Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/15/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
350 PM MST SAT SEP 13 2014
.SYNOPSIS...
AN INCREASE IN MOISTURE FROM THE EAST WILL MAINTAIN A SLIGHT CHANCE
THUNDERSTORMS THROUGH MONDAY. DEEPER TROPICAL MOISTURE WILL BEGIN TO
MOVE IN TUESDAY FOR A SIGNIFICANT INCREASE IN STORM CHANCES THE REST
OF NEXT WEEK.
&&
.DISCUSSION...
REST OF TODAY THROUGH MONDAY...
TIGHT SURFACE PRESSURE GRADIENT ACROSS ARIZONA AND NEW MEXICO WITH
LOWER PRESSURE OVER THE MOHAVE DESERT AND HIGH PRESSURE OVER THE
PLAINS. THIS IS DUE TO A BACK DOOR COLD FRONT SPILLING OVER THE
SOUTHERN CONTINENTAL DIVIDE. BREEZY EASTERLY WINDS HAVE RESULTED AS
HAVE HIGHER DEW POINTS AND COOLER TEMPERATURES...MOST NOTICEABLY
OVER EASTERN PORTIONS OF OUR FORECAST AREA. THE INCREASED MOISTURE
HOWEVER LOOKS TO BE OFFSET BY AN INCREASE IN CIN...AT LEAST OVER
SOUTHERN ARIZONA. NCEP MODELS AS WELL AS HRRR AND LOCAL HI-RES
MODELS ARE NOT VERY ENTHUSIASTIC ABOUT STORM ACTIVITY THE REST OF
TODAY AND TONIGHT FOR OUR AREA. HOWEVER...WITH THE MOISTURE THERE IS
A SLIGHT CHANCE OF OUTFLOW FROM DISTANT STORMS KICKING OFF A
STORM...MAINLY EAST OF THE LOWER COLORADO RIVER VALLEY. FOR SUNDAY
AND MONDAY...THE MODELS AGREE ON THE IDEA OF A SLOW WARMING OF THE
BOUNDARY LAYER TO REDUCE THE CAP BUT NO INCREASE IN MOISTURE...EVEN
DECREASING A BIT. SO SLIGHT CHANCES CONTINUE. ONE DIFFERENCE MIGHT
BE FOR MONDAY AS AN ANTICYCLONE BECOMES CENTERED OVER SOUTHERN
NEVADA LEADING TO NORTHEASTERLY STEERING FLOW...PER GFS...WHICH
COULD AID THE ADVECTION OF MOGOLLON RIM STORMS INTO OUR HIGHER
TERRAIN ZONE EAST OF PHOENIX. THE PRESSURE GRADIENT CONTINUES SUNDAY
FOR MORE BREEZINESS BEFORE WEAKENING MONDAY. MEANWHILE...HURRICANE
ODILE CURRENTLY SEVERAL HUNDRED MILES SOUTH-SOUTHEAST OF THE
SOUTHERN TIP OF BAJA IS FORECAST TO MOVE NORTHWESTWARD WITH THE EYE
GETTING FAIRLY CLOSE TO CABO SAN LUCAS LATE SUNDAY NIGHT/EARLY
MONDAY MORNING.
TUESDAY THROUGH SATURDAY...
MODELS INDICATE SOMETHING OF A GULF SURGE...MOST LIKELY DRIVEN BY
HURRICANE ODILE...MOVING INTO OUR FORECAST AREA BY TUESDAY. POPS GO
UP A BIT DUE TO INCREASED MOISTURE AND GREATER LIKELIHOOD OF
MOUNTAIN STORMS BUT THERE MAY BE SOME BOUNDARY LAYER COOLING WHICH
HURTS INSTABILITY OVER THE LOWER ELEVATIONS. 12Z GFS AND ECMWF BEGIN
DIVERGING MORE NOTICEABLY IN THEIR POSITIONING OF ODILE AS WELL AS
THE ANTICYCLONE TO THE NORTH AND THE NORTHEAST PACIFIC TROUGH. THE
ECMWF IS A BIT MORE AMPLIFIED WITH THE FLOW AND HAS THE MID LATITUDE
ROSSBY WAVE A BIT FURTHER WEST WITH ODILE CLOSER TO THE BAJA COAST.
IT BRINGS REMNANTS OF ODILE INLAND BY FRIDAY. THE 12Z GFS TRACKS
ODILE FURTHER WEST. HOWEVER...THE GFS HAS A MORE DISTINCT SHORT WAVE
MOVING NORTHWARD INTO ARIZONA WEDNESDAY NIGHT AND THURSDAY BECAUSE
IT HAS THE ANTICYCLONE FURTHER EAST. THE NATIONAL HURRICANE CENTER
FORECAST IS CLOSER TO THE ECWMF POSITION. A QUICK LOOK AT THE 18Z
GFS SHOWS THAT IT NOW LOOKS A LOT MORE LIKE THE ECMWF. IN
SHORT...THEY BOTH ARE INDICATING THAT THE BEST CHANCES FOR STORMS
AND ASSOCIATED FLOODING POTENTIAL IS IN THE WEDNESDAY THROUGH FRIDAY
TIME FRAME. IT SHOULD BE NOTED THAT NEITHER MODEL HAS ESPECIALLY
IMPRESSIVE MODEL RUN TOTAL PRECIP ACCUMULATIONS CONSIDERING THE
ABUNDANT PRECIPITABLE WATER THAT WILL BE AVAILABLE. LIKEWISE WITH
THE WPC FORECASTS. FORECASTS REFLECT POPS THAT ARE SUBSTANTIALLY
ABOVE CLIMO ALONG WITH COOLER TEMPS. FAR TOO EARLY FOR FLASH FLOOD
WATCHES BUT WILL CONTINUE TO EVALUATE.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...AND SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
SCATTERED TO BROKEN CLOUD DECKS GENERALLY AOA 12KFT...AND WINDS
WILL CONTINUE TO FAVOR EAST-SOUTHEASTERLY DIRECTIONS AT ALL
TERMINALS THIS EVENING/OVERNIGHT INTO SUNDAY. EXPECT LOCAL GUSTS UP
TO 20KT OR SO AT TIMES...MAINLY BETWEEN 15Z AND 20Z SUNDAY. STORM
CHANCES ARE SLIGHT FOR THE DESERT ELEVATIONS...MORE FAVORED OVER
MOUNTAINS OF NORTHERN/EASTERN AZ DURING THE PERIOD. STILL POSSIBLE
TO HAVE OUTFLOW WINDS THIS EVENING - FROM 02Z TO 05Z - FROM ANY
DISTANT STORM...BUT SIGNIFICANT WIND SHIFTS ARE NOT INDICATED IN THE
TAF AT THIS TIME.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
MOISTURE WILL STEADILY INCREASE ACROSS THE AREA DURING THE WEEK WITH
A NOTEWORTHY INCREASE IN HUMIDITIES TAKING PLACE ON WEDNESDAY.
SHOWERS WILL INCREASE IN COVERAGE WEDNESDAY NIGHT THROUGH FRIDAY
WITH SOME AREAS POTENTIALLY LOOKING AT PERIODS OF HEAVY RAINFALL. AS
SUCH...AFTERNOON HUMIDITIES WILL REMAIN ELEVATED WITH GOOD TO
EXCELLENT RECOVERIES EXPECTED. WINDS SHOULD BE LIGHT DURING THE WEEK
OUTSIDE OF THUNDERSTORM INDUCED OUTFLOWS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
AVIATION...MEYERS
FIRE WEATHER...MEYERS/LEINS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1128 PM MDT FRI SEP 12 2014
.UPDATE...
ISSUED AT 549 PM MDT FRI SEP 12 2014
LOOKING AT SAT PIX...AND HI RES RH FIELDS IN THE LOWER LVLS OF THE
ATMOSPHERE AND PRGD SOUNDINGS...HAVE PLAYED UP MORE LOW CLOUDS FOR
TONIGHT THAN WERE IN EARLIER FCST PRODUCTS. FCST ARE BEING UPDATED
AS I WRITE.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 242 PM MDT FRI SEP 12 2014
WIDESPREAD LOW CLOUDS CONTINUE TO COVER THE SERN CO PLAINS THIS
AFTERNOON...WITH TEMPS IN THE 40S. THE REST OF THE FORECAST AREA
HAS HAD MOSTLY SUNNY SKIES...WITH SOME CONVECTIVE CLOUDS DEVELOPING
OVER THE SRN MTNS AND SAN LUIS VALLEY. THERE CONTINUES TO BE SOME
SPOTTY LIGHT DRIZZLE IN LOCATIONS NR THE ERN MTNS. THE NAM HAS WAY
OVERDONE THE PCPN OVR THE SERN PLAINS FOR TODAY...WITH THE HRRR
BEING MORE REASONABLE. FOR THIS EVENING AND OVERNIGHT THE NAM
PRINTS OUT SOME ISOLD PCPN OVR THE SRN CO MTNS. THE HRRR IS DRY FOR
THIS EVENING. IT IS POSSIBLE THAT A FEW SHOWERS COULD DEVELOP FOR
THE EVENING HOURS...BUT FOR NOW WL LEAVE SILENT POPS IN THE
FORECAST. THE NAM AND HRRR ARE STILL SHOWING A DECREASE IN LOW LEVEL
CLOUD COVER LATER THIS AFTERNOON AND EARLY THIS EVENING...BUT NOT
SEEING ANY EVIDENCE OF THIS IN THE SATELLITE IMAGES YET. BOTH MODELS
THEN SHOW THE POTENTIAL FOR LOW CLOUD REFORMING OVR PORTIONS OF THE
PLAINS BY LATE EVENING. OVERNIGHT LOW TEMPS ARE EXPECTED TO BE IN
THE UPPER 30S TO LOWER 40S OVR THE SERN PLAINS...THE COLDEST AREAS
LOOK TO BE NORTHERN PORTIONS OF PUEBLO COUNTY...EL PASO AND CROWLEY
COUNTIES. LOWS IN THESE LOCATIONS LOOK LIKE THEY WL BE IN THE LOWER
30S. HAVE DECIDED TO ISSUE A FROST ADVISORY FOR THESE COUNTIES JUST
IN CASE THERE ARE POCKETS OF FROST.
MODELS ARE INDICATING THAT THE LOW CLOUDS SHOULD DISSIPATE BY LATE
MORNING ON SATURDAY WITH A GOOD WARM UP IN STORE. HIGHS ON SAT OVR
THE SERN PLAINS SHOULD BE IN THE 70S...WITH MID TO UPPER 70S IN THE
SAN LUIS VALLEY. GENERALLY DRY WESTERLY FLOW ALOFT IS EXPECTED OVR
THE FORECAST AREA. THE NAM AGAIN PRINTS OUT SOME LIGHT PCPN OVR THE
SRN CO MTNS AND SAN LUIS VALLEY SAT AFTERNOON...SO WL LEAVE SOME
ISOLD POPS IN THE FORECAST FOR THE SW MTNS AND THE SANGRES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 242 PM MDT FRI SEP 12 2014
MODELS IN GOOD AGREEMENT THROUGH THE EXTENDED PERIOD WITH SMALL
ENSEMBLE SPREADS AND HIGHER FORECAST CONFIDENCE.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...FLAT ZONAL WESTERLY FLOW
WILL PERSIST ACROSS COLORADO THROUGH THIS PERIOD AS AN UPPER RIDGE
BEGINS TO BUILD ALONG THE WEST COAST AND SHORTWAVE TROUGH DROPS
SOUTH OUT OF CANADA INTO THE NORTHERN PLAINS. EXPECT ISOLATED
SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS ON SATURDAY EVENING
TO DISSIPATE AROUND SUNDOWN WITH LOSS OF DAYTIME INSTABILITY.
OVERNIGHT LOWS WILL FALL INTO THE MID TO UPPER 40S FOR MUCH OF THE
REGION. A WEAK DISTURBANCE EMBEDDED IN THE WESTERLY FLOW ALOFT
WILL MOVE ACROSS THE STATE ON SUNDAY AFTERNOON. ANOTHER ROUND OF
ISOLATED TO SCATTERED MOUNTAIN SHOWERS AND THUNDERSTORMS ARE
EXPECTED...WHICH SHOULD DISSIPATE ON SUNDAY EVENING. HIGHS SUNDAY
WILL REACH INTO THE 80S FOR THE LOWER ELEVATIONS.
MONDAY AND MONDAY NIGHT...MODELS IN GOOD AGREEMENT WITH A STRONG
COLD FRONT DROPPING SOUTH ACROSS THE EASTERN PLAINS ON MONDAY
MORNING. THE NAM IS THE FASTEST SOLUTION...WITH IT CLEARING SOUTH
INTO NEW MEXICO BY 12Z...WHILE THE ECMWF AND GFS ARE ABOUT 6 HOURS
SLOWER. FEEL THAT A BIT FASTER SOLUTIONS WILL LIKELY PLAY OUT AND
FOLLOWED THE NAM FRONTAL PROGRESSION. EXPECT LOW LEVEL FLOW TO
TURN EASTERLY AND USHER IN MUCH COOLER AIR INTO THE PLAINS.
UPGLIDE AND MOISTURE BEHIND THE FRONT WILL LIKELY LEAD TO LIGHT
RAIN FOR THE PLAINS THROUGH MONDAY AFTERNOON. WARMER TEMPERATURES
AND GREATER INSTABILITY WILL EXIST OVER THE MOUNTAIN AREAS MONDAY
AFTERNOON AND SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED.
MODELS IN AGREEMENT WITH THE LIGHT RAIN COMING TO AN END FOR THE
PLAINS FROM NORTH TO SOUTH THROUGH THE AFTERNOON HOURS. EXPECT
THUNDERSTORMS OVER THE MOUNTAINS TO DISSIPATE AFTER SUNSET.
TEMPERATURES WILL BE MUCH COOLER BEHIND THE FRONT WITH THE PLAINS
LIKELY ONLY SEEING 60S FOR HIGHS.
TUESDAY THROUGH FRIDAY...THE UPPER PATTERN WILL BECOME AMPLIFIED
ACROSS THE CONUS WITH HIGH PRESSURE BUILDING OVER THE WEST AND A
TROUGH OVER THE EASTERN STATES. THIS WILL PUT SOUTHERN COLORADO
UNDER BROAD NORTHWEST FLOW. EXPECT GENERALLY DRY CONDITIONS ACROSS
THE REGION WITH DAILY AFTERNOON AND EVENING MOUNTAIN CONVECTION
POSSIBLE. TEMPERATURES WILL BE QUICK TO WARM UP WITH 80S FOR THE
LOWER ELEVATIONS THROUGH THE MIDDLE OF THE WEEK.
BY FRIDAY MODELS ARE BRINGING A PIECE OF ENERGY FROM TROPICAL
STORM ODILE WHICH IS FORECAST TO BE OFF THE NORTHERN BAJA COAST BY
FRIDAY. IF THIS DISTURBANCE AND MOISTURE DOES MATERIALIZE...THERE
WILL BE MUCH BETTER CHANCES FOR PRECIPITATION...ESPECIALLY ALONG
THE CONTINENTAL DIVIDE...BY FRIDAY. THIS WILL NEED TO BE
MONITORED. MOZLEY
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1125 PM MDT FRI SEP 12 2014
NOT MUCH CHANGE FOR PREVIOUS THINKING...KCOS AND KPUB WILL LIKELY
REMAIN IN MVFR/IFR CONDITIONS THROUGH TOMOROW MORNING. KCOS
SHOULD CLEAR OUT AOA 16-17Z WHILE KPUB AN HOUR OR SO LATER.
OTHERWISE...VFR CONDITIONS ANTICIPATED.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 8 AM MDT SATURDAY FOR COZ084>086-089.
&&
$$
UPDATE...HODANISH
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
356 AM EDT SAT SEP 13 2014
.SYNOPSIS...
HIGH PRESSURE DOMINATES OVERNIGHT. A QUICK MOVING WEATHER SYSTEM
WILL BRING SCATTERED SHOWERS TO THE AREA LATE SATURDAY AFTERNOON
AND EARLY EVENING. HIGH PRESSURE BRINGS DRY WEATHER WITH SLIGHTLY
BELOW NORMAL TEMPERATURES SUNDAY INTO MONDAY. THE NEXT COLD FRONT
WILL LIKELY BRING A PERIOD OF SHOWERS LATE MONDAY NIGHT INTO
TUESDAY. MAINLY DRY WEATHER EXPECTED NEXT WEDNESDAY THROUGH FRIDAY
WITH SLIGHTLY BELOW NORMAL TEMPERATURES CONTINUING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
130 AM UPDATE...
ADJUSTED SKY COVER GRIDS BASED ON LATEST OBSERVATIONS AND
SATELLITE PICTURES. RAP SEEMS TO HAVE BEST HANDLE ON PATCHES OF
STRATOCUMULUS. ADJUSTED TEMPERATURES STILL A LITTLE COOLER IN SE
ZONES BASED ON LATEST OBSERVED TRENDS.
1015 PM UPDATE...
QUIET NIGHT WITH LITTLE CHANGE NEEDED IN FORECAST. DID LOWER
HOURLY AND MIN TEMPS FOR PORTIONS OF SE MA AND MARTHAS VINEYARD TO
ACCOUNT FOR CURRENT TRENDS AND CLIMATOLOGY. KEPT POP NEAR ZERO
PERCENT THROUGH 8 AM AND JUST MADE A FEW TWEAKS WITH THE SKY COVER
TO BE CONSISTENT WITH CURRENT TRENDS.
630 PM UPDATE...
STRATO-CUMULUS CLOUDS HAVE DISSIPATED EARLY THIS EVENING ACROSS THE
CAPE AND ISLANDS. OTHERWISE...MAINLY CLEAR SKIES WERE IN PLACE
EARLY THIS EVENING OTHER THAN A TOUCH OF HIGH CLOUDINESS.
IDEAL SEP WEATHER ACROSS THE REGION THROUGH THE EVENING WITH MAINLY
CLEAR SKIES...COMFORTABLE TEMPS AND LIGHT WINDS. AFTER
SUNSET...TEMPS WILL FALL FAIRLY QUICKLY GIVEN DRY
ATMOSPHERE...CLEAR SKIES AND LIGHT WINDS. MANY LOCATIONS WILL DIP
INTO THE MU40S TONIGHT INCLUDING PLACES SUCH AS MARTHAS VINEYARD...
NORWOOD AND OTHER INTERIOR EASTERN MA LOCATIONS. ALSO WESTERN MA AND
SOUTHWEST NH SHOULD FALL INTO THE MU40S. ELSEWHERE MINS WILL BE IN
THE LOW TO MID 50S.
TRICKY PART TO THE FORECAST WILL BE IF SOME LOW CLOUDS ARE ABLE TO
DEVELOP NEAR THE COAST TOWARD DAYBREAK. THESE CLOUDS MAY REAPPEAR
TOWARD SUNRISE GIVEN BLYR COOLING OVERNIGHT. THUS COULD SEE SKIES
BECOME PARTLY TO MOSTLY CLOUDY TOWARD DAYBREAK OVER EASTERN MA AND
POSSIBLY INTO RI...BUT CONFIDENCE IS LOW.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
SATURDAY...
DRY TO START THE DAY BUT QUICK MOVING NORTHERN STREAM SHORT WAVE
TROUGH APPROACHES FROM THE WEST. TWO AREAS OF SHOWERS WILL TRACK
ACROSS THE NORTHEAST. FIRST BATCH WILL BE OVER NY STATE AND
NORTHERN NEW ENGLAND WITH PARENT LOW AND ACCOMPANYING LOW TO MID
LEVEL JET. A SECOND AREA OF SHOWERS WILL TRACK SOUTH OF NEW
ENGLAND AS LAST NIGHT/S FRONTAL BOUNDARY LIFTS NORTHWARD WITH
SECONDARY LOW PRES DEVELOPING ON THE FRONT IN RESPONSE TO RRQ OF
THE UPPER JET STREAK. THIS YIELDS LIKELY POPS ACROSS CAPE COD AND
THE ISLANDS WITH CHANCE POPS ELSEWHERE FOR SCATTERED SHOWERS.
GREATEST RISK OF SHOWERS IS SOMEWHERE BETWEEN 4-8 PM. COULD BE
SOME HEAVIER SHOWERS ALONG SOUTH COAST AND OFFSHORE AS PWATS CLIMB
TO 2 INCHES /+2 STD FROM CLIMO/. HOWEVER INSTABILITY ALOFT AND AT
THE SURFACE IS LACKING SO HEAVIER SHOWERS AND THUNDER MAY BE WELL
OFFSHORE. SYSTEM IS VERY PROGRESSIVE SO NOT EXPECTING A SOAKING
RAIN. IN FACT SOME LOCATIONS MAY ONLY SEE A TRACE OF RAINFALL WITH
OTHER LOCATIONS SUCH AS WELL INLAND AND ALONG THE SOUTH COAST
PERHAPS A TENTH OR TWO.
TEMPS A FEW DEGS COOLER THAN TODAY GIVEN THE COOLER START ALONG WITH
INCREASING CLOUDS AND LIGHT ONSHORE WINDS.
SATURDAY NIGHT...
QUICK MOVING SYSTEM EXITS THE REGION BETWEEN 00Z WEST TO PERHAPS 03Z
CAPE COD. EXPECT DECREASING CLOUDS AND DRIER AIR TO OVERSPREAD THE
REGION. NORTHERLY WINDS WILL BECOME GUSTY LATE AT NIGHT AND TOWARD
SUNRISE SUNDAY WITH A FEW GUSTS UP TO 25 MPH POSSIBLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...
* LOW RISK OF PATCHY FROST SUN NIGHT ACROSS DISTANT INTERIOR
* A PERIOD OF SHOWERS LIKELY LATE MON NIGHT/TUE
* DRY WEATHER/SLIGHTLY BELOW NORMAL TEMPS NEXT WED-FRI
OVERVIEW...
OVERALL MODEL GUIDANCE IS IN AGREEMENT WITH A BROAD TROUGH OVER THE
EASTERN HALF OF THE CONTINENT AND A FULL-LATITUDE RIDGE OVER WESTERN
NORTH AMERICA. IN FACT APPEARS THAT THE NORTHERN BRANCH OF THE JET
STREAM REMAINS FAIRLY PROGRESSIVE ESP SINCE THE NAO TRENDING MORE
POSITIVE FOR THE FIRST HALF OF THIS FORECAST. THE FLOW DOES BEGIN TO
BECOME MORE AMPLIFIED TOWARDS THE END OF THE PERIOD AS A TROUGH DIGS
OVER THE EASTERN PACIFIC LEADING TO A RIDGE IN THE CENTRAL
CONUS....ABOUT WHEN THE NAO BECOMES MORE NEUTRAL. HOWEVER IT LOOKS
LIKE THE EASTERN CONUS WILL STILL REMAIN IN A TROUGH PATTERN THROUGH
THE WORK WEEK WITH A POSSIBLE CHANGE IN THE PATTERN BY NEXT WEEKEND.
ONLY MAJOR WEATHER MAKE TO WATCH FOR AT THE MOMENT IS THE SHORTWAVE
PASSING THROUGH MONDAY NIGHT/TUESDAY BRINGING SHOWERS TO THE REGION.
LOW CONFIDENCE ON EXACT TIMING BUT CONFIDENCE IS INCREASING THAT
PRECIP WILL OCCUR.
OTHERWISE HIGH PRESSURE WILL PREVAIL WITH TEMPS AT OR BELOW AVERAGE
FOR THIS TIME OF YEAR. IN FACT SUNDAY NIGHT AND MID TO LATE NEXT
WEEK MAY NEED TO WATCH FOR FROST HEADLINES.
DETAILS...
MONDAY...
A MODIFIED CANADIAN HIGH WILL BUILD INTO NEW ENGLAND DURING THIS
PORTION OF THE FORECAST...CRESTING OVER THE REGION ON MONDAY. LOWS
ON SUN NIGHT WILL BE QUITE CHILLY FOR SEPTEMBER. ALTHOUGH RECORD
COLD IS NOT EXPECTED...WE MAY STILL SEE SOME MIDDLE TO UPPER 30S
ACROSS PORTIONS OF SOUTHWEST NH/NORTHWEST MA...WHERE THIS IS A LOW
RISK FOR SOME PATCHY FROST IN THE TYPICALLY COOLEST OUTLYING
LOCATIONS. FOR MONDAY HIGHS...EVEN WITH FULL SUNSHINE TEMPS WILL
ONLY REACH INTO THE MID 60S TO LOWER 70S...SINCE THE SUN ANGLE IS
LOW. DRY WEATHER WILL PREVAIL.
MONDAY NIGHT INTO TUESDAY...
THE NEXT SHOT FOR ANY SHOWERS WILL BE LATE MONDAY NIGHT INTO
TUESDAY AS ANOTHER SHORTWAVE MOVES THROUGH THE FLOW. OVERALL
GUIDANCE HAS TRENDED TO BE ON THE WETTER SIDE SO CONFIDENCE IS
INCREASING THAT PRECIP WILL OCCUR. RIGHT NOW LOOKS AS IF DROUGHT
STRICKEN RI AND SE MASS HAVE THE BETTER SHOT FOR THE HIGHER QPF
AMOUNTS. ALTHOUGH THE EC DOES HAVE A QPF BULLS-EYE FOR THE
REGION...NOTICED THAT THE GFS HAS TICKED UP SO OVER 0.25 TO 0.5
INCHES IS NOT OUT OF THE QUESTION...ESPECIALLY SINCE PWAT VALUES
DO NOSE IN AT ABOUT 1.5 INCHES. INSTABILITY LOOKS FAIRLY
LIMITED...SO WILL NOT INCLUDE THUNDER IN THE FORECAST AT THIS
TIME. HIGHS SHOULD BE IN THE 60S TO AROUND 70.
END OF THE WORK WEEK...
HIGH PRESSURE FROM CANADA WILL SET UP OVER THE NORTHEAST ON WED
INTO FRIDAY. THE GFS BRING AN ARCTIC FRONT ACROSS THE REGION ON
WED WHILE THE EC HOLDS IT UP UNTIL THURSDAY NIGHT. EITHER WAY
GUIDANCE IS SHOWING 850 MB TEMPS DROPPING BELOW 0C. THIS WILL KEEP
TEMPS WELL BELOW AVERAGE...IN THE 60S RESULTING IN CRISP FALL LIKE
TEMPS. BECAUSE OF THE DIFFERENCE...WILL CONTINUE WITH A BLEND OF
PREV FORECAST AS WELL AS THE ENSEMBLES FOR NOW. EITHER WHICH WAY
WE MAY NEED TO BEGIN TO WATCH FOR THE RISK FOR SOME FROST IN
SOUTHWEST NH/NORTHWEST MA...WHERE WINDS CAN DECOUPLE.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERNIGHT...
MODERATE CONFIDENCE. MAIN CHALLENGE ARE A FEW PATCHES OF
STRATOCUMULUS CLOUDS IN 30-35 HUNDRED LAYER. RAP MODEL SEEMS TO
HAVE BEST HANDLE SO FAR ON THIS. LIGHT NORTH TO NORTHEAST WINDS
EXPECTED TO BECOME MORE FROM THE EAST TO NORTHEAST AFTER DAYBREAK.
SATURDAY...
MVFR CIGS EXPECTED TO DEVELOP FROM WEST TO EAST AND SOUTH TO NORTH
DURING THE AFTERNOON. SCATTERED SHOWERS MOST LIKELY AFTER 20Z WITH
SOME MOVING FROM WEST TO EAST AND A SECOND AREA SOUTHWEST TO
NORTHEAST TOWARD THE CAPE AND ISLANDS.
SAT NIGHT...
MVFR CIGS IN SCATTERED SHOWERS WITH PATCHES OF IFR CIGS POSSIBLE
SE COASTAL AREAS. CONDITIONS IMPROVING TO VFR BY 03Z WEST AND BY
06Z EAST. MODEST NNE WIND DEVELOPS 06Z- 12Z WITH GUSTS UP TO
20-25 KT POSSIBLE E COASTAL AREAS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. CIGS BKN030 POSSIBLE A
FEW HOURS ON EITHER SIDE OF SUNRISE...THEN PROBABLY A PERIOD OF
VFR MID TO LATE MORNING BEFORE CIGS LOWERING TO MVFR RANGE BY MID
OR LATE AFTERNOON. SCATTERED SHOWERS MAY LOWER VSBYS TO MVFR
THRESHOLDS FOR A TIME LATE AFTERNOON/EARLY EVENING. GREATEST RISK
OF SHOWERS 20Z SAT THRU 03Z SUN. CONDITIONS IMPROVING AFTER 03Z
SUN.
KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE. GREATEST RISK OF
SHOWERS 18Z SAT THRU 00Z SUNDAY WITH A PERIOD OR TWO OF MVFR CIGS
AND VSBYS POSSIBLE.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...HIGH CONFIDENCE.
MAINLY VFR CONDITIONS OVER THIS TIME...EXCEPT FOR A PERIOD OF MVFR-
IFR CONDITIONS LATE MON NIGHT/TUE IN A ROUND OF SHOWERS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
FORECAST CONFIDENCE IS MODERATE TO HIGH THROUGH SUNDAY.
OVERNIGHT...LIGHT EAST TO NORTHEAST WINDS...DRY WEATHER AND GOOD
VSBY.
SATURDAY...GENERALLY LIGHT EASTERLY WINDS. ONE AREA OF LOW PRES
TRACKS NE INTO NY STATE AND ANOTHER WEAK LOW FORMS OFF THE NJ
COAST. CHANCE OF SHOWERS LATE IN THE DAY WITH A LOW RISK OF
THUNDER WELL SOUTH OF NEW ENGLAND.
SAT NIGHT...WEAK LOW PRES MOVES NE ACROSS GEORGES BANK. A MODEST
NORTH WIND DEVELOPS WITH A CHANCE OF GUSTS TO NEAR 25 KT LATE.
SCATTERED SHOWERS DURING THE EVENING GIVES WAY TO DRY WEATHER AND
GOOD VSBY.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY....
MONDAY INTO TUE MORNING...MODERATE TO HIGH CONFIDENCE. HIGH
PRESSURE NEARBY WILL RESULT IN A WEAK PRESSURE GRADIENT KEEPING
WINDS/SEAS BELOW SCA THRESHOLDS.
TUESDAY AFTERNOON INTO WEDNESDAY...MODERATE CONFIDENCE. MAY SEE
SOME MARGINAL SCA WINDS/SEAS ACROSS THE OUTER-WATERS BEHIND A COLD
FRONT/LOW PRESSURE SYSTEM IN THE COOL AIR ADVECTION PATTERN.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NOCERA/DUNTEN
NEAR TERM...FRANK/NOCERA/THOMPSON
SHORT TERM...NOCERA
LONG TERM...DUNTEN
AVIATION...NOCERA/DUNTEN/THOMPSON
MARINE...NOCERA/DUNTEN/THOMPSON
AREA FORECAST DISCUSSION
NWS TAUNTON MA
158 AM EDT SAT SEP 13 2014
.SYNOPSIS...
HIGH PRESSURE DOMINATES OVERNIGHT. A QUICK MOVING WEATHER SYSTEM
WILL BRING SCATTERED SHOWERS TO THE AREA LATE SATURDAY AFTERNOON
AND EARLY EVENING. HIGH PRESSURE BRINGS DRY WEATHER WITH SLIGHTLY
BELOW NORMAL TEMPERATURES SUNDAY INTO MONDAY. THE NEXT COLD FRONT
WILL LIKELY BRING A PERIOD OF SHOWERS LATE MONDAY NIGHT INTO
TUESDAY. MAINLY DRY WEATHER EXPECTED NEXT WEDNESDAY THROUGH FRIDAY
WITH SLIGHTLY BELOW NORMAL TEMPERATURES CONTINUING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
130 AM UPDATE...
ADJUSTED SKY COVER GRIDS BASED ON LATEST OBSERVATIONS AND
SATELLITE PICTURES. RAP SEEMS TO HAVE BEST HANDLE ON PATCHES OF
STRATOCUMULUS. ADJUSTED TEMPERATURES STILL A LITTLE COOLER IN SE
ZONES BASED ON LATEST OBSERVED TRENDS.
1015 PM UPDATE...
QUIET NIGHT WITH LITTLE CHANGE NEEDED IN FORECAST. DID LOWER
HOURLY AND MIN TEMPS FOR PORTIONS OF SE MA AND MARTHAS VINEYARD TO
ACCOUNT FOR CURRENT TRENDS AND CLIMATOLOGY. KEPT POP NEAR ZERO
PERCENT THROUGH 8 AM AND JUST MADE A FEW TWEAKS WITH THE SKY COVER
TO BE CONSISTENT WITH CURRENT TRENDS.
630 PM UPDATE...
STRATO-CUMULUS CLOUDS HAVE DISSIPATED EARLY THIS EVENING ACROSS THE
CAPE AND ISLANDS. OTHERWISE...MAINLY CLEAR SKIES WERE IN PLACE
EARLY THIS EVENING OTHER THAN A TOUCH OF HIGH CLOUDINESS.
IDEAL SEP WEATHER ACROSS THE REGION THROUGH THE EVENING WITH MAINLY
CLEAR SKIES...COMFORTABLE TEMPS AND LIGHT WINDS. AFTER
SUNSET...TEMPS WILL FALL FAIRLY QUICKLY GIVEN DRY
ATMOSPHERE...CLEAR SKIES AND LIGHT WINDS. MANY LOCATIONS WILL DIP
INTO THE MU40S TONIGHT INCLUDING PLACES SUCH AS MARTHAS VINEYARD...
NORWOOD AND OTHER INTERIOR EASTERN MA LOCATIONS. ALSO WESTERN MA AND
SOUTHWEST NH SHOULD FALL INTO THE MU40S. ELSEWHERE MINS WILL BE IN
THE LOW TO MID 50S.
TRICKY PART TO THE FORECAST WILL BE IF SOME LOW CLOUDS ARE ABLE TO
DEVELOP NEAR THE COAST TOWARD DAYBREAK. THESE CLOUDS MAY REAPPEAR
TOWARD SUNRISE GIVEN BLYR COOLING OVERNIGHT. THUS COULD SEE SKIES
BECOME PARTLY TO MOSTLY CLOUDY TOWARD DAYBREAK OVER EASTERN MA AND
POSSIBLY INTO RI...BUT CONFIDENCE IS LOW.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
SATURDAY...
DRY TO START THE DAY BUT QUICK MOVING NORTHERN STREAM SHORT WAVE
TROUGH APPROACHES FROM THE WEST. TWO AREAS OF SHOWERS WILL TRACK
ACROSS THE NORTHEAST. FIRST BATCH WILL BE OVER NY STATE AND
NORTHERN NEW ENGLAND WITH PARENT LOW AND ACCOMPANYING LOW TO MID
LEVEL JET. A SECOND AREA OF SHOWERS WILL TRACK SOUTH OF NEW
ENGLAND AS LAST NIGHT/S FRONTAL BOUNDARY LIFTS NORTHWARD WITH
SECONDARY LOW PRES DEVELOPING ON THE FRONT IN RESPONSE TO RRQ OF
THE UPPER JET STREAK. THIS YIELDS LIKELY POPS ACROSS CAPE COD AND
THE ISLANDS WITH CHANCE POPS ELSEWHERE FOR SCATTERED SHOWERS.
GREATEST RISK OF SHOWERS IS SOMEWHERE BETWEEN 4-8 PM. COULD BE
SOME HEAVIER SHOWERS ALONG SOUTH COAST AND OFFSHORE AS PWATS CLIMB
TO 2 INCHES /+2 STD FROM CLIMO/. HOWEVER INSTABILITY ALOFT AND AT
THE SURFACE IS LACKING SO HEAVIER SHOWERS AND THUNDER MAY BE WELL
OFFSHORE. SYSTEM IS VERY PROGRESSIVE SO NOT EXPECTING A SOAKING
RAIN. IN FACT SOME LOCATIONS MAY ONLY SEE A TRACE OF RAINFALL WITH
OTHER LOCATIONS SUCH AS WELL INLAND AND ALONG THE SOUTH COAST
PERHAPS A TENTH OR TWO.
TEMPS A FEW DEGS COOLER THAN TODAY GIVEN THE COOLER START ALONG WITH
INCREASING CLOUDS AND LIGHT ONSHORE WINDS.
SATURDAY NIGHT...
QUICK MOVING SYSTEM EXITS THE REGION BETWEEN 00Z WEST TO PERHAPS 03Z
CAPE COD. EXPECT DECREASING CLOUDS AND DRIER AIR TO OVERSPREAD THE
REGION. NORTHERLY WINDS WILL BECOME GUSTY LATE AT NIGHT AND TOWARD
SUNRISE SUNDAY WITH A FEW GUSTS UP TO 25 MPH POSSIBLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...
* DRY WITH SLIGHTLY BELOW NORMAL TEMPS SUN/MON
* LOW RISK OF PATCHY FROST SUN NIGHT ACROSS DISTANT INTERIOR
* A PERIOD OF SHOWERS LIKELY LATE MON NIGHT/TUE
* DRY WEATHER/SLIGHTLY BELOW NORMAL TEMPS NEXT WED-FRI
DETAILS...
SUNDAY AND MONDAY...
LARGE HIGH PRESSURE WILL BE ANCHORED OVER SOUTHERN NEW ENGLAND SUN
AND MON. THIS WILL RESULT IN DRY WEATHER WITH SLIGHTLY BELOW NORMAL
HIGH TEMPS. HIGHS SUN AND MON WILL BE IN THE 60S...TO LOWER 70S.
LOWS SUN NIGHT WILL BE QUITE CHILLY FOR MID SEPTEMBER. MAY SEE SOME
MIDDLE TO UPPER 30S ACROSS PORTIONS OF SOUTHWEST NH/NORTHWEST MA...
WHERE THIS IS A LOW RISK FOR SOME PATCHY FROST IN THE TYPICALLY
COOLEST OUTLYING LOCATIONS. MOST OTHER AREAS WILL SEE LOWS IN THE
40S.
MONDAY NIGHT AND TUESDAY...
A POTENT SHORTWAVE/COLD FRONT WILL BE APPROACHING SOUTHERN NEW
ENGLAND LATE MON NIGHT INTO TUE. THIS SHOULD RESULT IN A PERIOD OF
RAIN SHOWERS...BUT EXACT TIMING IS UNCERTAIN AT THIS POINT. ITS
POSSIBLE WE COULD EVEN SEE A PERIOD OF HEAVY RAIN IF THE MORE
AMPLIFIED ECMWF MODEL IS CORRECT...BUT GFS/GGEM ARE A TAMER WITH THE
SHORTWAVE SO THAT IS UNCERTAIN. INSTABILITY LOOKS FAIRLY
LIMITED...SO WILL NOT INCLUDE THUNDER IN THE FORECAST AT THIS TIME.
HIGHS SHOULD BE IN THE 60S TO AROUND 70.
WEDNESDAY THROUGH FRIDAY...
HIGH PRESSURE BUILDS IN BEHIND THE COLD FRONT WED INTO FRI. THIS
SHOULD RESULT IN MAINLY DRY WEATHER WITH SLIGHTLY BELOW NORMAL TEMPS
FOR THE END OF THE WORK WEEK. WE MAY HAVE TO DEAL WITH THE RISK
FOR SOME FROST IN SOUTHWEST NH/NORTHWEST MA...WHERE WINDS CAN
DECOUPLE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERNIGHT...
MODERATE CONFIDENCE. MAIN CHALLENGE ARE A FEW PATCHES OF
STRATOCUMULUS CLOUDS IN 30-35 HUNDRED LAYER. RAP MODEL SEEMS TO
HAVE BEST HANDLE SO FAR ON THIS. LIGHT NORTH TO NORTHEAST WINDS
EXPECTED TO BECOME MORE FROM THE EAST TO NORTHEAST AFTER DAYBREAK.
SATURDAY...
MVFR CIGS EXPECTED TO DEVELOP FROM WEST TO EAST AND SOUTH TO NORTH
DURING THE AFTERNOON. SCATTERED SHOWERS MOST LIKELY AFTER 20Z WITH
SOME MOVING FROM WEST TO EAST AND A SECOND AREA SOUTHWEST TO
NORTHEAST TOWARD THE CAPE AND ISLANDS.
SAT NIGHT...
MVFR CIGS IN SCATTERED SHOWERS WITH PATCHES OF IFR CIGS POSSIBLE
SE COASTAL AREAS. CONDITIONS IMPROVING TO VFR BY 03Z WEST AND BY
06Z EAST. MODEST NNE WIND DEVELOPS 06Z- 12Z WITH GUSTS UP TO
20-25 KT POSSIBLE E COASTAL AREAS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. CIGS BKN030 POSSIBLE A
FEW HOURS ON EITHER SIDE OF SUNRISE...THEN PROBABLY A PERIOD OF
VFR MID TO LATE MORNING BEFORE CIGS LOWERING TO MVFR RANGE BY MID
OR LATE AFTERNOON. SCATTERED SHOWERS MAY LOWER VSBYS TO MVFR
THRESHOLDS FOR A TIME LATE AFTERNOON/EARLY EVENING. GREATEST RISK
OF SHOWERS 20Z SAT THRU 03Z SUN. CONDITIONS IMPROVING AFTER 03Z
SUN.
KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE. GREATEST RISK OF
SHOWERS 18Z SAT THRU 00Z SUNDAY WITH A PERIOD OR TWO OF MVFR CIGS
AND VSBYS POSSIBLE.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE.
MAINLY VFR CONDITIONS OVER THIS TIME...EXCEPT FOR A PERIOD OF
MVFR-IFR CONDITIONS LATE MON NIGHT/TUE IN A ROUND OF SHOWERS AND
PERHAPS SOME LOW CLOUDS/FOG PATCHES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
FORECAST CONFIDENCE IS MODERATE TO HIGH THROUGH SUNDAY.
OVERNIGHT...LIGHT EAST TO NORTHEAST WINDS...DRY WEATHER AND GOOD
VSBY.
SATURDAY...GENERALLY LIGHT EASTERLY WINDS. ONE AREA OF LOW PRES
TRACKS NE INTO NY STATE AND ANOTHER WEAK LOW FORMS OFF THE NJ
COAST. CHANCE OF SHOWERS LATE IN THE DAY WITH A LOW RISK OF
THUNDER WELL SOUTH OF NEW ENGLAND.
SAT NIGHT...WEAK LOW PRES MOVES NE ACROSS GEORGES BANK. A MODEST
NORTH WIND DEVELOPS WITH A CHANCE OF GUSTS TO NEAR 25 KT LATE.
SCATTERED SHOWERS DURING THE EVENING GIVES WAY TO DRY WEATHER AND
GOOD VSBY.
OUTLOOK...SUNDAY THROUGH WEDNESDAY....
SUNDAY...MODERATE TO HIGH CONFIDENCE. MAY HAVE SOME MARGINAL SCA
NORTHERLY WIND GUSTS/SEAS ACROSS THE EASTERN WATERS SUN MORNING IN
THE COOL ADVECTION PATTERN. WINDS/SEAS SHOULD DIMINISH SUN
AFTERNOON AS PRESSURE GRADIENT WEAKENS.
MONDAY INTO TUE MORNING...MODERATE TO HIGH CONFIDENCE. HIGH
PRESSURE NEARBY WILL RESULT IN A WEAK PRESSURE GRADIENT KEEPING
WINDS/SEAS BELOW SCA THRESHOLDS.
TUESDAY AFTERNOON INTO WEDNESDAY...MODERATE CONFIDENCE. MAY SEE
SOME MARGINAL SCA WINDS/SEAS ACROSS THE OUTER-WATERS BEHIND A COLD
FRONT/LOW PRESSURE SYSTEM IN THE COOL AIR ADVECTION PATTERN.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/NOCERA
NEAR TERM...FRANK/NOCERA/THOMPSON
SHORT TERM...NOCERA
LONG TERM...FRANK
AVIATION...FRANK/NOCERA/THOMPSON
MARINE...FRANK/NOCERA/THOMPSON
AREA FORECAST DISCUSSION
NWS MIAMI FL
348 PM EDT SAT SEP 13 2014
.DISCUSSION...
THE LATEST CONSENSUS OF THE MODEL GUIDANCE...BOTH THE GLOBAL
MODELS AND THE LATEST HRRR RUN...INDICATE THE POTENTIAL FOR
SHOWERS AND THUNDERSTORMS TO FORM ACROSS THE FLORIDA STRAITS THIS
EVENING AND AFFECT THE SOUTHERN PORTIONS OF SOUTH FLORIDA AND
ADJACENT WATERS LATER THIS EVENING AND POSSIBLY CONTINUING INTO
THE EARLY MORNING HOURS ON SUNDAY. RECENT SATELLITE IMAGERY AND
RADAR RETURNS INDICATE THIS PROCESS IS ALREADY UNDERWAY WITH BANDS
OF SHOWERS AND THUNDERSTORMS OBSERVED ACROSS THE FLORIDA STRAITS.
OVER NIGHT AND INTO SUNDAY...A BROAD AREA OF SURFACE LOW PRESSURE
ACROSS THE EASTERN GULF WILL CONTINUE TO TRACK WESTWARD INTO THE
CENTRAL GULF. THE MORE RECENT GUIDANCE HAS CONSISTENTLY BEEN
INDICATING THAT DEEP TROPICAL MOISTURE WILL CONTINUE TO LINGER
ACROSS SOUTH FLORIDA AND ADJACENT WATERS WITH LOW LEVEL MASS AND
MOISTURE CONVERGENCE CONTINUING ACROSS THE REGION INTO SUNDAY
MORNING. IN ADDITION THE UPPER LEVEL WINDS COULD BE FAVORABLE FOR
SPEED DIVERGENCE DURING THE AFTERNOON HOURS. DAY TIME HEATING AND
WITH THE LINGERING DEEP MOISTURE WILL ALLOW FOR AFTERNOON
CONVECTION ON SUNDAY WITH THE GREATEST COVERAGE OF SHOWERS AND
THUNDERSTORMS EXPECTED INLAND AND WEST.
FOR MONDAY AND TUESDAY...SOME RELATIVELY DRIER AIR IS FORECAST TO
ENTER THE REGION ALTHOUGH THE GUIDANCE CONSENSUS INDICATES THAT
LINGERING MOISTURE COULD BE SUFFICIENT FOR AFTERNOON SHOWERS AND
THUNDERSTORMS...MAINLY OVER THE THE PENINSULA. THE EXTENDED
GUIDANCE CONTINUES TO SUGGEST THAT LATE NEXT WEEK DEEP MOISTURE
COULD EXTEND FROM THE YUCATAN PENINSULA NORTHEASTWARD ACROSS SOUTH
FLORIDA AND INTO THE WESTERN ATLANTIC WITH A LARGE AMPLITUDE UPPER
LEVEL TROUGH DEEPENING INTO THE CENTRAL GULF. THIS PATTERN IS
FORECAST TO LINGER INTO NEXT WEEKEND WITH THE POTENTIAL FOR
WIDESPREAD LOCAL CONVECTION.
&&
.MARINE...
MAINLY EASTERLY WINDS ARE FORECAST TO BE IN THE 10 TO 15 KNOT
RANGE ACROSS THE REGIONAL WATERS TONIGHT THROUGH SUNDAY THEN
SLOWLY DECREASING INTO EARLY NEXT WEEK WHILE REMAINING EASTERLY.
REGIONAL SEAS ARE FORECAST TO BE MAINLY AROUND 2 FEET OR LESS THE
REMAINDER OF THE WEEKEND INTO EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 86 76 / 50 40 60 20
FORT LAUDERDALE 87 77 88 79 / 50 50 50 20
MIAMI 87 77 87 78 / 50 50 50 20
NAPLES 89 75 87 76 / 70 40 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...23/SK
LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
128 PM EDT SAT SEP 13 2014
.AVIATION...
SHOWERS WITH ISOLATED THUNDER ARE NOW DEVELOPING NEAR THE EAST
COAST TERMINALS, WITH ADDITIONAL DEVELOPMENT THROUGH THE ATLANTIC
WATERS. QUESTIONABLE IF EAST COAST TERMINALS WILL FALL BEHIND THE
SEA BREEZE, WITH ONLY SHOWERS THE REST OF TODAY, OR WILL CONTINUE
TO SEE ADDITIONAL DEVELOPMENT OF THUNDERSTORMS WITH A WEAK UPPER
DISTURBANCE CURRENTLY JUST WEST OF THE BAHAMAS. ALTHOUGH VCTS IS
IN THE TAFS, IT MAY BE REMOVED LATER IF STORMS DON`T FIRE.
THEREFORE, DID NOT INCLUDE ANY TEMPO GROUPS ATTM. FEELING MORE
CONFIDENT ABOUT DEVELOPMENT AT APF, AS SEA BREEZE/STORMS MOVE
ACROSS THE PENINSULA. LIKE LAST NIGHT, ACTUALLY EXPECTING MORE
COVERAGE OF SHOWERS AND STORMS OVERNIGHT AS EASTERLY FLOW
CONTINUES. ANOTHER STRONGER VORT MAX NEAR NASSAU WILL ARRIVE JUST
EAST OF BISCAYNE BAY TONIGHT. THE HRRR/NAM/GFS ALL PINPOINTING
THIS DISTURBANCE FOR HEAVY RAINFALL/NUMEROUS STORMS FROM 0Z-6Z,
WHICH COULD VERY WELL SURVIVE INTO KTMB/KMIA/KOPF TONIGHT.
THEREFORE, LEFT VCTS IN THROUGH PART OF THE EVENING, WITH THE
POTENTIAL FOR SOME MVFR/IFR IF GUIDANCE IS CORRECT. FARTHER NORTH
ALONG THE EAST COAST, VCSH WAS USED BUT AGAIN POSSIBLE THAT NUMEROUS
SHOWERS AND STORMS AFFECT THOSE TAF SITES TOO.
&&
.PREV DISCUSSION... /ISSUED 1105 AM EDT SAT SEP 13 2014/
UPDATE...
WHILE SHOWER AND THUNDERSTORM ACTIVITY HAS SUBSIDED ACROSS THE
REGION THIS MORNING...THE POTENTIAL FOR ACTIVE CONVECTION
CONTINUES. RECENT VISIBLE SATELLITE IMAGERY INDICATES ACTIVE
CONVECTION IN THE EASTERN GULF ASSOCIATED WITH THE AREA OF LOW
PRESSURE OFF THE SOUTHWEST FLORIDA COAST AND ADDITIONAL CONVECTION
IN THE CENTRAL BAHAMAS ISLANDS. THE 12Z SOUNDING INDICATED A PWAT
AROUND 1.9 INCHES AND INDICATED A SIGNIFICANT COOLING TREND IN THE
MID LEVELS AS WELL. GIVEN THE GENERAL CLEARING TREND OVER THE
PENINSULA THIS MORNING...DAY TIME HEATING IS EXPECTED TO DRIVE
CONVECTION THIS AFTERNOON AND EARLY EVENING WITH THE GREATEST
COVERAGE OF SHOWERS AND THUNDERSTORMS STILL EXPECTED IN THE
WESTERN INTERIOR AND WESTERN PORTIONS OF THE PENINSULA...INCLUDING
THE NAPLES METRO AREAS.
60
PREV DISCUSSION... /ISSUED 830 AM EDT SAT SEP 13 2014/
AVIATION...
RATHER DISORGANIZED UPPER LOW, WITH A FEW DISTURBANCES TRAILING
TO THE EAST, WILL BE THE IMPETUS FOR STORMS TODAY. LARGE MASS OF
MID LEVEL DRY AIR PER WATER VAPOR LOOP, MAY STAY NORTH OF THE
REGION TODAY, UNLIKE YESTERDAY. PERHAPS SOME OF THIS DRY AIR WILL
WRAP INTO THE CIRCULATION OF THE UPPER LOW, BUT THAT MAY NOT MEAN
MUCH SINCE THE LOW IS ALREADY OFF THE SW FL COAST. LAMP GUIDANCE
INDICATES THAT A SEA BREEZE WILL DEVELOP ALONG THE EAST COAST,
PERHAPS KEEPING MOST CONVECTION INLAND AND WEST COAST. THIS IS UP
AGAINST THE HRRR WHICH IS AGGRESSIVE PAINTING STORMS ALONG THE
BEACHES AND MOST TERMINALS BY MID AFTERNOON. THE TAFS CAN BE FINE
TUNED ONCE RAOB DATA ARRIVES, BUT WILL INSERT VCTS FOR NOW, AS
PREVIOUS DISCUSSION MENTIONED VCTS FOR ALL TAFS, BUT TAFS ONLY
CONTAINED VCSH. PERHAPS SOME OF THE SHOWERS OFFSHORE OF PBI ARRIVE
LATER THIS MORNING. PERSISTENCE OF CLOUD COVER ALONG THE EAST
COAST WILL ALSO GO A LONG WAY IN DETERMINING STORM EVOLUTION
TODAY. CONFIDENCE IS BELOW AVERAGE.
PREV DISCUSSION... /ISSUED 431 AM EDT SAT SEP 13 2014/
SHORT TERM...(TODAY-MONDAY)
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED AN UPPER LOW CENTERED OVER
SOUTH FLORIDA SLOWLY TRACKING WESTWARD AND A RIDGE AXIS ORIENTED
FROM EAST TO WEST ACROSS THE NORTHERN GULF COAST STATES. PLENTY OF
DEEP LAYER MOISTURE EAST OF THIS UPPER LOW COMBINED WITH UPPER-LEVEL
DIVERGENCE WILL CONTINUE TO SUPPORT WIDESPREAD RAINFALL TODAY
ESPECIALLY ALONG THE SOUTHEAST COAST AND ACROSS THE ATLANTIC
WATERS THROUGH THE MORNING HOURS. THE LATEST HRRR MODEL RUN APPEARS
TO HAVE INITIALIZED WELL WITH THE CURRENT RADAR TRENDS AND GENERALLY
INDICATES THIS MORNING ACTIVITY CONTINUING ACROSS THE EASTERN
AREAS INCLUDING PALM BEACH, BROWARD AND MIAMI-DADE BEFORE SHIFTING
INLAND AND TOWARD THE GULF COAST THROUGH THE MID TO LATE
AFTERNOON/EARLY EVENING PERIOD. THIS SOLUTION MAKES SENSE WITH THE
UPPER LOW SHIFTING WESTWARD AND LIGHT TO MODERATE SOUTHEAST LOW-
LEVEL FLOW CONTINUING. THIS PATTERN WILL KEEP THE POTENTIAL FOR
LOCALIZED FLOODING UP THROUGH THIS EVENING...ESPECIALLY OVER THE
AREAS THAT ARE ALREADY SATURATED FROM EARLIER RAINFALL (AREAS HAVE
RECEIVED 2-4 INCHES WITH HIGHER AMOUNTS UP TO 7" JUST INLAND OF
BOCA RATON OVER THE PAST 24-36 HRS). MODEL SOUNDINGS SUPPORT THE
ACTIVITY TAPERING OFF OVER THE FAR SOUTHEASTERN AREAS OR TOWARD
MIAMI THROUGH THE MORNING AND AFTERNOON HOURS WITH MAINLY
SATURATED PROFILES ABOVE A SLIGHTLY DRIER LAYER FROM THE SURFACE
TO 700MB. AS A RESULT...MAXIMUM TEMPERATURES HAVE BEEN SLIGHTLY
UNDERCUT BY A FEW DEGREES COMPARED TO GUIDANCE...MAINLY DUE TO
PLENTY OF CLOUD COVERAGE ANTICIPATED. IF THIS COVERAGE BEGINS TO
BREAK THROUGH THE DAY...TEMPERATURES WILL NEED TO BE ADJUSTED
ACCORDINGLY. THE MOIST TREND WITH SOUTHEAST FLOW WILL PERSIST
THROUGH SUNDAY BEFORE SOME DRIER AIR MOVES IN FROM THE WEST AND
THE RIDGE BUILDS BACK ACROSS THE REGION INTO THE UPCOMING WEEK.
/85
LONG TERM (TUESDAY-FRIDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT ON THE
LARGE SCALE AND GENERALLY INDICATES FALLING UPPER HEIGHTS IN
RESPONSE TO A DEEPENING UPPER TROUGH ACROSS THE REGION. A FRONTAL
BOUNDARY IS PROJECTED TO SHIFT SOUTHWARD AND STALL NORTH OF THE AREA
THROUGH THE SECOND HALF OF THE WEEK. THE ECMWF SEEMS TO BE THE MORE
BULLISH SOLUTION AND SHOWS THE MOISTURE AXIS ASSOCIATED WITH THIS
BOUNDARY PROGRESSING FARTHER SOUTH THAN THE GFS/GFS ENSEMBLE MEAN
WITH SSW LOW-LEVEL FLOW SETTING UP OVER THE AREA BY THURSDAY. THE
COMBINATION OF THE FRONT AND FALLING UPPER HEIGHTS ALONG WITH SSW
LOW-LEVEL FLOW WOULD FAVOR MUCH OF THE RAINFALL SETTING UP OVER THE
EAST COAST/METRO AREAS BY THURSDAY.
/85
AVIATION...
A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS
WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL
VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE
SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE
BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF
SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS AND
GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW PRESSURE
OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL CONTINUE TO
MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE REGION
THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT CONVECTION MAY
LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST METRO AREAS DURING
THE DAY. HOWEVER...DEEP MOISTURE IN THE SOUTHEAST LOW LEVEL FLOW
WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF SITES. AT KAPF...SHOWER
AND STORM DEVELOPMENT IS FORECAST TO BECOME MORE LIKELY AS THE DAY
PROGRESSES...AS THE INFLUENCE OF THE UPPER LOW INCREASES. LIGHT
WINDS WILL CONTINUE THROUGH THE OVERNIGHT HOURS OUTSIDE OF SHOWERS
AND STORMS...AND THEN BECOME SOUTHEAST AROUND 10 KNOTS DURING THE
DAY.
/84
MARINE...
AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE
MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO
MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY
HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL
BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING
WEEK WITH SOUTHEAST WINDS CONTINUING.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 87 76 87 / 30 50 30 50
FORT LAUDERDALE 77 87 79 88 / 40 60 20 50
MIAMI 77 87 78 88 / 40 60 20 50
NAPLES 75 89 76 89 / 30 60 20 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...60/BD
LONG TERM....85/AG
AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS MIAMI FL
1105 AM EDT SAT SEP 13 2014
.UPDATE...
WHILE SHOWER AND THUNDERSTORM ACTIVITY HAS SUBSIDED ACROSS THE
REGION THIS MORNING...THE POTENTIAL FOR ACTIVE CONVECTION
CONTINUES. RECENT VISIBLE SATELLITE IMAGERY INDICATES ACTIVE
CONVECTION IN THE EASTERN GULF ASSOCIATED WITH THE AREA OF LOW
PRESSURE OFF THE SOUTHWEST FLORIDA COAST AND ADDITIONAL CONVECTION
IN THE CENTRAL BAHAMAS ISLANDS. THE 12Z SOUNDING INDICATED A PWAT
AROUND 1.9 INCHES AND INDICATED A SIGNIFICANT COOLING TREND IN THE
MID LEVELS AS WELL. GIVEN THE GENERAL CLEARING TREND OVER THE
PENINSULA THIS MORNING...DAY TIME HEATING IS EXPECTED TO DRIVE
CONVECTION THIS AFTERNOON AND EARLY EVENING WITH THE GREATEST
COVERAGE OF SHOWERS AND THUNDERSTORMS STILL EXPECTED IN THE
WESTERN INTERIOR AND WESTERN PORTIONS OF THE PENINSULA...INCLUDING
THE NAPLES METRO AREAS.
60
&&
.PREV DISCUSSION... /ISSUED 830 AM EDT SAT SEP 13 2014/
AVIATION...
RATHER DISORGANIZED UPPER LOW, WITH A FEW DISTURBANCES TRAILING
TO THE EAST, WILL BE THE IMPETUS FOR STORMS TODAY. LARGE MASS OF
MID LEVEL DRY AIR PER WATER VAPOR LOOP, MAY STAY NORTH OF THE
REGION TODAY, UNLIKE YESTERDAY. PERHAPS SOME OF THIS DRY AIR WILL
WRAP INTO THE CIRCULATION OF THE UPPER LOW, BUT THAT MAY NOT MEAN
MUCH SINCE THE LOW IS ALREADY OFF THE SW FL COAST. LAMP GUIDANCE
INDICATES THAT A SEA BREEZE WILL DEVELOP ALONG THE EAST COAST,
PERHAPS KEEPING MOST CONVECTION INLAND AND WEST COAST. THIS IS UP
AGAINST THE HRRR WHICH IS AGGRESSIVE PAINTING STORMS ALONG THE
BEACHES AND MOST TERMINALS BY MID AFTERNOON. THE TAFS CAN BE FINE
TUNED ONCE RAOB DATA ARRIVES, BUT WILL INSERT VCTS FOR NOW, AS
PREVIOUS DISCUSSION MENTIONED VCTS FOR ALL TAFS, BUT TAFS ONLY
CONTAINED VCSH. PERHAPS SOME OF THE SHOWERS OFFSHORE OF PBI ARRIVE
LATER THIS MORNING. PERSISTENCE OF CLOUD COVER ALONG THE EAST
COAST WILL ALSO GO A LONG WAY IN DETERMINING STORM EVOLUTION
TODAY. CONFIDENCE IS BELOW AVERAGE.
PREV DISCUSSION... /ISSUED 431 AM EDT SAT SEP 13 2014/
SHORT TERM...(TODAY-MONDAY)
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED AN UPPER LOW CENTERED OVER
SOUTH FLORIDA SLOWLY TRACKING WESTWARD AND A RIDGE AXIS ORIENTED
FROM EAST TO WEST ACROSS THE NORTHERN GULF COAST STATES. PLENTY OF
DEEP LAYER MOISTURE EAST OF THIS UPPER LOW COMBINED WITH UPPER-LEVEL
DIVERGENCE WILL CONTINUE TO SUPPORT WIDESPREAD RAINFALL TODAY
.ESPECIALLY ALONG THE SOUTHEAST COAST AND ACROSS THE ATLANTIC
WATERS THROUGH THE MORNING HOURS. THE LATEST HRRR MODEL RUN APPEARS
TO HAVE INITIALIZED WELL WITH THE CURRENT RADAR TRENDS AND GENERALLY
INDICATES THIS MORNING ACTIVITY CONTINUING ACROSS THE EASTERN
AREAS INCLUDING PALM BEACH, BROWARD AND MIAMI-DADE BEFORE SHIFTING
INLAND AND TOWARD THE GULF COAST THROUGH THE MID TO LATE
AFTERNOON/EARLY EVENING PERIOD. THIS SOLUTION MAKES SENSE WITH THE
UPPER LOW SHIFTING WESTWARD AND LIGHT TO MODERATE SOUTHEAST LOW-
LEVEL FLOW CONTINUING. THIS PATTERN WILL KEEP THE POTENTIAL FOR
LOCALIZED FLOODING UP THROUGH THIS EVENING...ESPECIALLY OVER THE
AREAS THAT ARE ALREADY SATURATED FROM EARLIER RAINFALL (AREAS HAVE
RECEIVED 2-4 INCHES WITH HIGHER AMOUNTS UP TO 7" JUST INLAND OF
BOCA RATON OVER THE PAST 24-36 HRS). MODEL SOUNDINGS SUPPORT THE
ACTIVITY TAPERING OFF OVER THE FAR SOUTHEASTERN AREAS OR TOWARD
MIAMI THROUGH THE MORNING AND AFTERNOON HOURS WITH MAINLY
SATURATED PROFILES ABOVE A SLIGHTLY DRIER LAYER FROM THE SURFACE
TO 700MB. AS A RESULT...MAXIMUM TEMPERATURES HAVE BEEN SLIGHTLY
UNDERCUT BY A FEW DEGREES COMPARED TO GUIDANCE...MAINLY DUE TO
PLENTY OF CLOUD COVERAGE ANTICIPATED. IF THIS COVERAGE BEGINS TO
BREAK THROUGH THE DAY...TEMPERATURES WILL NEED TO BE ADJUSTED
ACCORDINGLY. THE MOIST TREND WITH SOUTHEAST FLOW WILL PERSIST
THROUGH SUNDAY BEFORE SOME DRIER AIR MOVES IN FROM THE WEST AND
THE RIDGE BUILDS BACK ACROSS THE REGION INTO THE UPCOMING WEEK.
/85
LONG TERM (TUESDAY-FRIDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT ON THE
LARGE SCALE AND GENERALLY INDICATES FALLING UPPER HEIGHTS IN
RESPONSE TO A DEEPENING UPPER TROUGH ACROSS THE REGION. A FRONTAL
BOUNDARY IS PROJECTED TO SHIFT SOUTHWARD AND STALL NORTH OF THE AREA
THROUGH THE SECOND HALF OF THE WEEK. THE ECMWF SEEMS TO BE THE MORE
BULLISH SOLUTION AND SHOWS THE MOISTURE AXIS ASSOCIATED WITH THIS
BOUNDARY PROGRESSING FARTHER SOUTH THAN THE GFS/GFS ENSEMBLE MEAN
WITH SSW LOW-LEVEL FLOW SETTING UP OVER THE AREA BY THURSDAY. THE
COMBINATION OF THE FRONT AND FALLING UPPER HEIGHTS ALONG WITH SSW
LOW-LEVEL FLOW WOULD FAVOR MUCH OF THE RAINFALL SETTING UP OVER THE
EAST COAST/METRO AREAS BY THURSDAY.
/85
AVIATION...
A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS
WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL
VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE
SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE
BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF
SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS AND
GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW PRESSURE
OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL CONTINUE TO
MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE REGION
THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT CONVECTION MAY
LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST METRO AREAS DURING
THE DAY. HOWEVER...DEEP MOISTURE IN THE SOUTHEAST LOW LEVEL FLOW
WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF SITES. AT KAPF...SHOWER
AND STORM DEVELOPMENT IS FORECAST TO BECOME MORE LIKELY AS THE DAY
PROGRESSES...AS THE INFLUENCE OF THE UPPER LOW INCREASES. LIGHT
WINDS WILL CONTINUE THROUGH THE OVERNIGHT HOURS OUTSIDE OF SHOWERS
AND STORMS...AND THEN BECOME SOUTHEAST AROUND 10 KNOTS DURING THE
DAY.
/84
MARINE...
AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE
MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO
MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY
HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL
BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING
WEEK WITH SOUTHEAST WINDS CONTINUING.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 87 76 / 40 30 50 30
FORT LAUDERDALE 87 77 87 79 / 40 40 60 20
MIAMI 85 77 87 78 / 40 40 60 20
NAPLES 87 75 89 76 / 70 30 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...21/KM
LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1030 AM EDT Sat Sep 13 2014
.Near Term [Rest of Today]...
The previous forecast remains largely on track, so only minor
tweaks were made. The leading edge of an expansive stratus deck,
roughly marking the location of a quasi-stationary front, extended
from near Mobile to near Atlanta this morning. When combined with
14Z objective MSAS analysis of MSLP and observed winds, this
places the front very close to the northwest corner of our
forecast area. The environment along and immediately southeast of
the front is characterized by mid-70s surface dewpoints and PWATs
around 2" (per GOES sounder). Meanwhile, some drier air was
encroaching on the southeast part of the forecast area based on
the latest water vapor loops and objective RAP analysis.
Tallahassee appeared to be on the cusp of the drier air, with a
PWAT of 1.9" on the 12Z sounding. Therefore, the higher rain
chances that were already included in the northwest half of the
forecast area seem on track at this time. Convection-allowing
models (CAM) almost unanimously show fairly widespread
thunderstorm activity just ahead of the front in our SE Alabama
and western Florida Panhandle zones after about 19-20Z. They also
agree that the storms are likely to linger until a few hours after
sunset again, particularly in the Florida Panhandle. PoPs were
bumped up in the Florida Panhandle for the evening hours. With
less convective coverage in the Florida Big Bend and south-central
Georgia, those areas could see highs in the mid-90s again. To the
north and west, highs should be from around 90 to the lower 90s.
The 12Z Tallahassee sounding did indicate stronger E-NE flow than
yesterday, likely due to the influence of the passing tropical
wave to the south of the area. However, radar VWPs and RAP
analysis place the axis of the deep mid-upper level ridge near
the northwest corner of our forecast area with a notable weakness
in the flow. This will likely lead to slow storm motions in the
region with the highest PoPs. Slow storm motions, storm-scale
interactions, and the moist environment will provide adequate
ingredients for localized heavy rainfall. The heavy rain wording
was maintained in the forecast. Some CAMs indicate rainfall rates
as high as 4-5" in just under 2 hours, so isolated flash flooding
will be possible. However, the threat is expected to be isolated
enough to preclude the issuance of a Flash Flood Watch.
&&
.Prev Discussion [642 AM EDT]...
.Short Term [Tonight Through Monday]...
Although weak upper level ridging will continue to dominate the
northern Gulf Coast and SE U.S during the remainder of the weekend
and into early next week (before it is eventually replaced by a trof
towards mid week), plenty of deep layer tropical moisture will
continue to flow into the region from the Gulf of Mexico and western
Atlantic. This will keep PoPs above climo through the short term
period with daytime rain chances generally in the 40-50% range, with
decent PoPs continuing well into the evening hours, especially
tonight over NW portions of the CWA. Temps are expected to remain
above normal as well, with highs mainly in the lower to a few mid
90s away from the coast, with overnight lows in the lower to middle
70s.
.Long Term [Monday Night Through Friday]...
The main uncertainty for the extended forecast is to what extent
the weak system moving westward into the Gulf will impact our
area. The collaborated NHC/WPC forecast takes the system westward
to a position south of Houston by mid-week and keeps it weak. Deep
moisture will continue to increase across the area with a stalled
frontal boundary also in the vicinity. These ingredients point to
an unsettled period coming up with an above average chance of rain
by mid-week. Some locally heavy rain is possible given the weak
boundary and deep tropical moisture expected to be in place. This
could be further enhanced by the Gulf system depending on its
evolution, but that evolution is much more uncertain. Daytime
highs are expected to be held down in the mid 80s from Tuesday
through most of the week given the expected cloud cover and
increased rain coverage.
.Aviation...
[through 12z Sunday] Other than brief patchy fog early, generally
VFR conditions are expected. Scattered to numerous SHRA/TSRA will
develop this afternoon & evening across southeast AL, the FL
Panhandle, & southwest GA, affecting KDHN, KABY, & KECP with
occasional gusty winds, low cigs, and poor vis. Elsewhere VFR
conditions will continue. SHRA/TSRA should slowly diminish around
midnight or shortly after.
.Marine...
Winds and seas will be slightly elevated this weekend as a weak
tropical disturbance passes well to the south of the coastal waters.
Thereafter, a very weak surface pressure pattern will return to the
marine area, with typically low summertime winds and seas expected
once again.
.Fire Weather...
Red Flag conditions are not expected through at least this weekend.
.Hydrology...
As mentioned above, some locally heavy rainfall (with up to 2" to 4"
amounts) will be possible today in some of the slow moving storms to
the north and west of Tallahassee, but any heavy amounts should be
isolated in nature and not have much of a hydrological impact
through early next week. By the middle of the week, however, an
upper level trof will replace the current ridge which will be
retreating westward, and before the cooler and drier air is allowed
to seep into the region by late in the week or next weekend, more
widespread heavy rainfall could fall over the CWA. Should this
occur, some more significant rises along area rivers and streams
could take place, so this situation will be worth monitoring.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 96 73 93 72 92 / 20 30 40 20 50
Panama City 90 76 89 76 89 / 40 60 40 20 50
Dothan 91 72 92 72 92 / 70 60 50 30 50
Albany 92 72 92 73 92 / 50 50 50 30 50
Valdosta 95 71 94 71 93 / 20 30 40 30 50
Cross City 93 72 92 71 92 / 30 40 40 20 50
Apalachicola 90 77 89 76 88 / 20 20 40 20 40
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...GOULD
LONG TERM...DVD
AVIATION...FOURNIER
MARINE...GOULD
FIRE WEATHER...FOURNIER
HYDROLOGY...GOULD
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1019 AM EDT SAT SEP 13 2014
.DISCUSSION...
.UPDATE...
MORNING SOUNDINGS FROM TAMPA AND THE CAPE INDICATE PRECIPITABLE
WATER VALUES RANGING FROM 1.83 TO 1.96 INCHES AND WITH SOUTHERLY LOW
LVL FLOW BACKING TO THE E/ENE ABOVE 700 MBS. AT THE SFC...SOUTHERLY
FLOW THIS MORNING IS FORECAST TO BECOME SE THIS AFTERNOON WITH FLOW
AROUND THE ATLC RIDGE. THE LOW LVL FLOW IS ALSO FORECAST TO BECOME
SE BY THIS AFTERNOON WHICH WILL ALLOWS THE EAST COAST SEA BREEZE TO
DEVELOP AND PUSH INTO THE INTERIOR DURING THE MID TO LATE AFTN HOURS
TODAY. IN THE UPPER LEVELS...AN UPPER LEVEL LOW OFF THE SW FL COAST
IS FORECAST TO MOVE SW WITH ANOTHER UPPER LVL LOW WELL NE FROM THE
NRN BAHAMAS FORECAST TO ALSO GENERALLY MOVE SW THIS AFTN AND
EVENING. THESE FEATURES MAY PROVIDE SOME ADDITIONAL LIFT ACROSS OUR
FAR SRN ZONES WHERE THE DEEPEST MOISTURE WILL RESIDE TODAY. CURRENT
FORECAST LOOKS ON TRACK WITH ONLY SOME SMALL TWEAKS TO POPS/TEMPS.
LOWEST RAIN CHANCES EXPECTED ALONG THE VOLUSIA COUNTY COAST AND
HIGHEST RAIN CHANCES AROUND 40 PCT FROM THE SRN INTERIOR INTO LAKE
COUNTY.
&&
.AVIATION...CURRENT TERMINALS HAVE VCTS IN FOR PORTIONS OF THE
AFTERNOON ALONG SRN TERMINALS BY MID DAY AND INTERIOR TERMINALS THIS
AFTERNOON. RECENT HRRR MODEL RUNS SUGGEST SCT SHRA/TSRA SHOULD DVLP
OVER THE INTERIOR BY MID AFTN AND PUSH WESTWARD TWD LAKE COUNTY AND
KLEE VCTY BY LATE AFTERNOON. WILL MONITOR TRENDS AND MAY ADD SHORT
TEMPO GROUP FOR TSRA AT KLEE LATER THIS AFTN. OTHERWISE EXPECT
MAINLY VFR CONDS OUTSIDE OF SCATTERED CONVECTION MOVING WESTWARD
ACROSS THE INTERIOR IN THE MID-LATE AFTERNOON.
&&
.MARINE...S WINDS AT 6-10 KNOTS AT BUOY 41009 THE LAST SEVERAL HOURS
WITH SEAS AROUND 2.6 FT. WINDS WILL BECOME SE AROUND 10 KNOTS WITH
SEAS MAINLY AROUND 2 FT...POSSIBLY UP TO 2-3 FT OFFSHORE ACROSS THE
NRN OFFSHORE WATERS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
VOLKMER/SEDLOCK
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 AM EDT SAT SEP 13 2014
.DISCUSSION...
.UPDATE...
MORNING SOUNDINGS FROM TAMPA AND THE CAPE INDICATE PRECIPITABLE
WATER VALUES RANGING FROM 1.83 TO 1.96 INCHES AND WITH SOUTHERLY LOW
LVL FLOW BACKING TO THE E/ENE ABOVE 700 MBS. AT THE SFC...SOUTHERLY
FLOW THIS MORNING IS FORECAST TO BECOME SE THIS AFTERNOON WITH FLOW
AROUND THE ATLC RIDGE. THE LOW LVL FLOW IS ALSO FORECAST TO BECOME
SE BY THIS AFTERNOON WHICH WILL ALLOWS THE EAST COAST SEA BREEZE TO
DEVELOP AND PUSH INTO THE INTERIOR DURING THE MID TO LATE AFTN HOURS
TODAY. IN THE UPPER LEVELS...AN UPPER LEVEL LOW OFF THE SW FL COAST
IS FORECAST TO MOVE SW WITH ANOTHER UPPER LVL LOW WELL NE FROM THE
NRN BAHAMAS FORECAST TO ALSO GENERALLY MOVE SW THIS AFTN AND
EVENING. THIS FEATURES MAY PROVIDE SOME ADDITIONAL LIFT ACROSS OUR
FAR SRN ZONES WHERE THE DEEPEST MOISTURE WILL RESIDE TODAY. CURRENT
FORECAST LOOKS ON TRACK WITH ONLY SOME SMALL TWEAKS TO POPS/TEMPS.
LOWEST RAIN CHANCES EXPECTED ALONG THE VOLUSIA COUNTY COAST AND
HIGHEST RAIN CHANCES AROUND 40 PCT FROM THE SRN INTERIOR INTO LAKE
COUNTY.
&&
.AVIATION...CURRENT TERMINALS HAVE VCTS IN FOR PORTIONS OF THE
AFTERNOON ALONG SRN TERMINALS BY MID DAY AND INTERIOR TERMINALS THIS
AFTERNOON. RECENT HRRR MODEL RUNS SUGGEST SCT SHRA/TSRA SHOULD DVLP
OVER THE INTERIOR BY MID AFTN AND PUSH WESTWARD TWD LAKE COUNTY AND
KLEE VCTY BY LATE AFTERNOON. WILL MONITOR TRENDS AND MAY ADD SHORT
TEMPO GROUP FOR TSRA AT KLEE LATER THIS AFTN. OTHERWISE EXPECT
MAINLY VFR CONDS OUTSIDE OF SCATTERED CONVECTION MOVING WESTWARD
ACROSS THE INTERIOR IN THE MID-LATE AFTERNOON.
&&
.MARINE...S WINDS AT 6-10 KNOTS AT BUOY 41009 THE LAST SEVERAL HOURS
WITH SEAS AROUND 2.6 FT. WINDS WILL BECOME SE AROUND 10 KNOTS WITH
SEAS MAINLY AROUND 2 FT...POSSIBLY UP TO 2-3 FT OFFSHORE ACROSS THE
NRN OFFSHORE WATERS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
VOLKMER/SEDLOCK
AREA FORECAST DISCUSSION
NWS MIAMI FL
830 AM EDT SAT SEP 13 2014
.AVIATION...
RATHER DISORGANIZED UPPER LOW, WITH A FEW DISTURBANCES TRAILING
TO THE EAST, WILL BE THE IMPETUS FOR STORMS TODAY. LARGE MASS OF
MID LEVEL DRY AIR PER WATER VAPOR LOOP, MAY STAY NORTH OF THE
REGION TODAY, UNLIKE YESTERDAY. PERHAPS SOME OF THIS DRY AIR WILL
WRAP INTO THE CIRCULATION OF THE UPPER LOW, BUT THAT MAY NOT MEAN
MUCH SINCE THE LOW IS ALREADY OFF THE SW FL COAST. LAMP GUIDANCE
INDICATES THAT A SEA BREEZE WILL DEVELOP ALONG THE EAST COAST,
PERHAPS KEEPING MOST CONVECTION INLAND AND WEST COAST. THIS IS UP
AGAINST THE HRRR WHICH IS AGGRESSIVE PAINTING STORMS ALONG THE
BEACHES AND MOST TERMINALS BY MID AFTERNOON. THE TAFS CAN BE FINE
TUNED ONCE RAOB DATA ARRIVES, BUT WILL INSERT VCTS FOR NOW, AS
PREVIOUS DISCUSSION MENTIONED VCTS FOR ALL TAFS, BUT TAFS ONLY
CONTAINED VCSH. PERHAPS SOME OF THE SHOWERS OFFSHORE OF PBI ARRIVE
LATER THIS MORNING. PERSISTENCE OF CLOUD COVER ALONG THE EAST
COAST WILL ALSO GO A LONG WAY IN DETERMINING STORM EVOLUTION
TODAY. CONFIDENCE IS BELOW AVERAGE.
&&
.PREV DISCUSSION... /ISSUED 431 AM EDT SAT SEP 13 2014/
SHORT TERM...(TODAY-MONDAY)
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED AN UPPER LOW CENTERED OVER
SOUTH FLORIDA SLOWLY TRACKING WESTWARD AND A RIDGE AXIS ORIENTED
FROM EAST TO WEST ACROSS THE NORTHERN GULF COAST STATES. PLENTY OF
DEEP LAYER MOISTURE EAST OF THIS UPPER LOW COMBINED WITH UPPER-LEVEL
DIVERGENCE WILL CONTINUE TO SUPPORT WIDESPREAD RAINFALL TODAY
..ESPECIALLY ALONG THE SOUTHEAST COAST AND ACROSS THE ATLANTIC
WATERS THROUGH THE MORNING HOURS. THE LATEST HRRR MODEL RUN APPEARS
TO HAVE INITIALIZED WELL WITH THE CURRENT RADAR TRENDS AND GENERALLY
INDICATES THIS MORNING ACTIVITY CONTINUING ACROSS THE EASTERN
AREAS INCLUDING PALM BEACH, BROWARD AND MIAMI-DADE BEFORE SHIFTING
INLAND AND TOWARD THE GULF COAST THROUGH THE MID TO LATE
AFTERNOON/EARLY EVENING PERIOD. THIS SOLUTION MAKES SENSE WITH THE
UPPER LOW SHIFTING WESTWARD AND LIGHT TO MODERATE SOUTHEAST LOW-
LEVEL FLOW CONTINUING. THIS PATTERN WILL KEEP THE POTENTIAL FOR
LOCALIZED FLOODING UP THROUGH THIS EVENING...ESPECIALLY OVER THE
AREAS THAT ARE ALREADY SATURATED FROM EARLIER RAINFALL (AREAS HAVE
RECEIVED 2-4 INCHES WITH HIGHER AMOUNTS UP TO 7" JUST INLAND OF
BOCA RATON OVER THE PAST 24-36 HRS). MODEL SOUNDINGS SUPPORT THE
ACTIVITY TAPERING OFF OVER THE FAR SOUTHEASTERN AREAS OR TOWARD
MIAMI THROUGH THE MORNING AND AFTERNOON HOURS WITH MAINLY
SATURATED PROFILES ABOVE A SLIGHTLY DRIER LAYER FROM THE SURFACE
TO 700MB. AS A RESULT...MAXIMUM TEMPERATURES HAVE BEEN SLIGHTLY
UNDERCUT BY A FEW DEGREES COMPARED TO GUIDANCE...MAINLY DUE TO
PLENTY OF CLOUD COVERAGE ANTICIPATED. IF THIS COVERAGE BEGINS TO
BREAK THROUGH THE DAY...TEMPERATURES WILL NEED TO BE ADJUSTED
ACCORDINGLY. THE MOIST TREND WITH SOUTHEAST FLOW WILL PERSIST
THROUGH SUNDAY BEFORE SOME DRIER AIR MOVES IN FROM THE WEST AND
THE RIDGE BUILDS BACK ACROSS THE REGION INTO THE UPCOMING WEEK.
/85
LONG TERM (TUESDAY-FRIDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT ON THE
LARGE SCALE AND GENERALLY INDICATES FALLING UPPER HEIGHTS IN
RESPONSE TO A DEEPENING UPPER TROUGH ACROSS THE REGION. A FRONTAL
BOUNDARY IS PROJECTED TO SHIFT SOUTHWARD AND STALL NORTH OF THE AREA
THROUGH THE SECOND HALF OF THE WEEK. THE ECMWF SEEMS TO BE THE MORE
BULLISH SOLUTION AND SHOWS THE MOISTURE AXIS ASSOCIATED WITH THIS
BOUNDARY PROGRESSING FARTHER SOUTH THAN THE GFS/GFS ENSEMBLE MEAN
WITH SSW LOW-LEVEL FLOW SETTING UP OVER THE AREA BY THURSDAY. THE
COMBINATION OF THE FRONT AND FALLING UPPER HEIGHTS ALONG WITH SSW
LOW-LEVEL FLOW WOULD FAVOR MUCH OF THE RAINFALL SETTING UP OVER THE
EAST COAST/METRO AREAS BY THURSDAY.
/85
AVIATION...
A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS
WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL
VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE
SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE
BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF
SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS AND
GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW PRESSURE
OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL CONTINUE TO
MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE REGION
THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT CONVECTION MAY
LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST METRO AREAS DURING
THE DAY. HOWEVER...DEEP MOISTURE IN THE SOUTHEAST LOW LEVEL FLOW
WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF SITES. AT KAPF...SHOWER
AND STORM DEVELOPMENT IS FORECAST TO BECOME MORE LIKELY AS THE DAY
PROGRESSES...AS THE INFLUENCE OF THE UPPER LOW INCREASES. LIGHT
WINDS WILL CONTINUE THROUGH THE OVERNIGHT HOURS OUTSIDE OF SHOWERS
AND STORMS...AND THEN BECOME SOUTHEAST AROUND 10 KNOTS DURING THE
DAY.
/84
MARINE...
AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE
MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO
MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY
HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL
BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING
WEEK WITH SOUTHEAST WINDS CONTINUING.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 87 76 / 40 30 50 30
FORT LAUDERDALE 84 77 87 79 / 50 40 60 20
MIAMI 85 77 87 78 / 50 40 60 20
NAPLES 87 75 89 76 / 70 30 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...85/AG
LONG TERM....85/AG
AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
431 AM EDT SAT SEP 13 2014
.SHORT TERM...(TODAY-MONDAY)
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED AN UPPER LOW CENTERED OVER
SOUTH FLORIDA SLOWLY TRACKING WESTWARD AND A RIDGE AXIS ORIENTED
FROM EAST TO WEST ACROSS THE NORTHERN GULF COAST STATES. PLENTY OF
DEEP LAYER MOISTURE EAST OF THIS UPPER LOW COMBINED WITH UPPER-LEVEL
DIVERGENCE WILL CONTINUE TO SUPPORT WIDESPREAD RAINFALL TODAY
...ESPECIALLY ALONG THE SOUTHEAST COAST AND ACROSS THE ATLANTIC
WATERS THROUGH THE MORNING HOURS. THE LATEST HRRR MODEL RUN APPEARS
TO HAVE INITIALIZED WELL WITH THE CURRENT RADAR TRENDS AND GENERALLY
INDICATES THIS MORNING ACTIVITY CONTINUING ACROSS THE EASTERN
AREAS INCLUDING PALM BEACH, BROWARD AND MIAMI-DADE BEFORE SHIFTING
INLAND AND TOWARD THE GULF COAST THROUGH THE MID TO LATE
AFTERNOON/EARLY EVENING PERIOD. THIS SOLUTION MAKES SENSE WITH THE
UPPER LOW SHIFTING WESTWARD AND LIGHT TO MODERATE SOUTHEAST LOW-
LEVEL FLOW CONTINUING. THIS PATTERN WILL KEEP THE POTENTIAL FOR
LOCALIZED FLOODING UP THROUGH THIS EVENING...ESPECIALLY OVER THE
AREAS THAT ARE ALREADY SATURATED FROM EARLIER RAINFALL (AREAS HAVE
RECEIVED 2-4 INCHES WITH HIGHER AMOUNTS UP TO 7" JUST INLAND OF
BOCA RATON OVER THE PAST 24-36 HRS). MODEL SOUNDINGS SUPPORT THE
ACTIVITY TAPERING OFF OVER THE FAR SOUTHEASTERN AREAS OR TOWARD
MIAMI THROUGH THE MORNING AND AFTERNOON HOURS WITH MAINLY
SATURATED PROFILES ABOVE A SLIGHTLY DRIER LAYER FROM THE SURFACE
TO 700MB. AS A RESULT...MAXIMUM TEMPERATURES HAVE BEEN SLIGHTLY
UNDERCUT BY A FEW DEGREES COMPARED TO GUIDANCE...MAINLY DUE TO
PLENTY OF CLOUD COVERAGE ANTICIPATED. IF THIS COVERAGE BEGINS TO
BREAK THROUGH THE DAY...TEMPERATURES WILL NEED TO BE ADJUSTED
ACCORDINGLY. THE MOIST TREND WITH SOUTHEAST FLOW WILL PERSIST
THROUGH SUNDAY BEFORE SOME DRIER AIR MOVES IN FROM THE WEST AND
THE RIDGE BUILDS BACK ACROSS THE REGION INTO THE UPCOMING WEEK.
/85
.LONG TERM (TUESDAY-FRIDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT ON THE
LARGE SCALE AND GENERALLY INDICATES FALLING UPPER HEIGHTS IN
RESPONSE TO A DEEPENING UPPER TROUGH ACROSS THE REGION. A FRONTAL
BOUNDARY IS PROJECTED TO SHIFT SOUTHWARD AND STALL NORTH OF THE AREA
THROUGH THE SECOND HALF OF THE WEEK. THE ECMWF SEEMS TO BE THE MORE
BULLISH SOLUTION AND SHOWS THE MOISTURE AXIS ASSOCIATED WITH THIS
BOUNDARY PROGRESSING FARTHER SOUTH THAN THE GFS/GFS ENSEMBLE MEAN
WITH SSW LOW-LEVEL FLOW SETTING UP OVER THE AREA BY THURSDAY. THE
COMBINATION OF THE FRONT AND FALLING UPPER HEIGHTS ALONG WITH SSW
LOW-LEVEL FLOW WOULD FAVOR MUCH OF THE RAINFALL SETTING UP OVER THE
EAST COAST/METRO AREAS BY THURSDAY.
/85
&&
.AVIATION...
A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS
WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL
VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE
SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE
BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF
SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS AND
GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW PRESSURE
OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL CONTINUE TO
MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE REGION
THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT CONVECTION MAY
LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST METRO AREAS DURING
THE DAY. HOWEVER...DEEP MOISTURE IN THE SOUTHEAST LOW LEVEL FLOW
WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF SITES. AT KAPF...SHOWER
AND STORM DEVELOPMENT IS FORECAST TO BECOME MORE LIKELY AS THE DAY
PROGRESSES...AS THE INFLUENCE OF THE UPPER LOW INCREASES. LIGHT
WINDS WILL CONTINUE THROUGH THE OVERNIGHT HOURS OUTSIDE OF SHOWERS
AND STORMS...AND THEN BECOME SOUTHEAST AROUND 10 KNOTS DURING THE
DAY.
/84
&&
.MARINE...
AN UPPER LOW WILL KEEP THE RAIN CHANCES IN THE FORECAST ACROSS THE
MARINE AREAS THROUGH THE REMAINDER OF THE WEEKEND WITH LIGHT TO
MODERATE SOUTHEAST WINDS CONTINUING. WINDS AND SEAS WILL BE LOCALLY
HIGHER IN AND AROUND HEAVIER SHOWERS AND STORMS. HIGH PRESSURE WILL
BUILD BACK ACROSS THE REGION THROUGH THE FIRST HALF OF THE UPCOMING
WEEK WITH SOUTHEAST WINDS CONTINUING.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 87 76 / 40 30 50 30
FORT LAUDERDALE 84 77 87 79 / 50 40 60 20
MIAMI 85 77 87 78 / 50 40 60 20
NAPLES 87 75 89 76 / 70 30 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION...85/AG
AVIATION....84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
205 AM EDT SAT SEP 13 2014
.AVIATION...
A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE ATLANTIC WATERS
WERE DEVELOPING ON THE NORTHEAST SIDE OF THE MID/UPPER LEVEL
VORTICITY MOVING WEST ACROSS THE FLORIDA STRAITS. THESE
SHOWERS/STORMS WERE MOVING QUICKLY TO THE NORTHWEST TOWARDS THE
BROWARD AND MIAMI-DADE TAF SITES...AND THEY MAY MOVE OVER THE TAF
SITES THROUGH THE EARLY MORNING HOURS. BRIEF MVFR/IFR CONDITIONS
AND GUSTY WINDS UP TO 30 KNOTS ARE POSSIBLE. THE AREA OF LOW
PRESSURE OVER THE SOUTHEAST GULF AND THE UPPER LEVEL LOW WILL
CONTINUE TO MOVE WEST TODAY AND HAVE LESS OF AN INFLUENCE OVER THE
REGION THROUGHOUT THE DAY. THIS COMBINED WITH THE OVERNIGHT
CONVECTION MAY LIMIT SHOWER/STORM DEVELOPMENT FOR THE EAST COAST
METRO AREAS DURING THE DAY. HOWEVER...DEEP MOISTURE IN THE
SOUTHEAST LOW LEVEL FLOW WILL CONTINUE...SO KEPT VCTS IN FOR THE TAF
SITES. AT KAPF...SHOWER AND STORM DEVELOPMENT IS FORECAST TO
BECOME MORE LIKELY AS THE DAY PROGRESSES...AS THE INFLUENCE OF THE
UPPER LOW INCREASES. LIGHT WINDS WILL CONTINUE THROUGH THE
OVERNIGHT HOURS OUTSIDE OF SHOWERS AND STORMS...AND THEN BECOME
SOUTHEAST AROUND 10 KNOTS DURING THE DAY.
&&
.PREV DISCUSSION... /ISSUED 944 PM EDT FRI SEP 12 2014/
UPDATE...
ONLY MADE SOME MINOR ADJUSTMENTS TO THE POP GRIDS THIS EVENING.
COULD HAVE LOWERED THEM EVEN MORE THAN I DID, BUT THESE TROPICAL
TYPE SMALL LOW LEVEL CIRCULATIONS CAN BEGIN TO DEVELOP CONVECTION
AT ANY TIME GIVEN THE SOUTHEASTERLY FLOW ON THE EAST SIDE WITH
DEEP TROPICAL AIRMASS. SO EVEN THOUGH NOT MUCH GOING ON AT THE
CURRENT TIME, WAS A LITTLE HESITANT IN MAKING TOO DRASTIC OF A CUT
IN THE POPS. THE HRRR KEEPS THE ACTION QUIET SO LATER UPDATES MAY
BE NEEDED TO LOWER CHANCES MORE IF TRENDS DICTATE.
KOB
PREV DISCUSSION... /ISSUED 739 PM EDT FRI SEP 12 2014/
AVIATION...
LOW PRESSURE CENTERED JUST NORTH OF NAPLES THIS EVENING WILL
CONTINUE DRIFTING WEST INTO THE GULF OF MEXICO...BUT WILL BE THE
MAJOR INFLUENCE ON SOUTH FLORIDA WEATHER THROUGH THE TAF PERIOD.
APPEARS TSRA THREAT OVERNIGHT IS MINIMAL...SO ELECTED TO HAVE VCSH
IN FORECAST INTO SATURDAY MORNING. BY 15Z...SCATTERED/NUMEROUS
SHOWERS/TSTMS EXPECTED...HANDLED NOW BY VCTS BUT TEMPO GROUPS MAY
BE NEEDED ONCE TIMING/COVERAGE BECOME MORE CERTAIN. ESE WINDS WILL
DIMINISH TO 5 KTS OR LESS TONIGHT...THEN INCREASE TO 10-15 KTS BY
SAT AFTN.
PREV DISCUSSION... /ISSUED 344 PM EDT FRI SEP 12 2014/
DISCUSSION...
RECENT WATER VAPOR IMAGERY AND THE LATEST GUIDANCE INDICATES AN
UPPER LEVEL LOW JUST TO THE NORTH OF THE NORTHERN BAHAMAS AND IS
FORECAST TO RETROGRADE WESTWARD TONIGHT INTO SATURDAY.
ELEVATED CHANCES OF SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS
THE REGION TONIGHT INTO SATURDAY. AS THE SURFACE LOW CONTINUES TO
TRACK WESTWARD TONIGHT...IT IS FORECAST TO ENTER THE GULF WATERS
WITH LOW LEVEL SOUTHEASTERLY WINDS FORECAST TO CONTINUE BRINGING
IN DEEP TROPICAL MOISTURE INTO THE REGION TONIGHT INTO SATURDAY.
