Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/26/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
125 PM MST WED JUL 24 2013
.SYNOPSIS...AN IMPULSE FROM THE EAST WILL ENHANCE THUNDERSTORM
COVERAGE AND INTENSITY ACROSS MOST OF THE AREA INTO THURSDAY. SOME
STORMS WILL GENERATE HEAVY RAINFALL. OTHERWISE...PLENTY OF MOISTURE
TO PROVIDE A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS INTO THE WEEKEND.
&&
.DISCUSSION...VIS SATELLITE DATA SHOWS CLEARING ACROSS MUCH OF
GRAHAM AND GREENLEE COUNTIES WITH SOME CU DEVELOPMENT OVER THE HIGH
TERRAIN IN COCHISE AND SOUTHWEST GRAHAM COUNTIES. SEVERAL VALLEY
LOCATIONS ACROSS THE EASTERN COUNTIES ARE IN THE UPPER 80S TO LOW 90
RANGE...WHEREAS WESTERN PIMA AND SANTA CRUZ COUNTIES ARE LARGELY
CLOUDED OVER WITH RELATIVELY COOL CONDITIONS IN PLACE. THE BETTER
HEATING IN THE EAST STILL SUGGESTS A THREAT FOR CONVECTION THROUGH
THE AFTERNOON AND EVENING. HOWEVER...THE CLOUDY COOLER COOLER
CONDITIONS ELSEWHERE COMBINED WITH A WARM LAYER AT AROUND 450 TO 500
MB SHOULD KEEP STRONG CONVECTION LIMITED OVER PIMA/SANTA CRUZ AREAS.
THE 18Z HRRR RUN HAD THE BEST HANDLE ON THE CLOUD COVER SO FAR AND
KEEPS ACTIVITY RELATIVELY LIMITED THROUGH THE REST OF THE AFTERNOON.
HOWEVER...THERE ARE SIGNS OF INCREASING ACTIVITY OVERNIGHT IN THE
FORM OF AN MCS DEVELOPING OVER WESTERN NEW MEXICO AND DRIFTING
SOUTHWEST ACROSS AZ. GIVEN THE OUR WEAK LOW PRESSURE SYSTEM IS STILL
HANGING AROUND SE ARIZONA SO THIS WOULD MAKE OVERNIGHT CONVECTION A
REASONABLE SOLUTION. GIVEN THE SATURATED GROUND CONDITIONS IN THE
EASTERN ZONES...THE FLASH FLOOD WATCH STILL APPEARS WARRANTED. WE
ARE ALSO CLOSELY MONITORING THE SAN FRANCISCO AND GILA RIVERS ACROSS
GRAHAM AND GREENLEE COUNTIES. THERE ARE QUICK RESPONSE CHANNELS IN
OUR CWA AND IT WILL NOT TAKE MUCH RAINFALL IN THAT AREA TO CAUSE
RAPID RISES.
THE TROUGH AXIS OF THE WEAK UPPER LOW LAYS OVER SE ARIZONA TOMORROW
AS WELL AND MAY AGAIN SERVE AS A SOURCE OF LIFT FOR ACTIVITY. MODELS
ARE SUGGESTING ANOTHER WET DAY POSSIBLE TOMORROW WITH THE FOCUS
MAINLY ALONG THE INTERNATIONAL BORDER AND HIGHER TERRAIN. WE SHOULD
ALSO SEE A RETURN OF SOUTHERLY FLOW ALOFT TOMORROW ALONG WITH
SUSTAINED MID LEVEL MOISTURE.
THE MONSOON RIDGE BEGIN A MODIFICATION PROCESS TOMORROW AS WELL.
INITIALLY...THE RIDGE AXIS AMPLIFIES OVER THE WESTERN US THROUGH
FRIDAY...KEEPING SE ARIZONA IN FAVORABLE FLOW FOR THUNDERSTORMS.
HOWEVER...STARTING LATE SATURDAY...THE RIDGE BEGINS THE FLATTEN AND
SHIFT SOUTHEAST. THE FLOW ALOFT OVER ARIZONA BECOME MORE WESTERLY
AND STAYS WESTERLY THROUGH MONDAY. THE HIGH CONTINUES DRIFTING SOUTH
THROUGH MIDWEEK AND WHILE OUR FLOW ALOFT BACKS TO THE SOUTH...WE
REMAIN FAIRLY DRY INT THE MIDLEVELS. SO WE MAY HAVE A DECENT BREAK
IN THUNDERSTORM ACTIVITY STARTING SUNDAY AND LASTING FOR SEVERAL
DAYS. THAT MEANS WARMER TEMPERATURES TOO. GFS/ECWMF DID SHOW ANOTHER
INVERTED TROUGH MOVING WEST ACROSS NORTHERN MEXICO MID WEEK BUT THEY
KEEP THE ENERGY FAR ENOUGH SOUTH THAT PRECIP CHANCES WOULD BE
LIMITED OVER ARIZONA.
JJB
&&
.AVIATION... SCT TO NUMEROUS TSRA /SHRA CONTINUING THRU
25/06Z...THEN BECOMING MAINLY ISOLD. MVFR CONDITIONS WITH WIND GUSTS
APPROACHING 45 KTS WITH THE STRONGEST TSRA. OTHERWISE...CLOUD DECKS
MAINLY 6-12K FT AGL AND SURFACE WIND GENERALLY LESS THAN 10 KTS THRU
THURSDAY MORNING OR 25/18Z. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...ENHANCED MOISTURE WILL PROVIDE A BETTER CHANCE OF
SHOWERS AND THUNDERSTORMS THROUGH THURSDAY EVENING.
OTHERWISE...SOUTHEAST ARIZONA WILL KEEP ENOUGH MOISTURE AROUND FOR
MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS TO CONTINUE
INTO EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH FROM 11AM
UNTIL 9 PM MST FOR AZZ507>514.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
953 PM MST TUE JUL 23 2013
.SYNOPSIS...
MONSOON MOISTURE AND HUMID CONDITIONS WILL CONTINUE ACROSS THE
REGION THROUGH THE WEEKEND...HOWEVER THE BEST CHANCE OF AFTERNOON
AND EVENING THUNDERSTORMS WILL BE OVER THE MOUNTAINS OF NORTHERN AND
EASTERN ARIZONA. NEAR NORMAL TEMPERATURES ARE FORECAST THE NEXT
SEVEN DAYS.
&&
.DISCUSSION...
ONLY STORM ACTIVITY TODAY IN OUR FORECAST AREA WAS IN GILA COUNTY.
THE ONLY STORM ACTIVITY LEFT IN ARIZONA THIS EVENING AS OF THIS
WRITING IS IN FAR SOUTHEAST AND NORTHEAST PORTIONS OF THE STATE.
CONSIDERABLY MORE ACTIVITY IS OVER FAR SOUTHWEST NEW MEXICO
ASSOCIATED WITH AN UPPER LOW. THE 00Z PSR SOUNDING CAME IN WITH A
CAPPING INVERSION NEAR 740 MB BUT THE 03Z SOUNDING SHOWED IT HAD
BEEN DECREASED QUITE A BIT IN ASSOCIATION WITH A LAYER OF
NORTHEASTERLY WINDS AROUND THAT LEVEL. HOWEVER...THERE WAS STILL
SOME CIN TO OVERCOME AND NOT A LOT OF CAPE. THE HRRR MODEL DEPICTS
THE NEW MEXICO ACTIVITY TO ADVECT INTO SOUTHEAST ARIZONA LATER
TONIGHT AND CONTINUE INTO THE MORNING BUT NOT REACH OUR FORECAST
AREA. THUS WILL HOLD ON TO ONLY A SLIVER OF SLIGHT CHANCE POPS OVER
EASTERN GILA COUNTY OVERNIGHT. THE 21Z SREF INDICATES PRECIP
PROBABILITIES FOR WEDNESDAY WILL EXTEND A BIT FURTHER WEST THAN THEY
DID TODAY. THE 00Z GFS AND NAM INDICATE BETTER QPF COVERAGE OVER
SOUTHEAST ARIZONA WEDNESDAY...SPILLING INTO SOUTH-CENTRAL
ARIZONA...AS THE UPPER LOW NEAR THE NEW MEXICO TRIES TO MOVE INTO
ARIZONA. HOWEVER...THEY ALSO SHOW IT NOT GETTING VERY FAR BEING
BLOCKED BY AN UPPER ANTICYCLONE DEVELOPING OVER THE MOHAVE DESERT
REGION. CONSERVATIVE POPS FOR WEDNESDAY STILL LOOK GOOD. NO CHANGES
TO THE FORECAST AT THIS TIME.
&&
.PREVIOUS DISCUSSION ISSUED 245 PM...
THIS EVENING...
REGIONAL WEATHER BALLOON SOUNDINGS SHOWED THE DEEPEST MONSOON
MOISTURE CONTINUED TO RESIDE OVER ALL OF SOUTHERN CA...AND ACROSS
THE SOUTHWEST HALF OF AZ. IT WAS DRIER OVER NORTHEAST AZ AND NW MEW
MEXICO. FOR EXAMPLE...THE 12Z MON SAN DIEGO...YUMA...PHOENIX...LAS
VEGAS...AND TUCSON SOUNDINGS ALL SHOWED BETWEEN 1.50 AND 1.78 INCHES
OF PRECIP WATER...WHILE FLAGSTAFF WAS 0.94 AND ALBUQUERQUE 0.75.
AND...THE LOW LEVEL MONSOON MOISTURE GRADIENT /OR THETA-E GRADIENT/
WAS RATHER TIGHT BETWEEN PHOENIX AND FLAGSTAFF SIGNALING THAT IF
STORMS DEVELOPED OFF THE MOGOLLON RIM...THEY HAVE THE POTENTIAL TO
BACK-BUILD TOWARD THE MOISTURE SOURCE...ON OUTFLOWS...TOWARD THE
CENTRAL DESERTS INCLUDING PHOENIX...WICKENBURG...AND CASA GRANDE
THIS EVENING.
IN THE UPPER LEVELS...THE MEXICAN INVERTED TROF WE HAVE BEEN
TRACKING FROM THE BIG BEND TEXAS AREA SUNDAY AFTERNOON...HAS
WEAKENED CONSIDERABLY AND WAS LOCATED IN SOUTHWEST NEW MEXICO THIS
MORNING. WEAK UPPER LEVEL SOUTHEASTERLY WINDS AROUND THIS SOUTHWEST
NEW MEXICO LOW PRESSURE SYSTEM...AOA 300 MB...CONFLICTING WITH
SOUTHWESTERLY FLOW ALOFT OVER SOUTHWEST AZ...HAS FORMED A
NORTH/SOUTH DEFORMATION ZONE/AXIS OF DILATATION JUST INSIDE THE
EASTERN AZ BORDER. PROGS SHOW THIS DEFORMATION ZONE WILL BECOME
ENHANCED SOMEWHAT IN EASTERN AZ THIS EVENING. STABLE UPPER LEVEL
SOUTHWESTERLY WINDS INCREASE OVER SOUTHERN CA AND SOUTHWEST AZ FOR A
NEAR ZERO CHANCE OF STORMS TONIGHT.
WEDNESDAY...
JUST ABOUT DITTO ON WEDNESDAY AS UPPER LEVEL WINDS AND PLENTY OF
MONSOON MOISTURE FAVOR AFTERNOON/EVENING STORM DEVELOPMENT OVER EAST
CENTRAL AND SOUTHEAST AZ. AGAIN...THE POTENTIAL FOR CONVECTIVE
OUTFLOWS INTO THE CENTRAL DESERTS FROM PHOENIX TO CASA GRANDE WILL
BE THE CATALYST FOR A THREAT OF WEDNESDAY EVENING STORMS. SOUTHEAST
CA AND SOUTHWEST AZ REMAIN DRY.
ON ANOTHER NOTE...THE AIRMASS OVER THE REGION NEVER REALLY DRIES
OUT. MONSOON MOISTURE THINS A BIT WED AND THU...BUT GETS REPLENISHED
FROM THE SOUTHEAST DIRECTION FRIDAY AND SATURDAY.
THURSDAY THROUGH SUNDAY...
CO-LOCATED 300 AND 250 MB HIGH CENTERS GYRATE AROUND SOUTHEAST AZ
THROUGH THIS PERIOD. HARD TO TIME FAVORABLE UPPER LEVEL WINDS TO
SUPPORT TALL CONVECTION WILL DEVELOP OVER SOUTH CENTRAL AND
SOUTHEAST AZ. THEREFORE THE CHANCE OF STORMS INCREASE OVER SOUTH
CENTRAL THIS PERIOD. A SLIGHT CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS MAY DEVELOP IN SOUTHWEST AZ...ESPECIALLY IN YUMA AND
LA PAZ COUNTIES AROUND THE KOFA MOUNTAINS...AND NEAR QUARTZSITE AND
WENDEN.
MONDAY AND TUESDAY...
MONSOON MOISTURE STARTS TO THIN THIS PERIOD...AND A LARGE 300/250 MB
ANTICYCLONE CENTERED IN SOUTHWEST NEW MEXICO WILL HELP TO STABILIZE
MOST OF OUR FORECAST AREA...INCLUDING SOUTHEAST CA...SOUTHWEST
AZ...AND PARTS OF SOUTH CENTRAL AZ. IN OTHERWISE A DRIER AND MORE
STABLE ATMOSPHERE WILL SPREAD INTO THE FORECAST FROM THE WEST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
THUNDERSTORMS OVER GILA AND GRAHAM COUNTIES EAST OF PHOENIX AS OF
00Z WILL STRUGGLE TO SURVIVE OVER THE LOWER ELEVATIONS AND THUS DID
NOT MENTION TSTMS IN THE 00Z TAFS. OUTFLOW DRIVEN WIND SHIFTS FROM
DISTANT STORMS ARE MORE LIKELY BUT CONFIDENCE NOT HIGH ENOUGH TO
DEPICT IN THE TAFS AS OF THIS WRITING. OTHERWISE...EXPECT WESTERLY
SURFACE WINDS THIS EVENING...OCCASIONALLY GUSTING 15-18 KTS...BEFORE
TRANSITIONING TO TYPICAL OVERNIGHT DRAINAGE PATTERNS FAVORING
EASTERLY DIRECTIONS.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
EXPECT FEW TO SCT CU DECREASING DURING THE EVENING...OTHERWISE SKIES
WILL REMAIN MOSTLY CLEAR. WINDS GENERALLY LESS THAN 10KTS FROM THE
SOUTH OVER THE LOWER COLORADO RIVER VALLEY AND WEST OVER THE
IMPERIAL VALLEY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTENING TREND WILL TAKE PLACE FRIDAY AS ANOTHER LOW PRESSURE
SYSTEM MOVES INTO SOUTHERN ARIZONA. SHOWERS AND THUNDERSTORMS WILL
INCREASE IN COVERAGE...PARTICULARLY ACROSS THE EASTERN ARIZONA
HIGHER TERRAIN INCLUDING SOUTHERN GILA COUNTY...BUT ALSO INTO THE
LOWER DESERTS OF SOUTH-CENTRAL ARIZONA. SOUTHWESTERLY FLOW WILL
BRING SOMEWHAT DRIER CONDITIONS TO THE REGION DURING THE LATE
WEEKEND AND INTO NEXT WEEK. A WARMING TREND IS EXPECTED AS
WELL...WITH A RETURN TO NEAR NORMAL TEMPERATURES.
$$
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...VASQUEZ
AVIATION...AJ
FIRE WEATHER...HIRSCH
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
957 PM EDT THU JUL 25 2013
.SYNOPSIS...
A FRONTAL BOUNDARY OFF THE EAST COAST WILL REMAIN NEARLY
STATIONARY THROUGH THE WEEKEND. HIGH PRESSURE ACROSS OUR REGION
WILL MOVE TO THE NORTHEAST BY FRIDAY AS LOW PRESSURE MOVES TOWARD
THE NORTH ALONG THE STALLED BOUNDARY OFFSHORE. ANOTHER COLD FRONT
WILL SLOWLY DROP THROUGH THE AREA SUNDAY NIGHT INTO MONDAY
MORNING. HIGH PRESSURE THEN MOVES BACK IN BEHIND THE COLD FRONT ON
TUESDAY AND WEDNESDAY. ANOTHER COLD FRONT WILL APPROACH THE REGION
ON THURSDAY FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LATEST ESTF UPDATE WE ADDED SOME POPS INTO CENTRAL NJ NEAR THE
WESTERN EDGE OF THE COMMA HEAD. BASED ON RADAR AND HRRR TRENDS,
WE KEPT THE HIEST POPS IN THE NORTHEASTERN PART OF OUR CWA.
OTHERWISE TEMPS AND DEW POINTS REMAIN CLOSE TO EXPECTATIONS.
A STALLED FRONTAL BOUNDARY WILL REMAIN TO OUR EAST AND OFFSHORE
THROUGH TONIGHT, WITH A WAVE OF LOW PRESSURE RIDING NORTHWARD ALONG
THE BOUNDARY. WE HAVE KEPT SLIGHT CHANCE TO LOW CHANCE POPS FOR
SHWRS FOR OUR FAR EASTERN ZONES THROUGH THIS EVENING AND TONIGHT AS
THIS WEAK LOW PRESSURE SLOWLY PASSES BY A FEW HUNDRED MILES OFF THE
COAST. ANY RAINFALL AMOUNT WILL BE LIGHT, AND THUS FAR, ALL OF THE
HEAVIER SHOWER ACTIVITY HAS REMAINED OFFSHORE. AMPLE CLOUD COVER
WILL REMAIN IN PLACE ACROSS THE REGION THROUGH TONIGHT. OVERNIGHT
LOW TEMPERATURES WILL AGAIN BE COMFORTABLE, RANGING FROM THE MID 50S
ACROSS THE SOUTHERN POCONOS AND NORTHWEST NEW JERSEY TO THE MID 60S
ACROSS SOUTHERN NEW JERSEY AND THE DELMARVA. WE USED A BLEND OF MOS
GUIDANCE WITH SOME LOCAL ADJUSTMENTS FOR MINIMUM TEMPERATURES.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
THROUGH THE COURSE OF FRIDAY, WEAK LOW PRESSURE WILL CONTINUE TO
ADVANCE NORTH AND AWAY FROM OUR REGION, WITH THE STALLED FRONTAL
BOUNDARY EDGING FARTHER AWAY FROM THE COAST. OVERALL WITH THE
FEATURES MOVING AWAY, WE EXPECT A PRECIP-FREE DAY FOR THE REGION,
BUT MODEL GUIDANCE INDICATES A FAIR AMOUNT OF CLOUD COVER,
ESPECIALLY THROUGH THE FIRST HALF OF THE DAY. IN ADDITION, A LIGHT
NORTHERLY TO NORTHWESTERLY FLOW WILL CONTINUE OVER THE AREA.
OVERALL, WE AGAIN EXPECT PLEASANT DAYTIME TEMPERATURES AND HUMIDITY,
WITH HIGH TEMPERATURES MAINLY IN THE LOWER 80S. MOS GUIDANCE BLENDED
WITH CONTINUITY WAS UTILIZED FOR MAX TEMPERATURES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
TIME PERIOD BEGINS WITH EAST COAST TROUGHING ALOFT.
ANOTHER PIECE OF ENERGY BEGINS TO DROP INTO THE TROUGH BY
SATURDAY AND FORMS A MID-LEVEL CLOSED LOW ACROSS THE NORTHERN
GREAT LAKES REGION. THIS LOW WILL SLOWLY MOVE TOWARDS THE EAST
THROUGH THE REMAINDER OF THE WEEKEND PUSHING THROUGH ANOTHER COLD
FRONT BY LATE SUNDAY NIGHT.
AFTER A DRY PERIOD FOR FRIDAY NIGHT INTO EARLY SATURDAY, MOISTURE
INCREASES IN THE SOUTHWEST FLOW OUT AHEAD OF THE COLD FRONT AND
PRECIPITATION RETURNS TO THE FORECAST LATE SATURDAY INTO SATURDAY
NIGHT AND SUNDAY. UNUSUALLY STRONG UPPER LEVEL SYSTEM FOR THIS
TIME OF YEAR RESULTS IN UNUSUALLY HIGH POP FORECAST DURING THE
DAY SUNDAY PRIOR TO FRONTAL PASSAGE.
DUE TO THE ALIGNMENT OF THE FRONT AND THE TROUGHING ALOFT, BEING
PARALLEL, THE FRONT WILL STRUGGLE TO PUSH THROUGH, SO WE COULD
HAVE A PROLONGED PERIOD OF SCATTERED SHOWERS AND THUNDERSTORMS
SPILLING INTO MONDAY MORNING. THE UPPER LEVEL COLD POOL ALSO WILL
PASS THROUGH BY MONDAY AFTERNOON SO WE KEPT AT LEAST SLIGHT
CHANCE POPS IN EVERYWHERE THROUGH THE EVENING HOURS.
DRY CONDITIONS RETURN FOR MONDAY NIGHT INTO TUESDAY WITH
PRECIPITATION CHANCES ON THE INCREASE AS WE MOVE INTO WEDNESDAY
AHEAD OF THE NEXT APPROACHING FRONT.
TEMPERATURES THROUGH THIS PERIOD STAY CLOSE TO SEASONAL NORMS...A
CONTINUED MUCH COOLER CHANGE COMPARED TO LAST WEEKS TEMPERATURES.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
WITH THE 00Z TAFS FOR TONIGHT VFR CIGS ARE EXPECTED AT KABE AND
KRDG. THE REST OF THE TERMINALS MVFR CIGS ARE FORECAST TO PREVAIL,
GETTING CLOSE TO IFR LEVELS NEAR THE COAST AND HOVERING CLOSE TO 3K
AT AIRPORTS AND TERMINALS ALONG THE INTERSTATE 95 CORRIDOR. WINDS
WILL BE SLOWLY BACKING TO THE NORTH AND THE DIRECTION IS THE
AVERAGE FOR THE FORECAST PERIOD. SPEEDS SHOULD AVERAGE LESS THAN
10 KTS, ESPECIALLY AT INLAND AIRPORTS. WITH ALL OF THE CLOUDINESS
AND NOT MUCH PRECIPITATION EXPECTED, NO FOG IS FORECAST.
ON FRIDAY MORNING, CIGS SHOULD IMPROVE TO VFR EASTERN TERMINALS
AND NO CIGS ARE FORECAST AT KABE OR KRDG, ALTHOUGH A SCATTERED
CUMULUS DECK SHOULD CONTINUE OR FORM. WINDS WILL CONTINUE TO BACK
TOWARD THE WEST AT SPEEDS LESS THAN 10 KNOTS.
ON FRIDAY AFTERNOON, WE ARE EXPECTING A SCATTERED DECK OF CUMULUS
CLOUDS, EXCEPT FOR KMIV AND KACY WHERE A VFR CIG IS EXPECTED TO
PREVAIL UNTIL A SEA BREEZE FRONT PASSES LATE. WINDS SHOULD SLOWLY
BACK TO THE SOUTHWEST AND CONTINUE TO AVERAGE LESS THAN 10 KNOTS.
A SEA BREEZE FRONT IS FORECAST TO PASS KMIV AND KACY LATE IN THE
DAY AND SHOULD BE IN THE COASTAL DELAWARE AND NEW JERSEY COUNTIES.
OUTLOOK...
FRIDAY NIGHT - SATURDAY...MOSTLY VFR. CONDITIONS COULD BE A LITTLE
WORSE NEAR OUR EASTERN TERMINALS AS A WAVE OF LOW PRESSURE MOVES
BY THE COAST ON FRIDAY AND SATURDAY MORNING.
SUNDAY - MONDAY...MVFR OR LOWER POSSIBLE IN SCATTERED SHOWERS AND
THUNDERSTORMS.
TUESDAY - MOSTLY VFR.
&&
.MARINE...
THE OFFSHORE LOW CONTINUES TO INCREASE SEAS, ESPECIALLY ON OUR
SOUTHERN OCEAN WATERS. GIVEN THIS IS THE GRADIENT`S TIGHTEST PASS,
WE SHOULD BE GETTING CLOSE TO THE HIGHEST SEAS WITH THIS LOW. THE
SMALL CRAFT ADVISORY MAY NEED TO BE EXTENDED BEYOND NOON GIVEN HOW
HIGH THE SEAS HAVE BECOME.
WITH THE CONTINUED NORTHEAST FLOW OVER OUR COASTAL WATERS THROUGH
TONIGHT AND THE FIRST PART OF FRIDAY, SCA CONDITIONS ARE EXPECTED.
SEAS WILL BE IN THE 5 TO 10 FOOT RANGE, WITH WIND GUSTS BETWEEN
20 TO 30 KNOTS. WE HAVE ISSUED A SCA FOR ALL OF OUR COASTAL
WATERS, IN EFFECT THROUGH 16Z FRIDAY. SOME SCATTERED SHOWERS WILL
REMAIN POSSIBLE THROUGH TONIGHT, AS WELL, A WEAK LOW PRESSURE
RIDES NORTHWARD ALONG A STALLED FRONTAL BOUNDARY.
OUTLOOK...
SUB-ADVISORY CONDITIONS EXPECTED ACROSS OUR WATERS. SEAS MAY BE
CLOSE TO FIVE FEET ON SUNDAY IN THE SOUTHWEST FLOW AHEAD OF AN
APPROACHING COLD FRONT. WINDS MAY GUST TO NEAR 20 KNOTS DURING
THAT TIME FRAME. MARINE CONDITIONS WILL IMPROVE ON MONDAY INTO
TUESDAY.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD ADVISORY WILL BE ISSUED FOR THE OVERNIGHT HIGH TIDE
CYCLE ALONG THE OCEAN FRONT, RARITAN BAY AND DELAWARE BAY. THE
COMBINATION OF STILL RELATIVELY HIGH ASTRONOMICAL TIDES
COMING OFF THE FULL MOON AND THE ONSHORE WINDS ASSOCIATED WITH THE
OFFSHORE LOW LASTING INTO THE HIGH TIDE CYCLE SHOULD KEEP TIDAL
DEPARTURES (BASED ON OUR IN HOUSE PROCEDURES AND THE SO FAR MORE
ACCURATE MDL GUIDANCE) AT AROUND ONE FOOT. THIS WOULD GET THE TIDES
INTO MINOR TIDAL FLOODING RANGE AND AROUND OUR THRESHOLD FOR ISSUING
COASTAL FLOOD ADVISORIES. IT DOES NOT LOOK AS THOUGH THE TIDES WILL
REACH LEVELS THAT WOULD REQUIRE COASTAL FLOOD ADVISORIES TO EXTEND
INTO TIDAL SECTIONS OF THE DELAWARE RIVER OR CHESAPEAKE BAY.
&&
.RIP CURRENTS...
WE WILL OUTLOOK A MODERATE RISK FOR RIP CURRENTS FOR TOMORROW GIVEN
HOW SEAS ARE GOING TO BE STARTING RATHER ROBUST.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD ADVISORY UNTIL 2 AM EDT FRIDAY FOR NJZ012>014-
020>027.
DE...COASTAL FLOOD ADVISORY UNTIL 2 AM EDT FRIDAY FOR DEZ002>004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT FRIDAY FOR ANZ450>455.
&&
$$
SYNOPSIS...SZATKOWSKI
NEAR TERM...GIGI/KLINE
SHORT TERM...GIGI/KLINE
LONG TERM...SZATKOWSKI
AVIATION...GIGI/SZATKOWSKI
MARINE...GIGI/SZATKOWSKI/KLINE
TIDES/COASTAL FLOODING...
RIP CURRENTS...
THE AREA FORECAST DISCUSSION ON AN AS NEEDED BASIS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 91 75 89 / 20 50 40 40
FORT LAUDERDALE 78 91 77 90 / 10 40 30 30
MIAMI 78 92 78 90 / 10 20 20 40
NAPLES 79 90 78 90 / 30 20 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
405 AM EDT WED JUL 24 2013
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOW AN UPPER LEVEL PATTERN
ACROSS THE CONUS CONSISTING OF BROAD RIDGING OVER THE INTER-MOUNTAIN
WEST FOLLOWED BY DOWNSTREAM LONGWAVE TROUGHING OVER THE EASTERN HALF
OF THE NATION. OUR FORECAST AREA RESIDES WITHIN A ZONE OF DEEP
LAYER WEST TO NORTHWEST FLOW ON THE SOUTHERN PERIPHERY OF THE
EASTERN CONUS TROUGH. GFS/NAM/ECMWF ALL INITIALIZED A WEAK SHORTWAVE
IMPULSE DROPPING SOUTHEASTWARD INTO THE BASE OF THE TROUGH ACROSS
SOUTHERN AL/GA/NORTH FLORIDA EARLY THIS MORNING. THIS IMPULSE HELPED
FUEL A DECENT BOWING SEGMENT OF CONVECTION TUESDAY EVENING THAT
DROPPED SOUTH THROUGH SOUTHERN AL/FL PANHANDLE. THIS MCS HAS SINCE
DISSIPATED...HOWEVER THE SYNOPTIC SUPPORT FROM THIS FEATURE PASSING
ACROSS THE NORTHEAST GULF/NORTHERN FLORIDA LATER THIS MORNING SHOULD
HELP TO RE-IGNITE AT LEAST A SCATTERING OF SHOWERS/STORMS MOVING
ONSHORE FOR THE NATURE COAST ZONES. MORE ON THIS IN THE SHORT TERM
SECTION BELOW.
AT THE SURFACE...
FORECAST AREA RESIDES WITHIN A ZONE OF LOW LEVEL WESTERLY FLOW
BETWEEN THE SUBTROPICAL RIDGE AXIS OVER FAR SOUTH FLORIDA...AND A
WEAK SURFACE TROUGH EXTENDING FROM THE GA COAST TO THE FL BIG BEND
REGION. REGIONAL RADARS HAVE QUIETED DOWN OVER THE PENINSULA IN THE
PAST SEVERAL HOURS...HOWEVER EVIDENCE OF THE NEXT UPPER LEVEL
IMPULSE MENTIONED ABOVE CAN BE SEEN WITH A SECONDARY CLUSTER OF
CONVECTION DROPPING SOUTH FROM SOUTHERN AL/GA TOWARD THE I-10
CORRIDOR/TALLAHASSEE AREA. THE SUPPORT FOR ADDITIONAL SHOWER/STORM
DEVELOPMENT WILL BE ARRIVING LATER THIS MORNING OVER OUR NORTHERN
ZONES/NE GULF OF MEXICO AND WILL JUST HAVE TO WAIT AND SEE HOW MUCH
RE-DEVELOPMENT WE ACTUALLY GET INTO OUR NATURE COAST ZONES.
&&
.SHORT TERM (TODAY THROUGH FRIDAY)...
TODAY...MAIN PLAYER IN THE FORECAST WILL THE PASSAGE OF A SHORTWAVE
IMPULSE ACROSS THE NORTHERN THIRD OF THE STATE. BASED ON NWP
ENSEMBLE TIMING...WOULD APPEAR THIS IMPULSE WILL HAVE THE MOST
INFLUENCE/SYNOPTIC FORCING OVER OUR NORTHERN ZONES (MAINLY NORTH OF
I-4) AND MAINLY DURING THE MORNING/EARLY AFTERNOON HOURS. LATER IN
THE DAY...LOOKS AS THOSE THE PVA AXIS WILL SHIFT OVER TOWARD THE
EAST COAST OF THE PENINSULA AND EVEN LEAVE PARTS OF THE NATURE COAST
WITHIN A ZONE OF NVA/WEAK SUBSIDENCE BY THE TIME THE EVENING
ARRIVES.
TOUGH CALL ON JUST HOW MUCH CONVECTION THIS IMPULSE WILL RESULT IN
DURING THE NEXT 12 HOURS OR SO FOR OUR AREA. THE BEST RAIN CHANCES
AND POTENTIAL FOR ORGANIZED CONVECTION WILL BE NORTH OF THE I-4
CORRIDOR...HOWEVER ANY CONVECTIVE COLD POOLS PROPAGATING SOUTHWARD
FROM THIS ACTIVITY WOULD BE ENOUGH TO SUPPORT SHOWER/STORMS DOWN
INTO THE TAMPA BAY AREA AS WELL...ESPECIALLY LATE MORNING/EARLY
AFTERNOON. FURTHER SOUTH FROM THE TAMPA BAY AREA...RAIN CHANCES FOR
THE MORNING HOURS/EARLY AFTERNOON WILL DECREASE QUICKLY. SECOND HALF
OF THE AFTERNOON AND INTO THE EVENING HOURS...THE WESTERLY FLOW
SHOULD PUSH ANY FEEBLE SEA-BREEZE WELL INLAND. THIS INLAND
PENETRATION ALONG WITH BETTER SYNOPTIC FORCING TO THE EAST SHOULD
RESULT IN BEST RAIN CHANCES SHIFTING EAST OF THE I-75 CORRIDOR.
AGAIN...THIS IS NOT A VERY DEFINED OR CLIMATOLOGICAL PATTERN FOR
LATE JULY...AND THE RESULTING FORECAST CONFIDENCE IS A BIT LOWER
THAN AVERAGE.
FINALLY...DEVELOPING MODERATE ONSHORE FLOW OVER THE NORTHEAST GULF
OF MEXICO IS EXPECTED TO RESULT IN DEVELOPING CHOPPY AND BREAKING
SURF LATER TONIGHT INTO TONIGHT ALONG THE BEACHES OF PINELLAS...
HILLSBOROUGH...MANATEE...AND SARASOTA COUNTIES. THESE CONDITIONS
WILL RESULT IN AN ELEVATED MODERATE RISK OF RIP CURRENTS ALONG THE
BEACHES OF THESE COUNTIES INTO TONIGHT.
TONIGHT...
LINGERING INLAND SHOWERS AND STORMS WILL FADE BY LATE EVENING WITH
THE LOSS OF DIURNAL HEATING AND THE PASSAGE OF THE SHORTWAVE OFF THE
FLORIDA EAST COAST. ANY BRIEF WEAK NVA/SUBSIDENCE WILL ALSO EXIT BY
THE SECOND HALF OF THE NIGHT LEAVING THE REGION UNDER A BROAD AREA
OF CYCLONIC FLOW AT THE BASE OF THE EASTERN CONUS TROUGH. WESTERLY
LOW LEVEL FLOW IS CLIMATOLOGICALLY FAVORABLE FOR LATE NIGHT
NOCTURNAL SHOWERS DEVELOPING OVER THE NE GULF AND MOVING BACK TOWARD
THE COAST AROUND DAWN. ADD THE CYCLONIC FLOW ALOFT AND IT SEEMS A
GOOD BET THAT THIS SCT ACTIVITY WILL INDEED DEVELOP. WILL BRING
SLIGHT CHANCE 20% POPS BACK TO THE TAMPA BAY COAST AFTER 09Z...AND
CHANCE 30-40% POPS FURTHER NORTH ALONG THE NATURE COAST IN CLOSEST
PROXIMITY TO THE LOW LEVEL FOCUS OF A SURFACE TROUGH AXIS NEAR THE
I-10 CORRIDOR.
THURSDAY/FRIDAY...UPPER TROUGH IS STILL IN PLACE FOR THURSDAY AND
THEN BEGINS TO DE-AMPLIFY ON FRIDAY LEAVING OUR REGION WITHIN A
NEUTRAL UPPER LEVEL PATTERN TO CLOSE OUT THE SHORT-TERM FORECAST
PERIOD. AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS HOLDING IN PLACE
TO OUR SOUTH WILL KEEP A GENERALLY LIGHT WESTERLY FLOW OFF THE
EASTERN GULF OF MEXICO. FORECAST WILL FEATURE A NEAR CLIMO PATTERN
FOR THIS FLOW WITH BEST RAIN CHANCES FOR SCT SHOWERS/STORMS ALONG
THE COAST IN THE MORNING/EARLY AFTERNOON...AND THEN CONVECTION
SHIFTING MAINLY INLAND FROM I-75 AND BECOMING FOR ROBUST FOR THE
LATER PORTION OF THE DAY.
&&
.LONG TERM (SATURDAY THROUGH NEXT TUESDAY)...
THROUGH THE WEEKEND AN UPPER TROUGH DOMINATES THE EASTERN U.S.
WITH A COUPLE OF EMBEDDED SHORT WAVE TROUGHS ROTATING THROUGH
IT...PUSHING A COUPLE OF FRONTAL BOUNDARIES INTO THE SE U.S.
HOWEVER THESE BOUNDARIES ARE EXPECTED TO STALL ALONG THE GA/FL
BORDER AS THE SUBTROPICAL RIDGE AXIS RESIDES OVER OR JUST SOUTH OF
SOUTHERN FL. LIGHT WESTERLY FLOW DOMINATES FOR THE WEEKEND WITH
ISOLATED NOCTURNAL SHOWERS OR STORMS THAT PUSH ONSHORE IN THE
MORNINGS THEN OVER THE INTERIOR IN THE AFTERNOONS AS THEY INCREASE
IN COVERAGE.
FOR MON AND TUE THE UPPER TROUGHINESS BEGINS TO WEAKEN AND LIFT
NORTH AS THE SUBTROPICAL RIDGE BUILDS IN OVER THE GULF AND SHIFTS
NORTHWARD OVER THE STATE. THIS WILL GRADUALLY BACK FLOW TO SOUTHERLY
THEN SOUTHEASTERLY BUT RELAXED ENOUGH TO ALLOW AFTERNOON SEA BREEZES
TO FORM. THIS RESULTS IN A PATTERN OF LATE MORNING TO AFTERNOON
SHOWERS AND STORMS WITH COASTAL LOCATIONS SLIGHTLY FAVORED FOR THE
HIGHEST COVERAGE.
&&
.AVIATION...
MAINLY VFR. THERE IS SOME PATCHY BR BUT THIS IS NOT EXPECTED TO
IMPACT THE TAF TERMINALS. NOCTURNAL GULF SHOWERS MAY REACH
TPA/PIE/SRQ LATER TONIGHT. SCT TSRA NEAR TPA/PIE/LAL/SRQ THROUGH
THE AFTERNOON. LIGHT VARIABLE OR SOUTHWESTERLY WINDS BECOME WESTERLY
AND INCREASE DURING THE DAY...AND WILL BE GUSTY AT TIMES.
&&
.MARINE...
MODERATE WESTERLY FLOW BETWEEN THE SUBTROPICAL RIDGE TO OUR SOUTH
AND A SURFACE TROUGH TO OUR NORTH WILL DEVELOP THIS MORNING AND
LINGER INTO THURSDAY MORNING BEFORE THE GRADIENT BEGINS TO WEAKEN
LATER THURSDAY INTO THE LATER PORTION OF THE WEEK. WINDS MAY AT
TIMES APPROACH CAUTIONARY LEVELS LATER TODAY AND TONIGHT...
ESPECIALLY NORTH OF ENGLEWOOD. THE SUBTROPICAL RIDGE AXIS BUILDS
BACK NORTH ACROSS THE EASTERN GULF OF MEXICO FOR THE UPCOMING
WEEKEND AND EARLY PORTION NEXT WEEK HELPING TO KEEP WINDS AND SEAS
WELL BELOW CAUTIONARY LEVELS.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY VALUES ARE FORECAST TO REMAIN WELL ABOVE CRITICAL
LEVELS THROUGH THE NEXT SEVERAL DAY. HOWEVER...ELEVATED FLOW ALOFT
WILL RESULT IN HIGH DISPERSION INDICES LATER TODAY AND AGAIN ON
THURSDAY
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 78 91 78 / 40 20 30 20
FMY 91 77 90 76 / 20 10 20 20
GIF 91 74 93 74 / 40 20 50 20
SRQ 90 78 90 78 / 30 20 30 30
BKV 91 74 92 72 / 50 30 50 30
SPG 91 80 90 79 / 30 20 30 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK FROM NOON EDT TODAY THROUGH LATE TONIGHT
FOR HILLSBOROUGH-MANATEE-PINELLAS-SARASOTA.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
400 AM EDT WED JUL 24 2013
.DISCUSSION...
...RAIN CHANCES SLIGHTLY ABOVE NORMAL CHANCES THROUGH THIS WEEKEND...
TODAY-TONIGHT...
DEEP LYR TROF OVER THE ERN SEABOARD HAS AMPLIFIED WITH THE H100-H85
AXIS EXTENDING ALMOST TO THE FL BIG BEND. W/SWRLY FLOW ALOFT HAS
INCREASED STEADILY SINCE MIDNIGHT WITH LCL WIND PROFILES SHOWING A
SOLID 15-20KTS THRU 10KFT. LATEST SFC OBS SHOW A 4-5MB SFC PGRAD
BTWN KMFL-KJAX...TIGHT ENOUGH TO SUPPORT SFC WNDS OF THE SAME
MAGNITUDE AFT SUNRISE ACCORDING TO LCL GEOSTROPHIC APPROXIMATION
TABLE.
RUC ANALYSIS: A RESPECTABLE POCKET OF H85-H50 VORTICITY OVER THE
DEEP SOUTH POISED TO ROTATE ACRS THE NORTH AND CENTRAL FL PENINSULA
OVER THE NEXT 24HRS. MID LVL THERMAL PROFILE IS A MIXED BAG WITH
H85-H50 LAPSE RATES BTWN 6.0-6.5C/KM BUT WITH H50 TEMPS BTWN -6C AND
-7C. LITTLE IN THE WAY OF UPR LVL SUPPORT AS THE H30-H20 WIND FIELD
OVER THE ERN GOMEX/W ATLC ARE LARGELY N/NW BLO 20KTS.
EVENING RAOB SOUNDINGS SHOW PLENTIFUL MOISTURE WITH PWAT VALUES BTWN
1.9"-2.0". HOWEVER...THE KTBW SOUNDING SHOWS MUCH OF IT ABV THE H60
LVL WITH DEW POINT DEPRESSIONS THRU THE H90-H60 LYR AOA 5C...
INDICATIVE OF A LACK OF LOW/MID LVL MOISTURE. FURTHERMORE...UPSTREAM
MOISTURE OVER THE GOMEX IS LACKING WITH RUC ANALYSIS SHOWING
H100-H70 MEAN RH VALUES LARGELY AOB 70PCT.
NEITHER THE LACK OF MOISTURE NOR THE TEPID THERMODYNAMIC PROFILE
SUPPORTS HIGH COVERAGE POPS...ESPECIALLY GIVEN THE EAST COAST
SEA BREEZE IS UNLIKELY TO FORM IN SUCH A STRONG WIND FIELD.
HOWEVER...THE VORT MAX OVER THE DEEP SOUTH IS THE WILD CARD AND
SHOULD GENERATE ENOUGH MID LVL SUPPORT TO KICK PRECIP CHANCES TO
50PCT ALONG AND N OF I-4. PRECIP WILL DIMINISH TO 30PCT ARND LAKE
OKEECHOBEE DUE TO LOWER MOISTURE AND WEAKER INFLUENCE WRT THE H50
VORT MAX. LINGERING PRECIP THRU LATE EVNG BUT ENDING BY MIDNIGHT AS
THE VORT MOVES OFFSHORE.
WRLY WINDS AND NO SEABREEZE WILL GENERATE MAX TEMPS IN THE L90S OVER
THE COASTAL COUNTIES...NEAR 90F OVER THE INTERIOR. LIGHT WRLY FLOW
OVERNIGHT WILL PREVENT DECOUPLING...KEEPING MIN TEMPS IN THE M70S.
THU-SAT...LARGER SCALE PATTERN SHOWS THE LARGE/BROAD EASTERN CONUS
SLOWLY FILLING...WITH THE AXIS REDEVELOPING A LITTLE FARTHER WEST BY
THIS WEEKEND. THESE SUBTLE CHANGES ALOFT PORTEND SUBTLE/SLIGHT
CHANGES AT THE SURFACE AS WELL. ON THU...WEAK SURFACE WAVE/LOW NEAR
THE SE ATLC SEABOARD SCOOTS OFF TO THE NE ALONG WITH PARENT SHORT
WAVE TROUGH. FROM LATER FRI ONWARD...SLIGHT BACKING AND WEAKENING OF
THE SURFACE FLOW TAKES PLACE AS THE SURFACE RIDGE ATTEMPTS TO BUILD
WEST TWD FL. MOISTURE REMAINS SUFFICIENTLY DEEP WITH PWATS REMAINING
SLIGHTLY ABOVE NORMAL BY A TENTH OR TWO...AND HENCE POPS WILL DO SO
AS WELL - GENERALLY 40-50 PERCENT). STORM STRENGTH LOOKS PRETTY
TYPICAL...MOSTLY HEAVY RAIN AND LIGHTNING BEING THE MAIN THREATS...
WITH SOME STRONGER (MAINLY SUB-SEVERE) STORMS POSSIBLE. TEMPS LOOK
PRETTY CLOSE TO CLIMO...MAYBE A TAD ABOVE NEAR THE COAST. OVERALL...
SHAVED ABOUT 1-2F FROM MAV MAXES OVER THE INTERIOR.
SUN-WED...DAY 5-8 CONTINUE THE TREND ESTABLISHED IN THE SHORT RANGE.
NAMELY...CONTINUE GRADUALLY FILLING OF THE TROUGH TO THE NORTH WHILST
DEEP LAYER MEAN (DLM) RIDGING CONTINUES TO BUILD WESTWARD FROM THE
ATLANTIC INTO FLORIDA. THIS SHOULD SPELL A SLIGHT DRYING TREND...
WITH CONTINUED BACKING OF SURFACE WINDS MORE TWD THE SE...HENCE LCL
POP DISTRIBUTION WILL FAVOR THE CENTRAL-WESTERN PENINSULA. LOOKING
AT POPS DROPPING BACK MORE TO 30-40 (10 PCT HIGHER OVER THE INTERIOR)
EARLY NEXT WEEK. TEMPS REMAIN FAIRLY CLOSE TO CLIMO.
&&
.AVIATION...THRU 24/14Z...VFR ALL SITES. BTWN 24/14Z-24/16Z...W/SW
SFC WNDS INCRSG TO 12-16KTS WITH G18-24KTS. BTWN 24/16Z-24/24Z...SCT
MVFR SHRAS/IFR TSRAS DVLPG AND MVG E ARND 15KTS...BRIEF LIFR CONDS N
OF KTIX-KISM IN +TSRA BTWN 14/18Z-24/22Z. BTWN 25/00Z-25/03Z...SCT
MVFR SHRAS/ISOLD IFR TSRAS COASTAL SITES N OF KVRB...ISOLD
SHRAS/TSRA INTERIOR AND S OF KVRB. AFT 25/03Z...VFR ALL SITES.
&&
.MARINE...TODAY-TONIGHT...DEEP TROF OVER THE ERN SEABOARD EXTENDING
INTO N FL WILL GENERATE A MODERATE WRLY BREEZE WITH OCNL SFC GUSTS
ABV 20KTS. OFFSHORE WIND COMPONENT WILL GENERATE SHORT PD CHOP
NEARSHORE WITH DOMINANT WAVE PDS EXPECTED TO SHORTEN TO AOB 5 SEC..
.OFFSHORE WAVE PDS 6-8SEC. SCT TSRAS MOVING OFFSHORE THIS AFTN.
THU-SUN...ATLC SURFACE RIDGE WILL REMAIN SOUTH/EAST OF THE CWA
THROUGH EARLY FRI...BEFORE GRADUALLY BUILDING NORTH/WEST TOWARD
THE ECFL MAOR. SEAS WILL BE IN THE 2-3FT RANGE FOR THE MOST PART
...INCREASING SLIGHTLY OFFSHORE BY SUNDAY AS SRLY FLOW FRESHENS
SOME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 90 75 92 75 / 50 30 50 40
MCO 89 75 93 75 / 50 20 50 30
MLB 91 74 91 73 / 40 30 50 40
VRB 91 74 89 73 / 40 20 50 40
LEE 89 75 92 75 / 50 20 50 30
SFB 90 75 94 76 / 50 30 50 30
ORL 89 75 93 76 / 50 20 50 30
FPR 91 74 90 72 / 30 20 50 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX....CRISTALDI
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
137 AM EDT WED JUL 24 2013
.AVIATION...
THE WEATHER SHOULD REMAIN DRY THROUGH THE MORNING HOURS AT ALL OF
THE TAF SITES OF SOUTH FLORIDA. FOR THE AFTERNOON HOURS
TODAY...THERE COULD BE SOME SHOWERS AND EVEN A FEW STORMS OVER THE
EAST COAST METRO AREAS MAINLY BETWEEN 19Z AND 23Z. SO HAVE PUT IN
VCSH FOR THE EAST COAST TAF SITES FROM 17Z UNTIL 03Z...WITH EVEN A
VCTS BETWEEN 20Z AND 01Z. FOR TAPF TAF SITE...THE BEST COVERAGE OF
ANY SHOWERS WILL IN THE AFTERNOON HOURS.
THE CEILING AND VIS WILL ALSO REMAIN IN THE VFR CONDITIONS DUE TO
THE UNKNOWN TIMING OF THE SHOWERS AND THUNDERSTORMS.
THE WINDS WILL REMAIN IN A SOUTHWEST DIRECTION AT 5 KNOTS OR LESS
EARLY THIS MORNING BEFORE INCREASING TO AROUND 10 KNOTS BY THIS
AFTERNOON.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 912 PM EDT TUE JUL 23 2013/
UPDATE...
A FEW SHOWERS/TSTMS ARE LINGERING OVER AND NEAR THE WESTERN
SUBURBS OF SE FLORIDA THIS EVENING AS THE LAST OF TODAY`S
CONVECTION MOVES EAST. EXPECT THIS ACTIVITY TO EITHER DISSIPATE OR
MOVE OFFSHORE BY MIDNIGHT AT THE LATEST, WITH MOSTLY CLEAR AND DRY
CONDITIONS EXPECTED FOR THE OVERNIGHT HOURS. ZONES WILL BE UPDATED
BEFORE 11 PM TO REFLECT THIS, UNLESS SHOWERS/TSTMS LINGER LONGER
THAN EXPECTED.
HYDROLOGY UPDATE...FLOOD WARNING FOR FISHEATING CREEK WILL BE
REEVALUATED WITH NEW RFC GUIDANCE WITHIN THE HOUR TO DETERMINE IF
THE WARNING NEEDS TO BE CONTINUED. CREEK LEVELS HAVE BEEN FALLING
SLIGHTLY SINCE THIS MORNING AND WITH NOT MUCH RAIN IN THE AREA
TODAY, THE CREEK MAY NOT REACH THE FORECAST FLOOD STAGE OF 7 FEET.
&&
MOLLEDA
PREV DISCUSSION... /ISSUED 750 PM EDT TUE JUL 23 2013/
AVIATION...
CONVECTION ACROSS INTERIOR SHOULD CONTINUE TO BE DRIVEN BY
LINGERING OUTFLOW BOUNDARIES ACROSS INTERIOR PALM BEACH...BROWARD
AND MIAMI-DADE COUNTIES FOR THE NEXT FEW HOURS BEFORE DISSIPATING.
OTHERWISE...SOUTHEASTERLY FLOW SHOULD VEER MORE SOUTHWESTERLY
OVERNIGHT AND REMAIN LIGHT. SOUTHWESTERLY FLOW SHOULD PREVAIL
THROUGH THE DAY TOMORROW WHICH SHOULD FOCUS ANY CONVECTIVE
DEVELOPMENT ALONG THE INTERIOR AND EAST COASTAL AREAS.
&&
PREV DISCUSSION... /ISSUED 215 PM EDT TUE JUL 23 2013/
SHORT TERM (TONIGHT-THURSDAY NIGHT)...
A STRONG SUBTROPICAL DEEP LAYER RIDGE CURRENTLY LOCATED ACROSS SOUTH
FLORIDA AND THIS SUPPRESSING THE CONVECTION. THE 12Z MFL SOUNDING
SHOWED THE LOWEST LAYERS OF THE ATMOSPHERE HAD DESTABILIZED
SUBSTANTIALLY FROM 24 HOURS AGO SO CU DEVELOPED EARLIER WHICH HAS
LEAD TO EARLIER SHOWER DEVELOPMENT TOO ALONG WITH A FEW
THUNDERSTORMS. A SEA BREEZE LINE OF CONVECTION DEVELOPED RIGHT ALONG
THE COAST OF SOUTHERN BROWARD AND IT APPEARS THAT SOME ADDITIONAL
CONVERGENCE SET UP OTHER THAN JUST THE SEA BREEZE. LOOKING AT
VISIBLE SATELLITE IMAGES REVEALS A CONVERGENT BOUNDARY ASSOCIATED
WITH AN OUTFLOW/LAND BREEZE OFF THE EAST COAST WITH THIS BAND
EXTENDING WELL OUT INTO THE ATLANTIC. OUTSIDE OF THIS, THERE IS ALSO
A MID LEVEL TROUGH THAT IS DEEPENING OVER THE EASTERN STATES WITH
FORECAST SOUNDINGS INDICATING THE RIDGE WOULD BEGIN TO SHIFT SOUTH
THROUGH THIS AFTERNOON AND THIS APPEARS TO BE OCCURRING WITH LOW
TOPPED CONVECTION ALREADY DRIFTING TO THE EAST. HOWEVER, AS THE
DAY PROGRESSES AND DIURNAL HEATING CAN DESTABILIZE A DEEPER
PORTION OF THE ATMOSPHERE THE STEERING FLOW IS STILL VERY WEAK SO
STORM MOTION IS STILL EXPECTED TO BE SLOW AND POSSIBLY ERRATIC
ALTHOUGH THERE COULD BE A DRIFT TOWARDS THE EAST. SOME OF THE
SHORT RANGE HIGH RESOLUTION MODELS SUCH AS THE HRRR ARE SHOWING
MORE ROBUST CONVECTION FORMING OVER THE INTERIOR AROUND 17-18Z
(ALTHOUGH THIS NOT OCCURRING AS OF 1815Z) AND THEN SLOWLY MOVING
TOWARDS THE EAST BUT THEN AS THE HEATING CYCLE IS CUT OFF WITH A
LOWER SUN ANGLE, THE CONVECTION NEVER MAKES IT QUITE TO THE EAST
COAST AND THIS APPEARS REASONABLE GIVEN THE ABOVE REASONING.
THE RIDGE WILL CONTINUE TO SHIFT SOUTH TONIGHT AND BE OVER THE
FLORIDA STRAITS INCLUDING THE KEYS AS THE TROUGH CONTINUES TO
DEEPEN. THIS WILL ALLOW FOR A DEEP WESTERLY FLOW TO BECOME
ESTABLISHED ON WEDNESDAY AND THURSDAY WITH FORECASTING SOUNDINGS
SHOWING A STORM MOTION OF AROUND 5-7 MPH ON WEDNESDAY AND NEAR 10
MPH ON THURSDAY. NONE OF THE GLOBAL MODELS HOWEVER INDICATE AN
ABUNDANCE OF DEEP LAYER AVAILABLE MOISTURE NOR INSTABILITY SO
WIDESPREAD CONVECTION AT THIS TIME IS NOT EXPECTED. THE NAM, GFS AND
ECMWF ALL SHOW PWAT IN THIS TIME FRAME TO BE 1.5-1.7 INCHES WHICH IS
CLOSE TO OR SLIGHTLY BELOW THE AVERAGE FOR MID TO LATE JULY. BUT THE
SCATTERED STORMS THAT DO DEVELOP IN THIS PATTERN WILL FAVOR THE
INTERIOR AND EAST COAST METRO AREAS.
LONG TERM (FRIDAY-TUESDAY)...
NOT MUCH CHANGE IS FORESEEN LOOKING TOWARDS THE END OF THE WEEK INTO
SATURDAY AS THE MAIN MID LEVEL TROUGH WILL REMAIN IN PLACE ACROSS
THE EASTERN STATES. THIS WILL MAINTAIN THE DEEP WESTERLY FLOW ACROSS
SOUTH FLORIDA WITH A FORECAST PWAT REMAINING NEAR NORMAL VALUES.
NONE OF THE MODELS SHOW ANY KIND OF MOISTURE INFLUX SO AT THIS TIME,
BY LATE IN THE WEEKEND AND INTO EARLY NEXT WEEK SCATTERED
THUNDERSTORMS ARE EXPECTED WITH THE PATTERN AGAIN REVERTING TO
MOSTLY INTERIOR AWAY FROM BOTH COASTS.
MARINE...
LIGHT SOUTH TO SOUTHEAST WIND WILL VEER TO A SOUTH TO SOUTHWEST
DIRECTION ON WEDNESDAY AND CONTINUE THROUGH FRIDAY WITH SEAS LESS
THAN 4 FEET AS THE RIDGE SHIFTS SOUTH OF THE AREA. THE RIDGE WILL
THEN MOVE BACK NORTH OVER THE WEEKEND WITH A RETURN TO A LIGHT
SOUTHEAST WIND.
FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH AMPLE TROPICAL MOISTURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 91 76 90 / 20 40 20 30
FORT LAUDERDALE 77 91 78 89 / 20 30 10 20
MIAMI 76 91 78 90 / 20 30 10 20
NAPLES 74 89 75 87 / 10 20 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...30/KOB
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
157 PM EDT WED JUL 24 2013
.PREV DISCUSSION... /ISSUED 720 AM EDT WED JUL 24 2013/
SHORT TERM /TODAY THROUGH THURSDAY/...
/ISSUED AT 349 AM EDT WED JUL 24 2013/
A VERY ACTIVE WEATHER PATTERN WILL PERSIST TODAY WITH CURRENT
SATELLITE WATER VAPOR IMAGERY SHOWING A SHARP UPPER SHORT WAVE OVER
SE GA AND DEPARTING EASTWARD... AND A SERIES OF MORE SUBTLE
DISTURBANCES EMBEDDED WITHIN THE NW FLOW ALOFT BACK TO THE WEST AND
NW. REGIONAL RADAR SHOWS ISOLATED STORMS ACROSS WESTERN AL... AND
THIS ACTIVITY IS ASSOCIATED WITH A WEAK DISTURBANCE PUSHING ACROSS
WEST TN AND NORTH MS. FURTHER WEST... SATELLITE AND RADAR SHOW A
LARGE CONVECTIVE COMPLEX ACROSS WESTERN OK/AR... AND DROPPING SSE ON
A TRAJECTORY FOR THE SE TX AND LA COASTS. SURFACE ANALYSIS SHOWS A
WEAK FRONTAL BOUNDARY PUSHING INTO NW TN AND EXTENDING NEWD INTO VA.
SHORT RANGE MODELS SHOW THESE SUBTLE DISTURBANCES TO THE WEST
INTERACTING WITH A MOIST /1.8+ PW/ AND MODERATELY UNSTABLE
/2000-2500 CAPE/ AIR MASS OVER GA TO PRODUCE SCATTERED SHOWERS AND
THUNDERSTORMS AGAIN TODAY... MAINLY DURING THE AFTERNOON AND EVENING
HOURS. THE GREATER CHANCES APPEAR TO BE ACROSS NORTH GA AHEAD OF
THIS SAGGING COLD FRONT... AND AGAIN ACROSS THE WESTERN ZONES WHERE
THE LOCAL WRF MODEL SHOWS ANOTHER CONVECTIVE COMPLEX DIVING
SOUTHWARD ACROSS AL AND BRUSHING THE WESTERN COUNTIES DURING THE
AFTERNOON. THE HRRR MODEL SHOWS MORE CONVECTION CONCENTRATED ALONG
AND AHEAD OF THE APPROACHING COLD FRONT THAT PUSHES INTO NORTH GA BY
EARLY-MID AFTERNOON. EXPECT THIS ACTIVITY TO PUSH SOUTH INTO CENTRAL
GA DURING THE LATE AFTERNOON AND EVENING HOURS. THEREFORE... IT
APPEARS STORMS COULD DEVELOP JUST ABOUT ANYWHERE TODAY. THE SLIGHTLY
COOLER AND DRIER AIR ALOFT ASSOCIATED WITH THE NW FLOW CONTINUES TO
SUGGEST A THREAT OF STRONG DOWNBURST WINDS AND LARGE HAIL THIS
AFTERNOON AND EVENING DURING PEAK HEATING. THIS IS ALSO SUPPORTED BY
SPC...WHO HAS BLANKETED A FIVE PERCENT CHANCE OF WIND AND HAIL
THREAT ACROSS THE ENTIRE FORECAST AREA TODAY. ALL WARRANTS MENTION
OF ISOLATED SEVERE STORMS... WITH LOCALLY HEAVY RAIN... DAMAGING
WINDS AND LARGE HAIL IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY.
MODELS SHOW STORM COVERAGE GREATLY DIMINISHING BEFORE MIDNIGHT WITH
LOSS OF DAYTIME HEATING. SHORT RANGE MODELS AGREE ON SAGGING THE
FRONT ACROSS NORTH GA OVERNIGHT WITH SOME DRIER AIR SPREADING DOWN
INTO THE ATLANTA AREA EARLY ON THURSDAY. THIS SHOULD HOLD CONVECTION
DOWN TO ISOLATED OR LESS FOR MUCH OF NORTH GA TO INCLUDE THE ATLANTA
METRO AREA ON THURSDAY. EXPECT MORE SCATTERED CONVECTION ACROSS THE
FAR NE AND CENTRAL ZONES WHERE MODELS SHOW CONVECTION FIRING ALONG
AND OUT AHEAD OF THE NEARLY STATIONARY FRONT. COULD SEE A FEW STRONG
TO SEVERE STORMS ACROSS THE FAR SOUTH AND SE ZONES THURSDAY
AFTERNOON WHERE THE FRONT AND GREATER INSTABILITIES ARE EXPECTED.
AS FOR TEMPS... LEANED TOWARD A BLEND BETWEEN PERSISTENCE AND THE
SLIGHTLY WARMER MAV THROUGH THE SHORT TERM.
39
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
/ISSUED AT 349 AM EDT WED JUL 24 2013/
NO REAL CHANGES TO THE PREVIOUS MODEL TRENDS THROUGH THE EXTENDED
FORECAST PERIOD. FAIRLY GOOD AGREEMENT AMONG THE MEDIUM RANGE MODELS
THROUGH THE WEEKEND AS FAR AS THE LARGER SCALE FEATURES ARE
CONCERNED WITH A PERSISTENT EASTERN U.S. UPPER TROUGH DOMINATING THE
REGIONAL WEATHER. EXTENDED FORECAST PERIOD STARTS OUT IN A BIT OF A
QUIET PERIOD AS THE MAIN UPPER TROUGH AXIS IS EAST OF THE STATE...
WITH SCATTERED...MAINLY DIURNAL...CONVECTION EXPECTED THROUGH
FRIDAY. WEAK NORTHWESTERLY UPPER FLOW WILL KEEP A CHANCE FOR A ROUND
OR TWO OF MORE ORGANIZED CONVECTION ASSOCIATED WITH ANY WEAK RIPPLES
RIDING DOWN THE BACKSIDE OF THE TROUGH...BUT NO DISTINCT SHORT WAVE
IS EVIDENT IN THE MODELS AT THIS TIME. FOR THE WEEKEND...A NEW SHORT
WAVE DIGS INTO THE MID-SOUTH FRIDAY NIGHT AND SWEEPS ACROSS THE
REGION SATURDAY. GFS/ECMWF/CMC/NAM ARE SURPRISINGLY SIMILAR WITH
THIS FEATURE SO I WILL BE BUMPING UP SATURDAY/S POPS INTO THE LIKELY
RANGE. FOR NOW THE MODELS ARE ONLY SHOWING A WEAK SURFACE BOUNDARY
ASSOCIATED WITH THIS FEATURE. ALTHOUGH INSTABILITY IS FORECAST TO
REMAIN MODERATE AT BEST SATURDAY...SOME WEAK SHEAR IS EVIDENT SO
CONVECTION MAY BE A BIT MORE ORGANIZED AND AT LEAST A SMALL INCREASE
IN THE POTENTIAL FOR SEVERE STORMS WILL NEED TO BE WATCHED WITH THIS
SYSTEM. WEAK SURFACE TROUGHING AND WEAK UPPER LEVEL FLOW SETTLE IN
FOR THE REMAINDER OF THE EXTENDED FORECAST PERIOD.
MODELS ARE SHOWING A SIGNIFICANT REDUCTION IN DEEPER LAYER MOISTURE
THURSDAY NIGHT AND FRIDAY...BUT AMPLE LOW-LEVEL MOISTURE REMAINS
AVAILABLE FROM THE MOIST SURFACE CONDITIONS FOR SCATTERED
CONVECTION. BETTER DEEP MOISTURE ACCOMPANIES THE SYSTEM SATURDAY. A
FAIRLY STRONG MOISTURE GRADIENT SETS UP FOR THE BALANCE OF THE
PERIOD INTO THE MIDDLE OF NEXT WEEK WITH RELATIVELY DRY AIR ACROSS
THE NORTH. HOWEVER...IN THE ABSENCE OF A STRONG UPPER RIDGE THERE
SHOULD BE SUFFICIENT MOISTURE AVAILABLE FOR ISOLATED TO
SCATTERED...MAINLY DIURNAL...CONVECTION AREA-WIDE EACH DAY WITH AT
LEAST SLIGHTLY BETTER CHANCES ACROSS CENTRAL GEORGIA.
EXCEPT FOR SATURDAY WITH THE INCREASED CLOUD COVER AND PRECIPITATION
EXPECTED...TEMPERATURES ARE EXPECTED TO REMAIN AROUND SEASONAL
NORMALS THROUGH THE EXTENDED FORECAST PERIOD.
20
.AVIATION...
18Z UPDATE...
INTERMITTENT PERIODS OF MVFR CEILINGS ARE STILL AFFECTING SOME OF
THE METRO TAF SITES. THESE PERIODS APPEAR TO BE SHORT LIVED AND
ARE EXPECTED TO SCATTER OUT THIS AFTERNOON. MAIN CONCERN FOR THE
PERIOD IS CONVECTION. AN AREA OF CONVECTION TO THE WEST WILL
AFFECT CSG SHORTLY. OTHER CONVECTION APPEARS POSSIBLE MOVING FROM NORTH
TO SOUTH TODAY AS A COLD FRONT MOVES INTO THE AREA. STORMS COULD
BE STRONG AND A SEVERE WIND GUST CANNOT BE RULED OUT.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF CONVECTION...HIGH ON ALL OTHER ELEMENTS.
ARG
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 70 89 69 / 40 50 40 20
ATLANTA 87 71 88 71 / 50 50 20 10
BLAIRSVILLE 84 65 81 62 / 50 50 20 20
CARTERSVILLE 87 67 88 66 / 50 50 20 10
COLUMBUS 90 72 92 71 / 50 50 20 10
GAINESVILLE 87 70 87 68 / 50 50 30 20
MACON 90 71 92 71 / 50 50 40 20
ROME 88 68 89 66 / 50 40 20 10
PEACHTREE CITY 88 67 89 67 / 50 50 20 10
VIDALIA 89 73 92 72 / 30 50 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ARG
LONG TERM....20
AVIATION...ARG
AREA FORECAST DISCUSSION...UPDATE
NWS PEACHTREE CITY GA
720 AM EDT WED JUL 24 2013
.SHORT TERM /TODAY THROUGH THURSDAY/...
/ISSUED AT 349 AM EDT WED JUL 24 2013/
A VERY ACTIVE WEATHER PATTERN WILL PERSIST TODAY WITH CURRENT
SATELLITE WATER VAPOR IMAGERY SHOWING A SHARP UPPER SHORT WAVE OVER
SE GA AND DEPARTING EASTWARD... AND A SERIES OF MORE SUBTLE
DISTURBANCES EMBEDDED WITHIN THE NW FLOW ALOFT BACK TO THE WEST AND
NW. REGIONAL RADAR SHOWS ISOLATED STORMS ACROSS WESTERN AL... AND
THIS ACTIVITY IS ASSOCIATED WITH A WEAK DISTURBANCE PUSHING ACROSS
WEST TN AND NORTH MS. FURTHER WEST... SATELLITE AND RADAR SHOW A
LARGE CONVECTIVE COMPLEX ACROSS WESTERN OK/AR... AND DROPPING SSE ON
A TRAJECTORY FOR THE SE TX AND LA COASTS. SURFACE ANALYSIS SHOWS A
WEAK FRONTAL BOUNDARY PUSHING INTO NW TN AND EXTENDING NEWD INTO VA.
SHORT RANGE MODELS SHOW THESE SUBTLE DISTURBANCES TO THE WEST
INTERACTING WITH A MOIST /1.8+ PW/ AND MODERATELY UNSTABLE
/2000-2500 CAPE/ AIR MASS OVER GA TO PRODUCE SCATTERED SHOWERS AND
THUNDERSTORMS AGAIN TODAY... MAINLY DURING THE AFTERNOON AND EVENING
HOURS. THE GREATER CHANCES APPEAR TO BE ACROSS NORTH GA AHEAD OF
THIS SAGGING COLD FRONT... AND AGAIN ACROSS THE WESTERN ZONES WHERE
THE LOCAL WRF MODEL SHOWS ANOTHER CONVECTIVE COMPLEX DIVING
SOUTHWARD ACROSS AL AND BRUSHING THE WESTERN COUNTIES DURING THE
AFTERNOON. THE HRRR MODEL SHOWS MORE CONVECTION CONCENTRATED ALONG
AND AHEAD OF THE APPROACHING COLD FRONT THAT PUSHES INTO NORTH GA BY
EARLY-MID AFTERNOON. EXPECT THIS ACTIVITY TO PUSH SOUTH INTO CENTRAL
GA DURING THE LATE AFTERNOON AND EVENING HOURS. THEREFORE... IT
APPEARS STORMS COULD DEVELOP JUST ABOUT ANYWHERE TODAY. THE SLIGHTLY
COOLER AND DRIER AIR ALOFT ASSOCIATED WITH THE NW FLOW CONTINUES TO
SUGGEST A THREAT OF STRONG DOWNBURST WINDS AND LARGE HAIL THIS
AFTERNOON AND EVENING DURING PEAK HEATING. THIS IS ALSO SUPPORTED BY
SPC...WHO HAS BLANKETED A FIVE PERCENT CHANCE OF WIND AND HAIL
THREAT ACROSS THE ENTIRE FORECAST AREA TODAY. ALL WARRANTS MENTION
OF ISOLATED SEVERE STORMS... WITH LOCALLY HEAVY RAIN... DAMAGING
WINDS AND LARGE HAIL IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY.
MODELS SHOW STORM COVERAGE GREATLY DIMINISHING BEFORE MIDNIGHT WITH
LOSS OF DAYTIME HEATING. SHORT RANGE MODELS AGREE ON SAGGING THE
FRONT ACROSS NORTH GA OVERNIGHT WITH SOME DRIER AIR SPREADING DOWN
INTO THE ATLANTA AREA EARLY ON THURSDAY. THIS SHOULD HOLD CONVECTION
DOWN TO ISOLATED OR LESS FOR MUCH OF NORTH GA TO INCLUDE THE ATLANTA
METRO AREA ON THURSDAY. EXPECT MORE SCATTERED CONVECTION ACROSS THE
FAR NE AND CENTRAL ZONES WHERE MODELS SHOW CONVECTION FIRING ALONG
AND OUT AHEAD OF THE NEARLY STATIONARY FRONT. COULD SEE A FEW STRONG
TO SEVERE STORMS ACROSS THE FAR SOUTH AND SE ZONES THURSDAY
AFTERNOON WHERE THE FRONT AND GREATER INSTABILITIES ARE EXPECTED.
AS FOR TEMPS... LEANED TOWARD A BLEND BETWEEN PERSISTENCE AND THE
SLIGHTLY WARMER MAV THROUGH THE SHORT TERM.
39
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
/ISSUED AT 349 AM EDT WED JUL 24 2013/
NO REAL CHANGES TO THE PREVIOUS MODEL TRENDS THROUGH THE EXTENDED
FORECAST PERIOD. FAIRLY GOOD AGREEMENT AMONG THE MEDIUM RANGE MODELS
THROUGH THE WEEKEND AS FAR AS THE LARGER SCALE FEATURES ARE
CONCERNED WITH A PERSISTENT EASTERN U.S. UPPER TROUGH DOMINATING THE
REGIONAL WEATHER. EXTENDED FORECAST PERIOD STARTS OUT IN A BIT OF A
QUIET PERIOD AS THE MAIN UPPER TROUGH AXIS IS EAST OF THE STATE...
WITH SCATTERED...MAINLY DIURNAL...CONVECTION EXPECTED THROUGH
FRIDAY. WEAK NORTHWESTERLY UPPER FLOW WILL KEEP A CHANCE FOR A ROUND
OR TWO OF MORE ORGANIZED CONVECTION ASSOCIATED WITH ANY WEAK RIPPLES
RIDING DOWN THE BACKSIDE OF THE TROUGH...BUT NO DISTINCT SHORT WAVE
IS EVIDENT IN THE MODELS AT THIS TIME. FOR THE WEEKEND...A NEW SHORT
WAVE DIGS INTO THE MID-SOUTH FRIDAY NIGHT AND SWEEPS ACROSS THE
REGION SATURDAY. GFS/ECMWF/CMC/NAM ARE SURPRISINGLY SIMILAR WITH
THIS FEATURE SO I WILL BE BUMPING UP SATURDAY/S POPS INTO THE LIKELY
RANGE. FOR NOW THE MODELS ARE ONLY SHOWING A WEAK SURFACE BOUNDARY
ASSOCIATED WITH THIS FEATURE. ALTHOUGH INSTABILITY IS FORECAST TO
REMAIN MODERATE AT BEST SATURDAY...SOME WEAK SHEAR IS EVIDENT SO
CONVECTION MAY BE A BIT MORE ORGANIZED AND AT LEAST A SMALL INCREASE
IN THE POTENTIAL FOR SEVERE STORMS WILL NEED TO BE WATCHED WITH THIS
SYSTEM. WEAK SURFACE TROUGHING AND WEAK UPPER LEVEL FLOW SETTLE IN
FOR THE REMAINDER OF THE EXTENDED FORECAST PERIOD.
MODELS ARE SHOWING A SIGNIFICANT REDUCTION IN DEEPER LAYER MOISTURE
THURSDAY NIGHT AND FRIDAY...BUT AMPLE LOW-LEVEL MOISTURE REMAINS
AVAILABLE FROM THE MOIST SURFACE CONDITIONS FOR SCATTERED
CONVECTION. BETTER DEEP MOISTURE ACCOMPANIES THE SYSTEM SATURDAY. A
FAIRLY STRONG MOISTURE GRADIENT SETS UP FOR THE BALANCE OF THE
PERIOD INTO THE MIDDLE OF NEXT WEEK WITH RELATIVELY DRY AIR ACROSS
THE NORTH. HOWEVER...IN THE ABSENCE OF A STRONG UPPER RIDGE THERE
SHOULD BE SUFFICIENT MOISTURE AVAILABLE FOR ISOLATED TO
SCATTERED...MAINLY DIURNAL...CONVECTION AREA-WIDE EACH DAY WITH AT
LEAST SLIGHTLY BETTER CHANCES ACROSS CENTRAL GEORGIA.
EXCEPT FOR SATURDAY WITH THE INCREASED CLOUD COVER AND PRECIPITATION
EXPECTED...TEMPERATURES ARE EXPECTED TO REMAIN AROUND SEASONAL
NORMALS THROUGH THE EXTENDED FORECAST PERIOD.
20
&&
.AVIATION...
12Z UPDATE...
WIDESPREAD IFR AND MVFR CIGS THIS MORNING WILL GRADUALLY IMPROVE TO
VFR LEVELS BY 15-16Z THIS MORNING. AN ACTIVE NW FLOW ALOFT WILL
RESULT IN ANOTHER ROUND OF SCATTERED CONVECTION THIS AFTERNOON AND
EVENING...MAINLY BETWEEN 18-24Z. WILL SHOW TEMPO TSRA 20-24Z AT ALL
AIRPORTS TODAY. EXPECT WNW WINDS AROUND 10-12KTS WITH OCCASIONAL
HIGHER GUSTS TODAY. MODELS SHOW A COLD FRONT SAGGING SOUTH OF ATL BY
09Z THU... SO EXPECT VFR CONDITIONS OVERNIGHT. THE DRIER AIRMASS
BEHIND THE FRONT WILL KEEP ANY CONVECTION AROUND ATL ISOLATED AT
BEST ON THU.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM ON AFTERNOON CONVECTION AROUND AIRPORTS. HIGH ON ALL
ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 89 70 89 69 / 30 30 40 20
ATLANTA 87 71 88 71 / 40 30 20 10
BLAIRSVILLE 84 65 81 62 / 40 30 30 20
CARTERSVILLE 88 67 88 66 / 50 30 20 10
COLUMBUS 90 72 92 71 / 40 30 40 10
GAINESVILLE 87 70 87 68 / 40 30 30 20
MACON 91 71 92 71 / 40 30 40 20
ROME 88 68 89 66 / 50 30 20 10
PEACHTREE CITY 87 67 89 67 / 40 30 20 10
VIDALIA 91 73 92 72 / 30 30 50 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...39
LONG TERM....20
AVIATION...39
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
349 AM EDT WED JUL 24 2013
.SHORT TERM /TODAY THROUGH THURSDAY/...
A VERY ACTIVE WEATHER PATTERN WILL PERSIST TODAY WITH CURRENT
SATELLITE WATER VAPOR IMAGERY SHOWING A SHARP UPPER SHORT WAVE OVER
SE GA AND DEPARTING EASTWARD... AND A SERIES OF MORE SUBTLE
DISTURBANCES EMBEDDED WITHIN THE NW FLOW ALOFT BACK TO THE WEST AND
NW. REGIONAL RADAR SHOWS ISOLATED STORMS ACROSS WESTERN AL... AND
THIS ACTIVITY IS ASSOCIATED WITH A WEAK DISTURBANCE PUSHING ACROSS
WEST TN AND NORTH MS. FURTHER WEST... SATELLITE AND RADAR SHOW A
LARGE CONVECTIVE COMPLEX ACROSS WESTERN OK/AR... AND DROPPING SSE ON
A TRAJECTORY FOR THE SE TX AND LA COASTS. SURFACE ANALYSIS SHOWS A
WEAK FRONTAL BOUNDARY PUSHING INTO NW TN AND EXTENDING EWD INTO VA.
SHORT RANGE MODELS SHOW THESE SUBTLE DISTURBANCES TO THE WEST
INTERACTING WITH A MOIST /1.8+ PW/ AND MODERATELY UNSTABLE
/2000-2500 CAPE/ AIR MASS OVER GA TO PRODUCE SCATTERED SHOWERS AND
THUNDERSTORMS AGAIN TODAY... MAINLY DURING THE AFTERNOON AND EVENING
HOURS. THE GREATER CHANCES APPEAR TO BE ACROSS NORTH GA AHEAD OF
THIS SAGGING COLD FRONT... AND AGAIN ACROSS THE WESTERN ZONES WHERE
THE LOCAL WRF MODEL SHOWS ANOTHER CONVECTIVE COMPLEX DIVING
SOUTHWARD ACROSS AL AND BRUSHING THE WESTERN COUNTIES DURING THE
AFTERNOON. THE HRRR MODEL SHOWS MORE CONVECTION CONCENTRATED ALONG
AND AHEAD OF THE APPROACHING COLD FRONT THAT PUSHES INTO NORTH GA BY
EARLY-MID AFTERNOON. EXPECT THIS ACTIVITY TO PUSH SOUTH INTO CENTRAL
GA DURING THE LATE AFTERNOON AND EVENING HOURS. THEREFORE... IT
APPEARS STORMS COULD DEVELOP JUST ABOUT ANYWHERE TODAY. THE SLIGHTLY
COOLER AND DRIER AIR ALOFT ASSOCIATED WITH THE NW FLOW CONTINUES TO
SUGGEST A THREAT OF STRONG DOWNBURST WINDS AND LARGE HAIL THIS
AFTERNOON AND EVENING DURING PEAK HEATING. THIS IS ALSO SUPPORTED BY
SPC...WHO HAS BLANKETED A FIVE PERCENT CHANCE OF WIND AND HAIL
THREAT ACROSS THE ENTIRE FORECAST AREA TODAY. ALL WARRANTS MENTION OF
ISOLATED SEVERE STORMS... WITH LOCALLY HEAVY RAIN... DAMAGING WINDS
AND LARGE HAIL IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY. MODELS
SHOW STORM COVERAGE GREATLY DIMINISHING BEFORE MIDNIGHT WITH LOSS OF
DAYTIME HEATING. SHORT RANGE MODELS AGREE ON SAGGING THE FRONT
ACROSS NORTH GA OVERNIGHT WITH SOME DRIER AIR SPREADING DOWN INTO
THE ATLANTA AREA EARLY ON THURSDAY. THIS SHOULD HOLD CONVECTION DOWN
TO ISOLATED OR LESS FOR MUCH OF NORTH GA TO INCLUDE THE ATLANTA
METRO AREA ON THURSDAY. EXPECT MORE SCATTERED CONVECTION ACROSS THE
FAR NE AND CENTRAL ZONES WHERE MODELS SHOW CONVECTION FIRING ALONG
AND OUT AHEAD OF THE NEARLY STATIONARY FRONT. COULD SEE A FEW STRONG
TO SEVERE STORMS ACROSS THE FAR SOUTH AND SE ZONES THURSDAY
AFTERNOON WHERE THE FRONT AND GREATER INSTABILITIES ARE EXPECTED.
AS FOR TEMPS... LEANED TOWARD A BLEND BETWEEN PERSISTENCE AND THE
SLIGHTLY WARMER MAV THROUGH THE SHORT TERM.
39
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
NO REAL CHANGES TO THE PREVIOUS MODEL TRENDS THROUGH THE EXTENDED
FORECAST PERIOD. FAIRLY GOOD AGREEMENT AMONG THE MEDIUM RANGE MODELS
THROUGH THE WEEKEND AS FAR AS THE LARGER SCALE FEATURES ARE
CONCERNED WITH A PERSISTENT EASTERN U.S. UPPER TROUGH DOMINATING THE
REGIONAL WEATHER. EXTENDED FORECAST PERIOD STARTS OUT IN A BIT OF A
QUIET PERIOD AS THE MAIN UPPER TROUGH AXIS IS EAST OF THE STATE...
WITH SCATTERED...MAINLY DIURNAL...CONVECTION EXPECTED THROUGH
FRIDAY. WEAK NORTHWESTERLY UPPER FLOW WILL KEEP A CHANCE FOR A ROUND
OR TWO OF MORE ORGANIZED CONVECTION ASSOCIATED WITH ANY WEAK RIPPLES
RIDING DOWN THE BACKSIDE OF THE TROUGH...BUT NO DISTINCT SHORT WAVE
IS EVIDENT IN THE MODELS AT THIS TIME. FOR THE WEEKEND...A NEW SHORT
WAVE DIGS INTO THE MID-SOUTH FRIDAY NIGHT AND SWEEPS ACROSS THE
REGION SATURDAY. GFS/ECMWF/CMC/NAM ARE SURPRISINGLY SIMILAR WITH
THIS FEATURE SO I WILL BE BUMPING UP SATURDAY/S POPS INTO THE LIKELY
RANGE. FOR NOW THE MODELS ARE ONLY SHOWING A WEAK SURFACE BOUNDARY
ASSOCIATED WITH THIS FEATURE. ALTHOUGH INSTABILITY IS FORECAST TO
REMAIN MODERATE AT BEST SATURDAY...SOME WEAK SHEAR IS EVIDENT SO
CONVECTION MAY BE A BIT MORE ORGANIZED AND AT LEAST A SMALL INCREASE
IN THE POTENTIAL FOR SEVERE STORMS WILL NEED TO BE WATCHED WITH THIS
SYSTEM. WEAK SURFACE TROUGHING AND WEAK UPPER LEVEL FLOW SETTLE IN
FOR THE REMAINDER OF THE EXTENDED FORECAST PERIOD.
MODELS ARE SHOWING A SIGNIFICANT REDUCTION IN DEEPER LAYER MOISTURE
THURSDAY NIGHT AND FRIDAY...BUT AMPLE LOW-LEVEL MOISTURE REMAINS
AVAILABLE FROM THE MOIST SURFACE CONDITIONS FOR SCATTERED
CONVECTION. BETTER DEEP MOISTURE ACCOMPANIES THE SYSTEM SATURDAY. A
FAIRLY STRONG MOISTURE GRADIENT SETS UP FOR THE BALANCE OF THE
PERIOD INTO THE MIDDLE OF NEXT WEEK WITH RELATIVELY DRY AIR ACROSS
THE NORTH. HOWEVER...IN THE ABSENCE OF A STRONG UPPER RIDGE THERE
SHOULD BE SUFFICIENT MOISTURE AVAILABLE FOR ISOLATED TO
SCATTERED...MAINLY DIURNAL...CONVECTION AREA-WIDE EACH DAY WITH AT
LEAST SLIGHTLY BETTER CHANCES ACROSS CENTRAL GEORGIA.
EXCEPT FOR SATURDAY WITH THE INCREASED CLOUD COVER AND PRECIPITATION
EXPECTED...TEMPERATURES ARE EXPECTED TO REMAIN AROUND SEASONAL
NORMALS THROUGH THE EXTENDED FORECAST PERIOD.
20
&&
AVIATION...
06Z UPDATE...
AREAS OF -RA HAVE DISSIPATED... BUT GROUNDS ARE WET AROUND THE
AIRPORTS. AS A RESULT... LOW STRATUS AND PATCHY FOG HAS ALREADY
BEGAN TO DEVELOP...WITH IFR CIGS EXPECTED TO PREVAIL AT ALL AIRPORTS
EARLY THIS MORNING...AND LINGERING THROUGH AROUND 14Z. THEN VFR CIGS
PREVAIL TODAY OUTSIDE OF CONVECTION. ANOTHER ROUND OF CONVECTION IS
EXPECTED THIS AFTERNOON...MAINLY BETWEEN 18-24Z. LIGHT WNW WINDS
THIS MORNING WILL INCREASE TO AROUND 10-12KTS BY LATE MORNING WITH
OCCASIONAL HIGHER GUSTS. MODELS SHOW VFR CIGS OVERNIGHT...BUT WOULD
EXPECT AT LEAST SCT010 BY 09Z THU AT MOST SITES.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON AFTERNOON CONVECTION HITTING THE AIRPORTS. HIGH ON ALL
ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 89 70 89 69 / 30 30 40 20
ATLANTA 87 71 88 71 / 40 30 20 10
BLAIRSVILLE 84 65 81 62 / 40 30 30 20
CARTERSVILLE 88 67 88 66 / 50 30 20 10
COLUMBUS 90 72 92 71 / 40 30 40 10
GAINESVILLE 87 70 87 68 / 40 30 30 20
MACON 91 71 92 71 / 40 30 40 20
ROME 88 68 89 66 / 50 30 20 10
PEACHTREE CITY 87 67 89 67 / 40 30 20 10
VIDALIA 91 73 92 72 / 30 30 50 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...39
LONG TERM....20
AVIATION...39
AREA FORECAST DISCUSSION
NWS LINCOLN IL
900 PM CDT THU JUL 25 2013
.DISCUSSION...
ISSUED 900 PM CDT THU JUL 25 2013
EAST-WEST AREA OF SHOWERS/STORMS IS DROPPING SOUTHWARD ACROSS IOWA
AND SOUTHWEST WISCONSIN...WITH A WING OF SCATTERED STORMS
INCREASING OVER SOUTHEAST IOWA DURING THE LAST HOUR OR SO.
QUESTION REMAINS AS TO HOW FAR SOUTHEAST THIS WILL PENETRATE THE
CWA OVERNIGHT. EVENING SOUNDINGS FROM LINCOLN AND DAVENPORT SHOW A
FAIR AMOUNT OF DRY AIR THAT NEEDS TO BE SATURATED FIRST...WITH
SOME MOISTURE ADVECTION ALREADY ONGOING WITH DEW POINTS INTO THE
60-65 RANGE OVER A GOOD PORTION OF THE FORECAST AREA. NEWLY-
ARRIVED EVENING NAM MODEL KEEPS THE RAIN OUT OF THE CWA THROUGH
SUNRISE...WHILE THE RAP AND HRRR SHOW SOME POST-MIDNIGHT ACTIVITY
ALBEIT ON THE DECREASE. THINK THE PROXIMITY OF THE STORMS IN
SOUTHEAST IOWA WARRANTS A MINOR BUMP IN RAIN CHANCES ACROSS THE
FAR NORTHWEST CWA...BUT HAVE KEPT THE CWA DRY EAST OF THE ILLINOIS
RIVER OVERNIGHT. HAVE ALSO INCREASED THE SKY COVER AS THE CIRRUS
THICKENS QUICKLY...ALTHOUGH THE SOUTHEAST CWA IS STILL EXPECTED TO
LARGELY BE PARTLY CLOUDY. TEMPERATURES ONLY REQUIRED SOME MINOR
ADJUSTMENTS...MAINLY TO THE HOURLY TRENDS.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 622 PM CDT THU JUL 25 2013
LINE OF THUNDERSTORMS FROM CENTRAL WISCONSIN TO NORTHEAST IOWA AT
23Z WILL CONTINUE TO PUSH EAST-SOUTHEAST. A FAIR AMOUNT OF DRY AIR
IS STILL PROGGED TO BE PRESENT OVER MUCH OF CENTRAL ILLINOIS WELL
INTO THE NIGHT...SO THERE IS SOME QUESTION AS TO HOW FAR IT WILL
MAKE IT. HRRR IS MOST AGGRESSIVE BY BRINGING IT TO KPIA BY 08Z...
BUT MOST OF THE OTHER MODELS HOLD OFF THERE UNTIL AFTER 12Z. FOR
NOW WILL KEEP THE PRECIP OUT OF THE TAFS THROUGH 12Z AND CONTINUE
TO EVALUATE THE LINE OVER THE NEXT FEW HOURS. MAIN PERIOD OF
CONVECTION MOST LIKELY IN ABOUT THE 14-20Z TIME FRAME. THE FRONT
ITSELF SHOULD BEGIN MOVING INTO CENTRAL ILLINOIS TOWARD THE END OF
THE FORECAST PERIOD.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT THU JUL 25 2013
THE INITIAL CONCERNS WILL FOCUS ON THE COLD FRONT DROPPING
SOUTHEAST FROM SOUTH DAKOTA AND S MINNESOTA. THEN THE FOCUS WILL
BE THE ABNORMALLY COOL AIR MASS, WITH NEAR RECORD LOWS SUNDAY
MORNING AFTER UNSEASONABLY COOL HIGH TEMPS SATURDAY. A MORE POTENT
LOW IS FORECAST FOR NEXT MONDAY NIGHT THROUGH TUESDAY
NIGHT...WITH STORMS AHEAD OF THAT PROGRESSIVE WAVE.
SHORT TERM...TONIGHT THROUGH SUNDAY.
00Z/25 MODELS SHIFTED TO A FASTER MOVEMENT OF THE NEXT COLD
FRONT...THEN THEY SLOWED IT DOWN AGAIN WITH THIS MORNINGS 12Z/25
RUNS. BEST BET ON PRECIP WITH THIS FRONT WILL BE TO HOLD IT OFF
UNTIL CLOSER TO THE FRONT...MAINLY BECAUSE IT IS HEADING INTO THE
ANTECEDENT DRY AIR MASS AFTER A DRIER SPELL. THE MODELS ARE
KICKING OFF PRECIP WELL AHEAD OF THE FRONT BY FRIDAY MORNING...BUT
MOST INDICATIONS ARE THAT THE FRONT WILL NOT ARRIVE UNTIL LATER
FRIDAY AFTERNOON...REACHING PIA AROUND 00Z/7 PM FRIDAY. ANOTHER
FLY IN THE OINTMENT IS THAT THE LAST 2 RUNS OF THE 4KM NCEP MODEL
HAS SHOWN SHOWERS REACHING TO PIA AND ALMOST BMI BY 12Z TOMORROW
MORNING. THE VERY DRY AIR MASS MAY HAMPER THAT PROGRESS SOME...SO
WE ARE NOT HITTING POPS VERY HARD IN THE MORNING ON FRIDAY. WE DID
KEEP CHANCE POPS ACROSS THE N-NW...BUT HELD OFF ON HIGHER CHANCE
UNTIL LATER AFTERNOON AND EVENING. THE GFS IS TRENDING TOWARD A
DRIER SOLUTION FOR THE ENTIRE FRONTAL PACKAGE...WHICH MAKES MORE
SENSE WITH THE CURRENT AIR MASS AND DRY TRENDS. THE NAM/ECMWF/GEM
ARE ALL WETTER AND MORE ACTIVE ALONG THE FRONT.
SATURDAY MORNING WILL SEE THE FRONT DEPARTING INTO INDIANA...WITH
SOME FRONTAL SHOWERS STILL LINGERING EAST OF I-57. SATURDAY
AFTERNOON WILL BE PLAGUED BY STEEP LAPSE RATES IN A VERY CHILLY
AIR MASS FOR THIS TIME OF YEAR. LOW LEVEL UPDRAFTS MAY BECOME
STRONG ENOUGH TO GENERATE INSTABILITY SHOWERS...ESPECIALLY ACROSS
NORTHERN ILLINOIS. WE ADDED A SLIGHT CHANCE ACROSS THE NORTH FOR
SAT AFTERNOON...BUT I CAN SEE THAT NEEDING TO BE EXPANDED BASED ON
THE AMOUNT OF BULK SHEAR AND INSTABILITY. A 500MB SHORTWAVE WILL
BE ENHANCING UPDRAFTS AS WELL.
VERY COOL HIGHS MAY BE IN STORE ON SATURDAY. SPRINGFIELD`S COLDEST
HIGH WAS 67 BACK IN 1891 AND PEORIA`S WAS 71 IN 1980. WE ARE
FORECASTING 74 FOR SPRINGFIELD AND 72 FOR PEORIA...BUT IF CLOUD
COVER GETS THICK ENOUGH SAT AFTERNOON...WE COULD SEE SOME RECORD
COLD HIGHS SAT AFTERNOON. DEPENDING ON HOW QUICKLY WE CLEAR OUT
SAT NIGHT...WE COULD SEE A FEW RECORD LOWS REACHED SUNDAY MORNING.
THE RECORD LOW FOR PIA AND SPI IS 53 AND WE ARE FORECASTING 53/PIA
AND 54/SPI. REGARDLESS IF WE HIT RECORDS OR NOT...IT WILL BE A BIG
CHANGE FROM THE HEAT AND HUMIDITY OF JULY 15-19.
SUNDAY MAY SEE A FEW INSTABILITY SHOWERS AS WELL...DUE TO THE
UPPER TROUGH AND COLD POOL LINGERING OVER THE WESTERN GREAT LAKES.
HIGHS SHOULD BE WARMER...BUT STILL IN THE 70S.
LONG TERM...MONDAY THROUGH THURSDAY.
THE EXTENDED MODELS ARE IN DECENT AGREEMENT ON A MORE POTENT LOW
PRESSURE SYSTEM EJECTING FROM THE PLAINS ON MONDAY. IT IS EXPECTED
TO TRIGGER STORMS ON MONDAY NIGHT IN OUR WEST...AND PROGRESS THEM
ACROSS CENTRAL ILLINOIS TUESDAY. SOME STORMS MAY LINGER TUESDAY
EVENING...DEPENDING ON THE ADVANCEMENT OF THE TRAILING COLD FRONT.
THE FRONT MAY END UP BECOMING PARALLEL WITH THE UPPER FLOW BEHIND
THE LOW AND LINGER LONGER THAN THE CANADIAN GEM IS SHOWING. GFS
STALLS OUT A BOUNDARY IN THE AREA INTO WEDNESDAY AS A SECONDARY
SHORTWAVE MOVES EAST FROM KANSAS ACROSS SOUTHERN IL.
THE END RESULT WAS FOR POPS TO GET BUMPED TO LIKELY WEST OF PIA TO
SPI ON MONDAY NIGHT...WITH HIGH CHANCE POPS EAST OF THERE THROUGH
TUESDAY. LOW CHANCE POPS IN THE EAST FOR TUESDAY NIGHT AND IN THE
FAR SOUTHEAST FOR WED WERE MORE TENUOUS. THE SYSTEM HAS
PROGRESSIVE FEATURES WITH THE FASTER UPPER FLOW...SO CONFIDENCE IS
LOW ON POPS AFTER TUESDAY. THURSDAY MAY SEE A FEW SHOWERS AND
STORMS DEVELOP AS THE ZONAL FLOW SENDS VARIOUS SHORTWAVES FROM THE
PLAINS INTO ILLINOIS. WARMER TEMPS WILL DEVELOP NEXT WEEK AS
WELL...ONCE THE CANADIAN AIR MASS SHIFTS TO THE EAST BEGINNING ON
MONDAY.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
622 PM CDT THU JUL 25 2013
.DISCUSSION...
ISSUED 300 PM CDT THU JUL 25 2013
THE INITIAL CONCERNS WILL FOCUS ON THE COLD FRONT DROPPING
SOUTHEAST FROM SOUTH DAKOTA AND S MINNESOTA. THEN THE FOCUS WILL
BE THE ABNORMALLY COOL AIRMASS, WITH NEAR RECORD LOWS SUNDAY
MORNING AFTER UNSEASONABLY COOL HIGH TEMPS SATURDAY. A MORE POTENT
LOW IS FORECAST FOR NEXT MONDAY NIGHT THROUGH TUESDAY
NIGHT...WITH STORMS AHEAD OF THAT PROGRESSIVE WAVE.
SHORT TERM...TONIGHT THROUGH SUNDAY.
00Z/25 MODELS SHIFTED TO A FASTER MOVEMENT OF THE NEXT COLD
FRONT...THEN THEY SLOWED IT DOWN AGAIN WITH THIS MORNINGS 12Z/25
RUNS. BEST BET ON PRECIP WITH THIS FRONT WILL BE TO HOLD IT OFF
UNTIL CLOSER TO THE FRONT...MAINLY BECAUSE IT IS HEADING INTO THE
ANTECEDENT DRY AIRMASS AFTER A DRIER SPELL. THE MODELS ARE
KICKING OFF PRECIP WELL AHEAD OF THE FRONT BY FRIDAY MORNING...BUT
MOST INDICATIONS ARE THAT THE FRONT WILL NOT ARRIVE UNTIL LATER
FRIDAY AFTERNOON...REACHING PIA AROUND 00Z/7 PM FRIDAY. ANOTHER
FLY IN THE OINTMENT IS THAT THE LAST 2 RUNS OF THE 4KM NCEP MODEL
HAS SHOWN SHOWERS REACHING TO PIA AND ALMOST BMI BY 12Z TOMORROW
MORNING. THE VERY DRY AIRMASS MAY HAMPER THAT PROGRESS SOME...SO
WE ARE NOT HITTING POPS VERY HARD IN THE MORNING ON FRIDAY. WE DID
KEEP CHANCE POPS ACROSS THE N-NW...BUT HELD OFF ON HIGHER CHANCE
UNTIL LATER AFTERNOON AND EVENING. THE GFS IS TRENDING TOWARD A
DRIER SOLUTION FOR THE ENTIRE FRONTAL PACKAGE...WHICH MAKES MORE
SENSE WITH THE CURRENT AIRMASS AND DRY TRENDS. THE NAM/ECMWF/GEM
ARE ALL WETTER AND MORE ACTIVE ALONG THE FRONT.
SATURDAY MORNING WILL SEE THE FRONT DEPARTING INTO INDIANA...WITH
SOME FRONTAL SHOWERS STILL LINGERING EAST OF I-57. SATURDAY
AFTERNOON WILL BE PLAGUED BY STEEP LAPSE RATES IN A VERY CHILLY
AIRMASS FOR THIS TIME OF YEAR. LOW LEVEL UPDRAFTS MAY BECOME
STRONG ENOUGH TO GENERATE INSTABILITY SHOWERS...ESPECIALLY ACROSS
NORTHERN ILLINOIS. WE ADDED A SLIGHT CHANCE ACROSS THE NORTH FOR
SAT AFTERNOON...BUT I CAN SEE THAT NEEDING TO BE EXPANDED BASED ON
THE AMOUNT OF BULK SHEAR AND INSTABILITY. A 500MB SHORTWAVE WILL
BE ENHANCING UPDRAFTS AS WELL.
VERY COOL HIGHS MAY BE IN STORE ON SATURDAY. SPRINGFIELD`S COLDEST
HIGH WAS 67 BACK IN 1891 AND PEORIA`S WAS 71 IN 1980. WE ARE FORECASTING
74 FOR SPRINGFIELD AND 72 FOR PEORIA...BUT IF CLOUD COVER GETS THICK
ENOUGH SAT AFTERNOON...WE COULD SEE SOME RECORD COLD HIGHS SAT
AFTERNOON. DEPENDING ON HOW QUICKLY WE CLEAR OUT SAT NIGHT...WE
COULD SEE A FEW RECORD LOWS REACHED SUNDAY MORNING. THE RECORD LOW
FOR PIA AND SPI IS 53 AND WE ARE FORECASTING 53/PIA AND 54/SPI.
REGARDLESS IF WE HIT RECORDS OR NOT...IT WILL BE A BIG CHANGE FROM
THE HEAT AND HUMIDITY OF JULY 15-19.
SUNDAY MAY SEE A FEW INSTABILITY SHOWERS AS WELL...DUE TO THE
UPPER TROUGH AND COLD POOL LINGERING OVER THE WESTERN GREAT LAKES.
HIGHS SHOULD BE WARMER...BUT STILL IN THE 70S.
LONG TERM...MONDAY THROUGH THURSDAY.
THE EXTENDED MODELS ARE IN DECENT AGREEMENT ON A MORE POTENT LOW
PRESSURE SYSTEM EJECTING FROM THE PLAINS ON MONDAY. IT IS EXPECTED
TO TRIGGER STORMS ON MONDAY NIGHT IN OUR WEST...AND PROGRESS THEM
ACROSS CENTRAL ILLINOIS TUESDAY. SOME STORMS MAY LINGER TUESDAY
EVENING...DEPENDING ON THE ADVANCEMENT OF THE TRAILING COLD FRONT.
THE FRONT MAY END UP BECOMING PARALLEL WITH THE UPPER FLOW BEHIND
THE LOW AND LINGER LONGER THAN THE CANADIAN GEM IS SHOWING. GFS
STALLS OUT A BOUNDARY IN THE AREA INTO WEDNESDAY AS A SECONDARY
SHORTWAVE MOVES EAST FROM KANSAS ACROSS SOUTHERN IL.
THE END RESULT WAS FOR POPS TO GET BUMPED TO LIKELY WEST OF PIA TO
SPI ON MONDAY NIGHT...WITH HIGH CHANCE POPS EAST OF THERE THROUGH
TUESDAY. LOW CHANCE POPS IN THE EAST FOR TUESDAY NIGHT AND IN THE
FAR SOUTHEAST FOR WED WERE MORE TENUOUS. THE SYSTEM HAS
PROGRESSIVE FEATURES WITH THE FASTER UPPER FLOW...SO CONFIDENCE IS
LOW ON POPS AFTER TUESDAY. THURSDAY MAY SEE A FEW SHOWERS AND
STORMS DEVELOP AS THE ZONAL FLOW SENDS VARIOUS SHORTWAVES FROM THE
PLAINS INTO ILLINOIS. WARMER TEMPS WILL DEVELOP NEXT WEEK AS
WELL...ONCE THE CANADIAN AIRMASS SHIFTS TO THE EAST BEGINNING ON
MONDAY.
SHIMON
&&
.AVIATION...
ISSUED 622 PM CDT THU JUL 25 2013
LINE OF THUNDERSTORMS FROM CENTRAL WISCONSIN TO NORTHEAST IOWA AT
23Z WILL CONTINUE TO PUSH EAST-SOUTHEAST. A FAIR AMOUNT OF DRY AIR
IS STILL PROGGED TO BE PRESENT OVER MUCH OF CENTRAL ILLINOIS WELL
INTO THE NIGHT...SO THERE IS SOME QUESTION AS TO HOW FAR IT WILL
MAKE IT. HRRR IS MOST AGGRESSIVE BY BRINGING IT TO KPIA BY 08Z...
BUT MOST OF THE OTHER MODELS HOLD OFF THERE UNTIL AFTER 12Z. FOR
NOW WILL KEEP THE PRECIP OUT OF THE TAFS THROUGH 12Z AND CONTINUE
TO EVALUATE THE LINE OVER THE NEXT FEW HOURS. MAIN PERIOD OF
CONVECTION MOST LIKELY IN ABOUT THE 14-20Z TIME FRAME. THE FRONT
ITSELF SHOULD BEGIN MOVING INTO CENTRAL ILLINOIS TOWARD THE END OF
THE FORECAST PERIOD.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
630 PM CDT THU JUL 25 2013
.SYNOPSIS...
ISSUED AT 311 PM CDT THU JUL 25 2013
12Z UA ANALYSIS HAS AN 850MB LOW NORTHWEST OF LAKE SUPERIOR AND
ANOTHER IN WESTERN NEBRASKA. A WARM FRONT RAN FROM THE NEBRASKA
850MB LOW INTO NORTHWEST IOWA BEFORE TURNING SOUTH. MOISTURE WAS
POOLED IN THE NORTHERN AND CENTRAL PLAINS NEAR THE 850MB LOW AND
WARM FRONT FROM NOCTURNAL STORMS.
SATELLITE TRENDS THROUGH MID AFTERNOON SHOW NEW CONVECTION HAS
DEVELOPED FROM SOUTHERN MINNESOTA INTO WESTERN WISCONSIN ALONG WITH
A PERSISTENT CLUSTER OF STORMS FROM NEBRASKA INTO NORTHEAST KANSAS.
18Z SFC ANALYSIS HAS WEAK LOWS FROM SOUTHWEST MINNESOTA INTO
SOUTHERN SOUTH DAKOTA WITH A SLIGHTLY STRONGER LOW IN EASTERN
COLORADO. A WARM FRONT RAN FROM NORTHWEST KANSAS INTO LOUISIANA. DEW
POINTS WERE IN THE 50S ACROSS THE GREAT LAKES WITH 60S FROM
WISCONSIN INTO THE PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 311 PM CDT THU JUL 25 2013
SATELLITE AND RADAR TRENDS SHOW CONVECTION NORTH OF THE CWFA AND
WELL SOUTHWEST OF THE CWFA. THE RAP TRENDS AND OTHER MODELS OF A
POSSIBLE SCENARIO OF CONVECTION NORTHEAST AND SOUTHWEST OF THE CWFA
TONIGHT MAY BE STARTING TO PLAY OUT. HOWEVER...RADAR DOES SHOW WEAK
CONVECTION DEVELOPING ACROSS NORTHERN IOWA AND ALONG THE MISSOURI
RIVER NEAR KOMA. THE MCS TOOL SUGGESTS ISOLATED TO SCATTERED
CONVECTION MOVING/DEVELOPING ACROSS THE NORTHWEST CWFA DURING THE
EVENING AND POSSIBLY BECOMING LOOSELY ORGANIZED LATE TONIGHT.
THE SIGNAL FOR A SUBSTANTIAL MCS DEVELOPING IN THE PLAINS AND
DROPPING SOUTHEAST OVERNIGHT IS STILL THERE IN ALL THE MODELS. IF
CORRECT...THIS MCS WOULD INTERCEPT THE MOISTURE INFLOW INTO THE AREA
AND THUS LIMIT THE POTENTIAL FOR RAIN. THOSE AREAS THAT DO SEE RAIN
OVERNIGHT MAY SEE AMOUNTS RANGING FROM 0.25 TO 0.50 INCHES.
CONVECTION THAT DEVELOPS TONIGHT WILL BE ACROSS THE AREA FRIDAY
MORNING WITH THE BETTER CHANCES OVER THE NORTHEAST CWFA WHERE BETTER
FORCING EXISTS. THE RAIN WILL END FROM WEST TO EAST DURING THE DAY
AS THE FRONT MOVES THROUGH WITH LINGERING CONVECTION OVER THE
SOUTHEAST HALF OF THE CWFA BY LATE AFTERNOON. CLOUD COVER MAY
INITIALLY SUPPRESS TEMPERATURES DURING THE DAY BUT CLEARING IN THE
AFTERNOON SHOULD PUSH TEMPERATURES INTO THE 75 TO 80 DEGREE
RANGE. ..08..
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 311 PM CDT THU JUL 25 2013
A CLOSED UPPER LOW WILL REMAIN OVER THE WESTERN GREAT LAKES THROUGH
LATE SATURDAY THEN MOVES SLOWLY EAST REACHING NORTHERN MICHIGAN BY
SUNDAY EVENING. THE COLD FRONT ASSOCIATED WITH THE UPPER LOW SHOULD BE
NEAR THE MISSISSIPPI RIVER BY 00Z SATURDAY AND EAST OF THE FORECAST
AREA BY 06Z SATURDAY WITH BEST MID/UPPER FORCING AHEAD OF THE UPPER
TROF SHIFTING EAST OF THE FORECAST AREA BY 06Z. THIS SUPPORTS
THE GOING FORECAST OF SLIGHT CHANCE POPS EAST FRIDAY EVENING THEN
DRY AFTER MIDNIGHT. THE REST OF THE WEEKEND LOOKS DRY WITH NORTH TO
NORTHWEST FLOW DOMINATING THE REGION. SATURDAY AFTERNOON/EVENING
WILL HAVE TO WATCH THE NORTHEASTERN CWFA FOR POTENTIAL DIURNAL SHRA
AS THE H5 COLD POOL MOVES THROUGH. NEAR RECORD TEMPS FOR SATURDAY
AND SUNDAY MORNING STILL LOOK ON TRACK. KEPT SATURDAYS LOWS ON THE
WARM SIDE OF GUIDANCE WITH THE POTENTIAL FOR SOME COLD AIR SC MOVING
THE THROUGH FRIDAY NIGHT. FORECAST MINS FOR SATURDAY STAY JUST ABOVE
THE RECORDS. SUNDAY LIGHTER SURFACE WINDS AND LESS OF THREAT OF
SIGNIFICANT CLOUD COVER SUPPORTS COOLER MINS THAN SATURDAY AND A
BETTER POTENTIAL OF REACHING RECORD MINS. THE COOL AIRMASS WILL
KEEP HIGHS SATURDAY AND SUNDAY IN THE LOW TO MID 70S. NORMALS HIGHS
FOR LATE JULY ARE IN THE LOW TO MID 80S.
THE GREAT LAKES REGION UPPER LOW WILL DRIFT NORTHEAST INTO EASTERN
CANADA BY MID TO LATE WEEK AS WESTERLY MID LEVEL FLOW SPREADS EAST
INTO THE CENTRAL U.S. A S/W ON THE LEADING EDGE OF THE WESTERLY
FLOW REGIME IS PROGGED TO MOVE THROUGH THE CENTRAL U.S. MONDAY AND
TUESDAY. MODELS ARE IN GOOD AGREEMENT DEVELOPING A PLAINS MCS IN
THE RETURN FLOW AHEAD OF THE S/W AND MOVING THE MCS EAST INTO THE
MID MISSISSIPPI VALLEY LATE MONDAY NIGHT OR TUESDAY. THE 12Z
GFS/GEM BROUGHT THE BULK OF THE PRECIP WITH THIS SYSTEM THROUGH IA
AND NORTHERN ILLINOIS WHILE THE 12Z ECMWF WAS A TAD SOUTH FOCUSING
MORE ON NORTHERN MO AND SOUTHERN IA INTO CENTRAL AND SOUTHERN IL.
WITH ALL OF THE MODELS HITTING SOME PART OF THE FORECAST AREA HAVE
UPPED POPS TO HIGH CHANCE OR LIKELY WITH THE HIGHEST POPS MONDAY
NIGHT. THE GFS/ECMWF SUGGEST ANOTHER S/W MOVING THROUGH BY THURSDAY
BUT THE FEATURES LOOK WEAK AT THIS TIME SO SLIGHT CHANCE OR LOW
CHANCE POPS ARE MENTIONED FOR NOW. TEMPERATURES WILL BE ON A
GRADUAL WARMING TREND THROUGH THE WEEK AND SHOULD BE BACK TO NEAR
NORMAL FOR EARLY AUGUST BY WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 606 PM CDT THU JUL 25 2013
THUNDERSTORMS AHEAD OF AN APPROACHING COLD FRONT WILL PRODUCE
AREAS OF MVFR TO LOCALLY IFR CONDITIONS TONIGHT...ESPECIALLY
BETWEEN 02Z AND 15Z. THE COLD FRONT WILL CROSS THE AREA THROUGH
THE DAY FRIDAY...SHIFTING SURFACE AND LOW LEVEL WINDS FROM THE
SOUTH TO THE NORTH AND PUSHING THUNDERSTORMS OUT OF THE AREA.
&&
.CLIMATE...
ISSUED AT 311 PM CDT THU JUL 25 2013
RECORD LOWS FOR JULY 27...
MOLINE.........50 IN 1962+
CEDAR RAPIDS...48 IN 1937
DUBUQUE........48 IN 1971
BURLINGTON.....49 IN 2004+
RECORD LOWS FOR JULY 28...
MOLINE.........52 IN 1925
CEDAR RAPIDS...47 IN 1925
DUBUQUE........51 IN 2005+
BURLINGTON.....53 IN 1981
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DLF
AVIATION...DMD
CLIMATE...14
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1239 PM CDT WED JUL 24 2013
.UPDATE...
ISSUED AT 1001 AM CDT WED JUL 24 2013
SATELLITE HAS A RESPECTABLE SHORTWAVE DROPPING SOUTHEAST INTO
IOWA. THE SLIGHTLY BETTER LIFT IS ACROSS MINNESOTA WERE SOME
SHOWERS WERE OCCURRING AROUND KSTC. THIS PRECIPITATION AND THE
SPRINKLES AT KDEH ARE IN AN AREA OF CONVERGENCE AND ISENTROPIC
LIFT.
THE RAP TRENDS INDICATE THIS ISENTROPIC LIFT WILL TURN MORE INTO
DOWN GLIDE AS THE LATE MORNING AND AFTERNOON PROGRESS ACROSS THE
AREA. THUS THE CLOUDS ASSOCIATED WITH THE SHORTWAVE SHOULD THIN
WITH TIME. HOWEVER...THE VERY WEAK CONVERGENCE WILL PERSIST
THROUGH MID AFTERNOON SO ONE CANNOT RULE OUT ISOLATED POCKETS OF
SPRINKLES. THERE SHOULD BE A FAIR AMOUNT OF VIRGA ASSOCIATED WITH
THE CLOUDS. ..08..
&&
.SYNOPSIS...
ISSUED AT 338 AM CDT WED JUL 24 2013
CANADIAN HIGH PRESSURE OVER ND AND NORTHERN MN WAS THE DOMINANT
SURFACE FEATURE OVER THE REGION EARLY THIS MORNING. RESULTING DRY
AIR AND SUBSIDENCE WAS RESULTING IN MOSTLY CLEAR SKIES ACROSS THE
NORTHERN HALF OF THE FORECAST AREA. ACROSS THE SOUTH...SATELLITE
IMAGERY REVEALED A DECK OF AC EXPANDING ACROSS SE IA INTO W CENTRAL
IL AND A SHIELD OF CI...ASSOCIATED WITH A VERY LARGE MCS OVER OK
AND AR...REACHING INTO FAR NORTHEAST MO. LIGHT NE WINDS WERE
ADVECTING DEWPOINTS IN THE 50S INTO THE AREA...WHILE TEMPERATURES
WERE COOLING TOWARD ANTICIPATED LOWS IN THE LOWER 50S NORTHEAST TO
NEAR 60 IN THE FAR SOUTH. ALOFT...A NW FLOW BETWEEN A CENTRAL
ROCKIES RIDGE AND TROUGH OVER THE EASTERN U.S. REMAINED IN PLACE.
THE NEXT UPSTREAM SHORTWAVE WAS MOVING ACROSS SOUTH DAKOTA...ON A
TRACK TO MOVE THROUGH THE FORECAST AREA TODAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT WED JUL 24 2013
THE MAIN FOCUS IS ON CONTINUED BELOW NORMAL TEMPERATURES AS HIGH
PRESSURE KEEPS A COOL...DRY AIRMASS IN PLACE. THE HIGH PRESSURE
RIDGE IS EXPECTED TO PASS TO THE NORTHEAST TO EXTEND FROM LOWER MI
SW INTO MO BY THURSDAY MORNING. WHILE THIS WILL PROVIDE LOW LEVEL
SUBSIDENCE AND A FEED OF DRY AIR ON LIGHT EAST TO NORTHEAST
WINDS. AN ACTIVE UPPER LEVEL NW FLOW AND THE EMBEDDED SHORTWAVE
AND AXIS OF MID LEVEL MOISTURE MOVING OUT OF THE NORTHERN PLAINS
WILL LIKELY RESULT IN PASSING MID LEVEL CLOUDS THAT COULD BE
RATHER EXTENSIVE AROUND LATE MORNING THROUGH EARLY AFTERNOON OVER
ESPECIALLY THE NORTH. THE LIMITED INSOLATION DURING PEAK
HEATING...ALONG WITH A MORE EASTERLY SURFACE WIND COMPONENT AND
COOLER MORNING START SUPPORTS SLIGHTLY COOLER HIGHS THAN YESTERDAY
AND HAVE STAYED WITH A RANGE FROM THE LOWER 70S NORTH TO UPPER 70S
SOUTH. MODEST MID LEVEL LIFT MAY AGAIN LEAD TO HIGH BASED SHOWERS
OVER THE ESPECIALLY THE NORTH IN THE AFTERNOON...BUT MUCH LIKE
YESTERDAY...WILL KEEP A DRY FORECAST ANTICIPATING LITTLE MORE THAN
VIRGA.
TONIGHT...MID LEVEL SUBSIDENCE IS SHOWN OVERSPREADING THE
REGION...WHICH ALONG WITH THE PASSING SURFACE RIDGE AXIS SHOULD
PROVIDE MOSTLY CLEAR SKIES AND LIGHT WINDS. MIN TEMPERATURES FROM
THE PREVIOUS FORECAST IN MID TO UPPER 50S LOOK ON TRACK AND ONLY
MINOR TWEAKS WERE MADE. THESE VALUES WOULD BE ROUGHLY A CATEGORY
ABOVE RECORD LOWS FOR THE 25TH...WHICH ARE INCLUDED IN THE CLIMATE
SECTION BELOW FOR REFERENCE. CANNOT RULE OUT GROUND FOG AS WINDS
WILL BE LIGHT TO NEARLY CALM TOWARD SUNRISE...BUT DO NOT EXPECT
ENOUGH COVERAGE OR IMPACTS TO WARRANT MENTION IN THE FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CDT WED JUL 24 2013
FOCUS IN THE EXTENDED IS ON TIMING AND AMOUNTS OF PCPN CHANCES FOR
THURSDAY NIGHT THROUGH FRIDAY NIGHT. TWO SEPARATE AREAS OF LOW
PRESSURE...ONE MOVING ACROSS THE UPPER MS RIVER VALLEY AND THE OTHER
IN THE SOUTHERN PLAINS...WILL INTERACT WITH ONE ANOTHER AS THE
NORTHERN LOW SWEEPS A COLD FRONT THROUGH THE AREA ON FRIDAY. THE
SOUTHERN SYSTEM MAY STEAL SOME ENERGY/MOISTURE AS MODELS SHOW IT TO
MOVE ESE ACROSS CENTRAL/SOUTHERN MO. DO BELIEVE MOST AREAS/NW TWO
THIRDS/ WILL SEE A GOOD CHANCE /50POP/ OF RAIN BUT AM NOW THINKING
THAT THE ENERGY/PCPN MAY BE SHEARING OUT AS THE FRONT MOVES INTO THE
SE THIRD OF THE CWFA AND THE SOUTHERN LOW FOCUS/S HEAVIER RAINS
ACROSS MO. THUS LEFT LOWER 35-40 POPS AND PCPN AMOUNTS IN SE.
STEPPED OUT PCPN CHANCES FRIDAY EVENING...WITH LINGERING SLIGHT
CHANCES IN SE AFTER MIDNIGHT. THIS MAY BE TOO SLOW AND ALL PCPN MAY
BE DONE BY LATE EVENING. ALL IN ALL...RAINFALL TOTALS LOOK TO RANGE
FROM AROUND A THIRD OF AN INCH IN THE NW...TO A TENTH OF AN INCH SE.
SEASONABLY COOL AND DRY CONDITIONS WILL BE FOUND ACROSS THE AREA FOR
THE WEEKEND.
TEMPERATURES WILL BE IN THE UPPER 70S/LOWER 80S ON THURSDAY...WITH
MID 70S TO LOWER 80S ON FRIDAY AS SHOWERS AND STORMS MOVE THROUGH.
MILD LOWS THURSDAY NIGHT /L-M 60S/ AS MOISTURE BUILDS AHEAD OF
FRONT. BEHIND THE FRONT MUCH COOLER AIR IS FOUND. SATURDAY MORNING
LOWS WILL SLIP INTO LOWER 50S NW TO NEAR 60 SE...WITH HIGHS SATURDAY
AFTERNOON STRUGGLING TO REACH 70 NORTH TO THE UPPER 70S SOUTH.
SUNDAY AM LOWS LOOKS TO BE COLDEST...WITH READINGS GENERALLY 53-58
DEGREES.
A GRADUAL WARM UP BEGINS SUN THROUGH TUE WITH HIGHS IN THE MID 70S
TO LOWER 80.
THE NEXT CHANCE FOR RAIN COMES IN MONDAY THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1234 PM CDT WED JUL 24 2013
A FEW POCKETS OF MVFR CIGS DEVELOPED WITH THE DIURNAL CUMULUS ACROSS
IOWA. MOST CIGS ARE ABOVE 3KFT AGL. THUS VFR WX WILL CONTINUE
THROUGH 06Z/25 WITH HIGH PRESSURE ACROSS THE AREA. AFT 06Z/25 THE
POTENTIAL EXISTS FOR SHALLOW GROUND FOG TO DEVELOP. MVFR VSBYS AND
BLO 0.5KFT AGL CLOUDS WERE INTRODUCED PRIOR TO SUNRISE IN THE 18Z
TAFS. ..08..
&&
.CLIMATE...
ISSUED AT 338 AM CDT WED JUL 24 2013
RECORD LOWS FOR JULY 25...
MOLINE.........52 IN 1933
CEDAR RAPIDS...50 IN 2004
DUBUQUE........50 IN 2004
BURLINGTON.....53 IN 1911
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...14
AVIATION...08
CLIMATE...SHEETS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1006 AM CDT WED JUL 24 2013
.UPDATE...
ISSUED AT 1001 AM CDT WED JUL 24 2013
SATELLITE HAS A RESPECTABLE SHORTWAVE DROPPING SOUTHEAST INTO
IOWA. THE SLIGHTLY BETTER LIFT IS ACROSS MINNESOTA WERE SOME
SHOWERS WERE OCCURRING AROUND KSTC. THIS PRECIPITATION AND THE
SPRINKLES AT KDEH ARE IN AN AREA OF CONVERGENCE AND ISENTROPIC
LIFT.
THE RAP TRENDS INDICATE THIS ISENTROPIC LIFT WILL TURN MORE INTO
DOWN GLIDE AS THE LATE MORNING AND AFTERNOON PROGRESS ACROSS THE
AREA. THUS THE CLOUDS ASSOCIATED WITH THE SHORTWAVE SHOULD THIN
WITH TIME. HOWEVER...THE VERY WEAK CONVERGENCE WILL PERSIST
THROUGH MID AFTERNOON SO ONE CANNOT RULE OUT ISOLATED POCKETS OF
SPRINKLES. THERE SHOULD BE A FAIR AMOUNT OF VIRGA ASSOCIATED WITH
THE CLOUDS. ..08..
&&
.SYNOPSIS...
ISSUED AT 338 AM CDT WED JUL 24 2013
CANADIAN HIGH PRESSURE OVER ND AND NORTHERN MN WAS THE DOMINANT
SURFACE FEATURE OVER THE REGION EARLY THIS MORNING. RESULTING DRY
AIR AND SUBSIDENCE WAS RESULTING IN MOSTLY CLEAR SKIES ACROSS THE
NORTHERN HALF OF THE FORECAST AREA. ACROSS THE SOUTH...SATELLITE
IMAGERY REVEALED A DECK OF AC EXPANDING ACROSS SE IA INTO W CENTRAL
IL AND A SHIELD OF CI...ASSOCIATED WITH A VERY LARGE MCS OVER OK
AND AR...REACHING INTO FAR NORTHEAST MO. LIGHT NE WINDS WERE
ADVECTING DEWPOINTS IN THE 50S INTO THE AREA...WHILE TEMPERATURES
WERE COOLING TOWARD ANTICIPATED LOWS IN THE LOWER 50S NORTHEAST TO
NEAR 60 IN THE FAR SOUTH. ALOFT...A NW FLOW BETWEEN A CENTRAL
ROCKIES RIDGE AND TROUGH OVER THE EASTERN U.S. REMAINED IN PLACE.
THE NEXT UPSTREAM SHORTWAVE WAS MOVING ACROSS SOUTH DAKOTA...ON A
TRACK TO MOVE THROUGH THE FORECAST AREA TODAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT WED JUL 24 2013
THE MAIN FOCUS IS ON CONTINUED BELOW NORMAL TEMPERATURES AS HIGH
PRESSURE KEEPS A COOL...DRY AIRMASS IN PLACE. THE HIGH PRESSURE
RIDGE IS EXPECTED TO PASS TO THE NORTHEAST TO EXTEND FROM LOWER MI
SW INTO MO BY THURSDAY MORNING. WHILE THIS WILL PROVIDE LOW LEVEL
SUBSIDENCE AND A FEED OF DRY AIR ON LIGHT EAST TO NORTHEAST
WINDS. AN ACTIVE UPPER LEVEL NW FLOW AND THE EMBEDDED SHORTWAVE
AND AXIS OF MID LEVEL MOISTURE MOVING OUT OF THE NORTHERN PLAINS
WILL LIKELY RESULT IN PASSING MID LEVEL CLOUDS THAT COULD BE
RATHER EXTENSIVE AROUND LATE MORNING THROUGH EARLY AFTERNOON OVER
ESPECIALLY THE NORTH. THE LIMITED INSOLATION DURING PEAK
HEATING...ALONG WITH A MORE EASTERLY SURFACE WIND COMPONENT AND
COOLER MORNING START SUPPORTS SLIGHTLY COOLER HIGHS THAN YESTERDAY
AND HAVE STAYED WITH A RANGE FROM THE LOWER 70S NORTH TO UPPER 70S
SOUTH. MODEST MID LEVEL LIFT MAY AGAIN LEAD TO HIGH BASED SHOWERS
OVER THE ESPECIALLY THE NORTH IN THE AFTERNOON...BUT MUCH LIKE
YESTERDAY...WILL KEEP A DRY FORECAST ANTICIPATING LITTLE MORE THAN
VIRGA.
TONIGHT...MID LEVEL SUBSIDENCE IS SHOWN OVERSPREADING THE
REGION...WHICH ALONG WITH THE PASSING SURFACE RIDGE AXIS SHOULD
PROVIDE MOSTLY CLEAR SKIES AND LIGHT WINDS. MIN TEMPERATURES FROM
THE PREVIOUS FORECAST IN MID TO UPPER 50S LOOK ON TRACK AND ONLY
MINOR TWEAKS WERE MADE. THESE VALUES WOULD BE ROUGHLY A CATEGORY
ABOVE RECORD LOWS FOR THE 25TH...WHICH ARE INCLUDED IN THE CLIMATE
SECTION BELOW FOR REFERENCE. CANNOT RULE OUT GROUND FOG AS WINDS
WILL BE LIGHT TO NEARLY CALM TOWARD SUNRISE...BUT DO NOT EXPECT
ENOUGH COVERAGE OR IMPACTS TO WARRANT MENTION IN THE FORECAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 338 AM CDT WED JUL 24 2013
FOCUS IN THE EXTENDED IS ON TIMING AND AMOUNTS OF PCPN CHANCES FOR
THURSDAY NIGHT THROUGH FRIDAY NIGHT. TWO SEPARATE AREAS OF LOW
PRESSURE...ONE MOVING ACROSS THE UPPER MS RIVER VALLEY AND THE OTHER
IN THE SOUTHERN PLAINS...WILL INTERACT WITH ONE ANOTHER AS THE
NORTHERN LOW SWEEPS A COLD FRONT THROUGH THE AREA ON FRIDAY. THE
SOUTHERN SYSTEM MAY STEAL SOME ENERGY/MOISTURE AS MODELS SHOW IT TO
MOVE ESE ACROSS CENTRAL/SOUTHERN MO. DO BELIEVE MOST AREAS/NW TWO
THIRDS/ WILL SEE A GOOD CHANCE /50POP/ OF RAIN BUT AM NOW THINKING
THAT THE ENERGY/PCPN MAY BE SHEARING OUT AS THE FRONT MOVES INTO THE
SE THIRD OF THE CWFA AND THE SOUTHERN LOW FOCUS/S HEAVIER RAINS
ACROSS MO. THUS LEFT LOWER 35-40 POPS AND PCPN AMOUNTS IN SE.
STEPPED OUT PCPN CHANCES FRIDAY EVENING...WITH LINGERING SLIGHT
CHANCES IN SE AFTER MIDNIGHT. THIS MAY BE TOO SLOW AND ALL PCPN MAY
BE DONE BY LATE EVENING. ALL IN ALL...RAINFALL TOTALS LOOK TO RANGE
FROM AROUND A THIRD OF AN INCH IN THE NW...TO A TENTH OF AN INCH SE.
SEASONABLY COOL AND DRY CONDITIONS WILL BE FOUND ACROSS THE AREA FOR
THE WEEKEND.
TEMPERATURES WILL BE IN THE UPPER 70S/LOWER 80S ON THURSDAY...WITH
MID 70S TO LOWER 80S ON FRIDAY AS SHOWERS AND STORMS MOVE THROUGH.
MILD LOWS THURSDAY NIGHT /L-M 60S/ AS MOISTURE BUILDS AHEAD OF
FRONT. BEHIND THE FRONT MUCH COOLER AIR IS FOUND. SATURDAY MORNING
LOWS WILL SLIP INTO LOWER 50S NW TO NEAR 60 SE...WITH HIGHS SATURDAY
AFTERNOON STRUGGLING TO REACH 70 NORTH TO THE UPPER 70S SOUTH.
SUNDAY AM LOWS LOOKS TO BE COLDEST...WITH READINGS GENERALLY 53-58
DEGREES.
A GRADUAL WARM UP BEGINS SUN THROUGH TUE WITH HIGHS IN THE MID 70S
TO LOWER 80.
THE NEXT CHANCE FOR RAIN COMES IN MONDAY THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 605 AM CDT WED JUL 24 2013
HIGH PRESSURE WILL PROVIDE DRY WEATHER WITH LIGHT EAST TO
SOUTHEAST WINDS TODAY AND TONIGHT. A WEAK UPPER LEVEL DISTURBANCE
WILL SEND MID AND HIGH LEVEL CLOUDS ACROSS THE AREA FROM MID
MORNING THROUGH EARLY AFTERNOON. SOME GROUND FOG WILL BE POSSIBLE
TOWARD SUNRISE THURSDAY MORNING. FOR NOW...THIS IS HANDLED WITH
TEMPO GROUPS AND MVFR VISIBILITIES.
&&
.CLIMATE...
ISSUED AT 338 AM CDT WED JUL 24 2013
RECORD LOWS FOR JULY 25...
MOLINE.........52 IN 1933
CEDAR RAPIDS...50 IN 2004
DUBUQUE........50 IN 2004
BURLINGTON.....53 IN 1911
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...14
AVIATION...SHEETS
CLIMATE...SHEETS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
208 AM CDT WED JUL 24 2013
...UPDATED LONG TERM SECTION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUL 23 2013
TONIGHT:
NEAR TERM FORECAST CONCERN IS CONVECTION THIS AFTERNOON/EVENING. WSR-
88D AND SURFACE OBSERVATIONS SHOW A FEW BOUNDARIES ACROSS THE REGION
THIS AFTERNOON. ONE IS A "COLD FRONT"/OUTFLOW BOUNDARY THIS IS ROUGHLY
LOCATED FROM NESS CITY SE TO PRATT. A NONDESCRIPT DRYLINE IS THE OTHER
BOUNDARY FARTHER WEST. THE INTERSECTION OF THESE TWO DENSITY GRADIENTS
SHOULD BE WHERE CONVECTION INITIATES. THE MOST RECENT HRRR IS SHOWING
AN ISOLATED STORM DEVELOPING JUST NORTHEAST OF DODGE CITY (MUCH LIKE
YESTERDAY) AND THEN INDICATING THIS ACTIVITY DRIFTING OFF TO THE SE AS THE
EARLY EVENING WEARS ON. THE NAM IS IN FAIR AGREEMENT WITH THIS SOLUTION.
THE STORMS MAY BECOME SEVERE AS WELL AS 1-8 KM BULK SHEAR IS STRONGER
THAN YESTERDAY...PLUS DEWPOINTS ARE STILL RUNNING FAIRLY HIGH, WHICH
WILL CREATE ABOUT 1500-2000 J/KG OF SBCAPE. MODELS ALSO SHOW SOME DCAPE
AS THE ATMOSPHERE BECOMES WELL MIXED. AS A RESULT, HAVE TWEAKED THE
HWO WITH THE THREATS OF QUARTER SIZE HAIL, 60 MPH OUTFLOW, AND LIGHTNING
AS THE MAIN CONCERNS. THIS ACTIVITY WILL CLEAR THE AREA LATER THIS EVENING
AS THE FRONT SINKS SOUTHWARD. OVERNIGHT LOWS WILL BE IN THE 60S DEG
F AND 70S DEG F. UPSLOPE STRATUS WILL BE POSSIBLE ON THE BACKSIDE OF
THE LOW LEVEL PRESSURE PERTURBATION WITH UPSLOPE WINDS IN THE SFC-850
HPA LAYER.
