE ACROSS THE STATE EARLY SUNDAY...
ACCOMPANIED BY A FEW SCATTERED SHOWERS. MODERATELY STRONG LLVL
PRESSURE GRADIENT AND COLD ADVECTION WILL BRING GUSTY NW WINDS
(PEAK GUSTS OF 25-30 MPH DURING THE LATE MORNING AND AFTERNOON
HOURS) WITH PARTLY TO MOSTLY SUNNY SKIES.
SFC RIDGE AXIS WITH LOW PWAT AIR SLIDES OVER THE STATE LATER
SUNDAY NIGHT WITH CLEAR TOO PARTLY CLOUDY SKIES AND CHILLY LOW
TEMPS EARLY MONDAY - IN THE 30S AND 40S. PATCHY LIGHT FROST IS
POSSIBLE ACROSS THE NRN MTNS 05-12Z MONDAY.
THE SFC RIDGE WILL SLIDE TO OUR EAST BY MONDAY NIGHT AS HEIGHTS
SLOWLY BEGIN TO RISE ALOFT. THIS WILL HELP TO FORM/ADVECT A WARM
FRONT NE FROM THE OHIO VALLEY TO CENTRAL PA BY TUESDAY AFTERNOON.
ISOLATED TO SCATTERED SHOWERS ARE EXPECTED TO DEVELOP MONDAY
AFTERNOON AND EVENING ACROSS MAINLY THE WRN MTNS OF THE
STATE...AND WILL PERSIST AT ABOUT THE SAME AREAL COVERAGE INTO
TUESDAY MORNING. CHC FOR SHOWERS (AND SCATTERED TSRA) INCREASES
TUESDAY AFTERNOON AND NIGHT AS SWRLY LLJ TRANSPORTS BETTER
MOISTURE INTO THE REGION...AND UPPER LEVEL DIVERGENCE STRENGTHENS.
CHC FOR PRECIP IN THE FORM OF SHOWERS AND SCATTERED TSRA WILL PEAK
DURING THE MIDWEEK PERIOD...BEFORE THE SFC FRONT BEGINS TO OCCLUDE
AND WEAKEN AS THE UPPER FLOW TURNS MORE ZONAL.
LATER NEXT WEEK AND OVER NEXT WEEKEND...NRN STREAM ENERGY WITH
DIFFICULT TO TIME JETLETS TO ITS SOUTH WILL BRING LOW CHCS FOR
MAINLY AFTERNOON SHOWERS AND ISOLATED TSRA. TEMPS WILL START OUT
A FEW TO SEVERAL DEG F BELOW NORMAL SUNDAY INTO MONDAY...THEN
GRADUALLY MODERATE TO NEAR OR SLIGHTLY ABOVE NORMAL DURING THE
MID-WEEK PERIOD AS THE SOUTHERN STREAM WAVE PUSHES THE
AFOREMENTIONED WARM INTO...OR JUST NORTH OF THE REGION.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
LOW PRES OVR THE DELMARVA PENINSULA WILL WEAKEN
OVERNIGHT...CAUSING RAIN TO TAPER OFF ACROSS MOST OF CENTRAL PA.
HOWEVER...STRATUS DECK WILL REMAIN IN PLACE AND CIGS SHOULD FALL
OVERNIGHT AS BLYR COOLS. VFR CIG STILL NOTED AT KBFD AS OF
22Z...BUT MDL SOUNDINGS SUPPORT A DROP TO MVFR BY 00Z. BOTH SREF
AND LATEST HRRR SUGGEST IFR CIGS ARE LIKELY LATE TONIGHT AT
KMDT/KLNS...POSSIBLE AT KBFD/KJST/KUNV AND UNLIKELY AT KIPT.
REMNANTS OF LOW PRES WILL PUSH OUT TO SEA AND RESIDUAL STRATUS
DECK WILL LIKELY LIFT/BREAK UP BY AFTN DUE TO DIURNAL
HEATING/MIXING. BOTH MOS AND SREF SUPPORT THE IDEA OF WIDESPREAD
VFR CONDS BY SAT AFTN. A COLD FRONT WILL SWEEP INTO THE REGION SAT
EVENING...ACCOMPANIED BY SCT SHRA AND POSSIBLE BRIEF VIS
REDUCTIONS...MAINLY OVER THE WESTERN HALF OF THE STATE.
OUTLOOK...SATURDAY-TUESDAY
SUN-MON...VFR/NO SIG WX EXPECTED.