FOR TONIGHT...THE AFOREMENTIONED UPPER LEVEL LOW IS FORECAST TO
DRIFT WESTWARD WITH 500 HPA VORTICITY FORECAST TO PASS ACROSS THE
REGION TONIGHT INTO SATURDAY. THUS THE INGREDIENTS FOR ADDITIONAL
SHOWERS AND THUNDERSTORMS WILL CONTINUE TONIGHT INTO SATURDAY WITH
ELEVATED POP`S INDICATED IN THE FORECAST.
FOR SATURDAY...WILE THE UPPER LEVEL LOW MAY BE LESS OF A FACTOR AS
IT IS FORECAST TO CONTINUE MOVING WESTWARD...THE SURFACE LOW IS
FORECAST TO BE IN THE EASTERN GULF WITH LOW LEVEL SOUTHEASTERLY
WINDS CONTINUING TO ADVECT ADDITIONAL DEEP MOISTURE INTO THE
REGION. NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS ARE FORECAST
FOR SATURDAY AFTERNOON AND EARLY EVENING HOURS. BY SUNDAY
TROPICAL MOISTURE IS FORECAST TO REMAIN ACROSS THE REGION WITH DAY
TIME HEATING LIKELY TO DEVELOP AFTERNOON SHOWERS AND
THUNDERSTORMS. THE EXTENDED GUIDANCE INDICATES SOME RELATIVELY
DRIER AIR ENTERING THE REGION EARLY NEXT WEEK.
MARINE...
WINDS ARE FORECAST TO BE FROM 10 TO 15 KNOTS THROUGH SATURDAY
THEN DECREASING INTO SUNDAY TO AROUND 10 KNOTS. SEAS 2 TO 3 FEET
POSSIBLE TODAY INTO SATURDAY THEN DECREASING TO 2 FEET OR LESS BY
SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 87 76 / 60 40 50 20
FORT LAUDERDALE 87 77 88 79 / 60 50 50 30
MIAMI 88 77 88 78 / 60 40 40 20
NAPLES 88 74 89 76 / 70 40 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...85/AG
LONG TERM....85/AG
AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1004 PM CDT SUN SEP 14 2014
.DISCUSSION...
240 PM CDT
MAIN FOCUS IS ON OUR NEXT RAIN CHANCE WHICH COMES VERY LATE TONIGHT
THROUGH MUCH OF MONDAY...AND A CONTINUATION OF COOL/BELOW AVERAGE
TEMPS FOR MID-SEPTEMBER.
IN THE NEAR TERM...A PLEASANT BUT STILL COOL WEATHER WAS IN PLACE
ACROSS THE REGION THIS AFTERNOON. SURFACE HIGH PRESSURE WAS CENTERED
OVER THE EASTERN GREAT LAKES...WITH RIDGING EXTENDING SOUTHWEST
ACROSS INDIANA AND ILLINOIS. THE RESULT IS MOSTLY SUNNY AND SLIGHTLY
MILDER CONDITIONS WITH TEMPS REACHING THE MID 60S IN MOST SPOTS AND
UPPER 60S IN A COUPLE IN THE WEST/SOUTH PARTS OF THE CWA. LIGHT
WINDS AND CLEAR SKIES THIS EVENING WILL ALLOW TEMPS TO FALL OFF
FAIRLY QUICKLY HOWEVER...WITH READINGS DROPPING THROUGH THE 50S THIS
EVENING AND INTO THE MID-UPPER 40S LATER TONIGHT BEFORE CLOUDS BEGIN
TO INCREASE AFTER MIDNIGHT.
THIS INCREASE IN CLOUD COVER LATE TONIGHT WILL BE IN ASSOCIATION
WITH A MID-LEVEL SHORT WAVE TROUGH CURRENTLY DIGGING SOUTHEAST FROM
SASKATCHEWAN INTO MONTANA PER AFTERNOON GOES VAPOR IMAGERY.
INCREASING SOUTHERLY LOW LEVEL FLOW WILL DEVELOP AS THIS WAVE DIGS
SOUTHEAST...WITH 925-850 MB LAYER MOISTURE TRANSPORT INCREASING ON
THE NOSE OF A 30-35 KT LOW LEVEL JET WHICH DEVELOPS FROM THE TX/OK
PANHANDLE REGION. THIS AXIS OF MOISTURE TRANSPORT EVENTUALLY WORKS
INTO NORTHERN MISSOURI AND WEST CENTRAL IL MONDAY MORNING AS THE JET
VEERS MORE WEST-SOUTHWESTERLY. WHILE A FEW SHOWERS MAY DEVELOP
ACROSS FAR NORTH CENTRAL IL PRIOR TO SUNRISE...IT APPEARS THAT THE
BEST FORCING WILL ARRIVE SHORTLY AFTER...AS MID-LEVEL VORT
APPROACHES. A COMBINATION OF 40-50 METER HEIGHT FALLS...UPPER
DIVERGENCE BENEATH THE RIGHT REAR ENTRANCE REGION OF A 100+ KT UPPER
JET STREAK OVER THE GREAT LAKES...AND DEVELOPING FRONTOGENETIC
FORCING WITHIN THE LOW-MID LEVELS SHOULD PROVIDE SUFFICIENT FORCING
FOR PRODUCING RAIN/SHOWERS ACROSS THE AREA DURING THE DAY MONDAY.
WITH VARIOUS MODEL QPF AMOUNTS IN THE 0.25 TO 0.35 RANGE...RAIN IS
EXPECTED TO TAPER OFF FROM THE WEST/NORTHWEST LATE MONDAY AFTERNOON
AND EARLY MONDAY EVENING AS THE RELATIVELY PROGRESSIVE DISTURBANCE
MOVES EAST OF THE FORECAST AREA. STRONG HEIGHT RISES THEN ACCOMPANY
DEVELOPMENT OF SURFACE HIGH PRESSURE ACROSS THE MID-MISSISSIPPI
VALLEY MONDAY NIGHT AND TUESDAY.
SURFACE HIGH PRESSURE IS EXPECTED TO LINGER ACROSS THE ACROSS THE
MIDWEST FOR MUCH OF THE REMAINDER OF THE WEEK...SETTING THE STAGE
FOR DRY WEATHER WITH COOL NIGHTS AND COOLER THAN AVERAGE BUT SLOWLY
MODERATING TEMPS THROUGH NEXT WEEKEND. AFTER CLOUD/PRECIP INFLUENCED
TEMPS ONLY IN THE UPPER 50S/LOWER 60S OVER MUCH OF THE AREA
MONDAY...DAYTIME HIGHS SHOULD MODERATE THROUGH THE 60S THROUGH
WEDNESDAY AND THEN FINALLY INTO THE 70S FOR THE END OF THE
WEEK/WEEKEND. COLDEST OVERNIGHT MINS LOOK TO BE LATE MONDAY NIGHT AS
HIGH PRESSURE BUILDS IN WITH LOW 40/A FEW UPPER 30S...WITH LOWS
GRADUALLY MODERATING INTO THE 50S BY THE END OF THE WEEK.
UPPER PATTERN EVOLVES INTO A LONG WAVE TROUGH OVER THE EAST COAST
WITH AN UPPER RIDGE ACROSS THE ROCKIES BY FRIDAY. SLIGHT EASTWARD
PROGRESSION AND FLATTENING OF THE PATTERN ALLOWS RETURN OF
WARMER/HIGHER MOISTURE CONTENT AIR INTO THE REGION INTO THE WEEKEND.
THIS YIELDS AN INCREASING CHANCE OF SHOWERS/THUNDERSTORMS AS A
MID-LEVEL DISTURBANCE PROPAGATES THROUGH THE FLOW AND A SURFACE
TROUGH APPROACHES AND MOVES ACROSS THE AREA FRIDAY NIGHT THROUGH
SUNDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* SOUTHWEST WINDS TURN WESTERLY MIDDAY MONDAY THEN NORTHERLY LATE
AFTERNOON. 350-010 DIRECTION POSSIBLE LATE AFTERNOON/EARLY
EVENING WITH SPEEDS 10+ KT ALSO POSSIBLE FOR A FEW HOURS.
* RAIN INCREASES IN COVERAGE MID MORNING MONDAY...WITH STEADIEST
RAIN MIDDAY/EARLY AFTERNOON BEFORE ENDING LATE AFTERNOON.
* CIGS LOWER LATE MONDAY MORNING WITH MVFR LIKELY BY AROUND
MIDDAY. MVFR SCATTERS TO VFR LATE AFTERNOON/EARLY EVENING.
MDB
//DISCUSSION...UPDATED 00Z...
HIGH PRESSURE REMAINS SPREAD FROM THE ST. LAWRENCE VALLEY AND DOWN
THE OHIO VALLEY THIS EVENING KEEPING SOUTHWESTERLY WINDS ACROSS
THE TERMINALS. SPEEDS WILL DIMINISH TO A FEW KNOTS WITH SUNSET. AN
UPPER TROUGH MOVING ACROSS THE CANADIAN PRAIRIES INTO THE
NORTHERN PLAINS WILL TRACK SOUTHEAST ACROSS THE AREA MONDAY
AFTERNOON. MID AND HIGH CLOUDS WILL STREAM ACROSS THE AREA LATER
TONIGHT WITH RAIN/SHOWERS EXPECTED TO MOVE IN MID/LATE MONDAY
MORNING FROM WEST TO EAST. THE BULK OF THE FORCING WILL PASS
DURING THE MIDDAY/EARLY AFTERNOON HOURS LIKELY BRINGING MORE
WIDESPREAD RAIN TO THE AREA. RAIN LOOKS TO QUICKLY EXIT DURING THE
LATE AFTERNOON AS A SURFACE TROUGH PASSES. CIGS WILL LIKELY LOWER
TO MVFR INTO MIDDAY THEN LOWER END MVFR DURING THE EARLY
AFTERNOON. SOME BRIEF IFR IS ALSO POSSIBLE. WINDS WILL SHIFT
NORTHERLY WITH THE FRONTAL PASSAGE DURING THE LATE AFTERNOON AND
MAY GO AS FAR AS NORTH-NORTHEAST ACROSS NORTHEAST IL. HAVE REDUCED
CONFIDENCE IN WIND SPEEDS DURING THE MID AFTERNOON/EARLY EVENING
HOURS BUT 10-15 KT DOES LOOK POSSIBLE. SOME MVFR MAY LINGER INTO
EARLY EVENING BUT EXPECT A STEADY DECREASE IN COVERAGE BEHIND THE
TROUGH.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN SOUTHWEST TO WEST WINDS MONDAY MORNING
THROUGH MID AFTERNOON. HIGH CONFIDENCE IN SHIFT TO AT LEAST
NORTHWEST...WITH MEDIUM CONFIDENCE IN NORTH AND LOW CONFIDENCE
IN NNW. MEDIUM CONFIDENCE IN SPEEDS 10+ KT WITH THE NORTHERLY
DIRECTION.
* HIGH CONFIDENCE IN RAIN SPREADING ACROSS THE AREA MONDAY. MEDIUM-
HIGH CONFIDENCE IN TIMING.
* MEDIUM-HIGH CONFIDENCE IN MVFR CIGS OCCURRING MONDAY...MEDIUM
CONFIDENCE IN TIMING/DURATION. LOW CONFIDENCE IN POTENTIAL FOR
ANY IFR.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...VFR. NORTHWEST WINDS BECOMING WEST.
WEDNESDAY...VFR. WEST WINDS BECOMING NORTHEAST.
THURSDAY...VFR. EAST WINDS.
FRIDAY...VFR. SOUTHEAST WINDS.
SATURDAY...VFR. BREEZY SOUTH-SOUTHWEST WINDS. CHANCE OF
THUNDERSTORMS.
MDB
&&
.MARINE...
144 PM CDT
HIGH PRESSURE CENTERED OVER THE OHIO VALLEY WILL CONTINUE TO
SLOWLY LIFT NORTHEAST...BECOMING CENTERED OVER NEW ENGLAND MONDAY
MORNING. ALONG THE WESTERN END OF THIS HIGH PRESSURE CENTER IS A
TIGHTER GRADIENT...WHICH HAS BECOME EVIDENT ALONG THE NORTHERN
PORTIONS OF LAKE MICHIGAN WITH WINDS GUSTING AT TIMES TO 30KT FROM
THE SOUTHWEST. A FRONTAL BOUNDARY WILL SWEEP ACROSS LAKE MICHIGAN ON
MONDAY TURNING WINDS WEST/NORTHWEST. THEN ANOTHER RIDGE OF HIGH
PRESSURE WILL BRING ANOTHER PERIOD OF LIGHTER WINDS TO THE LAKE
MONDAY NGT THRU TUE.
HIGH PRESSURE WILL THEN REMAIN IN PLACE THROUGH EARLY
THURSDAY...THEN LIFT NORTHEAST WITH FLOW TURNING SOUTHERLY AND A
TIGHTENING GRADIENT THURSDAY NGT THROUGH FRIDAY. AT THIS TIME IT
IS POSSIBLE WIND COULD GUST TO 30KT FRIDAY NIGHT INTO
SATURDAY...MAINLY FOR THE NORTHERN HALF OF THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
824 PM CDT Sun Sep 14 2014
.UPDATE...
ISSUED AT 823 PM CDT SUN SEP 14 2014
Cyclogenesis occurring over central High Plains this evening in
response to a fast moving short wave moving out of the northern
Rockies. Warm advection precip is developing ahead of the wave and
should move quickly east into the Midwest late tonight. Some minor
differences between model timing of onset. Still fair amount of
dry air evident in 00z KILX sounding, but dew points are climbing
as southerly wind component develops in the boundary layer. Have
made some minor adjustment to wx/pop grids late tonight and
tomorrow to reflect a compromise between HRRR and NAM precip fields.
&&
.SHORT TERM...(Tonight)
ISSUED AT 242 PM CDT SUN SEP 14 2014
High pressure across the Midwest and into the Atlantic northeast
will keep the weather quiet in the early evening hours, but give way
to another quick disturbance moving into the region tonight. A front
moving across the area tonight associated with the disturbance will
bring the chance for showers and isolated thunder into tomorrow
morning. Models have been delaying the precip until after midnight
and have maintained that trend, with pops starting to move in NW of
the Illinois River Valley before 12z. Some of the cloud cover moving
into the region should keep the temps from bottoming out, but still
unseasonably cool with lows in the upper 40s and near 50.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 242 PM CDT SUN SEP 14 2014
There is decent agreement in the models that the track of the best
forcing for precip on Monday looks to remain across northern
Illinois. Therefore we continued to limit the likely PoPs to areas N
of I-72, with chance PoPs south of there. Instability will be weak
at best, but a rumble of thunder could develop for SW areas from
Rushville to Jacksonville.
By Monday evening, any residual lift along a trailing trough will
diminish quickly. It`s entirely possible that all rain may come to
an end by sunset. However, with the forward progress of that trough
slowing, shower chances could linger for at least a few hours into
Monday evening, so we left chance PoPs in place toward I-70.
The widespread clouds and rain across northern areas will keep high
temps on Monday near 60, and we continued to trim numbers a few
degrees below guidance values. With rain holding off until afternoon
and some filtered sun expected south of I-70, highs should get into
the lower 70s.
The colder than normal conditions will last through at least
mid-week as high pressure extends from the Great Lakes and back into
Illinois. Dry conditions are expected, due to the deep layer of dry
air. A weather system approaches western IL on Wed, but all models
curl it to the southeast of IL as high pressure remains in control
of our region.
A stronger system moving across the northern states on Saturday will
drag a cold front across IL Sat night and Sunday. There appears to
be enough instability for a few thunderstorms as mid-level lapse
rates increase and deeper moisture arrives. Chance PoPs were
included Saturday west of I-55, and area-wide for Sat night and
Sunday associated with the frontal passage. Temperatures will warm into
the upper 70s/near 80 by Saturday, with Sunday a few degrees cooler
under clouds and showers.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 600 PM CDT SUN SEP 14 2014
Water Vapor Imagery showing short wave now moving into high plains
rotating through broad long-wave trough over much of the nothern
U.S. Surface reflection begining to develop over northeast
Colorado is expected to push east quickly with the wave.
Gradual increase in VFR clouds overnight will eventually give way
to lower cigs around 12z in western terminals. Still some question
of how low bases will become as it should take some time to
saturate low levels. For now will keep vfr through 17z until have a
better handle on evolution. Showers should overspread all central
Illinois terminals during the morning. Will mention VCTS at KSPI
and KDEC as NAM indicates elevated instability during the morning.
Cold front will push quickly southeast with the best chance of
precip and mvfr conds after 18z once the wave moves by and should
end precip chances by 00z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARKER
SHORT TERM...HJS
LONG TERM...SHIMON/25
AVIATION...BARKER
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1207 AM CDT SAT SEP 13 2014
.AVIATION...
FOR THE 13/00Z TAFS...SCT SHWRS PERSIST GENERALLY ALONG AND S OF
THE I-20 CORRIDOR BUT RADAR LOOPS OVER THE LAST HOUR INDICATE
PRECIP IS BEGINNING TO DISSIPATE. HAVE INCLUDED SOME MENTION OF
RAIN AT A FEW OF THE TAFS SITES FOR THE ONGOING ACTIVITY. CIGS ARE
MVFR/IFR...GENERALLY AROUND OR BELOW 1000 KFT. ONLY A VERY SLIGHT
IMPROVEMENT IS ANTICIPATED THROUGH THE REMAINDER OF THE TAF PERIOD
AS CIGS LIFT SOMEWHAT BUT WILL LIKELY NOT LIFT ABOVE MVFR. POST-
FRONTAL PRESSURE GRADIENT REMAINS TIGHT AND NLY WINDS WILL PERSIST
AROUND 10 KTS WITH A FEW HIGHER GUSTS BUT SPEEDS SHOULD GRADUALLY
DIMINISH AND EVENTUALLY DROP TO AROUND 5 KTS AFTER 14/00Z AS A SFC
HIGH BUILDS INTO THE AREA. /09/
&&
.PREV DISCUSSION... /ISSUED 1015 PM CDT FRI SEP 12 2014/
DISCUSSION...
COLD FRONT SOUTH OF INTERSTATE 20 AND NEARING THE SOUTHERN PARTS
OF EAST AND NORTHEAST TEXAS ACROSS LOWER PARTS OF NORTHWEST AND
NORTH CENTRAL LOUISIANA LATE THIS EVENING. RAIN AND EMBEDDED
HEAVIER SHOWERS CONTINUED ALONG AND IN WAKE OF THE COLD FRONT
AS MOISTURE LIFTS NEAR THE BOUNDARY AND COOLS IN THE COOLER AIR TO
THE RADAR OF THE BOUNDARY. HAVE REMOVED THUNDERSTORMS FROM THE
WORDING OF THE ZONES FOR THE REST OF TONIGHT AND INTO TOMORROW.
SOME ISOLATED THUNDERSTORMS MAY OCCUR BUT MOST LOCATIONS WILL NOT
HAVE THUNDERSTORMS. RAIN WILL TAPER OFF FROM NORTHWEST TO SOUTHEAST.
ADJUSTED THE TEMPERATURES LOWER FOR PARTS OF EAST AND NORTHEAST
TEXAS AND SOUTHEAST OKLAHOMA...WHERE COLD AIR WILL MORE PRONE TO
ENTER THE REGION. /06/
PREV DISCUSSION... /ISSUED 348 PM CDT FRI SEP 12 2014/
DISCUSSION...
OUR WEAK COLD FRONT REMAINS STATIONARY JUST S OF THE I-20 CORRIDOR
OF E TX/N LA THIS AFTERNOON...WITH A LARGE SUCKER HOLE RECENTLY
OPENING UP ACROSS NW LA. TEMPS IN THESE AREAS HAVE WARMED INTO THE
LOWER/MID 80S THIS AFTERNOON...BUT TEMPS REMAIN MUCH COOLER UNDER
THE LOW STRATUS FARTHER W AND N. AS EXPECTED...SCT CONVECTION HAS
DEVELOPED ALONG THE FRONTAL ZONE OVER DEEP E TX...WITH THE WEAK
SEABREEZE APPROACHING THIS AREA AS WELL AS WCNTRL LA FROM SE TX/SW
LA. BELIEVE THAT THIS CONVECTION WILL CONTINUE THROUGH A PORTION
OF THIS EVENING BEFORE DIMINISHING WITH THE LOSS OF
HEATING/INSTABILITY...WITH THE FRONTAL BNDRY EXPECTED TO SLOWLY
DRIFT BACK S ACROSS THIS AREA AND THE SRN SECTIONS OF NCNTRL LA
THIS EVENING/OVERNIGHT. THE HRRR AND TO SOME EXTENT...THE 12Z WRF
DOES INDICATE THE ONGOING CONVECTION POSSIBLY BUILDING BACK A
LITTLE FARTHER NNE TO NEAR/JUST S OF THE I-20 CORRIDOR OF E TX/NW
LA THIS EVENING...WITH ONLY ISOLATED -SHRA EXPECTED FARTHER N
CLOSER TO THE WEAK 850MB TROUGH AS IT REMAINS JUST N OF THE REGION
OVER SE OK/WRN AND CNTRL AR. DID MAINTAIN HIGH CHANCE POPS FOR
AREAS NEAR/S OF THE FRONT THIS EVENING...LOWERING POPS A TAD LATE
AS THE CONVECTION SHOULD WANE ONCE OVERALL FORCING WEAKENS. SHOULD
SEE A WIDE RANGE IN MIN TEMPS OVERNIGHT GIVEN THE SHALLOW NATURE
OF THE POST-FRONTAL AIR MASS...WITH TEMPS POSSIBLY FALLING INTO
THE UPPER 50S OVER SE OK/SW AR.
THE WEAK COLD FRONT IS EXPECTED TO NEAR THE COAST AROUND 12Z
SATURDAY...WITH THE POST-FRONTAL STRATUS HOLDING TOUGH THROUGH THE
DAY. GIVEN THE DEPTH OF THE MOISTURE IN PLACE...DID INSERT SLIGHT
CHANCE POPS AREAWIDE SATURDAY AS ANY WEAK FORCING WILL EASILY
RESULT IN -SHRA DEVELOPMENT...WITH DAYTIME TEMPS ONLY RISING 10
DEGREES OR SO FROM THE MORNING LOWS. THE LOW STRATUS SHOULD BEGIN
TO SLOWLY LIFT SUNDAY...POSSIBLY SCATTERING OUT IN THE AFTERNOON
OVER PORTIONS OF THE REGION. THIS SHOULD RESULT IN MODERATING
TEMPS...ALTHOUGH SFC RIDGING IN PLACE WILL MAINTAIN ABNORMALLY LOW
DEWPOINTS AND COMFORTABLE RH/S FOR THIS TIME OF YEAR. SHOULD BEGIN
TO SEE A RETURN OF HIGHER RH/S BY TUESDAY AS THE BROAD UPPER LEVEL
LOW/TROPICAL WAVE...NOW OVER SRN FL...BEGINS TO SHIFT W ACROSS THE
GULF OF MX THIS WEEKEND AND POSSIBLY IMPACT THE TX COAST.
ATTM...ENOUGH SHEAR ALOFT SHOULD KEEP THIS SYSTEM FROM
INTENSIFYING THIS WEEKEND AND EARLY NEXT WEEK...ALTHOUGH IT WILL
HELP ENHANCE THE SEABREEZE AS IT MOVES INLAND ACROSS SE AND DEEP E
TX/SRN AND CNTRL LA TUESDAY. IN ADDITION...A SHORTWAVE IN THE NW
FLOW ALOFT WILL DROP SE ACROSS THE REGION TUESDAY AS WELL...WHICH
COULD FURTHER ENHANCE FORCING OVER THE SRN SECTIONS OF THE REGION.
HAVE INCREASED POPS TO MID CHANCE S OF I-20 TUESDAY...WITH
CONVECTION DIMINISHING TUESDAY NIGHT/WEDNESDAY AS DRIER AIR ALOFT
MIXES SE IN WAKE OF THIS SHORTWAVE. A DRY NW FLOW LOOKS TO PERSIST
THROUGHOUT THE REMAINDER OF THE WEEK AS UPPER LEVEL RIDGING BUILDS
OVER THE DESERT SW AND THE ROCKIES. TEMPS SHOULD BE NEAR CLIMO
THROUGH THE PERIOD AS WELL.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 64 76 61 85 66 / 30 20 10 10 10
MLU 64 79 61 84 65 / 50 20 10 10 10
DEQ 58 71 57 79 62 / 20 10 10 10 10
TXK 60 73 58 81 63 / 20 20 10 10 10
ELD 61 74 57 81 62 / 30 20 10 10 10
TYR 62 75 61 85 68 / 30 20 10 10 10
GGG 64 76 61 85 66 / 40 20 10 10 10
LFK 67 80 64 88 68 / 60 30 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
436 PM EDT SAT SEP 13 2014
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL MOVE OFF THE COAST THIS
EVENING...BUT A FRONTAL BOUNDARY WILL THEN LAY OFF THE SOUTHEAST
COAST TONIGHT THROUGH MONDAY. MEANWHILE...HIGH PRESSURE WILL BUILD
FROM THE OHIO VALLEY EAST NORTHEAST AND OFF THE NEW ENGLAND COAST
TONIGHT THROUGH MONDAY. ANOTHER TROUGH OF LOW PRESSURE WILL AFFECT
THE AREA MONDAY EVENING INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AREA OF SCTD SHOWERS (ISLTD THUNDER SE) WILL MOVE THRU CNTRL/ERN
CNTIES AND OFF THE CST THIS EVENG...AS A TROF OF LO PRES PUSHES
THRU AND OFFSHR. THEN...BECMG MSTLY CLEAR N TO PRTLY/MSTLY CLOUDY
S TNGT. LOWS RANGING FM THE MID 50S EXTRM N TO THE MID 60S SE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUN THRU MON...A FRONTAL BOUNDARY WILL LAY OFF THE SE CST...WHILE
HI PRES BLDS FM THE OH VLY ENE AND OFF THE NEW ENGLAND CST. THIS
WILL RESULT IN MAINLY DRY WX ACRS THE REGION WITH ONLY SLGT CHCS
FOR PCPN OVR THE EXTRM S. HI TEMPS ON SUN WILL BE IN THE LWR TO
MID 70S...WITH SKY COVER RANGING FM MOSTLY SNY EXTRM N TO MOSTLY
CLOUDY EXTRM S. ABT THE SAME SKY CONDITION SUN NGT WITH LOWS
RANGING THRU THE 50S INTO THE LWR 60S. PARTLY SNY TO MOSTLY CLOUDY
ON MON. WARMER AND BECMG A LITTLE MORE HUMID WITH HIGHS IN THE UPR
70S TO LWR 80S.
WILL THEN HAVE CHC POPS (30-40%) FOR THE ENTIRE REGION MON EVENG
INTO EARLY TUE MORNG...AS ANOTHER TROF OF LO PRES APPROACHES AND
SWINGS THRU. THAT TROF WILL MOVE OUT TO SEA TUE AFTN...WITH HI
PRES BLDNG TWD THE AREA FM THE OH VLY. LOWS MON NGT IN THE 60S.
HIGHS ON TUE RANGING FM THE MID 70S TO NEAR 80.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS AGREE THAT THE COLD FRONT IS WELL OFFSHORE WITH HIGH PRESSURE
BUILDING INTO THE AREA FROM THE NW TO START MEDIUM RANGE PERIOD. DRY
AND COOLER THRU WED NIGHT. LOWS IN THE 50S XCPT 60-65 BEACHES. HIGH
WED 70-75.
PATTERN FOR THE REST OF THE PERIOD WILL FEATURE A LARGE AREA OF HIGH
PRES OVER EASTERN CANADA THAT EXTENDS SOUTH ACROSS THE MID ATLNTC
RGN WITH THE OLD FRONTAL BOUNDARY STALLED ACROSS FLA AND IVOF GULF
STREAM. LOW PRESSURE PROGGED TO MOVE EAST ALONG THIS BNDRY THU AND
FRI. WHAT THIS SCENARIO SUGGESTS IS FOR AN EXTENDED AND INCREASINGLY
MOIST NE FLOW ACROSS THE RGN. TIGHTENING PRES GRAD WILL LEAD TO
BREEZY TO WINDY CNDTNS AT TIMES ALONG THE COAST. TIMING OF PCPN
RATHER PROBLEMATIC THIS FAR OUT BUT WILL CONFINE LOW CHC POPS TO
SERN COASTAL AREAS FOR NOW. PT SUNNY NORTH & WEST TO MSTLY CLDY TO
CLOUDY SKIES SOUTH & EAST. COOL WITH HIGHS U60S-M70S. LOWS IN THE
50S XCPT 60-65 CSTL AREAS.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
WEAK TROF WILL MOVE ACROSS THE AREA THIS AFTERNOON AND EVENING.
THIS IS GENERATING A FEW SHOWERS AS IT MOVES THROUGH THE VERY
MOIST AIR MASS OVER THE AREA. TIMING WHAT WE CAN SEE ON THE RADAR
AND WITH THE HRRR AND RUC ALL SHOW ABOUT A 4 HOUR WINDOW OF
SHOWERS. MAINLY FROM 18 TO 20Z WEST TO 20 TO 00Z EAST. CONDITIONS
WILL BE MVFR DURING THE SHOWERS. AFTER THIS TROF MOVES BY STILL NOT A LOT
OF FLOW ALOFT TO GET RID OF ALL THE MOISTURE. BUFKIT SOUNDINGS
KEEP SOME MID LEVEL MOISTURE AROUND THRU THE NIGHT. SO WILL RAISE
CIGS TO VFR TONIGHT. LOOKS LIKE CONTINUED DRYING ON SUNDAY AND
KEPT VFR CONDITIONS.
OUTLOOK...PCPN AND LOWER CONDITIONS MAY RETURN LATE MONDAY OR TUESDAY
WITH A RETURN TO DRY WEATHER ON WEDNESDAY. STILL UNCERTAINTY ABOUT
TIMING AND HOW FAR NORTH THE MOISTURE WILL GET IN OUR AREA.
&&
.MARINE...
WINDS WILL QUICKLY TURN TO THE NORTH BEHIND THE PASSAGE OF A TROF
THIS EVENING. MODELS STILL DEPICTING A DECENT CAA SURGE LATE TONIGHT
AND SUNDAY MORNING SO WILL KEEP CRNT SCA HEADLINES. ONLY CHANGE WAS
TO BEGING THE SCA HEADLINES WITH THIS ISSUANCE FOR THE CHES BAY
SINCE THE WINDS SHOULD INCREASE TO SCA LEVELS ARND MIDNIGHT. WILL
LET THE STARTING TIME FOR SCA`S ALONE FOR LATE TONIGHT AS THERE ARE
GNRLY FOR 5 FOOT SEAS (ALTHOUGH THERE CUD BE A FEW GUSTS TO 25 KTS
LATE TONIGHT).
SURGE QUICKLY DMNSHS BY SUNDAY AFTRN SO WILL LET THE SCA`S EXPIRE AT
ADVERTISED TIMES. NE FLOW SETS UP SUN NIGHT TINTO MON MORN AT SPEEDS
AOB 15 KTS. WINDS SHIFT INTO THE E-SE MONDAY AFTRN AND EVEN AHEAD OF
NEXT BNDRY.
NEXT COLD FRONTAL PASSAGE EXPECTED TUE MORNING WITH YET ANOTHER
MANGINAL CAA SURGE EXPECTED BEHIND IT. MODELS CONTINUE TO INDICATE
AN EXTENDED PERIOD OF NE (SCA) WINDS AND SEAS AOA 5 FT STARTING
MID WEEK AND PSBLY LASTING INTO NEXT WEEKEND.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR MDZ025.
NC...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR NCZ102.
VA...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR
VAZ098>100.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR ANZ630>632-634-
638.
SMALL CRAFT ADVISORY FROM 6 AM TO 1 PM EDT SUNDAY FOR ANZ633.
SMALL CRAFT ADVISORY FROM 5 AM TO 11 AM EDT SUNDAY FOR ANZ652-
654-656.
SMALL CRAFT ADVISORY FROM 2 AM TO 11 AM EDT SUNDAY FOR ANZ650.
SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM EDT SUNDAY FOR ANZ658.
&&
$$
SYNOPSIS...TMG
NEAR TERM...TMG
SHORT TERM...TMG
LONG TERM...MPR
AVIATION...JAB
MARINE...MPR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
409 PM EDT SAT SEP 13 2014
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL MOVE OFF THE COAST THIS
EVENING...BUT A FRONTAL BOUNDARY WILL THEN LAY OFF THE SOUTHEAST
COAST TONIGHT THROUGH MONDAY. MEANWHILE...HIGH PRESSURE WILL BUILD
FROM THE OHIO VALLEY EAST NORTHEAST AND OFF THE NEW ENGLAND COAST
TONIGHT THROUGH MONDAY. ANOTHER TROUGH OF LOW PRESSURE WILL AFFECT
THE AREA MONDAY EVENING INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AREA OF SCTD SHOWERS (ISLTD THUNDER SE) WILL MOVE THRU CNTRL/ERN
CNTIES AND OFF THE CST THIS EVENG...AS A TROF OF LO PRES PUSHES
THRU AND OFFSHR. THEN...BECMG MSTLY CLEAR N TO PRTLY/MSTLY CLOUDY
S TNGT. LOWS RANGING FM THE MID 50S EXTRM N TO THE MID 60S SE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
MAINLY DRY WEATHER IS EXPECTED SUNDAY THROUGH MONDAY WITH ONLY
SLGT CHANCES FOR PCPN IN THE FAR SOUTH. HIGH TEMPERATURES HOLD IN
THE 70S SUNDAY. DUE TO AN INCREASE OF SUNSHINE FROM EARLIER
FORECASTS...HAVE INCREASED TEMPERATURES TO NEAR 80 OVER MOST
INLAND SECTIONS ON MONDAY WITH READINGS HOLDING IN THE MID 70S ON
THE LOWER EASTERN SHORE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS AGREE THAT THE COLD FRONT IS WELL OFFSHORE WITH HIGH PRESSURE
BUILDING INTO THE AREA FROM THE NW TO START MEDIUM RANGE PERIOD. DRY
AND COOLER THRU WED NIGHT. LOWS IN THE 50S XCPT 60-65 BEACHES. HIGH
WED 70-75.
PATTERN FOR THE REST OF THE PERIOD WILL FEATURE A LARGE AREA OF HIGH
PRES OVER EASTERN CANADA THAT EXTENDS SOUTH ACROSS THE MID ATLNTC
RGN WITH THE OLD FRONTAL BOUNDARY STALLED ACROSS FLA AND IVOF GULF
STREAM. LOW PRESSURE PROGGED TO MOVE EAST ALONG THIS BNDRY THU AND
FRI. WHAT THIS SCENARIO SUGGESTS IS FOR AN EXTENDED AND INCREASINGLY
MOIST NE FLOW ACROSS THE RGN. TIGHTENING PRES GRAD WILL LEAD TO
BREEZY TO WINDY CNDTNS AT TIMES ALONG THE COAST. TIMING OF PCPN
RATHER PROBLEMATIC THIS FAR OUT BUT WILL CONFINE LOW CHC POPS TO
SERN COASTAL AREAS FOR NOW. PT SUNNY NORTH & WEST TO MSTLY CLDY TO
CLOUDY SKIES SOUTH & EAST. COOL WITH HIGHS U60S-M70S. LOWS IN THE
50S XCPT 60-65 CSTL AREAS.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
WEAK TROF WILL MOVE ACROSS THE AREA THIS AFTERNOON AND EVENING.
THIS IS GENERATING A FEW SHOWERS AS IT MOVES THROUGH THE VERY
MOIST AIR MASS OVER THE AREA. TIMING WHAT WE CAN SEE ON THE RADAR
AND WITH THE HRRR AND RUC ALL SHOW ABOUT A 4 HOUR WINDOW OF
SHOWERS. MAINLY FROM 18 TO 20Z WEST TO 20 TO 00Z EAST. CONDITIONS
WILL BE MVFR DURING THE SHOWERS. AFTER THIS TROF MOVES BY STILL NOT A LOT
OF FLOW ALOFT TO GET RID OF ALL THE MOISTURE. BUFKIT SOUNDINGS
KEEP SOME MID LEVEL MOISTURE AROUND THRU THE NIGHT. SO WILL RAISE
CIGS TO VFR TONIGHT. LOOKS LIKE CONTINUED DRYING ON SUNDAY AND
KEPT VFR CONDITIONS.
OUTLOOK...PCPN AND LOWER CONDITIONS MAY RETURN LATE MONDAY OR TUESDAY
WITH A RETURN TO DRY WEATHER ON WEDNESDAY. STILL UNCERTAINTY ABOUT
TIMING AND HOW FAR NORTH THE MOISTURE WILL GET IN OUR AREA.
&&
.MARINE...
WINDS WILL QUICKLY TURN TO THE NORTH BEHIND THE PASSAGE OF A TROF
THIS EVENING. MODELS STILL DEPICTING A DECENT CAA SURGE LATE TONIGHT
AND SUNDAY MORNING SO WILL KEEP CRNT SCA HEADLINES. ONLY CHANGE WAS
TO BEGING THE SCA HEADLINES WITH THIS ISSUANCE FOR THE CHES BAY
SINCE THE WINDS SHOULD INCREASE TO SCA LEVELS ARND MIDNIGHT. WILL
LET THE STARTING TIME FOR SCA`S ALONE FOR LATE TONIGHT AS THERE ARE
GNRLY FOR 5 FOOT SEAS (ALTHOUGH THERE CUD BE A FEW GUSTS TO 25 KTS
LATE TONIGHT).
SURGE QUICKLY DMNSHS BY SUNDAY AFTRN SO WILL LET THE SCA`S EXPIRE AT
ADVERTISED TIMES. NE FLOW SETS UP SUN NIGHT TINTO MON MORN AT SPEEDS
AOB 15 KTS. WINDS SHIFT INTO THE E-SE MONDAY AFTRN AND EVEN AHEAD OF
NEXT BNDRY.
NEXT COLD FRONTAL PASSAGE EXPECTED TUE MORNING WITH YET ANOTHER
MANGINAL CAA SURGE EXPECTED BEHIND IT. MODELS CONTINUE TO INDICATE
AN EXTENDED PERIOD OF NE (SCA) WINDS AND SEAS AOA 5 FT STARTING
MID WEEK AND PSBLY LASTING INTO NEXT WEEKEND.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR MDZ025.
NC...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR NCZ102.
VA...MODERATE RIP CURRENT RISK THROUGH SUNDAY EVENING FOR
VAZ098>100.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR ANZ630>632-634-
638.
SMALL CRAFT ADVISORY FROM 6 AM TO 1 PM EDT SUNDAY FOR ANZ633.
SMALL CRAFT ADVISORY FROM 5 AM TO 11 AM EDT SUNDAY FOR ANZ652-
654-656.
SMALL CRAFT ADVISORY FROM 2 AM TO 11 AM EDT SUNDAY FOR ANZ650.
SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM EDT SUNDAY FOR ANZ658.
&&
$$
SYNOPSIS...TMG
NEAR TERM...TMG
SHORT TERM...TMG
LONG TERM...MPR
AVIATION...JAB
MARINE...MPR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
148 PM EDT SAT SEP 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN OVER THE CAROLINAS THROUGH EARLY NEXT
WEEK. A TROUGH OF LOW PRESSURE WILL MOVE FROM WEST TO EAST ACROSS
THE MID ATLANTIC STATES THIS AFTERNOON AND EARLY TONIGHT. HIGH
PRESSURE BUILDS INTO THE AREA FROM THE NORTHWEST SUNDAY AND
MONDAY. ANOTHER LOW PRESSURE SYSTEM WILL AFFECT THE AREA MONDAY
NIGHT AND TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AREA OF SCTD SHOWERS WAS MOVING INTO WRN/CNTRL CNTIES LATE THIS
MORNG...AND WILL SPREAD ACRS THE REGION FM W TO E THIS AFTN INTO
TNGT...AS A TROF OF LO PRES PUSHING ACRS THE AREA AND OFF THE CST.
WILL MAINTAIN LIKELY POPS (60-70%) EVERYWHERE THRU THIS
AFTN...EVEN THO RAINFALL AMTS WILL GENERALLY BE .25 INCH OR LESS
OVR MOST OF THE RGION. HIGHER AMTS POSSIBLE OVR NE NC LATER TODAY
INTO TNGT. INSTABILITY WILL BE MARGINAL IN THE SE...SO HAVE JUST
SLGT CHC OF TSTM. HI TEMPS RANGING FM THE LWR 70S EXTRM NW TO THE
LWR 80S EXTRM SE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
MAINLY DRY WEATHER IS EXPECTED SUNDAY THROUGH MONDAY WITH ONLY
SLGT CHANCES FOR PCPN IN THE FAR SOUTH. HIGH TEMPERATURES HOLD IN
THE 70S SUNDAY. DUE TO AN INCREASE OF SUNSHINE FROM EARLIER
FORECASTS...HAVE INCREASED TEMPERATURES TO NEAR 80 OVER MOST
INLAND SECTIONS ON MONDAY WITH READINGS HOLDING IN THE MID 70S ON
THE LOWER EASTERN SHORE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
CONTINUED TO FAVOR THE ECMWF SOLN DURING THIS PERIOD. LOW PRESSURE
AND ASSCTD COLD FRONT MOVE ACROSS THE AREA MON NIGHT AND TUE. THIS
RUN A BIT FASTER WITH FROPA (TUES MORNING) THEN SHIFTS OFFSHORE.
SOME INSTAB NOTED AHEAD OF BNDRY SO WILL KEEP CHC POPS THRU THE
PERIOD WITH THUNDER CHCS OVR SRN SCTNS. MILD AHEAD OF THE BNDRY
WITH LOWS MON NITE IN THE 60S. HIGHS TUE 75-80.
FRONTAL BNDRY STALLS ACROSS THE CAROLINAS AS CANADIAN HIGH PRESSURE
BUILDS INTO THE AREA FOR THE MID WEEK PRD. MOST OF THE SGNFCNT MSTR
GETS PUSHES JUST SOUTH OF THE FA...SO WILL INDCT A DRY PRD WED AND
WED NIGHT. COOLER WITH LOWS IN THE 50S XCPT 60S BEACH AREAS. HIGHS
WED 70-75.
GIVEN HIGHS PRS TO THE NORTH AND STALLED FRNTL BNDRY TO THE SOUTH...
XPCT THE PERSISTENT & INCREASINGLY MOIST NE FLOW TO KEEP CSTL
AREAS RTHR CLDY WITH PERIODIC SHWR CHCS ACROSS SERN CSTL AREAS.
OTW...HIGH PRS TO THE NORTH DOMINATES. HIGHS L-M70S. LOWS IN THE
50S XCPT 60S CSTL AREAS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
WEAK TROF WILL MOVE ACROSS THE AREA THIS AFTERNOON AND EVENING.
THIS IS GENERATING A FEW SHOWERS AS IT MOVES THROUGH THE VERY
MOIST AIR MASS OVER THE AREA. TIMING WHAT WE CAN SEE ON THE RADAR
AND WITH THE HRRR AND RUC ALL SHOW ABOUT A 4 HOUR WINDOW OF
SHOWERS. MAINLY FROM 18 TO 20Z WEST TO 20 TO 00Z EAST. CONDITIONS
WILL BE MVFR DURING THE SHOWERS. AFTER THIS TROF MOVES BY STILL NOT A LOT
OF FLOW ALOFT TO GET RID OF ALL THE MOISTURE. BUFKIT SOUNDINGS
KEEP SOME MID LEVEL MOISTURE AROUND THRU THE NIGHT. SO WILL RAISE
CIGS TO VFR TONIGHT. LOOKS LIKE CONTINUED DRYING ON SUNDAY AND
KEPT VFR CONDITIONS.
OUTLOOK...PCPN AND LOWER CONDITIONS MAY RETURN LATE MONDAY OR TUESDAY
WITH A RETURN TO DRY WEATHER ON WEDNESDAY. STILL UNCERTAINTY ABOUT
TIMING AND HOW FAR NORTH THE MOISTURE WILL GET IN OUR AREA.
&&
.MARINE...
SFC HI PRES MOVES OFF TO THE NE OF THE WTRS THROUGH TDA. ONSHORE
WNDS (LIGHTER THAN PAST 24 HRS) THROUGH THE MRNG...BECOME BRIEFLY
SSW AHD OF APPROACHING LO PRES AND ASSOCIATED CDFNT FM THE W.
SUB-SCA CONDS XPCD THROUGH THIS EVE. THAT CDFNT CROSSES THE WTRS MID
EVE...A BIT OF A LULL IN SPEEDS AS WNDS BECOME NLY POST FROPA. AS
SFC HI PRES FM THE OH VLY BUILDS E TNGT...SPEEDS TO INCRS TO 15-20
KT OVR MOST OF THE WTRS AFT MDNGT...AND RESULT IN INCRS IN WAVES
(BAY)/SEAS (OCN) THROUGH SUN MRNG. WNDS TO BEGIN TO SUBSIDE
MIDDAY/AFTN SUN AND WAVES/SEAS WILL BE SLO TO LWR AS WELL (LASTLY
INVOF FAR SRN OCN WTRS). RAISING SCAS FOR BAY/OCN/SND...MNLY FM AFT
MDNGT TNGT THROUGH MRNG/EARLY AFTN SUN.
ANOTHOR LO PRES SYS AND ASSOCIATED CD CDFRNT PROGGED ACROSS THE AREA
MON NGT AND TUE. EXPECT W-SW FLOW AHEAD OF THIS SYS
SHIFTING BACK TO THE N AFT FROPA WITH YET ANOTHER CAA SURGE
LIKELY. DATA INDICATES THAT AN EXTENDED PERIOD OF NE WINDS AND
INCREASED SEAS APPEAR LIKELY LATE NEXT WEEK.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR
MDZ025.
NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR
NCZ102.
VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR
VAZ098>100.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EDT SUNDAY
FOR ANZ630>632-634-638.
SMALL CRAFT ADVISORY FROM 6 AM TO 1 PM EDT SUNDAY FOR ANZ633.
SMALL CRAFT ADVISORY FROM 5 AM TO 11 AM EDT SUNDAY FOR ANZ652-
654-656.
SMALL CRAFT ADVISORY FROM 2 AM TO 11 AM EDT SUNDAY FOR ANZ650.
SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM EDT SUNDAY FOR ANZ658.
&&
$$
SYNOPSIS...LSA
NEAR TERM...TMG/LSA
SHORT TERM...LSA/JAB
LONG TERM...MPR
AVIATION...LSA
MARINE...ALB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EDT SAT SEP 13 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 409 PM EDT SAT SEP 13 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE VIGOROUS SHORTWAVE
THAT PRODUCED PCPN OVER MUCH OF UPPER MI LAST NIGHT NOW MOVING THRU
SRN ONTARIO INTO QUEBEC. UPSTREAM...A PAIR OF SHORTWAVES ARE
NOTED...ONE OVER ND/SRN MANITOBA AND THE OTHER OVER SRN
SASKATCHEWAN. THESE WAVES WILL BRING THE NEXT PCPN CHC TO UPPER MI
ON SUNDAY. IN THE WAKE OF LAST NIGHTS SYSTEM...850MB TEMPS ARE
CURRENTLY -1 TO -2C OVER LAKE SUPERIOR. TYPICALLY AT THIS TIME OF
YEAR...THIS WOULD BE MORE THAN SUFFICIENT FOR LAKE EFFECT CLOUDS AND
PCPN. HOWEVER...WITH A LARGE PORTION OF LAKE SUPERIOR HAVING SFC
WATER TEMPS PROBABLY ONLY AROUND 7-9C...THERE WAS NOT MUCH IN THE
WAY OF LAKE EFFECT CLOUDS EARLIER TODAY. IN FACT...THE LAKE HAS
BEHAVED MOSTLY AS STABILIZING INFLUENCE. ONE BAND WITH A FEW
SPRINKLES DID STREAM INTO ERN MARQUETTE COUNTY BRIEFLY THIS MORNING
DUE TO LAND BREEZE CONVERGENCE AND WARMER WATER TO THE S AND E OF
THE KEWEENAW. THIS AFTN...DAYTIME HEATING/LOW-LEVEL CONVERGENCE AND
MOISTURE FROM THE LAKE RESULTED IN ADDITIONAL SPRINKLES DEVELOPING
IN ERN MARQUETTE COUNTY. THESE SPRINKLES ARE DRIFTING SE THRU DELTA
AND WRN ALGER COUNTIES. WHILE LAKE EFFECT CLOUDS WERE AT A MINIMUM
EARLIER TODAY...850MB THERMAL TROF COMBINED WITH ADDED MOISTURE FROM
THE LAKE RESULTED IN WIDESPREAD CU/STRATOCU DEVELOPING OVER THE LAND
ONCE DAYTIME HEATING BEGAN.
TONIGHT...MAIN FCST CONCERN IS FROST POTENTIAL. WHILE CU/STRATOCU IS
STILL QUITE EXTENSIVE...THE DIURNAL NATURE OF THE CLOUD DEVELOPMENT
SUGGESTS THE CLOUDS WILL DISSIPATE THIS EVENING WITH THE LOSS OF
DAYTIME HEATING. MEANWHILE...LEAD SHORTWAVE TO THE W IS GENERATING A
FAIR AMOUNT OF HIGH CLOUDINESS WHICH WILL STREAM OVER THE FCST AREA
AS THE WAVE MOVES OVER THE UPPER LAKES. DISSIPATING STRATOCU THIS
EVENING BEING REPLACED BY HIGH CLOUDS WILL BE ONE FACTOR HELPING TO
KEEP TEMPS FROM CRASHING. OTHER FACTOR WILL BE DEPARTURE OF HIGH
PRES RIDGE CURRENTLY OVER THE AREA. AS PRES GRADIENT TIGHTENS BTWN
THE EXITING HIGH AND APPROACHING SFC TROF... THERE WILL BE SOME
INCREASE IN MIXING. THAT SAID...THE INITIAL DRY AIR MASS
(PRECIPITABLE WATER 45-55PCT OF NORMAL) AND LIGHT WINDS OVER THE
AREA WILL STILL ALLOW TEMPS TO FALL INTO THE MID 30S AND TO EVEN THE
LOWER 30S IN TRADITIONAL COLD SPOTS. SO...FCST WILL SHOW PATCHY
FROST OVER MUCH OF THE INTERIOR. AT THIS POINT...NOT EXPECTING
COVERAGE TO BE LARGE ENOUGH TO WARRANT A FROST ADVY. EVENING SHIFT
WILL NEED TO MONITOR CLOUD TRENDS AND TEMPS TO RE-EXAMINE THE NEED
FOR HEADLINE ISSUANCE BY LATE EVENING.
ON SUN...SECOND SHORTWAVE WILL SWING ACROSS THE UPPER GREAT LAKES.
AS IN PREVIOUS DAYS...MODELS CONTINUE TO INDICATE BEST
MOISTURE/FORCING PASSING JUST N OF THE AREA...ALONG AND N OF
PROJECTED VORT TRACK. SEE NO REASON TO DEVIATE MUCH FROM PREVIOUS
FCST WITH MAINLY CHC POPS SPREADING INTO WRN UPPER MI IN THE MID TO
LATE MORNING AND THEN REACHING THE E MID TO LATE AFTN. EXPECT HIGH
TEMPS GENERALLY IN THE UPPER 50S TO LWR 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 350 PM EDT SAT SEP 13 2014
SPLIT FLOW PATTERN ALOFT TO START THE LONG TERM PERIOD BUT NORTHERN
BRANCH IS BY FAR STRONGER AND MORE INFLUENTIAL ON THE WEATHER OVER
MUCH OF NORTH AMERICA. TROUGHING CENTERED OVER NUNAVUT CANADA TO THE
NORTH OF HUDSON BAY WILL KEEP A TROUGH/BELOW NORMAL TEMPS OVER MOST
OF CANADA AND INTO THE GREAT LAKES AND REST OF THE EASTERN CONUS
THIS WEEK. RIDGING OVER THE WESTERN CONUS AND WESTERN CANADA SHOULD
SLOWLY SLIDE EAST BY THE END OF THE WEEK AS DEEP TROUGH CURRENTLY
OVER ALASKA RE-ORIENTS OVER THE GULF OF ALASKA WHILE SLIGHTLY
OPENING UP. MAY SEE A WARM UP LATE THIS WEEK AND BEYOND AS
RIDGING...OR AT LEAST LESS TROUGHING...AFFECTS THE PLAINS AND GREAT
LAKES. PATTERN DOES NOT LOOK TO PROVIDE MUCH IN WAY OF RAIN THE NEXT
WEEK. PRIMARY CHANCES WOULD BE WITH COLD FRONT MOVING THROUGH ON
TUESDAY NIGHT AND AGAIN BY NEXT WEEKEND AS WARM AIR ADVECTION STARTS
TO SPREAD IN FROM THE WEST.
SUNDAY NIGHT INTO MONDAY...SHORTWAVE AND ASSOCIATED COLD FRONT MOVES
OUT OF EASTERN CWA AFTER MIDNIGHT ON SUNDAY NIGHT. WILL LINGER SLIGHT
CHANCE POPS OVER THE EAST AFTER MIDNIGHT. THERMAL TROUGH WITH LOWER
H7 TEMPS AND A POCKET OF H85-H7 RH ALONG WITH DAYTIME HEATING MAY
RESULT IN ISOLD SHRA VCNTY OF LAKE BREEZES OVER EASTERN CWA ON
MONDAY AFTN. DRYING AND SUBSIDENCE IN WAKE OF THE SUNDAY NIGHT
SHORTWAVE SHOULD LIMIT COVERAGE AND WILL ONLY KEEP SLIGHT CHANCES.
LI/S ARE A BIT BLO 0C BUT THINK THAT WITH FROPA WITHIN PREVIOUS 12
HR...THERE WILL ONLY BE ENOUGH INSTABILITY FOR SHRA SO DID NOT
MENTION ANY THUNDER.
SFC RIDGE SETTLES FROM THE NORTHERN PLAINS TO THE OHIO VALLEY BY
TUESDAY MORNING. COULD BE HIGH CLOUDS ON MONDAY NIGHT...BUT PWATS
ARE BLO 50 PCT OF NORMAL SO IT COULD BE CHILLY NIGHT WITH SOME FROST
POSSIBLE. WINDS LIGHT NEAR THE RIDGE AND THERE IS LIMITED ONSHORE
COMPONENT ANYWHERE IN CWA...SEEMS THAT ALL INTERIOR WOULD BE AT RISK
FOR THE COLD TEMPS/FROST. TUESDAY SHOULD BE DRY AS UPPER LAKES IS
BTWN THE RIDGE AND AN APPROACHING COLD FRONT. WSW WINDS AHEAD OF
FRONT AND H85 TEMPS UP TO 4-6C SHOULD RESULT IN TEMPS INTO THE 60S
WHICH IS AT LEAST CLOSER TO NORMAL. FRONT DROPS NORTH TO SOUTH OVER
THE AREA ON TUESDAY NIGHT OR WEDNESDAY MORNING. A BRIEF INTERLUDE OF
INCREASING H8-H6 MOISTURE AND WEAK LIFT JUST IN WAKE OF THE FRONT
MAY BE ENOUGH TO KICK OFF SOME SHOWERS TUESDAY NIGHT. COVERAGE OF
ANY SHOWERS WILL BE HELD BACK AS STRONGER FORCING FOR LIFT REMAINS
OVER NORTHERN ONTARIO CLOSER TO TRACK OF UPPER LEVEL JET DIGGING
INTO THE PERSISTENT TROUGH. INTO WEDNESDAY...COULD BE A LOT OF LOW
CLOUDS LINGERING BENEATH SUBSIDENCE ALOFT AS SUB H85 IT REMAINS COOL
AND MOIST WITH EASTERLY FLOW. ADDITIONAL MID CLOUDS MAY STREAM ACROSS
IN THE AFTN AS WELL. TEMPS WILL BE MUCH COOLER THAN THE DAY BEFORE
AND IT WILL ESPECIALLY FEEL THAT WAY WITH THE CLOUDS AND EAST WIND.
TEMPS IN THE LOW 50S NEAR LK SUPERIOR AND NEAR 60 OVER THE SCNTRL.
AS TROUGH ALOFT OVER EASTERN CANADA AND THE NORTHEAST CONUS SLOWLY
MOVES EAST AND RIDGE OVER WESTERN CONUS ALSO MOVES EAST...CONFLUENT
FLOW RESULTS IN SFC RIDGE MOVING FROM CNTRL CANADA ACROSS THE GREAT
LAKES AND EVENTUALLY TO THE EASTERN SEABOARD BY SATURDAY. DRY WEATHER
SHOULD HOLD OVER UPPER LAKES THROUGH THU NIGHT...WITH CHANCES
FOR RAIN INCREASING BY NEXT WEEKEND AS SHORTWAVE TROUGH MOVES TO THE
CNTRL PLAINS AND SFC FRONT SLIDES EASTWARD. LATEST GFS WHICH HAD
BEEN VERY AGRESSIVE IN PREVIOUS MODEL RUNS BRINGING QPF TO THE
UPPER GREAT LAKES BY FRIDAY NOW LOOKS SIMILAR TO THE SLOWER 00Z
ECMWF. ON THE FLIP SIDE...THE LATEST ECMWF IS MUCH MORE BULLISH
BRINGING QPF ACROSS ALL OF UPR MICHIGAN BY FRIDAY AFTN AS WHERE IT
HAD BEEN INSISTENT ON A RIDGE...IT HAS A STRONGER SHORTWAVE TROUGH.
MODEL CONSISTENCY IS LACKING AND WILL GO WITH A CONSENSUS OF ALL THE
MODELS WITH LOW CHANCES FOR SHRA/TSRA BEGINNING ON FRIDAY AND
LASTING INTO NEXT WEEKEND. GENERALLY...TEMPS WILL RUN BELOW NORMAL
THE UPCOMING WEEK...THOUGH IT DOES APPEAR THAT IN ADDITION TO THE
WARMER TEMPS ON TUESDAY AHEAD OF A COLD FRONT...READINGS ON FRIDAY
AND SATURDAY MAY TRY TO PUSH TO AROUND NORMAL. WILL ALL DEPEND ON
EXTENT OF CLOUDS AND SHRA/TSRA. COUPLE OF CHILLY NIGHTS POSSIBLE
WEDNESDAY NIGHT AND THURSDAY NIGHT AS THE HIGH IS IN THE VCNTY AND
PWATS ARE WELL BLO 50 PCT OF NORMAL. IF SKIES ARE MAINLY CLEAR
EITHER NIGHT...TEMPS COULD BE AROUND FREEZING AND THERE WOULD BE
FROST. ATTM...BEST CHANCE FOR IDEAL RADIATIONAL COOLING CONDITIONS
WOULD BE ON WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 137 PM EDT SAT SEP 13 2014
UNDER RELATIVELY DRY LOW LEVELS...VFR CONDITIONS WILL PREVAIL THRU
THE FCST PERIOD AT KIWD/KCMX/KSAW. THERE ARE A COUPLE OF MINOR
CONCERNS. A FEW -SHRA/SPRINKLES THAT HAVE POPPED UP IN THE KSAW
VCNTY SHOULD LINGER FOR THE NEXT COUPLE OF HRS. ON SUN...AN
APPROACHING LOW PRES TROF SHOULD BRING SCT -SHRA INTO NW UPPER MI BY
AFTN. HAVE INCLUDED A VCSH MENTION AT KCMX...BUT DO NOT EXPECT
CONDITION TO FALL BLO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT SAT SEP 13 2014
APPROACHING LOW PRES TROF WILL RESULT IN INCREASING S TO SW WINDS
TONIGHT INTO SUN. WHILE LOWER OBS PLATFORMS SHOULDN`T SEE WINDS
GREATER THAN THE 10-20KT RANGE...HIGH OBS PLATFORMS WILL PROBABLY
SEE GUSTS TO AROUND 25KT. WINDS SHOULD FALL BACK TO MOSTLY 10-20KT
SUN NIGHT THRU MON. THERE MAY BE SOMEWHAT HIGHER WINDS AGAIN LATE
MON NIGHT THRU EARLY WED AHEAD OF AND BEHIND A COLD FRONT THAT WILL
DROP S ACROSS LAKE SUPERIOR TUE. LIGHTER WINDS WILL THEN BE THE RULE
LATER WED THRU THU HAS HIGH PRES MOVE SE ACROSS NRN ONTARIO TOWARD
THE LOWER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
650 PM CDT SUN SEP 14 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 246 PM CDT SUN SEP 14 2014
ALTHOUGH NOWHERE NEAR AS INTERESTING ON SATELLITE AS HURRICANE ODILE
IN THE ERN PAC...WATER VAPOR IMAGERY WITH RAP H5 ANALYSIS DOES SHOW
A STRONG WAVE CURRENTLY WORKING SOUTH ACROSS MANITOBA. THIS WAVE
WILL DIVE SE ACROSS NODAK AND SRN MN TONIGHT AND ACROSS CENTRAL WI
MONDAY. THIS IS A PRETTY POTENT WAVE...WITH THE NAM SHOWING THE 1.5
PV SFC /APPROXIMATE TROPOPAUSE LEVEL/ GETTING DOWN TO H5. BESIDE THE
PV ADVECTION OUT AHEAD OF THE WAVE...A FAIRLY STRONG BAND OF FGEN
WILL BE SETTING UP ACROSS SRN MN IN THE H7-H6 LAYER.
HOWEVER...CONCURRENT WITH THIS FORCING IN THE H7-H6 LAYER IS A VERY
DRY LAYER OF AIR BETWEEN H8 AND H7 THAT RAP SOUNDINGS SHOW NOW BEING
IN PLACE ACROSS THE AREA. MAJORITY OF SHORT TERM MODELS /BOTH CAMS
AND NON-CAMS/ SHOW THIS DEFORMATION BAND SETTING UP FROM RWF TO THE
SRN TWIN CITIES METRO AND OVER TO EAU. ALTHOUGH WE HAVE THAT DRY AIR
TO WORK WITH...FORCING LOOKS TO BE AROUND LONG ENOUGH TO ALLOW LIGHT
RAIN TO FALL ALONG THE LINE MENTIONED ABOVE. MAY SEE RAIN FOR
SEVERAL HOURS TONIGHT...BUT WILL BE A STRUGGLE TO EVEN GET TO A
TENTH OF AN INCH. WHAT THIS DRY AIR WILL DO IS RESULT IN A VERY
TIGHT PRECIP GRADIENT...WITH POP FORECAST AS OF 3 PM HAVING NEAR 50
POPS DOWN TOWARD LAKEVILLE...WITH NEAR ZERO BY THE TIME YOU GET TO
ANOKA.
AFTER 6Z...A STRONGER BURST OF RAIN LOOKS TO COME INTO SW MN AND
TRACK ACROSS I-90 THROUGH 12Z AND THIS IS ASSOCIATED WITH THE PV
FEATURE MOVING THROUGH. THIS AREA OF PRECIP LOOKS TO BE A BIT MORE
EFFICIENT AT PRODUCING RAIN...SO WENT WITH AN ECMWF/GFS/HPC QPF
BLEND...WHICH RESULTED ABOUT A QUARTER INCH OF RAIN FORECAST BETWEEN
MKT AND THE IOWA BORDER TONIGHT ALONG WITH CATEGORICAL POPS.
FOR TEMPERATURES...DID BOOST LOWS SOME ACROSS SRN MN...WHERE CLOUDS
WILL LIMIT THE AMOUNT OF COOLING...BUT VERY LITTLE CHANGE WAS MADE
TO THE FORECAST TOMORROW...AS SKIES LOOK TO CLEAR OUT IN THE
MORNING...WITH A BEAUTIFUL EARLY FALL DAY ENSUING THEREAFTER WITH
HIGHS IN THE UPPER 50S TO MID 60S...CLOSE TO WHAT A BLEND OF THE
BIAS CORRECTED RAW MODEL GUIDANCE GIVES YOU.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 246 PM CDT SUN SEP 14 2014
A SURFACE HIGH BUILDS IN ACROSS THE FORECAST AREA ON MONDAY AS THE
RAIN AND CLOUD COVER MOVE OUT DURING THE AFTERNOON. A DRY AND COOL
ATMOSPHERIC COLUMN IS EXPECTED TUESDAY THROUGH THURSDAY. TUESDAY
COULD STILL BE QUITE COOL AS MN/WI REMAIN ON THE BACK SIDE OF AN
850MB COLD POCKET STRETCHING EASTWARD TOWARD THE GREAT LAKES.
THERE IS A WEAK SURFACE TROUGH AND INSTABILITY POOLING ALONG A
MOISTURE AXIS STRETCHING FROM THE SOUTHERN PLAINS INTO NORTH
CENTRAL SD TUESDAY/TUESDAY NIGHT...BUT THERE DOESN`T SEEM TO BE
MUCH CONVERGENCE AT THIS TIME AND THE BOUNDARY WOULD REMAIN WELL
SOUTHWEST OF THE AREA ANYWAY. SO...ZERO POPS IT IS TUESDAY AND
WEDNESDAY. THERE IS 925-850MB WARM ADVECTION ON WEDNESDAY AND
THURSDAY...SO THERE COULD BE A LITTLE MORE WARMING THAN WHAT IS
CURRENTLY IN THE FORECAST. WHILE MONDAY AND TUESDAY SHOULD FEATURE
PLENTY OF 60S DURING THE AFTERNOON...THERE IS THE POTENTIAL FOR
LOW 70S IN MN WEDNESDAY AND THURSDAY AFTERNOON. IT ALSO LOOKS LIKE
OVERNIGHT LOWS IN THE COMING WEEK SHOULD BE WELL ABOVE THE
FREEZING MARK...SO THERE IS VERY LITTLE THREAT OF MORNING FROST
THIS COMING WEEK.
THE NEXT CHANCE FOR PRECIP AFTER MONDAY WILL HAVE TO WAIT UNTIL AT
LEAST FRIDAY WHEN BOTH THE 14.12Z GFS/ECMWF DEPICT LIGHT QPF ACROSS
THE FORECAST AREA. THE MODELS DON`T REALLY SHOW MUCH MOISTENING BELOW
700MB BEFORE SHORTWAVE ENERGY MAKES IT INTO THE EASTERN HALF OF
MN...SO MUCH OF THE FORECAST AREA MIGHT END UP WITH VERY LIGHT RAIN
OR VIRGA DURING THE DAY ON FRIDAY /OR NOTHING/.
NONETHELESS...THERE IS GOOD LOW LEVEL SOUTHWEST FLOW AND
TEMPERATURE ADVECTION DURING THE DAY WITH A MODEST INCREASE IN
INSTABILITY...ESPECIALLY IN WESTERN AND SOUTHERN MN. THE TIMING OF
THE WAVE THROUGH THE DAY ON FRIDAY AND INTO SATURDAY IS STILL
UNCERTAIN. THE 12Z ECMWF IS FASTER THAN THE GFS...AND THE GFS ALSO
DEVELOPS A WEAK SECONDARY LOW NEAR THE COLD FRONT AND SATURDAY.
THIS WOULD PROLONG THE PRECIP WELL INTO THE WEEKEND...HOWEVER...THE
LAST 4-5 RUNS OF THE GFS HAVE REALLY LACKED CONSISTENCY. WE ARE
CARRYING CHANCE POPS FOR SHOWERS WITH EMBEDDED THUNDER FOR NOW
WITH THAT THE IDEA THAT A BROKEN BAND OF SHOWERS WILL SWING
THROUGH WITH THE COLD FRONT FRIDAY NIGHT OR SATURDAY MORNING. IF
THERE IS A LESSON TO BE LEARNED OVER THE PAST COUPLE MONTHS...IT`S
THAT THE HEAVIER SHOWERS AND MORE ROBUST THUNDERSTORMS WILL END UP
SOUTH OF THE FORECAST AREA IN IOWA AND PORTIONS OF IL AND SOUTHERN
WI...WHERE THE HIGHEST INSTABILITY IS FORECAST TO BE LOCATED.
STILL SOME TIME TO WORK THIS LATE WEEK SYSTEM OUT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 638 PM CDT SUN SEP 14 2014
A NARROW STRIPE OF VIRGA CURRENTLY EXTENDS EASTWARD ACROSS SRN MN.
AS THE LOWER ATMOSPHERE MOISTENS AND THE BEST FORCING ARRIVES
LATER THIS EVENING...RAIN WILL EXPAND FROM RWF EASTWARD TO RGK AND
SOUTH ALTHOUGH PERIODS OF LIGHT RAIN COULD ALSO DRIFT OVER MSP
FROM TIME TO TIME. REGARDLESS...VFR CONDITIONS AND LIGHT WINDS
EXPECTED THROUGH MONDAY.
KMSP...BEST RAIN CHANCES APPEAR TO BE FROM 03Z-09Z...ALTHOUGH IT
MAY TAKE A BIT LONGER TO ARRIVE GIVEN RADAR TRENDS.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS SW AT 10 KTS.
WED...VFR. WINDS SSE AT 5 KTS.
THU...VFR. WINDS SE AT 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1039 AM CDT SAT SEP 13 2014
.UPDATE...DECREASED HOURLY TEMPERATURES AND OVERALL HIGHS FOR TODAY
WITH EXPECTED CLOUD COVER AND LOW-LEVEL COLD AIR ADVECTION TO
PERSIST. HAVE ALSO REMOVED THUNDER WORDING FOR SE AREAS WHERE FRONT
HAS PASSED THROUGH ALREADY.
.DISCUSSION...LOW STRATUS CLOUDS AND POCKETS OF LIGHT DRIZZLE
BLANKET THE ENTIRE REGION AS LOW-LVL COLD AIR ADVECTION OCCURS IN
LOWEST 150MB WITH NORTH SURFACE WINDS AT 10-15 MPH. THIS IS LEADING
TO SOME OF THE COOLEST READINGS OF THE LATE SUMMER SEASON WITH
TEMPERATURES STILL IN THE LOW 60S NORTH TO UPPER 60S CENTRAL AND LOW
70S SOUTH. WITH LOW STRATUS TRAPPED UNDERNEATH INVERSION PER
OBSERVED AND BUFR SOUNDINGS, FEEL CLOUD COVER WILL PERSIST AT GOOD
WHILE INTO THE EARLY TO MID AFTERNOON AND THUS KEEP TEMPERATURES AND
INSTABILITY LOW. EVENTUAL MIXING SHOULD HELP SLOW EROSION OF CLOUDS
IN SE BUT IT MAY BE TOO LITTLE TO LATE FOR INSTABILITY TO BUILD FOR
ANY THUNDERSTORM POTENTIAL. SSEO AND LATEST RUC ANALYSIS DEPICT
BETTER TSTORM ENVIRONMENT WILL BE DISPLACED FARTHER SOUTH AND EAST
OF PINE BELT. CLOUDS WILL SLOWLY ERODE FROM THE NORTH AS WELL BUT
I-20 CORRIDOR MAY BE IN CENTRAL POINT WHERE IT PERSISTS THE LONGEST.
HAVE FOLLOWED CLOSE TO GFS LAMP TRENDS THROUGH THE DAY AS IT SEEMS
TO BE CAPTURING THE CAA WELL. AN UPDATED AVIATION DISCUSSION CAN BE
FOUND BELOW. /ALLEN/
&&
.AVIATION...MORNING IFR CIGS WL GRADUALLY RISE TO MVFR CIGS THIS
AFTN AS AN ABUNDANCE OF COLD ADVECTION STRATUS WILL IMPACT TAF SITES
TODAY AND PERHAPS INTO TONIGHT. LINGERING RAIN CHANCES WILL BE
MOSTLY CONFINED IN THE HBG/PIB TO MEI AREA...BUT BY THIS EVENING
EXPECT MOST OF THE AREA TO BE RAIN-FREE. LOW LEVEL MIXING SHOULD BE
STRONG ENOUGH LATE TONIGHT AND EARLY SUNDAY MORNING TO LIMIT ANY FOG
POTENTIAL. /EC/22/
&&
.PREV DISCUSSION... /ISSUED 426 AM CDT SAT SEP 13 2014/
DISCUSSION...
TODAY THROUGH SUNDAY NIGHT...
STRONG SURFACE HIGH PRESSURE (1031 MB) CENTERED OVER THE PLAINS AND
MIDWEST IS RESPONSIBLE FOR TODAY`S SHALLOW COOL AIR INTRUSION
BENEATH THE THE SUBTROPICAL RIDGE (591 DM). THE COLD ADVECTION IS
LEADING TO A CONSIDERABLE AMOUNT OF STRATUS AND EXPECT THIS TO
CONTINUE FOR MOST OF THE DAY RESULTING IN RATHER COOL AFTERNOON
TEMPERATURES THAT WILL STRUGGLE TO REACH THE LOWER 70S IN THE UPPER
DELTA REGION. THE EXCEPTION TO THIS WILL BE IN THE HATTIESBURG AREA
WHERE WEAKER COLD ADVECTION AND LESS LOW CLOUD COVER SHOULD ALLOW
TEMPERATURE TO REACH THE LOW TO MID 80S. AS WE GO FROM TONIGHT INTO
SUNDAY...THE AIRMASS WILL BEGIN TO MODIFY AND ALLOW FOR SLIGHTLY
WARMER TEMPERATURES. MODELS AGREE THAT DEEPER MOISTURE WILL BEGIN TO
RETURN...ESPECIALLY BY SUNDAY AFTERNOON AND EVENING ALONG THE I-59
CORRIDOR FROM HBG TO MEI. /EC/
MONDAY THROUGH NEXT SATURDAY...
PRETTY GOOD AGREEMENT REMAINS BETWEEN THE GFS AND ECMWF THIS MORNING
IN REGARDS TO THE WEATHER ACROSS THE FORECAST AREA THROUGH MUCH OF
THE LONG TERM PERIOD. DECENT RAIN CHANCES LOOK TO REMAIN IN THE
FORECAST MONDAY THROUGH WEDNESDAY IN THE VICINITY OF A SLOW TO WASH
OUT BOUNDARY MEANDERING ABOUT AND AFFECTING MAINLY THE SOUTHERN HALF
OF THE ARKLAMISS. MOST OF THIS ACTIVITY LOOKS TO MAINLY BE CONFINED
TO THE AFTERNOON AND EARLY EVENING HOURS...BUT SOME COULD LINGER INTO
THE OVERNIGHT HOURS. BIGGEST CONCERN DURING THIS TIME WILL BE THE
POTENTIAL FOR HEAVY RAINFALL...AGAIN PRIMARILY IN THE SOUTH...AS
PRECIPITABLE H2O VALUES REMAIN AROUND THE 2.00 INCH RANGE.
RAIN CHANCES LOOK TO DECREASE THURSDAY THROUGH SATURDAY AS A DECENT
SURGE OF DRIER AIR FILTERS SOUTH AND DEEPER INTO THE CWA AS HIGH
PRESSURE BUILDS INTO THE REGION FROM THE NORTH. IF THIS INDEED
UNFOLDS...IT SHOULD BRING A NOTICEABLY DRIER FEEL TO THE AIR...ALONG
WITH SOME SLIGHTLY COOLER DAYTIME AND OVERNIGHT TEMPERATURES THROUGH
AT LEAST SATURDAY. UNTIL THEN...LOOK FOR A CONTINUATION OF HUMID
CONDITIONS MONDAY THROUGH WEDNESDAY AS HIGHS CLIMB TO NEAR 90 AND
LOWS GENERALLY RANGE FROM THE MID 60S TO AROUND 70. OBVIOUSLY
MONDAY THROUGH WEDNESDAY...AFTERNOON CONVECTION AND ASSOCIATED CLOUD
COVER WILL PLAY A LARGE ROLL IN HOW WARM MOST LOCATIONS GET...
ESPECIALLY ALONG AND SOUTH OF THE INTERSTATE 20 CORRIDOR. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 77 64 85 68 / 21 11 14 12
MERIDIAN 80 64 87 67 / 25 14 21 16
VICKSBURG 76 61 84 66 / 21 13 11 9
HATTIESBURG 86 68 91 71 / 37 14 27 21
NATCHEZ 76 63 85 68 / 29 14 18 13
GREENVILLE 72 58 82 63 / 20 11 9 9
GREENWOOD 73 58 83 62 / 20 10 10 10
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
ALLEN/22/EC/19
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1127 PM CDT Fri Sep 12 2014
.UPDATE:
Issued at 1027 PM CDT Fri Sep 12 2014
Issued at 620 PM CDT Fri Sep 12 2014
cloud cover continues to slowly recede southeastward across north-
central Missouri. Light to moderate drizzle still continues over
much of central Missouri into southwest and central Illinois.
Light to moderate drizzle will continue over parts of central and
much of east-central - southwest illinois through early Saturday
morning. Cloud cover will slowly recede southward with time. But
will still continue to linger beyond 0900 UTC. Surface winds will
be dimishing to 5 kts after 0600 UTC. temperatures will drop intot
he upper 30s over far northeast Missouri tonight under clear
skies. Should be a fine day on Saturday with partly cloudy skies
and mild tempatures over the region as surface high pressure
builds over the area. Could reach record lows for far northeast
Missouri and again on Sunday morning for northeast through central
Missouri.
Przybylinski
&&
.SHORT TERM: (Through Tonight)
Issued at 236 PM CDT Fri Sep 12 2014
Cloud cover continues to cover the area this afternoon as stratus is
trapped under a low level inversion and mid-high level clouds are
streaming in ahead of a mid level trough. There has been some light
rain associated with the mid-level trough moving across northern
Missouri early this afternoon, but it`s coverage has been limited.
Latest runs of the RAP and HRRR still show some redevelopment of
some light rain over western Missouri this afternoon and this
evening ahead of the upper trough that will move across the CWA this
evening. Then expect clearing of the clouds from north to south
after 06Z as the upper trough moves to the east allowing subsidence
to set in. Drier air will move into the low levels as the inversion
weakens which should allow the low level clouds to move out.
Temperatures should fall close to agreeable MOS guidance for lows
once skies begin to clear with the light northeasterly winds.
Britt
.LONG TERM: (Saturday through Next Friday)
Issued at 236 PM CDT Fri Sep 12 2014
(Saturday through Monday)
Overall, mdls are in good agreement thru this period. Period begins
with a large sfc ridge settling across the region. This ridge will
keep temps around 15 degrees below seasonal average despite ample
insolation. As the ridge retreats, the approaching trof and sfc fnt
will bring another chance for precip to the region late in the
period. Some minor differences in timing are apparent among the mdl
guidance. Will keep PoPs lower except where mdls are in agreement.
(Tuesday through Friday)
Not much change from the prev forecast. Mdls remain in good
agreement overall thru the period with respect to mass fields
anyway. Sfc ridge builds into the region on Tues with precip coming
to an end Mon night. Cool temps will prevail thru mid week, tho not
as cool as this weekend. Mdls differ regarding precip chances for
late Wed into Thurs. The ECMWF is more robust with nocturnal
convection developing along a stationary fnt across the region. The
GFS would suggest height rising with the sfc ridge still holding on
into the area. Have kept PoPs low given the uncertainty forecasting
mesoscale features on day 7.
As for temps, have trended twd the warmer guidance thru the period
given heights over the region.
Tilly
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1119 PM CDT Fri Sep 12 2014
Subsidence and dry air advection at low levels are significantly
eroding the MVFR stratus in place across the region. The clearing
line has already moved through KUIN and KCOU and should reach St.
Louis metro TAF sites during 06-09z. There could be some isolated
spots of fog once clearing occurs, but the combination of drying
low levels and sustained winds AOA 7kts should act to limit any
fog formation to those sheltered areas with higher low-level
moisture. Generally VFR conditions are expected thereafter.
Kanofsky
&&
.CLIMATE:
Issued at 236 PM CDT Fri Sep 12 2014
Record Lows This Weekend:
STL COU UIN
13 43(1975) 33(1902) 33(1902)
14 46(1996) 40(1892) 38(1996)
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1135 PM CDT FRI SEP 12 2014
.UPDATE...
ISSUED AT 924 PM CDT FRI SEP 12 2014
OPTED TO EXPAND THE FROST ADVISORY FOR JUST A COUPLE OF COUNTIES
WHERE TEMPS ARE FORECAST TO DROP TO NEAR 36. MAY ALSO SEE SOME
PATCHY FOG OVERNIGHT. IT MAY BE VERY THIN GROUND FOG...AND MAYBE
MORE STEAM FOG NEAR THE RIVERS AND LAKES. MAY HAVE TO ADD TO THE
FORECAST IF IT BECOMES WIDESPREAD OR DENSE ENOUGH...AND WILL
CONTINUE TO MONITOR THROUGH THE NIGHTTIME. FOG HAD ALREADY
DEVELOPED AT CLARINDA IOWA AND MILLARD...AND LATEST RAP MODEL
SUGGESTS IT COULD EXPAND ESPECIALLY ACROSS WESTERN IOWA WHERE
WINDS WILL PROBABLY REMAIN CALM OVERNIGHT.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 319 PM CDT FRI SEP 12 2014
...FIRST FROST OF THE SEASON EXPECTED FOR PARTS OF THE AREA...
THE MAIN CONCERN CONCERN FOR THE SHORT TERM CONTS TO BE WITH THE
COLD WEATHER TONIGHT. WE FEEL THAT MOST LOCATIONS WILL FALL SHORT
OF THE RECORDS LOWS...BUT WITH SKIES CLEARING...WINDS DIMINISHING
THIS EVENING...AND THE SFC HIGH CROSSING THE CWA OVERNIGHT WE ARE
IN FOR THE COLDEST NIGHT YET OF THE EARLY FALL SEASON. GOING
FORECAST LOWS WERE IN GOOD SHAPE AND VERY FEW CHANGES WERE MADE
THERE...BUT WE DID GO AHEAD AND ISSUE A FROST ADVRY FOR PARTS OF
THE AREA THAT WILL LIKELY SEE A COUPLE HOURS OF TEMPERATURES AT OR
BELOW ABOUT 36 DEGREES. RETURN FLOW STARTS TO KICK ON ON SAT BUT
TEMPERATURES WILL REMAIN BELOW NORMAL DESPITE THE MIXING TO 850
MB. LOWS TEMPERATURES WILL BE A BIT WARMER ON SAT NIGHT AHEAD OF
A FRONT THAT WILL START TO WORK INTO THE MID MO RVR VALLEY ON SUN.
ALL MODELS ARE IN PRETTY GOOD AGREEMENT ON THE EVOLUTION OF THE
SENSIBLE WX ASSOCIATED WITH THE FRONT ON SUN/SUN NIGHT ALLOWING
FOR INCREASED CONFIDENCE AND HIGHER POPS. MOISTURE RETURN WILL BE
LIMITED BUT ISENTROPIC LIFT WILL INCREASE DURING THE DAY ON SUN
LEADING TO INCREASING CLOUDS...AND AS LARGE-SCALE FORCING FOR
ASCENT ALSO INCREASES LATE ON SUN AFTN...AS A SHORT-WAVE TROUGH
WORKS THRU SD...WE SHOULD SEE AN INCREASE IN SHRA AND MAYBE AN
ISO TSRA OR TWO. THIS CHANCE WILL CONT TO INCREASE ON SUN NIGHT
AND WE WILL HAVE SOME LIKELY POPS IN THE CNTRL AND SRN CWA. THE
FRONT WILL SHIFT SOUTH OF OUR AREA ON MON ALLOW FOR ANOTHER SHOT
OF COOLER AIR TO MOV IN FOR MON AND MON NIGHT AND WE HAVE LOWERED
HIGHS/LOWS DURING THIS TIME.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 319 PM CDT FRI SEP 12 2014
SENSIBLE WEATHER WILL BE PRETTY QUIET IN THE EXTENDED PERIOD OF
THE FORECAST. THE OVER-ALL PATTERN WILL TRANSITION FROM NORTHWEST
FLOW AND COOL AT THE START OF THE PERIOD TO WESTERLY AND A BIT
WARMER AT THE END. THE PERIOD WILL GENERALLY BE DRY BUT AS THE
UPPER LEVEL FLOW TURNS MORE WEST WE WILL SEE AN INCREASE IN
MOISTURE THAT MAY LEAD TO SOME CHC FOR PRECIP TOWARDS THE END OF
THE PERIOD...ESPECIALLY IN THE NORTHERN CWA CLOSER TO A BOUNDARY.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1134 PM CDT FRI SEP 12 2014
VFR CONDITIONS THROUGH THE PERIOD...ALTHOUGH ALL TAF SITES MAY SEE
SOME PATCHY MVFR FOG 09-13Z. LIGHT AND VARIABLE WINDS BECOME SOUTH
AT 12-16 KNOTS BY 16Z...COULD SEE GUSTS UP TO ABOUT 20-22 KNOTS AT
KLNK/KOFK THAT WOULD LINGER THROUGH ABOUT 00Z. THEN WINDS BECOME
AT OR BELOW 10 KNOTS BY 00Z AND BEYOND.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...FROST ADVISORY FROM 3 AM TO 9 AM CDT SATURDAY FOR NEZ015>018-
030>034-042>045-050-051-065-066-078-088-089.
IA...FROST ADVISORY FROM 3 AM TO 9 AM CDT SATURDAY FOR IAZ043-055-056-
069-079-080-090-091.
&&
$$
UPDATE...DEWALD
SHORT TERM...BOUSTEAD
LONG TERM...BOUSTEAD
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
948 PM EDT SUN SEP 14 2014
.SYNOPSIS...
HIGH PRESSURE WILL RESIDE OVER THE AREA THROUGH MONDAY PROVIDING
DRY WEATHER AND COOL TEMPERATURES. THE FIRST PATCHY FROST IS
POSSIBLE...MAINLY THE UPPER SUSQUEHANNA...WESTERN CATSKILLS...AND
TUG HILL PLATEAU REGIONS OF NEW YORK AS WELL AS STEUBEN COUNTY.
MONDAY NIGHT INTO EARLY TUESDAY MORNING A COLD FRONT WILL PASS
THROUGH THE AREA BRINGING A PERIOD OF SHOWERS. TEMPERATURES WILL
REMAIN ON THE COOL SIDE THE NEXT SEVERAL DAYS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
945 PM UPDATE...
CLOUD SHIELD ADVANCING THROUGH CENTRAL NY AS PER MODEL GUIDANCE.
FROST LIKELIHOOD LOOKING RATHER LOW FOR STEUBEN COUNTY, A BIT
HIGHER CHANCES ACROSS THE CATSKILLS. PER DISCUSSION BELOW I
THOUGHT ABOUT TAKING OUT STEUBEN COUNTY. WITH SOME BREAKS IN THE
CLOUDS TO THE WEST, WILL TAKE THE PATH OF LEAST REGRET AND LEAVE
ADVISORY IN PLACE. WITH THAT SAID THE FORECAST ITSELF IS MAINLY
37-40 IN THESE AREAS, WITH PATCHY FROST/FOG OVER ONLY A 2 HOUR
WINDOW. BOTTOM-LINE IS MOST OF THESE ARES WILL PROBABLY STAY FROST
FREE DUE TO CURRENT CLOUD COVER.
825 PM UPDATE...
MADE SOME MAJOR ADJUSTMENTS TO THE GRIDS TO INCREASE SKY COVER
THROUGH THE FINGER LAKES/WESTERN SOUTHERN TIER AND LOWER
PROBABILITY OF FROST/FOG HERE WHILE RAISING TEMPS SLIGHTLY. IT APPEARS
THE NAM MODEL WAS CORRECT AS CURRENT 11-3.9 MICRON SATELLITE ALONG
WITH OBS CONFIRM AN EXTENSIVE CLOUD SHIELD AROUND 5KFT OVER THE
WESTERN HALF OF THE CWA. THIS THIN LAYER WAS FIRST SHOWN BY THE
12Z NAM, AND NOW LATER RUNS OF THE 18Z GFS AND LATEST RUC ARE
PICKING UP ON THIS LAYER. IF THE MODELS CONTINUE TO BE CORRECT
THIS CLOUD SHIELD WILL REMAIN IN PLACE, WHILE EXPANDING TO THE
EAST THROUGH THE REST OF THE OVERNIGHT. I WAS TEMPTED TO DROP THE
FROST ADVISORY FOR STEUBEN COUNTY BASED ON THIS BUT WANTED TO WAIT
ANOTHER HOUR OR SO TO SEE IF CLEARING IN WESTERN NY MOVES EAST.
FOR NOW I PUSHED BACK THE TIMING OF BOTH FROST AND FOG FROM THE
BINGHAMTON AREA, WESTWARD, UNTIL CLOSER TO DAYBREAK ITSELF. WILL
REEVALUATE AND TRY TO MAKE A DECISION ON LOWERING ANY PRODUCTS BY
10 PM.
4 PM UPDATE... MAIN ISSUE OF THE NEAR TERM IS THE LIKELY
FIRST FROST FOR SOME PARTS OF THE AREA TONIGHT.
MOST CLOUD COVER WAS EATEN UP BY MIXING DOWN OF DRY AIR.
EXCEPTIONALLY DRY AIR EXISTS JUST ABOVE THE SUBSIDENCE
INVERSION...WITH 12Z BUFFALO SOUNDING DEWPOINTS REACHING AT LEAST
MINUS-45 CELSIUS IN THE 750-600MB LAYER AND MODEL SOUNDINGS IN OUR
AREA EVEN AROUND MINUS-60. PRECIPITABLE WATER VALUES ONLY AROUND A
QUARTER TO THIRD OF AN INCH. SURFACE DEWPOINTS ARE NOW IN UPPER
30S-LOW 40S FAHRENHEIT AND WILL PROBABLY DIP SOME MORE THE NEXT
HOUR OR TWO AS DIURNAL HEATING AND MIXING PEAKS.
SURFACE RIDGE EXTENDED UP THE ONTARIO PENINSULA EARLY THIS
MORNING...AND AWAY FROM THE LAKES TEMPERATURES THERE DIPPED IN
THE 30S BY DAWN WHERE IT STAYED CLEAR. IT SERVES AS A GOOD HINT OF
WHAT WILL OCCUR FOR PARTS OF OUR AREA...WITH THIS VERY DRY AIR
MASS...AND THE SURFACE HIGH PULLING DIRECTLY OVERHEAD TONIGHT.
THERE IS A BIG SPREAD IN GUIDANCE FOR LOWS TONIGHT...MAINLY A
PRODUCT OF DETAILS FOR WHERE SOME CLOUD COVER MAY REMAIN TRAPPED
UNDER THE SUBSIDENCE INVERSION. GUIDANCE IN GENERAL /ESPECIALLY
MAV/ HAS BEEN TOO COOL RECENTLY FOR NIGHTTIME LOWS...YET WHERE IT
STAYS CLEAR RADIATIONAL CONDITIONS WILL BE IDEAL TONIGHT.
DESPITE RH FIELDS IN SOME MODELS DEPICTING LAYER OF MOISTURE AROUND
900-850MB ADVECTING IN FROM THE WEST LATE TONIGHT...POSITION OF
THE SURFACE HIGH AND DRYNESS OF AIR MASS SUGGESTS THAT MOST CLOUDS
/EVEN JUST TO OUR WEST/ WILL ERADICATE WITH LOSS OF DIURNAL
HEATING. WHILE NOT GOING TO THE BOTTOM OF MODEL GUIDANCE...I DID
AT LEAST LEAN THAT DIRECTION BECAUSE OF EXPECTATION IN MAINLY
CLEAR CONDITIONS OVERNIGHT. I HAVE HOISTED FROST ADVISORY FOR
ONEIDA-MADISON-CHENANGO-OTSEGO-DELAWARE-SULLIVAN COUNTIES IN THE
EAST...AS WELL AS STEUBEN COUNTY IN THE WEST...WHERE CONFIDENCE IN
FROST-YIELDING TEMPERATURES IS HIGHEST. THIS ALSO HAPPENS TO BE
CLIMATE-WISE WHERE FROST TENDS TO OCCUR FIRST IN OUR REGION. THE
COLDEST VALLEYS IN EASTERN FRINGES OF OTSEGO-DELAWARE COUNTIES
COULD EVEN GET TO AROUND FREEZING...SUCH AS CHERRY VALLEY AND
ROXBURY.
FOR THE REMAINDER OF THE TWIN TIERS...PATCHY FROST IS STILL
POSSIBLE BUT NOT AS LIKELY NOR WITH AS MUCH COVERAGE COMPARED TO
THE ADVISORY COUNTIES. THE ADVISORY COULD BE AMENDED IN AREA
THOUGH BASED ON TRENDS. HOWEVER...VALLEY FOG IN THE MAIN STEM
RIVER VALLEYS OF THE TWIN TIERS MAY KEEP TEMPERATURES FROM
PLUMMETING TO FROST-PRONE READINGS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
415 PM UPDATE...
THE HIGH PRESSURE RESPONSIBLE FOR FROST CONCERNS TONIGHT...WILL
SHIFT OFF THE EAST COAST MONDAY. THIS WILL INITIATE A
SOUTHWESTERLY MODERATING FLOW...AND TEMPERATURES WARMING TO ABOUT
5-9 DEGREES HIGHER THAN TODAY /SUNDAY/. INITIAL SUNSHINE WILL
YIELD TO INCREASING CLOUDS FROM THE WEST BY LATE AFTERNOON.
MONDAY NIGHT/TUESDAY...UPPER LEVEL TROUGH AND ASSOCIATED COLD
FRONT WILL MOVE THROUGH THE REGION. MODELS ARE IN EXCELLENT
AGREEMENT WITH THIS FEATURE...AND HONED GRIDS IN ACCORDINGLY WITH
HIGH CONFIDENCE POPS /70-80 PCT RANGE/ SWEEPING THROUGH DURING THE
NIGHTTIME HOURS. NO INSTABILITY...SO ONLY SHOWERS
EXPECTED...GENERALLY A TENTH TO QUARTER INCH. POST-FRONTAL ON
TUESDAY...SHOWERS WILL QUICKLY WIND DOWN IN THE MORNING BUT CLOUDS
WILL BE A LITTLE MORE STUBBORN WITH HIGHS MAINLY LOW-MID 60S.
CLEARING LATE TUESDAY AFTERNOON-EVENING...LEADING TO ANOTHER
CHILLY NIGHT TUESDAY NIGHT. DEPENDING ON HOW DETAILS SHAKE
OUT...ESPECIALLY IN REGARDS TO HOW LONG IT TAKES TO CLEAR...JACK
FROST MAY AGAIN TRY TO VISIT A FEW PATCHY SPOTS BY DAWN WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FOLLOWED HPC GUIDANCE.
NO CHANGE TO THE LONG TERM PATTERN THROUGH THE NEXT SEVERAL DAYS.
A PERSISTENT UL TROF REMAINS FIXED OVER THE EASTERN U.S. WITH A
SURFACE HIGH KEEPING THE WEATHER FAIR AND COOL. THERE IS A
TEMPORARY RELAXATION TO THE FLOW PATTERN HEADING INTO NEXT WEEKEND,
AS THE UPPER ATMOSPHERE JET FLOW GOES ZONAL. THIS WILL ALLOW
TEMPERATURES TO REBOUND BACK TOWARD NORMAL (LOW 70S).
HOWEVER...LOOKING JUST BEYOND THE END OF THE EXTENDED PERIOD, A
STRONG FRONT MOVES THROUGH THE REGION EARLY NEXT WEEK AND THE UL
TROF RETURNS TO ENCOMPASS THE NORTHEAST ONCE AGAIN. AMAZINGLY,
THE MEAN EASTERN TROF HAS BEEN IN PLACE SINCE LAST NOVEMBER.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
00Z UPDATE...