TOMORROW:
AN UPSLOPE FLOW PATTERN IS EXPECTED TOMORROW IN THE WAKE OF THE AFOREMENTIONED
BOUNDARY. MAXIMUMS WILL BE "COOLER" THAN COMPARED TO TODAY WITH VALUES
IN THE UPPER 80S DEG F TO LOWER 90S DEG F. 23.12Z NAM SOLUTION IS WARMER
COMPARED TO OTHER GUIDANCE, BUT THIS MIGHT BE A BIT OVERDONE. WILL USE
THE ECMWF FOR NOW. OROGRAPHIC CONVECTION IS POSSIBLE IN THE UPSLOPE
FLOW REGIME TOMORROW ACROSS EASTERN COLORADO. WILL CARRY SLIGHT PRECIPITATION
PROBABILITY PERCENTAGE POINTS FOR FAR WEST KANSAS THROUGH 00Z TOMORROW
NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 206 AM CDT WED JUL 24 2013
AN UPPER LEVEL SHORTWAVE WILL MOVE FROM THE CENTRAL ROCKIES
WEDNESDAY INTO THE CENTRAL PLAINS ON THURSDAY. THIS WILL BRING
INCREASED MOISTURE TO THE MID AND UPPER LEVELS OF THE ATMOSPHERE.
MEANWHILE AT THE SURFACE, A STATIONARY FRONT WILL BE LOCATED OVER
THE SOUTHERN PLAINS, WITH UPSLOPE FLOW AND ABUNDANT LOW LEVEL
MOISTURE ON THE COOL SIDE OF THE FRONT OVER WESTERN KANSAS. A GOOD
CHANCE OF THUNDERSTORMS ARE EXPECTED ON THURSDAY INTO THURSDAY NIGHT
AS THIS SYSTEM MOVES THROUGH THE AREA. OTHERWISE EXPECTED CLOUDY
SKIES ON THURSDAY AND THURSDAY NIGHT. THE BEST CHANCE OF
THUNDERSTORMS WILL BE THURSDAY AFTERNOON INTO THURSDAY EVENING. THIS
IS ALSO WHEN A FEW STORMS COULD BECOME SEVERE WITH DAMAGING WINDS
AND LARGE HAIL BEING THE MAIN CONCERN. WITH A VEERING SHEAR PROFILE
AND ABUNDANT LOW LEVEL MOISTURE AN ISOLATED TORNADO WILL ALSO BE
POSSIBLE. HIGHS THURSDAY ARE FORECASTED TO RANGE FROM THE LOWER 80S
ACROSS WEST CENTRAL KANSAS TO AROUND 90 DEGREES ACROSS THE KS/OK
BORDER. LOWS FRIDAY MORNING WILL GENERALLY BE IN THE 60S.
THE AFOREMENTIONED SYSTEM SHIFTS EAST OF THE AREA ON FRIDAY WITH
PRECIPITATION CHANCES CONTINUING ACROSS CENTRAL KANSAS IN THE
MORNING WHICH CLEARING SKIES FROM WEST TO EAST. A BREAK IN
PRECIPITATION IS EXPECTED FRIDAY AND SATURDAY, WITH CONTINUED COOL
WEATHER BY THE WEEKEND, THE MID TO UPPER LEVEL FLOW WILL BECOME MORE
WEST-NORTHWESTERLY AGAIN, RESULTING IN RENEWED WEAK SURFACE LEE
TROUGHING AND WARM/MOIST ADVECTION INTO WESTERN KANSAS. THEREFORE,
THERE ARE CHANCES OF THUNDERSTORMS AGAIN BY SATURDAY NIGHT INTO
TUESDAY. HIGHS WILL GENERALLY BE IN THE MID TO UPPER 80S FRIDAY
THROUGH SUNDAY WITH LOWER 90S EXPECTED MONDAY AND TUESDAY. LOWS LOOK
TO DIP INTO THE 60S SATURDAY AND SUNDAY MORNING BEFORE WARMING TO
AROUND 70 DEGREES SUNDAY AND MONDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1223 AM CDT WED JUL 24 2013
VFR CONDITIONS WILL BE THE RULE TODAY, ALONG WITH NORTHEAST WINDS
OF 11G22KT. THERE IS A CHANCE FOR A LITTLE 5SM BKN025 CONDITIONS
TOWARD SUNRISE, BUT THOSE CONDITIONS SHOULD NOT LAST PAST 13Z OR
SO. WINDS LATER TODAY WILL BE NORTHEAST AT 15G25KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 91 69 86 67 / 10 40 60 60
GCK 90 68 86 66 / 10 50 60 50
EHA 91 66 87 65 / 20 50 50 40
LBL 93 69 89 67 / 10 40 60 50
HYS 88 68 84 66 / 10 40 50 50
P28 90 71 89 69 / 10 40 60 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...HOVORKA_42
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1227 AM CDT WED JUL 24 2013
...UPDATED FOR THE 06Z TAFS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 925 AM CDT TUE JUL 23 2013
THE 23.12Z 250 HPA RAOB MAP SHOWED WESTERLY TO NORTHWESTERLY FLOW STRETCHING
FROM OREGON TO THE MIDWEST. MAGNITUDES WERE 50-75 KT. @ 500 HPA, AN
ELONGATED 592/593 DM ANTICYCLONE EXTENDED FROM NORTHERN NEVADA SE TO
NW NEW MEXICO. DOWNSTREAM, A BROAD TROF WAS MOVING ACROSS THE EASTERN
UNITED STATES. @ 700 HPA, 2 DEG C OF WARMING OCCURRED AT KDDC BETWEEN
22.12Z AND 23.12Z SYNOPTIC FLIGHTS AND AT A FAIRLY WARM TEMP OF 15
DEG C THIS MORNING. @ 850 HPA, KDDC WAS AT 26 DEG C, WHICH IS ABOVE
THE 75TH PERCENTILE. AT THE SFC, A LOW PRESSURE CENTER WAS LOCATED ACROSS
FAR SW KANSAS. AN OUTFLOW BOUNDARY WAS DRAPED ACROSS THE FORECAST AREA
OF RESPONSIBILITY. INVEST 98E WAS LOCATED 800 MILES SSW OF THE SOUTHERN
TIP OF BAJA CALIFORNIA. INVEST 98L WAS LOCATED A COUPLE HUNDRED MILES
SSE OF THE CAPE VERDE ISLANDS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 200 PM CDT TUE JUL 23 2013
TONIGHT:
NEAR TERM FORECAST CONCERN IS CONVECTION THIS AFTERNOON/EVENING. WSR-
88D AND SURFACE OBSERVATIONS SHOW A FEW BOUNDARIES ACROSS THE REGION
THIS AFTERNOON. ONE IS A "COLD FRONT"/OUTFLOW BOUNDARY THIS IS ROUGHLY
LOCATED FROM NESS CITY SE TO PRATT. A NONDESCRIPT DRYLINE IS THE OTHER
BOUNDARY FARTHER WEST. THE INTERSECTION OF THESE TWO DENSITY GRADIENTS
SHOULD BE WHERE CONVECTION INITIATES. THE MOST RECENT HRRR IS SHOWING
AN ISOLATED STORM DEVELOPING JUST NORTHEAST OF DODGE CITY (MUCH LIKE
YESTERDAY) AND THEN INDICATING THIS ACTIVITY DRIFTING OFF TO THE SE AS THE
EARLY EVENING WEARS ON. THE NAM IS IN FAIR AGREEMENT WITH THIS SOLUTION.
THE STORMS MAY BECOME SEVERE AS WELL AS 1-8 KM BULK SHEAR IS STRONGER
THAN YESTERDAY...PLUS DEWPOINTS ARE STILL RUNNING FAIRLY HIGH, WHICH
WILL CREATE ABOUT 1500-2000 J/KG OF SBCAPE. MODELS ALSO SHOW SOME DCAPE
AS THE ATMOSPHERE BECOMES WELL MIXED. AS A RESULT, HAVE TWEAKED THE
HWO WITH THE THREATS OF QUARTER SIZE HAIL, 60 MPH OUTFLOW, AND LIGHTNING
AS THE MAIN CONCERNS. THIS ACTIVITY WILL CLEAR THE AREA LATER THIS EVENING
AS THE FRONT SINKS SOUTHWARD. OVERNIGHT LOWS WILL BE IN THE 60S DEG
F AND 70S DEG F. UPSLOPE STRATUS WILL BE POSSIBLE ON THE BACKSIDE OF
THE LOW LEVEL PRESSURE PERTURBATION WITH UPSLOPE WINDS IN THE SFC-850
HPA LAYER.
TOMORROW:
AN UPSLOPE FLOW PATTERN IS EXPECTED TOMORROW IN THE WAKE OF THE AFOREMENTIONED
BOUNDARY. MAXIMUMS WILL BE "COOLER" THAN COMPARED TO TODAY WITH VALUES
IN THE UPPER 80S DEG F TO LOWER 90S DEG F. 23.12Z NAM SOLUTION IS WARMER
COMPARED TO OTHER GUIDANCE, BUT THIS MIGHT BE A BIT OVERDONE. WILL USE
THE ECMWF FOR NOW. OROGRAPHIC CONVECTION IS POSSIBLE IN THE UPSLOPE
FLOW REGIME TOMORROW ACROSS EASTERN COLORADO. WILL CARRY SLIGHT PRECIPITATION
PROBABILITY PERCENTAGE POINTS FOR FAR WEST KANSAS THROUGH 00Z TOMORROW
NIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 353 PM CDT TUE JUL 23 2013
THE SYSTEM THAT MOVED WESTWARD ALONG THE SOUTHERN EDGE OF THE UPPER
LEVEL RIDGE LAST WEEK WAS LOCATED NEAR THE CALIFORNIA COAST TODAY AND
IS POISED TO MOVE BACK EASTWARD ON THE NORTHERN SIDE OF THE UPPER
LEVEL RIDGE. BY WEDNESDAY NIGHT AND THURSDAY, THIS SYSTEM WILL BE
APPROACHING FROM THE WEST. A STATIONARY FRONT WILL BE LOCATED
OVER THE SOUTHERN PLAINS, WITH UPSLOPE FLOW AND ABUNDANT LOW LEVEL
MOISTURE ON THE COOL SIDE OF THE FRONT OVER WESTERN KANSAS. WE ARE
EXPECTING THUNDERSTORMS TO DEVELOP OVER COLORADO AND THEN EXPAND
INTO A LARGER CLUSTER OF STORMS OVER THE PLAINS. THE EXACT
POSITIONING OF THIS STORM CLUSTER IS UNCERTAIN. SO FOR NOW, RAIN
CHANCES WERE KEPT AT 40-50% FOR LATE WEDNESDAY NIGHT INTO THURSDAY
NIGHT.
AFTER THE AFOREMENTIONED SYSTEM PASSES BY FRIDAY MORNING, A BREAK IN
PRECIPITATION IS EXPECTED FRIDAY AND SATURDAY, WITH CONTINUED
COOL WEATHER (HIGHS MAINLY IN THE 80S AND LOWS IN THE 60S). BY
THE WEEKEND, THE MID TO UPPER LEVEL FLOW WILL BECOME MORE
WEST-NORTHWESTERLY AGAIN, RESULTING IN RENEWED WEAK SURFACE LEE TROUGHING
AND WARM/MOIST ADVECTION INTO WESTERN KANSAS. THEREFORE, THERE
ARE CHANCES OF THUNDERSTORMS AGAIN BY SATURDAY NIGHT INTO MONDAY,
WITH CONTINUED COOL WEATHER (HIGHS MAINLY 80S).
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1223 AM CDT WED JUL 24 2013
VFR CONDITIONS WILL BE THE RULE TODAY, ALONG WITH NORTHEAST WINDS
OF 11G22KT. THERE IS A CHANCE FOR A LITTLE 5SM BKN025 CONDITIONS
TOWARD SUNRISE, BUT THOSE CONDITIONS SHOULD NOT LAST PAST 13Z OR
SO. WINDS LATER TODAY WILL BE NORTHEAST AT 15G25KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 86 68 83 / 40 50 50 10
GCK 68 86 66 83 / 50 50 40 10
EHA 68 87 65 85 / 50 50 40 10
LBL 69 89 67 84 / 40 50 50 10
HYS 68 84 68 82 / 40 50 50 30
P28 71 89 70 84 / 40 50 50 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...FINCH
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS GRAY ME
442 PM EDT WED JUL 24 2013
.SYNOPSIS...
A COLD FRONT WILL STALL OFFSHORE TONIGHT. HIGH PRESSURE WILL
BUILD IN FROM THE WEST THROUGH THURSDAY. HIGH PRESSURE WILL HOLD
NEAR THE REGION FRIDAY MORNING. LOW PRESSURE WILL TRACK NORTH
ALONG THE THE FRONT FRIDAY AFTERNOON THROUGH EARLY SATURDAY.
ANOTHER SYSTEM WILL APPROACH FROM THE WEST SATURDAY NIGHT AND
SUNDAY. UNSETTLED WEATHER CONTINUES INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS EXPECTED STRONG HEATING OVER THE MIDCOAST AND DELAYED FRONTAL
PUSH THERE HAS ALLOWED ENOUGH INSTABILITY TO DEVELOP FOR STRONGER
TSTMS THIS AFTERNOON. WITH FNT CROSSING THE COAST ATTM
ELSEWHERE...THE ONLY REMAINING TSTM THREAT IS FOR THE
WALDO...LINCOLN...AND KNOX COUNTY AREAS. STORM HEIGHT IS NOT
OVERLY IMPRESSIVE...BUT PCPN LOADING IN THE COLUMN AND MARGINAL
LLVL LAPSE RATES A STRONG WIND GUST OR TWO IS PSBL.
THEN MUCH COOLER DEW POINTS FILTER INTO THE REGION FROM THE NW.
THIS COUPLED WITH CLEARING AND WEAKENING WINDS WILL SUPPORT A
COMFORTABLE NIGHT WITH LOW FALLING INTO THE 40S AND LOWER 50S.
PATCHY VALLEY FOG IS PSBL GIVEN THE RECENT RNFL AND COOL TEMPS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
UPDATE...
JUST A FEW MINOR TWEAKS TO THE GRIDS TO BLEND WITH 20Z
OBSERVATIONS. CLEARING CONTINUES DOWNWIND OF THE ME/NH MOUNTAINS
LATE THIS AFTERNOON. WNW FLOW IS ALSO PUSHING ANY MARINE FOG EAST
OF OUR WATERS THIS HOUR.
CONVECTION HAS SHIFTED EAST...AND NOW ALL THE PCPN IS OVER EASTERN
MAINE. LATEST HRRR RUN KEEPS ANY NEWLY DEVELOPING SHOWER ACTIVITY
JUST EAST OF OUR COASTAL WATERS THIS EVENING.
PREV DISC...
HIGH PRES BUILDING IN FROM THE W WILL BRING PLEASANT CONDS
ON THU. EXPECT MOSTLY SUNNY SKIES...ESPECIALLY AWAY FROM THE
COAST. THE STALLED FRONTAL BOUNDARY WILL PROVIDE LINGERING CLOUDS
NEAR AND JUST OFFSHORE. WIDESPREAD HIGHS IN THE 70S ARE
EXPECTED...WITH LOW HUMIDITY.
THU NIGHT WEAK WAVE OF LOW PRES WILL BEGIN TO RIDE ALONG THE FNT.
ESPECIALLY LATE IN THE PERIOD SHRA WILL BE PSBL ACROSS SE NH AND
SW ME. THE INLAND EXTENT OF SHRA REMAINS IN QUESTION AS NWP
CONTINUES TO ADVERTISE BOTH INLAND LOW PRES TRACKS AND THOSE WELL
OUT TO SEA.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
BIG QUESTION MARK FOR FRIDAY ON WHETHER A DEVELOPING COASTAL LOW
MOVING NORTH SPREADS RAIN WELL INLAND OR KEEPS MOST OF THE RAIN
OFF THE COAST. NAM/GFS DIFFER GREATLY IN POSITION OF THE COASTAL
LOW BY FRIDAY EVENING WITH THE NAM MUCH FURTHER WEST AND ALSO
IMPLYING HEAVY RAINS FOR MUCH OF THE FA WHILE THE GFS KEEPS THE
HVY RAIN OFFSHORE WITH ONLY SOME LIGHT RAINS SKIRTING SRN/ERN
AREAS OF CWA. FOR NOW WILL HAVE TO LEAN MORE TOWARD THE GFS WITH
THE SYSTEM FURTHER E, THIS ALSO GOES ALONG THE EURO THINKING. THE
NAM SEEMS TO BE THE OUTLIER FOR NOW. THE SYSTEM EXITS BY SATURDAY
WITH CLEARING BY AFTERNOON. A MEAN L/WV TROF CENTERED NEAR THE
GREAT LAKES ALLOWS YET ANOTHER S/WV TO ROTATE NEWD INTO NEW ENGL
BY SUNDAY WITH MORE RAIN PSBL THAT WILL KEEP UNSETTLES WX INTO MON
AS WELL. BY TUES THE TROF OVER THE GT LAKES KICKS OUT NEWD
ALLOWING A DRIER WLY FLOW TO RETURN FOR THE MIDWEEK TIME FRAME.
OVERALL TEMPS TO BE NEAR OR SLIGHTLY BELOW SEASONAL LEVELS. USED A
BLEND OF THE MAV/MET GUID FOR 4TH/5TH PDS AND THEN A BLEND OF THE
ADJUSTED MEX GUID FOR THE OUTLOOK PD.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM...LOCAL MVFR/IFR CONDS ARE PSBL INVOF KRKD EARLY THIS
EVENING BEFORE VFR CONDS PREVAIL THRU THE OVERNIGHT. PATCHY VALLEY
FOG IS PSBL AFTER THE RECENT RNFL AND COOLER WX EXPECTED TONIGHT.
LOCAL IFR IN FOG IS PSBL IN THE FAVORED LOCATIONS.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
CONDS LWRG TO MVFR/IFR LATE FRI INTO EARLY SAT IN DEVELOPING AREAS
OF RAIN ESPECIALLY OVER ERN/SRN AREAS. CONDS WILL IMPROVE TO VFR
SAT BUT LOWER AGAIN TO MVFR/IFR CONDS SAT NIGHT AND INTO SUNDAY.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS ARE EXPECTED TO REMAIN BLO SCA
THRESHOLDS.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...SCA CONDS DUE TO SEAS
MAY OCCUR FRI INTO SAT DUE TO SEAS AS A COASTAL LOW PASSES OFF TO
THE EAST WITH WINDS TO MAINLY REMAIN BLO SCA CONDS. WINDS/SEAS
SHOULD REMAIN BLO SCA CONDS FOR SUNDAY INTO NEXT WEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
333 PM EDT WED JUL 24 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE REGION THURSDAY. A WEAK AREA
OF LOW PRESSURE WILL APPROACH FROM THE SOUTH FRIDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
A FRONT SYSTEM IS EXPECTED TO MOVE TO SOUTH AND EAST OF THE AREA
BY EARLY THIS EVENING. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
END QUICKLY BEHIND THE FRONT FOLLOWED BY CLEARING. FOR POPS HAVE
USED THE RUC13 INTO EARLY EVENING THEN TRANSITION TO A BLEND THE
NAM12..GFS40 ..SREF..CMCREG AND ECMWF. FOR WIND HAVE BLENDED THE
NAM12 AND MOSG25 AND WILL USE 150 PERCENT OF SUSTAINED WIND FOR
GUSTS. MOSG25 TEMPERATURE LOOKS TOO COLD TONIGHT...ESPECIALLY IN
NORTH BUT MAXIMUM TEMPERATURE THURSDAY LOOK REASONABLE SO WILL NOT
MAKE ANY CHANGES FROM PREVIOUS FORECAST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
THROUGH THE THURSDAY NIGHT TO SATURDAY TIME FRAME...A BROAD MID-
UPPER LEVEL TROUGH...TRYING TO DEVELOP A CLOSED LOW...WILL BE
SITUATED IN THE GENERAL VICINITY OF THE GREAT LAKES. FOR
MAINE...SOUTHWEST FLOW TO THE EAST OF THE TROUGH WILL CARRY
EMBEDDED SHORTWAVES INTO AND ACROSS THE REGION. GFS/EC/NAM ALL
INDICATE A DEVELOPING LOW PRESSURE SYSTEM WILL RIDE UP ALONG THE
COAST AND APPROACH SOUTHERN MAINE ON FRIDAY. MODEL SOLUTIONS DO
NOT HOLD TOGETHER PAST THAT POINT...WITH EACH BRINGING THAT LOW
ACROSS THE REGION AT DIFFERENT TIMES. GFS IS FASTEST...BRINGING
THE LOW INTO THE BAY OF FUNDY AROUND 06Z SATURDAY. THE EC IS THE
SLOWEST AT ABOUT 12 HOURS LATER. THE NAM IS BETWEEN THE TWO
TIMING-WISE BUT FARTHER NORTH. SINCE THIS IS APPROACHING DAY 4
AND THEY ARE ALL IN THE SAME GENERAL REGION...WILL GO WITH A
BLEND. SHOWERS MAY MOVE INTO DOWNEAST SECTIONS OF MAINE BY
THURSDAY NIGHT...OVERSPREADING MAINLY CENTRAL AND EASTERN
SECTIONS OF MAINE ON FRIDAY. THE BEST CHANCE FOR RAIN WILL BE
LIKELY BE LATE FRIDAY INTO EVENING FOR SOUTHEAST MAINE.
TEMPERATURES WILL BE ON THE MILD SIDE IN THE LOWER TO MID 70S
FRIDAY WITH ABUNDANT CLOUD COVER OVERSPREADING THE REGION AND
SHOWERS MOVING IN. HIGHS ON SATURDAY SHOULD BE WARMER BY SEVERAL
DEGREES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
SOME DIFFERENCES IN THE MODELS BRING SOME UNCERTAINTY TO THE LONG
TERM PERIOD. THERE IS A SHORTWAVE RIDING UP ALONG THE EASTERN SEA
BOARD FRIDAY INTO SATURDAY. THERE IS SOME DIVERGENCE ON EXACT
TIMING/PROPAGATION OF THE SURFACE LOW AND SHORTWAVE. RIGHT NOW
WILL STAY WITH SOME CONSISTENCY WITH PREVIOUS FORECAST. ALSO ON
FRIDAY A UPPER LEVEL LOW WILL DEVELOP ACROSS THE GREAT LAKES. A
SURFACE LOW AND BOUNDARY WILL ALSO DEVELOP AND MOVE EAST INTO THE
REGION FOR LATER SUNDAY. THIS ACTIVITY WILL CONTINUE THOUGH MONDAY
AS FRONT AND LOW CONTINUE TO TRACK EAST. AS UPPER LEVEL LOW AND
SURFACE LOW MOVE EAST OF MAINE EXPECT THE REGION TO SEE A BREAK
GOING INTO LATER TUESDAY AND WEDNESDAY.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
NEAR TERM: EXPECT VFR CONDITIONS TONIGHT AND THURSDAY. ONLY
EXCEPTION IS BRIEF MVFR/IFR KFVE THURSDAY MORNING IN PATCHY FOG.
SHORT TERM: VFR EXPECTED INTO FRI AT THE NORTHERN TERMINALS WITH
CONDITIONS TO POSSIBLY LOWER TO MVFR/IFR IN RAIN/FOG AT THE
SOUTHERN TERMINALS. MOSTLY MVFR/IFR FRI NIGHT INTO
SAT...ESPECIALLY AT THE SOUTHERN TERMINALS IN AREAS OF RAIN AND
FOG. THERE MAY BE SOME IMPROVEMENT SUNDAY TO MVFR TO VFR. MOSTLY
VFR FOR SUNDAY WITH PERIODS OF MVFR/IFR POSSIBLE FOR SUNDAY NIGHT
INTO MONDAY.
&&
.MARINE...
NEAR TERM: FOR WIND WILL BLEND THE NAM12 AND GFS40. FOR SEAS:
SOUTHERLY FETCH OFF THE EAST COAST STILL IN PLACE FROM THE GULF OF
MAINE SOUTHWARD. WNA IS A LITTLE HIGH WITH WAVES FROM THIS FETCH
WITH ACTUAL HEIGHTS CLOSER TO 4 FEET RATHER THAN 5 FEET. WILL USE
THE SWAN/NAM TO INITIALIZE GRIDS. WILL KEEP SEAS AROUND 4 FEET/8
SECONDS.
SHORT TERM: SEAS WILL LIKELY REMAIN BELOW SCA LEVELS THROUGH THE
WEEKEND. THERE WILL BE A SLY SWELL THAT DEVELOPS OVER THE WEEKEND
THAT COULD PUSH SEAS CLOSE TO SCA LEVELS AND WILL NEED TO BE
WATCHED. THE WNAWAVE GUIDANCE CONTINUES TO BRING THE SEAS TO 6 FT
SAT. THIS MAY BE A LITTLE TOO HIGH. VSBY WILL LIKELY BE LOWERED
IN AREAS OF FOG FRI AND FRI NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MIGNONE
SHORT TERM...RUNYAN
LONG TERM...JORDAN
AVIATION...MIGNONE/RUNYAN
MARINE...MIGNONE/RUNYAN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
727 AM EDT WED JUL 24 2013
.SYNOPSIS...
QUIET AND COMFORTABLE WEATHER CAN BE EXPECTED FOR THE REMAINDER
OF THE WORK WEEK AS HIGH PRESSURE SETTLES OVER THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
POST DAWN UPDATE FEATURED ADJUSTMENTS TO HOURLY TRENDS OF CLOUDS
AND TEMPS ONLY.
PREVIOUS...
TOUGHEST PART OF FORECAST TODAY...TRYING TO DETERMINE HOW FAST
STRATO-CU DECK WILL DISSIPATE. THERE ARE LARGE HOLES THAT HAVE
DEVELOPED IN THE LOW CLOUD DECK AND NONE OF THE MODELS ARE DOING A
VERY GOOD JOB OF PICKING UP ON THIS. LATEST NAM AND HRRR ARE
SIMILAR IN HOLDING ON TO THE CLOUD DECK AT LEAST THROUGH THE
MORNING...DECAYING FROM THE NORTH AS THE DRIER AIR MOVES IN. HAVE
SOME RESERVATIONS ON THIS...AS STATED PREVIOUSLY...MODELS ARE NOT
DEPICTING CURRENT CONDITIONS WELL. WILL GO WITH A GRADUAL DECREASE
IN CLOUD COVER FROM NORTH TO SOUTH THIS MORNING.
DRIER AND COOLER AIR WILL ACCOMPANY A LARGE SURFACE HIGH...WHICH
WILL MOVE THROUGH THE WESTERN GREAT LAKES TODAY. THE FLOW ALOFT
WILL BECOME CYCLONIC AS A SHORTWAVE TROUGH MOVES TOWARD THE AREA
LATE THIS AFTERNOON.
WILL LEAN CLOSE TO CURRENT LAMP NUMBERS FOR HIGHS WHICH SHOULD BE
WELL BELOW NORMAL. OVERALL CONDITIONS WILL BE VERY COMFORTABLE AS
SFC TDS FALL IN THE LOWER TO MID 50S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
UPPER LEVEL TROUGH WILL HANG AROUND THROUGH MUCH OF THURSDAY NIGHT
AS A DRY AIR MASS TAKES HOLD. EXPECT PLENTY OF SUNSHINE THURSDAY
WITH BELOW NORMAL TEMPS.
RIDGE WILL BUILD IN FRIDAY KEEPING THE AREA DRY AND WARMING TEMPS
TO NEAR NORMAL LEVELS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A LONG WAVE TROUGH IS FORECAST TO CONTROL ERN CONUS WEATHER
THROUGH THE WEEKEND. AS A RESULT...AOB SEASONAL AVERAGE TEMPS CAN
BE EXPECTED AS WELL AS SHRTWV DEPENDENT PCPN CHCS.
BEYOND THE WEEKEND...MDL CONSENSUS IS THAT THE TROF WL BGN TO
FILL...HENCE THE NEW WEEK WL FEATURE WARMER TEMPS AND LOWER POPS.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
STRATOCU IN THE COLD ADVCTN REGIME BEHIND LAST NGTS CDFNT WL CONT
TO FLOW OVR UPR OHIO PORTS THIS MRNG...BUT CLD DECKS ARE EXPECTED
TO RMN JUST ABOVE THE MVFR AT MOST PORTS...AND THOSE RESTRICTIONS
WL BE BRIEF.
SFC TROF TO THE N OF I 80 HAS BACKED WIND TO THE NW AT FKL AND
DUJ...BUT THAT FEATURE WL NOT LINGER AND A MODEST N WIND WL FLOW
ACRS AREA TERMINALS TDA.
OUTOUTLOOK.../THURSDAY THROUGH SUNDAY/...
THE NXT CHC FOR GENL RESTRNS IS EXPECTED WITH THE APPRCH AND
PASSAGE OF A WEEKEND CDFNT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
411 AM EDT WED JUL 24 2013
.SYNOPSIS...
HIGH PRESSURE WILL FINALLY BRING SOME QUIET AND COMFORTABLE
WEATHER FOR THE REMAINDER OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TOUGHEST PART OF FORECAST TODAY...TRYING TO DETERMINE HOW FAST
STRATO-CU DECK WILL DISSIPATE. THERE ARE LARGE HOLES THAT HAVE
DEVELOPED IN THE LOW CLOUD DECK AND NONE OF THE MODELS ARE DOING A
VERY GOOD JOB OF PICKING UP ON THIS. LATEST NAM AND HRRR ARE
SIMILAR IN HOLDING ON TO THE CLOUD DECK AT LEAST THROUGH THE
MORNING...DECAYING FROM THE NORTH AS THE DRIER AIR MOVES IN. HAVE
SOME RESERVATIONS ON THIS...AS STATED PREVIOUSLY...MODELS ARE NOT
DEPICTING CURRENT CONDITIONS WELL. WILL GO WITH A GRADUAL DECREASE
IN CLOUD COVER FROM NORTH TO SOUTH THIS MORNING.
DRIER AND COOLER AIR WILL ACCOMPANY A LARGE SURFACE HIGH...WHICH
WILL MOVE THROUGH THE WESTERN GREAT LAKES TODAY. THE FLOW ALOFT
WILL BECOME CYCLONIC AS A SHORTWAVE TROUGH MOVES TOWARD THE AREA
LATE THIS AFTERNOON.
WILL LEAN CLOSE TO CURRENT LAMP NUMBERS FOR HIGHS WHICH SHOULD BE
WELL BELOW NORMAL. OVERALL CONDITIONS WILL BE VERY COMFORTABLE AS
SFC TDS FALL IN THE LOWER TO MID 50S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
UPPER LEVEL TROUGH WILL HANG AROUND THROUGH MUCH OF THURSDAY NIGHT
AS A DRY AIR MASS TAKES HOLD. EXPECT PLENTY OF SUNSHINE THURSDAY
WITH BELOW NORMAL TEMPS.
RIDGE WILL BUILD IN FRIDAY KEEPING THE AREA DRY AND WARMING TEMPS
TO NEAR NORMAL LEVELS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A LONG WAVE TROUGH IS FORECAST TO CONTROL ERN CONUS WEATHER
THROUGH THE WEEKEND. AS A RESULT...AOB SEASONAL AVERAGE TEMPS CAN
BE EXPECTED AS WELL AS SHRTWV DEPENDENT PCPN CHCS.
BEYOND THE WEEKEND...MDL CONSENSUS IS THAT THE TROF WL BGN TO
FILL...HENCE THE NEW WEEK WL FEATURE WARMER TEMPS AND LOWER POPS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
TSTMS HAVE MOVED OUT OF THE TERMINALS. A SHWR OR TSTM IS PSBL AS A
CDFNT MOVES THRU OVRNGT BUT COVG TOO LTL FOR TAF INCLUSION. POST
FRONTAL MVFR STRATOCU SEEN ON STLT MOVG S AND THIS SHOULD AFFECT
THE TERMINALS OVRNGT INTO WED MRNG. CIGS SHOULD LIFT TO VFR BY LT
MRNG AND GRDLY SCT OUT THRU THE DAY.
OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
VFR CONDS EXPD THRU SAT MRNG. RESTRNS ARE PSBL WITH THE APPRCH AND
PASSAGE OF A WEEKEND CDFNT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
1036 PM EDT THU JUL 25 2013
.SYNOPSIS...
ISSUED AT 409 PM EDT THU JUL 25 2013
HIGH PRESSURE IS PULLING OFF TO THE NORTHEAST THIS EVENING...
ALLOWING A STORM SYSTEM THAT IS ORGANIZING OVER THE PLAINS TO TAKE
AIM ON THE GREAT LAKES. THIS AREA OF LOW PRESSURE WILL MOVE OVER
THE AREA TONIGHT AND INTO FRIDAY...GENERATING BELOW NORMAL
TEMPERATURES AND MUCH NEEDED RAINFALL ACROSS NORTHERN MICHIGAN.
THIS STORM SYSTEM WILL MOVE SLOWLY...KEEPING UNSETTLED AUTUMN LIKE
WEATHER IN THE AIR THROUGH THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1033 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: CONVECTION-INDUCED VORT MAX CONTINUES TO SPAWN
ADDITIONAL CONVECTION ALONG ADVANCING DEEP MOISTURE PLUME. OVER
THE PAST HOUR...EASTERN EDGE OF CONVECTION HAS HAD TROUBLE MAKING
MUCH EASTWARD PROGRESS...BUT IS FINALLY BEGINNING TO MOVE AS OF
THIS WRITING. THUS...WILL CONTINUE TO UP POPS FOR THE
OVERNIGHT...WITH CATEGORICAL FOR THE TIP OF THE MITT/EASTERN
UPPER...AND TAPERING OFF AS YOU HEAD SOUTH /PARTICULARLY SOUTH OF
M-32/ WHERE DRY AIR WILL LIKELY BE ABLE TO HOLD ON FOR MOST OF THE
NIGHT. LIGHTNING HAS BEEN GRADUALLY COMING DOWN CONVECTION HEADS
EAST IN TO MORE STABLE AIRMASS...AND FULLY EXPECT THIS TREND TO
CONTINUE.
UPDATE ISSUED AT 934 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: MQT 88D IMAGERY DISPLAYS COMPACT YET IMPRESSIVE
VORT MAX ASSOCIATED WITH STRONG-SEVERE CONVECTION THAT HAS GROWN
SOMEWHAT UPSCALE IN THE PAST TWO HOURS. THIS VORT IS INTERACTING
WITH THE LEADING EDGE OF THE DEEP MOISTURE PLUME TO EXPAND SHOWERS
/AND SOME THUNDER/ INTO WESTERN CHIP/MACK AS OF THIS WRITING.
SATURATION HAS ONLY REACHED DOWN INTO THE MID-LEVELS AT THIS
POINT...BUT AS SOUTHWESTERLY LLJ STRENGTHENS THIS EVENING...EXPECT
ONGOING ECHOES TO EXPAND EAST THROUGH THE TIP OF THE MITT AND THE
REMAINDER OF EASTERN UPPER. WILL UP POPS TO CATEGORICAL IN THESE
AREAS WITH CHANCE /OR LESS/ REMAINING SOUTH OF A TVC-GLR-APN LINE.
MUCAPE PLUME CONTINUES TO MAKE LITTLE/NO EASTWARD PROGRESS...SO
CURRENT TREND OF THUNDER DIMINISHING AS ACTIVITY SPREADS EAST WILL
CONTINUE...WITH NO SEVERE THREAT FORESEEN OVERNIGHT.
UPDATE ISSUED AT 808 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: IMPRESSIVE CONVECTIVE GROWTH OVER CENTRAL UPPER
OVER THE PAST HOUR HAS LED TO AN EXPANDING BAND OF RETURNS
SPREADING EAST TOWARDS CHIP/MACK. WHILE AIRMASS DOWNSTAIRS
CONTINUES TO BE FAIRLY DRY /00Z RAOB IN PROGRESS/ THINK THAT SOME
OF THESE RETURNS WILL REACH THE GROUND OVER THE NEXT 1-2 HOURS AND
HAVE SPED UP POPS HERE ACCORDINGLY. WILL ALSO ADJUST OVERNIGHT
POPS TO SPEED UP EASTWARD PROGRESS OVER EASTERN UPPER AND SLOW IT
TO THE SOUTH OF M-32 IN LINE WITH DEVELOPING CONVECTION OVER
WESTERN UPPER...WHICH SHOULD CONTINUE TO SLIDE EAST GIVEN GOOD
DYNAMIC FORCING...IN TANDEM WITH ARRIVING DEEPER MOISTURE.
DESPITE ONGOING WARNINGS WEST OF LAKE MICHIGAN...SEVERE THREAT
WILL DIMINISH MARKEDLY AS THIS CONVECTION SPREADS EAST. BEST
CHANCE FOR THUNDER WILL COME WELL AFTER MIDNIGHT AS MUCAPE PLUME
OVER WISCONSIN GETS TUGGED NORTH TOWARDS EASTERN UPPER AS
CONVECTIVE DEBRIS PUSHES EAST.
UPDATE ISSUED AT 659 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: PRIMARY CHANGES HAVE BEEN TO NEAR TERM SKY
TRENDS AS MANY SPOTS EAST OF I-75 ENJOYING ONLY A FEW CLOUDS TO
END THE DAY. CONVECTION CONTINUES TO FIRE ALONG LEADING EDGE OF
DEEPER MOISTURE ALOFT WITH MUCAPE PLUME INTERACTING WITH
INCREASING FLOW ALOFT TO PRODUCE A FEW ROBUST CELLS. HRRR WANTS TO
BRING A SLUG OF ACTIVITY IN HERE OVERNIGHT /DECAYING AS IT HEADS
EAST/...BUT NOT READY TO BITE ON THIS YET GIVEN LACK OF
DEVELOPMENT OVER CENTRAL WISCONSIN. THUS...WILL WATCH THE NEXT 1-2
HOURS OF CONVECTIVE EVOLUTION AND MAKE POP ADJUSTMENTS AT THAT
POINT. IF SUBSTANTIAL RAINFALL CANNOT REACH INTO NORTHERN
LOWER...COULD SEE LOW TEMPS NEEDING UPWARD ADJUSTMENT WITH SOME
REMAINING GRADIENT AND TOP-DOWN SATURATION INCREASING CLOUDS
ALOFT.
DESPITE UPSTREAM WARNINGS...SEE LITTLE SEVERE THREAT THIS FAR EAST
AS INSTABILITY PLUME WILL QUICKLY WANE AS IT FOLDS INTO VERY DRY
LLEVEL AIRMASS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
BIG OLE` CHANGES A COMING...AN UNFORTUNATE FACT WELL DISPLAYED ON
AFTERNOON NOAM WATER VAPOR IMAGERY. PATTERN AMPLIFICATION KICKING
INTO FULL GEAR PER SUCH...WITH LEAD CHARGING SHORTWAVE KICKING OUT
OF SOUTHERN MANITOBA...WITH SECONDARY SLUG OF ENERGY JUST UPSTREAM.
THESE WILL EVENTUALLY MORPH INTO AN UNSEASONABLY STRONG UPPER LEVEL
LOW OVER THE NORTHERN LAKES FOR THIS UPCOMING WEEKEND...BRINGING
WITH IT WEATHER MUCH MORE REPRESENTATIVE OF SEPTEMBER THAN JULY.
ATTENDANT SURFACE REFLECTION ATTEMPTING TO TAKE SHAPE...WITH
ELONGATED LOW PRESSURE OVER NORTHERN MINNESOTA AND A DEVELOPING COLD
FRONT ARCHING BACK SOUTHWEST IN THROUGH THE CENTRAL PLAINS.
PRE-FRONTAL MOISTURE ADVECTION NOT OVERLY IMPRESSIVE JUST YET...WITH
ONLY LOWER 60 DEWPOINTS BACK ACROSS THE FAR WESTERN LAKES. AS A
RESULT...UPSTREAM SHOWER AND STORM COVERAGE HAS BEEN SOMEWHAT ON THE
LEAN SIDE...WITH BEST RAIN COVERAGE REMAINING WELL TO OUR NORTH AND
NORTHWEST. FORECAST CONCERNS REMAIN FOCUSED ON INCREASING...AND MUCH
NEEDED...RAIN AND STORM CHANCES THROUGH FRIDAY AS UPSTREAM SYSTEM
FURTHER CONGEALS.
WOULD EXPECT UPWARD TREND IN UPSTREAM RADAR ACTIVITY THIS EVENING AS
INCREASING MOISTURE ADVECTION BECOMES TUCKED UNDER NICE SLUG OF
DEEPENING MID AND UPPER LEVEL SUPPORT. UPSTREAM FORCING/MOISTURE
SPREADS SLOWLY EAST THROUGH THE OVERNIGHT...WITH ATTENDANT THETA-E
RIDGING ARCHING NORTHEAST...BISECTING NORTHERN MICHIGAN BY MORNING.
DIFLUENT MID LEVEL FLOW/UPTICK IN UPWARD QG SUPPORT AND SIMPLE DEEP
LAYER MOISTURE ADVECTION SHOULD SUPPORT UPSTREAM SHOWERS TO SPREAD
EAST...AT LEAST SPREADING ACROSS NORTHWEST SECTIONS OF THE AREA
THROUGH THE OVERNIGHT. SOUTHEAST THIRD OF THE AREA EXPECTED TO
REMAIN DRY...JUST A TOUCH TOO FAR REMOVED FROM BEST JUXTAPOSITION OF
THE ABOVE...ALONG WITH SOME LINGERING SUB H8 DRY AIR. THUNDER
CHANCES NOT OVERWHELMING...BUT NOT ZERO EITHER...WITH CORRIDOR OF
SEVERAL HUNDRED J/KG OF MU CAPE TIED TO ABOVE DYNAMICS. ANY SEVERE
THREAT LIKELY TO REMAIN UPSTREAM WHERE STORMS WILL INITIALLY BE
SURFACE BASED.
DYNAMICS CONTINUE TO RATCHET UP HEADING THROUGH FRIDAY WITH UPSTREAM
SHORTWAVE DEEPENING AND TAKING ON A NEUTRAL/NEGATIVE TILT OVER
WISCONSIN. BACKSIDE CAA STRENGTHENS LOW LEVEL TEMPERATURE
GRADIENT...WITH A RATHER POTENT COLD FRONT TAKING SHAPE JUST
DOWNSTREAM OF PARENT MID LEVEL TROUGH AXIS. LOW PRESSURE DEVELOPING
AND RIDING NORTHEAST ALONG THIS FRONT INTO EASTERN LAKE SUPERIOR
WILL INITIALLY SLOW THE FRONTS EASTWARD PROGRESS FRIDAY
AFTERNOON...LIKELY ONLY REACHING CENTRAL LAKE MICHIGAN BY EVENING.
SHOWERS SHOULD ONLY INCREASE IN COVERAGE...WITH THE
STEADIEST/HEAVIEST RAINS TARGETING EASTERN UPPER/FAR NORTHWEST LOWER
MICHIGAN WHERE STRONGEST DEEP LAYER CONVERGENCE AND MOISTURE
ADVECTION ARE ALIGNED. SEVERE THREAT HIGHLY PREDICATED BY CHANCES
FOR DIURNAL DESTABILIZATION. NOT EXPECTING MUCH OPPORTUNITY FOR
SUCH...WITH CROSS SECTION MOISTURE PROGS SUPPORTING A MOSTLY CLOUDY
DAY...EVEN ACROSS THE RELATIVELY DRY SOUTHERN SIDE OF THE SUNRISE
SIDE. CANNOT COMPLETELY RULE OUT AN ISOLATED SEVERE EVENT...
HOWEVER...WITH SUCH DYNAMICS AND CORE OF NEAR 50 KNOTS DEEP LAYER
SHEAR ACROSS EASTERN UPPER. TEMPERATURES REMAIN RATHER TRICKY GIVEN
RAIN AND ABUNDANT CLOUD COVER. INHERITED HIGHS IN THE UPPER
60S/LOWER-MIDDLE 70S AS GOOD A STARTING POINT AS ANY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
OVERVIEW: HEMISPHERIC PATTERN HAS EVOLVED INTO A 5-WAVE LONG WAVE
CONFIGURATION WITH ONE LONG WAVE TROUGH AXIS STRETCHING DOWN THROUGH
EASTERN NOAM. RIDGING ACROSS THE WESTERN CONUS WHERE THE WARM AIR
RESIDES...LINKING BACK TO TROUGHINESS IN THE GULF OF ALASKA AND THE
EASTERN PACIFIC. 5-WAVE PATTERN FORECAST TO REMAIN ESSENTIALLY
UNCHANGED THROUGH THE UPCOMING SEVEN DAYS BUT WITH SLOW WESTWARD
RETROGRESSION OF THE EASTERN NOAM TROUGH INTO THE PLAINS THROUGH THE
WEEKEND AND INTO NEXT WEEK. SHORT WAVE TROUGH AND POCKET OF SOME
FAIRLY CHILLY AIR STILL SLATED TO SETTLE INTO THE GREAT LAKES FOR
THIS WEEKEND...WHICH WILL BE INTERESTING. WARMER AIR DOES MAKE A
RETURN NEXT WEEK AS THE PATTERN FLATTENS ACROSS THE CONUS...BUT JUST
GETS BACK TO NEAR NORMAL.
FRIDAY NIGHT...TRANSITION PERIOD AS SHORT WAVE TROUGH DEEPENS AND
DIGS INTO THE GREAT LAKES PUSHING A SFC LOW AND COLD FRONT THROUGH
THE REGION. SYSTEM HAS SOME STRONG STORM POTENTIAL WITH A NICE PULSE
OF QG-UPWARD FORCING AND DECENT LOW LEVEL CONVERGENCE ALONG THE
FRONT AND SFC LOW WHICH IS SLATED TO TRACK THROUGH NRN LAKE
MICHIGAN/TIP OF THE MITT/EASTERN UPPER FRIDAY AFTERNOON/EVENING.
COUPLED WITH 30 TO 50 KNOT MID LEVEL WINDS AND RESULTING 0-6KM BULK
SHEAR VALUES IN EXCESS OF 30 KNOTS...ANY STORMS THAT FORM WILL HAVE
POTENTIAL TO GET ORGANIZED. BUT...INSTABILITY IS ONCE AGAIN AN
ISSUE. FORECAST SOUNDINGS (EVEN UNMODIFIED) ARE NOT THAT IMPRESSIVE
IN THE INSTABILITY DEPARTMENT AND EVEN RAW MODEL MLCAPE VALUES ARE
LARGELY UNDER 500 J/KG. NOT GREAT. NO SURPRISE THAT BETTER
INSTABILITY WILL RESIDE ACROSS EASTERN/SOUTHERN WISCONSIN DOWN INTO
LOWER MICHIGAN AND THE OHIO VALLEY AND SUSPECT BETTER ORGANIZED
CONVECTION WILL ONCE AGAIN OCCUR IN THOSE AREAS. THAT SAID...IF WE
CAN GET CONVECTION TO FIRE...ANY STORMS COULD PRODUCE GUSTY WINDS
AND SOME HAIL.
SATURDAY AND SUNDAY...WELCOME FALL. FOLLOWING FROPA...POCKET OF
CHILLY AIR (+3C TO +6C 850 MB AIR) DESCENDS INTO THE GREAT LAKES
SATURDAY SETTLING OVERHEAD FOR SUNDAY. SATURDAY STILL LOOKING LIKE A
TRANSITION DAY AS COLD ADVECTION PROCEEDS THROUGH THE DAY AND PARTS
OF THE CWA (SE COUNTIES) MAY SQUEAK TOUCH THE 70S. COULD ACTUALLY
START THE DAY WITH SOME SUNSHINE AS MID LEVEL DRY SLOT WORKS THROUGH
THE AREA. BUT WITH LAKE SFC TEMPS RUNNING +17C TO +20C...CLOUDY
SKIES ARE CERTAIN TO DEVELOP ALONG WITH AT LEAST A CHANCE FOR HYBRID
LAKE/HEATING INDUCED RAIN SHOWERS SATURDAY AFTERNOON. THAT
SAID...DEPTH OF THE COLD AIR IS NOT TERRIBLY IMPRESSIVE WITH A BIT
OF A WARMER CAPPING LAYER ALOFT WHICH MAY PUT THE BRAKES ON
LAKE/LAND BASED CONVECTION SATURDAY AFTERNOON. HENCE WILL KEEP POPS
ON THE LOW SIDE FOR SATURDAY. SUNDAY LOOKS BETTER FOR SHOWERS AS
WARMER LAYER ALOFT IS ERODED ALONG WITH FLAT OUT CLOUDY SKIES AND A
TRUE FALL-LIKE FEEL. HAVE HIGHS ON SUNDAY RANGING FROM THE MID 50S
TO MID 60S.
WATERSPOUT POTENTIAL...WOULD BE MORE IMPRESSIVE IF THE CONVECTIVE
DEPTH WAS DEEPER (PER SZILAGYI WATERSPOUT NOMOGRAM). WILL STILL
HIGHLIGHT THE CHANCE FOR WATERSPOUTS IN THE HAZARDOUS WEATHER
OUTLOOK AS WELL AS IN THE FORECAST FOR BOTH SATURDAY AND SUNDAY...
BUT THE POTENTIAL DOES NOT LOOK AS GOOD AS IT LOOKED A DAY OR TWO
AGO BY VIRTUE OF THE SHALLOWER COLD AIR.
MONDAY THROUGH THURSDAY...IMPROVEMENT FOR THE START THE NEXT WORK
WEEK WITH HIGH PRESSURE AND LOW AMPLITUDE RIDGING BUILDING ACROSS
THE REGION FOR MONDAY AND TUESDAY...ALONG WITH TEMPS REBOUNDING INTO
THE 70S (STILL BELOW NORMAL). NRN STREAM SYSTEM SLATED TO SLOWLY DIP
INTO THE REGION WEDNESDAY AND THURSDAY...SLOWER THAN IN PREVIOUS
SOLUTIONS. BUT THIS WILL BRING LOW END CHANCES FOR SHOWERS BACK INTO
THE FORECAST TO ROUND OUT THE EXTENDED FORECAST...WITH TEMPS RUNNING
JUST A LITTLE BELOW NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 731 PM EDT THU JUL 25 2013
SUMMARY: LOW PRESSURE NOW OVER NORTHERN MINNESOTA WILL STRENGTHEN AS
IT PUSHES INTO THE UPPER GREAT LAKES REGION...WITH A STRONG COLD
FRONT APPROACHING THE REGION FROM THE WEST BY LATE DAY FRIDAY. THIS
FRONT WILL BRING SHOWERS AND THUNDERSTORMS TO ALL TERMINALS BY THE
END OF THE COMING TAF PERIOD...ALONG WITH DETERIORATING FLYING
CONDITIONS.
RESTRICTIONS: VFR ALL SITES ATTM WITH VFR EXPECTED TO CONTINUE
THROUGH THE OVERNIGHT HOURS. SHOWERS WILL ATTEMPT TO MAKE THE TREK
ACROSS LAKE MICHIGAN THIS EVENING...AND WILL LIKELY REACH PLN AFTER
MIDNIGHT...WITH SOME ACTIVITY POTENTIALLY REACHING TVC/MBL BEFORE
DAYBREAK. AT THIS TIME...EXPECT ANY OVERNIGHT ACTIVITY TO REMAIN
GENERALLY UNRESTRICTED. ON FRIDAY....SHOWERS /AND EMBEDDED
THUNDERSTORMS/ WILL INCREASE IN COVERAGE AND MOVE FROM WEST TO
EAST...WITH MVFR CIGS/VSBYS DEVELOPING BY EARLY AFTERNOON
PLN/TVC/MBL AND DURING THE AFTERNOON AT APN.
THUNDER: CHANCES NOT LOOKING GREAT FOR MUCH THUNDER...BEST SHOT WILL
BE AT APN /FRONT ARRIVES HERE LAST/ FRIDAY AFTERNOON. CHANCES FOR
OCCURRENCE TOO LOW AT THIS STAGE TO INCLUDE EXPLICIT MENTION IN THE
TAFS.
LLWS: LOW LEVEL JET WILL STRENGTHEN OVERNIGHT AS LOW PRESSURE
STRENGTHENS TO OUR NORTH AND WEST. THIS SHOULD FAVOR THE
DEVELOPMENT OF LLWS OVERNIGHT WITH 1.5KFT WINDS REACHING 30KTS FROM
THE SOUTHWEST...BUT NOT UNTIL MIDNIGHT AND AFTER. ANY SHEAR LAYER
WILL MIX OUT FRIDAY MORNING.
WINDS: LOCAL LAKE BREEZES AROUND 10KTS /WITH GUSTS TO 15KTS/ WILL
SUBSIDE THIS EVENING WITH SOUTHERLY WINDS 5KTS OR LESS /LIKELY
BECOMING LIGHT-VARIABLE FOR A TIME DURING THE FIRST HALF OF THE
NIGHT/. SOUTH-SOUTHWEST WINDS WILL STRENGTHEN TO 10G18KTS FOR THE
DAY ON FRIDAY...WITH A SHIFT TO WEST OCCURRING SHORTLY AFTER THE END
OF THIS TAF PERIOD.
&&
.MARINE...
ISSUED AT 409 PM EDT THU JUL 25 2013
SOUTH WINDS WILL CONTINUE ACROSS THE BIG WATERS TONIGHT
INTO FRIDAY...BUT LOOK TO REMAIN BELOW SCA LEVELS. LONG AND
PERSISTENT SOUTHERLY FETCH WILL RESULT IN SOME CHOPPY
WATERS...ESPECIALLY ACROSS THE NORTH HALF OF LAKE MICHIGAN. WILL
NEED TO MONITOR...BUT THESE ALSO LOOK TO REMAIN JUST BELOW SCA
LEVELS. STRONG COLD FRONT PUSHES ACROSS THE AREA FRIDAY NIGHT. WEST
WINDS TO FOLLOW INTO THIS WEEKEND...AT TIMES GUSTY. WILL NEED TO
MONITOR WATERSPOUT POTENTIAL THIS WEEKEND AS UNSEASONABLY STRONG
UPPER LEVEL LOW PRESSURE WOBBLES OVERHEAD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...BA
AVIATION...ARNOTT
MARINE...MB
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
941 PM EDT THU JUL 25 2013
.SYNOPSIS...
ISSUED AT 409 PM EDT THU JUL 25 2013
HIGH PRESSURE IS PULLING OFF TO THE NORTHEAST THIS EVENING...
ALLOWING A STORM SYSTEM THAT IS ORGANIZING OVER THE PLAINS TO TAKE
AIM ON THE GREAT LAKES. THIS AREA OF LOW PRESSURE WILL MOVE OVER
THE AREA TONIGHT AND INTO FRIDAY...GENERATING BELOW NORMAL
TEMPERATURES AND MUCH NEEDED RAINFALL ACROSS NORTHERN MICHIGAN.
THIS STORM SYSTEM WILL MOVE SLOWLY...KEEPING UNSETTLED AUTUMN LIKE
WEATHER IN THE AIR THROUGH THE WEEKEND.
&&
.UPDATE...
ISSUED AT 934 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: MQT 88D IMAGERY DISPLAYS COMPACT YET IMPRESSIVE
VORT MAX ASSOCIATED WITH STRONG-SEVERE CONVECTION THAT HAS GROWN
SOMEWHAT UPSCALE IN THE PAST TWO HOURS. THIS VORT IS INTERACTING
WITH THE LEADING EDGE OF THE DEEP MOISTURE PLUME TO EXPAND SHOWERS
/AND SOME THUNDER/ INTO WESTERN CHIP/MACK AS OF THIS WRITING.
SATURATION HAS ONLY REACHED DOWN INTO THE MID-LEVELS AT THIS
POINT...BUT AS SOUTHWESTERLY LLJ STRENGTHENS THIS EVENING...EXPECT
ONGOING ECHOES TO EXPAND EAST THROUGH THE TIP OF THE MITT AND THE
REMAINDER OF EASTERN UPPER. WILL UP POPS TO CATEGORICAL IN THESE
AREAS WITH CHANCE /OR LESS/ REMAINING SOUTH OF A TVC-GLR-APN LINE.
MUCAPE PLUME CONTINUES TO MAKE LITTLE/NO EASTWARD PROGRESS...SO
CURRENT TREND OF THUNDER DIMINISHING AS ACTIVITY SPREADS EAST WILL
CONTINUE...WITH NO SEVERE THREAT FORESEEN OVERNIGHT.
UPDATE ISSUED AT 808 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: IMPRESSIVE CONVECTIVE GROWTH OVER CENTRAL UPPER
OVER THE PAST HOUR HAS LED TO AN EXPANDING BAND OF RETURNS
SPREADING EAST TOWARDS CHIP/MACK. WHILE AIRMASS DOWNSTAIRS
CONTINUES TO BE FAIRLY DRY /00Z RAOB IN PROGRESS/ THINK THAT SOME
OF THESE RETURNS WILL REACH THE GROUND OVER THE NEXT 1-2 HOURS AND
HAVE SPED UP POPS HERE ACCORDINGLY. WILL ALSO ADJUST OVERNIGHT
POPS TO SPEED UP EASTWARD PROGRESS OVER EASTERN UPPER AND SLOW IT
TO THE SOUTH OF M-32 IN LINE WITH DEVELOPING CONVECTION OVER
WESTERN UPPER...WHICH SHOULD CONTINUE TO SLIDE EAST GIVEN GOOD
DYNAMIC FORCING...IN TANDEM WITH ARRIVING DEEPER MOISTURE.
DESPITE ONGOING WARNINGS WEST OF LAKE MICHIGAN...SEVERE THREAT
WILL DIMINISH MARKEDLY AS THIS CONVECTION SPREADS EAST. BEST
CHANCE FOR THUNDER WILL COME WELL AFTER MIDNIGHT AS MUCAPE PLUME
OVER WISCONSIN GETS TUGGED NORTH TOWARDS EASTERN UPPER AS
CONVECTIVE DEBRIS PUSHES EAST.
UPDATE ISSUED AT 659 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: PRIMARY CHANGES HAVE BEEN TO NEAR TERM SKY
TRENDS AS MANY SPOTS EAST OF I-75 ENJOYING ONLY A FEW CLOUDS TO
END THE DAY. CONVECTION CONTINUES TO FIRE ALONG LEADING EDGE OF
DEEPER MOISTURE ALOFT WITH MUCAPE PLUME INTERACTING WITH
INCREASING FLOW ALOFT TO PRODUCE A FEW ROBUST CELLS. HRRR WANTS TO
BRING A SLUG OF ACTIVITY IN HERE OVERNIGHT /DECAYING AS IT HEADS
EAST/...BUT NOT READY TO BITE ON THIS YET GIVEN LACK OF
DEVELOPMENT OVER CENTRAL WISCONSIN. THUS...WILL WATCH THE NEXT 1-2
HOURS OF CONVECTIVE EVOLUTION AND MAKE POP ADJUSTMENTS AT THAT
POINT. IF SUBSTANTIAL RAINFALL CANNOT REACH INTO NORTHERN
LOWER...COULD SEE LOW TEMPS NEEDING UPWARD ADJUSTMENT WITH SOME
REMAINING GRADIENT AND TOP-DOWN SATURATION INCREASING CLOUDS
ALOFT.
DESPITE UPSTREAM WARNINGS...SEE LITTLE SEVERE THREAT THIS FAR EAST
AS INSTABILITY PLUME WILL QUICKLY WANE AS IT FOLDS INTO VERY DRY
LLEVEL AIRMASS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
BIG OLE` CHANGES A COMING...AN UNFORTUNATE FACT WELL DISPLAYED ON
AFTERNOON NOAM WATER VAPOR IMAGERY. PATTERN AMPLIFICATION KICKING
INTO FULL GEAR PER SUCH...WITH LEAD CHARGING SHORTWAVE KICKING OUT
OF SOUTHERN MANITOBA...WITH SECONDARY SLUG OF ENERGY JUST UPSTREAM.
THESE WILL EVENTUALLY MORPH INTO AN UNSEASONABLY STRONG UPPER LEVEL
LOW OVER THE NORTHERN LAKES FOR THIS UPCOMING WEEKEND...BRINGING
WITH IT WEATHER MUCH MORE REPRESENTATIVE OF SEPTEMBER THAN JULY.
ATTENDANT SURFACE REFLECTION ATTEMPTING TO TAKE SHAPE...WITH
ELONGATED LOW PRESSURE OVER NORTHERN MINNESOTA AND A DEVELOPING COLD
FRONT ARCHING BACK SOUTHWEST IN THROUGH THE CENTRAL PLAINS.
PRE-FRONTAL MOISTURE ADVECTION NOT OVERLY IMPRESSIVE JUST YET...WITH
ONLY LOWER 60 DEWPOINTS BACK ACROSS THE FAR WESTERN LAKES. AS A
RESULT...UPSTREAM SHOWER AND STORM COVERAGE HAS BEEN SOMEWHAT ON THE
LEAN SIDE...WITH BEST RAIN COVERAGE REMAINING WELL TO OUR NORTH AND
NORTHWEST. FORECAST CONCERNS REMAIN FOCUSED ON INCREASING...AND MUCH
NEEDED...RAIN AND STORM CHANCES THROUGH FRIDAY AS UPSTREAM SYSTEM
FURTHER CONGEALS.
WOULD EXPECT UPWARD TREND IN UPSTREAM RADAR ACTIVITY THIS EVENING AS
INCREASING MOISTURE ADVECTION BECOMES TUCKED UNDER NICE SLUG OF
DEEPENING MID AND UPPER LEVEL SUPPORT. UPSTREAM FORCING/MOISTURE
SPREADS SLOWLY EAST THROUGH THE OVERNIGHT...WITH ATTENDANT THETA-E
RIDGING ARCHING NORTHEAST...BISECTING NORTHERN MICHIGAN BY MORNING.
DIFLUENT MID LEVEL FLOW/UPTICK IN UPWARD QG SUPPORT AND SIMPLE DEEP
LAYER MOISTURE ADVECTION SHOULD SUPPORT UPSTREAM SHOWERS TO SPREAD
EAST...AT LEAST SPREADING ACROSS NORTHWEST SECTIONS OF THE AREA
THROUGH THE OVERNIGHT. SOUTHEAST THIRD OF THE AREA EXPECTED TO
REMAIN DRY...JUST A TOUCH TOO FAR REMOVED FROM BEST JUXTAPOSITION OF
THE ABOVE...ALONG WITH SOME LINGERING SUB H8 DRY AIR. THUNDER
CHANCES NOT OVERWHELMING...BUT NOT ZERO EITHER...WITH CORRIDOR OF
SEVERAL HUNDRED J/KG OF MU CAPE TIED TO ABOVE DYNAMICS. ANY SEVERE
THREAT LIKELY TO REMAIN UPSTREAM WHERE STORMS WILL INITIALLY BE
SURFACE BASED.
DYNAMICS CONTINUE TO RATCHET UP HEADING THROUGH FRIDAY WITH UPSTREAM
SHORTWAVE DEEPENING AND TAKING ON A NEUTRAL/NEGATIVE TILT OVER
WISCONSIN. BACKSIDE CAA STRENGTHENS LOW LEVEL TEMPERATURE
GRADIENT...WITH A RATHER POTENT COLD FRONT TAKING SHAPE JUST
DOWNSTREAM OF PARENT MID LEVEL TROUGH AXIS. LOW PRESSURE DEVELOPING
AND RIDING NORTHEAST ALONG THIS FRONT INTO EASTERN LAKE SUPERIOR
WILL INITIALLY SLOW THE FRONTS EASTWARD PROGRESS FRIDAY
AFTERNOON...LIKELY ONLY REACHING CENTRAL LAKE MICHIGAN BY EVENING.
SHOWERS SHOULD ONLY INCREASE IN COVERAGE...WITH THE
STEADIEST/HEAVIEST RAINS TARGETING EASTERN UPPER/FAR NORTHWEST LOWER
MICHIGAN WHERE STRONGEST DEEP LAYER CONVERGENCE AND MOISTURE
ADVECTION ARE ALIGNED. SEVERE THREAT HIGHLY PREDICATED BY CHANCES
FOR DIURNAL DESTABILIZATION. NOT EXPECTING MUCH OPPORTUNITY FOR
SUCH...WITH CROSS SECTION MOISTURE PROGS SUPPORTING A MOSTLY CLOUDY
DAY...EVEN ACROSS THE RELATIVELY DRY SOUTHERN SIDE OF THE SUNRISE
SIDE. CANNOT COMPLETELY RULE OUT AN ISOLATED SEVERE EVENT...
HOWEVER...WITH SUCH DYNAMICS AND CORE OF NEAR 50 KNOTS DEEP LAYER
SHEAR ACROSS EASTERN UPPER. TEMPERATURES REMAIN RATHER TRICKY GIVEN
RAIN AND ABUNDANT CLOUD COVER. INHERITED HIGHS IN THE UPPER
60S/LOWER-MIDDLE 70S AS GOOD A STARTING POINT AS ANY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
OVERVIEW: HEMISPHERIC PATTERN HAS EVOLVED INTO A 5-WAVE LONG WAVE
CONFIGURATION WITH ONE LONG WAVE TROUGH AXIS STRETCHING DOWN THROUGH
EASTERN NOAM. RIDGING ACROSS THE WESTERN CONUS WHERE THE WARM AIR
RESIDES...LINKING BACK TO TROUGHINESS IN THE GULF OF ALASKA AND THE
EASTERN PACIFIC. 5-WAVE PATTERN FORECAST TO REMAIN ESSENTIALLY
UNCHANGED THROUGH THE UPCOMING SEVEN DAYS BUT WITH SLOW WESTWARD
RETROGRESSION OF THE EASTERN NOAM TROUGH INTO THE PLAINS THROUGH THE
WEEKEND AND INTO NEXT WEEK. SHORT WAVE TROUGH AND POCKET OF SOME
FAIRLY CHILLY AIR STILL SLATED TO SETTLE INTO THE GREAT LAKES FOR
THIS WEEKEND...WHICH WILL BE INTERESTING. WARMER AIR DOES MAKE A
RETURN NEXT WEEK AS THE PATTERN FLATTENS ACROSS THE CONUS...BUT JUST
GETS BACK TO NEAR NORMAL.
FRIDAY NIGHT...TRANSITION PERIOD AS SHORT WAVE TROUGH DEEPENS AND
DIGS INTO THE GREAT LAKES PUSHING A SFC LOW AND COLD FRONT THROUGH
THE REGION. SYSTEM HAS SOME STRONG STORM POTENTIAL WITH A NICE PULSE
OF QG-UPWARD FORCING AND DECENT LOW LEVEL CONVERGENCE ALONG THE
FRONT AND SFC LOW WHICH IS SLATED TO TRACK THROUGH NRN LAKE
MICHIGAN/TIP OF THE MITT/EASTERN UPPER FRIDAY AFTERNOON/EVENING.
COUPLED WITH 30 TO 50 KNOT MID LEVEL WINDS AND RESULTING 0-6KM BULK
SHEAR VALUES IN EXCESS OF 30 KNOTS...ANY STORMS THAT FORM WILL HAVE
POTENTIAL TO GET ORGANIZED. BUT...INSTABILITY IS ONCE AGAIN AN
ISSUE. FORECAST SOUNDINGS (EVEN UNMODIFIED) ARE NOT THAT IMPRESSIVE
IN THE INSTABILITY DEPARTMENT AND EVEN RAW MODEL MLCAPE VALUES ARE
LARGELY UNDER 500 J/KG. NOT GREAT. NO SURPRISE THAT BETTER
INSTABILITY WILL RESIDE ACROSS EASTERN/SOUTHERN WISCONSIN DOWN INTO
LOWER MICHIGAN AND THE OHIO VALLEY AND SUSPECT BETTER ORGANIZED
CONVECTION WILL ONCE AGAIN OCCUR IN THOSE AREAS. THAT SAID...IF WE
CAN GET CONVECTION TO FIRE...ANY STORMS COULD PRODUCE GUSTY WINDS
AND SOME HAIL.
SATURDAY AND SUNDAY...WELCOME FALL. FOLLOWING FROPA...POCKET OF
CHILLY AIR (+3C TO +6C 850 MB AIR) DESCENDS INTO THE GREAT LAKES
SATURDAY SETTLING OVERHEAD FOR SUNDAY. SATURDAY STILL LOOKING LIKE A
TRANSITION DAY AS COLD ADVECTION PROCEEDS THROUGH THE DAY AND PARTS
OF THE CWA (SE COUNTIES) MAY SQUEAK TOUCH THE 70S. COULD ACTUALLY
START THE DAY WITH SOME SUNSHINE AS MID LEVEL DRY SLOT WORKS THROUGH
THE AREA. BUT WITH LAKE SFC TEMPS RUNNING +17C TO +20C...CLOUDY
SKIES ARE CERTAIN TO DEVELOP ALONG WITH AT LEAST A CHANCE FOR HYBRID
LAKE/HEATING INDUCED RAIN SHOWERS SATURDAY AFTERNOON. THAT
SAID...DEPTH OF THE COLD AIR IS NOT TERRIBLY IMPRESSIVE WITH A BIT
OF A WARMER CAPPING LAYER ALOFT WHICH MAY PUT THE BRAKES ON
LAKE/LAND BASED CONVECTION SATURDAY AFTERNOON. HENCE WILL KEEP POPS
ON THE LOW SIDE FOR SATURDAY. SUNDAY LOOKS BETTER FOR SHOWERS AS
WARMER LAYER ALOFT IS ERODED ALONG WITH FLAT OUT CLOUDY SKIES AND A
TRUE FALL-LIKE FEEL. HAVE HIGHS ON SUNDAY RANGING FROM THE MID 50S
TO MID 60S.
WATERSPOUT POTENTIAL...WOULD BE MORE IMPRESSIVE IF THE CONVECTIVE
DEPTH WAS DEEPER (PER SZILAGYI WATERSPOUT NOMOGRAM). WILL STILL
HIGHLIGHT THE CHANCE FOR WATERSPOUTS IN THE HAZARDOUS WEATHER
OUTLOOK AS WELL AS IN THE FORECAST FOR BOTH SATURDAY AND SUNDAY...
BUT THE POTENTIAL DOES NOT LOOK AS GOOD AS IT LOOKED A DAY OR TWO
AGO BY VIRTUE OF THE SHALLOWER COLD AIR.
MONDAY THROUGH THURSDAY...IMPROVEMENT FOR THE START THE NEXT WORK
WEEK WITH HIGH PRESSURE AND LOW AMPLITUDE RIDGING BUILDING ACROSS
THE REGION FOR MONDAY AND TUESDAY...ALONG WITH TEMPS REBOUNDING INTO
THE 70S (STILL BELOW NORMAL). NRN STREAM SYSTEM SLATED TO SLOWLY DIP
INTO THE REGION WEDNESDAY AND THURSDAY...SLOWER THAN IN PREVIOUS
SOLUTIONS. BUT THIS WILL BRING LOW END CHANCES FOR SHOWERS BACK INTO
THE FORECAST TO ROUND OUT THE EXTENDED FORECAST...WITH TEMPS RUNNING
JUST A LITTLE BELOW NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 731 PM EDT THU JUL 25 2013
SUMMARY: LOW PRESSURE NOW OVER NORTHERN MINNESOTA WILL STRENGTHEN AS
IT PUSHES INTO THE UPPER GREAT LAKES REGION...WITH A STRONG COLD
FRONT APPROACHING THE REGION FROM THE WEST BY LATE DAY FRIDAY. THIS
FRONT WILL BRING SHOWERS AND THUNDERSTORMS TO ALL TERMINALS BY THE
END OF THE COMING TAF PERIOD...ALONG WITH DETERIORATING FLYING
CONDITIONS.
RESTRICTIONS: VFR ALL SITES ATTM WITH VFR EXPECTED TO CONTINUE
THROUGH THE OVERNIGHT HOURS. SHOWERS WILL ATTEMPT TO MAKE THE TREK
ACROSS LAKE MICHIGAN THIS EVENING...AND WILL LIKELY REACH PLN AFTER
MIDNIGHT...WITH SOME ACTIVITY POTENTIALLY REACHING TVC/MBL BEFORE
DAYBREAK. AT THIS TIME...EXPECT ANY OVERNIGHT ACTIVITY TO REMAIN
GENERALLY UNRESTRICTED. ON FRIDAY....SHOWERS /AND EMBEDDED
THUNDERSTORMS/ WILL INCREASE IN COVERAGE AND MOVE FROM WEST TO
EAST...WITH MVFR CIGS/VSBYS DEVELOPING BY EARLY AFTERNOON
PLN/TVC/MBL AND DURING THE AFTERNOON AT APN.
THUNDER: CHANCES NOT LOOKING GREAT FOR MUCH THUNDER...BEST SHOT WILL
BE AT APN /FRONT ARRIVES HERE LAST/ FRIDAY AFTERNOON. CHANCES FOR
OCCURRENCE TOO LOW AT THIS STAGE TO INCLUDE EXPLICIT MENTION IN THE
TAFS.
LLWS: LOW LEVEL JET WILL STRENGTHEN OVERNIGHT AS LOW PRESSURE
STRENGTHENS TO OUR NORTH AND WEST. THIS SHOULD FAVOR THE
DEVELOPMENT OF LLWS OVERNIGHT WITH 1.5KFT WINDS REACHING 30KTS FROM
THE SOUTHWEST...BUT NOT UNTIL MIDNIGHT AND AFTER. ANY SHEAR LAYER
WILL MIX OUT FRIDAY MORNING.
WINDS: LOCAL LAKE BREEZES AROUND 10KTS /WITH GUSTS TO 15KTS/ WILL
SUBSIDE THIS EVENING WITH SOUTHERLY WINDS 5KTS OR LESS /LIKELY
BECOMING LIGHT-VARIABLE FOR A TIME DURING THE FIRST HALF OF THE
NIGHT/. SOUTH-SOUTHWEST WINDS WILL STRENGTHEN TO 10G18KTS FOR THE
DAY ON FRIDAY...WITH A SHIFT TO WEST OCCURRING SHORTLY AFTER THE END
OF THIS TAF PERIOD.
&&
.MARINE...
ISSUED AT 409 PM EDT THU JUL 25 2013
SOUTH WINDS WILL CONTINUE ACROSS THE BIG WATERS TONIGHT
INTO FRIDAY...BUT LOOK TO REMAIN BELOW SCA LEVELS. LONG AND
PERSISTENT SOUTHERLY FETCH WILL RESULT IN SOME CHOPPY
WATERS...ESPECIALLY ACROSS THE NORTH HALF OF LAKE MICHIGAN. WILL
NEED TO MONITOR...BUT THESE ALSO LOOK TO REMAIN JUST BELOW SCA
LEVELS. STRONG COLD FRONT PUSHES ACROSS THE AREA FRIDAY NIGHT. WEST
WINDS TO FOLLOW INTO THIS WEEKEND...AT TIMES GUSTY. WILL NEED TO
MONITOR WATERSPOUT POTENTIAL THIS WEEKEND AS UNSEASONABLY STRONG
UPPER LEVEL LOW PRESSURE WOBBLES OVERHEAD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...BA
AVIATION...ARNOTT
MARINE...MB
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
818 PM EDT THU JUL 25 2013
.SYNOPSIS...
ISSUED AT 409 PM EDT THU JUL 25 2013
HIGH PRESSURE IS PULLING OFF TO THE NORTHEAST THIS EVENING...
ALLOWING A STORM SYSTEM THAT IS ORGANIZING OVER THE PLAINS TO TAKE
AIM ON THE GREAT LAKES. THIS AREA OF LOW PRESSURE WILL MOVE OVER
THE AREA TONIGHT AND INTO FRIDAY...GENERATING BELOW NORMAL
TEMPERATURES AND MUCH NEEDED RAINFALL ACROSS NORTHERN MICHIGAN.
THIS STORM SYSTEM WILL MOVE SLOWLY...KEEPING UNSETTLED AUTUMN LIKE
WEATHER IN THE AIR THROUGH THE WEEKEND.
&&
.UPDATE...
ISSUED AT 808 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: IMPRESSIVE CONVECTIVE GROWTH OVER CENTRAL UPPER
OVER THE PAST HOUR HAS LED TO AN EXPANDING BAND OF RETURNS
SPREADING EAST TOWARDS CHIP/MACK. WHILE AIRMASS DOWNSTAIRS
CONTINUES TO BE FAIRLY DRY /00Z RAOB IN PROGRESS/ THINK THAT SOME
OF THESE RETURNS WILL REACH THE GROUND OVER THE NEXT 1-2 HOURS AND
HAVE SPED UP POPS HERE ACCORDINGLY. WILL ALSO ADJUST OVERNIGHT
POPS TO SPEED UP EASTWARD PROGRESS OVER EASTERN UPPER AND SLOW IT
TO THE SOUTH OF M-32 IN LINE WITH DEVELOPING CONVECTION OVER
WESTERN UPPER...WHICH SHOULD CONTINUE TO SLIDE EAST GIVEN GOOD
DYNAMIC FORCING...IN TANDEM WITH ARRIVING DEEPER MOISTURE.
DESPITE ONGOING WARNINGS WEST OF LAKE MICHIGAN...SEVERE THREAT
WILL DIMINISH MARKEDLY AS THIS CONVECTION SPREADS EAST. BEST
CHANCE FOR THUNDER WILL COME WELL AFTER MIDNIGHT AS MUCAPE PLUME
OVER WISCONSIN GETS TUGGED NORTH TOWARDS EASTERN UPPER AS
CONVECTIVE DEBRIS PUSHES EAST.
UPDATE ISSUED AT 659 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: PRIMARY CHANGES HAVE BEEN TO NEAR TERM SKY
TRENDS AS MANY SPOTS EAST OF I-75 ENJOYING ONLY A FEW CLOUDS TO
END THE DAY. CONVECTION CONTINUES TO FIRE ALONG LEADING EDGE OF
DEEPER MOISTURE ALOFT WITH MUCAPE PLUME INTERACTING WITH
INCREASING FLOW ALOFT TO PRODUCE A FEW ROBUST CELLS. HRRR WANTS TO
BRING A SLUG OF ACTIVITY IN HERE OVERNIGHT /DECAYING AS IT HEADS
EAST/...BUT NOT READY TO BITE ON THIS YET GIVEN LACK OF
DEVELOPMENT OVER CENTRAL WISCONSIN. THUS...WILL WATCH THE NEXT 1-2
HOURS OF CONVECTIVE EVOLUTION AND MAKE POP ADJUSTMENTS AT THAT
POINT. IF SUBSTANTIAL RAINFALL CANNOT REACH INTO NORTHERN
LOWER...COULD SEE LOW TEMPS NEEDING UPWARD ADJUSTMENT WITH SOME
REMAINING GRADIENT AND TOP-DOWN SATURATION INCREASING CLOUDS
ALOFT.
DESPITE UPSTREAM WARNINGS...SEE LITTLE SEVERE THREAT THIS FAR EAST
AS INSTABILITY PLUME WILL QUICKLY WANE AS IT FOLDS INTO VERY DRY
LLEVEL AIRMASS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
BIG OLE` CHANGES A COMING...AN UNFORTUNATE FACT WELL DISPLAYED ON
AFTERNOON NOAM WATER VAPOR IMAGERY. PATTERN AMPLIFICATION KICKING
INTO FULL GEAR PER SUCH...WITH LEAD CHARGING SHORTWAVE KICKING OUT
OF SOUTHERN MANITOBA...WITH SECONDARY SLUG OF ENERGY JUST UPSTREAM.
THESE WILL EVENTUALLY MORPH INTO AN UNSEASONABLY STRONG UPPER LEVEL
LOW OVER THE NORTHERN LAKES FOR THIS UPCOMING WEEKEND...BRINGING
WITH IT WEATHER MUCH MORE REPRESENTATIVE OF SEPTEMBER THAN JULY.
ATTENDANT SURFACE REFLECTION ATTEMPTING TO TAKE SHAPE...WITH
ELONGATED LOW PRESSURE OVER NORTHERN MINNESOTA AND A DEVELOPING COLD
FRONT ARCHING BACK SOUTHWEST IN THROUGH THE CENTRAL PLAINS.
PRE-FRONTAL MOISTURE ADVECTION NOT OVERLY IMPRESSIVE JUST YET...WITH
ONLY LOWER 60 DEWPOINTS BACK ACROSS THE FAR WESTERN LAKES. AS A
RESULT...UPSTREAM SHOWER AND STORM COVERAGE HAS BEEN SOMEWHAT ON THE
LEAN SIDE...WITH BEST RAIN COVERAGE REMAINING WELL TO OUR NORTH AND
NORTHWEST. FORECAST CONCERNS REMAIN FOCUSED ON INCREASING...AND MUCH
NEEDED...RAIN AND STORM CHANCES THROUGH FRIDAY AS UPSTREAM SYSTEM
FURTHER CONGEALS.
WOULD EXPECT UPWARD TREND IN UPSTREAM RADAR ACTIVITY THIS EVENING AS
INCREASING MOISTURE ADVECTION BECOMES TUCKED UNDER NICE SLUG OF
DEEPENING MID AND UPPER LEVEL SUPPORT. UPSTREAM FORCING/MOISTURE
SPREADS SLOWLY EAST THROUGH THE OVERNIGHT...WITH ATTENDANT THETA-E
RIDGING ARCHING NORTHEAST...BISECTING NORTHERN MICHIGAN BY MORNING.
DIFLUENT MID LEVEL FLOW/UPTICK IN UPWARD QG SUPPORT AND SIMPLE DEEP
LAYER MOISTURE ADVECTION SHOULD SUPPORT UPSTREAM SHOWERS TO SPREAD
EAST...AT LEAST SPREADING ACROSS NORTHWEST SECTIONS OF THE AREA
THROUGH THE OVERNIGHT. SOUTHEAST THIRD OF THE AREA EXPECTED TO
REMAIN DRY...JUST A TOUCH TOO FAR REMOVED FROM BEST JUXTAPOSITION OF
THE ABOVE...ALONG WITH SOME LINGERING SUB H8 DRY AIR. THUNDER
CHANCES NOT OVERWHELMING...BUT NOT ZERO EITHER...WITH CORRIDOR OF
SEVERAL HUNDRED J/KG OF MU CAPE TIED TO ABOVE DYNAMICS. ANY SEVERE
THREAT LIKELY TO REMAIN UPSTREAM WHERE STORMS WILL INITIALLY BE
SURFACE BASED.
DYNAMICS CONTINUE TO RATCHET UP HEADING THROUGH FRIDAY WITH UPSTREAM
SHORTWAVE DEEPENING AND TAKING ON A NEUTRAL/NEGATIVE TILT OVER
WISCONSIN. BACKSIDE CAA STRENGTHENS LOW LEVEL TEMPERATURE
GRADIENT...WITH A RATHER POTENT COLD FRONT TAKING SHAPE JUST
DOWNSTREAM OF PARENT MID LEVEL TROUGH AXIS. LOW PRESSURE DEVELOPING
AND RIDING NORTHEAST ALONG THIS FRONT INTO EASTERN LAKE SUPERIOR
WILL INITIALLY SLOW THE FRONTS EASTWARD PROGRESS FRIDAY
AFTERNOON...LIKELY ONLY REACHING CENTRAL LAKE MICHIGAN BY EVENING.
SHOWERS SHOULD ONLY INCREASE IN COVERAGE...WITH THE
STEADIEST/HEAVIEST RAINS TARGETING EASTERN UPPER/FAR NORTHWEST LOWER
MICHIGAN WHERE STRONGEST DEEP LAYER CONVERGENCE AND MOISTURE
ADVECTION ARE ALIGNED. SEVERE THREAT HIGHLY PREDICATED BY CHANCES
FOR DIURNAL DESTABILIZATION. NOT EXPECTING MUCH OPPORTUNITY FOR
SUCH...WITH CROSS SECTION MOISTURE PROGS SUPPORTING A MOSTLY CLOUDY
DAY...EVEN ACROSS THE RELATIVELY DRY SOUTHERN SIDE OF THE SUNRISE
SIDE. CANNOT COMPLETELY RULE OUT AN ISOLATED SEVERE EVENT...
HOWEVER...WITH SUCH DYNAMICS AND CORE OF NEAR 50 KNOTS DEEP LAYER
SHEAR ACROSS EASTERN UPPER. TEMPERATURES REMAIN RATHER TRICKY GIVEN
RAIN AND ABUNDANT CLOUD COVER. INHERITED HIGHS IN THE UPPER
60S/LOWER-MIDDLE 70S AS GOOD A STARTING POINT AS ANY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
OVERVIEW: HEMISPHERIC PATTERN HAS EVOLVED INTO A 5-WAVE LONG WAVE
CONFIGURATION WITH ONE LONG WAVE TROUGH AXIS STRETCHING DOWN THROUGH
EASTERN NOAM. RIDGING ACROSS THE WESTERN CONUS WHERE THE WARM AIR
RESIDES...LINKING BACK TO TROUGHINESS IN THE GULF OF ALASKA AND THE
EASTERN PACIFIC. 5-WAVE PATTERN FORECAST TO REMAIN ESSENTIALLY
UNCHANGED THROUGH THE UPCOMING SEVEN DAYS BUT WITH SLOW WESTWARD
RETROGRESSION OF THE EASTERN NOAM TROUGH INTO THE PLAINS THROUGH THE
WEEKEND AND INTO NEXT WEEK. SHORT WAVE TROUGH AND POCKET OF SOME
FAIRLY CHILLY AIR STILL SLATED TO SETTLE INTO THE GREAT LAKES FOR
THIS WEEKEND...WHICH WILL BE INTERESTING. WARMER AIR DOES MAKE A
RETURN NEXT WEEK AS THE PATTERN FLATTENS ACROSS THE CONUS...BUT JUST
GETS BACK TO NEAR NORMAL.
FRIDAY NIGHT...TRANSITION PERIOD AS SHORT WAVE TROUGH DEEPENS AND
DIGS INTO THE GREAT LAKES PUSHING A SFC LOW AND COLD FRONT THROUGH
THE REGION. SYSTEM HAS SOME STRONG STORM POTENTIAL WITH A NICE PULSE
OF QG-UPWARD FORCING AND DECENT LOW LEVEL CONVERGENCE ALONG THE
FRONT AND SFC LOW WHICH IS SLATED TO TRACK THROUGH NRN LAKE
MICHIGAN/TIP OF THE MITT/EASTERN UPPER FRIDAY AFTERNOON/EVENING.
COUPLED WITH 30 TO 50 KNOT MID LEVEL WINDS AND RESULTING 0-6KM BULK
SHEAR VALUES IN EXCESS OF 30 KNOTS...ANY STORMS THAT FORM WILL HAVE
POTENTIAL TO GET ORGANIZED. BUT...INSTABILITY IS ONCE AGAIN AN
ISSUE. FORECAST SOUNDINGS (EVEN UNMODIFIED) ARE NOT THAT IMPRESSIVE
IN THE INSTABILITY DEPARTMENT AND EVEN RAW MODEL MLCAPE VALUES ARE
LARGELY UNDER 500 J/KG. NOT GREAT. NO SURPRISE THAT BETTER
INSTABILITY WILL RESIDE ACROSS EASTERN/SOUTHERN WISCONSIN DOWN INTO
LOWER MICHIGAN AND THE OHIO VALLEY AND SUSPECT BETTER ORGANIZED
CONVECTION WILL ONCE AGAIN OCCUR IN THOSE AREAS. THAT SAID...IF WE
CAN GET CONVECTION TO FIRE...ANY STORMS COULD PRODUCE GUSTY WINDS
AND SOME HAIL.
SATURDAY AND SUNDAY...WELCOME FALL. FOLLOWING FROPA...POCKET OF
CHILLY AIR (+3C TO +6C 850 MB AIR) DESCENDS INTO THE GREAT LAKES
SATURDAY SETTLING OVERHEAD FOR SUNDAY. SATURDAY STILL LOOKING LIKE A
TRANSITION DAY AS COLD ADVECTION PROCEEDS THROUGH THE DAY AND PARTS
OF THE CWA (SE COUNTIES) MAY SQUEAK TOUCH THE 70S. COULD ACTUALLY
START THE DAY WITH SOME SUNSHINE AS MID LEVEL DRY SLOT WORKS THROUGH
THE AREA. BUT WITH LAKE SFC TEMPS RUNNING +17C TO +20C...CLOUDY
SKIES ARE CERTAIN TO DEVELOP ALONG WITH AT LEAST A CHANCE FOR HYBRID
LAKE/HEATING INDUCED RAIN SHOWERS SATURDAY AFTERNOON. THAT
SAID...DEPTH OF THE COLD AIR IS NOT TERRIBLY IMPRESSIVE WITH A BIT
OF A WARMER CAPPING LAYER ALOFT WHICH MAY PUT THE BRAKES ON
LAKE/LAND BASED CONVECTION SATURDAY AFTERNOON. HENCE WILL KEEP POPS
ON THE LOW SIDE FOR SATURDAY. SUNDAY LOOKS BETTER FOR SHOWERS AS
WARMER LAYER ALOFT IS ERODED ALONG WITH FLAT OUT CLOUDY SKIES AND A
TRUE FALL-LIKE FEEL. HAVE HIGHS ON SUNDAY RANGING FROM THE MID 50S
TO MID 60S.
WATERSPOUT POTENTIAL...WOULD BE MORE IMPRESSIVE IF THE CONVECTIVE
DEPTH WAS DEEPER (PER SZILAGYI WATERSPOUT NOMOGRAM). WILL STILL
HIGHLIGHT THE CHANCE FOR WATERSPOUTS IN THE HAZARDOUS WEATHER
OUTLOOK AS WELL AS IN THE FORECAST FOR BOTH SATURDAY AND SUNDAY...
BUT THE POTENTIAL DOES NOT LOOK AS GOOD AS IT LOOKED A DAY OR TWO
AGO BY VIRTUE OF THE SHALLOWER COLD AIR.
MONDAY THROUGH THURSDAY...IMPROVEMENT FOR THE START THE NEXT WORK
WEEK WITH HIGH PRESSURE AND LOW AMPLITUDE RIDGING BUILDING ACROSS
THE REGION FOR MONDAY AND TUESDAY...ALONG WITH TEMPS REBOUNDING INTO
THE 70S (STILL BELOW NORMAL). NRN STREAM SYSTEM SLATED TO SLOWLY DIP
INTO THE REGION WEDNESDAY AND THURSDAY...SLOWER THAN IN PREVIOUS
SOLUTIONS. BUT THIS WILL BRING LOW END CHANCES FOR SHOWERS BACK INTO
THE FORECAST TO ROUND OUT THE EXTENDED FORECAST...WITH TEMPS RUNNING
JUST A LITTLE BELOW NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 731 PM EDT THU JUL 25 2013
SUMMARY: LOW PRESSURE NOW OVER NORTHERN MINNESOTA WILL STRENGTHEN AS
IT PUSHES INTO THE UPPER GREAT LAKES REGION...WITH A STRONG COLD
FRONT APPROACHING THE REGION FROM THE WEST BY LATE DAY FRIDAY. THIS
FRONT WILL BRING SHOWERS AND THUNDERSTORMS TO ALL TERMINALS BY THE
END OF THE COMING TAF PERIOD...ALONG WITH DETERIORATING FLYING
CONDITIONS.
RESTRICTIONS: VFR ALL SITES ATTM WITH VFR EXPECTED TO CONTINUE
THROUGH THE OVERNIGHT HOURS. SHOWERS WILL ATTEMPT TO MAKE THE TREK
ACROSS LAKE MICHIGAN THIS EVENING...AND WILL LIKELY REACH PLN AFTER
MIDNIGHT...WITH SOME ACTIVITY POTENTIALLY REACHING TVC/MBL BEFORE
DAYBREAK. AT THIS TIME...EXPECT ANY OVERNIGHT ACTIVITY TO REMAIN
GENERALLY UNRESTRICTED. ON FRIDAY....SHOWERS /AND EMBEDDED
THUNDERSTORMS/ WILL INCREASE IN COVERAGE AND MOVE FROM WEST TO
EAST...WITH MVFR CIGS/VSBYS DEVELOPING BY EARLY AFTERNOON
PLN/TVC/MBL AND DURING THE AFTERNOON AT APN.
THUNDER: CHANCES NOT LOOKING GREAT FOR MUCH THUNDER...BEST SHOT WILL
BE AT APN /FRONT ARRIVES HERE LAST/ FRIDAY AFTERNOON. CHANCES FOR
OCCURRENCE TOO LOW AT THIS STAGE TO INCLUDE EXPLICIT MENTION IN THE
TAFS.
LLWS: LOW LEVEL JET WILL STRENGTHEN OVERNIGHT AS LOW PRESSURE
STRENGTHENS TO OUR NORTH AND WEST. THIS SHOULD FAVOR THE
DEVELOPMENT OF LLWS OVERNIGHT WITH 1.5KFT WINDS REACHING 30KTS FROM
THE SOUTHWEST...BUT NOT UNTIL MIDNIGHT AND AFTER. ANY SHEAR LAYER
WILL MIX OUT FRIDAY MORNING.
WINDS: LOCAL LAKE BREEZES AROUND 10KTS /WITH GUSTS TO 15KTS/ WILL
SUBSIDE THIS EVENING WITH SOUTHERLY WINDS 5KTS OR LESS /LIKELY
BECOMING LIGHT-VARIABLE FOR A TIME DURING THE FIRST HALF OF THE
NIGHT/. SOUTH-SOUTHWEST WINDS WILL STRENGTHEN TO 10G18KTS FOR THE
DAY ON FRIDAY...WITH A SHIFT TO WEST OCCURRING SHORTLY AFTER THE END
OF THIS TAF PERIOD.
&&
.MARINE...
ISSUED AT 409 PM EDT THU JUL 25 2013
SOUTH WINDS WILL CONTINUE ACROSS THE BIG WATERS TONIGHT
INTO FRIDAY...BUT LOOK TO REMAIN BELOW SCA LEVELS. LONG AND
PERSISTENT SOUTHERLY FETCH WILL RESULT IN SOME CHOPPY
WATERS...ESPECIALLY ACROSS THE NORTH HALF OF LAKE MICHIGAN. WILL
NEED TO MONITOR...BUT THESE ALSO LOOK TO REMAIN JUST BELOW SCA
LEVELS. STRONG COLD FRONT PUSHES ACROSS THE AREA FRIDAY NIGHT. WEST
WINDS TO FOLLOW INTO THIS WEEKEND...AT TIMES GUSTY. WILL NEED TO
MONITOR WATERSPOUT POTENTIAL THIS WEEKEND AS UNSEASONABLY STRONG
UPPER LEVEL LOW PRESSURE WOBBLES OVERHEAD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...BA
AVIATION...ARNOTT
MARINE...MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
732 PM EDT THU JUL 25 2013
.SYNOPSIS...
ISSUED AT 409 PM EDT THU JUL 25 2013
HIGH PRESSURE IS PULLING OFF TO THE NORTHEAST THIS EVENING...
ALLOWING A STORM SYSTEM THAT IS ORGANIZING OVER THE PLAINS TO TAKE
AIM ON THE GREAT LAKES. THIS AREA OF LOW PRESSURE WILL MOVE OVER
THE AREA TONIGHT AND INTO FRIDAY...GENERATING BELOW NORMAL
TEMPERATURES AND MUCH NEEDED RAINFALL ACROSS NORTHERN MICHIGAN.
THIS STORM SYSTEM WILL MOVE SLOWLY...KEEPING UNSETTLED AUTUMN LIKE
WEATHER IN THE AIR THROUGH THE WEEKEND.
&&
.UPDATE...
ISSUED AT 659 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: PRIMARY CHANGES HAVE BEEN TO NEAR TERM SKY
TRENDS AS MANY SPOTS EAST OF I-75 ENJOYING ONLY A FEW CLOUDS TO
END THE DAY. CONVECTION CONTINUES TO FIRE ALONG LEADING EDGE OF
DEEPER MOISTURE ALOFT WITH MUCAPE PLUME INTERACTING WITH
INCREASING FLOW ALOFT TO PRODUCE A FEW ROBUST CELLS. HRRR WANTS TO
BRING A SLUG OF ACTIVITY IN HERE OVERNIGHT /DECAYING AS IT HEADS
EAST/...BUT NOT READY TO BITE ON THIS YET GIVEN LACK OF
DEVELOPMENT OVER CENTRAL WISCONSIN. THUS...WILL WATCH THE NEXT 1-2
HOURS OF CONVECTIVE EVOLUTION AND MAKE POP ADJUSTMENTS AT THAT
POINT. IF SUBSTANTIAL RAINFALL CANNOT REACH INTO NORTHERN
LOWER...COULD SEE LOW TEMPS NEEDING UPWARD ADJUSTMENT WITH SOME
REMAINING GRADIENT AND TOP-DOWN SATURATION INCREASING CLOUDS
ALOFT.
DESPITE UPSTREAM WARNINGS...SEE LITTLE SEVERE THREAT THIS FAR EAST
AS INSTABILITY PLUME WILL QUICKLY WANE AS IT FOLDS INTO VERY DRY
LLEVEL AIRMASS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
BIG OLE` CHANGES A COMING...AN UNFORTUNATE FACT WELL DISPLAYED ON
AFTERNOON NOAM WATER VAPOR IMAGERY. PATTERN AMPLIFICATION KICKING
INTO FULL GEAR PER SUCH...WITH LEAD CHARGING SHORTWAVE KICKING OUT
OF SOUTHERN MANITOBA...WITH SECONDARY SLUG OF ENERGY JUST UPSTREAM.
THESE WILL EVENTUALLY MORPH INTO AN UNSEASONABLY STRONG UPPER LEVEL
LOW OVER THE NORTHERN LAKES FOR THIS UPCOMING WEEKEND...BRINGING
WITH IT WEATHER MUCH MORE REPRESENTATIVE OF SEPTEMBER THAN JULY.
ATTENDANT SURFACE REFLECTION ATTEMPTING TO TAKE SHAPE...WITH
ELONGATED LOW PRESSURE OVER NORTHERN MINNESOTA AND A DEVELOPING COLD
FRONT ARCHING BACK SOUTHWEST IN THROUGH THE CENTRAL PLAINS.
PRE-FRONTAL MOISTURE ADVECTION NOT OVERLY IMPRESSIVE JUST YET...WITH
ONLY LOWER 60 DEWPOINTS BACK ACROSS THE FAR WESTERN LAKES. AS A
RESULT...UPSTREAM SHOWER AND STORM COVERAGE HAS BEEN SOMEWHAT ON THE
LEAN SIDE...WITH BEST RAIN COVERAGE REMAINING WELL TO OUR NORTH AND
NORTHWEST. FORECAST CONCERNS REMAIN FOCUSED ON INCREASING...AND MUCH
NEEDED...RAIN AND STORM CHANCES THROUGH FRIDAY AS UPSTREAM SYSTEM
FURTHER CONGEALS.
WOULD EXPECT UPWARD TREND IN UPSTREAM RADAR ACTIVITY THIS EVENING AS
INCREASING MOISTURE ADVECTION BECOMES TUCKED UNDER NICE SLUG OF
DEEPENING MID AND UPPER LEVEL SUPPORT. UPSTREAM FORCING/MOISTURE
SPREADS SLOWLY EAST THROUGH THE OVERNIGHT...WITH ATTENDANT THETA-E
RIDGING ARCHING NORTHEAST...BISECTING NORTHERN MICHIGAN BY MORNING.
DIFLUENT MID LEVEL FLOW/UPTICK IN UPWARD QG SUPPORT AND SIMPLE DEEP
LAYER MOISTURE ADVECTION SHOULD SUPPORT UPSTREAM SHOWERS TO SPREAD
EAST...AT LEAST SPREADING ACROSS NORTHWEST SECTIONS OF THE AREA
THROUGH THE OVERNIGHT. SOUTHEAST THIRD OF THE AREA EXPECTED TO
REMAIN DRY...JUST A TOUCH TOO FAR REMOVED FROM BEST JUXTAPOSITION OF
THE ABOVE...ALONG WITH SOME LINGERING SUB H8 DRY AIR. THUNDER
CHANCES NOT OVERWHELMING...BUT NOT ZERO EITHER...WITH CORRIDOR OF
SEVERAL HUNDRED J/KG OF MU CAPE TIED TO ABOVE DYNAMICS. ANY SEVERE
THREAT LIKELY TO REMAIN UPSTREAM WHERE STORMS WILL INITIALLY BE
SURFACE BASED.
DYNAMICS CONTINUE TO RATCHET UP HEADING THROUGH FRIDAY WITH UPSTREAM
SHORTWAVE DEEPENING AND TAKING ON A NEUTRAL/NEGATIVE TILT OVER
WISCONSIN. BACKSIDE CAA STRENGTHENS LOW LEVEL TEMPERATURE
GRADIENT...WITH A RATHER POTENT COLD FRONT TAKING SHAPE JUST
DOWNSTREAM OF PARENT MID LEVEL TROUGH AXIS. LOW PRESSURE DEVELOPING
AND RIDING NORTHEAST ALONG THIS FRONT INTO EASTERN LAKE SUPERIOR
WILL INITIALLY SLOW THE FRONTS EASTWARD PROGRESS FRIDAY
AFTERNOON...LIKELY ONLY REACHING CENTRAL LAKE MICHIGAN BY EVENING.
SHOWERS SHOULD ONLY INCREASE IN COVERAGE...WITH THE
STEADIEST/HEAVIEST RAINS TARGETING EASTERN UPPER/FAR NORTHWEST LOWER
MICHIGAN WHERE STRONGEST DEEP LAYER CONVERGENCE AND MOISTURE
ADVECTION ARE ALIGNED. SEVERE THREAT HIGHLY PREDICATED BY CHANCES
FOR DIURNAL DESTABILIZATION. NOT EXPECTING MUCH OPPORTUNITY FOR
SUCH...WITH CROSS SECTION MOISTURE PROGS SUPPORTING A MOSTLY CLOUDY
DAY...EVEN ACROSS THE RELATIVELY DRY SOUTHERN SIDE OF THE SUNRISE
SIDE. CANNOT COMPLETELY RULE OUT AN ISOLATED SEVERE EVENT...
HOWEVER...WITH SUCH DYNAMICS AND CORE OF NEAR 50 KNOTS DEEP LAYER
SHEAR ACROSS EASTERN UPPER. TEMPERATURES REMAIN RATHER TRICKY GIVEN
RAIN AND ABUNDANT CLOUD COVER. INHERITED HIGHS IN THE UPPER
60S/LOWER-MIDDLE 70S AS GOOD A STARTING POINT AS ANY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
OVERVIEW: HEMISPHERIC PATTERN HAS EVOLVED INTO A 5-WAVE LONG WAVE
CONFIGURATION WITH ONE LONG WAVE TROUGH AXIS STRETCHING DOWN THROUGH
EASTERN NOAM. RIDGING ACROSS THE WESTERN CONUS WHERE THE WARM AIR
RESIDES...LINKING BACK TO TROUGHINESS IN THE GULF OF ALASKA AND THE
EASTERN PACIFIC. 5-WAVE PATTERN FORECAST TO REMAIN ESSENTIALLY
UNCHANGED THROUGH THE UPCOMING SEVEN DAYS BUT WITH SLOW WESTWARD
RETROGRESSION OF THE EASTERN NOAM TROUGH INTO THE PLAINS THROUGH THE
WEEKEND AND INTO NEXT WEEK. SHORT WAVE TROUGH AND POCKET OF SOME
FAIRLY CHILLY AIR STILL SLATED TO SETTLE INTO THE GREAT LAKES FOR
THIS WEEKEND...WHICH WILL BE INTERESTING. WARMER AIR DOES MAKE A
RETURN NEXT WEEK AS THE PATTERN FLATTENS ACROSS THE CONUS...BUT JUST
GETS BACK TO NEAR NORMAL.
FRIDAY NIGHT...TRANSITION PERIOD AS SHORT WAVE TROUGH DEEPENS AND
DIGS INTO THE GREAT LAKES PUSHING A SFC LOW AND COLD FRONT THROUGH
THE REGION. SYSTEM HAS SOME STRONG STORM POTENTIAL WITH A NICE PULSE
OF QG-UPWARD FORCING AND DECENT LOW LEVEL CONVERGENCE ALONG THE
FRONT AND SFC LOW WHICH IS SLATED TO TRACK THROUGH NRN LAKE
MICHIGAN/TIP OF THE MITT/EASTERN UPPER FRIDAY AFTERNOON/EVENING.
COUPLED WITH 30 TO 50 KNOT MID LEVEL WINDS AND RESULTING 0-6KM BULK
SHEAR VALUES IN EXCESS OF 30 KNOTS...ANY STORMS THAT FORM WILL HAVE
POTENTIAL TO GET ORGANIZED. BUT...INSTABILITY IS ONCE AGAIN AN
ISSUE. FORECAST SOUNDINGS (EVEN UNMODIFIED) ARE NOT THAT IMPRESSIVE
IN THE INSTABILITY DEPARTMENT AND EVEN RAW MODEL MLCAPE VALUES ARE
LARGELY UNDER 500 J/KG. NOT GREAT. NO SURPRISE THAT BETTER
INSTABILITY WILL RESIDE ACROSS EASTERN/SOUTHERN WISCONSIN DOWN INTO
LOWER MICHIGAN AND THE OHIO VALLEY AND SUSPECT BETTER ORGANIZED
CONVECTION WILL ONCE AGAIN OCCUR IN THOSE AREAS. THAT SAID...IF WE
CAN GET CONVECTION TO FIRE...ANY STORMS COULD PRODUCE GUSTY WINDS
AND SOME HAIL.
SATURDAY AND SUNDAY...WELCOME FALL. FOLLOWING FROPA...POCKET OF
CHILLY AIR (+3C TO +6C 850 MB AIR) DESCENDS INTO THE GREAT LAKES
SATURDAY SETTLING OVERHEAD FOR SUNDAY. SATURDAY STILL LOOKING LIKE A
TRANSITION DAY AS COLD ADVECTION PROCEEDS THROUGH THE DAY AND PARTS
OF THE CWA (SE COUNTIES) MAY SQUEAK TOUCH THE 70S. COULD ACTUALLY
START THE DAY WITH SOME SUNSHINE AS MID LEVEL DRY SLOT WORKS THROUGH
THE AREA. BUT WITH LAKE SFC TEMPS RUNNING +17C TO +20C...CLOUDY
SKIES ARE CERTAIN TO DEVELOP ALONG WITH AT LEAST A CHANCE FOR HYBRID
LAKE/HEATING INDUCED RAIN SHOWERS SATURDAY AFTERNOON. THAT
SAID...DEPTH OF THE COLD AIR IS NOT TERRIBLY IMPRESSIVE WITH A BIT
OF A WARMER CAPPING LAYER ALOFT WHICH MAY PUT THE BRAKES ON
LAKE/LAND BASED CONVECTION SATURDAY AFTERNOON. HENCE WILL KEEP POPS
ON THE LOW SIDE FOR SATURDAY. SUNDAY LOOKS BETTER FOR SHOWERS AS
WARMER LAYER ALOFT IS ERODED ALONG WITH FLAT OUT CLOUDY SKIES AND A
TRUE FALL-LIKE FEEL. HAVE HIGHS ON SUNDAY RANGING FROM THE MID 50S
TO MID 60S.
WATERSPOUT POTENTIAL...WOULD BE MORE IMPRESSIVE IF THE CONVECTIVE
DEPTH WAS DEEPER (PER SZILAGYI WATERSPOUT NOMOGRAM). WILL STILL
HIGHLIGHT THE CHANCE FOR WATERSPOUTS IN THE HAZARDOUS WEATHER
OUTLOOK AS WELL AS IN THE FORECAST FOR BOTH SATURDAY AND SUNDAY...
BUT THE POTENTIAL DOES NOT LOOK AS GOOD AS IT LOOKED A DAY OR TWO
AGO BY VIRTUE OF THE SHALLOWER COLD AIR.
MONDAY THROUGH THURSDAY...IMPROVEMENT FOR THE START THE NEXT WORK
WEEK WITH HIGH PRESSURE AND LOW AMPLITUDE RIDGING BUILDING ACROSS
THE REGION FOR MONDAY AND TUESDAY...ALONG WITH TEMPS REBOUNDING INTO
THE 70S (STILL BELOW NORMAL). NRN STREAM SYSTEM SLATED TO SLOWLY DIP
INTO THE REGION WEDNESDAY AND THURSDAY...SLOWER THAN IN PREVIOUS
SOLUTIONS. BUT THIS WILL BRING LOW END CHANCES FOR SHOWERS BACK INTO
THE FORECAST TO ROUND OUT THE EXTENDED FORECAST...WITH TEMPS RUNNING
JUST A LITTLE BELOW NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 731 PM EDT THU JUL 25 2013
SUMMARY: LOW PRESSURE NOW OVER NORTHERN MINNESOTA WILL STRENGTHEN AS
IT PUSHES INTO THE UPPER GREAT LAKES REGION...WITH A STRONG COLD
FRONT APPROACHING THE REGION FROM THE WEST BY LATE DAY FRIDAY. THIS
FRONT WILL BRING SHOWERS AND THUNDERSTORMS TO ALL TERMINALS BY THE
END OF THE COMING TAF PERIOD...ALONG WITH DETERIORATING FLYING
CONDITIONS.
RESTRICTIONS: VFR ALL SITES ATTM WITH VFR EXPECTED TO CONTINUE
THROUGH THE OVERNIGHT HOURS. SHOWERS WILL ATTEMPT TO MAKE THE TREK
ACROSS LAKE MICHIGAN THIS EVENING...AND WILL LIKELY REACH PLN AFTER
MIDNIGHT...WITH SOME ACTIVITY POTENTIALLY REACHING TVC/MBL BEFORE
DAYBREAK. AT THIS TIME...EXPECT ANY OVERNIGHT ACTIVITY TO REMAIN
GENERALLY UNRESTRICTED. ON FRIDAY....SHOWERS /AND EMBEDDED
THUNDERSTORMS/ WILL INCREASE IN COVERAGE AND MOVE FROM WEST TO
EAST...WITH MVFR CIGS/VSBYS DEVELOPING BY EARLY AFTERNOON
PLN/TVC/MBL AND DURING THE AFTERNOON AT APN.
THUNDER: CHANCES NOT LOOKING GREAT FOR MUCH THUNDER...BEST SHOT WILL
BE AT APN /FRONT ARRIVES HERE LAST/ FRIDAY AFTERNOON. CHANCES FOR
OCCURRENCE TOO LOW AT THIS STAGE TO INCLUDE EXPLICIT MENTION IN THE
TAFS.
LLWS: LOW LEVEL JET WILL STRENGTHEN OVERNIGHT AS LOW PRESSURE
STRENGTHENS TO OUR NORTH AND WEST. THIS SHOULD FAVOR THE
DEVELOPMENT OF LLWS OVERNIGHT WITH 1.5KFT WINDS REACHING 30KTS FROM
THE SOUTHWEST...BUT NOT UNTIL MIDNIGHT AND AFTER. ANY SHEAR LAYER
WILL MIX OUT FRIDAY MORNING.
WINDS: LOCAL LAKE BREEZES AROUND 10KTS /WITH GUSTS TO 15KTS/ WILL
SUBSIDE THIS EVENING WITH SOUTHERLY WINDS 5KTS OR LESS /LIKELY
BECOMING LIGHT-VARIABLE FOR A TIME DURING THE FIRST HALF OF THE
NIGHT/. SOUTH-SOUTHWEST WINDS WILL STRENGTHEN TO 10G18KTS FOR THE
DAY ON FRIDAY...WITH A SHIFT TO WEST OCCURRING SHORTLY AFTER THE END
OF THIS TAF PERIOD.
&&
.MARINE...
ISSUED AT 409 PM EDT THU JUL 25 2013
SOUTH WINDS WILL CONTINUE ACROSS THE BIG WATERS TONIGHT
INTO FRIDAY...BUT LOOK TO REMAIN BELOW SCA LEVELS. LONG AND
PERSISTENT SOUTHERLY FETCH WILL RESULT IN SOME CHOPPY
WATERS...ESPECIALLY ACROSS THE NORTH HALF OF LAKE MICHIGAN. WILL
NEED TO MONITOR...BUT THESE ALSO LOOK TO REMAIN JUST BELOW SCA
LEVELS. STRONG COLD FRONT PUSHES ACROSS THE AREA FRIDAY NIGHT. WEST
WINDS TO FOLLOW INTO THIS WEEKEND...AT TIMES GUSTY. WILL NEED TO
MONITOR WATERSPOUT POTENTIAL THIS WEEKEND AS UNSEASONABLY STRONG
UPPER LEVEL LOW PRESSURE WOBBLES OVERHEAD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...BA
AVIATION...ARNOTT
MARINE...MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
705 PM EDT THU JUL 25 2013
.SYNOPSIS...
ISSUED AT 409 PM EDT THU JUL 25 2013
HIGH PRESSURE IS PULLING OFF TO THE NORTHEAST THIS EVENING...
ALLOWING A STORM SYSTEM THAT IS ORGANIZING OVER THE PLAINS TO TAKE
AIM ON THE GREAT LAKES. THIS AREA OF LOW PRESSURE WILL MOVE OVER
THE AREA TONIGHT AND INTO FRIDAY...GENERATING BELOW NORMAL
TEMPERATURES AND MUCH NEEDED RAINFALL ACROSS NORTHERN MICHIGAN.
THIS STORM SYSTEM WILL MOVE SLOWLY...KEEPING UNSETTLED AUTUMN LIKE
WEATHER IN THE AIR THROUGH THE WEEKEND.
&&
.UPDATE...
ISSUED AT 659 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: PRIMARY CHANGES HAVE BEEN TO NEAR TERM SKY
TRENDS AS MANY SPOTS EAST OF I-75 ENJOYING ONLY A FEW CLOUDS TO
END THE DAY. CONVECTION CONTINUES TO FIRE ALONG LEADING EDGE OF
DEEPER MOISTURE ALOFT WITH MUCAPE PLUME INTERACTING WITH
INCREASING FLOW ALOFT TO PRODUCE A FEW ROBUST CELLS. HRRR WANTS TO
BRING A SLUG OF ACTIVITY IN HERE OVERNIGHT /DECAYING AS IT HEADS
EAST/...BUT NOT READY TO BITE ON THIS YET GIVEN LACK OF
DEVELOPMENT OVER CENTRAL WISCONSIN. THUS...WILL WATCH THE NEXT 1-2
HOURS OF CONVECTIVE EVOLUTION AND MAKE POP ADJUSTMENTS AT THAT
POINT. IF SUBSTANTIAL RAINFALL CANNOT REACH INTO NORTHERN
LOWER...COULD SEE LOW TEMPS NEEDING UPWARD ADJUSTMENT WITH SOME
REMAINING GRADIENT AND TOP-DOWN SATURATION INCREASING CLOUDS
ALOFT.
DESPITE UPSTREAM WARNINGS...SEE LITTLE SEVERE THREAT THIS FAR EAST
AS INSTABILITY PLUME WILL QUICKLY WANE AS IT FOLDS INTO VERY DRY
LLEVEL AIRMASS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
BIG OLE` CHANGES A COMING...AN UNFORTUNATE FACT WELL DISPLAYED ON
AFTERNOON NOAM WATER VAPOR IMAGERY. PATTERN AMPLIFICATION KICKING
INTO FULL GEAR PER SUCH...WITH LEAD CHARGING SHORTWAVE KICKING OUT
OF SOUTHERN MANITOBA...WITH SECONDARY SLUG OF ENERGY JUST UPSTREAM.
THESE WILL EVENTUALLY MORPH INTO AN UNSEASONABLY STRONG UPPER LEVEL
LOW OVER THE NORTHERN LAKES FOR THIS UPCOMING WEEKEND...BRINGING
WITH IT WEATHER MUCH MORE REPRESENTATIVE OF SEPTEMBER THAN JULY.
ATTENDANT SURFACE REFLECTION ATTEMPTING TO TAKE SHAPE...WITH
ELONGATED LOW PRESSURE OVER NORTHERN MINNESOTA AND A DEVELOPING COLD
FRONT ARCHING BACK SOUTHWEST IN THROUGH THE CENTRAL PLAINS.
PRE-FRONTAL MOISTURE ADVECTION NOT OVERLY IMPRESSIVE JUST YET...WITH
ONLY LOWER 60 DEWPOINTS BACK ACROSS THE FAR WESTERN LAKES. AS A
RESULT...UPSTREAM SHOWER AND STORM COVERAGE HAS BEEN SOMEWHAT ON THE
LEAN SIDE...WITH BEST RAIN COVERAGE REMAINING WELL TO OUR NORTH AND
NORTHWEST. FORECAST CONCERNS REMAIN FOCUSED ON INCREASING...AND MUCH
NEEDED...RAIN AND STORM CHANCES THROUGH FRIDAY AS UPSTREAM SYSTEM
FURTHER CONGEALS.
WOULD EXPECT UPWARD TREND IN UPSTREAM RADAR ACTIVITY THIS EVENING AS
INCREASING MOISTURE ADVECTION BECOMES TUCKED UNDER NICE SLUG OF
DEEPENING MID AND UPPER LEVEL SUPPORT. UPSTREAM FORCING/MOISTURE
SPREADS SLOWLY EAST THROUGH THE OVERNIGHT...WITH ATTENDANT THETA-E
RIDGING ARCHING NORTHEAST...BISECTING NORTHERN MICHIGAN BY MORNING.
DIFLUENT MID LEVEL FLOW/UPTICK IN UPWARD QG SUPPORT AND SIMPLE DEEP
LAYER MOISTURE ADVECTION SHOULD SUPPORT UPSTREAM SHOWERS TO SPREAD
EAST...AT LEAST SPREADING ACROSS NORTHWEST SECTIONS OF THE AREA
THROUGH THE OVERNIGHT. SOUTHEAST THIRD OF THE AREA EXPECTED TO
REMAIN DRY...JUST A TOUCH TOO FAR REMOVED FROM BEST JUXTAPOSITION OF
THE ABOVE...ALONG WITH SOME LINGERING SUB H8 DRY AIR. THUNDER
CHANCES NOT OVERWHELMING...BUT NOT ZERO EITHER...WITH CORRIDOR OF
SEVERAL HUNDRED J/KG OF MU CAPE TIED TO ABOVE DYNAMICS. ANY SEVERE
THREAT LIKELY TO REMAIN UPSTREAM WHERE STORMS WILL INITIALLY BE
SURFACE BASED.
DYNAMICS CONTINUE TO RATCHET UP HEADING THROUGH FRIDAY WITH UPSTREAM
SHORTWAVE DEEPENING AND TAKING ON A NEUTRAL/NEGATIVE TILT OVER
WISCONSIN. BACKSIDE CAA STRENGTHENS LOW LEVEL TEMPERATURE
GRADIENT...WITH A RATHER POTENT COLD FRONT TAKING SHAPE JUST
DOWNSTREAM OF PARENT MID LEVEL TROUGH AXIS. LOW PRESSURE DEVELOPING
AND RIDING NORTHEAST ALONG THIS FRONT INTO EASTERN LAKE SUPERIOR
WILL INITIALLY SLOW THE FRONTS EASTWARD PROGRESS FRIDAY
AFTERNOON...LIKELY ONLY REACHING CENTRAL LAKE MICHIGAN BY EVENING.
SHOWERS SHOULD ONLY INCREASE IN COVERAGE...WITH THE
STEADIEST/HEAVIEST RAINS TARGETING EASTERN UPPER/FAR NORTHWEST LOWER
MICHIGAN WHERE STRONGEST DEEP LAYER CONVERGENCE AND MOISTURE
ADVECTION ARE ALIGNED. SEVERE THREAT HIGHLY PREDICATED BY CHANCES
FOR DIURNAL DESTABILIZATION. NOT EXPECTING MUCH OPPORTUNITY FOR
SUCH...WITH CROSS SECTION MOISTURE PROGS SUPPORTING A MOSTLY CLOUDY
DAY...EVEN ACROSS THE RELATIVELY DRY SOUTHERN SIDE OF THE SUNRISE
SIDE. CANNOT COMPLETELY RULE OUT AN ISOLATED SEVERE EVENT...
HOWEVER...WITH SUCH DYNAMICS AND CORE OF NEAR 50 KNOTS DEEP LAYER
SHEAR ACROSS EASTERN UPPER. TEMPERATURES REMAIN RATHER TRICKY GIVEN
RAIN AND ABUNDANT CLOUD COVER. INHERITED HIGHS IN THE UPPER
60S/LOWER-MIDDLE 70S AS GOOD A STARTING POINT AS ANY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
OVERVIEW: HEMISPHERIC PATTERN HAS EVOLVED INTO A 5-WAVE LONG WAVE
CONFIGURATION WITH ONE LONG WAVE TROUGH AXIS STRETCHING DOWN THROUGH
EASTERN NOAM. RIDGING ACROSS THE WESTERN CONUS WHERE THE WARM AIR
RESIDES...LINKING BACK TO TROUGHINESS IN THE GULF OF ALASKA AND THE
EASTERN PACIFIC. 5-WAVE PATTERN FORECAST TO REMAIN ESSENTIALLY
UNCHANGED THROUGH THE UPCOMING SEVEN DAYS BUT WITH SLOW WESTWARD
RETROGRESSION OF THE EASTERN NOAM TROUGH INTO THE PLAINS THROUGH THE
WEEKEND AND INTO NEXT WEEK. SHORT WAVE TROUGH AND POCKET OF SOME
FAIRLY CHILLY AIR STILL SLATED TO SETTLE INTO THE GREAT LAKES FOR
THIS WEEKEND...WHICH WILL BE INTERESTING. WARMER AIR DOES MAKE A
RETURN NEXT WEEK AS THE PATTERN FLATTENS ACROSS THE CONUS...BUT JUST
GETS BACK TO NEAR NORMAL.
FRIDAY NIGHT...TRANSITION PERIOD AS SHORT WAVE TROUGH DEEPENS AND
DIGS INTO THE GREAT LAKES PUSHING A SFC LOW AND COLD FRONT THROUGH
THE REGION. SYSTEM HAS SOME STRONG STORM POTENTIAL WITH A NICE PULSE
OF QG-UPWARD FORCING AND DECENT LOW LEVEL CONVERGENCE ALONG THE
FRONT AND SFC LOW WHICH IS SLATED TO TRACK THROUGH NRN LAKE
MICHIGAN/TIP OF THE MITT/EASTERN UPPER FRIDAY AFTERNOON/EVENING.
COUPLED WITH 30 TO 50 KNOT MID LEVEL WINDS AND RESULTING 0-6KM BULK
SHEAR VALUES IN EXCESS OF 30 KNOTS...ANY STORMS THAT FORM WILL HAVE
POTENTIAL TO GET ORGANIZED. BUT...INSTABILITY IS ONCE AGAIN AN
ISSUE. FORECAST SOUNDINGS (EVEN UNMODIFIED) ARE NOT THAT IMPRESSIVE
IN THE INSTABILITY DEPARTMENT AND EVEN RAW MODEL MLCAPE VALUES ARE
LARGELY UNDER 500 J/KG. NOT GREAT. NO SURPRISE THAT BETTER
INSTABILITY WILL RESIDE ACROSS EASTERN/SOUTHERN WISCONSIN DOWN INTO
LOWER MICHIGAN AND THE OHIO VALLEY AND SUSPECT BETTER ORGANIZED
CONVECTION WILL ONCE AGAIN OCCUR IN THOSE AREAS. THAT SAID...IF WE
CAN GET CONVECTION TO FIRE...ANY STORMS COULD PRODUCE GUSTY WINDS
AND SOME HAIL.
SATURDAY AND SUNDAY...WELCOME FALL. FOLLOWING FROPA...POCKET OF
CHILLY AIR (+3C TO +6C 850 MB AIR) DESCENDS INTO THE GREAT LAKES
SATURDAY SETTLING OVERHEAD FOR SUNDAY. SATURDAY STILL LOOKING LIKE A
TRANSITION DAY AS COLD ADVECTION PROCEEDS THROUGH THE DAY AND PARTS
OF THE CWA (SE COUNTIES) MAY SQUEAK TOUCH THE 70S. COULD ACTUALLY
START THE DAY WITH SOME SUNSHINE AS MID LEVEL DRY SLOT WORKS THROUGH
THE AREA. BUT WITH LAKE SFC TEMPS RUNNING +17C TO +20C...CLOUDY
SKIES ARE CERTAIN TO DEVELOP ALONG WITH AT LEAST A CHANCE FOR HYBRID
LAKE/HEATING INDUCED RAIN SHOWERS SATURDAY AFTERNOON. THAT
SAID...DEPTH OF THE COLD AIR IS NOT TERRIBLY IMPRESSIVE WITH A BIT
OF A WARMER CAPPING LAYER ALOFT WHICH MAY PUT THE BRAKES ON
LAKE/LAND BASED CONVECTION SATURDAY AFTERNOON. HENCE WILL KEEP POPS
ON THE LOW SIDE FOR SATURDAY. SUNDAY LOOKS BETTER FOR SHOWERS AS
WARMER LAYER ALOFT IS ERODED ALONG WITH FLAT OUT CLOUDY SKIES AND A
TRUE FALL-LIKE FEEL. HAVE HIGHS ON SUNDAY RANGING FROM THE MID 50S
TO MID 60S.
WATERSPOUT POTENTIAL...WOULD BE MORE IMPRESSIVE IF THE CONVECTIVE
DEPTH WAS DEEPER (PER SZILAGYI WATERSPOUT NOMOGRAM). WILL STILL
HIGHLIGHT THE CHANCE FOR WATERSPOUTS IN THE HAZARDOUS WEATHER
OUTLOOK AS WELL AS IN THE FORECAST FOR BOTH SATURDAY AND SUNDAY...
BUT THE POTENTIAL DOES NOT LOOK AS GOOD AS IT LOOKED A DAY OR TWO
AGO BY VIRTUE OF THE SHALLOWER COLD AIR.
MONDAY THROUGH THURSDAY...IMPROVEMENT FOR THE START THE NEXT WORK
WEEK WITH HIGH PRESSURE AND LOW AMPLITUDE RIDGING BUILDING ACROSS
THE REGION FOR MONDAY AND TUESDAY...ALONG WITH TEMPS REBOUNDING INTO
THE 70S (STILL BELOW NORMAL). NRN STREAM SYSTEM SLATED TO SLOWLY DIP
INTO THE REGION WEDNESDAY AND THURSDAY...SLOWER THAN IN PREVIOUS
SOLUTIONS. BUT THIS WILL BRING LOW END CHANCES FOR SHOWERS BACK INTO
THE FORECAST TO ROUND OUT THE EXTENDED FORECAST...WITH TEMPS RUNNING
JUST A LITTLE BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 138 PM EDT THU JUL 25 2013
VFR CONDITIONS UNDER SLOW TOP-DOWN SATURATION REGIME TO CONTINUE
AS UPSTREAM LOW PRESSURE AND ATTENDANT COLD FRONT GRADUALLY BECOME
BETTER ORGANIZED. THESE FEATURES WILL STEADILY PUSH
EAST...BRINGING AN INCREASING SHOWER THREAT TONIGHT INTO
FRIDAY...ESPECIALLY ACROSS WESTERN TAF LOCATIONS. MAY SEE A
RUMBLE OF THUNDER OR TWO...BUT CONFIDENT JUST TOO LOW ON EXACT
TIMING AND AREA COVERAGE TO INCLUDE IN THIS TAF CYCLE. CIGS/VIS
MAY LOWER TO MVFR RANGE AS RAINFALL INCREASES IN INTENSITY LATER
FRIDAY MORNING.
&&
.MARINE...
ISSUED AT 409 PM EDT THU JUL 25 2013
SOUTH WINDS WILL CONTINUE ACROSS THE BIG WATERS TONIGHT
INTO FRIDAY...BUT LOOK TO REMAIN BELOW SCA LEVELS. LONG AND
PERSISTENT SOUTHERLY FETCH WILL RESULT IN SOME CHOPPY
WATERS...ESPECIALLY ACROSS THE NORTH HALF OF LAKE MICHIGAN. WILL
NEED TO MONITOR...BUT THESE ALSO LOOK TO REMAIN JUST BELOW SCA
LEVELS. STRONG COLD FRONT PUSHES ACROSS THE AREA FRIDAY NIGHT. WEST
WINDS TO FOLLOW INTO THIS WEEKEND...AT TIMES GUSTY. WILL NEED TO
MONITOR WATERSPOUT POTENTIAL THIS WEEKEND AS UNSEASONABLY STRONG
UPPER LEVEL LOW PRESSURE WOBBLES OVERHEAD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...BA
AVIATION...MB
MARINE...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
420 PM EDT WED JUL 24 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 419 PM EDT WED JUL 24 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW NW FLOW INTO THE UPPER
GREAT LAKES...RESULTING FROM A RIDGE OVER WRN N AMERICA AND A TROF
OVER ERN NAMERICA. WEAK REMNANT OF SHORTWAVE THAT WAS OVER CNTRL
SASKATCHEWAN 24HRS AGO IS NOW PASSING OVER THE UPPER GREAT LAKES.
12Z KINL SOUNDING SHOWED A CAP AROUND 12.5KFT MSL...AND LATEST SPC
ANALYSIS SHOWS MUCAPE ONLY 100-200J/KG. BOTH DO NOT SUPPORT MUCH OF
A SHRA POTENTIAL. KMQT RADAR IS OUT OF SERVICE UNTIL LATE THU
MORNING/EARLY AFTN WHILE PARTS ARE IN TRANSIT...SO NOT CERTAIN IF
THERE HAS BEEN ANY SHRA OVER W OR CNTRL UPPER MI THIS AFTN. HOWEVER...
KGRB/KDLH RADARS HAVE INDICATED A FEW RETURNS...SO THERE MIGHT BE A
FEW SPRINKLES OR PERHAPS A -SHRA OUT THERE. UPSTREAM...ISOLD/SCT
CONVECTION IS NOTED NW AND N OF LAKE SUPERIOR...TYPICAL FOR
SUMMERTIME NW FLOW. FARTHER UPSTREAM...A LARGER SCALE TROF EXTENDING
FROM WRN HUDSON BAY TO NRN ALBERTA IS DROPPING S. THIS FEATURE WILL
BE THE PLAYER IN THE WEATHER HERE THU THRU SAT.
WITH LOSS OF DAYTIME HEATING...ANY ONGOING ISOLD SHRA/SPRINKLES
WILL DISSIPATE THIS EVENING. HOWEVER...ANOTHER SUBTLE SHORTWAVE IS
NOTED OVER SRN MANITOBA...AND IT IS SUPPORTING MUCH OF THE ISOLD/SCT
SHRA/TSRA ACTIVITY OVER SE MANITOBA INTO ADJACENT NRN ONTARIO/NRN
MN. THIS WAVE COMBINED WITH WAA REGIME COULD HELP MAINTAIN A FEW
SHRA/POSSIBLE TSRA THRU THE NIGHTTIME HRS AS IT CONTINUES TO THE SE.
SO...WILL INCLUDE SCHC POPS OVER THE W LATE IN THE NIGHT.
ON THU...AFOREMENTIONED LARGER SCALE TROF WILL PIVOT SE INTO NRN
ONTARIO AND SRN MANITOBA/SRN SASKATCHEWAN. ASSOCIATED BROAD...BUT
ORGANIZING SFC LOW WILL REACH VCNTY OF WRN LAKE SUPERIOR LATE IN THE
DAY. THERE MAY BE A FEW SHRA/PERHAPS TSRA DURING THE MORNING HRS
WITHIN WAA REGIME. OTHERWISE...BUILDING INSTABILITY IN THE AFTN AND
APPROACHING HEIGHT FALLS AS LARGER SCALE TROF SWINGS CLOSER WILL
LIKELY RESULT IN INCREASING COVERAGE OF SHRA/TSRA DURING THE DAY.
WITH NAM/GFS MLCAPE INCREASING TO UPWARDS OF 1000J/KG AND DEEP LAYER
SHEAR PROGGED AT 30-40KT...EXPECT SOME STORM ORGANIZATION...LEADING
TO THE POSSIBILITY OF A FEW STRONGER STORMS. IF THERE IS SUFFICIENT
DAYTIME HEATING TO RAISE CAPE TO THE MODEL VALUES...THEN THERE WILL
BE THE POTENTIAL FOR ISOLD SVR STORMS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 419 PM EDT WED JUL 24 2013
A LINE OF SHOWERS AND THUNDERSTORMS WILL BE MOVING ACROSS THE AREA
AT THE START OF THE LONG TERM PERIOD. THIS IS DUE TO A TROUGH
DIGGING SOUTHEAST INTO NORTHERN MINNESOTA AND PRODUCING A
BROAD/WEAK LOW PRESSURE SYSTEM MOVING THROUGH THE AREA. THE GENERAL
TREND OVER THE LAST COUPLE OF DAYS IS FOR THE SHORTWAVE AND LOW
TRACK TO BE FARTHER SOUTH...WHICH INFLUENCES THE WEATHER FOR THE
WEEKEND. BEFORE THAT...THE SHOWERS AND THUNDERSTORMS WILL BE MOVING
EAST ACROSS CENTRAL AND EASTERN UPPER MICHIGAN DURING THE EVENING
AND INTO THE OVERNIGHT HOURS. WITH LIMITED INSTABILITY AND LOSS
OF DIURNAL HEATING...THINK THE SEVERE POTENTIAL IS MARGINAL EVEN
THOUGH 0-6KM SHEAR VALUES ARE IN THE 35-40KT RANGE. AS THE FIRST
WAVE OF PRECIPITATION MOVES EAST...THINK THERE WILL BE LINGERING
CLOUDS AND A FEW RAIN SHOWERS OVER THE WEST THROUGH THE NIGHT WITH
THE BROAD/WEAK LOW MOVING OVER THE WESTERN U.P.
