Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/12/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
225 PM MST SUN MAY 10 2015
.SYNOPSIS...
NEAR NORMAL TEMPERATURES WITH PLENTY OF SUNSHINE CAN BE EXPECTED
THROUGH THURSDAY ACROSS THE DESERT SOUTHWEST. FRIDAY THROUGH SUNDAY
...ANOTHER UNSEASONABLY COOL STORM WILL ARRIVE...USHERING IN MUCH
COOLER TEMPERATURES...BREEZY CONDITIONS...AND HEIGHTENED CHANCES FOR
RAIN.
&&
.DISCUSSION...
BENIGN WEATHER ACROSS OUR FORECAST AREA THIS AFTERNOON WITH NEARLY
ZERO CLOUD COVER. SOME WEAK ECHOES HAVE DEVELOPED OVER THE RIM/WHITE
MTNS RESULTING IN SOME THUNDER. BASED ON HRRR TRENDS/FLOW NOT
EXPECTING THAT ACTIVITY TO IMPACT OUR AREA.
TAKE-HOME MESSAGE AT THIS TIME IS NEAR/ABOVE NORMAL TEMPERATURES
EARLY IN THE WEEK WILL GIVE WAY TO ANOTHER ROUND OF UNSEASONABLY
COOL AND SHOWERY WEATHER BY FRIDAY THAT WILL LAST THROUGH THE
WEEKEND.
FIRST HALF OF THE WEEK...NOT MUCH TO DISCUSS. SHORT TERM MODELS ARE
LOCKED INTO THE DEPARTING LOW AND INCOMING SHORT WAVE RIDGE YIELDING
LITTLE DIFFERENCE IN FORECAST MAX/MIN TEMP VALUES. TUESDAY COULD BE A
BIT INTERESTING AS A SHORT WAVE RIDES THE SOUTHERLY FLOW AND ADVECTS
SOME MOISTURE INTO EASTERN ARIZONA...THOUGH POTENTIAL IMPACT TO OUR
FORECAST AREA IS MINIMAL AT THIS TIME.
GLOBAL ENSEMBLE DATA AND DETERMINISTIC RUNS OF EC/GFS ARE IN REALLY
GOOD AGREEMENT ON THE BROAD DETAILS FOR FRIDAY THROUGH SUNDAY.
ANOTHER LARGE CLOSED LOW...OF WHICH THE CURRENT ENERGY IS NEAR THE
ALEUTIAN ISLANDS...WILL MOVE INTO SOCAL AND AZ FRIDAY. THERE WILL BE
A LEADING SHORT WAVE WHICH WILL LIKELY GIVE US OUR BEST CHANCE OF
RAIN...CURRENTLY TIMES TO ARRIVE DURING THE DAY FRIDAY. WE COULD SEE
SOME ENHANCED WINDS AS THE SYSTEM LAYS INTO ARIZONA...IF HUMIDITY
VALUES ARE STILL LOW WHEN THIS HAPPENS WE COULD HAVE A PERIOD OF
CRITICAL FIRE WEATHER CONDITIONS. SOMETHING TO WATCH.
BROAD TROUGHING WILL CONTINUE THROUGH THE WEEKEND. HARD TO SAY
IF/WHEN SHOWERS WILL OCCUR AS THAT/LL HINGE ON THE FINER DETAILS OF
SHORT WAVE ENERGY ROTATING AROUND THE PARENT LOW. THERE DOES SEEM TO
BE QUITE HIGH CERTAINTY THAT WE/RE IN FOR ANOTHER WEEKEND IN MAY OF
COOL TEMPS. CURRENT FORECAST HIGH TEMPS ON SATURDAY RANGE FROM 10 TO
20 DEGREES BELOW NORMAL. AN ANALYSIS OF HISTORICAL PHOENIX RECORDS
INDICATE THAT THERE HAVE ONLY BEEN FIVE INSTANCES/YEARS WHERE THE
MONTH OF MAY HAD TWO OR MORE SATURDAYS WITH A HIGH TEMP BELOW 80F
/LAST WAS IN 1971/. WITH A CURRENT FORECAST HIGH OF 78 FOR THIS
COMING SATURDAY...2015 WOULD BE THE SIXTH.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND
KBLH...
DRY WESTERLY FLOW ALOFT PROVIDING CLEAR SKIES AND LIGHT WINDS
THROUGH MONDAY EVENING. WIND DIRECTIONS SHOULD MOSTLY FOLLOW TYPICAL
DIURNAL PATTERNS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
WARM TEMPERATURES AND LOW HUMIDITY VALUES WILL BE ESTABLISHED MID-
WEEK BUT THAT WILL CHANGE BY FRIDAY AS ANOTHER UNSEASONABLY COOL
STORM SYSTEM ENTERS THE SOUTHWEST. BREEZY WINDS WILL ACCOMPANY THE
SYSTEM AS IT MOVES IN THURSDAY AND EARLY FRIDAY AND COULD COMBINE
WITH STILL DEPRESSED HUMIDITY VALUES FOR A PERIOD OF CRITICAL FIRE
WEATHER CONDITIONS. AS THE SYSTEM EASES IN LATER FRIDAY...
TEMPERATURES WILL DROP AND HUMIDITY VALUES WILL INCREASE. CHANCES
FOR WETTING RAIN...ESPECIALLY ACROSS CENTRAL ARIZONA...WILL ALSO
INCREASE. THIS WEATHER PATTERN WILL LIKELY REMAIN THROUGH THE
WEEKEND.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
931 AM MST SUN MAY 10 2015
.UPDATE...
LITTLE CHANGE IN THE FORECAST FOR TODAY. BROAD CYCLONIC FLOW REMAINS
ACROSS THE REGION AS A LARGE CLOSED LOW MOVES OUT INTO THE PLAINS
FROM THE MOUNTAIN WEST. NOTED A JET STREAK COMING DOWN THE BACK SIDE
IN THIS MORNING/S RAOBS AND MODEL INITIAL FIELDS. MOISTURE IS SCANT
THOUGH AND WITH MID-LEVELS ALREADY WARMING NOT EXPECTING MUCH IN WAY
OF SHOWER/TSTM ACTIVITY FOR OUR AREA. CU FIELDS ARE OFF TO AN EARLY
START ACROSS NORTHERN ARIZONA BUT LIMITED DEVELOPMENT AND MOVEMENT
WILL PRECLUDE US FROM SEEING MUCH IF ANY ACTIVITY. HRRR RUNS SEEM
DIALED INTO THAT SOLUTION. DID MAKE MODEST ADJUSTMENTS TO MAX TEMPS
FOR TODAY BASED ON PAST FEW HRRR RUNS...TEMPERATURES NEAR NORMAL LOOK
ON-TRACK. OVERALL A QUIET AND PLEASANT SUNDAY UNFOLDING.
&&
.SYNOPSIS...
A LOW PRESSURE SYSTEM IN THE PLAINS WILL CONTINUE TO BRING BELOW
NORMAL TEMPERATURES TO THE DESERT SOUTHWEST TODAY. HIGH PRESSURE
WILL THEN ALLOW TEMPERATURES TO RETURN TO NORMAL VALUES BY EARLY NEXT
WEEK ALTHOUGH MID TO LATE WEEK TROUGHING ACROSS THE PACIFIC NORTHWEST
SHOULD PREVENT TEMPERATURES FROM CLIMBING INTO THE TRIPLE DIGITS.
THERE WILL ALSO BE AN INCREASING CHANCE OF PRECIPITATION LATE IN THE
WEEK AS A TROUGH APPROACHES THE AREA.
&&
.DISCUSSION...
UPPER LEVEL LOW PRESSURE OVER COLORADO REMAINS THE DOMINANT WEATHER
FEATURE ACROSS THE WESTERN CONUS...AND CONTINUES TO USHER BELOW
NORMAL TEMPERATURES INTO THE REGION. LATE DAY SHOWERS AND CU ACROSS
THE REGION HAVE LONG SINCE DISSIPATED...BUT ONE FINAL SHORTWAVE
TROUGH WAS MAKING ITS WAY THROUGH NORTHWEST ARIZONA THIS MORNING.
REGIONAL RADAR MOSAIC INDICATED VERY ISOLATED SHOWERS SOUTH OF LAS
VEGAS EARLIER THIS MORNING...BUT EVEN THESE HAVE STARTED DYING OFF
SINCE 08Z. THIS HAS RESULTED IN ANOTHER MORNING OF MOSTLY CLEAR
SKIES...LOW DEWPOINTS...AND UNSEASONABLY COOL TEMPERATURES ACROSS THE
DESERTS. REGIONAL OBS AS OF 09Z REVEAL TEMPERATURES IN THE MID 50S TO
LOWER 60S...WHICH IS ALREADY 5-10 DEGREES BELOW NORMAL FOR MAY 10TH.
THE AFOREMENTIONED SHORTWAVE WILL QUICKLY MOVE THROUGH THE AREA
TODAY...ONLY BRINGING A SLIGHT INCREASE IN MID CLOUDS TO THE AREA.
PRECIP CHANCES ARE LARGELY NIL TODAY ALTHOUGH I CAN`T RULE OUT A
STRAY SHOWER OVER THE MOUNTAINS NORTH/EAST OF PHOENIX.
ACCORDINGLY...I HAVE RETAINED 5-10 POPS EAST OF GLOBE. ANY SHOWERS
THAT DEVELOP WILL DISSIPATE QUICKLY WITH THE LOSS OF DAYTIME
HEATING...NOT TO MENTION INCREASING ANTICYCLONIC FLOW ALOFT AS
RIDGING BEGINS TO STRENGTHEN ACROSS SOUTHERN CALIFORNIA.
THE UPPER RIDGE WILL DEVELOP AND STRENGTHEN ACROSS SOUTHERN
CALIFORNIA AND ARIZONA MONDAY THROUGH TUESDAY WITH TEMPERATURES
QUICKLY RETURNING TO NORMAL VALUES. BIAS CORRECTED CONSENSUS GUIDANCE
HAS BEEN SUGGESTING HIGHS IN THE MID 90S MONDAY THROUGH WEDNESDAY AND
THIS IS STILL THE CASE WITH TODAY`S 00Z VALUES. VERY HIGH
CONFIDENCE/LITTLE CHANGE IN THE FORECAST THROUGH MID WEEK.
THINGS TURN A BIT MORE INTERESTING AS WE GET CLOSER TO THURSDAY...AND
CERTAINLY BY FRIDAY INTO THE WEEKEND. ENSEMBLE MEANS OVER THE PAST
FEW DAYS HAVE ADVERTISED PERSISTENT TROUGHING ACROSS THE WESTERN
CONUS AS AN UPPER LOW MOVES THROUGH THE PAC NW INTO THE GREAT
BASIN. DETERMINISTIC GUIDANCE HAS BEEN IN AGREEMENT FOR THE MOST
PART DURING THIS LATE-WEEK PERIOD...ALTHOUGH NOT SURPRISINGLY EACH
RUN OF EACH MODEL HAS VARIED SOMEWHAT UP UNTIL RECENTLY. YESTERDAY`S
12Z AND TODAY`S 00Z DETERMINISTIC GFS AND ECMWF HAVE COME INTO MUCH
BETTER AGREEMENT...AND SUGGEST A SUBSTANTIAL INCREASE IN BL MOISTURE
LATE IN THE WEEK COINCIDENT WITH THE ARRIVAL OF A VERY POTENT 500MB
SHORTWAVE TROUGH. GFS IN PARTICULAR INDICATES PWATS CLIMBING INTO THE
0.8 TO 1.0 INCH RANGE ON FRIDAY...WHICH WOULD BE WELL INTO THE 99TH
PERCENTILE OF OBSERVED PWATS ACROSS ARIZONA FOR THE MIDDLE OF MAY.
WITH A PROLONGED RESIDENCE TIME OVER THE EASTERN PACIFIC...IT WILL
CERTAINLY HAVE MORE THAN ENOUGH TIME TO ADVECT MOISTURE INTO THE
AREA AND THE 00Z NAEFS AGREES /INTEGRATED WV TRANSPORT CLIMBS WELL
INTO THE 90TH PERCENTILE ON FRIDAY/. ECMWF IS A BIT SLOWER AND
SLIGHTLY DRIER...BUT HAS THE SAME BASIC IDEA. I WENT AHEAD AND
INCREASED POPS ABOVE CLIMO /INTO THE 10-30 PERCENT RANGE/ FOR FRIDAY
AND SATURDAY ALTHOUGH THE EXACT TIMING WILL NEED TO BE NAILED
DOWN...AS ITS UNLIKELY WE`D SEE PERSISTENT SHOWERS FOR 2 STRAIGHT
DAYS. ALSO TOOK A BIG SWING DOWNWARD WITH TEMPERATURES...CONSENSUS
GUIDANCE YIELDS HIGHS IN THE UPPER 70S AND THIS SEEMS MORE THAN
REASONABLE.
OVERALL...CONFIDENCE IS HIGH IN THE DEVELOPMENT OF A
COOL/WET LATE-WEEK PATTERN. CONFIDENCE IN EXACT TIMING OF THE ONSET
OF SHOWERS AND STORM TOTAL PRECIP AMOUNTS IS LOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND
KBLH...
DRY WESTERLY FLOW ALOFT PROVIDING CLEAR SKIES AND LIGHT WINDS
THROUGH MONDAY AFTERNOON. WIND DIRECTIONS SHOULD MOSTLY FOLLOW
TYPICAL DIURNAL PATTERNS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE AND ITS ASSOCIATED WARMTH WILL RETURN TO THE DISTRICTS
EARLY NEXT WEEK. THIS WILL RESULT IN TEMPERATURES RETURNING TO NEAR
NORMAL VALUES WITH DRY CONDITIONS. MINIMUM AFTERNOON HUMIDITY LEVELS
WILL FALL INTO THE SINGLE DIGITS AND TEENS WITH FAIR OVERNIGHT
RECOVERY. BY THE MIDDLE PART OF THE WEEK ANOTHER SERIES OF PACIFIC
STORMS WILL MOVE INTO THE WESTERN CONUS AND GENERATE BREEZY TO
LOCALLY WINDY CONDITIONS FOR THE FIRE WEATHER ZONES. FIRST ON
THURSDAY...LOWERING DAYTIME HUMIDITIES COUPLED WITH STRONG WINDS MAY
DEVELOP AREAS OF CRITICAL FIRE WEATHER CONDITIONS OVER PORTIONS OF
SOUTH-CENTRAL AZ. NEXT FOR THE LATE WEEK/NEXT WEEKEND...TEMPERATURES
WILL BE BEGIN TO COOL AND DEWPOINTS COME UP SLIGHTLY AS A LARGER AND
COOLER PACIFIC STORM IS NOW FORECAST INTO THE AREA.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...INIGUEZ/LEINS
AVIATION...INIGUEZ
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
323 PM MDT SUN MAY 10 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 323 PM MDT SUN MAY 10 2015
NORTH TO NORTHWESTERLY FLOW CONTINUES ON THE BACK SIDE OF THE LOW
PRESSURE SYSTEM THAT BROUGHT ALL THE SNOW AND RAIN YESTERDAY. THE
NAM12/EC/GFS ALL SHOW A SHORTWAVE MOVING OVER THE FORECAST AREA
THIS EVENING BRINGING ANOTHER ROUND OF PRECIP WITH MOUNTAINOUS
TERRAIN SEEING MORE SNOWFALL. HOWEVER...THESE MODELS DID NOT
INITIALIZE WELL THIS MORNING AND ARE CURRENTLY OVERDOING
QPF/PRECIP. MEANWHILE...THE HRRR AND RAP13 APPEARED TO BE DOING
MUCH BETTER WITH NAILING PRECIP AND WILL FOLLOW THESE SOLUTIONS
IN THE SHORT TERM.
FOR THIS AFTERNOON THEN...WITH COLD AIR ADVECTING IN...MINOR
INSTABILITY EXISTS AND WITH CLOUDS BREAKING UP SOME...A FEW
RUMBLES POSSIBLE THIS AFTN MAINLY FOR ERN UT AND SWRN CO. FOR THIS
EVENING AND TONIGHT...THE RAP13 SHOWS ALMOST NO PRECIP WHILE THE
HRRR DOES SHOW THE WAVE MOVING THROUGH BUT PRECIP AMTS ARE LIGHT
AS THE DISTURBANCE QUICKLY MOVES OVERHEAD. PUT ISOLD/SCTD PRECIP
FOR NORTHERN VALLEYS AND ALL HIGHER TERRAIN TONIGHT.
NORTHERLY FLOW WILL ALSO BRING COOLER TEMPERATURES TO THE REGION
WITH NORTHERN VALLEYS AND SOUTHERN VALLEYS SEEING FREEZING OR JUST
BELOW FREEZING TEMPS. THESE TEMPS WILL BOTTOM OUT JUST BEFORE
SUNRISE SO OPTED TO NOT ISSUE ANY FREEZE WARNINGS. HIGH PRESSURE
WILL THEN BUILD IN BRINGING A PLEASANT START TO THE WORK WEEK.
ANOTHER LOW DRIFTING SOUTHWARD ALONG THE PACIFIC NORTHWEST COAST
WILL CAUSE A RIDGE TO BUILD OVER THE REGION. DECENT WARM AIR
ADVECTION (WAA) COMBINED WITH A DRY SOUTHWEST FLOW WILL BRING MORE
QUIESCENT WEATHER TO FORECAST AREA MONDAY. HOWEVER...12Z GFS DID
SUGGEST THERE MAY BE ENOUGH RESIDUAL MOISTURE OVER THE EASTERN
UINTA MOUNTAINS TO FUEL A FEW DIURNAL SHOWERS/THUNDERSTORMS.
DESPITE WARMING...AFTERNOON HIGHS WILL REMAIN SEVERAL DEGREES
BELOW NORMAL.
DRY CONDITIONS PERSIST MONDAY NIGHT THOUGH THE RIDGE AXIS WILL
SHIFT EAST OF THE CONTINENTAL DIVIDE BY 12Z/TUE AS THE NORTHWEST
PACIFIC LOW PRESSURE SYSTEM MOVES ASHORE OVER SOUTHWEST OREGON.
OVERNIGHT LOWS WILL FALL TO NEAR NORMAL LEVELS AS LOSS OF CLOUD
COVER IS BALANCED BY WAA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 323 PM MDT SUN MAY 10 2015
THE LOW REMAINS NEARLY STATIONARY DURING THE DAY ON TUESDAY AS A
STRONG VORTICITY LOBE MOVES THROUGH ITS BASE. MEANWHILE...
ISENTROPIC FIELDS INDICATED A SURGE OF LOW LEVEL MOISTURE
ORIGINATING FROM THE GULF OF MEXICO WILL MOVE NORTHWARD OVER THE
CONTINENTAL DIVIDE FUELING SCATTERED SHOWERS AND THUNDERSTORMS
DURING THE AFTERNOON. OVER NORTHEAST UTAH...MODELS DIVIDED ON
WHETHER ENOUGH MOISTURE WILL REMAIN OVER THE EASTERN UINTAS TO
GENERATE MOIST CONVECTION DURING THE AFTERNOON. GIVEN MODEL
DIFFERENCES WILL CONTINUE WITH LOW CHANCES OVER THE EASTERN UINTA
MOUNTAINS. AS WAA ADVECTION CONTINUES...AFTERNOON HIGHS ARE
EXPECTED TO CONTINUE TO INCREASE WITH LATEST GUIDANCE INDICATING
HIGHS AROUND 5 DEGREES ABOVE NORMAL.
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO TUESDAY EVENING AND
MAY PERSIST OVER THE SAN JUAN MOUNTAINS LATE INTO THE NIGHT AS A
SHORTWAVE IN THE SOUTHERN STREAM MOVES ACROSS THE SOUTHWEST.
EXPECT ANOTHER ROUND OF DIURNALLY DRIVEN MOIST CONVECTION
WEDNESDAY AFTERNOON/EVENING WITH SOME ENHANCEMENT ACROSS THE SOUTH
ASSOCIATED WITH THE SHORTWAVE TROUGH MENTIONED PREVIOUSLY. ON
THURSDAY...THE TROUGH ALONG THE PACIFIC NORTHWEST SLIPS SOUTHWARD
ALLOWING MOISTURE TO CONTINUE STREAMING NORTHWARD OVER THE DIVIDE.
AS A RESULT...EXPECT SIMILAR CONDITIONS TO WEDNESDAY WITH STORMS
LARGELY ANCHORED TO THE COLORADO MOUNTAINS. AFTERNOON HIGHS WILL
CONTINUE TO RUN SEVERAL DEGREES ABOVE NORMAL AS WAA IN SOUTHWEST
FLOW PERSISTS.
HOWEVER...THE WARM PERIOD ENDS FRIDAY AS A SLUG OF PACIFIC
MOISTURE DRIVEN ACROSS THE SOUTHWEST BY A VORTICITY LOBE EJECTED
FROM THE LOW CENTERED OVER SAN FRANCISCO COMBINES WITH GULF
MOISTURE ALREADY IN PLACE. DIABATIC COOLING ASSOCIATED WITH
INCREASED CLOUDS AND SHOWERS WILL DRIVE COOLING WITH HIGHS
DROPPING OFF BY ABOUT 10 DEGREES RELATIVE TO THURSDAY/S FORECAST
HIGHS WITH READINGS COMING IN ABOUT 5 DEGREES BELOW NORMAL. MODELS
IN FAIRLY GOOD AGREEMENT FOR THE WEEKEND WITH BOTH THE GFS AND
ECMWF DEPICTING ANOTHER MOIST...COOL...AND UNSETTLED PERIOD AS THE
LOW MOVES FROM THE WEST COAST AND ACROSS THE FORECAST AREA
EVENTUALLY REACHING THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON MONDAY)
ISSUED AT 1100 AM MDT SUN MAY 10 2015
KASE...KEGE...AND KTEX WILL LIKELY SEE THE BIGGEST IMPACT TODAY
WITH CLOUDS AND PRECIP OFF AND ON THROUGH THE DAY. VFR/MVFR WILL
BE COMMON. REMAINING TAF SITES WILL SEE CONDITIONS SLOWLY IMPROVE
FROM SOUTH TO NORTH THROUGH THE DAY WITH VFR EXPECTED FOR THE MOST
PART. SOME FOG IS POSSIBLE TOWARDS DAYBREAK BUT NOT QUITE CONFIDENT
ENOUGH YET TO INCLUDE IN TAFS. MTN OBSCURATIONS WILL CONTINUE INTO
THE OVERNIGHT PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...TGR/NL
LONG TERM...NL
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1058 AM MDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1048 AM MDT SUN MAY 10 2015
SHORT RANGE GUIDANCE...THE HRRR AND RAP...CONTINUE TO DOWNPLAY
PRECIP FROM THIS NEXT WAVE THAT IS PROGGED TO MOVE OVER THE AREA
THIS EVENING. RAP HAS ALMOST NO PRECIP WHILE HRRR DOES SHOW SOME
QPF BUT VERY QUICK MOVING AND LIGHT. NAM AND GFS GUIDANCE NOT
PANNING OUT SO FAR THIS MORNING AS THEY BOTH PAINT MUCH MORE
WIDESPREAD PRECIP THAN IS OCCURRING. ALL ROADS ARE NOW WET WITH
LITTLE TO NO SNOW OR ICE SEEN ON WEBCAMS. WILL FOLLOW HRRR/RAP
LEAD AND UPDATE FORECAST AND LOWER POP/QPF AMTS...ALSO WENT AHEAD
AND DROPPED HIGHLIGHTS. EXPECT PLENTY OF CLOUDS FOR THE
MTNS...REMAINING AREAS WILL SEE CLOUDS BREAKING UP THROUGH THE
AFTERNOON. AREAS SOUTH AND WEST MAY SEE PARTLY CLOUDY SKIES.
UPDATE ISSUED AT 857 AM MDT SUN MAY 10 2015
CLOUDS AND PRECIPITATION CONTINUE ACROSS MUCH OF THE CWA AS LOW
PRESSURE...NOW CENTERED OVER THE PLAINS...CONTINUES MOVING NEWRD.
SHORT RANGE MODELS CONTINUE PICKING UP ON SHORTWAVE MOVING ACROSS
THE AREA LATER THIS AFTERNOON AND EVENING WHEN THE COLDEST TEMPS
START DROPPING DOWN FROM THE NORTH. ANY ICE OR SNOW ON ROADS
SHOULD HAVE MELTED BY NOW BUT WITH ONGOING PRECIP AND LOWERED
VISIBILITIES...THINK ENOUGH OF AN IMPACT TO KEEP HIGHLIGHTS GOING.
WILL KEEP AN EYE ON NEXT DISTURBANCE AND HOW IT EVOLVES AS THE
DAY PROGRESSES.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 323 AM MDT SUN MAY 10 2015
AS UPPER LEVEL LOW PRESSURE OVER NE CO LIFTS INTO THE NRN PLAINS
SUNDAY...A WEAK SHORTWAVE TROUGH DROPS SOUTH FROM MT INTO EASTERN
UT BY SUNDAY EVENING AND THEN EAST ACROSS CO SUNDAY NIGHT. MID AND
UPPER LEVEL MOISTURE ASSOCIATED WITH TROWAL PATTERN OF DEPARTING
LOW HANGS AROUND THRU SUNDAY...ESPECIALLY ACROSS THE NORTHERN HALF
OF THE AREA AND WILL BE AVAILABLE FOR THE MONTANA SHORTWAVE TO
USE TO DEVELOP ADDITIONAL SHOWERS AND ISOLATED THUNDERSTORMS FOR
THE LATTER HALF OF SUNDAY. SNOW LEVELS WILL REMAIN LOW...ONLY
REBOUNDING TO AROUND 7500 FEET NORTH TO 9000 FEET SOUTH SUNDAY
AFTERNOON...SO ADDITIONAL ACCUMULATIONS OF SNOWFALL LIKELY FOR THE
HIGHER ELEVATIONS. WILL LEAVE THE WINTER STORM WARNINGS/ADVISORIES
AS THERE ARE FOR THE EARLY MORNING HOURS TO KEEP AWARENESS HIGH
FOR HAZARDOUS TRAVEL...BUT EXPECT THAT AT LEAST SOME OF THE
HEADLINES WILL BE ABLE TO BE DROPPED BY MIDDAY.
UPPER LEVEL RIDGE BUILDS ACROSS THE REGION MONDAY BRINGING A
RESPITE FROM THE WET WEATHER...ABUNDANT SUNSHINE AND MILDER
TEMPERATURES. HOWEVER...CANNOT RULE OUT ISOLATED CONVECTION OVER
THE TYPICAL DIURNALLY DRIVEN FAVORABLE SPOTS IN THE MOUNTAINS.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 AM MDT SUN MAY 10 2015
UNSETTLED CONDITIONS WILL CONTINUE FOR MUCH OF THE WEEK AS WE SEE
ANOTHER SURGE OF MOISTURE WORK NORTH TUESDAY...THEN WE START TO
WORK ON DAILY RECYCLING OF LOW LEVEL MOISTURE LEFT OVER THE REGION
THROUGH THURSDAY. EXPECTED MAINLY DIURNALLY DRIVEN SHOWERS AND
THUNDERSTORMS...CONFINED TO THE HIGHER TERRAIN WITH A FEW CELLS
TRAVELING OVER THE VALLEYS LATE IN THE DAY. TEMPS WILL BE JUMPING
BACK TO ABOVE NORMAL READINGS BY MIDWEEK IN STRENGTHENING SOUTHWEST
FLOW. ALL OF THIS IS AHEAD OF YET ANOTHER WEEKEND STORM THAT WILL
BEGIN TO IMPACT THE FORECAST AREA FRIDAY AFTERNOON AS WE SEE A
STRONGER SURGE OF EASTERN PACIFIC MOISTURE WORK NORTH OFF THE BAJA
AND INTO WESTERN COLORADO. INCREASINGLY DIFLUENT FLOW AHEAD OF THE
DIGGING LOW THAT SLIDES INTO THE GREAT BASIN ON SATURDAY PROMISES
FAIRLY WIDESPREAD PRECIPITATION BEGINNING FRIDAY NIGHT AND
CONTINUING INTO SUNDAY. GFS AND ECMWF IN MUCH BETTER AGREEMENT
WITH THIS LATEST MODEL RUN...TAKING THE NEW CLOSED LOW AND LIFTING
IT NORTH NORTHEAST INTO WYOMING BY SUNDAY MORNING AND INTO THE
WESTERN DAKOTAS BY SUNDAY NIGHT. WITH SOME MODEL CONSISTENCY
DEVELOPING...CONFIDENCE INCREASING A BIT AND WILL RAMP POPS UP A
BIT...BUT STILL BELOW LIKELY THRESHOLDS AS WE WAIT FOR A LITTLE
RUN TO RUN CONSISTENCY. TEMPS EXPECTED TO DROP BACK BELOW NORMAL
OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z NOON MONDAY)
ISSUED AT 1100 AM MDT SUN MAY 10 2015
KASE...KEGE...AND KTEX WILL LIKELY SEE THE BIGGEST IMPACT TODAY
WITH CLOUDS AND PRECIP OFF AND ON THROUGH THE DAY. VFR/MVFR WILL
BE COMMON. REMAINING TAF SITES WILL SEE CONDITIONS SLOWLY IMPROVE
FROM SOUTH TO NORTH THROUGH THE DAY WITH VFR EXPECTED FOR THE MOST
PART. SOME FOG IS POSSIBLE TOWARDS DAYBREAK BUT NOT QUITE CONFIDENT
ENOUGH YET TO INCLUDE IN TAFS. MTN OBSCURATIONS WILL CONTINUE INTO
THE OVERNIGHT PERIOD.
&&
.HYDROLOGY...
ISSUED AT 323 AM MDT SUN MAY 10 2015
MOST RIVERS IN WESTERN COLORADO REMAIN WELL BELOW BANKFULL STAGES
ALTHOUGH RECENT RAINFALL INCREASED FLOWS IN THE RIVERS. EVEN SO...A
FEW SMALLER STREAMS AND CREEKS DID INCREASE TO NEAR BANKFULL. THE
UPPER YAMPA RIVER IS AT BANKFULL FROM THE COMBINATION OF RECENT
RAIN AND SNOW MELT AND WILL REMAIN NEAR OR SLIGHTLY ABOVE BANKFULL
THROUGH THE REMAINDER OF THE WEEKEND. THE UPPER HEADWATERS OF THE
MAINSTEM RIVERS...SMALL STREAMS AND CREEKS COULD ALSO SEE ANOTHER
INCREASE IN FLOWS FROM ADDITIONAL PRECIPITATION TODAY AND TONIGHT.
THE MAINSTEM RIVERS WILL REMAIN BELOW BANKFULL LEVELS BUT COULD
ALSO SEE INCREASES IN FLOWS. LOCALIZED FLOODING IS POSSIBLE UNDER
THE STRONGEST RAINFALL DUE TO SATURATED SOILS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...TGR
SHORT TERM...BM
LONG TERM...JDC
AVIATION...TGR
HYDROLOGY...JDC/AS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1031 PM EDT MON MAY 11 2015
.SYNOPSIS...
A COLD FRONT NEAR THE MOHAWK VALLEY...AND CENTRAL NEW
ENGLAND WILL CONTINUE TO BRING A CHANCE OF SHOWERS AND THUNDERSTORMS
TO THE REGION OVERNIGHT. THE FRONT MOVES THROUGH EASTERN NEW YORK
AND WESTERN NEW ENGLAND TOMORROW INTO TOMORROW NIGHT. THE AIR MASS
WILL TURN COOLER AND DRIER ON WEDNESDAY WITH TEMPERATURES BACK TO
NEAR NORMAL OR SLIGHTLY BELOW NORMAL READINGS FOR MAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 1030 PM EDT...THE COLD FRONT HAS BECOME STATIONARY NEAR THE
MOHAWK VALLEY...LAKE GEORGE REGION...AND SRN VT THIS HOUR. ONE
CLUSTER OF SHOWERS WITH A FEW RUMBLES OF THUNDER IS MOVING ACROSS
THE SRN DACKS...AND THE NRN REACHES OF THE MOHAWK VALLEY. THIS
SHOULD MOVE ACROSS THE REGION IN THE NEXT FEW HOURS.
A MORE IMPRESSIVE LINE OF SHOWERS AND THUNDERSTORMS IS MOVING
ACROSS WRN NY. THE GENERAL TREND FROM THE LATEST HRRR/HIRES WRF IS
FOR A WEAKENING TREND AS THE LINE MOVES EASTWARD. THIS LINE LOOKS
TO GET INTO OUR FCST AREA BTWN 06Z-09Z/TUE...AND WEAKEN FURTHER AS
IT MOVES EAST OF THE HUDSON RIVER VALLEY BWTN 09Z-12Z. WE KEPT A
SLIGHT OR LOW CHC THUNDERSTORMS IN THE FCST AREA THRU THE
OVERNIGHT PERIOD. THE LATEST MESOANALYSIS RAP ON THE SPC PAGE
SHOULD SBCAPES AROUND 500 J/KG FROM THE CAPITAL REGION SOUTH AND
EAST WHERE THE AIR MASS REMAINS MUGGY WITH SFC DEWPTS IN THE LOWER
TO M60S. FURTHER NORTH...THE AIR MASS IS A BIT MORE STABLE DUE TO
THE MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS.
SOME LOCALLY HEAVY RAINFALL WILL CONTINUE OVERNIGHT WITH HIGH PWAT
VALUES IN PLACE...A FEW STD DEVS ABOVE NORMAL. LOWS OVERNIGHT ARE
EXPECTED TO BE VERY MILD...MAINLY IN THE LOWER TO M60S...EXCEPT
SOME MID AND U50S OVER THE SRN DACKS...AND SRN VT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT
LAKES EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY
HOURS TO EARLY AFTERNOON ON TUESDAY AS LOW PRESSURE MOVES ACROSS
SOUTHERN CANADA. SO THE BEST CHANCES FOR CONVECTION LOOK TO BE
THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT HIGHS ON TUESDAY IN
UPPER 60S TO LOWER 80S WITH TEMPS FALLING LATE IN THE DAY AS COLD
AIR ADVECTION TAKES HOLD.
TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE WELL EAST
OF THE REGION BY TUESDAY EVENING. HOWEVER...THE UPPER LEVEL
TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING ACROSS
MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW OF
SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN CATSKILLS...AND
BERKSHIRES NORTHWARD. IT WILL BE BRISK AND MUCH COOLER TUESDAY
NIGHT AND WEDNESDAY WITH LOWS TUESDAY NIGHT IN THE UPPER 30S TO
UPPER 40S AND HIGHS ON WEDNESDAY IN THE MID 50S TO MID 60S.
WEDNESDAY NIGHT AND THURSDAY WILL BE MARKED BY CLEAR SKIES AND
COOL CONDITIONS WITH FROST POSSIBLE ON WEDNESDAY NIGHT AS
TEMPERATURES DROP INTO THE UPPER 20S TO UPPER 30S. WILL HIGHLIGHT
THIS IN THE HWO EXCEPT FOR THE SOUTHERN ADIRONDACKS WHERE THE
GROWING SEASON HAS NOT STARTED YET. HIGHS ON THURSDAY WILL BE IN
THE 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE PERIOD STARTS OUT DRY...BUT DIFFUSE OR WEAK FRONTAL BOUNDARIES
WILL BRING AT LEAST A CHANCE OF SHOWERS FOR FRIDAY NIGHT AND
SATURDAY. THEREAFTER...THE HUMIDITY WILL HANG AROUND...BUT MOST
LOCATIONS WILL BE LOOKING AT ONLY SLIGHT CHANCES OF SHOWERS.
INSTABILITY APPEARS TO BE TOO LOE FOR THUNDERSTORMS.
HIGH TEMPERATURES WILL INCREASE FROM A RANGE OF LOWER AND MID 60S TO
THE MID 70S FRIDAY AND SATURDAY...TO FROM THE LOWER AND MID 70S TO
THE LOWER AND MID 80S ON SUNDAY. OVERNIGHT LOWS WILL ALSO MODERATE
EACH DAY...STARTING OUT WITH A THURSDAY NIGHT RANGE FROM THE UPPER
30S TO UPPER 40S...AND CULMINATING WITH SUNDAY NIGHT LOWS IN THE MID
AND UPPER 50S.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
AS OF EARLY THIS EVENING A STATIONARY FRONT LAY ACROSS CENTRAL
AND WESTERN NEW YORK AND CENTRAL NEW ENGLAND WITH MOST OF THE
SHOWERS AND THUNDERSTORMS FIRING ACROSS THE FA NORTH AND ALONG
THIS BOUNDARY. AS A RESULT WILL CONTINUE TO MENTION THUNDER AT
KGFL FOR THE NEXT COUPLE OF HOURS.
FURTHER SOUTH AND EAST AT KALB/KPSF/KPOU...ACTIVITY COVERAGE
LOOKS LESS.
WINDS THIS EVENING WILL BE SOUTHERLY AT AROUND 10 KTS WITH GUSTS
TO AROUND 20 KTS.
THERE SHOULD BE A LULL IN THE RAINFALL ACTIVITY FOR MOST OF THE
OVERNIGHT HOURS AS THE WARM FRONT LIFTS NORTHWARD...AND COLD FRONT
REMAINS OFF TO THE WEST AROUND THE EASTERN GREAT LAKES.
HOWEVER...MOIST LOW LEVELS WITH PERSISTENTLY MOIST SOUTHERLY FLOW
WILL ALLOW FOR SOME MVFR CIGS/VSBY LATE TONIGHT...ESP FOR
KPSF/KPOU...WHERE WINDS ARE EXPECTED TO BECOME LIGHT/CALM.
SOME MORE SHOWERS WILL BE POSSIBLE WITH THE PASSAGE OF FRONTAL
BOUNDARY EARLY TUESDAY MORNING AS IT FINALLY REACHES OUR AREA FROM
THE WEST. SHOWERS SHOULD END BY THE LATE MORNING...AS COLD FRONT
PASSES THROUGH AND WINDS BECOME WEST...AND BECOME GUSTY. CIGS
SHOULD QUICKLY CLEAR OUT FOR ALL SITES BEHIND THE FRONT.
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. ISOLATED SHRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. WINDY. ISOLATED SHRA.
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
THURSDAY TO FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
FIRE WEATHER WATCH FOR BERKSHIRE COUNTY FROM 11 AM UNTIL 8 PM ON
TUESDAY.
A COLD FRONT OVER NORTHERN NEW YORK AND NEW ENGLAND WILL BRING
MORE WIDESPREAD CHANCES OF SHOWERS AND THUNDERSTORMS FROM THIS
AFTERNOON INTO TUESDAY BEFORE THE FRONT MOVES THROUGH OUR REGION.
VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH INCREASING
HUMIDITY LEVELS. THE COLD FRONTAL PASSAGE WILL USHER IN MUCH
COOLER AND DRIER AIR BY WEDNESDAY.
RELATIVE HUMIDITY VALUES WILL RECOVER TO 85 TO 100 PERCENT
TONIGHT...DROP TO 30 TO 45 PERCENT ON TUESDAY...RECOVER TO 70 TO
100 PERCENT TUESDAY NIGHT...AND DROP TO 35 TO 50 PERCENT ON
WEDNESDAY.
WINDS ARE EXPECTED TO BE SOUTH TO SOUTHEAST AT LESS THAN 15 MPH
TONIGHT AND WEST AT 10 TO 20 MPH WITH GUSTS TO 35 MPH BY TUESDAY
AFTERNOON THROUGH TUESDAY NIGHT AND NORTHWEST WINDS OF 10 TO 20
MPH WITH GUSTS TO 35 MPH ON WEDNESDAY.
&&
.HYDROLOGY...
THERE WILL BE GRADUALLY INCREASING CHANCES FOR SHOWERS AND
THUNDERSTORMS SPREADING SOUTH AND EAST THROUGH TUESDAY...AS A LOW
PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH AND EVENTUALLY MOVE
THROUGH THE REGION.
IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS.
THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH
THUNDERSTORMS ESPECIALLY THOSE WHICH TRAIN...ALTHOUGH RAINFALL
WILL BE BENEFICIAL IN MOST PLACES DUE TO VERY DRY ANTECEDENT
GROUND CONDITIONS. BASIN-AVERAGE RAINFALL WILL NOT BE UNIFORM DUE
TO THE CONVECTIVE NATURE OF THE PRECIPITATION. THE WESTERN MOHAWK
VALLEY...SOUTHERN ADIRONDACKS AND LAKE GEORGE SARATOGA REGION
HAVE THE BEST CHANCES TO SEE A HALF INCH TO INCH OF RAIN OR MORE THROUGH
TUESDAY. THE SCHOHARIE VALLEY...CAPITAL DISTRICT TO SOUTHERN
VERMONT AND POINTS SOUTH ARE EXPECTED TO GET A TENTH OF AN INCH
TO A THIRD OF AN INCH WITH LOCALIZED HIGHER AMOUNTS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY
EVENING FOR MAZ001-025.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/WASULA
SHORT TERM...11
LONG TERM...ELH
AVIATION...FRUGIS/11
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1007 PM EDT MON MAY 11 2015
.SYNOPSIS...
ANOTHER MILD AND HUMID NIGHT WITH DENSE FOG TONIGHT GIVES WAY TO
ANOTHER WARM DAY WITH SOME SHOWERS AND THUNDERSTORMS POSSIBLE IN
THE AFTERNOON AS THE REMNANTS OF ANA PASS BY. LARGE HIGH PRESSURE
WILL BUILD ACROSS THE EASTERN U.S. WITH DRIER WEATHER THROUGH THE
REMAINDER OF THE WEEK. AN APPROACHING WARM FRONT COULD BRING
SCATTERED SHOWERS NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
10 PM UPDATE...
BACKDOOR FRONT APPEARS TO HAVE STALLED FROM NE RI THROUGH
PORTIONS OF SE MA. TEMPS IN THE 50S TO THE N AND E OF THE FRONT
AND MAINLY 60S JUST TO THE S AND W. AS REMNANTS OF ANA APPROACHES
LATE TONIGHT...HI-RES GUIDANCE LIFTS THE FRONT BACK TO THE N
OVERNIGHT ACROSS RI AND SE MA.
AREAS OF DENSE FOG HAVE OVERSPREAD THE IMMEDIATE S COAST THIS
EVENING. WITH LOW LEVEL S/SW FLOW EXPECT DENSE FOG THREAT WILL BE
CONFINED TO THE S COAST AND SE MA...AND ALONG NE MA COAST WHERE
WINDS ARE EASTERLY. LATEST HRRR HAS LOWEST VSBYS ALONG THE S AND E
COASTS SO WE TRIMMED THE DENSE FOG ADVISORY AWAY FROM THE COAST.
FINALLY...HAVE INCREASED POPS ACROSS SE COASTAL MA AND CAPE COD
FOR LATE TONIGHT AS REMNANTS OF ANA TRACK TO THE SOUTH. MODELS
SHOW AREA OF DEEPER MOISTURE ALONG WITH SOME ELEVATED INSTABILITY
AT THE NOSE OF A LOW LEVEL JET WHICH SHOULD BRING AN AREA OF
SHOWERS OR AN ISOLD TSTM TO SE COASTAL NEW ENG. LATEST RAP SHOWS
AN AREA OF MEASURABLE RAINFALL LATE TONIGHT OVERSPREADING
PORTIONS OF RI AND SE MA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TOMORROW...
THE EARLY MORNING WILL BE MARKED BY A FAIRLY ROBUST DECK OF LOW
LVL CLOUDS AND FOG POSSIBLY AS FAR WEST AS THE CT VALLEY. THIS
WILL TAKE SOME TIME TO BURN OFF DURING THE MORNING AS DIURNAL
MIXING COMMENCES. EXACTLY HOW QUICKLY WILL DETERMINE THE THREAT
FOR CONVECTION/SEVERITY AS A COLD FRONT APPROACHES FOR THE
AFTERNOON.
BY AFTERNOON...AS THE FRONT MAKES IT/S PASS/APPROACH...SOME BREAKS
OF SUN ARE LIKELY ESPECIALLY FOR INTERIOR NRN MA AND WRN CT. THIS
AREA WILL BE THE PLACE TO WATCH AS BUFKIT PROFILES SHOW MODEST
CAPE VALUES APPROACHING 1000-1500 J/KG COMBINED WITH ABOUT 30 KT
OF 0-3KM SHEAR. UPPER LVL PROFILES WILL BE DRYING HOWEVER RATHER
QUICKLY SO IT/S A RACE AGAINST TIME AS TO WHETHER THE DRY AIR OR
INSTABILITY WINS AS THE LOW LVL F-GEN SOURCE APPROACHES. HI-RES
AND EVEN MORE COARSE GUIDANCE ALL SHOWING THE POSSIBILITY OF
AFTERNOON CONVECTIVE ACTIVITY WITH THE FROPA...ESPECIALLY NRN
INTERIOR MA AWAY FROM WHERE THE LOW LVL CLOUDS WILL HOLD IN.
SLIGHT CHANCE OF A STRONG STORM GIVEN THE MODEST SHEAR
VALUES...WHICH COINCIDES WELL WITH THE 18Z DAY TWO SWODY FROM
SPC...WHICH HIGHLIGHTS A MARGINAL RISK. THERE WILL STILL BE SOME
LEFTOVER LOW-LVL MOISTURE FROM ANA AHEAD OF THE FRONT...SO WILL
ALSO NEED TO WATCH FOR HEAVIER RAIN.
OTHER ISSUES FOR TOMORROW...
FIRE WEATHER CONCERNS...
AREAS WHERE THE CLOUD DISSIPATE WILL SEE LOW RELATIVE RH VALUES
AND GIVEN DIURNAL MIXING...WIND GUSTS OF 25-30 MPH AT TIMES.
THEREFORE...HAVE A MARGINAL RISK OF ELEVATED FIRE WEATHER DURING
THE DAY IN SPITE OF THE T-STORM/SHRA POTENTIAL. FOR MORE ON
THIS...SEE THE FIRE WEATHER SECTION BELOW.
HIGH SURF...
THE REMNANTS OF ANA WILL BRING 6 TO 10 FOOT SWELL TO OUR SOUTHERN
COASTAL WATERS TOMORROW. THIS WILL BRING HIGH SURF AND DANGEROUS
RIP CURRENTS TO OUR OCEAN EXPOSED SOUTH FACING BEACHES ON TUE.
GIVEN RELATIVELY WARM TEMPS EXPECTED...WE MAY STILL HAVE TO
CONSIDER A HIGH SURF ADVISORY EVEN THOUGH THE SUMMER SEASON HAS
NOT OFFICIAL BEGUN.
TUESDAY NIGHT...
FINALLY...THE HIGHER DWPTS...DRIER AIR AND IMPROVING CONDITIONS
WILL BE MOVING ACROSS THE REGION FROM W-E DURING THE OVERNIGHT
HOURS. LEFTOVER TSRA/SHRA WILL GENERALLY DIMINISH WITH THE LOSS OF
DIURNAL HEATING...SO THERE MAY BE A FEW CLOUDS STILL TO CONTEND
WITH EARLY. GIVEN THE MASS FIELDS ALSO SUPPORT A MODERATE PRES
GRADIENT...TEMPS ARE NOT LIKELY TO FALL AS LOW AS THEIR POTENTIAL
DESPITE THE DROPPING DWPTS. MINS MAINLY IN THE MID 40S AND LOW
50S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
* BREAK IN THE HEAT ON WEDNESDAY WITH NORMAL TEMPS
* HIGH PRESSURE ON THURS & FRI KEEP CONDITIONS DRY
* RAIN RELIEF POSSIBLE OVER THE WEEKEND WITH APPROACHING LOW
OVERVIEW...
FORECAST GUIDANCE CONTINUES TO BE IN GOOD AGREEMENT FOR MOST OF THE
EXTENDED. NOTICED 11.12Z GUIDANCE LEANED TOWARDS THE 11.00Z GFS FROM
LAST NIGHT IN BRINGING PRECIP INTO THE REGION FOR THE WEEKEND.
OTHERWISE BY LATE WEEKEND INTO EARLY NEXT WEEK APPEARS THAT THE EC
IS MORE AMPLIFIED IN BUILDING A STOUT RIDGE OVER NEW ENGLAND
COMPARED TO THE GFS. THIS COULD MAKE THINGS LESS STORMY THEN
PREVIOUSLY THOUGHT. APPEARS TEMPS WILL LEAN MORE TOWARDS OR JUST
ABOVE NORMAL OVER THE LONG TERM. COULD SEE AN INCREASE IN THE HEAT
BY NEXT WEEK.
DETAILS...
* WEDNESDAY...HIGH CONFIDENCE.
SECONDARY COLD FRONT WILL PASS THROUGH THE REGION PUSHING UPPER LEVEL
TROUGH OFFSHORE AND TEMPS ALOFT TO COOL OVER THE AREA. WINDS WILL
SWITCH TO A MORE NW FLOW...ALLOWING FOR GOOD DOWNSLOPING. PARTLY
SUNNY SKIES WILL ALLOW FOR TEMPS TO WARM INTO THE UPPER 60S...WHICH
IS NEAR NORMAL! DID LOWER DEWPOINTS AND INCREASE WIND GUSTS VERSUS
GUIDANCE AS MIXING ON WED WILL BE VERY GOOD. THIS WILL BRING A RISK
OF FIRE WEATHER CONCERNS TO THE REGION. DETAILS IN THE FIRE WEATHER
SECTION BELOW.
BECAUSE OF THE FALLING TEMPS ALOFT AND MARGINAL MOISTURE FIELD...
HAVE INSERTED A LOW CHANCE FOR AN ISOLATED SHOWER FOR FRANKLIN
COUNTY. CONFIDENCE IS LOW...BUT CANNOT RULE IT OUT.
TEMPS ALOFT WILL DROP THROUGHOUT THE DAY AND INTO THE OVERNIGHT
HOURS. IN FACT 850MB COULD DROP DOWN TO 0C OVERNIGHT. THIS COMBINED
WITH CLEAR SKIES AND DECOUPLE WINDS WILL ALLOW FOR RADIATIONAL
COOLING OVERNIGHT. TEMPS WILL DROP INTO THE LOWER 40S. COULD SEE A
FEW UPPER 30S BUT HAVE A LOW CONFIDENCE ON FROST DEVELOPMENT IN THE
VALLEY LOCALS ACROSS THE NW PORTION OF THE AREA.
* THURSDAY AND FRIDAY...HIGH CONFIDENCE.
HIGH PRESSURE WILL MOVE RIGHT ON IN FOR THURSDAY AND LAST INTO
FRIDAY. THIS WILL ALLOW FOR DRY WEATHER AND PLENTY OF SUNSHINE. HAVE
AN INCREASE CHANCE THAT SEA BREEZES WILL DEVELOP ACROSS THE
COASTLINES FOR BOTH DAYS. TEMPERATURES WILL WARM ABOVE AVERAGE ONCE
AGAIN...WITH HIGHS IN THE LOW 70S ON THURSDAY AND MID 70S ON FRIDAY
AWAY FROM THE COASTLINES.
* THE WEEKEND...MODERATE CONFIDENCE.
HIGH PRESSURE WILL MOVE SOUTH AND OFFSHORE ALLOWING FOR APPROACHING
LOW PRESSURE FROM THE WEST TO PUSH A WARM FRONT OVER THE REGION.
DEPENDING ON WHERE THIS WARM FRONT SETS UP WE COULD SEE A FEW ROUNDS
OF SHOWERS AS A WAVE OR TWO MOVES THROUGH THE AREA. NOT EXPECTING A
DROUGHT BUSTER AS WE NEED ABOUT 3-5 INCHES...BUT SOME RAIN RELIEF TO
THE REGION IS ANTICIPATED.
* MONDAY...LOW CONFIDENCE.
MONDAY IS LOOKING WARM BUT STILL UNCERTAIN ON PRECIP CHANCES AS THE
PATTERN WILL BE FOCUSED ON IF THE RIDGE WILL BUILD OR NOT.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH TONIGHT...MODERATE CONFIDENCE.
LIFR FOG HAS OVERSPREAD THE SOUTH COAST AS OF 02Z WITH IFR/LIFR
STRATUS FURTHER N ACROSS E COASTAL MA. EXPECT STRATUS TO EXPAND
ACROSS REST OF SNE OVERNIGHT...BUT DENSE FOG LIKELY CONFINED TO
COASTAL LOCATIONS. LATE NIGHT SHOWERS POSSIBLE...WHICH ACTUALLY
MAY ACT TO LIFT CONDITIONS BRIEFLY OUT OF IFR MAINLY IN RI AND SE
MA.
TOMORROW AND TOMORROW NIGHT...HIGH CONFIDENCE.
EARLY DAY...MIX OF LIFR/IFR IN THE MORNING GIVES WAY TO GRADUAL
IMPROVEMENT TO VFR THROUGH MID DAY. MAY TAKE UNTIL AFTERNOON TO
FULLY ERODE STRATUS IN SOME LOCATIONS. OTHERWISE...CHANCE OF AN
AFTERNOON SHOWER/T-STORM IN THE INTERIOR.
KBOS TAF...MODERATE CONFIDENCE. IFR CONDITIONS ARE LIKELY TO
PERSIST INTO TOMORROW MORNING FOR THE MOST PART. BRIEF LIFTS ARE
POSSIBLE. WINDS REMAIN NE THROUGH EARLY MORNING...AT WHICH POINT
THEY SHIFT BACK TO THE S.
KBDL TAF...MODERATE CONFIDENCE. VFR GIVES WAY TO IFR TONIGHT.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...HIGH CONFIDENCE.
WEDNESDAY...VFR. WINDS SWITCHING FROM SW TO NW AND INCREASING
CLOSE TO 25-30 KTS.
THURSDAY-FRIDAY...VFR. LIGHT AND VARIABLE WINDS. SEA BREEZES
POSSIBLE ON BOTH DAYS.
SATURDAY...VFR/MVFR WITH AN INCREASE IN SHOWERS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TUESDAY NIGHT/...
TONIGHT INTO TOMORROW...MODERATE CONFIDENCE.
LEFTOVER SWELL FROM ANA WILL BEGIN TO BUILD ALONG THE S COASTAL
WATERS LATE. REACHING A PEAK OF ABOUT 7-9 FT BY THE MID DAY
TOMORROW. SMALL CRAFT ADVISORIES CONTINUE FOR THIS THREAT.
OTHERWISE...WINDS REMAIN GENERALLY OUT OF THE S-SW UNTIL A COLD
FRONTAL PASSAGE TOMORROW LATE IN THE DAY...AT WHICH POINT THEY
SHIFT W.
THERE IS THE LOW THREAT FOR SOME THUNDERSTORMS...MAINLY ACROSS THE
E WATERS LATE IN THE DAY TOMORROW. FOG/STRATUS WILL ONCE AGAIN
YIELD NEAR ZERO VSBYS ACROSS THE WATERS TONIGHT INTO TOMORROW.
TOMORROW NIGHT...HIGH CONFIDENCE.
SLOW IMPROVEMENT AS WINDS SHIFT TO THE W. ANY SHOWERS/STORMS WILL
END AND SCOUR OUT THE LEFTOVER FOG. SEAS WILL ALSO GRADUALLY
DECLINE SUCH THAT SMALL CRAFT ADVISORIES MAY BE DROPPED BY THE
EARLY MORNING HOURS.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE.
WEDNESDAY...LINGERING 5FT SEAS WILL CONTINUE ON WED. HOWEVER GUSTS
WILL BE ON THE INCREASE TO 25 KTS ESP ACROSS THE INTERIOR
WATERS...SCA WILL BE NEEDED.
THURSDAY-FRIDAY...HIGH PRESSURE BUILDS OVER THE WATERS. WINDS AND
SEAS WILL BE BELOW SMALL CRAFT CRITERIA.
SATURDAY...WARM FRONT WILL PUSH OVER THE WATERS INCREASING PRECIP
CHANCES. BUT BOTH WINDS AND SEAS WILL REMAIN BELOW SCA.
&&
.FIRE WEATHER...
TOMORROW...TEMPERATURES MAY RISE TO NEAR 90 IN THE LOWER CT
VALLEY OF MA AND CT WITH DWPTS HOLDING IN THE 50S AND 60S. THERE
IS THE POSSIBILITY THEREFORE...THAT MIN RH VALUES WILL FALL TO
AROUND 25-35 PERCENT IN PORTIONS OF SW MA DURING THE DAY. SW WINDS
WILL GUST 25-30 MPH AT TIMES BY THE AFTERNOON. ALSO...THERE IS THE
THREAT FOR THUNDERSTORMS AND ACCUMULATING RAINFALL...BUT THESE
WILL GENERALLY BE HIT OR MISS AND WILL NOT PROVIDE THE WIDESPREAD
RAINFALL THAT MUCH OF THE REGION REQUIRES. A FIRE WEATHER WATCH
WILL BE ISSUED FOR SW PORTIONS OF MA DUE TO THE COLLOCATION OF
DRIEST RH VALUES...HIGHEST WINDS AND LOWEST THREAT FOR RAINFALL.
WEDNESDAY...A HIGHER RISK FOR FIRE WEATHER DEVELOPMENT IS EXPECTED
ON WEDNESDAY...HOWEVER IT WILL BE DEPENDENT ON PRECIP CHANCES OVER
THE NEXT 24-48 HOURS. SECONDARY COLD FRONT WILL PUSH THROUGH WED
MORNING ALLOWING FOR WINDS TO BE MORE OUT OF THE NW. THIS WILL
ALLOW FOR A DOWNSLOPING EFFECT...WHICH WILL INCREASE THE WIND
GUSTS AND LOWER DEWPOINTS. RIGHT NOW BELIEVE THAT RH VALUES WILL
DROP TO AROUND 30 PERCENT ACROSS MUCH OF THE REGION WITH NW WINDS
GUSTING TO NEAR 30 MPH. ONLY DIFFERENCE COMPARED TO THE PREVIOUS
DAYS IS HIGH TEMPS WILL WARM ONLY INTO THE UPPER 60S. HOWEVER
APPEARS THAT THERE WILL BE A GOOD AMOUNT OF SUNSHINE ACROSS MOST
OF THE REGION. WILL NEED TO CONTINUE TO MONITOR WEDNESDAY FOR
POSSIBLE HEADLINES.
THURSDAY AND FRIDAY...DRY WEATHER CONDITIONS WILL CONTINUE WITH RH
VALUES DROPPING WELL INTO THE 20 PERCENT LEVEL AND WITH FULL
SHINE. SINCE HIGH PRESSURE WILL BE OVERHEAD WIND WILL BE LIGHT AND
VARIABLE...GUSTS COULD REACH 10-15 MPH.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...DENSE FOG ADVISORY UNTIL 10 AM EDT TUESDAY FOR MAZ020>024.
DENSE FOG ADVISORY UNTIL 10 AM EDT TUESDAY FOR MAZ006-007-
014>016-018-019.
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR MAZ008>012.
RI...DENSE FOG ADVISORY UNTIL 10 AM EDT TUESDAY FOR RIZ005>008.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM TO 8 PM EDT TUESDAY FOR ANZ235-
237.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...DOODY/DUNTEN
NEAR TERM...KJC/DOODY
SHORT TERM...DOODY
LONG TERM...DUNTEN
AVIATION...DOODY/DUNTEN
MARINE...DOODY/DUNTEN
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS ALBANY NY
130 AM EDT SUN MAY 10 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT LAKES...
WILL APPROACH THROUGH SUNDAY AND MAY STALL ACROSS THE REGION INTO
EARLY NEXT WEEK. AS THE SYSTEM GETS CLOSER...CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL GRADUALLY INCREASE. THE BETTER CHANCES WILL
BE FROM THE CAPITAL DISTRICT NORTH AND WEST ON SUNDAY...WITH MORE
WIDESPREAD CHANCES MONDAY AND TUESDAY. VERY WARM TEMPERATURES WILL
REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 112 AM EDT...ISOLATED TO WIDELY SCATTERED SHOWERS REMAIN
WELL WEST OF OUR AREA AT THIS HOUR AND CONTINUING TO WEAKEN. THESE
SHOWERS ARE AHEAD OF WEAK DISTURBANCE IN ADVANCE OF A COLD FRONT.
LOCAL HI-RES WRF AND HRRR NOW INDICATING SHOWERS WILL NOT REACH
OUR AREA THROUGH THE REST OF THE NIGHT EXCEPT FOR AN ISOLATED
SHOWER OR TWO OVER THE WESTERN ADIRONDACKS.
ALSO WE HAVE ADDED PATCHY FOG TO THE MID HUDSON VALLEY...NW
CT...SE CATSKILLS AND SRN BERKSHIRES BTWN 06Z-12Z. THE LOW STRATUS
CONTINUES TO FORM AND MOVE NORTH FROM THE LOWER TO MID HUDSON
VALLEY AND SW NEW ENGLAND. EXPECT MOSTLY CLOUDY CONDITIONS FROM
THE HUDSON RIVER VALLEY EASTWARD BY DAYBREAK. LOWS TONIGHT WILL BE
VERY MILD FOR EARLY MAY IN THE MID 50S TO LOWER 60S ACROSS THE
FCST AREA. THESE MINS ARE A GOOD 10 TO 15 DEGREES ABOVE NORMAL. A
SOUTHERLY BREEZE WILL CONTINUE IN THE CAPITAL REGION WITH THE
FUNNELING EFFECT UP THE HUDSON VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
FOR SUNDAY THE COLD FRONT WILL DROP SOUTHWARD ACROSS THE NORTHERN
HALF OF THE AREA DURING THE DAY. THERE WILL BE SCATTERED SHOWERS
AND THUNDERSTORMS MAINLY NORTH AND WEST OF THE CAPITAL DISTRICT.
THERE IS A STRONG THETA E RIDGE IN PLACE ACROSS THE REGION WITH
CAPES OVER 1000 J/KG NORTH OF THE GREATER CAPITAL DISTRICT. UPPER
LEVEL Q VECTOR DIVERGENCE IS WEAK AS ARE HELICITY VALUES WHICH ARE
GENERALLY UNDER 100 M2/S2 SO NOT EXPECTING ANY SEVERE WEATHER ON
SUNDAY. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE AS PWATS
REACH ABOVE 1.50 INCHES ACROSS NORTHERN PORTIONS OF THE FA. HIGHS
SUNDAY AFTERNOON ARE EXPECTED TO RANGE FROM THE UPPER 70S
NORTHWEST TO MID 80S SOUTHEAST.
DESPITE LOSS OF DAYTIME HEATING WILL CONTINUE CHANCES FOR SHOWERS
AND THUNDERSTORMS SUNDAY NIGHT AS THE FRONTAL BOUNDARY WILL LIKELY
STALL OVER THE AREA. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 50S TO
MID 60S.
BY MONDAY THE FRONTAL BOUNDARY SHOULD BE STALLED ACROSS THE
CENTRAL PORTION OF OUR FA WITH A LOW PRESSURE SYSTEM MOVING
EASTWARD ALONG IT. THIS SHOULD BRING THE FIRST WIDESPREAD RAINFALL
TO OUR REGION IN NEARLY TWO WEEKS. THERE ARE SEVERAL KEY
INGREDIENTS IN PLACE WHICH SHOULD PROMOTE THUNDERSTORM ACTIVITY IN
ADDITION TO THE AFOREMENTIONED COLD FRONT. THERE WILL BE A STRONG
THETA E RIDGE ACROSS THE REGION ESPECIALLY DURING THE AFTERNOON
HOURS WHICH COUPLED WITH SB CAPES OF 500-1500 J/KG...PWATS 1.25
TO 1.75 INCHES AND 0-3 KM HELICITY OF 100-200 M2/S2. HIGHS ON
MONDAY SHOULD BE IN THE UPPER 60S TO LOWER 80S.
MONDAY NIGHT AND TUESDAY WILL CONTINUE TO BE VERY HUMID WITH HIGH
PWAT VALUES AT LEAST THROUGH THE FIRST HALF OF TUESDAY. THE
FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT LAKES
EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY HOURS
TO EARLY AFTERNOON AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA.
SO THE BEST CHANCES FOR CONVECTION LOOK TO BE LATE MONDAY NIGHT
THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT LOWS MONDAY NIGHT TO BE
IN THE UPPER 50S TO MID 60S WITH HIGHS ON TUESDAY IN THE 70S TO
AROUND 80.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE EXTENDED FORECAST FEATURES A RETURN TO MORE SEASONABLE TEMPS FOR
MID MAY FROM THE MIDDLE OF THE WEEK INTO NEXT WEEKEND WITH MAINLY
DRY WEATHER AFTER WEDNESDAY...AS A CANADIAN SFC HIGH BUILDS IN FOR
THU INTO THE WEEKEND.
TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE EAST OF THE
REGION BY TUESDAY EVENING ACCORDING TO THE MEDIUM RANGE GUIDANCE
/ECMWF...GFS...CAN GGEM/...AND MOST OF THE GEFS. HOWEVER...THE
UPPER LEVEL TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING
ACROSS MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW
CHC OF SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN
CATSKILLS...AND BERKSHIRES NORTHWARD. IT WILL BE MUCH COOLER BY WED
MORNING WITH H850 TEMPS FALLING TO +1C TO +4C FROM NW TO SE ACROSS
THE REGION...AND THIS IS BEFORE THE SFC TROUGH PASSAGE. THE COLD
ADVECTION WILL CONTINUE ON WED...AS IT WILL BE BRISK AND COOL. LOWS
WILL BE IN THE MID AND U40S OVER THE MTNS...AND LOWER TO MID 50S
ACROSS THE VALLEY AREAS. HIGHS WED WILL BE SLIGHTLY BELOW NORMAL
WITH U50S TO M60S IN THE VALLEY AREAS...AND U40S TO U50S OVER THE
HIGHER TERRAIN.
WED NIGHT INTO THU...THE TREND TO COOLER AND DRIER WEATHER
CONTINUES...AS THE SHOWERS WILL END BY SUNSET. IN THE COLD ADVECTION
REGIME THE GFS HAS H850 TEMPS LOWER TO -1C TO -4C OVER THE FCST
AREA. THESE H850 TEMPS ARE 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL
ACCORDING TO THE LATEST 12Z GEFS. THE SKIES WILL GRADUALLY
CLEAR...AND THE WINDS WILL BE LIGHTER THAN THU. LOWS WILL BE IN THE
40-45F RANGE IN THE CAPITAL DISTRICT...MID HUDSON VALLEY...SRN
TACONICS...ERN WINDHAM CTY VT...AND NW CT...AND MAINLY 30S ELSEWHERE
OVER THE W-CNTRL MOHAWK VALLEY...ERN CATSKILLS...SRN DACKS
REGION...LAKE GEORGE REGION...THE SRN GREENS AND BERKSHIRES. THERE
SHOULD BE ENOUGH WIND TO PRECLUDE ANY FROST ISSUES THURSDAY MORNING
WHERE THE GROWING SEASON HAS BEGIN. HIGHS ON THU WITH THE SFC HIGH
BUILDING IN FROM THE GREAT LAKES REGION WILL BE INN THE LOWER TO MID
60S IN THE VALLEYS...AND 50S OVER THE HIGHER TERRAIN. THE SFC HIGH
SHOULD HAVE PLENTY OF SUBSIDENCE WITH IT FOR MOSTLY SUNNY
CONDITIONS.
THU NIGHT INTO FRIDAY...THE SFC ANTICYCLONE BUILDS IN OVER THE
NORTHEAST WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS.
THIS WILL LIKELY BE THE COLDEST NIGHT WITH TEMPS IN THE U30S TO L40S
IN THE VALLEY AREAS...AND LOWER TO M30S OVER THE HIGHER TERRAIN.
SOME FROST ISSUES MAY ARISE IN A FEW SPOTS WHERE THE GROWING SEASON
HAS BEGIN. BY FRIDAY AFTERNOON...THE SFC HIGH MOVES OFF THE THE MID
ATLANTIC COAST...AND MID LEVEL HEIGHTS INCREASE OVER THE NORTHEAST.
ANOTHER NICE DAY IS EXPECTED WITH TEMPS NUDGING SLIGHTLY ABOVE
NORMAL WITH HIGHS IN THE U60S TO L70S IN THE VALLEY AREAS...AND
LOWER TO M60S OVER THE MTNS.
FRI NIGHT INTO SATURDAY...THE FAIR WEATHER LOOKS TO CONTINUE INTO
THE FIRST PART OF THE WEEKEND WITH THE MID-LEVEL RIDGE AXIS OVER NY
AND NEW ENGLAND. A WEAK SYSTEM TRIES TO APPROACH FROM THE TN AND OH
VALLEYS. MOST OF THE GUIDANCE KEEPS IT SOUTH AND WEST OF THE ALY
FCST AREA. A SLIGHT CHC OF SHOWERS WAS ADDED TO THE ERN
CATSKILLS/WRN MOHAWK VALLEY SAT PM...BUT OVERALL DRY WEATHER IS
EXPECTED TO START THE WEEKEND WITH TEMPS SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT WILL BECOME STATIONARY NORTH OF THE ST LAWRENCE RIVER
VALLEY TONIGHT WITH WEAK DISTURBANCES MOVING ALONG IT. THE FRONT
WILL SLOWLY BEGIN TO SAG SOUTH TOMORROW WITH INCREASED CHANCES OF
SHOWERS AND THUNDERSTORMS ESPECIALLY NORTH OF THE MOHAWK RIVER
VALLEY.
THE FORECAST AREA WILL REMAIN IN A WARM SECTOR THROUGH THE DAY.
IT WILL BE A WARM AND HUMID AIR MASS FOR MAY...AS LOW-LEVEL
MOISTURE CONTINUES TO INCREASE IN THE BOUNDARY LAYER. THE LOW-
LEVEL SOUTHERLY FLOW WILL SUPPORT LOW STRATUS AT ALL TAF SITES
THROUGH SUNRISE. THE CEILING BETWEEN 1000-3000 FEET WILL
OCCASIONALLY BE SCATTERED BUT PREDOMINANTLY BROKEN.
THE CEILING SHOULD DEVELOP AT KALB BETWEEN 06Z-09Z. AFTER 09Z...A
LAYER BELOW 1000 FEET COULD FORM...ESPECIALLY AT KPOU AND KPSF.
PUTTING A SCATTERED LAYER BELOW 1000 FEET AT ALL TAF SITES BUT
PUTTING INTERVALS OF A BROKEN CEILING BELOW 1000 FEET AT KPOU AND
KPSF. CAN AMEND FOR KALB AND KGFL IF A CEILING BELOW 1000 FEET
DEVELOPS THERE...WHICH IS LESS LIKELY THAN AT KPOU AND KPSF.
VISIBILITIES SHOULD LOWER TO MVFR IN LIGHT MIST AS WINDS BECOME
LIGHT...LESS THAN 5 KT AT ALL SITES EXCEPT KALB WHERE STEADY 6 TO
10 KT FROM THE SOUTH IS LIKELY THROUGH SUNRISE.
AFTER ABOUT 13Z...ALL CEILINGS AND VISIBILITIES SHOULD BECOME
VFR...BUT BROKEN CEILINGS ABOVE 3000 FEET ARE LIKELY AT ALL SITES
THROUGH THE DAY...WITH PERIODS OF SCATTERED. SOME ISOLATED TO
SCATTERED SHOWERS SHOULD BUILD INTO THE REGION THIS AFTERNOON AND
EVENING...BUT AGAIN...COVERAGE SHOULD BE SCATTERED AT BEST...SO
GOING VCSH AT KGFL...KALB AND KPSF. CONFIDENCE WAS NOT GREAT
ENOUGH TO ADD THUNDER TO THE TAF SITES YET.
THE WINDS WILL BE FROM THE SOUTH AT 5-12 KTS AT KALB...KGFL AND
KPSF BUT 5 KT OR LESS AT KPOU. WINDS WILL BECOME LIGHT TO CALM AT
KPSF/KGFL/KPOU...BUT DUE TO THE CHANNELING UP THE HUDSON RIVER
VALLEY EXPECT SOUTHERLY WINDS OF 6 TO 10 KTS AT KALB THROUGH
SUNRISE. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST TOMORROW AT
8-12 KTS WITH SOME GUSTS AROUND 20 KTS AT KALB. WINDS WILL
DIMINISH TO 8 KT OR LESS THIS EVENING.
OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY-THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
HAVE ISSUED A SPS FOR BERKSHIRE AND LITCHFIELD COUNTIES FOR
ELEVATED FIRE WEATHER POTENTIAL FOR SUNDAY.
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT
LAKES...WILL APPROACH OUR REGION THROUGH SUNDAY AND MAY STALL
ACROSS THE REGION INTO EARLY NEXT WEEK. AS THE SYSTEM GETS
CLOSER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL GRADUALLY
INCREASE. THE BETTER CHANCES WILL BE FROM THE CAPITAL DISTRICT
NORTH AND WEST ON SUNDAY...WITH MORE WIDESPREAD CHANCES MONDAY AND
TUESDAY. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH
INCREASING HUMIDITY LEVELS.
RELATIVE HUMIDITIES WILL RISE TO 80 TO 100 PERCENT TONIGHT...FALL
TO 35 TO 55 PERCENT ON SUNDAY...RISE TO 85 TO 100 PERCENT ON
SUNDAY NIGHT AND FALL TO 45 TO 65 PERCENT ON MONDAY.
WINDS WILL BE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TONIGHT AND
SUNDAY...SOUTH 5 TO 10 MPH SUNDAY NIGHT AND SOUTH AROUND 5 MPH ON
MONDAY.
&&
.HYDROLOGY...
DRY WEATHER LOOKS TO PERSIST THROUGH MUCH OF TONIGHT...WITH
GRADUALLY INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
SPREADING SOUTH AND EAST FROM SUNDAY THROUGH EARLY NEXT WEEK AS A
LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH AND EVENTUALLY
MOVE THROUGH.
IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS.
THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH
THUNDERSTORMS...ALTHOUGH RAINFALL WILL BE BENEFICIAL IN MOST
PLACES DUE TO VERY DRY ANTECEDENT GROUND CONDITIONS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/JPV
NEAR TERM...JPV/WASULA
SHORT TERM...11
LONG TERM...WASULA
AVIATION...NAS
FIRE WEATHER...11
HYDROLOGY...IAA/11/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
112 AM EDT SUN MAY 10 2015
.SYNOPSIS...
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT LAKES...
WILL APPROACH THROUGH SUNDAY AND MAY STALL ACROSS THE REGION INTO
EARLY NEXT WEEK. AS THE SYSTEM GETS CLOSER...CHANCES FOR SHOWERS
AND THUNDERSTORMS WILL GRADUALLY INCREASE. THE BETTER CHANCES WILL
BE FROM THE CAPITAL DISTRICT NORTH AND WEST ON SUNDAY...WITH MORE
WIDESPREAD CHANCES MONDAY AND TUESDAY. VERY WARM TEMPERATURES WILL
REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 112 AM EDT...ISOLATED TO WIDELY SCATTERED SHOWERS REMAIN
WELL WEST OF OUR AREA AT THIS HOUR AND CONTINUING TO WEAKEN. THESE
SHOWERS ARE AHEAD OF WEAK DISTURBANCE IN ADVANCE OF A COLD FRONT.
LOCAL HI-RES WRF AND HRRR NOW INDICATING SHOWERS WILL NOT REACH
OUR AREA THROUGH THE REST OF THE NIGHT EXCEPT FOR AN ISOLATED
SHOWER OR TWO OVER THE WESTERN ADIRONDACKS.
ALSO WE HAVE ADDED PATCHY FOG TO THE MID HUDSON VALLEY...NW
CT...SE CATSKILLS AND SRN BERKSHIRES BTWN 06Z-12Z. THE LOW STRATUS
CONTINUES TO FORM AND MOVE NORTH FROM THE LOWER TO MID HUDSON
VALLEY AND SW NEW ENGLAND. EXPECT MOSTLY CLOUDY CONDITIONS FROM
THE HUDSON RIVER VALLEY EASTWARD BY DAYBREAK. LOWS TONIGHT WILL BE
VERY MILD FOR EARLY MAY IN THE MID 50S TO LOWER 60S ACROSS THE
FCST AREA. THESE MINS ARE A GOOD 10 TO 15 DEGREES ABOVE NORMAL. A
SOUTHERLY BREEZE WILL CONTINUE IN THE CAPITAL REGION WITH THE
FUNNELING EFFECT UP THE HUDSON VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
FOR SUNDAY THE COLD FRONT WILL DROP SOUTHWARD ACROSS THE NORTHERN
HALF OF THE AREA DURING THE DAY. THERE WILL BE SCATTERED SHOWERS
AND THUNDERSTORMS MAINLY NORTH AND WEST OF THE CAPITAL DISTRICT.
THERE IS A STRONG THETA E RIDGE IN PLACE ACROSS THE REGION WITH
CAPES OVER 1000 J/KG NORTH OF THE GREATER CAPITAL DISTRICT. UPPER
LEVEL Q VECTOR DIVERGENCE IS WEAK AS ARE HELICITY VALUES WHICH ARE
GENERALLY UNDER 100 M2/S2 SO NOT EXPECTING ANY SEVERE WEATHER ON
SUNDAY. SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE AS PWATS
REACH ABOVE 1.50 INCHES ACROSS NORTHERN PORTIONS OF THE FA. HIGHS
SUNDAY AFTERNOON ARE EXPECTED TO RANGE FROM THE UPPER 70S
NORTHWEST TO MID 80S SOUTHEAST.
DESPITE LOSS OF DAYTIME HEATING WILL CONTINUE CHANCES FOR SHOWERS
AND THUNDERSTORMS SUNDAY NIGHT AS THE FRONTAL BOUNDARY WILL LIKELY
STALL OVER THE AREA. LOWS SUNDAY NIGHT WILL BE IN THE UPPER 50S TO
MID 60S.
BY MONDAY THE FRONTAL BOUNDARY SHOULD BE STALLED ACROSS THE
CENTRAL PORTION OF OUR FA WITH A LOW PRESSURE SYSTEM MOVING
EASTWARD ALONG IT. THIS SHOULD BRING THE FIRST WIDESPREAD RAINFALL
TO OUR REGION IN NEARLY TWO WEEKS. THERE ARE SEVERAL KEY
INGREDIENTS IN PLACE WHICH SHOULD PROMOTE THUNDERSTORM ACTIVITY IN
ADDITION TO THE AFOREMENTIONED COLD FRONT. THERE WILL BE A STRONG
THETA E RIDGE ACROSS THE REGION ESPECIALLY DURING THE AFTERNOON
HOURS WHICH COUPLED WITH SB CAPES OF 500-1500 J/KG...PWATS 1.25
TO 1.75 INCHES AND 0-3 KM HELICITY OF 100-200 M2/S2. HIGHS ON
MONDAY SHOULD BE IN THE UPPER 60S TO LOWER 80S.
MONDAY NIGHT AND TUESDAY WILL CONTINUE TO BE VERY HUMID WITH HIGH
PWAT VALUES AT LEAST THROUGH THE FIRST HALF OF TUESDAY. THE
FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT LAKES
EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY HOURS
TO EARLY AFTERNOON AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA.
SO THE BEST CHANCES FOR CONVECTION LOOK TO BE LATE MONDAY NIGHT
THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT LOWS MONDAY NIGHT TO BE
IN THE UPPER 50S TO MID 60S WITH HIGHS ON TUESDAY IN THE 70S TO
AROUND 80.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE EXTENDED FORECAST FEATURES A RETURN TO MORE SEASONABLE TEMPS FOR
MID MAY FROM THE MIDDLE OF THE WEEK INTO NEXT WEEKEND WITH MAINLY
DRY WEATHER AFTER WEDNESDAY...AS A CANADIAN SFC HIGH BUILDS IN FOR
THU INTO THE WEEKEND.
TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE EAST OF THE
REGION BY TUESDAY EVENING ACCORDING TO THE MEDIUM RANGE GUIDANCE
/ECMWF...GFS...CAN GGEM/...AND MOST OF THE GEFS. HOWEVER...THE
UPPER LEVEL TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING
ACROSS MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW
CHC OF SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN
CATSKILLS...AND BERKSHIRES NORTHWARD. IT WILL BE MUCH COOLER BY WED
MORNING WITH H850 TEMPS FALLING TO +1C TO +4C FROM NW TO SE ACROSS
THE REGION...AND THIS IS BEFORE THE SFC TROUGH PASSAGE. THE COLD
ADVECTION WILL CONTINUE ON WED...AS IT WILL BE BRISK AND COOL. LOWS
WILL BE IN THE MID AND U40S OVER THE MTNS...AND LOWER TO MID 50S
ACROSS THE VALLEY AREAS. HIGHS WED WILL BE SLIGHTLY BELOW NORMAL
WITH U50S TO M60S IN THE VALLEY AREAS...AND U40S TO U50S OVER THE
HIGHER TERRAIN.
WED NIGHT INTO THU...THE TREND TO COOLER AND DRIER WEATHER
CONTINUES...AS THE SHOWERS WILL END BY SUNSET. IN THE COLD ADVECTION
REGIME THE GFS HAS H850 TEMPS LOWER TO -1C TO -4C OVER THE FCST
AREA. THESE H850 TEMPS ARE 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL
ACCORDING TO THE LATEST 12Z GEFS. THE SKIES WILL GRADUALLY
CLEAR...AND THE WINDS WILL BE LIGHTER THAN THU. LOWS WILL BE IN THE
40-45F RANGE IN THE CAPITAL DISTRICT...MID HUDSON VALLEY...SRN
TACONICS...ERN WINDHAM CTY VT...AND NW CT...AND MAINLY 30S ELSEWHERE
OVER THE W-CNTRL MOHAWK VALLEY...ERN CATSKILLS...SRN DACKS
REGION...LAKE GEORGE REGION...THE SRN GREENS AND BERKSHIRES. THERE
SHOULD BE ENOUGH WIND TO PRECLUDE ANY FROST ISSUES THURSDAY MORNING
WHERE THE GROWING SEASON HAS BEGIN. HIGHS ON THU WITH THE SFC HIGH
BUILDING IN FROM THE GREAT LAKES REGION WILL BE INN THE LOWER TO MID
60S IN THE VALLEYS...AND 50S OVER THE HIGHER TERRAIN. THE SFC HIGH
SHOULD HAVE PLENTY OF SUBSIDENCE WITH IT FOR MOSTLY SUNNY
CONDITIONS.
THU NIGHT INTO FRIDAY...THE SFC ANTICYCLONE BUILDS IN OVER THE
NORTHEAST WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS.
THIS WILL LIKELY BE THE COLDEST NIGHT WITH TEMPS IN THE U30S TO L40S
IN THE VALLEY AREAS...AND LOWER TO M30S OVER THE HIGHER TERRAIN.
SOME FROST ISSUES MAY ARISE IN A FEW SPOTS WHERE THE GROWING SEASON
HAS BEGIN. BY FRIDAY AFTERNOON...THE SFC HIGH MOVES OFF THE THE MID
ATLANTIC COAST...AND MID LEVEL HEIGHTS INCREASE OVER THE NORTHEAST.
ANOTHER NICE DAY IS EXPECTED WITH TEMPS NUDGING SLIGHTLY ABOVE
NORMAL WITH HIGHS IN THE U60S TO L70S IN THE VALLEY AREAS...AND
LOWER TO M60S OVER THE MTNS.
FRI NIGHT INTO SATURDAY...THE FAIR WEATHER LOOKS TO CONTINUE INTO
THE FIRST PART OF THE WEEKEND WITH THE MID-LEVEL RIDGE AXIS OVER NY
AND NEW ENGLAND. A WEAK SYSTEM TRIES TO APPROACH FROM THE TN AND OH
VALLEYS. MOST OF THE GUIDANCE KEEPS IT SOUTH AND WEST OF THE ALY
FCST AREA. A SLIGHT CHC OF SHOWERS WAS ADDED TO THE ERN
CATSKILLS/WRN MOHAWK VALLEY SAT PM...BUT OVERALL DRY WEATHER IS
EXPECTED TO START THE WEEKEND WITH TEMPS SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT WILL BECOME STATIONARY NORTH OF THE ST LAWRENCE RIVER
VALLEY TONIGHT WITH WEAK DISTURBANCES MOVING ALONG IT. THE FRONT
WILL SLOWLY BEGIN TO SAG SOUTH TOMORROW WITH INCREASED CHANCES OF
SHOWERS AND THUNDERSTORMS ESPECIALLY NORTH OF THE MOHAWK RIVER
VALLEY.
THE FORECAST AREA WILL REMAIN IN A WARM SECTOR TONIGHT. IT WILL BE
A WARM AND HUMID AIR MASS FOR MAY...AS LOW-LEVEL MOISTURE
CONTINUES TO INCREASE IN THE BOUNDARY LAYER. THE LOW-LEVEL
SOUTHERLY FLOW WILL ALLOW LOW STRATUS TO FORM FOR
KPOU...KPSF...KGFL...AND KALB TONIGHT. THE LOW STRATUS IS EXPECTED
TO FORM BTWN 03Z-06Z WITH MVFR CONDITIONS WITH CIGS BTWN 1-1.5 KFT
AGL. EXPECT THE CIGS TO LOWER TO IFR LEVELS WITH SOME MIST AT KPOU
AND KPSF PRIOR TO OR AROUND 06Z. THE IFR CIGS AND VSBYS WILL LAST
UNTIL 12Z-15Z AT THESE SITES. IT IS TOUGH TO DISCERN IF KALB WILL
HAVE IFR CIGS DUE TO A STEADY SOUTHERLY BREEZE UP THE HUDSON RIVER
VALLEY...SO LOW MVFR CIGS WERE LEFT THERE. KGFL...THE WINDS ARE
EXPECTED TO BECOME LIGHT TO CALM...AND IFR CIGS/VSBYS HAVE BEEN
FORECASTED FROM 09Z-13Z.
THE STRATUS WILL ERODE BELOW THE LOW-LEVEL INVERSION IN THE LATE
MORNING WITH CIGS/VSBYS RISING BACK TO VFR LEVELS DUE TO SOME
SUNSHINE AND MIXING. HOWEVER...MID CLOUDS WILL INCREASE AND THE
THREAT FOR SOME SCT SHOWERS AND THUNDERSTORMS WELL IN ADVANCE OF
THE COLD FRONT. VCSH GROUPS WERE ADDED TO KGFL/KALB/KPSF BTWN
18Z-21Z. OUR CONFIDENCE WAS NOT GREAT ENOUGH TO ADD THUNDER TO THE
TAF SITES YET.
THE WINDS WILL BE FROM THE SOUTH AT 5-12 KTS EARLY TONIGHT...AND
THEY WILL BECOME LIGHT TO CALM AT KPSF/KGFL/KPOU...BUT DUE TO THE
CHANNELING UP THE HUDSON RIVER VALLEY EXPECT SOUTHERLY WINDS OF
AROUND 10 KTS AT KALB THROUGHOUT THE NIGHT. THE WINDS WILL BE FROM
THE SOUTH TO SOUTHWEST TOMORROW AT 8-12 KTS WITH SOME GUSTS AROUND
20 KTS AT KALB.
OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY-THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
HAVE ISSUED A SPS FOR BERKSHIRE AND LITCHFIELD COUNTIES FOR
ELEVATED FIRE WEATHER POTENTIAL FOR SUNDAY.
A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY OVER THE GREAT
LAKES...WILL APPROACH OUR REGION THROUGH SUNDAY AND MAY STALL
ACROSS THE REGION INTO EARLY NEXT WEEK. AS THE SYSTEM GETS
CLOSER...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL GRADUALLY
INCREASE. THE BETTER CHANCES WILL BE FROM THE CAPITAL DISTRICT
NORTH AND WEST ON SUNDAY...WITH MORE WIDESPREAD CHANCES MONDAY AND
TUESDAY. VERY WARM TEMPERATURES WILL REMAIN IN PLACE WITH
INCREASING HUMIDITY LEVELS.
RELATIVE HUMIDITIES WILL RISE TO 80 TO 100 PERCENT TONIGHT...FALL
TO 35 TO 55 PERCENT ON SUNDAY...RISE TO 85 TO 100 PERCENT ON
SUNDAY NIGHT AND FALL TO 45 TO 65 PERCENT ON MONDAY.
WINDS WILL BE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TONIGHT AND
SUNDAY...SOUTH 5 TO 10 MPH SUNDAY NIGHT AND SOUTH AROUND 5 MPH ON
MONDAY.
&&
.HYDROLOGY...
DRY WEATHER LOOKS TO PERSIST THROUGH MUCH OF TONIGHT...WITH
GRADUALLY INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS
SPREADING SOUTH AND EAST FROM SUNDAY THROUGH EARLY NEXT WEEK AS A
LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH AND EVENTUALLY
MOVE THROUGH.
IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS.
THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH
THUNDERSTORMS...ALTHOUGH RAINFALL WILL BE BENEFICIAL IN MOST
PLACES DUE TO VERY DRY ANTECEDENT GROUND CONDITIONS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/JPV
NEAR TERM...JPV/WASULA
SHORT TERM...11
LONG TERM...WASULA
AVIATION...WASULA
FIRE WEATHER...11
HYDROLOGY...IAA/11/JPV
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
950 AM EDT SUN MAY 10 2015
.DISCUSSION...
TODAY...ANA WILL DRIFT NORTH ACROSS THE CAROLINAS...CONTINUING THE
SLOW MIGRATION OF THE LOW LEVEL ATLANTIC RIDGE NORTHWARD. EARLY
MORNING VISIBLE SATELLITE IMAGERY CLEARLY SHOWED CLOUD LINES
DELINEATING THE RIDGE AXIS ACROSS THE NORTHERNMOST BAHAMAS.
MORNING SOUNDINGS AND GPS PRECIPITABLE WATER DATA SHOWED MOISTENING
AT MIAMI BUT DRIER AIR LINGERING FROM TAMPA TO OKEECHOBEE. THE GFS
MOVES THIS DRIER RIBBON NORTHWARD AND INCREASES MOISTURE CONVERGENCE
IN OUR SOUTHERN AREAS...WHILE DECREASING MOISTURE ACROSS THE NORTH.
THEREFORE...EXPECT A SLIGHT CHANCE FOR STORMS ALONG THE INLAND
MOVING SEA BREEZE FROM THE TREASURE COAST TO OKEECHOBEE AND SOUTH
OSCEOLA. THIS FITS THE 12Z HRRR MODEL AND THE TYPICAL PATTERN OF
HIGHER MOISTURE CONVERGENCE ZONE OCCURRING JUST NORTH OF THE RIDGE
AXIS.
ANY SHOWER/STORM CHANCES ACROSS THE NORTH WILL BE LATE AND WELL
INLAND WITH THE EAST/WEST COAST SEA BREEZE COLLISION.
WILL NOT CHANGE THE CURRENT FORECAST THAT DEPICTS LOW THRESHOLD
POPS. TEMPS ALOFT ARE QUITE COOL THOUGH...SO WHERE THE GREATEST
BOUNDARY COLLISIONS OCCUR...STRONG STORMS ARE POSSIBLE.
&&
.AVIATION...MAINLY VFR. ONLY A SLIGHT CHANCE FOR STORMS MAINLY
INLAND BETWEEN KMLB-KSUA AND PROBABLY SOUTH OF KMCO/KISM. LIGHT WIND
REGIME...EXCEPT KMLB-KSUA WHERE THE SEA BREEZE SHOULD BE GUSTY TO
NEAR 20 KNOTS.
&&
.MARINE...
TODAY-TONIGHT...ATLANTIC HIGH PRESSURE RIDGE AXIS WILL CONTINUE TO
MIGRATE SLOWLY NORTHWARD FROM THE NORTHERN BAHAMAS. THIS WILL
PRODUCE A SOUTHERLY WIND FLOW...MAINLY AROUND 10 KNOTS. DIURNAL
INCREASES TO 15 KNOTS WILL OCCUR WITH THE SEA BREEZE NEAR SHORE AND
OFFSHORE OVERNIGHT. SO OVERALL THERE WILL BE A LITTLE MORE WIND
WAVE COMPARED TO THE LAST COUPLE DAYS. SMALL CHANCES FOR SHOWERS AND
STORMS WILL EXIST ON ATLANTIC CLOUD LINES INTO TONIGHT.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...WEITLICH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1046 AM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1045 AM CDT SUN MAY 10 2015
WILL UPDATE THE FORECAST LATE THIS MORNING FOR SOME ADJUSTMENT TO
CHANCES OF SHOWERS AND THUNDERSTORMS REST OF THE DAY...AS
CONVECTION AS BEEN MORE WIDELY SCATTERED THIS MORNING. ALSO HAVE
LINGERING FOG OVER NORTHERN COUNTIES NORTH OF WARM FRONT AND
LOCALLY DENSE THIS MORNING. THE WARM FRONT CURRENTLY WAS SLOWLY
LIFTING NORTH AND WAS SOUTH OF MACOMB AND PEORIA AND JUST PASSED
NORTH OF BLOOMINGTON AIRPORT A HALF HOUR AGO. THE FRONT WILL
SLOWLY PUSH NORTH ACROSS NORTHERN COUNTIES THIS AFTERNOON AND THIS
AREA WILL HAVE BEST CHANCES OF DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS IN WARM/HUMID AIRMASS. ANOTHER AREA OF CONVECTION
WILL SPREAD NE ACROSS CENTRAL IL DURING THE EVENING. SPC CONTINUES
SLIGHT RISK OF SEVERE STORMS LATER THIS AFTERNOON AND EVENING
ACROSS MUCH OF CENTRAL IL ESPECIALLY FROM I-57 WEST WHERE CAPES
GET TO 1500-2500 J/KG BY 00Z/7 PM CENTRAL AND WESTERN CWA AND BULK
SHEAR TO 25-35 KTS WESTERN CWA BY SUNSET. HIGHS TO RANGE FROM LOW
TO MID 70S FAR NORTHERN 3 COUNTIES OF KNOX...STARK AND MARSHALL...
TO THE UPPER 70S AND LOWER 80S FROM PEORIA SOUTH.
&&
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF
MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF
10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE
SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR
WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE
CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN
CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE
SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING
THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER
SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC
SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI.
GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT
RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS
MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE
AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE
CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA
STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON.
BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS
SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF
MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE
AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE
SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT
EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER
GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY
DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL
DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE
CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST
ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS
DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS
THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE
SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND
HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH
TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS
WILL TOP THE 80 DEGREE MARK.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS
EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL
TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING
INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS
THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS
ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE
MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN
PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA
MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING
FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE
AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED
POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON.
ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE
60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL
BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF
ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND
INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL
SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE
SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24
HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE
CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE
GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO
THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 600 AM CDT SUN MAY 10 2015
A WARM FRONT...CURRENTLY LOCATED FROM JUST NORTH OF KSPI AND KCMI
WILL EDGE NORTHWARD TODAY WITH MOSTLY LIFR TO VLIFR CIGS AND VSBYS
TO ITS NORTH...WHILE MVFR AND VFR CIGS WERE PREVALENT TO ITS
SOUTH THIS MORNING. HOW QUICKLY THE CIGS AND VSBYS IMPROVE AS THE
FRONT MOVES NORTH WILL BE THE PRIMARY CONCERN EARLY ON DURING THIS
FORECAST PERIOD...WITH TIMING OF STRONG TO LOCALLY SEVERE STORMS
AFTER 20Z THE NEXT CONCERN DURING THE SECOND HALF OF THE FORECAST
PERIOD. WITH MOST OF THE SHORT TERM MODELS NOT PUSHING THE FRONT
TO THE NORTH OF THE TAF SITES BY EARLY THIS AFTERNOON...WILL BRING
CIGS AND VSBYS UP IN THE AREAS NORTH OF THE FRONT THIS MORNING
WHILE MVFR TO LOW VFR CIGS EXPECTED OVER THE REMAINDER OF THE
TAF SITES THIS AFTERNOON. BASED ON THE LATEST SOUNDING DATA...
IT APPEARS BASES WILL IMPROVE TO SCT-BKN CIGS FROM AROUND 2500-3500
FEET BY EARLY THIS AFTERNOON.
CONVECTION LOOKS TO DEVELOP OVER PARTS OF CENTRAL AND SOUTH
CENTRAL MISSOURI BY THIS AFTERNOON AND PUSH EAST AND NORTHEAST
INTO OUR FORECAST AREA BETWEEN 21Z AND 00Z AND LAST THRU ABOUT
05Z BEFORE TAPERING OFF TO SHOWERS FOR THE REMAINDER OF THE
TIME PERIOD. SURFACE WINDS WILL BE EASTERLY AT 5 TO 12 KTS
NORTH OF THE WARM FRONT FOR THE NEXT SEVERAL HOURS...BUT MOST
AREAS SHOULD SEE SOUTH TO SOUTHEAST WINDS AT 10 TO 15 KTS TODAY
WITH SOUTHEASTERLY FLOW EXPECTED TONIGHT AT 8 TO 15 KTS...WHICH
SHOULD BECOME SOUTH LATE TONIGHT AT 12 TO 17 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
605 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF
MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF
10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE
SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR
WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE
CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN
CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE
SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING
THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER
SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC
SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI.
GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT
RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS
MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE
AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE
CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA
STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON.
BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS
SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF
MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE
AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE
SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT
EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER
GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY
DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL
DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE
CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST
ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS
DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS
THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE
SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND
HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH
TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS
WILL TOP THE 80 DEGREE MARK.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS
EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL
TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING
INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS
THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS
ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE
MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN
PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA
MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING
FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE
AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED
POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON.
ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE
60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL
BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF
ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND
INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL
SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE
SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24
HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE
CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE
GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO
THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 600 AM CDT SUN MAY 10 2015
A WARM FRONT...CURRENTLY LOCATED FROM JUST NORTH OF KSPI AND KCMI
WILL EDGE NORTHWARD TODAY WITH MOSTLY LIFR TO VLIFR CIGS AND VSBYS
TO ITS NORTH...WHILE MVFR AND VFR CIGS WERE PREVALENT TO ITS
SOUTH THIS MORNING. HOW QUICKLY THE CIGS AND VSBYS IMPROVE AS THE
FRONT MOVES NORTH WILL BE THE PRIMARY CONCERN EARLY ON DURING THIS
FORECAST PERIOD...WITH TIMING OF STRONG TO LOCALLY SEVERE STORMS
AFTER 20Z THE NEXT CONCERN DURING THE SECOND HALF OF THE FORECAST
PERIOD. WITH MOST OF THE SHORT TERM MODELS NOT PUSHING THE FRONT
TO THE NORTH OF THE TAF SITES BY EARLY THIS AFTERNOON...WILL BRING
CIGS AND VSBYS UP IN THE AREAS NORTH OF THE FRONT THIS MORNING
WHILE MVFR TO LOW VFR CIGS EXPECTED OVER THE REMAINDER OF THE
TAF SITES THIS AFTERNOON. BASED ON THE LATEST SOUNDING DATA...