TUE-WED...CHC OF SHOWERS/MVFR PSBL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/GARTNER
NEAR TERM...GARTNER
SHORT TERM...DANGELO/GARTNER
LONG TERM...LAMBERT/STEINBUGL
AVIATION...FITZGERALD/GARTNER
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
306 PM CDT FRI MAY 6 2016
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 306 PM CDT FRI MAY 6 2016
WEAK SHORT WAVE AND ATTENDANT SURFACE COLD FRONT WILL MOVING
SOUTHWARD ACROSS THE FORECAST AREA TONIGHT. PRECIP CHANCES ARE A
TOUGH CALL WITH THIS SYSTEM. BOTH THE NAM AND GFS HUMIDITY TIME
SECTIONS AND SOUNDINGS SHOW VERY LITTLE IN THE WAY OF LOW LEVEL
MOISTURE BELOW ABOUT 750MB...WITH OBVIOUSLY WELL MIXED CONDITIONS
AHEAD OF THE BOUNDARY THIS AFTERNOON ADDING TO THE DRYNESS. THE
FORCING WITH THE SHORT WAVE IS NOT OVERLY IMPRESSIVE...BUT THIS
EVENING THERE IS A FAIR AMOUNT OF PURE ELEVATED INSTABILITY. THE
WIND SHEAR IS RATHER WEAK HOWEVER...NOTED WITH 30 KNOTS AT 925MB AND
ONLY 5 TO 10 KNOTS AT 700MB. INTERESTINGLY...THE HRRR CONTINUES TO
DEVELOP CONVECTION LATE THIS AFTERNOON AND EARLY EVENING ALONG THE I
90 AND HIGHWAY 14 CORRIDORS. THE HIGHWAY 14 CONVECTION WOULD BE
ASSOCIATED WITH LOW LEVEL CONVERGENCE ALONG THE COLD FRONT. HOWEVER
THE I 90 CONVECTION IS WELL AHEAD OF THE FRONT. AM SKEPTICAL ABOUT
THE I 90 CONVECTION DEVELOPING SO EARLY...AS IT IS LIKELY KEYING OFF
OF THE CONVECTIVE TEMPERATURE. INDEED...THE HRRR IS TRYING TO SHOW
CONVECTION DEVELOPING RIGHT NOW IN SOUTH CENTRAL SD AND THERE IS
NOTHING THERE. IT IS THAT CONVECTION WHICH IT THEN EXTENDS EASTWARD
ALONG I 90. SO FOR NOW ADDED ONLY VERY LOW POPS TO THE I 90 CORRIDOR
VERY LATE THIS AFTERNOON AND EARLY EVENING TO ACCOUNT FOR THE
HRRR SCENARIO...AND KEPT THE HIGHER SCATTERED POPS IN OUR NORTHERN
ZONES CLOSER TO THE ACTUAL FRONT. CHANCE OR SCATTERED POPS SHOULD
THEN DRIFT SOUTHWARD THROUGH THE NIGHT...BUT AGAIN CHANCES ARE
FAIRLY SKITTISH AT ANY GIVEN POINT LOCATION THAT YOU WILL ACTUALLY
GET WET. IN ADDITION...STABILITY INCREASES AFTER MIDNIGHT TO THE
POINT WHERE BY SATURDAY...THERE IS LITTLE IN THE WAY OF INSTABILITY
LEFT IN OUR SOUTHERN ZONES WHERE SMALL POPS LINGER UNDER A MID DECK
OF CLOUDS.
FOR TEMPERATURES...LATEST LOWS ARE LITTLE CHANGED FROM PREVIOUS
RUNS...WITH UPPER 40S IN OUR FAR NORTHERN ZONES...TO NEAR 55 IN
SIOUX CITY AND STORM LAKE IA. HIGHS SATURDAY WILL BE COOLER...
WITH READINGS IN THE UPPER 60S TO AROUND 70.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 306 PM CDT FRI MAY 6 2016
SATURDAY NIGHT INTO SUNDAY WILL SEE LOW PRESSURE ALOFT DEVELOP
ACROSS THE CENTRAL ROCKIES AS HIGH PRESSURE AT THE SURFACE SETTLES
INTO THE NORTHERN PLAINS. THIS SHOULD ALLOW FOR MAINLY DRY
CONDITIONS DURING THIS TIME. THERE WILL BE A CHANCE FOR
SHOWERS CLOSER TO THE MISSOURI RIVER CORRIDOR CLOSER TO THE MID LEVEL
MOISTURE...BUT CHANCES NOT REAL HIGH. EASTERLY FLOW WILL ALLOW
COOLER AIR TO FILTER IN BUT BE OFFSET A BIT BY CLOUD COVER AT NIGHT.
LOWS SHOULD MAINLY BE IN THE 40S...CLOSER TO 40 ALONG HIGHWAY 14 AND
CLOSER TO 50 ALONG THE MISSOURI RIVER. HIGHS ON SUNDAY...WITH THE
THICKER CLOUDS CLOSER TO THE MISSOURI RIVER SHOULD BE CLOSER TO THE
MID 60S...WITH LOWER 70S POSSIBLE CLOSER TO HIGHWAY 14.
SUNDAY NIGHT INTO MONDAY DEEPER MOISTURE AND BETTER SUPPORT FOR
PRECIPITATION WILL SPREAD NORTH SO SUSPECT THAT THIS WILL BE THE
PERIOD OF TIME FOR THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS. AT
THIS TIME NOT ENOUGH SHEAR OR INSTABILITY TO BE CONCERNED ABOUT
SEVERE WEATHER BUT ENOUGH TO CONTINUE A MENTION OF THUNDERSTORMS.
DIURNAL RANGE NOT TOO WIDE WITH LOWS IN THE 50S SUNDAY NIGHT AND
HIGHS IN THE LOWER TO MID 60S ON MONDAY.