SECOND SHORTWAVE WILL ARRIVE ON FRIDAY (WEST MORNING AND EAST
AFTERNOON) AND KICK OFF ANOTHER PERIOD OF NUMEROUS SHOWERS. SINCE
THE LOW WILL HAVE SHIFTED TOWARDS CENTRAL UPPER MICHIGAN...ANY
INSTABILITY (MUCAPE VALUES UNDER 750 J/KG) WILL BE ALIGNED ALONG AND
EAST OF THAT LOCATIONS...SO WILL CONFINE THE BEST THUNDER CHANCES
THERE. SINCE 0-6KM SHEAR VALUES ARE ONLY 15-20KTS...HEAVY RAIN
WOULD BE THE MAIN THREAT.
THIS SECOND SHORTWAVE WILL ALSO CAUSE THE TROUGH TO WRAP UP INTO A
CLOSED LOW OVER THE UPPER GREAT LAKES ON FRIDAY NIGHT AND REMAIN
IN THE AREA INTO SUNDAY MORNING. THIS WILL LEAD TO WEATHER MORE
LIKE LATE SEPTEMBER INSTEAD OF LATE JULY. DURING THAT
TIME...EMBEDDED WAVES AND INCREASED MOISTURE WILL LEAD TO CLOUDY
CONDITIONS...PERIODS OF RAIN (ESPECIALLY OVER THE NORTH
HALF)...GUSTY NORTHWEST WINDS (FRIDAY NIGHT INTO
SATURDAY EVENING)...AND TEMPERATURES WELL BELOW NORMAL (50S AND
LOW 60S SATURDAY). TEMPERATURES ON SATURDAY MAY BE SOMETHING TO
KEEP AN EYE ON...SINCE SOME OF THE RAW MODELS ARE INDICATING HIGHS
IN THE UPPER 40S OR LOW 50S OVER THE NORTHWEST HALF OF THE U.P.
LOOKING AT SOME PAST HIGHS...THE RECORD COLDEST JULY HIGH
TEMPERATURES FOR MANY SITES ARE IN THAT RANGE (NWS MQT 51 IN
2004/1992...CMX 49 IN 1992...IRONWOOD 52 IN 2009/1997).
MOST LIKELY PERIOD FOR DRIER WEATHER WILL BE SUNDAY AFTERNOON INTO
MONDAY AFTERNOON...AS THE UPPER LOW SHIFTS NORTHEAST INTO QUEBEC
AND WEAK HIGH PRESSURE SLIDES ACROSS THE AREA. MODELS CONTINUES TO
STRUGGLE ON THAT TIMING WITH THE SPEED OF THE UPPER LOW
EXITING...WHICH IS USUALLY THE CASE. ONCE THE LOW SHIFTS
NORTHEAST...A SERIES OF SHORTWAVES LOOK TO MOVE ACROSS THE UPPER
GREAT LAKES MONDAY NIGHT INTO TUESDAY NIGHT. WILL CONTINUE TO
MENTION LOW END CHANCE POPS FOR THESE SHORTWAVES MOVING THROUGH.
AFTER THE COOL WEEKEND...TEMPERATURES SHOULD REBOUND TO MORE NORMAL
VALUES FOR THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 136 PM EDT WED JUL 24 2013
VFR CONDITIONS SHOULD BE THE RULE THRU THE FCST PERIOD AT
KIWD/KCMX/KSAW UNLESS SOME PCPN OCCURS. ISOLD SHRA MAY DEVELOP THIS
AFTN BTWN KIWD/KSAW. HOWEVER...THE PROBABILITY OF SHRA AFFECTING
EITHER TERMINAL IS MUCH TOO LOW RIGHT NOW TO INCLUDE ANY MENTION OF
SHRA. BETTER OPPORTUNITY FOR PCPN SHOULD DEVELOP LATER THU MORNING
INTO THE AFTN AS INSTABILITY BUILDS AHEAD OF AN APPROACHING LOW PRES
SYSTEM AND COLD FRONT. FOR NOW...INCLUDED VCNTY SHRA AT ALL
TERMINALS AS A STARTING POINT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EDT WED JUL 24 2013
WITH HIGH PRES DEPARTING TO THE E AND LOW PRES APPROACHING FROM THE
NW...S WINDS WILL BE THE RULE TONIGHT AND THU...THOUGH SPEEDS SHOULD
REMAIN UNDER 20KT. IF THERE ARE ANY STRONGER WINDS...THEY WILL OCCUR
OVER ERN LAKE SUPERIOR THU AFTN/EVENING. ONCE THE LOW MOVES E OF
LAKE SUPERIOR...WINDS WILL SHIFT AROUND TO THE N TO NW FRI. GIVEN
THE INCOMING CHILLY AIR MASS FOR THIS TIME OF YEAR...IT LOOKS LIKE
THERE WILL BE A PERIOD OF 15-25KT WINDS OVER MAINLY CNTRL LAKE
SUPERIOR FRI NIGHT INTO SAT. HOWEVER...IT`S NOT OUT OF THE QUESTION
THAT WINDS COULD BE HIGHER DUE TO THE UNSEASONABLY COOL AIR MASS
PUSHING OVER THE AREA. WINDS WILL DIMINISH SUN/MON AS HIGH PRES
BUILDS INTO THE WRN GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
307 AM EDT WED JUL 24 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 411 PM EDT TUE JUL 23 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE OVER
JAMES BAY. PRES GRADIENT BTWN ITS ASSOCIATED SFC LOW E OF JAMES BAY
AND SFC HIGH PRES OVER NW MN/ERN DAKOTAS HAS RESULTED IN BREEZY N/NW
WINDS TODAY AND MUCH COOLER CONDITIONS COMPARED TO YESTERDAY. PER
WATER VAPOR IMAGERY...IN THE NW FLOW UPSTREAM...THERE ARE A COUPLE
OF SHORTWAVES EVIDENT...ONE OVER ERN MT/WRN ND AND ANOTHER OVER
CNTRL SASKATCHEWAN. THE NRN WAVE MAY BE A FACTOR IN THE WEATHER HERE
ON WED.
A QUIET...COOL NIGHT IS IN STORE TONIGHT AS SFC HIGH PRES SETTLES SE
INTO WI...BRINGING DIMINISHING WINDS FROM W TO E. WITH DECREASING
WINDS...CLEAR SKIES AND PRECIPITABLE WATER 50-70PCT OF NORMAL...
EXPECT A DECENT RADIATIONAL COOLING NIGHT...ESPECIALLY OVER W AND SW
UPPER MI AS WINDS SHOULD DIMINISH TO CALM IN THAT AREA...BEING
CLOSER TO SFC HIGH PRES CENTER. WILL CONTINUE TO SHOW LOWEST TEMPS
IN THAT AREA (40 TO THE LWR 40S). OTHERWISE...MIN TEMPS SHOULD BE IN
THE 40S IN THE INTERIOR TO MOSTLY AROUND 50F ALONG THE GREAT LAKES.
AFTER A QUIET NIGHT...ATTENTION ON WED SHIFTS TO POSSIBLE AFTN
CONVECTION. SUMMERTIME WNW/NW FLOW IS OFTEN A FAVORABLE PATTERN
FOR ISOLD/SCT AFTN CONVECTION AS EVEN THE MOST SUBTLE SHORTWAVES CAN
SPARK SOME PCPN. IF THERE WASN`T A SHORTWAVE PRESENT UPSTREAM...
WOULD HAVE DROPPED PCPN MENTION ON WED...BUT SINCE THERE IS AN
OBVIOUS WAVE CURRENTLY UPSTREAM IN CNTRL SASKATCHEWAN...IT LOOKS
LIKE THERE WILL PROBABLY BE SOME ISOLD AFTN CONVECTION AS THE WAVE
DROPS SE INTO THE AREA. WILL CONTINUE TO HIGHLIGHT SCHC POPS OVER
MAINLY THE INTERIOR W AND CNTRL WHERE THE LIMITED INSTABILITY IS
BEST. NAM/GFS MLCAPES ARE ONLY AS HIGH AS 200-300J/KG DURING THE MID
AFTN...SO THUNDER POTENTIAL APPEARS MINIMAL. HOWEVER...CANADIAN
RADARS CURRENTLY SHOW DECENT RETURNS IN THE VCNTY OF SHORTWAVE IN
SASKATCHEWAN AND SATELLITE IMAGERY SUGGESTS SOME DECENT
CONVECTION...SO THERE MAY BE SOME THUNDER OCCURRING WITH THE WAVE
THIS AFTN. FOR NOW...WILL LEAVE THUNDER MENTION IN THE FCST FOR WED
AND LET LATER SHIFTS REASSESS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 411 PM EDT TUE JUL 23 2013
MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A SHORTWAVE
DROPPING SOUTH-SOUTHEAST THROUGH CENTRAL CANADA ON WEDNESDAY AND
WEDNESDAY NIGHT...WHICH THEN MOVES INTO CENTRAL ONTARIO BY THURSDAY
NIGHT AND CLOSES OFF. THIS UPPER LOW WILL REMAIN IN CENTRAL ONTARIO
INTO SUNDAY BEFORE SHIFTING NORTHEAST INTO ONTARIO FOR THE START OF
THE WORK WEEK.
WEDNESDAY NIGHT WILL BE RELATIVELY QUIET AS ANY DIURNAL CLOUDS AND
SHOWERS DIMINISH FAIRLY QUICKLY DURING THE EVENING. THEN...EXPECT
MID-HIGH CLOUDS TO BE ON THE INCREASE THROUGH THE NIGHT AS THE
SHORTWAVE MOVES INTO SOUTHWEST ONTARIO AND AN ASSOCIATED 1008MB LOW
DEVELOPS EAST OF LAKE WINNIPEG AND SLIDES EAST. AS THE SHORTWAVE
AND SURFACE LOW CONTINUE TO THE EAST-SOUTHEAST ON LATE WEDNESDAY
NIGHT AND THURSDAY...AN ASSOCIATED COLD FRONT WILL SLIDE INTO
WESTERN UPPER MICHIGAN DURING THE AFTERNOON. THAT WILL BE THE AREA
WITH THE BEST OPPORTUNITY FOR SHOWERS/THUNDERSTORMS ON THURSDAY
AFTERNOON AND WILL CONTINUE TO HIGHLIGHT INCREASING POPS TO LIKELY
VALUES DURING THE AFTERNOON.
INSTABILITY LOOKS FAIRLY LIMITED OVER MOST OF THE AREA...WITH MLCAPE
VALUES AROUND 500 J/KG ALTHOUGH MUCAPE VALUES DO APPROACH 1500
J/KG IN SOME MODELS OVER THE WEST AND 09Z SREF ONLY INDICATES A 20
PERCENT CHANCE 1000 J/KG IS REACHED. CAPE IS FAIRLY TALL/SKINNY AS
SEEN IN NCAPE VALUES IN THE 0.05-0.1 RANGE. AS FOR SHEAR...0-6KM AND
EFFECTIVE VALUES ARE ALSO MARGINAL (AROUND 30-35KTS)...ALTHOUGH
THERE IS SOME LOW LEVEL VEERING TO THE WIND. THE STRENGTH OF THE
SHORTWAVE MAY HELP OVERCOME THE MARGINAL INSTABILITY/SHEAR...BUT
THINK THE STORMS WILL PRIMARILY BE SUB SEVERE. THEY WILL LIKELY BE
THE STRONGEST OVER THE FAR WEST...WHERE IT IS CLOSER TO THE
SYNOPTIC AND FRONTAL FORCING. NAM/GFS STORM MOTION VECTORS INDICATE
THE STORMS WILL MOVE FAIRLY QUICKLY TO THE EAST (AROUND 40KTS) AND
HAVE FOLLOWED SUIT WITH THE POPS. BUT THE OVERALL TREND WITH THE
FRONT HAS BEEN SLOWER...WITH IT NOW EXITING EASTERN UPPER MICHIGAN
BETWEEN 09Z-18Z FRIDAY.
MODELS DIFFER SOMEWHAT WITH THE POSITION OF THE SURFACE/UPPER
LOW...BUT THE GENERAL IDEA OF COOL...CYCLONIC FLOW AFFECTING THE
UPPER GREAT LAKES FRIDAY THROUGH SUNDAY MORNING SEEMS REASONABLE.
ANOTHER SHORTWAVE ROTATES AROUND THE UPPER LOW ON FRIDAY AND
PRECIPITATION CHANCES DEPEND ON HOW QUICKLY THE FRONT MOVES
EAST...THE DRY SLOT BEHIND IT...AND ADDITIONAL MOISTURE DROPPING
SOUTHEAST ACROSS WESTERN LAKE SUPERIOR. THESE FEATURES ARE STILL
VARIABLE IN THE MODELS...BUT THE MORNING LOOKS TO HAVE THE BEST
OPPORTUNITY FOR LINGERING SHOWERS OVER THE SE U.P. TRIED TO SHOW A
LITTLE MORE TIMING ON POPS FOR FRIDAY BUT CONFIDENCE WASN/T HIGH
ENOUGH TO SHOW DRY PERIODS UNDER THE DRY SLOT.
WITH THE MOISTURE WRAPPING AROUND THE UPPER LOW FRIDAY
NIGHT INTO SATURDAY NIGHT...EXPECT THERE TO BE PERIODS OF
CLOUDS...ESPECIALLY FRIDAY NIGHT INTO SATURDAY. MOST OF THE MOISTURE
IS FAIRLY SHALLOW...BUT THERE MAY BE ENOUGH AROUND FOR SOME LIGHT
RAIN SHOWERS/DRIZZLE ON FRIDAY NIGHT INTO SATURDAY AND WILL RETAIN
SLIGHT CHANCE POPS. TEMPERATURES THIS WEEKEND WILL VERY COOL FOR
LATE JULY STANDARDS...WITH LOW 60S ON SATURDAY (10-15 DEGREES BELOW
NORMAL) AND MID-UPPER 60S FOR SUNDAY.
THE UPPER LOW SHIFTS AWAY ON SUNDAY AFTERNOON AND THE AREA WILL BE
BACK UNDER WEST-NORTHWEST FLOW ALOFT. BOTH GFS/ECMWF ARE SHOWING A
SHORTWAVE AND ASSOCIATED WARM FRONT MOVING TOWARDS THE AREA
SOMETIME MONDAY TO TUESDAY AND HAVE SLOWLY BROUGHT POPS UP TO
CHANCES BY TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1203 AM EDT WED JUL 24 2013
HIGH PRES BUILDING INTO THE AREA...EXPECT VFR CONDITIONS TO DOMINATE
THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 307 AM EDT WED JUL 24 2013
THERE WILL BE LITTLE CHANGE PRESSURE WISE THROUGH THE WEEKEND...WITH
WINDS LESS THAN 20KTS /EXCLUDING NEAR THUNDERSTORMS/. HIGH PRESSURE
ACROSS THE UPPER GREAT LAKES WILL SLOWLY DRIFT ACROSS THE LOWER
GREAT LAKES TONIGHT...WHERE IT WILL LINGER THROUGH FRIDAY. IN THE
MEANTIME...LOW PRESSURE ACROSS SOUTHERN MANITOBA SHOULD PUSH ACROSS
INTO WESTERN LAKE SUPERIOR THURSDAY AFTERNOON BEFORE SLOWLY EXITING
EASTERN LAKE SUPERIOR FRIDAY AFTERNOON. EXPECT THE LOW TO DEEPEN
SLIGHTLY ACROSS EASTERN ONTARIO FROM LATE FRIDAY THROUGH THE
WEEKEND...LEAVING A TROUGH ACROSS LAKE SUPERIOR. HIGH PRESSURE WILL
ATTEMPT TO PUSH INTO FAR WESTERN LAKE SUPERIOR TOWARD THE END OF THE
WEEKEND AND INTO THE START OF THE NEXT WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1203 AM EDT WED JUL 24 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 411 PM EDT TUE JUL 23 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS SHORTWAVE OVER
JAMES BAY. PRES GRADIENT BTWN ITS ASSOCIATED SFC LOW E OF JAMES BAY
AND SFC HIGH PRES OVER NW MN/ERN DAKOTAS HAS RESULTED IN BREEZY N/NW
WINDS TODAY AND MUCH COOLER CONDITIONS COMPARED TO YESTERDAY. PER
WATER VAPOR IMAGERY...IN THE NW FLOW UPSTREAM...THERE ARE A COUPLE
OF SHORTWAVES EVIDENT...ONE OVER ERN MT/WRN ND AND ANOTHER OVER
CNTRL SASKATCHEWAN. THE NRN WAVE MAY BE A FACTOR IN THE WEATHER HERE
ON WED.
A QUIET...COOL NIGHT IS IN STORE TONIGHT AS SFC HIGH PRES SETTLES SE
INTO WI...BRINGING DIMINISHING WINDS FROM W TO E. WITH DECREASING
WINDS...CLEAR SKIES AND PRECIPITABLE WATER 50-70PCT OF NORMAL...
EXPECT A DECENT RADIATIONAL COOLING NIGHT...ESPECIALLY OVER W AND SW
UPPER MI AS WINDS SHOULD DIMINISH TO CALM IN THAT AREA...BEING
CLOSER TO SFC HIGH PRES CENTER. WILL CONTINUE TO SHOW LOWEST TEMPS
IN THAT AREA (40 TO THE LWR 40S). OTHERWISE...MIN TEMPS SHOULD BE IN
THE 40S IN THE INTERIOR TO MOSTLY AROUND 50F ALONG THE GREAT LAKES.
AFTER A QUIET NIGHT...ATTENTION ON WED SHIFTS TO POSSIBLE AFTN
CONVECTION. SUMMERTIME WNW/NW FLOW IS OFTEN A FAVORABLE PATTERN
FOR ISOLD/SCT AFTN CONVECTION AS EVEN THE MOST SUBTLE SHORTWAVES CAN
SPARK SOME PCPN. IF THERE WASN`T A SHORTWAVE PRESENT UPSTREAM...
WOULD HAVE DROPPED PCPN MENTION ON WED...BUT SINCE THERE IS AN
OBVIOUS WAVE CURRENTLY UPSTREAM IN CNTRL SASKATCHEWAN...IT LOOKS
LIKE THERE WILL PROBABLY BE SOME ISOLD AFTN CONVECTION AS THE WAVE
DROPS SE INTO THE AREA. WILL CONTINUE TO HIGHLIGHT SCHC POPS OVER
MAINLY THE INTERIOR W AND CNTRL WHERE THE LIMITED INSTABILITY IS
BEST. NAM/GFS MLCAPES ARE ONLY AS HIGH AS 200-300J/KG DURING THE MID
AFTN...SO THUNDER POTENTIAL APPEARS MINIMAL. HOWEVER...CANADIAN
RADARS CURRENTLY SHOW DECENT RETURNS IN THE VCNTY OF SHORTWAVE IN
SASKATCHEWAN AND SATELLITE IMAGERY SUGGESTS SOME DECENT
CONVECTION...SO THERE MAY BE SOME THUNDER OCCURRING WITH THE WAVE
THIS AFTN. FOR NOW...WILL LEAVE THUNDER MENTION IN THE FCST FOR WED
AND LET LATER SHIFTS REASSESS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 411 PM EDT TUE JUL 23 2013
MUCH OF THE LONG TERM PERIOD WILL BE INFLUENCED BY A SHORTWAVE
DROPPING SOUTH-SOUTHEAST THROUGH CENTRAL CANADA ON WEDNESDAY AND
WEDNESDAY NIGHT...WHICH THEN MOVES INTO CENTRAL ONTARIO BY THURSDAY
NIGHT AND CLOSES OFF. THIS UPPER LOW WILL REMAIN IN CENTRAL ONTARIO
INTO SUNDAY BEFORE SHIFTING NORTHEAST INTO ONTARIO FOR THE START OF
THE WORK WEEK.
WEDNESDAY NIGHT WILL BE RELATIVELY QUIET AS ANY DIURNAL CLOUDS AND
SHOWERS DIMINISH FAIRLY QUICKLY DURING THE EVENING. THEN...EXPECT
MID-HIGH CLOUDS TO BE ON THE INCREASE THROUGH THE NIGHT AS THE
SHORTWAVE MOVES INTO SOUTHWEST ONTARIO AND AN ASSOCIATED 1008MB LOW
DEVELOPS EAST OF LAKE WINNIPEG AND SLIDES EAST. AS THE SHORTWAVE
AND SURFACE LOW CONTINUE TO THE EAST-SOUTHEAST ON LATE WEDNESDAY
NIGHT AND THURSDAY...AN ASSOCIATED COLD FRONT WILL SLIDE INTO
WESTERN UPPER MICHIGAN DURING THE AFTERNOON. THAT WILL BE THE AREA
WITH THE BEST OPPORTUNITY FOR SHOWERS/THUNDERSTORMS ON THURSDAY
AFTERNOON AND WILL CONTINUE TO HIGHLIGHT INCREASING POPS TO LIKELY
VALUES DURING THE AFTERNOON.
INSTABILITY LOOKS FAIRLY LIMITED OVER MOST OF THE AREA...WITH MLCAPE
VALUES AROUND 500 J/KG ALTHOUGH MUCAPE VALUES DO APPROACH 1500
J/KG IN SOME MODELS OVER THE WEST AND 09Z SREF ONLY INDICATES A 20
PERCENT CHANCE 1000 J/KG IS REACHED. CAPE IS FAIRLY TALL/SKINNY AS
SEEN IN NCAPE VALUES IN THE 0.05-0.1 RANGE. AS FOR SHEAR...0-6KM AND
EFFECTIVE VALUES ARE ALSO MARGINAL (AROUND 30-35KTS)...ALTHOUGH
THERE IS SOME LOW LEVEL VEERING TO THE WIND. THE STRENGTH OF THE
SHORTWAVE MAY HELP OVERCOME THE MARGINAL INSTABILITY/SHEAR...BUT
THINK THE STORMS WILL PRIMARILY BE SUB SEVERE. THEY WILL LIKELY BE
THE STRONGEST OVER THE FAR WEST...WHERE IT IS CLOSER TO THE
SYNOPTIC AND FRONTAL FORCING. NAM/GFS STORM MOTION VECTORS INDICATE
THE STORMS WILL MOVE FAIRLY QUICKLY TO THE EAST (AROUND 40KTS) AND
HAVE FOLLOWED SUIT WITH THE POPS. BUT THE OVERALL TREND WITH THE
FRONT HAS BEEN SLOWER...WITH IT NOW EXITING EASTERN UPPER MICHIGAN
BETWEEN 09Z-18Z FRIDAY.
MODELS DIFFER SOMEWHAT WITH THE POSITION OF THE SURFACE/UPPER
LOW...BUT THE GENERAL IDEA OF COOL...CYCLONIC FLOW AFFECTING THE
UPPER GREAT LAKES FRIDAY THROUGH SUNDAY MORNING SEEMS REASONABLE.
ANOTHER SHORTWAVE ROTATES AROUND THE UPPER LOW ON FRIDAY AND
PRECIPITATION CHANCES DEPEND ON HOW QUICKLY THE FRONT MOVES
EAST...THE DRY SLOT BEHIND IT...AND ADDITIONAL MOISTURE DROPPING
SOUTHEAST ACROSS WESTERN LAKE SUPERIOR. THESE FEATURES ARE STILL
VARIABLE IN THE MODELS...BUT THE MORNING LOOKS TO HAVE THE BEST
OPPORTUNITY FOR LINGERING SHOWERS OVER THE SE U.P. TRIED TO SHOW A
LITTLE MORE TIMING ON POPS FOR FRIDAY BUT CONFIDENCE WASN/T HIGH
ENOUGH TO SHOW DRY PERIODS UNDER THE DRY SLOT.
WITH THE MOISTURE WRAPPING AROUND THE UPPER LOW FRIDAY
NIGHT INTO SATURDAY NIGHT...EXPECT THERE TO BE PERIODS OF
CLOUDS...ESPECIALLY FRIDAY NIGHT INTO SATURDAY. MOST OF THE MOISTURE
IS FAIRLY SHALLOW...BUT THERE MAY BE ENOUGH AROUND FOR SOME LIGHT
RAIN SHOWERS/DRIZZLE ON FRIDAY NIGHT INTO SATURDAY AND WILL RETAIN
SLIGHT CHANCE POPS. TEMPERATURES THIS WEEKEND WILL VERY COOL FOR
LATE JULY STANDARDS...WITH LOW 60S ON SATURDAY (10-15 DEGREES BELOW
NORMAL) AND MID-UPPER 60S FOR SUNDAY.
THE UPPER LOW SHIFTS AWAY ON SUNDAY AFTERNOON AND THE AREA WILL BE
BACK UNDER WEST-NORTHWEST FLOW ALOFT. BOTH GFS/ECMWF ARE SHOWING A
SHORTWAVE AND ASSOCIATED WARM FRONT MOVING TOWARDS THE AREA
SOMETIME MONDAY TO TUESDAY AND HAVE SLOWLY BROUGHT POPS UP TO
CHANCES BY TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1203 AM EDT WED JUL 24 2013
HIGH PRES BUILDING INTO THE AREA...EXPECT VFR CONDITIONS TO DOMINATE
THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT TUE JUL 23 2013
AFTER A PERIOD OF STRONG WINDS TODAY ACROSS LAKE SUPERIOR IN THE
WAKE OF A COLD FRONT...LIGHTER WINDS UNDER 20KT WILL BE THE RULE
TONIGHT INTO WED AS HIGH PRES BUILDS INTO THE WRN GREAT LAKES. AS
THE HIGH SHIFTS E AND LOW PRES APPROACHES FROM THE NW...WINDS WILL
BECOME SOUTHERLY WED NIGHT/THU...BUT REMAIN UNDER 20KT. EVEN AFTER
THE LOW PASSES THRU THE UPPER GREAT LAKES/NRN ONTARIO...WINDS WILL
PROBABLY REMAIN 20KT OR LESS LATE WEEK AND THRU THE WEEKEND.
HOWEVER...WILL NEED TO WATCH FOR STRONGER SOUTHERLY WINDS THU NIGHT
JUST AHEAD OF THE LOW AND ASSOCIATED COLD FRONT AND THEN LATER FRI
INTO SAT BEHIND COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1218 PM CDT WED JUL 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 259 AM CDT WED JUL 24 2013
SPRAWLING COOL AND DRY CANADIAN HIGH IN PLACE AT THE SFC TO START
OFF THE DAY. UPSTAIRS THOUGH...A WAVY NW FLOW HAS KEPT A STEADY
DIET OF MID CLOUDS STREAMING ACROSS THE AREA OVERNIGHT...WHICH HAS
KEPT TEMPS FROM FALLING OFF AS MUCH THEY COULD...ESPECIALLY OVER
MN. FOR THE REST OF THE SHORT TERM...WE WILL SEE HEIGHTS BUILD
SOME TODAY OUT AHEAD OF A STRONG SHORTWAVE MOVING THROUGH THE
CANADIAN PRAIRIES TOWARD NRN MN BY THE END OF THE PERIOD. AT THE
SFC...THE HIGH WILL SLIP INTO THE GREAT LAKES WHILE A COLD FRONT
SLIPS ACROSS NODAK AND INTO NW MN BY THURSDAY MORNING.
BIG QUESTION FOR TODAY WAS TO OR NOT TO INCLUDE SOME ISO THUNDER
IN THE FORECAST. IF YOU HEAD OFF IN SEARCH OF YOUR FAVORITE
CAM...YOU LIKELY HAVE SEEN THAT MOST GENERATE SOME ISOLATED
CONVECTION BY THE AFTERNOON SOMEWHERE NEAR THE I-35 CORRIDOR...BUT
AFTER TAKING A PEAK AT SOME DETERMINISTIC GUIDANCE TO SUPPORT THE
ISO STORMS...DECIDED AGAINST INCLUDING ANYTHING THROUGH THE
AFTERNOON IN THE GRIDS. THERE WERE TWO THINGS THAT PUSHED ME
TOWARD A DRY FORECAST FOR TODAY. FIRST...THE RAP CONTINUES TO SHOW
NO MUCAPE ACROSS THE MPX AREA THIS AFTERNOON...WITH BEST LI/S
REMAINING ABOVE ZERO...NOT EXACTLY WHAT YOU WANT TO SEE FOR
THUNDERSTORMS. SECOND...EVEN THOUGH THE NAM GENERATES 500-1000
J/KG OF MLCAPE BY THE AFTERNOON...A QUICK LOOK AT SOUNDINGS ACROSS
THE AREA SHOWS THAT IT IS A VERY SKINNY CAPE PROFILE AND ONE THAT
DOES NOT LOOK PROMISING FOR GENERATING DEEP MOIST CONVECTION. SO
AFTER MUCH DEBATE...DECIDED TO JOIN THE GEM AND ECMWF IN GOING DRY
FOR TODAY.
THIS EVENING/TONIGHT...PRECIP CHANCES DO LOOK AT LEAST MARGINALLY
BETTER. THE REASON IS THAT AS THE STRONG SHORTWAVE DROPS SOUTH
OUT OF CANADA...WE WILL SEE H85 WINDS...MOISTURE TRANSPORT AND WAA
SLOWLY INCREASING DURING THE NIGHT. THOUGH NOT IMPRESSIVE BY ANY
MEANS...USUALLY A PRETTY RISKY PROPOSITION TO NOT INCLUDE SOME
POPS FOR A NIGHT TIME PERIOD IN THE SUMMER THAT FEATURES AT LEAST
WEAK WAA AND MOISTURE TRANSPORT AT THE H85 LEVEL. MOST LIKELY
SCENARIO AT THE MOMENT LOOKS TO BE REMNANTS OF CONVECTION THAT
DEVELOPS IN NRN MN THIS AFTERNOON DROPPING SE INTO EC MN AND WRN
WI OVERNIGHT. FOR NOW HAVE CHANCE POPS ROUGHLY ALONG AND NORTH OF
I-94...THOUGH DO NOT HAVE MUCH CONFIDENCE IN HOW STORMS TONIGHT
WILL PLAY OUT AT THE MOMENT.
FOR TEMPERATURES...925-850 TEMPS INCREASE TO BETWEEN 16C AND 20C OUT
IN WRN MN THIS AFTERNOON...WHICH WILL SUPPORT TEMPERATURES WARMING
INTO THE LOW-MID 80S IF CLOUD COVER DOES NOT SLOW THINGS DOWN TOO
MUCH. AS A RESULT...DID NUDGE HIGHS UP A COUPLE OF DEGREES OUT
WEST...BUT WILL HAVE TO SEE HOW CLOUDS PLAY OUT. TONIGHT...WEAK SRLY
FLOW AND WAA SHOULD KEEP TEMPS SIMILAR TO WHAT WE ARE SEEING UNDER
THE CLOUDS IN MN TONIGHT...AND ABOUT 5 DEGS WARMER THAN WHAT WE ARE
SEEING OVER IN WI RIGHT NOW.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 259 AM CDT WED JUL 24 2013
MAIN ISSUE IN THE LONG TERM IS THUNDERSTORMS AND POTENTIAL FOR
SEVERE WX THU AFTN AND EVE...THEN THE MUCH COOLER TEMPERATURES
EXPECTED FOR THE WEEKEND.
AN UPPER LEVEL LOW CENTER WILL DROP OUT OF MANITOBA THU MRNG SWWD
ON ITS WAY INTO THE GRT LAKES. AT THE SFC...A POTENT CDFNT WILL BE
LINKED BY TWO ANCHOR LOW PRES CENTERS...ONCE JUST N OF KINL AND
THE OTHER OVER SW SD BY MIDDAY WED. THESE TWO SFC LOW PRES CENTERS
WILL PHASE TOGETHER OVER THE GRT LAKES BY MIDDAY FRI...SHOVING THE
CDFNT THRU THE REGION FRI MRNG WHILE THE UPPER LEVEL LOW DEEPENS
INTO A POTENT COMPACT LONGWAVE TROUGH OVER THE UPPER MISSISSIPPI
RIVER VALLEY. EFFICIENT WARM SECTORING AHEAD OF THE CDFNT WILL
DRAG WARM AND MORE MOIST AIR FROM THE DEEP S UP INTO THE REGION
FOR MID-TO-LATE THU. STRONG JETTING IN THE MID- AND UPPER-LEVELS
WILL ENHANCE TSTM DEVELOPMENT DURG THE DAY ON THU. OF NOTE HOWEVER
IS COLD AIR ALOFT...A FUNCTION OF THE UPPER LOW DROPPING S. THIS
WILL ALLOW GROWING STORMS TO HIT THE FREEZING LEVEL QUICKLY...
WORKING WITH STEEP LAPSE RATES TO MAKE LARGE HAIL A SEVERE WX
HAZARD. IN ADDITION...HELICITIES INCRS SIGNIFICANTLY INVOF THE FNT
WITH SWLY WINDS AT THE SFC AND NW FLOW ALOFT DUE TO LOCATION OF
THE UPPER LOW. ISOLD TORNADOES...PARTICULARLY OVER SRN MN...ARE
ANOTHER POTENTIAL SEVERE WX HAZARD. THE SPC HAS ADDED A SLGT RISK
FOR SRN-ERN MN INTO WRN WI IN THE MORNING SWODY2 AND THIS IS WELL
WARRANTED.
THE CDFNT WILL SHIFT WELL INTO THE GRT LAKES BY FRI EVE...ALLOWING
DEEP N-NW FLOW CAA TO COMMENCE. THE UPPER LOW WILL THE SIT-AND-
SPIN OVER THE GRT LAKES THRU SUN...KEEPING TEMPERATURES 10-12
DEGREES BELOW NORMAL FRO THRU THE WEEKEND. H85 TEMPS DROP TO
ABOUT 6-8 DEG C...WHICH WILL TRANSLATE TO LOWS ARND 50 AND HIGHS
ARND 70 FRI THRU SUN. THE DENSE SFC HIGH PRES ASSOCIATED WITH THIS
COOLDOWN WILL SHIFT TO THE E DURING THE EARLY PORTION OF NEXT
WEEK...ALLOWING FOR A WARMER RETURN FLOW ON THE BACKSIDE OF THE
HIGH. TEMPS WILL RISE BACK CLOSER TO NORMAL LEVELS WHILE SEVERAL
SHORTWAVE DISTURBANCES RIDE WITHIN THE FLOW BETWEEN A RIDGE OVER
THE PLAINS AND A TROUGH OVER THE APPALACHIANS. THESE DISTURBANCES
MAY BE ABLE TO SQUEEZE ENOUGH LIMITED MOISTURE TO PRODUCE ISOLD TO
SCATTERED SHOWERS AND TSTMS MON-TUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1205 PM CDT WED JUL 24 2013
WEAK SFC TROUGH ACROSS EC MN THIS AFTN AND THE ADDED DAYTIME
HEATING WEST OF THE PERSISTENT LOWER CLOUD DECK THIS
MORNING...WILL LEAD TO SOME INSTABILITY SHRA ACROSS EC MN. LACK OF
SUFFICIENT LIFT AND ONLY MODEST INSTABILITY...VCSH IS THE BEST
SCENARIO. OTHERWISE...VFR CONDS WILL CONTINUE THRU THIS
AFTN/EVENING...WITH A SMALL CHC OF -SHRA/TSRA AFT MIDNIGHT ACROSS
EC MN/WC WI WHERE BETTER MOISTURE ADVECTION AND LIFT WILL RESIDE.
WINDS WILL BE GENERALLY FROM THE W/NW ACROSS THE WESTERN
CWA...WITH A LIGHT SW/W WIND IN THE EASTERN HALF. TIMING OF THE
SHRA/TSRA TOMORROW WILL BE DETERMINED BY AFTN SFC HEATING AND
WHERE THE COLD FRONT LIES ONCE THE CAP BREAKS.
KMSP...
AFTN INSTABILITY SHRA ARE POSSIBLE...BUT CIGS WILL REMAIN AOA 5K.
WINDS WILL BE GENERALLY FROM THE WSW BLW 7 KTS THRU 00Z...WITH A
LIGHT AND VARIABLE WIND...BECOMING SW THURSDAY MORNING. FRONTAL
PASSAGE WILL BE SOMETIME BETWEEN 18-22Z/25. SHRA/TSRA WILL LIKELY
BE ALONG AND BEHIND THIS FRONT...SO HAVE INTRODUCED PROB30 TSRA
BETWEEN 20-24Z.
/OUTLOOK FOR KMSP/
THU...LINGERING SHRA/TSRA THURSDAY EVENING. MVFR OR LOWER CONDS
POSSIBLE IN TSRA. WINDS SW 5-10 KT...BECOMING NW 10 KTS.
FRI...VFR. WINDS NW 10G20 KT. -SHRA IN THE AFTN.
SAT...VFR. WINDS NW 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
547 AM CDT WED JUL 24 2013
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 259 AM CDT WED JUL 24 2013
SPRAWLING COOL AND DRY CANADIAN HIGH IN PLACE AT THE SFC TO START
OFF THE DAY. UPSTAIRS THOUGH...A WAVY NW FLOW HAS KEPT A STEADY
DIET OF MID CLOUDS STREAMING ACROSS THE AREA OVERNIGHT...WHICH HAS
KEPT TEMPS FROM FALLING OFF AS MUCH THEY COULD...ESPECIALLY OVER
MN. FOR THE REST OF THE SHORT TERM...WE WILL SEE HEIGHTS BUILD
SOME TODAY OUT AHEAD OF A STRONG SHORTWAVE MOVING THROUGH THE
CANADIAN PRAIRIES TOWARD NRN MN BY THE END OF THE PERIOD. AT THE
SFC...THE HIGH WILL SLIP INTO THE GREAT LAKES WHILE A COLD FRONT
SLIPS ACROSS NODAK AND INTO NW MN BY THURSDAY MORNING.
BIG QUESTION FOR TODAY WAS TO OR NOT TO INCLUDE SOME ISO THUNDER
IN THE FORECAST. IF YOU HEAD OFF IN SEARCH OF YOUR FAVORITE
CAM...YOU LIKELY HAVE SEEN THAT MOST GENERATE SOME ISOLATED
CONVECTION BY THE AFTERNOON SOMEWHERE NEAR THE I-35 CORRIDOR...BUT
AFTER TAKING A PEAK AT SOME DETERMINISTIC GUIDANCE TO SUPPORT THE
ISO STORMS...DECIDED AGAINST INCLUDING ANYTHING THROUGH THE
AFTERNOON IN THE GRIDS. THERE WERE TWO THINGS THAT PUSHED ME
TOWARD A DRY FORECAST FOR TODAY. FIRST...THE RAP CONTINUES TO SHOW
NO MUCAPE ACROSS THE MPX AREA THIS AFTERNOON...WITH BEST LI/S
REMAINING ABOVE ZERO...NOT EXACTLY WHAT YOU WANT TO SEE FOR
THUNDERSTORMS. SECOND...EVEN THOUGH THE NAM GENERATES 500-1000
J/KG OF MLCAPE BY THE AFTERNOON...A QUICK LOOK AT SOUNDINGS ACROSS
THE AREA SHOWS THAT IT IS A VERY SKINNY CAPE PROFILE AND ONE THAT
DOES NOT LOOK PROMISING FOR GENERATING DEEP MOIST CONVECTION. SO
AFTER MUCH DEBATE...DECIDED TO JOIN THE GEM AND ECMWF IN GOING DRY
FOR TODAY.
THIS EVENING/TONIGHT...PRECIP CHANCES DO LOOK AT LEAST MARGINALLY
BETTER. THE REASON IS THAT AS THE STRONG SHORTWAVE DROPS SOUTH
OUT OF CANADA...WE WILL SEE H85 WINDS...MOISTURE TRANSPORT AND WAA
SLOWLY INCREASING DURING THE NIGHT. THOUGH NOT IMPRESSIVE BY ANY
MEANS...USUALLY A PRETTY RISKY PROPOSITION TO NOT INCLUDE SOME
POPS FOR A NIGHT TIME PERIOD IN THE SUMMER THAT FEATURES AT LEAST
WEAK WAA AND MOISTURE TRANSPORT AT THE H85 LEVEL. MOST LIKELY
SCENARIO AT THE MOMENT LOOKS TO BE REMNANTS OF CONVECTION THAT
DEVELOPS IN NRN MN THIS AFTERNOON DROPPING SE INTO EC MN AND WRN
WI OVERNIGHT. FOR NOW HAVE CHANCE POPS ROUGHLY ALONG AND NORTH OF
I-94...THOUGH DO NOT HAVE MUCH CONFIDENCE IN HOW STORMS TONIGHT
WILL PLAY OUT AT THE MOMENT.
FOR TEMPERATURES...925-850 TEMPS INCREASE TO BETWEEN 16C AND 20C OUT
IN WRN MN THIS AFTERNOON...WHICH WILL SUPPORT TEMPERATURES WARMING
INTO THE LOW-MID 80S IF CLOUD COVER DOES NOT SLOW THINGS DOWN TOO
MUCH. AS A RESULT...DID NUDGE HIGHS UP A COUPLE OF DEGREES OUT
WEST...BUT WILL HAVE TO SEE HOW CLOUDS PLAY OUT. TONIGHT...WEAK SRLY
FLOW AND WAA SHOULD KEEP TEMPS SIMILAR TO WHAT WE ARE SEEING UNDER
THE CLOUDS IN MN TONIGHT...AND ABOUT 5 DEGS WARMER THAN WHAT WE ARE
SEEING OVER IN WI RIGHT NOW.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 259 AM CDT WED JUL 24 2013
MAIN ISSUE IN THE LONG TERM IS THUNDERSTORMS AND POTENTIAL FOR
SEVERE WX THU AFTN AND EVE...THEN THE MUCH COOLER TEMPERATURES
EXPECTED FOR THE WEEKEND.
AN UPPER LEVEL LOW CENTER WILL DROP OUT OF MANITOBA THU MRNG SWWD
ON ITS WAY INTO THE GRT LAKES. AT THE SFC...A POTENT CDFNT WILL BE
LINKED BY TWO ANCHOR LOW PRES CENTERS...ONCE JUST N OF KINL AND
THE OTHER OVER SW SD BY MIDDAY WED. THESE TWO SFC LOW PRES CENTERS
WILL PHASE TOGETHER OVER THE GRT LAKES BY MIDDAY FRI...SHOVING THE
CDFNT THRU THE REGION FRI MRNG WHILE THE UPPER LEVEL LOW DEEPENS
INTO A POTENT COMPACT LONGWAVE TROUGH OVER THE UPPER MISSISSIPPI
RIVER VALLEY. EFFICIENT WARM SECTORING AHEAD OF THE CDFNT WILL
DRAG WARM AND MORE MOIST AIR FROM THE DEEP S UP INTO THE REGION
FOR MID-TO-LATE THU. STRONG JETTING IN THE MID- AND UPPER-LEVELS
WILL ENHANCE TSTM DEVELOPMENT DURG THE DAY ON THU. OF NOTE HOWEVER
IS COLD AIR ALOFT...A FUNCTION OF THE UPPER LOW DROPPING S. THIS
WILL ALLOW GROWING STORMS TO HIT THE FREEZING LEVEL QUICKLY...
WORKING WITH STEEP LAPSE RATES TO MAKE LARGE HAIL A SEVERE WX
HAZARD. IN ADDITION...HELICITIES INCRS SIGNIFICANTLY INVOF THE FNT
WITH SWLY WINDS AT THE SFC AND NW FLOW ALOFT DUE TO LOCATION OF
THE UPPER LOW. ISOLD TORNADOES...PARTICULARLY OVER SRN MN...ARE
ANOTHER POTENTIAL SEVERE WX HAZARD. THE SPC HAS ADDED A SLGT RISK
FOR SRN-ERN MN INTO WRN WI IN THE MORNING SWODY2 AND THIS IS WELL
WARRANTED.
THE CDFNT WILL SHIFT WELL INTO THE GRT LAKES BY FRI EVE...ALLOWING
DEEP N-NW FLOW CAA TO COMMENCE. THE UPPER LOW WILL THE SIT-AND-
SPIN OVER THE GRT LAKES THRU SUN...KEEPING TEMPERATURES 10-12
DEGREES BELOW NORMAL FRO THRU THE WEEKEND. H85 TEMPS DROP TO
ABOUT 6-8 DEG C...WHICH WILL TRANSLATE TO LOWS ARND 50 AND HIGHS
ARND 70 FRI THRU SUN. THE DENSE SFC HIGH PRES ASSOCIATED WITH THIS
COOLDOWN WILL SHIFT TO THE E DURING THE EARLY PORTION OF NEXT
WEEK...ALLOWING FOR A WARMER RETURN FLOW ON THE BACKSIDE OF THE
HIGH. TEMPS WILL RISE BACK CLOSER TO NORMAL LEVELS WHILE SEVERAL
SHORTWAVE DISTURBANCES RIDE WITHIN THE FLOW BETWEEN A RIDGE OVER
THE PLAINS AND A TROUGH OVER THE APPALACHIANS. THESE DISTURBANCES
MAY BE ABLE TO SQUEEZE ENOUGH LIMITED MOISTURE TO PRODUCE ISOLD TO
SCATTERED SHOWERS AND TSTMS MON-TUE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 529 AM CDT WED JUL 24 2013
SHORTWAVE MOVING ACROSS MN OUT THE GATE PRODUCING FAIRLY EXTENSIVE
CLOUD COVER...WITH NOTHING MORE THAN A COUPLE OF SPRINKLES
EXPECTED FROM IT. STRONGER WAVE BACK NEAR BISMARK WILL BE OVER MN BY
18Z...AND THIS APPEARS TO BE WHAT THE HRRR IS KEYING ON FOR SCT
CONVECTION ALONG I-35 THIS AFTERNOON. COVERAGE LOOKS SPARSE...AND
CONFIDENCE IN ANYTHING OCCURRING IS NOT ALL THAT GREAT GIVEN
REASONING IN SHORT TERM DISCUSSION. LATE TONIGHT...THERE IS THE
POTENTIAL FOR SCATTERED THUNDERSTORMS FROM CENTRAL MN SOUTHEAST
INTO WESTERN WI. TIMING WOULD BE 6-9Z FOR ERN MN AND 9-12Z FOR WRN
WI. AGAIN COVERAGE LOOKS SPARSE AND CONFIDENCE TOO LOW TO INCLUDE
IN TAFS. WITH HIGH PRESSURE SLOWLY SLIDING TO MICH...WINDS WILL BE
LIGHT TO DAY AND GRADUALLY TAKING ON MORE OF A WRN COMPONENT.
KMSP...THERE WILL BE A SMALL THREAT FOR A SHRA/TSRA BETEWEEN 18Z
AND 21Z...AND AGAIN FROM 6-9Z. CONFIDENCE AND EXPECTED COVERAGE
THOUGH ARE TOO LOW TO INCLUDE IN TAF AT THIS POINT. WINDS THIS
PERIOD LOOK TO REMAIN 7 KTS OR LESS...SO SHOULD ALLOW FOR SOME
LEEWAY WITH RUNWAY SELECTION.
/OUTLOOK FOR KMSP/
THU...AFTERNOON TSRA LIKELY. MVFR OR LOWER CONDS POSSIBLE IN TSRA.
WINDS SW 5-10 KT.
FRI...VFR. WINDS NW 10G20 KT.
SAT...VFR. WINDS NW 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
418 AM CDT WED JUL 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 259 AM CDT WED JUL 24 2013
SPRAWLING COOL AND DRY CANADIAN HIGH IN PLACE AT THE SFC TO START
OFF THE DAY. UPSTAIRS THOUGH...A WAVY NW FLOW HAS KEPT A STEADY
DIET OF MID CLOUDS STREAMING ACROSS THE AREA OVERNIGHT...WHICH HAS
KEPT TEMPS FROM FALLING OFF AS MUCH THEY COULD...ESPECIALLY OVER
MN. FOR THE REST OF THE SHORT TERM...WE WILL SEE HEIGHTS BUILD
SOME TODAY OUT AHEAD OF A STRONG SHORTWAVE MOVING THROUGH THE
CANADIAN PRAIRIES TOWARD NRN MN BY THE END OF THE PERIOD. AT THE
SFC...THE HIGH WILL SLIP INTO THE GREAT LAKES WHILE A COLD FRONT
SLIPS ACROSS NODAK AND INTO NW MN BY THURSDAY MORNING.
BIG QUESTION FOR TODAY WAS TO OR NOT TO INCLUDE SOME ISO THUNDER
IN THE FORECAST. IF YOU HEAD OFF IN SEARCH OF YOUR FAVORITE
CAM...YOU LIKELY HAVE SEEN THAT MOST GENERATE SOME ISOLATED
CONVECTION BY THE AFTERNOON SOMEWHERE NEAR THE I-35 CORRIDOR...BUT
AFTER TAKING A PEAK AT SOME DETERMINISTIC GUIDANCE TO SUPPORT THE
ISO STORMS...DECIDED AGAINST INCLUDING ANYTHING THROUGH THE
AFTERNOON IN THE GRIDS. THERE WERE TWO THINGS THAT PUSHED ME
TOWARD A DRY FORECAST FOR TODAY. FIRST...THE RAP CONTINUES TO SHOW
NO MUCAPE ACROSS THE MPX AREA THIS AFTERNOON...WITH BEST LI/S
REMAINING ABOVE ZERO...NOT EXACTLY WHAT YOU WANT TO SEE FOR
THUNDERSTORMS. SECOND...EVEN THOUGH THE NAM GENERATES 500-1000
J/KG OF MLCAPE BY THE AFTERNOON...A QUICK LOOK AT SOUNDINGS ACROSS
THE AREA SHOWS THAT IT IS A VERY SKINNY CAPE PROFILE AND ONE THAT
DOES NOT LOOK PROMISING FOR GENERATING DEEP MOIST CONVECTION. SO
AFTER MUCH DEBATE...DECIDED TO JOIN THE GEM AND ECMWF IN GOING DRY
FOR TODAY.
THIS EVENING/TONIGHT...PRECIP CHANCES DO LOOK AT LEAST MARGINALLY
BETTER. THE REASON IS THAT AS THE STRONG SHORTWAVE DROPS SOUTH
OUT OF CANADA...WE WILL SEE H85 WINDS...MOISTURE TRANSPORT AND WAA
SLOWLY INCREASING DURING THE NIGHT. THOUGH NOT IMPRESSIVE BY ANY
MEANS...USUALLY A PRETTY RISKY PROPOSITION TO NOT INCLUDE SOME
POPS FOR A NIGHT TIME PERIOD IN THE SUMMER THAT FEATURES AT LEAST
WEAK WAA AND MOISTURE TRANSPORT AT THE H85 LEVEL. MOST LIKELY
SCENARIO AT THE MOMENT LOOKS TO BE REMNANTS OF CONVECTION THAT
DEVELOPS IN NRN MN THIS AFTERNOON DROPPING SE INTO EC MN AND WRN
WI OVERNIGHT. FOR NOW HAVE CHANCE POPS ROUGHLY ALONG AND NORTH OF
I-94...THOUGH DO NOT HAVE MUCH CONFIDENCE IN HOW STORMS TONIGHT
WILL PLAY OUT AT THE MOMENT.
FOR TEMPERATURES...925-850 TEMPS INCREASE TO BETWEEN 16C AND 20C OUT
IN WRN MN THIS AFTERNOON...WHICH WILL SUPPORT TEMPERATURES WARMING
INTO THE LOW-MID 80S IF CLOUD COVER DOES NOT SLOW THINGS DOWN TOO
MUCH. AS A RESULT...DID NUDGE HIGHS UP A COUPLE OF DEGREES OUT
WEST...BUT WILL HAVE TO SEE HOW CLOUDS PLAY OUT. TONIGHT...WEAK SRLY
FLOW AND WAA SHOULD KEEP TEMPS SIMILAR TO WHAT WE ARE SEEING UNDER
THE CLOUDS IN MN TONIGHT...AND ABOUT 5 DEGS WARMER THAN WHAT WE ARE
SEEING OVER IN WI RIGHT NOW.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 259 AM CDT WED JUL 24 2013
MAIN ISSUE IN THE LONG TERM IS THUNDERSTORMS AND POTENTIAL FOR
SEVERE WX THU AFTN AND EVE...THEN THE MUCH COOLER TEMPERATURES
EXPECTED FOR THE WEEKEND.
AN UPPER LEVEL LOW CENTER WILL DROP OUT OF MANITOBA THU MRNG SWWD
ON ITS WAY INTO THE GRT LAKES. AT THE SFC...A POTENT CDFNT WILL BE
LINKED BY TWO ANCHOR LOW PRES CENTERS...ONCE JUST N OF KINL AND
THE OTHER OVER SW SD BY MIDDAY WED. THESE TWO SFC LOW PRES CENTERS
WILL PHASE TOGETHER OVER THE GRT LAKES BY MIDDAY FRI...SHOVING THE
CDFNT THRU THE REGION FRI MRNG WHILE THE UPPER LEVEL LOW DEEPENS
INTO A POTENT COMPACT LONGWAVE TROUGH OVER THE UPPER MISSISSIPPI
RIVER VALLEY. EFFICIENT WARM SECTORING AHEAD OF THE CDFNT WILL
DRAG WARM AND MORE MOIST AIR FROM THE DEEP S UP INTO THE REGION
FOR MID-TO-LATE THU. STRONG JETTING IN THE MID- AND UPPER-LEVELS
WILL ENHANCE TSTM DEVELOPMENT DURG THE DAY ON THU. OF NOTE HOWEVER
IS COLD AIR ALOFT...A FUNCTION OF THE UPPER LOW DROPPING S. THIS
WILL ALLOW GROWING STORMS TO HIT THE FREEZING LEVEL QUICKLY...
WORKING WITH STEEP LAPSE RATES TO MAKE LARGE HAIL A SEVERE WX
HAZARD. IN ADDITION...HELICITIES INCRS SIGNIFICANTLY INVOF THE FNT
WITH SWLY WINDS AT THE SFC AND NW FLOW ALOFT DUE TO LOCATION OF
THE UPPER LOW. ISOLD TORNADOES...PARTICULARLY OVER SRN MN...ARE
ANOTHER POTENTIAL SEVERE WX HAZARD. THE SPC HAS ADDED A SLGT RISK
FOR SRN-ERN MN INTO WRN WI IN THE MORNING SWODY2 AND THIS IS WELL
WARRANTED.
THE CDFNT WILL SHIFT WELL INTO THE GRT LAKES BY FRI EVE...ALLOWING
DEEP N-NW FLOW CAA TO COMMENCE. THE UPPER LOW WILL THE SIT-AND-
SPIN OVER THE GRT LAKES THRU SUN...KEEPING TEMPERATURES 10-12
DEGREES BELOW NORMAL FRO THRU THE WEEKEND. H85 TEMPS DROP TO
ABOUT 6-8 DEG C...WHICH WILL TRANSLATE TO LOWS ARND 50 AND HIGHS
ARND 70 FRI THRU SUN. THE DENSE SFC HIGH PRES ASSOCIATED WITH THIS
COOLDOWN WILL SHIFT TO THE E DURING THE EARLY PORTION OF NEXT
WEEK...ALLOWING FOR A WARMER RETURN FLOW ON THE BACKSIDE OF THE
HIGH. TEMPS WILL RISE BACK CLOSER TO NORMAL LEVELS WHILE SEVERAL
SHORTWAVE DISTURBANCES RIDE WITHIN THE FLOW BETWEEN A RIDGE OVER
THE PLAINS AND A TROUGH OVER THE APPALACHIANS. THESE DISTURBANCES
MAY BE ABLE TO SQUEEZE ENOUGH LIMITED MOISTURE TO PRODUCE ISOLD TO
SCATTERED SHOWERS AND TSTMS MON-TUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM CDT TUE JUL 23 2013
ONLY AVIATION CONCERN IS WHETHER A WEAKENING DISTURBANCE ACROSS
SERN ND LATE THIS EVENING CAN GENERATE ISOLD TSRA/SHRA ACROSS
WESTERN MN TOWARD DAYBREAK. RWF WOULD BE ON THE EASTERN FRINGES
OF THIS ACTIVITY. ELSEWHERE...VFR CONDS WILL CONTINUE WITH CALM
WINDS TONIGHT BECOMING W/SW AFT 14Z.
KMSP...VFR CONDITIONS EXPECTED WITH LGT/VAR WINDS BECOMING
SOUTHWESTERLY WEDNESDAY MORNING.
/OUTLOOK FOR KMSP/
THU...CHC SHRA/TSRA. VFR OUTSIDE OF SHRA/TSRA. WINDS SW 5-10 KT.
FRI...VFR. WINDS NW 10 KT.
SAT...VFR. WINDS NW 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JPC
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1100 AM CDT WED JUL 24 2013
.UPDATE...
UPPER S/WV CONTINUE TO MOVE INTO THE REGION IN THE NW FLOW ALOFT AND
THESE WILL ENHANCE THE POTENTIAL FOR SHOWERS/THUNDERSTORMS THIS
AFTERNOON. AN MCV IS VERY EVIDENT IN VISIBLE SATELLITE/REGIONAL
RADAR IMAGERY MOVING INTO E/SE MS. IN THE WAKE OF THE DEPARTING
MCV...SUBSIDENCE HAS HELPED CLEAR SOME OF THE CLOUD COVER OVER THE
REGION. DUE TO TO THIS...WENT CLOSE TO MAV NUMBERS BUT SEEMED TOO
WARM IN THE W/NW AND DROPPED A FEW DEGREES. TEMPS WILL BE IN THE LOW
90S THIS AFTERNOON. DUE TO LESS CLOUD COVER FOR A FEW HOURS AND SOME
HEATING...MAY BE ABLE TO GET SOME DECENT INSTABILITY THIS AFTERNOON.
OVERALL REGIONAL SOUNDINGS INDICATE SOME DRY LOW LEVEL AIR AND
MEAGER LAPSE RATES WITH VERTICAL TOTALS AROUND 25-26C. SOME STRONG
STORMS ARE POSSIBLE THIS AFTERNOON. HI-RES MODELS INDICATE THAT
CONVECTION WILL DEVELOP IN ANOTHER APPROACHING S/WV IN S/SE AR AND
WILL MOVE SE...MAINLY AFTER 17Z. SOME STORM ACTIVITY COULD DEVELOP
FROM THE PASSING FRONT JUST NORTH OF THE REGION IN CENTRAL/N TN.
HRRR IS INDICATING MORE COVERAGE OF ACTIVITY FROM A LINE ALONG FROM
GREENVILLE TO HATTIESBURG AND HI-RES WRF ALSO INDICATES A SIMILAR
IDEA. WENT CLOSE TO MAV POPS BUT ADJUSTED SLIGHTLY. TEMPS/DEWPOINTS
WERE ADJUSTED ACCORDING TO CURRENT TRENDS AND SKY COVER GRIDS WERE
ADJUSTED SLIGHTLY. REST OF THE FORECAST IS ON TRACK. /DC/
&&
.AVIATION...MORNING IFR TO MVFR CEILINGS SLOWLY LIFTING TO VFR AND
THIS WILL PREVAIL THROUGH THE AFTERNOON. ANOTHER ROUND OF SHRA/TSRA
POSSIBLE TO IMPACT MOST AREAS AFTER 17Z TODAY. SFC WINDS WILL BE
GENERALLY OUT OF THE WEST AND MAY OCCASIONALLY GUST THIS AFTERNOON
ESPECIALLY WITH STORMS. TSRA SHOULD DIMINISH THIS EVENING WITH QUIET
WEATHER EXPECTED OVERNIGHT. /28/
&&
.PREV DISCUSSION... /ISSUED 506 AM CDT WED JUL 24 2013/
UPDATE...DID A QUICK UPDATE TO INCLUDE MENTION OF SOME LIGHT RAIN
ACROSS THE REGION THAT CONTINUES TO EXPAND TO THE NORTH/NORTHEAST OF
THE MCV OVER NE LA. A TRANSITION TO MORE SHOWERY ACTIVITY EXPECTED
LATER THIS MORNING. /BK/
PREV DISCUSSION... /ISSUED 431 AM CDT WED JUL 24 2013/
SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)...
COMPLICATED NORTHWEST FLOW REGIME PERSISTS OVER THE NEXT COUPLE
DAYS...ALTHOUGH THINGS WILL SIMPLIFY A TAD HEADED INTO TOMORROW AS A
COOL FRONT DRIFTS INTO THE AREA FROM THE NORTH. BUT BEFORE THEN WE
NEED TO DEAL WITH A RATHER UNCERTAIN FORECAST FOR TODAY. A REMNANT
MCV FROM A CONVECTIVE COMPLEX THAT DIED TO OUR WEST LAST NIGHT IS
CURRENTLY DRIFTING ACROSS NORTHEAST LOUISIANA TOWARD SOUTHWEST
MISSISSIPPI AT THIS HOUR...WITH A BROAD CIRRUS SHIELD TRYING TO
OVERSPREAD THE REGION FROM THE NORTHWEST. THESE TWO ITEMS ARE GOING
TO MAKE A CONVECTIVE FORECAST FOR TODAY RATHER DIFFICULT AS
CONVERGENCE IN VICINITY OF THE MCV CALLS FOR INITIATION IN ITS
VICINITY ONCE WE HEAT UP...WITH EXPANSIVE UPPER CLOUD COVER LIMITING
THE HEATING POTENTIAL/AT LEAST FOR THE FIRST PART OF THE DAY.
FURTHER NORTH...THE SYNOPTIC COOL FRONT LOOKS TO BE PASSING INTO FAR
NORTHERN MS BY LATE MORNING WHICH SHOULD PROVIDE IMPETUS FOR SOME
STORMS IN ITS VICINITY AS LONG AS WE GET SOME HEATING UP THERE/BUT
THERE AGAIN THE EXPANSIVE CIRRUS SHIELD IS GOING TO MAKE THAT
DIFFICULT FOR SEVERAL MORE HOURS. THE BROADER SCALE MODELS DO NOT
SEEM TO HAVE A GOOD HANDLE ON WHAT IS GOING ON WHICH ISN`T
SURPRISING...HOWEVER THE LATEST RUNS OF THE HRRR DO LOOK REASONABLE
WITH THEIR EVOLUTION OF THINGS FOR TODAY AND HAVE LOOKED TO IT MORE
THAN ANYTHING FOR SOME CLUES. I WOULD NOT BE SURPRISED TO SEE THE
CIRRUS THIN HEADED INTO THE DAYBREAK HOURS ALLOWING SOME DECENT
HEATING TO OCCUR THIS MORNING ACROSS A GOOD MAJORITY OF THE REGION.
THIS IN CONJUNCTURE WITH THE REMNANT MCV AND SURFACE FRONT SHOULD
ALLOW A COUPLE FOCUS AREAS FOR STORMS TO DEVELOP...ONE ACROSS THE
I-20 CORRIDOR ON THE NORTHERN FRINGE OF THE MCV AND ANOTHER NORTH OF
OUR CWA INVOF THE FRONT. FROM THERE I`D EXPECT A GENERAL EXPANSION
TOWARD THE SOUTH/SOUTHEAST LIKE WE`VE SEEN ACROSS THE REGION THE
LAST COUPLE DAYS. THIS WOULD LEAVE A MINIMUM IN ACTIVITY ACROSS THE
DELTA TODAY...HOWEVER IF THE CIRRUS THINS UP THERE AS WELL AND WE
GET SOME HEATING A CONDITIONAL RISK OF STORMS FIRING IN THAT
VICINITY INVOF THE FRONT LOOKS POSSIBLE. AS FOR THE STRONG/SEVERE
RISK TODAY...RELIED HEAVILY ON THE LATEST RUNS OF THE RUC AND ITS
TEMPERATURE PROFILE TODAY WHICH LOOKS PRETTY MEAGER ON THE LAPSE
RATE FRONT GIVEN ALL THE CONVECTIVE DEBRIS/CIRRUS AROUND. COINCIDENT
WITH THE UNCERTAINTY IN WHERE THE BEST COVERAGE IN STORMS WILL BE
TODAY AM GOING TO LEAVE THE HWO PRETTY GENERAL WITH ALL AREAS
COVERED...AND WILL OMIT MENTION OF ANYTHING SEVERE UNTIL CONFIDENCE
INCREASES IN STRONGER HEATING/INSTABILITY DEVELOPING.
HEADED INTO TONIGHT...I WOULD NOT BE SURPRISED TO SEE THINGS QUIET
DOWN AREA WIDE BY MID TO LATE EVENING AS A LOSS OF HEATING COUPLES
WITH DRIER AIR ALOFT OVERSPREADING THE CWA. ISOLATED SHOWERS AND
PERHAPS A FEW RUMBLES OF THUNDER LOOK PLAUSIBLE ALONG THE ADVANCING
FRONT THROUGH THE NIGHT. BY THURSDAY MORNING THE FRONT LOOKS TO BE
LOCATED ALONG/JUST SOUTH OF THE I-20 CORRIDOR. THIS SHOULD CONFINE
ANY SHOWER AND STORM CHANCES TO SOUTHERN ZONES...AND AT THIS POINT
IT DOESN`T APPEAR STRONG STORMS WILL BE A HUGE CONCERN. WE`LL BE
TAKING A LOOK AT THAT AGAIN LATER TODAY/TONIGHT.
TEMPS OFFERED BY THE GFS MOS LOOKED WARM TODAY CONSIDERING THE
AFOREMENTIONED CLOUDS/CIRRUS AND STORM CHANCES FOR LATER ON. ONLY
OTHER NOTABLE CHANGES WERE FOR FRI MORNING WHERE TEMPS WERE RAISED A
TAD TOWARD WARMER NAM/ENSEMBLE NUMBERS. /BK/
LONG TERM...(FRIDAY THROUGH WEDNESDAY)...
FOCUS OF THE LONG TERM WILL BE ON A WELL DEFINED
DISTURBANCE FOR SATURDAY AND WHAT SORT OF PRECIP/IMPACTS IT COULD
BRING FOR THE FRIDAY NIGHT THROUGH SATURDAY NIGHT TIMEFRAME. OUTSIDE
THAT...A RETURN TO MORE TYPICAL SUMMER CONDITIONS ARE EXPECTED BY
NEXT WEEK AFTER A BRIEF VISIT BY A LATE JULY FRONTAL BOUNDARY.
ON FRI...WARM CONDITIONS WILL EXIST AS THE AREA SEES A STALLED SFC
FRONT LIFT BACK NORTHWARD AS A WARM FRONT. HUMIDITY LOOKS TO BE HELD
IN CHECK THANKS TO DRIER LOW LEVEL AIR IN PLACE. NO EXPECTING MUCH
IN THE WAY OF CONVECTION AS WARM 850MB TEMPS LOOK TO KEEP A CAP IN
PLACE AND LIMIT STORM POTENTIAL. TEMPS WILL RANGE FROM THE LOWER TO
MID 90S WITH THE WARMEST READINGS ACROSS THE SOUTH HALF.
BY FRI NGT AND INTO SAT...A COMPACT S/WV WILL DROP SE OUT OF THE
SOUTHERN PLAINS AND LIKELY HAVE SOME SORT OF STORM COMPLEX
ASSOCIATED WITH IT. MODELS HAVE BEEN CONSISTENT IN SHOWING THIS
FEATURE AND CONTINUE TO DO SO. IT APPEARS THAT AFTER MIDNIGHT FRI
NGT...THE NW/N HALF OF THE AREA COULD SEE THE REMNANTS OF A COMPLEX
MOVE ACROSS THE AREA. MODEL DATA ALSO AGREE THAT LINGERING PRECIP
CHANCES WILL EXIST ON SAT DUE TO CONTINUED EFFECTS OF LIFT AND LOW
LEVEL MOISTURE CONVERGENCE. DUE TO THIS...HIGH END CHANCE TO LIKELY
POPS WILL EXIST FOR THOSE TWO PERIODS. AT THIS TIME...ITS DIFFICULT
TO SAY WHAT SORT OF RISK THIS ACTIVITY MAY POSE TO THE CWA. AT A
MINIMUM IT SEEMS LIKE SOME STRONG STORMS AND HEAVY RAIN WILL BE
POSSIBLE. HOWEVER...WILL NOT MENTION ANY RISK AT THIS TIME IN
OFFICIAL PRODUCTS AND SEE HOW THINGS PLAY OUT OVER THE NEXT FEW
MODEL RUNS. AS FOR TEMPS...HIGHS SAT LOOK TO BE HELD IN CHECK QUITE
A BIT AS PRECIP/CLOUDS WILL KEEP READINGS QUITE A BIT BELOW AVG.
FOR SAT NGT THROUGH WED...THERE WILL LIKELY BE SOME LINGERING PRECIP
CHANCES FOR SAT NGT INTO SUN AS A WEAK SFC FRONT WILL BE CLOSE TO
THE AREA AND SOME LINGERING MID LEVEL SHEAR STILL EXISTS FROM THE
LEFT OVER TROUGH AXIS. THIS SFC FRONT MAY BRIEFLY BRING SOME LOWER
DEWPTS TO THE AREA SUN INTO MON AND HELP TAKE THE EDGE OFF HUMIDITY.
HOWEVER...THIS BOUNDARY LOOKS TO WASH OUT AND MORE NORMAL SUMMERTIME
TEMPS/HUMIDITY SHOULD RETURN. THE PATTERN COULD BRING SOME SURPRISES
AS IT WILL STILL HAVE SOME HINTS OF A NW FLOW REGIME. /CME/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 91 72 93 67 / 54 17 14 6
MERIDIAN 90 72 93 64 / 55 17 14 7
VICKSBURG 91 70 93 66 / 43 18 14 6
HATTIESBURG 90 73 94 69 / 56 22 22 14
NATCHEZ 90 72 91 69 / 38 26 21 12
GREENVILLE 90 71 91 66 / 54 15 4 7
GREENWOOD 90 70 90 64 / 58 15 5 6
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/28/BK/CME
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
506 AM CDT WED JUL 24 2013
.UPDATE...DID A QUICK UPDATE TO INCLUDE MENTION OF SOME LIGHT RAIN
ACROSS THE REGION THAT CONTINUES TO EXPAND TO THE NORTH/NORTHEAST OF
THE MCV OVER NE LA. A TRANSITION TO MORE SHOWERY ACTIVITY EXPECTED
LATER THIS MORNING. /BK/
&&
.PREV DISCUSSION... /ISSUED 431 AM CDT WED JUL 24 2013/
SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)...
COMPLICATED NORTHWEST FLOW REGIME PERSISTS OVER THE NEXT COUPLE
DAYS...ALTHOUGH THINGS WILL SIMPLIFY A TAD HEADED INTO TOMORROW AS A
COOL FRONT DRIFTS INTO THE AREA FROM THE NORTH. BUT BEFORE THEN WE
NEED TO DEAL WITH A RATHER UNCERTAIN FORECAST FOR TODAY. A REMNANT
MCV FROM A CONVECTIVE COMPLEX THAT DIED TO OUR WEST LAST NIGHT IS
CURRENTLY DRIFTING ACROSS NORTHEAST LOUISIANA TOWARD SOUTHWEST
MISSISSIPPI AT THIS HOUR...WITH A BROAD CIRRUS SHIELD TRYING TO
OVERSPREAD THE REGION FROM THE NORTHWEST. THESE TWO ITEMS ARE GOING
TO MAKE A CONVECTIVE FORECAST FOR TODAY RATHER DIFFICULT AS
CONVERGENCE IN VICINITY OF THE MCV CALLS FOR INITIATION IN ITS
VICINITY ONCE WE HEAT UP...WITH EXPANSIVE UPPER CLOUD COVER LIMITING
THE HEATING POTENTIAL/AT LEAST FOR THE FIRST PART OF THE DAY.
FURTHER NORTH...THE SYNOPTIC COOL FRONT LOOKS TO BE PASSING INTO FAR
NORTHERN MS BY LATE MORNING WHICH SHOULD PROVIDE IMPETUS FOR SOME
STORMS IN ITS VICINITY AS LONG AS WE GET SOME HEATING UP THERE/BUT
THERE AGAIN THE EXPANSIVE CIRRUS SHIELD IS GOING TO MAKE THAT
DIFFICULT FOR SEVERAL MORE HOURS. THE BROADER SCALE MODELS DO NOT
SEEM TO HAVE A GOOD HANDLE ON WHAT IS GOING ON WHICH ISN`T
SURPRISING...HOWEVER THE LATEST RUNS OF THE HRRR DO LOOK REASONABLE
WITH THEIR EVOLUTION OF THINGS FOR TODAY AND HAVE LOOKED TO IT MORE
THAN ANYTHING FOR SOME CLUES. I WOULD NOT BE SURPRISED TO SEE THE
CIRRUS THIN HEADED INTO THE DAYBREAK HOURS ALLOWING SOME DECENT
HEATING TO OCCUR THIS MORNING ACROSS A GOOD MAJORITY OF THE REGION.
THIS IN CONJUNCTURE WITH THE REMNANT MCV AND SURFACE FRONT SHOULD
ALLOW A COUPLE FOCUS AREAS FOR STORMS TO DEVELOP...ONE ACROSS THE
I-20 CORRIDOR ON THE NORTHERN FRINGE OF THE MCV AND ANOTHER NORTH OF
OUR CWA INVOF THE FRONT. FROM THERE I`D EXPECT A GENERAL EXPANSION
TOWARD THE SOUTH/SOUTHEAST LIKE WE`VE SEEN ACROSS THE REGION THE
LAST COUPLE DAYS. THIS WOULD LEAVE A MINIMUM IN ACTIVITY ACROSS THE
DELTA TODAY...HOWEVER IF THE CIRRUS THINS UP THERE AS WELL AND WE
GET SOME HEATING A CONDITIONAL RISK OF STORMS FIRING IN THAT
VICINITY INVOF THE FRONT LOOKS POSSIBLE. AS FOR THE STRONG/SEVERE
RISK TODAY...RELIED HEAVILY ON THE LATEST RUNS OF THE RUC AND ITS
TEMPERATURE PROFILE TODAY WHICH LOOKS PRETTY MEAGER ON THE LAPSE
RATE FRONT GIVEN ALL THE CONVECTIVE DEBRIS/CIRRUS AROUND. COINCIDENT
WITH THE UNCERTAINTY IN WHERE THE BEST COVERAGE IN STORMS WILL BE
TODAY AM GOING TO LEAVE THE HWO PRETTY GENERAL WITH ALL AREAS
COVERED...AND WILL OMIT MENTION OF ANYTHING SEVERE UNTIL CONFIDENCE
INCREASES IN STRONGER HEATING/INSTABILITY DEVELOPING.
HEADED INTO TONIGHT...I WOULD NOT BE SURPRISED TO SEE THINGS QUIET
DOWN AREA WIDE BY MID TO LATE EVENING AS A LOSS OF HEATING COUPLES
WITH DRIER AIR ALOFT OVERSPREADING THE CWA. ISOLATED SHOWERS AND
PERHAPS A FEW RUMBLES OF THUNDER LOOK PLAUSIBLE ALONG THE ADVANCING
FRONT THROUGH THE NIGHT. BY THURSDAY MORNING THE FRONT LOOKS TO BE
LOCATED ALONG/JUST SOUTH OF THE I-20 CORRIDOR. THIS SHOULD CONFINE
ANY SHOWER AND STORM CHANCES TO SOUTHERN ZONES...AND AT THIS POINT
IT DOESN`T APPEAR STRONG STORMS WILL BE A HUGE CONCERN. WE`LL BE
TAKING A LOOK AT THAT AGAIN LATER TODAY/TONIGHT.
TEMPS OFFERED BY THE GFS MOS LOOKED WARM TODAY CONSIDERING THE
AFOREMENTIONED CLOUDS/CIRRUS AND STORM CHANCES FOR LATER ON. ONLY
OTHER NOTABLE CHANGES WERE FOR FRI MORNING WHERE TEMPS WERE RAISED A
TAD TOWARD WARMER NAM/ENSEMBLE NUMBERS. /BK/
LONG TERM...(FRIDAY THROUGH WEDNESDAY)...
FOCUS OF THE LONG TERM WILL BE ON A WELL DEFINED
DISTURBANCE FOR SATURDAY AND WHAT SORT OF PRECIP/IMPACTS IT COULD
BRING FOR THE FRIDAY NIGHT THROUGH SATURDAY NIGHT TIMEFRAME. OUTSIDE
THAT...A RETURN TO MORE TYPICAL SUMMER CONDITIONS ARE EXPECTED BY
NEXT WEEK AFTER A BRIEF VISIT BY A LATE JULY FRONTAL BOUNDARY.
ON FRI...WARM CONDITIONS WILL EXIST AS THE AREA SEES A STALLED SFC
FRONT LIFT BACK NORTHWARD AS A WARM FRONT. HUMIDITY LOOKS TO BE HELD
IN CHECK THANKS TO DRIER LOW LEVEL AIR IN PLACE. NO EXPECTING MUCH
IN THE WAY OF CONVECTION AS WARM 850MB TEMPS LOOK TO KEEP A CAP IN
PLACE AND LIMIT STORM POTENTIAL. TEMPS WILL RANGE FROM THE LOWER TO
MID 90S WITH THE WARMEST READINGS ACROSS THE SOUTH HALF.
BY FRI NGT AND INTO SAT...A COMPACT S/WV WILL DROP SE OUT OF THE
SOUTHERN PLAINS AND LIKELY HAVE SOME SORT OF STORM COMPLEX
ASSOCIATED WITH IT. MODELS HAVE BEEN CONSISTENT IN SHOWING THIS
FEATURE AND CONTINUE TO DO SO. IT APPEARS THAT AFTER MIDNIGHT FRI
NGT...THE NW/N HALF OF THE AREA COULD SEE THE REMNANTS OF A COMPLEX
MOVE ACROSS THE AREA. MODEL DATA ALSO AGREE THAT LINGERING PRECIP
CHANCES WILL EXIST ON SAT DUE TO CONTINUED EFFECTS OF LIFT AND LOW
LEVEL MOISTURE CONVERGENCE. DUE TO THIS...HIGH END CHANCE TO LIKELY
POPS WILL EXIST FOR THOSE TWO PERIODS. AT THIS TIME...ITS DIFFICULT
TO SAY WHAT SORT OF RISK THIS ACTIVITY MAY POSE TO THE CWA. AT A
MINIMUM IT SEEMS LIKE SOME STRONG STORMS AND HEAVY RAIN WILL BE
POSSIBLE. HOWEVER...WILL NOT MENTION ANY RISK AT THIS TIME IN
OFFICIAL PRODUCTS AND SEE HOW THINGS PLAY OUT OVER THE NEXT FEW
MODEL RUNS. AS FOR TEMPS...HIGHS SAT LOOK TO BE HELD IN CHECK QUITE
A BIT AS PRECIP/CLOUDS WILL KEEP READINGS QUITE A BIT BELOW AVG.
FOR SAT NGT THROUGH WED...THERE WILL LIKELY BE SOME LINGERING PRECIP
CHANCES FOR SAT NGT INTO SUN AS A WEAK SFC FRONT WILL BE CLOSE TO
THE AREA AND SOME LINGERING MID LEVEL SHEAR STILL EXISTS FROM THE
LEFT OVER TROUGH AXIS. THIS SFC FRONT MAY BRIEFLY BRING SOME LOWER
DEWPTS TO THE AREA SUN INTO MON AND HELP TAKE THE EDGE OFF HUMIDITY.
HOWEVER...THIS BOUNDARY LOOKS TO WASH OUT AND MORE NORMAL SUMMERTIME
TEMPS/HUMIDITY SHOULD RETURN. THE PATTERN COULD BRING SOME SURPRISES
AS IT WILL STILL HAVE SOME HINTS OF A NW FLOW REGIME. /CME/
&&
.AVIATION...
STUBBORN IFR STRATUS PLAGUING KGTR WHICH SHOULD PERSIST
FOR A FEW MORE HRS BEFORE THINGS TREND VFR. ELSEWHERE VFR CONDS TO
PREVAIL WITH JUST A LOW CHANCE OF SEEING SOME IFR CIG AT HBG/PIB/MEI
THRU 13Z. ANOTHER ROUND OF SHRA/TSRA WL LIKELY IMPACT MOST AREAS
AFTER 17Z TODAY W/THIS ACTIVITY ON THE DOWNWARD TREND THIS EVENING/
OVRNGT. SFC WINDS WL BE GENERALLY OUT OF THE W/THRU THE PERIOD AND
MAY OCCASIONALLY GUST THIS AFTN. GENERALLY QUIET WX XPCTD OVRNGHT.
/BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 91 72 93 67 / 50 17 14 6
MERIDIAN 91 72 93 64 / 56 17 14 7
VICKSBURG 91 70 93 66 / 46 18 14 6
HATTIESBURG 91 73 94 69 / 61 22 22 14
NATCHEZ 90 72 91 69 / 41 26 21 12
GREENVILLE 89 71 91 66 / 50 15 4 7
GREENWOOD 90 70 90 64 / 50 15 5 6
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON MS
431 AM CDT WED JUL 24 2013
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)...
COMPLICATED NORTHWEST FLOW REGIME PERSISTS OVER THE NEXT COUPLE
DAYS...ALTHOUGH THINGS WILL SIMPLIFY A TAD HEADED INTO TOMORROW AS A
COOL FRONT DRIFTS INTO THE AREA FROM THE NORTH. BUT BEFORE THEN WE
NEED TO DEAL WITH A RATHER UNCERTAIN FORECAST FOR TODAY. A REMNANT
MCV FROM A CONVECTIVE COMPLEX THAT DIED TO OUR WEST LAST NIGHT IS
CURRENTLY DRIFTING ACROSS NORTHEAST LOUISIANA TOWARD SOUTHWEST
MISSISSIPPI AT THIS HOUR...WITH A BROAD CIRRUS SHIELD TRYING TO
OVERSPREAD THE REGION FROM THE NORTHWEST. THESE TWO ITEMS ARE GOING
TO MAKE A CONVECTIVE FORECAST FOR TODAY RATHER DIFFICULT AS
CONVERGENCE IN VICINITY OF THE MCV CALLS FOR INITIATION IN ITS
VICINITY ONCE WE HEAT UP...WITH EXPANSIVE UPPER CLOUD COVER LIMITING
THE HEATING POTENTIAL/AT LEAST FOR THE FIRST PART OF THE DAY.
FURTHER NORTH...THE SYNOPTIC COOL FRONT LOOKS TO BE PASSING INTO FAR
NORTHERN MS BY LATE MORNING WHICH SHOULD PROVIDE IMPETUS FOR SOME
STORMS IN ITS VICINITY AS LONG AS WE GET SOME HEATING UP THERE/BUT
THERE AGAIN THE EXPANSIVE CIRRUS SHIELD IS GOING TO MAKE THAT
DIFFICULT FOR SEVERAL MORE HOURS. THE BROADER SCALE MODELS DO NOT
SEEM TO HAVE A GOOD HANDLE ON WHAT IS GOING ON WHICH ISN`T
SURPRISING...HOWEVER THE LATEST RUNS OF THE HRRR DO LOOK REASONABLE
WITH THEIR EVOLUTION OF THINGS FOR TODAY AND HAVE LOOKED TO IT MORE
THAN ANYTHING FOR SOME CLUES. I WOULD NOT BE SURPRISED TO SEE THE
CIRRUS THIN HEADED INTO THE DAYBREAK HOURS ALLOWING SOME DECENT
HEATING TO OCCUR THIS MORNING ACROSS A GOOD MAJORITY OF THE REGION.
THIS IN CONJUNCTURE WITH THE REMNANT MCV AND SURFACE FRONT SHOULD
ALLOW A COUPLE FOCUS AREAS FOR STORMS TO DEVELOP...ONE ACROSS THE
I-20 CORRIDOR ON THE NORTHERN FRINGE OF THE MCV AND ANOTHER NORTH OF
OUR CWA INVOF THE FRONT. FROM THERE I`D EXPECT A GENERAL EXPANSION
TOWARD THE SOUTH/SOUTHEAST LIKE WE`VE SEEN ACROSS THE REGION THE
LAST COUPLE DAYS. THIS WOULD LEAVE A MINIMUM IN ACTIVITY ACROSS THE
DELTA TODAY...HOWEVER IF THE CIRRUS THINS UP THERE AS WELL AND WE
GET SOME HEATING A CONDITIONAL RISK OF STORMS FIRING IN THAT
VICINITY INVOF THE FRONT LOOKS POSSIBLE. AS FOR THE STRONG/SEVERE
RISK TODAY...RELIED HEAVILY ON THE LATEST RUNS OF THE RUC AND ITS
TEMPERATURE PROFILE TODAY WHICH LOOKS PRETTY MEAGER ON THE LAPSE
RATE FRONT GIVEN ALL THE CONVECTIVE DEBRIS/CIRRUS AROUND. COINCIDENT
WITH THE UNCERTAINTY IN WHERE THE BEST COVERAGE IN STORMS WILL BE
TODAY AM GOING TO LEAVE THE HWO PRETTY GENERAL WITH ALL AREAS
COVERED...AND WILL OMIT MENTION OF ANYTHING SEVERE UNTIL CONFIDENCE
INCREASES IN STRONGER HEATING/INSTABILITY DEVELOPING.
HEADED INTO TONIGHT...I WOULD NOT BE SURPRISED TO SEE THINGS QUIET
DOWN AREA WIDE BY MID TO LATE EVENING AS A LOSS OF HEATING COUPLES
WITH DRIER AIR ALOFT OVERSPREADING THE CWA. ISOLATED SHOWERS AND
PERHAPS A FEW RUMBLES OF THUNDER LOOK PLAUSIBLE ALONG THE ADVANCING
FRONT THROUGH THE NIGHT. BY THURSDAY MORNING THE FRONT LOOKS TO BE
LOCATED ALONG/JUST SOUTH OF THE I-20 CORRIDOR. THIS SHOULD CONFINE
ANY SHOWER AND STORM CHANCES TO SOUTHERN ZONES...AND AT THIS POINT
IT DOESN`T APPEAR STRONG STORMS WILL BE A HUGE CONCERN. WE`LL BE
TAKING A LOOK AT THAT AGAIN LATER TODAY/TONIGHT.
TEMPS OFFERED BY THE GFS MOS LOOKED WARM TODAY CONSIDERING THE
AFOREMENTIONED CLOUDS/CIRRUS AND STORM CHANCES FOR LATER ON. ONLY
OTHER NOTABLE CHANGES WERE FOR FRI MORNING WHERE TEMPS WERE RAISED A
TAD TOWARD WARMER NAM/ENSEMBLE NUMBERS. /BK/
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)...
FOCUS OF THE LONG TERM WILL BE ON A WELL DEFINED
DISTURBANCE FOR SATURDAY AND WHAT SORT OF PRECIP/IMPACTS IT COULD
BRING FOR THE FRIDAY NIGHT THROUGH SATURDAY NIGHT TIMEFRAME. OUTSIDE
THAT...A RETURN TO MORE TYPICAL SUMMER CONDITIONS ARE EXPECTED BY
NEXT WEEK AFTER A BRIEF VISIT BY A LATE JULY FRONTAL BOUNDARY.
ON FRI...WARM CONDITIONS WILL EXIST AS THE AREA SEES A STALLED SFC
FRONT LIFT BACK NORTHWARD AS A WARM FRONT. HUMIDITY LOOKS TO BE HELD
IN CHECK THANKS TO DRIER LOW LEVEL AIR IN PLACE. NO EXPECTING MUCH
IN THE WAY OF CONVECTION AS WARM 850MB TEMPS LOOK TO KEEP A CAP IN
PLACE AND LIMIT STORM POTENTIAL. TEMPS WILL RANGE FROM THE LOWER TO
MID 90S WITH THE WARMEST READINGS ACROSS THE SOUTH HALF.
BY FRI NGT AND INTO SAT...A COMPACT S/WV WILL DROP SE OUT OF THE
SOUTHERN PLAINS AND LIKELY HAVE SOME SORT OF STORM COMPLEX
ASSOCIATED WITH IT. MODELS HAVE BEEN CONSISTENT IN SHOWING THIS
FEATURE AND CONTINUE TO DO SO. IT APPEARS THAT AFTER MIDNIGHT FRI
NGT...THE NW/N HALF OF THE AREA COULD SEE THE REMNANTS OF A COMPLEX
MOVE ACROSS THE AREA. MODEL DATA ALSO AGREE THAT LINGERING PRECIP
CHANCES WILL EXIST ON SAT DUE TO CONTINUED EFFECTS OF LIFT AND LOW
LEVEL MOISTURE CONVERGENCE. DUE TO THIS...HIGH END CHANCE TO LIKELY
POPS WILL EXIST FOR THOSE TWO PERIODS. AT THIS TIME...ITS DIFFICULT
TO SAY WHAT SORT OF RISK THIS ACTIVITY MAY POSE TO THE CWA. AT A
MINIMUM IT SEEMS LIKE SOME STRONG STORMS AND HEAVY RAIN WILL BE
POSSIBLE. HOWEVER...WILL NOT MENTION ANY RISK AT THIS TIME IN
OFFICIAL PRODUCTS AND SEE HOW THINGS PLAY OUT OVER THE NEXT FEW
MODEL RUNS. AS FOR TEMPS...HIGHS SAT LOOK TO BE HELD IN CHECK QUITE
A BIT AS PRECIP/CLOUDS WILL KEEP READINGS QUITE A BIT BELOW AVG.
FOR SAT NGT THROUGH WED...THERE WILL LIKELY BE SOME LINGERING PRECIP
CHANCES FOR SAT NGT INTO SUN AS A WEAK SFC FRONT WILL BE CLOSE TO
THE AREA AND SOME LINGERING MID LEVEL SHEAR STILL EXISTS FROM THE
LEFT OVER TROUGH AXIS. THIS SFC FRONT MAY BRIEFLY BRING SOME LOWER
DEWPTS TO THE AREA SUN INTO MON AND HELP TAKE THE EDGE OFF HUMIDITY.
HOWEVER...THIS BOUNDARY LOOKS TO WASH OUT AND MORE NORMAL SUMMERTIME
TEMPS/HUMIDITY SHOULD RETURN. THE PATTERN COULD BRING SOME SURPRISES
AS IT WILL STILL HAVE SOME HINTS OF A NW FLOW REGIME. /CME/
&&
.AVIATION...STUBBORN IFR STRATUS PLAGUING KGTR WHICH SHOULD PERSIST
FOR A FEW MORE HRS BEFORE THINGS TREND VFR. ELSEWHERE VFR CONDS TO
PREVAIL WITH JUST A LOW CHANCE OF SEEING SOME IFR CIG AT HBG/PIB/MEI
THRU 13Z. ANOTHER ROUND OF SHRA/TSRA WL LIKELY IMPACT MOST AREAS
AFTER 17Z TODAY W/THIS ACTIVITY ON THE DOWNWARD TREND THIS EVENING/
OVRNGT. SFC WINDS WL BE GENERALLY OUT OF THE W/THRU THE PERIOD AND
MAY OCCASIONALLY GUST THIS AFTN. GENERALLY QUIET WX XPCTD OVRNGHT.
/BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 91 72 93 67 / 50 17 14 6
MERIDIAN 91 72 93 64 / 56 17 14 7
VICKSBURG 91 70 93 66 / 46 18 14 6
HATTIESBURG 91 73 94 69 / 61 22 22 14
NATCHEZ 90 72 91 69 / 41 26 21 12
GREENVILLE 89 71 91 66 / 50 15 4 7
GREENWOOD 90 70 90 64 / 50 15 5 6
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BK/CME
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
651 PM CDT Thu Jul 25 2013
.UPDATE...
Issued at 650 PM CDT THU JUL 25 2013
Light rain across the area is encountering a drier and more stable
airmass and continues to weaken. Rainfall amounts were generally
under a quarter of an inch with this activity.
Meanwhile convection continues to develop along a cold front from
western KS into northeast NE and northern IA. These storms are not
quite as robust as several models had predicted, and as the airmass
ahead of them continues to stabilize it may be difficult to maintain
widespread convection overnight into our forecast area. Therefore
trimmed overnight PoPs down into chance category given the
uncertainty.
&&
.SHORT TERM...(This Evening through Friday)
Issued at 345 PM CDT THU JUL 25 2013
A weak short wave trough moving through the northwest flow will
bring a few showers and thunderstorms overnight. The main challenge
will be deciding how much of the area will stay intact as it moves
from Kansas and Nebraska towards Missouri. The HRRR is a little slow
but has the conceptual idea of pattern right so will follow that for
the first period. As the sun sets some of the convection may
diminish and most concentrated area will likely pass to the
southwest of the CWA anyway. Still, the NAM is showing some mid
level lapse rates around 6 K/KM and around 1.5 inches of
precipitable water over extreme eastern Kansas and western Missouri
with lower values to the east. Given the dry conditions at the
surface confidence is still fairly low for any widespread QPF
tonight.
Tomorrow...chances of precipitation will decreas across the area as
short wave trough exits that area. Still will be in northwest flow
and relative humidities drop through the day such that by evening
conditions should be cool and dry with light winds overnight.
Saturday will be picture perfect with low humidities and high
temperatures in the 70s.
.LONG TERM...(Friday Night through Thursday)
Issued at 345 PM CDT THU JUL 25 2013
For the last half of the forecast, below normal temperatures with a
decent chance at rain will be the dominate conditions. Pattern
across the country over the weekend will be dominated by a locally
northwest flow, within the larger amplified pattern in place
across the nation thanks to a cutoff low that will develop over the
Great Lakes this weekend. However, the low is not expected to hang
out for long as by late in the weekend it will have migrated far
enough to the northeast to allow the prevailing flow across the
Plains to return to a zonal pattern.
Over the later half of the weekend, temperatures will remain rather
cool for late July, with highs from the 70s into the 80s. These
pleasant conditions should persist into the work week even as the
zonal flow allows temperatures to moderate up some going into the
work week. Ultimately, the thermal ridge will remain to our west as
the flow adjusts through the beginning of the work week, thus
sparing the region from the oppressively hot temperatures more
typical of late July.
Otherwise, our precipitation chances for early in the work week are
looking rather decent, though persistence considerations leaves
confidence lower than the POPs advertised. As the pattern
flattens out across the nation Sunday night into Monday a shortwave
trough will shift across the center of the nation. Medium range
models have been keying on this shortwave for precipitation, though
the latest runs have slide the periods of focus for the storms from
Sunday night more fully into Monday and Tuesday over the last
several runs. Models continue to robustly advertise storms in these
early work week periods as isentropic lift and moisture transport
spread into Kansas and Missouri, therefore have kept going with
likely POPs for Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 650 PM CDT THU JUL 25 2013
Light rain is moving out of the area this evening, and radar trends
suggest most of the remainder of the night should be dry. Currently
watching storms that are developing along a cold front across
Nebraska and Iowa. While most models are bringing this activity into
eastern KS and northern MO just before sunrise, confidence in this
pattern remains low. Therefore will only carry a VCTS in the TAFs for
now, thinking any given terminal has a 40-50 percent chance of
seeing early morning storms at this point.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...Hawblitzel
SHORT TERM...Adolphson
LONG TERM...Cutter
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1221 AM CDT WED JUL 24 2013
.UPDATE...
ISSUED AT 708 PM CDT TUE JUL 23 2013
AS OF 00Z KUEX INDICATES DEEP CONVECTION HAS MOVED SOUTH OF OUR
CWA CLOSER TO THE I-70 CORRIDOR. IN ADDITION...DEEP CONVECTION
OVER THE HIGH PLAINS OF WESTERN NEBRASKA IS MOVING MORE SOUTHERLY
AND IF THESE TRENDS CONTINUE...SHOULD MISS OUR CWA TO THE WEST.
BARRING ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT TO OUR
NORTHWEST THIS EVENING AND TONIGHT...DRY CONDITIONS SHOULD PREVAIL
AND AS A RESULT...POPS HAVE BEEN REMOVED FROM THE FORECAST AND
ASSOCIATED SEVERE WEATHER WORDING REMOVED FROM THE HWO.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM CDT TUE JUL 23 2013
THE MAIN FOCUS FOR THIS EVENING/TONIGHT IS ON TSTM POTENTIAL.
CONVECTION WAS ONGOING FOR MUCH OF THE DAY TODAY BUT IN THE LAST FEW
HOURS THIS ACTIVITY HAS DISSIPATED. THE CAP REMAINS STRONG ACROSS
OUR SOUTHERN ZONES WITH THE MAIN BOUNDARY/WARM FRONT ORIENTED ACROSS
SOUTHERN KANSAS.
THIS BEING SAID...REMNANT OUTFLOW BOUNDARIES/DIFFERENTIAL HEATING
BOUNDARIES RESIDE ACROSS OUR CWA WITH THE NORTHERN TWO THIRDS OF OUR
CWA REMAINING UNCAPPED. ONE SUCH BOUNDARY FOR OUR CWA IS ORIENTED
NEAR THE NEB/KS STATE LINE AND CANNOT RULE OUT STRONG/SEVERE STORMS
IN THIS AREA AS BOUNDARY SAGS SOUTH WITH INSTABILITY ON THE ORDER OF
2000 TO 3000 J/KG AND GOOD SHEAR IN OUR NW FLOW REGIME. FARTHER
NORTH...A HIT OR MISS SHOWER/STORM CANNOT BE RULED OUT AS SUBTLE
SHORTWAVE TROUGHS TRANSLATE SE ACROSS THE INTERIOR CONUS. FARTHER
UPSTREAM...NEW STORMS ARE DEVELOPING ACROSS WESTERN SOUTH DAKOTA IN
A SIMILAR MANNER AS 24HRS AGO...BUT CONFIDENCE IS NOT HIGH THAT
THESE STORMS WILL SUSTAIN INTO THE OVERNIGHT HOURS TO IMPACT OUR
REGION...BUT WILL NEED TO MONITOR. THE HRRR TRACKS THIS ACTIVITY
TO THE WEST OF OUR CWA.
ASIDE FM THE HIT OR MISS STORM POTENTIAL...WE ARE LOOKING AT FAIRLY
SEASONAL CONDITIONS OR PERHAPS A FEW DEGREES COOLER THAN NORMAL BOTH
TONIGHT AND WEDNESDAY. A SFC RIDGE AXIS WILL BUILD TO THE SOUTHWEST
FM THE UPPER MIDWEST AND COOLER AIR WILL BACK IN FM THE NORTHEAST.
SFC DPS DROP SEVERAL DEGREES AND OVERNIGHT LOWS SHLD AVERAGE IN THE
UPPER 50S TO LOW 60S. MODELS INDICATE SOME POTENTIAL FOR SOME LOW
CLOUDS AROUND TONIGHT/EARLY WEDNESDAY...MAINLY IN KS. THERE ARE
SOME MODEL DIFFERENCES ON HIGHS FOR WEDNESDAY BUT WITH THE AIRMASS
MORE SIMILAR TO TODAY...WILL AIM FOR HIGH TEMPS IN THE MID/UPPER 80S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 PM CDT TUE JUL 23 2013
OVER THE PAST SEVERAL DAYS...MORE AND MORE OF THE CWA HAS
GRADUALLY RECEIVED AT LEAST MINIMAL AMOUNTS OF MEANINGFUL
MEASURABLE RAIN AFTER A VERY DRY START TO THE MONTH...AND THIS
TREND OF VARIOUS...HIT-AND-MISS RAIN CHANCES IN WHICH PARTS OF
THE AREA SEE DECENT PRECIPITATION WHILE OTHERS LARGELY MISS OUT IS
EXPECTED TO CONTINUE THROUGH THE FORECAST PERIOD. AT THIS
TIME...ALL RAIN CHANCES OVER THIS 6-DAY PERIOD HAVE BEEN CAPPED AT
NO MORE THAN 30-50 PERCENT...UNTIL/UNLESS CONFIDENCE INCREASES.
ALTHOUGH VERY SUBJECT TO CHANGE...THE THURS/THURS NIGHT AND SUN
NIGHT/MONDAY TIME FRAMES CURRENTLY CONTAIN THE OVERALL-HIGHEST
COVERAGE OF 30+ POPS. REGARDING SEVERE WEATHER PROSPECTS...ITS
AGAIN MUCH THE SAME STORY AS ALTHOUGH ITS QUITE POSSIBLE...IF NOT
LIKELY...THAT AT LEAST A FEW SEVERE STORMS FLARE UP FROM TIME TO
TIME...THERE IS NO DEFINITIVE SETUP OF HEIGHTENED CONCERN EVIDENT
AT THIS TIME...AND THUS HAVE REFRAINED FROM SPECIFYING ANY PERIODS
IN THE HAZARDOUS WEATHER OUTLOOK. ON A POSITIVE NOTE FOR MOST
FOLKS...THERE IS PRETTY HIGH CONFIDENCE IN A CONTINUED SLIGHTLY BELOW
NORMAL TEMPERATURE REGIME...WITH HIGHS ON MOST DAYS AVERAGING 3-8
DEGREES BELOW AVERAGE LATE-JULY VALUES.
STARTING OFF WEDNESDAY EVENING/NIGHT...SEASONABLY STRONG
NORTHWEST FLOW REMAINS IN PLACE OVER THE CENTRAL PLAINS...BETWEEN
RIDGING CENTERED OVER THE NV/CA/UT/AZ BORDER AREA...AND A BROAD
LONGWAVE TROUGH OVER THE EASTERN CONUS...WHILE A SHORTWAVE TROUGH
DIVES SOUTH-SOUTHEAST ACROSS MANITOBA/SASKATCHEWAN. WITHIN THE
LOCAL FLOW...A LOW-AMPLITUDE SHORTWAVE TROUGH IS PROGGED TO RIDE
EASTWARD ALONG THE KS/NE BORDER OUT OF NORTHEAST CO AS THE NIGHT
WEARS ON. ALTHOUGH INSTABILITY APPEARS PRETTY MINIMAL
LOCALLY...HAVE EXPANDED SLIGHT CHANCES FOR STORMS ACROSS MUCH OF
THE WESTERN HALF OF THE CWA POST-MIDNIGHT...WHILE LEAVING THE
EVENING HOURS DRY...AT LEAST FOR NOW. MADE LITTLE CHANGE OT LOW
TEMPS...WITH MID 60S MOST AREAS.
THURSDAY/THURSDAY NIGHT...POP-WISE MADE LITTLE CHANGE FROM
PREVIOUS FORECAST WITH A BROAD COVERAGE OF 30 POPS AND SOME 40S-
50S MAINLY FOCUSED IN SOUTHERN ZONES. ALOFT...ITS THE SAME OLD
THEME...WITH SUBTLE EMBEDDED SHORTWAVE TROUGHS WORKING OVER OR NEAR
THE CWA IN NORTHWEST FLOW...WHILE A STRONGER SHORTWAVE TROUGH
DROPS OUT OF CANADA INTO THE NORTHERN MN AREA. NOT
SURPRISINGLY...MODEL QPF FIELDS ARE OVER THE PLACE...WITH THE
ECMWF HITTING THE DAYTIME HOURS A LITTLE HARDER AND THE GFS THE
NIGHT. TEMP-WISE...WITH A RETURN TO MORE SOUTHERLY WINDS...NUDGED
UP HIGH TEMPS A LITTLE FROM PREVIOUS PER MET/MAV GUIDANCE BLEND...BUT
STILL ONLY MID 80S IN MOST AREAS.
FRIDAY/FRIDAY NIGHT...CONTINUED 20-30 POPS CWA-WIDE THIS ENTIRE
TIME...ALTHOUGH LARGE SCALE SUPPORT WANES A BIT FRIDAY NIGHT AS
THE AFOREMENTIONED GREAT LAKES REGION SHORTWAVE TROUGH CLOSES OFF
AND STARTS TO SLOWLY EDGE FARTHER EAST. IN THE WAKE OF A PASSING
COLD FRONT AND RETURN TO NORTHEAST BREEZES...HAVE HIGHS BACK DOWN
IN THE LOW 80S MOST NEB ZONES...AND MID 80S IN KS.
SATURDAY/SATURDAY NIGHT...CAME VERY CLOSE TO LEAVING THE CWA VOID
OF THUNDERSTORM MENTION DURING THE DAY PER PREVIOUS FORECAST...BUT
WENT AHEAD AND BROUGHT SOME SLIGHT POPS BACK INTO PARTS OF THE
SOUTHWEST 1/2 MAINLY PER THE 12Z ECMWF. SATURDAY NIGHT...HINTS OF
A SUBTLE SHORTWAVE TROUGH CONTINUE TO SUPPORT SLIGHT POPS AREA-
WIDE. HIGH TEMPS SATURDAY AGAIN LOW-MID 80S.
SUNDAY/SUNDAY NIGHT...THE LARGE-SCALE FLOW STARTS TO TURN
LEGITIMATELY MORE ZONAL VERSUS NORTHWESTERLY...IN THE WAKE OF THE
GREAT LAKES CLOSED LOW LIFTING BACK NORTHEAST INTO CANADA...BUT
THE TRAIN OF LOW AMPLITUDE DISTURBANCES INTO THE CENTRAL PLAINS
CONTINUES...AND HAVE SLIGHT POPS IN NEARLY ALL AREAS DURING THE
DAY...FOLLOWED BY 30-40 POPS SUNDAY NIGHT.
MONDAY/MONDAY NIGHT...CONTINUED QUASI-ZONAL FLOW WITH EMBEDDED
DISTURBANCES...AND HAVE AT LEAST SLIGHT POPS THROUGHOUT THIS 24
HOURS ALL AREAS...AND HIGHER VALUES CURRENTLY FOCUSED DURING THE
DAY. TEMP-WISE...LOW 80S NORTHEAST TO NEAR 90 SOUTHWEST.
TUESDAY...HAVE KEPT IT DRY FOR NOW...BUT ITS NO GUARANTEE TO STAY
THAT WAY...AS THERE IS OVERALL LITTLE CHANGE IN THE PATTERN.
POSSIBLY IN RESPONSE TO CLIMATOLOGY CARRYING MORE WEIGHT WITH
MODEL GUIDANCE AT THIS TIME RANGE...HIGHS TUESDAY ARE PRELIMINARILY
ADVERTISED TO BE A TOUCH WARMER THAN PREVIOUS DAYS...WITH MID 80S
NORTHEAST TO LOWER 90S SOUTHWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1220 AM CDT WED JUL 24 2013
OTHER THAN A FEW MID LEVEL CLOUDS DRIFTING THROUGH THE AREA THE
SKIES WILL BE PRIMARILY CLEAR THROUGH THE PERIOD. A SURFACE HIGH
PRESSURE SYSTEM SETTLES INTO THE AREA AND WINDS ARE EXPECTED TO BE
LIGHT AND VARIABLE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...PFANNKUCH
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS ELKO NV
903 PM PDT TUE JUL 23 2013
.SYNOPSIS...MONSOON MOISTURE IS IMPACTING NEVADA TODAY AND
TOMORROW PROVIDING INCREASING CLOUDS...ENHANCED CHANCES FOR
THUNDERSTORMS. THUNDERSTORMS ARE LIKELY ACROSS CENTRAL NEVADA THIS
AFTERNOON AND EVENING WHERE SOME WILL PRODUCE HEAVY RAINFALL. MORE
CONVECTION IS POSSIBLE TOMORROW AFTERNOON.
&&
.UPDATE...MOSTLY CLOUDY TO CLOUDY SKIES CAN BE SEEN ACROSS THE
ENTIRE FORECAST AREA. PRECIPITATION AT THIS TIME IS LIMITED TO
PARTS OF THE WESTERN CWA. HAVE MASSAGED OVERNIGHT POPS BASED ON
LATEST MODEL GUIDANCE...BUT HAVE KEPT AT LEAST ISOLATED THUNDER
THROUGH THE OVERNIGHT. ALL PRODUCTS WILL BE SENT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED AT 318 PM /
SHORT TERM...THIS AFTERNOON THROUGH THURSDAY. A REMNANT UPPER
LOW OVER THE SILVER STATE AND DEEP MOISTURE NEARING 200 PERCENT OF
NORMAL NEAR LAS VEGAS ARE NEARLY COINCIDENT WITH VISIBLE SATELLITE
IMAGERY SHOWING CUMULUS CLOUDS. THE MOISTURE ALONG WITH DIFFERENTIAL
HEATING ZONES...WILL LEND ITSELF TOWARDS RIPE CONVECTION. THE
RADAR HAS ALREADY PINGED INTO A NUMBER OF THUNDERSTORMS TODAY
WHICH IS CONSISTENT WITH THE NAM12 AND THE HRRR FOR ENHANCED CAPE
AND LIFTED INDICES. MORE THUNDERSTORMS EXPECTED TOMORROW
AFTERNOON.
LONG TERM...THURSDAY NIGHT THROUGH NEXT TUESDAY. THE MODELS ARE IN
FAIRLY GOOD AGREEMENT THROUGH TUESDAY. THE GENERAL SCENARIO IS FOR
ABOVE-NORMAL TEMPERATURES TO CONTINUE. THE RIDGE OF HIGH PRESSURE
RESPONSIBLE FOR THE LATEST STRING OF VERY WARM TEMPERATURES WILL
REMAIN STRONG THROUGH EARLY FRIDAY THEN BEGIN TO GET SUBDUED BY THE
INFUSION OF A LOW PRESSURE SYSTEM CROSSING EAST ACROSS THE SIERRAS
FOLLOWED BY A STRONGER UPPER LOW MOVING SOUTH FROM THE PACIFIC
NORTHWEST REGION. THE UPPER LOW WILL SLOWLY BEAR DOWN AND FLATTEN
THE RIDGE BY THE WEEKEND. SOME DAYTIME TEMPERATURES WILL FALL INTO
THE 80S OVER THE WEEKEND AND INTO EARLY NEXT WEEK. MODELS ARE
INDICATING A VERY UNSTABLE AIR MASS OVER CENTRAL NEVADA FOLLOWING
THE SURGE OF MOISTURE EXPECTED TODAY AND TOMORROW. DOWNDRAFT CAPE
VALUES SOUTH OF HIGHWAY 50 ARE GREATER THAN 1500 J/KG THROUGH
SATURDAY. PRECIPITABLE WATER VALUES ARE APPROACHING ONE INCH SOUTH
OF HIGHWAY 50. THE PROSPECT OF FLASH FLOODING FROM THUNDERSTORM
TRAINING ACROSS CENTRAL NEVADA MAY LINGER THROUGH SATURDAY DUE TO
THE LIGHT WINDS ALOFT...ESPECIALLY OVER THE RECENT BURN AREAS OF
NORTHERN NYE AND WHITE PINE COUNTIES...SPECIFICALLY THE WHITE PINE
FIRE AND THE BLACK FIRE. HUMBOLDT COUNTY WILL SEE THE LEAST AMOUNT
OF THUNDERSTORM ACTIVITY THROUGHOUT THE LONG TERM PERIOD AND
OVERNIGHT THUNDERSTORMS WILL BE PRIMARILY CONFINED TO THE SOUTHERN
HALF OF THE FORECAST AREA THROUGH FRIDAY NIGHT...THEN THE EASTERN
HALF SATURDAY AND SUNDAY AS A SHORTWAVE LOW TO THE NORTH NUDGES THE
MOISTURE AXIS EAST. THE SHOW MAY BE OVER BY TUESDAY AS THE
DEVELOPING PACIFIC TROUGH PROMISES TO SCOUR THE MOISTURE OUT OF THE
GREAT BASIN.
AVIATION...VFR CONDITIONS CAN BE EXPECTED THROUGH WEDNESDAY.
THUNDERSTORM ACTIVITY IS EXPECTED TO AFFECT KELY AND KTPH THROUGH
EARLY THIS EVENING. ISOLATED THUNDERSTORMS MAY AFFECT KELY AND KTPH
OVERNIGHT. THUNDERSTORM ACTIVITY IS EXPECTED TO AFFECT KWMC KEKO
KELY AND KTPH WEDNESDAY AFTERNOON AS THE MOISTURE FLUX INCREASES
ACROSS THE NORTH. BRIEF HEAVY RAINS AND STRONG GUSTY WINDS ARE
POSSIBLE WITH THESE STORMS.
FIRE WEATHER...A VERY UNUSUAL PATTERN HAS BEEN IN PLACE FOR THE
PAST TWO WEEKS. THIS UPPER LEVEL DISTURBANCE THAT IS CURRENTLY
OVER THE WESTERN GREAT BASIN...ORIGINALLY CAME FROM THE
MIDWEST...AKA...BACK EAST...WHERE A STRONG HIGH DEVELOPED CAUSING
THIS LOW TO RETROGRADE. THE SYSTEM HAS TAPPED INTO A FETCH OF MONSOON
MOISTURE. THE PWS OVER LAS VERY WERE ALMOST 200 PERCENT OF
NORMAL FROM THIS MORNINGS 12Z SOUNDING...REAL DATA NOT MODEL DATA.
TAKING THE GENESIS OF THIS PATTERN IN COMBINATION WITH AN UNSTABLE AIR
MASS WILL RESULT IN SCATTERED TO NUMEROUS THUNDERSTORMS CAPABLE OF
PRODUCING HEAVY RAIN ACROSS MUCH OF CENTRAL NEVADA. STORMS WILL BE
SLOW MOVING AND MAY TREK OVER THE SAME LOCATIONS...RESULTING IN
ENHANCED RAINFALL AMOUNTS.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 5 AM PDT WEDNESDAY FOR NORTHEASTERN NYE
COUNTY...NORTHWESTERN NYE COUNTY...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.
&&
$$
86/93
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
555 PM MDT THU JUL 25 2013
.AVIATION...
00Z TAF CYCLE
STORMS HAVE BEEN CONCENTRATED OVER WESTERN AND NORTHERN NEW
MEXICO TODAY...BUT WITH GENERALLY ISOLATED TO SCATTERED COVERAGE.
A LINE OF STORMS IS DEVELOPING IN NORTHEASTERN PARTS OF THE
STATE...AND THIS IS EXPECTED TO CONTINUE FILLING IN AS IT PUSHES
SOUTHWARD. OUTFLOW BOUNDARIES FROM CURRENT ACTIVITY WILL LIKELY
SPAWN ADDITIONAL CELLS INTO MORE OF CENTRAL NEW MEXICO THIS
EVENING...AND IN THE EAST CENTRAL TO SOUTHEASTERN PLAINS STORMS
MAY BE ONGOING INTO THE EARLY MORNING HOURS. THE TYPICAL HAZARDS
WILL ACCOMPANY STORM DOWNPOURS...INCLUDING REDUCED VISIBILITY AND
CEILINGS ALONG WITH LOCALIZED GUSTY OUTFLOW WINDS. IF OUTFLOWS
FROM STORMS CAN PROPAGATE WESTWARD THROUGH THE GAPS/CANYONS OF THE
CENTRAL MOUNTAIN CHAIN...SOME ACCELERATED GUSTY WINDS MAY DEVELOP
DOWNSTREAM TOWARD KABQ/KSAF.
52
&&
.PREV DISCUSSION...321 PM MDT THU JUL 25 2013...
ENHANCED NW TO SE STEERING FLOW IN PLACE ACROSS ROUGHLY
THE NE HALF OF THE FORECAST AREA TODAY RESULTING IN MUCH FASTER
STORM MOTIONS BUT ALSO GREATER STORM ORGANIZATION/STRUCTURE. THE
SW HALF CONTINUES UNDER THE INFLUENCE OF AN UPPER LEVEL COL REGION
BETWEEN TWO HIGH CENTERS...PRIMARY ONE OVER NW AZ AND A SECONDARY
CENTROID WEST OF THE TX BIG BEND REGION. AT LEAST TWO WELL-
DEFINED MESOSCALE CONVECTIVE VORTICES IN THE VICINITY OF OUR
SOUTHERN BORDER REGION BUT HOW THEY WILL MANIFEST THEMSELVES WITHIN
THE NEXT FEW HOURS AS DAYTIME HEATING/INSTABILITY PEAK IS UNCLEAR.
REGION OF VERY FAVORABLE 300-400 MB DEFORMATION IS DEFINITELY
CONTRIBUTING TO AN ACTIVE CROP OVER THE WEST AND A BIT FARTHER
NORTH THAN WHAT MODELS SUGGESTED.
WILL CONTINUE TO FOCUS THE BEST POPS ACROSS THE NC/NE AND
EVENTUALLY EC ZONES AS WELL AS THE WCC/SW. SHORT- WAVE TROUGH
BRUSHING NORTHEAST NEW MEXICO THROUGH THE REMAINDER OF THE
AFTERNOON WILL CONTINUE TO BOOST STORM COVERAGE/INTENSITY THERE
WITH A FEW STRONG/SEVERE STORMS A GOOD BET. SEWD-MOVING AND
GRADUALLY EXPANDING/DEEPENING COLD POOLS WILL LIKELY TOUCH OFF NEW
CONVECTION FARTHER SOUTH...AND THE LATEST HRRR STRONG SUGGESTS A
LARGER CONVECTIVE COMPLEX TAKING SHAPE ACROSS PARTS OF EC PLAINS.
EARLIER EXPANSION OF THE FLASH FLOOD WATCH NOT LOOKING GREAT THUS
FAR...BUT WILL LET RIDE FOR EVENING CREW TO REEVALUATE.
IN WAKE OF THE SUBTLE SHORT-WAVE FEATURE THIS AFTERNOON/EARLY
EVENING... MODELS ADVERTISE A NEW BACKDOOR FRONTAL BOUNDARY TO
SLOWLY MAKE ITS WAY SOUTH AND EVENTUALLY WEST DURING THE DAY
FRIDAY. SOMEWHAT DRIER/MORE STABLE AIR MASS EXPECTED TO LIMIT
CONVECTION ACROSS MUCH OF THE NE/EC PLAINS THOUGH LOW LEVEL UPSLOPE
SHOULD PROVE BENEFICIAL FOR THE EAST SLOPES OF THE SANGRES.
OTHERWISE...UPPER HIGH CENTERED TO OUR NORTHWEST SLOWLY BUILDS OUR
DIRECTION. THOUGH NOT AS ROBUST AS TODAY...A NW TO SE STEERING
FLOW WILL CONTINUE FAVOR THE HIGH PLAINS ON FRIDAY WITH THE
COMBINATION OF DEEPER MOISTURE/VERY WEAK STEERING FLOW FAVORING
THE WC/SW ZONES FOR PERSISTENT FLASH FLOOD THREAT.
THE UPPER HIGH WILL CONTINUE TO PRESS SOUTHWARD INTO THE WEEKEND
AND ESPECIALLY EARLY NEXT WEEK WITH A MARKED TREND TOWARD A DRIER
CONDITIONS BENEATH ENHANCED WEST TO EAST FLOW REGIME. IN OTHER
WORDS THE WESTERLIES LOOK TO RETURN AND STRONGLY SO ACROSS
NORTHERN AREAS OF THE STATE DURING THE EXTENDED.
.FIRE WEATHER...
A FAIRLY DYNAMIC DAY ON TAP AS A SHORTWAVE CAUGHT IN NORTHWEST FLOW
MOVES OVER THE CENTRAL AND SOUTHERN ROCKIES. STORMS HAVE FIRED UP
AHEAD OF THIS SHORTWAVE ACROSS NORTH CENTRAL AND NORTHEAST AREAS.
RESIDUAL MONSOONAL MOISTURE CAUGHT WITHIN A DEFORMATION ZONE OR
LIFTING ZONE IS FOUND ELSEWHERE. STORMS ARE GRADUALLY FIRING UP
WITHIN THIS ZONE. EXPECTING ANOTHER ACTIVE THUNDERSTORM DAY LASTING
THROUGH THE EVENING HOURS.
MODELS HAVE BEEN SHOWING SOME DRYING ACROSS THE NORTHWEST THIRD ON
FRIDAY. A BACK DOOR COLD FRONT WHICH WILL HAVE PUSHED INTO THE
EASTERN PLAINS TONIGHT FOLLOWING THE DISTURBANCE OR SHORTWAVE
PASSAGE WILL PROVIDE THE MAIN FOCUS FOR STORMS DURING THE AFTERNOON
AND EVENING FRIDAY. AS OF RIGHT NOW...THE MAIN FOCUS AREA WILL BE
FOUND ACROSS ZONE 109 EXTENDING NORTHEASTWARD TO THE SANGRE DE
CRISTOS. A MORE STABLE AIRMASS STILL LOOKS TO BE A LIMITER FOR
WETTING THUNDERSTORMS ACROSS THE FAR EASTERN PLAINS DURING THE
AFTERNOON HOURS. OVERALL...COVERAGE LOOKS TO BE SLIGHTLY LESS WITH
SLIGHTLY LESS HUMIDITY VERSUS TODAY.
MODELS ARE CONVERGING ON PLACING THE UPPER HIGH CENTER OVER FAR
SOUTHERN NM AND NORTHERN MEXICO ON SATURDAY. THE STEERING FLOW FOR THE
STORMS WOULD TURN MORE WEST TO EAST AS A RESULT. MOISTURE IS STILL
PLENTIFUL ACROSS ARIZONA SO THIS COULD ACTUALLY RESULT IN AN UPTICK
IN SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON/EVENING. THIS
INCLUDES THE ENTIRE EASTERN PLAINS DUE TO STEERING FLOW
CONSIDERATIONS. WETTING RAIN AND ABUNDANT CLOUD COVER WITH AN UPTICK
IN HUMIDITY IS A PRETTY GOOD BET.
THE CENTER OF THE UPPER HIGH SHOULD REMAIN OVER NORTHERN MEXICO ON
SUNDAY. BY THIS POINT...A FAIRLY STRONG SURFACE LOW FOR THIS TIME OF
YEAR IS EXPECTED TO DEVELOP TO THE LEE OF THE CENTRAL MOUNTAINS AND
THE WESTERLY FLOW ALOFT SHOULD ALSO INCREASE SOME. MODELS VARY
SOMEWHAT ON THE STRENGTH BUT THEY STILL POINT TOWARDS A DRIER
WESTERLY FLOW. BY THIS POINT...ARIZONA IS EXPECTED TO SEE A DOWNTURN
IN MOISTURE VALUES THUS DRIER AIR SHOULD EVENTUALLY ENTRAIN ACROSS
NEW MEXICO AS A RESULT. THIS WILL NOT TOTALLY ELIMINATE THUNDERSTORM
DEVELOPMENT BUT WOULD REDUCE THE COVERAGE AND WETTING RAIN FOOTPRINT
SOME. THE GFS AND ECMWF MODELS PAINT THE MAIN FOCUS AREA FOR WETTING
RAIN ACROSS THE NORTHERN TIER OF THE STATE AND SPECIALLY ACROSS
NORTH CENTRAL AND NORTHEAST AREAS. DID BUMP UP WIND SPEEDS WHICH
LOOK MORE LIKE MID JUNE SO WILL CONTINUE TO MONITOR THIS SCENARIO.
THE LATEST GFS AND ECMWF PAINT A FURTHER REDUCTION IN SHOWER AND
THUNDERSTORM COVERAGE ON MONDAY AS DRIER AIR INFILTRATES THE STATE
FROM THE WEST. MODELS ARE VERY BULLISH ON PAINTING VERY LITTLE
CONVECTION SO WILL BE INTERESTING TO SEE WHAT TURNS OUT. EITHER
WAY...EXPECTING DRIER AND WARMER CONDITIONS EARLY NEXT WEEK. AS THE
WEEK PROGRESSES...EXPECTING SOME SORT OF MOISTURE SEEPAGE AS THE
UPPER HIGH TRIES TO BUILD NORTHWARD AND PERHAPS EASTWARD. THE SEEPAGE WOULD
MOST LIKELY COME ALONG THE CONTINENTAL DIVIDE AS WELL AS VIA A WIND
SHIFT ACROSS THE NORTHEAST. EITHER WAY...WETTING THUNDERSTORMS LOOK
TO BE MORE ON THE MINIMAL KIND THROUGH THE EARLIER HALF OF NEXT
WEEK. PERHAPS INCREASING A BIT MORE THE LATTER HALF OF NEXT WEEK IF
THE HIGH SHIFTS OVER TEXAS. SOME OF THE MODELS ARE SHOWING THIS
TREND. IT SHOULD BE POINTED OUT THAT A 3 TO 4 DAY DOWNTREND IN
WETTING THUNDERSTORMS TYPICALLY OCCURS DURING THE MONSOON MOST YEARS
SO NOTHING TOO OUT OF THE ORDINARY BUT WILL KEEP AN EYE ON
SIGNIFICANT TRENDS...WHETHER THEY BE MOISTENING OR DRYING AS WE GO
FORWARD.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ508-509-520>526-532>540.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1112 AM MDT WED JUL 24 2013
.UPDATE...
BASED ON MOST RECENT HIGH RESOLUTION MODEL RUNS THE FLASH FLOOD WATCH
HAS BEEN EXTENDED GEOGRAPHICALLY TO INCLUDE UNION...HARDING...EASTERN
SAN MIGUEL AND GUADALUPE COUNTIES. AS A ENERGETIC UPPER LEVEL SHORTWAVE
TROUGH AXIS MOVES ACROSS THE FORECAST AREA OVERNIGHT THROUGH TOMORROW
MORNING THE THREAT FOR HEAVY RAINFALL HAS EXPANDED TO INCLUDE THE
ADDITIONAL COUNTIES MENTIONED IN NORTHEAST NEW MEXICO. SIMILARLY...
THE HEAVY RAINFALL THREAT WILL CONTINUE ACROSS THE ORIGINAL WATCH
AREA THROUGH TOMORROW MORNING AS WELL. ACCORDINGLY...THE ZONE FORECAST
PACKAGE HAS BEEN UPDATED.
&&
.PREV DISCUSSION...606 AM MDT WED JUL 24 2013...
.AVIATION...
12Z TAF CYCLE
MONSOON BURST EXPECTED TODAY AND THURSDAY AS A DEEP MONSOON
MOISTURE PLUME TRACKS N AND NE ACROSS THE FORECAST AREA WITH
AN EMBEDDED SUBTROPICAL PERTURBATION OR TWO. THE HRRR MODEL PROGS A
WAVE OF -SHRA AND EMBEDDED TS TRACKING NORTHWARD ACROSS W AND
CENTRAL NM TODAY...REACHING ABQ IN EARLY AFTN AND SAF BY LATE
AFTN. AN UPPER TROUGH IS EXPECTED TO BRUSH NORTHERN PARTS OF THE
STATE AS IT TRACKS E ACROSS CO TONIGHT. THIS SHOULD INVIGORATE TS
ALONG THE CENTRAL MT CHAIN THIS EVENING AND SEND A CLUSTER OR LINE
OF STORMS E ACROSS THE E CENTRAL AND NE PLAINS OVERNIGHT.
MEANWHILE...ECMWF AND GFS SUGGEST A SLOW MOVING SUBTROPICAL
PERTURBATION COULD LINGER OVER CENTRAL PARTS OF THE STATE TONIGHT
KEEPING SHOWERS AND POSSIBLY AN AREA OF STRATIFORM RAIN ACTIVE.
STRONGER STORMS TODAY THRU THURSDAY WILL BE CAPABLE OF PRODUCING WET
MICROBURSTS WITH VERY HEAVY RAIN AND BRIEF PERIODS OF IFR
CONDITIONS WITH MT OBSCURATIONS...ERRATIC WIND GUSTS OVER 45
KT AND FREQUENT/DANGEROUS LIGHTNING.
44
.PREV DISCUSSION...308 AM MDT WED JUL 24 2013...
THE AXIS OF MOIST INSTABILITY IS CENTERED SMACK DAB OVER NM THIS
MORNING. LATEST WATER VAPOR LOOP SHOWS THE MONSOON PLUME FROM SOUTH
TO NORTH WITH A PERTURBATION WASHING OUT ACROSS SOUTHERN NM. PWAT
VALUES ARE IMPRESSIVE PER CIRA IMAGERY AND REGIONAL SOUNDINGS. THE
GEFS AND SREF SOLUTIONS INDICATE THE 594DM H5 HIGH WILL SHIFT EAST
INTO WEST TX TODAY AND ALLOW A RATHER WELL DEFINED PERTURBATION TO
SLIDE NORTH INTO CENTRAL NM. PWAT VALUES ARE PROGGED TO AVERAGE THE
1.2-1.4 RANGE ALONG AND SOUTH OF I-40 BY THIS EVENING...WHICH IS
WELL WITHIN FLASH FLOOD TERRITORY. DEEP MOIST SSE ATMOSPHERIC FLOW
ALONG WITH A WEAK BOUNDARY SHIFTING SW OVER THE EASTERN PLAINS WILL
SET THE STAGE FOR SOME TRAINING CELLS. A GLIMPSE OF THE 05Z HRRR
SOLUTION SHOWS WIDESPREAD STORMS DEVELOPING FROM SOUTH TO NORTH
TODAY. WILL HOIST A FLASH FLOOD WATCH FOR POTENTIAL RAIN RATES NEAR
2 INCHES PER HOUR. STORM MOTIONS WILL AVERAGE ABOUT 15-20 KNOTS
HOWEVER CELL TRAINING MAY LEAD TO FLASH FLOODING...ESPECIALLY OVER
BURN SCARS.
BY THURSDAY THE UPPER HIGH REDEVELOPS OVER ARIZONA WITH LIGHT TO
MODERATE NW FLOW DEVELOPING ALOFT OVER NM. THIS WILL SHIFT THE
THETA-E RIDGE AXIS IN A SW-NE ORIENTATION...ALLOWING FOR MORE
WIDESPREAD ACTIVITY TO SLIDE INTO THE EASTERN PLAINS DURING THE
LATE AFTERNOON AND EVENING HOURS. ANOTHER FRONTAL BOUNDARY WILL
SHIFT DOWN THE PLAINS THURSDAY NIGHT AND FRIDAY FOCUSING MORE
HEAVY RAINFALL ALONG AND EAST OF THE CENTRAL MT CHAIN. PWAT VALUES
ARE PROGGED TO FALL BELOW 1.2 FOR MOST OF THE AREA SO FLASH FLOOD
THREAT MAY NOT BE AS HIGH...BUT WILL REVISIT AGAIN LATER TODAY.
THE FRIDAY/SATURDAY PERIOD WILL FEATURE MOISTURE RECYCLING OVER
WESTERN NM AS THE H5 HIGH SHIFTS BACK OVER CENTRAL/EASTERN NM.
STORM MOTIONS WILL BECOME VERY WEAK WITH LOCALLY HEAVY RAINFALL
OVER SMALLER FOOTPRINTS.
POTENTIAL IS INCREASING THAT AN EXTENDED TRUE MONSOONAL BURST PATTERN
WILL SET UP BY EARLY NEXT WEEK AS THE 700-500MB HIGH CENTROID SHIFTS
INTO TX. THIS WILL OPEN THE DOOR TO DEEP SUBTROPICAL AND MORE HEAVY
RAINFALL OVER NM. CLIMATOLOGICALLY WE ARE NOW IN THE MOST FLASHY
PERIOD OF THE MONSOON SO WILL JUST CONTINUE TO TREND POPS UP INTO
THE EXTENDED AS MODEL CONSISTENCY CONTINUES.
GUYER
.FIRE WEATHER...
A WAVE OF SUBTROPICAL ORIGIN THAT HAS BEEN STATIONARY IN THE
VICINITY OF EL PASO AND THE NM BOOTHEEL THE PAST COUPLE DAYS WILL
FINALLY SHIFT NORTHWARD INTO CENTRAL PORTIONS OF THE FORECAST AREA
TODAY AS THE 500 MB HIGH PRESSURE CENTER REPOSITIONS OVER THE TX
PANHANDLE. AN UPPER TROUGH TRACKING SOUTHEASTWARD FROM THE CENTRAL
ROCKIES ONTO THE CENTRAL AND SOUTHERN GREAT PLAINS TONIGHT AND
THURSDAY WILL THEN SHIFT THE DIRECTION OF THE WAVE...MOVING IT
EASTWARD ACROSS THE EAST CENTRAL PLAINS. ALSO...A NORTHEASTERLY
WIND SHIFT THAT DEVELOPED ACROSS NE NM TUESDAY AS THE UPPER HIGH
BEGAN MIGRATING TOWARD THE TX PANHANDLE FROM UT WILL PUSH THROUGH
CENTRAL PARTS OF THE STATE TODAY WITH A MODESTLY GUSTY EAST CANYON
WIND AND INCREASED MOISTURE. THE NET RESULT WILL BE INCREASING
COVERAGE OF THUNDERSTORMS WITH HEAVY RAIN ACROSS WESTERN...CENTRAL
AND NE AREAS TODAY...TONIGHT AND THURSDAY. THOUGH THUNDERSTORMS WILL
LIKELY BE SPOTTIER ACROSS SE AREAS...THE STORMS THAT DO DEVELOP WILL
CERTAINLY BE CAPABLE OF PRODUCING HEAVY RAINFALL. THE WETTEST
PERIOD OF THIS MONSOON BURST WILL LIKELY BE TONIGHT WHEN
PRECIPITABLE WATER VALUES ARE FORECAST TO VARY FROM 1 TO 1.5 INCHES
ACROSS THE AREA. IN THE WAKE OF THE UPPER TROUGH CLIPPING NE NM
FROM THE NW...PRECIPITABLE WATER VALUES SHOULD DROP TO AROUND THREE
QUARTERS OF AN INCH ACROSS N CENTRAL AND NW AREAS THURSDAY...WHILE
REMAINING RELATIVELY HIGH ELSEWHERE. TEMPERATURES TODAY AND
THURSDAY WILL VARY FROM NEAR NORMAL TO AS MUCH AS 6 DEGREES BELOW
NORMAL.