IT APPEARS BASES WILL IMPROVE TO SCT-BKN CIGS FROM AROUND 2500-3500
FEET BY EARLY THIS AFTERNOON.
CONVECTION LOOKS TO DEVELOP OVER PARTS OF CENTRAL AND SOUTH
CENTRAL MISSOURI BY THIS AFTERNOON AND PUSH EAST AND NORTHEAST
INTO OUR FORECAST AREA BETWEEN 21Z AND 00Z AND LAST THRU ABOUT
05Z BEFORE TAPERING OFF TO SHOWERS FOR THE REMAINDER OF THE
TIME PERIOD. SURFACE WINDS WILL BE EASTERLY AT 5 TO 12 KTS
NORTH OF THE WARM FRONT FOR THE NEXT SEVERAL HOURS...BUT MOST
AREAS SHOULD SEE SOUTH TO SOUTHEAST WINDS AT 10 TO 15 KTS TODAY
WITH SOUTHEASTERLY FLOW EXPECTED TONIGHT AT 8 TO 15 KTS...WHICH
SHOULD BECOME SOUTH LATE TONIGHT AT 12 TO 17 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
329 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF
MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF
10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE
SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR
WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE
CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN
CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE
SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING
THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER
SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC
SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI.
GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT
RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS
MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE
AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE
CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA
STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON.
BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS
SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF
MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE
AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE
SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT
EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER
GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY
DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL
DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE
CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST
ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS
DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS
THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE
SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND
HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH
TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS
WILL TOP THE 80 DEGREE MARK.
&&
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS
EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL
TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING
INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS
THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS
ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE
MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN
PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA
MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING
FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE
AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED
POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON.
ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE
60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL
BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF
ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND
INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL
SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE
SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24
HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE
CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE
GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO
THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1200 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL CONTINUE OVERNIGHT THROUGH ALL TAFS, SO
WILL KEEP VCSH AT ALL TAFS THROUGH MORNING HOURS. AREA OF
CONVECTION IN OK/ARK/SRN MO WILL MOVE ENE ACROSS SOUTHERN IL
OVERNIGHT AND SHOULD REMAIN SOUTH OF THE TAFS. COULD BE SOME
LINGERING SHOWERS REACH UP INTO THE AREA, BUT WILL NOT INCLUDE
ANYTHING FOR NOW. MORE PCPN IS POSSIBLE TONIGHT SO WILL HAVE VCTS
IN TAFS STARTING LATE AFTERNOON THROUGH EVENING HOURS. NOT SURE
WHEN A TEMPO GROUP FOR THUNDERSTORMS IS WARRANTED SO WILL LEAVE
OUT FOR NOW. IFR CONDITIONS HAVE MOVED INTO THE AREA AT ALL SITES
AND WILL LIKELY CONTINUE OVERNIGHT. THEN BY MORNING CIGS WILL
IMPROVE INTO THE MVFR CATEGORY. BY EVENING WHEN THE STORMS WILL BE
AROUND, VFR CONDITIONS WILL PREVAIL. WINDS WILL BE NORTHEAST AT
PIA/BMI WHICH ARE NORTH OF THE FRONT FOR NOW. SOUTH TO SOUTHEAST
WINDS WILL PREVAIL AT SPI/DEC/CMI. PIA AND BMI WILL SEE WINDS
BECOME SOUTHERLY DURING THE AFTERNOON/EVENING AS THE FRONT LIFTS
NORTH OF THE SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1200 AM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 901 PM CDT SAT MAY 9 2015
SCATTERED SHOWERS CONTINUE ACROSS THE AREA THIS EVENING AND WITH
REMNANTS OF ANOTHER MCS COMING IN FOR LATER TONIGHT...SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE OVERNIGHT. SKIES
WILL REMAIN MOSTLY CLOUDY SO DO NOT THINK MUCH FOG WILL OCCUR LATE
TONIGHT LIKE LAST NIGHT. CLOUDS WILL KEEP TEMPS UP AS WELL AND
CURRENT FORECAST LOW LOOKS FINE. GIVEN RADAR TRENDS HAVE MADE SOME
ADJUSTMENTS TO THE POP/WX GRIDS. SO UPDATE WILL BE COMING SHORTLY.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 251 PM CDT SAT MAY 9 2015
A QUASI-STATIONARY FRONTAL BOUNDARY FROM JUST SOUTH OF ST LOUIS AND
FLORA TO TERRE HAUTE WILL SLOWLY LIFT BACK NORTH AS A WARM FRONT
TOWARD I-72 TONIGHT (STAYING SOUTH OF I-72 TONIGHT). AREA OF SHOWERS
AND THUNDERSTORMS WITH SOME HEAVY RAIN WAS ALONG AND SOUTH OF A
TAYLORVILLE TO MATTOON TO PARIS LINE AND LIFTING SLOWLY NORTHWARD.
THIS ASSOCIATED WITH MCV EAST OF ST LOUIS AND SLOWLY TRACKING NNE
INTO SW IL AT MID AFTERNOON. SHOWERS AND THUNDERSTORMS WILL SPREAD
NORTHWARD ACROSS CENTRAL IL LATE THIS AFTERNOON AND EVENING WHILE
BECOMING MORE SCATTERED IN SOUTHEAST IL AS THEY GET INTO THE WARM
SECTOR. TAIL END OF HRRR MODEL AND RAP13 MODEL SHOW MORE CONVECTION
SPREADING NE INTO SW CWA LATER TONIGHT AHEAD OF YET ANOTHER MCV OVER
EASTERN OK. SPC KEEPS MARGINAL RISK OF SEVERE STORMS SW OF IL OVER
MO THROUGH TONIGHT. A FEW STRONGER THUNDERSTORMS COULD HAVE WIND
GUSTS OVER 40 MPH WITH PEA SIZE HAIL AND HEAVY RAINS NEAR 1 INCH IN
LESS THAN AN HOUR. LOWS TONIGHT RANGE FROM UPPER 50S TO AROUND 60F
NORTH OF LINCOLN TO THE MID 60S FROM JACKSONVILLE AND SPRINGFIELD TO
MATTOON SOUTH.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 251 PM CDT SAT MAY 9 2015
UNSETTLED AND UNSEASONABLY MILD WEATHER PATTERN WILL PERSIST ACROSS
CENTRAL AND SOUTHEAST ILLINOIS THROUGH MONDAY. STILL A COUPLE MORE
WAVES IN THE PERSISTENT SOUTHWESTERLY FLOW ALOFT NEED TO MOVE
THROUGH THE AREA BEFORE THE VIGOROUS CUT-OFF UPPER LOW OVER THE FOUR
CORNERS REGION FINALLY DRIVES A COLD FRONT THROUGH THE AREA. THIS
FRONT WILL BE FOLLOWED BY COOLER & DRIER AIR FOR MUCH OF THE WORK
WEEK.
SUNDAY SHOULD START OUT WITH SHOWERS/STORMS ACROSS MUCH OF THE
REGION AS A DISTURBANCE, CURRENTLY PRODUCING VIGOROUS CONVECTION
ACROSS THE SOUTHERN PLAINS, TRACKS NORTHEAST ACROSS THE AREA. DO NOT
EXPECT THE MORNING STORMS TO BE SEVERE. THEN, ATTENTION TO THE UPPER
AND ASSOCIATED SURFACE LOW THAT WILL BE PICKING UP STEAM AS IT TRACK
NORTHEAST ACROSS THE PLAINS. A WARM FRONT EXTENDING SOUTHEAST FROM
THE LOW ACROSS THE MIDWEST WILL LIFT NORTH THROUGH THE DAY. STILL
SOME SIGNIFICANT MODEL DISAGREEMENT WITH RESPECT TO HOW QUICKLY THE
FRONT LIFTS NORTHWARD. THE POSITION OF THIS FRONT DURING PEAK
HEATING WILL BE KEY TO WHERE THE BEST SEVERE WEATHER THREAT WILL
EXIST. AT THIS POINT, IT APPEARS THE BEST SHEAR/INSTABILITY WILL CO-
EXIST ACROSS THE NORTHERN PORTION OF THE FORECAST AREA INTO NORTHERN
ILLINOIS. THE SHEAR PROFILES WILL BE SUBSTANTIALLY MORE IMPRESSIVE
FURTHER NORTHWEST, ACROSS IOWA, CLOSER TO THE TRACK OF THE
UPPER/SURFACE LOW. THE LOWS WILL TRACK ACROSS THE GREAT LAKES ON
MONDAY DRAGGING THE TRAILING COLD FRONT THROUGH ILLINOIS. STILL SOME
MODEL DISAGREEMENT IN THE SPEED OF THE COLD FRONT, WHICH WILL BE KEY
TO THE SEVERE WEATHER THREAT ON MONDAY. THE NAM, WHICH HAD BEEN THE
QUICKEST MODEL, IS NOW AMONG THE SLOWEST SOLUTIONS. CONTINUE TO
FAVOR A SLOWER SOLUTION GIVEN THE CURRENT POSITION/SPEED OF THE
SYSTEM OVER THE SOUTHWEST STATES, AND A TYPICAL MODEL BIAS OF BEING
TOO QUICK MOVING CUT-OFF LOWS. THESE FACTORS CONSIDERED, IT APPEARS
THAT THE BEST THREAT FOR SEVERE WEATHER ON MONDAY LOCALLY IS ACROSS
EAST CENTRAL AND SOUTHEAST ILLINOIS DURING THE MONDAY
AFTERNOON/EARLY EVENING HOURS.
QUIETER AND COOLER WEATHER IS EXPECTED TO ARRIVE MONDAY NIGHT AND
LINGER FOR MUCH OF THE REMAINDER OF THE WEEK. DAYTIME HIGHS THAT HAD
FREQUENTLY BEEN IN THE 80S AHEAD OF THE FRONT WILL MAINLY BE IN THE
60S AFTER FRONTAL PASSAGE. THE ECMWF, WHILE SLOWER THAN IT WAS A
COUPLE DAYS AGO, IS STILL THE QUICKEST TO BRING A SYSTEM BACK INTO
THE AREA BY THE END OF THE WEEK AS SOUTHWEST UPPER-LEVEL FLOW
REDEVELOPS AND TEMPERATURES TEND TO CLIMB BACK TOWARD NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1200 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL CONTINUE OVERNIGHT THROUGH ALL TAFS, SO
WILL KEEP VCSH AT ALL TAFS THROUGH MORNING HOURS. AREA OF
CONVECTION IN OK/ARK/SRN MO WILL MOVE ENE ACROSS SOUTHERN IL
OVERNIGHT AND SHOULD REMAIN SOUTH OF THE TAFS. COULD BE SOME
LINGERING SHOWERS REACH UP INTO THE AREA, BUT WILL NOT INCLUDE
ANYTHING FOR NOW. MORE PCPN IS POSSIBLE TONIGHT SO WILL HAVE VCTS
IN TAFS STARTING LATE AFTERNOON THROUGH EVENING HOURS. NOT SURE
WHEN A TEMPO GROUP FOR THUNDERSTORMS IS WARRANTED SO WILL LEAVE
OUT FOR NOW. IFR CONDITIONS HAVE MOVED INTO THE AREA AT ALL SITES
AND WILL LIKELY CONTINUE OVERNIGHT. THEN BY MORNING CIGS WILL
IMPROVE INTO THE MVFR CATEGORY. BY EVENING WHEN THE STORMS WILL BE
AROUND, VFR CONDITIONS WILL PREVAIL. WINDS WILL BE NORTHEAST AT
PIA/BMI WHICH ARE NORTH OF THE FRONT FOR NOW. SOUTH TO SOUTHEAST
WINDS WILL PREVAIL AT SPI/DEC/CMI. PIA AND BMI WILL SEE WINDS
BECOME SOUTHERLY DURING THE AFTERNOON/EVENING AS THE FRONT LIFTS
NORTH OF THE SITES.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AUTEN
SHORT TERM...07
LONG TERM...BAK
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1137 PM CDT SAT MAY 9 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 355 PM CDT SAT MAY 9 2015
QUIET FOR THE REST OF SATURDAY AND THEN STORM CHANCES ENTER THE FCST
LATE IN THIS SHORT TERM PERIOD. A POCKET OF DRIER AIR HAS BEEN IN
PLACE MOST OF SATURDAY AFTERNOON ACROSS THE CWA ALLOWING FOR
SUNSHINE TO PUNCH THROUGH ACROSS THE CENTRAL TO NORTHERN PARTS OF
OUR CWA.
THE LARGE AREA OF LOW PRESSURE WE HAVE BEEN TALKING ABOUT
FOR THE PAST FEW DAYS HAS REACHED THE FOUR CORNERS REGION OF THE
CONUS. THIS LOW IS SLATED TO BE LOCATED OVER WESTERN NEBRASKA BY 12Z
SUN. THE NAM IS A SLIGHT OUTLIER...KEEPING THIS SYSTEM SLOWER AND
FURTHER TO THE SOUTH THAN THE REST OF GUIDANCE. THE GFS IS THE
FASTEST. LEANED TOWARDS THE EURO...WHICH IS IN THE MIDDLE...FOR
TIMING. FOR LOW LEVEL MOISTURE INIT...USUAL MODEL BIASES IN PLACE.
THE NAM IS THE MOST MOIST...WHILE THE GFS IS OVERLY DRY. LEANED
TOWARDS EURO ONCE AGAIN.
AHEAD OF THIS AREA OF LOW PRESSURE...A WARM FRONT WILL BE PASSING
THROUGH OUR CWA FROM SW TO NE. ALL MODELS SHOW THE GULF IS WIDE OPEN
FOR MOISTURE TRANSPORT VIA THE LLJ...THE NOSE OF WHICH WILL BE ALONG
THE WESTERN/CENTRAL PART OF OUR CWA AT 12Z SUN. REGARDING THE SEVERE
WEATHER POTENTIAL...THE RAP SHOWS 0-1KM BULK SHEAR VALUES IN THE 20
TO 25KT RANGE...HELICITY IN THE 200 TO 400 RANGE AND LOW ENOUGH LCL
HEIGHTS TO SUGGEST TORNADOES MAY BE A SEVERE MODE THREAT EARLY ON.
DCAPE VALUES ARE ALSO HIGH EARLY ON...SO DAMAGING WINDS IS ALSO A
THREAT. LOCATION-WISE...THIS WILL MAINLY BE IN THE WESTERN/SW CWA AT
12Z. THE EVOLUTION OF SUNDAY/S SEVERE WEATHER WILL BE HANDLED IN THE
LONG TERM.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 355 PM CDT SAT MAY 9 2015
MAIN FORECAST CONCERN WAS FOCUSED ON SEVERE WEATHER POTENTIAL FOR
SUNDAY INTO SUNDAY NIGHT. THE REMAINDER OF THE FORECAST TIME FRAME
REMAINS RELATIVELY QUIET UNTIL LATE IN THE WORK WEEK.
SUNDAY INTO SUNDAY NIGHT...POTENTIAL EXISTS FOR AT LEAST TWO
ROUNDS OF SEVERE WEATHER ON MOTHERS DAY...WITH THE MORNING
CONVECTION SURGING NORTHWARD WITH THE WARM FRONT THROUGH 15Z AND
THEN THE DIURNALLY DRIVEN CONVECTION IN THE AFTERNOON ALONG THE
DRY LINE BY THE LATE AFTERNOON/EARLY EVENING. LEANED TOWARD THE
NAM12/ARWWRF FOR TIMING OF POPS SUNDAY INTO SUNDAY NIGHT EVEN
THOUGH MODELS ARE IN FAIRLY GOOD AGREEMENT WRT TO SURFACE LOW
TRACK AND TIMING OF COLD FROPA SUNDAY EVENING. THIS RESULTED IN
DELAYING THE AFTERNOON CONVECTION SLIGHTLY AS INITIATION LOOKS TO
BE AFTER 20Z SUNDAY OVER WESTERN PORTIONS OF THE FORECAST AREA.
THE WARM FRONT LOOKS TO SURGE NORTHWARD TO THE IOWA/MINNESOTA
BORDER BY AROUND 00Z MONDAY WITH THE SURFACE LOW CENTERED OVER
FAR NORTHWEST CORNER OF IOWA AND FAR SOUTHEAST SOUTH DAKOTA. THE
STRONGER AND DEEPER FORCING FOR ASCENT IS IN THIS LOCATION BUT
QUESTIONABLE WHETHER SURFACE INSTABILITY RECOVERS ENOUGH TO
SUPPORT LOW-LIVED TORNADIC SUPERCELLS. HOWEVER...ENOUGH ELEVATED
MUCAPE PRESENT COMBINED WITH STRONG LOW LEVEL SHEAR AND VORTICITY
WITHIN THE VICINITY OF THE WARM FRONT LOOKS TO COUNTERACT THE LACK
OF SURFACE INSTABILITY AND CERTAINLY PROVIDE A DECENT THREAT FOR
TORNADOES AND LARGE HAIL OVER WEST-CENTRAL TO NORTH-CENTRAL IOWA
TOMORROW AFTERNOON. DEEP LAYER SHEAR FROM 50 TO NEAR 70 KNOTS
PLENTY STRONG ENOUGH TO KEEP CONVECTION THROUGH THE EVENING SUNDAY
AS THE COLD FRONT PUSHES ACROSS IOWA. SEVERE POTENTIAL EXISTS
ALONG THE COLD FRONT WITH STRAIGHT-LINE WINDS THROUGH ROUGHLY 03Z
MONDAY BEFORE ENVIRONMENT BECOMES LESS FAVORABLE. THINKING ANY
SUPERCELLS THAT DEVELOP LATE TOMORROW AFTERNOON WILL MORPH INTO A
QLCS TYPE STRUCTURE WITH THE ADVANCEMENT OF THE COLD FRONT...WHICH
WOULD KEEP THE ROUNDS OF SEVERE WEATHER AT ONLY TWO. IF CONVECTION
PUSHES NORTH INTO MINNESOTA THEN A THIRD ROUND ALONG THE COLD
FRONT SEEMS FEASIBLE TOMORROW EVENING WITHIN THE DMX CWA.
MONDAY THROUGH WEDNESDAY...STRONG CAA DEVELOPS ON MONDAY INTO
MONDAY NIGHT AND MAY SEE A FEW SHOWERS ACROSS THE NORTH WITH
SOME WRAP-AROUND MOISTURE FROM THE SURFACE LOW. OTHERWISE...COOL
AND DRY CONDITIONS THROUGH WEDNESDAY.
THURSDAY INTO SATURDAY...LARGE UPPER LEVEL RIDGE BEGINS TO BREAK
DOWN WITH A FAIRLY STRONG VORT MAX EJECTING OUT OF THE SOUTHERN
ROCKIES THURSDAY. UNCERTAINTY IN TIMING WITH THE ECMWF ROUGHLY 12
HOURS QUICKER THAN THE GFS. BY THE END OF THE WORK WEEK AND INTO
NEXT WEEKEND...THE REGION IS PLACED BACK INTO SOUTHWEST FLOW ALOFT
AND EXTENDED MODELS HAVE MULTIPLE SHORTWAVES TO AFFECT THE FORECAST
AREA.
&&
.AVIATION...10/06Z
ISSUED AT 1136 PM CDT SAT MAY 9 2015
LATEST DATA SHOWS LITTLE CHANGE FROM PREVIOUS THINKING. STORMS
WILL FORM OVER NEBRASKA/WESTERN IA AND MOVE NORTH NORTHEAST
OVERNIGHT WITH POTENTIAL FOR SOME THUNDER AFT 09-10Z FOR KFOD AND
KDSM...LESSER CHANCES NOW FOR KALO|KOTM|KMCW OTHER THAN POSSIBLE
SHRA THROUGH 18Z AS INSTABILITY WILL WEAKEN FARTHER NORTH
OVERNIGHT AND EARLY SUNDAY. BREAK IN STORMS EXPECTED WEST/SOUTH
AFT 14-15Z SUN. CONDITIONS REMAIN LOW MVFR TO PERHAPS IFR NORTH
FOR MOST OF DAY...ELSEWHERE MVFR. RAP40 SHOWS POTENTIAL FOR SOME
TSRA REDEVELOPMENT AS EARLY AS 18Z SOUTHWEST/WEST WITH MAIN LINE
MOVING ACROSS AREA FROM 20|21Z THROUGH 06Z EAST AS DRY LINE IS
FORCED THROUGH THE AREA. BEST CHANCE FOR STRONG TO SVR STORMS WILL
BE WITH AFTERNOON PASSAGE OF DRY LINE. SOME LINGERING -SHRA AND SW
WINDS EXPECTED AFT 00Z. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KOTENBERG
LONG TERM...PODRAZIK
AVIATION...REV
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1154 PM CDT Sat May 9 2015
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Sunday)
Issued at 322 PM CDT SAT MAY 9 2015
An intense upper level trough was located across northwest NM. An 80
KT H5 jet max was lifting northeast across west TX into southwest
KS. A dryline was sharpening up from southeast CO, south-southeast
across the eastern TX PNHDL, then south into the hill country of
west central TX. The center of a lee cyclone, north of TAD. The warm
front extended east south-southeast from the lee cyclone, across
southwest KS, then east along the KS and OK border. A band of
elevated thunderstorms that formed across southeast CO and the TX
PNHDL earlier this morning continues to slowly move northeast across
central and south central KS. The area of elevated thunderstorms
were beginning to weaken as they move northeast into a more stable
airmass across eastern KS. An MCS was forming across central OK and
will move east-northeast across northeast OK into southwest MO.
The CWA will see a gradual increase in isolated to scattered shower
and thunderstorms late this afternoon, but with MUCAPES only 500 to
1000 J/KG these storms will not become severe this afternoon. As the
warm front begins to push north, the isentropic lift will begin to
weaken and we may see a break in the shower and thunderstorms
activity through the mid evening hours. Farther west, the atmosphere
is beginning to recover from the morning convection across the
eastern TX PNHDL, eastern CO and western KS. As the upper low over
northwest NM lifts northeast into east-central CO, numerous
thunderstorms should develop along the dryline as it begins to push
northeast across the eastern TX PNHDL into southwest KS and east
central CO. Intense upper level ascent ahead of the lifting upper
low will allow scattered supercell thunderstorms across western KS
to congeal into a QLCS or an MCS through the evening hours across
western KS. This storm complex will lift northeast across north
central KS late this evening and through the early morning hours of
Sunday. If a complex of thunderstorms develop the primary hazards
will be large hail, damaging winds and heavy rain. The meso-scale
models such as the RAP and WRF move the more intense portions of the
MCS north-northeast into southern NE just west of the CWA. Though,
there may be enough ascent that scattered thunderstorms will develop
south-southeast of this complex of thunderstorms. The primary hazard
of any severe thunderstorms across the CWA later Tonight will be
large hail, damaging wind gusts and heavy rainfall. The vertical
wind shear and MUCAPE do increase later Tonight, thus if a supercell
thunderstorm develops the boundary layer may not be decoupled enough
to prevent isolated tornadoes. However, at this time the better
chances for tornadic supercells will be this evening across western
KS.
Due to the uncertainty in the intensity and areal extent of wide
spread deep moist convection, I will not be issuing a flash flood
watch for the CWA. There is a chance for locally heavy rainfall with
any convective complex that develops. The isolated to scattered
thunderstorms later Tonight will move quickly to the northeast, so
expect only brief heavy rainfall. The better chances for heavy
rainfall will be associated with MCS`s that are forecasted to move
southeast and northwest of the CWA.
Sunday, there may be a few morning storms across the eastern
counties of the CWA. The upper low will begin to slowly fill as it
lifts northeast-northeast into western NE during the day. A strong
H5 jet max of 50 to 60 KTS will over spread eastern KS through the
afternoon hours. A cold front will quickly occlude the dryline
across central KS during the mid and late morning hours and the cold
front will push east across the western half of the CWA during the
early Afternoon hours. The numerical models all show the 850mb winds
slowly veering to the southwest ahead of the surface front. However,
the numerical models forecast southerly or even southeasterly
surface wind ahead of the surface front. The deepest gulf moisture
may get shunted eastward across MO into eastern IA but several
mesoscale models are showing 10 to 12 DEG Td at 850mb remaining
ahead of the surface front. There should be enough deep moisture and
instability for scattered thunderstorms to begin to develop along
the surface cold front by 20Z. The front should extend roughly from
a Seneca to Manhattan to Council Grove line by 3 PM. Thunderstorms
that develop will rapidly become severe given MLCAPES of 1500 to
2500 J/KG and SFC to 6KM effective shear of 50 to 60 KTS. Even
though 850mb winds begin to veer slightly the surface winds may
remain back. Therefore as storms first form they may be isolated to
scattered supercells before congealing into a squall line which will
then push east across northeast and east central KS during the late
afternoon hours. The 0-1 SRH of 150 to 250 J/KG may support any
discrete supercell to produce isolated tornadoes. Once the isolated
to scattered supercells merge into a squall line then the primary
hazards will be damaging winds gusts, large hail and heavy rainfall.
The line will move fairly fast across the eastern counties of the
CWA and begin to weaken after 6 PM due to the loss of surface
heating. Highs just behind the surface front across the central
counties of the CWA may reach to around 80 degrees, with most other
areas getting into the mid to upper 70s.
.LONG TERM...(Sunday Night through Saturday)
Issued at 322 PM CDT SAT MAY 9 2015
Sunday Night through Monday Night ...
By Sunday evening, models are in fairly good agreement with the
surface and mid-level patterns. A closed mid-level low should be
centered over the northern High Plains with the deep trough
stretching all the way southward toward the U.S./Mexico border. At
the surface, the center of low pressure should be focused across
northeast Nebraska with the associated cold front extending
southward and essentially bisecting the forecast area (i.e.,
stretching from Marysville to Manhattan to Herington by early
evening). This front placement is a bit further west than what
models were suggesting yesterday. Model soundings show little to no
inhibition in place across the area by late afternoon/early evening.
Expect decent advection of warm, moist air ahead of this boundary
from the breezy southerly winds, resulting in a decent set-up for
some strong to severe thunderstorms late afternoon into the evening
hours. Models suggest that isolated storms should develop along and
ahead of the cold front by late afternoon/early evening and quickly
congeal into a line of storms as the wind profiles look to prevail
out of the southwest. With a north/south oriented boundary, this
southwesterly flow should help to advance this line of storms fairly
quickly eastward across eastern KS with most of the forecast area
dry by midnight. Increasing low-level cloud cover combined with
little inhibition may result in slightly lower CAPE values upwards
of 1500-1800J/kg. Wind profiles show fairly unidirectional winds out
of the southwest with a 60-70kt 500mb jet, however there are some
discrepancies with regards to how much winds will veer in the lowest
2km of the atmosphere. As a result, there is a notable range amongst
the models in 0-1km helicity values across far eastern Kansas. LCL
values should be fairly low at around 3000ft or less, but the lapse
rates do not look that great. With these conditions and model
discrepancies in mind, confidence is low in the tornado threat
across eastern Kansas Sunday evening however an isolated tornado or
two still cannot be ruled out. Expect upwards of 50-60kts of 0-6km
shear, so combined with the modest instability the primary severe
threats look to be large hail and strong winds. Some locally heavy
rainfall will also be possible, which may potentially result in some
localized flash flooding and/or river flooding as some locations
have already received a few inches of rain this week. However, with
1-hr and 3-hr flash flood guidance near 2 inches, do not expect
widespread flooding concerns with these fast-moving storms.
Winds will slowly veer toward the west overnight into Monday morning
with clearing skies. As a result, decent radiational cooling should
help to drop low temperatures into the 40s. The mid-level trough
will lift northward out of the area through the day on Monday with
surface high pressure advancing into the High Plains behind this
exiting system. West-northwesterly surface winds will usher cooler
air into the region, keeping Monday high temperatures below normal
in the low/mid 60s. These cool conditions and mostly clear skies
will persist into Monday night with even cooler overnight low
temperatures in the upper 30s to mid 40s.
Tuesday through Saturday...
Tuesday will have mostly sunny skies and highs in the upper 60s,
with lows dropping into the upper 40s Tuesday night. The surface
high pressure aiding in these mild conditions will move southeast of
the area late evening, allowing winds to veer to the south by Wednesday
morning. This warm air advection will push highs into the lower
70s, before another system pushes into the area bringing chances for
precipitation every day for the rest of the period.
Models are still inconsistent with the handling this next system,
but agree with the previous forecast that the ECMWF solution seems
more reasonable. An upper-level wave will move NE into the central
plains by late Thursday bringing the best chances for thunderstorms
Wednesday night though Thursday night. Severe potential is still
low as the best CAPE/shear seems to be south or west of our area,
depending on the model. From here, thunderstorm chances remain until
Saturday, but confidence in timing and the overall pattern are
low.
&&
.AVIATION...(For the 06Z TAFs through 06Z Sunday Night)
Issued at 1153 PM CDT SAT MAY 9 2015
MVFR stratus lingering in the area and trends suggest more
persistent and lower cigs are likely through the next several
hours. Weak inversion should keep stratus in place through 15-17Z.
Caveat continues to be convection chances. At least some chance
remains even well ahead of dryline as moisture streams north but
again confidence too low for any early inclusion.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Heller/Hennecke
AVIATION...65
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1013 PM CDT MON MAY 11 2015
.DISCUSSION...
UPDATE THIS EVENING INCLUDED INCREASING WINDS ACROSS THE COASTAL
WATERS WEST OF INTRACOASTAL CITY...AS CURRENT OBSERVATIONS AND
LATEST HRRR GUIDANCE SHOW A SWATH OF 20-25 KT WINDS WITH GUSTS
30-35 KT POSSIBLE THRU EARLY MORNING. THE GROWING MCS ACROSS THE
TX COAST CONTINUES TO GENERATE A STRONG E TO SE INFLOW ACROSS OUR
COASTAL WATERS. THUS...SCEC UPGRADED TO SCA W OF INTRACOASTAL
CITY OUT 60 NM...INCLUDING SABINE AND CALCASIEU LAKE.
WITH THE PERSISTENCE E TO SE WINDS 20-25 KTS AND HIGH TIDE THIS
EVENING...CAMERON AND SABINE PASS TIDE GAUGES HAS RISEN A FOOT
OVER THE LAST COUPLE OF HOURS TO 2.2-2.3 FT MLLW AT 10 PM. WITH
HIGH TIDE ONGOING AND THE HIGHER WINDS EXPECTED TO PERSIST A FEW
MORE HOURS...TIDES MAY REACH 3.0 TO 3.5 FT MLLW DURING THIS TIME
PERIOD...WHICH MAY CAUSE SHORT TERM MINOR COASTAL FLOODING. FOR
THIS...ISSUED A COASTAL FLOOD ADVISORY THRU 4 AM FOR CAMERON
PARISH AND JEFFERSON COUNTY.
DML
&&
.PREV DISCUSSION... /ISSUED 850 PM CDT MON MAY 11 2015/
DISCUSSION...
FORECAST OVERHAUL THIS EVENING THANKS TO OUR PERSISTENT CLUSTER
OF THUNDERSTORMS OFF THE TX/LA COAST...FEEDING ON THE EASTERN
CONVERGENT SIDE OF A COASTAL SFC TROF OFF THE TX COAST.
THUS...SHIFTED HIGHEST POPS OFFSHORE THIS EVENING FOR CURRENT
TREND...DIMINISHED THEM INLAND. ALSO HAD TO ADJUST HOURLY
TEMP/DEWPTS TO NEAR 70 THIS EVENING...NOT EXPECTING MUCH CHANGE
OVERNIGHT...STAYING IN THE UPPER 60S/LOWER 70S THRU DAYBREAK.
GUIDANCE STILL INSISTING ON ADDITIONAL DEVELOPMENT INLAND ACROSS
INLAND SE TX/C LA AS THE FRONT CONTINUES TO SAG FURTHER SOUTH. AT
THIS RATE...LOOKS LIKE THE POPS MAY RAMP UP TOWARDS 09-12Z TIME
FRAME...AND MADE ADJUSTMENTS FOR THIS AS WELL.
DML
MARINE...
WITH THE PERSISTENCE CLUSTER OF TSRA ACROSS THE COASTAL WATERS
AND COASTAL TROF RAMPING UP ESE WINDS ~18-20KT THIS EVENING...HAVE
PLACED SCEC FOR ALL ZONES THRU 4 AM. BY THIS TIME...GRADIENT
EXPECTED TO RELAX AS FRONT SAGS FURTHER S TOWARDS THE COASTAL
WATERS BY DAYBREAK.
DML
PREV DISCUSSION... /ISSUED 653 PM CDT MON MAY 11 2015/
DISCUSSION...
FOR THE 00Z TAF PACKAGE.
AVIATION...
CONSIDERABLE CONVECTION OCCURRING OVER THE NW GULF WATERS ALONG
AND BEHIND AN EXTENSIVE OUTFLOW BOUNDARY THAT PUSHED THROUGH THE
AREA EARLIER TODAY. LGT TO MDT STRATIFORM TYPE RAIN CONTINUES TO
OCCASIONALLY STREAK ACROSS THE ACADIANA TERMINALS. ALL SITES
CURRENTLY VFR WITH MAINLY MID/HIGH LEVEL CLOUD COVER. CURRENT
MODEL DATA APPEARS TO BE GROSSLY UNDERDOING THE CONVECTION TO OUR
SOUTH...AND THUS HAVE LITTLE CONFIDENCE IN SOLUTIONS WHICH DEVELOP
ADDITIONAL ACTIVITY FARTHER NORTH EITHER LATE THIS EVENING OR
DURING THE OVERNIGHT HOURS. REGIONAL RADAR DOES APPEAR TO SHOW A
BIT OF A NWD PUSH TO CONVECTION NEAR THE MIDDLE TX COAST...SO
TRENDS WILL CONTINUE TO BE MONITORED. FOR NOW WILL CARRY
PREVAILING VFR...WITH SCATTERED LOW CLOUDS WORKING BACK IN DURING
THE OVERNIGHT/MORNING HRS.
13
PREV DISCUSSION... /ISSUED 413 PM CDT MON MAY 11 2015/
SYNOPSIS...
ACTIVE SUBTROP JET CONTINUES TO BRING MOISTURE OVER THE
REGION. A SERIES OF IMPULSES EMBEDDED IN THE SWLY FLOW ALOFT HAVE
AIDED IN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS...WITH
ADDITIONAL SUPPORT FM AN OUTFLOW BOUNDARY CROSSING THE CWA TODAY.
LATEST RADAR MOSAIC SHOWS A BAND OF CONVECTION CONTINUES TO
PROPAGATE SOUTH AND EAST ACRS THE LOWER MS VALLEY AND OVER OUR
COASTAL WATERS ZONES...WITH ADDITIONAL ACTIVITY FURTHER WEST ACRS
SE AND SRN TX. THERE WAS A SHORT PERIOD THIS MORNING PRIOR TO THE
ARRIVAL OF THE CONVECTION WHEN TEMPERATURES ACRS THE SRN ZONES
CLIMBED INTO THE LOWER 80S...BUT THESE QUICKLY FELL WITH THE
PASSAGE OF THE OUTFLOW BOUNDARY AND TEMPERATURES HAVE BEEN HELD IN
CHECK FOR MUCH OF THE DAY...RANGING FROM THE MIDDLE 60S ACRS
ACADIANA TO THE LOWER TO MIDDLE 70S ACRS SE TX AS OF 3 PM.
DISCUSSION...
A COLD FRONT...CURRENTLY EXTENDING FM NEAR KTXK TO KATT...WILL
MOVE INTO THE AREA OVERNIGHT WHILE ALOFT ANOTHER IMPULSE UPSTREAM
OVER NRN MEXICO WILL CROSS TX. EXPECT A BRIEF BREAK IN CONVECTION
DURING THE EVENING...WITH SHOWER AND TSTM CHCS INCREASING FM THE
WEST AGAIN OVERNIGHT. CONVECTION WILL INCREASE ACRS THE AREA
DURING THE DAY TUESDAY...WITH THE SFC FRONT SERVING AS A FOCUS.
SOME STORMS COULD BE STRONG OR MARGINALLY SVR...GIVEN THAT
SUFFICIENT DESTABILIZATION CAN OCCUR WITH DAYTIME HEATING...WITH
ISLTD STRONG DAMAGING WINDS OR MARGINALLY SVR HAIL THE MAIN
THREATS. ALSO...WITH ABUNDANT MOISTURE OVER THE REGION...ABV
NORMAL PRECIP WATER VALUES BETWEEN 1.5 AND 1.8 INCHES...STORMS
WILL ALSO BE CAPABLE OF PRODUCING HEAVY RAINFALL AND LOCALIZED
FLOODING COULD BE AN ISSUE. HIGH TEMPERATURES ON TUESDAY ARE
EXPECTED TO REACH THE LOWER 80S...BUT THIS WILL ALSO BE DEPENDENT
ON WHETHER THERE WILL BE ENOUGH BREAKS IN THE CLOUDS TO ALLOW
WARMING DURING THE DAY.
THROUGH THE REMAINDER OF THE WEEK...THE PATTERN ALOFT WILL CHANGE
LITTLE WITH SWLY FLOW PERSISTING BETWEEN A MEAN TROF OVER THE WRN
CONUS AND A RIDGE OVER THE ERN CONUS. A SERIES OF SHORTWAVE TROFS
WILL EJECT NE OVER THE CNTL PLAINS...AND INTERACT WITH THE MOIST
AND UNSTABLE AIRMASS OVER THE REGION LEADING TO AT LEAST A DAILY
CHC FOR SHOWERS OR TSTMS. AT THE SFC...HIGH PRES WILL MIGRATE
TOWARD THE EAST COAST...WITH SELY FLOW RESUMING BY WEDNESDAY.
WARM AND MUGGY CONDITIONS ARE EXPECTED TO PERSIST...WITH
TEMPERATURES RUNNING NEAR CLIMATOLOGICAL NORMS.
24
MARINE...
WINDS WILL BECOME ELY TONIGHT INTO TUESDAY AS A WEAK FRONT MOVES
INTO THE REGION AND BECOMES STALLED ALONG SE TX AND SW LA COAST.
ONSHORE FLOW WILL RESUME BY WEDNESDAY MORNING AS HIGH PRES
MIGRATES TOWARD THE EAST AND THE FRONT SLOWLY LIFTS BACK TO THE
NORTH OVER THE REGION. A LT TO MDT ONSHORE FLOW WILL THEN PERSIST
THROUGH NEXT WEEKEND.
24
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 66 80 66 83 / 50 50 30 30
LCH 70 83 70 82 / 40 60 30 30
LFT 70 84 70 84 / 50 50 30 30
BPT 70 82 71 82 / 40 60 30 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...COASTAL FLOOD ADVISORY UNTIL 4 AM CDT TUESDAY FOR LAZ073-074.
TX...COASTAL FLOOD ADVISORY UNTIL 4 AM CDT TUESDAY FOR TXZ215.
GM...SMALL CRAFT EXERCISE CAUTION UNTIL 4 AM CDT TUESDAY FOR GMZ435-
455-475.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT TUESDAY FOR GMZ430-432-450-
452-470-472.
&&
$$
PUBLIC...08
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
753 PM EDT MON MAY 11 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 328 PM EDT MON MAY 11 2015
A COLD FRONT WILL COME THROUGH THE AREA TONIGHT ENDING OVER A
WEEKS WORTH OF UNSEASONABLY WARM TEMPERATURES. THERE WILL BE
SHOWERS AND A FEW THUNDERSTORMS AHEAD OF THE COLD FRONT THIS
EVENING...THEN A FEW LIGHT RAIN SHOWERS TUESDAY AS CHILLY WESTERLY
WINDS KEEP AFTERNOON TEMPERATURES IN THE 50S. SKIES WILL BECOME
PARTLY CLOUDY TUESDAY NIGHT REMAIN SO ON WEDNESDAY. ANOTHER STORM
SYSTEM WILL BRING MORE SHOWERS AND POSSIBLY THUNDERSTORMS LATER
THIS WEEK INTO THE WEEKEND. IT WILL WARM UP AGAIN BY THE END TOO.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 328 PM EDT MON MAY 11 2015
THE MAIN ISSUE IS THE THREAT FOR SEVERE STORMS (NOT MUCH) THEN THE
CHANCE FOR LIGHT RAIN SHOWERS TUESDAY AND POSSIBLE FROST TOMORROW
NIGHT.
THE LATEST RAP MODEL SHOWS THE LOW LEVEL JET CORE LIFTING
NORTHEAST FROM SOUTHWEST LOWER MICHIGAN EARLY THIS AFTERNOON TO
THE THUMB AREA BY EARLY THIS EVENING. THE MOST UNSTABLE CAPE
(OVER 500 J/KG) STAYS JUST EAST OF OUR CWA LATE THIS AFTERNOON.
WHILE THERE IS GOOD DEEP LAYER SHEAR...THE RAIN COOLED AIR OVER
MOST OF OUR CWA WILL MITIGATE MOST OF THE SEVERE WEATHER THREAT.
POSSIBLY ISOLATED DAMAGING WINDS COULD HAPPEN OVER OUR EXTREME
SOUTHEAST COUNTIES EARLY THIS EVENING.
OTHERWISE THE AREA OF RAIN WILL MOVE OUT BY MID EVENING. THEN THE
DRY SLOT MOVES IN BEHIND THE COLD FRONT SO SKIES WILL CLEAR AT
LEAST PARTLY. WE THEN GET WRAP AROUND COLD AIR ADVECTION
INSTABILITY SHOWERS (MOSTLY SPRINKLES) TUESDAY AND IT WILL BE
BREEZY AND CHILLY WITH HIGHS ONLY IN THE 50S.
THE UPPER TROUGH MOVES OUT QUICKLY TUESDAY NIGHT ALLOWING FOR SOME
CLEARING. FROST IS POSSIBLE OVER NORTHERN AREAS WEDNESDAY MORNING.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 328 PM EDT MON MAY 11 2015
AS HIGH PRESSURE MOVES EAST THURSDAY LOW PRESSURE WILL MOVE TOWARD
THE GREAT LAKES. CONFIDENCE IS INCREASING THAT WE/LL SEE SOME
PRECIPITATION MOVE OVER THE CWA THURSDAY NIGHT AND FRIDAY. ADDED
THUNDER TO THE GRIDS FRIDAY AS LI/S FALL TO AROUND -2C AND CAPE
INCREASES TO 1K J/KG. MUCH OF THE PCPN WILL BE EAST OF THE CWA BY
SATURDAY AS THE SFC LOW MOVES AWAY. HOWEVER WE/LL KEEP LOW POPS IN
TO COVER THE UPPER TROUGH.
CHANCES FOR TSRA WILL INCREASE TOWARD THE BEGINNING OF NEXT WEEK AS
A STRONGER COLD FRONT MOVES TOWARD THE CWA. STRONG SOUTH FLOW AHEAD
OF IT WILL SEND ABUNDANT MOISTURE NORTHWARD AND CREATE SOME
INSTABILITY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 752 PM EDT MON MAY 11 2015
PREDOMINATELY MVFR CIGS AND SCTD RAIN SHOWERS EARLY THIS EVENING
WILL GIVE WAY TO MOSTLY VFR CIGS AFTER 02Z AS DRIER AIR SWEEPS IN
BEHIND A COLD FRONT. THERE IS CURRENTLY SOME FOG OVER LAKE
MICHIGAN AND THIS WILL RESULT IN OCNL IFR CONDITIONS AT MKG FOR A
COUPLE MORE HOURS THIS EVENING. THE THREAT OF TSTMS HAS ENDED.
AROUND 12Z TUESDAY MORE MVFR CIGS WILL SPREAD IN FROM THE WEST AND
PERSIST MUCH OF THE DAY. A FEW LIGHT SHOWERS ARE POSSIBLE BUT IF
ANY REDUCTIONS TO VSBYS OCCURRED IT SHOULD BE VERY BRIEF.
GUSTY SOUTHWEST TO WEST SFC WINDS OF 15 TO 25 KNOTS TONIGHT WILL
INCREASE TO 20 TO 30 KNOTS ON TUESDAY... RESULTING IN SOME LOW
LEVEL TURBULENCE.
&&
.MARINE...
ISSUED AT 328 PM EDT MON MAY 11 2015
THE STRONG WINDS BEHIND OUR SYSTEM WILL LEAD TO 4 TO 6 FOOT WAVES
AND WINDS TO 30 KNOTS BY MID MORNING TUESDAY. AS A RESULT I ISSUED
A SMALL CRAFT ADVISORY.
&&
.HYDROLOGY...
ISSUED AT 1222 PM EDT MON MAY 11 2015
ADDITIONAL RAINFALL AMOUNTS BETWEEN A QUARTER AND THREE QUARTERS OF
AN INCH WILL BE POSSIBLE MAINLY BEFORE MIDNIGHT TONIGHT. WE ARE
ISSUING ADVISORIES FOR THE SYCAMORE CREEK AT HOLT...WHICH SHOULD
CREST SHORTLY AFTER MIDNIGHT TONIGHT. CONFIDENCE IS HIGH THAT IT
WILL REMAIN BELOW FLOOD STAGE.
AFTER TONIGHT DRY CONDITIONS SHOULD PREVAIL UNTIL THURSDAY...WHEN
RAIN SHOWERS RETURN TO THE AREA. THIS SHOULD GIVE RIVER LEVELS
SOME TIME TO SUBSIDE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 5 AM TO 6 PM EDT TUESDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...93
AVIATION...MEADE
HYDROLOGY...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
751 PM EDT MON MAY 11 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 421 PM EDT MON MAY 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE MID LEVEL LOW THAT WAS
OVER WRN NEBRASKA/SD 24HRS AGO NOW CENTERED IN WCNTRL MN. AHEAD OF
FEATURE...WARM CONVEYOR BELT MOISTURE RIBBON EXTENDS FROM THE LWR
MISSISSIPPI VALLEY TO THE WRN GREAT LAKES. RESULT HAS BEEN NMRS SHRA
SPREADING ACROSS THE FCST AREA TODAY. A FEW TSTMS WERE NOTED THIS
MORNING OVER THE W HALF OF UPPER MI. AT THE SFC...LOW PRES LOCATED
IN CNTRL MN IS BECOMING LESS WELL-DEFINED WITH TENDENCY FOR LOW PRES
REDEVELOPMENT AT THE TRIPLE POINT FARTHER E. OCCLUDED FRONT IS
APPROACHING THE MI/WI BORDER AS OF 20Z.
AS THE WARM CONVEYOR MOISTURE RIBBON TRANSLATES E...WIDESPREAD SHRA
NOW OVER THE E HALF OF THE FCST AREA WILL ALSO SHIFT E AND OUT OF
THE AREA IN THE NEXT FEW HRS. FOG AND SOME -DZ WILL PERSIST IN THE
UPSLOPE FLOW OFF LAKE SUPERIOR INTO THE KEWEENAW AND WRN PORTIONS OF
NCNTRL UPPER MI...AND A FEW SHRA MAY DEVELOP NEAR THE OCCLUDED FRONT
WHICH SHOULD LIFT INTO OR THRU MUCH OF CNTRL AND ERN UPPER MI THIS
EVENING. OTHERWISE...AS MID LEVEL LOW OPENS UP AND UPPER TROF MOVES
E INTO THE WRN GREAT LAKES TONIGHT...DEEPER MOISTURE WILL WRAP BACK
INTO THE AREA FROM THE N AND W. AIDED BY DEEP CYCLONIC FLOW...SHRA
WILL SPREAD BACK INTO THE FCST AREA...ESPECIALLY ACROSS THE W. AS
CAA INCREASES OVERNIGHT...FCST SOUNDINGS/WETBULB ZERO HEIGHTS
SUGGEST POTENTIAL FOR SNOW TO MIX WITH THE RAIN OVER THE HIGH
TERRAIN OF THE W LATE TONIGHT.
AS TROF CONTINUES TO SHIFT E TUE...DEEP LAYER QVECTOR DIVERGENCE
OVERSPREADS THE AREA WITH HEIGHTS BEGINNING TO RISE...MORE
SUBSTANTIALLY IN THE AFTN. THIS WILL TEND TO DIMINISH THE WRAP
AROUND PCPN WITH TIME...BUT THIS WILL BE COUNTERACTED BY SHARP
CYCLONIC FLOW AND CONSIDERABLE LOW TO MID LEVEL MOISTURE THAT
LINGERS THRU THE DAY. THIS WILL RESULT IN PCPN BEING MOST PERSISTENT
IN THE AREAS THAT SEE UPSLOPING UNDER NW TO N WINDS. DOWNSLOPE AREAS
WILL SEE PCPN DIMINISH OR END. CONTINUED CAA WILL DROP 850MB TEMPS
TO -3 TO AS LOW AS -6C...AND THIS WILL RESULT IN RAIN MIXING WITH
SNOW...MAINLY OVER THE HIGHER TERRAIN OF THE W AND CNTRL. PCPN WILL
LIKELY CHANGE TO ALL SNOW AT LEAST FOR A TIME OVER THE HIGH TERRAIN
OF THE W HALF AS LOWEST 850MB TEMPS ARE FCST THERE. THAT AREA WILL
ALSO HAVE THE BEST CHANCE FOR A LITTLE SNOW ACCUMULATION ON GRASSY
SFCS. IT WILL BE AN UNSEASONABLY COLD DAY WITH TEMPS AROUND 20
DEGREES BLO NORMAL ACROSS THE W AND N WHERE TEMPS WILL STRUGGLE TO
GET MUCH ABOVE 40F. ACROSS THE SCNTRL...TEMPS MAY SNEAK INTO THE LWR
50S. BLUSTERY WINDS WILL ADD TO THE CHILL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 255 PM EDT MON MAY 11 2015
WILL STILL HAVE SOME LINGERING MAINLY SNOW SHOWERS /WITH A FEW RAIN
SHOWERS OR AREAS OF DRIZZLE MIXED IN/ TUESDAY NIGHT OVER THE N HALF
OF UPPER MI. THE BEST CHANCE OF PRECIP WILL BE N CENTRAL AS
FAVORABLE N-NNW WINDS RESIDE THERE FROM THE SFC-850MB. TEMPERATURES
WILL BE COOLING INTO THE LOW 30S OVERNIGHT...WITH LOCATIONS OVER THE
INTERIOR W HALF FALLING INTO THE MID 20S AS WINDS BECOME NEARLY CALM
AND DRIER AIR WORKS IN AND 850MB TEMPS BEGIN TO WARM SLIGHTLY FROM -
4 TO -6C...TO AROUND -3C.
HIGH PRESSURE WILL BE STRETCHING FROM HUDSON BAY THROUGH MANITOBA
AND MN...DOWN THROUGH THE MS VALLEY AT 00Z WEDNESDAY. LOOK FOR THE
AREA OF HIGH PRESSURE TO BUILD ACROSS THE UPPER GREAT LAKES THROUGH
WEDNESDAY...WITH DRY WEATHER FIGURED INTO AT LEAST WEDNESDAY
EVENING. WAA WILL TAKE HOLD AT THE SFC ON MAINLY S WINDS OVER THE W
HALF OF THE CWA...WITH AFTERNOON HIGHS IN THE 50S FOR MOST LOCATIONS
/EXCLUDING THE COOLER N CENTRAL AND E
LAKE SUPERIOR SHORELINE/ AS 850MB TEMPS REBOUND TO AROUND 4C W TO 1C
E.
PRECIP COULD SLIDE IN AS EARLY AS LATE WEDNESDAY AFTERNOON SW /GFS
SOLUTION/. THIS WOULD BE ALONG THE SW AS AN INITIAL FRONTAL BOUNDARY
SHIFTS TO OUR N. THE MAIN CONCERN IS THAT THE LOWER LEVELS WILL BE
TOO DRY WITH THE SFC RIDGE STILL OVER MUCH OF THE AREA WITH THIS
BOUNDARY/SHORTWAVE ROUNDING THE 500MB RIDGE. WILL CONTINUE TO GO
WITH A MINIMAL PRECIP SOLUTION FOR THIS PERIOD. THE SFC HIGH WILL
SHIFT ACROSS THE ENTIRE GREAT LAKES REGION WEDNESDAY NIGHT...WITH
SLOWLY INCREASING S FLOW OVER UPPER MI PUSHING IN INCREASED MOISTURE
AS 850MB TEMPS RUMP TO AROUND 8C OVER THE SW.
THE APEX OF THE 500MB RIDGE WILL BE ACROSS THE AREA THURSDAY
AFTERNOON...WITH FCST MODELS INDICATING A NEARING EMBEDDED 500MB
TROUGH IN THE SW FLOW OVER THE N PLAINS AND W MN. THE GFS HAS A
DEEPER/WRAPPED UP SFC LOW OVER THE CENTRAL PLAINS OFF THE GFS IS NOT
QUITE A S STRONG AS THE ECMWF...ESPECIALLY THE PREVIOUS 11/06Z RUN.
THIS LEADS TO ONLY MODERATE CONFIDENCE IN THE FCST BEYOND THURSDAY.
THE DIFFERENCE SHOWS UP WELL IN THE MODEL QPF...WITH THE 11/06Z GFS
SHOWING 24HR PRECIP OF 0.75-1.45IN BY 00Z SATURDAY. THE 11/00Z ECMWF
ON THE OTHER HAND RANGES FROM LESS THAN 0.10IN ACROSS THE KEWEENAW
PENINSULA...TO 0.5IN OVER FAR S MENOMINEE CO. THIS WILL BE AS THE
SFC LOW OFF THE GFS TRACKS FROM THE CENTRAL PLAINS TO N LAKE MI BY
00Z SATURDAY. THE CANADIAN THE ECMWF KEEP A RIDGE ACROSS LAKE
SUPERIOR AND MUCH OF UPPER MI DURING THE SAME TIME PERIOD. ON A
POSITIVE NOTE...THE 11/12Z GFS CAME IN AT LEAST A LITTLE LESS
INTENSE WITH THE SFC LOW...AND DROPS ABOUT 1/2 AS MUCH PRECIP.
AN ADDITIONAL LOW DEVELOPING OFF THE N ROCKIES TOWARDS THE END OF
THE WORK WEEK WILL LIKELY BE SET UP ACROSS MT AND WY SATURDAY
MORNING...AND MOVE ACROSS THE DAKOTAS SATURDAY NIGHT...AND THE UPPER
GREAT LAKES ON MONDAY. THE 12Z RUNS HAVE BECOME MUCH MORE IN LINE
WITH THE SFC LOW TRACKING OVER E MN/FAR W LAKE SUPERIOR BY 06Z
MONDAY. THE RESULT IS AT LEAST MODERATE CONFIDENCE IN RAIN. WILL GO
WITH LIKELY PRECIP FOR SUNDAY NIGHT ACROSS MOST OF THE CWA. SO FOR
THE UPCOMING WEEKEND IT LOOKS TO BE MAINLY DRY SATURDAY...WITH WET
WEATHER APPROACHING SUNDAY AND POSSIBLY LINGERING INTO MONDAY AS THE
SFC LOW SLOWLY EDGES E OF THE CWA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 740 PM EDT MON MAY 11 2015
A LOW PRES SYSTEM WILL MOVE E ACROSS THE UPPER GREAT LAKES TONIGHT
AND THEN E TO QUEBEC TUE. ABUNDANT LOW-LEVEL MOISTURE WILL GENERALLY
SUPPORT IFR TO LIFR CONDITIONS AND -SHRA AT KIWD/KCMX/KSAW THRU THIS
FCST PERIOD WITH THE LOWEST CONDITIONS OCCURRING AT TERMINALS
EXPERIENCING UPSLOPE WINDS. THE LOWEST CONDITIONS (VLIFR) THIS
EVENING WILL OCCUR AT KCMX UNDER UPSLOPE WESTERLY WINDS. SLIGHTLY
DRIER AIR WORKING N THRU WI MAY REACH KIWD AND KSAW FOR A TIME THIS
EVENING ALLOWING FOR A PERIOD OF MVFR CONDITIONS. THIS IS MORE
LIKELY TO HAPPEN AT KSAW. COLDER AIR WRAPPING INTO THE AREA BEHIND
THE LOW SHOULD BE COLD ENOUGH TO RESULT IN -SHRA MIXING WITH OR
CHANGING OVER TO -SHSN TUE MORNING. CHANGE OVER TO ALL SNOW IS MORE
LIKELY TO OCCUR AT KIWD/KCMX. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 PM EDT MON MAY 11 2015
ONGOING MARGINAL GALES OVER THE WRN PORTION OF LAKE SUPERIOR WILL
CONTINUE TO DIMINISH...FALLING BLO GALE FORCE EARLY THIS EVENING...
AS PRES GRADIENT WEAKENS AND WINDS BACK DUE TO LOW PRES SHIFTING
ACROSS UPPER MI AND ERN LAKE SUPERIOR. ON THE BACK SIDE OF THE
LOW...NNW WINDS WILL INCREASE TO 20-30KT ACROSS CNTRL AND ERN LAKE
SUPERIOR LATE TONIGHT/TUE MORNING. MAY SEE A FEW GALE FORCE GUSTS
TUE MORNING OVER SCNTRL LAKE SUPERIOR AROUND GRANITE ISLAND DUE TO
LOCAL COASTAL CONVERGENCE. WINDS WILL DIMINISH FROM W TO E TUE
AFTN/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU. AS THE HIGH PRES SHIFTS E AND A WEAK LOW PRES
PASSES BY TO THE S...WINDS MAY INCREASE SOME FOR THU NIGHT/FRI
BEFORE DIMINISHING AGAIN ON SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EDT SUN MAY 10 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 417 PM EDT SUN MAY 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE WELL-DEFINED MID LEVEL
LOW THAT WAS OVER THE SRN ROCKIES YESTERDAY NOW LIFTING N ACROSS WRN
NEBRASKA/WRN SD. ONE WEAK LEAD SHORTWAVE THAT WAS OVER THE SRN
PLAINS YESTERDAY HAS MOVED NE THRU LWR MI TODAY...SPREADING SHRA AND
A FEW TSRA ACROSS LWR MI. CLOSER TO HOME...WEBCAMS INDICATED SOME
PATCHY -DZ THIS MORNING OVER ERN PARTS OF THE FCST AREA AS LOW
CLOUDS SPREAD BACK INTO MUCH OF UPPER MI. OTHERWISE...NO PCPN HAS
OCCURRED TODAY. CLOUDS HAVE DOMINATED MOST OF THE FCST AREA.
HOWEVER...MUCH OF THE WRN FCST AREA HAS BECOME MOSTLY SUNNY RECENTLY
AS THE LOW CLOUDS HAVE DISSIPATED IN THAT AREA.
TONIGHT AND MON...MID LEVEL LOW MOVING INTO SD WILL GRADUALLY OPEN
UP AS IT DRIFTS INTO MN. ON THIS TRACK...THE STRONGEST DEEP LAYER
FORCING (SHOWN NICELY BY QVECTORS) AND STRONGEST ISENTROPIC ASCENT
WILL FOCUS INTO NRN MN. FARTHER E...A WEAKER EASTWARD EXTENSION OF
DEEP LAYER FORCING COMBINED WITH A RIBBON OF REASONABLY STRONG
ISENTROPIC ASCENT LIFTING NE ACROSS THE AREA SHOULD SUPPORT A PERIOD
OF SHRA...MAINLY LATE TONIGHT THRU MON MORNING. THERE IS VERY LITTLE
TO NO INSTABILITY NOTED ACCOMPANYING THIS BAND OF FORCING/SHRA...SO
THUNDER POTENTIAL IS VERY LIMITED. WILL MAINTAIN A SCHC MENTION ONLY
OVER THE FAR SCNTRL...CLOSER TO SOMEWHAT BETTER ELEVATED INSTABILITY
TO THE S. MID LEVEL DRYING PUSHES INTO THE FCST AREA DURING THE DAY
MON...FOLLOWING THE RIBBON OF ISENTROPIC ASCENT. THIS SHOULD RESULT
IN A TRANSITION TO MAINLY DRY WEATHER OVER MOST OF THE AREA. BETTER
CHC OF LINGERING ISOLD/SCT -SHRA IN THE AFTN WILL BE OVER THE N AND
E. THAT SAID...SEEMS MORE LIKELY THAT WHERE UPSLOPE FLOW PERSISTS...
LINGERING LOW-LEVEL MOISTURE MAY RESULT IN SOME -DZ AND UPSLOPE
FOG...MAINLY ACROSS THE KEWEENAW AND NCNTRL UPPER MI. COMBINATION OF
RAIN AND HIGHER DWPTS SPREADING N OVER LAKE MI WILL LIKELY MEAN FOG
SPREADING UP LAKE MI AND AFFECTING AREAS MAINLY E OF KESC AS WELL.
LATER IN THE AFTN...BROADENING SFC LOW/OCCLUDED FRONT MAY SLIP INTO
THE SRN FCST AREA. GFS/NAM SHOW SOME LOW-LEVEL INSTABILITY (FEW
HUNDRED J/KG) NEAR THIS FEATURE. COULD SPARK ISOLD TSRA LATE...BUT
CONFIDENCE IN THAT OCCURRING IS VERY LOW. AS FOR TEMPS...THERE IS
BIG BUST POTENTIAL WITH MAX TEMPS ON MON. IF THE OCCLUDED FRONT
LIFTS INTO SRN UPPER MI AND CLOUDS BREAK...TEMPS COULD QUICKLY RISE
WELL INTO THE 60S. SOME OF THE BIAS CORRECTED GUIDANCE HAS MAX TEMPS
UP AROUND 70F NEAR THE MI/WI BORDER. FOR NOW...HAVE MAX TEMPS NEAR
60F OVER THE SCNTRL. TO THE N...WHERE FLOW REMAINS UPSLOPE OFF LAKE
SUPERIOR...TEMPS SHOULD NOT RISE HIGHER THAN THE LWR 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 PM EDT SUN MAY 10 2015
MUCH OF THIS PERIOD WILL BE COOL...WITH TEMPERATURES ONLY RETURNING
TO NEAR NORMAL FOR DAYTIME HIGHS FOR FRIDAY
FOR MONDAY NIGHT WE WILL START OFF WITH THE 500MB LOW SET UP ACROSS
MN. THE 500MB LOW WILL BECOME AN OPEN WAVE OVERNIGHT AS IT MOVES
OVER LAKE SUPERIOR AND EXITS TO THE NE TUESDAY. AT THE SFC...THE LOW
WILL BE ACROSS THE S HALF OF THE CWA AT 00Z TUESDAY...SHIFTING TO
THE E HALF BY 06Z...AND EXITING NE WITH A TROUGH LINGERING ACROSS
UPPER MI THROUGH MUCH OF THE DAY TUESDAY.
COULD WE HAVE SIGNIFICANT SNOW TUESDAY WITH THE HELP OF FAVORABLE
UPSLOPE WINDS OFF LAKE SUPERIOR BEHIND THE EXITING SFC LOW? WHILE
FCST MODELS ARE INDICATING 0-3IN OF SNOW MAINLY DURING THE DAY
TUESDAY...THERE ARE A FEW NEGATIVES TO ANY SIGNIFICANT SNOW THAT
COULD POSE A THREAT TO COMMERCE. THE NAM AND GFS DO SHOW A NOSE OF
WARMER AIR BETWEEN 750MB AND 800MB RISING ABOVE THE FREEZING LEVEL.
AT THIS POINT IT LOOKS TO BE A SMALL ENOUGH TO ONLY HAVE A SMALL
IMPACT ON SNOW. IT WILL BE NOTHING LIKE THE 20:1 SLR VALUES OF MID
WINTER. RATIOS WILL LIKELY BE ON THE ORDER OF 8:1 AND LOWER. THE MID
MAY SUN IS GIVING NEARLY 15HRS BETWEEN SUNRISE AND SUNSET. CURRENTLY
GOING WITH AN INCH OR LESS...MAINLY OVER THE FAR W HIGHER TERRAIN.
LOOK FOR RIDGING ALOFT ALREADY BY THE END OF THE DAY TUESDAY. THE
INITIAL TROUGH WILL HAVE MOVED TO E ONTARIO/S QUEBEC...WITH A
SECONDARY TROUGH EXTENDING W ACROSS S MANITOBA AND SAKATCHEWAN. AT
THE SFC...WINDS WILL ALREADY BE TURNING MORE OUT OF THE W TUESDAY
NIGHT /MAINLY OVER THE W/...IN RESPONSE TO THE LARGE NEARING AREA OF
HIGH PRESSURE EXTEDING FROM N CANADA THROUGH THE GULF STATES TUESDAY
AFTERNOON THAT WILL PUSH ACROSS THE W HALF OF THE CWA OVERNIGHT.
THE 500MB RIDGE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES
THROUGH THURSDAY AS THE CENTRAL CANADIAN TROUGH LINGERS. DRY AND
COOL AIR WILL BE OVERHEAD AS THE SFC HIGH OVER THE GREAT LAKES
THURSDAY MORNING SHIFTS E TOWARDS THE ATLANTIC.
ALTHOUGH WITH DIFFERING TIMING...THERE ARE INDICATIONS THAT A LOW IN
THE SW FLOW WILL BE ABLE TO EJECT UP ACROSS THE N PLAINS ON
THURSDAY. THE 10/12Z ECMWF SOLUTION FOLLOWS SIMILARLY TO THE
CANADIAN...WHILE THE GFS KEEPS THE SYSTEM A WHOLE LOT WEAKER AND
FARTHER TO THE S. CURRENTLY RUNNING WITH SLIGHT CHANCE TO LOW CHANCE
POPS. GIVEN THE UNCERTAINTY WITH THIS 100 PLUS HR FCST...THIS SEEMS
REASONABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 137 PM EDT SUN MAY 10 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. INITIALLY...WILL
NEED TO DEAL WITH AREAS OF LOW CLOUDS/MVFR CIGS ACROSS THE AREA. AS
LOW-LEVEL WINDS VEER TO A MORE DOWNSLOPING EASTERLY DIRECTION AT
KIWD...EXPECT MVFR CIGS TO LIFT TO VFR THIS AFTN. MEANWHILE...WITH
BACK EDGE OF MVFR CIGS RAPIDLY APPROACHING KCMX FROM THE E...VFR
CONDITIONS WILL LIKELY DEVELOP THERE THIS AFTN. AT KSAW...LARGE AREA
OF MVFR CIGS TO THE E AND NE SUGGESTS MVFR CIGS MAY HOLD THRU THE
AFTN...BUT NOT OUT OF THE QUESTION THAT IMPROVEMENT TO VFR COULD
OCCUR LATE AFTN. TONIGHT...LOW PRES SYSTEM MOVING NE THRU THE PLAINS
WILL SWING SHRA NE INTO THE UPPER LAKES...MAINLY LATE TONIGHT/MON
MORNING. WHILE KSAW MAY REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF
PCPN...VFR CONDITIONS MAY LINGER THIS EVENING AT KIWD AND POTENTIALLY
THRU THE NIGHT AT KCMX. WITH THE ARRIVAL OF THE -SHRA...EXPECT A
TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS. UPSLOPE
FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT KCMX/KSAW BY
LATE MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT SUN MAY 10 2015
TIGHT PRES GRADIENT WILL BE OVER LAKE SUPERIOR TONIGHT THRU MUCH OF
MON AS HIGH PRES REMAINS NEARLY STATIONARY...CENTERED OVER FAR NRN
ONTARIO...AND LOW PRES MOVES FROM NEBRASKA TO FAR NRN WI. AS A
RESULT BRISK NE TO E WINDS OF 15-30KT WILL BE THE RULE ACROSS LAKE
SUPERIOR. THE STRONGEST WINDS (GALE FORCE) WILL BE OVER THE WRN
PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW THRU AT LEAST EARLY MON MORNING WILL
ENHANCE THE WINDS. THE GALES OVER THE WRN PORTION OF LAKE SUPERIOR
WILL DIMINISH MON EVENING AS THE PRES GRADIENT WEAKENS AND LOW PRES
SHIFTS E OF THE AREA...RESULTING IN BACKING WINDS. WINDS WILL
DECREASE ACROSS THE LAKE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS
MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE
UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS
E...WINDS MAY INCREASE A LITTLE FOR THU NIGHT/FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
249 PM EDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN MAY 10 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW
FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE
SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS
DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION.
WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW
CLOUDS BACK INTO NRN UPPER MI.
TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO
BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR.
HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT
CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP.
OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE
EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE
CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD
OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN
HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE
READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S.
TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE
POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY
12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE
STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN
INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED
OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT
SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 PM EDT SUN MAY 10 2015
MUCH OF THIS PERIOD WILL BE COOL...WITH TEMPERATURES ONLY RETURNING
TO NEAR NORMAL FOR DAYTIME HIGHS FOR FRIDAY
FOR MONDAY NIGHT WE WILL START OFF WITH THE 500MB LOW SET UP ACROSS
MN. THE 500MB LOW WILL BECOME AN OPEN WAVE OVERNIGHT AS IT MOVES
OVER LAKE SUPERIOR AND EXITS TO THE NE TUESDAY. AT THE SFC...THE LOW
WILL BE ACROSS THE S HALF OF THE CWA AT 00Z TUESDAY...SHIFTING TO
THE E HALF BY 06Z...AND EXITING NE WITH A TROUGH LINGERING ACROSS
UPPER MI THROUGH MUCH OF THE DAY TUESDAY.
COULD WE HAVE SIGNIFICANT SNOW TUESDAY WITH THE HELP OF FAVORABLE
UPSLOPE WINDS OFF LAKE SUPERIOR BEHIND THE EXITING SFC LOW? WHILE
FCST MODELS ARE INDICATING 0-3IN OF SNOW MAINLY DURING THE DAY
TUESDAY...THERE ARE A FEW NEGATIVES TO ANY SIGNIFICANT SNOW THAT
COULD POSE A THREAT TO COMMERCE. THE NAM AND GFS DO SHOW A NOSE OF
WARMER AIR BETWEEN 750MB AND 800MB RISING ABOVE THE FREEZING LEVEL.
AT THIS POINT IT LOOKS TO BE A SMALL ENOUGH TO ONLY HAVE A SMALL
IMPACT ON SNOW. IT WILL BE NOTHING LIKE THE 20:1 SLR VALUES OF MID
WINTER. RATIOS WILL LIKELY BE ON THE ORDER OF 8:1 AND LOWER. THE MID
MAY SUN IS GIVING NEARLY 15HRS BETWEEN SUNRISE AND SUNSET. CURRENTLY
GOING WITH AN INCH OR LESS...MAINLY OVER THE FAR W HIGHER TERRAIN.
LOOK FOR RIDGING ALOFT ALREADY BY THE END OF THE DAY TUESDAY. THE
INITIAL TROUGH WILL HAVE MOVED TO E ONTARIO/S QUEBEC...WITH A
SECONDARY TROUGH EXTENDING W ACROSS S MANITOBA AND SAKATCHEWAN. AT
THE SFC...WINDS WILL ALREADY BE TURNING MORE OUT OF THE W TUESDAY
NIGHT /MAINLY OVER THE W/...IN RESPONSE TO THE LARGE NEARING AREA OF
HIGH PRESSURE EXTEDING FROM N CANADA THROUGH THE GULF STATES TUESDAY
AFTERNOON THAT WILL PUSH ACROSS THE W HALF OF THE CWA OVERNIGHT.
THE 500MB RIDGE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES
THROUGH THURSDAY AS THE CENTRAL CANADIAN TROUGH LINGERS. DRY AND
COOL AIR WILL BE OVERHEAD AS THE SFC HIGH OVER THE GREAT LAKES
THURSDAY MORNING SHIFTS E TOWARDS THE ATLANTIC.
ALTHOUGH WITH DIFFERING TIMING...THERE ARE INDICATIONS THAT A LOW IN
THE SW FLOW WILL BE ABLE TO EJECT UP ACROSS THE N PLAINS ON
THURSDAY. THE 10/12Z ECMWF SOLUTION FOLLOWS SIMILARLY TO THE
CANADIAN...WHILE THE GFS KEEPS THE SYSTEM A WHOLE LOT WEAKER AND
FARTHER TO THE S. CURRENTLY RUNNING WITH SLIGHT CHANCE TO LOW CHANCE
POPS. GIVEN THE UNCERTAINTY WITH THIS 100 PLUS HR FCST...THIS SEEMS
REASONABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 137 PM EDT SUN MAY 10 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. INITIALLY...WILL
NEED TO DEAL WITH AREAS OF LOW CLOUDS/MVFR CIGS ACROSS THE AREA. AS
LOW-LEVEL WINDS VEER TO A MORE DOWNSLOPING EASTERLY DIRECTION AT
KIWD...EXPECT MVFR CIGS TO LIFT TO VFR THIS AFTN. MEANWHILE...WITH
BACK EDGE OF MVFR CIGS RAPIDLY APPROACHING KCMX FROM THE E...VFR
CONDITIONS WILL LIKELY DEVELOP THERE THIS AFTN. AT KSAW...LARGE AREA
OF MVFR CIGS TO THE E AND NE SUGGESTS MVFR CIGS MAY HOLD THRU THE
AFTN...BUT NOT OUT OF THE QUESTION THAT IMPROVEMENT TO VFR COULD
OCCUR LATE AFTN. TONIGHT...LOW PRES SYSTEM MOVING NE THRU THE PLAINS
WILL SWING SHRA NE INTO THE UPPER LAKES...MAINLY LATE TONIGHT/MON
MORNING. WHILE KSAW MAY REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF
PCPN...VFR CONDITIONS MAY LINGER THIS EVENING AT KIWD AND POTENTIALLY
THRU THE NIGHT AT KCMX. WITH THE ARRIVAL OF THE -SHRA...EXPECT A
TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS. UPSLOPE
FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT KCMX/KSAW BY
LATE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN MAY 10 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS
HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH
THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS
LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE
WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE
WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE
THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON
AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE
AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE
REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO
20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E
TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
138 PM EDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN MAY 10 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW
FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE
SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS
DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION.
WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW
CLOUDS BACK INTO NRN UPPER MI.
TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO
BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR.
HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT
CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP.
OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE
EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE
CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD
OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN
HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE
READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S.
TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE
POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY
12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE
STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN
INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED
OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT
SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM EDT SUN MAY 10 2015
MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE
MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS
OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE
RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE
WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS.
MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E
THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR
SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND
THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING
OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE
FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT
UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST
PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT
FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT
RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN
MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E
COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN
TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING
FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON
SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT
WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE
SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS
OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND
THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN
ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY
ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING
E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING.
THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM
CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER
MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF
THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND
OCCLUDED FNT.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE
N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE
ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE
UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL
FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL
BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE
40 OVER THE HIER TERRAIN AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END
LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO
FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING
HI...WHERE WINDS WL BE LIGHTER LONGER.
WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF
SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT
LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE
SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH
LKS AND BRING COOLER WX TO THE NEARSHORE AREAS.
WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE
TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE
VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE
UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR
THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 137 PM EDT SUN MAY 10 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. INITIALLY...WILL
NEED TO DEAL WITH AREAS OF LOW CLOUDS/MVFR CIGS ACROSS THE AREA. AS
LOW-LEVEL WINDS VEER TO A MORE DOWNSLOPING EASTERLY DIRECTION AT
KIWD...EXPECT MVFR CIGS TO LIFT TO VFR THIS AFTN. MEANWHILE...WITH
BACK EDGE OF MVFR CIGS RAPIDLY APPROACHING KCMX FROM THE E...VFR
CONDITIONS WILL LIKELY DEVELOP THERE THIS AFTN. AT KSAW...LARGE AREA
OF MVFR CIGS TO THE E AND NE SUGGESTS MVFR CIGS MAY HOLD THRU THE
AFTN...BUT NOT OUT OF THE QUESTION THAT IMPROVEMENT TO VFR COULD
OCCUR LATE AFTN. TONIGHT...LOW PRES SYSTEM MOVING NE THRU THE PLAINS
WILL SWING SHRA NE INTO THE UPPER LAKES...MAINLY LATE TONIGHT/MON
MORNING. WHILE KSAW MAY REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF
PCPN...VFR CONDITIONS MAY LINGER THIS EVENING AT KIWD AND POTENTIALLY
THRU THE NIGHT AT KCMX. WITH THE ARRIVAL OF THE -SHRA...EXPECT A
TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS. UPSLOPE
FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT KCMX/KSAW BY
LATE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN MAY 10 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS
HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH
THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS
LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE
WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE
WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE
THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON
AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE
AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE
REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO
20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E
TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
755 AM EDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN MAY 10 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW
FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE
SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS
DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION.
WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW
CLOUDS BACK INTO NRN UPPER MI.
TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO
BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR.
HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT
CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP.
OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE
EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE
CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD
OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN
HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE
READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S.
TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE
POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY
12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE
STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN
INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED
OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT
SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM EDT SUN MAY 10 2015
MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE
MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS
OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE
RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE
WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS.
MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E
THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR
SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND
THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING
OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE
FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT
UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST
PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT
FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT
RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN
MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E
COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN
TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING
FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON
SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT
WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE
SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS
OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND
THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN
ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY
ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING
E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING.
THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM
CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER
MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF
THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND
OCCLUDED FNT.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE
N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE
ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE
UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL
FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL
BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE
40 OVER THE HIER TERRAIN AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END
LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO
FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING
HI...WHERE WINDS WL BE LIGHTER LONGER.
WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF
SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT
LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE
SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH
LKS AND BRING COOLER WX TO THE NEARSHORE AREAS.
WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE
TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE
VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE
UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR
THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 748 AM EDT SUN MAY 10 2015
LOW-LEVEL EASTERLY UPSLOPE WINDS WILL FAVOR MVFR CIGS AT SAW UNTIL
WINDS VEER MORE TO THE E WHEN SOME IMPROVEMENT TO VFR IS EXPECTED.
VFR CONDITIONS AT CMX ARE EXPECTED TO GIVE WAY MVFR AS WINDS BECOME
MORE EASTERLY WHICH WILL DRAW IN MORE UPSTREAM LOW LEVEL MOSITURE.
WINDS VEERING TO ENE AT IWD WILL BE LESS FAVORABLE FOR LOWER CIGS.
SO...VFR CONDITIONS SHOULD PERSIST UNTIL AT LEAST LATER IN THE
AFTERNOON. SOME LIGHT RAIN MAY MOVE INTO IWD BY LATE THIS EVENING AND
LATE TONIGHT AT SAW WHICH WILL HELP LOWER CIGS BACK INTO THE MVFR
RANGE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN MAY 10 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS
HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH
THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS
LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE
WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE
WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE
THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON
AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE
AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE
REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO
20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E
TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT
/7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
459 AM EDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 457 AM EDT SUN MAY 10 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A DEEP MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS WITH A CLOSED LOW OVER NE CO RESULTING IN SSW
FLOW FROM THE PLAINS TO THE UPPER MS VALLEY AND WRN LAKES. AT THE
SFC...HIGH PRES WAS LOCATED OVER NW ONTARIO WHILE LOW PRES WAS
DEVELOPING OVER THE CNTRL PLAINS BRINGING NE WINDS TO THE REGION.
WITH THE LOSS OF DAYTIME MIXING...THE NE WINDS HAVE DRAWN AREAS OF LOW
CLOUDS BACK INTO NRN UPPER MI.
TODAY...SO FAR...THE LOW LEVEL MOISTURE HAS NOT BEEN THICK ENOUGH TO
BRING ANY DRIZZLE INTO AREAS DOWNWIND OF LAKE SUPERIOR.
HOWEVER...SIMILAR TO YESTERDAY...THE LOW LEVEL MODELS SUGGEST THAT
CIGS MAY LOWER ENOUGH WITH UPSLOPE FLOW FOR SOME DRIZZLE TO DEVELOP.
OTHERWISE...SHRA/TSRA ASSOCIATED WITH A SHRTWV NEAR SRN LAKE MI ARE
EXPECTED TO REMAIN WELL TO THE SOUTH OF UPPER MI. MODELS WERE
CONSISTENT IN KEEPING ANY PCPN SUPPORTED BY WAA/ISENTROPIC LIFT AHEAD
OF THE PLAINS LOW TO THE WEST OF THE CWA. THE NE WINDS WILL AGAIN
HOLD TEMPS OVER THE NORTH INTO THE UPPER 40S AND LOWER 50S WHILE
READINGS OVER THE SOUTH AND EAST CLIMB INTO THE MID TO UPPER 50S.
TONIGHT...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT WITH THE
POSITION/STRENGTH OF THE MID LEVEL LOW INTO THE ERN DAKOTAS BY
12Z/MON WITH A SFC TROUGH THROUGH SRN MN. THIS TRACK WOULD KEEP THE
STRONGEST ISENTROPIC LIFT AND DEEP LAYER QVECTOR CONV FROM NRN MN
INTO WRN UPPER MI. EVEN THOUGH THE HIGHEST POPS/QPF ARE EXPECTED
OVER THE WEST...MOISTURE TRANSPORT AND LIFT NORTH OF THE WARM FRONT
SHOULD BRING PCPN INTO MOST OF THE SW HALF OF THE CWA AFT 06Z.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM EDT SUN MAY 10 2015
MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE
MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS
OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE
RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE
WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS.
MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E
THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR
SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND
THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING
OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE
FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT
UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST
PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT
FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT
RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN
MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E
COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN
TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING
FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON
SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT
WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE
SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS
OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND
THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN
ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY
ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING
E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING.
THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM
CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER
MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF
THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND
OCCLUDED FNT.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE
N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE
ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE
UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL
FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL
BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE
40 OVER THE HIER TERRAIN AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END
LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO
FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING
HI...WHERE WINDS WL BE LIGHTER LONGER.
WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF
SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT
LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE
SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH
LKS AND BRING COOLER WX TO THE NEARSHORE AREAS.
WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE
TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE
VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE
UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR
THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 121 AM EDT SUN MAY 10 2015
LOW-LEVEL EASTERLY UPSLOPE WINDS WILL CAUSE MVFR CIGS AT CMX AND SAW
WHICH WILL LAST THROUGH THE FORECAST PERIOD. IWD WILL HAVE THE SAME
THING HAPPEN...BUT IT WILL BE BY SUNDAY MORNING. MVFR CONDITIONS
WILL THEN LAST ALL OF SUNDAY AT ALL SITES WITH NORTHEAST/EAST
UPSLOPE FLOW. DID PUT SOME RAIN WITH NEXT SYSTEM COMING IN SUN
EVENING AT IWD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT SUN MAY 10 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE NRN LAKEESUPPER LAKES AS
HIGH PRES REMAINS ACROSS NRN ONTARIO AND LOW PRES MOVES NE THROUGH
THE PLAINS. AS A RESULT NE TO E WINDS WILL BE ON THE INCREASE ACROSS
LAKE SUPERIOR. THE INCREASE IN WINDS WILL BE MOST NOTABLE OVER THE
WRN PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW WILL ENHANCE THE WINDS. EXPECT ENE
WINDS TO REACH GALE FORCE OVER PORTIONS OF WRN LAKE SUPERIOR LATE
THIS MORNING OR EARLY AFTERNOON AND THEN CONTINUE THROUGH MON
AFTERNOON BEFORE DIMINISHING MON EVENING AS THE LOW SHIFTS E OF THE
AREA WITH BACKING WINDS AND A WEAKENING PRES GRADIENT. ACROSS THE
REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT TODAY AND TO
20-30KT TONIGHT INTO MON. WINDS WILL THEN DECREASE FROM W TO E
TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT
/7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 AM EDT SUN MAY 10 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 431 PM EDT SAT MAY 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN AMPLIFIED RIDGE ALONG
THE W COAST OF NAMERICA. DOWNSTREAM...TROF EXTENDS FROM HUDSON BAY
TO THE SRN ROCKIES. ENERGY IN THE TROF IS SPLIT WITH THE NRN STREAM
PORTION EXTENDING AS FAR S AS MT/ND. FARTHER S...VIGOROUS MID LEVEL
LOW IN THE SRN STREAM PORTION OF THE TROF IS CENTERED NEAR THE 4
CORNERS. CLOSER TO HOME...LOW CLOUDS HAVE DOMINATED MUCH OF THE FCST
AREA TODAY...THOUGH IN THE LAST COUPLE OF HRS...SATELLITE IMAGERY
SHOWS HIGH EARLY MAY SUN ANGLE BEGINNING TO MIX OUT THE MOISTURE
FROM THE EDGES. CLOUDS AND -DZ ARE HOLDING TOUGH OVER NCNTRL UPPER
MI WHERE STRONGEST UPSLOPE IS OCCURRING.
FCST IN THE SHORT TERM WILL REVOLVE AROUND CLOUD TRENDS TONIGHT AND
THEN POTENTIAL OF -SHRA SUN AS MID LEVEL LOW LIFTS INTO SD/NEBRASKA
WITH WEAK LEAD ENERGY EJECTING INTO THE WRN GREAT LAKES.
OF IMMEDIATE CONCERN IS THE LOW CLOUDS AND PATCHY -DZ. SEVERAL MORE
HRS OF DAYTIME HEATING WILL CONTINUE TO EAT AWAY AT THE LOW CLOUDS
FROM THE EDGES...BUT HAVE LOW CONFIDENCE IN ALL OF THE CLOUDS
DISSIPATING OVER NCNTRL UPPER MI. INCREASINGLY DIFFLUENT LOW-LEVEL
FLOW OVER THE LAKE AS LAKE BREEZE CIRCULATION CONTINUES TO INCREASE
FOR A FEW MORE HRS WILL ALSO WORK TO AID CLEARING. FOR NOW...FCST
WILL REFLECT AN OPTIMISTIC TREND LATE AFTN/EARLY EVENING. AS A
RESULT...FAVORED THE LOWER SIDE OF GUIDANCE FOR MINS TONIGHT...
ESPECIALLY W AND WELL INTO THE INTERIOR OVER THE CNTRL WHERE SKIES
ARE LIKELY TO HAVE LEAST CLOUDINESS FOR THE LONGEST PERIOD.
TRADITIONAL COLD SPOTS MAY FALL TO FREEZING. GIVEN THE ABUNDANCE OF
LOW CLOUDS NE AND E OF LAKE SUPERIOR...MAY SEE LOW CLOUDS INCREASE
AGAIN LATE IN THE NIGHT OVER THE CNTRL AND E AS LOW-LEVEL NE
FLOW CONTINUES.
IF LOW CLOUDS REDEVELOP INTO NCNTRL UPPER MI LATE TONIGHT...MAY HAVE
A REPEAT PERFORMANCE OF PATCHY -DZ SUN MORNING. OTHERWISE...THE
TREND FROM ALL MODELS IS DEFINITELY FOR A DRIER LOOK ON SUN WITH
SHORTWAVE SWINGING NE INTO THE GREAT LAKES AHEAD OF MAIN SYSTEM
MOVING OUT OVER THE WRN PLAINS. SHORTWAVE IN QUESTION IS AIDING
CONVECTION CURRENTLY OVER THE SRN PLAINS. MODELS INDICATE TRACK OF
THIS SHORTWAVE PASSING TO THE SE OF HERE. GIVEN THE LACK OF DEEP
LAYER FORCING AND MUCH WEAKER ISENTROPIC ASCENT ACROSS THE FCST AREA
COMPARED TO PREVIOUS MODEL RUNS...THE DRIER TREND APPEARS
REASONABLE. HAVE SCALED BACK POPS CONSIDERABLY FOR SUN WITH SCHC
POPS ONLY OVER THE SCNTRL IN THE AFTN. WITH THE A DRIER FCST...
RAISED MAX TEMPS SLIGHTLY. EXPECT MOSTLY 40S NEAR LAKE SUPERIOR...
50S INLAND. MAY REACH 60F IN A FEW SPOTS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 359 AM EDT SUN MAY 10 2015
MAIN FCST FOCUS IN THE LONG TERM REMAINS ON POPS/QPF/PTYPE IN THE
MON THRU TUE NGT TIME AS CLOSED LO NOW MOVING INTO THE WRN PLAINS
OPENS UP AND LIFTS NE THRU THE UPR LKS. BLO NORMAL TEMPS WL BE THE
RULE INTO WED. EXPECT A WARMING TREND DURING THE SECOND HALF OF THE
WEEK AS AN UPR RDG REBOUNDS INTO THE GREAT LKS.
MON/MON NGT...AS CLOSED LO IN THE NRN PLAINS OPENS UP AND SLIDES E
THRU THE UPR LKS...A SFC LO PRES IS FCST TO DVLP ON MON NEAR
SCENTRAL UPR MI AT THE TRIPLE POINT OF OCCLUDED SFC LO IN MN AND
THEN DRIFT E INTO SE CANADA BY 12Z TUE...WHILE SLOWLY WEAKENING
OCCLUDED FNT/LO PRES TROF HANG BACK INTO UPR MI. THE TRACK OF THESE
FEATURES AND INTERACTION BTWN ACCOMPANYING DYNAMIC FORCING/DIFFLUENT
UPPER FLOW AND PWAT AOA 1 INCH INDICATE THERE WILL BE AT LEAST
PERIODS OF RA OR SHOWERS. ALTHOUGH THE 00Z NAM/GFS SHOW A BIT
FARTHER S AXIS OF THE OCCLUDED FNT/TRIPLE POINT LO TRACK...RECENT
RUNS OF THE ECMWF...WHICH IS SUPPORTED BY THE 18Z GFS/00Z CNDN
MODELS AND MORE IN LINE WITH HI AMPLITUDE UPR RDG AXIS ALONG THE E
COAST...HAVE BEEN MOST CONSISTENT ON THE DETAILS AND SHOW A MORE NRN
TRACK. THIS GUIDANCE SHOWS THE SHRTWV/ACCOMPANYING H85-7 LO MOVING
FAR ENUF TO THE N SO THAT THE MAIN COLD CONVEYOR BELT MSTR RIBBON
SETS UP TO THE N OF UPR MI. IN THIS SCENARIO...THE MORE TRANSIENT
WARM CONVEYOR BELT MSTR RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE
SHRTWV WL BE THE MAIN FORCING MECHANISM FOR THE HIER POPS. THIS AXIS
OF HIER MSTR IS FCST TO BE ALIGNED INTO WRN UPR MI ON MON MRNG AND
THEN TO DRIFT E ACRS THE REST OF THE CWA DURING THE DAY ON MON IN
ADVANCE OF WELL DEFINED DRY SLOTTING THAT IS FCST TO REACH NEWBERRY
ARND 00Z TUE. FCST ON MON WL SHOW THE HIER CATEGORICAL POPS SHIFTING
E AND THEN DIMINISHING TO CHC POPS WITH ARRIVAL OF THE DRY SLOTTING.
THE ECMWF INDICATES 0.25-0.50 INCH OF RAIN FALLING UNDER THE WARM
CONVEYOR BELT MSTR RIBBON. ON MON NGT...SHOWED AN INCRS IN POPS OVER
MAINLY THE W WITH INFLUX OF DEEPER MSTR ACCOMPANYING THE PASSAGE OF
THE SHRTWV IN THE PRESENCE OF SHARP CYC LLVL FLOW ORIENTED ARND
OCCLUDED FNT.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS AND WEAKENING LO PRES TROF/FADING OCCLUDED FNT WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NW IMPACTED BY THE
N WIND LEFT IN THE WAKE OF THE DEPARTING SFC LO TO THE E. THE
ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C MAY ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BUT SINCE SUFFICIENTLY COLD AIR WL NOT ARRIVE
UNTIL AFTER 12Z TUE...DAYTIME INSOLATION SHOULD LIMIT THE POTENTAIL
FOR MUCH IF ANY SN ACCUM EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL
BE UP TO 20 DEGREES BLO NORMAL WITH READINGS NOT RISING MUCH ABOVE
40 OVER THE HIER TERRAIN AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA AND END
LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN TEMPS ARE LIKELY TO
FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER TO THE INCOMING
HI...WHERE WINDS WL BE LIGHTER LONGER.
WED...SFC HI PRES UNDER BLDG UPR RDG WL BRING A GOOD DEAL OF
SUNSHINE. WITH H85 TEMPS RISING TO 1 TO 2C...EXPECT MAX TEMPS TO AT
LEAST APRCH 60 AWAY FM THE COOLING INFLUENCE OF THE LKS. SINCE THE
SFC HI IS FCST TO BE NEARLY OVHD...LK BREEZES SHOULD DVLP OFF BOTH
LKS AND BRING COOLER WX TO THE NEARSHORE AREAS.
WED NGT THRU SAT...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE LONGER RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR UPR MI. BUT THERE ARE
TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO THE
VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU THE
UPR RDG OVER THE WRN LKS. WE RELY ON THE MODEL CONSENSUS FCST FOR
THIS PERIOD. TEMPS WL RETURN AOA NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 121 AM EDT SUN MAY 10 2015
LOW-LEVEL EASTERLY UPSLOPE WINDS WILL CAUSE MVFR CIGS AT CMX AND SAW
WHICH WILL LAST THROUGH THE FORECAST PERIOD. IWD WILL HAVE THE SAME
THING HAPPEN...BUT IT WILL BE BY SUNDAY MORNING. MVFR CONDITIONS
WILL THEN LAST ALL OF SUNDAY AT ALL SITES WITH NORTHEAST/EAST
UPSLOPE FLOW. DID PUT SOME RAIN WITH NEXT SYSTEM COMING IN SUN
EVENING AT IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 PM EDT SAT MAY 9 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE UPPER LAKES DURING THE
NEXT 24-48HRS AS HIGH PRES REMAINS ACROSS MANITOBA/NRN ONTARIO AND
LOW PRES MOVES NE ACROSS THE PLAINS. AS A RESULT NE TO E WINDS WILL
BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL
BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL
CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL
ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER
PORTIONS OF WRN LAKE SUPERIOR LATE MORNING/EARLY AFTN ON SUN AND
THEN CONTINUE THRU MON AFTN BEFORE DIMINISHING MON EVENING AS THE
LOW SHIFTS E OF THE AREA/WINDS BACK AND PRES GRADIENT WEAKENS.
ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT
SUN AND TO 20-30KT SUN NIGHT/MON. WINDS WILL THEN DECREASE FROM W TO
E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS THRU THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT
/7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
121 AM EDT SUN MAY 10 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 431 PM EDT SAT MAY 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN AMPLIFIED RIDGE ALONG
THE W COAST OF NAMERICA. DOWNSTREAM...TROF EXTENDS FROM HUDSON BAY
TO THE SRN ROCKIES. ENERGY IN THE TROF IS SPLIT WITH THE NRN STREAM
PORTION EXTENDING AS FAR S AS MT/ND. FARTHER S...VIGOROUS MID LEVEL
LOW IN THE SRN STREAM PORTION OF THE TROF IS CENTERED NEAR THE 4
CORNERS. CLOSER TO HOME...LOW CLOUDS HAVE DOMINATED MUCH OF THE FCST
AREA TODAY...THOUGH IN THE LAST COUPLE OF HRS...SATELLITE IMAGERY
SHOWS HIGH EARLY MAY SUN ANGLE BEGINNING TO MIX OUT THE MOISTURE
FROM THE EDGES. CLOUDS AND -DZ ARE HOLDING TOUGH OVER NCNTRL UPPER
MI WHERE STRONGEST UPSLOPE IS OCCURRING.
FCST IN THE SHORT TERM WILL REVOLVE AROUND CLOUD TRENDS TONIGHT AND
THEN POTENTIAL OF -SHRA SUN AS MID LEVEL LOW LIFTS INTO SD/NEBRASKA
WITH WEAK LEAD ENERGY EJECTING INTO THE WRN GREAT LAKES.
OF IMMEDIATE CONCERN IS THE LOW CLOUDS AND PATCHY -DZ. SEVERAL MORE
HRS OF DAYTIME HEATING WILL CONTINUE TO EAT AWAY AT THE LOW CLOUDS
FROM THE EDGES...BUT HAVE LOW CONFIDENCE IN ALL OF THE CLOUDS
DISSIPATING OVER NCNTRL UPPER MI. INCREASINGLY DIFFLUENT LOW-LEVEL
FLOW OVER THE LAKE AS LAKE BREEZE CIRCULATION CONTINUES TO INCREASE
FOR A FEW MORE HRS WILL ALSO WORK TO AID CLEARING. FOR NOW...FCST
WILL REFLECT AN OPTIMISTIC TREND LATE AFTN/EARLY EVENING. AS A
RESULT...FAVORED THE LOWER SIDE OF GUIDANCE FOR MINS TONIGHT...
ESPECIALLY W AND WELL INTO THE INTERIOR OVER THE CNTRL WHERE SKIES
ARE LIKELY TO HAVE LEAST CLOUDINESS FOR THE LONGEST PERIOD.
TRADITIONAL COLD SPOTS MAY FALL TO FREEZING. GIVEN THE ABUNDANCE OF
LOW CLOUDS NE AND E OF LAKE SUPERIOR...MAY SEE LOW CLOUDS INCREASE
AGAIN LATE IN THE NIGHT OVER THE CNTRL AND E AS LOW-LEVEL NE
FLOW CONTINUES.
IF LOW CLOUDS REDEVELOP INTO NCNTRL UPPER MI LATE TONIGHT...MAY HAVE
A REPEAT PERFORMANCE OF PATCHY -DZ SUN MORNING. OTHERWISE...THE
TREND FROM ALL MODELS IS DEFINITELY FOR A DRIER LOOK ON SUN WITH
SHORTWAVE SWINGING NE INTO THE GREAT LAKES AHEAD OF MAIN SYSTEM
MOVING OUT OVER THE WRN PLAINS. SHORTWAVE IN QUESTION IS AIDING
CONVECTION CURRENTLY OVER THE SRN PLAINS. MODELS INDICATE TRACK OF
THIS SHORTWAVE PASSING TO THE SE OF HERE. GIVEN THE LACK OF DEEP
LAYER FORCING AND MUCH WEAKER ISENTROPIC ASCENT ACROSS THE FCST AREA
COMPARED TO PREVIOUS MODEL RUNS...THE DRIER TREND APPEARS
REASONABLE. HAVE SCALED BACK POPS CONSIDERABLY FOR SUN WITH SCHC
POPS ONLY OVER THE SCNTRL IN THE AFTN. WITH THE A DRIER FCST...