EXPECT VFR CONDITIONS NEXT 24 HOURS AT TERMINALS WITH THE
EXCEPTION OF ELM. IF CLOUDS ARE ABLE TO DIMINISH IN THE NEXT
COUPLE OF HOURS ANOTHER ROUND OF VALLEY FOG IS EXPECTED TO
DEVELOP. MAJORITY OF MODEL GUIDANCE INDICATE MOISTURE WILL REMAIN
AROUND 5KFT THROUGH THE OVERNIGHT BUT FINDING THIS HARD TO BELIEVE
AND HAVE ESSENTIALLY GONE WITH THIN CIRRUS OVERHEAD THROUGH THE
NIGHT. AFTER 05Z AT ELM EXPECT MVFR VSBYS TO DEVELOP AS RAPID
COOLING COMMENCES. LIFR CONDITIONS EXPECTED BETWEEN 08Z AND 14Z
IF SKIES CAN CLEAR.
WINDS LGT/VRB OVERNIGHT THEN LIGHT OUT OF THE SW DURING THE DAY
MONDAY.
OUTLOOK...
MON NGT AND TUE MORNING...MVFR/IFR POSSIBLE IN SHOWERS ESPECIALLY
MONDAY OVERNIGHT.
TUE AFTN TO FRI...VFR EXCEPT FOR MORNING IFR FOG, ESPECIALLY AT ELM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...FROST ADVISORY FROM 2 AM TO 8 AM EDT MONDAY FOR NYZ009-022-036-
037-045-046-057-062.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP
SHORT TERM...MDP
LONG TERM...DJP
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
829 PM EDT SUN SEP 14 2014
.SYNOPSIS...
HIGH PRESSURE WILL RESIDE OVER THE AREA THROUGH MONDAY PROVIDING
DRY WEATHER AND COOL TEMPERATURES. THE FIRST PATCHY FROST IS
POSSIBLE...MAINLY THE UPPER SUSQUEHANNA...WESTERN CATSKILLS...AND
TUG HILL PLATEAU REGIONS OF NEW YORK AS WELL AS STEUBEN COUNTY.
MONDAY NIGHT INTO EARLY TUESDAY MORNING A COLD FRONT WILL PASS
THROUGH THE AREA BRINGING A PERIOD OF SHOWERS. TEMPERATURES WILL
REMAIN ON THE COOL SIDE THE NEXT SEVERAL DAYS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
825 PM UPDATE...
MADE SOME MAJOR ADJUSTMENTS TO THE GRIDS TO INCREASE SKY COVER
THROUGH THE FINGER LAKES/WESTERN SOUTHERN TIER AND LOWER
PROBABILITY OF FROST/FOG HERE WHILE RAISING TEMPS SLIGHTLY. IT APPEARS
THE NAM MODEL WAS CORRECT AS CURRENT 11-3.9 MICRON SATELLITE ALONG
WITH OBS CONFIRM AN EXTENSIVE CLOUD SHIELD AROUND 5KFT OVER THE
WESTERN HALF OF THE CWA. THIS THIN LAYER WAS FIRST SHOWN BY THE
12Z NAM, AND NOW LATER RUNS OF THE 18Z GFS AND LATEST RUC ARE
PICKING UP ON THIS LAYER. IF THE MODELS CONTINUE TO BE CORRECT
THIS CLOUD SHIELD WILL REMAIN IN PLACE, WHILE EXPANDING TO THE
EAST THROUGH THE REST OF THE OVERNIGHT. I WAS TEMPTED TO DROP THE
FROST ADVISORY FOR STEUBEN COUNTY BASED ON THIS BUT WANTED TO WAIT
ANOTHER HOUR OR SO TO SEE IF CLEARING IN WESTERN NY MOVES EAST.
FOR NOW I PUSHED BACK THE TIMING OF BOTH FROST AND FOG FROM THE
BINGHAMTON AREA, WESTWARD, UNTIL CLOSER TO DAYBREAK ITSELF. WILL
REEVALUATE AND TRY TO MAKE A DECISION ON LOWERING ANY PRODUCTS BY
10 PM.
4 PM UPDATE... MAIN ISSUE OF THE NEAR TERM IS THE LIKELY
FIRST FROST FOR SOME PARTS OF THE AREA TONIGHT.
MOST CLOUD COVER WAS EATEN UP BY MIXING DOWN OF DRY AIR.
EXCEPTIONALLY DRY AIR EXISTS JUST ABOVE THE SUBSIDENCE
INVERSION...WITH 12Z BUFFALO SOUNDING DEWPOINTS REACHING AT LEAST
MINUS-45 CELSIUS IN THE 750-600MB LAYER AND MODEL SOUNDINGS IN OUR
AREA EVEN AROUND MINUS-60. PRECIPITABLE WATER VALUES ONLY AROUND A
QUARTER TO THIRD OF AN INCH. SURFACE DEWPOINTS ARE NOW IN UPPER
30S-LOW 40S FAHRENHEIT AND WILL PROBABLY DIP SOME MORE THE NEXT
HOUR OR TWO AS DIURNAL HEATING AND MIXING PEAKS.
SURFACE RIDGE EXTENDED UP THE ONTARIO PENINSULA EARLY THIS
MORNING...AND AWAY FROM THE LAKES TEMPERATURES THERE DIPPED IN
THE 30S BY DAWN WHERE IT STAYED CLEAR. IT SERVES AS A GOOD HINT OF
WHAT WILL OCCUR FOR PARTS OF OUR AREA...WITH THIS VERY DRY AIR
MASS...AND THE SURFACE HIGH PULLING DIRECTLY OVERHEAD TONIGHT.
THERE IS A BIG SPREAD IN GUIDANCE FOR LOWS TONIGHT...MAINLY A
PRODUCT OF DETAILS FOR WHERE SOME CLOUD COVER MAY REMAIN TRAPPED
UNDER THE SUBSIDENCE INVERSION. GUIDANCE IN GENERAL /ESPECIALLY
MAV/ HAS BEEN TOO COOL RECENTLY FOR NIGHTTIME LOWS...YET WHERE IT
STAYS CLEAR RADIATIONAL CONDITIONS WILL BE IDEAL TONIGHT.
DESPITE RH FIELDS IN SOME MODELS DEPICTING LAYER OF MOISTURE AROUND
900-850MB ADVECTING IN FROM THE WEST LATE TONIGHT...POSITION OF
THE SURFACE HIGH AND DRYNESS OF AIR MASS SUGGESTS THAT MOST CLOUDS
/EVEN JUST TO OUR WEST/ WILL ERADICATE WITH LOSS OF DIURNAL
HEATING. WHILE NOT GOING TO THE BOTTOM OF MODEL GUIDANCE...I DID
AT LEAST LEAN THAT DIRECTION BECAUSE OF EXPECTATION IN MAINLY
CLEAR CONDITIONS OVERNIGHT. I HAVE HOISTED FROST ADVISORY FOR
ONEIDA-MADISON-CHENANGO-OTSEGO-DELAWARE-SULLIVAN COUNTIES IN THE
EAST...AS WELL AS STEUBEN COUNTY IN THE WEST...WHERE CONFIDENCE IN
FROST-YIELDING TEMPERATURES IS HIGHEST. THIS ALSO HAPPENS TO BE
CLIMATE-WISE WHERE FROST TENDS TO OCCUR FIRST IN OUR REGION. THE
COLDEST VALLEYS IN EASTERN FRINGES OF OTSEGO-DELAWARE COUNTIES
COULD EVEN GET TO AROUND FREEZING...SUCH AS CHERRY VALLEY AND
ROXBURY.
FOR THE REMAINDER OF THE TWIN TIERS...PATCHY FROST IS STILL
POSSIBLE BUT NOT AS LIKELY NOR WITH AS MUCH COVERAGE COMPARED TO
THE ADVISORY COUNTIES. THE ADVISORY COULD BE AMENDED IN AREA
THOUGH BASED ON TRENDS. HOWEVER...VALLEY FOG IN THE MAIN STEM
RIVER VALLEYS OF THE TWIN TIERS MAY KEEP TEMPERATURES FROM
PLUMMETING TO FROST-PRONE READINGS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
415 PM UPDATE...
THE HIGH PRESSURE RESPONSIBLE FOR FROST CONCERNS TONIGHT...WILL
SHIFT OFF THE EAST COAST MONDAY. THIS WILL INITIATE A
SOUTHWESTERLY MODERATING FLOW...AND TEMPERATURES WARMING TO ABOUT
5-9 DEGREES HIGHER THAN TODAY /SUNDAY/. INITIAL SUNSHINE WILL
YIELD TO INCREASING CLOUDS FROM THE WEST BY LATE AFTERNOON.
MONDAY NIGHT/TUESDAY...UPPER LEVEL TROUGH AND ASSOCIATED COLD
FRONT WILL MOVE THROUGH THE REGION. MODELS ARE IN EXCELLENT
AGREEMENT WITH THIS FEATURE...AND HONED GRIDS IN ACCORDINGLY WITH
HIGH CONFIDENCE POPS /70-80 PCT RANGE/ SWEEPING THROUGH DURING THE
NIGHTTIME HOURS. NO INSTABILITY...SO ONLY SHOWERS
EXPECTED...GENERALLY A TENTH TO QUARTER INCH. POST-FRONTAL ON
TUESDAY...SHOWERS WILL QUICKLY WIND DOWN IN THE MORNING BUT CLOUDS
WILL BE A LITTLE MORE STUBBORN WITH HIGHS MAINLY LOW-MID 60S.
CLEARING LATE TUESDAY AFTERNOON-EVENING...LEADING TO ANOTHER
CHILLY NIGHT TUESDAY NIGHT. DEPENDING ON HOW DETAILS SHAKE
OUT...ESPECIALLY IN REGARDS TO HOW LONG IT TAKES TO CLEAR...JACK
FROST MAY AGAIN TRY TO VISIT A FEW PATCHY SPOTS BY DAWN WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FOLLOWED HPC GUIDANCE.
NO CHANGE TO THE LONG TERM PATTERN THROUGH THE NEXT SEVERAL DAYS.
A PERSISTENT UL TROF REMAINS FIXED OVER THE EASTERN U.S. WITH A
SURFACE HIGH KEEPING THE WEATHER FAIR AND COOL. THERE IS A
TEMPORARY RELAXATION TO THE FLOW PATTERN HEADING INTO NEXT WEEKEND,
AS THE UPPER ATMOSPHERE JET FLOW GOES ZONAL. THIS WILL ALLOW
TEMPERATURES TO REBOUND BACK TOWARD NORMAL (LOW 70S).
HOWEVER...LOOKING JUST BEYOND THE END OF THE EXTENDED PERIOD, A
STRONG FRONT MOVES THROUGH THE REGION EARLY NEXT WEEK AND THE UL
TROF RETURNS TO ENCOMPASS THE NORTHEAST ONCE AGAIN. AMAZINGLY,
THE MEAN EASTERN TROF HAS BEEN IN PLACE SINCE LAST NOVEMBER.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
00Z UPDATE...
EXPECT VFR CONDITIONS NEXT 24 HOURS AT TERMINALS WITH THE
EXCEPTION OF ELM. IF CLOUDS ARE ABLE TO DIMINISH IN THE NEXT
COUPLE OF HOURS ANOTHER ROUND OF VALLEY FOG IS EXPECTED TO
DEVELOP. MAJORITY OF MODEL GUIDANCE INDICATE MOISTURE WILL REMAIN
AROUND 5KFT THROUGH THE OVERNIGHT BUT FINDING THIS HARD TO BELIEVE
AND HAVE ESSENTIALLY GONE WITH THIN CIRRUS OVERHEAD THROUGH THE
NIGHT. AFTER 05Z AT ELM EXPECT MVFR VSBYS TO DEVELOP AS RAPID
COOLING COMMENCES. LIFR CONDITIONS EXPECTED BETWEEN 08Z AND 14Z
IF SKIES CAN CLEAR.
WINDS LGT/VRB OVERNIGHT THEN LIGHT OUT OF THE SW DURING THE DAY
MONDAY.
OUTLOOK...
MON NGT AND TUE MORNING...MVFR/IFR POSSIBLE IN SHOWERS ESPECIALLY
MONDAY OVERNIGHT.
TUE AFTN TO FRI...VFR EXCEPT FOR MORNING IFR FOG, ESPECIALLY AT ELM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...FROST ADVISORY FROM 2 AM TO 8 AM EDT MONDAY FOR NYZ009-022-036-
037-045-046-057-062.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP
SHORT TERM...MDP
LONG TERM...DJP
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
609 AM EDT SAT SEP 13 2014
.SYNOPSIS...
A FLOOD WATCH HAS BEEN ISSUED FOR SATURDAY AS A STALLED COLD
FRONT CONTINUES UNSETTLED WEATHER ACROSS THE AREA. THIS FRONT WILL
REMAIN IN THE VICINITY ON SUNDAY...BEFORE LIFTING BACK NORTH ON
MONDAY...BUT UNSETTLED WEATHER WILL PERSIST. A STRONGER COLD FRONT WILL
CROSS THE AREA ON TUESDAY...BRINGING COOLER AND DRIER WEATHER FOR
THE LATTER HALF OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM SATURDAY...A FLOOD WATCH HAS BEEN POSTED FOR THE
ENTIRE ILM CWA...AND IS IN EFFECT FROM 6 AM THIS MORNING THROUGH 6
AM SUNDAY MORNING.
A STALLED FRONTAL BOUNDARY LYING EAST-WEST NEARLY ALONG THE NC-SC
BORDER WILL LIKELY MEANDER BOTH NORTH AND SOUTH THROUGHOUT THE
NEAR TERM PERIOD. INITIALLY...IT MAY TEMPORARILY PUSH NORTHWARD
DUE TO A VIGOROUS UPPER S/W TROF PUSHING FROM THE GREAT LAKES TO
THE NE STATES TODAY. THEN SETTLING BACK TO THE SOUTH
TONIGHT...WITH MODELS HINTING THAT IT MAY DROP SOUTH OF THE ILM
CWA DURING SUNDAY. PLENTY OF MOISTURE ON EITHER SIDE OF THE
FRONTAL BOUNDARY WITH PWS 2+ INCHES. TO AID PCPN DEVELOPMENT...
FORCING IE. UVVS...WILL BE PROVIDED BY THE SFC FRONT ITSELF...AND
UPPER DYNAMICS IN THE FORM OF A S/W TROF OR VORT...WHICH WILL
FURTHER PROVIDE ADDITIONAL LIFT. NORTH OF THE FRONT WILL OBSERVE
OVERRUNNING TYPE PCPN...IE. STRATIFORM RAINS. HOWEVER...ELEVATED
CONVECTION REMAINS A GOOD POSSIBILITY DUE TO ELEVATED
INSTABILITY...IE. ELEVATED CAPE. SOUTH OF THE FRONT...THE
CHARACTER OF THE PCPN WILL BE MORE CONVECTIVE. WITH THE FA
LOCATED DIRECTLY ON EITHER SIDE OF THIS FRONT...THE CWA WILL THEN
BE SUBJECTED TO PCPN THAT WILL MOVE ACROSS ALREADY SATURATED
GROUNDS...OVER AND OVER AGAIN IE. TRAINING...WITH THE END RESULT
LIKELY FLOODING. THUS...A 24 HR FLOOD WATCH HAS BEEN ISSUED FOR
THE ENTIRE ILM CWA...IN EFFECT FROM 6AM SAT THRU 6AM SUN.
VARIOUS MODEL MOS GUIDANCE INDICATE WIDESPREAD 80S FOR MAX TEMPS
TODAY. DEPENDING ON WHICH SIDE OF THE FRONT ONE IS...THE RANGE
WILL RUN FROM THE LOW 80S NORTHERN PORTIONS OF THE ILM CWA TO MID-
UPPER 80S SOUTHERN PORTIONS OR SOUTH OF THE FRONT. THE WIDESPREAD
CLOUDS AND PCPN MAY FURTHER PREVENT TEMPS FROM CLIMBING...ESPECIALLY
NORTH OF THE FRONT WHERE UPPER 70S IS NOT OUT OF THE QUESTION. THE
COOLER AND DRIER AIR BEHIND THE FRONT REMAINS WELL UPSTREAM...FROM
VIRGINIA AND NORTHWARD. THUS...EVEN IF TEMPORARY FROPA DOES
OCCUR...THE COOLER AND DRIER AIRMASS WILL REMAIN WELL UPSTREAM AND
UNABLE TO INFILTRATE THE REGION DURING THIS PERIOD.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...AN EXPANDING TROUGH AND A PERSISTENT RIDGE
WILL ENGAGE IN BATTLE OVERHEAD THROUGH EARLY NEXT WEEK FOR POSITION
OVER THE CAROLINAS. ALMOST LIKE THE OLD CHILDHOOD GAME OF "RED
ROVER"...EACH FEATURE WILL TRY TO BREAK THROUGH THE OTHER...BUT THE
RIDGE WILL CALL THE TROUGH OVER ONE TOO MANY TIMES...EARNING THE
TROUGH A VICTORY...DISPLACING THE RIDGE BY MONDAY NIGHT. THIS
FORCES THE COLD FRONT BELOW TO BECOME NEARLY STATIONARY SUNDAY AND
MONDAY...WAVERING BACK AND FORTH ACROSS THE AREA...CONTINUING THE
UNSETTLED WEATHER PATTERN.
SURFACE FRONT WILL BE ALONG THE SOUTHERN TIER...OR JUST SOUTH...OF
THE CWA DURING SUNDAY BEFORE SLOWLY LIFTING NORTH AGAIN ON MONDAY.
WHILE INSTABILITY WILL BE LIMITED DUE TO WIDESPREAD CLOUD
COVER...AND UPPER SUPPORT WILL REMAIN MINIMAL...PERSISTENT MOIST
FLOW ATOP THE FRONT COMBINED WITH SURFACE CONVERGENCE ALONG IT (AND
RESIDUAL BOUNDARIES) IN A VERY MOIST COLUMN WILL PRODUCE PERIODS OF
RAIN/TSTMS SUNDAY AND MONDAY. BEST PRECIP CHANCES MAY BE IN THE
SOUTHERN AND WESTERN ZONES SUNDAY AND THIS IS WHERE THE HIGHEST QPF
IS EXPECTED...BUT ALL AREAS WILL LIKELY SEE SHOWERS AND STORMS. A
BRIEF RESPITE IN CONVECTIVE COVERAGE WILL OCCUR WITH LOSS OF HEATING
SUNDAY NIGHT...BEFORE MORE SCATTERED CONVECTION DEVELOPS MONDAY AS
THE FRONT LIFTS TO THE NORTH PRODUCING A BRIEF PERIOD OF WAA AND
SUMMER-LIKE CONVECTION. THIS WILL BE SHORT LIVED HOWEVER...AS THIS
FRONT WILL RETURN BACK TO THE SOUTHEAST AS A COLD FRONT BENEATH A
STRONG VORTICITY IMPULSE MOVING TO THE NORTH EITHER VERY LATE MONDAY
NIGHT...OR JUST BEYOND THIS PERIOD. ANOTHER ROUND OF HEAVIER PRECIP
MAY ACCOMPANY THIS FRONT LATE MONDAY HOWEVER...AND CANNOT AT ANY
TIME FORECAST POP BELOW CHC THROUGH THE PERIOD...WITH HIGHEST
OCCURRING SUNDAY AND THEN AGAIN LATE MONDAY.
HIGHS SUNDAY WILL BE SEVERAL DEGREES BELOW NORMAL THANKS TO
CLOUDS...RAIN...AND COOL NORTHERLY SURFACE FLOW...WITH MAX TEMPS
EXPECTED TO REACH ONLY THE MID 70S FAR NW...TO MID 80S NEAR THE
SOUTH SANTEE RIVER. THE AFOREMENTIONED WAA WILL DRIVE HIGHS INTO THE
LOW/MID 80S CWA-WIDE ON MONDAY. LOWS SUNDAY NIGHT WILL DROP TO
NEAR-NORMAL LEVELS OF THE MID 60S...BUT WILL BE SEVERAL DEGREES
WARMER MONDAY NIGHT AHEAD OF THE NEXT COLD FRONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 SATURDAY...STRONG COLD FRONT WILL PUSH ACROSS THE AREA ON
TUESDAY...USHERING IN COOL CANADIAN AIR FOR MOST OF THE UPCOMING
WEEK.
STRONG VORTICITY IMPULSE SPAWNING A SURFACE LOW PRESSURE WILL BE
RACING EAST WELL NORTH OF THE AREA...BUT A STRONG COLD FRONT BEHIND
THIS WILL DRAG ACROSS THE CWA DURING TUESDAY. A PERIOD OF UNSETTLED
WEATHER IS EXPECTED TUESDAY WITH SHOWERS AND THUNDERSTORMS...BUT
THIS FRONT SHOULD PUSH OFFSHORE BY WEDNESDAY AS A DEEP UPPER TROUGH
DIVES INTO THE EAST. THEREAFTER...GUIDANCE CONTINUES TO DIFFER ON
HOW FAR OFFSHORE THIS FRONT WILL STALL...WITH THE GFS CONTINUING TO
INDICATE THAT IT WILL BE JUST OFFSHORE AND CONTINUE UNSETTLED
CONDITIONS LOCALLY. THE ECMWF...WHICH IS PREFERRED...PUSHES THIS
FRONT WELL OFF THE COAST...WHICH SEEMS ACCURATE BASED OFF THE
STRENGTH OF THE UPPER TROUGH AND SINCE WE HAVE HAD SEVERAL FROPAS
ALREADY THIS YEAR.
USING THE ECMWF AS A GUIDE...WED-FRI WILL FEATURE
DRYING CONDITIONS AND TEMPS AROUND 5 DEGREES BELOW CLIMO THANKS TO
THE CANADIAN ORIGIN OF THE SURFACE HIGH RIDGING DOWN THE COAST. IN
ADDITION...IT APPEARS THE AREA WILL SEE SUNSHINE FOR THE FIRST TIME
IN SEVERAL DAYS BY WEDNESDAY. HOWEVER...MUST NOTE THE PERSISTENCE OF
THE GFS WHICH KEEPS THE FRONT JUST OFF THE COAST AND DEVELOPS A LOW
PRESSURE SYSTEM ALONG THE TAIL END OF THE BOUNDARY. THIS WOULD KEEP
UNSETTLED CONDITIONS ACROSS THE AREA...ESPECIALLY NEAR THE
COAST...WITH MORE WET WEATHER POSSIBLE LATE IN THE WEEK.
WILL KEEP INHERITED LOW-CHC/SCHC POP FOR POTENTIAL...BUT WITH A
SLIGHT DECREASE IN SPECIFIC VALUES TO ACCOUNT FOR THE MUCH DRIER
ECMWF.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...STRATIFORM LIGHT RAIN NEAR KILM SHOULD DISSIPATE
OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE HRRR MODEL SUGGESTS
ISOLATED CONVECTIVE SHOWERS WILL RE-DEVELOP EARLY THIS MORNING
ACROSS THE AREA. EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF
VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR
CONDITIONS WILL DEVELOP THIS MORNING KLBT/KILM/FLO WITH HIGHEST
CONFIDENCE AT KLBT/KILM WHICH IS NEAREST A STATIONARY FRONT.
KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS THIS
MORNING. ANY IFR IMPROVES TO MVFR FAIRLY QUICKLY AFTER SUNRISE WITH
VFR DEVELOPING MID-LATE MORNING. CLOUD COVER SHOULD INITIALLY
INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS
IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE
GREATEST AT KLBT. THIS POTENTIAL SHOULD SHIFT SE-E TO KFLO AND THE
THE COASTAL TERMINALS IN THE LATE AFTERNOON/EARLY EVENING.
EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON
THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 600 AM SATURDAY...WINDS AND TO A LESSER DEGREE SIGNIFICANT
SEAS...WILL BE GOVERNED BY THE MEANDERING FRONTAL BOUNDARY DURING
THIS PERIOD. THIS MEANS...WATERS NORTH OF THE FRONT WILL OBSERVE
NE-E WINDS...AND SOUTH OF THE FRONT WILL SEE SE-SSW WINDS. THE
SFC PG REMAINS LOOSE FOR THE MOST PART RESULTING WITH WIND SPEEDS
AROUND 10 KT. HOWEVER...DEPENDING ON YOUR LOCATION BEHIND THE
FRONT...THE NE-E WINDS THAT OCCUR COULD PRODUCE SPEEDS UP TO 15
KT IF THE SFC PG TIGHTENS ENOUGH. SIGNIFICANT SEAS WILL REMAIN
DOCILE...AROUND 2 FT. THE MINI NE-E INCREASED WINDS BEHIND THE
FRONT COULD PRODUCE SIG. SEAS UP TO 3 FT. AVERAGE PERIODS WILL RUN
4 TO 5 SECONDS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...COLD FRONT SOUTH OF THE WATERS TO START THE
PERIOD WILL REMAIN NEARLY STATIONARY SUNDAY...BEFORE LIFTING BACK TO
THE NORTH AS A WARM FRONT MONDAY. THIS DRIVES NE WINDS ALL SUNDAY
AND INTO MONDAY...BEFORE VEERING TO BECOME S/SE LATE ON MONDAY.
SPEEDS WILL BE 5-10 KTS REGARDLESS OF DIRECTION. A COLD FRONT WILL
APPROACH AT THE VERY END OF THE SHORT TERM WITH WINDS BEGINNING TO
VEER TO THE WEST LATE MONDAY NIGHT. SEAS WILL BE 1-3 FT THROUGH THE
PERIOD...WITH A NE WIND WAVE PREDOMINANT ON SUNDAY...BECOMING
SOUTHERLY DURING MONDAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...THE BEGINNING OF AN EXTENDED PERIOD OF POOR
MARINE CONDITIONS EXPECTED TUESDAY AS A COLD FRONT CROSSES THE
WATERS. ALTHOUGH WINDS TUESDAY WILL BE PRETTY LIGHT...5-10 KTS WITH
SEVERAL VEERING WIND DIRECTIONS...THE CONFUSED SPECTRUM WILL COMBINE
WITH THE SLOWLY AMPLIFYING LONG PERIOD 13-14 SEC SE SWELL ASSOCIATED
WITH TROPICAL STORM EDOUARD MOVING THROUGH THE CENTRAL ATLANTIC...TO
DRIVE INCREASING WAVE HEIGHTS. ADDITIONALLY...A NE SURGE WILL BEGIN
TUESDAY NIGHT BEHIND THIS BOUNDARY...WITH NE WINDS RISING TO AROUND
15 KTS ON WEDNESDAY.
THE COMBINATION OF THE LONG-PERIOD SWELL AND INCREASING WINDS WILL
DRIVE WAVE HEIGHTS FROM 2-4 FT TUESDAY TO 4-6 FT WEDNESDAY...AND A
SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED BEGINNING WEDNESDAY.
ALTHOUGH IT IS BEYOND THIS PERIOD...IT APPEARS WEDNESDAY COULD BE
THE FIRST OF SEVERAL CONSECUTIVE DAYS WITH HEADLINES NEEDED ACROSS
THE COASTAL WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH LATE TONIGHT FOR SCZ017-023-024-032-033-
039-053>056.
NC...FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ087-096-099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DCH/MRR
MARINE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
503 AM EDT SAT SEP 13 2014
.SYNOPSIS...
A FLOOD WATCH HAS BEEN ISSUED FOR SATURDAY AS A STALLED COLD
FRONT CONTINUES UNSETTLED WEATHER ACROSS THE AREA. THIS FRONT WILL
REMAIN IN THE VICINITY ON SUNDAY...BEFORE LIFTING BACK NORTH ON
MONDAY...BUT UNSETTLED WEATHER WILL PERSIST. A STRONGER COLD FRONT WILL
CROSS THE AREA ON TUESDAY...BRINGING COOLER AND DRIER WEATHER FOR
THE LATTER HALF OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM SATURDAY...A FLOOD WATCH HAS BEEN POSTED FOR THE
ENTIRE ILM CWA...IN EFFECT FROM 6 AM THIS MORNING THROUGH 6 AM
SUNDAY MORNING.
A STALLED FRONTAL BOUNDARY LYING EAST-WEST NEARLY ALONG THE NC-SC
BORDER WILL LIKELY MEANDER BOTH NORTH AND SOUTH THROUGHOUT THE
NEAR TERM PERIOD. INITIALLY...IT MAY TEMPORARILY PUSH NORTHWARD
DUE TO A VIGOROUS UPPER S/W TROF PUSHING FROM THE GREAT LAKES TO
THE NE STATES TODAY. THEN SETTLING BACK TO THE SOUTH
TONIGHT...WITH MODELS HINTING THAT IT MAY DROP SOUTH OF THE ILM
CWA EARLY SUNDAY. PLENTY OF MOISTURE ON EITHER SIDE OF THE FRONTAL
BOUNDARY WITH PWS 2+ INCHES. TO AID PCPN DEVELOPMENT...FORCING...
UVVS...WILL BE PROVIDED BY THE SFC FRONT ITSELF...AND UPPER
DYNAMICS IN THE FORM OF A S/W TROF OR VORT...WILL PROVIDE THE
ADDITIONAL LIFT. NORTH OF THE FRONT WILL OBSERVE OVERRUNNING TYPE
PCPN...IE. STRATIFORM RAINS. HOWEVER...ELEVATED CONVECTION REMAINS
A GOOD POSSIBILITY NORTH OF THE FRONT DUE TO THE AVAILABILITY OF
ELEVATED CAPE...ENERGY. SOUTH OF THE FRONT...THE CHARACTER OF THE
PCPN WILL BE MORE CONVECTIVE. THUS...DIRECTLY ON EITHER SIDE OF
THE FRONT...THE FA WILL BE SUBJECT TO PCPN THAT WILL MOVE ACROSS
ALREADY SATURATED GROUNDS...OVER AND OVER AGAIN...WITH THE END
RESULT LIKELY FLOODING. THUS...A 24 HR FLOOD WATCH HAS BEEN
ISSUED FOR THE ENTIRE ILM CWA...IN EFFECT FROM 6AM SAT-6AM SUN.
VARIOUS MODEL MOS GUIDANCE INDICATES WIDESPREAD 80S FOR MAX TEMPS
TODAY. DEPENDING ON WHICH SIDE OF THE FRONT ONE IS...THE RANGE
WILL RUN FROM THE LOW 80S NORTHERN PORTIONS OF THE ILM CWA TO MID-
UPPER 80S SOUTH OF THE FRONT. THE WIDESPREAD CLOUDS AND PCPN MAY
FURTHER PREVENT TEMPS FROM CLIMBING...ESPECIALLY NORTH OF THE
FRONT WHERE UPPER 70S IS NOT OUT OF THE QUESTION. THE COOLER AND
DRIER AIR BEHIND THE FRONT REMAINS WELL UPSTREAM...FROM VIRGINIA
AND NORTHWARD. THUS EVEN IF TEMPORARY FROPA DOES OCCUR...THIS
AIRMASS WILL NOT BE ABLE TO INFILTRATE THE REGION DURING THIS NEAR
TERM PERIOD.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...AN EXPANDING TROUGH AND A PERSISTENT RIDGE
WILL ENGAGE IN BATTLE OVERHEAD THROUGH EARLY NEXT WEEK FOR POSITION
OVER THE CAROLINAS. ALMOST LIKE THE OLD CHILDHOOD GAME OF "RED
ROVER"...EACH FEATURE WILL TRY TO BREAK THROUGH THE OTHER...BUT THE
RIDGE WILL CALL THE TROUGH OVER ONE TOO MANY TIMES...EARNING THE
TROUGH A VICTORY...DISPLACING THE RIDGE BY MONDAY NIGHT. THIS
FORCES THE COLD FRONT BELOW TO BECOME NEARLY STATIONARY SUNDAY AND
MONDAY...WAVERING BACK AND FORTH ACROSS THE AREA...CONTINUING THE
UNSETTLED WEATHER PATTERN.
SURFACE FRONT WILL BE ALONG THE SOUTHERN TIER...OR JUST SOUTH...OF
THE CWA DURING SUNDAY BEFORE SLOWLY LIFTING NORTH AGAIN ON MONDAY.
WHILE INSTABILITY WILL BE LIMITED DUE TO WIDESPREAD CLOUD
COVER...AND UPPER SUPPORT WILL REMAIN MINIMAL...PERSISTENT MOIST
FLOW ATOP THE FRONT COMBINED WITH SURFACE CONVERGENCE ALONG IT (AND
RESIDUAL BOUNDARIES) IN A VERY MOIST COLUMN WILL PRODUCE PERIODS OF
RAIN/TSTMS SUNDAY AND MONDAY. BEST PRECIP CHANCES MAY BE IN THE
SOUTHERN AND WESTERN ZONES SUNDAY AND THIS IS WHERE THE HIGHEST QPF
IS EXPECTED...BUT ALL AREAS WILL LIKELY SEE SHOWERS AND STORMS. A
BRIEF RESPITE IN CONVECTIVE COVERAGE WILL OCCUR WITH LOSS OF HEATING
SUNDAY NIGHT...BEFORE MORE SCATTERED CONVECTION DEVELOPS MONDAY AS
THE FRONT LIFTS TO THE NORTH PRODUCING A BRIEF PERIOD OF WAA AND
SUMMER-LIKE CONVECTION. THIS WILL BE SHORT LIVED HOWEVER...AS THIS
FRONT WILL RETURN BACK TO THE SOUTHEAST AS A COLD FRONT BENEATH A
STRONG VORTICITY IMPULSE MOVING TO THE NORTH EITHER VERY LATE MONDAY
NIGHT...OR JUST BEYOND THIS PERIOD. ANOTHER ROUND OF HEAVIER PRECIP
MAY ACCOMPANY THIS FRONT LATE MONDAY HOWEVER...AND CANNOT AT ANY
TIME FORECAST POP BELOW CHC THROUGH THE PERIOD...WITH HIGHEST
OCCURRING SUNDAY AND THEN AGAIN LATE MONDAY.
HIGHS SUNDAY WILL BE SEVERAL DEGREES BELOW NORMAL THANKS TO
CLOUDS...RAIN...AND COOL NORTHERLY SURFACE FLOW...WITH MAX TEMPS
EXPECTED TO REACH ONLY THE MID 70S FAR NW...TO MID 80S NEAR THE
SOUTH SANTEE RIVER. THE AFOREMENTIONED WAA WILL DRIVE HIGHS INTO THE
LOW/MID 80S CWA-WIDE ON MONDAY. LOWS SUNDAY NIGHT WILL DROP TO
NEAR-NORMAL LEVELS OF THE MID 60S...BUT WILL BE SEVERAL DEGREES
WARMER MONDAY NIGHT AHEAD OF THE NEXT COLD FRONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 SATURDAY...STRONG COLD FRONT WILL PUSH ACROSS THE AREA ON
TUESDAY...USHERING IN COOL CANADIAN AIR FOR MOST OF THE UPCOMING
WEEK.
STRONG VORTICITY IMPULSE SPAWNING A SURFACE LOW PRESSURE WILL BE
RACING EAST WELL NORTH OF THE AREA...BUT A STRONG COLD FRONT BEHIND
THIS WILL DRAG ACROSS THE CWA DURING TUESDAY. A PERIOD OF UNSETTLED
WEATHER IS EXPECTED TUESDAY WITH SHOWERS AND THUNDERSTORMS...BUT
THIS FRONT SHOULD PUSH OFFSHORE BY WEDNESDAY AS A DEEP UPPER TROUGH
DIVES INTO THE EAST. THEREAFTER...GUIDANCE CONTINUES TO DIFFER ON
HOW FAR OFFSHORE THIS FRONT WILL STALL...WITH THE GFS CONTINUING TO
INDICATE THAT IT WILL BE JUST OFFSHORE AND CONTINUE UNSETTLED
CONDITIONS LOCALLY. THE ECMWF...WHICH IS PREFERRED...PUSHES THIS
FRONT WELL OFF THE COAST...WHICH SEEMS ACCURATE BASED OFF THE
STRENGTH OF THE UPPER TROUGH AND SINCE WE HAVE HAD SEVERAL FROPAS
ALREADY THIS YEAR.
USING THE ECMWF AS A GUIDE...WED-FRI WILL FEATURE
DRYING CONDITIONS AND TEMPS AROUND 5 DEGREES BELOW CLIMO THANKS TO
THE CANADIAN ORIGIN OF THE SURFACE HIGH RIDGING DOWN THE COAST. IN
ADDITION...IT APPEARS THE AREA WILL SEE SUNSHINE FOR THE FIRST TIME
IN SEVERAL DAYS BY WEDNESDAY. HOWEVER...MUST NOTE THE PERSISTENCE OF
THE GFS WHICH KEEPS THE FRONT JUST OFF THE COAST AND DEVELOPS A LOW
PRESSURE SYSTEM ALONG THE TAIL END OF THE BOUNDARY. THIS WOULD KEEP
UNSETTLED CONDITIONS ACROSS THE AREA...ESPECIALLY NEAR THE
COAST...WITH MORE WET WEATHER POSSIBLE LATE IN THE WEEK.
WILL KEEP INHERITED LOW-CHC/SCHC POP FOR POTENTIAL...BUT WITH A
SLIGHT DECREASE IN SPECIFIC VALUES TO ACCOUNT FOR THE MUCH DRIER
ECMWF.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...STRATIFORM LIGHT RAIN NEAR KILM SHOULD DISSIPATE
OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE HRRR MODEL SUGGESTS
ISOLATED CONVECTIVE SHOWERS WILL RE-DEVELOP EARLY THIS MORNING
ACROSS THE AREA. EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF
VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR
CONDITIONS WILL DEVELOP THIS MORNING KLBT/KILM/FLO WITH HIGHEST
CONFIDENCE AT KLBT/KILM WHICH IS NEAREST A STATIONARY FRONT.
KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS THIS
MORNING. ANY IFR IMPROVES TO MVFR FAIRLY QUICKLY AFTER SUNRISE WITH
VFR DEVELOPING MID-LATE MORNING. CLOUD COVER SHOULD INITIALLY
INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS
IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE
GREATEST AT KLBT. THIS POTENTIAL SHOULD SHIFT SE-E TO KFLO AND THE
THE COASTAL TERMINALS IN THE LATE AFTERNOON/EARLY EVENING.
EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON
THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 415 AM SATURDAY...WINDS AND TO A LESSER DEGREE SIGNIFICANT
SEAS...WILL BE GOVERNED BY THE MEANDERING FRONTAL BOUNDARY DURING
THIS PERIOD. THIS MEANS...WATERS NORTH OF THE FRONT WILL OBSERVE
NE-E WINDS...AND SOUTH OF THE FRONT THE WATERS WILL SEE SE-SSW
WINDS. THE SFC PG REMAINS LOOSE FOR THE MOST PART RESULTING WITH
WIND SPEEDS AROUND 10 KT. HOWEVER...DEPENDING ON YOUR LOCATION
BEHIND THE FRONT...THE NE-E WINDS THAT OCCUR COULD PRODUCE A
MINI-SURGE WITH SPEEDS UP TO 15 KT. SIGNIFICANT SEAS WILL REMAIN
DOCILE...AROUND 2 FT. THE MINI NE-E SURGE BEHIND THE FRONT COULD
PRODUCE SIG. SEAS UP TO 3 FT. AVERAGE PERIODS WILL RUN 4 TO 5
SECONDS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...COLD FRONT SOUTH OF THE WATERS TO START THE
PERIOD WILL REMAIN NEARLY STATIONARY SUNDAY...BEFORE LIFTING BACK TO
THE NORTH AS A WARM FRONT MONDAY. THIS DRIVES NE WINDS ALL SUNDAY
AND INTO MONDAY...BEFORE VEERING TO BECOME S/SE LATE ON MONDAY.
SPEEDS WILL BE 5-10 KTS REGARDLESS OF DIRECTION. A COLD FRONT WILL
APPROACH AT THE VERY END OF THE SHORT TERM WITH WINDS BEGINNING TO
VEER TO THE WEST LATE MONDAY NIGHT. SEAS WILL BE 1-3 FT THROUGH THE
PERIOD...WITH A NE WIND WAVE PREDOMINANT ON SUNDAY...BECOMING
SOUTHERLY DURING MONDAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...THE BEGINNING OF AN EXTENDED PERIOD OF POOR
MARINE CONDITIONS EXPECTED TUESDAY AS A COLD FRONT CROSSES THE
WATERS. ALTHOUGH WINDS TUESDAY WILL BE PRETTY LIGHT...5-10 KTS WITH
SEVERAL VEERING WIND DIRECTIONS...THE CONFUSED SPECTRUM WILL COMBINE
WITH THE SLOWLY AMPLIFYING LONG PERIOD 13-14 SEC SE SWELL ASSOCIATED
WITH TROPICAL STORM EDOUARD MOVING THROUGH THE CENTRAL ATLANTIC...TO
DRIVE INCREASING WAVE HEIGHTS. ADDITIONALLY...A NE SURGE WILL BEGIN
TUESDAY NIGHT BEHIND THIS BOUNDARY...WITH NE WINDS RISING TO AROUND
15 KTS ON WEDNESDAY.
THE COMBINATION OF THE LONG-PERIOD SWELL AND INCREASING WINDS WILL
DRIVE WAVE HEIGHTS FROM 2-4 FT TUESDAY TO 4-6 FT WEDNESDAY...AND A
SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED BEGINNING WEDNESDAY.
ALTHOUGH IT IS BEYOND THIS PERIOD...IT APPEARS WEDNESDAY COULD BE
THE FIRST OF SEVERAL CONSECUTIVE DAYS WITH HEADLINES NEEDED ACROSS
THE COASTAL WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH LATE TONIGHT FOR SCZ017-023-024-032-033-
039-053>056.
NC...FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ087-096-099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
338 AM EDT SAT SEP 13 2014
.SYNOPSIS...
A FLOOD WATCH HAS BEEN ISSUED FOR SATURDAY AS A STALLED COLD
FRONT CONTINUES UNSETTLED WEATHER ACROSS THE AREA. THIS FRONT WILL
REMAIN IN THE VICINITY ON SUNDAY...BEFORE LIFTING BACK NORTH ON
MONDAY...BUT UNSETTLED WEATHER WILL PERSIST. A STRONGER COLD FRONT WILL
CROSS THE AREA ON TUESDAY...BRINGING COOLER AND DRIER WEATHER FOR
THE LATTER HALF OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10:30 PM FRIDAY...ALTHOUGH MOST OF THE FORECAST AREA THIS
EVENING SAW STRATIFORM RAIN OF GRADUALLY DIMINISHING EXTENT...THE
CAPE FEAR REGION AND WILMINGTON IN PARTICULAR EXPERIENCED A HEAVY
RAIN EVENT COMPLETE WITH LOCALIZED FLOODING. IT APPEARS THAT A
SERIES OF UNFORTUNATELY PLACED BOUNDARY COLLISIONS AND A JUICY
AIR-MASS WERE RESPONSIBLE. LIGHT TO MODERATE RAIN IS STILL
BLANKETING NEW HANOVER COUNTY AND A FLOOD WARNING IS OUT FOR THAT
AREA. GIVEN P/W VALUES IN EXCESS OF 2 INCHES SHOWER ACTIVITY AREA-
WIDE CONTINUES TO BE A POSSIBILITY...ESPECIALLY GIVEN THE
PROXIMITY OF THE COLD FRONT...WHICH SEEMS TO NOW EXTEND ACROSS THE
NORTHERN HALF OF THE FORECAST AREA WITH A FRONTAL WAVE NOW PLACED
OVER THE CAPE FEAR REGION. THIS ALSO NO DOUBT ENHANCED OUR RECENT
BOUT OF HEAVY RAIN.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...AN EXPANDING TROUGH AND A PERSISTENT RIDGE
WILL ENGAGE IN BATTLE OVERHEAD THROUGH EARLY NEXT WEEK FOR POSITION
OVER THE CAROLINAS. ALMOST LIKE THE OLD CHILDHOOD GAME OF "RED
ROVER"...EACH FEATURE WILL TRY TO BREAK THROUGH THE OTHER...BUT THE
RIDGE WILL CALL THE TROUGH OVER ONE TOO MANY TIMES...EARNING THE
TROUGH A VICTORY...DISPLACING THE RIDGE BY MONDAY NIGHT. THIS
FORCES THE COLD FRONT BELOW TO BECOME NEARLY STATIONARY SUNDAY AND
MONDAY...WAVERING BACK AND FORTH ACROSS THE AREA...CONTINUING THE
UNSETTLED WEATHER PATTERN.
SURFACE FRONT WILL BE ALONG THE SOUTHERN TIER...OR JUST SOUTH...OF
THE CWA DURING SUNDAY BEFORE SLOWLY LIFTING NORTH AGAIN ON MONDAY.
WHILE INSTABILITY WILL BE LIMITED DUE TO WIDESPREAD CLOUD
COVER...AND UPPER SUPPORT WILL REMAIN MINIMAL...PERSISTENT MOIST
FLOW ATOP THE FRONT COMBINED WITH SURFACE CONVERGENCE ALONG IT (AND
RESIDUAL BOUNDARIES) IN A VERY MOIST COLUMN WILL PRODUCE PERIODS OF
RAIN/TSTMS SUNDAY AND MONDAY. BEST PRECIP CHANCES MAY BE IN THE
SOUTHERN AND WESTERN ZONES SUNDAY AND THIS IS WHERE THE HIGHEST QPF
IS EXPECTED...BUT ALL AREAS WILL LIKELY SEE SHOWERS AND STORMS. A
BRIEF RESPITE IN CONVECTIVE COVERAGE WILL OCCUR WITH LOSS OF HEATING
SUNDAY NIGHT...BEFORE MORE SCATTERED CONVECTION DEVELOPS MONDAY AS
THE FRONT LIFTS TO THE NORTH PRODUCING A BRIEF PERIOD OF WAA AND
SUMMER-LIKE CONVECTION. THIS WILL BE SHORT LIVED HOWEVER...AS THIS
FRONT WILL RETURN BACK TO THE SOUTHEAST AS A COLD FRONT BENEATH A
STRONG VORTICITY IMPULSE MOVING TO THE NORTH EITHER VERY LATE MONDAY
NIGHT...OR JUST BEYOND THIS PERIOD. ANOTHER ROUND OF HEAVIER PRECIP
MAY ACCOMPANY THIS FRONT LATE MONDAY HOWEVER...AND CANNOT AT ANY
TIME FORECAST POP BELOW CHC THROUGH THE PERIOD...WITH HIGHEST
OCCURRING SUNDAY AND THEN AGAIN LATE MONDAY.
HIGHS SUNDAY WILL BE SEVERAL DEGREES BELOW NORMAL THANKS TO
CLOUDS...RAIN...AND COOL NORTHERLY SURFACE FLOW...WITH MAX TEMPS
EXPECTED TO REACH ONLY THE MID 70S FAR NW...TO MID 80S NEAR THE
SOUTH SANTEE RIVER. THE AFOREMENTIONED WAA WILL DRIVE HIGHS INTO THE
LOW/MID 80S CWA-WIDE ON MONDAY. LOWS SUNDAY NIGHT WILL DROP TO
NEAR-NORMAL LEVELS OF THE MID 60S...BUT WILL BE SEVERAL DEGREES
WARMER MONDAY NIGHT AHEAD OF THE NEXT COLD FRONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 SATURDAY...STRONG COLD FRONT WILL PUSH ACROSS THE AREA ON
TUESDAY...USHERING IN COOL CANADIAN AIR FOR MOST OF THE UPCOMING
WEEK.
STRONG VORTICITY IMPULSE SPAWNING A SURFACE LOW PRESSURE WILL BE
RACING EAST WELL NORTH OF THE AREA...BUT A STRONG COLD FRONT BEHIND
THIS WILL DRAG ACROSS THE CWA DURING TUESDAY. A PERIOD OF UNSETTLED
WEATHER IS EXPECTED TUESDAY WITH SHOWERS AND THUNDERSTORMS...BUT
THIS FRONT SHOULD PUSH OFFSHORE BY WEDNESDAY AS A DEEP UPPER TROUGH
DIVES INTO THE EAST. THEREAFTER...GUIDANCE CONTINUES TO DIFFER ON
HOW FAR OFFSHORE THIS FRONT WILL STALL...WITH THE GFS CONTINUING TO
INDICATE THAT IT WILL BE JUST OFFSHORE AND CONTINUE UNSETTLED
CONDITIONS LOCALLY. THE ECMWF...WHICH IS PREFERRED...PUSHES THIS
FRONT WELL OFF THE COAST...WHICH SEEMS ACCURATE BASED OFF THE
STRENGTH OF THE UPPER TROUGH AND SINCE WE HAVE HAD SEVERAL FROPAS
ALREADY THIS YEAR.
USING THE ECMWF AS A GUIDE...WED-FRI WILL FEATURE
DRYING CONDITIONS AND TEMPS AROUND 5 DEGREES BELOW CLIMO THANKS TO
THE CANADIAN ORIGIN OF THE SURFACE HIGH RIDGING DOWN THE COAST. IN
ADDITION...IT APPEARS THE AREA WILL SEE SUNSHINE FOR THE FIRST TIME
IN SEVERAL DAYS BY WEDNESDAY. HOWEVER...MUST NOTE THE PERSISTENCE OF
THE GFS WHICH KEEPS THE FRONT JUST OFF THE COAST AND DEVELOPS A LOW
PRESSURE SYSTEM ALONG THE TAIL END OF THE BOUNDARY. THIS WOULD KEEP
UNSETTLED CONDITIONS ACROSS THE AREA...ESPECIALLY NEAR THE
COAST...WITH MORE WET WEATHER POSSIBLE LATE IN THE WEEK.
WILL KEEP INHERITED LOW-CHC/SCHC POP FOR POTENTIAL...BUT WITH A
SLIGHT DECREASE IN SPECIFIC VALUES TO ACCOUNT FOR THE MUCH DRIER
ECMWF.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...STRATIFORM LIGHT RAIN NEAR KILM SHOULD DISSIPATE
OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE HRRR MODEL SUGGESTS
ISOLATED CONVECTIVE SHOWERS WILL RE-DEVELOP EARLY THIS MORNING
ACROSS THE AREA. EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF
VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR
CONDITIONS WILL DEVELOP THIS MORNING KLBT/KILM/FLO WITH HIGHEST
CONFIDENCE AT KLBT/KILM WHICH IS NEAREST A STATIONARY FRONT.
KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS THIS
MORNING. ANY IFR IMPROVES TO MVFR FAIRLY QUICKLY AFTER SUNRISE WITH
VFR DEVELOPING MID-LATE MORNING. CLOUD COVER SHOULD INITIALLY
INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS
IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE
GREATEST AT KLBT. THIS POTENTIAL SHOULD SHIFT SE-E TO KFLO AND THE
THE COASTAL TERMINALS IN THE LATE AFTERNOON/EARLY EVENING.
EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON
THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 10:30 PM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT SEAS
CONTINUE ACROSS THE WATERS THIS EVENING. FORECAST REMAINS
UNCHANGED. PREVIOUS DISCUSSION FOLLOWS:
OUTSIDE OF TSTMS NO REAL PROBLEMS EXPECTED ON THE WATERS WITH
LIGHT WINDS OVERALL AND SEAS 2 FEET OR LESS...AS A WEAK FRONTAL
BOUNDARY REMAINS IN VICINITY OF THE AREA. MOST STORMS SHOULD STAY
OVER LAND BUT TONIGHT CELLS MAY BEGIN TO FAVOR THE 0-20 NM WATERS.
SEAS AROUND 2 FEET IN A MIX OF SE WAVES 1-1.5 FT EVERY 8-9 SECONDS
AND S WAVES 0.5-1 FT EVERY 3-4 SECONDS. WITHIN TSTMS WINDS AND
SEAS WILL BE LOCALLY AND SIGNIFICANTLY HIGHER.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...COLD FRONT SOUTH OF THE WATERS TO START THE
PERIOD WILL REMAIN NEARLY STATIONARY SUNDAY...BEFORE LIFTING BACK TO
THE NORTH AS A WARM FRONT MONDAY. THIS DRIVES NE WINDS ALL SUNDAY
AND INTO MONDAY...BEFORE VEERING TO BECOME S/SE LATE ON MONDAY.
SPEEDS WILL BE 5-10 KTS REGARDLESS OF DIRECTION. A COLD FRONT WILL
APPROACH AT THE VERY END OF THE SHORT TERM WITH WINDS BEGINNING TO
VEER TO THE WEST LATE MONDAY NIGHT. SEAS WILL BE 1-3 FT THROUGH THE
PERIOD...WITH A NE WIND WAVE PREDOMINANT ON SUNDAY...BECOMING
SOUTHERLY DURING MONDAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...THE BEGINNING OF AN EXTENDED PERIOD OF POOR
MARINE CONDITIONS EXPECTED TUESDAY AS A COLD FRONT CROSSES THE
WATERS. ALTHOUGH WINDS TUESDAY WILL BE PRETTY LIGHT...5-10 KTS WITH
SEVERAL VEERING WIND DIRECTIONS...THE CONFUSED SPECTRUM WILL COMBINE
WITH THE SLOWLY AMPLIFYING LONG PERIOD 13-14 SEC SE SWELL ASSOCIATED
WITH TROPICAL STORM EDOUARD MOVING THROUGH THE CENTRAL ATLANTIC...TO
DRIVE INCREASING WAVE HEIGHTS. ADDITIONALLY...A NE SURGE WILL BEGIN
TUESDAY NIGHT BEHIND THIS BOUNDARY...WITH NE WINDS RISING TO AROUND
15 KTS ON WEDNESDAY.
THE COMBINATION OF THE LONG-PERIOD SWELL AND INCREASING WINDS WILL
DRIVE WAVE HEIGHTS FROM 2-4 FT TUESDAY TO 4-6 FT WEDNESDAY...AND A
SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED BEGINNING WEDNESDAY.
ALTHOUGH IT IS BEYOND THIS PERIOD...IT APPEARS WEDNESDAY COULD BE
THE FIRST OF SEVERAL CONSECUTIVE DAYS WITH HEADLINES NEEDED ACROSS
THE COASTAL WATERS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH LATE TONIGHT FOR SCZ017-023-024-032-033-
039-053>056.
NC...FLOOD WATCH THROUGH LATE TONIGHT FOR NCZ087-096-099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...DCH/REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DCH/MRR
MARINE...DCH/REK/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
157 AM EDT SAT SEP 13 2014
.SYNOPSIS...
A COLD FRONT WILL BRING UNSETTLED WEATHER THROUGH THE WEEKEND. THE
FRONT WILL WEAKEN ON MONDAY BUT MOISTURE WILL LINGER FOR A
SCATTERING OF SHOWERS ON MONDAY. ANOTHER COLD FRONT SHOULD AFFECT
THE REGION ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 10:30 PM FRIDAY...ALTHOUGH MOST OF THE FORECAST AREA THIS
EVENING SAW STRATIFORM RAIN OF GRADUALLY DIMINISHING EXTENT...THE
CAPE FEAR REGION AND WILMINGTON IN PARTICULAR EXPERIENCED A HEAVY
RAIN EVENT COMPLETE WITH LOCALIZED FLOODING. IT APPEARS THAT A
SERIES OF UNFORTUNATELY PLACED BOUNDARY COLLISIONS AND A JUICY
AIR-MASS WERE RESPONSIBLE. LIGHT TO MODERATE RAIN IS STILL
BLANKETING NEW HANOVER COUNTY AND A FLOOD WARNING IS OUT FOR THAT
AREA. GIVEN P/W VALUES IN EXCESS OF 2 INCHES SHOWER ACTIVITY AREA-
WIDE CONTINUES TO BE A POSSIBILITY...ESPECIALLY GIVEN THE
PROXIMITY OF THE COLD FRONT...WHICH SEEMS TO NOW EXTEND ACROSS THE
NORTHERN HALF OF THE FORECAST AREA WITH A FRONTAL WAVE NOW PLACED
OVER THE CAPE FEAR REGION. THIS ALSO NO DOUBT ENHANCED OUR RECENT
BOUT OF HEAVY RAIN.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...ANOTHER FAIRLY UNSETTLED AFTERNOON IN STORE FOR
THE REGION SATURDAY AS COLD FRONT ENTERS THE COASTAL PLAIN IN THE
PRESENCE OF FAIRLY DEEP TROPICAL MOISTURE. THE MOST WIDESPREAD
COVERAGE WILL BE OVER NWRN ZONES WHICH WILL BE MOST PROXIMAL TO THE
BOUNDARY...PERHAPS RADAR COVERAGE NOT UNLIKE THAT OF THIS AFTERNOON.
WITH A MORE CLOUDY START COMPARED TO TODAY AFTERNOON TEMPERATURES
WILL NOT GROW AS HOT AND TEND TO BE QUITE SEASONABLE. PRECIPITABLE
WATER REMAINS ABOVE 2 INCHES WHILE STORM MOTION REMAINS BELOW 5KT SO
CHANCE FOR HEAVY DOWNPOURS REMAINS INTACT. RAIN CHANCES WILL HAVE A
HARD TIME DIPPING MUCH LOWER THAN LOW END CHANCE RANGE SATURDAY
NIGHT AS THE FRONT MOVES ATOP OF THE FORECAST AREA...ALTHOUGH THE
LOSS OF DAYTIME HEATING SHOULD DIMINISH THEIR INTENSITY AND THE
HEAVY RAIN THREAT. WE WIND UP ON THE OTHER SIDE OF THE FRONT ON
SUNDAY AS IT REMAINS NEARLY STALLED TO OUR SOUTH AND EAST. RAIN
CHANCES WILL BE SHIFTED SOUTH AND EAST ACCORDINGLY AND THE HEAVY
RAIN THREAT WILL BE RELATIVELY MITIGATED. SUNDAY AFTERNOON MAY OFFER
UP A RANGE OF HIGH TEMPERATURES FROM NORTH TO SOUTH FROM THE UPPER
70S TO THE MID 80S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...WEAKENING FRONT STALLED IN THE AREA AT THE START
OF THE PERIOD AND DEEP TROPICAL MOISTURE ENSURE THE FIRST HALF OF
NEXT WEEK REMAIN UNSETTLED. PRECIPITABLE WATER VALUES AROUND 2
INCHES MON AND TUE IN A MODERATELY UNSTABLE AIRMASS SHOULD LEAD TO
SHOWER AND THUNDERSTORM DEVELOPMENT. PLAN TO CARRY CHC POP WITH A
DIURNAL DISTRIBUTION. THE LACK OF FORCING ALOFT SHOULD LEAD TO A
DECREASE IN COVERAGE/ACTIVITY OVERNIGHT BUT DO NOT THINK STORMS WILL
COMPLETELY DISSIPATE. STORM MOTIONS WILL REMAIN 10 KT OR LESS WHICH
WILL MAINTAIN FLOODING POTENTIAL.
A STRONGER COLD FRONT WILL DROP IN FROM THE NORTHWEST MID WEEK. THIS
FRONT HAS A MORE DEFINED TROUGH BEHIND IT WHICH WILL PUSH THE
BOUNDARY SOUTH OF THE AREA BY THE END OF THE WEEK. HOWEVER THERE IS
STILL SOME UNCERTAINTY AS TO HOW FAR SOUTH THIS FRONT MOVES BEFORE
STALLING. ECMWF HAS THE FRONT FARTHER SOUTH...SO DOES WPC...WHILE
THE GFS KEEPS THE FRONT CLOSER TO THE CAROLINAS. BOTH MEDIUM RANGE
SOLUTIONS DEVELOP A WEAK LOW ON THE FRONT AND LIFT IT NORTH...THOUGH
TIMING IS DIFFERENT. ECMWF SOLUTION WOULD PRODUCE SLIGHT CHC TO LOW
CHC OF PRECIP THROUGH THU...MAINLY ALONG THE COAST...WITH DRYING
FRI. GFS IS WETTER WITH HIGH CHC TO LIKELY POP THROUGH THE END OF
THE PERIOD FOR MUCH OF THE FORECAST AREA. PREVIOUS FORECASTS HAVE
BEEN IN LINE WITH THE DRIER ECMWF/WPC SOLUTION AND AT THIS POINT CAN
SEE NO REASON TO MAKE A CHANGE. CONFIDENCE REMAINS LOW SO
SIGNIFICANT CHANGES IN LATER FORECASTS IS STILL A POSSIBILITY.
TEMPERATURE RANGES EARLY IN THE PERIOD WILL BE ON THE NARROW END
WITH CLOUD COVER AND PRECIP KEEPING HIGHS NEAR TO SLIGHTLY BELOW
CLIMO BUT HELPING HOLD LOWS SEVERAL DEGREES ABOVE CLIMO. PASSAGE OF
FRONT MID WEEK WILL BRING BELOW CLIMO TEMPS FOR THE END OF THE WEEK.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...STRATIFORM LIGHT RAIN NEAR KILM SHOULD DISSIPATE
OVER THE NEXT SEVERAL HOURS...ALTHOUGH THE HRRR MODEL SUGGESTS
ISOLATED CONVECTIVE SHOWERS WILL RE-DEVELOP EARLY THIS MORNING
ACROSS THE AREA. EXPECT THICK MID/UPPER CLOUD COVER THROUGH THE TAF
VALID PERIOD WITH COPIOUS AMOUNTS OF LOW LEVEL MOISTURE. IFR/LIFR
CONDITIONS WILL DEVELOP THIS MORNING KLBT/KILM/FLO WITH HIGHEST
CONFIDENCE AT KLBT/KILM WHICH IS NEAREST A STATIONARY FRONT.
KCRE/KMYR ARE MORE LIKELY TO EXPERIENCE MVFR CONDITIONS THIS
MORNING. ANY IFR IMPROVES TO MVFR FAIRLY QUICKLY AFTER SUNRISE WITH
VFR DEVELOPING MID-LATE MORNING. CLOUD COVER SHOULD INITIALLY
INHIBIT HEATING AND LIFT SO THINK WORSE CASE VCSH COASTAL TERMINALS
IN THE MORNING HOURS. BY AFTERNOON THUNDERSTORM POTENTIAL SHOULD BE
GREATEST AT KLBT. THIS POTENTIAL SHOULD SHIFT SE-E TO KFLO AND THE
THE COASTAL TERMINALS IN THE LATE AFTERNOON/EARLY EVENING.
EXTENDED OUTLOOK...A CHANCE OF SHOWERS WITH MAINLY AFTERNOON
THUNDERSTORMS/TEMPO MVFR THROUGH TUESDAY.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 10:30 PM FRIDAY...LIGHT AND VARIABLE WINDS WITH 2 FT SEAS
CONTINUE ACROSS THE WATERS THIS EVENING. FORECAST REMAINS
UNCHANGED. PREVIOUS DISCUSSION FOLLOWS:
OUTSIDE OF TSTMS NO REAL PROBLEMS EXPECTED ON THE WATERS WITH
LIGHT WINDS OVERALL AND SEAS 2 FEET OR LESS...AS A WEAK FRONTAL
BOUNDARY REMAINS IN VICINITY OF THE AREA. MOST STORMS SHOULD STAY
OVER LAND BUT TONIGHT CELLS MAY BEGIN TO FAVOR THE 0-20 NM WATERS.
SEAS AROUND 2 FEET IN A MIX OF SE WAVES 1-1.5 FT EVERY 8-9 SECONDS
AND S WAVES 0.5-1 FT EVERY 3-4 SECONDS. WITHIN TSTMS WINDS AND
SEAS WILL BE LOCALLY AND SIGNIFICANTLY HIGHER.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...PREFRONTAL SOUTHWESTERLY FLOW ON SATURDAY SHOULD
REMAIN AT 10 KT PREVENTING SEAS FROM ATTAINING HEIGHTS MORE THAN 2
FT. LATE SATURDAY NIGHT AS THE FRONT DRAWS NEAR THE COAST THERE MAY
BE A GENTLE BACKING OF THE FLOW FOLLOWED BY A MORE PRECIPITOUS VEER
ON SUNDAY ASSOCIATED WITH ACTUAL FROPA. THE FRONT WILL NOT MOVE VERY
FAR TO OUR SOUTH BEFORE STALLING WHICH PRECLUDES MUCH OF A SURGE OF
HIGH PRESSURE AND THUS ANY HIGHER WINDS. THUS THE VEER TO ENE FLOW
APPEARS TO BE THE MAIN EFFECT OF THE FROPA AS WIND SPEEDS AND WAVE
HEIGHTS REMAIN UNCHANGED...ALTHOUGH WAVE PERIODS MAY SHORTEN UP A
BIT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...DIMINISHING NORTHERLY SURGE AT THE START OF THE
PERIOD WILL LEAVE LIGHT AND VARIABLE WINDS OVER THE WATERS FOR MUCH
OF MON AND TUE GIVEN PROXIMITY TO THE STALLED FRONT. ANOTHER COLD
FRONT WILL DROP IN FROM THE NORTHWEST DURING THE SECOND HALF OF THE
PERIOD. THIS FRONT IS MORE DEFINED AND SHOULD BE ACCOMPANIED BY A
STRONGER NORTHERLY SURGE LATER WED INTO WED NIGHT. WINDS WILL
APPROACH A SOLID 15 KT WED NIGHT WITH GUSTS AROUND 20 KT POSSIBLE.
SEAS 2 TO 3 FT FOR MUCH OF THE PERIOD WILL BUILD AS HIGH AS 5 FT AS
THE PERIOD ENDS DUE TO THE PROLONGED AND STEADILY INCREASING NATURE
OF THE NORTHERLY SURGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 3 AM EDT EARLY THIS MORNING FOR
NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...MJC/REK
SHORT TERM...MBB
LONG TERM...III
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
338 PM CDT SAT SEP 13 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 329 PM CDT SAT SEP 13 2014
COLD FRONT MOVING THROUGH THE REGION WILL GENERATE WIDELY
SCATTERED SHOWERS ACROSS NORTHERN NORTH DAKOTA THIS AFTERNOON AND
EARLY THIS EVENING. GENERALLY FOLLOWED THE HRRR IN AREA AND TIMING
OF THE SHOWERS. SHOWERS WILL END BEFORE MIDNIGHT. SKIES WILL CLEAR
WITH OVERNIGHT LOWS IN THE LOWER TO MIDDLE 30S WEST. ISSUED A
FROST ADVISORY ACROSS THE WEST...GENERALLY WEST OF THE MISSOURI
RIVER AND WEST OF MINOT. SURFACE HIGH PRESSURE WILL COVER THE
REGION SUNDAY AND ANOTHER ROUND OF PATCH FROST IS POSSIBLE SUNDAY
NIGHT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 329 PM CDT SAT SEP 13 2014
THE EXTENDED PERIOD WILL REMAIN LARGELY DRY THROUGH THURSDAY AS A
LARGE UPPER LOW ACROSS EASTERN CANADA SLOWLY MOVES EAST. AS THIS
HAPPENS BROAD RIDGING WILL DEVELOP OVER THE CENTRAL AND NORTHERN
PLAINS. THIS WILL ALLOW A SLOW WARMING TREND THROUGH THE MIDDLE TO
AND OF NEXT WEEK. BY NEXT WEEKEND A COLD FRONT WILL MOVE THROUGH
BRINGING SCATTERED THUNDERSTORMS TO THE REGION THURSDAY NIGHT INTO
FRIDAY NIGHT.
FOR TEMPERATURES...SUNDAY NIGHT COULD SEE SOME SCATTERED FROST
BEFORE THE WARMUP BEGINS. OTHER THAN THAT...MORNING LOWS WILL B IN
THE 40S TO MIDDLE 50S WITH HIGHS IN THE 60S MONDAY AND THE 70S TO
AROUND 80 TUESDAY THROUGH SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 329 PM CDT SAT SEP 13 2014
COLD FRONT PROGRESSING THROUGH THE REGION. WHILE VFR CONDITIONS
ARE FORECAST THROUGH THE PERIOD...CLOUDS AS LOW AS 3 THOUSAND AGL
EXPECTED KDIK-KISN-KMOT AS THE COOLER AIR MOVES IN. SCATTERED
SHOWERS EXPECTED ACROSS THE NORTH UNTIL 03Z.BUT TOO WIDELY
SCATTERED TO INCLUDE IN THE TAF AT THIS TIME.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 3 AM CDT /2 AM MDT/ TO 9 AM CDT /8 AM MDT/
SUNDAY FOR NDZ001-002-009-010-017>021-031>034-040>045.
&&
$$
SHORT TERM...WAA
LONG TERM...WAA
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
109 PM CDT SAT SEP 13 2014
.UPDATE...
ISSUED AT 101 PM CDT SAT SEP 13 2014
NO CHANGES NEEDED. FRONT TO REACH DVL 21Z OR SO WITH PSBL SHOWER
THEN A BIT BETTER CHC INTO THE NRN-CNTRL RRV 01-02Z.
UPDATE ISSUED AT 1017 AM CDT SAT SEP 13 2014
FCST GOING AS PLANNED...HIGH AND MID LEVEL CLOUDS OVER THE FCST
AREA IN AREA OF 850 MB WARM ADVECTION. 925 MB WINDS IN THE 25-30
KT RANGE 15-21Z WILL START TO GET TO THE SURFACE AS TEMPS WARM.
MAIN SFC LOW WEST OF BRANDON MANITOBA...MOVING EAST. RAIN SHOWERS
MOSTLY ASSOC WITH UPPER LOW JUST NORTH OF REGINA SK AND MODELS
CONTINUE TO KEEP MOST OF THE PRECIP WITH THIS EVENT JUST NORTH OF
THE BORDER TONIGHT THEN OVER LAKE OF THE WOODS REGION AND ONTARIO
SUNDAY. WILL CONTINUE WITH LOWER POPS SOUTH OF LOW WITH HRRR
SHOWING SOME SHOWERS LATER AFTN-EVE MOVING INTO NE ND/NRN RRV.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 338 AM CDT SAT SEP 13 2014
NO CHANGE IN THE CURRENT FROST ADVISORY...ALTHOUGH A FEW LOCATIONS
OVER THE FAR EASTERN CWFA ARE IN THE MID 20S AT 08Z. WITH CIRRUS
INCREASING AND RETURN FLOW DEVELOPING DO NOT EXPECT TEMPERATURES
TO FALL MORE THAN 1 OR 2 DEGREES IN THE KVWU...KBJI...KBDO AND
KADC AREAS.
TODAY WILL BE A TRANSITION DAY. AS THE UNSEASONALLY COLD HIGH
MOVES SOUTH...LOW PRESSURE INTENSIFIES OVER SASKATCHEWAN SOUTH
WINDS WILL INCREASE BY MID DAY. THE MODELS INITIALIZED WELL AND
WILL FOLLOW THE HIGHER RESOLUTION HRRR AND NAM12 TODAY...BLENDING
THE NAM/GFS FOR TONIGHT INTO SUNDAY MORNING. TIMING OF WARM
ADVECTION PRECIPITATION AHEAD OF WELL DEFINED UPPER WAVE OVER
FAR NORTH-CENTRAL MONTANA SIMILAR TO PREVIOUS FORECAST REACHING THE
DEVILS LAKE BASIN AROUND 18Z AND SPREADING EAST. NAM/GFS HAVE
SMALL AREA OF 0C SHOWALTERS AND SOME ML CAPE BUT WILL NOT MENTION
TSRA ATTM. WITH WELL MIXED LAYER TO AROUND 800 MB...35 KTS AT 850
IN THE NAM AND NEAR 30 KTS IN THE GFS TRANSLATE TO GUSTS CLOSE TO
30 KTS POSSIBLE. MOS HAS 27 KTS AND WILL FOLLOW THAT FOR THE 18Z -
00Z PERIOD.
SECOND STRONGER SHORTWAVE...DROPPING ALONG THE ALBERTA/SASKATCHEWAN
BORDER IS FORECAST TO BE NEAR KDVL AT 06Z TONIGHT. SURFACE LOW
SLOWS AND WRAP AROUND SHRA SPREADING OVER THE EAST HALF OF THE
CWFA INTO SUNDAY MORNING.
THE COLUMN COOLS AND DRIES MOST AREAS SUNDAY...WITH LINGERING SHRA
OVER THE NORTHEAST PORTION OF THE CWFA...WITH STRONGER MID-UPPER
CAA ALONG SHEAR AXIS AND ENTRANCE REGION OF UPPER JET. THIS
QUICKLY MOVES OUT WITH PRECIPITATION ENDING BY 00Z MONDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 AM CDT SAT SEP 13 2014
WINDS DIMINISH AND SKIES CLEAR AS HIGH PRESSURE MOVES ACROSS THE
CWFA. LOWS WILL FALL BACK INTO THE LOW TO MID 30S...BUT EXPECT
SUFFICIENT MIXING AT THIS TIME TO KEEP FROST/FREEZE RISK MINIMAL
FOR MONDAY MORNING. LIGHT SOUTHWEST WINDS AND PLENTIFUL SUNSHINE WILL
ALLOW MODEST WARM-UP MONDAY TO NEAR MID SEPTEMBER NORMALS. RISING
HEIGHTS AND CONTINUED WESTERLY FLOW WILL MAKE FOR A MAINLY CLEAR
AND MILD MONDAY NIGHT.
TUESDAY TO FRIDAY...CONFLUENT NW FLOW ALOFT FOR MUCH OF THE WEEK
WITH A QUICK TRANSITIONING PERIOD THURSDAY INTO FRIDAY. AS A RESULT
DRY CONDITIONS EXPECTED WITH MODERATING TEMPS AS THICKNESSES
INCREASE WITH RIDGING OVER THE FA BY THURSDAY. BY THURSDAY PM OR
FRIDAY DEPENDING ON MODEL OF CHOICE...500MB SW FLOW AND 850MB LLJ
BRING INSTABILITY INTO FA FROM WEST TO EAST. WENT WITH A MOSTLY
SHRA AND ISO THUNDER FOR WX GRIDS AS SHOWALTERS DO BECOME NEGATIVE
AHEAD OF THE SFC TROUGH EXPECTED TO IMPACT THE NORTHERN PLAINS
TOWARDS THE END OF THE WEEK. TEMPERATURES ABOVE NORMAL THROUGH THE
WEEK CAN BE EXPECTED WITH SOME HUMIDITY POSSIBLE BY WEEKS END.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 101 PM CDT SAT SEP 13 2014
VFR CIGS WITH SOUTHERLY WINDS SWITCHING TO THE WEST THIS EVENING
AS A FRONT MOVES ACROSS THE NORTHERN TIER OF THE CONUS. WILL SEE
SOME SHRA MOVE ACROSS THE NORTHERN VALLEY AND INTO NW MN IN THE
EARLY AFTN...AND WILL MENTION AT GFK AND TVF. NOT AS CONFIDENT AT
BJI WHERE SHRA MAY PETER OUT BEFORE MAKING IT THAT FAR EAST...BUT
WILL HOLD MID LEVEL CIGS IN THROUGH THE 18Z PD AS WRAP AROUND
MOISTURE SHOULD IMPACT BJI THE LONGEST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...EWENS
LONG TERM...JK/EWENS
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1247 PM CDT SAT SEP 13 2014
.UPDATE...
ISSUED AT 1235 PM CDT SAT SEP 13 2014
COLD FRONT PROGRESSING THROUGH THE REGION EARLY THIS AFTERNOON. SO
FAR SHOWERS ARE ONLY VERY WIDELY SCATTERED ACROSS THE NORTH WITH
MORE SHOWERS UPSTREAM IN SASK. WILL MAINTAIN SLIGHT CHANCE
THROUGH THE AFTERNOON NORTH. ONLY UPDATE WILL BE FOR WINDS...RAISED A
BIT WEST TO 20 TO 30 MPH.
UPDATE ISSUED AT 845 AM CDT SAT SEP 13 2014
CANCELLED THE FROST ADVISORY. REFINED THE CLOUD COVER BASED ON
SATELLITE TRENDS AS HIGH CLOUDS ARE FADING A BIT CENTRAL. UPPED
THE WINDS A BIT AFTER THE FRONTAL PASSAGE.
UPDATE ISSUED AT 633 AM CDT SAT SEP 13 2014
LATEST SURFACE ANALYSIS SHOWS SURFACE CDFNT OVER WESTERN NORTH
DAKOTA WITH STRATOCU DECK DROPPING SOUTH FROM ALBERTA AND WESTERN
SASKATCHEWAN INTO NORTH CENTRAL MONTANA. LATEST 10 UTC RAP LOOKS
TO BE A LITTLE TOO QUICK IN BRINGING HIGHER 850 MB MOISTURE INTO
WESTERN NORTH DAKOTA...BUT BASED ON LATEST SATELLITE AND
OBSERVATIONS HAVE BUMPED UP SKY COVER ACROSS THE WEST LATER THIS
MORNING AND OVER THE NORTH AND CENTRAL THIS AFTERNOON. NO CHANGES
TO POPS AT THIS TIME...KEEPING SLIGHT CHANCE MAINLY NORTH OF THE
I94 CORRIDOR...WHICH IS IN AGREEMENT WITH LATEST RAP/HRRR
ITERATIONS. CURRENT TEMPERATURES REMAIN IN THE MID 30S ACROSS MOST
OF THE FROST ADVISORY AREA...THUS WILL KEEP IT GOING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CDT SAT SEP 13 2014
EARLY MORNING WATER VAPOR IMAGERY SHOWED AN UPPER WAVE MOVING
SOUTHEAST ACROSS SOUTHERN SASKATCHEWAN WHICH WAS PUSHING A COLD
FRONT TOWARDS THE STATE. THE UPPER WAVE IS EXPECTED TO MOVE
QUICKLY ACROSS THE NORTHERN PLAINS TODAY ALONG WITH THE COLD
FRONT. THE MAIN QUESTION WILL BE HOW FAR SOUTH TO BRING A CHANCE
OF RAIN SHOWERS TODAY AS THE WAVE / COLD FRONT PASS. THERE ARE A
WIDE VARIETY OF MODEL SOLUTIONS WITH DIFFERING PLACEMENT...BUT DUE
TO THE STRENGTH OF THE WAVE OPTED TO FAVOR THE MODELS WHICH BRING
THE RAIN CHANCES FARTHER SOUTH INTO NORTH DAKOTA. IN FACT...AM A
BIT CONCERNED WE MAY NOT HAVE TAKEN THE POPS FAR ENOUGH SOUTH IF
THE 4.0KM WRF NMM VERIFIES. A POTENTIAL LIMITING FACTOR COULD BE
DRY AIR IN THE LOW LEVELS...SO KEPT THE RAIN CHANCES GENERALLY
NORTH OF I-94.
THE NEXT CONCERN SURROUNDS THE FROST ADVISORY WHICH IS IN PLACE
ACROSS ROUGHLY THE SOUTHERN HALF OF THE FORECAST AREA THIS
MORNING. PASSING HIGH CLOUDS AHEAD OF THE UPPER WAVE HAVE
HELPED TEMPERATURES RISE A FEW DEGREES OVERNIGHT IN SOME
LOCATIONS...BUT READINGS IN THE ADVISORY AREA REMAIN IN THE 30S
TO LOWER 40S. THE HIGH CLOUDS ARE RATHER THIN ON THEIR SOUTHERN
EDGE...AND WITH GFS LAMP GUIDANCE STILL SUPPORTING FALLING
TEMPERATURES AT MOST LOCATIONS...WILL KEEP THE ADVISORY IN PLACE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 308 AM CDT SAT SEP 13 2014
THE LONG TERM PERIOD BEGINNING SUNDAY LOOKS RATHER TRANQUIL THROUGH
MID WEEK. PATCHY MORNING FROST CAN NOT BE RULED OUT EARLY SUNDAY AND
MONDAY MORNINGS WITH SURFACE HIGH PRESSURE OVER THE AREA AND A
NORTHWEST UPPER FLOW KEEPING SEASONABLY COOL AIR OVER THE NORTHERN
PLAINS. OTHERWISE IT LOOKS DRY WITH A WARMING TREND THROUGH MIDWEEK.
MORNING LOWS IN THE MID 30S TO LOWER 40S...AND DAYTIME HIGHS IN
THE UPPER 50S AND 60S SUNDAY AND MONDAY...WILL WARM TO THE MID 40S
TO MID 50S FOR LOWS...AND 70S FOR HIGHS BY MID TO LATE WEEK.
A PROGRESSIVE UPPER LEVEL TROUGH MOVING ONTO THE WESTERN U.S. COAST
ON THURSDAY WILL APPROACH THE NORTHERN PLAINS BY LATE FRIDAY.
THERE ARE DIFFERENCES IN THE HANDLING OF THIS WAVE BETWEEN THE GFS
AND ECMWF MODELS BUT BOTH BRING INCREASING MOISTURE AND A SMALL
CHANCE OF SHOWERS AND ISOLATED THUNDER LATE THURSDAY INTO EARLY
FRIDAY...WITH THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY
AND FRIDAY NIGHT AND POSSIBLY LINGERING IN THE EAST EARLY
SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1235 PM CDT SAT SEP 13 2014
COLD FRONT PROGRESSING THROUGH THE REGION. WHILE VFR CONDITIONS
ARE FORECAST THROUGH THE PERIOD...CLOUDS WILL LOWER TO 3 TO 5
THOUSAND AGL AS THE COOLER AIR MOVES IN FROM. SCATTERED SHOWERS
EXPECTED ACROSS THE NORTH UNTIL 00Z. TO WIDELY SCATTERED TO
INCLUDE IN THE TAF AT THIS TIME.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CK
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1021 AM CDT SAT SEP 13 2014
.UPDATE...
ISSUED AT 1017 AM CDT SAT SEP 13 2014
FCST GOING AS PLANNED...HIGH AND MID LEVEL CLOUDS OVER THE FCST
AREA IN AREA OF 850 MB WARM ADVECTION. 925 MB WINDS IN THE 25-30
KT RANGE 15-21Z WILL START TO GET TO THE SURFACE AS TEMPS WARM.
MAIN SFC LOW WEST OF BRANDON MANITOBA...MOVING EAST. RAIN SHOWERS
MOSTLY ASSOC WITH UPPER LOW JUST NORTH OF REGINA SK AND MODELS
CONTINUE TO KEEP MOST OF THE PRECIP WITH THIS EVENT JUST NORTH OF
THE BORDER TONIGHT THEN OVER LAKE OF THE WOODS REGION AND ONTARIO
SUNDAY. WILL CONTINUE WITH LOWER POPS SOUTH OF LOW WITH HRRR
SHOWING SOME SHOWERS LATER AFTN-EVE MOVING INTO NE ND/NRN RRV.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 338 AM CDT SAT SEP 13 2014
NO CHANGE IN THE CURRENT FROST ADVISORY...ALTHOUGH A FEW LOCATIONS
OVER THE FAR EASTERN CWFA ARE IN THE MID 20S AT 08Z. WITH CIRRUS
INCREASING AND RETURN FLOW DEVELOPING DO NOT EXPECT TEMPERATURES
TO FALL MORE THAN 1 OR 2 DEGREES IN THE KVWU...KBJI...KBDO AND
KADC AREAS.
TODAY WILL BE A TRANSITION DAY. AS THE UNSEASONALLY COLD HIGH
MOVES SOUTH...LOW PRESSURE INTENSIFIES OVER SASKATCHEWAN SOUTH
WINDS WILL INCREASE BY MID DAY. THE MODELS INITIALIZED WELL AND
WILL FOLLOW THE HIGHER RESOLUTION HRRR AND NAM12 TODAY...BLENDING
THE NAM/GFS FOR TONIGHT INTO SUNDAY MORNING. TIMING OF WARM
ADVECTION PRECIPITATION AHEAD OF WELL DEFINED UPPER WAVE OVER
FAR NORTH-CENTRAL MONTANA SIMILAR TO PREVIOUS FORECAST REACHING THE
DEVILS LAKE BASIN AROUND 18Z AND SPREADING EAST. NAM/GFS HAVE
SMALL AREA OF 0C SHOWALTERS AND SOME ML CAPE BUT WILL NOT MENTION
TSRA ATTM. WITH WELL MIXED LAYER TO AROUND 800 MB...35 KTS AT 850
IN THE NAM AND NEAR 30 KTS IN THE GFS TRANSLATE TO GUSTS CLOSE TO
30 KTS POSSIBLE. MOS HAS 27 KTS AND WILL FOLLOW THAT FOR THE 18Z -
00Z PERIOD.
SECOND STRONGER SHORTWAVE...DROPPING ALONG THE ALBERTA/SASKATCHEWAN
BORDER IS FORECAST TO BE NEAR KDVL AT 06Z TONIGHT. SURFACE LOW
SLOWS AND WRAP AROUND SHRA SPREADING OVER THE EAST HALF OF THE
CWFA INTO SUNDAY MORNING.
THE COLUMN COOLS AND DRIES MOST AREAS SUNDAY...WITH LINGERING SHRA
OVER THE NORTHEAST PORTION OF THE CWFA...WITH STRONGER MID-UPPER
CAA ALONG SHEAR AXIS AND ENTRANCE REGION OF UPPER JET. THIS
QUICKLY MOVES OUT WITH PRECIPITATION ENDING BY 00Z MONDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 AM CDT SAT SEP 13 2014
WINDS DIMINISH AND SKIES CLEAR AS HIGH PRESSURE MOVES ACROSS THE
CWFA. LOWS WILL FALL BACK INTO THE LOW TO MID 30S...BUT EXPECT
SUFFICIENT MIXING AT THIS TIME TO KEEP FROST/FREEZE RISK MINIMAL
FOR MONDAY MORNING. LIGHT SOUTHWEST WINDS AND PLENTIFUL SUNSHINE WILL
ALLOW MODEST WARM-UP MONDAY TO NEAR MID SEPTEMBER NORMALS. RISING
HEIGHTS AND CONTINUED WESTERLY FLOW WILL MAKE FOR A MAINLY CLEAR
AND MILD MONDAY NIGHT.
TUESDAY TO FRIDAY...CONFLUENT NW FLOW ALOFT FOR MUCH OF THE WEEK
WITH A QUICK TRANSITIONING PERIOD THURSDAY INTO FRIDAY. AS A RESULT
DRY CONDITIONS EXPECTED WITH MODERATING TEMPS AS THICKNESSES
INCREASE WITH RIDGING OVER THE FA BY THURSDAY. BY THURSDAY PM OR
FRIDAY DEPENDING ON MODEL OF CHOICE...500MB SW FLOW AND 850MB LLJ
BRING INSTABILITY INTO FA FROM WEST TO EAST. WENT WITH A MOSTLY
SHRA AND ISO THUNDER FOR WX GRIDS AS SHOWALTERS DO BECOME NEGATIVE
AHEAD OF THE SFC TROUGH EXPECTED TO IMPACT THE NORTHERN PLAINS
TOWARDS THE END OF THE WEEK. TEMPERATURES ABOVE NORMAL THROUGH THE
WEEK CAN BE EXPECTED WITH SOME HUMIDITY POSSIBLE BY WEEKS END.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 1133 AM CDT SAT SEP 13 2014
VFR CIG/VSBY THROUGH THIS PERIOD...WITH INCRG SOUTH WINDS. BY 16Z
EXPECT G25KTS MOST TAF SITES. WSHFT FCST AT KDVL ABT 22Z. WDLY SCT
-SHRA PSBL AFT 18Z...BUT INSUFFICIENT CONFIDENCE TO PUT IN TAF
ATTM. -SHRA MOST LIKELY KDVL...KGFK...KTVF LINE AFT 21Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...EWENS
LONG TERM...JK/EWENS
AVIATION...EWENS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
854 AM CDT SAT SEP 13 2014
.UPDATE...
ISSUED AT 845 AM CDT SAT SEP 13 2014
CANCELLED THE FROST ADVISORY. REFINED THE CLOUD COVER BASED ON
SATELLITE TRENDS AS HIGH CLOUDS ARE FADING A BIT CENTRAL. UPPED
THE WINDS A BIT AFTER THE FRONTAL PASSAGE.
UPDATE ISSUED AT 633 AM CDT SAT SEP 13 2014
LATEST SURFACE ANALYSIS SHOWS SURFACE CDFNT OVER WESTERN NORTH
DAKOTA WITH STRATOCU DECK DROPPING SOUTH FROM ALBERTA AND WESTERN
SASKATCHEWAN INTO NORTH CENTRAL MONTANA. LATEST 10 UTC RAP LOOKS
TO BE A LITTLE TOO QUICK IN BRINGING HIGHER 850 MB MOISTURE INTO
WESTERN NORTH DAKOTA...BUT BASED ON LATEST SATELLITE AND
OBSERVATIONS HAVE BUMPED UP SKY COVER ACROSS THE WEST LATER THIS
MORNING AND OVER THE NORTH AND CENTRAL THIS AFTERNOON. NO CHANGES
TO POPS AT THIS TIME...KEEPING SLIGHT CHANCE MAINLY NORTH OF THE
I94 CORRIDOR...WHICH IS IN AGREEMENT WITH LATEST RAP/HRRR
ITERATIONS. CURRENT TEMPERATURES REMAIN IN THE MID 30S ACROSS MOST
OF THE FROST ADVISORY AREA...THUS WILL KEEP IT GOING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CDT SAT SEP 13 2014
EARLY MORNING WATER VAPOR IMAGERY SHOWED AN UPPER WAVE MOVING
SOUTHEAST ACROSS SOUTHERN SASKATCHEWAN WHICH WAS PUSHING A COLD
FRONT TOWARDS THE STATE. THE UPPER WAVE IS EXPECTED TO MOVE
QUICKLY ACROSS THE NORTHERN PLAINS TODAY ALONG WITH THE COLD
FRONT. THE MAIN QUESTION WILL BE HOW FAR SOUTH TO BRING A CHANCE
OF RAIN SHOWERS TODAY AS THE WAVE / COLD FRONT PASS. THERE ARE A
WIDE VARIETY OF MODEL SOLUTIONS WITH DIFFERING PLACEMENT...BUT DUE
TO THE STRENGTH OF THE WAVE OPTED TO FAVOR THE MODELS WHICH BRING
THE RAIN CHANCES FARTHER SOUTH INTO NORTH DAKOTA. IN FACT...AM A
BIT CONCERNED WE MAY NOT HAVE TAKEN THE POPS FAR ENOUGH SOUTH IF
THE 4.0KM WRF NMM VERIFIES. A POTENTIAL LIMITING FACTOR COULD BE
DRY AIR IN THE LOW LEVELS...SO KEPT THE RAIN CHANCES GENERALLY
NORTH OF I-94.
THE NEXT CONCERN SURROUNDS THE FROST ADVISORY WHICH IS IN PLACE
ACROSS ROUGHLY THE SOUTHERN HALF OF THE FORECAST AREA THIS
MORNING. PASSING HIGH CLOUDS AHEAD OF THE UPPER WAVE HAVE
HELPED TEMPERATURES RISE A FEW DEGREES OVERNIGHT IN SOME
LOCATIONS...BUT READINGS IN THE ADVISORY AREA REMAIN IN THE 30S
TO LOWER 40S. THE HIGH CLOUDS ARE RATHER THIN ON THEIR SOUTHERN
EDGE...AND WITH GFS LAMP GUIDANCE STILL SUPPORTING FALLING
TEMPERATURES AT MOST LOCATIONS...WILL KEEP THE ADVISORY IN PLACE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 308 AM CDT SAT SEP 13 2014
THE LONG TERM PERIOD BEGINNING SUNDAY LOOKS RATHER TRANQUIL THROUGH
MID WEEK. PATCHY MORNING FROST CAN NOT BE RULED OUT EARLY SUNDAY AND
MONDAY MORNINGS WITH SURFACE HIGH PRESSURE OVER THE AREA AND A
NORTHWEST UPPER FLOW KEEPING SEASONABLY COOL AIR OVER THE NORTHERN
PLAINS. OTHERWISE IT LOOKS DRY WITH A WARMING TREND THROUGH MIDWEEK.
MORNING LOWS IN THE MID 30S TO LOWER 40S...AND DAYTIME HIGHS IN
THE UPPER 50S AND 60S SUNDAY AND MONDAY...WILL WARM TO THE MID 40S
TO MID 50S FOR LOWS...AND 70S FOR HIGHS BY MID TO LATE WEEK.
A PROGRESSIVE UPPER LEVEL TROUGH MOVING ONTO THE WESTERN U.S. COAST
ON THURSDAY WILL APPROACH THE NORTHERN PLAINS BY LATE FRIDAY.
THERE ARE DIFFERENCES IN THE HANDLING OF THIS WAVE BETWEEN THE GFS
AND ECMWF MODELS BUT BOTH BRING INCREASING MOISTURE AND A SMALL
CHANCE OF SHOWERS AND ISOLATED THUNDER LATE THURSDAY INTO EARLY
FRIDAY...WITH THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY
AND FRIDAY NIGHT AND POSSIBLY LINGERING IN THE EAST EARLY
SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 845 AM CDT SAT SEP 13 2014
COLD FRONT WILL TRACK ACROSS THE STATE TODAY. WIDELY SCATTERED
SHOWERS NORTH. VFR EXPECTED TO CONTINUE. CEILINGS AS LOW AS 35
HUNDRED AGL KDIK-KISN-KMOT...5 THOUSAND AGL OR GREATER BIS-KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CK
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
707 AM CDT SAT SEP 13 2014
.UPDATE...
ISSUED AT 705 AM CDT SAT SEP 13 2014
MINIMAL CHANGES THIS UPDATE. TWEAKED WIND GUST TIMING SLIGHTLY
BASED ON 88D VWP 925MB WINDS...HRRR AND NAM12 SFC WIND FCST. LATER
SHIFTS WILL NEED TO REFINE TIMING OF -SHRA AND AREAL COVERAGE.
OTRW FROST ADVISORY EXP 13Z.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 338 AM CDT SAT SEP 13 2014
NO CHANGE IN THE CURRENT FROST ADVISORY...ALTHOUGH A FEW LOCATIONS
OVER THE FAR EASTERN CWFA ARE IN THE MID 20S AT 08Z. WITH CIRRUS
INCREASING AND RETURN FLOW DEVELOPING DO NOT EXPECT TEMPERATURES
TO FALL MORE THAN 1 OR 2 DEGREES IN THE KVWU...KBJI...KBDO AND
KADC AREAS.
TODAY WILL BE A TRANSITION DAY. AS THE UNSEASONALLY COLD HIGH
MOVES SOUTH...LOW PRESSURE INTENSIFIES OVER SASKATCHEWAN SOUTH
WINDS WILL INCREASE BY MID DAY. THE MODELS INITIALIZED WELL AND
WILL FOLLOW THE HIGHER RESOLUTION HRRR AND NAM12 TODAY...BLENDING
THE NAM/GFS FOR TONIGHT INTO SUNDAY MORNING. TIMING OF WARM
ADVECTION PRECIPITATION AHEAD OF WELL DEFINED UPPER WAVE OVER
FAR NORTH-CENTRAL MONTANA SIMILAR TO PREVIOUS FORECAST REACHING THE
DEVILS LAKE BASIN AROUND 18Z AND SPREADING EAST. NAM/GFS HAVE
SMALL AREA OF 0C SHOWALTERS AND SOME ML CAPE BUT WILL NOT MENTION
TSRA ATTM. WITH WELL MIXED LAYER TO AROUND 800 MB...35 KTS AT 850
IN THE NAM AND NEAR 30 KTS IN THE GFS TRANSLATE TO GUSTS CLOSE TO
30 KTS POSSIBLE. MOS HAS 27 KTS AND WILL FOLLOW THAT FOR THE 18Z -
00Z PERIOD.
SECOND STRONGER SHORTWAVE...DROPPING ALONG THE ALBERTA/SASKATCHEWAN
BORDER IS FORECAST TO BE NEAR KDVL AT 06Z TONIGHT. SURFACE LOW
SLOWS AND WRAP AROUND SHRA SPREADING OVER THE EAST HALF OF THE
CWFA INTO SUNDAY MORNING.