IN THE OUTER PERIODS(TUESDAY THROUGH FRIDAY)...DEEP TROUGHING IN THE
MIDDLE OF THE COUNTRY WILL SPELL COOL AND SHOWERY WEATHER THROUGH
THE PERIOD. WHILE OVERALL CONFIDENCE IN THE DEEPER TROUGH IS FAIRLY
HIGH...CONFIDENCE ON THE INDIVIDUAL PIECES OF ENERGY ARE LOWER THUS
THE CHANCES FOR PRECIPITATION WILL NOT BE ALL THAT HIGH. THERE
SHOULD BE A FEW PERIODS OF SHOWERS AND POSSIBLY THUNDERSTORMS DURING
THIS TIME JUST A PROBLEM OF TIMING. FOR NOW WILL LEAN TOWARDS ONLY A
SHOWERS MENTION AND START ADDING IN THE CHANCE FOR THUNDERSTORMS
WHEN CONFIDENCE INCREASES. AS FOR TEMPERATURES NOT TOO MUCH TO TALK
ABOUT...PRETTY MUCH HIGHS IN THE 60S AND LOWS IN THE 40S. OVERALL
NOT A REAL NICE PERIOD OF WEATHER FOR MID MAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1234 PM CDT FRI MAY 6 2016
VFR WILL PREVAIL TODAY AND TONIGHT. A COLD FRONT WILL MOVE
SOUTHWARD TONIGHT CAUSING A WIND SHIFT TO A NORTHERLY...THEN
NORTHEAST DIRECTION. THERE COULD BE SOME ISOLATED TSRA WITH THIS
FRONTAL PASSAGE...BUT AT THIS TIME WAS LEFT OUT OF THE TAF SITES
WITH THE CHANCES BEING TOO SPARSE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...08
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
352 PM EDT FRI MAY 6 2016
.SYNOPSIS...
COOL AND UNSETTLED WEATHER WILL CONTINUE ACROSS THE REGION
THROUGH THE WEEKEND WITH A CHANCE FOR SHOWERS AND THUNDERSTORMS.
WARMER AIR WILL START TO WORK INTO THE REGION WITH A WARMING TREND
AND MORE SEASONABLE TEMPERATURES THROUGH THE MIDDLE OF NEXT
WEEK...ALTHOUGH UNSETTLED CONDITIONS WILL CONTINUE OUR CHANCES FOR
SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
AS OF 345 PM EDT FRIDAY...
UPPER AND SFC LOW PRESENTLY NEAR VERTICALLY STACKED OVER THE
DELMARVA REGION. A SHORTWAVE ROUNDING THE EASTERN SIDE OF THE UPPER
LEVEL LOW IS SPARKING SOME SHOWERY ACTIVITY IN THE REGION.
THESE SHOWERS AND POSSIBLY AN ISOLATED THUNDERSTORM ARE EXPECTED
THROUGH THE AFTERNOON HOURS...WITH A LITTLE BIT BETTER ORGANIZED
ACTIVITY ROLLING THROUGH IN THE EARLY EVENING HOURS. TOTAL
RAINFALL AMOUNTS SHOULD GENERALLY BE SMALL BASED ON LATEST HRRR
WHICH SHOWS MAXIMUM AMOUNTS OF A TENTH TO QUARTER OF AN INCH.
DESPITE RECENT RAINS...ADDITIONAL AMOUNTS WILL NOT BE ENOUGH TO
CAUSE ANY FLOOD CONCERNS ASIDE FROM THE CURRENT AND FORECAST RIVER
FLOODING ALONG AND NEAR THE DAN RIVER.
GIVEN ABUNDANT GROUND MOISTURE...FOG COULD BECOME A CONCERN
THIS EVENING...THOUGH WINDS SHOULD STAY UP ENOUGH TO CAUSE ENOUGH
MIXING TO KEEP IT FROM BECOMING WIDESPREAD.
A STRENGTHENING PRESSURE GRADIENT BETWEEN THE PASSING LOW AND A
SECOND ONE MOVING THROUGH THE GREAT LAKES REGION WILL INDUCE SOME
STRONGER WINDS TOMORROW...HOWEVER NOTHING ABOVE 35 MPH ARE FORECAST.
AHEAD OF THE COLD FRONT ASSOCIATED WITH THE LOW...SHOWERS SHOULD FIRE
UP IN THE REGION...PARTICULARLY IN THE MOUNTAINS. AN ISOLATED
THUNDERSTORM CAN NOT BE RULED OUT DUE TO WEAK INSTABILITY AT THE
TIME THE FRONT APPROACHES THE REGION...BUT LITTLE MORE BEYOND A
RUMBLE OF THUNDER IS EXPECTED. AGAIN...EXPECTED ADDITIONAL RAINFALL
AMOUNTS WILL NOT BE ENOUGH TO CAUSE ANY FLOOD CONCERNS.
NIGHT TIME LOWS SHOULD BE SEASONAL IN THE MID TO HIGH 40S...AND
TOMORROWS HIGHS WILL BEGIN TO TREND BACK TOWARDS SEASONAL AND WILL
BE IN THE 60S AND 70S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 345 PM EDT FRIDAY...