BY FRIDAY A WEAK UPPER HIGH WILL REFORM VAGUELY OVER AZ AND NM AS THE
UPPER TROUGH EXITING THE CENTRAL ROCKIES DIVES SOUTHEASTWARD INTO
THE SOUTHERN GREAT PLAINS. HOWEVER...THE MONSOON MOISTURE PLUME WILL
REMAIN TRAPPED UNDER THE RIDGE ALOFT AND SQUARELY OVER NM FRIDAY
THROUGH THE WEEKEND. THE UPPER TROUGH WILL SEND A SECOND BACK DOOR
COLD FRONT INTO THE EAST THURSDAY NIGHT AND FRIDAY. CURRENT THINKING
IS THAT THIS FRONT COULD STABILIZE THINGS A BIT ACROSS THE NORTHEAST
ON FRIDAY...BUT IT COULD HELP TRIGGER CONVECTION IN CENTRAL AREAS
AND POSSIBLY ALSO WESTERN AREAS IF IT MAKES IT THAT FAR. THUS...THE
WET WEATHER THAT BEGINS WEDNESDAY SHOULD CONTINUE FRIDAY THROUGH THE
WEEKEND...ESPECIALLY CENTRAL AND WEST...THOUGH STORMS WILL SHIFT
THEIR DIRECTION OF MOTION AS THE UPPER HIGH CENTER WOBBLES AROUND
THE FORECAST AREA. HIGH TEMPERATURES THROUGH THE WEEKEND SHOULD
REMAIN A LITTLE COOLER THAN NORMAL.
GFS AND ECMWF NOW DEPICT THE 500 MB RIDGE DECREASING IN AMPLITUDE
AND STRETCHING FROM CENTRAL NM TO W TX AS A STRONG OF TROUGHS IN THE
WESTERLIES CROSS THE CENTRAL ROCKIES. INTERESTINGLY...MODELS KEEP
THE MONSOON MOISTURE PLUME OVER THE FORECAST AREA...THOUGH IT MAY
TILT FROM THE SW TO NE QUADRANTS. THUS...DAILY ROUNDS OF SCATTERED
TO ISOLATED AND AT TIMES NUMEROUS STORMS WILL CONTINUE. SPOTTIER
CONVECTION MAY BE FOUND ACROSS NW AREAS WHERE SOME DRIER AIR COULD
ARRIVE IN THE WAKE OF SOME OF THE UPPER TROUGHS. TEMPERATURES SHOULD
REMAIN NEAR AND A LITTLE BELOW NORMAL.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY MORNING FOR THE FOLLOWING
ZONES...NMZ501>533-539-540.
&&
$$
01
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
606 AM MDT WED JUL 24 2013
.AVIATION...
12Z TAF CYCLE
MONSOON BURST EXPECTED TODAY AND THURSDAY AS A DEEP MONSOON
MOISTURE PLUME TRACKS N AND NE ACROSS THE FORECAST AREA WITH
AN EMBEDDED SUBTROPICAL PERTURBATION OR TWO. THE HRRR MODEL PROGS A
WAVE OF -SHRA AND EMBEDDED TS TRACKING NORTHWARD ACROSS W AND
CENTRAL NM TODAY...REACHING ABQ IN EARLY AFTN AND SAF BY LATE
AFTN. AN UPPER TROUGH IS EXPECTED TO BRUSH NORTHERN PARTS OF THE
STATE AS IT TRACKS E ACROSS CO TONIGHT. THIS SHOULD INVIGORATE TS
ALONG THE CENTRAL MT CHAIN THIS EVENING AND SEND A CLUSTER OR LINE
OF STORMS E ACROSS THE E CENTRAL AND NE PLAINS OVERNIGHT.
MEANWHILE...ECMWF AND GFS SUGGEST A SLOW MOVING SUBTROPICAL
PERTURBATION COULD LINGER OVER CENTRAL PARTS OF THE STATE TONIGHT
KEEPING SHOWERS AND POSSIBLY AN AREA OF STRATIFORM RAIN ACTIVE.
STRONGER STORMS TODAY THRU THURSDAY WILL BE CAPABLE OF PRODUCING WET
MICROBURSTS WITH VERY HEAVY RAIN AND BRIEF PERIODS OF IFR
CONDITIONS WITH MT OBSCURATIONS...ERRATIC WIND GUSTS OVER 45
KT AND FREQUENT/DANGEROUS LIGHTNING.
44
&&
.PREV DISCUSSION...308 AM MDT WED JUL 24 2013...
THE AXIS OF MOIST INSTABILITY IS CENTERED SMACK DAB OVER NM THIS
MORNING. LATEST WATER VAPOR LOOP SHOWS THE MONSOON PLUME FROM SOUTH
TO NORTH WITH A PERTURBATION WASHING OUT ACROSS SOUTHERN NM. PWAT
VALUES ARE IMPRESSIVE PER CIRA IMAGERY AND REGIONAL SOUNDINGS. THE
GEFS AND SREF SOLUTIONS INDICATE THE 594DM H5 HIGH WILL SHIFT EAST
INTO WEST TX TODAY AND ALLOW A RATHER WELL DEFINED PERTURBATION TO
SLIDE NORTH INTO CENTRAL NM. PWAT VALUES ARE PROGGED TO AVERAGE THE
1.2-1.4 RANGE ALONG AND SOUTH OF I-40 BY THIS EVENING...WHICH IS
WELL WITHIN FLASH FLOOD TERRITORY. DEEP MOIST SSE ATMOSPHERIC FLOW
ALONG WITH A WEAK BOUNDARY SHIFTING SW OVER THE EASTERN PLAINS WILL
SET THE STAGE FOR SOME TRAINING CELLS. A GLIMPSE OF THE 05Z HRRR
SOLUTION SHOWS WIDESPREAD STORMS DEVELOPING FROM SOUTH TO NORTH
TODAY. WILL HOIST A FLASH FLOOD WATCH FOR POTENTIAL RAIN RATES NEAR
2 INCHES PER HOUR. STORM MOTIONS WILL AVERAGE ABOUT 15-20 KNOTS
HOWEVER CELL TRAINING MAY LEAD TO FLASH FLOODING...ESPECIALLY OVER
BURN SCARS.
BY THURSDAY THE UPPER HIGH REDEVELOPS OVER ARIZONA WITH LIGHT TO
MODERATE NW FLOW DEVELOPING ALOFT OVER NM. THIS WILL SHIFT THE
THETA-E RIDGE AXIS IN A SW-NE ORIENTATION...ALLOWING FOR MORE
WIDESPREAD ACTIVITY TO SLIDE INTO THE EASTERN PLAINS DURING THE
LATE AFTERNOON AND EVENING HOURS. ANOTHER FRONTAL BOUNDARY WILL
SHIFT DOWN THE PLAINS THURSDAY NIGHT AND FRIDAY FOCUSING MORE
HEAVY RAINFALL ALONG AND EAST OF THE CENTRAL MT CHAIN. PWAT VALUES
ARE PROGGED TO FALL BELOW 1.2 FOR MOST OF THE AREA SO FLASH FLOOD
THREAT MAY NOT BE AS HIGH...BUT WILL REVISIT AGAIN LATER TODAY.
THE FRIDAY/SATURDAY PERIOD WILL FEATURE MOISTURE RECYCLING OVER
WESTERN NM AS THE H5 HIGH SHIFTS BACK OVER CENTRAL/EASTERN NM.
STORM MOTIONS WILL BECOME VERY WEAK WITH LOCALLY HEAVY RAINFALL
OVER SMALLER FOOTPRINTS.
POTENTIAL IS INCREASING THAT AN EXTENDED TRUE MONSOONAL BURST PATTERN
WILL SET UP BY EARLY NEXT WEEK AS THE 700-500MB HIGH CENTROID SHIFTS
INTO TX. THIS WILL OPEN THE DOOR TO DEEP SUBTROPICAL AND MORE HEAVY
RAINFALL OVER NM. CLIMATOLOGICALLY WE ARE NOW IN THE MOST FLASHY
PERIOD OF THE MONSOON SO WILL JUST CONTINUE TO TREND POPS UP INTO
THE EXTENDED AS MODEL CONSISTENCY CONTINUES.
GUYER
.FIRE WEATHER...
A WAVE OF SUBTROPICAL ORIGIN THAT HAS BEEN STATIONARY IN THE
VICINITY OF EL PASO AND THE NM BOOTHEEL THE PAST COUPLE DAYS WILL
FINALLY SHIFT NORTHWARD INTO CENTRAL PORTIONS OF THE FORECAST AREA
TODAY AS THE 500 MB HIGH PRESSURE CENTER REPOSITIONS OVER THE TX
PANHANDLE. AN UPPER TROUGH TRACKING SOUTHEASTWARD FROM THE CENTRAL
ROCKIES ONTO THE CENTRAL AND SOUTHERN GREAT PLAINS TONIGHT AND
THURSDAY WILL THEN SHIFT THE DIRECTION OF THE WAVE...MOVING IT
EASTWARD ACROSS THE EAST CENTRAL PLAINS. ALSO...A NORTHEASTERLY
WIND SHIFT THAT DEVELOPED ACROSS NE NM TUESDAY AS THE UPPER HIGH
BEGAN MIGRATING TOWARD THE TX PANHANDLE FROM UT WILL PUSH THROUGH
CENTRAL PARTS OF THE STATE TODAY WITH A MODESTLY GUSTY EAST CANYON
WIND AND INCREASED MOISTURE. THE NET RESULT WILL BE INCREASING
COVERAGE OF THUNDERSTORMS WITH HEAVY RAIN ACROSS WESTERN...CENTRAL
AND NE AREAS TODAY...TONIGHT AND THURSDAY. THOUGH THUNDERSTORMS WILL
LIKELY BE SPOTTIER ACROSS SE AREAS...THE STORMS THAT DO DEVELOP WILL
CERTAINLY BE CAPABLE OF PRODUCING HEAVY RAINFALL. THE WETTEST
PERIOD OF THIS MONSOON BURST WILL LIKELY BE TONIGHT WHEN
PRECIPITABLE WATER VALUES ARE FORECAST TO VARY FROM 1 TO 1.5 INCHES
ACROSS THE AREA. IN THE WAKE OF THE UPPER TROUGH CLIPPING NE NM
FROM THE NW...PRECIPITABLE WATER VALUES SHOULD DROP TO AROUND THREE
QUARTERS OF AN INCH ACROSS N CENTRAL AND NW AREAS THURSDAY...WHILE
REMAINING RELATIVELY HIGH ELSEWHERE. TEMPERATURES TODAY AND
THURSDAY WILL VARY FROM NEAR NORMAL TO AS MUCH AS 6 DEGREES BELOW
NORMAL.
BY FRIDAY A WEAK UPPER HIGH WILL REFORM VAGUELY OVER AZ AND NM AS THE
UPPER TROUGH EXITING THE CENTRAL ROCKIES DIVES SOUTHEASTWARD INTO
THE SOUTHERN GREAT PLAINS. HOWEVER...THE MONSOON MOISTURE PLUME WILL
REMAIN TRAPPED UNDER THE RIDGE ALOFT AND SQUARELY OVER NM FRIDAY
THROUGH THE WEEKEND. THE UPPER TROUGH WILL SEND A SECOND BACK DOOR
COLD FRONT INTO THE EAST THURSDAY NIGHT AND FRIDAY. CURRENT THINKING
IS THAT THIS FRONT COULD STABILIZE THINGS A BIT ACROSS THE NORTHEAST
ON FRIDAY...BUT IT COULD HELP TRIGGER CONVECTION IN CENTRAL AREAS
AND POSSIBLY ALSO WESTERN AREAS IF IT MAKES IT THAT FAR. THUS...THE
WET WEATHER THAT BEGINS WEDNESDAY SHOULD CONTINUE FRIDAY THROUGH THE
WEEKEND...ESPECIALLY CENTRAL AND WEST...THOUGH STORMS WILL SHIFT
THEIR DIRECTION OF MOTION AS THE UPPER HIGH CENTER WOBBLES AROUND
THE FORECAST AREA. HIGH TEMPERATURES THROUGH THE WEEKEND SHOULD
REMAIN A LITTLE COOLER THAN NORMAL.
GFS AND ECMWF NOW DEPICT THE 500 MB RIDGE DECREASING IN AMPLITUDE
AND STRETCHING FROM CENTRAL NM TO W TX AS A STRONG OF TROUGHS IN THE
WESTERLIES CROSS THE CENTRAL ROCKIES. INTERESTINGLY...MODELS KEEP
THE MONSOON MOISTURE PLUME OVER THE FORECAST AREA...THOUGH IT MAY
TILT FROM THE SW TO NE QUADRANTS. THUS...DAILY ROUNDS OF SCATTERED
TO ISOLATED AND AT TIMES NUMEROUS STORMS WILL CONTINUE. SPOTTIER
CONVECTION MAY BE FOUND ACROSS NW AREAS WHERE SOME DRIER AIR COULD
ARRIVE IN THE WAKE OF SOME OF THE UPPER TROUGHS. TEMPERATURES SHOULD
REMAIN NEAR AND A LITTLE BELOW NORMAL.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 11 AM MDT THIS MORNING THROUGH THIS EVENING
FOR THE FOLLOWING ZONES...NMZ501>529-539-540.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
730 PM EDT THU JUL 25 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE ACROSS THE NORTH COUNTRY THROUGH
FRIDAY...AS LOW PRESSURE MOVES TOWARD CAPE COD. THIS WILL INCREASE
CLOUDS ACROSS PARTS OF OUR REGION...WITH A CHANCE OF SHOWERS
POSSIBLE FOR EASTERN VERMONT THROUGH FRIDAY. A STRONGER SYSTEM AND
ASSOCIATED FRONT WILL PRODUCE A PERIOD OF SHOWERS WITH EMBEDDED
STORMS ON SUNDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL
THROUGH FRIDAY...BEFORE RETURNING CLOSE TO NORMAL OVER THE
WEEKEND...WITH SOME INCREASE IN HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
AS OF 730 PM EDT THURSDAY...MINOR ADJUSTMENTS TO SKY COVER AND T/TD
DATASETS AS WE HEAD INTO THE EVENING HOURS PER LATEST
OBSERVATIONAL DATA. CURRENT FORECAST IN GOOD SHAPE FOW NOW SO NO
LARGE SCALE CHANGES NEEDED. STILL MONITORING SLOW NORTHWARD
ADVANCE OF FRONTOGENETICALLY FORCED BAND OF SHOWERS ACROSS
SOUTHERN/EASTERN NEW ENGLAND...WHICH MAY MAKE INROADS INTO FAR
SOUTHERN/EASTERN VT LATER THIS EVENING. HOWEVER...OUTSIDE SOME
THICKENING MID TO HIGH CLOUDS IN THESE AREAS A GENERALLY QUIET
EVENING EXPECTED WITH MAINLY CLEAR SKIES AND SLACKENING WINDS.
PRIOR DISCUSSION FOLLOWS...
WATER VAPOR SHOWS MID/UPPER LVL TROF ACRS THE EASTERN CONUS WHILE
POTENT S/W ENERGY AND DEEP TROPICAL MOISTURE IS LOCATED OFF THE
MID ATLANTIC COAST. THIS ENERGY WL HELP IN THE DEVELOPMENT OF SFC
LOW PRES TONIGHT...WHICH WL TRACK TWD CAPE COD BY FRIDAY. LATEST
12Z GUIDANCE SHOWS A SLIGHT WESTWARD TRACK AND PLACEMENT OF
QPF...BUT STILL MAINLY EAST OF OUR CWA. LATEST HRRR REFLECTIVITY
AND QPF PROGS SHOW LIGHT RAIN SHOWERS IMPACTING ORANGE AND WINDSOR
COUNTIES AFT 04Z TONIGHT. WL MENTION CHC POPS ACRS THIS REGION.
NAM/GFS SHOW A CLOSED 7H CIRCULATION OVER SNE...WITH SFC LOW PRES
OVER CAPE COD AT 18Z FRIDAY...AS BEST 850 TO 500MB RH AND UVVS
FIELDS ARE JUST EAST OF OUR CWA. BOTH MODELS ALONG WITH THE ECMWF
SHOW A SHARP WEST TO EAST GRADIENT IN RH AND QPF FIELDS...THRU
FRIDAY. WL CONT TO MENTION SCHC TO LOW CHC POPS ACRS EASTERN VT.
THINKING MOST PRECIP WL EVAPORATE BEFORE REACHING THE GROUND...PER
DEPTH OF DRY LAYER ON SOUNDINGS. TEMPS WL BE TRICKY
TONIGHT...BASED ON CLOUDS...THINKING U30S SLK TO M50S VSF.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 410 PM EDT THURSDAY...PROGRESSIVE FLW ALOFT WL QUICKLY LIFT S/W
ENERGY AND DEEPER MOISTURE NORTHEAST ALONG THE EASTERN SEABOARD
ON FRIDAY. ONCE AGAIN ANTICIPATE A SHARP WEST TO EAST GRADIENT IN
RH FIELDS...WITH MAYBE A BRIEF SHOWER ACRS EXTREME EASTERN VT. WL
CONT TO MENTION SCHC POPS. PROGGED 85H TEMPS WARM ANOTHER 2 TO 3C
FROM THURS...TO SUPPORT NEAR NORMAL HIGHS IN THE 70S MTNS TO L/M
80S VALLEYS. WARMEST TEMPS WL BE ACRS THE SLV...WHERE SKIES WL BE
SUNNY.
FRIDAY NIGHT THRU SATURDAY NIGHT...DEEP CLOSED AND NEARLY VERTICAL
STACKED SYSTEM ACRS THE CENTRAL GREAT LAKES WL SLOWLY APPROACH THE
NE CONUS. THE MID/UPPER LVL FLW AHEAD OF THIS SYSTEM WL BECM
SOUTHERLY WITH SEVERAL EMBEDDED S/W`S...ESPECIALLY SAT AFTN/EVENING.
IN ADDITION...LATEST 12Z GFS SHOWS SEVERAL RIBBONS OF ENHANCED 850
TO 500MB RH ADVECTING FROM SOUTH TO NORTH ACRS OUR FA...IN THE
SOUTHERLY FLW ALOFT. HOWEVER...BEST LLVL SFC CONVERGENCE ASSOCIATED
WITH FRNT AND LOW PRES...ALONG WITH STRONGEST JET WINDS WL STAY WEST
OF OUR CWA THRU 12Z SUNDAY. INSTABILITY LOOKS LIMITED ON SAT ACRS
OUR CWA...AS NAM/GFS SHOW BEST PARAMETERS SOUTH OF OUR
FA...ASSOCIATED WITH HIGHER BL DWPTS. WL MENTION CHC POPS AFT 18Z
SATURDAY...ASSOCIATED WITH LOW/MID LVL WAA AND MOISTURE ADVECTION
ACRS OUR FA. QPF WL BE LIGHT WITH MAINLY SPRINKLES/VIRGA OCCURRING
INITIALLY. PROGGED 85H TEMPS BTWN 13 AND 15C...SUPPORT HIGHS BACK
INTO THE U70S MTNS TO M80S WARMER VALLEYS. IN ADDITION...HUMIDITY
LVLS WL CONT TO INCREASE...ESPECIALLY BY SAT NIGHT...ASSOCIATED WITH
SOUTHERLY FLW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 410 PM EDT THURSDAY...UPPER TROUGH OVER THE EASTERN GREAT
LAKES WILL BE SLOW TO MOVE EAST THROUGH THE FIRST HALF OF THE
EXTENDED PERIOD...SUNDAY THROUGH TUESDAY. AS A RESULT...DYNAMIC
SUPPORT WILL PLAY A FACTOR IN INCREASING PRECIPITATION CHANCES ON
SUNDAY WITH LIKELY TO CATEGORICAL PRECIPITATION CHANCES EXPECTED.
AFTER SUNDAY...THE AREA GETS IN THE DRY SLOT BEHIND THE COLD
FRONT...BUT STEEPENING LAPSE RATES DUE TO COLD AIR ADVECTION ALOFT
SUGGESTS THE POTENTIAL FOR DIURNALLY DRIVEN SHOWERS ON MONDAY AND
ESPECIALLY ON TUESDAY. WILL THEREFORE GO AHEAD AND ADD A CHANCE OF
SHOWERS TO MONDAY AND TUESDAY. WITH CLOUDS AND SHOWERS LINGERING
AROUND...LOOKING AT TEMPERATURES ABOUT 2 TO 4 DEGREES BELOW
NORMAL. WESTERLY FLOW DEVELOPS WEDNESDAY AND THURSDAY...SO DRIER
WEATHER IS EXPECTED ALONG WITH TEMPERATURES RIGHT AROUND SEASONAL
NORMALS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
THROUGH 00Z SATURDAY...ASIDE FROM DEVELOPING FOG TONIGHT AT SLK
EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD. CROSSOVER
TEMPS IN THE LOW/MID 40S...CLEAR SKIES AND LIGHT WINDS SHOULD
ALLOW FOR FOG TO DEVELOP TONIGHT AT SLK. THINK FOG/MIST POTENTIAL
AT MPV IS LOWER GIVEN GREATER COVERAGE OF MID/HIGH CLOUDS AND
LIGHT NORTHERLY COMPONENT TO THE WINDS. CLOUD COVER WILL TEND TO
BE LOWEST/THICKEST WITH EASTWARD AND SOUTHERN EXTENT BUT SHOULD
STILL BE VFR THROUGH THE ENTIRE PERIOD. RAIN SHIELD NOW ACROSS
CENTRAL/EASTERN NEW ENGLAND WILL SLOWLY DRIFT WESTWARD TOWARD MPV
DURING THE DAY TOMORROW BUT THAT MAY BE THE WESTERN EXTENT OF THE
RAIN SHIELD. HAVEN`T INDICATED SHOWERS AT MPV BUT IF ANY WERE TO
DEVELOP IT LIKELY WOULN`T RESULT IN SIGNIFICANT VISIBILITY
REDUCTIONS. WINDS WILL BE NORTHEAST DURING THE DAY TOMORROW
EVENTUALLY BACKING TO NORTHWEST WITH APPROACH AND PASSAGE OF
DISTANT COASTAL LOW.
OUTLOOK 00Z SATURDAY THROUGH TUESDAY...
00Z SATURDAY THROUGH 12Z SUNDAY...VFR UNDER A BUILDING RIDGE OF
HIGH PRESSURE.
12Z SUNDAY THROUGH TUESDAY...MAINLY VFR WITH PERIODS OF MVFR/IFR LIKELY
IN SHOWERS AND POSSIBLE TSRA AS A COLD FRONT TRACKS THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...JMG/TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
713 PM EDT THU JUL 25 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE ACROSS THE NORTH COUNTRY THROUGH
FRIDAY...AS LOW PRESSURE MOVES TOWARD CAPE COD. THIS WILL INCREASE
CLOUDS ACROSS PARTS OF OUR REGION...WITH A CHANCE OF SHOWERS
POSSIBLE FOR EASTERN VERMONT THROUGH FRIDAY. A STRONGER SYSTEM AND
ASSOCIATED FRONT WILL PRODUCE A PERIOD OF SHOWERS WITH EMBEDDED
STORMS ON SUNDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL
THROUGH FRIDAY...BEFORE RETURNING CLOSE TO NORMAL OVER THE
WEEKEND...WITH SOME INCREASE IN HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
AS OF 410 PM EDT THURSDAY...WATER VAPOR SHOWS MID/UPPER LVL TROF ACRS
THE EASTERN CONUS WHILE POTENT S/W ENERGY AND DEEP TROPICAL
MOISTURE IS LOCATED OFF THE MID ATLANTIC COAST. THIS ENERGY WL
HELP IN THE DEVELOPMENT OF SFC LOW PRES TONIGHT...WHICH WL TRACK
TWD CAPE COD BY FRIDAY. LATEST 12Z GUIDANCE SHOWS A SLIGHT
WESTWARD TRACK AND PLACEMENT OF QPF...BUT STILL MAINLY EAST OF OUR
CWA. LATEST HRRR REFLECTIVITY AND QPF PROGS SHOW LIGHT RAIN
SHOWERS IMPACTING ORANGE AND WINDSOR COUNTIES AFT 04Z TONIGHT. WL
MENTION CHC POPS ACRS THIS REGION. NAM/GFS SHOW A CLOSED 7H
CIRCULATION OVER SNE...WITH SFC LOW PRES OVER CAPE COD AT 18Z
FRIDAY...AS BEST 850 TO 500MB RH AND UVVS FIELDS ARE JUST EAST OF
OUR CWA. BOTH MODELS ALONG WITH THE ECMWF SHOW A SHARP WEST TO
EAST GRADIENT IN RH AND QPF FIELDS...THRU FRIDAY. WL CONT TO
MENTION SCHC TO LOW CHC POPS ACRS EASTERN VT. THINKING MOST PRECIP
WL EVAPORATE BEFORE REACHING THE GROUND...PER DEPTH OF DRY LAYER
ON SOUNDINGS. TEMPS WL BE TRICKY TONIGHT...BASED ON
CLOUDS...THINKING U30S SLK TO M50S VSF.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 410 PM EDT THURSDAY...PROGRESSIVE FLW ALOFT WL QUICKLY LIFT S/W
ENERGY AND DEEPER MOISTURE NORTHEAST ALONG THE EASTERN SEABOARD
ON FRIDAY. ONCE AGAIN ANTICIPATE A SHARP WEST TO EAST GRADIENT IN
RH FIELDS...WITH MAYBE A BRIEF SHOWER ACRS EXTREME EASTERN VT. WL
CONT TO MENTION SCHC POPS. PROGGED 85H TEMPS WARM ANOTHER 2 TO 3C
FROM THURS...TO SUPPORT NEAR NORMAL HIGHS IN THE 70S MTNS TO L/M
80S VALLEYS. WARMEST TEMPS WL BE ACRS THE SLV...WHERE SKIES WL BE
SUNNY.
FRIDAY NIGHT THRU SATURDAY NIGHT...DEEP CLOSED AND NEARLY VERTICAL
STACKED SYSTEM ACRS THE CENTRAL GREAT LAKES WL SLOWLY APPROACH THE
NE CONUS. THE MID/UPPER LVL FLW AHEAD OF THIS SYSTEM WL BECM
SOUTHERLY WITH SEVERAL EMBEDDED S/W`S...ESPECIALLY SAT AFTN/EVENING.
IN ADDITION...LATEST 12Z GFS SHOWS SEVERAL RIBBONS OF ENHANCED 850
TO 500MB RH ADVECTING FROM SOUTH TO NORTH ACRS OUR FA...IN THE
SOUTHERLY FLW ALOFT. HOWEVER...BEST LLVL SFC CONVERGENCE ASSOCIATED
WITH FRNT AND LOW PRES...ALONG WITH STRONGEST JET WINDS WL STAY WEST
OF OUR CWA THRU 12Z SUNDAY. INSTABILITY LOOKS LIMITED ON SAT ACRS
OUR CWA...AS NAM/GFS SHOW BEST PARAMETERS SOUTH OF OUR
FA...ASSOCIATED WITH HIGHER BL DWPTS. WL MENTION CHC POPS AFT 18Z
SATURDAY...ASSOCIATED WITH LOW/MID LVL WAA AND MOISTURE ADVECTION
ACRS OUR FA. QPF WL BE LIGHT WITH MAINLY SPRINKLES/VIRGA OCCURRING
INITIALLY. PROGGED 85H TEMPS BTWN 13 AND 15C...SUPPORT HIGHS BACK
INTO THE U70S MTNS TO M80S WARMER VALLEYS. IN ADDITION...HUMIDITY
LVLS WL CONT TO INCREASE...ESPECIALLY BY SAT NIGHT...ASSOCIATED WITH
SOUTHERLY FLW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 410 PM EDT THURSDAY...UPPER TROUGH OVER THE EASTERN GREAT
LAKES WILL BE SLOW TO MOVE EAST THROUGH THE FIRST HALF OF THE
EXTENDED PERIOD...SUNDAY THROUGH TUESDAY. AS A RESULT...DYNAMIC
SUPPORT WILL PLAY A FACTOR IN INCREASING PRECIPITATION CHANCES ON
SUNDAY WITH LIKELY TO CATEGORICAL PRECIPITATION CHANCES EXPECTED.
AFTER SUNDAY...THE AREA GETS IN THE DRY SLOT BEHIND THE COLD
FRONT...BUT STEEPENING LAPSE RATES DUE TO COLD AIR ADVECTION ALOFT
SUGGESTS THE POTENTIAL FOR DIURNALLY DRIVEN SHOWERS ON MONDAY AND
ESPECIALLY ON TUESDAY. WILL THEREFORE GO AHEAD AND ADD A CHANCE OF
SHOWERS TO MONDAY AND TUESDAY. WITH CLOUDS AND SHOWERS LINGERING
AROUND...LOOKING AT TEMPERATURES ABOUT 2 TO 4 DEGREES BELOW
NORMAL. WESTERLY FLOW DEVELOPS WEDNESDAY AND THURSDAY...SO DRIER
WEATHER IS EXPECTED ALONG WITH TEMPERATURES RIGHT AROUND SEASONAL
NORMALS.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
THROUGH 00Z SATURDAY...ASIDE FROM DEVELOPING FOG TONIGHT AT SLK
EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD. CROSSOVER
TEMPS IN THE LOW/MID 40S...CLEAR SKIES AND LIGHT WINDS SHOULD
ALLOW FOR FOG TO DEVELOP TONIGHT AT SLK. THINK FOG/MIST POTENTIAL
AT MPV IS LOWER GIVEN GREATER COVERAGE OF MID/HIGH CLOUDS AND
LIGHT NORTHERLY COMPONENT TO THE WINDS. CLOUD COVER WILL TEND TO
BE LOWEST/THICKEST WITH EASTWARD AND SOUTHERN EXTENT BUT SHOULD
STILL BE VFR THROUGH THE ENTIRE PERIOD. RAIN SHIELD NOW ACROSS
CENTRAL/EASTERN NEW ENGLAND WILL SLOWLY DRIFT WESTWARD TOWARD MPV
DURING THE DAY TOMORROW BUT THAT MAY BE THE WESTERN EXTENT OF THE
RAIN SHIELD. HAVEN`T INDICATED SHOWERS AT MPV BUT IF ANY WERE TO
DEVELOP IT LIKELY WOULN`T RESULT IN SIGNIFICANT VISIBILITY
REDUCTIONS. WINDS WILL BE NORTHEAST DURING THE DAY TOMORROW
EVENTUALLY BACKING TO NORTHWEST WITH APPROACH AND PASSAGE OF
DISTANT COASTAL LOW.
OUTLOOK 00Z SATURDAY THROUGH TUESDAY...
00Z SATURDAY THROUGH 12Z SUNDAY...VFR UNDER A BUILDING RIDGE OF
HIGH PRESSURE.
12Z SUNDAY THROUGH TUESDAY...MAINLY VFR WITH PERIODS OF MVFR/IFR LIKELY
IN SHOWERS AND POSSIBLE TSRA AS A COLD FRONT TRACKS THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LOCONTO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
413 PM EDT WED JUL 24 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD EASTWARD INTO THE REGION TONIGHT INTO
THURSDAY WITH DRY AND SEASONABLY COOL WEATHER EXPECTED. A SERIES OF
LOW PRESSURE SYSTEMS PASSING ALONG THE NEW ENGLAND COAST MAY SPREAD
A SOME CLOUDS AND AN OUTSIDE CHANCE OF A FEW SHOWERS TO FAR EASTERN
AREAS FRIDAY...BUT MAINLY DRY WEATHER AND SLIGHTLY WARMER
TEMPERATURES ARE EXPECTED FOR MOST OF THE AREA. AN UNSETTLED PATTERN
THEN DEVELOPS ACROSS NORTHERN NEW YORK ON SATURDAY...AND ACROSS THE
ENTIRE REGION BY SUNDAY INTO MONDAY AS ADDITIONAL FRONTAL ENERGY
PROGRESSES EAST FROM THE GREAT LAKES STATES.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 345 PM EDT WEDNESDAY...QUIET NIGHT TONIGHT AS COOL CANADIAN
HIGH PRESSURE SLOWLY BUILDS INTO THE REGION. WITH LOSS OF
INSOLATION...STRATOCUMULUS CLOUD FIELD SHOULD SLOWLY DISSIPATE
OVER TIME AND OUTSIDE SOME HIGH CLOUD COVER POSSIBLE EAST MOSTLY
CLEAR CONDITIONS ARE EXPECTED ACROSS OUR AREA LATER TONIGHT. LOWS
CLOSE TO BLENDED MOS VALUES (40S TO AROUND 50) THOUGH WITH
CUSTOMARY VARIABILITY...ESPECIALLY ALONG LAKE CHAMPLAIN WHERE
WATER TEMPERATURES REMAIN AROUND 70F. PATCHY FOG ALSO POSSIBLE
HERE AND THERE...BUT MOST FAVORABLE ACROSS NORTHERN NEW YORK WHERE
WINDS ATOP THE NOCTURNAL BOUNDARY LAYER WILL BE THE LIGHTEST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 345 PM EDT WEDNESDAY...MAINLY NICE WEATHER THEN CONTINUES FOR
THE REMAINDER OF THE SHORT TERM AS AFOREMENTIONED HIGH PRESSURE
BUILDS ACROSS OUR AREA. THE SURFACE FRONT THAT CROSSED OUR AREA
THIS MORNING WILL STALL ALONG OR JUST OFFSHORE THE NEW ENGLAND
COAST DURING THIS PERIOD...AND THERE WILL BE A SERIES OF LOW
PRESSURE WAVES THAT WILL RIDE NORTHEAST ALONG THE BOUNDARY.
HOWEVER...OUTSIDE THE WESTERN OUTLIER SOLUTION OF THIS MORNING`S
NAM...GLOBAL MODELS REMAIN FAIRLY CONSISTENT IN SHOWING DEEPER
MOISTURE AND THREAT OF RAINFALL REMAINING GENERALLY EAST OF OUR
AREA. THUS I`LL CONTINUE TO LEAN IN THIS DIRECTION SUGGESTING
MAINLY DRY WEATHER AND ONLY SOME CLOUDS AND PERHAPS AN OUTSIDE
SHOT AT A SHOWER OR TWO ACROSS OUR FAR EASTERN COUNTIES BY FRIDAY.
HIGHS SLOWLY MODERATE INTO THE 70S BY TOMORROW...AND 75 TO 82 BY
FRIDAY WITH COOLEST READINGS EAST WITH HIGHER DEGREE OF CLOUD
COVER. LOWS IN THE 40S TO LOWER 50S THURSDAY NIGHT...THEN MILDER
IN THE 50S TO AROUND 60 BY FRIDAY NIGHT AS FLOW TRENDS LIGHT
SOUTHERLY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 410 PM EDT WEDNESDAY...LITTLE CHANGE IN OVERALL THINKING FOR
PERIODS 4 THRU 7...WITH FCST FOCUS ON TIMING OF PRECIP SUNDAY INTO
MONDAY. MODELS IN GOOD AGREEMENT WITH LARGE SCALE SYNOPTIC
FEATURES...BUT STILL HAVING TIMING ISSUES ASSOCIATED WITH FRONT
AND RIBBON OF ENHANCED RH ON SUNDAY. LATEST TRENDS HAVE BEEN FOR A
DEEPER/MORE AMPLIFIED SYSTEM ACRS THE CENTRAL GREAT LAKES AND
FRNT/RH PARALLELING THE MID/UPPER LVL FLOW. THIS DEEPLY CLOSED
5H/7H CIRCULATION AND BOUNDARY PARALLELING THE FLW ALOFT WOULD
RESULT IN A SLOWER ARRIVAL TIME OF PRECIP ON SUNDAY. WL MENTION
CHC POPS IN THE MORNING...THEN LIKELY FROM 18Z TO 06Z
SUNDAY/MONDAY...BEFORE TAPERING BACK TO CHC POPS AFT 06Z MONDAY.
IN ADDITION...BOTH GFS/ECMWF SHOW POTENT RRQ OF 25H JET LIFTING
FROM SOUTH TO NORTH ACRS OUR REGION...AHEAD OF DIGGING
TROF...WHICH WL HELP TO ENHANCE ULVL DIVERGENCE AND PROMOTE DEEP
LAYER LIFT LATE SUNDAY. OTHERWISE...MID/UPPER LVL TROF PREVAILS
ACRS THE NE CONUS FOR EARLY NEXT WEEK...WITH WEAK EMBEDDED VORTS.
STILL SOME UNCERTAINTY ON DEEP OF AVAILABLE MOISTURE AND TIMING OF
INDIVIDUAL S/W`S...SOME HAVE MENTIONED SCHC/LOW CHC POPS THRU
EARLY NEXT WK. PROGGED 85H TEMPS AHEAD OF BOUNDARY WARM BTWN
12-14C OVER THE WEEKEND...SUPPORTING HIGHS IN THE M70S MTNS TO L/M
80S WARMER VALLEYS. HOWEVER...AS TROF MOVES OVERHEAD THERMAL
PROFILES COOL AND TEMPS WL DROP BACK MAINLY IN THE 70S...OVERALL
VERY CLOSE TO NORMAL.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...AVIATION CHALLENGE WL BE DISSIPATION OF
STRATO CUMULUS DECK LATE THIS AFTN/EVENING...FOLLOWED BY FOG/BR
POTENTIAL. CRNT VIS SATL PIC SHOWS LOTS OF STRATO CU ACRS OUR TAF
SITES...ASSOCIATED WITH NW UPSLOPE FLW AND LLVL CAA. SOME
UNCERTAINTY TO WHEN THIS DISSIPATES...AS RAP SHOWS LLVL MOISTURE
HANGING AROUND THRU 04Z...ESPECIALLY AT MPV/SLK...WHILE GFS/NAM
SHOW RAPID DECREASE IN RH BTWN 18Z-21Z TODAY. WL USE COMPROMISE
AND SHOW MVFR CIGS IMPROVING TO VFR AT ALL TAF SITES BY EARLY THIS
EVENING. IN ADDITION...AS LLVL`S STABILIZE FROM LACK OF SFC
HEATING...EXPECT WINDS TO DECREASE AT 4 TO 8 KNTS. SOUNDINGS SHOW
BL WINDS BTWN 6 AND 12 KNOTS TONIGHT...AS SFC HIGH PRES IS ACRS
THE CENTRAL GREAT LAKES...ALONG WITH SOME LEFTOVER
CLOUDS...ESPECIALLY ACRS THE UPSLOPE TAF SITES OF MPV/SLK. THIS
MOISTURE AND WIND...MAY PREVENT WIDESPREAD FOG/BR FROM DEVELOPING.
HAVE MENTION TEMPO GROUP AT MSS/SLK BTWN 07Z-11Z. OTHERWISE...VFR
WL PREVAIL BTWN 12-18Z THURS.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
MAINLY VFR CONDITIONS WL PREVAIL THRU SUNDAY...AS WEAK SFC LOW
PRES TRACKS TWD CAPE COD ON FRIDAY...BUT BEST MOISTURE WL STILL
EAST OF OUR FA. ANOTHER SYSTEM ON SUNDAY WL PRODUCE SCATTERED
SHOWERS WITH A CHANCE OF THUNDER ACRS OUR CWA. EXPECT MAINLY VFR
BUT A BRIEF PERIOD OF MVFR IN THE STRONGER STORMS WL BE
POSSIBLE...ESPECIALLY SUNDAY AFTN.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
345 PM EDT WED JUL 24 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD EASTWARD INTO THE REGION TONIGHT INTO
THURSDAY WITH DRY AND SEASONABLY COOL WEATHER EXPECTED. A SERIES OF
LOW PRESSURE SYSTEMS PASSING ALONG THE NEW ENGLAND COAST MAY SPREAD
A SOME CLOUDS AND AN OUTSIDE CHANCE OF A FEW SHOWERS TO FAR EASTERN
AREAS FRIDAY...BUT MAINLY DRY WEATHER AND SLIGHTLY WARMER
TEMPERATURES ARE EXPECTED FOR MOST OF THE AREA. AN UNSETTLED PATTERN
THEN DEVELOPS ACROSS NORTHERN NEW YORK ON SATURDAY...AND ACROSS THE
ENTIRE REGION BY SUNDAY INTO MONDAY AS ADDITIONAL FRONTAL ENERGY
PROGRESSES EAST FROM THE GREAT LAKES STATES.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 345 PM EDT WEDNESDAY...QUIET NIGHT TONIGHT AS COOL CANADIAN
HIGH PRESSURE SLOWLY BUILDS INTO THE REGION. WITH LOSS OF
INSOLATION...STRATOCUMULUS CLOUD FIELD SHOULD SLOWLY DISSIPATE
OVER TIME AND OUTSIDE SOME HIGH CLOUD COVER POSSIBLE EAST MOSTLY
CLEAR CONDITIONS ARE EXPECTED ACROSS OUR AREA LATER TONIGHT. LOWS
CLOSE TO BLENDED MOS VALUES (40S TO AROUND 50) THOUGH WITH
CUSTOMARY VARIABILITY...ESPECIALLY ALONG LAKE CHAMPLAIN WHERE
WATER TEMPERATURES REMAIN AROUND 70F. PATCHY FOG ALSO POSSIBLE
HERE AND THERE...BUT MOST FAVORABLE ACROSS NORTHERN NEW YORK WHERE
WINDS ATOP THE NOCTURNAL BOUNDARY LAYER WILL BE THE LIGHTEST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 345 PM EDT WEDNESDAY...MAINLY NICE WEATHER THEN CONTINUES FOR
THE REMAINDER OF THE SHORT TERM AS AFOREMENTIONED HIGH PRESSURE
BUILDS ACROSS OUR AREA. THE SURFACE FRONT THAT CROSSED OUR AREA
THIS MORNING WILL STALL ALONG OR JUST OFFSHORE THE NEW ENGLAND
COAST DURING THIS PERIOD...AND THERE WILL BE A SERIES OF LOW
PRESSURE WAVES THAT WILL RIDE NORTHEAST ALONG THE BOUNDARY.
HOWEVER...OUTSIDE THE WESTERN OUTLIER SOLUTION OF THIS MORNING`S
NAM...GLOBAL MODELS REMAIN FAIRLY CONSISTENT IN SHOWING DEEPER
MOISTURE AND THREAT OF RAINFALL REMAINING GENERALLY EAST OF OUR
AREA. THUS I`LL CONTINUE TO LEAN IN THIS DIRECTION SUGGESTING
MAINLY DRY WEATHER AND ONLY SOME CLOUDS AND PERHAPS AN OUTSIDE
SHOT AT A SHOWER OR TWO ACROSS OUR FAR EASTERN COUNTIES BY FRIDAY.
HIGHS SLOWLY MODERATE INTO THE 70S BY TOMORROW...AND 75 TO 82 BY
FRIDAY WITH COOLEST READINGS EAST WITH HIGHER DEGREE OF CLOUD
COVER. LOWS IN THE 40S TO LOWER 50S THURSDAY NIGHT...THEN MILDER
IN THE 50S TO AROUND 60 BY FRIDAY NIGHT AS FLOW TRENDS LIGHT
SOUTHERLY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 408 AM EDT WEDNESDAY...GOING INTO THE WEEKEND MEDIUM RANGE
GUIDANCE REMAINS FAIRLY CONSISTENT WITH THE MAIN WEATHER FEATURE
CONTINUING TO BE A CLOSED 500MB TROUGH AND ASSOCIATED SURFACE COLD
FRONT DIGGING SOUTHWARD INTO GREAT LAKES SATURDAY...AND THEN
PROGRESSING EASTWARD THROUGH THE NORTHEAST ON SUNDAY. SOUTHWEST
FLOW AHEAD OF THIS FEATURE SHOULD KEEP THE BTV CWA DRY FOR
SATURDAY...THOUGH SEVERAL MODELS ARE NOW HINTING AT SOME SORT OF
COASTAL LOW MOVING NORTHWARD FROM THE CAROLINA COAST FRIDAY
AFTERNOON TO THE GULF OF MAIN BY SATURDAY AFTERNOON. FEEL SINCE
THE FLOW AROUND THIS FEATURE IS FAIRLY WEAK WRAP AROUND MOISTURE
SHOULD STAY EAST OF THE AREA...BUT CERTAINLY SOMETHING TO KEEP AN
EYE ON. FOR SUNDAY...COLD FRONT PUSHES THROUGH THE REGION WITH
INCREASING CONFIDENCE THAT WE`LL SEE A GOOD 6-HOUR PERIOD OF RAIN
WITH SOME MODEST QPF SUNDAY MORNING...TAPERING OFF IN THE
AFTERNOON AND EVENING HOURS.
FROM SUNDAY ONWARD LONGER RANGE GUIDANCE OF THE GFS AND ECMWF
DIFFER QUITE A BIT IN REGARDS TO THE STRENGTH AND MOVEMENT OF THE
AFOREMENTIONED UPPER LOW/TROUGH. THE GFS OFFERS A DEEPER/SLOWER CLOSED
UPPER LOW LINGERING OVER THE INTL BORDER THROUGH TUESDAY...WHILE THE
ECMWF IS MUCH MORE PROGRESSIVE PUSHING THE SYSTEM NORTH AND EAST OF
THE AREA. GFS ENSEMBLE GUIDANCE IS MORE IN LINE WITH THE ECMWF...SO
HAVE LEANED TOWARDS THE FASTER/DRIER SOLUTION FOR MONDAY ONWARDS.
TEMPS THROUGH THE PERIOD REMAIN VERY SEASONAL WITH HIGHS GENERALLY
IN THE MID 70S TO LOWER 80S...AND LOWS IN THE MID 50S TO MID 60S.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...AVIATION CHALLENGE WL BE DISSIPATION OF
STRATO CUMULUS DECK LATE THIS AFTN/EVENING...FOLLOWED BY FOG/BR
POTENTIAL. CRNT VIS SATL PIC SHOWS LOTS OF STRATO CU ACRS OUR TAF
SITES...ASSOCIATED WITH NW UPSLOPE FLW AND LLVL CAA. SOME
UNCERTAINTY TO WHEN THIS DISSIPATES...AS RAP SHOWS LLVL MOISTURE
HANGING AROUND THRU 04Z...ESPECIALLY AT MPV/SLK...WHILE GFS/NAM
SHOW RAPID DECREASE IN RH BTWN 18Z-21Z TODAY. WL USE COMPROMISE
AND SHOW MVFR CIGS IMPROVING TO VFR AT ALL TAF SITES BY EARLY THIS
EVENING. IN ADDITION...AS LLVL`S STABILIZE FROM LACK OF SFC
HEATING...EXPECT WINDS TO DECREASE AT 4 TO 8 KNTS. SOUNDINGS SHOW
BL WINDS BTWN 6 AND 12 KNOTS TONIGHT...AS SFC HIGH PRES IS ACRS
THE CENTRAL GREAT LAKES...ALONG WITH SOME LEFTOVER
CLOUDS...ESPECIALLY ACRS THE UPSLOPE TAF SITES OF MPV/SLK. THIS
MOISTURE AND WIND...MAY PREVENT WIDESPREAD FOG/BR FROM DEVELOPING.
HAVE MENTION TEMPO GROUP AT MSS/SLK BTWN 07Z-11Z. OTHERWISE...VFR
WL PREVAIL BTWN 12-18Z THURS.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
MAINLY VFR CONDITIONS WL PREVAIL THRU SUNDAY...AS WEAK SFC LOW
PRES TRACKS TWD CAPE COD ON FRIDAY...BUT BEST MOISTURE WL STILL
EAST OF OUR FA. ANOTHER SYSTEM ON SUNDAY WL PRODUCE SCATTERED
SHOWERS WITH A CHANCE OF THUNDER ACRS OUR CWA. EXPECT MAINLY VFR
BUT A BRIEF PERIOD OF MVFR IN THE STRONGER STORMS WL BE
POSSIBLE...ESPECIALLY SUNDAY AFTN.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...LAHIFF
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
129 PM EDT WED JUL 24 2013
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH VERMONT EARLY TODAY WITH SCATTERED
SHOWERS AND POSSIBLY A THUNDERSTORM. BEHIND THIS FRONT...HIGH
PRESSURE WILL USHER IN DRY WEATHER AND COOLER TEMPERATURES. HIGH
PRESSURE REMAINS OVER THE REGION THURSDAY AND FRIDAY...WITH SEASONABLY
MILD AND DRY WEATHER EXPECTED. TEMPERATURES WILL TREND WARMER BY
SATURDAY. THE NEXT CHANCE OF SIGNIFICANT RAINFALL WILL OCCUR BY
SUNDAY AS ANOTHER COLD FRONT MAKES ITS WAY EASTWARD.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 120 PM EDT WEDNESDAY...COLD POST-FRONTAL ADVECTION CONTINUES
THIS AFTERNOON UNDER MODERATELY GUSTY NORTHWEST FLOW AND SCATTERED
TO BROKEN LOW LEVEL STRATOCUMULUS CLOUDS. BASED OFF CURRENT
OBSERVATIONAL DATA OPTED TO LOWER MAX TEMPS A TAD
FURTHER...ESPECIALLY ACROSS THE HIGHER ELEVATIONS WHERE HIGHEST
DEGREE OF CLOUD COVER WILL EXIST. CURRENTLY 41F ON WHITEFACE
SUMMIT WITH A WINDCHILL OF 29F...SO TAKE A JACKET OR OTHER THERMAL
WEAR IF PLANNING A HIKE IN THE HIGHER TERRAIN THIS AFTERNOON. REST
OF FORECAST IN GREAT SHAPE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 408 AM EDT WEDNESDAY...OUTSTANDING STRETCH OF WEATHER EXPECTED
FOR THE REMAINDER OF THE SHORT TERM AS CANADIAN HIGH PRESSURE
BUILDS EASTWARD INTO THE REGION TONIGHT THROUGH THURSDAY...AND
THEN RETREATS INTO EASTERN QUEBEC FRIDAY. DRY WEATHER THROUGH THE
PERIOD...WITH MAINLY CLEAR SKIES TONIGHT THROUGH THURSDAY
NIGHT...FOLLOWED BY A BIT MORE CLOUDINESS ON FRIDAY.
TEMPERATURES WILL BE BELOW NORMAL THURSDAY WITH HIGHS MAINLY IN
THE LOWER TO MID 70S. THEY WILL RETURN TO SEASONABLE LEVELS FRIDAY
WITH VALLEY HIGHS AROUND 80. LOWS BOTH NIGHTS WILL BE QUITE
COOL...IN THE 40S TO AROUND 50. EXCEPTIONS WILL BE IN THE MOUNTAIN
VALLEYS WHERE THERE WILL BE SOME 30S...AND ALONG THE LAKE CHAMPLAIN
SHORELINE WHERE IT WILL BE MILDER DUE TO THE WARM LAKE TEMPS WHICH
ARE CURRENTLY IN THE LOWER 70S. PATCHY FOG ALSO A GOOD BET...
ESPECIALLY TONIGHT AS SOIL MOISTURE LEVELS STILL QUITE HIGH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 408 AM EDT WEDNESDAY...GOING INTO THE WEEKEND MEDIUM RANGE
GUIDANCE REMAINS FAIRLY CONSISTENT WITH THE MAIN WEATHER FEATURE
CONTINUING TO BE A CLOSED 500MB TROUGH AND ASSOCIATED SURFACE COLD
FRONT DIGGING SOUTHWARD INTO GREAT LAKES SATURDAY...AND THEN
PROGRESSING EASTWARD THROUGH THE NORTHEAST ON SUNDAY. SOUTHWEST
FLOW AHEAD OF THIS FEATURE SHOULD KEEP THE BTV CWA DRY FOR
SATURDAY...THOUGH SEVERAL MODELS ARE NOW HINTING AT SOME SORT OF
COASTAL LOW MOVING NORTHWARD FROM THE CAROLINA COAST FRIDAY
AFTERNOON TO THE GULF OF MAIN BY SATURDAY AFTERNOON. FEEL SINCE
THE FLOW AROUND THIS FEATURE IS FAIRLY WEAK WRAP AROUND MOISTURE
SHOULD STAY EAST OF THE AREA...BUT CERTAINLY SOMETHING TO KEEP AN
EYE ON. FOR SUNDAY...COLD FRONT PUSHES THROUGH THE REGION WITH
INCREASING CONFIDENCE THAT WE`LL SEE A GOOD 6-HOUR PERIOD OF RAIN
WITH SOME MODEST QPF SUNDAY MORNING...TAPERING OFF IN THE
AFTERNOON AND EVENING HOURS.
FROM SUNDAY ONWARD LONGER RANGE GUIDANCE OF THE GFS AND ECMWF
DIFFER QUITE A BIT IN REGARDS TO THE STRENGTH AND MOVEMENT OF THE
AFOREMENTIONED UPPER LOW/TROUGH. THE GFS OFFERS A DEEPER/SLOWER CLOSED
UPPER LOW LINGERING OVER THE INTL BORDER THROUGH TUESDAY...WHILE THE
ECMWF IS MUCH MORE PROGRESSIVE PUSHING THE SYSTEM NORTH AND EAST OF
THE AREA. GFS ENSEMBLE GUIDANCE IS MORE IN LINE WITH THE ECMWF...SO
HAVE LEANED TOWARDS THE FASTER/DRIER SOLUTION FOR MONDAY ONWARDS.
TEMPS THROUGH THE PERIOD REMAIN VERY SEASONAL WITH HIGHS GENERALLY
IN THE MID 70S TO LOWER 80S...AND LOWS IN THE MID 50S TO MID 60S.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...AVIATION CHALLENGE WL BE DISSIPATION OF
STRATO CUMULUS DECK LATE THIS AFTN/EVENING...FOLLOWED BY FOG/BR
POTENTIAL. CRNT VIS SATL PIC SHOWS LOTS OF STRATO CU ACRS OUR TAF
SITES...ASSOCIATED WITH NW UPSLOPE FLW AND LLVL CAA. SOME
UNCERTAINTY TO WHEN THIS DISSIPATES...AS RAP SHOWS LLVL MOISTURE
HANGING AROUND THRU 04Z...ESPECIALLY AT MPV/SLK...WHILE GFS/NAM
SHOW RAPID DECREASE IN RH BTWN 18Z-21Z TODAY. WL USE COMPROMISE
AND SHOW MVFR CIGS IMPROVING TO VFR AT ALL TAF SITES BY EARLY THIS
EVENING. IN ADDITION...AS LLVL`S STABILIZE FROM LACK OF SFC
HEATING...EXPECT WINDS TO DECREASE AT 4 TO 8 KNTS. SOUNDINGS SHOW
BL WINDS BTWN 6 AND 12 KNOTS TONIGHT...AS SFC HIGH PRES IS ACRS
THE CENTRAL GREAT LAKES...ALONG WITH SOME LEFTOVER
CLOUDS...ESPECIALLY ACRS THE UPSLOPE TAF SITES OF MPV/SLK. THIS
MOISTURE AND WIND...MAY PREVENT WIDESPREAD FOG/BR FROM DEVELOPING.
HAVE MENTION TEMPO GROUP AT MSS/SLK BTWN 07Z-11Z. OTHERWISE...VFR
WL PREVAIL BTWN 12-18Z THURS.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
MAINLY VFR CONDITIONS WL PREVAIL THRU SUNDAY...AS WEAK SFC LOW
PRES TRACKS TWD CAPE COD ON FRIDAY...BUT BEST MOISTURE WL STILL
EAST OF OUR FA. ANOTHER SYSTEM ON SUNDAY WL PRODUCE SCATTERED
SHOWERS WITH A CHANCE OF THUNDER ACRS OUR CWA. EXPECT MAINLY VFR
BUT A BRIEF PERIOD OF MVFR IN THE STRONGER STORMS WL BE
POSSIBLE...ESPECIALLY SUNDAY AFTN.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RJS
NEAR TERM...JMG
SHORT TERM...RJS
LONG TERM...LAHIFF
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
140 AM EDT WED JUL 24 2013
.SYNOPSIS...
ADDITIONAL SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
STILL BE POSSIBLE UNTIL A STRONG COLD FRONT PASSES THROUGH
OVERNIGHT. MUCH DRIER AND COOLER WEATHER WILL SETTLE IN FOR
WEDNESDAY THROUGH FRIDAY COURTESY OF CANADIAN HIGH PRESSURE.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
730 PM UPDATE...
FRONTAL BNDRY IS DROPPING THRU CANADA ATTM. PRE-FRONTAL TROF IS
POISED TO CROSS THE GREAT LKS WITH SHOWERS/TSTMS DVLPNG JUST AHD
OF IT, IN COMBINATION WITH MCV ROTATING THRU WRN NY. A BROKEN
LINE OF CONVECTION IS LOCATED ACRS SRN ONTARIO WELL AHD OF MAIN
CDFNT. AS IT STANDS NOW, DO NOT EXPECT THIS LINE OF CONVECTION TO
SUSTAIN ITSELF MUCH LONGER WITH LOSS OF DIURNAL HTG AND
INSTABILITY ON THE WANE. HWVR, CANNOT RULE OUT SCTD SHOWERS/ISOLD
THUNDER AS THIS PRE-FRONTAL TROF/CDFNT MV THRU CWA OVRNGT.
LATEST HRRR SHOWS LINE OF CONVECTION CROSSING ACRS SRN SXNS OF CWA
OVRNGT TONIGHT BUT AS OF 23Z IT IS NOT EVEN CLOSE TO BEING IN LINE
WITH REALITY. THUS, HV DISCOUNTED IT AND HV SIDED MORE WITH HIRES
ARW WHICH SHOWS VRY ISOLD CONVECTION THRU THE NIGHT WITH SOME
SHOWERS EXPECTED AFT 06Z WITH MAIN COLD FRONT.
HV UPDATED SKY GRIDS INITIALLY WITH MOCLDY EXPECTED THRU 02Z ACRS
WRN ZONES AND DIMINISHING WITH SUNSET. PCLDY-MOCLDY WL EXIST THRU
MOST OF THE NIGHT, ESPECIALLY IN AREAS DOWNWIND OF LK ONTARIO AS
MOISTURE GETS TRAPPED UNDER SUBSIDENCE INVERSION AFT 08Z. HV KEPT
MENTION OF ISOLD SHOWERS BUT MAY BE LOOKING AT MORE OF A DRIZZLE/FOG
SCENARIO UNDER LOW CLD CVR. NO OTHER CHGS MADE TO MINS/WINDS AT
THIS TIME AS ALL LOOKS TO BE ON TARGET.
PREV DISCUSSION BLO...
230 PM UPDATE...
UPPER WAVE EXITED THIS MORNING...TAKING AWAY THE DEEPER MOISTURE
WITH IT. HOWEVER...WE STILL HAVE A FEW FEATURES TO DEAL WITH
BEFORE HIGH PRESSURE BUILDS IN AND SHUTS THINGS DOWN. LOOSELY-
DEFINED SURFACE LOW HAS MOVED TO THE MID HUDSON VALLEY WITH A
FRONTAL BOUNDARY /INITIAL COLD FRONT/ DRAGGING BEHIND IT.
ASSOCIATED LOW LEVEL CONVERGENCE ZONE HAS YIELDED SCATTERED
SHOWERS AND AN OCCASIONAL LIGHTNING STRIKE GENERALLY FROM THE
CATSKILLS TO WYOMING VALLEY...NOW SHIFTING SOUTHEAST THROUGH THE
POCONOS. ACTIVITY PROBABLY WOULD BE BETTER ORGANIZED IF IT OUR
REGION HAD NOT BEEN IN THE UNFAVORABLE LEFT ENTRANCE REGION OF A
DEPARTING JET THIS MORNING TO EARLY AFTERNOON.
MEANWHILE...SECONDARY STRONG COLD FRONT IS IGNITING CONVECTION IN
LOWER MICHIGAN. THIS WILL TRAVEL THROUGH LATE TONIGHT WITH A BATCH
OF SCATTERED SHOWERS. AT THIS TIME...FIGURING LOSS OF DIURNAL
HEATING AND LOWERING PWATS WILL PROBABLY PREVENT THUNDER AFTER
MIDNIGHT...NOT COMPLETELY IMPOSSIBLE BUT SHOULD BE THE EXCEPTION
NOT THE RULE. HOWEVER...BETWEEN THE TWO FRONTS...WE HAVE A
SHORTWAVE RUNNING OUT AHEAD OF THE SECONDARY FRONT. THIS IS
CURRENTLY PRODUCING CONVECTION FROM EASTERN OHIO TO JUST NORTH OF
THE WESTERN TIP OF LAKE ONTARIO. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE FIGURED THIS EVENING FROM THIS ACTIVITY...FOR AT
LEAST THE NORTHWEST TO CENTRAL PORTIONS OF OUR AREA.
WE WILL NEED TO WATCH THE LOCALIZED AREAS THAT RECEIVED HEAVY
RAINFALL IN THE LAST 18-24 HOURS JUST IN CASE...BUT AT THIS POINT NOT
EXPECTING WATER PROBLEMS BECAUSE OF DECREASING PRECIPITABLE WATER
VALUES...LIMITED GAPPY COVERAGE TO THE CONVECTION...AND THE
PROGRESSIVE NATURE OF INDIVIDUAL CELLS THIS EVENING INTO OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
1 PM UPDATE...
LONG STORY SHORT...LARGE CANADIAN HIGH PRESSURE BUILDS IN WITH DRY
AND COOL AIR MASS. THIS WILL INCLUDE THE COOLEST TEMPERATURES OF
JULY 2013 BY EARLY THURSDAY MORNING.
ON THE FRONT EDGE OF THE BUILDING HIGH...SOME LOW LEVEL MOISTURE
WILL BE TRAPPED UNDER DEVELOPING SUBSIDENCE INVERSION EARLY
WEDNESDAY. GIVEN THE FAIRLY SHALLOW NATURE OF IT...EXPECTING
CLOUDS AND PERHAPS A COUPLE SPRINKLES FOR A TIME EARLY WEDNESDAY
MORNING...BEFORE VERY DRY AIR MASS BECOMES FULLY REALIZED LATE
MORNING THROUGH WEDNESDAY AFTERNOON...ERADICATING CLOUDS VIA COLD
AIR ADVECTION AND MIXING DOWN OF VERY DRY AIR FROM MID LEVELS.
PRECIPITABLE WATER VALUES DIVE TO LESS THAN A HALF INCH BY LATE
WEDNESDAY AFTERNOON. THIS IS NEARLY 2 STANDARD DEVIATIONS BELOW
NORMAL FOR JULY. EXCEPT FOR PERHAPS THE LOWEST ELEVATIONS OF
DELAWARE VALLEY IN PIKE COUNTY PA...HIGHS WEDNESDAY SHOULD BE
LIMITED TO UPPER 60S TO MID 70S FOR CNY AND 70S FOR NEPA.
THE COOL FRESH DAY WITH NORTHWEST WINDS GUSTING TO 15-20 MPH...WILL
BE FOLLOWED BY QUICK DECOUPLING OF WINDS WEDNESDAY NIGHT AS CENTER
OF HIGH SHIFTS FROM WESTERN GREAT LAKES TO EASTERN GREAT
LAKES/QUEBEC/ONTARIO. RADIATIONAL COOLING WILL EASILY YIELD THE
COOLEST NIGHT OF THIS MONTH...UPPER 40S TO MID 50S...COOLEST IN
SHELTERED VALLEYS OF THE TWIN TIERS AND WESTERN CATSKILLS AND
MOHAWK VALLEY. CAVEAT ON THIS IS THAT WITH 850MB TEMPERATURES OF
ONLY 6-8 DEGREES CELSIUS...WE MAY ACTUALLY GET SOME LAKE EFFECT
CLOUDS COMING FROM LAKE ONTARIO TO SOME PARTS OF FINGER LAKES AND
CENTRAL SOUTHERN TIER REGIONS. TEMPERATURES WILL BE VERY SENSITIVE
TO RADIATIONAL COOLING SET UP AND THUS CLOUD LAYER DETAILS.
HIGH PRESSURE CENTER WILL TRAVEL ROUGHLY DOWN THE SAINT LAWRENCE
SEAWAY THURSDAY...THEN TO CANADIAN MARITIME PROVINCES FRIDAY...YET
OVERALL THE HIGH PRESSURE WILL REMAIN DOMINANT OF OUR WEATHER. I
WAS ABLE TO REMOVE LINGERING SLIGHT CHANCE OF A SHOWER THAT WAS IN
OUR FAR SOUTHEASTERN ZONES THURSDAY. BY FRIDAY...SOME EASTERLY LOW
LEVEL FLOW UNDER THE HIGH COULD POTENTIALLY ATTEMPT TO BRING IN
MARINE LAYER MOISTURE AGAINST THE POCONOS/CATSKILLS...SO I PLACE
A SLIGHT CHANCE OF A SHOWER THERE BUT OTHERWISE STILL DRY
AREAWIDE. OVERALL...AT LEAST A SURFACE RIDGE WILL KEEP CONTROL FOR
MOST OF THE REGION. HIGHS FRIDAY BACK UP TO NEAR CLIMATOLOGY...YET
WITH DEWPOINTS STILL VERY COMFORTABLE IN THE 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
330 PM EDT UPDATE...
THE MAIN FOCUS OF THE EXTENDED FORECAST IS A STRONG UPPER LEVEL
LOW MOVING SOUTH FROM CANADA INTO THE CENTRAL PLAINS THURSDAY AND
THEN PROPAGATE EASTWARD AND AFFECT THE CWA ON SATURDAY. THE BEST
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE ON SUNDAY AS FRONT
PUSHES THROUGH THE REGION. INCREASED POPS ON SUNDAY AS CONFIDENCE
HAS INCREASED. MODELS INDICATE THAT PWAT VALUES WILL INCREASE ABOVE
1.5 INCHES SO HEAVY RAIN ATTENDANT WITH THE FRONT MAY BE POSSIBLE.
THE COLD FRONT WILL BRING COOLER TEMPS AND MUCH DRIER AIR TO CENTRAL
NY AND NORTHEAST PA. WITH THIS DRIER AIR THERE SHOULD BE A COUPLE
OF DRY PERIODS INTO THE NEW WEEK UNTIL ANOTHER SYSTEM PUSHES
THROUGH MID WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
FNTL BNDRY MVG INTO THE FCST AREA ATTM WITH CONV MVG AHD OF THE
FNT...AND GNRLY EAST OF THE TAF SITES. SOME BRIEF MVFR CIGS AND
VSBYS BHD THE CONV...FLWD BY A RETURN TO VFR ALL STATIONS LATE
TNGT AS MUCH DRIER AIR MVES INTO THE REGION. VFR CONDS WILL THEN
REMAIN THRU THE END OF THE PD AS THE NW FLOW OF DRY AIR CONTS.
WINDS WILL GO LGT AFT 00Z AS A SMALL SC HI BLDS IN AND LWR LVL
DECPLS.
.OUTLOOK...
WED NGT/THU/...VFR
FRI/SAT/SUN...CHANCE OF SCATTERED MVFR CIGS/VSBYS IN DEVELOPING
SHRA/TSRA ACTIVITY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP/PVN
SHORT TERM...MDP
LONG TERM...KAH
AVIATION...CMG/DGM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
922 PM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 921 PM CDT THU JUL 25 2013
ADJUSTED POPS/WX FOR CURRENT TRENDS AND SHORT RANGE MODELS. MOST
OF THE PRECIP CONTINUES TO MOVE SLOWLY ACROSS SOUTHERN CANADA
UNDER THE MAIN UPPER LOW. THE PRIMARY VORT MAX WILL DIG DOWN INTO
THE CWA LATER ON TONIGHT...AND THE NAM AND HRRR CONTINUE TO SHOW
SOME DECENT PRECIP CHANCES FROM THE NORTHERN RED RIVER VALLEY
AND POINTS EASTWARD. THE RAP ON THE OTHER HAND...IS PRETTY SPARSE
WITH PRECIP OVER ALL BUT THE FAR EASTERN CWA AS MUCH OF THE
CANADIAN ACTIVITY DISSIPATES BEFORE MOVING SOUTH. WITH THE
STRENGTH OF THE UPPER SYSTEM WILL NOT PULL POPS COMPLETELY OVER
THE NORTHWESTERN CWA...BUT REDUCED THEM QUITE A BIT TO ISOLATED
SHOWERS PARTICULARLY FOR THE REST OF THE EVENING. ALSO CUT THE
SOUTHWARD EXTENT OF THE PRECIP UNTIL LATER TONIGHT. TEMPS STILL
SEEM ON TRACK TO BOTTOM OUT IN THE 50S. CURRENT FORECAST HAS SOME
UPPER 40S IN THE NORTHWEST WHICH FITS WITH GUIDENCE...BUT WILL
HAVE TO WATCH DEW POINTS AS THE DRIER AIR STILL SEEMS WELL NORTH
IN MANITOBA.
UPDATE ISSUED AT 642 PM CDT THU JUL 25 2013
SHOWERS AND THUNDERSTORMS HAVE DIMINISHED A BIT OVER THE NORTHERN
AND EASTERN CWA...BUT THERE IS STILL QUITE A BIT MORE ON RADAR UP
OVER CANADA ALONG WITH THE MAIN UPPER VORT LOBE. WILL KEEP THE
HIGH CHANCE POPS WE HAVE GOING FOR NOW AS ACTIVITY SHOULD INCREASE
AGAIN AS THE UPPER LOW DIGS INTO THE AREA. DID CHANGE THE WX TO
MENTION SHOWERS WITH ISOLATED THUNDER AS NOT MUCH LIGHTNING HAS
BEEN SEEN BEHIND THE COLD FRONT. MADE SOME MINOR TWEAKS TO CLOUDS
AND TEMPS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 305 PM CDT THU JUL 25 2013
MAIN CHALLENGE WILL BE SHOWER/TSTM CHANCES TONIGHT INTO EARLY
FRIDAY AND THEN TEMPS. MODELS RUNNING PRETTY CLOSE TO CONTINUITY
SO NO BIG FORECAST CHANGES EXPECTED.
QUITE A BIT OF CUMULUS FORMED AGAIN TODAY. ALSO SEEING POPCORN
SHOWERS/TSTMS ACROSS THE NORTH/NE. ONE STORM AROUND CLEARWATER
COUNTY IN MN WAS BRIEFLY SEVERE BUT HAS SINCE FADED. SEEING QUITE
A BIT OF UPSTREAM SHOWERS/ISOLATED THUNDER ACROSS SOUTHERN
MANITOBA ASSOCIATED WITH A NICE SHORT WAVE. THIS WAVE IS EXPECTED
TO ROTATE THRU THE FA TONIGHT SO SHOULD SEE STEADY OR EVEN
INCREASING SHOWERS AND TSTMS INTO THE EVENING. WITH THE STRENGTH
OF THE WAVE SOME MAY EVEN LAST WELL AFTER DARK. THE CUMULUS FIELD
SHOULD THIN OUT WITH LOSS OF HEATING BUT THERE ARE MORE MID AND
UPPER LEVEL CLOUDS ASSOCIATED WITH THE WAVE THAT WILL DROP THRU
TONIGHT WHICH WILL KEEP CLOUD AMOUNTS UP. THE GUSTY NORTHWEST
WINDS SHOULD DROP OFF SOME TONIGHT BUT WILL REMAIN STEADY
OVERNIGHT.
THE MAIN WAVE WILL MOVE SOUTH OF THE FA EARLY FRI BUT THERE WILL
STILL BE ANOTHER PIECE THAT WILL ROTATE THRU DURING THE DAY FRI.
500MB TEMPS ARE QUITE CHILLY WHICH SHOULD RESULT IN QUITE A BIT OF
CUMULUS FORMATION AGAIN AND MORE SPOTTY SHOWERS. SOME SHOWERS MAY
HANG AROUND INTO FRI AFTERNOON ESPECIALLY IN THE EAST. SFC HIGH
PRESSURE WILL DROP INTO CENTRAL ND FRI NIGHT WHICH SHOULD SET THE
STAGE FOR A COLD NIGHT THERE (NEAR RECORD LOWS).
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 305 PM CDT THU JUL 25 2013
SFC HIGH REMAINS IN CONTROL SAT INTO SUNDAY. POSITION OF THE HIGH
SAT NIGHT FAVORS COLDEST TEMPS IN THE EASTERN FA. NOT OUT OF THE
QUESTION FOR RECORD LOWS AGAIN.
FOR SUN NIGHT THROUGH WED AN UPPER RIDGE AND DRY AIRMASS WILL
KEEP THE EARLY PART OF THE PERIOD DRY...BUT THE RIDGE WILL MOVE
OFF TO THE EAST ON MONDAY AND THERE WILL BE INCREASING CHANCES OF
TSTMS MON AFTN INTO THE EVENING AS A WAVE MOVES ACROSS THE
NORTHERN TIER. ACTIVITY SHOULD CONTINUE INTO THROUGH THE DAY ON
TUESDAY AND IMPROVE BY EARLY WED MORNING. DAYTIME HIGHS NEXT WEEK
WILL CONTINUE TO BE BELOW SEASONAL NORMS...WITH MAX TEMPS
GENERALLY IN THE UPPER 70S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 642 PM CDT THU JUL 25 2013
CONTINUED TO KEEP THUNDER MENTION IN BRIEFLY AT KBJI...BUT THINK
THAT THE MAIN ACTIVITY THROUGH TONIGHT WILL BE SCATTERED SHOWERS.
WINDS WILL DECREASE JUST A BIT AFTER SUNSET BUT THE FRONT WILL
KEEP SUSTAINED WINDS ABOVE 12 KTS. MODELS ALL HAVE SOME MVFR CIGS
MOVING IN LATER TONIGHT...AND THIS FITS WITH OBS OVER CYWG AND
CYPG. INCLUDED SOME MVFR CIGS FROM AROUND MIDNIGHT UNTIL EARLY
MORNING HOURS. WE MAY SEE A BRIEF BIT OF CLEARING IN THE
MORNING...BUT WITH COOL CONVECTIVE TEMPS STRATOCU WILL RAPIDLY
REDEVELOP BY LATE MORNING OR EARLY AFTERNOON. KEPT CIGS LATE IN
THE PERIOD LOW VFR FOR NOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...GODON/SPEICHER
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1136 PM CDT TUE JUL 23 2013
.UPDATE...
ISSUED AT 1136 PM CDT TUE JUL 23 2013
THINK THAT ANY PRECIP WILL BE FROM THE NEXT WEAK SHORTWAVE
CURRENTLY OVER SOUTHERN CANADA SO ADJUSTED POPS A BIT TO DELAY ANY
PRECIP UNTIL AFTER 09Z. ADJUSTED CLOUDS A BIT ALSO.
UPDATE ISSUED AT 928 PM CDT TUE JUL 23 2013
ONLY MINOR UPDATES AS ONE WEAK SHORTWAVE BRINGS STORMS INTO SD AND THE
NEXT SHORTWAVE STILL WELL UPSTREAM OVER CANADA. CONTINUE TO THINK
THAT ANY PRECIP WILL BE WELL AFTER MIDNIGHT. LOWERED TEMPS JUST A
BIT IN THE FAR EASTERN COUNTIES AS DEW POINTS HAVE BEEN LOWER IN
THAT AREA.
UPDATE ISSUED AT 627 PM CDT TUE JUL 23 2013
NO MAJOR CHANGES FOR THIS UPDATE AS THE CONVECTION IN CENTRAL ND
IS ON TRACK TO MISS OUR SOUTHWESTERN COUNTIES. THE BETTER CHANCES
FOR ANY PRECIP WILL BE AFTER MIDNIGHT TONIGHT. TEMPS SHOULD BOTTOM
OUT IN THE 50S.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 309 PM CDT TUE JUL 23 2013
MAIN FORECAST CHALLENGE REMAINS PCPN CHANCES OVER THE NEXT FEW
DAYS. MODELS SEEM TO BE IN BETTER AGREEMENT ON THE DETAILS THIS
TIME AROUND WHICH MATCH UP PRETTY WELL WITH FORECAST CONTINUITY.
THEREFORE DO NOT PLAN MANY CHANGES TO THE SHORT TERM.
QUITE A BIT OF CUMULUS FORMED ACROSS THE AREA AGAIN TODAY WHICH
LIKELY HELPED TO HOLD DOWN TEMPS A LITTLE. EXPECT THE CUMULUS TO
THIN OUT THIS EVENING. THE MID AND HIGH LEVEL CLOUDS ASSOCIATED
WITH AREA OF PCPN OVER NORTHWEST ND SHOULD DRIFT INTO PORTIONS OF
THE FA. ANY ACTUAL PCPN SHOULD TRACK FROM NORTHWEST ND DOWN INTO
NORTHEAST SD TONIGHT. LATEST VERSION OF THE RAP SEEMS TO SHOW THIS
WELL. WILL LEAVE INHERITED PCPN CHANCES ACROSS THE SOUTHWEST FOR
LATE TONIGHT BASICALLY AS IS. PRETTY DRY SFC DEW POINT READINGS
ESPECIALLY IN THE EAST SO CUT BACK A LITTLE ON MIN TEMPS THERE.
FOR WED THERE ARE NOT A LOT OF CHANGES FROM TODAY. STILL IN NW
FLOW WITH WEAK EMBEDDED IMPULSES. MODELS ALL SEEM CONSISTENT IN
SHOWING SOME LIGHT PCPN ACROSS THE AREA. THESE CHANCES SHOULD
SHIFT INTO NORTHWEST MN WED NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 309 PM CDT TUE JUL 23 2013
BY THU THE NEXT SFC COLD FRONT WILL SWING THRU THE FA WITH A
LITTLE STRONGER UPPER LEVEL DISTURBANCE. THIS WILL PROBABLY BE THE
TIME PERIOD WITH THE BEST CHANCE FOR PCPN ALTHOUGH AMOUNTS WILL BE
PRETTY LIGHT. WILL LEAVE THU NIGHT DRY. STILL HAVE SOME QUESTIONS
ABOUT PCPN CHANCES AGAIN BY FRI. MODELS ARE INDICATING A
SUBSTANTIAL PIECE OF SHORTWAVE ENERGY DROPPING THROUGH WITH CHILLY
500MB TEMPS. LEFT SOME LOW CHANCES FOR PCPN IN THE EAST.
FOR FRI NIGHT THROUGH TUE...THE PERIOD WILL BEGIN WITH TEMPS
BELOW NORMAL AND DRY WEATHER...WITH COOL CANADIAN HIGH PRESSURE IN
CONTROL. TEMPS AND MOISTURE PROFILES WILL INCREASE BY EARLY NEXT
WEEK...WITH A CHANCE FOR SHOWERS AND STORMS WITH MORE ZONAL FLOW
ALOFT. MOST AREAS COULD REMAIN DRY THROUGH MONDAY...WITH DRY AIR
IN PLACE INITIALLY AND IT WILL TAKE TIME TO MOISTEN COLUMN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1136 PM CDT TUE JUL 23 2013
VFR CONDITIONS WILL CONTINUE AND ANY CONVECTION TOMORROW WILL BE
HIGHLY SCATTERED AND NOT CERTAIN ABOUT HITTING TAF SITES. LIGHT
AND VARIABLE WINDS WILL PICK UP OUT OF THE WEST TO NORTHWEST BY
THE END OF THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...JR
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
959 PM CDT THU JUL 25 2013
.AVIATION...
THUNDERSTORMS FINALLY BEGINNING TO LOSE THEIR PUNCH...BUT NOT
BEFORE PRODUCING SEVERAL STORMS THAT PRODUCED QUITE A BIT OF
LIGHTNING IN THE METROPLEX...AWAY FROM THE TERMINAL SITES.
ATTENTION THEN TURNS TO WHETHER OR NOT THE MCS CAN FORM IN AREAS
TO THE NORTHWEST. THE PREVIOUS DISCUSSION...BELOW...TALKS ABOUT
THAT POTENTIAL IN DEPTH.
OVERNIGHT...EXPECTING VFR CEILINGS ACROSS MUCH OF THE AREA...WITH
THE LONE EXCEPTION BEING WACO. WILL CONTINUE TO CLOSELY MONITOR
TRENDS ABOUT THE POTENTIAL FOR RAIN AND/OR THUNDERSTORMS IN THE
EARLY MORNING HOURS. FOR NOW...BELIEVE THE MOST LIKELY FORECAST IS
FOR LOWERED...BUT VFR...CEILINGS BY 14Z. ATTENTION THEN TURNS TO
THE COLD FRONT PASSAGE AND WIND SHIFT. MAY NEED TO UPDATE THE
TIMING FOR THE 06Z TAFS...BUT THE 03Z WILL CONTINUE TO LOOK AT A
WIND SHIFT IN THE METROPLEX AROUND 21Z...AND A WIND SHIFT IN WACO
AROUND 23Z.
FOX
&&
.UPDATE...
UPPER LEVEL SHORTWAVE TROUGH CURRENTLY IN THE HIGH PLAINS WILL
CONTINUE TO APPROACH NORTH TEXAS FROM THE NORTHWEST TONIGHT. AHEAD
OF THIS UPPER LEVEL ENERGY...SCATTERED SHOWERS AND STORMS HAVE
DEVELOPED ACROSS OKLAHOMA/KANSAS/NW TEXAS. SO FAR ACTIVITY HAS NOT
CONGEALED INTO AN ORGANIZED MCS...LIKELY DUE TO ANVIL LEVEL WINDS
BEING MUCH FASTER THAN INDIVIDUAL STORM MOTIONS. THIS MEANS
CONVECTION HAS A HARD TIME DEVELOPING A STRONG COLD POOL THAT
HELPS TO GENERATE ADDITIONAL CONVECTION AND EVENTUALLY AN
ORGANIZED MCS. MCS DEVELOPMENT IN THE ABSENCE OF STRONG FORCING
TENDS OCCUR MOST EASILY WHEN STRATIFORM/ANVIL PRECIPITATION TRAILS
CONVECTIVE CELL MOTIONS. SINCE STRONG ANVIL LEVEL FLOW WILL
PERSIST OVERNIGHT...EXPECT CONVECTIVE ACTIVITY TO REMAIN MORE
SCATTERED IN AREAS TO OUR NORTH AND NORTHWEST WITH THE CHANCE OF A
MCS BLASTING THROUGH THE REGION AT SUNRISE RATHER LOW. HOWEVER THE
UPPER LEVEL FORCING SHOULD BEGIN TO ARRIVE INTO THE NW ZONES LATE
TONIGHT AND WITH A SUFFICIENT AMOUNT OF ELEVATED INSTABILITY
AVAILABLE IN THE AREA...EXPECT SCATTERED ELEVATED CONVECTION TO
DEVELOP/MOVE INTO THE AREA FROM THE NORTHWEST. HAVE BUMPED UP POPS
TO CHANCE IN THE NW ZONES AND BROUGHT THE SLIGHT CHANCES FARTHER
TO THE SOUTHEAST TOWARD DAYBREAK. BEST UPPER LEVEL FORCING WILL
OVERSPREAD THE REGION DURING THE DAY ON FRIDAY AND POPS INCREASE
OVER THE AREA AFTER SUNRISE.
TR.92
&&
.PREV DISCUSSION... /ISSUED 350 PM CDT THU JUL 25 2013/
WEATHER CHANGES ARE ON THE WAY FOR NORTH AND CENTRAL TEXAS FRIDAY
THROUGH THE WEEKEND. A SHORTWAVE TROUGH CURRENTLY MOVING INTO THE
SOUTHERN PLAINS WILL CONTINUE MOVING SOUTHEAST FRIDAY AND IS
EXPECTED TO BE EAST OF THE REGION BY SATURDAY. AT THE SURFACE...A
LOW PRESSURE SYSTEM DEVELOPING IN THE PLAINS OF COLORADO WILL ALSO
MOVE SOUTHEAST REACHING NORTHWEST TEXAS FRIDAY MORNING. IN
ASSOCIATION WITH THE UPPER LEVEL TROUGH AND SURFACE LOW
PRESSURE...A COMPLEX OF THUNDERSTORMS IS EXPECTED TO DEVELOP NORTH
OF THE REGION THIS EVENING AND TONIGHT. A SECONDARY COMPLEX MAY
ALSO DEVELOP IN THE TEXAS PANHANDLE...POSSIBLY FROM CONVECTION
THAT IS CURRENTLY DEVELOPING IN THE LUBBOCK AREA. THE HRRR IS
SUGGESTING THE COMPLEX IN THE PANHANDLE WILL MOVE EAST REACHING
THE WESTERN COUNTIES OF OUR CWA LATE TONIGHT...BUT WEAKENING AS IT
APPROACHES THE WESTERN BORDER. HOWEVER...THE HRRR IS ALSO FARTHER
EAST WITH THE DEVELOPMENT OF THE COMPLEX THAN WHERE CURRENT
CONVECTION IS OCCURRING AROUND THE LUBBOCK AREA. WILL NEED TO
MONITOR TRENDS OUT WEST THROUGH THE EVENING HOURS FOR THE POTENTIAL
INCLUSION OF POPS IN OUR WESTERN COUNTIES OVERNIGHT.
THE MAIN COMPLEX OF STORMS IS EXPECTED TO TRAVEL EAST OR EAST-
SOUTHEAST ACROSS OKLAHOMA TONIGHT AND COULD GRAZE OUR NORTHERN
COUNTIES FRIDAY MORNING. HAVE KEPT LOW POPS NEAR THE RED RIVER
BEFORE DAYBREAK WITH INCREASING RAIN CHANCES AFTER DAYBREAK. THE
MODELS CONSISTENTLY KEEP THE MAJORITY OF THIS COMPLEX NORTH OF THE
RED RIVER...EXCEPT DIPPING ACROSS OUR NORTHERN AND NORTHEASTERN
COUNTIES DURING THE DAY ON FRIDAY. THE 4 KM WRF IS THE ONLY MODEL
EXPLICITLY SHOWING THE SOUTHERN EDGE OF THIS COMPLEX FARTHER
SOUTH...MOVING ALONG AND NORTH OF I-20 FRIDAY MORNING. HAVE
INCREASED POPS ALONG AND NORTH OF I-20 FRIDAY MORNING WITH LIKELY
POPS ALONG THE RED RIVER.
A COOL FRONT IS EXPECTED TO ACCOMPANY THE SURFACE LOW
PRESSURE...MOVING INTO NORTH TEXAS FRIDAY AFTERNOON. ADDITIONAL
BUT MORE SCATTERED RAIN ACTIVITY IS EXPECTED ALONG THE FRONT AND
HAVE INCREASED POPS ACROSS MOST OF THE CWA FOR FRIDAY AFTERNOON
AS THE FRONT MOVES INTO THE AREA. THE HIGHEST RAIN CHANCES
CONTINUE OVER THE NORTHEASTERN COUNTIES IN THE AFTERNOON HOURS.
THE RAIN ACTIVITY IS EXPECTED TO DIMINISH FRIDAY EVENING AS THE
FRONT MOVES FARTHER SOUTH OF INTERSTATE 20 BUT WILL STILL CARRY
LOW CHANCE POPS ACROSS THE SOUTHERN COUNTIES FRIDAY EVENING. THE
RAIN WILL COME TO AN END FRIDAY NIGHT AS THE FRONT PUSHES SOUTH OF
THE REGION. FORECAST SOUNDINGS ARE NOT VERY SUPPORTIVE OF A SEVERE
WEATHER POTENTIAL ON FRIDAY BUT CANNOT RULE OUT A FEW STRONG OR
POSSIBLY MARGINALLY SEVERE THUNDERSTORMS ALONG THE FRONT FRIDAY
AFTERNOON. WIND AND HAIL WOULD BOTH BE THREATS. AS MENTIONED IN
THE SPC DAY2 OUTLOOK...WILL ALSO HAVE TO WATCH FOR ANY OUTFLOW
BOUNDARIES COMING OFF THE OKLAHOMA MCS THAT COULD PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT AHEAD OF THE FRONT.
HOWEVER...INCREASING CLOUD COVER AHEAD OF THE FRONT COULD INHIBIT
WARMING AND INSTABILITY ALONG ANY OUTFLOW BOUNDARIES.
TEMPERATURES TOMORROW WILL VARY FROM THE MID 80S IN THE NORTHEAST
WHERE THE HIGHEST RAIN CHANCES ARE TO THE UPPER 90S IN THE SOUTH.
HOWEVER... COOLER TEMPERATURES ARE EXPECTED REGION-WIDE OVER THE
WEEKEND WITH HIGHS ON SATURDAY IN THE LOWER 90S. THE UPPER LEVEL
RIDGE MOVES OVER THE REGION EARLY NEXT WEEK AND UPPER 90S TO
TRIPLE DIGITS WILL RETURN.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 78 95 72 92 73 / 20 40 30 10 5
WACO, TX 77 98 75 94 74 / 10 30 30 10 10
PARIS, TX 74 86 67 90 69 / 20 60 30 10 5
DENTON, TX 76 90 69 91 70 / 20 50 20 5 5
MCKINNEY, TX 75 89 69 91 70 / 20 50 30 10 5
DALLAS, TX 80 95 73 92 75 / 20 40 30 10 5
TERRELL, TX 77 94 71 92 71 / 10 50 30 10 5
CORSICANA, TX 77 97 74 93 73 / 10 40 30 10 10
TEMPLE, TX 75 98 75 94 73 / 10 30 30 10 10
MINERAL WELLS, TX 75 95 70 93 71 / 20 40 30 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
14/92
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
936 PM CDT THU JUL 25 2013
.UPDATE...
UPPER LEVEL SHORTWAVE TROUGH CURRENTLY IN THE HIGH PLAINS WILL
CONTINUE TO APPROACH NORTH TEXAS FROM THE NORTHWEST TONIGHT. AHEAD
OF THIS UPPER LEVEL ENERGY...SCATTERED SHOWERS AND STORMS HAVE
DEVELOPED ACROSS OKLAHOMA/KANSAS/NW TEXAS. SO FAR ACTIVITY HAS NOT
CONGEALED INTO AN ORGANIZED MCS...LIKELY DUE TO ANVIL LEVEL WINDS
BEING MUCH FASTER THAN INDIVIDUAL STORM MOTIONS. THIS MEANS
CONVECTION HAS A HARD TIME DEVELOPING A STRONG COLD POOL THAT
HELPS TO GENERATE ADDITIONAL CONVECTION AND EVENTUALLY AN
ORGANIZED MCS. MCS DEVELOPMENT IN THE ABSENCE OF STRONG FORCING
TENDS OCCUR MOST EASILY WHEN STRATIFORM/ANVIL PRECIPITATION TRAILS
CONVECTIVE CELL MOTIONS. SINCE STRONG ANVIL LEVEL FLOW WILL
PERSIST OVERNIGHT...EXPECT CONVECTIVE ACTIVITY TO REMAIN MORE
SCATTERED IN AREAS TO OUR NORTH AND NORTHWEST WITH THE CHANCE OF A
MCS BLASTING THROUGH THE REGION AT SUNRISE RATHER LOW. HOWEVER THE
UPPER LEVEL FORCING SHOULD BEGIN TO ARRIVE INTO THE NW ZONES LATE
TONIGHT AND WITH A SUFFICIENT AMOUNT OF ELEVATED INSTABILITY
AVAILABLE IN THE AREA...EXPECT SCATTERED ELEVATED CONVECTION TO
DEVELOP/MOVE INTO THE AREA FROM THE NORTHWEST. HAVE BUMPED UP POPS
TO CHANCE IN THE NW ZONES AND BROUGHT THE SLIGHT CHANCES FARTHER
TO THE SOUTHEAST TOWARD DAYBREAK. BEST UPPER LEVEL FORCING WILL
OVERSPREAD THE REGION DURING THE DAY ON FRIDAY AND POPS INCREASE
OVER THE AREA AFTER SUNRISE.
TR.92
&&
.PREV UPDATE...
.UPDATE...
NORTHWARD MOVING OUTFLOW BOUNDARY FROM EARLIER CONVECTION LOOKS
LIKE IT WILL SPARK OFF A FEW STORMS IN THE METROPLEX THIS EVENING
WHERE AIRMASS IS UNCAPPED AND UNSTABLE. HAVE RECONFIGURED THE
SPATIAL ORIENTATION OF THE LOW POPS FOR THIS EVENING BASED ON
LATEST TRENDS. TR.92
&&
.PREV DISCUSSION... /ISSUED 350 PM CDT THU JUL 25 2013/
WEATHER CHANGES ARE ON THE WAY FOR NORTH AND CENTRAL TEXAS FRIDAY
THROUGH THE WEEKEND. A SHORTWAVE TROUGH CURRENTLY MOVING INTO THE
SOUTHERN PLAINS WILL CONTINUE MOVING SOUTHEAST FRIDAY AND IS
EXPECTED TO BE EAST OF THE REGION BY SATURDAY. AT THE SURFACE...A
LOW PRESSURE SYSTEM DEVELOPING IN THE PLAINS OF COLORADO WILL ALSO
MOVE SOUTHEAST REACHING NORTHWEST TEXAS FRIDAY MORNING. IN
ASSOCIATION WITH THE UPPER LEVEL TROUGH AND SURFACE LOW
PRESSURE...A COMPLEX OF THUNDERSTORMS IS EXPECTED TO DEVELOP NORTH
OF THE REGION THIS EVENING AND TONIGHT. A SECONDARY COMPLEX MAY
ALSO DEVELOP IN THE TEXAS PANHANDLE...POSSIBLY FROM CONVECTION
THAT IS CURRENTLY DEVELOPING IN THE LUBBOCK AREA. THE HRRR IS
SUGGESTING THE COMPLEX IN THE PANHANDLE WILL MOVE EAST REACHING
THE WESTERN COUNTIES OF OUR CWA LATE TONIGHT...BUT WEAKENING AS IT
APPROACHES THE WESTERN BORDER. HOWEVER...THE HRRR IS ALSO FARTHER
EAST WITH THE DEVELOPMENT OF THE COMPLEX THAN WHERE CURRENT
CONVECTION IS OCCURRING AROUND THE LUBBOCK AREA. WILL NEED TO
MONITOR TRENDS OUT WEST THROUGH THE EVENING HOURS FOR THE POTENTIAL
INCLUSION OF POPS IN OUR WESTERN COUNTIES OVERNIGHT.
THE MAIN COMPLEX OF STORMS IS EXPECTED TO TRAVEL EAST OR EAST-
SOUTHEAST ACROSS OKLAHOMA TONIGHT AND COULD GRAZE OUR NORTHERN
COUNTIES FRIDAY MORNING. HAVE KEPT LOW POPS NEAR THE RED RIVER
BEFORE DAYBREAK WITH INCREASING RAIN CHANCES AFTER DAYBREAK. THE
MODELS CONSISTENTLY KEEP THE MAJORITY OF THIS COMPLEX NORTH OF THE
RED RIVER...EXCEPT DIPPING ACROSS OUR NORTHERN AND NORTHEASTERN
COUNTIES DURING THE DAY ON FRIDAY. THE 4 KM WRF IS THE ONLY MODEL
EXPLICITLY SHOWING THE SOUTHERN EDGE OF THIS COMPLEX FARTHER
SOUTH...MOVING ALONG AND NORTH OF I-20 FRIDAY MORNING. HAVE
INCREASED POPS ALONG AND NORTH OF I-20 FRIDAY MORNING WITH LIKELY
POPS ALONG THE RED RIVER.
A COOL FRONT IS EXPECTED TO ACCOMPANY THE SURFACE LOW
PRESSURE...MOVING INTO NORTH TEXAS FRIDAY AFTERNOON. ADDITIONAL
BUT MORE SCATTERED RAIN ACTIVITY IS EXPECTED ALONG THE FRONT AND
HAVE INCREASED POPS ACROSS MOST OF THE CWA FOR FRIDAY AFTERNOON
AS THE FRONT MOVES INTO THE AREA. THE HIGHEST RAIN CHANCES
CONTINUE OVER THE NORTHEASTERN COUNTIES IN THE AFTERNOON HOURS.
THE RAIN ACTIVITY IS EXPECTED TO DIMINISH FRIDAY EVENING AS THE
FRONT MOVES FARTHER SOUTH OF INTERSTATE 20 BUT WILL STILL CARRY
LOW CHANCE POPS ACROSS THE SOUTHERN COUNTIES FRIDAY EVENING. THE
RAIN WILL COME TO AN END FRIDAY NIGHT AS THE FRONT PUSHES SOUTH OF
THE REGION. FORECAST SOUNDINGS ARE NOT VERY SUPPORTIVE OF A SEVERE
WEATHER POTENTIAL ON FRIDAY BUT CANNOT RULE OUT A FEW STRONG OR
POSSIBLY MARGINALLY SEVERE THUNDERSTORMS ALONG THE FRONT FRIDAY
AFTERNOON. WIND AND HAIL WOULD BOTH BE THREATS. AS MENTIONED IN
THE SPC DAY2 OUTLOOK...WILL ALSO HAVE TO WATCH FOR ANY OUTFLOW
BOUNDARIES COMING OFF THE OKLAHOMA MCS THAT COULD PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT AHEAD OF THE FRONT.
HOWEVER...INCREASING CLOUD COVER AHEAD OF THE FRONT COULD INHIBIT
WARMING AND INSTABILITY ALONG ANY OUTFLOW BOUNDARIES.
TEMPERATURES TOMORROW WILL VARY FROM THE MID 80S IN THE NORTHEAST
WHERE THE HIGHEST RAIN CHANCES ARE TO THE UPPER 90S IN THE SOUTH.
HOWEVER... COOLER TEMPERATURES ARE EXPECTED REGION-WIDE OVER THE
WEEKEND WITH HIGHS ON SATURDAY IN THE LOWER 90S. THE UPPER LEVEL
RIDGE MOVES OVER THE REGION EARLY NEXT WEEK AND UPPER 90S TO
TRIPLE DIGITS WILL RETURN.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 78 95 72 92 73 / 20 40 30 10 5
WACO, TX 77 98 75 94 74 / 10 30 30 10 10
PARIS, TX 74 86 67 90 69 / 20 60 30 10 5
DENTON, TX 76 90 69 91 70 / 20 50 20 5 5
MCKINNEY, TX 75 89 69 91 70 / 20 50 30 10 5
DALLAS, TX 80 95 73 92 75 / 20 40 30 10 5
TERRELL, TX 77 94 71 92 71 / 10 50 30 10 5
CORSICANA, TX 77 97 74 93 73 / 10 40 30 10 10
TEMPLE, TX 75 98 75 94 73 / 10 30 30 10 10
MINERAL WELLS, TX 75 95 70 93 71 / 20 40 30 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
305 PM CDT WED JUL 24 2013
.DISCUSSION...
A WEAK OUTFLOW BOUNDARY OVER EXTREME NE TEXAS WILL SAG SLOWLY
SOUTH THROUGH THIS EVENING. CONVECTION IS DEVELOPING ALONG THE
BOUNDARY AND THE RAP AND HRR BRING A FEW SHRA/TSRA INTO THE
EXTREME NORTHERN PART OF SE TX. WILL CONTINUE TO ADVERTISE
ISOLATED ACTIVITY OVER THE NE ZONES THIS EVENING. A BIT MORE CLOUD
COVER TODAY THAN PREVIOUS DAYS AND THIS HAS KEPT TEMPS IN CHECK
THIS AFTN. 500 HEIGHTS CONTINUE TO BUILD THURSDAY AND FRIDAY SO
THINK THE CURRENT TREND OF WARMER TEMPS IS ON THE MARK. ECMWF
LOOKS A LITTLE TOO WARM SO SPLIT THE DIFFERENCE BETWEEN THE ECMWF
AND GFS. ONLY SIGNIFICANT CHANGE TO GOING FORECAST WAS TO RAISE
RAIN CHANCES FOR SATURDAY. MODELS ARE MORE AGGRESSIVE WITH A
DIGGING S/WV ON THE PERIPHERY OF THE UPPER HIGH LOCATED OVER THE
INTERMOUNTAIN WEST. PW VALUES WILL INCREASE TO NEAR 2.00 INCHES ON
SATURDAY AND JET DYNAMICS LOOK RATHER FAVORABLE WITH SE TX LYING
IN A LEFT FRONT QUAD AND UPPER LEVEL WINDS BECOMING DIVERGENT.
WILL RAISE POPS TO CHANCE ACROSS ALL OF SE TX FOR SATURDAY. THE
UPPER LEVEL RIDGE REASSERTS ITSELF ON SUNDAY AND BEYOND AND RAIN
CHANCES WILL BEGIN TO DECLINE. WILL MAINTAIN SLIGHT RAIN CHANCES
ON SUNDAY AND THAT LOOKS KINDA GENEROUS CONSIDERING THE STRENGTH
OF THE BUILDING RIDGE. UPPER LEVEL RIDGING PARKS OVER WEST TEXAS
TUESDAY THROUGH THURSDAY WITH VERY WARM AND DRY CONDITIONS
EXPECTED. 43
&&
.MARINE...
LOWER TO MID LEVEL HIGH PRESSURE OVER THE GULF WILL MAINTAIN AN
EARLY DAY SOUTHWEST...BACKING SOUTH THROUGH THE DAY...LIGHT TO
MODERATE WIND FIELD. THIS FETCH WILL KEEP SEA HEIGHTS IN THE TWO TO
THREE FOOT RANGE NEARSHORE...BETWEEN THREE TO FOUR FEET FURTHER
OFFSHORE. AN INCREASED CHANCE FOR PRECIPITATION SATURDAY AS AN
INLAND BOUNDARY ADVANCES INTO EASTERN TEXAS. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 75 99 76 100 76 / 10 10 10 10 10
HOUSTON (IAH) 76 97 77 97 77 / 10 10 10 10 10
GALVESTON (GLS) 79 92 80 92 81 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1149 AM CDT WED JUL 24 2013
.AVIATION...
PREVAILING VFR CONDITIONS ARE EXPECTED AT BOTH TERMINALS THIS
TAF CYCLE... WITH POSSIBLE BRIEF EXCEPTIONS AT LBB AS ISOLATED TO
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
IN THE AREA DURING THE AFTERNOON. THE STRONGEST STORMS MAY PRODUCE
SMALL HAIL AND WIND GUSTS TO 60 MPH...ALTHOUGH THIS WILL BE THE
EXCEPTION AND NOT THE RULE. STORMS SHOULD DIMINISH BY SUNSET...
WITH POSSIBLE BRIEF STORM DURING THE OVERNIGHT HOURS. CHANCES OF
THE LATTER OCCURRING ARE TOO LOW FOR MENTION IN THIS EDITION OF THE
TAF.
&&
.PREV DISCUSSION... /ISSUED 948 AM CDT WED JUL 24 2013/
UPDATE...
A FEW TWEAKS TO TODAYS FORECAST TO REFLECT CURRENT TRENDS. THE
CONVECTIVE COMPLEX ACROSS NORTH TX APPEARS TO BE REINFORCING THE
COLD FRONT...NOW ACROSS THE NORTHERN SOUTH PLAINS AND ROLLING
PLAINS. SHORT RANGE MODEL GUIDANCE...INCLUDING THE
HRRR...TTUWRF...AND RAP ALL INDICATE THAT THIS FRONT WILL LIKELY
REACH AT LEAST THE SOUTHERN PORTION OF THE CWA BY MID
AFTERNOON...AND PERHAPS EVEN BEYOND AS SHOWN BY THE AGGRESSIVE
ECMWF. AS A RESULT...OPTED TO SHIFT POPS SOUTHWARD TO FAVOR THE
SOUTHERN ROLLING PLAINS AND SOUTH PLAINS FOR THIS AFTERNOON.
CONVECTION IS EXPECTED TO REMAIN TIED TO THE BOUNDARY TODAY GIVEN
SOMEWHAT WARM MID-LEVEL TEMPERATURES AND A LACK OF ANOTHER WELL-
DEFINED FORCING MECHANISM...WITH THE EXCEPTION OF THE HIGH TERRAIN
OF NEW MEXICO...AND AS A RESULT PORTIONS OF THE NORTHERN ROLLING
PLAINS WILL LIKELY REMAIN DRY. FARTHER WEST...MORE ROBUST
CONVECTIVE DEVELOPMENT IS EXPECTED ACROSS EASTERN NEW MEXICO
WITHIN AN UPSLOPE FLOW REGIME...AND AT LEAST SOME OF THIS ACTIVITY
IS EXPECTED TO REACH AT LEAST THE WESTERN SOUTH PLAINS LATE IN THE
AFTERNOON AND INTO THE EVENING. GIVEN THE MODERATE INSTABILITY
PRESENT... A FEW PULSE-TYPE THUNDERSTORMS MAY BE CAPABLE OF
PRODUCING SMALL HAIL AND GUSTY WINDS... ALTHOUGH ANEMIC SHEAR WILL
LIKELY PRECLUDE A WIDESPREAD SEVERE THREAT. IN ADDITION... A FEW
SHOWERS AND PERHAPS A RUMBLE OF THUNDER OR TWO WILL BE POSSIBLE AS
THE GUST FRONT MOVES THROUGH THE SOUTHERN ROLLING PLAINS THIS
MORNING THROUGH THE EARLY AFTERNOON AS WELL.
PREV DISCUSSION... /ISSUED 634 AM CDT WED JUL 24 2013/
AVIATION...
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. WEAK FRONTAL
BOUNDARY WILL SAG SOUTHWARD DURING THE DAY. THERE IS SOME RISK OF
TSTMS THIS AFTERNOON AND EVENING /THOUGH FAVORING KCDS/ AT BOTH
TERMINALS.
PREV DISCUSSION... /ISSUED 319 AM CDT WED JUL 24 2013/
SHORT TERM...
FLOW OVER THE CONUS THIS MORNING IS CHARACTERIZED BY LARGE SCALE
RIDGING OUT WEST AND TROUGHING ACROSS THE EAST. UPPER LEVEL HIGH
HAS EXPANDED OUR WAY A BIT MORE FOR TODAY WHICH WILL HELP TEMPS RISE
A FEW DEGREES. POLAR JET IS ORIENTED FROM SK TO TN. THE ASSOCIATED
H5 WIND MAX IS EXPECTED TO DRIVE FARTHER SOUTH A BIT TODAY TO
INCLUDE NWRN OK. AT THE SFC...A WEAK FRONTAL BOUNDARY IS SITUATED
ACROSS THE NORTHERN TX PANHANDLE AND IS CURRENTLY LITTLE MORE THAN
A WIND SHIFT LINE. FRONTOGENETICAL FORCING HAS BEEN INSUFFICIENT
THUS FAR IN INITIATING CONVECTION. NWP APPEARS FAIRLY CONSISTENT
IN PUSHING THIS BOUNDARY SLOWLY SOUTHWARD TODAY IN RESPONSE TO
ANEMIC EMBEDDED TROUGH WHICH IS EVIDENT AT H5. THE QUESTION IS
WHETHER DYNAMICAL PROCESSES WILL BE SUFFICIENT TO INITIATE
CONVECTION ACROSS OUR CWFA THIS AFTERNOON. WHILE OUR AREA IS ON
THE SUBSIDENT SIDE OF THE POLAR JET...AND SOME RESEMBLANCE OF A
CAP IS EVIDENT ON FCST SOUNDINGS...THE MERE PRESENCE OF THE
SURFACE CONVERGENCE WILL BE VERY HELPFUL IN HELPING TO REALIZE
TSTM DEVELOPMENT. WHILE BULK SHEAR IS QUITE WEAK...INSTABILITY MAY
BE SUFFICIENT FOR A FEW PULSE STRONG TO POSSIBLY SEVERE STORMS TO
DEVELOP WITH HAIL TO THE SIZE OF NICKELS AND GUSTS TO AROUND 60
MPH POSSIBLE IN ANY STORMS WHICH MANAGE TO BECOME ESTABLISHED.
STORM MOTION WILL BE QUITE SLOW (LESS THAN 10 MPH) AND THUS A FEW
LUCKY LOCATIONS MAY PICK UP A QUICK HALF INCH TO AN INCH.
HOWEVER...METEOROLOGICAL SCIENCE WITH THE OBSERVATIONAL NETWORK
AVAILABLE TODAY IS INSUFFICIENT TO US TO PINPOINT WHERE THAT MIGHT
BE OTHER THAN THE NORTHERN ZONES WILL HAVE THE BEST OPPORTUNITY
FOR RAIN.
LONG TERM...
THE EXTENDED FORECAST WILL START OFF WITH CHANCES FOR PRECIP
INITIALLY FOR THE SRN TX PANHANDLE/NORTHERN SOUTH PLAINS...THANKS TO
A 15-25 KT NOCTURNAL LLJ AND /MOST IMPORTANTLY/ A NRLY COLD FRONT
THAT WILL STALL ACROSS THE SRN TX PANHANDLE TONIGHT. THIS FRONT IS
IN ASSOCIATION WITH A SUBTLE SHORTWAVE PROGGED TO MOVE SE ACROSS THE
CENTRAL PLAINS. THE FRONT WILL LIKELY WASH OUT BY TOMORROW AFTN
DURING AT WHICH TIME THE CENTER OF THE UA RIDGE THAT WAS ONCE
OVERHEAD WOULD BE SOUTH OF THE REGION. AS SUCH...MONSOONAL STORM
ACTIVITY ACROSS E NM COULD SHIFT TO ACROSS WRN ZONES DUE TO ADEQUATE
SW STEERING FLOW.
THURSDAY NIGHT-FRIDAY CHANCES FOR RAINFALL COULD BECOME REALIZED FOR
THE REMAINDER OF THE CWA. A SHARPER SHORTWAVE TROUGH WILL BE
SKIRTING SE ACROSS THE CENTRAL PLAINS HEADING TOWARDS OKLAHOMA. THIS
WILL CAUSE THE UA RIDGE TO RETROGRADE JUST ENOUGH TO ALLOW FLOW
ALOFT TO VEER TO THE NW. ALTHOUGH THE BEST LIFT WILL BE WELL NE OF THE
REGION...THE FAVORABLE NW FLOW ALOFT WILL ENCOURAGE MOUNTAINOUS
PRECIP ACTIVITY TO TRANSLATE SE ACROSS THE SOUTHERN PLAINS.
THEREAFTER...A COLD FRONT WILL MOVE ACROSS THE ENTIRE CWFA FRIDAY
EVENING/NIGHT...HENCE BEING ANOTHER SOURCE OF PRECIP DEVELOPMENT AS
FRONTOGENETICAL FORCING WORKS WITH AN ENE UPSLOPE WIND COMPONENT.
PWATS ARE PROGGED TO INCREASE TO 1.20-1.80 INCHES AND MID-LEVEL CAPE
VALUES OF A FEW HUNDRED J/KG SUGGESTS THAT MODERATE RAINFALL AND
ISOLATED STRONG STORMS ARE PLAUSIBLE RESPECTIVELY. THIS
WEEKEND-EARLY NEXT WEEK...THE UA RIDGE ALBEIT FLATTENED...WILL MAKE
A RETURN TO THE SOUTHERN PLAINS THUS CAUSING INCREASING DIFFICULTY
IN STORM DEVELOPMENT /MID-LEVEL CAP WILL EXIST/. HOWEVER...ADEQUATE
SW MEAN FLOW COULD ONCE AGAIN URGE THE MONSOONAL MOISTURE
PLUME/PRECIP TO BEND ACROSS THE WRN AND NWRN ZONES. EARLY NEXT
WEEK-MID WEEK...LONG TERM SOLUTIONS HINT AT YET ANOTHER SHORTWAVE
TROUGH HAVING THE POTENTIAL TO TAKE THE EXACT SAME TRACK AS THE
ONE EXPECTED THURSDAY NIGHT-FRIDAY /PER THE GFS/ OR A BIT FARTHER
NE /PER THE ECMWF/. THIS WILL CAUSE THE UA RIDGE TO ONCE AGAIN
RETROGRADE AND PROMOTE NW FLOW ALOFT /MOVING STORMS OFF THE
MOUNTAINS AND TOWARDS THE FA/...NOT TO MENTION MAKING WAY FOR
ANOTHER FRONT AND ACCOMPANIED PRECIP. WILL HOLD OFF ON MENTIONABLE
POPS FOR NEXT WEEK AND AWAIT A CONSISTENT QPF SIGNAL.
TEMPS WILL COOL OFF INTO THE UPPER 80S TO LOWER 90S BY THE
WEEKEND...BUT WILL REBOUND BACK TO ABOVE NORM BY EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 68 91 66 87 65 / 30 20 20 20 20
TULIA 70 91 66 88 65 / 20 20 20 20 20
PLAINVIEW 70 92 67 89 66 / 20 20 20 20 20
LEVELLAND 71 95 68 92 67 / 20 20 20 20 20
LUBBOCK 71 95 70 93 68 / 20 20 20 20 20
DENVER CITY 71 96 68 94 67 / 30 20 20 20 20
BROWNFIELD 72 96 68 94 68 / 20 10 20 20 20
CHILDRESS 72 97 71 94 70 / 10 20 20 20 30
SPUR 74 97 70 95 71 / 20 10 20 20 20
ASPERMONT 74 99 72 97 72 / 20 10 10 20 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
16/23/16
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
948 AM CDT WED JUL 24 2013
.UPDATE...
A FEW TWEAKS TO TODAYS FORECAST TO REFLECT CURRENT TRENDS. THE
CONVECTIVE COMPLEX ACROSS NORTH TX APPEARS TO BE REINFORCING THE
COLD FRONT...NOW ACROSS THE NORTHERN SOUTH PLAINS AND ROLLING
PLAINS. SHORT RANGE MODEL GUIDANCE...INCLUDING THE
HRRR...TTUWRF...AND RAP ALL INDICATE THAT THIS FRONT WILL LIKELY
REACH AT LEAST THE SOUTHERN PORTION OF THE CWA BY MID
AFTERNOON...AND PERHAPS EVEN BEYOND AS SHOWN BY THE AGGRESSIVE
ECMWF. AS A RESULT...OPTED TO SHIFT POPS SOUTHWARD TO FAVOR THE
SOUTHERN ROLLING PLAINS AND SOUTH PLAINS FOR THIS AFTERNOON.
CONVECTION IS EXPECTED TO REMAIN TIED TO THE BOUNDARY TODAY GIVEN
SOMEWHAT WARM MID-LEVEL TEMPERATURES AND A LACK OF ANOTHER WELL-
DEFINED FORCING MECHANISM...WITH THE EXCEPTION OF THE HIGH TERRAIN
OF NEW MEXICO...AND AS A RESULT PORTIONS OF THE NORTHERN ROLLING
PLAINS WILL LIKELY REMAIN DRY. FARTHER WEST...MORE ROBUST
CONVECTIVE DEVELOPMENT IS EXPECTED ACROSS EASTERN NEW MEXICO
WITHIN AN UPSLOPE FLOW REGIME...AND AT LEAST SOME OF THIS ACTIVITY
IS EXPECTED TO REACH AT LEAST THE WESTERN SOUTH PLAINS LATE IN THE
AFTERNOON AND INTO THE EVENING. GIVEN THE MODERATE INSTABILITY
PRESENT... A FEW PULSE-TYPE THUNDERSTORMS MAY BE CAPABLE OF
PRODUCING SMALL HAIL AND GUSTY WINDS... ALTHOUGH ANEMIC SHEAR WILL
LIKELY PRECLUDE A WIDESPREAD SEVERE THREAT. IN ADDITION... A FEW
SHOWERS AND PERHAPS A RUMBLE OF THUNDER OR TWO WILL BE POSSIBLE AS
THE GUST FRONT MOVES THROUGH THE SOUTHERN ROLLING PLAINS THIS
MORNING THROUGH THE EARLY AFTERNOON AS WELL.
&&
.PREV DISCUSSION... /ISSUED 634 AM CDT WED JUL 24 2013/
AVIATION...
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. WEAK FRONTAL
BOUNDARY WILL SAG SOUTHWARD DURING THE DAY. THERE IS SOME RISK OF
TSTMS THIS AFTERNOON AND EVENING /THOUGH FAVORING KCDS/ AT BOTH
TERMINALS.
PREV DISCUSSION... /ISSUED 319 AM CDT WED JUL 24 2013/
SHORT TERM...
FLOW OVER THE CONUS THIS MORNING IS CHARACTERIZED BY LARGE SCALE
RIDGING OUT WEST AND TROUGHING ACROSS THE EAST. UPPER LEVEL HIGH
HAS EXPANDED OUR WAY A BIT MORE FOR TODAY WHICH WILL HELP TEMPS RISE
A FEW DEGREES. POLAR JET IS ORIENTED FROM SK TO TN. THE ASSOCIATED
H5 WIND MAX IS EXPECTED TO DRIVE FARTHER SOUTH A BIT TODAY TO
INCLUDE NWRN OK. AT THE SFC...A WEAK FRONTAL BOUNDARY IS SITUATED
ACROSS THE NORTHERN TX PANHANDLE AND IS CURRENTLY LITTLE MORE THAN
A WIND SHIFT LINE. FRONTOGENETICAL FORCING HAS BEEN INSUFFICIENT
THUS FAR IN INITIATING CONVECTION. NWP APPEARS FAIRLY CONSISTENT
IN PUSHING THIS BOUNDARY SLOWLY SOUTHWARD TODAY IN RESPONSE TO
ANEMIC EMBEDDED TROUGH WHICH IS EVIDENT AT H5. THE QUESTION IS
WHETHER DYNAMICAL PROCESSES WILL BE SUFFICIENT TO INITIATE
CONVECTION ACROSS OUR CWFA THIS AFTERNOON. WHILE OUR AREA IS ON
THE SUBSIDENT SIDE OF THE POLAR JET...AND SOME RESEMBLANCE OF A
CAP IS EVIDENT ON FCST SOUNDINGS...THE MERE PRESENCE OF THE
SURFACE CONVERGENCE WILL BE VERY HELPFUL IN HELPING TO REALIZE
TSTM DEVELOPMENT. WHILE BULK SHEAR IS QUITE WEAK...INSTABILITY MAY
BE SUFFICIENT FOR A FEW PULSE STRONG TO POSSIBLY SEVERE STORMS TO
DEVELOP WITH HAIL TO THE SIZE OF NICKELS AND GUSTS TO AROUND 60
MPH POSSIBLE IN ANY STORMS WHICH MANAGE TO BECOME ESTABLISHED.
STORM MOTION WILL BE QUITE SLOW (LESS THAN 10 MPH) AND THUS A FEW
LUCKY LOCATIONS MAY PICK UP A QUICK HALF INCH TO AN INCH.
HOWEVER...METEOROLOGICAL SCIENCE WITH THE OBSERVATIONAL NETWORK
AVAILABLE TODAY IS INSUFFICIENT TO US TO PINPOINT WHERE THAT MIGHT
BE OTHER THAN THE NORTHERN ZONES WILL HAVE THE BEST OPPORTUNITY
FOR RAIN.
LONG TERM...
THE EXTENDED FORECAST WILL START OFF WITH CHANCES FOR PRECIP
INITIALLY FOR THE SRN TX PANHANDLE/NORTHERN SOUTH PLAINS...THANKS TO
A 15-25 KT NOCTURNAL LLJ AND /MOST IMPORTANTLY/ A NRLY COLD FRONT
THAT WILL STALL ACROSS THE SRN TX PANHANDLE TONIGHT. THIS FRONT IS
IN ASSOCIATION WITH A SUBTLE SHORTWAVE PROGGED TO MOVE SE ACROSS THE
CENTRAL PLAINS. THE FRONT WILL LIKELY WASH OUT BY TOMORROW AFTN
DURING AT WHICH TIME THE CENTER OF THE UA RIDGE THAT WAS ONCE
OVERHEAD WOULD BE SOUTH OF THE REGION. AS SUCH...MONSOONAL STORM
ACTIVITY ACROSS E NM COULD SHIFT TO ACROSS WRN ZONES DUE TO ADEQUATE
SW STEERING FLOW.
THURSDAY NIGHT-FRIDAY CHANCES FOR RAINFALL COULD BECOME REALIZED FOR
THE REMAINDER OF THE CWA. A SHARPER SHORTWAVE TROUGH WILL BE
SKIRTING SE ACROSS THE CENTRAL PLAINS HEADING TOWARDS OKLAHOMA. THIS
WILL CAUSE THE UA RIDGE TO RETROGRADE JUST ENOUGH TO ALLOW FLOW
ALOFT TO VEER TO THE NW. ALTHOUGH THE BEST LIFT WILL BE WELL NE OF THE
REGION...THE FAVORABLE NW FLOW ALOFT WILL ENCOURAGE MOUNTAINOUS
PRECIP ACTIVITY TO TRANSLATE SE ACROSS THE SOUTHERN PLAINS.
THEREAFTER...A COLD FRONT WILL MOVE ACROSS THE ENTIRE CWFA FRIDAY
EVENING/NIGHT...HENCE BEING ANOTHER SOURCE OF PRECIP DEVELOPMENT AS
FRONTOGENETICAL FORCING WORKS WITH AN ENE UPSLOPE WIND COMPONENT.
PWATS ARE PROGGED TO INCREASE TO 1.20-1.80 INCHES AND MID-LEVEL CAPE
VALUES OF A FEW HUNDRED J/KG SUGGESTS THAT MODERATE RAINFALL AND
ISOLATED STRONG STORMS ARE PLAUSIBLE RESPECTIVELY. THIS
WEEKEND-EARLY NEXT WEEK...THE UA RIDGE ALBEIT FLATTENED...WILL MAKE
A RETURN TO THE SOUTHERN PLAINS THUS CAUSING INCREASING DIFFICULTY
IN STORM DEVELOPMENT /MID-LEVEL CAP WILL EXIST/. HOWEVER...ADEQUATE
SW MEAN FLOW COULD ONCE AGAIN URGE THE MONSOONAL MOISTURE
PLUME/PRECIP TO BEND ACROSS THE WRN AND NWRN ZONES. EARLY NEXT
WEEK-MID WEEK...LONG TERM SOLUTIONS HINT AT YET ANOTHER SHORTWAVE
TROUGH HAVING THE POTENTIAL TO TAKE THE EXACT SAME TRACK AS THE
ONE EXPECTED THURSDAY NIGHT-FRIDAY /PER THE GFS/ OR A BIT FARTHER
NE /PER THE ECMWF/. THIS WILL CAUSE THE UA RIDGE TO ONCE AGAIN
RETROGRADE AND PROMOTE NW FLOW ALOFT /MOVING STORMS OFF THE
MOUNTAINS AND TOWARDS THE FA/...NOT TO MENTION MAKING WAY FOR
ANOTHER FRONT AND ACCOMPANIED PRECIP. WILL HOLD OFF ON MENTIONABLE
POPS FOR NEXT WEEK AND AWAIT A CONSISTENT QPF SIGNAL.
TEMPS WILL COOL OFF INTO THE UPPER 80S TO LOWER 90S BY THE
WEEKEND...BUT WILL REBOUND BACK TO ABOVE NORM BY EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 68 91 66 87 65 / 30 20 20 20 20
TULIA 70 91 66 88 65 / 20 20 20 20 20
PLAINVIEW 70 92 67 89 66 / 20 20 20 20 20
LEVELLAND 71 95 68 92 67 / 20 20 20 20 20
LUBBOCK 71 95 70 93 68 / 20 20 20 20 20
DENVER CITY 71 96 68 94 67 / 30 20 20 20 20
BROWNFIELD 72 96 68 94 68 / 20 10 20 20 20
CHILDRESS 72 97 71 94 70 / 10 20 20 20 30
SPUR 74 97 70 95 71 / 20 10 20 20 20
ASPERMONT 74 99 72 97 72 / 20 10 10 20 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
16/23
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1055 PM CDT THU JUL 25 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 813 PM CDT THU JUL 25 2013
CONVECTION OVER CENTRAL AND EAST CENTRAL WISCONSIN HAS DIMINISHED
CONSIDERABLY...SO THE WATCH HAS BEEN CANCELED FOR THAT REGION.
STORMS...ISOLATE SVR...CONTINUE TO SLOWLY DEVELOP SOUTHWARD OVER
FAR NORTHERN WISCONSIN...AS THE UPPER TROUGH BUILDS SOUTHWARD AND
THE COLD FRONT WORKS INTO NORTHWEST WISCONSIN. STRONG STORMS WILL
WORK INTO NORTH CENTRAL IN AN HOUR OR SO. THE REST OF THE WATCH
WILL REMAIN INTACT. UPDATES OUT SOON.
UPDATE
ISSUED AT 700 PM CDT THU JUL 25 2013
INITIAL WATCH WAS MORE OF A CATCH ALL. PRIMARY FOCUS OF THE WATCH
WAS THE FROPA AND APPROACHING UPPER TROUGH FROM CANADA DROPPING
SOUTHWARD. SOME ISOLATED DAMAGING WINDS NOTED ALONG THE FRONT OVER
MINNESOTA. MUCH OF CENTRAL WAS ADDED FOR ONGOING CONVECTION OF
NEAR SEVERE HAIL REPORTS THE LAST FEW HOURS BUT PRIOR TO THE UPPER
TROUGH DROPPING SOUTH. STORMS OVER CENTRAL WISCONSIN SINCE 600 PM
HAVE DIMINISHED IN INTENSITY AND IF TRENDS CONTINUE NEXT HOUR OR
SO...MAY BE ABLE TO END THE WATCH OVER CENTRAL AND EAST CENTRAL
WISCONSIN BEFORE THE NEWS THIS EVENING.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE SITUATED OVER WESTERN LAKE SUPERIOR AND A WEAK FRONT
EXTENDING FROM IT INTO SOUTHWEST MINNESOTA. AHEAD OF THIS
FRONT...ML CAPES HAVE BEEN BUILDING ANYWHERE FROM 400 TO 1600
J/KG...WITH THE HIGHEST OCCURRING OVER SOUTH-CENTRAL MINNESOTA. A
MCV IS ALSO MOVING ESE OVER SOUTHERN MINNESOTA WITH SHOWERS AND SCT
THUNDERSTORMS DEVELOPING WITHIN THE INSTABILITY AXIS. TIMING OF
THESE SHOWERS INTO CENTRAL WISCONSIN IS AROUND 22Z. FURTHER
UPSTREAM...A STRONGER FRONT IS DIVING SOUTHEAST OVER NORTHERN
MINNESOTA AND NORTH DAKOTA WHERE SCT STORMS ARE ALSO OCCURRING. THE
MAIN FORECAST CONCERNS ARE SEVERE WEATHER THROUGH THIS
EVENING...FOLLOWED BY HEAVY RAIN POTENTIAL.
FOR THE REST OF THE AFTERNOON...ISOLATED SEVERE WEATHER LOOKS
POSSIBLE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON WITH FURTHER DESTABILIZATION AND INCOMING LIFT FROM THE MCV.
0-6KM BULK SHEAR VALUES ARE 30-35KTS AND 0-3KM STORM RELATIVE
HELICITIES ARE 150-200 M2/S2...WHICH INDICATES STORMS COULD GENERATE
MESOS. DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN
THREATS...WHICH WILL CARRY ON INTO THE EARLY EVENING HOURS.
TONIGHT...MCV OVER CENTRAL AND SOUTHERN MINNESOTA WILL CONTINUE ON
ITS TRAJECTORY TO THE ESE AND PASS OVER CENTRAL AND EAST CENTRAL
WISCONSIN THIS EVENING. SHOWERS AND THUNDERSTORMS LOOK LIKELY FOR
THE FIRST HALF OF THE EVENING OVER THESE AREAS. SCATTERED STORMS
WILL ALSO BE ONGOING OVER NORTH-WEST AND NORTH-CENTRAL WISCONSIN
AHEAD OF A WEAK COLD FRONT. THIS FRONT WILL GET OVER-TAKEN BY THE
STRONGER FRONT THAT LIES OVER THE NORTHERN PLAINS. AS THE STRONG
SHORTWAVE DIGS SOUTHEAST TONIGHT...FORCING WILL CONSOLIDATE AND ALSO
IMPROVE...SO THINK INITIAL SCT CONVECTION WILL BECOME MORE
WIDESPREAD OVER NORTHERN WISCONSIN THROUGH THE EVENING HOURS. THE
LLJ WILL THEN RAMP UP AHEAD OF THE FRONT OVERNIGHT AND PROVIDE
FURTHER FOCUS FOR CONVECTION...MAINLY FOR CENTRAL AND NORTHEAST
WISCONSIN. THOUGH ELEVATED CAPE IS RATHER MARGINAL FOR SEVERE
WEATHER LATE TONIGHT (UP TO 700 J/KG)...THINK SEVERE WEATHER WILL
HAVE THE MOST POTENTIAL LATER THIS AFTERNOON INTO THIS EVENING OVER
NORTH-CENTRAL WISCONSIN WHERE ML CAPES REACH AROUND 1400 J/KG AND
0-6KM BULK SHEAR VALUES ARE 30-35KTS. DAMAGING WINDS AND LARGE HAIL
WILL BE THE MAIN THREATS. THEN IT TURNS TO MORE OF A HEAVY RAIN
SCENARIO LATER TONIGHT DUE TO THE SLOW MOVING FRONT AND PWATS
CLIMBING TO 1.5 INCHES. LOWS RANGING FROM THE MID 50S NORTH TO MID
60S SOUTH.
FRIDAY...STRONG SHORTWAVE TROUGH WILL PIVOT ACROSS THE STATE AND
DRIVE AN ELONGATED SURFACE LOW OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN THROUGH MID-AFTERNOON BEFORE EXITING. AHEAD OF THE
ATTENDANT COLD FRONT...A 30-35KT LLJ WILL LIFT NORTHEAST ACROSS
NORTHEAST WISCONSIN AND PUSH PWATS UPWARDS OF 1.5 INCHES ACROSS
EASTERN PORTIONS OF THE STATE. WITH THE STRONG FORCING
ALOFT...WIDESPREAD SHOWERS AND THUNDERSTORMS LOOKS LIKE A DECENT BET
OVER NORTHEAST WISCONSIN FOR MUCH OF THE MORNING. OVER AN INCH OF
RAINFALL LOOKS POSSIBLE OVER CENTRAL AND NORTHEAST WISCONSIN TONIGHT
THROUGH MIDDAY FRIDAY. THERE MAY BE A LULL IN THE PRECIP FOR A FEW
HOURS OVER CENTRAL WISCONSIN...BUT WRAP AROUND MOISTURE AND
INCREASING INSTABILITY WITH THE COLD POOL ALOFT...WILL LIKELY LEAD
TO SCT SHOWERS RE-DEVELOPING. OVER NORTHERN WISCONSIN...GUSTY NORTH
WINDS WILL BE DEVELOPING AND CREATING UPSLOPE FLOW OFF LAKE
SUPERIOR. ALONG WITH SHARP CYCLONIC FLOW AND AMPLE MOISTURE THROUGH
THE COLUMN...SEEMS LIKE A DECENT RECIPE FOR NUMEROUS TO WIDESPREAD
SHOWER ACTIVITY. A RATHER RAW AND OVERCAST DAY WITH TEMPS
STRUGGLING TO REACH THE LOWER 60S NORTH AND THE LOWER 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
UPPER LOW IS FORECAST TO REMAIN OVER UPPER MICHIGAN
OR LAKE SUPERIOR THROUGH SUNDAY WITH MOSTLY DIURNAL SHOWERS AND
LOW TOP THUNDERSTORMS IN THE COLD CYCLONIC FLOW. 850MB
TEMPERATURES OF 2C TO 5C COMING ACROSS 10C LAKE SUPERIOR WATER
SHOULD PRODUCE LAKE EFFECT CLOUDS. 500MB TEMPERATURES FALL TO -18C
WHICH WILL CREATE VERY UNSTABLE CONDITIONS IN THE AFTERNOONS
SATURDAY AND SUNDAY. WOULD NOT DOUBT SOME GRAUPEL OR SMALL HAIL
WITH THE SCATTERED SHOWER OR THUNDERSTORMS. HIGHS SATURDAY AND
SUNDAY WILL BE 10 TO 15 DEGREES BELOW NORMAL THOUGH LOWS MAY NOT
BE QUITE A COLD DUE TO CLOUD COVER AND A BREEZE.
WEAK UPPER RIDGING ARRIVES MONDAY AND SHOULD KEEP THINGS DRY
THROUGH AT LEAST TUESDAY MORNING. THE MODELS THEN HAVE SIGNIFICANT DIFFERENCES
IN THE TIMING OF THE NEXT UPSTREAM UPPER TROUGHS SO WILL NOT MAKE
ANY MAJOR CHANCES RIGHT NOW. SURFACE TEMPERATURES SHOULD RISE TO
SEASONABLE LEVELS BY THE MIDDLE OF THE WEEK BEFORE TURNING COOLER
BY NEXT SATURDAY AS THE NEXT CANADIAN HIGH MOVES IN.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1052 PM CDT THU JUL 25 2013
SCATTERED SHOWERS AND ISOLATED STORMS WILL CONTINUE TO
TRACK OVER THE REGION FOR THE REST OF TONIGHT INTO FRIDAY. LINE OF
STORMS MAY BE MORE CONCENTRATED ALONG THE COLD FRONT PASSAGE MID
DAY FRIDAY. CYCLONIC FLOW WILL TEND TO KEEP MVFR CIGS AROUND OVER
AT LEAST NORTHERN WISCONSIN INTO FRIDAY EVENING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........TDH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
814 PM CDT THU JUL 25 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 813 PM CDT THU JUL 25 2013
CONVECTION OVER CENTRAL AND EAST CENTRAL WISCONSIN HAS DIMINISHED
CONSIDERABLY...SO THE WATCH HAS BEEN CANCELED FOR THAT REGION.
STORMS...ISOLATE SVR...CONTINUE TO SLOWLY DEVELOP SOUTHWARD OVER
FAR NORTHERN WISCONSIN...AS THE UPPER TROUGH BUILDS SOUTHWARD AND
THE COLD FRONT WORKS INTO NORTHWEST WISCONSIN. STRONG STORMS WILL
WORK INTO NORTH CENTRAL IN AN HOUR OR SO. THE REST OF THE WATCH
WILL REMAIN INTACT. UPDATES OUT SOON.