RAISED MAX TEMPS SLIGHTLY. EXPECT MOSTLY 40S NEAR LAKE SUPERIOR...
50S INLAND. MAY REACH 60F IN A FEW SPOTS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM EDT SAT MAY 9 2015
RAIN ASSOCIATED WITH AN UPPER SHORTWAVE AND SFC LOW WILL MOVE INTO
THE AREA FROM THE SW SUN NIGHT AND CONTINUE INTO MON. AS THE SFC LOW
SHIFTS ACROSS THE AREA MON EVENING INTO MON NIGHT...SHIFTING A DRY
SLOT ACROSS MOST OF THE CWA. THIS WILL DIMINISH THE RAIN UNTIL
MOISTURE MOVES BACK IN FROM THE W ON THE BACK SIDE OF THE SYSTEM
LATE MON NIGHT INTO TUE. MUCH COLDER AIR SURGES IN ON TUE WITH 850MB
TEMPS DROPPING TO AROUND -15C OVER AT LEAST NWRN UPPER MI BY 00Z
WED. THIS WILL SUPPORT A CHANGE OVER TO MIXED PRECIP OVER THE
NRN/NWRN PORTIONS OF UPPER MI ON TUE AND MOSTLY SNOW TUE NIGHT. THE
FORCING TUE INTO TUE NIGHT WILL COME FROM BOTH THE WRAP AROUND FROM
THE LOW AND FROM A WEAK SHORTWAVE MOVING IN FROM THE NW...WITH ONLY
LIGHT PRECIP EXPECTED AND LITTLE TO NO SNOW ACCUMULATION.
MON WILL SEE HIGHS IN THE 50S INLAND FROM LAKE SUPERIOR AND IN THE
40S ALONG THE BIG LAKE. TUE LOOKS TO BE THE COLDEST DAY OF THE WEEK
WITH HIGHS BARELY REACHING 50F OVER THE SCENTRAL AND IN THE 40S
ELSEWHERE. IT WILL ALSO BE CLOUDY AND BREEZY MAKING IT FEEL EVEN
COLDER. TEMPS WILL BE TRICKY TUE NIGHT AS CLOUDS WILL BE CLEARING
AND THE COLDER AIRMASS REMAINS. SHOULD SEE LOWS NEAR OR BELOW
FREEZING WITH THE CURRENT EXPECTATION OF CLOUDS CLEARING BY SUNRISE
WED...BUT MUCH COLDER TEMPS ARE POSSIBLE IF THE CLOUDS CLEAR EARLIER.
THE AIRMASS WILL BEGIN TO MODERATE ON WED AS 850MB TEMPS INCREASE TO
AROUND 0C BY 00Z THU WITH A 1031MB SFC HIGH MOVING OVER THE CWA.
SHOULD BE AN OVERALL PLEASANT DAY WITH SUNNY SKIES...LIGHT WINDS AND
HIGHS IN THE 50S INLAND TO UPPER 40S RIGHT ALONG LAKE SUPERIOR.
SIGNIFICANT UNCERTAINTY EXISTS IN THE THU-SAT PORTION OF THE
FORECAST AS MODELS CONTINUITY AND AGREEMENT IS POOR. THE GENERAL
IDEA IS UPPER RIDGING BUILDING INTO OR NEAR THE REGION...PROMOTING
WARMER TEMPS. RAIN CAN NOT BE RULED OUT. LET CONSENSUS OF GUIDANCE
HANDLE THIS PART OF THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 121 AM EDT SUN MAY 10 2015
LOW-LEVEL EASTERLY UPSLOPE WINDS WILL CAUSE MVFR CIGS AT CMX AND SAW
WHICH WILL LAST THROUGH THE FORECAST PERIOD. IWD WILL HAVE THE SAME
THING HAPPEN...BUT IT WILL BE BY SUNDAY MORNING. MVFR CONDITIONS
WILL THEN LAST ALL OF SUNDAY AT ALL SITES WITH NORTHEAST/EAST
UPSLOPE FLOW. DID PUT SOME RAIN WITH NEXT SYSTEM COMING IN SUN
EVENING AT IWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 PM EDT SAT MAY 9 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE UPPER LAKES DURING THE
NEXT 24-48HRS AS HIGH PRES REMAINS ACROSS MANITOBA/NRN ONTARIO AND
LOW PRES MOVES NE ACROSS THE PLAINS. AS A RESULT NE TO E WINDS WILL
BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL
BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL
CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL
ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER
PORTIONS OF WRN LAKE SUPERIOR LATE MORNING/EARLY AFTN ON SUN AND
THEN CONTINUE THRU MON AFTN BEFORE DIMINISHING MON EVENING AS THE
LOW SHIFTS E OF THE AREA/WINDS BACK AND PRES GRADIENT WEAKENS.
ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT
SUN AND TO 20-30KT SUN NIGHT/MON. WINDS WILL THEN DECREASE FROM W TO
E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS THRU THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ THIS MORNING TO 8 PM EDT
/7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
748 PM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 734 PM CDT MON MAY 11 2015
UPDATED POPS AS CURRENT RADAR TRENDS SHOW PRECIPITATION INCREASING
IN COVERAGE AND INTENSITY ACROSS THE FORECAST AREA. AN AREA OF
CONVECTIVE SHOWERS WITH REFLECTIVITY VALUES OVER 40 DBZ HAS
DEVELOPED ABOUT 30 MILES NORTH OF DULUTH...ON THE LEADING EDGE OF
THE H50 LOW/VORT MAX AND AN REGION OF LOW LEVEL FRONTOGENESIS
DEPICTED IN THE LATEST RUC MESO ANALYSIS. ANTICIPATE ECHOES TO
CONTINUE TO INTENSIFY OVER THE IRON RANGE/ARROWHEAD AS THE VORT
MAX TRANSLATES EAST ACROSS THE FORECAST AREA. AT THIS TIME THE
PRECIP TYPE BEING REPORTED BY AUTOMATED STATIONS IS ALL RAIN.
HOWEVER...AS PROFILES COOL THROUGH THE EVENING THE RAIN IS
EXPECTED TO CHANGE OVER TO SNOW FOR AT LEAST THE NORTHERN PORTION
OF MN.
ALSO ADDED AREAS OF FOG ALONG SOUTH SHORE OF LAKE SUPERIOR WHERE
SURFACE OBSERVATIONS AND SPOTTERS HAVE REPORTED VISIBILITY OF LESS
THAN A HALF MILE AT TIMES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 328 PM CDT MON MAY 11 2015
A CLOSED AND NEARLY STACKED UPPER LOW OVER MINNESOTA WILL CONTINUE
SHOWERS OVER THE REGION TONIGHT AS IT SLOWLY MOVES EAST. THE
STRONGEST LIFT NORTH OF THE BAROCLINIC ZONE WILL BE IN NORTHERN
MINNESOTA BUT CANNOT RULE OUT SHOWERS ACROSS REST OF THE FORECAST
AREA. COLD AIR ADVECTION BEHIND THE LOW LATER TONIGHT COULD RESULT
IN SNOW SHOWERS. BUT WITH THE WET GROUND, DO NOT EXPECT MUCH
ACCUMULATION. THERE WILL BE A GRADUAL END TO ANY SHOWERS SLOWLY FORM
WEST TO EAST TUESDAY WITH SFC HIGH PRESSURE BUILDING OVER THE
AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 328 PM CDT MON MAY 11 2015
THE NORTHLAND CAN EXPECT A BIT OF WET PATTERN OVER THE NEXT WEEK
WITH SEVERAL OPPORTUNITIES FOR RAIN.
HIGH PRESSURE WILL BE OVER THE NORTHLAND TUESDAY NIGHT AND WILL MAKE
FOR A COOL AND RELATIVELY CLEAR NIGHT. TEMPERATURES WILL DIP INTO
THE LOWER 30S AND UPPER 20S. THERE WILL BE INCREASING CLOUD COVER
FROM THE WEST LATE TUESDAY NIGHT AND WEDNESDAY AS A MID LEVEL
FRONTOGENETICAL BAND MOVES INTO THE NORTHLAND. THIS FRONTOGENETICAL
BAND WILL LIKELY RESULT IN RAINS SHOWERS FOR PARTS OF THE NORTHLAND
WEDNESDAY AND WEDNESDAY NIGHT. THE SW FORECAST AREA HAS THE BEST
CHANCE OF RAIN.
A LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS WEDNESDAY NIGHT WILL
LIFT INTO THE NORTHERN PLAINS THURSDAY AND THURSDAY NIGHT. THE
MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THIS WILL BRING MORE RAIN
TO THE NORTHLAND THURSDAY INTO FRIDAY. THE SOUTHERN FORECAST AREA
HAS THE BEST CHANCE OF RAIN WITH THE PASSAGE OF THIS SYSTEM.
WEAK HIGH PRESSURE WILL GIVE ANOTHER SHORT BREAK BETWEEN WEATHER
SYSTEMS LATE FRIDAY AND SATURDAY. A LOW IN THE NORTHERN PLAINS WILL
LIFT A WARM FRONT INTO THE UPPER MIDWEST. THE GFS AND ECMWF ARE IN
RELATIVELY GOOD AGREEMENT THAT THE NORTHLAND WILL SEE SHOWERS AND
STORMS LATE SATURDAY INTO EARLY MONDAY WITH THE PASSAGE OF THIS
SYSTEM. THE SOUTHERN FORECAST AREA HAS THE BEST CHANCE OF SEEING
THUNDER SINCE THE WARM FRONT MIGHT GET SHUNTED SOUTH BECAUSE OF COOL
EASTERLY FLOW FROM LAKE SUPERIOR AND ONTARIO. HOWEVER...THERE COULD
BE ELEVATED CONVECTION NORTH OF THE WARM FRONT...BUT THOUGHT IT TOO
EARLY TO INCLUDE THUNDER OVER ALL OF THE NORTHLAND.
TEMPERATURES WILL REMAIN COOL FOR THE MIDDLE OF THE WEEK...BUT WILL
LIKELY REBOUND TO CLOSE TO NORMAL BY THIS WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 734 PM CDT MON MAY 11 2015
WIDESPREAD RAIN...MIXING WITH SNOW AT TIMES AND LIFR/IFR
CONDITIONS OVERNIGHT. CEILINGS WILL GRADUALLY IMPROVE FROM THE
WEST THROUGH TUESDAY MORNING AS COOLER AND DRIER AIR FILTERS IN
THE REGION. HOWEVER...THERE WILL BE SUFFICIENT INSTABILITY AND
MOISTURE TO SUPPORT SCATTERED SHOWERS THROUGH MUCH OF THE DAY.
A FEW OF THE SHOWERS WILL HAVE THE POTENTIAL TO CONTAIN
GRAUPEL/SMALL HAIL AND GUSTY NORTH WINDS TO 30 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 35 49 34 50 / 80 40 10 60
INL 32 49 30 56 / 70 30 10 0
BRD 35 55 37 52 / 80 20 10 60
HYR 37 49 31 56 / 80 50 10 40
ASX 35 46 32 52 / 80 50 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ121-
141>148.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT TUESDAY FOR LSZ140.
&&
$$
UPDATE...GRANING
SHORT TERM...CLC
LONG TERM...GROCHOCINSKI
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS DULUTH MN
357 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 357 AM CDT SUN MAY 10 2015
WINDY AND COOLER TODAY WITH RAIN ON THE WAY. GENERALLY HAVE SLOWED
DOWN ONSET OF PRECIPITATION DUE TO THE MUCH DRIER THAN ORIGINALLY
ANTICIPATED AIR ACROSS THE REGION...BUT RAINFALL WILL INDEED SPREAD
ACROSS THE ENTIRE REGION BY THIS EVENING. MOST RAIN WILL FALL
OVERNIGHT TONIGHT...BUT CONTINUE THROUGH MONDAY. TOTAL RAINFALL
VALUES UP TO AN INCH OR SO ACROSS MUCH OF NORTHEAST MINNESOTA
THROUGH MONDAY EVENING...WITH LESSER AMOUNTS OF A QUARTER INCH TO A
HALF INCH OVER MOST OF NORTHWEST WISCONSIN. THERE IS STILL A CHANCE
FOR A FEW RUMBLES OF THUNDER TONIGHT...BUT WIDESPREAD THUNDERSTORMS
ARE NOT EXPECTED WITH THIS SYSTEM.
ON THE SYNOPTIC SCALE A VERY DYNAMIC PATTERN ACROSS THE NATIONS
MID-SECTION WITH AN UPPER LEVEL LOW OVER NORTHEAST COLORADO MOVING
NORTH INTO THE CENTRAL/NORTHERN PLAINS TODAY INTO TOMORROW. THE
ASSOCIATED SURFACE LOW OVER THE CENTRAL PLAINS WILL MOVE
NORTH-NORTHEAST INTO SOUTHERN MINNESOTA BY MONDAY MORNING...THEN
GRADUALLY WEAKEN AND MOVE EAST. WHILE THERE IS SOME LIGHT PRECIP
ONGOING THIS MORNING ACROSS THE BORDERLAND REGION DUE TO THE
ENTRANCE REGION OF THE H3 JET...THE MAIN EVENT WILL GRADUALLY ARRIVE
LATE TODAY AND REALLY INTENSIFY OVERNIGHT TONIGHT. NOSE OF A 100KT
H3 JET ASSOCIATED WITH THE UPPER LOW WILL MOVE INTO THE REGION THIS
EVENING...WITH THE BEST MID-LEVEL PVA ARRIVING TOWARDS MIDNIGHT AS
THE H5 LOW MOVES INTO THE CENTRAL/EASTERN DAKOTAS. WHILE THE SFC LOW
WILL JUST GRAZE THE SOUTHERN EDGE OF THE CWA ON MONDAY...THE
INCREASED PRESSURE GRADIENT CAUSED BY THE SFC LOW AND A STUBBORN
HIGH OVER NORTHERN MANITOBA/NORTHWEST ONTARIO WILL LEAD TO STRONG
EASTERLY WINDS TODAY INTO TOMORROW.
TODAY...CLOUDY AND WINDY...ESPECIALLY FROM THE TWIN PORTS WEST TO
THE BRAINERD LAKES REGION. LIGHT RAIN SHOWERS WILL GRADUALLY FROM
SOUTHWEST TO NORTHEAST. DO NOT EXPECT A STEADY RAIN TO DEVELOP JUST
YET...JUST SOME OFF AND ON LIGHT RAIN THROUGH THE DAY. WINDS WILL BE
THE MAIN STORY WITH GUSTY EAST-NORTHEASTERLY WINDS OF 10 TO 20 MPH
AND GUSTS UP TO 35 MPH OR SO. STRONGEST WINDS WILL BE IN THE TWIN
PORTS REGION WHERE A FEW GUSTS APPROACHING 45 MPH CANNOT BE RULED
OUT. HIGH TEMPERATURES WILL BE COOLER...IN THE LOW 40S BY LAKE
SUPERIOR TO THE LOW 50S IN NORTH CENTRAL MINNESOTA. WHILE COAST
WISCONSIN WILL BE LIMITED TO THE MID 40S TO LOW 50S...FURTHER INLAND
SUCH AS SAWYER AND PRICE COUNTY WILL WARM UP TO THE LOW 60S DUE TO A
COMBINATION OF LOW LEVEL WARM AIR ADVECTION AND DELAYED ONSET OF
THICK CLOUD COVER.
TONIGHT...RAIN...HEAVY AT TIMES. A FEW RUMBLES OF THUNDER DUE TO
ELEVATED CONVECTION MAINLY SOUTH OF HIGHWAY 2. SOME SNOW MAY MIX IN
ACROSS THE TIP OF THE ARROWHEAD AND ELSEWHERE ACROSS THE
REGION...BUT NO SNOW ACCUMULATION IS EXPECTED OVERNIGHT. EAST WINDS
WILL REMAIN WINDY AT 10 TO 20 MPH...STRONGEST ALONG THE COAST OF
LAKE SUPERIOR AND ESPECIALLY UP THE NORTH SHORE WHERE GUSTS TO 30
MPH CAN BE EXPECTED OVERNIGHT. TOTAL OVERNIGHT RAINFALL AMOUNTS OF A
HALF INCH TO THREE QUARTERS OF AN INCH...WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. TEMPERATURES FALLING TO THE MID TO UPPER 30S.
MONDAY...OFF AND ON RAIN CONTINUES. COOL WITH WINDS GRADUALLY
DECREASING. A DRY SLOT MAY WORK ITS WAY INTO THE INTERSTATE 35
CORRIDOR EAST ACROSS NORTHWEST WISCONSIN AND WINDS WILL TURN TO
BECOME OUT OF THE NORTHEAST AS THE SFC LOW MOVES EAST. TOTAL
RAINFALL THROUGH THE DAYTIME PERIOD /7AM TO 7PM/ AROUND A QUARTER TO
HALF INCH...POTENTIALLY LOWER IN AREAS SOUTH OF HIGHWAY 2 IF DRY
SLOT BUILDS IN EARLIER THAN ANTICIPATED. HIGHS COOLER AS COLD AIR
MOVES IN BEHIND THE LOW...IN THE LOW 40S ACROSS NORTHEAST MINNESOTA
AND INTO THE MID 50S TO NEAR 60S ACROSS PARTS OF NORTHWEST WISCONSIN.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 357 AM CDT SUN MAY 10 2015
MONDAY NIGHT AND TUESDAY THE SPRING STORM SYSTEM WILL SLOWLY MOVE
EAST OF THE AREA...WITH AN AREA OF FRONTOGENESIS THAT WILL AFFECT
MUCH OF THE FORECAST AREA MONDAY NIGHT AND EARLY TUESDAY. AT THIS
TIME...THE SYSTEM WILL BE PULLING COLDER AIR INTO NORTHERN MINNESOTA
FROM THE NORTH...WITH 850MB TEMPERATURES DROPPING TO AROUND -4 BY
TUESDAY MORNING. SURFACE TEMPERATURES WILL ALSO BE DOWN IN THE LOW
TO MID 30S...MAKING ACCUMULATING SNOW A REAL POSSIBILITY WITH THIS
SYSTEM. HOWEVER...THE RAINFALL THAT WILL COME BEFORE IT AND THE
RELATIVELY WARM SUBSOIL TEMPERATURES IN THE LOW 40S ARE GOING TO
CAUSE THE SNOW TO DO A LOT OF MELTING AS SOON AS IT HITS THE
GROUND...AND IS UNLIKELY TO LAST PAST NOON TUESDAY. AN INCH OR TWO
OF SNOW MAY FALL...BUT DUE TO MELTING AND COMPACTION WE ARE UNLIKELY
TO SEE MORE THAN AN INCH OF SNOW ON THE GROUND AT ANY TIME. WOULD
BE A LOT MORE EXCITED ABOUT SNOWFALL ACCUMULATIONS IF THE STRONG
FORCING WE SEE EARLIER IN THIS SYSTEM WERE TO OVERLAP WITH THE COLD
TEMPERATURES.
QUIETER CONDITIONS RETURN FOR TUESDAY NIGHT AND EARLY WEDNESDAY AS A
RIDGE OF HIGH PRESSURE BUILDS ACROSS THE AREA. WITH THE COLD AIR
BEHIND THE RETREATING LOW PRESSURE SYSTEM...TUESDAY NIGHT COULD BE
PRETTY COLD...WITH MINS IN THE LOW 30S AND EVEN UPPER 20S FOR A
LARGE PORTION OF THE FORECAST AREA. WE ARE STILL GETTING FREEZING
TEMPERATURES OFTEN ENOUGH...WE HAD TWO NIGHTS OF NEAR OR BELOW
FREEZING JUST 5-6 DAYS AGO...THAT WE ARE UNLIKELY TO BE ISSUING ANY
FROST/FREEZE HEADLINES FOR THIS EVENT.
ANOTHER STRONG SPRING STORM SYSTEM IS EXPECTED TO MOVE ACROSS THE
MIDWEST WEDNESDAY THROUGH FRIDAY...WITH MAINLY RAIN EXPECTED THROUGH
THE PERIOD. TEMPERATURES TO START OUT AS FAIRLY COOL WITH HIGHS
NEAR TO BELOW NORMAL WEDNESDAY...GRADUALLY WARMING TO ABOVE NORMAL
BY FRIDAY AS THE SYSTEM ADVECTS MORE WARM AIR INTO THE AREA THROUGH
THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1227 AM CDT SUN MAY 10 2015
AN AREA OF LOW PRESSURE WILL TRACK NORTHEASTWARDS TONIGHT FROM
EASTERN COLORADO THROUGH NEBRASKA...AND INTO SOUTHWEST MINNESOTA BY
MONDAY MORNING. DURING THIS TIMEFRAME HIGH PRESSURE WILL BUILD
OVER NORTHERN ONTARIO. AS A RESULT A TIGHT PRESSURE GRADIENT WILL
DEVELOP OVER THE FORECAST AREA...WHICH WILL RESULT IN GUSTY EASTERLY
AND NORTHEASTERLY WINDS. GUSTY CONDITIONS ARE EXPECTED TO PERSIST
THROUGH MONDAY WITH THE HIGHEST GUSTS APPROACHING 40 KTS AT KDLH.
LATEST 00Z GUIDANCE AND HRRR TRENDS SHOW PRECIPITATION MOVE IN THE
VICINITY OF KINL. AS A RESULT...BROUGHT VCSH INTO KINL BETWEEN
11Z-16Z.
EXPECT PRECIPITATION ASSOCIATED WITH THE WARM FRONT FROM THE LOW TO
MOVE IN BETWEEN 18Z AND 01Z...AFFECTING THE KBRD SITE FIRST AND
SPREADING NORTHEASTWARDS TO OTHER TERMINALS. VFR CONDITIONS EXPECTED
AT KHYR AND KINL THROUGH THE FORECAST PERIOD...HOWEVER MVFR CIGS
POSSIBLE AT KHYR AFTER 02Z...BUT NOT CONFIDENT DUE TO DRIER AIR IN
LOWER LEVELS. ALL OTHER TERMINALS WILL SEE MVFR CONDITIONS DEVELOP
BETWEEN 22Z-01Z. KDLH AND KHIB MAY SEE IFR CIGS LATE IN THE
PERIOD...BUT NOT CONFIDENT ON THE TIMING. KBRD WILL SEE IFR CIGS
DEVELOP 01Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 43 38 40 35 / 50 100 70 70
INL 52 36 39 33 / 30 100 90 70
BRD 49 40 49 36 / 50 100 70 60
HYR 57 45 57 35 / 20 90 60 60
ASX 44 37 45 35 / 40 90 70 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ143>147.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM CDT TUESDAY FOR
LSZ121-140>148.
&&
$$
SHORT TERM...JJM
LONG TERM...LE
AVIATION...WL/LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1227 AM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1227 AM CDT SUN MAY 10 2015
UPDATED AVIATION SECTION BELOW.
UPDATE ISSUED AT 1010 PM CDT SAT MAY 9 2015
LOWERED MIN TEMPS ALONG THE NORTH SHORE A FEW DEGREES AS COLDER
AIR FROM LAKE SUPERIOR IS AFFECTING THE AREA. REST OF THE FORECAST
ON TRACK.
UPDATE ISSUED AT 717 PM CDT SAT MAY 9 2015
MADE SOME ADJUSTMENTS TO CLOUD COVER WITH LARGE AREA OF CLEAR SKY
IN NW WI AT 00Z. DELAYED THE ONSET OF THE PCPN UNTIL AFTER 12Z
SUNDAY PER THE LATEST SHORT TERM HRRR AND RAP. REST OF THE
FORECAST ON TRACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 330 PM CDT SAT MAY 9 2015
HIGH PRESSURE OVER SOUTHERN CANADA WILL CONTINUE TO GIVE THE
NORTHLAND DRY NORTH TO NE FLOW THROUGH TONIGHT. A STUBBORN LOW
LEVEL CLOUD DECK OVER NE MINNESOTA WILL SLOWLY SCATTER OUT THROUGH
THE REST OF THE THIS AFTERNOON AND EARLY THIS EVENING. THE CLOUD
DECK HAS BEEN SLOW TO ERODE BECAUSE OF THE LACK OF WIND TO MIX IT
OUT...BUT NW WISCONSIN HAS CLEARED OUT DUE TO STRONGER WINDS
COMING OFF OF LAKE SUPERIOR.
A LOW PRESSURE SYSTEM IN EASTERN COLORADO WILL MOVE INTO THE
CENTRAL PLAINS TONIGHT AND SUNDAY ON TRACK TOWARDS MINNESOTA. THIS
SYSTEM WILL BRING INCREASING MID LEVEL MOISTURE INTO THE UPPER
MIDWEST AND EVENTUALLY RAINS. IT WILL TAKE SOME TIME FOR THE LOW
LEVELS DUE TO THE THE RELATIVELY DRY FLOW FROM CANADA...SO THIS
MEANS IT WILL TAKE SOME TIME FOR THE RAINS TO MOVE INTO THE
REGION. THE GFS/NAM/SREF/GEM/ECMWF MODELS DRASTICALLY DELAYED THE
TIMING WITH WHICH THE PCPN MOVES INTO THE NORTHLAND...SO REFLECTED
THIS IN THE LATEST FORECAST.
SUNDAY IS MAINLY EXPECTED TO BE A COOL AND WINDY DAY. THERE WILL
BE INCREASING ENE WINDS WITH THE STRONGEST WINDS DOWNWIND OF LAKE
SUPERIOR...WHERE GUSTS OF 25 TO 35 MPH ARE POSSIBLE. TEMPERATURES
WILL ONLY REACH THE LOWER 40S NEAR LAKE SUPERIOR...BUT MORE INLAND
AREAS SHOULD REACH THE 50S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 PM CDT SAT MAY 9 2015
FOCUS IN EXTENDED ON THE COOL TEMPERATURES AND SNOW CHANCES AS A
CUT OFF LOW TRACKS OUT OF THE DAKOTAS SUNDAY NIGHT...AND MIGRATES
SLOWLY ACROSS MINNESOTA/WESTERN LAKE SUPERIOR MONDAY/MONDAY
NIGHT.
THE LOW WILL BRING A PROLONGED PERIODS OF RAIN...AND ISOLATED
THUNDER. HAVE CONTINUED TO CARRY HIGH/DEFINITE POPS SUNDAY NIGHT
THROUGH MONDAY NIGHT. AT THIS TIME...THE HEAVIEST RAINFALL IS
EXPECTED ACROSS THE IRON RANGE/ARROWHEAD REGION OF NORTHEAST
MN...WITH TOTALS THROUGH TUESDAY OF AROUND INCH.
MODELS ARE IN GOOD AGREEMENT THAT BELOW ZERO H85 TEMPS WRAP
AROUND THE BACK SIDE OF THE LOW MONDAY...SPREADING OVER THE
NORTHLAND MONDAY NIGHT AND TUESDAY. THIS WILL BRING A CHANCE OF
SNOW OR A RAIN/SNOW MIX FOR THE MONDAY NIGHT AND TUESDAY PERIODS.
LATEST NAM/GFS BUFR SOUNDINGS AT KELO AND KHIB SHOW DEEPLY
SATURATED LOW AND MID LEVELS...PWATS AROUND 3/4 OF AN INCH...AND
TEMP PROFILES JUST ABOVE THE SFC REMAINING WELL BELOW THE ZERO
ISOTHERM. ALTHOUGH A PERIOD OF SNOW IS EXPECTED...AND SOME
ACCUMULATION WILL BE POSSIBLE IN THE MN ARROWHEAD/SOUTH SHORE
REGION...MOST LOCATIONS CAN EXPECT THE SNOW TO MELT AS IT REACHES
THE GROUND WITH ONLY ACCUMULATION ON ELEVATED SURFACES.
HAVE INCREASED POPS TUESDAY ABOVE THE SUPERBLEND GUIDANCE AS
STEEP LAPSE RATES...AROUND 100 J/KG OF CAPE...AND WRAP AROUND
MOISTURE WILL SUPPORT A TYPICAL POST-LOW DAY OF INSTABILITY
SHOWERS. THE SHOWERS WILL LIKELY MIX WITH SNOW DURING THE MORNING
HOURS...CHANGING TO ALL RAIN IN THE AFTERNOON...WITH LIGHT QPF ON
THE ORDER OF A FEW HUNDREDTHS. THE EXCEPTION IS ALONG THE GOGEBIC
RANGE IN NRN WISCONSIN WHERE TEMPERATURES WILL BE COOLER AND THE
RAIN/SNOW MIX MAY PERSIST THROUGH THE EVENING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1227 AM CDT SUN MAY 10 2015
AN AREA OF LOW PRESSURE WILL TRACK NORTHEASTWARDS TONIGHT FROM
EASTERN COLORADO THROUGH NEBRASKA...AND INTO SOUTHWEST MINNESOTA BY
MONDAY MORNING. DURING THIS TIMEFRAME HIGH PRESSURE WILL BUILD
OVER NORTHERN ONTARIO. AS A RESULT A TIGHT PRESSURE GRADIENT WILL
DEVELOP OVER THE FORECAST AREA...WHICH WILL RESULT IN GUSTY EASTERLY
AND NORTHEASTERLY WINDS. GUSTY CONDITIONS ARE EXPECTED TO PERSIST
THROUGH MONDAY WITH THE HIGHEST GUSTS APPROACHING 40 KTS AT KDLH.
LATEST 00Z GUIDANCE AND HRRR TRENDS SHOW PRECIPITATION MOVE IN THE
VICINITY OF KINL. AS A RESULT...BROUGHT VCSH INTO KINL BETWEEN
11Z-16Z.
EXPECT PRECIPITATION ASSOCIATED WITH THE WARM FRONT FROM THE LOW TO
MOVE IN BETWEEN 18Z AND 01Z...AFFECTING THE KBRD SITE FIRST AND
SPREADING NORTHEASTWARDS TO OTHER TERMINALS. VFR CONDITIONS EXPECTED
AT KHYR AND KINL THROUGH THE FORECAST PERIOD...HOWEVER MVFR CIGS
POSSIBLE AT KHYR AFTER 02Z...BUT NOT CONFIDENT DUE TO DRIER AIR IN
LOWER LEVELS. ALL OTHER TERMINALS WILL SEE MVFR CONDITIONS DEVELOP
BETWEEN 22Z-01Z. KDLH AND KHIB MAY SEE IFR CIGS LATE IN THE
PERIOD...BUT NOT CONFIDENT ON THE TIMING. KBRD WILL SEE IFR CIGS
DEVELOP 01Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 38 41 36 47 / 100 80 70 40
INL 37 40 34 50 / 80 90 70 40
BRD 39 49 37 52 / 90 70 60 30
HYR 45 54 35 48 / 90 60 60 50
ASX 40 41 35 43 / 80 70 60 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...GALE WARNING FROM 10 AM THIS MORNING TO 7 PM CDT MONDAY FOR
LSZ121-140>148.
&&
$$
UPDATE...LE/GSF/GSF
SHORT TERM...GROCHOCINSKI
LONG TERM...GRANING
AVIATION...WL/LE
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
433 PM CDT Sun May 10 2015
.SHORT TERM: (Through Late Tonight)
Issued at 431 PM CDT Sun May 10 2015
Have heavily leaned towards the afternoon runs of the HRRR for
convective trends heading into the early evening hours. N-S band of
convection is plowing east at 40-45 kts, and will likely be exiting
eastern sections of our CWA shortly after 00z. After an early
evening lull in activity convection should then return to the
CWA...with threat likely a combination of the activity now
increasing along cold front over eastern KS as well as convection
redeveloping just north of Red River.
Believe that this SE OK activity will be the dominate convection
for our area overnight, as current activity will be intensifying
the low level boundary draped across the ARKLATEX, with this dome
of rain-cooled air providing lift to increasing low level jet that
will be transporting very moist air into the region from the
southern Plains. This area will also be in a favorable area of
upper level divergence tied to RRQ of upper level jet.
Once current line of convection exits area, uncertain about
additional severe weather potential overnight. Current activity
as well as latest upstream convection will be putting a big bite
in the instability that will be available, although large scale
shear of 30-50kts still certainly suggests some severe weather
potential. In addition...while some decent rainfalls are likely
over southern sections of the CWA, believe the aforementioned
outflow boundary will keep the heaviest rain threat anchored over
AR...and south of our CWA.
Truett
.LONG TERM: (Monday through Next Sunday)
Issued at 431 PM CDT Sun May 10 2015
Convection should press east and exit the region during the day
on Monday as cold front pushes across the CWA. I`ve held onto much
higher PoPs than guidance for the early part of the morning on the
western edge of the expected precip shield (generally from near
Cuba thru STL to near Carlinville), but then quickly wind them
down to the SE of STL during the late morning and early afternoon
hours. Any severe weather potential will be strongly tied to
morning convection trends, but SWODY2 still looks reasonable that
greatest threat will be in our far southeast counties, where the
AMS will stand at least some chance of destabililzing before fropa
occurs.
As unseasonably strong upper level low spins its way across the
Great Lakes Monday night and Tuesday, it will drag much cooler air
into the area. This should result in a dry Tuesday with temps a
bit below average, as highs will primarily be in the 60s. Ridging
in the wake of the departing low will mean more tranquil weather
by midweek, with temperatures moderating into the 70s.
Another upper level system will mean a return of unsettled weather
heading into the latter half of the week. There is a large
discrepency in the medium range solutions regarding the location and
movement of this feature especially heading into next weekend, but
with all solutions suggesting a frontal boundary remaining over
the area forecast will mention a chance of thunderstorms in most
areas during the Thursday-Sunday time frame.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1222 PM CDT Sun May 10 2015
Line of thunderstorms will reach KCOU by around 20Z, then KSTL by
22Z. Expect thunder threat to last about 2 hours, but limited
instability will preclude widespread threat of any severe weather. Latest
model runs continue to show an area of rain, with little to no
thunder expected, will form overnight and move through the TAF
sites until around 12Z. Ceilings may drop to 2000 feet as rain
ends early Monday morning. Ceilings will then improve as drier
air moves in and winds back to westerly by late Monday morning.
Specifics for KSTL: VFR conditions until around 22Z when an line
of thunderstorms will move through KSTL. Thunder threat will last
about 2 hours, then an area of rain will move in overnight. No
appreciable instability with this area of rain, so thunder threat
is small. Rain will likely end by around 12Z Monday. Ceilings may
drop to around 2000 feet as the rain ends, however winds will
continue to back, bringing in a drier airmass which will help
ceilings lift and scatter out by 18Z Monday.
Browning
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 66 74 52 69 / 80 80 5 0
Quincy 61 68 46 65 / 70 30 5 0
Columbia 57 69 47 68 / 70 20 5 0
Jefferson City 58 71 47 69 / 70 20 5 0
Salem 68 76 53 68 / 90 80 10 0
Farmington 63 75 50 69 / 80 80 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1237 PM CDT Sun May 10 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 355 AM CDT Sun May 10 2015
Warm front just north of the I-70 corridor will continue advancing
slowly northward this morning and should be well north of the
forecast area into Iowa and northern Illinois by 17-18Z. Deep
moisture combined with another passing MCV and low level warm
advection will continue to produce scattered showers and the
occasional thunderstorm this morning. The primary shortwave over
northeast Colorado is finally moving, opening up, and being drawn up
into the mean flow. Should see the surface low associated with the
wave tighten up and move from western Kansas into northeast Nebraska
or northwest Iowa by early evening. Short range guidance suggests
there will be another wave of rain and thunderstorms this afternoon
well ahead of the cold front, probably triggered by another MCV
generated by the convection now occurring over central Texas. NAM
and RAP produce 2000-2700 J/Kg of CAPE this afternoon in the warm
sector across the area for this MCV to work with. Add in 40+ kts of
0-6km shear and severe thunderstorms look more likely today than the
past couple of days. Not sure what the mode of thunderstorm
development will ultimately be, but would a few discrete rotating
storms will be possible before everything congeals into clusters or
broken lines.
Carney
.LONG TERM: (Tonight through Saturday)
Issued at 355 AM CDT Sun May 10 2015
Southwest flow aloft will persist for much of this period, only
ending when the main TROF ejects thru our region. Thrown into the
mix will be a general southerly flow at the surface, well above
normal levels of moisture thru the column for early May, and a
series of upper level disturbances ejecting from a wound up storm
system currently over the central High Plains. This will yield high
PoPs thru Monday.
Severe storm potential still on track today and tonight, with the
best timeframe from mid-afternoon into mid-evening as better bulk
shear enters the fray during this time and there should still be
enough instability to create the conditional risk with a good
synoptic signal to also trigger widespread convection intiation from
the west with this beginning entering our CWA during this time. The
highest risk locations in our CWA will be to the west of STL
metro--in northeast and central MO. Outside of these locations and
times, this does not necessarily preclude severe wx occurrence.
Monday continues to look marginal on severe for our area, with the
highest risk locations being where the surface cold front will be as
things start to heat up for the day and this should be just east of
STL metro. The best timeframe for our CWA is a bit more sped
up--late morning and early afternoon--and this accounts for SPC`s
push of the main severe threat further east.
A localized heavy rainfall threat also continues thru Monday in this
favorable synoptic pattern, and indeed, localized heavy rainfall has
already occurred in spots scattered across our CWA, with these spots
rather small in coverage and between 2-3" over a 3-day period. No
FFA issuance with this package but the beginnings of a clearer
signal and focus are coming into play tonight and Monday morning to
perhaps justify one eventually but would like to see a bit more
favorable antecedent conditions (i.e. more rainfall today) before
this occurs as current QPF not enough to make up for this.
Preferred the higher MOS temps on Monday with SW flow and what
should be afternoon clearing, but if the rain and thicker clouds are
slower to exit, will need to chop the temps down by about 5 degrees.
For Tuesday and Wednesday, we will see NW flow initially transition
to a building RIDGE overhead from the southeast CONUS. The much
drier column and lack of upper level disturbances or surface fronts
will give us a rare two-day dry period. Temps should actually be a
bit below average with cool nighttime mins in the 40s.
The RIDGE aloft on Thursday will then gradually transition back to
an active SW flow aloft pattern for next weekend. While there
remain model discrepancies during this period, it looks to be one
where at least Climo PoPs [25-30%] are justified and more with
general agreement on moisture return and lifting mechanisms. Temps
will make a return back to average or even above average during this
time.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1222 PM CDT Sun May 10 2015
Line of thunderstorms will reach KCOU by around 20Z, then KSTL by
22Z. Expect thunder threat to last about 2 hours, but limited
instability will preclude widespread threat of any severe weather. Latest
model runs continue to show an area of rain, with little to no
thunder expected, will form overnight and move through the TAF
sites until around 12Z. Ceilings may drop to 2000 feet as rain
ends early Monday morning. Ceilings will then improve as drier
air moves in and winds back to westerly by late Monday morning.
Specifics for KSTL: VFR conditions until around 22Z when an line
of thunderstorms will move through KSTL. Thunder threat will last
about 2 hours, then an area of rain will move in overnight. No
appreciable instability with this area of rain, so thunder threat
is small. Rain will likely end by around 12Z Monday. Ceilings may
drop to around 2000 feet as the rain ends, however winds will
continue to back, bringing in a drier airmass which will help
ceilings lift and scatter out by 18Z Monday.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
714 AM CDT Sun May 10 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 355 AM CDT Sun May 10 2015
Warm front just north of the I-70 corridor will continue advancing
slowly northward this morning and should be well north of the
forecast area into Iowa and northern Illinois by 17-18Z. Deep
moisture combined with another passing MCV and low level warm
advection will continue to produce scattered showers and the
occasional thunderstorm this morning. The primary shortwave over
northeast Colorado is finally moving, opening up, and being drawn up
into the mean flow. Should see the surface low associated with the
wave tighten up and move from western Kansas into northeast Nebraska
or northwest Iowa by early evening. Short range guidance suggests
there will be another wave of rain and thunderstorms this afternoon
well ahead of the cold front, probably triggered by another MCV
generated by the convection now occurring over central Texas. NAM
and RAP produce 2000-2700 J/Kg of CAPE this afternoon in the warm
sector across the area for this MCV to work with. Add in 40+ kts of
0-6km shear and severe thunderstorms look more likely today than the
past couple of days. Not sure what the mode of thunderstorm
development will ultimately be, but would a few discrete rotating
storms will be possible before everything congeals into clusters or
broken lines.
Carney
.LONG TERM: (Tonight through Saturday)
Issued at 355 AM CDT Sun May 10 2015
Southwest flow aloft will persist for much of this period, only
ending when the main TROF ejects thru our region. Thrown into the
mix will be a general southerly flow at the surface, well above
normal levels of moisture thru the column for early May, and a
series of upper level disturbances ejecting from a wound up storm
system currently over the central High Plains. This will yield high
PoPs thru Monday.
Severe storm potential still on track today and tonight, with the
best timeframe from mid-afternoon into mid-evening as better bulk
shear enters the fray during this time and there should still be
enough instability to create the conditional risk with a good
synoptic signal to also trigger widespread convection intiation from
the west with this beginning entering our CWA during this time. The
highest risk locations in our CWA will be to the west of STL
metro--in northeast and central MO. Outside of these locations and
times, this does not necessarily preclude severe wx occurrence.
Monday continues to look marginal on severe for our area, with the
highest risk locations being where the surface cold front will be as
things start to heat up for the day and this should be just east of
STL metro. The best timeframe for our CWA is a bit more sped
up--late morning and early afternoon--and this accounts for SPC`s
push of the main severe threat further east.
A localized heavy rainfall threat also continues thru Monday in this
favorable synoptic pattern, and indeed, localized heavy rainfall has
already occurred in spots scattered across our CWA, with these spots
rather small in coverage and between 2-3" over a 3-day period. No
FFA issuance with this package but the beginnings of a clearer
signal and focus are coming into play tonight and Monday morning to
perhaps justify one eventually but would like to see a bit more
favorable antecedent conditions (i.e. more rainfall today) before
this occurs as current QPF not enough to make up for this.
Preferred the higher MOS temps on Monday with SW flow and what
should be afternoon clearing, but if the rain and thicker clouds are
slower to exit, will need to chop the temps down by about 5 degrees.
For Tuesday and Wednesday, we will see NW flow initially transition
to a building RIDGE overhead from the southeast CONUS. The much
drier column and lack of upper level disturbances or surface fronts
will give us a rare two-day dry period. Temps should actually be a
bit below average with cool nighttime mins in the 40s.
The RIDGE aloft on Thursday will then gradually transition back to
an active SW flow aloft pattern for next weekend. While there
remain model discrepancies during this period, it looks to be one
where at least Climo PoPs [25-30%] are justified and more with
general agreement on moisture return and lifting mechanisms. Temps
will make a return back to average or even above average during this
time.
TES
&&
.AVIATION: (For the 12z TAFs through 12z Monday Morning)
Issued at 644 AM CDT Sun May 10 2015
A warm front is lifting slowly northward across the area. Surface
analysis from 11Z suggests the front was just south of a line from
KMBY to KPPQ, but just north of KIJX and KSPI. Front will continue
moving north this morning as low pressure strengthens and becomes
more organized over the Great Plains. IFR flight conditions will
continue to prevail along and north of the front this morning
across northern Missouri into west central Illinois, with ceilings
and visibilities improving to VFR as the wind shifts to the south
after FROPA. Widely scattered showers will be possible almost any
time today, but more widespread showers and thunderstorms are
likely later this afternoon into the evening as another
disturbance moves across the area. Some of the storms this
afternoon and evening could be strong or severe producing wind
gusts in excess of 50kts and large hail.
Unsure how the rest of the forecast period will play out. Think
the most likely scenario is lingering marginal cigs/vsbys with
periods of showers and thunderstorms continuing tonight. Think the
most likely areas for rain and storms will be along and south of
I-70.
Specifics for KSTL:
Warm front is north of the terminal at this time, so low
ceiling/visibility threat should be much diminished at Lambert for
the time being. Cannot rule out a passing shower just about any
time through early afternoon, but expect there will be far more
dry time than precipitation. Latest short-range guidance suggests
that the best chance for rain/thunderstorms will be mid to late
afternoon (probably after 20Z) as another disturbance moves over
our area from the southwest. There is a chance that the storms
could be severe with wind in excess of 50kts and/or large hail.
Unsure how the rest of the forecast period will play out. Think
the most likely scenario is lingering marginal cigs/vsbys with
periods of showers and thunderstorms continuing tonight. Think the
most likely areas for rain and storms will be along and south of
I-70. The cold front looks to move through the terminal mid to
late Monday morning; this will finally bring an end to the recent
bout of unsettled weather.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
355 AM CDT Sun May 10 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 355 AM CDT Sun May 10 2015
Warm front just north of the I-70 corridor will continue advancing
slowly northward this morning and should be well north of the
forecast area into Iowa and northern Illinois by 17-18Z. Deep
moisture combined with another passing MCV and low level warm
advection will continue to produce scattered showers and the
occasional thunderstorm this morning. The primary shortwave over
northeast Colorado is finally moving, opening up, and being drawn up
into the mean flow. Should see the surface low associated with the
wave tighten up and move from western Kansas into northeast Nebraska
or northwest Iowa by early evening. Short range guidance suggests
there will be another wave of rain and thunderstorms this afternoon
well ahead of the cold front, probably triggered by another MCV
generated by the convection now occurring over central Texas. NAM
and RAP produce 2000-2700 J/Kg of CAPE this afternoon in the warm
sector across the area for this MCV to work with. Add in 40+ kts of
0-6km shear and severe thunderstorms look more likely today than the
past couple of days. Not sure what the mode of thunderstorm
development will ultimately be, but would a few discrete rotating
storms will be possible before everything congeals into clusters or
broken lines.
Carney
.LONG TERM: (Tonight through Saturday)
Issued at 355 AM CDT Sun May 10 2015
Southwest flow aloft will persist for much of this period, only
ending when the main TROF ejects thru our region. Thrown into the
mix will be a general southerly flow at the surface, well above
normal levels of moisture thru the column for early May, and a
series of upper level disturbances ejecting from a wound up storm
system currently over the central High Plains. This will yield high
PoPs thru Monday.
Severe storm potential still on track today and tonight, with the
best timeframe from mid-afternoon into mid-evening as better bulk
shear enters the fray during this time and there should still be
enough instability to create the conditional risk with a good
synoptic signal to also trigger widespread convection intiation from
the west with this beginning entering our CWA during this time. The
highest risk locations in our CWA will be to the west of STL
metro--in northeast and central MO. Outside of these locations and
times, this does not necessarily preclude severe wx occurrence.
Monday continues to look marginal on severe for our area, with the
highest risk locations being where the surface cold front will be as
things start to heat up for the day and this should be just east of
STL metro. The best timeframe for our CWA is a bit more sped
up--late morning and early afternoon--and this accounts for SPC`s
push of the main severe threat further east.
A localized heavy rainfall threat also continues thru Monday in this
favorable synoptic pattern, and indeed, localized heavy rainfall has
already occurred in spots scattered across our CWA, with these spots
rather small in coverage and between 2-3" over a 3-day period. No
FFA issuance with this package but the beginnings of a clearer
signal and focus are coming into play tonight and Monday morning to
perhaps justify one eventually but would like to see a bit more
favorable antecedent conditions (i.e. more rainfall today) before
this occurs as current QPF not enough to make up for this.
Preferred the higher MOS temps on Monday with SW flow and what
should be afternoon clearing, but if the rain and thicker clouds are
slower to exit, will need to chop the temps down by about 5 degrees.
For Tuesday and Wednesday, we will see NW flow initially transition
to a building RIDGE overhead from the southeast CONUS. The much
drier column and lack of upper level disturbances or surface fronts
will give us a rare two-day dry period. Temps should actually be a
bit below average with cool nighttime mins in the 40s.
The RIDGE aloft on Thursday will then gradually transition back to
an active SW flow aloft pattern for next weekend. While there
remain model discrepancies during this period, it looks to be one
where at least Climo PoPs [25-30%] are justified and more with
general agreement on moisture return and lifting mechanisms. Temps
will make a return back to average or even above average during this
time.
TES
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1153 PM CDT Sat May 9 2015
Band of light SHRA will continue moving nwd, but continue to break
up and may not reach UIN, those shud reach STL/SUS/CPS. FG may
develop tonight, but with extensive cloud cover across the region,
do not anticipate anything below MVFR. Expect most of Sun to be
dry with TSRA approaching the region during the late afternoon
into evening hours.
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1212 AM CDT Sun May 10 2015
.SHORT TERM...(This Evening through Sunday)
Issued at 305 PM CDT SAT MAY 9 2015
Thunderstorm chances will increase through this evening and tonight
as a 50-60kt low level jet sets up along the MO/KS border and
overruns the stationary boundary near the I-44 corridor. Large
amounts of more moist air will spread into the region ahead of a
shortwave trough currently over central OK. Short term forecast
progs show K-index values around 40, well over the baseline of 30
generally needed for heavy rainfall. We`re also seeing tall and
skinny CAPE on RUC forecast soundings. With fairly saturated soils
from previous two nights of rainfall, will be issuing a Flash
Flood Watch for areas along and west of an Osceola to Cassville to
Gainesville line through 1 AM Monday. Later shifts may need to
modify areal coverage and timing.
Severe storm threat will remain on the lower end for hail and
straight line winds, but not zero. Better instability and more
favorable vertical wind shear for rotating storms will remain to our
west, in closer proximity to the main upper low pressure system over
the four corners region.
With better instability and upper level dynamics ahead of the
upper low which finally ejects to the northeast into the central Plains,
severe threat will be higher on Sunday afternoon/evening.
.LONG TERM...(Sunday Night through Saturday)
Issued at 305 PM CDT SAT MAY 9 2015
As the upper low continues to shift northward into the upper
Midwest, a cold front will finally push east of the region Monday
morning and bring a much drier and slightly cooler air mass into
the MO Ozarks/SE KS. We may see a few lingering showers over our
far eastern counties, so will keep storms in the forecast east of a
Warsaw to Cassville line through the morning, and east of a Rolla
to Gainesville line through the afternoon.
Surface high pressure will remain over the region through
Wednesday before another lee side trough sets up over the southern
Rockies ahead of an upper low moving into the southern CA coast
late next week. So expect increasingly stormy conditions from late
next week into the weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1203 AM CDT SUN MAY 10 2015
For the KSGF/KJLN/KBBG tafs: Periods of showers and tstms will
occur during the taf period. Hard to pinpoint timing but used a
mix of the high resolution models and then increased chances for
precip late in the taf period with the approach of a sfc front.
Expect a period of MVFR/IFR conditions at times with lower ceilings
and/or fog toward 12z and with any heavier showers.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH through late tonight FOR MOZ066-067-077-078-
088-089-093>095-101>105.
KS...FLASH FLOOD WATCH through late tonight FOR KSZ073-097-101.
&&
$$
SHORT TERM...Terry
LONG TERM...Terry
AVIATION...DSA
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
908 PM MDT MON MAY 11 2015
.DISCUSSION... UPDATE FORTHCOMING. SOUTHWEST FLOW ALOFT CONTINUES TO
BRING MOISTURE AND INSTABILITY TO SOUTHWEST MONTANA WHERE SCATTERED
SHOWERS SHOULD CONTINUE THROUGH THE NIGHT. BOTH THE HRRR AND RUC
ANALYSIS BRING SHOWERS AS FAR NORTH AS JUST ABOUT GREAT FALLS BY
12Z. TEMPERATURES OVERNIGHT LOOK ON TRACK.
&&
.AVIATION...
UPDATED 0020Z.
INCREASING SOUTHWEST FLOW ALOFT CONTINUES TO BRING
MOISTURE AND INSTABILITY TO THE AREA. SCATTERED SHOWERS WILL PERSIST
OVERNIGHT OVER SOUTHWEST MONTANA WITH DRY CONDITIONS ELSEWHERE.
SHOWERS AND ISOLATED THUNDERSTORMS WILL SPREAD SLOWLY NORTH AND EAST
AFTER 18Z. VFR CONDITIONS PREVAIL WITH MVFR CONDITIONS IN THE
VICINITY OF SHOWERS AND THUNDERSTORMS ALONG WITH ERRATIC GUSTY WINDS.
&&
.PREV DISCUSSION...ISSUED 259 PM MDT MON MAY 11 2015
MONDAY THROUGH WEDNESDAY...CONDITIONS WILL GENERALLY CHANGE TO A
WETTER PATTERN THROUGH THE MIDDLE OF THE WEEK AS SHORTWAVE TROUGHS
MOVE ONSHORE AND BEGIN TO BRING MOISTURE INTO THE REGION. SOME
SHOWERS OVER THE HIGHER TERRAIN WILL BE POSSIBLE THIS EVENING AS
THE FIRST SHORTWAVE MOVES INTO THE AREA. PRECIPITATION WILL BE
LIMITED WITH THIS SYSTEM WITH MOST OF THE SHOWERS OCCURRING OVER
THE ROCKY MOUNTAIN FRONT. THE NEXT SYSTEM WILL BEGIN TO MOVE INTO
MONTANA TUESDAY NIGHT AND SHOULD BRING AN INCREASE IN SHOWERS AND
THUNDERSTORMS TO THE AREA TUESDAY AFTERNOON AND EVENING. THIS
EVENT LOOKS LIKE IT SHOULD BRING MORE WIDESPREAD PRECIPITATION TO
THE AREA AS THE MOVES ACROSS THE STATE WEDNESDAY. PRECIPITATION IS
EXPECTED TO DECREASE WEDNESDAY AFTERNOON AND EVENING. TEMPERATURES
SHOULD COOL OFF TUESDAY AND WEDNESDAY BACK BELOW SEASONAL
AVERAGES. SUK
WEDNESDAY NIGHT THROUGH MONDAY. AT THIS TIME, FORECAST CONFIDENCE
IS LOW FOR MUCH OF THIS PERIOD AS PRIMARY FORECAST MODELS NOT
SHOWING MUCH CONSENSUS, ESPECIALLY ON PRECIPITATION COVERAGE AND
AMOUNTS. THE MODEL DIFFERENCES CENTER ON THE EVOLUTION OF A BROAD
SHORTWAVE TROF THAT WILL BE OFF THE CALIFORNIA COAST ON THURSDAY.
MODELS ARE IN GENERALLY GOOD AGREEMENT THAT THE TROF WILL MAKE
SLOW EASTWARD PROGRESS AND BE CENTERED OVER THE GREAT BASIN/DESERT
SOUTHWEST BY LATE FRIDAY. PLUMES OF MOISTURE STREAMING NORTHWARD
AHEAD OF THE TROF AXIS WILL BRING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS INTO MT BY THURS AFTN CONTINUING THRU FRIDAY, WITH
THE ECMWF MODEL INDICATING MUCH WIDER PRECIP COVERAGE OVER
CENTRAL/SOUTHWEST MT. THINGS GET MORE COMPLICATED OVER THE WEEKEND
AS THE TROF LIFTS NORTHEASTWARD TOWARD THE CENTRAL ROCKIES. BOTH
THE GFS AND EC MODELS SHIFT OUR WINDS ALOFT TO EASTERLY AS THE
TROF PASSES TO OUR SOUTH, SETTING UP THE POSSIBILITY OF PULLING
EXTENSIVE GULF OF MEXICO MOISTURE THROUGH THE UPPER MIDWEST AND
INTO THE TREASURE STATE ON BOTH SAT/SUN. THE EC IS NOTABLY
STRONGER WITH THIS LONG MOISTURE FETCH, DRIVEN MAINLY BY A CLOSED
MID-LEVEL LOW PRESSURE AREA WITHIN THE TROF, WHEREAS THE GFS
INDICATES AN OVERALL WEAKER TROF WITH LESS MOISTURE OVER OUR
REGION. IN FACT, THE GFS HAS MUCH OF THE TROF AND PRECIPITATION
OUT OF OUR AREA BY SUNDAY MORNING WHILE THE EC PAINTS EXTENSIVE
RAINFALL WITH AMOUNTS RANGING FROM 0.1 INCH ALONG THE HI-LINE TO
0.5-0.75 INCH FROM GREAT FALLS SOUTHWARD TO THE IDAHO BORDER.
GIVEN THE TROUBLESOME MODEL DIFFERENCES, THE CURRENT EXTENDED
FORECAST LARGELY RELIES ON CLIMATOLOGICAL PRECIP PROBABILITIES
(MOSTLY 30-40%) FOR SATURDAY AND EARLY SUNDAY, THEN REDUCES RAINFALL
CHANCES SUN EVE INTO MONDAY AS THE TROF HEADS TOWARD THE GREAT LAKES
STATES. THE GOOD NEWS IS THAT IT LOOKS THAT MOST/ALL OF THE FORECAST
AREA SHOULD RECEIVE SOME NEEDED RAINFALL THIS WEEKEND; WE`LL JUST
HAVE TO WAIT FOR ADDITIONAL MODEL OUTPUT TO GET A BETTER ESTIMATE ON
AMOUNTS. AS FOR TEMPERATURES, THEY WILL REMAIN AT OR SLIGHTLY ABOVE
SEASONAL VALUES THROUGH THE LATTER HALF OF THE WEEK, WITH HIGHS IN
THE MID- AND UPPER 60S EACH DAY. WARANAUSKAS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 36 60 41 59 / 10 20 30 60
CTB 30 56 35 51 / 10 10 20 70
HLN 40 61 41 65 / 30 30 40 50
BZN 38 60 38 66 / 20 20 50 40
WEY 30 62 31 61 / 30 40 40 30
DLN 41 62 41 67 / 20 40 50 40
HVR 33 63 36 59 / 10 10 20 60
LWT 37 59 39 63 / 20 20 30 50
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
847 PM MDT MON MAY 11 2015
.UPDATE...
ENERGY MOVING THROUGH IDAHO PUSHING MOISTURE INTO SOUTHWEST
MONTANA BUT DOWNSTREAM SHORTWAVE RIDGING IS INFLUENCING THE
WEATHER OVER SOUTH CENTRAL MONTANA. RAP IS CONSISTENTLY KEEPING
THE MOISTURE ON THE WEST SIDE OF THIS SHORTWAVE RIDGE AXIS
OVERNIGHT. HAVE SCALED BACK CHANCES OF PRECIPITATION WESTWARD FOR
THE OVERNIGHT PERIOD. BORSUM
&&
.SHORT TERM...VALID FOR TUE AND WED...
AFTER A NICE START TO THE WORK WEEK TODAY...WE ARE ANTICIPATING A
TRANSITION TO A MUCH MORE UNSETTLED PATTERN THE REST OF THE WEEK.
INVERTED SURFACE TROUGH FROM THE WEST ASSOCIATED WITH AN UPPER
MINI CUT LOW OVER THE OREGON COAST WILL MEAN AN INCREASING CHANCE
OF SHOWERS OVER THE MOUNTAINS THIS EVENING...SPREADING EAST
OVERNIGHT. THAT UPPER CUT OFF LOW TRACKS INLAND TUESDAY RESULTING
IN DIFFLUENT FLOW OVER OUR REGION WITH A GOOD SOURCE OF PACIFIC
MOISTURE INTO OUR FORECAST AREA AS WELL. SO BUMPED UP POPS IN OUR
WEST MOUNTAINS. ENERGY TRACKS NORTH INTO CANADA BY TUESDAY NIGHT
WITH A BRIEF DRYING TREND IN ITS WAKE. HOWEVER...AS MORE ENERGY
DROPS INTO THE TROUGH ON THE WEST COAST WE WILL SEE SW FLOW ALOFT
BRING SCATTERED PRECIPITATION INTO OUR REGION THROUGH WEDNESDAY
NIGHT. MODELS ARE SIMILAR WITH THE OVERALL PATTERN...BUT TEND TO
HAVE SOME CONVECTIVE FEEDBACK AND DETAILS THAT MESS WITH QPF
FIELDS. BASICALLY USED A SMOOTHED OUT BLEND OF PROGGS FOR THE
POPS.
LOOK FOR SLIGHTLY COOLER AFTERNOON HIGHS TUESDAY...FOLLOWED BY
MILD SEASONAL TEMPS FOR WEDNESDAY. BT
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
MODELS...ANALOGS AND ENSEMBLES WERE LENDING INCREASING CONFIDENCE
TO A PROGRESSIVELY UNSETTLED PATTERN INTO NEXT WEEKEND. AN UPPER
LOW OFF THE CA COAST ON THU WILL MOVE INLAND ON FRI. WEAK
ENERGY...WARM ADVECTION AND MOISTURE WILL MOVE N THROUGH THE AREA
ON THU BRINGING A SLIGHT CHANCE OF SHOWERS THROUGH THU NIGHT...WITH
A FEW AFTERNOON AND EVENING THUNDERSTORMS. CHANCES FOR
THUNDERSTORMS LOOKED HIGHER ON FRI AS THE UPPER LOW MOVES INTO WY
BRINGING MORE DYNAMICS AND UNSTABLE AIR. THESE FACTORS WILL
COMBINE WITH AREAS OF HIGHER BULK SHEAR TO PRODUCE A FEW STRONG
THUNDERSTORMS. TEMPERATURES WILL BE SEASONABLE BOTH DAYS.
THE UPPER LOW WILL PROGRESS ENE THROUGH THE REGION ON SAT AND
REACH THE DAKOTAS ON SUN. WRAP-AROUND MOISTURE WILL AFFECT THE
REGION THROUGH SUN AND THE MODELS AGREED ON POTENTIAL HEAVY
RAINFALL FOR THE AREA BEGINNING FRI NIGHT. COLDER AIR GETS PULLED
INTO THE REGION FROM THE N ON SUN THROUGH EARLY MON. RAISED POPS
FURTHER FOR FRI NIGHT INTO SUN. SOME SNOW COULD MIX WITH THE RAIN
OVER SE MT SUN NIGHT INTO MON. MODELS HAD THE PRECIPITATION
TAPERING OFF SUN NIGHT. HIGHS WILL BE IN THE 50S ON THE WEEKEND
WITH THE POTENTIAL TO BE LOWER DUE TO THE PRECIPITATION. ARTHUR
&&
.AVIATION...
SHOWERS WILL INCREASE OVERNIGHT AND TUESDAY MORNING AS A WAVE OF
ENERGY ALOFT CROSSES THE REGION. CONFIDENCE IN SHOWERS AND MVFR-
TYPE CEILINGS IS GREATEST IN THE KLVM AREA IN CLOSE PROXIMITY TO
THE WAVE. THE 00 UTC TAFS ONLY ADVERTISED VCSH AT KBIL AND KMLS
DUE TO LOW CONFIDENCE IN MORE THAN BRIEF...VERY LIGHT SHOWERS AT
THOSE TERMINALS GIVEN AN INITIALLY-DRY NEAR-SURFACE LAYER. AREAS
OF MOUNTAIN OBSCURATION ARE ALSO EXPECTED THROUGH TUESDAY. SCHULTZ
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 041/061 043/068 044/063 046/065 047/057 044/052 040/058
24/T 33/T 32/W 34/T 56/W 65/W 42/W
LVM 036/059 038/066 038/063 041/064 042/056 042/054 036/058
45/T 53/T 33/T 34/T 56/W 65/W 42/W
HDN 038/066 041/071 043/066 045/068 047/060 044/053 038/061
14/T 32/T 32/W 24/T 56/W 65/W 42/W
MLS 038/064 041/067 043/062 045/069 049/062 044/053 039/059
12/W 31/E 23/W 24/T 56/W 65/W 52/W
4BQ 034/063 037/066 044/063 046/068 049/060 045/049 037/056
03/W 21/E 32/W 24/T 55/W 55/W 53/W
BHK 032/058 036/060 040/058 043/065 046/060 044/053 034/056
01/E 22/W 43/W 24/T 55/W 55/W 53/W
SHR 033/064 038/068 040/065 043/067 044/058 041/050 035/056
12/T 32/T 32/T 34/T 45/W 56/W 63/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
615 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 350 AM CDT SUN MAY 10 2015
...LOCATION OF SEVERE STORMS TODAY IS THE MAIN CHALLENGE...
EXCEPTIONALLY ACTIVE/DYNAMIC PATTERN CONTINUES OVER THE CENTRAL
UNITED STATES TODAY AS LARGE UPPER LOW SPINS OVER THE HIGH PLAINS.
WATER VAPOR IMAGERY SHOWED THE CLOSED AND WRAPPED UP CIRCULATION
DRIFTING NORTHEAST AROUND 30 KNOTS...OUT OF NORTHEAST COLORADO
AND HEADED FOR NORTHWEST NEBRASKA THIS MORNING.
A COMPLEX AND HIGHLY BAROCLINIC SURFACE PATTERN WAS ANALYZED AT
06Z WITH A CLOSED 1004MB LOW NEAR THE KANSAS-COLORADO BORDER AND A
TIGHT THERMAL AND PRESSURE GRADIENT NORTH OF THE LOW. WARM FRONT
EXTENDED FROM THE LOW EASTWARD WITH LOW TO MID 60S DEW POINTS OVER
KANSAS...AND AN INVERTED TROF EXTENDED NORTHEAST INTO THE SIOUX
CITY AREA. AIRMASS NORTH OF THE LOW WAS COLD ENOUGH FOR WIDESPREAD
SNOW IN THE WESTERN HIGH PLAINS THIS MORNING.
AS THIS PATTERN EVOLVES THROUGHOUT THE DAY...THE FEATURES BY MID-
LATE AFTERNOON APPEAR TO BE SETTING UP FOR A NEARLY CLASSIC
LOOKING COLD CORE SUPERCELL OUTBREAK. UNFORTUNATELY THERE ARE
SMALL BUT IMPORTANT DIFFERENCES IN THE SUITE OF MODEL SOLUTIONS
REGARDING WHERE THE UPPER AND SURFACE LOWS WILL TRACK...AND THESE
DIFFERENCES COULD RESULT IN THE LOCATION OF THE SUPERCELLS VARYING
BY SEVERAL COUNTIES DEPENDING ON THE SOLUTION.
THE CONSENSUS SOLUTION OF THE SREF MEAN FOR THE PLACEMENT/TRACK
OF THE UPPER AND SURFACE LOWS IS SIMILAR TO THE GOING FORECAST AS
WELL AS CURRENT TRAJECTORIES OF THE UPPER LOW. USING THE SREF MEAN
SOLUTION...THE FORECAST PATTERN IN THE 18-21Z TIME FRAME INCLUDES
THE FOLLOWING INGREDIENTS TO SUPPORT SUPERCELLS OVER NORTHEAST
NEBRASKA AND WEST CENTRAL IOWA: UPPER LOW OVER WESTERN NEBRASKA
WITH 500 MB TEMPERATURES AROUND -19C... TRIPLE POINT AND DEEP
SURFACE LOW NEAR O`NEILL...100+ KNOT UPPER LEVEL JET OVER EASTERN
NEBRASKA...WELL PRONOUNCED DRY SLOT OVER EASTERN NEBRASKA WHICH
WILL SUPPORT ML CAPE VALUES EXCEEDING 1200 J/KG AND A DIFFERENTIAL
THERMAL BOUNDARY ON THE EASTERN EDGE OF THE DRY SLOT... AND 0-1KM
SHEAR VALUES AT OR ABOVE 20 KNOTS.
HOWEVER...NUMEROUS FACTORS INCREASE THE UNCERTAINTY IN THESE
SCENARIOS INCLUDING THE ABOVE MENTIONED SPREAD IN MODEL SOLUTIONS.
IF THE MODELS DISPLAYING A NORTHERN TREND ARE CORRECT...MUCH OF
THE FORECAST AREA WOULD BE DRY AND SUNNY UNDER THE DRY SLOT WITH
THE STRONG STORM DEVELOPMENT NORTH OF THE AREA. IF THE SOUTHERN
SOLUTIONS ARE CORRECT...THE STORMS COULD DEVELOP AS FAR SOUTH AS
INTERSTATE 80 AND TRACK NORTH THROUGHOUT THE AFTERNOON. THE
FORECAST PROBABILITY OF STORMS WILL BE A FUNCTION OF THE
DISTRIBUTION OF THESE MODEL SOLUTIONS. THE MOST LIKELY AREA FOR
SEVERE STORMS WILL BE THE FAR NORTHEAST CORNER OF NEBRASKA AND
WEST CENTRAL IOWA...WITH A CHANCE FOR SEVERE STORMS EXTENDING
SOUTH TO INTERSTATE 80.
LATEST OPERATIONAL HRRR SOLUTIONS SUPPORT THUNDERSTORM
DEVELOPMENT BY EARLY AFTERNOON AND JUST EAST OF THE MISSOURI
RIVER.
THE STORMS AND SHOWERS SHOULD EXIT THE FORECAST AREA BY EVENING.
LOW AMPLITUDE UPPER RIDGING AND SURFACE HIGH PRESSURE BUILDS INTO
THE PLAINS MONDAY-TUESDAY WITH COOL BUT DRY WEATHER EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 10 2015
THE UPPER PATTERN RETURNS TO BROAD SCALE TROFFING OVER THE WESTERN
US AND PACIFIC COASTAL AREAS WITH SHORTWAVES ONCE AGAIN RETURNING
TO THE PLAINS. AFTER THE DRY BEGINNING OF THE WEEK...GOOD CHANCES
FOR RAIN AND THUNDERSTORMS RETURN FOR THE PERIOD BEGINNING
WEDNESDAY NIGHT AND PERSISTING INTO THE WEEKEND.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 613 AM CDT SUN MAY 10 2015
IFR/MVFR CEILINGS EARLY THIS MORNING...WHICH SHOULD SCATTER OUT BY
16 TO 18Z. SOUTHEAST WINDS AROUND 12 KNOTS...WITH GUSTS DEVELOPING
INTO THE LOWER TO MID 20 KNOT RANGE BY 18Z. THUNDERSTORMS WILL BE
POSSIBLE PRIMARILY AT THE KOMA TAF SITE 19-23Z. WINDS THEN SHIFT
TO THE SOUTH...SOUTHWEST AND EVENTUALLY WEST NORTHWEST AS A COLD
FRONT MOVES ACROSS THE AREA. COULD SEE MVFR CEILINGS AND SPOTTY
SHOWERS DEVELOP AT KOFK BY 11/03Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...NIETFELD
LONG TERM...NIETFELD
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
350 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 350 AM CDT SUN MAY 10 2015
...LOCATION OF SEVERE STORMS TODAY IS THE MAIN CHALLENGE...
EXCEPTIONALLY ACTIVE/DYNAMIC PATTERN CONTINUES OVER THE CENTRAL
UNITED STATES TODAY AS LARGE UPPER LOW SPINS OVER THE HIGH PLAINS.
WATER VAPOR IMAGERY SHOWED THE CLOSED AND WRAPPED UP CIRCULATION
DRIFTING NORTHEAST AROUND 30 KNOTS...OUT OF NORTHEAST COLORADO
AND HEADED FOR NORTHWEST NEBRASKA THIS MORNING.
A COMPLEX AND HIGHLY BAROCLINIC SURFACE PATTERN WAS ANALYZED AT
06Z WITH A CLOSED 1004MB LOW NEAR THE KANSAS-COLORADO BORDER AND A
TIGHT THERMAL AND PRESSURE GRADIENT NORTH OF THE LOW. WARM FRONT
EXTENDED FROM THE LOW EASTWARD WITH LOW TO MID 60S DEW POINTS OVER
KANSAS...AND AN INVERTED TROF EXTENDED NORTHEAST INTO THE SIOUX
CITY AREA. AIRMASS NORTH OF THE LOW WAS COLD ENOUGH FOR WIDESPREAD
SNOW IN THE WESTERN HIGH PLAINS THIS MORNING.
AS THIS PATTERN EVOLVES THROUGHOUT THE DAY...THE FEATURES BY MID-
LATE AFTERNOON APPEAR TO BE SETTING UP FOR A NEARLY CLASSIC
LOOKING COLD CORE SUPERCELL OUTBREAK. UNFORTUNATELY THERE ARE
SMALL BUT IMPORTANT DIFFERENCES IN THE SUITE OF MODEL SOLUTIONS
REGARDING WHERE THE UPPER AND SURFACE LOWS WILL TRACK...AND THESE
DIFFERENCES COULD RESULT IN THE LOCATION OF THE SUPERCELLS VARYING
BY SEVERAL COUNTIES DEPENDING ON THE SOLUTION.
THE CONSENSUS SOLUTION OF THE SREF MEAN FOR THE PLACEMENT/TRACK
OF THE UPPER AND SURFACE LOWS IS SIMILAR TO THE GOING FORECAST AS
WELL AS CURRENT TRAJECTORIES OF THE UPPER LOW. USING THE SREF MEAN
SOLUTION...THE FORECAST PATTERN IN THE 18-21Z TIME FRAME INCLUDES
THE FOLLOWING INGREDIENTS TO SUPPORT SUPERCELLS OVER NORTHEAST
NEBRASKA AND WEST CENTRAL IOWA: UPPER LOW OVER WESTERN NEBRASKA
WITH 500 MB TEMPERATURES AROUND -19C... TRIPLE POINT AND DEEP
SURFACE LOW NEAR O`NEILL...100+ KNOT UPPER LEVEL JET OVER EASTERN
NEBRASKA...WELL PRONOUNCED DRY SLOT OVER EASTERN NEBRASKA WHICH
WILL SUPPORT ML CAPE VALUES EXCEEDING 1200 J/KG AND A DIFFERENTIAL
THERMAL BOUNDARY ON THE EASTERN EDGE OF THE DRY SLOT... AND 0-1KM
SHEAR VALUES AT OR ABOVE 20 KNOTS.
HOWEVER...NUMEROUS FACTORS INCREASE THE UNCERTAINTY IN THESE
SCENARIOS INCLUDING THE ABOVE MENTIONED SPREAD IN MODEL SOLUTIONS.
IF THE MODELS DISPLAYING A NORTHERN TREND ARE CORRECT...MUCH OF
THE FORECAST AREA WOULD BE DRY AND SUNNY UNDER THE DRY SLOT WITH
THE STRONG STORM DEVELOPMENT NORTH OF THE AREA. IF THE SOUTHERN
SOLUTIONS ARE CORRECT...THE STORMS COULD DEVELOP AS FAR SOUTH AS
INTERSTATE 80 AND TRACK NORTH THROUGHOUT THE AFTERNOON. THE
FORECAST PROBABILITY OF STORMS WILL BE A FUNCTION OF THE
DISTRIBUTION OF THESE MODEL SOLUTIONS. THE MOST LIKELY AREA FOR
SEVERE STORMS WILL BE THE FAR NORTHEAST CORNER OF NEBRASKA AND
WEST CENTRAL IOWA...WITH A CHANCE FOR SEVERE STORMS EXTENDING
SOUTH TO INTERSTATE 80.
LATEST OPERATIONAL HRRR SOLUTIONS SUPPORT THUNDERSTORM
DEVELOPMENT BY EARLY AFTERNOON AND JUST EAST OF THE MISSOURI
RIVER.
THE STORMS AND SHOWERS SHOULD EXIT THE FORECAST AREA BY EVENING.
LOW AMPLITUDE UPPER RIDGING AND SURFACE HIGH PRESSURE BUILDS INTO
THE PLAINS MONDAY-TUESDAY WITH COOL BUT DRY WEATHER EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 350 AM CDT SUN MAY 10 2015
THE UPPER PATTERN RETURNS TO BROAD SCALE TROFFING OVER THE WESTERN
US AND PACIFIC COASTAL AREAS WITH SHORTWAVES ONCE AGAIN RETURNING
TO THE PLAINS. AFTER THE DRY BEGINNING OF THE WEEK...GOOD CHANCES
FOR RAIN AND THUNDERSTORMS RETURN FOR THE PERIOD BEGINNING
WEDNESDAY NIGHT AND PERSISTING INTO THE WEEKEND.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1138 PM CDT SAT MAY 9 2015
MVFR CEILINGS WILL OVERTAKE ALL TAF SITES TONIGHT...AND SHOWERS
SHOULD BE INCREASING IN COVERAGE AND SHOULD REACH TAF SITES LATER
TONIGHT AS WELL. WITH LOW CONFIDENCE IN COVERAGE OF THUNDER...HAVE
OPTED TO NOT MENTION AT KOFK AND BRING IN A TEMPO FOR AN HOUR AT
KOMA/KLNK. OVERNIGHT ACTIVITY WILL CLEAR SITES IN THE
MORNING...LEAVING A GAP BETWEEN THAT ACTIVITY AND POTENTIAL
SHOWERS/STORMS THIS AFTERNOON. AFTERNOON SHOWERS/STORMS SHOULD BE
PRETTY ISOLATED TO SCATTERED IN COVERAGE...ESPECIALLY AT KLNK
WHERE CONFIDENCE IN SEEING SHOWERS/STORMS IS LOWEST. HAVE KEPT
JUST A SHORT PERIOD OF VCSH AT ALL SITES UNTIL CONFIDENCE
INCREASES...FOLLOWED BY WINDS VEERING TO WESTERLY AND INCREASING.
MODELS HINT AT LOWER CEILINGS COMING IN BEHIND THE FRONT LATE IN
THE TAF PERIOD...AND HAVE INTRODUCED POTENTIAL AT KOFK/KOMA.
&&
.HYDROLOGY...
ISSUED AT 350 AM CDT SUN MAY 10 2015
FLOODING CONTINUES IN SOUTHEAST NEBRASKA MAINLY ALONG THE BIG BLUE
RIVER. FORTUNATELY THIS AREA IS NOT EXPECTED TO RECEIVE
SIGNIFICANT RAINFALL OVER THE NEXT FEW DAYS...THEREFORE THE RIVER
LEVELS SHOULD CONTINUE TO FALL AS PREDICTED.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...NIETFELD
LONG TERM...NIETFELD
AVIATION...MAYES
HYDROLOGY...NIETFELD
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1132 PM CDT SAT MAY 9 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM CDT SAT MAY 9 2015
TONIGHT AND TOMORROW...FORECASTING CONCERNS CENTER ON
THE SEVERE THREAT THIS EVENING...SNOW THREAT IN THE WEST AND
NORTHWEST OVERNIGHT TONIGHT AND SUNDAY...AS WELL AS THE THREAT FOR
HEAVY RAIN AND POSSIBLE FLASH FLOODING CONCERNS. A VIGOROUS UPPER
LEVEL LOW...CURRENTLY OVER SOUTH CENTRAL COLORADO...WILL MIGRATE
INTO NORTHEASTERN COLORADO THROUGH 12Z SUNDAY...BEFORE LIFTING INTO
NORTHERN NEBRASKA BY 00Z MONDAY. IN ASSOCIATION WITH THIS
FEATURE...STRONG TO POSSIBLY SEVERE THUNDERSTORMS WILL BE POSSIBLE
THIS EVENING...FOLLOWED BY THE THREAT FOR HEAVY RAIN
OVERNIGHT...THEN ACCUMULATING SNOWS IN THE EASTERN PANHANDLE AND
NORTHWESTERN SANDHILLS OVERNIGHT. FIRST FOR THE SEVERE THREAT
TONIGHT...A BULGING DRYLINE WILL PUSH FROM SWRN KS INTO NWRN KS BY
06Z SUNDAY. THUNDERSTORMS WILL INITIATE ALONG THIS FEATURE AND
QUICKLY LIFT NORTH INTO SWRN AND SOUTH CENTRAL NEBRASKA. WITH THE
LOW CLOUDS AND COOL CONDS TODAY...THE SEVERE THREAT CONTINUES TO
DIMINISH ACROSS THE SWRN CWA. WITH THIS KIND OF SETUP...DRYLINE TO
THE SOUTH...WARM FRONT TO THE SOUTH...THIS IS TYPICALLY A GOOD SETUP
FOR LARGE HAIL AND THIS WILL BE THE MAIN HAZARD MENTIONED IN THE
HWO. THEN THERE IS THE THREAT FOR SNOW IN THE PANHANDLE AND
NORTHWESTERN SANDHILLS LATER THIS EVENING. ALREADY AS OF 2 PM THIS
AFTERNOON...LIGHT SNOW WAS BEING REPORTED AT CHADRON...WHICH WAS
EARLIER THAN ANTICIPATED WITH THE CURRENT FORECAST. ALREADY HAVE
INCREASED SNOW ACCUMULATIONS IN THE PINE RIDGE AND NERN
PANHANDLE...TO REFLECT AN EARLIER CHANGEOVER OF SNOW. THESE HIGHER
ACCUMS APPG A FOOT WILL BE INCORPORATED IN THE UPDATE OF THE WINTER
STORM WARNING FOR SHERIDAN COUNTY TO BE ISSUED WITH THE AFTERNOON
PACKAGE. SOUTH AND EAST OF SHERIDAN COUNTY...SNOW IS EXPECTED AS
WELL...HOWEVER A MUCH TIGHTER ENVELOPE FOR ACCUMS EXISTS GIVEN
INCREASED MOISTURE AND WARMER TEMPS EXPECTED OVERNIGHT. NO
DOUBT...THE RAIN/SNOW LINE WILL BE VERY TIGHT AND AS IT STANDS RIGHT
NOW...THIS FEATURE RUNS RIGHT THROUGH SHERIDAN COUNTY. TURNING TO
THE HEAVY RAIN THREAT TONIGHT...STRONG MOISTURE ADVECTION CONTINUES
FROM THE SOUTHERN PLAINS INTO NEBRASKA PER 300K MOISTURE TRANSPORT
VECTORS. PW/S WILL INCREASE BY MID EVENING TO 1.1 INCHES AT NORTH
PLATTE...WHICH IS NEAR RECORD FOR THIS TIME OF YEAR. THIS MOISTURE
WILL SHIFT QUICKLY NORTH OVERNIGHT AS THE UPPER LEVEL LOW PUSHES
INTO NORTHEASTERN COLORADO...HOWEVER PW/S WILL STILL BE A HALF TO
2/3RDS OF AN INCH EVEN BEHIND THE DEEPEST AREA OF MOISTURE WHICH
SHIFTS INTO EASTERN NEBRASKA AND SERN SOUTH DAKOTA BY SUNDAY
MORNING. WIDESPREAD PRECIPITATION IS EXPECTED OVERNIGHT...WITH THE
MOST PERSISTENT AREAS TRANSITIONING FROM THE PANHANDLE INTO SWRN AND
CENTRAL NEBRASKA BY LATE EVENING. THIS IS IN RESPONSE TO EXPECTED
CONVECTIVE DEVELOPMENT OVER NORTHWESTERN KS. THE LATEST HRRR AND THE
NAM SOLN FROM THIS MORNING TO A LESSER DEGREE...FOLLOW THIS TREND OF
HEAVIER RAIN SHIFTING INTO SWRN AND CENTRAL NEBRASKA LATER THIS
EVENING...WITH DECREASED QPF IN THE WEST. THIS LULL WILL BE
TEMPORARY HOWEVER. LOOK FOR PCPN TO INCREASE SUNDAY MORNING IN THE
WEST AS DEFORMATION PCPN DEVELOPS ON THE BACK SIDE OF THE EXITING
LOW. THE LATEST 3 HR FLASH FLOOD GUIDANCE IS LESS THAN 1.5 INCHES IN
THE SERN PANHANDLE...KEITH AND PERKINS COUNTIES. THIS AREA HAS
LARGELY ESCAPED THE HEAVY RAIN EARLIER THIS MORNING AND THIS
AFTERNOON. WITH THE HRRR INDICATING HEAVIER RAIN EAST OF THESE
AREAS...WILL FORGO ISSUANCE OF A FLASH FLOOD WATCH FOR THESE AREAS.
FURTHER EAST...3 HR FFG IS AROUND 2 INCHES FOR CUSTER COUNTY SOUTH
OF THE SANDHILLS. AGAIN HRRR QPF/S ARE AROUND 1 TO 2 INCHES IN
CUSTER COUNTY TONIGHT...WHICH IS BELOW FFG SO WILL FORGO A FLASH
FLOOD WATCH.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CDT SAT MAY 9 2015
MODELS VARY SOME WITH AMOUNT OF COLD AIR MOVING THROUGH NORTHERN
NEBRASKA SUNDAY NIGHT AND HAVE GONE WITH COLDER SOLUTION OF THE
NAM. DEFORMATION ZONE WILL CONTINUE TO LIFT THROUGH THE NORTHERN
NEBRASKA SANDHILLS WITH A MIX OF RAIN...RAIN SNOW MIX AND SNOW.
HAVE A COUPLE OF INCHES OF ACCUMULATION WITH THE LIFT ASSOCIATED
WITH THE DEFORMATION ZONE...OVER A VERY SMALL PORTION OF NORTHERN
CHERRY COUNTY. WINDS WILL STAY UP THROUGH MONDAY WITH PRECIP
ENDING THROUGH THE MORNING. LOW TEMPERATURES IN THE 20S NORTHWEST
TO THE MID 30S NORTH CENTRAL...ONEILL. HIGHS IN THE 40S WEST AND
THE 50S SOUTHWEST AND EAST. CLEARING SKIES THROUGH THE DAY WITH
MOSTLY CLEAR SKIES OVER NIGHT. WINDS FALLING OFF AND BECOMING
SOUTH OVER NIGHT WILL ALLOW TEMPERATURES TO FALL TO AROUND
FREEZING. HAVE HELD OFF ON HIGHLIGHTS FOR NOW WITH CURRENT
HIGHLIGHTS OUT. TEMPERATURES REBOUND MONDAY AND TUESDAY AS RIDGE
EXPANDS WEST. WEAK WAVE TO MOVE THROUGH TUESDAY NIGHT INTO
WEDNESDAY MORNING SLIGHT CHANCES RETAINED FOR SOUTHWEST INTO NORTH
CENTRAL NEBRASKA. CHANCES FOR PRECIPITATION RETURN TO THE FORECAST
THURSDAY AND CONTINUE THROUGH THE END OF THE PERIOD AS ENERGY
EJECTS FROM A CLOSED LOW OFF THE PACIFIC COAST AND TEMPERATURES
RISING INTO THE 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1118 PM CDT SAT MAY 9 2015
A POWERFUL UPPER LEVEL STORM SYSTEM WILL TRACK ACROSS EASTERN
COLORADO INTO WESTERN NEBRASKA OVERNIGHT TONIGHT INTO SUNDAY.
WIDESPREAD RAIN AND MVFR TO IFR CIGS ARE EXPECTED AT THE KLBF AND
KVTN TERMINALS THROUGH 00Z MONDAY. RAIN MAY MIX WITH SNOW AT THE
KVTN TERMINAL WITH VISBYS AS LOW AS 2SM OVERNIGHT. FLT CONDS WILL
IMPROVE SUNDAY EVENING WITH CIGS INCREASING TO 5000 FT AGL AT THE
KLBF TERMINAL...AND 1500 FT AGL AT THE KVTN TERMINAL.
&&
.HYDROLOGY...
ISSUED AT 345 PM CDT SAT MAY 9 2015
THE ONGOING LARGE SCALE AND LONG DURATION HEAVY PRECIP EVENT OVER
THE HIGH PLAINS WILL LEAD TO FLOODING CONCERNS NEXT WEEK ON THE
SOUTH PLATTE RIVER IN SOUTHWEST NEBRASKA INCLUDING
DEUEL...KEITH...AND LINCOLN COUNTIES. AS OF SATURDAY MORNING THE
SOUTH PLATTE RIVER IS ALREADY EXPERIENCING ABOVE NORMAL FLOWS DUE TO
SNOW MELT RUNOFF IN THE FRONT RANGE MOUNTAINS OF COLORADO. LATEST
RIVER FORECAST PROJECTIONS SHOW AN INCREASING THREAT FOR SIGNIFICANT
FLOODING BY THE SECOND HALF OF NEXT WEEK. HOWEVER...HIGH UNCERTAINTY
STILL REMAINS IN THE AMOUNT OF OBSERVED/FORECAST RAINFALL IN
NORTHEAST COLORADO AND WESTERN NEBRASKA...AS WELL AS HOW IT WILL
IMPACT UPSTREAM FLOWS ON THE SOUTH PLATTE RIVER. RIVER FORECASTS
WILL BE CLOSELY MONITORED AND UPDATED AS MORE INFORMATION BECOMES
AVAILABLE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM MDT SUNDAY FOR NEZ022-023-056-
094.
WINTER STORM WARNING UNTIL 6 PM MDT SUNDAY FOR NEZ004.
&&
$$
SHORT TERM...CLB
LONG TERM...POWER
AVIATION...CLB
HYDROLOGY...MARTIN
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
835 AM PDT SUN MAY 10 2015
.SYNOPSIS...CLOUDS AND PERHAPS A SHOWER WILL PASS ACROSS NORTHERN
MOHAVE COUNTY TODAY AS MOISTURE LINGERS ON THE BACK SIDE OF A
DEPARTING STORM SYSTEM. OTHERWISE EXPECT DRY CONDITIONS WITH A
CONTINUED WARMING TREND THROUGH MONDAY. A SYSTEM WILL PASS BY
NORTHWEST OF THE AREA MONDAY NIGHT INTO TUESDAY BRINGING SOME CLOUDS
AND BREEZY CONDITIONS. ANOTHER STORM SYSTEM COULD IMPACT THE AREA
LATE NEXT WEEK WITH COOLER WEATHER AND SHOWERS POSSIBLE ON FRIDAY
AND SATURDAY.
&&
.UPDATE...
ONLY MADE MINOR ADJUSTMENTS TO TEMPS AND SKY THIS MORNING TO ACCOUNT
FOR CURRENT CONDITIONS/TRENDS. ONLY A SMALL CHANCE OF A SHOWER
ACROSS NORTHERN MOHAVE COUNTY TODAY. LAST FEW RUNS OF THE HRRR DON`T
SHOW MUCH OF ANYTHING. EXPECT A WARMER DAY THAN YESTERDAY AS RIDGING
ALOFT BUILDS OVER THE REGION. NO OTHER UPDATES ANTICIPATED THIS
MORNING.
&&
.PREVIOUS DISCUSSION...
305 AM PDT SUN MAY 10 2015
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT.
A NICE MOTHER`S DAY IS EXPECTED ACROSS THE AREA TODAY FOR THE MOST
PART AS MID/UPPER LEVEL RIDGE STARTS TO BUILD IN. THIS WILL PROMOTE
FURTHER WARMING AND LOTS OF SUNSHINE. HIGH TEMPS WILL RISE ABOUT 8-
10 DEGREES FROM SATURDAY BUT IN MOST SPOTS STILL BE A FEW DEGREES
BELOW NORMAL. THE ONLY EXCEPTION TO TODAY`S STELLAR WEATHER WILL BE
IN THE ARIZONA STRIP AREA WHERE LINGERING MOISTURE AND ENERGY ON THE
BACK SIDE OF THE HIGH PLAINS COLD LOW`S BROAD CIRCULATION TRIGGERS
SOME CLOUDS AND POSSIBLY A QUICK SHOWER OR SPRINKLE THIS AFTERNOON.
OUR ATTENTION WILL NOW TURN TO THE NEXT AREA OF LOW PRESSURE
PRESENTLY OFF THE COAST OF WASHINGTON. THIS FEATURE IS EXPECTED TO
SWING ACROSS THE PAC NW MONDAY THROUGH TUESDAY NIGHT. FOR OUR AREA
IT WILL STAY WELL ENOUGH TO THE NORTHWEST THAT ALL WE WILL SEE IS AN
INCREASE IN CIRRUS (ALTHOUGH IT DOES NOT LOOK LIKE AN OVERABUNDANCE
OF IT) AND AN INCREASE IN SOUTHWEST TO WEST WINDS BOTH MONDAY AND
TUESDAY IN THE AFTERNOON AND EVENING HOURS WITH GUSTS OF 15-25 MPH.
THE INCREASED SOUTHWEST FLOW WILL HELP TO MIX THE ATMOSPHERE BETTER
AND PUSH TEMPS BACK UP A FEW MORE DEGREES FOR MONDAY WITH NEAR
STATUS-QUO TEMPS ON TUESDAY. THIS WILL PUT HIGHS A FEW DEGREES ABOVE
NORMAL FOR A CHANGE WHICH MEANS BACK TO THE 90-102 RANGE FOR THE
LOWER ELEVATIONS OF THE MOJAVE DESERT. I SIDED WITH THE WARMER END
OF GUIDANCE BOTH DAYS FOR HIGH TEMPS.
.LONG TERM...WEDNESDAY THROUGH SATURDAY.
DRY SOUTHWEST FLOW TO START THE PERIOD WILL GIVE WAY TO INCREASING
SOUTHERLY FLOW BY THURSDAY AS LOW PRESSURE NEARS THE WEST COAST. BY
FRIDAY THERE ARE CRITICAL MODEL DISAGREEMENTS ON THE POSITION AND
DEPTH OF THE LOW AS WELL AS A MOISTURE PLUME WRAPPING AROUND ITS
SOUTHEAST SEMICIRCLE. THIS WILL MAKE A BIG DIFFERENCE IN THE
PROBABILITY AND PLACEMENT OF SHOWERS AND THUNDERSTORMS OVER THE CWA
FRIDAY AND SATURDAY. FOR NOW HAVE KEPT THE BRUSH BROAD AND THE MAX
POPS RELATIVELY LOW DUE TO THESE UNCERTAINTIES. NEAR NORMAL
TEMPERATURES WEDNESDAY WILL START TO COME DOWN ON THURSDAY AND THEN
CRASH FRIDAY AND SATURDAY AS THE LOW MOVES IN. EXPECT BREEZY SOUTH
WINDS WEDNESDAY AND THURSDAY AND POTENTIALLY STRONGER WEST WINDS
FRIDAY AND SATURDAY /DEPENDING ON HOW FAR SOUTH THE LOW CENTER
DIGS/.
&&
.AVIATION...FOR MCCARRAN...WINDS SHOULD FAVOR TYPICAL DIURNAL
DIRECTIONAL TRENDS AT 8 KTS OR LESS THROUGH TONIGHT UNDER A
RELATIVELY CLEAR SKY.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...AN ISOLATED SHRA IS POSSIBLE THIS AFTERNOON IN NORTHERN
MOHAVE COUNTY WITH SCT-BKN CLOUDS AOA 6K-10K FEET. OTHERWISE A
RELATIVELY CLEAR SKY IS EXPECTED ACROSS THE AREA. OVERALL WINDS
SHOULD MAINLY FOLLOW DIURNAL DIRECTIONAL TRENDS AT 12 KTS OR LESS
THROUGH TONIGHT.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT
REQUESTED THROUGH WEDNESDAY NIGHT. SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES LATER THIS WEEK.
&&
$$
UPDATE...PADDOCK
SHORT TERM/AVIATION...STACHELSKI
LONG TERM...MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
FORECAST DISCUSSION FOLLOWS.
WILL CONTINUE CHC/LKLY POP THROUGH NIGHTFALL BUT A RAPID DECREASE
IN COVERAGE IS EXPECTED WITH LOSS OF HEATING. A RESIDUAL LAYER OF
ELEVATED INSTABILITY IS PROGGED IN SOUNDINGS TO PERSIST WELL AFTER
DARK...SO ALTHOUGH THE HRRR SHOWS NO PRECIP AFTER MIDNIGHT...HAVE
OPTED TO KEEP SCHC/ISO SHOWERS THROUGH THE OVERNIGHT.
THE OTHER INTERESTING FEATURE TONIGHT HAS BEEN SEA FOG WHICH
DEVELOPED SOMEWHAT SURPRISINGLY THIS AFTN AND ADVECTED INTO THE
GRAND STRAND AND BRUNSWICK COUNTY. WE ARE BEYOND THE
CLIMATOLOGICALLY FAVORED SEASON FOR SEA FOG...AND THE LOCAL DECISION
TREE SUGGESTS VSBYS SHOULD BE UNRESTRICTED. YET...SEA FOG DID
DEVELOP AND BOTH THE HORRY AND BRUNSWICK COUNTY COASTS ARE "SOCKED
IN` AS OF THIS WRITING. IT IS BELIEVED THAT UPWELLING FROM LONG
DURATION OFFSHORE WINDS ON THE BACKSIDE OF RECENTLY-DEPARTED
TROPICAL STORM ANA COOLED THE SHELF WATERS ENOUGH TO PRODUCE THE
REQUIRED AIR-TO-OCEAN TEMP GRADIENT, THIS COMBINED WITH THE SW FLOW
TO CREATE LONG ENOUGH PARCEL RESIDENCE TIMES FOR SATURATION AND SEA
FOG. CERTAINLY AN INTERESTING SITUATION AND ONE FROM WHICH WE CAN
LEARN! STILL EXPECT VISIBILITY TO IMPROVE IN THE NEXT HOUR OR TWO AS
CONDITIONS ARE FAR FROM IDEAL FOR PERSISTENT SEA FOG.
MINS TONIGHT WILL BE HELD ABOVE CLIMO THANKS TO CONTINUED SW RETURN
FLOW...AND LOWS WILL DROP TO A DEGREE OR TWO EITHER SIDE OF
70...WARMEST AT THE COAST. GUIDANCE IS SUGGESTING STRATUS
DEVELOPMENT TONIGHT...AND IN THIS MOIST COLUMN IT IS DEFINITELY
PLAUSIBLE. HAVE SHOWN AN INCREASE IN CLOUD COVER AFTER
MIDNIGHT...WHICH WILL ALSO HELP TO KEEP MINS ELEVATED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...WEAK COLD FRONT WILL PUSH ACROSS THE AREA
LATE TUE NIGHT. AHEAD OF THE FRONT THE ENVIRONMENT APPEARS RIP FOR
DEVELOPMENT OF AFTERNOON CONVECTION. DEEP MOISTURE IS PRESENT WITH
FORECAST SOUNDINGS CARRYING PRECIPITABLE WATER VALUES OF 1.5 TO
1.6 INCH...WHICH IS WITHIN THE HIGHEST 10% FOR EARLY MAY.
SOUNDINGS CONTINUE TO ADVERTISE ML CAPE IN THE 2K TO 2.5K J/KG
RANGE WEST OF THE SEA BREEZE...WHICH WEST-SOUTHWEST FLOW SHOULD
KEEP CLOSER TO THE COAST. THE AFOREMENTIONED SEA BREEZE AND
PREFRONTAL TROUGH ARE LIKELY TO INITIATE AFTERNOON CONVECTION WITH
OUTFLOW DEVELOPING ADDITIONAL STORMS. MUCH OF THE AREA REMAINS IN
THE SPC DAY 2 OUTLOOK MARGINAL AREA AND FORECAST SOUNDINGS DO
SUGGEST SOME POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS.
HOWEVER...ORGANIZED WIDESPREAD STRONG/SEVERE ACTIVITY IS NOT
LIKELY. SHEAR IS NOT PARTICULARLY STRONG BUT LIFTED INDEX VALUES
ARE -5C TO -6C AND FAIRLY STRONG UPDRAFTS SHOULD BE POSSIBLE.