THE UPPER LEVEL PATTERN WILL BE TRANSITIONING TO SOME SHALLOW RIDGING
AND EVENTUALLY SET UP SOUTHEASTERLY FLOW ALOFT...ALLOWING THE
MODERATING TREND TO CONTINUE IN TEMPERATURES. HOWEVER A FRONTAL
BOUNDARY WILL SETTLE INTO THE REGION ON SUNDAY AND LINGER OVER THE AREA
INTO THE FIRST PART OF NEXT WEEK. THIS WILL KEEP CONDITIONS UNSETTLED
WITH A CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE FORECAST. ALSO AS
THE FRONT INITIALLY MOVES INTO THE AREA FROM THE SATURDAY NIGHT THE LOW
LEVEL WIND FIELD WILL ENHANCE AND CREATE QUITE GUSTY CONDITIONS INTO
SUNDAY. HIGH TEMPERATURES BY MONDAY WILL BE AROUND 80 DEGREES EAST OF
THE BLUE RIDGE AND GENERALLY IN THE 70 TO 75 DEGREE RANGE TO THE
WEST.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...
THE UPPER PATTERN WILL REMAIN TRANSITORY AND TRANSITION FROM A SHALLOW
RIDGE TO A PROGRESSIVE QUASI ZONAL REGIME. THIS WILL ALLOW
SOUTHEASTERLY FLOW TO CONTINUE BRINGING MOISTURE INTO THE REGION WITH
AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH THE END OF
THE WORKWEEK. TEMPERATURES WILL REMAIN SEASONABLE WITH HIGHS IN THE
LOWER 80S EAST TO THE LOWER AND MIDDLE 70S WEST WITH A SLIGHT COOLDOWN
BY THE END OF THE WEEK.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
THE UPPER LEVEL LOW THAT CREATED POOR FLIGHT CONDITIONS FOR MUCH OF
THE PAST FEW DAYS IS FINALLY EXITING THE REGION TO THE EAST.
SHOWERY CONDITIONS WILL BEGIN TO FORM UP IN THE REGION THIS
AFTERNOON AT PEAK HEATING. BASED ON HRRR GUIDANCE...ROA/LYH/DAN WILL
SEE SOME OF THIS ACTIVITY IN THE AFTERNOON INTO THE EVENING HOWEVER
CONDITIONS LOOK TO REMAIN PRIMARILY VFR. OTHER LOCATIONS...CURRENTLY
FORECAST FOR VICINITY SHOWERS DUE TO LOWER CONFIDENCE.
FOG WAS CONSIDERED FOR THE OVERNIGHT HOURS BUT ENOUGH MIXING SHOULD
OCCUR TO ELIMINATE THAT THREAT. LYH AND DAN APPEAR TO BE AT MOST
THREAT BUT WAS LEFT OUT FOR NOW DUE TO LOW CONFIDENCE.
WINDS ARE CURRENTLY A BIT GUSTY AND PRIMARILY FROM THE NORTHWEST FOR
MUCH OF THE REGION. THESE SHOULD CALM DOWN WITH SUNSET BUT SHOULD
BEGIN AGAIN AROUND SUNRISE. LYH SHOULD BE SPARED FROM THIS DUE TO
TOPOGRAPHY.
EXTENDED DISCUSSION...
MAINLY VFR INTO SATURDAY BEFORE NEXT FRONT AND UPPER DISTURBANCE
ARRIVE SAT NIGHT-SUN WHICH COULD BRING SUB VFR WEATHER TO THE
AREA...MAINLY BCB/BLF/LWB.
MONDAY WILL BE MAINLY VFR WITH SOUTHWEST FLOW IN PLACE THOUGH WARM
FRONT MAY BRING SOME MVFR CIGS AND POSSIBLE SHOWERS TO THE
MOUNTAINS. WE WILL BE IN THE WARM SECTOR BY TUESDAY WITH ISOLATED
TO SCATTERED SHOWERS OR THUNDERSTORMS EXPECTED. SOME MVFR POSSIBLE
WITH THOSE OTHERWISE VFR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS/WP
NEAR TERM...JR/KK
SHORT TERM...MBS
LONG TERM...MBS
AVIATION...JR/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
132 PM EDT FRI MAY 6 2016
.SYNOPSIS...
UPPER LOW MOVES FROM THE NC/VA COAST THIS MORNING NORTH TO PA/NJ
BY SATURDAY MORNING. A COLD FRONT MOVES ACROSS THE AREA SATURDAY
NIGHT INTO SUNDAY...STALLING ACROSS THE CAROLINAS MONDAY THEN
MOVING NORTH AS A WARM FRONT BY TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 916 AM EDT FRIDAY...
THE UPPER LOW WILL CONTINUE TO LIFT NORTHEAST TODAY AND REACH THE
JERSEY SHORE ON SATURDAY MORNING. MODIFIED TEMPERATURES WITH
LATEST OBS AND LEANED LATE MORNING INTO THE AFTERNOON TOWARDS THE
LAV GUIDANCE. HIGH TEMPERATURES THIS AFTERNOON WILL RANGE FROM THE
UPPER 40S IN THE MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
DECREASED POPS FOR THIS MORNING WITH MORNING RADAR TRENDS AND
SHAPED LATE MORNING AND EARLY AFTERNOON POPS TOWARDS RNK WRFARW
SOLUTION. HAVE A GOOD DAY !