THE COLUMN COOLS AND DRIES MOST AREAS SUNDAY...WITH LINGERING SHRA
OVER THE NORTHEAST PORTION OF THE CWFA...WITH STRONGER MID-UPPER
CAA ALONG SHEAR AXIS AND ENTRANCE REGION OF UPPER JET. THIS
QUICKLY MOVES OUT WITH PRECIPITATION ENDING BY 00Z MONDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 AM CDT SAT SEP 13 2014
WINDS DIMINISH AND SKIES CLEAR AS HIGH PRESSURE MOVES ACROSS THE
CWFA. LOWS WILL FALL BACK INTO THE LOW TO MID 30S...BUT EXPECT
SUFFICIENT MIXING AT THIS TIME TO KEEP FROST/FREEZE RISK MINIMAL
FOR MONDAY MORNING. LIGHT SOUTHWEST WINDS AND PLENTIFUL SUNSHINE WILL
ALLOW MODEST WARM-UP MONDAY TO NEAR MID SEPTEMBER NORMALS. RISING
HEIGHTS AND CONTINUED WESTERLY FLOW WILL MAKE FOR A MAINLY CLEAR
AND MILD MONDAY NIGHT.
TUESDAY TO FRIDAY...CONFLUENT NW FLOW ALOFT FOR MUCH OF THE WEEK
WITH A QUICK TRANSITIONING PERIOD THURSDAY INTO FRIDAY. AS A RESULT
DRY CONDITIONS EXPECTED WITH MODERATING TEMPS AS THICKNESSES
INCREASE WITH RIDGING OVER THE FA BY THURSDAY. BY THURSDAY PM OR
FRIDAY DEPENDING ON MODEL OF CHOICE...500MB SW FLOW AND 850MB LLJ
BRING INSTABILITY INTO FA FROM WEST TO EAST. WENT WITH A MOSTLY
SHRA AND ISO THUNDER FOR WX GRIDS AS SHOWALTERS DO BECOME NEGATIVE
AHEAD OF THE SFC TROUGH EXPECTED TO IMPACT THE NORTHERN PLAINS
TOWARDS THE END OF THE WEEK. TEMPERATURES ABOVE NORMAL THROUGH THE
WEEK CAN BE EXPECTED WITH SOME HUMIDITY POSSIBLE BY WEEKS END.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 1133 AM CDT SAT SEP 13 2014
VFR CIG/VSBY THROUGH THIS PERIOD...WITH INCRG SOUTH WINDS. BY 16Z
EXPECT G25KTS MOST TAF SITES. WSHFT FCST AT KDVL ABT 22Z. WDLY SCT
-SHRA PSBL AFT 18Z...BUT INSUFFICIENT CONFIDENCE TO PUT IN TAF
ATTM. -SHRA MOST LIKELY KDVL...KGFK...KTVF LINE AFT 21Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR NDZ030-039-049-
052-053.
MN...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR MNZ001>003-005-
006-008-009-013>017-022>024-027>032-040.
&&
$$
UPDATE...EWENS
SHORT TERM...EWENS
LONG TERM...JK/EWENS
AVIATION...EWENS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
634 AM CDT SAT SEP 13 2014
.UPDATE...
ISSUED AT 633 AM CDT SAT SEP 13 2014
LATEST SURFACE ANALYSIS SHOWS SURFACE CDFNT OVER WESTERN NORTH
DAKOTA WITH STRATOCU DECK DROPPING SOUTH FROM ALBERTA AND WESTERN
SASKATCHEWAN INTO NORTH CENTRAL MONTANA. LATEST 10 UTC RAP LOOKS
TO BE A LITTLE TOO QUICK IN BRINGING HIGHER 850 MB MOISTURE INTO
WESTERN NORTH DAKOTA...BUT BASED ON LATEST SATELLITE AND
OBSERVATIONS HAVE BUMPED UP SKY COVER ACROSS THE WEST LATER THIS
MORNING AND OVER THE NORTH AND CENTRAL THIS AFTERNOON. NO CHANGES
TO POPS AT THIS TIME...KEEPING SLIGHT CHANCE MAINLY NORTH OF THE
I94 CORRIDOR...WHICH IS IN AGREEMENT WITH LATEST RAP/HRRR
ITERATIONS. CURRENT TEMPERATURES REMAIN IN THE MID 30S ACROSS MOST
OF THE FROST ADVISORY AREA...THUS WILL KEEP IT GOING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 308 AM CDT SAT SEP 13 2014
EARLY MORNING WATER VAPOR IMAGERY SHOWED AN UPPER WAVE MOVING
SOUTHEAST ACROSS SOUTHERN SASKATCHEWAN WHICH WAS PUSHING A COLD
FRONT TOWARDS THE STATE. THE UPPER WAVE IS EXPECTED TO MOVE
QUICKLY ACROSS THE NORTHERN PLAINS TODAY ALONG WITH THE COLD
FRONT. THE MAIN QUESTION WILL BE HOW FAR SOUTH TO BRING A CHANCE
OF RAIN SHOWERS TODAY AS THE WAVE / COLD FRONT PASS. THERE ARE A
WIDE VARIETY OF MODEL SOLUTIONS WITH DIFFERING PLACEMENT...BUT DUE
TO THE STRENGTH OF THE WAVE OPTED TO FAVOR THE MODELS WHICH BRING
THE RAIN CHANCES FARTHER SOUTH INTO NORTH DAKOTA. IN FACT...AM A
BIT CONCERNED WE MAY NOT HAVE TAKEN THE POPS FAR ENOUGH SOUTH IF
THE 4.0KM WRF NMM VERIFIES. A POTENTIAL LIMITING FACTOR COULD BE
DRY AIR IN THE LOW LEVELS...SO KEPT THE RAIN CHANCES GENERALLY
NORTH OF I-94.
THE NEXT CONCERN SURROUNDS THE FROST ADVISORY WHICH IS IN PLACE
ACROSS ROUGHLY THE SOUTHERN HALF OF THE FORECAST AREA THIS
MORNING. PASSING HIGH CLOUDS AHEAD OF THE UPPER WAVE HAVE
HELPED TEMPERATURES RISE A FEW DEGREES OVERNIGHT IN SOME
LOCATIONS...BUT READINGS IN THE ADVISORY AREA REMAIN IN THE 30S
TO LOWER 40S. THE HIGH CLOUDS ARE RATHER THIN ON THEIR SOUTHERN
EDGE...AND WITH GFS LAMP GUIDANCE STILL SUPPORTING FALLING
TEMPERATURES AT MOST LOCATIONS...WILL KEEP THE ADVISORY IN PLACE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 308 AM CDT SAT SEP 13 2014
THE LONG TERM PERIOD BEGINNING SUNDAY LOOKS RATHER TRANQUIL THROUGH
MID WEEK. PATCHY MORNING FROST CAN NOT BE RULED OUT EARLY SUNDAY AND
MONDAY MORNINGS WITH SURFACE HIGH PRESSURE OVER THE AREA AND A
NORTHWEST UPPER FLOW KEEPING SEASONABLY COOL AIR OVER THE NORTHERN
PLAINS. OTHERWISE IT LOOKS DRY WITH A WARMING TREND THROUGH MIDWEEK.
MORNING LOWS IN THE MID 30S TO LOWER 40S...AND DAYTIME HIGHS IN
THE UPPER 50S AND 60S SUNDAY AND MONDAY...WILL WARM TO THE MID 40S
TO MID 50S FOR LOWS...AND 70S FOR HIGHS BY MID TO LATE WEEK.
A PROGRESSIVE UPPER LEVEL TROUGH MOVING ONTO THE WESTERN U.S. COAST
ON THURSDAY WILL APPROACH THE NORTHERN PLAINS BY LATE FRIDAY.
THERE ARE DIFFERENCES IN THE HANDLING OF THIS WAVE BETWEEN THE GFS
AND ECMWF MODELS BUT BOTH BRING INCREASING MOISTURE AND A SMALL
CHANCE OF SHOWERS AND ISOLATED THUNDER LATE THURSDAY INTO EARLY
FRIDAY...WITH THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY
AND FRIDAY NIGHT AND POSSIBLY LINGERING IN THE EAST EARLY
SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 633 AM CDT SAT SEP 13 2014
A COLD FRONT WILL MOVE ACROSS NORTH DAKOTA TODAY. THIS WILL BRING
GUSTY WEST / NORTHWEST WINDS WITH INCREASING CLOUDS. HAVE KEPT
CEILINGS VFR FOR NOW...BUT COULD SEE THE POTENTIAL FOR
MVFR...ESPECIALLY AT KISN AND KMOT. WINDS DIMINISH SATURDAY EVENING
AS SURFACE HIGH PRESSURE BUILDS INTO WESTERN NORTH DAKOTA. CLOUDS
SHOULD DIMINISH SOUTH AND WEST...BUT THEY MAY LINGER ESPECIALLY
TOWARDS KMOT. A FEW RAIN SHOWERS ARE ALSO EXPECTED TODAY...BUT DID
NOT PUT THEM INTO THE TAF FOR NOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR NDZ020-
025-033>037-040>048-050-051.
&&
$$
UPDATE...TWH
SHORT TERM...CK
LONG TERM...TWH
AVIATION...CK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
339 AM CDT SAT SEP 13 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 338 AM CDT SAT SEP 13 2014
NO CHANGE IN THE CURRENT FROST ADVISORY...ALTHOUGH A FEW LOCATIONS
OVER THE FAR EASTERN CWFA ARE IN THE MID 20S AT 08Z. WITH CIRRUS
INCREASING AND RETURN FLOW DEVELOPING DO NOT EXPECT TEMPERATURES
TO FALL MORE THAN 1 OR 2 DEGREES IN THE KVWU...KBJI...KBDO AND
KADC AREAS.
TODAY WILL BE A TRANSITION DAY. AS THE UNSEASONALLY COLD HIGH
MOVES SOUTH...LOW PRESSURE INTENSIFIES OVER SASKATCHEWAN SOUTH
WINDS WILL INCREASE BY MID DAY. THE MODELS INITIALIZED WELL AND
WILL FOLLOW THE HIGHER RESOLUTION HRRR AND NAM12 TODAY...BLENDING
THE NAM/GFS FOR TONIGHT INTO SUNDAY MORNING. TIMING OF WARM
ADVECTION PRECIPITATION AHEAD OF WELL DEFINED UPPER WAVE OVER
FAR NORTH-CENTRAL MONTANA SIMILAR TO PREVIOUS FORECAST REACHING THE
DEVILS LAKE BASIN AROUND 18Z AND SPREADING EAST. NAM/GFS HAVE
SMALL AREA OF 0C SHOWALTERS AND SOME ML CAPE BUT WILL NOT MENTION
TSRA ATTM. WITH WELL MIXED LAYER TO AROUND 800 MB...35 KTS AT 850
IN THE NAM AND NEAR 30 KTS IN THE GFS TRANSLATE TO GUSTS CLOSE TO
30 KTS POSSIBLE. MOS HAS 27 KTS AND WILL FOLLOW THAT FOR THE 18Z -
00Z PERIOD.
SECOND STRONGER SHORTWAVE...DROPPING ALONG THE ALBERTA/SASKATCHEWAN
BORDER IS FORECAST TO BE NEAR KDVL AT 06Z TONIGHT. SURFACE LOW
SLOWS AND WRAP AROUND SHRA SPREADING OVER THE EAST HALF OF THE
CWFA INTO SUNDAY MORNING.
THE COLUMN COOLS AND DRIES MOST AREAS SUNDAY...WITH LINGERING SHRA
OVER THE NORTHEAST PORTION OF THE CWFA...WITH STRONGER MID-UPPER
CAA ALONG SHEAR AXIS AND ENTRANCE REGION OF UPPER JET. THIS
QUICKLY MOVES OUT WITH PRECIPITATION ENDING BY 00Z MONDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 AM CDT SAT SEP 13 2014
WINDS DIMINISH AND SKIES CLEAR AS HIGH PRESSURE MOVES ACROSS THE
CWFA. LOWS WILL FALL BACK INTO THE LOW TO MID 30S...BUT EXPECT
SUFFICIENT MIXING AT THIS TIME TO KEEP FROST/FREEZE RISK MINIMAL
FOR MONDAY MORNING. LIGHT SOUTHWEST WINDS AND PLENTIFUL SUNSHINE WILL
ALLOW MODEST WARM-UP MONDAY TO NEAR MID SEPTEMBER NORMALS. RISING
HEIGHTS AND CONTINUED WESTERLY FLOW WILL MAKE FOR A MAINLY CLEAR
AND MILD MONDAY NIGHT.
TUESDAY TO FRIDAY...CONFLUENT NW FLOW ALOFT FOR MUCH OF THE WEEK
WITH A QUICK TRANSITIONING PERIOD THURSDAY INTO FRIDAY. AS A RESULT
DRY CONDITIONS EXPECTED WITH MODERATING TEMPS AS THICKNESSES
INCREASE WITH RIDGING OVER THE FA BY THURSDAY. BY THURSDAY PM OR
FRIDAY DEPENDING ON MODEL OF CHOICE...500MB SW FLOW AND 850MB LLJ
BRING INSTABILITY INTO FA FROM WEST TO EAST. WENT WITH A MOSTLY
SHRA AND ISO THUNDER FOR WX GRIDS AS SHOWALTERS DO BECOME NEGATIVE
AHEAD OF THE SFC TROUGH EXPECTED TO IMPACT THE NORTHERN PLAINS
TOWARDS THE END OF THE WEEK. TEMPERATURES ABOVE NORMAL THROUGH THE
WEEK CAN BE EXPECTED WITH SOME HUMIDITY POSSIBLE BY WEEKS END.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1151 PM CDT FRI SEP 12 2014
A MOSTLY CLEAR SKY WAS ACROSS THE FORECAST AREA. SOME CIRRUS WAS
SPILLING INTO THE NORTHWEST ZONES AND WILL SPREAD ACROSS THE AREA
OVERNIGHT. FOG LOOP INDICATED PATCHY CLOUDS AROUND 6 THOUSAND FT
OVER THE FAR EASTERN ZONES. ONLY BJI HAS COME IN WITH SOME
RESTRICTION TO VISIBILITY DUE TO FOG. WILL ADD SOME FOG TO BJI TAF.
EXPECT VFR CIGS LATE SAT AFTERNOON/EVENING FROM THE WEST AS NEXT
SYSTEM APPROACHES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR NDZ030-039-049-
052-053.
MN...FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR MNZ001>003-005-
006-008-009-013>017-022>024-027>032-040.
&&
$$
SHORT TERM...EWENS
LONG TERM...JK
AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS NORMAN OK
1237 PM CDT SAT SEP 13 2014
.DISCUSSION...
AVIATION DISCUSSION FOR THE 18Z TAFS IS BELOW.
&&
.AVIATION...
GENERALLY HAVE MODERATE TO HIGH CONFIDENCE IN THE TAFS
THROUGH 06Z...THEN DECREASING CONFIDENCE AFTERWARDS.
THINK ALL SITES WILL BE VFR BY 20Z WITH KOKC...KOUN...
AND KSPS AS THE LAST SITES TO HAVE MVFR CEILINGS.
REDEVELOPMENT OF VFR/MVFR CEILINGS 1500-5000 FT AGL
WILL LIKELY OCCUR AFTER 06Z...MAINLY SOUTHWEST OF KGAG-
KOKC-KMLC. HEIGHT OF THESE CEILINGS REMAINS MOST UNCERTAIN.
WINDS WILL GENERALLY SHIFT TO THE SOUTHEAST AT ALL SITES
BY 01Z.
MBS
&&
.PREV DISCUSSION... /ISSUED 1037 AM CDT SAT SEP 13 2014/
DISCUSSION...
PERSISTENT CLOUD COVER WILL MAINTAIN RELATIVELY COOL WEATHER INTO
THE AFTERNOON OVER MOST OF OKLAHOMA AND NORTH TEXAS. CURRENT
SATELLITE TRENDS APPEAR TO SUPPORT THE HRRR MODEL FORECAST OF
CLOUD BREAKUP THIS AFTERNOON...EARLIER IN PARTS OF NORTHERN
OKLAHOMA...WHERE THERE ARE ALREADY LARGE HOLES IN THE CLOUD COVER.
THE FORECAST WAS UPDATED EARLIER THIS MORNING TO ACCOUNT FOR THE
LATEST TRENDS AND EXPECTATIONS.
PREV DISCUSSION... /ISSUED 638 AM CDT SAT SEP 13 2014/
AVIATION...
13/12Z TAFS...MVFR CIGS WILL BE SEEN AT MOST TERMINALS THROUGH
ABOUT 15-17Z...WITH VFR EXPECTED THEREAFTER. NORTHERLY WINDS WILL
BECOME SOUTHEAST LATE TODAY AND INCREASE IN SPEED AFTER THIS
FORECAST PERIOD. LOW CLOUDS WILL BEGIN TO INCREASE TOWARD END OF
FORECAST PERIOD BUT WILL LEAVE FCST VFR FOR NOW.
PREV DISCUSSION... /ISSUED 410 AM CDT SAT SEP 13 2014/
DISCUSSION...
CLEARING...AT LEAST PARTIALLY...EXPECTED THE REGION TODAY. THE
GREATEST AMOUNT OF CLEARING EXPECTED OVER THE NORTH-CENTRAL
PORTIONS OF OKLAHOMA. SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS
MAY ACTUALLY SEE MORE CLOUDS THAN SUN TODAY. NO PRECIPITATION
EXPECTED TODAY OR TONIGHT.
RETURN TO SOUTHERLY FLOW TONIGHT AND SUNDAY WILL ALLOW MOISTURE
TO WORK ITS WAY BACK OVER REGION AND ALLOW CLOUDS TO FILL BACK IN
ON SUNDAY. RAIN CHANCES RETURN TO FORECAST SUNDAY NIGHT AS NEXT
UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT MOVE OVER SOUTHERN
PLAINS. MOST OF THE PRECIP EXPECTED NEAR THE FRONT AS IT
PROGRESSES SLOWLY SOUTH OVER OKLAHOMA TO THE RED RIVER VALLEY
MONDAY AFTERNOON AND MONDAY NIGHT. FRONT LIFTS BACK NORTH TUESDAY
INTO WEDNESDAY...AND WITH DEVELOPMENT OF NWLY FLOW...WILL BE A
FOCUS FOR SHOWERS AND STORMS WEDNESDAY INTO THURSDAY MAINLY OVER
THE EASTERN HALF OF OKLAHOMA. CONFIDENCE NOT QUITE AS HIGH SO POPS
WILL REMAIN ON THE LOW SIDE OF GUIDANCE. FAIR AMOUNT OF DISPARITY
IN THE MEDIUM RANGE MODELS FOR FRIDAY AND NEXT WEEKEND...WITH ECM
CURRENTLY SHOWING PROLONGED PERIOD OF RAIN AND GFS A MORE
PROGRESSIVE AND DRY PATTERN. TRENDS WILL NEED TO BE MONITORED
BEFORE POPS ARE INTRODUCED AT END OF FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 66 57 80 66 / 0 0 10 20
HOBART OK 70 55 80 65 / 0 0 10 20
WICHITA FALLS TX 67 59 81 68 / 10 0 10 10
GAGE OK 71 53 82 63 / 0 0 10 10
PONCA CITY OK 67 53 79 65 / 0 0 10 20
DURANT OK 68 60 78 66 / 10 0 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
23/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
1037 AM CDT SAT SEP 13 2014
.DISCUSSION...
PERSISTENT CLOUD COVER WILL MAINTAIN RELATIVELY COOL WEATHER INTO
THE AFTERNOON OVER MOST OF OKLAHOMA AND NORTH TEXAS. CURRENT
SATELLITE TRENDS APPEAR TO SUPPORT THE HRRR MODEL FORECAST OF
CLOUD BREAKUP THIS AFTERNOON...EARLIER IN PARTS OF NORTHERN
OKLAHOMA...WHERE THERE ARE ALREADY LARGE HOLES IN THE CLOUD COVER.
THE FORECAST WAS UPDATED EARLIER THIS MORNING TO ACCOUNT FOR THE
LATEST TRENDS AND EXPECTATIONS.
&&
.PREV DISCUSSION... /ISSUED 638 AM CDT SAT SEP 13 2014/
AVIATION...
13/12Z TAFS...MVFR CIGS WILL BE SEEN AT MOST TERMINALS THROUGH
ABOUT 15-17Z...WITH VFR EXPECTED THEREAFTER. NORTHERLY WINDS WILL
BECOME SOUTHEAST LATE TODAY AND INCREASE IN SPEED AFTER THIS
FORECAST PERIOD. LOW CLOUDS WILL BEGIN TO INCREASE TOWARD END OF
FORECAST PERIOD BUT WILL LEAVE FCST VFR FOR NOW.
PREV DISCUSSION... /ISSUED 410 AM CDT SAT SEP 13 2014/
DISCUSSION...
CLEARING...AT LEAST PARTIALLY...EXPECTED THE REGION TODAY. THE
GREATEST AMOUNT OF CLEARING EXPECTED OVER THE NORTH-CENTRAL
PORTIONS OF OKLAHOMA. SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS
MAY ACTUALLY SEE MORE CLOUDS THAN SUN TODAY. NO PRECIPITATION
EXPECTED TODAY OR TONIGHT.
RETURN TO SOUTHERLY FLOW TONIGHT AND SUNDAY WILL ALLOW MOISTURE
TO WORK ITS WAY BACK OVER REGION AND ALLOW CLOUDS TO FILL BACK IN
ON SUNDAY. RAIN CHANCES RETURN TO FORECAST SUNDAY NIGHT AS NEXT
UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT MOVE OVER SOUTHERN
PLAINS. MOST OF THE PRECIP EXPECTED NEAR THE FRONT AS IT
PROGRESSES SLOWLY SOUTH OVER OKLAHOMA TO THE RED RIVER VALLEY
MONDAY AFTERNOON AND MONDAY NIGHT. FRONT LIFTS BACK NORTH TUESDAY
INTO WEDNESDAY...AND WITH DEVELOPMENT OF NWLY FLOW...WILL BE A
FOCUS FOR SHOWERS AND STORMS WEDNESDAY INTO THURSDAY MAINLY OVER
THE EASTERN HALF OF OKLAHOMA. CONFIDENCE NOT QUITE AS HIGH SO POPS
WILL REMAIN ON THE LOW SIDE OF GUIDANCE. FAIR AMOUNT OF DISPARITY
IN THE MEDIUM RANGE MODELS FOR FRIDAY AND NEXT WEEKEND...WITH ECM
CURRENTLY SHOWING PROLONGED PERIOD OF RAIN AND GFS A MORE
PROGRESSIVE AND DRY PATTERN. TRENDS WILL NEED TO BE MONITORED
BEFORE POPS ARE INTRODUCED AT END OF FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 66 57 80 66 / 0 0 10 20
HOBART OK 70 55 80 65 / 0 0 10 20
WICHITA FALLS TX 67 59 81 68 / 10 0 10 10
GAGE OK 71 53 82 63 / 0 0 10 10
PONCA CITY OK 67 53 79 65 / 0 0 10 20
DURANT OK 68 60 78 66 / 10 0 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
23/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1156 PM EDT SUN SEP 14 2014
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL MAINTAIN A RATHER LONG STRETCH OF
COOL AND MAINLY DRY WEATHER. A WEAK FRONTAL SYSTEM WILL PASS
THROUGH MONDAY NIGHT AND EARLY TUESDAY MORNING...AND WILL BE THE
ONLY TIME WHEN RAIN IS POSSIBLE THROUGH THE END OF THE COMING
WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
23Z RAP /AND LATEST REGIONAL SFC OBS/ INDICATES THAT A SECONDARY
CENTER OF SFC-925 MB HIGH PRESSURE WILL DRIFTING ACROSS SWRN AND
SCENT PENN OVERNIGHT. THIS WEATHER FEATURE WILL SUPPLY MAINLY
CLEAR SKIES AND L/V WIND ACROSS MUCH OF THE FCST AREA TONIGHT WITH
JUST SOME PATCHY STRATO CU OR RIBBONS OF THIN CIRRUS DRIFTING BY.
HOWEVER...THE LIGHT/WNW FLOW ACROSS THE NW AND NCENT MTNS
/COMBINED WITH LIMITED LLVL MOISTURE OFF THE UPSTREAM GLAKES AND
1-2 DEG C OF COOLING IN THE 925-850 MB LAYER/ WILL RESULT IN AREAS
OF BKN-OVC STRATO CU DRIFTING ESE FOR THE NEXT 3-5 HOURS.
THE HIGH WILL BE ACCOMPANIED BY BELOW NORMAL PWATS OF LESS THAN
0.75 OF AN INCH...LIGHT SFC-925 MB WINDS /GRADUALLY VEERING AROUND
TO THE N-E/...AND BELOW NORMAL TEMPS AT 850 MB.
EXPECTING THAT WE SEE A GRADUAL DECREASE IN THE STRATO CU FOR
SEVERAL HOURS EARLY MONDAY MORNING...THIS HIGH AND ITS ASSOCIATED
COOL AIRMASS WILL BRING CONDITIONS FAVORABLE FOR THE FIRST
WIDESPREAD FROST OF THE SEASON ACROSS NRN PENN...WHERE TEMPS OF
33-37 ARE LIKELY LATE TONIGHT THROUGH EARLY MONDAY. A FROST
ADVISORY REMAINS IN EFFECT ACROSS 4 OF OUR TYPICALLY COLDEST NRN
MTN COUNTIES - FROM 08-13Z MONDAY.
ELSEWHERE...PATCHY STRATO CU AND THIN STREAKS OF CIRRUS WILL HAVE
MINIMAL EFFECT ON TEMPS OVERNIGHT...WITH THE MERCURY FALLING
STEADILY TO CHILLY READINGS BY DAYBREAK MONDAY IN THE 30S
NORTH...TO MID 40S SOUTH.
LARGE AIR/WATER TEMP SPREAD...AND SFC DEWPOINTS BETWEEN 43-47F
WILL LEAD TO PATCHY DENSE RIVER VALLEY FOG...ESPECIALLY
THROUGHOUT THE DEEPER VALLEYS OF CENTRAL AND NRN PENN.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
ANY LOWER CLOUDS IN THE SC/SE IN THE MORNING SHOULD SLIDE TO THE
EAST AND DISSIPATE AS WE SAW WHAT HAPPENED SUN MORNING. GOOD SHORT
WAVE MOVING W-E OVER THE GREAT LAKES WILL PULL ENOUGH MOISTURE
INTO THE AREA TO CREATE A FEW TENTHS OF AN INCH OF RAIN MON NIGHT.
THE POPS SHOULD BE HIGH IN THE N AND NOT QUITE AS HIGH IN THE
SW...BUT SHOWERS ALSO LIKELY OR BETTER IN THE SE. THE FAST
MOVEMENT OF THE SYSTEM SHOULD PUSH ALL OF THE PRECIP TO THE EAST
OF THE AREA AT OR JUST AFTER SUNRISE ON TUESDAY MORNING.
MAXES MONDAY WILL GET PRETTY CLOSE TO NORMALS...AND THE CLOUDS AND
HIGHER DEWPOINTS SHOULD HOLD TEMPS UP IN THE 50S IN MOST PLACES
TUESDAY MORNING. THE COOLING EFFECTS OF THE RAIN AND EARLY PASSAGE
OF THE COLD FRONT WILL HELP THE NRN TIER DIP INTO THE 40S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
SHORTWAVE LIFTING INTO NEW ENGLAND BY TUE...BUT SCT LINGERING
LIGHT SHOWERS MAY PERSIST THROUGH MIDDAY BEFORE COOLER...DRIER
AIR FILTERS IN WITH INCREASING AMOUNTS OF SUNSHINE. NORTHWEST
FLOW AND SURFACE HIGH PRESSURE WILL BRING QUIET WEATHER FOR LATER
TUE THROUGH FRI...WITH JUST A WEAK FRONTAL BOUNDARY WASHING OUT
AS IT MOVES THROUGH MIDWEEK...FOLLOWED BY A REINFORCING SHOT OF
COOLER AIR. EXPECT CHILLY MORNINGS /POSS BOTTOMING OUT IN THE 30S
IN PORTIONS OF NORTHERN MOUNTAINS/ AND DAILY HIGHS RUNNING ABOUT
5F BELOW NORMAL.
GFS/ECMWF STILL DIFFER ON STRENGTH OF A SHORTWAVE TROUGH HEADED
OUR WAY FOR NEXT WEEKEND...BUT OVERALL TREND WILL BE FLOW TURNING
AROUND TO THE SOUTHWEST WITH A MODERATION OF TEMPS STARTING
SAT...AND RAIN CHANCES INCREASING FOR SUNDAY.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
A WEAK SHORTWAVE ALOFT IS HELPING TO PRODUCE SOME STRATOCU OVER
THE NW AND CENTRAL MTNS. RESULTING CIGS SHOULD REMAIN VFR AND
SHOULD SCATTER OUT OVER THE NEXT SEVERAL HOURS AT MOST LOCATIONS.
TO THE SOUTH...AN AREA OF LOW- ER CLOUDS COULD MOVE INTO THE SRN
TERMINALS OVERNIGHT. MVFR CONDITIONS ARE POSSIBLE FROM THE STRATUS
WHICH WILL TRY TO SLIDE IN FROM THE S AFTER MIDNIGHT. THE LAYER IS
CURRENTLY HUNG UP OVER NRN WV AND IS NOT ENTIRELY LIKELY TO MAKE
IT INTO CENTRAL PA. MIXING IN OF DRIER AIR AT THE LEADING EDGE
WILL BE A KNOCK ON THE NRN MOVEMENT OF THE CLOUDS.
PATCHY FOG IS EXPECTED IN THE MORE- CLEAR AREAS IN THE MORNING.
IFR POSSIBLE IN THE DEEPER VALLEYS AROUND SUNRISE.
A HEALTHY SHORT WAVE WILL MOVE W-E THRU THE GREAT LAKES AND DRAG
COLD FRONT THROUGH MONDAY NIGHT AND VERY EARLY TUESDAY. SHOWERS
ARE EXPECTED TO CREATE REDUCTIONS IN THE FLYING CONDITIONS MONDAY
NIGHT...BUT SHOULD BE OFF TO THE EAST BY 12Z TUES. LINGERING LOWER
CLOUDS AND SOME FOG WILL LAST INTO THE DAY ON TUESDAY BEFORE
CLEARING STARTS.
OUTLOOK...
TUE NIGHT-FRI...AM FOG POSS...OTHERWISE NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 4 AM TO 9 AM EDT MONDAY FOR PAZ005-006-010-
037.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
855 PM EDT SUN SEP 14 2014
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL MAINTAIN A RATHER LONG STRETCH OF
COOL AND MAINLY DRY WEATHER. A WEAK FRONTAL SYSTEM WILL PASS
THROUGH MONDAY NIGHT AND EARLY TUESDAY MORNING...AND WILL BE THE
ONLY TIME WHEN RAIN IS POSSIBLE THROUGH THE END OF THE COMING
WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
23Z RAP /AND LATEST REGIONAL SFC OBS/ INDICATES THAT A SECONDARY
CENTER OF SFC-925 MB HIGH PRESSURE WILL DRIFTING ACROSS SWRN AND
SCENT PENN OVERNIGHT. THIS WEATHER FEATURE WILL SUPPLY MAINLY
CLEAR SKIES AND L/V WIND ACROSS MUCH OF THE FCST AREA TONIGHT WITH
JUST SOME PATCHY STRATO CU OR RIBBONS OF THIN CIRRUS DRIFTING BY.
HOWEVER...THE LIGHT/WNW FLOW ACROSS THE NW AND NCENT MTNS
/COMBINED WITH LIMITED LLVL MOISTURE OFF THE UPSTREAM GLAKES AND
1-2 DEG C OF COOLING IN THE 925-850 MB LAYER/ WILL RESULT IN AREAS
OF BKN-OVC STRATO CU DRIFTING ESE FOR THE NEXT 3-5 HOURS.
THE HIGH WILL BE ACCOMPANIED BY BELOW NORMAL PWATS OF LESS THAN
0.75 OF AN INCH...LIGHT SFC-925 MB WINDS /GRADUALLY VEERING AROUND
TO THE N-E/...AND BELOW NORMAL TEMPS AT 850 MB.
EXPECTING THAT WE SEE A GRADUAL DECREASE IN THE STRATO CU FOR
SEVERAL HOURS EARLY MONDAY MORNING...THIS HIGH AND ITS ASSOCIATED
COOL AIRMASS WILL BRING CONDITIONS FAVORABLE FOR THE FIRST
WIDESPREAD FROST OF THE SEASON ACROSS NRN PENN...WHERE TEMPS OF
33-37 ARE LIKELY LATE TONIGHT THROUGH EARLY MONDAY. A FROST
ADVISORY REMAINS IN EFFECT ACROSS 4 OF OUR TYPICALLY COLDEST NRN
MTN COUNTIES - FROM 08-13Z MONDAY.
ELSEWHERE...PATCHY STRATO CU AND THIN STREAKS OF CIRRUS WILL HAVE
MINIMAL EFFECT ON TEMPS OVERNIGHT...WITH THE MERCURY FALLING
STEADILY TO CHILLY READINGS BY DAYBREAK MONDAY IN THE 30S
NORTH...TO MID 40S SOUTH.
LARGE AIR/WATER TEMP SPREAD...AND SFC DEWPOINTS BETWEEN 43-47F
WILL LEAD TO PATCHY DENSE RIVER VALLEY FOG...ESPECIALLY
THROUGHOUT THE DEEPER VALLEYS OF CENTRAL AND NRN PENN.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
ANY LOWER CLOUDS IN THE SC/SE IN THE MORNING SHOULD SLIDE TO THE
EAST AND DISSIPATE AS WE SAW WHAT HAPPENED SUN MORNING. GOOD SHORT
WAVE MOVING W-E OVER THE GREAT LAKES WILL PULL ENOUGH MOISTURE
INTO THE AREA TO CREATE A FEW TENTHS OF AN INCH OF RAIN MON NIGHT.
THE POPS SHOULD BE HIGH IN THE N AND NOT QUITE AS HIGH IN THE
SW...BUT SHOWERS ALSO LIKELY OR BETTER IN THE SE. THE FAST
MOVEMENT OF THE SYSTEM SHOULD PUSH ALL OF THE PRECIP TO THE EAST
OF THE AREA AT OR JUST AFTER SUNRISE ON TUESDAY MORNING.
MAXES MONDAY WILL GET PRETTY CLOSE TO NORMALS...AND THE CLOUDS AND
HIGHER DEWPOINTS SHOULD HOLD TEMPS UP IN THE 50S IN MOST PLACES
TUESDAY MORNING. THE COOLING EFFECTS OF THE RAIN AND EARLY PASSAGE
OF THE COLD FRONT WILL HELP THE NRN TIER DIP INTO THE 40S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
SHORTWAVE LIFTING INTO NEW ENGLAND BY TUE...BUT SCT LINGERING
LIGHT SHOWERS MAY PERSIST THROUGH MIDDAY BEFORE COOLER...DRIER
AIR FILTERS IN WITH INCREASING AMOUNTS OF SUNSHINE. NORTHWEST
FLOW AND SURFACE HIGH PRESSURE WILL BRING QUIET WEATHER FOR LATER
TUE THROUGH FRI...WITH JUST A WEAK FRONTAL BOUNDARY WASHING OUT
AS IT MOVES THROUGH MIDWEEK...FOLLOWED BY A REINFORCING SHOT OF
COOLER AIR. EXPECT CHILLY MORNINGS /POSS BOTTOMING OUT IN THE 30S
IN PORTIONS OF NORTHERN MOUNTAINS/ AND DAILY HIGHS RUNNING ABOUT
5F BELOW NORMAL.
GFS/ECMWF STILL DIFFER ON STRENGTH OF A SHORTWAVE TROUGH HEADED
OUR WAY FOR NEXT WEEKEND...BUT OVERALL TREND WILL BE FLOW TURNING
AROUND TO THE SOUTHWEST WITH A MODERATION OF TEMPS STARTING
SAT...AND RAIN CHANCES INCREASING FOR SUNDAY.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
ANY LINGERING CU WILL DISSIPATE IN THE NEXT HOUR OR SO LEADING TO
GENERALLY CLEAR SKIES OVERNIGHT. AREA OF LOW- ER CLOUDS COULD MOVE INTO
THE SRN TERMINALS LATER TONIGHT. MVFR CONDITIONS ARE POSSIBLE FROM
THE STRATUS WHICH WILL TRY TO SLIDE IN FROM THE S AFTER MIDNIGHT.
THE LAYER IS CURRENTLY HUNG UP OVER NRN WV AND IS NOT ENTIRELY
LIKELY TO MAKE IT INTO CENTRAL PA. MIXING IN OF DRIER AIR AT THE
LEADING EDGE WILL BE A KNOCK ON THE NRN MOVEMENT OF THE CLOUDS.
PATCHY FOG IS EXPECTED IN THE MORE- CLEAR AREAS IN THE MORNING.
IFR POSSIBLE IN THE DEEPER VALLEYS AROUND SUNRISE.
A HEALTHY SHORT WAVE WILL MOVE W-E THRU THE GREAT LAKES AND DRAG
COLD FRONT THROUGH MONDAY NIGHT AND VERY EARLY TUESDAY. SHOWERS
ARE EXPECTED TO CREATE REDUCTIONS IN THE FLYING CONDITIONS MONDAY
NIGHT...BUT SHOULD BE OFF TO THE EAST BY 12Z TUES. LINGERING LOWER
CLOUDS AND SOME FOG WILL LAST INTO THE DAY ON TUESDAY BEFORE
CLEARING STARTS.
OUTLOOK...
TUE NIGHT-FRI...AM FOG POSS...OTHERWISE NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 4 AM TO 9 AM EDT MONDAY FOR PAZ005-006-010-
037.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
335 AM EDT SAT SEP 13 2014
.SYNOPSIS...
A SERIES OF SHORT WAVES WILL CARVE OUT PERSISTENT AND STRONG MID-
TROPOSPHERIC TROUGH OVER THE EASTERN UNITED STATES. THE FIRST
WAVE WILL PRODUCE SOME SHOWERS SATURDAY. SUBSEQUENT WAVES SHOULD
KEEP DEEP MOISTURE WELL TO OUR SOUTH...SO IT WILL BE RELATIVELY
DRY. SOME UNSEASONABLY COOL WEATHER IS LIKELY NEAR MID-WEEK BEFORE
THE PATTERN BEGINS TO WEAKEN BY THE END OF THE COMING WEEK.
&&
.NEAR TERM /UNTIL 9 AM THIS MORNING/...
CLOUDS WILL SLOWLY INCREASE WEST TO EAST OVERNIGHT THEN RAPIDLY IN
THE MORNING. A FAST MOVING SHORT-WAVE OVER MICHIGAN WILL BRING A
CHANCE OF SHOWERS INTO WESTERN AREAS BEFORE 6 AM. AND SLOWLY
SPREAD INTO THE WESTERN AREAS OF OUR COUNTY WARNING AREA.
THE HIGHER RESOLUTION MODELS AND SREF FAVOR THE CHANCE OF RAINFALL
MAINLY AFTER 7 AM.
&&
.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM SUNDAY/...
THE FAST MOVING AND STRONG SHORT-WAVE SHOULD BRING RAIN AND
SHOWERS TO CENTRAL AND WESTERN AREAS IN THE MORNING AND INTO
MIDDAY BEFORE THE HIGHER PROBABILITIES SHIFT TO THE EAST. EASTERN
AREAS SHOULD SEE THE RAIN BY LATE MORNING AND INTO THE AFTERNOON
HOURS. THE SREF IMPLIES LITTLE OR NO RAIN AFTER ABOUT MIDDAY IN
CENTRAL AND WESTERN AREAS AND BY ABOUT 3 PM IN THE EAST. POPS
CRASH AFTER 18Z IN THE EAST.
THE RAIN WILL RAPIDLY END WEST TO EAST AND THERE COULD BE PEAKS OF
SUN IN THE WEST AND CENTRAL AREAS IN THE AFTERNOON. THIS FAST
MOVING SYSTEM AND ITS REINFORCING COLD AIR WILL BE TO OUR EAST BY
LATER AFTERNOON OR EARLY EVENING.
MOST AREAS WILL SEE A 2-4 HOUR PERIOD OF RAINFALL. RAINFALL
AMOUNTS SHOULD BE IN THE 0.10 TO 0.30 INCH RANGE IN MOST AREAS.
THE RAP FAVORS HIGHER AMOUNTS IN NORTH CENTRAL AND THE SREF IS A
SPLIT DECISION WITH SOME HIGHER AMOUNTS IN IN THE SOUTH AND
FARTHER NORTH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BIG...1027MB HIGH PRESSURE SHOVES IN FROM THE WEST ON SATURDAY
NIGHT. THIS STARTS WHAT SHOULD BE AN ALMOST UNBROKEN STRING OF
COOL AND DRY WEATHER FOR THE ENTIRE LONG TERM PERIOD AND INTO
DAYS 8-PLUS. THE ONLY INKLING OF PRECIP WILL BE ON MON NIGHT AND
TUES MORNING. A WEAK FRONT MOVING DOWN FROM THE NW WILL TAP ONLY
MEAGER MOISTURES SINCE IT WILL LIE IN BETWEEN THE EARLY- WEEK HIGH
PRESSURE AND A SECOND EQUALLY DRY ANTICYCLONE MOVING IN FROM THE
UPPER GREAT LAKES AND MIDWEST. AT THE SAME TIME...THERE IS A WAVE
PROGGED TO BE SLIDING UP FROM THE GULF COAST STATES. HOWEVER...ALL
THE MODELS TAKE IT TO OUR SOUTH...GENERALLY THROUGH THE MID-
ATLANTIC STATES EARLY TUESDAY. THIS WOULD CREATE SOME RAIN/SHOWERS
ON MONDAY NIGHT AND EARLY TUESDAY. THERE MIGHT BE A BACKDOOR COLD
FRONT TRY TO MOVE DOWN AROUND THURSDAY...BUT NO MOISTURE IS TO BE
FOUND IN ITS VICINITY.
ONE POINT OF INTEREST WILL BE THE LOW TEMPERATURES SUNDAY MORNING
AND MONDAY MORNING. THE NORTHERN TIER...ESPECIALLY THE ICE BOX OF
KBFD...COULD GET INTO THE MID 30S BOTH MORNINGS - AND PERHAPS EVEN
THE LOWER 30S ON MONDAY MORNING. WHAT MIGHT BE MORE REMARKABLE IS
A POTENTIAL 30 TO 40F DIURNAL SWING ON MONDAY AS WINDS TURN TO THE
S/SW FOR THE DAYTIME BEFORE THE FRONT ARRIVES AT NIGHT/EARLY TUES.
BUT EVEN WITH THE GIANT SWING MONDAY SHOULD END UP JUST SLIGHTLY
BELOW NORMAL FOR MAXES. WELCOME AUTUMN.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
TIMING ON THE INCOMING RAIN IS THE BIG AVIATION CONCERN OVER THE
NEXT 12 HOURS. A SMALL BAND IS CURRENTLY MOVING ACROSS THE
SOUTHWESTERN TAF SITES...WHERE JST AND AOO HAVE MVFR CEILINGS. BFD
HAS GONE DOWN TO IFR AND SHOULD CONTINUE THROUGH THE MORNING.
THE SHOWERS WILL SPREAD ACROSS THE AREA BETWEEN ABOUT 09-15Z
SATURDAY MORNING ALONG WITH MVFR/IFR CONDITIONS DEVELOPING. THESE
CONDITIONS SHOULD CONTINUE UNTIL AROUND 18Z...BEFORE LIFTING AS
THE SYSTEM QUICKLY PASSES. WITH IMPROVING CONDITIONS SATURDAY
AFTERNOON.
OUTLOOK...
SUN...PATCHY AM FOG...OTHERWISE VFR.
MON...NO SIG WX.
MON NIGHT - TUE...A COLD FRONT WILL BRING REDUCED CONDITIONS WITH
SHOWERS.
WED...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM/LA CORTE
LONG TERM...DANGELO
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
331 AM EDT SAT SEP 13 2014
.SYNOPSIS...
AN AREA OF LOW PRESSURE AT THE SURFACE AND DISTURBANCE ALOFT
WILL MOVE QUICKLY EAST ACROSS THE AREA SATURDAY. HIGH PRESSURE
AND FAIR WEATHER WILL RETURN ON SUNDAY. THE OVERALL PATTERN FAVORS
BELOW NORMAL TEMPERATURES FOR THE NEXT WEEK.
&&
.NEAR TERM /UNTIL 9 AM THIS MORNING/...
CLOUDS WILL SLOWLY INCREASE WEST TO EAST OVERNIGHT THEN RAPIDLY IN
THE MORNING. A FAST MOVING SHORT-WAVE OVER MICHIGAN WILL BRING A
CHANCE OF SHOWERS INTO WESTERN AREAS BEFORE 6 AM. AND SLOWLY
SPREAD INTO THE WESTERN AREAS OF OUR COUNTY WARNING AREA.
THE HIGHER RESOLUTION MODELS AND SREF FAVOR THE CHANCE OF RAINFALL
MAINLY AFTER 7 AM.
&&
.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM SUNDAY/...
THE FAST MOVING AND STRONG SHORT-WAVE SHOULD BRING RAIN AND
SHOWERS TO CENTRAL AND WESTERN AREAS IN THE MORNING AND INTO
MIDDAY BEFORE THE HIGHER PROBABILITIES SHIFT TO THE EAST. EASTERN
AREAS SHOULD SEE THE RAIN BY LATE MORNING AND INTO THE AFTERNOON
HOURS. THE SREF IMPLIES LITTLE OR NO RAIN AFTER ABOUT MIDDAY IN
CENTRAL AND WESTERN AREAS AND BY ABOUT 3 PM IN THE EAST. POPS
CRASH AFTER 18Z IN THE EAST.
THE RAIN WILL RAPIDLY END WEST TO EAST AND THERE COULD BE PEAKS OF
SUN IN THE WEST AND CENTRAL AREAS IN THE AFTERNOON. THIS FAST
MOVING SYSTEM AND ITS REINFORCING COLD AIR WILL BE TO OUR EAST BY
LATER AFTERNOON OR EARLY EVENING.
MOST AREAS WILL SEE A 2-4 HOUR PERIOD OF RAINFALL. RAINFALL
AMOUNTS SHOULD BE IN THE 0.10 TO 0.30 INCH RANGE IN MOST AREAS.
THE RAP FAVORS HIGHER AMOUNTS IN NORTH CENTRAL AND THE SREF IS A
SPLIT DECISION WITH SOME HIGHER AMOUNTS IN IN THE SOUTH AND
FARTHER NORTH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BIG...1027MB HIGH PRESSURE SHOVES IN FROM THE WEST ON SATURDAY
NIGHT. THIS STARTS WHAT SHOULD BE AN ALMOST UNBROKEN STRING OF
COOL AND DRY WEATHER FOR THE ENTIRE LONG TERM PERIOD AND INTO
DAYS 8-PLUS. THE ONLY INKLING OF PRECIP WILL BE ON MON NIGHT AND
TUES MORNING. A WEAK FRONT MOVING DOWN FROM THE NW WILL TAP ONLY
MEAGER MOISTURES SINCE IT WILL LIE IN BETWEEN THE EARLY- WEEK HIGH
PRESSURE AND A SECOND EQUALLY DRY ANTICYCLONE MOVING IN FROM THE
UPPER GREAT LAKES AND MIDWEST. AT THE SAME TIME...THERE IS A WAVE
PROGGED TO BE SLIDING UP FROM THE GULF COAST STATES. HOWEVER...ALL
THE MODELS TAKE IT TO OUR SOUTH...GENERALLY THROUGH THE MID-
ATLANTIC STATES EARLY TUESDAY. THIS WOULD CREATE SOME RAIN/SHOWERS
ON MONDAY NIGHT AND EARLY TUESDAY. THERE MIGHT BE A BACKDOOR COLD
FRONT TRY TO MOVE DOWN AROUND THURSDAY...BUT NO MOISTURE IS TO BE
FOUND IN ITS VICINITY.
ONE POINT OF INTEREST WILL BE THE LOW TEMPERATURES SUNDAY MORNING
AND MONDAY MORNING. THE NORTHERN TIER...ESPECIALLY THE ICE BOX OF
KBFD...COULD GET INTO THE MID 30S BOTH MORNINGS - AND PERHAPS EVEN
THE LOWER 30S ON MONDAY MORNING. WHAT MIGHT BE MORE REMARKABLE IS
A POTENTIAL 30 TO 40F DIURNAL SWING ON MONDAY AS WINDS TURN TO THE
S/SW FOR THE DAYTIME BEFORE THE FRONT ARRIVES AT NIGHT/EARLY TUES.
BUT EVEN WITH THE GIANT SWING MONDAY SHOULD END UP JUST SLIGHTLY
BELOW NORMAL FOR MAXES. WELCOME AUTUMN.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
TIMING ON THE INCOMING RAIN IS THE BIG AVIATION CONCERN OVER THE
NEXT 12 HOURS. A SMALL BAND IS CURRENTLY MOVING ACROSS THE
SOUTHWESTERN TAF SITES...WHERE JST AND AOO HAVE MVFR CEILINGS. BFD
HAS GONE DOWN TO IFR AND SHOULD CONTINUE THROUGH THE MORNING.
THE SHOWERS WILL SPREAD ACROSS THE AREA BETWEEN ABOUT 09-15Z
SATURDAY MORNING ALONG WITH MVFR/IFR CONDITIONS DEVELOPING. THESE
CONDITIONS SHOULD CONTINUE UNTIL AROUND 18Z...BEFORE LIFTING AS
THE SYSTEM QUICKLY PASSES. WITH IMPROVING CONDITIONS SATURDAY
AFTERNOON.
OUTLOOK...
SUN...PATCHY AM FOG...OTHERWISE VFR.
MON...NO SIG WX.
MON NIGHT - TUE...A COLD FRONT WILL BRING REDUCED CONDITIONS WITH
SHOWERS.
WED...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...GRUMM
SHORT TERM...GRUMM/LA CORTE
LONG TERM...DANGELO
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
146 AM EDT SAT SEP 13 2014
.SYNOPSIS...
AN AREA OF LOW PRESSURE AT THE SURFACE AND DISTURBANCE ALOFT
WILL MOVE QUICKLY EAST ACROSS THE AREA SATURDAY. HIGH PRESSURE
AND FAIR WEATHER WILL RETURN ON SUNDAY. THE OVERALL PATTERN FAVORS
BELOW NORMAL TEMPERATURES FOR THE NEXT WEEK.
&&
.NEAR TERM /UNTIL 9 AM THIS MORNING/...
CLOUDS WILL SLOWLY INCREASE WEST TO EAST OVERNIGHT THEN RAPIDLY IN
THE MORNING. A FAST MOVING SHORT-WAVE OVER MICHIGAN WILL BRING A
CHANCE OF SHOWERS INTO WESTERN AREAS BEFORE 6 AM. AND SLOWLY
SPREAD INTO THE WESTERN AREAS OF OUR COUNTY WARNING AREA.
THE HIGHER RESOLUTION MODELS AND SREF FAVOR THE CHANCE OF RAINFALL
MAINLY AFTER 7 AM.
&&
.SHORT TERM /9 AM THIS MORNING THROUGH 6 PM SUNDAY/...
THE FAST MOVING AND STRONG SHORT-WAVE SHOULD BRING RAIN AND
SHOWERS TO CENTRAL AND WESTERN AREAS IN THE MORNING AND INTO
MIDDAY BEFORE THE HIGHER PROBABILITIES SHIFT TO THE EAST. EASTERN
AREAS SHOULD SEE THE RAIN BY LATE MORNING AND INTO THE AFTERNOON
HOURS. THE SREF IMPLIES LITTLE OR NO RAIN AFTER ABOUT MIDDAY IN
CENTRAL AND WESTERN AREAS AND BY ABOUT 3 PM IN THE EAST. POPS
CRASH AFTER 18Z IN THE EAST.
THE RAIN WILL RAPIDLY END WEST TO EAST AND THERE COULD BE PEAKS OF
SUN IN THE WEST AND CENTRAL AREAS IN THE AFTERNOON. THIS FAST
MOVING SYSTEM AND ITS REINFORCING COLD AIR WILL BE TO OUR EAST BY
LATER AFTERNOON OR EARLY EVENING.
MOST AREAS WILL SEE A 2-4 HOUR PERIOD OF RAINFALL. RAINFALL
AMOUNTS SHOULD BE IN THE 0.10 TO 0.30 INCH RANGE IN MOST AREAS.
THE RAP FAVORS HIGHER AMOUNTS IN NORTH CENTRAL AND THE SREF IS A
SPLIT DECISION WITH SOME HIGHER AMOUNTS IN IN THE SOUTH AND
FARTHER NORTH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
BIG...1027MB HIGH PRESSURE SHOVES IN FROM THE WEST ON SATURDAY
NIGHT. THIS STARTS WHAT SHOULD BE AN ALMOST UNBROKEN STRING OF
COOL AND DRY WEATHER FOR THE ENTIRE LONG TERM PERIOD AND INTO
DAYS 8-PLUS. THE ONLY INKLING OF PRECIP WILL BE ON MON NIGHT AND
TUES MORNING. A WEAK FRONT MOVING DOWN FROM THE NW WILL TAP ONLY
MEAGER MOISTURES SINCE IT WILL LIE IN BETWEEN THE EARLY- WEEK HIGH
PRESSURE AND A SECOND EQUALLY DRY ANTICYCLONE MOVING IN FROM THE
UPPER GREAT LAKES AND MIDWEST. AT THE SAME TIME...THERE IS A WAVE
PROGGED TO BE SLIDING UP FROM THE GULF COAST STATES. HOWEVER...ALL
THE MODELS TAKE IT TO OUR SOUTH...GENERALLY THROUGH THE MID-
ATLANTIC STATES EARLY TUESDAY. THIS WOULD CREATE SOME RAIN/SHOWERS
ON MONDAY NIGHT AND EARLY TUESDAY. THERE MIGHT BE A BACKDOOR COLD
FRONT TRY TO MOVE DOWN AROUND THURSDAY...BUT NO MOISTURE IS TO BE
FOUND IN ITS VICINITY.
ONE POINT OF INTEREST WILL BE THE LOW TEMPERATURES SUNDAY MORNING
AND MONDAY MORNING. THE NORTHERN TIER...ESPECIALLY THE ICE BOX OF
KBFD...COULD GET INTO THE MID 30S BOTH MORNINGS - AND PERHAPS EVEN
THE LOWER 30S ON MONDAY MORNING. WHAT MIGHT BE MORE REMARKABLE IS
A POTENTIAL 30 TO 40F DIURNAL SWING ON MONDAY AS WINDS TURN TO THE
S/SW FOR THE DAYTIME BEFORE THE FRONT ARRIVES AT NIGHT/EARLY TUES.
BUT EVEN WITH THE GIANT SWING MONDAY SHOULD END UP JUST SLIGHTLY
BELOW NORMAL FOR MAXES. WELCOME AUTUMN.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THE MVFR CEILINGS REMAIN OVER KBFD LATE THIS EVENING AND WILL
LIKELY REMAIN SO OVERNIGHT. ELSEWHERE SCATTERED LOW CLOUDS WILL
BE COVERED BY INCREASING MID AND HIGH CLOUDS THROUGH THE LATE
EVENING HOURS AHEAD OF ANOTHER DISTURBANCE RACING OUT OF THE UPPER
MIDWEST. EXPECT SHOWERS SPREADING ACROSS THE AREA BETWEEN ABOUT
09-15Z SATURDAY MORNING ALONG WITH MVFR/IFR CONDITIONS DEVELOPING.
THE SYSTEM BEING A FAST MOVER WILL MOVE THROUGH WITH IMPROVING
CONDITIONS SATURDAY AFTERNOON.
OUTLOOK...
SUN...PATCHY AM FOG...OTHERWISE VFR.
MON...NO SIG WX.
MON NIGHT - TUE...A COLD FRONT WILL BRING REDUCED CONDITIONS WITH
SHOWERS.
WED...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...GRUMM
SHORT TERM...GRUMM/LA CORTE
LONG TERM...DANGELO
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1151 PM CDT FRI SEP 12 2014
.AVIATION 06Z DISCUSSION... PVA WILL BE IN PLACE THROUGH 12Z OVERNIGHT
AS A WEAK MID LEVEL IMPULSE WILL BE ON APPROACH. AS A
RESULT...LOW CIGS WILL PERSIST THROUGH AT LEAST 12Z.
THEREAFTER...THE LOW CLOUDINESS WILL STILL BE RATHER TOUGH TO
DISLODGE. THE MID AND UPPER FLOW STILL CARRIES A WEAK SOUTHERLY
COMPONENT. NEVERTHELESS...CIGS SHOULD BEGIN TO LIFT SOME TOWARD
18Z WITH PARTIAL CLEARING WEST BY 00Z.
OTW...ISOLATED SHOWERS HERE AND THERE WILL BE POSSIBLE UNTIL 12Z.
HOWEVER...THE EXPECTED COVERAGE DOES NOT WARRANT THE USAGE OF
VCNTY...TEMPO OR PROB GROUPS.
LOOK FOR CLOUDINESS TO BEGIN TO DECREASE FROM WEST TO EAST AFT
18Z.
&&
.PREV DISCUSSION... /ISSUED 725 PM CDT FRI SEP 12 2014/
UPDATE...
LATEST SURFACE OBS AND SATELLITE IMAGERY SHOWS LOW CLOUDS
CONTINUE TO BLANKET THE MID STATE...AND ACTUALLY EXTEND NORTHWARD
ALL THE WAY INTO CANADA SO THEY WONT BE GOING ANYWHERE ANYTIME
SOON. WATER VAPOR IMAGERY THIS EVENING DEPICTS A STRONG TROUGH
DIGGING SOUTHWARD INTO IOWA AND MISSOURI. AS THIS TROUGH SWINGS
THROUGH THE OHIO AND TENNESSEE VALLEYS OVERNIGHT...EXPECT A FEW
LIGHT SHOWERS AND SPRINKLES TO BREAK OUT ACROSS THE MID STATE
SIMILAR TO THE MOST RECENT HRRR MODEL RUNS. ALSO ANTICIPATE SOME
PATCHY FOG DEVELOPMENT IN THE HIGHER TERRAIN AREAS OF EASTERN
ZONES AS DEWPOINT DEPRESSIONS LOWER OVERNIGHT. DESPITE EXTENSIVE
CLOUD COVER...CAA WILL INCREASE OVERNIGHT WITH DRIER AIR
ADVECTING IN FROM THE NORTH AT THE SURFACE...WHICH SHOULD ALLOW
TEMPS TO FALL INTO THE UPPER 50S AND LOWER 60S FOR LOWS. CURRENT
FORECAST FOR TONIGHT ALREADY HAS CLOUDS...POPS...AND TEMPS WELL
HANDLED...AND ONLY MADE MINOR CHANGES FOR THE OVERNIGHT PERIOD.
SHAMBURGER
PREV DISCUSSION... /ISSUED 514 PM CDT FRI SEP 12 2014/
AVIATION 00Z DISCUSSION...
PVA WILL BE IN PLACE THROUGH 12Z OVERNIGHT AS A WEAK MID LEVEL IMPULSE
WILL BE ON APPROACH. AS A RESULT...LOW CIGS WILL PERSIST THROUGH
AT LEAST 12Z. THEREAFTER...THE LOW CLOUDINESS WILL STILL BE RATHER
TOUGH TO DISLODGE. THE MID AND UPPER FLOW STILL CARRIES A WEAK
SOUTHERLY COMPONENT. NEVERTHELESS...CIGS SHOULD BEGIN TO LIFT SOME
TOWARD 18Z WITH PARTIAL CLEARING WEST BY 00Z.
OTW...ISOLATED SHOWERS HERE AND THERE WILL BE POSSIBLE UNTIL 12Z.
HOWEVER...THE EXPECTED COVERAGE DOES NOT WARRANT THE USAGE OF
VCNTY...TEMPO OR PROB GROUPS.
PREV DISCUSSION... /ISSUED 256 PM CDT FRI SEP 12 2014/
DISCUSSION...IT WAS A CLOUDY DAY ACROSS MID TN WITH TEMPERATURES
MAINLY IN THE 70S...WHICH IS 5 TO 10 DEGREES COOLER THAN NORMAL. A
COLD FRONT HAD SETTLED WELL TO OUR SOUTHEAST. HIGH PRESSURE WAS
LOCATED WELL TO OUR NORTHWEST...CENTERED OVER THE NORTHERN PLAINS.
POST FRONTAL MOISTURE LINGERED OVER A WIDE AREA ...AND THIS
MOISTURE AND CLOUDINESS WILL REMAIN FOR A WHILE.
FOR TONIGHT...CLOUDY SKIES MAY EVENTUALLY PRODUCE A FEW LIGHT
SHOWERS OR PATCHY DRIZZLE AS A TROUGH AXIS PASSES ACROSS THE
REGION. THE CLOUDS WILL LOWER...AND SHOULD KEEP ANY FOG FORMATION
FROM BEING VERY DENSE. LOWS WILL BE A FEW DEGREES COOLER THAN
LAST NIGHT.
ON SATURDAY...MODELS SHOW A SMALL CHANCE FOR MORNING SHOWERS
PLATEAU...THEN DECREASING MOISTURE FROM NW TO SE. WE THINK CLOUDS
COULD BE STUBBORN...SO EXPECT OVERCAST SKIES ALL ZONES THROUGH
MIDDAY...THEN PARTIAL CLEARING GRADUALLY WORKING FROM NW TO SE
ACROSS THE MID STATE THROUGH THE AFTERNOON. HIGH TEMPS WILL AGAIN
BE QUITE PLEASANT...IN THE 70S. NORTH BREEZES WILL PICK UP A BIT
TO HELP THE CLEARING TREND. WINDS WILL REACH 10-20 MPH IN THE
EARLY AFTERNOON.
DRY WX WILL CONTINUE THROUGH THE REST OF THE WEEKEND. SATURDAY NIGHT
WILL BE A LITTLE CHILLY...WITH LOWS MAINLY LOWER 50S...BUT SOME
40S POSSIBLE AS WELL. SUNDAY WILL BE MAINLY SUNNY AND TEMPS WILL
RECOVER TO THE UPPER 70S.
LOOKING AHEAD...NEXT WEEK SHOULD BE QUIET IN THE WX DEPARTMENT.
A COUPLE OF WAVES AND FRONTS WILL SWING DOWN IN THE NORTHWEST
FLOW...BUT NO MAJOR RAINFALL OR TEMPERATURE ANOMALIES ARE EXPECTED.
RIGHT NOW...IT LOOKS LIKE THE STRONGEST SYSTEM WILL MOVE THROUGH
TUESDAY NIGHT...AND JUST INCLUDING 20 POPS AT THAT TIME. LOWS NEXT
WEEK WILL BE MOSTLY IN THE UPPER 50S TO AROUND 60...WITH HIGHS IN
THE MID 70S TO LOWER 80S.
13
PREV DISCUSSION... /ISSUED 1233 PM CDT FRI SEP 12 2014/
AVIATION...
MVFR-IFR CIGS ARE EXPECTED TO IMPROVE SLIGHTLY THROUGH THIS
AFTERNOON...BUT PERSISTENT VFR CIGS ARE NOT EXPECTED IN THE NEAR
TERM. WINDS WILL BE STEADY FROM THE NORTH TO NORTHWEST THROUGH THE
NIGHT SO VIS REDUCTIONS ARE NOT ANTICIPATED AT BNA OR CKV. FOR CSV
EXPECT IFR-LIFR VIS AND CIGS AGAIN DURING THE OVERNIGHT...WITH
CONDITIONS IMPROVING AT ALL THREE TAF SITES AFTER 14Z TOMORROW
UNDER A STEADY NORTH TO NORTHEASTERLY FLOW.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
235 AM CDT SAT SEP 13 2014
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 235 AM CDT SAT SEP 13 2014
WATER VAPOR IMAGERY/RAP 500MB ANALYSIS SHOWING DEEP MID-LEVEL TROUGH
THAT GAVE THE AREA A CHILLY DAMP FRIDAY NOW OVER UPPER MI. RADAR
MOSAIC SHOWING LINGERING RAIN FROM CENTRAL UPPER MI INTO OVER FAR
EASTERN WI. IR SATELLITE SHOWED BULK OF LOW CLOUDS ASSOCIATED WITH
THIS TROUGH NOW NORTHEAST OF I-94. SURFACE HIGH PRESSURE/CLEARING
WAS WORKING INTO THE FORECAST AREA. ARX WEBCAM SHOWING EXTENSIVE
MISSISSIPPI RIVER VALLEY FOG WITH THE CLEARING/LIGHT WINDS. FOG WAS
HIT AND MISS ACROSS THE REST OF THE FORECAST AREA. OTHERWISE...
TEMPERATURES AS OF 2 AM WERE IN THE MIDDLE 30S TO MIDDLE 40S.
PLAN ON CONTINUING FROST ADVISORY THROUGH 8 AM THIS MORNING AS
TEMPERATURES FALL INTO THE LOWER/MIDDLE 30S. OTHERWISE...PLAN ON A
DRY/COOL SATURDAY AS A RIDGE OF HIGH PRESSURE PASSES OVERHEAD. LOOK
FOR HIGHS IN THE 55-65 DEGREE RANGE WHICH IS SOME 10-15 DEGREES
BELOW THE NORMAL...BUT MUCH BETTER THAN THE CHILLY CONDITIONS SEEN
ON FRIDAY.
LIGHT SOUTH WINDS/WARM AIR ADVECTION WILL THEN SET UP ACROSS THE
AREA TONIGHT AS THE HIGH MOVES INTO THE GREAT LAKES REGION AND A MID-
LEVEL/SURFACE TROUGH PUSHES FROM THE NORTHERN PLAINS INTO MN. SOME
MID/HIGH CLOUD WILL ALSO BE SEEN MAINLY NORTH OF I-94 IN THE WARM
AIR ADVECTION. LOOK FOR LOWS IN THE UPPER 30S TO THE LOWER 40S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 235 AM CDT SAT SEP 13 2014
MID-LEVEL/SURFACE TROUGH PUSHES INTO THE AREA ON SUNDAY. MODELS
SHOWING WEAK 850MB MOISTURE TRANSPORT AND BEST SURFACE CONVERGENCE
NORTHEAST OF I-94 FOR A CHANCE OF SHOWERS IN THE AFTERNOON. THE REST
OF THE AREA LOOKS TO REMAIN DRY. OTHERWISE...PLAN ON ANOTHER EARLY
AUTUMN-LIKE DAY WITH HIGHS TOPPING OFF IN THE 60S.
SHOWER CHANCES WILL SPREAD ACROSS THE REST OF THE AREA SUNDAY NIGHT
AS THE TROUGH SLIPS SOUTHEAST. LOOK FOR LOWS IN THE 40S TO LOWER
50S. SHOWER CHANCES LOOK TO LINGER INTO MONDAY AS ANOTHER MID-LEVEL
TROUGH DROPS INTO THE AREA FROM THE NORTHERN PLAINS. THIS TROUGH
INTERACTS WITH THE BAROCLINIC ZONE ACROSS THE SOUTH WITH WEAK
FRONTOGENESIS IS NOTED IN THE 850-500MB LAYER PER THE NAM. THE GFS
IS A BIT STRONGER WITH THIS. WILL GO WITH A 20-50 POPS FOR NOW
MAINLY ALONG/SOUTH OF I-90. PLAN ON HIGHS MONDAY GENERALLY IN THE 60-
65 DEGREE RANGE.
FOR THE PERIOD TUESDAY THROUGH FRIDAY...
COOL/DRY NORTHWEST FLOW ALOFT WILL PREVAIL TUESDAY INTO WEDNESDAY
WITH HIGHS IN THE 60S AND LOWS IN THE UPPER 30S TO MIDDLE 40S.
SOME WARMING LOOKS TO TAKE PLACE THURSDAY INTO FRIDAY AS HIGH
PRESSURE MOVES OFF TO THE EAST AND A TROUGH MAKES ITS WAY OUT OF THE
INTERMOUNTAIN WEST INTO THE PLAINS. INCREASING WARM AIR
ADVECTION/MOISTURE TRANSPORT INTO THE REGION MAY PUSH A FEW SHOWERS
INTO THE AREA LATER THURSDAY NIGHT INTO FRIDAY. LOOK FOR HIGHS
THURSDAY IN THE 60S AND MID 60S TO THE LOWER 70S ON FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI SEP 12 2014
WITH CLOUDS HOLDING T/TD SPREADS CLOSE THROUGH THE DAY...AND
CLEARING SKIES JUST IN TIME FOR NIGHTTIME...ITS A FAVORABLE SETUP
FOR DIURNAL COOLING INDUCED RIVER VALLEY FOG. NOT AS MUCH T/TD
SPREAD TO MAKEUP - ONLY 3 DEGREES AT 04Z. SFC WINDS WILL BE LIGHT
THROUGH THE NIGHT. HOWEVER...A SIGNIFICANT DRAWBACK WILL BE THE
DEPTH OF THE LIGHT WIND LAYER. RAP BUFKIT SOUNDINGS CONTINUE TO
BRING 10+ KTS OF WIND BY 300 FT FOR MOST OF THE NIGHT. THE NAM HAS A
SLIGHTLY DEEPER LIGHT WIND FOR THE FIRST PART OF THE
OVERNIGHT...DECREASING BEFORE 12Z. GENERALLY - THE SHALLOWER THE
LIGHT WIND LAYER...THE LESS FAVORABLE FOR DENSE FOG. CLOUDS AREN/T
COMPLETELY CLEAR EITHER...WITH SCATTERED PATCHES MOVING OVERHEAD.
CERTAINLY...SOME VSBY RESTRICTIONS ARE LIKELY...AND COULD SEE
THICKER FOG/STRATUS BANK SITTING ON THE MISSISSIPPI RIVER...BUT
UNSURE IF IT WILL SPREAD ACROSS KLSE. THIS COULD BE A SCENARIO WHERE
VSBYS DO DROP TO 1/4SM BRIEFLY...THEN BACK UP TO P6SM...THEN
2SM...AS FOG SLOSHES AROUND. CONFIDENCE LOW IN HOW THIS WILL
PLAYOUT...SO WILL LIKELY HOLD WITH MVFR VSBYS AND BCFG FOR NOW.
SOMETHING TO WATCH CLOSELY TONIGHT.
HIGH PRESSURE BUILDS IN SATURDAY...AND WILL RESULT IN VFR CONDITIONS
OUTSIDE OF THE EARLY MORNING FOG POTENTIAL. WINDS WILL GRADUALLY
SWING FROM WEST TO SOUTHWEST. LATER SAT NIGHT...SOME CIGS NEAR 4KFT
COULD RETURN AS LOW LEVEL WARM AIR ADVECTION AND WEAK MOISTURE
TRANSPORT LEAD A SHORTWAVE MOVING EAST ACROSS THE NORTHERN PLAINS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR WIZ017-029-033-
034-042>044.
MN...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR MNZ086-087-094-
095.
IA...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR IAZ008>010-018-
019-029.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT FRI SEP 12 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 257 PM CDT FRI SEP 12 2014
MAIN FORECAST CONCERNS ARE FROST AND FOG POTENTIAL TONIGHT.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING VIGOROUS SHORTWAVE
TROUGH OVER THE NORTHERN PLAINS. MOSAIC RADAR INDICATING
FRONTOGENETICAL BAND OF RAIN EXTENDING FROM NORTHEAST WISCONSIN INTO
NORTHEAST IOWA PER 12.15Z RAP 700-600MB FN VECTOR CONVERGENCE.
ALSO...MOSAIC RADAR SHOWING DIURNALLY DRIVEN SCATTERED SHOWERS OVER
CENTRAL MINNESOTA UNDERNEATH MAIN SHORTWAVE TROUGH.
TONIGHT...SHORTWAVE TROUGH AND ASSOCIATED LOW LEVEL MOISTURE/RAIN
PROGGED TO PUSH QUICKLY EAST INTO MICHIGAN THIS EVENING PER THE
LATEST 12.12Z GFS/NAM AND 12.15Z RAP RELATIVE HUMIDITY FIELDS. THIS
IS EVIDENT PER LATEST VISIBLE SATELLITE IMAGERY SHOWING DIURNAL
CUMULUS FIELD WEST OF A LINE FROM FAIRMONT MINNESOTA TO NEAR DULUTH
MINNESOTA. THIS CUMULUS FIELD WILL QUICKLY EVAPORATE DUE TO LOSS OF
DAYTIME HEATING THIS EVENING AND ALLOW SKIES TO CLEAR WEST TO EAST
ACROSS THE FORECAST AREA. SURFACE RIDGE BUILDS INTO THE FORECAST
AREA BY 06Z AND PRODUCE CALM WINDS AND DRIER AIRMASS TO ADVECT IN.
TEMPERATURES WILL BE ABLE TO FALL RAPIDLY INTO THE 30S AND THE UPPER
20S IN THE COLD SPOTS OF CENTRAL WISCONSIN. FOR THIS...A FROST
ADVISORY WILL BE IN EFFECT FOR PORTIONS OF SOUTHEAST
MINNESOTA...NORTHEAST IOWA AND CENTRAL WISCONSIN TONIGHT. IN
ADDITION...THE COMBINATION OF RAIN TODAY...CALM WINDS AND INVERSION
DEVELOPING TONIGHT PER BUFKIT SOUNDINGS...AREAS OF FOG WILL DEVELOP
IN RIVER VALLEYS AND PARTS OF CENTRAL WISCONSIN AFTER 06Z.
DRY WEATHER CONDITIONS AND UNSEASONABLY COOL TEMPERATURES WILL
PREVAIL ACROSS THE AREA SATURDAY...AS SURFACE RIDGE REMAINS IN
CONTROL.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 257 PM CDT FRI SEP 12 2014
WARMER AIR ADVECTS INTO THE FORECAST AREA SUNDAY OUT AHEAD OF NEXT
SHORTWAVE TROUGH TO AFFECT THE REGION. TEMPERATURES WILL BE A FEW
DEGREES WARMER AND SLIGHTLY BELOW NORMAL.
NEXT CONCERN IS SHORTWAVE TROUGH MOVING OVER THE GREAT LAKES REGION
EMBEDDED IN THE WEST TO NORTHWEST FLOW SUNDAY NIGHT INTO MONDAY.
BOTH THE 12.12Z GFS/NAM SHOW STRONG PV ADVECTION/QG FORCING AND
FN CONVERGENCE FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST
AREA. SOME SLIGHT DIFFERENCES OCCUR WITH THE PLACEMENT AND TIMING
OF SURFACE FEATURES BETWEEN THE 12.12Z GFS/NAM/ECMWF. WITH THE
MODELS CONTINUE TO SHOW DECENT DYNAMIC FORCING/LIFT IN ASSOCIATED
WITH SHORTWAVE TROUGH...WILL MAINTAIN PRECIPITATION CHANCES SUNDAY
INTO MONDAY MAINLY FOR THE SOUTHERN HALF OF THE FORECAST AREA.
MAIN FORECAST CONCERN ARE PRECIPITATION CHANCES FRIDAY...OTHERWISE
TEMPERATURES TUESDAY THROUGH FRIDAY. THE 12.12Z GFS/GEM/ECMWF
CONTINUE TO HAVE GOOD RUN TO RUN CONSISTENCY IN DIGGING UPPER LEVEL
TROUGH OVER THE NORTHEAST UNITED STATES AND GREAT LAKES REGION AND
SURFACE RIDGE DOMINATING THE UPPER MIDWEST TUESDAY THROUGH THURSDAY.
WITH SUBSIDENCE OVER THE FORECAST AREA...DUE TO SURFACE RIDGE...DRY
WEATHER CONDITIONS CAN BE EXPECTED ACROSS THE FORECAST AREA DURING
THIS TIME FRAME. TEMPERATURES SHOULD BE NEAR OR SLIGHTLY BELOW
NORMAL TUESDAY THROUGH THURSDAY...AS THE 12.00Z GFS/GEM/ECMWF
INDICATE 850MB TEMPERATURES RANGING FROM PLUS 5 TO PLUS 10 DEGREES
CELSIUS AND 12.12Z GEFS SHOW STANDARD ANOMALIES OF MINUS 0.5 TO
MINUS 1 DEGREE CELSIUS. SIGNIFICANT DIFFERENCES SHOW UP BETWEEN THE
12.12Z GFS/ECMWF FRIDAY...AS THE 12.12Z GFS MORE AMPLIFIED WITH
UPPER LEVEL RIDGE OVER THE UPPER MIDWEST THAN THE ECMWF AND THE
12.12Z ECMWF IS SLOWER IN PROGRESSING THE UPPER LEVEL RIDGE INTO THE
UPPER MIDWEST AND GREAT LAKES REGION. THIS HAS IMPACTS ON HOW FAST
WARMER AIR ADVECTS INTO THE REGION AND TIMING OF SURFACE WARM FRONT
INTO THE FORECAST AREA. THIS SURFACE WARM FRONT WILL BE THE FOCUS
OF PRECIPITATION CHANCES FRIDAY...WITH BOTH THE 12.12Z GFS/ECMWF
INDICATE DECENT 850MB MOISTURE TRANSPORT AND CONVERGENCE IN
ASSOCIATION WITH IMPULSE OVER THE NORTHERN PLAINS AND NORTHERN
ROCKIES. CONFIDENCE IN FORECAST ON FRIDAY IS LOW DUE TO TIMING AND
STRENGTH OF UPPER LEVEL RIDGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI SEP 12 2014
WITH CLOUDS HOLDING T/TD SPREADS CLOSE THROUGH THE DAY...AND
CLEARING SKIES JUST IN TIME FOR NIGHTTIME...ITS A FAVORABLE SETUP
FOR DIURNAL COOLING INDUCED RIVER VALLEY FOG. NOT AS MUCH T/TD
SPREAD TO MAKEUP - ONLY 3 DEGREES AT 04Z. SFC WINDS WILL BE LIGHT
THROUGH THE NIGHT. HOWEVER...A SIGNIFICANT DRAWBACK WILL BE THE
DEPTH OF THE LIGHT WIND LAYER. RAP BUFKIT SOUNDINGS CONTINUE TO
BRING 10+ KTS OF WIND BY 300 FT FOR MOST OF THE NIGHT. THE NAM HAS A
SLIGHTLY DEEPER LIGHT WIND FOR THE FIRST PART OF THE
OVERNIGHT...DECREASING BEFORE 12Z. GENERALLY - THE SHALLOWER THE
LIGHT WIND LAYER...THE LESS FAVORABLE FOR DENSE FOG. CLOUDS AREN/T
COMPLETELY CLEAR EITHER...WITH SCATTERED PATCHES MOVING OVERHEAD.
CERTAINLY...SOME VSBY RESTRICTIONS ARE LIKELY...AND COULD SEE
THICKER FOG/STRATUS BANK SITTING ON THE MISSISSIPPI RIVER...BUT
UNSURE IF IT WILL SPREAD ACROSS KLSE. THIS COULD BE A SCENARIO WHERE
VSBYS DO DROP TO 1/4SM BRIEFLY...THEN BACK UP TO P6SM...THEN
2SM...AS FOG SLOSHES AROUND. CONFIDENCE LOW IN HOW THIS WILL
PLAYOUT...SO WILL LIKELY HOLD WITH MVFR VSBYS AND BCFG FOR NOW.
SOMETHING TO WATCH CLOSELY TONIGHT.
HIGH PRESSURE BUILDS IN SATURDAY...AND WILL RESULT IN VFR CONDITIONS
OUTSIDE OF THE EARLY MORNING FOG POTENTIAL. WINDS WILL GRADUALLY
SWING FROM WEST TO SOUTHWEST. LATER SAT NIGHT...SOME CIGS NEAR 4KFT
COULD RETURN AS LOW LEVEL WARM AIR ADVECTION AND WEAK MOISTURE
TRANSPORT LEAD A SHORTWAVE MOVING EAST ACROSS THE NORTHERN PLAINS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR WIZ017-029-033-
034-042>044.
MN...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR MNZ086-087-094-
095.
IA...FROST ADVISORY FROM 3 AM TO 8 AM CDT SATURDAY FOR IAZ008>010-018-
019-029.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS TUCSON AZ
300 AM MST MON SEP 15 2014
.SYNOPSIS...ISOLATED THUNDERSTORMS TODAY WITH SOME STORMS OVERNIGHT.
THEN...WITH THE INFLUENCE FROM ODILE THE CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL INCREASE GREATLY DURING THE UPCOMING WEEK AS
MOISTURE INCREASES ACROSS THE AREA FROM THE SOUTH. THERE IS A
POTENTIAL FOR PERIODS OF SIGNIFICANT RAINFALL FROM TUESDAY AFTERNOON
THROUGH THURSDAY NIGHT OR FRIDAY.
&&
.DISCUSSION...SUFFICIENT MOISTURE ACROSS SOUTHERN ARIZONA WITH
PRECIPITABLE WATER AROUND 1.3 INCHES WITH MODESTLY WARM MID LEVEL
TEMPERATURES. AS IT STANDS IT WOULD BE ANOTHER MEAGER CONVECTIVE
DAY. A COUPLE OF FACTORS SHOWING MORE PROMISE LATER TODAY AND
TONIGHT WITH MOISTURE INCREASING THROUGH THE MID GULF AND SOUTHERN
TO MID SONORA. THIS FETCH OF DEEP MOISTURE WILL PUSH INTO SOUTHERN
ARIZONA OVER THE NEXT 24 HOURS WITH HRRR STREAMLINES FORECASTING A
STRONG RESPONSE AT THE SURFACE AS WELL TODAY. WE SHOULD SEE
INCREASING COVERAGE THIS AFTERNOON...BUT STILL MAINLY SOUTH AND
SOUTHWEST OF TUCSON. ECMWF KEYS ON AN IMPULSE PUSHING UP FROM SONORA
THROUGH EASTERN ZONES TONIGHT INTO TUESDAY WITH A FOCUS ON COCHISE
AND SANTA CRUZ COUNTIES TONIGHT.
MOISTURE RAMPS UP INTO TUESDAY WITH A STRONG THUNDERSTORM AFTERNOON
SHAPING UP ALONG WITH POSSIBLE ORGANIZED CONVECTIVE OUTFLOWS AND
LOCALLY HEAVY RAIN UNDER STRONGER CELLS. THE ONLY THING THAT LOOKS
LIKE IT COULD KEEP TUESDAY AFTERNOON FROM BEING ACTIVE IS WITH THE
SHARP MOISTURE GRADIENT WE COULD ACTUALLY SEE INCREASING SHOWER AND
THUNDERSTORM ACTIVITY EARLY TO MID THURSDAY MORNING TO TAKE THE EDGE
OF THE POTENTIAL INSTABILITY AND WIND PROFILE COMBO TUE AFTERNOON.
AFTER THAT ODILE AND THE DEVELOPING WEST COAST TROUGH DICTATE OUR
WEATHER. MAJOR HURRICANE ODILE SLAMMED INTO FAR SOUTHERN BAJA
PENINSULA OVER THE LAST SEVERAL HOURS WITH A 2 AM FORECAST TRACK
THAT BRINGS THE REMNANT INTO THE FAR NORTHERN GULF OF CALIFORNIA
THURSDAY AS A DEPRESSION. AT THAT POINT IT COULD TRACK RIGHT OVER US
AND COMPLETE A SOLID DRENCHING FOR MUCH OF SE AZ. WE`LL NEED TO
WATCH HOW WELL SHE MAINTAINS HER INTENSITY AND CONTINUE TO MONITOR
HER TRACK AND POTENTIAL INTERACTION WITH THE TROUGH...BUT AT THIS
POINT IT LOOKS LIKE A WET WEEK. OUR FOCUS AFTER THE INITIAL SHOT OF
MOISTURE EARLY TO LATE TUESDAY IS ON 18Z WED TO 06Z FRI (LATER
WEDNESDAY AFTERNOON THROUGH THURSDAY NIGHT) TIME PERIOD WITH THE
TRACK OF THE REMNANT CIRCULATION. HOWEVER...ANY TIME AFTER MONDAY
NIGHT WE COULD SEE ONE PERIOD OF LOCALLY HEAVY RAINFALL OR SEVERAL.
OUR CURRENT 5 DAY STORM TOTAL QPF RANGES FROM .75 TO 1.75 INCHES IN
VALLEY LOCATIONS AND 1.5 TO 3.5 INCHES IN MOUNTAIN LOCATIONS WHICH
IS IN DECENT AGREEMENT WITH WPC ESTIMATES. IT`S LIKELY TO BE A BUSY
WEEK BUT THERE WILL ALSO BE SOME DOWN PERIODS IN BETWEEN OUR BEST
PRECIP CHANCES.
&&
.AVIATION...VALID THRU 16/10Z.
TIGHTENED PRESSURE GRADIENT OVER THE EASTERN HALF OF THE AREA WILL
MAINTAIN EASTERLY FLOW TODAY FOR MOST TERMINALS. THE GRADIENT WILL
RELAX DURING THE LATE AFTERNOON HOURS WITH THE WINDS DECREASING A
BIT AS A RESULT. MOSTLY CLEAR SKIES WITH ONLY ISOLATED CONVECTION
EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING. CHANCES MAY INCREASE
OVERNIGHT BEFORE A STRONG INCREASE IN SHOWER AND THUNDERSTORM
CHANCES MOST OF THE REST OF THE WEEK. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THE EASTERLY BREEZE AFFECTING THE EASTERN HALF OF
THE AREA IS NOW EXPECTED TO CONTINUE THROUGH MUCH OF TODAY. IT
WILL EASE UP DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
ISOLATED TO SCATTERED CONVECTION DEVELOPING THIS
AFTERNOON...ESPECIALLY SOUTH OF TUCSON AND NEAR MOUNTAINS.
THEN ALL FOCUS GOES TO THE INCREASE MOISTURE AS MAJOR HURRICANE
ODILE EDGES NORTHWARD. DEEPER MOISTURE IS EXPECTED TO BE FORCED
NORTH ACROSS THE AREA BY MONDAY EVENING WITH CONVECTION POSSIBLE
MONDAY NIGHT. THEN THE DEEP MOISTURE WILL BE IN PLACE THROUGH
FRIDAY FOR AN ENHANCED THREAT OF SHOWERS AND THUNDERSTORMS WITH A
POTENTIAL FOR LOCALLY HEAVY RAINS. TIMING FOR THE MOISTURE MOVING
OUT OF THE REGION REMAINS QUESTIONABLE AT THIS TIME...THOUGH WILL
LIKELY SEE A DOWNWARD BY THE WEEKEND AS UPPER LEVEL TROF PUSHES THRU
THE NORTHERN HALF OF THE STATE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER/MEADOWS/CARLAW
AREA FORECAST DISCUSSION...UPDATED
NWS MELBOURNE FL
420 AM EDT MON SEP 15 2014
.DISCUSSION...
TODAY-TONIGHT...
WEAK ATLANTIC RIDGE WILL EXTEND ACROSS CENTRAL FLORIDA AT THE
SURFACE...PRODUCING LIGHT LOW LEVEL WINDS ACROSS THE REGION. THIS
WILL ALLOW THE EAST COAST SEA BREEZE TO DEVELOP AND MOVE INLAND
THROUGH THE AFTERNOON WITH A MORE INLAND PUSH EXPECTED SOUTH OF THE
CAPE. MOISTURE LOOKS TO BE SLIGHTLY GREATER TOWARD EAST CENTRAL
FLORIDA...ESPECIALLY OVER NRN AREAS AS DRIER AIR ACCOMPANIES A
850-700MB RIDGE BUILDING W-NW OVER WEST CENTRAL FLORIDA.
THE 00Z MOS POPS DIFFER SIGNIFICANTLY BETWEEN GFS AND NAM GUIDANCE
WITH GFS VALUES MUCH LOWER ONLY SHOWING RAIN CHANCES AROUND 20
PERCENT MOST LOCATIONS. HOWEVER LATEST HRRR RUN SHOWING SIGNS OF AT
LEAST ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT BETWEEN THE SEA
BREEZE BOUNDARIES INTO THE AFTERNOON. HAVE THEREFORE LEANED TOWARD A
BLEND BETWEEN THE TWO MODELS WITH GREATEST RAIN CHANCES...UP TO 40
PERCENT...FROM THE ORLANDO AREA NORTHWARD WHERE HIGHER MOISTURE WILL
EXIST. HIGHS WILL CONTINUE TO RANGE FROM THE UPPER 80S ALONG THE
COAST INTO THE LOW 90S ACROSS THE INTERIOR.
LINGERING CONVECTION FROM LATE DAY SEA BREEZE COLLISIONS OVER THE
INTERIOR MAY BE ABLE TO PUSH BACK TOWARD THE COAST...ESPECIALLY
NORTH OF MELBOURNE INTO THE EVENING. THIS ACTIVITY IS EXPECTED TO
DIMINISH INTO TONIGHT WITH RAIN CHANCES ENDING BY MIDNIGHT. TEMPS
WILL FALL INTO THE LOW TO MID 70S WITH SKIES PARTLY CLOUDY TO MOSTLY
CLEAR.
TUE-WED...
A COUPLED H30-H20 JET STREAK OVER THE GREAT LAKES/MID WEST WILL
PRODUCE STRONG UPR LVL DIVERGENCE OVER THE MID AND DEEP SOUTH.
THIS...IN TURN WILL INDUCE A BROAD SFC LOW TO FORM ALONG A STALLED
FRNTL BNDRY OVER THE DEEP SOUTH THAT WILL SLOWLY CRANK THE FRNT INTO
CENTRAL FL. A RELATIVELY WET PD THRU MIDWEEK WILL RESULT AS MOISTURE
POOLING WITHIN THE FRONTAL TROF PROVIDES THE FUEL NECESSARY FOR
SCT/NMRS SHRAS AND TSRAS ACRS THE CWA.
RUC40 REGIONAL ANALYSIS SHOWS SPORADIC POCKETS OF MID LVL VORTICITY
OVER THE GOMEX. THERE IS A POCKET OF COOL H50 AIR EXTENDING FROM NRN
CUBA ACRS THE BAHAMA BANK...TEMPS -8C/-9C...THAT WILL ALLOW SOME
WEAK MID LVL COOLING AS THE FRONT NUDGES ITS WAY S. HOWEVER...
H70-H50 LAPSE RATES ASSOCD WITH THIS AIRMASS ARE MODERATE AT BEST
WITH THE STEEPEST READINGS ARND 6.5C/KM.
INCREASING WRLY FLOW WILL PREVAIL AS THE APPROACHING TROF INTERACTS
WITH THE RETREATING ATLC RIDGE...A FLOW REGIME THAT USUALLY FAVORS
THE E FL PENINSULA FOR DAILY CONVECTION. WEAKER PGRAD ON TUE AS LOW
PRES ORGANIZES WILL ALLOW THE EAST COAST SEABREEZE TO FORM...WHILE
WRLY H85-H50 STEERING FLOW AOB 10KTS WILL KEEP IT PINNED NEAR THE
COAST. SLOW STORM MOTION ON TUE COMBINED WITH WEAKER FORCING AND
LOWER MOISTURE WILL KEEP COVERAGE AOB 50PCT...INCREASING TO 50/60PCT
WED AS THE FRONT DRIFTS THRU CENTRAL FL.
MAX TEMPS NEAR AVG (U80S/L90S) AS THE USUALLY WARMER WRLY FLOW IS
COUNTERED BY INCREASING CLOUD/PRECIP COVERAGE. MIN TEMPS ABV AVG
(L/M70S) AS INCREASING WRLY FLOW KEEPS THE AIRMASS MIXED WHILE CLOUD
COVER PROVIDES A BLANKETING EFFECT.
THU-SUN...
FRNTL BNDRY SHOULD STALL OVER S FL AS THE POST FRONTAL HI PRES
RIDGE WORKS ITS WAY ACRS THE ERN CONUS. SFC/STEERING WINDS WILL
SHIFT TO A N/NERLY DIRECTION WHICH WILL ALLOW A DRIER AND MORE
STABLE MID LVL AIR MASS TO PUSH INTO THE CWA...RESULTING IN LOWER
PRECIP CHANCES THRU THE LATTER HALF OF THE WEEK. NO SIG COOL AIR
ADVECTION...HOWEVER...AS THE FRONT WILL BE ORIGINATING FROM THE DEEP
SOUTH TO BEGIN WITH. FURTHERMORE...WITH SFC/LOW LVL WINDS SHIFTING
ONSHORE...OCEAN MODIFICATION WILL OCCUR QUICKLY. MAX/MIN TEMPS NOT
EXPECTED TO DEVIATE FROM CLIMO AVGS BY MORE THAN 3F DEG.
&&
.AVIATION...
EAST COAST SEA BREEZE WILL DEVELOP AND MOVE INLAND THROUGH THE
AFTERNOON WITH A GREATER INLAND MOVEMENT EXPECTED SOUTH OF THE CAPE.
ISOLATED TO SCATTERED SHRA/TSRA WILL DEVELOP ALONG AND AHEAD OF THIS
BOUNDARY WITH BEST CHANCE FOR SHOWER/STORM DEVELOPMENT FROM ORLANDO
NORTHWARD TOWARD MID TO LATE AFTERNOON AS SEA BREEZE BOUNDARIES
COLLIDE ACROSS THE INTERIOR. LINGERING CONVECTION INTO THE EVENING
WILL DIMINISH BY MIDNIGHT.
&&
.MARINE...
TODAY/TONIGHT...WEAK RIDGE ACROSS THE AREA WILL PRODUCE LIGHTER
WINDS ACROSS THE COASTAL WATERS WITH VARIABLE DIRECTIONS...
ESPECIALLY THROUGH THE MORNING. WINDS NEAR THE COAST WILL INCREASE
UP TO 10 KNOTS OUT OF THE E/SE AS THE SEA BREEZE DEVELOPS AND MOVES
INLAND INTO THE AFTERNOON AND THEN DECREASE INTO THE EVENING OUT OF
THE S/SE SOUTH OF THE CAPE AND S/SW NORTH.
SWAN GUIDANCE CONTINUES TO BE EXTREMELY TOO HIGH WITH WAVE HEIGHTS
AND HAVE THEREFORE WENT WITH THE MORE REASONABLE WNAWAVE VALUES WITH
SEAS RANGING FROM 1-2 FEET.
TUE-TUE NIGHT...WEAK SFC/LOW LVL PGRAD WILL REMAIN IN PLACE WITH THE
ATLC RIDGE AXIS DRAPED OVER THE CENTRAL AND SOUTH FL PENINSULA.
LIGHT TO GENTLE WRLY BREEZE BCMG ONSHORE BY EARLY AFTN AS THE EAST
COAST SEA BREEZE DVLPS AND PUSHES INLAND...BCMG S/SW AFT SUNSET.
SEAS 2FT NEARSHORE THRU THE DAY...BCMG 2-3FT NEARSHORE AND 3-4FT
OFFSHORE AS SWELLS FROM DISTANT HURRICANE EDOUARD BEGIN TO IMPACT
THE AREA.
WED-WED NIGHT...A WEAK FRONTAL TROF OVER THE DEEP SOUTH WILL DRIFT
INTO N FL AND SUPPRESS THE ATLC RIDGE AXIS INTO THE FL STRAITS.
INTERACTION BTWN THESE TWO WX SYSTEMS WILL TIGHTEN THE LCL PGRAD
SUFFICIENTLY TO PRODUCE A GENTLE TO MODERATE W/SW BREEZE ACRS THE
LCL ATLC...ANY SEABREEZE WILL BE LIMITED TO THE IMMEDIATE TREASURE
COAST AND EVEN THEN ONLY FOR THE LATE AFTN/EARLY EVNG HRS. SEAS
3-4FT NEARSHORE AND 5-6FT OFFSHORE...LARGELY DUE TO CONTINUING
SWELLS FROM DISTANT HURRICANE EDOUARD.