UPDATE
ISSUED AT 700 PM CDT THU JUL 25 2013
INITIAL WATCH WAS MORE OF A CATCH ALL. PRIMARY FOCUS OF THE WATCH
WAS THE FROPA AND APPROACHING UPPER TROUGH FROM CANADA DROPPING
SOUTHWARD. SOME ISOLATED DAMAGING WINDS NOTED ALONG THE FRONT OVER
MINNESOTA. MUCH OF CENTRAL WAS ADDED FOR ONGOING CONVECTION OF
NEAR SEVERE HAIL REPORTS THE LAST FEW HOURS BUT PRIOR TO THE UPPER
TROUGH DROPPING SOUTH. STORMS OVER CENTRAL WISCONSIN SINCE 600 PM
HAVE DIMINISHED IN INTENSITY AND IF TRENDS CONTINUE NEXT HOUR OR
SO...MAY BE ABLE TO END THE WATCH OVER CENTRAL AND EAST CENTRAL
WISCONSIN BEFORE THE NEWS THIS EVENING.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE SITUATED OVER WESTERN LAKE SUPERIOR AND A WEAK FRONT
EXTENDING FROM IT INTO SOUTHWEST MINNESOTA. AHEAD OF THIS
FRONT...ML CAPES HAVE BEEN BUILDING ANYWHERE FROM 400 TO 1600
J/KG...WITH THE HIGHEST OCCURRING OVER SOUTH-CENTRAL MINNESOTA. A
MCV IS ALSO MOVING ESE OVER SOUTHERN MINNESOTA WITH SHOWERS AND SCT
THUNDERSTORMS DEVELOPING WITHIN THE INSTABILITY AXIS. TIMING OF
THESE SHOWERS INTO CENTRAL WISCONSIN IS AROUND 22Z. FURTHER
UPSTREAM...A STRONGER FRONT IS DIVING SOUTHEAST OVER NORTHERN
MINNESOTA AND NORTH DAKOTA WHERE SCT STORMS ARE ALSO OCCURRING. THE
MAIN FORECAST CONCERNS ARE SEVERE WEATHER THROUGH THIS
EVENING...FOLLOWED BY HEAVY RAIN POTENTIAL.
FOR THE REST OF THE AFTERNOON...ISOLATED SEVERE WEATHER LOOKS
POSSIBLE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON WITH FURTHER DESTABILIZATION AND INCOMING LIFT FROM THE MCV.
0-6KM BULK SHEAR VALUES ARE 30-35KTS AND 0-3KM STORM RELATIVE
HELICITIES ARE 150-200 M2/S2...WHICH INDICATES STORMS COULD GENERATE
MESOS. DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN
THREATS...WHICH WILL CARRY ON INTO THE EARLY EVENING HOURS.
TONIGHT...MCV OVER CENTRAL AND SOUTHERN MINNESOTA WILL CONTINUE ON
ITS TRAJECTORY TO THE ESE AND PASS OVER CENTRAL AND EAST CENTRAL
WISCONSIN THIS EVENING. SHOWERS AND THUNDERSTORMS LOOK LIKELY FOR
THE FIRST HALF OF THE EVENING OVER THESE AREAS. SCATTERED STORMS
WILL ALSO BE ONGOING OVER NORTH-WEST AND NORTH-CENTRAL WISCONSIN
AHEAD OF A WEAK COLD FRONT. THIS FRONT WILL GET OVER-TAKEN BY THE
STRONGER FRONT THAT LIES OVER THE NORTHERN PLAINS. AS THE STRONG
SHORTWAVE DIGS SOUTHEAST TONIGHT...FORCING WILL CONSOLIDATE AND ALSO
IMPROVE...SO THINK INITIAL SCT CONVECTION WILL BECOME MORE
WIDESPREAD OVER NORTHERN WISCONSIN THROUGH THE EVENING HOURS. THE
LLJ WILL THEN RAMP UP AHEAD OF THE FRONT OVERNIGHT AND PROVIDE
FURTHER FOCUS FOR CONVECTION...MAINLY FOR CENTRAL AND NORTHEAST
WISCONSIN. THOUGH ELEVATED CAPE IS RATHER MARGINAL FOR SEVERE
WEATHER LATE TONIGHT (UP TO 700 J/KG)...THINK SEVERE WEATHER WILL
HAVE THE MOST POTENTIAL LATER THIS AFTERNOON INTO THIS EVENING OVER
NORTH-CENTRAL WISCONSIN WHERE ML CAPES REACH AROUND 1400 J/KG AND
0-6KM BULK SHEAR VALUES ARE 30-35KTS. DAMAGING WINDS AND LARGE HAIL
WILL BE THE MAIN THREATS. THEN IT TURNS TO MORE OF A HEAVY RAIN
SCENARIO LATER TONIGHT DUE TO THE SLOW MOVING FRONT AND PWATS
CLIMBING TO 1.5 INCHES. LOWS RANGING FROM THE MID 50S NORTH TO MID
60S SOUTH.
FRIDAY...STRONG SHORTWAVE TROUGH WILL PIVOT ACROSS THE STATE AND
DRIVE AN ELONGATED SURFACE LOW OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN THROUGH MID-AFTERNOON BEFORE EXITING. AHEAD OF THE
ATTENDANT COLD FRONT...A 30-35KT LLJ WILL LIFT NORTHEAST ACROSS
NORTHEAST WISCONSIN AND PUSH PWATS UPWARDS OF 1.5 INCHES ACROSS
EASTERN PORTIONS OF THE STATE. WITH THE STRONG FORCING
ALOFT...WIDESPREAD SHOWERS AND THUNDERSTORMS LOOKS LIKE A DECENT BET
OVER NORTHEAST WISCONSIN FOR MUCH OF THE MORNING. OVER AN INCH OF
RAINFALL LOOKS POSSIBLE OVER CENTRAL AND NORTHEAST WISCONSIN TONIGHT
THROUGH MIDDAY FRIDAY. THERE MAY BE A LULL IN THE PRECIP FOR A FEW
HOURS OVER CENTRAL WISCONSIN...BUT WRAP AROUND MOISTURE AND
INCREASING INSTABILITY WITH THE COLD POOL ALOFT...WILL LIKELY LEAD
TO SCT SHOWERS RE-DEVELOPING. OVER NORTHERN WISCONSIN...GUSTY NORTH
WINDS WILL BE DEVELOPING AND CREATING UPSLOPE FLOW OFF LAKE
SUPERIOR. ALONG WITH SHARP CYCLONIC FLOW AND AMPLE MOISTURE THROUGH
THE COLUMN...SEEMS LIKE A DECENT RECIPE FOR NUMEROUS TO WIDESPREAD
SHOWER ACTIVITY. A RATHER RAW AND OVERCAST DAY WITH TEMPS
STRUGGLING TO REACH THE LOWER 60S NORTH AND THE LOWER 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
UPPER LOW IS FORECAST TO REMAIN OVER UPPER MICHIGAN
OR LAKE SUPERIOR THROUGH SUNDAY WITH MOSTLY DIURNAL SHOWERS AND
LOW TOP THUNDERSTORMS IN THE COLD CYCLONIC FLOW. 850MB
TEMPERATURES OF 2C TO 5C COMING ACROSS 10C LAKE SUPERIOR WATER
SHOULD PRODUCE LAKE EFFECT CLOUDS. 500MB TEMPERATURES FALL TO -18C
WHICH WILL CREATE VERY UNSTABLE CONDITIONS IN THE AFTERNOONS
SATURDAY AND SUNDAY. WOULD NOT DOUBT SOME GRAUPEL OR SMALL HAIL
WITH THE SCATTERED SHOWER OR THUNDERSTORMS. HIGHS SATURDAY AND
SUNDAY WILL BE 10 TO 15 DEGREES BELOW NORMAL THOUGH LOWS MAY NOT
BE QUITE A COLD DUE TO CLOUD COVER AND A BREEZE.
WEAK UPPER RIDGING ARRIVES MONDAY AND SHOULD KEEP THINGS DRY
THROUGH AT LEAST TUESDAY MORNING. THE MODELS THEN HAVE SIGNIFICANT DIFFERENCES
IN THE TIMING OF THE NEXT UPSTREAM UPPER TROUGHS SO WILL NOT MAKE
ANY MAJOR CHANCES RIGHT NOW. SURFACE TEMPERATURES SHOULD RISE TO
SEASONABLE LEVELS BY THE MIDDLE OF THE WEEK BEFORE TURNING COOLER
BY NEXT SATURDAY AS THE NEXT CANADIAN HIGH MOVES IN.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 525 PM CDT THU JUL 25 2013
SHOWERS AND STORMS WILL BE ON THE INCREASE TONIGHT AS
A LOW PRESSURE DEVELOPS AND DEEPENS OVER NORTHERN WISCONSIN BY
FRIDAY MORNING. SHOWERS AND STORMS EXPECTED TO PRODUCE WIDESPREAD
MVFR CIGS AND VSBYS LATE TONIGHT INTO FRIDAY MORNING ALONG WITH
SCATTERED AREAS OF IFR CIGS FRIDAY MORNING. A LITTLE DRIER AIR ON
NORTHWEST WINDS WORKING INTO PARTS OF CENTRAL AND EAST CENTRAL
WISCONSIN LATER FRIDAY MAY RAISE CIGS TO VFR LEVELS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........TDH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......TDH
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
702 PM CDT THU JUL 25 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 700 PM CDT THU JUL 25 2013
INITIAL WATCH WAS MORE OF A CATCH ALL. PRIMARY FOCUS OF THE WATCH
WAS THE FROPA AND APPROACHING UPPER TROUGH FROM CANADA DROPPING
SOUTHWARD. SOME ISOLATED DAMAGING WINDS NOTED ALONG THE FRONT OVER
MINNESOTA. MUCH OF CENTRAL WAS ADDED FOR ONGOING CONVECTION OF
NEAR SEVERE HAIL REPORTS THE LAST FEW HOURS BUT PRIOR TO THE UPPER
TROUGH DROPPING SOUTH. STORMS OVER CENTRAL WISCONSIN SINCE 600 PM
HAVE DIMINISHED IN INTENSITY AND IF TRENDS CONTINUE NEXT HOUR OR
SO...MAY BE ABLE TO END THE WATCH OVER CENTRAL AND EAST CENTRAL
WISCONSIN BEFORE THE NEWS THIS EVENING.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN AREA OF LOW
PRESSURE SITUATED OVER WESTERN LAKE SUPERIOR AND A WEAK FRONT
EXTENDING FROM IT INTO SOUTHWEST MINNESOTA. AHEAD OF THIS
FRONT...ML CAPES HAVE BEEN BUILDING ANYWHERE FROM 400 TO 1600
J/KG...WITH THE HIGHEST OCCURRING OVER SOUTH-CENTRAL MINNESOTA. A
MCV IS ALSO MOVING ESE OVER SOUTHERN MINNESOTA WITH SHOWERS AND SCT
THUNDERSTORMS DEVELOPING WITHIN THE INSTABILITY AXIS. TIMING OF
THESE SHOWERS INTO CENTRAL WISCONSIN IS AROUND 22Z. FURTHER
UPSTREAM...A STRONGER FRONT IS DIVING SOUTHEAST OVER NORTHERN
MINNESOTA AND NORTH DAKOTA WHERE SCT STORMS ARE ALSO OCCURRING. THE
MAIN FORECAST CONCERNS ARE SEVERE WEATHER THROUGH THIS
EVENING...FOLLOWED BY HEAVY RAIN POTENTIAL.
FOR THE REST OF THE AFTERNOON...ISOLATED SEVERE WEATHER LOOKS
POSSIBLE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN LATER THIS
AFTERNOON WITH FURTHER DESTABILIZATION AND INCOMING LIFT FROM THE MCV.
0-6KM BULK SHEAR VALUES ARE 30-35KTS AND 0-3KM STORM RELATIVE
HELICITIES ARE 150-200 M2/S2...WHICH INDICATES STORMS COULD GENERATE
MESOS. DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN
THREATS...WHICH WILL CARRY ON INTO THE EARLY EVENING HOURS.
TONIGHT...MCV OVER CENTRAL AND SOUTHERN MINNESOTA WILL CONTINUE ON
ITS TRAJECTORY TO THE ESE AND PASS OVER CENTRAL AND EAST CENTRAL
WISCONSIN THIS EVENING. SHOWERS AND THUNDERSTORMS LOOK LIKELY FOR
THE FIRST HALF OF THE EVENING OVER THESE AREAS. SCATTERED STORMS
WILL ALSO BE ONGOING OVER NORTH-WEST AND NORTH-CENTRAL WISCONSIN
AHEAD OF A WEAK COLD FRONT. THIS FRONT WILL GET OVER-TAKEN BY THE
STRONGER FRONT THAT LIES OVER THE NORTHERN PLAINS. AS THE STRONG
SHORTWAVE DIGS SOUTHEAST TONIGHT...FORCING WILL CONSOLIDATE AND ALSO
IMPROVE...SO THINK INITIAL SCT CONVECTION WILL BECOME MORE
WIDESPREAD OVER NORTHERN WISCONSIN THROUGH THE EVENING HOURS. THE
LLJ WILL THEN RAMP UP AHEAD OF THE FRONT OVERNIGHT AND PROVIDE
FURTHER FOCUS FOR CONVECTION...MAINLY FOR CENTRAL AND NORTHEAST
WISCONSIN. THOUGH ELEVATED CAPE IS RATHER MARGINAL FOR SEVERE
WEATHER LATE TONIGHT (UP TO 700 J/KG)...THINK SEVERE WEATHER WILL
HAVE THE MOST POTENTIAL LATER THIS AFTERNOON INTO THIS EVENING OVER
NORTH-CENTRAL WISCONSIN WHERE ML CAPES REACH AROUND 1400 J/KG AND
0-6KM BULK SHEAR VALUES ARE 30-35KTS. DAMAGING WINDS AND LARGE HAIL
WILL BE THE MAIN THREATS. THEN IT TURNS TO MORE OF A HEAVY RAIN
SCENARIO LATER TONIGHT DUE TO THE SLOW MOVING FRONT AND PWATS
CLIMBING TO 1.5 INCHES. LOWS RANGING FROM THE MID 50S NORTH TO MID
60S SOUTH.
FRIDAY...STRONG SHORTWAVE TROUGH WILL PIVOT ACROSS THE STATE AND
DRIVE AN ELONGATED SURFACE LOW OVER NORTH-CENTRAL AND NORTHEAST
WISCONSIN THROUGH MID-AFTERNOON BEFORE EXITING. AHEAD OF THE
ATTENDANT COLD FRONT...A 30-35KT LLJ WILL LIFT NORTHEAST ACROSS
NORTHEAST WISCONSIN AND PUSH PWATS UPWARDS OF 1.5 INCHES ACROSS
EASTERN PORTIONS OF THE STATE. WITH THE STRONG FORCING
ALOFT...WIDESPREAD SHOWERS AND THUNDERSTORMS LOOKS LIKE A DECENT BET
OVER NORTHEAST WISCONSIN FOR MUCH OF THE MORNING. OVER AN INCH OF
RAINFALL LOOKS POSSIBLE OVER CENTRAL AND NORTHEAST WISCONSIN TONIGHT
THROUGH MIDDAY FRIDAY. THERE MAY BE A LULL IN THE PRECIP FOR A FEW
HOURS OVER CENTRAL WISCONSIN...BUT WRAP AROUND MOISTURE AND
INCREASING INSTABILITY WITH THE COLD POOL ALOFT...WILL LIKELY LEAD
TO SCT SHOWERS RE-DEVELOPING. OVER NORTHERN WISCONSIN...GUSTY NORTH
WINDS WILL BE DEVELOPING AND CREATING UPSLOPE FLOW OFF LAKE
SUPERIOR. ALONG WITH SHARP CYCLONIC FLOW AND AMPLE MOISTURE THROUGH
THE COLUMN...SEEMS LIKE A DECENT RECIPE FOR NUMEROUS TO WIDESPREAD
SHOWER ACTIVITY. A RATHER RAW AND OVERCAST DAY WITH TEMPS
STRUGGLING TO REACH THE LOWER 60S NORTH AND THE LOWER 70S SOUTH.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 231 PM CDT THU JUL 25 2013
UPPER LOW IS FORECAST TO REMAIN OVER UPPER MICHIGAN
OR LAKE SUPERIOR THROUGH SUNDAY WITH MOSTLY DIURNAL SHOWERS AND
LOW TOP THUNDERSTORMS IN THE COLD CYCLONIC FLOW. 850MB
TEMPERATURES OF 2C TO 5C COMING ACROSS 10C LAKE SUPERIOR WATER
SHOULD PRODUCE LAKE EFFECT CLOUDS. 500MB TEMPERATURES FALL TO -18C
WHICH WILL CREATE VERY UNSTABLE CONDITIONS IN THE AFTERNOONS
SATURDAY AND SUNDAY. WOULD NOT DOUBT SOME GRAUPEL OR SMALL HAIL
WITH THE SCATTERED SHOWER OR THUNDERSTORMS. HIGHS SATURDAY AND
SUNDAY WILL BE 10 TO 15 DEGREES BELOW NORMAL THOUGH LOWS MAY NOT
BE QUITE A COLD DUE TO CLOUD COVER AND A BREEZE.
WEAK UPPER RIDGING ARRIVES MONDAY AND SHOULD KEEP THINGS DRY
THROUGH AT LEAST TUESDAY MORNING. THE MODELS THEN HAVE SIGNIFICANT DIFFERENCES
IN THE TIMING OF THE NEXT UPSTREAM UPPER TROUGHS SO WILL NOT MAKE
ANY MAJOR CHANCES RIGHT NOW. SURFACE TEMPERATURES SHOULD RISE TO
SEASONABLE LEVELS BY THE MIDDLE OF THE WEEK BEFORE TURNING COOLER
BY NEXT SATURDAY AS THE NEXT CANADIAN HIGH MOVES IN.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 525 PM CDT THU JUL 25 2013
SHOWERS AND STORMS WILL BE ON THE INCREASE TONIGHT AS
A LOW PRESSURE DEVELOPS AND DEEPENS OVER NORTHERN WISCONSIN BY
FRIDAY MORNING. SHOWERS AND STORMS EXPECTED TO PRODUCE WIDESPREAD
MVFR CIGS AND VSBYS LATE TONIGHT INTO FRIDAY MORNING ALONG WITH
SCATTERED AREAS OF IFR CIGS FRIDAY MORNING. A LITTLE DRIER AIR ON
NORTHWEST WINDS WORKING INTO PARTS OF CENTRAL AND EAST CENTRAL
WISCONSIN LATER FRIDAY MAY RAISE CIGS TO VFR LEVELS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........TDH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
638 PM CDT THU JUL 25 2013
.SHORT TERM...(TONIGHT AND FRIDAY)
ISSUED AT 332 PM CDT THU JUL 25 2013
MAIN FORECAST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES THRU THE
PERIOD...POTENTIAL FOR STRONG/SEVERE STORMS THRU THIS EVENING.
18Z DATA ANALYSIS HAD A BROAD AREA OF LOW PRESSURE OVER THE NORTHERN
PLAINS/WESTERN GREAT LAKES WITH CENTERS NEAR KDLH...MAN/MN BORDER
AND CENTRAL SD. MAIN COLD FRONT APPEARED TO BE LOCATED NEAR THE
ND/MN BORDER TO EASTERN SD WITH A LEAD TROUGH/FRONT FROM THE KDLH
LOW CENTER TO KMSP AND FAR NORTHWEST IA. LAPS ANALYSIS SHOWED CAPE
CONTINUING TO BUILD FROM NORTHWEST WI TO EASTERN SD AS TEMPS CLIMB
INTO THE MID/UPPER 70S AND DEW POINTS RISE INTO THE MID 60S AHEAD
OF THE FRONTS/TROUGH. CONVECTION DEVELOPING RATHER RAPIDLY AS OF
18Z ALONG AND ARC FROM FAR NORTHEAST IA TO THE MN RIVER VALLEY
ACROSS SOUTHERN MN...AHEAD OF THE WEAK SHORTWAVES AND ON THE EDGE
OF THE STRONGER LOWER LEVEL MOISTURE TRANSPORT.
NO MAJOR PROBLEMS NOTED WITH 25.12Z MODEL INITIALIZATIONS. LESSER
DIFFERENCES INCLUDE GFS ON THE HIGH SIDE WITH SFC DEW POINTS OVER
MUCH OF MN/IA/WI WHILE STRONGER GEM/ECMWF LOOKED BETTER WITH THE
SHORTWAVE NEAR LK WINNIPEG. DPROG/DT OF 500MB HGTS AT 25.12Z SHOWED
THE MODEL RUNS OF 23.12Z AND 24.12Z VERIFIED REASONABLY WELL ACROSS
NOAM/EASTERN PAC BUT ALL WERE A BIT WEAK WITH THE SHORTWAVE NEAR LK
WINNIPEG. TREND REMAINS STRONGER WITH CONTINUING EMERGING DETAILS
AS THE SOUTH-CENTRAL CAN SHORTWAVES ROTATE SOUTHEAST AND INTO THE
UPPER MIDWEST TONIGHT/FRI...CARVING OUT A MID LEVEL LOW OVER LK
SUPERIOR BY 00Z SAT. TREND REMAINS STRONGER WITH THE SHORTWAVES AND
SOUTHWARD WITH THE MID LEVEL LOW AT 00Z SAT. GOOD BETWEEN MODEL
CONSISTENCY TONIGHT/FRI...EVEN WITH THE STRONGER TREND ON THE
SHORTWAVES TO IMPACT THE AREA. CHECK OF OBS VS. MODEL DATA AT 18Z
SHOWED ALL TO BE REASONABLE ON THE CENTRAL CONUS MASS FIELDS.
DRIER OF MODELS A BIT BETTER WITH DEW POINTS AHEAD OF THE APPROACHING
TROUGHS/FRONTS. PER WV IMAGERY...STRONGER OF MODELS LOOKED BETTER
WITH THE SHORTWAVE OVER SOUTHERN MAN/SASKAT AND WITH THE SHORT-
WAVE OVER EASTERN SD. NO CLEAR MODEL FAVORITE AND WILL SIDE WITH A
MODEL/ENSEMBLE CONSENSUS...WITH SHORT-TERM FCST CONFIDENCE ON THE
GOOD SIDE.
IN THE SHORT TERM...SHORT TERM FCST JUST BEGINNING TO COME INTO
FOCUS AS CONVECTION DEVELOPS EARLY THIS AFTERNOON IN/WEST OF THE FCST
AREA. EVEN THOUGH 25.12Z MODELS VERY SIMILAR AT/ABOVE 700MB...
DETAIL/MESO-SCALE DIFFERENCES IN THE SFC-850MB LAYER CONTINUED TO
PRODUCE A VARIETY CONVECTIVE OUTCOMES AS THE SFC TROUGH/FRONTS AND
SHORTWAVES ROTATED ACROSS THE AREA LATE THIS AFTERNOON THRU FRI.
ONE STRONGER SURGE OF LOWER LEVEL THERMO-DYNAMIC FORCING WITH/AHEAD
OF THE SFC-850MB FRONTS ROTATES ACROSS THE AREA THIS AFTERNOON/
EVENING. ML CAPES IN THE 1K TO 2K J/KG RANGE WITH INCREASING 0-
6KM SHEAR DEVELOP ACROSS THE AREA INTO THE EARLY EVENING HOURS.
MODEL SOUNDINGS SHOWING MINIMAL CAPPING ACROSS SOUTHERN MN/NORTHERN
IA/WESTERN WI IN THE AIRMASS AHEAD OF THE FRONTS. APPEARS MAIN
SEVERE THREAT WILL BE THIS AFTERNOON INTO EARLY THIS EVENING. LACK
OF CAPPING SHOULD ALLOW CONVECTION TO FIRE AND BECOME RATHER
WIDESPREAD...WITH MANY TSRA COMPETING FOR THE INSTABILITY AND
INFLOW BEFORE TOO LONG. THIS LOOKS TO BE OCCURRING WITH CONVECTION
DEVELOPING EARLY THIS AFTERNOON. APPROACHING SHORTWAVES FROM THE
WEST SHOULD AID CONVECTION INTO EVENING HOURS AS THEY MOVE EAST.
CONTINUED THE 70-80 PERCENT SHRA/TSRA CHANCES THIS EVENING...
TAPERING OFF/MOVING EAST AFTER MIDNIGHT AS THE LEAD FRONT AND THE
SHORTWAVES FROM SD MOVE EAST OF THE AREA.
STRONGER DYNAMIC FORCING/LIFT/DIVERGENCE ALOFT AND SOME 850-500MB FN
CONVERGENCE MOVE SOUTHEAST ACROSS FCST AREA FRI MORNING AS THE
MANITOBA/SASKAT SHORTWAVES MERGE AND DROP ACROSS THE AREA. RATHER
IMPRESSIVE 500-300MB PV ADVECTION MOVES ACROSS THE FCST AREA FRI
MORNING. SOME WEAK INSTABILITY PROGGED TO LINGER FRI...ESPECIALLY
OVER THE SOUTHEAST HALF OF THE FCST AREA WITH PW VALUES REMAINING
AS HIGH AS 0.75 TO 1 INCH BEHIND THE SECOND/MAIN COLD FRONT WHICH
PASSES FRI MORNING. MID LEVEL COOLING WITH THE APPROACHING 500MB
TROUGH KEEPS THE AIRMASS RELATIVELY UNCAPPED THRU EARLY AFTERNOON
FRI. RAISED SHRA/TSRA CHANCE OVER MOST OF THE FCST AREA DURING
THE LATER MORNING/EARLY AFTERNOON HOURS AS SHORTWAVE/STRONG PV
ADVECTION MOVE ACROSS THE AREA. BY LATER FRI AFTERNOON/EVENING THE
INCREASED 925-700MB DEFORMATION BAND MOISTURE WRAPS SOUTHEAST
ACROSS THE AREA BEHIND THE LOW IN/UNDER THE STRONG/DEEP CYCLONIC
FLOW. CONTINUED A SMALL SHRA CHANCE...MAINLY ACROSS THE NORTH/EAST
ENDS OF THE FCST INTO FRI EVENING. USED A BLEND OF NUMERICAL
GUIDANCE FOR LOWS TONIGHT. HIGHS FRI LOOKING TO BE LATE MORNING/
EARLY AFTERNOON THEN STEADY/SLOWLY FALL DURING THE AFTERNOON IN
STRONGER POST-FRONTAL COLD ADVECTION.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 PM CDT THU JUL 25 2013
MAIN FORECAST CONCERNS IN THE FRI NIGHT THRU SUN NIGHT PERIOD ARE
COLD POOL SHRA SAT/SUN AFTERNOONS AND COOL...AUTUMN-LIKE TEMPS THRU
THE PERIOD.
25.12Z MODELS REMAIN IN GOOD AGREEMENT AS THE COLD CORE MID LEVEL LOW
WOBBLES OVER LK SUPERIOR/U.P OF MI FRI NIGHT THRU SAT NIGHT THEN
SLOWLY PROGRESSES EAST SUN/SUN NIGHT. TREND IS SLOWER/FURTHER SOUTH
WITH THE LOCATION/PROGRESSION OF THIS LOW THRU THE PERIOD...KEEPING
THE AREA COOL NORTHWEST TO NORTH FLOW ALOFT. GIVEN THE GOOD/TIGHT
MODEL CONSENSUS THRU THE PERIOD...FCST CONFIDENCE FOR FRI NIGHT
THRU SUN NIGHT REMAINS GOOD.
SEASONABLY COLD AIRMASS AND DEEP CYCLONIC FLOW CONTINUE TO SETTLE
ACROSS WI AND MUCH OF MN/IA FRI NIGHT/SAT. COLDEST OF THE 925-850MB
AIRMASS MOVES ACROSS THE AREA LATE FRI NIGHT/SAT MORNING...WITH
850MB TEMPS IN THE +3C TO +6C RANGE AT MORNING. THIS SOME 2 TO 2.5
STANDARD DEVIATIONS BELOW THE NORMALS FOR LATE JULY. MODEL SOUNDING
SHOWING STEEP LOW LEVEL LAPSE RATES WITH MIXING TO 850MB SAT
AFTERNOON. WITH TEMPS IN THE LOW-MID 60S SAT AFTERNOON MODELS
PRODUCING SOME WEAK CAPE TO 800-700MB. WITH THE SFC-500MB CYCLONIC
FLOW/CONVERGENCE AND SOME MODEST 925-700MB WRAP-AROUND MOISTURE TO
ROTATE ACROSS MAINLY THE NORTHEAST HALF OF THE FCST AREA...
CONTINUED/ADDED A SMALL SHRA CHANCE ACROSS THE NORTHEAST END OF THE
FCST AREA SAT AFTERNOON/EARLY SAT EVENING. COOL NORTHERLY FLOW...
PLENTY OF DIURNAL CU/STRATO-CU WILL HOLD TEMPS DOWN ON SAT...IN
THE MID 60S-LOW 70S...NEAR RECORD LOW HIGHS FOR THE DATE. SOME
MOISTURE/CLOUDS LINGER SAT NIGHT. WITH THE SLOWER EASTWARD PROGRESS
OF THE SFC-MID LEVEL LOW...SOME GRADIENT WINDS REMAIN OVER THE AREA
SAT NIGHT...WITH TEMPS OVER THE NORTHEAST END OF THE FCST AREA NOT
EXPECT TO BOTTOM OUT AS MUCH AS EARLIER EXPECTED.
MID LEVEL LOW MOVES SLOWLY EAST OF THE AREA SUN/SUN NIGHT...
TAKING THE COLDEST 925-700MB AIR AND MOST OF THE LOW LEVEL MOISTURE
WITH IT. TEMPS TO SLOWLY MODERATE SUNDAY WITH MORE SUNSHINE AND
THE WARMING 925-850MB AIRMASS. COLDER LOWS MAY ACTUALLY BE SUN
NIGHT WITH A DRIER AIRMASS AND THE SFC RIDGE AXIS DRIFTING OVER
THE UPPER MIDWEST. LOWERED LOWS SUN NIGHT...ESPECIALLY THE LOWER
LAYING AREAS ALONG/NORTHEAST OF I-94. GENERALLY FAVORED COOLER OF
GUIDANCE LOWS/HIGHS FOR FRI NIGHT THRU SUN NIGHT.
25.00Z MEDIUM RANGE MODELS IN IMPROVING AGREEMENT MON/TUE AS THE MID
LEVEL LOW EAST OF LK SUPERIOR CONTINUES EAST AWAY FROM THE REGION.
TREND FAVORS SLOWER OF EARLIER RUNS WITH THIS. ONCE THE LOW EXITS
THE FLOW BECOMES QUASI-ZONAL ACROSS THE NORTHERN CONUS FOR MUCH OF
NEXT WEEK. FCST BECOMES MORE UNCERTAIN WED/THU AS MODELS STRUGGLE
WITH TIMING OF STRONGER/TRACKABLE SHORTWAVES THRU THE FLOW. MODEL
TIMING DIFFERENCES COMMON WITH QUASI-ZONAL FLOW AND SHORTWAVE
TIMING IN THE DAY 4-7 TIME-FRAME. RUN-TO-RUN CONSISTENCY IN THE TUE-
THU PERIOD OF LITTLE HELP DETERMINING WHICH OF THE DETERMINISTIC
MODELS MAY BE MORE CORRECT AS THEY ALL SHOW SOME VARIABILITY. THUS
WILL CONTINUE TO FAVOR A MODEL/ENSEMBLE CONSENSUS IN THE DAY 4-7
PERIOD UNTIL THE DETAILS BECOME CLEARER AND MODELS SETTLE ON A
MORE COMMON SOLUTION WITH SHORTWAVES IN THE FLOW. GIVEN THE
DIFFERENCES...FCST CONFIDENCE IN THE DAY 4-7 PERIOD AVERAGE.
WITH THE ONTARIO MID LEVEL LOW DEPARTING...HGTS RISE OVER THE REGION
AND ALLOWS THE NEXT SHORTWAVE THRU THE FLOW TO APPROACH. QUESTION
BY MON IS HOW QUICKLY THE MOISTURE RETURNS. A SEASONABLY STRONG
BAROCLINIC ZONE LOOKS TO BE OVER THE REGION MON...TO LIFT ANY MOISTURE
BEING ADVECTED INTO THE AREA. SMALL SHRA/TSRA CHANCE ACROSS MAINLY
THE SOUTHWEST HALF OF THE FCST AREA MON AFTERNOON LOOKS REASONABLE.
AFTER MON...TIMING DIFFERENCES AMONG THE MODELS WITH THE SHORTWAVES
THRU THE FLOW COME INTO PLAY. GIVEN THE MODEL DIFFERENCES...EACH
SPREADS A COUPLE ROUNDS OF FORCING/LIFT AND MOISTURE TRANSPORT INTO
THE AREA AT SOME POINT FROM MON NIGHT THRU THU. LOWER CONFIDENCE IN
THE DAY 5-7 PERIOD AS TO WHICH TIMING IS MORE CORRECT THAN THE
OTHERS...SO WILL LEAVE THE SMALL MODEL/ENSEMBLE CONSENSUS SHRA/TSRA
CHANCES FOR TUE THRU THU AS IS. AGAIN NOT EACH PERIOD WILL END UP
WITH SHRA/TSRA CHANCES AS TIMING DETAILS EVENTUALLY BECOME CLEARER.
WITH THE TRANSITION TO MORE WESTERLY FLOW...TEMPERATURES SLOWLY
RETURN TO NEAR NORMAL THRU NEXT WEEK. MODEL/ENSEMBLE CONSENSUS LOOKS
TO HAVE HIGHS/LOWS FOR MON-THU WELL TRENDED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 638 PM CDT THU JUL 25 2013
INITIAL ROUND OF CONVECTION HAS PASSED THROUGH BOTH TAF SITES WITH
SOME LINGERING SHOWERS STILL IN THE AREA SO WILL START WITH A
VCSH. THE QUESTION BECOMES WHETHER THERE WILL BE MORE DEVELOPMENT
THROUGH THE EVENING AS THE COLD FRONT MOVES INTO THE AREA. THE
FRONT PRESENTLY EXTENDS FROM NORTHEAST MINNESOTA INTO NEBRASKA.
LAPS SB CAPE ANALYSIS AT 25.22Z INDICATES A NARROW CORRIDOR OF
1000 J/KG AHEAD OF THE FRONT WITH VERY LITTLE LEFT OVER THE
FORECAST AREA AS THE ONGOING CONVECTION USED IT UP. VARIOUS MESO
MODELS INCLUDING THE 25.12Z HI-RES ARW...25.21Z HRRR AND 25.20Z
ARXLAPS SHOW ACTIVITY DEVELOPING ALONG THE FRONT AND THEN
DISSIPATING AS IT MOVES INTO THE AREA WHERE THE CAPE HAS ALREADY
BEEN USED UP. THIS SEEMS VERY REASONABLE AND PLAN TO ONLY CARRY
THE VCSH UP TO 04Z AT THIS TIME. SOME CONCERN FOR FOG OVERNIGHT
WITH THE RAIN AND IF ANY CLEARING CAN TAKE PLACE...SO WILL
INCLUDE A TEMPO GROUP FOR BOTH SITES WITH SOME MVFR VISIBILITY.
THE WINDS SHOULD COME AROUND TO THE NORTHWEST WITH THE PASSAGE OF
THE FRONT FRIDAY MORNING. THE MAIN SHORT WAVE TROUGH WILL ALSO BE
COMING THROUGH FRIDAY TO PROVIDE SOME LIFT AND WITH CYCLONIC FLOW
ALOFT...SHOULD SEE SOME SCATTERED SHOWERS DEVELOP...ESPECIALLY
EAST OF THE MISSISSIPPI RIVER. WILL INCLUDE A VCSH FOR KLSE FRIDAY
AFTERNOON BUT WILL LOWER CHANCES AT KRST WILL NOT SHOW ANY CHANCE
OF RAIN AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
559 PM CDT WED JUL 24 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 312 PM CDT WED JUL 24 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW WEAK HIGH
PRESSURE STRETCHING FROM THE CENTRAL GREAT PLAINS TO THE CENTRAL
GREAT LAKES THIS AFTERNOON. THE WESTERN GREAT LAKES IS FIRMLY
ENTRENCHED WITHIN NORTHWEST FLOW ALOFT...AND SEVERAL WEAK SHORTWAVES
ARE COMBINING WITH DIURNAL INSTABILITY TO GENERATE A WIDESPREAD DIURNAL
CU FIELD. THIS CU IS MOST BUBBLY OVER NORTHERN WISCONSIN AND THE
UPPER PENINSULA WHERE THERE ARE A FEW SPECKS ON RADAR INDICATING A
FEW LIGHT SHOWERS. LOOKING UPSTREAM...SOME BREAKS IN THE CLOUD
COVER OVER NORTHERN MINNESOTA. A SHORTWAVE OVER LAKE WINNIPEG IS
PRODUCING SOME THUNDERSTORMS...BUT THAT SHOULD REMAIN NORTH OF THE
REGION TONIGHT. THEN THERE IS THE NEXT SIGNIFICANT SYSTEM WHICH IS
DIVING SOUTH OVER SASKATCHEWAN AND WILL IMPACT OUR AREA TOMORROW.
CLOUDS AND TEMPS ARE THE MAIN FORECAST CONCERNS TONIGHT...FOLLOWED
BY LOW SEVERE WEATHER CHANCES TOMORROW.
TONIGHT...ISOLATED SHOWERS WILL DIMINISH EARLY THIS EVENING WITH LOSS OF
DAYTIME HEATING. HOWEVER...WEAK MID-LEVEL WARM ADVECTION WILL
CONTINUE FOR MUCH OF THE NIGHT SO HARD TO GET A HANDLE ON SKY
CONDITIONS. SATELLITE SEEMS TO SUGGEST THAT AREAS OF MID-LEVEL
CLOUDS WILL LINGER THIS EVENING...AND THEN SOME CLEARING WILL WORK
OVERHEAD UNTIL THE NEXT SYSTEM ARRIVES THURSDAY MORNING. WILL DROP
CLOUD COVERAGE DURING THE OVERNIGHT PERIOD. MORE CLOUDS/MOISTURE
WILL KEEP TEMPS IN THE LOW TO MID 50S.
THURSDAY...A STRONG SHORTWAVE WILL MOVE ACROSS LAKE WINNIPEG AND
INTO SOUTHWEST ONTARIO. IT WILL PUSH A WEAK FRONT FROM NE MINNESOTA
TO NORTHWEST WISCONSIN OVER THE COURSE OF THE DAY. STRENGTHENING
SOUTHWEST FLOW AHEAD OF THE FRONT WILL BRING IN INCREASING AMOUNTS
OF MOISTURE...AS MODELS SHOW PWATS INCREASING TO AROUND 1.5 INCHES
FROM ABOUT AN INCH AT THE START OF THE DAY. WARM ADVECTION TO
OCCUR THROUGH THE DAY IS NOT ALL THAT STRONG...BUT WITH AMPLE
MOISTURE AND ML CAPES INCREASING TO 900-1400 J/KG IN THE
AFTERNOON...CAN ENVISION STORMS INITIATING LATE IN THE MORNING OR
EARLY AFTERNOON AND THEN BUILDING DURING THE AFTERNOON. IF ANY KIND
OF MORNING CLOUD COVER DOES NOT HOLD BACK HEATING...30-35KTS OF
0-6KM BULK SHEAR WOULD SUPPORT AN ISOLATED SEVERE THREAT. FORCING
IS ON THE WEAKER SIDE...SO DO NOT THINK ANY SORT OF WIDESPREAD
OUTBREAK IS POSSIBLE...BUT A SCATTERED COVERAGE OF STORMS ALONG WITH
AN ISOLATED SEVERE THREAT SEEMS REASONABLE. STORMS SHOULD ALSO BE
RATHER PULSIE IN NATURE. HIGHS RETURNING TO THE MID AND UPPER 70S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 312 PM CDT WED JUL 24 2013
THE SERVER CRASHED RIGHT AS WE WERE GOING TO ISSUE THE AFD AND LOST
THIS PART OF THE DISCUSSION. SINCE THE LONG TERM FORECAST HAD TO
LEAVE AT 3PM...WILL HAVE TO MAKE THIS SHORT AND SWEET.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...CONVECTION ALONG AND AHEAD OF
THE COLD FRONT WILL BE ONGOING THURSDAY NIGHT. DETAILS START TO GET
MORE MURKY BY THIS POINT...BUT FORCING IMPROVES THURSDAY NIGHT AS A
LOBE OF THE STRONG SHORTWAVE OVER ONTARIO DROPS SOUTHEAST INTO
WESTERN LAKE SUPERIOR. ELEVATED CAPE WILL BE DIMINISHING THROUGH
THE NIGHT DESPITE FORCING IMPROVING AND PWATS AROUND 1.5 INCHES.
MODELS HAVE DIFFERENT SCENARIOS PLAYING OUT THURSDAY NIGHT...WITH
SOME GUIDANCE HINTING AT AN MCS MOVING OVER CENTRAL WISCONSIN AND
THE FOX VALLEY. THE FRONT WILL FINISH CROSSING THE REGION FRIDAY
MORNING AND MUCH COLDER AIR WILL FILTER IN BEHIND THE FRONT. SOME
SHOWERS AND THUNDERSTORMS LOOK LIKELY AHEAD OF THE FRONT...AND THEN
SCATTERED SHOWERS SHOULD LINGER THROUGH DAY BEHIND THE FRONT WITH
THE SHORTWAVE OVERHEAD. WITH CLOUDY AND SHOWERY WEATHER...TEMPS
WILL STRUGGLE TO REACH THE MID 60S NORTH TO MID 70S SOUTH...AND
COULD BE LOOKING AT MORNING HIGHS. REMAINING CLOUDY FRIDAY NIGHT THOUGH
SHOWERS SHOULD BE DIMINISHING. BREEZY AND COOL WITH LOWS IN THE 40S
TO LOW 50S.
REST OF THE FORECAST....CONTINUED CLOUDY AND COOL ON SATURDAY WITH A
FEW SHOWERS POSSIBLE COMING OFF LAKE SUPERIOR INTO NORTHERN
WISCONSIN. DROPPED HIGHS SEVERAL DEGREES DUE TO CLOUD COVER AND
925MB TEMPS IN THE UPPER SINGLE DIGITS. CLOUDS AND SHOWERS POSSIBLY
TO HANG AROUND INTO SUNDAY BEFORE THE UPPER LOW FINALLY DEPARTS.
HIGH PRESSURE WILL BE OVER THE AREA ON MONDAY WHEN TEMPS MODERATE
SOME. THEN THE NEXT CHANCE OF RAIN ARRIVES TUESDAY INTO WEDNESDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 514 PM CDT WED JUL 24 2013
ISOLATED LIGHT SHOWERS WILL DISSIPATE THIS EVENING OTHERWISE VFR
CONDITIONS TO PREVAIL TONIGHT INTO THURSDAY. THE CHANCE OF SHOWERS
AND STORMS WILL BE ON THE INCREASE FROM NORTHWEST TO SOUTHEAST AS
A COLD FRONT DROPS INTO NORTHWEST WISCONSIN THURSDAY AFTERNOON
AND THEN INTO SOUTHEAST WISCONSIN THURSDAY NIGHT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......MPC
AVIATION.......TDH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 312 PM CDT WED JUL 24 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW WEAK HIGH
PRESSURE STRETCHING FROM THE CENTRAL GREAT PLAINS TO THE CENTRAL
GREAT LAKES THIS AFTERNOON. THE WESTERN GREAT LAKES IS FIRMLY
ENTRENCHED WITHIN NORTHWEST FLOW ALOFT...AND SEVERAL WEAK SHORTWAVES
ARE COMBINING WITH DIURNAL INSTABILITY TO GENERATE A WIDESPREAD DIURNAL
CU FIELD. THIS CU IS MOST BUBBLY OVER NORTHERN WISCONSIN AND THE
UPPER PENINSULA WHERE THERE ARE A FEW SPECKS ON RADAR INDICATING A
FEW LIGHT SHOWERS. LOOKING UPSTREAM...SOME BREAKS IN THE CLOUD
COVER OVER NORTHERN MINNESOTA. A SHORTWAVE OVER LAKE WINNIPEG IS
PRODUCING SOME THUNDERSTORMS...BUT THAT SHOULD REMAIN NORTH OF THE
REGION TONIGHT. THEN THERE IS THE NEXT SIGNIFICANT SYSTEM WHICH IS
DIVING SOUTH OVER SASKATCHEWAN AND WILL IMPACT OUR AREA TOMORROW.
CLOUDS AND TEMPS ARE THE MAIN FORECAST CONCERNS TONIGHT...FOLLOWED
BY LOW SEVERE WEATHER CHANCES TOMORROW.
TONIGHT...ISOLATED SHOWERS WILL DIMINISH EARLY THIS EVENING WITH LOSS OF
DAYTIME HEATING. HOWEVER...WEAK MID-LEVEL WARM ADVECTION WILL
CONTINUE FOR MUCH OF THE NIGHT SO HARD TO GET A HANDLE ON SKY
CONDITIONS. SATELLITE SEEMS TO SUGGEST THAT AREAS OF MID-LEVEL
CLOUDS WILL LINGER THIS EVENING...AND THEN SOME CLEARING WILL WORK
OVERHEAD UNTIL THE NEXT SYSTEM ARRIVES THURSDAY MORNING. WILL DROP
CLOUD COVERAGE DURING THE OVERNIGHT PERIOD. MORE CLOUDS/MOISTURE
WILL KEEP TEMPS IN THE LOW TO MID 50S.
THURSDAY...A STRONG SHORTWAVE WILL MOVE ACROSS LAKE WINNIPEG AND
INTO SOUTHWEST ONTARIO. IT WILL PUSH A WEAK FRONT FROM NE MINNESOTA
TO NORTHWEST WISCONSIN OVER THE COURSE OF THE DAY. STRENGTHENING
SOUTHWEST FLOW AHEAD OF THE FRONT WILL BRING IN INCREASING AMOUNTS
OF MOISTURE...AS MODELS SHOW PWATS INCREASING TO AROUND 1.5 INCHES
FROM ABOUT AN INCH AT THE START OF THE DAY. WARM ADVECTION TO
OCCUR THROUGH THE DAY IS NOT ALL THAT STRONG...BUT WITH AMPLE
MOISTURE AND ML CAPES INCREASING TO 900-1400 J/KG IN THE
AFTERNOON...CAN ENVISION STORMS INITIATING LATE IN THE MORNING OR
EARLY AFTERNOON AND THEN BUILDING DURING THE AFTERNOON. IF ANY KIND
OF MORNING CLOUD COVER DOES NOT HOLD BACK HEATING...30-35KTS OF
0-6KM BULK SHEAR WOULD SUPPORT AN ISOLATED SEVERE THREAT. FORCING
IS ON THE WEAKER SIDE...SO DO NOT THINK ANY SORT OF WIDESPREAD
OUTBREAK IS POSSIBLE...BUT A SCATTERED COVERAGE OF STORMS ALONG WITH
AN ISOLATED SEVERE THREAT SEEMS REASONABLE. STORMS SHOULD ALSO BE
RATHER PULSIE IN NATURE. HIGHS RETURNING TO THE MID AND UPPER 70S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 312 PM CDT WED JUL 24 2013
THE SERVER CRASHED RIGHT AS WE WERE GOING TO ISSUE THE AFD AND LOST
THIS PART OF THE DISCUSSION. SINCE THE LONG TERM FORECAST HAD TO
LEAVE AT 3PM...WILL HAVE TO MAKE THIS SHORT AND SWEET.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...CONVECTION ALONG AND AHEAD OF
THE COLD FRONT WILL BE ONGOING THURSDAY NIGHT. DETAILS START TO GET
MORE MURKY BY THIS POINT...BUT FORCING IMPROVES THURSDAY NIGHT AS A
LOBE OF THE STRONG SHORTWAVE OVER ONTARIO DROPS SOUTHEAST INTO
WESTERN LAKE SUPERIOR. ELEVATED CAPE WILL BE DIMINISHING THROUGH
THE NIGHT DESPITE FORCING IMPROVING AND PWATS AROUND 1.5 INCHES.
MODELS HAVE DIFFERENT SCENARIOS PLAYING OUT THURSDAY NIGHT...WITH
SOME GUIDANCE HINTING AT AN MCS MOVING OVER CENTRAL WISCONSIN AND
THE FOX VALLEY. THE FRONT WILL FINISH CROSSING THE REGION FRIDAY
MORNING AND MUCH COLDER AIR WILL FILTER IN BEHIND THE FRONT. SOME
SHOWERS AND THUNDERSTORMS LOOK LIKELY AHEAD OF THE FRONT...AND THEN
SCATTERED SHOWERS SHOULD LINGER THROUGH DAY BEHIND THE FRONT WITH
THE SHORTWAVE OVERHEAD. WITH CLOUDY AND SHOWERY WEATHER...TEMPS
WILL STRUGGLE TO REACH THE MID 60S NORTH TO MID 70S SOUTH...AND
COULD BE LOOKING AT MORNING HIGHS. REMAINING CLOUDY FRIDAY NIGHT THOUGH
SHOWERS SHOULD BE DIMINISHING. BREEZY AND COOL WITH LOWS IN THE 40S
TO LOW 50S.
REST OF THE FORECAST....CONTINUED CLOUDY AND COOL ON SATURDAY WITH A
FEW SHOWERS POSSIBLE COMING OFF LAKE SUPERIOR INTO NORTHERN
WISCONSIN. DROPPED HIGHS SEVERAL DEGREES DUE TO CLOUD COVER AND
925MB TEMPS IN THE UPPER SINGLE DIGITS. CLOUDS AND SHOWERS POSSIBLY
TO HANG AROUND INTO SUNDAY BEFORE THE UPPER LOW FINALLY DEPARTS.
HIGH PRESSURE WILL BE OVER THE AREA ON MONDAY WHEN TEMPS MODERATE
SOME. THEN THE NEXT CHANCE OF RAIN ARRIVES TUESDAY INTO WEDNESDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1243 PM CDT WED JUL 24 2013
AFTERNOON INSTABILITY WILL HELP GENERATE SCT SHOWERS AND
PERHAPS AN ISOLATED THUNDERSTORM THIS AFTERNOON OVER NORTH-CENTRAL
WISCONSIN. ANY SHOWERS WILL LIKELY DISSIPATE EARLY THIS
EVENING...BUT BROKEN MID-CLOUDS WILL PERSIST ACROSS MUCH OF NORTHERN
AND NORTHEAST WISCONSIN THROUGH THE EVENING IF NOT LONGER. A COLD
FRONT WILL THEN MOVE INTO NORTHWEST WISCONSIN TOMORROW...WHICH WILL
BRING BACK A CHANCE OF SHOWERS AND THUNDERSTORMS TO NORTH-CENTRAL
WISCONSIN BY LATE IN THE MORNING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......MPC
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1154 AM CDT WED JUL 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT WED JUL 24 2013
MAIN FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES
THURSDAY INTO THURSDAY NIGHT WITH THE POTENTIAL FOR SEVERE
THUNDERSTORMS. FOCUS THEN TURNS TO TEMPERATURES FRIDAY THROUGH THE
WEEKEND.
LATEST WATER VAPOR IMAGERY SHOWED NORTHWEST FLOW ALOFT OVER THE UPPER
MISSISSIPPI RIVER VALLEY EXTENDING NORTHWEST THROUGH SOUTHERN
ALBERTA. SEVERAL EMBEDDED SHORTWAVES WERE NOTED WITHIN THE
NORTHWEST FLOW. SURFACE OBSERVATIONS SHOWED HIGH PRESSURE IN
CONTROL OVER THE REGION PROVIDING QUIET CONDITIONS. SOME MID AND
HIGH LEVEL CLOUDS WERE MOVING ACROSS THE REGION EARLY THIS
MORNING. THE CLOUDS COUPLED WITH THE DRIER AIR IN PLACE OVER THE
REGION HAVE PREVENTED THE FORMATION OF FOG SO FAR. CANNOT RULE OUT
SOME PATCHY FOG EARLY THIS MORNING BUT THIS SHOULD QUICKLY
DISSIPATE AS MIXING INCREASES AFTER SUNRISE.
THE HIGH WILL SLIDE EAST OF THE AREA TODAY AS A COLD FRONT SLIDES
INTO THE EASTERN DAKOTAS AND EDGES EAST. SOME WEAK MOISTURE
TRANSPORT COMBINED WITH 0-3KM MUCAPE VALUES OF AROUND 500 J/KG MAY
BE ENOUGH TO PRODUCE ISOLATED SHOWERS AND THUNDERSTORMS OVER SOUTH
CENTRAL MINNESOTA AND POSSIBLY PORTIONS OF SOUTHEAST MINNESOTA. THE
BULK OF THIS ACTIVITY WILL LIKELY HAVE A DIFFICULT TIME MAKING IT
EAST OF THE INTERSTATE 35 CORRIDOR AS IT ENCOUNTERS MUCH DRIER AIR.
WILL HAVE TO KEEP A CLOSE EYE ON THIS...THE HRRR AND HI RES ARW ARE
BOTH PRODUCING LIGHT PRECIPITATION ALONG THE I-35 CORRIDOR AND EDGES
JUST EAST POSSIBLY IMPACTING DODGE AND MOWER COUNTIES DURING THE
AFTERNOON HOURS. OTHERWISE...PLAN ON SOME PASSING MID AND HIGH LEVEL
CLOUDS TODAY PROVIDING PARTLY SUNNY SKIES. ANOTHER DAY OF PLEASANT
TEMPERATURES WITH HIGHS IN THE LOWER TO MID 70S. THE COLD FRONT
CONTINUES TO ADVANCE SOUTHEAST TONIGHT AND BY THE LATE NIGHT HOURS
LOOKS TO BE POSITIONED FROM THE ARROWHEAD OF MINNESOTA SOUTH
THROUGH CENTRAL INTO SOUTHWEST MINNESOTA. IT THEN SLOWS AND STALLS
AS IT EDGES INTO NORTHWEST WISCONSIN BY EARLY THURSDAY MORNING.
850 MB MOISTURE TRANSPORT EDGES INTO SOUTHEAST MINNESOTA AND WEST
CENTRAL INTO NORTH CENTRAL WISCONSIN LATE TONIGHT INTO EARLY
THURSDAY MORNING. ISOLATED SHOWERS AND THUNDERSTORMS COULD MOVE INTO
THESE AREAS EARLY IN THE MORNING. OTHERWISE...PLAN ON PARTLY CLOUDY
SKIES DURING THE OVERNIGHT HOURS WITH LOW TEMPERATURES RANGING
FROM THE MID TO UPPER 50S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT WED JUL 24 2013
THE COLD FRONT SLIDES SOUTHEAST INTO THE FORECAST AREA ON THURSDAY
AS A VIGOROUS UPPER LEVEL TROUGH DIVES SOUTHEAST OUT OF SOUTHERN
MANITOBA/SASKATCHEWAN. SOUTH/SOUTHWEST FLOW INTO THE AREA AHEAD OF
THE FRONT WILL HELP TO BOOST DEWPOINTS INTO THE MID TO UPPER 60S
BY EARLY AFTERNOON. THE NAM SHOWS 0-3KM MUCAPE VALUES CLIMBING TO
AROUND 3500 J/KG. THE GFS SHOWS SLIGHTLY LOWER VALUES IN THE 2000
TO 3000 J/KG RANGE. THE ECMWF ISN/T SO AGGRESSIVE...INDICATING
VALUES IN THE 1200 TO 1600 J/KG RANGE. THE STRONGEST 0-6KM SHEAR
LAGS BEHIND THE FRONT. HOWEVER...THERE LOOKS TO BE SUFFICIENT
SHEAR TO SUPPORT A SEVERE THREAT WITH 0-6KM BULK SHEAR VALUES
HOVERING IN THE 30 TO 35 KT RANGE THURSDAY AFTERNOON INTO THURSDAY
EVENING. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT
THURSDAY AFTERNOON AND HEAD EAST SOUTHEAST ACROSS THE FORECAST
AREA. SOME OF THESE STORMS MAY BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS. WILL ALSO HAVE TO KEEP AN EYE ON THE POTENTIAL FOR
AN ISOLATED TORNADO OR TWO WITH ANY STORMS THAT GO UP ALONG THE
BOUNDARY. SHOWERS AND THUNDERSTORMS ARE LIKELY ACROSS THE AREA
THURSDAY NIGHT AS THE COLD FRONT MOVES THROUGH. THE SEVERE WEATHER
THREAT WILL LINGER THROUGH THE EVENING HOURS BUT SHOULD THEN WANE
DURING THE OVERNIGHT HOURS AS CONVECTION BECOMES WIDESPREAD.
THE FRONT FINALLY EXITS THE AREA BY FRIDAY AFTERNOON AS THE
TROUGH DIVES INTO THE UPPER MISSISSIPPI RIVER VALLEY. AN
UNSEASONABLY COOL AIRMASS MOVES INTO THE REGION IN THE WAKE OF THE
FRONT. 850 MB TEMPERATURE STANDARDIZED ANOMALIES FALL INTO THE
-2.0 TO -3.0 RANGE...INDICATIVE OF NEAR RECORD LOW MAX AND MIN
TEMPERATURES. THE COLDEST AIR ALOFT MOVES OVER THE REGION DURING
THE DAY ON SATURDAY...WHEN HIGHS WILL STRUGGLE TO GET OUT OF THE
60S. THE LOWEST HIGH TEMPERATURE AT LA CROSSE FOR JULY 27 IS 69
DEGREES...SET BACK IN 1981. THE LOWEST HIGH TEMPERATURE FOR
ROCHESTER IS 64 AND WAS ALSO SET BACK IN 1981. LA CROSSE LOOKS TO
BE VERY CLOSE TO REACHING THIS RECORD. CURRENT THINKING IS THAT LA
CROSSE WILL SEE A HIGH OF 71...BUT IF THE GEM AND ECMWF
VERIFY...THIS FORECAST HIGH TEMPERATURE COULD BE 3 TO 4 DEGREES
HIGH. THE UPPER TROUGH WILL REMAIN OVER THE WESTERN GREAT LAKES
THROUGH THE REMAINDER OF THE WEEKEND WITH COOL SURFACE HIGH
PRESSURE IN CONTROL. PLAN ON HIGHS ON SATURDAY RANGING FROM THE
MID 60S OVER FAR NORTHERN WISCONSIN TO AROUND 71 ACROSS FAR
SOUTHWEST WISCONSIN. TEMPS WILL WARM A BIT ON SUNDAY AS THE TROUGH
STARTS TO SHIFT EAST AND SURFACE WINDS TURN WESTERLY. HIGH
TEMPERATURES ON SUNDAY ARE EXPECTED TO CLIMB INTO THE LOWER 70S
UNDER MOSTLY SUNNY SKIES. THE UPPER TROUGH FINALLY PUSHES EAST OF
THE REGION EARLY NEXT WEEK WITH FLOW ALOFT TURNING QUASI ZONAL.
FORECAST MODELS SHOWING SOME DIFFERENCES IN THE HANDLING OF THE
UPPER LEVEL PATTERN OVER THE CONUS. THE GFS TRIES TO BUILD A RIDGE
OVER THE THE HIGH PLAINS WHILE THE ECMWF LEANS TOWARD AN ACTIVE
QUASI ZONAL FLOW ALOFT WITH EMBEDDED SHORTWAVES BRINGING SHOWERS
AND STORMS TO THE FORECAST AREA. HAVE LEANED TOWARD A MODEL
CONSENSUS BLEND FOR THE FIRST PART OF THE WORK WEEK...WITH HIGHS
WARMING TO MORE SEASONABLE VALUES WITH HIGHS IN THE UPPER 70S TO
AROUND 80 AND CHANCES FOR SHOWERS AND THUNDERSTORMS MONDAY INTO
TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1154 AM CDT WED JUL 24 2013
VFR CONDITIONS ARE EXPECTED THROUGH TOMORROW MORNING AS A COLD
FRONT STALLS OUT JUST TO THE WEST OF THE REGION. CLOUD COVER WILL
VARY THROUGH THIS AFTERNOON WITH SCT-BKN CEILINGS BETWEEN 4KFT TO
8KFT. AS A RIDGE OF HIGH PRESSURE SHIFTS TO THE EAST...WINDS WILL
COME AROUND TO THE SOUTH THIS EVENING AND PICK UP TO AROUND
10-12KT BY TOMORROW MORNING. RAIN SHOWERS AND THUNDERSTORMS ARE
POSSIBLE TOMORROW AFTERNOON...JUST AFTER THIS TAF PERIOD ENDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
555 AM CDT WED JUL 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT WED JUL 24 2013
MAIN FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES
THURSDAY INTO THURSDAY NIGHT WITH THE POTENTIAL FOR SEVERE
THUNDERSTORMS. FOCUS THEN TURNS TO TEMPERATURES FRIDAY THROUGH THE
WEEKEND.
LATEST WATER VAPOR IMAGERY SHOWED NORTHWEST FLOW ALOFT OVER THE UPPER
MISSISSIPPI RIVER VALLEY EXTENDING NORTHWEST THROUGH SOUTHERN
ALBERTA. SEVERAL EMBEDDED SHORTWAVES WERE NOTED WITHIN THE
NORTHWEST FLOW. SURFACE OBSERVATIONS SHOWED HIGH PRESSURE IN
CONTROL OVER THE REGION PROVIDING QUIET CONDITIONS. SOME MID AND
HIGH LEVEL CLOUDS WERE MOVING ACROSS THE REGION EARLY THIS
MORNING. THE CLOUDS COUPLED WITH THE DRIER AIR IN PLACE OVER THE
REGION HAVE PREVENTED THE FORMATION OF FOG SO FAR. CANNOT RULE OUT
SOME PATCHY FOG EARLY THIS MORNING BUT THIS SHOULD QUICKLY
DISSIPATE AS MIXING INCREASES AFTER SUNRISE.
THE HIGH WILL SLIDE EAST OF THE AREA TODAY AS A COLD FRONT SLIDES
INTO THE EASTERN DAKOTAS AND EDGES EAST. SOME WEAK MOISTURE
TRANSPORT COMBINED WITH 0-3KM MUCAPE VALUES OF AROUND 500 J/KG MAY
BE ENOUGH TO PRODUCE ISOLATED SHOWERS AND THUNDERSTORMS OVER SOUTH
CENTRAL MINNESOTA AND POSSIBLY PORTIONS OF SOUTHEAST MINNESOTA. THE
BULK OF THIS ACTIVITY WILL LIKELY HAVE A DIFFICULT TIME MAKING IT
EAST OF THE INTERSTATE 35 CORRIDOR AS IT ENCOUNTERS MUCH DRIER AIR.
WILL HAVE TO KEEP A CLOSE EYE ON THIS...THE HRRR AND HI RES ARW ARE
BOTH PRODUCING LIGHT PRECIPITATION ALONG THE I-35 CORRIDOR AND EDGES
JUST EAST POSSIBLY IMPACTING DODGE AND MOWER COUNTIES DURING THE
AFTERNOON HOURS. OTHERWISE...PLAN ON SOME PASSING MID AND HIGH LEVEL
CLOUDS TODAY PROVIDING PARTLY SUNNY SKIES. ANOTHER DAY OF PLEASANT
TEMPERATURES WITH HIGHS IN THE LOWER TO MID 70S. THE COLD FRONT
CONTINUES TO ADVANCE SOUTHEAST TONIGHT AND BY THE LATE NIGHT HOURS
LOOKS TO BE POSITIONED FROM THE ARROWHEAD OF MINNESOTA SOUTH
THROUGH CENTRAL INTO SOUTHWEST MINNESOTA. IT THEN SLOWS AND STALLS
AS IT EDGES INTO NORTHWEST WISCONSIN BY EARLY THURSDAY MORNING.
850 MB MOISTURE TRANSPORT EDGES INTO SOUTHEAST MINNESOTA AND WEST
CENTRAL INTO NORTH CENTRAL WISCONSIN LATE TONIGHT INTO EARLY
THURSDAY MORNING. ISOLATED SHOWERS AND THUNDERSTORMS COULD MOVE INTO
THESE AREAS EARLY IN THE MORNING. OTHERWISE...PLAN ON PARTLY CLOUDY
SKIES DURING THE OVERNIGHT HOURS WITH LOW TEMPERATURES RANGING
FROM THE MID TO UPPER 50S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT WED JUL 24 2013
THE COLD FRONT SLIDES SOUTHEAST INTO THE FORECAST AREA ON THURSDAY
AS A VIGOROUS UPPER LEVEL TROUGH DIVES SOUTHEAST OUT OF SOUTHERN
MANITOBA/SASKATCHEWAN. SOUTH/SOUTHWEST FLOW INTO THE AREA AHEAD OF
THE FRONT WILL HELP TO BOOST DEWPOINTS INTO THE MID TO UPPER 60S
BY EARLY AFTERNOON. THE NAM SHOWS 0-3KM MUCAPE VALUES CLIMBING TO
AROUND 3500 J/KG. THE GFS SHOWS SLIGHTLY LOWER VALUES IN THE 2000
TO 3000 J/KG RANGE. THE ECMWF ISN/T SO AGGRESSIVE...INDICATING
VALUES IN THE 1200 TO 1600 J/KG RANGE. THE STRONGEST 0-6KM SHEAR
LAGS BEHIND THE FRONT. HOWEVER...THERE LOOKS TO BE SUFFICIENT
SHEAR TO SUPPORT A SEVERE THREAT WITH 0-6KM BULK SHEAR VALUES
HOVERING IN THE 30 TO 35 KT RANGE THURSDAY AFTERNOON INTO THURSDAY
EVENING. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT
THURSDAY AFTERNOON AND HEAD EAST SOUTHEAST ACROSS THE FORECAST
AREA. SOME OF THESE STORMS MAY BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS. WILL ALSO HAVE TO KEEP AN EYE ON THE POTENTIAL FOR
AN ISOLATED TORNADO OR TWO WITH ANY STORMS THAT GO UP ALONG THE
BOUNDARY. SHOWERS AND THUNDERSTORMS ARE LIKELY ACROSS THE AREA
THURSDAY NIGHT AS THE COLD FRONT MOVES THROUGH. THE SEVERE WEATHER
THREAT WILL LINGER THROUGH THE EVENING HOURS BUT SHOULD THEN WANE
DURING THE OVERNIGHT HOURS AS CONVECTION BECOMES WIDESPREAD.
THE FRONT FINALLY EXITS THE AREA BY FRIDAY AFTERNOON AS THE
TROUGH DIVES INTO THE UPPER MISSISSIPPI RIVER VALLEY. AN
UNSEASONABLY COOL AIRMASS MOVES INTO THE REGION IN THE WAKE OF THE
FRONT. 850 MB TEMPERATURE STANDARDIZED ANOMALIES FALL INTO THE
-2.0 TO -3.0 RANGE...INDICATIVE OF NEAR RECORD LOW MAX AND MIN
TEMPERATURES. THE COLDEST AIR ALOFT MOVES OVER THE REGION DURING
THE DAY ON SATURDAY...WHEN HIGHS WILL STRUGGLE TO GET OUT OF THE
60S. THE LOWEST HIGH TEMPERATURE AT LA CROSSE FOR JULY 27 IS 69
DEGREES...SET BACK IN 1981. THE LOWEST HIGH TEMPERATURE FOR
ROCHESTER IS 64 AND WAS ALSO SET BACK IN 1981. LA CROSSE LOOKS TO
BE VERY CLOSE TO REACHING THIS RECORD. CURRENT THINKING IS THAT LA
CROSSE WILL SEE A HIGH OF 71...BUT IF THE GEM AND ECMWF
VERIFY...THIS FORECAST HIGH TEMPERATURE COULD BE 3 TO 4 DEGREES
HIGH. THE UPPER TROUGH WILL REMAIN OVER THE WESTERN GREAT LAKES
THROUGH THE REMAINDER OF THE WEEKEND WITH COOL SURFACE HIGH
PRESSURE IN CONTROL. PLAN ON HIGHS ON SATURDAY RANGING FROM THE
MID 60S OVER FAR NORTHERN WISCONSIN TO AROUND 71 ACROSS FAR
SOUTHWEST WISCONSIN. TEMPS WILL WARM A BIT ON SUNDAY AS THE TROUGH
STARTS TO SHIFT EAST AND SURFACE WINDS TURN WESTERLY. HIGH
TEMPERATURES ON SUNDAY ARE EXPECTED TO CLIMB INTO THE LOWER 70S
UNDER MOSTLY SUNNY SKIES. THE UPPER TROUGH FINALLY PUSHES EAST OF
THE REGION EARLY NEXT WEEK WITH FLOW ALOFT TURNING QUASI ZONAL.
FORECAST MODELS SHOWING SOME DIFFERENCES IN THE HANDLING OF THE
UPPER LEVEL PATTERN OVER THE CONUS. THE GFS TRIES TO BUILD A RIDGE
OVER THE THE HIGH PLAINS WHILE THE ECMWF LEANS TOWARD AN ACTIVE
QUASI ZONAL FLOW ALOFT WITH EMBEDDED SHORTWAVES BRINGING SHOWERS
AND STORMS TO THE FORECAST AREA. HAVE LEANED TOWARD A MODEL
CONSENSUS BLEND FOR THE FIRST PART OF THE WORK WEEK...WITH HIGHS
WARMING TO MORE SEASONABLE VALUES WITH HIGHS IN THE UPPER 70S TO
AROUND 80 AND CHANCES FOR SHOWERS AND THUNDERSTORMS MONDAY INTO
TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 555 AM CDT WED JUL 24 2013
DRY AIR IN THE LOWER LEVELS OF THE ATMOSPHERE...ASSOCIATED WITH
HIGH PRESSURE OVER THE TAF SITES...WILL HELP TO KEEP CONDITIONS
VFR THROUGH TONIGHT. PERIODS OF CLOUDS ARE ANTICIPATED TO CROSS
THE TAF SITES...AND SOME OF THESE COULD TRY TO PRODUCE A FEW LIGHT
SHOWERS NEAR RST THIS AFTERNOON AND VERY LATE TONIGHT...BUT AGAIN
CONDITIONS WILL REMAIN VFR. DID MAINTAIN A VCFG AT LSE UNTIL 13Z
THIS MORNING BECAUSE OF FOG IN NEARBY RIVER VALLEYS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
345 AM CDT WED JUL 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT WED JUL 24 2013
MAIN FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES
THURSDAY INTO THURSDAY NIGHT WITH THE POTENTIAL FOR SEVERE
THUNDERSTORMS. FOCUS THEN TURNS TO TEMPERATURES FRIDAY THROUGH THE
WEEKEND.
LATEST WATER VAPOR IMAGERY SHOWED NORTHWEST FLOW ALOFT OVER THE UPPER
MISSISSIPPI RIVER VALLEY EXTENDING NORTHWEST THROUGH SOUTHERN
ALBERTA. SEVERAL EMBEDDED SHORTWAVES WERE NOTED WITHIN THE
NORTHWEST FLOW. SURFACE OBSERVATIONS SHOWED HIGH PRESSURE IN
CONTROL OVER THE REGION PROVIDING QUIET CONDITIONS. SOME MID AND
HIGH LEVEL CLOUDS WERE MOVING ACROSS THE REGION EARLY THIS
MORNING. THE CLOUDS COUPLED WITH THE DRIER AIR IN PLACE OVER THE
REGION HAVE PREVENTED THE FORMATION OF FOG SO FAR. CANNOT RULE OUT
SOME PATCHY FOG EARLY THIS MORNING BUT THIS SHOULD QUICKLY
DISSIPATE AS MIXING INCREASES AFTER SUNRISE.
THE HIGH WILL SLIDE EAST OF THE AREA TODAY AS A COLD FRONT SLIDES
INTO THE EASTERN DAKOTAS AND EDGES EAST. SOME WEAK MOISTURE
TRANSPORT COMBINED WITH 0-3KM MUCAPE VALUES OF AROUND 500 J/KG MAY
BE ENOUGH TO PRODUCE ISOLATED SHOWERS AND THUNDERSTORMS OVER SOUTH
CENTRAL MINNESOTA AND POSSIBLY PORTIONS OF SOUTHEAST MINNESOTA. THE
BULK OF THIS ACTIVITY WILL LIKELY HAVE A DIFFICULT TIME MAKING IT
EAST OF THE INTERSTATE 35 CORRIDOR AS IT ENCOUNTERS MUCH DRIER AIR.
WILL HAVE TO KEEP A CLOSE EYE ON THIS...THE HRRR AND HI RES ARW ARE
BOTH PRODUCING LIGHT PRECIPITATION ALONG THE I-35 CORRIDOR AND EDGES
JUST EAST POSSIBLY IMPACTING DODGE AND MOWER COUNTIES DURING THE
AFTERNOON HOURS. OTHERWISE...PLAN ON SOME PASSING MID AND HIGH LEVEL
CLOUDS TODAY PROVIDING PARTLY SUNNY SKIES. ANOTHER DAY OF PLEASANT
TEMPERATURES WITH HIGHS IN THE LOWER TO MID 70S. THE COLD FRONT
CONTINUES TO ADVANCE SOUTHEAST TONIGHT AND BY THE LATE NIGHT HOURS
LOOKS TO BE POSITIONED FROM THE ARROWHEAD OF MINNESOTA SOUTH
THROUGH CENTRAL INTO SOUTHWEST MINNESOTA. IT THEN SLOWS AND STALLS
AS IT EDGES INTO NORTHWEST WISCONSIN BY EARLY THURSDAY MORNING.
850 MB MOISTURE TRANSPORT EDGES INTO SOUTHEAST MINNESOTA AND WEST
CENTRAL INTO NORTH CENTRAL WISCONSIN LATE TONIGHT INTO EARLY
THURSDAY MORNING. ISOLATED SHOWERS AND THUNDERSTORMS COULD MOVE INTO
THESE AREAS EARLY IN THE MORNING. OTHERWISE...PLAN ON PARTLY CLOUDY
SKIES DURING THE OVERNIGHT HOURS WITH LOW TEMPERATURES RANGING
FROM THE MID TO UPPER 50S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT WED JUL 24 2013
THE COLD FRONT SLIDES SOUTHEAST INTO THE FORECAST AREA ON THURSDAY
AS A VIGOROUS UPPER LEVEL TROUGH DIVES SOUTHEAST OUT OF SOUTHERN
MANITOBA/SASKATCHEWAN. SOUTH/SOUTHWEST FLOW INTO THE AREA AHEAD OF
THE FRONT WILL HELP TO BOOST DEWPOINTS INTO THE MID TO UPPER 60S
BY EARLY AFTERNOON. THE NAM SHOWS 0-3KM MUCAPE VALUES CLIMBING TO
AROUND 3500 J/KG. THE GFS SHOWS SLIGHTLY LOWER VALUES IN THE 2000
TO 3000 J/KG RANGE. THE ECMWF ISN/T SO AGGRESSIVE...INDICATING
VALUES IN THE 1200 TO 1600 J/KG RANGE. THE STRONGEST 0-6KM SHEAR
LAGS BEHIND THE FRONT. HOWEVER...THERE LOOKS TO BE SUFFICIENT
SHEAR TO SUPPORT A SEVERE THREAT WITH 0-6KM BULK SHEAR VALUES
HOVERING IN THE 30 TO 35 KT RANGE THURSDAY AFTERNOON INTO THURSDAY
EVENING. THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT
THURSDAY AFTERNOON AND HEAD EAST SOUTHEAST ACROSS THE FORECAST
AREA. SOME OF THESE STORMS MAY BECOME SEVERE WITH LARGE HAIL AND
DAMAGING WINDS. WILL ALSO HAVE TO KEEP AN EYE ON THE POTENTIAL FOR
AN ISOLATED TORNADO OR TWO WITH ANY STORMS THAT GO UP ALONG THE
BOUNDARY. SHOWERS AND THUNDERSTORMS ARE LIKELY ACROSS THE AREA
THURSDAY NIGHT AS THE COLD FRONT MOVES THROUGH. THE SEVERE WEATHER
THREAT WILL LINGER THROUGH THE EVENING HOURS BUT SHOULD THEN WANE
DURING THE OVERNIGHT HOURS AS CONVECTION BECOMES WIDESPREAD.
THE FRONT FINALLY EXITS THE AREA BY FRIDAY AFTERNOON AS THE
TROUGH DIVES INTO THE UPPER MISSISSIPPI RIVER VALLEY. AN
UNSEASONABLY COOL AIRMASS MOVES INTO THE REGION IN THE WAKE OF THE
FRONT. 850 MB TEMPERATURE STANDARDIZED ANOMALIES FALL INTO THE
-2.0 TO -3.0 RANGE...INDICATIVE OF NEAR RECORD LOW MAX AND MIN
TEMPERATURES. THE COLDEST AIR ALOFT MOVES OVER THE REGION DURING
THE DAY ON SATURDAY...WHEN HIGHS WILL STRUGGLE TO GET OUT OF THE
60S. THE LOWEST HIGH TEMPERATURE AT LA CROSSE FOR JULY 27 IS 69
DEGREES...SET BACK IN 1981. THE LOWEST HIGH TEMPERATURE FOR
ROCHESTER IS 64 AND WAS ALSO SET BACK IN 1981. LA CROSSE LOOKS TO
BE VERY CLOSE TO REACHING THIS RECORD. CURRENT THINKING IS THAT LA
CROSSE WILL SEE A HIGH OF 71...BUT IF THE GEM AND ECMWF
VERIFY...THIS FORECAST HIGH TEMPERATURE COULD BE 3 TO 4 DEGREES
HIGH. THE UPPER TROUGH WILL REMAIN OVER THE WESTERN GREAT LAKES
THROUGH THE REMAINDER OF THE WEEKEND WITH COOL SURFACE HIGH
PRESSURE IN CONTROL. PLAN ON HIGHS ON SATURDAY RANGING FROM THE
MID 60S OVER FAR NORTHERN WISCONSIN TO AROUND 71 ACROSS FAR
SOUTHWEST WISCONSIN. TEMPS WILL WARM A BIT ON SUNDAY AS THE TROUGH
STARTS TO SHIFT EAST AND SURFACE WINDS TURN WESTERLY. HIGH
TEMPERATURES ON SUNDAY ARE EXPECTED TO CLIMB INTO THE LOWER 70S
UNDER MOSTLY SUNNY SKIES. THE UPPER TROUGH FINALLY PUSHES EAST OF
THE REGION EARLY NEXT WEEK WITH FLOW ALOFT TURNING QUASI ZONAL.
FORECAST MODELS SHOWING SOME DIFFERENCES IN THE HANDLING OF THE
UPPER LEVEL PATTERN OVER THE CONUS. THE GFS TRIES TO BUILD A RIDGE
OVER THE THE HIGH PLAINS WHILE THE ECMWF LEANS TOWARD AN ACTIVE
QUASI ZONAL FLOW ALOFT WITH EMBEDDED SHORTWAVES BRINGING SHOWERS
AND STORMS TO THE FORECAST AREA. HAVE LEANED TOWARD A MODEL
CONSENSUS BLEND FOR THE FIRST PART OF THE WORK WEEK...WITH HIGHS
WARMING TO MORE SEASONABLE VALUES WITH HIGHS IN THE UPPER 70S TO
AROUND 80 AND CHANCES FOR SHOWERS AND THUNDERSTORMS MONDAY INTO
TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1152 PM CDT TUE JUL 23 2013
BAND OF MID LEVEL CLOUDS CONTINUES TO ADVANCE SOUTHEAST TOWARD THE
AREA THIS EVENING OUT OF THE DAKOTAS AND NORTHWEST MINNESOTA AHEAD
OF A SHORT WAVE TROUGH. THE CLOUDS APPEAR TO BE LOOSING SOME
ORGANIZATION RAISING THE CONCERN WHETHER THEY WILL COME THROUGH
BROKEN OR SCATTERED. FOR NOW...WILL CONTINUE TO SHOW A BROKEN DECK
COMING THROUGH LATE TONIGHT INTO WEDNESDAY MORNING. IF THIS
HAPPENS...IT SHOULD PRECLUDE ANY FOG FROM FORMING AT KLSE AS WELL.
TEMP/DEW POINT SPREAD WAS AT 9 DEGREES AT 03Z WHICH IS A LITTLE
OUTSIDE THE OPTIMAL RANGE WANTED FOR FOG FORMATION. WILL MAINTAIN
THE VCFG IN CASE THE CLOUDS COME THROUGH SCATTERED INSTEAD OF
BROKEN...BUT CONFIDENCE IS PRETTY LOW ON FOG FORMATION. AS THE
HIGH PULLS OFF TO THE EAST WEDNESDAY AFTERNOON...COULD BE ENOUGH
MOISTURE RETURN TO GENERATE SOME AFTERNOON CUMULUS AT KRST BUT NOT
EXPECTING THERE TO BE ANY SHOWER DEVELOPMENT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1112 PM MDT TUE JUL 23 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 PM MDT TUE JUL 23 2013
AN INFLUX OF MONSOONAL MOISTURE WILL INDICATE A TURN TO A MUCH MORE
CLIMATOLOGICALLY NORMAL PERIOD OF UNSETTLED WEATHER BEGINNING
WEDNESDAY AND CONTINUING THROUGH MUCH OF THE LONGER TERM. BEFORE
THEN...AFTERNOON SATELLITE PIX SHOW SHALLOW CONVECTION BEGINNING TO
DEVELOP OVER THE NORTHERN LARAMIE RANGE. A RESULT OF LLVL
CONVERGENCE DUE TO A STATIONARY BOUNDARY DRAPED UP ALONG THE FRONT
RANGE. DEW POINTS WEST OF THIS BOUNDARY WERE BELOW 30F...WITH
RAWLINS REPORTING 11F. MORE AMPLE LLVL MOISTURE EAST OF THIS
BOUNDARY AS INDICATED BY 50 DEGREE DEW POINTS. IN FACT...THIS
BOUNDARY PUSHED EAST OF KCYS EARLY THIS MORNING DROPPING DEWPOINTS
BRIEFLY BACK INTO THE 20S. MOST OF THE CWA WILL REMAIN DRY THIS
EVENING...THESE EXCEPTION BEING THE FAR EASTERN ROW OF COUNTIES FROM
CHADRON TO BRIDGEPORT. AS HAS BEEN THE CASE THE PAST SEVERAL
DAYS...12Z MODEL OUTPUT CONTINUES TO SUGGEST CAP WILL HOLD AND THE
AREA WILL REMAIN DRY. EVEN THE LATEST HRRR DEVELOPS CONVECTION JUST
EAST OF THE CWFA. PERSISTENCE SAYS OTHERWISE HOWEVER...SO WILL KEEP
SLIGHT CHANCES GOING FROM CHADRON AND BRIDGEPORT. IF THE CAP DOES
MANAGE TO BREAK...SBCAPES OF 1000 TO 1500 J/KG WOULD BE REALIZED
WHICH COULD RESULT IN SOME SEVERE DEVELOPMENT. ANY THUNDERSTORMS
WILL WIND DOWN BY LATE EVENING.
ATTENTION THEN SHIFTS TO UPSTREAM MOISTURE AND SHORTWAVE EVIDENT ON
WV IMAGERY FROM NRN CA/SRN OR EAST INTO UTAH. THIS SUB-TROPICAL
MONSOON MOISTURE PLUME AND SHORTWAVE WILL SLOWLY MEANDER NORTH INTO
THE REGION ON WEDNESDAY. 12Z MODELS HAVE DELAYED ITS ARRIVAL BY A
FEW HOURS. ALTHOUGH THERE IS SOME POTENTIAL FOR DRY LIGHTNING EARLY
WEDNESDAY...AM NOT CONFIDENT ON ITS COVERAGE. SO FOR NOW...HAVE
MAINTAINED THE INHERITED COVERAGE...BUT HAVE CONFINED IT TO THE
SNOWY/SIERRA MADRE RANGES WEDNESDAY MORNING. BY MIDDAY
WEDNESDAY...CONVECTION WILL BE DEVELOPING OVER THE SE WYOMING
MOUNTAINS AND ADJACENT FOOTHILLS/VALLEY LOCATIONS. PROGD SBCAPES
WILL NOT BE PARTICULARLY HIGH (500-800 J/KG). HOWEVER PWATS RISING
ABOVE AN INCH ALONG WITH STORM MOTIONS OF 10 KNOTS OR LESS WILL
RESULT IN EFFICIENT RAIN PRODUCERS. CAN NOT RULE OUT THE POTENTIAL
FOR SMALL HAIL TOO...THOUGH THERMODYNAMIC PARAMETERS ARE NOT
FAVORABLE. SHORTWAVE WILL MEANDER ATOP THE CWA WEDNESDAY NIGHT WHICH
SHOULD AID IN THE CONTINUATION OF NOCTURNAL CONVECTION.
MID/UPPER-LEVEL FLOW WILL TURN NORTHWEST FOR THURSDAY BEHIND
DEPARTING SHORTWAVE. AT THE SFC...A WEAK COOL FRONT ALONG WITH
FAVORABLE UPSLOPE BEHIND FROPA WILL SET THE STAGE FOR ANOTHER ROUND
OF AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS. AGAIN AMPLE MOISTURE
WILL ACT TO LIMIT SEVERE POTENTIAL...ONLY YIELDING SBCAPES OF
500-800 J/KG. STORM MOTIONS WILL AGAIN BE LESS THAN 10 KNOTS.
THE THICKER CLOUD CANOPY ALONG WITH WEAK COLD FROPA ON THURSDAY WILL
CAUSE TEMPERATURES TO COOL FROM THE UPPER 80S ON WEDNESDAY INTO THE
LOWER 80S ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 PM MDT TUE JUL 23 2013
MONSOONAL MOISTURE WILL CONTINUE TO STREAM INTO THE REGION ON
FRIDAY THROUGH THE WEEKEND. SHORTWAVE MOVES SOUTHWARD ACROSS THE
NORTHERN HIGH PLAINS ON THURSDAY NIGHT WITH RISING SFC PRESSURES
BEHIND IT OVER THE PLAINS. THIS RESULTS IN GOOD SOUTHEAST UPSLOPE
BY FRIDAY WITH PW VALUES OF 1.00-1.25 INCHES OVER MOST AREAS ALONG
AND EAST OF THE LARAMIE RANGE. WIDESPREAD QPF IS DEPICTED ON BOTH
THE GFS AND ECMWF BY FRIDAY AFTN/EVENING. WITH DEEP LAYER SHEAR OF
50 KTS AND CAPE VALUES OF 1250-1500 J/KG...A FEW STRONG TO SEVERE
STORMS COULD BE POSSIBLE OVER THE PLAINS. THE STEERING FLOW IS A
LITTLE TOO FAST FOR MAJOR FLASH FLOODING CONCERNS ON FRIDAY. UPPER
LEVEL RIDGE AXIS IS POSITIONED OVER WESTERN WY BY SATURDAY
AFTN...WITH NORTHWESTERLY MIDLEVEL FLOW PERSISTING IN THE CWA.
CONVECTIVE PARAMETERS APPEAR VERY SIMILAR TO FRIDAY...SO GENERALLY
CARRIED THE SAME POPS. RIDGE AXIS IS ALMOST DIRECTLY OVER THE CWA
BY SUNDAY WITH STEERING FLOW BECOMING MORE WESTERLY AND SOMEWHAT
SLOWER THAN THE PREVIOUS DAYS. SHORTWAVE ROTATES THROUGH THE AREA
DURING PEAK HEATING AND WITH PW VALUES REMAINING ABOVE
NORMAL...EXPECT ANOTHER DAY OF GOOD STORM COVERAGE. DRIER
700-500MB FLOW CREEPS INTO THE REGION BY MONDAY WHICH COULD RESULT
IN MORE ISOLATED TSTM CHANCES. TEMPS THROUGHOUT THE PERIOD WILL BE
SLIGHTLY BELOW AVERAGE WITH THE MOIST AIRMASS AND RATHER CLOUDY
CONDITIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1112 PM MDT TUE JUL 23 2013
VFR EXPECTED ACROSS ALL AERODROMES FOR THE REST OF THE NIGHT THROUGH
EARLY WEDS AFTERNOON. INCREASING MONSOONAL MOISTURE SHOULD ALLOW
FOR SOMEWHAT MORE WIDESPREAD SHOWERS AND STORMS WEDS AFTERNOON AND
EVENING WITH ASSOCIATED PERIODS OF LOWERED VSBYS AND GUSTY WINDS IN
THE STRONGER STORMS.
&&
.FIRE WEATHER...
ISSUED AT 330 PM MDT TUE JUL 23 2013
MONSOONAL MOISTURE WILL RETURN TO THE DISTRICT IN EARNEST DURING THE
DAY ON WEDNESDAY. AS THIS OCCURS...WE MAY BE ABLE TO SEE SOME
HIGH-BASED SHOWER/THUNDERSTORM DEVELOPMENT MAINLY OVER THE SNOWY AND
SIERRA MADRE RANGES. AM NOT CONFIDENT OF WHETHER OR NOT THIS WILL
OCCUR...BUT IF IT DOES THE BEST TIME WILL BE BETWEEN 6AM AND NOON
WEDNESDAY. AFTER THAT...BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL RETURN TO THE DISTRICT BEGINNING WEDNESDAY AFTERNOON AND
CONTINUING INTO THE UPCOMING WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...HAHN
LONG TERM...FINCH
AVIATION...LIEBL
FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
355 AM EDT FRI JUL 26 2013
.DISCUSSION...
TODAY-TONIGHT...
CONVECTIVE PRECIP BAND PUSHING INTO THE VCNTY OF LAKE OKEECHOBEE IS
ASSOCD WITH A PREFRONTAL TROF OVER THE CENTRAL PENINSULA. THE ACTUAL
FRONT ITSELF IS HUNG UP OVER THE DEEP SOUTH AND UNDERGOING
FRONTALYSIS ACCORDING TO NCEP SFC ANALYSIS. WIND PROFILE DATA SHOWS
H100-H70 WINDS HAVE SHIFTED TO THE N/NE AT KJAX...NW AT KTBW...AND
TO THE W/NW AT KMLB...INDICATING THE TROF AXIS IS BISECTING THE
PENINSULA AS OF 07Z. RAP ANALYSIS CONFIRMS THIS WITH A MID LVL VORT
AXIS JUST S OF THE I-4 CORRIDOR.
A CLOSED H100-H70 LOW LIFTING UP THE ERN SEABOARD WILL COMBINE WITH
A WEAK ANTICYCLONE OVER THE LWR MS VALLEY TO PUSH THE TROF AXIS THRU
CENTRAL FL THRU THE DAY. THIS WILL RESULT IN A N/NERLY H100-H70 WIND
FIELD OVER MOST OF THE CWA...CONFIRMED BY THE KJAX VAD WIND DATA.
THIS FLOW REGIME IS ONE OF THE MOST INACTIVE WRT CENTRAL FL TSRA
ACTIVITY AS IT TAPS THE COOLER AIR OVER THE COOLER SHELF WATERS
WHILE PULLING DRY CONTINENTAL AIR INTO FL.
RAP ANALYSIS SHOWS THIS WILL BE THE CASE AS UPSTREAM MOISTURE IS
LACKING WITH H100-H85 MEAN RH VALUES DROPPING BLO 60PCT WHILE
H50-H50 LAPSE RATES OVER THE NORTH HALF OF THE PENINSULA ARE BLO
5.0C/KM WITH H50 TEMPS BTWN -3C AND -4C. WEAK MID LVL VORTICITY AND
UPR LVL DIVERGENCE BEHIND THE PREFRONTAL TROF AXIS WILL ONLY FURTHER
"DAMPEN" THE PROSPECTS FOR SHRA/TSRA DVLPMNT.
SFC DEWPOINTS REMAIN IN THE L/M70S...AND WITH CLR SKIES OVER N FL
WORKING THEIR WAY SOUTH...SHOULD SEE NEAR FULL SUN THRU THE PEAK
HEATING HRS ALONG AND N OF THE I-4 CORRIDOR. WEAK PGRAD WILL ALLOW
BOTH SEA BREEZES TO FORM BY MIDDAY WITH THE COLLISION ZONE W OF THE
FL TURNPIKE BY LATE AFTN.
WILL REMOVE THUNDER E OF KLEE-KMCO-KMLB AND GO WITH ISOLD SHRAS AS
THE INSTABILITY LVLS ARE JUST TOO LOW TO SUPPORT DEEP CONVECTION.
SCT SHRAS/ISOLD TSRAS TO THE SW OF KLEE-KMCO-KMLB AS THE DYNAMIC
LIFT SUPPORT WILL BE A LITTLE STRONGER AND THE MOISTURE A LITTLE
HIGHER NEAR THE VCNTY OF THE TROF AXIS. STORM MOTION WILL BE S/SE AT
10-15 MPH...UNUSUAL FOR MID SUMMER. LINGERING MOISTURE AROUND LAKE
OKEECHOBEE MAY ALLOW CONVECTION TO CONTINUE THRU MID EVEN...BUT
PRECIP SHOULD BE DONE WELL BEFORE MIDNIGHT.
NRLY WINDS...DEBRIS CLOUD COVER...AND EARLY SEABREEZE FORMATION
SHOULD KEEP MAX TEMPS IN THE U80S. MODELS DO NOT INDICATE ANY SIG
SFC DRY AIR ADVECTION WITH MOS OUTPUT KEEPING SFC DEWPOINTS IN THE
L/M70S...MIN TEMPS WILL REFLECT THIS.
SAT-SUN...
MID LEVEL TROUGH AXIS STARTS OUT OVER THE EASTERN GULF OF MEXICO ON
SATURDAY THEN SHIFTS EASTWARD ACROSS FLORIDA ON SUNDAY. AT
SURFACE...THE AXIS OF SURFACE HIGH PRESSURE REMAINS SOUTH OF CENTRAL
FLORIDA AND RESULTS IN CONTINUED SOUTHWEST TO WEST FLOW BOTH DAYS.
THE NAM12 IS MORE AGGRESSIVE IN SHOWING AN AREA OF LOW PRESSURE OVER
NORTHERN BAHAMA ISLANDS WHILE THE GFS IS SHOWING A MUCH BROADER AREA
OF LOWER PRESSURES EXTENDING FROM THE SOUTHEAST UNITED STATES AND
NOT QUITE REACHING THE NORTHERN BAHAMA ISLANDS. WILL LEAN TOWARD THE
SLIGHTLY WEAKER 26/00Z GFS SOLUTION FOR THIS FORECAST CYCLE AND THAT
THE 25/12Z NAM12 DID NOT SHOW ANY CLOSED ISOBARS AND THE 25/18Z RUN
WAS SHOWING A WEAK CLOSED LOW OVER GRAND BAHAMA. CHANCE POP OF 30 TO
50 PERCENT NORTH TO SOUTH LOOKS REASONABLE. HIGHS UPPER 80S/LOW 90S.
LOWS LOW/MID 70S.
MON-THU...
UPPER LEVEL TROUGH FLATTENS OVER THE SOUTHEAST MONDAY AND FINALLY
LIFTS NORTH TUE-THU. SURFACE HIGH PRESSURE SHIFTS NORTHWARD TO SOUTH
FLORIDA MONDAY AND NORTH OF CENTRAL FLORIDA TUESDAY AND REMAINS
NORTH CENTRAL FLORIDA THROUGH FRIDAY. LIGHT SOUTH TO SOUTHWEST FLOW
EARLY MONDAY TRANSITIONS TO ONSHORE MONDAY NIGHT AND REMAINS ONSHORE
THE REST OF THE WEEK. GFS MODEL TIME HEIGHT CROSS SECTION FORECASTS
OF MOISTURE SHOWS MOST OF THE MOISTURE CONFINED TO 850MB/5000 FEET
AND BELOW. MEX MOS POP NUMBERS RESPOND WITH GENERALLY 30 POP DURING
THE DAY AND 20 OVERNIGHT. THE ONSHORE FLOW WILL TEND TO PUSH PRECIP
QUICKLY ACROSS THE COAST DURING THE MORNING AND THE INTERIOR DURING
THE AFTERNOON. TEMPERATURES RANGE FROM THE UPPER 80S/LOW 90S DURING
THE DAY AND LOW/MID 70S OVERNIGHT.
&&
.AVIATION...
THRU 26/14Z...SCT MVFR SHRAS/IFR TSRAS S OF KMLB-KLAL....LCL MVFR
CIGS BTWN KMLB-KLAL AND THE I-4 CORRIDOR. BTWN 26/14Z-26/16Z...SFC
WNDSHFT FM W/NW TO NE AOB 12KTS ALONG THE COAST BTWN KOMN-KMLB WITH
THE FORMATION OF THE EAST COAST SEAS BREEZE. BTWN 26/16Z-26-24Z...
SEABREEZE MVG INLAND WITH WNDSHFT FROM NW TO NE AOB 12KTS
KMCO/KSFB/KISM ARND 20Z...ISOLD MVFR SHRAS E OF KLEE-KISM-KMLB...
SCT MVFR SHRAS/ISOLD IFR TSRAS S OF KLEE-KISM-KMLB. BTWN
27/00Z-27-02Z...ISOLD SHRAS/TSRAS S OF KVRB-KOBE. AFT 27/02Z VFR ALL
SITES.
&&
.MARINE...
TODAY-TONIGHT...TROF AXIS PUSHING THRU CENTRAL FL WILL FORCE SFC
WINDS TO VEER TO THE N/NE THRU THE DAY...THOUGH W/SW WINDS WILL
CONTINUE S OF SEBASTIAN INLET INTO EARLY AFTN. WEAK PGRAD WILL KEEP
WIND SPEEDS AOB 12KTS. SEAS AOB 2FT. SCT SHRAS/ISOLD TSRAS MOVING
OFFSHORE S OF CAPE CANAVERAL THRU LATE MORNING.
SAT-SUN...PERSISTENT 10 TO 15 KNOT OFFSHORE FLOW BOTH DAYS. SEAS 1
TO 2 FEET NEARSHORE AND 3 TO 4 FEET OFFSHORE.
MON-TUE...WINDS SHIFT TO THE SOUTH OVERNIGHT SUNDAY AND EARLY MONDAY
THEN SOUTHEAST MONDAY AFTERNOON AS A RESULT OF THE SURFACE RIDGE
AXIS MOVING NORTHWARD UP THE PENINSULA. MODERATE SOUTHEAST WINDS
CONTINUE TUE. THE WAVE WATCH MODEL HINTING AT A SMALL BUT INCREASING
LONG PERIOD SWELL STARTING LATE MONDAY AND LASTING THROUGH THURSDAY
THEN DECREASING PERIODS STARTING FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 88 73 89 73 / 20 10 30 20
MCO 89 73 92 73 / 20 10 30 20
MLB 86 74 88 73 / 30 10 40 20
VRB 87 74 88 72 / 30 10 40 20
LEE 91 73 93 75 / 20 10 40 20
SFB 89 73 93 74 / 20 10 30 20
ORL 89 73 93 75 / 20 10 30 20
FPR 87 74 89 72 / 30 20 50 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...WIMMER
AREA FORECAST DISCUSSION
NWS MIAMI FL
231 AM EDT FRI JUL 26 2013
...VERY WARM TO HOT DAY CONTINUES ACROSS EAST COAST METRO AREAS TODAY...
...RETURN TO MORE TYPICAL SUMMERTIME WEATHER BY THIS WEEKEND INTO EARLY NEXT WEEK...
.SHORT TERM...
A MID TO UPPER LEVEL LOW OVER THE MID ATLANTIC STATES WILL MOVE
EAST TODAY INTO THE NORTHERN ATLANTIC WATERS ALLOWING FOR A TROUGH
OF LOW PRESSURE OVER CENTRAL FLORIDA TO MOVE INTO THE LAKE
OKEECHOBEE AREA. THIS WEATHER PATTERN WILL KEEP A SOUTHWEST
STEERING FLOW IN PLACE OVER SOUTH FLORIDA TODAY ALONG WITH SOME
DEEPER MOISTURE WORKING INTO THE AREA FROM THE NORTH. SO POPS
TODAY WILL RANGE 20 PERCENT OVER THE EXTREME SOUTHERN AREAS TO 50
PERCENT OVER LAKE OKEECHOBEE AND PALM BEACH COUNTY TODAY.
THE SOUTHWEST STEERING FLOW WILL ALSO ALLOW FOR ANOTHER VERY WARM
TO HOT DAY OVER THE EASTERN AREAS OF SOUTH FLORIDA. MORE ON THE
HOT TEMPERATURES IN THE CLIMATE SECTION BELOW.
THE TROUGH OF LOW PRESSURE WILL BREAK DOWN TONIGHT OVER THE LAKE
OKEECHOBEE AREA ALLOWING FOR THE HIGH OVER THE FLORIDA STRAITS TO
WORK NORTH INTO SOUTH FLORIDA THIS WEEKEND. THIS WILL ALLOW FOR
THE STEERING FLOW TO BECOME MORE SOUTHERLY OVER THE AREA THIS
WEEKEND...WHICH IN TURN WILL FOCUS THE SHOWERS AND THUNDERSTORMS
MORE OVER THE LAKE OKEECHOBEE REGION. SO THE HIGHEST POPS WILL BE
AROUND THE LAKE OKEECHOBEE REGION THIS WEEKEND...BUT ALL AREAS OF
SOUTH FLORIDA COULD STILL SEE SCATTERED SHOWERS AND THUNDERSTORMS.
.LONG TERM...
THE RIDGE OF HIGH PRESSURE WILL THEN SHIFT INTO CENTRAL FLORIDA
FOR THE EARLY TO MIDDLE PART OF NEXT WEEK. THIS WILL ALLOW FOR THE
STEERING FLOW TO BECOME MORE EASTERLY OVER THE AREA...AND ALLOW
FOR THE HIGHEST POPS TO BE OVER THE WESTERN AREAS OF SOUTH
FLORIDA. SO WILL SHOW THIS IN THE FORECAST FOR EARLY TO MIDDLE
PART OF NEXT WEEK.
THE LATEST FORECAST FROM THE NATIONAL HURRICANE CENTER (NHC) IS
FOR TROPICAL STORM DORIAN TO BE SOMEWHERE IN THE SOUTHERN BAHAMA
ISLANDS EARLY NEXT WEEK. THE LATEST LONG RANGE MODELS ARE NOW
SHOWING DORIAN TO MOVE MORE WESTWARD TOWARD CUBA LATE NEXT WEEK.
HOWEVER...RESIDENTS AND VISITORS OF SOUTH FLORIDA NEED TO CONTINUE
TO MONITOR THE LATEST FORECAST FROM THE NHC THIS WEEKEND ON THE
TRACK AND INTENSITY OF DORIAN AND REVIEW YOUR SUPPLIES FOR A
TROPICAL SYSTEM.
&&
.AVIATION...
LINE OF SHRAS/TSRAS CURRENTLY ENTERING HIGHLANDS AND OKEECHOBEE
COUNTIES IS EXPECTED TO CONTINUE PUSHING SOUTHWARD OUT AHEAD OF A
WEAK MID LEVEL TROUGH. LATEST HRRR BRINGS THE LINE THROUGH LAKE
OKEECHOBEE OVER THE NEXT FEW HOURS IN A WEAKENING MODE. DO NOT THINK
IT WILL AFFECT ANY TAF SITE ATTM. SOUTHWEST FLOW IS EXPECTED TO
BECOME MORE SOUTHERLY AT THE EAST COAST SITES EARLY THIS AFTERNOON
WITH A FEW SHRAS/TSRAS POSSIBLE WITH DIURNAL HEATING AND SEA BREEZE
INTERACTIONS.
&&
.MARINE...
THE WINDS TODAY WILL BE FROM A SOUTHWEST TO WEST DIRECTION AT 10
TO 15 KNOTS...BEFORE SLOWLY SWINGING TO A SOUTHERLY DIRECTION BY
THIS WEEKEND WITH SPEEDS DECREASING TO 10 KNOTS OR LESS. THIS WILL
KEEP THE SEAS AT 2 FEET OR LESS IN BOTH THE ATLANTIC AND GULF
WATERS THROUGH THE WEEKEND. SO BOATING CONDITIONS SHOULD BE GOOD
FOR ALL SOUTH FLORIDA WATERS THROUGH THIS WEEKEND OUTSIDE OF
ANY SHOWERS AND THUNDERSTORMS.
&&
.CLIMATE...
HERE ARE THE FORECAST HIGHS AND RECORD HIGHS FOR THE EAST COAST
METRO SITES FOR TODAY:
CITIES FORECAST HIGHS RECORD HIGHS
MIA 94 97 - 1983
FLL 93 95 - 1983
PBI 94 99 - 1983
MIA BEACH 92 93 - 1969
SO WILL MENTION NEAR RECORD HIGHS FOR THE EAST COAST METRO ZONES
FOR TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 94 76 91 76 / 50 30 50 30
FORT LAUDERDALE 93 78 91 78 / 30 20 40 20
MIAMI 94 77 90 77 / 30 20 40 20
NAPLES 90 77 89 76 / 40 10 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...54/BNB
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1141 PM CDT THU JUL 25 2013
.DISCUSSION...
ISSUED 900 PM CDT THU JUL 25 2013
EAST-WEST AREA OF SHOWERS/STORMS IS DROPPING SOUTHWARD ACROSS IOWA
AND SOUTHWEST WISCONSIN...WITH A WING OF SCATTERED STORMS
INCREASING OVER SOUTHEAST IOWA DURING THE LAST HOUR OR SO.
QUESTION REMAINS AS TO HOW FAR SOUTHEAST THIS WILL PENETRATE THE
CWA OVERNIGHT. EVENING SOUNDINGS FROM LINCOLN AND DAVENPORT SHOW A
FAIR AMOUNT OF DRY AIR THAT NEEDS TO BE SATURATED FIRST...WITH
SOME MOISTURE ADVECTION ALREADY ONGOING WITH DEW POINTS INTO THE
60-65 RANGE OVER A GOOD PORTION OF THE FORECAST AREA. NEWLY-
ARRIVED EVENING NAM MODEL KEEPS THE RAIN OUT OF THE CWA THROUGH
SUNRISE...WHILE THE RAP AND HRRR SHOW SOME POST-MIDNIGHT ACTIVITY
ALBEIT ON THE DECREASE. THINK THE PROXIMITY OF THE STORMS IN
SOUTHEAST IOWA WARRANTS A MINOR BUMP IN RAIN CHANCES ACROSS THE
FAR NORTHWEST CWA...BUT HAVE KEPT THE CWA DRY EAST OF THE ILLINOIS
RIVER OVERNIGHT. HAVE ALSO INCREASED THE SKY COVER AS THE CIRRUS
THICKENS QUICKLY...ALTHOUGH THE SOUTHEAST CWA IS STILL EXPECTED TO
LARGELY BE PARTLY CLOUDY. TEMPERATURES ONLY REQUIRED SOME MINOR
ADJUSTMENTS...MAINLY TO THE HOURLY TRENDS.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 1140 PM CDT THU JUL 25 2013
MAIN QUESTION CONTINUES TO BE WITH TIMING OF SHOWER AND
THUNDERSTORM CHANCES. CONVECTION IN EASTERN IOWA IS RUNNING INTO A
BIT OF A WALL WITH A DECENT AMOUNT OF DRY AIR OVER CENTRAL
ILLINOIS. AS SUCH...CURRENTLY THINK THE PERIOD THROUGH 12Z WILL BE
DRY AT THE TAF SITES. HAVE INTRODUCED A 5 TO 8 HOUR PERIOD OF
PREVAILING SHOWERS WITH VCTS AT KPIA/KBMI/KSPI ON FRIDAY AHEAD OF
THE COLD FRONT...BUT FORECAST SOUNDINGS FURTHER EAST DO NOT REALLY
MOISTEN UP UNTIL EARLY TO MID AFTERNOON...SO LEFT VCTS MENTION AT
KDEC/KCMI. THE FRONT ITSELF WILL BE CROSSING THE TAF SITES IN THE
00-06Z TIME FRAME...WITH THE NAM MODEL SHOWING SOME POTENTIAL FOR
A NARROW BAND OF CONVECTION IMMEDIATELY ALONG IT.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1150 PM CDT THU JUL 25 2013
.SYNOPSIS...
ISSUED AT 311 PM CDT THU JUL 25 2013
12Z UA ANALYSIS HAS AN 850MB LOW NORTHWEST OF LAKE SUPERIOR AND
ANOTHER IN WESTERN NEBRASKA. A WARM FRONT RAN FROM THE NEBRASKA
850MB LOW INTO NORTHWEST IOWA BEFORE TURNING SOUTH. MOISTURE WAS
POOLED IN THE NORTHERN AND CENTRAL PLAINS NEAR THE 850MB LOW AND
WARM FRONT FROM NOCTURNAL STORMS.
SATELLITE TRENDS THROUGH MID AFTERNOON SHOW NEW CONVECTION HAS
DEVELOPED FROM SOUTHERN MINNESOTA INTO WESTERN WISCONSIN ALONG WITH
A PERSISTENT CLUSTER OF STORMS FROM NEBRASKA INTO NORTHEAST KANSAS.
18Z SFC ANALYSIS HAS WEAK LOWS FROM SOUTHWEST MINNESOTA INTO
SOUTHERN SOUTH DAKOTA WITH A SLIGHTLY STRONGER LOW IN EASTERN
COLORADO. A WARM FRONT RAN FROM NORTHWEST KANSAS INTO LOUISIANA. DEW
POINTS WERE IN THE 50S ACROSS THE GREAT LAKES WITH 60S FROM
WISCONSIN INTO THE PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 311 PM CDT THU JUL 25 2013
SATELLITE AND RADAR TRENDS SHOW CONVECTION NORTH OF THE CWFA AND
WELL SOUTHWEST OF THE CWFA. THE RAP TRENDS AND OTHER MODELS OF A
POSSIBLE SCENARIO OF CONVECTION NORTHEAST AND SOUTHWEST OF THE CWFA
TONIGHT MAY BE STARTING TO PLAY OUT. HOWEVER...RADAR DOES SHOW WEAK
CONVECTION DEVELOPING ACROSS NORTHERN IOWA AND ALONG THE MISSOURI
RIVER NEAR KOMA. THE MCS TOOL SUGGESTS ISOLATED TO SCATTERED
CONVECTION MOVING/DEVELOPING ACROSS THE NORTHWEST CWFA DURING THE
EVENING AND POSSIBLY BECOMING LOOSELY ORGANIZED LATE TONIGHT.
THE SIGNAL FOR A SUBSTANTIAL MCS DEVELOPING IN THE PLAINS AND
DROPPING SOUTHEAST OVERNIGHT IS STILL THERE IN ALL THE MODELS. IF
CORRECT...THIS MCS WOULD INTERCEPT THE MOISTURE INFLOW INTO THE AREA
AND THUS LIMIT THE POTENTIAL FOR RAIN. THOSE AREAS THAT DO SEE RAIN
OVERNIGHT MAY SEE AMOUNTS RANGING FROM 0.25 TO 0.50 INCHES.
CONVECTION THAT DEVELOPS TONIGHT WILL BE ACROSS THE AREA FRIDAY
MORNING WITH THE BETTER CHANCES OVER THE NORTHEAST CWFA WHERE BETTER
FORCING EXISTS. THE RAIN WILL END FROM WEST TO EAST DURING THE DAY
AS THE FRONT MOVES THROUGH WITH LINGERING CONVECTION OVER THE
SOUTHEAST HALF OF THE CWFA BY LATE AFTERNOON. CLOUD COVER MAY
INITIALLY SUPPRESS TEMPERATURES DURING THE DAY BUT CLEARING IN THE
AFTERNOON SHOULD PUSH TEMPERATURES INTO THE 75 TO 80 DEGREE
RANGE. ..08..
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 311 PM CDT THU JUL 25 2013
A CLOSED UPPER LOW WILL REMAIN OVER THE WESTERN GREAT LAKES THROUGH
LATE SATURDAY THEN MOVES SLOWLY EAST REACHING NORTHERN MICHIGAN BY
SUNDAY EVENING. THE COLD FRONT ASSOCIATED WITH THE UPPER LOW SHOULD BE
NEAR THE MISSISSIPPI RIVER BY 00Z SATURDAY AND EAST OF THE FORECAST
AREA BY 06Z SATURDAY WITH BEST MID/UPPER FORCING AHEAD OF THE UPPER
TROF SHIFTING EAST OF THE FORECAST AREA BY 06Z. THIS SUPPORTS
THE GOING FORECAST OF SLIGHT CHANCE POPS EAST FRIDAY EVENING THEN
DRY AFTER MIDNIGHT. THE REST OF THE WEEKEND LOOKS DRY WITH NORTH TO
NORTHWEST FLOW DOMINATING THE REGION. SATURDAY AFTERNOON/EVENING
WILL HAVE TO WATCH THE NORTHEASTERN CWFA FOR POTENTIAL DIURNAL SHRA
AS THE H5 COLD POOL MOVES THROUGH. NEAR RECORD TEMPS FOR SATURDAY
AND SUNDAY MORNING STILL LOOK ON TRACK. KEPT SATURDAYS LOWS ON THE
WARM SIDE OF GUIDANCE WITH THE POTENTIAL FOR SOME COLD AIR SC MOVING
THE THROUGH FRIDAY NIGHT. FORECAST MINS FOR SATURDAY STAY JUST ABOVE
THE RECORDS. SUNDAY LIGHTER SURFACE WINDS AND LESS OF THREAT OF
SIGNIFICANT CLOUD COVER SUPPORTS COOLER MINS THAN SATURDAY AND A
BETTER POTENTIAL OF REACHING RECORD MINS. THE COOL AIRMASS WILL
KEEP HIGHS SATURDAY AND SUNDAY IN THE LOW TO MID 70S. NORMALS HIGHS
FOR LATE JULY ARE IN THE LOW TO MID 80S.
THE GREAT LAKES REGION UPPER LOW WILL DRIFT NORTHEAST INTO EASTERN
CANADA BY MID TO LATE WEEK AS WESTERLY MID LEVEL FLOW SPREADS EAST
INTO THE CENTRAL U.S. A S/W ON THE LEADING EDGE OF THE WESTERLY
FLOW REGIME IS PROGGED TO MOVE THROUGH THE CENTRAL U.S. MONDAY AND
TUESDAY. MODELS ARE IN GOOD AGREEMENT DEVELOPING A PLAINS MCS IN
THE RETURN FLOW AHEAD OF THE S/W AND MOVING THE MCS EAST INTO THE
MID MISSISSIPPI VALLEY LATE MONDAY NIGHT OR TUESDAY. THE 12Z
GFS/GEM BROUGHT THE BULK OF THE PRECIP WITH THIS SYSTEM THROUGH IA
AND NORTHERN ILLINOIS WHILE THE 12Z ECMWF WAS A TAD SOUTH FOCUSING
MORE ON NORTHERN MO AND SOUTHERN IA INTO CENTRAL AND SOUTHERN IL.
WITH ALL OF THE MODELS HITTING SOME PART OF THE FORECAST AREA HAVE
UPPED POPS TO HIGH CHANCE OR LIKELY WITH THE HIGHEST POPS MONDAY
NIGHT. THE GFS/ECMWF SUGGEST ANOTHER S/W MOVING THROUGH BY THURSDAY
BUT THE FEATURES LOOK WEAK AT THIS TIME SO SLIGHT CHANCE OR LOW
CHANCE POPS ARE MENTIONED FOR NOW. TEMPERATURES WILL BE ON A
GRADUAL WARMING TREND THROUGH THE WEEK AND SHOULD BE BACK TO NEAR
NORMAL FOR EARLY AUGUST BY WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1146 PM CDT THU JUL 25 2013
THUNDERSTORM COMPLEX MOVING ACROSS THE MID MISSISSIPPI VALLEY
OVERNIGHT WILL CONTINUE TO PROGRESS EASTWARD...AFFECTING ALL AREA TAF
SITES THROUGH 15Z. MAINLY MVFR WITH SOME LOCAL IFR CONDITIONS CAN
BE EXPECTED THROUGH EARLY MORNING WITH THIS COMPLEX. BEYOND
THAT...A COLD FRONT NOW OVER MINNESOTA WILL PUSH ACROSS IOWA AND
INTO ILLINOIS FRIDAY MORNING...CLEARING ALL TAF SITES BY 19Z. AS
THE FRONT PASSSES...THE WIND WILL SHIFT TO THE NORTH AND RAIN AND
THUNDER CHANCES WILL DIMINISH.
&&
.CLIMATE...
ISSUED AT 311 PM CDT THU JUL 25 2013
RECORD LOWS FOR JULY 27...
MOLINE.........50 IN 1962+
CEDAR RAPIDS...48 IN 1937
DUBUQUE........48 IN 1971
BURLINGTON.....49 IN 2004+
RECORD LOWS FOR JULY 28...
MOLINE.........52 IN 1925
CEDAR RAPIDS...47 IN 1925
DUBUQUE........51 IN 2005+
BURLINGTON.....53 IN 1981
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DLF
AVIATION...DMD
CLIMATE...14
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1130 PM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 1130 PM CDT THU JUL 25 2013
CONFIDENCE IN THE FORECAST POPS FOR NORTHEAST KS HAS WANED A
LITTLE SINCE MUCH OF THE CONVECTION IN SOUTHEASTERN NEB HAS FALLEN
APART. THE HRRR FLIPS BACK AND FORTH BETWEEN WIDESPREAD PRECIP AND
SCATTERED STORMS WHILE THE RUC AND NAM CONTINUE THEIR BULLISH QPF
PROG. THERE HAS RECENTLY BEEN SOME NEW CONVECTIVE DEVELOPMENT
ACROSS REPUBLIC COUNTY AND THE RAP AND NAM CONTINUE TO SHOW
ISENTROPIC LIFT ACROSS NORTHEAST KS WITH THE SOUTHWESTERLY 850
FLOW. SO AT THIS POINT WILL STICK WITH THE FORECAST. GIVEN THE
WEAK INSTABILITY...HAVE TONED DOWN THE MENTION OF THUNDER
EXPECTING MAINLY RAIN WITH EMBEDDED THUNDERSTORMS.
UPDATE ISSUED AT 557 PM CDT THU JUL 25 2013
BASED ON 22Z OBS AND OBJECTIVE STREAM LINE ANALYSIS..IT APPEARS AS
THOUGH THE DEEP MOIST CONVECTION IS OCCURRING WITHIN THE AREAS OF
LOW LEVEL CONVERGENCE. FOR THE IMMEDIATE FUTURE...THIS WOULD FAVOR
CONVECTION STAYING GENERALLY SOUTH OF I-70. THE NAM AND RAP SHOW A
LOW LEVEL JET PERSISTING FROM THE SOUTH AND SOUTHWEST AHEAD OF THE
SYNOPTIC COLD FRONT WITH SOME ISENTROPIC UPGLIDE. SO WHILE THE
BETTER SHORTWAVE FORCING MAY END UP SKIRTING THE SOUTHWESTERN
PORTIONS OF THE FORECAST AREA...THINK STORMS THAT FILL IN THE GAP
ALONG THE FRONT IN NEB FROM THE MO RIVER TO NORTHWEST KS SHOULD
PERSIST AND MOVE THROUGH MUCH OF NORTHEAST KS. WILL MONITOR TRENDS
FOR A LITTLE WHILE TO SEE IF IN FACT THIS IS THE CASE...BUT MAY
NEED TO ADJUST POPS UP A LITTLE FOR THE OVERNIGHT HOURS. CHANCES
FOR SEVERE WEATHER LOOK TO BE THE HIGHEST THIS EVENING WITH
REASONABLE MID LEVEL LAPSE RATES SUGGESTING SOME ELEVATED
INSTABILITY AND DEEP LAYER SHEAR AROUND 30 KTS SUPPORTIVE OF SOME
ORGANIZATIONS. HOWEVER MODELS TEND TO SHALLOW UP THE LAPSE RATES
AFTER MIDNIGHT. HOPEFULLY THIS MEANS WE WILL JUST GET SOME
BENEFICIAL RAINFALL.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 354 PM CDT THU JUL 25 2013
SEVERAL FORCING MECHANISMS COMING INTO PLAY FOR HIGH PRECIPITATION
CHANCES THROUGH EARLY FRIDAY. UPPER LEVEL JET WAS ROTATING
ANTICYCLONICALLY AROUND THE GREAT BASING RIDGE AND INTO CENTRAL
COLORADO AT 12Z WITH 40-50M HEIGHT FALLS /HIGH FOR JULY/ AT THE
WESTERN NEBRASKA VICINITY RAOBS. WEAK RIDGING AT 700MB AND 850MB
OVER THE CENTRAL PLAINS LEADING TO MODEST WARM AIR ADVECTION WITH
INCREASING MOISTURE LEADING TO SCATTERED TO WIDESPREAD BUT MOSTLY
MODEST CONVECTION IN NORTHEASTERN KANSAS TODAY. 20Z OBSERVATIONS AND
PRESSURE CHANGES SUGGEST A COLD FROM FROM EAST CENTRAL COLORADO TO
NORTHEAST NEBRASKA...WITH VEERING UPPER LEVEL WINDS ON THE
PLATTEVILLE COLORADO WIND PROFILER. MIXED LAYER CAPE REMAINS RATHER
LIMITED WITH VALUES IN THE 1000 J/KG RANGE.
WARM AIR ADVECTION TO GRADUALLY SHIFT TO SHORTWAVE AND FINALLY
FRONTAL FORCING THROUGH FRIDAY MORNING AS PRECIPITABLE WATER LEVELS
RISE. SOME QUESTIONS REMAIN IF STRONGER LOW LEVEL FORCING AND
INSTABILITY IN SOUTHWEST KANSAS WILL KEEP THE BULK OF WIDESPREAD
PRECIP TO THE SOUTH SO KEPT SOME UNCERTAINTY IN THE PRECIPITATION
CHANCES. SEVERE CHANCES SEEM SOMEWHAT LOW GIVEN MARGINAL INSTABILITY
AND ONGOING COVERAGE OF CONVECTION LIMITING FURTHER INSOLATION.
PRECIP SHOULD END BY EARLY AFTERNOON FOR THE AREA AS THE FRONT
SHIFTS SOUTH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 354 PM CDT THU JUL 25 2013
FRIDAY NIGHT HIGH PRESSURE WILL BUILD INTO EASTERN KANSAS AND WILL
LOWER HUMIDITY AND YIELD LOWS IN THE 50S. SATURDAY LOOKS TO REMAIN
DRY FOR THE MOST PART, BUT WITH THE APPROACH OF A MID LEVEL WAVE
DEVELOPING CONVECTION IN NEBRASKA MAY SEE SOME SHOWERS OR
THUNDERSTORMS IN NORTH CENTRAL KANSAS. HIGHS SATURDAY WILL BE BELOW
NORMAL WITH READINGS IN THE UPPER 70S TO LOWER 80S.
SATURDAY NIGHT THUNDERSTORMS DEVELOPING IN THE HIGH PLAINS WILL MOVE
SOUTHEAST IN NORTHWEST FLOW ALOFT AND MAY CLIP THE WESTERN SECTIONS
OF THE CWA AFTER 09Z SUNDAY. PRECIPITATION CHANCES WILL INCREASE
SUNDAY AS A MID LEVEL WAVE MOVES EAST OUT OF THE ROCKIES AND
CONTINUES EASTWARD IN ZONAL FLOW ACROSS THE CENTRAL PLAINS. BEST
CHANCES WILL BE FROM THE AFTERNOON SUNDAY THROUGH SUNDAY NIGHT.
ANOTHER WAVE WILL MOVE ACROSS THE STATE ON MONDAY. GOOD MOISTURE
TRANSPORT EXPECTED SUNDAY NIGHT AND MONDAY EAST OF A SURFACE TROUGH
IN THE WESTERN HIGH PLAINS. THIS MAY LEAD TO SOME LOCALLY HEAVY
RAINFALL ESPECIALLY IN EAST CENTRAL KANSAS WHERE PRECIPITABLE WATER
WILL BE THE HIGHEST. LOW LEVEL JET WILL INTERACT WITH A FRONTAL
BOUNDARY MONDAY NIGHT AND TUESDAY MORNING. BY TUESDAY AFTERNOON THE
FORCING AND MOISTURE WILL MOVE OFF TO THE SOUTHEAST AND EAST WITH
THE FRONT SO WILL KEEP MORNING SHOWERS BEFORE DRYING OUT AGAIN.
NEXT WEDNESDAY SOME WEAK FORCING MAY BRING A SMALL CHANCE OF
THUNDERSTORMS TO THE AREA AS THEY ADVECT IN FROM THE WEST IN A NEARLY
ZONAL FLOW ALOFT. BETTER CHANCES COME NEXT THURSDAY AS MOISTURE
RETURNS AHEAD OF A DEVELOPING SURFACE TROUGH IN THE HIGH PLAINS WITH
AN MCS DEVELOPING IN THE HIGH PLAINS AND MOVING INTO EASTERN KANSAS.
TEMPERATURES WILL WARM FROM THE 80S TO LOWER TO MID 90S FROM MONDAY
THROUGH THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1130 PM CDT THU JUL 25 2013
WILL MAINTAIN THE CURRENT FORECAST WITH THE 00Z NAM AND THE 03Z
RAP CONTINUING TO SHOW SHOWERS AND STORMS OVERSPREADING THE AREA.
IT LOOKS LIKE THE PERIOD FROM 07Z TO 13Z WILL BE THE MOST LIKELY
TIME FOR SOME MVFR CIGS AND VSBY IF PRECIP HOLD TOGETHER. BOTH THE
RAP AND NAM HANG ONTO THE MVFR CIGS THROUGH MUCH OF THE MORNING
FRIDAY SO HAVE NOT CHANGED THE TIMING OF THE FORECAST SCATTERING
OUT TO VFR.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...65
LONG TERM...53
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
111 AM EDT FRI JUL 26 2013
.SYNOPSIS...
ISSUED AT 409 PM EDT THU JUL 25 2013
HIGH PRESSURE IS PULLING OFF TO THE NORTHEAST THIS EVENING...
ALLOWING A STORM SYSTEM THAT IS ORGANIZING OVER THE PLAINS TO TAKE
AIM ON THE GREAT LAKES. THIS AREA OF LOW PRESSURE WILL MOVE OVER
THE AREA TONIGHT AND INTO FRIDAY...GENERATING BELOW NORMAL
TEMPERATURES AND MUCH NEEDED RAINFALL ACROSS NORTHERN MICHIGAN.
THIS STORM SYSTEM WILL MOVE SLOWLY...KEEPING UNSETTLED AUTUMN LIKE
WEATHER IN THE AIR THROUGH THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1033 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: CONVECTION-INDUCED VORT MAX CONTINUES TO SPAWN
ADDITIONAL CONVECTION ALONG ADVANCING DEEP MOISTURE PLUME. OVER
THE PAST HOUR...EASTERN EDGE OF CONVECTION HAS HAD TROUBLE MAKING
MUCH EASTWARD PROGRESS...BUT IS FINALLY BEGINNING TO MOVE AS OF
THIS WRITING. THUS...WILL CONTINUE TO UP POPS FOR THE
OVERNIGHT...WITH CATEGORICAL FOR THE TIP OF THE MITT/EASTERN
UPPER...AND TAPERING OFF AS YOU HEAD SOUTH /PARTICULARLY SOUTH OF
M-32/ WHERE DRY AIR WILL LIKELY BE ABLE TO HOLD ON FOR MOST OF THE
NIGHT. LIGHTNING HAS BEEN GRADUALLY COMING DOWN CONVECTION HEADS
EAST IN TO MORE STABLE AIRMASS...AND FULLY EXPECT THIS TREND TO
CONTINUE.
UPDATE ISSUED AT 934 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: MQT 88D IMAGERY DISPLAYS COMPACT YET IMPRESSIVE
VORT MAX ASSOCIATED WITH STRONG-SEVERE CONVECTION THAT HAS GROWN
SOMEWHAT UPSCALE IN THE PAST TWO HOURS. THIS VORT IS INTERACTING
WITH THE LEADING EDGE OF THE DEEP MOISTURE PLUME TO EXPAND SHOWERS
/AND SOME THUNDER/ INTO WESTERN CHIP/MACK AS OF THIS WRITING.
SATURATION HAS ONLY REACHED DOWN INTO THE MID-LEVELS AT THIS
POINT...BUT AS SOUTHWESTERLY LLJ STRENGTHENS THIS EVENING...EXPECT
ONGOING ECHOES TO EXPAND EAST THROUGH THE TIP OF THE MITT AND THE
REMAINDER OF EASTERN UPPER. WILL UP POPS TO CATEGORICAL IN THESE
AREAS WITH CHANCE /OR LESS/ REMAINING SOUTH OF A TVC-GLR-APN LINE.
MUCAPE PLUME CONTINUES TO MAKE LITTLE/NO EASTWARD PROGRESS...SO
CURRENT TREND OF THUNDER DIMINISHING AS ACTIVITY SPREADS EAST WILL
CONTINUE...WITH NO SEVERE THREAT FORESEEN OVERNIGHT.
UPDATE ISSUED AT 808 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: IMPRESSIVE CONVECTIVE GROWTH OVER CENTRAL UPPER
OVER THE PAST HOUR HAS LED TO AN EXPANDING BAND OF RETURNS
SPREADING EAST TOWARDS CHIP/MACK. WHILE AIRMASS DOWNSTAIRS
CONTINUES TO BE FAIRLY DRY /00Z RAOB IN PROGRESS/ THINK THAT SOME
OF THESE RETURNS WILL REACH THE GROUND OVER THE NEXT 1-2 HOURS AND
HAVE SPED UP POPS HERE ACCORDINGLY. WILL ALSO ADJUST OVERNIGHT
POPS TO SPEED UP EASTWARD PROGRESS OVER EASTERN UPPER AND SLOW IT
TO THE SOUTH OF M-32 IN LINE WITH DEVELOPING CONVECTION OVER
WESTERN UPPER...WHICH SHOULD CONTINUE TO SLIDE EAST GIVEN GOOD
DYNAMIC FORCING...IN TANDEM WITH ARRIVING DEEPER MOISTURE.
DESPITE ONGOING WARNINGS WEST OF LAKE MICHIGAN...SEVERE THREAT
WILL DIMINISH MARKEDLY AS THIS CONVECTION SPREADS EAST. BEST
CHANCE FOR THUNDER WILL COME WELL AFTER MIDNIGHT AS MUCAPE PLUME
OVER WISCONSIN GETS TUGGED NORTH TOWARDS EASTERN UPPER AS
CONVECTIVE DEBRIS PUSHES EAST.
UPDATE ISSUED AT 659 PM EDT THU JUL 25 2013
CHANGES THIS HOUR: PRIMARY CHANGES HAVE BEEN TO NEAR TERM SKY
TRENDS AS MANY SPOTS EAST OF I-75 ENJOYING ONLY A FEW CLOUDS TO
END THE DAY. CONVECTION CONTINUES TO FIRE ALONG LEADING EDGE OF
DEEPER MOISTURE ALOFT WITH MUCAPE PLUME INTERACTING WITH
INCREASING FLOW ALOFT TO PRODUCE A FEW ROBUST CELLS. HRRR WANTS TO
BRING A SLUG OF ACTIVITY IN HERE OVERNIGHT /DECAYING AS IT HEADS
EAST/...BUT NOT READY TO BITE ON THIS YET GIVEN LACK OF
DEVELOPMENT OVER CENTRAL WISCONSIN. THUS...WILL WATCH THE NEXT 1-2
HOURS OF CONVECTIVE EVOLUTION AND MAKE POP ADJUSTMENTS AT THAT
POINT. IF SUBSTANTIAL RAINFALL CANNOT REACH INTO NORTHERN
LOWER...COULD SEE LOW TEMPS NEEDING UPWARD ADJUSTMENT WITH SOME
REMAINING GRADIENT AND TOP-DOWN SATURATION INCREASING CLOUDS
ALOFT.
DESPITE UPSTREAM WARNINGS...SEE LITTLE SEVERE THREAT THIS FAR EAST
AS INSTABILITY PLUME WILL QUICKLY WANE AS IT FOLDS INTO VERY DRY
LLEVEL AIRMASS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
BIG OLE` CHANGES A COMING...AN UNFORTUNATE FACT WELL DISPLAYED ON
AFTERNOON NOAM WATER VAPOR IMAGERY. PATTERN AMPLIFICATION KICKING
INTO FULL GEAR PER SUCH...WITH LEAD CHARGING SHORTWAVE KICKING OUT
OF SOUTHERN MANITOBA...WITH SECONDARY SLUG OF ENERGY JUST UPSTREAM.
THESE WILL EVENTUALLY MORPH INTO AN UNSEASONABLY STRONG UPPER LEVEL
LOW OVER THE NORTHERN LAKES FOR THIS UPCOMING WEEKEND...BRINGING
WITH IT WEATHER MUCH MORE REPRESENTATIVE OF SEPTEMBER THAN JULY.
ATTENDANT SURFACE REFLECTION ATTEMPTING TO TAKE SHAPE...WITH
ELONGATED LOW PRESSURE OVER NORTHERN MINNESOTA AND A DEVELOPING COLD
FRONT ARCHING BACK SOUTHWEST IN THROUGH THE CENTRAL PLAINS.
PRE-FRONTAL MOISTURE ADVECTION NOT OVERLY IMPRESSIVE JUST YET...WITH
ONLY LOWER 60 DEWPOINTS BACK ACROSS THE FAR WESTERN LAKES. AS A
RESULT...UPSTREAM SHOWER AND STORM COVERAGE HAS BEEN SOMEWHAT ON THE
LEAN SIDE...WITH BEST RAIN COVERAGE REMAINING WELL TO OUR NORTH AND
NORTHWEST. FORECAST CONCERNS REMAIN FOCUSED ON INCREASING...AND MUCH
NEEDED...RAIN AND STORM CHANCES THROUGH FRIDAY AS UPSTREAM SYSTEM
FURTHER CONGEALS.