AS OF 730 AM EDT FRIDAY...
LOOKING AT MAINLY HIGHER POPS IN THE EAST THIS MORNING WITH
ISOLATED TO SCATTERED COVERAGE AT BEST WEST OF THE BLUE RIDGE.
SYSTEM OVER EASTERN VIRGINIA/NORTH CAROLINA SHOULD SHIFT NORTHWARD
TOWARD THE MID-ATLANTIC COAST OF MARYLAND AND NEW JERSEY THIS
AFTERNOON.
NO MAJOR CHANGES WITH THIS UPDATE.
PREVIOUS MORNING DISCUSSION...
UPPER LOW OVER EASTERN NORTH CAROLINA EARLY THIS MORNING WITH SFC
LOW EAST OF THE TIDEWATER OF VA WILL KEEP AN AXIS OF STEADIER
SHOWERS ACROSS THE PIEDMONT THIS MORNING INTO EARLY AFTERNOON WITH
MORE ISOLATED TO SCATTERED COVERAGE FURTHER WEST. ANOTHER
SHORTWAVE/VORT ROUNDING THE WEST SIDE OF THE UPPER LOW COMBINED WITH
NW FLOW IN THE LOW LVLS SHOULD ENHANCE SOME SHOWERS ACROSS THE WV
MTNS AS WELL...WITH THE LOWER THREAT OF SHOWERS ACROSS THE NC
FOOTHILLS. RAINFALL AMOUNTS PER MODELS/WPC SUGGEST ANOTHER ONE
QUARTER TO ONE HALF INCH IN THE EAST...WITH LOCALLY HIGHER AMOUNTS
IF DEEPER CONVECTION CAN GET GOING...WHILE THE WEST WILL SEE ANOTHER
QUARTER INCH OR LESS...WITH AGAIN HIGHER AMOUNTS MORE OVER SE WV
LATER TODAY.
AS FAR AS FLOOD CONCERNS GO...IT IS NOT ENOUGH TO WARRANT A
WATCH...BUT GIVEN RAINFALL IN THE LOWER DAN RIVER BASIN...THE DAN AT
SOUTH BOSTON WILL REACH MINOR FLOOD STAGE LATER BY DAWN TODAY...THEN
DROP BELOW FLOOD STAGE TONIGHT. FLOOD WARNING ALREADY ISSUED FOR
THIS AREA. WILL HAVE TO MONITOR RANDOLPH ON THE ROANOKE RIVER AND A
FEW SURROUNDING STREAMS AND RIVERS THRU THE DAY.
AS THE LOW OFF THE COAST AND UPPER LOW MOVE NORTHWARD MODELS ARE
INDICATING SHARPER PRESSURE GRADIENT SITUATED OVER THE MOUNTAINS
THIS AFTERNOON. WINDS WILL BE GUSTY BUT NOTHING OVER 35 MPH SHOULD
OCCUR. WITH THE COOLER TEMPS ESPECIALLY IN THE HIGHER RIDGES...THE
WINDS WILL ADD A NIP IN THE AIR.
SPEAKING OF WHICH WILL SEE THE COLDER POCKET OF AIR MOVE EAST...SO
ANY SNOW ACROSS THE NC HIGH COUNTRY INTO FAR SW VA SHOULD BE GONE BY
MID MORNING.
SOME SUNSHINE COULD WORK INTO THE NC/VA FOOTHILLS BY MID AFTERNOON.
HIGH TEMPS WILL RANGE FROM THE UPPER 40S TO LOWER 50S ACROSS THE
HIGHER ELEVATIONS OF THE WEST...WITH MID TO UPPER 50S ELSEWHERE WEST
OF THE BLUE RIDGE...TO LOWER TO MID 60S EAST.
TONIGHT...THE UPPER LOW WILL BE OVER ERN PA/NJ. SHOULD BECOME DRIER
AS WE HEAD THROUGH THE OVERNIGHT...WITH SKIES CLEARING IN THE SOUTH
AND WEST. SOME FOG MAY BECOME AN ISSUE LATE TONIGHT GIVEN THE WET
GROUND...THOUGH WINDS MAY STAY UP JUST ENOUGH TO PREVENT A
WIDESPREAD EVENT. LOWS WILL BE CLOSE TO NORMAL WITH LOWER TO MID 40S
WEST...TO MID TO UPPER 40S EAST.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 220 AM EDT FRIDAY...
THE SLOW MOVING UPPER LOW THAT HAS BROUGHT PLENTY OF COOL AND WET
WEATHER TO OUR REGION WILL FINALLY DEPART THE REGION ON SATURDAY.
ANOTHER TROUGH/LOW MOVING THROUGH SOUTH CENTRAL CANADA WILL BE
THE KICKER THAT GETS THE CLOSED LOW MOVING. THE BASE OF THE TROUGH
AXIS OF THIS CANADIAN SYSTEM WILL SWING THROUGH OUR REGION BY
SATURDAY EVENING.