FREEZING LEVEL AROUND 13K FT LIKELY RULES OUT SIZABLE HAIL SO THE
MAIN THREAT WOULD BE ISOLATED DAMAGING WIND GUSTS.
COLD FRONT PUSHES ACROSS THE AREA TUE NIGHT WITH MUCH DRIER AIR MASS
BUILDING IN BEHIND IT. PRECIPITABLE WATER VALUES DROP OVER AN INCH
TUE INTO WED. DEEP NORTHWEST FLOW/MID LEVEL SUBSIDENCE WILL KEEP
SKIES CLEAR WED AFTERNOON. THE ONLY CAVEAT WILL BE ACROSS THE
COASTAL SC COUNTIES. THERE IS A WEAK SHORTWAVE CROSSING SC...WHICH
DOES HELP PUSH THE FRONT THROUGH...BUT THIS SHORTWAVE COULD TAKE A
BIT LONGER TO PUSH OFF THE SC COAST. IF THAT HAPPENS CLOUDS COULD
LINGER ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA. AT THIS POINT
DO NOT THINK PRECIP WILL LINGER INTO WED BUT WILL CARRY A NON-ZERO
POP FOR THE MORNING HOURS.
TEMPS WELL ABOVE CLIMO TUE WILL COOL OFF QUITE A BIT WED BUT HIGHS
STILL END UP RIGHT AROUND CLIMO...SHOWING JUST HOW WARM TUE IS GOING
TO BE. LOWS ABOVE CLIMO TUE NIGHT WILL BE NEAR TO SLIGHTLY BELOW
CLIMO WED NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 AM SUNDAY... MID LEVEL RIDGE OVERHEAD THURSDAY WHILE SURFACE
HIGH REMAINS TO OUR NORTH. LIKE WEDNESDAY WE EXPECT ANOTHER SUNNY
AND SEASONABLE DAY WITH FAIRLY LOW HUMIDITY. THIS WILL CHANGE
THURSDAY NIGHT INTO FRIDAY AS BOTH MOVE EASTWARD. THE WARMING WILL
BE RATHER GENTLE BUT THE HUMIDITY CREEPING UP MORE NOTICEABLE. THE
WEEKEND SHOULD THUS BRING FAIRLY SEASONABLE WARMTH AND HUMIDITY BUT
ALSO AT LEAST A SCATTERING OF MAINLY DIURNAL CONVECTION.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...A MIXTURE OF VFR/MVFR/IFR THIS EVENING DUE TO SHRA/TSRA
ALONG WITH FOG/LOW CIGS WILL GRADUALLY DETERIORATE TO MAINLY
MVFR/IFR. ON TUESDAY...EXPECT VFR WITH AFTERNOON/EVENING ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS IN ASSOCIATION WITH AN
APPROACHING COLD FRONT.
LATEST RADAR DEPICTS SHOWERS AND THUNDERSTORMS MOVING ACROSS
PORTIONS OF THE FORECAST AREA THIS EVENING. EXPECT THIS ACTIVITY TO
GRADUALLY TAPER OFF TONIGHT...WITH PERIODS OF SHRA/TSRA MAINLY AT
KLBT/KILM. GIVEN STABLE LAYER ACROSS KCRE/KMYR...DO NOT ANTICIPATE
MUCH IN THE WAY OF RAINFALL...BUT WOULD NOT ENTIRELY RULE OUT -SHRA.
SOUTHWEST WINDS AOB 10 KTS WILL CONTINUE TONIGHT. INTO THE OVERNIGHT
HOURS...ANTICIPATE LOW CIGS WITH AREAS OF FOG ALONG THE COAST...WITH
PATCHY FOG INLAND...CREATE MVFR/IFR. ON TUESDAY...CONDITIONS WILL
IMPROVE TO VFR WITH SHRA/TSRA ANTICIPATED INTO THE AFTERNOON/EVENING
HORUS IN ASSOCIATION WITH AN APPROACHING COLD FRONT. WEST-SOUTHWEST
WINDS AOB 15 KTS WITH GUSTS AROUND 20 KTS POSSIBLE THROUGHOUT THE
DAY.
EXTENDED OUTLOOK...SCATTERED SHOWERS POSSIBLE ON FRIDAY. OTHERWISE
EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 758 PM MONDAY...SW FLOW WILL CONTINUE THROUGH TONIGHT WITH
FAIRLY STEADY 10- 15 KT SW WINDS...ALTHOUGH A FEW GUSTS TO 20 KTS
WILL BE POSSIBLE OVERNIGHT...ESPECIALLY NEAR SHOWERS OR ISOLATED
TSTMS. SEAS 2-4 FT...WITH A 6-7 SECOND PERIOD WAVE PREDOMINANT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL
INCREASE AS GRADIENT AHEAD OF THE FRONT TIGHTENS. SPEEDS PEAK AROUND
20 KT IN TUE AFTERNOON AND EVENING WITH SEAS RUNNING 3 TO 4 FT.
WINDS VEER TO WESTERLY LATE TUE NIGHT AS THE FRONT CROSSES THE
WATERS. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT LIMITS THE
STRENGTH OF THE GRADIENT AND DEVELOPING OFFSHORE FLOW WILL BE UNDER
15 KT EARLY WED. WINDS WILL QUICKLY VEER TO NORTHEAST FOR WED BUT
GRADIENT REMAINS ILL DEFINED AND SPEEDS STAY 15 KT WITH SEAS
RUNNING 2 TO 3 FT THROUGH THE END OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM SUNDAY... THE HIGH LOCATED TO OUR NORTH DURING THE
SHORT TERM PROGRESSES EAST DURING THE LONG TERM. WINDS VEER FROM N
TO E EARLY IN THE PERIOD AND SHALL MORE OR LESS REMAIN SAVE FOR
PERHAPS A SLIGHT ADDITIONAL VEER TO SE BY FRIDAY. THERE WILL BE NO
APPRECIABLE SWELL ENERGY TO SPEAK OF SO THE FAIRLY MINOR WIND
WAVES WILL BE THE DOMINANT SEA STATE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW/MJC
SHORT TERM...III
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
750 PM EDT MON MAY 11 2015
.SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TUESDAY
AFTERNOON AND EVENING. COOL HIGH PRESSURE WILL BUILD INTO THE AREA
THROUGH MID-WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 315 PM MONDAY...
WEAKENING REMAINS OF TC ANA WILL CONTINUE TO MOVE NORTHEASTWARD INTO
SOUTHEAST VA THIS AFTERNOON AND EVENING WITH AN EXPECTED INCREASE IN
ACCELERATION AS SW FLOW ALOFT STRENGTHENS IN ADVANCE OF A MID/UPPER
LEVEL TROUGH MOVING NORTHEASTWARD INTO THE MID/UPPER VALLEY.
IN THE WAKE OF TC ANA EXITING THE AREA...MODERATE DESTABILIZATION OF
2000-2500 J/KG PER SPC MESOANALYSIS HAS DEVELOPED IN RESPONSE TO
STEEP LOW-LEVEL LAPSE RATES ATOP A SEASONABLY MOIST BOUNDARY LAYER
FEATURING BL DEWPOINTS IN THE UPPER 60S TO LOWER 70S. FORCING FOR
ASCENT THIS AFTERNOON AND EVENING LOOKS TO BE DRIVEN BY TWO SEPARATE
WEAK FEATURES...1)ALONG SHALLOW CONVERGENCE ATTENDANT TO A
DEVELOPING SURFACE TROUGH IN THE LEE OF THE MOUNTAINS AND 2) A WEAK
UPPER LEVEL DISTURBANCE OVER SW NC/SC.
INITIALLY...EXPECT CONVECTION TO BE CONFINED TO THE WESTERN PIEDMONT
AND SANDHILLS/SOUTHERN COASTAL PLAIN WHERE THE SUPPRESSIVE INFLUENCE
OF SUBSIDENCE ON THE WESTERN PERIPHERY OF TC ANA`S REMNANTS WILL NO
LESS. GIVEN WEAK FORCING...EXPECT CONVECTION TO BE LARGELY DIURNAL
IN NATURE...AND THUS EXPECT MUCH OF THE ACTIVITY TO DROP OFF QUICKLY
AFTER SUNSET. HOWEVER...THE LATEST HRRR SUGGEST INITIAL STORMS OUT
WEST COULD PERSIST THROUGH MIDNIGHT AS THEY WORK SLOWLY EASTWARD
INTO THE COASTAL PLAIN. HAVE EXTENDED SMALL CHANCE POPS THROUGH 05-
06Z. WRT TO SEVERE WX...WEAK DEEP LAYER SHEAR OF 10-15 KTS WILL
PRECLUDE A MORE ORGANIZED THREAT. HOWEVER...GIVEN MODERATE
INSTABILITY AND DCAPE ~1000J/KG CANNOT RULE OUT AN ISOLATED SEVERE
STORM CAPABLE OF PRODUCING LOCALIZED WIND DAMAGE....ESPECIALLY IN
THE WEST IN PROXIMITY TO DRIER AIR.
UNDER PARTLY TO MOSTLY CLOUDY MID AND HIGH CLOUDS...EXPECT MILD
OVERNIGHT LOWS IN THE UPPER 60S TO NEAR 70.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 315 PM MONDAY...
MID AND UPPER LEVEL FLOW REALLY FLATTENS OUT...BECOMING WESTERLY ON
TUESDAY AS THE WELL REMOVED UPPER TROUGH TRAVERSE THE UPPER GREAT
LAKES/NEW ENGLAND. ATTENDANT SURFACE LOW TRACKING THROUGH SE CANADA
WILL DRAG A COLD FRONT THROUGH THE AREA BETWEEN 18Z TUESDAY IN THE
WEST TO 00 TO 03Z IN THE EAST. GUIDANCE SUGGESTS BL DEWPOINTS WILL
BE APT TO MIX OUT A BIT...ESPECIALLY OVER THE WESTERN PIEDMONT
TUESDAY AFTERNOON. THE WESTERLY COMPONENT ALOFT AND LACK OF SUPPORT
ALOFT WILL TEND TO SUPPRESS CONVECTION ACROSS A LARGE CHUNK OF THE
FORECAST WITH CONVECTION MOST APT TO FIRE ACROSS EASTERN PIEDMONT
AND COASTAL PLAIN(I-95 CORRIDOR)...WHERE LINGERING LOW-LEVEL
MOISTURE AND STRONG INSOLATION COULD SUPPORT MODERATE TO STRONG
DESTABILIZATION OF 2000-3000 J/KG OF SBCAPE. WRT TO SEVERE
POTENTIAL...DEEP LAYER SHEAR MAY BE MARGINALLY BETTER THAN TODAY...
BUT NOT BY MUCH...PARTICULARLY IN THE EAST. THUS A FEW STRONG TO
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING LOCALIZED WIND DAMAGE MAY
DEVELOP ACROSS THE EASTERN PIEDMONT/COASTAL PLAIN AREAS.
LOW-LEVEL THICKNESSES WILL BE MORE REPRESENTATIVE OF MID TO LATE
JUNE AS OPPOSED TO EARLY MAY. EXPECT HIGHS IN THE UPPER 80S TO LOWER
90S...WHICH WOULD BE THE FIRST TIME WE REACHED 90 DEGREES AT KRDU
AND KFAY.
SKIES SHOULD CLEAR OUT TUESDAY EVENING/NIGHT WITH CAA DRIVING
OVERNIGHT LOWS. LOWS RANGING FROM MID 50S NW TO LOWER 60S SE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE GREAT
LAKES WEDNESDAY THROUGH THURSDAY...BEFORE SHIFTING OFFSHORE THURSDAY
NIGHT INTO FRIDAY. AT THE SAME TIME...MID LEVEL RIDGING WILL BUILD
OVER THE AREA FROM THE EAST. MUCH COOLER AND DRIER AIR WILL FILTER
INTO THE REGION...RESULTING IN A PERIOD OF DRY WEATHER AND NEAR TO
SLIGHTLY BELOW NORMAL TEMPS.
AS THE SURFACE HIGH CONTINUES TO SHIFT OFFSHORE ON FRIDAY...MOISTURE
WILL BEGIN TO RECOVER ON THE BACK SIDE OF THE HIGH. HOWEVER...THE
MID LEVEL RIDGING WILL STICK AROUND FOR A WHILE LONGER WHICH MAY
PREVENT WIDESPREAD CONVECTION. AS OF NOW...IT APPEARS THE BEST
CHANCE OF A SHOWER OR STORM WILL BE ACROSS THE WESTERN PIEDMONT ON
FRIDAY AND SATURDAY...WITH CHANCES SPREADING EAST (AND INCREASING)
SUNDAY INTO MONDAY AS MOISTURE AND INSTABILITY INCREASES EVEN MORE.
TEMPS WILL GRADUALLY WARM EACH DAY...WITH HIGHS GENERALLY IN THE MID
80S AND OVERNIGHT LOWS IN THE MID 60S BY EARLY NEXT WEEK.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 750 PM MONDAY...
CURRENTLY...SCATTERED SHOWERS AND STORMS ACROSS THE SANDHILLS AND
SOUTHERN COASTAL PLAIN POSE ONLY A THREAT TO KFAY IN THE NEXT COUPLE
HOURS. VFR CONDITIONS PREVAIL...AND ANY SUB-VFR CONDITIONS WILL BE
BRIEF AND CONFINED TO THE HEAVIEST SHOWERS/STORMS. MEANWHILE..A
PRONOUNCED SEABREEZE/OUTFLOW SURGE NORTH INTO THE PIEDMONT HAS BEEN
ACCOMPANIED BY SOME WIND GUSTS AROUND 30KT AS WINDS SHIFT TO
SOUTHERLY. WHILE LIKELY NOT AS STRONG...A WIND SHIFT CAN BE
EXPECTED AT KRDU AROUND 00Z. TO THE WEST...ANOTHER OUTFLOW BOUNDARY
ASSOCIATED WITH EARLIER CONVECTION IN THE MOUNTAINS IS MOVING INTO
THE WESTERN PEIDMONT...WHICH MAY RESULT IN SOME RENEWED CONVECTION
AROUND THE TRIAD TERMINALS (KGSO/KINT) THROUGH 02Z.
ONCE THE CONVECTION DIES DOWN...WHICH IS ANTICIPATED TO OCCUR BY
MIDNIGHT...THERE IS A CHANCE OF SOME STRATUS...MAINLY ACROSS
EASTERN/SOUTHERN AREAS. CONFIDENCE ISNT VERY HIGH...BUT NEAR TERM
GUIDANCE SUGGEST AT LEAST SOME SCATTERED LOW CLOUDS FROM KFAY TO
KRWI BY 10Z. WINDS WILL REMAIN OUT FO THE SOUTHWEST AT 4-8KT.
A COLD FRONT WILL APPROACH FROM THE WEST DURING THE DAY ON TUESDAY.
SOUTHWESTERLY WINDS WILL ICNREASE TO AROUND 12KT AHEAD OF THE
FRONT...AND THE NEST CHANCE FOR SHOWERS/STORMS IS EXPECTED TO BE
EAST OF KRDU TOWARD KRWI AND KFAY.
LOOKING AHEAD: EXPECT DRY VFR CONDITIONS TUESDAY NIGHT THROUGH
FRIDAY ASSOCIATED WITH COOL HIGH PRESSURE BUILDING OVER THE AREA.
THE HIGH WILL PUSH OFFSHORE ON FRIDAY. SOUTHERLY RETURN FLOW ON THE
WESTERN PERIPHERY OF THE HIGH WILL BRING AN INCREASE LIKELIHOOD OF
SUB-VFR CONDITIONS IN MORNING FOG AND/OR STRATUS ALONG WITH A
CHANCE OF MAINLY AFTERNOON SHOWERS AND STORMS LATE FRIDAY NIGHT
AND INTO THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT/CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...KRD
AVIATION...CBL/22
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
345 PM EDT SUN MAY 10 2015
.SYNOPSIS...
ANA WILL GRADUALLY WEAKEN AND LIFT NORTHEAST OVER THE COASTAL
PLAIN TONIGHT INTO MONDAY. A COLD FRONT APPROACHES FROM THE
NORTHWEST TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL
THEN BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 345 PM SUN...REMNANTS OF ANA CURRENTLY OVER SE NC...AND
SLOWLY LIFTING NORTH NORTHEAST. HEAVY RAINS HAVE ABATED FOR THE
TIME BEING...WITH BULK OF RAIN SHOWERS MORE STRATIFORM AND
CONCENTRATED NEAR THE STORM CENTER. THINKING THAT CONVECTIVE BANDS
OF RAIN SHOWERS WITH EMBEDDED THUNDER...HEAVY AT TIMES...WILL
REDEVOLOP OVERNIGHT PER MESOSCALE CONVECTIVE INITIATING MODELS.
WILL LEAVE FLOOD WATCH INTACT. ALSO...ISOLATED TOR THREAT MAY
DEVELOP AS FAVORABLE LOW LEVEL SHEAR VALS INC OVERNIGHT AS CENTER
OF ANA MAKES HER WAY THROUGH THE COASTAL PLAIN/INTERSTATE 95
CORRIDOR. HIGH RES MODELS INDICATE AN UPTICK IN UPDRAFT HELICITY
AFTER AROUND 04Z...AND WITH SFC WINDS STILL BACKED SSE...THIS
WOULD YIELD INC LOW LEVEL HELICITY AS H85MB WINDS VEER SWRLY. WILL
CONTINUE TO HIGHLIGHT THESE THREATS IN HWO. MUGGY OVERNIGHT LOWS
WITH MOST AREAS DROPPING NOW LOWER THAN 70 OVERNIGHT.
&&
.SHORT TERM /MONDAY/...
AS OF 345 PM SUN...SHOULD SEE THREAT FOR HEAVY RAIN SHOWERS END
THROUGH THE EARLY MORNING WITH PRECIP COVERAGE AND INTENSITY
TAPERING OFF SOMEWHAT AS REMNANTS OF THE SYSTEM WITH BEST LIFT
MOVE NORTHEAST INTO VA. STILL HUNG ONTO LIKELY POPS ACROSS THE
NORTH WITH HIGH CHANCE/SCT SOUTHERN AREAS. TEMPS WILL BE HELD DOWN
AGAIN WITH THE MOSTLY CLOUDY SKIES...THOUGH SOME SUN COULD BREAK
OUT ESP IN THE AFTERNOON WITH READINGS IN THE 80S ACROSS THE SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
REMNANT ANA LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT.
HOWEVER A MOIST SW FLOW WILL REMAIN IN PLACE TUESDAY AHEAD OF
SHEARING UPPER TROF AND ASSOCD SFC COLD FRONT WITH CHANCES FOR
SCATTERED SHOWERS CONTINUING. MOIST BNDRY LAYER SUGGESTS MOCLOUDY
SKIES THRU TUESDAY MORNING THEN SUNNY BREAKS DEVELOP WITH MIXING
ALLOWING TEMPS TO SOAR TO NEAR 90 DEGREES INLAND TUESDAY AFTERNOON.
DESTABILIZATION AND SPEED SHEAR MAY BE SUPPORTIVE OF STRONG TO
SEVERE TSTORMS TUESDAY AFTERNOON INTO EVENING.
COLD FRONT SLIDES THRU THE AREA LATE TUESDAY NIGHT THEN UPPER RIDGE
BUILDS EAST WITH SFC HIGH RIDGING IN FROM THE NORTH. THE DRIER, MORE
STABLE AIRMASS WILL KEEP RAIN CHANCES AT BAY THRU AT LEAST THURSDAY
AND POSSIBLY THRU THE END OF THE WEEK UNLESS SHORT WAVE ENERGY/DEEP
MOISTURE CAN PENETRATE UPPER RIDGE MOVING OFFSHORE.
MAY BE INCREASINGLY UNSETTLED NEXT WEEKEND AS ZONAL FLOW AND STALLED
SFC BNDRY LINGER OVER THE AREA.
AFTER A HOT/HUMID TUESDAY, TEMPERATURES WILL SETTLE TO SLIGHTLY BLO
NORMAL LEVELS THRU THE END OF THE WEEK. TEMPS MAY REBOUND TO MORE
SEASONAL LEVELS NEXT WEEKEND DEPENDING ON PLACEMENT OF STALLED OUT
SFC FRONT.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
AS OF 130 PM SUN...VFR/MVFR CONDITIONS OVER EASTERN NORTH
CAROLINA TAFS AS CENTER OF ANA MOVES NORTH INTO NC TO OUR SW.
RAIN BANDS ROTATING ACROSS REGION FROM OFFSHORE EXTENDS FROM
ONSLOW/CARTERET COUNTY TO THE NW AS IT CONTINUES TO PUSH TO THE
NORTH AND AFFECTING KEWN AND KPGV REDUCING CIGS TO MVFR. EXPECT TO
SEE MORE STEADY RAIN STARTING IN LATER THIS AFTERNOON AS CENTER OF
ANA MOVES SLOWLY NORTH. HAVE MODERATE CONFIDENCE IN MVFR
CONDITIONS ACROSS ALL TERMINALS WITH ISOLATED IFR CONDITIONS.
WINDS HAVE NOT BEEN AN ISSUE WITH GUSTS LIMITED TO STRONGER BANDS
MOVING ACROSS THE TERMINALS MIXING STRONGER WINDS ALOFT DOWN
BRIEFLY. HRRR AND HIRESW-ARW MODEL HAVE A GOOD HANDLING ON BANDED
PRECIPITATION MOVING ACROSS THE REGION THROUGH TONIGHT. TIMING OF
BANDS WILL BE DIFFICULT TO ACCURATELY PREDICT BUT AS ANA
TRANSITIONS TO MORE EXTRATROPICAL THIS EVENING AND TONIGHT BANDED
PRECIPITATION WILL BECOME MORE STARTIFORM WITH LOWER CEILINGS. AS
ANA PULLS AWAY WINDS WILL SHIFT TO THE SW THEN W IN THE MORNING
AFTER 12Z.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANA REMNANT LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT,
HOWEVER RESIDUAL LOW LEVEL MOISTURE AND SCATTERED PRECIPITATION MAY
SUPPORT SUB-VFR CONDITIONS THRU TUESDAY MORNING. MIXING WILL SCATTER
OUT CLOUD COVER BY MIDDAY TUESDAY THEN SCATTERED SHOWER AND
THUNDERSTORMS (SOME OF WHICH CUD BE STRONG/SEVERE) AFFECT THE AREA
TUESDAY AFTERNOON AND EVENING. DRYING AIRMASS BUILDS IN AFTER A COLD
FRONT PASSAGE LATE TUESDAY NIGHT WITH PREDOMINATE VFR EXPECTED
THEREAFTER.
&&
.MARINE...
AS OF 345 PM SUNDAY...GUSTY S TO SE WINDS THIS AFTERNOON MAINLY
20 TO 25 KT SOUTHERN WATERS WITH LIGHTER WINDS NORTHERN WATERS
AROUND 10 TO 15 KTS. SEAS IN THE 7-9 FOOT RANGE SOUTHERN WATERS
TO 3 TO 5 FEET NORTHERN WATERS. THE REMNANTS OF ANA WILL LIFT
NORTHEAST ACROSS THE COASTAL PLAIN OVERNIGHT WITH WINDS BECOMING
SOUTHERLY AND INC ACROSS ALL WATERS AND THE PAMLICO SOUND. CURRENT
SCA LOOKS IN GOOD SHAPE.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
DESPITE DEPARTING ANA, MARINE WEATHER REMAINS ACTIVE THRU MUCH OF
THIS WEEK. MODERATE TO STRONG SW WINDS AND LINGERING SEAS WILL KEEP
SMALL CRAFT ADVISORIES LIKELY THRU TUESDAY NIGHT AHEAD OF A COLD
FRONT PASSAGE LATE TUESDAY NIGHT OR EARLY WEDNESDAY. MAY BE A LULL
IN SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY BEFORE STRONGER POST
FRONTAL N/NE WINDS KICK UP AGAIN WED NIGHT INTO THURSDAY. WINDS/SEAS
GRADUALLY RELAX THU NIGHT FRIDAY AS PRESSURE GRADIENT DECREASES AT
THE COAST WITH HIGH BUILDING IN FROM THE NORTH.
&&
.HYDROLOGY...
FLOOD WATCH ISSUED THROUGH MON MORNING AS OCCASIONAL BANDS OF
HEAVY SHOWERS PIVOT ACROSS E NC THROUGH LATE TONIGHT. THE HEAVIER
SHOWERS WILL PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. HEAVIEST
RAIN THREAT LOOKS TO OCCUR OVERNIGHT TONIGHT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH THROUGH MONDAY MORNING FOR NCZ090>093-095-098.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR AMZ135-150.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT WEDNESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...BTC
MARINE...BTC/TL
HYDROLOGY...TL/RF
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
142 PM EDT SUN MAY 10 2015
.SYNOPSIS...
ANA WILL GRADUALLY WEAKEN AND MOVE NORTHWEST OVER NORTHERN SOUTH
CAROLINA TODAY...THEN LIFT NORTHEAST INLAND FROM THE COAST
TONIGHT AND MONDAY. A COLD FRONT APPROACHES FROM THE NORTHWEST
TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL THEN
BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1145 AM SUN...UPDATED FCST TO EXPIRE TROPICAL STORM
WARNING. GUSTY SOUTH TO SE WINDS WILL CONTINUE ESP NEAR THE COAST
THOUGH BIGGESET CONCERN WILL BE HEAVY RAIN THREAT TODAY. CONTINUED
CATEGORICAL POPS WESTERN HALF OF FA WITH HIGH LIKELY TO SCT ACROSS
THE FAR EAST. COULD SEE POCKETS OF SUNSHINE BREAK OUT BY THIS
AFTERNOON AND THIS WOULD EXACERBATE THE HEAVY RAIN THREAT AS ANY
INC IN INSTABILITY WILL AID IN CONVECTIVE SHOWER/TS COVERAGE
LATER. PWATS APPROACHING 2 INCHES WHICH IS ABOVE THE MAX FOR EARLY
TO MID MAY.
PREV DISC...AS OF 725 AM SUNDAY...ISSUED FLOOD WATCH FOR SW TIER.
RADAR AND SATL SHOW GOOD BANDING OF SHRA/ISOLD TSRA DEVELOPING E
OF ANA AND THIS LOOKS TO TRAIN OVER SRN TIER. WITH PRECIP WTR
VALUES APPROACHING 2 INCHES VERY HEAVY DOWNPOURS GOOD BET WITH
POTENTIAL FOR SOME TRAINING AND POSSIBLE FOOD CONCERNS.
PREV DISC...TROPICAL STORM ANA IS MOVING ASHORE NEAR MYRTLE BEACH
EARLY THIS MORN. BANDS OF SHRA CONT TO ROTATE NW ACROSS THE SW
HALF OF REGION AND THAT TREND SHLD CONT THRU THE MORN AS ANA
SLOWLY MOVES NNW. LATER TODAY ANA WILL BEGIN TO TURN N BUT REMAIN
SW OF ERN NC. WITH HEATING EXPECT CVRG OF SHRA/ISOLATED TSRA TO
GRAD INCREASE ACROSS AREA...CONT TO HAVE POPS RANGING FROM
CATEGORICAL OVER SRN SECTION TO CHC NE. LOCALLY HEAVY RAIN LIKELY
WITH PRECIP WTR VALUES REACHING NEAR 2 INCHES SRN TIER. SO FAR
HAVE NOT SEEN ANY SIGN OF ORGANIZED ROTATION IN ANY OF THE CELLS
OR BANDS OF SHRA/ISOLD TSRA. LATER TODAY WITH SOME HEATING MAY SEE
SLIGHTLY BETTER CHC OF TORNADO AS AREA BEGINS TO GET IN RIGHT
FLANK OF THE CIRC...ESPCLY S. HIGH IN THE UPR 70S TO LOWER
80S...GUSTY SE WINDS SRN AREAS CLOSER TO TS ANA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 225 AM SUNDAY...ANA WILL GRAD WEAKEN BUT SHLD SEE WELL
DEFINED CIRC MOVE NNE NEAR OR JUST E OF I95 OVERNIGHT. EXPECT
NUMEROUS SHRA/ISOLATED TSRA TO CONT WITH LOCALLY HEAVY RAIN A GOOD
BET AS TROP MOISTURE STREAMS N OVER ERN NC. TORNADO CHCS WILL
INCREASE OVERNIGHT AS ERN NC WILL BE IN MOST FAVORABLE RIGHT FLANK
OF THE CIRC...INSTAB IS WEAK AND THIS MAY LIMIT THREAT SOMEWHAT
BUT CERTAINLY THERE WILL BE A CHC OF A TORNADO OR TWO WITH
FAVORABLE SHEAR OVER THE REGION. GUSTY MAINLY SE TO S WINDS
EXPECTED ESPCLY COAST WITH MILD LOWS IN THE UPR 60S TO LOWER 70S.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
AS OF 329 AM SUN...REMNANTS OF TROPICAL STORM ANA WILL BE PUSHING
TOWARD THE NORTHEAST DURING THE DAY ON MONDAY. PRECIPITABLE WATERS
AROUND TWO INCHES COMBINED WITH ELEVATED CAPE AND GOOD DIRECTIONAL
/SPEED SHEAR WILL LEAD TO AN ACTIVE DAY WITH FLOODING AND ISOLATED
TORNADOES POSSIBLE.
UPPER TROUGH OVER THE CENTRAL PART OF THE COUNTRY WILL DRAG A COLD
FRONT TO NORTH CAROLINA ON TUESDAY. SOUTH SOUTHWESTERLY FLOW AHEAD
OF THE APPROACHING FRONT WILL CONTINUE THE CHANCE OF THUNDERSTORM
ACTIVITY ON TUESDAY WITH HIGH TEMPERATURES IN THE UPPER 80S. FRONT
EXPECTED TO EXIT OFF THE COAST ON WEDNESDAY MORNING WITH
PRECIPITATION CHANCES ENDING.
HIGH PRESSURE WILL BUILD OVER THE AREA WITH HIGH TEMPERATURES
DROPPING A COUPLE OF CATEGORIES INTO THE UPPER 70S TO LOWER 80S
THROUGH THE REMAINDER OF THE WORK WEEK. MODELS HINTING AT A WEAK
FRONT MOVING THROUGH NORTH CAROLINA OVER THE WEEKEND WITH A SMALL
CHANCE OF RAIN ASSOCIATED WITH IT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 12Z MONDAY/...
AS OF 130 PM SUN...VFR/MVFR CONDITIONS OVER EASTERN NORTH
CAROLINA TAFS AS CENTER OF ANA MOVES NORTH INTO NC TO OUR SW.
RAIN BANDS ROTATING ACROSS REGION FROM OFFSHORE EXTENDS FROM
ONSLOW/CARTERET COUNTY TO THE NW AS IT CONTINUES TO PUSH TO THE
NORTH AND AFFECTING KEWN AND KPGV REDUCING CIGS TO MVFR. EXPECT TO
SEE MORE STEADY RAIN STARTING IN LATER THIS AFTERNOON AS CENTER OF
ANA MOVES SLOWLY NORTH. HAVE MODERATE CONFIDENCE IN MVFR
CONDITIONS ACROSS ALL TERMINALS WITH ISOLATED IFR CONDITIONS.
WINDS HAVE NOT BEEN AN ISSUE WITH GUSTS LIMITED TO STRONGER BANDS
MOVING ACROSS THE TERMINALS MIXING STRONGER WINDS ALOFT DOWN
BRIEFLY. HRRR AND HIRESW-ARW MODEL HAVE A GOOD HANDLING ON BANDED
PRECIPITATION MOVING ACROSS THE REGION THROUGH TONIGHT. TIMING OF
BANDS WILL BE DIFFICULT TO ACCURATELY PREDICT BUT AS ANA
TRANSITIONS TO MORE EXTRATROPICAL THIS EVENING AND TONIGHT BANDED
PRECIPITATION WILL BECOME MORE STARTIFORM WITH LOWER CEILINGS. AS
ANA PULLS AWAY WINDS WILL SHIFT TO THE SW THEN W IN THE MORNING
AFTER 12Z.
LONG TERM /MON THROUGH THURSDAY/...
AS OF 346 AM SUN...REMNANTS OF ANA WILL BE MOVING THROUGH THE
EASTERN NORTH CAROLINA TAF SITES ON MONDAY WITH WIDSPREAD SUB VFR
CONDITIONS EXPECTED THROUGH THE DAY. RAIN...GUSTY WINDS...AND
SEVERE WEATHER WITH TORNADOES A POSSIBILITY. LLWS AND CROSS WIND
ALSO EXPECTED.
ANA WILL EXIT THE AREA MONDAY NIGHT WITH IMPROVING CONDITIONS. A
FRONT WILL APPROACH THE AREA WITH SUBVFR CONDITIONS POSSIBLE TUESDAY
AND TUESDAY EVENING AHEAD OF THE FRONT IN RAIN AND LOW CLOUDS. VFR
CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE FORECAST PERIODS
WITH HIGH PRESSURE OVER THE AREA.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1145 AM SUNDAY...UPDATED TO EXPIRE TS WARNING FOR THE
SOUTHERN WATERS. GUSTY S TO SE WINDS TODAY MAINLY 20 TO 30 KT WITH
LIGHTER WINDS NORTHERN WATERS AROUND 10 TO 15 KTS. SEAS WILL BE 8
TO 10 FEET SOUTHERN WATERS TO AND SEAS 3 TO 5 FT OVR NRN WTRS.
THE STRONG ONSHORE FLOW WILL KEEP SURF ROUGH OVER BEACHES FROM HAT
S. ANA OR ITS REMNANTS WILL LIFT NNE TONIGHT INLAND FROM THE
COAST. WINDS WILL DIMINISH A BIT SRN TIER AS ANA WEAKENS...HOWEVER
SPEEDS SHLD INCREASE ACROSS CNTRL AND NRN TIER TO THE E OF THE
CIRC...HAVE STARTED SCA FOR PAMLICO SOUND AND NRN CSTL WTRS LATER
THIS EVENING. SEAS WILL SUBSIDE TO 7 TO 9 FEET S OVERNIGHT AND
BUILD TO 5 TO 7 FEET FAR N.
LONG TERM /MON THROUGH THURSDAY/...
AS OF 350 AM SUN...SMALL CRAFT ADVISORY CONDITIONS EXPECTED MONDAY
AS REMNANTS OF TROPICAL STORM ANA MOVE NORTH THROUGH NORTH CAROLINA.
DEPENDING ON HOW DEEP THE LOW GETS...MAY SEE GALE CONDITIONS
REALIZED DURING THE DAY. SEAS EXPECTED TO BE 8 TO 10 FEET.
CONDITIONS MAY BRIEFLY DROP BELOW SMALL CRAFT ADVISORY CRITERIA
TUESDAY MORNING. HOWEVER AN APPROACHING COLD FRONT WILL TIGHTEN THE
GRADIENT AGAIN FOR SMALL CRAFT POSSIBLE BY LATE TUESDAY. FRONT WILL
MOVE THROUGH THE WATERS WEDNESDAY WITH HIGH PRESSURE BUILDING IN
THROUGH THE REMAINDER OF THE FORECAST PERIOD.
&&
.HYDROLOGY...
FLOOD WATCH ISSUED THROUGH MON MORNING AS BANDS OF HEAVY SHOWERS
PIVOT ACROSS E NC THROUGH TONIGHT. THE HEAVIER SHOWERS WILL
PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. WILL HAVE TO MONITOR
FOR POTENTIAL EXPANSION OF THE FLOOD WATCH FURTHER EAST LATER ON
ACCORDING TO RADAR TRENDS AND MOVEMENT OF REMNANTS OF ANA.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH THROUGH MONDAY MORNING FOR NCZ090>093-095-098.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR AMZ135-150.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF/TL
SHORT TERM...RF
LONG TERM...CCG
AVIATION...CCG/MAC
MARINE...CCG/RF/TL HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1256 AM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1245 AM CDT SUN MAY 10 2015
THE DEVELOPING SPRING STORM REMAINS THE FOCUS THIS MORNING.
RECENT RADAR/SATELLITE IMAGERY AND SURFACE OBSERVATION VALIDATION
INDICATE THAT PRECIPITATION REMAINS UNFROZEN AND GENERALLY
SOUTHEAST OF A LINE FROM AMIDON TO CARRINGTON. UPDATES TO THE QPF
AND SNOW AMOUNTS WERE BASED ON THIS INFORMATION...ALONG WITH WPC
QPF A LITTLE FURTHER SOUTH THROUGH 12 UTC THIS MORNING. WHILE THIS
DOES NOT GREATLY REDUCE SNOWFALL FORECASTS...IT DOES PUSH BACK THE
START OF SNOW ACCUMULATION A FEW HOURS.
UPDATE ISSUED AT 926 PM CDT SAT MAY 9 2015
JUST GETTING A LOOK AT LATEST NAM IN THROUGH 36 HOURS. NOT SEEING
SNOW YET WHERE NAM H850 TEMPS ARE MARGINALLY CLOSE TO SNOW TYPE
ACROSS NORTHWEST SD AND SOUTHWEST ND. LOWER BOUNDARY LAYER TEMPS
STILL TOO WARM AS OF YET. DO THINK THERE WILL BE A CHANGE OVER TO
SNOW AFTER MIDNIGHT SOUTHWEST WHERE H850 TEMP IS CLOSE TO -3 C ON
NAM. STILL A LOT OF UNCERTAINTY OUTSIDE OF THE SOUTHWEST. WILL LET
THE WINTER STORM WATCH BEGIN AT 06Z AS PLANNED NORTH OF WARNING
AREA AND AFTER 12Z NORTH AND EAST OF MISSOURI RIVER.
UPDATE ISSUED AT 701 PM CDT SAT MAY 9 2015
THIS UPDATE WILL MAINLY CONCERN CLOUDS AND WINDS AS PRECIP JUST
MOVING INTO THE REGION AT THIS TIME. WITH A NORTHEAST WIND SOME
EVAPORATION OCCURRING BELOW CLOUD BASE WHICH WILL EVENTUALLY
SATURATE THE LAYERS TONIGHT. UPDATED CURRENT TEMPS...WINDS...AND
CLOUDS. WILL WAIT FOR A NEW RUNS LATER THIS EVENING OF SOME SHORT
RANGE MODELS HRRR FOR FURTHER REFINEMENTS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 311 PM CDT SAT MAY 9 2015
IMPENDING WINTER STORM DOMINATES THE FORECAST HIGHLIGHTS IN THE
SHORT TERM PERIOD. 12Z MODELS IN DECENT AGREEMENT WITH MAIN
FEATURES.
CURRENTLY...DEEP LOW PRESSURE SWINGING EAST ACROSS THE CENTRAL
ROCKIES...WHICH WILL LIFT NORTHEAST INTO THE HIGH PLAINS TONIGHT.
SFC RIDGE OF HIGH PRESSURE STRETCHING FROM LAKE WINNIPEG SOUTHWEST
THROUGH NORTHEASTERN NORTH DAKOTA INTO SOUTHWESTERN ND. EMBEDDED
S/WV IMPULSES CONTINUE TO LIFT NORTH OUT OF THE UPPER LOW ACROSS
THE DAKOTAS...TRIGGERING PRECIPITATION MAINLY ON THE SOUTHERN EDGE
AND ALONG TO EAST OF THE SFC RIDGE AXIS. CLEAR TO PARTLY CLOUDY
ACROSS MY NORTH WITH STRONGER SUBSIDENCE NEAR THE SFC RIDGE.
PRECIPITATION MAINLY IN THE FORM OF RAIN WILL CONTINUE TO DEVELOP
ACROSS MY FAR SOUTH AND SOUTHEASTERN QUARTER NOW INTO THIS
EVENING WHILE DRIER CONDITIONS LINGER WEST AND NORTH. SFC RIDGE
WASHES OUT/LIFTS NORTH THIS EVENING INTO THE OVERNIGHT WITH A SFC
TROUGH DEVELOPING ACROSS EASTERN SOUTH DAKOTA INTO THE JAMES RIVER
BASIN. PRECIPITATION BAND DEVELOPS IN EARNEST ACROSS SOUTH DAKOTA
OVERNIGHT...LIFTING NORTH ACROSS SOUTHWEST AND CENTRAL NORTH
DAKOTA LATE TONIGHT INTO SUNDAY AS THE UPPER LOW LUMBERS NORTH
INTO SOUTH DAKOTA. INHERITED POP GRIDS LOOKED GOOD SO ONLY SOME
MINOR TWEAKS WERE MADE.
SIGNIFICANT SNOWFALL LIKELY WHERE CURRENT WINTER STORM WARNINGS
ARE IN EFFECT. THERMAL PROFILES ARE MORE SUPPORTIVE OF ALL SNOW OR
MAINLY SNOW WEST OF THE MISSOURI RIVER AND ALONG AND SOUTH OF
INTERSTATE 94 WHERE THERE IS VERY NICE MODEL AGREEMENT ON COOLING
925/850MB TEMPS DUE IN PART TO DYNAMIC COOLING AND ALSO MID LEVEL
CAA. STILL LINGERING UNCERTAINTY NORTH AND EAST OF THIS AREA WHERE
TEMPS ALOFT ARE SLIGHTLY WARMER AND THE BIG QUESTION IS EVENTUAL
SFC TEMPERATURES TONIGHT INTO SUNDAY. 2-3 DEGREES WILL HAVE
SIGNIFICANT IMPACTS TO PRECIP TYPE FOR THIS AREA...AND THUS SNOW
ACCUMULATIONS. FOR EXAMPLE...I RAN TWO SCENARIOS FOR BISMARCK ON
TONIGHT THROUGH SUNDAY. THE FIRST WAS A MORE AVERAGE SOLUTION FOR
TEMPERATURES WHERE I GOT 1-3 INCHES OF WET SNOW THROUGH SUNDAY
AFTERNOON (THIS WAS UTILIZED FOR THIS FORECAST PACKAGE). THE
SECOND SCENARIO WAS 2 DEGREES COOLER...WHICH RESULTED IN 6-9
INCHES (THIS WAS NOT USED). OPTED TO UPGRADE MORTON COUNTY TO A
WINTER STORM WARNING BASED ON FORECAST TEMPS ALOFT (AS DISCUSSED
ABOVE). WILL KEEP THE REMAINDER OF THE WATCH AS IS THROUGH SUNDAY
DUE TO THE LINGERING UNCERTAINTY (SEE LONG TERM BELOW FOR WATCH
EXTENSION DISCUSSION).
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 311 PM CDT SAT MAY 9 2015
A STRONG SPRING STORM WILL LINGER THROUGH MONDAY EVENING. THIS
WILL BE THE MAIN FOCUS FOR THE LONG TERM FORECAST.
THE 12 UTC MODELS ARE IN FAIRLY GOOD AGREEMENT WITH RESPECT TO
TIMING AND LOCATION OF THE HEAVIEST PRECIPITATION AND EVOLUTION OF
THE STORM SUNDAY INTO MONDAY. THE 12 UTC GEM AND NAM APPEAR TO BE
ON THE FRINGES WITH THE FORMER LIKELY TOO WET AND TOO FAR TO THE
WEST AND THE LATER TO DRY AND TOO FAR TO THE EAST. FOR THIS
FORECAST UTILIZED A BLEND OF THE GFS/ECMWF/SREF.
THE WINTER STORM WATCH HAS BEEN EXPANDED A LITTLE FURTHER TO THE
EAST AS THERE IS AN INCREASED POTENTIAL FOR ACCUMULATING SNOW
ACROSS PORTIONS OF THE JAMES RIVER VALLEY.
SUNDAY EVENING AND OVERNIGHT...MODERATE TO HEAVY PRECIPITATION IS
EXPECTED TO SPREAD EAST OF THE MISSOURI RIVER AND ALONG I-94 AS A
DEEP SURFACE LOW PROPAGATES ACROSS THE EASTERN DAKOTAS. A
TROWAL...COUPLED WITH STRONG FRONTOGENETIC FORCING WILL LIKELY
PRODUCE HEAVY BANDS OF RAIN/SNOW. AS MUCH AS THREE INCHES OF
LIQUID IS POSSIBLE EAST OF THE MISSOURI RIVER AND ALONG/SOUTH OF
I-94. THE 12 UTC RUNS CONTINUE TO INDICATE H85 TEMPERATURES AROUND
-2C TO -3C AND SURFACE TEMPERATURES HOVERING NEAR FREEZING. THIS
IN TURN COULD LEAD TO ACCUMULATIONS OF HEAVY WET SNOW. AS SUCH
ISSUED A WATCH FOR PORTIONS OF THE JAMES RIVER VALLEY.
HOWEVER...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO
PRECIPITATION TYPE AS A FEW DEGREES DIFFERENCE IN SURFACE
TEMPERATURE COULD MEAN THE DIFFERENCE BETWEEN NO SNOW AND 6+
INCHES. IN ADDITION TO HEAVY PRECIPITATION...THIS POTENT STORM
WILL ALSO PRODUCE STRONG WINDS. AS THE LOW WRAPS UP ACROSS THE
EASTERN DAKOTAS...THE PRESSURE GRADIENT WILL STEEPEN. WINDS AROUND
35 MPH WILL BE LIKELY SUNDAY AND MONDAY. DUE TO THE TIMING (RATHER
LATE IN THE SEASON FOR SNOW) AND POTENTIAL IMPACTS FELT IT WAS
NECESSARY TO ISSUE A WATCH AND GIVE A HEADS UP...BUT CONFIDENCE WAS
NOT HIGH ENOUGH TO WARRANT A MAJOR ALERT.
PRECIPITATION WILL CONTINUE ACROSS MAINLY CENTRAL AND EASTERN
PORTIONS OF NORTH DAKOTA THROUGH MONDAY. NORTHWEST NORTH DAKOTA
MAY GET LEFT HIGH AND DRY. TEMPERATURES ACROSS THE SOUTH AND EAST
WILL STRUGGLE TO GET OUT OF THE 30S AND 40S OVER THE NEXT SEVERAL
DAYS...WHILE THE NORTHWEST MAY REACH THE 50S AND 60S.
THERE WILL BE ADDITIONAL CHANCES FOR RAIN
WEDNESDAY/THURSDAY...WITH A WARM UP EXPECTED LATE WEEK INTO THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1245 AM CDT SUN MAY 10 2015
SIGNIFICANT SPRING SNOW STORM WILL IMPACT SOUTHERN NORTH DAKOTA
BEGINNING TONIGHT. VFR AND MVFR CONDITIONS WILL SLOWLY DETERIORATE
AT KDIK/KBIS/KJMS. CONDITIONS WILL CONTINUE THROUGH SUNDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH THROUGH MONDAY MORNING FOR NDZ020-033-040.
WINTER STORM WARNING UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NDZ034-
041>045.
WINTER STORM WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY
EVENING FOR NDZ022-023-035>037-046-047.
&&
$$
UPDATE...SCHECK
SHORT TERM...NH
LONG TERM...AJ
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS NORMAN OK
655 AM CDT SUN MAY 10 2015
.AVIATION...
CONVECTION THIS MORNING SHOULD MAINLY INFLUENCE OKC/OUN/PNC
THROUGH 15Z. THE RAIN SHOULD ALSO HELP TO IMPROVE IFR CONDITIONS
AT THESE SITES. A COLD FRONT WILL SWEEP ACROSS THE AREA THIS
MORNING INTO TONIGHT. THE FRONT MAY ALSO HELP WITH THE DEVELOPMENT
OF STORMS LATER THIS AFTERNOON...MAINLY AT LAW/OKC/OUN.
OTHERWISE...LOW CEILINGS AND FOG AT CSM/GAG/WWR SHOULD IMPROVE
BY 14Z.
&&
.PREV DISCUSSION... /ISSUED 430 AM CDT SUN MAY 10 2015/
DISCUSSION...
YET ANOTHER ROUND OF CONVECTION IS SET TO MOVE INTO PART OF
WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA OVER THE NEXT SEVERAL
HOURS. THE HRRR HAS BEEN FAIRLY CONSISTENT IN MOVING THIS COMPLEX
ACROSS AREAS SOUTH AND EAST OF I-44 THROUGH THE MID TO LATE
MORNING...WITH ADDITIONAL STORMS IN SOUTHEAST OKLAHOMA THIS
AFTERNOON. MOST MEDIUM RANGE MODELS ARE SIMILAR WITH THE
HRRR...BUT CONTINUE CONVECTION OVER SOUTH CENTRAL AND SOUTHEAST
OKLAHOMA INTO THE AFTERNOON/EVENING. AREAS ALONG AND SOUTHEAST OF
SEMINOLE...PAULS VALLEY AND HENRIETTA...TEXAS MAY SEE ANOTHER 2 TO
4 INCHES OF RAIN THROUGH THE AFTERNOON/EVENING WHICH WILL RESULT
IN SIGNIFICANT FLASH FLOODING. THE MAIN HAZARDS WITH THE MORNING
CONVECTION WILL BE LARGE HAIL...AND FLOODING RAINFALL.
DEPENDING ON HOW MUCH CONVECTION LINGERS OVER SOUTHEAST
OKLAHOMA...ADDITIONAL THUNDERSTORMS MAY DEVELOP ACROSS NORTH
CENTRAL...CENTRAL AND SOUTHWEST OKLAHOMA AS A COLD FRONT
APPROACHES...SIMILAR TO THE 06Z NAM. INSTABILITY AND SHEAR WILL
SUPPORT THE RISK OF VERY LARGE HAIL AND DAMAGING WINDS.
A COLD FRONT WILL SWEEP ACROSS ALL OF OKLAHOMA AND WESTERN
NORTH TEXAS BY EARLY MONDAY...WHICH WILL BRING A MUCH NEEDED
BREAK FROM SEVERE STORMS AND FLOODING RAIN. ANOTHER SHORT WAVE
TROUGH IS FORECAST TO LIFT ACROSS THE CENTRAL PLAINS ON
WEDNESDAY...WITH ANOTHER ACTIVE SOUTHWEST FLOW PERIOD FROM FRIDAY
INTO NEXT WEEKEND.
FOR NOW...WILL LEAVE THE FLOOD WATCH THE SAME...BUT SHOULD BE
ABLE TO REMOVE NORTHWEST PARTS OF THE WATCH LATER THIS AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 76 51 70 50 / 60 40 0 0
HOBART OK 78 49 70 48 / 20 10 0 0
WICHITA FALLS TX 78 55 72 51 / 70 20 10 0
GAGE OK 74 43 68 43 / 0 10 0 0
PONCA CITY OK 77 48 69 45 / 50 40 0 0
DURANT OK 76 60 75 54 / 90 80 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLOOD WATCH THROUGH MONDAY MORNING FOR OKZ006>008-011>013-
015>048-050>052.
TX...FLOOD WATCH THROUGH MONDAY MORNING FOR TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
430 AM CDT SUN MAY 10 2015
.DISCUSSION...
YET ANOTHER ROUND OF CONVECTION IS SET TO MOVE INTO PART OF
WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA OVER THE NEXT SEVERAL
HOURS. THE HRRR HAS BEEN FAIRLY CONSISTENT IN MOVING THIS COMPLEX
ACROSS AREAS SOUTH AND EAST OF I-44 THROUGH THE MID TO LATE
MORNING...WITH ADDITIONAL STORMS IN SOUTHEAST OKLAHOMA THIS
AFTERNOON. MOST MEDIUM RANGE MODELS ARE SIMILAR WITH THE
HRRR...BUT CONTINUE CONVECTION OVER SOUTH CENTRAL AND SOUTHEAST
OKLAHOMA INTO THE AFTERNOON/EVENING. AREAS ALONG AND SOUTHEAST OF
SEMINOLE...PAULS VALLEY AND HENRIETTA...TEXAS MAY SEE ANOTHER 2 TO
4 INCHES OF RAIN THROUGH THE AFTERNOON/EVENING WHICH WILL RESULT
IN SIGNIFICANT FLASH FLOODING. THE MAIN HAZARDS WITH THE MORNING
CONVECTION WILL BE LARGE HAIL...AND FLOODING RAINFALL.
DEPENDING ON HOW MUCH CONVECTION LINGERS OVER SOUTHEAST
OKLAHOMA...ADDITIONAL THUNDERSTORMS MAY DEVELOP ACROSS NORTH
CENTRAL...CENTRAL AND SOUTHWEST OKLAHOMA AS A COLD FRONT
APPROACHES...SIMILAR TO THE 06Z NAM. INSTABILITY AND SHEAR WILL
SUPPORT THE RISK OF VERY LARGE HAIL AND DAMAGING WINDS.
A COLD FRONT WILL SWEEP ACROSS ALL OF OKLAHOMA AND WESTERN
NORTH TEXAS BY EARLY MONDAY...WHICH WILL BRING A MUCH NEEDED
BREAK FROM SEVERE STORMS AND FLOODING RAIN. ANOTHER SHORT WAVE
TROUGH IS FORECAST TO LIFT ACROSS THE CENTRAL PLAINS ON
WEDNESDAY...WITH ANOTHER ACTIVE SOUTHWEST FLOW PERIOD FROM FRIDAY
INTO NEXT WEEKEND.
FOR NOW...WILL LEAVE THE FLOOD WATCH THE SAME...BUT SHOULD BE
ABLE TO REMOVE NORTHWEST PARTS OF THE WATCH LATER THIS AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 76 51 70 50 / 60 40 0 0
HOBART OK 78 49 70 48 / 20 10 0 0
WICHITA FALLS TX 78 55 72 51 / 70 20 10 0
GAGE OK 74 43 68 43 / 0 10 0 0
PONCA CITY OK 77 48 69 45 / 50 40 0 0
DURANT OK 76 60 75 54 / 90 80 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLOOD WATCH THROUGH MONDAY MORNING FOR OKZ006>008-011>013-
015>048-050>052.
TX...FLOOD WATCH THROUGH MONDAY MORNING FOR TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
226 PM PDT SUN MAY 10 2015
.DISCUSSION...CURRENT VISIBLE IMAGE SHOWS CUMULUS ALREADY STARTING
TO BUILD UP ALONG THE CASCADES AND FROM THE SCOTT VALLEY TO THE
TRINITY ALPS AND AND SISKIYOUS IN NORTHERN CAL AND ARE MOVING
NORTHEAST. THE PAST SEVERAL RUNS OF THE HRRR MODEL (WHICH IS UPDATED
HOURLY) CONTINUES TO SHOW SOME CONVECTIVE SHOWERS IN THE ABOVE
MENTION AREAS IN ADDITION TO SOUTH THROUGH EASTERN JACKSON COUNTY
AND NORTHERN KLAMATH COUNTY. THE MODELS SUGGEST THERE`S ENOUGH
INSTABILITY FOR ISOLATED THUNDERSTORMS LATE THIS AFTERNOON INTO THIS
EVENING. THE 700 MB WINDS ARE FROM THE SOUTHWEST, SO SHOWERS AND
ISOLATED STORMS THAT DEVELOP WILL GENERALLY MOVE NORTHEAST. ISOLATED
STORMS WILL END THIS EVENING AS WE LOSE DAYTIME HEATING, BUT
INSTABILITY SHOWERS WILL CONTINUE OVERNIGHT AS THE UPPER TROUGH
CURRENTLY NEAR 45N/130W DIGS SOUTH TOWARDS THE OREGON COAST.
THE UPPER TROUGH WILL EVOLVE INTO AN UPPER LOW AND THIS WILL BE
RESPONSIBLE FOR BRINGING MUCH COOLER TEMPERATURES...SCATTERED
SHOWERS JUST ABOUT ANYWHERE IN THE FORECAST AREA MONDAY AND TUESDAY.
IN ADDITION, ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF
THE CASCADES BOTH MONDAY AND TUESDAY AFTERNOON AND EARLY EVENING.
THE UPPER TROUGH WILL DIG SOUTH AND BECOME AND UPPER LOW MONDAY...
REACH THE OREGON COAST MONDAY AFTERNOON, THEN MOVE OVER THE AREA
MONDAY NIGHT INTO TUESDAY. THE MODELS HAVE COME INTO BETTER AGREEMENT
WITH THE PLACEMENT OF THE UPPER LOW WHICH YIELDS HIGHER CONFIDENCE
WE`LL BE COOL AND WET FOR THE START OF NEXT WEEK. THE MODELS ALSO
SHOW THE GREATEST INSTABILITY ALONG AND EAST OF THE CASCADES AND
PLENTY OF SHORTWAVES WILL MOVE OUT AHEAD OF THE UPPER LOW MONDAY
PROVIDING THE TRIGGER FOR ISOLATED STORMS TO FIRE UP.
THE UPPER LOW WILL MOVE OVERHEAD ON TUESDAY BRINGING COLD AIR ALOFT
WITH 500 MB TEMPERATURES BETWEEN -25 AND -28C. SHOWERS WILL OCCUR
JUST ABOUT ANYWHERE TUESDAY WITH SOME MODERATE TO HEAVY IN THE
AFTERNOON AS WE REACH MAX HEATING. SNOW LEVELS TUESDAY ARE EXPECTED
TO BE AROUND 5000 FEET, BUT WILL TEMPORARILY LOWER IN HEAVIER
SHOWERS. RIGHT NOW, WERE ONLY EXPECTING SNOW TO ACCUMULATE OVER THE
HIGHER TERRAIN ALONG AND EAST OF THE CASCADES. ISOLATED
THUNDERSTORMS REMAIN A CONCERN TUESDAY AFTERNOON ALONG AND EAST OF
THE CASCADES.
SHOWERS ARE EXPECTED TO GRADUALLY DECREASE TUESDAY NIGHT AS THE
UPPER LOW WEAKENS AND MOVES NORTH. HOWEVER THE NAM SHOW ANOTHER
SHORTWAVE ON THE HEALS OF THE UPPER TROUGH AND WE COULD SEE SHOWERS
INCREASE AGAIN EARLY WEDNESDAY MORNING. THE GFS IS SLOWER WITH THE
NEXT SHORTWAVE AND EC IS ALSO SLOWER AND WEAKER. EITHER ONE OF THESE
SOLUTIONS WILL RESULT IN A COOL AND UNSETTLED PATTERN ON WEDNESDAY.
-PETRUCELLI
&&
.AVIATION...FOR THE 10/18Z TAF CYCLE...A LOW PRESSURE SYSTEM
WILL BRING SOME ISOLATED THUNDERSTORMS AND SHOWERS OVER INLAND AREAS
THROUGH THIS EVENING...THEN EXPECT SHOWERS TO MOVE INLAND OVER THE
AREA TONIGHT AND MONDAY MORNING ALONG THE COAST...VFR CONDITIONS
WILL CONTINUE THIS AFTERNOON...THEN MVFR CIGS ARE EXPECTED TO
DEVELOP AROUND 00Z AND PERSIST THROUGH THE EVENING. OVERNIGHT
THROUGH MONDAY MORNING...EXPECT A MIX OF VFR/MVFR CIGS ALONG THE
COAST. INLAND...VFR CONDITIONS WILL CONTINUE THROUGH THIS EVENING.
HOWEVER ISOLATED THUNDERSTORMS ARE EXPECTED ALONG FROM THE SISKIYOUS
AND WESTERN SLOPES OF THE CASCADES AND EASTWARD LATE THIS AFTERNOON
AND THIS EVENING. THIS MAY BRING SOME ISOLATED MVFR CIGS TO THESE
AREAS ALONG WITH VARIABLE AND GUSTY WINDS. THEN AS SHOWERS MOVE
INLAND OVERNIGHT, EXPECT WIDESPREAD MVFR CIGS LATE THIS EVENING INTO
TONIGHT...CONTINUING INTO MONDAY MORNING. WIDESPREAD MOUNTAIN
OBSCURATIONS ARE ALSO EXPECTED LATE THIS EVENING THROUGH MONDAY
MORNING. /CC
&&
.MARINE...UPDATED 145 PM PDT SUNDAY, MAY 10, 2015...A DRY COLD FRONT
MOVING THROUGH THE WATERS THIS AFTERNOON WILL CAUSE NORTH WINDS TO
INCREASE THROUGH EARLY MONDAY. THESE INCREASING NORTH WINDS WILL
RESULT IN STEEP SEAS FOR MOST OF THE WATERS BEYOND 10 MILES OF THE
COAST AND INNER WATERS SOUTH OF PORT ORFORD. THESE SMALL CRAFT
ADVISORY CONDITIONS ARE EXPECTED TO LINGER THROUGH MONDAY NIGHT.
SHOWERS ARE EXPECTED MONDAY EVENING THROUGH WEDNESDAY. WINDS AND
SEAS WILL DIMINISH ON TUESDAY AND ARE LIKELY REMAIN BELOW ADVISORY
LEVELS THROUGH THURSDAY. -SCHAAF
.FIRE WEATHER...UPDATED 100 PM PDT SUNDAY, MAY 10, 2015...A WEAK
COLD FRONT WILL PERSIST OVER THE AREA THIS AFTERNOON AND EVENING
ALLOWING SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP FROM ABOUT
THE SHASTA AND SCOTT VALLEYS NORTHWARD TO THE SISKIYOUS AND INTO THE
CASCADES THIS AFTERNOON. STORMS ARE ALSO POSSIBLE ALONG THE WESTERN
SLOPES OF THE CASCADES AND INTO PORTIONS OF THE ROGUE VALLEY LATE
THIS AFTERNOON. THEN THIS EVENING...EXPECT ISOLATED THUNDERSTORMS
FROM THE CASCADES EASTWARD. MID-LEVEL SOUTHWEST FLOW WITH NORTHWEST
FLOW IN THE LOWER LEVELS WILL CAUSE WINDS AND MOISTURE TO CONVERGE
IN THESE AREAS AND MODELS CONTINUE TO SHOW INSTABILITY WITH THE
POTENTIAL FOR ISOLATED THUNDERSTORMS. STORMS SHOULD GENERALLY
PRODUCE RAINFALL, THOUGH AMOUNTS ARE LIKELY TO BE LIGHT TO MODERATE
AT 0.10" TO 0.25" OR LESS. STORMS ARE EXPECTED TO MOVE FROM
SOUTHWEST TO NORTHEAST AT 10-20 KNOTS. THE STORMS WILL CAPABLE OF
GUSTY OUTFLOW WINDS OF 25 TO 35 MPH AND SMALL HAIL. GUSTY WEST TO
SOUTHWEST WINDS ARE EXPECTED AHEAD OF THE FRONT OVER THE EAST SIDE
THIS AFTERNOON, WITH GUSTY NORTHWEST WINDS BEHIND IT ON THE WEST
SIDE.
SCATTERED SHOWERS ACROSS THE AREA TONIGHT WILL INCREASE IN COVERAGE
AND INTENSITY MONDAY MORNING THROUGH MONDAY EVENING AS AN UPPER LOW
MOVES INTO THE COAST. ISOLATED THUNDERSTORMS MIXED WITH SHOWERS
ARE EXPECTED ON THE EAST SIDE MONDAY AFTERNOON AND EVENING,
PRIMARILY FOR EASTERN SISKIYOU, MODOC, EASTERN KLAMATH AND LAKE
COUNTIES. THEN SHOWERS AND ISOLATED THUNDERSTORMS ARE LIKELY OVER
MUCH OF THE AREA ON TUESDAY AS THE UPPER LEVEL LOW MOVES OVERHEAD.
/CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING
TO 11 PM PDT MONDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 2 AM TO 11 PM PDT MONDAY FOR
PZZ376.
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
921 AM PDT SUN MAY 10 2015
.DISCUSSION...MADE A FEW ADJUSTMENTS TO THE FORECAST FOR TODAY.
CURRENT VISIBLE IMAGE SHOWS A CIRRUS SHIELD MOVING OVER THE
REGION THIS MORNING WHICH WILL INITIALLY LIMIT THE AMOUNT OF
SURFACE HEATING, BUT THIS WILL MOVE EAST LATE THIS MORNING. WHAT
MAY HAPPEN IS ISOLATED STORMS WILL BE DELAYED UNTIL LATE THIS
AFTERNOON. THE CIRRUS SHIELD IS THINNER IN SISKIYOU COUNTY, SO IT
WILL HAVE LITTLE OR NO EFFECT ON SURFACE HEATING THERE AND
ISOLATED STORMS COULD DEVELOP THERE EARLY THIS AFTERNOON. ALSO THE
LATEST HRRR MODEL SHOWS CONVECTIVE SHOWERS BREAKING OUT FURTHER
WEST INTO PARTS OF JACKSON COUNTY LATE THIS AFTERNOON AND HAVE
EXPANDED THE MENTION OF ISOLATED THUNDER. THE FLOW AT 700 MB WILL
BE FROM THE SOUTHWEST, SO SHOWERS AND ISOLATED STORMS THAT DEVELOP
WILL MOVE NORTHEAST.
IN ADDITION SHOWERS AND ISOLATED STORMS THAT DEVELOP ALONG THE
CASCADES WILL TEND TO MOVE NORTHEAST INTO NORTHERN KLAMATH COUNTY
AND HAVE EXPANDED THE COVERAGE TO INCLUDE THIS AREA.
KEEP IN MIND, MOST HOURS AND LOCATIONS WILL HAVE CONVECTIVE
SHOWERS, BUT CONDITIONS ARE FAVORABLE FOR ISOLATED THUNDERSTORMS
LATE THIS AFTERNOON AND EVENING. -PETRUCELLI
&&
.AVIATION...IFR AND MVFR CIGS WILL GRADUALLY LIFT TO VFR LATE THIS
MORNING AND WILL CONTINUE INTO THIS AFTERNOON. THE MAIN CONCERN
WILL BE THE POTENTIAL FOR ISOLATED THUNDERSTORMS FROM ABOUT THE
SCOTT VALLEY, SISKIYOUS, AND CASCADES THIS AFTERNOON, SPREADING
NORTHEASTWARD ACROSS THE EAST SIDE DURING THE EVENING. THESE
STORMS WILL BE CAPABLE OF GUSTY OUTFLOW WINDS, ESPECIALLY THIS
AFTERNOON, AS WELL AS BRIEF MVFR TO IFR DOWNPOURS AND SMALL HAIL.
AREAS AROUND KMFR COULD BE AFFECTED BY THUNDERSTORMS BETWEEN 00Z
AND 03Z. THIS EVENING AND OVERNIGHT MVFR AND SHOWERS ARE EXPECTED
ACROSS THE INTERIOR WEST SIDE. -PETRUCELLI
&&
.MARINE...UPDATED 230 AM PDT SUNDAY, MAY 10, 2015...A MOSTLY DRY
COLD FRONT MOVING THROUGH THIS AFTERNOON WILL CAUSE NORTH WINDS TO
INCREASE THROUGH EARLY MONDAY. THESE INCREASING NORTH WINDS WILL
RESULT IN SMALL CRAFT ADVISORY CONDITIONS FOR MUCH OF THE AREA SOUTH
AND WEST OF CAPE BLANCO TONIGHT THROUGH MONDAY NIGHT...PRIMARILY FOR
STEEP SEAS. SHOWERS ARE EXPECTED LATE MONDAY NIGHT THROUGH
WEDNESDAY. WINDS AND SEAS WILL DIMINISH ON TUESDAY AND ARE LIKELY
REMAIN BELOW ADVISORY LEVELS THROUGH THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 640 AM PDT SUN MAY 10 2015/
DISCUSSION...A COLD FRONT IS ON TRACK TO MOVE ASHORE THIS MORNING
AND CROSSES THE CASCADES INTO THE KLAMATH BASIN BY EARLY THIS
AFTERNOON. HIGHS TODAY WILL BE ABOUT 5 DEGREES COOLER WEST OF THE
CASCADES...WHILE TEMPERATURES EAST OF THE CASCADES ARE NOT
EXPECTED TO BE MUCH DIFFERENT THAN YESTERDAY. MODELS SUGGEST
ENOUGH INSTABILITY EXIST TO WARRANT A SLIGHT CHANCE OF
THUNDERSTORMS ALONG THE CASCADES AND FROM ABOUT THE SCOTT VALLEY
TO THE TRINITY ALPS AND SISKIYOUS IN NORTHERN CAL. PRECIPITABLE
WATER WILL ALSO BE INCREASING AND COMING UP FROM THE SACRAMENTO
VALLEY INTO THE SHASTA VALLEY. IT`S POSSIBLE THAT ANY STORM THAT
DEVELOP WILL PRODUCE RAINFALL. THE AREA OF INSTABILITY WILL
CONTINUE TO SHIFT EAST THIS EVENING WITH THUNDERSTORM POTENTIAL
EXPANDING INTO THE WARNER MOUNTAINS.
THE UPPER LEVEL TROUGH WILL DIG SOUTH WITH THE CLOSED LOW COMING
INLAND NEAR REEDSPORT MONDAY AFTERNOON. THE LOW PRESSURE IS
EXPECTED TO MOVE OVER THE SOUTHERN OREGON MONDAY NIGHT INTO
TUESDAY PER THE GFS SOLUTION, WITH THE ECMWF KEEPING THE LOW
OVER THE GOOSE LAKE AREA. IN BOTH SOLUTIONS THERE IS PLENTY OF
COLD AIR ALOFT THAT WILL HELP TO DESTABILIZE THE ATMOSPHERE. THIS
IN COMBINATION WITH DAYTIME HEATING WILL RESULT IN MORE
WIDESPREAD SHOWERS. THE MODELS SHOW THE GREATEST INSTABILITY ALONG
AND EAST OF THE CASCADES WITH DIVERGENCE ALOFT, SO HAVE MODERATE
CONFIDENCE FOR THUNDERSTORMS IN THIS AREA, ESPECIALLY GIVEN THAT
500MB TEMPERATURES WILL BE BETWEEN -25 AND -28C. SHOWERS WILL
OCCUR JUST ABOUT ANYWHERE TUESDAY WITH SOME MODERATE TO HEAVY IN
THE AFTERNOON AS WE REACH MAX HEATING. SNOW LEVELS TUESDAY ARE
EXPECTED TO BE AROUND 5000 FEET, BUT WILL TEMPORARILY LOWER IN
HEAVIER SHOWERS. RIGHT NOW, WERE ONLY EXPECTING SNOW TO ACCUMULATE
OVER THE HIGHER TERRAIN ALONG AND EAST OF THE CASCADES. MEANWHILE
THERE`S STILL A CHANCE FOR THUNDERSTORMS ALONG AND EAST OF THE
CASCADES. SHOWERS WILL GRADUALLY DECREASE TUESDAY NIGHT AS THE
UPPER LOW MOVES AWAY AS WE LOSE DAYTIME HEATING. /FB
FIRE WEATHER...UPDATED 600 AM PDT SUNDAY, MAY 10, 2015...A COLD
FRONT WILL DEVELOP OVER THE AREA TODAY GIVING RISE TO SHOWERS AND
ISOLATED THUNDERSTORMS FROM ABOUT THE SCOTT VALLEY, SISKIYOUS, AND
CASCADES EASTWARD. THE BEST POSSIBILITY FOR THUNDERSTORMS TODAY
APPEARS TO BE FROM ABOUT THE NORTHEASTERN TRINITY ALPS AND THE
EASTERN SCOTT AND SHASTA VALLEYS NORTH-NORTHEASTWARD INTO AREAS OF
KLAMATH COUNTY FROM THE CASCADE CREST EASTWARD. MID-LEVEL SOUTHWEST
FLOW WITH NORTHWEST FLOW IN THE LOWER LEVELS WILL CAUSE WINDS AND
MOISTURE TO CONVERGE IN THESE AREAS, WHERE PRECIPITABLE WATER VALUES
OF 0.50" TO 0.75" ARE EXPECTED AND MODEL LIFTED INDICES AREA MOSTLY
IN THE -2C TO -4C RANGE. THIS MEANS STORMS SHOULD GENERALLY PRODUCE
RAINFALL, THOUGH AMOUNTS ARE LIKELY TO BE LIGHT TO MODERATE AT 0.10"
TO 0.25" OR LESS. STORMS ARE EXPECTED TO MOVE FROM SOUTHWEST TO
NORTHEAST AT 15-20 KNOTS. THE STORMS WILL CAPABLE OF GUSTY OUTFLOW
WINDS OF 25 TO 35 MPH AND SMALL HAIL. GUSTY SOUTHWEST WINDS ARE
EXPECTED AHEAD OF THE FRONT OVER THE EAST SIDE THIS AFTERNOON, WITH
GUSTY NORTHWEST WINDS BEHIND IT ON THE WEST SIDE. SCATTERED SHOWERS
ACROSS THE AREA TONIGHT WILL INCREASE IN COVERAGE AND INTENSITY
MONDAY AFTERNOON AND EVENING UNDER A GENERAL WEST FLOW. ISOLATED
THUNDERSTORMS ARE EXPECTED ON THE EAST SIDE MONDAY AFTERNOON AND
EVENING, PRIMARILY EAST OF THE CASCADES. SHOWERS AND THUNDERSTORMS
ARE LIKELY OVER MUCH OF THE AREA ON TUESDAY AS THE UPPER LEVEL LOW
MOVES OVERHEAD. BTL
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 11 PM THIS EVENING
TO 11 PM PDT MONDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 2 AM TO 11 PM PDT MONDAY FOR
PZZ376.
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
306 AM EDT SUN MAY 10 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST
CONUS THROUGH MONDAY. SUMMER LIKE WEATHER WILL BE ENJOYED BY
MOST...EXCEPT FOR A MOIST MARITIME FLOW BRINGING PERIODS OF LOW
CLOUDS AND FOG TO PORTIONS OF THE LOWER TO MIDDLE SUSQUEHANNA
RIVER VALLEY THROUGH SUNDAY. A SHARP COLD FRONT WILL CROSS THE
AREA EARLY TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM
BUILDING SOUTHEAST INTO PA THE LATER HALF OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
SCT RING OF FIRE CONVECTION CONTINUES TO FIRE WITHIN PLUME OF
ANOMALOUS PWATS ON NW PERIPHERY OF UPPER RIDGE FROM THE MISS
VALLEY INTO NW PA. EXPECT SHOWERS TO DWINDLE OVR WARREN CO EARLY
THIS MORNING...AS BLYR COOLS/STABILIZES. LATEST HRRR SUPPORTS THIS
IDEA WITH SHOWERS TAPERING OFF BTWN 06Z-09Z.
ACROSS THE SE HALF OF THE STATE...FOCUS WILL BE ON MARINE STRATUS
ADVECTING WESTWARD INTO THE AREA TOWARD DAWN. LATEST SREF AND HRRR
OUTPUT SUPPORT THE STRATUS REACHING TO ABOUT THE SUSQ RIVER.
UNCERTAIN IF STRATUS WILL REACH FURTHER WEST INTO THE
RIDGE/VALLEY REGION...BUT IF IT DOESN/T PATCHY RADIATION FOG
APPEARS LIKELY FROM KAOO THRU KUNV AND KIPT. HAVE REMOVED MENTION
OF DZ ACROSS THE EASTERN COUNTIES...WHERE MDL SOUNDINGS INDICATE
DEPTH OF MOISTURE WILL REMAIN TOO SHALLOW TO SUPPORT ANY PRECIP.
TEMPS ON TRACK TO BOTTOM OUT THIS MORNING IN THE L60S MOST SPOTS.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM MONDAY/...
AM LOW CLOUDS/FOG SHOULD ONCE AGAIN MIX OUT BY LATE AM...WITH
AREAS EAST OF KMDT SEEING THE MOST PERSISTENT CLOUD COVER. ENS
MEAN 8H TEMPS SUPPORTIVE OF MAX TEMPS IN THE LOW TO MID 80S.
WARM MID LVL TEMPS ARE LIKELY TO ONCE AGAIN SUPPRESS CONVECTION
OVER MOST OF CENTRAL/SOUTHERN PA. HOWEVER...GEFS/SREF OUTPUT
SUPPORTS A DECENT CHANCE OF PM TSRA ACROSS THE NW MTNS ON NORTHERN
PERIPHERY OF UPPER RIDGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
DID NOT CHANGE MUCH FOR SUNDAY NIGHT INTO TUE. HARD TO SEE MUCH
GOING ON BEFORE MONDAY NIGHT...WHEN THE COLD FRONT MOVES INTO THE
AREA. DID UP TEMPS A LITTLE HERE AND THERE. DID CUT BACK ON POPS
SOME.
WEAK UPPER LEVEL SYSTEM LIFTING NE SUNDAY NIGHT COULD TOUCH OFF
A SHOWER OR STORM.
LACK OF SFC COVERGENCE...HEIGHT FALLS...AND TIMING OF THE COLD
FRONT FOR TUE...HARD TO SEE A LOT OF WIDESPREAD SEVERE STORMS.
STILL HAVE TO WATCH ANY MOISTURE WORKING INTO SE PA FROM
TS ANA.
RATHER STRONG MID LEVEL WIND FIELDS FOR WED. IT WILL BE BREEZY
AND COOL...WITH SOME CLDS AND PERHAPS A SHOWER TO THE NORTH.
MORE DETAIL BELOW.
THE FLOW ALOFT WILL TRANSITION TO A TROUGHING PATTERN BY WED.
CHILLY TEMPS ALOFT WILL LIKELY LEAD TO PLENTY OF STRATOCU/CU
ACROSS THE AREA WED...WITH A SHRA EVEN POSSIBLE ACROSS THE N MTNS
W/PASSAGE OF UPPER TROF AXIS. LOOK FOR TEMPERATURES TO DROP TO
NEAR/BELOW NORMAL WED-THU WITH A COUPLE OF VERY CHILLY MORNINGS
THU/FRI...AS SFC HIGH BUILDS OVR THE AREA. MAY HAVE TO CONTEND
W/POSSIBLE FROST OVR THE NW MTNS THOSE MORNINGS WITH MINS LKLY IN
THE 30S. GROWING SEASON STARTS MAY 11 OVER PARTS OF THE ALLEGHENY
MTNS. CONFIDENCE IN NEAR-FREEZING TEMPS IS HIGHEST IN
MCKEAN/POTTER AND ELK BUT THE GROWING SEASON DOES NOT BEGIN IN
THESE COUNTIES UNTIL MAY 21.
WENT WITH A DRY FCST FOR THU INTO SAT...AS THE UPPER LVL RIDGE
STARTS TO BUILD ACROSS THE EAST AGAIN.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
EARLY THIS OVERNIGHT IN THE NW MTNS...A CLUSTER OF SHOWERS/TSTMS
WILL SLIP BETWEEN KERI-KBFD...IMPACTING KJHW BUT MISSING KBFD. BY
09Z...THIS AREA OF SHOWERS WILL BE QUICKLY DIMINISHING.
MARINE STRATUS/FOG WILL AGAIN WORK IN FROM THE SE. IFR CONDITIONS
HAVE ALREADY REACHED KLNS...AND WILL CONTINUE TO EDGE FURTHER
NORTH/WEST TOWARD THE CENTRAL MTNS MAINLY AFTER 08Z. OVERALL
EXTEND WILL LIKELY BE LARGER THAN LAST NIGHT...POSSIBLY ALL THE
WAY TO KAOO-KUNV-KIPT. THESE REDUCTIONS WILL CLEAR BY MID/LATE
MORNING WITH KMDT-KLNS HOLDING ON TO RESTRICTIONS THE LONGEST.
UPPER RIDGE REMAINS OVER THE REGION SUNDAY. WITH LOW LEVEL
MOISTURE INCREASING...POSS OF CONVECTION WILL BE A BIT HIGHER THAN
SAT. BEST CHANCES WILL BE IN THE NW MTNS...WITH LOW PROBS IN THE
LAURELS AND SE. OVERALL PROBS TOO LOW TO MENTION IN TAFS OUTSIDE
OF KBFD.
OUTLOOK...
MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS
POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE.
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...FITZGERALD/GARTNER/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
156 AM EDT SUN MAY 10 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST
CONUS THROUGH MONDAY. SUMMER LIKE WEATHER WILL BE ENJOYED BY
MOST...EXCEPT FOR A MOIST MARITIME FLOW BRINGING PERIODS OF LOW
CLOUDS AND FOG TO PORTIONS OF THE LOWER TO MIDDLE SUSQUEHANNA
RIVER VALLEY THROUGH SUNDAY. A SHARP COLD FRONT WILL CROSS THE
AREA EARLY TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM
BUILDING SOUTHEAST INTO PA THE LATER HALF OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
SCT RING OF FIRE CONVECTION CONTINUES TO FIRE WITHIN PLUME OF
ANOMALOUS PWATS ON NW PERIPHERY OF UPPER RIDGE FROM THE MISS
VALLEY INTO NW PA. EXPECT SHOWERS TO DWINDLE OVR WARREN CO EARLY
THIS MORNING...AS BLYR COOLS/STABILIZES. LATEST HRRR SUPPORTS THIS
IDEA WITH SHOWERS TAPERING OFF BTWN 06Z-09Z.
ACROSS THE SE HALF OF THE STATE...FOCUS WILL BE ON MARINE STRATUS
ADVECTING WESTWARD INTO THE AREA TOWARD DAWN. LATEST SREF AND HRRR
OUTPUT SUPPORT THE STRATUS REACHING TO ABOUT THE SUSQ RIVER.
UNCERTAIN IF STRATUS WILL REACH FURTHER WEST INTO THE
RIDGE/VALLEY REGION...BUT IF IT DOESN/T PATCHY RADIATION FOG
APPEARS LIKELY FROM KAOO THRU KUNV AND KIPT. HAVE REMOVED MENTION
OF DZ ACROSS THE EASTERN COUNTIES...WHERE MDL SOUNDINGS INDICATE
DEPTH OF MOISTURE WILL REMAIN TOO SHALLOW TO SUPPORT ANY PRECIP.
TEMPS ON TRACK TO BOTTOM OUT THIS MORNING IN THE L60S MOST SPOTS.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM MONDAY/...
AM LOW CLOUDS/FOG SHOULD ONCE AGAIN MIX OUT BY LATE AM...WITH
AREAS EAST OF KMDT SEEING THE MOST PERSISTENT CLOUD COVER. ENS
MEAN 8H TEMPS SUPPORTIVE OF MAX TEMPS IN THE LOW TO MID 80S.
WARM MID LVL TEMPS ARE LIKELY TO ONCE AGAIN SUPPRESS CONVECTION
OVER MOST OF CENTRAL/SOUTHERN PA. HOWEVER...GEFS/SREF OUTPUT
SUPPORTS A DECENT CHANCE OF PM TSRA ACROSS THE NW MTNS ON NORTHERN
PERIPHERY OF UPPER RIDGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
RESENT TO ADD SATURDAY TO HEADER ON LINE ABOVE.
DID NOT CHANGE MUCH FOR SUNDAY NIGHT INTO TUE. HARD TO SEE
MUCH GOING ON BEFORE MONDAY NIGHT...WHEN THE COLD FRONT MOVES
INTO THE AREA. DID UP TEMPS A LITTLE HERE AND THERE. DID CUT BACK
ON POPS SOME.
WEAK UPPER LEVEL SYSTEM LIFTING NE SUNDAY NIGHT COULD TOUCH OFF
A SHOWER OR STORM.
LACK OF SFC COVERGENCE...HEIGHT FALLS...AND TIMING OF THE COLD
FRONT FOR TUE...HARD TO SEE A LOT OF WIDESPREAD SEVERE STORMS.
STILL HAVE TO WATCH ANY MOISTURE WORKING INTO SE PA FROM
TS ANA.
RATHER STRONG MID LEVEL WIND FIELDS FOR WED. IT WILL BE BREEZY
AND COOL...WITH SOME CLDS AND PERHAPS A SHOWER TO THE NORTH.
MORE DETAIL BELOW.
THE FLOW ALOFT WILL TRANSITION TO A TROUGHING PATTERN BY WED.
CHILLY TEMPS ALOFT WILL LIKELY LEAD TO PLENTY OF STRATOCU/CU
ACROSS THE AREA WED...WITH A SHRA EVEN POSSIBLE ACROSS THE N MTNS
W/PASSAGE OF UPPER TROF AXIS. LOOK FOR TEMPERATURES TO DROP TO
NEAR/BELOW NORMAL WED-THU WITH A COUPLE OF VERY CHILLY MORNINGS
THU/FRI...AS SFC HIGH BUILDS OVR THE AREA. MAY HAVE TO CONTEND
W/POSSIBLE FROST OVR THE NW MTNS THOSE MORNINGS WITH MINS LKLY IN
THE 30S. GROWING SEASON STARTS MAY 11 OVER PARTS OF THE ALLEGHENY
MTNS. CONFIDENCE IN NEAR-FREEZING TEMPS IS HIGHEST IN
MCKEAN/POTTER AND ELK BUT THE GROWING SEASON DOES NOT BEGIN IN
THESE COUNTIES UNTIL MAY 21.
WENT WITH A DRY FCST FOR THU INTO SAT...AS THE UPPER LVL RIDGE
STARTS TO BUILD ACROSS THE EAST AGAIN.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE FIRST HALF OF TONIGHT.
STREAMING MOISTURE ALONG A BOUNDARY IS SLOWLY PROGRESSING INTO
THE NW MTNS. THIS WILL BRING SHOWERS AND POSSIBLE MVFR CIGS AND
FOR A SHORT TIME...IFR IS POSSIBLE...TO BFD. TONIGHT WE LIKELY SEE
A REPEAT PERFORMANCE OF THE MARINE STRATUS/FOG WORKING INTO THE SE
COUNTIES - MAINLY AFTER 08Z. LATEST MDL SOUNDINGS/SREF OUTPUT
SUGGESTS THE THREAT OF LOW CLOUDS/FOG WILL EXTEND FURTHER NW THAN
THIS AM...POSSIBLY ALL THE WAY TO KAOO- KUNV-KIPT. HAVE INCLUDED
UNV...BUT HELD OFF ON IPT AND AOO THOUGH MVFR CIGS REMAIN
POSSIBLE. ALL REDUCING CIGS AND VSBYS WILL CLEAR BY LATE MORNING
WITH MDT AND LNS BEING HOLDING ONTO RESTRICTIONS THE LONGEST.
OUTLOOK...
SUN...AM LOW CLOUDS/FOG POSSIBLE MAINLY SE. ISOLD PM TSRA IMPACTS
POSS W MTNS.
MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS
POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE.
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...FITZGERALD/GARTNER/MARTIN
AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1246 PM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1235 PM CDT SUN MAY 10 2015
ADJUSTMENTS TO POPS/TSTM COVERAGE WERE MADE TO ACCOUNT FOR
CURRENT STORMS MOVING NORTH OVER WESTERN PART OF AREA AND EXPECTED
BIG INCREASE SHORTLY FURTHER EAST...OF COURSE CURRENT TORNADO
WATCH IS GOOD.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SURFACE ANALYSIS VERY EARLY THIS MORNING SHOWING THE SURFACE
LOW BEGINNING TO PUSH INTO SOUTHERN NEBRASKA...ON TRACK TO LIFT INTO
OUR AREA BY MID DAY. PRESENT RADAR SHOWING BAND OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH MIDLEVEL WARM AIR ADVECTION/ISENTROPIC
LIFT TRACKING NORTHWARD INTO THE MO RIVER CORRIDOR. EXPECT THIS TO
CONTINUE TO SPREAD NORTHWARD THROUGH THE MORNING...THEN WILL MOST
LIKELY GET A BREAK IN THE ACTIVITY AS A DRY SLOT BEGINS TO WORK INTO
THE AREA BY MID TO LATE MORNING.
MODELS ARE ALL IN DECENT AGREEMENT ON TAKING THE AFOREMENTIONED
SURFACE LOW UP THROUGH THE JAMES RIVER VALLEY DURING THE
AFTERNOON...WITH THE EXCEPTION BEING THE GFS WHICH TRACKS THE LOW
MUCH FARTHER TO THE EAST...SO DISCARDED THAT SOLUTION. USING THE
MODEL CONSENSUS LOW PRESSURE POSITION WOULD PUT THE WARM FRONT
SOMEWHERE IN THE VICINITY OF A MITCHELL SD TO SPENCER LINE BY 21Z.
TO THE SOUTH OF THIS...AFTERNOON TEMPERATURES LOOK TO CLIMB WELL
INTO THE 70S...WITH MUCAPE VALUES REACHING INTO THE 1200 TO 1500 J/KG
RANGE SOUTH OF THE WARM FRONT BY LATE AFTERNOON. THE 0 TO 6 KM BULK
SHEAR LOOKS TO BE INCREDIBLE BY AFTERNOON...WITH THE RAP PROGGING
VALUES OF 50 TO 60 KTS IN THE VICINITY OF THE BOUNDARY. BOTH THE
RAP AND HRRR INDICATE DISCRETE THUNDERSTORM DEVELOPMENT THROUGH THE
LOWER MO RIVER VALLEY/NORTHWESTERN IOWA SOMETIME IN THE 19Z TO 20Z
WINDOW...THEN TRANSITIONING TO MORE MULTICELLULAR THROUGH THE LATER
AFTERNOON AND EVENING AS THE WHOLE COMPLEX LIFTS TO THE NORTH AND
EAST. BASED ON THE ABOVE MENTIONED CONVECTIVE PARAMETERS IT SEEMS
THAT A FEW SEVERE STORMS ARE PRETTY LIKELY WITH LARGE HAIL AND
DAMAGING WINDS. IN ADDITION...RAP 0 TO 1 KM HELICITY VALUES ARE
RUNNING ROUGHLY AROUND 160 UNITS ALONG THE WARM FRONT...WITH 0 TO 1
EHI AROUND 1...SO CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED
TORNADO THREAT NEAR THE BOUNDARY BETWEEN 20Z AND 00Z.
SHOWERS AND THUNDERSTORMS WILL LIFT OFF TO THE NORTH AND EAST
THROUGH THE MID AND LATE EVENING AS THE LOW AND ASSOCIATED FRONTAL
BOUNDARY TRACK EASTWARD...WITH THE SEVERE THREAT WANING FAIRLY
QUICKLY IN THE EVENING AS THE INSTABILITY WEAKENS. COOLER AIR WILL
BEGIN TO FILTER IN BEHIND THE SYSTEM WITH OVERNIGHT LOWS IN THE
UPPER 30S TO MID 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL LINGER INTO MONDAY AS ANOTHER LOBE OF ENERGY
ROTATES AROUND SLOWLY DEPARTING UPPER LOW. WILL BE A BLUSTERY AND
COOL DAY WITH NORTHWEST WINDS 20 TO 35 MPH AND TEMPERATURES LARGELY
STUCK IN THE 40S. SHOWERS WILL DECREASE SOUTHWEST TO NORTHEAST AS
THE UPPER LOW PULLS AWAY MONDAY NIGHT...WITH CLEARING EXPECTED OVER
ALL BUT THE FAR NORTHEAST BY DAYBREAK TUESDAY. COOL AIR MASS WILL
ALLOW TEMPERATURES TO FALL INTO THE MID-UPPER 30S...BUT WINDS SHOULD
REMAIN UP ENOUGH TO PRECLUDE ANY FROST DEVELOPMENT. SURFACE RIDGE
MOVES ACROSS THE AREA TUESDAY/TUESDAY EVENING...WITH MOSTLY SUNNY
SKIES HELPING TEMPERATURES RISE INTO THE MID 50S TO LOWER 60S.
LONGER RANGE PORTION OF THE FORECAST WEDNESDAY THROUGH SATURDAY
BEGINS WITH UPPER RIDGE SHIFTING EAST INTO THE MISSISSIPPI VALLEY
WHILE BROAD TROUGH DEEPENS OFF THE WEST COAST. WHILE LONGER RANGE
MODELS GENERALLY AGREE ON LARGE SCALE PATTERN SHOWING DEEP TROUGH
SLOWLY WORKING INTO THE ROCKIES WHILE UPPER RIDGE DOMINATES ACROSS
THE SOUTHEASTERN CONUS...SEEING QUITE A BIT OF DISPARITY AMONG THE
MODELS IN HANDLING OF VARIOUS SHORTWAVES EJECTING OUT OF THE
WESTERN TROUGH INTO THE NORTHERN/CENTRAL PLAINS. RESULT IS LOWER
CONFIDENCE PRECIPITATION FORECAST FOR LATE NEXT WEEK...AND HAVE
STRAYED LITTLE FROM BROAD MODEL CONSENSUS WHICH CURRENTLY FOCUS
HIGHER CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN
TOWARD THE START OF THE WEEKEND. A LITTLE BETTER AGREEMENT SHOWING
GRADUAL WARMING TREND... WITH DAYTIME HIGHS CLIMBING BACK INTO THE
70S BY LATE IN THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1235 PM CDT SUN MAY 10 2015
GENERALLY IFR CEILINGS AND AREAS OF VISIBILITY 3-5SM SHRA/TSRA FAR
WESTERN PART OF THE FORECAST AREA INCLUDING KHON...AFT 11/00Z THIS
AREA WILL SEE CEILINGS 1-2K FEET VARIABLE TO BELOW 1K FEET WITH
SCATTERED -SHRA. OVER CENTRAL AND EASTERN PART OF THE AREA
CEILINGS 1-3K FEET WITH SOME CEILINGS BELOW 1K FEET ESPECIALLY
NORTH OF KFSD. AREAS OF VISIBILITY 3-5SM IN SHRA/TSRA...THEN AFTER
11/03Z CEILINGS 1-2K FEET VARIABLE TO BELOW 1K FEET...SCT -SHRA
MAINLY NORTH OF FSD. SURFACE GUSTS ABOVE 25 KNOTS FROM THE
SOUTHEAST OVER SOUTHEAST PART OF THE AREA...OTHERWISE SURFACE
GUSTS ABOVE 25 KNOTS FROM THE W/NW DEVELOPING FROM THE WEST AFTER
11/12Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...JM
LONG TERM...JH
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
629 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SURFACE ANALYSIS VERY EARLY THIS MORNING SHOWING THE SURFACE
LOW BEGINNING TO PUSH INTO SOUTHERN NEBRASKA...ON TRACK TO LIFT INTO
OUR AREA BY MID DAY. PRESENT RADAR SHOWING BAND OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH MIDLEVEL WARM AIR ADVECTION/ISENTROPIC
LIFT TRACKING NORTHWARD INTO THE MO RIVER CORRIDOR. EXPECT THIS TO
CONTINUE TO SPREAD NORTHWARD THROUGH THE MORNING...THEN WILL MOST
LIKELY GET A BREAK IN THE ACTIVITY AS A DRY SLOT BEGINS TO WORK INTO
THE AREA BY MID TO LATE MORNING.
MODELS ARE ALL IN DECENT AGREEMENT ON TAKING THE AFOREMENTIONED
SURFACE LOW UP THROUGH THE JAMES RIVER VALLEY DURING THE
AFTERNOON...WITH THE EXCEPTION BEING THE GFS WHICH TRACKS THE LOW
MUCH FARTHER TO THE EAST...SO DISCARDED THAT SOLUTION. USING THE
MODEL CONSENSUS LOW PRESSURE POSITION WOULD PUT THE WARM FRONT
SOMEWHERE IN THE VICINITY OF A MITCHELL SD TO SPENCER LINE BY 21Z.
TO THE SOUTH OF THIS...AFTERNOON TEMPERATURES LOOK TO CLIMB WELL
INTO THE 70S...WITH MUCAPE VALUES REACHING INTO THE 1200 TO 1500 J/KG
RANGE SOUTH OF THE WARM FRONT BY LATE AFTERNOON. THE 0 TO 6 KM BULK
SHEAR LOOKS TO BE INCREDIBLE BY AFTERNOON...WITH THE RAP PROGGING
VALUES OF 50 TO 60 KTS IN THE VICINITY OF THE BOUNDARY. BOTH THE
RAP AND HRRR INDICATE DISCRETE THUNDERSTORM DEVELOPMENT THROUGH THE
LOWER MO RIVER VALLEY/NORTHWESTERN IOWA SOMETIME IN THE 19Z TO 20Z
WINDOW...THEN TRANSITIONING TO MORE MULTICELLULAR THROUGH THE LATER
AFTERNOON AND EVENING AS THE WHOLE COMPLEX LIFTS TO THE NORTH AND
EAST. BASED ON THE ABOVE MENTIONED CONVECTIVE PARAMETERS IT SEEMS
THAT A FEW SEVERE STORMS ARE PRETTY LIKELY WITH LARGE HAIL AND
DAMAGING WINDS. IN ADDITION...RAP 0 TO 1 KM HELICITY VALUES ARE
RUNNING ROUGHLY AROUND 160 UNITS ALONG THE WARM FRONT...WITH 0 TO 1
EHI AROUND 1...SO CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED
TORNADO THREAT NEAR THE BOUNDARY BETWEEN 20Z AND 00Z.
SHOWERS AND THUNDERSTORMS WILL LIFT OFF TO THE NORTH AND EAST
THROUGH THE MID AND LATE EVENING AS THE LOW AND ASSOCIATED FRONTAL
BOUNDARY TRACK EASTWARD...WITH THE SEVERE THREAT WANING FAIRLY
QUICKLY IN THE EVENING AS THE INSTABILITY WEAKENS. COOLER AIR WILL
BEGIN TO FILTER IN BEHIND THE SYSTEM WITH OVERNIGHT LOWS IN THE
UPPER 30S TO MID 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL LINGER INTO MONDAY AS ANOTHER LOBE OF ENERGY
ROTATES AROUND SLOWLY DEPARTING UPPER LOW. WILL BE A BLUSTERY AND
COOL DAY WITH NORTHWEST WINDS 20 TO 35 MPH AND TEMPERATURES LARGELY
STUCK IN THE 40S. SHOWERS WILL DECREASE SOUTHWEST TO NORTHEAST AS
THE UPPER LOW PULLS AWAY MONDAY NIGHT...WITH CLEARING EXPECTED OVER
ALL BUT THE FAR NORTHEAST BY DAYBREAK TUESDAY. COOL AIR MASS WILL
ALLOW TEMPERATURES TO FALL INTO THE MID-UPPER 30S...BUT WINDS SHOULD
REMAIN UP ENOUGH TO PRECLUDE ANY FROST DEVELOPMENT. SURFACE RIDGE
MOVES ACROSS THE AREA TUESDAY/TUESDAY EVENING...WITH MOSTLY SUNNY
SKIES HELPING TEMPERATURES RISE INTO THE MID 50S TO LOWER 60S.