THU-FRI...FRONTAL TROF WILL PUSH INTO S FL...ALLOWING A GENTLE TO
MODERATE W/NW BREEZE TO VEER TO THE N THRU THE DAY ON THU...THEN TO
THE N/NE ON FRI. SWELLS WILL GRADUALLY DAMPEN OUT THRU THE LATTER
HALF OF THE WEEK WITH SEAS SUBSIDING TO 3-4FT NEARSHORE AND 4-5FT
OFFSHORE ON THU...THEN 2-4FT AREAWIDE ON FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 89 74 89 74 / 30 30 50 40
MCO 92 74 92 73 / 40 30 50 40
MLB 88 73 88 75 / 30 30 40 30
VRB 88 72 89 74 / 30 20 40 30
LEE 92 75 91 74 / 40 30 50 40
SFB 92 75 92 74 / 40 30 50 40
ORL 92 76 92 74 / 40 30 50 40
FPR 88 72 88 73 / 30 20 40 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...WEITLICH
LONG TERM....BRAGAW
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
355 AM EDT MON SEP 15 2014
.DISCUSSION...
TODAY-TONIGHT...
WEAK ATLANTIC RIDGE WILL EXTEND ACROSS CENTRAL FLORIDA AT THE
SURFACE...PRODUCING LIGHT LOW LEVEL WINDS ACROSS THE REGION. THIS
WILL ALLOW THE EAST COAST SEA BREEZE TO DEVELOP AND MOVE INLAND
THROUGH THE AFTERNOON WITH A MORE INLAND PUSH EXPECTED SOUTH OF THE
CAPE. MOISTURE LOOKS TO BE SLIGHTLY GREATER TOWARD EAST CENTRAL
FLORIDA...ESPECIALLY OVER NRN AREAS AS DRIER AIR ACCOMPANIES A
850-700MB RIDGE BUILDING W-NW OVER WEST CENTRAL FLORIDA.
THE 00Z MOS POPS DIFFER SIGNIFICANTLY BETWEEN GFS AND NAM GUIDANCE
WITH GFS VALUES MUCH LOWER ONLY SHOWING RAIN CHANCES AROUND 20
PERCENT MOST LOCATIONS. HOWEVER LATEST HRRR RUN SHOWING SIGNS OF AT
LEAST ISOLATED TO SCATTERED CONVECTIVE DEVELOPMENT BETWEEN THE SEA
BREEZE BOUNDARIES INTO THE AFTERNOON. HAVE THEREFORE LEANED TOWARD A
BLEND BETWEEN THE TWO MODELS WITH GREATEST RAIN CHANCES...UP TO 40
PERCENT...FROM THE ORLANDO AREA NORTHWARD WHERE HIGHER MOISTURE WILL
EXIST. HIGHS WILL CONTINUE TO RANGE FROM THE UPPER 80S ALONG THE
COAST INTO THE LOW 90S ACROSS THE INTERIOR.
LINGERING CONVECTION FROM LATE DAY SEA BREEZE COLLISIONS OVER THE
INTERIOR MAY BE ABLE TO PUSH BACK TOWARD THE COAST...ESPECIALLY
NORTH OF MELBOURNE INTO THE EVENING. THIS ACTIVITY IS EXPECTED TO
DIMINISH INTO TONIGHT WITH RAIN CHANCES ENDING BY MIDNIGHT. TEMPS
WILL FALL INTO THE LOW TO MID 70S WITH SKIES PARTLY CLOUDY TO MOSTLY
CLEAR.
TUE-WED...
A COUPLED H30-H20 JET STREAK OVER THE GREAT LAKES/MID WEST WILL
PRODUCE STRONG UPR LVL DIVERGENCE OVER THE MID AND DEEP SOUTH.
THIS...IN TURN WILL INDUCE A BROAD SFC LOW TO FORM ALONG A STALLED
FRNTL BNDRY OVER THE DEEP SOUTH THAT WILL SLOWLY CRANK THE FRNT INTO
CENTRAL FL. A RELATIVELY WET PD THRU MIDWEEK WILL RESULT AS MOISTURE
POOLING WITHIN THE FRONTAL TROF PROVIDES THE FUEL NECESSARY FOR
SCT/NMRS SHRAS AND TSRAS ACRS THE CWA.
RUC40 REGIONAL ANALYSIS SHOWS SPORADIC POCKETS OF MID LVL VORTICITY
OVER THE GOMEX. THERE IS A POCKET OF COOL H50 AIR EXTENDING FROM NRN
CUBA ACRS THE BAHAMA BANK...TEMPS -8C/-9C...THAT WILL ALLOW SOME
WEAK MID LVL COOLING AS THE FRONT NUDGES ITS WAY S. HOWEVER...
H70-H50 LAPSE RATES ASSOCD WITH THIS AIRMASS ARE MODERATE AT BEST
WITH THE STEEPEST READINGS ARND 6.5C/KM.
INCREASING WRLY FLOW WILL PREVAIL AS THE APPROACHING TROF INTERACTS
WITH THE RETREATING ATLC RIDGE...A FLOW REGIME THAT USUALLY FAVORS
THE E FL PENINSULA FOR DAILY CONVECTION. WEAKER PGRAD ON TUE AS LOW
PRES ORGANIZES WILL ALLOW THE EAST COAST SEABREEZE TO FORM...WHILE
WRLY H85-H50 STEERING FLOW AOB 10KTS WILL KEEP IT PINNED NEAR THE
COAST. SLOW STORM MOTION ON TUE COMBINED WITH WEAKER FORCING AND
LOWER MOISTURE WILL KEEP COVERAGE AOB 50PCT...INCREASING TO 50/60PCT
WED AS THE FRONT DRIFTS THRU CENTRAL FL.
MAX TEMPS NEAR AVG (U80S/L90S) AS THE USUALLY WARMER WRLY FLOW IS
COUNTERED BY INCREASING CLOUD/PRECIP COVERAGE. MIN TEMPS ABV AVG
(L/M70S) AS INCREASING WRLY FLOW KEEPS THE AIRMASS MIXED WHILE CLOUD
COVER PROVIDES A BLANKETING EFFECT.
THU-SUN...
UPDATE TO FOLLOW.
&&
.AVIATION...
EAST COAST SEA BREEZE WILL DEVELOP AND MOVE INLAND THROUGH THE
AFTERNOON WITH A GREATER INLAND MOVEMENT EXPECTED SOUTH OF THE CAPE.
ISOLATED TO SCATTERED SHRA/TSRA WILL DEVELOP ALONG AND AHEAD OF THIS
BOUNDARY WITH BEST CHANCE FOR SHOWER/STORM DEVELOPMENT FROM ORLANDO
NORTHWARD TOWARD MID TO LATE AFTERNOON AS SEA BREEZE BOUNDARIES
COLLIDE ACROSS THE INTERIOR. LINGERING CONVECTION INTO THE EVENING
WILL DIMINISH BY MIDNIGHT.
&&
.MARINE...
TODAY/TONIGHT...WEAK RIDGE ACROSS THE AREA WILL PRODUCE LIGHTER
WINDS ACROSS THE COASTAL WATERS WITH VARIABLE DIRECTIONS...
ESPECIALLY THROUGH THE MORNING. WINDS NEAR THE COAST WILL INCREASE
UP TO 10 KNOTS OUT OF THE E/SE AS THE SEA BREEZE DEVELOPS AND MOVES
INLAND INTO THE AFTERNOON AND THEN DECREASE INTO THE EVENING OUT OF
THE S/SE SOUTH OF THE CAPE AND S/SW NORTH.
SWAN GUIDANCE CONTINUES TO BE EXTREMELY TOO HIGH WITH WAVE HEIGHTS
AND HAVE THEREFORE WENT WITH THE MORE REASONABLE WNAWAVE VALUES WITH
SEAS RANGING FROM 1-2 FEET.
TUE-TUE NIGHT...WEAK SFC/LOW LVL PGRAD WILL REMAIN IN PLACE WITH THE
ATLC RIDGE AXIS DRAPED OVER THE CENTRAL AND SOUTH FL PENINSULA.
LIGHT TO GENTLE WRLY BREEZE BCMG ONSHORE BY EARLY AFTN AS THE EAST
COAST SEA BREEZE DVLPS AND PUSHES INLAND...BCMG S/SW AFT SUNSET.
SEAS 2FT NEARSHORE THRU THE DAY...BCMG 2-3FT NEARSHORE AND 3-4FT
OFFSHORE AS SWELLS FROM DISTANT HURRICANE EDOUARD BEGIN TO IMPACT
THE AREA.
WED-WED NIGHT...A WEAK FRONTAL TROF OVER THE DEEP SOUTH WILL DRIFT
INTO N FL AND SUPPRESS THE ATLC RIDGE AXIS INTO THE FL STRAITS.
INTERACTION BTWN THESE TWO WX SYSTEMS WILL TIGHTEN THE LCL PGRAD
SUFFICIENTLY TO PRODUCE A GENTLE TO MODERATE W/SW BREEZE ACRS THE
LCL ATLC...ANY SEABREEZE WILL BE LIMITED TO THE IMMEDIATE TREASURE
COAST AND EVEN THEN ONLY FOR THE LATE AFTN/EARLY EVNG HRS. SEAS
3-4FT NEARSHORE AND 5-6FT OFFSHORE...LARGELY DUE TO CONTINUING
SWELLS FROM DISTANT HURRICANE EDOUARD.
THU-FRI...FRONTAL TROF WILL PUSH INTO S FL...ALLOWING A GENTLE TO
MODERATE W/NW BREEZE TO VEER TO THE N THRU THE DAY ON THU...THEN TO
THE N/NE ON FRI. SWELLS WILL GRADUALLY DAMPEN OUT THRU THE LATTER
HALF OF THE WEEK WITH SEAS SUBSIDING TO 3-4FT NEARSHORE AND 4-5FT
OFFSHORE ON THU...THEN 2-4FT AREAWIDE ON FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 89 74 89 74 / 30 30 50 40
MCO 92 74 92 73 / 40 30 50 40
MLB 88 73 88 75 / 30 30 40 30
VRB 88 72 89 74 / 30 20 40 30
LEE 92 75 91 74 / 40 30 50 40
SFB 92 75 92 74 / 40 30 50 40
ORL 92 76 92 74 / 40 30 50 40
FPR 88 72 88 73 / 30 20 40 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...WEITLICH
LONG TERM....BRAGAW
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
409 AM EDT MON SEP 15 2014
...LOCALLY HEAVY RAINFALL AND FLASH FLOODING POSSIBLE THIS
AFTERNOON AND EVENING...
.SYNOPSIS...
A STATIONARY FRONT WILL DISSIPATE OVER THE AREA TODAY. A STRONGER
COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND PUSH
THROUGH THE REGION WEDNESDAY. A STRONG INLAND WEDGE OF HIGH
PRESSURE WILL THEN PREVAIL IN WAKE OF THE FRONT INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
THROUGH SUNRISE...15/07Z RAP INSTABILITY ANALYSIS SHOWED THE
STATIONARY FRONT EXTENDED FROM ROUGHLY MILLEN GEORGIA TO
ESTILL...HENDERSONVILLE TO FOLLY BEACH IN SOUTH CAROLINA. NORTH
OF THE FRONT...WIDESPREAD STRATUS AND EVEN SOME FOG HAS DEVELOPED
WITH DEWPOINTS IN THE UPPER 60S...WHILE SOUTH OF THE FRONT
CEILINGS ARE CONSIDERABLY HIGHER WITH DEWPOINTS RUNNING IN THE
LOWER-MID 70S. THE WEAKENING FRONT WILL MOVE LITTLE THROUGH
SUNRISE...POSSIBLY DRIFTING EVER SO SLIGHTLY TO THE SOUTH WITH
VERY WEAK PRESSURE RISES STILL NOTED OVER EASTERN NORTH CAROLINA.
SUBTLE COASTAL CONVERGENCE ALONG THE COAST COULD PRODUCE ISOLATED
TO PERHAPS SCATTERED SHOWERS/TSTMS OVER THE NEXT FEW HOURS...
MAINLY FROM TYBEE ISLAND NORTH WHERE SURFACE MOISTURE FLUX
CONVERGENCE IS INCREASING. THE FOG NORTH OF THE FRONT HAS NOT BEEN
SIGNIFICANT SO FAR...BUT THERE IS A POSSIBILITY THAT STRATUS BUILD
DOWN PROCESSES COULD PRODUCE AT LEAST SOME POCKETS OF LOCALLY
DENSE FOG. TRENDS WILL BE WATCHED CAREFULLY ACROSS THE NORTHERN
ZONES...BUT A DENSE FOG ADVISORY IS NOT ANTICIPATED ATTM.
TODAY...THE SYNOPTIC PATTERN CONTINUES TO FAVOR A HEAVY RAIN
SETUP FOR SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. THE
WEAK STATIONARY FRONT THAT IS CURRENTLY BISECTING THE FORECAST
AREA IS FORECAST TO GRADUALLY WASH OUT THIS AFTERNOON AS BROAD
PRESSURE FALLS AHEAD OF POWERFUL SHORTWAVE ENERGY DIGGING INTO THE
OHIO VALLEY OVERSPREAD THE REGION. THE UPPER JET CONFIGURATION
REMAINS IN A FAVORABLE ORIENTATION FOR UPPER SUPPORT WITH THE
RIGHT ENTRANCE REGION FORECAST OR PROVIDE ANOTHER CORRIDOR OF
ENHANCED UPPER DIVERGENCE ATOP THE DECAYING FRONT AND SEA BREEZE
CIRCULATION DURING PEAK HEATING. MOST OF THE HIGH RESOLUTION
MODELS ARE SHOWING A SIGNAL FOR A CORRIDOR OF TORRENTIAL RAINS TO
SETUP ALONG THE I-95 CORRIDOR BY EARLY-MID AFTERNOON...POSSIBLY
INITIATING ALONG THE GEORGIA COAST...THEN GRADUALLY SPREADING
INLAND AND TO THE NORTH WITH THE SEA BREEZE. RAINFALL AMOUNTS OF
2 INCHES WITH LOCALLY HIGHER AMOUNTS IN EXCESS OF 5 INCHES WILL BE
POSSIBLE WITH SMALL MEAN STORM MOTION VECTORS AND ANOMALOUSLY HIGH
TROPOSPHERIC MOISTURE IN PLACE. SEE THE HYDROLOGY SECTION BELOW ON
INFORMATION ADDRESSING THE POTENTIAL FOR FLASH FLOODING.
POPS WILL BE INCREASED TO 60-70 PERCENT FOR MOST AREAS TODAY...
MAINLY DURING THE AFTERNOON HOURS. MUCH OF THE MORNING MAY
ACTUALLY BE FAIRLY QUIET...BUT AS THE FRONT BEGINS TO WASHES OUT
AND INSTABILITY INCREASES...EXPECT CONVECTIVE INITIATION TO OCCUR
BY EARLY AFTERNOON. SEVERAL GUIDANCE MEMBERS SUGGEST CATEGORICAL
POPS MAY EVENTUALLY BE NEEDED...WHICH WILL NEED TO BE CONSIDERED
LATER TODAY ONCE MESOSCALE CONVECTIVE TRENDS BECOME MORE APPARENT.
HIGHS WILL RANGE FROM THE MID 80S NORTH TO THE UPPER 80S ROUGHLY
SOUTH OF I-16.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
TONIGHT...CONVECTION WILL GRADUALLY WIND DOWN DURING THE EVENING
HOURS AS INSTABILITY WANES AND UPPER SUPPORT LESSENS. THERE WILL
LIKELY BE A LARGE AREA OF MODERATE TO HEAVY RAIN OVER PARTS OF THE
FORECAST AREA JUST AFTER SUNSET...ESPECIALLY ACROSS INTERIOR
SOUTHEAST GEORGIA WERE UPWARDS OF 3-5 INCHES OF RAIN FELL
YESTERDAY. THERE WILL BE A CONTINUED RISK FOR FLASH FLOODING AND
THE FLASH FLOOD WATCH WILL REMAIN IN FORCE THROUGH 11 PM EDT.
LIKELY POPS WILL GIVE WAY TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT. LOWS WILL RANGE FROM THE LOWER 70S WELL INLAND TO THE
MID-UPPER 70S AT THE COAST.
TUESDAY...EXPECT THE PATTERN TO BE STEADILY TRANSITIONING...AS THE
UPPER RIDGE ACROSS THE SOUTHERN STATES BECOMES SUPPRESSED BY AN
AMPLIFYING TROUGH ALONG THE EAST COAST. AT THE SURFACE...A COLD
FRONT WILL DESCEND THROUGH THE APPALACHIAN REGION...WHILE A
DOWNSTREAM SURFACE TROUGH SETS UP ACROSS THE SOUTHEAST COASTLINE.
THE RIBBON OF DEEP MOISTURE THAT HAS BROUGHT SEVERAL DAYS OF HEAVY
RAIN WILL GRADUALLY SLIP SOUTHEAST AS THE DAY PROGRESSES...YET
LINGER ACROSS THE FORECAST AREA LONG ENOUGH TO SUPPORT SCATTERED TO
NUMEROUS THUNDERSTORMS FROM LATE MORNING THROUGH THE EVENING HOURS.
SHORTWAVE ENERGY MOVING ALONG THE BASE OF THE EXPANDING UPPER
TROUGH...AS WELL AS THE APPROACH OF AN UPPER JET...SUGGESTS STRONGER
SYNOPTIC SCALE SUPPORT FOR CONVECTION. ISOLATED MARGINALLY SEVERE
THUNDERSTORMS ARE POSSIBLE WHERE BOUNDARY INTERACTIONS
OCCUR...HOWEVER ORGANIZED SEVERE WEATHER IS NOT ANTICIPATED AT THIS
TIME. THE SURFACE TROUGH WILL MOVE OFF THE COAST AFTER SUNSET AND BE
FOLLOWED BY THE COLD FRONT BY DAYBREAK WEDNESDAY. BEST CONVECTIVE
COVERAGE WILL THUS SHIFT INTO THE MARINE ZONES OVERNIGHT.
DESPITE THICK CLOUD COVER AND DECENT RAIN COVERAGE DURING THE
DAYTIME HOURS...HIGH TEMPERATURES WILL RISE ABOVE SEASONAL
NORMALS DUE TO COMPRESSIONAL HEATING AHEAD OF THE FRONT AND A
DOWNSLOPE FLOW COMPONENT. EXPECT WARM TEMPERATURES IN THE UPPER
80S AWAY FROM THE LOCALLY COOLER COASTLINE. NIGHTTIME LOWS WILL
FALL CLOSER TO SEASONAL NORMALS IN THE UPPER 60S TO LOW 70S.
WEDNESDAY AND THURSDAY...THE COLD FRONT WILL STEADILY DROP SOUTH
AND EAST OF THE FORECAST AREA WEDNESDAY...BEFORE STALLING IN THE
OFFSHORE WATERS THURSDAY. A SERIES OF SHORTWAVES PROGRESSING
ACROSS THE BASE OF THE BROAD UPPER TROUGH WILL ALLOW WAVES OF
LOW PRESSURE TO DEVELOP ALONG THE STALLED FRONT...AS HIGH PRESSURE
BUILDS FROM THE NORTH IN ITS WAKE. SCATTERED THUNDERSTORMS ARE
STILL POSSIBLE WEDNESDAY AND THURSDAY AFTERNOONS. HOWEVER OVERALL
CONVECTIVE COVERAGE WILL BE NOTABLY LESS THAN EARLIER IN THE
WEEK...AS DEEP MOISTURE IS CONFINED FAR OFFSHORE WITH THE
LINGERING FRONT. HIGH TEMPERATURES COULD STILL REACH THE MID TO
UPPER 80S ON WEDNESDAY...WITH THE MORE DRAMATIC COOLING TREND
BEGINNING WEDNESDAY NIGHT INTO THURSDAY. LOW TEMPERATURES
WEDNESDAY NIGHT WILL BE COOLER IN THE MID TO UPPER 60S
INLAND...THEN HIGH TEMPERATURES THURSDAY AFTERNOON WILL BE
SUPPRESSED IN THE LOW 80S WITHIN STRENGTHENING NORTHEAST FLOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A WEDGE OF SURFACE HIGH PRESSURE WILL BECOME ESTABLISHED INLAND
LATE WEEK INTO THE WEEKEND. THE UPPER LEVEL PATTERN GRADUALLY
WEAKENS DURING THIS TIME FRAME...AS THE TROUGH ALONG THE EAST
COAST DIMINISHES. THE BEST RAIN CHANCES WILL BECOME INCREASINGLY
CONFINED TO THE IMMEDIATE COASTLINE AND MARINE ZONES...AS DEEPER
MOISTURE AND FORCING REMAIN OFFSHORE ALONG THE PERIPHERY OF THE
INLAND WEDGE. SOLID NORTHEAST FLOW WILL SUPPORT NOTABLY COOLER
CONDITIONS THROUGH THE PERIOD. HIGH TEMPERATURES WILL ONLY REACH
THE LOW 80S FRIDAY AND SATURDAY...WHILE LOW TEMPERATURES FALL INTO
THE LOW TO MID 60S. AS THE WEDGE OF HIGH PRESSURE WEAKENS SUNDAY
AND MONDAY...EXPECT TEMPERATURES TO RETURN TOWARD SEASONAL NORMALS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
KCHS...THE TERMINAL REMAINS SOUTH OF THE STATIONARY FRONT. IFR
CIGS ARE BECOMING MORE WIDESPREAD AND WILL LINGER THROUGH SUNRISE.
THERE IS ABOUT A 40 PERCENT CHANCE THAT LIFR CIGS WILL
DEVELOP...BUT MODEL TRENDS ARE NOT SHOWING A DEFINITIVE TREND AT
THIS POINT. WILL SHOW PREVAILING LOW-END IFR THROUGH 12-13Z WITH
CONDITIONS IMPROVING TO MVFR THEREAFTER WITH VFR CIGS BY 18Z.
SHOWERS/TSTMS ARE LIKELY AGAIN TODAY...BUT ITS UNCLEAR WHEN TSTMS
IMPACTS WILL OCCUR. BEST CHANCES ATTM APPEAR TO BE IN THE 19-22Z
TIME FRAME...BUT THIS WILL NEED TO BE REFINED AS THE DAY
PROGRESSES.
KSAV...THE STATIONARY FRONT REMAINS IN THE VCNTY OF THE TERMINAL.
IFR CIGS ARE NOT TOO FAR AND EXPECT VFR CIGS TO LOWER TO IFR
THRESHOLDS BY 09Z. SOME LIGHT FOG MAY ALSO OCCUR...BUT THE BETTER
CHANCES FOR FOG IMPACTS LOOK TO REMAIN TO THE NORTH AND WEST OF
THE TERMINAL. IFR CIGS WILL LINGER THROUGH SUNRISE WITH CIGS
LIVING TO MVFR BY 13Z AND VFR BY 16Z. BEST CHANCES FOR TSTM
IMPACTS TODAY WILL BE 17-20Z TIME FRAME...BUT THIS WILL NEED TO BE
REFINED AS THE DAY PROGRESSES.
EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS POSSIBLE
IN OCCASIONAL SHRA AND/OR TSRA DURING THE AFTERNOON AND EARLY
NIGHT TIME PERIODS...AND IN LATE NIGHT/MORNING LOW STRATUS AND/OR
FOG.
&&
.MARINE...
TODAY....THERE WILL BE A RISK FOR WATERSPOUTS THIS MORNING WITH
NUMEROUS LOW-LEVEL BOUNDARIES OBSERVED ON KCLX RADAR DATA. HAVE
ALREADY SEEN TWO STORMS FORM OFF BEAUFORT COUNTY WITH TORNADIC
WATERSPOUT SIGNATURES AND WITH LIGHT WIND FIELDS IN PLACE THROUGH
THE LOWEST PORTIONS OF THE TROPOSPHERE...THE ATMOSPHERIC SETUP
LOOKS FAVORABLE FOR MORE WATERSPOUTS THROUGH LATE MORNING.
OTHERWISE...LIGHT WINDS WILL REMAIN PLACE ACROSS THE WATERS TODAY
AS A WEAK STATIONARY FRONT GRADUALLY DISSIPATES AND LIFTS NORTH.
WINDS WILL GENERALLY REMAIN 10 KT OR LESS WITH SEAS 1 TO 2 FT.
LOCALLY HEAVY RAINFALL WILL OCCASIONALLY REDUCE VSBYS TO LESS THAN
1 NM AT TIMES.
TONIGHT...WINDS WILL RETURN TO A MORE UNIFORM SOUTHERLY REGIME AS
ATLANTIC HIGH PRESSURE BRIEFLY REBUILDS INTO THE AREA. WINDS WILL
REMAIN LESS THAN 10 KT WITH SEAS 1-2 FT...EXCEPT 2-3 FT OVER THE
GEORGIA OFFSHORE LEG.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL APPROACH TUESDAY AND
MOVE THROUGH THE MARINE ZONES WEDNESDAY. LIGHT WINDS WILL
GENERALLY PREVAIL BOTH DAYS...WHILE WIND DIRECTIONS BECOME
NORTH/NORTHEAST BEHIND THE FRONT. THE POTENTIAL FOR WATERSPOUTS
WILL REMAIN HIGH THROUGH TUESDAY MORNING DUE TO THE LIGHT WIND
REGIME AND DEEP MOISTURE. HIGH PRESSURE WILL THEN STEADILY BUILD
INTO INLAND AREAS BY THURSDAY...WITH THE GRADIENT TIGHTENING
ACCORDINGLY AND SUPPORTING A SURGE IN NORTHEAST FLOW INTO FRIDAY.
SMALL CRAFT ADVISORY WINDS AND SEAS WILL BE POSSIBLE FOR PORTIONS
OF THE COASTAL WATERS LATE IN THE WEEK...ESPECIALLY CONSIDERING
LINGERING SWELLS FROM DISTANT TROPICAL CYCLONE EDOUARD.
RIP CURRENTS...LONG PERIOD SWELL FROM TROPICAL CYCLONE EDOUARD
WILL ARRIVE AT THE BEACHES LATER WEDNESDAY INTO THURSDAY...BEFORE
STRONGER ONSHORE WINDS IMPACT THE COASTAL SECTIONS FRIDAY THROUGH
SUNDAY. THESE CONDITIONS WILL LIKELY LEAD TO AN ENHANCED RISK OF
RIP CURRENTS DURING THE SECOND HALF OF THE WEEK.
&&
.HYDROLOGY...
A FLASH FLOOD WATCH IS IN EFFECT FOR ALL OF SOUTHEAST SOUTH
CAROLINA AND MUCH OF SOUTHEAST GEORGIA THROUGH LATE EVENING. HIGH
PWATS NEAR THE 99TH PERCENTILE FOR MID-SEPTEMBER COMBINED WITH
FAVORABLE UPPER DYNAMICS AND SLOW STORM MOTION VECTORS INDICATE
THERE WILL BE A ROUND OF SLOW MOVING SHOWERS/TSTMS AFFECTING THE
AREA TODAY. ANY TSTMS THAT DEVELOP WILL BE EFFICIENT RAIN
PRODUCERS WHICH WILL BE CAPABLE OF PRODUCING HOURLY RAINFALL RATES
IN EXCESS OF 2-3 IN/HR. THE LATEST 1-HR FLASH FLOOD GUIDANCE
VALUES ARE VERY NEAR THESE RATES...SO BELIEVE THERE IS A ENOUGH OF
A RISK FOR FLASH FLOODING OVER A LARGE ENOUGH AREA TO JUSTIFY A
FLASH FLOOD WATCH THROUGH LATE EVENING. IN ADDITION...SOME AREAS
SAW RAIN AMOUNTS IN EXCESS OF 4-5 INCHES WITH A LARGE AREA OF 2-3
INCHES...ESPECIALLY ACROSS INTERIOR SOUTHEAST GEORGIA. WITH THE
GROUND SATURATED IN THESE AREAS...IT WILL NOT TAKE LONG FOR FLASH
FLOODING TO OCCUR. RAINFALL AMOUNTS WILL AVERAGE 1-2 INCHES
THROUGH TONIGHT WITH ISOLATED AMOUNTS RUNNING IN EXCESS OF 5-6
INCHES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
047>052.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
304 AM CDT MON SEP 15 2014
.DISCUSSION...
240 PM CDT
MAIN FOCUS IS ON OUR NEXT RAIN CHANCE WHICH COMES VERY LATE TONIGHT
THROUGH MUCH OF MONDAY...AND A CONTINUATION OF COOL/BELOW AVERAGE
TEMPS FOR MID-SEPTEMBER.
IN THE NEAR TERM...A PLEASANT BUT STILL COOL WEATHER WAS IN PLACE
ACROSS THE REGION THIS AFTERNOON. SURFACE HIGH PRESSURE WAS CENTERED
OVER THE EASTERN GREAT LAKES...WITH RIDGING EXTENDING SOUTHWEST
ACROSS INDIANA AND ILLINOIS. THE RESULT IS MOSTLY SUNNY AND SLIGHTLY
MILDER CONDITIONS WITH TEMPS REACHING THE MID 60S IN MOST SPOTS AND
UPPER 60S IN A COUPLE IN THE WEST/SOUTH PARTS OF THE CWA. LIGHT
WINDS AND CLEAR SKIES THIS EVENING WILL ALLOW TEMPS TO FALL OFF
FAIRLY QUICKLY HOWEVER...WITH READINGS DROPPING THROUGH THE 50S THIS
EVENING AND INTO THE MID-UPPER 40S LATER TONIGHT BEFORE CLOUDS BEGIN
TO INCREASE AFTER MIDNIGHT.
THIS INCREASE IN CLOUD COVER LATE TONIGHT WILL BE IN ASSOCIATION
WITH A MID-LEVEL SHORT WAVE TROUGH CURRENTLY DIGGING SOUTHEAST FROM
SASKATCHEWAN INTO MONTANA PER AFTERNOON GOES VAPOR IMAGERY.
INCREASING SOUTHERLY LOW LEVEL FLOW WILL DEVELOP AS THIS WAVE DIGS
SOUTHEAST...WITH 925-850 MB LAYER MOISTURE TRANSPORT INCREASING ON
THE NOSE OF A 30-35 KT LOW LEVEL JET WHICH DEVELOPS FROM THE TX/OK
PANHANDLE REGION. THIS AXIS OF MOISTURE TRANSPORT EVENTUALLY WORKS
INTO NORTHERN MISSOURI AND WEST CENTRAL IL MONDAY MORNING AS THE JET
VEERS MORE WEST-SOUTHWESTERLY. WHILE A FEW SHOWERS MAY DEVELOP
ACROSS FAR NORTH CENTRAL IL PRIOR TO SUNRISE...IT APPEARS THAT THE
BEST FORCING WILL ARRIVE SHORTLY AFTER...AS MID-LEVEL VORT
APPROACHES. A COMBINATION OF 40-50 METER HEIGHT FALLS...UPPER
DIVERGENCE BENEATH THE RIGHT REAR ENTRANCE REGION OF A 100+ KT UPPER
JET STREAK OVER THE GREAT LAKES...AND DEVELOPING FRONTOGENETIC
FORCING WITHIN THE LOW-MID LEVELS SHOULD PROVIDE SUFFICIENT FORCING
FOR PRODUCING RAIN/SHOWERS ACROSS THE AREA DURING THE DAY MONDAY.
WITH VARIOUS MODEL QPF AMOUNTS IN THE 0.25 TO 0.35 RANGE...RAIN IS
EXPECTED TO TAPER OFF FROM THE WEST/NORTHWEST LATE MONDAY AFTERNOON
AND EARLY MONDAY EVENING AS THE RELATIVELY PROGRESSIVE DISTURBANCE
MOVES EAST OF THE FORECAST AREA. STRONG HEIGHT RISES THEN ACCOMPANY
DEVELOPMENT OF SURFACE HIGH PRESSURE ACROSS THE MID-MISSISSIPPI
VALLEY MONDAY NIGHT AND TUESDAY.
SURFACE HIGH PRESSURE IS EXPECTED TO LINGER ACROSS THE ACROSS THE
MIDWEST FOR MUCH OF THE REMAINDER OF THE WEEK...SETTING THE STAGE
FOR DRY WEATHER WITH COOL NIGHTS AND COOLER THAN AVERAGE BUT SLOWLY
MODERATING TEMPS THROUGH NEXT WEEKEND. AFTER CLOUD/PRECIP INFLUENCED
TEMPS ONLY IN THE UPPER 50S/LOWER 60S OVER MUCH OF THE AREA
MONDAY...DAYTIME HIGHS SHOULD MODERATE THROUGH THE 60S THROUGH
WEDNESDAY AND THEN FINALLY INTO THE 70S FOR THE END OF THE
WEEK/WEEKEND. COLDEST OVERNIGHT MINS LOOK TO BE LATE MONDAY NIGHT AS
HIGH PRESSURE BUILDS IN WITH LOW 40/A FEW UPPER 30S...WITH LOWS
GRADUALLY MODERATING INTO THE 50S BY THE END OF THE WEEK.
UPPER PATTERN EVOLVES INTO A LONG WAVE TROUGH OVER THE EAST COAST
WITH AN UPPER RIDGE ACROSS THE ROCKIES BY FRIDAY. SLIGHT EASTWARD
PROGRESSION AND FLATTENING OF THE PATTERN ALLOWS RETURN OF
WARMER/HIGHER MOISTURE CONTENT AIR INTO THE REGION INTO THE WEEKEND.
THIS YIELDS AN INCREASING CHANCE OF SHOWERS/THUNDERSTORMS AS A
MID-LEVEL DISTURBANCE PROPAGATES THROUGH THE FLOW AND A SURFACE
TROUGH APPROACHES AND MOVES ACROSS THE AREA FRIDAY NIGHT THROUGH
SUNDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* COLD FRONT MIDDAY MONDAY BRINGING A WIND SHIFT TO THE NW OR NNE
ALONG WITH MVFR POSSIBLY BRIEFLY IFR CONDITIONS AND RAIN.
BMD
//DISCUSSION...UPDATED 06Z...
OVERNIGHT THROUGH AROUND MID MORNING MONDAY EXPECT STEADY STATE
CONDITIONS WITH VERY LIGHT SSW FLOW AND VFR CONDITIONS. AN UPPER
LEVEL WAVE WILL MOVE ACROSS THE REGION MONDAY BRINGING SHOWERS TO
THE AREA BY LATE MORNING OR EARLY AFTERNOON. CIGS ARE EXPECTED TO
LOWER TO AT LEAST MVFR AND SOME MODELS SUGGEST THE POSSIBILITY OF A
COUPLE HOURS OF IFR CIGS AS THE SURFACE TROUGH DROPS ACROSS THE
AREA. CIGS ARE EXPECTED TO QUICKLY SCATTER OUT THOUGH EARLY TO MID
EVENING BEHIND THE FRONT. WINDS WILL BE TRICKY DURING THE DAY
MONDAY. WINDS ARE EXPECTED TO SHIFT TO SOME SORT OF NORTHERLY
COMPONENT BUT NOT QUITE SURE AT THIS POINT IF IT WILL BE NW OR NNE
AT THE CHICAGO TERMINALS WHERE SOME GUIDANCE SHOWS THE FRONT SURGING
AHEAD AND TURNING WINDS NNE OFF OF LAKE MICHIGAN. GIVEN THE RELATIVE
WARMTH OF THE LAKE RELATIVE TO THE AIRMASS...WILL LEAN AWAY FROM
THIS SOLUTION IN THE MEANTIME...BUT IF WINDS DO END UP TURNING MORE
NNE IT WOULD LIKELY BE DURING THE AFTERNOON...THEN WINDS SHOULD
EVENTUALLY SETTLE BACK TOWARDS THE NW LATER IN THE EVENING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW CONFIDENCE IN WIND DIRECTION POST FRONTAL MONDAY AFTERNOON.
GUIDANCE RANGES FROM NW TO NNE.
* MEDIUM CONFIDENCE IN MVFR CONDITIONS AND RAIN...LOW CONFIDENCE
IN IFR.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...VFR. NORTHWEST WINDS BECOMING WEST.
WEDNESDAY...VFR. WEST WINDS BECOMING NORTHEAST.
THURSDAY...VFR. EAST WINDS.
FRIDAY...VFR. SOUTHEAST WINDS.
SATURDAY...VFR. BREEZY SOUTH-SOUTHWEST WINDS. CHANCE OF
THUNDERSTORMS.
MDB
&&
.MARINE...
303 AM CDT
LOW PRESSURE NEAR JAMES BAY THIS MORNING WILL DRAG A COLD FRONT
ACROSS LAKE MICHIGAN. WINDS WILL TURN NORTHWEST TO NORTH BEHIND THE
FRONT...AND MAY BRIEFLY INCREASE INTO THE 20 TO 25 KT RANGE
ESPECIALLY ON THE SOUTH END OF THE LAKE THIS EVENING. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT ALLOWING WINDS TO REMAIN MODEST FOR A
PERIOD BEFORE SOUTHWEST FLOW BEGINS TO FRESHEN UP AGAIN OVER THE
NORTH HALF OF LAKE MICHIGAN MIDDAY TUESDAY. ANOTHER COLD FRONT WILL
DIVE SOUTH ACROSS LAKE MICHIGAN ON WEDNESDAY TURNING WINDS NORTH TO
NORTHEAST AND INCREASING FOR A SHORT PERIOD TO AROUND 30 KT ONCE
AGAIN.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
302 AM CDT Mon Sep 15 2014
.SHORT TERM...(Today)
ISSUED AT 301 AM CDT MON SEP 15 2014
Main concern for today is shower/storm timing/chances associated
with the passage of a weak cold front and driving upper level
energy. The upper level forcing is somewhat complicated as it will
be provided by two separate disturbances. The first/weaker wave is
tracking east across the central Plains, while the second/stronger
wave is diving across the northern Plains. The second wave should
end up being the dominant feature for us, although both waves should
tend to shear out to some degree as they push into the confluent
flow across the Midwest.
The best forcing/frontal arrival have slowed some from previous
forecast, with the front not expected to clear the entire forecast
area until this evening. This slower arrival will also delay the
better chances for precipitation until the midday/afternoon hours.
Have expanded thunder mention to the entire forecast area today
given the steep mid-level lapse rates on forecast soundings
area wide. This north/east shift of thunder chances is also supported
by storms currently tracking east across southern Iowa. These storms
were located on the nose of a 25kt low-level jet in advance of the
central Plains wave. The forcing of the LLJ and central Plains wave
should weaken before reaching the local area, however it is expected
to be replaced by upper-level divergence/mid-level frontogenesis as
a jet streak ahead of the northern Plains wave arrives. A fairly
wide N-S temperature range is likely across the forecast area today
considering the fairly early arrival of the front/precipitation in
our northwest counties, compared to the evening frontal arrival
across southeast Illinois.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 301 AM CDT MON SEP 15 2014
Cold front should reach the I-70 corridor by sunset and be out of
the forecast area shortly afterward, taking the rain with it. Fairly
sharp clearing expected behind the front as high pressure builds in,
but clouds will linger much of the night in southeast Illinois.
Quiet midweek period expected as the high drifts across the Midwest.
Evening models have various interpretations of some convective
activity to our southwest on Wednesday, along the periphery of some
upper ridging across the Rockies. but all models keep it in Missouri
and will thus keep our forecast dry. Slow moderating trend in
temperatures with lower 70s widespread by Thursday.
Upper ridge breaks down late in the week before rebuilding along the
West Coast late in the weekend. Longer range models dig a sharpening
upper wave across the mid and upper Mississippi Valley by Saturday
night, with rain chances mainly focused in the Saturday afternoon
and evening time frame. Beyond that, the models show quite a bit of
divergence in the evolution of this wave. The latest ECMWF model
forms a closed low over Lake Superior Saturday night and drives a
large slug of cooler air across the Midwest later in the weekend,
while the steadier GFS is much more progressive and shows much less
of a temperature change. That sharper scenario is more of a recent
development and thus for now have only shown some small decrease in
temperatures for Sunday and Monday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1152 PM CDT SUN SEP 14 2014
Southerly winds have developed across the central Illinois
terminals this evening. Lift ahead of fast moving short-wave over
the plains is producing some virga echoes to the northwest of the
TAF sites late this evening. Moisture will continue to develop
ahead of the wave through the remainder of the night with the
column gradually becoming saturated. there will be an increasing
chance of precip reaching the surface at KPIA and possibly KBMI
and KSPI by 12z. 15/00z NAM has slowed the progress of the system
and latest HRRR also shows a delay in the system suggesting that
the passage of the cold front associated with the wave will be a
bit slower than the previous TAF package.
Elevated instability may be sufficient for some thunder during the
day ahead of the front. Will keep current mention of VCTS in KSPI
and KDEC but push timing back into the afternoon just ahead of
frontal passage.
Winds should shift to the North during the late afternoon and
early evening behind the front. Although the boundary layer
remains saturated through the night, winds appear to be significant
enough to keep vsbys at least MVFR. Will keep MVFR CIGS in place as
well as stratus appears to be more likely.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAK
LONG TERM...GEELHART
AVIATION...BARKER/BAK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1224 AM CDT MON SEP 15 2014
.DISCUSSION...
240 PM CDT
MAIN FOCUS IS ON OUR NEXT RAIN CHANCE WHICH COMES VERY LATE TONIGHT
THROUGH MUCH OF MONDAY...AND A CONTINUATION OF COOL/BELOW AVERAGE
TEMPS FOR MID-SEPTEMBER.
IN THE NEAR TERM...A PLEASANT BUT STILL COOL WEATHER WAS IN PLACE
ACROSS THE REGION THIS AFTERNOON. SURFACE HIGH PRESSURE WAS CENTERED
OVER THE EASTERN GREAT LAKES...WITH RIDGING EXTENDING SOUTHWEST
ACROSS INDIANA AND ILLINOIS. THE RESULT IS MOSTLY SUNNY AND SLIGHTLY
MILDER CONDITIONS WITH TEMPS REACHING THE MID 60S IN MOST SPOTS AND
UPPER 60S IN A COUPLE IN THE WEST/SOUTH PARTS OF THE CWA. LIGHT
WINDS AND CLEAR SKIES THIS EVENING WILL ALLOW TEMPS TO FALL OFF
FAIRLY QUICKLY HOWEVER...WITH READINGS DROPPING THROUGH THE 50S THIS
EVENING AND INTO THE MID-UPPER 40S LATER TONIGHT BEFORE CLOUDS BEGIN
TO INCREASE AFTER MIDNIGHT.
THIS INCREASE IN CLOUD COVER LATE TONIGHT WILL BE IN ASSOCIATION
WITH A MID-LEVEL SHORT WAVE TROUGH CURRENTLY DIGGING SOUTHEAST FROM
SASKATCHEWAN INTO MONTANA PER AFTERNOON GOES VAPOR IMAGERY.
INCREASING SOUTHERLY LOW LEVEL FLOW WILL DEVELOP AS THIS WAVE DIGS
SOUTHEAST...WITH 925-850 MB LAYER MOISTURE TRANSPORT INCREASING ON
THE NOSE OF A 30-35 KT LOW LEVEL JET WHICH DEVELOPS FROM THE TX/OK
PANHANDLE REGION. THIS AXIS OF MOISTURE TRANSPORT EVENTUALLY WORKS
INTO NORTHERN MISSOURI AND WEST CENTRAL IL MONDAY MORNING AS THE JET
VEERS MORE WEST-SOUTHWESTERLY. WHILE A FEW SHOWERS MAY DEVELOP
ACROSS FAR NORTH CENTRAL IL PRIOR TO SUNRISE...IT APPEARS THAT THE
BEST FORCING WILL ARRIVE SHORTLY AFTER...AS MID-LEVEL VORT
APPROACHES. A COMBINATION OF 40-50 METER HEIGHT FALLS...UPPER
DIVERGENCE BENEATH THE RIGHT REAR ENTRANCE REGION OF A 100+ KT UPPER
JET STREAK OVER THE GREAT LAKES...AND DEVELOPING FRONTOGENETIC
FORCING WITHIN THE LOW-MID LEVELS SHOULD PROVIDE SUFFICIENT FORCING
FOR PRODUCING RAIN/SHOWERS ACROSS THE AREA DURING THE DAY MONDAY.
WITH VARIOUS MODEL QPF AMOUNTS IN THE 0.25 TO 0.35 RANGE...RAIN IS
EXPECTED TO TAPER OFF FROM THE WEST/NORTHWEST LATE MONDAY AFTERNOON
AND EARLY MONDAY EVENING AS THE RELATIVELY PROGRESSIVE DISTURBANCE
MOVES EAST OF THE FORECAST AREA. STRONG HEIGHT RISES THEN ACCOMPANY
DEVELOPMENT OF SURFACE HIGH PRESSURE ACROSS THE MID-MISSISSIPPI
VALLEY MONDAY NIGHT AND TUESDAY.
SURFACE HIGH PRESSURE IS EXPECTED TO LINGER ACROSS THE ACROSS THE
MIDWEST FOR MUCH OF THE REMAINDER OF THE WEEK...SETTING THE STAGE
FOR DRY WEATHER WITH COOL NIGHTS AND COOLER THAN AVERAGE BUT SLOWLY
MODERATING TEMPS THROUGH NEXT WEEKEND. AFTER CLOUD/PRECIP INFLUENCED
TEMPS ONLY IN THE UPPER 50S/LOWER 60S OVER MUCH OF THE AREA
MONDAY...DAYTIME HIGHS SHOULD MODERATE THROUGH THE 60S THROUGH
WEDNESDAY AND THEN FINALLY INTO THE 70S FOR THE END OF THE
WEEK/WEEKEND. COLDEST OVERNIGHT MINS LOOK TO BE LATE MONDAY NIGHT AS
HIGH PRESSURE BUILDS IN WITH LOW 40/A FEW UPPER 30S...WITH LOWS
GRADUALLY MODERATING INTO THE 50S BY THE END OF THE WEEK.
UPPER PATTERN EVOLVES INTO A LONG WAVE TROUGH OVER THE EAST COAST
WITH AN UPPER RIDGE ACROSS THE ROCKIES BY FRIDAY. SLIGHT EASTWARD
PROGRESSION AND FLATTENING OF THE PATTERN ALLOWS RETURN OF
WARMER/HIGHER MOISTURE CONTENT AIR INTO THE REGION INTO THE WEEKEND.
THIS YIELDS AN INCREASING CHANCE OF SHOWERS/THUNDERSTORMS AS A
MID-LEVEL DISTURBANCE PROPAGATES THROUGH THE FLOW AND A SURFACE
TROUGH APPROACHES AND MOVES ACROSS THE AREA FRIDAY NIGHT THROUGH
SUNDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* COLD FRONT MIDDAY MONDAY BRINGING A WIND SHIFT TO THE NW OR NNE
ALONG WITH MVFR POSSIBLY BRIEFLY IFR CONDITIONS AND RAIN.
BMD
//DISCUSSION...UPDATED 06Z...
OVERNIGHT THROUGH AROUND MID MORNING MONDAY EXPECT STEADY STATE
CONDITIONS WITH VERY LIGHT SSW FLOW AND VFR CONDITIONS. AN UPPER
LEVEL WAVE WILL MOVE ACROSS THE REGION MONDAY BRINGING SHOWERS TO
THE AREA BY LATE MORNING OR EARLY AFTERNOON. CIGS ARE EXPECTED TO
LOWER TO AT LEAST MVFR AND SOME MODELS SUGGEST THE POSSIBILITY OF A
COUPLE HOURS OF IFR CIGS AS THE SURFACE TROUGH DROPS ACROSS THE
AREA. CIGS ARE EXPECTED TO QUICKLY SCATTER OUT THOUGH EARLY TO MID
EVENING BEHIND THE FRONT. WINDS WILL BE TRICKY DURING THE DAY
MONDAY. WINDS ARE EXPECTED TO SHIFT TO SOME SORT OF NORTHERLY
COMPONENT BUT NOT QUITE SURE AT THIS POINT IF IT WILL BE NW OR NNE
AT THE CHICAGO TERMINALS WHERE SOME GUIDANCE SHOWS THE FRONT SURGING
AHEAD AND TURNING WINDS NNE OFF OF LAKE MICHIGAN. GIVEN THE RELATIVE
WARMTH OF THE LAKE RELATIVE TO THE AIRMASS...WILL LEAN AWAY FROM
THIS SOLUTION IN THE MEANTIME...BUT IF WINDS DO END UP TURNING MORE
NNE IT WOULD LIKELY BE DURING THE AFTERNOON...THEN WINDS SHOULD
EVENTUALLY SETTLE BACK TOWARDS THE NW LATER IN THE EVENING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW CONFIDENCE IN WIND DIRECTION POST FRONTAL MONDAY AFTERNOON.
GUIDANCE RANGES FROM NW TO NNE.
* MEDIUM CONFIDENCE IN MVFR CONDITIONS AND RAIN...LOW CONFIDENCE
IN IFR.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...VFR. NORTHWEST WINDS BECOMING WEST.
WEDNESDAY...VFR. WEST WINDS BECOMING NORTHEAST.
THURSDAY...VFR. EAST WINDS.
FRIDAY...VFR. SOUTHEAST WINDS.
SATURDAY...VFR. BREEZY SOUTH-SOUTHWEST WINDS. CHANCE OF
THUNDERSTORMS.
MDB
&&
.MARINE...
144 PM CDT
HIGH PRESSURE CENTERED OVER THE OHIO VALLEY WILL CONTINUE TO
SLOWLY LIFT NORTHEAST...BECOMING CENTERED OVER NEW ENGLAND MONDAY
MORNING. ALONG THE WESTERN END OF THIS HIGH PRESSURE CENTER IS A
TIGHTER GRADIENT...WHICH HAS BECOME EVIDENT ALONG THE NORTHERN
PORTIONS OF LAKE MICHIGAN WITH WINDS GUSTING AT TIMES TO 30KT FROM
THE SOUTHWEST. A FRONTAL BOUNDARY WILL SWEEP ACROSS LAKE MICHIGAN ON
MONDAY TURNING WINDS WEST/NORTHWEST. THEN ANOTHER RIDGE OF HIGH
PRESSURE WILL BRING ANOTHER PERIOD OF LIGHTER WINDS TO THE LAKE
MONDAY NGT THRU TUE.
HIGH PRESSURE WILL THEN REMAIN IN PLACE THROUGH EARLY
THURSDAY...THEN LIFT NORTHEAST WITH FLOW TURNING SOUTHERLY AND A
TIGHTENING GRADIENT THURSDAY NGT THROUGH FRIDAY. AT THIS TIME IT
IS POSSIBLE WIND COULD GUST TO 30KT FRIDAY NIGHT INTO
SATURDAY...MAINLY FOR THE NORTHERN HALF OF THE LAKE.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1152 PM CDT Sun Sep 14 2014
.UPDATE...
ISSUED AT 823 PM CDT SUN SEP 14 2014
Cyclogenesis occurring over central High Plains this evening in
response to a fast moving short wave moving out of the northern
Rockies. Warm advection precip is developing ahead of the wave and
should move quickly east into the Midwest late tonight. Some minor
differences between model timing of onset. Still fair amount of
dry air evident in 00z KILX sounding, but dew points are climbing
as southerly wind component develops in the boundary layer. Have
made some minor adjustment to wx/pop grids late tonight and
tomorrow to reflect a compromise between HRRR and NAM precip fields.
&&
.SHORT TERM...(Tonight)
ISSUED AT 242 PM CDT SUN SEP 14 2014
High pressure across the Midwest and into the Atlantic northeast
will keep the weather quiet in the early evening hours, but give way
to another quick disturbance moving into the region tonight. A front
moving across the area tonight associated with the disturbance will
bring the chance for showers and isolated thunder into tomorrow
morning. Models have been delaying the precip until after midnight
and have maintained that trend, with pops starting to move in NW of
the Illinois River Valley before 12z. Some of the cloud cover moving
into the region should keep the temps from bottoming out, but still
unseasonably cool with lows in the upper 40s and near 50.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 242 PM CDT SUN SEP 14 2014
There is decent agreement in the models that the track of the best
forcing for precip on Monday looks to remain across northern
Illinois. Therefore we continued to limit the likely PoPs to areas N
of I-72, with chance PoPs south of there. Instability will be weak
at best, but a rumble of thunder could develop for SW areas from
Rushville to Jacksonville.
By Monday evening, any residual lift along a trailing trough will
diminish quickly. It`s entirely possible that all rain may come to
an end by sunset. However, with the forward progress of that trough
slowing, shower chances could linger for at least a few hours into
Monday evening, so we left chance PoPs in place toward I-70.
The widespread clouds and rain across northern areas will keep high
temps on Monday near 60, and we continued to trim numbers a few
degrees below guidance values. With rain holding off until afternoon
and some filtered sun expected south of I-70, highs should get into
the lower 70s.
The colder than normal conditions will last through at least
mid-week as high pressure extends from the Great Lakes and back into
Illinois. Dry conditions are expected, due to the deep layer of dry
air. A weather system approaches western IL on Wed, but all models
curl it to the southeast of IL as high pressure remains in control
of our region.
A stronger system moving across the northern states on Saturday will
drag a cold front across IL Sat night and Sunday. There appears to
be enough instability for a few thunderstorms as mid-level lapse
rates increase and deeper moisture arrives. Chance PoPs were
included Saturday west of I-55, and area-wide for Sat night and
Sunday associated with the frontal passage. Temperatures will warm into
the upper 70s/near 80 by Saturday, with Sunday a few degrees cooler
under clouds and showers.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1152 PM CDT SUN SEP 14 2014
Southerly winds have developed across the central Illinois
terminals this evening. Lift ahead of fast moving short-wave over
the plains is producing some virga echoes to the northwest of the
TAF sites late this evening. Moisture will continue to develop
ahead of the wave through the remainder of the night with the
column gradually becoming saturated. there will be an increasing
chance of precip reaching the surface at KPIA and possibly KBMI
and KSPI by 12z. 15/00z NAM has slowed the progress of the system
and latest HRRR also shows a delay in the system suggesting that
the passage of the cold front associated with the wave will be a
bit slower than the previous TAF package.
Elevated instability may be sufficient for some thunder during the
day ahead of the front. Will keep current metion of VCTS in KSPI
and KDEC but push timing back into the afternoon just ahead of
frontal passage.
Winds should shift to the North during the late afternoon and
early evening behind the front. Although the boundary layer
remains saturated through the night, winds appear to be significant
enough to keep vsbys at least MVFR. Will keep MVFR CIGS in place as
well as stratus appears to be more likely.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARKER
SHORT TERM...HJS
LONG TERM...SHIMON/25
AVIATION...BARKER/BAK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
323 AM CDT MON SEP 15 2014
.SHORT TERM /TODAY/...
ISSUED AT 323 AM CDT MON SEP 15 2014
PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS TODAY. MEAN
TROUGH CONTINUES TO ADVANCE THROUGH THE NRN CONUS THIS MORNING.
WEAK KINEMATICALLY FORCED PRECIP CONTINUES OVER SD/MN/WI JUST
BRUSHING NRN IA. THIS IS DRIVEN BY DPVA AHEAD OF POTENT DAKOTAS
SHORT WAVE/PV ANOMALY AND RIGHT ENTRANCE REGION OF GREAT LAKES JET
SEGMENT. FARTHER SOUTH WARM/THETA-E ADVECTION HAS STRENGTHENED IN
RESPONSE ALONG MO VALLEY BAROCLINIC AND FRONTOGENESIS ZONE.
INSTABILITY HAS INCREASED IN THIS RETURN FLOW WITH UNCAPPED 500
J/KG MUCAPES ENTERING SWRN IA...ROOTED 1-1.5KM. EFFECTIVE SHEAR IS
PUSHING 50KTS IN THIS AREA AND RESULTED IN A FEW SUB SEVERE HAIL
REPORTS OVER FAR ERN NE.
THIS THERMODYNAMIC FORCING AND INSTABILITY WILL BE LIMITED IN
TIME HOWEVER. RAP 305K ISENT SURFACE SHOWS THIS LIFT PUSHING
SOUTHWARD OUT OF THE STATE WITH TIME AS LONG WAVE TROUGH
APPROACHES. THIS WILL BRING MUCH OF THE STATE UNDER THE INFLUENCE
OF KINEMATIC RATHER THAN THERMODYNAMIC FORCING WHICH SHOULD SPREAD
INTO IA WITH TIME. MOISTURE WAS LIMITED INITIALLY BUT EXPECT
FORCING TO SOON INDUCE SATURATION AND MORE WIDESPREAD PRECIP. THE
PRONOUNCED SUBSIDENCE/LIFT COUPLET WILL BE EXITING ERN SECTIONS BY
18Z HOWEVER SO MUCH OF THE FORECAST AREA SHOULD BE DRY BY EARLY
AFTERNOON.
08Z SURFACE ANALYSIS APPEARS TO SHOW TWO FRONTS...ONE FROM KS/MO
TO BETWEEN CRESTON AND DES MOINES...WITH ANOTHER FROM THE AMES
AREA TO JUST SOUTH OF WATERLOO. THESE SHOULD QUICKLY PHASE AND
EXIT THE AREA BY 18Z PRODUCING PROBLEMATIC AND IN PLACES NON-
DIURNAL TEMP TRENDS. READINGS SHOULD REBOUND LITTLE SE WITH SYSTEM
EFFECTS LINGERING LONGER. HOWEVER FAR NW SHOULD SEE THE PRECIP END
EARLIER WITH CLEARING AND MORE POTENTIAL FOR MIXING AND REBOUND.
THIS RESULTS IN FAIRLY HOMOGENEOUS AND LOW CONFIDENCE TEMP
FORECAST IN THE LOWER 60S NEAR MOS GUIDANCE BLEND.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 323 AM CDT MON SEP 15 2014
FROM TONIGHT THROUGH THURSDAY THE WEATHER WILL BE DRY AND QUIET
WITH A SLOW WARMING TREND. A SURFACE HIGH PRESSURE AREA WILL BE
DRAPED ACROSS IOWA OVERNIGHT ALLOWING TEMPERATURES TO FALL INTO
THE UPPER 30S IN SOME AREAS...HOWEVER NO SIGNIFICANT FROST EFFECTS
ARE ANTICIPATED AS TEMPERATURES SHOULD NOT DROP TO THE LEVELS SEEN
ON SATURDAY MORNING. PATCHY TO POSSIBLY WIDESPREAD FOG DEVELOPMENT
IS ANTICIPATED PARTICULARLY IN AREAS WHERE RAIN FALLS THIS
MORNING. ON TUESDAY NIGHT AND WEDNESDAY A ZONE OF WARM AIR
ADVECTION JUST TO OUR SOUTHWEST SHOULD GENERATE SOME SHOWERS AND
STORMS FROM EASTERN NEBRASKA DOWN INTO MISSOURI...BUT THIS
ACTIVITY IS EXPECTED TO MISS OUR FORECAST AREA WITH JUST SOME
SLIGHT POPS MAINTAINED IN THE SOUTHWEST CORNER AND NO IMPACTS
EXPECTED.
BY THURSDAY LOW LEVEL WINDS WILL HAVE TURNED AROUND TO SOUTH
SOUTHEAST ALLOWING THE AFOREMENTIONED SLOW WARMING
TREND...MEANWHILE A DEEP LAYER THERMAL RIDGE WILL HAVE BUILT
DOWN THE HIGH PLAINS FROM THE DAKOTAS TO THE TEXAS PANHANDLE. THIS
RIDGE WILL SUBSEQUENTLY SHIFT EASTWARD...HOWEVER A 500 MB
SHORTWAVE MOVING AROUND ITS PERIPHERY WILL ALSO DIG DOWN ACROSS
MINNESOTA AND WISCONSIN AND FLATTEN THE RIDGE DOWN TOWARD THE
SOUTH. THIS SHORTWAVE WILL LIKELY GENERATE SOME THUNDERSTORMS FROM
THURSDAY NIGHT INTO FRIDAY...THE MAJORITY OF WHICH WILL REMAIN TO
OUR NORTHEAST BUT SOME MAY CLIP AREAS AROUND MASON CITY AND
WATERLOO AROUND FRIDAY MORNING. HAVE MAINTAINED CHANCE POPS TO
ACCOUNT FOR THIS. BY LATE IN THE DAY FRIDAY...IN WAKE OF THESE
STORMS...A WEAKLY DEFINED SURFACE TROUGH WILL BE DRAPED FROM
CENTRAL MINNESOTA DOWN TO WESTERN NEBRASKA. SOUTH OF THIS BOUNDARY
MOST OF OUR FORECAST AREA...ESPECIALLY THE SOUTHERN HALF...SHOULD
SEE MORE ROBUST WARMING WITH TEMPERATURES IN THE LOWER 80S
POSSIBLE. HOWEVER...THIS WILL BE BROUGHT TO A QUICK END AS ANOTHER
500 MB WAVE COMING OVER THE NORTHERN ROCKIES OF MONTANA WILL
RAPIDLY DEEPEN AS IT MOVES SOUTHEAST OVER THE MIDWEST ON FRIDAY
NIGHT AND SATURDAY. THIS WILL SHARPEN THE SURFACE TROUGH AND PUSH
IT ACROSS IOWA ON SATURDAY.
THE PASSAGE OF THE SURFACE FRONT AND MID LEVEL WAVE ON FRIDAY
NIGHT/SATURDAY WILL UNDOUBTEDLY TRIGGER SOME SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. HOWEVER...COVERAGE AND TIMING
REMAIN SOMEWHAT UNCERTAIN AND HAVE KEPT ONLY 40 TO 60 POPS IN EACH
PERIOD FOR NOW UNTIL SOLUTIONS CONVERGE. OF POTENTIALLY GREATER
CONSEQUENCE IS HURRICANE ODILE...WHICH IS CURRENTLY MAKING
LANDFALL OVER THE BAJA CALIFORNIA AND WILL DRIFT SLOWLY
NORTHEASTWARD OVER THE DESERT SOUTHWEST...REFLECTED BY A LARGE
SLUG OF DEEP MOISTURE AND A WEAKENING LOW PRESSURE CENTER. SOME
GFS SOLUTIONS HAVE BEEN ADVECTING THE MOISTURE FAR ENOUGH
NORTHEAST BY THE END OF THE WEEK THAT IT IS DRAWN UP ALONG THE
SURFACE FRONT...BRINGING A SIGNIFICANT HEAVY RAIN THREAT TO PARTS
OF THE REGION AND POTENTIALLY IOWA. HOWEVER...THESE SOLUTIONS HAVE
BEEN INCONSISTENT AND THE ECMWF HAS BEEN KEEPING THE ODILE
MOISTURE FAR ENOUGH TO THE SOUTHWEST THAT IT IS NOT DRAWN EASTWARD
UNTIL THE FRONT HAS ALREADY PASSED THROUGH IOWA. THIS PARTICULAR
SCENARIO IS UNSTABLE IN THE SENSE THAT IT RELIES ON THE SLOW DRIFT
OF A CYCLONE JUST MAKING LANDFALL...AS WELL AS THE TIMING AND
MOTION OF OTHER ATMOSPHERIC FEATURES THAT DO NOT EVEN EXIST YET.
WE WILL CONTINUE TO MONITOR THIS POTENTIAL THROUGHOUT THE WEEK.
&&
.AVIATION...15/06Z
ISSUED AT 1201 AM CDT MON SEP 15 2014
WEAK COLD FRONT FROM NERN IA INTO WEST CENTRAL IA WILL MOVE SOUTH
AND PASS SOUTH OF THE TAF SITES BY MONDAY MORNING. ISOLATED
SHOWERS WILL BECOME NUMEROUS LATER TONIGHT INTO MONDAY MORNING A
BRIEF PERIOD OF MVFR CIGS IS EXPECTED BEHIND THE COLD FRONT WITH
CONDITIONS IMPROVING QUICKLY FROM THE NORTHWEST AS HIGH PRESSURE
BUILDS INTO THE STATE.
OUTLOOK...HIGH PRESSURE WILL MOVE THROUGH IA AND PASS TO THE EAST
ON TUESDAY. WEATHER WILL BECOME MORE UNSETTLED FOR THE LAST HALF
OF THE WEEK.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...MS SEP 14
AREA FORECAST DISCUSSION
NWS TOPEKA KS
341 AM CDT Mon Sep 15 2014
.SHORT TERM...(Today and Tonight)
Issued at 339 AM CDT MON SEP 15 2014
An upper level trough across the northern and central plains will
move eastward across the Great Lakes States Today. The stronger
ascent ahead of this trough was occuring across the upper Midwest
early this morning. The stronger isentropic lift was occuring from
eastern NE into northwest MO and western IA. This area of stronger
isentropic lift will also shift eastward across northern MO, IA and
into the mid and upper MS river valley through the morning hours.
A surface cold front was moving southward across northwest KS and
extend northeast into eastern NE. The front was located just north
of CNK. The front should move south of the CWA by 100 PM.
Most of the models are showing only a trace to one hundredths of an
inch of QPF across the CWA this morning and into the early afternoon
hours. Our best chance for an isolated shower will probably occur
behind the surface cold front as weak isentropic lift develops after
FROPA. The forecast soundings show a warm nose developing at 800mb
which may not allow any parcels to reach their LFC, so odds are we
may not get any elevated thunderstorms behind the front. But just in
case there may be enough lift I kept isolated thunderstorms directly
behind the surface cold front for the morning and early afternoon
hours. The capping inversion looks too strong for any surface based
storms to develop early this afternoon ahead of the surface cold
front across the southeast counties of the CWA.
Highs Today will reach the upper 70s to lower 80s across the
southeast counties during the early afternoon hours but should fall
back through the 70s once the surface cold front shifts winds to the
north. The central counties may see highs reach the upper 60s to
lower 70s by early afternoon, then remain steady through the
afternoon hours behind the cold front. The north central counties
will be behind the surface cold front during the mid morning hours,
with highs only warming back into the mid to upper 60s during the
afternoon hours.
Tonight, Skies will clear as a surface ridge of high pressure builds
southward across eastern KS through the night. Lows will drop into
the mid 40s along the NE border to around 50 across the southeast
counties.
.LONG TERM...(Tuesday through Sunday)
Issued at 339 AM CDT MON SEP 15 2014
As the upper trough in the eastern CONUS shifts eastward and the
intermountain west upper ridge amplifies...the moisture and cooler
air that had been pushed to the south and west will begin to edge
back to the northeast primarily late Tuesday night into Wednesday
night. At the same time...a couple of weak shortwave troughs will
move southeast through the flow aloft and across the area...interacting
with the increasing waa/isentropic lift to provide chances for
showers and thunderstorms through this period.
There should be a break in precip chances Thursday night through the
day Friday as drier air aloft advects in and a capping inversion
strengthens as the upper level ridge axis moves across the area. As
the northern portions of the west coast trough shears eastward into
the northern and central plains by Friday night and
Saturday...another cold front should approach then traverse the cwa
Saturday before pushing south and east of the area by late Sunday.
The combination of the frontal passage and shortwave trough in the
presence of deeper tropical moisture surging out of the southwestern
U.S. should aid the development of showers and thunderstorms for at
least the first half of the weekend.
Following highs in the upper 60s and lower 70s on Tuesday...temps
should moderate back into the 70s and lower 80s Wednesday and
Thursday...then primarily the 80s Friday into Saturday prior to
arrival of the weak cold front.
&&
.AVIATION...(For the 06Z TAFs through 06Z Monday Night)
Issued at 1118 PM CDT SUN SEP 14 2014
00Z TOP RAOB showed 700 MB temps of +9C and new models runs show
this warm air aloft remaining over northeast KS for most of the
night. Now that the latest RAP and HRRR are trending dryer, do not
have enough confidence in carrying TS at the terminals. Still
looks like there could be a period of MVFR CIGS and VSBY behind
the FROPA and have not made any changes to this. Think that mixing
and some mid level clouds should prevent any stratus or fog from
forming ahead of the front, but this needs to be monitored.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...63
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1118 PM CDT Sun Sep 14 2014
...AVIATION UPDATE...
.SHORT TERM...(This Evening through Monday)
Issued at 327 PM CDT SUN SEP 14 2014
Kansas is on the south end of stronger northwest flow over the
Northern Plains with a shortwave trough diving southeast out of
southern Saskatchewan early this afternoon. Southerly low-level flow
returning locally with periods of stratus moving through under
still warm mid level air. Isentropic lift over this warm layer
leading to isolated showers over north central Kansas but doubt much
is reaching the ground through the warm/dry mid levels.
Main question through Monday is where elevated convection will be
focused. Isentropic lift persists and increases into the lower
levels tonight as the northern trough quickly rotates southeast into
northern Nebraska. NAM continues to be the more aggressive with
moistening around 6000 feet AGL but even its 18Z run struggles to
generate precipitation this far south, with stronger convergence to
the north. Have backed off on southern extent of higher chances
tonight and for most locations Monday. Front`s passage still occurs
under the warm nose keeping surface/mixed-layers storms in check
here, and also occurs by mid afternoon Monday for little time for
destabilization ahead of it. Any storms that can form tonight into
early Monday will need to be monitored for hail with elevated
instability potentially around 1000 J/kg and decent cloud-bearing
shear. Another round of more fall-like conditions is possible during
Monday with saturation deepening for at least minor drizzle
possibilities and falling afternoon temps but only made minor temp
adjustments at this range.
.LONG TERM...(Monday Night through Sunday)
Issued at 327 PM CDT SUN SEP 14 2014
Precipitation over the far southeast counties moves southeastward
quickly and leaves behind cooler high pressure for Monday night into
Tuesday. Lows in the 40s should still rise to lower 70s given
mostly sunny skies return for the afternoon. Wednesday and Thursday
the Central Plains remain the transitional area between the upper
ridge over the Rockies and the trough over the east coast, with mid
level warm front parked over the state. As this boundary slowly
migrates eastward, models consistent in generating very light QPF
through this period. In terms of probability, a slight chance is
warranted given the overall pattern, but confidence remains low on
timing or measurable precipitation. Highs in the lower to middle
70s rise to 70s and low 80s by Thursday, with lows in the 50s to
lower 60s as slow warming trend continues.
By the late hours on Thursday, EC and GFS differ on how to handle
dissipating hurricane over the west coast and its interaction with
the incoming longwave trough. GFS is faster and phases some of the
energy, deepening the trough and slowing its eastward progress. It
still takes some of the energy as a lead lobe out into the Plains
states and brings precipitation across eastern Kansas on Saturday.
EC takes a similar path with some of the northern energy, but cuts
off the merging upper trough and hurricane out over the Pacific. Still
with a FROPA on Saturday, sensible weather in either case remains
quite similar. Have kept chance pops for late Friday into Saturday,
diminishing quickly north to south on Saturday night. Might be able
to delay start time of the precip in later forecasts, but will just
have to watch how tropical and extratropical systems interact with
time. Fridays highs in the low 80s temper a bit into Saturday and
Sunday given precipitation followed by cold front, with highs in the
70s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Monday Night)
Issued at 1118 PM CDT SUN SEP 14 2014
00Z TOP RAOB showed 700 MB temps of +9C and new models runs show
this warm air aloft remaining over northeast KS for most of the
night. Now that the latest RAP and HRRR are trending dryer, do not
have enough confidence in carrying TS at the terminals. Still
looks like there could be a period of MVFR CIGS and VSBY behind
the FROPA and have not made any changes to this. Think that mixing
and some mid level clouds should prevent any stratus or fog from
forming ahead of the front, but this needs to be monitored.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...65
LONG TERM...67
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
455 AM EDT MON SEP 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT MON SEP 15 2014
LATEST WV IMAGERY AND RUC ANALYSIS SHOW A BROAD MID/UPPER LEVEL
TROUGH FROM CENTRAL CANADA INTO THE NRN CONUS WITH A SHORTWAVE NOTED
UPSTREAM OVER THE DAKOTAS. DPVA AND MOISTURE AHEAD OF THIS SHORTWAVE
WAS SUPPORTING A MASS OF CLOUDS ALONG WITH SCT SHRA OVER THE SRN
HALF OF MN AND CENTRAL WI. THE NRN EDGE OF THE MID-HIGH CLOUD SHIELD
WAS REACHING INTO THE SCNTRL PORTION OF UPPER MI WHILE THE REST OF
THE FORECAST AREA WAS GENERALLY CLOUD FREE EARLY THIS MORNING.
TODAY...MODELS SHOW SOME WEAK Q-VECT CONV ASSOC WITH UPPER TROUGH
OVERHEAD AND ON NRN EDGE OF FORCING FROM DAKOTAS SHORTWAVE PASSING
SOUTH. SBCAPE OF 50-100 J/KG ALONG WITH SFC-7H LAPSE RATES OF 7.5C
OR HIGHER WHICH COULD SUPPORT SOME SCATTERED LIGHT SHOWERS OR
SPRINKLES AS DAYTIME HEATING INCREASES. BEST CHANCE FOR SHRA WILL BE
CENTRAL AND EAST WHERE AWAY FROM LAKE SUPERIOR WHERE BETTER DAYTIME
HEATING IS EXPECTED. WL MAINTAIN SLIGHT CHC POPS FOR THESE
COUNTIES.
TONIGHT...CLEARING SKIES AND LIGHT WINDS OVER THE WESTERN INTERIOR
ALONG WITH PWAT VALUES AOB 50 PCT OF NORMAL SHOULD SUPPORT AREAS OF
FROST AS MIN TEMPS DIP NEAR THE FREEZING MARK ESPECIALLY ALONG THE
WI BORDER. HAVE INCLUDED GOGEBIC...ONTONAGON...IRON...BARAGA...SRN
HOUGHTON AND DICKINSON COUNTIES IN A FROST ADVISORY FOR LATE TONIGHT
INTO EARLY TUE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 332 AM EDT MON SEP 15 2014
OVERALL PATTERN IS WELL AGREED ON BY MODELS THROUGH NEXT WEEKEND.
UPPER LEVEL PATTERN TUE AND WED WILL FEATURE A RIDGE OVER THE WRN
CONUS AND A TROUGH OVER THE ERN CONUS. PATTERN BEGINS TO BREAK DOWN
THU...WITH A WEAK TROUGH MOVING ACROSS THE NCENTRAL CONUS LATE FRI
AND SAT.
SFC HIGH PRESSURE WILL MAKE FOR A DRY AND SUNNY TUE WITH HIGH TEMPS
EVEN AROUND NORMAL IN THE MID TO UPPER 60S.
A SHORTWAVE TROUGH WILL MOVE ACROSS FAR NRN QUEBEC ON TUE...DROPPING
THE ASSOCIATED COLD FRONT DOWN FROM THE NNE TUE NIGHT INTO WED AS
ANOTHER WEAKER SHORTWAVE DROPS DOWN ALONG THE FRONT. MOST MODELS
SHOWING QPF ALONG THE FRONT AND AHEAD OF THE SHORTWAVE...BUT EXACT
TIMING AND PLACEMENT IS STILL SOMEWHAT DISAGREED ON. WILL INCREASE
POPS GIVEN THE INCREASED CONFIDENCE IN PRECIP OCCURRING. WED LOOKS
QUITE A BIT COOLER THAN TUE...MAINLY OVER THE NRN HALF OF THE CWA
WHERE THE FRONT WILL PASS THROUGH EARLIER. EXPECT HIGHS RANGING FROM
AROUND 50 ALONG LAKE SUPERIOR TO 60 OVER THE SCENTRAL. ECMWF AND GEM
SHOW LIGHT QPF OVER THE CWA LATE WED INTO WED NIGHT...BUT WITH A
1025MB SFC HIGH CENTER OVER OR NEAR THE CWA DURING THIS TIME...WILL
LEAN TOWARD THE DRIER GFS AND NAM SOLUTIONS. MAY SEE FROST OVER
INTERIOR ERN UPPER MI WED NIGHT...BUT THE TEMPS WILL BE DEPENDENT ON
CLOUD COVER AND PRECIP CHANCES. WILL KEEP A COLD FORECAST WITH FROST
GIVEN PREFERENCE FOR DRIER SOLUTIONS.
THU LOOKS MOSTLY DRY...BUT RAIN CHANCES WILL INCREASE THU NIGHT
THROUGH SAT. INITIALLY...PRIMARY DRIVER FOR THE PRECIP WILL BE
WAA/ISENTROPIC LIFT RESULTING FROM BEEFY SSWLY LOW LEVEL FLOW
BETWEEN THE IMPENDING SFC TROUGH AND DEPARTING SFC HIGH. FORCING
THEM TRANSITIONS TO LARGE SCALE FORCING ALONG THE UPPER/SFC TROUGHS
ON SAT...BUT WILL RECEIVE AT LEAST SOME ADDITIONAL FORCING FROM
INSTABILITY. MODELS SHOW UP TO 700J/KG OF CAPE ON SAT...BUT THAT
WILL BE HIGHLY DEPENDENT ON CLOUD COVER AND OTHER FACTORS. THERE IS
POTENTIAL FOR DECENT CAPE GIVEN POSSIBILITY OF HOT SFC TEMPS AS
850MB TEMPS INCREASE TO 16C AHEAD OF THE COLD FRONT LAKE FRI NIGHT
INTO SAT. WILL NEED CONTINUE TO ASSESS THE SEVERE THREAT AS THE EVEN
APPROACHES.
COOLER AND DRIER WEATHER LOOKS TO BE IN STORE FOR SUN AS A SFC HIGH
MOVES INTO THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 114 AM EDT MON SEP 15 2014
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT MON SEP 15 2014
HIGH PRESSURE MOVING OVER THE AREA WILL MAINTAIN WINDS GENERALLY
LESS THAN 20 KT TODAY. WSW WINDS MAY INCREASE TO 25 KTS MONDAY NIGHT
INTO TUESDAY AHEAD OF A COLD FRONT. WINDS THEN SHIFT TO NORTHEAST UP
TO 25 KTS IN THE WAKE OF THE COLD FRONT TUESDAY NIGHT. WINDS
DIMINISH TO LESS THAN 20 KTS LATER WED INTO THU AS HIGH PRESSURE
RIDGE CROSSES REGION. NEXT CHANCE OF STRONG WINDS ARRIVES FRIDAY
WITH SOUTH WINDS INCREASING TO 20 TO 30 KTS AHEAD OF DEVELOPING LOW
PRESSURE SYSTEM IN THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 9 AM EDT
/8 AM CDT/ TUESDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
333 AM EDT MON SEP 15 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 401 PM EDT SUN SEP 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM CENTRAL CANADA INTO THE NRN CONUS. A SHORTWAVE TROUGH WAS
MOVING THROUGH NRN ONTARIO JUST N OF LAKE SUPERIOR WHILE THE MOST
PROMINENT UPSTREAM SHRTWV WAS DIVING INTO ERN MONTANA. AT THE
SFC...LOW PRES NEAR CYQT HAD DRAGGED A COLD FRONT THROUGH WRN UPPER
MI. THE SHRTWV TAIL AHEAD OF THE COLD FRONT WITH MODERATE 700-300
QVECTOR CONV WAS ENOUGH TO SUPPORT SCT LIGHT SHOWERS OR SPRINKLES
FROM ERN LAKE SUPERIOR INTO CNTRL UPPER MI. RELATIVELY DRY LOW LEVEL
AND THE QUICK MOVEMENT OF THE SHOWERS HAS LIMITED POTENTIAL FOR MORE
THAN TRACE PCPN AMOUNTS. OTHERWISE...PARTIAL CLEARING WAS MOVING
INTO W UPPER MI WITH A PROMINENT CU FIELD IN THE SEASONABLY COOL
AIRMASS WHERE 850 MB TEMPS WERE NEAR 4C.
TONIGHT...AS THE SHRTWV TROUGH EXITS TO THE EAST...EXPECT THE
REMAINING SHOWERS OVER THE ERN CWA TO DIMINISH THROUGH THE LATE
AFTERNOON AND EARLY EVENING. PARTLY CLOUDY SKIES AND DIMINISHING
WINDS WILL RESULT IN FAVORABLE RADIATIONAL COOLING CONDITIONS LATE
THIS EVENING. HOWEVER...THERE IS UNCERTAINTY ON HOW MUCH CLOUD COVER
WILL HOLD TOGETHER OVERNIGHT AS ADDITIONAL MOISTURE WILL SLIDE IN
WITH 850 MB TEMPS DROPPING TO NEAR 1C. EXPECT MIN READINGS TO DROP
INTO THE UPPER 30S AND LOWER 40S INLAND.
MONDAY...MODELS WERE IN GOOD AGREEMENT THAT THE STRONGEST QVECTOR
CONV AND PCPN ASSOCIATED WITH THE MONTANA SHRTWV WILL REMAIN SOUTH
OF UPPER MI. HOWEVER...THERE MAY BE ENOUGH LOW LEVEL MOISTURE
COMBINED WITH 850 MB TEMPS NEAR 1C TO SUPPORT SOME SHALLOW
CONVECTION WITH SCATTERED LIGHT SHOWERS OR SPRINKLES AS DAYTIME
HEATING INCREASES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 332 AM EDT MON SEP 15 2014
OVERALL PATTERN IS WELL AGREED ON BY MODELS THROUGH NEXT WEEKEND.
UPPER LEVEL PATTERN TUE AND WED WILL FEATURE A RIDGE OVER THE WRN
CONUS AND A TROUGH OVER THE ERN CONUS. PATTERN BEGINS TO BREAK DOWN
THU...WITH A WEAK TROUGH MOVING ACROSS THE NCENTRAL CONUS LATE FRI
AND SAT.
SFC HIGH PRESSURE WILL MAKE FOR A DRY AND SUNNY TUE WITH HIGH TEMPS
EVEN AROUND NORMAL IN THE MID TO UPPER 60S.
A SHORTWAVE TROUGH WILL MOVE ACROSS FAR NRN QUEBEC ON TUE...DROPPING
THE ASSOCIATED COLD FRONT DOWN FROM THE NNE TUE NIGHT INTO WED AS
ANOTHER WEAKER SHORTWAVE DROPS DOWN ALONG THE FRONT. MOST MODELS
SHOWING QPF ALONG THE FRONT AND AHEAD OF THE SHORTWAVE...BUT EXACT
TIMING AND PLACEMENT IS STILL SOMEWHAT DISAGREED ON. WILL INCREASE
POPS GIVEN THE INCREASED CONFIDENCE IN PRECIP OCCURRING. WED LOOKS
QUITE A BIT COOLER THAN TUE...MAINLY OVER THE NRN HALF OF THE CWA
WHERE THE FRONT WILL PASS THROUGH EARLIER. EXPECT HIGHS RANGING FROM
AROUND 50 ALONG LAKE SUPERIOR TO 60 OVER THE SCENTRAL. ECMWF AND GEM
SHOW LIGHT QPF OVER THE CWA LATE WED INTO WED NIGHT...BUT WITH A
1025MB SFC HIGH CENTER OVER OR NEAR THE CWA DURING THIS TIME...WILL
LEAN TOWARD THE DRIER GFS AND NAM SOLUTIONS. MAY SEE FROST OVER
INTERIOR ERN UPPER MI WED NIGHT...BUT THE TEMPS WILL BE DEPENDENT ON
CLOUD COVER AND PRECIP CHANCES. WILL KEEP A COLD FORECAST WITH FROST
GIVEN PREFERENCE FOR DRIER SOLUTIONS.
THU LOOKS MOSTLY DRY...BUT RAIN CHANCES WILL INCREASE THU NIGHT
THROUGH SAT. INITIALLY...PRIMARY DRIVER FOR THE PRECIP WILL BE
WAA/ISENTROPIC LIFT RESULTING FROM BEEFY SSWLY LOW LEVEL FLOW
BETWEEN THE IMPENDING SFC TROUGH AND DEPARTING SFC HIGH. FORCING
THEM TRANSITIONS TO LARGE SCALE FORCING ALONG THE UPPER/SFC TROUGHS
ON SAT...BUT WILL RECEIVE AT LEAST SOME ADDITIONAL FORCING FROM
INSTABILITY. MODELS SHOW UP TO 700J/KG OF CAPE ON SAT...BUT THAT
WILL BE HIGHLY DEPENDENT ON CLOUD COVER AND OTHER FACTORS. THERE IS
POTENTIAL FOR DECENT CAPE GIVEN POSSIBILITY OF HOT SFC TEMPS AS
850MB TEMPS INCREASE TO 16C AHEAD OF THE COLD FRONT LAKE FRI NIGHT
INTO SAT. WILL NEED CONTINUE TO ASSESS THE SEVERE THREAT AS THE EVEN
APPROACHES.
COOLER AND DRIER WEATHER LOOKS TO BE IN STORE FOR SUN AS A SFC HIGH
MOVES INTO THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 114 AM EDT MON SEP 15 2014
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 350 PM EDT SUN SEP 14 2014
SW WINDS GUST TO 25 KTS THROUGH EARLY THIS EVENING...THEN WEST
WINDS DIMINISH TO LESS THAN 20 KTS LATER TONIGHT INTO MONDAY. WEST
WINDS MAY INCREASE TO 25 KTS MONDAY NIGHT INTO TUESDAY AHEAD OF A
COLD FRONT. WINDS THEN SHIFT TO NORTHEAST UP TO 25 KTS IN WAKE OF
THE COLD FRONT TUESDAY NIGHT. WINDS DIMINISH TO LESS THAN 20 KTS
LATER WED INTO THU AS HIGH PRESSURE RIDGE CROSSES REGION. NEXT
CHANCE OF STRONG WINDS ARRIVES FRIDAY WITH SOUTH WINDS INCREASING
TO 20 TO 30 KTS AHEAD OF DEVELOPING LOW PRESSURE SYSTEM IN THE
PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 9 AM EDT
/8 AM CDT/ TUESDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
115 AM EDT MON SEP 15 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 401 PM EDT SUN SEP 14 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM CENTRAL CANADA INTO THE NRN CONUS. A SHORTWAVE TROUGH WAS
MOVING THROUGH NRN ONTARIO JUST N OF LAKE SUPERIOR WHILE THE MOST
PROMINENT UPSTREAM SHRTWV WAS DIVING INTO ERN MONTANA. AT THE
SFC...LOW PRES NEAR CYQT HAD DRAGGED A COLD FRONT THROUGH WRN UPPER
MI. THE SHRTWV TAIL AHEAD OF THE COLD FRONT WITH MODERATE 700-300
QVECTOR CONV WAS ENOUGH TO SUPPORT SCT LIGHT SHOWERS OR SPRINKLES
FROM ERN LAKE SUPERIOR INTO CNTRL UPPER MI. RELATIVELY DRY LOW LEVEL
AND THE QUICK MOVEMENT OF THE SHOWERS HAS LIMITED POTENTIAL FOR MORE
THAN TRACE PCPN AMOUNTS. OTHERWISE...PARTIAL CLEARING WAS MOVING
INTO W UPPER MI WITH A PROMINENT CU FIELD IN THE SEASONABLY COOL
AIRMASS WHERE 850 MB TEMPS WERE NEAR 4C.
TONIGHT...AS THE SHRTWV TROUGH EXITS TO THE EAST...EXPECT THE
REMAINING SHOWERS OVER THE ERN CWA TO DIMINISH THROUGH THE LATE
AFTERNOON AND EARLY EVENING. PARTLY CLOUDY SKIES AND DIMINISHING
WINDS WILL RESULT IN FAVORABLE RADIATIONAL COOLING CONDITIONS LATE
THIS EVENING. HOWEVER...THERE IS UNCERTAINTY ON HOW MUCH CLOUD COVER
WILL HOLD TOGETHER OVERNIGHT AS ADDITIONAL MOISTURE WILL SLIDE IN
WITH 850 MB TEMPS DROPPING TO NEAR 1C. EXPECT MIN READINGS TO DROP
INTO THE UPPER 30S AND LOWER 40S INLAND.
MONDAY...MODELS WERE IN GOOD AGREEMENT THAT THE STRONGEST QVECTOR
CONV AND PCPN ASSOCIATED WITH THE MONTANA SHRTWV WILL REMAIN SOUTH
OF UPPER MI. HOWEVER...THERE MAY BE ENOUGH LOW LEVEL MOISTURE
COMBINED WITH 850 MB TEMPS NEAR 1C TO SUPPORT SOME SHALLOW
CONVECTION WITH SCATTERED LIGHT SHOWERS OR SPRINKLES AS DAYTIME
HEATING INCREASES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 350 PM EDT SUN SEP 14 2014
MODEL AGREEMENT IS GOOD IN THE EVOLUTION OF OVERALL LARGE SCALE
PATTERN INTO NEXT WEEKEND. TROUGHS CENTERED OVER ALASKA AND NUNAVUT
IN NORTHERN CANADA ARE EXPECTED TO DEAMPLIFY WITH FLOW ALOFT OVER
THE NORTHERN CONUS BECOMING MORE ZONAL THROUGH THE PERIOD. UNTIL
MIDWEEK THE TROUGH OVER THE GREAT LAKES AND ACROSS EASTERN CANADA
WILL KEEP GETTING REINORCED AS UPPER JET ENERGY DIGGING SSE OVER
WESTERN CANADA SLIDES INTO BASE OF TROUGH. STRONGER SHORTWAVE
WITHIN THE TROUGH CROSSES NORTHERN ONTARIO MONDAY NIGHT AND MOVES
INTO QUEBEC ON TUESDAY. COLD FRONT TIED TO THAT WAVE ALONG WITH
ANOTHER SHEARED OUT SHORTWAVE AND RIBBON OF HIGHER H85-H7 RH MAY
RESULT IN LGT RAIN OR SHOWERS TURSDAY NIGHT INTO WEDNESDAY AND
POSSIBLY EVEN INTO WEDNESDAY NIGHT IF THE ECMWF AND GEM-NH ARE ON
THE RIGHT TRACK. MAIN IMPACT WILL BE A NOTICABLE COOLER DAY ON
WEDNESDAY COMPARED TO TUESDAY WHERE TEMPS WILL ACTUALLY BE AROUND OR
EVEN SLIGHTLY ABOVE NORMAL /NORMAL HIGHS AVERAGE THE MID 60S FOR
MID SEPT/.
SFC HIGH PRESSURE BUILDS ACROSS WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT IN CONFLUENT FLOW IN UPPER LEVELS BTWN RIDGING EXPANDING OVER
THE WESTERN CONUS AND DEPARTING TROUGH OVER EASTERN CANADA. MAINLY
DRY WEATHER ALONG WITH PARTLY CLOUDY OR MOSTLY CLEAR SKIES SHOULD
RESULT. STILL COULD BE CHILLY OVER THE INLAND AREAS ON WEDNESDAY
NIGHT WITH FROST. HOWEVER...BASED ON THAT SIGNAL OF MID-LEVEL
MOISTURE RIBBON FM ECMWF/GEM-NH...LOWEST TEMPS AND GREATEST RISK OF
FROST MIGHT END UP OVER THE INTERIOR EAST CWA.
BY LATE THIS WEEK...RIDGING OVER THE WESTERN CONUS IS REPLACED BY
TROUGHING AS SHORTWAVE AND UPPER JET STREAKS CURRENTLY OVER PACIFIC
WELL OFFSHORE OF WESTERN CONUS COAST SLIDES ACROSS THE NORTHERN AND
CENTRAL PLAINS WITH A SFC TROUGH ALSO PUSHING WEST TO EAST. MAIN
QUESTION IS HOW QUICKLY THIS OCCURS. NO REAL TREND IN THE MODEL
GUIDANCE...AS THE ECMWF AND GFS HAVE JUMPED AROUND IN HOW QUICKLY TO
BRING THE TROUGH AND INITIAL SURGE OF H85 THETA-E ADVECTION ACROSS
THE NORTHERN PLAINS AND DOWNSTREAM INTO THE UPPER GREAT LAKES. ONCE
THE FRONT...AND MORE SO THE THETA-E ADVECTION AHEAD OF THE FRONT...
ARRIVES COULD BE MULTIPLE ROUNDS OF SHRA/TSRA LATER FRIDAY THROUGH
SATURDAY WITH MAINLY JUST SHRA ON SUNDAY. HEAVY RAINS POSSIBLE SINCE
THE SFC FRONT WOULD BE PARALLEL TO THE UPPER LEVEL FLOW AND PWATS
ARE FORECAST 200-250 PCT OF NORMAL. AT FIRST GLANCE AND IT IS JUST
THAT...LOOKS LIKE ONLY A SMALLER RISK OF SEVERE WX AS INITIAL
ELEVATED INSTABILITY...MAYBE UP TO 500 J/KG...ON FRIDAY/FRIDAY NIGHT
DOES NOT LINK UP WITH MUCH EFFECTIVE SHEAR. THEN AS PRIMARY FRONT
COMES THROUGH EITHER SATURDAY AS IT LOOKS NOW...APPEARS BETTER
MLCAPE REMAINS SOUTH OF THE AREA CLOSER TO AREA OF 65F SFC DWPNTS.
ALL THAT SAID...GIVEN THE STRONG WINDS ALOFT THAT WILL BE
PRESENT...IF INSTABILITY ENDS UP GREATER THAN FORECAST...WOULD BE AT
LEAST SOME RISK OF STRONGER STORMS FRIDAY THROUGH SUNDAY. MAX TEMPS
BOTH FRI AND SAT MAY TRY TO REACH 70 DEGREES IF THERE IS ENOUGH
BREAKS IN THE CLOUD COVER AS H85 TEMPS ARE WELL ABOVE +12C. A BIT
LOWER TEMPS NEXT SUNDAY...THOUGH COOLDOWN WILL NOT BE AS MUCH AS
THAT EXPECTED ON WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 114 AM EDT MON SEP 15 2014
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 350 PM EDT SUN SEP 14 2014
SW WINDS GUST TO 25 KTS THROUGH EARLY THIS EVENING...THEN WEST
WINDS DIMINISH TO LESS THAN 20 KTS LATER TONIGHT INTO MONDAY. WEST
WINDS MAY INCREASE TO 25 KTS MONDAY NIGHT INTO TUESDAY AHEAD OF A
COLD FRONT. WINDS THEN SHIFT TO NORTHEAST UP TO 25 KTS IN WAKE OF
THE COLD FRONT TUESDAY NIGHT. WINDS DIMINISH TO LESS THAN 20 KTS
LATER WED INTO THU AS HIGH PRESSURE RIDGE CROSSES REGION. NEXT
CHANCE OF STRONG WINDS ARRIVES FRIDAY WITH SOUTH WINDS INCREASING
TO 20 TO 30 KTS AHEAD OF DEVELOPING LOW PRESSURE SYSTEM IN THE
PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLA
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1202 AM CDT MON SEP 15 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 246 PM CDT SUN SEP 14 2014
ALTHOUGH NOWHERE NEAR AS INTERESTING ON SATELLITE AS HURRICANE ODILE
IN THE ERN PAC...WATER VAPOR IMAGERY WITH RAP H5 ANALYSIS DOES SHOW
A STRONG WAVE CURRENTLY WORKING SOUTH ACROSS MANITOBA. THIS WAVE
WILL DIVE SE ACROSS NODAK AND SRN MN TONIGHT AND ACROSS CENTRAL WI
MONDAY. THIS IS A PRETTY POTENT WAVE...WITH THE NAM SHOWING THE 1.5
PV SFC /APPROXIMATE TROPOPAUSE LEVEL/ GETTING DOWN TO H5. BESIDE THE
PV ADVECTION OUT AHEAD OF THE WAVE...A FAIRLY STRONG BAND OF FGEN
WILL BE SETTING UP ACROSS SRN MN IN THE H7-H6 LAYER.
HOWEVER...CONCURRENT WITH THIS FORCING IN THE H7-H6 LAYER IS A VERY
DRY LAYER OF AIR BETWEEN H8 AND H7 THAT RAP SOUNDINGS SHOW NOW BEING
IN PLACE ACROSS THE AREA. MAJORITY OF SHORT TERM MODELS /BOTH CAMS
AND NON-CAMS/ SHOW THIS DEFORMATION BAND SETTING UP FROM RWF TO THE
SRN TWIN CITIES METRO AND OVER TO EAU. ALTHOUGH WE HAVE THAT DRY AIR
TO WORK WITH...FORCING LOOKS TO BE AROUND LONG ENOUGH TO ALLOW LIGHT
RAIN TO FALL ALONG THE LINE MENTIONED ABOVE. MAY SEE RAIN FOR
SEVERAL HOURS TONIGHT...BUT WILL BE A STRUGGLE TO EVEN GET TO A
TENTH OF AN INCH. WHAT THIS DRY AIR WILL DO IS RESULT IN A VERY
TIGHT PRECIP GRADIENT...WITH POP FORECAST AS OF 3 PM HAVING NEAR 50
POPS DOWN TOWARD LAKEVILLE...WITH NEAR ZERO BY THE TIME YOU GET TO
ANOKA.