WOULD EXPECT UPWARD TREND IN UPSTREAM RADAR ACTIVITY THIS EVENING AS
INCREASING MOISTURE ADVECTION BECOMES TUCKED UNDER NICE SLUG OF
DEEPENING MID AND UPPER LEVEL SUPPORT. UPSTREAM FORCING/MOISTURE
SPREADS SLOWLY EAST THROUGH THE OVERNIGHT...WITH ATTENDANT THETA-E
RIDGING ARCHING NORTHEAST...BISECTING NORTHERN MICHIGAN BY MORNING.
DIFLUENT MID LEVEL FLOW/UPTICK IN UPWARD QG SUPPORT AND SIMPLE DEEP
LAYER MOISTURE ADVECTION SHOULD SUPPORT UPSTREAM SHOWERS TO SPREAD
EAST...AT LEAST SPREADING ACROSS NORTHWEST SECTIONS OF THE AREA
THROUGH THE OVERNIGHT. SOUTHEAST THIRD OF THE AREA EXPECTED TO
REMAIN DRY...JUST A TOUCH TOO FAR REMOVED FROM BEST JUXTAPOSITION OF
THE ABOVE...ALONG WITH SOME LINGERING SUB H8 DRY AIR. THUNDER
CHANCES NOT OVERWHELMING...BUT NOT ZERO EITHER...WITH CORRIDOR OF
SEVERAL HUNDRED J/KG OF MU CAPE TIED TO ABOVE DYNAMICS. ANY SEVERE
THREAT LIKELY TO REMAIN UPSTREAM WHERE STORMS WILL INITIALLY BE
SURFACE BASED.
DYNAMICS CONTINUE TO RATCHET UP HEADING THROUGH FRIDAY WITH UPSTREAM
SHORTWAVE DEEPENING AND TAKING ON A NEUTRAL/NEGATIVE TILT OVER
WISCONSIN. BACKSIDE CAA STRENGTHENS LOW LEVEL TEMPERATURE
GRADIENT...WITH A RATHER POTENT COLD FRONT TAKING SHAPE JUST
DOWNSTREAM OF PARENT MID LEVEL TROUGH AXIS. LOW PRESSURE DEVELOPING
AND RIDING NORTHEAST ALONG THIS FRONT INTO EASTERN LAKE SUPERIOR
WILL INITIALLY SLOW THE FRONTS EASTWARD PROGRESS FRIDAY
AFTERNOON...LIKELY ONLY REACHING CENTRAL LAKE MICHIGAN BY EVENING.
SHOWERS SHOULD ONLY INCREASE IN COVERAGE...WITH THE
STEADIEST/HEAVIEST RAINS TARGETING EASTERN UPPER/FAR NORTHWEST LOWER
MICHIGAN WHERE STRONGEST DEEP LAYER CONVERGENCE AND MOISTURE
ADVECTION ARE ALIGNED. SEVERE THREAT HIGHLY PREDICATED BY CHANCES
FOR DIURNAL DESTABILIZATION. NOT EXPECTING MUCH OPPORTUNITY FOR
SUCH...WITH CROSS SECTION MOISTURE PROGS SUPPORTING A MOSTLY CLOUDY
DAY...EVEN ACROSS THE RELATIVELY DRY SOUTHERN SIDE OF THE SUNRISE
SIDE. CANNOT COMPLETELY RULE OUT AN ISOLATED SEVERE EVENT...
HOWEVER...WITH SUCH DYNAMICS AND CORE OF NEAR 50 KNOTS DEEP LAYER
SHEAR ACROSS EASTERN UPPER. TEMPERATURES REMAIN RATHER TRICKY GIVEN
RAIN AND ABUNDANT CLOUD COVER. INHERITED HIGHS IN THE UPPER
60S/LOWER-MIDDLE 70S AS GOOD A STARTING POINT AS ANY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 409 PM EDT THU JUL 25 2013
OVERVIEW: HEMISPHERIC PATTERN HAS EVOLVED INTO A 5-WAVE LONG WAVE
CONFIGURATION WITH ONE LONG WAVE TROUGH AXIS STRETCHING DOWN THROUGH
EASTERN NOAM. RIDGING ACROSS THE WESTERN CONUS WHERE THE WARM AIR
RESIDES...LINKING BACK TO TROUGHINESS IN THE GULF OF ALASKA AND THE
EASTERN PACIFIC. 5-WAVE PATTERN FORECAST TO REMAIN ESSENTIALLY
UNCHANGED THROUGH THE UPCOMING SEVEN DAYS BUT WITH SLOW WESTWARD
RETROGRESSION OF THE EASTERN NOAM TROUGH INTO THE PLAINS THROUGH THE
WEEKEND AND INTO NEXT WEEK. SHORT WAVE TROUGH AND POCKET OF SOME
FAIRLY CHILLY AIR STILL SLATED TO SETTLE INTO THE GREAT LAKES FOR
THIS WEEKEND...WHICH WILL BE INTERESTING. WARMER AIR DOES MAKE A
RETURN NEXT WEEK AS THE PATTERN FLATTENS ACROSS THE CONUS...BUT JUST
GETS BACK TO NEAR NORMAL.
FRIDAY NIGHT...TRANSITION PERIOD AS SHORT WAVE TROUGH DEEPENS AND
DIGS INTO THE GREAT LAKES PUSHING A SFC LOW AND COLD FRONT THROUGH
THE REGION. SYSTEM HAS SOME STRONG STORM POTENTIAL WITH A NICE PULSE
OF QG-UPWARD FORCING AND DECENT LOW LEVEL CONVERGENCE ALONG THE
FRONT AND SFC LOW WHICH IS SLATED TO TRACK THROUGH NRN LAKE
MICHIGAN/TIP OF THE MITT/EASTERN UPPER FRIDAY AFTERNOON/EVENING.
COUPLED WITH 30 TO 50 KNOT MID LEVEL WINDS AND RESULTING 0-6KM BULK
SHEAR VALUES IN EXCESS OF 30 KNOTS...ANY STORMS THAT FORM WILL HAVE
POTENTIAL TO GET ORGANIZED. BUT...INSTABILITY IS ONCE AGAIN AN
ISSUE. FORECAST SOUNDINGS (EVEN UNMODIFIED) ARE NOT THAT IMPRESSIVE
IN THE INSTABILITY DEPARTMENT AND EVEN RAW MODEL MLCAPE VALUES ARE
LARGELY UNDER 500 J/KG. NOT GREAT. NO SURPRISE THAT BETTER
INSTABILITY WILL RESIDE ACROSS EASTERN/SOUTHERN WISCONSIN DOWN INTO
LOWER MICHIGAN AND THE OHIO VALLEY AND SUSPECT BETTER ORGANIZED
CONVECTION WILL ONCE AGAIN OCCUR IN THOSE AREAS. THAT SAID...IF WE
CAN GET CONVECTION TO FIRE...ANY STORMS COULD PRODUCE GUSTY WINDS
AND SOME HAIL.
SATURDAY AND SUNDAY...WELCOME FALL. FOLLOWING FROPA...POCKET OF
CHILLY AIR (+3C TO +6C 850 MB AIR) DESCENDS INTO THE GREAT LAKES
SATURDAY SETTLING OVERHEAD FOR SUNDAY. SATURDAY STILL LOOKING LIKE A
TRANSITION DAY AS COLD ADVECTION PROCEEDS THROUGH THE DAY AND PARTS
OF THE CWA (SE COUNTIES) MAY SQUEAK TOUCH THE 70S. COULD ACTUALLY
START THE DAY WITH SOME SUNSHINE AS MID LEVEL DRY SLOT WORKS THROUGH
THE AREA. BUT WITH LAKE SFC TEMPS RUNNING +17C TO +20C...CLOUDY
SKIES ARE CERTAIN TO DEVELOP ALONG WITH AT LEAST A CHANCE FOR HYBRID
LAKE/HEATING INDUCED RAIN SHOWERS SATURDAY AFTERNOON. THAT
SAID...DEPTH OF THE COLD AIR IS NOT TERRIBLY IMPRESSIVE WITH A BIT
OF A WARMER CAPPING LAYER ALOFT WHICH MAY PUT THE BRAKES ON
LAKE/LAND BASED CONVECTION SATURDAY AFTERNOON. HENCE WILL KEEP POPS
ON THE LOW SIDE FOR SATURDAY. SUNDAY LOOKS BETTER FOR SHOWERS AS
WARMER LAYER ALOFT IS ERODED ALONG WITH FLAT OUT CLOUDY SKIES AND A
TRUE FALL-LIKE FEEL. HAVE HIGHS ON SUNDAY RANGING FROM THE MID 50S
TO MID 60S.
WATERSPOUT POTENTIAL...WOULD BE MORE IMPRESSIVE IF THE CONVECTIVE
DEPTH WAS DEEPER (PER SZILAGYI WATERSPOUT NOMOGRAM). WILL STILL
HIGHLIGHT THE CHANCE FOR WATERSPOUTS IN THE HAZARDOUS WEATHER
OUTLOOK AS WELL AS IN THE FORECAST FOR BOTH SATURDAY AND SUNDAY...
BUT THE POTENTIAL DOES NOT LOOK AS GOOD AS IT LOOKED A DAY OR TWO
AGO BY VIRTUE OF THE SHALLOWER COLD AIR.
MONDAY THROUGH THURSDAY...IMPROVEMENT FOR THE START THE NEXT WORK
WEEK WITH HIGH PRESSURE AND LOW AMPLITUDE RIDGING BUILDING ACROSS
THE REGION FOR MONDAY AND TUESDAY...ALONG WITH TEMPS REBOUNDING INTO
THE 70S (STILL BELOW NORMAL). NRN STREAM SYSTEM SLATED TO SLOWLY DIP
INTO THE REGION WEDNESDAY AND THURSDAY...SLOWER THAN IN PREVIOUS
SOLUTIONS. BUT THIS WILL BRING LOW END CHANCES FOR SHOWERS BACK INTO
THE FORECAST TO ROUND OUT THE EXTENDED FORECAST...WITH TEMPS RUNNING
JUST A LITTLE BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 110 AM EDT FRI JUL 26 2013
SUMMARY: LOW PRESSURE NEAR THE WESTERN END OF LAKE SUPERIOR WILL
MOVE EAST THROUGH NORTHERN MICHIGAN TODAY...WITH A STRONG COLD FRONT
ARRIVING THIS EVENING. THIS FRONT WILL BRING OCCASIONAL SHOWERS AND
THUNDERSTORMS TO THE REGION THROUGH THE COMING TAF PERIOD WITH
DETERIORATING FLYING CONDITIONS.
RESTRICTIONS: UNRESTRICTED SHOWERS HAVE REACHED PLN AS OF THIS
WRITING...WITH GRADUALLY INCREASING MID/UPPER LEVEL CLOUDINESS AT
THE OTHER TERMINALS. THROUGH DAYBREAK...BEST SHRA POTENTIAL
CONTINUES TO BE AT PLN /PERHAPS BRUSHING TVC/ BUT EVEN HERE EXPECT
CONDITIONS TO REMAIN PREDOMINATELY VFR. FOR THE DAYTIME
FRIDAY....SHOWERS /AND EMBEDDED THUNDERSTORMS/ WILL INCREASE IN
COVERAGE AND MOVE FROM WEST TO EAST...WITH MVFR CIGS/VSBYS
DEVELOPING BY EARLY AFTERNOON PLN/TVC/MBL AND DURING THE AFTERNOON
AT APN. CIGS WILL LOWER FRIDAY EVENING WITH RAIN TAPERING BACK TO
SHOWERS FRIDAY NIGHT. IFR CIGS POSSIBLE AT PLN AFTER 00Z.
THUNDER: CHANCES ARE GENERALLY LOW...WITH A SOME EMBEDDED THUNDER
POSSIBLE NEAR PLN THROUGH DAYBREAK...WITH ISOLATED THUNDER POSSIBLE
AT EACH OF THE TERMINALS THROUGH THE DAY FRIDAY.
LLWS: 1.5KFT WINDS TO 30KTS WILL CONTINUE THROUGH DAYBREAK BEFORE
SHEAR LAYER MIXES OUT.
WINDS: LIGHT AND VARIABLE WINDS WILL BECOME SOUTH-SOUTHWEST AND
STRENGTHEN TO 10G18KTS FOR THE DAY ON FRIDAY BEFORE SHIFTING
NORTHWEST 10KTS FRIDAY EVENING.
&&
.MARINE...
ISSUED AT 409 PM EDT THU JUL 25 2013
SOUTH WINDS WILL CONTINUE ACROSS THE BIG WATERS TONIGHT INTO
FRIDAY...BUT LOOK TO REMAIN BELOW SCA LEVELS. LONG AND PERSISTENT
SOUTHERLY FETCH WILL RESULT IN SOME CHOPPY WATERS...ESPECIALLY
ACROSS THE NORTH HALF OF LAKE MICHIGAN. WILL NEED TO MONITOR...BUT
THESE ALSO LOOK TO REMAIN JUST BELOW SCA LEVELS. STRONG COLD FRONT
PUSHES ACROSS THE AREA FRIDAY NIGHT. WEST WINDS TO FOLLOW INTO
THIS WEEKEND...AT TIMES GUSTY. WILL NEED TO MONITOR WATERSPOUT
POTENTIAL THIS WEEKEND AS UNSEASONABLY STRONG UPPER LEVEL LOW
PRESSURE WOBBLES OVERHEAD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...BA
AVIATION...ARNOTT
MARINE...MB
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
406 AM CDT Fri Jul 26 2013
.SHORT TERM...(Today through Sunday Afternoon)
Issued at 359 AM CDT FRI JUL 26 2013
Water vapor imagery this morning shows an upper trough deepening
over northern MN. While this feature is expected to slide southeast
the models have continually shown height falls extending further
south. This will eventually manifest itself in cooler air filtering
further south with time. This system will also maintain northwest
flow into Sunday before finally yielding to rising heights over the
Central Plains and a more zonal look to the h5 heights by late in
the weekend.
Today...What had looked to be a promising morning for rain over most
of the CWA is once again proving to be frustrating, just as it has
all week. Convection has broken into two distinct areas. Scattered
convection over northwest MO is related to the southwest extension
of a band of showers and isolated thunderstorms stretching from
northern IL. Models generally agree that this activity will mainly
affect northern MO. The second area of convection is tied to a MCV
now spinning through east central and southeast KS. The northern
portion of the precipitation shield has shown a slow but steady
decrease in intensity and coverage. Prefer weaker and less coverage
shown by the HRRR solution which favors high PoPs only over the
southwestern counties. In between these two areas of precipitation
will keep low chance PoPs going for possible development later this
morning. Also believe isolated convection could form this afternoon
with whatever convergence is generated as a cold front drops south
through the CWA. Clearing from north to south this afternoon will
allow temperatures to rebound into the lower 80s except for the far
southern counties where clouds/rain will keep readings in the upper
70s.
Tonight...Unseasonably cool high pressure will build southward
through the Plains and MO tonight and provide exceptional sleeping
weather.
Saturday through Sunday...Have had to insert some slight to low
chance PoPs over parts of far west central MO and adjacent eastern
KS as the GFS/NAM/ECMWF are now signaling weak perturbations aloft
embedded within the fickle northwest flow aloft will combine with
weak isentropic ascent and banded frontogenesis to wring out some
light showers/isolated storms. The combo of clouds/precipitation and
the abnormally cool surface high will keep temperatures in the 70s
over the weekend. In addition, overnight temperatures both mornings
may threaten record lows.
.LONG TERM...(Sunday Evening through Thursday)
Issued at 359 AM CDT FRI JUL 26 2013
The first half of next week we`ll see very good chances for much
needed rainfall across the area. The best chances look to arrive
Monday evening into Tuesday morning and especially during the
overnight hours. There are several ingredients that really enhance
our chances. The biggest is that there will be a seasonally strong
low level jet nosing right in the Missouri River valley. Ensemble
data suggest this is about 4 standard deviations stronger than
normal for this time of year. We`ll also continue to see
precipitable water values around 2 inches, which is slightly above
normal for this time of year. Models are also in good agreement with
an area of strong isentropic lift and moisture stability flux nosing
into the area Monday night. All this points to very high POPs for
this stretch of time with the potential for a good amount of
precipitation. I actually feel there is a better chance with this
setup than with the northwest flow pattern from last weekend because
of the strength of the LLJ nosing into the area. This is something
that was lacking last weekend. So fingers crossed, a few inches of
rain would go a long way, at this point, to easing the precipitation
deficits we`ve racked up in June and July so far.
With all the likely cloud cover and possible precipitation,
temperatures on Monday should be well below normal across the entire
area. Highs have a strong potential of staying in the 70s. By
Tuesday afternoon, the bulk of the precipitation should be moving
into eastern Missouri with skies clearing from west to east. So we
should be able to climb back to more normal temperatures across
eastern Kansas and western Missouri by the afternoon. It will be
tougher to get to normal in our east as cloud cover and precip may
linger longer into the day.
The next decent chance for rain may come Friday as we once again are
in a northwest flow pattern with weak waves migrating through the
flow. After last weekend though, I`m a little gun shy about going
very high on POPs. The model consensus was to keep things in the
chance category and that sounds reasonable at this point.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1155 PM CDT THU JUL 25 2013
Storms have failed to become organized upstream across Nebraska and
Iowa, although last few radar scans hint at an uptick in activity.
There could still be some increase in storms overnight as the front
responsible for this activity pushes into northwest MO. However
confidence remains low, with chances for any given terminal seeing
thunderstorms running around 30 to 40 percent. Will therefore not
stray from the VCTS group, which is timed about 3 hours before
frontal passage.
&&
.CLIMATE...
Issued at 359 AM CDT FRI JUL 26 2013
Abnormally cool high pressure will approach record low temperatures
Saturday and Sunday mornings.
July 27 July 28
Min/Year Min/Year
Kansas City 55/1994 52/1994
St. Joseph 47/1971 53/2005
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...CDB
AVIATION...Hawblitzel
CLIMATE...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1155 PM CDT Thu Jul 25 2013
.UPDATE...
Issued at 650 PM CDT THU JUL 25 2013
Light rain across the area is encountering a drier and more stable
airmass and continues to weaken. Rainfall amounts were generally
under a quarter of an inch with this activity.
Meanwhile convection continues to develop along a cold front from
western KS into northeast NE and northern IA. These storms are not
quite as robust as several models had predicted, and as the airmass
ahead of them continues to stabilize it may be difficult to maintain
widespread convection overnight into our forecast area. Therefore
trimmed overnight PoPs down into chance category given the
uncertainty.
&&
.SHORT TERM...(This Evening through Friday)
Issued at 345 PM CDT THU JUL 25 2013
A weak short wave trough moving through the northwest flow will
bring a few showers and thunderstorms overnight. The main challenge
will be deciding how much of the area will stay intact as it moves
from Kansas and Nebraska towards Missouri. The HRRR is a little slow
but has the conceptual idea of pattern right so will follow that for
the first period. As the sun sets some of the convection may
diminish and most concentrated area will likely pass to the
southwest of the CWA anyway. Still, the NAM is showing some mid
level lapse rates around 6 K/KM and around 1.5 inches of
precipitable water over extreme eastern Kansas and western Missouri
with lower values to the east. Given the dry conditions at the
surface confidence is still fairly low for any widespread QPF
tonight.
Tomorrow...chances of precipitation will decreas across the area as
short wave trough exits that area. Still will be in northwest flow
and relative humidities drop through the day such that by evening
conditions should be cool and dry with light winds overnight.
Saturday will be picture perfect with low humidities and high
temperatures in the 70s.
.LONG TERM...(Friday Night through Thursday)
Issued at 345 PM CDT THU JUL 25 2013
For the last half of the forecast, below normal temperatures with a
decent chance at rain will be the dominate conditions. Pattern
across the country over the weekend will be dominated by a locally
northwest flow, within the larger amplified pattern in place
across the nation thanks to a cutoff low that will develop over the
Great Lakes this weekend. However, the low is not expected to hang
out for long as by late in the weekend it will have migrated far
enough to the northeast to allow the prevailing flow across the
Plains to return to a zonal pattern.
Over the later half of the weekend, temperatures will remain rather
cool for late July, with highs from the 70s into the 80s. These
pleasant conditions should persist into the work week even as the
zonal flow allows temperatures to moderate up some going into the
work week. Ultimately, the thermal ridge will remain to our west as
the flow adjusts through the beginning of the work week, thus
sparing the region from the oppressively hot temperatures more
typical of late July.
Otherwise, our precipitation chances for early in the work week are
looking rather decent, though persistence considerations leaves
confidence lower than the POPs advertised. As the pattern
flattens out across the nation Sunday night into Monday a shortwave
trough will shift across the center of the nation. Medium range
models have been keying on this shortwave for precipitation, though
the latest runs have slide the periods of focus for the storms from
Sunday night more fully into Monday and Tuesday over the last
several runs. Models continue to robustly advertise storms in these
early work week periods as isentropic lift and moisture transport
spread into Kansas and Missouri, therefore have kept going with
likely POPs for Monday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1155 PM CDT THU JUL 25 2013
Storms have failed to become organized upstream across Nebraska and
Iowa, although last few radar scans hint at an uptick in activity.
There could still be some increase in storms overnight as the front
responsible for this activity pushes into northwest MO. However
confidence remains low, with chances for any given terminal seeing
thunderstorms running around 30 to 40 percent. Will therefore not
stray from the VCTS group, which is timed about 3 hours before
frontal passage.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...Hawblitzel
SHORT TERM...Adolphson
LONG TERM...Cutter
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS HASTINGS NE
404 AM CDT FRI JUL 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT FRI JUL 26 2013
SOME PATCHY FOG HAS DEVELOPED ACROSS THE REGION THIS MORNING IN
RESPONSE TO LIGHT WINDS...CLEARING SKIES...ELEVATED DEW POINTS AND A
STRONG INVERSION. EXPECT THIS FOG TO BECOME MORE WIDESPREAD JUST
BEFORE SUNRISE...ESPECIALLY ACROSS SOUTHWESTERN PORTIONS OF THE
FORECAST AREA THAT RECEIVED SOME MODEST RAINFALL AMOUNTS
THURSDAY/THURSDAY NIGHT AND WHERE WINDS REMAIN LIGHT. LATEST
HRRR/SREF PROBS INDICATE THIS FOG SHOULD BE QUICK TO CLEAR JUST
AFTER SUNRISE...WITH MOSTLY SUNNY SKIES EXPECTED ACROSS ALL AREAS
BY 15Z AT THE LATEST. IN FACT...LATEST HRRR IS NOW QUESTIONING ANY
DENSE FOG DEVELOPMENT IN GENERAL.....BUT WITH SEVERAL SITES
FLIRTING WITH 1-5 SM OF VISIBILITY THE PAST COUPLE OF
HOURS...THINK THAT FURTHER DETERIORATION IS STILL POSSIBLE THROUGH
THE REMAINDER OF THE OVERNIGHT/EARLY MORNING HOURS.
IN WAKE OF THE WEAK COLD FRONT THAT MOVED ACROSS THE REGION
OVERNIGHT...EXPECT TEMPERATURES THIS AFTERNOON TO REMAIN ON THE COOL
SIDE OF CLIMATOLOGY...WITH AFTERNOON HIGHS GENERALLY STRUGGLING TO
REACH 80 NORTH OF INTERSTATE 80...WITH LOWER 80S EXPECTED ACROSS THE
REMAINDER OF SOUTH CENTRAL NEBRASKA AS WELL AS NORTH CENTRAL KANSAS.
IN ADDITION TO THE COOL TEMPERATES...CLEARING SKIES WILL ALLOW FOR
GOOD MIXING ACROSS THE REGION THIS AFTERNOON...WITH OCCASIONALLY
GUSTY NORTHERLY WINDS EXPECTED ACROSS THE LOCAL AREA...RESULTING IN
A MOSTLY SUNNY...YET BREEZY AFTERNOON.
LATEST GUIDANCE IS IN GOOD AGREEMENT MAINTAINING NORTHWESTERLY FLOW
ACROSS THE CENTRAL PLAINS THIS AFTERNOON AND EVENING...AS THE LOCAL
AREA REMAINS IN BETWEEN A LARGE AREA OF LOW PRESSURE ACROSS THE GREAT
LAKES REGION AND AN AREA OF HIGH PRESSURE ACROSS THE DESERT
SOUTHWEST. EXPECT THE NEXT UPPER LEVEL DISTURBANCE EMBEDDED IN THIS
NORTHWESTERLY FLOW TO WORK ITS WAY AROUND THE UPPER LEVEL LOW TO OUR
NORTHEAST LATE TONIGHT...WITH A CHANCE OF SHOWERS AND THUNDERSTORMS
RETURNING TO THE LOCAL AREA AFTER 06Z. WITH GOOD MODEL CONSENSUS
HANDLING THIS DISTURBANCE...INCREASED THE CHANCE FOR PRECIPITATION
POST 06Z AS THE AFOREMENTIONED UPPER LEVEL DISTURBANCE APPROACHES
THE LOCAL AREA.
WHILE THE OVERALL AIRMASS IS EXPECTED TO REMAIN COOL ACROSS THE
REGION OVERNIGHT...CLOUDS ASSOCIATED WITH THE APPROACHING
DISTURBANCE MAY HAVE AN IMPACT ON OVERNIGHT LOWS...BUT CONTINUE TO
THINK LOW TEMPERATURES SATURDAY MORNING WILL BOTTOM OUT IN THE LOWER
TO MIDDLE 50S AT MOST LOCATIONS THANKS TO THE EARLY CLEARING AND
COOL AIRMASS IN PLACE...WHICH WILL BE THE COOLEST MORNING
TEMPERATURE READINGS WE HAVE SEEN SINCE THE BEGINNING OF THE MONTH
WHEN GRAND ISLAND...HASTINGS AND KEARNEY ALL REPORTED LOWS OF 52 ON
THE 1ST OF JULY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 AM CDT FRI JUL 26 2013
ALOFT: NW FLOW WILL CONTINUE SAT-SUN ANCHORED BY AN ERN USA TROF AND
A SLOW-MOVING LOW /-3 STANDARD DEVIATIONS FOR LATE JULY/ OVER THE
GREAT LAKES. THE CLOSED LOW /CURRENTLY SEEN IN WV IMAGERY OVER
BRITISH COLUMBIA/ WILL MOVE INLAND SAT-SUN...SPREADING HGT FALLS
OVER THE WRN USA AND TEMPORARILY SUPPRESSING THE SUBTROPICAL HIGH.
THIS WILL CHANGE THE FLOW OVER THE CNTRL PLAINS TO ZONAL MON-TUE BUT
WITH RISING HGTS AS THE NEXT TROF APPROACHES THE W COAST AND ALLOWS
THE SUBTROPICAL HIGH TO EXPAND N OVER THE SRN USA. THIS WILL THEN
MODIFY THE FLOW TO WNW WED-THU.
THIS PATTERN WILL MAINTAIN BELOW NORMAL TEMPS INTO EARLY NEXT WEEK
WITH A GRADUAL UPWARD TREND...RETURNING TO NEAR NORMAL /UPR 80S TO
LOW 90S/.
SFC: THE COOL FRONT MOVING THRU TODAY WILL BECOME PARALLEL TO THE
UPR FLOW /NW-SE/ FROM THE PANHANDLE THRU CNTRL KS. THIS FRONT WILL
REMAIN STATIONARY THRU MON AND THEN DISSIPATE. COOL HIGH PRES WILL
BE OVER THE PLAINS SAT AND DEPART INTO THE ERN USA SUN. THIS HIGH
WILL FILTER COOLER/DRIER AIR INTO THE REGION. ANOTHER COOL FRONT
WILL DROP INTO THE NRN PLAINS TUE. IT REMAINS UNCERTAIN WHEN THIS
FRONT WILL MOVE INTO THE FCST AREA /THU OR FRI?/ BUT IT WILL
EVENTUALLY BECOME STATIONARY.
WITH LWR HGTS IN PLACE OVER THE LAST FEW DAYS...WE SEEM TO HAVE
ENTERED A MORE ACTIVE PATTERN WITH MUCH BETTER POTENTIAL FOR RAIN
THAN THE 7 WEEK PERIOD FROM JUN 1ST THRU JUL 20TH. THIS MORE
FAVORABLE PATTERN APPEARS TO STICK AROUND THE NEXT FEW DAYS.
HAZARDS: MULTIPLE CHANCES FOR TSTMS. WE ARE NOT SEEING ANY SIGNALS
FOR WIDESPREAD SVR TSTMS. HOWEVER...ISOLATED SVR WILL BE
OCCASIONALLY POSSIBLE. THE MAIN TIME PERIOD TO WATCH WILL BE SUN NGT.
THE DAILY DETAILS...
SAT: FGEN-DRIVEN BANDS OF RAIN WILL PROBABLY BE ON-GOING AT DAWN AND
CONTINUE AT LEAST THRU THE MRNG BEFORE ENDING/EXITING TO THE SE.
THIS LOWERS CONFIDENCE IN HIGH TEMPS IF MODELS ARE OFF IN THEIR
LOCATION OF THE CLOUDS/RAIN.
THE ONLY APPRECIABLE INSTABILITY /SEEN IN MUCAPE/ DOESNT APPEAR TO
BE GREAT ENOUGH TO WARRANT A MENTION OF THUNDER. SO IT HAS BEEN
WITHDRAWN FROM THE FCST. MID-LVL LAPSE RATES ARE FCST TO BE MOIST
ADIABATIC.
QPF: MODELS ARE WIDELY DISPERSIVE WITH THEIR AMTS. IT WILL BE
INTERESTING TO SEE HOW THIS PANS OUT. MOST MODELS SUGGESTS .1 TO .33
FOR THIS EVENT...BUT THE 00Z NAM AND EC SUGGEST A SWATH OF .5" IS
POSSIBLE WITH MAX AMTS OF 0.75" OR MORE. THIS ISNT IN THE BAG YET
AND IT WONT BE FOR EVERYWHERE. THE FACT THE THE EC IS ON BOARD LENDS
CREDENCE TO THE NAM. THIS IS JUST ONE RUN FOR EACH. SO LETS SEE HOW
LATER CYCLES EVOLVE.
H8 TEMPS 2 STANDARD DEVIATIONS BELOW NORMAL AND WITH POTENTIAL FOR
CLOUD COVER MUCH OF THE DAY...THERE IS POTENTIAL FOR RECORD COOLEST
HIGH TEMPS ON RECORD /FOR JUL 27TH/ TO BE THREATENED. THE 64 IN 1981
AT GRI SHOULD BE SAFE...BUT THE CURRENT FCST OF 71 WOULD COME IN AS
THE 2ND COOLEST JUL 27TH ON RECORD.
IF THE "WORST" CASE SCENARIO HAPPENS /CLOUDY ALL DAY WITH STEADY
RAIN THRU EARLY AFTN/ THEN WE MAY BE TOO WARM BY 3-5F IN SOME
LOCATIONS AND NOT HIGH ENOUGH ON CLOUD COVER. ALL MODEL 2M TEMP
GUIDANCE EXCEPT GFS SUGGESTS SOME WONT GET OUT OF THE 60S. IT ALL
DEPENDS WHERE THE RAIN SETS UP. AREAS THAT CAN MAINTAIN THE LEAST
AMT OF CLOUDS COULD APPROACH 80F.
SAT NGT: A FEW TSTMS SHOULD ERUPT ALONG AND ON THE IMMEDIATE COOL
SIDE OF THE FRONT...FROM CNTRL KS NW INTO THE PANHANDLE. A 35 KT LLJ
IS FCST TO DEVELOP WITH ITS NOSE OVER NWRN KS. WITH THE ASSOCIATED
ASCENT OVER THE FRONT...THE REMNANTS OF THESE STORMS COULD DRIFT
INTO AREAS S AND W OF THE TRI-CITIES. AT BEST MUCAPE AROUND 500 J/KG
IS FCST AND THIS IS JUST OVER N-CNTRL KS. SO THUNDER HAS BEEN
REMOVED FROM THE FCST OVER S-CNTRL NEB.
SUN: PROBABLY M/CLOUDY WITH SOME PATCHY LGT RAIN OR SPRINKLES. WE DO
HAVE A CHANCE OF SOME STRATIFORM RAIN IN THE FCST...BUT VERTICAL
MOTION IS WEAK. SO CURRENT EXPECTATION IS FOR LOW QPF. MODELS ARE
MAINTAINING A LARGE BATCH OF HIGH MEAN RH IN THE PERSISTENT PRESENCE
OF THE ENTRANCE REGION OF AN 80 KT ULJ. THERE IS ALSO A HINT OF A
SUBTLE VORT MAX /CURRENTLY OVER AZ AND SRN CA/ WHICH ROUNDS THE
SUBTROPICAL HIGH AND ARRIVES HERE SUN-SUN NGT.
STRENGTHENING RETURN FLOW WILL BEGIN TRANSPORTING RICH MSTR BACK
INTO THE REGION...WITH PW CLIMBING BACK ABOVE 1.5 TO 1.75" AND H8
DWPTS TO +15C.
SUN WILL BE ANOTHER DAY OF MUCH BELOW NORMAL DAYTIME TEMPS.
SUN NGT: HIGH RH REMAINS WITH SUBTLE SHRTWV TROF MOVING THRU. MODELS
ARE EMPHATIC IN MCS DEVELOPMENT...BUT CONFIDENCE IS LOW IN EXACTLY
WHERE. MOST MODELS SUGGESTS KS. A MUCH BROADER/STRONGER LLJ IS FCST
/CLOSE TO 50 KTS/. PW IS FCST TO INCREASE TO 1.90" OVER CNTRL-ERN KS.
THIS COULD END UP AN OPPORTUNITY FOR DRENCHING RAINS FOR PARTS OF
THE FCST AREA.
MON: STILL MUCH BELOW NORMAL TEMPS. A LARGE TSTM COMPLEX WILL BE
EXITING THE REGION AND EXPECT GRADUALLY DECREASING CLOUDS.
TUE: LOOKING DRY AND NICE FOR NOW. TEMPS TAKE A BIG JUMP BACK CLOSE
TO NORMAL.
WED: CHANCE OF AFTN-EVNG TSTMS? COVERAGE IS PROBABLY LOW. TEMPS NEAR
NORMAL.
THU: MAYBE BETTER COVERAGE OF AFTN-EVNG TSTMS? TEMPS NEAR NORMAL.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1236 AM CDT FRI JUL 26 2013
AS SKIES CONTINUE TO CLEAR OVER THE NEXT COUPLE HOURS WITH LIGHT
TO NO WINDS...EXPECT THE POTENTIAL FOR SOME MVFR VSBYS IN AREAS OF
FOG THAT AREA ABLE TO DEVELOP. DID NOT HIT THE FOG POTENTIAL
PARTICULARLY HARD AS RAINFALL TOTALS WERE LIGHT NEAR THE TERMINAL
TODAY...BUT IF FOG IS ABLE TO DEVELOP...COULD SEE IFR CIGS/VSBYS
BEFORE DAYBREAK. OTHERWISE...AS WINDS PICK UP OUT OF THE NORTH
AROUND 13Z...EXPECT ANY FOG THAT IS ABLE TO DEVELOP TO RAPIDLY
SCOUR OUT...WITH GUSTY WINDS TO 20KTS POSSIBLE AFT 15Z.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SAR
LONG TERM...HALBLAUB
AVIATION...SAR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1240 AM CDT FRI JUL 26 2013
.UPDATE...
ISSUED AT 1116 PM CDT THU JUL 25 2013
WENT AHEAD AND TRIMMED POPS A BIT ACROSS THE FORECAST AREA FOR THE
OVERNIGHT HOURS TO REFLECT CURRENT RADAR TRENDS AND SATELLITE
DATA. IN ADDITION...ADDED SOME PATCHY FOG TO SOUTHWESTERN PORTIONS
OF THE FORECAST AREA THAT RECEIVED SOME DECENT RAINFALL TODAY TO
COINCIDE WITH THINKING THAT AS SKIES CLEAR AND WINDS REMAIN
LIGHT...COULD SEE THE POTENTIAL FOR SOME FOG DEVELOPMENT...
ESPECIALLY ACROSS PORTIONS OF NORTH CENTRAL KANSAS. LATEST SREF
INDICATES THIS POTENTIAL AS DOES 02Z HRRR WHICH TAKES VISIBILITIES
DOWN TO 0.25 MILES IN SPOTS. OPTED NOT TO BE THIS
PESSIMISTIC...BUT WILL CONTINUE TO MONITOR POTENTIAL FOG
DEVELOPMENT AS WE GO THROUGH THE OVERNIGHT HOURS TO SEE IF THE
AREA AND DENSITY NEEDS TO BE EXPANDED OR NOT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM CDT THU JUL 25 2013
WATER VAPOR LOOPS REVEAL A POSITIVELY TILTED SHORTWAVE
TROUGH/PERTURBATION WITHIN NORTHWEST FLOW CROSSING NORTHWESTERN
NEBRASKA INTO COLORADO THIS AFTERNOON. AT THE SURFACE...SOME
SCATTERED SHOWER ACTIVITY IS OCCURRING ACROSS THE CWA AS A COMPLEX
SMALL SCALE SURFACE SCENARIO INCLUDING SOME OUTFLOW BOUNDARIES
EXISTS. THIS ACTIVITY IS OCCURRING BETWEEN TWO SYNOPTIC BOUNDARIES.
ONE IS A COLD FRONT TO THE NORTHWEST...LOCATED IN NORTHWESTERN
NEBRASKA...AND THE OTHER IS A STATIONARY FRONT...ONCE A WARM
FRONT...LOCATED IN CENTRAL KANSAS. THESE TWO FEATURES WILL BE FOCI
FOR THUNDERSTORM DEVELOPMENT LATER ON THIS AFTERNOON INTO THE
EVENING. SEVERE CHANCES ARE DICEY. SINCE MOST OF OUR CWA HAS BEEN IN
THE CLOUDS TODAY...THIS HAS KEPT INSTABILITY MORE AT
BAY...DECREASING THE LIKELIHOOD OF SEVERE WEATHER. SOME CONVECTION
HAS ALREADY BEGUN...WITH 1500 TO 2000 J/KG OF CAPE. SHEAR IS RATHER
MARGINAL FOR THE AFTERNOON...AND ACTUALLY DECREASES INTO THE EVENING
HOURS. THERE IS A FAIRLY SMALL WINDOW OF OPPORTUNITY FOR SEVERE
WEATHER TO DEVELOP AS THE WAVE TO THE NORTHWEST MOVES INTO THE
AREA...AND WITH THE SYNOPTIC FRONTS IN THE VICINITY. THE MAIN
SUPPORT FOR SEVERE THREAT...THE SHORTWAVE TROUGH AND
INSTABILITY...WILL DIMINISH BY 10 PM...AFTER SUNSET AND BEHIND THE
WAVE. IN SUMMARY...THE RISK FOR SEVERE WEATHER LOOKS DICEY IF NOT
MEAGER...BUT NOT OUT OF THE QUESTION....ESPECIALLY WITH THE HELP OF
THE AFOREMENTIONED WAVE.
AS FOR HEAVY RAIN CHANCES...THE BEST SHOT WOULD BE JUST
NORTH OF THE SYNOPTIC FRONT TO THE SOUTH OF THE CWA. IT ONCE LOOKED
LIKE SOME ELEVATED CONVECTION COULD GET GOING AND PRODUCE SOME
TRAINING CELLS WITH INCREASED MOISTURE TRANSPORT ALONG WITH A LOT OF
HELP FROM THE LEFT FRONT QUADRANT OF THE UPPER JET. HOWEVER...MODELS
ARE TRENDING SOUTH WITH THE JET AND FRONT...AND FLOODING POTENTIAL
SHOULD REMAIN MAINLY SOUTH OF THE CWA...WITH ONLY PERHAPS A
POSSIBILITY OF VERY LOCALIZED FLOODING IN NORTH CENTRAL KANSAS.
BY MIDNIGHT...THE COLD FRONT IS EXPECTED TO AT LEAST BISECT THE
CWA...WITH AN END OF PRECIPITATION BEHIND THE COLD FRONT. BY
12Z...THIS FRONT SHOULD BE CLEAR OF THE CWA...AND TAKING THE
PRECIPITATION WITH IT. THE SEVERE THREAT SHOULD COMPLETELY DIMINISH
BY THIS TIME. DISTINCTLY DRIER AND COOLER AIR WILL MAKE ITS WAY
BEHIND THE FRONT FOR FRIDAY. LOOKS LIKE THERE SHOULD BE ENOUGH
SUBSIDENCE FROM PREVENTING ANY AFTERNOON SHOWER ACTIVITY FROM
POPPING UP...WITH ONLY SOME CUMULUS EXPECTED DURING FRIDAY
AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM CDT THU JUL 25 2013
PRIMARY FORECAST CONCERN THROUGH THE LONG TERM PERIOD LIES WITH
PRECIPITATION CHANCES.
THE START OF THE LONG TERM PERIOD FRIDAY EVENING SHOWS MODELS NOT IN
TOO BAD OF AGREEMENT...WITH UPPER LEVEL NORTHWESTERLY FLOW SET UP
ACROSS THE CENTRAL PLAINS...SITTING BETWEEN LOW PRESSURE OVER THE
WRN GREAT LAKES AND A RIDGE OF HIGH PRESSURE OVER THE DESERT
SW/ROCKIES. WHILE THE FORECAST THROUGH THE EVENING HOURS REMAINS
DRY...ADDITIONAL THUNDERSTORM CHANCES RETURN TO THE CWA LATER THAT
NIGHT...AS A SHORTWAVE PIECE OF ENERGY ASSOCIATED WITH THAT GREAT
LAKES LOW STARTS SLIDING SOUTH THROUGH THE DAKOTAS AND EVENTUALLY
THE CENTRAL PLAINS. MODELS ALSO IN PRETTY GOOD AGREEMENT SHOWING AN
UPPER LEVEL JET STREAK SLIDING INTO THE AREA...AND THE POSSIBILITY
FOR AT LEAST A FEW SHOWERS/TSTORMS WILL BE THERE. DURING THE
DAYTIME HOURS ON SATURDAY...FEW MORE VARIATIONS SHOW UP BETWEEN
MODELS WITH PRECIPITATION CHANCES...WHILE THE WAVE IS MOVING
OUT...AN UPPER LEVEL JET STREAK LINGERS IN THE AREA...SO KEPT POPS
GOING DURING THE MORNING HOURS. NOT OUT OF QUESTION SOME POPS DURING
THE AFTERNOON HOURS MAY BE NEEDED...DEPENDING ON HOW UPCOMING MODELS
TREND.
THROUGH THE REST OF THE WEEKEND...LOW PRESSURE REMAINS IN PLACE
ACROSS THE GREAT LAKES...BUT THAT WESTERN RIDGE LOOKS TO BE BEATEN
DOWN...AS ANOTHER LOW/ADDITIONAL PIECES OF ENERGY MOVE IN FROM WRN
CANADA AND THE PAC NW. THIS WILL RESULT IN MORE ZONAL/PROGRESSIVE
FLOW...GIVING THE CWA BETTER PRECIP CHANCES FROM PASSING
DISTURBANCES. THE PERIODIC CHANCES CONTINUE THROUGH SUNDAY...AND
SUNDAY NIGHTS CHANCES ARE AIDED BY INCREASED LIFT VIA A STRONGER
SRLY LLJ NOSING INTO THE REGION...THUS THE CONTINUED HIGHER POPS.
LOOKING AT THE EARLY/MID WORK WEEK...THAT SAME ZONAL FLOW REMAINS IN
PLACE...AND SO DOES THE PERIODIC PASSAGES OF SHORTWAVE DISTURBANCES
AND PRECIPITATION CHANCES. THERE ARE POPS IN JUST ABOUT EVERY
PERIOD...BUT CERTAINLY NOT LOOKING AT A MULTI-DAY RAIN OUT...JUST
DIFFICULT AT THIS POINT IN TIME TO PINPOINT SPECIFIC TIMING/LOCATION
DETAILS DUE TO MODEL UNCERTAINTIES.
THROUGH THE MAJORITY OF THE FORECAST PERIOD...THERE IS BETTER
SUPPORT FROM MODELS SHOWING THE MAIN INSTABILITY AXIS ALONG/JUST TO
THE WEST OF THE CWA...AND OVERALL DEEP LAYER SHEAR IS ON THE LOWER
SIDE. CANT RULE OUT SOME STRONG TO SEVERE THUNDERSTORMS...BUT NOT
LOOKING AT ANY WIDESPREAD SEVERE WEATHER EVENTS.
AS FAR AS TEMPERATURES GO...CURRENT FORECAST HIGHS SAT THROUGH
THURSDAY ARE BELOW AVG TO NEAR AVG FOR THIS TIME OF YEAR. SAT
THROUGH MON HIGHS GENERALLY RANGE FROM THE MID 70S IN THE NEAST TO
LOWER/MID 80S IN THE SW...WHILE TUES THROUGH THURS ARE IN THE
80S...WITH SOME READINGS NEAR 90 POSSIBLE IN THE SOUTH. FORECAST
OVERNIGHT LOWS START OUT THE PERIOD IN THE 50S...BUT EVENTUALLY
CLIMB BACK INTO THE 60S BY THE START OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1236 AM CDT FRI JUL 26 2013
AS SKIES CONTINUE TO CLEAR OVER THE NEXT COUPLE HOURS WITH LIGHT
TO NO WINDS...EXPECT THE POTENTIAL FOR SOME MVFR VSBYS IN AREAS OF
FOG THAT AREA ABLE TO DEVELOP. DID NOT HIT THE FOG POTENTIAL
PARTICULARLY HARD AS RAINFALL TOTALS WERE LIGHT NEAR THE TERMINAL
TODAY...BUT IF FOG IS ABLE TO DEVELOP...COULD SEE IFR CIGS/VSBYS
BEFORE DAYBREAK. OTHERWISE...AS WINDS PICK UP OUT OF THE NORTH
AROUND 13Z...EXPECT ANY FOG THAT IS ABLE TO DEVELOP TO RAPIDLY
SCOUR OUT...WITH GUSTY WINDS TO 20KTS POSSIBLE AFT 15Z.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...SAR
SHORT TERM...HEINLEIN
LONG TERM...ADO
AVIATION...SAR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1122 PM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 1116 PM CDT THU JUL 25 2013
WENT AHEAD AND TRIMMED POPS A BIT ACROSS THE FORECAST AREA FOR THE
OVERNIGHT HOURS TO REFLECT CURRENT RADAR TRENDS AND SATELLITE
DATA. IN ADDITION...ADDED SOME PATCHY FOG TO SOUTHWESTERN PORTIONS
OF THE FORECAST AREA THAT RECEIVED SOME DECENT RAINFALL TODAY TO
COINCIDE WITH THINKING THAT AS SKIES CLEAR AND WINDS REMAIN
LIGHT...COULD SEE THE POTENTIAL FOR SOME FOG DEVELOPMENT...
ESPECIALLY ACROSS PORTIONS OF NORTH CENTRAL KANSAS. LATEST SREF
INDICATES THIS POTENTIAL AS DOES 02Z HRRR WHICH TAKES VISIBILITIES
DOWN TO 0.25 MILES IN SPOTS. OPTED NOT TO BE THIS
PESSIMISTIC...BUT WILL CONTINUE TO MONITOR POTENTIAL FOG
DEVELOPMENT AS WE GO THROUGH THE OVERNIGHT HOURS TO SEE IF THE
AREA AND DENSITY NEEDS TO BE EXPANDED OR NOT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM CDT THU JUL 25 2013
WATER VAPOR LOOPS REVEAL A POSITIVELY TILTED SHORTWAVE
TROUGH/PERTURBATION WITHIN NORTHWEST FLOW CROSSING NORTHWESTERN
NEBRASKA INTO COLORADO THIS AFTERNOON. AT THE SURFACE...SOME
SCATTERED SHOWER ACTIVITY IS OCCURRING ACROSS THE CWA AS A COMPLEX
SMALL SCALE SURFACE SCENARIO INCLUDING SOME OUTFLOW BOUNDARIES
EXISTS. THIS ACTIVITY IS OCCURRING BETWEEN TWO SYNOPTIC BOUNDARIES.
ONE IS A COLD FRONT TO THE NORTHWEST...LOCATED IN NORTHWESTERN
NEBRASKA...AND THE OTHER IS A STATIONARY FRONT...ONCE A WARM
FRONT...LOCATED IN CENTRAL KANSAS. THESE TWO FEATURES WILL BE FOCI
FOR THUNDERSTORM DEVELOPMENT LATER ON THIS AFTERNOON INTO THE
EVENING. SEVERE CHANCES ARE DICEY. SINCE MOST OF OUR CWA HAS BEEN IN
THE CLOUDS TODAY...THIS HAS KEPT INSTABILITY MORE AT
BAY...DECREASING THE LIKELIHOOD OF SEVERE WEATHER. SOME CONVECTION
HAS ALREADY BEGUN...WITH 1500 TO 2000 J/KG OF CAPE. SHEAR IS RATHER
MARGINAL FOR THE AFTERNOON...AND ACTUALLY DECREASES INTO THE EVENING
HOURS. THERE IS A FAIRLY SMALL WINDOW OF OPPORTUNITY FOR SEVERE
WEATHER TO DEVELOP AS THE WAVE TO THE NORTHWEST MOVES INTO THE
AREA...AND WITH THE SYNOPTIC FRONTS IN THE VICINITY. THE MAIN
SUPPORT FOR SEVERE THREAT...THE SHORTWAVE TROUGH AND
INSTABILITY...WILL DIMINISH BY 10 PM...AFTER SUNSET AND BEHIND THE
WAVE. IN SUMMARY...THE RISK FOR SEVERE WEATHER LOOKS DICEY IF NOT
MEAGER...BUT NOT OUT OF THE QUESTION....ESPECIALLY WITH THE HELP OF
THE AFOREMENTIONED WAVE.
AS FOR HEAVY RAIN CHANCES...THE BEST SHOT WOULD BE JUST
NORTH OF THE SYNOPTIC FRONT TO THE SOUTH OF THE CWA. IT ONCE LOOKED
LIKE SOME ELEVATED CONVECTION COULD GET GOING AND PRODUCE SOME
TRAINING CELLS WITH INCREASED MOISTURE TRANSPORT ALONG WITH A LOT OF
HELP FROM THE LEFT FRONT QUADRANT OF THE UPPER JET. HOWEVER...MODELS
ARE TRENDING SOUTH WITH THE JET AND FRONT...AND FLOODING POTENTIAL
SHOULD REMAIN MAINLY SOUTH OF THE CWA...WITH ONLY PERHAPS A
POSSIBILITY OF VERY LOCALIZED FLOODING IN NORTH CENTRAL KANSAS.
BY MIDNIGHT...THE COLD FRONT IS EXPECTED TO AT LEAST BISECT THE
CWA...WITH AN END OF PRECIPITATION BEHIND THE COLD FRONT. BY
12Z...THIS FRONT SHOULD BE CLEAR OF THE CWA...AND TAKING THE
PRECIPITATION WITH IT. THE SEVERE THREAT SHOULD COMPLETELY DIMINISH
BY THIS TIME. DISTINCTLY DRIER AND COOLER AIR WILL MAKE ITS WAY
BEHIND THE FRONT FOR FRIDAY. LOOKS LIKE THERE SHOULD BE ENOUGH
SUBSIDENCE FROM PREVENTING ANY AFTERNOON SHOWER ACTIVITY FROM
POPPING UP...WITH ONLY SOME CUMULUS EXPECTED DURING FRIDAY
AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM CDT THU JUL 25 2013
PRIMARY FORECAST CONCERN THROUGH THE LONG TERM PERIOD LIES WITH
PRECIPITATION CHANCES.
THE START OF THE LONG TERM PERIOD FRIDAY EVENING SHOWS MODELS NOT IN
TOO BAD OF AGREEMENT...WITH UPPER LEVEL NORTHWESTERLY FLOW SET UP
ACROSS THE CENTRAL PLAINS...SITTING BETWEEN LOW PRESSURE OVER THE
WRN GREAT LAKES AND A RIDGE OF HIGH PRESSURE OVER THE DESERT
SW/ROCKIES. WHILE THE FORECAST THROUGH THE EVENING HOURS REMAINS
DRY...ADDITIONAL THUNDERSTORM CHANCES RETURN TO THE CWA LATER THAT
NIGHT...AS A SHORTWAVE PIECE OF ENERGY ASSOCIATED WITH THAT GREAT
LAKES LOW STARTS SLIDING SOUTH THROUGH THE DAKOTAS AND EVENTUALLY
THE CENTRAL PLAINS. MODELS ALSO IN PRETTY GOOD AGREEMENT SHOWING AN
UPPER LEVEL JET STREAK SLIDING INTO THE AREA...AND THE POSSIBILITY
FOR AT LEAST A FEW SHOWERS/TSTORMS WILL BE THERE. DURING THE
DAYTIME HOURS ON SATURDAY...FEW MORE VARIATIONS SHOW UP BETWEEN
MODELS WITH PRECIPITATION CHANCES...WHILE THE WAVE IS MOVING
OUT...AN UPPER LEVEL JET STREAK LINGERS IN THE AREA...SO KEPT POPS
GOING DURING THE MORNING HOURS. NOT OUT OF QUESTION SOME POPS DURING
THE AFTERNOON HOURS MAY BE NEEDED...DEPENDING ON HOW UPCOMING MODELS
TREND.
THROUGH THE REST OF THE WEEKEND...LOW PRESSURE REMAINS IN PLACE
ACROSS THE GREAT LAKES...BUT THAT WESTERN RIDGE LOOKS TO BE BEATEN
DOWN...AS ANOTHER LOW/ADDITIONAL PIECES OF ENERGY MOVE IN FROM WRN
CANADA AND THE PAC NW. THIS WILL RESULT IN MORE ZONAL/PROGRESSIVE
FLOW...GIVING THE CWA BETTER PRECIP CHANCES FROM PASSING
DISTURBANCES. THE PERIODIC CHANCES CONTINUE THROUGH SUNDAY...AND
SUNDAY NIGHTS CHANCES ARE AIDED BY INCREASED LIFT VIA A STRONGER
SRLY LLJ NOSING INTO THE REGION...THUS THE CONTINUED HIGHER POPS.
LOOKING AT THE EARLY/MID WORK WEEK...THAT SAME ZONAL FLOW REMAINS IN
PLACE...AND SO DOES THE PERIODIC PASSAGES OF SHORTWAVE DISTURBANCES
AND PRECIPITATION CHANCES. THERE ARE POPS IN JUST ABOUT EVERY
PERIOD...BUT CERTAINLY NOT LOOKING AT A MULTI-DAY RAIN OUT...JUST
DIFFICULT AT THIS POINT IN TIME TO PINPOINT SPECIFIC TIMING/LOCATION
DETAILS DUE TO MODEL UNCERTAINTIES.
THROUGH THE MAJORITY OF THE FORECAST PERIOD...THERE IS BETTER
SUPPORT FROM MODELS SHOWING THE MAIN INSTABILITY AXIS ALONG/JUST TO
THE WEST OF THE CWA...AND OVERALL DEEP LAYER SHEAR IS ON THE LOWER
SIDE. CANT RULE OUT SOME STRONG TO SEVERE THUNDERSTORMS...BUT NOT
LOOKING AT ANY WIDESPREAD SEVERE WEATHER EVENTS.
AS FAR AS TEMPERATURES GO...CURRENT FORECAST HIGHS SAT THROUGH
THURSDAY ARE BELOW AVG TO NEAR AVG FOR THIS TIME OF YEAR. SAT
THROUGH MON HIGHS GENERALLY RANGE FROM THE MID 70S IN THE NEAST TO
LOWER/MID 80S IN THE SW...WHILE TUES THROUGH THURS ARE IN THE
80S...WITH SOME READINGS NEAR 90 POSSIBLE IN THE SOUTH. FORECAST
OVERNIGHT LOWS START OUT THE PERIOD IN THE 50S...BUT EVENTUALLY
CLIMB BACK INTO THE 60S BY THE START OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 554 PM CDT THU JUL 25 2013
VFR CONDITIONS FORECAST THROUGH THE NEXT 24 HOURS.
SHOWER AND THUNDERSTORM ACTIVITY COULD IMPACT GRI THROUGH 06Z AND
SHOULD SUCH ACTIVITY BE REALIZED AT GRI...THEN VISIBILITY
RESTRICTION COULD ALSO BE REALIZED IN RA. FOR NOW HOWEVER...WILL
GO WITH VCTS THROUGH 06Z...WITH NO VISIBILITY RESTRICTION...AND
UPDATE THE TAF AS NECESSARY. THE SURFACE WIND WILL REMAIN FROM THE
SOUTH AT AROUND 12KTS TO START THE TAF PERIOD...BECOMING LIGHT AND
VARIABLE BY 06Z...THEN BECOMING MORE ESTABLISHED FROM THE NORTH AT
AROUND 15KTS DURING THE DAY FRIDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...SAR
SHORT TERM...HEINLEIN
LONG TERM...ADO
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1124 PM MDT THU JUL 25 2013
.AVIATION...
06Z TAF CYCLE
THUNDERSTORMS ARE SCATTERED OVER THE UPPER RIO GRANDE VALLEY AND
INTO THE SOUTHERN SANGRE DE CRISTO AND CENTRAL MOUNTAINS WITH
ANOTHER LINE OF STORMS IN THE EAST CENTRAL PLAINS OF NEW MEXICO.
OUTFLOW BOUNDARIES FROM CURRENT ACTIVITY WILL LIKELY SPAWN
ADDITIONAL CELLS OVER CENTRAL AND NORTH CENTRAL NEW MEXICO INTO
THE EARLY MORNING HOURS. THE TYPICAL HAZARDS WILL ACCOMPANY STORM
DOWNPOURS...INCLUDING REDUCED VISIBILITY AND CEILINGS ALONG WITH
LOCALIZED GUSTY OUTFLOW WINDS. STORMS WILL GENERALLY DRIFT SOUTH
SOUTHEAST...IMPACTING THE EAST CENTRAL TO SOUTHEASTERN PLAINS
BEFORE SUNRISE. STORMS WILL REDEVELOP ON FRIDAY AFTERNOON OVER A
LARGE MAJORITY OF THE FORECAST AREA.
52
.PREV DISCUSSION...321 PM MDT THU JUL 25 2013...
ENHANCED NW TO SE STEERING FLOW IN PLACE ACROSS ROUGHLY
THE NE HALF OF THE FORECAST AREA TODAY RESULTING IN MUCH FASTER
STORM MOTIONS BUT ALSO GREATER STORM ORGANIZATION/STRUCTURE. THE
SW HALF CONTINUES UNDER THE INFLUENCE OF AN UPPER LEVEL COL REGION
BETWEEN TWO HIGH CENTERS...PRIMARY ONE OVER NW AZ AND A SECONDARY
CENTROID WEST OF THE TX BIG BEND REGION. AT LEAST TWO WELL-
DEFINED MESOSCALE CONVECTIVE VORTICES IN THE VICINITY OF OUR
SOUTHERN BORDER REGION BUT HOW THEY WILL MANIFEST THEMSELVES WITHIN
THE NEXT FEW HOURS AS DAYTIME HEATING/INSTABILITY PEAK IS UNCLEAR.
REGION OF VERY FAVORABLE 300-400 MB DEFORMATION IS DEFINITELY
CONTRIBUTING TO AN ACTIVE CROP OVER THE WEST AND A BIT FARTHER
NORTH THAN WHAT MODELS SUGGESTED.
WILL CONTINUE TO FOCUS THE BEST POPS ACROSS THE NC/NE AND
EVENTUALLY EC ZONES AS WELL AS THE WCC/SW. SHORT- WAVE TROUGH
BRUSHING NORTHEAST NEW MEXICO THROUGH THE REMAINDER OF THE
AFTERNOON WILL CONTINUE TO BOOST STORM COVERAGE/INTENSITY THERE
WITH A FEW STRONG/SEVERE STORMS A GOOD BET. SEWD-MOVING AND
GRADUALLY EXPANDING/DEEPENING COLD POOLS WILL LIKELY TOUCH OFF NEW
CONVECTION FARTHER SOUTH...AND THE LATEST HRRR STRONG SUGGESTS A
LARGER CONVECTIVE COMPLEX TAKING SHAPE ACROSS PARTS OF EC PLAINS.
EARLIER EXPANSION OF THE FLASH FLOOD WATCH NOT LOOKING GREAT THUS
FAR...BUT WILL LET RIDE FOR EVENING CREW TO REEVALUATE.
IN WAKE OF THE SUBTLE SHORT-WAVE FEATURE THIS AFTERNOON/EARLY
EVENING... MODELS ADVERTISE A NEW BACKDOOR FRONTAL BOUNDARY TO
SLOWLY MAKE ITS WAY SOUTH AND EVENTUALLY WEST DURING THE DAY
FRIDAY. SOMEWHAT DRIER/MORE STABLE AIR MASS EXPECTED TO LIMIT
CONVECTION ACROSS MUCH OF THE NE/EC PLAINS THOUGH LOW LEVEL UPSLOPE
SHOULD PROVE BENEFICIAL FOR THE EAST SLOPES OF THE SANGRES.
OTHERWISE...UPPER HIGH CENTERED TO OUR NORTHWEST SLOWLY BUILDS OUR
DIRECTION. THOUGH NOT AS ROBUST AS TODAY...A NW TO SE STEERING
FLOW WILL CONTINUE FAVOR THE HIGH PLAINS ON FRIDAY WITH THE
COMBINATION OF DEEPER MOISTURE/VERY WEAK STEERING FLOW FAVORING
THE WC/SW ZONES FOR PERSISTENT FLASH FLOOD THREAT.
THE UPPER HIGH WILL CONTINUE TO PRESS SOUTHWARD INTO THE WEEKEND
AND ESPECIALLY EARLY NEXT WEEK WITH A MARKED TREND TOWARD A DRIER
CONDITIONS BENEATH ENHANCED WEST TO EAST FLOW REGIME. IN OTHER
WORDS THE WESTERLIES LOOK TO RETURN AND STRONGLY SO ACROSS
NORTHERN AREAS OF THE STATE DURING THE EXTENDED.
.FIRE WEATHER...
A FAIRLY DYNAMIC DAY ON TAP AS A SHORTWAVE CAUGHT IN NORTHWEST FLOW
MOVES OVER THE CENTRAL AND SOUTHERN ROCKIES. STORMS HAVE FIRED UP
AHEAD OF THIS SHORTWAVE ACROSS NORTH CENTRAL AND NORTHEAST AREAS.
RESIDUAL MONSOONAL MOISTURE CAUGHT WITHIN A DEFORMATION ZONE OR
LIFTING ZONE IS FOUND ELSEWHERE. STORMS ARE GRADUALLY FIRING UP
WITHIN THIS ZONE. EXPECTING ANOTHER ACTIVE THUNDERSTORM DAY LASTING
THROUGH THE EVENING HOURS.
MODELS HAVE BEEN SHOWING SOME DRYING ACROSS THE NORTHWEST THIRD ON
FRIDAY. A BACK DOOR COLD FRONT WHICH WILL HAVE PUSHED INTO THE
EASTERN PLAINS TONIGHT FOLLOWING THE DISTURBANCE OR SHORTWAVE
PASSAGE WILL PROVIDE THE MAIN FOCUS FOR STORMS DURING THE AFTERNOON
AND EVENING FRIDAY. AS OF RIGHT NOW...THE MAIN FOCUS AREA WILL BE
FOUND ACROSS ZONE 109 EXTENDING NORTHEASTWARD TO THE SANGRE DE
CRISTOS. A MORE STABLE AIRMASS STILL LOOKS TO BE A LIMITER FOR
WETTING THUNDERSTORMS ACROSS THE FAR EASTERN PLAINS DURING THE
AFTERNOON HOURS. OVERALL...COVERAGE LOOKS TO BE SLIGHTLY LESS WITH
SLIGHTLY LESS HUMIDITY VERSUS TODAY.
MODELS ARE CONVERGING ON PLACING THE UPPER HIGH CENTER OVER FAR
SOUTHERN NM AND NORTHERN MEXICO ON SATURDAY. THE STEERING FLOW FOR THE
STORMS WOULD TURN MORE WEST TO EAST AS A RESULT. MOISTURE IS STILL
PLENTIFUL ACROSS ARIZONA SO THIS COULD ACTUALLY RESULT IN AN UPTICK
IN SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON/EVENING. THIS
INCLUDES THE ENTIRE EASTERN PLAINS DUE TO STEERING FLOW
CONSIDERATIONS. WETTING RAIN AND ABUNDANT CLOUD COVER WITH AN UPTICK
IN HUMIDITY IS A PRETTY GOOD BET.
THE CENTER OF THE UPPER HIGH SHOULD REMAIN OVER NORTHERN MEXICO ON
SUNDAY. BY THIS POINT...A FAIRLY STRONG SURFACE LOW FOR THIS TIME OF
YEAR IS EXPECTED TO DEVELOP TO THE LEE OF THE CENTRAL MOUNTAINS AND
THE WESTERLY FLOW ALOFT SHOULD ALSO INCREASE SOME. MODELS VARY
SOMEWHAT ON THE STRENGTH BUT THEY STILL POINT TOWARDS A DRIER
WESTERLY FLOW. BY THIS POINT...ARIZONA IS EXPECTED TO SEE A DOWNTURN
IN MOISTURE VALUES THUS DRIER AIR SHOULD EVENTUALLY ENTRAIN ACROSS
NEW MEXICO AS A RESULT. THIS WILL NOT TOTALLY ELIMINATE THUNDERSTORM
DEVELOPMENT BUT WOULD REDUCE THE COVERAGE AND WETTING RAIN FOOTPRINT
SOME. THE GFS AND ECMWF MODELS PAINT THE MAIN FOCUS AREA FOR WETTING
RAIN ACROSS THE NORTHERN TIER OF THE STATE AND SPECIALLY ACROSS
NORTH CENTRAL AND NORTHEAST AREAS. DID BUMP UP WIND SPEEDS WHICH
LOOK MORE LIKE MID JUNE SO WILL CONTINUE TO MONITOR THIS SCENARIO.
THE LATEST GFS AND ECMWF PAINT A FURTHER REDUCTION IN SHOWER AND
THUNDERSTORM COVERAGE ON MONDAY AS DRIER AIR INFILTRATES THE STATE
FROM THE WEST. MODELS ARE VERY BULLISH ON PAINTING VERY LITTLE
CONVECTION SO WILL BE INTERESTING TO SEE WHAT TURNS OUT. EITHER
WAY...EXPECTING DRIER AND WARMER CONDITIONS EARLY NEXT WEEK. AS THE
WEEK PROGRESSES...EXPECTING SOME SORT OF MOISTURE SEEPAGE AS THE
UPPER HIGH TRIES TO BUILD NORTHWARD AND PERHAPS EASTWARD. THE SEEPAGE WOULD
MOST LIKELY COME ALONG THE CONTINENTAL DIVIDE AS WELL AS VIA A WIND
SHIFT ACROSS THE NORTHEAST. EITHER WAY...WETTING THUNDERSTORMS LOOK
TO BE MORE ON THE MINIMAL KIND THROUGH THE EARLIER HALF OF NEXT
WEEK. PERHAPS INCREASING A BIT MORE THE LATTER HALF OF NEXT WEEK IF
THE HIGH SHIFTS OVER TEXAS. SOME OF THE MODELS ARE SHOWING THIS
TREND. IT SHOULD BE POINTED OUT THAT A 3 TO 4 DAY DOWNTREND IN
WETTING THUNDERSTORMS TYPICALLY OCCURS DURING THE MONSOON MOST YEARS
SO NOTHING TOO OUT OF THE ORDINARY BUT WILL KEEP AN EYE ON
SIGNIFICANT TRENDS...WHETHER THEY BE MOISTENING OR DRYING AS WE GO
FORWARD.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
513 AM EDT FRI JUL 26 2013
.SYNOPSIS...
A COASTAL LOW WILL PASS NEAR CAPE COD THIS MORNING AND THEN HEAD
INTO THE GULF OF MAINE BY THIS EVENING. THIS SYSTEM WILL BRING
CLOUDS TO VERMONT ALONG WITH A CHANCE OF SHOWERS TO EASTERN PORTIONS
OF THE STATE. ELSEWHERE...DRY WEATHER WITH SOME SUNSHINE IS
EXPECTED. WEAK HIGH PRESSURE WILL PREVAIL TONIGHT INTO SATURDAY. A
STRONG LOW PRESSURE SYSTEM AND ASSOCIATED FRONT WILL BRING SHOWERS
WITH EMBEDDED STORMS ON SUNDAY. TEMPERATURES WILL BE SLIGHTLY BELOW
NORMAL TODAY...AND A BIT ABOVE NORMAL ON SATURDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 508 AM EDT FRIDAY...UPPER LOW OVER MID ATLANTIC STATES WILL
BE LIFTING NORTHEASTWARD TODAY WHILE ASSOCIATED SURFACE LOW
TRACKS FROM SOUTH OF CAPE COD THIS MORNING INTO GULF OF MAINE BY
THIS EVENING. CLOUDS ASSOCIATED WITH THIS SYSTEM HAVE SPREAD NORTHWEST
ACROSS VERMONT...WITH SOME CIRRUS EVEN MAKING IT BACK INTO PARTS
OF NORTHERN NEW YORK. BULK OF PRECIPITATION ASSOCIATED WITH THIS
DISTURBANCE IS STILL EXPECTED TO REMAIN EAST OF FORECAST
AREA...BUT A PERIOD OF LIGHT RAIN OR SHOWERS IS POSSIBLE EAST OF
THE GREEN MOUNTAINS DURING THE DAY TODAY. ACROSS THE REST OF THE
FORECAST AREA IT WILL REMAIN DRY...WITH PLENTY OF SUNSHINE
EXPECTED ACROSS NORTHERN NEW YORK. PROGGED 85H TEMPS WARM 2 TO 3C
FROM THURSDAY...SUPPORTING MAX TEMPS IN THE UPPER 70S TO NEAR 80
IN THE CHAMPLAIN AND SAINT LAWRENCE VALLEYS.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH SUNDAY/...
AS OF 508 AM EDT FRIDAY...THE COASTAL LOW DEPARTS TONIGHT...LEAVING
THE NORTH COUNTRY WITH DRY CONDITIONS AND CLEAR TO PARTLY CLOUDY
SKIES. DRY CONDITIONS EXPECTED TO CONTINUE THROUGH MOST OF
SATURDAY ACROSS THE REGION...ALTHOUGH THERE IS A SLIGHT CHANCE FOR
A FEW SHOWERS LATER IN THE AFTERNOON OVER WESTERN PORTIONS OF THE
FORECAST AREA. THIS IS DUE TO AN APPROACHING LOW PRESSURE SYSTEM
AND ASSOCIATED FRONTAL SYSTEM FROM THE GREAT LAKES. MIN TEMPS
TONIGHT WILL RANGE FROM THE UPPER 40S TO THE MID 50S ACROSS MOST
OF THE AREA...WITH SOME LOWER READINGS IN THE ADIRONDACKS.
TEMPERATURES SATURDAY WILL WARM INTO THE LOWER TO MID 80S IN THE
VALLEYS.
CHANCES FOR PRECIPITATION WILL INCREASE FROM WEST TO EAST ACROSS THE
FORECAST AREA SATURDAY NIGHT AND ESPECIALLY ON SUNDAY. THIS DUE TO
A DEEP CLOSED AND NEARLY VERTICALLY STACKED LOW PRESSURE SYSTEM AND
ASSOCIATED COLD/OCCLUDED FRONT...WHICH WILL MOVE ACROSS THE EASTERN
GREAT LAKES SATURDAY NIGHT AND INTO THE NORTH COUNTRY ON SUNDAY.
GOOD INFLUX OF MOISTURE INTO THE REGION IN ADVANCE OF THIS SYSTEM
WITH PRECIPITABLE WATER VALUES CLIMBING TO AROUND 1.75 INCHES
SUNDAY...SUPPORTING POSSIBILITY OF SOME HEAVIER SHOWERS. SOME
EMBEDDED THUNDER ALSO POSSIBLE WITH SOME INSTABILITY...ALBEIT
RATHER WEAK...INDICATED FOR SUNDAY. HAVE CONTINUED WITH LIKELY TO
CATEGORICAL POPS AND SLIGHT CHANCE THUNDER. RAINFALL AMOUNTS BY
SUNDAY EVENING MAY REACH AN INCH IN SOME AREAS. MAX TEMPS SUNDAY
WILL BE MAINLY IN THE 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 508 AM EDT FRIDAY...ANOTHER DAY WITH VERY LITTLE CHANGE IN THE
FORECAST FOR THE EXTENDED PERIOD AS MEDIUM/LONG RANGE SOLUTIONS
REMAIN LOCKED INTO THE TRACK AND STRENGTH OF THE OVERALL SYNOPTIC
SCALE FEATURES...WITH JUST A FEW DIFFERENCES IN TIMING FROM
YESTERDAYS RUNS.
WIDELY ADVERTISED DEEP CLOSED MID/UPPER LEVEL CIRCULATION AND
SURFACE COLD FRONT REMAIN JUST TO THE WEST OF THE BTV CWA STARTING
SUNDAY NIGHT...AND WILL SHIFT THROUGH THE NORTH COUNTRY THROUGH THE
DAY MONDAY. FAIRLY WIDESPREAD RAINFALL CONTINUES TO MOVE EASTWARD
ACROSS THE REGION SUNDAY NIGHT INTO MONDAY MORNING...BUT SHOULD
TAPER OFF BY MONDAY AFTERNOON AS THE SURFACE FRONT PUSHES THROUGH
AND A SIGNIFICANT DRY SLOT MOVES OVER THE AREA. DRY CONDITIONS THEN
CONTINUE FOR MONDAY NIGHT INTO TUESDAY MORNING...WITH A CHANCE FOR
SOME DIURNALLY DRIVEN SHOWERS TUESDAY AFTERNOON AS THE UPPER FLOW
TURNS NORTHWEST AND LOW LEVEL LAPSE RATES STEEPEN.
LOOKING AT FAIRLY DRY CONDITIONS FOR TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT AS UPPER LEVEL LOW PRESSURE EXITS THE NORTHEAST AND ZONAL FLOW
TO SLIGHT RIDGING DEVELOPS ALOFT. THIS IS IN RESPONSE TO A
DEVELOPING UPPER TROUGH AND POTENT SHORTWAVE ENERGY DIGGING
SOUTHWARD INTO THE GREAT LAKES...WHICH LOOKS TO BRING OUR NEXT
CHANCE FOR SHOWERS/STORMS THURSDAY AND THURSDAY NIGHT. OVERALL
SYNOPTIC SETUP LOOKS VERY SIMILAR TO WHAT WE`RE EXPECTING THIS
COMING SUNDAY (7/28)...SO KEEP A WATCHFUL EYE ON THAT SYSTEM AS WE
COULD BE IN FOR A REPEAT PERFORMANCE LATER NEXT WEEK. STAY TUNED.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...VFR CONDITIONS WILL PREVAIL THROUGH THE
PERIOD WITH EXCEPTION OF OVERNIGHT FOG AT KSLK. CURRENT SATELLITE
IMAGERY SHOWS BKN-OVC MID/HIGH CLOUDS ACROSS ALL OVER VERMONT AND
INTO THE CHAMPLAIN VALLEY OF NEW YORK...WITH CLEAR SKIES WESTWARD.
TRENDS SHOW THIS WILL BE THE RULE FOR THE REMAINDER OF THE NIGHT
AS WELL...WITH CLEAR SKIES AND LIGHT WINDS LEADING TO SOME
POSSIBLE FOG DEVELOPMENT AT KSLK. LATEST RAP ANALYSIS SHOWS SOME
MODEST WINDS STILL REMAIN THOUGH IN THE BOUNDARY LAYER WHICH MAY
INHIBIT FOG MUCH LIKE LAST NIGHT...AND RELIABLE LAV GUIDANCE
CONTINUES TO BACK OFF ON FOG PROBS AS WELL. WON`T RULE IT
OUT...BUT HAVE JUST TEMPO`D SOME IFR INSTEAD OF GOING WITH
PREVAILING. ANY FOG BURNS OFF AFTER 11-12Z AND MID/HIGH CLOUDS
ACROSS VT GENERALLY SHIFT EAST OUT OF THE AREA BY 00Z. BEYOND
00Z...EXPECT JUST A FEW HIGH CLOUDS IN ADVANCE OF AN APPROACHING
SYSTEM FROM THE WEST WITH LIGHT WINDS. COULD SEE SOME FOG
AROUND...BUT LIKELY NOT UNTIL AFTER 06Z.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...
06Z SATURDAY THROUGH 06Z SUNDAY...VFR UNDER HIGH PRESSURE.
06Z SUNDAY THROUGH 12Z MONDAY...MAINLY VFR WITH PERIODS OF MVFR/IFR
LIKELY IN SHOWERS AND POSSIBLE TSRA WITH COLD FRONT PASSAGE.
12Z MONDAY THROUGH TUESDAY...MAINLY VFR WITH THE CHANCE FOR MVFR
RAIN SHOWERS EACH AFTERNOON AS UPPER LEVEL LOW PRESSURE SHIFTS
EAST THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RJS
NEAR TERM...RJS
SHORT TERM...RJS
LONG TERM...LAHIFF
AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
147 AM EDT FRI JUL 26 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE ACROSS THE NORTH COUNTRY THROUGH
FRIDAY...AS LOW PRESSURE MOVES TOWARD CAPE COD. THIS WILL INCREASE
CLOUDS ACROSS PARTS OF OUR REGION...WITH A CHANCE OF SHOWERS
POSSIBLE FOR EASTERN VERMONT THROUGH FRIDAY. A STRONGER SYSTEM AND
ASSOCIATED FRONT WILL PRODUCE A PERIOD OF SHOWERS WITH EMBEDDED
STORMS ON SUNDAY. TEMPERATURES WILL BE SLIGHTLY BELOW NORMAL
THROUGH FRIDAY...BEFORE RETURNING CLOSE TO NORMAL OVER THE
WEEKEND...WITH SOME INCREASE IN HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1228 AM EDT FRIDAY...GOING FORECAST LOOKING OKAY...SO ONLY
A FEW MINOR ADJUSTMENTS MADE TO HOURLY PARAMETERS TO REFLECT
LATEST DATA AND EXPECTED CONDITIONS FOR THE NEXT FEW HOURS. CLOUD
LINE SHOULD REMAIN ABOUT WHERE IT IS...WITH CLEAR SKIES ACROSS
MOST OF NORTHERN NEW YORK AND MAINLY CLOUDY IN VERMONT. ANY LIGHT
SHOWERS WILL BE CONFINED TO EASTERNMOST VERMONT. TEMPS NOT FALLING
MUCH ACROSS VERMONT DUE CLOUD COVER...BUT WILL CONTINUE TO DROP
ACROSS NORTHERN NEW YORK...WITH A FEW UPPER 30S IN THE
ADIRONDACKS.
PREVIOUS DISCUSSION...
MADE SOME SLIGHT ADJUSTMENTS TO SKY COVER AND TO MINIMUM
TEMPERATURES AND DEWPOINTS THROUGH TONIGHT INTO TOMORROW MORNING
PER LATEST OBSERVATIONAL TRENDS. SFC DEWPOINTS HAVE CREPT UP
STEADILY THIS EVENING ACROSS VT...AND NOW ARE RUNNING WELL INTO
THE 50S UNDER INCREASING MID TO HIGH LEVEL OVERCAST. AS A
RESULT...HAD TO MAKE SOME SLIGHT UPWARD ADJUSTMENTS TO OUR MINIMUM
TEMPERATURES IN THESE AREAS ACCORDINGLY. LEFT LOWS GENERALLY ALONE
ACROSS OUR NRN NY COUNTIES WHERE CLEAR SKIES AND LOWER DEWPOINTS
SHOULD BE THE RULE. FRONTAL WAVE CONTINUES TO DEVELOP OFF THE
DELMARVA COAST ALONG THE NORTH WALL OF THE GULF STREAM AND
CONTINUES TO TRACK NNE THIS EVENING. LATEST RAP/HRRR PROGS
MAINTAIN THEIR PRIOR IDEA OF KEEPING THE DEEPER MOISTURE AND
THREAT OF STEADIER PCPN WITH THIS SYSTEM JUST EAST OF THE FORECAST
AREA WITH PERHAPS SOME LIGHT ACTIVITY GRAZING OUR ERN VT COUNTIES
LATER TONIGHT INTO TOMORROW MORNING. CURRENT FORECAST HAS THIS
COVERED QUITE NICELY...SO NO CHANGES TO POPS IN THAT REGARD.
PATCHY FOG ALSO A GOOD BET ACROSS NRN NY WHERE LATEST PROGS
SUGGEST FAVORED AREAS WILL DROP BELOW CROSSOVER TEMPS AFTER 06Z.
HAVE A GREAT EVENING.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SATURDAY NIGHT/...
AS OF 410 PM EDT THURSDAY...PROGRESSIVE FLW ALOFT WL QUICKLY LIFT S/W
ENERGY AND DEEPER MOISTURE NORTHEAST ALONG THE EASTERN SEABOARD
ON FRIDAY. ONCE AGAIN ANTICIPATE A SHARP WEST TO EAST GRADIENT IN
RH FIELDS...WITH MAYBE A BRIEF SHOWER ACRS EXTREME EASTERN VT. WL
CONT TO MENTION SCHC POPS. PROGGED 85H TEMPS WARM ANOTHER 2 TO 3C
FROM THURS...TO SUPPORT NEAR NORMAL HIGHS IN THE 70S MTNS TO L/M
80S VALLEYS. WARMEST TEMPS WL BE ACRS THE SLV...WHERE SKIES WL BE
SUNNY.
FRIDAY NIGHT THRU SATURDAY NIGHT...DEEP CLOSED AND NEARLY VERTICAL
STACKED SYSTEM ACRS THE CENTRAL GREAT LAKES WL SLOWLY APPROACH THE
NE CONUS. THE MID/UPPER LVL FLW AHEAD OF THIS SYSTEM WL BECM
SOUTHERLY WITH SEVERAL EMBEDDED S/W`S...ESPECIALLY SAT AFTN/EVENING.
IN ADDITION...LATEST 12Z GFS SHOWS SEVERAL RIBBONS OF ENHANCED 850
TO 500MB RH ADVECTING FROM SOUTH TO NORTH ACRS OUR FA...IN THE
SOUTHERLY FLW ALOFT. HOWEVER...BEST LLVL SFC CONVERGENCE ASSOCIATED
WITH FRNT AND LOW PRES...ALONG WITH STRONGEST JET WINDS WL STAY WEST
OF OUR CWA THRU 12Z SUNDAY. INSTABILITY LOOKS LIMITED ON SAT ACRS
OUR CWA...AS NAM/GFS SHOW BEST PARAMETERS SOUTH OF OUR
FA...ASSOCIATED WITH HIGHER BL DWPTS. WL MENTION CHC POPS AFT 18Z
SATURDAY...ASSOCIATED WITH LOW/MID LVL WAA AND MOISTURE ADVECTION
ACRS OUR FA. QPF WL BE LIGHT WITH MAINLY SPRINKLES/VIRGA OCCURRING
INITIALLY. PROGGED 85H TEMPS BTWN 13 AND 15C...SUPPORT HIGHS BACK
INTO THE U70S MTNS TO M80S WARMER VALLEYS. IN ADDITION...HUMIDITY
LVLS WL CONT TO INCREASE...ESPECIALLY BY SAT NIGHT...ASSOCIATED WITH
SOUTHERLY FLW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 410 PM EDT THURSDAY...UPPER TROUGH OVER THE EASTERN GREAT
LAKES WILL BE SLOW TO MOVE EAST THROUGH THE FIRST HALF OF THE
EXTENDED PERIOD...SUNDAY THROUGH TUESDAY. AS A RESULT...DYNAMIC
SUPPORT WILL PLAY A FACTOR IN INCREASING PRECIPITATION CHANCES ON
SUNDAY WITH LIKELY TO CATEGORICAL PRECIPITATION CHANCES EXPECTED.
AFTER SUNDAY...THE AREA GETS IN THE DRY SLOT BEHIND THE COLD
FRONT...BUT STEEPENING LAPSE RATES DUE TO COLD AIR ADVECTION ALOFT
SUGGESTS THE POTENTIAL FOR DIURNALLY DRIVEN SHOWERS ON MONDAY AND
ESPECIALLY ON TUESDAY. WILL THEREFORE GO AHEAD AND ADD A CHANCE OF
SHOWERS TO MONDAY AND TUESDAY. WITH CLOUDS AND SHOWERS LINGERING
AROUND...LOOKING AT TEMPERATURES ABOUT 2 TO 4 DEGREES BELOW
NORMAL. WESTERLY FLOW DEVELOPS WEDNESDAY AND THURSDAY...SO DRIER
WEATHER IS EXPECTED ALONG WITH TEMPERATURES RIGHT AROUND SEASONAL
NORMALS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...VFR CONDITIONS WILL PREVAIL THROUGH THE
PERIOD WITH EXCEPTION OF OVERNIGHT FOG AT KSLK. CURRENT SATELLITE
IMAGERY SHOWS BKN-OVC MID/HIGH CLOUDS ACROSS ALL OVER VERMONT AND
INTO THE CHAMPLAIN VALLEY OF NEW YORK...WITH CLEAR SKIES WESTWARD.
TRENDS SHOW THIS WILL BE THE RULE FOR THE REMAINDER OF THE NIGHT
AS WELL...WITH CLEAR SKIES AND LIGHT WINDS LEADING TO SOME
POSSIBLE FOG DEVELOPMENT AT KSLK. LATEST RAP ANALYSIS SHOWS SOME
MODEST WINDS STILL REMAIN THOUGH IN THE BOUNDARY LAYER WHICH MAY
INHIBIT FOG MUCH LIKE LAST NIGHT...AND RELIABLE LAV GUIDANCE
CONTINUES TO BACK OFF ON FOG PROBS AS WELL. WON`T RULE IT
OUT...BUT HAVE JUST TEMPO`D SOME IFR INSTEAD OF GOING WITH
PREVAILING. ANY FOG BURNS OFF AFTER 11-12Z AND MID/HIGH CLOUDS
ACROSS VT GENERALLY SHIFT EAST OUT OF THE AREA BY 00Z. BEYOND
00Z...EXPECT JUST A FEW HIGH CLOUDS IN ADVANCE OF AN APPROACHING
SYSTEM FROM THE WEST WITH LIGHT WINDS. COULD SEE SOME FOG
AROUND...BUT LIKELY NOT UNTIL AFTER 06Z.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...
06Z SATURDAY THROUGH 06Z SUNDAY...VFR UNDER HIGH PRESSURE.
06Z SUNDAY THROUGH 12Z MONDAY...MAINLY VFR WITH PERIODS OF MVFR/IFR
LIKELY IN SHOWERS AND POSSIBLE TSRA WITH COLD FRONT PASSAGE.
12Z MONDAY THROUGH TUESDAY...MAINLY VFR WITH THE CHANCE FOR MVFR
RAIN SHOWERS EACH AFTERNOON AS UPPER LEVEL LOW PRESSURE SHIFTS
EAST THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...JMG/RJS
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1138 PM CDT THU JUL 25 2013
.UPDATE...
ISSUED AT 1137 PM CDT THU JUL 25 2013
MADE A FEW ADDITIONAL TWEAKS TO TIMING OF POPS AS SHOWERS ISOLATED
TO SCATTERED SHOWERS CONTINUE TO MOVE DOWN INTO THE NORTHEAST TO
NORTH CENTRAL CWA. DEW POINT VALUES HAVE BEEN HOLDING IN THE MID
TO LOW 50S. THERE WILL BE SOME DRIER AIR MOVING IN...BUT IT IS
STILL PRETTY FAR NORTH AND SO BUMPED UP LOWS IN THE NORTHWESTERN
COUNTIES A DEGREE OR SO.
UPDATE ISSUED AT 921 PM CDT THU JUL 25 2013
ADJUSTED POPS/WX FOR CURRENT TRENDS AND SHORT RANGE MODELS. MOST
OF THE PRECIP CONTINUES TO MOVE SLOWLY ACROSS SOUTHERN CANADA
UNDER THE MAIN UPPER LOW. THE PRIMARY VORT MAX WILL DIG DOWN INTO
THE CWA LATER ON TONIGHT...AND THE NAM AND HRRR CONTINUE TO SHOW
SOME DECENT PRECIP CHANCES FROM THE NORTHERN RED RIVER VALLEY
AND POINTS EASTWARD. THE RAP ON THE OTHER HAND...IS PRETTY SPARSE
WITH PRECIP OVER ALL BUT THE FAR EASTERN CWA AS MUCH OF THE
CANADIAN ACTIVITY DISSIPATES BEFORE MOVING SOUTH. WITH THE
STRENGTH OF THE UPPER SYSTEM WILL NOT PULL POPS COMPLETELY OVER
THE NORTHWESTERN CWA...BUT REDUCED THEM QUITE A BIT TO ISOLATED
SHOWERS PARTICULARLY FOR THE REST OF THE EVENING. ALSO CUT THE
SOUTHWARD EXTENT OF THE PRECIP UNTIL LATER TONIGHT. TEMPS STILL
SEEM ON TRACK TO BOTTOM OUT IN THE 50S. CURRENT FORECAST HAS SOME
UPPER 40S IN THE NORTHWEST WHICH FITS WITH GUIDENCE...BUT WILL
HAVE TO WATCH DEW POINTS AS THE DRIER AIR STILL SEEMS WELL NORTH
IN MANITOBA.
UPDATE ISSUED AT 642 PM CDT THU JUL 25 2013
SHOWERS AND THUNDERSTORMS HAVE DIMINISHED A BIT OVER THE NORTHERN
AND EASTERN CWA...BUT THERE IS STILL QUITE A BIT MORE ON RADAR UP
OVER CANADA ALONG WITH THE MAIN UPPER VORT LOBE. WILL KEEP THE
HIGH CHANCE POPS WE HAVE GOING FOR NOW AS ACTIVITY SHOULD INCREASE
AGAIN AS THE UPPER LOW DIGS INTO THE AREA. DID CHANGE THE WX TO
MENTION SHOWERS WITH ISOLATED THUNDER AS NOT MUCH LIGHTNING HAS
BEEN SEEN BEHIND THE COLD FRONT. MADE SOME MINOR TWEAKS TO CLOUDS
AND TEMPS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 305 PM CDT THU JUL 25 2013
MAIN CHALLENGE WILL BE SHOWER/TSTM CHANCES TONIGHT INTO EARLY
FRIDAY AND THEN TEMPS. MODELS RUNNING PRETTY CLOSE TO CONTINUITY
SO NO BIG FORECAST CHANGES EXPECTED.
QUITE A BIT OF CUMULUS FORMED AGAIN TODAY. ALSO SEEING POPCORN
SHOWERS/TSTMS ACROSS THE NORTH/NE. ONE STORM AROUND CLEARWATER
COUNTY IN MN WAS BRIEFLY SEVERE BUT HAS SINCE FADED. SEEING QUITE
A BIT OF UPSTREAM SHOWERS/ISOLATED THUNDER ACROSS SOUTHERN
MANITOBA ASSOCIATED WITH A NICE SHORT WAVE. THIS WAVE IS EXPECTED
TO ROTATE THRU THE FA TONIGHT SO SHOULD SEE STEADY OR EVEN
INCREASING SHOWERS AND TSTMS INTO THE EVENING. WITH THE STRENGTH
OF THE WAVE SOME MAY EVEN LAST WELL AFTER DARK. THE CUMULUS FIELD
SHOULD THIN OUT WITH LOSS OF HEATING BUT THERE ARE MORE MID AND
UPPER LEVEL CLOUDS ASSOCIATED WITH THE WAVE THAT WILL DROP THRU
TONIGHT WHICH WILL KEEP CLOUD AMOUNTS UP. THE GUSTY NORTHWEST
WINDS SHOULD DROP OFF SOME TONIGHT BUT WILL REMAIN STEADY
OVERNIGHT.
THE MAIN WAVE WILL MOVE SOUTH OF THE FA EARLY FRI BUT THERE WILL
STILL BE ANOTHER PIECE THAT WILL ROTATE THRU DURING THE DAY FRI.
500MB TEMPS ARE QUITE CHILLY WHICH SHOULD RESULT IN QUITE A BIT OF
CUMULUS FORMATION AGAIN AND MORE SPOTTY SHOWERS. SOME SHOWERS MAY
HANG AROUND INTO FRI AFTERNOON ESPECIALLY IN THE EAST. SFC HIGH
PRESSURE WILL DROP INTO CENTRAL ND FRI NIGHT WHICH SHOULD SET THE
STAGE FOR A COLD NIGHT THERE (NEAR RECORD LOWS).
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 305 PM CDT THU JUL 25 2013
SFC HIGH REMAINS IN CONTROL SAT INTO SUNDAY. POSITION OF THE HIGH
SAT NIGHT FAVORS COLDEST TEMPS IN THE EASTERN FA. NOT OUT OF THE
QUESTION FOR RECORD LOWS AGAIN.
FOR SUN NIGHT THROUGH WED AN UPPER RIDGE AND DRY AIRMASS WILL
KEEP THE EARLY PART OF THE PERIOD DRY...BUT THE RIDGE WILL MOVE
OFF TO THE EAST ON MONDAY AND THERE WILL BE INCREASING CHANCES OF
TSTMS MON AFTN INTO THE EVENING AS A WAVE MOVES ACROSS THE
NORTHERN TIER. ACTIVITY SHOULD CONTINUE INTO THROUGH THE DAY ON
TUESDAY AND IMPROVE BY EARLY WED MORNING. DAYTIME HIGHS NEXT WEEK
WILL CONTINUE TO BE BELOW SEASONAL NORMS...WITH MAX TEMPS
GENERALLY IN THE UPPER 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1137 PM CDT THU JUL 25 2013
MVFR CIGS HAVE ALREADY STARTED TO MOVE TOWARDS THE NORTHERN TAF
SITES. KGFK AND KTVF COULD ALSO SEE SOME SHOWERS LINGERING AROUND
EARLY IN THE PERIOD. THE BAND OF CIGS WILL CONTINUE TO MOVE SOUTH
OVERNIGHT. THERE SHOULD BE A BRIEF BREAK IN THE CLOUDS DURING THE
MORNING BEFORE CU REDEVELOPS AND CIGS OF AROUND 5000 FT RETURN.
NORTH WINDS WILL DIE OFF A BIT DURING THE EARLY MORNING HOURS
TONIGHT BUT THEN BECOME GUSTY AGAIN DURING THE DAY TOMORROW. SKIES
WILL CLEAR AND WINDS WILL DIE OFF AFTER SUNSET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...GODON
LONG TERM...GODON/SPEICHER
AVIATION...JR
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1140 PM CDT THU JUL 25 2013
.AVIATION...
A BIT OF A TRICKY FORECAST COMING UP FOR THE TERMINALS THIS
EVENING. ISSUE NUMBER ONE IS THE COLD FRONT PASSAGE TIMING. THE
SYNOPTIC SCALE MODELS AND THE HIGH RESOLUTION MESOSCALE MODELS
HAVE SLOWED DOWN THE APPROACH OF THE FRONT TO AFTER 00Z TOMORROW
EVENING. HAVE THEREFORE PUSHED THE TIMING OF THE COLD FRONT BACK A
FEW HOURS AND WILL BEGIN THE WINDS MOVING TO THE NORTHWEST AROUND
23Z...WITH THE STRONGEST WINDS INCREASING OUT OF THE NORTH BETWEEN
2 AND 3Z FOR THE METROPLEX TERMINALS. FOR WACO...HAVE FOLLOWED
SUIT FOR THE TIMING CHANGE...DELAYING BY 2 HOURS OR SO.
THE NEXT ISSUE IS THE POTENTIAL FOR CONVECTION DURING THE EARLY
MORNING HOURS. LATEST MESOSCALE MODELS ARE A LITTLE MORE
AGGRESSIVE IN KEEPING THE TEXAS PANHANDLE MCS GOING AND REACHING
THE METROPLEX BY 12-14Z. WHILE THIS REMAINS A POSSIBILITY...CONFIDENCE
IN THIS SCENARIO IS LOW ENOUGH TO INCLUDE A MENTION AT THIS POINT.
THE 03Z TAFS WILL HAVE A MUCH BETTER HANDLE ON THE PROGRESSION OF
THE SYSTEM.
FOX
&&
.UPDATE...
UPPER LEVEL SHORTWAVE TROUGH CURRENTLY IN THE HIGH PLAINS WILL
CONTINUE TO APPROACH NORTH TEXAS FROM THE NORTHWEST TONIGHT. AHEAD
OF THIS UPPER LEVEL ENERGY...SCATTERED SHOWERS AND STORMS HAVE
DEVELOPED ACROSS OKLAHOMA/KANSAS/NW TEXAS. SO FAR ACTIVITY HAS NOT
CONGEALED INTO AN ORGANIZED MCS...LIKELY DUE TO ANVIL LEVEL WINDS
BEING MUCH FASTER THAN INDIVIDUAL STORM MOTIONS. THIS MEANS
CONVECTION HAS A HARD TIME DEVELOPING A STRONG COLD POOL THAT
HELPS TO GENERATE ADDITIONAL CONVECTION AND EVENTUALLY AN
ORGANIZED MCS. MCS DEVELOPMENT IN THE ABSENCE OF STRONG FORCING
TENDS OCCUR MOST EASILY WHEN STRATIFORM/ANVIL PRECIPITATION TRAILS
CONVECTIVE CELL MOTIONS. SINCE STRONG ANVIL LEVEL FLOW WILL
PERSIST OVERNIGHT...EXPECT CONVECTIVE ACTIVITY TO REMAIN MORE
SCATTERED IN AREAS TO OUR NORTH AND NORTHWEST WITH THE CHANCE OF A
MCS BLASTING THROUGH THE REGION AT SUNRISE RATHER LOW. HOWEVER THE
UPPER LEVEL FORCING SHOULD BEGIN TO ARRIVE INTO THE NW ZONES LATE
TONIGHT AND WITH A SUFFICIENT AMOUNT OF ELEVATED INSTABILITY
AVAILABLE IN THE AREA...EXPECT SCATTERED ELEVATED CONVECTION TO
DEVELOP/MOVE INTO THE AREA FROM THE NORTHWEST. HAVE BUMPED UP POPS
TO CHANCE IN THE NW ZONES AND BROUGHT THE SLIGHT CHANCES FARTHER
TO THE SOUTHEAST TOWARD DAYBREAK. BEST UPPER LEVEL FORCING WILL
OVERSPREAD THE REGION DURING THE DAY ON FRIDAY AND POPS INCREASE
OVER THE AREA AFTER SUNRISE.
TR.92
&&
.PREV DISCUSSION... /ISSUED 350 PM CDT THU JUL 25 2013/
WEATHER CHANGES ARE ON THE WAY FOR NORTH AND CENTRAL TEXAS FRIDAY
THROUGH THE WEEKEND. A SHORTWAVE TROUGH CURRENTLY MOVING INTO THE
SOUTHERN PLAINS WILL CONTINUE MOVING SOUTHEAST FRIDAY AND IS
EXPECTED TO BE EAST OF THE REGION BY SATURDAY. AT THE SURFACE...A
LOW PRESSURE SYSTEM DEVELOPING IN THE PLAINS OF COLORADO WILL ALSO
MOVE SOUTHEAST REACHING NORTHWEST TEXAS FRIDAY MORNING. IN
ASSOCIATION WITH THE UPPER LEVEL TROUGH AND SURFACE LOW
PRESSURE...A COMPLEX OF THUNDERSTORMS IS EXPECTED TO DEVELOP NORTH
OF THE REGION THIS EVENING AND TONIGHT. A SECONDARY COMPLEX MAY
ALSO DEVELOP IN THE TEXAS PANHANDLE...POSSIBLY FROM CONVECTION
THAT IS CURRENTLY DEVELOPING IN THE LUBBOCK AREA. THE HRRR IS
SUGGESTING THE COMPLEX IN THE PANHANDLE WILL MOVE EAST REACHING
THE WESTERN COUNTIES OF OUR CWA LATE TONIGHT...BUT WEAKENING AS IT
APPROACHES THE WESTERN BORDER. HOWEVER...THE HRRR IS ALSO FARTHER
EAST WITH THE DEVELOPMENT OF THE COMPLEX THAN WHERE CURRENT
CONVECTION IS OCCURRING AROUND THE LUBBOCK AREA. WILL NEED TO
MONITOR TRENDS OUT WEST THROUGH THE EVENING HOURS FOR THE POTENTIAL
INCLUSION OF POPS IN OUR WESTERN COUNTIES OVERNIGHT.
THE MAIN COMPLEX OF STORMS IS EXPECTED TO TRAVEL EAST OR EAST-
SOUTHEAST ACROSS OKLAHOMA TONIGHT AND COULD GRAZE OUR NORTHERN
COUNTIES FRIDAY MORNING. HAVE KEPT LOW POPS NEAR THE RED RIVER
BEFORE DAYBREAK WITH INCREASING RAIN CHANCES AFTER DAYBREAK. THE
MODELS CONSISTENTLY KEEP THE MAJORITY OF THIS COMPLEX NORTH OF THE
RED RIVER...EXCEPT DIPPING ACROSS OUR NORTHERN AND NORTHEASTERN
COUNTIES DURING THE DAY ON FRIDAY. THE 4 KM WRF IS THE ONLY MODEL
EXPLICITLY SHOWING THE SOUTHERN EDGE OF THIS COMPLEX FARTHER
SOUTH...MOVING ALONG AND NORTH OF I-20 FRIDAY MORNING. HAVE
INCREASED POPS ALONG AND NORTH OF I-20 FRIDAY MORNING WITH LIKELY
POPS ALONG THE RED RIVER.
A COOL FRONT IS EXPECTED TO ACCOMPANY THE SURFACE LOW
PRESSURE...MOVING INTO NORTH TEXAS FRIDAY AFTERNOON. ADDITIONAL
BUT MORE SCATTERED RAIN ACTIVITY IS EXPECTED ALONG THE FRONT AND
HAVE INCREASED POPS ACROSS MOST OF THE CWA FOR FRIDAY AFTERNOON
AS THE FRONT MOVES INTO THE AREA. THE HIGHEST RAIN CHANCES
CONTINUE OVER THE NORTHEASTERN COUNTIES IN THE AFTERNOON HOURS.
THE RAIN ACTIVITY IS EXPECTED TO DIMINISH FRIDAY EVENING AS THE
FRONT MOVES FARTHER SOUTH OF INTERSTATE 20 BUT WILL STILL CARRY
LOW CHANCE POPS ACROSS THE SOUTHERN COUNTIES FRIDAY EVENING. THE
RAIN WILL COME TO AN END FRIDAY NIGHT AS THE FRONT PUSHES SOUTH OF
THE REGION. FORECAST SOUNDINGS ARE NOT VERY SUPPORTIVE OF A SEVERE
WEATHER POTENTIAL ON FRIDAY BUT CANNOT RULE OUT A FEW STRONG OR
POSSIBLY MARGINALLY SEVERE THUNDERSTORMS ALONG THE FRONT FRIDAY
AFTERNOON. WIND AND HAIL WOULD BOTH BE THREATS. AS MENTIONED IN
THE SPC DAY2 OUTLOOK...WILL ALSO HAVE TO WATCH FOR ANY OUTFLOW
BOUNDARIES COMING OFF THE OKLAHOMA MCS THAT COULD PROVIDE A FOCUS
FOR THUNDERSTORM DEVELOPMENT AHEAD OF THE FRONT.
HOWEVER...INCREASING CLOUD COVER AHEAD OF THE FRONT COULD INHIBIT
WARMING AND INSTABILITY ALONG ANY OUTFLOW BOUNDARIES.
TEMPERATURES TOMORROW WILL VARY FROM THE MID 80S IN THE NORTHEAST
WHERE THE HIGHEST RAIN CHANCES ARE TO THE UPPER 90S IN THE SOUTH.
HOWEVER... COOLER TEMPERATURES ARE EXPECTED REGION-WIDE OVER THE
WEEKEND WITH HIGHS ON SATURDAY IN THE LOWER 90S. THE UPPER LEVEL
RIDGE MOVES OVER THE REGION EARLY NEXT WEEK AND UPPER 90S TO
TRIPLE DIGITS WILL RETURN.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 78 95 72 92 73 / 20 40 30 10 5
WACO, TX 77 98 75 94 74 / 10 30 30 10 10
PARIS, TX 74 86 67 90 69 / 20 60 30 10 5
DENTON, TX 76 90 69 91 70 / 20 50 20 5 5
MCKINNEY, TX 75 89 69 91 70 / 20 50 30 10 5
DALLAS, TX 80 95 73 92 75 / 20 40 30 10 5
TERRELL, TX 77 94 71 92 71 / 10 50 30 10 5
CORSICANA, TX 77 97 74 93 73 / 10 40 30 10 10
TEMPLE, TX 75 98 75 94 73 / 10 30 30 10 10
MINERAL WELLS, TX 75 95 70 93 71 / 20 40 30 10 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
438 AM EDT FRI JUL 26 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA TODAY WILL MOVE OFFSHORE TONIGHT. A
COLD FRONT WILL APPROACH THE REGION SATURDAY...AND WILL CROSS THE
AREA SUNDAY. A LARGE HIGH PRESSURE SYSTEM WILL COVER MUCH OF THE
EASTERN UNITED STATES ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 420 AM EDT THURSDAY...
ISOLATED SHOWERS HAD DISSIPATED BUT SATELLITE PICTURES AND
SURFACE OBSERVATIONS SHOWED STRATOCUMULUS...MAINLY EAST OF THE
BLUE RIDGE AND PATCHY FOG IN THE VIRGINIA AND NORTH CAROLINA
FOOTHILLS. MORE WIDESPREAD FOG WAS DEVELOPING OVER WEST VIRGINIA.
00Z LOCAL WRF...LATEST RUC MODELS AND HUMIDITY FORECASTS FROM THE
NAM AD GFS ALL KEEP DEEPER MOISTURE AND BEST PROBABILITY OF
PRECIPITATION ALONG THE SOUTHERN BLUE RIDGE THIS AFTERNOON.
HIGH PRESSURE OVER THE FORECAST AREA THIS MORNING WILL MOVE EAST
THEN OFFSHORE BY THIS EVENING. WINDS WILL BE LIGHT THIS MORNING
THEN BECOME SOUTHEAST THIS AFTERNOON WHICH WILL HELP LIFT ALONG
THE BLUE RIDGE.
UPPER LOW DEVELOPING OVER THE WESTERN GREAT LAKES WILL BRING A
FRONT INTO THE OHIO VALLEY BY LATE TONIGHT. SURFACE FRONT EXPECTED
TO BE FROM EASTERN MICHIGAN TO SOUTHEAST MISSOURI...WELL WEST OF
THE FORECAST AREA. HAVE LOWERED THE CHANCE OF RAIN AFTER 06A/2AM.
850 MB TEMPERATURES WARM INTO THE +14 TO +16 RANGE BY 00Z/8PM
TONIGHT. USED A BLEND OF MET/MAV GUIDANCE FOR HIGHS TODAY AND LOWS
TONIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 400 AM EDT FRIDAY...
DEEP UPPER TROUGH TRAVELS EAST FROM THE GREAT LAKES INTO THE
NORTHEAST DURING THE PERIOD. INITIALLY TRIMMED BACK POPS SATURDAY
MORNING THEN KEPT LIKELY TO CAT POPS SATURDAY AFTERNOON INTO
SATURDAY NIGHT. GFS STILL SHOWED GOOD DYNAMICS WITH DECENT 25-30KT
LLJ/LOW-LEVEL SHEAR INDICATED WITH UPPER DIFFLUENCE PRESENT ACROSS
WESTERN PORTIONS OF THE REGION. LOCALIZED HEAVY RAINFALL WILL ALSO
BE A POSSIBILITY WITH STRONGER THUNDERSTORMS...BUT OVERALL
WIDESPREAD FLOODING NOT EXPECTED. WITH THE MOVEMENT OF THE
SHORTWAVE...SHIFT HIGHER POPS TO THE EAST SATURDAY NIGHT INTO
SUNDAY. DRY AIR PUSHES EAST ACROSS THE REGION ON SUNDAY INTO SUNDAY
NIGHT. UPPER TROUGH SHIFTS EAST OF THE REGION MONDAY. WEAK HIGH
PRESSURE BUILDS ACROSS THE REGION FROM THE OHIO VALLEY. REMOVED THE
MENTION OF THUNDERSTORMS FROM THE EAST AND SOUTH ON MONDAY. THE
COOLER AIRMASS REACHES THE PIEDMONT MONDAY NIGHT WITH LOWS DROPPING
INTO THE LOWER 60S IN SOUTHSIDE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 400 AM EDT FRIDAY...
SLOWED THE RETURN OF MOISTURE TUESDAY BUT ALLOWED FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE
WEST ESPECIALLY ALONG THE SOUTHERN BLUE RIDGE.
AFTER TUESDAY...A MUCH MORE UNSETTLED PATTERN RETURNS. THE
SUBTROPICAL RIDGE AMPLIFIES ACROSS THE CENTRAL/SOUTHERN PLAINS WITH
A ZONAL FLOW NOTED NORTH OF ABOUT 35 DEG LAT ACROSS MUCH OF THE U.S.
AN ALMOST ENDLESS SERIES OF DISTURBANCES TRACK WITHIN THIS ZONAL
FLOW AND IMPINGE ON AN INCREASINGLY WARM/HUMID AIR MASS ACROSS THE
REGION. 850MB TEMPS WILL WARM TOWARD +15 TO +18C BY THE END OF THE
WEEK.
WEDNESDAY APPEARS TO BE THE DAY WITH THE BEST POTENTIAL FOR
WIDESPREAD SHRA/TSRA ACTIVITY. IT APPEARS TO BE MORE OF A RAIN EVENT
THAN A SEVERE THUNDERSTORM EVENT AT THIS POINT AS INSTABILITY IS
MARGINAL. AS WE MOVE TOWARD THE WEEKEND...THERE IS SOME INDICATION
THAT A SERIES OF MCS/THUNDERSTORM COMPLEXES COULD EVOLVE ACROSS THE
MIDWEST/OHIO VALLEY AND SPREAD SE TOWARD OUR REGION. NOTABLE
INSTABILITY IS IN PLACE AT THAT TIME...SO WE WILL CERTAINLY NEED TO
KEEP AN EYE ON THIS INCREASINGLY VOLATILE PATTERN.
TEMPERATURES WILL START OUT WELL BELOW NORMAL...THEN TREND TOWARD
NORMAL FOR THE REMAINDER OF THE WEEK.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 200 AM EDT FRIDAY...
EXPECTING MVFR FOG AT DAN AMD BLF OVERNIGHT. STRATOCUMULUS MAY
KEEP FOG FROM DEVELOPING AT LYH UNTIL AROUND 11/7AM. MEDIUM
CONFIDENCE OF THE FORMATION OF IFR TO LIFR FOG AT LWB AND BCB
AFTER 09Z/5AM THIS MORNING.
ANY FOG WILL DISSIPATE BY 14Z/10AM FRIDAY. WINDS REMAIN WEAK ON
FRIDAY AS HIGH PRESSURE MOVES OFFSHORE AND A COLD FRONT APPROACHES FROM
THE WEST. THERE IS A LOW PROBABILITY OF SHOWERS ALONG THE SOUTHERN
APPALACHIANS...AND SOUTH OF KROA AND KBCB.
SATURDAY THROUGH SATURDAY NIGHT SHOWERS AND THUNDERSTORMS WILL
DEVELOP AHEAD OF THE FRONT. SOME OF THESE STORMS WILL HAVE GUSTY
WINDS AND SUB-VFR CEILINGS AND VISIBILITIES.
ON SUNDAY...THE FRONT WILL CROSS THE AREA WITH MORE SHOWERS AND
THUNDERSTORMS. THERE IS STILL A CHANCE OF LOCALIZED SUB-VFR
CONDITIONS EAST OF THE BLUE RIDGE.
MONDAY INTO TUESDAY...SURFACE HIGH PRESSURE BUILDS OVERHEAD. THIS
WILL YIELD LIGHT WINDS AND LIMITED CLOUD COVER...BUT NIGHTTIME AND
EARLY MORNING FOG AND STRATUS WILL BE POSSIBLE THANKS TO PLENTY OF
BOUNDARY LAYER MOISTURE IN PLACE AFTER THE RAIN OVER THE WEEKEND.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KK
LONG TERM...RAB
AVIATION...AMS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
315 AM CDT FRI JUL 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT FRI JUL 26 2013
THE MAIN FOCUS FOR TODAY IS ON THE PASSING COLD FRONT AND THE
CHANCES FOR CONVECTION ALONG IT.
CURRENTLY...THE FIRST IN A SERIES OF MID LEVEL SHORT WAVE TROUGHS
IN FAR SOUTHERN ONTARIO IS PROPAGATING EAST ALONG THE SOUTHERN
PERIPHERY OF A BROADER TROUGH THAT IS IN PLACE ACROSS MUCH OF
SOUTHEASTERN CANADA. THIS LEAD SHORTWAVE HAS BEEN GRADUALLY
WEAKENING AHEAD OF THE MAIN VORT MAX PER THE LATEST WATER VAPOR IR
IMAGERY AND BECOMING MORE EAST TO WEST ORIENTED ACROSS NORTH
CENTRAL WISCONSIN. THIS FEATURE HAS HELPED TO KEEP A BAND OF
SHOWERS/STORMS GOING ACROSS THIS REGION EARLY THIS MORNING.
DOWN AT THE SURFACE...A BROAD AREA OF LOW PRESSURE IS IN PLACE
FROM LAKE SUPERIOR WEST INTO NORTHERN MINNESOTA WITH A COLD FRONT
DROPPING SOUTH THROUGH EASTERN/SOUTH CENTRAL MINNESOTA ON INTO
NORTHWEST IOWA. 26.07Z RAP ANALYSIS SHOWS AN INSTABILITY AXIS OF
500-1000 J/KG OF 0-3KM MUCAPE IN PLACE AHEAD OF THIS FRONT FROM
NORTHWEST IOWA INTO NORTH CENTRAL WISCONSIN. THIS COMBINATION OF
THE FRONT AND INSTABILITY HAS BEEN ENOUGH TO FUEL SOME SCATTERED
CONVECTION ACROSS MINNESOTA EARLY THIS MORNING.
ALL INDICATIONS ARE THAT THE TROUGH/FRONT ARE GOING TO PASS
THROUGH RATHER QUICKLY TODAY AS THIS MAIN MID LEVEL TROUGH WRAPS
UP. THERE DOES APPEAR TO BE A BRIEF WINDOW FOR THE DEVELOPMENT OF
SEVERE THUNDERSTORMS IN WESTERN WISCONSIN LATER THIS MORNING AND
INTO THE EARLY AFTERNOON AS INSTABILITY BUILDS INTO THE
1000-1500J/KG RANGE AND A 500MB JET STREAK PUSHES INTO CENTRAL
WISCONSIN. MUCH OF THE 26.00Z TO 26.06Z MESO-GUIDANCE SUGGESTS
THAT THE COLD FRONT IS ALREADY GOING TO BE INTO CENTRAL WISCONSIN
BY 17-19Z WITH ANY SEVERE POTENTIAL COMING AHEAD OF THIS FRONT. AM
NOT EXPECTING A WIDESPREAD SEVERE OUTBREAK BY ANY MEANS...BUT THE
INCREASING INSTABILITY AND INCREASING MID LEVEL WINDS WILL HELP TO
ORGANIZE A FEW UPDRAFTS AND SHOULD PRODUCE A FEW SEVERE STORMS
WITH LARGE HAIL THE MAIN HAZARD DUE TO THE LOW FREEZING LEVELS.
THE HIGHER SEVERE CHANCES WILL BE INTO CENTRAL/EASTERN WISCONSIN
WHERE THERE WILL BE A LONGER PERIOD OF WARMING BEFORE THE STORMS
GET IN.
AS THE CORE OF THE MID LEVEL TROUGH TRACKS THROUGH THIS
AFTERNOON...A SECONDARY COLD FRONT/TROUGH WILL DROP SOUTH ACROSS
THE REGION AND COULD BE A FOCUS FOR SOME SHOWER DEVELOPMENT. WINDS
WILL PICK UP AND TEMPERATURES WILL DROP BEHIND BOTH FRONTS TO MARK
THE BEGINNING OF AN UNSEASONABLY COOL PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI JUL 26 2013
THE FOCUS THEN SHIFTS TO HOW COLD IT WILL BE THIS WEEKEND AS AN
ANOMALOUSLY COOL AIR MASS GETS PULLED DOWN INTO THE REGION FROM
NORTH CENTRAL CANADA. THE 26.00Z NAM/GFS/ECMWF 850MB TEMPERATURE
ANOMALIES AT -1.5 TO -2.5 DEVIATIONS FROM THE NORM WHICH TYPICALLY
INDICATE NEAR RECORD TO RECORD COLD TEMPERATURES. WITH QUESTIONS
IN THE AMOUNT OF CLOUD COVER LINGERING...HAVE NOT GONE BELOW
RECORD LOWS OR RECORD LOW MAXIMUM TEMPERATURES BUT HAVE KEPT THEM
CLOSE. AT LSE...THE RECORD LOW HIGH FOR SATURDAY IS 69 AND FOR
SUNDAY IS 66 WHILE THE RECORD LOWS ARE 48 ON SATURDAY/50 ON
SUNDAY. AT RST...THE LOW MAX FOR SATURDAY IS 64/SUNDAY IS 63 WHILE
THE RECORD LOW IS 47 ON BOTH SATURDAY AND SUNDAY. 26.00Z FORECAST
SOUNDINGS SHOW SOME INSTABILITY DEVELOPING IN THE AFTERNOON TO
WHERE SOME DIURNALLY DRIVEN SHOWERS SHOULD DEVELOP...PARTICULARLY
IN WESTERN WISCONSIN WHICH WILL BE CLOSER TO THE UPPER LEVEL
TROUGH.
AS THE MID LEVEL LOW WOBBLES EASTWARD INTO THE EARLY PORTION OF
NEXT WEEK...THE NEXT MID LEVEL TROUGH...WHICH IS CURRENTLY IN FAR
SOUTHWEST CANADA...WILL TRACK EAST ACROSS CANADA. INSTABILITY WILL
BE ON THE INCREASE ON THE WESTERN PERIPHERY OF THE SURFACE RIDGE
WITH SOME SMALL CHANCES FOR CONVECTION MONDAY NIGHT THROUGH
THURSDAY. NOT OVERLY CONFIDENT THAT ALL OF THESE PRECIPITATION
CHANCES ARE NEEDED...BUT WITH THE LINGERING TROUGH NEARBY CAN NOT
RULE THEM OUT. A GRADUAL WARMING TREND IS EXPECTED WITH 850MB
TEMPERATURES RISING FROM +4C ON SATURDAY TO +13C BY TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1147 PM CDT THU JUL 25 2013
STILL SOME SCATTERED CONVECTION UP STREAM OF THE AREA ALONG THE
PRE-FRONTAL TROUGH. GIVEN THE CURRENT MOVEMENT OF THIS
ACTIVITY...IT LOOKS LIKE IT SHOULD PASS NORTH OF BOTH TAF
SITES...BUT MAY COME CLOSE ENOUGH TO KLSE TO INCLUDE THE MENTION
OF A VCSH AROUND 09Z. LITTLE OR NO CAPE IS IN PLACE SO IF THE
ACTIVITY DOES HOLD TOGETHER WOULD NOT EXPECT IT TO STILL BE
PRODUCING ANY LIGHTNING AND ENTIRELY POSSIBLE THAT IT WILL
COMPLETELY DISSIPATE BEFORE GETTING TO THE AREA ONCE IT RUNS OUT
OF CAPE. STILL THE POSSIBILITY OF SOME FOG OVERNIGHT AS SKIES ARE
CLEARING AND WITH THE MOISTURE FROM TODAY/S RAIN...COULD SEE SOME
MVFR VISIBILITIES OVERNIGHT. THE COLD FRONT LOOKS TO COME THROUGH
DURING THE EARLY TO MID MORNING HOURS SWITCHING THE WINDS AROUND
TO THE NORTHWEST WITH GUSTS DEVELOPING DURING THE AFTERNOON. GOOD
LAPSE RATES WILL DEVELOP BEHIND THE FRONT AND WITH THE CYCLONIC
FLOW ALOFT AND SOME LIFT FROM THE PASSING SHORT WAVE TROUGH...SOME
SHOWERS STILL EXPECTED TO FORM OVER WISCONSIN. WILL CONTINUE TO
SHOW A VCSH AT KLSE DURING THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...04
AREA FORECAST DISCUSSION
NWS BOISE ID
931 AM MDT FRI JUL 26 2013
.DISCUSSION...CURRENT FORECAST HAS BEST CHANCE OF THUNDERSTORMS IN
SERN OREGON AND ALONG THE ID/NV BORDER THIS AFTERNOON AND TONIGHT...
AND A LESSER CHANCE IN THE IDAHO CENTRAL MOUNTAINS LATE TODAY AND
THIS EVENING. FINER DETAILS IN THE HRRR MODEL EMPHASIZE SRN HARNEY
COUNTY FOR THE GREATEST ACTIVITY. YESTERDAY THE HRRR VERY
ACCURATELY PREDICTED THUNDERSTORMS JUST SW OF HARNEY COUNTY THURSDAY
EVENING WITH OUTFLOW WINDS INTO SRN HARNEY. WE WILL UPDATE CURRENT
FORECAST TO EXTEND CHANCE OF SHOWERS AND THUNDERSTORMS BEYOND 06Z
TONIGHT IN SERN OREGON. A RED FLAG WARNING FOR LIGHTNING IS NOW IN
EFFECT THERE. THAT AREA IS STILL UNDER HIGH-LEVEL MOISTURE OUTFLOW
FROM TROPICAL STORM FLOSSIE OFF MEXICO. LATE SATURDAY NIGHT AND
SUNDAY A SIGNIFICANT UPPER TROUGH IN WESTERN CANADA WILL COME IN
WITH A CHANGE TO COOLER CONDITIONS. TROUGH WILL ALSO PUSH THE
MID/HIGH-LEVEL MOISTURE OUT TO THE EAST.
&&
.AVIATION...VFR UNDER SCATTERD CUMULUS CLOUDS TODAY. SCATTERED
THUNDERSTORMS TO DEVELOP AFTER 21Z MAINLY ACROSS SE OREGON AND THE
MOUNTAINS OF WEST CENTRAL IDAHO. STORMS MAY PRODUCE GUSTY OUTFLOW
WINDS IN EXCESS OF 30 KTS. EXPECT THUNDERSTORM ACTIVITY TO LAST
THROUGH 06Z. LIGHT SW TO NW SURFACE WINDS AT 10-15 KTS THIS
AFTERNOON. VARIABLE WINDS ALOFT GENERALLY LESS THAN 10 KTS UP
THROUGH 10K FEET MSL.
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH SATURDAY...MOISTURE THAT HAS BEEN DRAWN
NORTH OUT OF THE TROPICS /CLEARLY DEPICTED IN THE WATER VAPOR
SATELLITE LOOP/ WILL FEED CONVECTIVE DEVELOPMENT OVER SE OREGON AND
HIGHER TERRAIN OF SW IDAHO TODAY. MID-LEVEL ENERGY TRACKING ACROSS
THE SOUTHERN BORDER REGION WITH NV WILL PROVIDE THE BEST CHANCE FOR
SHOWERS AND THUNDERSTORMS. ELSEWHERE AFTERNOON INSTABILITY WILL
DRIVE ISOLATED SHOWERS AND STORMS ACROSS THE MTNS OF EAST-CENTRAL
OREGON AND THE WEST CENTRAL AND BOISE MTNS OF ID. WITH THE DRY
SUB-CLOUD ENVIRONMENT GUSTY WINDS TO 45 MPH ARE AGAIN POSSIBLE WITH
SHOWERS OR STORMS THAT DEVELOP. WILL ALSO NEED TO WATCH AMOUNT OF
ACTIVITY THAT DEVELOPS SOUTH OF THE SNAKE RIVER FOR POTENTIAL
OUTFLOW WINDS PUSHING INTO THE TREASURE AND WESTERN MAGIC VALLEYS
THIS EVENING. AN UPPER TROUGH OVER THE NORTHERN PACIFIC WILL DROP
INTO THE PAC NW ON SATURDAY WITH AN ACCOMPANYING COLD FRONT. THE
MODELS HAVE SLOWED DOWN SOME IN TIMING THIS FRONT WHICH WOULD LEAD
TO WARMER AFTERNOON HIGHS. THE FRONTAL PASSAGE ITSELF IS DRY BUT
CONTINUED MOIST SW FLOW OUT AHEAD OF IT WILL KEEP A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS OVER THE EASTERN BOISE MTNS AND WESTERN
MAGIC VALLEY ON SATURDAY.
LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...BREEZY NORTHWEST WINDS
ON SUNDAY BEHIND A COLD FRONT WILL BRING COOLER AIR TO SOUTHEASTERN
OREGON AND SOUTHWESTERN IDAHO. THERE WILL BE AT ABOUT A 10 DEGREE
DROP IN TEMPERATURES FROM SATURDAY INTO SUNDAY. THE COOLER WEATHER
SHOULD LAST ALL WEEK WITH TEMPERATURES AVERAGING A FEW DEGREES BELOW
NORMAL. THERE IS NOT MUCH IN THE WAY OF MOISTURE WITH THE FRONT AND
EVEN DRIER AIR BEHIND IT...SO EXPECT MOSTLY CLEAR SKIES THOUGH THE
PERIOD EXCEPT IN THE CENTRAL MOUNTAINS OF IDAHO WHERE AFTERNOON
BUILD UPS OF CUMULUS CLOUDS COULD RESULT IN FEW LIGHTNING STRIKES
EACH DAY.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...RED FLAG WARNING FROM 4 PM MDT / 3 PM PDT/ THIS AFTERNOON TO
MIDNIGHT MDT / 11 PM PDT/ TONIGHT ORZ636-637.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...LC
AVIATION.....CB
PREV SHORT TERM...DG
PREV LONG TERM....JB
AREA FORECAST DISCUSSION
NWS LINCOLN IL
916 AM CDT FRI JUL 26 2013
.DISCUSSION...
ISSUED 916 AM CDT FRI JUL 26 2013
14Z/9AM RADAR IMAGERY SHOWS SHOWERS PUSHING ACROSS THE NORTHWEST
KILX CWA...WITH RAIN BEING REPORTED AT BOTH KGBG AND KPIA. AIRMASS
IS INITIALLY QUITE DRY BELOW 850MB...SO RAIN WILL HAVE DIFFICULTY
TRACKING MUCH FURTHER EAST. HAVE UPDATED POPS TO CATEGORICAL ALONG
AND NORTH OF A RUSHVILLE TO BLOOMINGTON-NORMAL LINE...BUT WILL
HANG ON TO JUST CHANCE POPS FURTHER SOUTHEAST TO THE I-72 CORRIDOR.
THINK SHOWERS WILL ADVANCE EASTWARD AND GRADUALLY DISSIPATE AS
THEY APPROACH THE INDIANA BORDER EARLY THIS AFTERNOON. AFTER
THAT...HIGH-RES HRRR SHOWS ADDITIONAL SHOWERS/THUNDER FORMING
ALONG A SLOWLY ADVACING COLD FRONT WEST OF THE ILLINOIS RIVER BY
LATE THIS AFTERNOON. THIS CONVECTION WILL WORK ITS WAY EASTWARD
ACROSS THE AREA THIS EVENING. ZONE UPDATE HAS ALREADY BEEN SENT.
BARNES
&&
.AVIATION...
ISSUED 640 AM CDT FRI JUL 26 2013
A FRONT WILL BRING IN SCATTERED SHOWERS THIS MORNING...AFFECTING
MAINLY PIA TAF. SPI AND BMI COULD ALSO SEE SOME SCATTERED SHOWERS
SO WILL HAVE ALL THREE SITES AT VCSH THIS MORNING. DEC AND CMI
SHOULD REMAIN DRY AS ATMOSPHERE LACKS MOISTURE AND ALL THE SUPPORT
THAT WAS THERE EARLY IS NOW GONE. THIS CURRENT PCPN IS MAINLY THE
REMNANTS OF OF CONVECTION THAT OCCURRED WEST OF THE AREA YESTERDAY
EVENING. FRONT THOUGH IS STILL WEST OF THE AREA AND STILL
EXPECTING SOME MORE ISOLATED SHOWERS AND THUNDERSTORMS THIS
AFTERNOON AND EARLY THIS EVENING WHEN THE FRONT MOVES INTO AND
THROUGH THE AREA. SO HAVE VCTS FOR EVENING HOURS. CHANCES OF PCPN
WILL END AFTER MIDNIGHT...BUT CLOUDS WILL HANG AROUND. WINDS WILL
BE SOUTHERLY TO SOUTHWESTERLY AHEAD OF THE FRONT...THEN BECOME
WEST TO NORTHWESTERLY AFTER FROPA THIS EVENING.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 348 AM CDT FRI JUL 26 2013
PRECIPITATION MOVING CLOSER AHEAD OF AN ADVANCING COLD FRONT
MOVING INTO THE REGION. THE FRONT WILL DRIVE THE FORECAST IN THE
SHORT TERM WITH POPS FOR TODAY AND TONIGHT SLOWLY TAKING OVER THE
HIGH PRESSURE SLIDING OFF TO THE EAST. SYNOPTIC SCALE TROF AT H5
IN THE UPPER MIDWEST AND GREAT LAKES DRIVING THE FRONT INTO AND
ACROSS THE MIDWEST. COOLER TEMPS AND PARTLY CLOUDY SKIES WILL
DOMINATE THROUGH MOST OF THE WEEKEND WITH THE TROF REMAINING IN
PLACE OVER THE GREAT LAKES AND LEAVING CYCLONIC FLOW ALOFT. NEXT
ISSUES FOR THE FORECAST WILL BE THE NEXT SYSTEM MON/TUESDAY THAT
THE MODELS ARE STILL HAVING A BIT OF A DISAGREEMENT ABOUT...THOUGH
THE OFFICIAL FORECAST IS LEANING TOWARDS THE ECMWF OVERALL...WITH
A SLIGHTLY MORE AGGRESSIVE ADVANCE OF THE QPF ON MON NIGHT.
SHORT TERM...TODAY AND TOMORROW...
FASTER ADVANCE OF THE FRONT IN THE FORECAST...WITH THE PRE FRONTAL
PRECIP ALREADY TO THE NW AND CREEPING INTO THE FA. ADVANCING THE
POPS THROUGH THE AFTERNOON AND EVENING. ISO TS IN THE
MORNING...THOUGH SHOWERS MAY SCATTER A BIT INTO THE
AFTERNOON...THE THUNDER WILL MORE LIKELY ACCOMPANY THE ACTIVITY.
WITH THE FASTER MOVEMENT...THE FORECAST DRIES CONSIDERABLY GOING
INTO SATURDAY. THOUGH THE CYCLONIC FLOW ALOFT AND MODERATE RH IN
THE BOUNDARY LAYER...FORECAST SOUNDINGS ARE HINTING AT A BIT OF A
CAP ABOVE 800MB RESULTING IN A BIT OF A LIMITATION TO CONVECTIVE
GROWTH. SO INSTABILITY SHOWERS THAT MAY HAVE BEEN A RISK FOR SAT
AFTERNOON WILL BE LIMITED SOMEWHAT SHOULD THAT CAP MATERIALIZE.
WILL NEED TO KEEP AN EYE ON THAT PORTION OF THE FORECAST. THOUGH
TEMPERATURES TODAY WILL BE IN THE UPPER 70S/NEAR 80...TOMORROW
BEHIND THE FRONT WILL BE CONSIDERABLY COOL FOR THE END OF
JULY...WITH HIGHS IN THE LOW TO MID 70S. SAT NIGHT/SUN MORNING
WITH CLEARING SKIES AND MUCH COLDER AIR MOVING INTO THE
MIDLEVELS...6 TO 7C AT 850...SAT NIGHT TEMPS DROP INTO THE LOWER
50S.
LONG TERM...SUNDAY THROUGH THURSDAY...