SHOWERS WILL STILL BE IN OUR FORECAST THIS WEEKEND. AFTER A SMALL
BREAK IN THE ACTIVITY SATURDAY MORNING...ISOLATED TO SCATTERED
SHOWERS WILL RETURN TO WESTERN PARTS OF THE AREA SATURDAY AFTERNOON
IN ASSOCIATION WITH THE APPROACH OF THE TROUGH AXIS OF THE CANADIAN
SYSTEM. ISOLATED THUNDER CANNOT BE RULED OUT IN THE FAR WEST.
LIMITED...IF ANY...PRECIPITATION IS EXPECTED EAST OF THE CREST OF
THE BLUE RIDGE. COVERAGE WILL INCREASE SATURDAY NIGHT AS THE UPPER
TROUGH AXIS CROSSES THE REGION. EXPECT THE GREATEST COVERAGE ACROSS
SOUTHEAST WEST VIRGINIA. AN ASSOCIATED SURFACE BOUNDARY IS PROGGED
TO STALL OVER THE REGION IN THE WAKE OF THE PASSAGE OF THE UPPER
TROUGH. THIS FEATURE IS EXPECTED TO ACT AS A FOCUS FOR ADDITIONAL
ISOLATED TO SCATTERED COVERAGE OF SHOWERS HEADING INTO SUNDAY...WITH
THE BEST COVERAGE ACROSS THE SOUTHWEST PORTION OF THE FORECAST AREA.
SUNDAY NIGHT INTO MONDAY...WHAT REMAINS OF THE STALLED FRONTAL
BOUNDARY WILL SLOWLY HEAD NORTH THROUGH THE REGION IN RESPONSE TO A
DEEPENING UPPER TROUGH IN THE CENTRAL PORTION OF THE COUNTRY.
SOUTHWEST FLOW AHEAD OF THIS FEATURE WILL START TO TAP GULF OF
MEXICO MOISTURE AND ADVECT IN OUR WAY. ISOLATED TO SCATTERED SHOWERS
WILL REMAIN IN OUR FORECAST...WITH THE BEST COVERAGE ACROSS THE
NORTHERN AND WESTERN SECTIONS OF THE FORECAST REGION.
TEMPERATURES DURING THIS PORTION OF THE FORECAST WILL TREND SLIGHTLY
MILDER AND BE WITHIN A FEW DEGREES EITHER SIDE OF NORMAL FOR THIS
TIME OF THE YEAR.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 345 PM EDT THURSDAY...
THE FRONTAL BOUNDARY WILL LIFT NORTH AS A WARM FRONT TUESDAY.
MOISTURE CONVERGENCE ALONG THIS FRONT WILL RESULT IN A RISK FOR
SHOWERS AND PERHAPS A FEW THUNDERSTORMS DURING THE PERIOD. ON
WEDNESDAY...OUR AREA WILL BE IN THE WARM SECTOR WITH A WAVY WARM
FRONT TO THE NORTH AND A COLD FRONT TO OUR WEST IN THE OHIO
VALLEY. ON WEDNESDAY NIGHT INTO THURSDAY...THE LOW PRESSURE WILL
LIFT NORTH INTO THE GREAT LAKES AND ASSOCIATED COLD FRONT WILL
MOVE EAST INTO OUR REGION. THERE IS ENOUGH INSTABILITY TO MENTION
GOOD CHANCE OF THUNDERSTORMS FOR THE NORTHWEST ON WEDNESDAY.
HOWEVER...THE GREATEST INSTABILITY AS SEEN IN THE LIS IS TO OUR
WEST AND SOUTHEAST. THE UNSETTLED WEATHER WILL CONTINUE ON
THURSDAY...AS ANOTHER CLOSED LOW DROPS INTO THE UPPER MIDWEST AND
GREAT LAKES REGIONS AND SHORTWAVES ROTATE AROUND THE BASE OF THE
LOW. TEMPERATURES WILL MODERATE INTO MIDWEEK. THEN...BEHIND THE
COLD FRONT...A COOL DOWN IS POSSIBLE FOR THE END OF THE WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
THE UPPER LEVEL LOW THAT CREATED POOR FLIGHT CONDITIONS FOR MUCH OF
THE PAST FEW DAYS IS FINALLY EXITING THE REGION TO THE EAST.
SHOWERY CONDITIONS WILL BEGIN TO FORM UP IN THE REGION THIS
AFTERNOON AT PEAK HEATING. BASED ON HRRR GUIDANCE...ROA/LYH/DAN WILL
SEE SOME OF THIS ACTIVITY IN THE AFTERNOON INTO THE EVENING HOWEVER
CONDITIONS LOOK TO REMAIN PRIMARILY VFR. OTHER LOCATIONS...CURRENTLY
FORECAST FOR VICINITY SHOWERS DUE TO LOWER CONFIDENCE.
FOG WAS CONSIDERED FOR THE OVERNIGHT HOURS BUT ENOUGH MIXING SHOULD
OCCUR TO ELIMINATE THAT THREAT. LYH AND DAN APPEAR TO BE AT MOST
THREAT BUT WAS LEFT OUT FOR NOW DUE TO LOW CONFIDENCE.
WINDS ARE CURRENTLY A BIT GUSTY AND PRIMARILY FROM THE NORTHWEST FOR
MUCH OF THE REGION. THESE SHOULD CALM DOWN WITH SUNSET BUT SHOULD
BEGIN AGAIN AROUND SUNRISE. LYH SHOULD BE SPARED FROM THIS DUE TO
TOPOGRAPHY.