AFTER 6Z...A STRONGER BURST OF RAIN LOOKS TO COME INTO SW MN AND
TRACK ACROSS I-90 THROUGH 12Z AND THIS IS ASSOCIATED WITH THE PV
FEATURE MOVING THROUGH. THIS AREA OF PRECIP LOOKS TO BE A BIT MORE
EFFICIENT AT PRODUCING RAIN...SO WENT WITH AN ECMWF/GFS/HPC QPF
BLEND...WHICH RESULTED ABOUT A QUARTER INCH OF RAIN FORECAST BETWEEN
MKT AND THE IOWA BORDER TONIGHT ALONG WITH CATEGORICAL POPS.
FOR TEMPERATURES...DID BOOST LOWS SOME ACROSS SRN MN...WHERE CLOUDS
WILL LIMIT THE AMOUNT OF COOLING...BUT VERY LITTLE CHANGE WAS MADE
TO THE FORECAST TOMORROW...AS SKIES LOOK TO CLEAR OUT IN THE
MORNING...WITH A BEAUTIFUL EARLY FALL DAY ENSUING THEREAFTER WITH
HIGHS IN THE UPPER 50S TO MID 60S...CLOSE TO WHAT A BLEND OF THE
BIAS CORRECTED RAW MODEL GUIDANCE GIVES YOU.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 246 PM CDT SUN SEP 14 2014
A SURFACE HIGH BUILDS IN ACROSS THE FORECAST AREA ON MONDAY AS THE
RAIN AND CLOUD COVER MOVE OUT DURING THE AFTERNOON. A DRY AND COOL
ATMOSPHERIC COLUMN IS EXPECTED TUESDAY THROUGH THURSDAY. TUESDAY
COULD STILL BE QUITE COOL AS MN/WI REMAIN ON THE BACK SIDE OF AN
850MB COLD POCKET STRETCHING EASTWARD TOWARD THE GREAT LAKES.
THERE IS A WEAK SURFACE TROUGH AND INSTABILITY POOLING ALONG A
MOISTURE AXIS STRETCHING FROM THE SOUTHERN PLAINS INTO NORTH
CENTRAL SD TUESDAY/TUESDAY NIGHT...BUT THERE DOESN`T SEEM TO BE
MUCH CONVERGENCE AT THIS TIME AND THE BOUNDARY WOULD REMAIN WELL
SOUTHWEST OF THE AREA ANYWAY. SO...ZERO POPS IT IS TUESDAY AND
WEDNESDAY. THERE IS 925-850MB WARM ADVECTION ON WEDNESDAY AND
THURSDAY...SO THERE COULD BE A LITTLE MORE WARMING THAN WHAT IS
CURRENTLY IN THE FORECAST. WHILE MONDAY AND TUESDAY SHOULD FEATURE
PLENTY OF 60S DURING THE AFTERNOON...THERE IS THE POTENTIAL FOR
LOW 70S IN MN WEDNESDAY AND THURSDAY AFTERNOON. IT ALSO LOOKS LIKE
OVERNIGHT LOWS IN THE COMING WEEK SHOULD BE WELL ABOVE THE
FREEZING MARK...SO THERE IS VERY LITTLE THREAT OF MORNING FROST
THIS COMING WEEK.
THE NEXT CHANCE FOR PRECIP AFTER MONDAY WILL HAVE TO WAIT UNTIL AT
LEAST FRIDAY WHEN BOTH THE 14.12Z GFS/ECMWF DEPICT LIGHT QPF ACROSS
THE FORECAST AREA. THE MODELS DON`T REALLY SHOW MUCH MOISTENING BELOW
700MB BEFORE SHORTWAVE ENERGY MAKES IT INTO THE EASTERN HALF OF
MN...SO MUCH OF THE FORECAST AREA MIGHT END UP WITH VERY LIGHT RAIN
OR VIRGA DURING THE DAY ON FRIDAY /OR NOTHING/.
NONETHELESS...THERE IS GOOD LOW LEVEL SOUTHWEST FLOW AND
TEMPERATURE ADVECTION DURING THE DAY WITH A MODEST INCREASE IN
INSTABILITY...ESPECIALLY IN WESTERN AND SOUTHERN MN. THE TIMING OF
THE WAVE THROUGH THE DAY ON FRIDAY AND INTO SATURDAY IS STILL
UNCERTAIN. THE 12Z ECMWF IS FASTER THAN THE GFS...AND THE GFS ALSO
DEVELOPS A WEAK SECONDARY LOW NEAR THE COLD FRONT AND SATURDAY.
THIS WOULD PROLONG THE PRECIP WELL INTO THE WEEKEND...HOWEVER...THE
LAST 4-5 RUNS OF THE GFS HAVE REALLY LACKED CONSISTENCY. WE ARE
CARRYING CHANCE POPS FOR SHOWERS WITH EMBEDDED THUNDER FOR NOW
WITH THAT THE IDEA THAT A BROKEN BAND OF SHOWERS WILL SWING
THROUGH WITH THE COLD FRONT FRIDAY NIGHT OR SATURDAY MORNING. IF
THERE IS A LESSON TO BE LEARNED OVER THE PAST COUPLE MONTHS...IT`S
THAT THE HEAVIER SHOWERS AND MORE ROBUST THUNDERSTORMS WILL END UP
SOUTH OF THE FORECAST AREA IN IOWA AND PORTIONS OF IL AND SOUTHERN
WI...WHERE THE HIGHEST INSTABILITY IS FORECAST TO BE LOCATED.
STILL SOME TIME TO WORK THIS LATE WEEK SYSTEM OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1155 PM CDT SUN SEP 14 2014
RAIN CONTINUES TO STRUGGLE DEVELOPING DUE TO THE AMOUNT OF DRY AIR
ACROSS THE UPPER MIDWEST. STILL THINK AREAS AROUND AND SOUTH/EAST
OF RWF HAVE A GOOD SHOT AT SEEING RAIN OVERNIGHT...BUT THINK IT
WILL MISS THE OTHER TAF SITES. VFR CONDITIONS THROUGH THE PERIOD.
KMSP...VFR CONDITIONS UNTIL FURTHER NOTICE. MID LEVEL CLOUDS WILL
DISSIPATE MONDAY AFTERNOON WITH NORTHWEST WINDS SLOWLY BACKING
SOUTHWEST MONDAY NIGHT.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS SW AT 10 KTS.
WED...VFR. WINDS SSE AT 5 KTS.
THU...VFR. WINDS SE AT 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
220 AM EDT MON SEP 15 2014
.SYNOPSIS...
HIGH PRESSURE WILL RESIDE OVER THE AREA TODAY PROVIDING DRY
WEATHER AND COOL TEMPERATURES. THE FIRST PATCHY FROST IS
POSSIBLE...MAINLY THE UPPER SUSQUEHANNA...WESTERN CATSKILLS...AND
TUG HILL PLATEAU REGIONS OF NEW YORK. TONIGHT INTO EARLY TUESDAY
MORNING A COLD FRONT WILL PASS THROUGH THE AREA BRINGING A PERIOD
OF SHOWERS. TEMPERATURES WILL REMAIN ON THE COOL SIDE THE NEXT
SEVERAL DAYS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1230 AM...CLOUD SHIELD OF 4-5K FT CIGS CONTINUE TO ADVANCE EAST
ACROSS FA AND ARE NOW MOVING INTO THE WESTERN CATSKILLS. SATELLITE
ANIMATION INDICATES THIS CLOUD COVER WILL REMAIN OVER THE REGION
FOR MUCH OF THE OVERNIGHT PERIOD AND WITH DEW POINTS IN THE LOWER
TO MIDDLE 40S ATTM WIDESPREAD FROST FORMATION LOOKS UNLIKELY IN
THE ADVISORY AREAS. SCATTERED FROST IS STILL POSSIBLE IN PARTS OF
THE WESTERN CATSKILLS AND WESTERN MOHAWK VALLEY. ADJUSTED TEMPS
AND CLOUD COVER AND WILL CONTINUE WITH FLAGS FOR NOW AND MOST
LIKELY CANCEL PARTS OR ALL OF ADVISORY AT 4 AM.
945 PM UPDATE...
CLOUD SHIELD ADVANCING THROUGH CENTRAL NY AS PER MODEL GUIDANCE.
FROST LIKELIHOOD LOOKING RATHER LOW FOR STEUBEN COUNTY, A BIT
HIGHER CHANCES ACROSS THE CATSKILLS. PER DISCUSSION BELOW I
THOUGHT ABOUT TAKING OUT STEUBEN COUNTY. WITH SOME BREAKS IN THE
CLOUDS TO THE WEST, WILL TAKE THE PATH OF LEAST REGRET AND LEAVE
ADVISORY IN PLACE. WITH THAT SAID THE FORECAST ITSELF IS MAINLY
37-40 IN THESE AREAS, WITH PATCHY FROST/FOG OVER ONLY A 2 HOUR
WINDOW. BOTTOM-LINE IS MOST OF THESE ARES WILL PROBABLY STAY FROST
FREE DUE TO CURRENT CLOUD COVER.
825 PM UPDATE...
MADE SOME MAJOR ADJUSTMENTS TO THE GRIDS TO INCREASE SKY COVER
THROUGH THE FINGER LAKES/WESTERN SOUTHERN TIER AND LOWER
PROBABILITY OF FROST/FOG HERE WHILE RAISING TEMPS SLIGHTLY. IT APPEARS
THE NAM MODEL WAS CORRECT AS CURRENT 11-3.9 MICRON SATELLITE ALONG
WITH OBS CONFIRM AN EXTENSIVE CLOUD SHIELD AROUND 5KFT OVER THE
WESTERN HALF OF THE CWA. THIS THIN LAYER WAS FIRST SHOWN BY THE
12Z NAM, AND NOW LATER RUNS OF THE 18Z GFS AND LATEST RUC ARE
PICKING UP ON THIS LAYER. IF THE MODELS CONTINUE TO BE CORRECT
THIS CLOUD SHIELD WILL REMAIN IN PLACE, WHILE EXPANDING TO THE
EAST THROUGH THE REST OF THE OVERNIGHT. I WAS TEMPTED TO DROP THE
FROST ADVISORY FOR STEUBEN COUNTY BASED ON THIS BUT WANTED TO WAIT
ANOTHER HOUR OR SO TO SEE IF CLEARING IN WESTERN NY MOVES EAST.
FOR NOW I PUSHED BACK THE TIMING OF BOTH FROST AND FOG FROM THE
BINGHAMTON AREA, WESTWARD, UNTIL CLOSER TO DAYBREAK ITSELF. WILL
REEVALUATE AND TRY TO MAKE A DECISION ON LOWERING ANY PRODUCTS BY
10 PM.
4 PM UPDATE... MAIN ISSUE OF THE NEAR TERM IS THE LIKELY
FIRST FROST FOR SOME PARTS OF THE AREA TONIGHT.
MOST CLOUD COVER WAS EATEN UP BY MIXING DOWN OF DRY AIR.
EXCEPTIONALLY DRY AIR EXISTS JUST ABOVE THE SUBSIDENCE
INVERSION...WITH 12Z BUFFALO SOUNDING DEWPOINTS REACHING AT LEAST
MINUS-45 CELSIUS IN THE 750-600MB LAYER AND MODEL SOUNDINGS IN OUR
AREA EVEN AROUND MINUS-60. PRECIPITABLE WATER VALUES ONLY AROUND A
QUARTER TO THIRD OF AN INCH. SURFACE DEWPOINTS ARE NOW IN UPPER
30S-LOW 40S FAHRENHEIT AND WILL PROBABLY DIP SOME MORE THE NEXT
HOUR OR TWO AS DIURNAL HEATING AND MIXING PEAKS.
SURFACE RIDGE EXTENDED UP THE ONTARIO PENINSULA EARLY THIS
MORNING...AND AWAY FROM THE LAKES TEMPERATURES THERE DIPPED IN
THE 30S BY DAWN WHERE IT STAYED CLEAR. IT SERVES AS A GOOD HINT OF
WHAT WILL OCCUR FOR PARTS OF OUR AREA...WITH THIS VERY DRY AIR
MASS...AND THE SURFACE HIGH PULLING DIRECTLY OVERHEAD TONIGHT.
THERE IS A BIG SPREAD IN GUIDANCE FOR LOWS TONIGHT...MAINLY A
PRODUCT OF DETAILS FOR WHERE SOME CLOUD COVER MAY REMAIN TRAPPED
UNDER THE SUBSIDENCE INVERSION. GUIDANCE IN GENERAL /ESPECIALLY
MAV/ HAS BEEN TOO COOL RECENTLY FOR NIGHTTIME LOWS...YET WHERE IT
STAYS CLEAR RADIATIONAL CONDITIONS WILL BE IDEAL TONIGHT.
DESPITE RH FIELDS IN SOME MODELS DEPICTING LAYER OF MOISTURE AROUND
900-850MB ADVECTING IN FROM THE WEST LATE TONIGHT...POSITION OF
THE SURFACE HIGH AND DRYNESS OF AIR MASS SUGGESTS THAT MOST CLOUDS
/EVEN JUST TO OUR WEST/ WILL ERADICATE WITH LOSS OF DIURNAL
HEATING. WHILE NOT GOING TO THE BOTTOM OF MODEL GUIDANCE...I DID
AT LEAST LEAN THAT DIRECTION BECAUSE OF EXPECTATION IN MAINLY
CLEAR CONDITIONS OVERNIGHT. I HAVE HOISTED FROST ADVISORY FOR
ONEIDA-MADISON-CHENANGO-OTSEGO-DELAWARE-SULLIVAN COUNTIES IN THE
EAST...AS WELL AS STEUBEN COUNTY IN THE WEST...WHERE CONFIDENCE IN
FROST-YIELDING TEMPERATURES IS HIGHEST. THIS ALSO HAPPENS TO BE
CLIMATE-WISE WHERE FROST TENDS TO OCCUR FIRST IN OUR REGION. THE
COLDEST VALLEYS IN EASTERN FRINGES OF OTSEGO-DELAWARE COUNTIES
COULD EVEN GET TO AROUND FREEZING...SUCH AS CHERRY VALLEY AND
ROXBURY.
FOR THE REMAINDER OF THE TWIN TIERS...PATCHY FROST IS STILL
POSSIBLE BUT NOT AS LIKELY NOR WITH AS MUCH COVERAGE COMPARED TO
THE ADVISORY COUNTIES. THE ADVISORY COULD BE AMENDED IN AREA
THOUGH BASED ON TRENDS. HOWEVER...VALLEY FOG IN THE MAIN STEM
RIVER VALLEYS OF THE TWIN TIERS MAY KEEP TEMPERATURES FROM
PLUMMETING TO FROST-PRONE READINGS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
415 PM UPDATE...
THE HIGH PRESSURE RESPONSIBLE FOR FROST CONCERNS TONIGHT...WILL
SHIFT OFF THE EAST COAST MONDAY. THIS WILL INITIATE A
SOUTHWESTERLY MODERATING FLOW...AND TEMPERATURES WARMING TO ABOUT
5-9 DEGREES HIGHER THAN TODAY /SUNDAY/. INITIAL SUNSHINE WILL
YIELD TO INCREASING CLOUDS FROM THE WEST BY LATE AFTERNOON.
MONDAY NIGHT/TUESDAY...UPPER LEVEL TROUGH AND ASSOCIATED COLD
FRONT WILL MOVE THROUGH THE REGION. MODELS ARE IN EXCELLENT
AGREEMENT WITH THIS FEATURE...AND HONED GRIDS IN ACCORDINGLY WITH
HIGH CONFIDENCE POPS /70-80 PCT RANGE/ SWEEPING THROUGH DURING THE
NIGHTTIME HOURS. NO INSTABILITY...SO ONLY SHOWERS
EXPECTED...GENERALLY A TENTH TO QUARTER INCH. POST-FRONTAL ON
TUESDAY...SHOWERS WILL QUICKLY WIND DOWN IN THE MORNING BUT CLOUDS
WILL BE A LITTLE MORE STUBBORN WITH HIGHS MAINLY LOW-MID 60S.
CLEARING LATE TUESDAY AFTERNOON-EVENING...LEADING TO ANOTHER
CHILLY NIGHT TUESDAY NIGHT. DEPENDING ON HOW DETAILS SHAKE
OUT...ESPECIALLY IN REGARDS TO HOW LONG IT TAKES TO CLEAR...JACK
FROST MAY AGAIN TRY TO VISIT A FEW PATCHY SPOTS BY DAWN WEDNESDAY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
2 AM UPDATE...
LITTLE CHANGE. THURSDAY AND FRIDAY COOL WITH HIGH PRESSURE. THE
WEEKEND WILL WARM AHEAD OF COLD FRONT THAT GOES THROUGH SUNDAY
NIGHT WITH SHOWERS.
PREVIOUS DISCUSSION...
FOLLOWED HPC GUIDANCE.
NO CHANGE TO THE LONG TERM PATTERN THROUGH THE NEXT SEVERAL DAYS.
A PERSISTENT UL TROF REMAINS FIXED OVER THE EASTERN U.S. WITH A
SURFACE HIGH KEEPING THE WEATHER FAIR AND COOL. THERE IS A
TEMPORARY RELAXATION TO THE FLOW PATTERN HEADING INTO NEXT WEEKEND,
AS THE UPPER ATMOSPHERE JET FLOW GOES ZONAL. THIS WILL ALLOW
TEMPERATURES TO REBOUND BACK TOWARD NORMAL (LOW 70S).
HOWEVER...LOOKING JUST BEYOND THE END OF THE EXTENDED PERIOD, A
STRONG FRONT MOVES THROUGH THE REGION EARLY NEXT WEEK AND THE UL
TROF RETURNS TO ENCOMPASS THE NORTHEAST ONCE AGAIN. AMAZINGLY,
THE MEAN EASTERN TROF HAS BEEN IN PLACE SINCE LAST NOVEMBER.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
130 AM UPDATE...
MAINLY VFR THROUGH 6Z TONIGHT.
LARGE AREA OF CLOUDS WITH 5K FT CIGS ACROSS NY. AVP ON THE EDGE OF
THESE CLOUDS BUT SHOULD HAVE CLOUDS MORE THAN NOT.
WITH THE CLOUDS VALLEY FOG WILL BE HARD TO COME BY SO WENT WITH
ONLY WITH A 8 TO 12Z TEMPO FOR MVFR VSBY FOG AT ELM.
THESE CLOUDS WILL MOVE OUT LATE MORNING BUT MID AND HIGH CLOUDS
WILL COME IN. 4K FT CLOUDS WILL COME BACK THIS EVE WITH A CHANCE
OF SHOWERS TOWARD 6Z.
WINDS LGT/VRB EARLY THIS MORNING BECOMING SW AT 5 KTS TODAY.
TONIGHT S AT 5 KT OR LIGHT AND VARIABLE.
OUTLOOK...
MON OVERNIGHT AND TUE MORNING...MVFR/IFR POSSIBLE IN SHOWERS.
TUE AFTN TO FRI...VFR EXCEPT FOR MORNING IFR FOG, ESPECIALLY AT ELM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ009-022-036-
037-045-046-057-062.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP/RRM
SHORT TERM...MDP
LONG TERM...DJP/TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1229 AM EDT MON SEP 15 2014
.SYNOPSIS...
HIGH PRESSURE WILL RESIDE OVER THE AREA THROUGH MONDAY PROVIDING
DRY WEATHER AND COOL TEMPERATURES. THE FIRST PATCHY FROST IS
POSSIBLE...MAINLY THE UPPER SUSQUEHANNA...WESTERN CATSKILLS...AND
TUG HILL PLATEAU REGIONS OF NEW YORK AS WELL AS STEUBEN COUNTY.
MONDAY NIGHT INTO EARLY TUESDAY MORNING A COLD FRONT WILL PASS
THROUGH THE AREA BRINGING A PERIOD OF SHOWERS. TEMPERATURES WILL
REMAIN ON THE COOL SIDE THE NEXT SEVERAL DAYS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1230 AM...CLOUD SHIELD OF 4-5K FT CIGS CONTINUE TO ADVANCE EAST
ACROSS FA AND ARE NOW MOVING INTO THE WESTERN CATSKILLS. SATELLITE
ANIMATION INDICATES THIS CLOUD COVER WILL REMAIN OVER THE REGION
FOR MUCH OF THE OVERNIGHT PERIOD AND WITH DEW POINTS IN THE LOWER
TO MIDDLE 40S ATTM WIDESPREAD FROST FORMATION LOOKS UNLIKELY IN
THE ADVISORY AREAS. SCATTERED FROST IS STILL POSSIBLE IN PARTS OF
THE WESTERN CATSKILLS AND WESTERN MOHAWK VALLEY. ADJUSTED TEMPS
AND CLOUD COVER AND WILL CONTINUE WITH FLAGS FOR NOW AND MOST
LIKELY CANCEL PARTS OR ALL OF ADVISORY AT 4 AM.
945 PM UPDATE...
CLOUD SHIELD ADVANCING THROUGH CENTRAL NY AS PER MODEL GUIDANCE.
FROST LIKELIHOOD LOOKING RATHER LOW FOR STEUBEN COUNTY, A BIT
HIGHER CHANCES ACROSS THE CATSKILLS. PER DISCUSSION BELOW I
THOUGHT ABOUT TAKING OUT STEUBEN COUNTY. WITH SOME BREAKS IN THE
CLOUDS TO THE WEST, WILL TAKE THE PATH OF LEAST REGRET AND LEAVE
ADVISORY IN PLACE. WITH THAT SAID THE FORECAST ITSELF IS MAINLY
37-40 IN THESE AREAS, WITH PATCHY FROST/FOG OVER ONLY A 2 HOUR
WINDOW. BOTTOM-LINE IS MOST OF THESE ARES WILL PROBABLY STAY FROST
FREE DUE TO CURRENT CLOUD COVER.
825 PM UPDATE...
MADE SOME MAJOR ADJUSTMENTS TO THE GRIDS TO INCREASE SKY COVER
THROUGH THE FINGER LAKES/WESTERN SOUTHERN TIER AND LOWER
PROBABILITY OF FROST/FOG HERE WHILE RAISING TEMPS SLIGHTLY. IT APPEARS
THE NAM MODEL WAS CORRECT AS CURRENT 11-3.9 MICRON SATELLITE ALONG
WITH OBS CONFIRM AN EXTENSIVE CLOUD SHIELD AROUND 5KFT OVER THE
WESTERN HALF OF THE CWA. THIS THIN LAYER WAS FIRST SHOWN BY THE
12Z NAM, AND NOW LATER RUNS OF THE 18Z GFS AND LATEST RUC ARE
PICKING UP ON THIS LAYER. IF THE MODELS CONTINUE TO BE CORRECT
THIS CLOUD SHIELD WILL REMAIN IN PLACE, WHILE EXPANDING TO THE
EAST THROUGH THE REST OF THE OVERNIGHT. I WAS TEMPTED TO DROP THE
FROST ADVISORY FOR STEUBEN COUNTY BASED ON THIS BUT WANTED TO WAIT
ANOTHER HOUR OR SO TO SEE IF CLEARING IN WESTERN NY MOVES EAST.
FOR NOW I PUSHED BACK THE TIMING OF BOTH FROST AND FOG FROM THE
BINGHAMTON AREA, WESTWARD, UNTIL CLOSER TO DAYBREAK ITSELF. WILL
REEVALUATE AND TRY TO MAKE A DECISION ON LOWERING ANY PRODUCTS BY
10 PM.
4 PM UPDATE... MAIN ISSUE OF THE NEAR TERM IS THE LIKELY
FIRST FROST FOR SOME PARTS OF THE AREA TONIGHT.
MOST CLOUD COVER WAS EATEN UP BY MIXING DOWN OF DRY AIR.
EXCEPTIONALLY DRY AIR EXISTS JUST ABOVE THE SUBSIDENCE
INVERSION...WITH 12Z BUFFALO SOUNDING DEWPOINTS REACHING AT LEAST
MINUS-45 CELSIUS IN THE 750-600MB LAYER AND MODEL SOUNDINGS IN OUR
AREA EVEN AROUND MINUS-60. PRECIPITABLE WATER VALUES ONLY AROUND A
QUARTER TO THIRD OF AN INCH. SURFACE DEWPOINTS ARE NOW IN UPPER
30S-LOW 40S FAHRENHEIT AND WILL PROBABLY DIP SOME MORE THE NEXT
HOUR OR TWO AS DIURNAL HEATING AND MIXING PEAKS.
SURFACE RIDGE EXTENDED UP THE ONTARIO PENINSULA EARLY THIS
MORNING...AND AWAY FROM THE LAKES TEMPERATURES THERE DIPPED IN
THE 30S BY DAWN WHERE IT STAYED CLEAR. IT SERVES AS A GOOD HINT OF
WHAT WILL OCCUR FOR PARTS OF OUR AREA...WITH THIS VERY DRY AIR
MASS...AND THE SURFACE HIGH PULLING DIRECTLY OVERHEAD TONIGHT.
THERE IS A BIG SPREAD IN GUIDANCE FOR LOWS TONIGHT...MAINLY A
PRODUCT OF DETAILS FOR WHERE SOME CLOUD COVER MAY REMAIN TRAPPED
UNDER THE SUBSIDENCE INVERSION. GUIDANCE IN GENERAL /ESPECIALLY
MAV/ HAS BEEN TOO COOL RECENTLY FOR NIGHTTIME LOWS...YET WHERE IT
STAYS CLEAR RADIATIONAL CONDITIONS WILL BE IDEAL TONIGHT.
DESPITE RH FIELDS IN SOME MODELS DEPICTING LAYER OF MOISTURE AROUND
900-850MB ADVECTING IN FROM THE WEST LATE TONIGHT...POSITION OF
THE SURFACE HIGH AND DRYNESS OF AIR MASS SUGGESTS THAT MOST CLOUDS
/EVEN JUST TO OUR WEST/ WILL ERADICATE WITH LOSS OF DIURNAL
HEATING. WHILE NOT GOING TO THE BOTTOM OF MODEL GUIDANCE...I DID
AT LEAST LEAN THAT DIRECTION BECAUSE OF EXPECTATION IN MAINLY
CLEAR CONDITIONS OVERNIGHT. I HAVE HOISTED FROST ADVISORY FOR
ONEIDA-MADISON-CHENANGO-OTSEGO-DELAWARE-SULLIVAN COUNTIES IN THE
EAST...AS WELL AS STEUBEN COUNTY IN THE WEST...WHERE CONFIDENCE IN
FROST-YIELDING TEMPERATURES IS HIGHEST. THIS ALSO HAPPENS TO BE
CLIMATE-WISE WHERE FROST TENDS TO OCCUR FIRST IN OUR REGION. THE
COLDEST VALLEYS IN EASTERN FRINGES OF OTSEGO-DELAWARE COUNTIES
COULD EVEN GET TO AROUND FREEZING...SUCH AS CHERRY VALLEY AND
ROXBURY.
FOR THE REMAINDER OF THE TWIN TIERS...PATCHY FROST IS STILL
POSSIBLE BUT NOT AS LIKELY NOR WITH AS MUCH COVERAGE COMPARED TO
THE ADVISORY COUNTIES. THE ADVISORY COULD BE AMENDED IN AREA
THOUGH BASED ON TRENDS. HOWEVER...VALLEY FOG IN THE MAIN STEM
RIVER VALLEYS OF THE TWIN TIERS MAY KEEP TEMPERATURES FROM
PLUMMETING TO FROST-PRONE READINGS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
415 PM UPDATE...
THE HIGH PRESSURE RESPONSIBLE FOR FROST CONCERNS TONIGHT...WILL
SHIFT OFF THE EAST COAST MONDAY. THIS WILL INITIATE A
SOUTHWESTERLY MODERATING FLOW...AND TEMPERATURES WARMING TO ABOUT
5-9 DEGREES HIGHER THAN TODAY /SUNDAY/. INITIAL SUNSHINE WILL
YIELD TO INCREASING CLOUDS FROM THE WEST BY LATE AFTERNOON.
MONDAY NIGHT/TUESDAY...UPPER LEVEL TROUGH AND ASSOCIATED COLD
FRONT WILL MOVE THROUGH THE REGION. MODELS ARE IN EXCELLENT
AGREEMENT WITH THIS FEATURE...AND HONED GRIDS IN ACCORDINGLY WITH
HIGH CONFIDENCE POPS /70-80 PCT RANGE/ SWEEPING THROUGH DURING THE
NIGHTTIME HOURS. NO INSTABILITY...SO ONLY SHOWERS
EXPECTED...GENERALLY A TENTH TO QUARTER INCH. POST-FRONTAL ON
TUESDAY...SHOWERS WILL QUICKLY WIND DOWN IN THE MORNING BUT CLOUDS
WILL BE A LITTLE MORE STUBBORN WITH HIGHS MAINLY LOW-MID 60S.
CLEARING LATE TUESDAY AFTERNOON-EVENING...LEADING TO ANOTHER
CHILLY NIGHT TUESDAY NIGHT. DEPENDING ON HOW DETAILS SHAKE
OUT...ESPECIALLY IN REGARDS TO HOW LONG IT TAKES TO CLEAR...JACK
FROST MAY AGAIN TRY TO VISIT A FEW PATCHY SPOTS BY DAWN WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FOLLOWED HPC GUIDANCE.
NO CHANGE TO THE LONG TERM PATTERN THROUGH THE NEXT SEVERAL DAYS.
A PERSISTENT UL TROF REMAINS FIXED OVER THE EASTERN U.S. WITH A
SURFACE HIGH KEEPING THE WEATHER FAIR AND COOL. THERE IS A
TEMPORARY RELAXATION TO THE FLOW PATTERN HEADING INTO NEXT WEEKEND,
AS THE UPPER ATMOSPHERE JET FLOW GOES ZONAL. THIS WILL ALLOW
TEMPERATURES TO REBOUND BACK TOWARD NORMAL (LOW 70S).
HOWEVER...LOOKING JUST BEYOND THE END OF THE EXTENDED PERIOD, A
STRONG FRONT MOVES THROUGH THE REGION EARLY NEXT WEEK AND THE UL
TROF RETURNS TO ENCOMPASS THE NORTHEAST ONCE AGAIN. AMAZINGLY,
THE MEAN EASTERN TROF HAS BEEN IN PLACE SINCE LAST NOVEMBER.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
00Z UPDATE...
EXPECT VFR CONDITIONS NEXT 24 HOURS AT TERMINALS WITH THE
EXCEPTION OF ELM. IF CLOUDS ARE ABLE TO DIMINISH IN THE NEXT
COUPLE OF HOURS ANOTHER ROUND OF VALLEY FOG IS EXPECTED TO
DEVELOP. MAJORITY OF MODEL GUIDANCE INDICATE MOISTURE WILL REMAIN
AROUND 5KFT THROUGH THE OVERNIGHT BUT FINDING THIS HARD TO BELIEVE
AND HAVE ESSENTIALLY GONE WITH THIN CIRRUS OVERHEAD THROUGH THE
NIGHT. AFTER 05Z AT ELM EXPECT MVFR VSBYS TO DEVELOP AS RAPID
COOLING COMMENCES. LIFR CONDITIONS EXPECTED BETWEEN 08Z AND 14Z
IF SKIES CAN CLEAR.
WINDS LGT/VRB OVERNIGHT THEN LIGHT OUT OF THE SW DURING THE DAY
MONDAY.
OUTLOOK...
MON NGT AND TUE MORNING...MVFR/IFR POSSIBLE IN SHOWERS ESPECIALLY
MONDAY OVERNIGHT.
TUE AFTN TO FRI...VFR EXCEPT FOR MORNING IFR FOG, ESPECIALLY AT ELM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ009-022-036-
037-045-046-057-062.
&&
$$
SYNOPSIS...MDP
NEAR TERM...HEDEN/MDP/RRM
SHORT TERM...MDP
LONG TERM...DJP
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
150 AM EDT MON SEP 15 2014
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL MAINTAIN A RATHER LONG STRETCH OF
COOL AND MAINLY DRY WEATHER. A WEAK FRONTAL SYSTEM WILL PASS
THROUGH MONDAY NIGHT AND EARLY TUESDAY MORNING...AND WILL BE THE
ONLY TIME WHEN RAIN IS POSSIBLE THROUGH THE END OF THE COMING
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
23Z RAP /AND LATEST REGIONAL SFC OBS/ INDICATES THAT A SECONDARY
CENTER OF SFC-925 MB HIGH PRESSURE WILL DRIFTING ACROSS SWRN AND
SCENT PENN OVERNIGHT. THIS WEATHER FEATURE WILL SUPPLY MAINLY
CLEAR SKIES AND L/V WIND ACROSS MUCH OF THE FCST AREA TONIGHT WITH
JUST SOME PATCHY STRATO CU OR RIBBONS OF THIN CIRRUS DRIFTING BY.
HOWEVER...THE LIGHT/WNW FLOW ACROSS THE NW AND NCENT MTNS
/COMBINED WITH LIMITED LLVL MOISTURE OFF THE UPSTREAM GLAKES AND
1-2 DEG C OF COOLING IN THE 925-850 MB LAYER/ WILL RESULT IN AREAS
OF BKN-OVC STRATO CU DRIFTING ESE FOR THE NEXT 3-5 HOURS.
THE HIGH WILL BE ACCOMPANIED BY BELOW NORMAL PWATS OF LESS THAN
0.75 OF AN INCH...LIGHT SFC-925 MB WINDS /GRADUALLY VEERING AROUND
TO THE N-E/...AND BELOW NORMAL TEMPS AT 850 MB.
EXPECTING THAT WE SEE A GRADUAL DECREASE IN THE STRATO CU FOR
SEVERAL HOURS EARLY MONDAY MORNING...THIS HIGH AND ITS ASSOCIATED
COOL AIRMASS WILL BRING CONDITIONS FAVORABLE FOR THE FIRST
WIDESPREAD FROST OF THE SEASON ACROSS NRN PENN...WHERE TEMPS OF
33-37 ARE LIKELY LATE TONIGHT THROUGH EARLY MONDAY. A FROST
ADVISORY REMAINS IN EFFECT ACROSS 4 OF OUR TYPICALLY COLDEST NRN
MTN COUNTIES - FROM 08-13Z MONDAY.
ELSEWHERE...PATCHY STRATO CU AND THIN STREAKS OF CIRRUS WILL HAVE
MINIMAL EFFECT ON TEMPS OVERNIGHT...WITH THE MERCURY FALLING
STEADILY TO CHILLY READINGS BY DAYBREAK MONDAY IN THE 30S
NORTH...TO MID 40S SOUTH.
LARGE AIR/WATER TEMP SPREAD...AND SFC DEWPOINTS BETWEEN 43-47F
WILL LEAD TO PATCHY DENSE RIVER VALLEY FOG...ESPECIALLY
THROUGHOUT THE DEEPER VALLEYS OF CENTRAL AND NRN PENN.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
ANY LOWER CLOUDS IN THE SC/SE IN THE MORNING SHOULD SLIDE TO THE
EAST AND DISSIPATE AS WE SAW WHAT HAPPENED SUN MORNING. GOOD SHORT
WAVE MOVING W-E OVER THE GREAT LAKES WILL PULL ENOUGH MOISTURE
INTO THE AREA TO CREATE A FEW TENTHS OF AN INCH OF RAIN MON NIGHT.
THE POPS SHOULD BE HIGH IN THE N AND NOT QUITE AS HIGH IN THE
SW...BUT SHOWERS ALSO LIKELY OR BETTER IN THE SE. THE FAST
MOVEMENT OF THE SYSTEM SHOULD PUSH ALL OF THE PRECIP TO THE EAST
OF THE AREA AT OR JUST AFTER SUNRISE ON TUESDAY MORNING.
MAXES MONDAY WILL GET PRETTY CLOSE TO NORMALS...AND THE CLOUDS AND
HIGHER DEWPOINTS SHOULD HOLD TEMPS UP IN THE 50S IN MOST PLACES
TUESDAY MORNING. THE COOLING EFFECTS OF THE RAIN AND EARLY PASSAGE
OF THE COLD FRONT WILL HELP THE NRN TIER DIP INTO THE 40S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
SHORTWAVE LIFTING INTO NEW ENGLAND BY TUE...BUT SCT LINGERING
LIGHT SHOWERS MAY PERSIST THROUGH MIDDAY BEFORE COOLER...DRIER
AIR FILTERS IN WITH INCREASING AMOUNTS OF SUNSHINE. NORTHWEST
FLOW AND SURFACE HIGH PRESSURE WILL BRING QUIET WEATHER FOR LATER
TUE THROUGH FRI...WITH JUST A WEAK FRONTAL BOUNDARY WASHING OUT
AS IT MOVES THROUGH MIDWEEK...FOLLOWED BY A REINFORCING SHOT OF
COOLER AIR. EXPECT CHILLY MORNINGS /POSS BOTTOMING OUT IN THE 30S
IN PORTIONS OF NORTHERN MOUNTAINS/ AND DAILY HIGHS RUNNING ABOUT
5F BELOW NORMAL.
GFS/ECMWF STILL DIFFER ON STRENGTH OF A SHORTWAVE TROUGH HEADED
OUR WAY FOR NEXT WEEKEND...BUT OVERALL TREND WILL BE FLOW TURNING
AROUND TO THE SOUTHWEST WITH A MODERATION OF TEMPS STARTING
SAT...AND RAIN CHANCES INCREASING FOR SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A WEAK SHORTWAVE ALOFT IS HELPING TO PRODUCE SOME STRATOCU OVER
THE NW AND CENTRAL MTNS. MVFR CONDITIONS ARE POSSIBLE FROM THE
STRATUS SLIDING IN FROM THE SOUTH AFTER MIDNIGHT. THE LAYER IS
CURRENTLY HUNG UP OVER NRN WV AND IS NOT ENTIRELY LIKELY TO MAKE
IT INTO CENTRAL PA. TRAPPED MOISTURE HAS ALLOWED FOR IFR CIGS AT
IPT...WHICH SHOULD VARY OVERNIGHT. EXPECT MVFR POSSIBLE THROUGH
THE LOWER SUSQ WHERE PATCHY FOG IS EXPECTED IN THE MORE- CLEAR
AREAS IN THE MORNING. IFR POSSIBLE IN THE DEEPER VALLEYS AROUND
SUNRISE.
A HEALTHY SHORT WAVE WILL MOVE W-E THRU THE GREAT LAKES AND DRAG
COLD FRONT THROUGH MONDAY NIGHT AND VERY EARLY TUESDAY. SHOWERS
ARE EXPECTED TO CREATE REDUCTIONS IN THE FLYING CONDITIONS MONDAY
NIGHT...BUT SHOULD BE OFF TO THE EAST BY 12Z TUES. LINGERING LOWER
CLOUDS AND SOME FOG WILL LAST INTO THE DAY ON TUESDAY BEFORE
CLEARING STARTS.
OUTLOOK...
TUE NIGHT-FRI...AM FOG POSS...OTHERWISE NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR PAZ005-006-010-
037.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
337 AM CDT MON SEP 15 2014
.SHORT TERM...
TODAY...FORECAST CONFIDENCE MEDIUM.
A STRONG...DIGGING MID LEVEL SHORTWAVE WILL BARREL ACROSS THE UPPER
MIDWEST TODAY. IT IS CURRENTLY OVER THE DAKOTAS AND WILL EXIT
SOUTHEAST WI AROUND 00Z THIS EVENING. IN RESPONSE...STRONG 925-850MB
FRONTOGENESIS WILL SLIDE EAST THROUGH CENTRAL AND SOUTHERN WI THIS
MORNING.
MID LEVEL FRONTOGENESIS IS RESPONSIBLE FOR THE WEAK RETURNS AND
LIGHT RAIN OVER CENTRAL WI EARLY THIS MORNING. SATURATION IN THE LOW
LEVELS HAS BEEN VERY SLOW OVERNIGHT...THUS NOT MUCH RAIN IS REACHING
THE GROUND. SHOWERS ARE CURRENTLY EXPANDING ACROSS SOUTHERN MN WITH
THE FGEN. THE HRRR AND HI-RES WRF MODELS HAVE A GOOD HANDLE ON THE
PRECIP EARLY THIS MORNING...SO I FOLLOWED THAT GUIDANCE CLOSELY FOR
TIMING. RAIN SHOULD ARRIVE IN MADISON AROUND 8 AM AND MILWAUKEE BY
10 AM.
GIVEN THE COMPACT NATURE OF THE SHORT WAVE AND THE SHARP SUBSIDENCE
EXPECTED IN ITS WAKE...THE RAIN WILL SHUT OFF VERY QUICKLY FROM WEST
TO EAST ON MONDAY...ENDING WEST OF MADISON BY LATE MORNING...AND IN
THE MILWAUKEE AREA BY ABOUT MID AFTERNOON. RAPID CLEARING SHOULD
THEN FOLLOW.
CLOUDS AND PRECIP WILL LEAD TO COOLER TEMPS TODAY...WITH HIGHS IN
THE MID TO UPPER 50S.
TONIGHT...FORECAST CONFIDENCE HIGH.
SURFACE HIGH PRESSURE WILL QUICKLY SETTLE INTO THE MIDWEST
OVERNIGHT. LIGHT WINDS...CLEAR SKIES AND RECENT RAIN OVER SOUTHERN
WI WILL ALLOW FOR QUICK COOLING AND SOME PATCHY LIGHT FOG. LOWS ARE
EXPECTED IN THE UPPER 30S INLAND...WARMER NEAR THE LAKESHORE.
.LONG TERM...
TUESDAY THROUGH THURSDAY...FORECAST CONFIDENCE HIGH.
SURFACE HIGH PRESSURE OVER THE AREA TUESDAY AND WEDNESDAY WILL
KEEP SKIES MOSTLY CLEAR WITH LIGHT WINDS AND GOOD RADIATIONAL
COOLING WHICH SHOULD PERMIT FOG FORMATION IN FAVORABLE VALLY AREAS
DURING EARLY MORNING HOURS. APPROACHING CANADIAN HIGH PRESSURE
SYSTEM WEDNESDAY NIGHT SHOULD PUSH A BACKDOOR COLD FRONT ACROSS
SOUTHEAST WISCONSIN AND LAKE MICHIGAN WED NIGHT AND CREATE WINDS
OVER THE WATERS THAT MAY REACH SMALL CRAFT ADVISORY CRITERIA. THE
COLD FRONT WILL BE SHALLOW WITH LITTLE LIFT OR MOISTURE TO WORK
WITH...THUS THE FORECAST REMAINS DRY.
THURSDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM.
THURSDAY NIGHT AND FRIDAY THE CANADIAN HIGH PRESSURE SYSTEM MOVES
WELL NORTHEAST OF THE GREAT LAKES...CREATING A SOUTHERLY FLOW ACROSS
WISCONSIN WHICH WILL BRING WARMER TEMPERATURES AND ADDITIONAL
MOISTURE TO THE AREA FOR THE WEEKEND. WEAK UPPER LEVEL DISTURBANCES
IN ZONAL FLOW ALOFT WILL COMBINE WITH SIGNIFICANT LOW LEVEL MOISTURE
TO BRING A CHANCE OF SHOWERS TO THE REGION FRIDAY AND FRIDAY NIGHT.
A DEEPER LOW WILL MOVE ACROSS LAKE SUPERIOR SATURDAY NIGHT AND BRING
AN ASSOCIATED COLD FRONT AND CHANCE OF RAIN TO WISCONSIN
SATURDAY...WITH CLEARING SATURDAY NIGHT AS THE FRONT PASSES.
&&
.AVIATION/12Z TAFS/...
A FAST MOVING AND POTENT MID LEVEL SHORT WAVE WILL TRACK THROUGH THE
UPPER MIDWEST THIS MORNING. LOOK FOR A PERIOD OF RAINFALL THAT WILL
LAST ABOUT 5-6 HOURS OVER SOUTHERN WI...THEN CLEAR OUT QUICKLY. CIGS
ARE EXPECTED TO DROP TO MVFR LEVELS WITHIN A FEW HOURS OF THE RAIN
STARTING...THEN CLEAR OUT WITHIN A FEW HOURS AFTER THE RAIN ENDS.
THE RAIN SHOULD BEGIN AT KMSN AROUND 12-13Z TODAY AND REACH
KMKE/KUES/KENW ABOUT 14-15Z. LOOK FOR IT TO END AT KMSN BY 19Z...
22Z AT KMKE/KUES/KENW. THE MVFR CIGS AND POSSIBLE MVFR VSBYS WILL
OCCUR DURING THE CORE OF THE RAINFALL.
CLEAR SKIES...RECENT RAIN AND LIGHT WINDS WITH HIGH PRESSURE
OVERNIGHT COULD LEAD TO SOME PATCHY MVFR FOG INLAND LATE TONIGHT
INTO MONDAY MORNING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MRC
TUESDAY THROUGH SUNDAY...SLB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1120 PM CDT SUN SEP 14 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 336 PM CDT SUN SEP 14 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE WEST COAST OF THE U.S. INTO BRITISH
CLIMB...WHILE DEEP TROUGHING ENCOMPASSED MUCH OF CENTRAL CANADA
INTO THE NORTHERN TIER OF THE CENTRAL U.S.. WITHIN THIS DEEP
TROUGH...THE TWO SHORTWAVE TROUGHS OF INTEREST WERE OVER LAKE
SUPERIOR AND IN SOUTHWEST SASKATCHEWAN. THE LAKE SUPERIOR
SHORTWAVE TROUGH WAS DRAGGING A COLD FRONT THROUGH THE FORECAST
AREA TODAY...BUT WITH LITTLE FAN FARE AS THE FRONT HAS BEEN
MOISTURE STARVED. 12Z SOUNDINGS FROM MPX AND ESPECIALLY GRB
REFLECT THE LACK OF MOISTURE. ADDITIONALLY...THE FRONT HAS BEEN
BASICALLY TURNING INTO A WIND SHIFT WITH 925MB TEMPS RUNNING
AROUND 10C ACROSS THE FORECAST AREA PER LATEST RAP ANALYSIS. THESE
TEMPS...BEING 2-4C WARMER THAN YESTERDAY...COMBINED WITH FULL SUN
HAS ALLOWED READINGS TO CLIMB INTO THE 60S. FARTHER TO THE
WEST...A SECONDARY COLD FRONT WAS DROPPING THROUGH NORTHWEST MN
WITH TEMPERATURES IN THE 50S AND SOME STRATUS IN ITS WAKE. AHEAD
OF THE FRONT...A STREAM OF MID CLOUDS WERE EXPANDING ACROSS
NORTHERN SOUTH DAKOTA INTO SOUTHERN MN...ASSOCIATED WITH MID-LEVEL
FRONTOGENESIS DOWNSTREAM OF THE SASKATCHEWAN SHORTWAVE. A 100 KT
JET STREAK FROM CENTRAL MN INTO UPPER MI AT 250MB IS ALSO
SUPPORTING THE MID CLOUDS.
MODELS ARE IN GOOD AGREEMENT TAKING THE SHORTWAVE OVER SOUTHWEST
SASKATCHEWAN THROUGH SOUTHWEST MN MONDAY MORNING AND ACROSS THE
FORECAST AREA MONDAY AFTERNOON. ADDITIONALLY...MODELS CONTINUE TO
SUGGEST THE SHORTWAVE WILL STRENGTHEN AS IT APPROACHES THE FORECAST
AREA...WHICH IN TURN INDUCES AN INCREASE IN THE UPPER JET STREAK
DOWNSTREAM AS WELL AS THE MID LEVEL FRONTOGENESIS. IN FACT...BY 12Z
MONDAY...THE SOUTHERN PORTION OF THE FORECAST AREA LIES IN A VERY
FAVORABLE DYNAMIC SITUATION...WITH A RIGHT ENTRANCE REGION OF THE
UPPER JET...DPVA AHEAD OF THE SHORTWAVE AND A FAIRLY STRONG COUPLET
OF MID LEVEL FRONTOGENESIS AND FRONTOLYSIS.
THE OVERALL BIG PROBLEM FOR PRECIPITATION IS MOISTURE. MOISTURE
TRANSPORT AHEAD OF THE SHORTWAVE WILL HELP PULL HIGHER PRECIPITABLE
WATER FROM THE SOUTHERN PLAINS TOWARDS THE REGION TONIGHT.
HOWEVER...CONVECTION SHOULD BREAK OUT ON THE NOSE OF THIS TRANSPORT
ACROSS NORTHERN MO...PUTTING A WALL UP ON THE MOISTURE RETURN.
STILL...PRECIPITABLE WATER SHOULD CLIMB UP TO ABOUT 1 INCH WHICH
WITH THE FORCING SHOULD BE ABLE TO SQUEEZE OUT SOME RAIN. DRY SUB-
CLOUD AIR MAY HINDER AMOUNTS TO SOME DEGREE.
TIMING WISE...SOME LIGHT RAIN COULD BREAK OUT AS EARLY AS THIS
EVENING...BUT THE BETTER CHANCE FOR RAIN COMES AFTER MIDNIGHT INTO
MONDAY MORNING. LOCATIONS AROUND AND SOUTH OF I-90 APPEAR TO HAVE
THE BEST CHANCE TO SEE RAIN. PRECIPITATION WILL DIMINISH RAPIDLY
MONDAY AFTERNOON AS THE SHORTWAVE MOVES THROUGH...WITH SKIES
CLEARING TOO.
REGARDING TEMPERATURES. THE SECONDARY COLD FRONT LOOKS TO PUSH
THROUGH THE FORECAST AREA TONIGHT...SENDING READINGS DOWN INTO THE
40S TO NEAR 50. IF THE CLOUDS STAYED IN ALL DAY MONDAY...HIGHS WOULD
STRUGGLE TO GET ABOVE THE MID 50S. HOWEVER...CONFIDENCE IS HIGH FOR
SUNSHINE IN THE AFTERNOON...WHICH SHOULD MUCH OF THE FORECAST AREA
CLIMB INTO THE UPPER 50S TO LOW 60S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 336 PM CDT SUN SEP 14 2014
FROM LATE MONDAY NIGHT AND TUESDAY MORNING...CANADIAN HIGH
PRESSURE WILL BUILD ACROSS THE AREA. THIS HIGH WILL PROVIDE CLEAR
SKIES ACROSS THE AREA. WITH THE CENTER OF THIS HIGH PASSING TO
SOUTHWEST...THERE WILL BE A SHALLOW LAYER OF LIGHT WINDS BELOW 950
MB. MEANWHILE THE WINDS WILL BE IN THE 10 TO 15 KNOT RANGE BETWEEN
950 AND 800 MB. THESE WINDS MAY HINDER THE DEVELOPMENT OF FOG AND
FROST. HOWEVER IS A STRONG SHALLOW NOCTURNAL INVERSION CAN
DEVELOPMENT CANNOT RULE OUT EITHER FROM OCCURRING...SO INCLUDED A
MENTION OF PATCHY VALLEY FOG IN THE MISSISSIPPI TRIBUTARIES AND IN
CENTRAL WISCONSIN. IN ADDITION WITH TEMPERATURES IN THE MID 30S
ACROSS PARTS OF WESTERN WISCONSIN... THERE MAY BE PATCHY FROST
TOO.
FROM LATE TUESDAY NIGHT AND WEDNESDAY MORNING...THERE WILL BE A
DEEPER LAYER OF LIGHT WINDS /UP TO 800 MB/. THE NAM CONTINUES TO
PRODUCE A VERY SHALLOW SATURATED LAYER. MEANWHILE THE GFS DOES NOT
PRODUCE THIS. WITH THE LIGHT WINDS AND COOL TEMPERATURES OVER THE
WARM RIVER WATERS...EXPECT THAT THERE WILL PATCHY TO AREAS OF FOG
IN THE RIVER VALLEYS AND OVER THE CRANBERRY BOGS OF CENTRAL
WISCONSIN. DUE TO THIS INCLUDED...IT IN THE FORECAST GRIDS.
ON WEDNESDAY...A BACK DOOR COLD FRONT MOVES THROUGH THE FORECAST
AREA. THE GEM PRODUCES SOME LIGHT PRECIPITATION ALONG AND NORTH OF
INTERSTATE 94. MEANWHILE THE ECMWF AND GFS KEEPS THE AREA DRY.
WITH THE BUFKIT SOUNDINGS SHOWING ONLY ABOUT 50 MB OF MOISTURE
BETWEEN 800 AND 850 MB...KEPT THE FORECAST DRY.
FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING...IT LOOKS LIKE
THERE WILL BE YET ANOTHER NIGHT FOR THE POTENTIAL OF VALLEY FOG AS
THE LIGHT WINDS ASCEND UP TO 700 MB. HOWEVER WITH THE WINDS
INCREASING INTO THE 10 TO 15 KNOTS LATE IN THE NIGHT...WE MAY END
UP WITH FOG DEVELOPING EARLIER IN THE NIGHT AND THEN BECOMING A
LAYER OF STRATUS AS THE LOW LEVEL WINDS INCREASE. DUE TO THIS
UNCERTAINTY...KEPT THE MENTION OF FOG OUT OF THE FORECAST GRIDS
FOR NOW.
FRIDAY INTO FRIDAY EVENING IS STARTING TO LOOK MORE INTERESTING AS
BOTH MODELS ARE STARTING TO CONVERGE ON A SOLUTION. A WARM FRONT
MOVES THROUGH THE AREA DURING THE MORNING AND THEN A COLD FRONT
MOVES INTO THE AREA ON FRIDAY EVENING. AS THE AREA MOVES INTO THE
WARM SECTOR OF THIS SYSTEM...THE ML CAPES CLIMB INTO THE 1500 TO
2500 J/KG RANGE. IN ADDITION...THE 0-6 KM SHEAR CLIMBS ABOVE 40
KNOTS. THIS COULD POTENTIALLY RESULT IN THE DEVELOPMENT OF SUPER
CELL THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS BEING THE
PRIMARY THREATS.
ON SATURDAY...THE 14.00Z MODELS SHOW A SURFACE LOW MOVING THROUGH
THE AREA. THIS KEEPS THE 0 TO 6 KM SHEAR ABOVE 45 KNOTS. WITH ML
CAPES IN THE 1000 TO 1500 J/KG...THERE COULD BE THE POTENTIAL FOR
SUPER CELL THUNDERSTORMS ACROSS NORTHEAST IOWA...AND SOUTHWEST AND
CENTRAL WISCONSIN. WITH 0-1 KM CAPES OVER 150 J/KG...LCL HEIGHTS
LESS THAN 2K FEET...AND 0-1 KM HELICITY OVER 100 M2/S2 ALONG THE
WARM FRONT WHICH IS LOCATED NEAR THE INTERSTATE 90 CORRIDOR IN
WISCONSIN...COULD NOT RULE THE POSSIBILITY OF ISOLATED TORNADOES
TO GO ALONG WITH THE THREAT FOR LARGE HAIL AND DAMAGING WINDS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1120 PM CDT SUN SEP 14 2014
NARROW BAND OF SHOWERS CONTINUES ACROSS SOUTHERN MN/WESTERN WI...IN
A REGION OF ELEVATED FRONTOGENETIC FORCING. PCPN IS FALLING OUT OF
MID LEVEL CLOUDS WITH NO VSBY RESTRICTIONS. AS AN UPPER LEVEL
SHORTWAVE STARTS TO PUSH IN FROM THE NORTHERN PLAINS OVERNIGHT...THE
PCPN WILL BECOME MORE WIDESPREAD AND START TO SINK SOUTH. LOW LEVEL
RH INCREASES...PER BUFKIT SOUNDINGS...AND CONDITIONS LOOK FAVORABLE
FOR A DROP INTO MVFR CIGS FOR A FEW HOURS.
MESO MODELS TAKE THIS SYSTEM ACROSS THE REGION DURING THE
AFTERNOON...EXITING BY EARLY EVENING. PCPN SHOULD FOLLOW SUIT...BUT
A BIT EARLIER...MOVING EAST/SOUTHEAST OF THE TAF SITES BETWEEN 15-
18Z. SUBSIDENCE POST THE SHORTWAVE...ALONG WITH A SFC HIGH
INFLUENCING FROM THE CENTRAL PLAINS...SHOULD CLEAR SKIES LATER MON
AFTERNOON.
SEE A POTENTIAL FOR RIVER VALLEY FOG AT KLSE FOR TUE MORNING. WITH
EARLY MORNING PCPN...CLEARING SKIES...AND THEN A LIGHT WIND FIELD
MONDAY NIGHT...THE SETUP LOOKS GOOD. BIGGEST QUESTION MARK AT THIS
TIME WOULD APPEAR TO BE THE DEPTH OF THE LIGHT WIND LAYER. 00Z NAM
BUFKIT SOUNDINGS ARE SHALLOW FOR THE EVENING HOURS...BUT QUICKLY
DEEPENS OVERNIGHT. COULD BE ENOUGH FOR SUB 1SM VSBY FOG - PERHAPS
1/4SM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1050 AM EDT MON SEP 15 2014
.SYNOPSIS...
ISSUED AT 1046 AM EDT MON SEP 15 2014
A COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA TODAY...BRINGING
RAIN SHOWERS AND ISOLATED THUNDERSTORMS TO THE REGION. DRY
CONDITIONS WILL RETURN LATER THIS EVENING BEHIND THE FRONT...WITH
A REINFORCING PUSH OF COOL AIR RESULTING IN CONTINUED BELOW NORMAL
TEMPERATURES THROUGH MID WEEK. HIGH TEMEPRATURES THIS AFTERNOON
WILL REACH INTO THE 60S. LOW TEMPERATURES TONIGHT WILL RANGE FROM
THE MID 40S TO AROUND 50.
&&
.UPDATE...
ISSUED AT 920 AM EDT MON SEP 15 2014
VERY STEEP MIDLEVEL LAPSE RATES...OVER 8 C/KM ON LATEST SPC/RAP
MESOANALYSIS...HAVE SUPPORTED A FEW ELEVATED THUNDERSTORMS AS
INITIAL SATURATION OCCURS. RAP FORECAST SOUNDINGS AND MUCAPE
FIELDS INDICATE THIS INSTABILITY WILL DECREASE THROUGH THE DAY BUT
SUGGEST LAPSE RATES WILL REMAIN JUST STEEP ENOUGH IN OUR SOUTHERN
COUNTIES TO ALLOW FOR A FEW ISOLATED THUNDERSTORMS ALONG ELEVATED
FRONTAL ZONE THROUGH THE EARLY AFTERNOON. CURRENTLY NUMEROUS
THUNDERSTORMS IN SOUTHERN IOWA AND WESTERN ILLINOIS. THIS ACTIVITY
IS ENTRENCHED IN THE BETTER THETA-E PLUME BUT SUSPECT A FEW
THUNDERSTORMS WILL CONTINUE TO CLIP OUR SOUTHWEST COUNTIES AT
LEAST. HAVE UPDATED THE FORECAST ACCORDINGLY. OTHERWISE FORECAST
REMAINS IN GOOD SHAPE WITH JUST A FEW CHANGES TO INHERITED POPS TO
REFLECT LATEST RADAR TRENDS AND INCREASING CONFIDENCE THAT MOST
AREAS WILL SEE AT LEAST A HUNDREDTH TODAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM EDT MON SEP 15 2014
THE NEXT UPPER LEVEL SHORT WAVE OF INTEREST IS WELL PRONOUNCED ON
WATER VAPOR IMAGERY THIS MORNING ACROSS THE DAKOTAS. ALREADY HAVE
NOTED SOME VERY WEAK ELEVATED ECHOES UPSTREAM ACROSS
CENTRAL/NORTHERN ILLINOIS WHERE BACKING OF LOW LEVEL WINDS HAS
ALLOWED FOR AN INCREASE AN ISENTROPIC LIFT. AT LEAST OVER THE NEXT
SEVERAL HOURS...SHOWER POTENTIAL SEEMS SOMEWHAT MINIMAL DUE TO
HIGHLY ELEVATED NATURE OF THIS FORCING AND INITIALLY QUITE DRY LOW
LEVELS. SOUTHWESTERLY LOW LEVEL FLOW WILL RAMP UP SOMEWHAT IN
ADVANCE OF THIS WAVE ALLOWING BROAD WEAK LOW LEVEL THETAE RIDGING
ACROSS THE MID MISSISSIPPI RIVER VALLEY TO SHIFT INTO THE OHIO
VALLEY/SOUTHERN GREAT LAKES. LOW/MID LEVEL FRONTOGENESIS WILL ALSO
BE ON THE UPSWING IN ADVANCE OF THIS WAVE...ESPECIALLY DURING THE
MID TO LATE AFTERNOON HOURS. LOCAL AREA WILL ALSO BECOME
INCREASINGLY FAVORED IN RIGHT ENTRANCE REGION OF GREAT LAKES UPPER
JET STREAK. GIVEN FAIRLY STRENGTH OF UPPER WAVE...MID/UPPER LEVEL
FRONTOGENESIS...AND STRENGTHENING ISENTROPIC UPGLIDE...HAVE STAYED
THE COURSE WITH HIGH END LIKELY POPS. MAY EVENTUALLY NEED TO
CONSIDER NUDGING INTO CATEGORICAL POP RANGE FOR PORTIONS OF THE AREA
HOWEVER AS STRONGER ISENTROPIC UPGLIDE/FRONTAL FORCING BECOME
ESTABLISHED LATER THIS AFTERNOON/EARLY EVENING. MAIN TWEAK TO
FORECAST WAS TO PUSH TIMING OF HIGHER POPS BACK JUST A FEW HOURS
INTO THE LATE AFTERNOON HOURS AS APPROACHING FRONTAL FORCING SHOULD
ALLOW PRECIP TO CONTINUE.
A FEW THUNDERSTORMS HAVE DEVELOPED ACROSS SOUTHERN IOWA THIS MORNING
IN ZONE OF STRONGER ISENTROPIC LIFT/LOW LEVEL MASS CONVERGENCE.
CURRENT FORECAST THINKING IS THAT BETTER THUNDER POTENTIAL WILL
REMAIN SOUTHWEST OF LOCAL AREA IN RICHER LOW LEVEL THETAE AIRMASS.
WHILE CANNOT COMPLETELY RULE OUT AN ISOLATED THUNDERSTORM
PARTICULARLY ACROSS THE SOUTHWEST...FEEL PROSPECTS ARE BELOW
MENTIONABLE LEVELS AT THIS TIME.
AXIS OF MORE PRONOUNCED MID LEVEL FRONTO FORCING TO LINGER ACROSS
THE CENTRAL/EASTERN AREAS EARLY THIS EVENING WHERE HAVE CARRIED
LIKELY POPS...WITH CONDITIONS DRYING OUT FROM WEST TO EAST. SKIES
SHOULD CLEAR OR PARTIALLY CLEAR TONIGHT AS LOW LEVEL TROUGH AXIS
CLEARS AREA...ALTHOUGH AS HAS BEEN THE CASE OVER THE PAST SEVERAL
DAYS...PERSISTENT LOW LEVEL INVERSION GIVES SOME HESITATION FOR MORE
LONGEVITY OF STRATOCU THAN CURRENTLY FORECASTED. LOWS SHOULD DROP
INTO THE MID 40S TONIGHT...BUT PROBABLY MORE INTO THE UPPER 40S TO
AROUND 50 RANGE WHERE STRATUS PERSISTS LONGER. SOME LAKE EFFECT LOW
CLOUDINESS MAY ALSO PROVIDE WARMER CONDITIONS NEAR THE NW INDIANA
LAKESHORE AREAS...BUT LAKE INDUCED INSTABILITY DEPTHS APPEAR TO BE
TOO SHALLOW FOR ANY PRECIP INCLUSION AT THIS TIME.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 445 AM EDT MON SEP 15 2014
TRANQUIL WEATHER IS EXPECTED FOR TUESDAY INTO SATURDAY WITH
GRADUALLY MODERATING TEMPERATURES AS THE FLOW BECOMES MORE HIGH
ZONAL AND AS THE AIRMASS OVER THE AREA MODIFIES. AT THE START OF THE
PERIOD...THE SHORT WAVE WILL HAVE MOVED EAST OF THE AREA BY TUESDAY
MORNING...WITH DECREASING CLOUDS EXPECTED DURING THE DAY AS
SUBSIDENCE BEHIND THE TROF INCREASES. FAVORABLE NOCTURNAL
RADIATIONAL COOLING CONDITIONS ARE EXPECTED TUESDAY NIGHT WITH LOWS
DROPPING WELL BELOW 50 DEGREES. COULD BE SOME PATCHY FROST IN
LOCALLY COLD SPOTS...BUT OTHERWISE...FROST IS NOT EXPECTED AND HAVE
NOT MENTIONED ANY FROST IN THE GRIDS/FORECAST. THE GFS HAS BEEN
REASONABLY CONSISTENT WITH THE WARM UP THIS WEEK...AND THE GFS/MEX
MEAN ENSEMBLE MOS TEMPERATURES APPEAR ON TRACK. FOR THIS COMING
WEEKEND...THE GFS AND ECMWF HAVE COME INTO A LITTLE BETTER AGREEMENT
ON TIMING OF THE NEXT SYSTEM...WITH AN UPPER LEVEL SYSTEM AND
ASSOCIATED COLD FRONT MOVING ACROSS THE AREA BY LATE IN THE WEEKEND.
FOR NOW...KEPT A CHANCE FOR SHOWERS SATURDAY THROUGH SUNDAY. THUNDER
MAY NEED TO BE ADDED AT SOME POINT...BUT FOR NOW KEPT THUNDER OUT
GIVEN CAPE VALUES VERY SMALL PER GFS/BUFKIT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 653 AM EDT MON SEP 15 2014
LOW LEVEL WARM ADVECTION WILL CONTINUE TO INCREASE THROUGH THE
MORNING IN ADVANCE OF NEXT NORTHERN PLAINS UPPER TROUGH
APPROACHING THE REGION. ENOUGH ELEVATED INSTABILITY MAY EXIST FOR
AN ISOLATED THUNDERSTORM AT KSBN THROUGH 14Z...BUT OTHERWISE
POTENTIAL OF THUNDER APPEARS TO BE QUITE LOW FOR TERMINALS...WITH
BETTER INSTABILITY SETTING UP SOUTH/SOUTHWEST. COVERAGE OF RAIN
SHOWERS WILL INCREASE LATE MORNING INTO THIS AFTERNOON AS WARM
ADVECTION FORCING INCREASES. LIKELIHOOD OF RAIN WILL CONTINUE
THROUGH MOST OF AFTERNOON AS UPPER TROUGH/MID LEVEL FRONTOGENESIS
APPROACH FROM THE WEST...WITH CONDITIONS DRYING FROM WEST TO EAST
THIS EVENING. HAVE MAINTAINED TREND OF PREVIOUS TAF TO LOWER END
MVFR CIGS LATE THIS AFTERNOON/EARLY EVENING WITH THE POSSIBILITY
OF SOME SHORT LIVED IFR CONDITIONS. SOME STRATUS OR PATCHY FOG MAY
DEVELOP BEHIND SFC TROUGH TONIGHT GIVEN LINGERING LOW LEVEL
MOISTURE AND LOW LEVEL INVERSION...BUT WILL MAINTAIN VFR
CONDITIONS AT THIS TIME FOR THE LATTER PORTIONS OF THE FORECAST PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...AGD
SYNOPSIS...MCD
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
920 AM EDT MON SEP 15 2014
.SYNOPSIS...
ISSUED AT 445 AM EDT MON SEP 15 2014
CLOUDS WILL BE ON THE INCREASE TODAY AS AN UPPER LEVEL DISTURBANCE
ACROSS THE NORTHERN PLAINS APPROACHES. THIS DISTURBANCE WILL BRING
THE LIKELIHOOD OF RAIN SHOWERS LATER TODAY INTO THIS EVENING. DRY
CONDITIONS WILL RETURN LATER THIS EVENING BEHIND THIS SYSTEM...WITH
A REINFORCING PUSH OF COOL AIR RESULTING IN CONTINUED BELOW NORMAL
TEMPERATURES THROUGH MID WEEK. HIGH TEMPERATURES THIS AFTERNOON WILL
REACH INTO THE 60S...EXCEPT LOWER 70S ACROSS CENTRAL INDIANA INTO
CENTRAL OHIO. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE MID 40S
TO AROUND 50.
&&
.UPDATE...
ISSUED AT 920 AM EDT MON SEP 15 2014
VERY STEEP MIDLEVEL LAPSE RATES...OVER 8 C/KM ON LATEST SPC/RAP
MESOANALYSIS...HAVE SUPPORTED A FEW ELEVATED THUNDERSTORMS AS
INITIAL SATURATION OCCURS. RAP FORECAST SOUNDINGS AND MUCAPE
FIELDS INDICATE THIS INSTABILITY WILL DECREASE THROUGH THE DAY BUT
SUGGEST LAPSE RATES WILL REMAIN JUST STEEP ENOUGH IN OUR SOUTHERN
COUNTIES TO ALLOW FOR A FEW ISOLATED THUNDERSTORMS ALONG ELEVATED
FRONTAL ZONE THROUGH THE EARLY AFTERNOON. CURRENTLY NUMEROUS
THUNDERSTORMS IN SOUTHERN IOWA AND WESTERN ILLINOIS. THIS ACTIVITY
IS ENTRENCHED IN THE BETTER THETA-E PLUME BUT SUSPECT A FEW
THUNDERSTORMS WILL CONTINUE TO CLIP OUR SOUTHWEST COUNTIES AT
LEAST. HAVE UPDATED THE FORECAST ACCORDINGLY. OTHERWISE FORECAST
REMAINS IN GOOD SHAPE WITH JUST A FEW CHANGES TO INHERITED POPS TO
REFLECT LATEST RADAR TRENDS AND INCREASING CONFIDENCE THAT MOST
AREAS WILL SEE AT LEAST A HUNDREDTH TODAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM EDT MON SEP 15 2014
THE NEXT UPPER LEVEL SHORT WAVE OF INTEREST IS WELL PRONOUNCED ON
WATER VAPOR IMAGERY THIS MORNING ACROSS THE DAKOTAS. ALREADY HAVE
NOTED SOME VERY WEAK ELEVATED ECHOES UPSTREAM ACROSS
CENTRAL/NORTHERN ILLINOIS WHERE BACKING OF LOW LEVEL WINDS HAS
ALLOWED FOR AN INCREASE AN ISENTROPIC LIFT. AT LEAST OVER THE NEXT
SEVERAL HOURS...SHOWER POTENTIAL SEEMS SOMEWHAT MINIMAL DUE TO
HIGHLY ELEVATED NATURE OF THIS FORCING AND INITIALLY QUITE DRY LOW
LEVELS. SOUTHWESTERLY LOW LEVEL FLOW WILL RAMP UP SOMEWHAT IN
ADVANCE OF THIS WAVE ALLOWING BROAD WEAK LOW LEVEL THETAE RIDGING
ACROSS THE MID MISSISSIPPI RIVER VALLEY TO SHIFT INTO THE OHIO
VALLEY/SOUTHERN GREAT LAKES. LOW/MID LEVEL FRONTOGENESIS WILL ALSO
BE ON THE UPSWING IN ADVANCE OF THIS WAVE...ESPECIALLY DURING THE
MID TO LATE AFTERNOON HOURS. LOCAL AREA WILL ALSO BECOME
INCREASINGLY FAVORED IN RIGHT ENTRANCE REGION OF GREAT LAKES UPPER
JET STREAK. GIVEN FAIRLY STRENGTH OF UPPER WAVE...MID/UPPER LEVEL
FRONTOGENESIS...AND STRENGTHENING ISENTROPIC UPGLIDE...HAVE STAYED
THE COURSE WITH HIGH END LIKELY POPS. MAY EVENTUALLY NEED TO
CONSIDER NUDGING INTO CATEGORICAL POP RANGE FOR PORTIONS OF THE AREA
HOWEVER AS STRONGER ISENTROPIC UPGLIDE/FRONTAL FORCING BECOME
ESTABLISHED LATER THIS AFTERNOON/EARLY EVENING. MAIN TWEAK TO
FORECAST WAS TO PUSH TIMING OF HIGHER POPS BACK JUST A FEW HOURS
INTO THE LATE AFTERNOON HOURS AS APPROACHING FRONTAL FORCING SHOULD
ALLOW PRECIP TO CONTINUE.
A FEW THUNDERSTORMS HAVE DEVELOPED ACROSS SOUTHERN IOWA THIS MORNING
IN ZONE OF STRONGER ISENTROPIC LIFT/LOW LEVEL MASS CONVERGENCE.
CURRENT FORECAST THINKING IS THAT BETTER THUNDER POTENTIAL WILL
REMAIN SOUTHWEST OF LOCAL AREA IN RICHER LOW LEVEL THETAE AIRMASS.
WHILE CANNOT COMPLETELY RULE OUT AN ISOLATED THUNDERSTORM
PARTICULARLY ACROSS THE SOUTHWEST...FEEL PROSPECTS ARE BELOW
MENTIONABLE LEVELS AT THIS TIME.
AXIS OF MORE PRONOUNCED MID LEVEL FRONTO FORCING TO LINGER ACROSS
THE CENTRAL/EASTERN AREAS EARLY THIS EVENING WHERE HAVE CARRIED
LIKELY POPS...WITH CONDITIONS DRYING OUT FROM WEST TO EAST. SKIES
SHOULD CLEAR OR PARTIALLY CLEAR TONIGHT AS LOW LEVEL TROUGH AXIS
CLEARS AREA...ALTHOUGH AS HAS BEEN THE CASE OVER THE PAST SEVERAL
DAYS...PERSISTENT LOW LEVEL INVERSION GIVES SOME HESITATION FOR MORE
LONGEVITY OF STRATOCU THAN CURRENTLY FORECASTED. LOWS SHOULD DROP
INTO THE MID 40S TONIGHT...BUT PROBABLY MORE INTO THE UPPER 40S TO
AROUND 50 RANGE WHERE STRATUS PERSISTS LONGER. SOME LAKE EFFECT LOW
CLOUDINESS MAY ALSO PROVIDE WARMER CONDITIONS NEAR THE NW INDIANA
LAKESHORE AREAS...BUT LAKE INDUCED INSTABILITY DEPTHS APPEAR TO BE
TOO SHALLOW FOR ANY PRECIP INCLUSION AT THIS TIME.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 445 AM EDT MON SEP 15 2014
TRANQUIL WEATHER IS EXPECTED FOR TUESDAY INTO SATURDAY WITH
GRADUALLY MODERATING TEMPERATURES AS THE FLOW BECOMES MORE HIGH
ZONAL AND AS THE AIRMASS OVER THE AREA MODIFIES. AT THE START OF THE
PERIOD...THE SHORT WAVE WILL HAVE MOVED EAST OF THE AREA BY TUESDAY
MORNING...WITH DECREASING CLOUDS EXPECTED DURING THE DAY AS
SUBSIDENCE BEHIND THE TROF INCREASES. FAVORABLE NOCTURNAL
RADIATIONAL COOLING CONDITIONS ARE EXPECTED TUESDAY NIGHT WITH LOWS
DROPPING WELL BELOW 50 DEGREES. COULD BE SOME PATCHY FROST IN
LOCALLY COLD SPOTS...BUT OTHERWISE...FROST IS NOT EXPECTED AND HAVE
NOT MENTIONED ANY FROST IN THE GRIDS/FORECAST. THE GFS HAS BEEN
REASONABLY CONSISTENT WITH THE WARM UP THIS WEEK...AND THE GFS/MEX
MEAN ENSEMBLE MOS TEMPERATURES APPEAR ON TRACK. FOR THIS COMING
WEEKEND...THE GFS AND ECMWF HAVE COME INTO A LITTLE BETTER AGREEMENT
ON TIMING OF THE NEXT SYSTEM...WITH AN UPPER LEVEL SYSTEM AND
ASSOCIATED COLD FRONT MOVING ACROSS THE AREA BY LATE IN THE WEEKEND.
FOR NOW...KEPT A CHANCE FOR SHOWERS SATURDAY THROUGH SUNDAY. THUNDER
MAY NEED TO BE ADDED AT SOME POINT...BUT FOR NOW KEPT THUNDER OUT
GIVEN CAPE VALUES VERY SMALL PER GFS/BUFKIT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 653 AM EDT MON SEP 15 2014
LOW LEVEL WARM ADVECTION WILL CONTINUE TO INCREASE THROUGH THE
MORNING IN ADVANCE OF NEXT NORTHERN PLAINS UPPER TROUGH
APPROACHING THE REGION. ENOUGH ELEVATED INSTABILITY MAY EXIST FOR
AN ISOLATED THUNDERSTORM AT KSBN THROUGH 14Z...BUT OTHERWISE
POTENTIAL OF THUNDER APPEARS TO BE QUITE LOW FOR TERMINALS...WITH
BETTER INSTABILITY SETTING UP SOUTH/SOUTHWEST. COVERAGE OF RAIN
SHOWERS WILL INCREASE LATE MORNING INTO THIS AFTERNOON AS WARM
ADVECTION FORCING INCREASES. LIKELIHOOD OF RAIN WILL CONTINUE
THROUGH MOST OF AFTERNOON AS UPPER TROUGH/MID LEVEL FRONTOGENESIS
APPROACH FROM THE WEST...WITH CONDITIONS DRYING FROM WEST TO EAST
THIS EVENING. HAVE MAINTAINED TREND OF PREVIOUS TAF TO LOWER END
MVFR CIGS LATE THIS AFTERNOON/EARLY EVENING WITH THE POSSIBILITY
OF SOME SHORT LIVED IFR CONDITIONS. SOME STRATUS OR PATCHY FOG MAY
DEVELOP BEHIND SFC TROUGH TONIGHT GIVEN LINGERING LOW LEVEL
MOISTURE AND LOW LEVEL INVERSION...BUT WILL MAINTAIN VFR
CONDITIONS AT THIS TIME FOR THE LATTER PORTIONS OF THE FORECAST PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...AGD
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
917 AM CDT MON SEP 15 2014
.UPDATE...
ISSUED AT 909 AM CDT MON SEP 15 2014
MINOR CHANGES TO THE DAYTIME FORECAST TO REMOVE THUNDER FROM THE
SOUTH FOR THE REST OF THE DAY AND UPDATE PRECIP TRENDS. SHOWER
ACTIVITY IN THE SOUTHERN BAND HAS WEAKENED AND MOVED OFF INTO FAR
SE IA AND NORTHERN MO WITH A FEW RESIDUAL CELLS CONTINUING IN FAR
SW IA. AREA OF RAIN SHOWERS OVER NORTH CENTRAL IOWA SHOULD SWING
THROUGH THE NORTHERN TWO THIRDS OF THE CWA WITH THE COLD
FRONT/UPPER LEVEL WAVE LATER THIS MORNING. HIGHS WERE NOT UPDATED
BUT WILL CONTINUE TO BE MONITORED FOR ADJUSTMENTS...ESPECIALLY
WITH LOWERING FORECAST HIGHS IN THE NORTH.
&&
.SHORT TERM /TODAY/...
ISSUED AT 323 AM CDT MON SEP 15 2014
PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS TODAY. MEAN
TROUGH CONTINUES TO ADVANCE THROUGH THE NRN CONUS THIS MORNING.
WEAK KINEMATICALLY FORCED PRECIP CONTINUES OVER SD/MN/WI JUST
BRUSHING NRN IA. THIS IS DRIVEN BY DPVA AHEAD OF POTENT DAKOTAS
SHORT WAVE/PV ANOMALY AND RIGHT ENTRANCE REGION OF GREAT LAKES JET
SEGMENT. FARTHER SOUTH WARM/THETA-E ADVECTION HAS STRENGTHENED IN
RESPONSE ALONG MO VALLEY BAROCLINIC AND FRONTOGENESIS ZONE.
INSTABILITY HAS INCREASED IN THIS RETURN FLOW WITH UNCAPPED 500
J/KG MUCAPES ENTERING SWRN IA...ROOTED 1-1.5KM. EFFECTIVE SHEAR IS
PUSHING 50KTS IN THIS AREA AND RESULTED IN A FEW SUB SEVERE HAIL
REPORTS OVER FAR ERN NE.
THIS THERMODYNAMIC FORCING AND INSTABILITY WILL BE LIMITED IN
TIME HOWEVER. RAP 305K ISENT SURFACE SHOWS THIS LIFT PUSHING
SOUTHWARD OUT OF THE STATE WITH TIME AS LONG WAVE TROUGH
APPROACHES. THIS WILL BRING MUCH OF THE STATE UNDER THE INFLUENCE
OF KINEMATIC RATHER THAN THERMODYNAMIC FORCING WHICH SHOULD SPREAD
INTO IA WITH TIME. MOISTURE WAS LIMITED INITIALLY BUT EXPECT
FORCING TO SOON INDUCE SATURATION AND MORE WIDESPREAD PRECIP. THE
PRONOUNCED SUBSIDENCE/LIFT COUPLET WILL BE EXITING ERN SECTIONS BY
18Z HOWEVER SO MUCH OF THE FORECAST AREA SHOULD BE DRY BY EARLY
AFTERNOON.
08Z SURFACE ANALYSIS APPEARS TO SHOW TWO FRONTS...ONE FROM KS/MO
TO BETWEEN CRESTON AND DES MOINES...WITH ANOTHER FROM THE AMES
AREA TO JUST SOUTH OF WATERLOO. THESE SHOULD QUICKLY PHASE AND
EXIT THE AREA BY 18Z PRODUCING PROBLEMATIC AND IN PLACES NON-
DIURNAL TEMP TRENDS. READINGS SHOULD REBOUND LITTLE SE WITH SYSTEM
EFFECTS LINGERING LONGER. HOWEVER FAR NW SHOULD SEE THE PRECIP END
EARLIER WITH CLEARING AND MORE POTENTIAL FOR MIXING AND REBOUND.
THIS RESULTS IN FAIRLY HOMOGENEOUS AND LOW CONFIDENCE TEMP
FORECAST IN THE LOWER 60S NEAR MOS GUIDANCE BLEND.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 323 AM CDT MON SEP 15 2014
FROM TONIGHT THROUGH THURSDAY THE WEATHER WILL BE DRY AND QUIET
WITH A SLOW WARMING TREND. A SURFACE HIGH PRESSURE AREA WILL BE
DRAPED ACROSS IOWA OVERNIGHT ALLOWING TEMPERATURES TO FALL INTO
THE UPPER 30S IN SOME AREAS...HOWEVER NO SIGNIFICANT FROST EFFECTS
ARE ANTICIPATED AS TEMPERATURES SHOULD NOT DROP TO THE LEVELS SEEN
ON SATURDAY MORNING. PATCHY TO POSSIBLY WIDESPREAD FOG DEVELOPMENT
IS ANTICIPATED PARTICULARLY IN AREAS WHERE RAIN FALLS THIS
MORNING. ON TUESDAY NIGHT AND WEDNESDAY A ZONE OF WARM AIR
ADVECTION JUST TO OUR SOUTHWEST SHOULD GENERATE SOME SHOWERS AND
STORMS FROM EASTERN NEBRASKA DOWN INTO MISSOURI...BUT THIS
ACTIVITY IS EXPECTED TO MISS OUR FORECAST AREA WITH JUST SOME
SLIGHT POPS MAINTAINED IN THE SOUTHWEST CORNER AND NO IMPACTS
EXPECTED.
BY THURSDAY LOW LEVEL WINDS WILL HAVE TURNED AROUND TO SOUTH
SOUTHEAST ALLOWING THE AFOREMENTIONED SLOW WARMING
TREND...MEANWHILE A DEEP LAYER THERMAL RIDGE WILL HAVE BUILT
DOWN THE HIGH PLAINS FROM THE DAKOTAS TO THE TEXAS PANHANDLE. THIS
RIDGE WILL SUBSEQUENTLY SHIFT EASTWARD...HOWEVER A 500 MB
SHORTWAVE MOVING AROUND ITS PERIPHERY WILL ALSO DIG DOWN ACROSS
MINNESOTA AND WISCONSIN AND FLATTEN THE RIDGE DOWN TOWARD THE
SOUTH. THIS SHORTWAVE WILL LIKELY GENERATE SOME THUNDERSTORMS FROM
THURSDAY NIGHT INTO FRIDAY...THE MAJORITY OF WHICH WILL REMAIN TO
OUR NORTHEAST BUT SOME MAY CLIP AREAS AROUND MASON CITY AND
WATERLOO AROUND FRIDAY MORNING. HAVE MAINTAINED CHANCE POPS TO
ACCOUNT FOR THIS. BY LATE IN THE DAY FRIDAY...IN WAKE OF THESE
STORMS...A WEAKLY DEFINED SURFACE TROUGH WILL BE DRAPED FROM
CENTRAL MINNESOTA DOWN TO WESTERN NEBRASKA. SOUTH OF THIS BOUNDARY
MOST OF OUR FORECAST AREA...ESPECIALLY THE SOUTHERN HALF...SHOULD
SEE MORE ROBUST WARMING WITH TEMPERATURES IN THE LOWER 80S
POSSIBLE. HOWEVER...THIS WILL BE BROUGHT TO A QUICK END AS ANOTHER
500 MB WAVE COMING OVER THE NORTHERN ROCKIES OF MONTANA WILL
RAPIDLY DEEPEN AS IT MOVES SOUTHEAST OVER THE MIDWEST ON FRIDAY
NIGHT AND SATURDAY. THIS WILL SHARPEN THE SURFACE TROUGH AND PUSH
IT ACROSS IOWA ON SATURDAY.
THE PASSAGE OF THE SURFACE FRONT AND MID LEVEL WAVE ON FRIDAY
NIGHT/SATURDAY WILL UNDOUBTEDLY TRIGGER SOME SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. HOWEVER...COVERAGE AND TIMING
REMAIN SOMEWHAT UNCERTAIN AND HAVE KEPT ONLY 40 TO 60 POPS IN EACH
PERIOD FOR NOW UNTIL SOLUTIONS CONVERGE. OF POTENTIALLY GREATER
CONSEQUENCE IS HURRICANE ODILE...WHICH IS CURRENTLY MAKING
LANDFALL OVER THE BAJA CALIFORNIA AND WILL DRIFT SLOWLY
NORTHEASTWARD OVER THE DESERT SOUTHWEST...REFLECTED BY A LARGE
SLUG OF DEEP MOISTURE AND A WEAKENING LOW PRESSURE CENTER. SOME
GFS SOLUTIONS HAVE BEEN ADVECTING THE MOISTURE FAR ENOUGH
NORTHEAST BY THE END OF THE WEEK THAT IT IS DRAWN UP ALONG THE
SURFACE FRONT...BRINGING A SIGNIFICANT HEAVY RAIN THREAT TO PARTS
OF THE REGION AND POTENTIALLY IOWA. HOWEVER...THESE SOLUTIONS HAVE
BEEN INCONSISTENT AND THE ECMWF HAS BEEN KEEPING THE ODILE
MOISTURE FAR ENOUGH TO THE SOUTHWEST THAT IT IS NOT DRAWN EASTWARD
UNTIL THE FRONT HAS ALREADY PASSED THROUGH IOWA. THIS PARTICULAR
SCENARIO IS UNSTABLE IN THE SENSE THAT IT RELIES ON THE SLOW DRIFT
OF A CYCLONE JUST MAKING LANDFALL...AS WELL AS THE TIMING AND
MOTION OF OTHER ATMOSPHERIC FEATURES THAT DO NOT EVEN EXIST YET.
WE WILL CONTINUE TO MONITOR THIS POTENTIAL THROUGHOUT THE WEEK.
&&
.AVIATION...15/12Z
ISSUED AT 649 AM CDT MON SEP 15 2014
MVFR/VFR CONDITIONS WILL AFFECT IA THIS MORNING WITH SCT SHOWERS
AND STORMS SOUTH AND LIGHT-MODERATE RAIN NORTH. ALL THE PRECIP
SHOULD END BY EARLY AFTERNOON AS SYSTEM EXITS WITH MOSTLY CLEAR
SKIES THROUGH THE REMAINDER OF THE PERIOD. SFC ANALYSIS PLACES
FRONTAL BOUNDARY ALONG KLWD-KAMW-KIIB LINE AT 11Z AND IS EXPECTED
TO SAG SOUTHWARD OUT OF THE STATE BY 18Z. WINDS WILL BECOME NLY
AFTER ITS PASSAGE AND THEN LIGHT/VARIABLE BY TONIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SKOW
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
649 AM CDT MON SEP 15 2014
.SHORT TERM /TODAY/...
ISSUED AT 323 AM CDT MON SEP 15 2014
PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS TODAY. MEAN
TROUGH CONTINUES TO ADVANCE THROUGH THE NRN CONUS THIS MORNING.
WEAK KINEMATICALLY FORCED PRECIP CONTINUES OVER SD/MN/WI JUST
BRUSHING NRN IA. THIS IS DRIVEN BY DPVA AHEAD OF POTENT DAKOTAS
SHORT WAVE/PV ANOMALY AND RIGHT ENTRANCE REGION OF GREAT LAKES JET
SEGMENT. FARTHER SOUTH WARM/THETA-E ADVECTION HAS STRENGTHENED IN
RESPONSE ALONG MO VALLEY BAROCLINIC AND FRONTOGENESIS ZONE.
INSTABILITY HAS INCREASED IN THIS RETURN FLOW WITH UNCAPPED 500
J/KG MUCAPES ENTERING SWRN IA...ROOTED 1-1.5KM. EFFECTIVE SHEAR IS
PUSHING 50KTS IN THIS AREA AND RESULTED IN A FEW SUB SEVERE HAIL
REPORTS OVER FAR ERN NE.
THIS THERMODYNAMIC FORCING AND INSTABILITY WILL BE LIMITED IN
TIME HOWEVER. RAP 305K ISENT SURFACE SHOWS THIS LIFT PUSHING
SOUTHWARD OUT OF THE STATE WITH TIME AS LONG WAVE TROUGH
APPROACHES. THIS WILL BRING MUCH OF THE STATE UNDER THE INFLUENCE
OF KINEMATIC RATHER THAN THERMODYNAMIC FORCING WHICH SHOULD SPREAD
INTO IA WITH TIME. MOISTURE WAS LIMITED INITIALLY BUT EXPECT
FORCING TO SOON INDUCE SATURATION AND MORE WIDESPREAD PRECIP. THE
PRONOUNCED SUBSIDENCE/LIFT COUPLET WILL BE EXITING ERN SECTIONS BY
18Z HOWEVER SO MUCH OF THE FORECAST AREA SHOULD BE DRY BY EARLY
AFTERNOON.
08Z SURFACE ANALYSIS APPEARS TO SHOW TWO FRONTS...ONE FROM KS/MO
TO BETWEEN CRESTON AND DES MOINES...WITH ANOTHER FROM THE AMES
AREA TO JUST SOUTH OF WATERLOO. THESE SHOULD QUICKLY PHASE AND
EXIT THE AREA BY 18Z PRODUCING PROBLEMATIC AND IN PLACES NON-
DIURNAL TEMP TRENDS. READINGS SHOULD REBOUND LITTLE SE WITH SYSTEM
EFFECTS LINGERING LONGER. HOWEVER FAR NW SHOULD SEE THE PRECIP END
EARLIER WITH CLEARING AND MORE POTENTIAL FOR MIXING AND REBOUND.
THIS RESULTS IN FAIRLY HOMOGENEOUS AND LOW CONFIDENCE TEMP
FORECAST IN THE LOWER 60S NEAR MOS GUIDANCE BLEND.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 323 AM CDT MON SEP 15 2014
FROM TONIGHT THROUGH THURSDAY THE WEATHER WILL BE DRY AND QUIET
WITH A SLOW WARMING TREND. A SURFACE HIGH PRESSURE AREA WILL BE
DRAPED ACROSS IOWA OVERNIGHT ALLOWING TEMPERATURES TO FALL INTO
THE UPPER 30S IN SOME AREAS...HOWEVER NO SIGNIFICANT FROST EFFECTS
ARE ANTICIPATED AS TEMPERATURES SHOULD NOT DROP TO THE LEVELS SEEN
ON SATURDAY MORNING. PATCHY TO POSSIBLY WIDESPREAD FOG DEVELOPMENT
IS ANTICIPATED PARTICULARLY IN AREAS WHERE RAIN FALLS THIS
MORNING. ON TUESDAY NIGHT AND WEDNESDAY A ZONE OF WARM AIR
ADVECTION JUST TO OUR SOUTHWEST SHOULD GENERATE SOME SHOWERS AND
STORMS FROM EASTERN NEBRASKA DOWN INTO MISSOURI...BUT THIS
ACTIVITY IS EXPECTED TO MISS OUR FORECAST AREA WITH JUST SOME
SLIGHT POPS MAINTAINED IN THE SOUTHWEST CORNER AND NO IMPACTS
EXPECTED.
BY THURSDAY LOW LEVEL WINDS WILL HAVE TURNED AROUND TO SOUTH
SOUTHEAST ALLOWING THE AFOREMENTIONED SLOW WARMING
TREND...MEANWHILE A DEEP LAYER THERMAL RIDGE WILL HAVE BUILT
DOWN THE HIGH PLAINS FROM THE DAKOTAS TO THE TEXAS PANHANDLE. THIS
RIDGE WILL SUBSEQUENTLY SHIFT EASTWARD...HOWEVER A 500 MB
SHORTWAVE MOVING AROUND ITS PERIPHERY WILL ALSO DIG DOWN ACROSS
MINNESOTA AND WISCONSIN AND FLATTEN THE RIDGE DOWN TOWARD THE
SOUTH. THIS SHORTWAVE WILL LIKELY GENERATE SOME THUNDERSTORMS FROM
THURSDAY NIGHT INTO FRIDAY...THE MAJORITY OF WHICH WILL REMAIN TO
OUR NORTHEAST BUT SOME MAY CLIP AREAS AROUND MASON CITY AND
WATERLOO AROUND FRIDAY MORNING. HAVE MAINTAINED CHANCE POPS TO
ACCOUNT FOR THIS. BY LATE IN THE DAY FRIDAY...IN WAKE OF THESE
STORMS...A WEAKLY DEFINED SURFACE TROUGH WILL BE DRAPED FROM
CENTRAL MINNESOTA DOWN TO WESTERN NEBRASKA. SOUTH OF THIS BOUNDARY
MOST OF OUR FORECAST AREA...ESPECIALLY THE SOUTHERN HALF...SHOULD
SEE MORE ROBUST WARMING WITH TEMPERATURES IN THE LOWER 80S
POSSIBLE. HOWEVER...THIS WILL BE BROUGHT TO A QUICK END AS ANOTHER
500 MB WAVE COMING OVER THE NORTHERN ROCKIES OF MONTANA WILL
RAPIDLY DEEPEN AS IT MOVES SOUTHEAST OVER THE MIDWEST ON FRIDAY
NIGHT AND SATURDAY. THIS WILL SHARPEN THE SURFACE TROUGH AND PUSH
IT ACROSS IOWA ON SATURDAY.