LONGER RANGE PORTION OF THE FORECAST WEDNESDAY THROUGH SATURDAY
BEGINS WITH UPPER RIDGE SHIFTING EAST INTO THE MISSISSIPPI VALLEY
WHILE BROAD TROUGH DEEPENS OFF THE WEST COAST. WHILE LONGER RANGE
MODELS GENERALLY AGREE ON LARGE SCALE PATTERN SHOWING DEEP TROUGH
SLOWLY WORKING INTO THE ROCKIES WHILE UPPER RIDGE DOMINATES ACROSS
THE SOUTHEASTERN CONUS...SEEING QUITE A BIT OF DISPARITY AMONG THE
MODELS IN HANDLING OF VARIOUS SHORTWAVES EJECTING OUT OF THE
WESTERN TROUGH INTO THE NORTHERN/CENTRAL PLAINS. RESULT IS LOWER
CONFIDENCE PRECIPITATION FORECAST FOR LATE NEXT WEEK...AND HAVE
STRAYED LITTLE FROM BROAD MODEL CONSENSUS WHICH CURRENTLY FOCUS
HIGHER CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN
TOWARD THE START OF THE WEEKEND. A LITTLE BETTER AGREEMENT SHOWING
GRADUAL WARMING TREND... WITH DAYTIME HIGHS CLIMBING BACK INTO THE
70S BY LATE IN THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 623 AM CDT SUN MAY 10 2015
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO LIFT THROUGH THE AREA
DURING THE MORNING...THEN THE ACTIVITY WILL LESSEN INTO THE
AFTERNOON. ADDITIONAL THUNDERSTORMS ARE EXPECTED TO DEVELOP AFTER
20Z TODAY...AND SOME OF THESE MAY BE SEVERE THROUGH FAR
SOUTHEASTERN SOUTH DAKOTA...NORTHWESTERN IOWA...AND NORTHEASTERN
NEBRASKA THROUGH 00Z. MVFR TO SOME IFR CEILINGS WILL BE COMMON
THROUGH THE TAF PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...JH
AVIATION...JM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
412 AM CDT SUN MAY 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SURFACE ANALYSIS VERY EARLY THIS MORNING SHOWING THE SURFACE
LOW BEGINNING TO PUSH INTO SOUTHERN NEBRASKA...ON TRACK TO LIFT INTO
OUR AREA BY MID DAY. PRESENT RADAR SHOWING BAND OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH MIDLEVEL WARM AIR ADVECTION/ISENTROPIC
LIFT TRACKING NORTHWARD INTO THE MO RIVER CORRIDOR. EXPECT THIS TO
CONTINUE TO SPREAD NORTHWARD THROUGH THE MORNING...THEN WILL MOST
LIKELY GET A BREAK IN THE ACTIVITY AS A DRY SLOT BEGINS TO WORK INTO
THE AREA BY MID TO LATE MORNING.
MODELS ARE ALL IN DECENT AGREEMENT ON TAKING THE AFOREMENTIONED
SURFACE LOW UP THROUGH THE JAMES RIVER VALLEY DURING THE
AFTERNOON...WITH THE EXCEPTION BEING THE GFS WHICH TRACKS THE LOW
MUCH FARTHER TO THE EAST...SO DISCARDED THAT SOLUTION. USING THE
MODEL CONSENSUS LOW PRESSURE POSITION WOULD PUT THE WARM FRONT
SOMEWHERE IN THE VICINITY OF A MITCHELL SD TO SPENCER LINE BY 21Z.
TO THE SOUTH OF THIS...AFTERNOON TEMPERATURES LOOK TO CLIMB WELL
INTO THE 70S...WITH MUCAPE VALUES REACHING INTO THE 1200 TO 1500 J/KG
RANGE SOUTH OF THE WARM FRONT BY LATE AFTERNOON. THE 0 TO 6 KM BULK
SHEAR LOOKS TO BE INCREDIBLE BY AFTERNOON...WITH THE RAP PROGGING
VALUES OF 50 TO 60 KTS IN THE VICINITY OF THE BOUNDARY. BOTH THE
RAP AND HRRR INDICATE DISCRETE THUNDERSTORM DEVELOPMENT THROUGH THE
LOWER MO RIVER VALLEY/NORTHWESTERN IOWA SOMETIME IN THE 19Z TO 20Z
WINDOW...THEN TRANSITIONING TO MORE MULTICELLULAR THROUGH THE LATER
AFTERNOON AND EVENING AS THE WHOLE COMPLEX LIFTS TO THE NORTH AND
EAST. BASED ON THE ABOVE MENTIONED CONVECTIVE PARAMETERS IT SEEMS
THAT A FEW SEVERE STORMS ARE PRETTY LIKELY WITH LARGE HAIL AND
DAMAGING WINDS. IN ADDITION...RAP 0 TO 1 KM HELICITY VALUES ARE
RUNNING ROUGHLY AROUND 160 UNITS ALONG THE WARM FRONT...WITH 0 TO 1
EHI AROUND 1...SO CANNOT RULE OUT THE POSSIBILITY OF AN ISOLATED
TORNADO THREAT NEAR THE BOUNDARY BETWEEN 20Z AND 00Z.
SHOWERS AND THUNDERSTORMS WILL LIFT OFF TO THE NORTH AND EAST
THROUGH THE MID AND LATE EVENING AS THE LOW AND ASSOCIATED FRONTAL
BOUNDARY TRACK EASTWARD...WITH THE SEVERE THREAT WANING FAIRLY
QUICKLY IN THE EVENING AS THE INSTABILITY WEAKENS. COOLER AIR WILL
BEGIN TO FILTER IN BEHIND THE SYSTEM WITH OVERNIGHT LOWS IN THE
UPPER 30S TO MID 40S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 AM CDT SUN MAY 10 2015
SCATTERED SHOWERS WILL LINGER INTO MONDAY AS ANOTHER LOBE OF ENERGY
ROTATES AROUND SLOWLY DEPARTING UPPER LOW. WILL BE A BLUSTERY AND
COOL DAY WITH NORTHWEST WINDS 20 TO 35 MPH AND TEMPERATURES LARGELY
STUCK IN THE 40S. SHOWERS WILL DECREASE SOUTHWEST TO NORTHEAST AS
THE UPPER LOW PULLS AWAY MONDAY NIGHT...WITH CLEARING EXPECTED OVER
ALL BUT THE FAR NORTHEAST BY DAYBREAK TUESDAY. COOL AIR MASS WILL
ALLOW TEMPERATURES TO FALL INTO THE MID-UPPER 30S...BUT WINDS SHOULD
REMAIN UP ENOUGH TO PRECLUDE ANY FROST DEVELOPMENT. SURFACE RIDGE
MOVES ACROSS THE AREA TUESDAY/TUESDAY EVENING...WITH MOSTLY SUNNY
SKIES HELPING TEMPERATURES RISE INTO THE MID 50S TO LOWER 60S.
LONGER RANGE PORTION OF THE FORECAST WEDNESDAY THROUGH SATURDAY
BEGINS WITH UPPER RIDGE SHIFTING EAST INTO THE MISSISSIPPI VALLEY
WHILE BROAD TROUGH DEEPENS OFF THE WEST COAST. WHILE LONGER RANGE
MODELS GENERALLY AGREE ON LARGE SCALE PATTERN SHOWING DEEP TROUGH
SLOWLY WORKING INTO THE ROCKIES WHILE UPPER RIDGE DOMINATES ACROSS
THE SOUTHEASTERN CONUS...SEEING QUITE A BIT OF DISPARITY AMONG THE
MODELS IN HANDLING OF VARIOUS SHORTWAVES EJECTING OUT OF THE
WESTERN TROUGH INTO THE NORTHERN/CENTRAL PLAINS. RESULT IS LOWER
CONFIDENCE PRECIPITATION FORECAST FOR LATE NEXT WEEK...AND HAVE
STRAYED LITTLE FROM BROAD MODEL CONSENSUS WHICH CURRENTLY FOCUS
HIGHER CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...AND AGAIN
TOWARD THE START OF THE WEEKEND. A LITTLE BETTER AGREEMENT SHOWING
GRADUAL WARMING TREND... WITH DAYTIME HIGHS CLIMBING BACK INTO THE
70S BY LATE IN THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1016 PM CDT SAT MAY 9 2015
CONDITIONS WILL GRADUALLY DIMINISH OVERNIGHT AS A STRONG LOW
PRESSURE SHIFTS NORTHWARD. SHOWERS WILL INCREASE IN COVERAGE FROM
THE SOUTH AND SOUTHWEST AND A FEW THUNDERSTORMS WILL ALSO BE
POSSIBLE FROM ABOUT 9Z THROUGH 14Z. OTHERWISE CEILINGS WILL LOWER
TO MVFR AND POSSIBLY IFR AT TIMES AS THE STRONG LOW LEVEL JET AND
MOISTURE ALOFT INCREASE. WHILE THERE IS LIKELY TO BE A BIT OF A
LULL IN ACTIVITY FROM LATE MORNING INTO THE EARLY AFTERNOON STRONG
TO SEVERE THUNDERSTORMS WILL BECOME POSSIBLE OVER FAR SOUTHEAST
SOUTH DAKOTA, NORTHEAST NEBRASKA AND NORTHWEST IOWA AFTER ABOUT
21Z. MVFR CEILINGS WILL BE POSSIBLE THROUGH MUCH OF THE PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...JH
AVIATION...08
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1243 PM CDT SUN MAY 10 2015
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1101 AM CDT SUN MAY 10 2015/
DISCUSSION...LATEST WATER VAPOR SATELLITE/WSR-88D VAD WIND
PROFILES SHOW A MESOSCALE CONVECTIVE SYSTEM MOVING OVER WESTERN
ARKANSAS...NORTHEAST OKLAHOMA...AND NORTHEAST TEXAS LATE THIS
MORNING. REGIONAL WSR-88D RADAR TRENDS SHOW STORMS EXHIBITING
QUASI-LINEAR CHARACTERISTICS OVER WESTERN ARKANSAS. AS OF 10 AM
CDT ACROSS THE MID SOUTH...TEMPERATURES ARE IN THE 70S AT MOST
LOCATIONS WITH MOSTLY SUNNY SKIES PREVALENT ACROSS MUCH OF THE
AREA AS OF THIS MOMENT.
LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THE BEST CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE MAINLY WEST OF THE MISSISSIPPI
RIVER THIS AFTERNOON WHERE BETTER FORCING AND INSTABILITY MAY
RESIDE. FURTHER EAST...CONFIDENCE IS MUCH LOWER AND REDUCED RAIN
CHANCES NORTH OF I-40 ACROSS WEST TENNESSEE DOWN TO ISOLATED
COVERAGE. WILL UPDATE ALL ELEMENTS AS NEEDED TO ACCOUNT FOR THESE
TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
PREV DISCUSSION... /ISSUED 628 AM CDT SUN MAY 10 2015/
DISCUSSION...
UPDATED FOR 12Z AVIATION.
PREV DISCUSSION... /ISSUED 416 AM CDT SUN MAY 10 2015/
DISCUSSION...
CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS
NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS
WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK
INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE
FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER
70S WITH LIGHT SOUTH WINDS.
TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART
OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE
THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF
THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF
SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE
MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING
ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND
THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY.
THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A
PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT
A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW
STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE
MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN.
TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF
CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT
DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS
WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL
SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN
PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND
THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND
THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE
MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY
TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL
SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF
CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS
DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION
WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS
THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND
0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE
ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE
MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS
UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION
EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS
ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT
IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS
NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS
QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO
DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL.
WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING
AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE
STORMS IN THE HWO ON MONDAY.
OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE
POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE
MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A
GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING
ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN
THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING
FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT
A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE
3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE
CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT
IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR
EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS
ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING
PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT
WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE
70S...LOWS IN THE 50S AND LOWER 60S.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE
BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK.
NEAR NORMAL TEMPS.
SJM
&&
.AVIATION...18Z TAFS
A LINE OF STRONG TO SEVERE THUNDERSTORMS IN WEST ARKANSAS HAS BEEN
SLOWING ITS FORWARD PROGRESS AND WEAKENING SLIGHTLY OVER THE LAST
SEVERAL HOURS. SHORT TERM GUIDANCE SUGGESTS THIS TREND SHOULD
CONTINUE AND THE NORTHERN END OF THE LINE SHOULD BECOME THE FOCUS.
THAT SEEMS TO BE ALREADY HAPPENING. AS A RESULT...DO NOT FEEL LIKE
IT WILL POSE A THREAT TO ANY OF THE TAF SITES. JBR MAY BE THE
EXCEPTION AS STORMS PASS TO THE NORTH...BUT WILL ONLY INCLUDE VCTS
FOR NOW. BETTER RAIN AND THUNDER CHANCES WILL OCCUR LATER TONIGHT
AS ANOTHER LINE DEVELOPS AND APPROACHES FROM THE WEST.
SHOWERS MAY DEVELOP BEFORE THIS NEXT LINE OVER SOUTHERN ARKANSAS
AND NORTH MISSISSIPPI AND TRACK NORTH...BUT COVERAGE SHOULD REMAIN
LIMITED. VISIBLE SATELLITE DOES NOT SUGGEST ANY DEVELOPMENT IS
IMMINENT.
MVFR CIGS ARE EXPECTED BEFORE SUNRISE AT ALL SITES ALONG WITH MVFR
VIS DUE TO RAIN AT JBR MKL AND MEM...CONTINUING THROUGH 18Z. WINDS
SOUTHERLY AROUND 10KT WITH HIGHER GUSTS...SHIFTING SOUTHWESTERLY
LATE IN THE PERIOD.
30
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1101 AM CDT SUN MAY 10 2015
.DISCUSSION...LATEST WATER VAPOR SATELLITE/WSR-88D VAD WIND
PROFILES SHOW A MESOSCALE CONVECTIVE SYSTEM MOVING OVER WESTERN
ARKANSAS...NORTHEAST OKLAHOMA...AND NORTHEAST TEXAS LATE THIS
MORNING. REGIONAL WSR-88D RADAR TRENDS SHOW STORMS EXHIBITING
QUASI-LINEAR CHARACTERISTICS OVER WESTERN ARKANSAS. AS OF 10 AM
CDT ACROSS THE MID SOUTH...TEMPERATURES ARE IN THE 70S AT MOST
LOCATIONS WITH MOSTLY SUNNY SKIES PREVALENT ACROSS MUCH OF THE
AREA AS OF THIS MOMENT.
LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THE BEST CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE MAINLY WEST OF THE MISSISSIPPI
RIVER THIS AFTERNOON WHERE BETTER FORCING AND INSTABILITY MAY
RESIDE. FURTHER EAST...CONFIDENCE IS MUCH LOWER AND REDUCED RAIN
CHANCES NORTH OF I-40 ACROSS WEST TENNESSEE DOWN TO ISOLATED
COVERAGE. WILL UPDATE ALL ELEMENTS AS NEEDED TO ACCOUNT FOR THESE
TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 628 AM CDT SUN MAY 10 2015/
DISCUSSION...
UPDATED FOR 12Z AVIATION.
PREV DISCUSSION... /ISSUED 416 AM CDT SUN MAY 10 2015/
DISCUSSION...
CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS
NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS
WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK
INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE
FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER
70S WITH LIGHT SOUTH WINDS.
TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART
OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE
THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF
THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF
SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE
MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING
ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND
THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY.
THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A
PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT
A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW
STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE
MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN.
TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF
CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT
DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS
WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL
SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN
PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND
THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND
THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE
MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY
TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL
SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF
CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS
DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION
WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS
THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND
0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE
ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE
MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS
UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION
EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS
ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT
IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS
NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS
QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO
DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL.
WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING
AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE
STORMS IN THE HWO ON MONDAY.
OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE
POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE
MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A
GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING
ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN
THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING
FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT
A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE
3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE
CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT
IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR
EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS
ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING
PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT
WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE
70S...LOWS IN THE 50S AND LOWER 60S.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE
BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK.
NEAR NORMAL TEMPS.
SJM
&&
.AVIATION...
12Z TAFS
UPPER LEVEL DISTURBANCES WILL BRING SEVERAL ROUNDS OF SHOWERS AND
STORMS TO JBR THROUGHOUT THE PERIOD...BUT MAINLY LATER FOR
MEM...MKL AND TUP. IN THE HEAVIEST STORMS EXPECT MVFR/IFR
CONDITIONS...OTHERWISE THE SITES WILL BE VFR. STRONGER SOUTH
WINDS ANTICIPATED WITH GUSTS NEAR 20 KTS AT JBR AND MEM. WINDS
WILL SUBSIDE SOME TONIGHT...BUT REMAIN GUSTY AT MEM AND JBR.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
628 AM CDT SUN MAY 10 2015
.DISCUSSION...
UPDATED FOR 12Z AVIATION.
&&
.PREV DISCUSSION... /ISSUED 416 AM CDT SUN MAY 10 2015/
DISCUSSION...
CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS
NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS
WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK
INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE
FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER
70S WITH LIGHT SOUTH WINDS.
TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART
OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE
THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF
THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF
SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE
MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING
ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND
THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY.
THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A
PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT
A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW
STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE
MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN.
TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF
CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT
DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS
WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL
SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN
PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND
THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND
THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE
MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY
TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL
SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF
CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS
DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION
WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS
THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND
0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE
ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE
MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS
UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION
EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS
ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT
IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS
NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS
QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO
DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL.
WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING
AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE
STORMS IN THE HWO ON MONDAY.
OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE
POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE
MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A
GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING
ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN
THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING
FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT
A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE
3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE
CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT
IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR
EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS
ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING
PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT
WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE
70S...LOWS IN THE 50S AND LOWER 60S.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE
BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK.
NEAR NORMAL TEMPS.
SJM
&&
.AVIATION...
12Z TAFS
UPPER LEVEL DISTURBANCES WILL BRING SEVERAL ROUNDS OF SHOWERS AND
STORMS TO JBR THROUGHOUT THE PERIOD...BUT MAINLY LATER FOR
MEM...MKL AND TUP. IN THE HEAVIEST STORMS EXPECT MVFR/IFR
CONDITIONS...OTHERWISE THE SITES WILL BE VFR. STRONGER SOUTH
WINDS ANTICIPATED WITH GUSTS NEAR 20 KTS AT JBR AND MEM. WINDS
WILL SUBSIDE SOME TONIGHT...BUT REMAIN GUSTY AT MEM AND JBR.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH THROUGH MONDAY AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
416 AM CDT SUN MAY 10 2015
.DISCUSSION...
CURRENTLY...MOIST AND ACTIVE SOUTHWEST FLOW ALOFT CONTINUES ACROSS
NORTHWEST PARTS OF THE MIDSOUTH. ONE CONVECTIVE COMPLEX HAS
WEAKENED AND MOVES INTO SE/MO WHILE ANOTHER HAS ALREADY MOVED BACK
INTO NORTHEAST ARKANSAS. ELSW ACROSS THE MIDSOUTH SKIES RANGE
FROM PARTLY TO MOSTLY CLOUDY WITH TEMPS FROM THE MID 60S TO LOWER
70S WITH LIGHT SOUTH WINDS.
TODAY...A QUIET MOTHERS DAY IS NOT IN THE CARDS FOR AT LEAST PART
OF THE MIDSOUTH. UPPER LEVEL DISTURBANCES WILL CONTINUE TO RIPPLE
THROUGH THE SOUTHWEST FLOW ALOFT ACROSS NORTH AND WEST PARTS OF
THE MIDSOUTH. SHORT RANGE GUIDANCE INDICATES A GOOD DEAL OF
SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE NORTHERN 1/3RD OF THE
MID SOUTH THIS MORNING WHICH MATCHES WELL WITH WHAT IS DEVELOPING
ON RADAR. AS THIS ACTIVITY LIFTS NORTH BY NOON BOTH THE HRRR AND
THE NAM BOTH INDICATE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
PUSHING INTO AT LEAST EASTERN AR AND THE MO BOOTHEEL LATER TODAY.
THAT BEING SAID AREAS EAST OF I-55 AND SOUTH OF I-40 WILL HAVE A
PRETTY NICE DAY AS UPPER RIDGING STRENGTHENS A BIT THERE. EXPECT
A GOOD DEAL OF SUNSHINE AND TEMPS IN THE MID TO UPPER 80S. A FEW
STRONG STORMS ARE POSSIBLE MAINLY ALONG AND WEST OF THE
MISSISSIPPI RIVER WITH GUSTY WINDS AND LOCALLY HEAVY RAIN.
TONIGHT AND MONDAY...FIRST WE MAY BE DEALING WITH THE ROUND OF
CONVECTION DEPICTING BY THE HRRR/NAM IN THE EVENING. ONCE THAT
DIES OUT ATTENTION TURNS WEST WHERE THE UPPER LOW OVER THE PLAINS
WILL CONTINUE TO LIFT NORTHEAST OVERNIGHT. A DECENT MID LEVEL
SHORTWAVE WILL ROTATE AROUND THE UPPER LOW AND INTO THE SOUTHERN
PLAINS LATER TODAY AND TONIGHT IGNITING NUMEROUS SHOWERS AND
THUNDERSTORMS ALONG AN ADVANCING COLD FRONT. THESE SHOWERS AND
THUNDERSTORMS WILL PUSH EAST ACROSS ARKANSAS OVERNIGHT. GIVEN THE
MOIST AND UNSTABLE AIRMASS ACROSS THE LOWER MISSISSIPPI VALLEY
TONIGHT AND THE WEAK DISTURBANCES AHEAD OF THE MAIN MID LEVEL
SHORTWAVE IT COULD BE MESSY OVERNIGHT WITH SEVERAL AREAS OF
CONVECTION POPPING UP AHEAD OF THE MAIN LINE OF STORMS. IT IS
DIFFICULT TO FIGURE OUT THE LOCATION AND THE AMOUNT OF CONVECTION
WHICH IN TURN MAKES IT CHALLENGING TO FORECAST SEVERE WEATHER. AS
THE MAIN MID LEVEL SHORTWAVE APPROACHES LATE SUNDAY NIGHT AND
0-6KM BULK SHEAR VALUES CLIMB ABOVE 40...STORMS SHOULD BECOME MORE
ORGANIZED. A FEW STORMS COULD BE SEVERE WITH DAMAGING WINDS THE
MAIN THREAT LATE SUNDAY NIGHT ACROSS EASTERN ARKANSAS. HOW THINGS
UNFOLD ON MONDAY WILL DEPEND ON THE AMOUNT OF ONGOING CONVECTION
EARLY IN THE DAY. THIS WILL IMPACT HOW STABLE THE AIRMASS IS
ACROSS THE MIDSOUTH AND HOW MUCH AND HOW STRONG THE REDEVELOPMENT
IS ALONG THE COLD FRONT. ANOTHER PROBLEM IS THE MAIN ENERGY LIFTS
NORTHEAST OF THE AREA DURING THE AFTERNOON AND THE COLD FRONT IS
QUICKLY WEAKENING AS IT PUSHING INTO THE AREA. MODELS SEEM TO
DEPICT THAT THE CONVERGENCE ALONG THE FRONT FALLS APART AS WELL.
WE COULD EASILY END UP WITH A DECAYING MCS DURING MONDAY MORNING
AND THAT IS IT. FOR NOW WILL CONTINUE WITH A FEW STRONG TO SEVERE
STORMS IN THE HWO ON MONDAY.
OK...SEVERE WEATHER IS UNCERTAIN BUT MORE CERTAIN IS THE
POTENTIAL FOR FLASH FLOODING ACROSS EASTERN ARKANSAS AND THE
MISSOURI BOOTHEEL THROUGH MONDAY. MUCH OF THIS AREA RECEIVED A
GOOD SHOT OF RAIN YESTERDAY MORNING AND OVERNIGHT WITH MORE MOVING
ACROSS NORTHEAST ARKANSAS OVER THE NEXT COUPLE OF HOURS. THROW IN
THE POTENTIAL FOR MORE STORMS LATER THIS AFTERNOON/EVENING
FOLLOWED BY THE MAIN SHOW LATER TONIGHT INTO MONDAY IT SEEMS THAT
A FLASH FLOOD WATCH IS A GOOD IDEA. SEVERAL COUNTIES ALREADY HAVE
3 HR FFG VALUES AS LOW AS AN INCH. PRECIP WATER VALUES WILL BE
CLIMBING OVER THE NEXT 24 HRS TO AROUND 1.8 INCHES AND THIS FRONT
IS NOT A QUICK MOVER. SO FLASH FLOOD WATCH WILL BE ISSUED FOR
EASTERN AR AND MO BOOTHEEL TODAY THROUGH NOON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...LINGERING SHOWERS AND THUNDERSTORMS
ACROSS MAINLY SOUTHERN SECTIONS MONDAY NIGHT FOLLOWED BY A DRYING
PERIOD INTO THE MIDDLE OF THE WEEK WITH SOME VERY PLEASANT
WEATHER. HIGHS ON TUESDAY AND WEDNESDAY WILL BE MAINLY IN THE
70S...LOWS IN THE 50S AND LOWER 60S.
THURSDAY THROUGH SATURDAY...HIGH PRESSURE MOVES EAST AND WE MOVE
BACK INTO MORE ACTIVE SOUTHWEST FLOW AGAIN WITH CHANCES FOR
SHOWERS AND THUNDERSTORMS INCREASING TOWARD THE END OF THE WEEK.
NEAR NORMAL TEMPS.
SJM
&&
.AVIATION...
06Z TAFS
WEAK UPPER DISTURBANCE WAS MOVING EAST THROUGH AR AT 0445Z. THIS
FEATURE WILL LIKELY HELP SUSTAIN SHRA/ISOLATED TSRA INTO THE
MIDSOUTH OVERNIGHT. TS POTENTIAL WILL LIKELY BE BEST IN THE JBR
AREA.
MUCH OF SUNDAY SHOULD SEE VFR. SLIGHT RIDGING SHOULD KEEP
MENTIONABLE TS CHANCES AT BAY UNTIL AFTERNOON...OR MORE LIKELY...
EARLY SUNDAY EVENING AT JBR.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY
AFTERNOON FOR CLAY-CRAIGHEAD-CRITTENDEN-CROSS-GREENE-
LAWRENCE-LEE AR-MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST.
FRANCIS.
MO...FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY
AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1145 PM CDT SAT MAY 9 2015
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 806 PM CDT SAT MAY 9 2015/
UPDATE...
MAIN UPDATE TO THE FORECAST WAS TO INCREASE PRECIP CHANCES ACROSS
WESTERN PORTIONS OF THE CWA WHERE A COMPLEX OF SHOWERS AND
THUNDERSTORMS WAS ONGOING. WHILE LARGE SCALE FORCING REMAINS
WEAK...CONTINUED CONVERGENCE DRIVEN BY SOUTHEASTERLY FLOW AHEAD
THE SYSTEM WILL AT LEAST MAINTAIN THIS COMPLEX FOR THE NEXT 1-2
HOURS...IF NOT LONGER. TEMPERATURES ACROSS THIS AREA WERE COOLER
THAN FORECAST AS WELL...THEREFORE...ADJUSTED TRENDS TO REFLECT
THIS THROUGH MIDNIGHT.
A VERY COMPLEX SURFACE PATTERN WILL CONTINUE THROUGH TOMORROW WITH SEVERAL
OUTFLOW BOUNDARIES LIKELY STREWN ACROSS THE CWA. PRECIP CHANCES
MAY NEED TO BE ADJUSTED ONCE MORE LATER THIS EVENING AS TRENDS
EVOLVE THROUGH THE NIGHT.
TVT
PREV DISCUSSION... /ISSUED 650 PM CDT SAT MAY 9 2015/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
PREV DISCUSSION... /ISSUED 320 PM CDT SAT MAY 9 2015/
DISCUSSION...SURFACE ANALYSIS THIS AFTERNOON PLACES A QUASI-
STATIONARY BOUNDARY OVER PORTIONS OF SOUTHERN MISSOURI AND BACK
INTO OKLAHOMA AND PORTIONS OF THE TEXAS/OKLAHOMA PANHANDLE.
SHOWERS AND THUNDERSTORM COVERAGE HAS DECREASED IN COVERAGE ACROSS
THE MID SOUTH THIS AFTERNOON AS THE ATMOSPHERE HAS STABILIZED
SOMEWHAT. A CLUSTER OF SHOWERS ARE LOCATED ACROSS PORTIONS OF
NORTH CENTRAL AND NORTHEAST ARKANSAS AS OF LATE THIS AFTERNOON.
TEMPERATURES AS OF 3 PM CDT ARE IN THE UPPER 70S TO LOWER 80S AT
MOST LOCATIONS.
WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES OVER THE PAST FEW
HOURS HAVE INDICATED ANOTHER MESOSCALE CONVECTIVE SYSTEM /MCS/ HAS
DEVELOPED ACROSS OKLAHOMA AND THE RED RIVER VALLEY OF TEXAS.
WRF/GFS/ECMWF MODELS INDICATE THIS ACTIVITY SHOULD REMAIN MAINLY
WEST OF THE FORECAST AREA THIS EVENING. INTERESTINGLY ENOUGH...THE
19Z HRRR INDICATES CONVECTIVE ACTIVITY OVER NORTHEAST
TEXAS/EASTERN OKLAHOMA...AND SOUTHWEST ARKANSAS MAY SPREAD INTO
PORTIONS OF THE MID SOUTH ALONG AND WEST OF THE RIVER BY EARLY TO
MIDDLE EVENING. THIS HIGH RESOLUTION MODEL/S OUTPUT MAY BE TRYING
TO SUGGEST A COLD POOL DEVELOPING UPSTREAM AND BRINGING THE
CONVECTION INTO THE FORECAST AREA. WILL GO WITH CHANCE POPS ALONG
AND WEST OF THE MISSISSIPPI RIVER TONIGHT. EVENING SHIFT WILL
MONITOR MESOSCALE TRENDS AND ADJUST FORECAST AS NECESSARY
ESPECIALLY IF THE OUTLYING HRRR ENDS UP BEING THE CORRECT SHORT
TERM FORECAST SOLUTION.
SHORT TERM MODELS INDICATE SOUTHWEST FLOW ALOFT WILL REMAIN IN
PLACE ACROSS THE MID SOUTH ON SUNDAY WITH MOST IF NOT ALL SHOWERS
AND THUNDERSTORMS OCCURING UPSTREAM OF THE MID SOUTH.
CONSEQUENTLY...HAVE KEPT POPS ISOLATED AT BEST DURING THE DAY WITH
THE EXCEPTION OF EXTREME NORTHEAST MISSISSIPPI. ADDITIONAL SHOWERS
AND THUNDERSTORMS WILL DEVELOP AND SPREAD INTO THE MID SOUTH
SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS INTO THE MID SOUTH.
THE BEST UPPER LEVEL FORCING AND FAVORABLE WINDS WILL MOVE
NORTHEAST OF THE FORECAST AREA BY MONDAY. SUFFICIENT
INSTABILITY...0-6 KM BULK SHEAR AND THE APPROACHING FRONT MAY BE
ENOUGH TO PRODUCE A CONDITIONAL THREAT FOR A FEW STRONG TO
PERHAPS SEVERE THUNDERSTORMS ACROSS THE MID SOUTH LATE SUNDAY
NIGHT INTO MONDAY.
THIS FRONT IS EXPECTED TO PUSH SOUTH OF THE FORECAST AREA BY
TUESDAY AFTERNOON/TUESDAY NIGHT AND BRING MAINLY RAIN FREE WEATHER
THROUGH WEDNESDAY NIGHT. SHOWER/THUNDERSTORM CHANCES WILL RETURN
LATE NEXT WEEK AS THE FRONT RETURNS BACK NORTH ACROSS THE MID
SOUTH.
CJC
&&
.AVIATION...
06Z TAFS
WEAK UPPER DISTURBANCE WAS MOVING EAST THROUGH AR AT 0445Z. THIS
FEATURE WILL LIKELY HELP SUSTAIN SHRA/ISOLATED TSRA INTO THE
MIDSOUTH OVERNIGHT. TS POTENTIAL WILL LIKELY BE BEST IN THE JBR
AREA.
MUCH OF SUNDAY SHOULD SEE VFR. SLIGHT RIDGING SHOULD KEEP
MENTIONABLE TS CHANCES AT BAY UNTIL AFTERNOON...OR MORE LIKELY...
EARLY SUNDAY EVENING AT JBR.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
400 PM CDT SUN MAY 10 2015
.DISCUSSION...
ALL EYES ARE UPON CENTRAL TEXAS WHERE SPC HAS MODERATE RISK OF
SEVERE STORMS AND THERE HAS ALREADY BEEN ONE TORNADIC STORM TO
PUSH THROUGH DENTON TX. SFC ANALYSIS OVER SE TX HAS TYPICAL WARM
SECTOR AIRMASS WITH GUSTY SE WINDS AND DEWPOINTS IN THE LOW 70S.
WATER VAPOR IMAGERY SHOWS UPPER LOW OVER C PLAINS WITH ELONGATED
TROUGH AXIS STRETCHING BACK INTO THE S ROCKIES AS EXPECTED
YESTERDAY. UPPER AIR ANALYSIS SHOWS JET STREAK COMING OUT OF
MEXICO WHICH LATEST RAP ANALYSES HAVE OVER S TX AND JUST STARTING
TO REACH SE TX. JET STREAK SHOULD MOVE OVER THE AREA BY 03Z
TONIGHT SO THINK ANY CAPPING MAY ERODED BY LARGE SCALE ASCENT.
LATEST HRRR RUNS HAS CONVECTION NOW OVER C TX FORMING A SQUALL
LINE AND PUSHING INTO THE BRAZOS VALLEY AFTER MIDNIGHT TO 3AM.
THIS EVOLUTION INTO SOME BOWING SEGMENTS SUPPORTS SPC
ENHANCED/SLIGHT RISK OF SEVERE FOR TONIGHT. GIVEN
SHEAR/INSTABILITY PARAMETERS FOR TONIGHT...THINK THIS KIND OF
CONVECTION WILL CERTAINLY BE POSSIBLE.
MONDAY LOOKS LIKE THERE WILL BE PLENTY OF RECOVERY IN THE AIRMASS
FOR IT TO DESTABILIZE WITH MODERATE TO HIGH CAPE BY THE AFTERNOON.
DEEP LAYER SHEAR SEEMS TO WEAKEN BUT LOW LEVEL WIND FIELDS LOOK
MUCH LESS THAN THE LAST COUPLE OF DAYS. A FRONTAL BOUNDARY DOES
PUSH INTO N TX WHICH MAY SLACKEN THE PRESSURE GRADIENT ACROSS THE
AREA. FRONT MAY BE THE FOCUS FOR SOME SEVERE STORMS WITH HEAVY
RAINFALL FOR NORTHERN PORTIONS OF THE AREA. TROUBLE PART OF THE
FORECAST IS THAT MODELS ARE NOT ALL THAT AGGRESSIVE WITH PRECIP
MONDAY DESPITE A MUCH WEAKER CAP AND FAVORABLE UPPER LEVEL
PARAMETERS. NOT ONLY THAT PRECIP WATER VALUES INCREASE TO AROUND
1.8 INCHES AND THEN OVERNIGHT AT 06Z TUE GFS SHOWS 2 INCH PRECIP
WATER VALUES. THIS IS JUST AS A SHORT WAVE TROUGH MOVES OVER THE
REGION. MODELS CONTINUE TO HIT HILL COUNTRY AND S TX TO THE
COASTAL PLAIN WITH QUITE A BIT OF PRECIP WHILE PRECIP TOTALS FOR
SE TX REMAIN SOMEWHAT LOW GIVEN THE SITUATION. ONE OF THE FEW
MODELS THAT DOES PRODUCE QUITE A BIT OF PRECIP OVER THE AREA IS
THE 12Z WRF-ARW WHICH BRINGS A SQUALL LINE INTO THE AREA FROM S TX
CONSISTENT WITH UPPER LEVEL FORCING FROM THE SHORTWAVE. OVERALL
KEPT POPS ON THE HIGH SIDE BUT PINNING DOWN THE DETAILS IS STILL A
CHALLENGE. WPC SEEMS TO AGREE WITH HEAVY RAINFALL THREAT AS MOST
OF THE AREA MON/TUE IS IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
LOOKING AT 3HR FFG VALUES...NEED A GOOD 4-5 INCHES OF RAIN IN A 3
HR PERIOD TO GET FLASH FLOODING. CAN HOLD OFF ON ANY FLOOD WATCH
AND SEE WHAT HAPPENS WITH FIRST COUPLE ROUNDS OF PRECIP. THIS WILL
HELP DETERMINE THE NEED FOR A WATCH GIVEN THE UNCERTAINTY IN THE
FORECAST.
BEYOND TUE IT LOOKS LIKE LATE WED/THUR MAY BE ANOTHER ROUND FOR
HEAVY RAINFALL. AGAIN THE FORECAST WILL KEEP HIGH RAIN CHANCE
GOING THROUGH THUR AND THEN TAPER OFF FOR THE REST OF THE WEEK.
THE SET UP FOR THURSDAY IS VERY SIMILAR WITH A SHORT WAVE TROUGH
MOVING ACROSS THE AREA. BIG DIFFERENCE IS THAT THE ECMWF SEEMS TO
HAVE THIS WAVE COMING ACROSS WED AFTERNOON WITH THE GFS HAVING TWO
WEAK WAVES...ONE WED AFTERNOON AND ANOTHER BY 12Z THUR. GOING INTO
THE END OF THE WEEK...UPPER LEVEL RIDGING DEVELOPS OVER TX AND
SHOULD SUPPORT LOWER POPS AND A DRY FORECAST. THIS MAY ALSO ALLOW
FOR MAX TEMPS IN THE UPPER 80S.
39
&&
.MARINE...
MODERATE TO STRONG SOUTHEAST WINDS AND ELEVATED SEAS ARE EXPECTED
TO CONTINUE OVER THE BAYS AND COASTAL WATERS TONIGHT AS THE
PRESSURE GRADIENT REMAINS TIGHT ACROSS THE AREA. A WEAK FRONTAL
BOUNDARY IS STILL EXPECTED TO EDGE INTO THE NORTHERN PARTS OF
SOUTHEAST TEXAS LATE TONIGHT AND ON INTO EARLY MONDAY MORNING.
THIS FRONT WILL HELP TO WEAKEN THE GRADIENT AND ALLOW FOR
DECREASED WINDS AND SEAS FOR THE FIRST PART OF THE WEEK. AS THE
FRONT SLOWLY WASHES OUT...ONSHORE WINDS ARE EXPECTED TO SLOWLY
INCREASE DURING THE LATTER PART OF THE WEEK AND ON INTO NEXT
WEEKEND.
THE PERSISTENT ONSHORE WINDS CONTINUE TO SUPPORT STRONG RIP
CURRENTS AND THE POSSIBILITY OF ELEVATED TIDES. LEVELS COULD
APPROACH 3 FEET FOR LOCATIONS IN AND AROUND THE HOUSTON SHIP
CHANNEL AND ALONG THE GULF FACING BEACHES OF THE BOLIVAR PENINSULA
THIS AFTERNOON AND THIS EVENING. WAVE RUN-UP HAS THE POTENTIAL TO
BE A PROBLEM FOR LOW LYING AREAS ALONG THE BOLIVAR PENINSULA. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 84 68 76 68 / 80 60 80 70 60
HOUSTON (IAH) 74 85 70 81 70 / 30 60 70 70 40
GALVESTON (GLS) 76 82 75 80 74 / 20 50 60 60 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON...
MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 AM CDT MONDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1235 PM CDT SUN MAY 10 2015
.AVIATION...
SCT/BKN DECKS AROUND 4000 FEET ARE ANTICIPATED THIS AFTERNOON AT
OUR NORTHERN SITES (IAH/CXO/UTS/CLL) WITH POSSIBLE MVFR CEILINGS
(2000-3000 FEET) AT OUR SOUTHERN SITES (HOU/SGR/LBX/GLS). RADAR IS
SHOWING SOME SCATTERED -SHRA BEGINNING TO DEVELOP ACROSS THE AREA
TOO...SO WILL HAVE VCSH TO COVER THAT FOR NOW. IF WE WARM UP ENOUGH...
SOME TSRA WILL BE POSSIBLE. EXPECT SSE/SE WINDS TO BE AROUND 15 TO 20
KNOTS AND GUSTY. THIS EVENING AND OVERNIGHT AS WINDS DECREASE...EYES
BEGIN TO TURN TOWARD A LINE OF SHRA/TSRA EXPECTED TO DEVELOP OFF TO
OUR W AND NW. LAST COUPLE OF HRRR MODEL RUNS HAVE BEEN SHOWING THIS
POSSIBLE STRONG/SEVERE LINE MOVING INTO THE CLL/UTS AREAS LATER THIS
EVENING. HAVE GONE AHEAD AND ADDED VCTS TO THOSE TAFS TO ACCOUNT FOR
THIS POSSIBILITY. FURTHER SOUTH...NOT REAL CONFIDENT ON WHAT THIS
POSSIBLE LINE OF STORMS WILL LOOK LIKE AS IT SLOWLY EDGES ITS WAY
TO THE E AND SE TOWARD THE CXO/IAH AREA. SINCE IT HAS A CHANCE ON
STAYING INTACT...WENT AHEAD AND ADDED VCTS AT CXO BEFORE SUNRISE
AND BETWEEN IAH AND GLS AFTER SUNRISE. EXPECT TAF AMENDMENTS LATER
THIS AFTERNOON AND THIS EVENING AS WE SEE HOW THIS LINE TAKES SHAPE.
42
&&
.PREV DISCUSSION... /ISSUED 1039 AM CDT SUN MAY 10 2015/
UPDATE...
MORNING FORECAST UPDATE.
DISCUSSION...
THUNDERSTORM ACTIVITY CONTINUES TO INCREASE OVER THE NW HILL
COUNTRY NE TOWARDS C TX. TORNADO WATCH HAS BEEN ISSUED TO THE W
AND NW OF HGX FORECAST AREA. SPC HAS SLIGHT RISK OF SEVERE STORMS
MAINLY FOR TONIGHT NORTH OF A BRENHAM TO LUFKIN LINE. AN ENHANCED
RISK OF SEVERE STORMS IS JUST TO THE NW OF A COLLEGE STATION TO
CROCKETT LINE. THE EXPECTATION IS THAT A LINE OF SCATTERED STORMS
WILL FORM OVER C TX AND THEN FORM A SOLID SQUALL LINE LATER THIS
AFTERNOON AND TONIGHT. THIS SYSTEM COULD THEN MOVE INTO SE TX.
THIS AFTERNOON THERE WILL BE QUITE A BIT OF INSTABILITY AND STRONG
SHEAR TO SUPPORT ROTATING STORMS OVER C TX HENCE THE TORNADO
WATCH. INSTABILITY SHOULD DECREASE THIS EVENING OVER SE TX AND NOT
BE QUITE AS SUPPORTIVE OF SEVERE STORMS. THE OTHER QUESTION FOR
SEVERE WEATHER OVER SE TX WILL BE CAPPING. LOOKING AT 12Z
SOUNDINGS FROM DRT...CRP...LCH IT IS HARD TO GET A HANDLE ON THE
CAPPING OVER OUR AREA. DRT AND LCH DO NOT HAVE MUCH OF A CAP SO
LOOKS LIKE THERE WILL BE A TIGHT GRADIENT ON WHERE THE CAP EXISTS
OR IS WEAK ENOUGH THAT HEATING CAN OVERCOME THE CAP. CRP SHOWS A
SUBSTANTIAL CAP BUT LOOKING AT AMDAR/ACARS SOUNDINGS OVER THE
AREA THINK HOUSTON IS JUST ENOUGH CAPPED TO LIMIT THUNDERSTORM
ACTIVITY. AREAS TO NORTH WHERE SPC HAS SEVERE OUTLOOK WILL NEED TO
BE MONITORED. FOR NOW ONLY CHANGES TO THE FORECAST WAS TO DECREASE
POPS A BIT THIS AFTERNOON AND ADJUST TONIGHT`S POPS FOR TIMING OF
CONVECTION MOVING INTO THE AREA FROM C TX.
FOR THE AFTERNOON FORECAST WE ARE REALLY GOING TO HAVE TO LOOK
HARD AT RAINFALL TOTALS AND POTENTIAL FOR HEAVY RAINFALL/FLOODING.
RIGHT NOW WPC HAS MUCH OF SE TX IN A SLIGHT RISK OF EXCESSIVE
RAINFALL FOR MONDAY AND TUESDAY. THIS IS ALSO WHEN SEVERAL
ATMOSPHERIC PARAMETERS COMBINE TO SUPPORT THAT THREAT. BUT THE
DETAILS OF HOW MUCH RAIN...WHERE AND WHEN ARE STILL A CHALLENGE
DUE TO TIMING A SHORTWAVE TROUGH COMING ACROSS THE AREA.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 86 72 84 68 77 / 30 70 70 80 80
HOUSTON (IAH) 86 73 86 71 81 / 30 30 60 80 60
GALVESTON (GLS) 83 76 83 74 80 / 20 20 50 70 70
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON...
MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1138 PM CDT SAT MAY 9 2015
.AVIATION...
VFR AND LIGHT WINDS EXPECTED THRU THE TAF PERIOD WITH THE
EXCEPTION OF THE POSSIBILITY OF SOME LOW CLOUDS AT KCDS THIS
MORNING. KCDS REMAINS ON THE MOIST SIDE OF A SFC TROUGH THAT HAS
BEEN MOSTLY STATIONARY THRU THE EVENING BUT WILL BEGIN TO MOVE EWD
AGAIN TOWARD SUNRISE. SEEING SOME AREAS OF LOW CLOUD NORTH AND NE
OF KCDS ATTM WITH MODELS CONTINUING TO INDICATE A WINDOW FOR IFR
OR MVFR CIGS BTWN 06Z AND 12Z.
&&
.PREV DISCUSSION... /ISSUED 903 PM CDT SAT MAY 9 2015/
UPDATE...
HAVE REMOVED EVENING THUNDER MENTION FOR THE FAR ERN SLIVER OF
THE FCST AREA AS THAT THREAT HAS MOVED EAST OF THE REGION. TEMP
AND HUMIDITY FCST FOR THE ROLLING PLAINS AND FAR SERN PANHANDLE
PROBLEMATIC AS THE DRYLINE DID NOT QUITE GET ENTIRELY EAST OF THE
FCST AREA. CURRENTLY SEEING A BATTLE BETWEEN OUTFLOW-REINFORCED
MOIST AIRMASS MOVING EWD AND THE DRYLINE/SFC TROUGH. THIS TROUGH
SHOULD END UP MOVING TO THE EAST AGAIN AS THE UPPER LOW OVER
COLORADO MOVES ONTO THE PLAINS. HOWEVER UNTIL THEN...DEW POINTS
IN THE 60S WILL KEEP TEMPS THERE MILD UNTIL LATE TONIGHT AND MAY
SEE SOME LOW CLOUDS MOVE INTO THE CHILDRESS AREA AROUND MIDNIGHT
AND LINGER FOR SEVERAL HOURS BEFORE DRIER LOW LEVEL AIR CAN
FINALLY SWEEP THE MOISTURE EWD.
PREV DISCUSSION... /ISSUED 634 PM CDT SAT MAY 9 2015/
AVIATION...
DRYLINE HAS SHIFTED AS FAR EAST AS JUST OUTSIDE KCDS. GUSTY WSW
WINDS BEHIND SHOULD DIMINISH BY MID-EVENING WITH VFR CONDITIONS
EXPECTED AT BOTH KLBB AND KPVW. HOWEVER...EAST OF THE DRYLINE
VCTY KCDS RICH LOW LEVEL MOISTURE REMAINS. WITH A PUSH OF THE
DRYLINE A BIT TO THE WEST TONIGHT WOULD EXPECT MOISTURE TO BE
REINFORCED FROM DOWN THE RED RIVER VALLEY. THUS HAVE SIDED WITH
THE HI-RES HRRR AND INTRODUCED LOW CLOUDS IN THE KCDS TAF FROM
LATE EVENING TO AROUND SUNRISE SUNDAY. MAY VERY WELL END UP BEING
IFR THERE IF THESE CLOUDS DEVELOP...BUT HAVE STARTED JUST ABOVE
THAT CUTOFF ATTM.
PREV DISCUSSION... /ISSUED 534 PM CDT SAT MAY 9 2015/
SHORT TERM...
PACIFIC FRONT/DRYLINE HAS SURGED EAST THIS AFTERNOON AS EXPECTED AS
DRY SLOTTING HAS MOVED IN ALOFT ACROSS THE REGION. CORE OF THE UPPER
LOW CURRENTLY NEAR THE FOUR CORNERS REGION WILL LIFT TOWARD THE
FRONT RANGE INTO THIS EVENING WITH A SURFACE LOW HUGGING THE FRONT
RANGE/CENTRAL HIGH PLAINS. DEWPOINTS HAVE CRASHED INTO THE 20S/30S
ACROSS MUCH OF THE CAPROCK...BUT OUTFLOW BOUNDARIES FROM THIS
MORNING/S CONVECTION COUPLED WITH STOUT MOIST SOUTHEASTERLY FLOW
ACROSS THE BIG COUNTRY HAVE HUNG UP THE DRYLINE ON A LINE FROM LAKE
MACKENZIE TO ROARING SPRINGS TO HASKELL. HAVE LEFT A SLIGHT CHANCE
FOR STORMS IN THE FORECAST ALONG AND EAST OF HIGHWAY 83 AS SURFACE
CONVERGENCE ALONG THIS BOUNDARY MAY BE JUST ENOUGH TO INITIATE
ISOLATED DEVELOPMENT WHEN COUPLED WITH CONTINUED WEAK HEIGHT FALLS
ALOFT. THIS CHANCE WILL BE HIGHLY CONDITIONAL ON WHETHER ENOUGH
HEATING WILL BE ABLE TO OCCUR IN A WORKED OVER/COLD POOL PLAGUED
AIRMASS.
WILL CONTINUE TO SEE A FEW LOBES OF ADDITIONAL ENERGY ROUND THE BASE
OF THE UPPER LOW THROUGH EARLY SUNDAY...BUT DRIER AIR COURTESY OF
DOWNSLOPE SURFACE WINDS WILL KEEP STORMS MAINLY CONFINED EAST OF THE
FAR EASTERN EDGE OF THE ROLLING PLAINS. SUNDAY MORNING LOOKS TO
BRING THE NEXT/LAST APPRECIABLE ROUND OF UPPER ENERGY TOWARD WEST
TEXAS...SO WILL KEEP A MENTION SOUTHEAST OF A GUTHRIE TO ASPERMONT
LINE AS 40 DEGREE DEWPOINTS MAY BE ENOUGH TO SPARK A QUICK STORM.
OTHERWISE...BREEZY WEST/SOUTHWEST WINDS SHOULD ACCOMPANY
TEMPERATURES TOPPING OUT IN THE MID 70S NORTHWEST TO LOW 80S SOUTH
AND EAST UNDER MOSTLY CLEAR SKIES.
LONG TERM...
WE/LL SEE A BREAK IN OUR ACTIVE WEATHER PATTERN THROUGH MONDAY...BUT
THE CHANCE FOR SHOWERS AND T-STORMS WILL INCREASE AGAIN NEXT WEEK.
THE COLD FRONT WILL BE EXITING THE FORECAST AREA MONDAY MORNING WITH
BREEZY NORTHERLY WINDS DIMINISHING AND SWINGING AROUND TO THE E-SE
BY MONDAY EVENING. IT WILL BE ON THE COOL SIDE BEHIND THE FRONT
MONDAY WITH HIGHS MAINLY IN THE UPPER 60S AND LOWER 70S. SHORTWAVE
RIDGING WILL DEVELOP OVER WEST TEXAS TUESDAY DOWNSTREAM OF A UPPER
TROUGH MOVING ACROSS THE WEST COAST. INDICATIONS ARE THAT THIS
TROUGH WILL BE PROGRESSIVE AND MAY BEGIN TO AFFECT THE REGION BY
TUESDAY EVENING. THE NAM IS THE MOST BULLISH OF THE MODELS WITH THE
QPF FORECAST...GENERATING A SWATH OF RAIN COMING IN FORM THE SW TUES
AFTERNOON AND EVENING. THIS MAY BE OVERDONE GIVEN THAT IT WILL TAKE
SOME TIME FOR LOW-LEVEL MOISTURE TO RECHARGE AND THE ECMWF AND GFS
ARE SLOWER WITH THE LIFT. WE WILL MAINTAIN A CHANCE OF PRECIP IN THE
SW SPLNS...TAPERING DOWN FARTHER EAST TUESDAY EVENING AND
OVERNIGHT. THE GFS AND ECMWF STILL INDICATE THAT WED WILL BE THE
PRIMARY PERIOD FOR RAIN CHANCES WITH A WELL-DEVELOPED SHORTWAVE
OUT OF NM AND ACROSS WEST TEXAS...AT ROUGHLY THE SAME TIME DEEP
GULF MOISTURE IS MOVING BACK INTO THE AREA. PROGGED QPF AMOUNTS
ARE QUITE HIGH...WITH A SIMILAR APPEARANCE TO OUR LAST STRONGLY
FORCED CONVECTION MAY 5TH. HOWEVER...THIS IS STILL 5 DAYS OUT AND
WE MAY NOT SEE LIFT AND MOISTURE QUITE AS SYNCHRONIZED THIS TIME.
SHORTWAVE LIFTS NWD AWAY FROM THE AREA ON THURSDAY BUT THE UPPER
TROUGH TO OUR WEST WILL BE QUICK TO RELOAD AS NEXT ROUND OF
ENERGY DROPS INTO THE SW. THE EMCWF AND GFS BEGIN TO DIVERGE BY
THIS TIME AS THE ECMWF DROPS A UPPER LOW ALL THE WAY INTO SRN
CALIFORNIA WHILE THE GFS BREAKS THE ENERGY UP INTO SEVERAL PIECES
MOVING ACROSS THE GREAT BASIN AND 4-CORNERS REGIONS. EITHER WAY
LOW-LEVEL MOISTURE SHOULD BE DRAWN WEST INTO ERN NM AND
PERTURBATIONS IN THE SWRLY FLOW OVER WTX SHOULD BE SUFFICIENT TO
SUPPORT AT LEAST SOME DIURNAL T- STORM DEVELOP EACH AFTN AND
EVENING FRI...SAT AND PERHAPS INTO SUNDAY JUST DEPENDING ON HOW
THE UPPER TROUGH/LOW ACROSS THE WEST EVOLVES.
FIRE WEATHER...
WARM...DRY AND BREEZY CONDITIONS WILL PERSIST THROUGH EARLY EVENING
ACROSS THE CAPROCK. OVERNIGHT MOISTURE RECOVERY WILL BE POOR AS
THE DRYLINE REMAINS TO THE EAST. SIMILAR CONDITIONS ARE EXPECTED
ACROSS THE ENTIRE FORECAST AREA ON SUNDAY. HOWEVER...THE FIRE
WEATHER CONCERNS WILL REMAIN LOW DUE TO THE RECENT WIDESPREAD WETTING
RAINS A GREENUP. A COLD FRONT WILL MOVE THROUGH SUNDAY NIGHT AND
MONDAY MORNING BRINGING A PERIOD OF GUSTY NORTHERLY WINDS.
SEASONABLE COOL AND DRY CONDITIONS ARE EXPECTED MONDAY...WITH
MOISTURE LEVELS AND RAIN CHANCES ON THE INCREASE BY LATE TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 44 74 41 69 / 0 0 10 0
TULIA 48 74 44 69 / 0 0 10 0
PLAINVIEW 45 75 45 69 / 0 0 10 0
LEVELLAND 46 77 46 71 / 0 0 10 0
LUBBOCK 46 78 47 71 / 0 0 10 0
DENVER CITY 48 78 47 73 / 0 0 0 0
BROWNFIELD 48 79 48 73 / 0 0 10 0
CHILDRESS 59 81 51 71 / 0 0 10 0
SPUR 54 81 51 71 / 0 0 10 0
ASPERMONT 60 83 54 73 / 10 20 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
923 PM CDT MON MAY 11 2015
.UPDATE...
IT WILL REMAIN WINDY OVERNIGHT AS COLD AIR ADVECTION KEEPS LOW-
LEVEL LAPSE RATES STEEP AND MIXED UP TO 30 KT WINDS AROUND 2K FT.
ADJUSTED NEAR TEMPS DOWN A NUDGE BUT LOWS IN THE MID-40S LOOK ON
TRACK GIVEN CLOUDS AND MIXING. LATEST NAM12 SUPPORTS HRRR AND
KEEPS ANY SPOTTY LIGHT SHOWERS/DRIZZLE MAINLY ACROSS OUR NRN
COUNTIES WHICH CURRENT FORECAST COVERS WELL.
&&
.AVIATION/06Z TAFS/...
CIGS CONTINUE TO HOVER AROUND THE VFR/MVFR BREAK...WITH UPSTREAM
OBS SUPPORTING SREF MVFR CIG PROBABILITIES INDICATING MVFR CLOUDS
SHOULD REACH KMSN AND KUES...WITH A GOOD CHANCE FOR A PERIOD OF
MVFR AT KMKE AND KENW AFTER 08Z. CIGS EXPECTED TO LIFT TO VFR
LEVELS AROUND MIDDAY. WINDS WILL REMAIN GUSTY...WITH MIXING UP TO
30 KT WINDS AROUND 2K FT TO CONTINUE OVERNIGHT...WITH DEEPER
MIXING TUESDAY KEEPING GUSTS AROUND 25 KTS THROUGH THE DAYLIGHT
HOURS.
&&
.MARINE...
SMALL CRAFT ADVISORY CONTINUES FOR GUSTY WEST WINDS THAT WILL TURN
WNW TUESDAY. GRADIENT BEGINS TO EASE IN THE EARLY AFTERNOON AS LOW
PULLS AWAY AND HIGH PRESSURE BUILDS TOWARD LAKE MICHIGAN. END TIME
OF ADVISORY MAY HAVE TO BE EXTENDED IF FULL SET OF 00Z DATA
INDICATES A SLOWER EASING OF WINDS...LATEST NAM 925 MB WINDS STILL
25 KTS AT 00Z WED...WITH SBM FORECAST SOUNDINGS SHOWING MIXING UP
TO 25 KT WINDS AS LATE AS 02Z BUT LOWERING QUICKLY AFTER.
&&
.PREV DISCUSSION... /ISSUED 223 PM CDT MON MAY 11 2015/
TONIGHT - CONFIDENCE...MEDIUM
COLD AND DRY ADVECTION TAKING PLACE WRAPPING AROUND SOUTH SIDE OF
SURFACE LOW SHIFTING EAST FROM NRN WI. PRECIP TO THE EAST AND BREAKS
IN THE CLOUD COVER WILL BE REPLACED BY STRATOCU FIELD ARRIVING FROM
MN AND IA. GUSTY SW WIND REGIME WILL STAY IN PLACE WITH BUFKIT
SOUNDINGS SHOW DECENT MIXING EVEN DURING THE OVERNIGHT HOURS. THE
NAM IS MOST AGGRESSIVE WITH SHRA WRAPPING INTO THE NRN CWA WHILE THE
GFS/ECMWF HOLD IT OFF TO THE NW OF THE CWA. WILL HAVE SOME SMALL
POPS LATE ACROSS THE FAR NORTH TO MATCH UP WITH GRB/ARX AND TO
ACCOUNT FOR THE NAM TRENDS.
TUESDAY - CONFIDENCE...MEDIUM
LOW LEVEL COLD POOL WILL PERSIST WITH 850 TEMPS RANGING FROM 0C TO
-3C ACROSS SRN WI. UPPER LOW ACRS NRN WI WILL SHIFT WELL TO OUR EAST
WITH MID LEVEL STILL SHOWING A CYCLONIC CURVATURE...THOUGH MORE
HINTS OF NVA ON THE NAM. LLVL RH PROGS SHOW THE CLOUD COVER
LINGERING THROUGH AT LEAST THE MORNING WITH SOME BREAKUP DURING THE
AFTERNOON WITH COLUMN SHOWING LESS SATURATION WITHIN 900-800
MILLIBAR LAYER. BUFKIT DOES SHOW COLUMN MIXING TO 850 MILLIBARS SO
GUSTY WNW WIND REGIME WILL PREVAIL. HIGHS MOSTLY IN THE MID/UPPER
50S.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS
HIGH.
SURFACE HIGH PRESSURE MOVES IN TUESDAY NIGHT...CLEARING OUT ANY
LINGERING CLOUDS AND ALLOWING WINDS TO BECOME CALM/LIGHT. THE DRY
AIRMASS SHOULD BRING NEAR FROSTY TEMPS AFTER MIDNIGHT. MOST PLACES
SHOULD BE IN THE 30S...WITH TEMPS LOW ENOUGH NORTH OF MADISON AND
ACROSS PARTS OF THE SOUTHEAST...ALONG AND WEST OF THE KETTLE
MORAINE SPINE...TO BRING SOME PATCHY FROST.
WEDNESDAY WILL WARM TO THE LOWER/MID 60S WEST OF MADISON AS THE
RIDGE BEGINS TO MOVE OFF. BUT THE EAST WILL STILL BE UNDER THE
INFLUENCE OF A COOL EASTERLY FETCH OFF THE LAKE. SOME HIGH LEVEL
CLOUDS MAY SPILL INTO THE AREA OVER THE TOP OF THE MID LEVEL
RIDGE...SO SKY COVER IS SOMEWHAT IN QUESTION. THE RIDGE AXIS WILL
CONTINUE TO SHIFT EAST WEDNESDAY NIGHT WITH CONTINUED INCREASING
CLOUDS ANTICIPATED.
THURSDAY AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
AS THE RIDGE MOVES OFF...A DECENT MID LEVEL TROF WILL LIFT
NORTHEAST INTO MINNESOTA AND WISCONSIN. THERE IS STRONG WARM AIR
ADVECTION ACCOMPANYING THIS SYSTEM AS THE LOW LEVEL JET AHEAD OF
THE LOW INCREASES TO 40 TO 50 KNOTS. THE SOUNDINGS LOOK RATHER
STABLE...SO THE THUNDER THREAT WITH THIS LOOKS MINIMAL. BUT...WE
COULD STILL HEAR SOME RUMBLES. HOPEFULLY...ANOTHER GOOD RAIN FOR
OUR FARMING COMMUNITY. RAIN SHOULD SPREAD INTO THE AREA MAINLY
AFTER MID DAY ON THURSDAY AND CONTINUE THROUGH THURSDAY
NIGHT...DIMINISHING ON FRIDAY.
FRIDAY NIGHT AND THIS WEEKEND...FORECAST CONFIDENCE IS MEDIUM.
IT LOOKS LIKE A BREAK IN THE WET WEATHER SHOULD ARRIVE FRIDAY
NIGHT WITH BRIEF HIGH PRESSURE MOVING THROUGH AHEAD OF THE NEXT
LOW PRESSURE SYSTEM HEADING IN.
RAIN CHANCES RETURN THIS WEEKEND WITH A BETTER CHANCE FOR STRONG
THUNDERSTORMS BY SUNDAY AS A POTENT LOW PRESSURE SYSTEM AND COLD
FRONT MOVE IN. NATURALLY...THERE IS MODEL DISAGREEMENT THIS FAR
OUT...BUT THERE IS AGREEMENT THAT WE WILL BE IN A WARMER
AIRMASS...SO LOOK FOR PLEASANT TEMPS. IT JUST MAY END UP BEING A
BIT STORMY.
AVIATION/00Z TAFS/...LOW PRESSURE ACRS NRN WI WILL CONTINUE TO MOVE
EAST THIS PERIOD. WITH COLD FRONT TO THE EAST A GUSTY SW WIND
USHERING IN A COOLER AND DRY AIRMASS. CLOUD DECREASE LATE THIS
AFTN/EVE WILL BE SHORT LIVED AS CONSIDERABLE STRATOCU WILL WRAP INTO
SRN WI WITH 850 MILLIBAR COLD AIR ADVECTION. THE MVFR CIGS
ASSOCIATED WITH THIS CLOUD DECK WILL LIKELY LINGER INTO TUESDAY AS
THERMAL TROUGH PERSISTS. BEST CHC SHRA LOOKS NORTH OF TAF SITES SO
WILL LEAVE OUT THIS POTENTIAL FOR NOW.
MARINE...GUSTY WSWLY WINDS DEVELOPING IN THE WAKE OF THE COLD
FRONT. THIS WILL SCOUR OUT ANY REMAINING LAKE FOG WITH DRY AIRMASS
TAKING HOLD. WINDS WILL TURN A BIT MORE TO THE WNW ON TUESDAY. A
SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THESE GUSTY WINDS
THROUGH TUESDAY. HIGHER WAVES WILL BE SEEN TOWARDS OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT TUESDAY FOR LMZ643>646.
&&
$$
UPDATE...REM
TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR
TUESDAY NIGHT THROUGH MONDAY...DAVIS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
152 AM EDT TUE MAY 12 2015
.SYNOPSIS...
ANOTHER MILD AND HUMID NIGHT WITH DENSE FOG TONIGHT GIVES WAY TO
ANOTHER WARM DAY WITH SOME SHOWERS AND THUNDERSTORMS POSSIBLE IN
THE AFTERNOON AS THE REMNANTS OF ANA PASS BY. LARGE HIGH PRESSURE
WILL BUILD ACROSS THE EASTERN U.S. WITH DRIER WEATHER THROUGH THE
REMAINDER OF THE WEEK. AN APPROACHING WARM FRONT COULD BRING
SCATTERED SHOWERS NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
150 AM UPDATE...
A FEW SHOWERS HAVE DEVELOPED ACROSS NE CT THROUGH SE MA EARLY
THIS MORNING. ADDITIONAL SHOWERS S OF LONG ISLAND ASSOCD WITH ANA
REMNANTS WILL BE LIFTING N ACROSS THE COASTAL PLAIN THROUGH
DAYBREAK. AN ISOLD TSTM IS POSSIBLE AS ELEVATED INSTABILITY
PARAMETERS ARE MARGINAL.
CONVECTIVE LINE MOVING THROUGH CENTRAL NY IS EXPECTED TO REMAIN
WEST OF SNE THROUGH DAYBREAK.
PREVIOUS DISCUSSION...
BACKDOOR FRONT APPEARS TO HAVE STALLED FROM NE RI THROUGH
PORTIONS OF SE MA. TEMPS IN THE 50S TO THE N AND E OF THE FRONT
AND MAINLY 60S JUST TO THE S AND W. AS REMNANTS OF ANA APPROACHES
LATE TONIGHT...HI-RES GUIDANCE LIFTS THE FRONT BACK TO THE N
OVERNIGHT ACROSS RI AND SE MA.
AREAS OF DENSE FOG HAVE OVERSPREAD THE IMMEDIATE S COAST THIS
EVENING. WITH LOW LEVEL S/SW FLOW EXPECT DENSE FOG THREAT WILL BE
CONFINED TO THE S COAST AND SE MA...AND ALONG NE MA COAST WHERE
WINDS ARE EASTERLY. LATEST HRRR HAS LOWEST VSBYS ALONG THE S AND E
COASTS SO WE TRIMMED THE DENSE FOG ADVISORY AWAY FROM THE COAST.
FINALLY...HAVE INCREASED POPS ACROSS SE COASTAL MA AND CAPE COD
FOR LATE TONIGHT AS REMNANTS OF ANA TRACK TO THE SOUTH. MODELS
SHOW AREA OF DEEPER MOISTURE ALONG WITH SOME ELEVATED INSTABILITY
AT THE NOSE OF A LOW LEVEL JET WHICH SHOULD BRING AN AREA OF
SHOWERS OR AN ISOLD TSTM TO SE COASTAL NEW ENG. LATEST RAP SHOWS
AN AREA OF MEASURABLE RAINFALL LATE TONIGHT OVERSPREADING
PORTIONS OF RI AND SE MA.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
TOMORROW...
THE EARLY MORNING WILL BE MARKED BY A FAIRLY ROBUST DECK OF LOW
LVL CLOUDS AND FOG POSSIBLY AS FAR WEST AS THE CT VALLEY. THIS
WILL TAKE SOME TIME TO BURN OFF DURING THE MORNING AS DIURNAL
MIXING COMMENCES. EXACTLY HOW QUICKLY WILL DETERMINE THE THREAT
FOR CONVECTION/SEVERITY AS A COLD FRONT APPROACHES FOR THE
AFTERNOON.
BY AFTERNOON...AS THE FRONT MAKES IT/S PASS/APPROACH...SOME BREAKS
OF SUN ARE LIKELY ESPECIALLY FOR INTERIOR NRN MA AND WRN CT. THIS
AREA WILL BE THE PLACE TO WATCH AS BUFKIT PROFILES SHOW MODEST
CAPE VALUES APPROACHING 1000-1500 J/KG COMBINED WITH ABOUT 30 KT
OF 0-3KM SHEAR. UPPER LVL PROFILES WILL BE DRYING HOWEVER RATHER
QUICKLY SO IT/S A RACE AGAINST TIME AS TO WHETHER THE DRY AIR OR
INSTABILITY WINS AS THE LOW LVL F-GEN SOURCE APPROACHES. HI-RES
AND EVEN MORE COARSE GUIDANCE ALL SHOWING THE POSSIBILITY OF
AFTERNOON CONVECTIVE ACTIVITY WITH THE FROPA...ESPECIALLY NRN
INTERIOR MA AWAY FROM WHERE THE LOW LVL CLOUDS WILL HOLD IN.
SLIGHT CHANCE OF A STRONG STORM GIVEN THE MODEST SHEAR
VALUES...WHICH COINCIDES WELL WITH THE 18Z DAY TWO SWODY FROM
SPC...WHICH HIGHLIGHTS A MARGINAL RISK. THERE WILL STILL BE SOME
LEFTOVER LOW-LVL MOISTURE FROM ANA AHEAD OF THE FRONT...SO WILL
ALSO NEED TO WATCH FOR HEAVIER RAIN.
OTHER ISSUES FOR TOMORROW...
FIRE WEATHER CONCERNS...
AREAS WHERE THE CLOUD DISSIPATE WILL SEE LOW RELATIVE RH VALUES
AND GIVEN DIURNAL MIXING...WIND GUSTS OF 25-30 MPH AT TIMES.
THEREFORE...HAVE A MARGINAL RISK OF ELEVATED FIRE WEATHER DURING
THE DAY IN SPITE OF THE T-STORM/SHRA POTENTIAL. FOR MORE ON
THIS...SEE THE FIRE WEATHER SECTION BELOW.
HIGH SURF...
THE REMNANTS OF ANA WILL BRING 6 TO 10 FOOT SWELL TO OUR SOUTHERN
COASTAL WATERS TOMORROW. THIS WILL BRING HIGH SURF AND DANGEROUS
RIP CURRENTS TO OUR OCEAN EXPOSED SOUTH FACING BEACHES ON TUE.
GIVEN RELATIVELY WARM TEMPS EXPECTED...WE MAY STILL HAVE TO
CONSIDER A HIGH SURF ADVISORY EVEN THOUGH THE SUMMER SEASON HAS
NOT OFFICIAL BEGUN.
TUESDAY NIGHT...
FINALLY...THE HIGHER DWPTS...DRIER AIR AND IMPROVING CONDITIONS
WILL BE MOVING ACROSS THE REGION FROM W-E DURING THE OVERNIGHT
HOURS. LEFTOVER TSRA/SHRA WILL GENERALLY DIMINISH WITH THE LOSS OF
DIURNAL HEATING...SO THERE MAY BE A FEW CLOUDS STILL TO CONTEND
WITH EARLY. GIVEN THE MASS FIELDS ALSO SUPPORT A MODERATE PRES
GRADIENT...TEMPS ARE NOT LIKELY TO FALL AS LOW AS THEIR POTENTIAL
DESPITE THE DROPPING DWPTS. MINS MAINLY IN THE MID 40S AND LOW
50S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
* BREAK IN THE HEAT ON WEDNESDAY WITH NORMAL TEMPS
* HIGH PRESSURE ON THURS & FRI KEEP CONDITIONS DRY
* RAIN RELIEF POSSIBLE OVER THE WEEKEND WITH APPROACHING LOW
OVERVIEW...
FORECAST GUIDANCE CONTINUES TO BE IN GOOD AGREEMENT FOR MOST OF THE
EXTENDED. NOTICED 11.12Z GUIDANCE LEANED TOWARDS THE 11.00Z GFS FROM
LAST NIGHT IN BRINGING PRECIP INTO THE REGION FOR THE WEEKEND.
OTHERWISE BY LATE WEEKEND INTO EARLY NEXT WEEK APPEARS THAT THE EC
IS MORE AMPLIFIED IN BUILDING A STOUT RIDGE OVER NEW ENGLAND
COMPARED TO THE GFS. THIS COULD MAKE THINGS LESS STORMY THEN
PREVIOUSLY THOUGHT. APPEARS TEMPS WILL LEAN MORE TOWARDS OR JUST
ABOVE NORMAL OVER THE LONG TERM. COULD SEE AN INCREASE IN THE HEAT
BY NEXT WEEK.
DETAILS...
* WEDNESDAY...HIGH CONFIDENCE.
SECONDARY COLD FRONT WILL PASS THROUGH THE REGION PUSHING UPPER LEVEL
TROUGH OFFSHORE AND TEMPS ALOFT TO COOL OVER THE AREA. WINDS WILL
SWITCH TO A MORE NW FLOW...ALLOWING FOR GOOD DOWNSLOPING. PARTLY
SUNNY SKIES WILL ALLOW FOR TEMPS TO WARM INTO THE UPPER 60S...WHICH
IS NEAR NORMAL! DID LOWER DEWPOINTS AND INCREASE WIND GUSTS VERSUS
GUIDANCE AS MIXING ON WED WILL BE VERY GOOD. THIS WILL BRING A RISK
OF FIRE WEATHER CONCERNS TO THE REGION. DETAILS IN THE FIRE WEATHER
SECTION BELOW.
BECAUSE OF THE FALLING TEMPS ALOFT AND MARGINAL MOISTURE FIELD...
HAVE INSERTED A LOW CHANCE FOR AN ISOLATED SHOWER FOR FRANKLIN
COUNTY. CONFIDENCE IS LOW...BUT CANNOT RULE IT OUT.
TEMPS ALOFT WILL DROP THROUGHOUT THE DAY AND INTO THE OVERNIGHT
HOURS. IN FACT 850MB COULD DROP DOWN TO 0C OVERNIGHT. THIS COMBINED
WITH CLEAR SKIES AND DECOUPLE WINDS WILL ALLOW FOR RADIATIONAL
COOLING OVERNIGHT. TEMPS WILL DROP INTO THE LOWER 40S. COULD SEE A
FEW UPPER 30S BUT HAVE A LOW CONFIDENCE ON FROST DEVELOPMENT IN THE
VALLEY LOCALS ACROSS THE NW PORTION OF THE AREA.
* THURSDAY AND FRIDAY...HIGH CONFIDENCE.
HIGH PRESSURE WILL MOVE RIGHT ON IN FOR THURSDAY AND LAST INTO
FRIDAY. THIS WILL ALLOW FOR DRY WEATHER AND PLENTY OF SUNSHINE. HAVE
AN INCREASE CHANCE THAT SEA BREEZES WILL DEVELOP ACROSS THE
COASTLINES FOR BOTH DAYS. TEMPERATURES WILL WARM ABOVE AVERAGE ONCE
AGAIN...WITH HIGHS IN THE LOW 70S ON THURSDAY AND MID 70S ON FRIDAY
AWAY FROM THE COASTLINES.
* THE WEEKEND...MODERATE CONFIDENCE.
HIGH PRESSURE WILL MOVE SOUTH AND OFFSHORE ALLOWING FOR APPROACHING
LOW PRESSURE FROM THE WEST TO PUSH A WARM FRONT OVER THE REGION.
DEPENDING ON WHERE THIS WARM FRONT SETS UP WE COULD SEE A FEW ROUNDS
OF SHOWERS AS A WAVE OR TWO MOVES THROUGH THE AREA. NOT EXPECTING A
DROUGHT BUSTER AS WE NEED ABOUT 3-5 INCHES...BUT SOME RAIN RELIEF TO
THE REGION IS ANTICIPATED.
* MONDAY...LOW CONFIDENCE.
MONDAY IS LOOKING WARM BUT STILL UNCERTAIN ON PRECIP CHANCES AS THE
PATTERN WILL BE FOCUSED ON IF THE RIDGE WILL BUILD OR NOT.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH 12Z...WIDESPREAD IFR/LIFR CONDITIONS IN STRATUS AND
FOG...ALTHOUGH SOME MVFR IN THE CT VALLEY. DENSE FOG CONFINED TO
THE S COAST. SCT SHOWERS AND ISOLD TSTM NE CT THROUGH SE MA.
TODAY...MODERATE CONFIDENCE. IFR/LIFR STRATUS AND FOG WILL
IMPROVE TO VFR BY MIDDAY...BUT AREAS OF IFR WILL LIKELY PERSIST
ALONG THE IMMEDIATE S COAST AND ESPECIALLY THE ISLANDS INTO THE
AFTERNOON. CHANCE OF A FEW THUNDERSTORMS IN THE AFTERNOON. SW
GUSTS TO 25 KT POSSIBLE RI AND SE MA DURING THE AFTERNOON.
TONIGHT...MODERATE CONFIDENCE. MAINLY VFR...BUT IFR CONDITIONS
POSSIBLE INTO THE EVENING ACROSS OUTER CAPE/ISLANDS.
WEDNESDAY...HIGH CONFIDENCE. VFR CIGS. NW GUSTS TO 25 KT.
KBOS TAF...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN TIMING
OF IMPROVEMENT TO VFR.
KBDL TAF...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN TIMING
OF IMPROVEMENT TO VFR.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...HIGH CONFIDENCE.
THURSDAY-FRIDAY...VFR. LIGHT AND VARIABLE WINDS. SEA BREEZES
POSSIBLE ON BOTH DAYS.
SATURDAY...VFR/MVFR WITH AN INCREASE IN SHOWERS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TUESDAY NIGHT/...
TONIGHT INTO TOMORROW...MODERATE CONFIDENCE.
LEFTOVER SWELL FROM ANA WILL BEGIN TO BUILD ALONG THE S COASTAL
WATERS LATE. REACHING A PEAK OF ABOUT 7-9 FT BY THE MID DAY
TOMORROW. SMALL CRAFT ADVISORIES CONTINUE FOR THIS THREAT.
OTHERWISE...WINDS REMAIN GENERALLY OUT OF THE S-SW UNTIL A COLD
FRONTAL PASSAGE TOMORROW LATE IN THE DAY...AT WHICH POINT THEY
SHIFT W.
THERE IS THE LOW THREAT FOR SOME THUNDERSTORMS...MAINLY ACROSS THE
E WATERS LATE IN THE DAY TOMORROW. FOG/STRATUS WILL ONCE AGAIN
YIELD NEAR ZERO VSBYS ACROSS THE WATERS TONIGHT INTO TOMORROW.
TOMORROW NIGHT...HIGH CONFIDENCE.
SLOW IMPROVEMENT AS WINDS SHIFT TO THE W. ANY SHOWERS/STORMS WILL
END AND SCOUR OUT THE LEFTOVER FOG. SEAS WILL ALSO GRADUALLY
DECLINE SUCH THAT SMALL CRAFT ADVISORIES MAY BE DROPPED BY THE
EARLY MORNING HOURS.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE CONFIDENCE.
WEDNESDAY...LINGERING 5FT SEAS WILL CONTINUE ON WED. HOWEVER GUSTS
WILL BE ON THE INCREASE TO 25 KTS ESP ACROSS THE INTERIOR
WATERS...SCA WILL BE NEEDED.
THURSDAY-FRIDAY...HIGH PRESSURE BUILDS OVER THE WATERS. WINDS AND
SEAS WILL BE BELOW SMALL CRAFT CRITERIA.
SATURDAY...WARM FRONT WILL PUSH OVER THE WATERS INCREASING PRECIP
CHANCES. BUT BOTH WINDS AND SEAS WILL REMAIN BELOW SCA.
&&
.FIRE WEATHER...
TOMORROW...TEMPERATURES MAY RISE TO NEAR 90 IN THE LOWER CT
VALLEY OF MA AND CT WITH DWPTS HOLDING IN THE 50S AND 60S. THERE
IS THE POSSIBILITY THEREFORE...THAT MIN RH VALUES WILL FALL TO
AROUND 25-35 PERCENT IN PORTIONS OF SW MA DURING THE DAY. SW WINDS
WILL GUST 25-30 MPH AT TIMES BY THE AFTERNOON. ALSO...THERE IS THE
THREAT FOR THUNDERSTORMS AND ACCUMULATING RAINFALL...BUT THESE
WILL GENERALLY BE HIT OR MISS AND WILL NOT PROVIDE THE WIDESPREAD
RAINFALL THAT MUCH OF THE REGION REQUIRES. A FIRE WEATHER WATCH
WILL BE ISSUED FOR SW PORTIONS OF MA DUE TO THE COLLOCATION OF
DRIEST RH VALUES...HIGHEST WINDS AND LOWEST THREAT FOR RAINFALL.
WEDNESDAY...A HIGHER RISK FOR FIRE WEATHER DEVELOPMENT IS EXPECTED
ON WEDNESDAY...HOWEVER IT WILL BE DEPENDENT ON PRECIP CHANCES OVER
THE NEXT 24-48 HOURS. SECONDARY COLD FRONT WILL PUSH THROUGH WED
MORNING ALLOWING FOR WINDS TO BE MORE OUT OF THE NW. THIS WILL
ALLOW FOR A DOWNSLOPING EFFECT...WHICH WILL INCREASE THE WIND
GUSTS AND LOWER DEWPOINTS. RIGHT NOW BELIEVE THAT RH VALUES WILL
DROP TO AROUND 30 PERCENT ACROSS MUCH OF THE REGION WITH NW WINDS
GUSTING TO NEAR 30 MPH. ONLY DIFFERENCE COMPARED TO THE PREVIOUS
DAYS IS HIGH TEMPS WILL WARM ONLY INTO THE UPPER 60S. HOWEVER
APPEARS THAT THERE WILL BE A GOOD AMOUNT OF SUNSHINE ACROSS MOST
OF THE REGION. WILL NEED TO CONTINUE TO MONITOR WEDNESDAY FOR
POSSIBLE HEADLINES.
THURSDAY AND FRIDAY...DRY WEATHER CONDITIONS WILL CONTINUE WITH RH
VALUES DROPPING WELL INTO THE 20 PERCENT LEVEL AND WITH FULL
SHINE. SINCE HIGH PRESSURE WILL BE OVERHEAD WIND WILL BE LIGHT AND
VARIABLE...GUSTS COULD REACH 10-15 MPH.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR MAZ018>024.
FIRE WEATHER WATCH FROM NOON EDT TODAY THROUGH THIS EVENING
FOR MAZ008>012.
RI...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR RIZ005>008.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 8 PM EDT THIS
EVENING FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
ANZ254>256.
&&
$$
SYNOPSIS...DOODY/DUNTEN
NEAR TERM...KJC
SHORT TERM...DOODY
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...DOODY/DUNTEN
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS LINCOLN IL
329 AM CDT TUE MAY 12 2015
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT TUE MAY 12 2015
07Z/2AM SURFACE ANALYSIS SHOWS 1001MB LOW OVER THE NORTHERN GREAT
LAKES WHILE A 1025MB HIGH BUILDS INTO THE CENTRAL PLAINS. PRESSURE
GRADIENT BETWEEN THESE TWO FEATURES WILL REMAIN TIGHT ENOUGH TO
PRODUCE BRISK WESTERLY WINDS ACROSS CENTRAL ILLINOIS TODAY.
SUSTAINED WINDS WILL GENERALLY BE IN THE 10 TO 15 MPH RANGE...BUT
GUSTS COULD REACH 25 TO 30 MPH AS MIXING TAKES PLACE LATER THIS
MORNING. LATEST VWP NETWORK SHOWS 925MB WINDS OF 40 TO 45 MPH AND
THINK SOME OF THIS HIGHER MOMENTUM AIR WILL GET MIXED DOWN TO THE
SURFACE ONCE MORNING INVERSION IS BROKEN. PRESSURE GRADIENT WILL
TEND TO RELAX AS THE DAY PROGRESSES...SO GUSTS WILL BEGIN TO SLOWLY
SUBSIDE BY MID-AFTERNOON. LOW CLOUDS CURRENTLY ALONG/NORTH OF A
RUSHVILLE TO BLOOMINGTON LINE WILL LIFT NORTHEASTWARD AND CLEAR OUT
OF THE AREA BY MID-MORNING...FOLLOWED BY MOSTLY SUNNY SKIES ACROSS
THE BOARD FOR THE REMAINDER OF THE DAY. AFTERNOON HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS...WITH READINGS
ONLY RISING INTO THE LOWER TO MIDDLE 60S.
&&
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 329 AM CDT TUE MAY 12 2015
HIGH PRESSURE WILL BUILD EASTWARD INTO THE MIDWEST TONIGHT...WITH
THE RIDGE AXIS EXPECTED TO BE POSITIONED RIGHT OVER ILLINOIS BY 12Z
WED. CLEAR SKIES AND LIGHT WINDS BENEATH THE RIDGE WILL ALLOW
EXCELLENT RADIATIONAL COOLING OF THE DRY AIRMASS TO TAKE
PLACE...RESULTING IN OVERNIGHT LOW TEMPERATURES IN THE LOWER TO
MIDDLE 40S. MAY EVEN SEE A FEW UPPER 30S IN FAVORED LOW-LYING
RURAL AREAS. THE HIGH WILL BEGIN TO SHIFT OFF TO THE EAST ON
WEDNESDAY...HOWEVER LOW-LEVEL FLOW WILL MAINTAIN A DISTINCT
EASTERLY COMPONENT. AS A RESULT...HIGH TEMPERATURES WILL REMAIN ON
THE COOL SIDE IN THE UPPER 60S TO AROUND 70 DEGREES.
UPPER HEIGHTS BEGIN TO RISE SIGNIFICANTLY BY THURSDAY AS DEEP UPPER
LOW OVER THE GULF OF ALASKA DROPS SOUTHEASTWARD AND REACHES THE
CALIFORNIA COAST...RESULTING IN DOWNSTREAM RIDGING ACROSS THE
CENTRAL AND EASTERN CONUS. A WEAK DISTURBANCE NOTED ON LATEST WATER
VAPOR IMAGERY OFF THE COAST OF SOUTHERN CALIFORNIA WILL GET EJECTED
NORTHEASTWARD BY THE DIGGING WEST COAST TROUGH...WITH THIS FEATURE
TRACKING INTO THE GREAT LAKES BY FRIDAY. MODELS ARE IN GOOD
AGREEMENT WITH THE TRACK AND TIMING OF THIS WAVE...WITH SOME MINOR
DISCREPANCIES ON HOW QUICKLY TO SPREAD PRECIP INTO ILLINOIS. GIVEN
INITIALLY VERY DRY AIRMASS IN PLACE BENEATH THE SURFACE
HIGH...PREFER A SLOWER ARRIVAL OF PRECIP. AS A RESULT...HAVE GONE
WITH A DRY FORECAST THROUGH THURSDAY MORNING EAST OF I-55 WITH LOW
CHANCE POPS DELAYED UNTIL AFTERNOON. FURTHER WEST...RAIN CHANCES
WILL INCREASE TO LIKELY ACROSS THE ILLINOIS RIVER VALLEY BY
AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS
MUCH OF THE AREA THURSDAY NIGHT...WITH THE BEST RAIN CHANCES FOCUSED
NORTH OF THE I-70 CORRIDOR. ONCE THE SHORT-WAVE SHIFTS INTO THE
GREAT LAKES...FORCING FOR ADDITIONAL PRECIP BECOMES MUCH WEAKER
FRIDAY AND SATURDAY. SEVERAL MODELS ARE HINTING THAT ANOTHER
WEAK WAVE EMBEDDED WITHIN THE SOUTHWESTERLY FLOW MAY ENHANCE
SHOWERS ACROSS SOUTHERN ILLINOIS INTO THE OHIO RIVER
VALLEY...HOWEVER VERY LITTLE FOCUS FOR ORGANIZED CONVECTION EXISTS
FURTHER NORTH ACROSS THE REMAINDER OF THE AREA. AS A
RESULT...WILL ONLY CARRY LOW CHANCE POPS THROUGH THE PERIOD.
DEEP UPPER LOW OVER CALIFORNIA WILL GRADUALLY EJECT NORTHEASTWARD
LATE IN THE WEEKEND. MODELS ARE IN GOOD AGREEMENT WITH THIS PROCESS
THROUGH 144 HOURS...THEN SOLUTIONS BEGIN TO DIVERGE AFTER THAT.
BOTH THE GFS AND ECMWF SHOW THE LOW TRACKING INTO THE DAKOTAS BY
SUNDAY EVENING...WITH CONVECTION DEVELOPING ALONG A TRAILING COLD
FRONT ACROSS THE PLAINS. THE ECMWF THEN BECOMES MORE PROGRESSIVE
WITH THE WAVE...AS IT OPENS UP AND PUSHES EASTWARD INTO THE NORTHERN
GREAT LAKES BY MONDAY. MEANWHILE...THE GFS KEEPS THE LOW CLOSED
LONGER AND IS THUS SLOWER WITH ITS EASTWARD TRACK. THIS MAKES A BIG
DIFFERENCE WITH TIMING OF ASSOCIATED COLD FRONT...AS GFS LINGERS
THIS BOUNDARY AND RAIN CHANCES UNTIL TUESDAY. SINCE OVERALL
SYNOPTIC PATTERN HAS BEEN PROGRESSIVE OVER THE PAST WEEK AND THE GEM
SUPPORTS THE ECMWF...WILL BE GOING WITH THE FASTER ECMWF/GEM
SOLUTION IN THE EXTENDED. AS A RESULT...WILL BRING LIKELY POPS INTO
THE FAR WESTERN CWA SUNDAY AFTERNOON...THEN FURTHER EAST ACROSS THE
REMAINDER OF THE AREA SUNDAY NIGHT. WILL THEN BEGIN TO SHIFT THE
RAIN CHANCES OUT OF THE PICTURE ON MONDAY...WITH DRY WEATHER
RETURNING MONDAY NIGHT AND TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1154 PM CDT MON MAY 11 2015
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS. WRAP-
AROUND CLOUDS CONTINUE TO MOVE ACROSS THE NORTHERN THIRD OF THE
STATE WITH BROKEN TO OVERCAST CLOUDS OCCURRING AT PIA. THESE
CLOUDS SHOULD REACH BMI SO WILL HAVE BROKEN TO OVERCAST CLOUDS AT
BOTH SITES BUT HAVE A TEMPO GROUP FOR BMI FOR FIRST SEVERAL HOURS
OF TAF FOR SCATTERED CLOUDS. OTHER SITES WILL JUST SEE SCATTERED
CLOUDS OVERNIGHT AND THROUGH MOST OF THE DAY. HRRR MODEL SHOWS THE
POSSIBILITY OF SOME BROKEN CIGS REACHING CMI IN THE MORNING SO
WILL HAVE TEMPO GROUP TO COVER THAT IN THE MORNING. ALL SITES WILL
EITHER REMAIN SCATTERED OR SCATTER OUT DURING THE MORNING HOURS
AND THEN BECOME CLEAR LATE MORNING TO EVENING HOURS. WEST WINDS
WILL CONTINUE AND THEN BECOME NORTHWEST TOMORROW EVENING. GUSTY
WINDS ARE EXPECTED AGAIN TOMORROW.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1154 PM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 904 PM CDT MON MAY 11 2015
WRAP-AROUND CLOUDS CONTINUE TO SLOWLY MAKE THEIR WAY INTO THE
AREA THIS EVENING WITH THE THICKEST CLOUDS BEING ACROSS THE
NORTHERN THIRD OF THE CWA. STILL COULD GET SOME CLOUDS ACROSS THE
I-72 CORRIDOR, BUT SHOULD REMAIN PARTLY CLOUDY OVERNIGHT.
REMAINDER OF THE FORECAST LOOKS FINE WITH LOWS IN THE MID 40S TO
LOWER 50S. WINDS SHOULD STAY UP A TAD AS WELL WITH GUSTS STILL
SHOWING UP AT SOME SITES. WILL MAKE SOME ADJUSTMENTS TO CLOUD
COVER AND WINDS IN THE GRIDS. WILL SEND AN UPDATE SHORTLY, THOUGH
THERE WILL PROBABLY NOT BE MUCH CHANGE IN THE WORDED FORECAST.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 255 PM CDT MON MAY 11 2015
A COLD FRONT DELINEATED BY A THIN LINE OF SHOWERS EXTENDED FROM JUST
WEST OF CHICAGO TO JUST EAST OF BLOOMINGTON AND TAYLORVILLE. THIS
FRONT WILL PUSH EAST TO THE IL/IN BORDER BY 00Z/7 PM WITH ISOLATED
SHOWERS POSSIBLE ALONG AND AHEAD OF IT THE REST OF THE EASTERN IN
EASTERN IL. ISOLATED THUNDERSTORMS SHOULD MOSTLY STAY EAST OF
CENTRAL IL OVER INDIANA REST OF TODAY WHILE SEVERE STORMS STAY OVER
OHIO AND EASTERN PARTS OF IN/KY INTO EARLY EVENING. OTHERWISE DRY
CONDITIONS EXPECTED TONIGHT INTO TUE ACROSS CENTRAL AND SOUTHEAST IL
ALONG WITH BREEZY AND COOLER CONDITIONS. LOW CLOUDS WERE DECREASING
BEHIND THE COLD FRONT WEST OF I-55 AT MID AFTERNOON AND EXPECT THESE
CLOUDS TO CONTINUE TO DECREASE OVER EASTERN IL LATE THIS AFTERNOON
AND EARLY EVENING. ANOTHER AREA OF LOW CLOUDS OVER IA AND NW MO WAS
TRACKING EASTWARD AND WILL SKIRT ACROSS THE IL RIVER VALLEY BY THIS
EVENING SO HAVE MORE CLOUDS OVER NORTHERN/NW COUNTIES TONIGHT. THE
SOUTHERN/SE EDGE OF THESE CLOUDS IS DIURNALLY ENHANCED SO MAY SEE
THIS DISSIPATE AFTER SUNSET. 1003 MB SURFACE LOW PRESSURE OVER
CENTRAL MN WILL TRACK EASTWARD ACROSS NORTHERN MI OVERNIGHT AND
FAIRLY TIGHT PRESSURE GRADIENT TO REMAIN OVER CENTRAL IL INTO TUE.
SW WINDS OF 15 TO 25 MPH AND GUSTS OF 25 TO 30 MPH THIS AFTERNOON TO
SHIFT MORE WESTERLY DURING THE NIGHT AND DIMINISH TO 10-17 MPH AFTER
SUNSET WITH GUSTS 18-25 MPH THIS EVENING.
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 255 PM CDT MON MAY 11 2015
A COUPLE COOLER DAYS, ALTHOUGH NOT AS COOL AS ANTICIPATED A FEW DAYS
AGO, ARE EXPECTED TUESDAY AND WEDNESDAY. A SPRAWLING SURFACE HIGH
WILL BUILD ACROSS THE AREA DURING THE PERIOD, WITH THE UPPER LEVEL
FLOW QUICKLY TRANSITIONING FROM WEAK TROFFING TO A BUILDING RIDGE.
THIS SCENARIO IS ALSO SUPPORTIVE OF DRY WEATHER CONDITIONS.
HOWEVER, CONDITIONS FLIP RATHER QUICKLY BACK TO WARM AND
UNSETTLED AFTER THE MIDDLE OF THE WEEK. A SYSTEM CURRENTLY DIVING
DOWN THE WEST COAST WILL CARVE OUT A NEW WESTERN U.S. TROF, WHICH
WILL HELP DEVELOP A DOWNSTREAM EASTERN U.S. RIDGE. DISTURBANCES
EJECTING OUT OF THIS TROF WILL CAUSE PERIODIC SHOWERS/STORMS
ACROSS CENTRAL AND SOUTHEAST ILLINOIS FOR THE END OF THE WEEK AND
THE WEEKEND, MUCH AS WAS SEEN THIS PAST WEEKEND. TEMPERATURES
SHOULD ALSO TREND WELL ABOVE NORMAL, WITH DAYTIME HIGHS HEADING
BACK TOWARD THE 80S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1154 PM CDT MON MAY 11 2015
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS. WRAP-
AROUND CLOUDS CONTINUE TO MOVE ACROSS THE NORTHERN THIRD OF THE
STATE WITH BROKEN TO OVERCAST CLOUDS OCCURRING AT PIA. THESE
CLOUDS SHOULD REACH BMI SO WILL HAVE BROKEN TO OVERCAST CLOUDS AT
BOTH SITES BUT HAVE A TEMPO GROUP FOR BMI FOR FIRST SEVERAL HOURS
OF TAF FOR SCATTERED CLOUDS. OTHER SITES WILL JUST SEE SCATTERED
CLOUDS OVERNIGHT AND THROUGH MOST OF THE DAY. HRRR MODEL SHOWS THE
POSSIBILITY OF SOME BROKEN CIGS REACHING CMI IN THE MORNING SO
WILL HAVE TEMPO GROUP TO COVER THAT IN THE MORNING. ALL SITES WILL
EITHER REMAIN SCATTERED OR SCATTER OUT DURING THE MORNING HOURS
AND THEN BECOME CLEAR LATE MORNING TO EVENING HOURS. WEST WINDS
WILL CONTINUE AND THEN BECOME NORTHWEST TOMORROW EVENING. GUSTY
WINDS ARE EXPECTED AGAIN TOMORROW.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AUTEN
SHORT TERM...07
LONG TERM...BAK
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
400 AM EDT TUE MAY 12 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA LATE TODAY. HIGH PRESSURE
RETURNS WEDNESDAY AND THURSDAY...THEN PUSHES OFFSHORE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE REMNANTS OF ANA HAVE PUSHED WELL OFF THE MID-ATLANTIC COAST
THIS MORNING. THE NEXT FEATURE TO IMPACT THE LOCAL AREA IS A COLD
FRONT CURRENTLY MAKING ITS WAY THROUGH THE OH VALLEY...AND
STRETCHING SOUTHWARD TO THE LOWER MS VALLEY. WARM/HUMID SW FLOW IN
PLACE THIS MORNING IS MAKING IT FEEL MORE LIKE MID-SUMMER WITH
TEMPS GENERALLY IN THE MID 60S TO MID 70S AT THIS HOUR. THE
CURRENT RADAR SCANS SHOWS THAT THE CONVECTION FROM LAST EVENING
HAS WANED. HOWEVER...A NEW ROUND OF SHWR ACTIVITY STRETCHING FROM
NEAR LYNCHBURG TO MARTINSVILLE IS POISED TO MAKE A RUN AT OUR
EASTERN PIEDMONT COUNTIES BY AROUND DAYBREAK. WILL CARRY SLIGHT
CHC POPS WESTERN AREAS THRU AROUND 9 AM TO ACCOUNT FOR THIS
POSSIBILITY. LATEST HRRR APPEARS A BIT ROBUST WITH PCPN MAKING IT
ALL THE WAY TO RICHMOND...BUT DOES SUPPORT THE AFOREMENTIONED
SLIGHT CHC POPS.