EXTENDED DISCUSSION...
MAINLY VFR INTO SATURDAY BEFORE NEXT FRONT AND UPPER DISTURBANCE
ARRIVE SAT NIGHT-SUN WHICH COULD BRING SUB VFR WEATHER TO THE
AREA...MAINLY BCB/BLF/LWB.
MONDAY WILL BE MAINLY VFR WITH SOUTHWEST FLOW IN PLACE THOUGH WARM
FRONT MAY BRING SOME MVFR CIGS AND POSSIBLE SHOWERS TO THE
MOUNTAINS. WE WILL BE IN THE WARM SECTOR BY TUESDAY WITH ISOLATED
TO SCATTERED SHOWERS OR THUNDERSTORMS EXPECTED. SOME MVFR POSSIBLE
WITH THOSE OTHERWISE VFR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...MBS/WP
NEAR TERM...KK/WP
SHORT TERM...DS
LONG TERM...KK
AVIATION...JR/WP
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
340 PM CDT FRI MAY 6 2016
.TONIGHT AND SATURDAY... FORECAST CONFIDENCE MEDIUM.
THE RIDGE OF HIGH PRESSURE WITH ALL THE WARM AIR OVER THE UPPER
MIDWEST LEANED INTO WISCONSIN TODAY. A COLD FRONT WILL SLIDE DOWN
THROUGH WI OVERNIGHT AND CLEAR SOUTHEAST WI BY MID SATURDAY MORNING.
GUSTY NORTH TO NORTHEAST WINDS WILL ACCOMPANY THE FRONT IN SOUTHERN
WI LATE TONIGHT.
THERE ARE TWO CHANCES FOR SHOWERS AND MAYBE SOME ELEVATED
THUNDERSTORMS TONIGHT. THE HRRR MODEL... AND TO A LESSER EXTENT
OTHER MESO MODELS... IS MORE ROBUST ON THE IDEA OF
SHOWERS/CONVECTION WELL AHEAD OF THE FRONT AND THE NAM/GFS/ECMWF
FOCUS IT ALONG THE FRONT. KEPT CHANCE OF SHOWERS AND THUNDERSTORMS
FOR THE MAJORITY OF THE NIGHT INTO EARLY SATURDAY TO ACCOUNT FOR
THESE SCENARIOS.
THE HRRR SOLUTION SHOWS SHOWERS/STORMS IN SOUTHERN WI BETWEEN 05Z
AND 08Z. IT IS PICKING UP ON A WEAK MID LEVEL SHORTWAVE AND THETA-E
ADVECTION AND THE FOCUS OF THE 850MB LOW LEVEL JET. THE NAM IS
SHOWING OVER 1000 J/KG OF ELEVATED INSTABILITY WHILE THE GFS HAS
MUCH LOWER VALUES. THERE IS NOT A LOT OF MOISTURE AVAILABLE SO NOT
EXPECTING ANY WIDESPREAD SHOWERS/STORMS.
IF THE SHOWERS END UP DEVELOPING CLOSER TO THE COLD FRONT... LIKE
ALONG AND BEHIND IT... THEY WOULD AFFECT SOUTHERN WI BETWEEN 11Z AND
17Z SATURDAY MORNING. THESE WOULD BE ASSOCIATED WITH SURFACE
CONVERGENCE ALONG THE FRONT AND STRONG MID LEVEL VORTICITY ADVECTION.
MODELS ARE SHOWING VERY LITTLE ELEVATED INSTABILITY BY THIS TIME...
SO THE CHANCE FOR THUNDERSTORMS IS GREATLY REDUCED.
CLOUDS MAY LINGER FOR A FEW HOURS IN THE WAKE OF THE COLD FRONT.
THEN DRY AIR WILL WORK ITS WAY IN AND LEAD TO SUNSHINE BY LATE
AFTERNOON. TEMPERATURES ARE EXPECTED TO REACH THE UPPER 60S INLAND
BUT ONLY THE UPPER 50S NEAR THE LAKE DUE TO STEADY NORTHEAST WINDS.
.SATURDAY NIGHT THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE MEDIUM
MODELS SHOWING A MODERATE TO STRONG FRONTOGENETIC RESPONSE IN THE
700 TO 500 MB LAYER THAT CROSSES SOUTHERN WISCONSIN SATURDAY EVENING
WITH THE 700 MB COLD FRONT AS A SHORT WAVE SWEEPS ACROSS NE
WISCONSIN LATE SATURDAY AFTERNOON AND EVENING. NO PRECIPITATION IS
EXPECTED AS MEAGER MOISTURE ON FORECAST SOUNDINGS AND CROSS SECTIONS
WITH SURFACE HIGH PRESSURE BUILDING IN MEANS NO MORE THAN SOME MID
LEVEL CLOUDS WITH THIS FRONT...THAT STALLS OVER THE SOUTH OVERNIGHT.