WESTERLY FLOW SETS UP AT THE SFC TRYING TO ADVECT SOME WARMER
TEMPS FROM UNDER THE PERSISTENT AND EXPANSIVE RIDGE OVER THE
WESTERN HALF OF THE CONUS...BUT THE WARM UP IS SLOW THROUGH SUN
AND MON. NEXT ISSUE ARRIVES MON NIGHT. GFS IS FAR MORE
CONSERVATIVE FOR ILX YET AGAIN...KEEPING THE SFC LOW FURTHER SOUTH
AND THE ECMWF BEING THE MORE EXPANSIVE WITH THE QPF AND MORE
PROLONGED WITH SOME SLIGHT CONVECTIVE FEEDBACK ISSUES THROUGH
WEDNESDAY. ALLBLEND SEEMS TO LEAN HEAVILY TOWARDS THE MORE
AGGRESSIVE AND WET ECMWF. TEMPERATURES CONTINUE TO MODERATE
THROUGH THE EXTENDED AS QUASI ZONAL FLOW SETS UP ACROSS THE
COUNTRY IN THE LAST HALF OF THE WORK WEEK.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
938 AM EDT FRI JUL 26 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE TO THE NORTHEAST ALONG A FRONT ACROSS THE
GULF OF MAINE TODAY AND INTO THE MARITIMES TONIGHT. THIS WILL
PROVIDE RAIN FOR MUCH OF THE REGION INTO TONIGHT WITH THE HEAVIEST
RAIN EXPECTED OVER MORE EASTERN AREAS OF MAINE WHILE NEW HAMPSHIRE
SEES THE LOWEST RAINFALL TOTALS. A WEAK AREA OF HIGH PRESSURE
BUILDS INTO THE REGION ON SATURDAY GIVING US VERY WARM AND DRY
WEATHER. A SLOW-MOVING COLD FRONT WILL APPROACH FROM THE GREAT
LAKES LATE SUNDAY THEN EXIT THE COAST ON MONDAY. AN UPPER LOW WILL
PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR TUESDAY. A WEAK
RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER DISTURBANCE
WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LIGHT RAIN CONTINUES OVER SOUTHERN AREAS PER LATEST OBSERVATIONS
AND RADAR TRENDS. THE INTENSITY WILL LIKELY PICK UP OVER THE NEXT
FEW HOURS AS LOW PRESSURE CROSSES THROUGH THE GULF OF MAINE THIS
AFTERNOON. LATEST HRRR RUN SHOWS MAIN BULK OF PCPN RIDING JUST
EAST OF OUR FORECAST AREA...FROM THE PENOBSCOT RIVER VALLEY AND
POINTS EAST...BRINGING A QUICK 2 INCHES OF RAIN THIS AFTERNOON
ALONG THE EASTERNMOST PORTIONS OF OUR FORECAST AREA. THIS IS JUST
BELOW FLASH FLOOD GUIDANCE. HOWEVER...WILL CONTINUE TO MONITOR
EASTERN AREAS FOR THE POTENTIAL FOR HEAVY RAINFALL AS PRECIPITABLE
WATER VALUES REMAIN VERY HIGH DURING THE AFTERNOON.
OTHERWISE...ONLY MINOR MODIFICATIONS TO THE GRIDS THIS MORNING.
PREV DISC...
WILL UPDATE TO INPUT LATEST OBSERVED DATA...RESULTING IN
SLOWING DOWN THE ONSET OF RAIN ACROSS THE FCST AREA THIS MORNING.
RAIN HAS MOVED INTO COASTAL AND ADJACENT INTERIOR ZONES BUT HASN`T
PUSHED MUCH FURTHER INLAND AT THIS TIME. STILL EXPECT RAIN TO
SURGE NORTHWARD ACROSS THE FCST AREA TODAY.
THE TRACK OF THE SFC LOW WILL BE ALONG A STALLED FRONT OVER THE
GULF OF MAINE TODAY. THIS WILL SPREAD RAIN ACROSS MUCH OF THE
FORECAST AREA WITH THE HEAVIEST RAIN OVER EASTERN AREAS...WHILE
NEW HAMPSHIRE...ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY SEE
MUCH LESS RAINFALL. TEMPERATURES SHOULDN`T WARM UP TOO MUCH TODAY
DUE TO CLOUDS AND RAIN...WITH THE WARMEST READINGS LIKELY IN NH
ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY. BREEZY NORTH
NORTHEAST WINDS WILL OCCUR TODAY...MORE SO OVER MAINE THAN NH.
GENERALLY USED A BLEND OF GFS/NAM AND MET/MAV MOS GUIDANCE FOR THE
NEAR TERM FCST. USED HPC QPF TO START...THOUGH DID ADJUST
SOMEWHAT. QPF WILL RANGE FROM LESS THAN A QUARTER OF AN INCH
ACROSS THE MAINE MOUNTAINS TO NORTHERN AND WESTERN NH TO AN INCH
TO AN INCH AND A HALF OVER THE MID COAST OF MAINE.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE SFC LOW TRACKS INTO THE MARITIMES TONIGHT BRINGING AN END TO
THE RAIN FROM SOUTHWEST TO NORTHEAST. AREAS OF FOG WILL FORM IN
THE MOIST BOUNDARY LAYER ESPECIALLY FOR AREAS THAT SEE SOME
CLEARING AND HAD A FAIR AMOUNT OF RAINFALL. TOTAL QPF THROUGH
TONIGHT WILL RANGE FROM LESS THAN A QUARTER OF AN INCH ACROSS
NORTHERN AND WESTERN NH TO AROUND TWO INCHES OVER THE MID COAST OF
MAINE WITH SOME HIGHER AMOUNTS POSSIBLE. NOT ANTICIPATING FLOOD
ISSUES WITH THIS EVENT BUT THERE IS THE OUTSIDE CHANCE THAT IF
CLOSER TO 3 /OR MORE/ INCHES OF RAIN FALL THEN THERE MAY BE SOME
MINOR FLOOD PROBLEMS OVER THE MID COAST OF MAINE AND INTO AREAS
JUST TO THE SW...W AND N. AT THIS TIME WILL NOT PUT UP A FLOOD
WATCH. GENERALLY USED A BLEND OF NAM/GFS...MET/MAV MOS AND HPC/RFC
QPF FOR THE SHORT TERM FCST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
WE BEGIN THE PERIOD WITH A SHORTWAVE RIDGE EXITING INTO THE
MARITIMES...AND AN UPPER LOW OVER THE GREAT LAKES SLIDING
EASTWARD INTO NEW ENGLAND. THE UPPER LOW WILL LIFT TO OUR NORTH
AND EAST EARLY NEXT WEEK...WITH A BROAD TROUGH EXTENDING ROM THE
GREAT LAKES INTO NEW ENGLAND IN ITS WAKE. THE UPSHOT OF THIS
PATTERN WILL BE THAT EXCESSIVE HEAT AND HUMIDITY WILL REMAIN WELL
TO OUR SOUTH AND WEST THROUGH THE PERIOD.
IN THE DAILIES...A SLOW-MOVING COLD FRONT APPROACHES FROM THE
GREAT LAKES LATE SUNDAY THEN EXITS THE COAST DURING MONDAY. AN
UPPER LOW WILL PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR
TUESDAY. A WEAK RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY.
ANOTHER DISTURBANCE WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH SATURDAY/...CONDITIONS WILL LOWER WITH
RAIN OVERSPREADING MUCH OF THE REGION TODAY. LOWEST CONDITIONS
OVER MORE EASTERN AND COASTAL AREAS AND HIGHEST CONDITIONS OVER
MORE NORTHERN AND WESTERN AREAS. THUS EXPECT RKD...AUG...PWM AND
PSM TO HAVE LOWEST CIG/VSBY WHILE LEB AND HIE THE HIGHEST CIG/VSBY
WITH CON IN BETWEEN. AS THE RAIN ENDS FROM SW TO NE TONIGHT EXPECT
SOME CLEARING TO FOLLOW BUT THAT WILL ALLOW FOG TO FORM...
ESPECIALLY IN AREAS THAT SEE THE MOST CLEARING BUT ALSO HAD
SIGNIFICANT AMOUNTS OF RAINFALL.
LONG TERM...
SUN PM - MON...MVFR LIKELY IN SHOWERS AND SCT TSTMS.
&&
.MARINE...
SHORT TERM /FRIDAY THROUGH SATURDAY/...WILL UPDATE TO INPUT LATEST
OBSERVED DATA RESULTING IN NO MORE THAN A FEW MINOR ADJUSTMENTS TO
THE PREVIOUS FORECAST. WILL CONTINUE THE SCA FOR THE OUTER WATERS
INTO TONIGHT AS THE SFC LOW MOVES TO THE NE ACROSS THE GULF OF
MAINE TODAY AND INTO THE MARITIMES TONIGHT. EXPECT WIND GUSTS OF
25 KT AND MAYBE EVEN UP TO 30 KT. SEAS WILL BUILD TO 5 OR 6 FT
OVER THE OPEN WATERS. WINDS LET UP AND DROP BELOW SCA LEVELS
TONIGHT. SEAS WILL BE SLOWER TO SUBSIDE AND MAY NOT DROP BELOW SCA
LEVELS UNTIL SATURDAY. HIGH PRESSURE WILL RESULT IN WINDS AND SEAS
BELOW SCA LEVELS ON SATURDAY.
LONG TERM...
SUN NIGHT - MON...WINDS AND SEAS MAY APPROACH SCA THRESHOLD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ150-152-
154.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
936 AM EDT FRI JUL 26 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE TO THE NORTHEAST ALONG A FRONT ACROSS THE
GULF OF MAINE TODAY AND INTO THE MARITIMES TONIGHT. THIS WILL
PROVIDE RAIN FOR MUCH OF THE REGION INTO TONIGHT WITH THE HEAVIEST
RAIN EXPECTED OVER MORE EASTERN AREAS OF MAINE WHILE NEW HAMPSHIRE
SEES THE LOWEST RAINFALL TOTALS. A WEAK AREA OF HIGH PRESSURE
BUILDS INTO THE REGION ON SATURDAY GIVING US VERY WARM AND DRY
WEATHER. A SLOW-MOVING COLD FRONT WILL APPROACH FROM THE GREAT
LAKES LATE SUNDAY THEN EXIT THE COAST ON MONDAY. AN UPPER LOW WILL
PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR TUESDAY. A WEAK
RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER DISTURBANCE
WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LIGHT RAIN CONTINUES OVER SOUTHERN AREAS PER LATEST OBSERVATIONS
AND RADAR TRENDS. THE INTENSITY WILL LIKELY PICK UP OVER THE NEXT
FEW HOURS AS LOW PRESSURE CROSSES THROUGH THE GULF OF MAINE THIS
AFTERNOON. LATEST HRRR RUN SHOWS MAIN BULK OF PCPN RIDING JUST
EAST OF OUR FORECAST AREA...FROM THE PENOBSCOT RIVER VALLEY AND
POINTS EAST...BRINGING A QUICK 2 INCHES OF RAIN THIS AFTERNOON
ALONG THE EASTERNMOST PORTIONS OF OUR FORECAST AREA. THIS IS JUST
BELOW FLASH FLOOD GUIDANCE. THEREFORE...WILL CONTINUE TO MONITOR EASTERN AREAS FOR THE
POTENTIAL FOR HEAVY RAINFALL.
OTHERWISE...ONLY MINOR MODIFICATIONS TO THE GRIDS THIS MORNING.
PREV DISC...
WILL UPDATE TO INPUT LATEST OBSERVED DATA...RESULTING IN
SLOWING DOWN THE ONSET OF RAIN ACROSS THE FCST AREA THIS MORNING.
RAIN HAS MOVED INTO COASTAL AND ADJACENT INTERIOR ZONES BUT HASN`T
PUSHED MUCH FURTHER INLAND AT THIS TIME. STILL EXPECT RAIN TO
SURGE NORTHWARD ACROSS THE FCST AREA TODAY.
THE TRACK OF THE SFC LOW WILL BE ALONG A STALLED FRONT OVER THE
GULF OF MAINE TODAY. THIS WILL SPREAD RAIN ACROSS MUCH OF THE
FORECAST AREA WITH THE HEAVIEST RAIN OVER EASTERN AREAS...WHILE
NEW HAMPSHIRE...ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY SEE
MUCH LESS RAINFALL. TEMPERATURES SHOULDN`T WARM UP TOO MUCH TODAY
DUE TO CLOUDS AND RAIN...WITH THE WARMEST READINGS LIKELY IN NH
ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY. BREEZY NORTH
NORTHEAST WINDS WILL OCCUR TODAY...MORE SO OVER MAINE THAN NH.
GENERALLY USED A BLEND OF GFS/NAM AND MET/MAV MOS GUIDANCE FOR THE
NEAR TERM FCST. USED HPC QPF TO START...THOUGH DID ADJUST
SOMEWHAT. QPF WILL RANGE FROM LESS THAN A QUARTER OF AN INCH
ACROSS THE MAINE MOUNTAINS TO NORTHERN AND WESTERN NH TO AN INCH
TO AN INCH AND A HALF OVER THE MID COAST OF MAINE.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE SFC LOW TRACKS INTO THE MARITIMES TONIGHT BRINGING AN END TO
THE RAIN FROM SOUTHWEST TO NORTHEAST. AREAS OF FOG WILL FORM IN
THE MOIST BOUNDARY LAYER ESPECIALLY FOR AREAS THAT SEE SOME
CLEARING AND HAD A FAIR AMOUNT OF RAINFALL. TOTAL QPF THROUGH
TONIGHT WILL RANGE FROM LESS THAN A QUARTER OF AN INCH ACROSS
NORTHERN AND WESTERN NH TO AROUND TWO INCHES OVER THE MID COAST OF
MAINE WITH SOME HIGHER AMOUNTS POSSIBLE. NOT ANTICIPATING FLOOD
ISSUES WITH THIS EVENT BUT THERE IS THE OUTSIDE CHANCE THAT IF
CLOSER TO 3 /OR MORE/ INCHES OF RAIN FALL THEN THERE MAY BE SOME
MINOR FLOOD PROBLEMS OVER THE MID COAST OF MAINE AND INTO AREAS
JUST TO THE SW...W AND N. AT THIS TIME WILL NOT PUT UP A FLOOD
WATCH. GENERALLY USED A BLEND OF NAM/GFS...MET/MAV MOS AND HPC/RFC
QPF FOR THE SHORT TERM FCST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
WE BEGIN THE PERIOD WITH A SHORTWAVE RIDGE EXITING INTO THE
MARITIMES...AND AN UPPER LOW OVER THE GREAT LAKES SLIDING
EASTWARD INTO NEW ENGLAND. THE UPPER LOW WILL LIFT TO OUR NORTH
AND EAST EARLY NEXT WEEK...WITH A BROAD TROUGH EXTENDING ROM THE
GREAT LAKES INTO NEW ENGLAND IN ITS WAKE. THE UPSHOT OF THIS
PATTERN WILL BE THAT EXCESSIVE HEAT AND HUMIDITY WILL REMAIN WELL
TO OUR SOUTH AND WEST THROUGH THE PERIOD.
IN THE DAILIES...A SLOW-MOVING COLD FRONT APPROACHES FROM THE
GREAT LAKES LATE SUNDAY THEN EXITS THE COAST DURING MONDAY. AN
UPPER LOW WILL PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR
TUESDAY. A WEAK RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY.
ANOTHER DISTURBANCE WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH SATURDAY/...CONDITIONS WILL LOWER WITH
RAIN OVERSPREADING MUCH OF THE REGION TODAY. LOWEST CONDITIONS
OVER MORE EASTERN AND COASTAL AREAS AND HIGHEST CONDITIONS OVER
MORE NORTHERN AND WESTERN AREAS. THUS EXPECT RKD...AUG...PWM AND
PSM TO HAVE LOWEST CIG/VSBY WHILE LEB AND HIE THE HIGHEST CIG/VSBY
WITH CON IN BETWEEN. AS THE RAIN ENDS FROM SW TO NE TONIGHT EXPECT
SOME CLEARING TO FOLLOW BUT THAT WILL ALLOW FOG TO FORM...
ESPECIALLY IN AREAS THAT SEE THE MOST CLEARING BUT ALSO HAD
SIGNIFICANT AMOUNTS OF RAINFALL.
LONG TERM...
SUN PM - MON...MVFR LIKELY IN SHOWERS AND SCT TSTMS.
&&
.MARINE...
SHORT TERM /FRIDAY THROUGH SATURDAY/...WILL UPDATE TO INPUT LATEST
OBSERVED DATA RESULTING IN NO MORE THAN A FEW MINOR ADJUSTMENTS TO
THE PREVIOUS FORECAST. WILL CONTINUE THE SCA FOR THE OUTER WATERS
INTO TONIGHT AS THE SFC LOW MOVES TO THE NE ACROSS THE GULF OF
MAINE TODAY AND INTO THE MARITIMES TONIGHT. EXPECT WIND GUSTS OF
25 KT AND MAYBE EVEN UP TO 30 KT. SEAS WILL BUILD TO 5 OR 6 FT
OVER THE OPEN WATERS. WINDS LET UP AND DROP BELOW SCA LEVELS
TONIGHT. SEAS WILL BE SLOWER TO SUBSIDE AND MAY NOT DROP BELOW SCA
LEVELS UNTIL SATURDAY. HIGH PRESSURE WILL RESULT IN WINDS AND SEAS
BELOW SCA LEVELS ON SATURDAY.
LONG TERM...
SUN NIGHT - MON...WINDS AND SEAS MAY APPROACH SCA THRESHOLD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ150-152-
154.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
854 AM EDT FRI JUL 26 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE TO THE NORTHEAST ALONG A FRONT ACROSS THE
GULF OF MAINE TODAY AND INTO THE MARITIMES TONIGHT. THIS WILL
PROVIDE RAIN FOR MUCH OF THE REGION INTO TONIGHT WITH THE HEAVIEST
RAIN EXPECTED OVER MORE EASTERN AREAS OF MAINE WHILE NEW HAMPSHIRE
SEES THE LOWEST RAINFALL TOTALS. A WEAK AREA OF HIGH PRESSURE
BUILDS INTO THE REGION ON SATURDAY GIVING US VERY WARM AND DRY
WEATHER. A SLOW-MOVING COLD FRONT WILL APPROACH FROM THE GREAT
LAKES LATE SUNDAY THEN EXIT THE COAST ON MONDAY. AN UPPER LOW WILL
PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR TUESDAY. A WEAK
RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER DISTURBANCE
WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LIGHT RAIN CONTINUES OVER SOUTHERN AREAS PER LATEST OBSERVATIONS
AND RADAR TRENDS. THE INTENSITY WILL LIKELY PICK UP OVER THE NEXT
FEW HOURS AS LOW PRESSURE CROSSES THROUGH THE GULF OF MAINE THIS
AFTERNOON. LATEST HRRR RUN SHOWS MAIN BULK OF PCPN RIDING JUST
EAST OF OUR FORECAST AREA...FROM THE PENOBSCOT RIVER VALLEY AND
POINTS EAST...BRINGING A QUICK 3 INCHES OF RAIN THIS AFTERNOON.
WILL CONTINUE TO MONITOR EASTERN AREAS FOR THE POTENTIAL FOR HEAVY
RAINFALL.
OTHERWISE...ONLY MINOR MODIFICATIONS TO THE GRIDS THIS MORNING.
PREV DISC...
WILL UPDATE TO INPUT LATEST OBSERVED DATA...RESULTING IN
SLOWING DOWN THE ONSET OF RAIN ACROSS THE FCST AREA THIS MORNING.
RAIN HAS MOVED INTO COASTAL AND ADJACENT INTERIOR ZONES BUT HASN`T
PUSHED MUCH FURTHER INLAND AT THIS TIME. STILL EXPECT RAIN TO
SURGE NORTHWARD ACROSS THE FCST AREA TODAY.
THE TRACK OF THE SFC LOW WILL BE ALONG A STALLED FRONT OVER THE
GULF OF MAINE TODAY. THIS WILL SPREAD RAIN ACROSS MUCH OF THE
FORECAST AREA WITH THE HEAVIEST RAIN OVER EASTERN AREAS...WHILE
NEW HAMPSHIRE...ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY SEE
MUCH LESS RAINFALL. TEMPERATURES SHOULDN`T WARM UP TOO MUCH TODAY
DUE TO CLOUDS AND RAIN...WITH THE WARMEST READINGS LIKELY IN NH
ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY. BREEZY NORTH
NORTHEAST WINDS WILL OCCUR TODAY...MORE SO OVER MAINE THAN NH.
GENERALLY USED A BLEND OF GFS/NAM AND MET/MAV MOS GUIDANCE FOR THE
NEAR TERM FCST. USED HPC QPF TO START...THOUGH DID ADJUST
SOMEWHAT. QPF WILL RANGE FROM LESS THAN A QUARTER OF AN INCH
ACROSS THE MAINE MOUNTAINS TO NORTHERN AND WESTERN NH TO AN INCH
TO AN INCH AND A HALF OVER THE MID COAST OF MAINE.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE SFC LOW TRACKS INTO THE MARITIMES TONIGHT BRINGING AN END TO
THE RAIN FROM SOUTHWEST TO NORTHEAST. AREAS OF FOG WILL FORM IN
THE MOIST BOUNDARY LAYER ESPECIALLY FOR AREAS THAT SEE SOME
CLEARING AND HAD A FAIR AMOUNT OF RAINFALL. TOTAL QPF THROUGH
TONIGHT WILL RANGE FROM LESS THAN A QUARTER OF AN INCH ACROSS
NORTHERN AND WESTERN NH TO AROUND TWO INCHES OVER THE MID COAST OF
MAINE WITH SOME HIGHER AMOUNTS POSSIBLE. NOT ANTICIPATING FLOOD
ISSUES WITH THIS EVENT BUT THERE IS THE OUTSIDE CHANCE THAT IF
CLOSER TO 3 /OR MORE/ INCHES OF RAIN FALL THEN THERE MAY BE SOME
MINOR FLOOD PROBLEMS OVER THE MID COAST OF MAINE AND INTO AREAS
JUST TO THE SW...W AND N. AT THIS TIME WILL NOT PUT UP A FLOOD
WATCH. GENERALLY USED A BLEND OF NAM/GFS...MET/MAV MOS AND HPC/RFC
QPF FOR THE SHORT TERM FCST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
WE BEGIN THE PERIOD WITH A SHORTWAVE RIDGE EXITING INTO THE
MARITIMES...AND AN UPPER LOW OVER THE GREAT LAKES SLIDING
EASTWARD INTO NEW ENGLAND. THE UPPER LOW WILL LIFT TO OUR NORTH
AND EAST EARLY NEXT WEEK...WITH A BROAD TROUGH EXTENDING ROM THE
GREAT LAKES INTO NEW ENGLAND IN ITS WAKE. THE UPSHOT OF THIS
PATTERN WILL BE THAT EXCESSIVE HEAT AND HUMIDITY WILL REMAIN WELL
TO OUR SOUTH AND WEST THROUGH THE PERIOD.
IN THE DAILIES...A SLOW-MOVING COLD FRONT APPROACHES FROM THE
GREAT LAKES LATE SUNDAY THEN EXITS THE COAST DURING MONDAY. AN
UPPER LOW WILL PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR
TUESDAY. A WEAK RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY.
ANOTHER DISTURBANCE WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH SATURDAY/...CONDITIONS WILL LOWER WITH
RAIN OVERSPREADING MUCH OF THE REGION TODAY. LOWEST CONDITIONS
OVER MORE EASTERN AND COASTAL AREAS AND HIGHEST CONDITIONS OVER
MORE NORTHERN AND WESTERN AREAS. THUS EXPECT RKD...AUG...PWM AND
PSM TO HAVE LOWEST CIG/VSBY WHILE LEB AND HIE THE HIGHEST CIG/VSBY
WITH CON IN BETWEEN. AS THE RAIN ENDS FROM SW TO NE TONIGHT EXPECT
SOME CLEARING TO FOLLOW BUT THAT WILL ALLOW FOG TO FORM...
ESPECIALLY IN AREAS THAT SEE THE MOST CLEARING BUT ALSO HAD
SIGNIFICANT AMOUNTS OF RAINFALL.
LONG TERM...
SUN PM - MON...MVFR LIKELY IN SHOWERS AND SCT TSTMS.
&&
.MARINE...
SHORT TERM /FRIDAY THROUGH SATURDAY/...WILL UPDATE TO INPUT LATEST
OBSERVED DATA RESULTING IN NO MORE THAN A FEW MINOR ADJUSTMENTS TO
THE PREVIOUS FORECAST. WILL CONTINUE THE SCA FOR THE OUTER WATERS
INTO TONIGHT AS THE SFC LOW MOVES TO THE NE ACROSS THE GULF OF
MAINE TODAY AND INTO THE MARITIMES TONIGHT. EXPECT WIND GUSTS OF
25 KT AND MAYBE EVEN UP TO 30 KT. SEAS WILL BUILD TO 5 OR 6 FT
OVER THE OPEN WATERS. WINDS LET UP AND DROP BELOW SCA LEVELS
TONIGHT. SEAS WILL BE SLOWER TO SUBSIDE AND MAY NOT DROP BELOW SCA
LEVELS UNTIL SATURDAY. HIGH PRESSURE WILL RESULT IN WINDS AND SEAS
BELOW SCA LEVELS ON SATURDAY.
LONG TERM...
SUN NIGHT - MON...WINDS AND SEAS MAY APPROACH SCA THRESHOLD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ150-152-
154.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS GRAY ME
851 AM EDT FRI JUL 26 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE TO THE NORTHEAST ALONG A FRONT ACROSS THE
GULF OF MAINE TODAY AND INTO THE MARITIMES TONIGHT. THIS WILL
PROVIDE RAIN FOR MUCH OF THE REGION INTO TONIGHT WITH THE HEAVIEST
RAIN EXPECTED OVER MORE EASTERN AREAS OF MAINE WHILE NEW HAMPSHIRE
SEES THE LOWEST RAINFALL TOTALS. A WEAK AREA OF HIGH PRESSURE
BUILDS INTO THE REGION ON SATURDAY GIVING US VERY WARM AND DRY
WEATHER. A SLOW-MOVING COLD FRONT WILL APPROACH FROM THE GREAT
LAKES LATE SUNDAY THEN EXIT THE COAST ON MONDAY. AN UPPER LOW WILL
PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR TUESDAY. A WEAK
RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER DISTURBANCE
WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LIGHT RAIN CONTINUES OVER SOUTHERN AREAS PER LATEST OBSERVATIONS
AND RADAR TRENDS. LATEST HRRR RUN SHOWS MAIN BULK OF PCPN RIDING
JUST EAST OF OUR FORECAST AREA...FROM THE PENOBSCOT RIVER VALLEY
AND POINTS EAST...BRINGING A QUICK 3 INCHES OF RAIN THIS AFTERNOON.
OTHERWISE...ONLY MINOR MODIFICATIONS TO THE GRIDS THIS MORNING.
PREV DISC...
WILL UPDATE TO INPUT LATEST OBSERVED DATA...RESULTING IN
SLOWING DOWN THE ONSET OF RAIN ACROSS THE FCST AREA THIS MORNING.
RAIN HAS MOVED INTO COASTAL AND ADJACENT INTERIOR ZONES BUT HASN`T
PUSHED MUCH FURTHER INLAND AT THIS TIME. STILL EXPECT RAIN TO
SURGE NORTHWARD ACROSS THE FCST AREA TODAY.
THE TRACK OF THE SFC LOW WILL BE ALONG A STALLED FRONT OVER THE
GULF OF MAINE TODAY. THIS WILL SPREAD RAIN ACROSS MUCH OF THE
FORECAST AREA WITH THE HEAVIEST RAIN OVER EASTERN AREAS...WHILE
NEW HAMPSHIRE...ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY SEE
MUCH LESS RAINFALL. TEMPERATURES SHOULDN`T WARM UP TOO MUCH TODAY
DUE TO CLOUDS AND RAIN...WITH THE WARMEST READINGS LIKELY IN NH
ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY. BREEZY NORTH
NORTHEAST WINDS WILL OCCUR TODAY...MORE SO OVER MAINE THAN NH.
GENERALLY USED A BLEND OF GFS/NAM AND MET/MAV MOS GUIDANCE FOR THE
NEAR TERM FCST. USED HPC QPF TO START...THOUGH DID ADJUST
SOMEWHAT. QPF WILL RANGE FROM LESS THAN A QUARTER OF AN INCH
ACROSS THE MAINE MOUNTAINS TO NORTHERN AND WESTERN NH TO AN INCH
TO AN INCH AND A HALF OVER THE MID COAST OF MAINE.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE SFC LOW TRACKS INTO THE MARITIMES TONIGHT BRINGING AN END TO
THE RAIN FROM SOUTHWEST TO NORTHEAST. AREAS OF FOG WILL FORM IN
THE MOIST BOUNDARY LAYER ESPECIALLY FOR AREAS THAT SEE SOME
CLEARING AND HAD A FAIR AMOUNT OF RAINFALL. TOTAL QPF THROUGH
TONIGHT WILL RANGE FROM LESS THAN A QUARTER OF AN INCH ACROSS
NORTHERN AND WESTERN NH TO AROUND TWO INCHES OVER THE MID COAST OF
MAINE WITH SOME HIGHER AMOUNTS POSSIBLE. NOT ANTICIPATING FLOOD
ISSUES WITH THIS EVENT BUT THERE IS THE OUTSIDE CHANCE THAT IF
CLOSER TO 3 /OR MORE/ INCHES OF RAIN FALL THEN THERE MAY BE SOME
MINOR FLOOD PROBLEMS OVER THE MID COAST OF MAINE AND INTO AREAS
JUST TO THE SW...W AND N. AT THIS TIME WILL NOT PUT UP A FLOOD
WATCH. GENERALLY USED A BLEND OF NAM/GFS...MET/MAV MOS AND HPC/RFC
QPF FOR THE SHORT TERM FCST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
WE BEGIN THE PERIOD WITH A SHORTWAVE RIDGE EXITING INTO THE
MARITIMES...AND AN UPPER LOW OVER THE GREAT LAKES SLIDING
EASTWARD INTO NEW ENGLAND. THE UPPER LOW WILL LIFT TO OUR NORTH
AND EAST EARLY NEXT WEEK...WITH A BROAD TROUGH EXTENDING ROM THE
GREAT LAKES INTO NEW ENGLAND IN ITS WAKE. THE UPSHOT OF THIS
PATTERN WILL BE THAT EXCESSIVE HEAT AND HUMIDITY WILL REMAIN WELL
TO OUR SOUTH AND WEST THROUGH THE PERIOD.
IN THE DAILIES...A SLOW-MOVING COLD FRONT APPROACHES FROM THE
GREAT LAKES LATE SUNDAY THEN EXITS THE COAST DURING MONDAY. AN
UPPER LOW WILL PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR
TUESDAY. A WEAK RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY.
ANOTHER DISTURBANCE WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH SATURDAY/...CONDITIONS WILL LOWER WITH
RAIN OVERSPREADING MUCH OF THE REGION TODAY. LOWEST CONDITIONS
OVER MORE EASTERN AND COASTAL AREAS AND HIGHEST CONDITIONS OVER
MORE NORTHERN AND WESTERN AREAS. THUS EXPECT RKD...AUG...PWM AND
PSM TO HAVE LOWEST CIG/VSBY WHILE LEB AND HIE THE HIGHEST CIG/VSBY
WITH CON IN BETWEEN. AS THE RAIN ENDS FROM SW TO NE TONIGHT EXPECT
SOME CLEARING TO FOLLOW BUT THAT WILL ALLOW FOG TO FORM...
ESPECIALLY IN AREAS THAT SEE THE MOST CLEARING BUT ALSO HAD
SIGNIFICANT AMOUNTS OF RAINFALL.
LONG TERM...
SUN PM - MON...MVFR LIKELY IN SHOWERS AND SCT TSTMS.
&&
.MARINE...
SHORT TERM /FRIDAY THROUGH SATURDAY/...WILL UPDATE TO INPUT LATEST
OBSERVED DATA RESULTING IN NO MORE THAN A FEW MINOR ADJUSTMENTS TO
THE PREVIOUS FORECAST. WILL CONTINUE THE SCA FOR THE OUTER WATERS
INTO TONIGHT AS THE SFC LOW MOVES TO THE NE ACROSS THE GULF OF
MAINE TODAY AND INTO THE MARITIMES TONIGHT. EXPECT WIND GUSTS OF
25 KT AND MAYBE EVEN UP TO 30 KT. SEAS WILL BUILD TO 5 OR 6 FT
OVER THE OPEN WATERS. WINDS LET UP AND DROP BELOW SCA LEVELS
TONIGHT. SEAS WILL BE SLOWER TO SUBSIDE AND MAY NOT DROP BELOW SCA
LEVELS UNTIL SATURDAY. HIGH PRESSURE WILL RESULT IN WINDS AND SEAS
BELOW SCA LEVELS ON SATURDAY.
LONG TERM...
SUN NIGHT - MON...WINDS AND SEAS MAY APPROACH SCA THRESHOLD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ150-152-
154.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1120 AM EDT FRI JUL 26 2013
LATEST UPDATE...
UPDATE/MARINE
.SYNOPSIS...
ISSUED AT 330 AM EDT FRI JUL 26 2013
ANOTHER SHOT OF COLDER AIR IS HEADED TOWARD LOWER MICHIGAN THIS
WEEKEND. A STRONG COLD FRONT WILL MOVE THROUGH THE AREA BRINGING
SHOWERS AND THUNDERSTORMS AND PERHAPS WATERSPOUTS OVER LAKE
MICHIGAN. HIGH TEMPERATURES IN THE 60S ARE EXPECTED THIS WEEKEND
BEFORE SLOWLY CLIMBING BACK TO THE 80S BY THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1114 AM EDT FRI JUL 26 2013
INCREASED POPS FOR THE AFTERNOON. SATELLITE IMAGERY SHOWS COOLING
CLOUD TOPS AND A BAROCLINIC LEAF IN WISCONSIN ASSOCIATED WITH THE
DEVELOPING WAVE. THIS SYSTEM IS DRAWING IN HIGHER PRECIPITABLE
WATER FROM THE SOUTH WITH VALUES IN MI EXPECTED TO CLIMB UP TO
OVER 1.5 INCHES. THIS IS ABUNDANT MOISTURE FOR THIS AIRMASS. GIVEN
THE FORCING WITH THE WAVE MOVING IN THIS AFTERNOON...THE
PRECIPITATION SHOULD CONTINUE TO GROW.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 330 AM EDT FRI JUL 26 2013
FORECAST CONCERNS DEAL WITH CONVECTIVE TRENDS THROUGH THE PERIOD.
A DEEP UPPER TROUGH WILL ROTATE INTO THE GREAT LAKES THIS WEEKEND.
THE SFC LOW CURRENTLY OVER MINNESOTA WILL MOVE THROUGH LOWER
MICHIGAN SATURDAY MORNING DRAGGING A STRONG COLD FRONT WITH IT.
AHEAD OF THE LOW WE/LL LIKELY SEE SHOWERS AND THUNDERSTORMS DEVELOP.
DECENT DYNAMICS COME TOGETHER THIS AFTERNOON NORTHWEST OF A MUSKEGON
TO CLARE LINE. PRETTY STRONG DPVA COUPLED WITH MUCAPE AROUND 1500
J/KG...A 30 KT LLJ...AND BULK SHEAR NEAR 45 KTS SUGGEST THE
POTENTIAL FOR SOME CONVECTIVE ORGANIZATION. A FEW OF THE STORMS THIS
AFTERNOON COULD BE ON THE STRONG SIDE OVER THE NRN CWA. INVERTED V
SOUNDINGS POINT TOWARD WIND AS THE MAIN THREAT TODAY. AS PWATS CLIMB
TO AN INCH AND A HALF THIS AFTERNOON WE COULD SEE SOME HEAVY
DOWNPOURS TOO.
SHORT RANGE MODELS ARE IN PRETTY GOOD AGREEMENT PUSHING THE COLD
FRONT THROUGH SATURDAY MORNING. WE/LL KEEP THE SHOWERS AND STORMS
GOING THROUGH THE DAY. SATURDAY AFTERNOON COULD SEE A FEW STRONG
STORMS TOO...THIS TIME EAST OF US-127. THE COLD FRONT SHOULD BE IN
THE ERN CWA SATURDAY AFTERNOON. WE/LL HAVE A NARROW WINDOW WHERE
SOME STRONG DYNAMICS COME TOGETHER. MUCAPE AROUND 1500 J/KG/LI/S
NEAR -4C/BULK SHEAR 35-40 KTS WILL BE AIDED BY THE COLD POOL AT H5
MOVING INTO THE AREA.
THE COLD FRONT WILL PUSH THROUGH THE CWA BY LATE SATURDAY.
TEMPERATURES WILL BE WELL BELOW NORMAL SATURDAY AND SUNDAY. GIVEN
LAKE DELTA T/S IN THE UPPER TEENS SATURDAY NIGHT AND SUNDAY LAKE
EFFECT RAIN SHOWERS LOOKS VERY POSSIBLE.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 330 AM EDT FRI JUL 26 2013
THE UNSEASONABLY COLD WEATHER OVER THE WEEKEND WILL COME TO AN END
ON MONDAY AS THE UPPER AIR SYSTEM SUPPORTING IT FINALLY MOVES FAR
ENOUGH EAST. THAT WILL END THE LAKE EFFECT RAIN SHOWERS BY MID TO
LATE MORNING MONDAY. WHAT SHOULD FOLLOW IS AT LEAST 24 HOURS OF NEAR
NORMAL TEMPERATURES WITH NO PRECIPITATION. BEYOND THAT IT IS ANY
ONES GUESS WHAT WILL HAPPEN IN TERMS OF SHOWERS AND THUNDERSTORMS AS
IT IS NOT AT ALL CLEAR JUST HOW FAR SOUTH THE NEXT CANADIAN SYSTEM
CAN DIG SOUTHWARD INTO THE GREAT LAKES.
CURRENTLY THERE IS AN OMEGA BLOCK FROM THE BERING SEA EASTWARD
ACROSS ALASKA. THAT ENTIRE SYSTEM MOVES SLOWLY EAST WITH TIME AND BY
SUNDAY IT WOULD SEEM THE CLOSED UPPER LEVEL LOW JUST EAST OF
KAMCHATKA (WEST SIDE OF THE OMEGA BLOCK) TRIES TO PHASE WITH A
SYSTEM NORTH OF ALASKA. THAT IN TURN PHASES TWO JET STREAKS THAT
THEN DIG SOUTHEAST OVER NORTHWEST CANADA. THAT IN TURN HELPS TO
DEEPEN ANOTHER TROUGH OVER EASTERN NORTH AMERICA. OUR ISSUE IS
JUST HOW DEEP DOES THIS EASTERN TROUGH GET? THE GFS VERSION IS
FLATTER THAN THE ECWMF (SYSTEM STAYS NORTH OF THE GREAT LAKES) BUT
GIVEN THE FREQUENCY WITH WHICH WE HAVE SEEN THESE EASTERN NORTH
AMERICA TROUGHS THIS YEAR DIG INTO THE GREAT LAKES... I HAVE TO
FAVOR THE DEEPER ECMWF ON THIS ONE.
AT THE SAME TIME THERE IS A SOUTHERN STREAM SYSTEM MOVING EAST IN
NEAR ZONAL FLOW EARLY NEXT WEEK. IT WOULD SEEM THAT SYSTEM WOULD
PASS JUST SOUTH OF MICHIGAN TUESDAY THANKS TO THE SHORTWAVE RIDGING
OVER MICHIGAN AT THAT TIME (BETWEEN THE DIGGING CANADIAN SYSTEM
AND THE DEPARTING CLOSED UPPER LOW WHICH WOULD BY THEN BE OVER
QUEBEC). THIS WOULD SUGGEST TO ME OUR BEST CHANCE OF MORE
SHOWERS/THUNDERSTORMS WOULD BE IN THE WEDNESDAY/THURSDAY TIME FRAME.
GIVEN THE HIGHLY QUESTIONABLE NATURE OF THE TIMING AND LOCATION OF
THE NEXT SYSTEM I HAVE LOW POPS WED - THU AND FOR NOW WILL CALL THAT
GOOD. IF NOTHING ELSE IT SHOULD BE NEAR TO ABOVE NORMAL IN
TEMPERATURE DURING THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 754 AM EDT FRI JUL 26 2013
THERE ARE TWO ISSUES WITH THIS FORECAST... FIRST IS THE CONVECTION
TIMING THE SECOND IS WHEN WILL THE CIGS/VSBY FALL OR BELOW VFR?
USING A COMBINATION OF THE GFS...NAM...RAP...HRRR MODELS IT SEEMS
A CONVECTIVE LINE WILL DEVELOP AHEAD OF THE COLD FRONT EARLY AFTERNOON
OVER WISCONSIN AND MOVE EAST TO WESTERN LOWER MICHIGAN NEAR MKG
AROUND 21Z OR SO THEN REACH TO JXN BTWN 03Z AND 06Z. IT ALSO SEEMS
SOME SORT OF WAVE WILL BE FORMING ON THE FRONT SO THE
PRECIPITATION WILL LAST LONGER AT THE MORE EASTERN TAF SITES.
GIVEN THE UNCERTAINTY ON THUNDERSTORMS I PUT VCTS.
AS FOR CIGS.... I USED THE NAM 900 TO 950 MEAN RH AS A PROXY FOR
MVFR CIGS AND THAT COMES IN JUST BEHIND THE SHOWERS (21Z MKG TO
07Z AT JXN). SINCE WINDS BECOME LIGHT NEAR THE COLD FRONT... SEEMS
IFR CIGS WOULD BE LIKELY THEN. HOWEVER THE FRONT DOES NOT GET EAST
OF AZO BEFORE 12Z(BASED ON NAM12 TIMING) SO I KEPT THE WIND FROM
THE SOUTHWEST THROUGH THE NIGHT AT THE EASTER TAF SITES.
&&
.MARINE...
ISSUED AT 1114 AM EDT FRI JUL 26 2013
OMR CAME IN WITH SOME BIGGER WAVES SO WILL KEEP THE BEACH HAZARDS
GOING. HRRR SHOWS WINDS INCREASING OVER THE NEXT FEW HOURS SO
WAVES SHOULD CONTINUE TO BUILD.
&&
.HYDROLOGY...
ISSUED AT 330 AM EDT FRI JUL 26 2013
A HALF TO PERHAPS AN INCH OF RAIN IS POSSIBLE THROUGH SATURDAY. SOME
OF THE THUNDERSTORMS THAT DEVELOP TODAY THROUGH SATURDAY MAY BE
CAPABLE OF PRODUCING HEAVY RAINFALL AND THUS LOCALIZED FLOODING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR MIZ037-043-050-
056-064.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LMZ845>849.
&&
$$
UPDATE...MJS
SYNOPSIS...93
SHORT TERM...93
LONG TERM...WDM
AVIATION...WDM
HYDROLOGY...93
MARINE...MJS
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
630 AM CDT Fri Jul 26 2013
.SHORT TERM...(Today through Sunday Afternoon)
Issued at 359 AM CDT FRI JUL 26 2013
Water vapor imagery this morning shows an upper trough deepening
over northern MN. While this feature is expected to slide southeast
the models have continually shown height falls extending further
south. This will eventually manifest itself in cooler air filtering
further south with time. This system will also maintain northwest
flow into Sunday before finally yielding to rising heights over the
Central Plains and a more zonal look to the h5 heights by late in
the weekend.
Today...What had looked to be a promising morning for rain over most
of the CWA is once again proving to be frustrating, just as it has
all week. Convection has broken into two distinct areas. Scattered
convection over northwest MO is related to the southwest extension
of a band of showers and isolated thunderstorms stretching from
northern IL. Models generally agree that this activity will mainly
affect northern MO. The second area of convection is tied to a MCV
now spinning through east central and southeast KS. The northern
portion of the precipitation shield has shown a slow but steady
decrease in intensity and coverage. Prefer weaker and less coverage
shown by the HRRR solution which favors high PoPs only over the
southwestern counties. In between these two areas of precipitation
will keep low chance PoPs going for possible development later this
morning. Also believe isolated convection could form this afternoon
with whatever convergence is generated as a cold front drops south
through the CWA. Clearing from north to south this afternoon will
allow temperatures to rebound into the lower 80s except for the far
southern counties where clouds/rain will keep readings in the upper
70s.
Tonight...Unseasonably cool high pressure will build southward
through the Plains and MO tonight and provide exceptional sleeping
weather.
Saturday through Sunday...Have had to insert some slight to low
chance PoPs over parts of far west central MO and adjacent eastern
KS as the GFS/NAM/ECMWF are now signaling weak perturbations aloft
embedded within the fickle northwest flow aloft will combine with
weak isentropic ascent and banded frontogenesis to wring out some
light showers/isolated storms. The combo of clouds/precipitation and
the abnormally cool surface high will keep temperatures in the 70s
over the weekend. In addition, overnight temperatures both mornings
may threaten record lows.
.LONG TERM...(Sunday Evening through Thursday)
Issued at 359 AM CDT FRI JUL 26 2013
The first half of next week we`ll see very good chances for much
needed rainfall across the area. The best chances look to arrive
Monday evening into Tuesday morning and especially during the
overnight hours. There are several ingredients that really enhance
our chances. The biggest is that there will be a seasonally strong
low level jet nosing right in the Missouri River valley. Ensemble
data suggest this is about 4 standard deviations stronger than
normal for this time of year. We`ll also continue to see
precipitable water values around 2 inches, which is slightly above
normal for this time of year. Models are also in good agreement with
an area of strong isentropic lift and moisture stability flux nosing
into the area Monday night. All this points to very high POPs for
this stretch of time with the potential for a good amount of
precipitation. I actually feel there is a better chance with this
setup than with the northwest flow pattern from last weekend because
of the strength of the LLJ nosing into the area. This is something
that was lacking last weekend. So fingers crossed, a few inches of
rain would go a long way, at this point, to easing the precipitation
deficits we`ve racked up in June and July so far.
With all the likely cloud cover and possible precipitation,
temperatures on Monday should be well below normal across the entire
area. Highs have a strong potential of staying in the 70s. By
Tuesday afternoon, the bulk of the precipitation should be moving
into eastern Missouri with skies clearing from west to east. So we
should be able to climb back to more normal temperatures across
eastern Kansas and western Missouri by the afternoon. It will be
tougher to get to normal in our east as cloud cover and precip may
linger longer into the day.
The next decent chance for rain may come Friday as we once again are
in a northwest flow pattern with weak waves migrating through the
flow. After last weekend though, I`m a little gun shy about going
very high on POPs. The model consensus was to keep things in the
chance category and that sounds reasonable at this point.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 627 AM CDT FRI JUL 26 2013
Last of the scattered showers over west central MO should exit the
KMKC and KMCI airspace by mid morning. KSTJ should be dry. Could see
a few hours of MVFR cigs with fog, especially KSTJ and KMCI before
winds shift to the north-northwest with passage of a cold front.
Otherwise, VFR conditions with clearing from north to south this
afternoon.
&&
.CLIMATE...
Issued at 359 AM CDT FRI JUL 26 2013
Abnormally cool high pressure will approach record low temperatures
Saturday and Sunday mornings.
July 27 July 28
Min/Year Min/Year
Kansas City 55/1994 52/1994
St. Joseph 47/1971 53/2005
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...CDB
AVIATION...MJ
CLIMATE...MJ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
547 AM CDT FRI JUL 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT FRI JUL 26 2013
SOME PATCHY FOG HAS DEVELOPED ACROSS THE REGION THIS MORNING IN
RESPONSE TO LIGHT WINDS...CLEARING SKIES...ELEVATED DEW POINTS AND A
STRONG INVERSION. EXPECT THIS FOG TO BECOME MORE WIDESPREAD JUST
BEFORE SUNRISE...ESPECIALLY ACROSS SOUTHWESTERN PORTIONS OF THE
FORECAST AREA THAT RECEIVED SOME MODEST RAINFALL AMOUNTS
THURSDAY/THURSDAY NIGHT AND WHERE WINDS REMAIN LIGHT. LATEST
HRRR/SREF PROBS INDICATE THIS FOG SHOULD BE QUICK TO CLEAR JUST
AFTER SUNRISE...WITH MOSTLY SUNNY SKIES EXPECTED ACROSS ALL AREAS
BY 15Z AT THE LATEST. IN FACT...LATEST HRRR IS NOW QUESTIONING ANY
DENSE FOG DEVELOPMENT IN GENERAL.....BUT WITH SEVERAL SITES
FLIRTING WITH 1-5 SM OF VISIBILITY THE PAST COUPLE OF
HOURS...THINK THAT FURTHER DETERIORATION IS STILL POSSIBLE THROUGH
THE REMAINDER OF THE OVERNIGHT/EARLY MORNING HOURS.
IN WAKE OF THE WEAK COLD FRONT THAT MOVED ACROSS THE REGION
OVERNIGHT...EXPECT TEMPERATURES THIS AFTERNOON TO REMAIN ON THE COOL
SIDE OF CLIMATOLOGY...WITH AFTERNOON HIGHS GENERALLY STRUGGLING TO
REACH 80 NORTH OF INTERSTATE 80...WITH LOWER 80S EXPECTED ACROSS THE
REMAINDER OF SOUTH CENTRAL NEBRASKA AS WELL AS NORTH CENTRAL KANSAS.
IN ADDITION TO THE COOL TEMPERATES...CLEARING SKIES WILL ALLOW FOR
GOOD MIXING ACROSS THE REGION THIS AFTERNOON...WITH OCCASIONALLY
GUSTY NORTHERLY WINDS EXPECTED ACROSS THE LOCAL AREA...RESULTING IN
A MOSTLY SUNNY...YET BREEZY AFTERNOON.
LATEST GUIDANCE IS IN GOOD AGREEMENT MAINTAINING NORTHWESTERLY FLOW
ACROSS THE CENTRAL PLAINS THIS AFTERNOON AND EVENING...AS THE LOCAL
AREA REMAINS IN BETWEEN A LARGE AREA OF LOW PRESSURE ACROSS THE GREAT
LAKES REGION AND AN AREA OF HIGH PRESSURE ACROSS THE DESERT
SOUTHWEST. EXPECT THE NEXT UPPER LEVEL DISTURBANCE EMBEDDED IN THIS
NORTHWESTERLY FLOW TO WORK ITS WAY AROUND THE UPPER LEVEL LOW TO OUR
NORTHEAST LATE TONIGHT...WITH A CHANCE OF SHOWERS AND THUNDERSTORMS
RETURNING TO THE LOCAL AREA AFTER 06Z. WITH GOOD MODEL CONSENSUS
HANDLING THIS DISTURBANCE...INCREASED THE CHANCE FOR PRECIPITATION
POST 06Z AS THE AFOREMENTIONED UPPER LEVEL DISTURBANCE APPROACHES
THE LOCAL AREA.
WHILE THE OVERALL AIRMASS IS EXPECTED TO REMAIN COOL ACROSS THE
REGION OVERNIGHT...CLOUDS ASSOCIATED WITH THE APPROACHING
DISTURBANCE MAY HAVE AN IMPACT ON OVERNIGHT LOWS...BUT CONTINUE TO
THINK LOW TEMPERATURES SATURDAY MORNING WILL BOTTOM OUT IN THE LOWER
TO MIDDLE 50S AT MOST LOCATIONS THANKS TO THE EARLY CLEARING AND
COOL AIRMASS IN PLACE...WHICH WILL BE THE COOLEST MORNING
TEMPERATURE READINGS WE HAVE SEEN SINCE THE BEGINNING OF THE MONTH
WHEN GRAND ISLAND...HASTINGS AND KEARNEY ALL REPORTED LOWS OF 52 ON
THE 1ST OF JULY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 AM CDT FRI JUL 26 2013
ALOFT: NW FLOW WILL CONTINUE SAT-SUN ANCHORED BY AN ERN USA TROF AND
A SLOW-MOVING LOW /-3 STANDARD DEVIATIONS FOR LATE JULY/ OVER THE
GREAT LAKES. THE CLOSED LOW /CURRENTLY SEEN IN WV IMAGERY OVER
BRITISH COLUMBIA/ WILL MOVE INLAND SAT-SUN...SPREADING HGT FALLS
OVER THE WRN USA AND TEMPORARILY SUPPRESSING THE SUBTROPICAL HIGH.
THIS WILL CHANGE THE FLOW OVER THE CNTRL PLAINS TO ZONAL MON-TUE BUT
WITH RISING HGTS AS THE NEXT TROF APPROACHES THE W COAST AND ALLOWS
THE SUBTROPICAL HIGH TO EXPAND N OVER THE SRN USA. THIS WILL THEN
MODIFY THE FLOW TO WNW WED-THU.
THIS PATTERN WILL MAINTAIN BELOW NORMAL TEMPS INTO EARLY NEXT WEEK
WITH A GRADUAL UPWARD TREND...RETURNING TO NEAR NORMAL /UPR 80S TO
LOW 90S/.
SFC: THE COOL FRONT MOVING THRU TODAY WILL BECOME PARALLEL TO THE
UPR FLOW /NW-SE/ FROM THE PANHANDLE THRU CNTRL KS. THIS FRONT WILL
REMAIN STATIONARY THRU MON AND THEN DISSIPATE. COOL HIGH PRES WILL
BE OVER THE PLAINS SAT AND DEPART INTO THE ERN USA SUN. THIS HIGH
WILL FILTER COOLER/DRIER AIR INTO THE REGION. ANOTHER COOL FRONT
WILL DROP INTO THE NRN PLAINS TUE. IT REMAINS UNCERTAIN WHEN THIS
FRONT WILL MOVE INTO THE FCST AREA /THU OR FRI?/ BUT IT WILL
EVENTUALLY BECOME STATIONARY.
WITH LWR HGTS IN PLACE OVER THE LAST FEW DAYS...WE SEEM TO HAVE
ENTERED A MORE ACTIVE PATTERN WITH MUCH BETTER POTENTIAL FOR RAIN
THAN THE 7 WEEK PERIOD FROM JUN 1ST THRU JUL 20TH. THIS MORE
FAVORABLE PATTERN APPEARS TO STICK AROUND THE NEXT FEW DAYS.
HAZARDS: MULTIPLE CHANCES FOR TSTMS. WE ARE NOT SEEING ANY SIGNALS
FOR WIDESPREAD SVR TSTMS. HOWEVER...ISOLATED SVR WILL BE
OCCASIONALLY POSSIBLE. THE MAIN TIME PERIOD TO WATCH WILL BE SUN NGT.
THE DAILY DETAILS...
SAT: FGEN-DRIVEN BANDS OF RAIN WILL PROBABLY BE ON-GOING AT DAWN AND
CONTINUE AT LEAST THRU THE MRNG BEFORE ENDING/EXITING TO THE SE.
THIS LOWERS CONFIDENCE IN HIGH TEMPS IF MODELS ARE OFF IN THEIR
LOCATION OF THE CLOUDS/RAIN.
THE ONLY APPRECIABLE INSTABILITY /SEEN IN MUCAPE/ DOESNT APPEAR TO
BE GREAT ENOUGH TO WARRANT A MENTION OF THUNDER. SO IT HAS BEEN
WITHDRAWN FROM THE FCST. MID-LVL LAPSE RATES ARE FCST TO BE MOIST
ADIABATIC.
QPF: MODELS ARE WIDELY DISPERSIVE WITH THEIR AMTS. IT WILL BE
INTERESTING TO SEE HOW THIS PANS OUT. MOST MODELS SUGGESTS .1 TO .33
FOR THIS EVENT...BUT THE 00Z NAM AND EC SUGGEST A SWATH OF .5" IS
POSSIBLE WITH MAX AMTS OF 0.75" OR MORE. THIS ISNT IN THE BAG YET
AND IT WONT BE FOR EVERYWHERE. THE FACT THE THE EC IS ON BOARD LENDS
CREDENCE TO THE NAM. THIS IS JUST ONE RUN FOR EACH. SO LETS SEE HOW
LATER CYCLES EVOLVE.
H8 TEMPS 2 STANDARD DEVIATIONS BELOW NORMAL AND WITH POTENTIAL FOR
CLOUD COVER MUCH OF THE DAY...THERE IS POTENTIAL FOR RECORD COOLEST
HIGH TEMPS ON RECORD /FOR JUL 27TH/ TO BE THREATENED. THE 64 IN 1981
AT GRI SHOULD BE SAFE...BUT THE CURRENT FCST OF 71 WOULD COME IN AS
THE 2ND COOLEST JUL 27TH ON RECORD.
IF THE "WORST" CASE SCENARIO HAPPENS /CLOUDY ALL DAY WITH STEADY
RAIN THRU EARLY AFTN/ THEN WE MAY BE TOO WARM BY 3-5F IN SOME
LOCATIONS AND NOT HIGH ENOUGH ON CLOUD COVER. ALL MODEL 2M TEMP
GUIDANCE EXCEPT GFS SUGGESTS SOME WONT GET OUT OF THE 60S. IT ALL
DEPENDS WHERE THE RAIN SETS UP. AREAS THAT CAN MAINTAIN THE LEAST
AMT OF CLOUDS COULD APPROACH 80F.
SAT NGT: A FEW TSTMS SHOULD ERUPT ALONG AND ON THE IMMEDIATE COOL
SIDE OF THE FRONT...FROM CNTRL KS NW INTO THE PANHANDLE. A 35 KT LLJ
IS FCST TO DEVELOP WITH ITS NOSE OVER NWRN KS. WITH THE ASSOCIATED
ASCENT OVER THE FRONT...THE REMNANTS OF THESE STORMS COULD DRIFT
INTO AREAS S AND W OF THE TRI-CITIES. AT BEST MUCAPE AROUND 500 J/KG
IS FCST AND THIS IS JUST OVER N-CNTRL KS. SO THUNDER HAS BEEN
REMOVED FROM THE FCST OVER S-CNTRL NEB.
SUN: PROBABLY M/CLOUDY WITH SOME PATCHY LGT RAIN OR SPRINKLES. WE DO
HAVE A CHANCE OF SOME STRATIFORM RAIN IN THE FCST...BUT VERTICAL
MOTION IS WEAK. SO CURRENT EXPECTATION IS FOR LOW QPF. MODELS ARE
MAINTAINING A LARGE BATCH OF HIGH MEAN RH IN THE PERSISTENT PRESENCE
OF THE ENTRANCE REGION OF AN 80 KT ULJ. THERE IS ALSO A HINT OF A
SUBTLE VORT MAX /CURRENTLY OVER AZ AND SRN CA/ WHICH ROUNDS THE
SUBTROPICAL HIGH AND ARRIVES HERE SUN-SUN NGT.
STRENGTHENING RETURN FLOW WILL BEGIN TRANSPORTING RICH MSTR BACK
INTO THE REGION...WITH PW CLIMBING BACK ABOVE 1.5 TO 1.75" AND H8
DWPTS TO +15C.
SUN WILL BE ANOTHER DAY OF MUCH BELOW NORMAL DAYTIME TEMPS.
SUN NGT: HIGH RH REMAINS WITH SUBTLE SHRTWV TROF MOVING THRU. MODELS
ARE EMPHATIC IN MCS DEVELOPMENT...BUT CONFIDENCE IS LOW IN EXACTLY
WHERE. MOST MODELS SUGGESTS KS. A MUCH BROADER/STRONGER LLJ IS FCST
/CLOSE TO 50 KTS/. PW IS FCST TO INCREASE TO 1.90" OVER CNTRL-ERN KS.
THIS COULD END UP AN OPPORTUNITY FOR DRENCHING RAINS FOR PARTS OF
THE FCST AREA.
MON: STILL MUCH BELOW NORMAL TEMPS. A LARGE TSTM COMPLEX WILL BE
EXITING THE REGION AND EXPECT GRADUALLY DECREASING CLOUDS.
TUE: LOOKING DRY AND NICE FOR NOW. TEMPS TAKE A BIG JUMP BACK CLOSE
TO NORMAL.
WED: CHANCE OF AFTN-EVNG TSTMS? COVERAGE IS PROBABLY LOW. TEMPS NEAR
NORMAL.
THU: MAYBE BETTER COVERAGE OF AFTN-EVNG TSTMS? TEMPS NEAR NORMAL.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z SATURDAY MORNING)
ISSUED AT 550 AM CDT FRI JUL 26 2013
MVFR VSBYS WILL REMAIN POSSIBLE FOR AN HOUR OR TWO AS PATCHY FOG
HAS DEVELOPED ACROSS THE REGION THIS MORNING. THIS FOG IS VERY
THIN...AND EXPECT IT TO DISSIPATE RAPIDLY AS THE SUN ANGLE
INCREASES BY 13Z OR SO. THEREAFTER...WINDS WILL BECOME THE PRIMARY
FOCUS DURING THE DAYTIME HOURS AS GUSTY NORTHERLY WINDS ARE
ANTICIPATED IN THE WAKE OF LAST NIGHTS FRONT. WINDS WILL
EVENTUALLY RELAX AROUND SUNSET THIS EVENING...WITH AN APPROACHING
DISTURBANCE SPREADING A BROKEN MID LEVEL CLOUD DECK ACROSS THE
REGION OVERNIGHT ALONG WITH THE POTENTIAL FOR A SHRA OR VCTS AT
THE TERMINAL AFT 27/08Z.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SAR
LONG TERM...HALBLAUB
AVIATION...SAR
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1017 AM EDT FRI JUL 26 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA TODAY WILL MOVE OFFSHORE TONIGHT. A
COLD FRONT WILL APPROACH THE REGION SATURDAY...AND WILL CROSS THE
AREA SUNDAY. A LARGE HIGH PRESSURE SYSTEM WILL COVER MUCH OF THE
EASTERN UNITED STATES ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM EDT THURSDAY...
SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT NEARLY
ALL FOG HAS BURNED OFF THIS MORNING...ALTHOUGH A BROKEN CANOPY OF
LOW AND MID CLOUDS CONTINUES TO LINGER ACROSS THE AREA...
PARTICULARLY ALONG THE BLUE RIDGE. RADAR IS CLEAR AT THE MOMENT.
TEMPERATURES CONTINUE TO WARM INTO THE UPPER 60S AND LOW 70S
AFTER LAST NIGHTS SOMEWHAT UNSEASONABLY COOLER TEMPERATURES.
FOR TODAY...EXPECT A REDEVELOPMENT OF ONLY SPOTTY SHOWERS AND
THUNDERSTORMS...MAINLY ALONG THE BLUE RIDGE. STUCK CLOSE TO THE
WRF MODEL SOLUTION COMPARED TO THE RAP MODEL...WHICH APPEARS
OVERDONE ON THE COVERAGE. MAY SEE ONE OR TWO LOCALLY STRONG
THUNDERSTORMS DURING EARLY EVENING...HOWEVER MOST ACTIVITY SHOULD
REMAIN MORE ON THE WEAK SIDE. SHOWERS AND STORMS WILL DIMINISH
ACROSS VIRGINIA AFTER SUNSET...HOWEVER WITH WINDS BECOMING
INCREASINGLY SOUTHWESTERLY AHEAD OF AN APPROACHING COLD
FRONT...WILL LIKELY SEE SHOWERS LINGER INTO EARLY SATURDAY ACROSS
THE MOUNTAINS AND FOOTHILLS OF NORTH CAROLINA.
WITH WINDS BECOMING MORE SOUTHERLY...WILL SEE 850 MB TEMPERATURES
WARM INTO THE +14 TO +16 RANGE BY 00Z/8PM TONIGHT. USED A BLEND OF
MET/MAV GUIDANCE FOR HIGHS TODAY AND LOWS TONIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 400 AM EDT FRIDAY...
DEEP UPPER TROUGH TRAVELS EAST FROM THE GREAT LAKES INTO THE
NORTHEAST DURING THE PERIOD. INITIALLY TRIMMED BACK POPS SATURDAY
MORNING THEN KEPT LIKELY TO CAT POPS SATURDAY AFTERNOON INTO
SATURDAY NIGHT. GFS STILL SHOWED GOOD DYNAMICS WITH DECENT 25-30KT
LLJ/LOW-LEVEL SHEAR INDICATED WITH UPPER DIFFLUENCE PRESENT ACROSS
WESTERN PORTIONS OF THE REGION. LOCALIZED HEAVY RAINFALL WILL ALSO
BE A POSSIBILITY WITH STRONGER THUNDERSTORMS...BUT OVERALL
WIDESPREAD FLOODING NOT EXPECTED. WITH THE MOVEMENT OF THE
SHORTWAVE...SHIFT HIGHER POPS TO THE EAST SATURDAY NIGHT INTO
SUNDAY. DRY AIR PUSHES EAST ACROSS THE REGION ON SUNDAY INTO SUNDAY
NIGHT. UPPER TROUGH SHIFTS EAST OF THE REGION MONDAY. WEAK HIGH
PRESSURE BUILDS ACROSS THE REGION FROM THE OHIO VALLEY. REMOVED THE
MENTION OF THUNDERSTORMS FROM THE EAST AND SOUTH ON MONDAY. THE
COOLER AIRMASS REACHES THE PIEDMONT MONDAY NIGHT WITH LOWS DROPPING
INTO THE LOWER 60S IN SOUTHSIDE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 400 AM EDT FRIDAY...
SLOWED THE RETURN OF MOISTURE TUESDAY BUT ALLOWED FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE
WEST ESPECIALLY ALONG THE SOUTHERN BLUE RIDGE.
AFTER TUESDAY...A MUCH MORE UNSETTLED PATTERN RETURNS. THE
SUBTROPICAL RIDGE AMPLIFIES ACROSS THE CENTRAL/SOUTHERN PLAINS WITH
A ZONAL FLOW NOTED NORTH OF ABOUT 35 DEG LAT ACROSS MUCH OF THE U.S.
AN ALMOST ENDLESS SERIES OF DISTURBANCES TRACK WITHIN THIS ZONAL
FLOW AND IMPINGE ON AN INCREASINGLY WARM/HUMID AIR MASS ACROSS THE
REGION. 850MB TEMPS WILL WARM TOWARD +15 TO +18C BY THE END OF THE
WEEK.
WEDNESDAY APPEARS TO BE THE DAY WITH THE BEST POTENTIAL FOR
WIDESPREAD SHRA/TSRA ACTIVITY. IT APPEARS TO BE MORE OF A RAIN EVENT
THAN A SEVERE THUNDERSTORM EVENT AT THIS POINT AS INSTABILITY IS
MARGINAL. AS WE MOVE TOWARD THE WEEKEND...THERE IS SOME INDICATION
THAT A SERIES OF MCS/THUNDERSTORM COMPLEXES COULD EVOLVE ACROSS THE
MIDWEST/OHIO VALLEY AND SPREAD SE TOWARD OUR REGION. NOTABLE
INSTABILITY IS IN PLACE AT THAT TIME...SO WE WILL CERTAINLY NEED TO
KEEP AN EYE ON THIS INCREASINGLY VOLATILE PATTERN.
TEMPERATURES WILL START OUT WELL BELOW NORMAL...THEN TREND TOWARD
NORMAL FOR THE REMAINDER OF THE WEEK.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 735 AM EDT FRIDAY...
LIFR FOG AT KLWB THIS MORNING. HIGH CONFIDENCE THAT CONDITIONS
WILL IMPROVE TO VFR BY 14Z/10AM.
WINDS REMAIN WEAK TODAY AS HIGH PRESSURE MOVES OFFSHORE. A COLD
FRONT APPROACHES FROM THE WEST TONIGHT. THERE IS A LOW PROBABILITY
OF SHOWERS ALONG THE SOUTHERN APPALACHIANS...AND SOUTH OF KROA AND
KBCB THIS AFTERNOON...BUT TOO LOW OF A CHANCE TO INCLUDE IN THESE
TAFS AT THIS TIME.
SATURDAY THROUGH SATURDAY NIGHT SHOWERS AND THUNDERSTORMS WILL
DEVELOP AHEAD OF THE FRONT. SOME OF THESE STORMS WILL HAVE GUSTY
WINDS AND SUB-VFR CEILINGS AND VISIBILITIES.
ON SUNDAY...THE FRONT WILL CROSS THE AREA WITH MORE SHOWERS AND
THUNDERSTORMS. THERE IS STILL A CHANCE OF LOCALIZED SUB-VFR
CONDITIONS EAST OF THE BLUE RIDGE.
MONDAY INTO TUESDAY...SURFACE HIGH PRESSURE BUILDS OVERHEAD. THIS
WILL YIELD LIGHT WINDS AND LIMITED CLOUD COVER...BUT NIGHTTIME AND
EARLY MORNING FOG AND STRATUS WILL BE POSSIBLE THANKS TO PLENTY OF
BOUNDARY LAYER MOISTURE IN PLACE AFTER THE RAIN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/NF
SHORT TERM...KK
LONG TERM...KK/RAB
AVIATION...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
736 AM EDT FRI JUL 26 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA TODAY WILL MOVE OFFSHORE TONIGHT. A
COLD FRONT WILL APPROACH THE REGION SATURDAY...AND WILL CROSS THE
AREA SUNDAY. A LARGE HIGH PRESSURE SYSTEM WILL COVER MUCH OF THE
EASTERN UNITED STATES ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 420 AM EDT THURSDAY...
ISOLATED SHOWERS HAD DISSIPATED BUT SATELLITE PICTURES AND
SURFACE OBSERVATIONS SHOWED STRATOCUMULUS...MAINLY EAST OF THE
BLUE RIDGE AND PATCHY FOG IN THE VIRGINIA AND NORTH CAROLINA
FOOTHILLS. MORE WIDESPREAD FOG WAS DEVELOPING OVER WEST VIRGINIA.
00Z LOCAL WRF...LATEST RUC MODELS AND HUMIDITY FORECASTS FROM THE
NAM AD GFS ALL KEEP DEEPER MOISTURE AND BEST PROBABILITY OF
PRECIPITATION ALONG THE SOUTHERN BLUE RIDGE THIS AFTERNOON.
HIGH PRESSURE OVER THE FORECAST AREA THIS MORNING WILL MOVE EAST
THEN OFFSHORE BY THIS EVENING. WINDS WILL BE LIGHT THIS MORNING
THEN BECOME SOUTHEAST THIS AFTERNOON WHICH WILL HELP LIFT ALONG
THE BLUE RIDGE.
UPPER LOW DEVELOPING OVER THE WESTERN GREAT LAKES WILL BRING A
FRONT INTO THE OHIO VALLEY BY LATE TONIGHT. SURFACE FRONT EXPECTED
TO BE FROM EASTERN MICHIGAN TO SOUTHEAST MISSOURI...WELL WEST OF
THE FORECAST AREA. HAVE LOWERED THE CHANCE OF RAIN AFTER 06A/2AM.
850 MB TEMPERATURES WARM INTO THE +14 TO +16 RANGE BY 00Z/8PM
TONIGHT. USED A BLEND OF MET/MAV GUIDANCE FOR HIGHS TODAY AND LOWS
TONIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 400 AM EDT FRIDAY...
DEEP UPPER TROUGH TRAVELS EAST FROM THE GREAT LAKES INTO THE
NORTHEAST DURING THE PERIOD. INITIALLY TRIMMED BACK POPS SATURDAY
MORNING THEN KEPT LIKELY TO CAT POPS SATURDAY AFTERNOON INTO
SATURDAY NIGHT. GFS STILL SHOWED GOOD DYNAMICS WITH DECENT 25-30KT
LLJ/LOW-LEVEL SHEAR INDICATED WITH UPPER DIFFLUENCE PRESENT ACROSS
WESTERN PORTIONS OF THE REGION. LOCALIZED HEAVY RAINFALL WILL ALSO
BE A POSSIBILITY WITH STRONGER THUNDERSTORMS...BUT OVERALL
WIDESPREAD FLOODING NOT EXPECTED. WITH THE MOVEMENT OF THE
SHORTWAVE...SHIFT HIGHER POPS TO THE EAST SATURDAY NIGHT INTO
SUNDAY. DRY AIR PUSHES EAST ACROSS THE REGION ON SUNDAY INTO SUNDAY
NIGHT. UPPER TROUGH SHIFTS EAST OF THE REGION MONDAY. WEAK HIGH
PRESSURE BUILDS ACROSS THE REGION FROM THE OHIO VALLEY. REMOVED THE
MENTION OF THUNDERSTORMS FROM THE EAST AND SOUTH ON MONDAY. THE
COOLER AIRMASS REACHES THE PIEDMONT MONDAY NIGHT WITH LOWS DROPPING
INTO THE LOWER 60S IN SOUTHSIDE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 400 AM EDT FRIDAY...
SLOWED THE RETURN OF MOISTURE TUESDAY BUT ALLOWED FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE
WEST ESPECIALLY ALONG THE SOUTHERN BLUE RIDGE.
AFTER TUESDAY...A MUCH MORE UNSETTLED PATTERN RETURNS. THE
SUBTROPICAL RIDGE AMPLIFIES ACROSS THE CENTRAL/SOUTHERN PLAINS WITH
A ZONAL FLOW NOTED NORTH OF ABOUT 35 DEG LAT ACROSS MUCH OF THE U.S.
AN ALMOST ENDLESS SERIES OF DISTURBANCES TRACK WITHIN THIS ZONAL
FLOW AND IMPINGE ON AN INCREASINGLY WARM/HUMID AIR MASS ACROSS THE
REGION. 850MB TEMPS WILL WARM TOWARD +15 TO +18C BY THE END OF THE
WEEK.
WEDNESDAY APPEARS TO BE THE DAY WITH THE BEST POTENTIAL FOR
WIDESPREAD SHRA/TSRA ACTIVITY. IT APPEARS TO BE MORE OF A RAIN EVENT
THAN A SEVERE THUNDERSTORM EVENT AT THIS POINT AS INSTABILITY IS
MARGINAL. AS WE MOVE TOWARD THE WEEKEND...THERE IS SOME INDICATION
THAT A SERIES OF MCS/THUNDERSTORM COMPLEXES COULD EVOLVE ACROSS THE
MIDWEST/OHIO VALLEY AND SPREAD SE TOWARD OUR REGION. NOTABLE
INSTABILITY IS IN PLACE AT THAT TIME...SO WE WILL CERTAINLY NEED TO
KEEP AN EYE ON THIS INCREASINGLY VOLATILE PATTERN.
TEMPERATURES WILL START OUT WELL BELOW NORMAL...THEN TREND TOWARD
NORMAL FOR THE REMAINDER OF THE WEEK.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 735 AM EDT FRIDAY...
LIFR FOG AT KLWB THIS MORNING. HIGH CONFIDENCE THAT CONDITIONS
WILL IMPROVE TO VFR BY 14Z/10AM.
WINDS REMAIN WEAK TODAY AS HIGH PRESSURE MOVES OFFSHORE. A COLD
FRONT APPROACHES FROM THE WEST TONIGHT. THERE IS A LOW PROBABILITY
OF SHOWERS ALONG THE SOUTHERN APPALACHIANS...AND SOUTH OF KROA AND
KBCB THIS AFTERNOON...BUT TOO LOW OF A CHANCE TO INCLUDE IN THESE
TAFS AT THIS TIME.
SATURDAY THROUGH SATURDAY NIGHT SHOWERS AND THUNDERSTORMS WILL
DEVELOP AHEAD OF THE FRONT. SOME OF THESE STORMS WILL HAVE GUSTY
WINDS AND SUB-VFR CEILINGS AND VISIBILITIES.
ON SUNDAY...THE FRONT WILL CROSS THE AREA WITH MORE SHOWERS AND
THUNDERSTORMS. THERE IS STILL A CHANCE OF LOCALIZED SUB-VFR
CONDITIONS EAST OF THE BLUE RIDGE.
MONDAY INTO TUESDAY...SURFACE HIGH PRESSURE BUILDS OVERHEAD. THIS
WILL YIELD LIGHT WINDS AND LIMITED CLOUD COVER...BUT NIGHTTIME AND
EARLY MORNING FOG AND STRATUS WILL BE POSSIBLE THANKS TO PLENTY OF
BOUNDARY LAYER MOISTURE IN PLACE AFTER THE RAIN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KK
LONG TERM...KK/RAB
AVIATION...AMS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1057 AM CDT FRI JUL 26 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 1055 AM CDT FRI JUL 26 2013
SHOWER AND THUNDERSTORM ACTIVITY HAS BECOME SOMEWHAT MORE
WIDESPREAD LATE THIS MORNING OVER CENTRAL AND NORTHEAST WISCONSIN
AHEAD OF APPROACHING COLD FRONT AND MAIN SHORTWAVE TROUGH.
FORTUNATELY CLOUDS HAVE BEEN STUBBORN THIS MORNING WITH LITTLE IN
THE WAY OF ANY BREAKS TO HELP DESTABLIZE ATMOSPHERE FURTHER. TEMPS
HAVE BEEN SLOWLY RISING INTO THE UPPER 60S TO AROUND 70. STORMS
OVER CENTRAL WISCONSIN ARE SLOWLY STRENGTHENING BUT SO FAR NO
SIGNIFICANT WEATHER OTHER THAN LOCALLY BREIF HEAVY RAINFALL.
LATEST HRRR SEEMS TO HAVE A BASIC HANDLE ON THE ONGOING ACTIVITY
OVER CENTRAL WISCOSNIN TAKING IT INTO NORTHERN WISCOSNIN BY EARLY
AFTERNOON AND WEAKENING IT SOME. HRRR ALSO CONTINUES TO SUGGEST
PERHAPS SOME ADDITIONAL DEVELOPMENT OVER SOUTHCENRAL WISCONSIN
WHICH IT THEN FORECASTS TO MOVE INTO THE FOX VALLEY BY 3 OR 4 PM.
WILL CONTINUE TO MONITOR RADAR TRENDS.
GRB RADAR HAS BEEN UNSTABLE LAST 24 HOURS OR SO...THUS HAD TO BE
TAKEN DOWN FOR SOME MAINTENANCE UNTIL ABOUT 2 PM...THUS RELYING
ON SURROUNDING RADARS.
EB
&&
.SHORT TERM...TODAY...TONIGHT...AND SATURDAY
ISSUED AT 317 AM CDT FRI JUL 26 2013
AT 08Z...COLD FRONT EXTENDED FROM NORTHWEST WISCONSIN INTO SOUTH CENTRAL
MINNESOTA AND NORTH-CENTRAL IOWA. THE COLD FRONT IS EXPECTED TO ADVANCE
EASTWARD INTO NORTHEAST WISCONSIN THIS AFTERNOON. SINCE CONVECTION
WAS NOT AS WIDESPREAD AS THE MODELS DEPICTED...THERE IS A WINDOW
OF OPPORTUNITY FOR SOME STORMS TO BECOME STRONG OR SEVERE AROUND
MID DAY INTO THE AFTERNOON HOURS ACROSS CENTRAL AND NORTHEAST
WISCONSIN. MODIFIED SOUNDINGS OFF THE WRF MODEL USING TEMP OF 75 AND
DEW POINT OF 61 GAVE ME AROUND 1500 J/KG...WINDEX VALUES OF 40 TO
45 KNOTS AND WET BULB HEIGHTS BETWEEN TEN AND ELEVEN THOUSAND FEET.
LOCALLY HEAVY RAIN IS ALSO POSSIBLE. PER COORDINATION WITH SPC...DAY
1 OUTLOOK HAS PORTIONS OF CENTRAL AND NORTHEAST WISCONSIN IN THE
SLIGHT RISK. IT WILL ALL DEPEND ON HOW MUCH SUNSHINE WE GET THIS
MORNING...AND IF EARLY MORNING CONVECTION SHOULD MESS UP EXPECTED
CONVECTION LATER THIS MORNING AND THIS AFTERNOON.
IMPRESSIVE UPPER LOW EXPECTED TO SWING ACROSS THE REGION LATER
TONIGHT AND SATURDAY. PLENTY OF MOISTURE IN THE LOW LEVELS OF THE
SOUNDINGS TO CAUSE SHOWERS AND ISOLATED THUNDERSTORMS TO SPREAD
SOUTHEAST ACROSS THE AREA LATER FRIDAY NIGHT AND SATURDAY. HAVE INCREASED
POPS CONSIDERABLY FROM PREVIOUS FORECAST PACKAGE WHICH WAS IN LINE
WITH THE 00Z MET/MAV GUIDANCE TONIGHT.
THE BIG CHANGE WILL BE THE UNSEASONABLY COOL AIR. CAN NOT STOMACH
HIGHS IN THE 50S AT THE END OF JULY. WITH CLOUD COVER AND SHOWERS
AROUND...THIS SEEMS REASONABLE ACROSS THE NORTH. TEMPERATURES
ACROSS THE SOUTH WILL BE A LITTLE BIT WARMER WITH HIGHS IN THE
LOWER TO MIDDLE 60S WITH A FEW MORE BREAKS IN THE CLOUDS EXPECTED.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY
ISSUED AT 317 AM CDT FRI JUL 26 2013
THE PESKY CLOSED UPR LOW OVER THE GREAT LAKES WL FINALLY LIFT NE
EARLY NEXT WEEK...HOWEVER A GENERAL TROFFINESS IS EXPECTED TO
REMAIN OVER THE ERN HALF OF CANADA/NE QUARTER OF THE CONUS NEXT
WEEK. THIS W-NW FLOW ALOFT WL INITIALLY KEEP TEMPS BELOW NORMAL
WITH ONLY A SLIGHT MODERATION LATE IN THE FCST PERIOD. PCPN CHCS
MAINLY TIED TO THE PASSAGE OF A FRONTAL BOUNDARY TUE INTO WED.
UPR LOW TO CONT SPINNING AROUND UPR MI/NRN LAKE MI SAT NGT WITH
ANY INSTABILITY SHWRS/TSTMS DISSIPATING DURING THE EVENING AS
DAYTIME HEATING WANES. THAT BEING SAID...WOULD NOT BE SURPRISED
TO SEE A FEW SHWRS LINGER THRU THE NGT AS A CYCLONIC FLOW REMAINS
OVER THE REGION. THE PROXIMITY OF THIS UPR LOW WL KEEP SOME
GRADIENT WINDS THRU THE NGT AND WHEN COUPLED WITH A DECENT AMOUNT
OF CLOUDS...MIN TEMPS SHOULD BE HELD UP DESPITE THE COOL AIR
OVERHEAD. LOOK FOR READINGS TO RANGE FROM THE LWR 40S TO LWR 50S.
THE UPR LOW FINALLY BEGINS A NE DRIFT ON SUNDAY IN RESPONSE TO
RISING UPR HEIGHTS ACROSS THE NRN PLAINS. AIR MASS OVER WI WL NOT
BE AS COLD ALOFT COMPARED TO SAT...HOWEVER WOULD EXPECT AT LEAST A
SLGT CHC OF MAINLY AFTERNOON SHWRS AS SFC TEMPS WARM. EXPECT MAX
TEMPS TO BE ALMOST 5 DEGS WARMER THAN SAT WHICH WOULD PLACE
READINGS IN THE LWR TO MID 60S NORTH...MID TO UPR 60S
CNTRL/E-CNTRL WI.
GRADUALLY IMPROVING CONDITIONS ARE EXPECTED OVER NE WI SUNDAY NGT
AS THE UPR LOW SLOWLY PULLS AWAY AND A WEAK AREA OF HI PRES MOVES
IN. BOUNDARY LAYER WINDS BEGIN TO EASE OVRNGT AND WITH SKIES
BECOMING AT LEAST PARTLY CLOUDY...TEMPS COULD FALL MORE THAN
ANTICIPATED. HAVE LEANED TOWARD THE COOLER SIDE OF GUIDANCE WHICH
GIVES MID TO UPR 40S NORTH...LWR 50S E-CNTRL WI. A PLEASANT DAY ON
TAP ON MON AS THE SFC HI TO RESIDE OVER THE GREAT LAKES. UNDER
MOSTLY SUNNY SKIES WITH LIGHT WINDS...TEMPS SHOULD BE ABLE TO MAKE
AN APPRECIABLE JUMP UP WITH MAX TEMPS AT LEAST BACK INTO THE 70S.
THE MEAN FLOW TO BE QUASI-ZONAL ACROSS THE NRN TIER OF STATES
EARLY NEXT WEEK WITH THE MDLS INDICATING THE FIRST OF A SERIES OF
PACIFIC SYSTEMS QUICKLY MOVING ACROSS THE CONUS. THE FIRST PART OF
THIS SYSTEM TO BE PRIMARY WAA RETURNING TO THE REGION AS 8H TEMPS
TO RISE INTO THE LWR TEENS CELSIUS ON TUE. THE PLUS SIDE HERE IS
WARMER TEMPS RETURNING WITH MAX READINGS IN THE MID TO UPR 70S.
THE SECOND PART OF THIS SYSTEM ARRIVES TUE NGT IN THE FORM OF AN
ADVANCING CDFNT WHICH IS PROGGED TO REACH NE WI BY 12Z WED. THERE
ARE MDL TIMING DIFFERENCES WITH REGARDS TO THE FORWARD SPEED OF
THIS FRONTAL BOUNDARY...SO HARD TO DETERMINE WHERE TO HIT THE POPS
THE HARDEST. IN FACT...IF THE CDFNT SLOWS DOWN MUCH AT ALL...THE
BETTER PCPN CHCS MAY HOLD OFF TIL WED. HAVE RAISED POPS A BIT FOR
BOTH TUE NGT AND WED WITH THIS FNT IN OUR VICINITY.
FCST AT THE END OF THE LONG-TERM HAS PLENTY OF DOUBT AS THE MDLS
ARE STRUGGLING WITH THE HANDLING OF THE NEXT PACIFIC SYSTEM MOVING
INTO THE CNTRL CONUS. SUCH A WIDE SPREAD OF SOLUTIONS FAVORS A
CONSENSUS SOLUTION WHICH PROVIDES A SLGT CHC POP.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 614 AM CDT FRI JUL 26 2013
SOME LIGHT SHOWERS WERE OCCURRING NORTH OF KGRB AT 11Z THIS MORNING.
SKY COVER VARIED FROM VFR TO MVFR ACROSS MUCH OF THE REGION. THE
ONLY EXCEPTION WAS ACROSS THE FAR NORTH WHERE SOME IFR CIGS WERE
REPORTED ACROSS VILAS COUNTY (KARV/KEGV). COLD FRONT WILL MOVE
ACROSS THE REGION TODAY. EXPECT AN INCREASE IN SHOWER AND THUNDERSTORM
ACTIVITY LATER THIS MORNING AND THIS AFTERNOON...ESPECIALLY ACROSS
CENTRAL AND NORTHEAST WISCONSIN. SOME OF THE STORMS MAY CONTAIN LARGE
HAIL AND DAMAGING WINDS. SHOWERS AND STORMS SHOULD WANE OR END LATER
THIS AFTERNOON AND THIS EVENING. AN USUAL UPPER LOW WILL DROP INTO
THE WESTERN GREAT LAKES LATER TONIGHT AND SATURDAY...BRING UNSEASONABLY
COOL CONDITIONS ALONG WITH A CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS
ON SATURDAY.
&&
.MARINE...
ISSUED AT 317 AM CDT FRI JUL 26 2013
EXTENDED SMALL CRAFT ADVISORY UNTIL MID AFTERNOON DUE TO SOUTHERLY
FETCH UP THE LENGTH OF LAKE MICHIGAN. WINDS WILL SLACKEN AND VEER
TO THE WEST LATE THIS AFTERNOON. AN USUAL JULY UPPER LOW MOVING
ACROSS THE GREAT LAKES REGION WILL BRING A CHANCE OF WATER SPOUTS
ON LAKE MICHIGAN ON SUNDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........ESB
SHORT TERM.....ECKBERG
LONG TERM......KALLAS
AVIATION.......ECKBERG
MARINE.........ECKBERG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
605 AM CDT FRI JUL 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT FRI JUL 26 2013
THE MAIN FOCUS FOR TODAY IS ON THE PASSING COLD FRONT AND THE
CHANCES FOR CONVECTION ALONG IT.
CURRENTLY...THE FIRST IN A SERIES OF MID LEVEL SHORT WAVE TROUGHS
IN FAR SOUTHERN ONTARIO IS PROPAGATING EAST ALONG THE SOUTHERN
PERIPHERY OF A BROADER TROUGH THAT IS IN PLACE ACROSS MUCH OF
SOUTHEASTERN CANADA. THIS LEAD SHORTWAVE HAS BEEN GRADUALLY
WEAKENING AHEAD OF THE MAIN VORT MAX PER THE LATEST WATER VAPOR IR
IMAGERY AND BECOMING MORE EAST TO WEST ORIENTED ACROSS NORTH
CENTRAL WISCONSIN. THIS FEATURE HAS HELPED TO KEEP A BAND OF
SHOWERS/STORMS GOING ACROSS THIS REGION EARLY THIS MORNING.
DOWN AT THE SURFACE...A BROAD AREA OF LOW PRESSURE IS IN PLACE
FROM LAKE SUPERIOR WEST INTO NORTHERN MINNESOTA WITH A COLD FRONT
DROPPING SOUTH THROUGH EASTERN/SOUTH CENTRAL MINNESOTA ON INTO
NORTHWEST IOWA. 26.07Z RAP ANALYSIS SHOWS AN INSTABILITY AXIS OF
500-1000 J/KG OF 0-3KM MUCAPE IN PLACE AHEAD OF THIS FRONT FROM
NORTHWEST IOWA INTO NORTH CENTRAL WISCONSIN. THIS COMBINATION OF
THE FRONT AND INSTABILITY HAS BEEN ENOUGH TO FUEL SOME SCATTERED
CONVECTION ACROSS MINNESOTA EARLY THIS MORNING.
ALL INDICATIONS ARE THAT THE TROUGH/FRONT ARE GOING TO PASS
THROUGH RATHER QUICKLY TODAY AS THIS MAIN MID LEVEL TROUGH WRAPS
UP. THERE DOES APPEAR TO BE A BRIEF WINDOW FOR THE DEVELOPMENT OF
SEVERE THUNDERSTORMS IN WESTERN WISCONSIN LATER THIS MORNING AND
INTO THE EARLY AFTERNOON AS INSTABILITY BUILDS INTO THE
1000-1500J/KG RANGE AND A 500MB JET STREAK PUSHES INTO CENTRAL
WISCONSIN. MUCH OF THE 26.00Z TO 26.06Z MESO-GUIDANCE SUGGESTS
THAT THE COLD FRONT IS ALREADY GOING TO BE INTO CENTRAL WISCONSIN
BY 17-19Z WITH ANY SEVERE POTENTIAL COMING AHEAD OF THIS FRONT. AM
NOT EXPECTING A WIDESPREAD SEVERE OUTBREAK BY ANY MEANS...BUT THE
INCREASING INSTABILITY AND INCREASING MID LEVEL WINDS WILL HELP TO
ORGANIZE A FEW UPDRAFTS AND SHOULD PRODUCE A FEW SEVERE STORMS
WITH LARGE HAIL THE MAIN HAZARD DUE TO THE LOW FREEZING LEVELS.
THE HIGHER SEVERE CHANCES WILL BE INTO CENTRAL/EASTERN WISCONSIN
WHERE THERE WILL BE A LONGER PERIOD OF WARMING BEFORE THE STORMS
GET IN.
AS THE CORE OF THE MID LEVEL TROUGH TRACKS THROUGH THIS
AFTERNOON...A SECONDARY COLD FRONT/TROUGH WILL DROP SOUTH ACROSS
THE REGION AND COULD BE A FOCUS FOR SOME SHOWER DEVELOPMENT. WINDS
WILL PICK UP AND TEMPERATURES WILL DROP BEHIND BOTH FRONTS TO MARK
THE BEGINNING OF AN UNSEASONABLY COOL PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI JUL 26 2013
THE FOCUS THEN SHIFTS TO HOW COLD IT WILL BE THIS WEEKEND AS AN
ANOMALOUSLY COOL AIR MASS GETS PULLED DOWN INTO THE REGION FROM
NORTH CENTRAL CANADA. THE 26.00Z NAM/GFS/ECMWF 850MB TEMPERATURE
ANOMALIES AT -1.5 TO -2.5 DEVIATIONS FROM THE NORM WHICH TYPICALLY
INDICATE NEAR RECORD TO RECORD COLD TEMPERATURES. WITH QUESTIONS
IN THE AMOUNT OF CLOUD COVER LINGERING...HAVE NOT GONE BELOW
RECORD LOWS OR RECORD LOW MAXIMUM TEMPERATURES BUT HAVE KEPT THEM
CLOSE. AT LSE...THE RECORD LOW HIGH FOR SATURDAY IS 69 AND FOR
SUNDAY IS 66 WHILE THE RECORD LOWS ARE 48 ON SATURDAY/50 ON
SUNDAY. AT RST...THE LOW MAX FOR SATURDAY IS 64/SUNDAY IS 63 WHILE
THE RECORD LOW IS 47 ON BOTH SATURDAY AND SUNDAY. 26.00Z FORECAST
SOUNDINGS SHOW SOME INSTABILITY DEVELOPING IN THE AFTERNOON TO
WHERE SOME DIURNALLY DRIVEN SHOWERS SHOULD DEVELOP...PARTICULARLY
IN WESTERN WISCONSIN WHICH WILL BE CLOSER TO THE UPPER LEVEL
TROUGH.
AS THE MID LEVEL LOW WOBBLES EASTWARD INTO THE EARLY PORTION OF
NEXT WEEK...THE NEXT MID LEVEL TROUGH...WHICH IS CURRENTLY IN FAR
SOUTHWEST CANADA...WILL TRACK EAST ACROSS CANADA. INSTABILITY WILL
BE ON THE INCREASE ON THE WESTERN PERIPHERY OF THE SURFACE RIDGE
WITH SOME SMALL CHANCES FOR CONVECTION MONDAY NIGHT THROUGH
THURSDAY. NOT OVERLY CONFIDENT THAT ALL OF THESE PRECIPITATION
CHANCES ARE NEEDED...BUT WITH THE LINGERING TROUGH NEARBY CAN NOT
RULE THEM OUT. A GRADUAL WARMING TREND IS EXPECTED WITH 850MB
TEMPERATURES RISING FROM +4C ON SATURDAY TO +13C BY TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 605 AM CDT FRI JUL 26 2013
A COLD FRONT WILL MOVE THROUGH THE AREA THIS MORNING. PLAN ON
SCATTERED SHRA ACTIVITY TO ACCOMPANY THE FRONTAL PASSAGE. LOOK FOR ANY
THUNDERSTORM CHANCES TO TAKE PLACE FARTHER EAST/SOUTHEAST OF THE
KRST/KLSE TAF SITES...ACROSS CENTRAL INTO FAR SOUTHWEST WI. BEHIND
THE FRONTAL PASSAGE...GUSTY NORTHWEST WINDS IN THE 15 TO 25KT
RANGE WILL TAKE PLACE. ALSO...LOOK FOR THE MVFR/IFR CLOUD TO SCATTER
BEHIND THE FRONTAL PASSAGE. KEPT A VCSH MENTION IN AT KLSE AS A
SECONDARY COLD FRONT DROPS THROUGH THE REGION LATER THIS
AFTERNOON. PLAN ON VFR CONDITIONS TONIGHT AS DRIER/COOLER AIR
FILTERS INTO THE AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
220 PM PDT FRI JUL 26 2013
.SYNOPSIS...
MOIST TROPICAL AIR WILL CONTINUE OVER SOUTHERN CALIFORNIA THROUGH
SATURDAY. THE AIR MASS IS UNSTABLE ENOUGH FOR WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS AT ANY TIME. RAINFALL AMOUNTS AND RAINFALL
RATES MAY BE HEAVY. A FLASH FLOOD WATCH IS IN EFFECT THROUGH 8 PM
THIS EVENING...AND MAY BE EXTENDED. ON SUNDAY AND MONDAY...A WEAK
TROUGH OF LOW PRESSURE MOVES INLAND TO THE NORTH. THIS WILL BRING
DRIER AND MORE STABLE AIR ACROSS THE REGION...BUT ALSO DEEPEN THE
MARINE LAYER.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.REMAINDER THIS AFTERNOON THROUGH SATURDAY...
AS MENTIONED IN THE MID MORNING DISCUSSION...THE AIR MASS IS RAPIDLY
SATURATING. INTERNET ACCESS HAS BEEN SPOTTY AND EXTREMELY SLOW
TODAY...ADDING ANOTHER VARIABLE TO SOLVING THE FORECAST PROBLEM.
CONSENSUS IS THAT A SUBSIDENCE CAP FORMED IN THE WAKE OF THE
EASTERLY WAVE THAT PASSED THROUGH THIS MORNING...BUT ENOUGH HEATING
AND CLEARING LEFT THIS AFTERNOON TO OVERCOME THIS AND ALLOW
THUNDERSTORMS TO 45000 FT TO DEVELOP. THE MOST RECENT GPS MET
INTEGRATED PRECIPITABLE WATER SENSORS NOW SHOW A RANGE OF VALUES
FROM 1.5 INCHES ON THE COAST TO 2.2 INCHES OVER THE COACHELLA
VALLEY/ANZA BORREGO DESERT. 20Z RUC MODEL POINT SOUNDINGS SHOW
TRANSPORT WINDS DROPPING BELOW 15 MPH BETWEEN NOW AND 1700 PDT. WITH
A TROPICAL AIR MASS...CLIMATOLOGY WOULD FAVOR NOCTURNAL THUNDERSTORM
AS WELL AS THOSE GENERATED BY SURFACE CONVERGENCE AND DAYTIME
HEATING. AS FOR SATURDAY OVERALL SYNOPTIC AND EVEN MESOSCALE PATTERN
DOES NOT LOOK A LOT DIFFERENT THAN TODAY. THE VEERING OF THE GENERAL
WINDS FLOW FROM SOUTH TO SOUTHWEST IS THE ONLY DAMPENING EFFECT AND
UNLESS THE TRANSPORT WINDS ARE IN EXCESS OF 10 MPH...CANNOT RULE OUT
THUNDERSTORMS. MAY NEED TO EXTEND OR REISSUE THE FLASH FLOOD WATCH
BEYOND 8 PM THIS EVENING. DID SOME TWEAKING TO THE POPS/QPF GRIDS TO
BRING THEM MORE IN LINE WITH SHORT RANGE ENSEMBLE FORECAST
GUIDANCE...THESE STILL MAY BE NOT HIGH ENOUGH...ESPECIALLY WITH
SLOWER MOVING CELLS AND ANY TRAINING OF CELLS THAT MIGHT OCCUR ALONG
SLOW MOVING CONVERGENCE ZONES. KEPT THE TREND OF LOWER POPS/COVERAGE
FOR SATURDAY.
.SUNDAY THROUGH NEXT FRIDAY...
THE GENERAL AND PREVAILING WIND FLOW IS SOUTHWEST. THE LOW/TROUGH
OFF THE COAST DOES NOT COMPLETELY GO AWAY AND SOME MODELS INDICATE
IT MAY SPIN BACK UP INTO A CLOSED LOW AND DRIFT SOUTHWEST. IF THAT
MATERIALIZES THEN WE ARE BACK INTO A MONSOON FLOW PATTERN BY MIDDLE
OF NEXT WEEK. NOT CERTAIN IF THE LONGER RANGE GUIDANCE...7-45 DAYS
SUPPORTS THIS...BUT WE HAVE HAD SUMMERS IN THE RECENT PAST THAT ONCE
THE MONSOON SEASON STARTS...THE SURGES OF TROPICAL AIR MOVING ACROSS
SOUTHWEST CALIFORNIA DO NOT END UNTIL SEPTEMBER. FOR NOW THE
FORECAST IS BASED ON GRADUAL WARMING AND DRYING SUNDAY THROUGH
FRIDAY.
&&
.AVIATION...
261905Z...COAST/VALLEYS...PATCHY LOW STRATUS WILL CONTINUE ALONG THE
COASTAL STRIP THROUGH THIS EVENING WITH BASES 1K-1.3K FT MSL AND
TOPS 1.5-2K FT MSL. A DEEP MONSOONAL FLOW OF MID-LEVEL MOISTURE WILL
CONTINUE BKN CIGS AOA FL100 WITH LYRS TO FL250...CLEARING FROM KSAN
TO KSNA BEGINNING AROUND 00Z THROUGH 08Z TONIGHT.
500-700 FT THICK STRATUS LAYER WITH BASES NEAR 1K FT MSL EXPECTED TO
MOVE BACK INLAND AFT 01Z SAT AND EXTEND 15-20SM INLAND THROUGH 12Z
SAT...BUT CONFIDENCE LOW ON ARRIVAL AT INDIVIDUAL TAF SITES.
MOUNTAINS AND DESERTS...SCT-BKN AND OCCASIONALLY OVC AOA FL100 WITH
SCT RW- AND ISOLD TRW THROUGH 02Z SAT. TSTM BASES WILL BE NEAR 8K
FT...BUT BRIEFLY LOWER OBSCURING HYR TRRN AT TIMES. ISOLD TSTM TOPS
FM FL400-450. THUNDERSTORMS MAY PRODUCE STG UP/DOWN DRAFTS AND LOCAL
SURFACE WIND GUSTS TO 40 KT WITH ASSOC LLWS.
&&
.MARINE...
MIX OF SOUTH SWELLS THROUGH THE WEEKEND WITH 2-3 FT...OCCASIONAL 4
FT SURF.
SOUTH SWELL WILL BE INCREASING MON-TUE...BRINGING ABOVE NORMAL SURF
AND STRONG RIP CURRENTS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH UNTIL 8 PM PDT THIS EVENING FOR THE APPLE AND
LUCERNE VALLEYS...COACHELLA VALLEY...RIVERSIDE COUNTY
MOUNTAINS...SAN BERNARDINO COUNTY MOUNTAINS...SAN DIEGO
COUNTY DESERTS...SAN DIEGO COUNTY MOUNTAINS.
PZ...NONE.
&&
$$
PUBLIC/FIRE WEATHER...BALFOUR
AVIATION/MARINE...JAD
SHORT TERM...SMALL/GONSALVES/TARDY
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1017 AM PDT FRI JUL 26 2013
.SYNOPSIS...
A GRADUAL COOL DOWN TO NEAR OR BELOW NORMAL TEMPERATURES IS
EXPECTED THROUGH EARLY NEXT WEEK. THE POSSIBILITY OF
THUNDERSTORMS WILL CONTINUE ALONG THE MOUNTAINS THROUGH SATURDAY.
&&
.SHORT TERM DISCUSSION...
THE AREA IS BETWEEN A WEAK CUTOFF LOW OFF THE COAST AND UPPER
LEVEL RIDGING CENTERED OVER THE FOUR CORNERS AREA. WATER VAPOR
SATELLITE IMAGERY SHOWS A NARROW PLUME OF MOISTURE FROM THE
EASTERN PACIFIC HEADING INTO THE NORTHERN SIERRA. MONSOONAL
MOISTURE ALONG WITH A SHORTWAVE IS MOVING NORTHWARD THROUGH
SOUTHERN CALIFORNIA. SOME THUNDERSTORMS ACTIVITY WITH THIS IS
EVIDENT AROUND BAKERSFIELD.
EXPECT SHOWERS AND THUNDERSTORMS TO DEVELOP THIS AFTERNOON AS THE
WAVE SHIFTS NORTHWOOD. THE ACTIVITY SHOULD BE FOCUSED OVER THE
SIERRA CREST THE MOUNTAINS OF WESTERN PLUMAS COUNTY AND SHASTA
COUNTY WITH BEST MOISTURE AND INSTABILITY. HAVE SCALED BACK THE
POSSIBITY OF THUNDERSTORMS OVER THE COASTAL MOUNTAINS WHERE
MOISTURE IS MORE LIMITED. RENO MORNING WEATHER BALLOON SOUNDING
SHOWS CAPE LEVELS OVER 1000 J/KG. HRRR MODEL SHOWS CONVECTION
BEGINNING TO DEVELOP BY LATE MORNING. RADAR SHOWS A FEW CELLS HAVE
ALREADY FORMED EAST OF BURNEY. STORMS SHOULD FORM NEAR THE CREST
AND WESTERLY FLOW SHOULD FAVOR MOVEMENT TO THE EAST. COULD BE SOME
HEAVY RAINFALL AGAIN TODAY ON THE EASTERN SLOPES OF THE SIERRA
WITH LOCAL FLOODING. SOME STORMS ALONG THE CREST MAY BE STRONG
WITH LARGE HAIL POSSIBLE. THUNDERSTORM ACTIVITY SHOULD CONTINUE
INTO THIS EVENING FOCUSED MAINLY OVER THE SIERRA. THIS SHOULD
WEAKEN AND SHIFT EASTWARD OVERNIGHT.
TEMPERATURES TODAY ARE STARTING COOLER...ESPECIALLY IN DELTA
INFLUENCED AREAS. WINDS ARE GUSTING OVER 30 MPH AT FAIRFIELD AND
EXPECT THIS TO CONTINUE TODAY AND TONIGHT. VACAVILLE IS 8 DEGREES
COOLER THAN THIS TIME YESTERDAY AT 73 DEGREES...AND SACRAMENTO
INTERNATIONAL AIRPORT IS 6 DEGREES COOLER AT 70 DEGREES. HAVE
DROPPED AFTERNOON HIGH TEMPERATURES A LITTLE DUE TO THE DELTA
BREEZE WITH HIGHS IN THE MID 90S AROUND SACRAMENTO. THE NORTHERN
SACRAMENTO VALLEY SHOULD REACH AROUND 105 AND THE NORTHERN SAN
JOAQUIN INTO THE UPPER 90S. IN THE EAST BAY VALLEJO SHOULD STAY IN
THE LOW 70S...WITH MORNING STRATUS BURNING OFF BY NOON. FORECAST
UPDATE IS OUT. EK
.EXTENDED DISCUSSION (TUESDAY THROUGH FRIDAY)
BENIGN WEATHER IS EXPECTED THROUGH THE EXTENDED PERIOD. THE FLOW
ALOFT TURNS SOUTHWESTERLY FOR THE FIRST PART OF NEXT WEEK AS A
WEAK TROUGH DEVELOPS OFF THE WEST COAST AND SLOWLY MOVES INLAND
BY THE WEEKEND. THIS PATTERN SHOULD KEEP THE REGION DRY. THIS
WILL KEEP TEMPERATURES BELOW NORMAL THROUGH THE MIDDLE OF NEXT
WEEK... WARMING UP TO NEAR NORMAL BY THE END OF NEXT WEEK.
DANG
&&
.AVIATION...
VFR CONDITIONS ALL TAF SITES NEXT 24 HOURS. WINDS GENERALLY BELOW
10 KNOTS EXCEPT THROUGH THE DELTA...WESTERLY 10 TO 20 KNOTS GUSTS
TO 30 KNOTS. THREAT OF THUNDERSTORMS OVER THE MOUNTAINS AFTER
18Z AND CONTINUING INTO TONIGHT.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
318 PM CDT FRI JUL 26 2013
.DISCUSSION...
ISSUED 300 PM CDT FRI JUL 26 2013
SHOWERS AND STORMS WILL BE POSSIBLE THROUGH TONIGHT ALONG A COLD
FRONT...THEN AN UNSEASONABLY COOL AIRMASS WILL SETTLE INTO
ILLINOIS FOR SATURDAY AND SUNDAY. A WARMING TREND WILL BEGIN ON
MONDAY AS UPPER FLOW BECOMES MORE ZONAL FROM WEST TO EAST. ONE LOW
PRESSURE SYSTEM IS EXPECTED TO EJECT FROM THE SOUTHERN PLAINS
ACROSS SOUTHERN ILLINOIS MONDAY NIGHT AND TUESDAY. A WEAKER UPPER
TROUGH WILL SWING ACROSS NORTHERN ILLINOIS ON THURSDAY...SETTING
UP NORTHWEST FLOW ALOFT THROUGH FRIDAY.
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT.
19Z SURFACE ANALYSIS SHOWS THE COLD FRONT APPROACHING THE
IOWA/ILLINOIS BORDER. RADAR SHOWS A NARROW LINE OF SHOWERS AND
STORMS ALONG THE FRONT IN IOWA...AND FARTHER SOUTHEAST AHEAD OF
THE FRONT IN EASTERN MISSOURI AND FAR WESTERN ILLINOIS. A BROAD
COVERAGE OF LIGHT RAIN SHOWERS EXTENDED ACROSS MUCH OF CENTRAL
ILLINOIS AND INTO WEST CENTRAL INDIANA. MOST AREAS IN CENTRAL
ILLINOIS WERE SEEING LESS THAN 0.10" OF RAIN OUT AHEAD OF THE
FRONT.
4KM NCEP AND HRRR OUTPUT INDICATE THE LINE WILL MAINTAIN SOME
INTENSITY DURING THE DAYLIGHT HOURS...BUT WEAKEN WITH SUNSET AS
THE LINE OF STORMS REACHES THE I-55 CORRIDOR. TIMING BASED ON
RADAR AND HRRR HAS THE LINE OF STORMS GENERALLY INTO INDIANA BY
08Z/3 AM. THE GFS/NAM/ECMWF/GEM ARE NOT FAR OFF FROM THAT
ASSESSMENT...SO WE HAVE UPDATED THE POPS LIKEWISE. BASICALLY,
SCATTERED COVERAGE IS EXPECTED ALONG AND AHEAD OF THE FRONT, SO
CHANCE POPS WERE USED /30-50 PCT/. SOME AREAS MAY SEE A STRONGER
UPDRAFT AND RECEIVED 0.25" RAIN IN A SHORT TIME, WHILE NEARBY
AREAS SEE LITTLE TO NO RAIN.
SATURDAY WILL FEATURE THE ARRIVAL OF A CHILLY CANADIAN AIRMASS AS
AIRFLOW BECOMES NORTH-NORTHWEST THROUGH A DEEP LAYER OF THE
ATMOSPHERE. 850MB TEMPS WILL DROP TO +6C IN OUR NORTH WITH 9-10C IN
THE SOUTH. ANY DAYTIME HEATING WILL CREATE STEEP LOW LEVEL LAPSE
RATES...WHICH WILL WORK TOGETHER WITH INCREASING BULK SHEAR AND
POSITIVE VORTICITY ADVECTION TO KICK OFF A FEW SHOWERS SATURDAY
AFTERNOON. MOST AREAS WILL PROBABLY REMAIN DRY...AND ANY RAIN THAT
DOES DEVELOP WILL NOT ADD UP TO 0.01"...SO WE WENT WITH SCATTERED
SPRINKLES FOR OUR NORTHERN COUNTIES SAT AFTN.
CLOUD COVER WILL DEVELOP QUICKLY IF ANY SUNSHINE BREAKS THROUGH
FOR ANY LENGTH OF TIME...WHICH WILL HELP TO KEEP HIGHS IN THE
70-73 DEG RANGE. WOULD NOT BE SURPRISED IF SOME LOCATIONS DO NOT
REACH 70 IF THE 6C LINE AT 850MB DOES REACH OUR COUNTIES. DRY
ADIABATIC MIXING OF 6C FROM 850MB WOULD ONLY PRODUCE A HIGH OF
66F. ANY SHOWERS WILL QUICKLY DISSIPATE WITH THE APPROACH OF
SUNSET.
RECORD OR NEAR RECORD LOWS ARE FORECAST FOR SATURDAY NIGHT.
CLEARING SKIES WILL BE A KEY COMPONENT OF THAT HAPPENING...BUT ALL
INDICATIONS ARE THAT CLOUDS WILL BE DIURNALLY DRIVEN AND SHOULD
DISSIPATE SAT EVE. LOW 50S WILL BE COMMON ACROSS THE FORECAST
AREA. RECORD LOW FOR PIA AND SPI SAT NIGHT IS 53.
SUNDAY MAY BE A CARBON COPY OF SATURDAY...WITH THE UPPER TROUGH
LINGERING ACROSS THE WESTERN GREAT LAKES AND INTO EASTERN
ILLINOIS, AND LITTLE CHANGE IN THE AIRMASS. SPOTTY SHOWERS AND
SPRINKLES WILL BE POSSIBLE...MAINLY IN THE NORTH CLOSER TO THE
COLDER AIR.
MONDAY WILL START A WARMING TREND AS THE UPPER TROUGH AXIS DEPARTS
TO THE EAST AND WESTERLY FLOW DEVELOP. THAT WILL SET THE STAGE FOR
A PROGRESSIVE LOW TO MOVE FROM THE PLAINS ACROSS SOUTHERN MISSOURI
AND SOUTHERN IL. SOME LOCALLY HEAVY RAIN WILL BE POSSIBLE LATER
MONDAY NIGHT AS THE LOW APPROACHES AND A WARM FRONT DEVELOPS
NEAR OUR SOUTHERN COUNTIES. THE MODELS HAVE TRENDED FARTHER SOUTH
WITH THE TRACK OF THE LOW THE LAST 2 MODEL RUNS...SO IT IS NOT OUT
OF THE QUESTION THAT LATER RUNS TAKE IT EVEN FARTHER SOUTH. WE
REDUCED LIKELY POPS TO CHANCE MONDAY NIGHT TO TREND DOWN...BUT
ADDED SOME LIKELY TO TUES IN OUR FAR SOUTHERN COUNTIES AS
GFS/ECMWF AGREE ON DECENT COVERAGE OF SHOWERS/STORMS DURING THE
DAY IN SOUTHERN IL RIGHT NOW. PRECIP WILL DIMINISH TUESDAY NIGHT
AS THE BULK OF THE FORCING FOR PRECIP DEPARTS TO THE EAST WITH THE
LOW.
WARMING WILL DEVELOP AHEAD OF THE LOW...AND DEWPOINTS WILL CLIMB
BACK INTO THE 60S WITH THE SYSTEM. LOCALLY HEAVY RAIN MAY DEVELOP
IN THE STRONGER STORMS...WITH RAINFALL RATES OF 1-2 INCHES PER
HOUR.
LONG TERM...WEDNESDAY THROUGH FRIDAY.
WEDNESDAY LOOKS MAINLY DRY AT THIS POINT, ALTHOUGH SOME ISOLATED
SHOWERS/STORMS WILL BE POSSIBLE AS NORTHWEST FLOW RETURNS AND
500MB SHORTWAVES MOVE INTO THE AREA. DEWPOINTS WILL CLIMB INTO THE
UPPER 60S BY WEDNESDAY...SO MUGGY FEELING AIR WILL RETURN AS HIGHS
CLIMB INTO THE LOWER 80S. SOME MID 80S FOR HIGHS WILL BE POSSIBLE
ON THURSDAY AND FRIDAY AS 850MB TEMPS CLIMB BACK TO 14-16C. RAIN
CHANCES INCREASE MORE DRAMATICALLY ON FRIDAY PER THE GFS...WITH A
STRONGER SYSTEM DROPPING SOUTHEAST FROM THE NORTHERN PLAINS. THE
ECMWF LAGS THE GFS BY 24 HRS WITH THAT FEATURE.
SHIMON
&&
.AVIATION...
ISSUED 1240 PM CDT FRI JUL 26 2013
BAND OF LIGHT SHOWERS WILL CONTINUE TO DISSIPATE ACROSS CENTRAL
ILLINOIS EARLY THIS AFTERNOON...WHILE MAIN FOCUS TURNS TO
ADVANCING COLD FRONT CURRENTLY ACROSS EASTERN IOWA. HIGH-RES
MODELS CONTINUE TO SHOW SCATTERED CONVECTION DEVELOPING
ALONG/AHEAD OF THE FRONT LATE THIS AFTERNOON INTO THE EVENING.
BASED ON HRRR TIMING...HAVE INCLUDED VCTS AT KPIA AFTER 21Z AND
FURTHER SOUTHEAST AT KDEC AND KCMI AFTER 23Z. FRONT WILL PROGRESS
EASTWARD TOWARD THE INDIANA BORDER BY MIDNIGHT...SO WILL END
THUNDER MENTION AFTER THE 02 TO 04Z TIME FRAME. WHILE FORECAST
SOUNDINGS TEND TO KEEP QUITE A BIT OF CLOUD COVER IN PLACE BEHIND
THE FRONT...UPSTREAM SATELLITE IMAGERY REVEALS MAINLY DIURNAL
CLOUD COVER ACROSS IOWA. HAVE THEREFORE SCATTERED OUT THE LOW VFR
CEILINGS AFTER FROPA FROM LATE EVENING THROUGH THE OVERNIGHT
HOURS. AS DEEP UPPER LOW CURRENTLY OVER NORTHERN MINNESOTA DIGS
SOUTHWARD...A POCKET OF COLD AIR ALOFT WILL LEAD TO STEEP LAPSE
RATES SATURDAY AFTERNOON. GIVEN 500MB TEMPS OF -16 TO -18C...THINK
SCT-BKN CU WILL DEVELOP AT AROUND 5000FT. MAY EVEN BE SOME
SCATTERED LIGHT SHOWERS AROUND THE AREA AS WELL...BUT TOO SPOTTY
TO MENTION IN TAFS. WINDS WILL INITIALLY BE FROM THE S/SW AT
AROUND 10KT THIS AFTERNOON...THEN WILL BECOME NORTHWESTERLY
TONIGHT INTO SATURDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1240 PM CDT FRI JUL 26 2013
.DISCUSSION...
ISSUED 916 AM CDT FRI JUL 26 2013
14Z/9AM RADAR IMAGERY SHOWS SHOWERS PUSHING ACROSS THE NORTHWEST
KILX CWA...WITH RAIN BEING REPORTED AT BOTH KGBG AND KPIA. AIRMASS
IS INITIALLY QUITE DRY BELOW 850MB...SO RAIN WILL HAVE DIFFICULTY
TRACKING MUCH FURTHER EAST. HAVE UPDATED POPS TO CATEGORICAL ALONG
AND NORTH OF A RUSHVILLE TO BLOOMINGTON-NORMAL LINE...BUT WILL
HANG ON TO JUST CHANCE POPS FURTHER SOUTHEAST TO THE I-72 CORRIDOR.
THINK SHOWERS WILL ADVANCE EASTWARD AND GRADUALLY DISSIPATE AS
THEY APPROACH THE INDIANA BORDER EARLY THIS AFTERNOON. AFTER
THAT...HIGH-RES HRRR SHOWS ADDITIONAL SHOWERS/THUNDER FORMING
ALONG A SLOWLY ADVANCING COLD FRONT WEST OF THE ILLINOIS RIVER BY
LATE THIS AFTERNOON. THIS CONVECTION WILL WORK ITS WAY EASTWARD
ACROSS THE AREA THIS EVENING. ZONE UPDATE HAS ALREADY BEEN SENT.
BARNES
&&
.AVIATION...
ISSUED 1240 PM CDT FRI JUL 26 2013
BAND OF LIGHT SHOWERS WILL CONTINUE TO DISSIPATE ACROSS CENTRAL
ILLINOIS EARLY THIS AFTERNOON...WHILE MAIN FOCUS TURNS TO
ADVANCING COLD FRONT CURRENTLY ACROSS EASTERN IOWA. HIGH-RES
MODELS CONTINUE TO SHOW SCATTERED CONVECTION DEVELOPING
ALONG/AHEAD OF THE FRONT LATE THIS AFTERNOON INTO THE EVENING.
BASED ON HRRR TIMING...HAVE INCLUDED VCTS AT KPIA AFTER 21Z AND
FURTHER SOUTHEAST AT KDEC AND KCMI AFTER 23Z. FRONT WILL PROGRESS
EASTWARD TOWARD THE INDIANA BORDER BY MIDNIGHT...SO WILL END
THUNDER MENTION AFTER THE 02 TO 04Z TIME FRAME. WHILE FORECAST
SOUNDINGS TEND TO KEEP QUITE A BIT OF CLOUD COVER IN PLACE BEHIND
THE FRONT...UPSTREAM SATELLITE IMAGERY REVEALS MAINLY DIURNAL
CLOUD COVER ACROSS IOWA. HAVE THEREFORE SCATTERED OUT THE LOW VFR
CEILINGS AFTER FROPA FROM LATE EVENING THROUGH THE OVERNIGHT
HOURS. AS DEEP UPPER LOW CURRENTLY OVER NORTHERN MINNESOTA DIGS
SOUTHWARD...A POCKET OF COLD AIR ALOFT WILL LEAD TO STEEP LAPSE
RATES SATURDAY AFTERNOON. GIVEN 500MB TEMPS OF -16 TO -18C...THINK
SCT-BKN CU WILL DEVELOP AT AROUND 5000FT. MAY EVEN BE SOME
SCATTERED LIGHT SHOWERS AROUND THE AREA AS WELL...BUT TOO SPOTTY
TO MENTION IN TAFS. WINDS WILL INITIALLY BE FROM THE S/SW AT
AROUND 10KT THIS AFTERNOON...THEN WILL BECOME NORTHWESTERLY
TONIGHT INTO SATURDAY.
BARNES
&&
.PREV DISCUSSION...
ISSUED 348 AM CDT FRI JUL 26 2013
PRECIPITATION MOVING CLOSER AHEAD OF AN ADVANCING COLD FRONT
MOVING INTO THE REGION. THE FRONT WILL DRIVE THE FORECAST IN THE
SHORT TERM WITH POPS FOR TODAY AND TONIGHT SLOWLY TAKING OVER THE
HIGH PRESSURE SLIDING OFF TO THE EAST. SYNOPTIC SCALE TROF AT H5
IN THE UPPER MIDWEST AND GREAT LAKES DRIVING THE FRONT INTO AND
ACROSS THE MIDWEST. COOLER TEMPS AND PARTLY CLOUDY SKIES WILL
DOMINATE THROUGH MOST OF THE WEEKEND WITH THE TROF REMAINING IN
PLACE OVER THE GREAT LAKES AND LEAVING CYCLONIC FLOW ALOFT. NEXT
ISSUES FOR THE FORECAST WILL BE THE NEXT SYSTEM MON/TUESDAY THAT
THE MODELS ARE STILL HAVING A BIT OF A DISAGREEMENT ABOUT...THOUGH
THE OFFICIAL FORECAST IS LEANING TOWARDS THE ECMWF OVERALL...WITH
A SLIGHTLY MORE AGGRESSIVE ADVANCE OF THE QPF ON MON NIGHT.
SHORT TERM...TODAY AND TOMORROW...
FASTER ADVANCE OF THE FRONT IN THE FORECAST...WITH THE PRE FRONTAL
PRECIP ALREADY TO THE NW AND CREEPING INTO THE FA. ADVANCING THE
POPS THROUGH THE AFTERNOON AND EVENING. ISO TS IN THE
MORNING...THOUGH SHOWERS MAY SCATTER A BIT INTO THE
AFTERNOON...THE THUNDER WILL MORE LIKELY ACCOMPANY THE ACTIVITY.
WITH THE FASTER MOVEMENT...THE FORECAST DRIES CONSIDERABLY GOING
INTO SATURDAY. THOUGH THE CYCLONIC FLOW ALOFT AND MODERATE RH IN
THE BOUNDARY LAYER...FORECAST SOUNDINGS ARE HINTING AT A BIT OF A
CAP ABOVE 800MB RESULTING IN A BIT OF A LIMITATION TO CONVECTIVE
GROWTH. SO INSTABILITY SHOWERS THAT MAY HAVE BEEN A RISK FOR SAT
AFTERNOON WILL BE LIMITED SOMEWHAT SHOULD THAT CAP MATERIALIZE.
WILL NEED TO KEEP AN EYE ON THAT PORTION OF THE FORECAST. THOUGH
TEMPERATURES TODAY WILL BE IN THE UPPER 70S/NEAR 80...TOMORROW
BEHIND THE FRONT WILL BE CONSIDERABLY COOL FOR THE END OF
JULY...WITH HIGHS IN THE LOW TO MID 70S. SAT NIGHT/SUN MORNING
WITH CLEARING SKIES AND MUCH COLDER AIR MOVING INTO THE
MIDLEVELS...6 TO 7C AT 850...SAT NIGHT TEMPS DROP INTO THE LOWER
50S.
LONG TERM...SUNDAY THROUGH THURSDAY...
WESTERLY FLOW SETS UP AT THE SFC TRYING TO ADVECT SOME WARMER
TEMPS FROM UNDER THE PERSISTENT AND EXPANSIVE RIDGE OVER THE
WESTERN HALF OF THE CONUS...BUT THE WARM UP IS SLOW THROUGH SUN
AND MON. NEXT ISSUE ARRIVES MON NIGHT. GFS IS FAR MORE
CONSERVATIVE FOR ILX YET AGAIN...KEEPING THE SFC LOW FURTHER SOUTH
AND THE ECMWF BEING THE MORE EXPANSIVE WITH THE QPF AND MORE
PROLONGED WITH SOME SLIGHT CONVECTIVE FEEDBACK ISSUES THROUGH
WEDNESDAY. ALLBLEND SEEMS TO LEAN HEAVILY TOWARDS THE MORE
AGGRESSIVE AND WET ECMWF. TEMPERATURES CONTINUE TO MODERATE
THROUGH THE EXTENDED AS QUASI ZONAL FLOW SETS UP ACROSS THE
COUNTRY IN THE LAST HALF OF THE WORK WEEK.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
104 PM CDT FRI JUL 26 2013
.UPDATE...
ISSUED AT 1257 PM CDT FRI JUL 26 2013
BASED ON SATELLITE AND OBS...THE COLD FRONT WAS JUST WEST OF A
KPDC TO KCNC LINE AT 17Z. NEW DIURNAL CONVECTION IS DEVELOPING IN
THE AREA AHEAD OF THE COLD FRONT AND ALONG/BEHIND THE PRE-FRONTAL
TROF. TRENDS IN THE MODELS SHOW A NARROW OPPORTUNITY FOR
CONVECTION AS THESE FEATURES MOVE EAST DUE TO FAVORABLE FORCING
AND STEEP LAPSE RATES IN THE 850-700MB LAYER.
THE TRENDS WITH THE RAP MODEL IS TO SLOWLY RAISE THE CONVECTIVE
TEMPERATURES INTO THE UPPER 70S TO AROUND 80 DURING THE AFTERNOON
HOURS. THUS MORE SHOWERS THAN THUNDERSTORMS ARE EXPECTED. BASED ON
THE CAA BEHIND THE FRONT...MAX TEMPERATURES WERE LOWERED SLIGHTLY
DUE TO THE CLOUDS. ..08..
UPDATE ISSUED AT 1007 AM CDT FRI JUL 26 2013
THE RAIN IS ESSENTIALLY EAST OF THE MISSISSIPPI AS OF 15Z WITH
BREAKS IN THE CLOUDS DEVELOPING AHEAD OF THE MAIN CLEARING. THE
IMMEDIATE TREND WILL BE DRY CONDITIONS AS THE PRECIPITATION
CONTINUES TO MOVE EAST AND EXIT THE AREA.
LOW LEVEL LAPSE RATES WILL STEEPEN DURING THE LATE MORNING AND
AFTERNOON HOURS. THE COLD FRONT IS MAKING GOOD PROGRESS TO THE
EAST AND WILL BE ENTERING THE NORTHWEST PART OF THE CWFA WITHIN
THE NEXT 2 HOURS.
THE QUESTION NOW IS HOW MUCH DIURNAL CONVECTION WILL OCCUR
ASSOCIATED WITH THE COLD FRONT THIS AFTERNOON. THE ATMOSPHERE IS
DRYING OUT AND THE FORCING IS LIMITED TO ALONG AND JUST AHEAD OF
THE COLD FRONT. THE MCS AND LIFT TOOLS OFFER MIXED RESULTS BUT
SUGGEST THE BETTER CHANCES OF DIURNAL CONVECTION ARE FROM THE
MISSISSIPPI ON EAST THIS AFTERNOON. ..08..
UPDATE ISSUED AT 656 AM CDT FRI JUL 26 2013
DOPPLER RADAR INDICATED THAT THE BULK OF THE SHOWERS HAVE SHIFTED
TO THE SOUTH OF INTERSTATE 80 AND WERE SLOWLY DIMINISHING IN COVERAGE.
ISOLATED SHOWERS WERE NOTED TO THE NORTH OF I-80. RAPID REFRESH
MODEL INDICATES A NARROW LINE OF SHOWERS AND A FEW THUNDERSTORMS
WITH THE COLD FRONT LATER THIS MORNING INTO THE AFTERNOON.
&&
.SYNOPSIS...
ISSUED AT 300 AM CDT FRI JUL 26 2013
FORCING/VERTICAL MOTION FROM UPPER LEVEL TROUGH IN THE UPPER
MIDWEST DROPPING SOUTHEAST CONTINUED TO SPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS MUCH OF THE DVN CWA. MODERATE TO HEAVY RAIN
WAS OCCURRING AT SOME LOCATIONS. CURRENT TEMPERATURES IN THE CWA
RANGED FROM THE MID 60S TO LOWER 70S. A STRONG COLD FRONT EXTENDED
FROM EASTERN MN TO NORTHWEST IA TO THE TX PANHANDLE. CURRENT
TEMPERATURES WERE IN THE UPPER 40S TO MID 50S ACROSS PORTIONS OF
THE DAKOTAS AND NORTHERN MN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM CDT FRI JUL 26 2013
FORECAST FOCUS ON ENDING THE RAIN TODAY THEN NEAR RECORD LOWS TONIGHT.
TODAY...STRONGEST FORCING IS OCCURRING THIS MORNING DRIVING AN
AREA OF SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE CWA. WILL
CARRY LIKELY POPS INTO THIS MORNING. THE COLD FRONT WILL ENTER OUR
NORTHWEST CWA LATER THIS MORNING REACHING THE MS RIVER THIS AFTERNOON
AND THEN EXITING OUR FAR EASTERN COUNTIES TOWARDS EVENING. SHOWER
ACTIVITY SHOULD BECOME MORE SCATTERED LATER THIS MORNING AND THEN
REDEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED THIS
AFTERNOON AHEAD OF THE FRONT. EXTENSIVE CLOUD COVER SHOULD LIMIT
INSTABILITY AND INTENSITY OF STORMS. HOWEVER...IF MORE SUNSHINE
OCCURS MORE THAN EXPECTED THEN A STRONG STORM IS POSSIBLE IN OUR
ILLINOIS COUNTIES THIS AFTERNOON. BEHIND THE FRONT DRIER AIR ON
GUSTY NORTHWEST WINDS WILL ALLOW THE SUN TO RETURN. MAXIMUM
TEMPERATURES WILL BE IN THE MID 70S TO NEAR 80 THIS AFTERNOON.
TONIGHT...UPPER LOW WILL BE SITUATED ACROSS LAKE SUPERIOR WITH
CANADIAN HIGH PRESSURE NOSING INTO THE DVN CWA...BUT THE CENTER OF
THE HIGH WILL STILL BE NEAR LAKE WINNIPEG. MOSTLY CLEAR SKIES CAN
BE EXPECTED BUT NORTHWEST WINDS WILL STAY NEAR 10 MPH. WILL BE A
COOL NIGHT WITH MINIMUM TEMPERATURES RANGING FROM 49 AT INDEPENDENCE
TO 54 AT MACOMB AND PRINCETON. THESE READINGS WILL BE A COUPLE OF
DEGREES SHY OF RECORD LOWS. HOWEVER...IF THE WINDS MANAGE TO GO
CALM FOR A TIME THEN THESE RECORD LOWS MAY BE IN JEOPARDY. SEE
CLIMATE SECTION BELOW FOR DETAILS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 300 AM CDT FRI JUL 26 2013
NEAR RECORD COOL TEMPERATURES THIS WEEKEND...THEN MOSTLY DRY WITH
MODERATING TEMPERATURES TO NEAR NORMAL FOR LATE JULY.
OVERVIEW...INITIALIZATION AND VERIFICATION GOOD EXCEPT FOR NORMAL
MOISTURE ISSUES OF TOO HIGH BL RH VALUES AND DEWPOINTS IMPACTING
PRECIPITATION. THIS WILL HAVE LITTLE IMPACT AFTER THE NEXT 12-18 HOURS.
VERIFICATION AND RUN TO RUN CONTINUITY SUPPORTS MORE OF A 60/40
MIX OF THE HI-RES ECMWF AND GFS/GEM-NH. THIS PORTENDS MOSTLY DRY
CONDITIONS WITH CHANCE OF LIGHT TO MODERATE PRECIPITATION EARLY
NEXT WEEK WITH TEMPERATURES RISING TO NEAR NORMAL BY MID WEEK.
SATURDAY THROUGH SUNDAY...SEASONALLY STRONG CANADIAN HIGH PRESSURE
TO BRING MOSTLY CLEAR SKIES WITH VERY COOL TEMPERATURES AND LOW
HUMIDITY LEVELS. MID DAY FAIR WEATHER CUMULUS CLOUDS FOR CHAMBER
OF COMMERCE KIND OF WEATHER AND LIGHT WINDS. 850 TEMPERATURES OF
+5 TO +8C SUPPORTS HIGHS SATURDAY MIDDLE 60S NORTH TO LOWER 70S
SOUTH. NEAR RECORD MINS SUGGESTED FOR SUNDAY AM WITH LOCAL TOOLS
SUGGESTING LOWS WITHIN A DEGREE OR TWO OF AREA RECORDS LISTED IN
CLIMATE SECTION BELOW. SUNDAY...FAIR WEATHER WITH HIGHS 3 TO 5
DEGREES HIGHER THAN SATURDAY...LOWER 70S NORTH TO MIDDLE 70S FAR
SOUTH SECTIONS. OVERALL...THESE TEMPERATURES ARE 10-15+ DEGREES BELOW
NORMAL FOR LATE JULY.
MONDAY THROUGH THURSDAY...POPS MAY NEED LOWERING MON/TUE WITH BEST
FORCING TO THE SOUTH AND LIMITED MOISTURE AS WEST AND NORTHWEST
UPPER LEVEL FLOW TO KEEP AREA FROM WARMING MUCH BEYOND SEASONABLE
TEMPERATURES INTO LATE NEXT WEEK. TRACK OF DISTURBANCE EARLY NEXT
WEEK SHOULD BE CLARIFIED IN THE NEXT 12-24 HOURS. LOCAL TOOLS
SUGGEST MINS BEYOND TUESDAY AM INTO FRIDAY MAY NEED TRIMMING BY 1-3
DEGREES MOST LOCATIONS FOR LATER SHIFTS.
NICHOLS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1257 PM CDT FRI JUL 26 2013
MVFR CIGS WILL SLOWLY RAISE TO VFR THROUGH 00Z/27 AS A COLD FRONT
MOVES THROUGH EASTERN IOWA AND ILLINOIS. NEW DIURNAL CONVECTION IS
DEVELOPING AHEAD OF THE COLD FRONT AND VCSH WAS INCLUDED IN ALL
TAFS. KBRL HAS THE BEST CHANCE ALBEIT LOW AT SEEING A TSRA SO VCTS
WAS DONE THERE. A BRIEF PERIOD OF MVFR OR IFR CONDITIONS MAY OCCUR
IF A SHRA OR TSRA IMPACTS A TAF SITE. AFT 00Z/27 VFR CONDITIONS
ARE EXPECTED TO CONTINUE. ..08..