THE COLD FRONT CONTINUES TO MOVE EAST THROUGH THE DAY...REACHING
EASTERN PORTIONS OF THE FA AROUND 00Z. AHEAD OF THE FRONT...MODELS
ARE IN GOOD AGREEMENT SHOWING A PRE-FRONTAL TROUGH SHARPENING
ACROSS THE PIEDMONT BY 18Z WITH DEEP LAYERED WSW FLOW BRINGING
DRIER AIR (AND SIGNIFICANT LOWERING OF DEW POINTS) INTO THE
REGION. THE BEST MOISTURE AHEAD OF THE APPROACHING COLD FRONT IS
SHOWN TO QUICKLY SHIFT EAST INTO EASTERN AREAS THIS AFTN/EVE...
ESPECIALLY SE VA AND NE NC. MODEL SOUNDINGS SHOW A STRONG CAP DEVELOPING
BETWEEN 6-8KFT DURING THE AFTN HOURS ALONG AND NW OF A LINE FROM
AVC-PTB-WAL...WHICH WILL INHIBIT CONVECTION. SLOWER DEEP LAYERED
DRYING AND A WEAKER CAP IN SE VA/NE NC DURING THE AFTN/EARLY EVE
MAY RESULT IN POSSIBLE ISOLD/SCT CONVECTION AT TIME OF PEAK
HEATING. POPS WERE ADJUSTED ACCORDINGLY TO REFLECT A 30% POP FROM
ABOUT THE TRI-CITIES ON SOUTHEAST THIS AFTN/EVE. SPC HAS SE VA/NE
NC ONLY IN A MARGINAL RISK OF SVR WX LATER TODAY...AS THERE MAY BE
JUST ENOUGH INSTABILITY/MOISTURE IN PLACE (ML CAPE 1000-1500 J/KG)
COUPLED WITH MODEST SHEAR 20-30 KT TO PRODUCE AN ISOLD DAMAGING
WIND GUST THREAT. OTW...TODAY WILL BE SUMMER-LIKE WITH HIGH TEMPS
IN THE MID-UPR 80S ALONG THE IMMEDIATE COAST...UPR 80S-LOW 90S
ELSEWHERE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
SUBSTANTIAL DRYING TONIGHT THROUGH WED AS FLOW ALOFT BECOMES NW
AND SFC HIGH PRESSURE BUILDS TWD THE FA FROM THE GREAT LAKES. LOW
TEMPS TONIGHT FROM THE MID-UPR 50S...EXCEPT LOW 60S SE. SUNNY AND
LESS HUMID WED AS SFC HIGH PRESSURE CONTINUES TO BUILD INTO THE
REGION FROM THE NW. HIGH TEMPS RANGING FROM THE MID 60S-LOW 70S
ALONG THE COAST...MID-UPR 70S INLAND. DRY/PLEASANT WX WED NIGHT/THU
W/ LGT/VRB WINDS AND CLEAR-PTCLDY SKY. LOW TEMPS WED NIGHT FROM
THE MID-UPR 40S INLAND TO THE MID 50S AT THE COAST. HIGH TEMPS THU
65 TO 70F AT THE BEACHES TO THE LOW-MID 70S INLAND.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE RESIDES OVER THE AREA FOR ONE MORE NIGHT...KEEPING
LOW TEMPERATURES IN THE LOWER 50S INLAND AND MID-UPPER 50S AT THE
IMMEDIATE COAST. HIGH PRESSURE THEN SLIDES OFF THE COAST DURING
THE DAY ON FRIDAY...ALLOWING WARM AIR ADVECTION PROCESSES TO
COMMENCE IN RETURN SWLY FLOW. GULF MOISTURE WILL GRADUALLY BE
PULLED INTO THE REGION AROUND THE BACK SIDE OF A LARGE-SCALE HIGH
PRESSURE OVER THE SOUTHEAST COAST...THUS INTRODUCING PRECIPITATION
BACK INTO THE FORECAST BEGINNING FRIDAY AFTERNOON. UNSETTLE
CONDITIONS THEN PREVAIL THROUGH THE UPCOMING WEEKEND AND INTO
EARLY NEXT WEEK WITH NO SIGNIFICANT UPSTREAM FEATURES TO PUSH THE
HIGH SOUTH OR EAST. EXPECT PERIODS OF OFF AND ON RAIN SHOWERS/AFTN
THUNDERSTORMS (30-40 PERCENT) DURING THIS TIMEFRAME. HIGHS SLOWLY
REBOUND TO SLIGHTLY ABOVE SEASONAL NORMALS THROUGH THE WEEKEND AS
THE SFC HIGH MOVES OFFSHORE. EXPECT HIGHS 75-85 (5-7 DEGREES
COOLER AT THE IMMEDIATE COAST) AND LOWS IN THE LOW-MID 60S.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
THE REMNANT LOW FROM ANA IS NOW IN VICINITY OF THE CENTRAL NJ
COAST AS OF 06Z...AND IS IN THE PROCESS OF BECOMING ABSORBED BY
LOW PRESSURE OVER THE GREAT LAKES. A COLD FRONT ASSOCIATED WITH
THE GREAT LAKES LOW IS BACK OVER THE OHIO VALLEY. THE LOCAL AREA
IS NOW WITHIN A REGION OF SW FLOW AHEAD OF THE COLD FRONT. BKN
CIGS AOA 6KFT COMBINED WITH A 6-10KT SW WIND SHOULD INHIBIT FOG
DEVELOPMENT OVERNIGHT. THE BEST CHC FOR MVFR VSBY IS AT SBY WHERE
THE DEWPOINT DEPRESSION IS 2F...MEANWHILE OTHER LOCATIONS ARE
8-10F. ISOLATED -SHRA/TSRA WILL LINGER OVERNIGHT...BUT THE
PROBABILITY OF A DIRECTLY AFFECTING A TAF SITE IS VERY LOW.
OTHERWISE...EXPECT BREEZY CONDITIONS TO DEVELOP LATER THIS
MORNING AHEAD OF THE COLD FRONT WITH A SW WIND AVERAGING
12-15KT...WITH GUSTS OF 20-25KT THROUGH THE AFTERNOON. A FEW
-SHRA/TSRA ARE POSSIBLE THIS AFTERNOON MAINLY OVER SE VA/NE NC.
THE COLD FRONT SWEEPS THROUGH THE AREA THIS EVENING...WITH HIGH
PRESSURE PREVAILING MIDWEEK. HIGH PRESSURE MOVES OFFSHORE FRIDAY
AND SATURDAY.
&&
.MARINE...
THE REMNANT LOW OF ANA ABSORBS INTO LOW PRESSURE TRACKING ACROSS THE
SAINT LAWRENCE VALLEY TODAY. THIS WILL DRAG A COLD FRONT TOWARD THE
REGION TODAY...WITH THE BOUNDARY CROSSING THE COAST THIS EVENING.
EXPECT A SW WIND TO AVERAGE ~15KT OVER THE BAY EARLY TODAY WITH 15-
20KT OVER THE OCEAN...BEFORE RELAXING TO 10-15KT THIS AFTERNOON. A
SHORT DURATION PERIOD OF ~20KT IS POSSIBLE ACROSS THE LOWER
BAY/LOWER JAMES AROUND 10-12Z BUT SHOULD NOT BE LONG ENOUGH TO
WARRANT AN SCA. ADDITIONALLY...A FEW TSTMS ARE POSSIBLE WITH THE
FRONTAL PASSAGE THIS AFTERNOON AND EVENING. MODEST CAA ARRIVES LATER
TONIGHT INTO EARLY WEDNESDAY...ESPECIALLY ACROSS THE NRN HALF OF THE
AREA IN THE WAKE OF THE FRONT. AN SCA HAS BEEN ISSUED FOR THE BAY
FOR LATE TONIGHT INTO WEDNESDAY MORNING. THE SCA N OF PARRAMORE
ISLAND HAS BEEN EXTENDED THROUGH TODAY AS SEAS COULD LINGER ~5FT
(ESPECIALLY OUT NEAR 20NM)...AND CONTINUING TONIGHT INTO WEDNESDAY
MORNING FOR THE CAA SURGE. A SECONDARY NORTHERLY SURGE WEDNESDAY
NIGHT HAS THE POTENTIAL TO PRODUCE MARGINAL SCA CONDITIONS...BEFORE
HIGH PRESSURE SETTLES INTO THE REGION THURSDAY AND THURSDAY NIGHT.
HIGH PRESSURE MOVES OFFSHORE FRIDAY AND SATURDAY ALLOWING THE WIND
TO RETURN TO SSW. SEAS SHOULD AVERAGE 2-4FT LATER WEDNESDAY THROUGH
SATURDAY...WITH WAVES IN THE BAY AVERAGING 1-3FT.
&&
.CLIMATE...
RATHER HOT TUE...WITH A GOOD CHANCE AT SEEING OUR 1ST 90-
DEGREE DAY OF THE YEAR:
MEAN DATE OF 1ST 90-DEGREE DAY (1981-2010 CLIMATOLOGY):
RICHMOND....MAY 13TH
NORFOLK.....MAY 17TH
SALISBURY...MAY 27TH
ELIZ CITY...MAY 25TH
RECORD HIGHS POSSIBLE TUE...RECORDS ARE LISTED BELOW FOR MAY 12TH:
RICHMOND....92 (1956)
NORFOLK.....92 (1881)
SALISBURY...93 (1914)
ELIZ CITY...90 (2001)
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ650-
652-654.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM
SHORT TERM...ALB/JDM
LONG TERM...BMD
AVIATION...AJZ
MARINE...AJZ
CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
139 AM EDT TUE MAY 12 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 421 PM EDT MON MAY 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE MID LEVEL LOW THAT WAS
OVER WRN NEBRASKA/SD 24HRS AGO NOW CENTERED IN WCNTRL MN. AHEAD OF
FEATURE...WARM CONVEYOR BELT MOISTURE RIBBON EXTENDS FROM THE LWR
MISSISSIPPI VALLEY TO THE WRN GREAT LAKES. RESULT HAS BEEN NMRS SHRA
SPREADING ACROSS THE FCST AREA TODAY. A FEW TSTMS WERE NOTED THIS
MORNING OVER THE W HALF OF UPPER MI. AT THE SFC...LOW PRES LOCATED
IN CNTRL MN IS BECOMING LESS WELL-DEFINED WITH TENDENCY FOR LOW PRES
REDEVELOPMENT AT THE TRIPLE POINT FARTHER E. OCCLUDED FRONT IS
APPROACHING THE MI/WI BORDER AS OF 20Z.
AS THE WARM CONVEYOR MOISTURE RIBBON TRANSLATES E...WIDESPREAD SHRA
NOW OVER THE E HALF OF THE FCST AREA WILL ALSO SHIFT E AND OUT OF
THE AREA IN THE NEXT FEW HRS. FOG AND SOME -DZ WILL PERSIST IN THE
UPSLOPE FLOW OFF LAKE SUPERIOR INTO THE KEWEENAW AND WRN PORTIONS OF
NCNTRL UPPER MI...AND A FEW SHRA MAY DEVELOP NEAR THE OCCLUDED FRONT
WHICH SHOULD LIFT INTO OR THRU MUCH OF CNTRL AND ERN UPPER MI THIS
EVENING. OTHERWISE...AS MID LEVEL LOW OPENS UP AND UPPER TROF MOVES
E INTO THE WRN GREAT LAKES TONIGHT...DEEPER MOISTURE WILL WRAP BACK
INTO THE AREA FROM THE N AND W. AIDED BY DEEP CYCLONIC FLOW...SHRA
WILL SPREAD BACK INTO THE FCST AREA...ESPECIALLY ACROSS THE W. AS
CAA INCREASES OVERNIGHT...FCST SOUNDINGS/WETBULB ZERO HEIGHTS
SUGGEST POTENTIAL FOR SNOW TO MIX WITH THE RAIN OVER THE HIGH
TERRAIN OF THE W LATE TONIGHT.
AS TROF CONTINUES TO SHIFT E TUE...DEEP LAYER QVECTOR DIVERGENCE
OVERSPREADS THE AREA WITH HEIGHTS BEGINNING TO RISE...MORE
SUBSTANTIALLY IN THE AFTN. THIS WILL TEND TO DIMINISH THE WRAP
AROUND PCPN WITH TIME...BUT THIS WILL BE COUNTERACTED BY SHARP
CYCLONIC FLOW AND CONSIDERABLE LOW TO MID LEVEL MOISTURE THAT
LINGERS THRU THE DAY. THIS WILL RESULT IN PCPN BEING MOST PERSISTENT
IN THE AREAS THAT SEE UPSLOPING UNDER NW TO N WINDS. DOWNSLOPE AREAS
WILL SEE PCPN DIMINISH OR END. CONTINUED CAA WILL DROP 850MB TEMPS
TO -3 TO AS LOW AS -6C...AND THIS WILL RESULT IN RAIN MIXING WITH
SNOW...MAINLY OVER THE HIGHER TERRAIN OF THE W AND CNTRL. PCPN WILL
LIKELY CHANGE TO ALL SNOW AT LEAST FOR A TIME OVER THE HIGH TERRAIN
OF THE W HALF AS LOWEST 850MB TEMPS ARE FCST THERE. THAT AREA WILL
ALSO HAVE THE BEST CHANCE FOR A LITTLE SNOW ACCUMULATION ON GRASSY
SFCS. IT WILL BE AN UNSEASONABLY COLD DAY WITH TEMPS AROUND 20
DEGREES BLO NORMAL ACROSS THE W AND N WHERE TEMPS WILL STRUGGLE TO
GET MUCH ABOVE 40F. ACROSS THE SCNTRL...TEMPS MAY SNEAK INTO THE LWR
50S. BLUSTERY WINDS WILL ADD TO THE CHILL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 255 PM EDT MON MAY 11 2015
WILL STILL HAVE SOME LINGERING MAINLY SNOW SHOWERS /WITH A FEW RAIN
SHOWERS OR AREAS OF DRIZZLE MIXED IN/ TUESDAY NIGHT OVER THE N HALF
OF UPPER MI. THE BEST CHANCE OF PRECIP WILL BE N CENTRAL AS
FAVORABLE N-NNW WINDS RESIDE THERE FROM THE SFC-850MB. TEMPERATURES
WILL BE COOLING INTO THE LOW 30S OVERNIGHT...WITH LOCATIONS OVER THE
INTERIOR W HALF FALLING INTO THE MID 20S AS WINDS BECOME NEARLY CALM
AND DRIER AIR WORKS IN AND 850MB TEMPS BEGIN TO WARM SLIGHTLY FROM -
4 TO -6C...TO AROUND -3C.
HIGH PRESSURE WILL BE STRETCHING FROM HUDSON BAY THROUGH MANITOBA
AND MN...DOWN THROUGH THE MS VALLEY AT 00Z WEDNESDAY. LOOK FOR THE
AREA OF HIGH PRESSURE TO BUILD ACROSS THE UPPER GREAT LAKES THROUGH
WEDNESDAY...WITH DRY WEATHER FIGURED INTO AT LEAST WEDNESDAY
EVENING. WAA WILL TAKE HOLD AT THE SFC ON MAINLY S WINDS OVER THE W
HALF OF THE CWA...WITH AFTERNOON HIGHS IN THE 50S FOR MOST LOCATIONS
/EXCLUDING THE COOLER N CENTRAL AND E
LAKE SUPERIOR SHORELINE/ AS 850MB TEMPS REBOUND TO AROUND 4C W TO 1C
E.
PRECIP COULD SLIDE IN AS EARLY AS LATE WEDNESDAY AFTERNOON SW /GFS
SOLUTION/. THIS WOULD BE ALONG THE SW AS AN INITIAL FRONTAL BOUNDARY
SHIFTS TO OUR N. THE MAIN CONCERN IS THAT THE LOWER LEVELS WILL BE
TOO DRY WITH THE SFC RIDGE STILL OVER MUCH OF THE AREA WITH THIS
BOUNDARY/SHORTWAVE ROUNDING THE 500MB RIDGE. WILL CONTINUE TO GO
WITH A MINIMAL PRECIP SOLUTION FOR THIS PERIOD. THE SFC HIGH WILL
SHIFT ACROSS THE ENTIRE GREAT LAKES REGION WEDNESDAY NIGHT...WITH
SLOWLY INCREASING S FLOW OVER UPPER MI PUSHING IN INCREASED MOISTURE
AS 850MB TEMPS RUMP TO AROUND 8C OVER THE SW.
THE APEX OF THE 500MB RIDGE WILL BE ACROSS THE AREA THURSDAY
AFTERNOON...WITH FCST MODELS INDICATING A NEARING EMBEDDED 500MB
TROUGH IN THE SW FLOW OVER THE N PLAINS AND W MN. THE GFS HAS A
DEEPER/WRAPPED UP SFC LOW OVER THE CENTRAL PLAINS OFF THE GFS IS NOT
QUITE A S STRONG AS THE ECMWF...ESPECIALLY THE PREVIOUS 11/06Z RUN.
THIS LEADS TO ONLY MODERATE CONFIDENCE IN THE FCST BEYOND THURSDAY.
THE DIFFERENCE SHOWS UP WELL IN THE MODEL QPF...WITH THE 11/06Z GFS
SHOWING 24HR PRECIP OF 0.75-1.45IN BY 00Z SATURDAY. THE 11/00Z ECMWF
ON THE OTHER HAND RANGES FROM LESS THAN 0.10IN ACROSS THE KEWEENAW
PENINSULA...TO 0.5IN OVER FAR S MENOMINEE CO. THIS WILL BE AS THE
SFC LOW OFF THE GFS TRACKS FROM THE CENTRAL PLAINS TO N LAKE MI BY
00Z SATURDAY. THE CANADIAN THE ECMWF KEEP A RIDGE ACROSS LAKE
SUPERIOR AND MUCH OF UPPER MI DURING THE SAME TIME PERIOD. ON A
POSITIVE NOTE...THE 11/12Z GFS CAME IN AT LEAST A LITTLE LESS
INTENSE WITH THE SFC LOW...AND DROPS ABOUT 1/2 AS MUCH PRECIP.
AN ADDITIONAL LOW DEVELOPING OFF THE N ROCKIES TOWARDS THE END OF
THE WORK WEEK WILL LIKELY BE SET UP ACROSS MT AND WY SATURDAY
MORNING...AND MOVE ACROSS THE DAKOTAS SATURDAY NIGHT...AND THE UPPER
GREAT LAKES ON MONDAY. THE 12Z RUNS HAVE BECOME MUCH MORE IN LINE
WITH THE SFC LOW TRACKING OVER E MN/FAR W LAKE SUPERIOR BY 06Z
MONDAY. THE RESULT IS AT LEAST MODERATE CONFIDENCE IN RAIN. WILL GO
WITH LIKELY PRECIP FOR SUNDAY NIGHT ACROSS MOST OF THE CWA. SO FOR
THE UPCOMING WEEKEND IT LOOKS TO BE MAINLY DRY SATURDAY...WITH WET
WEATHER APPROACHING SUNDAY AND POSSIBLY LINGERING INTO MONDAY AS THE
SFC LOW SLOWLY EDGES E OF THE CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 138 AM EDT TUE MAY 12 2015
A LOW PRES SYSTEM WILL MOVE E ACROSS THE UPPER GREAT LAKES TONIGHT
AND THEN E TO QUEBEC TUE. ABUNDANT LOW-LEVEL MOISTURE WILL GENERALLY
SUPPORT IFR TO LIFR CONDITIONS OVERNIGHT TONIGHT AND -SHRA AT
KIWD/KCMX/KSAW TONIGHT WITH THE LOWEST CONDITIONS OCCURRING AT
TERMINALS EXPERIENCING UPSLOPE WINDS. COLDER AIR WRAPPING INTO THE
AREA BEHIND THE LOW SHOULD BE COLD ENOUGH TO RESULT IN -SHRA MIXING
WITH OR CHANGING OVER TO -SHSN LATE TONIGHT/TUE MORNING. CHANGE OVER
TO ALL SNOW IS MORE LIKELY TO OCCUR AT KIWD/KCMX. DRIER AIR WORKING
IN BEHIND THE LOW LATE TUE AFTERNOON INTO TUE EVENING WILL END PCPN
AND ALLOW ALL THE TAF SITES TO IMPROVE TO MVFR BY TUE EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 PM EDT MON MAY 11 2015
ONGOING MARGINAL GALES OVER THE WRN PORTION OF LAKE SUPERIOR WILL
CONTINUE TO DIMINISH...FALLING BLO GALE FORCE EARLY THIS EVENING...
AS PRES GRADIENT WEAKENS AND WINDS BACK DUE TO LOW PRES SHIFTING
ACROSS UPPER MI AND ERN LAKE SUPERIOR. ON THE BACK SIDE OF THE
LOW...NNW WINDS WILL INCREASE TO 20-30KT ACROSS CNTRL AND ERN LAKE
SUPERIOR LATE TONIGHT/TUE MORNING. MAY SEE A FEW GALE FORCE GUSTS
TUE MORNING OVER SCNTRL LAKE SUPERIOR AROUND GRANITE ISLAND DUE TO
LOCAL COASTAL CONVERGENCE. WINDS WILL DIMINISH FROM W TO E TUE
AFTN/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU. AS THE HIGH PRES SHIFTS E AND A WEAK LOW PRES
PASSES BY TO THE S...WINDS MAY INCREASE SOME FOR THU NIGHT/FRI
BEFORE DIMINISHING AGAIN ON SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1210 AM EDT TUE MAY 12 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 328 PM EDT MON MAY 11 2015
A COLD FRONT WILL COME THROUGH THE AREA TONIGHT ENDING OVER A
WEEKS WORTH OF UNSEASONABLY WARM TEMPERATURES. THERE WILL BE
SHOWERS AND A FEW THUNDERSTORMS AHEAD OF THE COLD FRONT THIS
EVENING...THEN A FEW LIGHT RAIN SHOWERS TUESDAY AS CHILLY WESTERLY
WINDS KEEP AFTERNOON TEMPERATURES IN THE 50S. SKIES WILL BECOME
PARTLY CLOUDY TUESDAY NIGHT REMAIN SO ON WEDNESDAY. ANOTHER STORM
SYSTEM WILL BRING MORE SHOWERS AND POSSIBLY THUNDERSTORMS LATER
THIS WEEK INTO THE WEEKEND. IT WILL WARM UP AGAIN BY THE END TOO.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 328 PM EDT MON MAY 11 2015
THE MAIN ISSUE IS THE THREAT FOR SEVERE STORMS (NOT MUCH) THEN THE
CHANCE FOR LIGHT RAIN SHOWERS TUESDAY AND POSSIBLE FROST TOMORROW
NIGHT.
THE LATEST RAP MODEL SHOWS THE LOW LEVEL JET CORE LIFTING
NORTHEAST FROM SOUTHWEST LOWER MICHIGAN EARLY THIS AFTERNOON TO
THE THUMB AREA BY EARLY THIS EVENING. THE MOST UNSTABLE CAPE
(OVER 500 J/KG) STAYS JUST EAST OF OUR CWA LATE THIS AFTERNOON.
WHILE THERE IS GOOD DEEP LAYER SHEAR...THE RAIN COOLED AIR OVER
MOST OF OUR CWA WILL MITIGATE MOST OF THE SEVERE WEATHER THREAT.
POSSIBLY ISOLATED DAMAGING WINDS COULD HAPPEN OVER OUR EXTREME
SOUTHEAST COUNTIES EARLY THIS EVENING.
OTHERWISE THE AREA OF RAIN WILL MOVE OUT BY MID EVENING. THEN THE
DRY SLOT MOVES IN BEHIND THE COLD FRONT SO SKIES WILL CLEAR AT
LEAST PARTLY. WE THEN GET WRAP AROUND COLD AIR ADVECTION
INSTABILITY SHOWERS (MOSTLY SPRINKLES) TUESDAY AND IT WILL BE
BREEZY AND CHILLY WITH HIGHS ONLY IN THE 50S.
THE UPPER TROUGH MOVES OUT QUICKLY TUESDAY NIGHT ALLOWING FOR SOME
CLEARING. FROST IS POSSIBLE OVER NORTHERN AREAS WEDNESDAY MORNING.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 328 PM EDT MON MAY 11 2015
AS HIGH PRESSURE MOVES EAST THURSDAY LOW PRESSURE WILL MOVE TOWARD
THE GREAT LAKES. CONFIDENCE IS INCREASING THAT WE/LL SEE SOME
PRECIPITATION MOVE OVER THE CWA THURSDAY NIGHT AND FRIDAY. ADDED
THUNDER TO THE GRIDS FRIDAY AS LI/S FALL TO AROUND -2C AND CAPE
INCREASES TO 1K J/KG. MUCH OF THE PCPN WILL BE EAST OF THE CWA BY
SATURDAY AS THE SFC LOW MOVES AWAY. HOWEVER WE/LL KEEP LOW POPS IN
TO COVER THE UPPER TROUGH.
CHANCES FOR TSRA WILL INCREASE TOWARD THE BEGINNING OF NEXT WEEK AS
A STRONGER COLD FRONT MOVES TOWARD THE CWA. STRONG SOUTH FLOW AHEAD
OF IT WILL SEND ABUNDANT MOISTURE NORTHWARD AND CREATE SOME
INSTABILITY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1209 AM EDT TUE MAY 12 2015
PREDOMINATELY VFR OVERNIGHT BUT AROUND 12Z TUESDAY MVFR CIGS WILL
SPREAD IN FROM THE WEST AND PERSIST MUCH OF THE DAY. A FEW LIGHT
SHOWERS OR SPRINKLES ARE POSSIBLE BUT IF ANY REDUCTIONS TO VSBYS
OCCURRED IT SHOULD BE VERY BRIEF. CIGS ARE EXPECTED TO IMPROVE TO
VFR AGAIN TUESDAY NIGHT AFTER 00-02Z.
GUSTY SOUTHWEST TO WEST SFC WINDS OF 15 TO 25 KNOTS TONIGHT WILL
INCREASE TO 20 TO 30 KNOTS ON TUESDAY... RESULTING IN SOME LOW
LEVEL TURBULENCE. WINDS WILL DECREASE TUESDAY NIGHT AFTER 00-02Z.
&&
.MARINE...
ISSUED AT 328 PM EDT MON MAY 11 2015
THE STRONG WINDS BEHIND OUR SYSTEM WILL LEAD TO 4 TO 6 FOOT WAVES
AND WINDS TO 30 KNOTS BY MID MORNING TUESDAY. AS A RESULT I ISSUED
A SMALL CRAFT ADVISORY.
&&
.HYDROLOGY...
ISSUED AT 1222 PM EDT MON MAY 11 2015
ADDITIONAL RAINFALL AMOUNTS BETWEEN A QUARTER AND THREE QUARTERS OF
AN INCH WILL BE POSSIBLE MAINLY BEFORE MIDNIGHT TONIGHT. WE ARE
ISSUING ADVISORIES FOR THE SYCAMORE CREEK AT HOLT...WHICH SHOULD
CREST SHORTLY AFTER MIDNIGHT TONIGHT. CONFIDENCE IS HIGH THAT IT
WILL REMAIN BELOW FLOOD STAGE.
AFTER TONIGHT DRY CONDITIONS SHOULD PREVAIL UNTIL THURSDAY...WHEN
RAIN SHOWERS RETURN TO THE AREA. THIS SHOULD GIVE RIVER LEVELS
SOME TIME TO SUBSIDE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 6 PM EDT
THIS EVENING FOR LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...93
AVIATION...MEADE
HYDROLOGY...TJT
MARINE...WDM
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1237 AM CDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 734 PM CDT MON MAY 11 2015
UPDATED POPS AS CURRENT RADAR TRENDS SHOW PRECIPITATION INCREASING
IN COVERAGE AND INTENSITY ACROSS THE FORECAST AREA. AN AREA OF
CONVECTIVE SHOWERS WITH REFLECTIVITY VALUES OVER 40 DBZ HAS
DEVELOPED ABOUT 30 MILES NORTH OF DULUTH...ON THE LEADING EDGE OF
THE H50 LOW/VORT MAX AND AN REGION OF LOW LEVEL FRONTOGENESIS
DEPICTED IN THE LATEST RUC MESO ANALYSIS. ANTICIPATE ECHOES TO
CONTINUE TO INTENSIFY OVER THE IRON RANGE/ARROWHEAD AS THE VORT
MAX TRANSLATES EAST ACROSS THE FORECAST AREA. AT THIS TIME THE
PRECIP TYPE BEING REPORTED BY AUTOMATED STATIONS IS ALL RAIN.
HOWEVER...AS PROFILES COOL THROUGH THE EVENING THE RAIN IS
EXPECTED TO CHANGE OVER TO SNOW FOR AT LEAST THE NORTHERN PORTION
OF MN.
ALSO ADDED AREAS OF FOG ALONG SOUTH SHORE OF LAKE SUPERIOR WHERE
SURFACE OBSERVATIONS AND SPOTTERS HAVE REPORTED VISIBILITY OF LESS
THAN A HALF MILE AT TIMES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 328 PM CDT MON MAY 11 2015
A CLOSED AND NEARLY STACKED UPPER LOW OVER MINNESOTA WILL CONTINUE
SHOWERS OVER THE REGION TONIGHT AS IT SLOWLY MOVES EAST. THE
STRONGEST LIFT NORTH OF THE BAROCLINIC ZONE WILL BE IN NORTHERN
MINNESOTA BUT CANNOT RULE OUT SHOWERS ACROSS REST OF THE FORECAST
AREA. COLD AIR ADVECTION BEHIND THE LOW LATER TONIGHT COULD RESULT
IN SNOW SHOWERS. BUT WITH THE WET GROUND, DO NOT EXPECT MUCH
ACCUMULATION. THERE WILL BE A GRADUAL END TO ANY SHOWERS SLOWLY FORM
WEST TO EAST TUESDAY WITH SFC HIGH PRESSURE BUILDING OVER THE
AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 328 PM CDT MON MAY 11 2015
THE NORTHLAND CAN EXPECT A BIT OF WET PATTERN OVER THE NEXT WEEK
WITH SEVERAL OPPORTUNITIES FOR RAIN.
HIGH PRESSURE WILL BE OVER THE NORTHLAND TUESDAY NIGHT AND WILL MAKE
FOR A COOL AND RELATIVELY CLEAR NIGHT. TEMPERATURES WILL DIP INTO
THE LOWER 30S AND UPPER 20S. THERE WILL BE INCREASING CLOUD COVER
FROM THE WEST LATE TUESDAY NIGHT AND WEDNESDAY AS A MID LEVEL
FRONTOGENETICAL BAND MOVES INTO THE NORTHLAND. THIS FRONTOGENETICAL
BAND WILL LIKELY RESULT IN RAINS SHOWERS FOR PARTS OF THE NORTHLAND
WEDNESDAY AND WEDNESDAY NIGHT. THE SW FORECAST AREA HAS THE BEST
CHANCE OF RAIN.
A LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS WEDNESDAY NIGHT WILL
LIFT INTO THE NORTHERN PLAINS THURSDAY AND THURSDAY NIGHT. THE
MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THIS WILL BRING MORE RAIN
TO THE NORTHLAND THURSDAY INTO FRIDAY. THE SOUTHERN FORECAST AREA
HAS THE BEST CHANCE OF RAIN WITH THE PASSAGE OF THIS SYSTEM.
WEAK HIGH PRESSURE WILL GIVE ANOTHER SHORT BREAK BETWEEN WEATHER
SYSTEMS LATE FRIDAY AND SATURDAY. A LOW IN THE NORTHERN PLAINS WILL
LIFT A WARM FRONT INTO THE UPPER MIDWEST. THE GFS AND ECMWF ARE IN
RELATIVELY GOOD AGREEMENT THAT THE NORTHLAND WILL SEE SHOWERS AND
STORMS LATE SATURDAY INTO EARLY MONDAY WITH THE PASSAGE OF THIS
SYSTEM. THE SOUTHERN FORECAST AREA HAS THE BEST CHANCE OF SEEING
THUNDER SINCE THE WARM FRONT MIGHT GET SHUNTED SOUTH BECAUSE OF COOL
EASTERLY FLOW FROM LAKE SUPERIOR AND ONTARIO. HOWEVER...THERE COULD
BE ELEVATED CONVECTION NORTH OF THE WARM FRONT...BUT THOUGHT IT TOO
EARLY TO INCLUDE THUNDER OVER ALL OF THE NORTHLAND.
TEMPERATURES WILL REMAIN COOL FOR THE MIDDLE OF THE WEEK...BUT WILL
LIKELY REBOUND TO CLOSE TO NORMAL BY THIS WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1235 AM CDT TUE MAY 12 2015
WIDESPREAD RAIN/DRIZZLE...MIXING WITH SNOW AT TIMES...AND LIFR/IFR
CONDITIONS WILL PREVAIL OVERNIGHT. CEILINGS WILL GRADUALLY IMPROVE
FROM THE WEST THROUGH THE DAY AS DRIER AIR ASSOCIATED WITH
BUILDING HIGH PRESSURE FILTERS INTO THE REGION. HOWEVER...THE COLD
AIR MASS AND LINGERING MOISTURE WILL BE SUFFICIENT FOR INSTABILITY
SHOWERS INTO THE AFTERNOON. A FEW OF THE SHOWERS WILL BE CAPABLE
OF PRODUCING GUSTY NORTH WINDS TO 30 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 50 38 54 / 10 60 40 50
INL 30 56 40 58 / 10 0 50 50
BRD 37 52 46 59 / 10 60 50 60
HYR 31 56 43 61 / 10 40 30 50
ASX 32 52 39 57 / 10 40 40 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GRANING
SHORT TERM...CLC
LONG TERM...GROCHOCINSKI
AVIATION...CLC
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1130 PM MDT MON MAY 11 2015
AVIATION SECTION UPDATED
.DISCUSSION... UPDATE FORTHCOMING. SOUTHWEST FLOW ALOFT CONTINUES TO
BRING MOISTURE AND INSTABILITY TO SOUTHWEST MONTANA WHERE SCATTERED
SHOWERS SHOULD CONTINUE THROUGH THE NIGHT. BOTH THE HRRR AND RUC
ANALYSIS BRING SHOWERS AS FAR NORTH AS JUST ABOUT GREAT FALLS BY
12Z. TEMPERATURES OVERNIGHT LOOK ON TRACK.
&&
.AVIATION... UPDATED 0530Z. VFR CONDITIONS EXPECTED TONIGHT.
SOUTHWEST FLOW ALOFT AHEAD OF A LOW PRESSURE SYSTEM ALONG THE OREGON
COAST WILL PUSH EXTENSIVE MOISTURE INTO CENTRAL/SOUTHWEST MT
TONIGHT. THIS WILL RESULT IN WIDESPREAD MID-LEVEL CEILINGS
(GENERALLY IN THE 6000-10000 FT RANGE) AT ALL TAF SITES WITH
ISOLATED -SHRA VCNTY KHLN/KBZN DEVELOPING AROUND 09-12Z. SCATTERED
SHOWERS AND ISOLATED -TSRA BECOME MORE LIKELY FROM KHLN SOUTH TO THE
MT/ID BORDER BY MID-AFTN AS THE COASTAL LOW COMES INLAND AND BRINGS
ADDITIONAL MOISTURE AND INSTABILITY. BRIEF MVFR CEILINGS AND
MODERATE RAINFALL POSSIBLE NEAR KHLN/KBZN WITH ANY STRONGER
CONVECTIVE CELLS.
WARANAUSKAS
&&
.PREV DISCUSSION...ISSUED 259 PM MDT MON MAY 11 2015
MONDAY THROUGH WEDNESDAY...CONDITIONS WILL GENERALLY CHANGE TO A
WETTER PATTERN THROUGH THE MIDDLE OF THE WEEK AS SHORTWAVE TROUGHS
MOVE ONSHORE AND BEGIN TO BRING MOISTURE INTO THE REGION. SOME
SHOWERS OVER THE HIGHER TERRAIN WILL BE POSSIBLE THIS EVENING AS
THE FIRST SHORTWAVE MOVES INTO THE AREA. PRECIPITATION WILL BE
LIMITED WITH THIS SYSTEM WITH MOST OF THE SHOWERS OCCURRING OVER
THE ROCKY MOUNTAIN FRONT. THE NEXT SYSTEM WILL BEGIN TO MOVE INTO
MONTANA TUESDAY NIGHT AND SHOULD BRING AN INCREASE IN SHOWERS AND
THUNDERSTORMS TO THE AREA TUESDAY AFTERNOON AND EVENING. THIS
EVENT LOOKS LIKE IT SHOULD BRING MORE WIDESPREAD PRECIPITATION TO
THE AREA AS THE MOVES ACROSS THE STATE WEDNESDAY. PRECIPITATION IS
EXPECTED TO DECREASE WEDNESDAY AFTERNOON AND EVENING. TEMPERATURES
SHOULD COOL OFF TUESDAY AND WEDNESDAY BACK BELOW SEASONAL
AVERAGES. SUK
WEDNESDAY NIGHT THROUGH MONDAY. AT THIS TIME, FORECAST CONFIDENCE
IS LOW FOR MUCH OF THIS PERIOD AS PRIMARY FORECAST MODELS NOT
SHOWING MUCH CONSENSUS, ESPECIALLY ON PRECIPITATION COVERAGE AND
AMOUNTS. THE MODEL DIFFERENCES CENTER ON THE EVOLUTION OF A BROAD
SHORTWAVE TROF THAT WILL BE OFF THE CALIFORNIA COAST ON THURSDAY.
MODELS ARE IN GENERALLY GOOD AGREEMENT THAT THE TROF WILL MAKE
SLOW EASTWARD PROGRESS AND BE CENTERED OVER THE GREAT BASIN/DESERT
SOUTHWEST BY LATE FRIDAY. PLUMES OF MOISTURE STREAMING NORTHWARD
AHEAD OF THE TROF AXIS WILL BRING SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS INTO MT BY THURS AFTN CONTINUING THRU FRIDAY, WITH
THE ECMWF MODEL INDICATING MUCH WIDER PRECIP COVERAGE OVER
CENTRAL/SOUTHWEST MT. THINGS GET MORE COMPLICATED OVER THE WEEKEND
AS THE TROF LIFTS NORTHEASTWARD TOWARD THE CENTRAL ROCKIES. BOTH
THE GFS AND EC MODELS SHIFT OUR WINDS ALOFT TO EASTERLY AS THE
TROF PASSES TO OUR SOUTH, SETTING UP THE POSSIBILITY OF PULLING
EXTENSIVE GULF OF MEXICO MOISTURE THROUGH THE UPPER MIDWEST AND
INTO THE TREASURE STATE ON BOTH SAT/SUN. THE EC IS NOTABLY
STRONGER WITH THIS LONG MOISTURE FETCH, DRIVEN MAINLY BY A CLOSED
MID-LEVEL LOW PRESSURE AREA WITHIN THE TROF, WHEREAS THE GFS
INDICATES AN OVERALL WEAKER TROF WITH LESS MOISTURE OVER OUR
REGION. IN FACT, THE GFS HAS MUCH OF THE TROF AND PRECIPITATION
OUT OF OUR AREA BY SUNDAY MORNING WHILE THE EC PAINTS EXTENSIVE
RAINFALL WITH AMOUNTS RANGING FROM 0.1 INCH ALONG THE HI-LINE TO
0.5-0.75 INCH FROM GREAT FALLS SOUTHWARD TO THE IDAHO BORDER.
GIVEN THE TROUBLESOME MODEL DIFFERENCES, THE CURRENT EXTENDED
FORECAST LARGELY RELIES ON CLIMATOLOGICAL PRECIP PROBABILITIES
(MOSTLY 30-40%) FOR SATURDAY AND EARLY SUNDAY, THEN REDUCES RAINFALL
CHANCES SUN EVE INTO MONDAY AS THE TROF HEADS TOWARD THE GREAT LAKES
STATES. THE GOOD NEWS IS THAT IT LOOKS THAT MOST/ALL OF THE FORECAST
AREA SHOULD RECEIVE SOME NEEDED RAINFALL THIS WEEKEND; WE`LL JUST
HAVE TO WAIT FOR ADDITIONAL MODEL OUTPUT TO GET A BETTER ESTIMATE ON
AMOUNTS. AS FOR TEMPERATURES, THEY WILL REMAIN AT OR SLIGHTLY ABOVE
SEASONAL VALUES THROUGH THE LATTER HALF OF THE WEEK, WITH HIGHS IN
THE MID- AND UPPER 60S EACH DAY. WARANAUSKAS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 36 60 41 59 / 10 20 30 60
CTB 30 56 35 51 / 10 10 20 70
HLN 40 61 41 65 / 30 30 40 50
BZN 38 60 38 66 / 20 20 50 40
WEY 30 62 31 61 / 30 40 40 30
DLN 41 62 41 67 / 20 40 50 40
HVR 33 63 36 59 / 10 10 20 60
LWT 37 59 39 63 / 20 20 30 50
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
411 AM CDT TUE MAY 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT TUE MAY 12 2015
HIGH PRESSURE CENTERED ACROSS KS MOVES EAST INTO
MISSOURI TODAY. LOW PRESSURE WILL BEGIN TO ORGANIZE ACROSS THE NRN
HIGH PLAINS THIS AFTERNOON. THE MODEL CONSENSUS SHOWS STRONG RETURN
FLOW DEVELOPING THIS AFTERNOON WITH SOUTH WINDS INCREASING TO 20 TO
30 MPH ACROSS WRN NEB. THESE WINDS SHOULD CONTINUE TONIGHT AS THE
LOW LEVEL JET FORMS AND STRENGTHENS TO AROUND 50 KT.
THE TEMPERATURE FORECAST TODAY FOLLOWS THE WARMER SIDE OF THE MODEL
CONSENSUS. SEVERAL MODELS WERE VERY COLD WITH HIGHS IN THE 60S WHILE
THE RAP WAS VERY WARM WITH HIGHS IN THE UPPER 70S. THE FORECAST IS
FOR HIGHS IN THE UPPER 60S TO MID 70S.
LOWS TONIGHT FALL INTO THE UPPER 40S TO AROUND 50. SOUTH WINDS AT 15
TO 20 MPH SHOULD KEEPS LOWS MILD.
LASTLY...THE MODELS SHOW A WEAK DISTURBANCE FIRING THUNDERSTORMS ON
THE LARAMIE AND FRONT RANGES LATE THIS AFTERNOON AROUND 21Z WHICH
CARRY EAST TOWARD WESTERN NEBRASKA. THE BEST GUESS IS FOR ISOLATED
SPRINKLES THIS EVENING. THE GFS WAS THE WET MODEL WHICH ACTUALLY
SHOWS SOME MEASURABLE QPF.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM CDT TUE MAY 12 2015
MODELS CONTINUE TO ADVERTISE A RAPID RETURN OF GULF MOISTURE TAKING
PLACE WEDNESDAY...WITH MODELS PROJECTING 850 MB DEW POINTS IN THE
10 TO 12C RANGE BY WEDNESDAY EVENING ACROSS THE REGION.
A LARGE UPPER TROUGH WILL BE TAKING SHAPE ALONG THE WEST COAST MID
TO LATE WEEK...WITH A LEAD SHORTWAVE EJECTING NORTHEAST THROUGH THE
PLAINS AHEAD OF THE TROUGH WEDNESDAY NIGHT INTO THURSDAY. THIS
SYSTEM IS SHOWN TO HAVE SOMEWHAT OF A NEGATIVE TILT...WHICH WILL
HELP DRAW MOISTURE WESTWARD INTO THE HIGH PLAINS. THE COMBINATION OF
STRONG LIFT AND MOISTURE TRANSPORT ON A SOUTHERLY LOW LEVEL
JET...CONTINUES TO GIVE CONFIDENCE THAT PRECIPITATION SHOULD RESULT
LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. WILL MAINTAIN THE
LIKELY POPS ALONG AND EAST OF HIGHWAY 83 WEDNESDAY NIGHT...AND ALSO
INTRODUCE EVENING LIKELY POPS ALONG A SURFACE TROUGH ACROSS THE
PANHANDLE INTO THE WESTERN SANDHILLS.
THE LEAD WAVE QUICKLY PASSES AND MOVES NORTHEAST AWAY FROM THE AREA
THURSDAY. ATTENTION THEN TURNS TO THE LONG WAVE TROUGH ALONG THE
WEST COAST. MODELS/ENSEMBLES PROJECT THIS TO MOVE EAST AS A CLOSED
SYSTEM DURING THE WEEKEND. THE GENERAL CONSENSUS IN THE MODELS AND
ENSEMBLE MEAN IS FOR THE CENTER OF THE SYSTEM TO TRACK ACROSS
WYOMING INTO SOUTH DAKOTA. THIS PUTS OUR AREA IN THE WARM MOIST
SECTOR. INSTABILITY LOOKS TO BE STRONG...AND AS DEEP LAYER SHEAR
INCREASES...STRONG TO SEVERE STORMS WILL LIKELY RESULT. WILL
INTRODUCE THE POTENTIAL FOR SEVERE THUNDERSTORMS IN THE HAZARDOUS
WEATHER OUTLOOK FOR FRIDAY AND SATURDAY. THE GFS AND ECMWF CONTINUE
TO DIFFER SOMEWHAT ON THE LOW LEVEL BOUNDARY PLACEMENT...BUT THE
LATEST TREND IS TO HOLD THE DRY LINE BACK TO THE WEST ACROSS WESTERN
NEBRASKA INTO WESTERN KANSAS...WHICH WOULD PLACE SEVERE STORM
DEVELOPMENT ACROSS THE FORECAST AREA OF WESTERN AND NORTH CENTRAL
NEBRASKA. WE WILL LIKELY BE IN THE MIDST OF THE MID LEVEL DRY SLOT
SUNDAY AS THE STORM SYSTEM CROSSES THE DAKOTAS...BUT AT LEAST SOME
CHANCE FOR SHOWERS IN WRAP AROUND PATTERN ACROSS NORTHERN NEBRASKA.
DRY WEATHER FOR MONDAY...THEN MORE CHANCES FOR RAIN NEXT WEEK BEYOND
THE FORECAST PERIOD...AS THE NEXT DEEP TROUGH MOVES EAST INTO THE
WESTERN CONUS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1120 PM CDT MON MAY 11 2015
EXCEPT FOR A BRIEF PERIOD OF MIDDLE CLOUD CEILINGS 10-14Z...
UNLIMITED CEILING AND VISIBILITY ARE FORECAST TO CONTINUE
TONIGHT AND TUESDAY THROUGH LATE TUESDAY EVENING.
VARIABLE WIND IS EXPECTED TONIGHT AS HIGH PRESSURE DRIFTS TO THE
EAST AND WIND SWINGS AROUND TO THE SOUTH. WIND WILL INCREASE TUESDAY
MORNING AND...BY 15Z...IS EXPECTED TO BE 150-180 AT 12-15G20-24. THE
WIND IS THEN EXPECTED TO CONTINUE INCREASING...BECOMING 160-180 AT
18-22G28-32KT. AFTER 00Z...THE WIND WILL DECREASE TO 12-14G20-22KT.
&&
.HYDROLOGY...
ISSUED AT 359 AM CDT TUE MAY 12 2015
THE COMBINATION OF SEASONAL SNOW MELT IN THE UPPER SOUTH PLATTE
RIVER BASIN AND RECENT HEAVY PRECIPITATION OVER WESTERN NEBRASKA AND
NORTHEAST COLORADO WILL LEAD TO FLOODING ON THE SOUTH PLATTE AND
PLATTE RIVERS IN SOUTHWEST NEBRASKA LATER THIS WEEK AND INTO EARLY
NEXT WEEK. AT THIS TIME SOME UNCERTAINTY STILL REMAINS WITH THE
FORECAST AS KEY UPSTREAM GAUGES IN NORTHEAST COLORADO HAVE YET TO
CREST. HOWEVER...LATEST PROJECTIONS CONTINUE TO HIGHLIGHT AN
INCREASING THREAT FOR SIGNIFICANT FLOODING TO OCCUR...POTENTIALLY
NEAR SEPTEMBER 2013 FLOOD LEVELS.
RIVER STAGE FORECASTS WILL BE CLOSELY MONITORED AND UPDATED ONCE
MORE UPSTREAM RIVER DATA BECOMES AVAILABLE. PERSONS THAT LIVE IN
VULNERABLE AREAS ALONG THE SOUTH PLATTE RIVER AND PLATTE RIVER IN
SOUTHWEST NEBRASKA SHOULD PAY CLOSE ATTENTION TO FLOOD FORECASTS IN
THE COMING DAYS AND BE PREPARED TO TAKE PROPER ACTION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR
NEZ006>010-026>029-038-058-059-069>071.
FREEZE WARNING UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR NEZ004-
005-022>025-035>037-056-057-094.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...SPRINGER
HYDROLOGY...MARTIN/TAYLOR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1242 AM CDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 1242 AM CDT TUE MAY 12 2015
TEMPS ARE FALLING SLOWLY AS WINDS ARE STILL 5-7 KTS MOST
LOCATIONS. 04Z HRRR INDICATES THE SFC RIDGE AXIS WILL MOVE THRU
RIGHT AROUND DAWN. WINDS SHOULD THEN DROP OFF AND ALLOW TEMPS TO
REACH THE LOW-MID 30S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 1242 AM CDT TUE MAY 12 2015
THIS SERVES AS THE FIRST DRAFT FOR THIS SHIFT...
ALOFT: HEIGHTS WILL CONT TO RISE TODAY. WNW FLOW WILL TRANSITION
TO WSW TONIGHT AS A SHORTWAVE RIDGE PASSES THRU.
SURFACE: HIGH PRES WAS OVER KS AT 08Z AND WILL DRIFT E OF THE
REGION TODAY. MEANWHILE...LOW PRES WILL CONT ORGANIZING OVER THE
INTERMOUNTAIN W THRU TONIGHT. RETURN FLOW WILL RESULT WITH A
TIGHTENING PRES GRAD.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 339 PM CDT MON MAY 11 2015
A LARGE AREA OF LOW PRESSURE WILL DROP SOUTH ACROSS THE WESTERN
STATES OVER THE MIDDLE OF THE WEEK...RESULTING IN GENERALLY
SOUTHWESTERLY FLOW ALOFT AND MULTIPLE CHANCES FOR THUNDERSTORMS
BEGINNING WEDNESDAY AFTERNOON. TEMPERATURE WISE...GENERALLY MILD
CONDITIONS ARE EXPECTED THROUGH THE EXTENDED PERIODS...WITH
TEMPERATURES EXPECTED TO BE NEAR OR ABOVE CLIMATOLOGY EACH DAY.
STARTING WEDNESDAY...EXPECT A WEAK UPPER LEVEL DISTURBANCE/OPEN
WAVE TO BE LIFTED NORTHWARD ACROSS THE PLAINS AS A LARGE AREA OF
LOW PRESSURE CIRCULATES ACROSS THE WESTERN STATES. WHILE SOUTHERLY
RETURN FLOW WILL HELP DEWPOINTS CLIMB BACK TO NEAR 50 BY WEDNESDAY
AFTERNOON...INSTABILITY WILL STILL BE VERY MARGINAL...SO OPTED TO
ONLY MENTION AN ISOLATED THUNDERSTORM WEDNESDAY/WEDNESDAY
NIGHT...WITH THE FOCUS OF THIS ACTIVITY SHIFTING SLIGHTLY EASTWARD
FROM PREVIOUS FORECASTS AS THE LLJ IS FORECAST TO BE FOCUSED JUST
EAST OF THE LOCAL AREA.
WHILE INSTABILITY VALUES WILL BE A LITTLE MORE RESPECTABLE ON
THURSDAY AFTERNOON...THE LACK OF ANY SIGNIFICANT FORCING MECHANISM
SHOULD HELP LIMIT ANY DEVELOPMENT TO PRIMARILY THE DAYTIME
HOURS... DEPENDING ON THE TIMING OF THE AFOREMENTIONED
DISTURBANCE...WITH DRY WEATHER ANTICIPATED THURSDAY NIGHT INTO
FRIDAY MORNING.
THEREAFTER...INSTABILITY WILL INCREASE SIGNIFICANTLY ACROSS THE
LOCAL AREA WITH MULTIPLE DISTURBANCES PASSING OUT OF THE LONGWAVE
TROUGH. THIS SHOULD RESULT IN MORE WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY ACROSS THE LOCAL AREA FOR THE END OF THE
WEEK AND START OF THE UPCOMING WEEKEND. IN ADDITION...WITH A
MODEST LLJ EXPECTED TO DEVELOP EACH NIGHT...INCREASING SHEAR
VALUES...AND MULTIPLE PASSING UPPER LEVEL DISTURBANCES...EXPECT
THE POTENTIAL FOR SOME SEVERE WEATHER TO RETURN ON FRIDAY AND
SATURDAY...WITH THE LOCAL AREA NOW HIGHLIGHTED FOR A CHANCE OF
SEVERE WEATHER BY SPC IN THEIR DAY 5 AND DAY 6 FORECASTS.
COULD SEE A BREAK IN SHOWER AND THUNDERSTORM ACTIVITY LATE IN THE
UPCOMING WEEKEND AND EARLY NEXT WEEK AS A SHORTWAVE TROUGH
TRANSITIONS ACROSS THE PLAINS...BUT MODELS ARE HINTING AT YET
ANOTHER UPPER LEVEL LOW EMERGING FROM THE SOUTHWEST EARLY NEXT
WEEK WHICH COULD AFFECT THE LOCAL AREA JUST BEYOND THE CURRENT
SCOPE OF THE EXTENDED FORECAST.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUE NIGHT)
ISSUED AT 1242 AM CDT TUE MAY 12 2015
REST OF TONIGHT: VFR SKC. LIGHT W WINDS WILL BECOME LGT AND VRBL.
CONFIDENCE: HIGH
TUE: VFR WITH A PERIOD OF PATCHY OF 7K FT SCT CLOUDS. WINDS BECOME
S AND WILL GUST 20-27 KTS WITH POTENTIAL FOR 32 KTS. CONFIDENCE:
HIGH
TUE EVE: VFR. S WINDS BECOME SSE AND WILL CONT TO GUST UP TO 25
KTS AT TIMES. HAVE INCLUDED LLWS TO COVER PERIODIC LULLS IN SFC
WINDS. CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR NEZ039-040-046-
047-060>062-072>075-082>085.
KS...FROST ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ005>007-
017>019.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...ROSSI
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS NORMAN OK
325 AM CDT TUE MAY 12 2015
.DISCUSSION...
EAST TO SOUTHEAST WINDS WILL DEVELOP TODAY AS SURFACE HIGH
PRESSURE OVER KANSAS BUILDS EAST. MEANWHILE...CONVECTION ALONG
THE EAST TEXAS COAST WILL DELAY THE RETURN OF DEEP MOISTURE
NORTHWARD. SCATTERED SHOWERS AND A FEW STORMS HAVE FORMED WITHIN
AN AREA OF MID-LEVEL MOISTURE RETURN OVER CENTRAL AND WEST TEXAS.
THE HRRR SORTA HAS A HANDLE ON THIS AND GRADUALLY WEAKENS IT
DURING THE MORNING...WHILE THE NAM12 IS MORE AGGRESSIVE IN
DEVELOPING CONVECTION IN WESTERN NORTH TEXAS. FOR NOW WILL KEEP
IN CHANCE POPS FOR OUR TEXAS COUNTIES.
ANOTHER HEAVY RAIN EVENT SEEMS LIKELY LATE TUESDAY NIGHT INTO
WEDNESDAY. MODELS ARE SIMILAR IN TRACKING A PROGRESSIVE TROUGH
ACROSS THE SOUTHWESTERN STATES TONIGHT AND THEN OVER WEST TEXAS
AND OKLAHOMA WEDNESDAY INTO EARLY THURSDAY. DEEP MOISTURE IN PLACE
OVER SOUTH TEXAS WILL BE TRANSPORTED NORTHWARD TONIGHT INTO
WEDNESDAY IN ADVANCE OF THE TROUGH. THE BEST COMBINATION OF UPPER
AND LOW LEVEL JET FEATURES...SHOULD FOCUS THE HEAVIEST RAIN OVER
WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA EARLY WEDNESDAY...WITH
A GRADUALLY SHIFT NORTH AND EAST DURING THE AFTERNOON AND NIGHT.
WIDESPREAD 2 INCH RAIN AMOUNTS ARE LIKELY WITH 3 TO 4 INCH TOTALS
POSSIBLE. WITH RECENT HEAVY RAIN OVER THE SOUTHERN HALF OF
OKLAHOMA AND NORTH TEXAS...FLOODING WILL AGAIN BE A CONCERN.
BRIEF SHORTWAVE RIDGING ON THURSDAY WILL KEEP RAIN CHANCES
LOW...BUT ANOTHER TROUGH WILL BEGIN TO SHIFT EASTWARD FRIDAY INTO
THE WEEKEND. BETTER INSTABILITY IS EXPECTED TO DEVELOP AHEAD OF
THIS SYSTEM WHICH WILL RESULT IN AN INCREASE IN SEVERE WEATHER
CHANCES FRIDAY INTO SATURDAY. ANOTHER FRONT IS EXPECTED TO PUSH
ACROSS THE SOUTHERN PLAINS SUNDAY INTO MONDAY WHICH WILL BRING
ANOTHER PERIOD OF DRY WEATHER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 71 56 67 62 / 0 30 80 80
HOBART OK 71 56 67 61 / 0 40 90 70
WICHITA FALLS TX 72 59 70 64 / 10 60 90 70
GAGE OK 71 53 66 56 / 0 20 70 60
PONCA CITY OK 72 53 66 59 / 0 10 70 90
DURANT OK 73 59 71 64 / 10 40 80 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
OKZ007-008-012-013-017>020-022>048-050>052.
TX...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND
915 PM PDT MON MAY 11 2015
.SYNOPSIS...AN UPPER LOW WILL MOVE INLAND AND ACROSS SOUTHWESTERN
OREGON TONIGHT AND TUESDAY. A BAND OF STRATIFORM RAIN ALONG
THE COLUMBIA RIVER WILL PINWHEEL SOUTH ALONG THE COAST AND RETURN
INLAND ACROSS THE CENTRAL AND SOUTHERN OREGON COAST TUESDAY. THE
UPPER LOW WILL GRADUALLY FILL AS IT DRIFTS NORTHEAST TOWARD EASTERN
WASHINGTON TUESDAY NIGHT AND WEDNESDAY WITH LIGHT SHOWER ACTIVITY
CONTINUING. AT THE SAME TIME...ANOTHER LOW DROPS SOUTH OFF THE
PACIFIC NORTHWEST COAST AND SLOWLY MOVES INTO CALIFORNIA DURING THE
LATTER PART OF THE WEEK AND NEXT WEEKEND.
&&
.UPDATE...UPPER LOW CENTER ROUGHLY OVER THE SOUTHERN OREGON COAST
NEAR PORT ORFORD. THE BULK OF CONVECTION EAST OF THE CASCADES HAS
ENDED WITH A COUPLE STRAY CELLS FIRING AT THIS HOUR. 21Z SREF AND
00Z NAM/GFS RUNS ARE KEEPING THE UPPER LOW CENTER JUST THIS SIDE OF
THE OR/CA BORDER FOR TONIGHT WHICH IS CLOSER TO WHAT PREVIOUS RUNS
OF THE NAM HAD SHOWN. ADDITIONALLY...THE BETTER DYNAMIC LIFT
ASSOCIATED WITH THE DIFFLUENT SE QUADRANT OF THE LOW DEVELOPED ABOUT
75 MILES FURTHER EAST THAN WAS PREVIOUSLY EXPECTED. THUS...A BLEND
OF THE 00Z NAM...AND TO A LESSER EXTENT...THE 12Z ECMWF SEEMS TO BE
A DECENT MIDDLE GROUND WITH REGARD TO HANDLING THE REST OF TONIGHT.
AS SUCH...AM FEELING THE PRIMARY DEFORMATION BAND WILL STAY ALONG
THE COLUMBIA RIVER WITH THE EASTERLY FLOW ALONG THE NORTHERN
PERIPHERY OF THE UPPER CIRCULATION CONTINUING TO STREAM
PRECIPITATION OUT TO SEA ACROSS ASTORIA. OVERNIGHT WILL SEE THE FLOW
AND DEEPER MOISTURE THEN WRAP BACK SOUTH CLOSER TO THE COAST.
THIS STANDS TO LEAVE THE CASCADE WEST SLOPES (NOW IN THE LEE OF THE
SYSTEM) ON THE RELATIVELY DRIER SIDE OF THINGS. THE LEADING EDGE OF
THE WRAP AROUND MOISTURE THEN CURLS BACK INLAND AROUND
NEWPORT/FLORENCE AND PICKS UP A BIT OF UPSLOPE ENHANCEMENT FOR THE
MORNING HOURS TOMORROW. DID NOT HAVE ENOUGH CONFIDENCE THEREAFTER TO
MAKE CHANGES TO THE FORECAST PACKAGE AS WE WILL NEED TO SEE HOW THIS
FIRST PART WORKS OUT. IT SHOULD BE SAID THAT NO ONE MODEL IS REALLY
DOING A STELLAR JOB OF FINDING THE CORRECT MIX OF RAIN PLACEMENT
WITH RAIN INTENSITY LEAVING THIS FORECAST WITH MODERATE CONFIDENCE
AT BEST.
UPDATES WILL BE AVAILABLE SHORTLY. /JBONK
&&
.AVIATION...RAIN AND OCCASIONAL MVFR CIG/VIS ARE SPREADING WEST
AND SOUTH THIS EVENING WITH THE TREND CONTINUING INTO THE LATE
EVENING. EXPECT MORE WIDESPREAD MVFR CONDITIONS TO DEVELOP
THROUGH THE OVERNIGHT AND STICK AROUND MUCH OF TUESDAY WITH RAIN.
WINDS WILL BE VARIABLE THROUGH THE PERIOD AND GENERALLY REMAIN
BELOW 10 KT.
KPDX AND APPROACHES...MVFR CIGS DEVELOPING BY 12Z TUESDAY AND
STAYING THROUGH TUESDAY. OCCASIONAL MVFR VIS WITH RAIN. BOWEN
&&
.MARINE...HIGH PRESSURE OVER THE NE PACIFIC IS KEEPING CONDITIONS
FAIRLY BENIGN. SEAS SHOULD REMAIN AROUND 5 TO 7 FT THROUGH
TUESDAY WITH NORTHWESTERLY WINDS STAYING BELOW 20 KT. SEAS WILL BE
CHOPPY DUE TO SHORT PERIODS AROUND 8 SECONDS. MADE ONLY MINOR
TWEAKS TO THE FORECAST FOR THE EVENING UPDATE. BOWEN
A WEAK LOW PRESSURE SYSTEM MOVES THROUGH ON WEDNESDAY...BUILDING
SEAS TO AROUND 8 FT...BUT WINDS EXPECTED TO REMAIN BELOW 20 KT.
SEAS FALL BACK DOWN TO 5 TO 6 FT BY THE END OF THIS WEEK WITH THE
RETURN OF NORTHWESTERLY WINDS AS HIGH PRESSURE BUILDS BACK OVER
THE WATERS. -MCCOY
&&
.PREV DISCUSSION... /ISSUED 215 PM PDT MON MAY 11 2015/
SHORT TERM...TONIGHT THROUGH THURSDAY...EARLY-AFTERNOON WATER VAPOR
LOOP SHOWS AN UPPER LEVEL LOW CENTERED WEST OF KONP AND SINKING TO
THE S. CONSIDERABLE MOISTURE IN WATER VAPOR FOCUSED OVER THE
CASCADES. ALSO LOOKS LIKE A SHORT-WAVE ROTATING INTO SOUTH-CENTRAL
OREGON...WHICH HAS RESULTED IN THUNDERSTORM ACTIVITY IN SWRN LAKE
COUNTY. KRTX DUAL-POL DOPPLER RADAR SHOWS THE BULK OF THE PRECIP
ECHOES ALONG THE CENTRAL AND NORTH OREGON CASCADES INTO ERN CLARK AND
COWLITZ COUNTIES IN SW WA. 12Z MODEL RUNS AGREE THAT THE UPPER LOW
WILL CONTINUE TO DRIFT SOUTH THIS EVENING...THEN MOVE INLAND OVER NW
CALIFORNIA BY 12Z TUE. MODELS ALSO SUGGEST THAT PRECIP WILL BECOME
MORE ENHANCED LATE THIS AFTERNOON DUE TO SE-S MID-LEVEL FLOW.
HOWEVER...MODELS DO NOT SEEM TO AGREE ON QPF. GFS SHOW MUCH MORE
RAINFALL TONIGHT THAN THE NAM OR ECMWF. THE NAM PIVOTS THE DEVELOPING
DEFORMATION BAND FURTHER N THAN THE GLOBAL MODELS. THE 19Z HRRR RUN
HAS THE DEFORMATION BAND DEVELOPING A FEW HOURS LATER THAN THE
EARLIER MORNING RUNS INDICATED...AND SETTLING OVER SRN WA DOWN TO
ABOUT A KTMK-KSLE-MT. HOOD LINE BY 07Z TUE. HIGH CONFIDENCE IN
WETTING RAIN AMOUNTS...ONE-QUARTER INCH OR GREATER...ACROSS PORTIONS
OF THE CWA TONIGHT AND TUE MORNING. LOWER CONFIDENCE ON EXACT
LOCATION OF THE DEFORMATION BAND.
CONVECTIVE CHANCES TODAY DO NOT LOOK ALL THAT IMPRESSIVE. NAM
SOUNDINGS FOR KPDX SHOW AN ISOTHERMAL LAYER THIS AFTERNOON BETWEEN 850
AND 700 MB. MODEL SOUNDING FOR A POINT IN THE CASCADES HAS THE SAME
GENERAL PROFILE...BUT DOES HAVE AN LI NEAR 0C THIS AFTERNOON.
INCREASED POPS IN THE 00-06Z TUE TIME FRAME...ESPECIALLY IN THE
CASCADES AND NORTHERN ZONES. THE DEFORMATION ZONE PERSISTS TUE
MORNING. THE NAM ROTATES IT ACROSS SW WA TO THE N OREGON COAST BY 18Z
TUE...SIMILAR TO THE ECMWF. IT FINALLY BREAKS UP TUE AFTERNOON. THE
MODELS SHOW A DECENT AMOUNT OF CYCLONIC LOW LEVEL ONSHORE FLOW
DEVELOPING BELOW THIS BAND AS WELL. CASCADE MODEL SOUNDINGS SUGGEST A
LIT MORE SUPPORT FOR CONVECTION TUE AFTERNOON. NAM SOUNDING GIVES
200-250 J/KG CAPE 00Z WED...WHILE THE GFS HAS NEAR-ZERO LI VALUES.
THE REMAINS OF THE UPPER LOW LIFT OUT INTO SE WASHINGTON TUE NIGHT
AND INTO NE WA BY WED AFTERNOON. ANY REMAINING DEFORMATION WILL
LINGER OVER THE S WA CASCADES WED MORNING AND HAVE THE HIGHEST POPS
THERE. DECIDED TO INCLUDE A MENTION OF THUNDERSTORMS FOR THE CENTRAL
AND N OREGON CASCADES BEGINNING WED AFTERNOON. MODEL SOUNDINGS SHOW A
DEFINITE CAP AROUND 700 MB WED MORNING...BUT BY 21Z THE CAP IS GONE
WITH CAPE OVER 100 J/KG. AT 00Z THU MODEL CAPE HAS INCREASED TO
NEARLY 300 J/KG WITH LI -1C. THINK THE S WA CASCADES WILL HAVE TOO
MUCH CLOUD COVER AS THE DEFORMATION BAND SLOWLY DRIFTS N. MUCH MORE
IMPRESSIVE CONVECTIVE ENVIRONMENT POSSIBLE THU. PRIMARY UPPER LOW
SETTLES OFF THE N CALIFORNIA COAST THU AFTERNOON...WHICH SETS UP
UNSTABLE SE-S FLOW OVER THE FORECAST AREA. NAM SOUNDING NEAR SANTIAM
PASS HAS NEARLY 550 J/KG CAPE WITH AN LI OF -2C 00Z FRI. GFS EVEN
MORE IMPRESSIVE WITH CONVECTIVE PARAMETERS THU. WEISHAAR
LONG TERM...THURSDAY NIGHT THROUGH SUNDAY...BY THURSDAY NIGHT A
BROAD UPPER LOW PRESSURE WILL CONTINUE A GENERAL TRACK SOUTHWARD
ALONG THE CALIFORNIA COAST. MODEL GUIDANCE THIS AFTERNOON IS COMING
INTO GOOD AGREEMENT WITH THE GENERAL PATTERN AND EXPECT SHOWERS
LINGERING THURSDAY NIGHT AND ALSO ON FRIDAY...WITH THE BEST CHANCES
TOWARDS THE CASCADES. MIGHT ALSO BE ENOUGH INSTABILITY TO GET A FEW
THUNDERSTORMS NEAR THE CASCADES FROM MT HOOD SOUTHWARD ON FRIDAY.
THIS UPPER LOW CONTINUES EASTWARD WITH THE NEXT UPPER LOW PRESSURE
SYSTEM MOVING TOWARDS THE REGION OVER THE WEEKEND...MAINTAINING
ONSHORE FLOW ALOFT AND THE POTENTIAL FOR CONTINUING SHOWERS THIS
WEEKEND. OVERALL...NOT MUCH CHANGE TO THE OVERALL PATTERN THROUGH
THE EXTENDED PERIOD WITH TEMPERATURES NEAR SEASONAL NORMS AND SHOWER
CHANCES CONTINUING. CULLEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
346 AM EDT TUE MAY 12 2015
.SYNOPSIS...
SUMMERTIME WARMTH AND HUMIDITY WILL COME TO AN END TODAY AS A
VIGOROUS UPPER TROF AND ASSOCIATED COLD FRONT CROSSES THE REGION.
COOLER...DRIER AND WINDY CONDITIONS WILL ARRIVE DURING THE
DAYLIGHT HOURS TUESDAY...AND LAST THROUGH WEDNESDAY NIGHT. MILDER
CONDITIONS WILL RETURN FOR THURSDAY AND FRIDAY AND CONTINUE THIS
WEEKEND AS ANOTHER UPPER RIDGE BUILDS ACROSS THE REGION.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
SFC-850 MB NORTH/SOUTH THETA-E RIDGE WAS SLICING RIGHT THROUGH
CENTRAL PENN AT 07Z WITH JUST SOME ISOLATED-SCATTERED SHOWERS
RACING QUCIKLY TO THE ENE.
SFC DEWPOINTS DROPPING OFF BY SEVERAL DEG F ALONG THE PENN/OHIO
BORDER ATTM /MARKING THE WEAK...INITIAL COLD FRONT THAT WILL SLIDE
ACROSS MUCH OF THE FCST AREA BY 12Z.
TEMPS WILL STAY MILD FOR THE REST OF THE NIGHT AND IT WILL FEEL
MUGGY WITH TEMPS AND DEWPOINTS IN THE L-M 60S /EXCEPT U50S INVOF
KBFD/.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
INITIAL CFRONT CLEARS OUR FAR EASTERN COUNTIES DURING THE MID
MORNING HOURS TODAY...FOLLOWED BY WINDY AND DRIER CONDITIONS IN
STORE FOR MOST OF THE REGION. MODEL FORECAST SOUNDINGS INDICATE
MODERATE MIXING POTENTIAL WITH MANY AREAS SEEING 30-35 MPH GUSTS
OR HIGHER. EXPECT HIGHER TERRAIN OF THE NORTH AND WEST TO SEE SCT
-SHRA...WHILE CENTRAL AND SOUTHEAST AREAS REMAIN PARTLY SUNNY AND
DRY.
HIGHS WILL RANGE FROM JUST 60 TO 65F ACROSS THE NORTHWEST MTNS...TO
THE LOWER 80S THROUGHOUT THE LOWER SUSQ RIVER VALLEY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STILL LOOKING AT A FEW SHOWERS ACROSS THE NORTH TUESDAY NIGHT
INTO WED...WITH THE COLD AIR ALOFT.
IT WILL BE BREEZY AND COLDER FROM LATE TUE INTO THU MORNING.
LATER SHIFTS WILL NEED TO MONITOR THE NEED FOR FROST AND
FREEZE PRODUCTS.
MID SHIFT INSERTED SHOWERS INTO THE FCST FOR FRIDAY INTO SAT.
THIS BASED ON WEAK SYSTEM DROPPING SE. WHILE MOISTURE MAY BE
LIMITED...DIRECTIONAL SHEAR WILL BE THERE. I DID CUT BACK
ON THE SHOWERS SOME ON THE FIRST PART OF FRIDAY.
DID ADJUST POPS SOME FOR SUNDAY...AS SYSTEM DROPS SE OF OUR
AREA...DID CUT BACK SOME.
FOR MONDAY...ADJUSTED POPS SOME MORE...AS WE WILL BE ON THE
EASTERN AND NORTHERN EDGE OF THE WARM ADVECTION.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
RADAR AT 06Z SHOWS ONE LINE OF SHRA/TSRA PUSHING THRU EASTERN PA
AND ANOTHER BATCH OF SHRA ASSOC WITH APPROACHING COLD FRONT OVER
WESTERN PA. FOR MUCH OF CENTRAL PA...NO SIG CIG/VIS REDUCTIONS
ARE EXPECTED EARLY THIS MORNING. THE EXCEPTION COULD BE KBFD AND
KJST...WHERE A BRIEF PERIOD OF IFR CIGS MAY DEVELOP AS PLUME OF
MOIST AIR ALONG COLD FRONT ASCENDS THE W MTNS. MDL RH TIMESECTIONS
AND HRRR OUTPUT SUGGEST THE WINDOW OF OPPORTUNITY FOR IFR CONDS AT
KBFD/KJST WILL BE 09Z-11Z. AFTER 11Z...DRIER AIR WILL ARRIVE ON
WEST WIND...CAUSING IMPROVING CONDS.
WIDESPREAD VFR CONDS EXPECTED AFTER SUNRISE...AS DRIER AIR FLOWS
IN BEHIND COLD FRONT. MAIN CONCERN TODAY WILL BE THE GUSTY WEST
WINDS...RESULTING FROM TIGHT PRESSURE GRADIENT SOUTH OF LOW PRES
OVR S QUEBEC. MDL SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS BY THIS
AFTN. THE STRONGEST GUSTS WILL DIMINISH AFTER SUNSET...BUT IT
WILL REMAIN BREEZY OVERNIGHT.
OUTLOOK...
WED...NO SIG WX EXPECTED.
THU...EARLY AM FOG POSS NW MTNS.
FRI...PM SHRA/CIG REDUCTIONS POSS...MAINLY NW MTNS.
SAT...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
237 AM EDT TUE MAY 12 2015
.SYNOPSIS...
SUMMERTIME WARMTH AND HUMIDITY WILL COME TO AN END LATE TONIGHT
AND TUESDAY AS A VIGOROUS UPPER TROF AND ASSOCIATED COLD FRONT
CROSSES THE REGION. COOLER...DRIER AND WINDY CONDITIONS WILL
ARRIVE DURING THE DAYLIGHT HOURS TUESDAY...AND LAST THROUGH
WEDNESDAY NIGHT. MILDER CONDITIONS WILL RETURN FOR THURSDAY AND
FRIDAY AND CONTINUE THIS WEEKEND AS ANOTHER UPPER RIDGE BUILDS
ACROSS THE REGION.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
COLD POOL FROM THE STORMS OVER OH AND WRN PA HAVE MADE QUITE AN
ACTIVE EVENING AS IT FORMED INTO A NICE BOW ECHO. MANY DAMAGE
REPORTS WITH TREES NOW PRETTY MUCH LEAFED OUT EVERYWHERE. MESO
MDLS CONTINUE TO MAKE NO PRECIP TO THE SE OF AOO/UNV/IPT
OVERNIGHT. BUT ALLOWING FOR SOME CONTINUATION IN THE LINE OF
SHOWERS AS IT IS...BUT BUYING INTO THE WEAKENING/DISSIPATION A
LITTLE MORE AS THE LATEST ECHOES PLAY THAT THE GUST FRONT IS
RACING TOO FAR AHEAD OF THE SRN CELLS. THIS BODES WELL FOR
WEAKENING THERE. LEFT IN JUST A 30 POP FOR AN HR OR TWO FOR THE
SERN COS. COLD AIR SEEMS LIKE IT COMES IN TWO WAVES...WITH THE
FIRST SURGE LATER TONIGHT BEING ACCOMPANIED BY MORE
SHOWERS...MAINLY ACROSS THE NW MTNS. A SECONDARY FRONT IN THE
MORNING WILL ALSO MAKE A FEW SHRA.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
FRONT CLEARS SOUTHEASTERN COUNTIES EARLY TUESDAY...WITH WINDY AND
DRIER CONDITIONS IN STORE FOR MOST OF THE REGION. MODEL FORECAST
SOUNDINGS INDICATE MODERATE MIXING POTENTIAL WITH MANY AREAS
SEEING 30-35 MPH GUSTS OR HIGHER. EXPECT HIGHER TERRAIN OF THE
NORTH AND WEST TO SEE SCT -SHRA...WHILE CENTRAL AND SOUTHEAST
AREAS REMAIN PARTLY SUNNY AND DRY.
HIGHS WILL RANGE FROM THE UPPER 60S NORTHWEST TO THE LOWER 80S
LOWER SUSQ RIVER VALLEY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
STILL LOOKING AT A FEW SHOWERS ACROSS THE NORTH TUESDAY NIGHT
INTO WED...WITH THE COLD AIR ALOFT.
IT WILL BE BREEZY AND COLDER FROM LATE TUE INTO THU MORNING.
LATER SHIFTS WILL NEED TO MONITOR THE NEED FOR FROST AND
FREEZE PRODUCTS.
MID SHIFT INSERTED SHOWERS INTO THE FCST FOR FRIDAY INTO SAT.
THIS BASED ON WEAK SYSTEM DROPPING SE. WHILE MOISTURE MAY BE
LIMITED...DIRECTIONAL SHEAR WILL BE THERE. I DID CUT BACK
ON THE SHOWERS SOME ON THE FIRST PART OF FRIDAY.
DID ADJUST POPS SOME FOR SUNDAY...AS SYSTEM DROPS SE OF OUR
AREA...DID CUT BACK SOME.
FOR MONDAY...ADJUSTED POPS SOME MORE...AS WE WILL BE ON THE
EASTERN AND NORTHERN EDGE OF THE WARM ADVECTION.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
RADAR AT 06Z SHOWS ONE LINE OF SHRA/TSRA PUSHING THRU EASTERN PA
AND ANOTHER BATCH OF SHRA ASSOC WITH APPROACHING COLD FRONT OVER
WESTERN PA. FOR MUCH OF CENTRAL PA...NO SIG CIG/VIS REDUCTIONS
ARE EXPECTED EARLY THIS MORNING. THE EXCEPTION COULD BE KBFD AND
KJST...WHERE A BRIEF PERIOD OF IFR CIGS MAY DEVELOP AS PLUME OF
MOIST AIR ALONG COLD FRONT ASCENDS THE W MTNS. MDL RH TIMESECTIONS
AND HRRR OUTPUT SUGGEST THE WINDOW OF OPPORTUNITY FOR IFR CONDS AT
KBFD/KJST WILL BE 09Z-11Z. AFTER 11Z...DRIER AIR WILL ARRIVE ON
WEST WIND...CAUSING IMPROVING CONDS.
WIDESPREAD VFR CONDS EXPECTED AFTER SUNRISE...AS DRIER AIR FLOWS
IN BEHIND COLD FRONT. MAIN CONCERN TODAY WILL BE THE GUSTY WEST
WINDS...RESULTING FROM TIGHT PRESSURE GRADIENT SOUTH OF LOW PRES
OVR S QUEBEC. MDL SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS BY THIS
AFTN. THE STRONGEST GUSTS WILL DIMINISH AFTER SUNSET...BUT IT
WILL REMAIN BREEZY OVERNIGHT.
OUTLOOK...
WED...NO SIG WX EXPECTED.
THU...EARLY AM FOG POSS NW MTNS.
FRI...PM SHRA/CIG REDUCTIONS POSS...MAINLY NW MTNS.
SAT...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1258 AM CDT TUE MAY 12 2015
.DISCUSSION...UPDATED FOR 06Z AVIATION.
&&
.AVIATION...CONVECTION IS THE MAIN AVIATION CONCERN IN THE SHORT
TERM. LINE OF SHOWERS AND STORMS CONTINUES TO MOVE W TO E ACROSS
SOUTH TEXAS. KEPT SHRA/TSRA REMARKS IN THE TAFS FOR THE NEXT
SEVERAL HOURS. LOCALLY REDUCED VSBYS AND ERRATIC WINDS WILL OCCUR
IF THUNDERSTORMS DIRECTLY IMPACT TAFS. LAST COUPLE OF HRRR RUNS
INDICATE THERE COULD BE A LULL IN ACTIVITY LATER THIS MORNING AS
THIS ROUND OF STORMS MOVES OFF TO THE EAST. HOWEVER...ADDITIONAL
ACTIVITY WILL BE POSSIBLE AGAIN TODAY AS MOIST AIRMASS AND
BOUNDARY REMAINS IN THE AREA. IFR/MVFR CEILINGS TONIGHT SHOULD
TRANSITION TO MOSTLY MVFR/LOW END VFR DURING THE DAY ON TUESDAY.
OUTSIDE OF THUNDERSTORMS...WINDS WILL GENERALLY BE OUT OF THE EAST
AND ESE.
&&
.PREV DISCUSSION... /ISSUED 924 PM CDT MON MAY 11 2015/
DISCUSSION...OTHER THAN THE IMPRESSIVE SUPERCELL THAT SAT OVER
SOUTHERN DUVAL COUNTY FOR AWHILE BEFORE MOVING EAST-SOUTHEAST TO
THE FALFURRIAS AREA...CONVECTION HAS BEEN GENERALLY DISORGANIZED.
SURFACE TO 6 KM SHEAR WAS NOT QUITE AS STRONG AS ANTICIPATED AS
WELL AS SLIGHTLY LOWER INSTABILITY DUE TO CLOUD COVER. BUT 00Z CRP
SOUNDING STILL SHOWED MEAN LAYER CAPE AROUND 2500 J/KG AS MOISTURE
HAS INCREASED SUBSTANTIALLY WITH PRECIPITABLE WATER VALUES UP TO
2.15 INCHES. SLOW MOVING SUPERCELL OVER DUVAL COUNTY LIKELY
PRODUCED BETWEEN 7 AND 10 INCHES OF RAIN...BETWEEN BRUNI AND
REALITOS EARLIER THIS EVENING...AS STORM INGESTED THIS HIGHER
MOISTURE SOURCE ALONG THE COAST.
WATER VAPOR IMAGERY SHOWS A MID LEVEL SHORT WAVE TROUGH OVER
NORTHWEST MEXICO MOVING TO THE EAST. THE INCREASING MID AND UPPER
LEVEL FLOW ASSOCIATED WITH THIS SHORT WAVE TROUGH WILL MOVE OUT
OF NORTHEAST MEXICO INTO THE BRUSH COUNTRY OVERNIGHT. THIS WILL
INCREASE THE OVERALL SHEAR PROFILE THROUGH THE NIGHT. LATEST HI-
RES MODELS INDICATE THE POTENTIAL FOR A MORE ORGANIZED CONVECTIVE
COMPLEX TO FORM OVER THE RIO GRANDE PLAINS AND MOVE EAST-SOUTHEAST
LATER TONIGHT. INFRARED SATELLITE TRENDS SHOW COOLING CLOUD TOPS
WITH AREA OF CONVECTION FROM THE WESTERN HILL COUNTRY SOUTH TO
NORTHWEST OF LAREDO. HARD TO DISCERN WHERE FRONTAL BOUNDARY IS
WITH AREAS OF CONVECTION BUT THE BOUNDARY MAY BE OVER THE
NORTHERN COUNTIES AT THIS TIME. LOW LEVEL CONVERGENCE MAY BE
SLIGHTLY HIGHER NEAR THIS BOUNDARY WITH CONVECTION TO THE
NORTHWEST MOVING ALONG IT. WILL REMOVE THE MENTION OF SEVERE FOR
THE REST OF TONIGHT...ALTHOUGH THREAT FOR ISOLATED SEVERE STORMS
WILL STILL EXIST...AND RETAIN LOCALLY HEAVY RAINFALL IN FORECAST.
NO CHANGES MADE TO THE FLASH FLOOD WATCH AREA WITH BETTER THREAT
NEAR THE BOUNDARY AND OVER THE BRUSH COUNTRY AS ACTIVITY MOVES IN
FROM THE WEST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 81 74 81 74 85 / 70 60 40 50 50
VICTORIA 80 70 81 72 84 / 70 60 50 50 50
LAREDO 82 71 84 71 88 / 80 70 60 60 50
ALICE 82 72 83 72 87 / 70 60 40 60 50
ROCKPORT 80 75 80 74 83 / 70 60 40 50 50
COTULLA 78 69 83 70 88 / 90 80 70 60 50
KINGSVILLE 83 73 83 73 87 / 70 60 40 50 50
NAVY CORPUS 80 75 80 75 83 / 70 60 40 50 50
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE FOLLOWING
ZONES: BEE...DUVAL...GOLIAD...LA SALLE...LIVE OAK...
MCMULLEN...VICTORIA...WEBB.
GM...NONE.
&&
$$
TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS LINCOLN IL
943 AM CDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 943 AM CDT TUE MAY 12 2015
MAIN STRATOCUMULUS SHIELD BASICALLY MADE IT DOWN TO THE I-74
CORRIDOR WITH SOME SCATTERED CLOUDS AS FAR SOUTH AS MATTOON AND
LAWRENCEVILLE...BUT THESE SHOULD CONTINUE TO PULL BACK NORTHWARD
THROUGH MIDDAY. HOWEVER...LATEST RAP GUIDANCE SUGGESTS THE CLOUDS
HOLDING ON A BIT LONGER AROUND CHAMPAIGN AND DANVILLE. CURRENTLY
SEEING SOME WIND GUSTS OF 25-30 MPH...WHICH SHOULD CONTINUE INTO
MID AFTERNOON. TEMPERATURES CURRENTLY ON TRACK AND ONLY REQUIRED
SOME MINOR TWEAKS. UPDATES TO THE ZONES/GRIDS WERE MAINLY DONE FOR
THE SKY COVER AND WIND TRENDS.
&&
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT TUE MAY 12 2015
07Z/2AM SURFACE ANALYSIS SHOWS 1001MB LOW OVER THE NORTHERN GREAT
LAKES WHILE A 1025MB HIGH BUILDS INTO THE CENTRAL PLAINS. PRESSURE
GRADIENT BETWEEN THESE TWO FEATURES WILL REMAIN TIGHT ENOUGH TO
PRODUCE BRISK WESTERLY WINDS ACROSS CENTRAL ILLINOIS TODAY.
SUSTAINED WINDS WILL GENERALLY BE IN THE 10 TO 15 MPH RANGE...BUT
GUSTS COULD REACH 25 TO 30 MPH AS MIXING TAKES PLACE LATER THIS
MORNING. LATEST VWP NETWORK SHOWS 925MB WINDS OF 40 TO 45 MPH AND
THINK SOME OF THIS HIGHER MOMENTUM AIR WILL GET MIXED DOWN TO THE
SURFACE ONCE MORNING INVERSION IS BROKEN. PRESSURE GRADIENT WILL
TEND TO RELAX AS THE DAY PROGRESSES...SO GUSTS WILL BEGIN TO SLOWLY
SUBSIDE BY MID-AFTERNOON. LOW CLOUDS CURRENTLY ALONG/NORTH OF A
RUSHVILLE TO BLOOMINGTON LINE WILL LIFT NORTHEASTWARD AND CLEAR OUT
OF THE AREA BY MID-MORNING...FOLLOWED BY MOSTLY SUNNY SKIES ACROSS
THE BOARD FOR THE REMAINDER OF THE DAY. AFTERNOON HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS...WITH READINGS
ONLY RISING INTO THE LOWER TO MIDDLE 60S.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 329 AM CDT TUE MAY 12 2015
HIGH PRESSURE WILL BUILD EASTWARD INTO THE MIDWEST TONIGHT...WITH
THE RIDGE AXIS EXPECTED TO BE POSITIONED RIGHT OVER ILLINOIS BY 12Z
WED. CLEAR SKIES AND LIGHT WINDS BENEATH THE RIDGE WILL ALLOW
EXCELLENT RADIATIONAL COOLING OF THE DRY AIRMASS TO TAKE
PLACE...RESULTING IN OVERNIGHT LOW TEMPERATURES IN THE LOWER TO
MIDDLE 40S. MAY EVEN SEE A FEW UPPER 30S IN FAVORED LOW-LYING
RURAL AREAS. THE HIGH WILL BEGIN TO SHIFT OFF TO THE EAST ON
WEDNESDAY...HOWEVER LOW-LEVEL FLOW WILL MAINTAIN A DISTINCT
EASTERLY COMPONENT. AS A RESULT...HIGH TEMPERATURES WILL REMAIN ON
THE COOL SIDE IN THE UPPER 60S TO AROUND 70 DEGREES.
UPPER HEIGHTS BEGIN TO RISE SIGNIFICANTLY BY THURSDAY AS DEEP UPPER
LOW OVER THE GULF OF ALASKA DROPS SOUTHEASTWARD AND REACHES THE
CALIFORNIA COAST...RESULTING IN DOWNSTREAM RIDGING ACROSS THE
CENTRAL AND EASTERN CONUS. A WEAK DISTURBANCE NOTED ON LATEST WATER
VAPOR IMAGERY OFF THE COAST OF SOUTHERN CALIFORNIA WILL GET EJECTED
NORTHEASTWARD BY THE DIGGING WEST COAST TROUGH...WITH THIS FEATURE
TRACKING INTO THE GREAT LAKES BY FRIDAY. MODELS ARE IN GOOD
AGREEMENT WITH THE TRACK AND TIMING OF THIS WAVE...WITH SOME MINOR
DISCREPANCIES ON HOW QUICKLY TO SPREAD PRECIP INTO ILLINOIS. GIVEN
INITIALLY VERY DRY AIRMASS IN PLACE BENEATH THE SURFACE
HIGH...PREFER A SLOWER ARRIVAL OF PRECIP. AS A RESULT...HAVE GONE
WITH A DRY FORECAST THROUGH THURSDAY MORNING EAST OF I-55 WITH LOW
CHANCE POPS DELAYED UNTIL AFTERNOON. FURTHER WEST...RAIN CHANCES
WILL INCREASE TO LIKELY ACROSS THE ILLINOIS RIVER VALLEY BY
AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS
MUCH OF THE AREA THURSDAY NIGHT...WITH THE BEST RAIN CHANCES FOCUSED
NORTH OF THE I-70 CORRIDOR. ONCE THE SHORT-WAVE SHIFTS INTO THE
GREAT LAKES...FORCING FOR ADDITIONAL PRECIP BECOMES MUCH WEAKER
FRIDAY AND SATURDAY. SEVERAL MODELS ARE HINTING THAT ANOTHER
WEAK WAVE EMBEDDED WITHIN THE SOUTHWESTERLY FLOW MAY ENHANCE
SHOWERS ACROSS SOUTHERN ILLINOIS INTO THE OHIO RIVER
VALLEY...HOWEVER VERY LITTLE FOCUS FOR ORGANIZED CONVECTION EXISTS
FURTHER NORTH ACROSS THE REMAINDER OF THE AREA. AS A
RESULT...WILL ONLY CARRY LOW CHANCE POPS THROUGH THE PERIOD.
DEEP UPPER LOW OVER CALIFORNIA WILL GRADUALLY EJECT NORTHEASTWARD
LATE IN THE WEEKEND. MODELS ARE IN GOOD AGREEMENT WITH THIS PROCESS
THROUGH 144 HOURS...THEN SOLUTIONS BEGIN TO DIVERGE AFTER THAT.
BOTH THE GFS AND ECMWF SHOW THE LOW TRACKING INTO THE DAKOTAS BY
SUNDAY EVENING...WITH CONVECTION DEVELOPING ALONG A TRAILING COLD
FRONT ACROSS THE PLAINS. THE ECMWF THEN BECOMES MORE PROGRESSIVE
WITH THE WAVE...AS IT OPENS UP AND PUSHES EASTWARD INTO THE NORTHERN
GREAT LAKES BY MONDAY. MEANWHILE...THE GFS KEEPS THE LOW CLOSED
LONGER AND IS THUS SLOWER WITH ITS EASTWARD TRACK. THIS MAKES A BIG
DIFFERENCE WITH TIMING OF ASSOCIATED COLD FRONT...AS GFS LINGERS
THIS BOUNDARY AND RAIN CHANCES UNTIL TUESDAY. SINCE OVERALL
SYNOPTIC PATTERN HAS BEEN PROGRESSIVE OVER THE PAST WEEK AND THE GEM
SUPPORTS THE ECMWF...WILL BE GOING WITH THE FASTER ECMWF/GEM
SOLUTION IN THE EXTENDED. AS A RESULT...WILL BRING LIKELY POPS INTO
THE FAR WESTERN CWA SUNDAY AFTERNOON...THEN FURTHER EAST ACROSS THE
REMAINDER OF THE AREA SUNDAY NIGHT. WILL THEN BEGIN TO SHIFT THE
RAIN CHANCES OUT OF THE PICTURE ON MONDAY...WITH DRY WEATHER
RETURNING MONDAY NIGHT AND TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 600 AM CDT TUE MAY 12 2015
VFR CIGS EXPECTED TO PUSH OFF TO OUR EAST THIS MORNING BASED ON
CURRENT TRENDS IN SATELLITE DATA AND LATEST FORECAST SOUNDINGS.
CIG BASES HAVE BEEN FROM 3500 TO 4500 FEET WITH SOME LOWER...MVFR
CIGS...NOTED TO OUR NORTHWEST AND NORTH. THOSE ARE EXPECTED TO
REMAIN JUST TO THE NORTH OF PIA AND BMI THIS MORNING. SPI...DEC
AND CMI HAVE BEEN RIGHT ON THE EDGE OF THE VFR CIGS AND EXPECT
THOSE AREAS TO SEE SOME SCT-BKN CIGS FOR A TIME THIS MORNING WITH
THE MAIN AREA OF OVR CIGS TO THE NORTH.
GUSTY WINDS WILL CONTINUE TODAY WITH FORECAST SOUNDINGS SUGGESTING
WIND GUSTS TO AROUND 25 KTS AT TIMES OUT OF THE WEST AND THEN
NORTHWEST THIS AFTERNOON. LOOK FOR THE WINDS TO RAPIDLY DIMINISH
JUST AFTER SUNSET AS HIGH PRESSURE SETTLES IN OVERNIGHT WITH VFR
CONDITIONS CONTINUING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
630 AM CDT TUE MAY 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT TUE MAY 12 2015
HIGH PRESSURE CENTERED ACROSS KS MOVES EAST INTO
MISSOURI TODAY. LOW PRESSURE WILL BEGIN TO ORGANIZE ACROSS THE NRN
HIGH PLAINS THIS AFTERNOON. THE MODEL CONSENSUS SHOWS STRONG RETURN
FLOW DEVELOPING THIS AFTERNOON WITH SOUTH WINDS INCREASING TO 20 TO
30 MPH ACROSS WRN NEB. THESE WINDS SHOULD CONTINUE TONIGHT AS THE
LOW LEVEL JET FORMS AND STRENGTHENS TO AROUND 50 KT.
THE TEMPERATURE FORECAST TODAY FOLLOWS THE WARMER SIDE OF THE MODEL
CONSENSUS. SEVERAL MODELS WERE VERY COLD WITH HIGHS IN THE 60S WHILE
THE RAP WAS VERY WARM WITH HIGHS IN THE UPPER 70S. THE FORECAST IS
FOR HIGHS IN THE UPPER 60S TO MID 70S.
LOWS TONIGHT FALL INTO THE UPPER 40S TO AROUND 50. SOUTH WINDS AT 15
TO 20 MPH SHOULD KEEPS LOWS MILD.
LASTLY...THE MODELS SHOW A WEAK DISTURBANCE FIRING THUNDERSTORMS ON
THE LARAMIE AND FRONT RANGES LATE THIS AFTERNOON AROUND 21Z WHICH
CARRY EAST TOWARD WESTERN NEBRASKA. THE BEST GUESS IS FOR ISOLATED
SPRINKLES THIS EVENING. THE GFS WAS THE WET MODEL WHICH ACTUALLY
SHOWS SOME MEASURABLE QPF.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM CDT TUE MAY 12 2015
MODELS CONTINUE TO ADVERTISE A RAPID RETURN OF GULF MOISTURE TAKING
PLACE WEDNESDAY...WITH MODELS PROJECTING 850 MB DEW POINTS IN THE
10 TO 12C RANGE BY WEDNESDAY EVENING ACROSS THE REGION.
A LARGE UPPER TROUGH WILL BE TAKING SHAPE ALONG THE WEST COAST MID
TO LATE WEEK...WITH A LEAD SHORTWAVE EJECTING NORTHEAST THROUGH THE
PLAINS AHEAD OF THE TROUGH WEDNESDAY NIGHT INTO THURSDAY. THIS
SYSTEM IS SHOWN TO HAVE SOMEWHAT OF A NEGATIVE TILT...WHICH WILL
HELP DRAW MOISTURE WESTWARD INTO THE HIGH PLAINS. THE COMBINATION OF
STRONG LIFT AND MOISTURE TRANSPORT ON A SOUTHERLY LOW LEVEL
JET...CONTINUES TO GIVE CONFIDENCE THAT PRECIPITATION SHOULD RESULT
LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. WILL MAINTAIN THE
LIKELY POPS ALONG AND EAST OF HIGHWAY 83 WEDNESDAY NIGHT...AND ALSO
INTRODUCE EVENING LIKELY POPS ALONG A SURFACE TROUGH ACROSS THE
PANHANDLE INTO THE WESTERN SANDHILLS.