THE PASSAGE OF THE SURFACE FRONT AND MID LEVEL WAVE ON FRIDAY
NIGHT/SATURDAY WILL UNDOUBTEDLY TRIGGER SOME SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. HOWEVER...COVERAGE AND TIMING
REMAIN SOMEWHAT UNCERTAIN AND HAVE KEPT ONLY 40 TO 60 POPS IN EACH
PERIOD FOR NOW UNTIL SOLUTIONS CONVERGE. OF POTENTIALLY GREATER
CONSEQUENCE IS HURRICANE ODILE...WHICH IS CURRENTLY MAKING
LANDFALL OVER THE BAJA CALIFORNIA AND WILL DRIFT SLOWLY
NORTHEASTWARD OVER THE DESERT SOUTHWEST...REFLECTED BY A LARGE
SLUG OF DEEP MOISTURE AND A WEAKENING LOW PRESSURE CENTER. SOME
GFS SOLUTIONS HAVE BEEN ADVECTING THE MOISTURE FAR ENOUGH
NORTHEAST BY THE END OF THE WEEK THAT IT IS DRAWN UP ALONG THE
SURFACE FRONT...BRINGING A SIGNIFICANT HEAVY RAIN THREAT TO PARTS
OF THE REGION AND POTENTIALLY IOWA. HOWEVER...THESE SOLUTIONS HAVE
BEEN INCONSISTENT AND THE ECMWF HAS BEEN KEEPING THE ODILE
MOISTURE FAR ENOUGH TO THE SOUTHWEST THAT IT IS NOT DRAWN EASTWARD
UNTIL THE FRONT HAS ALREADY PASSED THROUGH IOWA. THIS PARTICULAR
SCENARIO IS UNSTABLE IN THE SENSE THAT IT RELIES ON THE SLOW DRIFT
OF A CYCLONE JUST MAKING LANDFALL...AS WELL AS THE TIMING AND
MOTION OF OTHER ATMOSPHERIC FEATURES THAT DO NOT EVEN EXIST YET.
WE WILL CONTINUE TO MONITOR THIS POTENTIAL THROUGHOUT THE WEEK.
&&
.AVIATION...15/12Z
ISSUED AT 649 AM CDT MON SEP 15 2014
MVFR/VFR CONDITIONS WILL AFFECT IA THIS MORNING WITH SCT SHOWERS
AND STORMS SOUTH AND LIGHT-MODERATE RAIN NORTH. ALL THE PRECIP
SHOULD END BY EARLY AFTERNOON AS SYSTEM EXITS WITH MOSTLY CLEAR
SKIES THROUGH THE REMAINDER OF THE PERIOD. SFC ANALYSIS PLACES
FRONTAL BOUNDARY ALONG KLWD-KAMW-KIIB LINE AT 11Z AND IS EXPECTED
TO SAG SOUTHWARD OUT OF THE STATE BY 18Z. WINDS WILL BECOME NLY
AFTER ITS PASSAGE AND THEN LIGHT/VARIABLE BY TONIGHT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1159 AM EDT MON SEP 15 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 305 AM EDT MON SEP 15 2014
A COLD FRONT WILL BRING SOME RAIN TODAY. FAIR WEATHER WILL RETURN
TONIGHT AS HIGH PRESSURE MOVES IN. THE NEXT CHANCE FOR RAIN WILL
BE OVER THE WEEKEND AS ANOTHER COLD FRONT MOVES THROUGH.
&&
.UPDATE...
ISSUED AT 1156 AM EDT MON SEP 15 2014
IN THE PROCESS OF SCALING BACK POPS EARLY THIS AFTERNOON BASED ON
CURRENT RADAR TRENDS AND VERY LIGHT RAIN REPORTED UPSTREAM OVER
WISCONSIN. AM FAVORING LATEST HRRR SOLUTIONS THAT DISSIPATE
CURRENT E-W FGEN BAND OF PRECIP OVER OUR CENTRAL ZONES AND
REFOCUS PRECIPITATION TO OUR SOUTHEAST ZONES LATER THIS AFTERNOON.
UPDATES COMING OUT SHORTLY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 305 AM EDT MON SEP 15 2014
NARROW LINE OF SHOWERS ACROSS THE NORTHERN LOWER MICHIGAN ATTM
WILL BE EXPANDING AND MOVING SOUTH TODAY AS UPPER DIVERGENCE
PRECEDES PASSAGE OF 500 MB TROUGH AXIS AND SFC COLD FRONT. RAIN
SHOULD BE ENDING FROM NORTHWEST TO SOUTHEAST LATE THIS AFTERNOON
AND EARLY EVENING WITH STORM TOTAL QPF EXPECTED TO BE AROUND A
QUARTER INCH. HEIGHT RISES FOLLOW TONIGHT AS UPPER TROUGH SHIFTS
EAST WITH SFC RIDGING BUILDING IN SO WE SHOULD SEE CLEARING BY
MIDNIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 AM EDT MON SEP 15 2014
THE LONG TERM PORTION WILL START OUT RATHER QUIET...AND WILL BECOME
A BIT UNSETTLED TOWARD NEXT WEEKEND.
THE ONLY ITEM OF NOTE THROUGH THU NIGHT WILL BE A BACKDOOR COLD
FRONT THAT WILL APPROACH THE AREA FROM THE NE ON WED NIGHT AND INTO
EARLY THU. WE WILL SEE A FAIRLY ROBUST UPPER TROUGH SLIP BY JUST TO
OUR NE AT THAT TIME. THIS WILL TRY TO DRAG A COLD FRONT INTO THE
AREA. WE WILL SEE A SFC RIDGE MOVE NORTH OF THE AREA AND LOW LEVEL
NE FLOW WILL TRY TO ADVECT COOLER AIR IN ACROSS THE STATE.
WE WILL SEE A WARM UP ACROSS THE AREA THEN LATE INTO THIS WEEK AND
AT LEAST THE FIRST HALF OF THE UPCOMING WEEKEND. THE TREND HAS BEEN
FOR LESS ENERGY TO MOVE OUT OF THE WRN STORM AND LIFT NE INTO
CANADA. WE WILL SEE AN UPPER RIDGE ACROSS THE ERN ROCKIES AND PLAINS
EVENTUALLY GET FLATTENED OUT WITH JET ENERGY PLOWING INTO IT. AS
THIS IS HAPPENING...A COLD FRONT WILL BEGIN TO APPROACH THE AREA
WITH A NICE FLOW OF MOISTURE COMING IN FROM THE GULF. THE FRONT
LOOKS TO POTENTIALLY LAY OUT ALONG THE NEARLY ZONAL PATTERN AND
STALL OUT.
WE COULD BE LOOKING AT MULTIPLE ROUNDS OF RAIN IF THIS FRONT STALLS
OUT NEAR THE AREA. IT IS NOT A GIVEN THAT IT WILL STALL OUT...AND IT
COULD BE MORE PROGRESSIVE AND MOVE THROUGH A LITTLE QUICKER. EITHER
WAY...THE BEST CHCS OF RAIN LOOK TO BE CENTERED AROUND SAT WITH
WARMER AIR. TEMPS WILL EVENTUALLY COOL OFF LATE IN THE PERIOD OR
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 721 AM EDT MON SEP 15 2014
RAIN SHOWERS WILL BE MOVING IN THIS MORNING WITH MVFR CONDITIONS
MUCH OF THE AFTERNOON AND EVENING. CONDITIONS SHOULD IMPROVE LATE
TONIGHT AS THE RAIN MOVES OUT. SOUTHWEST WINDS TODAY WILL TURN
NORTHWEST TONIGHT BUT GENERALLY REMAIN BLO 10 KNOTS.
&&
.MARINE...
ISSUED AT 305 AM EDT MON SEP 15 2014
WILL DROP THE SMALL CRAFT ADVISORY AT 5 AM AS WINDS AND WAVES ARE
DECREASING...WITH 2 TO 4 FOOT WAVES EXPECTED TODAY.
&&
.HYDROLOGY...
ISSUED AT 305 AM EDT MON SEP 15 2014
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
719 AM EDT MON SEP 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT MON SEP 15 2014
LATEST WV IMAGERY AND RUC ANALYSIS SHOW A BROAD MID/UPPER LEVEL
TROUGH FROM CENTRAL CANADA INTO THE NRN CONUS WITH A SHORTWAVE NOTED
UPSTREAM OVER THE DAKOTAS. DPVA AND MOISTURE AHEAD OF THIS SHORTWAVE
WAS SUPPORTING A MASS OF CLOUDS ALONG WITH SCT SHRA OVER THE SRN
HALF OF MN AND CENTRAL WI. THE NRN EDGE OF THE MID-HIGH CLOUD SHIELD
WAS REACHING INTO THE SCNTRL PORTION OF UPPER MI WHILE THE REST OF
THE FORECAST AREA WAS GENERALLY CLOUD FREE EARLY THIS MORNING.
TODAY...MODELS SHOW SOME WEAK Q-VECT CONV ASSOC WITH UPPER TROUGH
OVERHEAD AND ON NRN EDGE OF FORCING FROM DAKOTAS SHORTWAVE PASSING
SOUTH. SBCAPE OF 50-100 J/KG ALONG WITH SFC-7H LAPSE RATES OF 7.5C
OR HIGHER WHICH COULD SUPPORT SOME SCATTERED LIGHT SHOWERS OR
SPRINKLES AS DAYTIME HEATING INCREASES. BEST CHANCE FOR SHRA WILL BE
CENTRAL AND EAST WHERE AWAY FROM LAKE SUPERIOR WHERE BETTER DAYTIME
HEATING IS EXPECTED. WL MAINTAIN SLIGHT CHC POPS FOR THESE
COUNTIES.
TONIGHT...CLEARING SKIES AND LIGHT WINDS OVER THE WESTERN INTERIOR
ALONG WITH PWAT VALUES AOB 50 PCT OF NORMAL SHOULD SUPPORT AREAS OF
FROST AS MIN TEMPS DIP NEAR THE FREEZING MARK ESPECIALLY ALONG THE
WI BORDER. HAVE INCLUDED GOGEBIC...ONTONAGON...IRON...BARAGA...SRN
HOUGHTON AND DICKINSON COUNTIES IN A FROST ADVISORY FOR LATE TONIGHT
INTO EARLY TUE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 332 AM EDT MON SEP 15 2014
OVERALL PATTERN IS WELL AGREED ON BY MODELS THROUGH NEXT WEEKEND.
UPPER LEVEL PATTERN TUE AND WED WILL FEATURE A RIDGE OVER THE WRN
CONUS AND A TROUGH OVER THE ERN CONUS. PATTERN BEGINS TO BREAK DOWN
THU...WITH A WEAK TROUGH MOVING ACROSS THE NCENTRAL CONUS LATE FRI
AND SAT.
SFC HIGH PRESSURE WILL MAKE FOR A DRY AND SUNNY TUE WITH HIGH TEMPS
EVEN AROUND NORMAL IN THE MID TO UPPER 60S.
A SHORTWAVE TROUGH WILL MOVE ACROSS FAR NRN QUEBEC ON TUE...DROPPING
THE ASSOCIATED COLD FRONT DOWN FROM THE NNE TUE NIGHT INTO WED AS
ANOTHER WEAKER SHORTWAVE DROPS DOWN ALONG THE FRONT. MOST MODELS
SHOWING QPF ALONG THE FRONT AND AHEAD OF THE SHORTWAVE...BUT EXACT
TIMING AND PLACEMENT IS STILL SOMEWHAT DISAGREED ON. WILL INCREASE
POPS GIVEN THE INCREASED CONFIDENCE IN PRECIP OCCURRING. WED LOOKS
QUITE A BIT COOLER THAN TUE...MAINLY OVER THE NRN HALF OF THE CWA
WHERE THE FRONT WILL PASS THROUGH EARLIER. EXPECT HIGHS RANGING FROM
AROUND 50 ALONG LAKE SUPERIOR TO 60 OVER THE SCENTRAL. ECMWF AND GEM
SHOW LIGHT QPF OVER THE CWA LATE WED INTO WED NIGHT...BUT WITH A
1025MB SFC HIGH CENTER OVER OR NEAR THE CWA DURING THIS TIME...WILL
LEAN TOWARD THE DRIER GFS AND NAM SOLUTIONS. MAY SEE FROST OVER
INTERIOR ERN UPPER MI WED NIGHT...BUT THE TEMPS WILL BE DEPENDENT ON
CLOUD COVER AND PRECIP CHANCES. WILL KEEP A COLD FORECAST WITH FROST
GIVEN PREFERENCE FOR DRIER SOLUTIONS.
THU LOOKS MOSTLY DRY...BUT RAIN CHANCES WILL INCREASE THU NIGHT
THROUGH SAT. INITIALLY...PRIMARY DRIVER FOR THE PRECIP WILL BE
WAA/ISENTROPIC LIFT RESULTING FROM BEEFY SSWLY LOW LEVEL FLOW
BETWEEN THE IMPENDING SFC TROUGH AND DEPARTING SFC HIGH. FORCING
THEM TRANSITIONS TO LARGE SCALE FORCING ALONG THE UPPER/SFC TROUGHS
ON SAT...BUT WILL RECEIVE AT LEAST SOME ADDITIONAL FORCING FROM
INSTABILITY. MODELS SHOW UP TO 700J/KG OF CAPE ON SAT...BUT THAT
WILL BE HIGHLY DEPENDENT ON CLOUD COVER AND OTHER FACTORS. THERE IS
POTENTIAL FOR DECENT CAPE GIVEN POSSIBILITY OF HOT SFC TEMPS AS
850MB TEMPS INCREASE TO 16C AHEAD OF THE COLD FRONT LAKE FRI NIGHT
INTO SAT. WILL NEED CONTINUE TO ASSESS THE SEVERE THREAT AS THE EVEN
APPROACHES.
COOLER AND DRIER WEATHER LOOKS TO BE IN STORE FOR SUN AS A SFC HIGH
MOVES INTO THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 718 AM EDT MON SEP 15 2014
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE FCST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT MON SEP 15 2014
HIGH PRESSURE MOVING OVER THE AREA WILL MAINTAIN WINDS GENERALLY
LESS THAN 20 KT TODAY. WSW WINDS MAY INCREASE TO 25 KTS MONDAY NIGHT
INTO TUESDAY AHEAD OF A COLD FRONT. WINDS THEN SHIFT TO NORTHEAST UP
TO 25 KTS IN THE WAKE OF THE COLD FRONT TUESDAY NIGHT. WINDS
DIMINISH TO LESS THAN 20 KTS LATER WED INTO THU AS HIGH PRESSURE
RIDGE CROSSES REGION. NEXT CHANCE OF STRONG WINDS ARRIVES FRIDAY
WITH SOUTH WINDS INCREASING TO 20 TO 30 KTS AHEAD OF DEVELOPING LOW
PRESSURE SYSTEM IN THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 9 AM EDT
/8 AM CDT/ TUESDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1000 AM EDT MON SEP 15 2014
.SYNOPSIS...
A FRONT STALLED ACROSS SOUTHERN GEORGIA WILL RETURN NORTH
TODAY...ONLY TO BE PUSHED SOUTH AGAIN TUESDAY AS HIGH PRESSURE BUILDS
EASTWARD ACROSS THE PLAINS STATES. THIS HIGH WILL MOVE ACROSS THE
MID-ATLANTIC STATES LATE IN THE WEEK...PROVIDING FALL- LIKE
WEATHER WEDNESDAY THROUGH SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM MONDAY...12Z RAOBS IN FROM BOTH MHX AND CHS. LOW LEVEL
MOISTURE LOOKS THICK ENOUGH THAT ANY BREAKS OF SUNSHINE ARE GOING TO
BE HARD TO COME BY. THE TEMPTATION TO NUDGE HIGH TEMP FORECAST DOWN
A FEW DEGREES IS GROWING-MOST MODEL GUIDANCE WAS TOO WARM YESTERDAY.
WILL MAKE DECISION BY NEXT UPDATE. OUR CURRENT POP FORECAST IS QUITE
LOW AND THEREFORE HARD TO ARGUE WITH BUT MAY TWEAK DOWN A BIT ESP
OVER NRN ZONES...TO OPEN UP A SLIGHTLY MORE PRONOUNCED GRADIENT
FAVORING NRN ZONES. PAST FEW RUNS OF THE HRRR HAVE BEEN PRETTY SCANT
IN QPF FORECAST ONCE THIS CURRENT BATCH MOVES OFF THE GRAND STRAND.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...MID LEVEL RIDGING WILL SHARPEN AND MOVE ACROSS
THE WEST COAST AS TROUGHING DEVELOPS ACROSS THE EASTERN THIRD OF THE
U.S. THIS TROUGH WILL EVENTUALLY PUSH A COLD FRONT THROUGH THE AREA
LATE TUESDAY INTO EARLY WEDNESDAY. WILL MAINTAIN A GOOD CHANCE OF
SHOWERS AND THUNDERSTORMS FOR TUESDAY AS THE LINGERING MOISTURE
WARRANTS AHEAD OF THE FRONT. MORE OF A SHOWERY SCENARIO FOR
WEDNESDAY ESPECIALLY ACROSS NORTH CAROLINA. STILL ENOUGH INSTABILITY
TO WARRANT SLIGHT CHANCE OF THUNDER NORTH WITH THUNDERSTORMS THE
PRIMARY MODE FOR SOUTH CAROLINA. TEMPERATURES STILL ON THE WARM SIDE
FOR TUESDAY IN THE MIDDLE 80S DROPPING A GOOD FIVE TO TEN DEGREES
WEDNESDAY. OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...THE EXTENDED FORECAST CONTINUES TO SHOW A MOSTLY
ZONAL MID LEVEL PATTERN INITIALLY WITH MORE AMPLITUDE DEVELOPING
LATE. THE WESTERLIES WILL SHOW CONFLUENCE ACROSS THE CENTRAL
PLAINS/GREAT LAKES WHICH WILL ALLOW A RATHER EXPANSIVE AREA OF
SURFACE HIGH PRESSURE TO BUILD DOWN THE EAST COAST. THIS WILL
MAINTAIN A SOMEWHAT DRY AND COOL FLOW ACROSS OUR FORECAST AREA.
THE HIGH WEAKENS AS MID LEVEL SUPPORT WANES AND HIGH PRESSURE
BUILDS ACROSS THE WESTERN U.S. AT THE MID LEVELS. THIS WILL SET
THE STAGE FOR ANOTHER SYSTEM TO AFFECT THE AREA LATE OR JUST
BEYOND THIS FORECAST PERIOD. TEMPERATURES WILL BE JUST A LITTLE
BELOW CLIMATOLOGY MODERATING EVER SO SLIGHTLY LATE IN THE PERIOD.
THE ONLY POPS ARE RELEGATED TO JUST OFFSHORE WHERE JUST ENOUGH
MOISTURE WARRANTS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...TIME HEIGHT CONFIRMS OBSERVATIONS WITH A MVFR CEILING AT
MOST SPOTS. WITH WEDGE STILL FIRMLY IN PLACE...LOOK FOR CLOUDY
CONDITIONS TO CONTINUE. A PATCH OF LIGHT RAIN MAY AFFECT MYR IN THE
NEAR TERM...BUT THATS ABOUT IT. NORTHEAST FLOW IS FORECAST THIS
MORNING...POSSIBLY REPLACED WITH A SOUTHEAST WIND ALONG THE
COAST...ALTHOUGH CONFIDENCE IS RATHER LOW IN THAT REGARD.
TONIGHT...CONTINUED CLOUDY WITH A SLIGHT CHANCE OF RAIN OVER THE
EXTREME SOUTHERN PORTION OF THE CWA.
EXTENDED OUTLOOK...CHANCE OF SHOWERS/TEMPO MVFR TUE AHEAD OF A COLD
FRONT. POST-FRONTAL MVFR CIGS MAY DEVELOP WED AS COOLER AIR WEDGES
INTO THE REGION. OTHERWISE EXPECT VFR THROUGH FRI.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM MONDAY...PRETTY QUIET OUT OVER THE WATERS. NO CHANGES
ANTICIPATED. PREVIOUS DISCUSSION SUMS THINGS UP NICELY:
AS OF 625 AM MONDAY...MODEL SFC PRESSURE PATTERN AND WEAK GRADIENT
SUPPORT A WEAK WEDGE THIS MORNING THAT WEAKENS AND GIVES WAY TO
THE APPROACHING AND DISSIPATING FRONTAL BOUNDARY FROM THE SOUTH.
LOOKING AT A SLOW VEERING TREND IN THE WIND FIELD...FROM NE THIS
MORNING TO EAST MIDDAY...AND SOUTHEAST THIS AFTERNOON AND EARLY
EVENING. FOR TONIGHT VARIABLE WINDS INITIALLY WILL BECOME WESTERLY
AS A COLD FRONT APPROACHES FROM THE WEST TOWARD DAYBREAK TUE. WIND
SPEEDS INITIALLY 10 TO 15 KT DUE TO THE WEDGE...WILL DROP BACK TO
AROUND 10 KT AS THE SFC PG WEAKENS. SIGNIFICANT SEAS WILL RUN 2 TO
3 FT WITH AN AVERAGE PERIOD OF 4 TO 5 SECONDS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...LIGHT WIND FIELDS WILL PREVAIL OVER THE WATERS
FOR MOST OF TUESDAY. IF ANYTHING...WINDS WILL HAVE A NORTHERLY
COMPONENT OF TEN KNOTS OR LESS. THE WINDS ACQUIRE MORE DEFINITION BY
WEDNESDAY MORNING AS A FRONT MOVES SLOWLY TO THE SOUTH. EXPECT AN
INCREASING NORTHEASTERLY FLOW OF 10-15 KNOTS. SIGNIFICANT SEAS
INCREASE FROM 2-3 FEET TO 3-5 FEET AND POSSIBLY SOME SIX FOOTERS
ACROSS THE OUTER WATERS WEDNESDAY.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...ESSENTIALLY A NORTHEAST FLOW THROUGH THE PERIOD.
THE STRONGEST WINDS WILL OCCUR LATE AS HIGH PRESSURE...ANCHORED
ACROSS THE NORTHEAST STRENGTHENS. SPEEDS WILL BE IN A 15-20 KNOT
RANGE CLOSER TO AND POSSIBLY JUST EXCEEDING THE HIGHER END BY FRIDAY
MORNING. SEAS WILL HOVER AT OR JUST BELOW SMALL CRAFT CRITERIA...3-5
FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MBB/DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
300 PM MST MON SEP 15 2014
...UPDATED AVIATION AND FIRE WEATHER...
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS THE REGION
TODAY ALONG WITH SOME AREAS OF BLOWING DUST. HOWEVER...MOISTURE WILL
INCREASE SUBSTANTIALLY ACROSS THE AREA ON TUESDAY AND THERE WILL BE
AN ELEVATED RISK OF HEAVY RAIN AND FLOODING ACROSS THE AREA THROUGH
THE END OF THE WEEK.
&&
.DISCUSSION...
CONSENSUS OF CONVECTIVE-ALLOWING MODELS STILL SUGGESTS SHOWER AND
THUNDERSTORM ACTIVITY WILL REMAIN CONCENTRATED ACROSS SOUTHERN AZ
LATE THIS AFTERNOON AND THIS EVENING. LATEST HRRR ALSO SHOWS SOME
POTENTIAL FOR CONVECTION ACROSS PINAL COUNTY THIS EVENING. MAIN
IMPACT ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ WILL BE THE
POSSIBILITY OF BLOWING DUST. THIS IS REFLECTED IN THE FORECAST AND
NO CHANGES ARE ANTICIPATED THIS MORNING. FOCUS REMAINS ON THE
POTENTIAL FOR HEAVY RAIN LATER THIS WEEK.
&&
.PREVIOUS DISCUSSION...
DEEPER MOISTURE REMAINS BOTTLED UP SOUTH OF THE INTERNATIONAL BORDER
THIS MORNING...AS PWATS ARE ONLY RUNNING AROUND 1.2 TO 1.4 INCHES
ACROSS THE LOWER DESERTS. VALUES WELL ABOVE 2 TO 2.5 INCHES HAVE
BEEN OBSERVED PER BLENDED TPW IMAGERY IN THE GULF OF CALIFORNIA AND
ARE SURGING NORTHWARD AS OF 09Z. MEANWHILE A BIT FURTHER NORTH
ACROSS ARIZONA AND SOUTHEAST CALIFORNIA...SKIES MOSTLY CLEAR WITH
TEMPS IN THE MID 80S.
FOR TODAY...CONVECTION WILL BE CONFINED MAINLY TO THE MOUNTAINS
NORTH/EAST OF PHOENIX AS WELL AS ACROSS SOUTHEAST ARIZONA. MLCAPES
ACROSS THE DESERTS ARE BARELY FORECAST TO EXCEED 100-200 J/KG SO OUR
PRECIP CHANCES ARE SLIM ACROSS THE DESERTS. HOWEVER WITH DEEP
SOUTHEASTERLY FLOW ALREADY IN PLACE...DECAYING STORMS WILL LIKELY
PUSH OUT SOME OUTFLOW WINDS OVER THE NORMALLY DUST-PRONE OPEN DESERT
AREAS LATE THIS AFTERNOON AND EVENING.
OBVIOUSLY THE MAIN FOCUS OF THE FORECAST IS ON THE IMPACTS
ASSOCIATED WITH HURRICANE ODILE. THE SURGE OF MOISTURE WILL OCCUR
LATE TONIGHT /FOLLOWING THIS EVENING`S DECAYING STORMS/ AND PWATS
WILL SKYROCKET CLOSE TO 2 INCHES BY TUESDAY MORNING. THESE VALUES
WOULD NORMALLY BE UNHEARD OF FOR SEPTEMBER...EXCEPT WE SAW SIMILAR
VALUES JUST LAST WEEK. ELEVATED PWATS WILL REMAIN ACROSS THE REGION
THROUGH AT LEAST THURSDAY...IF NOT INTO FRIDAY WHEN A LARGER SCALE
TROUGH USHERS IN SOUTHWESTERLY FLOW ALOFT. IF ANYTHING HAS CHANGED
WITH RECENT MODEL RUNS...IT WOULD APPEAR THE AXIS OF HIGHEST
MOISTURE HAS SHIFTED A BIT TO THE EAST. WHERE THE AXIS WAS ONCE
POSITIONED SQUARELY OVER THE COLORADO RIVER...ITS NOW SPREAD OVER A
GOOD PORTION OF SOUTH-CENTRAL ARIZONA. AS USUAL...TRYING TO PINPOINT
THE EXACT TIMING/PLACEMENT OF THE HEAVIEST RAIN IS NEARLY IMPOSSIBLE
WITH TROPICAL SYSTEMS. THE 00Z RUNS OF THE ECMWF AND GFS BOTH SEEM
TO INDICATE A SHORTWAVE TROUGH MOVING THROUGH THE AREA ON WEDNESDAY
/PERHAPS AS EARLY AS WEDNESDAY MORNING/...WITH A SECONDARY TROUGH
SWEEPING THROUGH THURSDAY. I HAVE INCREASED POPS DURING THIS TIME
AND WILL HIGHLIGHT THESE TIMES AS THE MOST LIKELY TO SEE HEAVY
RAINFALL/FLOODING IMPACTS.
EVENTUALLY A LARGE SCALE TROUGH WILL MOVE THROUGH CALIFORNIA LATE IN
THE WEEK AND BEGIN ADVECTING SOMEWHAT DRIER AIR INTO THE REGION FROM
THE WEST. BOTH THE ECMWF AND GFS INDICATE STRONG SOUTHWESTERLY FLOW
AND A SHORTWAVE TROUGH MOVING THROUGH ON FRIDAY...WHICH WOULD LIKELY
RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS MAINLY EAST OF
THE COLORADO RIVER. THE EMPHASIS LATE IN THE WEEK WOULD SHIFT TO THE
NORTH/EAST OF PHOENIX GIVEN FAVORABLE UPSLOPE FLOW ALTHOUGH
SCATTERED SHOWERS WOULD STILL BE POSSIBLE ACROSS THE DESERTS. IT
LOOKS LIKE THE DEEPEST PWATS SHOULD BE ADVECTED EAST OF ARIZONA THIS
WEEKEND BUT UNTIL THEN...I KEPT POPS WELL ABOVE CLIMATOLOGICAL
NORMALS UNTIL SUNDAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
MODELS STILL SUGGEST SFC WINDS WILL TURN TO A W/NW DIRECTION JUST
BEFORE SUNSET...THOUGH MAY REMAIN VRBL FOR EXTENDED PERIODS.
CONFIDENCE IS WANING THAT MORE ORGANIZED SE OUTFLOW WILL IMPACT
TERMINALS...INSTEAD POSSIBLY A WEAKER OUTFLOW FROM THE NE MOVING
INTO THE PHOENIX METRO. REGARDLESS...A SUBSTANTIAL INCREASE IN
MOISTURE OVERNIGHT MAY LEAD TO REDUCED SLANTWISE VSBY TUESDAY
MORNING WITH MORE EXTENSIVE DEBRIS CLOUDS WITH CIGS AS LOW AS 7K FT
WITH POSSIBLE VIRGA. THOUGH CONFIDENCE IS STILL LOW...A FEW
SHRA/TSRA MAY BE POSSIBLE EVEN AS EARLY AS LATE TUESDAY MORNING.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THROUGH TUESDAY AFTERNOON
AS SHRA/TSRA SHOULD REMAIN WELL SOUTH AND EAST OF SERN CALIFORNIA
TERMINALS. HOWEVER...THERE MAY BE A PERIOD OF GUSTY SOUTH WINDS
OVERNIGHT (ESPECIALLY AT KBLH) ASSOCIATED WITH A SURGE OF A VERY
HUMID AIRMASS FROM THE GULF OF CALIFORNIA. THOUGH CONFIDENCE IS
LOW...THERE MAY BE AREAS OF CIGS NEAR THE 3K FT MVFR THRESHOLD
TUESDAY MORNING IN COMBINATION WITH THE GULF SURGE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
UNUSUALLY WET CONDITIONS WILL BE LIKELY THURSDAY AND FRIDAY ACROSS
ARIZONA...WITH THE POTENTIAL FOR SOMEWHAT LESS ACTIVITY OVER SERN
CALIFORNIA. SEVERAL AREAS COULD EXPERIENCE HEAVY RAINFALL AND
LOCALIZED FLOODING AS A RESULT. SHOWERS AND THUNDERSTORMS SHOULD
BECOME LESS NUMEROUS OVER THE WEEKEND...THOUGH WILL STILL LIKELY
PREVAIL OVER PARTS OF CNTRL ARIZONA. WITH THE VERY MOIST
CONDITIONS...AFTERNOON HUMIDITY VALUES WILL ONLY FALL INTO A 20-40
PERCENT RANGE WITH EXCELLENT OVERNIGHT RECOVERY. WINDS WILL
GENERALLY FAVOR A SOUTHERLY DIRECTION AND COULD BECOME GUSTY AROUND
THUNDERSTORMS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...MO
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1005 AM MST MON SEP 15 2014
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS THE REGION
TODAY ALONG WITH SOME AREAS OF BLOWING DUST. HOWEVER...MOISTURE WILL
INCREASE SUBSTANTIALLY ACROSS THE AREA ON TUESDAY AND THERE WILL BE
AN ELEVATED RISK OF HEAVY RAIN AND FLOODING ACROSS THE AREA THROUGH
THE END OF THE WEEK.
&&
.DISCUSSION...
CONSENSUS OF CONVECTIVE-ALLOWING MODELS STILL SUGGESTS SHOWER AND
THUNDERSTORM ACTIVITY WILL REMAIN CONCENTRATED ACROSS SOUTHERN AZ
LATE THIS AFTERNOON AND THIS EVENING. LATEST HRRR ALSO SHOWS SOME
POTENTIAL FOR CONVECTION ACROSS PINAL COUNTY THIS EVENING. MAIN
IMPACT ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ WILL BE THE
POSSIBILITY OF BLOWING DUST. THIS IS REFLECTED IN THE FORECAST AND
NO CHANGES ARE ANTICIPATED THIS MORNING. FOCUS REMAINS ON THE
POTENTIAL FOR HEAVY RAIN LATER THIS WEEK.
&&
.PREVIOUS DISCUSSION...
DEEPER MOISTURE REMAINS BOTTLED UP SOUTH OF THE INTERNATIONAL BORDER
THIS MORNING...AS PWATS ARE ONLY RUNNING AROUND 1.2 TO 1.4 INCHES
ACROSS THE LOWER DESERTS. VALUES WELL ABOVE 2 TO 2.5 INCHES HAVE
BEEN OBSERVED PER BLENDED TPW IMAGERY IN THE GULF OF CALIFORNIA AND
ARE SURGING NORTHWARD AS OF 09Z. MEANWHILE A BIT FURTHER NORTH
ACROSS ARIZONA AND SOUTHEAST CALIFORNIA...SKIES MOSTLY CLEAR WITH
TEMPS IN THE MID 80S.
FOR TODAY...CONVECTION WILL BE CONFINED MAINLY TO THE MOUNTAINS
NORTH/EAST OF PHOENIX AS WELL AS ACROSS SOUTHEAST ARIZONA. MLCAPES
ACROSS THE DESERTS ARE BARELY FORECAST TO EXCEED 100-200 J/KG SO OUR
PRECIP CHANCES ARE SLIM ACROSS THE DESERTS. HOWEVER WITH DEEP
SOUTHEASTERLY FLOW ALREADY IN PLACE...DECAYING STORMS WILL LIKELY
PUSH OUT SOME OUTFLOW WINDS OVER THE NORMALLY DUST-PRONE OPEN DESERT
AREAS LATE THIS AFTERNOON AND EVENING.
OBVIOUSLY THE MAIN FOCUS OF THE FORECAST IS ON THE IMPACTS
ASSOCIATED WITH HURRICANE ODILE. THE SURGE OF MOISTURE WILL OCCUR
LATE TONIGHT /FOLLOWING THIS EVENING`S DECAYING STORMS/ AND PWATS
WILL SKYROCKET CLOSE TO 2 INCHES BY TUESDAY MORNING. THESE VALUES
WOULD NORMALLY BE UNHEARD OF FOR SEPTEMBER...EXCEPT WE SAW SIMILAR
VALUES JUST LAST WEEK. ELEVATED PWATS WILL REMAIN ACROSS THE REGION
THROUGH AT LEAST THURSDAY...IF NOT INTO FRIDAY WHEN A LARGER SCALE
TROUGH USHERS IN SOUTHWESTERLY FLOW ALOFT. IF ANYTHING HAS CHANGED
WITH RECENT MODEL RUNS...IT WOULD APPEAR THE AXIS OF HIGHEST
MOISTURE HAS SHIFTED A BIT TO THE EAST. WHERE THE AXIS WAS ONCE
POSITIONED SQUARELY OVER THE COLORADO RIVER...ITS NOW SPREAD OVER A
GOOD PORTION OF SOUTH-CENTRAL ARIZONA. AS USUAL...TRYING TO PINPOINT
THE EXACT TIMING/PLACEMENT OF THE HEAVIEST RAIN IS NEARLY IMPOSSIBLE
WITH TROPICAL SYSTEMS. THE 00Z RUNS OF THE ECMWF AND GFS BOTH SEEM
TO INDICATE A SHORTWAVE TROUGH MOVING THROUGH THE AREA ON WEDNESDAY
/PERHAPS AS EARLY AS WEDNESDAY MORNING/...WITH A SECONDARY TROUGH
SWEEPING THROUGH THURSDAY. I HAVE INCREASED POPS DURING THIS TIME
AND WILL HIGHLIGHT THESE TIMES AS THE MOST LIKELY TO SEE HEAVY
RAINFALL/FLOODING IMPACTS.
EVENTUALLY A LARGE SCALE TROUGH WILL MOVE THROUGH CALIFORNIA LATE IN
THE WEEK AND BEGIN ADVECTING SOMEWHAT DRIER AIR INTO THE REGION FROM
THE WEST. BOTH THE ECMWF AND GFS INDICATE STRONG SOUTHWESTERLY FLOW
AND A SHORTWAVE TROUGH MOVING THROUGH ON FRIDAY...WHICH WOULD LIKELY
RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS MAINLY EAST OF
THE COLORADO RIVER. THE EMPHASIS LATE IN THE WEEK WOULD SHIFT TO THE
NORTH/EAST OF PHOENIX GIVEN FAVORABLE UPSLOPE FLOW ALTHOUGH
SCATTERED SHOWERS WOULD STILL BE POSSIBLE ACROSS THE DESERTS. IT
LOOKS LIKE THE DEEPEST PWATS SHOULD BE ADVECTED EAST OF ARIZONA THIS
WEEKEND BUT UNTIL THEN...I KEPT POPS WELL ABOVE CLIMATOLOGICAL
NORMALS UNTIL SUNDAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...AND SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND KBLH...
CURRENT LIGHT EASTERLY WINDS ACROSS THE PHX AREA WILL LIKELY LAST
THROUGH MOST OF TODAY BEFORE BRIEFLY TRANSITIONING TO LIGHT WESTERLY
LATE THIS AFTERNOON...WITH THE WINDS REVERTING BACK TO A
SOUTHEASTERLY DIRECTION THIS EVENING AS OUTFLOWS FROM DISTANT
THUNDERSTORMS MOVE INTO THE REGION. THERE IS A REMOTE CHANCE THAT
THESE OUTFLOWS COULD PRODUCE A BRIEF PERIOD OF BLOWING DUST AS THEY
PASS THROUGH...BUT CONFIDENCE IS FAR TO LOW TO INCLUDE IN THE
TAFS...FOR NOW. AS FAR AS THE SOUTHEAST CA TAF SITES ARE
CONCERNED...SKIES ARE EXPECTED TO REMAIN MOSTLY CLEAR THROUGH THE
TAF PERIOD...WITH LIGHT...MAINLY DIURNALLY-DRIVEN WINDS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
MOISTURE FROM THE REMAINS OF HURRICANE ODILE WILL LIKELY BE
AFFECTING THE REGION THROUGH THE FORECAST PERIOD...WITH LOCALLY
HEAVY RAIN AND HIGHLY ELEVATED HUMIDITY LEVELS...WITH GOOD TO
EXCELLENT OVERNIGHT RECOVERIES. WINDS TO REMAIN MAINLY ON THE LIGHT
SIDE...OUTSIDE OF THUNDERSTORMS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...PERCHA
FIRE WEATHER...PERCHA
THE PREVIOUS FORECAST DISCUSSION IN THIS PRODUCT FOR MORE DETAILS ON
THE UPCOMING RAIN AND POTENTIAL FLOODING EVENT.
&&
.AVIATION...VALID THRU 16/18Z.
TIGHTENED PRESSURE GRADIENT OVER THE EASTERN HALF OF THE AREA WILL
MAINTAIN EASTERLY FLOW TODAY FOR MOST TERMINALS. THE GRADIENT WILL
RELAX DURING THE LATE AFTERNOON HOURS WITH THE WINDS DECREASING A
BIT AS A RESULT. MOSTLY CLEAR SKIES WITH ONLY ISOLATED CONVECTION
EXPECTED TO DEVELOP THIS AFTERNOON AND EVENING. CHANCES MAY INCREASE
OVERNIGHT BEFORE A STRONG INCREASE IN SHOWER AND THUNDERSTORM
CHANCES MOST OF THE REST OF THE WEEK. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THE EASTERLY BREEZE AFFECTING THE EASTERN HALF OF
THE AREA IS NOW EXPECTED TO CONTINUE THROUGH MUCH OF TODAY. IT
WILL EASE UP DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
ISOLATED TO SCATTERED CONVECTION DEVELOPING THIS
AFTERNOON...ESPECIALLY SOUTH OF TUCSON AND NEAR MOUNTAINS.
THEN ALL FOCUS GOES TO THE INCREASE MOISTURE AS MAJOR HURRICANE
ODILE EDGES NORTHWARD. DEEPER MOISTURE IS EXPECTED TO BE FORCED
NORTH ACROSS THE AREA BY MONDAY EVENING WITH CONVECTION POSSIBLE
MONDAY NIGHT. THEN THE DEEP MOISTURE WILL BE IN PLACE THROUGH
FRIDAY FOR AN ENHANCED THREAT OF SHOWERS AND THUNDERSTORMS WITH A
POTENTIAL FOR LOCALLY HEAVY RAINS. TIMING FOR THE MOISTURE MOVING
OUT OF THE REGION REMAINS QUESTIONABLE AT THIS TIME...THOUGH WILL
LIKELY SEE A DOWNWARD BY THE WEEKEND AS UPPER LEVEL TROF PUSHES THRU
THE NORTHERN HALF OF THE STATE.
&&
.DISCUSSION...SUFFICIENT MOISTURE ACROSS SOUTHERN ARIZONA WITH
PRECIPITABLE WATER AROUND 1.3 INCHES WITH MODESTLY WARM MID LEVEL
TEMPERATURES. AS IT STANDS IT WOULD BE ANOTHER MEAGER CONVECTIVE
DAY. A COUPLE OF FACTORS SHOWING MORE PROMISE LATER TODAY AND
TONIGHT WITH MOISTURE INCREASING THROUGH THE MID GULF AND SOUTHERN
TO MID SONORA. THIS FETCH OF DEEP MOISTURE WILL PUSH INTO SOUTHERN
ARIZONA OVER THE NEXT 24 HOURS WITH HRRR STREAMLINES FORECASTING A
STRONG RESPONSE AT THE SURFACE AS WELL TODAY. WE SHOULD SEE
INCREASING COVERAGE THIS AFTERNOON...BUT STILL MAINLY SOUTH AND
SOUTHWEST OF TUCSON. ECMWF KEYS ON AN IMPULSE PUSHING UP FROM SONORA
THROUGH EASTERN ZONES TONIGHT INTO TUESDAY WITH A FOCUS ON COCHISE
AND SANTA CRUZ COUNTIES TONIGHT.
MOISTURE RAMPS UP INTO TUESDAY WITH A STRONG THUNDERSTORM AFTERNOON
SHAPING UP ALONG WITH POSSIBLE ORGANIZED CONVECTIVE OUTFLOWS AND
LOCALLY HEAVY RAIN UNDER STRONGER CELLS. THE ONLY THING THAT LOOKS
LIKE IT COULD KEEP TUESDAY AFTERNOON FROM BEING ACTIVE IS WITH THE
SHARP MOISTURE GRADIENT WE COULD ACTUALLY SEE INCREASING SHOWER AND
THUNDERSTORM ACTIVITY EARLY TO MID THURSDAY MORNING TO TAKE THE EDGE
OF THE POTENTIAL INSTABILITY AND WIND PROFILE COMBO TUE AFTERNOON.
AFTER THAT ODILE AND THE DEVELOPING WEST COAST TROUGH DICTATE OUR
WEATHER. MAJOR HURRICANE ODILE SLAMMED INTO FAR SOUTHERN BAJA
PENINSULA OVER THE LAST SEVERAL HOURS WITH A 2 AM FORECAST TRACK
THAT BRINGS THE REMNANT INTO THE FAR NORTHERN GULF OF CALIFORNIA
THURSDAY AS A DEPRESSION. AT THAT POINT IT COULD TRACK RIGHT OVER US
AND COMPLETE A SOLID DRENCHING FOR MUCH OF SE AZ. WE`LL NEED TO
WATCH HOW WELL SHE MAINTAINS HER INTENSITY AND CONTINUE TO MONITOR
HER TRACK AND POTENTIAL INTERACTION WITH THE TROUGH...BUT AT THIS
POINT IT LOOKS LIKE A WET WEEK. OUR FOCUS AFTER THE INITIAL SHOT OF
MOISTURE EARLY TO LATE TUESDAY IS ON 18Z WED TO 06Z FRI (LATER
WEDNESDAY AFTERNOON THROUGH THURSDAY NIGHT) TIME PERIOD WITH THE
TRACK OF THE REMNANT CIRCULATION. HOWEVER...ANY TIME AFTER MONDAY
NIGHT WE COULD SEE ONE PERIOD OF LOCALLY HEAVY RAINFALL OR SEVERAL.
OUR CURRENT 5 DAY STORM TOTAL QPF RANGES FROM .75 TO 1.75 INCHES IN
VALLEY LOCATIONS AND 1.5 TO 3.5 INCHES IN MOUNTAIN LOCATIONS WHICH
IS IN DECENT AGREEMENT WITH WPC ESTIMATES. IT`S LIKELY TO BE A BUSY
WEEK BUT THERE WILL ALSO BE SOME DOWN PERIODS IN BETWEEN OUR BEST
PRECIP CHANCES.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TAUNTON MA
324 PM EDT MON SEP 15 2014
.SYNOPSIS...
A COLD FRONT WILL SWEEP SOUTHERN NEW ENGLAND BRINGING WITH THE
CHANCE OF SCATTERED SHOWERS BEGINNING AFTER MIDNIGHT TONIGHT
THROUGH TUESDAY. MAINLY DRY BUT COOLER THAN NORMAL WEATHER FOLLOWS
WEDNESDAY THROUGH SATURDAY. TEMPERATURES THEN MODERATE TO NEAR
NORMAL BY THE END OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
INTO TONIGHT...
A FALL-LIKE CHILL REMAINS IN THE AIR AS SCATTERED TO BROKEN
PANCAKE CUMULUS LINGER ACROSS THE SKY. SHOULD SEE PRESENT HIGH
TEMPERATURES AROUND THE UPPER-60S DROP TOWARDS THE LOWER-60S BY
SUNDOWN.
TONIGHT INTO TUESDAY...
A MODEST MID-LEVEL IMPULSE WILL INVOKE WEAK TROUGHING AS IT ROUNDS
THE BASE OF A DEEPER-LOW OVER THE NE-CANADIAN MARITIMES. CONSIDERING
LOW-LEVEL CONVERGENCE OF A CONTINENTAL-MOIST AIRMASS UNDERGOING MID-
LEVEL ENHANCED ASCENT COLLOCATED WITH A REGION OF FRONTOGENETICAL
FORCING AND RIGHT-ENTRANCE-REGION OF THE UPPER-LEVEL JET /WHEW/...
WOULD EXPECT SCATTERED LIGHT TO MODERATE SHOWER ACTIVITY ALONG A
LINE AHEAD OF THE SURFACE COLD FRONT. THE LATEST HRRR IS SHOWING
SUCH A TREND FAIRLY WELL ACROSS THE E GREAT LAKES BY MIDNIGHT
TUESDAY.
BUT A FEW THINGS WORTHY OF NOTE...NOT AN IMPRESSIVELY MOIST-AIRMASS
WITH PWATS OF 1.00-1.25 INCHES. SUBSIDENCE AND DRY AIR CONTINUE TO
PREVAIL SE...SQUEEZED BETWEEN THE APPROACHING MID-LEVEL IMPULSE AND
WELL-OFFSHORE SUBTROPICAL AXIS BUCKLED BY THE MEANDERING HURRICANE
EDOUARD. ANOMALOUSLY COOLER FOR THIS TIME OF YEAR OVER MUCH OF THE
REGION...LOW CONFIDENCE CONCERNING THUNDER AND INSTABILITY.
SO WILL NOT GO WITH A MENTION OF THUNDER. NOT EXPECTING A WASHOUT.
WILL KEEP THE HIGHEST CATEGORICAL POPS TOWARDS THE W ESPECIALLY
ALONG THE SLOPES OF HIGHER TERRAIN. WILL TAPER TO CHANCE POPS OFF
TOWARDS THE SE AS ACCOMPANYING DYNAMICS TO THE DISTURBANCE SHIFT TO
THE NE SHUNTING THE SURFACE COLD FRONT INTO A REGION OF SUBSIDENCE
AND DRIER AIR. ELSEWHERE...EXPECTING AROUND A TENTH FOR AREAS OF W
NEW ENGLAND...WITH A FEW HUNDREDTHS ACROSS CENTRAL AND E. MANY NOT
SEE ANY PRECIPITATION WHATSOEVER FOR E/SE MASSACHUSETTS.
&&
.SHORT TERM /TUESDAY NIGHT/...
TUESDAY NIGHT...
COLD FRONT PUSHING OFFSHORE. SOME BREEZY N/NW-FLOW REARWARD IS
CERTAINLY PLAUSIBLE INITIALLY...BUT HIGH PRESSURE QUICKLY FOLLOWS
ALLOWING WINDS TO RELAX.
THOUGH THE POSSIBILITY OF SOME MID-LEVEL SCATTERED CLOUD DECKS WILL
EXIST...THERE IS ALSO THE POTENTIAL OF EFFECTIVE RADIATIONAL COOLING
OVERNIGHT WHICH WOULD LIKELY RESULT IN ABNORMAL LOWS INTO THE 40S
ALONG WITH AREAS OF DENSE FOG...ESPECIALLY FOR THOSE REGIONS THAT
RECEIVED A MODEST RAIN OVER THE PAST 24 HOURS /THINKING THE WEST-
AND CENTRAL-INTERIOR...ESPECIALLY THE MID-CT RIVER VALLEY/.
LOWS INTO THE 40S WITH THE POTENTIAL FOR UPPER-30S ACROSS THE HIGH
TERRAIN OF N/W MASSACHUSETTS AND S NEW HAMPSHIRE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...
* MAINLY DRY AND COOLER THAN NORMAL WEATHER THROUGH SATURDAY
* TEMPERATURES MODERATE GOING INTO THE WEEKEND
* A COLD FRONT BRINGS SOME RAIN TO THE REGION SUNDAY INTO MONDAY
MODELS...INCLUDING ENSEMBLES...ARE IN GOOD AGREEMENT THROUGH MUCH OF
THE LONG TERM WITH ONLY SOME MINOR DETAIL DIFFERENCES. THEREFORE...
WILL USE A BLEND OF AVAILABLE GUIDANCE FOR MUCH OF THE FORECAST.
POINTS OF INTEREST INCLUDE THE POTENTIAL FOR COLD TEMPERATURES AND
FROST FOR THURSDAY NIGHT INTO FRIDAY AND A COLD FRONT BRINGING
RAIN TO THE REGION SUNDAY INTO MONDAY.
WEDNESDAY AND THURSDAY...A BROAD UPPER TROUGH OVER THE NORTHEAST US
WILL SLOWLY MOVE OFFSHORE DURING THIS TIME. HIGH PRESSURE BUILDS
OVER SOUTHERN NEW ENGLAND BRINGING AND SLIGHTLY COOLER THAN NORMAL
TEMPERATURES AND DRY WEATHER TO THE REGION.
FRIDAY...THIS IS THE COOLEST DAY BY FAR WITH LOW TEMPERATURES FRIDAY
MORNING EXPECTED TO BE IN THE LOW TO MID 30S ACROSS PORTIONS OF THE
FAR INTERIOR AND IN THE UPPER 40S ALONG THE COAST. HIGH
TEMPERATURES WILL THEN BE A GOOD 10 TO 15 DEGREES BELOW NORMAL.
OTHER THAN THE TEMPERATURES...EXPECT A PLEASANT DAY WITH MOSTLY
CLEAR SKIES AS HIGH PRESSURE REMAINS OVER THE REGION.
SATURDAY THROUGH MONDAY...TEMPERATURES START TO MODERATE THROUGH THE
WEEKEND WITH WARMING SOUTHERLY SURFACE WINDS IN PLACE AHEAD OF A
COLD FRONT STEMMING FROM AN INTENSIFYING AREA OF LOW PRESSURE JUST
NORTH OF THE GREAT LAKES. THIS IS ASSOCIATED WITH A DEEP UPPER
LEVEL TROUGH OVER THE GREAT LAKES THAT WILL SLOWLY MOVE OVER
SOUTHERN NEW ENGLAND AND THEN OFFSHORE BY EARLY NEXT WEEK. EXPECT
SOME RAINFALL AHEAD OF THE COLD FRONT SUNDAY AND MONDAY. MODELS
ARE INDICATING SOME INSTABILITY SO THUNDER IS A POSSIBILITY AT
THIS POINT...BUT WILL LEAVE IT OUT SINCE MUCH COULD CHANGE IN THE
NEXT WEEK.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT-TERM FORECAST /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE.
TODAY...VRB WINDS WITH SEA-BREEZES ALONG THE SHORES. SCT-BKN 4-5
KFT DECKS LINGERING INTO EVENING.
TONIGHT...SHRA AFTER MIDNIGHT FOR W-TERMINALS DISSIPATING AS THEY
SPREAD E. WILL HOLD WITH LOW-END VFR CIGS WITH ONLY PERHAPS MVFR
FOR S-COASTAL TERMINALS. WINDS TURNING S.
TUESDAY...SHRA DISSIPATING AS SW-WINDS SHIFT OUT OF THE W-NW
WITH THE COLD FRONTAL PASSAGE. LOW-END VFR CIGS OVERALL WITH
PERHAPS SOME MVFR LINGERING ALONG THE S-COAST DURING THE MORNING.
TUESDAY NIGHT...VFR WITH WINDS BECOMING VRB. DENSE FOG POSSIBLE
FOR THE W-INTERIOR TERMINALS...ESPECIALLY THE CT-VALLEY FROM KBAF
NORTHWARD.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA-BREEZE ONSHORE WILL
LEND TO E-FLOW INTO EVENING...TURNING SE LATE.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...WEDNESDAY THROUGH FRIDAY.
WEDNESDAY THROUGH FRIDAY...HIGH CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT-TERM FORECAST /THROUGH TUESDAY NIGHT/...MODERATE CONFIDENCE.
WHILE THE WEATHER WILL BE FOR THE MOST PART QUIET WITH A DRY COLD
FRONTAL PASSAGE EXPECTED FOR LATE TUESDAY /WINDS OUT OF THE SW
SHIFTING OUT OF THE W-NW/...MAIN CONCERN IS THE ANTICIPATED SWELL
AND WAVES ASSOCIATED WITH EDOUARD.
WITH EDOUARD FAR REMOVED FROM THE COAST...AND OVERDONE FORECAST
MODELS WITH REGARDS TO SEAS...HAVE HELD WAVE HEIGHTS NO GREATER
THAN 5 FEET. HAVE ALSO HELD OFF ON THE ISSUANCE OF SMALL-CRAFT
ADVISORIES FOR SEAS. WILL RE-EVALUATE AS WE GET CLOSER TO THE
POTENTIAL FOR SIGNIFICANT WAVE HEIGHTS AND POSSIBLE RIP CURRENT
THREAT BEGINNING TUESDAY NIGHT TOWARDS WEDNESDAY.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
WEDNESDAY THROUGH FRIDAY...LINGERING SWELL FROM HURRICANE EDOUARD
/KEEPS WELL OUT TO SEA/ KEEPS SEAS IN THE 5 TO 6 FOOT RANGE ON THE
OUTER WATERS. WINDS WILL REMAIN FAIRLY LIGHT AND VARIABLE THROUGH
THURSDAY WITH HIGH PRESSURE OVER THE WATERS. NORTHEASTERLY WINDS
MAY GUST TO NEAR 25 KTS FRIDAY AFTERNOON AS THE HIGH SHIFTS EASTWARD.
LATE FRIDAY NIGHT INTO SATURDAY...QUIET BOATING WEATHER EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RLG/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...RLG
AVIATION...RLG/SIPPRELL
MARINE...RLG/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
353 PM EDT MON SEP 15 2014
.SHORT TERM (REST OF TODAY-TUESDAY)...
DRIER AIR HAS HELD OVER MUCH OF WEST CENTRAL AND SOUTHWEST FLORIDA
TODAY...THOUGH RADAR SHOWS SOME SHOWERS DEVELOPING SEA BREEZE AND
OUTFLOW BOUNDARIES THIS AFTERNOON. FORECAST HAS BEEN TRENDING
DRIER...THOUGH EARLIER RUNS OF THE HRRR HAVE BEEN DOING QUITE WELL
TODAY. THE GENERAL TREND OF OFFSHORE ACTIVITY TRANSITIONING TO
ISOLATED TO SCATTERED CONVECTION ON SHORE IS BEGINNING TO OCCUR.
GUIDANCE WAS TRENDING TOWARDS HAVING THE CONVECTION SPREAD SOUTH
ALONG THE SEA BREEZE THROUGH THE TAMPA BAY AREA INTO SOUTHWEST
FLORIDA. WHILE THE DRIER AIR HAS DEFINITELY BEEN WORKING AGAINST
THIS...THE LACK OF CLOUDS FOR MUCH OF THE DAY HAS ALLOWED THE AREA
TO WARM SUFFICIENTLY TO SUPPORT SHOWERS AND POSSIBLY AN ISOLATED
THUNDERSTORM.
THE FRONTAL BOUNDARY NEARING THE NATURE COAST WILL ALLOW
CONVECTION TO REMAIN ACTIVE AROUND THE BIG BEND OF FLORIDA INTO
TUESDAY. FOR THE REST OF THE AREA...ACTIVITY SHOULD PUSH OFFSHORE
BY MIDNIGHT THOUGH SOME SHOWERS COULD LINGER AROUND THE COASTAL
AREAS AND IN PORTIONS OF SOUTHWEST FLORIDA UNTIL LATE EVENING.
GENERAL TRENDS AFTER SUNSET SHOULD BE FOR DIMINISHING CONVECTION
OVER LAND. AROUND SUNRISE...RAIN CHANCES WILL BEGIN TO INCREASE
FROM THE NATURE COAST SOUTHWARD THROUGHOUT THE DAY ON TUESDAY. THE
MAJORITY OF TUESDAY/S ACTIVITY WILL BE CENTERED ALONG AND AHEAD
THE FRONTAL BOUNDARY NEARING THE NATURE COAST AND IN THE INTERIOR
ONCE THE AFTERNOON CONVECTION AND SEA BREEZE GETS GOING.
TEMPERATURES ALONG THE NATURE COAST WILL BE HELD IN THE MID TO
UPPER 80S THANKS TO ADDITIONAL CLOUD COVER AROUND THE FRONT. WOULD
NOT BE SURPRISED IF SOME AREAS STRUGGLED TO REACH 85 IN LEVY
COUNTY ON TUESDAY FOR HIGHS. REST OF THE AREA SHOULD SEE SOME
MORNING CLOUDS AND BE ABLE TO WARM IN THE UPPER 80S OR LOWER 90S.
POPS WILL TREND UP AS MOISTURE INCREASES AHEAD OF THE FRONT/S
ARRIVAL. THE HRRR AND LOCAL CAM GUIDANCE WERE GIVEN HEAVY WEIGHT
IN THE SHORT TERM.
.LONG TERM (TUESDAY NIGHT-SUNDAY)...
A FRONTAL BOUNDARY WILL BE PUSHING THROUGH THE STATE AT THE START
OF THE LONG TERM PERIOD. ENSEMBLE GUIDANCE CONTINUES TO SUGGEST
THAT THE BOUNDARY WILL PUSH THROUGH THE STATE AND REACH SOUTH
FLORIDA BY FRIDAY. AHEAD OF THE SYSTEM AMPLE MOISTURE WILL BE IN
PLACE (PWATS AOA 2 INCHES). MAINTAINED LIKELY POPS ACROSS THE CWA
WEDNESDAY WHILE UNDERCUTTING MOS TEMPS SLIGHTLY AS RAIN AND CLOUD
COVER SHOULD KEEP TEMPS LOWER. BEHIND THE BOUNDARY...SOMEWHAT
DRIER AIR WILL MOVE INTO THE REGION THU AND FRI AS PWATS ARE
FORECAST TO DROP BETWEEN 1.25-1.5 FROM THE BAY AREA NORTH WITH
SLIGHTLY HIGHER VALUES IN SW FLORIDA. STILL ENOUGH TO MAINTAIN
ISOLATED TO LOW END SCATTERED PRECIP COVERAGE DURING THE AFTN AND
EVENINGS...HIGHEST IN SW FL.
BY LATE WEEK AND INTO THE WEEKEND SEASONAL RAIN CHANCES EXPECTED
WITH SCT AFTN SHOWERS AND STORMS POSSIBLE. TEMPERATURES WILL STILL
FEEL LIKE SUMMER DESPITE THE QUICKLY APPROACHING AUTUMNAL EQUINOX
NEXT TUESDAY.
&&
.AVIATION...
VFR EXPECTED THROUGH THE PERIOD. BRIEF SHOWERS...AND POSSIBLY A
THUNDERSTORM...ARE POSSIBLE THIS EVENING AND AGAIN TOMORROW. WINDS
SHOULD REMAIN 10 KNOTS OR BELOW...EXCEPT FOR VARIABLE GUSTINESS
AROUND CONVECTION.
&&
.MARINE...
SURFACE RIDGE AXIS IS SLIPPING SOUTHWARD ACROSS THE WATERS AS A WEAK
FRONTAL BOUNDARY MOVES INTO THE SOUTHEASTERN STATES. THIS HAS
RESULTED IN LIGHTER WINDS WITH AN EASTERLY COMPONENT SOUTH OF THE
RIDGE AXIS AND A WESTERLY COMPONENT TO THE NORTH. THE RIDGE IS
FORECAST TO CONTINUE MOVING SOUTHWARD SLOWLY...LIKELY REACHING A
POSITION SOUTH OF OUR WATERS BY MID-WEEK. THIS COMBINED WITH THE
WEAK FRONTAL BOUNDARY MOVING INTO THE NORTHEAST GULF COULD RESULT IN
A LONG FETCH OF WESTERLY WINDS ACROSS THE GULF. MODELS DO NOT
SUPPORT MUCH MORE THAN ABOUT 10 KNOTS OF WIND AT THIS TIME SO SEAS
ARE EXPECTED TO STAY 2 FEET OR LESS WITH SOME SWELL COMPONENT
LIKELY. THE MAIN CONCERN WILL BE THE POTENTIAL BAND OF SHOWERS AND
THUNDERSTORMS WITH THE BOUNDARY WHICH WOULD IMPACT MOST OF OUR
WATERS DURING TUESDAY AND WEDNESDAY.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AS A FRONT MOVES ACROSS THE AREA THIS
WEEK...BRINGING INCREASED MOISTURE AND WETTING RAINS OVER THE
NEXT FEW DAYS. SOME MORNING GROUND IS POSSIBLE OVER THE NEXT FEW
MORNINGS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 76 89 75 87 / 20 60 40 60
FMY 75 92 75 87 / 30 60 40 60
GIF 74 91 73 88 / 30 70 40 60
SRQ 75 88 74 85 / 20 50 40 60
BKV 72 89 69 88 / 20 60 50 60
SPG 79 88 77 85 / 20 60 40 60
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/FIRE WEATHER...02/GARCIA
MARINE...25/DAVIS
LONG TERM...11/MCKAUGHAN
DECISION SUPPORT...05/CARLISLE
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
632 PM EDT MON SEP 15 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 341 PM EDT MON SEP 15 2014
A WEAK LOW PRESSURE SYSTEM MOVING THROUGH THE AREA TODAY AND TONIGHT
WILL CONTINUE TO BRING SOME SHOWERS AND PERHAPS A FEW THUNDERSTORMS
TO THE REGION BEFORE PRECIPITATION IS AGAIN SHUT OFF BY HIGH
PRESSURE WHICH WILL DOMINATE THE REGION THROUGH THE REMAINDER OF THE
WEEK. THE NEXT FRONTAL SYSTEM WILL NOT IMPACT THE AREA UNTIL THE
LATTER PORTION OF THE WEEKEND. TEMPERATURES SHOULD GRADUALLY WARM
BUT REMAIN BELOW NORMAL THROUGH MUCH OF THE WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 341 PM EDT MON SEP 15 2014
CURRENT RADAR TRENDS AND HRRR MODEL SUGGEST SHOWERS WILL REMAIN A
THREAT AT LEAST THROUGH MIDNIGHT...AND HAVE GENERALLY FOLLOWED THIS
LINE OF THINKING...GRADUALLY TAPERING OFF POPS AND ENDING THEM BY
06Z. WILL CARRY ONLY SHOWERS FROM 00Z ONWARD AS INSTABILITY SHOULD
BE WANING QUICKLY.
ON TEMPS...UPSTREAM MINS SUGGEST UPPER 40S TO LOW 50S IS A GOOD BET
TONIGHT AND THIS IS IN LINE WITH CONSENSUS NUMBERS WITH A FEW MINOR
TWEAKS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 341 PM EDT MON SEP 15 2014
HIGH PRESSURE WILL BE IN CONTROL THROUGHOUT THE SHORT TERM AND THUS
TEMPERATURES ARE THE ONLY SIGNIFICANT FORECAST ISSUE.
EXPECT SKIES TO BE MOSTLY CLEAR THROUGHOUT...HOWEVER MOS APPEARS A
BIT AGGRESSIVE ON MAX TEMPS COMPARED TO NUMBERS UPSTREAM AND LOW
LEVEL THICKNESSES. HAVE GENERALLY SPLIT THE DIFFERENCE BETWEEN COOL
MODEL CONSENSUS NUMBERS AND WARMER MOS ON HIGHS. MOS APPEARS MUCH
BETTER ON LOWS ESPECIALLY GIVEN NEAR IDEAL RADIATIONAL COOLING
CONDITIONS EACH NIGHT...AND WITH A FEW MINOR TWEAKS HAVE LARGELY
GONE WITH MOS ON MINS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 230 PM EDT MON SEP 15 2014
THE EXTENDED WILL FEATURE A WARMING TREND AS AN UPPER RIDGE BUILDS
ACROSS THE AREA LATE WEEK INTO THE EARLY WEEKEND. MODELS AND
ENSEMBLES IN GOOD AGREEMENT ON BRINGING A COLD FRONT NORTHWEST TO
SOUTHEAST ACROSS THE AREA FOLLOWED BY A SHARP UPPER TROUGH MONDAY
EVENING. WITH THE SYNOPTIC FEATURES ACCOMPANIED BY DEEPER
MOISTURE...SHOWERS AND POSSIBLY THUNDERSTORMS LOOK LIKE A GOOD BET
SATURDAY NIGHT AND SUNDAY PER SIMILAR MODEL QPF TIMING. AFTERNOON
TEMPERATURES SHOULD BE BACK UP IN THE 70S WITH LOWER 80S POSSIBLE
SATURDAY.
&&
.AVIATION /DISCUSSION FOR THE 160000Z TAFS/...
ISSUED AT 632 PM EDT MON SEP 15 2014
AREA OF RAIN/EMBEDDED CONVECTION CURRENTLY PUSHING THROUGH CENTRAL
INDIANA...WITH THE CONVECTION AFFECTING KHUF/KBMG. MOST THE
CONVECTION APPEARS TO BE TIED TO AN UPPER WAVE...WHICH SHOULD PUSH
OFF TO THE EAST OF THE TAF SITES BY ISSUANCE TIME. SURFACE COLD
FRONT LAGGING BEHIND THE UPPER WAVE EXPECTED TO MOVE SOUTHEAST
ACROSS THE TAF SITES THROUGH ABOUT 160400Z...SO THINK THERE WILL BE
SOME SHOWER ACTIVITY FROM TIME TO TIME UNTIL THEN. FAIRLY WIDESPREAD
IFR CEILINGS ON THE COLD SIDE OF THE FRONT SHOULD ADVECT INTO THE
AREA AFTER FRONTAL PASSAGE. SHORT TERM MODELS SUGGEST THE IFR
CEILINGS MAY HOLD MOST OF THE NIGHT...POSSIBLY LIFTING INTO AN MVFR
DECK AT KLAF TOWARDS SUNRISE TUESDAY.
SURFACE WINDS STILL A LITTLE CHAOTIC DUE TO CONVECTION...BUT SHOULD
SETTLE TO 210-240 AT 6-8 KTS VEERING AROUND TO 330-350 WITH FRONTAL
PASSAGE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...MK
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
607 PM EDT MON SEP 15 2014
.SYNOPSIS...
ISSUED AT 606 PM EDT MON SEP 15 2014
A COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA THIS
EVENING...CONTINUING RAIN SHOWERS THROUGH EARLY TONIGHT. DRY CONDITIONS
WILL RETURN OVERNIGHT BEHIND THE FRONT...WITH A REINFORCING PUSH
OF COOL AIR RESULTING IN CONTINUED BELOW NORMAL TEMPERATURES
THROUGH MID WEEK. LOW TEMPERATURES TONIGHT WILL RANGE FROM THE MID
40S TO AROUND 50 WITH HIGH TEMPERATURES ON TUESDAY IN THE LOW TO
MID 60S.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM EDT MON SEP 15 2014
AFTERNOON WATER VAPOR IMAGERY SHOWS WELL DEFINED SHORTWAVE CURRENTLY
APPROACHING THE SOUTHERN GREAT LAKES...EMBEDDED IN BROAD TROUGHING
OVER EASTERN NOAM. FOCUSED PV CENTROID...RESPONSIBLE FOR RAIN
CURRENTLY OVER SOUTHERN WISCONSIN...WILL SWING JUST NORTH OF OUR CWA
LATER THIS EVENING AND ASSOCIATED QG FORCING WILL LEAD TO AN
EXPANSION OF RAIN SHOWERS ACROSS OUR AREA. ELEVATED FRONTAL ZONE
WILL BE SUPPORTED BY DECENT MIDLEVEL HEIGHT FALLS BUT ALSO RIGHT
ENTRANCE DYNAMICS OF ATTENDANT 100+ KT UPPER LEVEL JET STREAK. I-80
CORRIDOR HAS BEEN LARGELY SPLIT SO FAR TODAY BY BETTER 300K
ISENTROPIC ASCENT TO THE SOUTH AND CVA FORCING TO THE NORTH. SOME
CONCERN THAT WILL CONTINUE TO BE THE CASE THROUGH THE EVENING BUT
ALL OF THE LATEST HI-RES GUIDANCE INDICATES THIS AREA WILL FILL IN
BY THIS EVENING AS MID/UPPER LEVEL WAVE AND ASSOCIATED 700-600MB
FGEN APPROACH. 16Z RUN OF THE HRRR FINALLY SEEMED TO GET A DECENT
HANDLE ON EVOLVING PRECIP AND SUGGESTS LINE OF SHOWERS CURRENTLY IN
NORTHEAST ILLINOIS WILL EXPAND EASTWARD AS TROUGH AXIS APPROACHES.
BETTER MOISTURE IS BEING ROBBED BY CONVECTION TO OUR SOUTH THOUGH
AND EXPECT JUST OCCASIONAL LIGHT RAIN SHOWERS THROUGH THE EVENING.
PRECIP SHOULD EXIT QUICKLY WITH DRY CONDITIONS THEN PERSISTING
THROUGH TOMORROW.
DESPITE EXITING PRECIP...SKIES WILL LIKELY NOT BEGIN TO CLEAR UNTIL
LATE TOMORROW MORNING GIVEN NOCTURNAL BOUNDARY LAYER COOLING WITH
LINGERING LOW LEVEL MOISTURE AND A DEVELOPING INVERSION. SOME
POTENTIAL FOR PATCHY FOG BUT FORECAST SOUNDINGS...AND PERSISTENT
GRADIENT WIND...SUGGEST BETTER POTENTIAL FOR LOW STRATUS. ADDED
PATCHY FOG MENTION TO OUR WESTERN COUNTIES BASED ON MORE SHALLOW
MOISTURE AND LIGHTER WINDS BUT WILL HOLD OFF IN THE EAST FOR NOW AND
MONITOR TRENDS OVERNIGHT. THESE CONDITIONS SHOULD ALSO KEEP A BIT OF
A FLOOR ON OVERNIGHT LOWS. EXPECTING VALUES GENERALLY IN THE MID TO
UPPER 40S BASED ON LATEST RAW AND MOS GUIDANCE. APPROACHING AIRMASS
IS NOT MUCH COLDER THAN WHAT IS CURRENTLY IN PLACE AND HIGH TEMPS
TOMORROW SHOULD BE VERY CLOSE TO TODAY`S VALUES. DID INCREASE SKY
COVER THOUGH...BASED ON EXPECTATION FOR A SLOW EROSION OF MORNING
STRATOCU.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM EDT MON SEP 15 2014
PATTERN MID-LATE WEEK WILL BE CHARACTERIZED BY COOL NORTHWEST FLOW
ALOFT AND RIDGING AT THE SFC. THERE WILL LIKELY BE A FEW WEAK WAVES
EMBEDDED IN THIS FLOW. HOWEVER...ANY SUCH FEATURE WILL STRUGGLE TO
PRODUCE ANYTHING MORE THAN SCATTERED CLOUDS GIVEN DEARTH OF MOISTURE
AND STABLE MID LEVELS.
BRIEF RELAXATION OF EASTERN CONUS TROUGHING WITH WINDS VEERING
SOUTHWESTERLY SHOULD ALLOW HIGHS TO WARM NEAR OR JUST ABOVE SEASONAL
AVERAGES BY SATURDAY. ASSOCIATED WARM ADVECTION PRECIP ALONG A
DEVELOPING WARM FRONT MAY CLIP FAR NORTHERN ZONES LATER FRIDAY
NIGHT-SATURDAY WHERE LOW CHC POPS WERE RETAINED.
MODELS HAVE REMAINED CONSISTENT IN TRANSLATING AN UPPER TROUGH/CDFNT
EAST THROUGH THE AREA SATURDAY NIGHT INTO SUNDAY MORNING. POSSIBLE
ABSORPTION OF HURRICANE ODILE REMNANT MOISTURE INTO THIS FEATURE MAY
AID IN BRINGING SOME HEAVIER RAINFALL/ISO THUNDER TO THE AREA DURING
THIS TIME. OTHERWISE...DRIER/COOLER AIR EXPECTED IN WAKE OF THIS
SYSTEM LATER SUNDAY-MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON SEP 15 2014
SHORTWAVE TROUGH IS CURRENTLY APPROACHING THE AREA AND EXPECT
SHOWERS TO GRADUALLY EXPAND ACROSS NORTHERN INDIANA BY LATE THIS
AFTERNOON. UPSTREAM OBSERVATIONS SUGGEST IT WILL TAKE SOME TIME
FOR BETTER LOW LEVEL MOISTURE...AND MVFR CONDITIONS...TO DEVELOP.
PUSHED BACK THE TIMING A BIT BUT FORECAST SOUNDINGS STILL SUPPORT
FUEL ALTERNATE CONDITIONS AS THE RAIN MOVES THROUGH THIS EVENING.
PATCHY FOG WILL ALSO BE POSSIBLE LATE TONIGHT GIVEN RESIDUAL LOW
LEVEL MOISTURE...DEVELOPING INVERSION...AND LIGHT SURFACE WINDS.
CONFIDENCE IS STILL LOW HOWEVER AND A STRATUS DECK CANNOT BE
RULED OUT. INTRODUCED MVFR CONDITIONS FOR KFWA BASED ON MOS
GUIDANCE AND BETTER MOISTURE SEEN IN FORECAST SOUNDINGS BUT LEFT
KSBN VFR FOR NOW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...CEO
SHORT TERM...AGD
LONG TERM...STEINWEDEL
AVIATION...AGD
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
433 PM EDT MON SEP 15 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 341 PM EDT MON SEP 15 2014
A WEAK LOW PRESSURE SYSTEM MOVING THROUGH THE AREA TODAY AND TONIGHT
WILL CONTINUE TO BRING SOME SHOWERS AND PERHAPS A FEW THUNDERSTORMS
TO THE REGION BEFORE PRECIPITATION IS AGAIN SHUT OFF BY HIGH
PRESSURE WHICH WILL DOMINATE THE REGION THROUGH THE REMAINDER OF THE
WEEK. THE NEXT FRONTAL SYSTEM WILL NOT IMPACT THE AREA UNTIL THE
LATTER PORTION OF THE WEEKEND. TEMPERATURES SHOULD GRADUALLY WARM
BUT REMAIN BELOW NORMAL THROUGH MUCH OF THE WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 341 PM EDT MON SEP 15 2014
CURRENT RADAR TRENDS AND HRRR MODEL SUGGEST SHOWERS WILL REMAIN A
THREAT AT LEAST THROUGH MIDNIGHT...AND HAVE GENERALLY FOLLOWED THIS
LINE OF THINKING...GRADUALLY TAPERING OFF POPS AND ENDING THEM BY
06Z. WILL CARRY ONLY SHOWERS FROM 00Z ONWARD AS INSTABILITY SHOULD
BE WANING QUICKLY.
ON TEMPS...UPSTREAM MINS SUGGEST UPPER 40S TO LOW 50S IS A GOOD BET
TONIGHT AND THIS IS IN LINE WITH CONSENSUS NUMBERS WITH A FEW MINOR
TWEAKS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 341 PM EDT MON SEP 15 2014
HIGH PRESSURE WILL BE IN CONTROL THROUGHOUT THE SHORT TERM AND THUS
TEMPERATURES ARE THE ONLY SIGNIFICANT FORECAST ISSUE.
EXPECT SKIES TO BE MOSTLY CLEAR THROUGHOUT...HOWEVER MOS APPEARS A
BIT AGGRESSIVE ON MAX TEMPS COMPARED TO NUMBERS UPSTREAM AND LOW
LEVEL THICKNESSES. HAVE GENERALLY SPLIT THE DIFFERENCE BETWEEN COOL
MODEL CONSENSUS NUMBERS AND WARMER MOS ON HIGHS. MOS APPEARS MUCH
BETTER ON LOWS ESPECIALLY GIVEN NEAR IDEAL RADIATIONAL COOLING
CONDITIONS EACH NIGHT...AND WITH A FEW MINOR TWEAKS HAVE LARGELY
GONE WITH MOS ON MINS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 230 PM EDT MON SEP 15 2014
THE EXTENDED WILL FEATURE A WARMING TREND AS AN UPPER RIDGE BUILDS
ACROSS THE AREA LATE WEEK INTO THE EARLY WEEKEND. MODELS AND
ENSEMBLES IN GOOD AGREEMENT ON BRINGING A COLD FRONT NORTHWEST TO
SOUTHEAST ACROSS THE AREA FOLLOWED BY A SHARP UPPER TROUGH MONDAY
EVENING. WITH THE SYNOPTIC FEATURES ACCOMPANIED BY DEEPER
MOISTURE...SHOWERS AND POSSIBLY THUNDERSTORMS LOOK LIKE A GOOD BET
SATURDAY NIGHT AND SUNDAY PER SIMILAR MODEL QPF TIMING. AFTERNOON
TEMPERATURES SHOULD BE BACK UP IN THE 70S WITH LOWER 80S POSSIBLE
SATURDAY.
&&
.AVIATION /DISCUSSION FOR THE 152100Z KIND TAF UPDATE/...
ISSUED AT 433 PM EDT MON SEP 15 2014
INITIAL BAND OF RAIN/EMBEDDED THUNDER IS CURRENTLY PUSHING OFF TO
THE SOUTHEAST OF KIND. ANOTHER CLUSTER OF EMBEDDED CONVECTION IS
PUSHING EAST THROUGH EAST CENTRAL ILLINOIS. BASED ON ITS
MOVEMENT...APPEARS THE EMBEDDED CONVECTION WILL PASS OFF TO THE
SOUTH OF KIND AROUND 152200Z-152300Z...BUT IT WILL BE CLOSE. FOR
NOW...WILL GO WITH A PERIOD OF SHOWERS AROUND THIS TIME...AND
MONITOR THE TRENDS.
SURFACE WIND GUSTS MAY BE DUE TO A WAKE LOW ASSOCIATED WITH THE
CONVECTION MOVING OFF TO THE SOUTHEAST. THESE GUSTS SHOULD BE
TEMPORARY.
PREVIOUS DISCUSSION FOLLOWS.
A WEAK FRONT WILL DROP SOUTHEAST ACROSS THE TERMINALS AFTERNOON 00Z.
SHOWERS AND POSSIBLY THUNDERSTORMS WILL BE INCREASING THIS AFTERNOON
AHEAD OF THIS SYSTEM...AND A FEW EVENING SHOWERS COULD HANG AROUND
THIS EVENING BEHIND THE FRONT. THEN...SHOULD SEE SOME CLEARING
OVERNIGHT. THIS COULD ALLOW SOME FOG TO FORM. HOWEVER...NORTH WINDS
BEHIND THE FRONT MAY STAY UP ENOUGH TO KEEP THE FOG NO WORSE THAN
MVFR. HOWEVER...CONFIDENCE IS LOW AT THIS TIME. WINDS AHEAD OF THE
FRONT WILL BE SOUTH AND SOUTHWEST NEAR 10 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...MK
AVIATION...MK/JAS
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
341 PM EDT MON SEP 15 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
ISSUED AT 341 PM EDT MON SEP 15 2014
A WEAK LOW PRESSURE SYSTEM MOVING THROUGH THE AREA TODAY AND TONIGHT
WILL CONTINUE TO BRING SOME SHOWERS AND PERHAPS A FEW THUNDERSTORMS
TO THE REGION BEFORE PRECIPITATION IS AGAIN SHUT OFF BY HIGH
PRESSURE WHICH WILL DOMINATE THE REGION THROUGH THE REMAINDER OF THE
WEEK. THE NEXT FRONTAL SYSTEM WILL NOT IMPACT THE AREA UNTIL THE
LATTER PORTION OF THE WEEKEND. TEMPERATURES SHOULD GRADUALLY WARM
BUT REMAIN BELOW NORMAL THROUGH MUCH OF THE WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 341 PM EDT MON SEP 15 2014
CURRENT RADAR TRENDS AND HRRR MODEL SUGGEST SHOWERS WILL REMAIN A
THREAT AT LEAST THROUGH MIDNIGHT...AND HAVE GENERALLY FOLLOWED THIS
LINE OF THINKING...GRADUALLY TAPERING OFF POPS AND ENDING THEM BY
06Z. WILL CARRY ONLY SHOWERS FROM 00Z ONWARD AS INSTABILITY SHOULD
BE WANING QUICKLY.
ON TEMPS...UPSTREAM MINS SUGGEST UPPER 40S TO LOW 50S IS A GOOD BET
TONIGHT AND THIS IS IN LINE WITH CONSENSUS NUMBERS WITH A FEW MINOR
TWEAKS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 341 PM EDT MON SEP 15 2014
HIGH PRESSURE WILL BE IN CONTROL THROUGHOUT THE SHORT TERM AND THUS
TEMPERATURES ARE THE ONLY SIGNIFICANT FORECAST ISSUE.
EXPECT SKIES TO BE MOSTLY CLEAR THROUGHOUT...HOWEVER MOS APPEARS A
BIT AGGRESSIVE ON MAX TEMPS COMPARED TO NUMBERS UPSTREAM AND LOW
LEVEL THICKNESSES. HAVE GENERALLY SPLIT THE DIFFERENCE BETWEEN COOL
MODEL CONSENSUS NUMBERS AND WARMER MOS ON HIGHS. MOS APPEARS MUCH
BETTER ON LOWS ESPECIALLY GIVEN NEAR IDEAL RADIATIONAL COOLING
CONDITIONS EACH NIGHT...AND WITH A FEW MINOR TWEAKS HAVE LARGELY
GONE WITH MOS ON MINS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 230 PM EDT MON SEP 15 2014
THE EXTENDED WILL FEATURE A WARMING TREND AS AN UPPER RIDGE BUILDS
ACROSS THE AREA LATE WEEK INTO THE EARLY WEEKEND. MODELS AND
ENSEMBLES IN GOOD AGREEMENT ON BRINGING A COLD FRONT NORTHWEST TO
SOUTHEAST ACROSS THE AREA FOLLOWED BY A SHARP UPPER TROUGH MONDAY
EVENING. WITH THE SYNOPTIC FEATURES ACCOMPANIED BY DEEPER
MOISTURE...SHOWERS AND POSSIBLY THUNDERSTORMS LOOK LIKE A GOOD BET
SATURDAY NIGHT AND SUNDAY PER SIMILAR MODEL QPF TIMING. AFTERNOON
TEMPERATURES SHOULD BE BACK UP IN THE 70S WITH LOWER 80S POSSIBLE
SATURDAY.
&&
.AVIATION /DISCUSSION FOR THE 151800Z TAF ISSUANCE/...
ISSUED AT 1215 PM EDT MON SEP 15 2014
A WEAK FRONT WILL DROP SOUTHEAST ACROSS THE TERMINALS AFTERNOON 00Z.
SHOWERS AND POSSIBLY THUNDERSTORMS WILL BE INCREASING THIS AFTERNOON
AHEAD OF THIS SYSTEM...AND A FEW EVENING SHOWERS COULD HANG AROUND
THIS EVENING BEHIND THE FRONT. THEN...SHOULD SEE SOME CLEARING
OVERNIGHT. THIS COULD ALLOW SOME FOG TO FORM. HOWEVER...NORTH WINDS
BEHIND THE FRONT MAY STAY UP ENOUGH TO KEEP THE FOG NO WORSE THAN
MVFR. HOWEVER...CONFIDENCE IS LOW AT THIS TIME. WINDS AHEAD OF THE
FRONT WILL BE SOUTH AND SOUTHWEST NEAR 10 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...MK
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
336 PM EDT MON SEP 15 2014
.SYNOPSIS...
ISSUED AT 1046 AM EDT MON SEP 15 2014
A COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA TODAY...BRINGING
RAIN SHOWERS AND ISOLATED THUNDERSTORMS TO THE REGION. DRY
CONDITIONS WILL RETURN LATER THIS EVENING BEHIND THE FRONT...WITH
A REINFORCING PUSH OF COOL AIR RESULTING IN CONTINUED BELOW NORMAL
TEMPERATURES THROUGH MID WEEK. HIGH TEMPERATURES THIS AFTERNOON
WILL REACH INTO THE 60S. LOW TEMPERATURES TONIGHT WILL RANGE FROM
THE MID 40S TO AROUND 50.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM EDT MON SEP 15 2014
AFTERNOON WATER VAPOR IMAGERY SHOWS WELL DEFINED SHORTWAVE CURRENTLY
APPROACHING THE SOUTHERN GREAT LAKES...EMBEDDED IN BROAD TROUGHING
OVER EASTERN NOAM. FOCUSED PV CENTROID...RESPONSIBLE FOR RAIN
CURRENTLY OVER SOUTHERN WISCONSIN...WILL SWING JUST NORTH OF OUR CWA
LATER THIS EVENING AND ASSOCIATED QG FORCING WILL LEAD TO AN
EXPANSION OF RAIN SHOWERS ACROSS OUR AREA. ELEVATED FRONTAL ZONE
WILL BE SUPPORTED BY DECENT MIDLEVEL HEIGHT FALLS BUT ALSO RIGHT
ENTRANCE DYNAMICS OF ATTENDANT 100+ KT UPPER LEVEL JET STREAK. I-80
CORRIDOR HAS BEEN LARGELY SPLIT SO FAR TODAY BY BETTER 300K
ISENTROPIC ASCENT TO THE SOUTH AND CVA FORCING TO THE NORTH. SOME
CONCERN THAT WILL CONTINUE TO BE THE CASE THROUGH THE EVENING BUT
ALL OF THE LATEST HI-RES GUIDANCE INDICATES THIS AREA WILL FILL IN
BY THIS EVENING AS MID/UPPER LEVEL WAVE AND ASSOCIATED 700-600MB
FGEN APPROACH. 16Z RUN OF THE HRRR FINALLY SEEMED TO GET A DECENT
HANDLE ON EVOLVING PRECIP AND SUGGESTS LINE OF SHOWERS CURRENTLY IN
NORTHEAST ILLINOIS WILL EXPAND EASTWARD AS TROUGH AXIS APPROACHES.
BETTER MOISTURE IS BEING ROBBED BY CONVECTION TO OUR SOUTH THOUGH
AND EXPECT JUST OCCASIONAL LIGHT RAIN SHOWERS THROUGH THE EVENING.
PRECIP SHOULD EXIT QUICKLY WITH DRY CONDITIONS THEN PERSISTING
THROUGH TOMORROW.
DESPITE EXITING PRECIP...SKIES WILL LIKELY NOT BEGIN TO CLEAR UNTIL
LATE TOMORROW MORNING GIVEN NOCTURNAL BOUNDARY LAYER COOLING WITH
LINGERING LOW LEVEL MOISTURE AND A DEVELOPING INVERSION. SOME
POTENTIAL FOR PATCHY FOG BUT FORECAST SOUNDINGS...AND PERSISTENT
GRADIENT WIND...SUGGEST BETTER POTENTIAL FOR LOW STRATUS. ADDED
PATCHY FOG MENTION TO OUR WESTERN COUNTIES BASED ON MORE SHALLOW
MOISTURE AND LIGHTER WINDS BUT WILL HOLD OFF IN THE EAST FOR NOW AND
MONITOR TRENDS OVERNIGHT. THESE CONDITIONS SHOULD ALSO KEEP A BIT OF
A FLOOR ON OVERNIGHT LOWS. EXPECTING VALUES GENERALLY IN THE MID TO
UPPER 40S BASED ON LATEST RAW AND MOS GUIDANCE. APPROACHING AIRMASS
IS NOT MUCH COLDER THAN WHAT IS CURRENTLY IN PLACE AND HIGH TEMPS
TOMORROW SHOULD BE VERY CLOSE TO TODAY`S VALUES. DID INCREASE SKY
COVER THOUGH...BASED ON EXPECTATION FOR A SLOW EROSION OF MORNING
STRATOCU.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM EDT MON SEP 15 2014
PATTERN MID-LATE WEEK WILL BE CHARACTERIZED BY COOL NORTHWEST FLOW
ALOFT AND RIDGING AT THE SFC. THERE WILL LIKELY BE A FEW WEAK WAVES
EMBEDDED IN THIS FLOW. HOWEVER...ANY SUCH FEATURE WILL STRUGGLE TO
PRODUCE ANYTHING MORE THAN SCATTERED CLOUDS GIVEN DEARTH OF MOISTURE
AND STABLE MID LEVELS.
BRIEF RELAXATION OF EASTERN CONUS TROUGHING WITH WINDS VEERING
SOUTHWESTERLY SHOULD ALLOW HIGHS TO WARM NEAR OR JUST ABOVE SEASONAL
AVERAGES BY SATURDAY. ASSOCIATED WARM ADVECTION PRECIP ALONG A
DEVELOPING WARM FRONT MAY CLIP FAR NORTHERN ZONES LATER FRIDAY
NIGHT-SATURDAY WHERE LOW CHC POPS WERE RETAINED.
MODELS HAVE REMAINED CONSISTENT IN TRANSLATING AN UPPER TROUGH/CDFNT
EAST THROUGH THE AREA SATURDAY NIGHT INTO SUNDAY MORNING. POSSIBLE
ABSORPTION OF HURRICANE ODILE REMNANT MOISTURE INTO THIS FEATURE MAY
AID IN BRINGING SOME HEAVIER RAINFALL/ISO THUNDER TO THE AREA DURING
THIS TIME. OTHERWISE...DRIER/COOLER AIR EXPECTED IN WAKE OF THIS
SYSTEM LATER SUNDAY-MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON SEP 15 2014
SHORTWAVE TROUGH IS CURRENTLY APPROACHING THE AREA AND EXPECT
SHOWERS TO GRADUALLY EXPAND ACROSS NORTHERN INDIANA BY LATE THIS
AFTERNOON. UPSTREAM OBSERVATIONS SUGGEST IT WILL TAKE SOME TIME
FOR BETTER LOW LEVEL MOISTURE...AND MVFR CONDITIONS...TO DEVELOP.
PUSHED BACK THE TIMING A BIT BUT FORECAST SOUNDINGS STILL SUPPORT
FUEL ALTERNATE CONDITIONS AS THE RAIN MOVES THROUGH THIS EVENING.
PATCHY FOG WILL ALSO BE POSSIBLE LATE TONIGHT GIVEN RESIDUAL LOW
LEVEL MOISTURE...DEVELOPING INVERSION...AND LIGHT SURFACE WINDS.
CONFIDENCE IS STILL LOW HOWEVER AND A STRATUS DECK CANNOT BE
RULED OUT. INTRODUCED MVFR CONDITIONS FOR KFWA BASED ON MOS
GUIDANCE AND BETTER MOISTURE SEEN IN FORECAST SOUNDINGS BUT LEFT
KSBN VFR FOR NOW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MCD
SHORT TERM...AGD
LONG TERM...STEINWEDEL
AVIATION...AGD
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
145 PM EDT MON SEP 15 2014
.SYNOPSIS...
ISSUED AT 1046 AM EDT MON SEP 15 2014
A COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA TODAY...BRINGING
RAIN SHOWERS AND ISOLATED THUNDERSTORMS TO THE REGION. DRY
CONDITIONS WILL RETURN LATER THIS EVENING BEHIND THE FRONT...WITH
A REINFORCING PUSH OF COOL AIR RESULTING IN CONTINUED BELOW NORMAL
TEMPERATURES THROUGH MID WEEK. HIGH TEMPERATURES THIS AFTERNOON
WILL REACH INTO THE 60S. LOW TEMPERATURES TONIGHT WILL RANGE FROM
THE MID 40S TO AROUND 50.
&&
.UPDATE...
ISSUED AT 920 AM EDT MON SEP 15 2014
VERY STEEP MIDLEVEL LAPSE RATES...OVER 8 C/KM ON LATEST SPC/RAP
MESOANALYSIS...HAVE SUPPORTED A FEW ELEVATED THUNDERSTORMS AS
INITIAL SATURATION OCCURS. RAP FORECAST SOUNDINGS AND MUCAPE
FIELDS INDICATE THIS INSTABILITY WILL DECREASE THROUGH THE DAY BUT
SUGGEST LAPSE RATES WILL REMAIN JUST STEEP ENOUGH IN OUR SOUTHERN
COUNTIES TO ALLOW FOR A FEW ISOLATED THUNDERSTORMS ALONG ELEVATED
FRONTAL ZONE THROUGH THE EARLY AFTERNOON. CURRENTLY NUMEROUS
THUNDERSTORMS IN SOUTHERN IOWA AND WESTERN ILLINOIS. THIS ACTIVITY
IS ENTRENCHED IN THE BETTER THETA-E PLUME BUT SUSPECT A FEW
THUNDERSTORMS WILL CONTINUE TO CLIP OUR SOUTHWEST COUNTIES AT
LEAST. HAVE UPDATED THE FORECAST ACCORDINGLY. OTHERWISE FORECAST
REMAINS IN GOOD SHAPE WITH JUST A FEW CHANGES TO INHERITED POPS TO
REFLECT LATEST RADAR TRENDS AND INCREASING CONFIDENCE THAT MOST
AREAS WILL SEE AT LEAST A HUNDREDTH TODAY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM EDT MON SEP 15 2014
THE NEXT UPPER LEVEL SHORT WAVE OF INTEREST IS WELL PRONOUNCED ON
WATER VAPOR IMAGERY THIS MORNING ACROSS THE DAKOTAS. ALREADY HAVE
NOTED SOME VERY WEAK ELEVATED ECHOES UPSTREAM ACROSS
CENTRAL/NORTHERN ILLINOIS WHERE BACKING OF LOW LEVEL WINDS HAS
ALLOWED FOR AN INCREASE AN ISENTROPIC LIFT. AT LEAST OVER THE NEXT
SEVERAL HOURS...SHOWER POTENTIAL SEEMS SOMEWHAT MINIMAL DUE TO
HIGHLY ELEVATED NATURE OF THIS FORCING AND INITIALLY QUITE DRY LOW
LEVELS. SOUTHWESTERLY LOW LEVEL FLOW WILL RAMP UP SOMEWHAT IN
ADVANCE OF THIS WAVE ALLOWING BROAD WEAK LOW LEVEL THETAE RIDGING
ACROSS THE MID MISSISSIPPI RIVER VALLEY TO SHIFT INTO THE OHIO
VALLEY/SOUTHERN GREAT LAKES. LOW/MID LEVEL FRONTOGENESIS WILL ALSO
BE ON THE UPSWING IN ADVANCE OF THIS WAVE...ESPECIALLY DURING THE
MID TO LATE AFTERNOON HOURS. LOCAL AREA WILL ALSO BECOME
INCREASINGLY FAVORED IN RIGHT ENTRANCE REGION OF GREAT LAKES UPPER
JET STREAK. GIVEN FAIRLY STRENGTH OF UPPER WAVE...MID/UPPER LEVEL
FRONTOGENESIS...AND STRENGTHENING ISENTROPIC UPGLIDE...HAVE STAYED
THE COURSE WITH HIGH END LIKELY POPS. MAY EVENTUALLY NEED TO
CONSIDER NUDGING INTO CATEGORICAL POP RANGE FOR PORTIONS OF THE AREA
HOWEVER AS STRONGER ISENTROPIC UPGLIDE/FRONTAL FORCING BECOME
ESTABLISHED LATER THIS AFTERNOON/EARLY EVENING. MAIN TWEAK TO
FORECAST WAS TO PUSH TIMING OF HIGHER POPS BACK JUST A FEW HOURS
INTO THE LATE AFTERNOON HOURS AS APPROACHING FRONTAL FORCING SHOULD
ALLOW PRECIP TO CONTINUE.