&&
.CLIMATE...
ISSUED AT 300 AM CDT FRI JUL 26 2013
RECORD LOWS FOR JULY 27...
MOLINE.........50 IN 1962
CEDAR RAPIDS...48 IN 1937
DUBUQUE........48 IN 1971
BURLINGTON.....49 IN 2004
RECORD LOWS FOR JULY 28...
MOLINE.........52 IN 1925
CEDAR RAPIDS...47 IN 1925
DUBUQUE........51 IN 2005+
BURLINGTON.....53 IN 1981
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...NICHOLS
AVIATION...08
CLIMATE...HAASE
AREA FORECAST DISCUSSION
NWS WICHITA KS
1231 PM CDT FRI JUL 26 2013
.UPDATE...
ISSUED AT 1124 AM CDT FRI JUL 26 2013
AN AREA OF SHOWERS LINGERED ACROSS SOUTHEAST KANSAS AT LATE MORNING.
LATEST RUC SUGGESTS RESIDUAL LOW LEVEL MOISTURE AND RELATIVELY
COOL MID-LEVEL TEMPS WILL SUPPORT DIURNAL CU/STRATOCU INTO THE
EARLY AFTERNOON AND PERHAPS ISOLATED SHALLOW CONVECTION EAST OF
THE KANSAS TURNPIKE. HOWEVER THE RISK FOR ORGANIZED HEAVY RAINFALL
HAS DIMINISHED ACROSS THE AREA.
KED
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT FRI JUL 26 2013
WE BEGIN THE FORECAST WITH NUMEROUS SHOWERS AND THUNDERSTORMS.
MOISTURE TRANSPORT IS STRONG INTO SOUTH CENTRAL KANSAS WHERE NEW
DEVELOPMENT IS OCCURRING AS OF THIS FORECAST ISSUANCE. THE MAIN
ACTIVITY IS SLOWLY PROPAGATING SOUTHEAST...BUT THIS NEW
DEVELOPMENT WILL KEEP SHOWERS/THUNDERSTORMS IN THE
AREA...ESPECIALLY EXTREME SOUTH CENTRAL AND SOUTHEASTERN KANSAS
INTO THE MORNING HOURS. CURRENTLY SEEING RATES ABOUT 1-2 INCHES AN
HOUR WITH THIS EFFICIENT ACTIVITY. WILL KEEP THE FLOOD WATCH
THROUGH 1PM. CANNOT RULE OUT A FLOOD WARNING WITH THIS ACTIVITY
OVER THE SATURATED SOUTHERN COUNTIES. THINKING THE ACTIVITY WILL
IMPACT SOUTHEAST KANSAS THROUGH PART OF THE MORNING AND EARLY
AFTERNOON...BUT CLEARING OUT QUICKLY BEHIND IT OVER CENTRAL KANSAS.
THE MAIN DISTURBANCE WILL MOVE ACROSS THE AREA THIS
EVENING...PUSHING ALL ACTIVITY SOUTH AND EAST OF THE AREA WITH
SUBSIDENCE MOVING IN BEHIND THE WAVE. HOWEVER...ANOTHER DEEPER PV
ANOMALY WILL DIVE SOUTHEAST INTO THE UPPER TROUGH. THIS WAVE WILL
HELP TO SPARK A CONVECTIVE COMPLEX IN NEBRASKA THAT IS CURRENTLY
EXPECTED TO DIVE SOUTHEAST OVER NORTHEAST KANSAS. THE LAST COUPLE
OF NAM AND ECMWF RUNS ARE MORE BULLISH WITH THIS ACTIVITY FOR
SATURDAY...BUT THE GFS HINTS AT IT AS WELL. HAVE INCREASED POPS...BUT
KEPT THE MAJORITY OF THE ACTIVITY OVER NORTHEAST KANSAS.
THINK THE BETTER CHANCES FOR PRECIPITATION FOR THE WHOLE AREA WILL
BE SATURDAY NIGHT/SUNDAY AND INTO MONDAY AS WARM MOIST AIR RETURNS
AND A SURFACE BOUNDARY SETS UP OVER THE AREA. PRECIPITATION IS
EXPECTED TO MOVE IN FROM THE WEST INTO SUNDAY AND HAVE KEPT THE
MODERATE TO HIGH CHANCES FROM THE PREVIOUS FORECAST.
TEMPERATURES ARE COOL FROM TODAY THROUGH MONDAY WITH THE
CONSISTENT CLOUD COVER AND OFF AND ON SHOWERS AND THUNDERSTORMS.
OUTFLOW BOUNDARIES ARE EXPECTED TO BE IN/AROUND THE AREA WHICH
WILL MODIFY THE LATE JULY AIRMASS. EXPECTING NEARLY 5-10 DEGREE
BELOW NORMAL TEMPS FOR THE WEEKEND.
BILLINGS
.LONG TERM...(TUESDAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI JUL 26 2013
THE UPPER LEVEL PATTERN TRIES TO BECOME MORE ZONAL...WITH THE UPPER
HIGH PRESSURE LACKING MUCH EASTWARD MOTION WITH THE POTENT UPPER
LEVEL LOWS DIVING SOUTHEAST ACROSS CENTRAL AND THE EASTERN CONUS.
THE CENTRAL PLAINS REMAINS IN NORTHWESTERLY UPPER LEVEL FLOW. OFF
AND ON SCATTERED SHOWERS/THUNDERSTORMS WILL BE POSSIBLE WITH THE
SURFACE BOUNDARY STICKING AROUND THE AREA THROUGH THE
EXTENDED....BUT CURRENTLY THINK THERE WILL BE MORE TIME DRY THAN
WET BETWEEN TUESDAY AND THURSDAY. THIS WILL ALLOW TEMPERATURES TO
WARM UP TO NEARER TO THE LOW 90S NORMAL FOR THE END OF JULY/FIRST
OF AUGUST.
BILLINGS
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1232 PM CDT FRI JUL 26 2013
MOIST LOW LEVELS AND RELATIVELY COOL TEMPERATURES ALOFT WILL
RESULT IN LINGER CU/STRATOCU MVFR CIGS AND SHALLOW CONVECTION
ACROSS SOUTHEAST KANSAS THIS AFTERNOON. OTHERWISE SOMEWHAT DRIER
AIR ON NORTHEAST WINDS WILL ADVECT ACROSS THE AREA TONIGHT WITH
VFR CONDITIONS EXPECTED ALL AREAS AFTER SUNSET THIS EVENING.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 85 62 83 65 / 10 0 10 30
HUTCHINSON 85 61 81 65 / 10 0 10 30
NEWTON 85 60 79 64 / 10 0 10 30
ELDORADO 84 60 80 63 / 20 0 10 30
WINFIELD-KWLD 84 62 84 65 / 20 0 10 20
RUSSELL 84 61 81 64 / 10 0 10 40
GREAT BEND 85 61 83 64 / 10 0 20 40
SALINA 85 60 81 64 / 10 0 20 30
MCPHERSON 85 61 80 64 / 10 0 10 30
COFFEYVILLE 79 62 83 64 / 60 10 10 10
CHANUTE 80 60 80 63 / 30 0 20 10
IOLA 80 59 79 62 / 20 0 20 10
PARSONS-KPPF 79 61 80 64 / 40 0 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1120 AM CDT FRI JUL 26 2013
.UPDATE...
ISSUED AT 1124 AM CDT FRI JUL 26 2013
AN AREA OF SHOWERS LINGERED ACROSS SOUTHEAST KANSAS AT LATE MORNING.
LATEST RUC SUGGESTS RESIDUAL LOW LEVEL MOISTURE AND RELATIVELY
COOL MID-LEVEL TEMPS WILL SUPPORT DIURNAL CU/STRATOCU INTO THE
EARLY AFTERNOON AND PERHAPS ISOLATED SHALLOW CONVECTION EAST OF
THE KANSAS TURNPIKE. HOWEVER THE RISK FOR ORGANIZED HEAVY RAINFALL
HAS DIMINISHED ACROSS THE AREA.
KED
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM CDT FRI JUL 26 2013
WE BEGIN THE FORECAST WITH NUMEROUS SHOWERS AND THUNDERSTORMS.
MOISTURE TRANSPORT IS STRONG INTO SOUTH CENTRAL KANSAS WHERE NEW
DEVELOPMENT IS OCCURRING AS OF THIS FORECAST ISSUANCE. THE MAIN
ACTIVITY IS SLOWLY PROPAGATING SOUTHEAST...BUT THIS NEW
DEVELOPMENT WILL KEEP SHOWERS/THUNDERSTORMS IN THE
AREA...ESPECIALLY EXTREME SOUTH CENTRAL AND SOUTHEASTERN KANSAS
INTO THE MORNING HOURS. CURRENTLY SEEING RATES ABOUT 1-2 INCHES AN
HOUR WITH THIS EFFICIENT ACTIVITY. WILL KEEP THE FLOOD WATCH
THROUGH 1PM. CANNOT RULE OUT A FLOOD WARNING WITH THIS ACTIVITY
OVER THE SATURATED SOUTHERN COUNTIES. THINKING THE ACTIVITY WILL
IMPACT SOUTHEAST KANSAS THROUGH PART OF THE MORNING AND EARLY
AFTERNOON...BUT CLEARING OUT QUICKLY BEHIND IT OVER CENTRAL KANSAS.
THE MAIN DISTURBANCE WILL MOVE ACROSS THE AREA THIS
EVENING...PUSHING ALL ACTIVITY SOUTH AND EAST OF THE AREA WITH
SUBSIDENCE MOVING IN BEHIND THE WAVE. HOWEVER...ANOTHER DEEPER PV
ANOMALY WILL DIVE SOUTHEAST INTO THE UPPER TROUGH. THIS WAVE WILL
HELP TO SPARK A CONVECTIVE COMPLEX IN NEBRASKA THAT IS CURRENTLY
EXPECTED TO DIVE SOUTHEAST OVER NORTHEAST KANSAS. THE LAST COUPLE
OF NAM AND ECMWF RUNS ARE MORE BULLISH WITH THIS ACTIVITY FOR
SATURDAY...BUT THE GFS HINTS AT IT AS WELL. HAVE INCREASED POPS...BUT
KEPT THE MAJORITY OF THE ACTIVITY OVER NORTHEAST KANSAS.
THINK THE BETTER CHANCES FOR PRECIPITATION FOR THE WHOLE AREA WILL
BE SATURDAY NIGHT/SUNDAY AND INTO MONDAY AS WARM MOIST AIR RETURNS
AND A SURFACE BOUNDARY SETS UP OVER THE AREA. PRECIPITATION IS
EXPECTED TO MOVE IN FROM THE WEST INTO SUNDAY AND HAVE KEPT THE
MODERATE TO HIGH CHANCES FROM THE PREVIOUS FORECAST.
TEMPERATURES ARE COOL FROM TODAY THROUGH MONDAY WITH THE
CONSISTENT CLOUD COVER AND OFF AND ON SHOWERS AND THUNDERSTORMS.
OUTFLOW BOUNDARIES ARE EXPECTED TO BE IN/AROUND THE AREA WHICH
WILL MODIFY THE LATE JULY AIRMASS. EXPECTING NEARLY 5-10 DEGREE
BELOW NORMAL TEMPS FOR THE WEEKEND.
BILLINGS
.LONG TERM...(TUESDAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT FRI JUL 26 2013
THE UPPER LEVEL PATTERN TRIES TO BECOME MORE ZONAL...WITH THE UPPER
HIGH PRESSURE LACKING MUCH EASTWARD MOTION WITH THE POTENT UPPER
LEVEL LOWS DIVING SOUTHEAST ACROSS CENTRAL AND THE EASTERN CONUS.
THE CENTRAL PLAINS REMAINS IN NORTHWESTERLY UPPER LEVEL FLOW. OFF
AND ON SCATTERED SHOWERS/THUNDERSTORMS WILL BE POSSIBLE WITH THE
SURFACE BOUNDARY STICKING AROUND THE AREA THROUGH THE
EXTENDED....BUT CURRENTLY THINK THERE WILL BE MORE TIME DRY THAN
WET BETWEEN TUESDAY AND THURSDAY. THIS WILL ALLOW TEMPERATURES TO
WARM UP TO NEARER TO THE LOW 90S NORMAL FOR THE END OF JULY/FIRST
OF AUGUST.
BILLINGS
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 619 AM CDT FRI JUL 26 2013
MAIN AREA OF SHOWERS/T-STORMS WILL EXIT SOUTHEASTERN KS BY MID
MORNING. THIS ACTIVITY WILL AFFECT CNU EARLY ON. BRIEF MVFR
VSBYS/CIGS POSSIBLE EARLY THIS MORNING IN CENTRAL KS WHERE PARTIAL
CLEARING HAS OCCURRED OVER WET GROUND. CLEARING WILL OCCUR FROM
NORTHWEST TO SOUTHEAST TODAY BEHIND THE DEPARTING UPPER LEVEL
DISTURBANCE. NORTHEASTERLY WINDS GUSTING TO 20-25 KT EXPECTED FROM
LATE MORNING UNTIL EARLY EVENING BEFORE DIMINISHING.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 85 62 83 65 / 10 10 10 30
HUTCHINSON 85 61 81 65 / 10 10 10 30
NEWTON 85 60 79 64 / 10 10 10 30
ELDORADO 84 60 80 63 / 20 10 10 30
WINFIELD-KWLD 84 62 84 65 / 20 10 10 20
RUSSELL 84 61 81 64 / 10 10 10 40
GREAT BEND 85 61 83 64 / 10 10 10 40
SALINA 85 60 81 64 / 10 10 20 30
MCPHERSON 85 61 80 64 / 10 10 10 30
COFFEYVILLE 79 62 83 64 / 70 10 10 10
CHANUTE 80 60 80 63 / 30 10 20 10
IOLA 80 59 79 62 / 20 10 20 10
PARSONS-KPPF 79 61 80 64 / 60 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
1229 PM EDT FRI JUL 26 2013
.SYNOPSIS...
LOW PRESSURE WILL MOVE TO THE NORTHEAST ALONG A FRONT ACROSS THE
GULF OF MAINE TODAY AND INTO THE MARITIMES TONIGHT. THIS WILL
PROVIDE RAIN FOR MUCH OF THE REGION INTO TONIGHT WITH THE HEAVIEST
RAIN EXPECTED OVER MORE EASTERN AREAS OF MAINE WHILE NEW HAMPSHIRE
SEES THE LOWEST RAINFALL TOTALS. A WEAK AREA OF HIGH PRESSURE
BUILDS INTO THE REGION ON SATURDAY GIVING US VERY WARM AND DRY
WEATHER. A SLOW-MOVING COLD FRONT WILL APPROACH FROM THE GREAT
LAKES LATE SUNDAY THEN EXIT THE COAST ON MONDAY. AN UPPER LOW WILL
PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR TUESDAY. A WEAK
RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY. ANOTHER DISTURBANCE
WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
LIGHT RAIN CONTINUES OVER SOUTHERN AREAS PER LATEST OBSERVATIONS
AND RADAR TRENDS. THE INTENSITY WILL LIKELY CONTINUE TO PICK UP
FOR THE NEXT HOUR OR SO ALONG THE MIDCOAST AS LOW PRESSURE CROSSES
THROUGH THE GULF OF MAINE THIS AFTERNOON. LATEST HRRR RUN SHOWS
MAIN BULK OF PCPN RIDING JUST EAST OF OUR FORECAST AREA...FROM THE
PENOBSCOT RIVER VALLEY AND POINTS EAST...BRINGING A QUICK INCH OR
TWO OF RAIN THIS AFTERNOON ALONG THE EASTERNMOST PORTIONS OF OUR
FORECAST AREA. THIS IS BELOW FLASH FLOOD GUIDANCE. HOWEVER...WILL
CONTINUE TO MONITOR EASTERN AREAS FOR THE POTENTIAL FOR HEAVY
RAINFALL AS PRECIPITABLE WATER VALUES REMAIN VERY HIGH DURING THE
AFTERNOON.
OTHERWISE...ONLY MINOR MODIFICATIONS TO THE GRIDS THIS MORNING.
PREV DISC...
WILL UPDATE TO INPUT LATEST OBSERVED DATA...RESULTING IN
SLOWING DOWN THE ONSET OF RAIN ACROSS THE FCST AREA THIS MORNING.
RAIN HAS MOVED INTO COASTAL AND ADJACENT INTERIOR ZONES BUT HASN`T
PUSHED MUCH FURTHER INLAND AT THIS TIME. STILL EXPECT RAIN TO
SURGE NORTHWARD ACROSS THE FCST AREA TODAY.
THE TRACK OF THE SFC LOW WILL BE ALONG A STALLED FRONT OVER THE
GULF OF MAINE TODAY. THIS WILL SPREAD RAIN ACROSS MUCH OF THE
FORECAST AREA WITH THE HEAVIEST RAIN OVER EASTERN AREAS...WHILE
NEW HAMPSHIRE...ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY SEE
MUCH LESS RAINFALL. TEMPERATURES SHOULDN`T WARM UP TOO MUCH TODAY
DUE TO CLOUDS AND RAIN...WITH THE WARMEST READINGS LIKELY IN NH
ESPECIALLY ALONG THE CONNECTICUT RIVER VALLEY. BREEZY NORTH
NORTHEAST WINDS WILL OCCUR TODAY...MORE SO OVER MAINE THAN NH.
GENERALLY USED A BLEND OF GFS/NAM AND MET/MAV MOS GUIDANCE FOR THE
NEAR TERM FCST. USED HPC QPF TO START...THOUGH DID ADJUST
SOMEWHAT. QPF WILL RANGE FROM LESS THAN A QUARTER OF AN INCH
ACROSS THE MAINE MOUNTAINS TO NORTHERN AND WESTERN NH TO AN INCH
TO AN INCH AND A HALF OVER THE MID COAST OF MAINE.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
THE SFC LOW TRACKS INTO THE MARITIMES TONIGHT BRINGING AN END TO
THE RAIN FROM SOUTHWEST TO NORTHEAST. AREAS OF FOG WILL FORM IN
THE MOIST BOUNDARY LAYER ESPECIALLY FOR AREAS THAT SEE SOME
CLEARING AND HAD A FAIR AMOUNT OF RAINFALL. TOTAL QPF THROUGH
TONIGHT WILL RANGE FROM LESS THAN A QUARTER OF AN INCH ACROSS
NORTHERN AND WESTERN NH TO AROUND TWO INCHES OVER THE MID COAST OF
MAINE WITH SOME HIGHER AMOUNTS POSSIBLE. NOT ANTICIPATING FLOOD
ISSUES WITH THIS EVENT BUT THERE IS THE OUTSIDE CHANCE THAT IF
CLOSER TO 3 /OR MORE/ INCHES OF RAIN FALL THEN THERE MAY BE SOME
MINOR FLOOD PROBLEMS OVER THE MID COAST OF MAINE AND INTO AREAS
JUST TO THE SW...W AND N. AT THIS TIME WILL NOT PUT UP A FLOOD
WATCH. GENERALLY USED A BLEND OF NAM/GFS...MET/MAV MOS AND HPC/RFC
QPF FOR THE SHORT TERM FCST.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
WE BEGIN THE PERIOD WITH A SHORTWAVE RIDGE EXITING INTO THE
MARITIMES...AND AN UPPER LOW OVER THE GREAT LAKES SLIDING
EASTWARD INTO NEW ENGLAND. THE UPPER LOW WILL LIFT TO OUR NORTH
AND EAST EARLY NEXT WEEK...WITH A BROAD TROUGH EXTENDING ROM THE
GREAT LAKES INTO NEW ENGLAND IN ITS WAKE. THE UPSHOT OF THIS
PATTERN WILL BE THAT EXCESSIVE HEAT AND HUMIDITY WILL REMAIN WELL
TO OUR SOUTH AND WEST THROUGH THE PERIOD.
IN THE DAILIES...A SLOW-MOVING COLD FRONT APPROACHES FROM THE
GREAT LAKES LATE SUNDAY THEN EXITS THE COAST DURING MONDAY. AN
UPPER LOW WILL PROVIDE A FEW CLOUDS AND UNSETTLED WEATHER FOR
TUESDAY. A WEAK RIDGE OF HIGH PRESSURE FOLLOWS FOR WEDNESDAY.
ANOTHER DISTURBANCE WILL CROSS THE REGION THURSDAY AND FRIDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SATURDAY/...CONDITIONS WILL LOWER WITH
RAIN OVERSPREADING MUCH OF THE REGION TODAY. LOWEST CONDITIONS
OVER MORE EASTERN AND COASTAL AREAS AND HIGHEST CONDITIONS OVER
MORE NORTHERN AND WESTERN AREAS. THUS EXPECT RKD...AUG...PWM AND
PSM TO HAVE LOWEST CIG/VSBY WHILE LEB AND HIE THE HIGHEST CIG/VSBY
WITH CON IN BETWEEN. AS THE RAIN ENDS FROM SW TO NE TONIGHT EXPECT
SOME CLEARING TO FOLLOW BUT THAT WILL ALLOW FOG TO FORM...
ESPECIALLY IN AREAS THAT SEE THE MOST CLEARING BUT ALSO HAD
SIGNIFICANT AMOUNTS OF RAINFALL.
LONG TERM...
SUN PM - MON...MVFR LIKELY IN SHOWERS AND SCT TSTMS.
&&
.MARINE...
SHORT TERM /FRIDAY THROUGH SATURDAY/...WILL UPDATE TO INPUT LATEST
OBSERVED DATA RESULTING IN NO MORE THAN A FEW MINOR ADJUSTMENTS TO
THE PREVIOUS FORECAST. WILL CONTINUE THE SCA FOR THE OUTER WATERS
INTO TONIGHT AS THE SFC LOW MOVES TO THE NE ACROSS THE GULF OF
MAINE TODAY AND INTO THE MARITIMES TONIGHT. EXPECT WIND GUSTS OF
25 KT AND MAYBE EVEN UP TO 30 KT. SEAS WILL BUILD TO 5 OR 6 FT
OVER THE OPEN WATERS. WINDS LET UP AND DROP BELOW SCA LEVELS
TONIGHT. SEAS WILL BE SLOWER TO SUBSIDE AND MAY NOT DROP BELOW SCA
LEVELS UNTIL SATURDAY. HIGH PRESSURE WILL RESULT IN WINDS AND SEAS
BELOW SCA LEVELS ON SATURDAY.
LONG TERM...
SUN NIGHT - MON...WINDS AND SEAS MAY APPROACH SCA THRESHOLD.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ150-152-
154.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GAYLORD MI
621 PM EDT FRI JUL 26 2013
.SYNOPSIS...
ISSUED AT 415 PM EDT FRI JUL 26 2013
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY ADVANCE
THROUGH THE STATE...TODAY THROUGH SATURDAY. THIS SYSTEM WILL PRODUCE
A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH TONIGHT...WITH THE
BULK OF THE RAINFALL OCCURRING LATE THIS AFTERNOON AND THIS EVENING.
RAIN MAY BE HEAVY AT TIMES...PARTICULARLY OVER THE EASTERN UPPER
PENINSULA.
BEHIND THE FRONT...SUBSTANTIALLY COOLER AIR WILL SETTLE INTO THE
GREAT LAKES FOR THE UPCOMING WEEKEND KNOCKING TEMPERATURES DOWN TO
WELL BELOW NORMAL READINGS FOR LATE JULY. THIS WILL LEAD TO
ADDITIONAL SHOWERS DEVELOPING ON SATURDAY AND PERSISTING THROUGH
SUNDAY NIGHT.
&&
.UPDATE...
ISSUED AT 616 PM EDT FRI JUL 26 2013
CHANGES THIS HOUR: GOING FORECAST DOING JUST FINE AS OF THIS
WRITING...WITH SOME COSMETIC ADJUSTMENTS TO POPS/WEATHER AS RAIN
HAS JUST ABOUT REACHED THE ENTIRE FORECAST AREA. TEMPS HAVE FALLEN
NICELY WITH ARRIVAL OF RAINFALL..SO HAVE TRENDED NEAR TERM
TEMPERATURES DOWN AS WELL.
SEVERE THREAT HAS PRETTY MUCH ENDED WITH MUCAPES DROPPING CWA-WIDE
OVER THE PAST 3 HOURS. LIGHTNING STRIKES ARE FOLLOWING SUIT AS OF
THIS WRITING...BUT SOME EMBEDDED THUNDER CERTAINLY LIKELY THROUGH
THE EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
SHOWERS AND STORMS ON THE UPSWING THIS AFTERNOON ACROSS THE NORTH
WOODS. WATER VAPOR DEFINITELY HELPS EXPLAIN PART OF THE REASON...WITH
AN UNSEASONABLY STRONG SHORTWAVE TROUGH GOING NEGATIVE TILT BACK
ACROSS THE WESTERN LAKES. NICE MID LEVEL SPEED MAX ALSO NOTED...WITH
CORE OF 50+ KNOT H5 WINDS ROUNDING BASE OF TROUGH INTO SOUTHWEST
WISCONSIN. DEEP LAYER DYNAMICS INTERACTING WITH IN-PLACE RESPECTABLY
MOIST AIRMASS (PWAT VALUES PER RAP GUIDANCE NEAR 1.5 INCHES) HELPING
INDUCE CONVECTIVE DEVELOPMENT. MAIN LINE OF STORMS TIED TO
WISCONSIN/CENTRAL UPPER MICHIGAN COLD FRONT/FRONTAL WAVE WHERE LOW
LEVEL CONVERGENCE/DEEP LAYER DYNAMICS ARE BETTER JUXTAPOSED. MORE
SCATTERED SHOWERS AND STORMS BREAKING OUT ACROSS NORTHERN MICHIGAN
AS SUFFICIENT ML CAPE DEVELOPMENT (UPWARDS OF 500 J/KG) AND OBVIOUS
COOLING OF EARLIER H8-H7 WARM NOSE HAS TIPPED THE SCALE TO MOIST
CONVECTIVE DEVELOPMENT. SO FAR...THINGS HAVE BEEN BEHAVING
THEMSELVES...WITH JUST SOME LOCALLY HEAVY RAIN UNDER THE HEAVIER
CELLS. APPEARS A MUCH NEEDED WIDESPREAD RAIN IS IN THE OFFING THIS
EVENING AS ABOVE DYNAMICS/MOISTURE AXIS SPREAD EAST. FORECAST
CONCERNS CENTER ON SUCH...SPECIFICALLY TIMING OF SHOWERS AND STORMS
AND SEVERE WEATHER POTENTIAL.
UPSCALE GROWTH WILL CONTINUE WITH SHOWERS/STORMS AS DEEP LAYER
DYNAMICS ONLY INCREASE HEADING INTO LATER THIS AFTERNOON AND
EVENING. COLD FRONT EXPECTED TO GET THE BOOT EAST AS MID LEVEL
SUPPORT DOES THE SAME...AND WILL SIMPLY FOLLOW IT AND BEST UPWARD QG
SUPPORT FOR SHOWER/STORM TIMING. EXPECT ALL AREAS TO GET WET...WITH
THE HEAVIEST RAINS EXPECTED ACROSS FAR NORTHWEST LOWER AND EASTERN
UPPER (LOCAL AMOUNTS IN EXCESS OF AN INCH). MAIN LINE OF ACTIVITY
EXPECTED TO SWEEP EAST THIS EVENING...EXITING OFF THE SUNRISE SIDE
DURING THE EARLY MORNING. TEMPORAL DETAIL ACCOUNTS FOR SUCH...USING
CATEGORICAL COVERAGE FOR SPATIAL PURPOSES. NOT OVERLY ENTHUSED ABOUT
SEVERE POTENTIAL...WITH ML CAPE SOMEWHAT ON THE LEAN SIDE...AND
SHOULD CONTINUE TO REMAIN SO. DEEP LAYER EFFECTIVE SHEAR INCREASES
TO OVER 30 KNOTS...WITH 40 KNOT CORE SLIDING ACROSS EASTERN UPPER
LATE THIS AFTERNOON. CANNOT RULE OUT AN ISOLATED SEVERE WIND
GUST/MARGINALLY SEVERE HAILER WITH THE STRONGEST ACTIVITY...BUT A
WIDESPREAD SEVERE EVENT IS NOT EXPECTED. INTERESTINGLY...BACKED LAKE
INDUCED FLOW ACROSS THE TIP THE MITT/NORTHEAST LOWER/EASTERN UPPER
HAS RESULTED IN A TOUCH BETTER STORM ORGANIZATION WITH EVEN SOME
HINTS OF LOW-TOPPED SUPERCELLS. SPOTTER REPORTS NEGATIVE...
HOWEVER...WITH JUST LOCALLY HEAVY RAIN REPORTED WITH THESE CELLS.
WILL DEFINITELY CONTINUE TO MONITOR. POST-FRONTAL LOW LEVEL MOISTURE
SHOULD KEEP RATHER CLOUDY CONDITIONS THROUGH THE EARLY MORNING.
INITIAL SHOT OF CAA NOT OVERLY IMPRESSIVE...WITH LOWS BY SUN-UP
RANGING FROM THE 50S WEST...TO LOWER 60S ALONG NORTHEAST LOWER
COASTLINE.
DRY SLOT CONTINUES INTO SATURDAY MORNING AS MID LEVEL LOW PRESSURE
PINWHEELS INTO NORTHERN WISCONSIN. OFF THE DECK PROFILES REMAIN
RATHER DRY RIGHT THROUGH THE DAY...WITH DEEPER MOISTURE AXIS REMAIN
TO OUR WEST. CAA DROPS H8 TEMPERATURES INTO THE MID SINGLE
DIGITS...MORE THAN COLD ENOUGH TO ENTICE A LAKE RESPONSE (GULP!).
THAT SAID...NOT REALLY ENTHUSED ABOUT LAKE POTENTIAL...WITH DEEP
MOISTURE REMAINING UPSTREAM AND RATHER WEAK/DISORGANIZED LOW LEVEL
WIND FIELDS. MAY SEE SOME POP-UP ACTIVITY DURING THE AFTERNOON WITH
LAND MASS DESTABILIZATION...ESPECIALLY IF THE MORE AGGRESSIVE
NAM-WRF DEPICTIONS ARE REALIZED. HAVE TRENDED FORECAST HEAVILY IN
THIS DIRECTION...FOCUSING "BEST" SHOWER POTENTIAL TO
CLIMATOLOGICALLY FAVORED NORTHEAST LOWER WHERE LOW LEVEL CONVERGENCE
WILL BE MAXIMIZED. THUNDER THREAT NOT INCLUDED...DISCOUNTING THE NAM
AT THIS TIME. LESS SHOWER ACTIVITY LIKELY TO RESULT IN SLIGHTLY WARMER
TEMPERATURES. HAVE NUDGED READINGS UP A FEW DEGREES ACROSS THE
BOARD...BUT NO DOUBT TEMPERATURES WILL BE SEVERAL DEGREES BELOW LATE
JULY NORMALS.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
A RATHER BLOCKED LOOK REMAINS TO THE OVERALL HEMISPHERIC
PATTERN...WITH REX BLOCKING FOUND OVER THE NORTH CENTRAL
PACIFIC...AND A LARGE RIDGE OF HIGH PRESSURE FOUND AROUND IN THE
NORTH ATLANTIC /40W/. IN BETWEEN WE ARE LEFT WITH MEAN TROUGHING
OVER THE GREAT LAKES...WITH A VIGOROUS SHORTWAVE SEEN ON WATER VAPOR
IMAGERY DROPPING INTO THE UPPER MISSISSIPPI VALLEY THAT WILL HAVE
IMPLICATIONS FOR OUR WEEKEND WEATHER. LOOKING AHEAD...THE PATTERN
APPEARS TO BE VERY SLOW TO BREAK DOWN OVER THE NEXT SEVERAL
DAYS...WITH NORTH ATLANTIC HIGH PROGGED TO ACTUALLY RETROGRADE A BIT
BY EARLY NEXT WEEK...BEFORE SLOWLY BREAKING DOWN AND BECOMING
INCREASINGLY PROGRESSIVE LATER NEXT WEEK. THIS IDEA IS REFLECTED IN
THE LATEST NAO ENSEMBLE FORECASTS...MAINTAINING AN OVERALL NEGATIVE
PHASE/BLOCKED/COOLISH PATTERN UNTIL THE BEGINNING OF AUGUST BEFORE
TRENDING MORE NEUTRAL.
SATURDAY NIGHT INTO SUNDAY...MIGHT AS WELL RIP THE JULY AND AUGUST
PAGE RIGHT OFF THE CALENDAR...AS PATTERN FOR THE WEEKEND WILL BE
NOTHING SHORT OF FALL-LIKE. FIRST OFF..APPROACHING SHORT WAVE IS
SCHEDULED TO DROP INTO THE GREAT LAKES AND BECOME CLOSED OFF BY
SUNDAY AS A 555 DM LOW /YIKES!/. THE 500 MB HEIGHT ANOMALY IS AROUND
3 SD BELOW NORMAL FOR THIS TIME OF YEAR PER GEFS STANDARDIZED
ANOMALIES. CORE OF COLDEST AIR LOOKS TO PASS DIRECTLY OVER THE
CWA...WITH H85 TEMPS FALLING AOB 5C DURING THE DAY SUNDAY. BASED
ON PATTERN RECOGNITION AND ABUNDANCE OF H85-H7 MOISTURE PRESENT
DURING THE DAY ON SUNDAY...LOOKING LIKE A PRIME SETUP FOR SOME
INSTABILITY SHOWERS...ESPECIALLY DURING THE AFTERNOON IF WE CAN GET
JUST ENOUGH INSOLATION...DESPITE OVERALL CLOUDY LOOK TO THE
FORECAST. IN ADDITION...ANY SUBTLE VORT MAX ROUNDING MAIN LOW WILL
ALSO CREATE A THREAT FOR SHOWERS. REMOVED THUNDER FROM THE FORECAST
FOR INLAND SPOTS AS I AM NOT CONFIDENT THAT WE WILL HAVE SUFFICIENT
LAPSE RATES AND INSOLATION TO PRODUCE ANY APPRECIABLE CAPE AND
CONVECTIVE DEPTH TO PRODUCE THUNDER. COULD FORESEE SOME GRAUPEL
BEING MIXED GIVEN THE AMOUNT OF COLD AIR ALOFT...BUT TOO SOON TO
INCLUDE SUCH SMALL/MESOSCALE DETAILS IN THE FORECAST ATTM. HIGH
TEMPS ON SUNDAY WILL STRUGGLE TO BREAK THE 60 DEGREE MARK BASED ON
THIS VERY COOL PATTERN...AN KNOCKED OFF A DEGREE OR TWO FROM THE
INHERITED HIGH TEMPERATURES.
OF BIGGER CONCERN IS THE LAKE EFFECT RAIN POTENTIAL /YES...LAKE
EFFECT/...LAKE TEMPS IN THE MID TO UPPER 60S AND AFOREMENTIONED H85
TEMPS WILL CREATE DELTA T`S AROUND 13 TO 18C. THERE IS A DISCREPANCY
BETWEEN THE GUIDANCE OF THE MAIN 1000-850 MB FLOW SUNDAY
NIGHT...WITH THE GFS SUGGESTING MORE OF A SOUTHERLY FLOW FOR NW
LOWER...BUT THE CONSENSUS OFF THE NAM/GEM/ECMWF IS FOR A WEST TO
NORTHWEST ONSHORE WIND DIRECTION...ALBEIT FAIRLY LIGHT. WOULD NOT BE
SURPRISED TO SEE SOME LAKE EFFECT THUNDER WITH LAKE-INDUCED CAPE
VALUES HOVERING AROUND 750 J/KG BASED OFF NAM AND SREF BUFKIT
SOUNDINGS...AND LEFT SLT CHC THUNDER FOR LAKE EFFECT REGIONS THROUGH
SUNDAY. GIVEN THE STRONG INSTABILITY OVER THE LAKES WITH THE UPPER
LOW...ALSO LOOKING LAKE A GOOD SETUP FOR WATERSPOUTS OVER ALL OF THE
GREAT LAKES THROUGH SUNDAY.
SUNDAY NIGHT INTO MONDAY...THE UPPER LOW WILL BE SLOW TO MOVE OFF TO
THE EAST...ALONG WITH THE CORE OF DEEPEST MOISTURE AND BEST FORCING.
DELTA T`S WILL STILL REMAIN FAVORABLE FOR SOME LAKE EFFECT RAIN
SHOWERS FOR NORTHWEST LOWER...ALONG WITH WATERSPOUTS FOR THE GREAT
LAKES THROUGH SUNDAY NIGHT. DRIER MID LEVEL AIR WILL FILTER IN LATE
SUNDAY NIGHT INTO MONDAY...ALONG WITH WEAK SURFACE HIGH PRESSURE
SETTLING INTO THE WESTERN GREAT LAKES. SKIES WILL GRADUALLY CLEAR
FROM WEST TO EAST MONDAY...WITH HIGH TEMPERATURES EXPECTED TO
REBOUND INTO THE MIDDLE 60S TO NEAR 70...ASSUMING SUFFICIENT
SUNSHINE BY AFTERNOON.
MONDAY NIGHT THROUGH FRIDAY...CUTOFF LOW PROGGED TO BE CLEAR OF THE
REGION BY MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN THE GREAT
LAKES THROUGH TUESDAY NIGHT. SHORT WAVE RIDGING IS EXPECTED TO
SETTLE IN OVERHEAD UNDER A WEST NORTHWEST UPPER LEVEL FLOW REGIME.
THE REGION SHOULD SEE A GOOD DEAL OF SUNSHINE...WITH NEAR TO
SLIGHTLY BELOW NORMAL READINGS FOR TUESDAY ALONG WITH SOME COOL
NIGHTS EXPECTED MONDAY AND TUESDAY NIGHT. THE NEXT SHORTWAVE IN THE
WNW FLOW REGIME DROPS INTO THE GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY...AND THE ASSOCIATED LOW MOVING THROUGH SOUTHERN ONTARIO
WILL DRAG A COLD FRONT THROUGH THE CWA DURING THIS TIMEFRAME. THIS
WILL PROVIDE THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
REGION. A SECONDARY STRONGER SHORT WAVE LOOKS TO FOLLOW QUICK ON ITS
HEELS BY FRIDAY. ECMWF/GFS DIFFER ON THE TIMING AND PLACEMENT OF THE
SECOND WAVE...WITH THE NEW 12Z ECMWF SLOWER AND FURTHER NORTH WITH
THE WAVE. WILL HOLD OFF ADDING POPS FOR FRIDAY FOR NOW...AS I DON`T
WANT TO CLUTTER UP THE EXTENDED TOO MUCH WITH AN ALREADY FAIRLY BUSY
WEATHER PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 136 PM EDT FRI JUL 26 2013
COLD FRONT APPROACHING THE AREA WILL CONTINUE TO GENERATE SHOWERS
AND STORMS...THE MAIN CORE OF WHICH SHOULD MOVE ACROSS THE TAF
SITES LATER THIS AFTERNOON INTO EARLY EVENING. WOULD EXPECT
TEMPORARY IFR CONDITIONS AS THIS OCCURS. WILL ALSO NEED TO WATCH
FOR GUSTY CONVECTION INDUCED WINDS AS THEY MOVE ACROSS. POST-
FRONTAL LOW CLOUDS EXPECTED...BUT LOOK TO REMAIN IN MVFR
CATEGORY. MVFR CLOUDS CONTINUE SATURDAY...WITH SOME VERY LOW END
SHOWER POTENTIAL. GUSTY SOUTHWEST WINDS EXPECTED TO BECOME WEST TO
WNW TONIGHT AND SATURDAY AFTER FRONTAL PASSAGE.
&&
.MARINE...
ISSUED AT 415 PM EDT FRI JUL 26 2013
MARINE...GUSTY PRE-FRONTAL SOUTHWEST WINDS TO CONTINUE THROUGH THIS
AFTERNOON...MAINLY IMPACTING NORTHERN LAKE MICHIGAN. PRESSURE
GRADIENT SLACKENS OVERNIGHT...DESPITE COLD FRONTAL PASSAGE. GUSTY
THUNDERSTORM WINDS EXPECTED ALONG THIS FRONT...ESPECIALLY THIS
EVENING. MAINLY LIGHT WEST WINDS EXPECTED THROUGH THIS WEEKEND.
WATERSPOUT POTENTIAL WILL BE ON THE INCREASE THIS WEEKEND AS
UNSEASONABLY STRONG UPPER LEVEL DISTURBANCE SLOWLY ROTATES ACROSS
THE NORTHERN LAKES. PERIODIC SHOWERS ALSO EXPECTED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ344>346.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...NS
AVIATION...MB
MARINE...MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
418 PM EDT FRI JUL 26 2013
.SYNOPSIS...
ISSUED AT 415 PM EDT FRI JUL 26 2013
LOW PRESSURE AND AN ASSOCIATED COLD FRONT WILL SLOWLY ADVANCE
THROUGH THE STATE...TODAY THROUGH SATURDAY. THIS SYSTEM WILL PRODUCE
A FEW ROUNDS OF SHOWERS AND THUNDERSTORMS THROUGH TONIGHT...WITH THE
BULK OF THE RAINFALL OCCURRING LATE THIS AFTERNOON AND THIS EVENING.
RAIN MAY BE HEAVY AT TIMES...PARTICULARLY OVER THE EASTERN UPPER
PENINSULA.
BEHIND THE FRONT...SUBSTANTIALLY COOLER AIR WILL SETTLE INTO THE
GREAT LAKES FOR THE UPCOMING WEEKEND KNOCKING TEMPERATURES DOWN TO
WELL BELOW NORMAL READINGS FOR LATE JULY. THIS WILL LEAD TO
ADDITIONAL SHOWERS DEVELOPING ON SATURDAY AND PERSISTING THROUGH
SUNDAY NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
SHOWERS AND STORMS ON THE UPSWING THIS AFTERNOON ACROSS THE NORTH
WOODS. WATER VAPOR DEFINITELY HELPS EXPLAIN PART OF THE REASON...WITH
AN UNSEASONABLY STRONG SHORTWAVE TROUGH GOING NEGATIVE TILT BACK
ACROSS THE WESTERN LAKES. NICE MID LEVEL SPEED MAX ALSO NOTED...WITH
CORE OF 50+ KNOT H5 WINDS ROUNDING BASE OF TROUGH INTO SOUTHWEST
WISCONSIN. DEEP LAYER DYNAMICS INTERACTING WITH IN-PLACE RESPECTABLY
MOIST AIRMASS (PWAT VALUES PER RAP GUIDANCE NEAR 1.5 INCHES) HELPING
INDUCE CONVECTIVE DEVELOPMENT. MAIN LINE OF STORMS TIED TO
WISCONSIN/CENTRAL UPPER MICHIGAN COLD FRONT/FRONTAL WAVE WHERE LOW
LEVEL CONVERGENCE/DEEP LAYER DYNAMICS ARE BETTER JUXTAPOSED. MORE
SCATTERED SHOWERS AND STORMS BREAKING OUT ACROSS NORTHERN MICHIGAN
AS SUFFICIENT ML CAPE DEVELOPMENT (UPWARDS OF 500 J/KG) AND OBVIOUS
COOLING OF EARLIER H8-H7 WARM NOSE HAS TIPPED THE SCALE TO MOIST
CONVECTIVE DEVELOPMENT. SO FAR...THINGS HAVE BEEN BEHAVING
THEMSELVES...WITH JUST SOME LOCALLY HEAVY RAIN UNDER THE HEAVIER
CELLS. APPEARS A MUCH NEEDED WIDESPREAD RAIN IS IN THE OFFING THIS
EVENING AS ABOVE DYNAMICS/MOISTURE AXIS SPREAD EAST. FORECAST
CONCERNS CENTER ON SUCH...SPECIFICALLY TIMING OF SHOWERS AND STORMS
AND SEVERE WEATHER POTENTIAL.
UPSCALE GROWTH WILL CONTINUE WITH SHOWERS/STORMS AS DEEP LAYER
DYNAMICS ONLY INCREASE HEADING INTO LATER THIS AFTERNOON AND
EVENING. COLD FRONT EXPECTED TO GET THE BOOT EAST AS MID LEVEL
SUPPORT DOES THE SAME...AND WILL SIMPLY FOLLOW IT AND BEST UPWARD QG
SUPPORT FOR SHOWER/STORM TIMING. EXPECT ALL AREAS TO GET WET...WITH
THE HEAVIEST RAINS EXPECTED ACROSS FAR NORTHWEST LOWER AND EASTERN
UPPER (LOCAL AMOUNTS IN EXCESS OF AN INCH). MAIN LINE OF ACTIVITY
EXPECTED TO SWEEP EAST THIS EVENING...EXITING OFF THE SUNRISE SIDE
DURING THE EARLY MORNING. TEMPORAL DETAIL ACCOUNTS FOR SUCH...USING
CATEGORICAL COVERAGE FOR SPATIAL PURPOSES. NOT OVERLY ENTHUSED ABOUT
SEVERE POTENTIAL...WITH ML CAPE SOMEWHAT ON THE LEAN SIDE...AND
SHOULD CONTINUE TO REMAIN SO. DEEP LAYER EFFECTIVE SHEAR INCREASES
TO OVER 30 KNOTS...WITH 40 KNOT CORE SLIDING ACROSS EASTERN UPPER
LATE THIS AFTERNOON. CANNOT RULE OUT AN ISOLATED SEVERE WIND
GUST/MARGINALLY SEVERE HAILER WITH THE STRONGEST ACTIVITY...BUT A
WIDESPREAD SEVERE EVENT IS NOT EXPECTED. INTERESTINGLY...BACKED LAKE
INDUCED FLOW ACROSS THE TIP THE MITT/NORTHEAST LOWER/EASTERN UPPER
HAS RESULTED IN A TOUCH BETTER STORM ORGANIZATION WITH EVEN SOME
HINTS OF LOW-TOPPED SUPERCELLS. SPOTTER REPORTS NEGATIVE...
HOWEVER...WITH JUST LOCALLY HEAVY RAIN REPORTED WITH THESE CELLS.
WILL DEFINITELY CONTINUE TO MONITOR. POST-FRONTAL LOW LEVEL MOISTURE
SHOULD KEEP RATHER CLOUDY CONDITIONS THROUGH THE EARLY MORNING.
INITIAL SHOT OF CAA NOT OVERLY IMPRESSIVE...WITH LOWS BY SUN-UP
RANGING FROM THE 50S WEST...TO LOWER 60S ALONG NORTHEAST LOWER
COASTLINE.
DRY SLOT CONTINUES INTO SATURDAY MORNING AS MID LEVEL LOW PRESSURE
PINWHEELS INTO NORTHERN WISCONSIN. OFF THE DECK PROFILES REMAIN
RATHER DRY RIGHT THROUGH THE DAY...WITH DEEPER MOISTURE AXIS REMAIN
TO OUR WEST. CAA DROPS H8 TEMPERATURES INTO THE MID SINGLE
DIGITS...MORE THAN COLD ENOUGH TO ENTICE A LAKE RESPONSE (GULP!).
THAT SAID...NOT REALLY ENTHUSED ABOUT LAKE POTENTIAL...WITH DEEP
MOISTURE REMAINING UPSTREAM AND RATHER WEAK/DISORGANIZED LOW LEVEL
WIND FIELDS. MAY SEE SOME POP-UP ACTIVITY DURING THE AFTERNOON WITH
LAND MASS DESTABILIZATION...ESPECIALLY IF THE MORE AGGRESSIVE
NAM-WRF DEPICTIONS ARE REALIZED. HAVE TRENDED FORECAST HEAVILY IN
THIS DIRECTION...FOCUSING "BEST" SHOWER POTENTIAL TO
CLIMATOLOGICALLY FAVORED NORTHEAST LOWER WHERE LOW LEVEL CONVERGENCE
WILL BE MAXIMIZED. THUNDER THREAT NOT INCLUDED...DISCOUNTING THE NAM
AT THIS TIME. LESS SHOWER ACTIVITY LIKELY TO RESULT IN SLIGHTLY WARMER
TEMPERATURES. HAVE NUDGED READINGS UP A FEW DEGREES ACROSS THE
BOARD...BUT NO DOUBT TEMPERATURES WILL BE SEVERAL DEGREES BELOW LATE
JULY NORMALS.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 415 PM EDT FRI JUL 26 2013
A RATHER BLOCKED LOOK REMAINS TO THE OVERALL HEMISPHERIC
PATTERN...WITH REX BLOCKING FOUND OVER THE NORTH CENTRAL
PACIFIC...AND A LARGE RIDGE OF HIGH PRESSURE FOUND AROUND IN THE
NORTH ATLANTIC /40W/. IN BETWEEN WE ARE LEFT WITH MEAN TROUGHING
OVER THE GREAT LAKES...WITH A VIGOROUS SHORTWAVE SEEN ON WATER VAPOR
IMAGERY DROPPING INTO THE UPPER MISSISSIPPI VALLEY THAT WILL HAVE
IMPLICATIONS FOR OUR WEEKEND WEATHER. LOOKING AHEAD...THE PATTERN
APPEARS TO BE VERY SLOW TO BREAK DOWN OVER THE NEXT SEVERAL
DAYS...WITH NORTH ATLANTIC HIGH PROGGED TO ACTUALLY RETROGRADE A BIT
BY EARLY NEXT WEEK...BEFORE SLOWLY BREAKING DOWN AND BECOMING
INCREASINGLY PROGRESSIVE LATER NEXT WEEK. THIS IDEA IS REFLECTED IN
THE LATEST NAO ENSEMBLE FORECASTS...MAINTAINING AN OVERALL NEGATIVE
PHASE/BLOCKED/COOLISH PATTERN UNTIL THE BEGINNING OF AUGUST BEFORE
TRENDING MORE NEUTRAL.
SATURDAY NIGHT INTO SUNDAY...MIGHT AS WELL RIP THE JULY AND AUGUST
PAGE RIGHT OFF THE CALENDAR...AS PATTERN FOR THE WEEKEND WILL BE
NOTHING SHORT OF FALL-LIKE. FIRST OFF..APPROACHING SHORT WAVE IS
SCHEDULED TO DROP INTO THE GREAT LAKES AND BECOME CLOSED OFF BY
SUNDAY AS A 555 DM LOW /YIKES!/. THE 500 MB HEIGHT ANOMALY IS AROUND
3 SD BELOW NORMAL FOR THIS TIME OF YEAR PER GEFS STANDARDIZED
ANOMALIES. CORE OF COLDEST AIR LOOKS TO PASS DIRECTLY OVER THE
CWA...WITH H85 TEMPS FALLING AOB 5C DURING THE DAY SUNDAY. BASED
ON PATTERN RECOGNITION AND ABUNDANCE OF H85-H7 MOISTURE PRESENT
DURING THE DAY ON SUNDAY...LOOKING LIKE A PRIME SETUP FOR SOME
INSTABILITY SHOWERS...ESPECIALLY DURING THE AFTERNOON IF WE CAN GET
JUST ENOUGH INSOLATION...DESPITE OVERALL CLOUDY LOOK TO THE
FORECAST. IN ADDITION...ANY SUBTLE VORT MAX ROUNDING MAIN LOW WILL
ALSO CREATE A THREAT FOR SHOWERS. REMOVED THUNDER FROM THE FORECAST
FOR INLAND SPOTS AS I AM NOT CONFIDENT THAT WE WILL HAVE SUFFICIENT
LAPSE RATES AND INSOLATION TO PRODUCE ANY APPRECIABLE CAPE AND
CONVECTIVE DEPTH TO PRODUCE THUNDER. COULD FORESEE SOME GRAUPEL
BEING MIXED GIVEN THE AMOUNT OF COLD AIR ALOFT...BUT TOO SOON TO
INCLUDE SUCH SMALL/MESOSCALE DETAILS IN THE FORECAST ATTM. HIGH
TEMPS ON SUNDAY WILL STRUGGLE TO BREAK THE 60 DEGREE MARK BASED ON
THIS VERY COOL PATTERN...AN KNOCKED OFF A DEGREE OR TWO FROM THE
INHERITED HIGH TEMPERATURES.
OF BIGGER CONCERN IS THE LAKE EFFECT RAIN POTENTIAL /YES...LAKE
EFFECT/...LAKE TEMPS IN THE MID TO UPPER 60S AND AFOREMENTIONED H85
TEMPS WILL CREATE DELTA T`S AROUND 13 TO 18C. THERE IS A DISCREPANCY
BETWEEN THE GUIDANCE OF THE MAIN 1000-850 MB FLOW SUNDAY
NIGHT...WITH THE GFS SUGGESTING MORE OF A SOUTHERLY FLOW FOR NW
LOWER...BUT THE CONSENSUS OFF THE NAM/GEM/ECMWF IS FOR A WEST TO
NORTHWEST ONSHORE WIND DIRECTION...ALBEIT FAIRLY LIGHT. WOULD NOT BE
SURPRISED TO SEE SOME LAKE EFFECT THUNDER WITH LAKE-INDUCED CAPE
VALUES HOVERING AROUND 750 J/KG BASED OFF NAM AND SREF BUFKIT
SOUNDINGS...AND LEFT SLT CHC THUNDER FOR LAKE EFFECT REGIONS THROUGH
SUNDAY. GIVEN THE STRONG INSTABILITY OVER THE LAKES WITH THE UPPER
LOW...ALSO LOOKING LAKE A GOOD SETUP FOR WATERSPOUTS OVER ALL OF THE
GREAT LAKES THROUGH SUNDAY.
SUNDAY NIGHT INTO MONDAY...THE UPPER LOW WILL BE SLOW TO MOVE OFF TO
THE EAST...ALONG WITH THE CORE OF DEEPEST MOISTURE AND BEST FORCING.
DELTA T`S WILL STILL REMAIN FAVORABLE FOR SOME LAKE EFFECT RAIN
SHOWERS FOR NORTHWEST LOWER...ALONG WITH WATERSPOUTS FOR THE GREAT
LAKES THROUGH SUNDAY NIGHT. DRIER MID LEVEL AIR WILL FILTER IN LATE
SUNDAY NIGHT INTO MONDAY...ALONG WITH WEAK SURFACE HIGH PRESSURE
SETTLING INTO THE WESTERN GREAT LAKES. SKIES WILL GRADUALLY CLEAR
FROM WEST TO EAST MONDAY...WITH HIGH TEMPERATURES EXPECTED TO
REBOUND INTO THE MIDDLE 60S TO NEAR 70...ASSUMING SUFFICIENT
SUNSHINE BY AFTERNOON.
MONDAY NIGHT THROUGH FRIDAY...CUTOFF LOW PROGGED TO BE CLEAR OF THE
REGION BY MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN THE GREAT
LAKES THROUGH TUESDAY NIGHT. SHORT WAVE RIDGING IS EXPECTED TO
SETTLE IN OVERHEAD UNDER A WEST NORTHWEST UPPER LEVEL FLOW REGIME.
THE REGION SHOULD SEE A GOOD DEAL OF SUNSHINE...WITH NEAR TO
SLIGHTLY BELOW NORMAL READINGS FOR TUESDAY ALONG WITH SOME COOL
NIGHTS EXPECTED MONDAY AND TUESDAY NIGHT. THE NEXT SHORTWAVE IN THE
WNW FLOW REGIME DROPS INTO THE GREAT LAKES TUESDAY NIGHT INTO
WEDNESDAY...AND THE ASSOCIATED LOW MOVING THROUGH SOUTHERN ONTARIO
WILL DRAG A COLD FRONT THROUGH THE CWA DURING THIS TIMEFRAME. THIS
WILL PROVIDE THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE
REGION. A SECONDARY STRONGER SHORT WAVE LOOKS TO FOLLOW QUICK ON ITS
HEELS BY FRIDAY. ECMWF/GFS DIFFER ON THE TIMING AND PLACEMENT OF THE
SECOND WAVE...WITH THE NEW 12Z ECMWF SLOWER AND FURTHER NORTH WITH
THE WAVE. WILL HOLD OFF ADDING POPS FOR FRIDAY FOR NOW...AS I DON`T
WANT TO CLUTTER UP THE EXTENDED TOO MUCH WITH AN ALREADY FAIRLY BUSY
WEATHER PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 136 PM EDT FRI JUL 26 2013
COLD FRONT APPROACHING THE AREA WILL CONTINUE TO GENERATE SHOWERS
AND STORMS...THE MAIN CORE OF WHICH SHOULD MOVE ACROSS THE TAF
SITES LATER THIS AFTERNOON INTO EARLY EVENING. WOULD EXPECT
TEMPORARY IFR CONDITIONS AS THIS OCCURS. WILL ALSO NEED TO WATCH
FOR GUSTY CONVECTION INDUCED WINDS AS THEY MOVE ACROSS. POST-
FRONTAL LOW CLOUDS EXPECTED...BUT LOOK TO REMAIN IN MVFR
CATEGORY. MVFR CLOUDS CONTINUE SATURDAY...WITH SOME VERY LOW END
SHOWER POTENTIAL. GUSTY SOUTHWEST WINDS EXPECTED TO BECOME WEST TO
WNW TONIGHT AND SATURDAY AFTER FRONTAL PASSAGE.
&&
.MARINE...
ISSUED AT 415 PM EDT FRI JUL 26 2013
MARINE...GUSTY PRE-FRONTAL SOUTHWEST WINDS TO CONTINUE THROUGH THIS
AFTERNOON...MAINLY IMPACTING NORTHERN LAKE MICHIGAN. PRESSURE
GRADIENT SLACKENS OVERNIGHT...DESPITE COLD FRONTAL PASSAGE. GUSTY
THUNDERSTORM WINDS EXPECTED ALONG THIS FRONT...ESPECIALLY THIS
EVENING. MAINLY LIGHT WEST WINDS EXPECTED THROUGH THIS WEEKEND.
WATERSPOUT POTENTIAL WILL BE ON THE INCREASE THIS WEEKEND AS
UNSEASONABLY STRONG UPPER LEVEL DISTURBANCE SLOWLY ROTATES ACROSS
THE NORTHERN LAKES. PERIODIC SHOWERS ALSO EXPECTED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ344>346.
LS...NONE.
&&
$$
SYNOPSIS...KB
SHORT TERM...MB
LONG TERM...NS
AVIATION...MB
MARINE...MB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1230 PM EDT FRI JUL 26 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 AM EDT FRI JUL 26 2013
ANOTHER SHOT OF COLDER AIR IS HEADED TOWARD LOWER MICHIGAN THIS
WEEKEND. A STRONG COLD FRONT WILL MOVE THROUGH THE AREA BRINGING
SHOWERS AND THUNDERSTORMS AND PERHAPS WATERSPOUTS OVER LAKE
MICHIGAN. HIGH TEMPERATURES IN THE 60S ARE EXPECTED THIS WEEKEND
BEFORE SLOWLY CLIMBING BACK TO THE 80S BY THE MIDDLE OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1114 AM EDT FRI JUL 26 2013
INCREASED POPS FOR THE AFTERNOON. SATELLITE IMAGERY SHOWS COOLING
CLOUD TOPS AND A BAROCLINIC LEAF IN WISCONSIN ASSOCIATED WITH THE
DEVELOPING WAVE. THIS SYSTEM IS DRAWING IN HIGHER PRECIPITABLE
WATER FROM THE SOUTH WITH VALUES IN MI EXPECTED TO CLIMB UP TO
OVER 1.5 INCHES. THIS IS ABUNDANT MOISTURE FOR THIS AIRMASS. GIVEN
THE FORCING WITH THE WAVE MOVING IN THIS AFTERNOON...THE
PRECIPITATION SHOULD CONTINUE TO GROW.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 330 AM EDT FRI JUL 26 2013
FORECAST CONCERNS DEAL WITH CONVECTIVE TRENDS THROUGH THE PERIOD.
A DEEP UPPER TROUGH WILL ROTATE INTO THE GREAT LAKES THIS WEEKEND.
THE SFC LOW CURRENTLY OVER MINNESOTA WILL MOVE THROUGH LOWER
MICHIGAN SATURDAY MORNING DRAGGING A STRONG COLD FRONT WITH IT.
AHEAD OF THE LOW WE/LL LIKELY SEE SHOWERS AND THUNDERSTORMS DEVELOP.
DECENT DYNAMICS COME TOGETHER THIS AFTERNOON NORTHWEST OF A MUSKEGON
TO CLARE LINE. PRETTY STRONG DPVA COUPLED WITH MUCAPE AROUND 1500
J/KG...A 30 KT LLJ...AND BULK SHEAR NEAR 45 KTS SUGGEST THE
POTENTIAL FOR SOME CONVECTIVE ORGANIZATION. A FEW OF THE STORMS THIS
AFTERNOON COULD BE ON THE STRONG SIDE OVER THE NRN CWA. INVERTED V
SOUNDINGS POINT TOWARD WIND AS THE MAIN THREAT TODAY. AS PWATS CLIMB
TO AN INCH AND A HALF THIS AFTERNOON WE COULD SEE SOME HEAVY
DOWNPOURS TOO.
SHORT RANGE MODELS ARE IN PRETTY GOOD AGREEMENT PUSHING THE COLD
FRONT THROUGH SATURDAY MORNING. WE/LL KEEP THE SHOWERS AND STORMS
GOING THROUGH THE DAY. SATURDAY AFTERNOON COULD SEE A FEW STRONG
STORMS TOO...THIS TIME EAST OF US-127. THE COLD FRONT SHOULD BE IN
THE ERN CWA SATURDAY AFTERNOON. WE/LL HAVE A NARROW WINDOW WHERE
SOME STRONG DYNAMICS COME TOGETHER. MUCAPE AROUND 1500 J/KG/LI/S
NEAR -4C/BULK SHEAR 35-40 KTS WILL BE AIDED BY THE COLD POOL AT H5
MOVING INTO THE AREA.
THE COLD FRONT WILL PUSH THROUGH THE CWA BY LATE SATURDAY.
TEMPERATURES WILL BE WELL BELOW NORMAL SATURDAY AND SUNDAY. GIVEN
LAKE DELTA T/S IN THE UPPER TEENS SATURDAY NIGHT AND SUNDAY LAKE
EFFECT RAIN SHOWERS LOOKS VERY POSSIBLE.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 330 AM EDT FRI JUL 26 2013
THE UNSEASONABLY COLD WEATHER OVER THE WEEKEND WILL COME TO AN END
ON MONDAY AS THE UPPER AIR SYSTEM SUPPORTING IT FINALLY MOVES FAR
ENOUGH EAST. THAT WILL END THE LAKE EFFECT RAIN SHOWERS BY MID TO
LATE MORNING MONDAY. WHAT SHOULD FOLLOW IS AT LEAST 24 HOURS OF NEAR
NORMAL TEMPERATURES WITH NO PRECIPITATION. BEYOND THAT IT IS ANY
ONES GUESS WHAT WILL HAPPEN IN TERMS OF SHOWERS AND THUNDERSTORMS AS
IT IS NOT AT ALL CLEAR JUST HOW FAR SOUTH THE NEXT CANADIAN SYSTEM
CAN DIG SOUTHWARD INTO THE GREAT LAKES.
CURRENTLY THERE IS AN OMEGA BLOCK FROM THE BERING SEA EASTWARD
ACROSS ALASKA. THAT ENTIRE SYSTEM MOVES SLOWLY EAST WITH TIME AND BY
SUNDAY IT WOULD SEEM THE CLOSED UPPER LEVEL LOW JUST EAST OF
KAMCHATKA (WEST SIDE OF THE OMEGA BLOCK) TRIES TO PHASE WITH A
SYSTEM NORTH OF ALASKA. THAT IN TURN PHASES TWO JET STREAKS THAT
THEN DIG SOUTHEAST OVER NORTHWEST CANADA. THAT IN TURN HELPS TO
DEEPEN ANOTHER TROUGH OVER EASTERN NORTH AMERICA. OUR ISSUE IS
JUST HOW DEEP DOES THIS EASTERN TROUGH GET? THE GFS VERSION IS
FLATTER THAN THE ECWMF (SYSTEM STAYS NORTH OF THE GREAT LAKES) BUT
GIVEN THE FREQUENCY WITH WHICH WE HAVE SEEN THESE EASTERN NORTH
AMERICA TROUGHS THIS YEAR DIG INTO THE GREAT LAKES... I HAVE TO
FAVOR THE DEEPER ECMWF ON THIS ONE.
AT THE SAME TIME THERE IS A SOUTHERN STREAM SYSTEM MOVING EAST IN
NEAR ZONAL FLOW EARLY NEXT WEEK. IT WOULD SEEM THAT SYSTEM WOULD
PASS JUST SOUTH OF MICHIGAN TUESDAY THANKS TO THE SHORTWAVE RIDGING
OVER MICHIGAN AT THAT TIME (BETWEEN THE DIGGING CANADIAN SYSTEM
AND THE DEPARTING CLOSED UPPER LOW WHICH WOULD BY THEN BE OVER
QUEBEC). THIS WOULD SUGGEST TO ME OUR BEST CHANCE OF MORE
SHOWERS/THUNDERSTORMS WOULD BE IN THE WEDNESDAY/THURSDAY TIME FRAME.
GIVEN THE HIGHLY QUESTIONABLE NATURE OF THE TIMING AND LOCATION OF
THE NEXT SYSTEM I HAVE LOW POPS WED - THU AND FOR NOW WILL CALL THAT
GOOD. IF NOTHING ELSE IT SHOULD BE NEAR TO ABOVE NORMAL IN
TEMPERATURE DURING THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY)
ISSUED AT 1230 PM EDT FRI JUL 26 2013
VFR CONDITIONS SHOULD CONTINUE THROUGH THE AFTERNOON BEFORE
GRADUALLY DETERIORATING TO MVFR TONIGHT AS CIGS GRADUALLY LOWER AND
SHOWERS BECOME MORE WIDESPREAD IN COVERAGE AND INTENSITY.
CONDITIONS WILL MOST LIKELY CONTINUE TO DETERIORATE INTO THE IFR
FLIGHT CATEGORY DURING THE EARLY MORNING HOURS SATURDAY BEFORE
SLOWLY IMPROVING BACK TO MVFR BY MID TO LATE SATURDAY MORNING.
&&
.MARINE...
ISSUED AT 1114 AM EDT FRI JUL 26 2013
OMR CAME IN WITH SOME BIGGER WAVES SO WILL KEEP THE BEACH HAZARDS
GOING. HRRR SHOWS WINDS INCREASING OVER THE NEXT FEW HOURS SO
WAVES SHOULD CONTINUE TO BUILD.
&&
.HYDROLOGY...
ISSUED AT 330 AM EDT FRI JUL 26 2013
A HALF TO PERHAPS AN INCH OF RAIN IS POSSIBLE THROUGH SATURDAY. SOME
OF THE THUNDERSTORMS THAT DEVELOP TODAY THROUGH SATURDAY MAY BE
CAPABLE OF PRODUCING HEAVY RAINFALL AND THUS LOCALIZED FLOODING.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR MIZ037-043-050-
056-064.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR LMZ845>849.
&&
$$
UPDATE...MJS
SYNOPSIS...93
SHORT TERM...93
LONG TERM...WDM
AVIATION...LAURENS
HYDROLOGY...93
MARINE...MJS
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
111 PM CDT Fri Jul 26 2013
.SHORT TERM...(Today through Sunday Afternoon)
Issued at 359 AM CDT FRI JUL 26 2013
Water vapor imagery this morning shows an upper trough deepening
over northern MN. While this feature is expected to slide southeast
the models have continually shown height falls extending further
south. This will eventually manifest itself in cooler air filtering
further south with time. This system will also maintain northwest
flow into Sunday before finally yielding to rising heights over the
Central Plains and a more zonal look to the h5 heights by late in
the weekend.
Today...What had looked to be a promising morning for rain over most
of the CWA is once again proving to be frustrating, just as it has
all week. Convection has broken into two distinct areas. Scattered
convection over northwest MO is related to the southwest extension
of a band of showers and isolated thunderstorms stretching from
northern IL. Models generally agree that this activity will mainly
affect northern MO. The second area of convection is tied to a MCV
now spinning through east central and southeast KS. The northern
portion of the precipitation shield has shown a slow but steady
decrease in intensity and coverage. Prefer weaker and less coverage
shown by the HRRR solution which favors high PoPs only over the
southwestern counties. In between these two areas of precipitation
will keep low chance PoPs going for possible development later this
morning. Also believe isolated convection could form this afternoon
with whatever convergence is generated as a cold front drops south
through the CWA. Clearing from north to south this afternoon will
allow temperatures to rebound into the lower 80s except for the far
southern counties where clouds/rain will keep readings in the upper
70s.
Tonight...Unseasonably cool high pressure will build southward
through the Plains and MO tonight and provide exceptional sleeping
weather.
Saturday through Sunday...Have had to insert some slight to low
chance PoPs over parts of far west central MO and adjacent eastern
KS as the GFS/NAM/ECMWF are now signaling weak perturbations aloft
embedded within the fickle northwest flow aloft will combine with
weak isentropic ascent and banded frontogenesis to wring out some
light showers/isolated storms. The combo of clouds/precipitation and
the abnormally cool surface high will keep temperatures in the 70s
over the weekend. In addition, overnight temperatures both mornings
may threaten record lows.
.LONG TERM...(Sunday Evening through Thursday)
Issued at 359 AM CDT FRI JUL 26 2013
The first half of next week we`ll see very good chances for much
needed rainfall across the area. The best chances look to arrive
Monday evening into Tuesday morning and especially during the
overnight hours. There are several ingredients that really enhance
our chances. The biggest is that there will be a seasonally strong
low level jet nosing right in the Missouri River valley. Ensemble
data suggest this is about 4 standard deviations stronger than
normal for this time of year. We`ll also continue to see
precipitable water values around 2 inches, which is slightly above
normal for this time of year. Models are also in good agreement with
an area of strong isentropic lift and moisture stability flux nosing
into the area Monday night. All this points to very high POPs for
this stretch of time with the potential for a good amount of
precipitation. I actually feel there is a better chance with this
setup than with the northwest flow pattern from last weekend because
of the strength of the LLJ nosing into the area. This is something
that was lacking last weekend. So fingers crossed, a few inches of
rain would go a long way, at this point, to easing the precipitation
deficits we`ve racked up in June and July so far.
With all the likely cloud cover and possible precipitation,
temperatures on Monday should be well below normal across the entire
area. Highs have a strong potential of staying in the 70s. By
Tuesday afternoon, the bulk of the precipitation should be moving
into eastern Missouri with skies clearing from west to east. So we
should be able to climb back to more normal temperatures across
eastern Kansas and western Missouri by the afternoon. It will be
tougher to get to normal in our east as cloud cover and precip may
linger longer into the day.
The next decent chance for rain may come Friday as we once again are
in a northwest flow pattern with weak waves migrating through the
flow. After last weekend though, I`m a little gun shy about going
very high on POPs. The model consensus was to keep things in the
chance category and that sounds reasonable at this point.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 111 PM CDT FRI JUL 26 2013
Scattered showers will prevail in areas to the south of Kansas City
for the remainder of the day, though these storms will stay well
clear of the terminals. Scattered to broken cloud cover will continue
to slowly clear from the terminals as a cold front settles through
the region. Light winds expected overnight will return from the north
Saturday morning. Otherwise, have included a hedge towards more
storms in the vicinity of Kansas City for Saturday morning as more
nocturnal activity is expected to slide through eastern Kansas early
in the morning.
&&
.CLIMATE...
Issued at 359 AM CDT FRI JUL 26 2013
Abnormally cool high pressure will approach record low temperatures
Saturday and Sunday mornings.
July 27 July 28
Min/Year Min/Year
Kansas City 55/1994 52/1994
St. Joseph 47/1971 53/2005
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...CDB
AVIATION...Cutter
CLIMATE...MJ
AREA FORECAST DISCUSSION
NWS BILLINGS MT
250 PM MDT FRI JUL 26 2013
.SHORT TERM...VALID FOR SAT AND SUN...
THE BREAKDOWN OF THE NORTHERN ROCKIES UPPER-LEVEL RIDGE WILL YIELD
A RISK OF DRY THUNDERSTORMS IN SOUTH CENTRAL MT SATURDAY AFTERNOON
AND EVENING...BEFORE LOWERING HEIGHTS YIELD MORE WIDESPREAD SHOWER
AND STORM ACTIVITY OF A WET VARIETY OVER THE WHOLE AREA ON SUNDAY.
TONIGHT...WE LEFT SOME LOW POPS IN PLAY OVER SOUTH CENTRAL MT WITH
WEAK UPSLOPE FLOW. RECENT HRRR RUNS SUPPORT ISOLATED STORMS ACROSS
THAT AREA. OTHERWISE...WE WILL NEED TO KEEP AN EYE ON ANY SMALLER-
SCALE PERTURBATIONS IN NORTHWEST FLOW OVER SOUTHEASTERN MT IN CASE
THEY ARE ABLE TO GENERATE SOME PRECIPITATION...BUT FOR NOW WE LEFT
A DRY FORECAST IN PLACE THERE.
SAT...IT APPEARS THAT A COUPLE OF WEAK SHORT WAVES OBSERVED IN THE
FRIDAY AFTERNOON MOISTURE CHANNEL IMAGERY FROM NORTHERN CA INTO OR
WILL MOVE INTO SOUTH CENTRAL MT BY LATE IN THE DAY. MODEL GUIDANCE
HAS BEEN CONSISTENT IN ADVERTISING THIS EVOLUTION AS HEIGHTS ALOFT
START TO FALL BY LATE DAY...AND THAT SHOULD FOSTER SCATTERED STORM
ACTIVITY. FORECAST SOUNDINGS IN SOUTH CENTRAL MT STILL SHOW A WEAK
CAPE ENVIRONMENT...BUT STEEP LOW- AND MID-LEVEL LAPSE RATES WITH A
PLUME OF MID- AND HIGH-LEVEL MOISTURE WHICH IS FAVORABLE FOR HIGH-
BASED THUNDERSTORMS. COVERAGE WOULD ORDINARILY BE IN QUESTION WITH
MLCAPE LESS THAN 500 J/KG...AND IN SOME WAYS IT STILL IS...BUT THE
SYNOPTIC-SCALE ENVIRONMENT IS FAVORABLE FOR CONVECTION AND THAT IS
HELPING BUILD OUR CONFIDENCE IN STORM DEVELOPMENT. THE 09 UTC SREF
CALIBRATED DRY THUNDERSTORM PROBABILITIES HAVE RISEN SINCE THE RUN
FROM THAT TIME YESTERDAY /WHEN THEY WERE ALREADY NOTABLE/...AND SO
THERE IS STATISTICAL SUPPORT FOR THE THREAT OF DRY LIGHTNING WHICH
FORECAST SOUNDINGS IMPLY. PRECIPITABLE WATER VALUES WILL BE AROUND
0.75 INCHES...AND BOUNDARY LAYER HUMIDITIES WILL BE AT OR BELOW 20
PERCENT EVEN THOUGH HIGHS MAY ONLY BE AROUND 90 F. FIRE MANAGEMENT
OFFICIALS CONFIRM THAT FUELS OVER THE GALLATIN NATIONAL FOREST ARE
RECEPTIVE OF LIGHTNING AND SO NEW FIRE STARTS ARE A CONCERN. BASED
ON THAT RISK...WE ISSUED A FIRE WEATHER WATCH ACROSS THAT AREA AND
THE SWEET GRASS AND WHEATLAND COUNTY FIRE WEATHER ZONE FROM 18 UTC
THROUGH 06 UTC. PER DISCUSSION WITH FIRE MANAGEMENT OFFICIALS...WE
DID NOT CARRY THE HEADLINE EAST OF THAT AREA SINCE FUELS AREN/T AS
DRY. NOTE THAT THE INVERTED-V SOUNDING PROFILES ALSO SUPPORT GUSTY
AND ERRATIC OUTFLOW WIND GUSTS OF 50 MPH...AND A SEVERE-LEVEL WIND
EVENT IS NOT OUT OF THE QUESTION. ISOLATED CONVECTION MAY MAKE IT
INTO SOUTHEASTERN MT BY SAT NIGHT.
SUN...SOUTHWEST FLOW ALOFT SHOULD YIELD MORE WIDESPREAD CONVECTION
AS PRECIPITABLE WATER VALUES CLIMB TO AN INCH OR BETTER. THERE HAS
BEEN SOME CONSISTENCY IN MODEL SOLUTIONS IN SHOWING A MODEST FRONT
AND ASSOCIATED WIND SHIFT OVER SOUTHEASTERN MT...WHICH COULD FOCUS
ENOUGH STORMS TO GARNER LIKELY POPS WITH LATER FORECASTS. SUN WILL
ALSO BE COOLER BEHIND THAT FRONT. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
MODELS REMAIN IN GOOD AGREEMENT THROUGH THE EXTENDED FORECAST IN
ADVERTISING A CHANGE TO UNSETTLED WEATHER AND NEAR SEASONAL
TEMPERATURES. UPPER LEVEL TROUGH OF LOW PRESSURE ALONG THE WEST
COAST WILL KEEP A SOUTHWEST TO WEST FLOW ACROSS OUR FORECAST AREA.
THIS WILL ENABLE A SERIES OF SHORT WAVES TO MOVE ACROSS SOUTHERN
MONTANA. THESE UPPER LEVEL SYSTEMS WILL BE ACCOMPANIED BY PACIFIC
MOISTURE. ADDITIONAL LOW LEVEL MOISTURE WILL BE ADVECTING INTO THE
REGION AS LOW PRESSURE OVER THE WEST COAST WILL MAINTAIN A WEAK
UPSLOPE FLOW ACROSS OUR REGION. HAVE CONTINUED SCATTERED POPS
THROUGH THE EXTENDED FORECAST WITH MODELS IN GOOD AGREEMENT. LOWER
HEIGHTS ACROSS THE AREA WILL RESULT IN TEMPERATURES AT OR SLIGHTLY
BELOW SEASONAL VALUES. HAVE MADE ONLY MINOR CHANGES TO
TEMPERATURE FORECAST. RICHMOND
&&
.AVIATION...
A FEW ISOLATED THUNDERSTORMS WILL BE POSSIBLE OVER THE HIGHER
TERRAIN AS WELL AS ADJACENT SLOPES LATE THIS AFTERNOON.
THUNDERSTORMS WILL DIMINISHING IN COVERAGE DURING THE EVENING AND
WILL BE CONFINED TO THE HIGHER TERRAIN. STORMS COULD CONTAIN WIND
GUSTS TO 40KTS. OTHERWISE...VFR CONDITIONS WILL PREVAIL AT ALL
FLIGHT TERMINALS OVERNIGHT. RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 059/090 063/082 061/080 058/085 059/086 061/084 060/084
12/T 32/T 43/T 32/T 33/T 33/T 33/T
LVM 051/093 054/083 052/079 049/085 051/085 052/081 051/080
23/T 32/T 33/T 23/T 33/T 32/T 33/T
HDN 057/091 060/085 059/082 058/086 059/086 060/085 060/085
12/T 33/T 44/T 32/T 23/T 33/T 33/T
MLS 056/086 062/086 062/082 060/085 060/086 062/085 062/085
11/U 24/T 54/T 33/T 33/T 33/T 33/T
4BQ 051/086 058/086 057/082 058/083 058/085 058/085 059/084
11/U 24/T 54/T 33/T 33/T 34/T 33/T
BHK 048/077 053/080 057/078 056/079 056/080 058/080 057/080
11/N 25/T 54/T 33/T 22/T 33/T 33/T
SHR 054/089 056/083 055/081 055/086 055/085 056/083 055/083
23/T 34/T 44/T 32/T 22/T 33/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...FIRE WEATHER WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
SATURDAY EVENING FOR ZONES 28-40-41-63>68.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...ISSUED BY KOAX
NWS HASTINGS NE
1247 PM CDT FRI JUL 26 2013
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z SATURDAY AFTERNOON)
VFR CONDITIONS EXPECTED THRU THE FCST PD. HOWEVER...HAVE DECIDED TO
INCLUDE A PROB30 GROUP SAT MORNING FOR POSSIBLE PCPN ASSOCIATED WITH
A WEAK MID LYR DISTURBANCE MOVING THRU. AT THIS POINT IT APPEARS
ANY PCPN ACTIVITY THAT DOES FOR WILL BE HIGH BASED...THUS DID NOT
TAKE CIGS BELOW MVFR.
DEE
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT FRI JUL 26 2013
SOME PATCHY FOG HAS DEVELOPED ACROSS THE REGION THIS MORNING IN
RESPONSE TO LIGHT WINDS...CLEARING SKIES...ELEVATED DEW POINTS AND A
STRONG INVERSION. EXPECT THIS FOG TO BECOME MORE WIDESPREAD JUST
BEFORE SUNRISE...ESPECIALLY ACROSS SOUTHWESTERN PORTIONS OF THE
FORECAST AREA THAT RECEIVED SOME MODEST RAINFALL AMOUNTS
THURSDAY/THURSDAY NIGHT AND WHERE WINDS REMAIN LIGHT. LATEST
HRRR/SREF PROBS INDICATE THIS FOG SHOULD BE QUICK TO CLEAR JUST
AFTER SUNRISE...WITH MOSTLY SUNNY SKIES EXPECTED ACROSS ALL AREAS
BY 15Z AT THE LATEST. IN FACT...LATEST HRRR IS NOW QUESTIONING ANY
DENSE FOG DEVELOPMENT IN GENERAL.....BUT WITH SEVERAL SITES
FLIRTING WITH 1-5 SM OF VISIBILITY THE PAST COUPLE OF
HOURS...THINK THAT FURTHER DETERIORATION IS STILL POSSIBLE THROUGH
THE REMAINDER OF THE OVERNIGHT/EARLY MORNING HOURS.
IN WAKE OF THE WEAK COLD FRONT THAT MOVED ACROSS THE REGION
OVERNIGHT...EXPECT TEMPERATURES THIS AFTERNOON TO REMAIN ON THE COOL
SIDE OF CLIMATOLOGY...WITH AFTERNOON HIGHS GENERALLY STRUGGLING TO
REACH 80 NORTH OF INTERSTATE 80...WITH LOWER 80S EXPECTED ACROSS THE
REMAINDER OF SOUTH CENTRAL NEBRASKA AS WELL AS NORTH CENTRAL KANSAS.
IN ADDITION TO THE COOL TEMPERATES...CLEARING SKIES WILL ALLOW FOR
GOOD MIXING ACROSS THE REGION THIS AFTERNOON...WITH OCCASIONALLY
GUSTY NORTHERLY WINDS EXPECTED ACROSS THE LOCAL AREA...RESULTING IN
A MOSTLY SUNNY...YET BREEZY AFTERNOON.
LATEST GUIDANCE IS IN GOOD AGREEMENT MAINTAINING NORTHWESTERLY FLOW
ACROSS THE CENTRAL PLAINS THIS AFTERNOON AND EVENING...AS THE LOCAL
AREA REMAINS IN BETWEEN A LARGE AREA OF LOW PRESSURE ACROSS THE GREAT
LAKES REGION AND AN AREA OF HIGH PRESSURE ACROSS THE DESERT
SOUTHWEST. EXPECT THE NEXT UPPER LEVEL DISTURBANCE EMBEDDED IN THIS
NORTHWESTERLY FLOW TO WORK ITS WAY AROUND THE UPPER LEVEL LOW TO OUR
NORTHEAST LATE TONIGHT...WITH A CHANCE OF SHOWERS AND THUNDERSTORMS
RETURNING TO THE LOCAL AREA AFTER 06Z. WITH GOOD MODEL CONSENSUS
HANDLING THIS DISTURBANCE...INCREASED THE CHANCE FOR PRECIPITATION
POST 06Z AS THE AFOREMENTIONED UPPER LEVEL DISTURBANCE APPROACHES
THE LOCAL AREA.
WHILE THE OVERALL AIRMASS IS EXPECTED TO REMAIN COOL ACROSS THE
REGION OVERNIGHT...CLOUDS ASSOCIATED WITH THE APPROACHING
DISTURBANCE MAY HAVE AN IMPACT ON OVERNIGHT LOWS...BUT CONTINUE TO
THINK LOW TEMPERATURES SATURDAY MORNING WILL BOTTOM OUT IN THE LOWER
TO MIDDLE 50S AT MOST LOCATIONS THANKS TO THE EARLY CLEARING AND
COOL AIRMASS IN PLACE...WHICH WILL BE THE COOLEST MORNING
TEMPERATURE READINGS WE HAVE SEEN SINCE THE BEGINNING OF THE MONTH
WHEN GRAND ISLAND...HASTINGS AND KEARNEY ALL REPORTED LOWS OF 52 ON
THE 1ST OF JULY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 AM CDT FRI JUL 26 2013
ALOFT: NW FLOW WILL CONTINUE SAT-SUN ANCHORED BY AN ERN USA TROF AND
A SLOW-MOVING LOW /-3 STANDARD DEVIATIONS FOR LATE JULY/ OVER THE
GREAT LAKES. THE CLOSED LOW /CURRENTLY SEEN IN WV IMAGERY OVER
BRITISH COLUMBIA/ WILL MOVE INLAND SAT-SUN...SPREADING HGT FALLS
OVER THE WRN USA AND TEMPORARILY SUPPRESSING THE SUBTROPICAL HIGH.
THIS WILL CHANGE THE FLOW OVER THE CNTRL PLAINS TO ZONAL MON-TUE BUT
WITH RISING HGTS AS THE NEXT TROF APPROACHES THE W COAST AND ALLOWS
THE SUBTROPICAL HIGH TO EXPAND N OVER THE SRN USA. THIS WILL THEN
MODIFY THE FLOW TO WNW WED-THU.
THIS PATTERN WILL MAINTAIN BELOW NORMAL TEMPS INTO EARLY NEXT WEEK
WITH A GRADUAL UPWARD TREND...RETURNING TO NEAR NORMAL /UPR 80S TO
LOW 90S/.
SFC: THE COOL FRONT MOVING THRU TODAY WILL BECOME PARALLEL TO THE
UPR FLOW /NW-SE/ FROM THE PANHANDLE THRU CNTRL KS. THIS FRONT WILL
REMAIN STATIONARY THRU MON AND THEN DISSIPATE. COOL HIGH PRES WILL
BE OVER THE PLAINS SAT AND DEPART INTO THE ERN USA SUN. THIS HIGH
WILL FILTER COOLER/DRIER AIR INTO THE REGION. ANOTHER COOL FRONT
WILL DROP INTO THE NRN PLAINS TUE. IT REMAINS UNCERTAIN WHEN THIS
FRONT WILL MOVE INTO THE FCST AREA /THU OR FRI?/ BUT IT WILL
EVENTUALLY BECOME STATIONARY.
WITH LWR HGTS IN PLACE OVER THE LAST FEW DAYS...WE SEEM TO HAVE
ENTERED A MORE ACTIVE PATTERN WITH MUCH BETTER POTENTIAL FOR RAIN
THAN THE 7 WEEK PERIOD FROM JUN 1ST THRU JUL 20TH. THIS MORE
FAVORABLE PATTERN APPEARS TO STICK AROUND THE NEXT FEW DAYS.
HAZARDS: MULTIPLE CHANCES FOR TSTMS. WE ARE NOT SEEING ANY SIGNALS
FOR WIDESPREAD SVR TSTMS. HOWEVER...ISOLATED SVR WILL BE
OCCASIONALLY POSSIBLE. THE MAIN TIME PERIOD TO WATCH WILL BE SUN NGT.
THE DAILY DETAILS...
SAT: FGEN-DRIVEN BANDS OF RAIN WILL PROBABLY BE ON-GOING AT DAWN AND
CONTINUE AT LEAST THRU THE MRNG BEFORE ENDING/EXITING TO THE SE.
THIS LOWERS CONFIDENCE IN HIGH TEMPS IF MODELS ARE OFF IN THEIR
LOCATION OF THE CLOUDS/RAIN.
THE ONLY APPRECIABLE INSTABILITY /SEEN IN MUCAPE/ DOESNT APPEAR TO
BE GREAT ENOUGH TO WARRANT A MENTION OF THUNDER. SO IT HAS BEEN
WITHDRAWN FROM THE FCST. MID-LVL LAPSE RATES ARE FCST TO BE MOIST
ADIABATIC.
QPF: MODELS ARE WIDELY DISPERSIVE WITH THEIR AMTS. IT WILL BE
INTERESTING TO SEE HOW THIS PANS OUT. MOST MODELS SUGGESTS .1 TO .33
FOR THIS EVENT...BUT THE 00Z NAM AND EC SUGGEST A SWATH OF .5" IS
POSSIBLE WITH MAX AMTS OF 0.75" OR MORE. THIS ISNT IN THE BAG YET
AND IT WONT BE FOR EVERYWHERE. THE FACT THE THE EC IS ON BOARD LENDS
CREDENCE TO THE NAM. THIS IS JUST ONE RUN FOR EACH. SO LETS SEE HOW
LATER CYCLES EVOLVE.
H8 TEMPS 2 STANDARD DEVIATIONS BELOW NORMAL AND WITH POTENTIAL FOR
CLOUD COVER MUCH OF THE DAY...THERE IS POTENTIAL FOR RECORD COOLEST
HIGH TEMPS ON RECORD /FOR JUL 27TH/ TO BE THREATENED. THE 64 IN 1981
AT GRI SHOULD BE SAFE...BUT THE CURRENT FCST OF 71 WOULD COME IN AS
THE 2ND COOLEST JUL 27TH ON RECORD.
IF THE "WORST" CASE SCENARIO HAPPENS /CLOUDY ALL DAY WITH STEADY
RAIN THRU EARLY AFTN/ THEN WE MAY BE TOO WARM BY 3-5F IN SOME
LOCATIONS AND NOT HIGH ENOUGH ON CLOUD COVER. ALL MODEL 2M TEMP
GUIDANCE EXCEPT GFS SUGGESTS SOME WONT GET OUT OF THE 60S. IT ALL
DEPENDS WHERE THE RAIN SETS UP. AREAS THAT CAN MAINTAIN THE LEAST
AMT OF CLOUDS COULD APPROACH 80F.
SAT NGT: A FEW TSTMS SHOULD ERUPT ALONG AND ON THE IMMEDIATE COOL
SIDE OF THE FRONT...FROM CNTRL KS NW INTO THE PANHANDLE. A 35 KT LLJ
IS FCST TO DEVELOP WITH ITS NOSE OVER NWRN KS. WITH THE ASSOCIATED
ASCENT OVER THE FRONT...THE REMNANTS OF THESE STORMS COULD DRIFT
INTO AREAS S AND W OF THE TRI-CITIES. AT BEST MUCAPE AROUND 500 J/KG
IS FCST AND THIS IS JUST OVER N-CNTRL KS. SO THUNDER HAS BEEN
REMOVED FROM THE FCST OVER S-CNTRL NEB.
SUN: PROBABLY M/CLOUDY WITH SOME PATCHY LGT RAIN OR SPRINKLES. WE DO
HAVE A CHANCE OF SOME STRATIFORM RAIN IN THE FCST...BUT VERTICAL
MOTION IS WEAK. SO CURRENT EXPECTATION IS FOR LOW QPF. MODELS ARE
MAINTAINING A LARGE BATCH OF HIGH MEAN RH IN THE PERSISTENT PRESENCE
OF THE ENTRANCE REGION OF AN 80 KT ULJ. THERE IS ALSO A HINT OF A
SUBTLE VORT MAX /CURRENTLY OVER AZ AND SRN CA/ WHICH ROUNDS THE
SUBTROPICAL HIGH AND ARRIVES HERE SUN-SUN NGT.
STRENGTHENING RETURN FLOW WILL BEGIN TRANSPORTING RICH MSTR BACK
INTO THE REGION...WITH PW CLIMBING BACK ABOVE 1.5 TO 1.75" AND H8
DWPTS TO +15C.
SUN WILL BE ANOTHER DAY OF MUCH BELOW NORMAL DAYTIME TEMPS.
SUN NGT: HIGH RH REMAINS WITH SUBTLE SHRTWV TROF MOVING THRU. MODELS
ARE EMPHATIC IN MCS DEVELOPMENT...BUT CONFIDENCE IS LOW IN EXACTLY
WHERE. MOST MODELS SUGGESTS KS. A MUCH BROADER/STRONGER LLJ IS FCST
/CLOSE TO 50 KTS/. PW IS FCST TO INCREASE TO 1.90" OVER CNTRL-ERN KS.
THIS COULD END UP AN OPPORTUNITY FOR DRENCHING RAINS FOR PARTS OF
THE FCST AREA.
MON: STILL MUCH BELOW NORMAL TEMPS. A LARGE TSTM COMPLEX WILL BE
EXITING THE REGION AND EXPECT GRADUALLY DECREASING CLOUDS.
TUE: LOOKING DRY AND NICE FOR NOW. TEMPS TAKE A BIG JUMP BACK CLOSE
TO NORMAL.
WED: CHANCE OF AFTN-EVNG TSTMS? COVERAGE IS PROBABLY LOW. TEMPS NEAR
NORMAL.
THU: MAYBE BETTER COVERAGE OF AFTN-EVNG TSTMS? TEMPS NEAR NORMAL.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SAR
LONG TERM...HALBLAUB
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
412 PM EDT FRI JUL 26 2013
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD INTO THE NORTH COUNTRY TONIGHT AND
SATURDAY...WITH DRY CONDITIONS AND NEAR NORMAL TEMPERATURES
EXPECTED. THE NEXT SYSTEM WILL IMPACT OUR REGION WITH SEVERAL
PERIODS OF SHOWERS FROM SATURDAY NIGHT THROUGH EARLY MONDAY. THE
BEST CHANCE FOR WIDESPREAD RAINFALL WILL BE SUNDAY AFTERNOON INTO
EARLY MONDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 410 PM EDT FRIDAY...FCST FOCUS WL BE POPS ACRS EASTERN VT...FOLLOWED
BY CLRING AND POTENTIAL FOG DEVELOPMENT. POTENT S/W ENERGY AND
ASSOCIATED CLOSED 5H/7H CIRCULATION CONTS TO MOVE INTO EASTERN NEW
ENGLAND...WHILE BACKSIDE MOISTURE LEAF IS WEAKENING OVER
CENTRAL/EASTERN VT. BOTH RAP13 AND 3KM HRRR MODELS CONT TO SHOW
WEAK COMPOSITE REFLECTIVITY RETURNS ACRS EASTERN VT THRU 03Z THIS
EVENING...THEREFORE WL MENTION CHC POPS...SIMILAR TO PREVIOUS
FCST. OTHERWISE...LARGE SCALE SUBSIDENCE BEHIND POTENT S/W ENERGY
SHOULD RESULT IN DECREASE CLOUDS...WHICH IS SUPPORTED BY LATEST
SATL PIC TRENDS ACRS CENTRAL/NORTHERN NY. THIS WINDOW OF CLRING IS
SMALL...BEFORE CLOUDS AHEAD OF OUR NEXT SYSTEM APPROACHING OUR FA.
TEMPS WL BE HIGHLY DEPEND UPON CLOUDS WITH COOLEST TEMPS ACRS THE
DACKS AND WARMEST CPV/CT RIVER VALLEY...MAINLY IN THE 40S TO M50S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 410 PM EDT FRIDAY...AN ACTIVE WEATHER PATTERN IS EXPECTED WITH
SEVERAL ROUNDS OF SHOWERS WITH EMBEDDED STORMS
LIKELY...ESPECIALLY SUNDAY AFTN INTO EARLY MONDAY. STILL SOME
UNCERTAINTY ON TIMING OF PRECIP...WITH NAM MUCH SLOWER THAN
GFS/ECMWF. WL USE A BLEND BTWN THE 12Z GUIDANCE AND PREVIOUS
FCSTERS...WHICH SUPPORTS CHCS POPS SAT NIGHT WITH LIKELY/CAT
POPS...ESPECIALLY SUNDAY AFTN/EVENING.
WATER VAPOR SHOWS DEEP CLOSED 5H/7H CIRCULATION ACRS THE WESTERN
GREAT LAKES WITH A FULL LATITUDE TROF DEVELOPING OVER THE MS VALLEY.
THIS DEEP CYCLONIC CIRCULATION WL EJECT SEVERAL PIECES OF ENERGY
ALONG WITH RIBBONS OF ENHANCED MOISTURE ACRS OUR CWA FROM SAT NIGHT
THRU SUNDAY NIGHT. THE FIRST WAVE ARRIVES ACRS OUR WESTERN CWA
AROUND 06Z SUNDAY...BEFORE WEAKENING OVER THE CPV BY 15Z
SUNDAY...NEXT S/W ENERGY...DEEPER 850 TO 500MB RH AND SOME WEAK
INSTABILITY ARRIVES BTWN 21Z-03Z SUNDAY AFTN/EVENING...WITH MORE
SHOWERS. FEEL A SLIGHTLY SLOWER SOLUTION FOR 2ND ROUND OF RAIN WITH
EMBEDDED STORMS LOOKS REASONABLE GIVEN FRNT IS PARALLELING ULVL FLW
AND TROF/CLOSED SYSTEM IS STILL LOCATED OVER THE CENTRAL GREAT LAKES
ON SUNDAY AFTN.
IN ADDITION...POTENTIAL FOR LOCALIZED HEAVY RAINFALL
AND TRAINING OF SHOWERS WITH EMBEDDED CONVECTION WL BE
POSSIBLE...GIVEN POSITION OF 85H JET OF 30 KNOTS ALONG BOUNDARY AND
FA UNDER RRQ OF 100 KNT AT 25H. FURTHERMORE...DEEP SOUTHERLY FLW WL
HELP TO ADVECT PW VALUES BTWN 1.75 AND 2.0" ALONG AND AHEAD OF SFC
BOUNDARY ON SUNDAY...WITH INCREASED HUMIDITY VALUES LIKELY. SOUNDING
PROFILES SHOW A TALL SKINNY CAPE WITH VALUES BTWN 300 AND 600 J/KG
AND WARM CLOUD DEPTHS AROUND 12KFT...ALONG WITH VECTOR ANALYSIS
SUGGESTING TRAINING OF CONVECTION...ESPECIALLY SUNDAY AFTN/EVENING.
THINKING RAINFALL QPF WL RANGE BTWN 0.50" TO 2.0" BY MONDAY
MORNING...WITH GREATEST ACTIVE BTWN 21Z AND 03Z SUNDAY AFTN/EVENING.
WL KEEP SAT DRY ATTM...BUT GIVEN SMALL WINDOW OF CLR SKIES ON LATEST
SATL PICS...EXPECT MID/UPPER LVL CLOUDS TO ADVANCE FROM WEST TO EAST
ACRS OUR REGION.
LOCAL 2KM AND 4KM COMPOSITE REFLECTIVITY PROGS FOR SUNDAY AFTN
SUGGEST THE POTENTIAL FOR A FINE LINE OF CONVECTION WITH SOME GUSTY
WINDS POSSIBLE. SOUNDINGS INDICATE A HIGH SHEARED...BUT LOW CAPE
ENVIRONMENT...SUPPORTING LOW TOP CONVECTION WITH GUSTY WINDS
POSSIBLE.
WL MENTION CHC/LOW LIKELY POPS SAT NIGHT...WITH HIGHEST POPS WESTERN
CWA...WITH SCHC EASTERN VT. SUNDAY WL BE TRICKY WITH RAIN LIKELY IN
THE MORNING FOR THE DACKS/SLV...WITH CHC POPS VT...THEN MORE RAIN
LIKELY TO CAT AFT 21Z. I WOULD EXPECT SOME DRY PERIODS ON SUNDAY.
PROGGED 85H TEMPS SUPPORT HIGHS M70S MTNS (DACKS)TO L/M80S WARMER
VALLEYS ON SAT. CLOUDS/PRECIP WL KEEP TEMPS MAINLY IN THE 70S TO
L80S ON SUNDAY...EVEN WITH SLIGHTLY WARMER 85H TEMPS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 410 PM EDT FRIDAY...UPPER TROUGH AXIS WILL EXIST OVER SOUTHEAST
ONTARIO AND THE OHIO VALLEY AT THE START OF THE PERIOD...BUT NOT
MOVE EAST OF THE AREA UNTIL TUESDAY NIGHT. PRONOUNCED DRY SLOT AT
THE START OF MONDAY WILL KEEP ANY PRECIPITATION OVER EASTERN
VERMONT EARLY...THEN SOME DESTABILIZATION LATER IN THE DAY MAY
ENHANCE A FEW SHOWERS OVER NORTHERN NEW YORK. STEEPER LAPSE RATES
DEVELOP ON TUESDAY WITH UPPER TROUGH AXIS MOVING ACROSS THE AREA
AND STILL LOOKING FOR AFTERNOON SHOWERS ACROSS MOST OF THE NORTH
COUNTRY. WESTERLY FLOW ALOFT FOR WEDNESDAY SUGGESTS THAT WILL BE
THE DRIEST PERIOD OF THE EXTENDED BEFORE FLOW ALOFT BACKS ON
THURSDAY AHEAD OF A SHORTWAVE TROUGH. THUS GOING FORECAST OF A
CHANCE OF SHOWERS STILL LOOKS GOOD WITH SLOWLY IMPROVING
CONDITIONS ON FRIDAY. HIGH TEMPERATURES THROUGH THE PERIOD WILL BE
AT OR SLIGHTLY BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
THROUGH 18Z SATURDAY...VFR CONDITIONS EXPECTED THROUGH MOST OF THE
PERIOD. THE ONLY EXCEPTIONS TO THIS WILL BE AT KSLK WHERE IFR
CONDITIONS ARE EXPECTED BETWEEN 06Z AND 12Z AND WHERE BRIEF MVFR
VISIBILITIES ARE POSSIBLE AT KMPV DURING THIS SMALL WINDOW OF TIME
AS WELL. OTHERWISE...ANY CLOUD COVER WILL GENERALLY BE ABOVE 12000
FEET. LIGHT NORTHERLY WINDS THIS AFTERNOON WILL BECOME CALM
OVERNIGHT THEN BECOME MORE SOUTH AND SOUTHWEST SATURDAY...BUT AT
SPEEDS UNDER 10 KNOTS.
OUTLOOK 18Z SATURDAY THROUGH TUESDAY...
18Z SATURDAY THROUGH 06Z SUNDAY...VFR UNDER HIGH PRESSURE.
06Z SUNDAY THROUGH 12Z MONDAY...MAINLY VFR WITH PERIODS OF MVFR/IFR
LIKELY IN SHOWERS AND POSSIBLE TSRA WITH COLD FRONT PASSAGE.
12Z MONDAY THROUGH TUESDAY...MAINLY VFR WITH THE CHANCE FOR MVFR
RAIN SHOWERS EACH AFTERNOON AS UPPER LEVEL LOW PRESSURE SHIFTS
EAST THROUGH THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LAHIFF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
253 PM CDT FRI JUL 26 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 253 PM CDT FRI JUL 26 2013
NO PRECIPITATION FOR THE SHORT TERM PERIOD...WITH THE MAIN
CHALLENGE BEING RECORD COLD TEMPERATURES FOR SATURDAY
MORNING...MAINLY FOR BISMARCK AND JAMESTOWN.
LATEST VISIBLE SATELLITE IMAGERY SHOWS SCT/BKN CUMULUS FIELD
COVERING ALL OF NORTH DAKOTA. CYCLONIC FLOW WITH AN UPSTREAM
SHORTWAVE TROUGH OVER SOUTHERN SASKATCHEWAN WILL MAINTAIN THE
CUMULUS FIELD THROUGH THE EVENING...AND AFTER SUNSET WILL SEE A
GRADUAL REDUCTION IN CLOUDS WITH CLEAR SKIES COMMENCING LATER
TONIGHT. THE SHORTWAVE IS EXPECTED TO MAKE IT TO AROUND STANLEY BY
00Z SATURDAY...THEN INTO THE JAMES RIVER VALLEY BY 06Z SATURDAY.
THE GFS AND TO SOME EXTENT THE RAP AND HRRR TRY TO DEVELOP A
COUPLE SHOWERS IN THE SOUTHWEST AND ALSO IN THE NORTHEAST/TURTLE
MOUNTAINS THIS AFTERNOON...BUT HAVE OPTED TO KEEP IT DRY WITH
REGIONAL RADAR AND SURFACE OBSERVATIONS CONTINUING TO SHOW A VOID
IN ANY PRECIPITATION DEVELOPMENT UP TO THIS POINT. A 1030MB
SURFACE HIGH PRESSURE OVER SOUTHEASTERN SASKATCHEWAN WILL ALSO
SHIFT SOUTHEAST INTO EAST CENTRAL NORTH DAKOTA...AND INTO THE
LOWER JAMES RIVER VALLEY BY 12Z SATURDAY. UPSTREAM LOW
TEMPERATURES IN SOUTH CENTRAL CANADA FRIDAY MORNING RANGED FROM
38F TO 42F...WHICH IS IN THE BALLPARK OF WHAT THE MET/MAV GUIDANCE
IS FOR CENTRAL NORTH DAKOTA. THE OLD RULE OF THUMB USING THE
MINIMUM DEWPOINT DURING THE MAX TEMPERATURE FOR OBTAINING AN
APPROXIMATE LOW TEMPERATURE ALSO SUPPORTS LOWS BETWEEN 39F AND
44F. CONFIDENCE IS HIGH FOR RECORD LOWS IN BISMARCK AND
JAMESTOWN...WITH MINOT...WILLISTON...AND DICKINSON COMING JUST SHY
OF ESTABLISHING NEW RECORD LOWS.
RECORD LOW TEMPERATURES FOR SATURDAY JULY 27 ARE AS FOLLOWS...
CITY RECORD LOW/DATE FORECAST LOW TEMP
BISMARCK 43F/1994 41F
JAMESTOWN 44F/1904 41F
MINOT 40F/1925 42F
WILLISTON 40F/1908 43F
DICKINSON 40F/1971 43F
CONSIDERING THE LOCATION OF THE SURFACE HIGH...EAST CENTRAL NORTH
DAKOTA AND INTO THE SOUTHERN JAMES RIVER VALLEY...THIS IS THE
OPTIMAL LOCATION FOR OBTAINING THE COLDEST TEMPERATURES ACROSS
SOUTH CENTRAL NORTH DAKOTA...BISMARCK AND JAMESTOWN. UPSTREAM
OBSERVATIONS IN SOUTH CENTRAL CANADA ALSO HAD SOME PATCHY FOG FRIDAY
MORNING AND HAVE ADDED THAT TO THE FORECAST...MAINLY ALONG AND
JUST EAST OF HIGHWAY 83.
FOR SATURDAY...SUNNY WEST...AND MOSTLY SUNNY SKIES CENTRAL.
EXPECT MID TO LATE MORNING CUMULUS AGAIN DEVELOPING OVER CENTRAL
NORTH DAKOTA WITH WEAK CYCLONIC FLOW...BUT SOUNDINGS SHOW DRY
AIR/SUBSIDENCE ALOFT WILL BECOME MUCH STRONGER..AND THIS WILL
INHIBIT ANY FURTHER BUILD UPS FOR THE AFTERNOON. THE RESULT WILL
BE A SCATTERED FAIR WEATHER CUMULUS FIELD EARLY ON...THEN
DISSIPATING THROUGH THE AFTERNOON. AFTERNOON HIGHS AROUND 70F
CENTRAL TO THE MID 70S WEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 253 PM CDT FRI JUL 26 2013
WE TRANSITION FROM A COOL AND DRY PERIOD BACK TO A WARMER AND
ACTIVE PERIOD FOR THE BEGINNING OF THE LONG TERM PERIOD.
AFTERWARDS...A RETURN TO A RELATIVELY QUIET PERIOD IS EXPECTED
THROUGH THE MIDDLE PORTIONS OF THE WORK WEEK UNTIL LATER NEXT WEEK
WHEN WE MAY SEE INCREASING CHANCES FOR MORE WIDESPREAD
PRECIPITATION.
RETURN FLOW INCREASES OVER WESTERN NORTH DAKOTA SATURDAY NIGHT AS
SURFACE HIGH PRESSURE SLOWLY MOVES EAST TOWARDS THE UPPER
MISSISSIPPI VALLEY...AND A SFC TROUGH DEVELOPS IN THE LEE OF THE
MONTANA ROCKIES AHEAD OF A LONG WAVE TROUGH MOVING INTO ALBERTA.
LATEST 12Z MODELS HAVE AGAIN SLOWED DOWN THE EASTWARD PROGRESSION
OF THE SURFACE TROUGH OVER EASTERN MONTANA...AND NOW KEEP ALL
PRECIPITATION OFF TO OUR WEST THROUGH SUNDAY MORNING. AS A RESULT
I HAVE REMOVED ALL MENTION OF THUNDERSTORMS THROUGH 18Z SUNDAY.
SHORT WAVE MID LEVEL RIDGE MOVING ACROSS THE REGION ON SUNDAY WILL
BRING WARMER AIR TO WEST AND CENTRAL NORTH DAKOTA...WITH DAYTIME
HIGHS WARMING BACK TOWARDS THE 80 DEGREE MARK WEST AND MID TO
UPPER 70S CENTRAL. WE START TO SEE INCREASING INSTABILITY OVER THE
FAR WESTERN COUNTIES SUNDAY AFTERNOON AS RETURN FLOW CONTINUES
HELPING LOW LEVEL MOISTURE MOVE BACK INTO THE NORTHERN PLAINS.
WHILE I HAVE KEPT SOME MENTION FOR AFTERNOON CONVECTION IN THE
FORECAST ACROSS THE WEST...12Z NAM/GFS BUFFER SOUNDINGS INDICATE
WE WILL BE STRONGLY CAPPED SO WILL CONSIDER TRENDING SUNDAY
AFTERNOON DRY WITH FUTURE FORECAST PACKAGES.
AS THE RIDGE CONTINUES EASTWARD...FLOW ALOFT WILL TRANSITION TO MORE
WEST/SOUTHWESTERLY SUNDAY NIGHT THROUGH MONDAY AND INTO MONDAY NIGHT
ALONG WITH FAVORABLY INSTABILITY FOR THUNDERSTORMS SPREADING ACROSS
THE STATE. COMBINED WITH THE SURFACE TROUGH PUSHING EAST ACROSS THE
DAKOTAS...EXPECT TO SEE A RATHER ACTIVE CONVECTIVE PERIOD FROM
LATE SUNDAY NIGHT THROUGH MONDAY EVENING. AS FAR AS SEVERE
WEATHER...LINGERING CLOUDS FROM SUNDAY NIGHTS EXPECTED CONVECTION
COULD VERY WELL LIMIT THE SEVERE POTENTIAL...FOR MONDAY.
HOWEVER...LATEST MODELS ARE NOW INCREASING THE POTENTIAL FOR
SCATTERED STRONG TO SEVERE STORMS...ESPECIALLY MONDAY
AFTERNOON/EVENING. WILL MENTION THIS POSSIBILITY IN THE HWO. IT
SHOULD BE NOTED THE 12Z NAM...WHILE A FAST OUTLIER...WOULD FAVOR
THE MOST ACTIVE PERIOD LATE SUNDAY EVENING THROUGH MONDAY
AFTERNOON. THUS WILL NEED TO KEEP AN EYE ON THE MODEL TRENDS THE
NEXT FEW PERIODS.
AFTER THIS SHORT PERIOD OF ACTIVE WEATHER...MODELS FORECAST A RETURN
TO A QUIETER WEATHER PERIOD TUESDAY INTO MID-WEEK WITH NORTHWEST
FLOW ALOFT REDEVELOPING FOLLOWED BY ANOTHER S/WV RIDGE. WHILE CANNOT
RULE OUT ISOLATED SHOWERS/THUNDERSTORMS...THE OVERALL PATTERN
TUESDAY-THURSDAY WOULD NOT SUPPORT WIDESPREAD PRECIPITATION. AS WE
PROCEED TOWARDS THE END OF THE WORK WEEK INTO THE FOLLOWING
WEEKEND...BOTH THE 12Z GFS/ECMWF DEPICT ANOTHER ACTIVE WEATHER
PERIOD DEVELOPING AS FLOW BECOMES QUASI-ZONAL AGAIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1159 AM CDT FRI JUL 26 2013
A SCT TO BKN CUMULUS CLOUDS WILL COVER ALL THE AERODROMES THROUGH
03Z SATURDAY. ALTHOUGH VFR CIGS ARE EXPECTED...CLOUD BASES WILL
RANGE BETWEEN 3500FT TO 7000FT ABOVE GROUND LEVEL. SKIES WILL GRADUALLY
CLEAR TOWARD 06Z SATURDAY WITH VFR CONDITIONS CONTINUING THROUGH SATURDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
LONG TERM...NH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
233 PM PDT FRI JUL 26 2013
.DISCUSSION...ANOTHER HOT DAY IS OCCURRING ACROSS THE AREA...THOUGH
TEMPERATURES HAVE COOLED A BIT...ABOUT 5 DEGREES COOLER THAN
YESTERDAY. INSTABILITY AND AMPLE UPPER MOISTURE IS HELPING TO
GENERATE THUNDERSTORMS EAST OF THE CASCADES AND OVER NORTHERN
CALIFORNIA. THE AREAS EXPECTED TO GET THE MOST THUNDERSTORM
ACTIVITY ARE MODOC AND LAKE COUNTIES...WITH THE HRRR SHORT-RANGE
GUIDANCE AND OBSERVED LIGHTNING STRIKES SUPPORTING THIS. A RED
FLAG WARNING AT RFW HAS BEEN ISSUED FOR LAKE...EASTERN MODOC...AND
EXTREME EASTERN KLAMATH COUNTIES. WEST OF THE CASCADES CONVECTIVE
INHIBITION...AS IS SHOWN IN FORECAST SOUNDINGS AND IN THE CURRENT
CLOUD DEVELOPMENT WHICH IS LIMITED IN VERTICAL DEVELOPMENT.
A COOLDOWN AND TRANSITION TOWARD NORMAL OR JUST BELOW NORMAL
TEMPERATURES WILL BE UNDERWAY TONIGHT INTO NEXT WEEK. TOMORROW THERE
IS ONE MORE CHANCE OF THUNDERSTORMS OVER NORTHERN CALIFORNIA WITH
LINGERING INSTABILITY THERE. ELSEWHERE...WESTERLIES AND STABLE
CONDITIONS WILL PREVENT THUNDERSTORM ACTIVITY. THE MARINE LAYER
WILL DEEPEN AND SEND CLOUDS FURTHER INLAND OVER THE NEXT COUPLE
MORNINGS...REACHING ROSEBURG BY SUNDAY MORNING. FOG WILL BEGIN TO
SUBSIDE AT THE COAST AS THE MARINE LAYER DEEPENS AND CLOUD BASES
RISE SOME...WITH DRIZZLE.
DRY AND COOL WEATHER WILL CONTINUE THROUGH EARLY NEXT WEEK...AND BY
WEDNESDAY MORNING DRIZZLE MAY AFFECT THE NORTH COAST AREA AROUND
NORTH BEND. THUNDERSTORMS ARE NOT EXPECTED AT THIS TIME AND HAVE
KEPT THEM OUT OF THE EXTENDED PORTION OF THE FORECAST...WITH
SOUTHWEST AND WEST FLOW ALOFT...SIGNALING A CONTINUING STABLE AIR
MASS.
&&
.AVIATION...MARINE STRATUS HAS CLEARED FROM THE COASTAL AREAS
THIS MORNING...BUT LOW CLOUDS WILL RETURN TO THE SAME AREAS OF
COOS AND WESTERN DOUGLAS COUNTY AROUND 03Z THIS
EVENING...PERSISTING INTO SATURDAY MORNING. INLAND...VFR IS
EXPECTED OVER THE NEXT 24 HOURS. THUNDERSTORMS WILL CONTINUE THIS
AFTERNOON AND EVENING FROM NORTHERN CALIFORNIA NORTHEASTWARD INTO
KLAMATH AND LAKE COUNTIES. GUSTY AND VARIABLE WINDS WILL ACCOMPANY
THUNDERSTORMS.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR ORZ030.
RED FLAG WARNING UNTIL 8 PM PDT SATURDAY FOR ORZ031.
CA...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR CAZ085.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM PDT SATURDAY FOR
PZZ356.
GALE WARNING FROM 11 AM TO 8 PM PDT SATURDAY FOR PZZ356.
HAZARDOUS SEAS WARNING UNTIL 11 PM PDT SUNDAY FOR PZZ356.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT SUNDAY FOR
PZZ350-370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT SUNDAY
FOR PZZ350.
HAZARDOUS SEAS WARNING UNTIL 5 AM PDT SUNDAY FOR PZZ370.
GALE WARNING UNTIL 11 PM PDT SUNDAY FOR PZZ376.
HAZARDOUS SEAS WARNING UNTIL 11 AM PDT MONDAY FOR PZZ376.
$$
NSK/NSK/BPN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
220 PM EDT FRI JUL 26 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA TODAY WILL MOVE OFFSHORE TONIGHT. A
COLD FRONT WILL APPROACH THE REGION SATURDAY...AND WILL CROSS THE
AREA SUNDAY. A LARGE HIGH PRESSURE SYSTEM WILL COVER MUCH OF THE
EASTERN UNITED STATES ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM EDT THURSDAY...
SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT NEARLY
ALL FOG HAS BURNED OFF THIS MORNING...ALTHOUGH A BROKEN CANOPY OF
LOW AND MID CLOUDS CONTINUES TO LINGER ACROSS THE AREA...
PARTICULARLY ALONG THE BLUE RIDGE. RADAR IS CLEAR AT THE MOMENT.
TEMPERATURES CONTINUE TO WARM INTO THE UPPER 60S AND LOW 70S
AFTER LAST NIGHTS SOMEWHAT UNSEASONABLY COOLER TEMPERATURES.
FOR TODAY...EXPECT A REDEVELOPMENT OF ONLY SPOTTY SHOWERS AND
THUNDERSTORMS...MAINLY ALONG THE BLUE RIDGE. STUCK CLOSE TO THE
WRF MODEL SOLUTION COMPARED TO THE RAP MODEL...WHICH APPEARS
OVERDONE ON THE COVERAGE. MAY SEE ONE OR TWO LOCALLY STRONG
THUNDERSTORMS DURING EARLY EVENING...HOWEVER MOST ACTIVITY SHOULD
REMAIN MORE ON THE WEAK SIDE. SHOWERS AND STORMS WILL DIMINISH
ACROSS VIRGINIA AFTER SUNSET...HOWEVER WITH WINDS BECOMING
INCREASINGLY SOUTHWESTERLY AHEAD OF AN APPROACHING COLD
FRONT...WILL LIKELY SEE SHOWERS LINGER INTO EARLY SATURDAY ACROSS
THE MOUNTAINS AND FOOTHILLS OF NORTH CAROLINA.
WITH WINDS BECOMING MORE SOUTHERLY...WILL SEE 850 MB TEMPERATURES
WARM INTO THE +14 TO +16 RANGE BY 00Z/8PM TONIGHT. USED A BLEND OF
MET/MAV GUIDANCE FOR HIGHS TODAY AND LOWS TONIGHT.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 400 AM EDT FRIDAY...
DEEP UPPER TROUGH TRAVELS EAST FROM THE GREAT LAKES INTO THE
NORTHEAST DURING THE PERIOD. INITIALLY TRIMMED BACK POPS SATURDAY
MORNING THEN KEPT LIKELY TO CAT POPS SATURDAY AFTERNOON INTO
SATURDAY NIGHT. GFS STILL SHOWED GOOD DYNAMICS WITH DECENT 25-30KT
LLJ/LOW-LEVEL SHEAR INDICATED WITH UPPER DIFFLUENCE PRESENT ACROSS
WESTERN PORTIONS OF THE REGION. LOCALIZED HEAVY RAINFALL WILL ALSO
BE A POSSIBILITY WITH STRONGER THUNDERSTORMS...BUT OVERALL
WIDESPREAD FLOODING NOT EXPECTED. WITH THE MOVEMENT OF THE
SHORTWAVE...SHIFT HIGHER POPS TO THE EAST SATURDAY NIGHT INTO
SUNDAY. DRY AIR PUSHES EAST ACROSS THE REGION ON SUNDAY INTO SUNDAY
NIGHT. UPPER TROUGH SHIFTS EAST OF THE REGION MONDAY. WEAK HIGH
PRESSURE BUILDS ACROSS THE REGION FROM THE OHIO VALLEY. REMOVED THE
MENTION OF THUNDERSTORMS FROM THE EAST AND SOUTH ON MONDAY. THE
COOLER AIRMASS REACHES THE PIEDMONT MONDAY NIGHT WITH LOWS DROPPING
INTO THE LOWER 60S IN SOUTHSIDE.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 400 AM EDT FRIDAY...
SLOWED THE RETURN OF MOISTURE TUESDAY BUT ALLOWED FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE
WEST ESPECIALLY ALONG THE SOUTHERN BLUE RIDGE.
AFTER TUESDAY...A MUCH MORE UNSETTLED PATTERN RETURNS. THE
SUBTROPICAL RIDGE AMPLIFIES ACROSS THE CENTRAL/SOUTHERN PLAINS WITH
A ZONAL FLOW NOTED NORTH OF ABOUT 35 DEG LAT ACROSS MUCH OF THE U.S.
AN ALMOST ENDLESS SERIES OF DISTURBANCES TRACK WITHIN THIS ZONAL
FLOW AND IMPINGE ON AN INCREASINGLY WARM/HUMID AIR MASS ACROSS THE
REGION. 850MB TEMPS WILL WARM TOWARD +15 TO +18C BY THE END OF THE
WEEK.
WEDNESDAY APPEARS TO BE THE DAY WITH THE BEST POTENTIAL FOR
WIDESPREAD SHRA/TSRA ACTIVITY. IT APPEARS TO BE MORE OF A RAIN EVENT
THAN A SEVERE THUNDERSTORM EVENT AT THIS POINT AS INSTABILITY IS
MARGINAL. AS WE MOVE TOWARD THE WEEKEND...THERE IS SOME INDICATION
THAT A SERIES OF MCS/THUNDERSTORM COMPLEXES COULD EVOLVE ACROSS THE
MIDWEST/OHIO VALLEY AND SPREAD SE TOWARD OUR REGION. NOTABLE
INSTABILITY IS IN PLACE AT THAT TIME...SO WE WILL CERTAINLY NEED TO
KEEP AN EYE ON THIS INCREASINGLY VOLATILE PATTERN.
TEMPERATURES WILL START OUT WELL BELOW NORMAL...THEN TREND TOWARD
NORMAL FOR THE REMAINDER OF THE WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 200 PM EDT FRIDAY...
SURFACE OBSERVATIONS INDICATE VFR CONDITIONS AREAWIDE AS THE
STRATOCU FIELD HAS BECOME MORE SCATTERED IN NATURE...WITH BASES
ACROSS MOST AREAS NOW ABOVE 3KFT. A FEW SHOWERS ARE DEVELOPING
ALONG THE BLUE RIDGE NEAR THE NC/VA BORDER...HOWEVER GROWTH OF
THIS ACTIVITY IS WEAK. HIGH PRESSURE CONTINUES TO MOVE OFFSHORE
THIS AFTERNOON...MAKING FOR A LIGHT SOUTHEASTERLY FLOW OUTSIDE OF
LOCAL EFFECTS.
SHORT RANGE MODELS REMAIN IN AGREEMENT THAT SHOWER ACTIVITY WILL
REMAIN CONFINED MAINLY TO THE BLUE RIDGE THIS AFTERNOON AND
EVENING...WITH A FEW SHOWERS DEVELOPING INTO THUNDERSTORMS DURING
LATE AFTERNOON AND EARLY EVENING. CONVECTION SHOULD REMAIN
SMALL...BUT WILL ALSO BE SLOW MOVING AND PRODUCE LOCALLY HEAVY
RAIN THAT CAN REDUCE VISIBILITIES TO LESS THAN 1SM.
WINDS WILL BECOME MORE SOUTHERLY OVERNIGHT AS A COLD FRONT
APPROACHES THE AREA...AND EXPECT SHOWER ACTIVITY AND MVFR CEILINGS
TO RIDE IN FROM SOUTH SOUTHWEST AFTER MIDNIGHT. MAY SEE A FEW
PATCHES OF FOG EARLY IN THE NIGHT...HOWEVER INCREASING CLOUD COVER
AND A TIGHTENING PRESSURE GRADIENT WILL KEEP FOG DEVELOPMENT
HIGHLY LIMITED.
THUNDERSTORM ACTIVITY WILL BE SCATTERED ON SATURDAY AFTERNOON AND
EVENING...MORE SO FROM ROA WESTWARD AS THE COLD FRONT APPROACHES
FROM THE WEST. A FEW STORMS WILL BECOME SEVERE...PRODUCING STRONG
WINDS AND LOCALLY HEAVY RAIN...IN ADDITION TO MVFR/IFR CEILINGS.
ON SUNDAY...THE FRONT WILL CROSS THE AREA WITH MORE SHOWERS AND
THUNDERSTORMS. THERE IS STILL A CHANCE OF LOCALIZED SUB-VFR
CONDITIONS EAST OF THE BLUE RIDGE.
MONDAY INTO TUESDAY...SURFACE HIGH PRESSURE BUILDS OVERHEAD. THIS
WILL YIELD LIGHT WINDS AND LIMITED CLOUD COVER...BUT NIGHTTIME AND
EARLY MORNING FOG AND STRATUS WILL BE POSSIBLE THANKS TO PLENTY OF
BOUNDARY LAYER MOISTURE IN PLACE AFTER THE RAIN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/NF
SHORT TERM...KK
LONG TERM...KK/RAB
AVIATION...AMS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1115 AM CDT FRI JUL 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT FRI JUL 26 2013
THE MAIN FOCUS FOR TODAY IS ON THE PASSING COLD FRONT AND THE
CHANCES FOR CONVECTION ALONG IT.
CURRENTLY...THE FIRST IN A SERIES OF MID LEVEL SHORT WAVE TROUGHS
IN FAR SOUTHERN ONTARIO IS PROPAGATING EAST ALONG THE SOUTHERN
PERIPHERY OF A BROADER TROUGH THAT IS IN PLACE ACROSS MUCH OF
SOUTHEASTERN CANADA. THIS LEAD SHORTWAVE HAS BEEN GRADUALLY
WEAKENING AHEAD OF THE MAIN VORT MAX PER THE LATEST WATER VAPOR IR
IMAGERY AND BECOMING MORE EAST TO WEST ORIENTED ACROSS NORTH
CENTRAL WISCONSIN. THIS FEATURE HAS HELPED TO KEEP A BAND OF
SHOWERS/STORMS GOING ACROSS THIS REGION EARLY THIS MORNING.
DOWN AT THE SURFACE...A BROAD AREA OF LOW PRESSURE IS IN PLACE
FROM LAKE SUPERIOR WEST INTO NORTHERN MINNESOTA WITH A COLD FRONT
DROPPING SOUTH THROUGH EASTERN/SOUTH CENTRAL MINNESOTA ON INTO
NORTHWEST IOWA. 26.07Z RAP ANALYSIS SHOWS AN INSTABILITY AXIS OF
500-1000 J/KG OF 0-3KM MUCAPE IN PLACE AHEAD OF THIS FRONT FROM
NORTHWEST IOWA INTO NORTH CENTRAL WISCONSIN. THIS COMBINATION OF
THE FRONT AND INSTABILITY HAS BEEN ENOUGH TO FUEL SOME SCATTERED
CONVECTION ACROSS MINNESOTA EARLY THIS MORNING.
ALL INDICATIONS ARE THAT THE TROUGH/FRONT ARE GOING TO PASS
THROUGH RATHER QUICKLY TODAY AS THIS MAIN MID LEVEL TROUGH WRAPS
UP. THERE DOES APPEAR TO BE A BRIEF WINDOW FOR THE DEVELOPMENT OF
SEVERE THUNDERSTORMS IN WESTERN WISCONSIN LATER THIS MORNING AND
INTO THE EARLY AFTERNOON AS INSTABILITY BUILDS INTO THE
1000-1500J/KG RANGE AND A 500MB JET STREAK PUSHES INTO CENTRAL
WISCONSIN. MUCH OF THE 26.00Z TO 26.06Z MESO-GUIDANCE SUGGESTS
THAT THE COLD FRONT IS ALREADY GOING TO BE INTO CENTRAL WISCONSIN
BY 17-19Z WITH ANY SEVERE POTENTIAL COMING AHEAD OF THIS FRONT. AM
NOT EXPECTING A WIDESPREAD SEVERE OUTBREAK BY ANY MEANS...BUT THE
INCREASING INSTABILITY AND INCREASING MID LEVEL WINDS WILL HELP TO
ORGANIZE A FEW UPDRAFTS AND SHOULD PRODUCE A FEW SEVERE STORMS
WITH LARGE HAIL THE MAIN HAZARD DUE TO THE LOW FREEZING LEVELS.
THE HIGHER SEVERE CHANCES WILL BE INTO CENTRAL/EASTERN WISCONSIN
WHERE THERE WILL BE A LONGER PERIOD OF WARMING BEFORE THE STORMS
GET IN.
AS THE CORE OF THE MID LEVEL TROUGH TRACKS THROUGH THIS
AFTERNOON...A SECONDARY COLD FRONT/TROUGH WILL DROP SOUTH ACROSS
THE REGION AND COULD BE A FOCUS FOR SOME SHOWER DEVELOPMENT. WINDS
WILL PICK UP AND TEMPERATURES WILL DROP BEHIND BOTH FRONTS TO MARK
THE BEGINNING OF AN UNSEASONABLY COOL PERIOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 AM CDT FRI JUL 26 2013
THE FOCUS THEN SHIFTS TO HOW COLD IT WILL BE THIS WEEKEND AS AN
ANOMALOUSLY COOL AIR MASS GETS PULLED DOWN INTO THE REGION FROM
NORTH CENTRAL CANADA. THE 26.00Z NAM/GFS/ECMWF 850MB TEMPERATURE
ANOMALIES AT -1.5 TO -2.5 DEVIATIONS FROM THE NORM WHICH TYPICALLY
INDICATE NEAR RECORD TO RECORD COLD TEMPERATURES. WITH QUESTIONS
IN THE AMOUNT OF CLOUD COVER LINGERING...HAVE NOT GONE BELOW
RECORD LOWS OR RECORD LOW MAXIMUM TEMPERATURES BUT HAVE KEPT THEM
CLOSE. AT LSE...THE RECORD LOW HIGH FOR SATURDAY IS 69 AND FOR
SUNDAY IS 66 WHILE THE RECORD LOWS ARE 48 ON SATURDAY/50 ON
SUNDAY. AT RST...THE LOW MAX FOR SATURDAY IS 64/SUNDAY IS 63 WHILE
THE RECORD LOW IS 47 ON BOTH SATURDAY AND SUNDAY. 26.00Z FORECAST
SOUNDINGS SHOW SOME INSTABILITY DEVELOPING IN THE AFTERNOON TO
WHERE SOME DIURNALLY DRIVEN SHOWERS SHOULD DEVELOP...PARTICULARLY
IN WESTERN WISCONSIN WHICH WILL BE CLOSER TO THE UPPER LEVEL
TROUGH.
AS THE MID LEVEL LOW WOBBLES EASTWARD INTO THE EARLY PORTION OF
NEXT WEEK...THE NEXT MID LEVEL TROUGH...WHICH IS CURRENTLY IN FAR
SOUTHWEST CANADA...WILL TRACK EAST ACROSS CANADA. INSTABILITY WILL
BE ON THE INCREASE ON THE WESTERN PERIPHERY OF THE SURFACE RIDGE
WITH SOME SMALL CHANCES FOR CONVECTION MONDAY NIGHT THROUGH
THURSDAY. NOT OVERLY CONFIDENT THAT ALL OF THESE PRECIPITATION
CHANCES ARE NEEDED...BUT WITH THE LINGERING TROUGH NEARBY CAN NOT
RULE THEM OUT. A GRADUAL WARMING TREND IS EXPECTED WITH 850MB
TEMPERATURES RISING FROM +4C ON SATURDAY TO +13C BY TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1115 AM CDT FRI JUL 26 2013
A COLD FRONT HAS SLIPPED EAST OF THE AREA...WHICH LED TO SOME BRIEF
CLEARING OF THE LOW CLOUD DECK. HOWEVER...WITH THE SFC/UPPER LEVEL
LOW HANGING OUT ACROSS THE GREAT LAKES...CYCLONIC FLOW ON THE
BACKSIDE WAS USHERING IN ANOTHER MVFR/VFR CLOUD MASS WHICH WILL
QUICKLY COVER KRST/KLSE EARLY THIS AFTERNOON. A FEW -SHRA WILL BE
POSSIBLE...BUT MOST OF THE SHRA/TS ACTIVITY WILL BE ALONG THE COLD
FRONT...AND THUS EAST OF THE TAF SITES.
THE BIG AVIATION QUESTION IS HOW LONG WILL THE MVFR CIGS STICK
AROUND. LIKELY GET SOME DIURNAL INCREASE IN HEIGHTS AS THE AFTERNOON
WEARS ON...BUT RAP/NAM/GFS ALL SUGGEST LOW LEVEL MOISTURE WILL
REMAIN IN PLACE TONIGHT-SATURDAY. DIURNAL CLOUD ELEMENTS WILL
DISSIPATE WITH THE LOSS OF DAYTIME HEATING THIS EVENING...BUT THINK
A LOT OF THE CLOUDS WILL STAY INTACT. GOING TO HOLD ONTO BKN CIGS
FOR NOW...BUT ADJUSTMENTS WILL NEED TO BE MADE IF SUBSIDENCE WINS
OUT TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION.....RIECK