THE LEAD WAVE QUICKLY PASSES AND MOVES NORTHEAST AWAY FROM THE AREA
THURSDAY. ATTENTION THEN TURNS TO THE LONG WAVE TROUGH ALONG THE
WEST COAST. MODELS/ENSEMBLES PROJECT THIS TO MOVE EAST AS A CLOSED
SYSTEM DURING THE WEEKEND. THE GENERAL CONSENSUS IN THE MODELS AND
ENSEMBLE MEAN IS FOR THE CENTER OF THE SYSTEM TO TRACK ACROSS
WYOMING INTO SOUTH DAKOTA. THIS PUTS OUR AREA IN THE WARM MOIST
SECTOR. INSTABILITY LOOKS TO BE STRONG...AND AS DEEP LAYER SHEAR
INCREASES...STRONG TO SEVERE STORMS WILL LIKELY RESULT. WILL
INTRODUCE THE POTENTIAL FOR SEVERE THUNDERSTORMS IN THE HAZARDOUS
WEATHER OUTLOOK FOR FRIDAY AND SATURDAY. THE GFS AND ECMWF CONTINUE
TO DIFFER SOMEWHAT ON THE LOW LEVEL BOUNDARY PLACEMENT...BUT THE
LATEST TREND IS TO HOLD THE DRY LINE BACK TO THE WEST ACROSS WESTERN
NEBRASKA INTO WESTERN KANSAS...WHICH WOULD PLACE SEVERE STORM
DEVELOPMENT ACROSS THE FORECAST AREA OF WESTERN AND NORTH CENTRAL
NEBRASKA. WE WILL LIKELY BE IN THE MIDST OF THE MID LEVEL DRY SLOT
SUNDAY AS THE STORM SYSTEM CROSSES THE DAKOTAS...BUT AT LEAST SOME
CHANCE FOR SHOWERS IN WRAP AROUND PATTERN ACROSS NORTHERN NEBRASKA.
DRY WEATHER FOR MONDAY...THEN MORE CHANCES FOR RAIN NEXT WEEK BEYOND
THE FORECAST PERIOD...AS THE NEXT DEEP TROUGH MOVES EAST INTO THE
WESTERN CONUS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 630 AM CDT TUE MAY 12 2015
VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT.
STRONG SOUTH WINDS DEVELOP TODAY INCREASING TO 18020G32KT.
ISOLATED TSTMS ARE EXPECTED ACROSS THE LARAMIE AND COLORADO FRONT
RANGES AOA 21Z THIS AFTN. THERE IS A SLIGHT CHANCE THESE STORMS
COULD REACH WRN NEB THIS EVENING IN THE FORM OF -SHRA/SPRINKLES.
&&
.HYDROLOGY...
ISSUED AT 359 AM CDT TUE MAY 12 2015
THE COMBINATION OF SEASONAL SNOW MELT IN THE UPPER SOUTH PLATTE
RIVER BASIN AND RECENT HEAVY PRECIPITATION OVER WESTERN NEBRASKA AND
NORTHEAST COLORADO WILL LEAD TO FLOODING ON THE SOUTH PLATTE AND
PLATTE RIVERS IN SOUTHWEST NEBRASKA LATER THIS WEEK AND INTO EARLY
NEXT WEEK. AT THIS TIME SOME UNCERTAINTY STILL REMAINS WITH THE
FORECAST AS KEY UPSTREAM GAUGES IN NORTHEAST COLORADO HAVE YET TO
CREST. HOWEVER...LATEST PROJECTIONS CONTINUE TO HIGHLIGHT AN
INCREASING THREAT FOR SIGNIFICANT FLOODING TO OCCUR...POTENTIALLY
NEAR SEPTEMBER 2013 FLOOD LEVELS.
RIVER STAGE FORECASTS WILL BE CLOSELY MONITORED AND UPDATED ONCE
MORE UPSTREAM RIVER DATA BECOMES AVAILABLE. PERSONS THAT LIVE IN
VULNERABLE AREAS ALONG THE SOUTH PLATTE RIVER AND PLATTE RIVER IN
SOUTHWEST NEBRASKA SHOULD PAY CLOSE ATTENTION TO FLOOD FORECASTS IN
THE COMING DAYS AND BE PREPARED TO TAKE PROPER ACTION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR
NEZ006>010-026>029-038-058-059-069>071.
FREEZE WARNING UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR NEZ004-
005-022>025-035>037-056-057-094.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
HYDROLOGY...MARTIN/TAYLOR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1049 AM EDT TUE MAY 12 2015
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AHEAD OF A
COLD FRONT. LESS HUMID AIR ARRIVES ON WEDNESDAY AND SHOULD LAST INTO
THURSDAY AS HIGH PRESSURE MOVES OVERHEAD. THE LATTER PART OF THE
WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND
THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...HOT AND HUMID DAY ONGOING ACROSS THE CWA
EVEN AT THIS EARLY HOUR. AFTER STARTING FROM LOWS AROUND 70...TEMPS
ARE SHOOTING UP QUICKLY THIS MORNING THANKS TO 950MB TEMPS CLOSE TO
22C ON THE 8AM KCHS U/A SOUNDING. HIGH PRESSURE CENTERED WELL
OFFSHORE IS PUMPING RETURN FLOW INTO THE CAROLINAS...WHICH IS
STRENGTHENING WARM ADVECTION IN A PRE-FRONTAL AIRMASS. THE
COMBINATION OF THIS HEAT AND DEWPOINT TEMPS AROUND 70 WILL DRIVE
HEAT INDICES INTO THE MID 90S AWAY FROM THE COAST TODAY...THE MOST
UNCOMFORTABLE DAY OF 2015 SO FAR.
THIS HUMID AIR MASS WILL DRIVE INSTABILITY THIS AFTN...AND
CONVECTION IS ONCE AGAIN EXPECTED ACROSS THE AREA. VERY STEEP LR`S
UP TO 800MB WILL DRIVE RAPID UPDRAFTS...AND SBCAPE IS FORECAST TO
RISE TO AROUND 3000 J/KG...POSSIBLY HIGHER RIGHT ALONG THE SEA
BREEZE. THIS WILL SERVE AS THE FUEL FOR STORMS TODAY...WHICH SHOULD
DEVELOP ALONG THE SEA BREEZE...AND THEN LATER ALONG A PRE-FRONTAL
TROUGH APPROACHING FROM THE WEST. WHILE RESIDUAL BOUNDARIES MAY FIRE
WEAK STORMS...MID LEVEL TEMPS ARE NOT EXCEEDINGLY COOL (-8C AT
500MB) SO WIDESPREAD STRONG UPDRAFTS ARE NOT ANTICIPATED.
STILL...ENOUGH FORCING WILL DRIVE PARCELS UP INTO DECENT HAIL-ZONE
INSTABILITY...AND AN INVERTED-V TYPE SIGNATURE IS PROGGED WELL
INLAND AHEAD OF THE PRE-FRONTAL TROUGH. BULK-SHEAR VALUES STRUGGLE
TO AROUND 20 KTS...SO WIDESPREAD STORM ORGANIZATION IS
UNLIKELY...BUT PULSE STORMS AND AT LEAST SOME LINEAR FEATURES ALONG
THE PRE-FRONTAL TROUGH WILL HAVE THE POTENTIAL TO PRODUCE AN
ISOLATED WIND GUST OR LARGE HAIL STONE THIS AFTN. HIGH-RES HRRR AND
NSSL WRF SUGGEST ONLY ISOLATED STORMS UNTIL THE PRE-FRONTAL TROUGH
THIS EVENING...WHICH WILL BE THE PRIMARY DRIVER OF CONVECTION TODAY.
BY THIS EVENING HOWEVER...WE BEGIN TO LOSE HEATING...AND HAVE CAPPED
POP IN THE HIGH CHC RANGE. HIGHEST PROBABILITY FOR STORMS LOOKS TO
BE ACROSS THE MIDDLE-PART OF THE CWA WHERE THE WESTWARD ADVANCING
SEA BREEZE WILL INTERACT WITH THE EASTWARD MOVING TROUGH.
CONVECTION WILL WANE AFTER DARK...AND LITTLE FANFARE IS EXPECTED
WITH THE ACTUAL FROPA TONIGHT. HOWEVER...A SIGNIFICANT AIRMASS
CHANGE WILL ACCOMPANY THIS FRONT...WITH MUCH DRIER AIR AND LOWS
DROPPING INTO THE MID 60S AT THE COAST...AROUND 60 WELL INLAND.
ALSO NEED TO NOTE A PERSISTENT AREA OF SEA-STRATUS FROM ABOUT NORTH
MYRTLE BEACH TO BALD HEAD ISLAND. SHELF WATERS MUST BE JUST COOL
ENOUGH TO TAP INTO THE IDEALIZED RESIDENCE PARCEL TIMES ENCOUNTERED
BY THE W/SW WINDS IN ORDER TO SATURATE IN THIS AREA. THE COMBINATION
OF THE BACKING WINDS WITHIN THE SEA BREEZE...AS WELL AS SIGNIFICANT
HEATING JUST INLAND...SHOULD BREAK APART THIS STRATUS BY EARLY
AFTN...BUT IT IS UNLIKELY THE NEAR-COAST AREA HERE WILL EXPERIENCE
THE HOT/HUMID/SUNNY DAY GOING ON ELSEWHERE ACROSS THE CWA.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY... SOME VERY PLEASANT WEATHER EXPECTED THROUGH THE
PERIOD. HIGH PRESSURE WELL TO OUR NORTH WILL SHOW LITTLE MOVEMENT
WEDNESDAY WHILE THE TUESDAY NIGHT COLD FRONT STALLS WELL TO OUR
SOUTH. IN BETWEEN THE TWO WE WILL SEE A N TO NE FLOW LOCALLY THAT
WILL BRING SOME MUCH LOWER DEWPOINTS. A MILD LEVEL RIDGE WILL BE
JUST TO OUR WEST ALLOWING FOR DEEP LAYER DRY AIR AND AMPLE SUNSHINE.
ON THURSDAY THE HIGH WILL MOVE CLOSER TO THE REGION KEEPING
TEMPERATURES A BIT BELOW CLIMATOLOGY. A LITTLE MOISTURE RETURN MAY
GET UNDERWAY THURSDAY NIGHT AS THE HIGH MOVES FURTHER TO THE EAST,
MAINLY OVER WESTERN ZONE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...RETURN FLOW ON FRIDAY AND SATURDAY AS HIGH
PRESSURE SITES OFF THE COAST. THE MID LEVEL RIDGE WILL BE OVERHEAD
HOWEVER PRECLUDING DEEP MOISTURE AND CONFINING IT TO THE LOWER
LEVELS. SO WHILE A STRAY SHOWER OR THUNDERSTORM CANNOT BE RULED
OUT ANY COVERAGE SHOULD BE MINIMAL. OVER THE WEEKEND AND EVEN INTO
MONDAY FOR THAT MATTER THE MID LEVEL RIDGING APPEARS TO RESURGE.
DESPITE THIS THE GFS AND ECMWF BOTH DEPICT AN INCREASE IN
PRECIPITATION COVERAGE. WHILE THE CONTINUED MOISTENING OF THE LOW
LEVELS DOES IN FACT ARGUE FOR THIS THE MID LEVEL DRYNESS PROBABLY
MEANS THAT ITS RATHER SUBTLE. TEMPERATURES MEANWHILE WILL GROW
WARMER EACH DAY AND NIGHT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...RETURN FLOW ON FRIDAY AND SATURDAY AS HIGH
PRESSURE SITES OFF THE COAST. THE MID LEVEL RIDGE WILL BE OVERHEAD
HOWEVER PRECLUDING DEEP MOISTURE AND CONFINING IT TO THE LOWER
LEVELS. SO WHILE A STRAY SHOWER OR THUNDERSTORM CANNOT BE RULED
OUT ANY COVERAGE SHOULD BE MINIMAL. OVER THE WEEKEND AND EVEN INTO
MONDAY FOR THAT MATTER THE MID LEVEL RIDGING APPEARS TO RESURGE.
DESPITE THIS THE GFS AND ECMWF BOTH DEPICT AN INCREASE IN
PRECIPITATION COVERAGE. WHILE THE CONTINUED MOISTENING OF THE LOW
LEVELS DOES IN FACT ARGUE FOR THIS THE MID LEVEL DRYNESS PROBABLY
MEANS THAT ITS RATHER SUBTLE. TEMPERATURES MEANWHILE WILL GROW
WARMER EACH DAY AND NIGHT.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...MID/HIGH CLOUDS ARE DECREASING FROM NW-SE WITH PATCHY
IFR/MVFR CLOUDS MOVING SW-NE. AT KFLO IFR CIGS ARE OCCURRING. AT
KCRE IFR/LIFR MARINE STRATUS IS OCCURRING AND MOVING NNE AND
LIFTING INTO A MVFR LAYER AT KILM. WINDS ARE SSW 4-10 KTS.
EXPECT LITTLE CHANGE OVER THE NEXT COUPLE OF HOURS. LOW CIGS WILL
GRADUALLY BECOME VFR MID-LATE MORNING AS HEATING BEGINS. THEN
THERE IS MODERATE TO HIGH CONFIDENCE VFR WILL PERSIST FOR THE
REMAINDER OF THE TAF VALID PERIOD.
A COLD FRONT WILL APPROACH AND MOVE THROUGH THE TERMINALS THIS TAF
PERIOD. WINDS WILL INCREASE THIS MORNING WITH GUSTS TO AROUND 20KT.
IT WILL BE UNSTABLE ENOUGH FOR SHOWERS AND THUNDERSTORMS TO DEVELOP.
APPEARS MOST WILL DEVELOP BETWEEN THE INLAND AND COASTAL TERMINALS.
WILL INDICATE VCSH IN TAFS AND AMEND LATER IF NECESSARY. CONVECTION
SHOULD TAPER OFF IN THE EVENING. THE COLD FRONT WILL MOVE THROUGH
DURING THE LATE EVENING AND OVERNIGHT HOURS.
EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...HIGH PRESSURE OFFSHORE IS THE DOMINANT
SYNOPTIC FEATURE ACROSS THE WATERS TODAY...DRIVING SW FLOW AND WINDS
OF 10-15 KTS ACROSS THE WATERS. LOCAL ENHANCEMENTS OF UP TO 20
KTS...ALONG WITH A BACKING IN DIRECTION TO THE SOUTH...IS LIKELY
ALONG THE SEA BREEZE THROUGH THE AFTN AS WELL. OTHER THAN SOME
CHOPPY WATERS WITHIN THE NEAR SHORE WATERS THANKS TO THE SEA
BREEZE...WAVE HEIGHTS ARE EXPECTED TO PERSIST AT 2-4 FT WITH A 6-7
SEC PERIOD DOMINANT. A COLD FRONT WILL CROSS THE WATERS LATE TONIGHT
TURNING WINDS TO THE N/NW AT AROUND 15 KTS...AND PUSHING THE HIGHEST
SEAS AWAY FROM THE COAST.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM TUESDAY... TUESDAY NIGHT`S FROPA WILL BRING A
NORTHERLY FLOW ON WEDNESDAY. SURFACE HIGH REMAINS UP IN THE GREAT
LAKES SO THE FLOW WILL BE QUITE LIGHT LOCALLY AND SEAS LIKELY JUST
2 TO 3 FT. JUST A SLIGHT VEER WEDNESDAY NIGHT WITH FLOW POSSIBLY
GOING LIGHT AND VARIABLE FOR A TIME. THE HIGH EXTENDS JUST
SLIGHTLY SOUTH ON THURSDAY WHILE PROGRESSING EAST. NE WINDS COULD
INCREASE BY A CATEGORY AND BECOME A LITTLE GUSTY. THE COAST-
PARALLEL FLOW WILL PRECLUDE MUCH BUILDING OF SEAS HOWEVER.
.LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY... THE HIGH TO OUR NORTH PROGRESSES FURTHER
EAST ON FRIDAY LEADING TO MORE VEERING LOCALLY. FRIDAY MAY SEE
ONSHORE/EASTERLY FLOW MOST OF THE DAY WHILE A SOUTHERLY COMPONENT
TRIES TO GET ESTABLISHED MAINLY OVER SOUTHERN ZONES. ON SATURDAY
WE TRANSITION TO A FAIRLY NORMAL RETURN FLOW AROUND HIGH PRESSURE
OFF THE EAST COAST. NOT A BERMUDA HIGH THOUGH WHICH TYPICALLY
BRINGS SOUTHWESTERLY FLOW...THE WEEKEND WILL LIKELY SEE SOUTHEAST
INSTEAD. THERE COULD BE A VERY GRADUAL INCREASE IN WAVE PERIOD AS
A SWELL BECOMES ESTABLISHED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$ SYNOPSIS...MBB
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...MRR
MARINE...JDW/MBB
AREA FORECAST DISCUSSION
NWS NORMAN OK
1100 AM CDT TUE MAY 12 2015
.UPDATE...
ADJUSTMENTS TO CLOUD COVER AND TEMPERATURES.
&&
.DISCUSSION...
ALTHOUGH MID-HIGH CLOUDS WILL THIN SOMEWHAT FROM WEST TO EAST
THROUGH THE AFTERNOON...MOST AREAS OUTSIDE OF FAR NORTH/WEST
OKLAHOMA WILL STAY MOSTLY CLOUDY TODAY AND WILL KEEP TEMPS FROM
GETTING TOO WARM. INCREASED CLOUD COVER AND LOWERED HIGHS A FEW
DEGREES NEAR AND SOUTH OF OKC.
A FEW SPRINKLES MAY MOVE INTO WESTERN NORTH TEXAS THIS AFTERNOON
BUT MAIN RAIN EVENT STILL APPEARS TO COMMENCE AFTER MIDNIGHT
TONIGHT AND MAINLY DURING THE DAY TOMORROW. FLASH FLOOD WATCH WILL
BE CONTINUED FOR LATE TONIGHT AND TOMORROW. LATEST RUN OF MODELS
LOOKS FAVORABLE FOR HEAVIER RAIN AXIS TO BE FARTHER WEST...SOME OF
WHICH WILL BE JUST OUTSIDE OF CURRENT WATCH. HOWEVER...AREAS WEST
OF THE FLASH FLOOD WATCH CAN TAKE MUCH MORE RAIN THAN THE RAIN
SOAKED CENTRAL/SOUTHEAST OKLAHOMA. WE WILL TAKE A CLOSER LOOK TO
EXPANDING THE WATCH BUT IT WILL NOT BE DONE WITH THIS UPDATE.
ALTHOUGH SEVERE WEATHER DOES LOOK POSSIBLE FRIDAY...STILL APPEARS
THAT SATURDAY COULD BE THE PRIMARY IMPACT DAY FOR SEVERE WEATHER.
&&
.PREV DISCUSSION... /ISSUED 615 AM CDT TUE MAY 12 2015/
AVIATION...
12Z TAFS...THIN BAND OF SHOWERS AND EMBEDDED STORMS ACROSS CENTRAL
AND WEST TEXAS IS EXPECTED TO REMAIN SOUTH OF TAF SITES
THROUGH THE DAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH
6Z...BEFORE CEILINGS LOWER ACROSS WESTERN NORTH TEXAS AND
SOUTHWEST OKLAHOMA AS PRECIPITATION DEVELOPS.
PREV DISCUSSION... /ISSUED 325 AM CDT TUE MAY 12 2015/
DISCUSSION...
EAST TO SOUTHEAST WINDS WILL DEVELOP TODAY AS SURFACE HIGH
PRESSURE OVER KANSAS BUILDS EAST. MEANWHILE...CONVECTION ALONG
THE EAST TEXAS COAST WILL DELAY THE RETURN OF DEEP MOISTURE
NORTHWARD. SCATTERED SHOWERS AND A FEW STORMS HAVE FORMED WITHIN
AN AREA OF MID-LEVEL MOISTURE RETURN OVER CENTRAL AND WEST TEXAS.
THE HRRR SORTA HAS A HANDLE ON THIS AND GRADUALLY WEAKENS IT
DURING THE MORNING...WHILE THE NAM12 IS MORE AGGRESSIVE IN
DEVELOPING CONVECTION IN WESTERN NORTH TEXAS. FOR NOW WILL KEEP
IN CHANCE POPS FOR OUR TEXAS COUNTIES.
ANOTHER HEAVY RAIN EVENT SEEMS LIKELY LATE TUESDAY NIGHT INTO
WEDNESDAY. MODELS ARE SIMILAR IN TRACKING A PROGRESSIVE TROUGH
ACROSS THE SOUTHWESTERN STATES TONIGHT AND THEN OVER WEST TEXAS
AND OKLAHOMA WEDNESDAY INTO EARLY THURSDAY. DEEP MOISTURE IN PLACE
OVER SOUTH TEXAS WILL BE TRANSPORTED NORTHWARD TONIGHT INTO
WEDNESDAY IN ADVANCE OF THE TROUGH. THE BEST COMBINATION OF UPPER
AND LOW LEVEL JET FEATURES...SHOULD FOCUS THE HEAVIEST RAIN OVER
WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA EARLY WEDNESDAY...WITH
A GRADUALLY SHIFT NORTH AND EAST DURING THE AFTERNOON AND NIGHT.
WIDESPREAD 2 INCH RAIN AMOUNTS ARE LIKELY WITH 3 TO 4 INCH TOTALS
POSSIBLE. WITH RECENT HEAVY RAIN OVER THE SOUTHERN HALF OF
OKLAHOMA AND NORTH TEXAS...FLOODING WILL AGAIN BE A CONCERN.
BRIEF SHORTWAVE RIDGING ON THURSDAY WILL KEEP RAIN CHANCES
LOW...BUT ANOTHER TROUGH WILL BEGIN TO SHIFT EASTWARD FRIDAY INTO
THE WEEKEND. BETTER INSTABILITY IS EXPECTED TO DEVELOP AHEAD OF
THIS SYSTEM WHICH WILL RESULT IN AN INCREASE IN SEVERE WEATHER
CHANCES FRIDAY INTO SATURDAY. ANOTHER FRONT IS EXPECTED TO PUSH
ACROSS THE SOUTHERN PLAINS SUNDAY INTO MONDAY WHICH WILL BRING
ANOTHER PERIOD OF DRY WEATHER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 70 56 67 62 / 0 30 100 100
HOBART OK 71 56 67 61 / 0 40 100 70
WICHITA FALLS TX 71 59 70 64 / 10 60 100 70
GAGE OK 70 53 66 56 / 0 20 80 60
PONCA CITY OK 71 53 66 59 / 0 10 70 100
DURANT OK 72 59 71 64 / 10 40 80 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
OKZ007-008-012-013-017>020-022>048-050>052.
TX...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
TXZ083>090.
&&
$$
11/84
AREA FORECAST DISCUSSION
NWS NORMAN OK
615 AM CDT TUE MAY 12 2015
.AVIATION...
12Z TAFS...THIN BAND OF SHOWERS AND EMBEDDED STORMS ACROSS CENTRAL
AND WEST TEXAS IS EXPECTED TO REMAIN SOUTH OF TAF SITES
THROUGH THE DAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH
6Z...BEFORE CEILINGS LOWER ACROSS WESTERN NORTH TEXAS AND
SOUTHWEST OKLAHOMA AS PRECIPITATION DEVELOPS.
&&
.PREV DISCUSSION... /ISSUED 325 AM CDT TUE MAY 12 2015/
DISCUSSION...
EAST TO SOUTHEAST WINDS WILL DEVELOP TODAY AS SURFACE HIGH
PRESSURE OVER KANSAS BUILDS EAST. MEANWHILE...CONVECTION ALONG
THE EAST TEXAS COAST WILL DELAY THE RETURN OF DEEP MOISTURE
NORTHWARD. SCATTERED SHOWERS AND A FEW STORMS HAVE FORMED WITHIN
AN AREA OF MID-LEVEL MOISTURE RETURN OVER CENTRAL AND WEST TEXAS.
THE HRRR SORTA HAS A HANDLE ON THIS AND GRADUALLY WEAKENS IT
DURING THE MORNING...WHILE THE NAM12 IS MORE AGGRESSIVE IN
DEVELOPING CONVECTION IN WESTERN NORTH TEXAS. FOR NOW WILL KEEP
IN CHANCE POPS FOR OUR TEXAS COUNTIES.
ANOTHER HEAVY RAIN EVENT SEEMS LIKELY LATE TUESDAY NIGHT INTO
WEDNESDAY. MODELS ARE SIMILAR IN TRACKING A PROGRESSIVE TROUGH
ACROSS THE SOUTHWESTERN STATES TONIGHT AND THEN OVER WEST TEXAS
AND OKLAHOMA WEDNESDAY INTO EARLY THURSDAY. DEEP MOISTURE IN PLACE
OVER SOUTH TEXAS WILL BE TRANSPORTED NORTHWARD TONIGHT INTO
WEDNESDAY IN ADVANCE OF THE TROUGH. THE BEST COMBINATION OF UPPER
AND LOW LEVEL JET FEATURES...SHOULD FOCUS THE HEAVIEST RAIN OVER
WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA EARLY WEDNESDAY...WITH
A GRADUALLY SHIFT NORTH AND EAST DURING THE AFTERNOON AND NIGHT.
WIDESPREAD 2 INCH RAIN AMOUNTS ARE LIKELY WITH 3 TO 4 INCH TOTALS
POSSIBLE. WITH RECENT HEAVY RAIN OVER THE SOUTHERN HALF OF
OKLAHOMA AND NORTH TEXAS...FLOODING WILL AGAIN BE A CONCERN.
BRIEF SHORTWAVE RIDGING ON THURSDAY WILL KEEP RAIN CHANCES
LOW...BUT ANOTHER TROUGH WILL BEGIN TO SHIFT EASTWARD FRIDAY INTO
THE WEEKEND. BETTER INSTABILITY IS EXPECTED TO DEVELOP AHEAD OF
THIS SYSTEM WHICH WILL RESULT IN AN INCREASE IN SEVERE WEATHER
CHANCES FRIDAY INTO SATURDAY. ANOTHER FRONT IS EXPECTED TO PUSH
ACROSS THE SOUTHERN PLAINS SUNDAY INTO MONDAY WHICH WILL BRING
ANOTHER PERIOD OF DRY WEATHER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 71 56 67 62 / 0 30 80 80
HOBART OK 71 56 67 61 / 0 40 90 70
WICHITA FALLS TX 72 59 70 64 / 10 60 90 70
GAGE OK 71 53 66 56 / 0 20 70 60
PONCA CITY OK 72 53 66 59 / 0 10 70 90
DURANT OK 73 59 71 64 / 10 40 80 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
OKZ007-008-012-013-017>020-022>048-050>052.
TX...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1136 AM EDT TUE MAY 12 2015
.SYNOPSIS...
OUR RECENT STRING OF WARM DAYS AND MILD NIGHTS WILL BE CUT TODAY
AS A STRONG COLD FRONT PUSHES EAST ACROSS THE STATE. COOLER...
DRIER AND WINDY CONDITIONS WILL ARRIVE DURING THE DAYLIGHT HOURS
TODAY...AND LAST THROUGH WEDNESDAY NIGHT. A LARGE AREA OF HIGH
PRESSURE WILL BECOME CENTERED OVER THE STATE WEDNESDAY NIGHT AND
EARLY THURSDAY. AS THE HIGH DRIFTS EAST AND OFF THE MID ATLANTIC
COAST...MILDER CONDITIONS WILL RETURN FOR THURSDAY AND FRIDAY AND
CONTINUE THIS WEEKEND AS ANOTHER UPPER RIDGE BUILDS ACROSS THE
REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT TRACKING ACROSS CENTRAL PA LATE THIS MORNING...
DELINEATED BY LINE OF SHALLOW CONVECTION. KBFD JUST HAD A PEAK
WIND OF 32 KTS AS THIS BAND MOVED ACROSS...IN LINE WITH PREVIOUS
EXPECTATIONS. HI RES HRRR AND 4KM SPC WRF AND MODEL SOUNDINGS
INDICATE A RIBBON OF A FEW TO SEVERAL HUNDRED J/KG AVAILABLE FOR
SHALLOW CONVECTION TO ACCOMPANY ITS PASSAGE ACROSS MOST OF CENTRAL
PA. HI RES SIMULATIONS DAMPEN CONVECTION OVER THE LOWER SUSQ LATER
TODAY DUE TO INCREASING DOWNSLOPE COMPONENT...BUT WE`LL LIKELY SEE
SOME GUSTY SHOWERS WITH ISOLATED THUNDER FOR MUCH OF THE EARLY
AFTERNOON AS THE FRONT SLIDES EAST. STRONG COLD ADVECTION AND
30-40 KT 850 MB WINDS WILL INCREASINGLY MIX BY THIS AFTERNOON
BEHIND THE FRONT...WITH FREQUENT GUSTS OF 30+ MPH REACHING THE
SFC.
HIGH TEMPS WILL RANGE FROM THE COOLISH M-U60S NW...TO THE LOWER
AND MID 80S IN THE SOUTHEAST /WHICH WILL BE ABOUT 10-12 DEG ABOVE
NORMAL FOR TODAY IN THE GREATER HARRISBURG...YORK...LANCASTER
AREA/.
EXTENSIVE...COLD AIR STRATO CU WILL SPREAD INTO THE WEST THIS
AFTERNOON...BUT BREAK UP AND FLATTEN OUT IN THE LLVL DOWNSLOPE AND
ADIABATIC WARMING/DRYING REGIME ACROSS THE CENTRAL VALLEYS AND
SUSQ REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
DEEPENING NW FLOW...WITH SHALLOW COLD AIR AT LLVLS WILL LEAD TO
GENERALLY PARTLY SKIES ACROSS THE SUSQ VALLEY....WITH MOSTLY CLOUD
TO CLOUDY CONDITIONS OVER THE MW MTNS.
THIS CLOUD DISTRIBUTION WILL HELP TO LESSEN THE NORMAL STRONG
NW/SE DIFF IN MIN TEMPS ACROSS THE STATE.
LOWS EARLY TUESDAY WILL BE IN THE UPPER 30S TO LOW 40S WEST...AND
IN THE U40S TO LOWER 50S THROUGHOUT THE SUSQEHANNA VALLEY
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
LATER SHIFTS WILL NEED TO MONITOR THE THREAT FOR FROST OR FREEZE
PRODUCTS WED NIGHT AS TEMPS WILL BE PLUMMETING INTO THE U20S/L30S
INVOF KBFD...AND MID 30S TO AROUND 40F AS YOU HEAD SE FROM THE
I99/RT200 CORRIDOR TWD INTERSTATE 81. LOWS ACROSS THE LOWER SUSQ
VALLEY SHOULD BE AOA 40F EARLY THURSDAY.
A FEW WEAK SYSTEMS CRESTING THE MEAN EASTERN U.S. UPPER RIDGE AND
DROPPING SE FROM THE GLAKES WILL BRING THE CHC OF SOME SHOWERS
FRIDAY AFTERNOON THROUGH SAT.
UPPER RIDGE SHARPENS OVER THE MID ATLANTIC REGION SAT NIGHT INTO
SUNDAY. WASHED OUT FRONT TO THE SOUTH OF THE STATE SAT NIGHT WILL
LIKELY RETURN NORTH AS A WARM FRONT SUNDAY...BRINGING BACK THE CHC
FOR SHOWERS/SCTD TSRA SUNDAY AFTERNOON INTO EARLY NEXT WEEK AHEAD
OF A STRONGER SYSTEM THAT WILL BE GRADUALLY SHEARING OUT AS IT
HEADS NE TWD THE GLAKES REGION.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
COLD FRONT AND NARROW BAND OF MVFR CIGS/SHRA WITH SFC WND G35
KTS SPREADING ACROSS NORTHERN AND CENTRAL AIRFIELDS. ASSOC DRIER
AIR WILL CAUSE CIGS TO BECOME VFR...EVEN OVR THE W MTNS THIS
AFTERNOON.
WIDESPREAD VFR CONDS EXPECTED FOR THE BALANCE OF THE DAY...AS
DRIER AIR FLOWS IN BEHIND COLD FRONT. MAIN CONCERN LATER TODAY
WILL BE THE GUSTY WEST WINDS...RESULTING FROM TIGHT PRESSURE
GRADIENT SOUTH OF LOW PRES OVR S QUEBEC. MDL SOUNDINGS SUPPORT
GUSTS BTWN 25-30KTS BY THIS AFTN. THE STRONGEST GUSTS WILL
DIMINISH AFTER SUNSET...BUT IT WILL REMAIN BREEZY OVERNIGHT.
OUTLOOK...
WED...NO SIG WX EXPECTED.
THU...EARLY AM FOG POSS NW MTNS.
FRI...PM SHRA/CIG REDUCTIONS POSS...MAINLY NW MTNS.
SAT...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
613 AM EDT TUE MAY 12 2015
.SYNOPSIS...
OUR RECENT STRING OF WARM DAYS AND MILD NIGHTS WILL BE CUT TODAY
AS A STRONG COLD FRONT PUSHES EAST ACROSS THE STATE. COOLER...
DRIER AND WINDY CONDITIONS WILL ARRIVE DURING THE DAYLIGHT HOURS
TODAY...AND LAST THROUGH WEDNESDAY NIGHT. A LARGE AREA OF HIGH
PRESSURE WILL BECOME CENTERED OVER THE STATE WEDNESDAY NIGHT AND
EARLY THURSDAY. AS THE HIGH DRIFTS EAST AND OFF THE MID ATLANTIC
COAST...MILDER CONDITIONS WILL RETURN FOR THURSDAY AND FRIDAY AND
CONTINUE THIS WEEKEND AS ANOTHER UPPER RIDGE BUILDS ACROSS THE
REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC-850 MB NORTH/SOUTH THETA-E RIDGE WAS SLIDING INTO THE EASTERN
HALF OF THE STATE AT 09Z...WITH JUST A FEW BRIEF SHOWERS OR
SPRINKLES RACING ENE.
SFC DEWPOINTS DROPPING OFF BY SEVERAL DEG F ACROSS WESTERN
PENN /TO THE WEST OF RT 219/...AND THIS MARKS THE WEAK...INITIAL
COLD FRONT THAT WILL SLIDE ACROSS MUCH OF THE FCST AREA BY 12Z.
COLD FRONT JUST PUSHED THROUGH KTOL OVER THE PAST HOUR...AND
WE/LL HAVE TO CONTENT WITH THIS WEATHER FEATURE DURING THE LATE
MORNING /WEST/ AND AFTERNOON HOURS /EAST/.
WELL DEFINED DRY SLOT WITHIN 50 MILES WITHER SIDE OF THE
FRONT...WILL BE PUSHING OVER THE CWA LATE THIS MORNING /WEST/ AND
DURING THE AFTERNOON /EAST/.
TEMPS WILL CLIMB ONLY ABOUT 5-7 DEG ACROSS THE ALLEGHENIES OF NW
PENN TODAY...WHILE THE CENTRAL AND SE VALLEYS SEE A TEMP INCREASE
OF 13 TO 15F TODAY.
HIGH TEMPS RANGING FROM THE U60S NW...TO THE MID 80S IN THE
SOUTHEAST WILL BE ABOUT 10-12 DEG ABOVE NORMAL FOR TODAY.
EXTENSIVE...COLD AIR STRATO CU WILL SPREAD INTO THE THIS
AFTERNOON...BUT BREAK UP AND FLATTEN OUT IN THE LLVL DOWNSLOPE
AND ADIABATIC WARMING/DRYING REGIME ACROSS THE CENTRAL VALLEYS
AND SUSQ REGION.
IN ADDITION...LATEST MODEL FORECAST SOUNDINGS INDICATE MODERATE
MIXING POTENTIAL WITH MANY AREAS SEEING WIND GUSTS IN THE 30-35
MPH RANGE /OR SLIGHTLY HIGHER/. EXPECT HIGHER TERRAIN OF THE
NORTH AND WEST TO SEE SCT -SHRA...WHILE CENTRAL AND SOUTHEAST
AREAS REMAIN PARTLY SUNNY AND DRY.
HIGHS WILL RANGE FROM JUST 60 TO 65F ACROSS THE NORTHWEST MTNS...TO
THE LOWER 80S THROUGHOUT THE LOWER SUSQ RIVER VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
DEEPENING NW FLOW...WITH SHALLOW COLD AIR AT LLVLS WILL LEAD TO
GENERALLY PARTLY SKIES ACROSS THE SUSQ VALLEY....WITH MOSTLY CLOUD
TO CLOUDY CONDITIONS OVER THE MW MTNS.
THIS CLOUD DISTRIBUTION WILL HELP TO LESSEN THE NORMAL STRONG DIFF
IN MIN TEMPS ACROSS CENTRAL PENN AND THE SUSQ VALLEY.
LOWS EARLY TUESDAY WILL BE IN THE UPPER 30S TO LOW 40S WEST...AND
IN THE U40S TO LOWER 50S THROUGHOUT THE SUSQEHANNA VALLEY
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
LATER SHIFTS WILL NEED TO MONITOR THE THREAT FOR FROST OR FREEZE
PRODUCTS WED NIGHT AS TEMPS WILL BE PLUMMETING INTO THE U20S/L30S
INVOF KBFD...AND MID 30S TO AROUND 40F AS YOU HEAD SE FROM THE
I99/RT200 CORRIDOR TWD INTERSTATE 81. LOWS ACROSS THE LOWER SUSQ
VALLEY SHOULD BE AOA 40F EARLY THURSDAY.
A FEW WEAK SYSTEMS CRESTING THE MEAN EASTERN U.S. UPPER RIDGE AND
DROPPING SE FROM THE GLAKES WILL BRING THE CHC OF SOME SHOWERS
FRIDAY AFTERNOON THROUGH SAT.
UPPER RIDGE SHARPENS OVER THE MID ATLANTIC REGION SAT NIGHT INTO
SUNDAY. WASHED OUT FRONT TO THE SOUTH OF THE STATE SAT NIGHT WILL
LIKELY RETURN NORTH AS A WARM FRONT SUNDAY...BRINGING BACK THE CHC
FOR SHOWERS/SCTD TSRA SUNDAY AFTERNOON INTO EARLY NEXT WEEK AHEAD
OF A STRONGER SYSTEM THAT WILL BE GRADUALLY SHEARING OUT AS IT
HEADS NE TWD THE GLAKES REGION.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
RADAR AT 06Z SHOWS ONE LINE OF SHRA/TSRA PUSHING THRU EASTERN PA
AND ANOTHER BATCH OF SHRA ASSOC WITH APPROACHING COLD FRONT OVER
WESTERN PA. FOR MUCH OF CENTRAL PA...NO SIG CIG/VIS REDUCTIONS
ARE EXPECTED EARLY THIS MORNING. THE EXCEPTION COULD BE KBFD AND
KJST...WHERE A BRIEF PERIOD OF IFR CIGS MAY DEVELOP AS PLUME OF
MOIST AIR ALONG COLD FRONT ASCENDS THE W MTNS. MDL RH TIMESECTIONS
AND HRRR OUTPUT SUGGEST THE WINDOW OF OPPORTUNITY FOR IFR CONDS AT
KBFD/KJST WILL BE 09Z-11Z. AFTER 11Z...DRIER AIR WILL ARRIVE ON
WEST WIND...CAUSING IMPROVING CONDS.
WIDESPREAD VFR CONDS EXPECTED AFTER SUNRISE...AS DRIER AIR FLOWS
IN BEHIND COLD FRONT. MAIN CONCERN TODAY WILL BE THE GUSTY WEST
WINDS...RESULTING FROM TIGHT PRESSURE GRADIENT SOUTH OF LOW PRES
OVR S QUEBEC. MDL SOUNDINGS SUPPORT GUSTS BTWN 25-30KTS BY THIS
AFTN. THE STRONGEST GUSTS WILL DIMINISH AFTER SUNSET...BUT IT
WILL REMAIN BREEZY OVERNIGHT.
OUTLOOK...
WED...NO SIG WX EXPECTED.
THU...EARLY AM FOG POSS NW MTNS.
FRI...PM SHRA/CIG REDUCTIONS POSS...MAINLY NW MTNS.
SAT...SCT PM TSRA IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
950 AM MDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 938 AM MDT TUE MAY 12 2015
15Z SURFACE ANALYSIS HAD FRONTAL BOUNDARY FROM NORTHWEST WY INTO
SOUTHWEST SD. LIFT UNDER RIGHT ENTRANCE REGION OF JET STREAK
ACROSS THE NORTHERN PLAINS ASSISTING SOME WEAKER RETURNS ON RADAR
ACROSS FAR NORTHEAST WY/SOUTHEAST MT/ENTERING NORTHWEST SD. MOST
OF IT NOT REACHING THE GROUND...AND LOOKING AT THE 12Z KUNR
SOUNDING THERE IS SOME DRY AIR TO OVERCOME.
12Z RAP SHOWS A BIT OF SBCAPE OVER THE HIGHER TERRAIN AS DECENT
SOUTHERLY FLOW FEEDS MOISTURE POOLING ALONG THE BOUNDARY SO HAVE
ADDED SMALL POPS LATER THIS AFTERNOON FOR THOSE AREAS.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 300 AM MDT TUE MAY 12 2015
WESTERN CONUS UPPER LEVEL TROUGHING ONGOING THIS MORNING WITH A
LOCAL WAA RESPONSE. WEAK LEAD IMPULSE FROM THIS SYSTEM WILL
SUPPORT INCREASING MID/HIGH CLOUDS THROUGH MORNING ACROSS THE
NORTHERN HALF...WITH A FEW SPRINKLES POSSIBLE ACROSS THE FAR
NORTH. MEANWHILE ANOTHER UPPER LEVEL IMPULSE WILL SHIFT NE INTO
THE SW CONUS AND SOUTHERN PLAINS. THIS SYSTEM WILL HELP SUPPORT
DEEPER MOISTURE NORTH INTO THE AREA THROUGH TONIGHT. ONGOING
PRESSURE FALLS PER THE ADVANCING WESTERN CONUS UPPER TROUGH WILL
SUPPORT A LLJ TONIGHT WITH SOME FORCING FOR ASCENT PER A SLOW
MOVING NW CONUS UPPER TROUGH GRAZING THE NORTHERN PLAINS TONIGHT.
STEEP MID LEVEL LAPSE RATE WITH AN FGEN RESPONSE AND INCREASING
ELEVATED INSTABILITY NOTED IN MU CAPES WILL SUPPORT A SLIGHT
CHANCE SHOWER/TS THREAT ACROSS THE NORTHERN HALF TONIGHT. HIRES
MODELS INCLUDING THE NAM SUGGEST AN ISOLD HIGH BASED SHRA/TS COULD
DEVELOP OVER NE WY THIS EVENING AS CIN IS MINIMIZED PER
INSOLATION...WITH ANY ACTIVITY BEING CARRIED NE BY A DEVELOPING
LLJ. DID ADJUST SLIGHT CHANCE POPS SW INTO NE WY AND THE BH AFTER
00Z THIS EVENING FOR THIS...WITH A SLIGHTLY EARLIER START TIME
POSSIBLE. LEE SIDE TROUGH WILL SHIFT EAST ACROSS THE FA WED
MORNING AND STALL WITH THE SOUTHERN PLAINS IMPULSE SHIFTING NORTH.
RENEWED FGEN FROM THIS SYSTEM WILL SUPPORT INCREASING LL
CONVERGENCE ALONG AND NEAR THE SFC TROUGH WHICH WILL BE SOMEWHERE
ACROSS THE EASTERN FA. INCREASING LL MOISTURE COMBINED WITH
DIURNAL INSTABILITY WILL ALLOW INCREASING CHANCES FOR SHRA/TS
THERE...WITH OTHER ACTIVITY POSSIBLE OVER THE BH AND NE WY PER
DIURNAL HEATING IN THE PRESENCE OF UNSTABLE PROFILES/WEAK CIN.
SHRA/TS CHANCES SHOULD INCREASE WED NIGHT AS THE LLJ SUSTAINED
WITH ONGOING MOISTURE TRANSPORT AND INCREASING LSA FROM THE
EXPECTED IMPULSE. BULK OF FORCING FROM THIS SYSTEM WILL REMAIN SE
OF THE FA...INCLUDING THE ASSOCIATED PRECIP CHANCES. HAVE RETAINED
HIGH CHANCE POPS...PRECLUDING LIKELY ATTM GIVEN CONVECTIVE
COMPONENT TO PRECIP.
AS FOR TEMPS...BUMPED HIGHS UP BOTH TODAY AND WED. SNOW PACK HAS
ERODED QUITE WELL OVER MUCH OF THE AREA...WITH THE DEEPEST SNOW
REMAINING OVER SW SD. STRONG SE WINDS UNDER MAY SUN SHOULD MIX
WARMER AIR DOWN WITH NO PROBLEM...THUS HAVE OPTED FOR TEMPS MORE
IN LINE WITH GUIDANCE.
.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 300 AM MDT TUE MAY 12 2015
THE UPPER LEVEL RIDGE WILL MOVE EAST OF THE AREA ON WEDNESDAY.
THIS WILL PUT THE AREA IN ACTIVE SOUTHWEST FLOW FOR MID WEEK INTO
THE WEEKEND...WITH DAILY CHANCES FOR RAIN SHOWERS AND SOME
THUNDERSTORMS. A FAST-MOVING SHORTWAVE WILL SWEEP THROUGH THE
CENTRAL CONUS WEDNESDAY NIGHT AND THURSDAY...AND THEN ANOTHER
UPPER LOW IS PROGGED TO MOVE ACROSS THE ROCKIES AND INTO THE
PLAINS THIS WEEKEND...BRINGING THE BEST CHANCES FOR ADDITIONAL
RAINFALL. MODELS ARE INDICATING AROUND A HALF INCH OF QPF BY THE
END OF THE WEEK...WITH AN ADDITIONAL INCH OR TWO DURING THE
WEEKEND. AS FAR AS TEMPERATURES GO...MORE SPRING LIKE READINGS ARE
EXPECTED FROM MID WEEK THROUGH THE WEEKEND. THEREFORE...THE
PRECIPITATION SHOULD REMAIN RAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 300 AM MDT TUE MAY 12 2015
GUSTY SOUTHERLY WINDS ARE EXPECTED OVER NORTHEASTERN WYOMING
DURING THE REST OF THE NIGHT. THERE IS A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS ON TUESDAY EVENING. LCL MVFR CIGS ARE POSSIBLE
WITH ANY SHOWERS OR THUNDERSTORMS...OTHERWISE VFR CIGS WILL
PREVAIL.
&&
.HYDROLOGY...
ISSUED AT 300 AM MDT TUE MAY 12 2015
RUNOFF FROM RAIN AND MELTING SNOW IS CAUSING RAPID RISES IN THE
LEVEL OF THE WHITE RIVER BETWEEN INTERIOR AND OACOMA. A FLOOD
WARNING HAS BEEN ISSUED FOR THAT AREA AS MINOR TO MODERATE
FLOODING IS FORECAST TO DEVELOP STARTING TUESDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...JC
LONG TERM...7
AVIATION...7
HYDROLOGY...JC
AREA FORECAST DISCUSSION
NWS TUCSON AZ
330 PM MST TUE MAY 12 2015
.SYNOPSIS...THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
MAINLY EAST OF TUCSON TONIGHT. DRY CONDITIONS WILL THEN PREVAIL
WEDNESDAY INTO THURSDAY. A STRONG LOW PRESSURE SYSTEM WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY INTO SATURDAY. COOLER
TEMPERATURES AND GUSTY WINDS WILL ACCOMPANY THIS SYSTEM. EXPECT DRY
CONDITIONS AND MUCH WARMER TEMPERATURES EARLY NEXT WEEK.
&&
.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY DEPICTED FAIRLY THICK MID
AND HIGH-LEVEL CLOUDS ACROSS MUCH OF SE ARIZONA THIS AFTERNOON. MORE
EXTENSIVE BREAKS IN THE OVERCAST WERE NOTED ACROSS WRN PIMA COUNTY.
THE BACK EDGE OF THIS CLOUD MASS REPRESENTING A SHORTWAVE TROUGH
AXIS EXTENDED FROM SRN CALIFORNIA SOUTHWARD TO NEAR THE BAJA
CALIFORNIA SPUR. MEANWHILE...A VERY DRY SURFACE ENVIRONMENT WAS
ONGOING WITH DEWPOINTS AT LOWER ELEVATIONS VALID 22Z RANGING FROM
THE MID TEENS TO MID 20S. HAVE FAVORED SEVERAL RUC HRRR SOLUTIONS
FOR PRECIP POTENTIAL THRU TONIGHT.
THUS...THERE IS A SLIGHT CHANCE OF SHOWERS/TSTMS THIS EVENING FROM
TUCSON EWD/SWD TO THE NEW MEXICO/INTERNATIONAL BORDERS. A SLIGHT
CHANCE OF SHOWERS CONTINUES MAINLY NEAR THE NEW MEXICO BORDER LATE
TONIGHT. GIVEN THE VERY DRY NEAR-SURFACE ENVIRONMENT...ANY
MEASURABLE PRECIP AMOUNTS WILL BE QUITE LIGHT. CLEARING SKIES WILL
OCCUR FROM WEST-TO-EAST LATE TONIGHT AS THE MID-LEVEL TROUGH AXIS
MOVES INTO SWRN NEW MEXICO.
FLOW ALOFT WILL BECOME INCREASINGLY SWLY WED-THUR IN RESPONSE TO
DEEPENING LOW PRESSURE ALOFT OVER THE ERN PACIFIC. THE TIGHTENING
MID-LEVEL GRADIENT WILL PRODUCE BREEZY TO WINDY CONDITIONS...
ESPECIALLY DURING THE AFTERNOON HOURS. EXPECT THE STRONGEST WIND
SPEEDS TO OCCUR THUR.
12/12Z GFS/ECMWF/CMC WERE IN GOOD AGREEMENT WITH DEPICTING A 550 DM
LOW TO BE CENTERED NEAR THE CENTRAL CALIFORNIA COAST FRI MORNING.
THIS UPPER LOW IS THEN PROGGED TO BE CENTERED OVER WYOMING SAT
MORNING...WITH A MID-LEVEL TROUGH AXIS TO EXTEND SWWD INTO SRN
ARIZONA. BASED ON THESE SOLUTIONS...APPEARS THE BEST CHANCE OF
MEASURABLE PRECIP FOR THE TUCSON METRO AREA WOULD OCCUR FRI NIGHT.
THE GRIDDED DATA POP FIELDS WERE ADJUSTED TO REFLECT THIS SCENARIO.
AT ANY RATE...THERE IS A SLIGHT CHANCE OF SHOWERS MAINLY NORTH OF
TUCSON FRI MORNING. PRECIP CHANCES INCREASE FRI AFTERNOON...AND A
CHANCE OF SHOWERS/TSTMS EXISTS ACROSS MUCH OF THE AREA FRI NIGHT. A
CHANCE OF SHOWERS CONTINUES SAT MAINLY ACROSS THE WHITE MOUNTAINS.
DRY CONDITIONS SHOULD OCCUR BY SAT AFTERNOON FROM TUCSON WWD ACROSS
THE WRN DESERTS. DRY CONDITIONS WILL PREVAIL AREA-WIDE LATE SAT
NIGHT AND CONTINUE THRU TUE UNDER GENERALLY SWLY FLOW ALOFT.
WARMER TEMPS WILL OCCUR WED FOLLOWED BY A FEW DEGS OF COOLING
THUR...THEN MORE SIGNIFICANT COOLING IS ON TAP FRI. MARKEDLY WARMER
TEMPS WILL PREVAIL SUN-TUE.
&&
.AVIATION...VALID THRU 14/00Z.
EXPECT ISOLATED -SHRA/-TSRA FROM KTUS VICINITY EASTWARD TO THE NEW
MEXICO BORDER THIS EVENING. ISOLATED -SHRA WILL THEN PREVAIL MAINLY
NEAR THE NEW MEXICO BORDER LATE TONIGHT...THEN DRY CONDITIONS WILL
OCCUR AREA-WIDE WEDNESDAY. OTHERWISE...CLOUD DECKS THRU ABOUT 06Z-
09Z WEDNESDAY WILL GENERALLY BE AT 6-12K FT AGL FOLLOWED BY
DECREASING CLOUDS EARLY WEDNESDAY MORNING. CLEAR SKIES TO SCATTERED
CLOUDS ABOVE 10K FT AGL WILL PREVAIL WEDNESDAY AFTERNOON. SURFACE
WIND EARLY THIS EVENING AND WEDNESDAY AFTERNOON WILL BE SLY/SWLY AT
12-20 KTS WITH GUSTS OF 20-30 KTS. SURFACE WIND WILL GENERALLY BE
LESS THAN 10 KTS AT OTHER TIMES. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...THERE IS A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS MAINLY EAST OF TUCSON TONIGHT. DRY CONDITIONS WILL
THEN PREVAIL WEDNESDAY INTO THURSDAY. THE COMBINATION OF STRONG AND
GUSTY WINDS AND LOW RELATIVE HUMIDITIES MAY CREATE CRITICAL FIRE
WEATHER CONDITIONS AT LOWER ELEVATIONS THURSDAY AFTERNOON AND EARLY
THURSDAY EVENING. HOWEVER...WIND SPEEDS AND RELATIVE HUMIDITIES
NEEDED TO ACHIEVE RED FLAG CRITERIA WILL BE MARGINAL AND SHORT-
LIVED. A STRONG STORM SYSTEM MOVING NORTH OF THE AREA WILL THEN
BRING A CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY INTO SATURDAY.
COOLER TEMPERATURES AND GUSTY WINDS WILL OCCUR WITH THIS SYSTEM.
EXPECT DRY CONDITIONS WITH MUCH WARMER TEMPERATURES EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 AM MST TUE MAY 12 2015
.SYNOPSIS...THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
EAST OF TUCSON THROUGH WEDNESDAY MORNING. OTHERWISE...DRY CONDITIONS
WILL PREVAIL INTO THURSDAY. A STRONG LOW PRESSURE SYSTEM FROM THE
EASTERN PACIFIC WILL THEN BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS THURSDAY NIGHT INTO SATURDAY. COOLER TEMPERATURES AND
GUSTY WINDS WILL ALSO OCCUR.
&&
.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE PARTLY CLOUDY SKIES ACROSS THE WHITE MOUNTAINS...AND MOSTLY
CLOUDY TO CLOUDY SKIES ELSEWHERE. THE THICKER CLOUDINESS AS PER
ENHANCED COLDER CLOUD TOPS EXTENDED FROM TUCSON SOUTHWARD TO THE
INTERNATIONAL BORDER. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z RANGED
FROM THE MID 20S-MID 40S. THESE TEMPS WERE NEARLY 2-5 DEGS F HIGHER
VERSUS 24 HOURS AGO EXCEPT IN THE VICINITY OF SAFFORD...WHERE THE
DEWPOINT WAS 15 DEGS HIGHER VERSUS THIS TIME MON.
SURFACE TEMPS VALID 16Z WERE GENERALLY 2-9 DEGS F COOLER VERSUS 24
HOURS AGO. 12/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS 0.40
INCH. THE PROFILE EXHIBITED A VERY DRY SURFACE-500 MB LAYER AND SOME
SATURATION OF THE COLUMN ABOVE 500 MB. 12/12Z UPPER AIR PLOTS
DEPICTED RIDGE AXIS FROM TEXAS NWWD INTO MONTANA...AND A 548 DM LOW
WAS CENTERED OVER SWRN OREGON. MODERATE TO STRONG GENERALLY SWLY
FLOW PREVAILED OVER SE ARIZONA.
BASED ON SATELLITE IMAGERY AND THE 12/12Z NAM...GRIDDED DATA SKY
VALUES WERE INCREASED TO REPRESENT INCREASED CLOUDINESS VERSUS THE
PREVIOUS FORECAST. THE 12/12Z NAM LIMITED MEASURABLE PRECIP TO THE
WHITE MOUNTAINS TONIGHT. HOWEVER...THE 12/14Z RUC HRRR WAS FURTHER
WEST WITH THE POTENTIAL FOR MEASURABLE PRECIP VERSUS THE NAM...AND
YIELDED SCATTERED COVERAGE ACROSS GREENLEE/GRAHAM/COCHISE COUNTIES
THIS EVENING. THE INHERITED OFFICIAL FORECAST APPEARS TO BE A GOOD
COMPROMISE BETWEEN THESE SOLUTIONS.
THUS...THERE IS A SLIGHT CHANCE OF SHOWERS/TSTMS THIS AFTERNOON
ACROSS THE WHITE MOUNTAINS WITH DRY CONDITIONS ELSEWHERE. A SLIGHT
CHANCE OF SHOWERS/TSTMS EXISTS TONIGHT ACROSS ERN SECTIONS WITH DRY
CONDITIONS CONTINUING ELSEWHERE. A FEW LINGERING SHOWERS MAY OCCUR
WED MORNING NEAR THE NEW MEXICO BORDER...THEN DRY CONDITIONS WILL
PREVAIL AREA WIDE INTO THUR AFTERNOON. HIGH TEMPS THIS AFTERNOON
WILL GENERALLY BE A FEW DEGS COOLER VERSUS MON.
&&
.AVIATION...VALID THRU 13/18Z.
EXPECT ISOLATED -SHRA/-TSRA EAST OF KTUS TO THE NEW MEXICO BORDER
INTO WEDNESDAY MORNING. OTHERWISE...INCREASING MAINLY MID AND HIGH-
LEVEL MOISTURE THIS MORNING WILL PRODUCE BROKEN TO OVERCAST CLOUD
DECKS MAINLY AT 10-15K FT AGL THIS AFTERNOON INTO WEDNESDAY MORNING.
SURFACE WIND THIS AFTERNOON AND EARLY THIS EVENING WILL BE SLY/SWLY
AT 12-20 KTS WITH GUSTS OF 20-30 KTS. SURFACE WIND WILL THEN
DIMINISH TO GENERALLY LESS THAN 10 KTS 02Z-04Z WEDNESDAY AND
CONTINUE INTO WEDNESDAY MORNING. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...THERE IS A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS EAST OF TUCSON INTO EARLY WEDNESDAY. OTHERWISE...DRY
CONDITIONS WILL PREVAIL THROUGH THURSDAY. EXPECT OCCASIONALLY GUSTY
WINDS DURING THE AFTERNOON HOURS INTO WEDNESDAY. A STRONG PACIFIC
LOW PRESSURE SYSTEM WILL APPROACH CALIFORNIA THURSDAY. THIS SYSTEM
WILL PRODUCE STRONG SOUTHWEST WINDS WITH THE POTENTIAL FOR
BORDERLINE RED FLAG CONDITIONS IN ONLY A FEW PLACES. AS THE STORM
MOVES CLOSER ON FRIDAY...WINDS WILL INCREASE FURTHER. HOWEVER...
HUMIDITY LEVELS WILL BE HIGHER WITH LOWER TEMPERATURES AND A CHANCE
FOR SHOWERS AND/OR THUNDERSTORMS. THE SOUTHERN PORTION OF THIS
SYSTEM WILL MOVE ACROSS ARIZONA SATURDAY MAINTAINING A THREAT OF
SHOWERS AND THUNDERSTORMS. DAYTIME TEMPERATURES WILL BE 10-15
DEGREES COOLER THAN NORMAL SATURDAY...THEN DRIER AND SOMEWHAT WARMER
CONDITIONS WILL OCCUR SUNDAY AND MONDAY.
&&
.PREV DISCUSSION...EXPECT A BRIEF RESPITE FROM THE SHOWERS FROM LATE
WEDNESDAY THROUGH LATE THURSDAY BEFORE A MUCH STRONGER PACIFIC
SYSTEM WILL BEGIN TO AFFECT THE REGION LATE THURSDAY EVENING AND
ESPECIALLY OVERNIGHT INTO THE EARLY MORNING HOURS ON FRIDAY AS AN
UPPER LOW WILL BE CENTERED OVER THE GREAT BASIN AT THAT TIME.
ISOLATED TO SCATTERED SHOWERS WILL AFFECT MOSTLY THE HIGHER TERRAIN
THURSDAY NIGHT INTO EARLY FRIDAY. BY FRIDAY AFTERNOON EXPECT
ISOLATED SHOWERS AND THUNDERSTORMS AREA-WIDE WITH SCATTERED ACTIVITY
OVER PARTS OF GRAHAM AND GREENLEE COUNTIES. THIS WILL CONTINUE INTO
FRIDAY NIGHT AND EARLY SATURDAY. MODELS STILL AT ODDS WITH EACH
OTHER ON BOTH TIMING AND POP VALUES. LATEST MOS GUIDANCE HAS FLIP-
FLOPPED FROM THIS TIME YESTERDAY...WITH THE GFS POPS VALUES RANGING
FROM SINGLE DIGITS TO SLIGHT CHANCES ON FRIDAY...THEN IN THE SOLID
CHANCE CATEGORY FOR SATURDAY. MEANWHILE...THE ECMWF MOS NUMBERS FOR
POP REFLECT SLIGHT CHANCE TO LOW END CHANCE FOR FRIDAY AND SIMILAR
FOR SATURDAY. GIVEN THIS CONTINUED UNCERTAINTY...OPTED TO ONLY MAKE
MINOR ADJUSTMENTS TO THE FORECAST AND TO BLEND WITH SURROUNDING
OFFICES.
BY SATURDAY THE UPPER LOW WILL HAVE LIFTED TO THE NORTHEAST INTO THE
NORTHERN ROCKIES...MORE SPECIFICALLY OVER SOUTHEASTERN IDAHO AND
CENTRAL WYOMING. THE TAIL END OF THIS SYSTEM WILL EXTEND ACROSS NEW
MEXICO AND INTO SOUTHEAST ARIZONA AND NORTHERN SONORA. BY THAT TIME
THE BULK OF THE MOISTURE WITH THIS SYSTEM WILL BE TO OUR NORTH...SO
ONLY EXPECTING A SLIGHT CHANCE OF MOUNTAIN SHOWERS AND/OR
THUNDERSTORMS WITH A SLIGHTLY BETTER THREAT FOR PARTS OF GRAHAM AND
GREENLEE COUNTIES.
BY EARLY SUNDAY THE LOW WILL BE OVER THE NORTHERN ROCKIES/PLAINS
STATES WITH WEAK RIDGING BUILDING IN BEHIND THE SYSTEM AND A RETURN
TO DRY WEATHER THROUGH THE REMAINDER OF THE FORECAST PERIOD...ALONG
WITH WARMING TEMPERATURES INTO EARLY NEXT WEEK.
FOR TUCSON...HIGH TEMPERATURES WILL GENERALLY RANGE FROM 2 TO 4 DEGS
BELOW NORMAL TODAY THROUGH THURSDAY...THEN 12 TO 16 DEGS BELOW
NORMAL FOR FRIDAY AND SATURDAY. THEREAFTER...AROUND 8 TO 10 DEGS
BELOW NORMAL FOR SUNDAY AND 3 TO 5 DEGS BELOW NORMAL FOR MONDAY. LOW
TEMPS WILL BE NEAR NORMAL WEDNESDAY THROUGH FRIDAY MORNINGS...THEN 6
TO 8 DEGS BELOW NORMAL FOR THE WEEKEND AND 2 TO 4 DEGS BELOW NORMAL
FOR EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRANCIS
PREVIOUS DISCUSSION...MOLLERE
AVIATION/FIRE WEATHER...HUMPHREYS
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
256 PM MDT TUE MAY 12 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 256 PM MDT TUE MAY 12 2015
AIRMASS IS BECOMING UNSTABLE ALONG THE FRONT RANGE AND NEAR BY
EASTERN PLAINS WHERE CAPES ARE UP TO 1000 J/KG. SHOWERS AND STORMS
HAVE BEEN SLOW TO FORM OVER THE HIGHER TERRAIN WHERE DEW POINTS
ARE IN THE 20S. THE HRRR AND RAP CONTINUE TO SHOW ISOLATED TO
SCATTERED CONVECTION LATER THIS AFTERNOON. AS THESE STORMS MOVE
OFF THE HIGHER TERRAIN...THEY WILL ENCOUNTER GREATER MOISTURE AND
INSTABILITY. EXPECT THE STORMS TO BE CAPABLE OF PRODUCE BRIEF
HEAVY...GUSTY OUTFLOW WINDS TO 40 MPH AND SMALL HAIL. WILL KEEP
THE ISOLATED TO SCATTERED POPS IN THE FORECAST FOR THE EVENING
HOURS.
A SHORT WAVE TROUGH CURRENTLY OVER BAJA CALIFORNIA WILL LIFT
NORTHEAST ACROSS THE REGION ON WEDNESDAY. EXPECT MOSTLY CLOUDY
SKIES AHEAD OF THIS FOR WEDNESDAY. BEST LIFT AND MOISTURE WILL
REMAIN TO THE SOUTH AND EAST OF THE AREA. HOWEVER SHOULD BE ENOUGH
MOISTURE AND LIFT WITH FOR SCATTERED SHOWERS AND THUNDERSTORMS.
CAPES WILL BE LESS THAN 500 J/KG...SO EXPECT STORMS TO STAY BELOW
SEVERE THRESHOLDS. LOWERED HIGH TEMPERATURES A FEW DEGREES DUE TO
THE CLOUDINESS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 256 PM MDT TUE MAY 12 2015
WEAK QG ASCENT SHOULD STILL BE IMPACTING MUCH OF THE CWA AT 00Z
THURSDAY AND WILL GRADUALLY TRANSITION TO SUBSIDENCE OVERNIGHT AS
UPPER LEVEL RIDGING MOVES IN. THIS WILL ALLOW THURSDAY TO HAVE
LOWER POPS ALTHOUGH PROBABLY NOT COMPLETELY ZERO...ESPECIALLY IN
THE MOUNTAINS.
THE NEXT WAVE AND QG ASCENT BEGINS IN THE MORE SOUTHERLY FLOW ON
FRIDAY WHICH SHOULD ALLOW FOR A BIT MORE SHOWER COVERAGE IN THE
MOUNTAINS DURING THE NORMAL DIURNAL TIMES BUT STILL NOTHING
TREMENDOUS. SHOWER ACTIVITY ON THE PLAINS WILL BE BATTLING A LACK
OF UPSLOPE SO PRECIPITATION THERE WILL BE SPOTTY AT BEST.
THE SYSTEM FOR SATURDAY IS LOOKING A BIT LESS PROMISING THAN
EARLIER. SOME SPREAD IN THE SOLUTIONS OF THE UPPER LOW POSITION BUT
THE MODELS ARE SHOWING SOME QG ASCENT OVER THE CWA ALONG WITH LIGHT
QPF. AGAIN...NOTHING TERRIBLY NOTEWORTHY.
STRONG QG SUBSIDENCE IS FORECAST ON SUNDAY ALONG WITH A PUSH OF LOW
LEVEL HIGH PRESSURE FROM THE NORTH WHICH MAY PUT A SIGNIFICANT
DAMPER ON THE PRECIPITATION THREAT SUNDAY. THE UPPER RIDGE MOVES
EAST OF COLORADO ON MONDAY FOR A SLIGHT INCREASE IN CONVECTIVE
ACTIVITY BY TUESDAY.
ALL IN ALL AT THIS TIME IT APPEARS THAT THERE IS A RATHER LOW RISK
OF HEAVY PRECIPITATION THAT COULD WORSEN THE FLOODING SITUATION.
MOREOVER...TEMPERATURES WILL REMAIN ON THE COOL SIDE WHICH WILL
LESSEN THE MELTING OF THE SNOWPACK.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON)
ISSUED AT 256 PM MDT TUE MAY 12 2015
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH WEDNESDAY. ISOLATED
TO SCATTERED THUNDERSTORMS ARE EXPECTED 22-03Z TODAY. ANOTHER
ROUND OF AFTERNOON THUNDERSTORMS ARE EXPECTED FOR
WEDNESDAY...LIKELY A LITTLE EARLIER. THE STORMS WILL BE CAPABLE OF
PRODUCING WIND GUSTS TO 35 KNOTS...BRIEF HEAVY RAIN AND SMALL
HAIL. OUTSIDE OF OUTFLOW WINDS FROM THUNDERSTORMS...WINDS WILL BE
SOUTHERLY AT KAPA AND KDEN. THROUGH WEDNESDAY. A WEAK DENVER
CYCLONE MAY CAUSE WINDS TO TURN NORTHWESTERLY AFTER 12Z WEDNESDAY
AT KDEN.
&&
.HYDROLOGY...
ISSUED AT 256 PM MDT TUE MAY 12 2015
THE SOUTH PLATTE RIVER IS CRESTING OVER WESTERN MORGAN COUNTY. THE
CREST IS EXPECTED TO MOVE DOWN STREAM THROUGH MORGAN COUNTY THE NEXT
24 HOURS. FORECAST CRESTS HAVE BEEN SLIGHTLY LOWERED THIS MORNING
ALONG THE SOUTH PLATTE RIVER.
ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED THIS EVENING AND
WEDNESDAY AFTERNOON AND EVENING. BRIEF HEAVY RAIN IS POSSIBLE WITH
THE THUNDERSTORMS. BEST CHANCE FOR HEAVY RAIN WILL BE WEDNESDAY
AFTERNOON WHERE UP TO AN INCH WILL BE POSSIBLE UNDER THE STRONGEST
STORMS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MEIER
LONG TERM...ET
AVIATION...MEIER
HYDROLOGY...MEIER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1040 AM MDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 1040 AM MDT TUE MAY 12 2015
THE LATEST HRRR ...ARW...NMM AND NAM SHOW THE BEST CHANCE FOR
SHOWERS AND STORMS ALONG THE FRONT RANGE FROM DENVER TO GREELEY TO
FORT MORGAN. WILL INCREASE POPS INTO THE SCATTERED RANGE FOR THIS.
WITH THE DRY LOW LEVELS...THE CONVECTION WILL PRODUCE GUSTY
OUTFLOW WINDS. ANY HEAVY RAIN WILL BE LOCALIZED AND LIKELY LESS
THAN A HALF INCH. NO OTHER CHANGES TO THE FORECAST ARE PLANNED.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 419 AM MDT TUE MAY 12 2015
UPPER RIDGE IS SHIFTING EAST OF COLORADO WITH SURFACE HIGH
PRESSURE ON THE PLAINS. HIGH LEVEL MOISTURE MOVING ACROSS IN
SOUTHWEST FLOW ALOFT...WHILE LOW LEVELS REMAIN DRY. LOOKING LIKE
THERE WILL BE SOME DECREASE IN THE HIGH LEVEL MOISTURE LATER
TODAY...BUT CONVECTION WILL LIKELY OFFSET THAT. STICKING WITH THE
FORECAST OF SCATTERED CONVECTION OVER THE MOUNTAINS...WITH
ISOLATED STORMS WORKING ONTO THE PLAINS LATE IN THE DAY. WITH
CAPES EXPECTED TO BE 500-1000 J/KG OVER THE MOUNTAINS AND DRY LOW
LEVELS...SOME OF THE STORMS WILL LIKELY PRODUCE GUSTY WINDS BUT
WITH LIMITED FLOW ALOFT NOT TOO MUCH OF A SEVERE THREAT. THE
PLAINS WILL BE WEAKLY CAPPED MOST OF THE DAY...MOST LIKELY
CONVECTION WILL BE ON OUTFLOWS FROM THE MOUNTAIN CONVECTION.
ANY SIGNIFICANT RAIN SHOULD BE ON A SMALL SCALE SO NOT MUCH IMPACT
TO CURRENT RIVER CONDITIONS.
I ONLY MADE MINOR ADJUSTMENTS TO THE FORECAST...INCREASING CLOUDS
THIS MORNING AND ADDING A BIT MORE WIND ON THE PLAINS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 419 AM MDT TUE MAY 12 2015
STARTING WEDNESDAY MORNING A SHORTWAVE TROUGH WILL MOVE NORTH OUT OF
THE DESERT SOUTHWEST ACROSS EASTERN COLORADO. MOISTURE AND
PRECIPITATION WILL MOVE INTO THE MOUNTAINS FIRST WITH A LEE SIDE
TROUGH DOMINATING THE NE COLORADO PLAINS. THROUGH THE DAY WEDNESDAY
WITH THE INCREASE OF INSTABILITY FROM HEATING AND MOISTURE AFTERNOON
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE. PERIODS OF HEAVIER RAIN
WILL BE POSSIBLE UNDER THE STRONGER STORMS...ESPECIALLY OVER THE
EASTERN PLAINS. SNOW IN THE MOUNTAINS ABOVE 10000FT WILL BE POSSIBLE
WITH LIGHT ACCUMULATIONS ON WEDNESDAY. TEMPERATURES ON WEDNESDAY
WILL BE SLIGHTLY COOLER WITH HIGHS IN THE UPPER 60S.
THE TROUGH WILL CONTINUE TO MOVE NORTH ON THURSDAY WITH SURFACE HIGH
PRESSURE PUSHING INTO WESTERN COLORADO AND A LEE TROUGH FORMING OVER
EASTERN COLORADO. UPPER LEVEL RIDGING THURSDAY WILL HELP DRY OUT
CONDITIONS BRINGING ANOTHER SHORT REPRIEVE FROM RAIN. TEMPERATURES
THURSDAY WILL BOUNCE BACK TO SEASONAL NORMALS WITH HIGHS REACHING
INTO THE MID 70S.
MODELS ARE CURRENTLY IN DECENT AGREEMENT REGARDING THE NEXT SYSTEM
FORMING OFF THE COAST OF CALIFORNIA BY THURSDAY EVENING. UPPER LEVEL
FLOW WILL BE STRONG FROM THE SOUTHWEST. SEVERAL EMBEDDED
DISTURBANCES WILL KEEP A STEADY STREAM OF MOISTURE MOVING INTO
COLORADO THAT WILL HELP BRING A SLIGHT CHANCE OF AFTERNOON SHOWERS
AND THUNDERSTORMS TO THE NE REGION. FOR FRIDAY...TEMPERATURES REACH
INTO THE UPPER 70S WITH INCREASED CAPE VALUES ALONG THE KS BORDER
ALONG WITH A SHARP DRY LINE THAT COULD AID IN STRONG THUNDERSTORM
DEVELOPMENT FOR FRIDAY AFTERNOON AND EVENING.
ON SATURDAY AND SUNDAY THE UPPER LEVEL LOW WILL CONTINUE TO MAKE ITS
EASTWARD PROGRESSION WITH STEADY MOISTURE OVER THE MOUNTAINS AND
PLAINS THROUGH THE WEEKEND. TEMPERATURES WILL DIP BACK TO JUST BELOW
NORMALS WITH HIGHS ONLY GETTING INTO THE MID TO UPPER 60S. THE
SYSTEM LIFTS OUT TO THE NORTHEAST BY MONDAY EVENING BRINGING UPPER
LEVEL RIDGING AND WARMER TEMPERATURES FOR TUESDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1040 AM MDT TUE MAY 12 2015
VFR THROUGH WEDNESDAY. ISOLATED TO SCATTERED THUNDERSTORMS ARE
EXPECTED BETWEEN 21Z AND 03Z WITH THE MAIN THREAT BEING GUSTY
WINDS TO AROUND 30 KNOTS. WINDS AT KAPA WILL MAINLY BE FROM THE
SOUTH...WHILE KDEN WILL BE EAST TO SOUTHEAST. A WEAK DENVER
CYCLONE PRODUCED A LIGHT THIS MORNING AND MAY AGAIN LATE TONIGHT
AND WEDNESDAY MORNING.
&&
.HYDROLOGY...
ISSUED AT 419 AM MDT TUE MAY 12 2015
MAIN CREST ON THE SOUTH PLATTE IS MOVING INTO MORGAN COUNTY...WITH
A SERIES OF SMALLER RISES PRECEDING IT. LITTLE CHANGE TO THE RIVER
FORECAST AS MODERATE TO MAJOR FLOODING IS EXPECTED DOWNSTREAM TO
STERLING THROUGH FRIDAY...AND MINOR TO MODERATE FLOODING BETWEEN
STERLING AND JULESBURG THIS WEEKEND.
WE WILL NEED TO WATCH ANY ADDITIONAL RAINFALL...THE FIRST
OPPORTUNITY IS WEDNESDAY AFTERNOON AND EVENING WHICH LOOKS
LIGHT OVERALL BUT THERE COULD BE SOME LOCALIZED HEAVIER
RAIN OF UP TO AN INCH. THAT WOULD EXACERBATE LOCAL PROBLEMS...
BUT PROBABLY NOT MUCH INFLUENCE ON THE PLATTE FLOODING. THERE MAY
BE BETTER COVERAGE OF THUNDERSTORMS WITH ADDITIONAL RAINFALL OVER
THE WEEKEND...NOT MUCH INDICATION OF ANY HEAVY RAINFALL HOWEVER.
CLOSER TO THE FRONT RANGE STREAMS WILL REMAIN HIGH INDEFINITELY WITH
SATURATED SOILS AND INCREASING SNOWMELT WITH THE WARMER TEMPERATURES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MEIER
SHORT TERM...GIMMESTAD
LONG TERM...BOWEN
AVIATION...MEIER
HYDROLOGY...GIMMESTAD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1222 PM CDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 943 AM CDT TUE MAY 12 2015
MAIN STRATOCUMULUS SHIELD BASICALLY MADE IT DOWN TO THE I-74
CORRIDOR WITH SOME SCATTERED CLOUDS AS FAR SOUTH AS MATTOON AND
LAWRENCEVILLE...BUT THESE SHOULD CONTINUE TO PULL BACK NORTHWARD
THROUGH MIDDAY. HOWEVER...LATEST RAP GUIDANCE SUGGESTS THE CLOUDS
HOLDING ON A BIT LONGER AROUND CHAMPAIGN AND DANVILLE. CURRENTLY
SEEING SOME WIND GUSTS OF 25-30 MPH...WHICH SHOULD CONTINUE INTO
MID AFTERNOON. TEMPERATURES CURRENTLY ON TRACK AND ONLY REQUIRED
SOME MINOR TWEAKS. UPDATES TO THE ZONES/GRIDS WERE MAINLY DONE FOR
THE SKY COVER AND WIND TRENDS.
&&
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT TUE MAY 12 2015
07Z/2AM SURFACE ANALYSIS SHOWS 1001MB LOW OVER THE NORTHERN GREAT
LAKES WHILE A 1025MB HIGH BUILDS INTO THE CENTRAL PLAINS. PRESSURE
GRADIENT BETWEEN THESE TWO FEATURES WILL REMAIN TIGHT ENOUGH TO
PRODUCE BRISK WESTERLY WINDS ACROSS CENTRAL ILLINOIS TODAY.
SUSTAINED WINDS WILL GENERALLY BE IN THE 10 TO 15 MPH RANGE...BUT
GUSTS COULD REACH 25 TO 30 MPH AS MIXING TAKES PLACE LATER THIS
MORNING. LATEST VWP NETWORK SHOWS 925MB WINDS OF 40 TO 45 MPH AND
THINK SOME OF THIS HIGHER MOMENTUM AIR WILL GET MIXED DOWN TO THE
SURFACE ONCE MORNING INVERSION IS BROKEN. PRESSURE GRADIENT WILL
TEND TO RELAX AS THE DAY PROGRESSES...SO GUSTS WILL BEGIN TO SLOWLY
SUBSIDE BY MID-AFTERNOON. LOW CLOUDS CURRENTLY ALONG/NORTH OF A
RUSHVILLE TO BLOOMINGTON LINE WILL LIFT NORTHEASTWARD AND CLEAR OUT
OF THE AREA BY MID-MORNING...FOLLOWED BY MOSTLY SUNNY SKIES ACROSS
THE BOARD FOR THE REMAINDER OF THE DAY. AFTERNOON HIGH TEMPERATURES
WILL BE SEVERAL DEGREES COOLER THAN IN RECENT DAYS...WITH READINGS
ONLY RISING INTO THE LOWER TO MIDDLE 60S.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 329 AM CDT TUE MAY 12 2015
HIGH PRESSURE WILL BUILD EASTWARD INTO THE MIDWEST TONIGHT...WITH
THE RIDGE AXIS EXPECTED TO BE POSITIONED RIGHT OVER ILLINOIS BY 12Z
WED. CLEAR SKIES AND LIGHT WINDS BENEATH THE RIDGE WILL ALLOW
EXCELLENT RADIATIONAL COOLING OF THE DRY AIRMASS TO TAKE
PLACE...RESULTING IN OVERNIGHT LOW TEMPERATURES IN THE LOWER TO
MIDDLE 40S. MAY EVEN SEE A FEW UPPER 30S IN FAVORED LOW-LYING
RURAL AREAS. THE HIGH WILL BEGIN TO SHIFT OFF TO THE EAST ON
WEDNESDAY...HOWEVER LOW-LEVEL FLOW WILL MAINTAIN A DISTINCT
EASTERLY COMPONENT. AS A RESULT...HIGH TEMPERATURES WILL REMAIN ON
THE COOL SIDE IN THE UPPER 60S TO AROUND 70 DEGREES.
UPPER HEIGHTS BEGIN TO RISE SIGNIFICANTLY BY THURSDAY AS DEEP UPPER
LOW OVER THE GULF OF ALASKA DROPS SOUTHEASTWARD AND REACHES THE
CALIFORNIA COAST...RESULTING IN DOWNSTREAM RIDGING ACROSS THE
CENTRAL AND EASTERN CONUS. A WEAK DISTURBANCE NOTED ON LATEST WATER
VAPOR IMAGERY OFF THE COAST OF SOUTHERN CALIFORNIA WILL GET EJECTED
NORTHEASTWARD BY THE DIGGING WEST COAST TROUGH...WITH THIS FEATURE
TRACKING INTO THE GREAT LAKES BY FRIDAY. MODELS ARE IN GOOD
AGREEMENT WITH THE TRACK AND TIMING OF THIS WAVE...WITH SOME MINOR
DISCREPANCIES ON HOW QUICKLY TO SPREAD PRECIP INTO ILLINOIS. GIVEN
INITIALLY VERY DRY AIRMASS IN PLACE BENEATH THE SURFACE
HIGH...PREFER A SLOWER ARRIVAL OF PRECIP. AS A RESULT...HAVE GONE
WITH A DRY FORECAST THROUGH THURSDAY MORNING EAST OF I-55 WITH LOW
CHANCE POPS DELAYED UNTIL AFTERNOON. FURTHER WEST...RAIN CHANCES
WILL INCREASE TO LIKELY ACROSS THE ILLINOIS RIVER VALLEY BY
AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL SPREAD ACROSS
MUCH OF THE AREA THURSDAY NIGHT...WITH THE BEST RAIN CHANCES FOCUSED
NORTH OF THE I-70 CORRIDOR. ONCE THE SHORT-WAVE SHIFTS INTO THE
GREAT LAKES...FORCING FOR ADDITIONAL PRECIP BECOMES MUCH WEAKER
FRIDAY AND SATURDAY. SEVERAL MODELS ARE HINTING THAT ANOTHER
WEAK WAVE EMBEDDED WITHIN THE SOUTHWESTERLY FLOW MAY ENHANCE
SHOWERS ACROSS SOUTHERN ILLINOIS INTO THE OHIO RIVER
VALLEY...HOWEVER VERY LITTLE FOCUS FOR ORGANIZED CONVECTION EXISTS
FURTHER NORTH ACROSS THE REMAINDER OF THE AREA. AS A
RESULT...WILL ONLY CARRY LOW CHANCE POPS THROUGH THE PERIOD.
DEEP UPPER LOW OVER CALIFORNIA WILL GRADUALLY EJECT NORTHEASTWARD
LATE IN THE WEEKEND. MODELS ARE IN GOOD AGREEMENT WITH THIS PROCESS
THROUGH 144 HOURS...THEN SOLUTIONS BEGIN TO DIVERGE AFTER THAT.
BOTH THE GFS AND ECMWF SHOW THE LOW TRACKING INTO THE DAKOTAS BY
SUNDAY EVENING...WITH CONVECTION DEVELOPING ALONG A TRAILING COLD
FRONT ACROSS THE PLAINS. THE ECMWF THEN BECOMES MORE PROGRESSIVE
WITH THE WAVE...AS IT OPENS UP AND PUSHES EASTWARD INTO THE NORTHERN
GREAT LAKES BY MONDAY. MEANWHILE...THE GFS KEEPS THE LOW CLOSED
LONGER AND IS THUS SLOWER WITH ITS EASTWARD TRACK. THIS MAKES A BIG
DIFFERENCE WITH TIMING OF ASSOCIATED COLD FRONT...AS GFS LINGERS
THIS BOUNDARY AND RAIN CHANCES UNTIL TUESDAY. SINCE OVERALL
SYNOPTIC PATTERN HAS BEEN PROGRESSIVE OVER THE PAST WEEK AND THE GEM
SUPPORTS THE ECMWF...WILL BE GOING WITH THE FASTER ECMWF/GEM
SOLUTION IN THE EXTENDED. AS A RESULT...WILL BRING LIKELY POPS INTO
THE FAR WESTERN CWA SUNDAY AFTERNOON...THEN FURTHER EAST ACROSS THE
REMAINDER OF THE AREA SUNDAY NIGHT. WILL THEN BEGIN TO SHIFT THE
RAIN CHANCES OUT OF THE PICTURE ON MONDAY...WITH DRY WEATHER
RETURNING MONDAY NIGHT AND TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1219 PM CDT TUE MAY 12 2015
THICKER STRATOCUMULUS AROUND 3500 FEET CONTINUES TO BREAK UP AND
WILL BE MOST PROMINENT AT KCMI/KDEC FOR A COUPLE MORE HOURS.
OTHERWISE...GENERAL TREND WILL BE VFR WITH SOME INCREASE IN HIGH
CLOUDS LATER THIS AFTERNOON. GUSTY WEST/NORTHWEST WINDS AROUND 25
KNOTS SHOULD BE SETTLING DOWN AFTER ABOUT 23Z...AND WILL GRADUALLY
TURN MORE THE NORTH/NORTHEAST OVERNIGHT AS AN AREA OF HIGH
PRESSURE MOVES THROUGH THE MIDWEST. AS THE HIGH MOVES FURTHER EAST
WEDNESDAY MORNING...WINDS WILL BECOME MORE EASTERLY AND INCREASE
TO AROUND 10 KNOTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS CARIBOU ME
614 PM EDT TUE MAY 12 2015
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE ACROSS QUEBEC TONIGHT BRINGING A COLD
FRONT INTO THE AREA. THE COLD FRONT WILL PUSH THROUGH THE REGION
WEDNESDAY MORNING AND OFF THE COAST. HIGH PRESSURE WILL BUILD
TOWARD THE REGION LATER WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
614 PM UPDATE...A LINE OF SHOWERS MOVING OUT OF CENTRAL MAINE
WILL QUICKLY MOVE TO THE NEW BRUNSWICK BORDER OVER THE NEXT 1 TO 2
HOURS. CALLS TO WEATHER SPOTTERS INDICATE SOME HEAVY
DOWNPOURS...BUT LITTLE WIND. THUS FAR ONLY SOME IN CLOUD LIGHTNING
DETECTED. ONCE THIS LINE MOVES OUT OF THE AREA ATTENTION TURNS TO
SHOWERS AND THUNDERSTORMS IN QUEBEC THAT WILL DRIFT INTO FAR
NORTHERN MAINE OVER THE NEXT FEW HOURS. MAIN ADJUSTMENT WAS TO THE
POPS OVER THE NEXT COUPLE OF HOURS TO ACCOUNT FOR THE LINE OF
SHOWERS MOVING OUT OF CENTRAL MAINE.
PREVIOUS DISCUSSION...
ISOLATED THUNDERSTORMS POSSIBLE W/SOME DECENT WIND GUSTS.
LOW CLOUDS SLOWLY ERODING ACROSS THE EASTERN AREAS THIS AFTERNOON
KEEPING THE LLVLS STABLE WHILE WESTERN AND SW AREAS HAVE BROKEN
OUT W/SUNSHINE AND HENCE TEMPS WARMING. THIS HAS ALLOWED FOR
THINGS TO DESTABILIZE MORE. 18Z SURFACE ANALYSIS HAD THE WARM
FRONT/PRE-FRONTAL BOUNDARY SLOWLY LIFT INTO WESTERN MAINE W/THE
COLD FRONT STILL BACK WESTERN QUEBEC. STEADY RAIN HAS ENDED OR
MOVED E W/A MORE SHOWERY NATURE OF THE PRECIP SETTING UP. LATEST
NAM AND RAP SOUNDINGS SUPPORT DECENT SB/MU CAPE OF 700+ JOULES
W/LIS DOWN TO -2 IN THESE AREAS. GOOD SHEAR IN THE 0-6KM LAYER
AROUND 35 KTS. SPC MESO ANALYSIS SHOWED DECENT MID LEVEL LAPSE
RATES OF 6.5 C/KM HELPING W/INSTABILITY. KEPT ENHANCED WORDING FOR
FOR NOW FOR GUSTY WINDS AND HEAVY RAINFALL POTENTIAL. THINGS WILL
WIND DOWN ACROSS THE W AND SW THIS EVENING AND THEN SHIFT ACROSS
THE NORTHERN AREAS AS THE COLD FRONT APCHS W/LOW PRES PASSING
ACROSS SOUTHERN QUEBEC. 12Z UA SHOWED DECENT MID LEVEL COOLING AND
STRONG JET FROM 700-500MBS OF AROUND 65 KTS. THOSE STRONGER WINDS
COULD GET MIXED DOWN SOME TO THE SFC W/ANY ELEVATED CONVECTION.
LEANED W/ENHANCED WORDING FOR THE GUSTY WINDS IN ANY STORMS
THROUGH MIDNIGHT. HEAVY RAINFALL POTENTIAL IS POSSIBLE AS WELL
W/THE STORMS MOVING PARALLEL TO THE UPPER FLOW.
CONVECTIVE POTENTIAL WINDS DOWN AFTER MIDNIGHT W/JUST SHOWERS AND
THE BULK OF THE ACTION ACROSS THE NORTHERN TIER. COOLING TO TAKE
AFFECT AS NW WIND TAKE OVER THROUGH THE COLUMN. WE ARE TALKING
UPPER 30S BACK ACROSS THE WNW BY EARLY WEDNESDAY MORNING W/40S
ELSEWHERE. THIS COLD AIR CAN BE SEEN ALREADY SHOWING UP IN NW
QUEBEC. WEDNESDAY WILL BE MUCH COOLER W/THE UPPER TROF ACROSS THE
REGION W/UPPER 50S NORTH AND WEST WHILE CENTRAL AND DOWNEAST WILL
SEE AROUND 60F OR SO DUE TO SOME DOWNSLOPING. IT WILL BE BREEZY
W/NW WINDS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
STRONG HIGH PRESSURE WILL BUILD IN FROM THE WEST AND WEDNESDAY
NIGHT AND CREST OVER THE REGION EARLY FRIDAY KEEPING THE STATE
RELATIVELY DRY. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND
SKY CONDITIONS. FOR WINDS HAVE USED THE MOSG25. THE SUPER BLEND
WAS USED TO POPULATE THE TEMPERATURE AND DEW POINT GRIDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
STRONG HIGH PRESSURE WILL MOVE OFF THE EAST COAST LATE FRIDAY.
WEAK LOW PRESSURE WILL PASS TO THE SOUTH OF THE REGION SATURDAY.
HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY. A COLD
FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT AND CROSS THE
REGION TUESDAY. WILL USE THE SUPER BLEND TO POPULATE ALL GRIDS.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: MOSTLY VFR EARLYTHIS EVENING AT THE NORTHERN TERMINALS
WITH CONDITIONS TO DROP BACK TO MVFR AND IFR W/THE APCHG COLD
FRONT TONIGHT. IMPROVEMENT TO MVFR BY MID MORNING AND VFR BY LATE
IN THE DAY. KBGR AND KBHB WILL SEE VFR THROUGH TUESDAY. THERE IS A
RISK OF AN ISOLATED TSTM THROUGH THIS EVENING W/GUSTY WINDS.
SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM: SCA FOR HAZARDOUS SEAS IS IN EFFECT INCLUDING THE
INTRA-COASTAL ZONE. A SWELL BEING GENERATED FROM LEFTOVER TD ANA
IS FORECAST LIFT ACROSS THE WATERS LATER THIS EVENING INTO
WEDNESDAY. DECIDED ON HEIGHTS UP TO A RANGE OF 6-7 FT W/THE
HIGHEST WAVES OVER THE OUTER WATERS. THE INTRA-COASTAL ZONE WILL
MOST LIKELY SEE WAVES OF AROUND 5FT W/A 8-9 SECOND PERIOD. FOG
WILL BE A NUISANCE FOR NAVIGATION THROUGH TONIGHT.
FOR THE WINDS, DECIDED ATTM TO KEEP WIND GUSTS IN THE LOWER 2OS
ON WEDNESDAY W/THE NW FLOW. THE OUTER WATERS COULD SEE GUSTS HIT
25 KT FOR A BRIEF PERIOD.
SHORT TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR SUSTAINED WINDS
WEDNESDAY NIGHT THROUGH FRIDAY THEN TRANSITION TO THE SUPER BLEND
WINDS. FOR WAVES: PRIMARY WAVE SYSTEM WILL BE LONG PERIOD SWELL
FROM REMNANTS OF TROPICAL DEPRESSION ANA. EXPECT 5 FEET/9-10
SECONDS WAVE HEIGHTS WEDNESDAY NIGHT SUBSIDING DURING THE DAY
THURSDAY. WILL CARRY AN SCA EARLY WEDNESDAY EVENING BUT EXPECT
SEAS TO SUBSIDE BELOW SCA LATER AT NIGHT AS THE LONG PERIOD WAVE
SYSTEM SUBSIDES. WILL USE THE NEAR SHORE WAVE MODEL THROUGH FRIDAY
THEN TRANSITION TO THE WAVE WATCH III.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT
TO MIDNIGHT EDT WEDNESDAY NIGHT FOR ANZ050>052.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...CB/HEWITT/MIGNONE
MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
354 PM EDT TUE MAY 12 2015
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE ACROSS QUEBEC TONIGHT BRINGING A COLD
FRONT INTO THE AREA. THE COLD FRONT WILL PUSH THROUGH THE REGION
WEDNESDAY MORNING AND OFF THE COAST. HIGH PRESSURE WILL BUILD
TOWARD THE REGION LATER WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
ISOLATED THUNDERSTORMS POSSIBLE W/SOME DECENT WIND GUSTS.
LOW CLOUDS SLOWLY ERODING ACROSS THE EASTERN AREAS THIS AFTERNOON
KEEPING THE LLVLS STABLE WHILE WESTERN AND SW AREAS HAVE BROKEN
OUT W/SUNSHINE AND HENCE TEMPS WARMING. THIS HAS ALLOWED FOR
THINGS TO DESTABILIZE MORE. 18Z SURFACE ANALYSIS HAD THE WARM
FRONT/PRE-FRONTAL BOUNDARY SLOWLY LIFT INTO WESTERN MAINE W/THE
COLD FRONT STILL BACK WESTERN QUEBEC. STEADY RAIN HAS ENDED OR
MOVED E W/A MORE SHOWERY NATURE OF THE PRECIP SETTING UP. LATEST
NAM AND RAP SOUNDINGS SUPPORT DECENT SB/MU CAPE OF 700+ JOULES
W/LIS DOWN TO -2 IN THESE AREAS. GOOD SHEAR IN THE 0-6KM LAYER
AROUND 35 KTS. SPC MESO ANALYSIS SHOWED DECENT MID LEVEL LAPSE
RATES OF 6.5 C/KM HELPING W/INSTABILITY. KEPT ENHANCED WORDING FOR
FOR NOW FOR GUSTY WINDS AND HEAVY RAINFALL POTENTIAL. THINGS WILL
WIND DOWN ACROSS THE W AND SW THIS EVENING AND THEN SHIFT ACROSS
THE NORTHERN AREAS AS THE COLD FRONT APCHS W/LOW PRES PASSING
ACROSS SOUTHERN QUEBEC. 12Z UA SHOWED DECENT MID LEVEL COOLING AND
STRONG JET FROM 700-500MBS OF AROUND 65 KTS. THOSE STRONGER WINDS
COULD GET MIXED DOWN SOME TO THE SFC W/ANY ELEVATED CONVECTION.
LEANED W/ENHANCED WORDING FOR THE GUSTY WINDS IN ANY STORMS
THROUGH MIDNIGHT. HEAVY RAINFALL POTENTIAL IS POSSIBLE AS WELL
W/THE STORMS MOVING PARALLEL TO THE UPPER FLOW.
CONVECTIVE POTENTIAL WINDS DOWN AFTER MIDNIGHT W/JUST SHOWERS AND
THE BULK OF THE ACTION ACROSS THE NORTHERN TIER. COOLING TO TAKE
AFFECT AS NW WIND TAKE OVER THROUGH THE COLUMN. WE ARE TALKING
UPPER 30S BACK ACROSS THE WNW BY EARLY WEDNESDAY MORNING W/40S
ELSEWHERE. THIS COLD AIR CAN BE SEEN ALREADY SHOWING UP IN NW
QUEBEC. WEDNESDAY WILL BE MUCH COOLER W/THE UPPER TROF ACROSS THE
REGION W/UPPER 50S NORTH AND WEST WHILE CENTRAL AND DOWNEAST WILL
SEE AROUND 60F OR SO DUE TO SOME DOWNSLOPING. IT WILL BE BREEZY
W/NW WINDS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
STRONG HIGH PRESSURE WILL BUILD IN FROM THE WEST AND WEDNESDAY
NIGHT AND CREST OVER THE REGION EARLY FRIDAY KEEPING THE STATE
RELATIVELY DRY. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND
SKY CONDITIONS. FOR WINDS HAVE USED THE MOSG25. THE SUPER BLEND
WAS USED TO POPULATE THE TEMPERATURE AND DEW POINT GRIDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
STRONG HIGH PRESSURE WILL MOVE OFF THE EAST COAST LATE FRIDAY.
WEAK LOW PRESSURE WILL PASS TO THE SOUTH OF THE REGION SATURDAY.
HIGH PRESSURE WILL THEN BUILD IN FROM THE NORTH MONDAY. A COLD
FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT AND CROSS THE
REGION TUESDAY. WILL USE THE SUPER BLEND TO POPULATE ALL GRIDS.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: IFR NORTHERN TERMINALS TO GO VFR THIS EVENING AND THEN
DROP BACK TO MVFR AND IFR W/THE APCHG COLD FRONT TONIGHT.
IMPROVEMENT TO MVFR BY MID MORNING AND VFR BY LATE IN THE DAY. KBGR
AND KBHB WILL SEE VFR THROUGH TUESDAY. THERE IS A RISK OF AN
ISOLATED TSTM THROUGH THIS EVENING W/GUSTY WINDS.
SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM: SCA FOR HAZARDOUS SEAS IS IN EFFECT INCLUDING THE
INTRA-COASTAL ZONE. A SWELL BEING GENERATED FROM LEFTOVER TD ANA
IS FORECAST LIFT ACROSS THE WATERS LATER THIS EVENING INTO
WEDNESDAY. DECIDED ON HEIGHTS UP TO A RANGE OF 6-7 FT W/THE
HIGHEST WAVES OVER THE OUTER WATERS. THE INTRA-COASTAL ZONE WILL
MOST LIKELY SEE WAVES OF AROUND 5FT W/A 8-9 SECOND PERIOD. FOG
WILL BE A NUISANCE FOR NAVIGATION THROUGH TONIGHT.
FOR THE WINDS, DECIDED ATTM TO KEEP WIND GUSTS IN THE LOWER 2OS
ON WEDNESDAY W/THE NW FLOW. THE OUTER WATERS COULD SEE GUSTS HIT
25 KT FOR A BRIEF PERIOD.
SHORT TERM: HAVE BLENDED THE NAM12 AND GFS40 FOR SUSTAINED WINDS
WEDNESDAY NIGHT THROUGH FRIDAY THEN TRANSITION TO THE SUPER BLEND
WINDS. FOR WAVES: PRIMARY WAVE SYSTEM WILL BE LONG PERIOD SWELL
FROM REMNANTS OF TROPICAL DEPRESSION ANA. EXPECT 5 FEET/9-10
SECONDS WAVE HEIGHTS WEDNESDAY NIGHT SUBSIDING DURING THE DAY
THURSDAY. WILL CARRY AN SCA EARLY WEDNESDAY EVENING BUT EXPECT
SEAS TO SUBSIDE BELOW SCA LATER AT NIGHT AS THE LONG PERIOD WAVE
SYSTEM SUBSIDES. WILL USE THE NEAR SHORE WAVE MODEL THROUGH FRIDAY
THEN TRANSITION TO THE WAVE WATCH III.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM MIDNIGHT TONIGHT
TO MIDNIGHT EDT WEDNESDAY NIGHT FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...HEWITT/MIGNONE
MARINE...HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1238 PM CDT TUE MAY 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT TUE MAY 12 2015
HIGH PRESSURE CENTERED ACROSS KS MOVES EAST INTO MISSOURI TODAY.
LOW PRESSURE WILL BEGIN TO ORGANIZE ACROSS THE NRN HIGH PLAINS
THIS AFTERNOON. THE MODEL CONSENSUS SHOWS STRONG RETURN FLOW
DEVELOPING THIS AFTERNOON WITH SOUTH WINDS INCREASING TO 20 TO 30
MPH ACROSS WRN NEB. THESE WINDS SHOULD CONTINUE TONIGHT AS THE LOW
LEVEL JET FORMS AND STRENGTHENS TO AROUND 50 KT.
THE TEMPERATURE FORECAST TODAY FOLLOWS THE WARMER SIDE OF THE MODEL
CONSENSUS. SEVERAL MODELS WERE VERY COLD WITH HIGHS IN THE 60S WHILE
THE RAP WAS VERY WARM WITH HIGHS IN THE UPPER 70S. THE FORECAST IS
FOR HIGHS IN THE UPPER 60S TO MID 70S.
LOWS TONIGHT FALL INTO THE UPPER 40S TO AROUND 50. SOUTH WINDS AT 15
TO 20 MPH SHOULD KEEPS LOWS MILD.
LASTLY...THE MODELS SHOW A WEAK DISTURBANCE FIRING THUNDERSTORMS ON
THE LARAMIE AND FRONT RANGES LATE THIS AFTERNOON AROUND 21Z WHICH
CARRY EAST TOWARD WESTERN NEBRASKA. THE BEST GUESS IS FOR ISOLATED
SPRINKLES THIS EVENING. THE GFS WAS THE WET MODEL WHICH ACTUALLY
SHOWS SOME MEASURABLE QPF.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 359 AM CDT TUE MAY 12 2015
MODELS CONTINUE TO ADVERTISE A RAPID RETURN OF GULF MOISTURE TAKING
PLACE WEDNESDAY...WITH MODELS PROJECTING 850 MB DEW POINTS IN THE
10 TO 12C RANGE BY WEDNESDAY EVENING ACROSS THE REGION.
A LARGE UPPER TROUGH WILL BE TAKING SHAPE ALONG THE WEST COAST MID
TO LATE WEEK...WITH A LEAD SHORTWAVE EJECTING NORTHEAST THROUGH THE
PLAINS AHEAD OF THE TROUGH WEDNESDAY NIGHT INTO THURSDAY. THIS
SYSTEM IS SHOWN TO HAVE SOMEWHAT OF A NEGATIVE TILT...WHICH WILL
HELP DRAW MOISTURE WESTWARD INTO THE HIGH PLAINS. THE COMBINATION OF
STRONG LIFT AND MOISTURE TRANSPORT ON A SOUTHERLY LOW LEVEL
JET...CONTINUES TO GIVE CONFIDENCE THAT PRECIPITATION SHOULD RESULT
LATE WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT. WILL MAINTAIN THE
LIKELY POPS ALONG AND EAST OF HIGHWAY 83 WEDNESDAY NIGHT...AND ALSO
INTRODUCE EVENING LIKELY POPS ALONG A SURFACE TROUGH ACROSS THE
PANHANDLE INTO THE WESTERN SANDHILLS.
THE LEAD WAVE QUICKLY PASSES AND MOVES NORTHEAST AWAY FROM THE AREA
THURSDAY. ATTENTION THEN TURNS TO THE LONG WAVE TROUGH ALONG THE
WEST COAST. MODELS/ENSEMBLES PROJECT THIS TO MOVE EAST AS A CLOSED
SYSTEM DURING THE WEEKEND. THE GENERAL CONSENSUS IN THE MODELS AND
ENSEMBLE MEAN IS FOR THE CENTER OF THE SYSTEM TO TRACK ACROSS
WYOMING INTO SOUTH DAKOTA. THIS PUTS OUR AREA IN THE WARM MOIST
SECTOR. INSTABILITY LOOKS TO BE STRONG...AND AS DEEP LAYER SHEAR
INCREASES...STRONG TO SEVERE STORMS WILL LIKELY RESULT. WILL
INTRODUCE THE POTENTIAL FOR SEVERE THUNDERSTORMS IN THE HAZARDOUS
WEATHER OUTLOOK FOR FRIDAY AND SATURDAY. THE GFS AND ECMWF CONTINUE
TO DIFFER SOMEWHAT ON THE LOW LEVEL BOUNDARY PLACEMENT...BUT THE
LATEST TREND IS TO HOLD THE DRY LINE BACK TO THE WEST ACROSS WESTERN
NEBRASKA INTO WESTERN KANSAS...WHICH WOULD PLACE SEVERE STORM
DEVELOPMENT ACROSS THE FORECAST AREA OF WESTERN AND NORTH CENTRAL
NEBRASKA. WE WILL LIKELY BE IN THE MIDST OF THE MID LEVEL DRY SLOT
SUNDAY AS THE STORM SYSTEM CROSSES THE DAKOTAS...BUT AT LEAST SOME
CHANCE FOR SHOWERS IN WRAP AROUND PATTERN ACROSS NORTHERN NEBRASKA.
DRY WEATHER FOR MONDAY...THEN MORE CHANCES FOR RAIN NEXT WEEK BEYOND
THE FORECAST PERIOD...AS THE NEXT DEEP TROUGH MOVES EAST INTO THE
WESTERN CONUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1238 PM CDT TUE MAY 12 2015
FOR THE 18Z KLBF AND KVTN TAF...HIGH PRESSURE WILL BUILD EAST
ACROSS THE MID-MISSISSIPPI VALLEY WITH A BROAD AREA OF LOW
PRESSURE DEVELOPING WEST OF THE ROCKIES. THIS WILL INCREASE THE
PRESSURE GRADIENT ACROSS WEST CENTRAL NEBRASKA...PROVIDING FOR
INCREASING SOUTHERLY WINDS...WHICH WILL CONTINUE THROUGH THE
OVERNIGHT HOURS. LLWS MAY BECOME TROUBLESOME ACROSS OUR EASTERN
ZONES OVERNIGHT...MAINLY IMPACTING KONL...KBBW...AND POSSIBLY
KLBF. OTHERWISE INCREASING CLOUDINESS EARLY ON WEDNESDAY WILL LEAD
TO OVC SKIES BY EARLY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 359 AM CDT TUE MAY 12 2015
THE COMBINATION OF SEASONAL SNOW MELT IN THE UPPER SOUTH PLATTE
RIVER BASIN AND RECENT HEAVY PRECIPITATION OVER WESTERN NEBRASKA AND
NORTHEAST COLORADO WILL LEAD TO FLOODING ON THE SOUTH PLATTE AND
PLATTE RIVERS IN SOUTHWEST NEBRASKA LATER THIS WEEK AND INTO EARLY
NEXT WEEK. AT THIS TIME SOME UNCERTAINTY STILL REMAINS WITH THE
FORECAST AS KEY UPSTREAM GAUGES IN NORTHEAST COLORADO HAVE YET TO
CREST. HOWEVER...LATEST PROJECTIONS CONTINUE TO HIGHLIGHT AN
INCREASING THREAT FOR SIGNIFICANT FLOODING TO OCCUR...POTENTIALLY
NEAR SEPTEMBER 2013 FLOOD LEVELS.
RIVER STAGE FORECASTS WILL BE CLOSELY MONITORED AND UPDATED ONCE
MORE UPSTREAM RIVER DATA BECOMES AVAILABLE. PERSONS THAT LIVE IN
VULNERABLE AREAS ALONG THE SOUTH PLATTE RIVER AND PLATTE RIVER IN
SOUTHWEST NEBRASKA SHOULD PAY CLOSE ATTENTION TO FLOOD FORECASTS IN
THE COMING DAYS AND BE PREPARED TO TAKE PROPER ACTION.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...JACOBS
HYDROLOGY...MARTIN/TAYLOR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
646 PM EDT TUE MAY 12 2015
.SYNOPSIS...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED LATE
TODAY AHEAD OF A COLD FRONT TONIGHT. LESS HUMID AIR WILL ARRIVE
WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH PRESSURE MOVES
OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND WILL FEATURE A
GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES AS THE HIGH
MOVES OFF THE COAST.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 620 PM TUESDAY...SOME RE-ADJUSTMENTS OF THIS EVENING AND
OVERNIGHT POPS BASED ON LATEST TSTORM ACTIVITY BREAKING OUT ACROSS
THE EXTREME WESTERN PORTIONS OF THE ILM CWA AHEAD OF THE
APPROACHING COLD FRONT. IF THE ACTIVITY HOLDS TOGETHER AS IT
PUSHES EASTWARD...AND MEETS UP WITH THE SEA BREEZE...FURTHER
ACTIVITY COULD BLOSSOM. ALTHOUGH AT THIS TIME VIA KLTX 88D AND
VIS SAT IMAGERY...IT LOOKS LIKE THE SEA BREEZE HAS REACHED ITS
MAXIMUM PUSH INLAND. STILL...ENOUGH SFC FORCING SHOULD AID
CONTINUING THE CONVECTION AS IT PUSHES EASTWARD BEFORE THE MARINE
INFLUENCES BEHIND THE SEA BREEZE LIKELY PARTIALLY OR ENTIRELY
EXTINGUISHES IT. OVERALL...KEPT POPS IN THE LOWER CHANCE CATEGORY.
CURRENT MIN TEMP FORECAST LOOKS AOK...NO CHANGES NEEDED AT THIS
TIME.
PREVIOUS......................................................
AS OF 318 PM TUESDAY...VERY HOT DAY ONGOING ACROSS THE CWA WITH
LOTS OF 90-91 READINGS AND MID 60S TO AROUND 70 DEWPOINTS. THE SEA
BREEZE IS CLEARLY EVIDENT AS A LINE OF MODERATE CU FROM ABOUT
BURGAW TO TABOR CITY TO GEORGETOWN...MAKING MUCH MORE PROGRESS NW
INTO NC ON THE RESULTANT. THIS WILL CONTINUE TO SLOWLY PUSH WEST
THIS AFTN...BUT BASED OFF THE STRUGGLE OF THE CU TO GAIN VERTICAL
DEPTH...HAVE CUT BACK POP TO JUST A VERY ISOLATED SHOWER ALONG THE
SEA BREEZE.
PRE-FRONTAL TROUGH WILL APPROACH THIS EVENING AND IS LIKELY TO BE
OUR ONLY CHANCE FOR TSTMS TODAY. HRRR IS ALL OF A SUDDEN VERY
AGGRESSIVE WITH CONVECTION ALONG IT THIS EVENING AND RACING EAST
OFFSHORE EARLY IN THE NIGHTTIME PERIOD. WHILE THIS TIMING IS
APPROPRIATE...HAVE A HARD TIME PLACING MORE THAN 40 POP ANYWHERE FOR
ISOLATED TO SCATTERED TSTMS...MORE LIKE THE WRF SOLUTION. THINK THE
MID-LEVELS ARE JUST A BIT TOO WARM FOR STRONG CONVECTION...BUT THE
SPC SWODY1 MAINTAINS A MRGL RISK FOR OUR NC ZONES AND CANNOT RULE
OUT AN ISOLATED WIND GUST AS INVERTED-V SOUNDINGS ARE FORECAST AHEAD
OF THIS TROUGH.
PRE-FRONTAL TROUGH WILL MOVE OFFSHORE...AND THEN SUBSEQUENT COLD
FRONT WILL THEN TRAVERSE THE CWA LATE TONIGHT...MOVING OFFSHORE BY
DAWN WEDNESDAY. NO CONVECTION EXPECTED ALONG THE BOUNDARY...BUT A
SIGNIFICANT AIR MASS CHANGE WITH QUICKLY COOLING TEMPS AND MUCH
DRIER DEWPOINTS WILL OCCUR. LOWS TONIGHT WILL RANGE FROM AROUND 60
WELL INLAND...TO ABOUT 65 AT THE COAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 318 PM TUESDAY...CHANGING OF THE GUARD SO TO SPEAK IN TERMS
OF AIR MASS REPLACEMENT THIS PERIOD...AS A COLD FRONT MIGRATES
OFF THE COAST AROUND DAYBREAK WEDNESDAY. POST FRONTAL N WIND WILL
TEND TO NE WEDNESDAY ACCOMPANIED BY LOWERING DEWPOINTS IN THE 50S
MAKING FOR CONSIDERABLY LESS MUGGINESS...WITH MAXIMUMS OF UPPER
70S TO LOWER 80S WITH SUN. EARLY THURSDAY SEASONABLY COOL MINIMUMS
OF UPPER 50S TO LOWER 60S...MILDEST COAST. A COOLER DAY SETTING UP
THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES DROPS SOUTHEAST
TOWARD THE CAROLINAS...SUPPLYING A DOSE OF COOL AIR ADVECTION.
MINIMUMS EARLY FRIDAY SIMILAR TO THURSDAY UPPER 50S TO LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 318 PM TUESDAY...TRANSITION PERIOD AS HIGH PRESSURE MOVES
OFFSHORE FRIDAY AND RETURN FLOW RESUMES ACROSS THE AREA. THIS
WILL BRING A TREND UPWARD IN TEMPERATURES AND HUMIDITY WITH AN
INCREASING CHANCE OF SHOWERS/TSTMS AS A COLD FRONT GRADUALLY
APPROACHES FROM THE WEST THIS WEEKEND. THE FRONT MAY STALL OVER
THE AREA EARLY NEXT WEEK...OFFERING HIGH HUMIDITY AND EVEN A
BETTER CHANCE OF PCPN INTO EARLY NEXT WEEK. THIS REGIME SHOULD
RESULT IN TEMPERATURES NEAR OR SLIGHTLY ABOVE CLIMATE STANDARDS
FOR MIDDLE MAY.
&&
.AVIATION /00Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...SOME ISOLATED CONVECTION IS TRYING TO FORM AHEAD OF A
COLD FRONT THAT WILL SWING THROUGH THE REGION OVERNIGHT. SINCE WE
ARE LOSING OUR AFTERNOON HEATING...DO NOT THINK THE CONVECTION WILL
GET BETTER ORGANIZED BUT THERE COULD BE A BRIEF BUMP UP AS THE
CONVECTION ENCOUNTERS THE SEA BREEZE BOUNDARY IN A COUPLE OF HOURS.
OVERNIGHT...LOOK FOR ANY LEFTOVER CONVECTION TO REACH THE COAST BY
05Z. WINDS WILL SHIFT TO THE NORTH BEHIND THE COLD FRONT AFTER
MIDNIGHT...WITH MODERATE NORTHEAST FLOW EXPECTED FOR WEDNESDAY WITH
LESS HUMID CONDITIONS.
EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM TUESDAY...SSW-SW WINDS 15 TO 20 KT TO PREVAIL WELL
INTO TONIGHT...DIMINISHING TO 10-15 KT AS THE COLD FRONT
APPROACHES...AND LIKELY VEERING TO THE NW-N AROUND 15 KT BY
DAYBREAK WED AFTER FROPA. SIGNIFICANT SEAS WILL RUN 2 TO 4
FT...HIEST ACROSS THE WATERS FROM CAPE FEAR SOUTH TO LITTLE RIVER
INLET WHERE THE FETCH IS GREATEST GIVEN THE WIND DIRECTION. A 1 TO
2 FOOT 7-8 SECOND PERIOD GROUND SWELL REMAINS IDENTIFIABLE...BUT
WIND DRIVEN WAVES AT 4 TO 5 SECONDS WILL DOMINATE THE SIGNIFICANT
SEAS.
PREVIOUS.....................................................
AS OF 318 PM TUESDAY...HIGH PRESSURE OFFSHORE CONTINUES TO DRIVE
SW WINDS ACROSS THE WATERS THIS AFTN. SPEEDS ARE GENERALLY AROUND
15 KTS...BUT ARE REACHING 20 KTS WITH SOME BACKING TO THE SOUTH
NEAR THE COAST THANKS TO THE LOCAL SEA BREEZE ENHANCEMENT. THE SEA
BREEZE WILL EASE WITH LOSS OF HEATING...LEAVING 15 KT WINDS ACROSS
THE WATERS TONIGHT...ALONG WITH PERSISTENT 2-4 FT SEAS. THE WAVE
PERIOD WILL BE AROUND 7 SEC...SHORTER IN THE MORE WIND-DRIVEN SEA
BREEZE NEAR SHORE. A COLD FRONT WILL CROSS THE WATERS TOWARDS DAWN
ON WEDNESDAY...TURNING THE WINDS QUICKLY TO THE N/NW AND DRIVING
THE HIGHER WAVES AWAY FROM SHORE. A FEW SHOWERS AND TSTMS MAY
ACCOMPANY THIS FRONT...BUT WIDESPREAD CONVECTION IS NOT CURRENTLY
ANTICIPATED.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 318 PM TUESDAY...A COLD FRONTAL PASSAGE TO BRING A
WINDSHIFT TO NORTH ON THE WATERS WEDNESDAY...TENDING TO NE AND ENE
HEADING INTO LATER WEDNESDAY AND THURSDAY. NO ADVISORIES BUT NE GUSTS
TO 20 KT EXPECTED EARLY THURSDAY AS HIGH PRESSURE BUILDS FROM THE
NW. SEAS 2-3 FEET WEDNESDAY WILL BUILD TO 3-4 FEET THURSDAY. NO
TSTMS OR VISIBILITY RESTRICTIONS ON THE 0-20 NM WATERS EXPECTED
WED/THU/
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 318 PM TUESDAY...A TRANSITION TO A BERMUDA HIGH PRESSURE
PATTERN AS HIGH PRESSURE MOVES OFFSHORE AND RETURN SW WINDS PREVAIL
BEGINNING FRIDAY AND PERSISTING THROUGH THE WEEKEND. WARMING
DAYTIME TEMPERATURES WILL DRIVE A SEA BREEZE AND AFTERNOON GUSTS
TO 20 KT SHOULD BE EXPECTED NEAR SHORE OVER THE WEEKEND. ISOLATED
SHOWERS AND TSTMS SHOULD ALSO BE EXPECTED INTO THE WEEKEND AS S
AND SW WINDS INTRODUCE ADDITIONAL MOISTURE INTO THE REGION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...DCH/JDW
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
642 PM EDT TUE MAY 12 2015
.SYNOPSIS...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED LATE
TODAY AHEAD OF A COLD FRONT TONIGHT. LESS HUMID AIR WILL ARRIVE
WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH PRESSURE MOVES
OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND WILL FEATURE A
GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES AS THE HIGH
MOVES OFF THE COAST.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 620 PM TUESDAY...SOME RE-ADJUSTMENTS OF THIS EVENING AND
OVERNIGHT POPS BASED ON LATEST TSTORM ACTIVITY BREAKING OUT ACROSS
THE EXTREME WESTERN PORTIONS OF THE ILM CWA AHEAD OF THE
APPROACHING COLD FRONT. IF THE ACTIVITY HOLDS TOGETHER AS IT
PUSHES EASTWARD...AND MEETS UP WITH THE SEA BREEZE...FURTHER
ACTIVITY COULD BLOSSOM. ALTHOUGH AT THIS TIME VIA KLTX 88D AND
VIS SAT IMAGERY...IT LOOKS LIKE THE SEA BREEZE HAS REACHED ITS
MAXIMUM PUSH INLAND. STILL...ENOUGH SFC FORCING SHOULD AID
CONTINUING THE CONVECTION AS IT PUSHES EASTWARD BEFORE THE MARINE
INFLUENCES BEHIND THE SEA BREEZE LIKELY PARTIALLY OR ENTIRELY
EXTINGUISHES IT. OVERALL...KEPT POPS IN THE LOWER CHANCE CATEGORY.
CURRENT MIN TEMP FORECAST LOOKS AOK...NO CHANGES NEEDED AT THIS
TIME.
PREVIOUS......................................................
AS OF 318 PM TUESDAY...VERY HOT DAY ONGOING ACROSS THE CWA WITH
LOTS OF 90-91 READINGS AND MID 60S TO AROUND 70 DEWPOINTS. THE SEA
BREEZE IS CLEARLY EVIDENT AS A LINE OF MODERATE CU FROM ABOUT
BURGAW TO TABOR CITY TO GEORGETOWN...MAKING MUCH MORE PROGRESS NW
INTO NC ON THE RESULTANT. THIS WILL CONTINUE TO SLOWLY PUSH WEST
THIS AFTN...BUT BASED OFF THE STRUGGLE OF THE CU TO GAIN VERTICAL
DEPTH...HAVE CUT BACK POP TO JUST A VERY ISOLATED SHOWER ALONG THE
SEA BREEZE.
PRE-FRONTAL TROUGH WILL APPROACH THIS EVENING AND IS LIKELY TO BE
OUR ONLY CHANCE FOR TSTMS TODAY. HRRR IS ALL OF A SUDDEN VERY
AGGRESSIVE WITH CONVECTION ALONG IT THIS EVENING AND RACING EAST
OFFSHORE EARLY IN THE NIGHTTIME PERIOD. WHILE THIS TIMING IS
APPROPRIATE...HAVE A HARD TIME PLACING MORE THAN 40 POP ANYWHERE FOR
ISOLATED TO SCATTERED TSTMS...MORE LIKE THE WRF SOLUTION. THINK THE
MID-LEVELS ARE JUST A BIT TOO WARM FOR STRONG CONVECTION...BUT THE
SPC SWODY1 MAINTAINS A MRGL RISK FOR OUR NC ZONES AND CANNOT RULE
OUT AN ISOLATED WIND GUST AS INVERTED-V SOUNDINGS ARE FORECAST AHEAD
OF THIS TROUGH.
PRE-FRONTAL TROUGH WILL MOVE OFFSHORE...AND THEN SUBSEQUENT COLD
FRONT WILL THEN TRAVERSE THE CWA LATE TONIGHT...MOVING OFFSHORE BY
DAWN WEDNESDAY. NO CONVECTION EXPECTED ALONG THE BOUNDARY...BUT A
SIGNIFICANT AIR MASS CHANGE WITH QUICKLY COOLING TEMPS AND MUCH
DRIER DEWPOINTS WILL OCCUR. LOWS TONIGHT WILL RANGE FROM AROUND 60
WELL INLAND...TO ABOUT 65 AT THE COAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 318 PM TUESDAY...CHANGING OF THE GUARD SO TO SPEAK IN TERMS
OF AIR MASS REPLACEMENT THIS PERIOD...AS A COLD FRONT MIGRATES
OFF THE COAST AROUND DAYBREAK WEDNESDAY. POST FRONTAL N WIND WILL
TEND TO NE WEDNESDAY ACCOMPANIED BY LOWERING DEWPOINTS IN THE 50S
MAKING FOR CONSIDERABLY LESS MUGGINESS...WITH MAXIMUMS OF UPPER
70S TO LOWER 80S WITH SUN. EARLY THURSDAY SEASONABLY COOL MINIMUMS
OF UPPER 50S TO LOWER 60S...MILDEST COAST. A COOLER DAY SETTING UP
THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES DROPS SOUTHEAST
TOWARD THE CAROLINAS...SUPPLYING A DOSE OF COOL AIR ADVECTION.
MINIMUMS EARLY FRIDAY SIMILAR TO THURSDAY UPPER 50S TO LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 318 PM TUESDAY...TRANSITION PERIOD AS HIGH PRESSURE MOVES
OFFSHORE FRIDAY AND RETURN FLOW RESUMES ACROSS THE AREA. THIS
WILL BRING A TREND UPWARD IN TEMPERATURES AND HUMIDITY WITH AN
INCREASING CHANCE OF SHOWERS/TSTMS AS A COLD FRONT GRADUALLY
APPROACHES FROM THE WEST THIS WEEKEND. THE FRONT MAY STALL OVER
THE AREA EARLY NEXT WEEK...OFFERING HIGH HUMIDITY AND EVEN A
BETTER CHANCE OF PCPN INTO EARLY NEXT WEEK. THIS REGIME SHOULD
RESULT IN TEMPERATURES NEAR OR SLIGHTLY ABOVE CLIMATE STANDARDS
FOR MIDDLE MAY.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...THE SEA BREEZE HAS DEVELOPED WITH PRETTY MUCH A STEADY
S-SSW WIND AROUND 13KT AT THE COASTAL TERMINALS. WINDS AT
KFLO/KLBT ARE SW 8-12KT. TERMINALS ARE VFR...AND THE IFR CIGS JUST
NORTH OF CRE SHOULD REMAIN JUST AWAY FROM THE TERMINAL. CONFIDENCE
IS MODERATE TO HIGH KCRE WILL REMAIN VFR.
A COLD FRONT WILL APPROACH AND MOVE THROUGH THE TERMINALS THIS TAF
PERIOD. IT WILL BE UNSTABLE ENOUGH FOR SHOWERS AND THUNDERSTORMS TO
DEVELOP THIS EVENING. APPEARS THE BEST AREA FOR DEVELOPMENT WILL BE
BETWEEN THE INLAND AND COASTAL TERMINALS WHERE SURFACE WINDS ARE
CONVERGING...AND LATEST HIGH RES GUIDANCE SUGGESTS THIS WILL NOT
EVEN REACH THE COASTAL TERMINALS AS IT STABILIZES BEHIND THE SEA
BREEZE. CONVECTION SHOULD TAPER OFF IN THE EVENING. THE COLD FRONT
WILL MOVE THROUGH DURING OVERNIGHT HOURS. PRECIPITATION WILL DROP
AFTER THE FRONT MOVES THROUGH. VFR WILL CONTINUE INTO THE MORNING
HOURS WITH VFR/NE WINDS AFTER SUNRISE.
EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM TUESDAY...SSW-SW WINDS 15 TO 20 KT TO PREVAIL WELL
INTO TONIGHT...DIMINISHING TO 10-15 KT AS THE COLD FRONT
APPROACHES...AND LIKELY VEERING TO THE NW-N AROUND 15 KT BY
DAYBREAK WED AFTER FROPA. SIGNIFICANT SEAS WILL RUN 2 TO 4
FT...HIEST ACROSS THE WATERS FROM CAPE FEAR SOUTH TO LITTLE RIVER
INLET WHERE THE FETCH IS GREATEST GIVEN THE WIND DIRECTION. A 1 TO
2 FOOT 7-8 SECOND PERIOD GROUND SWELL REMAINS IDENTIFIABLE...BUT
WIND DRIVEN WAVES AT 4 TO 5 SECONDS WILL DOMINATE THE SIGNIFICANT
SEAS.
PREVIOUS.....................................................
AS OF 318 PM TUESDAY...HIGH PRESSURE OFFSHORE CONTINUES TO DRIVE
SW WINDS ACROSS THE WATERS THIS AFTN. SPEEDS ARE GENERALLY AROUND
15 KTS...BUT ARE REACHING 20 KTS WITH SOME BACKING TO THE SOUTH
NEAR THE COAST THANKS TO THE LOCAL SEA BREEZE ENHANCEMENT. THE SEA
BREEZE WILL EASE WITH LOSS OF HEATING...LEAVING 15 KT WINDS ACROSS
THE WATERS TONIGHT...ALONG WITH PERSISTENT 2-4 FT SEAS. THE WAVE
PERIOD WILL BE AROUND 7 SEC...SHORTER IN THE MORE WIND-DRIVEN SEA
BREEZE NEAR SHORE. A COLD FRONT WILL CROSS THE WATERS TOWARDS DAWN
ON WEDNESDAY...TURNING THE WINDS QUICKLY TO THE N/NW AND DRIVING
THE HIGHER WAVES AWAY FROM SHORE. A FEW SHOWERS AND TSTMS MAY
ACCOMPANY THIS FRONT...BUT WIDESPREAD CONVECTION IS NOT CURRENTLY
ANTICIPATED.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 318 PM TUESDAY...A COLD FRONTAL PASSAGE TO BRING A
WINDSHIFT TO NORTH ON THE WATERS WEDNESDAY...TENDING TO NE AND ENE
HEADING INTO LATER WEDNESDAY AND THURSDAY. NO ADVISORIES BUT NE GUSTS
TO 20 KT EXPECTED EARLY THURSDAY AS HIGH PRESSURE BUILDS FROM THE
NW. SEAS 2-3 FEET WEDNESDAY WILL BUILD TO 3-4 FEET THURSDAY. NO
TSTMS OR VISIBILITY RESTRICTIONS ON THE 0-20 NM WATERS EXPECTED
WED/THU/
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 318 PM TUESDAY...A TRANSITION TO A BERMUDA HIGH PRESSURE
PATTERN AS HIGH PRESSURE MOVES OFFSHORE AND RETURN SW WINDS PREVAIL
BEGINNING FRIDAY AND PERSISTING THROUGH THE WEEKEND. WARMING
DAYTIME TEMPERATURES WILL DRIVE A SEA BREEZE AND AFTERNOON GUSTS
TO 20 KT SHOULD BE EXPECTED NEAR SHORE OVER THE WEEKEND. ISOLATED
SHOWERS AND TSTMS SHOULD ALSO BE EXPECTED INTO THE WEEKEND AS S
AND SW WINDS INTRODUCE ADDITIONAL MOISTURE INTO THE REGION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...DCH/JDW
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
318 PM EDT TUE MAY 12 2015
.SYNOPSIS...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE EXPECTED LATE
TODAY AHEAD OF A COLD FRONT TONIGHT. LESS HUMID AIR WILL ARRIVE
WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH PRESSURE MOVES
OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND WILL FEATURE A
GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES AS THE HIGH
MOVES OFF THE COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 318 PM TUESDAY...VERY HOT DAY ONGOING ACROSS THE CWA WITH
LOTS OF 90-91 READINGS AND MID 60S TO AROUND 70 DEWPOINTS. THE SEA
BREEZE IS CLEARLY EVIDENT AS A LINE OF MODERATE CU FROM ABOUT
BURGAW TO TABOR CITY TO GEORGETOWN...MAKING MUCH MORE PROGRESS NW
INTO NC ON THE RESULTANT. THIS WILL CONTINUE TO SLOWLY PUSH WEST
THIS AFTN...BUT BASED OFF THE STRUGGLE OF THE CU TO GAIN VERTICAL
DEPTH...HAVE CUT BACK POP TO JUST A VERY ISOLATED SHOWER ALONG THE
SEA BREEZE.
PRE-FRONTAL TROUGH WILL APPROACH THIS EVENING AND IS LIKELY TO BE
OUR ONLY CHANCE FOR TSTMS TODAY. HRRR IS ALL OF A SUDDEN VERY
AGGRESSIVE WITH CONVECTION ALONG IT THIS EVENING AND RACING EAST
OFFSHORE EARLY IN THE NIGHTTIME PERIOD. WHILE THIS TIMING IS
APPROPRIATE...HAVE A HARD TIME PLACING MORE THAN 40 POP ANYWHERE FOR
ISOLATED TO SCATTERED TSTMS...MORE LIKE THE WRF SOLUTION. THINK THE
MID-LEVELS ARE JUST A BIT TOO WARM FOR STRONG CONVECTION...BUT THE
SPC SWODY1 MAINTAINS A MRGL RISK FOR OUR NC ZONES AND CANNOT RULE
OUT AN ISOLATED WIND GUST AS INVERTED-V SOUNDINGS ARE FORECAST AHEAD
OF THIS TROUGH.
PRE-FRONTAL TROUGH WILL MOVE OFFSHORE...AND THEN SUBSEQUENT COLD
FRONT WILL THEN TRAVERSE THE CWA LATE TONIGHT...MOVING OFFSHORE BY
DAWN WEDNESDAY. NO CONVECTION EXPECTED ALONG THE BOUNDARY...BUT A
SIGNIFICANT AIR MASS CHANGE WITH QUICKLY COOLING TEMPS AND MUCH
DRIER DEWPOINTS WILL OCCUR. LOWS TONIGHT WILL RANGE FROM AROUND 60
WELL INLAND...TO ABOUT 65 AT THE COAST.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 318 PM TUESDAY...CHANGING OF THE GUARD SO TO SPEAK IN TERMS
OF AIR MASS REPLACEMENT THIS PERIOD...AS A COLD FRONT MIGRATES
OFF THE COAST AROUND DAYBREAK WEDNESDAY. POST FRONTAL N WIND WILL
TEND TO NE WEDNESDAY ACCOMPANIED BY LOWERING DEWPOINTS IN THE 50S
MAKING FOR CONSIDERABLY LESS MUGGINESS...WITH MAXIMUMS OF UPPER
70S TO LOWER 80S WITH SUN. EARLY THURSDAY SEASONABLY COOL MINIMUMS
OF UPPER 50S TO LOWER 60S...MILDEST COAST. A COOLER DAY SETTING UP
THURSDAY AS HIGH PRESSURE FROM THE GREAT LAKES DROPS SOUTHEAST
TOWARD THE CAROLINAS...SUPPLYING A DOSE OF COOL AIR ADVECTION.
MINIMUMS EARLY FRIDAY SIMILAR TO THURSDAY UPPER 50S TO LOWER 60S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 318 PM TUESDAY...TRANSITION PERIOD AS HIGH PRESSURE MOVES
OFFSHORE FRIDAY AND RETURN FLOW RESUMES ACROSS THE AREA. THIS
WILL BRING A TREND UPWARD IN TEMPERATURES AND HUMIDITY WITH AN
INCREASING CHANCE OF SHOWERS/TSTMS AS A COLD FRONT GRADUALLY
APPROACHES FROM THE WEST THIS WEEKEND. THE FRONT MAY STALL OVER
THE AREA EARLY NEXT WEEK...OFFERING HIGH HUMIDITY AND EVEN A
BETTER CHANCE OF PCPN INTO EARLY NEXT WEEK. THIS REGIME SHOULD
RESULT IN TEMPERATURES NEAR OR SLIGHTLY ABOVE CLIMATE STANDARDS
FOR MIDDLE MAY.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...THE SEA BREEZE HAS DEVELOPED WITH PRETTY MUCH A STEADY
S-SSW WIND AROUND 13KT AT THE COASTAL TERMINALS. WINDS AT
KFLO/KLBT ARE SW 8-12KT. TERMINALS ARE VFR...AND THE IFR CIGS JUST
NORTH OF CRE SHOULD REMAIN JUST AWAY FROM THE TERMINAL. CONFIDENCE
IS MODERATE TO HIGH KCRE WILL REMAIN VFR.
A COLD FRONT WILL APPROACH AND MOVE THROUGH THE TERMINALS THIS TAF
PERIOD. IT WILL BE UNSTABLE ENOUGH FOR SHOWERS AND THUNDERSTORMS TO
DEVELOP THIS EVENING. APPEARS THE BEST AREA FOR DEVELOPMENT WILL BE
BETWEEN THE INLAND AND COASTAL TERMINALS WHERE SURFACE WINDS ARE
CONVERGING...AND LATEST HIGH RES GUIDANCE SUGGESTS THIS WILL NOT
EVEN REACH THE COASTAL TERMINALS AS IT STABILIZES BEHIND THE SEA
BREEZE. CONVECTION SHOULD TAPER OFF IN THE EVENING. THE COLD FRONT
WILL MOVE THROUGH DURING OVERNIGHT HOURS. PRECIPITATION WILL DROP
AFTER THE FRONT MOVES THROUGH. VFR WILL CONTINUE INTO THE MORNING
HOURS WITH VFR/NE WINDS AFTER SUNRISE.
EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 318 PM TUESDAY...HIGH PRESSURE OFFSHORE CONTINUES TO DRIVE
SW WINDS ACROSS THE WATERS THIS AFTN. SPEEDS ARE GENERALLY AROUND
15 KTS...BUT ARE REACHING 20 KTS WITH SOME BACKING TO THE SOUTH
NEAR THE COAST THANKS TO THE LOCAL SEA BREEZE ENHANCEMENT. THE SEA
BREEZE WILL EASE WITH LOSS OF HEATING...LEAVING 15 KT WINDS ACROSS
THE WATERS TONIGHT...ALONG WITH PERSISTENT 2-4 FT SEAS. THE WAVE
PERIOD WILL BE AROUND 7 SEC...SHORTER IN THE MORE WIND-DRIVEN SEA
BREEZE NEAR SHORE. A COLD FRONT WILL CROSS THE WATERS TOWARDS DAWN
ON WEDNESDAY...TURNING THE WINDS QUICKLY TO THE N/NW AND DRIVING
THE HIGHER WAVES AWAY FROM SHORE. A FEW SHOWERS AND TSTMS MAY
ACCOMPANY THIS FRONT...BUT WIDESPREAD CONVECTION IS NOT CURRENTLY
ANTICIPATED.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 318 PM TUESDAY...A COLD FRONTAL PASSAGE TO BRING A
WINDSHIFT TO NORTH ON THE WATERS WEDNESDAY...TENDING TO NE AND ENE
HEADING INTO LATER WEDNESDAY AND THURSDAY. NO ADVISORIES BUT NE GUSTS
TO 20 KT EXPECTED EARLY THURSDAY AS HIGH PRESSURE BUILDS FROM THE
NW. SEAS 2-3 FEET WEDNESDAY WILL BUILD TO 3-4 FEET THURSDAY. NO
TSTMS OR VISIBILITY RESTRICTIONS ON THE 0-20 NM WATERS EXPECTED
WED/THU/
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 318 PM TUESDAY...A TRANSITION TO A BERMUDA HIGH PRESSURE
PATTERN AS HIGH PRESSURE MOVES OFFSHORE AND RETURN SW WINDS PREVAIL
BEGINNING FRIDAY AND PERSISTING THROUGH THE WEEKEND. WARMING
DAYTIME TEMPERATURES WILL DRIVE A SEA BREEZE AND AFTERNOON GUSTS
TO 20 KT SHOULD BE EXPECTED NEAR SHORE OVER THE WEEKEND. ISOLATED
SHOWERS AND TSTMS SHOULD ALSO BE EXPECTED INTO THE WEEKEND AS S
AND SW WINDS INTRODUCE ADDITIONAL MOISTURE INTO THE REGION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MJC
LONG TERM...MJC
AVIATION...MRR/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
124 PM EDT TUE MAY 12 2015
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AHEAD OF A
COLD FRONT. LESS HUMID AIR ARRIVES ON WEDNESDAY AND SHOULD LAST INTO
THURSDAY AS HIGH PRESSURE MOVES OVERHEAD. THE LATTER PART OF THE
WEEK AND WEEKEND WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND
THUNDERSTORM CHANCES AS THE HIGH MOVES OFF THE COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...HOT AND HUMID DAY ONGOING ACROSS THE CWA
EVEN AT THIS EARLY HOUR. AFTER STARTING FROM LOWS AROUND 70...TEMPS
ARE SHOOTING UP QUICKLY THIS MORNING THANKS TO 950MB TEMPS CLOSE TO
22C ON THE 8AM KCHS U/A SOUNDING. HIGH PRESSURE CENTERED WELL
OFFSHORE IS PUMPING RETURN FLOW INTO THE CAROLINAS...WHICH IS
STRENGTHENING WARM ADVECTION IN A PRE-FRONTAL AIRMASS. THE
COMBINATION OF THIS HEAT AND DEWPOINT TEMPS AROUND 70 WILL DRIVE
HEAT INDICES INTO THE MID 90S AWAY FROM THE COAST TODAY...THE MOST
UNCOMFORTABLE DAY OF 2015 SO FAR.
THIS HUMID AIR MASS WILL DRIVE INSTABILITY THIS AFTN...AND
CONVECTION IS ONCE AGAIN EXPECTED ACROSS THE AREA. VERY STEEP LR`S
UP TO 800MB WILL DRIVE RAPID UPDRAFTS...AND SBCAPE IS FORECAST TO
RISE TO AROUND 3000 J/KG...POSSIBLY HIGHER RIGHT ALONG THE SEA
BREEZE. THIS WILL SERVE AS THE FUEL FOR STORMS TODAY...WHICH SHOULD
DEVELOP ALONG THE SEA BREEZE...AND THEN LATER ALONG A PRE-FRONTAL
TROUGH APPROACHING FROM THE WEST. WHILE RESIDUAL BOUNDARIES MAY FIRE
WEAK STORMS...MID LEVEL TEMPS ARE NOT EXCEEDINGLY COOL (-8C AT
500MB) SO WIDESPREAD STRONG UPDRAFTS ARE NOT ANTICIPATED.
STILL...ENOUGH FORCING WILL DRIVE PARCELS UP INTO DECENT HAIL-ZONE
INSTABILITY...AND AN INVERTED-V TYPE SIGNATURE IS PROGGED WELL
INLAND AHEAD OF THE PRE-FRONTAL TROUGH. BULK-SHEAR VALUES STRUGGLE
TO AROUND 20 KTS...SO WIDESPREAD STORM ORGANIZATION IS
UNLIKELY...BUT PULSE STORMS AND AT LEAST SOME LINEAR FEATURES ALONG
THE PRE-FRONTAL TROUGH WILL HAVE THE POTENTIAL TO PRODUCE AN
ISOLATED WIND GUST OR LARGE HAIL STONE THIS AFTN. HIGH-RES HRRR AND
NSSL WRF SUGGEST ONLY ISOLATED STORMS UNTIL THE PRE-FRONTAL TROUGH
THIS EVENING...WHICH WILL BE THE PRIMARY DRIVER OF CONVECTION TODAY.
BY THIS EVENING HOWEVER...WE BEGIN TO LOSE HEATING...AND HAVE CAPPED
POP IN THE HIGH CHC RANGE. HIGHEST PROBABILITY FOR STORMS LOOKS TO
BE ACROSS THE MIDDLE-PART OF THE CWA WHERE THE WESTWARD ADVANCING
SEA BREEZE WILL INTERACT WITH THE EASTWARD MOVING TROUGH.
CONVECTION WILL WANE AFTER DARK...AND LITTLE FANFARE IS EXPECTED
WITH THE ACTUAL FROPA TONIGHT. HOWEVER...A SIGNIFICANT AIRMASS
CHANGE WILL ACCOMPANY THIS FRONT...WITH MUCH DRIER AIR AND LOWS
DROPPING INTO THE MID 60S AT THE COAST...AROUND 60 WELL INLAND.
ALSO NEED TO NOTE A PERSISTENT AREA OF SEA-STRATUS FROM ABOUT NORTH
MYRTLE BEACH TO BALD HEAD ISLAND. SHELF WATERS MUST BE JUST COOL
ENOUGH TO TAP INTO THE IDEALIZED RESIDENCE PARCEL TIMES ENCOUNTERED
BY THE W/SW WINDS IN ORDER TO SATURATE IN THIS AREA. THE COMBINATION
OF THE BACKING WINDS WITHIN THE SEA BREEZE...AS WELL AS SIGNIFICANT
HEATING JUST INLAND...SHOULD BREAK APART THIS STRATUS BY EARLY
AFTN...BUT IT IS UNLIKELY THE NEAR-COAST AREA HERE WILL EXPERIENCE
THE HOT/HUMID/SUNNY DAY GOING ON ELSEWHERE ACROSS THE CWA.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY... SOME VERY PLEASANT WEATHER EXPECTED THROUGH THE
PERIOD. HIGH PRESSURE WELL TO OUR NORTH WILL SHOW LITTLE MOVEMENT
WEDNESDAY WHILE THE TUESDAY NIGHT COLD FRONT STALLS WELL TO OUR
SOUTH. IN BETWEEN THE TWO WE WILL SEE A N TO NE FLOW LOCALLY THAT
WILL BRING SOME MUCH LOWER DEWPOINTS. A MILD LEVEL RIDGE WILL BE
JUST TO OUR WEST ALLOWING FOR DEEP LAYER DRY AIR AND AMPLE SUNSHINE.
ON THURSDAY THE HIGH WILL MOVE CLOSER TO THE REGION KEEPING
TEMPERATURES A BIT BELOW CLIMATOLOGY. A LITTLE MOISTURE RETURN MAY
GET UNDERWAY THURSDAY NIGHT AS THE HIGH MOVES FURTHER TO THE EAST,
MAINLY OVER WESTERN ZONE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...RETURN FLOW ON FRIDAY AND SATURDAY AS HIGH
PRESSURE SITES OFF THE COAST. THE MID LEVEL RIDGE WILL BE OVERHEAD
HOWEVER PRECLUDING DEEP MOISTURE AND CONFINING IT TO THE LOWER
LEVELS. SO WHILE A STRAY SHOWER OR THUNDERSTORM CANNOT BE RULED
OUT ANY COVERAGE SHOULD BE MINIMAL. OVER THE WEEKEND AND EVEN INTO
MONDAY FOR THAT MATTER THE MID LEVEL RIDGING APPEARS TO RESURGE.
DESPITE THIS THE GFS AND ECMWF BOTH DEPICT AN INCREASE IN
PRECIPITATION COVERAGE. WHILE THE CONTINUED MOISTENING OF THE LOW
LEVELS DOES IN FACT ARGUE FOR THIS THE MID LEVEL DRYNESS PROBABLY
MEANS THAT ITS RATHER SUBTLE. TEMPERATURES MEANWHILE WILL GROW
WARMER EACH DAY AND NIGHT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY /...
AS OF 18Z...THE SEA BREEZE HAS DEVELOPED WITH PRETTY MUCH A STEADY S-
SSW WIND AROUND 13KT AT THE COASTAL TERMINALS. WINDS AT KFLO/KLBT
ARE SW 8-12KT. TERMINALS ARE VFR...AND THE IFR CIGS JUST NORTH OF
CRE SHOULD REMAIN JUST AWAY FROM THE TERMINAL. CONFIDENCE IS
MODERATE TO HIGH KCRE WILL REMAIN VFR.
A COLD FRONT WILL APPROACH AND MOVE THROUGH THE TERMINALS THIS TAF
PERIOD. IT WILL BE UNSTABLE ENOUGH FOR SHOWERS AND THUNDERSTORMS TO
DEVELOP THIS EVENING. APPEARS THE BEST AREA FOR DEVELOPMENT WILL BE
BETWEEN THE INLAND AND COASTAL TERMINALS WHERE SURFACE WINDS ARE
CONVERGING...AND LATEST HIGH RES GUIDANCE SUGGESTS THIS WILL NOT
EVEN REACH THE COASTAL TERMINALS AS IT STABILIZES BEHIND THE SEA
BREEZE. CONVECTION SHOULD TAPER OFF IN THE EVENING. THE COLD FRONT
WILL MOVE THROUGH DURING OVERNIGHT HOURS. PRECIPITATION WILL DROP
AFTER THE FRONT MOVES THROUGH. VFR WILL CONTINUE INTO THE MORNING
HOURS WITH VFR/NE WINDS AFTER SUNRISE.
EXTENDED OUTLOOK...VFR. SCATTERED SHOWERS FRIDAY.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...HIGH PRESSURE OFFSHORE IS THE DOMINANT
SYNOPTIC FEATURE ACROSS THE WATERS TODAY...DRIVING SW FLOW AND WINDS
OF 10-15 KTS ACROSS THE WATERS. LOCAL ENHANCEMENTS OF UP TO 20
KTS...ALONG WITH A BACKING IN DIRECTION TO THE SOUTH...IS LIKELY
ALONG THE SEA BREEZE THROUGH THE AFTN AS WELL. OTHER THAN SOME
CHOPPY WATERS WITHIN THE NEAR SHORE WATERS THANKS TO THE SEA
BREEZE...WAVE HEIGHTS ARE EXPECTED TO PERSIST AT 2-4 FT WITH A 6-7
SEC PERIOD DOMINANT. A COLD FRONT WILL CROSS THE WATERS LATE TONIGHT
TURNING WINDS TO THE N/NW AT AROUND 15 KTS...AND PUSHING THE HIGHEST
SEAS AWAY FROM THE COAST.
SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM TUESDAY... TUESDAY NIGHT`S FROPA WILL BRING A
NORTHERLY FLOW ON WEDNESDAY. SURFACE HIGH REMAINS UP IN THE GREAT
LAKES SO THE FLOW WILL BE QUITE LIGHT LOCALLY AND SEAS LIKELY JUST
2 TO 3 FT. JUST A SLIGHT VEER WEDNESDAY NIGHT WITH FLOW POSSIBLY
GOING LIGHT AND VARIABLE FOR A TIME. THE HIGH EXTENDS JUST
SLIGHTLY SOUTH ON THURSDAY WHILE PROGRESSING EAST. NE WINDS COULD
INCREASE BY A CATEGORY AND BECOME A LITTLE GUSTY. THE COAST-
PARALLEL FLOW WILL PRECLUDE MUCH BUILDING OF SEAS HOWEVER.
.LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY... THE HIGH TO OUR NORTH PROGRESSES FURTHER
EAST ON FRIDAY LEADING TO MORE VEERING LOCALLY. FRIDAY MAY SEE
ONSHORE/EASTERLY FLOW MOST OF THE DAY WHILE A SOUTHERLY COMPONENT
TRIES TO GET ESTABLISHED MAINLY OVER SOUTHERN ZONES. ON SATURDAY
WE TRANSITION TO A FAIRLY NORMAL RETURN FLOW AROUND HIGH PRESSURE
OFF THE EAST COAST. NOT A BERMUDA HIGH THOUGH WHICH TYPICALLY
BRINGS SOUTHWESTERLY FLOW...THE WEEKEND WILL LIKELY SEE SOUTHEAST
INSTEAD. THERE COULD BE A VERY GRADUAL INCREASE IN WAVE PERIOD AS
A SWELL BECOMES ESTABLISHED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$ SYNOPSIS...MBB
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...MRR/JDW
MARINE...JDW/MBB
AREA FORECAST DISCUSSION
NWS NORMAN OK
1248 PM CDT TUE MAY 12 2015
.AVIATION...
18Z TAFS...VFR CONDITIONS EXPECTED MUCH OF THE TAF PERIOD. FROM
06Z THROUGH 12Z WED...LOW LEVEL MOISTURE WILL INCREASE...RESULTING
MVFR/IFR CIGS SPREADING FROM SW TO NE ACROSS THE REGION...ALONG
WITH LIGHT TO MODERATE RAINFALL. RAIN MAY BECOME HEAVY AT TIMES
DURING THE DAY WED...WITH VSBYS LESS THAN 2 MILES...BUT CONFIDENCE
IN THESE VSBYS IS TOO LOW TO MENTION IN TAFS. FOR NOW WILL GO WITH
PREVAILING -RA AT SOUTHWESTERN TERMINALS...WHERE CONFIDENCE IN
RAIN IS HIGHER.
&&
.PREV DISCUSSION... /ISSUED 1100 AM CDT TUE MAY 12 2015/
UPDATE...
ADJUSTMENTS TO CLOUD COVER AND TEMPERATURES.
DISCUSSION...
ALTHOUGH MID-HIGH CLOUDS WILL THIN SOMEWHAT FROM WEST TO EAST
THROUGH THE AFTERNOON...MOST AREAS OUTSIDE OF FAR NORTH/WEST
OKLAHOMA WILL STAY MOSTLY CLOUDY TODAY AND WILL KEEP TEMPS FROM
GETTING TOO WARM. INCREASED CLOUD COVER AND LOWERED HIGHS A FEW
DEGREES NEAR AND SOUTH OF OKC.
A FEW SPRINKLES MAY MOVE INTO WESTERN NORTH TEXAS THIS AFTERNOON
BUT MAIN RAIN EVENT STILL APPEARS TO COMMENCE AFTER MIDNIGHT
TONIGHT AND MAINLY DURING THE DAY TOMORROW. FLASH FLOOD WATCH WILL
BE CONTINUED FOR LATE TONIGHT AND TOMORROW. LATEST RUN OF MODELS
LOOKS FAVORABLE FOR HEAVIER RAIN AXIS TO BE FARTHER WEST...SOME OF
WHICH WILL BE JUST OUTSIDE OF CURRENT WATCH. HOWEVER...AREAS WEST
OF THE FLASH FLOOD WATCH CAN TAKE MUCH MORE RAIN THAN THE RAIN
SOAKED CENTRAL/SOUTHEAST OKLAHOMA. WE WILL TAKE A CLOSER LOOK TO
EXPANDING THE WATCH BUT IT WILL NOT BE DONE WITH THIS UPDATE.
ALTHOUGH SEVERE WEATHER DOES LOOK POSSIBLE FRIDAY...STILL APPEARS
THAT SATURDAY COULD BE THE PRIMARY IMPACT DAY FOR SEVERE WEATHER.
PREV DISCUSSION... /ISSUED 615 AM CDT TUE MAY 12 2015/
AVIATION...
12Z TAFS...THIN BAND OF SHOWERS AND EMBEDDED STORMS ACROSS CENTRAL
AND WEST TEXAS IS EXPECTED TO REMAIN SOUTH OF TAF SITES
THROUGH THE DAY. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH
6Z...BEFORE CEILINGS LOWER ACROSS WESTERN NORTH TEXAS AND
SOUTHWEST OKLAHOMA AS PRECIPITATION DEVELOPS.
PREV DISCUSSION... /ISSUED 325 AM CDT TUE MAY 12 2015/
DISCUSSION...
EAST TO SOUTHEAST WINDS WILL DEVELOP TODAY AS SURFACE HIGH
PRESSURE OVER KANSAS BUILDS EAST. MEANWHILE...CONVECTION ALONG
THE EAST TEXAS COAST WILL DELAY THE RETURN OF DEEP MOISTURE
NORTHWARD. SCATTERED SHOWERS AND A FEW STORMS HAVE FORMED WITHIN
AN AREA OF MID-LEVEL MOISTURE RETURN OVER CENTRAL AND WEST TEXAS.
THE HRRR SORTA HAS A HANDLE ON THIS AND GRADUALLY WEAKENS IT
DURING THE MORNING...WHILE THE NAM12 IS MORE AGGRESSIVE IN
DEVELOPING CONVECTION IN WESTERN NORTH TEXAS. FOR NOW WILL KEEP
IN CHANCE POPS FOR OUR TEXAS COUNTIES.
ANOTHER HEAVY RAIN EVENT SEEMS LIKELY LATE TUESDAY NIGHT INTO
WEDNESDAY. MODELS ARE SIMILAR IN TRACKING A PROGRESSIVE TROUGH
ACROSS THE SOUTHWESTERN STATES TONIGHT AND THEN OVER WEST TEXAS
AND OKLAHOMA WEDNESDAY INTO EARLY THURSDAY. DEEP MOISTURE IN PLACE
OVER SOUTH TEXAS WILL BE TRANSPORTED NORTHWARD TONIGHT INTO
WEDNESDAY IN ADVANCE OF THE TROUGH. THE BEST COMBINATION OF UPPER
AND LOW LEVEL JET FEATURES...SHOULD FOCUS THE HEAVIEST RAIN OVER
WESTERN NORTH TEXAS AND SOUTHWEST OKLAHOMA EARLY WEDNESDAY...WITH
A GRADUALLY SHIFT NORTH AND EAST DURING THE AFTERNOON AND NIGHT.
WIDESPREAD 2 INCH RAIN AMOUNTS ARE LIKELY WITH 3 TO 4 INCH TOTALS
POSSIBLE. WITH RECENT HEAVY RAIN OVER THE SOUTHERN HALF OF
OKLAHOMA AND NORTH TEXAS...FLOODING WILL AGAIN BE A CONCERN.
BRIEF SHORTWAVE RIDGING ON THURSDAY WILL KEEP RAIN CHANCES
LOW...BUT ANOTHER TROUGH WILL BEGIN TO SHIFT EASTWARD FRIDAY INTO
THE WEEKEND. BETTER INSTABILITY IS EXPECTED TO DEVELOP AHEAD OF
THIS SYSTEM WHICH WILL RESULT IN AN INCREASE IN SEVERE WEATHER
CHANCES FRIDAY INTO SATURDAY. ANOTHER FRONT IS EXPECTED TO PUSH
ACROSS THE SOUTHERN PLAINS SUNDAY INTO MONDAY WHICH WILL BRING
ANOTHER PERIOD OF DRY WEATHER.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 56 67 62 79 / 30 100 100 30
HOBART OK 56 67 61 80 / 40 100 70 20
WICHITA FALLS TX 59 70 64 82 / 60 100 70 30
GAGE OK 53 66 56 81 / 20 80 60 10
PONCA CITY OK 53 66 59 79 / 10 70 100 50
DURANT OK 59 71 64 80 / 40 80 70 50
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
OKZ007-008-012-013-017>020-022>048-050>052.
TX...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
TXZ083>090.
&&
$$
11/84
AREA FORECAST DISCUSSION...UPDATE
NWS PENDLETON OR
351 PM PDT TUE MAY 12 2015
UPDATED FOR AVIATION DISCUSSION
.SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY NIGHT. AN INTENSE AND
STATIONARY LOW PRESSURE SYSTEM OVER THE PACNW WILL CONTINUE TO PUMP
MOISTURE INTO OUR AREA AND COMBINING THIS WITH DAYTIME HEATING WILL
PRODUCE ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING. THE TSRA
COULD BECOME STRONG AND PRODUCE GUSTY WINDS AND HAIL WITH THE BEST
CHANCES OF THIS OCCURRING OVER THE EASTERN ZONES THAT INCLUDES IN
AND AROUND THE BLUE/WALLOWA MOUNTAINS AS WELL AS GRANT COUNTY.
ELSEWHERE SHOWERS WILL CONTINUE DEVELOPING ACROSS THE REGION INTO
THIS EVENING. AS THE LOW DRIFTS INTO NE OREGON LATER TONIGHT
MOISTURE WILL RAP AROUND THIS SYSTEM AND INTO THE EASTERN PORTIONS
OF THE AREA AND MODERATE TO HEAVY RAINFALL IS POSSIBLE WITH UP TO AN
INCH IN SOME LOCATIONS. THE LOW AND THE BULK OF THE MOISTURE DRIFT
NORTH WEDNESDAY MORNING WITH DECREASING CHANCES OF PCPN EXPECTED BUT
THE CLOUDS AND SHOWERS WILL PERSIST INTO WEDNESDAY AFTERNOON. A WEAK
DISTURBANCE WILL NEAR CENTRAL OREGON WEDNESDAY AFTERNOON THAT COULD
PRODUCE AN ISOLD TSRA. OTHERWISE THE BEST CHANCES FOR PCPN SHOULD
OCCUR ALONG THE WA/OR CASCADES WEDNESDAY NIGHT AND THURSDAY.
BY THURSDAY ANOTHER LOW PRESSURE SYSTEM WILL TRACK TO OUR SOUTH BUT
SHOWERS FROM THIS SYSTEM WILL MOVE NORTH AND INTO MOST PORTIONS OF
OUR AREA THURSDAY NIGHT. AFTERNOON TEMPERATURES WILL REMAIN COOL
TOMORROW BEFORE WARMER TEMPERATURES CAN BE EXPECTED THURSDAY.
&&
.LONG TERM...FRIDAY THROUGH MONDAY NIGHT...MILD YET UNSETTLED
WEATHER CAN BE EXPECTED FOR THE EXTENDED. A LOW PRESSURE SYSTEM
CENTERED OVER CENTRAL NEVADA WILL CONTINUE TO SPIN UP MOISTURE AND
POSSIBLE THUNDERSTORMS TO THE AREA ON FRIDAY. THIS SYSTEM WILL EXIT
THE AREA FRIDAY NIGHT WITH ANOTHER LOW MOVING TOWARDS THE PACIFIC
COAST ON SATURDAY. THIS LOW IS CURRENTLY FORECAST TO TRACK SOUTH OF
THE CWA TOWARDS THE NORTHERN CALIFORNIA COAST THROUGH THE WEEKEND.
THIS WILL ALLOW FOR MORE MOISTURE AND INSTABILITY TO BE SPUN UP OVER
THE AREA...PROVIDING ANOTHER CHANCE FOR THUNDERSTORMS. THE LOW IS
EXPECTED TO SLOWLY MOVE INLAND AND BE CENTERED OVER THE CA/NV
BOARDER ON MONDAY NIGHT. OVERALL THE AIRMASS SHOULD BE FAIRLY WARM
OVER THE AREA...KEEPING THE TEMPERATURES NEAR TO ABOVE NORMAL.
REASONABLE CLOUD COVER CAN BE EXPECTED AT NIGHT AS WELL...ALLOWING
FOR MILD NIGHTTIME LOWS. WEBER
&&
.AVIATION...00Z TAFS...MVFR CONDITIONS CAN BE EXPECTED OVER THE NEXT
12-18 HOURS...AS A DEFORMATION BAND IS EXPECTED TO SET UP OVER
SOUTHERN WASHINGTON DURING THIS PERIOD. THIS COULD ALLOW FOR
PERIODS OF MODERATE RAIN...WITH CIGS POSSIBLY FALLING TO IFR
CATEGORIES. FOR NOW PROB30 GROUPS COVER THE PERIODS OF CONCERN.
STILL POSSIBLE -TSRA AT KPDT AND KALW FROM 0Z-3Z THIS
AFTERNOON...BUT DUE TO LOWER CONFIDENCE HAVE REMOVED THE TEMPO GROUP
FOR THUNDER AND JUST LEFT SHOWERS. WINDS WILL RANGE FROM 5 TO 15
KTS...WITH GUSTS UP TO 25 KTS. WEBER
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 45 62 45 64 / 90 70 10 30
ALW 48 65 46 69 / 90 80 10 30
PSC 51 70 46 70 / 90 80 10 20
YKM 49 68 43 70 / 80 70 40 20
HRI 49 69 44 70 / 80 70 10 30
ELN 47 66 41 70 / 90 80 40 20
RDM 35 60 36 59 / 50 30 30 50
LGD 43 62 41 64 / 100 70 20 30
GCD 41 63 39 65 / 80 20 20 50
DLS 48 65 46 71 / 60 50 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97/89/89
AREA FORECAST DISCUSSION
NWS PENDLETON OR
225 PM PDT TUE MAY 12 2015
.SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY NIGHT. AN INTENSE AND
STATIONARY LOW PRESSURE SYSTEM OVER THE PACNW WILL CONTINUE TO PUMP
MOISTURE INTO OUR AREA AND COMBINING THIS WITH DAYTIME HEATING WILL
PRODUCE ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING. THE TSRA
COULD BECOME STRONG AND PRODUCE GUSTY WINDS AND HAIL WITH THE BEST
CHANCES OF THIS OCCURRING OVER THE EASTERN ZONES THAT INCLUDES IN
AND AROUND THE BLUE/WALLOWA MOUNTAINS AS WELL AS GRANT COUNTY.
ELSEWHERE SHOWERS WILL CONTINUE DEVELOPING ACROSS THE REGION INTO
THIS EVENING. AS THE LOW DRIFTS INTO NE OREGON LATER TONIGHT
MOISTURE WILL RAP AROUND THIS SYSTEM AND INTO THE EASTERN PORTIONS
OF THE AREA AND MODERATE TO HEAVY RAINFALL IS POSSIBLE WITH UP TO AN
INCH IN SOME LOCATIONS. THE LOW AND THE BULK OF THE MOISTURE DRIFT
NORTH WEDNESDAY MORNING WITH DECREASING CHANCES OF PCPN EXPECTED BUT
THE CLOUDS AND SHOWERS WILL PERSIST INTO WEDNESDAY AFTERNOON. A WEAK
DISTURBANCE WILL NEAR CENTRAL OREGON WEDNESDAY AFTERNOON THAT COULD
PRODUCE AN ISOLD TSRA. OTHERWISE THE BEST CHANCES FOR PCPN SHOULD
OCCUR ALONG THE WA/OR CASCADES WEDNESDAY NIGHT AND THURSDAY.
BY THURSDAY ANOTHER LOW PRESSURE SYSTEM WILL TRACK TO OUR SOUTH BUT
SHOWERS FROM THIS SYSTEM WILL MOVE NORTH AND INTO MOST PORTIONS OF
OUR AREA THURSDAY NIGHT. AFTERNOON TEMPERATURES WILL REMAIN COOL
TOMORROW BEFORE WARMER TEMPERATURES CAN BE EXPECTED THURSDAY.
&&
.LONG TERM...FRIDAY THROUGH MONDAY NIGHT...MILD YET UNSETTLED
WEATHER CAN BE EXPECTED FOR THE EXTENDED. A LOW PRESSURE SYSTEM
CENTERED OVER CENTRAL NEVADA WILL CONTINUE TO SPIN UP MOISTURE AND
POSSIBLE THUNDERSTORMS TO THE AREA ON FRIDAY. THIS SYSTEM WILL EXIT
THE AREA FRIDAY NIGHT WITH ANOTHER LOW MOVING TOWARDS THE PACIFIC
COAST ON SATURDAY. THIS LOW IS CURRENTLY FORECAST TO TRACK SOUTH OF
THE CWA TOWARDS THE NORTHERN CALIFORNIA COAST THROUGH THE WEEKEND.
THIS WILL ALLOW FOR MORE MOISTURE AND INSTABILITY TO BE SPUN UP OVER
THE AREA...PROVIDING ANOTHER CHANCE FOR THUNDERSTORMS. THE LOW IS
EXPECTED TO SLOWLY MOVE INLAND AND BE CENTERED OVER THE CA/NV
BOARDER ON MONDAY NIGHT. OVERALL THE AIRMASS SHOULD BE FAIRLY WARM
OVER THE AREA...KEEPING THE TEMPERATURES NEAR TO ABOVE NORMAL.
REASONABLE CLOUD COVER CAN BE EXPECTED AT NIGHT AS WELL...ALLOWING
FOR MILD NIGHTTIME LOWS. WEBER
&&
.AVIATION...PREVIOUS DISCUSSION...18Z TAFS...MVFR-VFR CONDITIONS
OVER THE NEXT 6 HOURS...WITH BETTER CHANCES OF MVFR CONDITIONS OVER
THE 0Z-12Z WEDNESDAY TIME PERIOD. DEFORMATION BAND EXPECTED TO SET
UP OVER SOUTHERN WASHINGTON DURING THIS PERIOD. THIS COULD ALLOW
FOR PERIODS OF MODERATE RAIN...WITH CIGS POSSIBLY FALLING TO IFR
CATEGORIES. FOR NOW PROB30 GROUPS COVER THE PERIODS OF CONCERN.
POSSIBLE -TSRA AT KPDT AND KALW FROM 0Z-3Z THIS AFTERNOON. HAVE
ADDED A TEMPO GROUP TO COVER THE THUNDER. WINDS WILL RANGE FROM 5
TO 15 KTS...WITH GUSTS UP TO 25 KTS. WEBER
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 45 62 45 64 / 90 70 10 30
ALW 48 65 46 69 / 90 80 10 30
PSC 51 70 46 70 / 90 80 10 20
YKM 49 68 43 70 / 80 70 40 20
HRI 49 69 44 70 / 80 70 10 30
ELN 47 66 41 70 / 90 80 40 20
RDM 35 60 36 59 / 50 30 30 50
LGD 43 62 41 64 / 100 70 20 30
GCD 41 63 39 65 / 80 20 20 50
DLS 48 65 46 71 / 60 50 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97/89/89
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
136 PM EDT TUE MAY 12 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS OUR AREA TODAY...BEFORE STRONG HIGH
PRESSURE BUILDS IN FROM THE NORTH AND REMAINS THROUGH FRIDAY.
MOISTURE WILL SPREAD OVER THE AREA AHEAD OF ANOTHER COLD FRONT THAT
APPROACHES FROM THE WEST EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 130 PM EDT...RADAR HAS BEEN RELATIVELY QUIET EARLY THIS
AFTERNOON AS A COLD FRONT SLIPS SLOWLY EASTWARD ACROSS THE REGION.
HOWEVER...THE HRRR CONTINUES TO INSIST ON SCATTERED CONVECTIVE
DEVELOPMENT ALONG THE PASSING COLD FRONT...WITH PEAK PIEDMONT
COVERAGE CIRCA 19Z TO 20Z. THIS IS SOMEWHAT CONSISTENT WITH SB CAPE
VALUES OF 1000 TO 1500 J/KG OR GREATER OVER THE ERN PIEDMONT PARTS
OF OUR FORECAST AREA...AND ALSO WITH MODEL PROFILES FINALLY
OVERCOMING LOW LEVEL CINH AROUND THAT TIME. HOWEVER...THE MID DECK
OF CLOUDS HAS GREATLY LIMITED HEATING FOR MUCH OF THE AREA...SO
EXPECT THAT ANY ISOLD TO SCT CONVECTION THAT DOES FORM WILL BE
RATHER WEAK.
OTHERWISE...THE SFC COLD FRONT WILL SETTLE SOUTHEAST OF THE AREA
THIS EVENING WITH DRIER HIGH PRESSURE BUILDING OVER TO THE N THROUGH
WED. WEAK CHANNELED VORTICITY WILL SLIDE EAST ACROSS THE AREA
OVERNIGHT TO PRODUCE SOME HIGH LEVEL CLOUDINESS...BUT WITH LOWER
LEVELS DRY. EXPECT MINS TO FALL INTO THE 40S MTNS AND 50S PIEDMONT
UNDER WEAK COLD ADVECTION. HEIGHT RISES WILL DEVELOP FROM THE WEST
ON WED WITH COMFORTABLE MAXES NEAR CLIMO.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AT 300 AM EDT TUESDAY...ON WEDNESDAY MORNING AN UPPER TROUGH WILL BE
ALONG THE EAST COAST...WHILE AND UPPER RIDGE WILL EXTEND FROM THE
GULF STATES TO THE NORTHERN PLAINS. BY THURSDAY THIS NEGATIVELY
TILTED RIDGE WILL EXTEND FROM FL TO THE UPPER MS RIVER VALLEY. A
STRONG SHORTWAVE WILL ACROSS THE MS RIVER VALLEY ON THURSDAY...
WEAKENING AS IT MOVES THROUGH THE RIDGE AXIS ON THURSDAY NIGHT.
AT THE SURFACE...ON WEDNESDAY DRY HIGH PRESSURE CENTERED OVER THE
GREAT LAKES WILL BUILD SOUTH ACROSS OUR AREA IN THE WAKE OF A
DEPARTING COLD FRONT. AS THE HIGH MOVES EAST ON THURSDAY...IT
EXTENDS SOUTH ALONG THE EAST SLOPES OF THE APPALACHIANS. ON
THURSDAY NIGHT...ISENTROPIC UPGLIDE OVER THE HIGH SETS THE STAGE FOR
PRECIPITATION...MAINLY OVER THE MOUNTAINS. TEMPERATURES WILL START
OUT SLIGHTLY ABOVE NORMAL IN DOWNSLOPE WARMING BEHIND THE
FRONT...FALLING TO NEAR NORMAL AS THE COOLER AIR MASS ARRIVES AND
LOW LEVEL FLOW VEERS TO NE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AT 135 PM EDT TUESDAY...HIGH CONFIDENCE IS HAD THROUGHOUT THE EXT
PERIOD. GOOD INDIVIDUAL RUN TO RUN AND MODEL TO MODEL CONSISTENCY
CONTINUES TO INDICATE A BUILDING H5 RIDGE SAT BECOMING REINFORCED ON
SUN...THEN SLOWLY BREAKING DOWN MON THROUGH TUE. THERE ARE SOME
SUBTLE DIFFERENCES IN IN THE MAGNITUDE AND LOCATION OF THE RIDGE
AXIS...HOWEVER NOT ENOUGH DIFFERENCES TO IMPACT THE SENSIBLE WX
SIGFNTLY.
AT THE SFC...THE MAIN SYNOPTIC FEATURE WILL BE A MID ATL HIGH
MERGING WITH THE BERMUDA HIGH CREATING A DOMINATE RIDGING PATTERN
ACROSS THE CWFA THROUGH MOST OF THE PERIOD. THIS SETUP WILL KEEP THE
MAIN STORM ACTIVITY AND HIGHER DEEP LAYERED INSTABILITY WEST OF THE
AREA SAT AND SUN...WITH ISOL/SCT PULSE MTN TSTMS PROBABLE EACH
AFTERNOON. THE SFC RIDGE WEAKENS ON MON WHICH WILL ALLOW HIGHER TD/S
NORTH AND INCREASE SBCAPE VALUES...ENUF SO FOR MENTION OF DIURNAL
THUNDER ACROSS ALL ZONES. WITH LIMITED ULVL ENERGY...THE ATMOS WILL
BE IN A TYPICAL SUMMERTIME PATTERN WITH SCT PULSE SEVERE STORMS
POSSIBLE EACH AFTERNOON MON/TUE. WITH CONTINUED RIDGING AND SW/LY
LLVL FLOW...MAX TEMPS WILL BEGIN RIGHT AROUND NORMAL SAT AND
INCREASE TO A COUPLE CATS ABOVE NORMAL BY TUE.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT...MID CLOUDS THROUGH MIDDAY HAVE LIMITED HEATING AND
INSTABILITY. WILL THUS CONTINUE TO FEATURE ONLY VCSH WITH THE FROPA
THIS AFTN. OTHERWISE...EXPECT WSW WINDS TO TOGGLE NW WITH FROPA
TOWARD EVENING AND THEN TURN NRLY AND NE OVERNIGHT INTO WED MORNING.
ANY CIGS SHOULD BE MID AND HIGH CLOUDS...WITH HIGHER CLOUDS THINNING
LATER IN THE PERIOD.
ELSEWHERE...MORNING MID CLOUDS HAVE LIMITED INSTABILITY...WHICH
SHOULD KEEP FOOTHILL TAFS DRY THIS AFTN. THE FROPA IS THROUGH
KAVL...SO DRY AND VFR CONDITIONS WILL CONTINUE THERE AS WELL...WITH
OCNL NW GUSTS. FOOTHILL WINDS WILL TOGGLE NW THROUGH LATE AFTN AND
NRLY THEN NE OVERNIGHT THROUGH WED MORNING. LITTLE MORE THAN HIGH
CLOUDS ARE THEN EXPECTED THE LATER HALF OF THE PERIOD.
OUTLOOK...DRIER AIR WILL SETTLE IN UNDER BUILDING HIGH PRESSURE
THROUGH THU. RETURN FLOW MOISTURE AROUND THE HIGH PRESSURE MAY ALLOW
DIURNAL SHOWERS AND THUNDERSTORMS TO RETURN TO THE AREA FRIDAY
THROUGH THE WEEKEND...ESPECIALLY OVER THE MTNS.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...HG
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...HG
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1112 AM MDT TUE MAY 12 2015
.UPDATE...
ISSUED AT 938 AM MDT TUE MAY 12 2015
15Z SURFACE ANALYSIS HAD FRONTAL BOUNDARY FROM NORTHWEST WY INTO
SOUTHWEST SD. LIFT UNDER RIGHT ENTRANCE REGION OF JET STREAK
ACROSS THE NORTHERN PLAINS ASSISTING SOME WEAKER RETURNS ON RADAR
ACROSS FAR NORTHEAST WY/SOUTHEAST MT/ENTERING NORTHWEST SD. MOST
OF IT NOT REACHING THE GROUND...AND LOOKING AT THE 12Z KUNR
SOUNDING THERE IS SOME DRY AIR TO OVERCOME.
12Z RAP SHOWS A BIT OF SBCAPE OVER THE HIGHER TERRAIN AS DECENT
SOUTHERLY FLOW FEEDS MOISTURE POOLING ALONG THE BOUNDARY SO HAVE
ADDED SMALL POPS LATER THIS AFTERNOON FOR THOSE AREAS.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 300 AM MDT TUE MAY 12 2015
WESTERN CONUS UPPER LEVEL TROUGHING ONGOING THIS MORNING WITH A
LOCAL WAA RESPONSE. WEAK LEAD IMPULSE FROM THIS SYSTEM WILL
SUPPORT INCREASING MID/HIGH CLOUDS THROUGH MORNING ACROSS THE
NORTHERN HALF...WITH A FEW SPRINKLES POSSIBLE ACROSS THE FAR
NORTH. MEANWHILE ANOTHER UPPER LEVEL IMPULSE WILL SHIFT NE INTO
THE SW CONUS AND SOUTHERN PLAINS. THIS SYSTEM WILL HELP SUPPORT
DEEPER MOISTURE NORTH INTO THE AREA THROUGH TONIGHT. ONGOING
PRESSURE FALLS PER THE ADVANCING WESTERN CONUS UPPER TROUGH WILL
SUPPORT A LLJ TONIGHT WITH SOME FORCING FOR ASCENT PER A SLOW
MOVING NW CONUS UPPER TROUGH GRAZING THE NORTHERN PLAINS TONIGHT.
STEEP MID LEVEL LAPSE RATE WITH AN FGEN RESPONSE AND INCREASING
ELEVATED INSTABILITY NOTED IN MU CAPES WILL SUPPORT A SLIGHT
CHANCE SHOWER/TS THREAT ACROSS THE NORTHERN HALF TONIGHT. HIRES
MODELS INCLUDING THE NAM SUGGEST AN ISOLD HIGH BASED SHRA/TS COULD
DEVELOP OVER NE WY THIS EVENING AS CIN IS MINIMIZED PER
INSOLATION...WITH ANY ACTIVITY BEING CARRIED NE BY A DEVELOPING
LLJ. DID ADJUST SLIGHT CHANCE POPS SW INTO NE WY AND THE BH AFTER
00Z THIS EVENING FOR THIS...WITH A SLIGHTLY EARLIER START TIME
POSSIBLE. LEE SIDE TROUGH WILL SHIFT EAST ACROSS THE FA WED
MORNING AND STALL WITH THE SOUTHERN PLAINS IMPULSE SHIFTING NORTH.
RENEWED FGEN FROM THIS SYSTEM WILL SUPPORT INCREASING LL
CONVERGENCE ALONG AND NEAR THE SFC TROUGH WHICH WILL BE SOMEWHERE
ACROSS THE EASTERN FA. INCREASING LL MOISTURE COMBINED WITH
DIURNAL INSTABILITY WILL ALLOW INCREASING CHANCES FOR SHRA/TS
THERE...WITH OTHER ACTIVITY POSSIBLE OVER THE BH AND NE WY PER
DIURNAL HEATING IN THE PRESENCE OF UNSTABLE PROFILES/WEAK CIN.
SHRA/TS CHANCES SHOULD INCREASE WED NIGHT AS THE LLJ SUSTAINED
WITH ONGOING MOISTURE TRANSPORT AND INCREASING LSA FROM THE
EXPECTED IMPULSE. BULK OF FORCING FROM THIS SYSTEM WILL REMAIN SE
OF THE FA...INCLUDING THE ASSOCIATED PRECIP CHANCES. HAVE RETAINED
HIGH CHANCE POPS...PRECLUDING LIKELY ATTM GIVEN CONVECTIVE
COMPONENT TO PRECIP.
AS FOR TEMPS...BUMPED HIGHS UP BOTH TODAY AND WED. SNOW PACK HAS
ERODED QUITE WELL OVER MUCH OF THE AREA...WITH THE DEEPEST SNOW
REMAINING OVER SW SD. STRONG SE WINDS UNDER MAY SUN SHOULD MIX
WARMER AIR DOWN WITH NO PROBLEM...THUS HAVE OPTED FOR TEMPS MORE
IN LINE WITH GUIDANCE.
.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 300 AM MDT TUE MAY 12 2015
THE UPPER LEVEL RIDGE WILL MOVE EAST OF THE AREA ON WEDNESDAY.
THIS WILL PUT THE AREA IN ACTIVE SOUTHWEST FLOW FOR MID WEEK INTO
THE WEEKEND...WITH DAILY CHANCES FOR RAIN SHOWERS AND SOME
THUNDERSTORMS. A FAST-MOVING SHORTWAVE WILL SWEEP THROUGH THE
CENTRAL CONUS WEDNESDAY NIGHT AND THURSDAY...AND THEN ANOTHER
UPPER LOW IS PROGGED TO MOVE ACROSS THE ROCKIES AND INTO THE
PLAINS THIS WEEKEND...BRINGING THE BEST CHANCES FOR ADDITIONAL
RAINFALL. MODELS ARE INDICATING AROUND A HALF INCH OF QPF BY THE
END OF THE WEEK...WITH AN ADDITIONAL INCH OR TWO DURING THE
WEEKEND. AS FAR AS TEMPERATURES GO...MORE SPRING LIKE READINGS ARE
EXPECTED FROM MID WEEK THROUGH THE WEEKEND. THEREFORE...THE
PRECIPITATION SHOULD REMAIN RAIN.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY
ISSUED AT 1110 AM MDT TUE MAY 12 2015
GUSTY SOUTHERLY WINDS ACROSS SOUTH CENTRAL SD WILL DIMINISH THIS
EVENING. NORTHWEST SD INTO NORTHEAST WY AND THE BLACK HILLS HAVE A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS THIS EVENING AND
OVERNIGHT. GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH WEDNESDAY
MORNING...ALTHOUGH THERE MAY BE SOME LOCAL MFVR CIGS WITH ANY
SHOWERS AND THUNDERSTORMS. MODELS ARE IN DISAGREEMENT ON THE
POSSIBLE DEVELOPMENT OF FOG ACROSS NORTHEAST WY AND AREAS JUST
EAST OF THE BH. COULD BE SOME LOW STRATUS...BUT WILL KEEP TAFS VFR
FOR NOW.
&&
.HYDROLOGY...
ISSUED AT 300 AM MDT TUE MAY 12 2015
RUNOFF FROM RAIN AND MELTING SNOW IS CAUSING RAPID RISES IN THE
LEVEL OF THE WHITE RIVER BETWEEN INTERIOR AND OACOMA. A FLOOD
WARNING HAS BEEN ISSUED FOR THAT AREA AS MINOR TO MODERATE
FLOODING IS FORECAST TO DEVELOP STARTING TUESDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...HELGESON
SHORT TERM...JC
LONG TERM...7
AVIATION...POJORLIE
HYDROLOGY...JC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 PM CDT TUE MAY 12 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 325 PM CDT TUE MAY 12 2015
FORECAST CONCERNS INCLUDE TEMPERATURES/FROST HEADLINES TONIGHT
AND THEN PRECIP/THUNDERSTORM CHANCES THROUGH EARLY NEXT WEEK.
DESPITE SOME MODEL TIMING DIFFERENCES FOR THURSDAY/S SYSTEM...
12.12Z MODEL SUITE IN GOOD OVERALL AGREEMENT THROUGH THURSDAY...
BUT THEN DIVERGE ON THE CONVECTIVE DETAILS FRIDAY INTO THE
WEEKEND. WILL USE A BLENDED MODEL APPROACH.
FOR TONIGHT...SURFACE RIDGE AXIS WILL SLIDE ACROSS THE UPPER MS
RIVER VALLEY...CENTERED ACROSS THE MN ARROWHEAD INTO NORTH-CENTRAL
WI BY 12Z WEDNESDAY. SHOULD SEE SOME INCREASING SOUTHEASTERLY
RETURN FLOW ACROSS SOUTHEAST MN AND NORTHEAST IA BY WEDNESDAY
MORNING...BUT FOR AREAS EAST OF THE MS RIVER...A WEAK PRESSURE
GRADIENT WILL LEAD TO CALM WINDS THROUGH THE NIGHT. IN ADDITION...
SIMULATED IR IMAGERY FROM THE NSSL WRF SUGGESTS CURRENT CU WILL
DISSIPATE AFTER SUNSET AND CIRRUS ACROSS THE DAKOTAS INTO CENTRAL
MN SHOULD REMAIN JUST WEST OF THE FORECAST AREA. AS A RESULT...
EXPECT MOSTLY CLEAR SKIES OVERNIGHT ALLOWING FOR MAXIMUM NOCTURNAL
COOLING. WILL HOIST A FROST ADVISORY FOR ALL WI COUNTIES EXCEPT
FOR BUFFALO/CRAWFORD/GRANT FROM MIDNIGHT THROUGH 7 AM WEDNESDAY
WHERE OVERNIGHT TEMPERATURES WILL FALL INTO THE UPPER 20S TO
MID 30S.
WARM AIR ADVECTION TO INCREASE ON WEDNESDAY ALLOWING TEMPERATURES
TO REBOUND BACK INTO THE UPPER 50S TO LOWER 60S. SOUTHEAST WINDS
TO INCREASE BETWEEN 10 AND 20 MPH AS SURFACE PRESSURE GRADIENT
STRENGTHENS ACROSS THE REGION. SHOULD SEE A FAIR AMOUNT OF SUN AS
CLOUDS/PRECIP WILL BE ANCHORED TO PRIMARY WARM FRONTAL BOUNDARY
FARTHER NORTH AND WEST ACROSS THE DAKOTAS INTO NORTHERN MN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE MAY 12 2015
RAIN SHOWERS TO INCREASE FROM WEST TO EAST THURSDAY AND THURSDAY
NIGHT AS A SHORT-WAVE EJECTS INTO THE UPPER MIDWEST FROM A BROADER
PACIFIC TROUGH PARKED ALONG THE WEST COAST. FRONTOGENESIS IS
RATHER WEAK WITH THIS SYSTEM...BUT MODEST WARM AIR ADVECTION/
ISENTROPIC LIFT COMBINED WITH INCREASING MOISTURE TRANSPORT WILL
RESULT IN A SWATH OF SHOWERS MOVING ACROSS THE REGION. PWATS RISE
ABOVE ONE INCH...RESULTING IN WIDESPREAD ACCUMULATIONS OF AT LEAST
A HALF INCH AND POSSIBLY AN INCH OR HIGHER IN SOME PLACES. THUNDER
WILL NOT ACCOMPANY THIS SYSTEM AS INSTABILITY IS NEARLY NON-
EXISTENT. CLOUDS/RAIN WILL KEEP THURSDAY COOL WITH AFTERNOON HIGHS
ONLY IN THE UPPER 50S TO LOWER 60S.
CONVECTIVE POTENTIAL A BIT MURKY FRIDAY INTO SATURDAY. BEST
MOISTURE TRANSPORT FOCUSES ITSELF EITHER EAST OR WEST OF THE
FORECAST AREA AND WITH LITTLE UPPER LEVEL DYNAMIC SUPPORT GIVEN
STRENGTHENING RIDGE...THUNDERSTORM POTENTIAL IS UNCERTAIN. BEST
CHANCE WOULD BE SATURDAY WITH NORTHWARD SURGING WARM FRONT. FOR
NOW...WILL FOLLOW SUPERBLEND 20 TO 30 PERCENT CHANCES. OF GREATER
CERTAINTY WILL BE INCREASING TEMPERATURES WITH HIGHS IN THE 60S TO
LOWER 70S ON FRIDAY RISING INTO THE MID TO UPPER 70S FOR SATURDAY.
BETTER CHANCE FOR MORE ORGANIZED THUNDERSTORMS ON SUNDAY WITH
APPROACHING PACIFIC TROUGH AND COLD FRONT. MUCAPE AND BULK SHEAR
WITHIN THE 0 TO 6 KM LAYER INCREASE TO BETWEEN 1000 AND 1500 J/KG
AND 35 TO 40 KTS RESPECTIVELY...BUT ONGOING CONVECTION EARLIER IN
THE DAY COULD IMPACT AFTERNOON/EVENING THUNDERSTORM/SEVERE POTENTIAL.
THIS IS HIGHLIGHTED IN THE DAY 6 SPC OUTLOOK AND SOMETHING TO
WATCH THROUGH THE WEEK. DRIER/COOLER CONDITIONS RETURN MONDAY/
TUESDAY AFTER COLD FRONTAL PASSAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1201 PM CDT TUE MAY 12 2015
LOW LEVEL CYCLONIC FLOW AROUND THE SYSTEM EXITING THE NORTHERN
GREAT LAKES CONTINUES TO PRODUCE CLOUDS AND FEW SHOWERS ACROSS THE
AREA. FOR THE MOST PART...THE SHOWERS HAVE MOVED EAST OF BOTH TAF
SITES AND DO NOT ANTICIPATE THESE BEING A PROBLEM FOR THE
REMAINDER OF THE AFTERNOON. VISIBLE SATELLITE TRENDS SHOW THE
WESTERN PORTION OF THE CLOUD DECK IS BECOMING MORE OPEN CELLULAR
SUGGESTING THESE CLOUDS WILL DISSIPATE AT SOME POINT THIS
AFTERNOON. BOTH THE 12.15Z RAP AND 12.12Z NAM SUGGEST THE LOW
LEVEL MOISTURE FIELD WILL CONTINUE TO SLIDE EAST WITH THE
DEPARTING SYSTEM WITH THE CLOUDS SCATTERING OUT BY MID AFTERNOON.
UNTIL THIS HAPPENS...THE CEILINGS WILL FLUCTUATE BETWEEN MVFR AND
VFR. THESE LOWER CLOUDS WILL TOTALLY DISSIPATE WITH SUNSET THIS
EVENING AND THE WINDS WILL DIMINISH AS HIGH PRESSURE BUILDS IN.
THIS HIGH WILL QUICKLY SLIP EAST OF THE AREA WEDNESDAY MORNING
ALLOWING THE WINDS TO BECOME EAST AND INCREASE TO AROUND 10 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM CDT WEDNESDAY FOR
WIZ017-029-033-034-041>044-053-055.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1201 PM CDT TUE MAY 12 2015
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 334 AM CDT TUE MAY 12 2015
DEPARTING SHOWERS THIS MORNING/FROST POTENTIAL TONIGHT ARE THE MAIN
CONCERNS IN THE SHORT TERM.
CURRENT MAP ANALYSIS HAS DEEP 1002MB LOW JUST EAST OF LAKE SUPERIOR.
MEANWHILE...WATER VAPOR IMAGERY SHOWS A CLOSED LOW OVER NORTHEAST MN
WITH EMBEDDED SHORTWAVE TROUGH ENERGY ROTATING EASTWARD ACROSS
SOUTHERN MN/WESTERN WI. RADAR MOSAIC/SURFACE OBS INDICATING
SCATTERED SHOWER/DRIZZLE ACTIVITY MAINLY ALONG AND EAST OF THE
MISSISSIPPI BEING FORCED BY THESE EMBEDDED TROUGHS. OTHERWISE...
TEMPERATURES ACROSS THE AREA WERE IN THE 40S WITH SOMEWHAT
BRISK WESTERLY WINDS OF 10-20 MPH.
FOR TODAY...THE SURFACE/CLOSED MID-LEVEL LOW WILL SLOWLY PUSH
NORTHEAST OF THE AREA THIS MORNING WITH A RIDGE OF HIGH PRESSURE
BUILDING IN FROM THE WEST DURING THE AFTERNOON. KEPT SCATTERED
SHOWER MENTION IN FOR AREAS ALONG/N OF THE I-90/94 CORRIDORS THROUGH
THE MORNING HOURS...BUT THEN IT SHOULD BE DRY THROUGH THE AFTERNOON
WITH A SLOW EROSION OF CLOUD COVER FROM SOUTHWEST TO NORTHEAST AS
WELL. PLAN ON COOLER THAN NORMAL TEMPERATURES TODAY AS HIGHS ONLY
MAKE IT INTO THE UPPER 40S TO THE MIDDLE 50S. THESE COOLER
TEMPERATURES AND BRISK NORTHWEST WINDS WILL GIVE AN OVERALL RAW FEEL
TO THE DAY.
HIGH PRESSURE BUILDS INTO THE AREA TONIGHT FOR PARTLY CLOUDY SKIES
AND LIGHT WINDS. THIS WILL LEAD TO SOME CHILLY OVERNIGHT LOWS AS
READINGS DIP INTO THE 30S. WITH TEMPERATURES NEARING THE FREEZING
MARK...FEEL THE SAND COUNTRY OF CENTRAL WI WOULD BE MOST SUSCEPTIBLE
FOR FROST. HOWEVER...THERE IS SOME INDICATION OF HIGH/MID CLOUD
STREAMING IN FROM UPSTREAM WARM AIR ADVECTION ACROSS THE DAKOTAS/MN.
IN ADDITION...APPEARS THE RIDGE AXIS ACTUALLY PASSES INTO EASTERN WI
AFTER MIDNIGHT WHICH MAY BE ENOUGH TO PRODUCE SOME LIGHT EAST WIND
TO KEEP LOWER BOUNDARY LAYER MIXED ENOUGH TO PREVENT WIDESPREAD
FROST. BASED ON THESE UNCERTAINTIES...HAVE HELD OFF ON FROST
HEADLINES FOR NOW AND WILL LET THE DAYSHIFT ASSESS WITH MORE INPUT
FROM 12Z MODEL RUNS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 334 AM CDT TUE MAY 12 2015
PLAN SOME INCREASE IN MID/HIGH CLOUD ON WEDNESDAY IN RESPONSE TO
WARM FRONT PUSHING NORTH THROUGH MN. HOWEVER...DRY LOWER LAYERS
THANKS TO SURFACE HIGH PRESSURE OVER THE GREAT LAKES IS EXPECTED TO
KEEP THE AREA PRECIPITATION-FREE. PLAN ON HIGHS IN THE UPPER 50S TO
THE MIDDLE 60S WHICH IS STILL SOME 5 DEGREES BELOW NORMAL.
FOR LATER WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...WILL BE WATCHING
A MID-LEVEL TROUGH MOVE FROM THE CENTRAL PLAINS INTO THE UPPER
MISSISSIPPI RIVER VALLEY REGION. FORCING FROM THIS WAVE AND AMPLE
850MB MOISTURE TRANSPORT ENOUGH TO DRIVE THE LIKELIHOOD OF SHOWERS.
VERY LIMITED/NIL CAPE SHOULD PREVENT ANY THUNDER POTENTIAL. AS SUCH
REMOVED ANY THUNDER MENTION. WITH CLOUD COVER/PRECIPITATION...
TEMPERATURES WILL SUFFER A BIT ON THURSDAY AS HIGHS ONLY TOP OFF IN
THE UPPER 50S TO THE LOWER 60S.
SOME LINGERING SHOWERS STILL POSSIBLE MAINLY FRIDAY MORNING AS THE
WAVE DEPARTS THE AREA. WITH BULK OF THIS SHOWER CHANCE IN THE
MORNING...APPEARS RIDGE OF HIGH PRESSURE AND INCREASING HEIGHTS WILL
RESULT IN HIGH TEMPERATURES WELL INTO THE 60S.
AFTER A DRY/PLEASANT SATURDAY WITH HIGHS LOOKING TO PUSH INTO THE
70S...ACTIVE WEATHER PATTERN SETTING UP FOR THE REST OF THE WEEKEND
INTO MONDAY. INCREASING SHOWERS AND THUNDERSTORM CHANCES WILL
OVERSPREAD THE AREA...MAINLY CENTERED ON SUNDAY AS A POTENT LOW
PRESSURE SYSTEM PUSHES TOWARD THE UPPER MISSISSIPPI RIVER VALLEY
REGION. APPEARS TO BE AMPLE BULK SHEAR...WITH GFS INDICATING 0-3KM
MUCAPE IN THE 500-1000J/KG RANGE SUNDAY AFTERNOON. BASED ON
THIS...THE POSSIBILITY IS THERE FOR A FEW SEVERE STORMS.
HOWEVER...UNCERTAINTY REMAINS GIVEN LIKELIHOOD OF ONGOING/MUDDLED
CONVECTION THROUGH THE DAY ON SUNDAY. WILL BE KEEPING A CLOSE EYE ON
THIS SITUATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1201 PM CDT TUE MAY 12 2015
LOW LEVEL CYCLONIC FLOW AROUND THE SYSTEM EXITING THE NORTHERN
GREAT LAKES CONTINUES TO PRODUCE CLOUDS AND FEW SHOWERS ACROSS THE
AREA. FOR THE MOST PART...THE SHOWERS HAVE MOVED EAST OF BOTH TAF
SITES AND DO NOT ANTICIPATE THESE BEING A PROBLEM FOR THE
REMAINDER OF THE AFTERNOON. VISIBLE SATELLITE TRENDS SHOW THE
WESTERN PORTION OF THE CLOUD DECK IS BECOMING MORE OPEN CELLULAR
SUGGESTING THESE CLOUDS WILL DISSIPATE AT SOME POINT THIS
AFTERNOON. BOTH THE 12.15Z RAP AND 12.12Z NAM SUGGEST THE LOW
LEVEL MOISTURE FIELD WILL CONTINUE TO SLIDE EAST WITH THE
DEPARTING SYSTEM WITH THE CLOUDS SCATTERING OUT BY MID AFTERNOON.
UNTIL THIS HAPPENS...THE CEILINGS WILL FLUCTUATE BETWEEN MVFR AND
VFR. THESE LOWER CLOUDS WILL TOTALLY DISSIPATE WITH SUNSET THIS
EVENING AND THE WINDS WILL DIMINISH AS HIGH PRESSURE BUILDS IN.
THIS HIGH WILL QUICKLY SLIP EAST OF THE AREA WEDNESDAY MORNING
ALLOWING THE WINDS TO BECOME EAST AND INCREASE TO AROUND 10 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04