A FEW THUNDERSTORMS HAVE DEVELOPED ACROSS SOUTHERN IOWA THIS MORNING
IN ZONE OF STRONGER ISENTROPIC LIFT/LOW LEVEL MASS CONVERGENCE.
CURRENT FORECAST THINKING IS THAT BETTER THUNDER POTENTIAL WILL
REMAIN SOUTHWEST OF LOCAL AREA IN RICHER LOW LEVEL THETAE AIRMASS.
WHILE CANNOT COMPLETELY RULE OUT AN ISOLATED THUNDERSTORM
PARTICULARLY ACROSS THE SOUTHWEST...FEEL PROSPECTS ARE BELOW
MENTIONABLE LEVELS AT THIS TIME.
AXIS OF MORE PRONOUNCED MID LEVEL FRONTO FORCING TO LINGER ACROSS
THE CENTRAL/EASTERN AREAS EARLY THIS EVENING WHERE HAVE CARRIED
LIKELY POPS...WITH CONDITIONS DRYING OUT FROM WEST TO EAST. SKIES
SHOULD CLEAR OR PARTIALLY CLEAR TONIGHT AS LOW LEVEL TROUGH AXIS
CLEARS AREA...ALTHOUGH AS HAS BEEN THE CASE OVER THE PAST SEVERAL
DAYS...PERSISTENT LOW LEVEL INVERSION GIVES SOME HESITATION FOR MORE
LONGEVITY OF STRATOCU THAN CURRENTLY FORECASTED. LOWS SHOULD DROP
INTO THE MID 40S TONIGHT...BUT PROBABLY MORE INTO THE UPPER 40S TO
AROUND 50 RANGE WHERE STRATUS PERSISTS LONGER. SOME LAKE EFFECT LOW
CLOUDINESS MAY ALSO PROVIDE WARMER CONDITIONS NEAR THE NW INDIANA
LAKESHORE AREAS...BUT LAKE INDUCED INSTABILITY DEPTHS APPEAR TO BE
TOO SHALLOW FOR ANY PRECIP INCLUSION AT THIS TIME.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 445 AM EDT MON SEP 15 2014
TRANQUIL WEATHER IS EXPECTED FOR TUESDAY INTO SATURDAY WITH
GRADUALLY MODERATING TEMPERATURES AS THE FLOW BECOMES MORE HIGH
ZONAL AND AS THE AIRMASS OVER THE AREA MODIFIES. AT THE START OF THE
PERIOD...THE SHORT WAVE WILL HAVE MOVED EAST OF THE AREA BY TUESDAY
MORNING...WITH DECREASING CLOUDS EXPECTED DURING THE DAY AS
SUBSIDENCE BEHIND THE TROF INCREASES. FAVORABLE NOCTURNAL
RADIATIONAL COOLING CONDITIONS ARE EXPECTED TUESDAY NIGHT WITH LOWS
DROPPING WELL BELOW 50 DEGREES. COULD BE SOME PATCHY FROST IN
LOCALLY COLD SPOTS...BUT OTHERWISE...FROST IS NOT EXPECTED AND HAVE
NOT MENTIONED ANY FROST IN THE GRIDS/FORECAST. THE GFS HAS BEEN
REASONABLY CONSISTENT WITH THE WARM UP THIS WEEK...AND THE GFS/MEX
MEAN ENSEMBLE MOS TEMPERATURES APPEAR ON TRACK. FOR THIS COMING
WEEKEND...THE GFS AND ECMWF HAVE COME INTO A LITTLE BETTER AGREEMENT
ON TIMING OF THE NEXT SYSTEM...WITH AN UPPER LEVEL SYSTEM AND
ASSOCIATED COLD FRONT MOVING ACROSS THE AREA BY LATE IN THE WEEKEND.
FOR NOW...KEPT A CHANCE FOR SHOWERS SATURDAY THROUGH SUNDAY. THUNDER
MAY NEED TO BE ADDED AT SOME POINT...BUT FOR NOW KEPT THUNDER OUT
GIVEN CAPE VALUES VERY SMALL PER GFS/BUFKIT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 145 PM EDT MON SEP 15 2014
SHORTWAVE TROUGH IS CURRENTLY APPROACHING THE AREA AND EXPECT
SHOWERS TO GRADUALLY EXPAND ACROSS NORTHERN INDIANA BY LATE THIS
AFTERNOON. UPSTREAM OBSERVATIONS SUGGEST IT WILL TAKE SOME TIME
FOR BETTER LOW LEVEL MOISTURE...AND MVFR CONDITIONS...TO DEVELOP.
PUSHED BACK THE TIMING A BIT BUT FORECAST SOUNDINGS STILL SUPPORT
FUEL ALTERNATE CONDITIONS AS THE RAIN MOVES THROUGH THIS EVENING.
PATCHY FOG WILL ALSO BE POSSIBLE LATE TONIGHT GIVEN RESIDUAL LOW
LEVEL MOISTURE...DEVELOPING INVERSION...AND LIGHT SURFACE WINDS.
CONFIDENCE IS STILL LOW HOWEVER AND A STRATUS DECK CANNOT BE
RULED OUT. INTRODUCED MVFR CONDITIONS FOR KFWA BASED ON MOS
GUIDANCE AND BETTER MOISTURE SEEN IN FORECAST SOUNDINGS BUT LEFT
KSBN VFR FOR NOW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...AGD
SYNOPSIS...MCD
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...AGD
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
102 PM CDT MON SEP 15 2014
.UPDATE...
ISSUED AT 1253 PM CDT MON SEP 15 2014
STRATOCU DECK FORMING IN THE CAA BEHIND THE COLD FRONT WILL HELP
KEEP TEMPS COOLER IN THE NORTH THIS AFTERNOON...SO HAVE LOWERED
HIGHS SEVERAL DEGREES. 925-850 MB FG FORCING IS QUICKLY WANING IN
CENTRAL IOWA AS THE UPPER LEVEL WAVE SHIFTS EASTWARD AND IS BEING
REFLECTED IN RECENT RADAR SIGNATURES FROM KDMX...SHOWING THE BAND
OF PRECIP WEAKENING AND SHRINKING IN COVERAGE. HAVE LOWERED POPS
AHEAD OF THE LINE AND CONTINUED TRENDS TO EXIT THE PRECIP FROM
THE CWA BY 20Z.
&&
.SHORT TERM /TODAY/...
ISSUED AT 323 AM CDT MON SEP 15 2014
PRECIP AND TEMP TRENDS WILL BE THE PRIMARY CONCERNS TODAY. MEAN
TROUGH CONTINUES TO ADVANCE THROUGH THE NRN CONUS THIS MORNING.
WEAK KINEMATICALLY FORCED PRECIP CONTINUES OVER SD/MN/WI JUST
BRUSHING NRN IA. THIS IS DRIVEN BY DPVA AHEAD OF POTENT DAKOTAS
SHORT WAVE/PV ANOMALY AND RIGHT ENTRANCE REGION OF GREAT LAKES JET
SEGMENT. FARTHER SOUTH WARM/THETA-E ADVECTION HAS STRENGTHENED IN
RESPONSE ALONG MO VALLEY BAROCLINIC AND FRONTOGENESIS ZONE.
INSTABILITY HAS INCREASED IN THIS RETURN FLOW WITH UNCAPPED 500
J/KG MUCAPES ENTERING SWRN IA...ROOTED 1-1.5KM. EFFECTIVE SHEAR IS
PUSHING 50KTS IN THIS AREA AND RESULTED IN A FEW SUB SEVERE HAIL
REPORTS OVER FAR ERN NE.
THIS THERMODYNAMIC FORCING AND INSTABILITY WILL BE LIMITED IN
TIME HOWEVER. RAP 305K ISENT SURFACE SHOWS THIS LIFT PUSHING
SOUTHWARD OUT OF THE STATE WITH TIME AS LONG WAVE TROUGH
APPROACHES. THIS WILL BRING MUCH OF THE STATE UNDER THE INFLUENCE
OF KINEMATIC RATHER THAN THERMODYNAMIC FORCING WHICH SHOULD SPREAD
INTO IA WITH TIME. MOISTURE WAS LIMITED INITIALLY BUT EXPECT
FORCING TO SOON INDUCE SATURATION AND MORE WIDESPREAD PRECIP. THE
PRONOUNCED SUBSIDENCE/LIFT COUPLET WILL BE EXITING ERN SECTIONS BY
18Z HOWEVER SO MUCH OF THE FORECAST AREA SHOULD BE DRY BY EARLY
AFTERNOON.
08Z SURFACE ANALYSIS APPEARS TO SHOW TWO FRONTS...ONE FROM KS/MO
TO BETWEEN CRESTON AND DES MOINES...WITH ANOTHER FROM THE AMES
AREA TO JUST SOUTH OF WATERLOO. THESE SHOULD QUICKLY PHASE AND
EXIT THE AREA BY 18Z PRODUCING PROBLEMATIC AND IN PLACES NON-
DIURNAL TEMP TRENDS. READINGS SHOULD REBOUND LITTLE SE WITH SYSTEM
EFFECTS LINGERING LONGER. HOWEVER FAR NW SHOULD SEE THE PRECIP END
EARLIER WITH CLEARING AND MORE POTENTIAL FOR MIXING AND REBOUND.
THIS RESULTS IN FAIRLY HOMOGENEOUS AND LOW CONFIDENCE TEMP
FORECAST IN THE LOWER 60S NEAR MOS GUIDANCE BLEND.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 323 AM CDT MON SEP 15 2014
FROM TONIGHT THROUGH THURSDAY THE WEATHER WILL BE DRY AND QUIET
WITH A SLOW WARMING TREND. A SURFACE HIGH PRESSURE AREA WILL BE
DRAPED ACROSS IOWA OVERNIGHT ALLOWING TEMPERATURES TO FALL INTO
THE UPPER 30S IN SOME AREAS...HOWEVER NO SIGNIFICANT FROST EFFECTS
ARE ANTICIPATED AS TEMPERATURES SHOULD NOT DROP TO THE LEVELS SEEN
ON SATURDAY MORNING. PATCHY TO POSSIBLY WIDESPREAD FOG DEVELOPMENT
IS ANTICIPATED PARTICULARLY IN AREAS WHERE RAIN FALLS THIS
MORNING. ON TUESDAY NIGHT AND WEDNESDAY A ZONE OF WARM AIR
ADVECTION JUST TO OUR SOUTHWEST SHOULD GENERATE SOME SHOWERS AND
STORMS FROM EASTERN NEBRASKA DOWN INTO MISSOURI...BUT THIS
ACTIVITY IS EXPECTED TO MISS OUR FORECAST AREA WITH JUST SOME
SLIGHT POPS MAINTAINED IN THE SOUTHWEST CORNER AND NO IMPACTS
EXPECTED.
BY THURSDAY LOW LEVEL WINDS WILL HAVE TURNED AROUND TO SOUTH
SOUTHEAST ALLOWING THE AFOREMENTIONED SLOW WARMING
TREND...MEANWHILE A DEEP LAYER THERMAL RIDGE WILL HAVE BUILT
DOWN THE HIGH PLAINS FROM THE DAKOTAS TO THE TEXAS PANHANDLE. THIS
RIDGE WILL SUBSEQUENTLY SHIFT EASTWARD...HOWEVER A 500 MB
SHORTWAVE MOVING AROUND ITS PERIPHERY WILL ALSO DIG DOWN ACROSS
MINNESOTA AND WISCONSIN AND FLATTEN THE RIDGE DOWN TOWARD THE
SOUTH. THIS SHORTWAVE WILL LIKELY GENERATE SOME THUNDERSTORMS FROM
THURSDAY NIGHT INTO FRIDAY...THE MAJORITY OF WHICH WILL REMAIN TO
OUR NORTHEAST BUT SOME MAY CLIP AREAS AROUND MASON CITY AND
WATERLOO AROUND FRIDAY MORNING. HAVE MAINTAINED CHANCE POPS TO
ACCOUNT FOR THIS. BY LATE IN THE DAY FRIDAY...IN WAKE OF THESE
STORMS...A WEAKLY DEFINED SURFACE TROUGH WILL BE DRAPED FROM
CENTRAL MINNESOTA DOWN TO WESTERN NEBRASKA. SOUTH OF THIS BOUNDARY
MOST OF OUR FORECAST AREA...ESPECIALLY THE SOUTHERN HALF...SHOULD
SEE MORE ROBUST WARMING WITH TEMPERATURES IN THE LOWER 80S
POSSIBLE. HOWEVER...THIS WILL BE BROUGHT TO A QUICK END AS ANOTHER
500 MB WAVE COMING OVER THE NORTHERN ROCKIES OF MONTANA WILL
RAPIDLY DEEPEN AS IT MOVES SOUTHEAST OVER THE MIDWEST ON FRIDAY
NIGHT AND SATURDAY. THIS WILL SHARPEN THE SURFACE TROUGH AND PUSH
IT ACROSS IOWA ON SATURDAY.
THE PASSAGE OF THE SURFACE FRONT AND MID LEVEL WAVE ON FRIDAY
NIGHT/SATURDAY WILL UNDOUBTEDLY TRIGGER SOME SHOWERS AND
THUNDERSTORMS ACROSS THE AREA. HOWEVER...COVERAGE AND TIMING
REMAIN SOMEWHAT UNCERTAIN AND HAVE KEPT ONLY 40 TO 60 POPS IN EACH
PERIOD FOR NOW UNTIL SOLUTIONS CONVERGE. OF POTENTIALLY GREATER
CONSEQUENCE IS HURRICANE ODILE...WHICH IS CURRENTLY MAKING
LANDFALL OVER THE BAJA CALIFORNIA AND WILL DRIFT SLOWLY
NORTHEASTWARD OVER THE DESERT SOUTHWEST...REFLECTED BY A LARGE
SLUG OF DEEP MOISTURE AND A WEAKENING LOW PRESSURE CENTER. SOME
GFS SOLUTIONS HAVE BEEN ADVECTING THE MOISTURE FAR ENOUGH
NORTHEAST BY THE END OF THE WEEK THAT IT IS DRAWN UP ALONG THE
SURFACE FRONT...BRINGING A SIGNIFICANT HEAVY RAIN THREAT TO PARTS
OF THE REGION AND POTENTIALLY IOWA. HOWEVER...THESE SOLUTIONS HAVE
BEEN INCONSISTENT AND THE ECMWF HAS BEEN KEEPING THE ODILE
MOISTURE FAR ENOUGH TO THE SOUTHWEST THAT IT IS NOT DRAWN EASTWARD
UNTIL THE FRONT HAS ALREADY PASSED THROUGH IOWA. THIS PARTICULAR
SCENARIO IS UNSTABLE IN THE SENSE THAT IT RELIES ON THE SLOW DRIFT
OF A CYCLONE JUST MAKING LANDFALL...AS WELL AS THE TIMING AND
MOTION OF OTHER ATMOSPHERIC FEATURES THAT DO NOT EVEN EXIST YET.
WE WILL CONTINUE TO MONITOR THIS POTENTIAL THROUGHOUT THE WEEK.
&&
.AVIATION...15/18Z
ISSUED AT 1253 PM CDT MON SEP 15 2014
IFR TO MVFR CEILINGS TIED IN WITH THE FRONTAL BOUNDARY PASSING
THROUGH CENTRAL IOWA SHOULD GRADUALLY LIFT AND SHIFT SOUTHEASTWARD
THIS AFTERNOON AS A HIGH BUILDS INTO THE REGION. WINDS WILL ALSO
LESSEN AS THE PRESSURE GRADIENT RELAXES CLOSER TO THE HIGH.
INTRODUCED MVFR TO IFR FOG INTO MOST TAF SITES FROM 09-14Z...WITH
THE LOWEST RESTRICTIONS IN THE SOUTH WHERE THE HEAVIEST RAIN FELL
TODAY AND THE CENTER OF THE HIGH WILL PASS OVERHEAD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SKOW
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...SKOW
AREA FORECAST DISCUSSION
NWS JACKSON KY
600 PM EDT MON SEP 15 2014
.UPDATE...
ISSUED AT 600 PM EDT MON SEP 15 2014
UPDATED THE FORECAST TO REFLECT HIGHER POPS ACROSS THE FAR SOUTH WITH
THE DISTURBANCE PUSHING ACROSS THE AREA..AND NOW HAVE INCREASED POPS
NORTH OF THE MOUNTAIN PARKWAY THIS EVENING AS A COMPLEX OF WEAKENING
SHOWERS WILL BE ARRIVING BETWEEN 6 AND 8 PM. IN BETWEEN THESE TWO
AREAS...NOT MUCH EXPECTED THROUGH 10 PM AS THE COLD FRONT REMAINS
WELL TO OUR NORTHWEST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON SEP 15 2014
19Z SFC ANALYSIS SHOWS EAST KENTUCKY BETWEEN TWO AREAS OF LOW
PRESSURE AND THEIR FRONTAL BOUNDARIES. THERE IS A DEVELOPING SYSTEM
TO THE NORTHWEST WHILE AN OLD FRONT IS FOUND JUST SOUTH OF THE
BORDER. TO THE EAST OF THE AREA...WEAK HIGH PRESSURE IS GIVING WAY
TO THE ADVANCE OF THE LOW AND ITS FRONT TO THE NORTHWEST. A BAND OF
SHOWERS AND THUNDERSTORMS ARE FOUND ALONG THIS BOUNDARY SLOWLY
HEADING THIS WAY...HOWEVER IT IS THE FRONT TO THE SOUTH THAT IS
KICKING UP ENOUGH IN THE WAY OF SHOWERS THAT MANY PLACES SOUTH OF THE
HAL ROGERS PARKWAY MAY SEE ENOUGH ACTIVITY AMONG THE SPRINKLES TO
ACTUALLY MEASURE. OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ARE FOUND
THROUGH THE AREA WITH TEMPERATURES GENERALLY BETWEEN 70 AND 75
DEGREES WHILE DEWPOINTS VARY FROM THE MIDDLE 50S NORTH TO THE LOW
AND MIDDLE 60S IN THE FAR SOUTH. WINDS ARE GENERALLY LIGHT FROM THE
SOUTH TO SOUTHWEST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT AS THEY ALL REINFORCE THE
EXISTING LONGWAVE TROUGH OVER THE EASTERN HALF OF THE NATION WITH A
SIGNIFICANT WAVE CROSSING THROUGH THE NORTHERN OHIO VALLEY TONIGHT.
SOME ENERGY ALSO MOVES THROUGH TO THE SOUTH OF THIS...SQUEEZING BY
JUST NORTH OF A FLAT RIDGE ALONG THE GULF COAST. THE TROUGH HOLDS
FAST THROUGH THE AREA INTO WEDNESDAY MORNING WITH WEAK WAVES PASSING
THROUGH KENTUCKY DURING THE DAY TUESDAY AND SOUTH OF THE STATE THAT
NIGHT. GIVEN THE MODEL SIMILARITIES...HAVE FAVORED THE HIGHER
RESOLUTION HRRR AND NAM12 FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE NORTHWEST FRONT DROPPING THROUGH
EAST KENTUCKY TONIGHT WITH A BAND OR TWO OF SHOWERS EXPECTED...AS THE
THUNDER FADES TOWARD SUNSET. THE SOUTHERN PARTS OF THE AREA WILL SEE
THE SPRINKLES AND LIGHT SHOWERS PRESS OFF TO THE SOUTHEAST WITH TIME
INTO THIS EVENING. AREAS OF FOG WILL BE POSSIBLE LATE TONIGHT...BUT
SHOULD BE LESS THAN THE PAST FEW DAYS DUE TO THE CLOUDS AND PCPN
AROUND. FOR TUESDAY...A COUPLE OF SHOWERS MAY LINGER THROUGH THE AREA
BEFORE DRIER AIR AND A NEW COOL SHOT MOVES INTO THE AREA. THIS
RENEWED HIGH PRESSURE WILL BRING ANOTHER UNSEASONABLY CHILLY NIGHT
TO MUCH OF EAST KENTUCKY WITH VALLEY FOG AGAIN A CONCERN.
USED THE CONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE FIRST 24 HOURS BEFORE LOADING THE SUPER BLEND THEREAFTER.
DID TWEAK THE LOWS TONIGHT AND TUESDAY FOR RIDGE AND VALLEY
DIFFERENCES. AS FOR POPS...ENDED UP CLOSE TO A BLEND OF THE MOS
GUIDANCE TONIGHT AND TUESDAY...THEN IN-LINE AND DRY ON TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 304 PM EDT MON SEP 15 2014
HIGH PRESSURE OVER THE OHIO VALLEY/GREAT LAKES REGION...UNDER NW FLOW
ALOFT...WILL BE OUR PRIMARY INFLUENCE FOR THE FIRST PART OF THE
PERIOD. THIS WILL RESULT IN MOSTLY DRY WEATHER WITH TEMPERATURES NEAR
OR BELOW SEASONAL NORMALS. AS THE HIGH DRIFTS EAST AND OUR LOW LEVEL
FLOW SHIFTS TOWARD THE SOUTH...MODELS HINT AT ENOUGH MOISTURE RETURN
FOR A SLIGHT CHANCE OF CONVECTIVE PRECIP OVER THE HIGH TERRAIN OF THE
APPALACHIANS ON FRIDAY...INCLUDING FAR SE KY. THIS HAS HELD TRUE
OVER THE LAST FEW MODEL RUNS...SO WILL CONTINUE TO INCLUDE SLIGHT
CHANCES IN THE FORECAST PACKAGE.
A LITTLE BIT BETTER CHANCE OF RAIN WILL HOLD OFF UNTIL SUNDAY. THIS
WILL OCCUR AS A STORM SYSTEM DEEPENS AND HEADS EAST OVER ONTARIO AND
QUEBEC...AND ITS TRAILING COLD FRONT ENTERS KY FROM THE NW WITH AN
INCREASE IN MOISTURE FROM THE GULF OF MEXICO AHEAD OF IT. THIS FAR
OUT IN THE FORECAST PERIOD...TO PUT FAITH IN ANY ONE MODEL FOR
TIMING OF PRECIP WILL PROVE UNWISE. WILL CONTINUE WITH MODEL
CONSENSUS AT THIS TIME. THOUGH DO HAVE TO SAY...ALL MODELS ARE IN
FAIRLY GOOD AGREEMENT FOR THIS FRONT AND A LINE OF ASSOCIATED PRECIP
TO MOVE THROUGH KY SUNDAY AFTERNOON AND AND OVERNIGHT SUNDAY NIGHT.
LEADING UP TO THIS FRONTAL PASSAGE...LOW AND MID LEVEL WINDS WILL
BECOME MORE SOUTHERLY. WITH HIGH PRESSURE AND ABUNDANT SUNSHINE
STILL IN PLACE...TEMPS WILL RISE TO CLOSER TO NORMAL FOR THIS TIME
OF YEAR BY FRIDAY...IN THE UPPER 70S TO AROUND 80. THESE WARMER
TEMPS WILL REMAIN IN PLACE UNTIL THE FRONTAL PASSAGE SUNDAY/SUNDAY
NIGHT. MOST OF THE INSTABILITY WILL BE CENTERED TO OUR NORTH IN
ASSOCIATION WITH THIS FRONTAL ZONE. THERE IS ONLY A VERY SMALL
AMOUNT OF CAPE...AND LAPSE RATES ARE QUITE UNIMPRESSIVE. AS
SO...WILL KEEP MENTION OF THUNDER OUT OF FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 220 PM EDT MON SEP 15 2014
A COLD FRONT WILL MOVE THROUGH EAST KENTUCKY DURING THE AVIATION
PERIOD. THIS WILL BRING A PERIOD OF LOWER CIGS...DOWN INTO MVFR...
AND THE POTENTIAL FOR SCATTERED SHOWERS LATER TONIGHT. ADDED A VCSH
FOR THE SHOWERS TO ALL THE TAFS. THE EXTRA CLOUDS AND PCPN AROUND
SHOULD BE ENOUGH TO KEEP THE FOG AND STRATUS AT BAY TONIGHT INTO
TUESDAY MORNING. WINDS THROUGH THE PERIOD WILL BE GENERALLY LIGHT
SWITCHING FROM SOUTHWEST TO NORTHWEST WITH TIME.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
519 PM EDT Mon Sep 15 2014
...Forecast Update...
Issued at 518 PM EDT Mon Sep 15 2014
Most of the models have done a pretty terrible job forecasting the
rain crossing southern Indiana at this hour. The HRRR and RR seem
to have a handle on it now, and they move it largely intact from
southeastern Indiana into the northern Blue Grass. This fits with
current mesoanalysis showing increased deep moisture convergence in
that region. The convection has been weakening as it approaches,
but PoPs still need to be increased dramatically north through east
of Louisville for at least some light rain with embedded moderate
rain and even a rumble or two of thunder over the next few hours.
.SHORT TERM (Now through Tuesday Night)...
Issued at 255 PM EDT Mon Sep 15 2014
The synoptic pattern this afternoon features a broad trough across
the eastern 2/3rds of the CONUS. This trough will amplify slightly
through the short term period as a strong shortwave slides through
the southern Great Lakes region tonight.
Latest water vapor imagery depicts the aforementioned shortwave
sliding through western IL as of this writing. In response, a
low-level jet of around 30 knots has helped to maintain elevated
convection across portions of IL and IN early this afternoon. The
near-term forecast challenge will be whether or not this activity
makes it into our Indiana counties. Given its current orientation,
the WSW LLJ should continue to foster development on it`s southwest
flank which should keep it going over the next couple of hours.
However, as we get towards 21Z and after, the 850mb flow will veer
enough that favorable inflow into this activity will be lost, thus
likely causing it to weaken. Have introduced thunder wording into
southern IN counties for a bit early this evening, but think this
convection will likely be in a weakening state as it approaches the
region given the loss of favorable elevated inflow.
The cold front associated with this system remains well back across
portions of MO and NW IL. It will push through the region Tuesday
morning. Out ahead of it, guidance continues to suggest some light
showers will be possible tonight. Given the main upper-level
forcing is passing well north of the region, this front will only
have low-level ascent to produce any QPF. In addition, moisture
within this region of ascent is very shallow (around 200mb deep).
Therefore, really don`t think many will see measurable precip. The
most likely scenario will be some patchy drizzle, with perhaps a few
locations reporting a hundredth or two in some light shower
activity.
Any precip will come to an end by mid-morning Tuesday, but cloud
cover will likely linger into the late morning north and afternoon
across the south. Have trended temps down a bit for Tuesday to
account for this expected cloud cover through at least the first
part of the day, which puts highs in the upper 60s and lower 70s.
A surface ridge will build into the region Tuesday night as skies go
mainly clear. This will make for good radiational cooling
conditions, which will allow temps to dip into the mid 40s across
southern IN, and upper 40s/lower 50s across KY.
.LONG TERM (Wednesday through Monday)...
Issued at 300 PM EDT Mon Sep 15 2014
High pressure will be centered over northern IN/OH Wednesday
morning. An upper disturbance will cross within the northwest flow
aloft during the day, but with no surface reflection. Thus just
expect some mid/high clouds to keep afternoon highs below normal.
Another disturbance passing by to our north Thursday will allow a
reinforcing high pressure centered over SE Canada to ridge over the
east central U.S., keeping our temperatures below normal and weather
dry to Friday.
The next shot for rain looks to come as a more organized surface low
crosses the northern Great Lakes Sunday and drags a cold front
through here. Timing of this system is fairly uniform among the
GFS/00Z Euro/Navy NOGAPS ensemble. Also looks like we may get an
influx of tropical moisture ahead of the front, so will keep
highlighting the best chance for rain on Sunday/Sunday night. Then
will go dry for Monday for all but our southeast forecast area, as
another cool shot of air builds in from Canada.
Temperatures will warm up ahead of this front, likely into at least
the low 80s Saturday and perhaps even around 80 over southern KY
Sunday.
&&
.AVIATION (18Z TAF Update)...
Issued at 110 PM EDT Mon Sep 15 2014
The main focus of the TAF period will be a cold frontal passage
tonight, which may bring a period of MVFR cigs to all sites along
with some light showers. For the remainder of the afternoon hours
today, expect VFR conditions with increasing mid/high cloud cover.
Winds will be out of the WSW at 4-7 knots.
Later this evening into tonight, a cold front will approach the
region. There will be a few showers along this front that may drop
some light amounts here and there, but coverage and associated
aviation impacts will remain limited. The more impactful aspect of
this system will come after the fropa, as it looks like a period of
at least MVFR stratus will affect all sites Tuesday morning.
Guidance suggests even IFR cigs will be possible, but given the
limited moisture this system has to work with, will go more
optimistic and advertise fuel-alternate MVFR cigs for now.
Ceilings will slowly rise Tuesday morning, but likely won`t go VFR
until the late morning or early afternoon. Winds will be out of the
north at 5-10 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........13
Short Term.....KJD
Long Term......RJS
Aviation.......KJD
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
350 PM EDT MON SEP 15 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON SEP 15 2014
19Z SFC ANALYSIS SHOWS EAST KENTUCKY BETWEEN TWO AREAS OF LOW
PRESSURE AND THEIR FRONTAL BOUNDARIES. THERE IS A DEVELOPING SYSTEM
TO THE NORTHWEST WHILE AN OLD FRONT IS FOUND JUST SOUTH OF THE
BORDER. TO THE EAST OF THE AREA...WEAK HIGH PRESSURE IS GIVING WAY
TO THE ADVANCE OF THE LOW AND ITS FRONT TO THE NORTHWEST. A BAND OF
SHOWERS AND THUNDERSTORMS ARE FOUND ALONG THIS BOUNDARY SLOWLY
HEADING THIS WAY...HOWEVER IT IS THE FRONT TO THE SOUTH THAT IS
KICKING UP ENOUGH IN THE WAY OF SHOWERS THAT MANY PLACES SOUTH OF THE
HAL ROGERS PARKWAY MAY SEE ENOUGH ACTIVITY AMONG THE SPRINKLES TO
ACTUALLY MEASURE. OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES ARE FOUND
THROUGH THE AREA WITH TEMPERATURES GENERALLY BETWEEN 70 AND 75
DEGREES WHILE DEWPOINTS VARY FROM THE MIDDLE 50S NORTH TO THE LOW
AND MIDDLE 60S IN THE FAR SOUTH. WINDS ARE GENERALLY LIGHT FROM THE
SOUTH TO SOUTHWEST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT AS THEY ALL REINFORCE THE
EXISTING LONGWAVE TROUGH OVER THE EASTERN HALF OF THE NATION WITH A
SIGNIFICANT WAVE CROSSING THROUGH THE NORTHERN OHIO VALLEY TONIGHT.
SOME ENERGY ALSO MOVES THROUGH TO THE SOUTH OF THIS...SQUEEZING BY
JUST NORTH OF A FLAT RIDGE ALONG THE GULF COAST. THE TROUGH HOLDS
FAST THROUGH THE AREA INTO WEDNESDAY MORNING WITH WEAK WAVES PASSING
THROUGH KENTUCKY DURING THE DAY TUESDAY AND SOUTH OF THE STATE THAT
NIGHT. GIVEN THE MODEL SIMILARITIES...HAVE FAVORED THE HIGHER
RESOLUTION HRRR AND NAM12 FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE THE NORTHWEST FRONT DROPPING THROUGH
EAST KENTUCKY TONIGHT WITH A BAND OR TWO OF SHOWERS EXPECTED...AS THE
THUNDER FADES TOWARD SUNSET. THE SOUTHERN PARTS OF THE AREA WILL SEE
THE SPRINKLES AND LIGHT SHOWERS PRESS OFF TO THE SOUTHEAST WITH TIME
INTO THIS EVENING. AREAS OF FOG WILL BE POSSIBLE LATE TONIGHT...BUT
SHOULD BE LESS THAN THE PAST FEW DAYS DUE TO THE CLOUDS AND PCPN
AROUND. FOR TUESDAY...A COUPLE OF SHOWERS MAY LINGER THROUGH THE AREA
BEFORE DRIER AIR AND A NEW COOL SHOT MOVES INTO THE AREA. THIS
RENEWED HIGH PRESSURE WILL BRING ANOTHER UNSEASONABLY CHILLY NIGHT
TO MUCH OF EAST KENTUCKY WITH VALLEY FOG AGAIN A CONCERN.
USED THE CONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE FIRST 24 HOURS BEFORE LOADING THE SUPERBLEND THEREAFTER.
DID TWEAK THE LOWS TONIGHT AND TUESDAY FOR RIDGE AND VALLEY
DIFFERENCES. AS FOR POPS...ENDED UP CLOSE TO A BLEND OF THE MOS
GUIDANCE TONIGHT AND TUESDAY...THEN IN-LINE AND DRY ON TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 304 PM EDT MON SEP 15 2014
HIGH PRESSURE OVER THE OHIO VALLEY/GREAT LAKES REGION...UNDER NW FLOW
ALOFT...WILL BE OUR PRIMARY INFLUENCE FOR THE FIRST PART OF THE
PERIOD. THIS WILL RESULT IN MOSTLY DRY WEATHER WITH TEMPERATURES NEAR
OR BELOW SEASONAL NORMALS. AS THE HIGH DRIFTS EAST AND OUR LOW LEVEL
FLOW SHIFTS TOWARD THE SOUTH...MODELS HINT AT ENOUGH MOISTURE RETURN
FOR A SLIGHT CHANCE OF CONVECTIVE PRECIP OVER THE HIGH TERRAIN OF THE
APPALACHIANS ON FRIDAY...INCLUDING FAR SE KY. THIS HAS HELD TRUE
OVER THE LAST FEW MODEL RUNS...SO WILL CONTINUE TO INCLUDE SLIGHT
CHANCES IN THE FORECAST PACKAGE.
A LITTLE BIT BETTER CHANCE OF RAIN WILL HOLD OFF UNTIL SUNDAY. THIS
WILL OCCUR AS A STORM SYSTEM DEEPENS AND HEADS EAST OVER ONTARIO AND
QUEBEC...AND ITS TRAILING COLD FRONT ENTERS KY FROM THE NW WITH AN
INCREASE IN MOISTURE FROM THE GULF OF MEXICO AHEAD OF IT. THIS FAR
OUT IN THE FORECAST PERIOD...TO PUT FAITH IN ANY ONE MODEL FOR
TIMING OF PRECIP WILL PROVE UNWISE. WILL CONTINUE WITH MODEL
CONSENSUS AT THIS TIME. THOUGH DO HAVE TO SAY...ALL MODELS ARE IN
FAIRLY GOOD AGREEMENT FOR THIS FRONT AND A LINE OF ASSOCIATED PRECIP
TO MOVE THROUGH KY SUNDAY AFTERNOON AND AND OVERNIGHT SUNDAY NIGHT.
LEADING UP TO THIS FRONTAL PASSAGE...LOW AND MID LEVEL WINDS WILL
BECOME MORE SOUTHERLY. WITH HIGH PRESSURE AND ABUNDANT SUNSHINE
STILL IN PLACE...TEMPS WILL RISE TO CLOSER TO NORMAL FOR THIS TIME
OF YEAR BY FRIDAY...IN THE UPPER 70S TO AROUND 80. THESE WARMER
TEMPS WILL REMAIN IN PLACE UNTIL THE FRONTAL PASSAGE SUNDAY/SUNDAY
NIGHT. MOST OF THE INSTABILITY WILL BE CENTERED TO OUR NORTH IN
ASSOCIATION WITH THIS FRONTAL ZONE. THERE IS ONLY A VERY SMALL
AMOUNT OF CAPE...AND LAPSE RATES ARE QUITE UNIMPRESSIVE. AS
SO...WILL KEEP MENTION OF THUNDER OUT OF FORECAST AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 220 PM EDT MON SEP 15 2014
A COLD FRONT WILL MOVE THROUGH EAST KENTUCKY DURING THE AVIATION
PERIOD. THIS WILL BRING A PERIOD OF LOWER CIGS...DOWN INTO MVFR...
AND THE POTENTIAL FOR SCATTERED SHOWERS LATER TONIGHT. ADDED A VCSH
FOR THE SHOWERS TO ALL THE TAFS. THE EXTRA CLOUDS AND PCPN AROUND
SHOULD BE ENOUGH TO KEEP THE FOG AND STRATUS AT BAY TONIGHT INTO
TUESDAY MORNING. WINDS THROUGH THE PERIOD WILL BE GENERALLY LIGHT
SWITCHING FROM SOUTHWEST TO NORTHWEST WITH TIME.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
656 PM EDT MON SEP 15 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EDT MON SEP 15 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM HUDSON BAY TO THE GREAT LAKES. A SHORTWAVE TROUGH FROM CNTRL WI
INTO NE IA SUPPORTED AN AREA OF RAIN FROM SE WI INTO CNTRL LOWER MI.
THE COMINATION OF DAYTIME HEATING AND 700 MB TEMPS NEAR -8C
RESULTING IN STEEP SFC-700 MB LAPSE RATES TO 8C/KM ALONG WITH WEAK
FORCING ON THE NRN END OF THE SHRTWV AND LAKE BREEZE BOUNDARIES
HAVE SUPPORTED ISOLD/SCT LIGHT SHOWERS THAT HAVE SPREAD THROUGH
CNTRL UPPER MI THIS AFTERNOON.
TONIGHT...AS THE SHRTWV DEPARTS TO THE EAST...DAYTIME HEATING
SUBSIDES AND HIGH PRES BUILDS TOWARD THE WRN GREAT LAKES...THE PCPN
WILL END AND CLOUDS WILL THIN OUT. THE CLEARING SKIES AND LIGHT
WINDS OVER THE WESTERN INTERIOR ALONG WITH PWAT VALUES AT OR BELOW
0.5 INCH...OR 50 PCT OF NORMAL...WILL SUPPORT AREAS OF FROST INLAND
AS MIN TEMPS DIP NEAR THE FREEZING MARK ESPECIALLY IN THE WI BORDER
COUNTIES AND OTHER FAVORED COLD SPOTS INTO SW MARQUETTE COUNTY.
TUESDAY...SUNSHINE IN THE MORNING IS EXPECTED TO GIVE WAY TO
INCREASING CLOUDS IN THE AFTERNOON AS A COLD FRONT DAGS SOUTHWARD
THROUGH LAKE SUPERIOR. ANY LIGHT PCPN ASSOCIATED WITH THE FRONT AND
900-800 MB FGEN SHOULD STAY NORTH OF THE KEWEENAW UNTIL EVENING.
OTHERWISE...TEMPERATURES WILL REBOUND CLOSER TO SEASONAL AVERAGES
WITH HIGHS IN THE MID 60S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 304 PM EDT MON SEP 15 2014
NORTHWEST FLOW ALOFT WILL BE IN PLACE FOR MUCH OF THE LONG TERM
FORECAST PERIOD...KEEPING BELOW NORMAL TEMPERATURES IN PLACE
EXCEPT FOR SATURDAY.
AT THE START OF THE PERIOD (TUESDAY NIGHT)...THE HIGH PRESSURE
RIDGE MOVING OVER THE AREA TONIGHT WILL BE SHIFTING TO THE SOUTHEAST
WHILE A COLD FRONT DROPS SOUTHEAST ACROSS LAKE SUPERIOR DURING THE
LATE AFTERNOON AND EVENING HOURS. PRECIPITATION LOOKS TO BE RIGHT
ALONG OR BEHIND THE FRONT ON TUESDAY NIGHT AND THAT CONTINUES INTO
WEDNESDAY AS THE FRONT SLOWLY DROPS ACROSS UPPER MICHIGAN (DUE TO
THE MAIN SHORTWAVE AND LOW QUICKLY PEELING EAST-NORTHEAST). WITH THE
BEST DEEP MOISTURE AND Q-VECTOR CONVERGENCE REMAINING OVER THE
NORTH HALF OF THE CWA (MAINLY OVER LAKE SUPERIOR)...WILL FOCUS THE
HIGHEST POPS IN THAT AREA AND SHOW DECREASING POPS TO THE SOUTH.
THAT SIMILAR IDEA IS EXPECTED FOR QPF...WITH 0.1-0.2 INCH OVER
NORTHERN LAKE SUPERIOR TAPERING TO A TRACE-0.1 INCH OVER THE U.P.
A SECOND UPPER TROUGH (WITH THE MAIN ENERGY IN ONTARIO) WILL SLIDE
SOUTHEAST ACROSS THE U.P. WEDNESDAY AFTERNOON AND USHER IN STRONGER
NORTHWEST FLOW ALOFT AND A HIGH PRESSURE RIDGE INTO THE AREA. THIS
WILL BRING AN END TO ANY PRECIPITATION FROM NORTHWEST TO SOUTHEAST
AS THE DRIER AIR MOVES IN. THE CENTER OF THE HIGH WILL SLIDE
SOUTHEAST ACROSS NORTHERN ONTARIO AND FAR NORTHEAST LAKE SUPERIOR
ON WEDNESDAY NIGHT. THIS WILL LEAD TO THE SKY BECOMING MOSTLY
CLEAR OVER AT LEAST THE NORTHEAST HALF OF UPPER MICHIGAN AND ANOTHER
POTENTIAL FOR FROST ACROSS THE AREA. CLOSER TO THE WISCONSIN
BORDER...MODELS ARE INDICATING SOME CLOUDS LINGERING AS A WEAK
WARM AIR ADVECTION REGIME SETS UP UNDER LIGHT SOUTH-SOUTHWEST FLOW
BETWEEN 925-850MB. THUS...THINK THE BEST OPPORTUNITY FOR FROST WILL
BE OVER THE NORTH CENTRAL AND EAST...CLOSER TO THE HIGH AND
UNDERNEATH THE LOWEST PRECIPITABLE WATER VALUES (AROUND 30 PERCENT
OF NORMAL).
THE HIGH WILL SHIFT EAST ON THURSDAY AND ALLOW THAT BROAD WARM AIR
ADVECTION REGIME TO TAKE SHAPE AND CONTINUE INTO FRIDAY NIGHT.
WITH THE FLOW ALOFT BECOMING A LITTLE MORE ZONAL...THERE ARE
INDICATIONS IN THE MODELS OF WEAK SHORTWAVES SHIFTING EAST ACROSS
THE AREA THURSDAY NIGHT INTO FRIDAY AHEAD OF THE BROAD SURFACE
TROUGH STRETCHING FROM NORTHERN MANITOBA INTO THE CENTRAL PLAINS.
THEREFORE...WILL SHOW INCREASING POPS ON THURSDAY NIGHT AND
CONTINUE THEM INTO FRIDAY AND FRIDAY NIGHT. THE BROAD LOW PRESSURE
TROUGH WILL SHIFT EAST INTO THE UPPER GREAT LAKES REGION ON
SATURDAY AND BRING THE BEST PRECIPITATION CHANCES FOR THE LONG TERM
PERIOD. AT THIS TIME...DON/T EXPECT ANY WIDESPREAD MODERATE/HEAVY
RAIN BUT WILL NEED TO KEEP AN EYE ON THE EVOLUTION OF THE REMNANTS
OF HURRICANE ODILE AS IT LIFTS NORTHEAST THROUGH THE CENTRAL CONUS
AND MERGES WITH THE NORTHERN STREAM FLOW SATURDAY NIGHT. THIS COULD
LEAD TO MORE WIDESPREAD/HEAVIER PRECIPITATION THAN CURRENTLY
ANTICIPATED. UNFORTUNATELY...THE PHASING OF THOSE TWO FEATURES
LEAVES VERY LOW CONFIDENCE FOR THE SECOND HALF OF THE WEEKEND. WILL
CONTINUE THE IDEA OF THUNDER FOR FRIDAY AFTERNOON INTO SATURDAY
EVENING...WITH THE BEST OPPORTUNITY ALONG THE COLD FRONT MOVING
THROUGH ON SATURDAY. THE WARM SOUTHWESTERLY FLOW WILL LEAD TO
SATURDAY BEING THE WARMEST DAY OF THE LONG TERM PERIOD. CURRENTLY
HAVE HIGHS IN THE UPPER 60S...WITH A FEW LOW 70S OVER THE SOUTH
CENTRAL AND IN THE FAVORED DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
MODELS DIFFER ON THE AMOUNT OF COLD AIR SURGING INTO THE AREA ON
SUNDAY NIGHT...WHICH COULD LEAD TO SOME LIGHT LAKE EFFECT RAIN
SHOWERS. AT THIS POINT...THE 12Z ECMWF IS SIGNIFICANTLY COLDER THAN
THE REST OF THE DETERMINISTIC MODELS AND ENSEMBLE MEANS...SO WILL
FOLLOW THE WARMER IDEA AND DIMINISH POPS SUNDAY NIGHT. EXPECT DRY
CONDITIONS ON MONDAY AS HIGH PRESSURE DROPS SOUTHEAST FROM THE
CANADIAN PRAIRIES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 656 PM EDT MON SEP 15 2014
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE FORECAST
PERIOD. WILL GET GUSTY AT IWD AND CMX TUE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT MON SEP 15 2014
HIGH PRESSURE MOVING OVER THE AREA WILL MAINTAIN WINDS GENERALLY
LESS THAN 20 KT TODAY. WSW WINDS MAY INCREASE TO 25 KTS MONDAY NIGHT
INTO TUESDAY AHEAD OF A COLD FRONT. WINDS THEN SHIFT TO NORTHEAST UP
TO 25 KTS IN THE WAKE OF THE COLD FRONT TUESDAY NIGHT. WINDS
DIMINISH TO LESS THAN 20 KTS LATER WED INTO THU AS HIGH PRESSURE
RIDGE CROSSES REGION. NEXT CHANCE OF STRONG WINDS ARRIVES FRIDAY
WITH SOUTH WINDS INCREASING TO 20 TO 30 KTS AHEAD OF DEVELOPING LOW
PRESSURE SYSTEM IN THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 9 AM EDT
/8 AM CDT/ TUESDAY FOR MIZ002-004-005-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 PM EDT MON SEP 15 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EDT MON SEP 15 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM HUDSON BAY TO THE GREAT LAKES. A SHORTWAVE TROUGH FROM CNTRL WI
INTO NE IA SUPPORTED AN AREA OF RAIN FROM SE WI INTO CNTRL LOWER MI.
THE COMINATION OF DAYTIME HEATING AND 700 MB TEMPS NEAR -8C
RESULTING IN STEEP SFC-700 MB LAPSE RATES TO 8C/KM ALONG WITH WEAK
FORCING ON THE NRN END OF THE SHRTWV AND LAKE BREEZE BOUNDARIES
HAVE SUPPORTED ISOLD/SCT LIGHT SHOWERS THAT HAVE SPREAD THROUGH
CNTRL UPPER MI THIS AFTERNOON.
TONIGHT...AS THE SHRTWV DEPARTS TO THE EAST...DAYTIME HEATING
SUBSIDES AND HIGH PRES BUILDS TOWARD THE WRN GREAT LAKES...THE PCPN
WILL END AND CLOUDS WILL THIN OUT. THE CLEARING SKIES AND LIGHT
WINDS OVER THE WESTERN INTERIOR ALONG WITH PWAT VALUES AT OR BELOW
0.5 INCH...OR 50 PCT OF NORMAL...WILL SUPPORT AREAS OF FROST INLAND
AS MIN TEMPS DIP NEAR THE FREEZING MARK ESPECIALLY IN THE WI BORDER
COUNTIES AND OTHER FAVORED COLD SPOTS INTO SW MARQUETTE COUNTY.
TUESDAY...SUNSHINE IN THE MORNING IS EXPECTED TO GIVE WAY TO
INCREASING CLOUDS IN THE AFTERNOON AS A COLD FRONT DAGS SOUTHWARD
THROUGH LAKE SUPERIOR. ANY LIGHT PCPN ASSOCIATED WITH THE FRONT AND
900-800 MB FGEN SHOULD STAY NORTH OF THE KEWEENAW UNTIL EVENING.
OTHERWISE...TEMPERATURES WILL REBOUND CLOSER TO SEASONAL AVERAGES
WITH HIGHS IN THE MID 60S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 304 PM EDT MON SEP 15 2014
NORTHWEST FLOW ALOFT WILL BE IN PLACE FOR MUCH OF THE LONG TERM
FORECAST PERIOD...KEEPING BELOW NORMAL TEMPERATURES IN PLACE
EXCEPT FOR SATURDAY.
AT THE START OF THE PERIOD (TUESDAY NIGHT)...THE HIGH PRESSURE
RIDGE MOVING OVER THE AREA TONIGHT WILL BE SHIFTING TO THE SOUTHEAST
WHILE A COLD FRONT DROPS SOUTHEAST ACROSS LAKE SUPERIOR DURING THE
LATE AFTERNOON AND EVENING HOURS. PRECIPITATION LOOKS TO BE RIGHT
ALONG OR BEHIND THE FRONT ON TUESDAY NIGHT AND THAT CONTINUES INTO
WEDNESDAY AS THE FRONT SLOWLY DROPS ACROSS UPPER MICHIGAN (DUE TO
THE MAIN SHORTWAVE AND LOW QUICKLY PEELING EAST-NORTHEAST). WITH THE
BEST DEEP MOISTURE AND Q-VECTOR CONVERGENCE REMAINING OVER THE
NORTH HALF OF THE CWA (MAINLY OVER LAKE SUPERIOR)...WILL FOCUS THE
HIGHEST POPS IN THAT AREA AND SHOW DECREASING POPS TO THE SOUTH.
THAT SIMILAR IDEA IS EXPECTED FOR QPF...WITH 0.1-0.2 INCH OVER
NORTHERN LAKE SUPERIOR TAPERING TO A TRACE-0.1 INCH OVER THE U.P.
A SECOND UPPER TROUGH (WITH THE MAIN ENERGY IN ONTARIO) WILL SLIDE
SOUTHEAST ACROSS THE U.P. WEDNESDAY AFTERNOON AND USHER IN STRONGER
NORTHWEST FLOW ALOFT AND A HIGH PRESSURE RIDGE INTO THE AREA. THIS
WILL BRING AN END TO ANY PRECIPITATION FROM NORTHWEST TO SOUTHEAST
AS THE DRIER AIR MOVES IN. THE CENTER OF THE HIGH WILL SLIDE
SOUTHEAST ACROSS NORTHERN ONTARIO AND FAR NORTHEAST LAKE SUPERIOR
ON WEDNESDAY NIGHT. THIS WILL LEAD TO THE SKY BECOMING MOSTLY
CLEAR OVER AT LEAST THE NORTHEAST HALF OF UPPER MICHIGAN AND ANOTHER
POTENTIAL FOR FROST ACROSS THE AREA. CLOSER TO THE WISCONSIN
BORDER...MODELS ARE INDICATING SOME CLOUDS LINGERING AS A WEAK
WARM AIR ADVECTION REGIME SETS UP UNDER LIGHT SOUTH-SOUTHWEST FLOW
BETWEEN 925-850MB. THUS...THINK THE BEST OPPORTUNITY FOR FROST WILL
BE OVER THE NORTH CENTRAL AND EAST...CLOSER TO THE HIGH AND
UNDERNEATH THE LOWEST PRECIPITABLE WATER VALUES (AROUND 30 PERCENT
OF NORMAL).
THE HIGH WILL SHIFT EAST ON THURSDAY AND ALLOW THAT BROAD WARM AIR
ADVECTION REGIME TO TAKE SHAPE AND CONTINUE INTO FRIDAY NIGHT.
WITH THE FLOW ALOFT BECOMING A LITTLE MORE ZONAL...THERE ARE
INDICATIONS IN THE MODELS OF WEAK SHORTWAVES SHIFTING EAST ACROSS
THE AREA THURSDAY NIGHT INTO FRIDAY AHEAD OF THE BROAD SURFACE
TROUGH STRETCHING FROM NORTHERN MANITOBA INTO THE CENTRAL PLAINS.
THEREFORE...WILL SHOW INCREASING POPS ON THURSDAY NIGHT AND
CONTINUE THEM INTO FRIDAY AND FRIDAY NIGHT. THE BROAD LOW PRESSURE
TROUGH WILL SHIFT EAST INTO THE UPPER GREAT LAKES REGION ON
SATURDAY AND BRING THE BEST PRECIPITATION CHANCES FOR THE LONG TERM
PERIOD. AT THIS TIME...DON/T EXPECT ANY WIDESPREAD MODERATE/HEAVY
RAIN BUT WILL NEED TO KEEP AN EYE ON THE EVOLUTION OF THE REMNANTS
OF HURRICANE ODILE AS IT LIFTS NORTHEAST THROUGH THE CENTRAL CONUS
AND MERGES WITH THE NORTHERN STREAM FLOW SATURDAY NIGHT. THIS COULD
LEAD TO MORE WIDESPREAD/HEAVIER PRECIPITATION THAN CURRENTLY
ANTICIPATED. UNFORTUNATELY...THE PHASING OF THOSE TWO FEATURES
LEAVES VERY LOW CONFIDENCE FOR THE SECOND HALF OF THE WEEKEND. WILL
CONTINUE THE IDEA OF THUNDER FOR FRIDAY AFTERNOON INTO SATURDAY
EVENING...WITH THE BEST OPPORTUNITY ALONG THE COLD FRONT MOVING
THROUGH ON SATURDAY. THE WARM SOUTHWESTERLY FLOW WILL LEAD TO
SATURDAY BEING THE WARMEST DAY OF THE LONG TERM PERIOD. CURRENTLY
HAVE HIGHS IN THE UPPER 60S...WITH A FEW LOW 70S OVER THE SOUTH
CENTRAL AND IN THE FAVORED DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
MODELS DIFFER ON THE AMOUNT OF COLD AIR SURGING INTO THE AREA ON
SUNDAY NIGHT...WHICH COULD LEAD TO SOME LIGHT LAKE EFFECT RAIN
SHOWERS. AT THIS POINT...THE 12Z ECMWF IS SIGNIFICANTLY COLDER THAN
THE REST OF THE DETERMINISTIC MODELS AND ENSEMBLE MEANS...SO WILL
FOLLOW THE WARMER IDEA AND DIMINISH POPS SUNDAY NIGHT. EXPECT DRY
CONDITIONS ON MONDAY AS HIGH PRESSURE DROPS SOUTHEAST FROM THE
CANADIAN PRAIRIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 402 PM EDT MON SEP 15 2014
EXCEPT FOR A BRIEF PERIOD OF MVFR CIGS AT CMX THROUGH MID AFTERNOON
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE REST OF THE
FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT MON SEP 15 2014
HIGH PRESSURE MOVING OVER THE AREA WILL MAINTAIN WINDS GENERALLY
LESS THAN 20 KT TODAY. WSW WINDS MAY INCREASE TO 25 KTS MONDAY NIGHT
INTO TUESDAY AHEAD OF A COLD FRONT. WINDS THEN SHIFT TO NORTHEAST UP
TO 25 KTS IN THE WAKE OF THE COLD FRONT TUESDAY NIGHT. WINDS
DIMINISH TO LESS THAN 20 KTS LATER WED INTO THU AS HIGH PRESSURE
RIDGE CROSSES REGION. NEXT CHANCE OF STRONG WINDS ARRIVES FRIDAY
WITH SOUTH WINDS INCREASING TO 20 TO 30 KTS AHEAD OF DEVELOPING LOW
PRESSURE SYSTEM IN THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 9 AM EDT
/8 AM CDT/ TUESDAY FOR MIZ002-004-005-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
304 PM EDT MON SEP 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT MON SEP 15 2014
LATEST WV IMAGERY AND RUC ANALYSIS SHOW A BROAD MID/UPPER LEVEL
TROUGH FROM CENTRAL CANADA INTO THE NRN CONUS WITH A SHORTWAVE NOTED
UPSTREAM OVER THE DAKOTAS. DPVA AND MOISTURE AHEAD OF THIS SHORTWAVE
WAS SUPPORTING A MASS OF CLOUDS ALONG WITH SCT SHRA OVER THE SRN
HALF OF MN AND CENTRAL WI. THE NRN EDGE OF THE MID-HIGH CLOUD SHIELD
WAS REACHING INTO THE SCNTRL PORTION OF UPPER MI WHILE THE REST OF
THE FORECAST AREA WAS GENERALLY CLOUD FREE EARLY THIS MORNING.
TODAY...MODELS SHOW SOME WEAK Q-VECT CONV ASSOC WITH UPPER TROUGH
OVERHEAD AND ON NRN EDGE OF FORCING FROM DAKOTAS SHORTWAVE PASSING
SOUTH. SBCAPE OF 50-100 J/KG ALONG WITH SFC-7H LAPSE RATES OF 7.5C
OR HIGHER WHICH COULD SUPPORT SOME SCATTERED LIGHT SHOWERS OR
SPRINKLES AS DAYTIME HEATING INCREASES. BEST CHANCE FOR SHRA WILL BE
CENTRAL AND EAST WHERE AWAY FROM LAKE SUPERIOR WHERE BETTER DAYTIME
HEATING IS EXPECTED. WL MAINTAIN SLIGHT CHC POPS FOR THESE
COUNTIES.
TONIGHT...CLEARING SKIES AND LIGHT WINDS OVER THE WESTERN INTERIOR
ALONG WITH PWAT VALUES AOB 50 PCT OF NORMAL SHOULD SUPPORT AREAS OF
FROST AS MIN TEMPS DIP NEAR THE FREEZING MARK ESPECIALLY ALONG THE
WI BORDER. HAVE INCLUDED GOGEBIC...ONTONAGON...IRON...BARAGA...SRN
HOUGHTON AND DICKINSON COUNTIES IN A FROST ADVISORY FOR LATE TONIGHT
INTO EARLY TUE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 304 PM EDT MON SEP 15 2014
NORTHWEST FLOW ALOFT WILL BE IN PLACE FOR MUCH OF THE LONG TERM
FORECAST PERIOD...KEEPING BELOW NORMAL TEMPERATURES IN PLACE
EXCEPT FOR SATURDAY.
AT THE START OF THE PERIOD (TUESDAY NIGHT)...THE HIGH PRESSURE
RIDGE MOVING OVER THE AREA TONIGHT WILL BE SHIFTING TO THE SOUTHEAST
WHILE A COLD FRONT DROPS SOUTHEAST ACROSS LAKE SUPERIOR DURING THE
LATE AFTERNOON AND EVENING HOURS. PRECIPITATION LOOKS TO BE RIGHT
ALONG OR BEHIND THE FRONT ON TUESDAY NIGHT AND THAT CONTINUES INTO
WEDNESDAY AS THE FRONT SLOWLY DROPS ACROSS UPPER MICHIGAN (DUE TO
THE MAIN SHORTWAVE AND LOW QUICKLY PEELING EAST-NORTHEAST). WITH THE
BEST DEEP MOISTURE AND Q-VECTOR CONVERGENCE REMAINING OVER THE
NORTH HALF OF THE CWA (MAINLY OVER LAKE SUPERIOR)...WILL FOCUS THE
HIGHEST POPS IN THAT AREA AND SHOW DECREASING POPS TO THE SOUTH.
THAT SIMILAR IDEA IS EXPECTED FOR QPF...WITH 0.1-0.2 INCH OVER
NORTHERN LAKE SUPERIOR TAPERING TO A TRACE-0.1 INCH OVER THE U.P.
A SECOND UPPER TROUGH (WITH THE MAIN ENERGY IN ONTARIO) WILL SLIDE
SOUTHEAST ACROSS THE U.P. WEDNESDAY AFTERNOON AND USHER IN STRONGER
NORTHWEST FLOW ALOFT AND A HIGH PRESSURE RIDGE INTO THE AREA. THIS
WILL BRING AN END TO ANY PRECIPITATION FROM NORTHWEST TO SOUTHEAST
AS THE DRIER AIR MOVES IN. THE CENTER OF THE HIGH WILL SLIDE
SOUTHEAST ACROSS NORTHERN ONTARIO AND FAR NORTHEAST LAKE SUPERIOR
ON WEDNESDAY NIGHT. THIS WILL LEAD TO THE SKY BECOMING MOSTLY
CLEAR OVER AT LEAST THE NORTHEAST HALF OF UPPER MICHIGAN AND ANOTHER
POTENTIAL FOR FROST ACROSS THE AREA. CLOSER TO THE WISCONSIN
BORDER...MODELS ARE INDICATING SOME CLOUDS LINGERING AS A WEAK
WARM AIR ADVECTION REGIME SETS UP UNDER LIGHT SOUTH-SOUTHWEST FLOW
BETWEEN 925-850MB. THUS...THINK THE BEST OPPORTUNITY FOR FROST WILL
BE OVER THE NORTH CENTRAL AND EAST...CLOSER TO THE HIGH AND
UNDERNEATH THE LOWEST PRECIPITABLE WATER VALUES (AROUND 30 PERCENT
OF NORMAL).
THE HIGH WILL SHIFT EAST ON THURSDAY AND ALLOW THAT BROAD WARM AIR
ADVECTION REGIME TO TAKE SHAPE AND CONTINUE INTO FRIDAY NIGHT.
WITH THE FLOW ALOFT BECOMING A LITTLE MORE ZONAL...THERE ARE
INDICATIONS IN THE MODELS OF WEAK SHORTWAVES SHIFTING EAST ACROSS
THE AREA THURSDAY NIGHT INTO FRIDAY AHEAD OF THE BROAD SURFACE
TROUGH STRETCHING FROM NORTHERN MANITOBA INTO THE CENTRAL PLAINS.
THEREFORE...WILL SHOW INCREASING POPS ON THURSDAY NIGHT AND
CONTINUE THEM INTO FRIDAY AND FRIDAY NIGHT. THE BROAD LOW PRESSURE
TROUGH WILL SHIFT EAST INTO THE UPPER GREAT LAKES REGION ON
SATURDAY AND BRING THE BEST PRECIPITATION CHANCES FOR THE LONG TERM
PERIOD. AT THIS TIME...DON/T EXPECT ANY WIDESPREAD MODERATE/HEAVY
RAIN BUT WILL NEED TO KEEP AN EYE ON THE EVOLUTION OF THE REMNANTS
OF HURRICANE ODILE AS IT LIFTS NORTHEAST THROUGH THE CENTRAL CONUS
AND MERGES WITH THE NORTHERN STREAM FLOW SATURDAY NIGHT. THIS COULD
LEAD TO MORE WIDESPREAD/HEAVIER PRECIPITATION THAN CURRENTLY
ANTICIPATED. UNFORTUNATELY...THE PHASING OF THOSE TWO FEATURES
LEAVES VERY LOW CONFIDENCE FOR THE SECOND HALF OF THE WEEKEND. WILL
CONTINUE THE IDEA OF THUNDER FOR FRIDAY AFTERNOON INTO SATURDAY
EVENING...WITH THE BEST OPPORTUNITY ALONG THE COLD FRONT MOVING
THROUGH ON SATURDAY. THE WARM SOUTHWESTERLY FLOW WILL LEAD TO
SATURDAY BEING THE WARMEST DAY OF THE LONG TERM PERIOD. CURRENTLY
HAVE HIGHS IN THE UPPER 60S...WITH A FEW LOW 70S OVER THE SOUTH
CENTRAL AND IN THE FAVORED DOWNSLOPE AREAS NEAR LAKE SUPERIOR.
MODELS DIFFER ON THE AMOUNT OF COLD AIR SURGING INTO THE AREA ON
SUNDAY NIGHT...WHICH COULD LEAD TO SOME LIGHT LAKE EFFECT RAIN
SHOWERS. AT THIS POINT...THE 12Z ECMWF IS SIGNIFICANTLY COLDER THAN
THE REST OF THE DETERMINISTIC MODELS AND ENSEMBLE MEANS...SO WILL
FOLLOW THE WARMER IDEA AND DIMINISH POPS SUNDAY NIGHT. EXPECT DRY
CONDITIONS ON MONDAY AS HIGH PRESSURE DROPS SOUTHEAST FROM THE
CANADIAN PRAIRIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 134 PM EDT MON SEP 15 2014
EXCEPT FOR A BRIEF PERIOD OF MVFR CIGS AT CMX THROUGH MID AFTERNOON
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE REST OF THE
FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT MON SEP 15 2014
HIGH PRESSURE MOVING OVER THE AREA WILL MAINTAIN WINDS GENERALLY
LESS THAN 20 KT TODAY. WSW WINDS MAY INCREASE TO 25 KTS MONDAY NIGHT
INTO TUESDAY AHEAD OF A COLD FRONT. WINDS THEN SHIFT TO NORTHEAST UP
TO 25 KTS IN THE WAKE OF THE COLD FRONT TUESDAY NIGHT. WINDS
DIMINISH TO LESS THAN 20 KTS LATER WED INTO THU AS HIGH PRESSURE
RIDGE CROSSES REGION. NEXT CHANCE OF STRONG WINDS ARRIVES FRIDAY
WITH SOUTH WINDS INCREASING TO 20 TO 30 KTS AHEAD OF DEVELOPING LOW
PRESSURE SYSTEM IN THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 9 AM EDT
/8 AM CDT/ TUESDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
159 PM EDT MON SEP 15 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 305 AM EDT MON SEP 15 2014
A COLD FRONT WILL BRING SOME RAIN TODAY. FAIR WEATHER WILL RETURN
TONIGHT AS HIGH PRESSURE MOVES IN. THE NEXT CHANCE FOR RAIN WILL
BE OVER THE WEEKEND AS ANOTHER COLD FRONT MOVES THROUGH.
&&
.UPDATE...
ISSUED AT 1156 AM EDT MON SEP 15 2014
IN THE PROCESS OF SCALING BACK POPS EARLY THIS AFTERNOON BASED ON
CURRENT RADAR TRENDS AND VERY LIGHT RAIN REPORTED UPSTREAM OVER
WISCONSIN. AM FAVORING LATEST HRRR SOLUTIONS THAT DISSIPATE
CURRENT E-W FGEN BAND OF PRECIP OVER OUR CENTRAL ZONES AND
REFOCUS PRECIPITATION TO OUR SOUTHEAST ZONES LATER THIS AFTERNOON.
UPDATES COMING OUT SHORTLY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 305 AM EDT MON SEP 15 2014
NARROW LINE OF SHOWERS ACROSS THE NORTHERN LOWER MICHIGAN ATTM
WILL BE EXPANDING AND MOVING SOUTH TODAY AS UPPER DIVERGENCE
PRECEDES PASSAGE OF 500 MB TROUGH AXIS AND SFC COLD FRONT. RAIN
SHOULD BE ENDING FROM NORTHWEST TO SOUTHEAST LATE THIS AFTERNOON
AND EARLY EVENING WITH STORM TOTAL QPF EXPECTED TO BE AROUND A
QUARTER INCH. HEIGHT RISES FOLLOW TONIGHT AS UPPER TROUGH SHIFTS
EAST WITH SFC RIDGING BUILDING IN SO WE SHOULD SEE CLEARING BY
MIDNIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 AM EDT MON SEP 15 2014
THE LONG TERM PORTION WILL START OUT RATHER QUIET...AND WILL BECOME
A BIT UNSETTLED TOWARD NEXT WEEKEND.
THE ONLY ITEM OF NOTE THROUGH THU NIGHT WILL BE A BACKDOOR COLD
FRONT THAT WILL APPROACH THE AREA FROM THE NE ON WED NIGHT AND INTO
EARLY THU. WE WILL SEE A FAIRLY ROBUST UPPER TROUGH SLIP BY JUST TO
OUR NE AT THAT TIME. THIS WILL TRY TO DRAG A COLD FRONT INTO THE
AREA. WE WILL SEE A SFC RIDGE MOVE NORTH OF THE AREA AND LOW LEVEL
NE FLOW WILL TRY TO ADVECT COOLER AIR IN ACROSS THE STATE.
WE WILL SEE A WARM UP ACROSS THE AREA THEN LATE INTO THIS WEEK AND
AT LEAST THE FIRST HALF OF THE UPCOMING WEEKEND. THE TREND HAS BEEN
FOR LESS ENERGY TO MOVE OUT OF THE WRN STORM AND LIFT NE INTO
CANADA. WE WILL SEE AN UPPER RIDGE ACROSS THE ERN ROCKIES AND PLAINS
EVENTUALLY GET FLATTENED OUT WITH JET ENERGY PLOWING INTO IT. AS
THIS IS HAPPENING...A COLD FRONT WILL BEGIN TO APPROACH THE AREA
WITH A NICE FLOW OF MOISTURE COMING IN FROM THE GULF. THE FRONT
LOOKS TO POTENTIALLY LAY OUT ALONG THE NEARLY ZONAL PATTERN AND
STALL OUT.
WE COULD BE LOOKING AT MULTIPLE ROUNDS OF RAIN IF THIS FRONT STALLS
OUT NEAR THE AREA. IT IS NOT A GIVEN THAT IT WILL STALL OUT...AND IT
COULD BE MORE PROGRESSIVE AND MOVE THROUGH A LITTLE QUICKER. EITHER
WAY...THE BEST CHCS OF RAIN LOOK TO BE CENTERED AROUND SAT WITH
WARMER AIR. TEMPS WILL EVENTUALLY COOL OFF LATE IN THE PERIOD OR
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 159 PM EDT MON SEP 15 2014
RAIN HAS HAD A HARD TIME DEVELOPING OVER THE TAF SITES TODAY AS
WE ARE IN A DRY SLOT IN BETWEEN RAIN AREAS TO THE NORTH AND SOUTH.
CONDITIONS ARE STILL VFR AT 18Z... WITH ANY MVFR LOOKING LIKE IT
WILL HOLD OFF UNTIL AFTER 22Z AND WILL BE PRIMARILY AT THE
AZO/BTL/JXN TAF SITES FOR A FEW HOURS THIS EVENING.
CLEARING/IMPROVEMENT IS STILL EXPECTED LATER THIS EVENING/OVERNIGHT
FROM NORTHWEST TO SOUTHEAST... ALTHOUGH SOME MVFR FOG COULD
DEVELOP IN SPOTS AFTER IT CLEARS. WOULD NOT EVEN RULE OUT THE
POSSIBILITY OF IFR STRATUS/FOG DEVELOPING AFTER 06Z TONIGHT DUE TO
LIGHT WINDS AND MOIST BOUNDARY LAYER...BUT NOT CONFIDENT ENOUGH
YET TO INTRODUCE THOSE LOWER CONDITIONS INTO THE TAFS. IT IS
SOMETHING TO MONITOR FOR FUTURE UPDATES THOUGH.
&&
.MARINE...
ISSUED AT 305 AM EDT MON SEP 15 2014
WILL DROP THE SMALL CRAFT ADVISORY AT 5 AM AS WINDS AND WAVES ARE
DECREASING...WITH 2 TO 4 FOOT WAVES EXPECTED TODAY.
&&
.HYDROLOGY...
ISSUED AT 305 AM EDT MON SEP 15 2014
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...TJT
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...NJJ
AVIATION...MEADE
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
136 PM EDT MON SEP 15 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT MON SEP 15 2014
LATEST WV IMAGERY AND RUC ANALYSIS SHOW A BROAD MID/UPPER LEVEL
TROUGH FROM CENTRAL CANADA INTO THE NRN CONUS WITH A SHORTWAVE NOTED
UPSTREAM OVER THE DAKOTAS. DPVA AND MOISTURE AHEAD OF THIS SHORTWAVE
WAS SUPPORTING A MASS OF CLOUDS ALONG WITH SCT SHRA OVER THE SRN
HALF OF MN AND CENTRAL WI. THE NRN EDGE OF THE MID-HIGH CLOUD SHIELD
WAS REACHING INTO THE SCNTRL PORTION OF UPPER MI WHILE THE REST OF
THE FORECAST AREA WAS GENERALLY CLOUD FREE EARLY THIS MORNING.
TODAY...MODELS SHOW SOME WEAK Q-VECT CONV ASSOC WITH UPPER TROUGH
OVERHEAD AND ON NRN EDGE OF FORCING FROM DAKOTAS SHORTWAVE PASSING
SOUTH. SBCAPE OF 50-100 J/KG ALONG WITH SFC-7H LAPSE RATES OF 7.5C
OR HIGHER WHICH COULD SUPPORT SOME SCATTERED LIGHT SHOWERS OR
SPRINKLES AS DAYTIME HEATING INCREASES. BEST CHANCE FOR SHRA WILL BE
CENTRAL AND EAST WHERE AWAY FROM LAKE SUPERIOR WHERE BETTER DAYTIME
HEATING IS EXPECTED. WL MAINTAIN SLIGHT CHC POPS FOR THESE
COUNTIES.
TONIGHT...CLEARING SKIES AND LIGHT WINDS OVER THE WESTERN INTERIOR
ALONG WITH PWAT VALUES AOB 50 PCT OF NORMAL SHOULD SUPPORT AREAS OF
FROST AS MIN TEMPS DIP NEAR THE FREEZING MARK ESPECIALLY ALONG THE
WI BORDER. HAVE INCLUDED GOGEBIC...ONTONAGON...IRON...BARAGA...SRN
HOUGHTON AND DICKINSON COUNTIES IN A FROST ADVISORY FOR LATE TONIGHT
INTO EARLY TUE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 332 AM EDT MON SEP 15 2014
OVERALL PATTERN IS WELL AGREED ON BY MODELS THROUGH NEXT WEEKEND.
UPPER LEVEL PATTERN TUE AND WED WILL FEATURE A RIDGE OVER THE WRN
CONUS AND A TROUGH OVER THE ERN CONUS. PATTERN BEGINS TO BREAK DOWN
THU...WITH A WEAK TROUGH MOVING ACROSS THE NCENTRAL CONUS LATE FRI
AND SAT.
SFC HIGH PRESSURE WILL MAKE FOR A DRY AND SUNNY TUE WITH HIGH TEMPS
EVEN AROUND NORMAL IN THE MID TO UPPER 60S.
A SHORTWAVE TROUGH WILL MOVE ACROSS FAR NRN QUEBEC ON TUE...DROPPING
THE ASSOCIATED COLD FRONT DOWN FROM THE NNE TUE NIGHT INTO WED AS
ANOTHER WEAKER SHORTWAVE DROPS DOWN ALONG THE FRONT. MOST MODELS
SHOWING QPF ALONG THE FRONT AND AHEAD OF THE SHORTWAVE...BUT EXACT
TIMING AND PLACEMENT IS STILL SOMEWHAT DISAGREED ON. WILL INCREASE
POPS GIVEN THE INCREASED CONFIDENCE IN PRECIP OCCURRING. WED LOOKS
QUITE A BIT COOLER THAN TUE...MAINLY OVER THE NRN HALF OF THE CWA
WHERE THE FRONT WILL PASS THROUGH EARLIER. EXPECT HIGHS RANGING FROM
AROUND 50 ALONG LAKE SUPERIOR TO 60 OVER THE SCENTRAL. ECMWF AND GEM
SHOW LIGHT QPF OVER THE CWA LATE WED INTO WED NIGHT...BUT WITH A
1025MB SFC HIGH CENTER OVER OR NEAR THE CWA DURING THIS TIME...WILL
LEAN TOWARD THE DRIER GFS AND NAM SOLUTIONS. MAY SEE FROST OVER
INTERIOR ERN UPPER MI WED NIGHT...BUT THE TEMPS WILL BE DEPENDENT ON
CLOUD COVER AND PRECIP CHANCES. WILL KEEP A COLD FORECAST WITH FROST
GIVEN PREFERENCE FOR DRIER SOLUTIONS.
THU LOOKS MOSTLY DRY...BUT RAIN CHANCES WILL INCREASE THU NIGHT
THROUGH SAT. INITIALLY...PRIMARY DRIVER FOR THE PRECIP WILL BE
WAA/ISENTROPIC LIFT RESULTING FROM BEEFY SSWLY LOW LEVEL FLOW
BETWEEN THE IMPENDING SFC TROUGH AND DEPARTING SFC HIGH. FORCING
THEM TRANSITIONS TO LARGE SCALE FORCING ALONG THE UPPER/SFC TROUGHS
ON SAT...BUT WILL RECEIVE AT LEAST SOME ADDITIONAL FORCING FROM
INSTABILITY. MODELS SHOW UP TO 700J/KG OF CAPE ON SAT...BUT THAT
WILL BE HIGHLY DEPENDENT ON CLOUD COVER AND OTHER FACTORS. THERE IS
POTENTIAL FOR DECENT CAPE GIVEN POSSIBILITY OF HOT SFC TEMPS AS
850MB TEMPS INCREASE TO 16C AHEAD OF THE COLD FRONT LAKE FRI NIGHT
INTO SAT. WILL NEED CONTINUE TO ASSESS THE SEVERE THREAT AS THE EVEN
APPROACHES.
COOLER AND DRIER WEATHER LOOKS TO BE IN STORE FOR SUN AS A SFC HIGH
MOVES INTO THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 134 PM EDT MON SEP 15 2014
EXCEPT FOR A BRIEF PERIOD OF MVFR CIGS AT CMX THROUGH MID AFTERNOON
VFR CONDITIONS WILL PREVAIL AT THE TAF SITES THROUGH THE REST OF THE
FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT MON SEP 15 2014
HIGH PRESSURE MOVING OVER THE AREA WILL MAINTAIN WINDS GENERALLY
LESS THAN 20 KT TODAY. WSW WINDS MAY INCREASE TO 25 KTS MONDAY NIGHT
INTO TUESDAY AHEAD OF A COLD FRONT. WINDS THEN SHIFT TO NORTHEAST UP
TO 25 KTS IN THE WAKE OF THE COLD FRONT TUESDAY NIGHT. WINDS
DIMINISH TO LESS THAN 20 KTS LATER WED INTO THU AS HIGH PRESSURE
RIDGE CROSSES REGION. NEXT CHANCE OF STRONG WINDS ARRIVES FRIDAY
WITH SOUTH WINDS INCREASING TO 20 TO 30 KTS AHEAD OF DEVELOPING LOW
PRESSURE SYSTEM IN THE PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM MIDNIGHT EDT /11 PM CDT/ TONIGHT TO 9 AM EDT
/8 AM CDT/ TUESDAY FOR MIZ002-004-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
244 PM CDT MON SEP 15 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 244 PM CDT MON SEP 15 2014
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER WESTERN NORTH AMERICA WHILE TROUGHING DOMINATED
EASTERN CANADA INTO THE GREAT LAKES REGION. THE MAIN SHORTWAVE OF
NOTE WITHIN THIS TROUGH WAS OVER SOUTHERN WI...WHICH WAS RESPONSIBLE
FOR BRINGING THE RAIN TO THE FORECAST AREA THIS MORNING AND EARLY
THIS AFTERNOON. THAT RAIN HAS NOW PUSHED OFF TO THE EAST...ALLOWING
SUBSIDENCE AND DRYING TO SPREAD INTO THE FORECAST AREA. GOES DERIVED
PRECIPITABLE WATER VALUES ARE 0.3-0.5 INCHES ACROSS THE DAKOTAS AND
MN. CLEARING SKIES ACROSS THE DAKOTAS ALONG WITH PEAKS OF SUN INTO
THE FORECAST AREA AS SEEN ON VISIBLE SATELLITE IMAGERY REFLECTS THIS
SUBSIDENCE AND CLEARING. HIGH PRESSURE AT THE SURFACE OVER EASTERN
SOUTH DAKOTA ALSO REFLECTS THE SUBSIDENCE. COOLER AIR HAS ALSO
SPREAD INTO THE REGION...WITH 925MB TEMPS ABOUT 4C COOLER OVER THE
PAST 24 HOURS TO AROUND 8C PER LATEST RAP ANALYSIS. AS SUCH...
TEMPERATURES ARE OFF 10 TO 15 DEGREES COMPARED TO THIS TIME
YESTERDAY.
NO PRECIPITATION IS EXPECTED IN THE SHORT TERM PERIOD...RESULTING
FROM PLENTY OF DRY ADVECTION AND SUBSIDENCE IN THE WAKE OF TODAYS
SHORTWAVE TROUGH. PRECIPITABLE WATER VALUES FALL INTO THE 0.3-0.5
INCH RANGE AS SEEN UPSTREAM THIS EVENING...THEN STAY THERE THROUGH
TUESDAY. THIS DRY AIR AND ASSOCIATED CLEARING WITH LOSS OF DAYTIME
HEATING MEANS POTENTIAL FOR DECENT RADIATIONAL COOLING TONIGHT.
ADDITIONALLY...IT APPEARS WE SHOULD HAVE A SURFACE RIDGE EXTENDING
FROM THE CENTER OF THE HIGH OVER SOUTH DAKOTA CROSSING THE FORECAST
AREA TONIGHT. ITS NOT NEARLY AS IDEAL AS HAVING THE HIGH COMING
OVERHEAD...WHICH INSTEAD LOOKS TO TRACK THROUGH WESTERN IA...BUT
CONDITIONS ARE STILL FAVORABLE. THIS SITUATION SUGGESTS FOLLOWING A
BLEND OF MOS GUIDANCE AND 30 DAY BIAS CORRECTED 2 METER OUTPUT FROM
THE RAW MODELS FOR LOWS. THE RESULT ENDS UP WITH MUCH OF THE
FORECAST AREA BETWEEN THE MID 30S AND LOWER 40S...THOUGH SOME OF THE
TYPICAL COLD SPOTS SUCH AS WESTERN TAYLOR COUNTY TO SPARTA...BLACK
RIVER FALLS AND VOLK FIELD WILL FALL INTO THE LOWER 30S. THOSE
TYPICAL COLD SPOTS WOULD BE UNDER THE MOST CONCERN FOR FROST...AND
HAVE COVERED THEM WITH A FROST ADVISORY. MEANWHILE...VALLEYS COULD
SEE SOME FOG AND STRATUS...ESPECIALLY THE SMALLER TRIBUTARIES WHICH
CAN DECOUPLE MORE THAN THE MAIN MISSISSIPPI CHANNEL.
PLENTY OF SUN TUESDAY MORNING SHOULD ALLOW ANY VALLEY FOG/STRATUS TO
MIX OUT QUICKLY. SOME DIURNAL CUMULUS MAY POP UP...BUT NOT ENOUGH TO
RESTRICT HEATING. WITH 925MB TEMPS PROGGED AROUND 10C ON TUESDAY AND
PLENTY OF DRY AIR...HIGHS SHOULD EASILY TOP OUT IN THE 60S WHILE
DEWPOINTS MIX DOWN INTO THE UPPER 30S/LOW 40S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 244 PM CDT MON SEP 15 2014
MODELS REMAIN IN GOOD AGREEMENT THAT MUCH OF THE LONG TERM PERIOD
THROUGH THURSDAY WILL BE DOMINATED BY HIGH PRESSURE. THERE IS A
BACKDOOR COLD FRONT THAT IS ON TAP TO DROP SOUTH THROUGH THE
FORECAST AREA WEDNESDAY AFTERNOON AND EVENING...BUT AT THIS TIME
THERE DOES NOT APPEAR TO BE ENOUGH MOISTURE FOR THE FRONT TO PRODUCE
PRECIPITATION. PRECIPITABLE WATER VALUES DO CLIMB SLIGHTLY TUESDAY
NIGHT SO IT SHOULD NOT BE AS COOL AS TONIGHT. HOWEVER...NAM/GFS
SOUNDINGS SUGGEST A LIGHTER WIND FIELD THROUGH A DEEPER DEPTH IN THE
MISSISSIPPI RIVER VALLEY...WHICH SHOULD TRANSLATE INTO A GREATER
POTENTIAL FOR VALLEY FOG/STRATUS DESPITE THE DRIER CONDITIONS FROM
TUESDAY. MORE VALLEY FOG COULD OCCUR WEDNESDAY NIGHT...BUT MAY HAVE
TO WATCH FOR POTENTIAL LINGERING CLOUDS ON AND BEHIND THE
AFOREMENTIONED BACKDOOR COLD FRONT. HIGH TEMPERATURES SHOULD GET
BACK UP CLOSE TO SEASONAL NORMS ON WEDNESDAY AS WARMER AIR COMES IN
AHEAD OF THE FRONT. MUCH OF THE COOL AIR BEHIND THE FRONT LOOKS TO
DEFLECT OFF TO THE EAST FOR THURSDAY...ALLOWING HIGH TEMPERATURES TO
END UP SIMILAR TO WEDNESDAY.
FOR THURSDAY NIGHT INTO EARLY NEXT WEEK...THERE HAS BEEN SOME
CHANGES TO THE EXTENDED FORECAST. FIRST...MODELS ARE SLOWER BRINGING
THE 850MB MOISTURE TRANSPORT AND ASSOCIATED INSTABILITY TOWARDS THE
REGION THURSDAY NIGHT...AS WELL AS SHIFTING ITS FOCUS FARTHER NORTH
INTO CENTRAL AND NORTHERN MN. AS A RESULT...ALL PRECIPITATION LOOKS
TO OCCUR WEST OF THE FORECAST AREA AND HAVE THEREFORE DRIED OUT THE
FORECAST. THAT 850MB MOISTURE TRANSPORT STREAM AND HIGHER
PRECIPITABLE WATER UPWARDS OF 1.5 INCHES STILL LOOKS TO MOVE INTO
THE FORECAST AREA FOR FRIDAY...HOWEVER...LIKE THURSDAY NIGHT THE
CONVECTIVE FOCUS APPEARS TO BE SHIFTING NORTH WITH MORE UPPER
RIDGING PROGGED OVER THE AREA. HAVE LOWERED CHANCES SOUTH OF I-90 AS
A RESULT. AN UPPER TROUGH STILL LOOKS ON TRACK TO DIG SOUTHEAST INTO
THE FORECAST AREA FRIDAY NIGHT AND SATURDAY. THIS TROUGH PICKS UP
THE REMNANTS OF CURRENT HURRICANE ODILE ON THE BAJA PENINSULA...
RESULTING IN PLENTIFUL MOISTURE FOR THE UPPER TROUGH TO PRODUCE
CONVECTION AS IT SLIDES THROUGH. FOLLOWED A CONSENSUS FORECAST WHICH
BRINGS CHANCES UP TOWARDS 60. IF CURRENT TRENDS CONTINUE THESE
CHANCES WILL NEED TO GO UP MORE. MAY STILL HAVE TO CONTEND WITH A
SEVERE THREAT...WITH THE TIMING NOW LOOKING MORE LIKE OVERNIGHT
FRIDAY NIGHT INTO SATURDAY MORNING. GENERALLY QUIET CONDITIONS WITH
TEMPERATURES A LITTLE BELOW NORMAL ARE EXPECTED FOR SUNDAY AND
MONDAY AS NORTHWEST FLOW SETS UP AGAIN OVER THE REGION.
HOWEVER...15.12Z ECMWF IS VERY AMPLIFIED IN BRINGING A POTENT UPPER
LOW THROUGH THE REGION ON MONDAY. SHOULD THIS OCCUR...RAIN CHANCES
WILL NEED TO BE INTRODUCED ALONG WITH AT LEAST A 10 DEGREE DROP IN
TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1217 PM CDT MON SEP 15 2014
RAIN AREA HAS SHIFTED EAST OF BOTH AIRFIELDS. MAIN CLOUD SHIELD
HAS ALSO PUSHED EAST...BUT CUMULUS QUICKLY DEVELOPED BEHIND WITH
PLENTY OF RESIDUAL BOUNDARY LAYER MOISTURE. THIS EXPECTED TO BE
DIURNAL SO CLEAR SKIES SHOULD PREVAIL BY SUNSET. SOME CONCERN WITH
LIGHT WINDS AND CLEAR SKIES THAT THE VALLEY NEAR KLSE COULD SEE
SOME FOG OR STRATUS. WITH DRIER AIR TRYING TO WORK IN AND HIGHER
WINDS SEEN JUST OFF THE SURFACE IN MODEL SOUNDINGS...DO NOT FEEL
WIDESPREAD DENSE FOG IS LIKELY. MAINTAINED PREVIOUS FORECAST OF
BCFG TO COVER THE POSSIBILITY THAT DECOUPLING WILL ALLOW FOR SOME
GROUND FOG.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM CDT TUESDAY FOR
WIZ017-029-034-042>044.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1111 AM CDT MON SEP 15 2014
.UPDATE...
500 MB SHORTWAVE TROUGH WILL SLIDE EAST SOUTHEAST THROUGH THE
AREA THIS AFTERNOON. LIGHT RAIN SHOWERS ASSOCIATED WITH THIS
FEATURE WILL CONTINUE TO SHIFT EAST INTO AND THROUGH THE AREA.
SHOWERS WILL END FROM WEST TO EAST FROM MIDDLE TO LATE
AFTERNOON...ASSOCIATED WITH DOWNWARD VERTICAL MOTION ON BACKSIDE
OF SHORTWAVE TROUGH. CLOUDS MAY MIX OUT IN THE WEST LATER THIS
AFTERNOON AS WELL. TEMPERATURES WILL LINGER IN THE MIDDLE TO UPPER
50S ACROSS MOST OF THE AREA...WITH THE CLOUDS AND SHOWERS.
&&
.AVIATION/18Z TAFS/...
AREA OF SHOWERS WITH VFR/MVFR CEILINGS WILL SHIFT EAST SOUTHEAST
THROUGH TAF SITES THIS AFTERNOON...WITH A TROUGH OF LOW PRESSURE.
SHOWERS SHOULD END AT MADISON BY 21Z...WITH THE EASTERN SITES BY
00Z TUESDAY. LIGHT AND VARIABLE WINDS WILL BECOME NORTH BY MID
AFTERNOON...AS COLD FRONT SLIDES SOUTH OF THE AREA.
HIGH PRESSURE MOVING TO THE SOUTH OF THE AREA TONIGHT AND TUESDAY
WILL BRING QUIET WEATHER TO THE AREA. WINDS WILL WEAKEN
TONIGHT...AND BECOME LIGHT AND WESTERLY ON TUESDAY. LIGHT FOG IS
POSSIBLE IN LOW LYING AREAS LATER TONIGHT INTO EARLY TUESDAY
MORNING...BUT LEFT OUT OF TAFS DUE TO LOW CONFIDENCE.
&&
.PREV DISCUSSION... /ISSUED 337 AM CDT MON SEP 15 2014/
SHORT TERM...
TODAY...FORECAST CONFIDENCE MEDIUM.
A STRONG...DIGGING MID LEVEL SHORTWAVE WILL BARREL ACROSS THE UPPER
MIDWEST TODAY. IT IS CURRENTLY OVER THE DAKOTAS AND WILL EXIT
SOUTHEAST WI AROUND 00Z THIS EVENING. IN RESPONSE...STRONG 925-850MB
FRONTOGENESIS WILL SLIDE EAST THROUGH CENTRAL AND SOUTHERN WI THIS
MORNING.
MID LEVEL FRONTOGENESIS IS RESPONSIBLE FOR THE WEAK RETURNS AND
LIGHT RAIN OVER CENTRAL WI EARLY THIS MORNING. SATURATION IN THE LOW
LEVELS HAS BEEN VERY SLOW OVERNIGHT...THUS NOT MUCH RAIN IS REACHING
THE GROUND. SHOWERS ARE CURRENTLY EXPANDING ACROSS SOUTHERN MN WITH
THE FGEN. THE HRRR AND HI-RES WRF MODELS HAVE A GOOD HANDLE ON THE
PRECIP EARLY THIS MORNING...SO I FOLLOWED THAT GUIDANCE CLOSELY FOR
TIMING. RAIN SHOULD ARRIVE IN MADISON AROUND 8 AM AND MILWAUKEE BY
10 AM.
GIVEN THE COMPACT NATURE OF THE SHORT WAVE AND THE SHARP SUBSIDENCE
EXPECTED IN ITS WAKE...THE RAIN WILL SHUT OFF VERY QUICKLY FROM WEST
TO EAST ON MONDAY...ENDING WEST OF MADISON BY LATE MORNING...AND IN
THE MILWAUKEE AREA BY ABOUT MID AFTERNOON. RAPID CLEARING SHOULD
THEN FOLLOW.
CLOUDS AND PRECIP WILL LEAD TO COOLER TEMPS TODAY...WITH HIGHS IN
THE MID TO UPPER 50S.
TONIGHT...FORECAST CONFIDENCE HIGH.
SURFACE HIGH PRESSURE WILL QUICKLY SETTLE INTO THE MIDWEST
OVERNIGHT. LIGHT WINDS...CLEAR SKIES AND RECENT RAIN OVER SOUTHERN
WI WILL ALLOW FOR QUICK COOLING AND SOME PATCHY LIGHT FOG. LOWS ARE
EXPECTED IN THE UPPER 30S INLAND...WARMER NEAR THE LAKESHORE.
LONG TERM...
TUESDAY THROUGH THURSDAY...FORECAST CONFIDENCE HIGH.
SURFACE HIGH PRESSURE OVER THE AREA TUESDAY AND WEDNESDAY WILL
KEEP SKIES MOSTLY CLEAR WITH LIGHT WINDS AND GOOD RADIATIONAL
COOLING WHICH SHOULD PERMIT FOG FORMATION IN FAVORABLE VALLEY AREAS
DURING EARLY MORNING HOURS. APPROACHING CANADIAN HIGH PRESSURE
SYSTEM WEDNESDAY NIGHT SHOULD PUSH A BACKDOOR COLD FRONT ACROSS
SOUTHEAST WISCONSIN AND LAKE MICHIGAN WED NIGHT AND CREATE WINDS
OVER THE WATERS THAT MAY REACH SMALL CRAFT ADVISORY CRITERIA. THE
COLD FRONT WILL BE SHALLOW WITH LITTLE LIFT OR MOISTURE TO WORK
WITH...THUS THE FORECAST REMAINS DRY.
THURSDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM.
THURSDAY NIGHT AND FRIDAY THE CANADIAN HIGH PRESSURE SYSTEM MOVES
WELL NORTHEAST OF THE GREAT LAKES...CREATING A SOUTHERLY FLOW ACROSS
WISCONSIN WHICH WILL BRING WARMER TEMPERATURES AND ADDITIONAL
MOISTURE TO THE AREA FOR THE WEEKEND. WEAK UPPER LEVEL DISTURBANCES
IN ZONAL FLOW ALOFT WILL COMBINE WITH SIGNIFICANT LOW LEVEL MOISTURE
TO BRING A CHANCE OF SHOWERS TO THE REGION FRIDAY AND FRIDAY NIGHT.
A DEEPER LOW WILL MOVE ACROSS LAKE SUPERIOR SATURDAY NIGHT AND BRING
AN ASSOCIATED COLD FRONT AND CHANCE OF RAIN TO WISCONSIN
SATURDAY...WITH CLEARING SATURDAY NIGHT AS THE FRONT PASSES.
AVIATION/12Z TAFS/...
A FAST MOVING AND POTENT MID LEVEL SHORT WAVE WILL TRACK THROUGH THE
UPPER MIDWEST THIS MORNING. LOOK FOR A PERIOD OF RAINFALL THAT WILL
LAST ABOUT 5-6 HOURS OVER SOUTHERN WI...THEN CLEAR OUT QUICKLY. CIGS
ARE EXPECTED TO DROP TO MVFR LEVELS WITHIN A FEW HOURS OF THE RAIN
STARTING...THEN CLEAR OUT WITHIN A FEW HOURS AFTER THE RAIN ENDS.
THE RAIN SHOULD BEGIN AT KMSN AROUND 12-13Z TODAY AND REACH
KMKE/KUES/KENW ABOUT 14-15Z. LOOK FOR IT TO END AT KMSN BY 19Z...
22Z AT KMKE/KUES/KENW. THE MVFR CIGS AND POSSIBLE MVFR VSBYS WILL
OCCUR DURING THE CORE OF THE RAINFALL.
CLEAR SKIES...RECENT RAIN AND LIGHT WINDS WITH HIGH PRESSURE
OVERNIGHT COULD LEAD TO SOME PATCHY MVFR FOG INLAND LATE TONIGHT
INTO MONDAY MORNING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...MRC
TUESDAY THROUGH SUNDAY...SLB