DRY WEATHER EXPECTED TO CONTINUE THROUGH MOST OF SUNDAY NIGHT WITH
SHORT WAVE RIDGING BETWEEN LARGE EASTERN CANADIAN VORTEX AND CLOSED
500 MB LOW...AND ASSOCIATED SURFACE LOW...MOVING OUT INTO THE CENTRAL
PLAINS BY MONDAY MORNING. SOME MODELS BRING QPF WITH 700 MB OMEGA
AND MID-LEVEL MOISTURE PUSHING IN BEFORE 12Z IN THE FAR
SOUTH/SOUTHWEST SECTIONS OF THE CWA...BUT ISENTROPIC FORECASTS SHOW
LOW LEVEL MOISTURE AND BETTER ISENTROPIC ADIABATIC OMEGA REMAIN SW
OF CWA THROUGH 12Z MONDAY SO WILL KEEP POPS IN THE SLIGHT
CHANCE/LOW CHANCE CATEGORIES FOR THE FAR SOUTH AND SOUTHWEST.
NO REAL STRONG PUSH OF COLD AIR INTO SOUTHERN WISCONSIN BUT EXPECTED
MODERATE NOCTURNAL INVERSION DEVELOPING WITH LIGHT WINDS AND CLEAR
SKIES WILL PRODUCE LOWS IN THE UPPER 30S TO LOW 40S SATURDAY NIGHT.
DEEP MIXING WILL EASILY ALLOW SUNDAY HIGH TEMPERATURES TO REACH THE
UPPER 60S TO LOW 70S. TEMPERATURES WILL EVEN GET INTO THE LOW TO MID
60S IN THE LAKESIDE COUNTIES...BUT LIGHT WIND REGIME WITH SURFACE
HIGH SLIDING ACROSS STATE WILL ALLOW A LAKE BREEZE TO DEVELOP MID-
LATE AFTERNOON.
.MONDAY AND MONDAY NIGHT...FORECAST CONFIDENCE MEDIUM
PRECIPITATION CHANCES INCREASE WITH CONVERGENCE AND FRONTOGENETIC
RESPONSE TO 850-700 MB WARM AIR/MOISTURE ADVECTION...ENHANCED BY
DIFFERENTIAL CVA WITH SHORT WAVE APPROACHING SOUTHERN WISCONSIN
MONDAY EVENING. THOUGH SURFACE BASED INSTABILITY WILL BE LOW AS
SURFACE WARM FRONT GETS UP TO THE IL/WI BORDER MONDAY EVENING THEN
STALLS...ELEVATED CAPE VALUES MONDAY AFTERNOON AND NIGHT CLIMB TO
400-600J/KG SO DO EXPECT THUNDERSTORMS. PRECIPITATION AND EAST WINDS
LEAD TO CUTTING MONDAY HIGH TEMPERATURES FROM PREVIOUS FORECAST.
.LONG TERM...TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM
PERIODIC SHOWERS...WITH A FEW THUNDERSTORMS EARLY IN THE EXTENDED
...ARE EXPECTED WITH THE ACTIVE UPPER AIR PATTERN. MODELS SIMILAR
WITH FEATURES BUT DIFFER WITH TIMING AND POSITION. CANADIAN GEM
AND ECMWF HINT AT A BREAK IN THE PCPN CHANCES FOR A TIME ON
WEDNESDAY...WHILE THE GFS IS RAIN-FREE OVER SRN WI ON THURSDAY.
WILL HAVE TO KEEP CHANCE/SLIGHT CHANCE POPS IN EVERY PERIOD
THROUGH THERE WILL BE SOME BREAKS IN THE PRECIPITATION. THE CLOUDS
AND PERIODIC SHOWERS WILL KEEP TEMPERATURES AT OR SLIGHTLY BELOW
NORMAL.
&&
.AVIATION/00Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD... ALTHOUGH BRIEF
LOWER CATEGORIES WILL BE OVERNIGHT TONIGHT WITH ANY THUNDERSTORM.
A COLD FRONT WILL SLIDE DOWN THROUGH SOUTHERN WI LATE TONIGHT INTO
MID SATURDAY MORNING. THERE IS A CHANCE FOR SHOWERS AND
THUNDERSTORMS WELL AHEAD OF THE FRONT... AROUND 1 TO 3 AM. THERE IS
ANOTHER CHANCE FOR SHOWERS AND LESS OF A CHANCE FOR THUNDER ALONG
THE FRONT EARLY SATURDAY MORNING.
EXPECT GUSTY NORTH TO NORTHEAST WINDS IN THE WAKE OF THE FRONT
SATURDAY MORNING... BUT THEY WILL DIMINISH THROUGH THE AFTERNOON.
CEILINGS ASSOCIATED WITH THE FRONT ARE EXPECTED TO REMAIN VFR.
&&
.MARINE...
GUSTY NORTH TO NORTHEAST WINDS ARE EXPECTED IN THE WAKE OF A COLD
FRONT EARLY SATURDAY MORNING. WAVES WILL APPROACH 5 FEET FROM
MILWAUKEE AND SOUTH. A SMALL CRAFT ADVISORY IS IN EFFECT. WINDS
AND WAVES WILL DIMINISH SATURDAY AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/SATURDAY AND AVIATION/MARINE...MRC
SATURDAY NIGHT THROUGH FRIDAY...REM